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A riverbank is made of what?
0. animals
1. oceans
2. loam
3. bones
increased which provides more useful information about the behaviour of rivers and their ecosystems. engineering experts are able to analyse and adapt in a more environmentally conscious way. renaturalisation projects raise more awareness for the environment, however, rapidly growing and urbanizing population needs to be supplied with enough water resources and hydropower energy, which calls for more sustainable solutions. = = = river pollution = = = water pollution occurs when water bodies, such as rivers, lakes and oceans are contaminated with harmful substances. these substances degrade the water quality and are toxic to humans as consumers and to the environment. the contamination in a river can come from a point source or non - point source pollution. the most common types of surface water pollution are agriculture, sewage and waste water ( including stormwater runoff ), oil pollution and radioactive substances. the agricultural sector consumes a lot of fresh water and is the leading source for water degradation. = = = timeline = = = most settlements in human history were placed along rivers, developing into riverine cities and traceable by their considerable environmental footprint. the human influence on rivers can be divided into six chronological stages : = = consequences = = while river engineering can improve the behaviour of the river or hold it back to adapt to our infrastructure, and therefore be rated as positive or negative impact, pollution undoubtedly has a negative impact on our environment. the consequences are very complex and difficult to measure and classify, as often benefits for humankind imply drawbacks for the environment and the other way around. = = = indicators = = = indicators that make the human impact measurable and quantitatively assessable are : artificial water surface ratio, artificial water surface density ratio, disruption of longitudinal connectivity ratio, artificial river ratio, sinuosity of artificial cutoff, channelization ratio, artificial levee ratio, road along river ratio, artificial sediment transport ratio and the integrated river structure impact index. = = = material and sediment flux = = = through anthropogenic impact the material flux of rivers has changed, which enters the sea and has a strong effect on coastal and shelf environments. = = = runoff = = = alternate land use, deforestation, afforestation and different types of river engineering have also led to changes in hydrologic processes, such as runoff. mushrooming illegal mining activity can, for example, change the soil structure, the pressure - gradient between stream flow and groundwater and the vegetation cover and therefore lead to increased or decreased runoff. in southern ghana in the lower pra river basin, the percentage of runoff change, which is
. the piave, also in italy, is an example of a river that is transitioning from braided to meandering due to human interventions. the waimakariri river of new zealand is an example of a braided river with an extensive floodplain. = = see also = = anabranch β a section of a river or stream that diverts from the main channel and rejoins it downstream lagoon β shallow body of water separated from a larger one by a narrow landform shoal β natural submerged sandbank that rises from a body of water to near the surface = = references = = = = further reading = = hibbert, barry ; brown, kerry, eds. ( 2001 ). braided river field guide. christchurch, n. z. : department of conservation. isbn 9780478221213. = = external links = = media related to braided rivers at wikimedia commons
many river systems are shaped by human activity and through anthropogenic forces. the process of human influence on nature, including rivers, is stated with the beginning of the anthropocene, which has replaced the holocene. this long - term impact is analyzed and explained by a wide range of sciences and stands in an interdisciplinary context. the natural water cycle and stream flow is globally influenced and linked to global interconnections. rivers are an essential component of the terrestrial realm and have been a preferable location for human settlements during history. river is the main expression used for river channels themselves, riparian zones, floodplains and terraces, adjoining uplands dissected by lower channels and river deltas. = = human impact = = the relationship between humans and rivers, which represent freshwater environments, is complicated. rivers serve primarily as a freshwater resource and as sinks for domestic and industrial waste water. the consequences from this usage occur from diverse activities and root themselves in complex, interdisciplinary systems and practices. environmental changes in rivers usually result from human development, such as population growth, the dependence on fossil resources, urbanization, global commerce and industrial and agricultural emission. anthropogenic activities also include discrete elements like the use of fire, domestication of plants and animals, soil development, the establishment of settlements and irrigation. river ecosystems have been transformed downstream from the point of pollution. active human transformations, river engineering, have altered the river systems and ecosystems. = = = river engineering = = = river engineering, a branch of civil engineering, deals with the process of planned human intervention to improve and restore rivers for human and environmental needs. with modern technologies, data collection and modelling, navigation can be improved, dredging reduced and new habitats can be created. river engineering also handles sediment and erosion control, which can be a threat to humankind by destroying infrastructure, hindering water supply and causing major river cutoffs. river training structures will help to modify the hydraulic flow and the sediment response of a river. humans have modified the natural behavior of rivers for longer than history is recorded. the management of water resources, protection against floods and hydropower are not new concepts. regardless, river engineering has changed in the past century because of environmental concerns. the available amount and type of data about rivers has increased which provides more useful information about the behaviour of rivers and their ecosystems. engineering experts are able to analyse and adapt in a more environmentally conscious way. renaturalisation projects raise more awareness for the environment, however, rapidly growing and urbanizing
change has resulted in less water available for rivers during the summer. regulation of pollution, dam removal, and sewage treatment have helped to improve water quality and restore river habitats. certain organisms such as sponges and fungi are useful bioindicators for river health. = = topography = = = = = definition = = = a river is a natural flow of freshwater that flows on or through land towards another body of water downhill. this flow can be into a lake, an ocean, or another river. a stream refers to water that flows in a natural channel, a geographic feature that can contain flowing water. a stream may also be referred to as a watercourse. the study of the movement of water as it occurs on earth is called hydrology, and their effect on the landscape is covered by geomorphology. = = = source and drainage basin = = = rivers are part of the water cycle, the continuous processes by which water moves about earth. this means that all water that flows in rivers must ultimately come from precipitation. the sides of rivers have land that is at a higher elevation than the river itself, and in these areas, water flows downhill into the river. the headwaters of a river are the smaller streams that feed a river, and make up the river's source. these streams may be small and flow rapidly down the sides of mountains. all of the land uphill of a river that feeds it with water in this way is in that river's drainage basin or watershed. a ridge of higher elevation land is what typically separates drainage basins ; water on one side of a ridge will flow into one set of rivers, and water on the other side will flow into another. one example of this is the continental divide of the americas in the rocky mountains. water on the western side of the divide flows into the pacific ocean, whereas water on the other side flows into the atlantic ocean. not all precipitation flows directly into rivers ; some water seeps into underground aquifers. these, in turn, can still feed rivers via the water table, the groundwater beneath the surface of the land stored in the soil. water flows into rivers in places where the river's elevation is lower than that of the water table. this phenomenon is why rivers can still flow even during times of drought. rivers are also fed by the melting of snow glaciers present in higher elevation regions. in summer months, higher temperatures melt snow and ice, causing additional water to flow into rivers. glacier melt can supplement snow melt in times like the late summer,
##logists to understand the health of its ecosystems, the rate of erosion of the river's environment, and the effects of human activity. rivers rarely run in a straight direction, instead preferring to bend or meander. this is because any natural impediment to the flow of the river may cause the current to deflect in a different direction. when this happens, the alluvium carried by the river can build up against this impediment, redirecting the course of the river. the flow is then directed against the opposite bank of the river, which will erode into a more concave shape to accommodate the flow. the bank will still block the flow, causing it to reflect in the other direction. thus, a bend in the river is created. rivers may run through low, flat regions on their way to the sea. these places may have floodplains that are periodically flooded when there is a high level of water running through the river. these events may be referred to as " wet seasons'and " dry seasons " when the flooding is predictable due to the climate. the alluvium carried by rivers, laden with minerals, is deposited into the floodplain when the banks spill over, providing new nutrients to the soil, allowing them to support human activity like farming as well as a host of plant and animal life. deposited sediment from rivers can form temporary or long - lasting fluvial islands. these islands exist in almost every river. = = = = non - perennial rivers = = = = about half of all waterways on earth are intermittent rivers, which do not always have a continuous flow of water throughout the year. this may be because an arid climate is too dry depending on the season to support a stream, or because a river is seasonally frozen in the winter ( such as in an area with substantial permafrost ), or in the headwaters of rivers in mountains, where snowmelt is required to fuel the river. these rivers can appear in a variety of climates, and still provide a habitat for aquatic life and perform other ecological functions. = = = = subterranean rivers = = = = subterranean rivers may flow underground through flooded caves. this can happen in karst systems, where rock dissolves to form caves. these rivers provide a habitat for diverse microorganisms and have become an important target of study by microbiologists. other rivers and streams have been covered over or converted to run in tunnels due to human development. these rivers do not typically host any life, and are
Answer:
|
loam
| null |
A riverbank is made of what?
0. animals
1. oceans
2. loam
3. bones
increased which provides more useful information about the behaviour of rivers and their ecosystems. engineering experts are able to analyse and adapt in a more environmentally conscious way. renaturalisation projects raise more awareness for the environment, however, rapidly growing and urbanizing population needs to be supplied with enough water resources and hydropower energy, which calls for more sustainable solutions. = = = river pollution = = = water pollution occurs when water bodies, such as rivers, lakes and oceans are contaminated with harmful substances. these substances degrade the water quality and are toxic to humans as consumers and to the environment. the contamination in a river can come from a point source or non - point source pollution. the most common types of surface water pollution are agriculture, sewage and waste water ( including stormwater runoff ), oil pollution and radioactive substances. the agricultural sector consumes a lot of fresh water and is the leading source for water degradation. = = = timeline = = = most settlements in human history were placed along rivers, developing into riverine cities and traceable by their considerable environmental footprint. the human influence on rivers can be divided into six chronological stages : = = consequences = = while river engineering can improve the behaviour of the river or hold it back to adapt to our infrastructure, and therefore be rated as positive or negative impact, pollution undoubtedly has a negative impact on our environment. the consequences are very complex and difficult to measure and classify, as often benefits for humankind imply drawbacks for the environment and the other way around. = = = indicators = = = indicators that make the human impact measurable and quantitatively assessable are : artificial water surface ratio, artificial water surface density ratio, disruption of longitudinal connectivity ratio, artificial river ratio, sinuosity of artificial cutoff, channelization ratio, artificial levee ratio, road along river ratio, artificial sediment transport ratio and the integrated river structure impact index. = = = material and sediment flux = = = through anthropogenic impact the material flux of rivers has changed, which enters the sea and has a strong effect on coastal and shelf environments. = = = runoff = = = alternate land use, deforestation, afforestation and different types of river engineering have also led to changes in hydrologic processes, such as runoff. mushrooming illegal mining activity can, for example, change the soil structure, the pressure - gradient between stream flow and groundwater and the vegetation cover and therefore lead to increased or decreased runoff. in southern ghana in the lower pra river basin, the percentage of runoff change, which is
. the piave, also in italy, is an example of a river that is transitioning from braided to meandering due to human interventions. the waimakariri river of new zealand is an example of a braided river with an extensive floodplain. = = see also = = anabranch β a section of a river or stream that diverts from the main channel and rejoins it downstream lagoon β shallow body of water separated from a larger one by a narrow landform shoal β natural submerged sandbank that rises from a body of water to near the surface = = references = = = = further reading = = hibbert, barry ; brown, kerry, eds. ( 2001 ). braided river field guide. christchurch, n. z. : department of conservation. isbn 9780478221213. = = external links = = media related to braided rivers at wikimedia commons
many river systems are shaped by human activity and through anthropogenic forces. the process of human influence on nature, including rivers, is stated with the beginning of the anthropocene, which has replaced the holocene. this long - term impact is analyzed and explained by a wide range of sciences and stands in an interdisciplinary context. the natural water cycle and stream flow is globally influenced and linked to global interconnections. rivers are an essential component of the terrestrial realm and have been a preferable location for human settlements during history. river is the main expression used for river channels themselves, riparian zones, floodplains and terraces, adjoining uplands dissected by lower channels and river deltas. = = human impact = = the relationship between humans and rivers, which represent freshwater environments, is complicated. rivers serve primarily as a freshwater resource and as sinks for domestic and industrial waste water. the consequences from this usage occur from diverse activities and root themselves in complex, interdisciplinary systems and practices. environmental changes in rivers usually result from human development, such as population growth, the dependence on fossil resources, urbanization, global commerce and industrial and agricultural emission. anthropogenic activities also include discrete elements like the use of fire, domestication of plants and animals, soil development, the establishment of settlements and irrigation. river ecosystems have been transformed downstream from the point of pollution. active human transformations, river engineering, have altered the river systems and ecosystems. = = = river engineering = = = river engineering, a branch of civil engineering, deals with the process of planned human intervention to improve and restore rivers for human and environmental needs. with modern technologies, data collection and modelling, navigation can be improved, dredging reduced and new habitats can be created. river engineering also handles sediment and erosion control, which can be a threat to humankind by destroying infrastructure, hindering water supply and causing major river cutoffs. river training structures will help to modify the hydraulic flow and the sediment response of a river. humans have modified the natural behavior of rivers for longer than history is recorded. the management of water resources, protection against floods and hydropower are not new concepts. regardless, river engineering has changed in the past century because of environmental concerns. the available amount and type of data about rivers has increased which provides more useful information about the behaviour of rivers and their ecosystems. engineering experts are able to analyse and adapt in a more environmentally conscious way. renaturalisation projects raise more awareness for the environment, however, rapidly growing and urbanizing
change has resulted in less water available for rivers during the summer. regulation of pollution, dam removal, and sewage treatment have helped to improve water quality and restore river habitats. certain organisms such as sponges and fungi are useful bioindicators for river health. = = topography = = = = = definition = = = a river is a natural flow of freshwater that flows on or through land towards another body of water downhill. this flow can be into a lake, an ocean, or another river. a stream refers to water that flows in a natural channel, a geographic feature that can contain flowing water. a stream may also be referred to as a watercourse. the study of the movement of water as it occurs on earth is called hydrology, and their effect on the landscape is covered by geomorphology. = = = source and drainage basin = = = rivers are part of the water cycle, the continuous processes by which water moves about earth. this means that all water that flows in rivers must ultimately come from precipitation. the sides of rivers have land that is at a higher elevation than the river itself, and in these areas, water flows downhill into the river. the headwaters of a river are the smaller streams that feed a river, and make up the river's source. these streams may be small and flow rapidly down the sides of mountains. all of the land uphill of a river that feeds it with water in this way is in that river's drainage basin or watershed. a ridge of higher elevation land is what typically separates drainage basins ; water on one side of a ridge will flow into one set of rivers, and water on the other side will flow into another. one example of this is the continental divide of the americas in the rocky mountains. water on the western side of the divide flows into the pacific ocean, whereas water on the other side flows into the atlantic ocean. not all precipitation flows directly into rivers ; some water seeps into underground aquifers. these, in turn, can still feed rivers via the water table, the groundwater beneath the surface of the land stored in the soil. water flows into rivers in places where the river's elevation is lower than that of the water table. this phenomenon is why rivers can still flow even during times of drought. rivers are also fed by the melting of snow glaciers present in higher elevation regions. in summer months, higher temperatures melt snow and ice, causing additional water to flow into rivers. glacier melt can supplement snow melt in times like the late summer,
##logists to understand the health of its ecosystems, the rate of erosion of the river's environment, and the effects of human activity. rivers rarely run in a straight direction, instead preferring to bend or meander. this is because any natural impediment to the flow of the river may cause the current to deflect in a different direction. when this happens, the alluvium carried by the river can build up against this impediment, redirecting the course of the river. the flow is then directed against the opposite bank of the river, which will erode into a more concave shape to accommodate the flow. the bank will still block the flow, causing it to reflect in the other direction. thus, a bend in the river is created. rivers may run through low, flat regions on their way to the sea. these places may have floodplains that are periodically flooded when there is a high level of water running through the river. these events may be referred to as " wet seasons'and " dry seasons " when the flooding is predictable due to the climate. the alluvium carried by rivers, laden with minerals, is deposited into the floodplain when the banks spill over, providing new nutrients to the soil, allowing them to support human activity like farming as well as a host of plant and animal life. deposited sediment from rivers can form temporary or long - lasting fluvial islands. these islands exist in almost every river. = = = = non - perennial rivers = = = = about half of all waterways on earth are intermittent rivers, which do not always have a continuous flow of water throughout the year. this may be because an arid climate is too dry depending on the season to support a stream, or because a river is seasonally frozen in the winter ( such as in an area with substantial permafrost ), or in the headwaters of rivers in mountains, where snowmelt is required to fuel the river. these rivers can appear in a variety of climates, and still provide a habitat for aquatic life and perform other ecological functions. = = = = subterranean rivers = = = = subterranean rivers may flow underground through flooded caves. this can happen in karst systems, where rock dissolves to form caves. these rivers provide a habitat for diverse microorganisms and have become an important target of study by microbiologists. other rivers and streams have been covered over or converted to run in tunnels due to human development. these rivers do not typically host any life, and are
Answer:
|
animals
| 0.3 |
Plants are like all other organisms, in that they need what to survive?
0. sustenance
1. shoes
2. games
3. internet
use these relationships between fungi and plants to make crops more thermo - tolerant, allowing them to resist damage by heat. the most famous of these ecological groups of organisms are : deinococcota, including thermus aquaticus, a species of bacteria. cyanobacteria, blue - green algae. oscillatoria terebriformis oscillatoria brevis heterohormogonium ( motile cell filaments formed by cyanobacteria ) synechococcus elongatus scytonema panic grass ( panic grass with a fungal association with curvularia ) = = see also = = thermophylae cyanobacteria thermophylae cyanobacteria mycovirus algae curvularia protuberata = = references = =
space. they form an essential part of the planetary ecosystem. however, some microorganisms are pathogenic and can post health risk to other organisms. viruses are infectious agents, but they are not autonomous life forms, as it is the case for viroids, satellites, dpis and prions. = = = plants and animals = = = originally aristotle divided all living things between plants, which generally do not move fast enough for humans to notice, and animals. in linnaeus'system, these became the kingdoms vegetabilia ( later plantae ) and animalia. since then, it has become clear that the plantae as originally defined included several unrelated groups, and the fungi and several groups of algae were removed to new kingdoms. however, these are still often considered plants in many contexts. bacterial life is sometimes included in flora, and some classifications use the term bacterial flora separately from plant flora. among the many ways of classifying plants are by regional floras, which, depending on the purpose of study, can also include fossil flora, remnants of plant life from a previous era. people in many regions and countries take great pride in their individual arrays of characteristic flora, which can vary widely across the globe due to differences in climate and terrain. regional floras commonly are divided into categories such as native flora or agricultural and garden flora. some types of " native flora " actually have been introduced centuries ago by people migrating from one region or continent to another, and become an integral part of the native, or natural flora of the place to which they were introduced. this is an example of how human interaction with nature can blur the boundary of what is considered nature. another category of plant has historically been carved out for weeds. though the term has fallen into disfavor among botanists as a formal way to categorize " useless " plants, the informal use of the word " weeds " to describe those plants that are deemed worthy of elimination is illustrative of the general tendency of people and societies to seek to alter or shape the course of nature. similarly, animals are often categorized in ways such as domestic, farm animals, wild animals, pests, etc. according to their relationship to human life. animals as a category have several characteristics that generally set them apart from other living things. animals are eukaryotic and usually multicellular, which separates them from bacteria, archaea, and most protists. they are heterotrophic, generally digesting food in an internal chamber, which separates them from plants and algae
space. they form an essential part of the planetary ecosystem. however, some microorganisms are pathogenic and can post health risk to other organisms. viruses are infectious agents, but they are not autonomous life forms, as it is the case for viroids, satellites, dpis and prions. = = = plants and animals = = = originally aristotle divided all living things between plants, which generally do not move fast enough for humans to notice, and animals. in linnaeus'system, these became the kingdoms vegetabilia ( later plantae ) and animalia. since then, it has become clear that the plantae as originally defined included several unrelated groups, and the fungi and several groups of algae were removed to new kingdoms. however, these are still often considered plants in many contexts. bacterial life is sometimes included in flora, and some classifications use the term bacterial flora separately from plant flora. among the many ways of classifying plants are by regional floras, which, depending on the purpose of study, can also include fossil flora, remnants of plant life from a previous era. people in many regions and countries take great pride in their individual arrays of characteristic flora, which can vary widely across the globe due to differences in climate and terrain. regional floras commonly are divided into categories such as native flora or agricultural and garden flora. some types of " native flora " actually have been introduced centuries ago by people migrating from one region or continent to another, and become an integral part of the native, or natural flora of the place to which they were introduced. this is an example of how human interaction with nature can blur the boundary of what is considered nature. another category of plant has historically been carved out for weeds. though the term has fallen into disfavor among botanists as a formal way to categorize " useless " plants, the informal use of the word " weeds " to describe those plants that are deemed worthy of elimination is illustrative of the general tendency of people and societies to seek to alter or shape the course of nature. similarly, animals are often categorized in ways such as domestic, farm animals, wild animals, pests, etc. according to their relationship to human life. animals as a category have several characteristics that generally set them apart from other living things. animals are eukaryotic and usually multicellular, which separates them from bacteria, archaea, and most protists. they are heterotrophic, generally digesting food in an internal chamber, which separates them from plants and algae
reproduction. because viruses possess some but not all characteristics of life, they have been described as " organisms at the edge of life ", and as self - replicators. = = ecology = = ecology is the study of the distribution and abundance of life, the interaction between organisms and their environment. = = = ecosystems = = = the community of living ( biotic ) organisms in conjunction with the nonliving ( abiotic ) components ( e. g., water, light, radiation, temperature, humidity, atmosphere, acidity, and soil ) of their environment is called an ecosystem. these biotic and abiotic components are linked together through nutrient cycles and energy flows. energy from the sun enters the system through photosynthesis and is incorporated into plant tissue. by feeding on plants and on one another, animals move matter and energy through the system. they also influence the quantity of plant and microbial biomass present. by breaking down dead organic matter, decomposers release carbon back to the atmosphere and facilitate nutrient cycling by converting nutrients stored in dead biomass back to a form that can be readily used by plants and other microbes. = = = populations = = = a population is the group of organisms of the same species that occupies an area and reproduce from generation to generation. population size can be estimated by multiplying population density by the area or volume. the carrying capacity of an environment is the maximum population size of a species that can be sustained by that specific environment, given the food, habitat, water, and other resources that are available. the carrying capacity of a population can be affected by changing environmental conditions such as changes in the availability of resources and the cost of maintaining them. in human populations, new technologies such as the green revolution have helped increase the earth's carrying capacity for humans over time, which has stymied the attempted predictions of impending population decline, the most famous of which was by thomas malthus in the 18th century. = = = communities = = = a community is a group of populations of species occupying the same geographical area at the same time. a biological interaction is the effect that a pair of organisms living together in a community have on each other. they can be either of the same species ( intraspecific interactions ), or of different species ( interspecific interactions ). these effects may be short - term, like pollination and predation, or long - term ; both often strongly influence the evolution of the species involved. a long - term interaction is called a symb
readily used by plants and microbes. ecosystems provide a variety of goods and services upon which people depend, and may be part of. ecosystem goods include the " tangible, material products " of ecosystem processes such as water, food, fuel, construction material, and medicinal plants. ecosystem services, on the other hand, are generally " improvements in the condition or location of things of value ". these include things like the maintenance of hydrological cycles, cleaning air and water, the maintenance of oxygen in the atmosphere, crop pollination and even things like beauty, inspiration and opportunities for research. many ecosystems become degraded through human impacts, such as soil loss, air and water pollution, habitat fragmentation, water diversion, fire suppression, and introduced species and invasive species. these threats can lead to abrupt transformation of the ecosystem or to gradual disruption of biotic processes and degradation of abiotic conditions of the ecosystem. once the original ecosystem has lost its defining features, it is considered " collapsed ". ecosystem restoration can contribute to achieving the sustainable development goals. = = definition = = an ecosystem ( or ecological system ) consists of all the organisms and the abiotic pools ( or physical environment ) with which they interact. : 5 : 458 the biotic and abiotic components are linked together through nutrient cycles and energy flows. " ecosystem processes " are the transfers of energy and materials from one pool to another. : 458 ecosystem processes are known to " take place at a wide range of scales ". therefore, the correct scale of study depends on the question asked. : 5 = = = origin and development of the term = = = the term " ecosystem " was first used in 1935 in a publication by british ecologist arthur tansley. the term was coined by arthur roy clapham, who came up with the word at tansley's request. tansley devised the concept to draw attention to the importance of transfers of materials between organisms and their environment. : 9 he later refined the term, describing it as " the whole system,... including not only the organism - complex, but also the whole complex of physical factors forming what we call the environment ". tansley regarded ecosystems not simply as natural units, but as " mental isolates ". tansley later defined the spatial extent of ecosystems using the term " ecotope ". g. evelyn hutchinson, a limnologist who was a contemporary of tansley's, combined charles elton's ideas about trophic ecology with those of russian geochemist vladimir vernadsky
Answer:
|
sustenance
| null |
Plants are like all other organisms, in that they need what to survive?
0. sustenance
1. shoes
2. games
3. internet
use these relationships between fungi and plants to make crops more thermo - tolerant, allowing them to resist damage by heat. the most famous of these ecological groups of organisms are : deinococcota, including thermus aquaticus, a species of bacteria. cyanobacteria, blue - green algae. oscillatoria terebriformis oscillatoria brevis heterohormogonium ( motile cell filaments formed by cyanobacteria ) synechococcus elongatus scytonema panic grass ( panic grass with a fungal association with curvularia ) = = see also = = thermophylae cyanobacteria thermophylae cyanobacteria mycovirus algae curvularia protuberata = = references = =
space. they form an essential part of the planetary ecosystem. however, some microorganisms are pathogenic and can post health risk to other organisms. viruses are infectious agents, but they are not autonomous life forms, as it is the case for viroids, satellites, dpis and prions. = = = plants and animals = = = originally aristotle divided all living things between plants, which generally do not move fast enough for humans to notice, and animals. in linnaeus'system, these became the kingdoms vegetabilia ( later plantae ) and animalia. since then, it has become clear that the plantae as originally defined included several unrelated groups, and the fungi and several groups of algae were removed to new kingdoms. however, these are still often considered plants in many contexts. bacterial life is sometimes included in flora, and some classifications use the term bacterial flora separately from plant flora. among the many ways of classifying plants are by regional floras, which, depending on the purpose of study, can also include fossil flora, remnants of plant life from a previous era. people in many regions and countries take great pride in their individual arrays of characteristic flora, which can vary widely across the globe due to differences in climate and terrain. regional floras commonly are divided into categories such as native flora or agricultural and garden flora. some types of " native flora " actually have been introduced centuries ago by people migrating from one region or continent to another, and become an integral part of the native, or natural flora of the place to which they were introduced. this is an example of how human interaction with nature can blur the boundary of what is considered nature. another category of plant has historically been carved out for weeds. though the term has fallen into disfavor among botanists as a formal way to categorize " useless " plants, the informal use of the word " weeds " to describe those plants that are deemed worthy of elimination is illustrative of the general tendency of people and societies to seek to alter or shape the course of nature. similarly, animals are often categorized in ways such as domestic, farm animals, wild animals, pests, etc. according to their relationship to human life. animals as a category have several characteristics that generally set them apart from other living things. animals are eukaryotic and usually multicellular, which separates them from bacteria, archaea, and most protists. they are heterotrophic, generally digesting food in an internal chamber, which separates them from plants and algae
space. they form an essential part of the planetary ecosystem. however, some microorganisms are pathogenic and can post health risk to other organisms. viruses are infectious agents, but they are not autonomous life forms, as it is the case for viroids, satellites, dpis and prions. = = = plants and animals = = = originally aristotle divided all living things between plants, which generally do not move fast enough for humans to notice, and animals. in linnaeus'system, these became the kingdoms vegetabilia ( later plantae ) and animalia. since then, it has become clear that the plantae as originally defined included several unrelated groups, and the fungi and several groups of algae were removed to new kingdoms. however, these are still often considered plants in many contexts. bacterial life is sometimes included in flora, and some classifications use the term bacterial flora separately from plant flora. among the many ways of classifying plants are by regional floras, which, depending on the purpose of study, can also include fossil flora, remnants of plant life from a previous era. people in many regions and countries take great pride in their individual arrays of characteristic flora, which can vary widely across the globe due to differences in climate and terrain. regional floras commonly are divided into categories such as native flora or agricultural and garden flora. some types of " native flora " actually have been introduced centuries ago by people migrating from one region or continent to another, and become an integral part of the native, or natural flora of the place to which they were introduced. this is an example of how human interaction with nature can blur the boundary of what is considered nature. another category of plant has historically been carved out for weeds. though the term has fallen into disfavor among botanists as a formal way to categorize " useless " plants, the informal use of the word " weeds " to describe those plants that are deemed worthy of elimination is illustrative of the general tendency of people and societies to seek to alter or shape the course of nature. similarly, animals are often categorized in ways such as domestic, farm animals, wild animals, pests, etc. according to their relationship to human life. animals as a category have several characteristics that generally set them apart from other living things. animals are eukaryotic and usually multicellular, which separates them from bacteria, archaea, and most protists. they are heterotrophic, generally digesting food in an internal chamber, which separates them from plants and algae
reproduction. because viruses possess some but not all characteristics of life, they have been described as " organisms at the edge of life ", and as self - replicators. = = ecology = = ecology is the study of the distribution and abundance of life, the interaction between organisms and their environment. = = = ecosystems = = = the community of living ( biotic ) organisms in conjunction with the nonliving ( abiotic ) components ( e. g., water, light, radiation, temperature, humidity, atmosphere, acidity, and soil ) of their environment is called an ecosystem. these biotic and abiotic components are linked together through nutrient cycles and energy flows. energy from the sun enters the system through photosynthesis and is incorporated into plant tissue. by feeding on plants and on one another, animals move matter and energy through the system. they also influence the quantity of plant and microbial biomass present. by breaking down dead organic matter, decomposers release carbon back to the atmosphere and facilitate nutrient cycling by converting nutrients stored in dead biomass back to a form that can be readily used by plants and other microbes. = = = populations = = = a population is the group of organisms of the same species that occupies an area and reproduce from generation to generation. population size can be estimated by multiplying population density by the area or volume. the carrying capacity of an environment is the maximum population size of a species that can be sustained by that specific environment, given the food, habitat, water, and other resources that are available. the carrying capacity of a population can be affected by changing environmental conditions such as changes in the availability of resources and the cost of maintaining them. in human populations, new technologies such as the green revolution have helped increase the earth's carrying capacity for humans over time, which has stymied the attempted predictions of impending population decline, the most famous of which was by thomas malthus in the 18th century. = = = communities = = = a community is a group of populations of species occupying the same geographical area at the same time. a biological interaction is the effect that a pair of organisms living together in a community have on each other. they can be either of the same species ( intraspecific interactions ), or of different species ( interspecific interactions ). these effects may be short - term, like pollination and predation, or long - term ; both often strongly influence the evolution of the species involved. a long - term interaction is called a symb
readily used by plants and microbes. ecosystems provide a variety of goods and services upon which people depend, and may be part of. ecosystem goods include the " tangible, material products " of ecosystem processes such as water, food, fuel, construction material, and medicinal plants. ecosystem services, on the other hand, are generally " improvements in the condition or location of things of value ". these include things like the maintenance of hydrological cycles, cleaning air and water, the maintenance of oxygen in the atmosphere, crop pollination and even things like beauty, inspiration and opportunities for research. many ecosystems become degraded through human impacts, such as soil loss, air and water pollution, habitat fragmentation, water diversion, fire suppression, and introduced species and invasive species. these threats can lead to abrupt transformation of the ecosystem or to gradual disruption of biotic processes and degradation of abiotic conditions of the ecosystem. once the original ecosystem has lost its defining features, it is considered " collapsed ". ecosystem restoration can contribute to achieving the sustainable development goals. = = definition = = an ecosystem ( or ecological system ) consists of all the organisms and the abiotic pools ( or physical environment ) with which they interact. : 5 : 458 the biotic and abiotic components are linked together through nutrient cycles and energy flows. " ecosystem processes " are the transfers of energy and materials from one pool to another. : 458 ecosystem processes are known to " take place at a wide range of scales ". therefore, the correct scale of study depends on the question asked. : 5 = = = origin and development of the term = = = the term " ecosystem " was first used in 1935 in a publication by british ecologist arthur tansley. the term was coined by arthur roy clapham, who came up with the word at tansley's request. tansley devised the concept to draw attention to the importance of transfers of materials between organisms and their environment. : 9 he later refined the term, describing it as " the whole system,... including not only the organism - complex, but also the whole complex of physical factors forming what we call the environment ". tansley regarded ecosystems not simply as natural units, but as " mental isolates ". tansley later defined the spatial extent of ecosystems using the term " ecotope ". g. evelyn hutchinson, a limnologist who was a contemporary of tansley's, combined charles elton's ideas about trophic ecology with those of russian geochemist vladimir vernadsky
Answer:
|
shoes
| 0.3 |
If a thistle is going to expand, it requires
0. hay
1. nutriment
2. cattle
3. seashells
which they were derived by the garton system of plant breeding. in making the selections the large quantity and superior quality of the grain, together with great standing power in the straw have been the chief characteristics aimed at, and if these desiderata have been secured in a few of the new breeds to the detriment of the habit of " tillering, " the difficulty is readily overcome by providing a liberal seeding. some of the most striking and valuable results have been achieved by introducing as progenitors, certain weeds belonging to the same natural order of plants as the cultivated parents. for example, an inferior variety of " spelt " wheat triticum spelta from southern asia, has been employed with excellent results to introduce strength of gluten to the grain, and large yielding and standing power to the crop with immunity from shedding its seed during harvest. a wild naked oat, avena nuda, indigenous to china has been used to produce new breeds which yield in some instances 100 per cent. more than their cultivated parents. four or five grains are suspended in each spikelet by a thread like filament about half - an - inch long. this peculiar habit of the plant'has been extended in the progeny and an'accompanying illustration shows a spikelet with no fewer than 14 grains in it. the hardiness of constitution, standing power of straw, and remarkable fertility of the wild or land oat, avena fatua, of great britain have been successfully introduced, but not without many difficulties, into some of the new breeds. some progress has also been made with the improvement of existing varieties of agricultural plants by introducing pollen from plants of the same variety to increase the vigour of the plant without materially altering its general characteristics. = = varieties bred and introduced = = source : barley varieties : barley varieties bred and introduced to uk agriculture include standwell in 1898, invincible ( 1899 ), zero ( 1900 ), brewer's favourite ( 1901 ), the maltster ( 1903 ), eclipse ( 1904 ), ideal ( 1906 ), 1917 ( 1918 ), admiral beatty ( 1920 ), triumphant ( 1927 ). oat varieties : oat varieties bred and introduced to uk agriculture include abundance in 1892, pioneer ( 1899 ), tartar king ( 1899 ), waverley ( 1900 ), goldfinder ( 1901 ), storm king ( 1902 ), excelsior ( 1903 ), colossal ( 1904 ), rival ( 1906 ), unversed ( 1907 ), bountiful
life in being thus exploited ; for example, the flattened pile of residue from the 11 / 19 site of loos - en - gohelle. conversely, others are painstakingly preserved on account of their ecological wealth. with the passage of time, they become colonised with a variety of flora and fauna, sometimes foreign to the region. this diversity follows the mining exploitation. in south wales some spoil tips are protected as sites of special scientific interest because they provide a unique habitat for 57 species of lichen, several of which are at risk due to their limited environment being developed and by vegetation development. for example, because the miners threw their apple or pear cores into the wagons, the spoil tips became colonised with fruit trees. one can even observe the proliferation of buckler - leaved sorrel ( french sorrel β rumex scutatus ), the seeds of which have been carried within the cracks in the pine timber used in the mines. furthermore, on account of its dark colour, the south face of the spoil tip is significantly warmer than its surroundings, which contributes to the diverse ecology of the area. in this way, the spoil tip of pinchonvalles, at avion, hosts 522 different varieties of higher plants. some sixty species of birds nest there. some are used to cultivate vines, as in the case of spoil tip no. 7 of the coal - mining region of mariemont - bascoup near chapelle - lez - herlaimont ( province of hainaut ). it produces some 3, 000 litres of wine each year from a vineyard on its slopes. some spoil tips are used for various sporting activities. the slopes of the spoil tips of 11 / 19 at loos - en - gohelle, or again, at nΕux - les - mines, are used for winter sports, for example ski and luge. a piste was built on the flank of the heap. in belgium, a long distance footpath along the spoil tips ( gr - 412, sentier des terrils ) was opened in 2005. it leads from bernissart in western hainaut to blegny in the province of liege. in the united states, coal mining companies have not been allowed to leave behind abandoned piles since the surface mining control and reclamation act was passed in 1977. the virginia city hybrid energy center uses coal gob as a fuel source for energy production. = = examples = = one of the highest, at least in western europe, is in loos - en
of the technique. a few university student projects have investigated hugelkultur, but those results have not made it into the peer - reviewed literature. one small scale and short term student project investigated the hugelkultur method as a potential use for yard trimmings waste, and also if lima beans, kale and okra planted on a hugelkultur mound showed any signs of nutrient deficiency compared to a non - raised control bed. it was found that over 11 tons of yard trimmings were used in the mound, and no evidence of macronutrient deficiency could be detected in the crops in the short term. indeed, despite concerns that incorporation of large quantities of high carbon woody matter would lead to nitrogen immobilization and hence nitrogen deficiency in the crop, a higher level of nitrogen was found in the raised bed. however, the micronutrient iron was lower relative to the control bed. the author speculated that no nitrogen deficiency occurred since the roots of the plants did not penetrate past the superficial layers of the mound into the deeper wood - containing region. a student thesis investigated the water holding capacity of hugelkultur beds and whether the technique could be useful to prevent karst rocky desertification in china. over 3 months of measurements, water concentration in hugel mounds remained high. samples from hugel sites contained almost twice as much water as those from flat control plots. it was suggested that 1 ha ( 2 + 1β2 acres ) of hugels has 3 - 10 times more water than a flat plot affected by karst rocky desertification. a 2024 study comparing different permaculture approaches found increased carbon content in soils treated with hugelkultur, and reduce waterlogging. combined with prior results regarding the improvement of water holding capacity in china, these results suggest that hugelkultur could be a valuable natural soil conditioner. = = theory = = many publications and websites advocate the technique based on personal experience of the authors. some have criticised the technique as lacking genuine scientific principles, and running counter to the ecological principles of soil building with litterfall. hugelkultur is said to replicate the natural process of decomposition that occurs on forest floors, however in natural ecosystems wood would be present at the soil surface. trees that fall in a forest often become nurse logs decaying and providing ecological facilitation to seedlings. as the wood decays, its porosity increases, allowing it to store water like a sponge. the water is slowly released back into the environment, benefiting nearby
amount of time after deposition, sufficient to allow the establishment of relatively unpalatable species such as rushes, nettles and hummocks of tall grasses like tussock grass. these swards, in turn, provide protection for thorny shrubs such as blackthorn, roses, hawthorn, juniper, bramble, holly and barberry during their early years, when they do not yet have protective thorns and are therefore vulnerable. once the thorny saplings are fully established, they grow bigger over time and subsequently allow other, less resilient species to establish in their thorn protection, forming mantle and fringe vegetation together with species such as guelder rose, wild privet and dogwood. other species such as mazzard, checker tree, rowan and whitebeam, which are distributed by fruit - eating birds through their faeces, would also frequently be placed within these shrubs, through resting birds leaving their droppings. on the other hand, nut - bearing species such as hazel, beech, chestnut, pedunculate and sessile oak would become " planted " somewhat deliberately in the vicinity of those shrubs by rodents such as red squirrel and wood mouse, the nuthatch and corvids such as crows, magpies, ravens and especially jays, which store them for winter supply. in europe, the eurasian jay represents the most important seed disperser of oak, burying acorns individually or in small groups. eurasian jays not only bury acorns in depths favoured by oak saplings, but seemingly also prefer spots with sufficient light availability, i. e. open grassland and transitions between grassland and shrubland, seeking for vertical structures such as shrubs in the near surroundings. since oak is relatively light - demanding while not having the ability to regenerate on its own under high browsing pressure, these habits of the jay presumably benefit oak, since they provide the conditions oak requires for optimal growth and health. on a similar note, the nuthatch seems to assume a prominent role for hazel dispersal. in addition, species such as wild pear, crab apple and whitty pear, which bear relatively large fruit, would find propagators in herbivores such as roe deer, red deer and cattle, or in omnivores such as the wild boar, red fox, the european badger and the raccoon, while wind - dispersed species such as maple, elm, lime or ash would land within these shrubs by chance. thorny bushes play an important role in tree regeneration in the european lowlands,
), gartons tall fescue ( 1955 ), marbury meadow fescue ( 1957 ), barmere timothy ( 1958 ). clover varieties : clover varieties bred and introduced to uk agriculture include giant cowgrass in 1898, perennial cowgrass ( 1898 ), perennialized broad red clover ( 1898 ), gartons white clover ( 1898 ) and broad red clover ( 1907 ). field cabbage varieties : field cabbage varieties bred and introduced to uk agriculture include early ox heart in 1900, extra early express ( 1900 ), early drumhead ( 1900 ), selected drumhead savoy ( 1902 ), selected ormskirk savoy ( 1902 ), gartons cattle drumhead ( 1904 ), giant purple flat poll ( 1917 ), utility ( 1924 ), intermediate drumhead ( 1924 ), gartons primo ( 1939 ). field carrot varieties : field carrot varieties bred and introduced to uk agriculture include scarlet intermediate in 1900, mid season scarlet ( 1911 ), mammoth white ( 1924 ), intermediate stump rooted ( 1935 ), red cored early market ( 1935 ), short stump rooted ( 1938 ), giant white ( 1939 ). lupin, parsnip, potato, sprouting broccoli, winter beans and winter rye varieties : other crop varieties bred and introduced to uk agriculture include gartons lupin in 1922, gartons field parsnips ( 1902 ), gartons number 12 potato ( 1912 ), gartons purple sprouting broccoli ( 1903 ), gartons giant winter bean ( 1922 ), gs giant winter bean ( 1950 ), p / l 14 giant winter bean ( 1954 ), gartons giant large grained winter rye ( 1922 ). = = references = =
Answer:
|
nutriment
| null |
If a thistle is going to expand, it requires
0. hay
1. nutriment
2. cattle
3. seashells
which they were derived by the garton system of plant breeding. in making the selections the large quantity and superior quality of the grain, together with great standing power in the straw have been the chief characteristics aimed at, and if these desiderata have been secured in a few of the new breeds to the detriment of the habit of " tillering, " the difficulty is readily overcome by providing a liberal seeding. some of the most striking and valuable results have been achieved by introducing as progenitors, certain weeds belonging to the same natural order of plants as the cultivated parents. for example, an inferior variety of " spelt " wheat triticum spelta from southern asia, has been employed with excellent results to introduce strength of gluten to the grain, and large yielding and standing power to the crop with immunity from shedding its seed during harvest. a wild naked oat, avena nuda, indigenous to china has been used to produce new breeds which yield in some instances 100 per cent. more than their cultivated parents. four or five grains are suspended in each spikelet by a thread like filament about half - an - inch long. this peculiar habit of the plant'has been extended in the progeny and an'accompanying illustration shows a spikelet with no fewer than 14 grains in it. the hardiness of constitution, standing power of straw, and remarkable fertility of the wild or land oat, avena fatua, of great britain have been successfully introduced, but not without many difficulties, into some of the new breeds. some progress has also been made with the improvement of existing varieties of agricultural plants by introducing pollen from plants of the same variety to increase the vigour of the plant without materially altering its general characteristics. = = varieties bred and introduced = = source : barley varieties : barley varieties bred and introduced to uk agriculture include standwell in 1898, invincible ( 1899 ), zero ( 1900 ), brewer's favourite ( 1901 ), the maltster ( 1903 ), eclipse ( 1904 ), ideal ( 1906 ), 1917 ( 1918 ), admiral beatty ( 1920 ), triumphant ( 1927 ). oat varieties : oat varieties bred and introduced to uk agriculture include abundance in 1892, pioneer ( 1899 ), tartar king ( 1899 ), waverley ( 1900 ), goldfinder ( 1901 ), storm king ( 1902 ), excelsior ( 1903 ), colossal ( 1904 ), rival ( 1906 ), unversed ( 1907 ), bountiful
life in being thus exploited ; for example, the flattened pile of residue from the 11 / 19 site of loos - en - gohelle. conversely, others are painstakingly preserved on account of their ecological wealth. with the passage of time, they become colonised with a variety of flora and fauna, sometimes foreign to the region. this diversity follows the mining exploitation. in south wales some spoil tips are protected as sites of special scientific interest because they provide a unique habitat for 57 species of lichen, several of which are at risk due to their limited environment being developed and by vegetation development. for example, because the miners threw their apple or pear cores into the wagons, the spoil tips became colonised with fruit trees. one can even observe the proliferation of buckler - leaved sorrel ( french sorrel β rumex scutatus ), the seeds of which have been carried within the cracks in the pine timber used in the mines. furthermore, on account of its dark colour, the south face of the spoil tip is significantly warmer than its surroundings, which contributes to the diverse ecology of the area. in this way, the spoil tip of pinchonvalles, at avion, hosts 522 different varieties of higher plants. some sixty species of birds nest there. some are used to cultivate vines, as in the case of spoil tip no. 7 of the coal - mining region of mariemont - bascoup near chapelle - lez - herlaimont ( province of hainaut ). it produces some 3, 000 litres of wine each year from a vineyard on its slopes. some spoil tips are used for various sporting activities. the slopes of the spoil tips of 11 / 19 at loos - en - gohelle, or again, at nΕux - les - mines, are used for winter sports, for example ski and luge. a piste was built on the flank of the heap. in belgium, a long distance footpath along the spoil tips ( gr - 412, sentier des terrils ) was opened in 2005. it leads from bernissart in western hainaut to blegny in the province of liege. in the united states, coal mining companies have not been allowed to leave behind abandoned piles since the surface mining control and reclamation act was passed in 1977. the virginia city hybrid energy center uses coal gob as a fuel source for energy production. = = examples = = one of the highest, at least in western europe, is in loos - en
of the technique. a few university student projects have investigated hugelkultur, but those results have not made it into the peer - reviewed literature. one small scale and short term student project investigated the hugelkultur method as a potential use for yard trimmings waste, and also if lima beans, kale and okra planted on a hugelkultur mound showed any signs of nutrient deficiency compared to a non - raised control bed. it was found that over 11 tons of yard trimmings were used in the mound, and no evidence of macronutrient deficiency could be detected in the crops in the short term. indeed, despite concerns that incorporation of large quantities of high carbon woody matter would lead to nitrogen immobilization and hence nitrogen deficiency in the crop, a higher level of nitrogen was found in the raised bed. however, the micronutrient iron was lower relative to the control bed. the author speculated that no nitrogen deficiency occurred since the roots of the plants did not penetrate past the superficial layers of the mound into the deeper wood - containing region. a student thesis investigated the water holding capacity of hugelkultur beds and whether the technique could be useful to prevent karst rocky desertification in china. over 3 months of measurements, water concentration in hugel mounds remained high. samples from hugel sites contained almost twice as much water as those from flat control plots. it was suggested that 1 ha ( 2 + 1β2 acres ) of hugels has 3 - 10 times more water than a flat plot affected by karst rocky desertification. a 2024 study comparing different permaculture approaches found increased carbon content in soils treated with hugelkultur, and reduce waterlogging. combined with prior results regarding the improvement of water holding capacity in china, these results suggest that hugelkultur could be a valuable natural soil conditioner. = = theory = = many publications and websites advocate the technique based on personal experience of the authors. some have criticised the technique as lacking genuine scientific principles, and running counter to the ecological principles of soil building with litterfall. hugelkultur is said to replicate the natural process of decomposition that occurs on forest floors, however in natural ecosystems wood would be present at the soil surface. trees that fall in a forest often become nurse logs decaying and providing ecological facilitation to seedlings. as the wood decays, its porosity increases, allowing it to store water like a sponge. the water is slowly released back into the environment, benefiting nearby
amount of time after deposition, sufficient to allow the establishment of relatively unpalatable species such as rushes, nettles and hummocks of tall grasses like tussock grass. these swards, in turn, provide protection for thorny shrubs such as blackthorn, roses, hawthorn, juniper, bramble, holly and barberry during their early years, when they do not yet have protective thorns and are therefore vulnerable. once the thorny saplings are fully established, they grow bigger over time and subsequently allow other, less resilient species to establish in their thorn protection, forming mantle and fringe vegetation together with species such as guelder rose, wild privet and dogwood. other species such as mazzard, checker tree, rowan and whitebeam, which are distributed by fruit - eating birds through their faeces, would also frequently be placed within these shrubs, through resting birds leaving their droppings. on the other hand, nut - bearing species such as hazel, beech, chestnut, pedunculate and sessile oak would become " planted " somewhat deliberately in the vicinity of those shrubs by rodents such as red squirrel and wood mouse, the nuthatch and corvids such as crows, magpies, ravens and especially jays, which store them for winter supply. in europe, the eurasian jay represents the most important seed disperser of oak, burying acorns individually or in small groups. eurasian jays not only bury acorns in depths favoured by oak saplings, but seemingly also prefer spots with sufficient light availability, i. e. open grassland and transitions between grassland and shrubland, seeking for vertical structures such as shrubs in the near surroundings. since oak is relatively light - demanding while not having the ability to regenerate on its own under high browsing pressure, these habits of the jay presumably benefit oak, since they provide the conditions oak requires for optimal growth and health. on a similar note, the nuthatch seems to assume a prominent role for hazel dispersal. in addition, species such as wild pear, crab apple and whitty pear, which bear relatively large fruit, would find propagators in herbivores such as roe deer, red deer and cattle, or in omnivores such as the wild boar, red fox, the european badger and the raccoon, while wind - dispersed species such as maple, elm, lime or ash would land within these shrubs by chance. thorny bushes play an important role in tree regeneration in the european lowlands,
), gartons tall fescue ( 1955 ), marbury meadow fescue ( 1957 ), barmere timothy ( 1958 ). clover varieties : clover varieties bred and introduced to uk agriculture include giant cowgrass in 1898, perennial cowgrass ( 1898 ), perennialized broad red clover ( 1898 ), gartons white clover ( 1898 ) and broad red clover ( 1907 ). field cabbage varieties : field cabbage varieties bred and introduced to uk agriculture include early ox heart in 1900, extra early express ( 1900 ), early drumhead ( 1900 ), selected drumhead savoy ( 1902 ), selected ormskirk savoy ( 1902 ), gartons cattle drumhead ( 1904 ), giant purple flat poll ( 1917 ), utility ( 1924 ), intermediate drumhead ( 1924 ), gartons primo ( 1939 ). field carrot varieties : field carrot varieties bred and introduced to uk agriculture include scarlet intermediate in 1900, mid season scarlet ( 1911 ), mammoth white ( 1924 ), intermediate stump rooted ( 1935 ), red cored early market ( 1935 ), short stump rooted ( 1938 ), giant white ( 1939 ). lupin, parsnip, potato, sprouting broccoli, winter beans and winter rye varieties : other crop varieties bred and introduced to uk agriculture include gartons lupin in 1922, gartons field parsnips ( 1902 ), gartons number 12 potato ( 1912 ), gartons purple sprouting broccoli ( 1903 ), gartons giant winter bean ( 1922 ), gs giant winter bean ( 1950 ), p / l 14 giant winter bean ( 1954 ), gartons giant large grained winter rye ( 1922 ). = = references = =
Answer:
|
cattle
| 0.3 |
To create paper you will first have to acquire a supply of
0. stardust
1. sand
2. pens
3. pulp
paper engineering is a branch of engineering that deals with the usage of physical science ( e. g. chemistry and physics ) and life sciences ( e. g. biology and biochemistry ) in conjunction with mathematics as applied to the converting of raw materials into useful paper products and co - products. the field applies various principles in process engineering and unit operations to the manufacture of paper, chemicals, energy and related materials. the following timeline shows some of the key steps in the development of the science of chemical and bioprocess engineering : from a heritage perspective, the field encompasses the design and analysis of a wide variety of thermal, chemical and biochemical unit operations employed in the manufacture of pulp and paper, and addresses the preparation of its raw materials from trees or other natural resources via a pulping process, chemical and mechanical pretreatment of these recovered biopolymer ( e. g. principally, although not solely, cellulose - based ) fibers in a fluid suspension, the high - speed forming and initial dewatering of a non - woven web, the development of bulk sheet properties via control of energy and mass transfer operations, as well as post - treatment of the sheet with coating, calendering, and other chemical and mechanical processes. = = applications = = today, the field of paper and chemical engineering is applied to the manufacture of a wide variety of products. the forestry and biology, chemical science, ( bio ) chemical industry scope manufactures organic and agrochemicals ( fertilizers, insecticides, herbicides ), oleochemicals, fragrances and flavors, food, feed, pharmaceuticals, nutraceuticals, chemicals, polymers and power from biological materials. the resulting products of paper engineering including paper, cardboard, and various paper derivatives are widely used in everyday life. in addition to being a subset of chemical engineering, the field of paper engineering is closely linked to forest management, product recycling, and the mass production of paper β based media. = = methods = = = = = mechanical pulping = = = in the process of mechanical pulping, " grinding " and " refining " are the two main methods used to create the pulp. grinding is the method of pressing logs and chips against a turning stone to produce fibers. refiner pulping is treating wood chips with chemicals or heat and then crushing the objects between two disks, one or both of which are rotating. there are four main types of refiner pulping, which includes refiner mechanical pulping, thermo - mechanical pulping
, and ideal for hot environments. a mixture of sand, clay, and water is poured into a mold and left in the sun to dry. when dried, it is exceptionally strong and heat - resistant. adobe does not let much heat through to the inside of the structure, thus providing excellent insulation during the summer to reduce energy costs. although this clay mixture provides excellent insulation from heat, it is not very waterproof and can be dangerous in earthquake prone areas due to its tendency to crack easily. = = = sawdust = = = sawdust can be combined with clay or cement mixtures and used for walls. such walls are very sturdy and the method effectively recycles any trees needing excavation from the building area. depending what type of sawdust is used ( hardwood is best ) the wood chips in the walls absorb moisture and help prevent cracking during freeze and thaw cycles. sawdust may be combined with water and frozen to produce a material commonly known as pykrete, which is strong, and less prone to melting than regular ice. = = = papercrete = = = papercrete is a new material that serves as a good substitute for concrete. papercrete is shredded paper, sand, and cement mixed together to form a very durable brick - like material. buildings utilizing papercrete are well - insulated and resistant to termites and fire. papercrete is very cheap as it usually only costs about $ 0. 35 per square foot. = = = hempcrete = = = hempcrete, also known as hemplime, is a sustainable biocomposite composed of hemp hurds mixed with lime, sand, or pozzolans material used in construction and insulation. the material offers advantages such as ease of use, insulation, and moisture regulation without the brittleness of traditional concrete. however, it exhibits low mechanical performance and is not suitable for load - bearing structures. it has good thermal and acoustic insulation properties, making it suitable for ( non - load bearing ) walls, finishing plaster, and insulation. it also acts as a carbon sink. hempcrete gained popularity in france since the 1990s, and is used in canada for various construction purposes, such as indoor temperature control, prefabricated panels, and diverse insulation needs with different density mixtures. = = see also = = green building β structures and processes of building structures that are more environmentally responsible green building and wood green roof β roof that is covered with vegetation and a growing substrate hemp as a building material
filter paper is a semi - permeable paper barrier placed perpendicular to a liquid or air flow. it is used to separate fine solid particles from liquids or gases. the raw materials are typically different paper pulps. the pulp may be made from softwood, hardwood, fiber crops, or mineral fibers. = = properties = = filter paper has various properties. the important parameters are wet strength, porosity, particle retention, volumetric flow rate, compatibility, efficiency and capacity. there are two mechanisms of filtration with paper ; volume, and surface. by volume filtration, the particles are caught in the bulk of the filter paper. by surface filtration, the particles are caught on the paper surface. filter paper is mostly used because of the ability of a small piece of filter paper to absorb a significant volume of liquid. = = manufacture = = the raw materials are different paper pulps. the pulp may be from softwood, hardwood, fiber crops, mineral fibers. for high quality filters, dissolving pulp and mercerised pulp are used. most filter papers are made using small paper machines. for laboratory filters, the machines may be as small as 50 cm in width. the paper is often creped to improve porosity. the filter papers may also be treated with reagents or impregnation to get the right properties. = = types = = = = = air filters = = = the main application for air filters are combustion air to engines. the filter papers are transformed into filter cartridges, which then is fitted to a holder. the construction of the cartridges mostly requires that the paper is stiff enough to be self - supporting. a paper for air filters needs to be very porous and have a weight of 100 β 200 g / m2. normally particularly long fibrous pulp that is mercerised is used to get these properties. the paper is normally impregnated to improve the resistance to moisture. : 113 some heavy duty qualities are made to be rinsed and thereby extend the life of the filter. = = = coffee and tea = = = historically, blotting paper or cloth were used to extract filter coffee. modern coffee filters of paper are made from about 100 g / m2 creped paper. the creping allows the coffee to flow freely between the filter and the filtration funnel. the raw materials ( pulp ) for the filter paper are coarse long fiber, often from fast growing trees. for example, melitta uses up to 60 % of bambus in
treating wood chips with chemicals or heat and then crushing the objects between two disks, one or both of which are rotating. there are four main types of refiner pulping, which includes refiner mechanical pulping, thermo - mechanical pulping, chemi - mechanical pulping, and chemithermomechanical pulping. further descriptions of each process are contained in this link : mechanical pulping, when compared to chemical pulping, is relatively inexpensive and has a high pulp yield ( 85 β 95 % ). however, the paper created is generally weak since it retains the lignin. = = = chemical pulping = = = the process of chemical pulping is used to chemically disband the lignin found in the cell walls of the material undergoing the process. after the cellulose fibers are separated from the lignin, a pulp is created which can then be treated to create durable paper, boxes, and corrugated cardboard. chemical pulping can be characterized by two main methods : sulfate ( kraft process ) pulping and sulfite pulping, and these two methods have different benefits. sulfate pulping can be performed on a wide range of tree varieties and results in the creation of a strong type of paper. conversely, sulfite pulping results in a higher volume of pulp which is easier to bleach and process. however, sulfate pulping is more widely used since the product is more durable and the chemicals used in the process can be recovered, thus resulting in minimal environmental pollution. = = = further pulp processing = = = the pulp is then processed through an apparatus which renders the pulp as a mesh of fibers. this fiber network is then pressed to remove all water contents, and the paper is subsequently dried to remove all traces of moisture. = = = finishing = = = after the above processes have been completed, the resulting paper is coated with a minuscule amount of china clay or calcium carbonate to modify the surface, and the paper is then re - sized depending on its intended purpose. = = = product recycling = = = generally, the material to be recycled first undergoes mechanical or chemical pulping to render it in pulp form. the resulting pulp is then processed in the same way normal pulp is processed ; however, original fiber is sometimes added to enhance the quality and appearance of the product. = = related fields and topics = = today, the field of paper and bioprocess engineering is a diverse one, covering areas from biotechnology and nanotechnology to electricity generation.
nitrate is dissolved, forming particles with a diameter of about 5 nanometers. in order to enlarge the size of the particle to an average diameter of about 400 nanometers, the flask is placed on a heated sonicator, a device that produces high - intensity ultrasound. once cooled, the solution is poured into a larger flask and the thick precipitate, an insoluble solid which is formed is scraped out. from there, ethanol is added to coagulate the particles, or change the particles to a solid state. most of the supernatant, the liquid lying above a layer of the precipitate, is then poured out so the remaining liquid can be centrifuged, or separated. after the process of centrifugation, the particles are placed back in water and forced through a syringe filter to remove unnecessary particles in the solution. next, hydroxyethyl cellulose ( hec ) is added as a binder and the entire mixture is homogenized. the solvents are allowed to evaporate until the ink has a desired viscosity or thickness. once the ink is created, a roller ball pen is dismantled and cleaned so the ink can be placed inside using a flat tip spatula. after replacing the roller ball tip, a couple blasts of compressed air is shot from the back end to force the ink into the tip. the outer cover of the pen is replaced and the prototype of the circuit scribe is created. from there, the team launched its kickstarter campaign. = = = kickstarter campaign = = = circuit scribe launched its campaign on kickstarter to receive funding and included a list of pledges which people could donate a certain amount and get a corresponding gift : pledge $ 5 + : stem education workbook pledge $ 20 + : circuit scribe pledge $ 25 + : early bird basic kit pledge $ 30 + : basic kit pledge $ 35 + : early bird basic kit + book pledge $ 40 + : basic kit + book pledge $ 45 + : early bird maker kit pledge $ 50 + : maker kit pledge $ 90 + : gift pack pledge $ 100 + : developer kit pledge $ 175 + : circuit scribe bundle pledge $ 190 + : early bird classroom kit pledge $ 200 + : classroom kit pledge $ 500 + : component designer pledge $ 5, 000 + : electroninks show & tell they also included stretch goals which include : $ 250, 000 : circuit scribe edu platform & stem outreach $ 650, 000 : magnetic
Answer:
|
pulp
| null |
To create paper you will first have to acquire a supply of
0. stardust
1. sand
2. pens
3. pulp
paper engineering is a branch of engineering that deals with the usage of physical science ( e. g. chemistry and physics ) and life sciences ( e. g. biology and biochemistry ) in conjunction with mathematics as applied to the converting of raw materials into useful paper products and co - products. the field applies various principles in process engineering and unit operations to the manufacture of paper, chemicals, energy and related materials. the following timeline shows some of the key steps in the development of the science of chemical and bioprocess engineering : from a heritage perspective, the field encompasses the design and analysis of a wide variety of thermal, chemical and biochemical unit operations employed in the manufacture of pulp and paper, and addresses the preparation of its raw materials from trees or other natural resources via a pulping process, chemical and mechanical pretreatment of these recovered biopolymer ( e. g. principally, although not solely, cellulose - based ) fibers in a fluid suspension, the high - speed forming and initial dewatering of a non - woven web, the development of bulk sheet properties via control of energy and mass transfer operations, as well as post - treatment of the sheet with coating, calendering, and other chemical and mechanical processes. = = applications = = today, the field of paper and chemical engineering is applied to the manufacture of a wide variety of products. the forestry and biology, chemical science, ( bio ) chemical industry scope manufactures organic and agrochemicals ( fertilizers, insecticides, herbicides ), oleochemicals, fragrances and flavors, food, feed, pharmaceuticals, nutraceuticals, chemicals, polymers and power from biological materials. the resulting products of paper engineering including paper, cardboard, and various paper derivatives are widely used in everyday life. in addition to being a subset of chemical engineering, the field of paper engineering is closely linked to forest management, product recycling, and the mass production of paper β based media. = = methods = = = = = mechanical pulping = = = in the process of mechanical pulping, " grinding " and " refining " are the two main methods used to create the pulp. grinding is the method of pressing logs and chips against a turning stone to produce fibers. refiner pulping is treating wood chips with chemicals or heat and then crushing the objects between two disks, one or both of which are rotating. there are four main types of refiner pulping, which includes refiner mechanical pulping, thermo - mechanical pulping
, and ideal for hot environments. a mixture of sand, clay, and water is poured into a mold and left in the sun to dry. when dried, it is exceptionally strong and heat - resistant. adobe does not let much heat through to the inside of the structure, thus providing excellent insulation during the summer to reduce energy costs. although this clay mixture provides excellent insulation from heat, it is not very waterproof and can be dangerous in earthquake prone areas due to its tendency to crack easily. = = = sawdust = = = sawdust can be combined with clay or cement mixtures and used for walls. such walls are very sturdy and the method effectively recycles any trees needing excavation from the building area. depending what type of sawdust is used ( hardwood is best ) the wood chips in the walls absorb moisture and help prevent cracking during freeze and thaw cycles. sawdust may be combined with water and frozen to produce a material commonly known as pykrete, which is strong, and less prone to melting than regular ice. = = = papercrete = = = papercrete is a new material that serves as a good substitute for concrete. papercrete is shredded paper, sand, and cement mixed together to form a very durable brick - like material. buildings utilizing papercrete are well - insulated and resistant to termites and fire. papercrete is very cheap as it usually only costs about $ 0. 35 per square foot. = = = hempcrete = = = hempcrete, also known as hemplime, is a sustainable biocomposite composed of hemp hurds mixed with lime, sand, or pozzolans material used in construction and insulation. the material offers advantages such as ease of use, insulation, and moisture regulation without the brittleness of traditional concrete. however, it exhibits low mechanical performance and is not suitable for load - bearing structures. it has good thermal and acoustic insulation properties, making it suitable for ( non - load bearing ) walls, finishing plaster, and insulation. it also acts as a carbon sink. hempcrete gained popularity in france since the 1990s, and is used in canada for various construction purposes, such as indoor temperature control, prefabricated panels, and diverse insulation needs with different density mixtures. = = see also = = green building β structures and processes of building structures that are more environmentally responsible green building and wood green roof β roof that is covered with vegetation and a growing substrate hemp as a building material
filter paper is a semi - permeable paper barrier placed perpendicular to a liquid or air flow. it is used to separate fine solid particles from liquids or gases. the raw materials are typically different paper pulps. the pulp may be made from softwood, hardwood, fiber crops, or mineral fibers. = = properties = = filter paper has various properties. the important parameters are wet strength, porosity, particle retention, volumetric flow rate, compatibility, efficiency and capacity. there are two mechanisms of filtration with paper ; volume, and surface. by volume filtration, the particles are caught in the bulk of the filter paper. by surface filtration, the particles are caught on the paper surface. filter paper is mostly used because of the ability of a small piece of filter paper to absorb a significant volume of liquid. = = manufacture = = the raw materials are different paper pulps. the pulp may be from softwood, hardwood, fiber crops, mineral fibers. for high quality filters, dissolving pulp and mercerised pulp are used. most filter papers are made using small paper machines. for laboratory filters, the machines may be as small as 50 cm in width. the paper is often creped to improve porosity. the filter papers may also be treated with reagents or impregnation to get the right properties. = = types = = = = = air filters = = = the main application for air filters are combustion air to engines. the filter papers are transformed into filter cartridges, which then is fitted to a holder. the construction of the cartridges mostly requires that the paper is stiff enough to be self - supporting. a paper for air filters needs to be very porous and have a weight of 100 β 200 g / m2. normally particularly long fibrous pulp that is mercerised is used to get these properties. the paper is normally impregnated to improve the resistance to moisture. : 113 some heavy duty qualities are made to be rinsed and thereby extend the life of the filter. = = = coffee and tea = = = historically, blotting paper or cloth were used to extract filter coffee. modern coffee filters of paper are made from about 100 g / m2 creped paper. the creping allows the coffee to flow freely between the filter and the filtration funnel. the raw materials ( pulp ) for the filter paper are coarse long fiber, often from fast growing trees. for example, melitta uses up to 60 % of bambus in
treating wood chips with chemicals or heat and then crushing the objects between two disks, one or both of which are rotating. there are four main types of refiner pulping, which includes refiner mechanical pulping, thermo - mechanical pulping, chemi - mechanical pulping, and chemithermomechanical pulping. further descriptions of each process are contained in this link : mechanical pulping, when compared to chemical pulping, is relatively inexpensive and has a high pulp yield ( 85 β 95 % ). however, the paper created is generally weak since it retains the lignin. = = = chemical pulping = = = the process of chemical pulping is used to chemically disband the lignin found in the cell walls of the material undergoing the process. after the cellulose fibers are separated from the lignin, a pulp is created which can then be treated to create durable paper, boxes, and corrugated cardboard. chemical pulping can be characterized by two main methods : sulfate ( kraft process ) pulping and sulfite pulping, and these two methods have different benefits. sulfate pulping can be performed on a wide range of tree varieties and results in the creation of a strong type of paper. conversely, sulfite pulping results in a higher volume of pulp which is easier to bleach and process. however, sulfate pulping is more widely used since the product is more durable and the chemicals used in the process can be recovered, thus resulting in minimal environmental pollution. = = = further pulp processing = = = the pulp is then processed through an apparatus which renders the pulp as a mesh of fibers. this fiber network is then pressed to remove all water contents, and the paper is subsequently dried to remove all traces of moisture. = = = finishing = = = after the above processes have been completed, the resulting paper is coated with a minuscule amount of china clay or calcium carbonate to modify the surface, and the paper is then re - sized depending on its intended purpose. = = = product recycling = = = generally, the material to be recycled first undergoes mechanical or chemical pulping to render it in pulp form. the resulting pulp is then processed in the same way normal pulp is processed ; however, original fiber is sometimes added to enhance the quality and appearance of the product. = = related fields and topics = = today, the field of paper and bioprocess engineering is a diverse one, covering areas from biotechnology and nanotechnology to electricity generation.
nitrate is dissolved, forming particles with a diameter of about 5 nanometers. in order to enlarge the size of the particle to an average diameter of about 400 nanometers, the flask is placed on a heated sonicator, a device that produces high - intensity ultrasound. once cooled, the solution is poured into a larger flask and the thick precipitate, an insoluble solid which is formed is scraped out. from there, ethanol is added to coagulate the particles, or change the particles to a solid state. most of the supernatant, the liquid lying above a layer of the precipitate, is then poured out so the remaining liquid can be centrifuged, or separated. after the process of centrifugation, the particles are placed back in water and forced through a syringe filter to remove unnecessary particles in the solution. next, hydroxyethyl cellulose ( hec ) is added as a binder and the entire mixture is homogenized. the solvents are allowed to evaporate until the ink has a desired viscosity or thickness. once the ink is created, a roller ball pen is dismantled and cleaned so the ink can be placed inside using a flat tip spatula. after replacing the roller ball tip, a couple blasts of compressed air is shot from the back end to force the ink into the tip. the outer cover of the pen is replaced and the prototype of the circuit scribe is created. from there, the team launched its kickstarter campaign. = = = kickstarter campaign = = = circuit scribe launched its campaign on kickstarter to receive funding and included a list of pledges which people could donate a certain amount and get a corresponding gift : pledge $ 5 + : stem education workbook pledge $ 20 + : circuit scribe pledge $ 25 + : early bird basic kit pledge $ 30 + : basic kit pledge $ 35 + : early bird basic kit + book pledge $ 40 + : basic kit + book pledge $ 45 + : early bird maker kit pledge $ 50 + : maker kit pledge $ 90 + : gift pack pledge $ 100 + : developer kit pledge $ 175 + : circuit scribe bundle pledge $ 190 + : early bird classroom kit pledge $ 200 + : classroom kit pledge $ 500 + : component designer pledge $ 5, 000 + : electroninks show & tell they also included stretch goals which include : $ 250, 000 : circuit scribe edu platform & stem outreach $ 650, 000 : magnetic
Answer:
|
sand
| 0.3 |
A consequence of creating thousands of notebooks is
0. longer days
1. habitat change
2. lush landscapes
3. shorter days.
decision on the situation. once the situation has been assessed, the contractor makes the appropriate accommodations to not disturb the species. vegetation : there may be particular trees or other vegetation that must be protected on the job site. this may require fences or security tape to warn builders that they must not be harmed. wetlands : the contractor must make accommodations so that erosion and water flow are not affected by construction. any liquid spills must be maintained due to contaminants that may enter the wetland. historical or cultural artifacts : artifacts may include arrowheads, pottery shards, and bones. all work comes to a halt if any artifacts are found and will not resume until they can be properly examined and removed from the area. = = construction activity documentation = = project meetings take place at scheduled intervals to discuss the progress on the construction site and any concerns or issues. the discussion and any decisions made at the meeting must be documented. diaries, logs, and daily field reports keep track of the daily activities on a job site each day. diaries : each member of the project team is expected to keep a project diary. the diary contains summaries of the day's events in the member's own words. they are used to keep track of any daily work activity, conversations, observations, or any other relevant information regarding the construction activities. diaries can be referred to when disputes arise and a diary happens to contain information connected with the disagreement. diaries that are handwritten can be used as evidence in court. logs : logs keep track of the regular activities on the job site such as phone logs, transmittal logs, delivery logs, and request for information ( rfi ) logs. daily field reports : daily field reports are a more formal way of recording information on the job site. they contain information that includes the day's activities, temperature and weather conditions, delivered equipment or materials, visitors on the site, images of the job site and equipment used that day. labor statements are required on a daily basis. also list of labor, pert cpm are needed for labor planning to complete a project in time. = = resolving disputes = = mediation : mediation uses a third party mediator to resolve any disputes. the mediator helps both disputing parties to come to a mutual agreement. this cost - saving process ensures that no attorneys become involved in the dispute and is less time - consuming. minitrial : a minitrial takes more time and money than a mediation. the minitrial takes place in an informal setting and involves some type of advisor or
to changes in dispersal or movement of species including changes to seasonal migration. these changes can lead to a decrease in a density of species, increased competition or even increased predation. = = implications = = = = = habitat and biodiversity loss = = = one of the major ways that habitat fragmentation affects biodiversity is by reducing the amount of suitable habitat available for organisms. habitat fragmentation often involves both habitat destruction and the subdivision of previously continuous habitat. plants and other sessile organisms are disproportionately affected by some types of habitat fragmentation because they cannot respond quickly to the altered spatial configuration of the habitat. habitat fragmentation consistently reduces biodiversity by 13 to 75 % and impairs key ecosystem functions by decreasing biomass and altering nutrient cycles. this underscores the severe and lasting ecological impacts of fragmentation, which could be highlighted in the sections discussing the consequences of fragmentation. habitat loss, which can occur through the process of habitat fragmentation, is considered to be the greatest threat to species. but, the effect of the configuration of habitat patches within the landscape, independent of the effect of the amount of habitat within the landscape ( referred to as fragmentation per se ), has been suggested to be small. a review of empirical studies found that, of the 381 reported significant effect of habitat fragmentation per se on species occurrences, abundances or diversity in the scientific literature, 76 % were positive whereas 24 % were negative. despite these results, the scientific literature tends to emphasize negative effects more than positive effects. positive effects of habitat fragmentation per se imply that several small patches of habitat can have higher conservation value than a single large patch of equivalent size. land sharing strategies could therefore have more positive impacts on species than land sparing strategies. although the negative effects of habitat loss are generally viewed to be much larger than that of habitat fragmentation, the two events are heavily connected and observations are not usually independent of one another. area is the primary determinant of the number of species in a fragment and the relative contributions of demographic and genetic processes to the risk of global population extinction depend on habitat configuration, stochastic environmental variation and species features. minor fluctuations in climate, resources, or other factors that would be unremarkable and quickly corrected in large populations can be catastrophic in small, isolated populations. thus fragmentation of habitat is an important cause of species extinction. population dynamics of subdivided populations tend to vary asynchronously. in an unfragmented landscape a declining population can be " rescued " by immigration from a nearby expanding population. in fragmented landscapes, the distance between fragments
biodiversity is being destroyed at a rate unprecedented in human history ". the report claims that 68 % of the population of the examined species were destroyed in the years 1970 β 2016. of 70, 000 monitored species, around 48 % are experiencing population declines from human activity ( in 2023 ), whereas only 3 % have increasing populations. rates of decline in biodiversity in the current sixth mass extinction match or exceed rates of loss in the five previous mass extinction events in the fossil record. biodiversity loss is in fact " one of the most critical manifestations of the anthropocene " ( since around the 1950s ) ; the continued decline of biodiversity constitutes " an unprecedented threat " to the continued existence of human civilization. the reduction is caused primarily by human impacts, particularly habitat destruction. since the stone age, species loss has accelerated above the average basal rate, driven by human activity. estimates of species losses are at a rate 100 β 10, 000 times as fast as is typical in the fossil record. loss of biodiversity results in the loss of natural capital that supplies ecosystem goods and services. species today are being wiped out at a rate 100 to 1, 000 times higher than baseline, and the rate of extinctions is increasing. this process destroys the resilience and adaptability of life on earth. in 2006, many species were formally classified as rare or endangered or threatened ; moreover, scientists have estimated that millions more species are at risk which have not been formally recognized. about 40 percent of the 40, 177 species assessed using the iucn red list criteria are now listed as threatened with extinction β a total of 16, 119. as of late 2022 9251 species were considered part of the iucn's critically endangered. numerous scientists and the ipbes global assessment report on biodiversity and ecosystem services assert that human population growth and overconsumption are the primary factors in this decline. however, other scientists have criticized this finding and say that loss of habitat caused by " the growth of commodities for export " is the main driver. a 2025 study found that human activities are responsible for biodiversity loss across all species and ecosystems. some studies have however pointed out that habitat destruction for the expansion of agriculture and the overexploitation of wildlife are the more significant drivers of contemporary biodiversity loss, not climate change. = = distribution = = biodiversity is not evenly distributed, rather it varies greatly across the globe as well as within regions and seasons. among other factors, the diversity of all living things ( biota ) depends on temperature, precipitation, altitude, soils, geography and the
cause of species extinction. population dynamics of subdivided populations tend to vary asynchronously. in an unfragmented landscape a declining population can be " rescued " by immigration from a nearby expanding population. in fragmented landscapes, the distance between fragments may prevent this from happening. additionally, unoccupied fragments of habitat that are separated from a source of immigrants by some barrier are less likely to be repopulated than adjoining fragments. even small species such as the columbia spotted frog are reliant on the rescue effect. studies showed 25 % of juveniles travel a distance over 200m compared to 4 % of adults. of these, 95 % remain in their new locale, demonstrating that this journey is necessary for survival. additionally, habitat fragmentation leads to edge effects. microclimatic changes in light, temperature, and wind can alter the ecology around the fragment, and in the interior and exterior portions of the fragment. fires become more likely in the area as humidity drops and temperature and wind levels rise. exotic and pest species may establish themselves easily in such disturbed environments, and the proximity of domestic animals often upsets the natural ecology. also, habitat along the edge of a fragment has a different climate and favours different species from the interior habitat. small fragments are therefore unfavourable for species that require interior habitat. the percentage preservation of contiguous habitats is closely related to both genetic and species biodiversity preservation. generally a 10 % remnant contiguous habitat will result in a 50 % biodiversity loss. much of the remaining terrestrial wildlife habitat in many third world countries has experienced fragmentation through the development of urban expansion such as roads interfering with habitat loss. aquatic species β habitats have been fragmented by dams and water diversions. these fragments of habitat may not be large or connected enough to support species that need a large territory where they can find mates and food. the loss and fragmentation of habitats makes it difficult for migratory species to find places to rest and feed along their migration routes. the effects of current fragmentation will continue to emerge for decades. extinction debts are likely to come due, although the counteracting immigration debts may never fully be paid. indeed, the experiments here reveal ongoing losses of biodiversity and ecosystem functioning two decades or longer after fragmentation occurred. understanding the relationship between transient and long - term dynamics is a substantial challenge that ecologists must tackle, and fragmentation experiments will be central for relating observation to theory. = = = informed conservation = = = habitat fragmentation is often a cause of species becoming threatened or endangered. the existence of viable habitat is critical to the survival of
development, and climate change can impact the quality and distribution of habitats and necessitate the movement of species to new locations of suitable habitat. = = = incidental movement = = = movement of species in areas that are typically used by humans. these include greenbelts, recreational trail systems, hedgerows, and golf courses. = = connectivity conservation = = preserving or creating landscape connectivity has become increasingly recognized as a key strategy to protect biodiversity, maintain viable ecosystems and wildlife populations, and facilitate the movement and adaptation of wildlife populations in the face of climate change. the degree to which landscapes are connected determines the overall amount of movement taking place within and between local populations. this connectivity has influences on gene flow, local adaptation, extinction risk, colonization probability, and the potential for organisms to move and adapt to climate change. with habitat loss and fragmentation increasingly deteriorating natural habitats, the sizes and isolation of the remaining habitat fragments are particularly critical to the long - term conservation of biodiversity. thus, connectivity among these remaining fragments, as well as the characteristics of the surrounding matrix, and the permeability and structure of the habitat edges are all important for biodiversity conservation and affect the overall persistence, strength and integrity of the remaining ecological interactions. = = quantifying landscape connectivity = = since the definition of landscape connectivity has both a physical and a behavioural component, quantifying landscape connectivity is consequently organism -, process - and landscape - specific. according to ( wiens & milne, 1989 ), the first step in the quantification process of landscape connectivity is defining the specific habitat or habitat network of the focal species, and in turn, describe the landscape elements from its point of view. the next step is to determine the scale of the landscape structure as perceived by the organism. this is defined as the scale at which the species responds to the array of landscape elements, through its fine - scale ( grain ), and large - scale ( extent ), movement behaviours. lastly, how the species responds to the different elements of a landscape is determined. this comprises the species'movement pattern based on behavioural reactions to the mortality risk of the landscape elements, including habitat barriers and edges. landscape networks can be constructed based on the linear relationship between a species home range size and its dispersal distance. for example, small mammals will have a small range and short dispersal distances and large ones will have larger range and long dispersal distances. in short this relationship can help in scaling & constructing landscape networks based on a mammals body size. for many organisms, particularly marine invertebrates, the
Answer:
|
habitat change
| null |
A consequence of creating thousands of notebooks is
0. longer days
1. habitat change
2. lush landscapes
3. shorter days.
decision on the situation. once the situation has been assessed, the contractor makes the appropriate accommodations to not disturb the species. vegetation : there may be particular trees or other vegetation that must be protected on the job site. this may require fences or security tape to warn builders that they must not be harmed. wetlands : the contractor must make accommodations so that erosion and water flow are not affected by construction. any liquid spills must be maintained due to contaminants that may enter the wetland. historical or cultural artifacts : artifacts may include arrowheads, pottery shards, and bones. all work comes to a halt if any artifacts are found and will not resume until they can be properly examined and removed from the area. = = construction activity documentation = = project meetings take place at scheduled intervals to discuss the progress on the construction site and any concerns or issues. the discussion and any decisions made at the meeting must be documented. diaries, logs, and daily field reports keep track of the daily activities on a job site each day. diaries : each member of the project team is expected to keep a project diary. the diary contains summaries of the day's events in the member's own words. they are used to keep track of any daily work activity, conversations, observations, or any other relevant information regarding the construction activities. diaries can be referred to when disputes arise and a diary happens to contain information connected with the disagreement. diaries that are handwritten can be used as evidence in court. logs : logs keep track of the regular activities on the job site such as phone logs, transmittal logs, delivery logs, and request for information ( rfi ) logs. daily field reports : daily field reports are a more formal way of recording information on the job site. they contain information that includes the day's activities, temperature and weather conditions, delivered equipment or materials, visitors on the site, images of the job site and equipment used that day. labor statements are required on a daily basis. also list of labor, pert cpm are needed for labor planning to complete a project in time. = = resolving disputes = = mediation : mediation uses a third party mediator to resolve any disputes. the mediator helps both disputing parties to come to a mutual agreement. this cost - saving process ensures that no attorneys become involved in the dispute and is less time - consuming. minitrial : a minitrial takes more time and money than a mediation. the minitrial takes place in an informal setting and involves some type of advisor or
to changes in dispersal or movement of species including changes to seasonal migration. these changes can lead to a decrease in a density of species, increased competition or even increased predation. = = implications = = = = = habitat and biodiversity loss = = = one of the major ways that habitat fragmentation affects biodiversity is by reducing the amount of suitable habitat available for organisms. habitat fragmentation often involves both habitat destruction and the subdivision of previously continuous habitat. plants and other sessile organisms are disproportionately affected by some types of habitat fragmentation because they cannot respond quickly to the altered spatial configuration of the habitat. habitat fragmentation consistently reduces biodiversity by 13 to 75 % and impairs key ecosystem functions by decreasing biomass and altering nutrient cycles. this underscores the severe and lasting ecological impacts of fragmentation, which could be highlighted in the sections discussing the consequences of fragmentation. habitat loss, which can occur through the process of habitat fragmentation, is considered to be the greatest threat to species. but, the effect of the configuration of habitat patches within the landscape, independent of the effect of the amount of habitat within the landscape ( referred to as fragmentation per se ), has been suggested to be small. a review of empirical studies found that, of the 381 reported significant effect of habitat fragmentation per se on species occurrences, abundances or diversity in the scientific literature, 76 % were positive whereas 24 % were negative. despite these results, the scientific literature tends to emphasize negative effects more than positive effects. positive effects of habitat fragmentation per se imply that several small patches of habitat can have higher conservation value than a single large patch of equivalent size. land sharing strategies could therefore have more positive impacts on species than land sparing strategies. although the negative effects of habitat loss are generally viewed to be much larger than that of habitat fragmentation, the two events are heavily connected and observations are not usually independent of one another. area is the primary determinant of the number of species in a fragment and the relative contributions of demographic and genetic processes to the risk of global population extinction depend on habitat configuration, stochastic environmental variation and species features. minor fluctuations in climate, resources, or other factors that would be unremarkable and quickly corrected in large populations can be catastrophic in small, isolated populations. thus fragmentation of habitat is an important cause of species extinction. population dynamics of subdivided populations tend to vary asynchronously. in an unfragmented landscape a declining population can be " rescued " by immigration from a nearby expanding population. in fragmented landscapes, the distance between fragments
biodiversity is being destroyed at a rate unprecedented in human history ". the report claims that 68 % of the population of the examined species were destroyed in the years 1970 β 2016. of 70, 000 monitored species, around 48 % are experiencing population declines from human activity ( in 2023 ), whereas only 3 % have increasing populations. rates of decline in biodiversity in the current sixth mass extinction match or exceed rates of loss in the five previous mass extinction events in the fossil record. biodiversity loss is in fact " one of the most critical manifestations of the anthropocene " ( since around the 1950s ) ; the continued decline of biodiversity constitutes " an unprecedented threat " to the continued existence of human civilization. the reduction is caused primarily by human impacts, particularly habitat destruction. since the stone age, species loss has accelerated above the average basal rate, driven by human activity. estimates of species losses are at a rate 100 β 10, 000 times as fast as is typical in the fossil record. loss of biodiversity results in the loss of natural capital that supplies ecosystem goods and services. species today are being wiped out at a rate 100 to 1, 000 times higher than baseline, and the rate of extinctions is increasing. this process destroys the resilience and adaptability of life on earth. in 2006, many species were formally classified as rare or endangered or threatened ; moreover, scientists have estimated that millions more species are at risk which have not been formally recognized. about 40 percent of the 40, 177 species assessed using the iucn red list criteria are now listed as threatened with extinction β a total of 16, 119. as of late 2022 9251 species were considered part of the iucn's critically endangered. numerous scientists and the ipbes global assessment report on biodiversity and ecosystem services assert that human population growth and overconsumption are the primary factors in this decline. however, other scientists have criticized this finding and say that loss of habitat caused by " the growth of commodities for export " is the main driver. a 2025 study found that human activities are responsible for biodiversity loss across all species and ecosystems. some studies have however pointed out that habitat destruction for the expansion of agriculture and the overexploitation of wildlife are the more significant drivers of contemporary biodiversity loss, not climate change. = = distribution = = biodiversity is not evenly distributed, rather it varies greatly across the globe as well as within regions and seasons. among other factors, the diversity of all living things ( biota ) depends on temperature, precipitation, altitude, soils, geography and the
cause of species extinction. population dynamics of subdivided populations tend to vary asynchronously. in an unfragmented landscape a declining population can be " rescued " by immigration from a nearby expanding population. in fragmented landscapes, the distance between fragments may prevent this from happening. additionally, unoccupied fragments of habitat that are separated from a source of immigrants by some barrier are less likely to be repopulated than adjoining fragments. even small species such as the columbia spotted frog are reliant on the rescue effect. studies showed 25 % of juveniles travel a distance over 200m compared to 4 % of adults. of these, 95 % remain in their new locale, demonstrating that this journey is necessary for survival. additionally, habitat fragmentation leads to edge effects. microclimatic changes in light, temperature, and wind can alter the ecology around the fragment, and in the interior and exterior portions of the fragment. fires become more likely in the area as humidity drops and temperature and wind levels rise. exotic and pest species may establish themselves easily in such disturbed environments, and the proximity of domestic animals often upsets the natural ecology. also, habitat along the edge of a fragment has a different climate and favours different species from the interior habitat. small fragments are therefore unfavourable for species that require interior habitat. the percentage preservation of contiguous habitats is closely related to both genetic and species biodiversity preservation. generally a 10 % remnant contiguous habitat will result in a 50 % biodiversity loss. much of the remaining terrestrial wildlife habitat in many third world countries has experienced fragmentation through the development of urban expansion such as roads interfering with habitat loss. aquatic species β habitats have been fragmented by dams and water diversions. these fragments of habitat may not be large or connected enough to support species that need a large territory where they can find mates and food. the loss and fragmentation of habitats makes it difficult for migratory species to find places to rest and feed along their migration routes. the effects of current fragmentation will continue to emerge for decades. extinction debts are likely to come due, although the counteracting immigration debts may never fully be paid. indeed, the experiments here reveal ongoing losses of biodiversity and ecosystem functioning two decades or longer after fragmentation occurred. understanding the relationship between transient and long - term dynamics is a substantial challenge that ecologists must tackle, and fragmentation experiments will be central for relating observation to theory. = = = informed conservation = = = habitat fragmentation is often a cause of species becoming threatened or endangered. the existence of viable habitat is critical to the survival of
development, and climate change can impact the quality and distribution of habitats and necessitate the movement of species to new locations of suitable habitat. = = = incidental movement = = = movement of species in areas that are typically used by humans. these include greenbelts, recreational trail systems, hedgerows, and golf courses. = = connectivity conservation = = preserving or creating landscape connectivity has become increasingly recognized as a key strategy to protect biodiversity, maintain viable ecosystems and wildlife populations, and facilitate the movement and adaptation of wildlife populations in the face of climate change. the degree to which landscapes are connected determines the overall amount of movement taking place within and between local populations. this connectivity has influences on gene flow, local adaptation, extinction risk, colonization probability, and the potential for organisms to move and adapt to climate change. with habitat loss and fragmentation increasingly deteriorating natural habitats, the sizes and isolation of the remaining habitat fragments are particularly critical to the long - term conservation of biodiversity. thus, connectivity among these remaining fragments, as well as the characteristics of the surrounding matrix, and the permeability and structure of the habitat edges are all important for biodiversity conservation and affect the overall persistence, strength and integrity of the remaining ecological interactions. = = quantifying landscape connectivity = = since the definition of landscape connectivity has both a physical and a behavioural component, quantifying landscape connectivity is consequently organism -, process - and landscape - specific. according to ( wiens & milne, 1989 ), the first step in the quantification process of landscape connectivity is defining the specific habitat or habitat network of the focal species, and in turn, describe the landscape elements from its point of view. the next step is to determine the scale of the landscape structure as perceived by the organism. this is defined as the scale at which the species responds to the array of landscape elements, through its fine - scale ( grain ), and large - scale ( extent ), movement behaviours. lastly, how the species responds to the different elements of a landscape is determined. this comprises the species'movement pattern based on behavioural reactions to the mortality risk of the landscape elements, including habitat barriers and edges. landscape networks can be constructed based on the linear relationship between a species home range size and its dispersal distance. for example, small mammals will have a small range and short dispersal distances and large ones will have larger range and long dispersal distances. in short this relationship can help in scaling & constructing landscape networks based on a mammals body size. for many organisms, particularly marine invertebrates, the
Answer:
|
lush landscapes
| 0.3 |
Which is a cause of greenhouse gases?
0. elephants
1. pears
2. boulders
3. oaks
clouds ( β25 % ) are the biggest contributors to the greenhouse effect, they primarily change as a function of temperature and are therefore mostly considered to be feedbacks that change climate sensitivity. on the other hand, concentrations of gases such as co2 ( β20 % ), tropospheric ozone, cfcs and nitrous oxide are added or removed independently from temperature, and are therefore considered to be external forcings that change global temperatures. before the industrial revolution, naturally - occurring amounts of greenhouse gases caused the air near the surface to be about 33 Β°c warmer than it would have been in their absence. human activity since the industrial revolution, mainly extracting and burning fossil fuels ( coal, oil, and natural gas ), has increased the amount of greenhouse gases in the atmosphere. in 2022, the concentrations of co2 and methane had increased by about 50 % and 164 %, respectively, since 1750. these co2 levels are higher than they have been at any time during the last 14 million years. concentrations of methane are far higher than they were over the last 800, 000 years. global human - caused greenhouse gas emissions in 2019 were equivalent to 59 billion tonnes of co2. of these emissions, 75 % was co2, 18 % was methane, 4 % was nitrous oxide, and 2 % was fluorinated gases. co2 emissions primarily come from burning fossil fuels to provide energy for transport, manufacturing, heating, and electricity. additional co2 emissions come from deforestation and industrial processes, which include the co2 released by the chemical reactions for making cement, steel, aluminum, and fertilizer. methane emissions come from livestock, manure, rice cultivation, landfills, wastewater, and coal mining, as well as oil and gas extraction. nitrous oxide emissions largely come from the microbial decomposition of fertilizer. while methane only lasts in the atmosphere for an average of 12 years, co2 lasts much longer. the earth's surface absorbs co2 as part of the carbon cycle. while plants on land and in the ocean absorb most excess emissions of co2 every year, that co2 is returned to the atmosphere when biological matter is digested, burns, or decays. land - surface carbon sink processes, such as carbon fixation in the soil and photosynthesis, remove about 29 % of annual global co2 emissions. the ocean has absorbed 20 to 30 % of emitted co2 over the last two decades. co2 is only removed from the atmosphere for the long term
. green plumbers, green purchasing etc., sometimes used as a noun e. g. the greens. greenhouse effect - the insulating effect of atmospheric greenhouse gases ( e. g., water vapor, carbon dioxide, methane, etc. ) that keeps the earth's temperature about 60 Β°f ( 16 Β°c ) warmer than it would be otherwise cf. enhanced greenhouse effect. greenhouse gases - any gas that contributes to the greenhouse effect ; gaseous constituents of the atmosphere, both natural and from human activity, that absorb and re - emit infrared radiation. water vapor ( h2o ) is the most abundant greenhouse gas. greenhouse gases are a natural part of the atmosphere and include carbon dioxide ( co2 ), methane ( ch4, persisting 9 - 15 yrs with a greenhouse warming potential ( gwp ) 22 times that of co2 ), nitrous oxide ( n2o persists 120 years and has a gwp of 310 ), ozone ( o3 ), hydrofluorocarbons, perfluorocarbons and sulfur hexafluoride. greenlash β dramatic changes in the structure and dynamic behaviour of ecosystems. greenwashing - companies that portray themselves as environmentally friendly when their business practices do not back this up. generally applies to excessive use of green marketing and packaging when this does not take account of the total ecological footprint. greenwater β water replenishing soil moisture, evaporating from soil, plant and other surfaces, and transpired by plants. in nature the global average amount of rainfall becoming green water is about 60 %. of the green water about 55 % falls on forests, 25 % on grasslands and about 20 % on crops. we can increase green water productivity by rainwater harvesting, increased infiltration and runoff collection. green water cannot be piped or drunk ( cannot be sold ) and is therefore generally ignored by water management authorities but it is crucial to plants in both nature and agriculture and needs careful management as an important part of the global water cycle. greywater β household waste water that has not come into contact with toilet waste ; includes water from baths, showers, bathrooms, washing machines, laundry and kitchen sinks. gross primary productivity - total carbon assimilation. groundwater β water found below the surface β usually in porous rocks, or soil, or in underground aquifers. growth β increase in size, weight, power etc. = = h = = habitat - an ecological or environmental area that is inhabited by a particular species. hard waste - household garbage which
greenhouse gases and increases temperatures. because both water vapor and volcanic material have low persistence in the atmosphere, even the largest eruptions only have an effect for several years. = = see also = = climate change adaptation climate change denial climate change mitigation climate resilience = = references = = = = = sources = = = albrecht, bruce a. ( 1989 ). " aerosols, cloud microphysics, and fractional cloudiness ". science. 245 ( 4923 ) : 1227 β 1239. bibcode : 1989sci... 245. 1227a. doi : 10. 1126 / science. 245. 4923. 1227. pmid 17747885. s2cid 46152332. davidson, eric ( 2009 ). " the contribution of manure and fertilizer nitrogen to atmospheric nitrous oxide since 1860 ". nature geoscience. 2 : 659 β 662. doi : 10. 1016 / j. chemer. 2016. 04. 002. dean, joshua f. ; middelburg, jack j. ; rockmann, thomas ; aerts, rien ; et al. ( 2018 ). " methane feedbacks to the global climate system in a warmer world ". reviews of geophysics. 56 ( 1 ) : 207 β 250. bibcode : 2018rvgeo.. 56.. 207d. doi : 10. 1002 / 2017rg000559. hdl : 2066 / 195183. issn 1944 - 9208. us epa ( 13 september 2019 ). " global greenhouse gas emissions data ". archived from the original on 18 february 2020. retrieved 8 august 2020. us epa ( 15 september 2020 ). " overview of greenhouse gases ". retrieved 15 september 2020. he, yanyi ; wang, kaicun ; zhou, chunlue ; wild, martin ( 2018 ). " a revisit of global dimming and brightening based on the sunshine duration ". geophysical research letters. 45 ( 9 ) : 4281 β 4289. bibcode : 2018georl.. 45. 4281h. doi : 10. 1029 / 2018gl077424. hdl : 20. 500. 11850 / 268470. issn 1944 - 8007. knutson, t. ; kossin, j. p. ; mears, c. ; perlwitz, j. ;
as heat, and greenhouse gases absorb a portion of it. this absorption slows the rate at which heat escapes into space, trapping heat near the earth's surface and warming it over time. while water vapour and clouds are the biggest contributors to the greenhouse effect, they primarily change as a function of temperature. therefore, they are considered to be feedbacks that change climate sensitivity. on the other hand, gases such as co2, tropospheric ozone, cfcs and nitrous oxide are added or removed independently from temperature. hence, they are considered to be external forcings that change global temperatures. : 742 human activity since the industrial revolution ( about 1750 ), mainly extracting and burning fossil fuels ( coal, oil, and natural gas ), has increased the amount of greenhouse gases in the atmosphere, resulting in a radiative imbalance. over the past 150 years human activities have released increasing quantities of greenhouse gases into the atmosphere. by 2019, the concentrations of co2 and methane had increased by about 48 % and 160 %, respectively, since 1750. these co2 levels are higher than they have been at any time during the last 2 million years. concentrations of methane are far higher than they were over the last 800, 000 years. this has led to increases in mean global temperature, or global warming. the likely range of human - induced surface - level air warming by 2010 β 2019 compared to levels in 1850 β 1900 is 0. 8 Β°c to 1. 3 Β°c, with a best estimate of 1. 07 Β°c. this is close to the observed overall warming during that time of 0. 9 Β°c to 1. 2 Β°c. temperature changes during that time were likely only Β±0. 1 Β°c due to natural forcings and Β±0. 2 Β°c due to variability in the climate. : 3, 443 global anthropogenic greenhouse gas emissions in 2019 were equivalent to 59 billion tonnes of co2. of these emissions, 75 % was co2, 18 % was methane, 4 % was nitrous oxide, and 2 % was fluorinated gases. : 7 = = = = carbon dioxide = = = = co2 emissions primarily come from burning fossil fuels to provide energy for transport, manufacturing, heating, and electricity. additional co2 emissions come from deforestation and industrial processes, which include the co2 released by the chemical reactions for making cement, steel, aluminum, and fertiliser. co2 is absorbed and emitted naturally as part of the carbon cycle, through animal and plant
the scientific community has been investigating the causes of climate change for decades. after thousands of studies, the scientific consensus is that it is " unequivocal that human influence has warmed the atmosphere, ocean and land since pre - industrial times. " : 3 this consensus is supported by around 200 scientific organizations worldwide. the scientific principle underlying current climate change is the greenhouse effect, which provides that greenhouse gases pass sunlight that heats the earth, but trap some of the resulting heat that radiates from the planet's surface. large amounts of greenhouse gases such as carbon dioxide and methane have been released into the atmosphere through burning of fossil fuels since the industrial revolution. indirect emissions from land use change, emissions of other greenhouse gases such as nitrous oxide, and increased concentrations of water vapor in the atmosphere, also contribute to climate change. the warming from the greenhouse effect has a logarithmic relationship with the concentration of greenhouse gases. this means that every additional fraction of co2 and the other greenhouse gases in the atmosphere has a slightly smaller warming effect than the fractions before it as the total concentration increases. however, only around half of co2 emissions continually reside in the atmosphere in the first place, as the other half is quickly absorbed by carbon sinks in the land and oceans. : 450 further, the warming per unit of greenhouse gases is also affected by feedbacks, such as the changes in water vapor concentrations or earth's albedo ( reflectivity ). : 2233 as the warming from co2 increases, carbon sinks absorb a smaller fraction of total emissions, while the " fast " climate change feedbacks amplify greenhouse gas warming. thus, the effects counteract one another, and the warming from each unit of co2 emitted by humans increases temperature in linear proportion to the total amount of emissions. : 746 further, some fraction of the greenhouse warming has been " masked " by the human - caused emissions of sulfur dioxide, which forms aerosols that have a cooling effect. however, this masking has been receding in the recent years, due to measures to combat acid rain and air pollution caused by sulfates. = = factors affecting earth's climate = = a forcing is something that is imposed externally on the climate system. external forcings include natural phenomena such as volcanic eruptions and variations in the sun's output. human activities can also impose forcings, for example, through changing the composition of earth's atmosphere. radiative forcing is a measure of how various factors alter the energy balance of planet earth.
Answer:
|
elephants
| null |
Which is a cause of greenhouse gases?
0. elephants
1. pears
2. boulders
3. oaks
clouds ( β25 % ) are the biggest contributors to the greenhouse effect, they primarily change as a function of temperature and are therefore mostly considered to be feedbacks that change climate sensitivity. on the other hand, concentrations of gases such as co2 ( β20 % ), tropospheric ozone, cfcs and nitrous oxide are added or removed independently from temperature, and are therefore considered to be external forcings that change global temperatures. before the industrial revolution, naturally - occurring amounts of greenhouse gases caused the air near the surface to be about 33 Β°c warmer than it would have been in their absence. human activity since the industrial revolution, mainly extracting and burning fossil fuels ( coal, oil, and natural gas ), has increased the amount of greenhouse gases in the atmosphere. in 2022, the concentrations of co2 and methane had increased by about 50 % and 164 %, respectively, since 1750. these co2 levels are higher than they have been at any time during the last 14 million years. concentrations of methane are far higher than they were over the last 800, 000 years. global human - caused greenhouse gas emissions in 2019 were equivalent to 59 billion tonnes of co2. of these emissions, 75 % was co2, 18 % was methane, 4 % was nitrous oxide, and 2 % was fluorinated gases. co2 emissions primarily come from burning fossil fuels to provide energy for transport, manufacturing, heating, and electricity. additional co2 emissions come from deforestation and industrial processes, which include the co2 released by the chemical reactions for making cement, steel, aluminum, and fertilizer. methane emissions come from livestock, manure, rice cultivation, landfills, wastewater, and coal mining, as well as oil and gas extraction. nitrous oxide emissions largely come from the microbial decomposition of fertilizer. while methane only lasts in the atmosphere for an average of 12 years, co2 lasts much longer. the earth's surface absorbs co2 as part of the carbon cycle. while plants on land and in the ocean absorb most excess emissions of co2 every year, that co2 is returned to the atmosphere when biological matter is digested, burns, or decays. land - surface carbon sink processes, such as carbon fixation in the soil and photosynthesis, remove about 29 % of annual global co2 emissions. the ocean has absorbed 20 to 30 % of emitted co2 over the last two decades. co2 is only removed from the atmosphere for the long term
. green plumbers, green purchasing etc., sometimes used as a noun e. g. the greens. greenhouse effect - the insulating effect of atmospheric greenhouse gases ( e. g., water vapor, carbon dioxide, methane, etc. ) that keeps the earth's temperature about 60 Β°f ( 16 Β°c ) warmer than it would be otherwise cf. enhanced greenhouse effect. greenhouse gases - any gas that contributes to the greenhouse effect ; gaseous constituents of the atmosphere, both natural and from human activity, that absorb and re - emit infrared radiation. water vapor ( h2o ) is the most abundant greenhouse gas. greenhouse gases are a natural part of the atmosphere and include carbon dioxide ( co2 ), methane ( ch4, persisting 9 - 15 yrs with a greenhouse warming potential ( gwp ) 22 times that of co2 ), nitrous oxide ( n2o persists 120 years and has a gwp of 310 ), ozone ( o3 ), hydrofluorocarbons, perfluorocarbons and sulfur hexafluoride. greenlash β dramatic changes in the structure and dynamic behaviour of ecosystems. greenwashing - companies that portray themselves as environmentally friendly when their business practices do not back this up. generally applies to excessive use of green marketing and packaging when this does not take account of the total ecological footprint. greenwater β water replenishing soil moisture, evaporating from soil, plant and other surfaces, and transpired by plants. in nature the global average amount of rainfall becoming green water is about 60 %. of the green water about 55 % falls on forests, 25 % on grasslands and about 20 % on crops. we can increase green water productivity by rainwater harvesting, increased infiltration and runoff collection. green water cannot be piped or drunk ( cannot be sold ) and is therefore generally ignored by water management authorities but it is crucial to plants in both nature and agriculture and needs careful management as an important part of the global water cycle. greywater β household waste water that has not come into contact with toilet waste ; includes water from baths, showers, bathrooms, washing machines, laundry and kitchen sinks. gross primary productivity - total carbon assimilation. groundwater β water found below the surface β usually in porous rocks, or soil, or in underground aquifers. growth β increase in size, weight, power etc. = = h = = habitat - an ecological or environmental area that is inhabited by a particular species. hard waste - household garbage which
greenhouse gases and increases temperatures. because both water vapor and volcanic material have low persistence in the atmosphere, even the largest eruptions only have an effect for several years. = = see also = = climate change adaptation climate change denial climate change mitigation climate resilience = = references = = = = = sources = = = albrecht, bruce a. ( 1989 ). " aerosols, cloud microphysics, and fractional cloudiness ". science. 245 ( 4923 ) : 1227 β 1239. bibcode : 1989sci... 245. 1227a. doi : 10. 1126 / science. 245. 4923. 1227. pmid 17747885. s2cid 46152332. davidson, eric ( 2009 ). " the contribution of manure and fertilizer nitrogen to atmospheric nitrous oxide since 1860 ". nature geoscience. 2 : 659 β 662. doi : 10. 1016 / j. chemer. 2016. 04. 002. dean, joshua f. ; middelburg, jack j. ; rockmann, thomas ; aerts, rien ; et al. ( 2018 ). " methane feedbacks to the global climate system in a warmer world ". reviews of geophysics. 56 ( 1 ) : 207 β 250. bibcode : 2018rvgeo.. 56.. 207d. doi : 10. 1002 / 2017rg000559. hdl : 2066 / 195183. issn 1944 - 9208. us epa ( 13 september 2019 ). " global greenhouse gas emissions data ". archived from the original on 18 february 2020. retrieved 8 august 2020. us epa ( 15 september 2020 ). " overview of greenhouse gases ". retrieved 15 september 2020. he, yanyi ; wang, kaicun ; zhou, chunlue ; wild, martin ( 2018 ). " a revisit of global dimming and brightening based on the sunshine duration ". geophysical research letters. 45 ( 9 ) : 4281 β 4289. bibcode : 2018georl.. 45. 4281h. doi : 10. 1029 / 2018gl077424. hdl : 20. 500. 11850 / 268470. issn 1944 - 8007. knutson, t. ; kossin, j. p. ; mears, c. ; perlwitz, j. ;
as heat, and greenhouse gases absorb a portion of it. this absorption slows the rate at which heat escapes into space, trapping heat near the earth's surface and warming it over time. while water vapour and clouds are the biggest contributors to the greenhouse effect, they primarily change as a function of temperature. therefore, they are considered to be feedbacks that change climate sensitivity. on the other hand, gases such as co2, tropospheric ozone, cfcs and nitrous oxide are added or removed independently from temperature. hence, they are considered to be external forcings that change global temperatures. : 742 human activity since the industrial revolution ( about 1750 ), mainly extracting and burning fossil fuels ( coal, oil, and natural gas ), has increased the amount of greenhouse gases in the atmosphere, resulting in a radiative imbalance. over the past 150 years human activities have released increasing quantities of greenhouse gases into the atmosphere. by 2019, the concentrations of co2 and methane had increased by about 48 % and 160 %, respectively, since 1750. these co2 levels are higher than they have been at any time during the last 2 million years. concentrations of methane are far higher than they were over the last 800, 000 years. this has led to increases in mean global temperature, or global warming. the likely range of human - induced surface - level air warming by 2010 β 2019 compared to levels in 1850 β 1900 is 0. 8 Β°c to 1. 3 Β°c, with a best estimate of 1. 07 Β°c. this is close to the observed overall warming during that time of 0. 9 Β°c to 1. 2 Β°c. temperature changes during that time were likely only Β±0. 1 Β°c due to natural forcings and Β±0. 2 Β°c due to variability in the climate. : 3, 443 global anthropogenic greenhouse gas emissions in 2019 were equivalent to 59 billion tonnes of co2. of these emissions, 75 % was co2, 18 % was methane, 4 % was nitrous oxide, and 2 % was fluorinated gases. : 7 = = = = carbon dioxide = = = = co2 emissions primarily come from burning fossil fuels to provide energy for transport, manufacturing, heating, and electricity. additional co2 emissions come from deforestation and industrial processes, which include the co2 released by the chemical reactions for making cement, steel, aluminum, and fertiliser. co2 is absorbed and emitted naturally as part of the carbon cycle, through animal and plant
the scientific community has been investigating the causes of climate change for decades. after thousands of studies, the scientific consensus is that it is " unequivocal that human influence has warmed the atmosphere, ocean and land since pre - industrial times. " : 3 this consensus is supported by around 200 scientific organizations worldwide. the scientific principle underlying current climate change is the greenhouse effect, which provides that greenhouse gases pass sunlight that heats the earth, but trap some of the resulting heat that radiates from the planet's surface. large amounts of greenhouse gases such as carbon dioxide and methane have been released into the atmosphere through burning of fossil fuels since the industrial revolution. indirect emissions from land use change, emissions of other greenhouse gases such as nitrous oxide, and increased concentrations of water vapor in the atmosphere, also contribute to climate change. the warming from the greenhouse effect has a logarithmic relationship with the concentration of greenhouse gases. this means that every additional fraction of co2 and the other greenhouse gases in the atmosphere has a slightly smaller warming effect than the fractions before it as the total concentration increases. however, only around half of co2 emissions continually reside in the atmosphere in the first place, as the other half is quickly absorbed by carbon sinks in the land and oceans. : 450 further, the warming per unit of greenhouse gases is also affected by feedbacks, such as the changes in water vapor concentrations or earth's albedo ( reflectivity ). : 2233 as the warming from co2 increases, carbon sinks absorb a smaller fraction of total emissions, while the " fast " climate change feedbacks amplify greenhouse gas warming. thus, the effects counteract one another, and the warming from each unit of co2 emitted by humans increases temperature in linear proportion to the total amount of emissions. : 746 further, some fraction of the greenhouse warming has been " masked " by the human - caused emissions of sulfur dioxide, which forms aerosols that have a cooling effect. however, this masking has been receding in the recent years, due to measures to combat acid rain and air pollution caused by sulfates. = = factors affecting earth's climate = = a forcing is something that is imposed externally on the climate system. external forcings include natural phenomena such as volcanic eruptions and variations in the sun's output. human activities can also impose forcings, for example, through changing the composition of earth's atmosphere. radiative forcing is a measure of how various factors alter the energy balance of planet earth.
Answer:
|
oaks
| 0.3 |
Which of the following actions qualifies as cooking food?
0. setting it in the sun
1. shaking it up and down
2. putting it in the freezer
3. running it under water
and simmering are popular cooking methods that often require immersing food in water or its gaseous state, steam. water is also used for dishwashing. water also plays many critical roles within the field of food science. solutes such as salts and sugars found in water affect the physical properties of water. the boiling and freezing points of water are affected by solutes, as well as air pressure, which is in turn affected by altitude. water boils at lower temperatures with the lower air pressure that occurs at higher elevations. one mole of sucrose ( sugar ) per kilogram of water raises the boiling point of water by 0. 51 Β°c ( 0. 918 Β°f ), and one mole of salt per kg raises the boiling point by 1. 02 Β°c ( 1. 836 Β°f ) ; similarly, increasing the number of dissolved particles lowers water's freezing point. solutes in water also affect water activity that affects many chemical reactions and the growth of microbes in food. water activity can be described as a ratio of the vapor pressure of water in a solution to the vapor pressure of pure water. solutes in water lower water activity β this is important to know because most bacterial growth ceases at low levels of water activity. not only does microbial growth affect the safety of food, but also the preservation and shelf life of food. water hardness is also a critical factor in food processing and may be altered or treated by using a chemical ion exchange system. it can dramatically affect the quality of a product, as well as playing a role in sanitation. water hardness is classified based on concentration of calcium carbonate the water contains. water is classified as soft if it contains less than 100 mg / l ( uk ) or less than 60 mg / l ( us ). according to a report published by the water footprint organization in 2010, a single kilogram of beef requires 15 thousand litres ( 3. 3Γ10 ^ 3 imp gal ; 4. 0Γ10 ^ 3 us gal ) of water ; however, the authors also make clear that this is a global average and circumstantial factors determine the amount of water used in beef production. = = = = medical use = = = = water for injection is on the world health organization's list of essential medicines. = = distribution in nature = = = = = in the universe = = = much of the universe's water is produced as a byproduct of star formation. the formation of stars is accompanied by a strong outward
conditions, reduce energy consumption, and improve city services. = = = heating, cooling and cooking = = = heating, cooling and cooking are also targets for improved energy efficiency and reduction of carbon emissions. increasingly following europe and asia, north americans are switching from gas or electrical resistance stoves to induction cooking. consumers are also switching heating systems from coal, fuel oil, or natural gas to electricity - driven steam or hot water ; and to air - source or ground - source heat pumps for both heating and cooling. = = = food = = = food production tends to be heavily dependent on fossil fuels, in the production of nitrogen fertilizer and to power agricultural machinery used in the planting, tending and harvesting of crops. the movement of food from producers to consumers also tends to involve major fossil - fuel costs, since many crops are grown far from their potential market and have a short shelf life. many countries depend on international markets to obtain critical food supplies. food production and supply chains are being increasingly destabilized by the effects of climate change on agriculture, the covid - 19 pandemic, and the russian invasion of ukraine. in the united states, at the same time that millions of americans experience food insecurity, as much as 40 percent of food is wasted. at the consumer level, steps towards achieving net zero include eating more local and plant - based foods, minimizing food waste, and composting remaining plant - based wastes. consumers and investors may also choose to support companies based on their carbon footprint and transparency. in terms of city infrastructure, initiatives to identify and redirect usable food ( " food rescue " ), to separate waste streams, and to improve handling of food waste are all important. in low - income countries, small - scale and household - level biogas systems are being used to convert wastes into energy. composting and anaerobic digestion ( ad ) are increasingly being used in countries at all income levels. farmers and farming communities need scientific, technical, and financial support to move to more climate - friendly farming practices and to support initiatives for climate change adaptation, regenerative agriculture and biosequestration. collaboration between stakeholders at all levels of the private, public and civil sectors is needed to improve food sector infrastructure. = = = construction = = = the energy efficiency of buildings can be assessed and improved in multiple ways that help to reduce carbon emissions. insulation and energy - efficient windows are commonly used in colder cities. incorporation of features such as solar panels, green roofs and walls
= = = food engineering is the industrial processes used to manufacture food. it involves coming up with novel approaches for manufacturing, packaging, delivering, ensuring quality, ensuring safety, and devising techniques to transform raw ingredients into wholesome food options. = = = food microbiology = = = food microbiology is the study of the microorganisms that inhabit, create, or contaminate food, including the study of microorganisms causing food spoilage. " good " bacteria, however, such as probiotics, are becoming increasingly important in food science. in addition, microorganisms are essential for the production of foods such as cheese, yogurt, bread, beer, wine and, other fermented foods. = = = food technology = = = food technology is the technological aspect. early scientific research into food technology concentrated on food preservation. nicolas appert's development in 1810 of the canning process was a decisive event. the process was not called canning then and appert did not really know the principle on which his process worked, but canning has had a major impact on food preservation techniques. = = = foodomics = = = in 2009, foodomics was defined as " a discipline that studies the food and nutrition domains through the application and integration of advanced - omics technologies to improve consumer's well - being, health, and knowledge ". foodomics requires the combination of food chemistry, biological sciences, and data analysis. foodomics greatly helps scientists in the area of food science and nutrition to gain better access to data, which is used to analyze the effects of food on human health, etc. it is believed to be another step towards a better understanding of the development and application of technology and food. moreover, the study of foodomics leads to other omics sub - disciplines, including nutrigenomics which is the integration of the study of nutrition, genes, and omics. = = = molecular gastronomy = = = molecular gastronomy is a subdiscipline of food science that seeks to investigate the physical and chemical transformations of ingredients that occur in cooking. its program includes three axes, as cooking was recognized to have three components, which are social, artistic, and technical. = = = quality control = = = quality control involves the causes, prevention, and communication dealing with food - borne illness. quality control also ensures that the product meets specs to ensure the customer receives what they expect from the packaging to the physical properties of the product itself. = = = sensory analysis =
food self - provisioning ( fsp ) is the growing of one's own food, especially fruits and vegetables. also labelled as household food production, is a traditional activity persisting in the countries of the global north. it is studied in sustainability science and in ecofeminism on reason of its social, health and environmental outcomes. = = references = =
##rdy, chase ( 2020 ). billion dollar burger : inside big tech's race for the future of food. new york : portfolio. isbn 978 - 0 - 525 - 53694 - 9. rubio, natalie r. ; xiang, ning ; kaplan, david l. ( 2020 ). " plant - based and cell - based approaches to meat production ". nature communications. 11 ( 1 ) : 6276. bibcode : 2020natco.. 11. 6276r. doi : 10. 1038 / s41467 - 020 - 20061 - y. pmc 7722853. pmid 33293564. zimberoff, larissa ( 2021 ). technically food : inside silicon valley β s mission to change what we eat. new york : abrams press. isbn 978 - 1 - 4197 - 4709 - 0. ellies - oury, marie - pierre ; chriki, sghaier ; hocquette, jean - francois ( 2022 ). " chapter six - should and will " cultured meat " become a reality in our plates? ". advances in food and nutrition research. 101 : 181 β 212. doi : 10. 1016 / bs. afnr. 2022. 04. 005. pmid 35940705. ching, xin li ; zainal, nur anis athira binti ; luang - in, vijitra ; ma, nyuk ling ( 2022 ). " lab - based meat the future food ". environmental advances. 10 : 100315. bibcode : 2022envad.. 1000315c. doi : 10. 1016 / j. envadv. 2022. 100315. cultivated meat to secure our future : hope for animals, food security, and the environment. woodstock : lantern publishing & media. 2023. isbn 978 - 1 - 59056 - 697 - 8. jones, nicola ( 4 july 2023 ). " lab - grown meat : the science of turning cells into steaks and nuggets ". nature. 619 ( 7968 ) : 22 β 24. bibcode : 2023natur. 619... 22j. doi : 10. 1038 / d41586 - 023 - 02095 - 6. pmid 37402799. " a conversation about cultivated meat ". nature communications. 14 ( 1 ) :
Answer:
|
setting it in the sun
| null |
Which of the following actions qualifies as cooking food?
0. setting it in the sun
1. shaking it up and down
2. putting it in the freezer
3. running it under water
and simmering are popular cooking methods that often require immersing food in water or its gaseous state, steam. water is also used for dishwashing. water also plays many critical roles within the field of food science. solutes such as salts and sugars found in water affect the physical properties of water. the boiling and freezing points of water are affected by solutes, as well as air pressure, which is in turn affected by altitude. water boils at lower temperatures with the lower air pressure that occurs at higher elevations. one mole of sucrose ( sugar ) per kilogram of water raises the boiling point of water by 0. 51 Β°c ( 0. 918 Β°f ), and one mole of salt per kg raises the boiling point by 1. 02 Β°c ( 1. 836 Β°f ) ; similarly, increasing the number of dissolved particles lowers water's freezing point. solutes in water also affect water activity that affects many chemical reactions and the growth of microbes in food. water activity can be described as a ratio of the vapor pressure of water in a solution to the vapor pressure of pure water. solutes in water lower water activity β this is important to know because most bacterial growth ceases at low levels of water activity. not only does microbial growth affect the safety of food, but also the preservation and shelf life of food. water hardness is also a critical factor in food processing and may be altered or treated by using a chemical ion exchange system. it can dramatically affect the quality of a product, as well as playing a role in sanitation. water hardness is classified based on concentration of calcium carbonate the water contains. water is classified as soft if it contains less than 100 mg / l ( uk ) or less than 60 mg / l ( us ). according to a report published by the water footprint organization in 2010, a single kilogram of beef requires 15 thousand litres ( 3. 3Γ10 ^ 3 imp gal ; 4. 0Γ10 ^ 3 us gal ) of water ; however, the authors also make clear that this is a global average and circumstantial factors determine the amount of water used in beef production. = = = = medical use = = = = water for injection is on the world health organization's list of essential medicines. = = distribution in nature = = = = = in the universe = = = much of the universe's water is produced as a byproduct of star formation. the formation of stars is accompanied by a strong outward
conditions, reduce energy consumption, and improve city services. = = = heating, cooling and cooking = = = heating, cooling and cooking are also targets for improved energy efficiency and reduction of carbon emissions. increasingly following europe and asia, north americans are switching from gas or electrical resistance stoves to induction cooking. consumers are also switching heating systems from coal, fuel oil, or natural gas to electricity - driven steam or hot water ; and to air - source or ground - source heat pumps for both heating and cooling. = = = food = = = food production tends to be heavily dependent on fossil fuels, in the production of nitrogen fertilizer and to power agricultural machinery used in the planting, tending and harvesting of crops. the movement of food from producers to consumers also tends to involve major fossil - fuel costs, since many crops are grown far from their potential market and have a short shelf life. many countries depend on international markets to obtain critical food supplies. food production and supply chains are being increasingly destabilized by the effects of climate change on agriculture, the covid - 19 pandemic, and the russian invasion of ukraine. in the united states, at the same time that millions of americans experience food insecurity, as much as 40 percent of food is wasted. at the consumer level, steps towards achieving net zero include eating more local and plant - based foods, minimizing food waste, and composting remaining plant - based wastes. consumers and investors may also choose to support companies based on their carbon footprint and transparency. in terms of city infrastructure, initiatives to identify and redirect usable food ( " food rescue " ), to separate waste streams, and to improve handling of food waste are all important. in low - income countries, small - scale and household - level biogas systems are being used to convert wastes into energy. composting and anaerobic digestion ( ad ) are increasingly being used in countries at all income levels. farmers and farming communities need scientific, technical, and financial support to move to more climate - friendly farming practices and to support initiatives for climate change adaptation, regenerative agriculture and biosequestration. collaboration between stakeholders at all levels of the private, public and civil sectors is needed to improve food sector infrastructure. = = = construction = = = the energy efficiency of buildings can be assessed and improved in multiple ways that help to reduce carbon emissions. insulation and energy - efficient windows are commonly used in colder cities. incorporation of features such as solar panels, green roofs and walls
= = = food engineering is the industrial processes used to manufacture food. it involves coming up with novel approaches for manufacturing, packaging, delivering, ensuring quality, ensuring safety, and devising techniques to transform raw ingredients into wholesome food options. = = = food microbiology = = = food microbiology is the study of the microorganisms that inhabit, create, or contaminate food, including the study of microorganisms causing food spoilage. " good " bacteria, however, such as probiotics, are becoming increasingly important in food science. in addition, microorganisms are essential for the production of foods such as cheese, yogurt, bread, beer, wine and, other fermented foods. = = = food technology = = = food technology is the technological aspect. early scientific research into food technology concentrated on food preservation. nicolas appert's development in 1810 of the canning process was a decisive event. the process was not called canning then and appert did not really know the principle on which his process worked, but canning has had a major impact on food preservation techniques. = = = foodomics = = = in 2009, foodomics was defined as " a discipline that studies the food and nutrition domains through the application and integration of advanced - omics technologies to improve consumer's well - being, health, and knowledge ". foodomics requires the combination of food chemistry, biological sciences, and data analysis. foodomics greatly helps scientists in the area of food science and nutrition to gain better access to data, which is used to analyze the effects of food on human health, etc. it is believed to be another step towards a better understanding of the development and application of technology and food. moreover, the study of foodomics leads to other omics sub - disciplines, including nutrigenomics which is the integration of the study of nutrition, genes, and omics. = = = molecular gastronomy = = = molecular gastronomy is a subdiscipline of food science that seeks to investigate the physical and chemical transformations of ingredients that occur in cooking. its program includes three axes, as cooking was recognized to have three components, which are social, artistic, and technical. = = = quality control = = = quality control involves the causes, prevention, and communication dealing with food - borne illness. quality control also ensures that the product meets specs to ensure the customer receives what they expect from the packaging to the physical properties of the product itself. = = = sensory analysis =
food self - provisioning ( fsp ) is the growing of one's own food, especially fruits and vegetables. also labelled as household food production, is a traditional activity persisting in the countries of the global north. it is studied in sustainability science and in ecofeminism on reason of its social, health and environmental outcomes. = = references = =
##rdy, chase ( 2020 ). billion dollar burger : inside big tech's race for the future of food. new york : portfolio. isbn 978 - 0 - 525 - 53694 - 9. rubio, natalie r. ; xiang, ning ; kaplan, david l. ( 2020 ). " plant - based and cell - based approaches to meat production ". nature communications. 11 ( 1 ) : 6276. bibcode : 2020natco.. 11. 6276r. doi : 10. 1038 / s41467 - 020 - 20061 - y. pmc 7722853. pmid 33293564. zimberoff, larissa ( 2021 ). technically food : inside silicon valley β s mission to change what we eat. new york : abrams press. isbn 978 - 1 - 4197 - 4709 - 0. ellies - oury, marie - pierre ; chriki, sghaier ; hocquette, jean - francois ( 2022 ). " chapter six - should and will " cultured meat " become a reality in our plates? ". advances in food and nutrition research. 101 : 181 β 212. doi : 10. 1016 / bs. afnr. 2022. 04. 005. pmid 35940705. ching, xin li ; zainal, nur anis athira binti ; luang - in, vijitra ; ma, nyuk ling ( 2022 ). " lab - based meat the future food ". environmental advances. 10 : 100315. bibcode : 2022envad.. 1000315c. doi : 10. 1016 / j. envadv. 2022. 100315. cultivated meat to secure our future : hope for animals, food security, and the environment. woodstock : lantern publishing & media. 2023. isbn 978 - 1 - 59056 - 697 - 8. jones, nicola ( 4 july 2023 ). " lab - grown meat : the science of turning cells into steaks and nuggets ". nature. 619 ( 7968 ) : 22 β 24. bibcode : 2023natur. 619... 22j. doi : 10. 1038 / d41586 - 023 - 02095 - 6. pmid 37402799. " a conversation about cultivated meat ". nature communications. 14 ( 1 ) :
Answer:
|
putting it in the freezer
| 0.3 |
cooking food requires adding what?
0. frozen water
1. scorching power
2. coldness
3. air
conditions, reduce energy consumption, and improve city services. = = = heating, cooling and cooking = = = heating, cooling and cooking are also targets for improved energy efficiency and reduction of carbon emissions. increasingly following europe and asia, north americans are switching from gas or electrical resistance stoves to induction cooking. consumers are also switching heating systems from coal, fuel oil, or natural gas to electricity - driven steam or hot water ; and to air - source or ground - source heat pumps for both heating and cooling. = = = food = = = food production tends to be heavily dependent on fossil fuels, in the production of nitrogen fertilizer and to power agricultural machinery used in the planting, tending and harvesting of crops. the movement of food from producers to consumers also tends to involve major fossil - fuel costs, since many crops are grown far from their potential market and have a short shelf life. many countries depend on international markets to obtain critical food supplies. food production and supply chains are being increasingly destabilized by the effects of climate change on agriculture, the covid - 19 pandemic, and the russian invasion of ukraine. in the united states, at the same time that millions of americans experience food insecurity, as much as 40 percent of food is wasted. at the consumer level, steps towards achieving net zero include eating more local and plant - based foods, minimizing food waste, and composting remaining plant - based wastes. consumers and investors may also choose to support companies based on their carbon footprint and transparency. in terms of city infrastructure, initiatives to identify and redirect usable food ( " food rescue " ), to separate waste streams, and to improve handling of food waste are all important. in low - income countries, small - scale and household - level biogas systems are being used to convert wastes into energy. composting and anaerobic digestion ( ad ) are increasingly being used in countries at all income levels. farmers and farming communities need scientific, technical, and financial support to move to more climate - friendly farming practices and to support initiatives for climate change adaptation, regenerative agriculture and biosequestration. collaboration between stakeholders at all levels of the private, public and civil sectors is needed to improve food sector infrastructure. = = = construction = = = the energy efficiency of buildings can be assessed and improved in multiple ways that help to reduce carbon emissions. insulation and energy - efficient windows are commonly used in colder cities. incorporation of features such as solar panels, green roofs and walls
and sensory properties. however, ohmic heating is limited by viscosity, electrical conductivity, and fouling deposits. although ohmic heating has not yet been approved by the food and drug administration ( fda ) for commercial use, this method has many potential applications, ranging from cooking to fermentation. there are different configurations for continuous ohmic heating systems, but in the most basic process, a power supply or generator is needed to produce electrical current. electrodes, in direct contact with food, pass electric current through the matrix. the distance between the electrodes can be adjusted to achieve the optimum electrical field strength. the generator creates the electrical current which flows to the first electrode and passes through the food product placed in the electrode gap. the food product resists the flow of current causing internal heating. the current continues to flow to the second electrode and back to the power source to close the circuit. the insulator caps around the electrodes controls the environment within the system. the electrical field strength and the residence time are the key process parameters which affect heat generation. the ideal foods for ohmic heating are viscous with particulates. thick soups sauces stews salsa fruit in a syrup medium milk ice cream mix egg whey heat sensitive liquids soymilk the efficiency by which electricity is converted to heat depends upon on salt, water, and fat content due to their thermal conductivity and resistance factors. in particulate foods, the particles heat up faster than the liquid matrix due to higher resistance to electricity and matching conductivity can contribute to uniform heating. this prevents overheating of the liquid matrix while particles receive sufficient heat processing. table 1 shows the electrical conductivity values of certain foods to display the effect of composition and salt concentration. the high electrical conductivity values represent a larger number of ionic compounds suspended in the product, which is directly proportional to the rate of heating. this value is increased in the presence of polar compounds, like acids and salts, but decreased with nonpolar compounds, like fats. electrical conductivity of food materials generally increases with temperature, and can change if there are structural changes caused during heating such as gelatinization of starch. density, ph, and specific heat of various components in a food matrix can also influence heating rate. benefits of ohmic heating include : uniform and rapid heating ( > 1Β°csβ1 ), less cooking time, better energy efficiency, lower capital cost, and heating simulataneously throughout food's volume as compared to aseptic processing, canning,
and simmering are popular cooking methods that often require immersing food in water or its gaseous state, steam. water is also used for dishwashing. water also plays many critical roles within the field of food science. solutes such as salts and sugars found in water affect the physical properties of water. the boiling and freezing points of water are affected by solutes, as well as air pressure, which is in turn affected by altitude. water boils at lower temperatures with the lower air pressure that occurs at higher elevations. one mole of sucrose ( sugar ) per kilogram of water raises the boiling point of water by 0. 51 Β°c ( 0. 918 Β°f ), and one mole of salt per kg raises the boiling point by 1. 02 Β°c ( 1. 836 Β°f ) ; similarly, increasing the number of dissolved particles lowers water's freezing point. solutes in water also affect water activity that affects many chemical reactions and the growth of microbes in food. water activity can be described as a ratio of the vapor pressure of water in a solution to the vapor pressure of pure water. solutes in water lower water activity β this is important to know because most bacterial growth ceases at low levels of water activity. not only does microbial growth affect the safety of food, but also the preservation and shelf life of food. water hardness is also a critical factor in food processing and may be altered or treated by using a chemical ion exchange system. it can dramatically affect the quality of a product, as well as playing a role in sanitation. water hardness is classified based on concentration of calcium carbonate the water contains. water is classified as soft if it contains less than 100 mg / l ( uk ) or less than 60 mg / l ( us ). according to a report published by the water footprint organization in 2010, a single kilogram of beef requires 15 thousand litres ( 3. 3Γ10 ^ 3 imp gal ; 4. 0Γ10 ^ 3 us gal ) of water ; however, the authors also make clear that this is a global average and circumstantial factors determine the amount of water used in beef production. = = = = medical use = = = = water for injection is on the world health organization's list of essential medicines. = = distribution in nature = = = = = in the universe = = = much of the universe's water is produced as a byproduct of star formation. the formation of stars is accompanied by a strong outward
ohmic heating include : uniform and rapid heating ( > 1Β°csβ1 ), less cooking time, better energy efficiency, lower capital cost, and heating simulataneously throughout food's volume as compared to aseptic processing, canning, and pef. volumetric heating allows internal heating instead of transferring heat from a secondary medium. this results in the production of safe, high quality food with minimal changes to structural, nutritional, and organoleptic properties of food. heat transfer is uniform to reach areas of food that are harder to heat. less fouling accumulates on the electrodes as compared to other heating methods. ohmic heating also requires less cleaning and maintenance, resulting in an environmentally cautious heating method. microbial inactivation in ohmic heating is achieved by both thermal and non - thermal cellular damage from the electrical field. this method destroys microorganisms due to electroporation of cell membranes, physical membrane rupture, and cell lysis. in electroporation, excessive leakage of ions and intramolecular components results in cell death. in membrane rupture, cells swell due to an increase in moisture diffusion across the cell membrane. pronounced disruption and decomposition of cell walls and cytoplasmic membranes causes cells to lyse. decreased processing times in ohmic heating maintains nutritional and sensory properties of foods. ohmic heating inactivates antinutritional factors like lipoxigenase ( lox ), polyphenoloxidase ( ppo ), and pectinase due to the removal of active metallic groups in enzymes by the electrical field. similar to other heating methods, ohmic heating causes gelatinization of starches, melting of fats, and protein agglutination. water - soluble nutrients are maintained in the suspension liquid allowing for no loss of nutritional value if the liquid is consumed. ohmic heating is limited by viscosity, electrical conductivity, and fouling deposits. the density of particles within the suspension liquid can limit the degree of processing. a higher viscosity fluid will provide more resistance to heating, allowing the mixture to heat up quicker than low viscosity products. a food product's electrical conductivity is a function of temperature, frequency, and product composition. this may be increased by adding ionic compounds, or decreased by adding non - polar constituents. changes in electrical conductivity limit ohmic heating as it is difficult to model the thermal process when temperature increases in multi - component foods. the potential applications of ohmic heating range
computational gastronomy is an interdisciplinary field combining computational science with culinary studies. it applies data - driven techniques to analyze various aspects of food, including recipes, flavors, nutrition, and sustainability. the field utilizes advancements in data analytics, machine learning, and computational models to systematically study food and optimize culinary practices. applications of computational gastronomy include recipe optimization, flavor profiling, nutritional analysis, and personalized dietary recommendations. = = overview = = the field of computational gastronomy aims to enhance understanding and innovation in culinary science through computational tools. by analyzing the relationships between food components, health, and flavor, researchers seek to create innovative culinary experiences and improve food preparation techniques. despite its potential, the field faces challenges such as the lack of high - quality, well - structured datasets, particularly for traditional recipes, and the inherent subjectivity of sensory experiences like taste. = = techniques and applications = = = = = recipe optimization = = = computational methods are employed to analyze and optimize recipes by identifying patterns in ingredient ratios, cooking times, and temperature controls. these analyses lead to more efficient cooking processes and the creation of flavorful and nutritious dishes. = = = flavor profiling and pairing = = = by studying the chemical composition of food, computational gastronomy enables the prediction of flavor profiles and suitable pairings. this knowledge is applied to enhance dining experiences through scientifically informed menu design. = = = nutritional optimization = = = the field contributes to the optimization of nutritional content in meals while balancing taste, texture, and cost. computational models analyze ingredient data to create healthier dishes, accommodating specific dietary requirements such as low - calorie, low - fat, or gluten - free diets. = = = novel recipe generation = = = using natural language processing ( nlp ) and machine learning models, computational gastronomy facilitates the generation of unique recipes. models such as long short - term memory ( lstm ) networks and gpt - 2 have been trained on extensive recipe datasets to synthesize ingredient lists and cooking instructions, supporting culinary creativity and personalized cooking experiences. = = = personalized nutrition = = = the field integrates physiological and genetic data to develop tailored dietary plans. personalized nutrition aims to manage chronic diseases, enhance athletic performance, and improve overall health through customized meal recommendations. = = = traditional cuisine analysis = = = by analyzing traditional recipes and culinary techniques, computational gastronomy explores the cultural and historical significance of food. insights from
Answer:
|
scorching power
| null |
cooking food requires adding what?
0. frozen water
1. scorching power
2. coldness
3. air
conditions, reduce energy consumption, and improve city services. = = = heating, cooling and cooking = = = heating, cooling and cooking are also targets for improved energy efficiency and reduction of carbon emissions. increasingly following europe and asia, north americans are switching from gas or electrical resistance stoves to induction cooking. consumers are also switching heating systems from coal, fuel oil, or natural gas to electricity - driven steam or hot water ; and to air - source or ground - source heat pumps for both heating and cooling. = = = food = = = food production tends to be heavily dependent on fossil fuels, in the production of nitrogen fertilizer and to power agricultural machinery used in the planting, tending and harvesting of crops. the movement of food from producers to consumers also tends to involve major fossil - fuel costs, since many crops are grown far from their potential market and have a short shelf life. many countries depend on international markets to obtain critical food supplies. food production and supply chains are being increasingly destabilized by the effects of climate change on agriculture, the covid - 19 pandemic, and the russian invasion of ukraine. in the united states, at the same time that millions of americans experience food insecurity, as much as 40 percent of food is wasted. at the consumer level, steps towards achieving net zero include eating more local and plant - based foods, minimizing food waste, and composting remaining plant - based wastes. consumers and investors may also choose to support companies based on their carbon footprint and transparency. in terms of city infrastructure, initiatives to identify and redirect usable food ( " food rescue " ), to separate waste streams, and to improve handling of food waste are all important. in low - income countries, small - scale and household - level biogas systems are being used to convert wastes into energy. composting and anaerobic digestion ( ad ) are increasingly being used in countries at all income levels. farmers and farming communities need scientific, technical, and financial support to move to more climate - friendly farming practices and to support initiatives for climate change adaptation, regenerative agriculture and biosequestration. collaboration between stakeholders at all levels of the private, public and civil sectors is needed to improve food sector infrastructure. = = = construction = = = the energy efficiency of buildings can be assessed and improved in multiple ways that help to reduce carbon emissions. insulation and energy - efficient windows are commonly used in colder cities. incorporation of features such as solar panels, green roofs and walls
and sensory properties. however, ohmic heating is limited by viscosity, electrical conductivity, and fouling deposits. although ohmic heating has not yet been approved by the food and drug administration ( fda ) for commercial use, this method has many potential applications, ranging from cooking to fermentation. there are different configurations for continuous ohmic heating systems, but in the most basic process, a power supply or generator is needed to produce electrical current. electrodes, in direct contact with food, pass electric current through the matrix. the distance between the electrodes can be adjusted to achieve the optimum electrical field strength. the generator creates the electrical current which flows to the first electrode and passes through the food product placed in the electrode gap. the food product resists the flow of current causing internal heating. the current continues to flow to the second electrode and back to the power source to close the circuit. the insulator caps around the electrodes controls the environment within the system. the electrical field strength and the residence time are the key process parameters which affect heat generation. the ideal foods for ohmic heating are viscous with particulates. thick soups sauces stews salsa fruit in a syrup medium milk ice cream mix egg whey heat sensitive liquids soymilk the efficiency by which electricity is converted to heat depends upon on salt, water, and fat content due to their thermal conductivity and resistance factors. in particulate foods, the particles heat up faster than the liquid matrix due to higher resistance to electricity and matching conductivity can contribute to uniform heating. this prevents overheating of the liquid matrix while particles receive sufficient heat processing. table 1 shows the electrical conductivity values of certain foods to display the effect of composition and salt concentration. the high electrical conductivity values represent a larger number of ionic compounds suspended in the product, which is directly proportional to the rate of heating. this value is increased in the presence of polar compounds, like acids and salts, but decreased with nonpolar compounds, like fats. electrical conductivity of food materials generally increases with temperature, and can change if there are structural changes caused during heating such as gelatinization of starch. density, ph, and specific heat of various components in a food matrix can also influence heating rate. benefits of ohmic heating include : uniform and rapid heating ( > 1Β°csβ1 ), less cooking time, better energy efficiency, lower capital cost, and heating simulataneously throughout food's volume as compared to aseptic processing, canning,
and simmering are popular cooking methods that often require immersing food in water or its gaseous state, steam. water is also used for dishwashing. water also plays many critical roles within the field of food science. solutes such as salts and sugars found in water affect the physical properties of water. the boiling and freezing points of water are affected by solutes, as well as air pressure, which is in turn affected by altitude. water boils at lower temperatures with the lower air pressure that occurs at higher elevations. one mole of sucrose ( sugar ) per kilogram of water raises the boiling point of water by 0. 51 Β°c ( 0. 918 Β°f ), and one mole of salt per kg raises the boiling point by 1. 02 Β°c ( 1. 836 Β°f ) ; similarly, increasing the number of dissolved particles lowers water's freezing point. solutes in water also affect water activity that affects many chemical reactions and the growth of microbes in food. water activity can be described as a ratio of the vapor pressure of water in a solution to the vapor pressure of pure water. solutes in water lower water activity β this is important to know because most bacterial growth ceases at low levels of water activity. not only does microbial growth affect the safety of food, but also the preservation and shelf life of food. water hardness is also a critical factor in food processing and may be altered or treated by using a chemical ion exchange system. it can dramatically affect the quality of a product, as well as playing a role in sanitation. water hardness is classified based on concentration of calcium carbonate the water contains. water is classified as soft if it contains less than 100 mg / l ( uk ) or less than 60 mg / l ( us ). according to a report published by the water footprint organization in 2010, a single kilogram of beef requires 15 thousand litres ( 3. 3Γ10 ^ 3 imp gal ; 4. 0Γ10 ^ 3 us gal ) of water ; however, the authors also make clear that this is a global average and circumstantial factors determine the amount of water used in beef production. = = = = medical use = = = = water for injection is on the world health organization's list of essential medicines. = = distribution in nature = = = = = in the universe = = = much of the universe's water is produced as a byproduct of star formation. the formation of stars is accompanied by a strong outward
ohmic heating include : uniform and rapid heating ( > 1Β°csβ1 ), less cooking time, better energy efficiency, lower capital cost, and heating simulataneously throughout food's volume as compared to aseptic processing, canning, and pef. volumetric heating allows internal heating instead of transferring heat from a secondary medium. this results in the production of safe, high quality food with minimal changes to structural, nutritional, and organoleptic properties of food. heat transfer is uniform to reach areas of food that are harder to heat. less fouling accumulates on the electrodes as compared to other heating methods. ohmic heating also requires less cleaning and maintenance, resulting in an environmentally cautious heating method. microbial inactivation in ohmic heating is achieved by both thermal and non - thermal cellular damage from the electrical field. this method destroys microorganisms due to electroporation of cell membranes, physical membrane rupture, and cell lysis. in electroporation, excessive leakage of ions and intramolecular components results in cell death. in membrane rupture, cells swell due to an increase in moisture diffusion across the cell membrane. pronounced disruption and decomposition of cell walls and cytoplasmic membranes causes cells to lyse. decreased processing times in ohmic heating maintains nutritional and sensory properties of foods. ohmic heating inactivates antinutritional factors like lipoxigenase ( lox ), polyphenoloxidase ( ppo ), and pectinase due to the removal of active metallic groups in enzymes by the electrical field. similar to other heating methods, ohmic heating causes gelatinization of starches, melting of fats, and protein agglutination. water - soluble nutrients are maintained in the suspension liquid allowing for no loss of nutritional value if the liquid is consumed. ohmic heating is limited by viscosity, electrical conductivity, and fouling deposits. the density of particles within the suspension liquid can limit the degree of processing. a higher viscosity fluid will provide more resistance to heating, allowing the mixture to heat up quicker than low viscosity products. a food product's electrical conductivity is a function of temperature, frequency, and product composition. this may be increased by adding ionic compounds, or decreased by adding non - polar constituents. changes in electrical conductivity limit ohmic heating as it is difficult to model the thermal process when temperature increases in multi - component foods. the potential applications of ohmic heating range
computational gastronomy is an interdisciplinary field combining computational science with culinary studies. it applies data - driven techniques to analyze various aspects of food, including recipes, flavors, nutrition, and sustainability. the field utilizes advancements in data analytics, machine learning, and computational models to systematically study food and optimize culinary practices. applications of computational gastronomy include recipe optimization, flavor profiling, nutritional analysis, and personalized dietary recommendations. = = overview = = the field of computational gastronomy aims to enhance understanding and innovation in culinary science through computational tools. by analyzing the relationships between food components, health, and flavor, researchers seek to create innovative culinary experiences and improve food preparation techniques. despite its potential, the field faces challenges such as the lack of high - quality, well - structured datasets, particularly for traditional recipes, and the inherent subjectivity of sensory experiences like taste. = = techniques and applications = = = = = recipe optimization = = = computational methods are employed to analyze and optimize recipes by identifying patterns in ingredient ratios, cooking times, and temperature controls. these analyses lead to more efficient cooking processes and the creation of flavorful and nutritious dishes. = = = flavor profiling and pairing = = = by studying the chemical composition of food, computational gastronomy enables the prediction of flavor profiles and suitable pairings. this knowledge is applied to enhance dining experiences through scientifically informed menu design. = = = nutritional optimization = = = the field contributes to the optimization of nutritional content in meals while balancing taste, texture, and cost. computational models analyze ingredient data to create healthier dishes, accommodating specific dietary requirements such as low - calorie, low - fat, or gluten - free diets. = = = novel recipe generation = = = using natural language processing ( nlp ) and machine learning models, computational gastronomy facilitates the generation of unique recipes. models such as long short - term memory ( lstm ) networks and gpt - 2 have been trained on extensive recipe datasets to synthesize ingredient lists and cooking instructions, supporting culinary creativity and personalized cooking experiences. = = = personalized nutrition = = = the field integrates physiological and genetic data to develop tailored dietary plans. personalized nutrition aims to manage chronic diseases, enhance athletic performance, and improve overall health through customized meal recommendations. = = = traditional cuisine analysis = = = by analyzing traditional recipes and culinary techniques, computational gastronomy explores the cultural and historical significance of food. insights from
Answer:
|
air
| 0.3 |
Tropical storms get their fuel from the
0. super market
1. ocean
2. gas station
3. mexico
, which is water brought to the surface along with the oil and gas ; it is usually highly saline and may include dissolved or unseparated hydrocarbons. offshore rigs are shut down during hurricanes. in the gulf of mexico the number hurricanes is increasing because of the increasing number of oil platforms that heat surrounding air with methane. it is estimated that oil and gas facilities in the gulf of mexico emit approximately 500000 tons of methane each year, corresponding to a 2. 9 % loss of produced gas. the increasing number of oil rigs also increases the number and movement of oil tankers, resulting in increasing co2 levels which directly warm water in the zone. warm waters are a key factor for hurricanes to form. to reduce the amount of carbon emissions otherwise released into the atmosphere, methane pyrolysis of natural gas pumped up by oil platforms is a possible alternative to flaring for consideration. methane pyrolysis produces non - polluting hydrogen in high volume from this natural gas at low cost. this process operates at around 1000 Β°c and removes carbon in a solid form from the methane, producing hydrogen. the carbon can then be pumped underground and is not released into the atmosphere. it is being evaluated in such research laboratories as karlsruhe liquid - metal laboratory ( kalla ). and the chemical engineering team at university of california β santa barbara = = repurposing = = if not decommissioned, old platforms can be repurposed to pump co2 into rocks below the seabed. others have been converted to launch rockets into space, and more are being redesigned for use with heavy - lift launch vehicles. in saudi arabia, there are plans to repurpose decommissioned oil rigs into a theme park. = = challenges = = offshore oil and gas production is more challenging than land - based installations due to the remote and harsher environment. much of the innovation in the offshore petroleum sector concerns overcoming these challenges, including the need to provide very large production facilities. production and drilling facilities may be very large and a large investment, such as the troll a platform standing on a depth of 300 meters. another type of offshore platform may float with a mooring system to maintain it on location. while a floating system may be lower cost in deeper waters than a fixed platform, the dynamic nature of the platforms introduces many challenges for the drilling and production facilities. the ocean can add several thousand meters or more to the fluid column. the addition increases the equivalent circulating density and downhole pressures in drilling wells, as well as the energy needed to lift produced fluids
supercooled, at which point it will freeze upon impact with any object encountered sleet β term used in the united states and canada for precipitation consisting of small, translucent ice balls, usually smaller than hailstones tropical cyclone β a storm system with a low - pressure center and numerous thunderstorms that produce strong winds and flooding rain extratropical cyclone β a low - pressure weather system occurring in the middle latitudes of the earth having neither tropical nor polar characteristics weather front β a boundary separating two masses of air of different densities ; the principal cause of meteorological phenomena low pressure β a region where the atmospheric pressure is lower in relation to the surrounding area storm β any disturbed state of the atmosphere and strongly implying severe weather flooding β an overflow of an expanse of water that submerges the land ; a deluge nor'easter β a macro - scale storm along the east coast of the united states, named for the winds that come from the northeast wind β the flow of air or other gases that compose an atmosphere ; caused by rising heated air and cooler air rushing in to occupy the vacated space. temperature β a physical property that describes our common notions of hot and cold invest ( meteorology ) β an area with the potential for tropical cyclone development = = = weather - related disasters = = = weather disasters extreme weather list of floods list of natural disasters by death toll list of severe weather phenomena = = leaders in meteorology = = william m. gray ( october 9, 1929 β april 16, 2016 ) β has been involved in forecasting hurricanes since 1984 francis galton ( february 16, 1822 - january 17, 1911 ) β was a polymath, and devised the first weather map, proposed a theory of anticyclones, and was the first to establish a complete record of short - term climatic phenomena on a european scale herbert saffir ( march 29, 1917 β november 21, 2007 ) β was the developer of the saffir - simpson hurricane scale for measuring the intensity of hurricanes bob simpson ( november 19, 1912 β december 18, 2014 ) β was a meteorologist, hurricane specialist, first director of the national hurricane research project, former director of the national hurricane center, and co - developer of the saffir - simpson hurricane scale. = = see also = = meteorology glossary of meteorology index of meteorology articles standard day jet stream heat index equivalent potential temperature ( theta - e ) primitive equations climate : el nino monsoon flood drought global warming effect of sun angle on climate other phenomena : deposition dust devil fog tide air
wind setup, also known as wind effect or storm effect, refers to the rise in water level in seas, lakes, or other large bodies of water caused by winds pushing the water in a specific direction. as the wind moves across the water β s surface, it applies shear stress to the water, generating a wind - driven current. when this current encounters a shoreline, the water level increases due to the accumulation of water, which creates a hydrostatic counterforce that balances the shear force applied by the wind. during storms, wind setup forms part of the overall storm surge. for example, in the netherlands, wind setup during a storm surge can raise water levels by as much as 3 metres above normal tidal levels. in tropical regions, such as the caribbean, wind setup during cyclones can elevate water levels by up to 5 metres. this phenomenon becomes especially significant when water is funnelled into shallow or narrow areas, leading to higher storm surges. examples of the effects of wind setup include hurricanes gamma and delta in 2020, during which wind setup was a major factor when strong winds and atmospheric pressure drops caused higher - than - expected coastal flooding across the yucatan peninsula in mexico. similarly, in california β s suisun marsh, wind setup has been show to be a significant factor affecting local water levels, with strong winds pushing water into levees, contributing to frequent breaches and flooding. = = observation = = in lakes, wind setup often leads to noticeable fluctuations in water levels. this effect is particularly clear in lakes with well - regulated water levels, such as the ijsselmeer, where the relationship between wind speed, water depth, and fetch length can be accurately measured and observed. at sea, however, wind setup is typically masked by other factors, such as tidal variations. to measure the wind setup effect in coastal areas, the ( calculated ) astronomical tide is subtracted from the observed water level. for instance, during the north sea flood of 1953, the highest water level along the dutch coast was recorded at 2. 79 metres at the vlissingen tidal station, while the highest wind setup β measuring 3. 52 metres β was observed at scheveningen. the highest wind setup ever recorded in the netherlands, reaching 3. 63 metres, occurred in dintelsas, steenbergen during the 1953 flood. however, globally, tropical regions like the gulf of mexico and the caribbean often experience even higher wind setups during hurricane events, underscoring the importance of this phenomenon in coastal and flood management strategies. =
them with cooler water from below in the process known as ekman transport. this pattern generally increases nutrients for marine life in the region, and can have a profound effect in some regions where the bottom waters are particularly nutrient - rich. offshore of river deltas, freshwater flows over the top of the denser seawater, which allows it to heat faster due to limited vertical mixing. remotely sensed sst can be used to detect the surface temperature signature due to tropical cyclones. in general, an sst cooling is observed after the passing of a hurricane, primarily as the result of mixed layer deepening and surface heat losses. in the wake of several day long saharan dust outbreaks across the adjacent northern atlantic ocean, sea surface temperatures are reduced 0. 2 c to 0. 4 c ( 0. 3 to 0. 7 f ). other sources of short - term sst fluctuation include extratropical cyclones, rapid influxes of glacial fresh water and concentrated phytoplankton blooms due to seasonal cycles or agricultural run - off. the tropical ocean has been warming faster than other regions since 1950, with the greatest rates of warming in the tropical indian ocean, western pacific ocean, and western boundary currents of the subtropical gyres. however, the eastern pacific ocean, subtropical north atlantic ocean, and southern ocean have warmed more slowly than the global average or have experienced cooling since the 1950s. = = = = atlantic multidecadal oscillation = = = = ocean currents, such as the atlantic multidecadal oscillation, can affect sea surface temperatures over several decades. the atlantic multidecadal oscillation ( amo ) is an important driver of north atlantic sst and northern hemisphere climate, but the mechanisms controlling amo variability remain poorly understood. atmospheric internal variability, changes in ocean circulation, or anthropogenic drivers may control the multidecadal temperature variability associated with amo. these changes in north atlantic sst may influence winds in the subtropical north pacific and produce warmer ssts in the western pacific ocean. = = = regional variations = = = el nino is defined by prolonged differences in pacific ocean surface temperatures when compared with the average value. the accepted definition is a warming or cooling of at least 0. 5 Β°c ( 0. 9 Β°f ) averaged over the east - central tropical pacific ocean. typically, this anomaly happens at irregular intervals of 2 β 7 years and lasts nine months to two years. the average period length is 5 years. when this warming or cooling occurs for only seven to nine months
national map ( in the us ) national oceanic and atmospheric administration ( noaa ) ( in the us ) ( national severe storms forecast center [ nssfc ] : renamed ) storm prediction center ( spc ) ( in the us ) national severe storms laboratory ( nssl ) ( in the us ) national snow and ice data center ( nsidc ) ( in the us ) national solar observatory ( in the us ) national weather association ( nwa ) ( in the us ) national weather center ( nwc ) ( in the us ) national weather service bulletin for new orleans region ( at 10 : 11 a. m., august 28, 2005 ) national weather service ( nws ) nautical almanac nephology nephoscope night sky nimbus cloud nitrogen cycle ( nitrogen pollution : see ) eutrophication ( see under atmospheric deposition ) noaa weather radio all hazards ( nwr ) ( of the us ) noctilucent cloud north atlantic tropical cyclone north pole numerical weather prediction = = o = = observational astronomy ( see " light pollution " in places ) observatory ( see also list of observatories ) ocean heat content ( ohc ) ocean prediction center ( ohc ) occultation oceanic climate office of oceanic and atmospheric research ( oar ) 1999 oklahoma tornado outbreak orographic lift outflow boundary oxygen oxygen cycle ozone ozone depletion ozone depletion potential ( odp ) ozone layer ( ozonosphere layer ) ozone - oxygen cycle = = p = = pacific decadal oscillation paleoclimatology paleomagnetism paleotempestology parts - per notation photovore planetary boundary layer ( pbl ) pluvial lake pneumonia front polar circle polar climate polar easterlies polar high polar ice cap ( polar light : see ) aurora ( astronomy ) polar low ( polar mesospheric cloud ) noctilucent cloud polar mesospheric summer echoes ( pmse ) polar night polar region ( polar reversal ) magnetic polarity reversal polar stratospheric cloud ( psc ) ( nacreous cloud ) polar vortex polarization ( waves ) ( see under polarization effects in everyday life ) pole shift theory positive streamer post - glacial rebound potential evaporation potential temperature precipitation pressure gradient pressure gradient force ( pgf ) pyrocumulus = = q = = quantitative precipitation estimation quantitative precipitation forecast quasi - geostrophic equations = = r = = radiance radiant barrier radiant energy radiation radiation budget radiation hormesis radiation poisoning ( radiation sickness ) ra
Answer:
|
ocean
| null |
Tropical storms get their fuel from the
0. super market
1. ocean
2. gas station
3. mexico
, which is water brought to the surface along with the oil and gas ; it is usually highly saline and may include dissolved or unseparated hydrocarbons. offshore rigs are shut down during hurricanes. in the gulf of mexico the number hurricanes is increasing because of the increasing number of oil platforms that heat surrounding air with methane. it is estimated that oil and gas facilities in the gulf of mexico emit approximately 500000 tons of methane each year, corresponding to a 2. 9 % loss of produced gas. the increasing number of oil rigs also increases the number and movement of oil tankers, resulting in increasing co2 levels which directly warm water in the zone. warm waters are a key factor for hurricanes to form. to reduce the amount of carbon emissions otherwise released into the atmosphere, methane pyrolysis of natural gas pumped up by oil platforms is a possible alternative to flaring for consideration. methane pyrolysis produces non - polluting hydrogen in high volume from this natural gas at low cost. this process operates at around 1000 Β°c and removes carbon in a solid form from the methane, producing hydrogen. the carbon can then be pumped underground and is not released into the atmosphere. it is being evaluated in such research laboratories as karlsruhe liquid - metal laboratory ( kalla ). and the chemical engineering team at university of california β santa barbara = = repurposing = = if not decommissioned, old platforms can be repurposed to pump co2 into rocks below the seabed. others have been converted to launch rockets into space, and more are being redesigned for use with heavy - lift launch vehicles. in saudi arabia, there are plans to repurpose decommissioned oil rigs into a theme park. = = challenges = = offshore oil and gas production is more challenging than land - based installations due to the remote and harsher environment. much of the innovation in the offshore petroleum sector concerns overcoming these challenges, including the need to provide very large production facilities. production and drilling facilities may be very large and a large investment, such as the troll a platform standing on a depth of 300 meters. another type of offshore platform may float with a mooring system to maintain it on location. while a floating system may be lower cost in deeper waters than a fixed platform, the dynamic nature of the platforms introduces many challenges for the drilling and production facilities. the ocean can add several thousand meters or more to the fluid column. the addition increases the equivalent circulating density and downhole pressures in drilling wells, as well as the energy needed to lift produced fluids
supercooled, at which point it will freeze upon impact with any object encountered sleet β term used in the united states and canada for precipitation consisting of small, translucent ice balls, usually smaller than hailstones tropical cyclone β a storm system with a low - pressure center and numerous thunderstorms that produce strong winds and flooding rain extratropical cyclone β a low - pressure weather system occurring in the middle latitudes of the earth having neither tropical nor polar characteristics weather front β a boundary separating two masses of air of different densities ; the principal cause of meteorological phenomena low pressure β a region where the atmospheric pressure is lower in relation to the surrounding area storm β any disturbed state of the atmosphere and strongly implying severe weather flooding β an overflow of an expanse of water that submerges the land ; a deluge nor'easter β a macro - scale storm along the east coast of the united states, named for the winds that come from the northeast wind β the flow of air or other gases that compose an atmosphere ; caused by rising heated air and cooler air rushing in to occupy the vacated space. temperature β a physical property that describes our common notions of hot and cold invest ( meteorology ) β an area with the potential for tropical cyclone development = = = weather - related disasters = = = weather disasters extreme weather list of floods list of natural disasters by death toll list of severe weather phenomena = = leaders in meteorology = = william m. gray ( october 9, 1929 β april 16, 2016 ) β has been involved in forecasting hurricanes since 1984 francis galton ( february 16, 1822 - january 17, 1911 ) β was a polymath, and devised the first weather map, proposed a theory of anticyclones, and was the first to establish a complete record of short - term climatic phenomena on a european scale herbert saffir ( march 29, 1917 β november 21, 2007 ) β was the developer of the saffir - simpson hurricane scale for measuring the intensity of hurricanes bob simpson ( november 19, 1912 β december 18, 2014 ) β was a meteorologist, hurricane specialist, first director of the national hurricane research project, former director of the national hurricane center, and co - developer of the saffir - simpson hurricane scale. = = see also = = meteorology glossary of meteorology index of meteorology articles standard day jet stream heat index equivalent potential temperature ( theta - e ) primitive equations climate : el nino monsoon flood drought global warming effect of sun angle on climate other phenomena : deposition dust devil fog tide air
wind setup, also known as wind effect or storm effect, refers to the rise in water level in seas, lakes, or other large bodies of water caused by winds pushing the water in a specific direction. as the wind moves across the water β s surface, it applies shear stress to the water, generating a wind - driven current. when this current encounters a shoreline, the water level increases due to the accumulation of water, which creates a hydrostatic counterforce that balances the shear force applied by the wind. during storms, wind setup forms part of the overall storm surge. for example, in the netherlands, wind setup during a storm surge can raise water levels by as much as 3 metres above normal tidal levels. in tropical regions, such as the caribbean, wind setup during cyclones can elevate water levels by up to 5 metres. this phenomenon becomes especially significant when water is funnelled into shallow or narrow areas, leading to higher storm surges. examples of the effects of wind setup include hurricanes gamma and delta in 2020, during which wind setup was a major factor when strong winds and atmospheric pressure drops caused higher - than - expected coastal flooding across the yucatan peninsula in mexico. similarly, in california β s suisun marsh, wind setup has been show to be a significant factor affecting local water levels, with strong winds pushing water into levees, contributing to frequent breaches and flooding. = = observation = = in lakes, wind setup often leads to noticeable fluctuations in water levels. this effect is particularly clear in lakes with well - regulated water levels, such as the ijsselmeer, where the relationship between wind speed, water depth, and fetch length can be accurately measured and observed. at sea, however, wind setup is typically masked by other factors, such as tidal variations. to measure the wind setup effect in coastal areas, the ( calculated ) astronomical tide is subtracted from the observed water level. for instance, during the north sea flood of 1953, the highest water level along the dutch coast was recorded at 2. 79 metres at the vlissingen tidal station, while the highest wind setup β measuring 3. 52 metres β was observed at scheveningen. the highest wind setup ever recorded in the netherlands, reaching 3. 63 metres, occurred in dintelsas, steenbergen during the 1953 flood. however, globally, tropical regions like the gulf of mexico and the caribbean often experience even higher wind setups during hurricane events, underscoring the importance of this phenomenon in coastal and flood management strategies. =
them with cooler water from below in the process known as ekman transport. this pattern generally increases nutrients for marine life in the region, and can have a profound effect in some regions where the bottom waters are particularly nutrient - rich. offshore of river deltas, freshwater flows over the top of the denser seawater, which allows it to heat faster due to limited vertical mixing. remotely sensed sst can be used to detect the surface temperature signature due to tropical cyclones. in general, an sst cooling is observed after the passing of a hurricane, primarily as the result of mixed layer deepening and surface heat losses. in the wake of several day long saharan dust outbreaks across the adjacent northern atlantic ocean, sea surface temperatures are reduced 0. 2 c to 0. 4 c ( 0. 3 to 0. 7 f ). other sources of short - term sst fluctuation include extratropical cyclones, rapid influxes of glacial fresh water and concentrated phytoplankton blooms due to seasonal cycles or agricultural run - off. the tropical ocean has been warming faster than other regions since 1950, with the greatest rates of warming in the tropical indian ocean, western pacific ocean, and western boundary currents of the subtropical gyres. however, the eastern pacific ocean, subtropical north atlantic ocean, and southern ocean have warmed more slowly than the global average or have experienced cooling since the 1950s. = = = = atlantic multidecadal oscillation = = = = ocean currents, such as the atlantic multidecadal oscillation, can affect sea surface temperatures over several decades. the atlantic multidecadal oscillation ( amo ) is an important driver of north atlantic sst and northern hemisphere climate, but the mechanisms controlling amo variability remain poorly understood. atmospheric internal variability, changes in ocean circulation, or anthropogenic drivers may control the multidecadal temperature variability associated with amo. these changes in north atlantic sst may influence winds in the subtropical north pacific and produce warmer ssts in the western pacific ocean. = = = regional variations = = = el nino is defined by prolonged differences in pacific ocean surface temperatures when compared with the average value. the accepted definition is a warming or cooling of at least 0. 5 Β°c ( 0. 9 Β°f ) averaged over the east - central tropical pacific ocean. typically, this anomaly happens at irregular intervals of 2 β 7 years and lasts nine months to two years. the average period length is 5 years. when this warming or cooling occurs for only seven to nine months
national map ( in the us ) national oceanic and atmospheric administration ( noaa ) ( in the us ) ( national severe storms forecast center [ nssfc ] : renamed ) storm prediction center ( spc ) ( in the us ) national severe storms laboratory ( nssl ) ( in the us ) national snow and ice data center ( nsidc ) ( in the us ) national solar observatory ( in the us ) national weather association ( nwa ) ( in the us ) national weather center ( nwc ) ( in the us ) national weather service bulletin for new orleans region ( at 10 : 11 a. m., august 28, 2005 ) national weather service ( nws ) nautical almanac nephology nephoscope night sky nimbus cloud nitrogen cycle ( nitrogen pollution : see ) eutrophication ( see under atmospheric deposition ) noaa weather radio all hazards ( nwr ) ( of the us ) noctilucent cloud north atlantic tropical cyclone north pole numerical weather prediction = = o = = observational astronomy ( see " light pollution " in places ) observatory ( see also list of observatories ) ocean heat content ( ohc ) ocean prediction center ( ohc ) occultation oceanic climate office of oceanic and atmospheric research ( oar ) 1999 oklahoma tornado outbreak orographic lift outflow boundary oxygen oxygen cycle ozone ozone depletion ozone depletion potential ( odp ) ozone layer ( ozonosphere layer ) ozone - oxygen cycle = = p = = pacific decadal oscillation paleoclimatology paleomagnetism paleotempestology parts - per notation photovore planetary boundary layer ( pbl ) pluvial lake pneumonia front polar circle polar climate polar easterlies polar high polar ice cap ( polar light : see ) aurora ( astronomy ) polar low ( polar mesospheric cloud ) noctilucent cloud polar mesospheric summer echoes ( pmse ) polar night polar region ( polar reversal ) magnetic polarity reversal polar stratospheric cloud ( psc ) ( nacreous cloud ) polar vortex polarization ( waves ) ( see under polarization effects in everyday life ) pole shift theory positive streamer post - glacial rebound potential evaporation potential temperature precipitation pressure gradient pressure gradient force ( pgf ) pyrocumulus = = q = = quantitative precipitation estimation quantitative precipitation forecast quasi - geostrophic equations = = r = = radiance radiant barrier radiant energy radiation radiation budget radiation hormesis radiation poisoning ( radiation sickness ) ra
Answer:
|
gas station
| 0.3 |
Lions and zebras live
0. in different environments
1. near each other
2. in different habitats
3. far from Earth
and a female lion ; however, tigers and lions have thus far only hybridized in captivity. in both ligers and tigons, the females are fertile and the males are sterile. one of these hybrids ( the tigon ) carries growth - inhibitor genes from both parents and thus is smaller than either parent species and might in the wild come into competition with smaller carnivores, e. g. the leopard. the other hybrid, the liger, ends up larger than either of its parents : about a thousand pounds ( 450 kilograms ) fully grown. no tiger - lion hybrids are known from the wild, and the ranges of the two species no longer overlap ( tigers are not found in africa, and while there was formerly overlap in the distribution of the two species in asia, both have been extirpated from much of their respective historic ranges, and the asiatic lion is now restricted to the gir forest national park, where tigers are mostly absent ). some situations may favor hybrid population. one example is rapid turnover of available environment types, like the historical fluctuation of water level in lake malawi, a situation that generally favors speciation. a similar situation can be found where closely related species occupy a chain of islands. this will allow any present hybrid population to move into new, unoccupied habitats, avoiding direct competition with parent species and giving a hybrid population time and space to establish. genetics, too, can occasionally favor hybrids. in the amboseli national park in kenya, yellow baboons and anubis baboons regularly interbreed. the hybrid males reach maturity earlier than their pure - bred cousins, setting up a situation where the hybrid population may over time replace one or both of the parent species in the area. = = genetics of hybridization = = genetics are more variable and malleable in plants than in animals, probably reflecting the higher activity level in animals. hybrids'genetics will necessarily be less stable than those of species evolving through isolation, which explains why hybrid species appear more common in plants than in animals. many agricultural crops are hybrids with double or even triple chromosome sets. having multiple sets of chromosomes is called polyploidy. polyploidy is usually fatal in animals where extra chromosome sets upset fetal development, but is often found in plants. a form of hybrid speciation that is relatively common in plants occurs when an infertile hybrid becomes fertile after doubling of the chromosome number. hybridization without change in chromosome number is called homoploid hybrid speciation. this is the
102 kg ( 225 lb ). when hunting medium to large sized prey, spotted hyenas tend to select certain categories of animal ; young animals are frequently targeted, as are old ones, though the latter category is not so significant when hunting zebras, due to their aggressive anti - predator behaviours. small prey is killed by being shaken in the mouth, while large prey is eaten alive. the spotted hyena tracks live prey by sight, hearing and smell. carrion is detected by smell and the sound of other predators feeding. during daylight hours, they watch vultures descending upon carcasses. their auditory perception is powerful enough to detect sounds of predators killing prey or feeding on carcasses over distances of up to 10 km ( 6. 2 mi ). unlike the grey wolf, the spotted hyena relies more on sight than smell when hunting, and does not follow its prey's prints or travel in single file. spotted hyenas usually hunt wildebeest either singly, or in groups of two or three. they catch adult wildebeest usually after 5 km ( 3. 1 mi ) chases at speeds of up to 60 km / h ( 37 mi / h ). chases are usually initiated by one hyena and, with the exception of cows with calves, there is little active defence from the wildebeest herd. wildebeest will sometimes attempt to escape hyenas by taking to water although, in such cases, the hyenas almost invariably catch them. zebras require different hunting methods to those used for wildebeest, due to their habit of running in tight groups and aggressive defence from stallions. typical zebra hunting groups consist of 10 β 25 hyenas, though there is one record of a hyena killing an adult zebra unaided. during a chase, zebras typically move in tight bunches, with the hyenas pursuing behind in a crescent formation. chases are usually relatively slow, with an average speed of 15 β 30 km / h. a stallion will attempt to place himself between the hyenas and the herd, though once a zebra falls behind the protective formation it is immediately set upon, usually after a chase of 3 km ( 1. 9 mi ). though hyenas may harass the stallion, they usually only concentrate on the herd and attempt to dodge the stallion's assaults. unlike stallions, mares typically only react aggressively to hyenas when their foals are threatened. unlike wildebeest, zebras rarely take to water
they usually only concentrate on the herd and attempt to dodge the stallion's assaults. unlike stallions, mares typically only react aggressively to hyenas when their foals are threatened. unlike wildebeest, zebras rarely take to water when escaping hyenas. when hunting thomson's gazelles, spotted hyenas usually operate alone, and prey primarily on young fawns. chases against both adult and young gazelles can cover distances of 5 km ( 3. 1 mi ) with speeds of 60 km / h ( 37 mi / h ). female gazelles do not defend their fawns, though they may attempt to distract hyenas by feigning weakness. = = feeding habits = = a single spotted hyena can eat at least 14. 5 kg of meat per meal, and although they act aggressively toward each other when feeding, they compete with each other mostly through speed of eating, rather than by fighting as lions do. spotted hyenas can take less than two minutes to eat a gazelle fawn, while a group of 35 hyenas can completely consume an adult zebra in 36 minutes. spotted hyenas do not require much water, and typically only spend 30 seconds drinking. when feeding on an intact carcass, spotted hyenas will first consume the meat around the loins and anal region, then open the abdominal cavity and pull out the soft organs. once the stomach, its wall and contents are consumed, the hyenas will eat the lungs and abdominal and leg muscles. once the muscles have been eaten, the carcass is disassembled and the hyenas carry off pieces to eat in peace. spotted hyenas are adept at eating their prey in water : they have been observed to dive under floating carcasses to take bites, then resurface to swallow. the spotted hyena is very efficient at eating its prey ; not only is it able to splinter and eat the largest ungulate bones, it is also able to digest them completely. spotted hyenas can digest all organic components in bones, not just the marrow. any inorganic material is excreted with the faeces, which consist almost entirely of a white powder with few hairs. they react to alighting vultures more readily than other african carnivores, and are more likely to stay in the vicinity of lion kills or human settlements. = = references = = = = = bibliography = = = estes, richard ( 1992 ). the behavior
mass migrations take place, or used to take place, by the following mammals : africa : hartebeest springbok black wildebeest blue wildebeest blesbok tiang burchell's zebra quagga ( extinct ) thompson's gazelle mongalla gazelle white - eared kob grant's gazelle scimitar - horned oryx giant eland north america : pronghorn mule deer bison wapiti mexican free - tailed bat north america and eurasia : reindeer / caribou eurasia : siberian roe deer chiru kulan mongolian gazelle saiga of these migrations, those of the springbok, black wildebeest, blesbok, scimitar - horned oryx, and kulan have ceased. = = references = =
includes the cats, dogs, and bears ), 177 are solitary ; and 35 of the 37 wild cats are solitary, including the cougar and cheetah. however, the solitary cougar does allow other cougars to share in a kill, and the coyote can be either solitary or social. other solitary predators include the northern pike, wolf spiders and all the thousands of species of solitary wasps among arthropods, and many microorganisms and zooplankton. = = specialization = = = = = physical adaptations = = = under the pressure of natural selection, predators have evolved a variety of physical adaptations for detecting, catching, killing, and digesting prey. these include speed, agility, stealth, sharp senses, claws, teeth, filters, and suitable digestive systems. for detecting prey, predators have well - developed vision, smell, or hearing. predators as diverse as owls and jumping spiders have forward - facing eyes, providing accurate binocular vision over a relatively narrow field of view, whereas prey animals often have less acute all - round vision. animals such as foxes can smell their prey even when it is concealed under 2 feet ( 60 cm ) of snow or earth. many predators have acute hearing, and some such as echolocating bats hunt exclusively by active or passive use of sound. predators including big cats, birds of prey, and ants share powerful jaws, sharp teeth, or claws which they use to seize and kill their prey. some predators such as snakes and fish - eating birds like herons and cormorants swallow their prey whole ; some snakes can unhinge their jaws to allow them to swallow large prey, while fish - eating birds have long spear - like beaks that they use to stab and grip fast - moving and slippery prey. fish and other predators have developed the ability to crush or open the armoured shells of molluscs. many predators are powerfully built and can catch and kill animals larger than themselves ; this applies as much to small predators such as ants and shrews as to big and visibly muscular carnivores like the cougar and lion. = = = diet and behaviour = = = predators are often highly specialized in their diet and hunting behaviour ; for example, the eurasian lynx only hunts small ungulates. others such as leopards are more opportunistic generalists, preying on at least 100 species. the specialists may be highly adapted to capturing their preferred prey, whereas generalists may be better able to switch to other prey when
Answer:
|
near each other
| null |
Lions and zebras live
0. in different environments
1. near each other
2. in different habitats
3. far from Earth
and a female lion ; however, tigers and lions have thus far only hybridized in captivity. in both ligers and tigons, the females are fertile and the males are sterile. one of these hybrids ( the tigon ) carries growth - inhibitor genes from both parents and thus is smaller than either parent species and might in the wild come into competition with smaller carnivores, e. g. the leopard. the other hybrid, the liger, ends up larger than either of its parents : about a thousand pounds ( 450 kilograms ) fully grown. no tiger - lion hybrids are known from the wild, and the ranges of the two species no longer overlap ( tigers are not found in africa, and while there was formerly overlap in the distribution of the two species in asia, both have been extirpated from much of their respective historic ranges, and the asiatic lion is now restricted to the gir forest national park, where tigers are mostly absent ). some situations may favor hybrid population. one example is rapid turnover of available environment types, like the historical fluctuation of water level in lake malawi, a situation that generally favors speciation. a similar situation can be found where closely related species occupy a chain of islands. this will allow any present hybrid population to move into new, unoccupied habitats, avoiding direct competition with parent species and giving a hybrid population time and space to establish. genetics, too, can occasionally favor hybrids. in the amboseli national park in kenya, yellow baboons and anubis baboons regularly interbreed. the hybrid males reach maturity earlier than their pure - bred cousins, setting up a situation where the hybrid population may over time replace one or both of the parent species in the area. = = genetics of hybridization = = genetics are more variable and malleable in plants than in animals, probably reflecting the higher activity level in animals. hybrids'genetics will necessarily be less stable than those of species evolving through isolation, which explains why hybrid species appear more common in plants than in animals. many agricultural crops are hybrids with double or even triple chromosome sets. having multiple sets of chromosomes is called polyploidy. polyploidy is usually fatal in animals where extra chromosome sets upset fetal development, but is often found in plants. a form of hybrid speciation that is relatively common in plants occurs when an infertile hybrid becomes fertile after doubling of the chromosome number. hybridization without change in chromosome number is called homoploid hybrid speciation. this is the
102 kg ( 225 lb ). when hunting medium to large sized prey, spotted hyenas tend to select certain categories of animal ; young animals are frequently targeted, as are old ones, though the latter category is not so significant when hunting zebras, due to their aggressive anti - predator behaviours. small prey is killed by being shaken in the mouth, while large prey is eaten alive. the spotted hyena tracks live prey by sight, hearing and smell. carrion is detected by smell and the sound of other predators feeding. during daylight hours, they watch vultures descending upon carcasses. their auditory perception is powerful enough to detect sounds of predators killing prey or feeding on carcasses over distances of up to 10 km ( 6. 2 mi ). unlike the grey wolf, the spotted hyena relies more on sight than smell when hunting, and does not follow its prey's prints or travel in single file. spotted hyenas usually hunt wildebeest either singly, or in groups of two or three. they catch adult wildebeest usually after 5 km ( 3. 1 mi ) chases at speeds of up to 60 km / h ( 37 mi / h ). chases are usually initiated by one hyena and, with the exception of cows with calves, there is little active defence from the wildebeest herd. wildebeest will sometimes attempt to escape hyenas by taking to water although, in such cases, the hyenas almost invariably catch them. zebras require different hunting methods to those used for wildebeest, due to their habit of running in tight groups and aggressive defence from stallions. typical zebra hunting groups consist of 10 β 25 hyenas, though there is one record of a hyena killing an adult zebra unaided. during a chase, zebras typically move in tight bunches, with the hyenas pursuing behind in a crescent formation. chases are usually relatively slow, with an average speed of 15 β 30 km / h. a stallion will attempt to place himself between the hyenas and the herd, though once a zebra falls behind the protective formation it is immediately set upon, usually after a chase of 3 km ( 1. 9 mi ). though hyenas may harass the stallion, they usually only concentrate on the herd and attempt to dodge the stallion's assaults. unlike stallions, mares typically only react aggressively to hyenas when their foals are threatened. unlike wildebeest, zebras rarely take to water
they usually only concentrate on the herd and attempt to dodge the stallion's assaults. unlike stallions, mares typically only react aggressively to hyenas when their foals are threatened. unlike wildebeest, zebras rarely take to water when escaping hyenas. when hunting thomson's gazelles, spotted hyenas usually operate alone, and prey primarily on young fawns. chases against both adult and young gazelles can cover distances of 5 km ( 3. 1 mi ) with speeds of 60 km / h ( 37 mi / h ). female gazelles do not defend their fawns, though they may attempt to distract hyenas by feigning weakness. = = feeding habits = = a single spotted hyena can eat at least 14. 5 kg of meat per meal, and although they act aggressively toward each other when feeding, they compete with each other mostly through speed of eating, rather than by fighting as lions do. spotted hyenas can take less than two minutes to eat a gazelle fawn, while a group of 35 hyenas can completely consume an adult zebra in 36 minutes. spotted hyenas do not require much water, and typically only spend 30 seconds drinking. when feeding on an intact carcass, spotted hyenas will first consume the meat around the loins and anal region, then open the abdominal cavity and pull out the soft organs. once the stomach, its wall and contents are consumed, the hyenas will eat the lungs and abdominal and leg muscles. once the muscles have been eaten, the carcass is disassembled and the hyenas carry off pieces to eat in peace. spotted hyenas are adept at eating their prey in water : they have been observed to dive under floating carcasses to take bites, then resurface to swallow. the spotted hyena is very efficient at eating its prey ; not only is it able to splinter and eat the largest ungulate bones, it is also able to digest them completely. spotted hyenas can digest all organic components in bones, not just the marrow. any inorganic material is excreted with the faeces, which consist almost entirely of a white powder with few hairs. they react to alighting vultures more readily than other african carnivores, and are more likely to stay in the vicinity of lion kills or human settlements. = = references = = = = = bibliography = = = estes, richard ( 1992 ). the behavior
mass migrations take place, or used to take place, by the following mammals : africa : hartebeest springbok black wildebeest blue wildebeest blesbok tiang burchell's zebra quagga ( extinct ) thompson's gazelle mongalla gazelle white - eared kob grant's gazelle scimitar - horned oryx giant eland north america : pronghorn mule deer bison wapiti mexican free - tailed bat north america and eurasia : reindeer / caribou eurasia : siberian roe deer chiru kulan mongolian gazelle saiga of these migrations, those of the springbok, black wildebeest, blesbok, scimitar - horned oryx, and kulan have ceased. = = references = =
includes the cats, dogs, and bears ), 177 are solitary ; and 35 of the 37 wild cats are solitary, including the cougar and cheetah. however, the solitary cougar does allow other cougars to share in a kill, and the coyote can be either solitary or social. other solitary predators include the northern pike, wolf spiders and all the thousands of species of solitary wasps among arthropods, and many microorganisms and zooplankton. = = specialization = = = = = physical adaptations = = = under the pressure of natural selection, predators have evolved a variety of physical adaptations for detecting, catching, killing, and digesting prey. these include speed, agility, stealth, sharp senses, claws, teeth, filters, and suitable digestive systems. for detecting prey, predators have well - developed vision, smell, or hearing. predators as diverse as owls and jumping spiders have forward - facing eyes, providing accurate binocular vision over a relatively narrow field of view, whereas prey animals often have less acute all - round vision. animals such as foxes can smell their prey even when it is concealed under 2 feet ( 60 cm ) of snow or earth. many predators have acute hearing, and some such as echolocating bats hunt exclusively by active or passive use of sound. predators including big cats, birds of prey, and ants share powerful jaws, sharp teeth, or claws which they use to seize and kill their prey. some predators such as snakes and fish - eating birds like herons and cormorants swallow their prey whole ; some snakes can unhinge their jaws to allow them to swallow large prey, while fish - eating birds have long spear - like beaks that they use to stab and grip fast - moving and slippery prey. fish and other predators have developed the ability to crush or open the armoured shells of molluscs. many predators are powerfully built and can catch and kill animals larger than themselves ; this applies as much to small predators such as ants and shrews as to big and visibly muscular carnivores like the cougar and lion. = = = diet and behaviour = = = predators are often highly specialized in their diet and hunting behaviour ; for example, the eurasian lynx only hunts small ungulates. others such as leopards are more opportunistic generalists, preying on at least 100 species. the specialists may be highly adapted to capturing their preferred prey, whereas generalists may be better able to switch to other prey when
Answer:
|
in different habitats
| 0.3 |
We will eventually exhaust our supply of
0. water
1. coal
2. air
3. time
##s to sustain our present level of consumption. environmentally, the world is in an overshoot mode. " as of 2012, the united states alone was using 30 % of the world's resources and if everyone were to consume at that rate, we would need 3 - 5 planets to sustain this type of living. resources are quickly becoming depleted, with about β
already gone. with new consumer markets rising in the developing countries which account for a much higher percentage of the world's population, this number can only rise. according to sierra club β s dave tilford, " with less than 5 percent of world population, the u. s. uses one - third of the world β s paper, a quarter of the world β s oil, 23 percent of the coal, 27 percent of the aluminum, and 19 percent of the copper. " according to bbc, a world bank study has found that " americans produce 16. 5 tonnes of carbon dioxide per capita every year. by comparison, only 0. 1 tonnes of the greenhouse gas is generated in ethiopia per inhabitant. " a 2021 study published in frontiers in conservation science posits that aggregate consumption growth will continue into the near future and perhaps beyond, largely due to increasing affluence and population growth. the authors argue that " there is no way β ethically or otherwise ( barring extreme and unprecedented increases in human mortality ) β to avoid rising human numbers and the accompanying overconsumption ", although they do say that the negative impacts of overconsumption can perhaps be diminished by implementing human rights policies to lower fertility rates and decelerate current consumption patterns. = = = effects on health = = = a report from the lancet commission says the same. the experts write : " until now, undernutrition and obesity have been seen as polar opposites of either too few or too many calories, " " in reality, they are both driven by the same unhealthy, inequitable food systems, underpinned by the same political economy that is single - focused on economic growth, and ignores the negative health and equity outcomes. climate change has the same story of profits and power, ". obesity was a medical problem for people who overconsumed food and worked too little already in ancient rome, and its impact slowly grew through history. as to 2012, mortality from obesity was 3 times larger than from hunger, reaching 2. 8 million people per year by 2017 just as overconsumption of food has led to widespread health crises such as
the release of toxins into the environment, and water scarcity. as of 2019, 85 % of the world's energy needs are met by burning fossil fuels. energy production and consumption are responsible for 76 % of annual human - caused greenhouse gas emissions as of 2018. the 2015 international paris agreement on climate change aims to limit global warming to well below 2 Β°c ( 3. 6 Β°f ) and preferably to 1. 5 Β°c ( 2. 7 Β°f ) ; achieving this goal will require that emissions be reduced as soon as possible and reach net - zero by mid - century. the burning of fossil fuels and biomass is a major source of air pollution, which causes an estimated 7 million deaths each year, with the greatest attributable disease burden seen in low and middle - income countries. fossil - fuel burning in power plants, vehicles, and factories is the main source of emissions that combine with oxygen in the atmosphere to cause acid rain. air pollution is the second - leading cause of death from non - infectious disease. an estimated 99 % of the world's population lives with levels of air pollution that exceed the world health organization recommended limits. cooking with polluting fuels such as wood, animal dung, coal, or kerosene is responsible for nearly all indoor air pollution, which causes an estimated 1. 6 to 3. 8 million deaths annually, and also contributes significantly to outdoor air pollution. health effects are concentrated among women, who are likely to be responsible for cooking, and young children. environmental impacts extend beyond the by - products of combustion. oil spills at sea harm marine life and may cause fires which release toxic emissions. around 10 % of global water use goes to energy production, mainly for cooling in thermal energy plants. in dry regions, this contributes to water scarcity. bioenergy production, coal mining and processing, and oil extraction also require large amounts of water. excessive harvesting of wood and other combustible material for burning can cause serious local environmental damage, including desertification. = = = sustainable development goals = = = meeting existing and future energy demands in a sustainable way is a critical challenge for the global goal of limiting climate change while maintaining economic growth and enabling living standards to rise. reliable and affordable energy, particularly electricity, is essential for health care, education, and economic development. as of 2020, 790 million people in developing countries do not have access to electricity, and around 2. 6 billion rely on burning polluting fuels for cooking. improving energy access in the least - developed countries and making energy cleaner
to a zero - carbon energy system will bring strong co - benefits for human health : the world health organization estimates that efforts to limit global warming to 1. 5 Β°c could save millions of lives each year from reductions to air pollution alone. with good planning and management, pathways exist to provide universal access to electricity and clean cooking by 2030 in ways that are consistent with climate goals. historically, several countries have made rapid economic gains through coal usage. however, there remains a window of opportunity for many poor countries and regions to " leapfrog " fossil fuel dependency by developing their energy systems based on renewables, given adequate international investment and knowledge transfer. = = = integrating variable energy sources = = = to deliver reliable electricity from variable renewable energy sources such as wind and solar, electrical power systems require flexibility. most electrical grids were constructed for non - intermittent energy sources such as coal - fired power plants. as larger amounts of solar and wind energy are integrated into the grid, changes have to be made to the energy system to ensure that the supply of electricity is matched to demand. in 2019, these sources generated 8. 5 % of worldwide electricity, a share that has grown rapidly. there are various ways to make the electricity system more flexible. in many places, wind and solar generation are complementary on a daily and a seasonal scale : there is more wind during the night and in winter when solar energy production is low. linking different geographical regions through long - distance transmission lines allows for further cancelling out of variability. energy demand can be shifted in time through energy demand management and the use of smart grids, matching the times when variable energy production is highest. with grid energy storage, energy produced in excess can be released when needed. further flexibility could be provided from sector coupling, that is coupling the electricity sector to the heat and mobility sector via power - to - heat - systems and electric vehicles. building overcapacity for wind and solar generation can help ensure that enough electricity is produced even during poor weather. in optimal weather, energy generation may have to be curtailed if excess electricity cannot be used or stored. the final demand - supply mismatch may be covered by using dispatchable energy sources such as hydropower, bioenergy, or natural gas. = = = = energy storage = = = = energy storage helps overcome barriers to intermittent renewable energy and is an important aspect of a sustainable energy system. the most commonly used and available storage method is pumped - storage hydroelectricity, which requires locations with large differences in height and access to water.
initial capacity. zero, a british - based company set up by former f1 engineer paddy lowe, has developed a process it terms'petrosynthesis'to develop synthetic fuels from atmospheric carbon dioxide and water using renewable energy. in 2022 it began work on a demonstration production plant at bicester heritage near oxford. commercial developments are taking place in columbia, south carolina, camarillo, california, and darlington, england. a demonstration project in berkeley, california, proposes synthesizing both fuels and food oils from recovered flue gases. = = greenhouse gas remediation = = carbon - neutral fuels can lead to greenhouse gas remediation because carbon dioxide gas would be reused to produce fuel instead of being released into the atmosphere. capturing the carbon dioxide in flue gas emissions from power plants would eliminate their greenhouse gas emissions, although burning the fuel in vehicles would release that carbon because there is no economical way to capture those emissions. this approach would reduce net carbon dioxide emission by about 50 % if it were used on all fossil fuel power plants. most coal and natural gas power plants have been predicted to be economically retrofittable with carbon dioxide scrubbers for carbon capture to recycle flue exhaust or for carbon sequestration. such recycling is expected to not only cost less than the excess economic impacts of climate change if it were not done, but also to pay for itself as global fuel demand growth and peak oil shortages increase the price of petroleum and fungible natural gas. capturing co2 directly from the air, known as direct air capture, or extracting carbonic acid from seawater would also reduce the amount of carbon dioxide in the environment, and create a closed cycle of carbon to eliminate new carbon dioxide emissions. use of these methods would eliminate the need for fossil fuels entirely, assuming that enough renewable energy could be generated to produce the fuel. using synthetic hydrocarbons to produce synthetic materials such as plastics could result in permanent sequestration of carbon from the atmosphere. = = technologies = = = = = traditional fuels, methanol or ethanol = = = some authorities have recommended producing methanol instead of traditional transportation fuels. it is a liquid at normal temperatures and can be toxic if ingested. methanol has a higher octane rating than gasoline but a lower energy density, and can be mixed with other fuels or used on its own. it may also be used in the production of more complex hydrocarbons and polymers. direct methanol fuel cells have been developed by caltech's jet propulsion laboratory to
energy is sustainable if it " meets the needs of the present without compromising the ability of future generations to meet their own needs. " definitions of sustainable energy usually look at its effects on the environment, the economy, and society. these impacts range from greenhouse gas emissions and air pollution to energy poverty and toxic waste. renewable energy sources such as wind, hydro, solar, and geothermal energy can cause environmental damage but are generally far more sustainable than fossil fuel sources. the role of non - renewable energy sources in sustainable energy is controversial. nuclear power does not produce carbon pollution or air pollution, but has drawbacks that include radioactive waste, the risk of nuclear proliferation, and the risk of accidents. switching from coal to natural gas has environmental benefits, including a lower climate impact, but may lead to a delay in switching to more sustainable options. carbon capture and storage can be built into power plants to remove their carbon dioxide ( co2 ) emissions, but this technology is expensive and has rarely been implemented. fossil fuels provide 85 % of the world's energy consumption, and the energy system is responsible for 76 % of global greenhouse gas emissions. around 790 million people in developing countries lack access to electricity, and 2. 6 billion rely on polluting fuels such as wood or charcoal to cook. cooking with biomass plus fossil fuel pollution causes an estimated 7 million deaths each year. limiting global warming to 2 Β°c ( 3. 6 Β°f ) will require transforming energy production, distribution, storage, and consumption. universal access to clean electricity can have major benefits to the climate, human health, and the economies of developing countries. climate change mitigation pathways have been proposed to limit global warming to 2 Β°c ( 3. 6 Β°f ). these include phasing out coal - fired power plants, conserving energy, producing more electricity from clean sources such as wind and solar, and switching from fossil fuels to electricity for transport and heating buildings. power output from some renewable energy sources varies depending on when the wind blows and the sun shines. switching to renewable energy can therefore require electrical grid upgrades, such as the addition of energy storage. some processes that are difficult to electrify can use hydrogen fuel produced from low - emission energy sources. in the international energy agency's proposal for achieving net zero emissions by 2050, about 35 % of the reduction in emissions depends on technologies that are still in development as of 2023. wind and solar market share grew to 8. 5 % of worldwide electricity in 2019, and costs continue to fall. the inter
Answer:
|
coal
| null |
We will eventually exhaust our supply of
0. water
1. coal
2. air
3. time
##s to sustain our present level of consumption. environmentally, the world is in an overshoot mode. " as of 2012, the united states alone was using 30 % of the world's resources and if everyone were to consume at that rate, we would need 3 - 5 planets to sustain this type of living. resources are quickly becoming depleted, with about β
already gone. with new consumer markets rising in the developing countries which account for a much higher percentage of the world's population, this number can only rise. according to sierra club β s dave tilford, " with less than 5 percent of world population, the u. s. uses one - third of the world β s paper, a quarter of the world β s oil, 23 percent of the coal, 27 percent of the aluminum, and 19 percent of the copper. " according to bbc, a world bank study has found that " americans produce 16. 5 tonnes of carbon dioxide per capita every year. by comparison, only 0. 1 tonnes of the greenhouse gas is generated in ethiopia per inhabitant. " a 2021 study published in frontiers in conservation science posits that aggregate consumption growth will continue into the near future and perhaps beyond, largely due to increasing affluence and population growth. the authors argue that " there is no way β ethically or otherwise ( barring extreme and unprecedented increases in human mortality ) β to avoid rising human numbers and the accompanying overconsumption ", although they do say that the negative impacts of overconsumption can perhaps be diminished by implementing human rights policies to lower fertility rates and decelerate current consumption patterns. = = = effects on health = = = a report from the lancet commission says the same. the experts write : " until now, undernutrition and obesity have been seen as polar opposites of either too few or too many calories, " " in reality, they are both driven by the same unhealthy, inequitable food systems, underpinned by the same political economy that is single - focused on economic growth, and ignores the negative health and equity outcomes. climate change has the same story of profits and power, ". obesity was a medical problem for people who overconsumed food and worked too little already in ancient rome, and its impact slowly grew through history. as to 2012, mortality from obesity was 3 times larger than from hunger, reaching 2. 8 million people per year by 2017 just as overconsumption of food has led to widespread health crises such as
the release of toxins into the environment, and water scarcity. as of 2019, 85 % of the world's energy needs are met by burning fossil fuels. energy production and consumption are responsible for 76 % of annual human - caused greenhouse gas emissions as of 2018. the 2015 international paris agreement on climate change aims to limit global warming to well below 2 Β°c ( 3. 6 Β°f ) and preferably to 1. 5 Β°c ( 2. 7 Β°f ) ; achieving this goal will require that emissions be reduced as soon as possible and reach net - zero by mid - century. the burning of fossil fuels and biomass is a major source of air pollution, which causes an estimated 7 million deaths each year, with the greatest attributable disease burden seen in low and middle - income countries. fossil - fuel burning in power plants, vehicles, and factories is the main source of emissions that combine with oxygen in the atmosphere to cause acid rain. air pollution is the second - leading cause of death from non - infectious disease. an estimated 99 % of the world's population lives with levels of air pollution that exceed the world health organization recommended limits. cooking with polluting fuels such as wood, animal dung, coal, or kerosene is responsible for nearly all indoor air pollution, which causes an estimated 1. 6 to 3. 8 million deaths annually, and also contributes significantly to outdoor air pollution. health effects are concentrated among women, who are likely to be responsible for cooking, and young children. environmental impacts extend beyond the by - products of combustion. oil spills at sea harm marine life and may cause fires which release toxic emissions. around 10 % of global water use goes to energy production, mainly for cooling in thermal energy plants. in dry regions, this contributes to water scarcity. bioenergy production, coal mining and processing, and oil extraction also require large amounts of water. excessive harvesting of wood and other combustible material for burning can cause serious local environmental damage, including desertification. = = = sustainable development goals = = = meeting existing and future energy demands in a sustainable way is a critical challenge for the global goal of limiting climate change while maintaining economic growth and enabling living standards to rise. reliable and affordable energy, particularly electricity, is essential for health care, education, and economic development. as of 2020, 790 million people in developing countries do not have access to electricity, and around 2. 6 billion rely on burning polluting fuels for cooking. improving energy access in the least - developed countries and making energy cleaner
to a zero - carbon energy system will bring strong co - benefits for human health : the world health organization estimates that efforts to limit global warming to 1. 5 Β°c could save millions of lives each year from reductions to air pollution alone. with good planning and management, pathways exist to provide universal access to electricity and clean cooking by 2030 in ways that are consistent with climate goals. historically, several countries have made rapid economic gains through coal usage. however, there remains a window of opportunity for many poor countries and regions to " leapfrog " fossil fuel dependency by developing their energy systems based on renewables, given adequate international investment and knowledge transfer. = = = integrating variable energy sources = = = to deliver reliable electricity from variable renewable energy sources such as wind and solar, electrical power systems require flexibility. most electrical grids were constructed for non - intermittent energy sources such as coal - fired power plants. as larger amounts of solar and wind energy are integrated into the grid, changes have to be made to the energy system to ensure that the supply of electricity is matched to demand. in 2019, these sources generated 8. 5 % of worldwide electricity, a share that has grown rapidly. there are various ways to make the electricity system more flexible. in many places, wind and solar generation are complementary on a daily and a seasonal scale : there is more wind during the night and in winter when solar energy production is low. linking different geographical regions through long - distance transmission lines allows for further cancelling out of variability. energy demand can be shifted in time through energy demand management and the use of smart grids, matching the times when variable energy production is highest. with grid energy storage, energy produced in excess can be released when needed. further flexibility could be provided from sector coupling, that is coupling the electricity sector to the heat and mobility sector via power - to - heat - systems and electric vehicles. building overcapacity for wind and solar generation can help ensure that enough electricity is produced even during poor weather. in optimal weather, energy generation may have to be curtailed if excess electricity cannot be used or stored. the final demand - supply mismatch may be covered by using dispatchable energy sources such as hydropower, bioenergy, or natural gas. = = = = energy storage = = = = energy storage helps overcome barriers to intermittent renewable energy and is an important aspect of a sustainable energy system. the most commonly used and available storage method is pumped - storage hydroelectricity, which requires locations with large differences in height and access to water.
initial capacity. zero, a british - based company set up by former f1 engineer paddy lowe, has developed a process it terms'petrosynthesis'to develop synthetic fuels from atmospheric carbon dioxide and water using renewable energy. in 2022 it began work on a demonstration production plant at bicester heritage near oxford. commercial developments are taking place in columbia, south carolina, camarillo, california, and darlington, england. a demonstration project in berkeley, california, proposes synthesizing both fuels and food oils from recovered flue gases. = = greenhouse gas remediation = = carbon - neutral fuels can lead to greenhouse gas remediation because carbon dioxide gas would be reused to produce fuel instead of being released into the atmosphere. capturing the carbon dioxide in flue gas emissions from power plants would eliminate their greenhouse gas emissions, although burning the fuel in vehicles would release that carbon because there is no economical way to capture those emissions. this approach would reduce net carbon dioxide emission by about 50 % if it were used on all fossil fuel power plants. most coal and natural gas power plants have been predicted to be economically retrofittable with carbon dioxide scrubbers for carbon capture to recycle flue exhaust or for carbon sequestration. such recycling is expected to not only cost less than the excess economic impacts of climate change if it were not done, but also to pay for itself as global fuel demand growth and peak oil shortages increase the price of petroleum and fungible natural gas. capturing co2 directly from the air, known as direct air capture, or extracting carbonic acid from seawater would also reduce the amount of carbon dioxide in the environment, and create a closed cycle of carbon to eliminate new carbon dioxide emissions. use of these methods would eliminate the need for fossil fuels entirely, assuming that enough renewable energy could be generated to produce the fuel. using synthetic hydrocarbons to produce synthetic materials such as plastics could result in permanent sequestration of carbon from the atmosphere. = = technologies = = = = = traditional fuels, methanol or ethanol = = = some authorities have recommended producing methanol instead of traditional transportation fuels. it is a liquid at normal temperatures and can be toxic if ingested. methanol has a higher octane rating than gasoline but a lower energy density, and can be mixed with other fuels or used on its own. it may also be used in the production of more complex hydrocarbons and polymers. direct methanol fuel cells have been developed by caltech's jet propulsion laboratory to
energy is sustainable if it " meets the needs of the present without compromising the ability of future generations to meet their own needs. " definitions of sustainable energy usually look at its effects on the environment, the economy, and society. these impacts range from greenhouse gas emissions and air pollution to energy poverty and toxic waste. renewable energy sources such as wind, hydro, solar, and geothermal energy can cause environmental damage but are generally far more sustainable than fossil fuel sources. the role of non - renewable energy sources in sustainable energy is controversial. nuclear power does not produce carbon pollution or air pollution, but has drawbacks that include radioactive waste, the risk of nuclear proliferation, and the risk of accidents. switching from coal to natural gas has environmental benefits, including a lower climate impact, but may lead to a delay in switching to more sustainable options. carbon capture and storage can be built into power plants to remove their carbon dioxide ( co2 ) emissions, but this technology is expensive and has rarely been implemented. fossil fuels provide 85 % of the world's energy consumption, and the energy system is responsible for 76 % of global greenhouse gas emissions. around 790 million people in developing countries lack access to electricity, and 2. 6 billion rely on polluting fuels such as wood or charcoal to cook. cooking with biomass plus fossil fuel pollution causes an estimated 7 million deaths each year. limiting global warming to 2 Β°c ( 3. 6 Β°f ) will require transforming energy production, distribution, storage, and consumption. universal access to clean electricity can have major benefits to the climate, human health, and the economies of developing countries. climate change mitigation pathways have been proposed to limit global warming to 2 Β°c ( 3. 6 Β°f ). these include phasing out coal - fired power plants, conserving energy, producing more electricity from clean sources such as wind and solar, and switching from fossil fuels to electricity for transport and heating buildings. power output from some renewable energy sources varies depending on when the wind blows and the sun shines. switching to renewable energy can therefore require electrical grid upgrades, such as the addition of energy storage. some processes that are difficult to electrify can use hydrogen fuel produced from low - emission energy sources. in the international energy agency's proposal for achieving net zero emissions by 2050, about 35 % of the reduction in emissions depends on technologies that are still in development as of 2023. wind and solar market share grew to 8. 5 % of worldwide electricity in 2019, and costs continue to fall. the inter
Answer:
|
time
| 0.3 |
Which organism would eat fish and live in marshland?
0. a tree
1. a whale
2. a warthog
3. an alligator
ocean currents. the most abundant zooplankton species are copepods and krill : tiny crustaceans that are the most numerous animals on earth. other types of zooplankton include jelly fish and the larvae of fish, marine worms, starfish, and other marine organisms ". in turn, the zooplankton are eaten by filter - feeding animals, including some seabirds, small forage fish like herrings and sardines, whale sharks, manta rays, and the largest animal in the world, the blue whale. yet again, moving up the foodchain, the small forage fish are in turn eaten by larger predators, such as tuna, marlin, sharks, large squid, seabirds, dolphins, and toothed whales. = = open ocean = = the open ocean is relatively unproductive because of a lack of nutrients, yet because it is so vast, it has more overall primary production than any other marine habitat. only about 10 percent of marine species live in the open ocean. but among them are the largest and fastest of all marine animals, as well as the animals that dive the deepest and migrate the longest. in the depths lurk animal that, to our eyes, appear hugely alien. = = = deep sea = = = the deep sea starts at the aphotic zone, the point where sunlight loses most of its energy in the water. many life forms that live at these depths have the ability to create their own light a unique evolution known as bio - luminescence. in the deep ocean, the waters extend far below the epipelagic zone, and support very different types of pelagic life forms adapted to living in these deeper zones. much of the aphotic zone's energy is supplied by the open ocean in the form of detritus. in deep water, marine snow is a continuous shower of mostly organic detritus falling from the upper layers of the water column. its origin lies in activities within the productive photic zone. marine snow includes dead or dying plankton, protists ( diatoms ), fecal matter, sand, soot and other inorganic dust. the " snowflakes " grow over time and may reach several centimetres in diameter, travelling for weeks before reaching the ocean floor. however, most organic components of marine snow are consumed by microbes, zooplankton and other filter - feeding animals within the first 1, 000 metres of their journey, that is, within the ep
. herbivores, as primary consumers, eat the plant material directly to digest and absorb the nutrients, while carnivores and other animals on higher trophic levels indirectly acquire the nutrients by eating the herbivores or other animals that have eaten the herbivores. animals oxidise carbohydrates, lipids, proteins and other biomolecules, which allows the animal to grow and to sustain basal metabolism and fuel other biological processes such as locomotion. some benthic animals living close to hydrothermal vents and cold seeps on the dark sea floor consume organic matter produced through chemosynthesis ( via oxidising inorganic compounds such as hydrogen sulfide ) by archaea and bacteria. animals evolved in the sea. lineages of arthropods colonised land around the same time as land plants, probably between 510 and 471 million years ago during the late cambrian or early ordovician. vertebrates such as the lobe - finned fish tiktaalik started to move on to land in the late devonian, about 375 million years ago. animals occupy virtually all of earth's habitats and microhabitats, with faunas adapted to salt water, hydrothermal vents, fresh water, hot springs, swamps, forests, pastures, deserts, air, and the interiors of other organisms. animals are however not particularly heat tolerant ; very few of them can survive at constant temperatures above 50 Β°c ( 122 Β°f ) or in the most extreme cold deserts of continental antarctica. the collective global geomorphic influence of animals on the processes shaping the earth's surface remains largely understudied, with most studies limited to individual species and well - known exemplars. = = diversity = = = = = size = = = the blue whale ( balaenoptera musculus ) is the largest animal that has ever lived, weighing up to 190 tonnes and measuring up to 33. 6 metres ( 110 ft ) long. the largest extant terrestrial animal is the african bush elephant ( loxodonta africana ), weighing up to 12. 25 tonnes and measuring up to 10. 67 metres ( 35. 0 ft ) long. the largest terrestrial animals that ever lived were titanosaur sauropod dinosaurs such as argentinosaurus, which may have weighed as much as 73 tonnes, and supersaurus which may have reached 39 metres. several animals are microscopic ; some myxozoa ( obligate parasites within the cnidaria ) never grow larger than 20 ΞΌm
juvenile fish grow with great rapidity when the conditions are right, but the whole population of fish may end up as eggs in diapause in the dried up mud that was once a pond. = = = = examples of wetland and riparian habitat types = = = = bog marsh fen flooded grasslands and savannas floodplain shrub swamp swamp vernal pool wet meadow = = = forest = = = = = = = examples of forest habitat types = = = = boreal forest cloud forest peat swamp forest temperate coniferous forest temperate deciduous forest temperate rain forest thorn forest tropical dry forest tropical moist forest tropical rain forest woodland = = = freshwater = = = freshwater habitat types include rivers, streams, lakes, ponds, marshes and bogs. they can be divided into running waters ( rivers, streams ) and standing waters ( lakes, ponds, marshes, bogs ). although some organisms are found across most of these habitat types, the majority have more specific requirements. the water velocity, its temperature and oxygen saturation are important factors, but in river systems, there are fast and slow sections, pools, bayous and backwaters which provide a range of habitat types. similarly, aquatic plants can be floating, semi - submerged, submerged or grow in permanently or temporarily saturated soils besides bodies of water. marginal plants provide important habitat for both invertebrates and vertebrates, and submerged plants provide oxygenation of the water, absorb nutrients and play a part in the reduction of pollution. = = = marine = = = marine habitats include brackish water, estuaries, bays, the open sea, the intertidal zone, the sea bed, reefs and deep / shallow water zones. further variations include rock pools, sand banks, mudflats, brackish lagoons, sandy and pebbly beaches, and seagrass beds, all supporting their own flora and fauna. the benthic zone or seabed provides a home for both static organisms, anchored to the substrate, and for a large range of organisms crawling on or burrowing into the surface. some creatures float among the waves on the surface of the water, or raft on floating debris, others swim at a range of depths, including organisms in the demersal zone close to the seabed, and myriads of organisms drift with the currents and form the plankton. = = = = list of marine habitat types = = = = = = = urban = = = many animals and plants have taken up residence in urban environments. they tend to be adaptable generalists and use the
snakehead goby = = = crustacean = = = crayfish freshwater prawn = = = snails = = = river snail small aquatic snails are usually found in ponds that contain plants. some people purchase apple snails to keep in their water garden. " melantho snails " of the genus lymnaea are also used. = = = herpetofauna = = = ponds located in suburban and rural areas often attract amphibians such as common frogs and fire salamanders and reptiles such as turtles, lizards, and snakes. = = = bird = = = wild duck domestic duck = = = predators = = = garden ponds can attract attention from predators such as ( in north america ) raccoons, herons, snakes, and domestic cats. these predators can be a danger to fish. owners of koi are often particularly careful to create protected areas as some varieties are very expensive. = = see also = = list of garden types landscape architecture aquascaping, arranging plants in an aquarium rain garden biochemical oxygen demand chemical oxygen demand wastewater quality indicators biotope aquaponics = = = index categories = = = category : natural pools = = references = = = = external links = = dugout pond aeration flash animation north american water garden society pond conservation : advice on garden ponds for wildlife
layer, plant layer, leaf litter, and soil ; buttress root, stump, fallen log, stem base, grass tussock, fungus, fern, and moss. the greater the structural diversity in the wood, the greater the number of microhabitat types that will be present. a range of tree species with individual specimens of varying sizes and ages, and a range of features such as streams, level areas, slopes, tracks, clearings, and felled areas will provide suitable conditions for an enormous number of biodiverse plants and animals. for example, in britain it has been estimated that various types of rotting wood are home to over 1700 species of invertebrate. for a parasitic organism, its habitat is the particular part of the outside or inside of its host on or in which it is adapted to live. the life cycle of some parasites involves several different host species, as well as free - living life stages, sometimes within vastly different microhabitat types. one such organism is the trematode ( flatworm ) microphallus turgidus, present in brackish water marshes in the southeastern united states. its first intermediate host is a snail and the second, a glass shrimp. the final host is the waterfowl or mammal that consumes the shrimp. = = extreme habitat types = = although the vast majority of life on earth lives in mesophyllic ( moderate ) environments, a few organisms, most of them microbes, have managed to colonise extreme environments that are unsuitable for more complex life forms. there are bacteria, for example, living in lake whillans, half a mile below the ice of antarctica ; in the absence of sunlight, they must rely on organic material from elsewhere, perhaps decaying matter from glacier melt water or minerals from the underlying rock. other bacteria can be found in abundance in the mariana trench, the deepest place in the ocean and on earth ; marine snow drifts down from the surface layers of the sea and accumulates in this undersea valley, providing nourishment for an extensive community of bacteria. other microbes live in environments lacking in oxygen, and are dependent on chemical reactions other than photosynthesis. boreholes drilled 300 m ( 1, 000 ft ) into the rocky seabed have found microbial communities apparently based on the products of reactions between water and the constituents of rocks. these communities have not been studied much, but may be an important part of the global carbon cycle. rock in mines two miles deep also harbour microbes ;
Answer:
|
an alligator
| null |
Which organism would eat fish and live in marshland?
0. a tree
1. a whale
2. a warthog
3. an alligator
ocean currents. the most abundant zooplankton species are copepods and krill : tiny crustaceans that are the most numerous animals on earth. other types of zooplankton include jelly fish and the larvae of fish, marine worms, starfish, and other marine organisms ". in turn, the zooplankton are eaten by filter - feeding animals, including some seabirds, small forage fish like herrings and sardines, whale sharks, manta rays, and the largest animal in the world, the blue whale. yet again, moving up the foodchain, the small forage fish are in turn eaten by larger predators, such as tuna, marlin, sharks, large squid, seabirds, dolphins, and toothed whales. = = open ocean = = the open ocean is relatively unproductive because of a lack of nutrients, yet because it is so vast, it has more overall primary production than any other marine habitat. only about 10 percent of marine species live in the open ocean. but among them are the largest and fastest of all marine animals, as well as the animals that dive the deepest and migrate the longest. in the depths lurk animal that, to our eyes, appear hugely alien. = = = deep sea = = = the deep sea starts at the aphotic zone, the point where sunlight loses most of its energy in the water. many life forms that live at these depths have the ability to create their own light a unique evolution known as bio - luminescence. in the deep ocean, the waters extend far below the epipelagic zone, and support very different types of pelagic life forms adapted to living in these deeper zones. much of the aphotic zone's energy is supplied by the open ocean in the form of detritus. in deep water, marine snow is a continuous shower of mostly organic detritus falling from the upper layers of the water column. its origin lies in activities within the productive photic zone. marine snow includes dead or dying plankton, protists ( diatoms ), fecal matter, sand, soot and other inorganic dust. the " snowflakes " grow over time and may reach several centimetres in diameter, travelling for weeks before reaching the ocean floor. however, most organic components of marine snow are consumed by microbes, zooplankton and other filter - feeding animals within the first 1, 000 metres of their journey, that is, within the ep
. herbivores, as primary consumers, eat the plant material directly to digest and absorb the nutrients, while carnivores and other animals on higher trophic levels indirectly acquire the nutrients by eating the herbivores or other animals that have eaten the herbivores. animals oxidise carbohydrates, lipids, proteins and other biomolecules, which allows the animal to grow and to sustain basal metabolism and fuel other biological processes such as locomotion. some benthic animals living close to hydrothermal vents and cold seeps on the dark sea floor consume organic matter produced through chemosynthesis ( via oxidising inorganic compounds such as hydrogen sulfide ) by archaea and bacteria. animals evolved in the sea. lineages of arthropods colonised land around the same time as land plants, probably between 510 and 471 million years ago during the late cambrian or early ordovician. vertebrates such as the lobe - finned fish tiktaalik started to move on to land in the late devonian, about 375 million years ago. animals occupy virtually all of earth's habitats and microhabitats, with faunas adapted to salt water, hydrothermal vents, fresh water, hot springs, swamps, forests, pastures, deserts, air, and the interiors of other organisms. animals are however not particularly heat tolerant ; very few of them can survive at constant temperatures above 50 Β°c ( 122 Β°f ) or in the most extreme cold deserts of continental antarctica. the collective global geomorphic influence of animals on the processes shaping the earth's surface remains largely understudied, with most studies limited to individual species and well - known exemplars. = = diversity = = = = = size = = = the blue whale ( balaenoptera musculus ) is the largest animal that has ever lived, weighing up to 190 tonnes and measuring up to 33. 6 metres ( 110 ft ) long. the largest extant terrestrial animal is the african bush elephant ( loxodonta africana ), weighing up to 12. 25 tonnes and measuring up to 10. 67 metres ( 35. 0 ft ) long. the largest terrestrial animals that ever lived were titanosaur sauropod dinosaurs such as argentinosaurus, which may have weighed as much as 73 tonnes, and supersaurus which may have reached 39 metres. several animals are microscopic ; some myxozoa ( obligate parasites within the cnidaria ) never grow larger than 20 ΞΌm
juvenile fish grow with great rapidity when the conditions are right, but the whole population of fish may end up as eggs in diapause in the dried up mud that was once a pond. = = = = examples of wetland and riparian habitat types = = = = bog marsh fen flooded grasslands and savannas floodplain shrub swamp swamp vernal pool wet meadow = = = forest = = = = = = = examples of forest habitat types = = = = boreal forest cloud forest peat swamp forest temperate coniferous forest temperate deciduous forest temperate rain forest thorn forest tropical dry forest tropical moist forest tropical rain forest woodland = = = freshwater = = = freshwater habitat types include rivers, streams, lakes, ponds, marshes and bogs. they can be divided into running waters ( rivers, streams ) and standing waters ( lakes, ponds, marshes, bogs ). although some organisms are found across most of these habitat types, the majority have more specific requirements. the water velocity, its temperature and oxygen saturation are important factors, but in river systems, there are fast and slow sections, pools, bayous and backwaters which provide a range of habitat types. similarly, aquatic plants can be floating, semi - submerged, submerged or grow in permanently or temporarily saturated soils besides bodies of water. marginal plants provide important habitat for both invertebrates and vertebrates, and submerged plants provide oxygenation of the water, absorb nutrients and play a part in the reduction of pollution. = = = marine = = = marine habitats include brackish water, estuaries, bays, the open sea, the intertidal zone, the sea bed, reefs and deep / shallow water zones. further variations include rock pools, sand banks, mudflats, brackish lagoons, sandy and pebbly beaches, and seagrass beds, all supporting their own flora and fauna. the benthic zone or seabed provides a home for both static organisms, anchored to the substrate, and for a large range of organisms crawling on or burrowing into the surface. some creatures float among the waves on the surface of the water, or raft on floating debris, others swim at a range of depths, including organisms in the demersal zone close to the seabed, and myriads of organisms drift with the currents and form the plankton. = = = = list of marine habitat types = = = = = = = urban = = = many animals and plants have taken up residence in urban environments. they tend to be adaptable generalists and use the
snakehead goby = = = crustacean = = = crayfish freshwater prawn = = = snails = = = river snail small aquatic snails are usually found in ponds that contain plants. some people purchase apple snails to keep in their water garden. " melantho snails " of the genus lymnaea are also used. = = = herpetofauna = = = ponds located in suburban and rural areas often attract amphibians such as common frogs and fire salamanders and reptiles such as turtles, lizards, and snakes. = = = bird = = = wild duck domestic duck = = = predators = = = garden ponds can attract attention from predators such as ( in north america ) raccoons, herons, snakes, and domestic cats. these predators can be a danger to fish. owners of koi are often particularly careful to create protected areas as some varieties are very expensive. = = see also = = list of garden types landscape architecture aquascaping, arranging plants in an aquarium rain garden biochemical oxygen demand chemical oxygen demand wastewater quality indicators biotope aquaponics = = = index categories = = = category : natural pools = = references = = = = external links = = dugout pond aeration flash animation north american water garden society pond conservation : advice on garden ponds for wildlife
layer, plant layer, leaf litter, and soil ; buttress root, stump, fallen log, stem base, grass tussock, fungus, fern, and moss. the greater the structural diversity in the wood, the greater the number of microhabitat types that will be present. a range of tree species with individual specimens of varying sizes and ages, and a range of features such as streams, level areas, slopes, tracks, clearings, and felled areas will provide suitable conditions for an enormous number of biodiverse plants and animals. for example, in britain it has been estimated that various types of rotting wood are home to over 1700 species of invertebrate. for a parasitic organism, its habitat is the particular part of the outside or inside of its host on or in which it is adapted to live. the life cycle of some parasites involves several different host species, as well as free - living life stages, sometimes within vastly different microhabitat types. one such organism is the trematode ( flatworm ) microphallus turgidus, present in brackish water marshes in the southeastern united states. its first intermediate host is a snail and the second, a glass shrimp. the final host is the waterfowl or mammal that consumes the shrimp. = = extreme habitat types = = although the vast majority of life on earth lives in mesophyllic ( moderate ) environments, a few organisms, most of them microbes, have managed to colonise extreme environments that are unsuitable for more complex life forms. there are bacteria, for example, living in lake whillans, half a mile below the ice of antarctica ; in the absence of sunlight, they must rely on organic material from elsewhere, perhaps decaying matter from glacier melt water or minerals from the underlying rock. other bacteria can be found in abundance in the mariana trench, the deepest place in the ocean and on earth ; marine snow drifts down from the surface layers of the sea and accumulates in this undersea valley, providing nourishment for an extensive community of bacteria. other microbes live in environments lacking in oxygen, and are dependent on chemical reactions other than photosynthesis. boreholes drilled 300 m ( 1, 000 ft ) into the rocky seabed have found microbial communities apparently based on the products of reactions between water and the constituents of rocks. these communities have not been studied much, but may be an important part of the global carbon cycle. rock in mines two miles deep also harbour microbes ;
Answer:
|
a whale
| 0.3 |
Without photosynthesis, animals that rely on plants for this would be out of luck.
0. selling food
1. nothing
2. kissing
3. sustenance
fewer tertiary consumers than there are producers. = = primary production = = a producer is any organism that performs photosynthesis. producers are important because they convert energy from the sun into a storable and usable chemical form of energy, glucose, as well as oxygen. the producers themselves can use the energy stored in glucose to perform cellular respiration. or, if the producer is consumed by herbivores in the next trophic level, some of the energy is passed on up the pyramid. the glucose stored within producers serves as food for consumers, and so it is only through producers that consumers are able to access the sun β s energy. some examples of primary producers are algae, mosses, and other plants such as grasses, trees, and shrubs. chemosynthetic bacteria perform a process similar to photosynthesis, but instead of energy from the sun they use energy stored in chemicals like hydrogen sulfide. this process, referred to as chemosynthesis, usually occurs deep in the ocean at hydrothermal vents that produce heat and chemicals such as hydrogen, hydrogen sulfide and methane. chemosynthetic bacteria can use the energy in the bonds of the hydrogen sulfide and oxygen to convert carbon dioxide to glucose, releasing water and sulfur in the process. organisms that consume the chemosynthetic bacteria can take in the glucose and use oxygen to perform cellular respiration, similar to herbivores consuming producers. one of the factors that controls primary production is the amount of energy that enters the producer ( s ), which can be measured using productivity. only one percent of solar energy enters the producer, the rest bounces off or moves through. gross primary productivity is the amount of energy the producer actually gets. generally, 60 % of the energy that enters the producer goes to the producer β s own respiration. the net primary productivity is the amount that the plant retains after the amount that it used for cellular respiration is subtracted. another factor controlling primary production is organic / inorganic nutrient levels in the water or soil that the producer is living in. an example of the nutrients that can impact the efficiency of primary plant production are nitrogen ( n ) and phosphorus ( p ). = = = carnivorous plants = = = when it comes to dealing with environments that have low nutrient availability, some plants have developed unique ways to adapt to be able to perform photosynthesis. in order to do so, these plants have evolved to be able to obtain important nutrients such as nitrogen from other organisms, just as heterotrophs
anoxic atmosphere, which as a result is now 21 % oxygen. animals and most other organisms are aerobic, relying on oxygen ; those that do not are confined to relatively rare anaerobic environments. plants are the primary producers in most terrestrial ecosystems and form the basis of the food web in those ecosystems. plants form about 80 % of the world biomass at about 450 gigatonnes ( 4. 4Γ1011 long tons ; 5. 0Γ1011 short tons ) of carbon. = = = ecological relationships = = = numerous animals have coevolved with plants ; flowering plants have evolved pollination syndromes, suites of flower traits that favour their reproduction. many, including insect and bird partners, are pollinators, visiting flowers and accidentally transferring pollen in exchange for food in the form of pollen or nectar. many animals disperse seeds that are adapted for such dispersal. various mechanisms of dispersal have evolved. some fruits offer nutritious outer layers attractive to animals, while the seeds are adapted to survive the passage through the animal's gut ; others have hooks that enable them to attach to a mammal's fur. myrmecophytes are plants that have coevolved with ants. the plant provides a home, and sometimes food, for the ants. in exchange, the ants defend the plant from herbivores and sometimes competing plants. ant wastes serve as organic fertilizer. the majority of plant species have fungi associated with their root systems in a mutualistic symbiosis known as mycorrhiza. the fungi help the plants gain water and mineral nutrients from the soil, while the plant gives the fungi carbohydrates manufactured in photosynthesis. some plants serve as homes for endophytic fungi that protect the plant from herbivores by producing toxins. the fungal endophyte neotyphodium coenophialum in tall fescue grass has pest status in the american cattle industry. many legumes have rhizobium nitrogen - fixing bacteria in nodules of their roots, which fix nitrogen from the air for the plant to use ; in return, the plants supply sugars to the bacteria. nitrogen fixed in this way can become available to other plants, and is important in agriculture ; for example, farmers may grow a crop rotation of a legume such as beans, followed by a cereal such as wheat, to provide cash crops with a reduced input of nitrogen fertilizer. some 1 % of plants are parasitic. they range from the semi
zone of the gulf of maine, us. in most cases, facilitation and competition are inversely proportional. studies suggest that facilitation events in nature are rare compared to competition events and thus, competition is a greater driver for ecological processes. = = = improved resource availability = = = facilitation can increase access to limiting resources such as light, water, and nutrients for interacting species. for example, epiphytic plants often receive more direct sunlight in the canopies of their host plants than they would on the ground. also, nurse plants increase the amount of water available to seedlings in dry habitats because of reduced evapotranspiration beneath the shade of nurse plant canopies. a special case concerns human facilitation of sap - feeding birds. three african bird species ( village weaver ploceus cucullatus, common bulbul pycnonotus barbatus, and mouse β brown sunbird anthreptes gabonicus ) regularly feed on the sap flowing from holes made by local wine tappers in oil β palm trees elaies guineensis in the bijagos archipelago, guinea β bissau. however, the most familiar examples of increased access to resources through facilitation are the mutualistic transfers of nutrients between symbiotic organisms. a symbiosis is a prolonged, close association between organisms, and some examples of mutualistic symbioses include : gut flora associations between a host species and a microbe living in the host's digestive tract, wherein the host provides habitat and nourishment to the microbe in exchange for digestive services. for example, termites receive nourishment from cellulose digested by microbes inhabiting their gut. lichens associations between fungi and algae, wherein the fungus receives nutrients from the alga, and the alga is protected from harsh conditions causing desiccation. corals associations between reef - building corals and photosynthetic algae called zooxanthellae, wherein the zooxanthellae provide nutrition to the corals in the form of photosynthate, in exchange for nitrogen in coral waste products. mycorrhizae associations between fungi and plant roots, wherein the fungus facilitates nutrient uptake ( particularly nitrogen ) by the plant in exchange for carbon in the form of sugars from the plant root. there is a parallel example in marine environments of sponges on the roots of mangroves, with a relationship analogous to
, and photoperiodism. photosynthesis provides the energy required to produce the energy source of plants. phototropism is the effect of light on plant growth that causes the plant to grow toward or away from the light. photoperiodism is a plant's response or capacity to respond to photoperiod, a recurring cycle of light and dark periods of constant length. = = = sunlight = = = while sunlight is not always easily controlled by the gardener, it is an important element of garden design. the amount of available light is a critical factor in determining what plants may be grown. sunlight will, therefore, have a substantial influence on the character of the garden. for example, a rose garden is generally not successful in full shade, while a garden of hostas may not thrive in hot sun. as another example, a vegetable garden may need to be placed in a sunny location, and if that location is not ideal for the overall garden design goals, the designer may need to change other aspects of the garden. in some cases, the amount of available sunlight can be influenced by the gardener. the location of trees, other shade plants, garden structures, or, when designing an entire property, even buildings, might be selected or changed based on their influence in increasing or reducing the amount of sunlight provided to various areas of the property. in other cases, the amount of sunlight is not under the gardener's control. nearby buildings, plants on other properties, or simply the climate of the local area, may limit the available sunlight. or, substantial changes in the light conditions of the garden may not be within the gardener's means. in this case, it is important to plan a garden that is compatible with the existing light conditions. = = notable garden designers = = = = types of gardens = = = = = islamic gardens = = = garden design and the islamic garden tradition began with creating the paradise garden in ancient persia, in western asia. it evolved over the centuries, and in the different cultures islamic dynasties came to rule in asia, the near east, north africa, and the iberian peninsula. = = = = examples = = = = some styles and examples include : persian gardens eram garden fin garden mughal gardens nishat bagh shalimar gardens ( lahore ) yadavindra gardens ( pinjore ) charbagh taj mahal tomb of humayun gardens bagh ( garden ) bagh - e babur shalimar bagh ( srinagar ) al - andal
even when significant drawbacks are prevalent. these drawbacks faced by consumers include elevated costs of organic foods, imbalanced monetary price differentials between animal - intensive diets and plant - based alternatives, and an absence of comprehensive consumer guidance aligned with contemporary valuations. in 2020, an analysis of external climate costs of foods indicated that external greenhouse gas costs are typically highest for animal - based products β conventional and organic to about the same extent within that ecosystem subdomain β followed by conventional dairy products and lowest for organic plant - based foods. it finds contemporary monetary evaluations to be " inadequate " and policy - making that lead to reductions of these costs to be possible, appropriate and urgent. = = = agricultural pollution = = = = = sourcing sustainable food = = at the global level the environmental impact of agribusiness is being addressed through sustainable agriculture, cellular agriculture and organic farming. various alternatives to meat and novel classes of foods can substantially increase sustainability. there are large potential benefits of marine algae - based aquaculture for the development of a future healthy and sustainable food system. fungiculture, another sector of a growing bioeconomy besides algaculture, may also become a larger component of a sustainable food system. consumption shares of various other ingredients for meat analogues such as protein from pulses may also rise substantially in a sustainable food system. the integration of single - cell protein, which can be produced from captured co2. optimized dietary scenarios would also see changes in various other types of foods such as nuts, as well as pulses such as beans, which have favorable environmental and health profiles. complementary approaches under development include vertical farming of various types of foods and various agricultural technologies, often using digital agriculture. = = = sustainable seafood = = = sustainable seafood is seafood from either fished or farmed sources that can maintain or increase production in the future without jeopardizing the ecosystems from which it was acquired. the sustainable seafood movement has gained momentum as more people become aware about both overfishing and environmentally destructive fishing methods. the goal of sustainable seafood practices is to ensure that fish populations are able to continue to thrive, that marine habitats are protected, and that fishing and aquaculture practices do not have negative impacts on local communities or economies. there are several factors that go into determining whether a seafood product is sustainable or not. these include the method of fishing or farming, the health of the fish population, the impact on the surrounding environment, and the social and economic implications of the seafood production. some sustainable seafood practices include using methods that minimize
Answer:
|
sustenance
| null |
Without photosynthesis, animals that rely on plants for this would be out of luck.
0. selling food
1. nothing
2. kissing
3. sustenance
fewer tertiary consumers than there are producers. = = primary production = = a producer is any organism that performs photosynthesis. producers are important because they convert energy from the sun into a storable and usable chemical form of energy, glucose, as well as oxygen. the producers themselves can use the energy stored in glucose to perform cellular respiration. or, if the producer is consumed by herbivores in the next trophic level, some of the energy is passed on up the pyramid. the glucose stored within producers serves as food for consumers, and so it is only through producers that consumers are able to access the sun β s energy. some examples of primary producers are algae, mosses, and other plants such as grasses, trees, and shrubs. chemosynthetic bacteria perform a process similar to photosynthesis, but instead of energy from the sun they use energy stored in chemicals like hydrogen sulfide. this process, referred to as chemosynthesis, usually occurs deep in the ocean at hydrothermal vents that produce heat and chemicals such as hydrogen, hydrogen sulfide and methane. chemosynthetic bacteria can use the energy in the bonds of the hydrogen sulfide and oxygen to convert carbon dioxide to glucose, releasing water and sulfur in the process. organisms that consume the chemosynthetic bacteria can take in the glucose and use oxygen to perform cellular respiration, similar to herbivores consuming producers. one of the factors that controls primary production is the amount of energy that enters the producer ( s ), which can be measured using productivity. only one percent of solar energy enters the producer, the rest bounces off or moves through. gross primary productivity is the amount of energy the producer actually gets. generally, 60 % of the energy that enters the producer goes to the producer β s own respiration. the net primary productivity is the amount that the plant retains after the amount that it used for cellular respiration is subtracted. another factor controlling primary production is organic / inorganic nutrient levels in the water or soil that the producer is living in. an example of the nutrients that can impact the efficiency of primary plant production are nitrogen ( n ) and phosphorus ( p ). = = = carnivorous plants = = = when it comes to dealing with environments that have low nutrient availability, some plants have developed unique ways to adapt to be able to perform photosynthesis. in order to do so, these plants have evolved to be able to obtain important nutrients such as nitrogen from other organisms, just as heterotrophs
anoxic atmosphere, which as a result is now 21 % oxygen. animals and most other organisms are aerobic, relying on oxygen ; those that do not are confined to relatively rare anaerobic environments. plants are the primary producers in most terrestrial ecosystems and form the basis of the food web in those ecosystems. plants form about 80 % of the world biomass at about 450 gigatonnes ( 4. 4Γ1011 long tons ; 5. 0Γ1011 short tons ) of carbon. = = = ecological relationships = = = numerous animals have coevolved with plants ; flowering plants have evolved pollination syndromes, suites of flower traits that favour their reproduction. many, including insect and bird partners, are pollinators, visiting flowers and accidentally transferring pollen in exchange for food in the form of pollen or nectar. many animals disperse seeds that are adapted for such dispersal. various mechanisms of dispersal have evolved. some fruits offer nutritious outer layers attractive to animals, while the seeds are adapted to survive the passage through the animal's gut ; others have hooks that enable them to attach to a mammal's fur. myrmecophytes are plants that have coevolved with ants. the plant provides a home, and sometimes food, for the ants. in exchange, the ants defend the plant from herbivores and sometimes competing plants. ant wastes serve as organic fertilizer. the majority of plant species have fungi associated with their root systems in a mutualistic symbiosis known as mycorrhiza. the fungi help the plants gain water and mineral nutrients from the soil, while the plant gives the fungi carbohydrates manufactured in photosynthesis. some plants serve as homes for endophytic fungi that protect the plant from herbivores by producing toxins. the fungal endophyte neotyphodium coenophialum in tall fescue grass has pest status in the american cattle industry. many legumes have rhizobium nitrogen - fixing bacteria in nodules of their roots, which fix nitrogen from the air for the plant to use ; in return, the plants supply sugars to the bacteria. nitrogen fixed in this way can become available to other plants, and is important in agriculture ; for example, farmers may grow a crop rotation of a legume such as beans, followed by a cereal such as wheat, to provide cash crops with a reduced input of nitrogen fertilizer. some 1 % of plants are parasitic. they range from the semi
zone of the gulf of maine, us. in most cases, facilitation and competition are inversely proportional. studies suggest that facilitation events in nature are rare compared to competition events and thus, competition is a greater driver for ecological processes. = = = improved resource availability = = = facilitation can increase access to limiting resources such as light, water, and nutrients for interacting species. for example, epiphytic plants often receive more direct sunlight in the canopies of their host plants than they would on the ground. also, nurse plants increase the amount of water available to seedlings in dry habitats because of reduced evapotranspiration beneath the shade of nurse plant canopies. a special case concerns human facilitation of sap - feeding birds. three african bird species ( village weaver ploceus cucullatus, common bulbul pycnonotus barbatus, and mouse β brown sunbird anthreptes gabonicus ) regularly feed on the sap flowing from holes made by local wine tappers in oil β palm trees elaies guineensis in the bijagos archipelago, guinea β bissau. however, the most familiar examples of increased access to resources through facilitation are the mutualistic transfers of nutrients between symbiotic organisms. a symbiosis is a prolonged, close association between organisms, and some examples of mutualistic symbioses include : gut flora associations between a host species and a microbe living in the host's digestive tract, wherein the host provides habitat and nourishment to the microbe in exchange for digestive services. for example, termites receive nourishment from cellulose digested by microbes inhabiting their gut. lichens associations between fungi and algae, wherein the fungus receives nutrients from the alga, and the alga is protected from harsh conditions causing desiccation. corals associations between reef - building corals and photosynthetic algae called zooxanthellae, wherein the zooxanthellae provide nutrition to the corals in the form of photosynthate, in exchange for nitrogen in coral waste products. mycorrhizae associations between fungi and plant roots, wherein the fungus facilitates nutrient uptake ( particularly nitrogen ) by the plant in exchange for carbon in the form of sugars from the plant root. there is a parallel example in marine environments of sponges on the roots of mangroves, with a relationship analogous to
, and photoperiodism. photosynthesis provides the energy required to produce the energy source of plants. phototropism is the effect of light on plant growth that causes the plant to grow toward or away from the light. photoperiodism is a plant's response or capacity to respond to photoperiod, a recurring cycle of light and dark periods of constant length. = = = sunlight = = = while sunlight is not always easily controlled by the gardener, it is an important element of garden design. the amount of available light is a critical factor in determining what plants may be grown. sunlight will, therefore, have a substantial influence on the character of the garden. for example, a rose garden is generally not successful in full shade, while a garden of hostas may not thrive in hot sun. as another example, a vegetable garden may need to be placed in a sunny location, and if that location is not ideal for the overall garden design goals, the designer may need to change other aspects of the garden. in some cases, the amount of available sunlight can be influenced by the gardener. the location of trees, other shade plants, garden structures, or, when designing an entire property, even buildings, might be selected or changed based on their influence in increasing or reducing the amount of sunlight provided to various areas of the property. in other cases, the amount of sunlight is not under the gardener's control. nearby buildings, plants on other properties, or simply the climate of the local area, may limit the available sunlight. or, substantial changes in the light conditions of the garden may not be within the gardener's means. in this case, it is important to plan a garden that is compatible with the existing light conditions. = = notable garden designers = = = = types of gardens = = = = = islamic gardens = = = garden design and the islamic garden tradition began with creating the paradise garden in ancient persia, in western asia. it evolved over the centuries, and in the different cultures islamic dynasties came to rule in asia, the near east, north africa, and the iberian peninsula. = = = = examples = = = = some styles and examples include : persian gardens eram garden fin garden mughal gardens nishat bagh shalimar gardens ( lahore ) yadavindra gardens ( pinjore ) charbagh taj mahal tomb of humayun gardens bagh ( garden ) bagh - e babur shalimar bagh ( srinagar ) al - andal
even when significant drawbacks are prevalent. these drawbacks faced by consumers include elevated costs of organic foods, imbalanced monetary price differentials between animal - intensive diets and plant - based alternatives, and an absence of comprehensive consumer guidance aligned with contemporary valuations. in 2020, an analysis of external climate costs of foods indicated that external greenhouse gas costs are typically highest for animal - based products β conventional and organic to about the same extent within that ecosystem subdomain β followed by conventional dairy products and lowest for organic plant - based foods. it finds contemporary monetary evaluations to be " inadequate " and policy - making that lead to reductions of these costs to be possible, appropriate and urgent. = = = agricultural pollution = = = = = sourcing sustainable food = = at the global level the environmental impact of agribusiness is being addressed through sustainable agriculture, cellular agriculture and organic farming. various alternatives to meat and novel classes of foods can substantially increase sustainability. there are large potential benefits of marine algae - based aquaculture for the development of a future healthy and sustainable food system. fungiculture, another sector of a growing bioeconomy besides algaculture, may also become a larger component of a sustainable food system. consumption shares of various other ingredients for meat analogues such as protein from pulses may also rise substantially in a sustainable food system. the integration of single - cell protein, which can be produced from captured co2. optimized dietary scenarios would also see changes in various other types of foods such as nuts, as well as pulses such as beans, which have favorable environmental and health profiles. complementary approaches under development include vertical farming of various types of foods and various agricultural technologies, often using digital agriculture. = = = sustainable seafood = = = sustainable seafood is seafood from either fished or farmed sources that can maintain or increase production in the future without jeopardizing the ecosystems from which it was acquired. the sustainable seafood movement has gained momentum as more people become aware about both overfishing and environmentally destructive fishing methods. the goal of sustainable seafood practices is to ensure that fish populations are able to continue to thrive, that marine habitats are protected, and that fishing and aquaculture practices do not have negative impacts on local communities or economies. there are several factors that go into determining whether a seafood product is sustainable or not. these include the method of fishing or farming, the health of the fish population, the impact on the surrounding environment, and the social and economic implications of the seafood production. some sustainable seafood practices include using methods that minimize
Answer:
|
nothing
| 0.3 |
If you wanted to see the source of sunshine you would look at
0. TV
1. the yellow dwarf
2. volcanoes
3. the moon
been the same as today, liquid water should not have existed on the earth's surface. however, there is evidence for the presence of water on the early earth, in the hadean and archean eons, leading to what is known as the faint young sun paradox. hypothesized solutions to this paradox include a vastly different atmosphere, with much higher concentrations of greenhouse gases than currently exist. over the following approximately 4 billion years, the energy output of the sun increased. over the next five billion years, the sun's ultimate death as it becomes a red giant and then a white dwarf will have large effects on climate, with the red giant phase possibly ending any life on earth that survives until that time. = = = = volcanism = = = = the volcanic eruptions considered to be large enough to affect the earth's climate on a scale of more than 1 year are the ones that inject over 100, 000 tons of so2 into the stratosphere. this is due to the optical properties of so2 and sulfate aerosols, which strongly absorb or scatter solar radiation, creating a global layer of sulfuric acid haze. on average, such eruptions occur several times per century, and cause cooling ( by partially blocking the transmission of solar radiation to the earth's surface ) for a period of several years. although volcanoes are technically part of the lithosphere, which itself is part of the climate system, the ipcc explicitly defines volcanism as an external forcing agent. notable eruptions in the historical records are the 1991 eruption of mount pinatubo which lowered global temperatures by about 0. 5 Β°c ( 0. 9 Β°f ) for up to three years, and the 1815 eruption of mount tambora causing the year without a summer. at a larger scale β a few times every 50 million to 100 million years β the eruption of large igneous provinces brings large quantities of igneous rock from the mantle and lithosphere to the earth's surface. carbon dioxide in the rock is then released into the atmosphere. small eruptions, with injections of less than 0. 1 mt of sulfur dioxide into the stratosphere, affect the atmosphere only subtly, as temperature changes are comparable with natural variability. however, because smaller eruptions occur at a much higher frequency, they too significantly affect earth's atmosphere. = = = = plate tectonics = = = = over the course of millions of years, the motion of tectonic plates reconfigures global land and ocean
/ s, in neptune's atmosphere. several large storm systems have been identified, including the great dark spot, a cyclonic storm system the size of eurasia, the scooter, a white cloud group further south than the great dark spot, and the wizard's eye / dark spot 2, a southern cyclonic storm. neptune, the farthest planet from earth, has increased in brightness since 1980. neptune's brightness is statistically correlated with its stratospheric temperature. hammel and lockwood hypothesize that the change in brightness includes a solar variation component as well as a seasonal component, though they did not find a statistically significant correlation with solar variation. they propose that the resolution of this issue will be clarified by brightness observations in the next few years : forcing by a change in sub - solar latitude should be reflected in a flattening and decline of brightness, while solar forcing should be reflected in a flattening and then resumed rise of brightness. = = other bodies in the solar system = = = = = natural satellites = = = ten of the many natural satellites in the solar system are known to have atmospheres : europa, io, callisto, enceladus, ganymede, titan, rhea, dione, triton and earth's moon. ganymede and europa both have very tenuous oxygen atmospheres, thought to be produced by radiation splitting the water ice present on the surface of these moons into hydrogen and oxygen. io has an extremely thin atmosphere consisting mainly of sulfur dioxide ( so2 ), arising from volcanism and sunlight - driven sublimation of surface sulfur dioxide deposits. the atmosphere of enceladus is also extremely thin and variable, consisting mainly of water vapor, nitrogen, methane, and carbon dioxide vented from the moon's interior through cryovolcanism. the extremely thin carbon dioxide atmosphere of callisto is thought to be replenished by sublimation from surface deposits. = = = = moon = = = = = = = = titan = = = = titan has by far the densest atmosphere of any moon. the titanian atmosphere is in fact denser than earth's, with a surface pressure of 147 kpa, one and a half times that of the earth. the atmosphere is 94. 2 % nitrogen, 5. 65 % methane, and 0. 099 % hydrogen, with the remaining 1. 6 % composed of other gases such as hydrocarbons ( including ethane
of the sky from the sun, rainbows are more visible the closer the sun is to the horizon. for example, if the sun is overhead, any possible rainbow appears near an observer's feet, making it hard to see, and involves very few raindrops between the observer's eyes and the ground, making any rainbow very sparse. other phenomena that are remarkable because they are forms of visual illusions include : crepuscular rays, anticrepuscular rays, and the apparent size of celestial objects such as the sun and moon. = = history = = a book on meteorological optics was published in the sixteenth century, but there have been numerous books on the subject since about 1950. the topic was popularised by the wide circulation of a book by marcel minnaert, light and color in the open air, in 1954. = = sun and moon size = = in the book of optics ( 1011 β 22 ad ), ibn al - haytham argued that vision occurs in the brain, and that personal experience has an effect on what people see and how they see, and that vision and perception are subjective. arguing against ptolemy's refraction theory for why people perceive the sun and moon larger at the horizon than when they are higher in the sky, he redefined the problem in terms of perceived, rather than real, enlargement. he said that judging the distance of an object depends on there being an uninterrupted sequence of intervening bodies between the object and the observer. critically, ibn al - haytham said that judging the size of an object depends on its judged distance : an object that appears near appears smaller than an object having the same image size on the retina that appears far. with the overhead moon, there is no uninterrupted sequence of intervening bodies. hence it appears far and small. with a horizon moon, there is an uninterrupted sequence of intervening bodies : all the objects between the observer and the horizon, so the moon appears far and large. through works by roger bacon, john pecham, and witelo based on ibn al - haytham's explanation, the moon illusion gradually came to be accepted as a psychological phenomenon, with ptolemy's theory being rejected in the 17th century. for over 100 years, research on the moon illusion has been conducted by vision scientists who invariably have been psychologists specializing in human perception. after reviewing the many different explanations in their 2002 book the mystery of the moon illusion, ross and plug concluded " no single theory has emerged
visual appearance of a galaxy with a particularly bright, star - like nucleus. as a group, they are intermediate between seyfert galaxies and quasar. most are giant ellipticals that are radio sources and display prominent emission lines. nadir the point on the celestial sphere exactly opposite from the zenith. thus, where the zenith is directly above an observer, the nadir is underfoot. the zenith and nadir form the two poles of the horizon line. naked eye also bare eye or unaided eye. the human eye as used without any magnifying or light - collecting optical aid, such as a telescope, nor any eye protection. many astronomical objects emit or reflect visible light that is sufficiently bright to fall within the limits of normal human visual perception, allowing observers to see them from the earth's surface without any special equipment. vision corrected to normal acuity using eyeglasses or contact lenses is still considered unaided. natural satellite also moon. any astronomical body that orbits a planet, minor planet, or sometimes another small solar system body. near - earth object ( neo ) any small solar system body, such as an asteroid or comet, whose orbit brings it into proximity with earth, generally by being less than 1. 3 au from the sun at its closest approach. nebula any astronomical object of indistinct nebulosity. in modern usage, the term typically refers to an interstellar cloud of dust, hydrogen, helium, and other ionized gases. historically, it was also used to refer to extended sources of luminosity that could not be resolved into their individual components, such as star clusters and galaxies. neutrino a type of elementary particle, electrically neutral and with an extremely small rest mass, that interacts with other particles only via the weak interaction and the gravitational interaction. neutrinos therefore typically pass through normal matter unimpeded and undetected. neutron star a type of compact star that is composed almost entirely of neutrons, which are a type of subatomic particle with no electrical charge. typically, neutron stars have a mass between about 1. 35 and 2. 0 times the mass of the sun, but with a radius of only 12 km ( 7. 5 mi ), making them among the densest known objects in the universe. new general catalogue ( ngc ) night sky the appearance of the earth's sky at nighttime, when the sun is below the horizon, and more specifically when clear weather and low levels of ambient light permit visibility of celestial objects such as
514 β 519. bibcode : 2012newa... 17.. 514b. doi : 10. 1016 / j. newast. 2011. 12. 001. batista, s. f. a. ; adibekyan, v. zh. ; et al. ( april 2014 ). " searching for solar siblings among the harps data ". astronomy & astrophysics. 564 : a43. arxiv : 1403. 1506. bibcode : 2014a & a... 564a.. 43b. doi : 10. 1051 / 0004 - 6361 / 201423645. liu, c. ; ruchti, g. ; et al. ( march 2015 ). " quest for the lost siblings of the sun ". astronomy & astrophysics. 575 : a51. arxiv : 1411. 5938. bibcode : 2015a & a... 575a.. 51l. doi : 10. 1051 / 0004 - 6361 / 201424998.
Answer:
|
the yellow dwarf
| null |
If you wanted to see the source of sunshine you would look at
0. TV
1. the yellow dwarf
2. volcanoes
3. the moon
been the same as today, liquid water should not have existed on the earth's surface. however, there is evidence for the presence of water on the early earth, in the hadean and archean eons, leading to what is known as the faint young sun paradox. hypothesized solutions to this paradox include a vastly different atmosphere, with much higher concentrations of greenhouse gases than currently exist. over the following approximately 4 billion years, the energy output of the sun increased. over the next five billion years, the sun's ultimate death as it becomes a red giant and then a white dwarf will have large effects on climate, with the red giant phase possibly ending any life on earth that survives until that time. = = = = volcanism = = = = the volcanic eruptions considered to be large enough to affect the earth's climate on a scale of more than 1 year are the ones that inject over 100, 000 tons of so2 into the stratosphere. this is due to the optical properties of so2 and sulfate aerosols, which strongly absorb or scatter solar radiation, creating a global layer of sulfuric acid haze. on average, such eruptions occur several times per century, and cause cooling ( by partially blocking the transmission of solar radiation to the earth's surface ) for a period of several years. although volcanoes are technically part of the lithosphere, which itself is part of the climate system, the ipcc explicitly defines volcanism as an external forcing agent. notable eruptions in the historical records are the 1991 eruption of mount pinatubo which lowered global temperatures by about 0. 5 Β°c ( 0. 9 Β°f ) for up to three years, and the 1815 eruption of mount tambora causing the year without a summer. at a larger scale β a few times every 50 million to 100 million years β the eruption of large igneous provinces brings large quantities of igneous rock from the mantle and lithosphere to the earth's surface. carbon dioxide in the rock is then released into the atmosphere. small eruptions, with injections of less than 0. 1 mt of sulfur dioxide into the stratosphere, affect the atmosphere only subtly, as temperature changes are comparable with natural variability. however, because smaller eruptions occur at a much higher frequency, they too significantly affect earth's atmosphere. = = = = plate tectonics = = = = over the course of millions of years, the motion of tectonic plates reconfigures global land and ocean
/ s, in neptune's atmosphere. several large storm systems have been identified, including the great dark spot, a cyclonic storm system the size of eurasia, the scooter, a white cloud group further south than the great dark spot, and the wizard's eye / dark spot 2, a southern cyclonic storm. neptune, the farthest planet from earth, has increased in brightness since 1980. neptune's brightness is statistically correlated with its stratospheric temperature. hammel and lockwood hypothesize that the change in brightness includes a solar variation component as well as a seasonal component, though they did not find a statistically significant correlation with solar variation. they propose that the resolution of this issue will be clarified by brightness observations in the next few years : forcing by a change in sub - solar latitude should be reflected in a flattening and decline of brightness, while solar forcing should be reflected in a flattening and then resumed rise of brightness. = = other bodies in the solar system = = = = = natural satellites = = = ten of the many natural satellites in the solar system are known to have atmospheres : europa, io, callisto, enceladus, ganymede, titan, rhea, dione, triton and earth's moon. ganymede and europa both have very tenuous oxygen atmospheres, thought to be produced by radiation splitting the water ice present on the surface of these moons into hydrogen and oxygen. io has an extremely thin atmosphere consisting mainly of sulfur dioxide ( so2 ), arising from volcanism and sunlight - driven sublimation of surface sulfur dioxide deposits. the atmosphere of enceladus is also extremely thin and variable, consisting mainly of water vapor, nitrogen, methane, and carbon dioxide vented from the moon's interior through cryovolcanism. the extremely thin carbon dioxide atmosphere of callisto is thought to be replenished by sublimation from surface deposits. = = = = moon = = = = = = = = titan = = = = titan has by far the densest atmosphere of any moon. the titanian atmosphere is in fact denser than earth's, with a surface pressure of 147 kpa, one and a half times that of the earth. the atmosphere is 94. 2 % nitrogen, 5. 65 % methane, and 0. 099 % hydrogen, with the remaining 1. 6 % composed of other gases such as hydrocarbons ( including ethane
of the sky from the sun, rainbows are more visible the closer the sun is to the horizon. for example, if the sun is overhead, any possible rainbow appears near an observer's feet, making it hard to see, and involves very few raindrops between the observer's eyes and the ground, making any rainbow very sparse. other phenomena that are remarkable because they are forms of visual illusions include : crepuscular rays, anticrepuscular rays, and the apparent size of celestial objects such as the sun and moon. = = history = = a book on meteorological optics was published in the sixteenth century, but there have been numerous books on the subject since about 1950. the topic was popularised by the wide circulation of a book by marcel minnaert, light and color in the open air, in 1954. = = sun and moon size = = in the book of optics ( 1011 β 22 ad ), ibn al - haytham argued that vision occurs in the brain, and that personal experience has an effect on what people see and how they see, and that vision and perception are subjective. arguing against ptolemy's refraction theory for why people perceive the sun and moon larger at the horizon than when they are higher in the sky, he redefined the problem in terms of perceived, rather than real, enlargement. he said that judging the distance of an object depends on there being an uninterrupted sequence of intervening bodies between the object and the observer. critically, ibn al - haytham said that judging the size of an object depends on its judged distance : an object that appears near appears smaller than an object having the same image size on the retina that appears far. with the overhead moon, there is no uninterrupted sequence of intervening bodies. hence it appears far and small. with a horizon moon, there is an uninterrupted sequence of intervening bodies : all the objects between the observer and the horizon, so the moon appears far and large. through works by roger bacon, john pecham, and witelo based on ibn al - haytham's explanation, the moon illusion gradually came to be accepted as a psychological phenomenon, with ptolemy's theory being rejected in the 17th century. for over 100 years, research on the moon illusion has been conducted by vision scientists who invariably have been psychologists specializing in human perception. after reviewing the many different explanations in their 2002 book the mystery of the moon illusion, ross and plug concluded " no single theory has emerged
visual appearance of a galaxy with a particularly bright, star - like nucleus. as a group, they are intermediate between seyfert galaxies and quasar. most are giant ellipticals that are radio sources and display prominent emission lines. nadir the point on the celestial sphere exactly opposite from the zenith. thus, where the zenith is directly above an observer, the nadir is underfoot. the zenith and nadir form the two poles of the horizon line. naked eye also bare eye or unaided eye. the human eye as used without any magnifying or light - collecting optical aid, such as a telescope, nor any eye protection. many astronomical objects emit or reflect visible light that is sufficiently bright to fall within the limits of normal human visual perception, allowing observers to see them from the earth's surface without any special equipment. vision corrected to normal acuity using eyeglasses or contact lenses is still considered unaided. natural satellite also moon. any astronomical body that orbits a planet, minor planet, or sometimes another small solar system body. near - earth object ( neo ) any small solar system body, such as an asteroid or comet, whose orbit brings it into proximity with earth, generally by being less than 1. 3 au from the sun at its closest approach. nebula any astronomical object of indistinct nebulosity. in modern usage, the term typically refers to an interstellar cloud of dust, hydrogen, helium, and other ionized gases. historically, it was also used to refer to extended sources of luminosity that could not be resolved into their individual components, such as star clusters and galaxies. neutrino a type of elementary particle, electrically neutral and with an extremely small rest mass, that interacts with other particles only via the weak interaction and the gravitational interaction. neutrinos therefore typically pass through normal matter unimpeded and undetected. neutron star a type of compact star that is composed almost entirely of neutrons, which are a type of subatomic particle with no electrical charge. typically, neutron stars have a mass between about 1. 35 and 2. 0 times the mass of the sun, but with a radius of only 12 km ( 7. 5 mi ), making them among the densest known objects in the universe. new general catalogue ( ngc ) night sky the appearance of the earth's sky at nighttime, when the sun is below the horizon, and more specifically when clear weather and low levels of ambient light permit visibility of celestial objects such as
514 β 519. bibcode : 2012newa... 17.. 514b. doi : 10. 1016 / j. newast. 2011. 12. 001. batista, s. f. a. ; adibekyan, v. zh. ; et al. ( april 2014 ). " searching for solar siblings among the harps data ". astronomy & astrophysics. 564 : a43. arxiv : 1403. 1506. bibcode : 2014a & a... 564a.. 43b. doi : 10. 1051 / 0004 - 6361 / 201423645. liu, c. ; ruchti, g. ; et al. ( march 2015 ). " quest for the lost siblings of the sun ". astronomy & astrophysics. 575 : a51. arxiv : 1411. 5938. bibcode : 2015a & a... 575a.. 51l. doi : 10. 1051 / 0004 - 6361 / 201424998.
Answer:
|
volcanoes
| 0.3 |
Which is likely to be hotter?
0. steaming coffee
1. the ocean
2. the forest
3. tepid water
much more thermal inertia. when radiation is directly absorbed or the surface temperature changes, thermal energy will flow as sensible heat either into or out of the bulk mass of these components via conduction / convection heat transfer processes. the transformation of water between its solid / liquid / vapor states also acts as a source or sink of potential energy in the form of latent heat. these processes buffer the surface conditions against some of the rapid radiative changes in the atmosphere. as a result, the daytime versus nighttime difference in surface temperatures is relatively small. likewise, earth's climate system as a whole shows a slow response to shifts in the atmospheric radiation balance. the top few meters of earth's oceans harbor more thermal energy than its entire atmosphere. like atmospheric gases, fluidic ocean waters transport vast amounts of such energy over the planet's surface. sensible heat also moves into and out of great depths under conditions that favor downwelling or upwelling. over 90 percent of the extra energy that has accumulated on earth from ongoing global warming since 1970 has been stored in the ocean. about one - third has propagated to depths below 700 meters. the overall rate of growth has also risen during recent decades, reaching close to 500 tw ( 1 w / m2 ) as of 2020. that led to about 14 zettajoules ( zj ) of heat gain for the year, exceeding the 570 exajoules ( = 160, 000 tw - hr ) of total primary energy consumed by humans by a factor of at least 20. = = = heating / cooling rate analysis = = = generally speaking, changes to earth's energy flux balance can be thought of as being the result of external forcings ( both natural and anthropogenic, radiative and non - radiative ), system feedbacks, and internal system variability. such changes are primarily expressed as observable shifts in temperature ( t ), clouds ( c ), water vapor ( w ), aerosols ( a ), trace greenhouse gases ( g ), land / ocean / ice surface reflectance ( s ), and as minor shifts in insolaton ( i ) among other possible factors. earth's heating / cooling rate can then be analyzed over selected timeframes ( Ξ΄t ) as the net change in energy ( Ξ΄e ) associated with these attributes : Ξ΄ e / Ξ΄ t = ( Ξ΄ e t + Ξ΄ e c + Ξ΄ e w + Ξ΄ e a + Ξ΄ e g + Ξ΄ e s + Ξ΄ e
to transfer heat more quickly as the water cools. evaporation : the evaporation of the warmer water reduces the mass of the water to be frozen. evaporation is endothermic, meaning that the water mass is cooled by vapor carrying away the heat, but this alone probably does not account for the entirety of the effect. convection, accelerating heat transfers : reduction of water density below 4 Β°c ( 39 Β°f ) tends to suppress the convection currents that cool the lower part of the liquid mass ; the lower density of hot water would reduce this effect, perhaps sustaining the more rapid initial cooling. higher convection in the warmer water may also spread ice crystals around faster. frost : frost has insulating effects. the lower temperature water will tend to freeze from the top, reducing further heat loss by radiation and air convection, while the warmer water will tend to freeze from the bottom and sides because of water convection. this is disputed as there are experiments that account for this factor. solutes : calcium carbonate, magnesium carbonate, and other mineral salts dissolved in water can precipitate out when water is boiled, leading to an increase in the freezing point compared to non - boiled water that contains all the dissolved minerals. thermal conductivity : the container of hotter liquid may melt through a layer of frost that is acting as an insulator under the container ( frost is an insulator, as mentioned above ), allowing the container to come into direct contact with a much colder lower layer that the frost formed on ( ice, refrigeration coils, etc. ) the container now rests on a much colder surface ( or one better at removing heat, such as refrigeration coils ) than the originally colder water, and so cools far faster from this point on. conduction through the bottom is dominant, when the bottom of a hot beaker has been wetted by melted ice, and then sticky frozen to it. in context of mpemba effect it is a mistake to think that bottom ice insulates, compared to poor air cooling properties. dissolved gases : cold water can contain more dissolved gases than hot water, which may somehow change the properties of the water with respect to convection currents, a proposition that has some experimental support but no theoretical explanation. hydrogen bonding : in warm water, hydrogen bonding is weaker. crystallization : another explanation suggests that the relatively higher population of water hexamer states in warm water might be responsible for the faster crystallization. distribution function : strong deviations from the maxwell β boltzmann distribution
also impair water quality. hot pavement and rooftop surfaces transfer their excess heat to stormwater, which then drains into storm sewers and raises water temperatures as it is released into streams, rivers, ponds, and lakes. additionally, increased urban water body temperatures lead to a decrease in biodiversity in the water. for example, in august 2001, rains over cedar rapids, iowa led to a 10. 5 Β°c ( 18. 9 Β°f ) rise in the nearby stream within one hour, resulting in a fish kill which affected an estimated 188 fish. since the temperature of the rain was comparatively cool, the deaths could be attributed to the hot pavement of the city. similar events have been documented across the american midwest, as well as oregon and california. rapid temperature changes can be stressful to aquatic ecosystems. with the temperature of the nearby buildings sometimes reaching a difference of over 50 Β°f ( 28 Β°c ) from the near - surface air temperature, precipitation warms rapidly, and run - off into nearby streams, lakes and rivers ( or other bodies of water ) to provide excessive thermal pollution. the increase in thermal pollution has the potential to increase water temperature by 20 to 30 Β°f ( 11 to 17 Β°c ). this increase causes the fish species inhabiting the body of water to undergo thermal stress and shock due to the rapid change in temperature of their habitat. permeable pavements may reduce these effects by percolating water through the pavement into subsurface storage areas where it can be dissipated through absorption and evaporation. = = = on animals = = = species that are good at colonizing can use conditions provided by urban heat islands to thrive in regions outside of their normal range. examples of this include the grey - headed flying fox ( pteropus poliocephalus ) and the common house gecko ( hemidactylus frenatus ). grey - headed flying foxes, found in melbourne, australia, colonized urban habitats following the increase in temperatures there. increased temperatures, causing warmer winter conditions, made the city more similar in climate to the more northerly wildland habitat of the species. with temperate climates, urban heat islands will extend the growing season, therefore altering breeding strategies of inhabiting species. this can be best observed in the effects that urban heat islands have on water temperature ( see effects on water bodies ). urban heat islands caused by cities have altered the natural selection process. selective pressures like temporal variation in food, predation and water are relaxed causing a new set of selective forces to roll out. for example, within urban habitats
also deduced that as much latent heat as was supplied into boiling the distillate ( thus giving the quantity of fuel needed ) also had to be absorbed to condense it again ( thus giving the cooling water required ). = = = = quantifying latent heat = = = = in 1762, black announced the following research and results to a society of professors at the university of glasgow. black had placed equal masses of ice at 32 Β°f ( 0 Β°c ) and water at 33 Β°f ( 0. 6 Β°c ) respectively in two identical, well separated containers. the water and the ice were both evenly heated to 40 Β°f by the air in the room, which was at a constant 47 Β°f ( 8 Β°c ). the water had therefore received 40 β 33 = 7 β degrees of heat β. the ice had been heated for 21 times longer and had therefore received 7 Γ 21 = 147 β degrees of heat β. the temperature of the ice had increased by 8 Β°f. the ice had thus absorbed 8 β degrees of heat β, which black called sensible heat, manifest as a temperature increase, which could be felt and measured. in addition to that, 147 β 8 = 139 β degrees of heat β were absorbed as latent heat, manifest as phase change rather than as temperature change. black next showed that a water temperature of 176 Β°f was needed to melt an equal mass of ice until it was all 32 Β°f. so now 176 β 32 = 144 β degrees of heat β seemed to be needed to melt the ice. the modern value for the heat of fusion of ice would be 143 β degrees of heat β on the same scale ( 79. 5 β degrees of heat celsius β ). finally, black increased the temperature of a mass of water, then vaporized an equal mass of water by even heating. he showed that 830 β degrees of heat β was needed for the vaporization ; again based on the time required. the modern value for the heat of vaporization of water would be 967 β degrees of heat β on the same scale. = = = james prescott joule = = = later, james prescott joule characterised latent energy as the energy of interaction in a given configuration of particles, i. e. a form of potential energy, and the sensible heat as an energy that was indicated by the thermometer, relating the latter to thermal energy. = = specific latent heat = = a specific latent heat ( l ) expresses the amount of energy in the form of heat ( q ) required
) in old faithful, a geyser in yellowstone national park. in hydrothermal vents, the temperature can exceed 400 Β°c ( 752 Β°f ). at sea level, the boiling point of water is 100 Β°c ( 212 Β°f ). as atmospheric pressure decreases with altitude, the boiling point decreases by 1 Β°c every 274 meters. high - altitude cooking takes longer than sea - level cooking. for example, at 1, 524 metres ( 5, 000 ft ), cooking time must be increased by a fourth to achieve the desired result. conversely, a pressure cooker can be used to decrease cooking times by raising the boiling temperature. in a vacuum, water will boil at room temperature. = = = = triple and critical points = = = = on a pressure / temperature phase diagram ( see figure ), there are curves separating solid from vapor, vapor from liquid, and liquid from solid. these meet at a single point called the triple point, where all three phases can coexist. the triple point is at a temperature of 273. 16 k ( 0. 01 Β°c ; 32. 02 Β°f ) and a pressure of 611. 657 pascals ( 0. 00604 atm ; 0. 0887 psi ) ; it is the lowest pressure at which liquid water can exist. until 2019, the triple point was used to define the kelvin temperature scale. the water / vapor phase curve terminates at 647. 096 k ( 373. 946 Β°c ; 705. 103 Β°f ) and 22. 064 megapascals ( 3, 200. 1 psi ; 217. 75 atm ). this is known as the critical point. at higher temperatures and pressures the liquid and vapor phases form a continuous phase called a supercritical fluid. it can be gradually compressed or expanded between gas - like and liquid - like densities ; its properties ( which are quite different from those of ambient water ) are sensitive to density. for example, for suitable pressures and temperatures it can mix freely with nonpolar compounds, including most organic compounds. this makes it useful in a variety of applications including high - temperature electrochemistry and as an ecologically benign solvent or catalyst in chemical reactions involving organic compounds. in earth's mantle, it acts as a solvent during mineral formation, dissolution and deposition. = = = = phases of ice and water = = = = the normal form of ice on the surface of earth is ice ih, a phase that forms crystals with hexagonal symmetry. another with cubic crystalline symmetry, ice
Answer:
|
steaming coffee
| null |
Which is likely to be hotter?
0. steaming coffee
1. the ocean
2. the forest
3. tepid water
much more thermal inertia. when radiation is directly absorbed or the surface temperature changes, thermal energy will flow as sensible heat either into or out of the bulk mass of these components via conduction / convection heat transfer processes. the transformation of water between its solid / liquid / vapor states also acts as a source or sink of potential energy in the form of latent heat. these processes buffer the surface conditions against some of the rapid radiative changes in the atmosphere. as a result, the daytime versus nighttime difference in surface temperatures is relatively small. likewise, earth's climate system as a whole shows a slow response to shifts in the atmospheric radiation balance. the top few meters of earth's oceans harbor more thermal energy than its entire atmosphere. like atmospheric gases, fluidic ocean waters transport vast amounts of such energy over the planet's surface. sensible heat also moves into and out of great depths under conditions that favor downwelling or upwelling. over 90 percent of the extra energy that has accumulated on earth from ongoing global warming since 1970 has been stored in the ocean. about one - third has propagated to depths below 700 meters. the overall rate of growth has also risen during recent decades, reaching close to 500 tw ( 1 w / m2 ) as of 2020. that led to about 14 zettajoules ( zj ) of heat gain for the year, exceeding the 570 exajoules ( = 160, 000 tw - hr ) of total primary energy consumed by humans by a factor of at least 20. = = = heating / cooling rate analysis = = = generally speaking, changes to earth's energy flux balance can be thought of as being the result of external forcings ( both natural and anthropogenic, radiative and non - radiative ), system feedbacks, and internal system variability. such changes are primarily expressed as observable shifts in temperature ( t ), clouds ( c ), water vapor ( w ), aerosols ( a ), trace greenhouse gases ( g ), land / ocean / ice surface reflectance ( s ), and as minor shifts in insolaton ( i ) among other possible factors. earth's heating / cooling rate can then be analyzed over selected timeframes ( Ξ΄t ) as the net change in energy ( Ξ΄e ) associated with these attributes : Ξ΄ e / Ξ΄ t = ( Ξ΄ e t + Ξ΄ e c + Ξ΄ e w + Ξ΄ e a + Ξ΄ e g + Ξ΄ e s + Ξ΄ e
to transfer heat more quickly as the water cools. evaporation : the evaporation of the warmer water reduces the mass of the water to be frozen. evaporation is endothermic, meaning that the water mass is cooled by vapor carrying away the heat, but this alone probably does not account for the entirety of the effect. convection, accelerating heat transfers : reduction of water density below 4 Β°c ( 39 Β°f ) tends to suppress the convection currents that cool the lower part of the liquid mass ; the lower density of hot water would reduce this effect, perhaps sustaining the more rapid initial cooling. higher convection in the warmer water may also spread ice crystals around faster. frost : frost has insulating effects. the lower temperature water will tend to freeze from the top, reducing further heat loss by radiation and air convection, while the warmer water will tend to freeze from the bottom and sides because of water convection. this is disputed as there are experiments that account for this factor. solutes : calcium carbonate, magnesium carbonate, and other mineral salts dissolved in water can precipitate out when water is boiled, leading to an increase in the freezing point compared to non - boiled water that contains all the dissolved minerals. thermal conductivity : the container of hotter liquid may melt through a layer of frost that is acting as an insulator under the container ( frost is an insulator, as mentioned above ), allowing the container to come into direct contact with a much colder lower layer that the frost formed on ( ice, refrigeration coils, etc. ) the container now rests on a much colder surface ( or one better at removing heat, such as refrigeration coils ) than the originally colder water, and so cools far faster from this point on. conduction through the bottom is dominant, when the bottom of a hot beaker has been wetted by melted ice, and then sticky frozen to it. in context of mpemba effect it is a mistake to think that bottom ice insulates, compared to poor air cooling properties. dissolved gases : cold water can contain more dissolved gases than hot water, which may somehow change the properties of the water with respect to convection currents, a proposition that has some experimental support but no theoretical explanation. hydrogen bonding : in warm water, hydrogen bonding is weaker. crystallization : another explanation suggests that the relatively higher population of water hexamer states in warm water might be responsible for the faster crystallization. distribution function : strong deviations from the maxwell β boltzmann distribution
also impair water quality. hot pavement and rooftop surfaces transfer their excess heat to stormwater, which then drains into storm sewers and raises water temperatures as it is released into streams, rivers, ponds, and lakes. additionally, increased urban water body temperatures lead to a decrease in biodiversity in the water. for example, in august 2001, rains over cedar rapids, iowa led to a 10. 5 Β°c ( 18. 9 Β°f ) rise in the nearby stream within one hour, resulting in a fish kill which affected an estimated 188 fish. since the temperature of the rain was comparatively cool, the deaths could be attributed to the hot pavement of the city. similar events have been documented across the american midwest, as well as oregon and california. rapid temperature changes can be stressful to aquatic ecosystems. with the temperature of the nearby buildings sometimes reaching a difference of over 50 Β°f ( 28 Β°c ) from the near - surface air temperature, precipitation warms rapidly, and run - off into nearby streams, lakes and rivers ( or other bodies of water ) to provide excessive thermal pollution. the increase in thermal pollution has the potential to increase water temperature by 20 to 30 Β°f ( 11 to 17 Β°c ). this increase causes the fish species inhabiting the body of water to undergo thermal stress and shock due to the rapid change in temperature of their habitat. permeable pavements may reduce these effects by percolating water through the pavement into subsurface storage areas where it can be dissipated through absorption and evaporation. = = = on animals = = = species that are good at colonizing can use conditions provided by urban heat islands to thrive in regions outside of their normal range. examples of this include the grey - headed flying fox ( pteropus poliocephalus ) and the common house gecko ( hemidactylus frenatus ). grey - headed flying foxes, found in melbourne, australia, colonized urban habitats following the increase in temperatures there. increased temperatures, causing warmer winter conditions, made the city more similar in climate to the more northerly wildland habitat of the species. with temperate climates, urban heat islands will extend the growing season, therefore altering breeding strategies of inhabiting species. this can be best observed in the effects that urban heat islands have on water temperature ( see effects on water bodies ). urban heat islands caused by cities have altered the natural selection process. selective pressures like temporal variation in food, predation and water are relaxed causing a new set of selective forces to roll out. for example, within urban habitats
also deduced that as much latent heat as was supplied into boiling the distillate ( thus giving the quantity of fuel needed ) also had to be absorbed to condense it again ( thus giving the cooling water required ). = = = = quantifying latent heat = = = = in 1762, black announced the following research and results to a society of professors at the university of glasgow. black had placed equal masses of ice at 32 Β°f ( 0 Β°c ) and water at 33 Β°f ( 0. 6 Β°c ) respectively in two identical, well separated containers. the water and the ice were both evenly heated to 40 Β°f by the air in the room, which was at a constant 47 Β°f ( 8 Β°c ). the water had therefore received 40 β 33 = 7 β degrees of heat β. the ice had been heated for 21 times longer and had therefore received 7 Γ 21 = 147 β degrees of heat β. the temperature of the ice had increased by 8 Β°f. the ice had thus absorbed 8 β degrees of heat β, which black called sensible heat, manifest as a temperature increase, which could be felt and measured. in addition to that, 147 β 8 = 139 β degrees of heat β were absorbed as latent heat, manifest as phase change rather than as temperature change. black next showed that a water temperature of 176 Β°f was needed to melt an equal mass of ice until it was all 32 Β°f. so now 176 β 32 = 144 β degrees of heat β seemed to be needed to melt the ice. the modern value for the heat of fusion of ice would be 143 β degrees of heat β on the same scale ( 79. 5 β degrees of heat celsius β ). finally, black increased the temperature of a mass of water, then vaporized an equal mass of water by even heating. he showed that 830 β degrees of heat β was needed for the vaporization ; again based on the time required. the modern value for the heat of vaporization of water would be 967 β degrees of heat β on the same scale. = = = james prescott joule = = = later, james prescott joule characterised latent energy as the energy of interaction in a given configuration of particles, i. e. a form of potential energy, and the sensible heat as an energy that was indicated by the thermometer, relating the latter to thermal energy. = = specific latent heat = = a specific latent heat ( l ) expresses the amount of energy in the form of heat ( q ) required
) in old faithful, a geyser in yellowstone national park. in hydrothermal vents, the temperature can exceed 400 Β°c ( 752 Β°f ). at sea level, the boiling point of water is 100 Β°c ( 212 Β°f ). as atmospheric pressure decreases with altitude, the boiling point decreases by 1 Β°c every 274 meters. high - altitude cooking takes longer than sea - level cooking. for example, at 1, 524 metres ( 5, 000 ft ), cooking time must be increased by a fourth to achieve the desired result. conversely, a pressure cooker can be used to decrease cooking times by raising the boiling temperature. in a vacuum, water will boil at room temperature. = = = = triple and critical points = = = = on a pressure / temperature phase diagram ( see figure ), there are curves separating solid from vapor, vapor from liquid, and liquid from solid. these meet at a single point called the triple point, where all three phases can coexist. the triple point is at a temperature of 273. 16 k ( 0. 01 Β°c ; 32. 02 Β°f ) and a pressure of 611. 657 pascals ( 0. 00604 atm ; 0. 0887 psi ) ; it is the lowest pressure at which liquid water can exist. until 2019, the triple point was used to define the kelvin temperature scale. the water / vapor phase curve terminates at 647. 096 k ( 373. 946 Β°c ; 705. 103 Β°f ) and 22. 064 megapascals ( 3, 200. 1 psi ; 217. 75 atm ). this is known as the critical point. at higher temperatures and pressures the liquid and vapor phases form a continuous phase called a supercritical fluid. it can be gradually compressed or expanded between gas - like and liquid - like densities ; its properties ( which are quite different from those of ambient water ) are sensitive to density. for example, for suitable pressures and temperatures it can mix freely with nonpolar compounds, including most organic compounds. this makes it useful in a variety of applications including high - temperature electrochemistry and as an ecologically benign solvent or catalyst in chemical reactions involving organic compounds. in earth's mantle, it acts as a solvent during mineral formation, dissolution and deposition. = = = = phases of ice and water = = = = the normal form of ice on the surface of earth is ice ih, a phase that forms crystals with hexagonal symmetry. another with cubic crystalline symmetry, ice
Answer:
|
tepid water
| 0.3 |
The hotter a liquid gets, the faster
0. it turns into animals
1. it transform to gas
2. it turns into seven
3. it turns into frogs
rises, the bird becomes top heavy and tips over. when the bird tips over, the bottom end of the neck tube rises above the surface of the liquid in the bottom bulb. a bubble of warm vapor rises up the tube through this gap, displacing liquid as it goes. liquid flows back to the bottom bulb ( the toy is designed so that when it has tipped over the neck's tilt allows this ). pressure equalizes between top and bottom bulbs. the weight of the liquid in the bottom bulb restores the bird to its vertical position. the liquid in the bottom bulb is heated by ambient air, which is at a temperature slightly higher than the temperature of the bird's head. if a glass of water is placed so that the beak dips into it on its descent, the bird will continue to absorb water and the cycle will continue as long as there is enough water in the glass to keep the head wet. however, the bird will continue to dip even without a source of water, as long as the head is wet, or as long as a temperature differential is maintained between the head and body. this differential can be generated without evaporative cooling in the head ; for instance, a heat source directed at the bottom bulb will create a pressure differential between top and bottom that will drive the engine. the ultimate source of energy is the temperature gradient between the toy's head and base ; the toy is not a perpetual motion machine. = = physical and chemical principles = = the drinking bird is an exhibition of several physical laws and is therefore a staple of basic chemistry and physics education. these include : the dichloromethane with a low boiling point ( 39. 6 Β°c ( 103. 3 Β°f ) under standard pressure po = 105 pa β as the drinking bird is first evacuated, partially filled and sealed, the pressure and thus the boiling point in the drinking bird will be different ), gives the heat engine the ability to extract motion from low temperatures. the drinking bird is a heat engine that works at room temperature. the combined gas law, which establishes a proportional relationship between temperature and pressure exerted by a gas in a constant volume. the ideal gas law, which establishes a proportional relationship between number of gas particles and pressure in a constant volume. the maxwell β boltzmann distribution, which establishes that molecules in a given space at a given temperature vary in energy level, and therefore can exist in multiple phases ( solid / liquid / gas ) at a single temperature. heat of vaporization ( or condensation
boltzmann distribution, which establishes that molecules in a given space at a given temperature vary in energy level, and therefore can exist in multiple phases ( solid / liquid / gas ) at a single temperature. heat of vaporization ( or condensation ), which establishes that substances absorb ( or give off ) heat when changing state at a constant temperature. torque and center of mass. capillary action of the wicking felt. wet - bulb temperature : the temperature difference between the head and body depends on the relative humidity of the air. the operation of the bird is also affected by relative humidity. by using a water - ethanol mixture instead of water, the effect of different rates of evaporation can be demonstrated. by considering the difference between the wet and dry bulb temperatures, it is possible to develop a mathematical expression to calculate the maximum work that can be produced from a given amount of water " drunk ". such analysis is based on the definition of the carnot heat engine efficiency and the psychrometric concepts. the drinking bird may also be considered to be an entropy engine driven by the difference of the entropy of liquid water and the entropy of water vapor dispersed in air, that is, the sum of the entropy of evaporation of pure water plus the entropy of dilution of water vapor in air. the evaporation of water is an endothermic process requiring the input of thermal energy or a positive enthalpy flow from the environment. since a spontaneous process requires a negative change in gibbs free energy, the positive enthalpy has to be overcome by the large entropy increase. = = history = = by the 1760s ( or earlier ) german artisans had invented a so - called " pulse hammer " ( pulshammer ). in 1767 benjamin franklin visited germany, saw a pulse hammer, and in 1768, improved it. franklin's pulse hammer consisted of two glass bulbs connected by a u - shaped tube ; one of the bulbs was partially filled with water in equilibrium with its vapor. holding the partially filled bulb in one's hand would cause the water to flow into the empty bulb. in 1872, the italian physicist and engineer enrico bernardi combined three franklin tubes to build a simple heat motor that was powered by evaporation in a way similar to the drinking bird. in 1881 israel l. landis got a patent for a similar oscillating motor. a year later ( 1882 ), the iske brothers got a patent for a similar motor. unlike the drinking bird, the lower tank was
a direct measurement of the change in height of a liquid column generated by thermal expansion is a measurement of the apparent expansion of the liquid. thus the experiment simultaneously measures two coefficients of expansion and measurement of the expansion of a liquid must account for the expansion of the container as well. for example, when a flask with a long narrow stem, containing enough liquid to partially fill the stem itself, is placed in a heat bath, the height of the liquid column in the stem will initially drop, followed immediately by a rise of that height until the whole system of flask, liquid and heat bath has warmed through. the initial drop in the height of the liquid column is not due to an initial contraction of the liquid, but rather to the expansion of the flask as it contacts the heat bath first. soon after, the liquid in the flask is heated by the flask itself and begins to expand. since liquids typically have a greater percent expansion than solids for the same temperature change, the expansion of the liquid in the flask eventually exceeds that of the flask, causing the level of liquid in the flask to rise. for small and equal rises in temperature, the increase in volume ( real expansion ) of a liquid is equal to the sum of the apparent increase in volume ( apparent expansion ) of the liquid and the increase in volume of the containing vessel. the absolute expansion of the liquid is the apparent expansion corrected for the expansion of the containing vessel. = = examples and applications = = the expansion and contraction of the materials must be considered when designing large structures, when using tape or chain to measure distances for land surveys, when designing molds for casting hot material, and in other engineering applications when large changes in dimension due to temperature are expected. thermal expansion is also used in mechanical applications to fit parts over one another, e. g. a bushing can be fitted over a shaft by making its inner diameter slightly smaller than the diameter of the shaft, then heating it until it fits over the shaft, and allowing it to cool after it has been pushed over the shaft, thus achieving a'shrink fit '. induction shrink fitting is a common industrial method to pre - heat metal components between 150 Β°c and 300 Β°c thereby causing them to expand and allow for the insertion or removal of another component. there exist some alloys with a very small linear expansion coefficient, used in applications that demand very small changes in physical dimension over a range of temperatures. one of these is invar 36, with expansion approximately equal to 0. 6Γ10β6 kβ1
point in the maximum, considerable vapor is being formed, making it difficult for the liquid to continuously wet the surface to receive heat from the surface. this causes the heat flux to reduce after this point. at extremes, film boiling commonly known as the leidenfrost effect is observed. the process of forming steam bubbles within liquid in micro cavities adjacent to the wall if the wall temperature at the heat transfer surface rises above the saturation temperature while the bulk of the liquid ( heat exchanger ) is subcooled. the bubbles grow until they reach some critical size, at which point they separate from the wall and are carried into the main fluid stream. there the bubbles collapse because the temperature of bulk fluid is not as high as at the heat transfer surface, where the bubbles were created. this collapsing is also responsible for the sound a water kettle produces during heat up but before the temperature at which bulk boiling is reached. heat transfer and mass transfer during nucleate boiling has a significant effect on the heat transfer rate. this heat transfer process helps quickly and efficiently to carry away the energy created at the heat transfer surface and is therefore sometimes desirable β for example in nuclear power plants, where liquid is used as a coolant. the effects of nucleate boiling take place at two locations : the liquid - wall interface the bubble - liquid interface the nucleate boiling process has a complex nature. a limited number of experimental studies provided valuable insights into the boiling phenomena, however these studies provided often contradictory data due to internal recalculation ( state of chaos in the fluid not applying to classical thermodynamic methods of calculation, therefore giving wrong return values ) and have not provided conclusive findings yet to develop models and correlations. nucleate boiling phenomenon still requires more understanding. = = boiling heat transfer correlations = = the nucleate boiling regime is important to engineers because of the high heat fluxes possible with moderate temperature differences. the data can be correlated by an equation of the form n u b = c f c ( r e b, p r l ) { \ displaystyle \ mathrm { nu } _ { b } = c _ { fc } ( \ mathrm { re } _ { b }, \ mathrm { pr } _ { l } ) } where nu is the nusselt number, defined as : n u b = ( q / a ) d b ( t s β t s a t ) k l { \ displaystyle \ mathrm { nu } _ { b } = {
processes in these applications. since they bring in an added complexity due to the undulations in the surfaces, they need to be tackled with mathematical finesse through elegant simplification techniques. also, they do affect the flow and heat transfer characteristics, thereby behaving differently from straight smooth surfaces. for a visual experience of natural convection, a glass filled with hot water and some red food dye may be placed inside a fish tank with cold, clear water. the convection currents of the red liquid may be seen to rise and fall in different regions, then eventually settle, illustrating the process as heat gradients are dissipated. = = newton's law of cooling = = convection - cooling is sometimes loosely assumed to be described by newton's law of cooling. newton's law states that the rate of heat loss of a body is proportional to the difference in temperatures between the body and its surroundings while under the effects of a breeze. the constant of proportionality is the heat transfer coefficient. the law applies when the coefficient is independent, or relatively independent, of the temperature difference between object and environment. in classical natural convective heat transfer, the heat transfer coefficient is dependent on the temperature. however, newton's law does approximate reality when the temperature changes are relatively small, and for forced air and pumped liquid cooling, where the fluid velocity does not rise with increasing temperature difference. = = convective heat transfer = = the basic relationship for heat transfer by convection is : q = h a ( t β t f ) { \ displaystyle { \ dot { q } } = ha ( t - t _ { f } ) } where q { \ displaystyle { \ dot { q } } } is the heat transferred per unit time, a is the area of the object, h is the heat transfer coefficient, t is the object's surface temperature, and tf is the fluid temperature. the convective heat transfer coefficient is dependent upon the physical properties of the fluid and the physical situation. values of h have been measured and tabulated for commonly encountered fluids and flow situations. = = see also = = conjugate convective heat transfer convection forced convection natural convection mixed convection heat transfer coefficient heat transfer enhancement heisler chart thermal conductivity convection β diffusion equation = = references = =
Answer:
|
it transform to gas
| null |
The hotter a liquid gets, the faster
0. it turns into animals
1. it transform to gas
2. it turns into seven
3. it turns into frogs
rises, the bird becomes top heavy and tips over. when the bird tips over, the bottom end of the neck tube rises above the surface of the liquid in the bottom bulb. a bubble of warm vapor rises up the tube through this gap, displacing liquid as it goes. liquid flows back to the bottom bulb ( the toy is designed so that when it has tipped over the neck's tilt allows this ). pressure equalizes between top and bottom bulbs. the weight of the liquid in the bottom bulb restores the bird to its vertical position. the liquid in the bottom bulb is heated by ambient air, which is at a temperature slightly higher than the temperature of the bird's head. if a glass of water is placed so that the beak dips into it on its descent, the bird will continue to absorb water and the cycle will continue as long as there is enough water in the glass to keep the head wet. however, the bird will continue to dip even without a source of water, as long as the head is wet, or as long as a temperature differential is maintained between the head and body. this differential can be generated without evaporative cooling in the head ; for instance, a heat source directed at the bottom bulb will create a pressure differential between top and bottom that will drive the engine. the ultimate source of energy is the temperature gradient between the toy's head and base ; the toy is not a perpetual motion machine. = = physical and chemical principles = = the drinking bird is an exhibition of several physical laws and is therefore a staple of basic chemistry and physics education. these include : the dichloromethane with a low boiling point ( 39. 6 Β°c ( 103. 3 Β°f ) under standard pressure po = 105 pa β as the drinking bird is first evacuated, partially filled and sealed, the pressure and thus the boiling point in the drinking bird will be different ), gives the heat engine the ability to extract motion from low temperatures. the drinking bird is a heat engine that works at room temperature. the combined gas law, which establishes a proportional relationship between temperature and pressure exerted by a gas in a constant volume. the ideal gas law, which establishes a proportional relationship between number of gas particles and pressure in a constant volume. the maxwell β boltzmann distribution, which establishes that molecules in a given space at a given temperature vary in energy level, and therefore can exist in multiple phases ( solid / liquid / gas ) at a single temperature. heat of vaporization ( or condensation
boltzmann distribution, which establishes that molecules in a given space at a given temperature vary in energy level, and therefore can exist in multiple phases ( solid / liquid / gas ) at a single temperature. heat of vaporization ( or condensation ), which establishes that substances absorb ( or give off ) heat when changing state at a constant temperature. torque and center of mass. capillary action of the wicking felt. wet - bulb temperature : the temperature difference between the head and body depends on the relative humidity of the air. the operation of the bird is also affected by relative humidity. by using a water - ethanol mixture instead of water, the effect of different rates of evaporation can be demonstrated. by considering the difference between the wet and dry bulb temperatures, it is possible to develop a mathematical expression to calculate the maximum work that can be produced from a given amount of water " drunk ". such analysis is based on the definition of the carnot heat engine efficiency and the psychrometric concepts. the drinking bird may also be considered to be an entropy engine driven by the difference of the entropy of liquid water and the entropy of water vapor dispersed in air, that is, the sum of the entropy of evaporation of pure water plus the entropy of dilution of water vapor in air. the evaporation of water is an endothermic process requiring the input of thermal energy or a positive enthalpy flow from the environment. since a spontaneous process requires a negative change in gibbs free energy, the positive enthalpy has to be overcome by the large entropy increase. = = history = = by the 1760s ( or earlier ) german artisans had invented a so - called " pulse hammer " ( pulshammer ). in 1767 benjamin franklin visited germany, saw a pulse hammer, and in 1768, improved it. franklin's pulse hammer consisted of two glass bulbs connected by a u - shaped tube ; one of the bulbs was partially filled with water in equilibrium with its vapor. holding the partially filled bulb in one's hand would cause the water to flow into the empty bulb. in 1872, the italian physicist and engineer enrico bernardi combined three franklin tubes to build a simple heat motor that was powered by evaporation in a way similar to the drinking bird. in 1881 israel l. landis got a patent for a similar oscillating motor. a year later ( 1882 ), the iske brothers got a patent for a similar motor. unlike the drinking bird, the lower tank was
a direct measurement of the change in height of a liquid column generated by thermal expansion is a measurement of the apparent expansion of the liquid. thus the experiment simultaneously measures two coefficients of expansion and measurement of the expansion of a liquid must account for the expansion of the container as well. for example, when a flask with a long narrow stem, containing enough liquid to partially fill the stem itself, is placed in a heat bath, the height of the liquid column in the stem will initially drop, followed immediately by a rise of that height until the whole system of flask, liquid and heat bath has warmed through. the initial drop in the height of the liquid column is not due to an initial contraction of the liquid, but rather to the expansion of the flask as it contacts the heat bath first. soon after, the liquid in the flask is heated by the flask itself and begins to expand. since liquids typically have a greater percent expansion than solids for the same temperature change, the expansion of the liquid in the flask eventually exceeds that of the flask, causing the level of liquid in the flask to rise. for small and equal rises in temperature, the increase in volume ( real expansion ) of a liquid is equal to the sum of the apparent increase in volume ( apparent expansion ) of the liquid and the increase in volume of the containing vessel. the absolute expansion of the liquid is the apparent expansion corrected for the expansion of the containing vessel. = = examples and applications = = the expansion and contraction of the materials must be considered when designing large structures, when using tape or chain to measure distances for land surveys, when designing molds for casting hot material, and in other engineering applications when large changes in dimension due to temperature are expected. thermal expansion is also used in mechanical applications to fit parts over one another, e. g. a bushing can be fitted over a shaft by making its inner diameter slightly smaller than the diameter of the shaft, then heating it until it fits over the shaft, and allowing it to cool after it has been pushed over the shaft, thus achieving a'shrink fit '. induction shrink fitting is a common industrial method to pre - heat metal components between 150 Β°c and 300 Β°c thereby causing them to expand and allow for the insertion or removal of another component. there exist some alloys with a very small linear expansion coefficient, used in applications that demand very small changes in physical dimension over a range of temperatures. one of these is invar 36, with expansion approximately equal to 0. 6Γ10β6 kβ1
point in the maximum, considerable vapor is being formed, making it difficult for the liquid to continuously wet the surface to receive heat from the surface. this causes the heat flux to reduce after this point. at extremes, film boiling commonly known as the leidenfrost effect is observed. the process of forming steam bubbles within liquid in micro cavities adjacent to the wall if the wall temperature at the heat transfer surface rises above the saturation temperature while the bulk of the liquid ( heat exchanger ) is subcooled. the bubbles grow until they reach some critical size, at which point they separate from the wall and are carried into the main fluid stream. there the bubbles collapse because the temperature of bulk fluid is not as high as at the heat transfer surface, where the bubbles were created. this collapsing is also responsible for the sound a water kettle produces during heat up but before the temperature at which bulk boiling is reached. heat transfer and mass transfer during nucleate boiling has a significant effect on the heat transfer rate. this heat transfer process helps quickly and efficiently to carry away the energy created at the heat transfer surface and is therefore sometimes desirable β for example in nuclear power plants, where liquid is used as a coolant. the effects of nucleate boiling take place at two locations : the liquid - wall interface the bubble - liquid interface the nucleate boiling process has a complex nature. a limited number of experimental studies provided valuable insights into the boiling phenomena, however these studies provided often contradictory data due to internal recalculation ( state of chaos in the fluid not applying to classical thermodynamic methods of calculation, therefore giving wrong return values ) and have not provided conclusive findings yet to develop models and correlations. nucleate boiling phenomenon still requires more understanding. = = boiling heat transfer correlations = = the nucleate boiling regime is important to engineers because of the high heat fluxes possible with moderate temperature differences. the data can be correlated by an equation of the form n u b = c f c ( r e b, p r l ) { \ displaystyle \ mathrm { nu } _ { b } = c _ { fc } ( \ mathrm { re } _ { b }, \ mathrm { pr } _ { l } ) } where nu is the nusselt number, defined as : n u b = ( q / a ) d b ( t s β t s a t ) k l { \ displaystyle \ mathrm { nu } _ { b } = {
processes in these applications. since they bring in an added complexity due to the undulations in the surfaces, they need to be tackled with mathematical finesse through elegant simplification techniques. also, they do affect the flow and heat transfer characteristics, thereby behaving differently from straight smooth surfaces. for a visual experience of natural convection, a glass filled with hot water and some red food dye may be placed inside a fish tank with cold, clear water. the convection currents of the red liquid may be seen to rise and fall in different regions, then eventually settle, illustrating the process as heat gradients are dissipated. = = newton's law of cooling = = convection - cooling is sometimes loosely assumed to be described by newton's law of cooling. newton's law states that the rate of heat loss of a body is proportional to the difference in temperatures between the body and its surroundings while under the effects of a breeze. the constant of proportionality is the heat transfer coefficient. the law applies when the coefficient is independent, or relatively independent, of the temperature difference between object and environment. in classical natural convective heat transfer, the heat transfer coefficient is dependent on the temperature. however, newton's law does approximate reality when the temperature changes are relatively small, and for forced air and pumped liquid cooling, where the fluid velocity does not rise with increasing temperature difference. = = convective heat transfer = = the basic relationship for heat transfer by convection is : q = h a ( t β t f ) { \ displaystyle { \ dot { q } } = ha ( t - t _ { f } ) } where q { \ displaystyle { \ dot { q } } } is the heat transferred per unit time, a is the area of the object, h is the heat transfer coefficient, t is the object's surface temperature, and tf is the fluid temperature. the convective heat transfer coefficient is dependent upon the physical properties of the fluid and the physical situation. values of h have been measured and tabulated for commonly encountered fluids and flow situations. = = see also = = conjugate convective heat transfer convection forced convection natural convection mixed convection heat transfer coefficient heat transfer enhancement heisler chart thermal conductivity convection β diffusion equation = = references = =
Answer:
|
it turns into animals
| 0.3 |
What requires an electrical conductor?
0. cording
1. rocks
2. winds
3. fires
that lines maintain minimum clearances. adverse weather conditions, such as high winds and low temperatures, interrupt transmission. wind speeds as low as 23 knots ( 43 km / h ) can permit conductors to encroach operating clearances, resulting in a flashover and loss of supply. oscillatory motion of the physical line is termed conductor gallop or flutter depending on the frequency and amplitude of oscillation. = = = underground = = = electric power can be transmitted by underground power cables. underground cables take up no right - of - way, have lower visibility, and are less affected by weather. however, cables must be insulated. cable and excavation costs are much higher than overhead construction. faults in buried transmission lines take longer to locate and repair. in some metropolitan areas, cables are enclosed by metal pipe and insulated with dielectric fluid ( usually an oil ) that is either static or circulated via pumps. if an electric fault damages the pipe and leaks dielectric, liquid nitrogen is used to freeze portions of the pipe to enable draining and repair. this extends the repair period and increases costs. the temperature of the pipe and surroundings are monitored throughout the repair period. underground lines are limited by their thermal capacity, which permits less overload or re - rating lines. long underground ac cables have significant capacitance, which reduces their ability to provide useful power beyond 50 miles ( 80 kilometres ). dc cables are not limited in length by their capacitance. = = history = = commercial electric power was initially transmitted at the same voltage used by lighting and mechanical loads. this restricted the distance between generating plant and loads. in 1882, dc voltage could not easily be increased for long - distance transmission. different classes of loads ( for example, lighting, fixed motors, and traction / railway systems ) required different voltages, and so used different generators and circuits. thus, generators were sited near their loads, a practice that later became known as distributed generation using large numbers of small generators. transmission of alternating current ( ac ) became possible after lucien gaulard and john dixon gibbs built what they called the secondary generator, an early transformer provided with 1 : 1 turn ratio and open magnetic circuit, in 1881. the first long distance ac line was 34 kilometres ( 21 miles ) long, built for the 1884 international exhibition of electricity in turin, italy. it was powered by a 2 kv, 130 hz siemens & halske alternator and featured several gaulard transformers with primary windings connected in series, which fed incandescent
the seismoelectrical method ( which is different from the electroseismic physical principle ) is based on the generation of electromagnetic fields in soils and rocks by seismic waves. this technique is still under development and in the future it may have applications like detecting and characterizing fluids in the underground by their electrical properties, among others, usually related to fluids ( porosity, transmissivity, physical properties ). = = operation = = when a seismic wave encounters an interface, it creates a charge separation at the interface forming an electric dipole. this dipole radiates an electromagnetic wave that can be detected by antennae on the ground surface. as the seismic ( p or compression ) waves stress earth materials, four geophysical phenomena occur : the resistivity of the earth materials is modulated by the seismic wave ; electrokinetic effects analogous to streaming potentials are created by the seismic wave ; piezoelectric effects are created by the seismic wave ; and high - frequency, audio - and high - frequency radio frequency impulsive responses are generated in sulfide minerals ( sometimes referred to as rpe ). the dominant application of the electroseismic method is to measure the electrokinetic effect or streaming potential ( item 2, above ). electrokinetic effects are initiated by sound waves ( typically p - waves ) passing through a porous rock inducing relative motion of the rock matrix and fluid. motion of the ionic fluid through the capillaries in the rock occurs with cations ( or less commonly, anions ) preferentially adhering to the capillary walls, so that applied pressure and resulting fluid flow relative to the rock matrix produces an electric dipole. in a non - homogeneous formation, the seismic wave generates an oscillating flow of fluid and a corresponding oscillating electrical and em field. the resulting em wave can be detected by electrode pairs placed on the ground surface. however, p - waves moving through a solid that contains some moisture also generates an electric phenomenon called coseismic waves. the coseismic waves travel with p - waves and are not sensitive to electrical properties of the subsurface. the dipole antenna cannot distinguish electrokinetic signal from coseismic signal so it records them both, and coseismic waves must be removed while processing field data to be able to actually interpret electrokinetic effect. at the moment, there is not a field routine operation method, but in scientific studies an array of several dipole antennas is placed along a straight
and shadowed sides of the earth, toward the equator on the side of the earth facing the sun ( that is, during the day ), and toward the poles on the night side of the planet. both telluric and magnetotelluric methods are used for exploring the structure beneath the earth's surface ( such as in industrial prospecting ). for mineral exploration the targets are any subsurface structures with a distinguishable resistance in comparison to its surroundings. uses include geothermal exploration, mining exploration, petroleum exploration, mapping of fault zones, ground water exploration and monitoring, investigation of magma chambers, and investigation of boundaries of tectonic plates. earth batteries tap a useful low voltage current from telluric currents and were used for telegraph systems as far back as the 1840s. in industrial prospecting activity that uses the telluric current method, electrodes are properly located on the ground to sense the voltage difference between locations caused by the oscillatory telluric currents. it is recognized that a low frequency window ( lfw ) exists when telluric currents pass through the earth's substrata. in the frequencies of the lfw, the earth acts as a conductor. = = in fiction = = the main plot of the 1988 novel foucault's pendulum by umberto eco revolves around conspiracy theorists who believe that they are searching for the umbilicus mundi ( latin for " the navel of the world " ), the mystic " center of the earth " which is supposed to be a certain point from where a person could control the energies and shapes of the earth, thus reforming it at will. the novel takes this even further by suggesting that ( in the view of the conspiratorialists ) monuments like the eiffel tower are nothing more than giant antennas related to these energies. telluric currents, along what are effectively ley lines, are discovered to be a means of mysterious communication in thomas pynchon's 1997 novel mason & dixon and are associated with the book's chinese - jesuit subplot. as with eco, cited above, pynchon also reflects upon hollow earth theories in this work. = = see also = = atmospheric electricity β electricity in planetary atmospheres birkeland current β currents flowing along geomagnetic field lines electrical resistivity tomography β a geophysical technique for imaging sub - surface structures geomagnetically induced current β ground level manifestation of space weather geomagnetic jerk β sudden change in the earth's
joule heating ( also known as resistive heating, resistance heating, or ohmic heating ) is the process by which the passage of an electric current through a conductor produces heat. joule's first law ( also just joule's law ), also known in countries of the former ussr as the joule β lenz law, states that the power of heating generated by an electrical conductor equals the product of its resistance and the square of the current. joule heating affects the whole electric conductor, unlike the peltier effect which transfers heat from one electrical junction to another. joule - heating or resistive - heating is used in many devices and industrial processes. the part that converts electricity into heat is called a heating element. practical applications of joule heating include but not limited to : buildings are often heated with electric heaters where grid power is available. electric stoves and ovens use joule heating to cook food. soldering irons generate heat to melt conductive solder and make electrical connections. cartridge heaters are used in various manufacturing processes. electric fuses are used as a safety device, breaking a circuit by melting if enough current flows to heat them to the melting point. electronic cigarettes vaporize liquid by joule heating. food processing equipment may make use of joule heating : running a current through food material ( which behave as an electrical resistor ) causes heat release inside the food. the alternating electrical current coupled with the resistance of the food causes the generation of heat. a higher resistance increases the heat generated. joule heating allows for fast and uniform heating of food products, which maintains quality. products with particulates heat up faster ( compared to conventional heat processing ) due to higher resistance. = = history = = james prescott joule first published in december 1840, an abstract in the proceedings of the royal society, suggesting that heat could be generated by an electrical current. joule immersed a length of wire in a fixed mass of water and measured the temperature rise due to a known current flowing through the wire for a 30 minute period. by varying the current and the length of the wire he deduced that the heat produced was proportional to the square of the current multiplied by the electrical resistance of the immersed wire. in 1841 and 1842, subsequent experiments showed that the amount of heat generated was proportional to the chemical energy used in the voltaic pile that generated the template. this led joule to reject the caloric theory ( at that time the dominant theory ) in favor of the mechanical theory of heat ( according
a cable locator or cable avoidance tool ( cat ) is an instrument used for detecting the presence and approximate location of buried services in advance of undertaking excavation works. it aims to avoid accidents while excavating. a number of types of detecting technology can be employed by such instruments, including use of magnetic fields, radio frequencies, signal generation, metal detectors, ground - penetrating radar and rfid. = = description = = underground cables are one of the things that enable telecommunication and power transmission. they are especially beneficial to densely populated areas, particularly those locations where overhead cable posts are unavailable or are not ideal. locating underground cables β as well as other underground facilities β is an integral pre - excavation process mandated by laws and guided by a number of industry standards. during excavations, underground cables become at risk of getting damaged. in fact, utility strikes are a common occurrence on construction sites, resulting in compromised worker and public safety, repair costs, and work delay, among others. based on the 2018 damage information reporting tool ( dirt ) report of the common ground alliance ( cga ), some of the most common root causes of utility strikes include failure to call 811 before digging, improper excavation practices, and inaccurate marking of underground facilities. furthermore, the cga also noted that locator errors are one of the common causes of strike incidents. this emphasizes the need for understanding how cable locators work as well as how different cable types can be most accurately detected. = = detection methods = = different cable locators employ different methods to function. the two known methods, passive utility detection locating naturally present or naturally produced signals known as a passive signal. the other is to locate a signal that is applied aka an active signal, are called the passive utility detection and active utility detection. it β s important to note, however, that while both methods can help locators distinguish an underground utility, they do not confirm its presence nor its absolute location. furthermore, an unmarked ground is not a guarantee that there are no utilities underground. = = references = =
Answer:
|
cording
| null |
What requires an electrical conductor?
0. cording
1. rocks
2. winds
3. fires
that lines maintain minimum clearances. adverse weather conditions, such as high winds and low temperatures, interrupt transmission. wind speeds as low as 23 knots ( 43 km / h ) can permit conductors to encroach operating clearances, resulting in a flashover and loss of supply. oscillatory motion of the physical line is termed conductor gallop or flutter depending on the frequency and amplitude of oscillation. = = = underground = = = electric power can be transmitted by underground power cables. underground cables take up no right - of - way, have lower visibility, and are less affected by weather. however, cables must be insulated. cable and excavation costs are much higher than overhead construction. faults in buried transmission lines take longer to locate and repair. in some metropolitan areas, cables are enclosed by metal pipe and insulated with dielectric fluid ( usually an oil ) that is either static or circulated via pumps. if an electric fault damages the pipe and leaks dielectric, liquid nitrogen is used to freeze portions of the pipe to enable draining and repair. this extends the repair period and increases costs. the temperature of the pipe and surroundings are monitored throughout the repair period. underground lines are limited by their thermal capacity, which permits less overload or re - rating lines. long underground ac cables have significant capacitance, which reduces their ability to provide useful power beyond 50 miles ( 80 kilometres ). dc cables are not limited in length by their capacitance. = = history = = commercial electric power was initially transmitted at the same voltage used by lighting and mechanical loads. this restricted the distance between generating plant and loads. in 1882, dc voltage could not easily be increased for long - distance transmission. different classes of loads ( for example, lighting, fixed motors, and traction / railway systems ) required different voltages, and so used different generators and circuits. thus, generators were sited near their loads, a practice that later became known as distributed generation using large numbers of small generators. transmission of alternating current ( ac ) became possible after lucien gaulard and john dixon gibbs built what they called the secondary generator, an early transformer provided with 1 : 1 turn ratio and open magnetic circuit, in 1881. the first long distance ac line was 34 kilometres ( 21 miles ) long, built for the 1884 international exhibition of electricity in turin, italy. it was powered by a 2 kv, 130 hz siemens & halske alternator and featured several gaulard transformers with primary windings connected in series, which fed incandescent
the seismoelectrical method ( which is different from the electroseismic physical principle ) is based on the generation of electromagnetic fields in soils and rocks by seismic waves. this technique is still under development and in the future it may have applications like detecting and characterizing fluids in the underground by their electrical properties, among others, usually related to fluids ( porosity, transmissivity, physical properties ). = = operation = = when a seismic wave encounters an interface, it creates a charge separation at the interface forming an electric dipole. this dipole radiates an electromagnetic wave that can be detected by antennae on the ground surface. as the seismic ( p or compression ) waves stress earth materials, four geophysical phenomena occur : the resistivity of the earth materials is modulated by the seismic wave ; electrokinetic effects analogous to streaming potentials are created by the seismic wave ; piezoelectric effects are created by the seismic wave ; and high - frequency, audio - and high - frequency radio frequency impulsive responses are generated in sulfide minerals ( sometimes referred to as rpe ). the dominant application of the electroseismic method is to measure the electrokinetic effect or streaming potential ( item 2, above ). electrokinetic effects are initiated by sound waves ( typically p - waves ) passing through a porous rock inducing relative motion of the rock matrix and fluid. motion of the ionic fluid through the capillaries in the rock occurs with cations ( or less commonly, anions ) preferentially adhering to the capillary walls, so that applied pressure and resulting fluid flow relative to the rock matrix produces an electric dipole. in a non - homogeneous formation, the seismic wave generates an oscillating flow of fluid and a corresponding oscillating electrical and em field. the resulting em wave can be detected by electrode pairs placed on the ground surface. however, p - waves moving through a solid that contains some moisture also generates an electric phenomenon called coseismic waves. the coseismic waves travel with p - waves and are not sensitive to electrical properties of the subsurface. the dipole antenna cannot distinguish electrokinetic signal from coseismic signal so it records them both, and coseismic waves must be removed while processing field data to be able to actually interpret electrokinetic effect. at the moment, there is not a field routine operation method, but in scientific studies an array of several dipole antennas is placed along a straight
and shadowed sides of the earth, toward the equator on the side of the earth facing the sun ( that is, during the day ), and toward the poles on the night side of the planet. both telluric and magnetotelluric methods are used for exploring the structure beneath the earth's surface ( such as in industrial prospecting ). for mineral exploration the targets are any subsurface structures with a distinguishable resistance in comparison to its surroundings. uses include geothermal exploration, mining exploration, petroleum exploration, mapping of fault zones, ground water exploration and monitoring, investigation of magma chambers, and investigation of boundaries of tectonic plates. earth batteries tap a useful low voltage current from telluric currents and were used for telegraph systems as far back as the 1840s. in industrial prospecting activity that uses the telluric current method, electrodes are properly located on the ground to sense the voltage difference between locations caused by the oscillatory telluric currents. it is recognized that a low frequency window ( lfw ) exists when telluric currents pass through the earth's substrata. in the frequencies of the lfw, the earth acts as a conductor. = = in fiction = = the main plot of the 1988 novel foucault's pendulum by umberto eco revolves around conspiracy theorists who believe that they are searching for the umbilicus mundi ( latin for " the navel of the world " ), the mystic " center of the earth " which is supposed to be a certain point from where a person could control the energies and shapes of the earth, thus reforming it at will. the novel takes this even further by suggesting that ( in the view of the conspiratorialists ) monuments like the eiffel tower are nothing more than giant antennas related to these energies. telluric currents, along what are effectively ley lines, are discovered to be a means of mysterious communication in thomas pynchon's 1997 novel mason & dixon and are associated with the book's chinese - jesuit subplot. as with eco, cited above, pynchon also reflects upon hollow earth theories in this work. = = see also = = atmospheric electricity β electricity in planetary atmospheres birkeland current β currents flowing along geomagnetic field lines electrical resistivity tomography β a geophysical technique for imaging sub - surface structures geomagnetically induced current β ground level manifestation of space weather geomagnetic jerk β sudden change in the earth's
joule heating ( also known as resistive heating, resistance heating, or ohmic heating ) is the process by which the passage of an electric current through a conductor produces heat. joule's first law ( also just joule's law ), also known in countries of the former ussr as the joule β lenz law, states that the power of heating generated by an electrical conductor equals the product of its resistance and the square of the current. joule heating affects the whole electric conductor, unlike the peltier effect which transfers heat from one electrical junction to another. joule - heating or resistive - heating is used in many devices and industrial processes. the part that converts electricity into heat is called a heating element. practical applications of joule heating include but not limited to : buildings are often heated with electric heaters where grid power is available. electric stoves and ovens use joule heating to cook food. soldering irons generate heat to melt conductive solder and make electrical connections. cartridge heaters are used in various manufacturing processes. electric fuses are used as a safety device, breaking a circuit by melting if enough current flows to heat them to the melting point. electronic cigarettes vaporize liquid by joule heating. food processing equipment may make use of joule heating : running a current through food material ( which behave as an electrical resistor ) causes heat release inside the food. the alternating electrical current coupled with the resistance of the food causes the generation of heat. a higher resistance increases the heat generated. joule heating allows for fast and uniform heating of food products, which maintains quality. products with particulates heat up faster ( compared to conventional heat processing ) due to higher resistance. = = history = = james prescott joule first published in december 1840, an abstract in the proceedings of the royal society, suggesting that heat could be generated by an electrical current. joule immersed a length of wire in a fixed mass of water and measured the temperature rise due to a known current flowing through the wire for a 30 minute period. by varying the current and the length of the wire he deduced that the heat produced was proportional to the square of the current multiplied by the electrical resistance of the immersed wire. in 1841 and 1842, subsequent experiments showed that the amount of heat generated was proportional to the chemical energy used in the voltaic pile that generated the template. this led joule to reject the caloric theory ( at that time the dominant theory ) in favor of the mechanical theory of heat ( according
a cable locator or cable avoidance tool ( cat ) is an instrument used for detecting the presence and approximate location of buried services in advance of undertaking excavation works. it aims to avoid accidents while excavating. a number of types of detecting technology can be employed by such instruments, including use of magnetic fields, radio frequencies, signal generation, metal detectors, ground - penetrating radar and rfid. = = description = = underground cables are one of the things that enable telecommunication and power transmission. they are especially beneficial to densely populated areas, particularly those locations where overhead cable posts are unavailable or are not ideal. locating underground cables β as well as other underground facilities β is an integral pre - excavation process mandated by laws and guided by a number of industry standards. during excavations, underground cables become at risk of getting damaged. in fact, utility strikes are a common occurrence on construction sites, resulting in compromised worker and public safety, repair costs, and work delay, among others. based on the 2018 damage information reporting tool ( dirt ) report of the common ground alliance ( cga ), some of the most common root causes of utility strikes include failure to call 811 before digging, improper excavation practices, and inaccurate marking of underground facilities. furthermore, the cga also noted that locator errors are one of the common causes of strike incidents. this emphasizes the need for understanding how cable locators work as well as how different cable types can be most accurately detected. = = detection methods = = different cable locators employ different methods to function. the two known methods, passive utility detection locating naturally present or naturally produced signals known as a passive signal. the other is to locate a signal that is applied aka an active signal, are called the passive utility detection and active utility detection. it β s important to note, however, that while both methods can help locators distinguish an underground utility, they do not confirm its presence nor its absolute location. furthermore, an unmarked ground is not a guarantee that there are no utilities underground. = = references = =
Answer:
|
winds
| 0.3 |
A planet that revolves around a star is exposed to what?
0. mountains
1. oceans
2. solar rays
3. moons
little is known of satellite systems beyond the solar system, although it is inferred that natural satellites are common. possible signs of exomoons have been detected around exoplanets such as kepler - 1625b. it is also theorised that rogue planets ejected from their planetary system could retain a system of satellites. = = natural formation and evolution = = satellite systems, like planetary systems, are the product of gravitational attraction, but are also sustained through fictitious forces. while the general consensus is that most planetary systems are formed from an accretionary disks, the formation of satellite systems is less clear. the origin of many moons are investigated on a case - by - case basis, and the larger systems are thought to have formed through a combination of one or more processes. = = = system stability = = = the hill sphere is the region in which an astronomical body dominates the attraction of satellites. of the solar system planets, neptune and uranus have the largest hill spheres, due to the lessened gravitational influence of the sun at their far orbits, however all of the giant planets have hill spheres in the vicinity of 100 million kilometres in radius. by contrast, the hill spheres of mercury and ceres, being closer to the sun are quite small. outside of the hill sphere, the sun dominates the gravitational influence, with the exception of the lagrangian points. satellites are stable at the l4 and l5 lagrangian points. these lie at the third corners of the two equilateral triangles in the plane of orbit whose common base is the line between the centers of the two masses, such that the point lies behind ( l5 ) or ahead ( l4 ) of the smaller mass with regard to its orbit around the larger mass. the triangular points ( l4 and l5 ) are stable equilibria, provided that the ratio of m1 / m2 is nearly 24. 96. when a body at these points is perturbed, it moves away from the point, but the factor opposite of that which is increased or decreased by the perturbation ( either gravity or angular momentum - induced speed ) will also increase or decrease, bending the object's path into a stable, kidney - bean - shaped orbit around the point ( as seen in the corotating frame of reference ). it is generally thought that natural satellites should orbit in the same direction as the planet is rotating ( known as prograde orbit ). as such, the terminology regular moon is used for these orbit. however a retrograde
of instability. mars's obliquity is quite variable over millions of years and may be in a chaotic state ; it varies as much as 0Β° to 60Β° over some millions of years, depending on perturbations of the planets. some authors dispute that mars's obliquity is chaotic, and show that tidal dissipation and viscous core - mantle coupling are adequate for it to have reached a fully damped state, similar to mercury and venus. the occasional shifts in the axial tilt of mars have been suggested as an explanation for the appearance and disappearance of rivers and lakes over the course of the existence of mars. a shift could cause a burst of methane into the atmosphere, causing warming, but then the methane would be destroyed and the climate would become arid again. the obliquities of the outer planets are considered relatively stable. = = extrasolar planets = = the stellar obliquity Οs, i. e. the axial tilt of a star with respect to the orbital plane of one of its planets, has been determined for only a few systems. by 2012, 49 stars have had sky - projected spin - orbit misalignment Ξ» has been observed, which serves as a lower limit to Οs. most of these measurements rely on the rossiter β mclaughlin effect. as of 2024 the axial tilt of 4 exoplanets have been measured with one of them vhs 1256 b having a uranus like tilt of 90 degrees Β± 25 degrees. astrophysicists have applied tidal theories to predict the obliquity of extrasolar planets. it has been shown that the obliquities of exoplanets in the habitable zone around low - mass stars tend to be eroded in less than a billion years, which means that they would not have tilt - induced seasons as earth has. = = see also = = axial parallelism milankovitch cycles polar motion pole shift rotation around a fixed axis true polar wander = = references = = = = external links = = national space science data center seidelmann, p. kenneth ; archinal, brent a. ; a'hearn, michael f. ; et al. ( 2007 ). " report of the iau / iag working group on cartographic coordinates and rotational elements : 2006 ". celestial mechanics and dynamical astronomy. 98 ( 3 ) : 155 β 180. bibcode : 2007cemda.. 98.. 155s. doi : 10. 1007 / s10
the gravity of the sun. all planetary moons and rings are located well inside the hill sphere and orbit the corresponding planet. gravitational interactions between such satellites can be seen, e. g., in the stable 1 : 2 : 4 orbital resonance of jupiter's moons ganymede, europa and io. also subdivisions and structures within the rings of saturn are caused by resonances with satellites. e. g. the gap between the inner b ring and the outer a ring has been cleared by a 2 : 1 resonance with the moon mimas. also some narrow discrete rings of saturn, uranus, and neptune like saturn's f ring are shaped and held in place by the gravity of one or two shepherd moons. = = = solar radiation pressure effects = = = solar radiation exerts the repulsive radiation pressure force fr on meteoroids and interplanetary dust particles : f r = l q p r a 4 Ο r 2 c, { \ displaystyle f _ { r } = { { l _ { \ odot } q _ { pr } a } \ over { 4 \ pi r ^ { 2 } c } }, } where l { \ displaystyle { l _ { \ odot } } } is the solar luminosity or l 4 Ο r 2 { \ displaystyle l _ { \ odot } \ over { 4 \ pi r ^ { 2 } } } is the solar irradiance at heliocentric distance r, q p r { \ displaystyle q _ { \ rm { pr } } } is the radiation pressure coefficient of the particle, a { \ displaystyle a } is the cross section ( for spherical particles a = Ο s 2 { \ displaystyle a = \ pi s ^ { 2 } } with particle radius s { \ displaystyle s } ), c { \ displaystyle c } is the speed of light. the radiation pressure coefficient, q p r { \ displaystyle q _ { \ rm { pr } } }, depends on optical properties of the particle like absorption, reflection, and light scattering integrated over all wavelengths of the solar spectrum. it can be calculated by using e. g. mie theorie, discrete dipole approximation, or even microwave analog experiments. solar radiation pressure reduces the effective force of gravity on a dust particle and is characterized by the dimensionless parameter Ξ² { \ displaystyle \ beta }, the ratio of the radiation pressure force f r { \ displaystyle f _ { r } } to the force of gravity
5813Γ10β5 light - years ). astronomy the scientific study of celestial objects and phenomena, the origins of those objects and phenomena, and their evolution. astrophotography the photography of astronomical objects, celestial events, or areas of the night sky. astrophysics the branch of astronomy that employs principles of physics and chemistry to determine the nature of astronomical objects and phenomena, examining properties such as luminosity, density, temperature, and chemical composition ( rather than the positions or motions of objects in space, which is more specifically the emphasis of celestial mechanics ). atmosphere a gaseous envelope held in place by the gravity of a planet. this shell of gas has no clearly defined exterior boundary, but instead grows increasingly tenuous with altitude. the term can also be applied to a stellar atmosphere, referring to the visible outer layers of a star. axial precession a slow, continuous, gravity - induced change ( a precession ) in the orientation of an astronomical body's axis of rotation. the term often refers in particular to the gradual shift in the orientation of earth's rotational axis with respect to its orbital plane over a cycle of approximately 25, 772 years, which is caused predominantly by the gravitational influence of the moon and the sun on the earth's equatorial bulge. the phenomenon is similar to but much larger in magnitude than other changes in the alignment of earth's axis such as nutation and polar motion, and is the cause of the apparent precession of the equinoxes in the night sky. axial tilt also obliquity. the angle between an object's rotational axis and its orbital axis, or, equivalently, the angle between its equatorial plane and orbital plane. axial tilt usually does not change considerably during a single orbital period ; earth's axial tilt is the cause of the seasons. axial tilt is distinct from orbital inclination. axis of rotation azimuth an angular measurement of an object's orientation along the horizon of the observer, relative to the direction of true north. when combined with the altitude above the horizon, it defines an object's current position in the spherical coordinate system. = = b = = babcock model a model that attempts to explain magnetic and sunspot patterns observed on the sun. barycenter the common center of mass about which any two or more bodies of a gravitationally bound system orbit. the barycenter is one of the foci of the elliptical orbit of each body participating in the system ; its location is strongly influenced by
and modify the lunar regolith is essential to understanding the compositional and structural attributes of other airless planet and asteroid regoliths. other possibilities include extrasolar planets completely covered by oceans, which would lack some earthly processes. = = dynamics = = earth, alone among terrestrial planets, possesses a large moon. this is thought to confer stability to earth's axial tilt, and thus seasons and climates. the closest analogue is the pluto - charon system, though its axial tilt is completely different. both the moon and charon are hypothesized to have formed via giant impacts. giant impacts are hypothesized to account for both the tilt of uranus, and the retrograde rotation of venus. giant impacts are also candidates for the mars ocean hypothesis, and the high density of mercury. most giant planets ( except neptune ) have retinues of moons, rings, ring shepherds, and moon trojans analogous to mini - solar systems. these systems are postulated to have accreted from analogous gas clouds, and possibly with analogous migrations during their formation periods. the cassini mission was defended on the grounds that saturn system dynamics would contribute to studies of solar system dynamics and formation. studies of ring systems inform us of many - body dynamics. this is applicable to the asteroid and kuiper belts, and the early solar system, which had more objects, dust, and gas. it is relevant to the magnetospherics of those bodies. it is also relevant to the dynamics of the milky way galaxy and others. in turn, though the saturnian system is readily studied ( by cassini, ground telescopes, and space telescopes ), the simpler and lower mass ring systems of the other giants makes their explanations somewhat easier to fathom. the jupiter ring system is perhaps more completely understood at present than any of the other three. asteroid families and gaps indicate their local dynamics. they are in turn indicative of the kuiper belt, and its hypothesized kuiper cliff. the hildas and jupiter trojans are then relevant to the neptune trojans and plutinos, twotinos, etc. neptune's relative lack of a moon system suggests its formation and dynamics. the migration of triton explains the ejection or destruction of competing moons, analogous to hot jupiters ( also in sparse systems ), and the grand tack hypothesis of jupiter itself, on a smaller scale. the planets are considered to have formed by accretion of larger and larger particles, into asteroids and
Answer:
|
solar rays
| null |
A planet that revolves around a star is exposed to what?
0. mountains
1. oceans
2. solar rays
3. moons
little is known of satellite systems beyond the solar system, although it is inferred that natural satellites are common. possible signs of exomoons have been detected around exoplanets such as kepler - 1625b. it is also theorised that rogue planets ejected from their planetary system could retain a system of satellites. = = natural formation and evolution = = satellite systems, like planetary systems, are the product of gravitational attraction, but are also sustained through fictitious forces. while the general consensus is that most planetary systems are formed from an accretionary disks, the formation of satellite systems is less clear. the origin of many moons are investigated on a case - by - case basis, and the larger systems are thought to have formed through a combination of one or more processes. = = = system stability = = = the hill sphere is the region in which an astronomical body dominates the attraction of satellites. of the solar system planets, neptune and uranus have the largest hill spheres, due to the lessened gravitational influence of the sun at their far orbits, however all of the giant planets have hill spheres in the vicinity of 100 million kilometres in radius. by contrast, the hill spheres of mercury and ceres, being closer to the sun are quite small. outside of the hill sphere, the sun dominates the gravitational influence, with the exception of the lagrangian points. satellites are stable at the l4 and l5 lagrangian points. these lie at the third corners of the two equilateral triangles in the plane of orbit whose common base is the line between the centers of the two masses, such that the point lies behind ( l5 ) or ahead ( l4 ) of the smaller mass with regard to its orbit around the larger mass. the triangular points ( l4 and l5 ) are stable equilibria, provided that the ratio of m1 / m2 is nearly 24. 96. when a body at these points is perturbed, it moves away from the point, but the factor opposite of that which is increased or decreased by the perturbation ( either gravity or angular momentum - induced speed ) will also increase or decrease, bending the object's path into a stable, kidney - bean - shaped orbit around the point ( as seen in the corotating frame of reference ). it is generally thought that natural satellites should orbit in the same direction as the planet is rotating ( known as prograde orbit ). as such, the terminology regular moon is used for these orbit. however a retrograde
of instability. mars's obliquity is quite variable over millions of years and may be in a chaotic state ; it varies as much as 0Β° to 60Β° over some millions of years, depending on perturbations of the planets. some authors dispute that mars's obliquity is chaotic, and show that tidal dissipation and viscous core - mantle coupling are adequate for it to have reached a fully damped state, similar to mercury and venus. the occasional shifts in the axial tilt of mars have been suggested as an explanation for the appearance and disappearance of rivers and lakes over the course of the existence of mars. a shift could cause a burst of methane into the atmosphere, causing warming, but then the methane would be destroyed and the climate would become arid again. the obliquities of the outer planets are considered relatively stable. = = extrasolar planets = = the stellar obliquity Οs, i. e. the axial tilt of a star with respect to the orbital plane of one of its planets, has been determined for only a few systems. by 2012, 49 stars have had sky - projected spin - orbit misalignment Ξ» has been observed, which serves as a lower limit to Οs. most of these measurements rely on the rossiter β mclaughlin effect. as of 2024 the axial tilt of 4 exoplanets have been measured with one of them vhs 1256 b having a uranus like tilt of 90 degrees Β± 25 degrees. astrophysicists have applied tidal theories to predict the obliquity of extrasolar planets. it has been shown that the obliquities of exoplanets in the habitable zone around low - mass stars tend to be eroded in less than a billion years, which means that they would not have tilt - induced seasons as earth has. = = see also = = axial parallelism milankovitch cycles polar motion pole shift rotation around a fixed axis true polar wander = = references = = = = external links = = national space science data center seidelmann, p. kenneth ; archinal, brent a. ; a'hearn, michael f. ; et al. ( 2007 ). " report of the iau / iag working group on cartographic coordinates and rotational elements : 2006 ". celestial mechanics and dynamical astronomy. 98 ( 3 ) : 155 β 180. bibcode : 2007cemda.. 98.. 155s. doi : 10. 1007 / s10
the gravity of the sun. all planetary moons and rings are located well inside the hill sphere and orbit the corresponding planet. gravitational interactions between such satellites can be seen, e. g., in the stable 1 : 2 : 4 orbital resonance of jupiter's moons ganymede, europa and io. also subdivisions and structures within the rings of saturn are caused by resonances with satellites. e. g. the gap between the inner b ring and the outer a ring has been cleared by a 2 : 1 resonance with the moon mimas. also some narrow discrete rings of saturn, uranus, and neptune like saturn's f ring are shaped and held in place by the gravity of one or two shepherd moons. = = = solar radiation pressure effects = = = solar radiation exerts the repulsive radiation pressure force fr on meteoroids and interplanetary dust particles : f r = l q p r a 4 Ο r 2 c, { \ displaystyle f _ { r } = { { l _ { \ odot } q _ { pr } a } \ over { 4 \ pi r ^ { 2 } c } }, } where l { \ displaystyle { l _ { \ odot } } } is the solar luminosity or l 4 Ο r 2 { \ displaystyle l _ { \ odot } \ over { 4 \ pi r ^ { 2 } } } is the solar irradiance at heliocentric distance r, q p r { \ displaystyle q _ { \ rm { pr } } } is the radiation pressure coefficient of the particle, a { \ displaystyle a } is the cross section ( for spherical particles a = Ο s 2 { \ displaystyle a = \ pi s ^ { 2 } } with particle radius s { \ displaystyle s } ), c { \ displaystyle c } is the speed of light. the radiation pressure coefficient, q p r { \ displaystyle q _ { \ rm { pr } } }, depends on optical properties of the particle like absorption, reflection, and light scattering integrated over all wavelengths of the solar spectrum. it can be calculated by using e. g. mie theorie, discrete dipole approximation, or even microwave analog experiments. solar radiation pressure reduces the effective force of gravity on a dust particle and is characterized by the dimensionless parameter Ξ² { \ displaystyle \ beta }, the ratio of the radiation pressure force f r { \ displaystyle f _ { r } } to the force of gravity
5813Γ10β5 light - years ). astronomy the scientific study of celestial objects and phenomena, the origins of those objects and phenomena, and their evolution. astrophotography the photography of astronomical objects, celestial events, or areas of the night sky. astrophysics the branch of astronomy that employs principles of physics and chemistry to determine the nature of astronomical objects and phenomena, examining properties such as luminosity, density, temperature, and chemical composition ( rather than the positions or motions of objects in space, which is more specifically the emphasis of celestial mechanics ). atmosphere a gaseous envelope held in place by the gravity of a planet. this shell of gas has no clearly defined exterior boundary, but instead grows increasingly tenuous with altitude. the term can also be applied to a stellar atmosphere, referring to the visible outer layers of a star. axial precession a slow, continuous, gravity - induced change ( a precession ) in the orientation of an astronomical body's axis of rotation. the term often refers in particular to the gradual shift in the orientation of earth's rotational axis with respect to its orbital plane over a cycle of approximately 25, 772 years, which is caused predominantly by the gravitational influence of the moon and the sun on the earth's equatorial bulge. the phenomenon is similar to but much larger in magnitude than other changes in the alignment of earth's axis such as nutation and polar motion, and is the cause of the apparent precession of the equinoxes in the night sky. axial tilt also obliquity. the angle between an object's rotational axis and its orbital axis, or, equivalently, the angle between its equatorial plane and orbital plane. axial tilt usually does not change considerably during a single orbital period ; earth's axial tilt is the cause of the seasons. axial tilt is distinct from orbital inclination. axis of rotation azimuth an angular measurement of an object's orientation along the horizon of the observer, relative to the direction of true north. when combined with the altitude above the horizon, it defines an object's current position in the spherical coordinate system. = = b = = babcock model a model that attempts to explain magnetic and sunspot patterns observed on the sun. barycenter the common center of mass about which any two or more bodies of a gravitationally bound system orbit. the barycenter is one of the foci of the elliptical orbit of each body participating in the system ; its location is strongly influenced by
and modify the lunar regolith is essential to understanding the compositional and structural attributes of other airless planet and asteroid regoliths. other possibilities include extrasolar planets completely covered by oceans, which would lack some earthly processes. = = dynamics = = earth, alone among terrestrial planets, possesses a large moon. this is thought to confer stability to earth's axial tilt, and thus seasons and climates. the closest analogue is the pluto - charon system, though its axial tilt is completely different. both the moon and charon are hypothesized to have formed via giant impacts. giant impacts are hypothesized to account for both the tilt of uranus, and the retrograde rotation of venus. giant impacts are also candidates for the mars ocean hypothesis, and the high density of mercury. most giant planets ( except neptune ) have retinues of moons, rings, ring shepherds, and moon trojans analogous to mini - solar systems. these systems are postulated to have accreted from analogous gas clouds, and possibly with analogous migrations during their formation periods. the cassini mission was defended on the grounds that saturn system dynamics would contribute to studies of solar system dynamics and formation. studies of ring systems inform us of many - body dynamics. this is applicable to the asteroid and kuiper belts, and the early solar system, which had more objects, dust, and gas. it is relevant to the magnetospherics of those bodies. it is also relevant to the dynamics of the milky way galaxy and others. in turn, though the saturnian system is readily studied ( by cassini, ground telescopes, and space telescopes ), the simpler and lower mass ring systems of the other giants makes their explanations somewhat easier to fathom. the jupiter ring system is perhaps more completely understood at present than any of the other three. asteroid families and gaps indicate their local dynamics. they are in turn indicative of the kuiper belt, and its hypothesized kuiper cliff. the hildas and jupiter trojans are then relevant to the neptune trojans and plutinos, twotinos, etc. neptune's relative lack of a moon system suggests its formation and dynamics. the migration of triton explains the ejection or destruction of competing moons, analogous to hot jupiters ( also in sparse systems ), and the grand tack hypothesis of jupiter itself, on a smaller scale. the planets are considered to have formed by accretion of larger and larger particles, into asteroids and
Answer:
|
oceans
| 0.3 |
Which is successful reproduction?
0. A clay tablet splits into two identical halves
1. A bird chirps to its mate
2. A doe runs beside her fawn
3. A smaller iceberg splits from a larger one
the " vicar of bray " hypothesis ( or fisher - muller model ) attempts to explain why sexual reproduction might have advantages over asexual reproduction. reproduction is the process by which organisms give rise to offspring. asexual reproduction involves a single parent and results in offspring that are genetically identical to each other and to the parent. in contrast to asexual reproduction, sexual reproduction involves two parents. both the parents produce gametes through meiosis, a special type of cell division that reduces the chromosome number by half. during an early stage of meiosis, before the chromosomes are separated in the two daughter cells, the chromosomes undergo genetic recombination. this allows them to exchange some of their genetic information. therefore, the gametes from a single organism are all genetically different from each other. the process in which the two gametes from the two parents unite is called fertilization. half of the genetic information from both parents is combined. this results in offspring that are genetically different from each other and from the parents. in short, sexual reproduction allows a continuous rearrangement of genes. therefore, the offspring of a population of sexually reproducing individuals will show a more varied selection of phenotypes. due to faster attainment of favorable genetic combinations, sexually reproducing populations evolve more rapidly in response to environmental changes. under the vicar of bray hypothesis, sex benefits a population as a whole, but not individuals within it, making it a case of group selection. = = origin of the name'vicar of bray'= = the hypothesis is called after the vicar of bray, a semi - fictionalized cleric who retained his ecclesiastic office by quickly adapting to the prevailing religious winds in england, switching between various protestant and catholic rites as the ruling hierarchy changed. the figure described was simon aleyn between 1540 and 1588. the main work of thomas fuller ( d. 1661 ), worthies of england, describes this man : the vivacious vicar [ of bray ] living under king henry viii, king edward vi, queen mary, and queen elizabeth, was first a papist, then a protestant, then a papist, then a protestant again. he had seen some martyrs burnt ( two miles off ) at windsor and found this fire too hot for his tender temper. this vicar, being taxed [ attacked ] by one for being a turncoat and an inconstant changeling, said, " not so, for i always kept my principle, which is this β to live and die
, male reproductive success began to fall. female reproductive success also increased with number of mates, but much more gradually than that of the males. the second series of data collected in sets five and six illustrated a dramatically different outcome. male reproductive success increased at a steady and steep rate, never dropping. female reproductive success, on the other hand, plateaued after a single mate. bateman focused mainly on the second series of data when discussing his results. his main conclusion was that the reproductive success of females does not increase with an influx of mates, as one fit mate was enough to successfully complete fertilization. this is often referred to as bateman's gradient. = = replication of bateman's experiments = = throughout 2012 and 2013, gowaty, kim, and anderson repeated bateman's experiment in its entirety, staying as close to bateman's published methodology as possible. they found that upon combining certain fly strains with one another, the offspring were unable to survive to adulthood. thus, bateman's results regarding the number of individuals not having mated was too high. this was valid for both the males and females. gowaty desired to further explore the reasoning behind the premature death of the drosophila. she began doing so by running monogamy trials between different strains of flies and found that 25 % of the offspring died due to becoming double mutants. bateman thought his work fit within the lines of mendel's laws of genetics, while gowaty proved otherwise. the 1948 experiments inferred reproductive success based on the number of adults living by the end of the trial. in reality, many factors were left out of the equation when calculating reproductive success as a function of the number of mates, which had the ability to completely dislodge the accuracy behind bateman's results. gowaty was not able to confirm bateman's conclusions and found no evidence for sexual selection in the experiment. = = related experiments = = nevertheless, some modern experiments between the relationship of number of mates and the reproductive success of males and females support bateman's principle. julie collet conducted an experiment with a population of red jungle fowl. a total of thirteen replicate groups of three males and four females were monitored for ten days. in this experiment, the sex ratio was biased toward females. a male's reproductive success was calculated using the proportion of embryos fathered to the total number of embryos produced by all the females he mated with. the total sexual selection opportunity was calculated
##eiotic endomitosis in unisexual vertebrates = = the unisexual salamanders ( genus ambystoma ) are the oldest known unisexual vertebrate lineage, having arisen about 5 million years ago. in these polyploid unisexual females, an extra premeiotic endomitotic replication of the genome, doubles the number of chromosomes. as a result, the mature eggs that are produced subsequent to the two meiotic divisions have the same ploidy as the somatic cells of the adult female salamander. synapsis and recombination during meiotic prophase i in these unisexual females is thought to ordinarily occur between identical sister chromosomes and occasionally between homologous chromosomes. thus little, if any, genetic variation is produced. recombination between homeologous chromosomes occurs rarely, if at all. = = references = =
of their parents because the cells of the offspring contain copies of the genes in their parents'cells. in asexually reproducing organisms, the offspring will be a genetic copy or clone of the parent organism. in sexually reproducing organisms, a specialized form of cell division called meiosis produces cells called gametes or germ cells that are haploid, or contain only one copy of each gene. : 20. 2 the gametes produced by females are called eggs or ova, and those produced by males are called sperm. two gametes fuse to form a diploid fertilized egg, a single cell that has two sets of genes, with one copy of each gene from the mother and one from the father. : 20 during the process of meiotic cell division, an event called genetic recombination or crossing - over can sometimes occur, in which a length of dna on one chromatid is swapped with a length of dna on the corresponding homologous non - sister chromatid. this can result in reassortment of otherwise linked alleles. : 5. 5 the mendelian principle of independent assortment asserts that each of a parent's two genes for each trait will sort independently into gametes ; which allele an organism inherits for one trait is unrelated to which allele it inherits for another trait. this is in fact only true for genes that do not reside on the same chromosome or are located very far from one another on the same chromosome. the closer two genes lie on the same chromosome, the more closely they will be associated in gametes and the more often they will appear together ( known as genetic linkage ). genes that are very close are essentially never separated because it is extremely unlikely that a crossover point will occur between them. = = genome = = the genome is the total genetic material of an organism and includes both the genes and non - coding sequences. eukaryotic genes can be annotated using finder. = = = number of genes = = = the genome size, and the number of genes it encodes varies widely between organisms. the smallest genomes occur in viruses, and viroids ( which act as a single non - coding rna gene ). conversely, plants can have extremely large genomes, with rice containing > 46, 000 protein - coding genes. the total number of protein - coding genes ( the earth's proteome ) is estimated to be 5 million sequences. although the number of base - pairs of
external ectoderm and an internal endoderm. in most cases, a third germ layer, the mesoderm, also develops between them. these germ layers then differentiate to form tissues and organs. repeated instances of mating with a close relative during sexual reproduction generally leads to inbreeding depression within a population due to the increased prevalence of harmful recessive traits. animals have evolved numerous mechanisms for avoiding close inbreeding. some animals are capable of asexual reproduction, which often results in a genetic clone of the parent. this may take place through fragmentation ; budding, such as in hydra and other cnidarians ; or parthenogenesis, where fertile eggs are produced without mating, such as in aphids. = = ecology = = animals are categorised into ecological groups depending on their trophic levels and how they consume organic material. such groupings include carnivores ( further divided into subcategories such as piscivores, insectivores, ovivores, etc. ), herbivores ( subcategorised into folivores, graminivores, frugivores, granivores, nectarivores, algivores, etc. ), omnivores, fungivores, scavengers / detritivores, and parasites. interactions between animals of each biome form complex food webs within that ecosystem. in carnivorous or omnivorous species, predation is a consumer β resource interaction where the predator feeds on another organism, its prey, who often evolves anti - predator adaptations to avoid being fed upon. selective pressures imposed on one another lead to an evolutionary arms race between predator and prey, resulting in various antagonistic / competitive coevolutions. almost all multicellular predators are animals. some consumers use multiple methods ; for example, in parasitoid wasps, the larvae feed on the hosts'living tissues, killing them in the process, but the adults primarily consume nectar from flowers. other animals may have very specific feeding behaviours, such as hawksbill sea turtles which mainly eat sponges. most animals rely on biomass and bioenergy produced by plants and phytoplanktons ( collectively called producers ) through photosynthesis. herbivores, as primary consumers, eat the plant material directly to digest and absorb the nutrients, while carnivores and other animals on higher trophic levels indirectly acquire the nutrients by eating the herbivores or other animals that have
Answer:
|
A doe runs beside her fawn
| null |
Which is successful reproduction?
0. A clay tablet splits into two identical halves
1. A bird chirps to its mate
2. A doe runs beside her fawn
3. A smaller iceberg splits from a larger one
the " vicar of bray " hypothesis ( or fisher - muller model ) attempts to explain why sexual reproduction might have advantages over asexual reproduction. reproduction is the process by which organisms give rise to offspring. asexual reproduction involves a single parent and results in offspring that are genetically identical to each other and to the parent. in contrast to asexual reproduction, sexual reproduction involves two parents. both the parents produce gametes through meiosis, a special type of cell division that reduces the chromosome number by half. during an early stage of meiosis, before the chromosomes are separated in the two daughter cells, the chromosomes undergo genetic recombination. this allows them to exchange some of their genetic information. therefore, the gametes from a single organism are all genetically different from each other. the process in which the two gametes from the two parents unite is called fertilization. half of the genetic information from both parents is combined. this results in offspring that are genetically different from each other and from the parents. in short, sexual reproduction allows a continuous rearrangement of genes. therefore, the offspring of a population of sexually reproducing individuals will show a more varied selection of phenotypes. due to faster attainment of favorable genetic combinations, sexually reproducing populations evolve more rapidly in response to environmental changes. under the vicar of bray hypothesis, sex benefits a population as a whole, but not individuals within it, making it a case of group selection. = = origin of the name'vicar of bray'= = the hypothesis is called after the vicar of bray, a semi - fictionalized cleric who retained his ecclesiastic office by quickly adapting to the prevailing religious winds in england, switching between various protestant and catholic rites as the ruling hierarchy changed. the figure described was simon aleyn between 1540 and 1588. the main work of thomas fuller ( d. 1661 ), worthies of england, describes this man : the vivacious vicar [ of bray ] living under king henry viii, king edward vi, queen mary, and queen elizabeth, was first a papist, then a protestant, then a papist, then a protestant again. he had seen some martyrs burnt ( two miles off ) at windsor and found this fire too hot for his tender temper. this vicar, being taxed [ attacked ] by one for being a turncoat and an inconstant changeling, said, " not so, for i always kept my principle, which is this β to live and die
, male reproductive success began to fall. female reproductive success also increased with number of mates, but much more gradually than that of the males. the second series of data collected in sets five and six illustrated a dramatically different outcome. male reproductive success increased at a steady and steep rate, never dropping. female reproductive success, on the other hand, plateaued after a single mate. bateman focused mainly on the second series of data when discussing his results. his main conclusion was that the reproductive success of females does not increase with an influx of mates, as one fit mate was enough to successfully complete fertilization. this is often referred to as bateman's gradient. = = replication of bateman's experiments = = throughout 2012 and 2013, gowaty, kim, and anderson repeated bateman's experiment in its entirety, staying as close to bateman's published methodology as possible. they found that upon combining certain fly strains with one another, the offspring were unable to survive to adulthood. thus, bateman's results regarding the number of individuals not having mated was too high. this was valid for both the males and females. gowaty desired to further explore the reasoning behind the premature death of the drosophila. she began doing so by running monogamy trials between different strains of flies and found that 25 % of the offspring died due to becoming double mutants. bateman thought his work fit within the lines of mendel's laws of genetics, while gowaty proved otherwise. the 1948 experiments inferred reproductive success based on the number of adults living by the end of the trial. in reality, many factors were left out of the equation when calculating reproductive success as a function of the number of mates, which had the ability to completely dislodge the accuracy behind bateman's results. gowaty was not able to confirm bateman's conclusions and found no evidence for sexual selection in the experiment. = = related experiments = = nevertheless, some modern experiments between the relationship of number of mates and the reproductive success of males and females support bateman's principle. julie collet conducted an experiment with a population of red jungle fowl. a total of thirteen replicate groups of three males and four females were monitored for ten days. in this experiment, the sex ratio was biased toward females. a male's reproductive success was calculated using the proportion of embryos fathered to the total number of embryos produced by all the females he mated with. the total sexual selection opportunity was calculated
##eiotic endomitosis in unisexual vertebrates = = the unisexual salamanders ( genus ambystoma ) are the oldest known unisexual vertebrate lineage, having arisen about 5 million years ago. in these polyploid unisexual females, an extra premeiotic endomitotic replication of the genome, doubles the number of chromosomes. as a result, the mature eggs that are produced subsequent to the two meiotic divisions have the same ploidy as the somatic cells of the adult female salamander. synapsis and recombination during meiotic prophase i in these unisexual females is thought to ordinarily occur between identical sister chromosomes and occasionally between homologous chromosomes. thus little, if any, genetic variation is produced. recombination between homeologous chromosomes occurs rarely, if at all. = = references = =
of their parents because the cells of the offspring contain copies of the genes in their parents'cells. in asexually reproducing organisms, the offspring will be a genetic copy or clone of the parent organism. in sexually reproducing organisms, a specialized form of cell division called meiosis produces cells called gametes or germ cells that are haploid, or contain only one copy of each gene. : 20. 2 the gametes produced by females are called eggs or ova, and those produced by males are called sperm. two gametes fuse to form a diploid fertilized egg, a single cell that has two sets of genes, with one copy of each gene from the mother and one from the father. : 20 during the process of meiotic cell division, an event called genetic recombination or crossing - over can sometimes occur, in which a length of dna on one chromatid is swapped with a length of dna on the corresponding homologous non - sister chromatid. this can result in reassortment of otherwise linked alleles. : 5. 5 the mendelian principle of independent assortment asserts that each of a parent's two genes for each trait will sort independently into gametes ; which allele an organism inherits for one trait is unrelated to which allele it inherits for another trait. this is in fact only true for genes that do not reside on the same chromosome or are located very far from one another on the same chromosome. the closer two genes lie on the same chromosome, the more closely they will be associated in gametes and the more often they will appear together ( known as genetic linkage ). genes that are very close are essentially never separated because it is extremely unlikely that a crossover point will occur between them. = = genome = = the genome is the total genetic material of an organism and includes both the genes and non - coding sequences. eukaryotic genes can be annotated using finder. = = = number of genes = = = the genome size, and the number of genes it encodes varies widely between organisms. the smallest genomes occur in viruses, and viroids ( which act as a single non - coding rna gene ). conversely, plants can have extremely large genomes, with rice containing > 46, 000 protein - coding genes. the total number of protein - coding genes ( the earth's proteome ) is estimated to be 5 million sequences. although the number of base - pairs of
external ectoderm and an internal endoderm. in most cases, a third germ layer, the mesoderm, also develops between them. these germ layers then differentiate to form tissues and organs. repeated instances of mating with a close relative during sexual reproduction generally leads to inbreeding depression within a population due to the increased prevalence of harmful recessive traits. animals have evolved numerous mechanisms for avoiding close inbreeding. some animals are capable of asexual reproduction, which often results in a genetic clone of the parent. this may take place through fragmentation ; budding, such as in hydra and other cnidarians ; or parthenogenesis, where fertile eggs are produced without mating, such as in aphids. = = ecology = = animals are categorised into ecological groups depending on their trophic levels and how they consume organic material. such groupings include carnivores ( further divided into subcategories such as piscivores, insectivores, ovivores, etc. ), herbivores ( subcategorised into folivores, graminivores, frugivores, granivores, nectarivores, algivores, etc. ), omnivores, fungivores, scavengers / detritivores, and parasites. interactions between animals of each biome form complex food webs within that ecosystem. in carnivorous or omnivorous species, predation is a consumer β resource interaction where the predator feeds on another organism, its prey, who often evolves anti - predator adaptations to avoid being fed upon. selective pressures imposed on one another lead to an evolutionary arms race between predator and prey, resulting in various antagonistic / competitive coevolutions. almost all multicellular predators are animals. some consumers use multiple methods ; for example, in parasitoid wasps, the larvae feed on the hosts'living tissues, killing them in the process, but the adults primarily consume nectar from flowers. other animals may have very specific feeding behaviours, such as hawksbill sea turtles which mainly eat sponges. most animals rely on biomass and bioenergy produced by plants and phytoplanktons ( collectively called producers ) through photosynthesis. herbivores, as primary consumers, eat the plant material directly to digest and absorb the nutrients, while carnivores and other animals on higher trophic levels indirectly acquire the nutrients by eating the herbivores or other animals that have
Answer:
|
A bird chirps to its mate
| 0.3 |
The only way for mammals to have a family is to
0. steal children
1. adopt
2. lay eggs
3. reproduce
evident costs. it has been observed in over 120 mammal and 150 bird species. it is a defining feature of eusociality, which is found in insects, including various ants, bees, and termites. for mammalian mothers, alloparenting may be beneficial in promoting earlier weaning of infants ( as long as earlier weaning does not compromise infant survival ). this strategy results in shorter inter - birth intervals and increased reproductive success. frequent alloparenting may provide mothers more opportunities to feed without their young, which may ultimately increase their net energy gains and permits them to invest more energy in milk synthesis. however, potential costs of alloparenting may include the expenditure of time and resources in caring for non - descendant offspring with no apparent direct benefits to alloparents. the offspring that experience alloparental care may benefit from increased protection from predators and the learning of group dynamics through social interactions. in the eusocial insects, the evolution of a caste system has driven workers to sacrifice their own personal reproductive fitness to assist in the reproductive success of the colony. indirect fitness benefits are gained instead through assisting related members of the colony. it may be in the best interest of a worker to forgo her own personal reproduction and participate in alloparenting, or rearing drones, so that there is an enhanced likelihood that males from her colony will ultimately mate with a queen. this would provide a greater chance for her colony's genes to be represented in the future colony. similarly, worker ants tend to raise their sisters rather than their daughters, due to their greater relatedness. the survival of the colony is believed to be the main reward that drives the altruism of the workers. = = in groups of animals = = = = = invertebrates = = = parental care is not frequently observed in invertebrate species. in dipterans, oviposition is instead commonly observed. adults lay their eggs before leaving them to hatch and develop into larva, then pupa, then adults. for example, phormia regina adults lay their eggs preferentially on carrion and corpses. though biparental and male - only care are rarely observed, female - only care does exist in some invertebrates. some insects, including the hymenoptera ( ants, bees and wasps ), invest substantial effort in caring for their young. the type and amount of care invested varies widely. solitary wasps such as the potter wasps ( eumeninae ) build nests for their young, provisioning them with food
that gives the probability that at a random locus, the alleles there will be identical by descent. modern formulations of the rule use alan grafen's definition of relatedness based on the theory of linear regression. a 2014 review of many lines of evidence for hamilton's rule found that its predictions were confirmed in a wide variety of social behaviours across a broad phylogenetic range of birds, mammals and insects, in each case comparing social and non - social taxa. among the experimental findings, a 2010 study used a wild population of red squirrels in yukon, canada. surrogate mothers adopted related orphaned squirrel pups but not unrelated orphans. the cost of adoption was calculated by measuring a decrease in the survival probability of the entire litter after increasing the litter by one pup, while benefit was measured as the increased chance of survival of the orphan. the degree of relatedness of the orphan and surrogate mother for adoption to occur depended on the number of pups the surrogate mother already had in her nest, as this affected the cost of adoption. females always adopted orphans when rb was greater than c, but never adopted when rb was less than c, supporting hamilton's rule. = = mechanisms = = altruism occurs where the instigating individual suffers a fitness loss while the receiving individual experiences a fitness gain. the sacrifice of one individual to help another is an example. hamilton outlined two ways in which kin selection altruism could be favoured : the selective advantage which makes behaviour conditional in the right sense on the discrimination of factors which correlate with the relationship of the individual concerned is therefore obvious. it may be, for instance, that in respect of a certain social action performed towards neighbours indiscriminately, an individual is only just breaking even in terms of inclusive fitness. if he could learn to recognise those of his neighbours who really were close relatives and could devote his beneficial actions to them alone an advantage to inclusive fitness would at once appear. thus a mutation causing such discriminatory behaviour itself benefits inclusive fitness and would be selected. in fact, the individual may not need to perform any discrimination so sophisticated as we suggest here ; a difference in the generosity of his behaviour according to whether the situations evoking it were encountered near to, or far from, his own home might occasion an advantage of a similar kind. = = = kin recognition and the green beard effect = = = first, if individuals have the capacity to recognise kin and to discriminate ( positively ) on the basis of kinship, then the average relatedness of
tasmanian devil populations in captivity compared to allowing for group mate choice. this helped increase the populations reproductive success in captivity and saw less inbreeding depression within the population. using intensive housing to help establish a genetically healthy population in captivity can allow facilities to further increase conservation efforts of a species and combat genetic issues that may arise in the captive population. = = new technologies = = = = = assisted reproduction technology ( art ) : artificial insemination = = = getting captive wild animals to breed naturally can be a difficult task. giant pandas for example lose interest in mating once they are captured, and female giant pandas only experience estrus once a year, which only lasts for 48 to 72 hours. many researchers have turned to artificial insemination in an attempt to increase the populations of endangered animals. it may be used for many reasons, including to overcome physical breeding difficulties, to allow a male to inseminate a much larger number of females, to control the paternity of offspring, and to avoid injury incurred during natural mating. it also creates more genetically diverse captive populations, enabling captive facilities to easily share genetic material with each other without the need to move animals. scientist of the justus - liebig - university of giessen, germany, from the working group of michael lierz, developed a novel technique for semen collection and artificial insemination in parrots producing the world's first macaw by assisted reproduction. = = = cryopreservation = = = animal species can be preserved in gene banks, which consist of a cryogenic facilities used to store live sperm, eggs, or embryos in ultracold conditions. the zoological society of san diego has established a " frozen zoo " to store frozen tissue from the world's rarest and most endangered species samples using cryopreservation techniques. at present, there has been more than 355 species, including mammals, reptiles, and birds. cryopreservation can be performed as oocyte cryopreservation before fertilization, or as embryo cryopreservation after fertilization. cryogenically preserved specimens can potentially be used to revive breeds that are endangered or extinct, for breed improvement, crossbreeding, research and development. this method can be used for virtually indefinite storage of material without deterioration over a much greater time - period relative to all other methods of ex situ conservation. however, cryo - conservation can be an expensive strategy and requires long term hygienic and economic commitment for germplas
from threats such as predators, but a prolonged period of support during which the child learns whatever is needed to live successfully in human society. = = in evolutionary biology = = in evolutionary biology, parental investment is the expenditure of time and effort towards rearing offspring that benefits the offspring's evolutionary fitness at a cost to parents'ability to invest in other components of the species'fitness. parental care requires resources from one or both parents that increases the fitness of their offspring and of themselves. these resources thus cannot be invested in the parents own survival, growth or future reproduction. therefore, parental care will only evolve in a species that requires care. some animal groups produce self - sufficient young and thus no parental care is required. for species that do require care, trade - offs exist in regards to where parental investment should be directed and how much care should be provided, since resources and time are limited. for example, if the strategy of parental care involves parents choosing to give each of a relatively small number of offspring an increased chance of surviving to reproduce themselves, they may accordingly have evolved to produce a small number of zygotes at a time, possibly only one. the ideal amount of parental investment would guarantee the survival and quality of both broods. parents need to trade off investment into current and future reproductive events, since parental care increases offspring survival at the expense of the parent's ability to invest in future broods. nonetheless, there is some evidence suggesting that in mammals provinding male care actually leads to more fecund females, and thus caring for the offspring can lead to having more number of litters. predation on offspring and species habitat - type are two potential proximate causes for the evolution of parental care. generally, parental care is expected to evolve from a previous state of no care when the costs of providing care are outweighed by the benefits to a caring parent. for example, if the benefit of increased offspring survival or quality exceed the decreased chance of survival and future reproductive success of the parent, then parental care may evolve. therefore, parental care is favoured when it is required by offspring, and the benefits of care are high. types of parental care and the amount of resources invested by parents vary considerably across the animal kingdom. the evolution of male - only, female - only, biparental or alloparental care in different groups of animals may be driven by multiple factors. firstly, different groups may have diverse physiological or evolutionary constraints that may predispose one sex to care more than the other. for example
parental care is a behavioural and evolutionary strategy adopted by some animals, involving a parental investment being made to the evolutionary fitness of offspring. patterns of parental care are widespread and highly diverse across the animal kingdom. there is great variation in different animal groups in terms of how parents care for offspring, and the amount of resources invested by parents. for example, there may be considerable variation in the amount of care invested by each sex, where females may invest more in some species, males invest more in others, or investment may be shared equally. numerous hypotheses have been proposed to describe this variation and patterns in parental care that exist between the sexes, as well as among species. parental care is any behaviour that contributes to offspring survival, such as building a nest, provisioning offspring with food, or defending offspring from predators. reptiles may produce self - sufficient young needing no parental care, while some hatchling birds may be helpless at birth, relying on their parents for survival. parental care is beneficial if it increases the parent's inclusive fitness, such as by improving offspring survival, quality, or reproductive success. since parental care is costly and often affects the parent's own future survival and reproductive success, parents ensure that any investment is well - spent. parental care thus only evolves where it is adaptive. types of parental care include maternal or paternal care, biparental care and alloparental care. sexual conflict is known to occur over mating, and further familial conflicts may continue after mating when there is parental care of the eggs or young. for example, conflict may arise between male and female parents over how much care each should provide, conflict may arise between siblings over how much care each should demand, and conflicts may arise between parents and offspring over the supply and demand of care. although parental care increases the evolutionary fitness of the offspring receiving the care, it produces a cost for the parent organism as energy is expended on caring for the offspring, and mating opportunities may be lost. as this is costly, it only evolves from a when the costs are outweighed by the benefits. parental care is seen in many insects, notably the social insects such as ants, bees and wasps ; in certain fishes, such as the mouthbrooders ; widely in birds ; in amphibians ; rarely in reptiles and especially widely in mammals, which share two major adaptations for care of the young, namely gestation ( development of the embryo inside the mother's body ) and production of milk. = = types = =
Answer:
|
reproduce
| null |
The only way for mammals to have a family is to
0. steal children
1. adopt
2. lay eggs
3. reproduce
evident costs. it has been observed in over 120 mammal and 150 bird species. it is a defining feature of eusociality, which is found in insects, including various ants, bees, and termites. for mammalian mothers, alloparenting may be beneficial in promoting earlier weaning of infants ( as long as earlier weaning does not compromise infant survival ). this strategy results in shorter inter - birth intervals and increased reproductive success. frequent alloparenting may provide mothers more opportunities to feed without their young, which may ultimately increase their net energy gains and permits them to invest more energy in milk synthesis. however, potential costs of alloparenting may include the expenditure of time and resources in caring for non - descendant offspring with no apparent direct benefits to alloparents. the offspring that experience alloparental care may benefit from increased protection from predators and the learning of group dynamics through social interactions. in the eusocial insects, the evolution of a caste system has driven workers to sacrifice their own personal reproductive fitness to assist in the reproductive success of the colony. indirect fitness benefits are gained instead through assisting related members of the colony. it may be in the best interest of a worker to forgo her own personal reproduction and participate in alloparenting, or rearing drones, so that there is an enhanced likelihood that males from her colony will ultimately mate with a queen. this would provide a greater chance for her colony's genes to be represented in the future colony. similarly, worker ants tend to raise their sisters rather than their daughters, due to their greater relatedness. the survival of the colony is believed to be the main reward that drives the altruism of the workers. = = in groups of animals = = = = = invertebrates = = = parental care is not frequently observed in invertebrate species. in dipterans, oviposition is instead commonly observed. adults lay their eggs before leaving them to hatch and develop into larva, then pupa, then adults. for example, phormia regina adults lay their eggs preferentially on carrion and corpses. though biparental and male - only care are rarely observed, female - only care does exist in some invertebrates. some insects, including the hymenoptera ( ants, bees and wasps ), invest substantial effort in caring for their young. the type and amount of care invested varies widely. solitary wasps such as the potter wasps ( eumeninae ) build nests for their young, provisioning them with food
that gives the probability that at a random locus, the alleles there will be identical by descent. modern formulations of the rule use alan grafen's definition of relatedness based on the theory of linear regression. a 2014 review of many lines of evidence for hamilton's rule found that its predictions were confirmed in a wide variety of social behaviours across a broad phylogenetic range of birds, mammals and insects, in each case comparing social and non - social taxa. among the experimental findings, a 2010 study used a wild population of red squirrels in yukon, canada. surrogate mothers adopted related orphaned squirrel pups but not unrelated orphans. the cost of adoption was calculated by measuring a decrease in the survival probability of the entire litter after increasing the litter by one pup, while benefit was measured as the increased chance of survival of the orphan. the degree of relatedness of the orphan and surrogate mother for adoption to occur depended on the number of pups the surrogate mother already had in her nest, as this affected the cost of adoption. females always adopted orphans when rb was greater than c, but never adopted when rb was less than c, supporting hamilton's rule. = = mechanisms = = altruism occurs where the instigating individual suffers a fitness loss while the receiving individual experiences a fitness gain. the sacrifice of one individual to help another is an example. hamilton outlined two ways in which kin selection altruism could be favoured : the selective advantage which makes behaviour conditional in the right sense on the discrimination of factors which correlate with the relationship of the individual concerned is therefore obvious. it may be, for instance, that in respect of a certain social action performed towards neighbours indiscriminately, an individual is only just breaking even in terms of inclusive fitness. if he could learn to recognise those of his neighbours who really were close relatives and could devote his beneficial actions to them alone an advantage to inclusive fitness would at once appear. thus a mutation causing such discriminatory behaviour itself benefits inclusive fitness and would be selected. in fact, the individual may not need to perform any discrimination so sophisticated as we suggest here ; a difference in the generosity of his behaviour according to whether the situations evoking it were encountered near to, or far from, his own home might occasion an advantage of a similar kind. = = = kin recognition and the green beard effect = = = first, if individuals have the capacity to recognise kin and to discriminate ( positively ) on the basis of kinship, then the average relatedness of
tasmanian devil populations in captivity compared to allowing for group mate choice. this helped increase the populations reproductive success in captivity and saw less inbreeding depression within the population. using intensive housing to help establish a genetically healthy population in captivity can allow facilities to further increase conservation efforts of a species and combat genetic issues that may arise in the captive population. = = new technologies = = = = = assisted reproduction technology ( art ) : artificial insemination = = = getting captive wild animals to breed naturally can be a difficult task. giant pandas for example lose interest in mating once they are captured, and female giant pandas only experience estrus once a year, which only lasts for 48 to 72 hours. many researchers have turned to artificial insemination in an attempt to increase the populations of endangered animals. it may be used for many reasons, including to overcome physical breeding difficulties, to allow a male to inseminate a much larger number of females, to control the paternity of offspring, and to avoid injury incurred during natural mating. it also creates more genetically diverse captive populations, enabling captive facilities to easily share genetic material with each other without the need to move animals. scientist of the justus - liebig - university of giessen, germany, from the working group of michael lierz, developed a novel technique for semen collection and artificial insemination in parrots producing the world's first macaw by assisted reproduction. = = = cryopreservation = = = animal species can be preserved in gene banks, which consist of a cryogenic facilities used to store live sperm, eggs, or embryos in ultracold conditions. the zoological society of san diego has established a " frozen zoo " to store frozen tissue from the world's rarest and most endangered species samples using cryopreservation techniques. at present, there has been more than 355 species, including mammals, reptiles, and birds. cryopreservation can be performed as oocyte cryopreservation before fertilization, or as embryo cryopreservation after fertilization. cryogenically preserved specimens can potentially be used to revive breeds that are endangered or extinct, for breed improvement, crossbreeding, research and development. this method can be used for virtually indefinite storage of material without deterioration over a much greater time - period relative to all other methods of ex situ conservation. however, cryo - conservation can be an expensive strategy and requires long term hygienic and economic commitment for germplas
from threats such as predators, but a prolonged period of support during which the child learns whatever is needed to live successfully in human society. = = in evolutionary biology = = in evolutionary biology, parental investment is the expenditure of time and effort towards rearing offspring that benefits the offspring's evolutionary fitness at a cost to parents'ability to invest in other components of the species'fitness. parental care requires resources from one or both parents that increases the fitness of their offspring and of themselves. these resources thus cannot be invested in the parents own survival, growth or future reproduction. therefore, parental care will only evolve in a species that requires care. some animal groups produce self - sufficient young and thus no parental care is required. for species that do require care, trade - offs exist in regards to where parental investment should be directed and how much care should be provided, since resources and time are limited. for example, if the strategy of parental care involves parents choosing to give each of a relatively small number of offspring an increased chance of surviving to reproduce themselves, they may accordingly have evolved to produce a small number of zygotes at a time, possibly only one. the ideal amount of parental investment would guarantee the survival and quality of both broods. parents need to trade off investment into current and future reproductive events, since parental care increases offspring survival at the expense of the parent's ability to invest in future broods. nonetheless, there is some evidence suggesting that in mammals provinding male care actually leads to more fecund females, and thus caring for the offspring can lead to having more number of litters. predation on offspring and species habitat - type are two potential proximate causes for the evolution of parental care. generally, parental care is expected to evolve from a previous state of no care when the costs of providing care are outweighed by the benefits to a caring parent. for example, if the benefit of increased offspring survival or quality exceed the decreased chance of survival and future reproductive success of the parent, then parental care may evolve. therefore, parental care is favoured when it is required by offspring, and the benefits of care are high. types of parental care and the amount of resources invested by parents vary considerably across the animal kingdom. the evolution of male - only, female - only, biparental or alloparental care in different groups of animals may be driven by multiple factors. firstly, different groups may have diverse physiological or evolutionary constraints that may predispose one sex to care more than the other. for example
parental care is a behavioural and evolutionary strategy adopted by some animals, involving a parental investment being made to the evolutionary fitness of offspring. patterns of parental care are widespread and highly diverse across the animal kingdom. there is great variation in different animal groups in terms of how parents care for offspring, and the amount of resources invested by parents. for example, there may be considerable variation in the amount of care invested by each sex, where females may invest more in some species, males invest more in others, or investment may be shared equally. numerous hypotheses have been proposed to describe this variation and patterns in parental care that exist between the sexes, as well as among species. parental care is any behaviour that contributes to offspring survival, such as building a nest, provisioning offspring with food, or defending offspring from predators. reptiles may produce self - sufficient young needing no parental care, while some hatchling birds may be helpless at birth, relying on their parents for survival. parental care is beneficial if it increases the parent's inclusive fitness, such as by improving offspring survival, quality, or reproductive success. since parental care is costly and often affects the parent's own future survival and reproductive success, parents ensure that any investment is well - spent. parental care thus only evolves where it is adaptive. types of parental care include maternal or paternal care, biparental care and alloparental care. sexual conflict is known to occur over mating, and further familial conflicts may continue after mating when there is parental care of the eggs or young. for example, conflict may arise between male and female parents over how much care each should provide, conflict may arise between siblings over how much care each should demand, and conflicts may arise between parents and offspring over the supply and demand of care. although parental care increases the evolutionary fitness of the offspring receiving the care, it produces a cost for the parent organism as energy is expended on caring for the offspring, and mating opportunities may be lost. as this is costly, it only evolves from a when the costs are outweighed by the benefits. parental care is seen in many insects, notably the social insects such as ants, bees and wasps ; in certain fishes, such as the mouthbrooders ; widely in birds ; in amphibians ; rarely in reptiles and especially widely in mammals, which share two major adaptations for care of the young, namely gestation ( development of the embryo inside the mother's body ) and production of milk. = = types = =
Answer:
|
adopt
| 0.3 |
reproduction is when an organism passes genetic information from itself to its what?
0. feet
1. child support
2. brain
3. younglings
the " vicar of bray " hypothesis ( or fisher - muller model ) attempts to explain why sexual reproduction might have advantages over asexual reproduction. reproduction is the process by which organisms give rise to offspring. asexual reproduction involves a single parent and results in offspring that are genetically identical to each other and to the parent. in contrast to asexual reproduction, sexual reproduction involves two parents. both the parents produce gametes through meiosis, a special type of cell division that reduces the chromosome number by half. during an early stage of meiosis, before the chromosomes are separated in the two daughter cells, the chromosomes undergo genetic recombination. this allows them to exchange some of their genetic information. therefore, the gametes from a single organism are all genetically different from each other. the process in which the two gametes from the two parents unite is called fertilization. half of the genetic information from both parents is combined. this results in offspring that are genetically different from each other and from the parents. in short, sexual reproduction allows a continuous rearrangement of genes. therefore, the offspring of a population of sexually reproducing individuals will show a more varied selection of phenotypes. due to faster attainment of favorable genetic combinations, sexually reproducing populations evolve more rapidly in response to environmental changes. under the vicar of bray hypothesis, sex benefits a population as a whole, but not individuals within it, making it a case of group selection. = = origin of the name'vicar of bray'= = the hypothesis is called after the vicar of bray, a semi - fictionalized cleric who retained his ecclesiastic office by quickly adapting to the prevailing religious winds in england, switching between various protestant and catholic rites as the ruling hierarchy changed. the figure described was simon aleyn between 1540 and 1588. the main work of thomas fuller ( d. 1661 ), worthies of england, describes this man : the vivacious vicar [ of bray ] living under king henry viii, king edward vi, queen mary, and queen elizabeth, was first a papist, then a protestant, then a papist, then a protestant again. he had seen some martyrs burnt ( two miles off ) at windsor and found this fire too hot for his tender temper. this vicar, being taxed [ attacked ] by one for being a turncoat and an inconstant changeling, said, " not so, for i always kept my principle, which is this β to live and die
development of the human body is the process of growth to maturity. the process begins with fertilization, where an egg released from the ovary of a female is penetrated by a sperm cell from a male. the resulting zygote develops through mitosis and cell differentiation, and the resulting embryo then implants in the uterus, where the embryo continues development through a fetal stage until birth. further growth and development continues after birth, and includes both physical and psychological development that is influenced by genetic, hormonal, environmental and other factors. this continues throughout life : through childhood and adolescence into adulthood. = = before birth = = development before birth, or prenatal development ( from latin natalis'relating to birth') is the process in which a zygote, and later an embryo, and then a fetus develops during gestation. prenatal development starts with fertilization and the formation of the zygote, the first stage in embryonic development which continues in fetal development until birth. = = = fertilization = = = fertilization occurs when the sperm successfully enters the ovum's membrane. the chromosomes of the sperm are passed into the egg to form a unique genome. the egg becomes a zygote and the germinal stage of embryonic development begins. the germinal stage refers to the time from fertilization, through the development of the early embryo, up until implantation. the germinal stage is over at about 10 days of gestation. the zygote contains a full complement of genetic material with all the biological characteristics of a single human being, and develops into the embryo. embryonic development has four stages : the morula stage, the blastula stage, the gastrula stage, and the neurula stage. prior to implantation, the embryo remains in a protein shell, the zona pellucida, and undergoes a series of rapid mitotic cell divisions called cleavage. a week after fertilization the embryo still has not grown in size, but hatches from the zona pellucida and adheres to the lining of the mother's uterus. this induces a decidual reaction, wherein the uterine cells proliferate and surround the embryo thus causing it to become embedded within the uterine tissue. the embryo, meanwhile, proliferates and develops both into embryonic and extra - embryonic tissue, the latter forming the fetal membranes and the placenta. in
external ectoderm and an internal endoderm. in most cases, a third germ layer, the mesoderm, also develops between them. these germ layers then differentiate to form tissues and organs. repeated instances of mating with a close relative during sexual reproduction generally leads to inbreeding depression within a population due to the increased prevalence of harmful recessive traits. animals have evolved numerous mechanisms for avoiding close inbreeding. some animals are capable of asexual reproduction, which often results in a genetic clone of the parent. this may take place through fragmentation ; budding, such as in hydra and other cnidarians ; or parthenogenesis, where fertile eggs are produced without mating, such as in aphids. = = ecology = = animals are categorised into ecological groups depending on their trophic levels and how they consume organic material. such groupings include carnivores ( further divided into subcategories such as piscivores, insectivores, ovivores, etc. ), herbivores ( subcategorised into folivores, graminivores, frugivores, granivores, nectarivores, algivores, etc. ), omnivores, fungivores, scavengers / detritivores, and parasites. interactions between animals of each biome form complex food webs within that ecosystem. in carnivorous or omnivorous species, predation is a consumer β resource interaction where the predator feeds on another organism, its prey, who often evolves anti - predator adaptations to avoid being fed upon. selective pressures imposed on one another lead to an evolutionary arms race between predator and prey, resulting in various antagonistic / competitive coevolutions. almost all multicellular predators are animals. some consumers use multiple methods ; for example, in parasitoid wasps, the larvae feed on the hosts'living tissues, killing them in the process, but the adults primarily consume nectar from flowers. other animals may have very specific feeding behaviours, such as hawksbill sea turtles which mainly eat sponges. most animals rely on biomass and bioenergy produced by plants and phytoplanktons ( collectively called producers ) through photosynthesis. herbivores, as primary consumers, eat the plant material directly to digest and absorb the nutrients, while carnivores and other animals on higher trophic levels indirectly acquire the nutrients by eating the herbivores or other animals that have
of their parents because the cells of the offspring contain copies of the genes in their parents'cells. in asexually reproducing organisms, the offspring will be a genetic copy or clone of the parent organism. in sexually reproducing organisms, a specialized form of cell division called meiosis produces cells called gametes or germ cells that are haploid, or contain only one copy of each gene. : 20. 2 the gametes produced by females are called eggs or ova, and those produced by males are called sperm. two gametes fuse to form a diploid fertilized egg, a single cell that has two sets of genes, with one copy of each gene from the mother and one from the father. : 20 during the process of meiotic cell division, an event called genetic recombination or crossing - over can sometimes occur, in which a length of dna on one chromatid is swapped with a length of dna on the corresponding homologous non - sister chromatid. this can result in reassortment of otherwise linked alleles. : 5. 5 the mendelian principle of independent assortment asserts that each of a parent's two genes for each trait will sort independently into gametes ; which allele an organism inherits for one trait is unrelated to which allele it inherits for another trait. this is in fact only true for genes that do not reside on the same chromosome or are located very far from one another on the same chromosome. the closer two genes lie on the same chromosome, the more closely they will be associated in gametes and the more often they will appear together ( known as genetic linkage ). genes that are very close are essentially never separated because it is extremely unlikely that a crossover point will occur between them. = = genome = = the genome is the total genetic material of an organism and includes both the genes and non - coding sequences. eukaryotic genes can be annotated using finder. = = = number of genes = = = the genome size, and the number of genes it encodes varies widely between organisms. the smallest genomes occur in viruses, and viroids ( which act as a single non - coding rna gene ). conversely, plants can have extremely large genomes, with rice containing > 46, 000 protein - coding genes. the total number of protein - coding genes ( the earth's proteome ) is estimated to be 5 million sequences. although the number of base - pairs of
, charles ; lenski, richard e ( 2005 - 11 - 08 ). " sexual reproduction reshapes the genetic architecture of digital organisms ". proceedings of the royal society b : biological sciences. 273 ( 1585 ). the royal society : 457 β 464. doi : 10. 1098 / rspb. 2005. 3338. issn 0962 - 8452. pmc 1560214. pmid 16615213.
Answer:
|
younglings
| null |
reproduction is when an organism passes genetic information from itself to its what?
0. feet
1. child support
2. brain
3. younglings
the " vicar of bray " hypothesis ( or fisher - muller model ) attempts to explain why sexual reproduction might have advantages over asexual reproduction. reproduction is the process by which organisms give rise to offspring. asexual reproduction involves a single parent and results in offspring that are genetically identical to each other and to the parent. in contrast to asexual reproduction, sexual reproduction involves two parents. both the parents produce gametes through meiosis, a special type of cell division that reduces the chromosome number by half. during an early stage of meiosis, before the chromosomes are separated in the two daughter cells, the chromosomes undergo genetic recombination. this allows them to exchange some of their genetic information. therefore, the gametes from a single organism are all genetically different from each other. the process in which the two gametes from the two parents unite is called fertilization. half of the genetic information from both parents is combined. this results in offspring that are genetically different from each other and from the parents. in short, sexual reproduction allows a continuous rearrangement of genes. therefore, the offspring of a population of sexually reproducing individuals will show a more varied selection of phenotypes. due to faster attainment of favorable genetic combinations, sexually reproducing populations evolve more rapidly in response to environmental changes. under the vicar of bray hypothesis, sex benefits a population as a whole, but not individuals within it, making it a case of group selection. = = origin of the name'vicar of bray'= = the hypothesis is called after the vicar of bray, a semi - fictionalized cleric who retained his ecclesiastic office by quickly adapting to the prevailing religious winds in england, switching between various protestant and catholic rites as the ruling hierarchy changed. the figure described was simon aleyn between 1540 and 1588. the main work of thomas fuller ( d. 1661 ), worthies of england, describes this man : the vivacious vicar [ of bray ] living under king henry viii, king edward vi, queen mary, and queen elizabeth, was first a papist, then a protestant, then a papist, then a protestant again. he had seen some martyrs burnt ( two miles off ) at windsor and found this fire too hot for his tender temper. this vicar, being taxed [ attacked ] by one for being a turncoat and an inconstant changeling, said, " not so, for i always kept my principle, which is this β to live and die
development of the human body is the process of growth to maturity. the process begins with fertilization, where an egg released from the ovary of a female is penetrated by a sperm cell from a male. the resulting zygote develops through mitosis and cell differentiation, and the resulting embryo then implants in the uterus, where the embryo continues development through a fetal stage until birth. further growth and development continues after birth, and includes both physical and psychological development that is influenced by genetic, hormonal, environmental and other factors. this continues throughout life : through childhood and adolescence into adulthood. = = before birth = = development before birth, or prenatal development ( from latin natalis'relating to birth') is the process in which a zygote, and later an embryo, and then a fetus develops during gestation. prenatal development starts with fertilization and the formation of the zygote, the first stage in embryonic development which continues in fetal development until birth. = = = fertilization = = = fertilization occurs when the sperm successfully enters the ovum's membrane. the chromosomes of the sperm are passed into the egg to form a unique genome. the egg becomes a zygote and the germinal stage of embryonic development begins. the germinal stage refers to the time from fertilization, through the development of the early embryo, up until implantation. the germinal stage is over at about 10 days of gestation. the zygote contains a full complement of genetic material with all the biological characteristics of a single human being, and develops into the embryo. embryonic development has four stages : the morula stage, the blastula stage, the gastrula stage, and the neurula stage. prior to implantation, the embryo remains in a protein shell, the zona pellucida, and undergoes a series of rapid mitotic cell divisions called cleavage. a week after fertilization the embryo still has not grown in size, but hatches from the zona pellucida and adheres to the lining of the mother's uterus. this induces a decidual reaction, wherein the uterine cells proliferate and surround the embryo thus causing it to become embedded within the uterine tissue. the embryo, meanwhile, proliferates and develops both into embryonic and extra - embryonic tissue, the latter forming the fetal membranes and the placenta. in
external ectoderm and an internal endoderm. in most cases, a third germ layer, the mesoderm, also develops between them. these germ layers then differentiate to form tissues and organs. repeated instances of mating with a close relative during sexual reproduction generally leads to inbreeding depression within a population due to the increased prevalence of harmful recessive traits. animals have evolved numerous mechanisms for avoiding close inbreeding. some animals are capable of asexual reproduction, which often results in a genetic clone of the parent. this may take place through fragmentation ; budding, such as in hydra and other cnidarians ; or parthenogenesis, where fertile eggs are produced without mating, such as in aphids. = = ecology = = animals are categorised into ecological groups depending on their trophic levels and how they consume organic material. such groupings include carnivores ( further divided into subcategories such as piscivores, insectivores, ovivores, etc. ), herbivores ( subcategorised into folivores, graminivores, frugivores, granivores, nectarivores, algivores, etc. ), omnivores, fungivores, scavengers / detritivores, and parasites. interactions between animals of each biome form complex food webs within that ecosystem. in carnivorous or omnivorous species, predation is a consumer β resource interaction where the predator feeds on another organism, its prey, who often evolves anti - predator adaptations to avoid being fed upon. selective pressures imposed on one another lead to an evolutionary arms race between predator and prey, resulting in various antagonistic / competitive coevolutions. almost all multicellular predators are animals. some consumers use multiple methods ; for example, in parasitoid wasps, the larvae feed on the hosts'living tissues, killing them in the process, but the adults primarily consume nectar from flowers. other animals may have very specific feeding behaviours, such as hawksbill sea turtles which mainly eat sponges. most animals rely on biomass and bioenergy produced by plants and phytoplanktons ( collectively called producers ) through photosynthesis. herbivores, as primary consumers, eat the plant material directly to digest and absorb the nutrients, while carnivores and other animals on higher trophic levels indirectly acquire the nutrients by eating the herbivores or other animals that have
of their parents because the cells of the offspring contain copies of the genes in their parents'cells. in asexually reproducing organisms, the offspring will be a genetic copy or clone of the parent organism. in sexually reproducing organisms, a specialized form of cell division called meiosis produces cells called gametes or germ cells that are haploid, or contain only one copy of each gene. : 20. 2 the gametes produced by females are called eggs or ova, and those produced by males are called sperm. two gametes fuse to form a diploid fertilized egg, a single cell that has two sets of genes, with one copy of each gene from the mother and one from the father. : 20 during the process of meiotic cell division, an event called genetic recombination or crossing - over can sometimes occur, in which a length of dna on one chromatid is swapped with a length of dna on the corresponding homologous non - sister chromatid. this can result in reassortment of otherwise linked alleles. : 5. 5 the mendelian principle of independent assortment asserts that each of a parent's two genes for each trait will sort independently into gametes ; which allele an organism inherits for one trait is unrelated to which allele it inherits for another trait. this is in fact only true for genes that do not reside on the same chromosome or are located very far from one another on the same chromosome. the closer two genes lie on the same chromosome, the more closely they will be associated in gametes and the more often they will appear together ( known as genetic linkage ). genes that are very close are essentially never separated because it is extremely unlikely that a crossover point will occur between them. = = genome = = the genome is the total genetic material of an organism and includes both the genes and non - coding sequences. eukaryotic genes can be annotated using finder. = = = number of genes = = = the genome size, and the number of genes it encodes varies widely between organisms. the smallest genomes occur in viruses, and viroids ( which act as a single non - coding rna gene ). conversely, plants can have extremely large genomes, with rice containing > 46, 000 protein - coding genes. the total number of protein - coding genes ( the earth's proteome ) is estimated to be 5 million sequences. although the number of base - pairs of
, charles ; lenski, richard e ( 2005 - 11 - 08 ). " sexual reproduction reshapes the genetic architecture of digital organisms ". proceedings of the royal society b : biological sciences. 273 ( 1585 ). the royal society : 457 β 464. doi : 10. 1098 / rspb. 2005. 3338. issn 0962 - 8452. pmc 1560214. pmid 16615213.
Answer:
|
child support
| 0.3 |
A company which causes long lasting products will likely?
0. Sell less
1. Produce more
2. Produce Less
3. Sell more
and in cases where one manufacturer is able to gain market share at the expense of others. to give another example, in advanced western households ( and depending on the economy ), the number of automobiles per family is greater than 1. to the extent that further market growth ( i. e. growth of the demand for automobiles ) is constrained ( the main buyers already own the product ), the market is said to be basically saturated. future sales depend on several factors including the rate of obsolescence ( at what age cars are replaced ), population growth, societal changes such as the spread of multi - car families, and the creation of new niche markets such as sports cars or camper vans. = = see also = = flooding the market underconsumption keynesian economics oligopoly planned obsolescence = = references = =
run, jump, touch " can be used to describe the competitive pressures of the industry. competitive enterprises continue to catch up, ready to catch up with the leaders, and those leading companies continue to run forward in order to stay ahead, and finding methods to jump over the barriers. therefore, the market becomes saturated, with only price competition. this is the fate of global competition, only the fittest companies survive. = = = pressure of product life period = = = high - tech products rapidly produce a smaller percentage of revenue unless they are improved and developed continually. this puts a premium on innovation for companies which wish to remain profitable. lack of upgrading can therefore lead to a loss - making position. = = = pressure of value - added = = = the value - added of an enterprise can be said to represent the potential for profit. mature technology, low cost requirement for entry, and universalization of technology make it easy found a so - called " low - profit " enterprise, also known as low - value - added industries. normal manufacturing and assembly enterprises are low - value - added industries, and in order to survive, can only keep expanding production capacity to maintain profits. but as long as the market is shrinking and / or product prices are decreasing, sales income will no longer be growing.. = = = trend of industries development = = = in order to overcome the pressure of low added value, enterprise's only recourse is to move towards high - value added industry trends. mastering the key technology and key components is high added value ; general manufacturing or oem is low added value ; product integration service also produce high added value. = = applications inspiration = = smile curve theory seeks to show that the success of products is inextricably related to concept, research, brand spreading and marketing. those factors require the company to hire and retain highly skilled, intelligent, professionals. typically, those professionals will be highly paid, so that countries with high smile curve slope companies will generate a higher gdp, therefore generating growing gaps between countries. = = = comparing developing and development countries = = = the united states and other developed countries have maintained highly slope of the smile curve ; however developing countries such as india and china have previously been confined to low - level employing and manufacturing. therefore, if developing countries want to achieve the high slopes of the smile curve, they need more professional analysts, researchers and brand developers to reach higher levels of economic growth. in other words, if developing countries want to compete with developed countries equally, they must use a highly
segment market cannibalism market segmentation index positioning ( marketing ) packaging and labeling food labelling regulations labelling country of origin reusable packaging seasonal packaging wine label premium product segment product lifecycle product life - cycle theory product lining product line extension product category volume product churning product differentiation product life cycle management ( article ) product life - cycle management ( marketing ) ( article ) technology lifecycle life cycle cost analysis planned obsolescence product line product proliferation whole product product portfolio b. c. g. analysis g. e. multi factoral analysis contribution margin analysis product bundling utility = = = new product development ( npd ) = = = innovation and new product development are an important part of a firm's long term growth strategy. the steps in a basic new production development process are : idea generation ( or ideation ( creative process ) ) βconcept screeningβ concept testing β business analysis β product development β market testing β commercialization and may include a soft launch the npd process can be applied to : products : new product development ; design services : service innovation ; service design environmental goods or services : eco - innovation ; ecodesign ; lean product development a recent trend in npd is the use of participatory design, also known as co - design or co - operative design, which involves stakeholders such as employees or consumers in the design process. sources of new product ideas include : research and development ; consumers or users ; distributors, suppliers or crowdsourcing. types of innovation blue ocean strategy disruptive innovation npd represents a high risk activity. it requires substantial investment and a list of product failures suggests that the probability of failure is relatively high. new product adoption and diffusion in order to develop a superior understanding of how new products are adopted by the market place and the factors that influence adoption rates, marketers often turn to a number of models or theories of the adoption / diffusion process : bass diffusion model diffusion ( article ) diffusion of innovations ( article ) early adopter hype cycle technology acceptance model ( article ) technology adoption life cycle ( article ) technology life cycle quality function deployment crossing the chasm ( book title ) = = = legal protection of new products and brands = = = new product development, including the design of product features, manufacturing processes, packaging design etc. involves creative work and therefore constitutes intellectual property. a number of different legal avenues are available to protect different types of intellectual property. certification mark copyright list of copyright acts logo patent service mark service mark symbol trademark sound trademark trade secret = = = brand management = =
or seed requires no pesticides or herbicides. another example is upcycling clothes or textiles, in which businesses can upcycle products to maintain or increase their quality. sustainable business leaders also take into account the life cycle costs for the items they produce. input costs must be considered regarding regulations, energy use, storage, and disposal. designing for the environment ( dfe ) is also an element of sustainable business. this process enables users to consider the potential environmental impacts of a product and the process used to make that product. the many possibilities for adopting green practices have led to considerable pressure being put upon companies from consumers, employees, government regulators, and other stakeholders. some companies have resorted to " greenwashing " instead of making meaningful changes, merely marketing their products in ways that suggest green practices. for example, various producers in the bamboo fiber industry have been taken to court for advertising their products as " greener " than they are. in their book corporate sustainability in international comparison, schaltegger et al. ( 2014 ) analyze the current state of corporate sustainability management and corporate social responsibility across eleven countries. their research is based on an extensive survey focusing on the companies β intention to pursue sustainability management ( i. e. motivation ; issues ), the integration of sustainability in the organization ( i. e. connecting sustainability to the core business ; involving corporate functions ; using drivers of business cases for sustainability ) and the actual implementation of sustainability management measures ( i. e. stakeholder management ; sustainability management tools and standards ; measurements ). an effective way for businesses to contribute towards waste reduction is to remanufacture products so that the materials used can have a longer lifespan. = = = examples of sustainable companies = = = the harvard business school business historian geoffrey jones traces the historical origins of green business back to pioneering start - ups in organic food and wind and solar energy before world war 1. among large corporations, ford motor company occupies an odd role in the story of sustainability. ironically, founder henry ford was a pioneer in the sustainable business realm, experimenting with plant - based fuels during the days of the model t. ford motor company also shipped the model a truck in crates that then became the vehicle floorboards at the factory destination. this was a form of upcycling, retaining high quality in a closed - loop industrial cycle. furthermore, the original auto body was made of a stronger - than - steel hemp composite. today, of course, fords aren't made of hemp, nor do they run on the
= = production orientation = = = = a production orientation is often proposed as the first of the orientations that dominated business thought. keith dated the production era from the 1860s to the 1930s, but other theorists argue that evidence of the production orientation can still be found in some companies or industries. specifically kotler and armstrong note that the production philosophy is " one of the oldest philosophies that guides sellers " and " is still useful in some situations ". the production orientation is characterised by : focus on production, manufacturing, and efficiency attainment of economies of scale, economies of scope, experience effects or all three assumption that demand exceeds supply mindset that is encapsulated by say's law ; " supply creates its own demand " or " if somebody makes a product, somebody else will want to buy it " limited research that is largely limited to technical - product research rather than customer research rose to prominence in an environment which had a shortage of manufactured goods relative to demand, so goods sold easily. minimal promotion and advertising, marketing communications limited to raising awareness of the product's existence = = = = selling orientation = = = = the selling orientation is thought to have begun during the great depression and continued well into the 1950s although examples of this orientation can still be found today. kotler et al. note that the selling concept " is typically practised with unsought goods ". the selling orientation is characterised by : aggressive selling to push products, often involving door - to - door selling accepting every possible sale or booking, regardless of its suitability for the business strong transactional focus ( ignores potential relationships ) = = = = marketing orientation = = = = the marketing orientation or the marketing concept emerged in the 1950s. characteristics of the marketing orientation : thorough understanding of the customer's needs, wants and behaviors should be the focal point of all marketing decisions marketing efforts ( sales, advertising, product management, pricing ) should be integrated and in tune with the customer new product concepts should flow from extensive market analysis and product testing = = = = societal marketing concept = = = = phillip kotler is credited with first proposing the societal marketing orientation or concept in an article published in the harvard business review in 1972. however, some marketing historians, notably wilkie and moore, have argued that a societal perspective was evident in marketing theory and in marketing texts, since the discipline's inception in the early 1900s or that societal marketing is merely an extension of the marketing concept. the societal marketing concept adopts the position that marketers have a greater social responsibility than simply
Answer:
|
Sell less
| null |
A company which causes long lasting products will likely?
0. Sell less
1. Produce more
2. Produce Less
3. Sell more
and in cases where one manufacturer is able to gain market share at the expense of others. to give another example, in advanced western households ( and depending on the economy ), the number of automobiles per family is greater than 1. to the extent that further market growth ( i. e. growth of the demand for automobiles ) is constrained ( the main buyers already own the product ), the market is said to be basically saturated. future sales depend on several factors including the rate of obsolescence ( at what age cars are replaced ), population growth, societal changes such as the spread of multi - car families, and the creation of new niche markets such as sports cars or camper vans. = = see also = = flooding the market underconsumption keynesian economics oligopoly planned obsolescence = = references = =
run, jump, touch " can be used to describe the competitive pressures of the industry. competitive enterprises continue to catch up, ready to catch up with the leaders, and those leading companies continue to run forward in order to stay ahead, and finding methods to jump over the barriers. therefore, the market becomes saturated, with only price competition. this is the fate of global competition, only the fittest companies survive. = = = pressure of product life period = = = high - tech products rapidly produce a smaller percentage of revenue unless they are improved and developed continually. this puts a premium on innovation for companies which wish to remain profitable. lack of upgrading can therefore lead to a loss - making position. = = = pressure of value - added = = = the value - added of an enterprise can be said to represent the potential for profit. mature technology, low cost requirement for entry, and universalization of technology make it easy found a so - called " low - profit " enterprise, also known as low - value - added industries. normal manufacturing and assembly enterprises are low - value - added industries, and in order to survive, can only keep expanding production capacity to maintain profits. but as long as the market is shrinking and / or product prices are decreasing, sales income will no longer be growing.. = = = trend of industries development = = = in order to overcome the pressure of low added value, enterprise's only recourse is to move towards high - value added industry trends. mastering the key technology and key components is high added value ; general manufacturing or oem is low added value ; product integration service also produce high added value. = = applications inspiration = = smile curve theory seeks to show that the success of products is inextricably related to concept, research, brand spreading and marketing. those factors require the company to hire and retain highly skilled, intelligent, professionals. typically, those professionals will be highly paid, so that countries with high smile curve slope companies will generate a higher gdp, therefore generating growing gaps between countries. = = = comparing developing and development countries = = = the united states and other developed countries have maintained highly slope of the smile curve ; however developing countries such as india and china have previously been confined to low - level employing and manufacturing. therefore, if developing countries want to achieve the high slopes of the smile curve, they need more professional analysts, researchers and brand developers to reach higher levels of economic growth. in other words, if developing countries want to compete with developed countries equally, they must use a highly
segment market cannibalism market segmentation index positioning ( marketing ) packaging and labeling food labelling regulations labelling country of origin reusable packaging seasonal packaging wine label premium product segment product lifecycle product life - cycle theory product lining product line extension product category volume product churning product differentiation product life cycle management ( article ) product life - cycle management ( marketing ) ( article ) technology lifecycle life cycle cost analysis planned obsolescence product line product proliferation whole product product portfolio b. c. g. analysis g. e. multi factoral analysis contribution margin analysis product bundling utility = = = new product development ( npd ) = = = innovation and new product development are an important part of a firm's long term growth strategy. the steps in a basic new production development process are : idea generation ( or ideation ( creative process ) ) βconcept screeningβ concept testing β business analysis β product development β market testing β commercialization and may include a soft launch the npd process can be applied to : products : new product development ; design services : service innovation ; service design environmental goods or services : eco - innovation ; ecodesign ; lean product development a recent trend in npd is the use of participatory design, also known as co - design or co - operative design, which involves stakeholders such as employees or consumers in the design process. sources of new product ideas include : research and development ; consumers or users ; distributors, suppliers or crowdsourcing. types of innovation blue ocean strategy disruptive innovation npd represents a high risk activity. it requires substantial investment and a list of product failures suggests that the probability of failure is relatively high. new product adoption and diffusion in order to develop a superior understanding of how new products are adopted by the market place and the factors that influence adoption rates, marketers often turn to a number of models or theories of the adoption / diffusion process : bass diffusion model diffusion ( article ) diffusion of innovations ( article ) early adopter hype cycle technology acceptance model ( article ) technology adoption life cycle ( article ) technology life cycle quality function deployment crossing the chasm ( book title ) = = = legal protection of new products and brands = = = new product development, including the design of product features, manufacturing processes, packaging design etc. involves creative work and therefore constitutes intellectual property. a number of different legal avenues are available to protect different types of intellectual property. certification mark copyright list of copyright acts logo patent service mark service mark symbol trademark sound trademark trade secret = = = brand management = =
or seed requires no pesticides or herbicides. another example is upcycling clothes or textiles, in which businesses can upcycle products to maintain or increase their quality. sustainable business leaders also take into account the life cycle costs for the items they produce. input costs must be considered regarding regulations, energy use, storage, and disposal. designing for the environment ( dfe ) is also an element of sustainable business. this process enables users to consider the potential environmental impacts of a product and the process used to make that product. the many possibilities for adopting green practices have led to considerable pressure being put upon companies from consumers, employees, government regulators, and other stakeholders. some companies have resorted to " greenwashing " instead of making meaningful changes, merely marketing their products in ways that suggest green practices. for example, various producers in the bamboo fiber industry have been taken to court for advertising their products as " greener " than they are. in their book corporate sustainability in international comparison, schaltegger et al. ( 2014 ) analyze the current state of corporate sustainability management and corporate social responsibility across eleven countries. their research is based on an extensive survey focusing on the companies β intention to pursue sustainability management ( i. e. motivation ; issues ), the integration of sustainability in the organization ( i. e. connecting sustainability to the core business ; involving corporate functions ; using drivers of business cases for sustainability ) and the actual implementation of sustainability management measures ( i. e. stakeholder management ; sustainability management tools and standards ; measurements ). an effective way for businesses to contribute towards waste reduction is to remanufacture products so that the materials used can have a longer lifespan. = = = examples of sustainable companies = = = the harvard business school business historian geoffrey jones traces the historical origins of green business back to pioneering start - ups in organic food and wind and solar energy before world war 1. among large corporations, ford motor company occupies an odd role in the story of sustainability. ironically, founder henry ford was a pioneer in the sustainable business realm, experimenting with plant - based fuels during the days of the model t. ford motor company also shipped the model a truck in crates that then became the vehicle floorboards at the factory destination. this was a form of upcycling, retaining high quality in a closed - loop industrial cycle. furthermore, the original auto body was made of a stronger - than - steel hemp composite. today, of course, fords aren't made of hemp, nor do they run on the
= = production orientation = = = = a production orientation is often proposed as the first of the orientations that dominated business thought. keith dated the production era from the 1860s to the 1930s, but other theorists argue that evidence of the production orientation can still be found in some companies or industries. specifically kotler and armstrong note that the production philosophy is " one of the oldest philosophies that guides sellers " and " is still useful in some situations ". the production orientation is characterised by : focus on production, manufacturing, and efficiency attainment of economies of scale, economies of scope, experience effects or all three assumption that demand exceeds supply mindset that is encapsulated by say's law ; " supply creates its own demand " or " if somebody makes a product, somebody else will want to buy it " limited research that is largely limited to technical - product research rather than customer research rose to prominence in an environment which had a shortage of manufactured goods relative to demand, so goods sold easily. minimal promotion and advertising, marketing communications limited to raising awareness of the product's existence = = = = selling orientation = = = = the selling orientation is thought to have begun during the great depression and continued well into the 1950s although examples of this orientation can still be found today. kotler et al. note that the selling concept " is typically practised with unsought goods ". the selling orientation is characterised by : aggressive selling to push products, often involving door - to - door selling accepting every possible sale or booking, regardless of its suitability for the business strong transactional focus ( ignores potential relationships ) = = = = marketing orientation = = = = the marketing orientation or the marketing concept emerged in the 1950s. characteristics of the marketing orientation : thorough understanding of the customer's needs, wants and behaviors should be the focal point of all marketing decisions marketing efforts ( sales, advertising, product management, pricing ) should be integrated and in tune with the customer new product concepts should flow from extensive market analysis and product testing = = = = societal marketing concept = = = = phillip kotler is credited with first proposing the societal marketing orientation or concept in an article published in the harvard business review in 1972. however, some marketing historians, notably wilkie and moore, have argued that a societal perspective was evident in marketing theory and in marketing texts, since the discipline's inception in the early 1900s or that societal marketing is merely an extension of the marketing concept. the societal marketing concept adopts the position that marketers have a greater social responsibility than simply
Answer:
|
Sell more
| 0.3 |
What requires soil to grow?
0. lakes
1. car engine
2. daffodils
3. cows
= = = a pilot project in europe used a plow to slightly loosen and ridge the soil. they planted oats and vetch, which attracts nitrogen - fixing bacteria. they planted small olive trees to boost microbial diversity. they split an unirrigated 100 - hectare field into three zones, one treated with chemical fertilizer and pesticides ; and the other two with different amounts of an organic biofertilizer, consisting of fermented grape leftovers and a variety of bacteria and fungi, along with four types of mycorrhiza spores. the crops that had received the most organic fertilizer had reached nearly twice the height of those in zone a and were inches taller than zone c. the yield of that section equaled that of irrigated crops, whereas the yield of the conventional technique was negligible. the mycorrhiza had penetrated the rock by excreting acids, allowing plant roots to reach almost 2 meters into the rocky soil and reach groundwater. = = soil microbiologists = = nikolai aleksandrovich krasil'nikov ( 1896 β 1973 ), russian michael goodfellow ( born 1941 ), british = = see also = = natural farming korean natural farming effective microorganisms soil biology soil biomantle soil life = = references = =
produced may be greater than 4. 5 kg per worm per year. by burrowing, the earthworm improves soil porosity, creating channels that enhance the processes of aeration and drainage. other important soil organisms include nematodes, mycorrhiza and bacteria. a quarter of all the animal species live underground. according to the 2020 food and agriculture organization β s report " state of knowledge of soil biodiversity β status, challenges and potentialities ", there are major gaps in knowledge about biodiversity in soils. degraded soil requires synthetic fertilizer to produce high yields. lacking structure increases erosion and carries nitrogen and other pollutants into rivers and streams. each one percent increase in soil organic matter helps soil hold 20, 000 gallons more water per acre. = = = mineralization = = = to allow plants to fully realize their phytonutrient potential, active mineralization of the soil is sometimes undertaken. this can involve adding crushed rock or chemical soil supplements. in either case, the purpose is to combat mineral depletion. a broad range of minerals can be used, including common substances such as phosphorus and more exotic substances such as zinc and selenium. extensive research examines the phase transitions of minerals in soil with aqueous contact. flooding can bring significant sediments to an alluvial plain. while this effect may not be desirable if floods endanger life or if the sediment originates from productive land, this process of addition to a floodplain is a natural process that can rejuvenate soil chemistry through mineralization. = = see also = = = = references = = = = further reading = = moorberg, colby j., ed. ( 2019 ). soil and water conservation : an annotated bibliography. npp ebooks. isbn 978 - 1 - 944548 - 26 - 1. online book ( the most current version of the text ) download book β kindle, nook, apple, kobo, and pdf
soils that lack plants, animals or organic matter. ecosystems that experience such disturbances undergo primary succession. a less severe disturbance like forest fires, hurricanes or cultivation result in secondary succession and a faster recovery. : 348 more severe and more frequent disturbance result in longer recovery times. from one year to another, ecosystems experience variation in their biotic and abiotic environments. a drought, a colder than usual winter, and a pest outbreak all are short - term variability in environmental conditions. animal populations vary from year to year, building up during resource - rich periods and crashing as they overshoot their food supply. longer - term changes also shape ecosystem processes. for example, the forests of eastern north america still show legacies of cultivation which ceased in 1850 when large areas were reverted to forests. : 340 another example is the methane production in eastern siberian lakes that is controlled by organic matter which accumulated during the pleistocene. = = = nutrient cycling = = = ecosystems continually exchange energy and carbon with the wider environment. mineral nutrients, on the other hand, are mostly cycled back and forth between plants, animals, microbes and the soil. most nitrogen enters ecosystems through biological nitrogen fixation, is deposited through precipitation, dust, gases or is applied as fertilizer. : 266 most terrestrial ecosystems are nitrogen - limited in the short term making nitrogen cycling an important control on ecosystem production. : 289 over the long term, phosphorus availability can also be critical. macronutrients which are required by all plants in large quantities include the primary nutrients ( which are most limiting as they are used in largest amounts ) : nitrogen, phosphorus, potassium. : 231 secondary major nutrients ( less often limiting ) include : calcium, magnesium, sulfur. micronutrients required by all plants in small quantities include boron, chloride, copper, iron, manganese, molybdenum, zinc. finally, there are also beneficial nutrients which may be required by certain plants or by plants under specific environmental conditions : aluminum, cobalt, iodine, nickel, selenium, silicon, sodium, vanadium. : 231 until modern times, nitrogen fixation was the major source of nitrogen for ecosystems. nitrogen - fixing bacteria either live symbiotically with plants or live freely in the soil. the energetic cost is high for plants that support nitrogen - fixing symbionts β as much as 25 % of gross primary production when measured in controlled conditions. many members of the legume plant family support nitrogen - fixing symbionts. some cyanobacteria are
soils that lack plants, animals or organic matter. ecosystems that experience such disturbances undergo primary succession. a less severe disturbance like forest fires, hurricanes or cultivation result in secondary succession and a faster recovery. : 348 more severe and more frequent disturbance result in longer recovery times. from one year to another, ecosystems experience variation in their biotic and abiotic environments. a drought, a colder than usual winter, and a pest outbreak all are short - term variability in environmental conditions. animal populations vary from year to year, building up during resource - rich periods and crashing as they overshoot their food supply. longer - term changes also shape ecosystem processes. for example, the forests of eastern north america still show legacies of cultivation which ceased in 1850 when large areas were reverted to forests. : 340 another example is the methane production in eastern siberian lakes that is controlled by organic matter which accumulated during the pleistocene. = = = nutrient cycling = = = ecosystems continually exchange energy and carbon with the wider environment. mineral nutrients, on the other hand, are mostly cycled back and forth between plants, animals, microbes and the soil. most nitrogen enters ecosystems through biological nitrogen fixation, is deposited through precipitation, dust, gases or is applied as fertilizer. : 266 most terrestrial ecosystems are nitrogen - limited in the short term making nitrogen cycling an important control on ecosystem production. : 289 over the long term, phosphorus availability can also be critical. macronutrients which are required by all plants in large quantities include the primary nutrients ( which are most limiting as they are used in largest amounts ) : nitrogen, phosphorus, potassium. : 231 secondary major nutrients ( less often limiting ) include : calcium, magnesium, sulfur. micronutrients required by all plants in small quantities include boron, chloride, copper, iron, manganese, molybdenum, zinc. finally, there are also beneficial nutrients which may be required by certain plants or by plants under specific environmental conditions : aluminum, cobalt, iodine, nickel, selenium, silicon, sodium, vanadium. : 231 until modern times, nitrogen fixation was the major source of nitrogen for ecosystems. nitrogen - fixing bacteria either live symbiotically with plants or live freely in the soil. the energetic cost is high for plants that support nitrogen - fixing symbionts β as much as 25 % of gross primary production when measured in controlled conditions. many members of the legume plant family support nitrogen - fixing symbionts. some cyanobacteria are
flux of contaminants to the water column by burying hydrophobic organic contaminants into the sediment. burial of uncontaminated particles by bioturbating organisms provides more absorptive surfaces to sequester chemical pollutants in the sediments. = = ecosystem impacts = = nutrient cycling is still affected by bioturbation in the modern earth. some examples in the terrestrial and aquatic ecosystems are below. = = = terrestrial = = = plants and animals utilize soil for food and shelter, disturbing the upper soil layers and transporting chemically weathered rock called saprolite from the lower soil depths to the surface. terrestrial bioturbation is important in soil production, burial, organic matter content, and downslope transport. tree roots are sources of soil organic matter, with root growth and stump decay also contributing to soil transport and mixing. death and decay of tree roots first delivers organic matter to the soil and then creates voids, decreasing soil density. tree uprooting causes considerable soil displacement by producing mounds, mixing the soil, or inverting vertical sections of soil. burrowing animals, such as earth worms and small mammals, form passageways for air and water transport which changes the soil properties, such as the vertical particle - size distribution, soil porosity, and nutrient content. invertebrates that burrow and consume plant detritus help produce an organic - rich topsoil known as the soil biomantle, and thus contribute to the formation of soil horizons. small mammals such as pocket gophers also play an important role in the production of soil, possibly with an equal magnitude to abiotic processes. pocket gophers form above - ground mounds, which moves soil from the lower soil horizons to the surface, exposing minimally weathered rock to surface erosion processes, speeding soil formation. pocket gophers are thought to play an important role in the downslope transport of soil, as the soil that forms their mounds is more susceptible to erosion and subsequent transport. similar to tree root effects, the construction of burrows - even when backfilled - decreases soil density. the formation of surface mounds also buries surface vegetation, creating nutrient hotspots when the vegetation decomposes, increasing soil organic matter. due to the high metabolic demands of their burrow - excavating subterranean lifestyle, pocket gophers must consume large amounts of plant material. though this has a detrimental effect on individual plants, the net effect of pocket gophers is increased plant growth from their positive effects on soil nutrient content and physical soil
Answer:
|
daffodils
| null |
What requires soil to grow?
0. lakes
1. car engine
2. daffodils
3. cows
= = = a pilot project in europe used a plow to slightly loosen and ridge the soil. they planted oats and vetch, which attracts nitrogen - fixing bacteria. they planted small olive trees to boost microbial diversity. they split an unirrigated 100 - hectare field into three zones, one treated with chemical fertilizer and pesticides ; and the other two with different amounts of an organic biofertilizer, consisting of fermented grape leftovers and a variety of bacteria and fungi, along with four types of mycorrhiza spores. the crops that had received the most organic fertilizer had reached nearly twice the height of those in zone a and were inches taller than zone c. the yield of that section equaled that of irrigated crops, whereas the yield of the conventional technique was negligible. the mycorrhiza had penetrated the rock by excreting acids, allowing plant roots to reach almost 2 meters into the rocky soil and reach groundwater. = = soil microbiologists = = nikolai aleksandrovich krasil'nikov ( 1896 β 1973 ), russian michael goodfellow ( born 1941 ), british = = see also = = natural farming korean natural farming effective microorganisms soil biology soil biomantle soil life = = references = =
produced may be greater than 4. 5 kg per worm per year. by burrowing, the earthworm improves soil porosity, creating channels that enhance the processes of aeration and drainage. other important soil organisms include nematodes, mycorrhiza and bacteria. a quarter of all the animal species live underground. according to the 2020 food and agriculture organization β s report " state of knowledge of soil biodiversity β status, challenges and potentialities ", there are major gaps in knowledge about biodiversity in soils. degraded soil requires synthetic fertilizer to produce high yields. lacking structure increases erosion and carries nitrogen and other pollutants into rivers and streams. each one percent increase in soil organic matter helps soil hold 20, 000 gallons more water per acre. = = = mineralization = = = to allow plants to fully realize their phytonutrient potential, active mineralization of the soil is sometimes undertaken. this can involve adding crushed rock or chemical soil supplements. in either case, the purpose is to combat mineral depletion. a broad range of minerals can be used, including common substances such as phosphorus and more exotic substances such as zinc and selenium. extensive research examines the phase transitions of minerals in soil with aqueous contact. flooding can bring significant sediments to an alluvial plain. while this effect may not be desirable if floods endanger life or if the sediment originates from productive land, this process of addition to a floodplain is a natural process that can rejuvenate soil chemistry through mineralization. = = see also = = = = references = = = = further reading = = moorberg, colby j., ed. ( 2019 ). soil and water conservation : an annotated bibliography. npp ebooks. isbn 978 - 1 - 944548 - 26 - 1. online book ( the most current version of the text ) download book β kindle, nook, apple, kobo, and pdf
soils that lack plants, animals or organic matter. ecosystems that experience such disturbances undergo primary succession. a less severe disturbance like forest fires, hurricanes or cultivation result in secondary succession and a faster recovery. : 348 more severe and more frequent disturbance result in longer recovery times. from one year to another, ecosystems experience variation in their biotic and abiotic environments. a drought, a colder than usual winter, and a pest outbreak all are short - term variability in environmental conditions. animal populations vary from year to year, building up during resource - rich periods and crashing as they overshoot their food supply. longer - term changes also shape ecosystem processes. for example, the forests of eastern north america still show legacies of cultivation which ceased in 1850 when large areas were reverted to forests. : 340 another example is the methane production in eastern siberian lakes that is controlled by organic matter which accumulated during the pleistocene. = = = nutrient cycling = = = ecosystems continually exchange energy and carbon with the wider environment. mineral nutrients, on the other hand, are mostly cycled back and forth between plants, animals, microbes and the soil. most nitrogen enters ecosystems through biological nitrogen fixation, is deposited through precipitation, dust, gases or is applied as fertilizer. : 266 most terrestrial ecosystems are nitrogen - limited in the short term making nitrogen cycling an important control on ecosystem production. : 289 over the long term, phosphorus availability can also be critical. macronutrients which are required by all plants in large quantities include the primary nutrients ( which are most limiting as they are used in largest amounts ) : nitrogen, phosphorus, potassium. : 231 secondary major nutrients ( less often limiting ) include : calcium, magnesium, sulfur. micronutrients required by all plants in small quantities include boron, chloride, copper, iron, manganese, molybdenum, zinc. finally, there are also beneficial nutrients which may be required by certain plants or by plants under specific environmental conditions : aluminum, cobalt, iodine, nickel, selenium, silicon, sodium, vanadium. : 231 until modern times, nitrogen fixation was the major source of nitrogen for ecosystems. nitrogen - fixing bacteria either live symbiotically with plants or live freely in the soil. the energetic cost is high for plants that support nitrogen - fixing symbionts β as much as 25 % of gross primary production when measured in controlled conditions. many members of the legume plant family support nitrogen - fixing symbionts. some cyanobacteria are
soils that lack plants, animals or organic matter. ecosystems that experience such disturbances undergo primary succession. a less severe disturbance like forest fires, hurricanes or cultivation result in secondary succession and a faster recovery. : 348 more severe and more frequent disturbance result in longer recovery times. from one year to another, ecosystems experience variation in their biotic and abiotic environments. a drought, a colder than usual winter, and a pest outbreak all are short - term variability in environmental conditions. animal populations vary from year to year, building up during resource - rich periods and crashing as they overshoot their food supply. longer - term changes also shape ecosystem processes. for example, the forests of eastern north america still show legacies of cultivation which ceased in 1850 when large areas were reverted to forests. : 340 another example is the methane production in eastern siberian lakes that is controlled by organic matter which accumulated during the pleistocene. = = = nutrient cycling = = = ecosystems continually exchange energy and carbon with the wider environment. mineral nutrients, on the other hand, are mostly cycled back and forth between plants, animals, microbes and the soil. most nitrogen enters ecosystems through biological nitrogen fixation, is deposited through precipitation, dust, gases or is applied as fertilizer. : 266 most terrestrial ecosystems are nitrogen - limited in the short term making nitrogen cycling an important control on ecosystem production. : 289 over the long term, phosphorus availability can also be critical. macronutrients which are required by all plants in large quantities include the primary nutrients ( which are most limiting as they are used in largest amounts ) : nitrogen, phosphorus, potassium. : 231 secondary major nutrients ( less often limiting ) include : calcium, magnesium, sulfur. micronutrients required by all plants in small quantities include boron, chloride, copper, iron, manganese, molybdenum, zinc. finally, there are also beneficial nutrients which may be required by certain plants or by plants under specific environmental conditions : aluminum, cobalt, iodine, nickel, selenium, silicon, sodium, vanadium. : 231 until modern times, nitrogen fixation was the major source of nitrogen for ecosystems. nitrogen - fixing bacteria either live symbiotically with plants or live freely in the soil. the energetic cost is high for plants that support nitrogen - fixing symbionts β as much as 25 % of gross primary production when measured in controlled conditions. many members of the legume plant family support nitrogen - fixing symbionts. some cyanobacteria are
flux of contaminants to the water column by burying hydrophobic organic contaminants into the sediment. burial of uncontaminated particles by bioturbating organisms provides more absorptive surfaces to sequester chemical pollutants in the sediments. = = ecosystem impacts = = nutrient cycling is still affected by bioturbation in the modern earth. some examples in the terrestrial and aquatic ecosystems are below. = = = terrestrial = = = plants and animals utilize soil for food and shelter, disturbing the upper soil layers and transporting chemically weathered rock called saprolite from the lower soil depths to the surface. terrestrial bioturbation is important in soil production, burial, organic matter content, and downslope transport. tree roots are sources of soil organic matter, with root growth and stump decay also contributing to soil transport and mixing. death and decay of tree roots first delivers organic matter to the soil and then creates voids, decreasing soil density. tree uprooting causes considerable soil displacement by producing mounds, mixing the soil, or inverting vertical sections of soil. burrowing animals, such as earth worms and small mammals, form passageways for air and water transport which changes the soil properties, such as the vertical particle - size distribution, soil porosity, and nutrient content. invertebrates that burrow and consume plant detritus help produce an organic - rich topsoil known as the soil biomantle, and thus contribute to the formation of soil horizons. small mammals such as pocket gophers also play an important role in the production of soil, possibly with an equal magnitude to abiotic processes. pocket gophers form above - ground mounds, which moves soil from the lower soil horizons to the surface, exposing minimally weathered rock to surface erosion processes, speeding soil formation. pocket gophers are thought to play an important role in the downslope transport of soil, as the soil that forms their mounds is more susceptible to erosion and subsequent transport. similar to tree root effects, the construction of burrows - even when backfilled - decreases soil density. the formation of surface mounds also buries surface vegetation, creating nutrient hotspots when the vegetation decomposes, increasing soil organic matter. due to the high metabolic demands of their burrow - excavating subterranean lifestyle, pocket gophers must consume large amounts of plant material. though this has a detrimental effect on individual plants, the net effect of pocket gophers is increased plant growth from their positive effects on soil nutrient content and physical soil
Answer:
|
car engine
| 0.3 |
The function of your lungs be impaired on
0. a small sailboat
1. Saturn's rings
2. a windswept beach
3. a pleasant meadow
deep ocean, where most of the water is below 4 Β°c. there are temperature anomalies at active volcanic sites and hydrothermal vents, where deep - water temperatures can significantly exceed 100 Β°c. = = = thermal conductivity = = = water conducts heat around 25 times more efficiently than air. hypothermia, a potentially fatal condition, occurs when the human body's core temperature falls below 35 Β°c. insulating the body's warmth from water is the main purpose of diving suits and exposure suits when used in water temperatures below 25 Β°c. = = = acoustic properties = = = sound is transmitted about 4. 3 times faster in water ( 1, 484 m / s in fresh water ) than in air ( 343 m / s ). the human brain can determine the direction of sound in air by detecting small differences in the time it takes for sound waves in air to reach each of the two ears. for these reasons, divers find it difficult to determine the direction of sound underwater. some animals have adapted to this difference and many use sound to navigate underwater. = = ecosystems = = an aquatic ecosystem is an ecosystem in a body of water. communities of organisms that are dependent on each other and on their environment live in aquatic ecosystems. the two main types of aquatic ecosystems are marine ecosystems and freshwater ecosystems. marine ecosystems are the largest of earth's aquatic ecosystems and are distinguished by waters that have a high salt content. marine waters cover more than 70 % of the surface of the earth and account for more than 97 % of earth's water supply and 90 % of habitable space on earth. marine ecosystems include nearshore systems, such as the salt marshes, mudflats, seagrass meadows, mangroves, rocky intertidal systems and coral reefs. they also extend from the coast to include offshore systems, such as the surface ocean, pelagic ocean waters, the deep sea, oceanic hydrothermal vents, and the sea floor. marine ecosystems are characterized by the biological community of organisms that they are associated with and their physical environment. as the world ocean is the principal component of earth's hydrosphere, it is integral to life, forms part of the carbon cycle, and influences climate and weather patterns. the world ocean is the habitat of 230, 000 known species, but because much of it is unexplored, the number of species that exist in the ocean is much larger, possibly over two million. freshwater ecosystems include lakes and ponds, rivers, streams, springs, aquifers, bogs,
and the tympanic membrane ( eardrum ) can rupture at depths under 10 ft ( 3 m ). the danger of pressure damage is greatest in shallow water because the ratio of pressure change is greatest near the surface of the water. the raised pressure also affects the solution of breathing gases in the tissues over time, and can lead to a range of adverse effects, such as inert gas narcosis, and oxygen toxicity. decompression must be controlled to avoid bubble formation in the tissues and the consequent symptoms of decompression sickness. with a few exceptions, the underwater environment tends to cool the unprotected human body. this heat loss will generally lead to hypothermia eventually. = = = hazards = = = there are several classes of hazards to humans inherent to the underwater environment. absence of breathable gas, which can cause asphyxia, specifically by drowning. ambient pressures which could cause barotrauma, or toxic effects of breathing gas components at raised partial pressures. ambient temperatures which may lead to hypothermia, or in unusual cases, to hyperthermia, due to high rates of heat exchange. solution of inert breathing gas components may lead to decompression sickness if decompression is too rapid. entrainment of diver by moving water in currents and waves can cause injury by impacting the diver against hard objects or moving them to inappropriate depths. dangerous aquatic organisms of various sorts. = = = ambient pressure diving = = = in ambient pressure diving, the diver is directly exposed to the pressure of the surrounding water. the ambient pressure diver may dive on breath - hold, or use breathing apparatus for scuba diving or surface - supplied diving, and the saturation diving technique reduces the risk of decompression sickness ( dcs ) after long - duration deep dives. immersion in water and exposure to cold water and high pressure have physiological effects on the diver which limit the depths and duration possible in ambient pressure diving. breath - hold endurance is a severe limitation, and breathing at high ambient pressure adds further complications, both directly and indirectly. technological solutions have been developed which can greatly extend depth and duration of human ambient pressure dives, and allow useful work to be done underwater. = = = atmospheric pressure diving = = = a diver can be isolated from the ambient pressure by using an atmospheric diving suit ( ads ), which is a small one - person articulated anthropomorphic submersible which resembles a suit of armour, with elaborate pressure
found microbial communities apparently based on the products of reactions between water and the constituents of rocks. these communities have not been studied much, but may be an important part of the global carbon cycle. rock in mines two miles deep also harbour microbes ; these live on minute traces of hydrogen produced in slow oxidizing reactions inside the rock. these metabolic reactions allow life to exist in places with no oxygen or light, an environment that had previously been thought to be devoid of life. the intertidal zone and the photic zone in the oceans are relatively familiar habitat types. however the vast bulk of the ocean is inhospitable to air - breathing humans, with scuba divers limited to the upper 50 m ( 160 ft ) or so. the lower limit for photosynthesis is 100 to 200 m ( 330 to 660 ft ) and below that depth the prevailing conditions include total darkness, high pressure, little oxygen ( in some places ), scarce food resources and extreme cold. this habitat is very challenging to research, and as well as being little - studied, it is vast, with 79 % of the earth's biosphere being at depths greater than 1, 000 m ( 3, 300 ft ). with no plant life, the animals in this zone are either detritivores, reliant on food drifting down from surface layers, or they are predators, feeding on each other. some organisms are pelagic, swimming or drifting in mid - ocean, while others are benthic, living on or near the seabed. their growth rates and metabolisms tend to be slow, their eyes may be very large to detect what little illumination there is, or they may be blind and rely on other sensory inputs. a number of deep sea creatures are bioluminescent ; this serves a variety of functions including predation, protection and social recognition. in general, the bodies of animals living at great depths are adapted to high pressure environments by having pressure - resistant biomolecules and small organic molecules present in their cells known as piezolytes, which give the proteins the flexibility they need. there are also unsaturated fats in their membranes which prevent them from solidifying at low temperatures. hydrothermal vents were first discovered in the ocean depths in 1977. they result from seawater becoming heated after seeping through cracks to places where hot magma is close to the seabed. the under - water hot springs may gush forth at temperatures of over 340 Β°c ( 640 Β°f ) and support unique communities of organisms in their
to maintain two kinds of pressure simultaneously to produce and modify phonation. to produce phonation at all, the lungs must maintain a pressure of 3 β 5 cm h2o higher than the pressure above the glottis. however small and fast adjustments are made to the subglottal pressure to modify speech for suprasegmental features like stress. a number of thoracic muscles are used to make these adjustments. because the lungs and thorax stretch during inhalation, the elastic forces of the lungs alone can produce pressure differentials sufficient for phonation at lung volumes above 50 percent of vital capacity. above 50 percent of vital capacity, the respiratory muscles are used to " check " the elastic forces of the thorax to maintain a stable pressure differential. below that volume, they are used to increase the subglottal pressure by actively exhaling air. during speech, the respiratory cycle is modified to accommodate both linguistic and biological needs. exhalation, usually about 60 percent of the respiratory cycle at rest, is increased to about 90 percent of the respiratory cycle. because metabolic needs are relatively stable, the total volume of air moved in most cases of speech remains about the same as quiet tidal breathing. increases in speech intensity of 18 db ( a loud conversation ) has relatively little impact on the volume of air moved. because their respiratory systems are not as developed as adults, children tend to use a larger proportion of their vital capacity compared to adults, with more deep inhales. = = = source β filter theory = = = the source β filter model of speech is a theory of speech production which explains the link between vocal tract posture and the acoustic consequences. under this model, the vocal tract can be modeled as a noise source coupled onto an acoustic filter. the noise source in many cases is the larynx during the process of voicing, though other noise sources can be modeled in the same way. the shape of the supraglottal vocal tract acts as the filter, and different configurations of the articulators result in different acoustic patterns. these changes are predictable. the vocal tract can be modeled as a sequence of tubes, closed at one end, with varying diameters, and by using equations for acoustic resonance the acoustic effect of an articulatory posture can be derived. the process of inverse filtering uses this principle to analyze the source spectrum produced by the vocal folds during voicing. by taking the inverse of a predicted filter, the acoustic effect of the supraglottal vocal tract can
technically incorrect given respiration continues and the carbon dioxide metabolically produced from the oxygen inhaled prior to inert gas asphyxiation can be exhaled without restriction, which can prevent acidosis and the strong urge to breathe caused by hypercapnia. = = process = = when humans breathe in an asphyxiant gas or any other physiologically inert gas, they exhale carbon dioxide without re - supplying oxygen. physiologically inert gases ( those that have no toxic effect, but merely dilute oxygen ) are generally free of odor and taste. accordingly, the human subject detects little abnormal sensation as the oxygen level falls. this leads to asphyxiation ( death from lack of oxygen ) without the painful and traumatic feeling of suffocation ( the hypercapnic alarm response, which in humans arises mostly from carbon dioxide levels rising ), or the side effects of poisoning. in scuba diving rebreather accidents, a slow decrease in oxygen breathing gas content can produce variable or no sensation. by contrast, suddenly breathing pure inert gas causes oxygen levels in the blood to fall precipitously, and may lead to unconsciousness in only a few breaths, with no symptoms at all. some animals are better equipped than humans to detect hypoxia, and these species are less comfortable in low - oxygen environments that result from inert gas exposure, though more averse to co2 exposure. = = physiology = = a typical human breathes between 12 and 20 times per minute at a rate influenced primarily by carbon dioxide concentration, and thus ph, in the blood. with each breath, a volume of about 0. 6 litres is exchanged from an active lung volume of about three litres. the normal composition of the earth's atmosphere is about 78 % nitrogen, 21 % oxygen, and 1 % argon, carbon dioxide, and other gases. after just two or three breaths of nitrogen, the oxygen concentration in the lungs would be low enough for some oxygen already in the bloodstream to exchange back to the lungs and be eliminated by exhalation. unconsciousness in cases of accidental asphyxia can occur within one minute. loss of consciousness results from critical hypoxia, when arterial oxygen saturation is less than 60 %. " at oxygen concentrations [ in air ] of 4 to 6 %, there is loss of consciousness in 40 seconds and death within a few minutes ". at an altitude over 43, 000 ft ( 13, 000 m ), where the ambient oxygen concentration is equivalent to a concentration of 3. 6
Answer:
|
Saturn's rings
| null |
The function of your lungs be impaired on
0. a small sailboat
1. Saturn's rings
2. a windswept beach
3. a pleasant meadow
deep ocean, where most of the water is below 4 Β°c. there are temperature anomalies at active volcanic sites and hydrothermal vents, where deep - water temperatures can significantly exceed 100 Β°c. = = = thermal conductivity = = = water conducts heat around 25 times more efficiently than air. hypothermia, a potentially fatal condition, occurs when the human body's core temperature falls below 35 Β°c. insulating the body's warmth from water is the main purpose of diving suits and exposure suits when used in water temperatures below 25 Β°c. = = = acoustic properties = = = sound is transmitted about 4. 3 times faster in water ( 1, 484 m / s in fresh water ) than in air ( 343 m / s ). the human brain can determine the direction of sound in air by detecting small differences in the time it takes for sound waves in air to reach each of the two ears. for these reasons, divers find it difficult to determine the direction of sound underwater. some animals have adapted to this difference and many use sound to navigate underwater. = = ecosystems = = an aquatic ecosystem is an ecosystem in a body of water. communities of organisms that are dependent on each other and on their environment live in aquatic ecosystems. the two main types of aquatic ecosystems are marine ecosystems and freshwater ecosystems. marine ecosystems are the largest of earth's aquatic ecosystems and are distinguished by waters that have a high salt content. marine waters cover more than 70 % of the surface of the earth and account for more than 97 % of earth's water supply and 90 % of habitable space on earth. marine ecosystems include nearshore systems, such as the salt marshes, mudflats, seagrass meadows, mangroves, rocky intertidal systems and coral reefs. they also extend from the coast to include offshore systems, such as the surface ocean, pelagic ocean waters, the deep sea, oceanic hydrothermal vents, and the sea floor. marine ecosystems are characterized by the biological community of organisms that they are associated with and their physical environment. as the world ocean is the principal component of earth's hydrosphere, it is integral to life, forms part of the carbon cycle, and influences climate and weather patterns. the world ocean is the habitat of 230, 000 known species, but because much of it is unexplored, the number of species that exist in the ocean is much larger, possibly over two million. freshwater ecosystems include lakes and ponds, rivers, streams, springs, aquifers, bogs,
and the tympanic membrane ( eardrum ) can rupture at depths under 10 ft ( 3 m ). the danger of pressure damage is greatest in shallow water because the ratio of pressure change is greatest near the surface of the water. the raised pressure also affects the solution of breathing gases in the tissues over time, and can lead to a range of adverse effects, such as inert gas narcosis, and oxygen toxicity. decompression must be controlled to avoid bubble formation in the tissues and the consequent symptoms of decompression sickness. with a few exceptions, the underwater environment tends to cool the unprotected human body. this heat loss will generally lead to hypothermia eventually. = = = hazards = = = there are several classes of hazards to humans inherent to the underwater environment. absence of breathable gas, which can cause asphyxia, specifically by drowning. ambient pressures which could cause barotrauma, or toxic effects of breathing gas components at raised partial pressures. ambient temperatures which may lead to hypothermia, or in unusual cases, to hyperthermia, due to high rates of heat exchange. solution of inert breathing gas components may lead to decompression sickness if decompression is too rapid. entrainment of diver by moving water in currents and waves can cause injury by impacting the diver against hard objects or moving them to inappropriate depths. dangerous aquatic organisms of various sorts. = = = ambient pressure diving = = = in ambient pressure diving, the diver is directly exposed to the pressure of the surrounding water. the ambient pressure diver may dive on breath - hold, or use breathing apparatus for scuba diving or surface - supplied diving, and the saturation diving technique reduces the risk of decompression sickness ( dcs ) after long - duration deep dives. immersion in water and exposure to cold water and high pressure have physiological effects on the diver which limit the depths and duration possible in ambient pressure diving. breath - hold endurance is a severe limitation, and breathing at high ambient pressure adds further complications, both directly and indirectly. technological solutions have been developed which can greatly extend depth and duration of human ambient pressure dives, and allow useful work to be done underwater. = = = atmospheric pressure diving = = = a diver can be isolated from the ambient pressure by using an atmospheric diving suit ( ads ), which is a small one - person articulated anthropomorphic submersible which resembles a suit of armour, with elaborate pressure
found microbial communities apparently based on the products of reactions between water and the constituents of rocks. these communities have not been studied much, but may be an important part of the global carbon cycle. rock in mines two miles deep also harbour microbes ; these live on minute traces of hydrogen produced in slow oxidizing reactions inside the rock. these metabolic reactions allow life to exist in places with no oxygen or light, an environment that had previously been thought to be devoid of life. the intertidal zone and the photic zone in the oceans are relatively familiar habitat types. however the vast bulk of the ocean is inhospitable to air - breathing humans, with scuba divers limited to the upper 50 m ( 160 ft ) or so. the lower limit for photosynthesis is 100 to 200 m ( 330 to 660 ft ) and below that depth the prevailing conditions include total darkness, high pressure, little oxygen ( in some places ), scarce food resources and extreme cold. this habitat is very challenging to research, and as well as being little - studied, it is vast, with 79 % of the earth's biosphere being at depths greater than 1, 000 m ( 3, 300 ft ). with no plant life, the animals in this zone are either detritivores, reliant on food drifting down from surface layers, or they are predators, feeding on each other. some organisms are pelagic, swimming or drifting in mid - ocean, while others are benthic, living on or near the seabed. their growth rates and metabolisms tend to be slow, their eyes may be very large to detect what little illumination there is, or they may be blind and rely on other sensory inputs. a number of deep sea creatures are bioluminescent ; this serves a variety of functions including predation, protection and social recognition. in general, the bodies of animals living at great depths are adapted to high pressure environments by having pressure - resistant biomolecules and small organic molecules present in their cells known as piezolytes, which give the proteins the flexibility they need. there are also unsaturated fats in their membranes which prevent them from solidifying at low temperatures. hydrothermal vents were first discovered in the ocean depths in 1977. they result from seawater becoming heated after seeping through cracks to places where hot magma is close to the seabed. the under - water hot springs may gush forth at temperatures of over 340 Β°c ( 640 Β°f ) and support unique communities of organisms in their
to maintain two kinds of pressure simultaneously to produce and modify phonation. to produce phonation at all, the lungs must maintain a pressure of 3 β 5 cm h2o higher than the pressure above the glottis. however small and fast adjustments are made to the subglottal pressure to modify speech for suprasegmental features like stress. a number of thoracic muscles are used to make these adjustments. because the lungs and thorax stretch during inhalation, the elastic forces of the lungs alone can produce pressure differentials sufficient for phonation at lung volumes above 50 percent of vital capacity. above 50 percent of vital capacity, the respiratory muscles are used to " check " the elastic forces of the thorax to maintain a stable pressure differential. below that volume, they are used to increase the subglottal pressure by actively exhaling air. during speech, the respiratory cycle is modified to accommodate both linguistic and biological needs. exhalation, usually about 60 percent of the respiratory cycle at rest, is increased to about 90 percent of the respiratory cycle. because metabolic needs are relatively stable, the total volume of air moved in most cases of speech remains about the same as quiet tidal breathing. increases in speech intensity of 18 db ( a loud conversation ) has relatively little impact on the volume of air moved. because their respiratory systems are not as developed as adults, children tend to use a larger proportion of their vital capacity compared to adults, with more deep inhales. = = = source β filter theory = = = the source β filter model of speech is a theory of speech production which explains the link between vocal tract posture and the acoustic consequences. under this model, the vocal tract can be modeled as a noise source coupled onto an acoustic filter. the noise source in many cases is the larynx during the process of voicing, though other noise sources can be modeled in the same way. the shape of the supraglottal vocal tract acts as the filter, and different configurations of the articulators result in different acoustic patterns. these changes are predictable. the vocal tract can be modeled as a sequence of tubes, closed at one end, with varying diameters, and by using equations for acoustic resonance the acoustic effect of an articulatory posture can be derived. the process of inverse filtering uses this principle to analyze the source spectrum produced by the vocal folds during voicing. by taking the inverse of a predicted filter, the acoustic effect of the supraglottal vocal tract can
technically incorrect given respiration continues and the carbon dioxide metabolically produced from the oxygen inhaled prior to inert gas asphyxiation can be exhaled without restriction, which can prevent acidosis and the strong urge to breathe caused by hypercapnia. = = process = = when humans breathe in an asphyxiant gas or any other physiologically inert gas, they exhale carbon dioxide without re - supplying oxygen. physiologically inert gases ( those that have no toxic effect, but merely dilute oxygen ) are generally free of odor and taste. accordingly, the human subject detects little abnormal sensation as the oxygen level falls. this leads to asphyxiation ( death from lack of oxygen ) without the painful and traumatic feeling of suffocation ( the hypercapnic alarm response, which in humans arises mostly from carbon dioxide levels rising ), or the side effects of poisoning. in scuba diving rebreather accidents, a slow decrease in oxygen breathing gas content can produce variable or no sensation. by contrast, suddenly breathing pure inert gas causes oxygen levels in the blood to fall precipitously, and may lead to unconsciousness in only a few breaths, with no symptoms at all. some animals are better equipped than humans to detect hypoxia, and these species are less comfortable in low - oxygen environments that result from inert gas exposure, though more averse to co2 exposure. = = physiology = = a typical human breathes between 12 and 20 times per minute at a rate influenced primarily by carbon dioxide concentration, and thus ph, in the blood. with each breath, a volume of about 0. 6 litres is exchanged from an active lung volume of about three litres. the normal composition of the earth's atmosphere is about 78 % nitrogen, 21 % oxygen, and 1 % argon, carbon dioxide, and other gases. after just two or three breaths of nitrogen, the oxygen concentration in the lungs would be low enough for some oxygen already in the bloodstream to exchange back to the lungs and be eliminated by exhalation. unconsciousness in cases of accidental asphyxia can occur within one minute. loss of consciousness results from critical hypoxia, when arterial oxygen saturation is less than 60 %. " at oxygen concentrations [ in air ] of 4 to 6 %, there is loss of consciousness in 40 seconds and death within a few minutes ". at an altitude over 43, 000 ft ( 13, 000 m ), where the ambient oxygen concentration is equivalent to a concentration of 3. 6
Answer:
|
a pleasant meadow
| 0.3 |
Jackrabbits excel at staying cool because of
0. their adaptations
1. a courthouse
2. a frozen tundra
3. an ocean
##monitoring. temperatures at the water surface, through the water column, and in the lowest levels of the water body ( benthic zone ) can all provide insight into different aspects of an aquatic ecosystem. water temperature is directly affected by climate change and can have negative affects on many aquatic species, such as salmon. salmon spawning is temperature dependant : there is a heat accumulation threshold which must be reached before hatching can occur. post - hatching, salmon live in water within a critical range in temperature, with exposure to temperatures outside of this being potentially lethal. this sensitivity makes them useful indicators of changes in water temperature, hence their use in climate change studies. similarly, daphnia populations have been evidenced as being negatively affected by climate change, as earlier springs have caused hatching periods to de - couple from the peak window of food availability. = = = community make - up = = = species community assemblages and changes therein can help researchers to infer changes in the health of an ecosystem. in typical unpolluted temperate streams of europe and north america, certain insect taxa predominate. mayflies ( ephemeroptera ), caddisflies ( trichoptera ), and stoneflies ( plecoptera ) are the most common insects in these undisturbed streams. in contrast, in rivers disturbed by urbanization, agriculture, forestry, and other perturbations, flies ( diptera ), and especially midges ( family chironomidae ) predominate. = = = local geology = = = surface water can be affected by local geology, as minerals leached from sub - surface rocks can enter surface water bodies and influence water chemistry. examples of this are the werii river ( tigray, ethiopia ), where elevated concentrations of heavy metals have been linked to the underlying slate, and drinking wells in indigenous communities near anchorage, alaska, where high concentrations of arsenic have been linked to the underlying mchugh complex rock formation. = = limitations = = reliance on accurate species identification - when using visual identification in the field, there is the potential for species to be misidentified, which could lead to incorrect analysis and conclusions. to reduce the likelihood of such errors, many monitoring organisations utilise laboratory verification of sample specimens for quality control purposes. species specific - it can be difficult to draw comparisons between results unless the same indicator organism has been used in each study, as every species has an individual niche and associated ideal conditions. even similar species ( as defined by either
the three - spined stickleback, and the mummichog. but asr is not limited to the intertidal environment. most tropical and temperate fish species living in stagnant waters engage in asr during hypoxia. one study looked at 26 species representing eight families of non - air breathing fishes from the north american great plains, and found that all but four of them performed asr during hypoxia. another study looked at 24 species of tropical fish common to the pet trade, from tetras to barbs to cichlids, and found that all of them performed asr. an unusual situation in which asr is performed is during winter, in lakes covered by ice, at the interface between water and ice or near air bubbles trapped underneath the ice. some species may show morphological adaptations, such as a flat head and an upturned mouth, that allow them to perform asr without breaking the water surface ( which would make them more visible to aerial predators ). one example is the mummichog, whose upturned mouth suggests surface feeding, but whose feeding habits are not particularly restricted to the surface. in the tambaqui, a south american species, exposure to hypoxia induces within hours the development of additional blood vessels inside the lower lip, enhancing its ability to take up oxygen during asr. swimming upside down may also help fishes perform asr, as in some upside - down catfish. some species may hold an air bubble within the mouth during asr. this may assist buoyancy as well as increase the oxygen content of the water passing over the bubble on its way to the gills. another way to reduce buoyancy costs is to perform asr on rocks or plants that provide support near the water surface. asr significantly affects survival of fish during severe hypoxia. in the shortfin molly for example, survival was approximately four times higher in individuals able to perform asr as compared to fish not allowed to perform asr during their exposure to extreme hypoxia. asr may be performed more often when the need for oxygen is higher. in the sailfin molly, gestating females ( this species is a livebearer ) spend about 50 % of their time in asr as compared to only 15 % in non - gestating females under the same low levels of oxygen. = = = aerial respiration ( air breathing ) = = = aerial respiration is the'gulping'of air at the surface of water
##rasia and canada. human activity has led to the introduction of non - indigenous species ( nis ) into arctic ecosystems, while changing climate conditions have allowed their survival. shipping has been suggested as the most significant cause of nis introduction, and there are concerns that melting sea ice will allow increased movement of ships through arctic waters. these nis introductions have been labeled a major threat to global biodiversity. the climate change - induced habitat and condition alterations in the arctic have also threatened many different species, including birds that utilize the east asian flyway, a common migratory route. arctic marine biodiversity is additionally threatened by anthropogenic environmental disruptions. furthermore, climate change may alter the efficiency of ecosystem services performed by arctic ecosystems. the arctic has historically been deemed a low risk region for nis invasion due to its harsh conditions, limited food sources, and limited access, which in turn resulted in low chances of survival and growth for the nis. however, due to the recent increases in the amount of human development paired with the melting of the ice due to climate change, the arctic has been experiencing a more temperate climate. this has led to a higher survival rate for southern species or nis since the conditions have become more survivable for these species. in the long - term, the natural ecosystem and food webs are devastated since there are new causes of resource and land depletion. long - term mitigation strategies need to be implemented to help monitor the species richness in areas such as the arctic to understand the trends in biodiversity and how different local strategies that have been implemented either benefit or harm the ecosystem. one example of a mitigation strategy that is potentially beneficial in the protection of local biodiversity by the reduction of nis transport is antifouling. antifouling technologies involve specialized paints being applied to a ship β s hull to slow marine growth on the underwater area. these paints incorporate different biocides such as lead and copper and can help prevent settlement of different nis on vehicles that transport goods to arctic regions. this process indirectly lowers the amount of nis transferred to the arctic by humans, but antifouling does introduce potentially harmful chemicals into the marine environment, which is why the use, quantity, and location of the biocides must be thoroughly considered and mitigated. current scientific and environmental thought leans towards developing and using antifouling strategies that do not involve biocides. arctic biodiversity loss and ways to mitigate it cannot be overly generalized because arctic species interact with varying regional conditions that strongly impact
. the fundamental geographic range of a species is the area it occupies in which environmental conditions are favorable, without restriction from barriers to disperse or colonize. a species will be confined to its realized geographic range when confronting biotic interactions or abiotic barriers that limit dispersal, a more narrow subset of its larger fundamental geographic range. an early study on ecological niches conducted by joseph h. connell analyzed the environmental factors that limit the range of a barnacle ( chthamalus stellatus ) on scotland's isle of cumbrae. in his experiments, connell described the dominant features of c. stellatus niches and provided explanation for their distribution on intertidal zone of the rocky coast of the isle. connell described the upper portion of c. stellatus's range is limited by the barnacle's ability to resist dehydration during periods of low tide. the lower portion of the range was limited by interspecific interactions, namely competition with a cohabiting barnacle species and predation by a snail. by removing the competing b. balanoides, connell showed that c. stellatus was able to extend the lower edge of its realized niche in the absence of competitive exclusion. these experiments demonstrate how biotic and abiotic factors limit the distribution of an organism. = = parameters = = the different dimensions, or plot axes, of a niche represent different biotic and abiotic variables. these factors may include descriptions of the organism's life history, habitat, trophic position ( place in the food chain ), and geographic range. according to the competitive exclusion principle, no two species can occupy the same niche in the same environment for a long time. the parameters of a realized niche are described by the realized niche width of that species. some plants and animals, called specialists, need specific habitats and surroundings to survive, such as the spotted owl, which lives specifically in old growth forests. other plants and animals, called generalists, are not as particular and can survive in a range of conditions, for example the dandelion. = = see also = = ontogenetic niche shift marginal distribution ( biology ) fitness landscape niche differentiation overpopulation phylogenetic niche conservatism unified neutral theory of biodiversity character displacement = = references = = = = further reading = = = = external links = = concept of ecological niche ontology of the niche niche restriction and segregation vacant niche latitude - niche width hypothesis walter, g. h. ( may 1991 ). " what is resource partitioning? ".
. the fundamental geographic range of a species is the area it occupies in which environmental conditions are favorable, without restriction from barriers to disperse or colonize. a species will be confined to its realized geographic range when confronting biotic interactions or abiotic barriers that limit dispersal, a more narrow subset of its larger fundamental geographic range. an early study on ecological niches conducted by joseph h. connell analyzed the environmental factors that limit the range of a barnacle ( chthamalus stellatus ) on scotland's isle of cumbrae. in his experiments, connell described the dominant features of c. stellatus niches and provided explanation for their distribution on intertidal zone of the rocky coast of the isle. connell described the upper portion of c. stellatus's range is limited by the barnacle's ability to resist dehydration during periods of low tide. the lower portion of the range was limited by interspecific interactions, namely competition with a cohabiting barnacle species and predation by a snail. by removing the competing b. balanoides, connell showed that c. stellatus was able to extend the lower edge of its realized niche in the absence of competitive exclusion. these experiments demonstrate how biotic and abiotic factors limit the distribution of an organism. = = parameters = = the different dimensions, or plot axes, of a niche represent different biotic and abiotic variables. these factors may include descriptions of the organism's life history, habitat, trophic position ( place in the food chain ), and geographic range. according to the competitive exclusion principle, no two species can occupy the same niche in the same environment for a long time. the parameters of a realized niche are described by the realized niche width of that species. some plants and animals, called specialists, need specific habitats and surroundings to survive, such as the spotted owl, which lives specifically in old growth forests. other plants and animals, called generalists, are not as particular and can survive in a range of conditions, for example the dandelion. = = see also = = ontogenetic niche shift marginal distribution ( biology ) fitness landscape niche differentiation overpopulation phylogenetic niche conservatism unified neutral theory of biodiversity character displacement = = references = = = = further reading = = = = external links = = concept of ecological niche ontology of the niche niche restriction and segregation vacant niche latitude - niche width hypothesis walter, g. h. ( may 1991 ). " what is resource partitioning? ".
Answer:
|
their adaptations
| null |
Jackrabbits excel at staying cool because of
0. their adaptations
1. a courthouse
2. a frozen tundra
3. an ocean
##monitoring. temperatures at the water surface, through the water column, and in the lowest levels of the water body ( benthic zone ) can all provide insight into different aspects of an aquatic ecosystem. water temperature is directly affected by climate change and can have negative affects on many aquatic species, such as salmon. salmon spawning is temperature dependant : there is a heat accumulation threshold which must be reached before hatching can occur. post - hatching, salmon live in water within a critical range in temperature, with exposure to temperatures outside of this being potentially lethal. this sensitivity makes them useful indicators of changes in water temperature, hence their use in climate change studies. similarly, daphnia populations have been evidenced as being negatively affected by climate change, as earlier springs have caused hatching periods to de - couple from the peak window of food availability. = = = community make - up = = = species community assemblages and changes therein can help researchers to infer changes in the health of an ecosystem. in typical unpolluted temperate streams of europe and north america, certain insect taxa predominate. mayflies ( ephemeroptera ), caddisflies ( trichoptera ), and stoneflies ( plecoptera ) are the most common insects in these undisturbed streams. in contrast, in rivers disturbed by urbanization, agriculture, forestry, and other perturbations, flies ( diptera ), and especially midges ( family chironomidae ) predominate. = = = local geology = = = surface water can be affected by local geology, as minerals leached from sub - surface rocks can enter surface water bodies and influence water chemistry. examples of this are the werii river ( tigray, ethiopia ), where elevated concentrations of heavy metals have been linked to the underlying slate, and drinking wells in indigenous communities near anchorage, alaska, where high concentrations of arsenic have been linked to the underlying mchugh complex rock formation. = = limitations = = reliance on accurate species identification - when using visual identification in the field, there is the potential for species to be misidentified, which could lead to incorrect analysis and conclusions. to reduce the likelihood of such errors, many monitoring organisations utilise laboratory verification of sample specimens for quality control purposes. species specific - it can be difficult to draw comparisons between results unless the same indicator organism has been used in each study, as every species has an individual niche and associated ideal conditions. even similar species ( as defined by either
the three - spined stickleback, and the mummichog. but asr is not limited to the intertidal environment. most tropical and temperate fish species living in stagnant waters engage in asr during hypoxia. one study looked at 26 species representing eight families of non - air breathing fishes from the north american great plains, and found that all but four of them performed asr during hypoxia. another study looked at 24 species of tropical fish common to the pet trade, from tetras to barbs to cichlids, and found that all of them performed asr. an unusual situation in which asr is performed is during winter, in lakes covered by ice, at the interface between water and ice or near air bubbles trapped underneath the ice. some species may show morphological adaptations, such as a flat head and an upturned mouth, that allow them to perform asr without breaking the water surface ( which would make them more visible to aerial predators ). one example is the mummichog, whose upturned mouth suggests surface feeding, but whose feeding habits are not particularly restricted to the surface. in the tambaqui, a south american species, exposure to hypoxia induces within hours the development of additional blood vessels inside the lower lip, enhancing its ability to take up oxygen during asr. swimming upside down may also help fishes perform asr, as in some upside - down catfish. some species may hold an air bubble within the mouth during asr. this may assist buoyancy as well as increase the oxygen content of the water passing over the bubble on its way to the gills. another way to reduce buoyancy costs is to perform asr on rocks or plants that provide support near the water surface. asr significantly affects survival of fish during severe hypoxia. in the shortfin molly for example, survival was approximately four times higher in individuals able to perform asr as compared to fish not allowed to perform asr during their exposure to extreme hypoxia. asr may be performed more often when the need for oxygen is higher. in the sailfin molly, gestating females ( this species is a livebearer ) spend about 50 % of their time in asr as compared to only 15 % in non - gestating females under the same low levels of oxygen. = = = aerial respiration ( air breathing ) = = = aerial respiration is the'gulping'of air at the surface of water
##rasia and canada. human activity has led to the introduction of non - indigenous species ( nis ) into arctic ecosystems, while changing climate conditions have allowed their survival. shipping has been suggested as the most significant cause of nis introduction, and there are concerns that melting sea ice will allow increased movement of ships through arctic waters. these nis introductions have been labeled a major threat to global biodiversity. the climate change - induced habitat and condition alterations in the arctic have also threatened many different species, including birds that utilize the east asian flyway, a common migratory route. arctic marine biodiversity is additionally threatened by anthropogenic environmental disruptions. furthermore, climate change may alter the efficiency of ecosystem services performed by arctic ecosystems. the arctic has historically been deemed a low risk region for nis invasion due to its harsh conditions, limited food sources, and limited access, which in turn resulted in low chances of survival and growth for the nis. however, due to the recent increases in the amount of human development paired with the melting of the ice due to climate change, the arctic has been experiencing a more temperate climate. this has led to a higher survival rate for southern species or nis since the conditions have become more survivable for these species. in the long - term, the natural ecosystem and food webs are devastated since there are new causes of resource and land depletion. long - term mitigation strategies need to be implemented to help monitor the species richness in areas such as the arctic to understand the trends in biodiversity and how different local strategies that have been implemented either benefit or harm the ecosystem. one example of a mitigation strategy that is potentially beneficial in the protection of local biodiversity by the reduction of nis transport is antifouling. antifouling technologies involve specialized paints being applied to a ship β s hull to slow marine growth on the underwater area. these paints incorporate different biocides such as lead and copper and can help prevent settlement of different nis on vehicles that transport goods to arctic regions. this process indirectly lowers the amount of nis transferred to the arctic by humans, but antifouling does introduce potentially harmful chemicals into the marine environment, which is why the use, quantity, and location of the biocides must be thoroughly considered and mitigated. current scientific and environmental thought leans towards developing and using antifouling strategies that do not involve biocides. arctic biodiversity loss and ways to mitigate it cannot be overly generalized because arctic species interact with varying regional conditions that strongly impact
. the fundamental geographic range of a species is the area it occupies in which environmental conditions are favorable, without restriction from barriers to disperse or colonize. a species will be confined to its realized geographic range when confronting biotic interactions or abiotic barriers that limit dispersal, a more narrow subset of its larger fundamental geographic range. an early study on ecological niches conducted by joseph h. connell analyzed the environmental factors that limit the range of a barnacle ( chthamalus stellatus ) on scotland's isle of cumbrae. in his experiments, connell described the dominant features of c. stellatus niches and provided explanation for their distribution on intertidal zone of the rocky coast of the isle. connell described the upper portion of c. stellatus's range is limited by the barnacle's ability to resist dehydration during periods of low tide. the lower portion of the range was limited by interspecific interactions, namely competition with a cohabiting barnacle species and predation by a snail. by removing the competing b. balanoides, connell showed that c. stellatus was able to extend the lower edge of its realized niche in the absence of competitive exclusion. these experiments demonstrate how biotic and abiotic factors limit the distribution of an organism. = = parameters = = the different dimensions, or plot axes, of a niche represent different biotic and abiotic variables. these factors may include descriptions of the organism's life history, habitat, trophic position ( place in the food chain ), and geographic range. according to the competitive exclusion principle, no two species can occupy the same niche in the same environment for a long time. the parameters of a realized niche are described by the realized niche width of that species. some plants and animals, called specialists, need specific habitats and surroundings to survive, such as the spotted owl, which lives specifically in old growth forests. other plants and animals, called generalists, are not as particular and can survive in a range of conditions, for example the dandelion. = = see also = = ontogenetic niche shift marginal distribution ( biology ) fitness landscape niche differentiation overpopulation phylogenetic niche conservatism unified neutral theory of biodiversity character displacement = = references = = = = further reading = = = = external links = = concept of ecological niche ontology of the niche niche restriction and segregation vacant niche latitude - niche width hypothesis walter, g. h. ( may 1991 ). " what is resource partitioning? ".
. the fundamental geographic range of a species is the area it occupies in which environmental conditions are favorable, without restriction from barriers to disperse or colonize. a species will be confined to its realized geographic range when confronting biotic interactions or abiotic barriers that limit dispersal, a more narrow subset of its larger fundamental geographic range. an early study on ecological niches conducted by joseph h. connell analyzed the environmental factors that limit the range of a barnacle ( chthamalus stellatus ) on scotland's isle of cumbrae. in his experiments, connell described the dominant features of c. stellatus niches and provided explanation for their distribution on intertidal zone of the rocky coast of the isle. connell described the upper portion of c. stellatus's range is limited by the barnacle's ability to resist dehydration during periods of low tide. the lower portion of the range was limited by interspecific interactions, namely competition with a cohabiting barnacle species and predation by a snail. by removing the competing b. balanoides, connell showed that c. stellatus was able to extend the lower edge of its realized niche in the absence of competitive exclusion. these experiments demonstrate how biotic and abiotic factors limit the distribution of an organism. = = parameters = = the different dimensions, or plot axes, of a niche represent different biotic and abiotic variables. these factors may include descriptions of the organism's life history, habitat, trophic position ( place in the food chain ), and geographic range. according to the competitive exclusion principle, no two species can occupy the same niche in the same environment for a long time. the parameters of a realized niche are described by the realized niche width of that species. some plants and animals, called specialists, need specific habitats and surroundings to survive, such as the spotted owl, which lives specifically in old growth forests. other plants and animals, called generalists, are not as particular and can survive in a range of conditions, for example the dandelion. = = see also = = ontogenetic niche shift marginal distribution ( biology ) fitness landscape niche differentiation overpopulation phylogenetic niche conservatism unified neutral theory of biodiversity character displacement = = references = = = = further reading = = = = external links = = concept of ecological niche ontology of the niche niche restriction and segregation vacant niche latitude - niche width hypothesis walter, g. h. ( may 1991 ). " what is resource partitioning? ".
Answer:
|
a courthouse
| 0.3 |
If you had a hammer, you would find ____ nails made of ____
0. wood; wood
1. iron; wood
2. wood; iron
3. iron; iron
an archaeological feature can be used to partially determine the function of each region of the feature. in particular, areas with higher concentrations of hammerscale flakes suggest the presence of an anvil of a hearth as flakes were produced during either the hammering of the iron objects or broken off while heating iron of different stages of purity. in contrast, the presence of large amounts of slag within a confirmed smithy or smelter is less conclusive, though it might indicate waste piles. beyond the distribution, the chemical composition and physical characteristics of specific samples of hammerscale can aid archaeologists in determining the purpose of an ironworking feature. in particular, certain samples, such as spheroidal hammerscale, are only produced during certain earlier stages of the iron purification process, providing evidence of smelting activities. the more recognizable, lustrous, and larger flake forms arise almost exclusively from hammering of completed iron objects. by studying the different types of hammerscale present and its prevalence, a trained metallurgist can map out both the purpose of each area of the feature as well as the larger purpose of the entire feature ( i. e. smithy or smelter ). = = = collection techniques = = = due its small size and often darker color, hammerscale is difficult to discover while carrying out simple archaeological processes, such as dry or wet sieving. instead, when there is clear evidence that a site, such as a pit - house, involved some form of ironworking, archaeologists are advised to form a grid and collect soil from the site for further analysis. this allows for trained metallurgists to analyze the type of hammerscale and their prevalence within the structure. this is still a rare practice for lack of time or expertise, but nevertheless recommended and if untenable, soil samples should still be run over with a magnet so as to collect hammerscale flakes on site. = = = history and sample excavations = = = seeing as it is a seemingly natural part of earlier ironworking techniques, hammerscale finds have been noted at numerous archaeological excavations in numerous world regions such as northern europe, great britain, and the levant. the earliest mention of hammerscale in an archaeological context derived from a 1941 study of roman - built fort in great britain, located on hadrian β s wall. an excavation in 1960 of a roman ironworking site in norfolk also yielded hammer scale. in more recent excavations, hammerscale recovery has been conducted in a more systematic manner, using the grid
hammerscale, also written hammer scale, is a flaky or spheroidal byproduct of the iron forging process ( for modern equivalent, see mill scale ). hammerscale is almost universally recovered from archaeological excavations in areas where iron ore was refined and forged. hammerscale β s magnetic character also aids in its recovery and in mapping larger features by means of magnetic susceptibility surveys. hammerscale can provide vital information about an archeological site such as the function of the feature. = = description = = = = = physical attributes = = = hammerscale appears in two forms : flakes and hollow spheroids. the flakes can vary greatly in appearance and size ; however, their color ranges from a dark black to a lustrous blue or grey and their thickness from one to five millimeters. like the flakes, the spheroids are also quite small but their size can vary. their color tends to range from grey to a dark black or blue. = = = chemical composition = = = the chemical composition of hammerscale is disputed and varies greatly. most sources agree that hammerscale is composed of some form of iron oxide. magnetite is a generally accepted form, giving hammerscale its notable magnetic character. however, hammerscale β s chemical composition can change depending on from which stage in the iron purification process it derives ; for flakes and spheroids from early stages, the composition will be largely mixed whereas flakes from late stages will be purer iron oxide forms. ultimately, some still argue that the chemical components of hammerscale besides iron vary widely beyond ionized oxygen to form a metal oxide. = = production = = flake hammerscale forms due to the rapid oxidation of hot iron in air. a heated piece of iron will develop an external layer of iron oxide which then may separate from the original piece due to a hammer strike or differential thermal contraction. flake hammerscale is produced in large quantities during multiple stages of the smithing process. to create the pure iron necessary for forging, a smith must first purify the iron ore. the smelting of ore creates a " bloom ", a porous mixture of slag and metal. the smith then repeatedly heats and hammers the bloom to remove impurities. this technique creates hammerscale of varying composition. as the purification process continues, the hammerscale β s iron content increases. additional hammerscale is produced during the forging of the pure iron from
in great britain, located on hadrian β s wall. an excavation in 1960 of a roman ironworking site in norfolk also yielded hammer scale. in more recent excavations, hammerscale recovery has been conducted in a more systematic manner, using the grid method noted above. for example, in an excavation in 1992, by means of establishing a grid and collecting local samples, the former location of a hearth and an anvil was determined despite the lack of the direct remains of either. arne jouttijarvi writes of three sites at which hammerscale deposits and concentration were used to map the areas of smithies in viking age pithouses in modern - day denmark and norway. for example, he writes how the " blacksmith himself shielded the floor where he stood, leaving a'shadow'in the distribution of hammer scale. " therefore, the distribution of hammerscale is not only able to aid in the location items within a workshop, but can also inform scholars of where the smiths themselves stood. smithy discoveries involving hammerscale are well documented and generally a high presence of hammerscale is considered sufficient to identify a find as a smithy. there is even evidence of hammerscale at a bronze age site in upper bucklebury, west berkshire, suggesting early ironworking in britain. = = references = =
forging is a manufacturing process involving the shaping of metal using localized compressive forces. the blows are delivered with a hammer ( often a power hammer ) or a die. forging is often classified according to the temperature at which it is performed : cold forging ( a type of cold working ), warm forging, or hot forging ( a type of hot working ). for the latter two, the metal is heated, usually in a forge. forged parts can range in weight from less than a kilogram to hundreds of metric tons. forging has been done by smiths for millennia ; the traditional products were kitchenware, hardware, hand tools, edged weapons, cymbals, and jewellery. since the industrial revolution, forged parts are widely used in mechanisms and machines wherever a component requires high strength ; such forgings usually require further processing ( such as machining ) to achieve a finished part. today, forging is a major worldwide industry. = = history = = forging is one of the oldest known metalworking processes. traditionally, forging was performed by a smith using hammer and anvil, though introducing water power to the production and working of iron in the 12th century allowed the use of large trip hammers or power hammers that increased the amount and size of iron that could be produced and forged. the smithy or forge has evolved over centuries to become a facility with engineered processes, production equipment, tooling, raw materials and products to meet the demands of modern industry. in modern times, industrial forging is done either with presses or with hammers powered by compressed air, electricity, hydraulics or steam. these hammers may have reciprocating weights in the thousands of pounds. smaller power hammers, 500 lb ( 230 kg ) or less reciprocating weight, and hydraulic presses are common in art smithies as well. some steam hammers remain in use, but they became obsolete with the availability of the other, more convenient, power sources. = = processes = = there are many different kinds of forging processes available ; however, they can be grouped into three main classes : drawn out : length increases, cross - section decreases upset : length decreases, cross - section increases squeezed in closed compression dies : produces multidirectional flow common forging processes include : roll forging, swaging, cogging, open - die forging, impression - die forging ( closed die forging ), press forging, cold forging, automatic hot forging and upsetting.
or larger excavations. = = = = soil nailing = = = = soil nailing is a technique in which soil slopes, excavations or retaining walls are reinforced by the insertion of relatively slender elements β normally steel reinforcing bars. the bars are usually installed into a pre - drilled hole and then grouted into place or drilled and grouted simultaneously. they are usually installed untensioned at a slight downward inclination. a rigid or flexible facing ( often sprayed concrete ) or isolated soil nail heads may be used at the surface. = = = shoring in ships = = = shoring is used on board when damage has been caused to a vessel's integrity, and to hold leak - stopping devices in place to reduce or stop incoming water. generally consists of timber 100 mm x 100 mm and used in conjunction with wedges, to further jam shoring in place, pad pieces to spread the load and dogs to hold it together. also used on board is mechanical shoring as a quick, temporary solution, however it isn't favoured due to its inability to move with the vessel. = = = = proud = = = = this consists of a timber member jammed on a pad piece on either the deck or deck head depending on water levels in the compartment and a strong point, this is called the proud. then there is a horizontal timber cut to size to fit between this and what it is shoring up, e. g. a splinter box, bulkhead or door. timber wedges are then used to tighten up the structure if necessary. = = = = vertical shoring = = = = this is to support a hatch or splint box on the deck, consisting of a vertical timber between the deck and deck head, with two wedges used opposing each other to tighten it. pad pieces are used to spread the load on weak structures. = = = shoring in air freight = = = shoring is a term used in the process of air freight container and pallet ( uld ) buildup, e. g. making sure that the cargo placed in containers and on pallets is packed securely and efficiently. specifically, shoring is done to affix cargo to the uld and adapt different form factors of cargo items to maximize the use of the available uld volume. typically, wooden beams and various forms of boards are used. most often, shoring material is re - used but as the airfreight industry uses high - quality timber, shoring material often disappears and is a non -
Answer:
|
iron; iron
| null |
If you had a hammer, you would find ____ nails made of ____
0. wood; wood
1. iron; wood
2. wood; iron
3. iron; iron
an archaeological feature can be used to partially determine the function of each region of the feature. in particular, areas with higher concentrations of hammerscale flakes suggest the presence of an anvil of a hearth as flakes were produced during either the hammering of the iron objects or broken off while heating iron of different stages of purity. in contrast, the presence of large amounts of slag within a confirmed smithy or smelter is less conclusive, though it might indicate waste piles. beyond the distribution, the chemical composition and physical characteristics of specific samples of hammerscale can aid archaeologists in determining the purpose of an ironworking feature. in particular, certain samples, such as spheroidal hammerscale, are only produced during certain earlier stages of the iron purification process, providing evidence of smelting activities. the more recognizable, lustrous, and larger flake forms arise almost exclusively from hammering of completed iron objects. by studying the different types of hammerscale present and its prevalence, a trained metallurgist can map out both the purpose of each area of the feature as well as the larger purpose of the entire feature ( i. e. smithy or smelter ). = = = collection techniques = = = due its small size and often darker color, hammerscale is difficult to discover while carrying out simple archaeological processes, such as dry or wet sieving. instead, when there is clear evidence that a site, such as a pit - house, involved some form of ironworking, archaeologists are advised to form a grid and collect soil from the site for further analysis. this allows for trained metallurgists to analyze the type of hammerscale and their prevalence within the structure. this is still a rare practice for lack of time or expertise, but nevertheless recommended and if untenable, soil samples should still be run over with a magnet so as to collect hammerscale flakes on site. = = = history and sample excavations = = = seeing as it is a seemingly natural part of earlier ironworking techniques, hammerscale finds have been noted at numerous archaeological excavations in numerous world regions such as northern europe, great britain, and the levant. the earliest mention of hammerscale in an archaeological context derived from a 1941 study of roman - built fort in great britain, located on hadrian β s wall. an excavation in 1960 of a roman ironworking site in norfolk also yielded hammer scale. in more recent excavations, hammerscale recovery has been conducted in a more systematic manner, using the grid
hammerscale, also written hammer scale, is a flaky or spheroidal byproduct of the iron forging process ( for modern equivalent, see mill scale ). hammerscale is almost universally recovered from archaeological excavations in areas where iron ore was refined and forged. hammerscale β s magnetic character also aids in its recovery and in mapping larger features by means of magnetic susceptibility surveys. hammerscale can provide vital information about an archeological site such as the function of the feature. = = description = = = = = physical attributes = = = hammerscale appears in two forms : flakes and hollow spheroids. the flakes can vary greatly in appearance and size ; however, their color ranges from a dark black to a lustrous blue or grey and their thickness from one to five millimeters. like the flakes, the spheroids are also quite small but their size can vary. their color tends to range from grey to a dark black or blue. = = = chemical composition = = = the chemical composition of hammerscale is disputed and varies greatly. most sources agree that hammerscale is composed of some form of iron oxide. magnetite is a generally accepted form, giving hammerscale its notable magnetic character. however, hammerscale β s chemical composition can change depending on from which stage in the iron purification process it derives ; for flakes and spheroids from early stages, the composition will be largely mixed whereas flakes from late stages will be purer iron oxide forms. ultimately, some still argue that the chemical components of hammerscale besides iron vary widely beyond ionized oxygen to form a metal oxide. = = production = = flake hammerscale forms due to the rapid oxidation of hot iron in air. a heated piece of iron will develop an external layer of iron oxide which then may separate from the original piece due to a hammer strike or differential thermal contraction. flake hammerscale is produced in large quantities during multiple stages of the smithing process. to create the pure iron necessary for forging, a smith must first purify the iron ore. the smelting of ore creates a " bloom ", a porous mixture of slag and metal. the smith then repeatedly heats and hammers the bloom to remove impurities. this technique creates hammerscale of varying composition. as the purification process continues, the hammerscale β s iron content increases. additional hammerscale is produced during the forging of the pure iron from
in great britain, located on hadrian β s wall. an excavation in 1960 of a roman ironworking site in norfolk also yielded hammer scale. in more recent excavations, hammerscale recovery has been conducted in a more systematic manner, using the grid method noted above. for example, in an excavation in 1992, by means of establishing a grid and collecting local samples, the former location of a hearth and an anvil was determined despite the lack of the direct remains of either. arne jouttijarvi writes of three sites at which hammerscale deposits and concentration were used to map the areas of smithies in viking age pithouses in modern - day denmark and norway. for example, he writes how the " blacksmith himself shielded the floor where he stood, leaving a'shadow'in the distribution of hammer scale. " therefore, the distribution of hammerscale is not only able to aid in the location items within a workshop, but can also inform scholars of where the smiths themselves stood. smithy discoveries involving hammerscale are well documented and generally a high presence of hammerscale is considered sufficient to identify a find as a smithy. there is even evidence of hammerscale at a bronze age site in upper bucklebury, west berkshire, suggesting early ironworking in britain. = = references = =
forging is a manufacturing process involving the shaping of metal using localized compressive forces. the blows are delivered with a hammer ( often a power hammer ) or a die. forging is often classified according to the temperature at which it is performed : cold forging ( a type of cold working ), warm forging, or hot forging ( a type of hot working ). for the latter two, the metal is heated, usually in a forge. forged parts can range in weight from less than a kilogram to hundreds of metric tons. forging has been done by smiths for millennia ; the traditional products were kitchenware, hardware, hand tools, edged weapons, cymbals, and jewellery. since the industrial revolution, forged parts are widely used in mechanisms and machines wherever a component requires high strength ; such forgings usually require further processing ( such as machining ) to achieve a finished part. today, forging is a major worldwide industry. = = history = = forging is one of the oldest known metalworking processes. traditionally, forging was performed by a smith using hammer and anvil, though introducing water power to the production and working of iron in the 12th century allowed the use of large trip hammers or power hammers that increased the amount and size of iron that could be produced and forged. the smithy or forge has evolved over centuries to become a facility with engineered processes, production equipment, tooling, raw materials and products to meet the demands of modern industry. in modern times, industrial forging is done either with presses or with hammers powered by compressed air, electricity, hydraulics or steam. these hammers may have reciprocating weights in the thousands of pounds. smaller power hammers, 500 lb ( 230 kg ) or less reciprocating weight, and hydraulic presses are common in art smithies as well. some steam hammers remain in use, but they became obsolete with the availability of the other, more convenient, power sources. = = processes = = there are many different kinds of forging processes available ; however, they can be grouped into three main classes : drawn out : length increases, cross - section decreases upset : length decreases, cross - section increases squeezed in closed compression dies : produces multidirectional flow common forging processes include : roll forging, swaging, cogging, open - die forging, impression - die forging ( closed die forging ), press forging, cold forging, automatic hot forging and upsetting.
or larger excavations. = = = = soil nailing = = = = soil nailing is a technique in which soil slopes, excavations or retaining walls are reinforced by the insertion of relatively slender elements β normally steel reinforcing bars. the bars are usually installed into a pre - drilled hole and then grouted into place or drilled and grouted simultaneously. they are usually installed untensioned at a slight downward inclination. a rigid or flexible facing ( often sprayed concrete ) or isolated soil nail heads may be used at the surface. = = = shoring in ships = = = shoring is used on board when damage has been caused to a vessel's integrity, and to hold leak - stopping devices in place to reduce or stop incoming water. generally consists of timber 100 mm x 100 mm and used in conjunction with wedges, to further jam shoring in place, pad pieces to spread the load and dogs to hold it together. also used on board is mechanical shoring as a quick, temporary solution, however it isn't favoured due to its inability to move with the vessel. = = = = proud = = = = this consists of a timber member jammed on a pad piece on either the deck or deck head depending on water levels in the compartment and a strong point, this is called the proud. then there is a horizontal timber cut to size to fit between this and what it is shoring up, e. g. a splinter box, bulkhead or door. timber wedges are then used to tighten up the structure if necessary. = = = = vertical shoring = = = = this is to support a hatch or splint box on the deck, consisting of a vertical timber between the deck and deck head, with two wedges used opposing each other to tighten it. pad pieces are used to spread the load on weak structures. = = = shoring in air freight = = = shoring is a term used in the process of air freight container and pallet ( uld ) buildup, e. g. making sure that the cargo placed in containers and on pallets is packed securely and efficiently. specifically, shoring is done to affix cargo to the uld and adapt different form factors of cargo items to maximize the use of the available uld volume. typically, wooden beams and various forms of boards are used. most often, shoring material is re - used but as the airfreight industry uses high - quality timber, shoring material often disappears and is a non -
Answer:
|
wood; wood
| 0.3 |
Like humans, when some animals get hot, they do what in order to lower their body temperature
0. spend money
1. raise blood temperature
2. fly away
3. perspire
large temperature changes adapt to higher temperatures through a variety of methods. in green crabs, the process of initial warming results in an increase of oxygen consumption and heart rate, accompanied by a decrease in stroke volume and haemolymph oxygen partial pressure. as this warming continues, dissolved oxygen levels decrease below the threshold for full haemocyanin oxygen saturation. this heating then progressively releases haemocyanin - bound oxygen, saving energy in oxygen transport and resulting in an associated leveling off of metabolic rate. key to maintaining homeostasis, individual thermoregulation is the ability to maintain internal body temperature in humans, the most recognizable eurytherm. in humans, deep - body temperature is regulated by cutaneous blood flow, which maintains this temperature despite changes in the external environment. homo sapiens'ability to survive in different ambient temperatures is a key factor in the species success, and one cited reason for why homo sapiens eventually outcompeted neanderthals ( homo neanderthalensis ). humans have two major forms of thermogenesis. the first is shivering, in which a warm - blooded creature produces involuntary contraction of skeletal muscle in order to produce heat. in addition, shivering also signals the body to produce irisin, a hormone that has been shown to convert white fat to brown fat, which is used in non - shivering thermogenesis, the second type of human thermogensis. non - shivering thermogenesis occurs in the brown fat, which contains the uncoupling protein thermogenin. this protein decreases the proton gradient generated in oxidative phosphorylation during the synthesis of atp, uncoupling the electron transport in the mitochondrion from the production of chemical energy ( atp ). this creation of a gradient across the mitochondrial membrane causes energy to be lost as heat. on the other hand, humans have only one method of cooling themselves, biologically speaking : sweat evaporation. cutaneous eccrine sweat glands produce sweat, which is made up of mostly water with a small amount of ions. evaporation of this sweat helps to cool the blood beneath the skin, resulting in a cooling of deep - body temperature. while some organisms are eurythermic due to their ability to regulate internal body temperature, like humans, others have wildly different methods of extreme temperature tolerance. tardigrades are able to enter an anhydrobiotic state, often called a tun, in order to both prevent desiccation and
in its different aspects causes an animal to limit its movement ; the metabolic energy not expended in activity is diverted to the fever responses, which involves raising body temperature. this also limits an animal's exposure to predators while it is cognitively and physically impaired. = = = specific advantages = = = the individual components of sickness behavior have specific individual advantages. anorexia limits food ingestion and therefore reduces the availability of iron in the gut ( and from gut absorption ). iron may aid bacterial reproduction, so its reduction is useful during sickness. plasma concentrations of iron are lowered for this anti - bacterial reason in fever. lowered threshold for pain ensures that an animal is attentive that it does not place pressure on injured and inflamed tissues that might disrupt their healing. reduced grooming is adaptive since it reduces water loss. = = = inclusive fitness advantages = = = according to the'eyam hypothesis ', sickness behavior, by promoting immobility and social disinterest, limits the direct contacts of individuals with their relatives. by reducing eating and drinking, it limits diarrhea and defecation, reducing environmental contamination. by reducing self - grooming and changing stance, gait and vocalization, it also signals poor health to kin. all in all, sickness behavior reduces the rate of further infection, a trait that is likely propagated by kin selection. = = = social advantage = = = humans helped each other in case of sickness or injury throughout their hunter - gatherer past and afterwards. convincing others of being badly in need of relief, assistance, and care heightened the chance of survival of the sick individual. high direct costs, such as energy spent on fever and potential harm caused by high body temperatures, and high opportunity costs, as caused by inactivity, social disinterest, and lack of appetite, make sickness behavior a highly costly and therefore credible signal of need. = = immune control = = lipopolysaccharides trigger the immune system to produce proinflammatory cytokines il - 1, il - 6, and tumor necrosis factor ( tnf ). these peripherally released cytokines act on the brain via a fast transmission pathway involving primary input through the vagus nerves, and a slow transmission pathway involving cytokines originating from the choroid plexus and circumventricular organs and diffusing into the brain parenchyma by volume transmission. peripheral cytokines are capable of entering the brain directly but
a medical practitioner. = = mechanism = = sweating allows the body to regulate its temperature. sweating is controlled from a center in the preoptic and anterior regions of the brain's hypothalamus, where thermosensitive neurons are located. the heat - regulatory function of the hypothalamus is also affected by inputs from temperature receptors in the skin. high skin temperature reduces the hypothalamic set point for sweating and increases the gain of the hypothalamic feedback system in response to variations in core temperature. overall, however, the sweating response to a rise in hypothalamic ('core') temperature is much larger than the response to the same increase in average skin temperature. sweating causes a decrease in core temperature through evaporative cooling at the skin surface. as high energy molecules evaporate from the skin, releasing energy absorbed from the body, the skin and superficial vessels decrease in temperature. cooled venous blood then returns to the body's core and counteracts rising core temperatures. there are two situations in which the nerves will stimulate the sweat glands, causing perspiration : during physical heat and during emotional stress. in general, emotionally induced sweating is restricted to palms, soles, armpits, and sometimes the forehead, while physical heat - induced sweating occurs throughout the body. people have an average of two to four million sweat glands, but how much sweat is released by each gland is determined by many factors, including sex, genetics, environmental conditions, age and fitness level. two of the major contributors to sweat rate are an individual's fitness level and weight. if an individual weighs more, sweat rate is likely to increase because the body must exert more energy to function and there is more body mass to cool down. on the other hand, a fit person will start sweating earlier and more readily. as someone becomes fit, the body becomes more efficient at regulating the body's temperature and sweat glands adapt along with the body's other systems. human sweat is not pure water ; though it contains no protein, it always contains a small amount ( 0. 2 β 1 % ) of solute. when a person moves from a cold climate to a hot climate, adaptive changes occur in the sweating mechanisms of the person. this process is referred to as acclimatization : the maximum rate of sweating increases and its solute composition decreases. the volume of water lost in sweat daily is highly variable, ranging from 100 to 8, 000 millilitres
oil refining, steel making or glass making are major sources of waste heat. = = = electronics = = = although small in terms of power, the disposal of waste heat from microchips and other electronic components, represents a significant engineering challenge. this necessitates the use of fans, heatsinks, etc. to dispose of the heat. for example, data centers use electronic components that consume electricity for computing, storage and networking. the french cnrs explains a data center is like a resistor and most of the energy it consumes is transformed into heat and requires cooling systems. = = = biological = = = humans, like all animals, produce heat as a result of metabolism. in warm conditions, this heat exceeds a level required for homeostasis in warm - blooded animals, and is disposed of by various thermoregulation methods such as sweating and panting. = = disposal = = low temperature heat contains very little capacity to do work ( exergy ), so the heat is qualified as waste heat and rejected to the environment. economically most convenient is the rejection of such heat to water from a sea, lake or river. if sufficient cooling water is not available, the plant can be equipped with a cooling tower or air cooler to reject the waste heat into the atmosphere. in some cases it is possible to use waste heat, for instance in district heating systems. = = uses = = = = = conversion to electricity = = = there are many different approaches to transfer thermal energy to electricity, and the technologies to do so have existed for several decades. an established approach is by using a thermoelectric device, where a change in temperature across a semiconductor material creates a voltage through a phenomenon known as the seebeck effect. a related approach is the use of thermogalvanic cells, where a temperature difference gives rise to an electric current in an electrochemical cell. the organic rankine cycle, offered by companies such as ormat, is a very known approach, whereby an organic substance is used as working fluid instead of water. the benefit is that this process can reject heat at lower temperatures for the production of electricity than the regular water steam cycle. an example of use of the steam rankine cycle is the cyclone waste heat engine. = = = cogeneration and trigeneration = = = waste of the by - product heat is reduced if a cogeneration system is used, also known as a combined heat and power ( chp ) system. limitations to the use of by - product heat arise primarily
body temperature is called hypothermia. slight hyperthermia results in increasing hr and strength of contraction. hypothermia slows the rate and strength of heart contractions. this distinct slowing of the heart is one component of the larger diving reflex that diverts blood to essential organs while submerged. if sufficiently chilled, the heart will stop beating, a technique that may be employed during open heart surgery. in this case, the patient's blood is normally diverted to an artificial heart - lung machine to maintain the body's blood supply and gas exchange until the surgery is complete, and sinus rhythm can be restored. excessive hyperthermia and hypothermia will both result in death, as enzymes drive the body systems to cease normal function, beginning with the central nervous system. = = = = physiological control over heart rate = = = = a study shows that bottlenose dolphins can learn β apparently via instrumental conditioning β to rapidly and selectively slow down their heart rate during diving for conserving oxygen depending on external signals. in humans regulating heart rate by methods such as listening to music, meditation or a vagal maneuver takes longer and only lowers the rate to a much smaller extent. = = in different circumstances = = heart rate is not a stable value and it increases or decreases in response to the body's need in a way to maintain an equilibrium ( basal metabolic rate ) between requirement and delivery of oxygen and nutrients. the normal sa node firing rate is affected by autonomic nervous system activity : sympathetic stimulation increases and parasympathetic stimulation decreases the firing rate. = = = resting heart rate = = = normal pulse rates at rest, in beats per minute ( bpm ) : the basal or resting heart rate ( hrrest ) is defined as the heart rate when a person is awake, in a neutrally temperate environment, and has not been subject to any recent exertion or stimulation, such as stress or surprise. the normal resting heart rate is based on the at - rest firing rate of the heart's sinoatrial node, where the faster pacemaker cells driving the self - generated rhythmic firing and responsible for the heart's autorhythmicity are located. in one 1993 study, 98 % of cardiologists suggested that as a desirable target range, 50 to 90 beats per minute is more appropriate than 60 to 100. the available evidence indicates that the normal range for resting heart rate is 50 β 90 beats per minute ( bpm ). in a study of over
Answer:
|
perspire
| null |
Like humans, when some animals get hot, they do what in order to lower their body temperature
0. spend money
1. raise blood temperature
2. fly away
3. perspire
large temperature changes adapt to higher temperatures through a variety of methods. in green crabs, the process of initial warming results in an increase of oxygen consumption and heart rate, accompanied by a decrease in stroke volume and haemolymph oxygen partial pressure. as this warming continues, dissolved oxygen levels decrease below the threshold for full haemocyanin oxygen saturation. this heating then progressively releases haemocyanin - bound oxygen, saving energy in oxygen transport and resulting in an associated leveling off of metabolic rate. key to maintaining homeostasis, individual thermoregulation is the ability to maintain internal body temperature in humans, the most recognizable eurytherm. in humans, deep - body temperature is regulated by cutaneous blood flow, which maintains this temperature despite changes in the external environment. homo sapiens'ability to survive in different ambient temperatures is a key factor in the species success, and one cited reason for why homo sapiens eventually outcompeted neanderthals ( homo neanderthalensis ). humans have two major forms of thermogenesis. the first is shivering, in which a warm - blooded creature produces involuntary contraction of skeletal muscle in order to produce heat. in addition, shivering also signals the body to produce irisin, a hormone that has been shown to convert white fat to brown fat, which is used in non - shivering thermogenesis, the second type of human thermogensis. non - shivering thermogenesis occurs in the brown fat, which contains the uncoupling protein thermogenin. this protein decreases the proton gradient generated in oxidative phosphorylation during the synthesis of atp, uncoupling the electron transport in the mitochondrion from the production of chemical energy ( atp ). this creation of a gradient across the mitochondrial membrane causes energy to be lost as heat. on the other hand, humans have only one method of cooling themselves, biologically speaking : sweat evaporation. cutaneous eccrine sweat glands produce sweat, which is made up of mostly water with a small amount of ions. evaporation of this sweat helps to cool the blood beneath the skin, resulting in a cooling of deep - body temperature. while some organisms are eurythermic due to their ability to regulate internal body temperature, like humans, others have wildly different methods of extreme temperature tolerance. tardigrades are able to enter an anhydrobiotic state, often called a tun, in order to both prevent desiccation and
in its different aspects causes an animal to limit its movement ; the metabolic energy not expended in activity is diverted to the fever responses, which involves raising body temperature. this also limits an animal's exposure to predators while it is cognitively and physically impaired. = = = specific advantages = = = the individual components of sickness behavior have specific individual advantages. anorexia limits food ingestion and therefore reduces the availability of iron in the gut ( and from gut absorption ). iron may aid bacterial reproduction, so its reduction is useful during sickness. plasma concentrations of iron are lowered for this anti - bacterial reason in fever. lowered threshold for pain ensures that an animal is attentive that it does not place pressure on injured and inflamed tissues that might disrupt their healing. reduced grooming is adaptive since it reduces water loss. = = = inclusive fitness advantages = = = according to the'eyam hypothesis ', sickness behavior, by promoting immobility and social disinterest, limits the direct contacts of individuals with their relatives. by reducing eating and drinking, it limits diarrhea and defecation, reducing environmental contamination. by reducing self - grooming and changing stance, gait and vocalization, it also signals poor health to kin. all in all, sickness behavior reduces the rate of further infection, a trait that is likely propagated by kin selection. = = = social advantage = = = humans helped each other in case of sickness or injury throughout their hunter - gatherer past and afterwards. convincing others of being badly in need of relief, assistance, and care heightened the chance of survival of the sick individual. high direct costs, such as energy spent on fever and potential harm caused by high body temperatures, and high opportunity costs, as caused by inactivity, social disinterest, and lack of appetite, make sickness behavior a highly costly and therefore credible signal of need. = = immune control = = lipopolysaccharides trigger the immune system to produce proinflammatory cytokines il - 1, il - 6, and tumor necrosis factor ( tnf ). these peripherally released cytokines act on the brain via a fast transmission pathway involving primary input through the vagus nerves, and a slow transmission pathway involving cytokines originating from the choroid plexus and circumventricular organs and diffusing into the brain parenchyma by volume transmission. peripheral cytokines are capable of entering the brain directly but
a medical practitioner. = = mechanism = = sweating allows the body to regulate its temperature. sweating is controlled from a center in the preoptic and anterior regions of the brain's hypothalamus, where thermosensitive neurons are located. the heat - regulatory function of the hypothalamus is also affected by inputs from temperature receptors in the skin. high skin temperature reduces the hypothalamic set point for sweating and increases the gain of the hypothalamic feedback system in response to variations in core temperature. overall, however, the sweating response to a rise in hypothalamic ('core') temperature is much larger than the response to the same increase in average skin temperature. sweating causes a decrease in core temperature through evaporative cooling at the skin surface. as high energy molecules evaporate from the skin, releasing energy absorbed from the body, the skin and superficial vessels decrease in temperature. cooled venous blood then returns to the body's core and counteracts rising core temperatures. there are two situations in which the nerves will stimulate the sweat glands, causing perspiration : during physical heat and during emotional stress. in general, emotionally induced sweating is restricted to palms, soles, armpits, and sometimes the forehead, while physical heat - induced sweating occurs throughout the body. people have an average of two to four million sweat glands, but how much sweat is released by each gland is determined by many factors, including sex, genetics, environmental conditions, age and fitness level. two of the major contributors to sweat rate are an individual's fitness level and weight. if an individual weighs more, sweat rate is likely to increase because the body must exert more energy to function and there is more body mass to cool down. on the other hand, a fit person will start sweating earlier and more readily. as someone becomes fit, the body becomes more efficient at regulating the body's temperature and sweat glands adapt along with the body's other systems. human sweat is not pure water ; though it contains no protein, it always contains a small amount ( 0. 2 β 1 % ) of solute. when a person moves from a cold climate to a hot climate, adaptive changes occur in the sweating mechanisms of the person. this process is referred to as acclimatization : the maximum rate of sweating increases and its solute composition decreases. the volume of water lost in sweat daily is highly variable, ranging from 100 to 8, 000 millilitres
oil refining, steel making or glass making are major sources of waste heat. = = = electronics = = = although small in terms of power, the disposal of waste heat from microchips and other electronic components, represents a significant engineering challenge. this necessitates the use of fans, heatsinks, etc. to dispose of the heat. for example, data centers use electronic components that consume electricity for computing, storage and networking. the french cnrs explains a data center is like a resistor and most of the energy it consumes is transformed into heat and requires cooling systems. = = = biological = = = humans, like all animals, produce heat as a result of metabolism. in warm conditions, this heat exceeds a level required for homeostasis in warm - blooded animals, and is disposed of by various thermoregulation methods such as sweating and panting. = = disposal = = low temperature heat contains very little capacity to do work ( exergy ), so the heat is qualified as waste heat and rejected to the environment. economically most convenient is the rejection of such heat to water from a sea, lake or river. if sufficient cooling water is not available, the plant can be equipped with a cooling tower or air cooler to reject the waste heat into the atmosphere. in some cases it is possible to use waste heat, for instance in district heating systems. = = uses = = = = = conversion to electricity = = = there are many different approaches to transfer thermal energy to electricity, and the technologies to do so have existed for several decades. an established approach is by using a thermoelectric device, where a change in temperature across a semiconductor material creates a voltage through a phenomenon known as the seebeck effect. a related approach is the use of thermogalvanic cells, where a temperature difference gives rise to an electric current in an electrochemical cell. the organic rankine cycle, offered by companies such as ormat, is a very known approach, whereby an organic substance is used as working fluid instead of water. the benefit is that this process can reject heat at lower temperatures for the production of electricity than the regular water steam cycle. an example of use of the steam rankine cycle is the cyclone waste heat engine. = = = cogeneration and trigeneration = = = waste of the by - product heat is reduced if a cogeneration system is used, also known as a combined heat and power ( chp ) system. limitations to the use of by - product heat arise primarily
body temperature is called hypothermia. slight hyperthermia results in increasing hr and strength of contraction. hypothermia slows the rate and strength of heart contractions. this distinct slowing of the heart is one component of the larger diving reflex that diverts blood to essential organs while submerged. if sufficiently chilled, the heart will stop beating, a technique that may be employed during open heart surgery. in this case, the patient's blood is normally diverted to an artificial heart - lung machine to maintain the body's blood supply and gas exchange until the surgery is complete, and sinus rhythm can be restored. excessive hyperthermia and hypothermia will both result in death, as enzymes drive the body systems to cease normal function, beginning with the central nervous system. = = = = physiological control over heart rate = = = = a study shows that bottlenose dolphins can learn β apparently via instrumental conditioning β to rapidly and selectively slow down their heart rate during diving for conserving oxygen depending on external signals. in humans regulating heart rate by methods such as listening to music, meditation or a vagal maneuver takes longer and only lowers the rate to a much smaller extent. = = in different circumstances = = heart rate is not a stable value and it increases or decreases in response to the body's need in a way to maintain an equilibrium ( basal metabolic rate ) between requirement and delivery of oxygen and nutrients. the normal sa node firing rate is affected by autonomic nervous system activity : sympathetic stimulation increases and parasympathetic stimulation decreases the firing rate. = = = resting heart rate = = = normal pulse rates at rest, in beats per minute ( bpm ) : the basal or resting heart rate ( hrrest ) is defined as the heart rate when a person is awake, in a neutrally temperate environment, and has not been subject to any recent exertion or stimulation, such as stress or surprise. the normal resting heart rate is based on the at - rest firing rate of the heart's sinoatrial node, where the faster pacemaker cells driving the self - generated rhythmic firing and responsible for the heart's autorhythmicity are located. in one 1993 study, 98 % of cardiologists suggested that as a desirable target range, 50 to 90 beats per minute is more appropriate than 60 to 100. the available evidence indicates that the normal range for resting heart rate is 50 β 90 beats per minute ( bpm ). in a study of over
Answer:
|
fly away
| 0.3 |
When working with chemicals in the lab, avoid getting hurt by
0. trying to set fire to all of the chemicals
1. mixing things together without knowing what they are
2. drinking a sample of each of the chemicals
3. keeping your eyes covered
specific cases such as predicting skin sensitizers and potential for eye injuries, as well as quantitative structure β activity relationship models. sometimes, controlled human challenge studies are performed in cases where the risk for volunteers is negligible ; these are used to verify whether results from animal studies translate to humans. many types of measurements may be made in occupational toxicology. these include external measurements of exposure, the internal dose measured via tissues and bodily fluids, the " biologically effective dose " measuring the compound that has actually interacted with host biomolecules such as dna and proteins, and measuring downstream effects of mutations, cytogenetic effects, and aberrant gene expression. experimentation may focus on the operation and regulation of biotransformation processes that may detoxify or activate toxins. these processes are subject to difference between individuals, which is studied through the field of toxicogenomics. = = history = = while the health hazards of substances used in the workplace have been recognized since antiquity, the first experimental studies of hazardous substances came in the late 19th and early 20th centuries, including the work of john scott haldane on mine gases, karl bernhard lehmann on organic substances, and ernest kennaway on occupational skin cancer. biomarkers began to be used in occupational toxicology and epidemiology in the 1970s, and the 1990s showed increasing focus on molecular mechanisms such as identifying specific enzymes that interact with toxicants, and studying their variation across individuals. = = references = =
chemical safety includes all safety policies, procedures and practices designed to minimize the risk of exposure to potentially hazardous chemicals. this includes the risks of exposure to persons handling the chemicals, to the surrounding environment, and to the communities and ecosystems within that environment. manufactured chemicals, either pure or in mixtures, solutions and emulsions, are ubiquitous in modern society, at industrial, occupational and private scale. however, there are chemicals that should not mix or get in contact with others, as they can produce byproducts that may be toxic, carcinogenic, explosive etc., or can be dangerous in themselves. to avoid disasters and mishaps, maintaining safety is paramount. chemical safety refers to safety issues surrounding the use, production, transport and handling of chemicals at large or small manufacturing facilities, laboratories, non - chemical sites that use manufactured chemicals for their business, or homes during everyday activities. while there is some overlap, it is different from process safety, which is concerned with more than just hazardous chemicals ( extending for example to refined and unrefined hydrocarbons ). process safety is specific to industrial process plants, and focuses primarily on major accidents rather than both immediate and long - term effects ( such as chemical carcinogenity ). the hazardous nature of many chemicals may be increased when mixed with other chemicals, heated or handled inappropriately. in a chemically safe environment, users are able to take appropriate actions in case of accidents, although many incidents of exposure to chemical hazards occur outside controlled environments such as manufacturing plants or laboratories. it is estimated that 1. 6 million human deaths occur each year from contact with hazardous chemicals and that in 2016, 45 million disability - adjusted life - years were lost, a significant increase from 2012. = = risks and hazards = = chemicals in use in industry and research have a range of properties which cause them to be hazardous to life. these include explosiveness, flammability, toxicity, carcinogenicity and teratogenicity. corrosive substances such as strong alkalis or acids can cause chemical burning. any one chemical or mixture may exhibit several of these properties. toxic materials may be solids in powdered or finely divided form, liquids and gases. any of these materials may all be absorbed by inhalation, directly through the skin of by contact with mucous membranes in the nose or eyes. some chemicals may persist in the body for substantial periods and can continue to exhibit toxicity. examples of such materials include mercury, arsenic, dioxins, and many organic solvent
toxic units ( tu ) are used in the field of toxicology to quantify the interactions of toxicants in binary mixtures of chemicals. a toxic unit for a given compound is based on the concentration at which there is a 50 % effect ( ex. ec50 ) for a certain biological endpoint. one toxic unit is equal to the ec50 for a given endpoint for a specific biological effect over a given amount of time. toxic units allow for the comparison of the individual toxicities of a binary mixture to the combined toxicity. this allows researchers to categorize mixtures as additive, synergistic or antagonistic. synergism and antagonism are defined by mixtures that are more or less toxic than predicted by the sum of their toxic units. contaminants are frequently present as mixtures in the environment. regulatory decisions are based on mixture toxicity models that assume additivity, which can result in under or overestimation of toxic effects. refining our understanding of mixture interactions can lead to better informed environmental management and decision making. in addition, exploring mixture interactions can elucidate the mechanisms of action for specific toxicants which, in many cases, are poorly understood. = = methods = = application of toxic units requires toxicity data for the individual components of the mixture as well as specialized mixture toxicity data. evaluating the response of each individual chemical allows researchers to generate a new dosing metric, toxic units, which is standardized to the toxicity of each chemical. since the toxicity of two compounds may vary widely, 1 toxic unit of two different compounds could correspond to two very different concentrations on a per mass basis. in addition to the toxicity of the individual components, use of toxic units requires a 2x2 factorial design concentration series where the response is measured to an increase of each contaminant with the other contaminant held constant. this elaborate concentration series allows researchers to describe how the mixture components interact with each other and predict effects at untested combinations components with nonlinear regression models. = = = point estimates = = = point estimation is a technique to predict population parameters based on available sample data and can be used to relate the mass based concentration to a toxicity based metric. point estimates in toxicology are frequently response endpoints on a dose response curve. these point estimates predict at what concentration one would expect to see a given biological endpoint like 50 % mortality ( lc50 ). any toxicological endpoint ( growth inhibition, reproduction, behavior etc. ) can be used as the toxicity metric
medical attention and special treatment needed section 5 : firefighting measures 5. 1. extinguishing media 5. 2. special hazards arising from the substance or mixture 5. 3. advice for firefighters section 6 : accidental release measure 6. 1. personal precautions, protective equipment and emergency procedures 6. 2. environmental precautions 6. 3. methods and material for containment and cleaning up 6. 4. reference to other sections section 7 : handling and storage 7. 1. precautions for safe handling 7. 2. conditions for safe storage, including any incompatibilities 7. 3. specific end use ( s ) section 8 : exposure controls / personal protection 8. 1. control parameters 8. 2. exposure controls section 9 : physical and chemical properties 9. 1. information on basic physical and chemical properties 9. 2. other information section 10 : stability and reactivity 10. 1. reactivity 10. 2. chemical stability 10. 3. possibility of hazardous reactions 10. 4. conditions to avoid 10. 5. incompatible materials 10. 6. hazardous decomposition products section 11 : toxicological information 11. 1. information on toxicological effects section 12 : ecological information 12. 1. toxicity 12. 2. persistence and degradability 12. 3. bioaccumulative potential 12. 4. mobility in soil 12. 5. results of pbt and vpvb assessment 12. 6. other adverse effects section 13 : disposal considerations 13. 1. waste treatment methods section 14 : transport information 14. 1. un number 14. 2. un proper shipping name 14. 3. transport hazard class ( es ) 14. 4. packing group 14. 5. environmental hazards 14. 6. special precautions for user 14. 7. transport in bulk according to annex ii of marpol and the ibc code section 15 : regulatory information 15. 1. safety, health and environmental regulations / legislation specific for the substance or mixture 15. 2. chemical safety assessment section 16 : other information 16. 2. date of the latest revision of the sds = = national and international requirements = = = = = canada = = = in canada, the program known as the workplace hazardous materials information system ( whmis ) establishes the requirements for sdss in workplaces and is administered federally by health canada under the hazardous products act, part ii, and the controlled products regulations. = = = european union = = = safety data sheets have been made an integral part of the system of regulation ( ec ) no 1907 / 2006 ( reach ). the original requirements
amongst a wide range of other measures designed to improve the safety in the workplace in the uk. enforcement of chemical safety is the responsibility of the health and safety executive ( hse ), which implements relevant sections of the health and safety at work etc. act 1974, formulates regulations, provides safety advice and guidance and investigates major chemical incidents. = = = united states = = = in the us, the u. s. chemical safety and hazard investigation board is responsible for investigating major chemical accidents and making recommendations to mitigate such events in the future. = = risk areas = = = = = manufacturing = = = the manufacture and purification of chemicals can involve a range of reagents which may themselves be hazardous, and a range of products which equally may be hazardous. for example, in order to produce the herbicide 2, 4, 5 - trichlorophenol, chlorine, an acutely toxic gas, is reacted with phenol, a hazardous organic liquid. the output is typically a mixture of chlorinated organic compounds, only some of which is the desired product. in this example, contaminants can include 2, 3, 7, 8 - tetrachlorodibenzodioxin, a dioxin, one of the most toxic synthetic chemicals known which is both acutely and chronically toxic and teratogenic and whose use on one occasion led to the abandonment of the times beach, missouri. this reaction was also the cause of the infamous bhopal disaster, during which the highly poisonous gas methyl isocyanate was released. major chemical accidents ( and events that have the potential to escalate to major accidents ) are covered in the specialized domain of process safety. = = = laboratories = = = laboratories in schools, university, research establishments and manufacturing typically store and handle a wide range of chemicals. safety standards for such areas are high and most laboratories provide specific infrastructure to minimise risk including fume cupboards, impervious and inert work surfaces, emergency shower stations, emergency eye wash stations, and strict policies on the wearing of appropriate ppe. = = = domestic use = = = there are many hazardous chemicals in routine use in the domestic environment including cleaning agents such as bleach and caustic soda. some modern cleaning formulations also contain sodium silicate and other highly alkaline components. modern packaging into " pods " may increase the risk of misuse, particularly for small children. = = = waste disposal = = = surplus hazardous materials often reach
Answer:
|
keeping your eyes covered
| null |
When working with chemicals in the lab, avoid getting hurt by
0. trying to set fire to all of the chemicals
1. mixing things together without knowing what they are
2. drinking a sample of each of the chemicals
3. keeping your eyes covered
specific cases such as predicting skin sensitizers and potential for eye injuries, as well as quantitative structure β activity relationship models. sometimes, controlled human challenge studies are performed in cases where the risk for volunteers is negligible ; these are used to verify whether results from animal studies translate to humans. many types of measurements may be made in occupational toxicology. these include external measurements of exposure, the internal dose measured via tissues and bodily fluids, the " biologically effective dose " measuring the compound that has actually interacted with host biomolecules such as dna and proteins, and measuring downstream effects of mutations, cytogenetic effects, and aberrant gene expression. experimentation may focus on the operation and regulation of biotransformation processes that may detoxify or activate toxins. these processes are subject to difference between individuals, which is studied through the field of toxicogenomics. = = history = = while the health hazards of substances used in the workplace have been recognized since antiquity, the first experimental studies of hazardous substances came in the late 19th and early 20th centuries, including the work of john scott haldane on mine gases, karl bernhard lehmann on organic substances, and ernest kennaway on occupational skin cancer. biomarkers began to be used in occupational toxicology and epidemiology in the 1970s, and the 1990s showed increasing focus on molecular mechanisms such as identifying specific enzymes that interact with toxicants, and studying their variation across individuals. = = references = =
chemical safety includes all safety policies, procedures and practices designed to minimize the risk of exposure to potentially hazardous chemicals. this includes the risks of exposure to persons handling the chemicals, to the surrounding environment, and to the communities and ecosystems within that environment. manufactured chemicals, either pure or in mixtures, solutions and emulsions, are ubiquitous in modern society, at industrial, occupational and private scale. however, there are chemicals that should not mix or get in contact with others, as they can produce byproducts that may be toxic, carcinogenic, explosive etc., or can be dangerous in themselves. to avoid disasters and mishaps, maintaining safety is paramount. chemical safety refers to safety issues surrounding the use, production, transport and handling of chemicals at large or small manufacturing facilities, laboratories, non - chemical sites that use manufactured chemicals for their business, or homes during everyday activities. while there is some overlap, it is different from process safety, which is concerned with more than just hazardous chemicals ( extending for example to refined and unrefined hydrocarbons ). process safety is specific to industrial process plants, and focuses primarily on major accidents rather than both immediate and long - term effects ( such as chemical carcinogenity ). the hazardous nature of many chemicals may be increased when mixed with other chemicals, heated or handled inappropriately. in a chemically safe environment, users are able to take appropriate actions in case of accidents, although many incidents of exposure to chemical hazards occur outside controlled environments such as manufacturing plants or laboratories. it is estimated that 1. 6 million human deaths occur each year from contact with hazardous chemicals and that in 2016, 45 million disability - adjusted life - years were lost, a significant increase from 2012. = = risks and hazards = = chemicals in use in industry and research have a range of properties which cause them to be hazardous to life. these include explosiveness, flammability, toxicity, carcinogenicity and teratogenicity. corrosive substances such as strong alkalis or acids can cause chemical burning. any one chemical or mixture may exhibit several of these properties. toxic materials may be solids in powdered or finely divided form, liquids and gases. any of these materials may all be absorbed by inhalation, directly through the skin of by contact with mucous membranes in the nose or eyes. some chemicals may persist in the body for substantial periods and can continue to exhibit toxicity. examples of such materials include mercury, arsenic, dioxins, and many organic solvent
toxic units ( tu ) are used in the field of toxicology to quantify the interactions of toxicants in binary mixtures of chemicals. a toxic unit for a given compound is based on the concentration at which there is a 50 % effect ( ex. ec50 ) for a certain biological endpoint. one toxic unit is equal to the ec50 for a given endpoint for a specific biological effect over a given amount of time. toxic units allow for the comparison of the individual toxicities of a binary mixture to the combined toxicity. this allows researchers to categorize mixtures as additive, synergistic or antagonistic. synergism and antagonism are defined by mixtures that are more or less toxic than predicted by the sum of their toxic units. contaminants are frequently present as mixtures in the environment. regulatory decisions are based on mixture toxicity models that assume additivity, which can result in under or overestimation of toxic effects. refining our understanding of mixture interactions can lead to better informed environmental management and decision making. in addition, exploring mixture interactions can elucidate the mechanisms of action for specific toxicants which, in many cases, are poorly understood. = = methods = = application of toxic units requires toxicity data for the individual components of the mixture as well as specialized mixture toxicity data. evaluating the response of each individual chemical allows researchers to generate a new dosing metric, toxic units, which is standardized to the toxicity of each chemical. since the toxicity of two compounds may vary widely, 1 toxic unit of two different compounds could correspond to two very different concentrations on a per mass basis. in addition to the toxicity of the individual components, use of toxic units requires a 2x2 factorial design concentration series where the response is measured to an increase of each contaminant with the other contaminant held constant. this elaborate concentration series allows researchers to describe how the mixture components interact with each other and predict effects at untested combinations components with nonlinear regression models. = = = point estimates = = = point estimation is a technique to predict population parameters based on available sample data and can be used to relate the mass based concentration to a toxicity based metric. point estimates in toxicology are frequently response endpoints on a dose response curve. these point estimates predict at what concentration one would expect to see a given biological endpoint like 50 % mortality ( lc50 ). any toxicological endpoint ( growth inhibition, reproduction, behavior etc. ) can be used as the toxicity metric
medical attention and special treatment needed section 5 : firefighting measures 5. 1. extinguishing media 5. 2. special hazards arising from the substance or mixture 5. 3. advice for firefighters section 6 : accidental release measure 6. 1. personal precautions, protective equipment and emergency procedures 6. 2. environmental precautions 6. 3. methods and material for containment and cleaning up 6. 4. reference to other sections section 7 : handling and storage 7. 1. precautions for safe handling 7. 2. conditions for safe storage, including any incompatibilities 7. 3. specific end use ( s ) section 8 : exposure controls / personal protection 8. 1. control parameters 8. 2. exposure controls section 9 : physical and chemical properties 9. 1. information on basic physical and chemical properties 9. 2. other information section 10 : stability and reactivity 10. 1. reactivity 10. 2. chemical stability 10. 3. possibility of hazardous reactions 10. 4. conditions to avoid 10. 5. incompatible materials 10. 6. hazardous decomposition products section 11 : toxicological information 11. 1. information on toxicological effects section 12 : ecological information 12. 1. toxicity 12. 2. persistence and degradability 12. 3. bioaccumulative potential 12. 4. mobility in soil 12. 5. results of pbt and vpvb assessment 12. 6. other adverse effects section 13 : disposal considerations 13. 1. waste treatment methods section 14 : transport information 14. 1. un number 14. 2. un proper shipping name 14. 3. transport hazard class ( es ) 14. 4. packing group 14. 5. environmental hazards 14. 6. special precautions for user 14. 7. transport in bulk according to annex ii of marpol and the ibc code section 15 : regulatory information 15. 1. safety, health and environmental regulations / legislation specific for the substance or mixture 15. 2. chemical safety assessment section 16 : other information 16. 2. date of the latest revision of the sds = = national and international requirements = = = = = canada = = = in canada, the program known as the workplace hazardous materials information system ( whmis ) establishes the requirements for sdss in workplaces and is administered federally by health canada under the hazardous products act, part ii, and the controlled products regulations. = = = european union = = = safety data sheets have been made an integral part of the system of regulation ( ec ) no 1907 / 2006 ( reach ). the original requirements
amongst a wide range of other measures designed to improve the safety in the workplace in the uk. enforcement of chemical safety is the responsibility of the health and safety executive ( hse ), which implements relevant sections of the health and safety at work etc. act 1974, formulates regulations, provides safety advice and guidance and investigates major chemical incidents. = = = united states = = = in the us, the u. s. chemical safety and hazard investigation board is responsible for investigating major chemical accidents and making recommendations to mitigate such events in the future. = = risk areas = = = = = manufacturing = = = the manufacture and purification of chemicals can involve a range of reagents which may themselves be hazardous, and a range of products which equally may be hazardous. for example, in order to produce the herbicide 2, 4, 5 - trichlorophenol, chlorine, an acutely toxic gas, is reacted with phenol, a hazardous organic liquid. the output is typically a mixture of chlorinated organic compounds, only some of which is the desired product. in this example, contaminants can include 2, 3, 7, 8 - tetrachlorodibenzodioxin, a dioxin, one of the most toxic synthetic chemicals known which is both acutely and chronically toxic and teratogenic and whose use on one occasion led to the abandonment of the times beach, missouri. this reaction was also the cause of the infamous bhopal disaster, during which the highly poisonous gas methyl isocyanate was released. major chemical accidents ( and events that have the potential to escalate to major accidents ) are covered in the specialized domain of process safety. = = = laboratories = = = laboratories in schools, university, research establishments and manufacturing typically store and handle a wide range of chemicals. safety standards for such areas are high and most laboratories provide specific infrastructure to minimise risk including fume cupboards, impervious and inert work surfaces, emergency shower stations, emergency eye wash stations, and strict policies on the wearing of appropriate ppe. = = = domestic use = = = there are many hazardous chemicals in routine use in the domestic environment including cleaning agents such as bleach and caustic soda. some modern cleaning formulations also contain sodium silicate and other highly alkaline components. modern packaging into " pods " may increase the risk of misuse, particularly for small children. = = = waste disposal = = = surplus hazardous materials often reach
Answer:
|
mixing things together without knowing what they are
| 0.3 |
Which uses a nonrenewable resource?
0. wind chimes
1. solar-powered car
2. a B52 Bomber
3. a bicycle
##ed organic matter. abiotic : resources that originate from non - living and inorganic material. these include land, water, air, rare - earth elements, and heavy metals including ores, such as gold, iron, copper, silver, etc. = = = stage of development = = = potential resources : resources that are known to exist, but have not been utilized yet. these may be used in the future. for example, petroleum in sedimentary rocks that, until extracted and put to use, remains a potential resource. actual resources : resources that have been surveyed, quantified and qualified, and are currently used in development. these are typically dependent on technology and the level of their feasibility, wood processing for example. reserves : the part of an actual resource that can be developed profitably in the future. stocks : resources that have been surveyed, but cannot be used due to lack of technology, hydrogen vehicles for example. = = = renewability / exhaustibility = = = renewable resources : these resources can be replenished naturally. some of these resources, like solar energy, air, wind, water, etc. are continuously available and their quantities are not noticeably affected by human consumption. though many renewable resources do not have such a rapid recovery rate, these resources are susceptible to depletion by over - use. resources from a human use perspective are classified as renewable so long as the rate of replenishment / recovery exceeds that of the rate of consumption. they replenish easily compared to non - renewable resources. non - renewable resources : these resources are formed over a long geological time period in the environment and cannot be renewed easily. minerals are the most common resource included in this category. from the human perspective, resources are non - renewable when their rate of consumption exceeds the rate of replenishment / recovery ; a good example of this is fossil fuels, which are in this category because their rate of formation is extremely slow ( potentially millions of years ), meaning they are considered non - renewable. some resources naturally deplete in amount without human interference, the most notable of these being radio - active elements such as uranium, which naturally decay into heavy metals. of these, the metallic minerals can be re - used by recycling them, but coal and petroleum cannot be recycled. = = = ownership = = = individual resources : resources owned privately by individuals. these include plots, houses, plantations, pastures, ponds, etc. community resources : resources which are accessible to all the members of a community. e. g. : cemeteries
material for a good life, freedom and choice, health, good social relations, and security. wetlands - areas of permanent or intermittent inundation, whether natural or artificial, with water that is static or flowing, fresh, brackish or salt, including areas of marine water not exceeding 6 m at low tide. ( adapted from definition of the ramsar convention on wetlands of international importance ). engineered wetlands are becoming more frequent and are sometimes called constructed wetlands. in urban areas wetlands are sometimes referred to as the kidney of a city. whitegoods - household electrical appliances like refrigerators, washing machines, clothes dryers, and dishwashers. wind energy - the kinetic energy present in the motion of the wind. wind energy can be converted to mechanical or electrical energy. a traditional mechanical windmill can be used for pumping water or grinding grain. a modern electrical wind turbine converts the force of the wind to electrical energy for consumption on - site and / or export to the electricity grid. wind turbines β see wind energy. work β physical or mental effort ; a force exerted for a distance ; an energy transformation process which results in a change of concentration or form of energy. = = z = = zero waste β turning waste into resource ; the redesign of resource - use so that waste can ultimately be reduced to zero ; ensuring that by - products are used elsewhere and goods are recycled, in emulation of the cycling of wastes in nature. = = see also = = environmental science climate change acronyms glossary of climate change list of environmental issues list of sustainability topics = = references = = = = external links = = environmental terminology discovery service β eea ( multilingual environmental glossary in 28 languages : ar, bg, cs, da, de, el, en, es, et, eu, fi, fr, hu, is, it, lt, lv, mt, nl, no, pl, pt, ro, ru, sk, sl, sv, tr )
are called perpetual resources because they are available continuously, though at a limited rate. human consumption does not affect their quantity. many renewable resources can be depleted by human use, but may also be replenished, thus maintaining a flow. some of these, such as crops, take a short time for renewal ; others, such as water, take a comparatively longer time, while others, such as forests, need even longer periods. depending upon the speed and quantity of consumption, overconsumption can lead to depletion or the total and everlasting destruction of a resource. important examples are agricultural areas, fish and other animals, forests, healthy water and soil, cultivated and natural landscapes. such conditionally renewable resources are sometimes classified as a third kind of resource or as a subtype of renewable resources. conditionally renewable resources are presently subject to excess human consumption and the only sustainable long - term use of such resources is within the so - called zero ecological footprint, where humans use less than the earth's ecological capacity to regenerate. natural resources are also categorized based on distribution : ubiquitous resources are found everywhere ( for example, air, light, and water ). localized resources are found only in certain parts of the world ( for example metal ores and geothermal power ). actual vs. potential natural resources are distinguished as follows : actual resources are those resources whose location and quantity are known and we have the technology to exploit and use them. potential resources are those of which we have insufficient knowledge or do not have the technology to exploit them at present. based on ownership, resources can be classified as individual, community, national, and international. = = labour or human resources = = in economics, labor or human resources refers to the human work in the production of goods and rendering of services. human resources can be defined in terms of skills, energy, talent, abilities, or knowledge. in a project management context, human resources are those employees responsible for undertaking the activities defined in the project plan. = = capital or infrastructure = = in economics, capital goods or capital are " those durable produced goods that are in turn used as productive inputs for further production " of goods and services. a typical example is the machinery used in a factory. at the macroeconomic level, " the nation's capital stock includes buildings, equipment, software, and inventories during a given year. " capitals are the most important economic resource. = = tangible versus intangible = = whereas, tangible resources such as equipment have an actual physical existence, int
energy as was used for its production. less energy is needed if materials are recycled rather than mined. in concentrated solar power, solar rays are concentrated by a field of mirrors, heating a fluid. electricity is produced from the resulting steam with a heat engine. concentrated solar power can support dispatchable power generation, as some of the heat is typically stored to enable electricity to be generated when needed. in addition to electricity production, solar energy is used more directly ; solar thermal heating systems are used for hot water production, heating buildings, drying, and desalination. = = = = wind power = = = = wind has been an important driver of development over millennia, providing mechanical energy for industrial processes, water pumps, and sailing ships. modern wind turbines are used to generate electricity and provided approximately 6 % of global electricity in 2019. electricity from onshore wind farms is often cheaper than existing coal plants and competitive with natural gas and nuclear. wind turbines can also be placed offshore, where winds are steadier and stronger than on land but construction and maintenance costs are higher. onshore wind farms, often built in wild or rural areas, have a visual impact on the landscape. while collisions with wind turbines kill both bats and to a lesser extent birds, these impacts are lower than from other infrastructure such as windows and transmission lines. the noise and flickering light created by the turbines can cause annoyance and constrain construction near densely populated areas. wind power, in contrast to nuclear and fossil fuel plants, does not consume water. little energy is needed for wind turbine construction compared to the energy produced by the wind power plant itself. turbine blades are not fully recyclable, and research into methods of manufacturing easier - to - recycle blades is ongoing. = = = = hydropower = = = = hydroelectric plants convert the energy of moving water into electricity. in 2020, hydropower supplied 17 % of the world's electricity, down from a high of nearly 20 % in the mid - to - late 20th century. in conventional hydropower, a reservoir is created behind a dam. conventional hydropower plants provide a highly flexible, dispatchable electricity supply. they can be combined with wind and solar power to meet peaks in demand and to compensate when wind and sun are less available. compared to reservoir - based facilities, run - of - the - river hydroelectricity generally has less environmental impact. however, its ability to generate power depends on river flow, which can vary with daily and seasonal weather. reservoirs provide water quantity controls that are used for flood control and
megajoule ( mj ) of electricity produced by a hydroelectric plant is equivalent to 3 mj of oil. sunlight is a main source of primary energy, which can be transformed into plants and then into coal, oil and gas. solar power and wind power are other derivatives of sunlight. note that although coal, oil and natural gas are derived from sunlight, they are considered primary energy sources which are extracted from the earth ( fossil fuels ). natural uranium is also a primary energy source extracted from the earth but does not come from the decomposition of organisms ( mineral fuel ). = = see also = = capital goods coefficient of performance embedded energy energy and society energy crisis energy pay - back energy resource energy source energy storage energyware entropy exergy future energy development hydrogen economy iso 14000 liquid nitrogen economy lithium economy methanol economy metal energy carriers renewable resource vegetable oil economy renewable energy = = references = = = = further reading = = european nuclear society info pool / glossary : energy carrier archived september 27, 2006, at the wayback machine our energy futures glossary : energy carriers storungsdienst, elektriker ( in german ) = = external links = = " boron : a better energy carrier than hydrogen? " paper by graham cowan iso 13600 technical energy systems - - basic concepts : gives the basic concepts needed to define and describe technical energy systems.
Answer:
|
a B52 Bomber
| null |
Which uses a nonrenewable resource?
0. wind chimes
1. solar-powered car
2. a B52 Bomber
3. a bicycle
##ed organic matter. abiotic : resources that originate from non - living and inorganic material. these include land, water, air, rare - earth elements, and heavy metals including ores, such as gold, iron, copper, silver, etc. = = = stage of development = = = potential resources : resources that are known to exist, but have not been utilized yet. these may be used in the future. for example, petroleum in sedimentary rocks that, until extracted and put to use, remains a potential resource. actual resources : resources that have been surveyed, quantified and qualified, and are currently used in development. these are typically dependent on technology and the level of their feasibility, wood processing for example. reserves : the part of an actual resource that can be developed profitably in the future. stocks : resources that have been surveyed, but cannot be used due to lack of technology, hydrogen vehicles for example. = = = renewability / exhaustibility = = = renewable resources : these resources can be replenished naturally. some of these resources, like solar energy, air, wind, water, etc. are continuously available and their quantities are not noticeably affected by human consumption. though many renewable resources do not have such a rapid recovery rate, these resources are susceptible to depletion by over - use. resources from a human use perspective are classified as renewable so long as the rate of replenishment / recovery exceeds that of the rate of consumption. they replenish easily compared to non - renewable resources. non - renewable resources : these resources are formed over a long geological time period in the environment and cannot be renewed easily. minerals are the most common resource included in this category. from the human perspective, resources are non - renewable when their rate of consumption exceeds the rate of replenishment / recovery ; a good example of this is fossil fuels, which are in this category because their rate of formation is extremely slow ( potentially millions of years ), meaning they are considered non - renewable. some resources naturally deplete in amount without human interference, the most notable of these being radio - active elements such as uranium, which naturally decay into heavy metals. of these, the metallic minerals can be re - used by recycling them, but coal and petroleum cannot be recycled. = = = ownership = = = individual resources : resources owned privately by individuals. these include plots, houses, plantations, pastures, ponds, etc. community resources : resources which are accessible to all the members of a community. e. g. : cemeteries
material for a good life, freedom and choice, health, good social relations, and security. wetlands - areas of permanent or intermittent inundation, whether natural or artificial, with water that is static or flowing, fresh, brackish or salt, including areas of marine water not exceeding 6 m at low tide. ( adapted from definition of the ramsar convention on wetlands of international importance ). engineered wetlands are becoming more frequent and are sometimes called constructed wetlands. in urban areas wetlands are sometimes referred to as the kidney of a city. whitegoods - household electrical appliances like refrigerators, washing machines, clothes dryers, and dishwashers. wind energy - the kinetic energy present in the motion of the wind. wind energy can be converted to mechanical or electrical energy. a traditional mechanical windmill can be used for pumping water or grinding grain. a modern electrical wind turbine converts the force of the wind to electrical energy for consumption on - site and / or export to the electricity grid. wind turbines β see wind energy. work β physical or mental effort ; a force exerted for a distance ; an energy transformation process which results in a change of concentration or form of energy. = = z = = zero waste β turning waste into resource ; the redesign of resource - use so that waste can ultimately be reduced to zero ; ensuring that by - products are used elsewhere and goods are recycled, in emulation of the cycling of wastes in nature. = = see also = = environmental science climate change acronyms glossary of climate change list of environmental issues list of sustainability topics = = references = = = = external links = = environmental terminology discovery service β eea ( multilingual environmental glossary in 28 languages : ar, bg, cs, da, de, el, en, es, et, eu, fi, fr, hu, is, it, lt, lv, mt, nl, no, pl, pt, ro, ru, sk, sl, sv, tr )
are called perpetual resources because they are available continuously, though at a limited rate. human consumption does not affect their quantity. many renewable resources can be depleted by human use, but may also be replenished, thus maintaining a flow. some of these, such as crops, take a short time for renewal ; others, such as water, take a comparatively longer time, while others, such as forests, need even longer periods. depending upon the speed and quantity of consumption, overconsumption can lead to depletion or the total and everlasting destruction of a resource. important examples are agricultural areas, fish and other animals, forests, healthy water and soil, cultivated and natural landscapes. such conditionally renewable resources are sometimes classified as a third kind of resource or as a subtype of renewable resources. conditionally renewable resources are presently subject to excess human consumption and the only sustainable long - term use of such resources is within the so - called zero ecological footprint, where humans use less than the earth's ecological capacity to regenerate. natural resources are also categorized based on distribution : ubiquitous resources are found everywhere ( for example, air, light, and water ). localized resources are found only in certain parts of the world ( for example metal ores and geothermal power ). actual vs. potential natural resources are distinguished as follows : actual resources are those resources whose location and quantity are known and we have the technology to exploit and use them. potential resources are those of which we have insufficient knowledge or do not have the technology to exploit them at present. based on ownership, resources can be classified as individual, community, national, and international. = = labour or human resources = = in economics, labor or human resources refers to the human work in the production of goods and rendering of services. human resources can be defined in terms of skills, energy, talent, abilities, or knowledge. in a project management context, human resources are those employees responsible for undertaking the activities defined in the project plan. = = capital or infrastructure = = in economics, capital goods or capital are " those durable produced goods that are in turn used as productive inputs for further production " of goods and services. a typical example is the machinery used in a factory. at the macroeconomic level, " the nation's capital stock includes buildings, equipment, software, and inventories during a given year. " capitals are the most important economic resource. = = tangible versus intangible = = whereas, tangible resources such as equipment have an actual physical existence, int
energy as was used for its production. less energy is needed if materials are recycled rather than mined. in concentrated solar power, solar rays are concentrated by a field of mirrors, heating a fluid. electricity is produced from the resulting steam with a heat engine. concentrated solar power can support dispatchable power generation, as some of the heat is typically stored to enable electricity to be generated when needed. in addition to electricity production, solar energy is used more directly ; solar thermal heating systems are used for hot water production, heating buildings, drying, and desalination. = = = = wind power = = = = wind has been an important driver of development over millennia, providing mechanical energy for industrial processes, water pumps, and sailing ships. modern wind turbines are used to generate electricity and provided approximately 6 % of global electricity in 2019. electricity from onshore wind farms is often cheaper than existing coal plants and competitive with natural gas and nuclear. wind turbines can also be placed offshore, where winds are steadier and stronger than on land but construction and maintenance costs are higher. onshore wind farms, often built in wild or rural areas, have a visual impact on the landscape. while collisions with wind turbines kill both bats and to a lesser extent birds, these impacts are lower than from other infrastructure such as windows and transmission lines. the noise and flickering light created by the turbines can cause annoyance and constrain construction near densely populated areas. wind power, in contrast to nuclear and fossil fuel plants, does not consume water. little energy is needed for wind turbine construction compared to the energy produced by the wind power plant itself. turbine blades are not fully recyclable, and research into methods of manufacturing easier - to - recycle blades is ongoing. = = = = hydropower = = = = hydroelectric plants convert the energy of moving water into electricity. in 2020, hydropower supplied 17 % of the world's electricity, down from a high of nearly 20 % in the mid - to - late 20th century. in conventional hydropower, a reservoir is created behind a dam. conventional hydropower plants provide a highly flexible, dispatchable electricity supply. they can be combined with wind and solar power to meet peaks in demand and to compensate when wind and sun are less available. compared to reservoir - based facilities, run - of - the - river hydroelectricity generally has less environmental impact. however, its ability to generate power depends on river flow, which can vary with daily and seasonal weather. reservoirs provide water quantity controls that are used for flood control and
megajoule ( mj ) of electricity produced by a hydroelectric plant is equivalent to 3 mj of oil. sunlight is a main source of primary energy, which can be transformed into plants and then into coal, oil and gas. solar power and wind power are other derivatives of sunlight. note that although coal, oil and natural gas are derived from sunlight, they are considered primary energy sources which are extracted from the earth ( fossil fuels ). natural uranium is also a primary energy source extracted from the earth but does not come from the decomposition of organisms ( mineral fuel ). = = see also = = capital goods coefficient of performance embedded energy energy and society energy crisis energy pay - back energy resource energy source energy storage energyware entropy exergy future energy development hydrogen economy iso 14000 liquid nitrogen economy lithium economy methanol economy metal energy carriers renewable resource vegetable oil economy renewable energy = = references = = = = further reading = = european nuclear society info pool / glossary : energy carrier archived september 27, 2006, at the wayback machine our energy futures glossary : energy carriers storungsdienst, elektriker ( in german ) = = external links = = " boron : a better energy carrier than hydrogen? " paper by graham cowan iso 13600 technical energy systems - - basic concepts : gives the basic concepts needed to define and describe technical energy systems.
Answer:
|
a bicycle
| 0.3 |
Soil is an example of what type of resource for growing plants?
0. Recycled Resource
1. Natural Resource
2. Renewable Resource
3. Abundant Resource
##ed organic matter. abiotic : resources that originate from non - living and inorganic material. these include land, water, air, rare - earth elements, and heavy metals including ores, such as gold, iron, copper, silver, etc. = = = stage of development = = = potential resources : resources that are known to exist, but have not been utilized yet. these may be used in the future. for example, petroleum in sedimentary rocks that, until extracted and put to use, remains a potential resource. actual resources : resources that have been surveyed, quantified and qualified, and are currently used in development. these are typically dependent on technology and the level of their feasibility, wood processing for example. reserves : the part of an actual resource that can be developed profitably in the future. stocks : resources that have been surveyed, but cannot be used due to lack of technology, hydrogen vehicles for example. = = = renewability / exhaustibility = = = renewable resources : these resources can be replenished naturally. some of these resources, like solar energy, air, wind, water, etc. are continuously available and their quantities are not noticeably affected by human consumption. though many renewable resources do not have such a rapid recovery rate, these resources are susceptible to depletion by over - use. resources from a human use perspective are classified as renewable so long as the rate of replenishment / recovery exceeds that of the rate of consumption. they replenish easily compared to non - renewable resources. non - renewable resources : these resources are formed over a long geological time period in the environment and cannot be renewed easily. minerals are the most common resource included in this category. from the human perspective, resources are non - renewable when their rate of consumption exceeds the rate of replenishment / recovery ; a good example of this is fossil fuels, which are in this category because their rate of formation is extremely slow ( potentially millions of years ), meaning they are considered non - renewable. some resources naturally deplete in amount without human interference, the most notable of these being radio - active elements such as uranium, which naturally decay into heavy metals. of these, the metallic minerals can be re - used by recycling them, but coal and petroleum cannot be recycled. = = = ownership = = = individual resources : resources owned privately by individuals. these include plots, houses, plantations, pastures, ponds, etc. community resources : resources which are accessible to all the members of a community. e. g. : cemeteries
include means for input, processing, output, communication, and storage. = = natural = = natural resources are derived from the environment. many natural resources are essential for human survival, while others are used to satisfy human desire. conservation is the management of natural resources with the goal of sustainability. natural resources may be further classified in different ways. resources can be categorized based on origin : abiotic resources comprise non - living things ( e. g., land, water, air, and minerals such as gold, iron, copper, silver ). biotic resources are obtained from the biosphere. forests and their products, animals, birds and their products, fish and other marine organisms are important examples. minerals such as coal and petroleum are sometimes included in this category because they were formed from fossilized organic matter, over long periods. natural resources are also categorized based on the stage of development : potential resources are known to exist and may be used in the future. for example, petroleum may exist in many parts of india and kuwait that have sedimentary rocks, but until the time it is actually drilled out and put into use, it remains a potential resource. actual resources are those, that have been surveyed, their quantity and quality determined, and are being used in present times. for example, petroleum and natural gas are actively being obtained from the mumbai high fields. the development of an actual resource, such as wood processing depends on the technology available and the cost involved. that part of the actual resource that can be developed profitably with the available technology is known as a reserve resource, while that part that can not be developed profitably due to a lack of technology is known as a stock resource. natural resources can be categorized based on renewability : non - renewable resources are formed over very long geological periods. minerals and fossils are included in this category. since their formation rate is extremely slow, they cannot be replenished, once they are depleted. even though metals can be recycled and reused, whereas petroleum and gas cannot, they are still considered non - renewable resources. renewable resources, such as forests and fisheries, can be replenished or reproduced relatively quickly. the highest rate at which a resource can be used sustainably is the sustainable yield. some resources, such as sunlight, air, and wind, are called perpetual resources because they are available continuously, though at a limited rate. human consumption does not affect their quantity. many renewable resources can be depleted by human use, but may also be replenished, thus maintaining a flow. some of these
natural resources are resources that are drawn from nature and used with few modifications. this includes the sources of valued characteristics such as commercial and industrial use, aesthetic value, scientific interest, and cultural value. on earth, it includes sunlight, atmosphere, water, land, all minerals along with all vegetation, and wildlife. natural resources are part of humanity's natural heritage or protected in nature reserves. particular areas ( such as the rainforest in fatu - hiva ) often feature biodiversity and geodiversity in their ecosystems. natural resources may be classified in different ways. natural resources are materials and components ( something that can be used ) found within the environment. every man - made product is composed of natural resources ( at its fundamental level ). a natural resource may exist as a separate entity such as freshwater, air, or any living organism such as a fish, or it may be transformed by extractivist industries into an economically useful form that must be processed to obtain the resource such as metal ores, rare - earth elements, petroleum, timber and most forms of energy. some resources are renewable, which means that they can be used at a certain rate and natural processes will restore them. in contrast, many extractive industries rely heavily on non - renewable resources that can only be extracted once. natural resource allocations can be at the centre of many economic and political confrontations both within and between countries. this is particularly true during periods of increasing scarcity and shortages ( depletion and overconsumption of resources ). resource extraction is also a major source of human rights violations and environmental damage. the sustainable development goals and other international development agendas frequently focus on creating more sustainable resource extraction, with some scholars and researchers focused on creating economic models, such as circular economy, that rely less on resource extraction, and more on reuse, recycling and renewable resources that can be sustainably managed. = = classification = = there are various criteria for classifying natural resources. these include the source of origin, stages of development, renewability and ownership. = = = origin = = = biotic : resources that originate from the biosphere and have life such as flora and fauna, fisheries, livestock, etc. fossil fuels such as coal and petroleum are also included in this category because they are formed from decayed organic matter. abiotic : resources that originate from non - living and inorganic material. these include land, water, air, rare - earth elements, and heavy metals including ores, such as gold, iron, copper, silver, etc
are called perpetual resources because they are available continuously, though at a limited rate. human consumption does not affect their quantity. many renewable resources can be depleted by human use, but may also be replenished, thus maintaining a flow. some of these, such as crops, take a short time for renewal ; others, such as water, take a comparatively longer time, while others, such as forests, need even longer periods. depending upon the speed and quantity of consumption, overconsumption can lead to depletion or the total and everlasting destruction of a resource. important examples are agricultural areas, fish and other animals, forests, healthy water and soil, cultivated and natural landscapes. such conditionally renewable resources are sometimes classified as a third kind of resource or as a subtype of renewable resources. conditionally renewable resources are presently subject to excess human consumption and the only sustainable long - term use of such resources is within the so - called zero ecological footprint, where humans use less than the earth's ecological capacity to regenerate. natural resources are also categorized based on distribution : ubiquitous resources are found everywhere ( for example, air, light, and water ). localized resources are found only in certain parts of the world ( for example metal ores and geothermal power ). actual vs. potential natural resources are distinguished as follows : actual resources are those resources whose location and quantity are known and we have the technology to exploit and use them. potential resources are those of which we have insufficient knowledge or do not have the technology to exploit them at present. based on ownership, resources can be classified as individual, community, national, and international. = = labour or human resources = = in economics, labor or human resources refers to the human work in the production of goods and rendering of services. human resources can be defined in terms of skills, energy, talent, abilities, or knowledge. in a project management context, human resources are those employees responsible for undertaking the activities defined in the project plan. = = capital or infrastructure = = in economics, capital goods or capital are " those durable produced goods that are in turn used as productive inputs for further production " of goods and services. a typical example is the machinery used in a factory. at the macroeconomic level, " the nation's capital stock includes buildings, equipment, software, and inventories during a given year. " capitals are the most important economic resource. = = tangible versus intangible = = whereas, tangible resources such as equipment have an actual physical existence, int
areas raw materials can be grown on peatlands without competing with food production for land in other areas. the growing of crops extracts phosphate from the land, which is important in wetlands ; it also helps to extract other nutrients from water, making it suitable for post - water treatment purposes in many tropical countries, cultivating semi - wild native crops in peat swamp forests is a traditional livelihood which can be sustainable. restored reed beds can obstruct nitrogen and phosphorus run - off from agriculture higher up in the river system and so protect lower waters. paludiculture areas can act as habitat corridors and ecological buffer zones between traditional agriculture and intact peatlands abc = = = debates around the sustainability of paludiculture = = = the application of the term " paludiculture " is debated as it is contingent on whether different peatland agricultural practices are considered sustainable. in terms of greenhouse gas emissions, how sustainable a paludiculture practice is deemed to be depends on the greenhouse gas measured, the species of plant and the water table level of the peatland. " paludiculture " been used to refer to cultivating native and non - native crops on intact or re - wetted peatlands. in the eu's common agricultural policy, it is defined as the productive land use of wet and rewetted peatlands that preserves the peat soil and thereby minimizes co2 emissions and subsidence. a 2020 review of tropical peatland paludiculture from the national university of singapore evaluated wet and re - wetted management pathways in terms of greenhouse gas emissions and carbon sequestration and concluded that commercial paludiculture is only suited to re - wetted peatlands, where it is carbon negative or neutral, as opposed to intact peatlands, where it increases emissions. after decades of re - wetting, can still contribute to global warming to a greater extent than intact peatlands. exceptions where paludiculture on intact peatlands may be sustainable are some traditions of cultivating native crops semi - wild in intact peat swamp forest, or gathering peatland products without active cultivation. the review also suggests that, to be sustainable, paludiculture should only use native vegetation to restore peatlands whilst producing biomass, as opposed to any wetland plants which have the possibility of surviving. this is because using non - native species may create negative peatland conditions for other native plants, and non - native plants tend to have a lower yield and lifespan in undrained or re - wetted peatlands than when grown in their native habitats or drained wetlands. = = = paludiculture
Answer:
|
Renewable Resource
| null |
Soil is an example of what type of resource for growing plants?
0. Recycled Resource
1. Natural Resource
2. Renewable Resource
3. Abundant Resource
##ed organic matter. abiotic : resources that originate from non - living and inorganic material. these include land, water, air, rare - earth elements, and heavy metals including ores, such as gold, iron, copper, silver, etc. = = = stage of development = = = potential resources : resources that are known to exist, but have not been utilized yet. these may be used in the future. for example, petroleum in sedimentary rocks that, until extracted and put to use, remains a potential resource. actual resources : resources that have been surveyed, quantified and qualified, and are currently used in development. these are typically dependent on technology and the level of their feasibility, wood processing for example. reserves : the part of an actual resource that can be developed profitably in the future. stocks : resources that have been surveyed, but cannot be used due to lack of technology, hydrogen vehicles for example. = = = renewability / exhaustibility = = = renewable resources : these resources can be replenished naturally. some of these resources, like solar energy, air, wind, water, etc. are continuously available and their quantities are not noticeably affected by human consumption. though many renewable resources do not have such a rapid recovery rate, these resources are susceptible to depletion by over - use. resources from a human use perspective are classified as renewable so long as the rate of replenishment / recovery exceeds that of the rate of consumption. they replenish easily compared to non - renewable resources. non - renewable resources : these resources are formed over a long geological time period in the environment and cannot be renewed easily. minerals are the most common resource included in this category. from the human perspective, resources are non - renewable when their rate of consumption exceeds the rate of replenishment / recovery ; a good example of this is fossil fuels, which are in this category because their rate of formation is extremely slow ( potentially millions of years ), meaning they are considered non - renewable. some resources naturally deplete in amount without human interference, the most notable of these being radio - active elements such as uranium, which naturally decay into heavy metals. of these, the metallic minerals can be re - used by recycling them, but coal and petroleum cannot be recycled. = = = ownership = = = individual resources : resources owned privately by individuals. these include plots, houses, plantations, pastures, ponds, etc. community resources : resources which are accessible to all the members of a community. e. g. : cemeteries
include means for input, processing, output, communication, and storage. = = natural = = natural resources are derived from the environment. many natural resources are essential for human survival, while others are used to satisfy human desire. conservation is the management of natural resources with the goal of sustainability. natural resources may be further classified in different ways. resources can be categorized based on origin : abiotic resources comprise non - living things ( e. g., land, water, air, and minerals such as gold, iron, copper, silver ). biotic resources are obtained from the biosphere. forests and their products, animals, birds and their products, fish and other marine organisms are important examples. minerals such as coal and petroleum are sometimes included in this category because they were formed from fossilized organic matter, over long periods. natural resources are also categorized based on the stage of development : potential resources are known to exist and may be used in the future. for example, petroleum may exist in many parts of india and kuwait that have sedimentary rocks, but until the time it is actually drilled out and put into use, it remains a potential resource. actual resources are those, that have been surveyed, their quantity and quality determined, and are being used in present times. for example, petroleum and natural gas are actively being obtained from the mumbai high fields. the development of an actual resource, such as wood processing depends on the technology available and the cost involved. that part of the actual resource that can be developed profitably with the available technology is known as a reserve resource, while that part that can not be developed profitably due to a lack of technology is known as a stock resource. natural resources can be categorized based on renewability : non - renewable resources are formed over very long geological periods. minerals and fossils are included in this category. since their formation rate is extremely slow, they cannot be replenished, once they are depleted. even though metals can be recycled and reused, whereas petroleum and gas cannot, they are still considered non - renewable resources. renewable resources, such as forests and fisheries, can be replenished or reproduced relatively quickly. the highest rate at which a resource can be used sustainably is the sustainable yield. some resources, such as sunlight, air, and wind, are called perpetual resources because they are available continuously, though at a limited rate. human consumption does not affect their quantity. many renewable resources can be depleted by human use, but may also be replenished, thus maintaining a flow. some of these
natural resources are resources that are drawn from nature and used with few modifications. this includes the sources of valued characteristics such as commercial and industrial use, aesthetic value, scientific interest, and cultural value. on earth, it includes sunlight, atmosphere, water, land, all minerals along with all vegetation, and wildlife. natural resources are part of humanity's natural heritage or protected in nature reserves. particular areas ( such as the rainforest in fatu - hiva ) often feature biodiversity and geodiversity in their ecosystems. natural resources may be classified in different ways. natural resources are materials and components ( something that can be used ) found within the environment. every man - made product is composed of natural resources ( at its fundamental level ). a natural resource may exist as a separate entity such as freshwater, air, or any living organism such as a fish, or it may be transformed by extractivist industries into an economically useful form that must be processed to obtain the resource such as metal ores, rare - earth elements, petroleum, timber and most forms of energy. some resources are renewable, which means that they can be used at a certain rate and natural processes will restore them. in contrast, many extractive industries rely heavily on non - renewable resources that can only be extracted once. natural resource allocations can be at the centre of many economic and political confrontations both within and between countries. this is particularly true during periods of increasing scarcity and shortages ( depletion and overconsumption of resources ). resource extraction is also a major source of human rights violations and environmental damage. the sustainable development goals and other international development agendas frequently focus on creating more sustainable resource extraction, with some scholars and researchers focused on creating economic models, such as circular economy, that rely less on resource extraction, and more on reuse, recycling and renewable resources that can be sustainably managed. = = classification = = there are various criteria for classifying natural resources. these include the source of origin, stages of development, renewability and ownership. = = = origin = = = biotic : resources that originate from the biosphere and have life such as flora and fauna, fisheries, livestock, etc. fossil fuels such as coal and petroleum are also included in this category because they are formed from decayed organic matter. abiotic : resources that originate from non - living and inorganic material. these include land, water, air, rare - earth elements, and heavy metals including ores, such as gold, iron, copper, silver, etc
are called perpetual resources because they are available continuously, though at a limited rate. human consumption does not affect their quantity. many renewable resources can be depleted by human use, but may also be replenished, thus maintaining a flow. some of these, such as crops, take a short time for renewal ; others, such as water, take a comparatively longer time, while others, such as forests, need even longer periods. depending upon the speed and quantity of consumption, overconsumption can lead to depletion or the total and everlasting destruction of a resource. important examples are agricultural areas, fish and other animals, forests, healthy water and soil, cultivated and natural landscapes. such conditionally renewable resources are sometimes classified as a third kind of resource or as a subtype of renewable resources. conditionally renewable resources are presently subject to excess human consumption and the only sustainable long - term use of such resources is within the so - called zero ecological footprint, where humans use less than the earth's ecological capacity to regenerate. natural resources are also categorized based on distribution : ubiquitous resources are found everywhere ( for example, air, light, and water ). localized resources are found only in certain parts of the world ( for example metal ores and geothermal power ). actual vs. potential natural resources are distinguished as follows : actual resources are those resources whose location and quantity are known and we have the technology to exploit and use them. potential resources are those of which we have insufficient knowledge or do not have the technology to exploit them at present. based on ownership, resources can be classified as individual, community, national, and international. = = labour or human resources = = in economics, labor or human resources refers to the human work in the production of goods and rendering of services. human resources can be defined in terms of skills, energy, talent, abilities, or knowledge. in a project management context, human resources are those employees responsible for undertaking the activities defined in the project plan. = = capital or infrastructure = = in economics, capital goods or capital are " those durable produced goods that are in turn used as productive inputs for further production " of goods and services. a typical example is the machinery used in a factory. at the macroeconomic level, " the nation's capital stock includes buildings, equipment, software, and inventories during a given year. " capitals are the most important economic resource. = = tangible versus intangible = = whereas, tangible resources such as equipment have an actual physical existence, int
areas raw materials can be grown on peatlands without competing with food production for land in other areas. the growing of crops extracts phosphate from the land, which is important in wetlands ; it also helps to extract other nutrients from water, making it suitable for post - water treatment purposes in many tropical countries, cultivating semi - wild native crops in peat swamp forests is a traditional livelihood which can be sustainable. restored reed beds can obstruct nitrogen and phosphorus run - off from agriculture higher up in the river system and so protect lower waters. paludiculture areas can act as habitat corridors and ecological buffer zones between traditional agriculture and intact peatlands abc = = = debates around the sustainability of paludiculture = = = the application of the term " paludiculture " is debated as it is contingent on whether different peatland agricultural practices are considered sustainable. in terms of greenhouse gas emissions, how sustainable a paludiculture practice is deemed to be depends on the greenhouse gas measured, the species of plant and the water table level of the peatland. " paludiculture " been used to refer to cultivating native and non - native crops on intact or re - wetted peatlands. in the eu's common agricultural policy, it is defined as the productive land use of wet and rewetted peatlands that preserves the peat soil and thereby minimizes co2 emissions and subsidence. a 2020 review of tropical peatland paludiculture from the national university of singapore evaluated wet and re - wetted management pathways in terms of greenhouse gas emissions and carbon sequestration and concluded that commercial paludiculture is only suited to re - wetted peatlands, where it is carbon negative or neutral, as opposed to intact peatlands, where it increases emissions. after decades of re - wetting, can still contribute to global warming to a greater extent than intact peatlands. exceptions where paludiculture on intact peatlands may be sustainable are some traditions of cultivating native crops semi - wild in intact peat swamp forest, or gathering peatland products without active cultivation. the review also suggests that, to be sustainable, paludiculture should only use native vegetation to restore peatlands whilst producing biomass, as opposed to any wetland plants which have the possibility of surviving. this is because using non - native species may create negative peatland conditions for other native plants, and non - native plants tend to have a lower yield and lifespan in undrained or re - wetted peatlands than when grown in their native habitats or drained wetlands. = = = paludiculture
Answer:
|
Recycled Resource
| 0.3 |
Which is least likely to need to take in air?
0. a cat
1. a canary
2. a bear
3. a zooplankton
includes the cats, dogs, and bears ), 177 are solitary ; and 35 of the 37 wild cats are solitary, including the cougar and cheetah. however, the solitary cougar does allow other cougars to share in a kill, and the coyote can be either solitary or social. other solitary predators include the northern pike, wolf spiders and all the thousands of species of solitary wasps among arthropods, and many microorganisms and zooplankton. = = specialization = = = = = physical adaptations = = = under the pressure of natural selection, predators have evolved a variety of physical adaptations for detecting, catching, killing, and digesting prey. these include speed, agility, stealth, sharp senses, claws, teeth, filters, and suitable digestive systems. for detecting prey, predators have well - developed vision, smell, or hearing. predators as diverse as owls and jumping spiders have forward - facing eyes, providing accurate binocular vision over a relatively narrow field of view, whereas prey animals often have less acute all - round vision. animals such as foxes can smell their prey even when it is concealed under 2 feet ( 60 cm ) of snow or earth. many predators have acute hearing, and some such as echolocating bats hunt exclusively by active or passive use of sound. predators including big cats, birds of prey, and ants share powerful jaws, sharp teeth, or claws which they use to seize and kill their prey. some predators such as snakes and fish - eating birds like herons and cormorants swallow their prey whole ; some snakes can unhinge their jaws to allow them to swallow large prey, while fish - eating birds have long spear - like beaks that they use to stab and grip fast - moving and slippery prey. fish and other predators have developed the ability to crush or open the armoured shells of molluscs. many predators are powerfully built and can catch and kill animals larger than themselves ; this applies as much to small predators such as ants and shrews as to big and visibly muscular carnivores like the cougar and lion. = = = diet and behaviour = = = predators are often highly specialized in their diet and hunting behaviour ; for example, the eurasian lynx only hunts small ungulates. others such as leopards are more opportunistic generalists, preying on at least 100 species. the specialists may be highly adapted to capturing their preferred prey, whereas generalists may be better able to switch to other prey when
##gulates. others such as leopards are more opportunistic generalists, preying on at least 100 species. the specialists may be highly adapted to capturing their preferred prey, whereas generalists may be better able to switch to other prey when a preferred target is scarce. when prey have a clumped ( uneven ) distribution, the optimal strategy for the predator is predicted to be more specialized as the prey are more conspicuous and can be found more quickly ; this appears to be correct for predators of immobile prey, but is doubtful with mobile prey. in size - selective predation, predators select prey of a certain size. large prey may prove troublesome for a predator, while small prey might prove hard to find and in any case provide less of a reward. this has led to a correlation between the size of predators and their prey. size may also act as a refuge for large prey. for example, adult elephants are relatively safe from predation by lions, but juveniles are vulnerable. = = = camouflage and mimicry = = = members of the cat family such as the snow leopard ( treeless highlands ), tiger ( grassy plains, reed swamps ), ocelot ( forest ), fishing cat ( waterside thickets ), and lion ( open plains ) are camouflaged with coloration and disruptive patterns suiting their habitats. in aggressive mimicry, certain predators, including insects and fishes, make use of coloration and behaviour to attract prey. female photuris fireflies, for example, copy the light signals of other species, thereby attracting male fireflies, which they capture and eat. flower mantises are ambush predators ; camouflaged as flowers, such as orchids, they attract prey and seize it when it is close enough. frogfishes are extremely well camouflaged, and actively lure their prey to approach using an esca, a bait on the end of a rod - like appendage on the head, which they wave gently to mimic a small animal, gulping the prey in an extremely rapid movement when it is within range. = = = venom = = = many smaller predators such as the box jellyfish use venom to subdue their prey, and venom can also aid in digestion ( as is the case for rattlesnakes and some spiders ). the marbled sea snake that has adapted to egg predation has atrophied venom glands, and the gene for its three finger toxin contains a mutation ( the deletion of two nucleotides ) that inactives it
of daphnia hyaline when sampling in and out of foamlines in south wales lake, with greater number appearing in divergent zone. such distribution of particles and animals can be described using mathematical model developed by stommel that suggested area of retention on upwelling zone for sinking particles and on downwelling zone for positively buoyant particles. actually, the zooplankton could become trapped in upwelling zones to a point where animals are stimulated to swim downwards. a more detailed model was later developed by stavn describing the zooplankton aggregation where the animal orientation, dorsal light reaction and current velocity determined their region of concentration in either downwelling ( due to slow current ), upwelling ( due to high current ) and in between latter two zones ( due to intermediate currents ). there has been further improvement in such models like the modification of stommel's model by titman & kilham in order to consider the difference in maximum downwelling and upwelling velocities and by evans & taylor that discussed the instability of stommel's regions due to varying swimming speed with depth which produced spiral trajectories affecting accumulation region. nevertheless, high concentration of planktonic organisms within lc can attract birds and fish. schools of white bass roccus chrysops were observed feeding upon daphnia along the foam track. in contrast, lesser flamingoes phoeniconaias minor were observed feeding on bubble lines containing concentrated blue - green algae. similarly, medusae were found to aggregate in linear pattern ( average spacing of 129 m ) parallel with wind in the bering sea which could be due to large lcs. such aggregation can affect the feeding and predation of medusae. = = = effect on surface tension = = = high concentration of surfactants ( surface - active substances ) produced by phytoplanktons can result higher marangoni stress in converging regions in lc. numerical simulation suggest that such marangoni stress due to surfactant can increase the size of vortical structures, vertical velocity and remixing of water and biological / chemical components in the local region compared to that without surfactant. finally, more theoretical and experimental investigations are needed to confirm the significance of lc. = = references = = = = external links = = media related to langmuir circulation at wikimedia commons
the mountain lion eats both bobcats and rabbits. animals can also eat each other ; the bullfrog eats crayfish and crayfish eat young bullfrogs. the feeding habits of a juvenile animal, and, as a consequence, its trophic level, can change as it grows up. the fisheries scientist daniel pauly sets the values of trophic levels to one in plants and detritus, two in herbivores and detritivores ( primary consumers ), three in secondary consumers, and so on. the definition of the trophic level, tl, for any consumer species is : t l i = 1 + j ( t l j β
d c i j ) { \ displaystyle tl _ { i } = 1 + \ sum _ { j } ( tl _ { j } \ cdot dc _ { ij } ) \! } where t l j { \ displaystyle tl _ { j } } is the fractional trophic level of the prey j, and d c i j { \ displaystyle dc _ { ij } } represents the fraction of j in the diet of i. that is, the consumer trophic level is one plus the weighted average of how much different trophic levels contribute to its food. in the case of marine ecosystems, the trophic level of most fish and other marine consumers takes a value between 2. 0 and 5. 0. the upper value, 5. 0, is unusual, even for large fish, though it occurs in apex predators of marine mammals, such as polar bears and orcas. in addition to observational studies of animal behavior, and quantification of animal stomach contents, trophic level can be quantified through stable isotope analysis of animal tissues such as muscle, skin, hair, bone collagen. this is because there is a consistent increase in the nitrogen isotopic composition at each trophic level caused by fractionations that occur with the synthesis of biomolecules ; the magnitude of this increase in nitrogen isotopic composition is approximately 3 β 4 β°. = = mean trophic level = = in fisheries, the mean trophic level for the fisheries catch across an entire area or ecosystem is calculated for year y as : t l y = i ( t l i β
y i y ) i y i y { \ displaystyle tl _ { y } = { \ frac { \ sum _ { i
; keeton, wt ( 1977 ). " detection of atmospheric infrasound by pigeons ". nature. 265 ( 5596 ) : 725 β 726. bibcode : 1977natur. 265.. 725y. doi : 10. 1038 / 265725a0. pmid 859577. s2cid 4247969.
Answer:
|
a zooplankton
| null |
Which is least likely to need to take in air?
0. a cat
1. a canary
2. a bear
3. a zooplankton
includes the cats, dogs, and bears ), 177 are solitary ; and 35 of the 37 wild cats are solitary, including the cougar and cheetah. however, the solitary cougar does allow other cougars to share in a kill, and the coyote can be either solitary or social. other solitary predators include the northern pike, wolf spiders and all the thousands of species of solitary wasps among arthropods, and many microorganisms and zooplankton. = = specialization = = = = = physical adaptations = = = under the pressure of natural selection, predators have evolved a variety of physical adaptations for detecting, catching, killing, and digesting prey. these include speed, agility, stealth, sharp senses, claws, teeth, filters, and suitable digestive systems. for detecting prey, predators have well - developed vision, smell, or hearing. predators as diverse as owls and jumping spiders have forward - facing eyes, providing accurate binocular vision over a relatively narrow field of view, whereas prey animals often have less acute all - round vision. animals such as foxes can smell their prey even when it is concealed under 2 feet ( 60 cm ) of snow or earth. many predators have acute hearing, and some such as echolocating bats hunt exclusively by active or passive use of sound. predators including big cats, birds of prey, and ants share powerful jaws, sharp teeth, or claws which they use to seize and kill their prey. some predators such as snakes and fish - eating birds like herons and cormorants swallow their prey whole ; some snakes can unhinge their jaws to allow them to swallow large prey, while fish - eating birds have long spear - like beaks that they use to stab and grip fast - moving and slippery prey. fish and other predators have developed the ability to crush or open the armoured shells of molluscs. many predators are powerfully built and can catch and kill animals larger than themselves ; this applies as much to small predators such as ants and shrews as to big and visibly muscular carnivores like the cougar and lion. = = = diet and behaviour = = = predators are often highly specialized in their diet and hunting behaviour ; for example, the eurasian lynx only hunts small ungulates. others such as leopards are more opportunistic generalists, preying on at least 100 species. the specialists may be highly adapted to capturing their preferred prey, whereas generalists may be better able to switch to other prey when
##gulates. others such as leopards are more opportunistic generalists, preying on at least 100 species. the specialists may be highly adapted to capturing their preferred prey, whereas generalists may be better able to switch to other prey when a preferred target is scarce. when prey have a clumped ( uneven ) distribution, the optimal strategy for the predator is predicted to be more specialized as the prey are more conspicuous and can be found more quickly ; this appears to be correct for predators of immobile prey, but is doubtful with mobile prey. in size - selective predation, predators select prey of a certain size. large prey may prove troublesome for a predator, while small prey might prove hard to find and in any case provide less of a reward. this has led to a correlation between the size of predators and their prey. size may also act as a refuge for large prey. for example, adult elephants are relatively safe from predation by lions, but juveniles are vulnerable. = = = camouflage and mimicry = = = members of the cat family such as the snow leopard ( treeless highlands ), tiger ( grassy plains, reed swamps ), ocelot ( forest ), fishing cat ( waterside thickets ), and lion ( open plains ) are camouflaged with coloration and disruptive patterns suiting their habitats. in aggressive mimicry, certain predators, including insects and fishes, make use of coloration and behaviour to attract prey. female photuris fireflies, for example, copy the light signals of other species, thereby attracting male fireflies, which they capture and eat. flower mantises are ambush predators ; camouflaged as flowers, such as orchids, they attract prey and seize it when it is close enough. frogfishes are extremely well camouflaged, and actively lure their prey to approach using an esca, a bait on the end of a rod - like appendage on the head, which they wave gently to mimic a small animal, gulping the prey in an extremely rapid movement when it is within range. = = = venom = = = many smaller predators such as the box jellyfish use venom to subdue their prey, and venom can also aid in digestion ( as is the case for rattlesnakes and some spiders ). the marbled sea snake that has adapted to egg predation has atrophied venom glands, and the gene for its three finger toxin contains a mutation ( the deletion of two nucleotides ) that inactives it
of daphnia hyaline when sampling in and out of foamlines in south wales lake, with greater number appearing in divergent zone. such distribution of particles and animals can be described using mathematical model developed by stommel that suggested area of retention on upwelling zone for sinking particles and on downwelling zone for positively buoyant particles. actually, the zooplankton could become trapped in upwelling zones to a point where animals are stimulated to swim downwards. a more detailed model was later developed by stavn describing the zooplankton aggregation where the animal orientation, dorsal light reaction and current velocity determined their region of concentration in either downwelling ( due to slow current ), upwelling ( due to high current ) and in between latter two zones ( due to intermediate currents ). there has been further improvement in such models like the modification of stommel's model by titman & kilham in order to consider the difference in maximum downwelling and upwelling velocities and by evans & taylor that discussed the instability of stommel's regions due to varying swimming speed with depth which produced spiral trajectories affecting accumulation region. nevertheless, high concentration of planktonic organisms within lc can attract birds and fish. schools of white bass roccus chrysops were observed feeding upon daphnia along the foam track. in contrast, lesser flamingoes phoeniconaias minor were observed feeding on bubble lines containing concentrated blue - green algae. similarly, medusae were found to aggregate in linear pattern ( average spacing of 129 m ) parallel with wind in the bering sea which could be due to large lcs. such aggregation can affect the feeding and predation of medusae. = = = effect on surface tension = = = high concentration of surfactants ( surface - active substances ) produced by phytoplanktons can result higher marangoni stress in converging regions in lc. numerical simulation suggest that such marangoni stress due to surfactant can increase the size of vortical structures, vertical velocity and remixing of water and biological / chemical components in the local region compared to that without surfactant. finally, more theoretical and experimental investigations are needed to confirm the significance of lc. = = references = = = = external links = = media related to langmuir circulation at wikimedia commons
the mountain lion eats both bobcats and rabbits. animals can also eat each other ; the bullfrog eats crayfish and crayfish eat young bullfrogs. the feeding habits of a juvenile animal, and, as a consequence, its trophic level, can change as it grows up. the fisheries scientist daniel pauly sets the values of trophic levels to one in plants and detritus, two in herbivores and detritivores ( primary consumers ), three in secondary consumers, and so on. the definition of the trophic level, tl, for any consumer species is : t l i = 1 + j ( t l j β
d c i j ) { \ displaystyle tl _ { i } = 1 + \ sum _ { j } ( tl _ { j } \ cdot dc _ { ij } ) \! } where t l j { \ displaystyle tl _ { j } } is the fractional trophic level of the prey j, and d c i j { \ displaystyle dc _ { ij } } represents the fraction of j in the diet of i. that is, the consumer trophic level is one plus the weighted average of how much different trophic levels contribute to its food. in the case of marine ecosystems, the trophic level of most fish and other marine consumers takes a value between 2. 0 and 5. 0. the upper value, 5. 0, is unusual, even for large fish, though it occurs in apex predators of marine mammals, such as polar bears and orcas. in addition to observational studies of animal behavior, and quantification of animal stomach contents, trophic level can be quantified through stable isotope analysis of animal tissues such as muscle, skin, hair, bone collagen. this is because there is a consistent increase in the nitrogen isotopic composition at each trophic level caused by fractionations that occur with the synthesis of biomolecules ; the magnitude of this increase in nitrogen isotopic composition is approximately 3 β 4 β°. = = mean trophic level = = in fisheries, the mean trophic level for the fisheries catch across an entire area or ecosystem is calculated for year y as : t l y = i ( t l i β
y i y ) i y i y { \ displaystyle tl _ { y } = { \ frac { \ sum _ { i
; keeton, wt ( 1977 ). " detection of atmospheric infrasound by pigeons ". nature. 265 ( 5596 ) : 725 β 726. bibcode : 1977natur. 265.. 725y. doi : 10. 1038 / 265725a0. pmid 859577. s2cid 4247969.
Answer:
|
a bear
| 0.3 |
If I want to avoid too much ultraviolet rays I can
0. wear a bikini
1. wear shorts
2. wear nothing
3. wear thick socks
created mismatch between skin color and environment for many individuals. vitamin d deficiencies and uvr overexposure are concerns for many. it is important for these people individually to adjust their diet and lifestyle according to their skin color, the environment they live in, and the time of year. for practical purposes, such as exposure time for sun tanning, six skin types are distinguished following fitzpatrick ( 1975 ), listed in order of decreasing lightness : = = = fitzpatrick scale = = = the following list shows the six categories of the fitzpatrick scale in relation to the 36 categories of the older von luschan scale : dark skin with large concentrations of melanin protects against ultraviolet light and skin cancers ; light - skinned people have about a tenfold greater risk of dying from skin cancer, compared with dark - skinned persons, under equal sunlight exposure. furthermore, uv - a rays from sunlight are believed to interact with folic acid in ways that may damage health. in a number of traditional societies the sun was avoided as much as possible, especially around noon when the ultraviolet radiation in sunlight is at its most intense. midday was a time when people stayed in the shade and had the main meal followed by a nap, a practice similar to the modern siesta. = = geographic variation = = approximately 10 % of the variance in skin color occurs within regions, and approximately 90 % occurs between regions. because skin color has been under strong selective pressure, similar skin colors can result from convergent adaptation rather than from genetic relatedness ; populations with similar pigmentation may be genetically no more similar than other widely separated groups. furthermore, in some parts of the world where people from different regions have mixed extensively, the connection between skin color and ancestry has substantially weakened. in brazil, for example, skin color is not closely associated with the percentage of recent african ancestors a person has, as estimated from an analysis of genetic variants differing in frequency among continent groups. in general, people living close to the equator are highly darkly pigmented, and those living near the poles are generally very lightly pigmented. the rest of humanity shows a high degree of skin color variation between these two extremes, generally correlating with uv exposure. the main exception to this rule is in the new world, where people have only lived for about 10, 000 to 15, 000 years and show a less pronounced degree of skin pigmentation. in recent times, humans have become increasingly mobile as a consequence of improved technology, domestication, environmental change, strong curiosity, and risk - taking.
skin tones, solar lentigenes emerge as small - to medium - sized brown patches of freckling that can grow and accumulate over time on areas of the body that receive the most unprotected sun exposure, such as the back of the hands, forearms, chest, and face. for those with darker skin colors, these discolorations can appear as patches or areas of ashen - gray skin. = = exposure to the sun = = melanin in the skin protects the body by absorbing solar radiation. in general, the more melanin there is in the skin the more solar radiation can be absorbed. excessive solar radiation causes direct and indirect dna damage to the skin and the body naturally combats and seeks to repair the damage and protect the skin by creating and releasing further melanin into the skin's cells. with the production of the melanin, the skin color darkens, but can also cause sunburn. the tanning process can also be created by artificial uv radiation. there are two different mechanisms involved. firstly, the uva - radiation creates oxidative stress, which in turn oxidizes existing melanin and leads to rapid darkening of the melanin, also known as ipd ( immediate pigment darkening ). secondly, there is an increase in production of melanin known as melanogenesis. melanogenesis leads to delayed tanning and first becomes visible about 72 hours after exposure. the tan that is created by an increased melanogenesis lasts much longer than the one that is caused by oxidation of existing melanin. tanning involves not just the increased melanin production in response to uv radiation but the thickening of the top layer of the epidermis, the stratum corneum. a person's natural skin color affects their reaction to exposure to the sun. generally, those who start out with darker skin color and more melanin have better abilities to tan. individuals with very light skin and albinos have no ability to tan. the biggest differences resulting from sun exposure are visible in individuals who start out with moderately pigmented brown skin : the change is dramatically visible as tan lines, where parts of the skin which tanned are delineated from unexposed skin. modern lifestyles and mobility have created mismatch between skin color and environment for many individuals. vitamin d deficiencies and uvr overexposure are concerns for many. it is important for these people individually to adjust their diet and lifestyle according to their skin color, the environment
effect of solar protection ( sunscreen only ) in preventing the development of basal - cell carcinoma or cutaneous squamous cell carcinoma found that there was insufficient evidence to demonstrate whether sunscreen was effective for the prevention of either of these keratinocyte - derived cancers. the review did ultimately state that the certainty of these results was low, so future evidence could very well alter this conclusion. one - third occur in non - sun - exposed areas ; thus, the pathogenesis is more complex than uv exposure as the cause. the use of a chemotherapeutic agent such as 5 - fluorouracil or imiquimod can prevent the development of skin cancer. it is usually recommended to individuals with extensive sun damage, a history of multiple skin cancers, or rudimentary forms of cancer ( i. e., solar keratosis ). it is often repeated every 2 to 3 years to further decrease the risk of skin cancer. = = treatment = = the following methods are employed in the treatment of basal - cell carcinoma ( bcc ) : = = = standard surgical excision = = = surgery to remove the basal - cell carcinoma affected area and the surrounding skin is thought to be the most effective treatment. a disadvantage with standard surgical excision is a reported higher recurrence rate of basal - cell cancers of the face, especially around the eyelids, nose, and facial structures. there is no clear approach, nor clear research comparing the effectiveness of mohs micrographic surgery versus surgical excision for bcc of the eye. for basal cell carcinoma excisions on the lower lip, the wound can be covered with a keystone flap. a keystone flap is achieved by creating a flap below the defect and pulling it superiorly to cover the wound. this can be performed if there is enough skin laxity to cover the defect and adequate blood supply to the flap. = = = mohs surgery = = = for many new ( primary ) and all recurrent forms of basal cell carcinoma after previous surgery, especially on the head, neck, hands, feet, genitalia, and anterior legs ( shins ), mohs surgery should be considered. mohs surgery ( or mohs micrographic surgery ) is an outpatient procedure, developed by frederic e. mohs in the 1930s, in which the tumor is surgically excised and then immediately examined under a microscope. it is a form of pathology processing called ccpdma, which means
goggles, safety gloves, and in some cases respirators, although the greater potential penetration through clothing and mobility in air of nanoparticles should be taken into account. : 48 β 63 = = see also = = health and safety hazards of nanomaterials radiation protection = = references = =
##lorine or chloramines may also be capable of chlorinating organic material in the natural aquatic environment. further, because residual chlorine is toxic to aquatic species, the treated effluent must also be chemically dechlorinated, adding to the complexity and cost of treatment. ultraviolet ( uv ) light can be used instead of chlorine, iodine, or other chemicals. because no chemicals are used, the treated water has no adverse effect on organisms that later consume it, as may be the case with other methods. uv radiation causes damage to the genetic structure of bacteria, viruses, and other pathogens, making them incapable of reproduction. the key disadvantages of uv disinfection are the need for frequent lamp maintenance and replacement and the need for a highly treated effluent to ensure that the target microorganisms are not shielded from the uv radiation ( i. e., any solids present in the treated effluent may protect microorganisms from the uv light ). in many countries, uv light is becoming the most common means of disinfection because of the concerns about the impacts of chlorine in chlorinating residual organics in the treated sewage and in chlorinating organics in the receiving water. as with uv treatment, heat sterilization also does not add chemicals to the water being treated. however, unlike uv, heat can penetrate liquids that are not transparent. heat disinfection can also penetrate solid materials within wastewater, sterilizing their contents. thermal effluent decontamination systems provide low resource, low maintenance effluent decontamination once installed. ozone ( o3 ) is generated by passing oxygen ( o2 ) through a high voltage potential resulting in a third oxygen atom becoming attached and forming o3. ozone is very unstable and reactive and oxidizes most organic material it comes in contact with, thereby destroying many pathogenic microorganisms. ozone is considered to be safer than chlorine because, unlike chlorine which has to be stored on site ( highly poisonous in the event of an accidental release ), ozone is generated on - site as needed from the oxygen in the ambient air. ozonation also produces fewer disinfection by - products than chlorination. a disadvantage of ozone disinfection is the high cost of the ozone generation equipment and the requirements for special operators. ozone sewage treatment requires the use of an ozone generator, which decontaminates the water
Answer:
|
wear thick socks
| null |
If I want to avoid too much ultraviolet rays I can
0. wear a bikini
1. wear shorts
2. wear nothing
3. wear thick socks
created mismatch between skin color and environment for many individuals. vitamin d deficiencies and uvr overexposure are concerns for many. it is important for these people individually to adjust their diet and lifestyle according to their skin color, the environment they live in, and the time of year. for practical purposes, such as exposure time for sun tanning, six skin types are distinguished following fitzpatrick ( 1975 ), listed in order of decreasing lightness : = = = fitzpatrick scale = = = the following list shows the six categories of the fitzpatrick scale in relation to the 36 categories of the older von luschan scale : dark skin with large concentrations of melanin protects against ultraviolet light and skin cancers ; light - skinned people have about a tenfold greater risk of dying from skin cancer, compared with dark - skinned persons, under equal sunlight exposure. furthermore, uv - a rays from sunlight are believed to interact with folic acid in ways that may damage health. in a number of traditional societies the sun was avoided as much as possible, especially around noon when the ultraviolet radiation in sunlight is at its most intense. midday was a time when people stayed in the shade and had the main meal followed by a nap, a practice similar to the modern siesta. = = geographic variation = = approximately 10 % of the variance in skin color occurs within regions, and approximately 90 % occurs between regions. because skin color has been under strong selective pressure, similar skin colors can result from convergent adaptation rather than from genetic relatedness ; populations with similar pigmentation may be genetically no more similar than other widely separated groups. furthermore, in some parts of the world where people from different regions have mixed extensively, the connection between skin color and ancestry has substantially weakened. in brazil, for example, skin color is not closely associated with the percentage of recent african ancestors a person has, as estimated from an analysis of genetic variants differing in frequency among continent groups. in general, people living close to the equator are highly darkly pigmented, and those living near the poles are generally very lightly pigmented. the rest of humanity shows a high degree of skin color variation between these two extremes, generally correlating with uv exposure. the main exception to this rule is in the new world, where people have only lived for about 10, 000 to 15, 000 years and show a less pronounced degree of skin pigmentation. in recent times, humans have become increasingly mobile as a consequence of improved technology, domestication, environmental change, strong curiosity, and risk - taking.
skin tones, solar lentigenes emerge as small - to medium - sized brown patches of freckling that can grow and accumulate over time on areas of the body that receive the most unprotected sun exposure, such as the back of the hands, forearms, chest, and face. for those with darker skin colors, these discolorations can appear as patches or areas of ashen - gray skin. = = exposure to the sun = = melanin in the skin protects the body by absorbing solar radiation. in general, the more melanin there is in the skin the more solar radiation can be absorbed. excessive solar radiation causes direct and indirect dna damage to the skin and the body naturally combats and seeks to repair the damage and protect the skin by creating and releasing further melanin into the skin's cells. with the production of the melanin, the skin color darkens, but can also cause sunburn. the tanning process can also be created by artificial uv radiation. there are two different mechanisms involved. firstly, the uva - radiation creates oxidative stress, which in turn oxidizes existing melanin and leads to rapid darkening of the melanin, also known as ipd ( immediate pigment darkening ). secondly, there is an increase in production of melanin known as melanogenesis. melanogenesis leads to delayed tanning and first becomes visible about 72 hours after exposure. the tan that is created by an increased melanogenesis lasts much longer than the one that is caused by oxidation of existing melanin. tanning involves not just the increased melanin production in response to uv radiation but the thickening of the top layer of the epidermis, the stratum corneum. a person's natural skin color affects their reaction to exposure to the sun. generally, those who start out with darker skin color and more melanin have better abilities to tan. individuals with very light skin and albinos have no ability to tan. the biggest differences resulting from sun exposure are visible in individuals who start out with moderately pigmented brown skin : the change is dramatically visible as tan lines, where parts of the skin which tanned are delineated from unexposed skin. modern lifestyles and mobility have created mismatch between skin color and environment for many individuals. vitamin d deficiencies and uvr overexposure are concerns for many. it is important for these people individually to adjust their diet and lifestyle according to their skin color, the environment
effect of solar protection ( sunscreen only ) in preventing the development of basal - cell carcinoma or cutaneous squamous cell carcinoma found that there was insufficient evidence to demonstrate whether sunscreen was effective for the prevention of either of these keratinocyte - derived cancers. the review did ultimately state that the certainty of these results was low, so future evidence could very well alter this conclusion. one - third occur in non - sun - exposed areas ; thus, the pathogenesis is more complex than uv exposure as the cause. the use of a chemotherapeutic agent such as 5 - fluorouracil or imiquimod can prevent the development of skin cancer. it is usually recommended to individuals with extensive sun damage, a history of multiple skin cancers, or rudimentary forms of cancer ( i. e., solar keratosis ). it is often repeated every 2 to 3 years to further decrease the risk of skin cancer. = = treatment = = the following methods are employed in the treatment of basal - cell carcinoma ( bcc ) : = = = standard surgical excision = = = surgery to remove the basal - cell carcinoma affected area and the surrounding skin is thought to be the most effective treatment. a disadvantage with standard surgical excision is a reported higher recurrence rate of basal - cell cancers of the face, especially around the eyelids, nose, and facial structures. there is no clear approach, nor clear research comparing the effectiveness of mohs micrographic surgery versus surgical excision for bcc of the eye. for basal cell carcinoma excisions on the lower lip, the wound can be covered with a keystone flap. a keystone flap is achieved by creating a flap below the defect and pulling it superiorly to cover the wound. this can be performed if there is enough skin laxity to cover the defect and adequate blood supply to the flap. = = = mohs surgery = = = for many new ( primary ) and all recurrent forms of basal cell carcinoma after previous surgery, especially on the head, neck, hands, feet, genitalia, and anterior legs ( shins ), mohs surgery should be considered. mohs surgery ( or mohs micrographic surgery ) is an outpatient procedure, developed by frederic e. mohs in the 1930s, in which the tumor is surgically excised and then immediately examined under a microscope. it is a form of pathology processing called ccpdma, which means
goggles, safety gloves, and in some cases respirators, although the greater potential penetration through clothing and mobility in air of nanoparticles should be taken into account. : 48 β 63 = = see also = = health and safety hazards of nanomaterials radiation protection = = references = =
##lorine or chloramines may also be capable of chlorinating organic material in the natural aquatic environment. further, because residual chlorine is toxic to aquatic species, the treated effluent must also be chemically dechlorinated, adding to the complexity and cost of treatment. ultraviolet ( uv ) light can be used instead of chlorine, iodine, or other chemicals. because no chemicals are used, the treated water has no adverse effect on organisms that later consume it, as may be the case with other methods. uv radiation causes damage to the genetic structure of bacteria, viruses, and other pathogens, making them incapable of reproduction. the key disadvantages of uv disinfection are the need for frequent lamp maintenance and replacement and the need for a highly treated effluent to ensure that the target microorganisms are not shielded from the uv radiation ( i. e., any solids present in the treated effluent may protect microorganisms from the uv light ). in many countries, uv light is becoming the most common means of disinfection because of the concerns about the impacts of chlorine in chlorinating residual organics in the treated sewage and in chlorinating organics in the receiving water. as with uv treatment, heat sterilization also does not add chemicals to the water being treated. however, unlike uv, heat can penetrate liquids that are not transparent. heat disinfection can also penetrate solid materials within wastewater, sterilizing their contents. thermal effluent decontamination systems provide low resource, low maintenance effluent decontamination once installed. ozone ( o3 ) is generated by passing oxygen ( o2 ) through a high voltage potential resulting in a third oxygen atom becoming attached and forming o3. ozone is very unstable and reactive and oxidizes most organic material it comes in contact with, thereby destroying many pathogenic microorganisms. ozone is considered to be safer than chlorine because, unlike chlorine which has to be stored on site ( highly poisonous in the event of an accidental release ), ozone is generated on - site as needed from the oxygen in the ambient air. ozonation also produces fewer disinfection by - products than chlorination. a disadvantage of ozone disinfection is the high cost of the ozone generation equipment and the requirements for special operators. ozone sewage treatment requires the use of an ozone generator, which decontaminates the water
Answer:
|
wear nothing
| 0.3 |
Which would likely need a hot plate?
0. physics class
1. chemistry class
2. english class
3. math class
resistance is significant or not, magnitudes of the thermal resistances of the layers are compared with typical values of thermal contact resistance. thermal contact resistance is significant and may dominate for good heat conductors such as metals but can be neglected for poor heat conductors such as insulators. thermal contact conductance is an important factor in a variety of applications, largely because many physical systems contain a mechanical combination of two materials. some of the fields where contact conductance is of importance are : electronics electronic packaging heat sinks brackets industry nuclear reactor cooling gas turbine cooling internal combustion engines heat exchangers thermal insulation press hardening of automotive steels flight hypersonic flight vehicles thermal supervision for space vehicles residential / building science performance of building envelopes = = factors influencing contact conductance = = thermal contact conductance is a complicated phenomenon, influenced by many factors. experience shows that the most important ones are as follows : = = = contact pressure = = = for thermal transport between two contacting bodies, such as particles in a granular medium, the contact pressure, and the area of true contact area that arises from this, is the factor of most influence on overall contact conductance. governed by an interface's normal contact stiffness, as contact pressure grows, true contact area increases and contact conductance grows ( contact resistance becomes smaller ). since the contact pressure is the most important factor, most studies, correlations and mathematical models for measurement of contact conductance are done as a function of this factor. the thermal contact resistance of certain sandwich kinds of materials that are manufactured by rolling under high temperatures may sometimes be ignored because the decrease in thermal conductivity between them is negligible. = = = interstitial materials = = = no truly smooth surfaces really exist, and surface imperfections are visible under a microscope. as a result, when two bodies are pressed together, contact is only performed in a finite number of points, separated by relatively large gaps, as can be shown in fig. 2. since the actual contact area is reduced, another resistance for heat flow exists. the gases / fluids filling these gaps may largely influence the total heat flow across the interface. the thermal conductivity of the interstitial material and its pressure, examined through reference to the knudsen number, are the two properties governing its influence on contact conductance, and thermal transport in heterogeneous materials in general. in the absence of interstitial materials, as in a vacuum, the contact resistance will be much larger, since flow through the intimate contact points is dominant. = = = surface
a theoretical plate in many separation processes is a hypothetical zone or stage in which two phases, such as the liquid and vapor phases of a substance, establish an equilibrium with each other. such equilibrium stages may also be referred to as an equilibrium stage, ideal stage, or a theoretical tray. the performance of many separation processes depends on having series of equilibrium stages and is enhanced by providing more such stages. in other words, having more theoretical plates increases the efficiency of the separation process be it either a distillation, absorption, chromatographic, adsorption or similar process. = = applications = = the concept of theoretical plates and trays or equilibrium stages is used in the design of many different types of separation. = = = distillation columns = = = the concept of theoretical plates in designing distillation processes has been discussed in many reference texts. any physical device that provides good contact between the vapor and liquid phases present in industrial - scale distillation columns or laboratory - scale glassware distillation columns constitutes a " plate " or " tray ". since an actual, physical plate can never be a 100 % efficient equilibrium stage, the number of actual plates is more than the required theoretical plates. n a = n t e { \ displaystyle n _ { a } = { \ frac { n _ { t } } { e } } } where n a { \ displaystyle n _ { a } } is the number of actual, physical plates or trays, n t { \ displaystyle n _ { t } } is the number of theoretical plates or trays and e { \ displaystyle e } is the plate or tray efficiency. so - called bubble - cap or valve - cap trays are examples of the vapor and liquid contact devices used in industrial distillation columns. another example of vapor and liquid contact devices are the spikes in laboratory vigreux fractionating columns. the trays or plates used in industrial distillation columns are fabricated of circular steel plates and usually installed inside the column at intervals of about 60 to 75 cm ( 24 to 30 inches ) up the height of the column. that spacing is chosen primarily for ease of installation and ease of access for future repair or maintenance. an example of a very simple tray is a perforated tray. the desired contacting between vapor and liquid occurs as the vapor, flowing upwards through the perforations, comes into contact with the liquid flowing downwards through the perforations. in current modern practice, as shown in the adjacent diagram
a plate is a structural element which is characterized by a three - dimensional solid whose thickness is very small when compared with other dimensions. the effects of the loads that are expected to be applied on it only generate stresses whose resultants are, in practical terms, exclusively normal to the element's thickness. their mechanics are the main subject of the plate theory. thin plates are initially flat structural members bounded by two parallel planes, called faces, and a cylindrical surface, called an edge or boundary. the generators of the cylindrical surface are perpendicular to the plane faces. the distance between the plane faces is called the thickness ( h ) of the plate. it will be assumed that the plate thickness is small compared with other characteristic dimensions of the faces ( length, width, diameter, etc. ). geometrically, plates are bounded either by straight or curved boundaries. the static or dynamic loads carried by plates are predominantly perpendicular to the plate faces. = = see also = = shell bending of plates = = references = = stephen timoshenko & s. woinowsky - krieger ( 1940, 59 ) theory of plates and shells, mcgraw - hill book company.
) if they were connected by a wall permeable only to heat. = = see also = = glossary of engineering glossary of mechanical engineering glossary of structural engineering glossary of prestressed concrete terms glossary of architecture glossary of physics national council of examiners for engineering and surveying fundamentals of engineering examination principles and practice of engineering examination graduate aptitude test in engineering = = references = =
hot spots in subatomic physics are regions of high energy density or temperature in hadronic or nuclear matter. = = finite size effects = = hot spots are a manifestation of the finite size of the system : in subatomic physics this refers both to atomic nuclei, which consist of nucleons, as well as to nucleons themselves, which are made of quarks and gluons, other manifestations of finite sizes of these systems are seen in scattering of electrons on nuclei and nucleons. for nuclei in particular finite size effects manifest themselves also in the isomeric shift and isotopic shift. = = statistical methods in subatomic physics = = the formation of hot spots assumes the establishment of local equilibrium, which in its turn occurs if the thermal conductivity in the medium is sufficiently small. the notions of equilibrium and heat are statistical. the use of statistical methods assumes a large number of degrees of freedom. in macroscopic physics this number usually refers to the number of atoms or molecules, while in nuclear and particle physics it refers to the energy level density. = = hot spots in nucleons = = local equilibrium is the precursor of global equilibrium and the hot spot effect can be used to determine how fast, if at all, the transition from local to global equilibrium takes place. that this transition does not always happen follows from the fact that the duration of a strong interaction reaction is quite short ( of the order of 10β22 β 10β23 seconds ) and the propagation of " heat ", i. e. of the excitation, through the finite sized body of the system takes a finite time, which is determined by the thermal conductivity of the matter the system is made of. indications of the transition between local and global equilibrium in strong interaction particle physics started to emerge in the 1960s and early 1970s. in high - energy strong interactions equilibrium is usually not complete. in these reactions, with the increase of laboratory energy one observes that the transverse momenta of produced particles have a tail, which deviates from the single exponential boltzmann spectrum, characteristic for global equilibrium. the slope or the effective temperature of this transverse momentum tail increases with increasing energy. these large transverse momenta were interpreted as being due to particles, which " leak " out before equilibrium is reached. similar observations had been made in nuclear reactions and were also attributed to pre - equilibrium effects. this interpretation suggested that the equilibrium is neither instantaneous, nor global, but rather local in space and time. by predicting a specific asymmetry
Answer:
|
chemistry class
| null |
Which would likely need a hot plate?
0. physics class
1. chemistry class
2. english class
3. math class
resistance is significant or not, magnitudes of the thermal resistances of the layers are compared with typical values of thermal contact resistance. thermal contact resistance is significant and may dominate for good heat conductors such as metals but can be neglected for poor heat conductors such as insulators. thermal contact conductance is an important factor in a variety of applications, largely because many physical systems contain a mechanical combination of two materials. some of the fields where contact conductance is of importance are : electronics electronic packaging heat sinks brackets industry nuclear reactor cooling gas turbine cooling internal combustion engines heat exchangers thermal insulation press hardening of automotive steels flight hypersonic flight vehicles thermal supervision for space vehicles residential / building science performance of building envelopes = = factors influencing contact conductance = = thermal contact conductance is a complicated phenomenon, influenced by many factors. experience shows that the most important ones are as follows : = = = contact pressure = = = for thermal transport between two contacting bodies, such as particles in a granular medium, the contact pressure, and the area of true contact area that arises from this, is the factor of most influence on overall contact conductance. governed by an interface's normal contact stiffness, as contact pressure grows, true contact area increases and contact conductance grows ( contact resistance becomes smaller ). since the contact pressure is the most important factor, most studies, correlations and mathematical models for measurement of contact conductance are done as a function of this factor. the thermal contact resistance of certain sandwich kinds of materials that are manufactured by rolling under high temperatures may sometimes be ignored because the decrease in thermal conductivity between them is negligible. = = = interstitial materials = = = no truly smooth surfaces really exist, and surface imperfections are visible under a microscope. as a result, when two bodies are pressed together, contact is only performed in a finite number of points, separated by relatively large gaps, as can be shown in fig. 2. since the actual contact area is reduced, another resistance for heat flow exists. the gases / fluids filling these gaps may largely influence the total heat flow across the interface. the thermal conductivity of the interstitial material and its pressure, examined through reference to the knudsen number, are the two properties governing its influence on contact conductance, and thermal transport in heterogeneous materials in general. in the absence of interstitial materials, as in a vacuum, the contact resistance will be much larger, since flow through the intimate contact points is dominant. = = = surface
a theoretical plate in many separation processes is a hypothetical zone or stage in which two phases, such as the liquid and vapor phases of a substance, establish an equilibrium with each other. such equilibrium stages may also be referred to as an equilibrium stage, ideal stage, or a theoretical tray. the performance of many separation processes depends on having series of equilibrium stages and is enhanced by providing more such stages. in other words, having more theoretical plates increases the efficiency of the separation process be it either a distillation, absorption, chromatographic, adsorption or similar process. = = applications = = the concept of theoretical plates and trays or equilibrium stages is used in the design of many different types of separation. = = = distillation columns = = = the concept of theoretical plates in designing distillation processes has been discussed in many reference texts. any physical device that provides good contact between the vapor and liquid phases present in industrial - scale distillation columns or laboratory - scale glassware distillation columns constitutes a " plate " or " tray ". since an actual, physical plate can never be a 100 % efficient equilibrium stage, the number of actual plates is more than the required theoretical plates. n a = n t e { \ displaystyle n _ { a } = { \ frac { n _ { t } } { e } } } where n a { \ displaystyle n _ { a } } is the number of actual, physical plates or trays, n t { \ displaystyle n _ { t } } is the number of theoretical plates or trays and e { \ displaystyle e } is the plate or tray efficiency. so - called bubble - cap or valve - cap trays are examples of the vapor and liquid contact devices used in industrial distillation columns. another example of vapor and liquid contact devices are the spikes in laboratory vigreux fractionating columns. the trays or plates used in industrial distillation columns are fabricated of circular steel plates and usually installed inside the column at intervals of about 60 to 75 cm ( 24 to 30 inches ) up the height of the column. that spacing is chosen primarily for ease of installation and ease of access for future repair or maintenance. an example of a very simple tray is a perforated tray. the desired contacting between vapor and liquid occurs as the vapor, flowing upwards through the perforations, comes into contact with the liquid flowing downwards through the perforations. in current modern practice, as shown in the adjacent diagram
a plate is a structural element which is characterized by a three - dimensional solid whose thickness is very small when compared with other dimensions. the effects of the loads that are expected to be applied on it only generate stresses whose resultants are, in practical terms, exclusively normal to the element's thickness. their mechanics are the main subject of the plate theory. thin plates are initially flat structural members bounded by two parallel planes, called faces, and a cylindrical surface, called an edge or boundary. the generators of the cylindrical surface are perpendicular to the plane faces. the distance between the plane faces is called the thickness ( h ) of the plate. it will be assumed that the plate thickness is small compared with other characteristic dimensions of the faces ( length, width, diameter, etc. ). geometrically, plates are bounded either by straight or curved boundaries. the static or dynamic loads carried by plates are predominantly perpendicular to the plate faces. = = see also = = shell bending of plates = = references = = stephen timoshenko & s. woinowsky - krieger ( 1940, 59 ) theory of plates and shells, mcgraw - hill book company.
) if they were connected by a wall permeable only to heat. = = see also = = glossary of engineering glossary of mechanical engineering glossary of structural engineering glossary of prestressed concrete terms glossary of architecture glossary of physics national council of examiners for engineering and surveying fundamentals of engineering examination principles and practice of engineering examination graduate aptitude test in engineering = = references = =
hot spots in subatomic physics are regions of high energy density or temperature in hadronic or nuclear matter. = = finite size effects = = hot spots are a manifestation of the finite size of the system : in subatomic physics this refers both to atomic nuclei, which consist of nucleons, as well as to nucleons themselves, which are made of quarks and gluons, other manifestations of finite sizes of these systems are seen in scattering of electrons on nuclei and nucleons. for nuclei in particular finite size effects manifest themselves also in the isomeric shift and isotopic shift. = = statistical methods in subatomic physics = = the formation of hot spots assumes the establishment of local equilibrium, which in its turn occurs if the thermal conductivity in the medium is sufficiently small. the notions of equilibrium and heat are statistical. the use of statistical methods assumes a large number of degrees of freedom. in macroscopic physics this number usually refers to the number of atoms or molecules, while in nuclear and particle physics it refers to the energy level density. = = hot spots in nucleons = = local equilibrium is the precursor of global equilibrium and the hot spot effect can be used to determine how fast, if at all, the transition from local to global equilibrium takes place. that this transition does not always happen follows from the fact that the duration of a strong interaction reaction is quite short ( of the order of 10β22 β 10β23 seconds ) and the propagation of " heat ", i. e. of the excitation, through the finite sized body of the system takes a finite time, which is determined by the thermal conductivity of the matter the system is made of. indications of the transition between local and global equilibrium in strong interaction particle physics started to emerge in the 1960s and early 1970s. in high - energy strong interactions equilibrium is usually not complete. in these reactions, with the increase of laboratory energy one observes that the transverse momenta of produced particles have a tail, which deviates from the single exponential boltzmann spectrum, characteristic for global equilibrium. the slope or the effective temperature of this transverse momentum tail increases with increasing energy. these large transverse momenta were interpreted as being due to particles, which " leak " out before equilibrium is reached. similar observations had been made in nuclear reactions and were also attributed to pre - equilibrium effects. this interpretation suggested that the equilibrium is neither instantaneous, nor global, but rather local in space and time. by predicting a specific asymmetry
Answer:
|
physics class
| 0.3 |
A person has a cup of coffee in a ceramic cup. The coffee inside of the cup has chilled, so to increase the temperature, the person
0. puts the cup into the refrigerator
1. uses paper towels to wrap the cup in
2. sets the cup on an electric dish
3. makes the cup better by adding ice
ice from a dispenser in the door. domestic refrigerators and freezers for food storage are made in a range of sizes. among the smallest are peltier - type refrigerators designed to chill beverages. a large domestic refrigerator stands as tall as a person and may be about one metre ( 3 ft 3 in ) wide with a capacity of 0. 6 m3 ( 21 cu ft ). refrigerators and freezers may be free standing, or built into a kitchen. the refrigerator allows the modern household to keep food fresh for longer than before. freezers allow people to buy perishable food in bulk and eat it at leisure, and make bulk purchases. = = history = = = = = technology development = = = ancient origins ancient iranians were among the first to invent a form of cooler utilizing the principles of evaporative cooling and radiative cooling called yakhchals. these complexes used subterranean storage spaces, a large thickly insulated above - ground domed structure, and outfitted with badgirs ( wind - catchers ) and series of qanats ( aqueducts ). pre - electric refrigeration in modern times, before the invention of the modern electric refrigerator, icehouses and iceboxes were used to provide cool storage for most of the year. placed near freshwater lakes or packed with snow and ice during the winter, they were once very common. natural means are still used to cool foods today. on mountainsides, runoff from melting snow is a convenient way to cool drinks, and during the winter one can keep milk fresh much longer just by keeping it outdoors. the word " refrigeratory " was used at least as early as the 17th century. artificial refrigeration the history of artificial refrigeration began when scottish professor william cullen designed a small refrigerating machine in 1755. cullen used a pump to create a partial vacuum over a container of diethyl ether, which then boiled, absorbing heat from the surrounding air. the experiment even created a small amount of ice, but had no practical application at that time. in 1805, american inventor oliver evans described a closed vapor - compression refrigeration cycle for the production of ice by ether under vacuum. in 1820, the british scientist michael faraday liquefied ammonia and other gases by using high pressures and low temperatures, and in 1834, an american expatriate in great britain, jacob perkins, built the first working vapor - compression refrigeration system. it was a closed - cycle device that could
a refrigerator, commonly shortened to fridge, is a commercial and home appliance consisting of a thermally insulated compartment and a heat pump ( mechanical, electronic or chemical ) that transfers heat from its inside to its external environment so that its inside is cooled to a temperature below the room temperature. refrigeration is an essential food storage technique around the world. the low temperature reduces the reproduction rate of bacteria, so the refrigerator lowers the rate of spoilage. a refrigerator maintains a temperature a few degrees above the freezing point of water. the optimal temperature range for perishable food storage is 3 to 5 Β°c ( 37 to 41 Β°f ). a freezer is a specialized refrigerator, or portion of a refrigerator, that maintains its contents β temperature below the freezing point of water. the refrigerator replaced the icebox, which had been a common household appliance for almost a century and a half. the united states food and drug administration recommends that the refrigerator be kept at or below 4 Β°c ( 40 Β°f ) and that the freezer be regulated at β18 Β°c ( 0 Β°f ). the first cooling systems for food involved ice. artificial refrigeration began in the mid - 1750s, and developed in the early 1800s. in 1834, the first working vapor - compression refrigeration system, using the same technology seen in air conditioners, was built. the first commercial ice - making machine was invented in 1854. in 1913, refrigerators for home use were invented. in 1923 frigidaire introduced the first self - contained unit. the introduction of freon in the 1920s expanded the refrigerator market during the 1930s. home freezers as separate compartments ( larger than necessary just for ice cubes ) were introduced in 1940. frozen foods, previously a luxury item, became commonplace. freezer units are used in households as well as in industry and commerce. commercial refrigerator and freezer units were in use for almost 40 years prior to the common home models. the freezer - over - refrigerator style had been the basic style since the 1940s, until modern, side - by - side refrigerators broke the trend. a vapor compression cycle is used in most household refrigerators, refrigerator β freezers and freezers. newer refrigerators may include automatic defrosting, chilled water, and ice from a dispenser in the door. domestic refrigerators and freezers for food storage are made in a range of sizes. among the smallest are peltier - type refrigerators designed to chill beverages. a large domestic refrigerator stands as
and sensory properties. however, ohmic heating is limited by viscosity, electrical conductivity, and fouling deposits. although ohmic heating has not yet been approved by the food and drug administration ( fda ) for commercial use, this method has many potential applications, ranging from cooking to fermentation. there are different configurations for continuous ohmic heating systems, but in the most basic process, a power supply or generator is needed to produce electrical current. electrodes, in direct contact with food, pass electric current through the matrix. the distance between the electrodes can be adjusted to achieve the optimum electrical field strength. the generator creates the electrical current which flows to the first electrode and passes through the food product placed in the electrode gap. the food product resists the flow of current causing internal heating. the current continues to flow to the second electrode and back to the power source to close the circuit. the insulator caps around the electrodes controls the environment within the system. the electrical field strength and the residence time are the key process parameters which affect heat generation. the ideal foods for ohmic heating are viscous with particulates. thick soups sauces stews salsa fruit in a syrup medium milk ice cream mix egg whey heat sensitive liquids soymilk the efficiency by which electricity is converted to heat depends upon on salt, water, and fat content due to their thermal conductivity and resistance factors. in particulate foods, the particles heat up faster than the liquid matrix due to higher resistance to electricity and matching conductivity can contribute to uniform heating. this prevents overheating of the liquid matrix while particles receive sufficient heat processing. table 1 shows the electrical conductivity values of certain foods to display the effect of composition and salt concentration. the high electrical conductivity values represent a larger number of ionic compounds suspended in the product, which is directly proportional to the rate of heating. this value is increased in the presence of polar compounds, like acids and salts, but decreased with nonpolar compounds, like fats. electrical conductivity of food materials generally increases with temperature, and can change if there are structural changes caused during heating such as gelatinization of starch. density, ph, and specific heat of various components in a food matrix can also influence heating rate. benefits of ohmic heating include : uniform and rapid heating ( > 1Β°csβ1 ), less cooking time, better energy efficiency, lower capital cost, and heating simulataneously throughout food's volume as compared to aseptic processing, canning,
an ice cube is a small piece of ice, which is typically rectangular as viewed from above and trapezoidal as viewed from the side. ice cubes are products of mechanical refrigeration and are usually produced to cool beverages. they may be made at home in a freezer with an ice tray or in an automated ice - making accessory. they may also be produced industrially and sold commercially. = = origin of production = = american physician and inventor john gorrie built a refrigerator in 1844 to produce ice in cool air. his refrigerator produced ice which hung from the ceiling in a basin to lower the ambient room temperature. during his time, bad air quality was thought to cause disease. therefore, in order to help prevent and treat sickness, he pushed for the draining of swamps and the cooling of sickrooms. = = production = = = = = trays and bags = = = ice cube trays are designed to be filled with water, then placed in a freezer until the water freezes into ice, producing ice cubes. ice trays are often flexible, so the frozen cubes can be easily removed by flexing the tray. " twist ice trays " have a simple spring - loaded mechanism with a lever that is used to turn the tray upside down and flex at the same time, such that the cubes that drop are collected in a removable tray below. the spring returns the ice cube tray to its upright position without having to remove it from the freezer, which can save time and reduce accidental mess β though the tray has to be removed to be collected, the ice cube tray still has to be removed to be refilled. an alternative system is an aluminium tray with a lever that raises the ice cubes, freeing them from the tray. a motorized version of this is found in most automatic ice - making freezers. while the usual shape of the ice cube is roughly cubical, some ice trays form hemispherical or cylindrical shapes ; others produce blocks of ice in seasonal, festive, or other shapes. occasionally, edible items are frozen inside ice cubes at home and in commercial production. lloyd groff copeman invented a rubber ice tray after noticing that slush and ice flaked off his rubber boots rather than adhering to them while walking through some woods collecting sap for maple syrup. recalling this 1928 incident over lunch with his patent attorney, he conducted experiments using rubber cups, which led to practical designs and patents for different types of tray ; these included a metal tray
\ geq 0 } the third law imposes Ξ± > 0 { \ displaystyle \ alpha > 0 }, guaranteeing that at absolute zero the entropy production at the cold bath is zero : s c = 0 { \ displaystyle { \ dot { s } } _ { \ text { c } } = 0 }. this requirement leads to the scaling condition of the heat current j c t c Ξ± + 1 { \ displaystyle { j } _ { \ text { c } } \ propto t _ { \ text { c } } ^ { \ alpha + 1 } }. the second formulation, known as the unattainability principle can be rephrased as ; no refrigerator can cool a system to absolute zero temperature at finite time. the dynamics of the cooling process is governed by the equation j c ( t c ( t ) ) = β c v ( t c ( t ) ) d t c ( t ) d t. { \ displaystyle { j } _ { \ text { c } } ( t _ { \ text { c } } ( t ) ) = - c _ { v } ( t _ { \ text { c } } ( t ) ) { \ frac { dt _ { \ text { c } } ( t ) } { dt } } ~ ~. } where c v ( t c ) { \ displaystyle c _ { v } ( t _ { \ text { c } } ) } is the heat capacity of the bath. taking j c t c Ξ± + 1 { \ displaystyle { j } _ { \ text { c } } \ propto t _ { \ text { c } } ^ { \ alpha + 1 } } and c v t c Ξ· { \ displaystyle c _ { v } \ sim t _ { \ text { c } } ^ { \ eta } } with Ξ· β₯ 0 { \ displaystyle { \ eta } \ geq 0 }, we can quantify this formulation by evaluating the characteristic exponent ΞΆ { \ displaystyle \ zeta } of the cooling process, d t c ( t ) d t β t c ΞΆ, t c β 0, ΞΆ = Ξ± β Ξ· + 1 { \ displaystyle { \ frac { dt _ { \ text { c } } ( t ) } { dt } } \ propto - t _ { \ text { c } } ^ { \ zeta }, ~ ~ ~ ~ ~ t _ { \ text { c } }
Answer:
|
sets the cup on an electric dish
| null |
A person has a cup of coffee in a ceramic cup. The coffee inside of the cup has chilled, so to increase the temperature, the person
0. puts the cup into the refrigerator
1. uses paper towels to wrap the cup in
2. sets the cup on an electric dish
3. makes the cup better by adding ice
ice from a dispenser in the door. domestic refrigerators and freezers for food storage are made in a range of sizes. among the smallest are peltier - type refrigerators designed to chill beverages. a large domestic refrigerator stands as tall as a person and may be about one metre ( 3 ft 3 in ) wide with a capacity of 0. 6 m3 ( 21 cu ft ). refrigerators and freezers may be free standing, or built into a kitchen. the refrigerator allows the modern household to keep food fresh for longer than before. freezers allow people to buy perishable food in bulk and eat it at leisure, and make bulk purchases. = = history = = = = = technology development = = = ancient origins ancient iranians were among the first to invent a form of cooler utilizing the principles of evaporative cooling and radiative cooling called yakhchals. these complexes used subterranean storage spaces, a large thickly insulated above - ground domed structure, and outfitted with badgirs ( wind - catchers ) and series of qanats ( aqueducts ). pre - electric refrigeration in modern times, before the invention of the modern electric refrigerator, icehouses and iceboxes were used to provide cool storage for most of the year. placed near freshwater lakes or packed with snow and ice during the winter, they were once very common. natural means are still used to cool foods today. on mountainsides, runoff from melting snow is a convenient way to cool drinks, and during the winter one can keep milk fresh much longer just by keeping it outdoors. the word " refrigeratory " was used at least as early as the 17th century. artificial refrigeration the history of artificial refrigeration began when scottish professor william cullen designed a small refrigerating machine in 1755. cullen used a pump to create a partial vacuum over a container of diethyl ether, which then boiled, absorbing heat from the surrounding air. the experiment even created a small amount of ice, but had no practical application at that time. in 1805, american inventor oliver evans described a closed vapor - compression refrigeration cycle for the production of ice by ether under vacuum. in 1820, the british scientist michael faraday liquefied ammonia and other gases by using high pressures and low temperatures, and in 1834, an american expatriate in great britain, jacob perkins, built the first working vapor - compression refrigeration system. it was a closed - cycle device that could
a refrigerator, commonly shortened to fridge, is a commercial and home appliance consisting of a thermally insulated compartment and a heat pump ( mechanical, electronic or chemical ) that transfers heat from its inside to its external environment so that its inside is cooled to a temperature below the room temperature. refrigeration is an essential food storage technique around the world. the low temperature reduces the reproduction rate of bacteria, so the refrigerator lowers the rate of spoilage. a refrigerator maintains a temperature a few degrees above the freezing point of water. the optimal temperature range for perishable food storage is 3 to 5 Β°c ( 37 to 41 Β°f ). a freezer is a specialized refrigerator, or portion of a refrigerator, that maintains its contents β temperature below the freezing point of water. the refrigerator replaced the icebox, which had been a common household appliance for almost a century and a half. the united states food and drug administration recommends that the refrigerator be kept at or below 4 Β°c ( 40 Β°f ) and that the freezer be regulated at β18 Β°c ( 0 Β°f ). the first cooling systems for food involved ice. artificial refrigeration began in the mid - 1750s, and developed in the early 1800s. in 1834, the first working vapor - compression refrigeration system, using the same technology seen in air conditioners, was built. the first commercial ice - making machine was invented in 1854. in 1913, refrigerators for home use were invented. in 1923 frigidaire introduced the first self - contained unit. the introduction of freon in the 1920s expanded the refrigerator market during the 1930s. home freezers as separate compartments ( larger than necessary just for ice cubes ) were introduced in 1940. frozen foods, previously a luxury item, became commonplace. freezer units are used in households as well as in industry and commerce. commercial refrigerator and freezer units were in use for almost 40 years prior to the common home models. the freezer - over - refrigerator style had been the basic style since the 1940s, until modern, side - by - side refrigerators broke the trend. a vapor compression cycle is used in most household refrigerators, refrigerator β freezers and freezers. newer refrigerators may include automatic defrosting, chilled water, and ice from a dispenser in the door. domestic refrigerators and freezers for food storage are made in a range of sizes. among the smallest are peltier - type refrigerators designed to chill beverages. a large domestic refrigerator stands as
and sensory properties. however, ohmic heating is limited by viscosity, electrical conductivity, and fouling deposits. although ohmic heating has not yet been approved by the food and drug administration ( fda ) for commercial use, this method has many potential applications, ranging from cooking to fermentation. there are different configurations for continuous ohmic heating systems, but in the most basic process, a power supply or generator is needed to produce electrical current. electrodes, in direct contact with food, pass electric current through the matrix. the distance between the electrodes can be adjusted to achieve the optimum electrical field strength. the generator creates the electrical current which flows to the first electrode and passes through the food product placed in the electrode gap. the food product resists the flow of current causing internal heating. the current continues to flow to the second electrode and back to the power source to close the circuit. the insulator caps around the electrodes controls the environment within the system. the electrical field strength and the residence time are the key process parameters which affect heat generation. the ideal foods for ohmic heating are viscous with particulates. thick soups sauces stews salsa fruit in a syrup medium milk ice cream mix egg whey heat sensitive liquids soymilk the efficiency by which electricity is converted to heat depends upon on salt, water, and fat content due to their thermal conductivity and resistance factors. in particulate foods, the particles heat up faster than the liquid matrix due to higher resistance to electricity and matching conductivity can contribute to uniform heating. this prevents overheating of the liquid matrix while particles receive sufficient heat processing. table 1 shows the electrical conductivity values of certain foods to display the effect of composition and salt concentration. the high electrical conductivity values represent a larger number of ionic compounds suspended in the product, which is directly proportional to the rate of heating. this value is increased in the presence of polar compounds, like acids and salts, but decreased with nonpolar compounds, like fats. electrical conductivity of food materials generally increases with temperature, and can change if there are structural changes caused during heating such as gelatinization of starch. density, ph, and specific heat of various components in a food matrix can also influence heating rate. benefits of ohmic heating include : uniform and rapid heating ( > 1Β°csβ1 ), less cooking time, better energy efficiency, lower capital cost, and heating simulataneously throughout food's volume as compared to aseptic processing, canning,
an ice cube is a small piece of ice, which is typically rectangular as viewed from above and trapezoidal as viewed from the side. ice cubes are products of mechanical refrigeration and are usually produced to cool beverages. they may be made at home in a freezer with an ice tray or in an automated ice - making accessory. they may also be produced industrially and sold commercially. = = origin of production = = american physician and inventor john gorrie built a refrigerator in 1844 to produce ice in cool air. his refrigerator produced ice which hung from the ceiling in a basin to lower the ambient room temperature. during his time, bad air quality was thought to cause disease. therefore, in order to help prevent and treat sickness, he pushed for the draining of swamps and the cooling of sickrooms. = = production = = = = = trays and bags = = = ice cube trays are designed to be filled with water, then placed in a freezer until the water freezes into ice, producing ice cubes. ice trays are often flexible, so the frozen cubes can be easily removed by flexing the tray. " twist ice trays " have a simple spring - loaded mechanism with a lever that is used to turn the tray upside down and flex at the same time, such that the cubes that drop are collected in a removable tray below. the spring returns the ice cube tray to its upright position without having to remove it from the freezer, which can save time and reduce accidental mess β though the tray has to be removed to be collected, the ice cube tray still has to be removed to be refilled. an alternative system is an aluminium tray with a lever that raises the ice cubes, freeing them from the tray. a motorized version of this is found in most automatic ice - making freezers. while the usual shape of the ice cube is roughly cubical, some ice trays form hemispherical or cylindrical shapes ; others produce blocks of ice in seasonal, festive, or other shapes. occasionally, edible items are frozen inside ice cubes at home and in commercial production. lloyd groff copeman invented a rubber ice tray after noticing that slush and ice flaked off his rubber boots rather than adhering to them while walking through some woods collecting sap for maple syrup. recalling this 1928 incident over lunch with his patent attorney, he conducted experiments using rubber cups, which led to practical designs and patents for different types of tray ; these included a metal tray
\ geq 0 } the third law imposes Ξ± > 0 { \ displaystyle \ alpha > 0 }, guaranteeing that at absolute zero the entropy production at the cold bath is zero : s c = 0 { \ displaystyle { \ dot { s } } _ { \ text { c } } = 0 }. this requirement leads to the scaling condition of the heat current j c t c Ξ± + 1 { \ displaystyle { j } _ { \ text { c } } \ propto t _ { \ text { c } } ^ { \ alpha + 1 } }. the second formulation, known as the unattainability principle can be rephrased as ; no refrigerator can cool a system to absolute zero temperature at finite time. the dynamics of the cooling process is governed by the equation j c ( t c ( t ) ) = β c v ( t c ( t ) ) d t c ( t ) d t. { \ displaystyle { j } _ { \ text { c } } ( t _ { \ text { c } } ( t ) ) = - c _ { v } ( t _ { \ text { c } } ( t ) ) { \ frac { dt _ { \ text { c } } ( t ) } { dt } } ~ ~. } where c v ( t c ) { \ displaystyle c _ { v } ( t _ { \ text { c } } ) } is the heat capacity of the bath. taking j c t c Ξ± + 1 { \ displaystyle { j } _ { \ text { c } } \ propto t _ { \ text { c } } ^ { \ alpha + 1 } } and c v t c Ξ· { \ displaystyle c _ { v } \ sim t _ { \ text { c } } ^ { \ eta } } with Ξ· β₯ 0 { \ displaystyle { \ eta } \ geq 0 }, we can quantify this formulation by evaluating the characteristic exponent ΞΆ { \ displaystyle \ zeta } of the cooling process, d t c ( t ) d t β t c ΞΆ, t c β 0, ΞΆ = Ξ± β Ξ· + 1 { \ displaystyle { \ frac { dt _ { \ text { c } } ( t ) } { dt } } \ propto - t _ { \ text { c } } ^ { \ zeta }, ~ ~ ~ ~ ~ t _ { \ text { c } }
Answer:
|
puts the cup into the refrigerator
| 0.3 |
Paper suitable for recycling is often used to produce
0. aluminum cans
1. plastic bottles
2. cellulose nanofibers
3. glass bottles
example, the addition of a resistive heater for electrothermal conversion ( e. g. single walled carbon nanotubes ) can allow for an on - demand mechanical property switch via an electric current. alternatively, by adding a filler like graphene oxide, light irradiation can be used for an induced photo - thermal effect allowing for switching of the mechanical properties as a response to light - irradiation. other interesting nanoparticles for the application in cans include clay nanosheets, graphene and cellulose. = = = 3d printing = = = in recent years, 3d printing, or additive manufacturing ( am ), saw rapid developments as the technique became more and more popular. currently, plastics are the most common raw material used for 3d printing due to their wide availability, diversity and light weight. the versatility of am and its significant development resulted in its use for many applications ranging from manufacturing and medical sectors to the custom art and design sector. with the market of 3d printing expected to grow even further in the coming years, the use of cans as a resource for am is under investigation as a replacement for traditional thermosets, which could make up 22 % of the global market for am by the end of 2029. by replacing traditional thermoset ink with can - based inks, complicated 3d geometries can still be printed that behave like traditional thermosets with excellent mechanical properties at service conditions, but can later also be recycled into new ink for the next round of 3d printing. one example involved the 3d printing of an epoxy ink which is able to undergo transesterification reactions after printing. during the printing cycle, the ink is first slightly cured before being printed at high temperature into the desired 3d structure, and followed by a second curing step in an oven after printing. the printed epoxy parts can then be recycled by dissolving in ethylene glycol at high temperature and reused as ink in a new printing cycle. = = chemistries used in cans = = various dynamic chemistries have already been incorporated in cans ; some of the more notable ones include transesterification, diels - alder exchange, imine metathesis, disulfide exchange, transamination of vinylogous urethanes, transcarbamoylation of urethanes, olefin metathesis, and trans - n - alkylation of 1, 2, 3 - triazolium salts. = = sulfur - based cans = =
paper engineering is a branch of engineering that deals with the usage of physical science ( e. g. chemistry and physics ) and life sciences ( e. g. biology and biochemistry ) in conjunction with mathematics as applied to the converting of raw materials into useful paper products and co - products. the field applies various principles in process engineering and unit operations to the manufacture of paper, chemicals, energy and related materials. the following timeline shows some of the key steps in the development of the science of chemical and bioprocess engineering : from a heritage perspective, the field encompasses the design and analysis of a wide variety of thermal, chemical and biochemical unit operations employed in the manufacture of pulp and paper, and addresses the preparation of its raw materials from trees or other natural resources via a pulping process, chemical and mechanical pretreatment of these recovered biopolymer ( e. g. principally, although not solely, cellulose - based ) fibers in a fluid suspension, the high - speed forming and initial dewatering of a non - woven web, the development of bulk sheet properties via control of energy and mass transfer operations, as well as post - treatment of the sheet with coating, calendering, and other chemical and mechanical processes. = = applications = = today, the field of paper and chemical engineering is applied to the manufacture of a wide variety of products. the forestry and biology, chemical science, ( bio ) chemical industry scope manufactures organic and agrochemicals ( fertilizers, insecticides, herbicides ), oleochemicals, fragrances and flavors, food, feed, pharmaceuticals, nutraceuticals, chemicals, polymers and power from biological materials. the resulting products of paper engineering including paper, cardboard, and various paper derivatives are widely used in everyday life. in addition to being a subset of chemical engineering, the field of paper engineering is closely linked to forest management, product recycling, and the mass production of paper β based media. = = methods = = = = = mechanical pulping = = = in the process of mechanical pulping, " grinding " and " refining " are the two main methods used to create the pulp. grinding is the method of pressing logs and chips against a turning stone to produce fibers. refiner pulping is treating wood chips with chemicals or heat and then crushing the objects between two disks, one or both of which are rotating. there are four main types of refiner pulping, which includes refiner mechanical pulping, thermo - mechanical pulping
recycle most plastic products regardless of their ric. this has led some communities to instruct residents to refer to the form of packaging ( i. e. " bottles ", " tubs ", " lids ", etc. ) when determining what to include in a curbside recycling bin, rather than instructing them to rely on the ric. to further alleviate consumer confusion, the american chemistry council launched the " recycling terms & tools " program to promote standardized language that can be used to educate consumers about how to recycle plastic products. however, even when it is technically possible to recycle a particular plastic, it is often economically unfeasible to recycle it, and this can mislead consumers into thinking that more plastic is recycled than really is. in the u. s. in 2018, only 8. 5 % of plastic waste was recycled. = = see also = = list of symbols recycling codes plastic recycling thermoplastic β softens with heat thermosetting polymer β does not soften with heat = = references = = = = external links = = official website
filter paper is a semi - permeable paper barrier placed perpendicular to a liquid or air flow. it is used to separate fine solid particles from liquids or gases. the raw materials are typically different paper pulps. the pulp may be made from softwood, hardwood, fiber crops, or mineral fibers. = = properties = = filter paper has various properties. the important parameters are wet strength, porosity, particle retention, volumetric flow rate, compatibility, efficiency and capacity. there are two mechanisms of filtration with paper ; volume, and surface. by volume filtration, the particles are caught in the bulk of the filter paper. by surface filtration, the particles are caught on the paper surface. filter paper is mostly used because of the ability of a small piece of filter paper to absorb a significant volume of liquid. = = manufacture = = the raw materials are different paper pulps. the pulp may be from softwood, hardwood, fiber crops, mineral fibers. for high quality filters, dissolving pulp and mercerised pulp are used. most filter papers are made using small paper machines. for laboratory filters, the machines may be as small as 50 cm in width. the paper is often creped to improve porosity. the filter papers may also be treated with reagents or impregnation to get the right properties. = = types = = = = = air filters = = = the main application for air filters are combustion air to engines. the filter papers are transformed into filter cartridges, which then is fitted to a holder. the construction of the cartridges mostly requires that the paper is stiff enough to be self - supporting. a paper for air filters needs to be very porous and have a weight of 100 β 200 g / m2. normally particularly long fibrous pulp that is mercerised is used to get these properties. the paper is normally impregnated to improve the resistance to moisture. : 113 some heavy duty qualities are made to be rinsed and thereby extend the life of the filter. = = = coffee and tea = = = historically, blotting paper or cloth were used to extract filter coffee. modern coffee filters of paper are made from about 100 g / m2 creped paper. the creping allows the coffee to flow freely between the filter and the filtration funnel. the raw materials ( pulp ) for the filter paper are coarse long fiber, often from fast growing trees. for example, melitta uses up to 60 % of bambus in
treating wood chips with chemicals or heat and then crushing the objects between two disks, one or both of which are rotating. there are four main types of refiner pulping, which includes refiner mechanical pulping, thermo - mechanical pulping, chemi - mechanical pulping, and chemithermomechanical pulping. further descriptions of each process are contained in this link : mechanical pulping, when compared to chemical pulping, is relatively inexpensive and has a high pulp yield ( 85 β 95 % ). however, the paper created is generally weak since it retains the lignin. = = = chemical pulping = = = the process of chemical pulping is used to chemically disband the lignin found in the cell walls of the material undergoing the process. after the cellulose fibers are separated from the lignin, a pulp is created which can then be treated to create durable paper, boxes, and corrugated cardboard. chemical pulping can be characterized by two main methods : sulfate ( kraft process ) pulping and sulfite pulping, and these two methods have different benefits. sulfate pulping can be performed on a wide range of tree varieties and results in the creation of a strong type of paper. conversely, sulfite pulping results in a higher volume of pulp which is easier to bleach and process. however, sulfate pulping is more widely used since the product is more durable and the chemicals used in the process can be recovered, thus resulting in minimal environmental pollution. = = = further pulp processing = = = the pulp is then processed through an apparatus which renders the pulp as a mesh of fibers. this fiber network is then pressed to remove all water contents, and the paper is subsequently dried to remove all traces of moisture. = = = finishing = = = after the above processes have been completed, the resulting paper is coated with a minuscule amount of china clay or calcium carbonate to modify the surface, and the paper is then re - sized depending on its intended purpose. = = = product recycling = = = generally, the material to be recycled first undergoes mechanical or chemical pulping to render it in pulp form. the resulting pulp is then processed in the same way normal pulp is processed ; however, original fiber is sometimes added to enhance the quality and appearance of the product. = = related fields and topics = = today, the field of paper and bioprocess engineering is a diverse one, covering areas from biotechnology and nanotechnology to electricity generation.
Answer:
|
cellulose nanofibers
| null |
Paper suitable for recycling is often used to produce
0. aluminum cans
1. plastic bottles
2. cellulose nanofibers
3. glass bottles
example, the addition of a resistive heater for electrothermal conversion ( e. g. single walled carbon nanotubes ) can allow for an on - demand mechanical property switch via an electric current. alternatively, by adding a filler like graphene oxide, light irradiation can be used for an induced photo - thermal effect allowing for switching of the mechanical properties as a response to light - irradiation. other interesting nanoparticles for the application in cans include clay nanosheets, graphene and cellulose. = = = 3d printing = = = in recent years, 3d printing, or additive manufacturing ( am ), saw rapid developments as the technique became more and more popular. currently, plastics are the most common raw material used for 3d printing due to their wide availability, diversity and light weight. the versatility of am and its significant development resulted in its use for many applications ranging from manufacturing and medical sectors to the custom art and design sector. with the market of 3d printing expected to grow even further in the coming years, the use of cans as a resource for am is under investigation as a replacement for traditional thermosets, which could make up 22 % of the global market for am by the end of 2029. by replacing traditional thermoset ink with can - based inks, complicated 3d geometries can still be printed that behave like traditional thermosets with excellent mechanical properties at service conditions, but can later also be recycled into new ink for the next round of 3d printing. one example involved the 3d printing of an epoxy ink which is able to undergo transesterification reactions after printing. during the printing cycle, the ink is first slightly cured before being printed at high temperature into the desired 3d structure, and followed by a second curing step in an oven after printing. the printed epoxy parts can then be recycled by dissolving in ethylene glycol at high temperature and reused as ink in a new printing cycle. = = chemistries used in cans = = various dynamic chemistries have already been incorporated in cans ; some of the more notable ones include transesterification, diels - alder exchange, imine metathesis, disulfide exchange, transamination of vinylogous urethanes, transcarbamoylation of urethanes, olefin metathesis, and trans - n - alkylation of 1, 2, 3 - triazolium salts. = = sulfur - based cans = =
paper engineering is a branch of engineering that deals with the usage of physical science ( e. g. chemistry and physics ) and life sciences ( e. g. biology and biochemistry ) in conjunction with mathematics as applied to the converting of raw materials into useful paper products and co - products. the field applies various principles in process engineering and unit operations to the manufacture of paper, chemicals, energy and related materials. the following timeline shows some of the key steps in the development of the science of chemical and bioprocess engineering : from a heritage perspective, the field encompasses the design and analysis of a wide variety of thermal, chemical and biochemical unit operations employed in the manufacture of pulp and paper, and addresses the preparation of its raw materials from trees or other natural resources via a pulping process, chemical and mechanical pretreatment of these recovered biopolymer ( e. g. principally, although not solely, cellulose - based ) fibers in a fluid suspension, the high - speed forming and initial dewatering of a non - woven web, the development of bulk sheet properties via control of energy and mass transfer operations, as well as post - treatment of the sheet with coating, calendering, and other chemical and mechanical processes. = = applications = = today, the field of paper and chemical engineering is applied to the manufacture of a wide variety of products. the forestry and biology, chemical science, ( bio ) chemical industry scope manufactures organic and agrochemicals ( fertilizers, insecticides, herbicides ), oleochemicals, fragrances and flavors, food, feed, pharmaceuticals, nutraceuticals, chemicals, polymers and power from biological materials. the resulting products of paper engineering including paper, cardboard, and various paper derivatives are widely used in everyday life. in addition to being a subset of chemical engineering, the field of paper engineering is closely linked to forest management, product recycling, and the mass production of paper β based media. = = methods = = = = = mechanical pulping = = = in the process of mechanical pulping, " grinding " and " refining " are the two main methods used to create the pulp. grinding is the method of pressing logs and chips against a turning stone to produce fibers. refiner pulping is treating wood chips with chemicals or heat and then crushing the objects between two disks, one or both of which are rotating. there are four main types of refiner pulping, which includes refiner mechanical pulping, thermo - mechanical pulping
recycle most plastic products regardless of their ric. this has led some communities to instruct residents to refer to the form of packaging ( i. e. " bottles ", " tubs ", " lids ", etc. ) when determining what to include in a curbside recycling bin, rather than instructing them to rely on the ric. to further alleviate consumer confusion, the american chemistry council launched the " recycling terms & tools " program to promote standardized language that can be used to educate consumers about how to recycle plastic products. however, even when it is technically possible to recycle a particular plastic, it is often economically unfeasible to recycle it, and this can mislead consumers into thinking that more plastic is recycled than really is. in the u. s. in 2018, only 8. 5 % of plastic waste was recycled. = = see also = = list of symbols recycling codes plastic recycling thermoplastic β softens with heat thermosetting polymer β does not soften with heat = = references = = = = external links = = official website
filter paper is a semi - permeable paper barrier placed perpendicular to a liquid or air flow. it is used to separate fine solid particles from liquids or gases. the raw materials are typically different paper pulps. the pulp may be made from softwood, hardwood, fiber crops, or mineral fibers. = = properties = = filter paper has various properties. the important parameters are wet strength, porosity, particle retention, volumetric flow rate, compatibility, efficiency and capacity. there are two mechanisms of filtration with paper ; volume, and surface. by volume filtration, the particles are caught in the bulk of the filter paper. by surface filtration, the particles are caught on the paper surface. filter paper is mostly used because of the ability of a small piece of filter paper to absorb a significant volume of liquid. = = manufacture = = the raw materials are different paper pulps. the pulp may be from softwood, hardwood, fiber crops, mineral fibers. for high quality filters, dissolving pulp and mercerised pulp are used. most filter papers are made using small paper machines. for laboratory filters, the machines may be as small as 50 cm in width. the paper is often creped to improve porosity. the filter papers may also be treated with reagents or impregnation to get the right properties. = = types = = = = = air filters = = = the main application for air filters are combustion air to engines. the filter papers are transformed into filter cartridges, which then is fitted to a holder. the construction of the cartridges mostly requires that the paper is stiff enough to be self - supporting. a paper for air filters needs to be very porous and have a weight of 100 β 200 g / m2. normally particularly long fibrous pulp that is mercerised is used to get these properties. the paper is normally impregnated to improve the resistance to moisture. : 113 some heavy duty qualities are made to be rinsed and thereby extend the life of the filter. = = = coffee and tea = = = historically, blotting paper or cloth were used to extract filter coffee. modern coffee filters of paper are made from about 100 g / m2 creped paper. the creping allows the coffee to flow freely between the filter and the filtration funnel. the raw materials ( pulp ) for the filter paper are coarse long fiber, often from fast growing trees. for example, melitta uses up to 60 % of bambus in
treating wood chips with chemicals or heat and then crushing the objects between two disks, one or both of which are rotating. there are four main types of refiner pulping, which includes refiner mechanical pulping, thermo - mechanical pulping, chemi - mechanical pulping, and chemithermomechanical pulping. further descriptions of each process are contained in this link : mechanical pulping, when compared to chemical pulping, is relatively inexpensive and has a high pulp yield ( 85 β 95 % ). however, the paper created is generally weak since it retains the lignin. = = = chemical pulping = = = the process of chemical pulping is used to chemically disband the lignin found in the cell walls of the material undergoing the process. after the cellulose fibers are separated from the lignin, a pulp is created which can then be treated to create durable paper, boxes, and corrugated cardboard. chemical pulping can be characterized by two main methods : sulfate ( kraft process ) pulping and sulfite pulping, and these two methods have different benefits. sulfate pulping can be performed on a wide range of tree varieties and results in the creation of a strong type of paper. conversely, sulfite pulping results in a higher volume of pulp which is easier to bleach and process. however, sulfate pulping is more widely used since the product is more durable and the chemicals used in the process can be recovered, thus resulting in minimal environmental pollution. = = = further pulp processing = = = the pulp is then processed through an apparatus which renders the pulp as a mesh of fibers. this fiber network is then pressed to remove all water contents, and the paper is subsequently dried to remove all traces of moisture. = = = finishing = = = after the above processes have been completed, the resulting paper is coated with a minuscule amount of china clay or calcium carbonate to modify the surface, and the paper is then re - sized depending on its intended purpose. = = = product recycling = = = generally, the material to be recycled first undergoes mechanical or chemical pulping to render it in pulp form. the resulting pulp is then processed in the same way normal pulp is processed ; however, original fiber is sometimes added to enhance the quality and appearance of the product. = = related fields and topics = = today, the field of paper and bioprocess engineering is a diverse one, covering areas from biotechnology and nanotechnology to electricity generation.
Answer:
|
aluminum cans
| 0.3 |
In a plant such as a cactus, water is held within
0. the spikes on the stem
1. the lines of a stem
2. the inside of the leaves
3. the series of tubes in the body
lilies ( nymphaeaceae ) lotus ( nelumbo spp. ) featherfoil ( hottonia palustris ) eurasian water milfoil ( myriophyllum spicatum ) shining pondweed ( potamogeton lucens ) bladderwort ( utricularia spp. ) marginal plants are those which live with their roots under the water but the rest of the plant above the surface. these are usually placed so that the top of the pot is at or barely below the water level. examples of these are : iris or flag ( iris spp. ) water - plantain ( alisma spp. ) bulrush ( scirpus lacustris ) cattail ( typha latifolia ) taro ( colocasia esculenta ) arrowhead ( sagittaria latifolia ) bog - arum ( calla palustris ) pickerelweed ( pontederia cordata ) floating plants are those that are not anchored to the soil at all, but are free - floating on the surface. in water gardening, these are often used as a provider of shade to reduce algae growth in a pond. these are often extremely fast growing / multiplying. examples of these are : mosquito ferns ( azolla spp. ) water - spangle ( salvinia spp. ) frogbit ( hydrocharis morsus - ranae ) water lettuce ( pistia stratiotes ) water hyacinth ( eichhornia crassipes ) some areas of the united states do not allow certain of these plants to be sold or kept, as they have become invasive species in warmer areas of the country, such as florida and california. = = = algae = = = algae are found in almost all ponds. there are hundreds of species of algae that can grow in garden ponds, but they are usually noticed only when they become abundant. algae often grow in very high densities in ponds because of the high nutrient levels that are typical of garden ponds. generally, algae attaches itself to the sides of the pond and remains innocuous. some species of algae, such as " blanket weed ", can grow up to a foot a day under ideal conditions and can rapidly clog a garden pond. on the other hand, free floating algae are microscopic and are what cause pond water to appear green. blanket weed, although unsightly, is actually a sign that the water is clean and well - balanced. green water ( free floating algae ) means there are too
if the water potential of the root cells is more negative than that of the soil, usually due to high concentrations of solute, water can move by osmosis into the root from the soil. this causes a positive pressure that forces sap up the xylem towards the leaves. in some circumstances, the sap will be forced from the leaf through a hydathode in a phenomenon known as guttation. root pressure is highest in the morning before the opening of stomata and allow transpiration to begin. different plant species can have different root pressures even in a similar environment ; examples include up to 145 kpa in vitis riparia but around zero in celastrus orbiculatus. the primary force that creates the capillary action movement of water upwards in plants is the adhesion between the water and the surface of the xylem conduits. capillary action provides the force that establishes an equilibrium configuration, balancing gravity. when transpiration removes water at the top, the flow is needed to return to the equilibrium. transpirational pull results from the evaporation of water from the surfaces of cells in the leaves. this evaporation causes the surface of the water to recess into the pores of the cell wall. by capillary action, the water forms concave menisci inside the pores. the high surface tension of water pulls the concavity outwards, generating enough force to lift water as high as a hundred meters from ground level to a tree's highest branches. transpirational pull requires that the vessels transporting the water be very small in diameter ; otherwise, cavitation would break the water column. and as water evaporates from leaves, more is drawn up through the plant to replace it. when the water pressure within the xylem reaches extreme levels due to low water input from the roots ( if, for example, the soil is dry ), then the gases come out of solution and form a bubble β an embolism forms, which will spread quickly to other adjacent cells, unless bordered pits are present ( these have a plug - like structure called a torus, that seals off the opening between adjacent cells and stops the embolism from spreading ). even after an embolism has occurred, plants are able to refill the xylem and restore the functionality. = = = cohesion - tension theory = = = the cohesion - tension theory is a theory of intermolecular attraction that explains the process of water flow upwards
##laophyton and horneophyton have structures very similar to the hydroids of modern mosses. plants continued to innovate new ways of reducing the resistance to flow within their cells, thereby increasing the efficiency of their water transport. bands on the walls of tubes, in fact apparent from the early silurian onwards, are an early improvisation to aid the easy flow of water. banded tubes, as well as tubes with pits in their walls, were lignified and, when they form single celled conduits, are considered to be tracheids. these, the " next generation " of transport cell design, have a more rigid structure than hydroids, allowing them to cope with higher levels of water pressure. tracheids may have a single evolutionary origin, possibly within the hornworts, uniting all tracheophytes ( but they may have evolved more than once ). water transport requires regulation, and dynamic control is provided by stomata. by adjusting the amount of gas exchange, they can restrict the amount of water lost through transpiration. this is an important role where water supply is not constant, and indeed stomata appear to have evolved before tracheids, being present in the non - vascular hornworts. an endodermis probably evolved during the silu - devonian, but the first fossil evidence for such a structure is carboniferous. this structure in the roots covers the water transport tissue and regulates ion exchange ( and prevents unwanted pathogens etc. from entering the water transport system ). the endodermis can also provide an upwards pressure, forcing water out of the roots when transpiration is not enough of a driver. once plants had evolved this level of controlled water transport, they were truly homoiohydric, able to extract water from their environment through root - like organs rather than relying on a film of surface moisture, enabling them to grow to much greater size. as a result of their independence from their surroundings, they lost their ability to survive desiccation β a costly trait to retain. during the devonian, maximum xylem diameter increased with time, with the minimum diameter remaining pretty constant. by the middle devonian, the tracheid diameter of some plant lineages ( zosterophyllophytes ) had plateaued. wider tracheids allow water to be transported faster, but the overall transport rate depends also on the overall cross - sectional area of the xylem bundle itself. the increase in vascular bundle thickness further seems to correlate
a concave meniscus. manufacturers of glassware and other tools calibrate their measurement marks to account for the meniscus. this means that any instrument is calibrated for a specific liquid, usually water. = = capillary action = = menisci are a manifestation of capillary action, by which either surface adhesion pulls a liquid up to form a concave meniscus, or internal cohesion pulls the liquid down to form a convex meniscus. this phenomenon is important in transpirational pull in plants. when a tube of a narrow bore, often called a capillary tube, is dipped into a liquid and the liquid wets the tube ( with zero contact angle ), the liquid surface inside the tube forms a concave meniscus, which is a virtually spherical surface having the same radius, r, as the inside of the tube. the tube experiences a downward force of magnitude 2ΟrΟ, where Ο is the surface tension of the liquid. = = see also = = capillary pressure β pressure between two fluids from forces between the fluids and tube walls capillary surface β surface representing the interface between two different fluids du nouy ring method β method of measuring a liquid's surface tension sessile drop technique β method of determining the surface energy of a solid tensiometer ( surface tension ) β instrument which measures surface tension young β laplace equation β describing pressure difference over an interface in fluid mechanics = = references = = = = external links = = using menisci to measure surface tension
##perms, and they are absent in some archaic or " basal " lineages of the angiosperms : ( e. g., amborellaceae, tetracentraceae, trochodendraceae, and winteraceae ), and their secondary xylem is described by arthur cronquist as " primitively vesselless ". cronquist considered the vessels of gnetum to be convergent with those of angiosperms. whether the absence of vessels in basal angiosperms is a primitive condition is contested, the alternative hypothesis states that vessel elements originated in a precursor to the angiosperms and were subsequently lost. to photosynthesize, plants must absorb co2 from the atmosphere. however, this comes at a price : while stomata are open to allow co2 to enter, water can evaporate. water is lost much faster than co2 is absorbed, so plants need to replace it, and have developed systems to transport water from the moist soil to the site of photosynthesis. early plants sucked water between the walls of their cells, then evolved the ability to control water loss ( and co2 acquisition ) through the use of stomata. specialized water transport tissues soon evolved in the form of hydroids, tracheids, then secondary xylem, followed by an endodermis and ultimately vessels. the high co2 levels of silurian - devonian times, when plants were first colonizing land, meant that the need for water was relatively low. as co2 was withdrawn from the atmosphere by plants, more water was lost in its capture, and more elegant transport mechanisms evolved. as water transport mechanisms, and waterproof cuticles, evolved, plants could survive without being continually covered by a film of water. this transition from poikilohydry to homoiohydry opened up new potential for colonization. plants then needed a robust internal structure that held long narrow channels for transporting water from the soil to all the different parts of the above - soil plant, especially to the parts where photosynthesis occurred. during the silurian, co2 was readily available, so little water needed expending to acquire it. by the end of the carboniferous, when co2 levels had lowered to something approaching today's, around 17 times more water was lost per unit of co2 uptake. however, even in these " easy " early days, water was at a premium, and had to be transported to parts of the plant from the wet
Answer:
|
the series of tubes in the body
| null |
In a plant such as a cactus, water is held within
0. the spikes on the stem
1. the lines of a stem
2. the inside of the leaves
3. the series of tubes in the body
lilies ( nymphaeaceae ) lotus ( nelumbo spp. ) featherfoil ( hottonia palustris ) eurasian water milfoil ( myriophyllum spicatum ) shining pondweed ( potamogeton lucens ) bladderwort ( utricularia spp. ) marginal plants are those which live with their roots under the water but the rest of the plant above the surface. these are usually placed so that the top of the pot is at or barely below the water level. examples of these are : iris or flag ( iris spp. ) water - plantain ( alisma spp. ) bulrush ( scirpus lacustris ) cattail ( typha latifolia ) taro ( colocasia esculenta ) arrowhead ( sagittaria latifolia ) bog - arum ( calla palustris ) pickerelweed ( pontederia cordata ) floating plants are those that are not anchored to the soil at all, but are free - floating on the surface. in water gardening, these are often used as a provider of shade to reduce algae growth in a pond. these are often extremely fast growing / multiplying. examples of these are : mosquito ferns ( azolla spp. ) water - spangle ( salvinia spp. ) frogbit ( hydrocharis morsus - ranae ) water lettuce ( pistia stratiotes ) water hyacinth ( eichhornia crassipes ) some areas of the united states do not allow certain of these plants to be sold or kept, as they have become invasive species in warmer areas of the country, such as florida and california. = = = algae = = = algae are found in almost all ponds. there are hundreds of species of algae that can grow in garden ponds, but they are usually noticed only when they become abundant. algae often grow in very high densities in ponds because of the high nutrient levels that are typical of garden ponds. generally, algae attaches itself to the sides of the pond and remains innocuous. some species of algae, such as " blanket weed ", can grow up to a foot a day under ideal conditions and can rapidly clog a garden pond. on the other hand, free floating algae are microscopic and are what cause pond water to appear green. blanket weed, although unsightly, is actually a sign that the water is clean and well - balanced. green water ( free floating algae ) means there are too
if the water potential of the root cells is more negative than that of the soil, usually due to high concentrations of solute, water can move by osmosis into the root from the soil. this causes a positive pressure that forces sap up the xylem towards the leaves. in some circumstances, the sap will be forced from the leaf through a hydathode in a phenomenon known as guttation. root pressure is highest in the morning before the opening of stomata and allow transpiration to begin. different plant species can have different root pressures even in a similar environment ; examples include up to 145 kpa in vitis riparia but around zero in celastrus orbiculatus. the primary force that creates the capillary action movement of water upwards in plants is the adhesion between the water and the surface of the xylem conduits. capillary action provides the force that establishes an equilibrium configuration, balancing gravity. when transpiration removes water at the top, the flow is needed to return to the equilibrium. transpirational pull results from the evaporation of water from the surfaces of cells in the leaves. this evaporation causes the surface of the water to recess into the pores of the cell wall. by capillary action, the water forms concave menisci inside the pores. the high surface tension of water pulls the concavity outwards, generating enough force to lift water as high as a hundred meters from ground level to a tree's highest branches. transpirational pull requires that the vessels transporting the water be very small in diameter ; otherwise, cavitation would break the water column. and as water evaporates from leaves, more is drawn up through the plant to replace it. when the water pressure within the xylem reaches extreme levels due to low water input from the roots ( if, for example, the soil is dry ), then the gases come out of solution and form a bubble β an embolism forms, which will spread quickly to other adjacent cells, unless bordered pits are present ( these have a plug - like structure called a torus, that seals off the opening between adjacent cells and stops the embolism from spreading ). even after an embolism has occurred, plants are able to refill the xylem and restore the functionality. = = = cohesion - tension theory = = = the cohesion - tension theory is a theory of intermolecular attraction that explains the process of water flow upwards
##laophyton and horneophyton have structures very similar to the hydroids of modern mosses. plants continued to innovate new ways of reducing the resistance to flow within their cells, thereby increasing the efficiency of their water transport. bands on the walls of tubes, in fact apparent from the early silurian onwards, are an early improvisation to aid the easy flow of water. banded tubes, as well as tubes with pits in their walls, were lignified and, when they form single celled conduits, are considered to be tracheids. these, the " next generation " of transport cell design, have a more rigid structure than hydroids, allowing them to cope with higher levels of water pressure. tracheids may have a single evolutionary origin, possibly within the hornworts, uniting all tracheophytes ( but they may have evolved more than once ). water transport requires regulation, and dynamic control is provided by stomata. by adjusting the amount of gas exchange, they can restrict the amount of water lost through transpiration. this is an important role where water supply is not constant, and indeed stomata appear to have evolved before tracheids, being present in the non - vascular hornworts. an endodermis probably evolved during the silu - devonian, but the first fossil evidence for such a structure is carboniferous. this structure in the roots covers the water transport tissue and regulates ion exchange ( and prevents unwanted pathogens etc. from entering the water transport system ). the endodermis can also provide an upwards pressure, forcing water out of the roots when transpiration is not enough of a driver. once plants had evolved this level of controlled water transport, they were truly homoiohydric, able to extract water from their environment through root - like organs rather than relying on a film of surface moisture, enabling them to grow to much greater size. as a result of their independence from their surroundings, they lost their ability to survive desiccation β a costly trait to retain. during the devonian, maximum xylem diameter increased with time, with the minimum diameter remaining pretty constant. by the middle devonian, the tracheid diameter of some plant lineages ( zosterophyllophytes ) had plateaued. wider tracheids allow water to be transported faster, but the overall transport rate depends also on the overall cross - sectional area of the xylem bundle itself. the increase in vascular bundle thickness further seems to correlate
a concave meniscus. manufacturers of glassware and other tools calibrate their measurement marks to account for the meniscus. this means that any instrument is calibrated for a specific liquid, usually water. = = capillary action = = menisci are a manifestation of capillary action, by which either surface adhesion pulls a liquid up to form a concave meniscus, or internal cohesion pulls the liquid down to form a convex meniscus. this phenomenon is important in transpirational pull in plants. when a tube of a narrow bore, often called a capillary tube, is dipped into a liquid and the liquid wets the tube ( with zero contact angle ), the liquid surface inside the tube forms a concave meniscus, which is a virtually spherical surface having the same radius, r, as the inside of the tube. the tube experiences a downward force of magnitude 2ΟrΟ, where Ο is the surface tension of the liquid. = = see also = = capillary pressure β pressure between two fluids from forces between the fluids and tube walls capillary surface β surface representing the interface between two different fluids du nouy ring method β method of measuring a liquid's surface tension sessile drop technique β method of determining the surface energy of a solid tensiometer ( surface tension ) β instrument which measures surface tension young β laplace equation β describing pressure difference over an interface in fluid mechanics = = references = = = = external links = = using menisci to measure surface tension
##perms, and they are absent in some archaic or " basal " lineages of the angiosperms : ( e. g., amborellaceae, tetracentraceae, trochodendraceae, and winteraceae ), and their secondary xylem is described by arthur cronquist as " primitively vesselless ". cronquist considered the vessels of gnetum to be convergent with those of angiosperms. whether the absence of vessels in basal angiosperms is a primitive condition is contested, the alternative hypothesis states that vessel elements originated in a precursor to the angiosperms and were subsequently lost. to photosynthesize, plants must absorb co2 from the atmosphere. however, this comes at a price : while stomata are open to allow co2 to enter, water can evaporate. water is lost much faster than co2 is absorbed, so plants need to replace it, and have developed systems to transport water from the moist soil to the site of photosynthesis. early plants sucked water between the walls of their cells, then evolved the ability to control water loss ( and co2 acquisition ) through the use of stomata. specialized water transport tissues soon evolved in the form of hydroids, tracheids, then secondary xylem, followed by an endodermis and ultimately vessels. the high co2 levels of silurian - devonian times, when plants were first colonizing land, meant that the need for water was relatively low. as co2 was withdrawn from the atmosphere by plants, more water was lost in its capture, and more elegant transport mechanisms evolved. as water transport mechanisms, and waterproof cuticles, evolved, plants could survive without being continually covered by a film of water. this transition from poikilohydry to homoiohydry opened up new potential for colonization. plants then needed a robust internal structure that held long narrow channels for transporting water from the soil to all the different parts of the above - soil plant, especially to the parts where photosynthesis occurred. during the silurian, co2 was readily available, so little water needed expending to acquire it. by the end of the carboniferous, when co2 levels had lowered to something approaching today's, around 17 times more water was lost per unit of co2 uptake. however, even in these " easy " early days, water was at a premium, and had to be transported to parts of the plant from the wet
Answer:
|
the inside of the leaves
| 0.3 |
If a warmth is relocated from one thing to another, and one of the things is the producer of the heat, the source is the most likely to be
0. a stone
1. a vent
2. the moon
3. the sun
crystallization = = = magma in the earth is produced by partial melting of a source rock, ultimately in the mantle. the melt extracts a large portion of the " incompatible elements " from its source that are not stable in the major minerals. when magma rises above a certain depth the dissolved minerals start to crystallize at particular pressures and temperatures. the resulting solids remove various elements from the melt, and melt is thus depleted of those elements. study of trace elements in igneous rocks thus gives us information about what source melted by how much to produce a magma, and which minerals have been lost from the melt. = = = thermal diffusion = = = when material is unevenly heated, lighter material migrates toward hotter zones and heavier material migrates towards colder areas, which is known as thermophoresis, thermomigration, or the soret effect. this process can affect differentiation in magma chambers. a deeper understanding of this process can be drawn back to a study done on the hawaiian lava lakes. the drilling of these lakes led to the discovery of crystals formed within magma fronts. the magma containing concentrations of these large crystals or phenocrysts demonstrated differentiation through the chemical melt of crystals. = = lunar kreep = = on the moon, a distinctive basaltic material has been found that is high in " incompatible elements " such as potassium, rare earth elements, and phosphorus and is often referred to by the abbreviation kreep. it is also high in uranium and thorium. these elements are excluded from the major minerals of the lunar crust which crystallized out from its primeval magma ocean, and the kreep basalt may have been trapped as a chemical differentiate between the crust and the mantle, with occasional eruptions to the surface. = = = differentiation through collision = = = earth's moon probably formed out of material splashed into orbit by the impact of a large body into the early earth. differentiation on earth had probably already separated many lighter materials toward the surface, so that the impact removed a disproportionate amount of silicate material from earth, and left the majority of the dense metal behind. the moon's density is substantially less than that of earth, due to its lack of a large iron core. on earth, physical and chemical differentiation processes led to a crustal density of approximately 2700 kg / m3 compared to the 3400 kg / m3 density of the compositionally different mantle just below, and the average density of the planet as a whole is 5515 kg / m3. = =
, between two bodies or closed systems, have been determined for a process, so as to conform with the principle of conservation of energy or the first law of thermodynamics for closed systems ; this approach grew in the twentieth century, though was partly manifest in the nineteenth. = = = = thermodynamic stream of thinking = = = = in the thermodynamic stream of thinking, the specified mechanisms of heat transfer are conduction and radiation. these mechanisms presuppose recognition of temperature ; empirical temperature is enough for this purpose, though absolute temperature can also serve. in this stream of thinking, quantity of heat is defined primarily through calorimetry. though its definition of them differs from that of the mechanical stream of thinking, the empirical stream of thinking nevertheless presupposes the existence of adiabatic enclosures. it defines them through the concepts of heat and temperature. these two concepts are coordinately coherent in the sense that they arise jointly in the description of experiments of transfer of energy as heat. = = = = mechanical stream of thinking = = = = in the mechanical stream of thinking about a process of transfer of energy between two bodies or closed systems, heat transferred is defined as a residual amount of energy transferred after the energy transferred as work has been determined, assuming for the calculation the law of conservation of energy, without reference to the concept of temperature. there are five main elements of the underlying theory. the existence of states of thermodynamic equilibrium, determinable by precisely one ( called the non - deformation variable ) more variable of state than the number of independent work ( deformation ) variables. that a state of internal thermodynamic equilibrium of a body have a well defined internal energy, that is postulated by the first law of thermodynamics. the universality of the law of conservation of energy. the recognition of work as a form of energy transfer. the universal irreversibility of natural processes. the existence of adiabatic enclosures. the existence of walls permeable only to heat. axiomatic presentations of this stream of thinking vary slightly, but they intend to avoid the notions of heat and of temperature in their axioms. it is essential to this stream of thinking that heat is not presupposed as being measurable by calorimetry. it is essential to this stream of thinking that, for the specification of the thermodynamic state of a body or closed system, in addition to the variables of state called deformation variables,
low for theoretical models of seafloor spreading. the convective crustal heat transfer computed for the first time from the vent plumes was estimated to be many - fold the observed conductive heat flow at a spreading center. these observations pointed to the importance of convective heat flow at spreading centers and provided an answer to the low heat flow problem. the discovery of biological communities at low temperature warm vents at 21Β°n, populated by a benthic community the same or similar to that discovered at the galapagos spreading center, established that life forms found at the galapagos were not unique. further, the significance of discovering at the galapagos site and 21Β°n of a chemosynthetic ecosystem that was not dependent on sunlight, existed at high pressures, and was based on chemicals emitted via volcanism, provided a model for how life could have originated on earth. = = see also = = tanya atwater robert ballard jack corliss rachel haymon miriam kastner bruce p. luyendyk endeavor hydrothermal vents magic mountain ( vents offshore british columbia, canada ) rivera plate = = references = = = = further reading = = ballard, r. d. ; grassle, j. f. ( 1979 ). " incredible world of deep sea rifts ". national geographic. 156 : 680 β 705. ballard, robert d. ( 2017 - 03 - 21 ). the eternal darkness : a personal history of deep - sea exploration. hively, will ( new princeton science library ed. ). princeton, n. j. isbn 9780691175621. oclc 982214518. { { cite book } } : cs1 maint : location missing publisher ( link ) crane, kathleen. ( 2003 ). sea legs : tales of a woman oceanographer. boulder, colo. : westview press. isbn 978 - 0813340043. oclc 51553643. haymon, r. m. ( 2014 ), " hydrothermal vents at mid - ocean ridges ", reference module in earth systems and environmental sciences, elsevier, doi : 10. 1016 / b978 - 0 - 12 - 409548 - 9. 09050 - 3, isbn 9780124095489, retrieved 2019 - 06 - 27 macdonald, ken c. ; luyendyk, bruce p. ( 1981 ). " the crest of the east pacific rise ". scientific american. 244 ( 5 ) :
migration of anatectic melt flows down local pressure gradients with little or no crystallization. the network of channels through which the melt moved at this stage may be lost by compression of the melanosome, leaving isolated lenses of leucosome. the melt product gathers in an underlying channel where it becomes subject to differentiation. conduction is the principal mechanism of heat transfer in the continental crust ; where shallow layers have been exhumed or buried rapidly there is a corresponding inflection in the geothermal gradient. cooling due to surface exposure is conducted very slowly to deeper rocks so the deeper crust is slow to heat up and slow to cool. numerical models of crustal heating confirm slow cooling in the deep crust. therefore, once formed, anatectic melt can exist in the middle and lower crust for a very long period of time. it is squeezed laterally to form sills, laccolithic and lopolithic structures of mobile granulite at depths of c. 10 β 20 km. in outcrop today only stages of this process arrested during its initial rapid uplift are visible. wherever the resulting fractionated granulite rises steeply in the crust, water exits from its supercriticality phase, the granulite starts to crystallize, becomes firstly fractionated melt + crystals, then solid rock, whilst still at the conditions of temperature and pressure existing beyond 8 km. water, carbon dioxide, sulphur dioxide and other elements are exsolved under great pressure from the melt as it exits from supercritical conditions. these components rise rapidly towards the surface and contribute to formation of mineral deposits, volcanoes, mud volcanoes, geysers and hot springs. = = color - banded migmatites = = a leucosome is the lightest - colored part of migmatite. the melanosome is the darker part, and occurs between two leucosomes or, if remnants of the more or less unmodified parent rock ( mesosome ) are still present, it is arranged in rims around these remnants. when present, the mesosome is intermediate in color between leucosome and melanosome. the melanosome is a dark, mafic mineral band formed in migmatite which is melting into a eutaxitic texture ; often, this leads to the formation of granite. the melanosomes form bands with leucosomes, and in that context may be described as schlieren ( color banding ) or
migration of anatectic melt flows down local pressure gradients with little or no crystallization. the network of channels through which the melt moved at this stage may be lost by compression of the melanosome, leaving isolated lenses of leucosome. the melt product gathers in an underlying channel where it becomes subject to differentiation. conduction is the principal mechanism of heat transfer in the continental crust ; where shallow layers have been exhumed or buried rapidly there is a corresponding inflection in the geothermal gradient. cooling due to surface exposure is conducted very slowly to deeper rocks so the deeper crust is slow to heat up and slow to cool. numerical models of crustal heating confirm slow cooling in the deep crust. therefore, once formed, anatectic melt can exist in the middle and lower crust for a very long period of time. it is squeezed laterally to form sills, laccolithic and lopolithic structures of mobile granulite at depths of c. 10 β 20 km. in outcrop today only stages of this process arrested during its initial rapid uplift are visible. wherever the resulting fractionated granulite rises steeply in the crust, water exits from its supercriticality phase, the granulite starts to crystallize, becomes firstly fractionated melt + crystals, then solid rock, whilst still at the conditions of temperature and pressure existing beyond 8 km. water, carbon dioxide, sulphur dioxide and other elements are exsolved under great pressure from the melt as it exits from supercritical conditions. these components rise rapidly towards the surface and contribute to formation of mineral deposits, volcanoes, mud volcanoes, geysers and hot springs. = = color - banded migmatites = = a leucosome is the lightest - colored part of migmatite. the melanosome is the darker part, and occurs between two leucosomes or, if remnants of the more or less unmodified parent rock ( mesosome ) are still present, it is arranged in rims around these remnants. when present, the mesosome is intermediate in color between leucosome and melanosome. the melanosome is a dark, mafic mineral band formed in migmatite which is melting into a eutaxitic texture ; often, this leads to the formation of granite. the melanosomes form bands with leucosomes, and in that context may be described as schlieren ( color banding ) or
Answer:
|
the sun
| null |
If a warmth is relocated from one thing to another, and one of the things is the producer of the heat, the source is the most likely to be
0. a stone
1. a vent
2. the moon
3. the sun
crystallization = = = magma in the earth is produced by partial melting of a source rock, ultimately in the mantle. the melt extracts a large portion of the " incompatible elements " from its source that are not stable in the major minerals. when magma rises above a certain depth the dissolved minerals start to crystallize at particular pressures and temperatures. the resulting solids remove various elements from the melt, and melt is thus depleted of those elements. study of trace elements in igneous rocks thus gives us information about what source melted by how much to produce a magma, and which minerals have been lost from the melt. = = = thermal diffusion = = = when material is unevenly heated, lighter material migrates toward hotter zones and heavier material migrates towards colder areas, which is known as thermophoresis, thermomigration, or the soret effect. this process can affect differentiation in magma chambers. a deeper understanding of this process can be drawn back to a study done on the hawaiian lava lakes. the drilling of these lakes led to the discovery of crystals formed within magma fronts. the magma containing concentrations of these large crystals or phenocrysts demonstrated differentiation through the chemical melt of crystals. = = lunar kreep = = on the moon, a distinctive basaltic material has been found that is high in " incompatible elements " such as potassium, rare earth elements, and phosphorus and is often referred to by the abbreviation kreep. it is also high in uranium and thorium. these elements are excluded from the major minerals of the lunar crust which crystallized out from its primeval magma ocean, and the kreep basalt may have been trapped as a chemical differentiate between the crust and the mantle, with occasional eruptions to the surface. = = = differentiation through collision = = = earth's moon probably formed out of material splashed into orbit by the impact of a large body into the early earth. differentiation on earth had probably already separated many lighter materials toward the surface, so that the impact removed a disproportionate amount of silicate material from earth, and left the majority of the dense metal behind. the moon's density is substantially less than that of earth, due to its lack of a large iron core. on earth, physical and chemical differentiation processes led to a crustal density of approximately 2700 kg / m3 compared to the 3400 kg / m3 density of the compositionally different mantle just below, and the average density of the planet as a whole is 5515 kg / m3. = =
, between two bodies or closed systems, have been determined for a process, so as to conform with the principle of conservation of energy or the first law of thermodynamics for closed systems ; this approach grew in the twentieth century, though was partly manifest in the nineteenth. = = = = thermodynamic stream of thinking = = = = in the thermodynamic stream of thinking, the specified mechanisms of heat transfer are conduction and radiation. these mechanisms presuppose recognition of temperature ; empirical temperature is enough for this purpose, though absolute temperature can also serve. in this stream of thinking, quantity of heat is defined primarily through calorimetry. though its definition of them differs from that of the mechanical stream of thinking, the empirical stream of thinking nevertheless presupposes the existence of adiabatic enclosures. it defines them through the concepts of heat and temperature. these two concepts are coordinately coherent in the sense that they arise jointly in the description of experiments of transfer of energy as heat. = = = = mechanical stream of thinking = = = = in the mechanical stream of thinking about a process of transfer of energy between two bodies or closed systems, heat transferred is defined as a residual amount of energy transferred after the energy transferred as work has been determined, assuming for the calculation the law of conservation of energy, without reference to the concept of temperature. there are five main elements of the underlying theory. the existence of states of thermodynamic equilibrium, determinable by precisely one ( called the non - deformation variable ) more variable of state than the number of independent work ( deformation ) variables. that a state of internal thermodynamic equilibrium of a body have a well defined internal energy, that is postulated by the first law of thermodynamics. the universality of the law of conservation of energy. the recognition of work as a form of energy transfer. the universal irreversibility of natural processes. the existence of adiabatic enclosures. the existence of walls permeable only to heat. axiomatic presentations of this stream of thinking vary slightly, but they intend to avoid the notions of heat and of temperature in their axioms. it is essential to this stream of thinking that heat is not presupposed as being measurable by calorimetry. it is essential to this stream of thinking that, for the specification of the thermodynamic state of a body or closed system, in addition to the variables of state called deformation variables,
low for theoretical models of seafloor spreading. the convective crustal heat transfer computed for the first time from the vent plumes was estimated to be many - fold the observed conductive heat flow at a spreading center. these observations pointed to the importance of convective heat flow at spreading centers and provided an answer to the low heat flow problem. the discovery of biological communities at low temperature warm vents at 21Β°n, populated by a benthic community the same or similar to that discovered at the galapagos spreading center, established that life forms found at the galapagos were not unique. further, the significance of discovering at the galapagos site and 21Β°n of a chemosynthetic ecosystem that was not dependent on sunlight, existed at high pressures, and was based on chemicals emitted via volcanism, provided a model for how life could have originated on earth. = = see also = = tanya atwater robert ballard jack corliss rachel haymon miriam kastner bruce p. luyendyk endeavor hydrothermal vents magic mountain ( vents offshore british columbia, canada ) rivera plate = = references = = = = further reading = = ballard, r. d. ; grassle, j. f. ( 1979 ). " incredible world of deep sea rifts ". national geographic. 156 : 680 β 705. ballard, robert d. ( 2017 - 03 - 21 ). the eternal darkness : a personal history of deep - sea exploration. hively, will ( new princeton science library ed. ). princeton, n. j. isbn 9780691175621. oclc 982214518. { { cite book } } : cs1 maint : location missing publisher ( link ) crane, kathleen. ( 2003 ). sea legs : tales of a woman oceanographer. boulder, colo. : westview press. isbn 978 - 0813340043. oclc 51553643. haymon, r. m. ( 2014 ), " hydrothermal vents at mid - ocean ridges ", reference module in earth systems and environmental sciences, elsevier, doi : 10. 1016 / b978 - 0 - 12 - 409548 - 9. 09050 - 3, isbn 9780124095489, retrieved 2019 - 06 - 27 macdonald, ken c. ; luyendyk, bruce p. ( 1981 ). " the crest of the east pacific rise ". scientific american. 244 ( 5 ) :
migration of anatectic melt flows down local pressure gradients with little or no crystallization. the network of channels through which the melt moved at this stage may be lost by compression of the melanosome, leaving isolated lenses of leucosome. the melt product gathers in an underlying channel where it becomes subject to differentiation. conduction is the principal mechanism of heat transfer in the continental crust ; where shallow layers have been exhumed or buried rapidly there is a corresponding inflection in the geothermal gradient. cooling due to surface exposure is conducted very slowly to deeper rocks so the deeper crust is slow to heat up and slow to cool. numerical models of crustal heating confirm slow cooling in the deep crust. therefore, once formed, anatectic melt can exist in the middle and lower crust for a very long period of time. it is squeezed laterally to form sills, laccolithic and lopolithic structures of mobile granulite at depths of c. 10 β 20 km. in outcrop today only stages of this process arrested during its initial rapid uplift are visible. wherever the resulting fractionated granulite rises steeply in the crust, water exits from its supercriticality phase, the granulite starts to crystallize, becomes firstly fractionated melt + crystals, then solid rock, whilst still at the conditions of temperature and pressure existing beyond 8 km. water, carbon dioxide, sulphur dioxide and other elements are exsolved under great pressure from the melt as it exits from supercritical conditions. these components rise rapidly towards the surface and contribute to formation of mineral deposits, volcanoes, mud volcanoes, geysers and hot springs. = = color - banded migmatites = = a leucosome is the lightest - colored part of migmatite. the melanosome is the darker part, and occurs between two leucosomes or, if remnants of the more or less unmodified parent rock ( mesosome ) are still present, it is arranged in rims around these remnants. when present, the mesosome is intermediate in color between leucosome and melanosome. the melanosome is a dark, mafic mineral band formed in migmatite which is melting into a eutaxitic texture ; often, this leads to the formation of granite. the melanosomes form bands with leucosomes, and in that context may be described as schlieren ( color banding ) or
migration of anatectic melt flows down local pressure gradients with little or no crystallization. the network of channels through which the melt moved at this stage may be lost by compression of the melanosome, leaving isolated lenses of leucosome. the melt product gathers in an underlying channel where it becomes subject to differentiation. conduction is the principal mechanism of heat transfer in the continental crust ; where shallow layers have been exhumed or buried rapidly there is a corresponding inflection in the geothermal gradient. cooling due to surface exposure is conducted very slowly to deeper rocks so the deeper crust is slow to heat up and slow to cool. numerical models of crustal heating confirm slow cooling in the deep crust. therefore, once formed, anatectic melt can exist in the middle and lower crust for a very long period of time. it is squeezed laterally to form sills, laccolithic and lopolithic structures of mobile granulite at depths of c. 10 β 20 km. in outcrop today only stages of this process arrested during its initial rapid uplift are visible. wherever the resulting fractionated granulite rises steeply in the crust, water exits from its supercriticality phase, the granulite starts to crystallize, becomes firstly fractionated melt + crystals, then solid rock, whilst still at the conditions of temperature and pressure existing beyond 8 km. water, carbon dioxide, sulphur dioxide and other elements are exsolved under great pressure from the melt as it exits from supercritical conditions. these components rise rapidly towards the surface and contribute to formation of mineral deposits, volcanoes, mud volcanoes, geysers and hot springs. = = color - banded migmatites = = a leucosome is the lightest - colored part of migmatite. the melanosome is the darker part, and occurs between two leucosomes or, if remnants of the more or less unmodified parent rock ( mesosome ) are still present, it is arranged in rims around these remnants. when present, the mesosome is intermediate in color between leucosome and melanosome. the melanosome is a dark, mafic mineral band formed in migmatite which is melting into a eutaxitic texture ; often, this leads to the formation of granite. the melanosomes form bands with leucosomes, and in that context may be described as schlieren ( color banding ) or
Answer:
|
a vent
| 0.3 |
Which likely could replace the sun in our solar system?
0. another star
1. the moon
2. Jupiter
3. Venus
a large collision : the pluto β charon, orcus β vanth and earth β moon systems are unusual in the solar system in that the satellite's mass is at least 1 % that of the larger body. = = future = = astronomers estimate that the current state of the solar system will not change drastically until the sun has fused almost all the hydrogen fuel in its core into helium, beginning its evolution from the main sequence of the hertzsprung β russell diagram and into its red - giant phase. the solar system will continue to evolve until then. eventually, the sun will likely expand sufficiently to overwhelm the inner planets ( mercury, venus, and possibly earth ) but not the outer planets, including jupiter and saturn. afterward, the sun would be reduced to the size of a white dwarf, and the outer planets and their moons would continue orbiting this diminutive solar remnant. this future development may be similar to the observed detection of moa - 2010 - blg - 477l b, a jupiter - sized exoplanet orbiting its host white dwarf star moa - 2010 - blg - 477l. = = = long - term stability = = = the solar system is chaotic over million - and billion - year timescales, with the orbits of the planets open to long - term variations. one notable example of this chaos is the neptune β pluto system, which lies in a 3 : 2 orbital resonance. although the resonance itself will remain stable, it becomes impossible to predict the position of pluto with any degree of accuracy more than 10 β 20 million years ( the lyapunov time ) into the future. another example is earth's axial tilt, which, due to friction raised within earth's mantle by tidal interactions with the moon ( see below ), is incomputable from some point between 1. 5 and 4. 5 billion years from now. the outer planets'orbits are chaotic over longer timescales, with a lyapunov time in the range of 2 β 230 million years. in all cases, this means that the position of a planet along its orbit ultimately becomes impossible to predict with any certainty ( so, for example, the timing of winter and summer becomes uncertain ). still, in some cases, the orbits themselves may change dramatically. such chaos manifests most strongly as changes in eccentricity, with some planets'orbits becoming significantly more β or less β elliptical. ultimately, the solar system is stable in that none of the planets are likely to col
of the sun became so great that its hydrogen began to fuse, creating an internal source of energy that countered gravitational contraction until hydrostatic equilibrium was achieved. this marked the sun's entry into the prime phase of its life, known as the main sequence. main - sequence stars derive energy from the fusion of hydrogen into helium in their cores. the sun remains a main - sequence star today. as the early solar system continued to evolve, it eventually drifted away from its siblings in the stellar nursery, and continued orbiting the milky way's center on its own. the sun likely drifted from its original orbital distance from the center of the galaxy. the chemical history of the sun suggests it may have formed as much as 3 kpc closer to the galaxy core. = = = solar system birth environment = = = like most stars, the sun likely formed not in isolation but as part of a young star cluster. there are several indications that hint at the cluster environment having had some influence over the young, still - forming solar system. for example, the decline in mass beyond neptune and the extreme eccentric - orbit of sedna have been interpreted as a signature of the solar system having been influenced by its birth environment. whether the presence of the isotopes iron - 60 and aluminium - 26 can be interpreted as a sign of a birth cluster containing massive stars is still under debate. if the sun was part of a star cluster, it might have been influenced by close flybys of other stars, the strong radiation of nearby massive stars and ejecta from supernovae occurring close by. = = = formation of the planets = = = the various planets are thought to have formed from the solar nebula, the disc - shaped cloud of gas and dust left over from the sun's formation. the currently accepted method by which the planets formed is accretion, in which the planets began as dust grains in orbit around the central protostar. through direct contact and self - organization, these grains formed into clumps up to 200 m ( 660 ft ) in diameter, which in turn collided to form larger bodies ( planetesimals ) of ~ 10 km ( 6. 2 mi ) in size. these gradually increased through further collisions, growing at the rate of centimetres per year over the course of the next few million years. the inner solar system, the region of the solar system inside 4 au, was too warm for volatile molecules like water and methane to condense, so the planetesimals that formed there could only form from compounds with high melting points
##s : r and n have been subsumed into the new c class as c - r and c - n. = = stellar classification, habitability, and the search for life = = while humans may eventually be able to colonize any kind of stellar habitat, this section will address the probability of life arising around other stars. stability, luminosity, and lifespan are all factors in stellar habitability. humans know of only one star that hosts life, the g - class sun, a star with an abundance of heavy elements and low variability in brightness. the solar system is also unlike many stellar systems in that it only contains one star ( see habitability of binary star systems ). working from these constraints and the problems of having an empirical sample set of only one, the range of stars that are predicted to be able to support life is limited by a few factors. of the main - sequence star types, stars more massive than 1. 5 times that of the sun ( spectral types o, b, and a ) age too quickly for advanced life to develop ( using earth as a guideline ). on the other extreme, dwarfs of less than half the mass of the sun ( spectral type m ) are likely to tidally lock planets within their habitable zone, along with other problems ( see habitability of red dwarf systems ). while there are many problems facing life on red dwarfs, many astronomers continue to model these systems due to their sheer numbers and longevity. for these reasons nasa's kepler mission is searching for habitable planets at nearby main - sequence stars that are less massive than spectral type a but more massive than type m β making the most probable stars to host life dwarf stars of types f, g, and k. = = see also = = astrograph β type of telescope guest star β ancient chinese name for cataclysmic variable stars spectral signature β variation of reflectance or emittance of a material with respect to wavelengths star count β bookkeeping survey of stars, survey of stars stellar dynamics β branch of astrophysics = = notes = = = = references = = = = further reading = = harre, jan - vincent ; heller, rene ( 2021 ). " digital color codes of stars ". astronomische nachrichten. 342 ( 3 ) : 578 β 587. arxiv : 2101. 06254. bibcode : 2021an.... 342.. 578h. doi : 10. 1002 / asna. 2021
##ing known values for the mass and radius of the sun, and then dividing by the known luminosity of the sun ( note that this will involve another approximation, as the power output of the sun has not always been constant ) : u r l β 1. 1 Γ 10 41 j 3. 828 Γ 10 26 w = 2. 874 Γ 10 14 s β 8 900 000 years, { \ displaystyle { \ frac { u _ { \ text { r } } } { l _ { \ odot } } } \ approx { \ frac { 1. 1 \ times 10 ^ { 41 } ~ { \ text { j } } } { 3. 828 \ times 10 ^ { 26 } ~ { \ text { w } } } } = 2. 874 \ times 10 ^ { 14 } ~ \ mathrm { s } \, \ approx 8 \, 900 \, 000 ~ { \ text { years } }, } where l { \ displaystyle l _ { \ odot } } is the luminosity of the sun. while giving enough power for considerably longer than many other physical methods, such as chemical energy, this value was clearly still not long enough due to geological and biological evidence that the earth was billions of years old. it was eventually discovered that thermonuclear energy was responsible for the power output and long lifetimes of stars. the flux of internal heat for jupiter is given by the derivative according to the time of the total energy d u r d t = β 3 g m 2 10 r 2 d r d t = β 1. 46 Γ 10 28 [ j / m ] Γ d r d t [ m / s ]. { \ displaystyle { \ frac { du _ { r } } { dt } } = { \ frac { - 3gm ^ { 2 } } { 10r ^ { 2 } } } { \ frac { dr } { dt } } = - 1. 46 \ times 10 ^ { 28 } ~ { \ text { [ j / m ] } } ~ \ times { \ frac { dr } { dt } } ~ { \ text { [ m / s ] } }. } with a shrinking of β 1 m m y r = β 0. 001 m y r = β 3. 17 Γ 10 β 11 m s { \ textstyle - 1 \ mathrm { \ frac { ~ mm } { yr } } = - 0. 001
of the sun, this would not immediately be apparent. advances in helioseismology observations made it possible to infer the interior temperatures of the sun ; these results agreed with the well established standard solar model. detailed observations of the neutrino spectrum from more advanced neutrino observatories produced results which no adjustment of the solar model could accommodate : while the overall lower neutrino flux ( which the homestake experiment results found ) required a reduction in the solar core temperature, details in the energy spectrum of the neutrinos required a higher core temperature. this happens because different nuclear reactions, whose rates have different dependence upon the temperature, produce neutrinos with different energy. any adjustment to the solar model worsened at least one aspect of the discrepancies. = = resolution = = the solar neutrino problem was resolved with an improved understanding of the properties of neutrinos. according to the standard model of particle physics, there are three flavors of neutrinos : electron neutrinos, muon neutrinos, and tau neutrinos. electron neutrinos are the ones produced in the sun and the ones detected by the above - mentioned experiments, in particular the chlorine - detector homestake mine experiment. through the 1970s, it was widely believed that neutrinos were massless and their flavors were invariant. however, in 1968 pontecorvo proposed that if neutrinos had mass, then they could change from one flavor to another. thus, the " missing " solar neutrinos could be electron neutrinos which changed into other flavors along the way to earth, rendering them invisible to the detectors in the homestake mine and contemporary neutrino observatories. the supernova 1987a indicated that neutrinos might have mass because of the difference in time of arrival of the neutrinos detected at kamiokande and imb. however, because very few neutrino events were detected, it was difficult to draw any conclusions with certainty. if kamiokande and imb had high - precision timers to measure the travel time of the neutrino burst through the earth, they could have more definitively established whether or not neutrinos had mass. if neutrinos were massless, they would travel at the speed of light ; if they had mass, they would travel at velocities slightly less than that of light. since the detectors were not intended for super
Answer:
|
another star
| null |
Which likely could replace the sun in our solar system?
0. another star
1. the moon
2. Jupiter
3. Venus
a large collision : the pluto β charon, orcus β vanth and earth β moon systems are unusual in the solar system in that the satellite's mass is at least 1 % that of the larger body. = = future = = astronomers estimate that the current state of the solar system will not change drastically until the sun has fused almost all the hydrogen fuel in its core into helium, beginning its evolution from the main sequence of the hertzsprung β russell diagram and into its red - giant phase. the solar system will continue to evolve until then. eventually, the sun will likely expand sufficiently to overwhelm the inner planets ( mercury, venus, and possibly earth ) but not the outer planets, including jupiter and saturn. afterward, the sun would be reduced to the size of a white dwarf, and the outer planets and their moons would continue orbiting this diminutive solar remnant. this future development may be similar to the observed detection of moa - 2010 - blg - 477l b, a jupiter - sized exoplanet orbiting its host white dwarf star moa - 2010 - blg - 477l. = = = long - term stability = = = the solar system is chaotic over million - and billion - year timescales, with the orbits of the planets open to long - term variations. one notable example of this chaos is the neptune β pluto system, which lies in a 3 : 2 orbital resonance. although the resonance itself will remain stable, it becomes impossible to predict the position of pluto with any degree of accuracy more than 10 β 20 million years ( the lyapunov time ) into the future. another example is earth's axial tilt, which, due to friction raised within earth's mantle by tidal interactions with the moon ( see below ), is incomputable from some point between 1. 5 and 4. 5 billion years from now. the outer planets'orbits are chaotic over longer timescales, with a lyapunov time in the range of 2 β 230 million years. in all cases, this means that the position of a planet along its orbit ultimately becomes impossible to predict with any certainty ( so, for example, the timing of winter and summer becomes uncertain ). still, in some cases, the orbits themselves may change dramatically. such chaos manifests most strongly as changes in eccentricity, with some planets'orbits becoming significantly more β or less β elliptical. ultimately, the solar system is stable in that none of the planets are likely to col
of the sun became so great that its hydrogen began to fuse, creating an internal source of energy that countered gravitational contraction until hydrostatic equilibrium was achieved. this marked the sun's entry into the prime phase of its life, known as the main sequence. main - sequence stars derive energy from the fusion of hydrogen into helium in their cores. the sun remains a main - sequence star today. as the early solar system continued to evolve, it eventually drifted away from its siblings in the stellar nursery, and continued orbiting the milky way's center on its own. the sun likely drifted from its original orbital distance from the center of the galaxy. the chemical history of the sun suggests it may have formed as much as 3 kpc closer to the galaxy core. = = = solar system birth environment = = = like most stars, the sun likely formed not in isolation but as part of a young star cluster. there are several indications that hint at the cluster environment having had some influence over the young, still - forming solar system. for example, the decline in mass beyond neptune and the extreme eccentric - orbit of sedna have been interpreted as a signature of the solar system having been influenced by its birth environment. whether the presence of the isotopes iron - 60 and aluminium - 26 can be interpreted as a sign of a birth cluster containing massive stars is still under debate. if the sun was part of a star cluster, it might have been influenced by close flybys of other stars, the strong radiation of nearby massive stars and ejecta from supernovae occurring close by. = = = formation of the planets = = = the various planets are thought to have formed from the solar nebula, the disc - shaped cloud of gas and dust left over from the sun's formation. the currently accepted method by which the planets formed is accretion, in which the planets began as dust grains in orbit around the central protostar. through direct contact and self - organization, these grains formed into clumps up to 200 m ( 660 ft ) in diameter, which in turn collided to form larger bodies ( planetesimals ) of ~ 10 km ( 6. 2 mi ) in size. these gradually increased through further collisions, growing at the rate of centimetres per year over the course of the next few million years. the inner solar system, the region of the solar system inside 4 au, was too warm for volatile molecules like water and methane to condense, so the planetesimals that formed there could only form from compounds with high melting points
##s : r and n have been subsumed into the new c class as c - r and c - n. = = stellar classification, habitability, and the search for life = = while humans may eventually be able to colonize any kind of stellar habitat, this section will address the probability of life arising around other stars. stability, luminosity, and lifespan are all factors in stellar habitability. humans know of only one star that hosts life, the g - class sun, a star with an abundance of heavy elements and low variability in brightness. the solar system is also unlike many stellar systems in that it only contains one star ( see habitability of binary star systems ). working from these constraints and the problems of having an empirical sample set of only one, the range of stars that are predicted to be able to support life is limited by a few factors. of the main - sequence star types, stars more massive than 1. 5 times that of the sun ( spectral types o, b, and a ) age too quickly for advanced life to develop ( using earth as a guideline ). on the other extreme, dwarfs of less than half the mass of the sun ( spectral type m ) are likely to tidally lock planets within their habitable zone, along with other problems ( see habitability of red dwarf systems ). while there are many problems facing life on red dwarfs, many astronomers continue to model these systems due to their sheer numbers and longevity. for these reasons nasa's kepler mission is searching for habitable planets at nearby main - sequence stars that are less massive than spectral type a but more massive than type m β making the most probable stars to host life dwarf stars of types f, g, and k. = = see also = = astrograph β type of telescope guest star β ancient chinese name for cataclysmic variable stars spectral signature β variation of reflectance or emittance of a material with respect to wavelengths star count β bookkeeping survey of stars, survey of stars stellar dynamics β branch of astrophysics = = notes = = = = references = = = = further reading = = harre, jan - vincent ; heller, rene ( 2021 ). " digital color codes of stars ". astronomische nachrichten. 342 ( 3 ) : 578 β 587. arxiv : 2101. 06254. bibcode : 2021an.... 342.. 578h. doi : 10. 1002 / asna. 2021
##ing known values for the mass and radius of the sun, and then dividing by the known luminosity of the sun ( note that this will involve another approximation, as the power output of the sun has not always been constant ) : u r l β 1. 1 Γ 10 41 j 3. 828 Γ 10 26 w = 2. 874 Γ 10 14 s β 8 900 000 years, { \ displaystyle { \ frac { u _ { \ text { r } } } { l _ { \ odot } } } \ approx { \ frac { 1. 1 \ times 10 ^ { 41 } ~ { \ text { j } } } { 3. 828 \ times 10 ^ { 26 } ~ { \ text { w } } } } = 2. 874 \ times 10 ^ { 14 } ~ \ mathrm { s } \, \ approx 8 \, 900 \, 000 ~ { \ text { years } }, } where l { \ displaystyle l _ { \ odot } } is the luminosity of the sun. while giving enough power for considerably longer than many other physical methods, such as chemical energy, this value was clearly still not long enough due to geological and biological evidence that the earth was billions of years old. it was eventually discovered that thermonuclear energy was responsible for the power output and long lifetimes of stars. the flux of internal heat for jupiter is given by the derivative according to the time of the total energy d u r d t = β 3 g m 2 10 r 2 d r d t = β 1. 46 Γ 10 28 [ j / m ] Γ d r d t [ m / s ]. { \ displaystyle { \ frac { du _ { r } } { dt } } = { \ frac { - 3gm ^ { 2 } } { 10r ^ { 2 } } } { \ frac { dr } { dt } } = - 1. 46 \ times 10 ^ { 28 } ~ { \ text { [ j / m ] } } ~ \ times { \ frac { dr } { dt } } ~ { \ text { [ m / s ] } }. } with a shrinking of β 1 m m y r = β 0. 001 m y r = β 3. 17 Γ 10 β 11 m s { \ textstyle - 1 \ mathrm { \ frac { ~ mm } { yr } } = - 0. 001
of the sun, this would not immediately be apparent. advances in helioseismology observations made it possible to infer the interior temperatures of the sun ; these results agreed with the well established standard solar model. detailed observations of the neutrino spectrum from more advanced neutrino observatories produced results which no adjustment of the solar model could accommodate : while the overall lower neutrino flux ( which the homestake experiment results found ) required a reduction in the solar core temperature, details in the energy spectrum of the neutrinos required a higher core temperature. this happens because different nuclear reactions, whose rates have different dependence upon the temperature, produce neutrinos with different energy. any adjustment to the solar model worsened at least one aspect of the discrepancies. = = resolution = = the solar neutrino problem was resolved with an improved understanding of the properties of neutrinos. according to the standard model of particle physics, there are three flavors of neutrinos : electron neutrinos, muon neutrinos, and tau neutrinos. electron neutrinos are the ones produced in the sun and the ones detected by the above - mentioned experiments, in particular the chlorine - detector homestake mine experiment. through the 1970s, it was widely believed that neutrinos were massless and their flavors were invariant. however, in 1968 pontecorvo proposed that if neutrinos had mass, then they could change from one flavor to another. thus, the " missing " solar neutrinos could be electron neutrinos which changed into other flavors along the way to earth, rendering them invisible to the detectors in the homestake mine and contemporary neutrino observatories. the supernova 1987a indicated that neutrinos might have mass because of the difference in time of arrival of the neutrinos detected at kamiokande and imb. however, because very few neutrino events were detected, it was difficult to draw any conclusions with certainty. if kamiokande and imb had high - precision timers to measure the travel time of the neutrino burst through the earth, they could have more definitively established whether or not neutrinos had mass. if neutrinos were massless, they would travel at the speed of light ; if they had mass, they would travel at velocities slightly less than that of light. since the detectors were not intended for super
Answer:
|
Venus
| 0.3 |
Plate shifting likely directly created
0. oxygen
1. the Alps
2. human life
3. ocean spray
the ozone layer, which shielded away harmful ionizing ultraviolet radiation that otherwise would have photodissociated away surface water and rendered life impossible on land and the ocean surface. in contrast to the hypothesized early reducing atmosphere, evidence exists that hadean atmospheric oxygen levels were similar to today's. these results suggest prebiotic building blocks were delivered from elsewhere in the galaxy. the results, however, do not contradict existing theories on life's journey from anaerobic to aerobic organisms. the results quantify the nature of gas molecules containing carbon, hydrogen, and sulphur in the earliest atmosphere, but they shed no light on the much later rise of free oxygen in the air. = = see also = = atmosphere of earth great oxidation event β paleoproterozoic surge in atmospheric oxygen paleoclimatology β study of changes in ancient climate paleoatmosphere β ancient atmosphere, particularly of earth, in the geological past redox β chemical reaction with oxidation state changes = = notes = =
and a likely increase in the amount of sulfate in sea water. in the paleoproterozoic the sulfate in seawater had increased to an amount greater than in the archean, but was still lower than present day values. the sulfate levels in the proterozoic also act as proxies for atmospheric oxygen because sulfate is produced mostly through weathering of the continents in the presence of oxygen. the low levels in the proterozoic simply imply that levels of atmospheric oxygen fell between the abundances of the phanerozoic and the deficiencies of the archean. 750 million years ago ( ma ) there is a renewed deposition of bif which marks a significant change in ocean chemistry. this was likely due to snowball earth episodes where the entire globe including the oceans was covered in a layer of ice cutting off oxygenation. in the late neoproterozoic high carbon burial rates increased the atmospheric oxygen level to > 10 % of its present - day value. in the latest neoproterozoic another major oxidizing event occurred on earth's surface that resulted in an oxic deep ocean and possibly allowed for the appearance of multicellular life. during the last 600 million years, seawater so4 has generally varied between + 10 β° and + 30 β° in Ξ΄34s, with an average value close to that of today. notably changes in seawater Ξ΄34s occurred during extinction and climatic events during this time. over a shorter time scale ( ten million years ) changes in the sulfur cycle are easier to observe and can be even better constrained with oxygen isotopes. oxygen is continually incorporated into the sulfur cycle through sulfate oxidation and then released when that sulfate is reduced once again. since different sulfate sources within the ocean have distinct oxygen isotopic values it may be possible to use oxygen to trace the sulfur cycle. biological sulfate reduction preferentially selects lighter oxygen isotopes for the same reason that lighter sulfur isotopes are preferred. by studying oxygen isotopes in ocean sediments over the last 10 million years were able to better constrain the sulfur concentrations in sea water through that same time. they found that the sea level changes due to pliocene and pleistocene glacial cycles changed the area of continental shelves which then disrupted the sulfur processing, lowering the concentration of sulfate in the sea water. this was a drastic change as compared to preglacial times before 2 million years ago. = = the great oxidation event and sulfur isotope mass - independent fractionation = = the great oxygenation event ( goe ) is characterized
plate is nowhere being subducted, yet it is in motion. likewise the african, eurasian and antarctic plates. ridge push is thought responsible for the motion of these plates. the subducting slabs around the pacific ring of fire cool down the earth and its core - mantle boundary. around the african plate upwelling mantle plumes from the core - mantle boundary produce rifting including the african and ethiopian rift valleys. = = see also = = mid - ocean ridge seafloor spreading ridge push = = references = = = = further reading = = schellart, w. p. ; stegman, d. r. ; farrington, r. j. ; freeman, j. ; moresi, l. ( 16 july 2010 ). " cenozoic tectonics of western north america controlled by evolving width of farallon slab ". science. 329 ( 5989 ) : 316 β 319. bibcode : 2010sci... 329.. 316s. doi : 10. 1126 / science. 1190366. pmid 20647465. s2cid 12044269. " breakthrough achieved in explaining why tectonic plates move the way they do ". sciencedaily. 17 july 2010. clinton p. conrad ; susan bilek ; carolina lithgow - bertelloni ( 2004 ). " great earthquakes and slab pull : interaction between seismic coupling and plate - slab coupling " ( pdf ). earth and planetary science letters. 218 ( 1 β 2 ) : 109 β 122. bibcode : 2004e & psl. 218.. 109c. citeseerx 10. 1. 1. 506. 2266. doi : 10. 1016 / s0012 - 821x ( 03 ) 00643 - 5. archived from the original ( pdf ) on 2011 - 06 - 13. retrieved 2010 - 11 - 18.
found microbial communities apparently based on the products of reactions between water and the constituents of rocks. these communities have not been studied much, but may be an important part of the global carbon cycle. rock in mines two miles deep also harbour microbes ; these live on minute traces of hydrogen produced in slow oxidizing reactions inside the rock. these metabolic reactions allow life to exist in places with no oxygen or light, an environment that had previously been thought to be devoid of life. the intertidal zone and the photic zone in the oceans are relatively familiar habitat types. however the vast bulk of the ocean is inhospitable to air - breathing humans, with scuba divers limited to the upper 50 m ( 160 ft ) or so. the lower limit for photosynthesis is 100 to 200 m ( 330 to 660 ft ) and below that depth the prevailing conditions include total darkness, high pressure, little oxygen ( in some places ), scarce food resources and extreme cold. this habitat is very challenging to research, and as well as being little - studied, it is vast, with 79 % of the earth's biosphere being at depths greater than 1, 000 m ( 3, 300 ft ). with no plant life, the animals in this zone are either detritivores, reliant on food drifting down from surface layers, or they are predators, feeding on each other. some organisms are pelagic, swimming or drifting in mid - ocean, while others are benthic, living on or near the seabed. their growth rates and metabolisms tend to be slow, their eyes may be very large to detect what little illumination there is, or they may be blind and rely on other sensory inputs. a number of deep sea creatures are bioluminescent ; this serves a variety of functions including predation, protection and social recognition. in general, the bodies of animals living at great depths are adapted to high pressure environments by having pressure - resistant biomolecules and small organic molecules present in their cells known as piezolytes, which give the proteins the flexibility they need. there are also unsaturated fats in their membranes which prevent them from solidifying at low temperatures. hydrothermal vents were first discovered in the ocean depths in 1977. they result from seawater becoming heated after seeping through cracks to places where hot magma is close to the seabed. the under - water hot springs may gush forth at temperatures of over 340 Β°c ( 640 Β°f ) and support unique communities of organisms in their
coeval black shales on open - ocean pacific plateaus and shelf seas around the world. there are suggestions, again from the atlantic, that a shift in oceanic circulation was responsible, where warm, salty waters at low latitudes became hypersaline and sank to form an intermediate layer, at 500 to 1, 000 m ( 1, 640 to 3, 281 ft ) depth, with a temperature of 20 to 25 Β°c ( 68 to 77 Β°f ). the second hypothesis suggests that oceanic anoxic events record a major change in the fertility of the oceans that resulted in an increase in organic - walled plankton ( including bacteria ) at the expense of calcareous plankton such as coccoliths and foraminifera. such an accelerated flux of organic matter would have expanded and intensified the oxygen minimum zone, further enhancing the amount of organic carbon entering the sedimentary record. essentially this mechanism assumes a major increase in the availability of dissolved nutrients such as nitrate, phosphate and possibly iron to the phytoplankton population living in the illuminated layers of the oceans. for such an increase to occur would have required an accelerated influx of land - derived nutrients coupled with vigorous upwelling, requiring major climate change on a global scale. geochemical data from oxygen - isotope ratios in carbonate sediments and fossils, and magnesium / calcium ratios in fossils, indicate that all major oceanic anoxic events were associated with thermal maxima, making it likely that global weathering rates, and nutrient flux to the oceans, were increased during these intervals. indeed, the reduced solubility of oxygen would lead to phosphate release, further nourishing the ocean and fuelling high productivity, hence a high oxygen demand β sustaining the event through a positive feedback. another way to explain anoxic events is that the earth releases a huge volume of carbon dioxide during an interval of intense volcanism ; global temperatures rise due to the greenhouse effect ; global weathering rates and fluvial nutrient flux increase ; organic productivity in the oceans increases ; organic - carbon burial in the oceans increases ( oae begins ) ; carbon dioxide is drawn down due to both burial of organic matter and weathering of silicate rocks ( inverse greenhouse effect ) ; global temperatures fall, and the ocean β atmosphere system returns to equilibrium ( oae ends ). in this way, an oceanic anoxic event can be viewed as the earth's response to the injection of excess carbon dioxide into the atmosphere and hydrosphere. one test of this notion is to look at the age of large igneous
Answer:
|
the Alps
| null |
Plate shifting likely directly created
0. oxygen
1. the Alps
2. human life
3. ocean spray
the ozone layer, which shielded away harmful ionizing ultraviolet radiation that otherwise would have photodissociated away surface water and rendered life impossible on land and the ocean surface. in contrast to the hypothesized early reducing atmosphere, evidence exists that hadean atmospheric oxygen levels were similar to today's. these results suggest prebiotic building blocks were delivered from elsewhere in the galaxy. the results, however, do not contradict existing theories on life's journey from anaerobic to aerobic organisms. the results quantify the nature of gas molecules containing carbon, hydrogen, and sulphur in the earliest atmosphere, but they shed no light on the much later rise of free oxygen in the air. = = see also = = atmosphere of earth great oxidation event β paleoproterozoic surge in atmospheric oxygen paleoclimatology β study of changes in ancient climate paleoatmosphere β ancient atmosphere, particularly of earth, in the geological past redox β chemical reaction with oxidation state changes = = notes = =
and a likely increase in the amount of sulfate in sea water. in the paleoproterozoic the sulfate in seawater had increased to an amount greater than in the archean, but was still lower than present day values. the sulfate levels in the proterozoic also act as proxies for atmospheric oxygen because sulfate is produced mostly through weathering of the continents in the presence of oxygen. the low levels in the proterozoic simply imply that levels of atmospheric oxygen fell between the abundances of the phanerozoic and the deficiencies of the archean. 750 million years ago ( ma ) there is a renewed deposition of bif which marks a significant change in ocean chemistry. this was likely due to snowball earth episodes where the entire globe including the oceans was covered in a layer of ice cutting off oxygenation. in the late neoproterozoic high carbon burial rates increased the atmospheric oxygen level to > 10 % of its present - day value. in the latest neoproterozoic another major oxidizing event occurred on earth's surface that resulted in an oxic deep ocean and possibly allowed for the appearance of multicellular life. during the last 600 million years, seawater so4 has generally varied between + 10 β° and + 30 β° in Ξ΄34s, with an average value close to that of today. notably changes in seawater Ξ΄34s occurred during extinction and climatic events during this time. over a shorter time scale ( ten million years ) changes in the sulfur cycle are easier to observe and can be even better constrained with oxygen isotopes. oxygen is continually incorporated into the sulfur cycle through sulfate oxidation and then released when that sulfate is reduced once again. since different sulfate sources within the ocean have distinct oxygen isotopic values it may be possible to use oxygen to trace the sulfur cycle. biological sulfate reduction preferentially selects lighter oxygen isotopes for the same reason that lighter sulfur isotopes are preferred. by studying oxygen isotopes in ocean sediments over the last 10 million years were able to better constrain the sulfur concentrations in sea water through that same time. they found that the sea level changes due to pliocene and pleistocene glacial cycles changed the area of continental shelves which then disrupted the sulfur processing, lowering the concentration of sulfate in the sea water. this was a drastic change as compared to preglacial times before 2 million years ago. = = the great oxidation event and sulfur isotope mass - independent fractionation = = the great oxygenation event ( goe ) is characterized
plate is nowhere being subducted, yet it is in motion. likewise the african, eurasian and antarctic plates. ridge push is thought responsible for the motion of these plates. the subducting slabs around the pacific ring of fire cool down the earth and its core - mantle boundary. around the african plate upwelling mantle plumes from the core - mantle boundary produce rifting including the african and ethiopian rift valleys. = = see also = = mid - ocean ridge seafloor spreading ridge push = = references = = = = further reading = = schellart, w. p. ; stegman, d. r. ; farrington, r. j. ; freeman, j. ; moresi, l. ( 16 july 2010 ). " cenozoic tectonics of western north america controlled by evolving width of farallon slab ". science. 329 ( 5989 ) : 316 β 319. bibcode : 2010sci... 329.. 316s. doi : 10. 1126 / science. 1190366. pmid 20647465. s2cid 12044269. " breakthrough achieved in explaining why tectonic plates move the way they do ". sciencedaily. 17 july 2010. clinton p. conrad ; susan bilek ; carolina lithgow - bertelloni ( 2004 ). " great earthquakes and slab pull : interaction between seismic coupling and plate - slab coupling " ( pdf ). earth and planetary science letters. 218 ( 1 β 2 ) : 109 β 122. bibcode : 2004e & psl. 218.. 109c. citeseerx 10. 1. 1. 506. 2266. doi : 10. 1016 / s0012 - 821x ( 03 ) 00643 - 5. archived from the original ( pdf ) on 2011 - 06 - 13. retrieved 2010 - 11 - 18.
found microbial communities apparently based on the products of reactions between water and the constituents of rocks. these communities have not been studied much, but may be an important part of the global carbon cycle. rock in mines two miles deep also harbour microbes ; these live on minute traces of hydrogen produced in slow oxidizing reactions inside the rock. these metabolic reactions allow life to exist in places with no oxygen or light, an environment that had previously been thought to be devoid of life. the intertidal zone and the photic zone in the oceans are relatively familiar habitat types. however the vast bulk of the ocean is inhospitable to air - breathing humans, with scuba divers limited to the upper 50 m ( 160 ft ) or so. the lower limit for photosynthesis is 100 to 200 m ( 330 to 660 ft ) and below that depth the prevailing conditions include total darkness, high pressure, little oxygen ( in some places ), scarce food resources and extreme cold. this habitat is very challenging to research, and as well as being little - studied, it is vast, with 79 % of the earth's biosphere being at depths greater than 1, 000 m ( 3, 300 ft ). with no plant life, the animals in this zone are either detritivores, reliant on food drifting down from surface layers, or they are predators, feeding on each other. some organisms are pelagic, swimming or drifting in mid - ocean, while others are benthic, living on or near the seabed. their growth rates and metabolisms tend to be slow, their eyes may be very large to detect what little illumination there is, or they may be blind and rely on other sensory inputs. a number of deep sea creatures are bioluminescent ; this serves a variety of functions including predation, protection and social recognition. in general, the bodies of animals living at great depths are adapted to high pressure environments by having pressure - resistant biomolecules and small organic molecules present in their cells known as piezolytes, which give the proteins the flexibility they need. there are also unsaturated fats in their membranes which prevent them from solidifying at low temperatures. hydrothermal vents were first discovered in the ocean depths in 1977. they result from seawater becoming heated after seeping through cracks to places where hot magma is close to the seabed. the under - water hot springs may gush forth at temperatures of over 340 Β°c ( 640 Β°f ) and support unique communities of organisms in their
coeval black shales on open - ocean pacific plateaus and shelf seas around the world. there are suggestions, again from the atlantic, that a shift in oceanic circulation was responsible, where warm, salty waters at low latitudes became hypersaline and sank to form an intermediate layer, at 500 to 1, 000 m ( 1, 640 to 3, 281 ft ) depth, with a temperature of 20 to 25 Β°c ( 68 to 77 Β°f ). the second hypothesis suggests that oceanic anoxic events record a major change in the fertility of the oceans that resulted in an increase in organic - walled plankton ( including bacteria ) at the expense of calcareous plankton such as coccoliths and foraminifera. such an accelerated flux of organic matter would have expanded and intensified the oxygen minimum zone, further enhancing the amount of organic carbon entering the sedimentary record. essentially this mechanism assumes a major increase in the availability of dissolved nutrients such as nitrate, phosphate and possibly iron to the phytoplankton population living in the illuminated layers of the oceans. for such an increase to occur would have required an accelerated influx of land - derived nutrients coupled with vigorous upwelling, requiring major climate change on a global scale. geochemical data from oxygen - isotope ratios in carbonate sediments and fossils, and magnesium / calcium ratios in fossils, indicate that all major oceanic anoxic events were associated with thermal maxima, making it likely that global weathering rates, and nutrient flux to the oceans, were increased during these intervals. indeed, the reduced solubility of oxygen would lead to phosphate release, further nourishing the ocean and fuelling high productivity, hence a high oxygen demand β sustaining the event through a positive feedback. another way to explain anoxic events is that the earth releases a huge volume of carbon dioxide during an interval of intense volcanism ; global temperatures rise due to the greenhouse effect ; global weathering rates and fluvial nutrient flux increase ; organic productivity in the oceans increases ; organic - carbon burial in the oceans increases ( oae begins ) ; carbon dioxide is drawn down due to both burial of organic matter and weathering of silicate rocks ( inverse greenhouse effect ) ; global temperatures fall, and the ocean β atmosphere system returns to equilibrium ( oae ends ). in this way, an oceanic anoxic event can be viewed as the earth's response to the injection of excess carbon dioxide into the atmosphere and hydrosphere. one test of this notion is to look at the age of large igneous
Answer:
|
human life
| 0.3 |
the alps were formed by rock what?
0. growing
1. melting
2. erupting
3. creasing
solution, eventually creating cumulates. however, when this is interrupted by sudden eruption of the melt as lava, or when the density of the crystals and remaining melt remains similar, they become entrapped in the final rock. this can also occur when the chemical composition of the remaining melt is close to the eutectic point as it cools, resulting in multiple different minerals solidifying at once and filling the remaining space simultaneously, limiting their size and shape. = = references = =
, there are no traces of oceanic crust. the eclogites are seen as being from intra - continental gabbros, indicating an intracontinental subduction. kurtz and fritz ( 2003 ) propose that the eo - alpine orogeny might have been a two - stage cycle. the first one involved subduction and closure of the meliata ocean ( late jurassic ) and the formation of the northern calcareous alps ( early cretaceous ). the second one involved southward magmatic underplating of the continental margin of the adriatic plate and imbrication of the austroalpine basements which underwent metamorphism. this increased from greenschist - facies in the northern parts to amphibolite and eclogite facies in its southernmost parts. the origin of the second phase was probably rifting, crustal extension and crustal thinning in the permian accompanied by magmatic underplating in the internal parts of the orogen. heating of the crust by the latter created high temperature metamorphism in some rocks. with later cooling, the crust thickened again. it became gravitationally unstable causing the onset of subduction inside the continent. the high - pressure metamorphic rocks were exhumed in the late cretaceous through a detachment fault in the lower crust. on the basis of an analysis of detrital chrome spinel grains found southwest of salzburg ( in the hallstatt melange area of the saalach zone, western central northern calcareous alps ), gawlick et al. ( 2015 ) propose that the eo - alpine orogeny stated earlier than the usually indicated timeframe ( early cretaceous ). these authors argue that their study indicates that in the southern northern calcareous alps ophiolite obduction occurred earlier, in the middle to early late jurassic. this obducted ophiolite stack erosion started in the kimmeridgian ( late jurassic ) and lasted until the aptian ( late early cretaceous ). erosion was slowed down by a kimmeridgian to earliest cretaceous carbonate platform that evolved on top of the nappe stack with the obducted ophiolites. it protected the ophiolites against erosion. afterwards, the ophiolites were quickly eroded. = = lateral escape = = lateral escape or extrusion refers to the horizontal ( sideways ) movement of a landmass. it can be sinistral ( left - lateral ) or dextral ( right β lateral ). the sideways movement is caused by a thrust. in the case
this article discusses how rocks are formed. there are also articles on physical rock formations, rock layerings ( strata ), and the formal naming of geologic formations. terrestrial rocks are formed by three main mechanisms : sedimentary rocks are formed through the gradual accumulation of sediments : for example, sand on a beach or mud on a river bed. as the sediments are buried they get compacted as more and more material is deposited on top. eventually the sediments will become so dense that they would essentially form a rock. this process is known as lithification. igneous rocks have crystallised from a melt or magma. the melt is made up of various components of pre - existing rocks which have been subjected to melting either at subduction zones or within the earth's mantle. the melt is hot and so passes upward through cooler country rock. as it moves, it cools and various rock types will form through a process known as fractional crystallisation. igneous rocks can be seen at mid - ocean ridges, areas of island arc volcanism or in intra - plate hotspots. metamorphic rocks once existed as igneous or sedimentary rocks, but have been subjected to varying degrees of pressure and heat within the earth's crust. the processes involved will change the composition and fabric of the rock and their original nature is often hard to distinguish. metamorphic rocks are typically found in areas of mountain building. rock can also form in the absence of a substantial pressure gradient as material that condensed from a protoplanetary disk, without ever undergoing any transformations in the interior of a large object such as a planet or moon. astrophysicists classify this as a fourth type of rock : primitive rock. this type is common in asteroids and meteorites. : 145 = = rock formation = = = = = 19th - century efforts to synthesize rocks = = = the synthetic investigation of rocks proceeds by experimental work that attempts to reproduce different rock types and to elucidate their origins and structures. in many cases no experiment is necessary. every stage in the origin of clays, sands and gravels can be seen in process around us, but where these have been converted into coherent shales, sandstone and conglomerates, and still more where they have experienced some degree of metamorphism, there are many obscure points about their history upon which experiment may yet throw light. attempts have been made to reproduce igneous rocks, by fusion of mixtures of crushed minerals or of chemicals in specially contrived furnaces. the earliest researches of this sort are
glaciovolcanism is volcanism and related phenomena associated with glacial ice. the ice commonly constrains the erupted material and melts to create meltwater. considerable melting of glacial ice can create massive lahars and glacial outburst floods known as jokulhlaups. = = general = = three forms of glaciovolcanism are known. subglacial eruptions occur when a volcano erupts under ice. such activity can produce landforms such as tuyas and subglacial mounds. ice - marginal volcanism takes place when material from a subaerial eruption makes lateral contact with ice ; ice - marginal lava flows are a product of this phenomenon. supraglacial eruptions deposit ejecta onto the surface of an ice sheet. world regions identified for possible glaciovolcanic activity include alaska, and western parts of canada, southern chile, argentina, iceland, and a couple of regions along antarctica's coast, such as the antarctic peninsula and the ross ice shelf. volcanologist bill mcguire noted in 2014, we see evidence of the earth β waking up β specifically in relation to seismic activity in areas of alaska where dramatic ice loss ( up to 1km vertical thickness ) has occurred over the last 100 years, and also in relation to the correlation in many high mountains terrains of increased landslide occurrence and heatwaves. there is no unequivocal evidence for a specific volcanic response, unless the high level of recent activity at the icelandic volcanoes is a reflection of unloading due to melting of the vatnajokull ice cap. certainly this whole region is uplifting by a few centimetres a year, so such a suggestion would not be completely unreasonable, even if we don β t ( yet? ) have any hard evidence. = = examples = = isostatic rebound in response to glacier retreat ( unloading ), increase in local salinity ( i. e., Ξ΄18osw ), have been attributed to increased volcanic activity at the onset of bΓΈlling β allerΓΈd, are associated with the interval of intense volcanic activity, hinting at an interaction between climate and volcanism - enhanced short - term melting of glaciers, possibly via albedo changes from particle fallout on glacier surfaces. = = see also = = pine island glacier = = references = =
study of the composition, structure, physical properties, dynamics, and history of earth materials, and the processes by which they are formed, moved, and changed. the field is a major academic discipline, and is also important for mineral and hydrocarbon extraction, knowledge about and mitigation of natural hazards, some geotechnical engineering fields, and understanding past climates and environments. = = = = geological evolution = = = = the geology of an area evolves through time as rock units are deposited and inserted and deformational processes change their shapes and locations. rock units are first emplaced either by deposition onto the surface or intrude into the overlying rock. deposition can occur when sediments settle onto the surface of the earth and later lithify into sedimentary rock, or when as volcanic material such as volcanic ash or lava flows, blanket the surface. igneous intrusions such as batholiths, laccoliths, dikes, and sills, push upwards into the overlying rock, and crystallize as they intrude. after the initial sequence of rocks has been deposited, the rock units can be deformed and / or metamorphosed. deformation typically occurs as a result of horizontal shortening, horizontal extension, or side - to - side ( strike - slip ) motion. these structural regimes broadly relate to convergent boundaries, divergent boundaries, and transform boundaries, respectively, between tectonic plates. = = = historical perspective = = = earth is estimated to have formed 4. 54 billion years ago from the solar nebula, along with the sun and other planets. the moon formed roughly 20 million years later. initially molten, the outer layer of the earth cooled, resulting in the solid crust. outgassing and volcanic activity produced the primordial atmosphere. condensing water vapor, most or all of which came from ice delivered by comets, produced the oceans and other water sources. the highly energetic chemistry is believed to have produced a self - replicating molecule around 4 billion years ago. continents formed, then broke up and reformed as the surface of earth reshaped over hundreds of millions of years, occasionally combining to make a supercontinent. roughly 750 million years ago, the earliest known supercontinent rodinia, began to break apart. the continents later recombined to form pannotia which broke apart about 540 million years ago, then finally pangaea, which broke apart about 180 million years ago. during the neoproterozoic era, freezing temperatures covered much
Answer:
|
creasing
| null |
the alps were formed by rock what?
0. growing
1. melting
2. erupting
3. creasing
solution, eventually creating cumulates. however, when this is interrupted by sudden eruption of the melt as lava, or when the density of the crystals and remaining melt remains similar, they become entrapped in the final rock. this can also occur when the chemical composition of the remaining melt is close to the eutectic point as it cools, resulting in multiple different minerals solidifying at once and filling the remaining space simultaneously, limiting their size and shape. = = references = =
, there are no traces of oceanic crust. the eclogites are seen as being from intra - continental gabbros, indicating an intracontinental subduction. kurtz and fritz ( 2003 ) propose that the eo - alpine orogeny might have been a two - stage cycle. the first one involved subduction and closure of the meliata ocean ( late jurassic ) and the formation of the northern calcareous alps ( early cretaceous ). the second one involved southward magmatic underplating of the continental margin of the adriatic plate and imbrication of the austroalpine basements which underwent metamorphism. this increased from greenschist - facies in the northern parts to amphibolite and eclogite facies in its southernmost parts. the origin of the second phase was probably rifting, crustal extension and crustal thinning in the permian accompanied by magmatic underplating in the internal parts of the orogen. heating of the crust by the latter created high temperature metamorphism in some rocks. with later cooling, the crust thickened again. it became gravitationally unstable causing the onset of subduction inside the continent. the high - pressure metamorphic rocks were exhumed in the late cretaceous through a detachment fault in the lower crust. on the basis of an analysis of detrital chrome spinel grains found southwest of salzburg ( in the hallstatt melange area of the saalach zone, western central northern calcareous alps ), gawlick et al. ( 2015 ) propose that the eo - alpine orogeny stated earlier than the usually indicated timeframe ( early cretaceous ). these authors argue that their study indicates that in the southern northern calcareous alps ophiolite obduction occurred earlier, in the middle to early late jurassic. this obducted ophiolite stack erosion started in the kimmeridgian ( late jurassic ) and lasted until the aptian ( late early cretaceous ). erosion was slowed down by a kimmeridgian to earliest cretaceous carbonate platform that evolved on top of the nappe stack with the obducted ophiolites. it protected the ophiolites against erosion. afterwards, the ophiolites were quickly eroded. = = lateral escape = = lateral escape or extrusion refers to the horizontal ( sideways ) movement of a landmass. it can be sinistral ( left - lateral ) or dextral ( right β lateral ). the sideways movement is caused by a thrust. in the case
this article discusses how rocks are formed. there are also articles on physical rock formations, rock layerings ( strata ), and the formal naming of geologic formations. terrestrial rocks are formed by three main mechanisms : sedimentary rocks are formed through the gradual accumulation of sediments : for example, sand on a beach or mud on a river bed. as the sediments are buried they get compacted as more and more material is deposited on top. eventually the sediments will become so dense that they would essentially form a rock. this process is known as lithification. igneous rocks have crystallised from a melt or magma. the melt is made up of various components of pre - existing rocks which have been subjected to melting either at subduction zones or within the earth's mantle. the melt is hot and so passes upward through cooler country rock. as it moves, it cools and various rock types will form through a process known as fractional crystallisation. igneous rocks can be seen at mid - ocean ridges, areas of island arc volcanism or in intra - plate hotspots. metamorphic rocks once existed as igneous or sedimentary rocks, but have been subjected to varying degrees of pressure and heat within the earth's crust. the processes involved will change the composition and fabric of the rock and their original nature is often hard to distinguish. metamorphic rocks are typically found in areas of mountain building. rock can also form in the absence of a substantial pressure gradient as material that condensed from a protoplanetary disk, without ever undergoing any transformations in the interior of a large object such as a planet or moon. astrophysicists classify this as a fourth type of rock : primitive rock. this type is common in asteroids and meteorites. : 145 = = rock formation = = = = = 19th - century efforts to synthesize rocks = = = the synthetic investigation of rocks proceeds by experimental work that attempts to reproduce different rock types and to elucidate their origins and structures. in many cases no experiment is necessary. every stage in the origin of clays, sands and gravels can be seen in process around us, but where these have been converted into coherent shales, sandstone and conglomerates, and still more where they have experienced some degree of metamorphism, there are many obscure points about their history upon which experiment may yet throw light. attempts have been made to reproduce igneous rocks, by fusion of mixtures of crushed minerals or of chemicals in specially contrived furnaces. the earliest researches of this sort are
glaciovolcanism is volcanism and related phenomena associated with glacial ice. the ice commonly constrains the erupted material and melts to create meltwater. considerable melting of glacial ice can create massive lahars and glacial outburst floods known as jokulhlaups. = = general = = three forms of glaciovolcanism are known. subglacial eruptions occur when a volcano erupts under ice. such activity can produce landforms such as tuyas and subglacial mounds. ice - marginal volcanism takes place when material from a subaerial eruption makes lateral contact with ice ; ice - marginal lava flows are a product of this phenomenon. supraglacial eruptions deposit ejecta onto the surface of an ice sheet. world regions identified for possible glaciovolcanic activity include alaska, and western parts of canada, southern chile, argentina, iceland, and a couple of regions along antarctica's coast, such as the antarctic peninsula and the ross ice shelf. volcanologist bill mcguire noted in 2014, we see evidence of the earth β waking up β specifically in relation to seismic activity in areas of alaska where dramatic ice loss ( up to 1km vertical thickness ) has occurred over the last 100 years, and also in relation to the correlation in many high mountains terrains of increased landslide occurrence and heatwaves. there is no unequivocal evidence for a specific volcanic response, unless the high level of recent activity at the icelandic volcanoes is a reflection of unloading due to melting of the vatnajokull ice cap. certainly this whole region is uplifting by a few centimetres a year, so such a suggestion would not be completely unreasonable, even if we don β t ( yet? ) have any hard evidence. = = examples = = isostatic rebound in response to glacier retreat ( unloading ), increase in local salinity ( i. e., Ξ΄18osw ), have been attributed to increased volcanic activity at the onset of bΓΈlling β allerΓΈd, are associated with the interval of intense volcanic activity, hinting at an interaction between climate and volcanism - enhanced short - term melting of glaciers, possibly via albedo changes from particle fallout on glacier surfaces. = = see also = = pine island glacier = = references = =
study of the composition, structure, physical properties, dynamics, and history of earth materials, and the processes by which they are formed, moved, and changed. the field is a major academic discipline, and is also important for mineral and hydrocarbon extraction, knowledge about and mitigation of natural hazards, some geotechnical engineering fields, and understanding past climates and environments. = = = = geological evolution = = = = the geology of an area evolves through time as rock units are deposited and inserted and deformational processes change their shapes and locations. rock units are first emplaced either by deposition onto the surface or intrude into the overlying rock. deposition can occur when sediments settle onto the surface of the earth and later lithify into sedimentary rock, or when as volcanic material such as volcanic ash or lava flows, blanket the surface. igneous intrusions such as batholiths, laccoliths, dikes, and sills, push upwards into the overlying rock, and crystallize as they intrude. after the initial sequence of rocks has been deposited, the rock units can be deformed and / or metamorphosed. deformation typically occurs as a result of horizontal shortening, horizontal extension, or side - to - side ( strike - slip ) motion. these structural regimes broadly relate to convergent boundaries, divergent boundaries, and transform boundaries, respectively, between tectonic plates. = = = historical perspective = = = earth is estimated to have formed 4. 54 billion years ago from the solar nebula, along with the sun and other planets. the moon formed roughly 20 million years later. initially molten, the outer layer of the earth cooled, resulting in the solid crust. outgassing and volcanic activity produced the primordial atmosphere. condensing water vapor, most or all of which came from ice delivered by comets, produced the oceans and other water sources. the highly energetic chemistry is believed to have produced a self - replicating molecule around 4 billion years ago. continents formed, then broke up and reformed as the surface of earth reshaped over hundreds of millions of years, occasionally combining to make a supercontinent. roughly 750 million years ago, the earliest known supercontinent rodinia, began to break apart. the continents later recombined to form pannotia which broke apart about 540 million years ago, then finally pangaea, which broke apart about 180 million years ago. during the neoproterozoic era, freezing temperatures covered much
Answer:
|
erupting
| 0.3 |
An arid sandy place has very little
0. sustenance
1. sand
2. sun
3. heat
tropical deserts are located in regions between 15 and 30 degrees latitude. the environment is very extreme, and they have the highest average monthly temperature on earth. rainfall is sporadic ; precipitation may not be observed at all in a few years. in addition to these extreme environmental and climate conditions, most tropical deserts are covered with sand and rocks, and thus too flat and lacking in vegetation to block out the wind. wind may erode and transport sand, rocks and other materials ; these are known as eolian processes. landforms caused by wind erosion vary greatly in characteristics and size. representative landforms include depressions and pans, yardangs, inverted topography and ventifacts. no significant populations can survive in tropical deserts due to extreme aridity, heat and the paucity of vegetation ; only specific flora and fauna with special behavioral and physical mechanisms are supported. although tropical deserts are considered to be harsh and barren, they are in fact important sources of natural resources and play a significant role in economic development. besides the equatorial deserts, there are many hot deserts situated in the tropical zone. = = distribution = = = = = geographical distribution = = = tropical deserts are located in both continental interiors and coastal areas between the tropic of cancer and tropic of capricorn. representative deserts include the sahara desert in north africa, the australian desert in western and southern australia, arabian desert and syrian desert in western asia, the kalahari desert in southern africa, sonoran desert in the united states and mexico, mojave desert in the united states, thar desert in india and pakistan, dasht - e margo and registan desert in afghanistan and dasht - e kavir and dasht - e loot in iran. = = = controlling factor = = = tropics form a belt around the equator from latitude 3 degrees north to latitude 3 degrees south, which is called the intertropical convergence zone. tropical heat generates unstable air in this area, and air masses become extremely dry due to the loss of moisture during the process of tropical ascent. another significant determinant of tropical desert climate are hadley cells. hadley cells concentrate all precipitations in the hotter humid lower pressure equator, leaving colder higher pressure deserts with no precipitation. = = characteristics = = = = = temperature = = = tropical deserts have the highest average daily temperature on the planet, as both the energy input during the day and the loss of heat at night are large. this phenomenon causes an extremely large daily temperature range. specifically, temperatures in a low elevation inland
= = tropical deserts have the highest average daily temperature on the planet, as both the energy input during the day and the loss of heat at night are large. this phenomenon causes an extremely large daily temperature range. specifically, temperatures in a low elevation inland desert can reach 40Β°c to 50Β°c during the day, and drop to approximately 5Β°c at night ; the daily range is around 30 to 40Β°c. there are some other reasons for significant changes in temperature in tropical deserts. for instance, a lack of water and vegetation on the ground can enhance the absorption of the heat due to insolation. subsiding air from dominant high pressure areas in a cloud - free sky can also lead to large amounts of insolation ; a cloudless sky enables day temperature to escape rapidly at night. precipitation is very irregular in tropical deserts. the average annual precipitation in low latitude deserts is less than 250 mm. relative humidity is very low β only 10 % to 30 % in interior locations, and even the dewpoints are typically very low, often being well below the freezing mark. some deserts do not have rainfall all year round, they are located far from the ocean. high - pressure cells and high temperatures can also increase the level of aridity. = = = wind = = = wind greatly contributes to aridity in tropical deserts. if wind speed exceeds 80 km / h, it can generate dust storms and sandstorms and erode the rocky surface. therefore, wind plays an important role in shaping various landforms. this phenomenon is known as the eolian process. there are two types of eolian process : deflation and abrasion. first, deflation may cause the light lowering of ground surface, leading to deflation hollows, plains, basins, blowouts, wind - eroded plains and parabolic dunes. second, the eolian process leads to abrasion, which forms special landforms with a significant undercut. = = = landforms = = = various landforms are found in tropical deserts due to different kinds of eolian process. the major landforms are dunes, depressions and pans, yardangs, and inverted topography. = = = = dunes = = = = there are various kinds of dune in tropical deserts. representative dunes include dome dunes, transverse dunes, barchans, star dunes, shadow dunes, linear dunes and longitudinal dunes. = = = = depression = = = = a desert depression is caused by polygenetic factors such as wind erosion, broad
sand dune ecology describes the biological and physico - chemical interactions that are a characteristic of sand dunes. sand dune systems are excellent places for biodiversity, partly because they are not very productive for agriculture, and partly because disturbed, stressful, and stable habitats are present in proximity to each other. many of them are protected as nature reserves, and some are parts of larger conservation areas, incorporating other coastal habitats like salt marshes, mud flats, grasslands, scrub, and woodland. = = plant habitat = = sand dunes provide a range of habitats for a range of unusual, interesting and characteristic plants that can cope with disturbed habitats. in the uk these may include restharrow ononis repens, sand spurge euphorbia arenaria and ragwort senecio vulgaris - such plants are termed ruderals. other very specialised plants are adapted to the accretion of sand, surviving the continual burial of their shoots by sending up very rapid vertical growth. marram grass, ammophila arenaria specialises in this, and is largely responsible for the formation and stabilisation of many dunes by binding sand grains together. the sand couch - grass elytrigia juncea also performs this function on the seaward edge of the dunes, and is responsible, with some other pioneers like the sea rocket cakile maritima, for initiating the process of dune building by trapping wind blown sand. in accreting situations small mounds of vegetation or tide - washed debris form and tend to enlarge as the wind - speed drops in the lee of the mound, allowing blowing sand ( picked up from the off - shore banks ) to fall out of the air stream. the pioneering plants are physiologically adapted to withstand the problems of high salt contents in the air and soil, and are good examples of stress tolerators, as well as having some ruderal characteristics. = = inland side = = on the inland side of dunes conditions are less severe, and links type grasslands develop with a range of grassland herbs which benefit from the reasonable nutrient status and moderately high ph of the more stable soils, especially when enough humus has accumulated in stabilised soils for water retention to be improved. species like red fescue and lady's bedstraw are adapted to compete with each other - for nutrients, growing space and light, and are known as csr plants - i. e. having features of competitors, stress tolerators and ruderals in more or less equal proportions. there may also be areas in old blow
kilometers ( 23, 000 sq mi ) in southern egypt and northern sudan. this consists of a few feet of sand resting on bedrock. sand sheets are often remarkably flat and are sometimes described as desert peneplains. sand sheets are common in desert environments, particularly on the margins of dune fields, although they also occur within ergs. conditions that favor the formation of sand sheets, instead of dunes, may include surface cementation, a high water table, the effects of vegetation, periodic flooding, or sediments rich in grains too coarse for effective saltation. = = = dunes = = = a dune is an accumulations of sediment blown by the wind into a mound or ridge. they differ from sand shadows or sand drifts in that they are independent of any topographic obstacle. dunes have gentle upwind slopes on the windward side. the downwind portion of the dune, the lee slope, is commonly a steep avalanche slope referred to as a slipface. dunes may have more than one slipface. the minimum height of a slipface is about 30 centimeters. wind - blown sand moves up the gentle upwind side of the dune by saltation or creep. sand accumulates at the brink, the top of the slipface. when the buildup of sand at the brink exceeds the angle of repose, a small avalanche of grains slides down the slipface. grain by grain, the dune moves downwind. dunes take three general forms. linear dunes, also called longitudinal dunes or seifs, are aligned in the direction of the prevailing winds. transverse dunes, which include crescent dunes ( barchans ), are aligned perpendicular to the prevailing winds. more complex dunes, such as star dunes, form where the directions of the winds are highly variable. additional dune types arise from various kinds of topographic forcing, such as from isolated hills or escarpments. = = = = transverse dunes = = = = transverse dunes occur in areas dominated by a single direction of the prevailing wind. in areas where sand is not abundant, transverse dunes take the form of barchans or crescent dunes. these are not common, but they are highly recognizable, with a distinctive crescent shape with the tips of the crescent directed downwind. the dunes are widely separated by areas of bedrock or reg. barchans migrate up to 30 meters ( 98 ft ) per year, with the taller dunes migrating faster. barchans first form when some minor topographic feature creates a sand patch. this grows into a sand mound, and the converging streamlines of
sand sheets are flat, gently undulating plots of sand surfaced by grains that may be too large for saltation. they form approximately 40 percent of aeolian depositional surfaces. sand sheets exist where grain size is too large, or wind velocities too low, for dunes to form. = = references = =
Answer:
|
sustenance
| null |
An arid sandy place has very little
0. sustenance
1. sand
2. sun
3. heat
tropical deserts are located in regions between 15 and 30 degrees latitude. the environment is very extreme, and they have the highest average monthly temperature on earth. rainfall is sporadic ; precipitation may not be observed at all in a few years. in addition to these extreme environmental and climate conditions, most tropical deserts are covered with sand and rocks, and thus too flat and lacking in vegetation to block out the wind. wind may erode and transport sand, rocks and other materials ; these are known as eolian processes. landforms caused by wind erosion vary greatly in characteristics and size. representative landforms include depressions and pans, yardangs, inverted topography and ventifacts. no significant populations can survive in tropical deserts due to extreme aridity, heat and the paucity of vegetation ; only specific flora and fauna with special behavioral and physical mechanisms are supported. although tropical deserts are considered to be harsh and barren, they are in fact important sources of natural resources and play a significant role in economic development. besides the equatorial deserts, there are many hot deserts situated in the tropical zone. = = distribution = = = = = geographical distribution = = = tropical deserts are located in both continental interiors and coastal areas between the tropic of cancer and tropic of capricorn. representative deserts include the sahara desert in north africa, the australian desert in western and southern australia, arabian desert and syrian desert in western asia, the kalahari desert in southern africa, sonoran desert in the united states and mexico, mojave desert in the united states, thar desert in india and pakistan, dasht - e margo and registan desert in afghanistan and dasht - e kavir and dasht - e loot in iran. = = = controlling factor = = = tropics form a belt around the equator from latitude 3 degrees north to latitude 3 degrees south, which is called the intertropical convergence zone. tropical heat generates unstable air in this area, and air masses become extremely dry due to the loss of moisture during the process of tropical ascent. another significant determinant of tropical desert climate are hadley cells. hadley cells concentrate all precipitations in the hotter humid lower pressure equator, leaving colder higher pressure deserts with no precipitation. = = characteristics = = = = = temperature = = = tropical deserts have the highest average daily temperature on the planet, as both the energy input during the day and the loss of heat at night are large. this phenomenon causes an extremely large daily temperature range. specifically, temperatures in a low elevation inland
= = tropical deserts have the highest average daily temperature on the planet, as both the energy input during the day and the loss of heat at night are large. this phenomenon causes an extremely large daily temperature range. specifically, temperatures in a low elevation inland desert can reach 40Β°c to 50Β°c during the day, and drop to approximately 5Β°c at night ; the daily range is around 30 to 40Β°c. there are some other reasons for significant changes in temperature in tropical deserts. for instance, a lack of water and vegetation on the ground can enhance the absorption of the heat due to insolation. subsiding air from dominant high pressure areas in a cloud - free sky can also lead to large amounts of insolation ; a cloudless sky enables day temperature to escape rapidly at night. precipitation is very irregular in tropical deserts. the average annual precipitation in low latitude deserts is less than 250 mm. relative humidity is very low β only 10 % to 30 % in interior locations, and even the dewpoints are typically very low, often being well below the freezing mark. some deserts do not have rainfall all year round, they are located far from the ocean. high - pressure cells and high temperatures can also increase the level of aridity. = = = wind = = = wind greatly contributes to aridity in tropical deserts. if wind speed exceeds 80 km / h, it can generate dust storms and sandstorms and erode the rocky surface. therefore, wind plays an important role in shaping various landforms. this phenomenon is known as the eolian process. there are two types of eolian process : deflation and abrasion. first, deflation may cause the light lowering of ground surface, leading to deflation hollows, plains, basins, blowouts, wind - eroded plains and parabolic dunes. second, the eolian process leads to abrasion, which forms special landforms with a significant undercut. = = = landforms = = = various landforms are found in tropical deserts due to different kinds of eolian process. the major landforms are dunes, depressions and pans, yardangs, and inverted topography. = = = = dunes = = = = there are various kinds of dune in tropical deserts. representative dunes include dome dunes, transverse dunes, barchans, star dunes, shadow dunes, linear dunes and longitudinal dunes. = = = = depression = = = = a desert depression is caused by polygenetic factors such as wind erosion, broad
sand dune ecology describes the biological and physico - chemical interactions that are a characteristic of sand dunes. sand dune systems are excellent places for biodiversity, partly because they are not very productive for agriculture, and partly because disturbed, stressful, and stable habitats are present in proximity to each other. many of them are protected as nature reserves, and some are parts of larger conservation areas, incorporating other coastal habitats like salt marshes, mud flats, grasslands, scrub, and woodland. = = plant habitat = = sand dunes provide a range of habitats for a range of unusual, interesting and characteristic plants that can cope with disturbed habitats. in the uk these may include restharrow ononis repens, sand spurge euphorbia arenaria and ragwort senecio vulgaris - such plants are termed ruderals. other very specialised plants are adapted to the accretion of sand, surviving the continual burial of their shoots by sending up very rapid vertical growth. marram grass, ammophila arenaria specialises in this, and is largely responsible for the formation and stabilisation of many dunes by binding sand grains together. the sand couch - grass elytrigia juncea also performs this function on the seaward edge of the dunes, and is responsible, with some other pioneers like the sea rocket cakile maritima, for initiating the process of dune building by trapping wind blown sand. in accreting situations small mounds of vegetation or tide - washed debris form and tend to enlarge as the wind - speed drops in the lee of the mound, allowing blowing sand ( picked up from the off - shore banks ) to fall out of the air stream. the pioneering plants are physiologically adapted to withstand the problems of high salt contents in the air and soil, and are good examples of stress tolerators, as well as having some ruderal characteristics. = = inland side = = on the inland side of dunes conditions are less severe, and links type grasslands develop with a range of grassland herbs which benefit from the reasonable nutrient status and moderately high ph of the more stable soils, especially when enough humus has accumulated in stabilised soils for water retention to be improved. species like red fescue and lady's bedstraw are adapted to compete with each other - for nutrients, growing space and light, and are known as csr plants - i. e. having features of competitors, stress tolerators and ruderals in more or less equal proportions. there may also be areas in old blow
kilometers ( 23, 000 sq mi ) in southern egypt and northern sudan. this consists of a few feet of sand resting on bedrock. sand sheets are often remarkably flat and are sometimes described as desert peneplains. sand sheets are common in desert environments, particularly on the margins of dune fields, although they also occur within ergs. conditions that favor the formation of sand sheets, instead of dunes, may include surface cementation, a high water table, the effects of vegetation, periodic flooding, or sediments rich in grains too coarse for effective saltation. = = = dunes = = = a dune is an accumulations of sediment blown by the wind into a mound or ridge. they differ from sand shadows or sand drifts in that they are independent of any topographic obstacle. dunes have gentle upwind slopes on the windward side. the downwind portion of the dune, the lee slope, is commonly a steep avalanche slope referred to as a slipface. dunes may have more than one slipface. the minimum height of a slipface is about 30 centimeters. wind - blown sand moves up the gentle upwind side of the dune by saltation or creep. sand accumulates at the brink, the top of the slipface. when the buildup of sand at the brink exceeds the angle of repose, a small avalanche of grains slides down the slipface. grain by grain, the dune moves downwind. dunes take three general forms. linear dunes, also called longitudinal dunes or seifs, are aligned in the direction of the prevailing winds. transverse dunes, which include crescent dunes ( barchans ), are aligned perpendicular to the prevailing winds. more complex dunes, such as star dunes, form where the directions of the winds are highly variable. additional dune types arise from various kinds of topographic forcing, such as from isolated hills or escarpments. = = = = transverse dunes = = = = transverse dunes occur in areas dominated by a single direction of the prevailing wind. in areas where sand is not abundant, transverse dunes take the form of barchans or crescent dunes. these are not common, but they are highly recognizable, with a distinctive crescent shape with the tips of the crescent directed downwind. the dunes are widely separated by areas of bedrock or reg. barchans migrate up to 30 meters ( 98 ft ) per year, with the taller dunes migrating faster. barchans first form when some minor topographic feature creates a sand patch. this grows into a sand mound, and the converging streamlines of
sand sheets are flat, gently undulating plots of sand surfaced by grains that may be too large for saltation. they form approximately 40 percent of aeolian depositional surfaces. sand sheets exist where grain size is too large, or wind velocities too low, for dunes to form. = = references = =
Answer:
|
heat
| 0.3 |
Which likely needs the least food?
0. a cat
1. a snake
2. a shark
3. a dog
situation could be defined as net energy gain per unit time. however, for a different forager, the time it takes to digest the food after eating could be a more significant cost than the time and energy spent looking for food. in this case, the currency could be defined as net energy gain per digestive turnover time instead of net energy gain per unit time. furthermore, benefits and costs can depend on a forager's community. for example, a forager living in a hive would most likely forage in a manner that would maximize efficiency for its colony rather than itself. by identifying the currency, one can construct a hypothesis about which benefits and costs are important to the forager in question. constraints are hypotheses about the limitations that are placed on an animal. these limitations can be due to features of the environment or the physiology of the animal and could limit their foraging efficiency. the time that it takes for the forager to travel from the nesting site to the foraging site is an example of a constraint. the maximum number of food items a forager is able to carry back to its nesting site is another example of a constraint. there could also be cognitive constraints on animals, such as limits to learning and memory. the more constraints that one is able to identify in a given system, the more predictive power the model will have. given the hypotheses about the currency and the constraints, the optimal decision rule is the model's prediction of what the animal's best foraging strategy should be. possible examples of optimal decision rules could be the optimal number of food items that an animal should carry back to its nesting site or the optimal size of a food item that an animal should feed on. figure 1, shows an example of how an optimal decision rule could be determined from a graphical model. the curve represents the energy gain per cost ( e ) for adopting foraging strategy x. energy gain per cost is the currency being optimized. the constraints of the system determine the shape of this curve. the optimal decision rule ( x * ) is the strategy for which the currency, energy gain per costs, is the greatest. optimal foraging models can look very different and become very complex, depending on the nature of the currency and the number of constraints considered. however, the general principles of currency, constraints, and optimal decision rule remain the same for all models. to test a model, one can compare the predicted strategy to the animal's actual foraging behavior. if the model fits the observed data well, then the hyp
ocean currents. the most abundant zooplankton species are copepods and krill : tiny crustaceans that are the most numerous animals on earth. other types of zooplankton include jelly fish and the larvae of fish, marine worms, starfish, and other marine organisms ". in turn, the zooplankton are eaten by filter - feeding animals, including some seabirds, small forage fish like herrings and sardines, whale sharks, manta rays, and the largest animal in the world, the blue whale. yet again, moving up the foodchain, the small forage fish are in turn eaten by larger predators, such as tuna, marlin, sharks, large squid, seabirds, dolphins, and toothed whales. = = open ocean = = the open ocean is relatively unproductive because of a lack of nutrients, yet because it is so vast, it has more overall primary production than any other marine habitat. only about 10 percent of marine species live in the open ocean. but among them are the largest and fastest of all marine animals, as well as the animals that dive the deepest and migrate the longest. in the depths lurk animal that, to our eyes, appear hugely alien. = = = deep sea = = = the deep sea starts at the aphotic zone, the point where sunlight loses most of its energy in the water. many life forms that live at these depths have the ability to create their own light a unique evolution known as bio - luminescence. in the deep ocean, the waters extend far below the epipelagic zone, and support very different types of pelagic life forms adapted to living in these deeper zones. much of the aphotic zone's energy is supplied by the open ocean in the form of detritus. in deep water, marine snow is a continuous shower of mostly organic detritus falling from the upper layers of the water column. its origin lies in activities within the productive photic zone. marine snow includes dead or dying plankton, protists ( diatoms ), fecal matter, sand, soot and other inorganic dust. the " snowflakes " grow over time and may reach several centimetres in diameter, travelling for weeks before reaching the ocean floor. however, most organic components of marine snow are consumed by microbes, zooplankton and other filter - feeding animals within the first 1, 000 metres of their journey, that is, within the ep
includes the cats, dogs, and bears ), 177 are solitary ; and 35 of the 37 wild cats are solitary, including the cougar and cheetah. however, the solitary cougar does allow other cougars to share in a kill, and the coyote can be either solitary or social. other solitary predators include the northern pike, wolf spiders and all the thousands of species of solitary wasps among arthropods, and many microorganisms and zooplankton. = = specialization = = = = = physical adaptations = = = under the pressure of natural selection, predators have evolved a variety of physical adaptations for detecting, catching, killing, and digesting prey. these include speed, agility, stealth, sharp senses, claws, teeth, filters, and suitable digestive systems. for detecting prey, predators have well - developed vision, smell, or hearing. predators as diverse as owls and jumping spiders have forward - facing eyes, providing accurate binocular vision over a relatively narrow field of view, whereas prey animals often have less acute all - round vision. animals such as foxes can smell their prey even when it is concealed under 2 feet ( 60 cm ) of snow or earth. many predators have acute hearing, and some such as echolocating bats hunt exclusively by active or passive use of sound. predators including big cats, birds of prey, and ants share powerful jaws, sharp teeth, or claws which they use to seize and kill their prey. some predators such as snakes and fish - eating birds like herons and cormorants swallow their prey whole ; some snakes can unhinge their jaws to allow them to swallow large prey, while fish - eating birds have long spear - like beaks that they use to stab and grip fast - moving and slippery prey. fish and other predators have developed the ability to crush or open the armoured shells of molluscs. many predators are powerfully built and can catch and kill animals larger than themselves ; this applies as much to small predators such as ants and shrews as to big and visibly muscular carnivores like the cougar and lion. = = = diet and behaviour = = = predators are often highly specialized in their diet and hunting behaviour ; for example, the eurasian lynx only hunts small ungulates. others such as leopards are more opportunistic generalists, preying on at least 100 species. the specialists may be highly adapted to capturing their preferred prey, whereas generalists may be better able to switch to other prey when
time for prey1. since it is always favorable to choose to eat prey1, the choice to eat prey1 is not dependent on the abundance of prey2. but since the length of s1 ( i. e. how difficult it is to find prey1 ) is logically dependent on the density of prey1, the choice to eat prey2 is dependent on the abundance of prey1. = = = generalist and specialist diets = = = the optimal diet model also predicts that different types of animals should adopt different diets based on variations in search time. this idea is an extension of the model of prey choice that was discussed above. the equation, e2 / h2 > e1 / ( h1 + s1 ), can be rearranged to give : s1 > [ ( e1h2 ) / e2 ] β h1. this rearranged form gives the threshold for how long s1 must be for an animal to choose to eat both prey1 and prey2. animals that have s1s that reach the threshold are defined as generalists. in nature, generalists include a wide range of prey items in their diet. an example of a generalist is a mouse, which consumes a large variety of seeds, grains, and nuts. in contrast, predators with relatively short s1s are still better off choosing to eat only prey1. these types of animals are defined as specialists and have very exclusive diets in nature. an example of a specialist is the koala, which solely consumes eucalyptus leaves. in general, different animals across the four functional classes of predators exhibit strategies ranging across a continuum between being a generalist and a specialist. additionally, since the choice to eat prey2 is dependent on the abundance of prey1 ( as discussed earlier ), if prey1 becomes so scarce that s1 reaches the threshold, then the animal should switch from exclusively eating prey1 to eating both prey1 and prey2. in other words, if the food within a specialist's diet becomes very scarce, a specialist can sometimes switch to being a generalist. = = = functional response curves = = = as previously mentioned, the amount of time it takes to search for a prey item depends on the density of the prey. functional response curves show the rate of prey capture as a function of food density and can be used in conjunction with the optimal diet theory to predict foraging behavior of predators. there are three different types of functional response curves. for a type i functional response curve,
again as energy and nutrients into the ecosystem for recycling. decomposers, such as bacteria and fungi ( mushrooms ), feed on waste and dead matter, converting it into inorganic chemicals that can be recycled as mineral nutrients for plants to use again. trophic levels can be represented by numbers, starting at level 1 with plants. further trophic levels are numbered subsequently according to how far the organism is along the food chain. level 1 plants and algae make their own food and are called producers. level 2 herbivores eat plants and are called primary consumers. level 3 carnivores that eat herbivores are called secondary consumers. level 4 carnivores that eat other carnivores are called tertiary consumers. apex predator by definition, healthy adult apex predators have no predators ( with members of their own species a possible exception ) and are at the highest numbered level of their food web. in real - world ecosystems, there is more than one food chain for most organisms, since most organisms eat more than one kind of food or are eaten by more than one type of predator. a diagram that sets out the intricate network of intersecting and overlapping food chains for an ecosystem is called its food web. decomposers are often left off food webs, but if included, they mark the end of a food chain. thus food chains start with primary producers and end with decay and decomposers. since decomposers recycle nutrients, leaving them so they can be reused by primary producers, they are sometimes regarded as occupying their own trophic level. the trophic level of a species may vary if it has a choice of diet. virtually all plants and phytoplankton are purely phototrophic and are at exactly level 1. 0. many worms are at around 2. 1 ; insects 2. 2 ; jellyfish 3. 0 ; birds 3. 6. a 2013 study estimates the average trophic level of human beings at 2. 21, similar to pigs or anchovies. this is only an average, and plainly both modern and ancient human eating habits are complex and vary greatly. for example, a traditional inuit living on a diet consisting primarily of seals would have a trophic level of nearly 5. = = biomass transfer efficiency = = in general, each trophic level relates to the one below it by absorbing some of the energy it consumes, and in this way can be regarded as resting on, or supported by, the next lower trophic level
Answer:
|
a snake
| null |
Which likely needs the least food?
0. a cat
1. a snake
2. a shark
3. a dog
situation could be defined as net energy gain per unit time. however, for a different forager, the time it takes to digest the food after eating could be a more significant cost than the time and energy spent looking for food. in this case, the currency could be defined as net energy gain per digestive turnover time instead of net energy gain per unit time. furthermore, benefits and costs can depend on a forager's community. for example, a forager living in a hive would most likely forage in a manner that would maximize efficiency for its colony rather than itself. by identifying the currency, one can construct a hypothesis about which benefits and costs are important to the forager in question. constraints are hypotheses about the limitations that are placed on an animal. these limitations can be due to features of the environment or the physiology of the animal and could limit their foraging efficiency. the time that it takes for the forager to travel from the nesting site to the foraging site is an example of a constraint. the maximum number of food items a forager is able to carry back to its nesting site is another example of a constraint. there could also be cognitive constraints on animals, such as limits to learning and memory. the more constraints that one is able to identify in a given system, the more predictive power the model will have. given the hypotheses about the currency and the constraints, the optimal decision rule is the model's prediction of what the animal's best foraging strategy should be. possible examples of optimal decision rules could be the optimal number of food items that an animal should carry back to its nesting site or the optimal size of a food item that an animal should feed on. figure 1, shows an example of how an optimal decision rule could be determined from a graphical model. the curve represents the energy gain per cost ( e ) for adopting foraging strategy x. energy gain per cost is the currency being optimized. the constraints of the system determine the shape of this curve. the optimal decision rule ( x * ) is the strategy for which the currency, energy gain per costs, is the greatest. optimal foraging models can look very different and become very complex, depending on the nature of the currency and the number of constraints considered. however, the general principles of currency, constraints, and optimal decision rule remain the same for all models. to test a model, one can compare the predicted strategy to the animal's actual foraging behavior. if the model fits the observed data well, then the hyp
ocean currents. the most abundant zooplankton species are copepods and krill : tiny crustaceans that are the most numerous animals on earth. other types of zooplankton include jelly fish and the larvae of fish, marine worms, starfish, and other marine organisms ". in turn, the zooplankton are eaten by filter - feeding animals, including some seabirds, small forage fish like herrings and sardines, whale sharks, manta rays, and the largest animal in the world, the blue whale. yet again, moving up the foodchain, the small forage fish are in turn eaten by larger predators, such as tuna, marlin, sharks, large squid, seabirds, dolphins, and toothed whales. = = open ocean = = the open ocean is relatively unproductive because of a lack of nutrients, yet because it is so vast, it has more overall primary production than any other marine habitat. only about 10 percent of marine species live in the open ocean. but among them are the largest and fastest of all marine animals, as well as the animals that dive the deepest and migrate the longest. in the depths lurk animal that, to our eyes, appear hugely alien. = = = deep sea = = = the deep sea starts at the aphotic zone, the point where sunlight loses most of its energy in the water. many life forms that live at these depths have the ability to create their own light a unique evolution known as bio - luminescence. in the deep ocean, the waters extend far below the epipelagic zone, and support very different types of pelagic life forms adapted to living in these deeper zones. much of the aphotic zone's energy is supplied by the open ocean in the form of detritus. in deep water, marine snow is a continuous shower of mostly organic detritus falling from the upper layers of the water column. its origin lies in activities within the productive photic zone. marine snow includes dead or dying plankton, protists ( diatoms ), fecal matter, sand, soot and other inorganic dust. the " snowflakes " grow over time and may reach several centimetres in diameter, travelling for weeks before reaching the ocean floor. however, most organic components of marine snow are consumed by microbes, zooplankton and other filter - feeding animals within the first 1, 000 metres of their journey, that is, within the ep
includes the cats, dogs, and bears ), 177 are solitary ; and 35 of the 37 wild cats are solitary, including the cougar and cheetah. however, the solitary cougar does allow other cougars to share in a kill, and the coyote can be either solitary or social. other solitary predators include the northern pike, wolf spiders and all the thousands of species of solitary wasps among arthropods, and many microorganisms and zooplankton. = = specialization = = = = = physical adaptations = = = under the pressure of natural selection, predators have evolved a variety of physical adaptations for detecting, catching, killing, and digesting prey. these include speed, agility, stealth, sharp senses, claws, teeth, filters, and suitable digestive systems. for detecting prey, predators have well - developed vision, smell, or hearing. predators as diverse as owls and jumping spiders have forward - facing eyes, providing accurate binocular vision over a relatively narrow field of view, whereas prey animals often have less acute all - round vision. animals such as foxes can smell their prey even when it is concealed under 2 feet ( 60 cm ) of snow or earth. many predators have acute hearing, and some such as echolocating bats hunt exclusively by active or passive use of sound. predators including big cats, birds of prey, and ants share powerful jaws, sharp teeth, or claws which they use to seize and kill their prey. some predators such as snakes and fish - eating birds like herons and cormorants swallow their prey whole ; some snakes can unhinge their jaws to allow them to swallow large prey, while fish - eating birds have long spear - like beaks that they use to stab and grip fast - moving and slippery prey. fish and other predators have developed the ability to crush or open the armoured shells of molluscs. many predators are powerfully built and can catch and kill animals larger than themselves ; this applies as much to small predators such as ants and shrews as to big and visibly muscular carnivores like the cougar and lion. = = = diet and behaviour = = = predators are often highly specialized in their diet and hunting behaviour ; for example, the eurasian lynx only hunts small ungulates. others such as leopards are more opportunistic generalists, preying on at least 100 species. the specialists may be highly adapted to capturing their preferred prey, whereas generalists may be better able to switch to other prey when
time for prey1. since it is always favorable to choose to eat prey1, the choice to eat prey1 is not dependent on the abundance of prey2. but since the length of s1 ( i. e. how difficult it is to find prey1 ) is logically dependent on the density of prey1, the choice to eat prey2 is dependent on the abundance of prey1. = = = generalist and specialist diets = = = the optimal diet model also predicts that different types of animals should adopt different diets based on variations in search time. this idea is an extension of the model of prey choice that was discussed above. the equation, e2 / h2 > e1 / ( h1 + s1 ), can be rearranged to give : s1 > [ ( e1h2 ) / e2 ] β h1. this rearranged form gives the threshold for how long s1 must be for an animal to choose to eat both prey1 and prey2. animals that have s1s that reach the threshold are defined as generalists. in nature, generalists include a wide range of prey items in their diet. an example of a generalist is a mouse, which consumes a large variety of seeds, grains, and nuts. in contrast, predators with relatively short s1s are still better off choosing to eat only prey1. these types of animals are defined as specialists and have very exclusive diets in nature. an example of a specialist is the koala, which solely consumes eucalyptus leaves. in general, different animals across the four functional classes of predators exhibit strategies ranging across a continuum between being a generalist and a specialist. additionally, since the choice to eat prey2 is dependent on the abundance of prey1 ( as discussed earlier ), if prey1 becomes so scarce that s1 reaches the threshold, then the animal should switch from exclusively eating prey1 to eating both prey1 and prey2. in other words, if the food within a specialist's diet becomes very scarce, a specialist can sometimes switch to being a generalist. = = = functional response curves = = = as previously mentioned, the amount of time it takes to search for a prey item depends on the density of the prey. functional response curves show the rate of prey capture as a function of food density and can be used in conjunction with the optimal diet theory to predict foraging behavior of predators. there are three different types of functional response curves. for a type i functional response curve,
again as energy and nutrients into the ecosystem for recycling. decomposers, such as bacteria and fungi ( mushrooms ), feed on waste and dead matter, converting it into inorganic chemicals that can be recycled as mineral nutrients for plants to use again. trophic levels can be represented by numbers, starting at level 1 with plants. further trophic levels are numbered subsequently according to how far the organism is along the food chain. level 1 plants and algae make their own food and are called producers. level 2 herbivores eat plants and are called primary consumers. level 3 carnivores that eat herbivores are called secondary consumers. level 4 carnivores that eat other carnivores are called tertiary consumers. apex predator by definition, healthy adult apex predators have no predators ( with members of their own species a possible exception ) and are at the highest numbered level of their food web. in real - world ecosystems, there is more than one food chain for most organisms, since most organisms eat more than one kind of food or are eaten by more than one type of predator. a diagram that sets out the intricate network of intersecting and overlapping food chains for an ecosystem is called its food web. decomposers are often left off food webs, but if included, they mark the end of a food chain. thus food chains start with primary producers and end with decay and decomposers. since decomposers recycle nutrients, leaving them so they can be reused by primary producers, they are sometimes regarded as occupying their own trophic level. the trophic level of a species may vary if it has a choice of diet. virtually all plants and phytoplankton are purely phototrophic and are at exactly level 1. 0. many worms are at around 2. 1 ; insects 2. 2 ; jellyfish 3. 0 ; birds 3. 6. a 2013 study estimates the average trophic level of human beings at 2. 21, similar to pigs or anchovies. this is only an average, and plainly both modern and ancient human eating habits are complex and vary greatly. for example, a traditional inuit living on a diet consisting primarily of seals would have a trophic level of nearly 5. = = biomass transfer efficiency = = in general, each trophic level relates to the one below it by absorbing some of the energy it consumes, and in this way can be regarded as resting on, or supported by, the next lower trophic level
Answer:
|
a dog
| 0.3 |
if a body of water loses all water then that body of water is what?
0. thriving
1. defunct
2. flowing
3. growing
not all runoff flows into rivers ; much of it soaks into the ground as infiltration. some water infiltrates deep into the ground and replenishes aquifers, which can store freshwater for long periods of time. some infiltration stays close to the land surface and can seep back into surface - water bodies ( and the ocean ) as groundwater discharge or be taken up by plants and transferred back to the atmosphere as water vapor by transpiration. some groundwater finds openings in the land surface and emerges as freshwater springs. in river valleys and floodplains, there is often continuous water exchange between surface water and ground water in the hyporheic zone. over time, the water returns to the ocean, to continue the water cycle. the ocean plays a key role in the water cycle. the ocean holds " 97 % of the total water on the planet ; 78 % of global precipitation occurs over the ocean, and it is the source of 86 % of global evaporation ". important physical processes within the water cycle include ( in alphabetical order ) : advection : the movement of water through the atmosphere. without advection, water that evaporated over the oceans could not precipitate over land. atmospheric rivers that move large volumes of water vapor over long distances are an example of advection. condensation : the transformation of water vapor to liquid water droplets in the air, creating clouds and fog. evaporation : the transformation of water from liquid to gas phases as it moves from the ground or bodies of water into the overlying atmosphere. the source of energy for evaporation is primarily solar radiation. evaporation often implicitly includes transpiration from plants, though together they are specifically referred to as evapotranspiration. total annual evapotranspiration amounts to approximately 505, 000 km3 ( 121, 000 cu mi ) of water, 434, 000 km3 ( 104, 000 cu mi ) of which evaporates from the oceans. 86 % of global evaporation occurs over the ocean. infiltration : the flow of water from the ground surface into the ground. once infiltrated, the water becomes soil moisture or groundwater. a recent global study using water stable isotopes, however, shows that not all soil moisture is equally available for groundwater recharge or for plant transpiration. percolation : water flows vertically through the soil and rocks under the influence of gravity. precipitation : condensed water vapor that falls to the earth's surface.
change has resulted in less water available for rivers during the summer. regulation of pollution, dam removal, and sewage treatment have helped to improve water quality and restore river habitats. certain organisms such as sponges and fungi are useful bioindicators for river health. = = topography = = = = = definition = = = a river is a natural flow of freshwater that flows on or through land towards another body of water downhill. this flow can be into a lake, an ocean, or another river. a stream refers to water that flows in a natural channel, a geographic feature that can contain flowing water. a stream may also be referred to as a watercourse. the study of the movement of water as it occurs on earth is called hydrology, and their effect on the landscape is covered by geomorphology. = = = source and drainage basin = = = rivers are part of the water cycle, the continuous processes by which water moves about earth. this means that all water that flows in rivers must ultimately come from precipitation. the sides of rivers have land that is at a higher elevation than the river itself, and in these areas, water flows downhill into the river. the headwaters of a river are the smaller streams that feed a river, and make up the river's source. these streams may be small and flow rapidly down the sides of mountains. all of the land uphill of a river that feeds it with water in this way is in that river's drainage basin or watershed. a ridge of higher elevation land is what typically separates drainage basins ; water on one side of a ridge will flow into one set of rivers, and water on the other side will flow into another. one example of this is the continental divide of the americas in the rocky mountains. water on the western side of the divide flows into the pacific ocean, whereas water on the other side flows into the atlantic ocean. not all precipitation flows directly into rivers ; some water seeps into underground aquifers. these, in turn, can still feed rivers via the water table, the groundwater beneath the surface of the land stored in the soil. water flows into rivers in places where the river's elevation is lower than that of the water table. this phenomenon is why rivers can still flow even during times of drought. rivers are also fed by the melting of snow glaciers present in higher elevation regions. in summer months, higher temperatures melt snow and ice, causing additional water to flow into rivers. glacier melt can supplement snow melt in times like the late summer,
vegetation found on free - draining acidic soils. heterotroph see consumer. homeostasis the property of a system by which it regulates its internal environment and maintains a constant and stable condition ; e. g. endothermic animals maintaining a constant body temperature. host an organism that harbors a parasitic, mutualistic, or commensal symbiont. human ecology a branch of ecology that studies the relationships between humans and their natural, social, and built environments. humus hydrologic cycle the cycle or process of evaporation and condensation of water and its distribution across the earth as driven by solar energy. also called the water cycle. hydrophyte see aquatic plant. hydrosphere the combined mass of water found on, under and above the surface of the earth. hydrothermal vent an underwater steaming fissure that has a unique ecosystem. hypoxia reduced oxygen content of air or a body of water, detrimental to aerobic organisms. = = i = = illegitimate receiver an organism that intercepts a signal intended for another organism, to the fitness detriment of either the signaler or the legitimate receiver of the signal. indicator species any living species that defines a trait or characteristic of its environment. the presence and / or abundance of organisms of these species can be used as an indication of the health of a given ecosystem. instinctive behavior the inherent inclination of an organism towards a particular complex behavior. insular biogeography the study of the distributions of biological communities on islands. intermediate disturbance hypothesis a theory that tries to predict how species diversity will change with varying levels of disturbance. interspecific competition a form of competition that occurs between individuals of different species, e. g. when different species try to use the same resources in an environment. contrast intraspecific competition. intertidal zone a coastal area periodically submerged underwater by the action of tides. intraspecific competition a form of competition that occurs between individuals of the same species, e. g. when members of the same species compete for territories or access to mates. compare interspecific competition. invasive species a non - native species whose introduction to an area causes economic or environmental harm or harm to human health. ion exchange a reversible chemical reaction where ions with the same charge are switched. this principle is used in the purification of waste water. = = j = = jungle a dense, wet, humid forest, often tropical, which supports a large variety of wild plant and animal species. = = k = = k - selected
a river is a natural stream of fresh water that flows on land or inside caves towards another body of water at a lower elevation, such as an ocean, lake, or another river. a river may run dry before reaching the end of its course if it runs out of water, or only flow during certain seasons. rivers are regulated by the water cycle, the processes by which water moves around the earth. water first enters rivers through precipitation, whether from rainfall, the runoff of water down a slope, the melting of glaciers or snow, or seepage from aquifers beneath the surface of the earth. rivers flow in channeled watercourses and merge in confluences to form drainage basins, or catchments, areas where surface water eventually flows to a common outlet. rivers have a great effect on the landscape around them. they may regularly overflow their banks and flood the surrounding area, spreading nutrients to the surrounding area. sediment or alluvium carried by rivers shapes the landscape around it, forming deltas and islands where the flow slows down. rivers rarely run in a straight line, instead, they bend or meander ; the locations of a river's banks can change frequently. rivers get their alluvium from erosion, which carves rock into canyons and valleys. rivers have sustained human and animal life for millennia, including the first human civilizations. the organisms that live around or in a river such as fish, aquatic plants, fungi, molluscs, and insects have different roles, including primary production, processing organic matter, predation, parasitism, and decomposition. rivers have produced abundant resources for humans, including food, transportation, drinking water, and recreation. humans have throughout history engineered rivers to prevent flooding, irrigate crops, perform work with water wheels, and produce hydroelectricity from dams. people associate rivers with life and fertility and have strong religious, political, social, and mythological attachments to them. rivers and river ecosystems are threatened by water pollution, climate change, and human activity. the construction of dams, canals, levees, and other engineered structures has eliminated habitats, has caused the extinction of some species, increased nutrient avilability to toxic levels, and lowered the amount of alluvium flowing through rivers. decreased snowfall from climate change has resulted in less water available for rivers during the summer. regulation of pollution, dam removal, and sewage treatment have helped to improve water quality and restore river habitats. certain organisms such as sponges and fungi are useful bioindicators for river
a river is a natural stream of fresh water that flows on land or inside caves towards another body of water at a lower elevation, such as an ocean, lake, or another river. a river may run dry before reaching the end of its course if it runs out of water, or only flow during certain seasons. rivers are regulated by the water cycle, the processes by which water moves around the earth. water first enters rivers through precipitation, whether from rainfall, the runoff of water down a slope, the melting of glaciers or snow, or seepage from aquifers beneath the surface of the earth. rivers flow in channeled watercourses and merge in confluences to form drainage basins, or catchments, areas where surface water eventually flows to a common outlet. rivers have a great effect on the landscape around them. they may regularly overflow their banks and flood the surrounding area, spreading nutrients to the surrounding area. sediment or alluvium carried by rivers shapes the landscape around it, forming deltas and islands where the flow slows down. rivers rarely run in a straight line, instead, they bend or meander ; the locations of a river's banks can change frequently. rivers get their alluvium from erosion, which carves rock into canyons and valleys. rivers have sustained human and animal life for millennia, including the first human civilizations. the organisms that live around or in a river such as fish, aquatic plants, fungi, molluscs, and insects have different roles, including primary production, processing organic matter, predation, parasitism, and decomposition. rivers have produced abundant resources for humans, including food, transportation, drinking water, and recreation. humans have throughout history engineered rivers to prevent flooding, irrigate crops, perform work with water wheels, and produce hydroelectricity from dams. people associate rivers with life and fertility and have strong religious, political, social, and mythological attachments to them. rivers and river ecosystems are threatened by water pollution, climate change, and human activity. the construction of dams, canals, levees, and other engineered structures has eliminated habitats, has caused the extinction of some species, increased nutrient avilability to toxic levels, and lowered the amount of alluvium flowing through rivers. decreased snowfall from climate change has resulted in less water available for rivers during the summer. regulation of pollution, dam removal, and sewage treatment have helped to improve water quality and restore river habitats. certain organisms such as sponges and fungi are useful bioindicators for river
Answer:
|
defunct
| null |
if a body of water loses all water then that body of water is what?
0. thriving
1. defunct
2. flowing
3. growing
not all runoff flows into rivers ; much of it soaks into the ground as infiltration. some water infiltrates deep into the ground and replenishes aquifers, which can store freshwater for long periods of time. some infiltration stays close to the land surface and can seep back into surface - water bodies ( and the ocean ) as groundwater discharge or be taken up by plants and transferred back to the atmosphere as water vapor by transpiration. some groundwater finds openings in the land surface and emerges as freshwater springs. in river valleys and floodplains, there is often continuous water exchange between surface water and ground water in the hyporheic zone. over time, the water returns to the ocean, to continue the water cycle. the ocean plays a key role in the water cycle. the ocean holds " 97 % of the total water on the planet ; 78 % of global precipitation occurs over the ocean, and it is the source of 86 % of global evaporation ". important physical processes within the water cycle include ( in alphabetical order ) : advection : the movement of water through the atmosphere. without advection, water that evaporated over the oceans could not precipitate over land. atmospheric rivers that move large volumes of water vapor over long distances are an example of advection. condensation : the transformation of water vapor to liquid water droplets in the air, creating clouds and fog. evaporation : the transformation of water from liquid to gas phases as it moves from the ground or bodies of water into the overlying atmosphere. the source of energy for evaporation is primarily solar radiation. evaporation often implicitly includes transpiration from plants, though together they are specifically referred to as evapotranspiration. total annual evapotranspiration amounts to approximately 505, 000 km3 ( 121, 000 cu mi ) of water, 434, 000 km3 ( 104, 000 cu mi ) of which evaporates from the oceans. 86 % of global evaporation occurs over the ocean. infiltration : the flow of water from the ground surface into the ground. once infiltrated, the water becomes soil moisture or groundwater. a recent global study using water stable isotopes, however, shows that not all soil moisture is equally available for groundwater recharge or for plant transpiration. percolation : water flows vertically through the soil and rocks under the influence of gravity. precipitation : condensed water vapor that falls to the earth's surface.
change has resulted in less water available for rivers during the summer. regulation of pollution, dam removal, and sewage treatment have helped to improve water quality and restore river habitats. certain organisms such as sponges and fungi are useful bioindicators for river health. = = topography = = = = = definition = = = a river is a natural flow of freshwater that flows on or through land towards another body of water downhill. this flow can be into a lake, an ocean, or another river. a stream refers to water that flows in a natural channel, a geographic feature that can contain flowing water. a stream may also be referred to as a watercourse. the study of the movement of water as it occurs on earth is called hydrology, and their effect on the landscape is covered by geomorphology. = = = source and drainage basin = = = rivers are part of the water cycle, the continuous processes by which water moves about earth. this means that all water that flows in rivers must ultimately come from precipitation. the sides of rivers have land that is at a higher elevation than the river itself, and in these areas, water flows downhill into the river. the headwaters of a river are the smaller streams that feed a river, and make up the river's source. these streams may be small and flow rapidly down the sides of mountains. all of the land uphill of a river that feeds it with water in this way is in that river's drainage basin or watershed. a ridge of higher elevation land is what typically separates drainage basins ; water on one side of a ridge will flow into one set of rivers, and water on the other side will flow into another. one example of this is the continental divide of the americas in the rocky mountains. water on the western side of the divide flows into the pacific ocean, whereas water on the other side flows into the atlantic ocean. not all precipitation flows directly into rivers ; some water seeps into underground aquifers. these, in turn, can still feed rivers via the water table, the groundwater beneath the surface of the land stored in the soil. water flows into rivers in places where the river's elevation is lower than that of the water table. this phenomenon is why rivers can still flow even during times of drought. rivers are also fed by the melting of snow glaciers present in higher elevation regions. in summer months, higher temperatures melt snow and ice, causing additional water to flow into rivers. glacier melt can supplement snow melt in times like the late summer,
vegetation found on free - draining acidic soils. heterotroph see consumer. homeostasis the property of a system by which it regulates its internal environment and maintains a constant and stable condition ; e. g. endothermic animals maintaining a constant body temperature. host an organism that harbors a parasitic, mutualistic, or commensal symbiont. human ecology a branch of ecology that studies the relationships between humans and their natural, social, and built environments. humus hydrologic cycle the cycle or process of evaporation and condensation of water and its distribution across the earth as driven by solar energy. also called the water cycle. hydrophyte see aquatic plant. hydrosphere the combined mass of water found on, under and above the surface of the earth. hydrothermal vent an underwater steaming fissure that has a unique ecosystem. hypoxia reduced oxygen content of air or a body of water, detrimental to aerobic organisms. = = i = = illegitimate receiver an organism that intercepts a signal intended for another organism, to the fitness detriment of either the signaler or the legitimate receiver of the signal. indicator species any living species that defines a trait or characteristic of its environment. the presence and / or abundance of organisms of these species can be used as an indication of the health of a given ecosystem. instinctive behavior the inherent inclination of an organism towards a particular complex behavior. insular biogeography the study of the distributions of biological communities on islands. intermediate disturbance hypothesis a theory that tries to predict how species diversity will change with varying levels of disturbance. interspecific competition a form of competition that occurs between individuals of different species, e. g. when different species try to use the same resources in an environment. contrast intraspecific competition. intertidal zone a coastal area periodically submerged underwater by the action of tides. intraspecific competition a form of competition that occurs between individuals of the same species, e. g. when members of the same species compete for territories or access to mates. compare interspecific competition. invasive species a non - native species whose introduction to an area causes economic or environmental harm or harm to human health. ion exchange a reversible chemical reaction where ions with the same charge are switched. this principle is used in the purification of waste water. = = j = = jungle a dense, wet, humid forest, often tropical, which supports a large variety of wild plant and animal species. = = k = = k - selected
a river is a natural stream of fresh water that flows on land or inside caves towards another body of water at a lower elevation, such as an ocean, lake, or another river. a river may run dry before reaching the end of its course if it runs out of water, or only flow during certain seasons. rivers are regulated by the water cycle, the processes by which water moves around the earth. water first enters rivers through precipitation, whether from rainfall, the runoff of water down a slope, the melting of glaciers or snow, or seepage from aquifers beneath the surface of the earth. rivers flow in channeled watercourses and merge in confluences to form drainage basins, or catchments, areas where surface water eventually flows to a common outlet. rivers have a great effect on the landscape around them. they may regularly overflow their banks and flood the surrounding area, spreading nutrients to the surrounding area. sediment or alluvium carried by rivers shapes the landscape around it, forming deltas and islands where the flow slows down. rivers rarely run in a straight line, instead, they bend or meander ; the locations of a river's banks can change frequently. rivers get their alluvium from erosion, which carves rock into canyons and valleys. rivers have sustained human and animal life for millennia, including the first human civilizations. the organisms that live around or in a river such as fish, aquatic plants, fungi, molluscs, and insects have different roles, including primary production, processing organic matter, predation, parasitism, and decomposition. rivers have produced abundant resources for humans, including food, transportation, drinking water, and recreation. humans have throughout history engineered rivers to prevent flooding, irrigate crops, perform work with water wheels, and produce hydroelectricity from dams. people associate rivers with life and fertility and have strong religious, political, social, and mythological attachments to them. rivers and river ecosystems are threatened by water pollution, climate change, and human activity. the construction of dams, canals, levees, and other engineered structures has eliminated habitats, has caused the extinction of some species, increased nutrient avilability to toxic levels, and lowered the amount of alluvium flowing through rivers. decreased snowfall from climate change has resulted in less water available for rivers during the summer. regulation of pollution, dam removal, and sewage treatment have helped to improve water quality and restore river habitats. certain organisms such as sponges and fungi are useful bioindicators for river
a river is a natural stream of fresh water that flows on land or inside caves towards another body of water at a lower elevation, such as an ocean, lake, or another river. a river may run dry before reaching the end of its course if it runs out of water, or only flow during certain seasons. rivers are regulated by the water cycle, the processes by which water moves around the earth. water first enters rivers through precipitation, whether from rainfall, the runoff of water down a slope, the melting of glaciers or snow, or seepage from aquifers beneath the surface of the earth. rivers flow in channeled watercourses and merge in confluences to form drainage basins, or catchments, areas where surface water eventually flows to a common outlet. rivers have a great effect on the landscape around them. they may regularly overflow their banks and flood the surrounding area, spreading nutrients to the surrounding area. sediment or alluvium carried by rivers shapes the landscape around it, forming deltas and islands where the flow slows down. rivers rarely run in a straight line, instead, they bend or meander ; the locations of a river's banks can change frequently. rivers get their alluvium from erosion, which carves rock into canyons and valleys. rivers have sustained human and animal life for millennia, including the first human civilizations. the organisms that live around or in a river such as fish, aquatic plants, fungi, molluscs, and insects have different roles, including primary production, processing organic matter, predation, parasitism, and decomposition. rivers have produced abundant resources for humans, including food, transportation, drinking water, and recreation. humans have throughout history engineered rivers to prevent flooding, irrigate crops, perform work with water wheels, and produce hydroelectricity from dams. people associate rivers with life and fertility and have strong religious, political, social, and mythological attachments to them. rivers and river ecosystems are threatened by water pollution, climate change, and human activity. the construction of dams, canals, levees, and other engineered structures has eliminated habitats, has caused the extinction of some species, increased nutrient avilability to toxic levels, and lowered the amount of alluvium flowing through rivers. decreased snowfall from climate change has resulted in less water available for rivers during the summer. regulation of pollution, dam removal, and sewage treatment have helped to improve water quality and restore river habitats. certain organisms such as sponges and fungi are useful bioindicators for river
Answer:
|
flowing
| 0.3 |
If water gets _____, it may cause a chemical reaction
0. hotter
1. empty
2. air
3. afraid
and simmering are popular cooking methods that often require immersing food in water or its gaseous state, steam. water is also used for dishwashing. water also plays many critical roles within the field of food science. solutes such as salts and sugars found in water affect the physical properties of water. the boiling and freezing points of water are affected by solutes, as well as air pressure, which is in turn affected by altitude. water boils at lower temperatures with the lower air pressure that occurs at higher elevations. one mole of sucrose ( sugar ) per kilogram of water raises the boiling point of water by 0. 51 Β°c ( 0. 918 Β°f ), and one mole of salt per kg raises the boiling point by 1. 02 Β°c ( 1. 836 Β°f ) ; similarly, increasing the number of dissolved particles lowers water's freezing point. solutes in water also affect water activity that affects many chemical reactions and the growth of microbes in food. water activity can be described as a ratio of the vapor pressure of water in a solution to the vapor pressure of pure water. solutes in water lower water activity β this is important to know because most bacterial growth ceases at low levels of water activity. not only does microbial growth affect the safety of food, but also the preservation and shelf life of food. water hardness is also a critical factor in food processing and may be altered or treated by using a chemical ion exchange system. it can dramatically affect the quality of a product, as well as playing a role in sanitation. water hardness is classified based on concentration of calcium carbonate the water contains. water is classified as soft if it contains less than 100 mg / l ( uk ) or less than 60 mg / l ( us ). according to a report published by the water footprint organization in 2010, a single kilogram of beef requires 15 thousand litres ( 3. 3Γ10 ^ 3 imp gal ; 4. 0Γ10 ^ 3 us gal ) of water ; however, the authors also make clear that this is a global average and circumstantial factors determine the amount of water used in beef production. = = = = medical use = = = = water for injection is on the world health organization's list of essential medicines. = = distribution in nature = = = = = in the universe = = = much of the universe's water is produced as a byproduct of star formation. the formation of stars is accompanied by a strong outward
##tion of water vapor in the breath. with physical exertion and heat exposure, water loss will increase and daily fluid needs may increase as well. humans require water with few impurities. common impurities include metal salts and oxides, including copper, iron, calcium and lead, and harmful bacteria, such as vibrio. some solutes are acceptable and even desirable for taste enhancement and to provide needed electrolytes. the single largest ( by volume ) freshwater resource suitable for drinking is lake baikal in siberia. = = = = washing = = = = = = = = transportation = = = = = = = = chemical uses = = = = water is widely used in chemical reactions as a solvent or reactant and less commonly as a solute or catalyst. in inorganic reactions, water is a common solvent, dissolving many ionic compounds, as well as other polar compounds such as ammonia and compounds closely related to water. in organic reactions, it is not usually used as a reaction solvent, because it does not dissolve the reactants well and is amphoteric ( acidic and basic ) and nucleophilic. nevertheless, these properties are sometimes desirable. also, acceleration of diels - alder reactions by water has been observed. supercritical water has recently been a topic of research. oxygen - saturated supercritical water combusts organic pollutants efficiently. = = = = heat exchange = = = = water and steam are a common fluid used for heat exchange, due to its availability and high heat capacity, both for cooling and heating. cool water may even be naturally available from a lake or the sea. it is especially effective to transport heat through vaporization and condensation of water because of its large latent heat of vaporization. a disadvantage is that metals commonly found in industries such as steel and copper are oxidized faster by untreated water and steam. in almost all thermal power stations, water is used as the working fluid ( used in a closed - loop between boiler, steam turbine, and condenser ), and the coolant ( used to exchange the waste heat to a water body or carry it away by evaporation in a cooling tower ). in the united states, cooling power plants is the largest use of water. in the nuclear power industry, water can also be used as a neutron moderator. in most nuclear reactors, water is both a coolant and a moderator. this provides something of a passive safety measure, as removing the water from the reactor also
3 \ gamma p _ { 0 } \ over \ rho } } } where : Ξ³ { \ displaystyle \ gamma } is the specific heat ratio of the gas r 0 { \ displaystyle r _ { 0 } } is the steady state radius p 0 { \ displaystyle p _ { 0 } } is the steady state pressure Ο { \ displaystyle \ rho } is the mass density of the surrounding liquid for air bubbles in water, smaller bubbles undergo isothermal pulsations. the corresponding equation for small bubbles of surface tension Ο ( and negligible liquid viscosity ) is f 0 = 1 2 Ο r 0 3 p 0 Ο + 4 Ο Ο r 0 { \ displaystyle f _ { 0 } = { 1 \ over 2 \ pi r _ { 0 } } { \ sqrt { { 3p _ { 0 } \ over \ rho } + { 4 \ sigma \ over \ rho r _ { 0 } } } } } excited bubbles trapped underwater are the major source of liquid sounds, such as inside our knuckles during knuckle cracking, and when a rain droplet impacts a surface of water. = = physiology and medicine = = injury by bubble formation and growth in body tissues is the mechanism of decompression sickness, which occurs when supersaturated dissolved inert gases leave the solution as bubbles during decompression. the damage can be due to mechanical deformation of tissues due to bubble growth in situ, or by blocking blood vessels where the bubble has lodged. arterial gas embolism can occur when a gas bubble is introduced to the circulatory system and lodges in a blood vessel that is too small for it to pass through under the available pressure difference. this can occur as a result of decompression after hyperbaric exposure, a lung overexpansion injury, during intravenous fluid administration, or during surgery. = = in foods = = foods containing bubbles includes bread, cakes, cereals and chocolate, and drinks including beer, champagne, mineral water and soft drinks, as well as more experimental applications in foams as made by chefs. = = see also = = antibubble bubble fusion bubble sensor foam minnaert resonance nanobubble sonoluminescence underwater acoustics = = references = = = = sources = = pugh, rj ; hamlett, cae ; fairhurst, dj ( april 2023 ). " a short overview of bubbles in foods and chocolate ". advances in colloid and interface
ideal gas constant 8. 31 j / ( mol * k ) t is temperature in k Ο is cross - sectional area of the surfactant molecules at the surface the surface tension of pure water is dependent on temperature. at room temperature ( 298 k ), it is equal to 71. 97 mn / m = = parameters = = meissner and michaels published the following a constants : = = example = = the following table and diagram show experimentally determined surface tensions in the mixture of water and propionic acid. this example shows a good agreement between the published value a = 2. 6 * 10β3 and the calculated value a = 2. 59 * 10β3 at the smallest given mole fraction of 0. 00861 but at higher concentrations of propionic acid the value of an increases considerably, showing deviations from the predicted value. = = see also = = bohdan szyszkowski = = references = =
heated water can also supply an auxiliary heat exchanger to supply hot water for bathing and washing. = = = = air = = = = warm air systems distribute the heated air through ductwork systems of supply and return air through metal or fiberglass ducts. many systems use the same ducts to distribute air cooled by an evaporator coil for air conditioning. the air supply is normally filtered through air filters to remove dust and pollen particles. = = = dangers = = = the use of furnaces, space heaters, and boilers as a method of indoor heating could result in incomplete combustion and the emission of carbon monoxide, nitrogen oxides, formaldehyde, volatile organic compounds, and other combustion byproducts. incomplete combustion occurs when there is insufficient oxygen ; the inputs are fuels containing various contaminants and the outputs are harmful byproducts, most dangerously carbon monoxide, which is a tasteless and odorless gas with serious adverse health effects. without proper ventilation, carbon monoxide can be lethal at concentrations of 1000 ppm ( 0. 1 % ). however, at several hundred ppm, carbon monoxide exposure induces headaches, fatigue, nausea, and vomiting. carbon monoxide binds with hemoglobin in the blood, forming carboxyhemoglobin, reducing the blood's ability to transport oxygen. the primary health concerns associated with carbon monoxide exposure are its cardiovascular and neurobehavioral effects. carbon monoxide can cause atherosclerosis ( the hardening of arteries ) and can also trigger heart attacks. neurologically, carbon monoxide exposure reduces hand to eye coordination, vigilance, and continuous performance. it can also affect time discrimination. = = ventilation = = ventilation is the process of changing or replacing air in any space to control the temperature or remove any combination of moisture, odors, smoke, heat, dust, airborne bacteria, or carbon dioxide, and to replenish oxygen. it plays a critical role in maintaining a healthy indoor environment by preventing the buildup of harmful pollutants and ensuring the circulation of fresh air. different methods, such as natural ventilation through windows and mechanical ventilation systems, can be used depending on the building design and air quality needs. ventilation often refers to the intentional delivery of the outside air to the building indoor space. it is one of the most important factors for maintaining acceptable indoor air quality in buildings. although ventilation plays a key role in indoor air quality, it may not be sufficient on its own. a
Answer:
|
hotter
| null |
If water gets _____, it may cause a chemical reaction
0. hotter
1. empty
2. air
3. afraid
and simmering are popular cooking methods that often require immersing food in water or its gaseous state, steam. water is also used for dishwashing. water also plays many critical roles within the field of food science. solutes such as salts and sugars found in water affect the physical properties of water. the boiling and freezing points of water are affected by solutes, as well as air pressure, which is in turn affected by altitude. water boils at lower temperatures with the lower air pressure that occurs at higher elevations. one mole of sucrose ( sugar ) per kilogram of water raises the boiling point of water by 0. 51 Β°c ( 0. 918 Β°f ), and one mole of salt per kg raises the boiling point by 1. 02 Β°c ( 1. 836 Β°f ) ; similarly, increasing the number of dissolved particles lowers water's freezing point. solutes in water also affect water activity that affects many chemical reactions and the growth of microbes in food. water activity can be described as a ratio of the vapor pressure of water in a solution to the vapor pressure of pure water. solutes in water lower water activity β this is important to know because most bacterial growth ceases at low levels of water activity. not only does microbial growth affect the safety of food, but also the preservation and shelf life of food. water hardness is also a critical factor in food processing and may be altered or treated by using a chemical ion exchange system. it can dramatically affect the quality of a product, as well as playing a role in sanitation. water hardness is classified based on concentration of calcium carbonate the water contains. water is classified as soft if it contains less than 100 mg / l ( uk ) or less than 60 mg / l ( us ). according to a report published by the water footprint organization in 2010, a single kilogram of beef requires 15 thousand litres ( 3. 3Γ10 ^ 3 imp gal ; 4. 0Γ10 ^ 3 us gal ) of water ; however, the authors also make clear that this is a global average and circumstantial factors determine the amount of water used in beef production. = = = = medical use = = = = water for injection is on the world health organization's list of essential medicines. = = distribution in nature = = = = = in the universe = = = much of the universe's water is produced as a byproduct of star formation. the formation of stars is accompanied by a strong outward
##tion of water vapor in the breath. with physical exertion and heat exposure, water loss will increase and daily fluid needs may increase as well. humans require water with few impurities. common impurities include metal salts and oxides, including copper, iron, calcium and lead, and harmful bacteria, such as vibrio. some solutes are acceptable and even desirable for taste enhancement and to provide needed electrolytes. the single largest ( by volume ) freshwater resource suitable for drinking is lake baikal in siberia. = = = = washing = = = = = = = = transportation = = = = = = = = chemical uses = = = = water is widely used in chemical reactions as a solvent or reactant and less commonly as a solute or catalyst. in inorganic reactions, water is a common solvent, dissolving many ionic compounds, as well as other polar compounds such as ammonia and compounds closely related to water. in organic reactions, it is not usually used as a reaction solvent, because it does not dissolve the reactants well and is amphoteric ( acidic and basic ) and nucleophilic. nevertheless, these properties are sometimes desirable. also, acceleration of diels - alder reactions by water has been observed. supercritical water has recently been a topic of research. oxygen - saturated supercritical water combusts organic pollutants efficiently. = = = = heat exchange = = = = water and steam are a common fluid used for heat exchange, due to its availability and high heat capacity, both for cooling and heating. cool water may even be naturally available from a lake or the sea. it is especially effective to transport heat through vaporization and condensation of water because of its large latent heat of vaporization. a disadvantage is that metals commonly found in industries such as steel and copper are oxidized faster by untreated water and steam. in almost all thermal power stations, water is used as the working fluid ( used in a closed - loop between boiler, steam turbine, and condenser ), and the coolant ( used to exchange the waste heat to a water body or carry it away by evaporation in a cooling tower ). in the united states, cooling power plants is the largest use of water. in the nuclear power industry, water can also be used as a neutron moderator. in most nuclear reactors, water is both a coolant and a moderator. this provides something of a passive safety measure, as removing the water from the reactor also
3 \ gamma p _ { 0 } \ over \ rho } } } where : Ξ³ { \ displaystyle \ gamma } is the specific heat ratio of the gas r 0 { \ displaystyle r _ { 0 } } is the steady state radius p 0 { \ displaystyle p _ { 0 } } is the steady state pressure Ο { \ displaystyle \ rho } is the mass density of the surrounding liquid for air bubbles in water, smaller bubbles undergo isothermal pulsations. the corresponding equation for small bubbles of surface tension Ο ( and negligible liquid viscosity ) is f 0 = 1 2 Ο r 0 3 p 0 Ο + 4 Ο Ο r 0 { \ displaystyle f _ { 0 } = { 1 \ over 2 \ pi r _ { 0 } } { \ sqrt { { 3p _ { 0 } \ over \ rho } + { 4 \ sigma \ over \ rho r _ { 0 } } } } } excited bubbles trapped underwater are the major source of liquid sounds, such as inside our knuckles during knuckle cracking, and when a rain droplet impacts a surface of water. = = physiology and medicine = = injury by bubble formation and growth in body tissues is the mechanism of decompression sickness, which occurs when supersaturated dissolved inert gases leave the solution as bubbles during decompression. the damage can be due to mechanical deformation of tissues due to bubble growth in situ, or by blocking blood vessels where the bubble has lodged. arterial gas embolism can occur when a gas bubble is introduced to the circulatory system and lodges in a blood vessel that is too small for it to pass through under the available pressure difference. this can occur as a result of decompression after hyperbaric exposure, a lung overexpansion injury, during intravenous fluid administration, or during surgery. = = in foods = = foods containing bubbles includes bread, cakes, cereals and chocolate, and drinks including beer, champagne, mineral water and soft drinks, as well as more experimental applications in foams as made by chefs. = = see also = = antibubble bubble fusion bubble sensor foam minnaert resonance nanobubble sonoluminescence underwater acoustics = = references = = = = sources = = pugh, rj ; hamlett, cae ; fairhurst, dj ( april 2023 ). " a short overview of bubbles in foods and chocolate ". advances in colloid and interface
ideal gas constant 8. 31 j / ( mol * k ) t is temperature in k Ο is cross - sectional area of the surfactant molecules at the surface the surface tension of pure water is dependent on temperature. at room temperature ( 298 k ), it is equal to 71. 97 mn / m = = parameters = = meissner and michaels published the following a constants : = = example = = the following table and diagram show experimentally determined surface tensions in the mixture of water and propionic acid. this example shows a good agreement between the published value a = 2. 6 * 10β3 and the calculated value a = 2. 59 * 10β3 at the smallest given mole fraction of 0. 00861 but at higher concentrations of propionic acid the value of an increases considerably, showing deviations from the predicted value. = = see also = = bohdan szyszkowski = = references = =
heated water can also supply an auxiliary heat exchanger to supply hot water for bathing and washing. = = = = air = = = = warm air systems distribute the heated air through ductwork systems of supply and return air through metal or fiberglass ducts. many systems use the same ducts to distribute air cooled by an evaporator coil for air conditioning. the air supply is normally filtered through air filters to remove dust and pollen particles. = = = dangers = = = the use of furnaces, space heaters, and boilers as a method of indoor heating could result in incomplete combustion and the emission of carbon monoxide, nitrogen oxides, formaldehyde, volatile organic compounds, and other combustion byproducts. incomplete combustion occurs when there is insufficient oxygen ; the inputs are fuels containing various contaminants and the outputs are harmful byproducts, most dangerously carbon monoxide, which is a tasteless and odorless gas with serious adverse health effects. without proper ventilation, carbon monoxide can be lethal at concentrations of 1000 ppm ( 0. 1 % ). however, at several hundred ppm, carbon monoxide exposure induces headaches, fatigue, nausea, and vomiting. carbon monoxide binds with hemoglobin in the blood, forming carboxyhemoglobin, reducing the blood's ability to transport oxygen. the primary health concerns associated with carbon monoxide exposure are its cardiovascular and neurobehavioral effects. carbon monoxide can cause atherosclerosis ( the hardening of arteries ) and can also trigger heart attacks. neurologically, carbon monoxide exposure reduces hand to eye coordination, vigilance, and continuous performance. it can also affect time discrimination. = = ventilation = = ventilation is the process of changing or replacing air in any space to control the temperature or remove any combination of moisture, odors, smoke, heat, dust, airborne bacteria, or carbon dioxide, and to replenish oxygen. it plays a critical role in maintaining a healthy indoor environment by preventing the buildup of harmful pollutants and ensuring the circulation of fresh air. different methods, such as natural ventilation through windows and mechanical ventilation systems, can be used depending on the building design and air quality needs. ventilation often refers to the intentional delivery of the outside air to the building indoor space. it is one of the most important factors for maintaining acceptable indoor air quality in buildings. although ventilation plays a key role in indoor air quality, it may not be sufficient on its own. a
Answer:
|
air
| 0.3 |
If a thing reacts in a situation, the most likely reason for the chemical reaction is
0. steam is removed gently
1. upper temps are applied slowly
2. deer are fed tenderly
3. bees are introduced carefully
boltzmann distribution, which establishes that molecules in a given space at a given temperature vary in energy level, and therefore can exist in multiple phases ( solid / liquid / gas ) at a single temperature. heat of vaporization ( or condensation ), which establishes that substances absorb ( or give off ) heat when changing state at a constant temperature. torque and center of mass. capillary action of the wicking felt. wet - bulb temperature : the temperature difference between the head and body depends on the relative humidity of the air. the operation of the bird is also affected by relative humidity. by using a water - ethanol mixture instead of water, the effect of different rates of evaporation can be demonstrated. by considering the difference between the wet and dry bulb temperatures, it is possible to develop a mathematical expression to calculate the maximum work that can be produced from a given amount of water " drunk ". such analysis is based on the definition of the carnot heat engine efficiency and the psychrometric concepts. the drinking bird may also be considered to be an entropy engine driven by the difference of the entropy of liquid water and the entropy of water vapor dispersed in air, that is, the sum of the entropy of evaporation of pure water plus the entropy of dilution of water vapor in air. the evaporation of water is an endothermic process requiring the input of thermal energy or a positive enthalpy flow from the environment. since a spontaneous process requires a negative change in gibbs free energy, the positive enthalpy has to be overcome by the large entropy increase. = = history = = by the 1760s ( or earlier ) german artisans had invented a so - called " pulse hammer " ( pulshammer ). in 1767 benjamin franklin visited germany, saw a pulse hammer, and in 1768, improved it. franklin's pulse hammer consisted of two glass bulbs connected by a u - shaped tube ; one of the bulbs was partially filled with water in equilibrium with its vapor. holding the partially filled bulb in one's hand would cause the water to flow into the empty bulb. in 1872, the italian physicist and engineer enrico bernardi combined three franklin tubes to build a simple heat motor that was powered by evaporation in a way similar to the drinking bird. in 1881 israel l. landis got a patent for a similar oscillating motor. a year later ( 1882 ), the iske brothers got a patent for a similar motor. unlike the drinking bird, the lower tank was
cryochemistry is the study of chemical interactions at temperatures below β150 Β°c ( β238 Β°f ; 123 k ). it is derived from the greek word cryos, meaning'cold '. it overlaps with many other sciences, including chemistry, cryobiology, condensed matter physics, and even astrochemistry. cryochemistry has been a topic of interest since liquid nitrogen, which freezes at β210Β°c, became commonly available. cryogenic - temperature chemical interactions are an important mechanism for studying the detailed pathways of chemical reactions by reducing the confusion introduced by thermal fluctuations. cryochemistry forms the foundation for cryobiology, which uses slowed or stopped biological processes for medical and research purposes. = = low temperature behaviours = = as a material cools, the relative motion of its component molecules / atoms decreases - its temperature decreases. cooling can continue until all motion ceases, and its kinetic energy, or energy of motion, disappears. this condition is known as absolute zero and it forms the basis for the kelvin temperature scale, which measures the temperature above absolute zero. zero degrees celsius ( Β°c ) coincides with 273 kelvin. at absolute zero most elements become a solid, but not all behave as predictably as this ; for instance, helium becomes a highly unusual liquid. the chemistry between substances, however, does not disappear, even near absolute zero temperatures, since separated molecules / atom can always combine to lower their total energy. almost every molecule or element will show different properties at different temperatures ; if cold enough, some functions are lost entirely. cryogenic chemistry can lead to very different results compared with standard chemistry, and new chemical routes to substances may be available at cryogenic temperatures, such as the formation of argon fluorohydride, which is only a stable compound at or below 17 k ( β256. 1 Β°c ). = = methods of cooling = = one method that used to cool molecules to temperatures near absolute zero is laser cooling. in the doppler cooling process, lasers are used to remove energy from electrons of a given molecule to slow or cool the molecule down. this method has applications in quantum mechanics and is related to particle traps and the bose β einstein condensate. all of these methods use a " trap " consisting of lasers pointed at opposite equatorial angles on a specific point in space. the wavelengths from the laser beams eventually hit the gaseous atoms and their outer spinning electrons. this clash of wavelengths decreases the kinetic energy state fraction by fraction to slow or
##mic reactions are combustion, precipitation and crystallization, in which ordered solids are formed from disordered gaseous or liquid phases. in contrast, in endothermic reactions, heat is consumed from the environment. this can occur by increasing the entropy of the system, often through the formation of gaseous or dissolved reaction products, which have higher entropy. since the entropy term in the free - energy change increases with temperature, many endothermic reactions preferably take place at high temperatures. on the contrary, many exothermic reactions such as crystallization occur preferably at lower temperatures. a change in temperature can sometimes reverse the sign of the enthalpy of a reaction, as for the carbon monoxide reduction of molybdenum dioxide : 2 co ( g ) + moo 2 ( s ) 2 co 2 ( g ) + mo ( s ) { \ displaystyle { \ ce { 2co ( g ) + moo2 ( s ) - > 2co2 ( g ) + mo ( s ) } } } ; Ξ΄ h o = + 21. 86 kj at 298 k { \ displaystyle \ delta h ^ { o } = + 21. 86 \ { \ text { kj at 298 k } } } this reaction to form carbon dioxide and molybdenum is endothermic at low temperatures, becoming less so with increasing temperature. Ξ΄hΒ° is zero at 1855 k, and the reaction becomes exothermic above that temperature. changes in temperature can also reverse the direction tendency of a reaction. for example, the water gas shift reaction co ( g ) + h 2 o ( v ) β β co 2 ( g ) + h 2 ( g ) { \ displaystyle { \ ce { co ( g ) + h2o ( { v } ) < = > co2 ( g ) + h2 ( g ) } } } is favored by low temperatures, but its reverse is favored by high temperatures. the shift in reaction direction tendency occurs at 1100 k. reactions can also be characterized by their internal energy change, which takes into account changes in the entropy, volume and chemical potentials. the latter depends, among other things, on the activities of the involved substances. d u = t β
d s β p β
d v + ΞΌ β
d n { \ displaystyle { d } u = t \ cdot { d } s - p \ cdot { d } v + \ mu \ cdot { d } n } u
rises, the bird becomes top heavy and tips over. when the bird tips over, the bottom end of the neck tube rises above the surface of the liquid in the bottom bulb. a bubble of warm vapor rises up the tube through this gap, displacing liquid as it goes. liquid flows back to the bottom bulb ( the toy is designed so that when it has tipped over the neck's tilt allows this ). pressure equalizes between top and bottom bulbs. the weight of the liquid in the bottom bulb restores the bird to its vertical position. the liquid in the bottom bulb is heated by ambient air, which is at a temperature slightly higher than the temperature of the bird's head. if a glass of water is placed so that the beak dips into it on its descent, the bird will continue to absorb water and the cycle will continue as long as there is enough water in the glass to keep the head wet. however, the bird will continue to dip even without a source of water, as long as the head is wet, or as long as a temperature differential is maintained between the head and body. this differential can be generated without evaporative cooling in the head ; for instance, a heat source directed at the bottom bulb will create a pressure differential between top and bottom that will drive the engine. the ultimate source of energy is the temperature gradient between the toy's head and base ; the toy is not a perpetual motion machine. = = physical and chemical principles = = the drinking bird is an exhibition of several physical laws and is therefore a staple of basic chemistry and physics education. these include : the dichloromethane with a low boiling point ( 39. 6 Β°c ( 103. 3 Β°f ) under standard pressure po = 105 pa β as the drinking bird is first evacuated, partially filled and sealed, the pressure and thus the boiling point in the drinking bird will be different ), gives the heat engine the ability to extract motion from low temperatures. the drinking bird is a heat engine that works at room temperature. the combined gas law, which establishes a proportional relationship between temperature and pressure exerted by a gas in a constant volume. the ideal gas law, which establishes a proportional relationship between number of gas particles and pressure in a constant volume. the maxwell β boltzmann distribution, which establishes that molecules in a given space at a given temperature vary in energy level, and therefore can exist in multiple phases ( solid / liquid / gas ) at a single temperature. heat of vaporization ( or condensation
and simmering are popular cooking methods that often require immersing food in water or its gaseous state, steam. water is also used for dishwashing. water also plays many critical roles within the field of food science. solutes such as salts and sugars found in water affect the physical properties of water. the boiling and freezing points of water are affected by solutes, as well as air pressure, which is in turn affected by altitude. water boils at lower temperatures with the lower air pressure that occurs at higher elevations. one mole of sucrose ( sugar ) per kilogram of water raises the boiling point of water by 0. 51 Β°c ( 0. 918 Β°f ), and one mole of salt per kg raises the boiling point by 1. 02 Β°c ( 1. 836 Β°f ) ; similarly, increasing the number of dissolved particles lowers water's freezing point. solutes in water also affect water activity that affects many chemical reactions and the growth of microbes in food. water activity can be described as a ratio of the vapor pressure of water in a solution to the vapor pressure of pure water. solutes in water lower water activity β this is important to know because most bacterial growth ceases at low levels of water activity. not only does microbial growth affect the safety of food, but also the preservation and shelf life of food. water hardness is also a critical factor in food processing and may be altered or treated by using a chemical ion exchange system. it can dramatically affect the quality of a product, as well as playing a role in sanitation. water hardness is classified based on concentration of calcium carbonate the water contains. water is classified as soft if it contains less than 100 mg / l ( uk ) or less than 60 mg / l ( us ). according to a report published by the water footprint organization in 2010, a single kilogram of beef requires 15 thousand litres ( 3. 3Γ10 ^ 3 imp gal ; 4. 0Γ10 ^ 3 us gal ) of water ; however, the authors also make clear that this is a global average and circumstantial factors determine the amount of water used in beef production. = = = = medical use = = = = water for injection is on the world health organization's list of essential medicines. = = distribution in nature = = = = = in the universe = = = much of the universe's water is produced as a byproduct of star formation. the formation of stars is accompanied by a strong outward
Answer:
|
upper temps are applied slowly
| null |
If a thing reacts in a situation, the most likely reason for the chemical reaction is
0. steam is removed gently
1. upper temps are applied slowly
2. deer are fed tenderly
3. bees are introduced carefully
boltzmann distribution, which establishes that molecules in a given space at a given temperature vary in energy level, and therefore can exist in multiple phases ( solid / liquid / gas ) at a single temperature. heat of vaporization ( or condensation ), which establishes that substances absorb ( or give off ) heat when changing state at a constant temperature. torque and center of mass. capillary action of the wicking felt. wet - bulb temperature : the temperature difference between the head and body depends on the relative humidity of the air. the operation of the bird is also affected by relative humidity. by using a water - ethanol mixture instead of water, the effect of different rates of evaporation can be demonstrated. by considering the difference between the wet and dry bulb temperatures, it is possible to develop a mathematical expression to calculate the maximum work that can be produced from a given amount of water " drunk ". such analysis is based on the definition of the carnot heat engine efficiency and the psychrometric concepts. the drinking bird may also be considered to be an entropy engine driven by the difference of the entropy of liquid water and the entropy of water vapor dispersed in air, that is, the sum of the entropy of evaporation of pure water plus the entropy of dilution of water vapor in air. the evaporation of water is an endothermic process requiring the input of thermal energy or a positive enthalpy flow from the environment. since a spontaneous process requires a negative change in gibbs free energy, the positive enthalpy has to be overcome by the large entropy increase. = = history = = by the 1760s ( or earlier ) german artisans had invented a so - called " pulse hammer " ( pulshammer ). in 1767 benjamin franklin visited germany, saw a pulse hammer, and in 1768, improved it. franklin's pulse hammer consisted of two glass bulbs connected by a u - shaped tube ; one of the bulbs was partially filled with water in equilibrium with its vapor. holding the partially filled bulb in one's hand would cause the water to flow into the empty bulb. in 1872, the italian physicist and engineer enrico bernardi combined three franklin tubes to build a simple heat motor that was powered by evaporation in a way similar to the drinking bird. in 1881 israel l. landis got a patent for a similar oscillating motor. a year later ( 1882 ), the iske brothers got a patent for a similar motor. unlike the drinking bird, the lower tank was
cryochemistry is the study of chemical interactions at temperatures below β150 Β°c ( β238 Β°f ; 123 k ). it is derived from the greek word cryos, meaning'cold '. it overlaps with many other sciences, including chemistry, cryobiology, condensed matter physics, and even astrochemistry. cryochemistry has been a topic of interest since liquid nitrogen, which freezes at β210Β°c, became commonly available. cryogenic - temperature chemical interactions are an important mechanism for studying the detailed pathways of chemical reactions by reducing the confusion introduced by thermal fluctuations. cryochemistry forms the foundation for cryobiology, which uses slowed or stopped biological processes for medical and research purposes. = = low temperature behaviours = = as a material cools, the relative motion of its component molecules / atoms decreases - its temperature decreases. cooling can continue until all motion ceases, and its kinetic energy, or energy of motion, disappears. this condition is known as absolute zero and it forms the basis for the kelvin temperature scale, which measures the temperature above absolute zero. zero degrees celsius ( Β°c ) coincides with 273 kelvin. at absolute zero most elements become a solid, but not all behave as predictably as this ; for instance, helium becomes a highly unusual liquid. the chemistry between substances, however, does not disappear, even near absolute zero temperatures, since separated molecules / atom can always combine to lower their total energy. almost every molecule or element will show different properties at different temperatures ; if cold enough, some functions are lost entirely. cryogenic chemistry can lead to very different results compared with standard chemistry, and new chemical routes to substances may be available at cryogenic temperatures, such as the formation of argon fluorohydride, which is only a stable compound at or below 17 k ( β256. 1 Β°c ). = = methods of cooling = = one method that used to cool molecules to temperatures near absolute zero is laser cooling. in the doppler cooling process, lasers are used to remove energy from electrons of a given molecule to slow or cool the molecule down. this method has applications in quantum mechanics and is related to particle traps and the bose β einstein condensate. all of these methods use a " trap " consisting of lasers pointed at opposite equatorial angles on a specific point in space. the wavelengths from the laser beams eventually hit the gaseous atoms and their outer spinning electrons. this clash of wavelengths decreases the kinetic energy state fraction by fraction to slow or
##mic reactions are combustion, precipitation and crystallization, in which ordered solids are formed from disordered gaseous or liquid phases. in contrast, in endothermic reactions, heat is consumed from the environment. this can occur by increasing the entropy of the system, often through the formation of gaseous or dissolved reaction products, which have higher entropy. since the entropy term in the free - energy change increases with temperature, many endothermic reactions preferably take place at high temperatures. on the contrary, many exothermic reactions such as crystallization occur preferably at lower temperatures. a change in temperature can sometimes reverse the sign of the enthalpy of a reaction, as for the carbon monoxide reduction of molybdenum dioxide : 2 co ( g ) + moo 2 ( s ) 2 co 2 ( g ) + mo ( s ) { \ displaystyle { \ ce { 2co ( g ) + moo2 ( s ) - > 2co2 ( g ) + mo ( s ) } } } ; Ξ΄ h o = + 21. 86 kj at 298 k { \ displaystyle \ delta h ^ { o } = + 21. 86 \ { \ text { kj at 298 k } } } this reaction to form carbon dioxide and molybdenum is endothermic at low temperatures, becoming less so with increasing temperature. Ξ΄hΒ° is zero at 1855 k, and the reaction becomes exothermic above that temperature. changes in temperature can also reverse the direction tendency of a reaction. for example, the water gas shift reaction co ( g ) + h 2 o ( v ) β β co 2 ( g ) + h 2 ( g ) { \ displaystyle { \ ce { co ( g ) + h2o ( { v } ) < = > co2 ( g ) + h2 ( g ) } } } is favored by low temperatures, but its reverse is favored by high temperatures. the shift in reaction direction tendency occurs at 1100 k. reactions can also be characterized by their internal energy change, which takes into account changes in the entropy, volume and chemical potentials. the latter depends, among other things, on the activities of the involved substances. d u = t β
d s β p β
d v + ΞΌ β
d n { \ displaystyle { d } u = t \ cdot { d } s - p \ cdot { d } v + \ mu \ cdot { d } n } u
rises, the bird becomes top heavy and tips over. when the bird tips over, the bottom end of the neck tube rises above the surface of the liquid in the bottom bulb. a bubble of warm vapor rises up the tube through this gap, displacing liquid as it goes. liquid flows back to the bottom bulb ( the toy is designed so that when it has tipped over the neck's tilt allows this ). pressure equalizes between top and bottom bulbs. the weight of the liquid in the bottom bulb restores the bird to its vertical position. the liquid in the bottom bulb is heated by ambient air, which is at a temperature slightly higher than the temperature of the bird's head. if a glass of water is placed so that the beak dips into it on its descent, the bird will continue to absorb water and the cycle will continue as long as there is enough water in the glass to keep the head wet. however, the bird will continue to dip even without a source of water, as long as the head is wet, or as long as a temperature differential is maintained between the head and body. this differential can be generated without evaporative cooling in the head ; for instance, a heat source directed at the bottom bulb will create a pressure differential between top and bottom that will drive the engine. the ultimate source of energy is the temperature gradient between the toy's head and base ; the toy is not a perpetual motion machine. = = physical and chemical principles = = the drinking bird is an exhibition of several physical laws and is therefore a staple of basic chemistry and physics education. these include : the dichloromethane with a low boiling point ( 39. 6 Β°c ( 103. 3 Β°f ) under standard pressure po = 105 pa β as the drinking bird is first evacuated, partially filled and sealed, the pressure and thus the boiling point in the drinking bird will be different ), gives the heat engine the ability to extract motion from low temperatures. the drinking bird is a heat engine that works at room temperature. the combined gas law, which establishes a proportional relationship between temperature and pressure exerted by a gas in a constant volume. the ideal gas law, which establishes a proportional relationship between number of gas particles and pressure in a constant volume. the maxwell β boltzmann distribution, which establishes that molecules in a given space at a given temperature vary in energy level, and therefore can exist in multiple phases ( solid / liquid / gas ) at a single temperature. heat of vaporization ( or condensation
and simmering are popular cooking methods that often require immersing food in water or its gaseous state, steam. water is also used for dishwashing. water also plays many critical roles within the field of food science. solutes such as salts and sugars found in water affect the physical properties of water. the boiling and freezing points of water are affected by solutes, as well as air pressure, which is in turn affected by altitude. water boils at lower temperatures with the lower air pressure that occurs at higher elevations. one mole of sucrose ( sugar ) per kilogram of water raises the boiling point of water by 0. 51 Β°c ( 0. 918 Β°f ), and one mole of salt per kg raises the boiling point by 1. 02 Β°c ( 1. 836 Β°f ) ; similarly, increasing the number of dissolved particles lowers water's freezing point. solutes in water also affect water activity that affects many chemical reactions and the growth of microbes in food. water activity can be described as a ratio of the vapor pressure of water in a solution to the vapor pressure of pure water. solutes in water lower water activity β this is important to know because most bacterial growth ceases at low levels of water activity. not only does microbial growth affect the safety of food, but also the preservation and shelf life of food. water hardness is also a critical factor in food processing and may be altered or treated by using a chemical ion exchange system. it can dramatically affect the quality of a product, as well as playing a role in sanitation. water hardness is classified based on concentration of calcium carbonate the water contains. water is classified as soft if it contains less than 100 mg / l ( uk ) or less than 60 mg / l ( us ). according to a report published by the water footprint organization in 2010, a single kilogram of beef requires 15 thousand litres ( 3. 3Γ10 ^ 3 imp gal ; 4. 0Γ10 ^ 3 us gal ) of water ; however, the authors also make clear that this is a global average and circumstantial factors determine the amount of water used in beef production. = = = = medical use = = = = water for injection is on the world health organization's list of essential medicines. = = distribution in nature = = = = = in the universe = = = much of the universe's water is produced as a byproduct of star formation. the formation of stars is accompanied by a strong outward
Answer:
|
deer are fed tenderly
| 0.3 |
A plane travels through what?
0. gas layers
1. plains
2. oceans
3. time
the surface layer is the layer of a turbulent fluid most affected by interaction with a solid surface or the surface separating a gas and a liquid where the characteristics of the turbulence depend on distance from the interface. surface layers are characterized by large normal gradients of tangential velocity and large concentration gradients of any substances ( temperature, moisture, sediments et cetera ) transported to or from the interface. the term boundary layer is used in meteorology and physical oceanography. the atmospheric surface layer is the lowest part of the atmospheric boundary layer ( typically the bottom 10 % where the log wind profile is valid ). the ocean has two surface layers : the benthic, found immediately above the sea floor, and the marine surface layer, at the air - sea interface. = = mathematical formulation = = a simple model of the surface layer can be derived by first examining the turbulent momentum flux through a surface. using reynolds decomposition to express the horizontal flow in the x { \ displaystyle x } direction as the sum of a slowly varying component, u { \ displaystyle { \ overline { u } } }, and a turbulent component, u β² { \ displaystyle u'}, u = u + u β² { \ displaystyle u = { \ overline { u } } + u'} and the vertical flow, w { \ displaystyle w }, in an analogous fashion, w = w + w β² { \ displaystyle w = { \ overline { w } } + w'} we can express the flux of turbulent momentum through a surface, u β { \ displaystyle u _ { * } }, as the time - averaged magnitude of vertical turbulent transport of horizontal turbulent momentum, u β² w β² { \ displaystyle u'w'} : u β 2 = | ( u β² w β² ) s | { \ displaystyle u _ { * } ^ { 2 } = \ left | { \ overline { ( u'w') _ { s } } } \ right | }. if the flow is homogeneous within the region, we can set the product of the vertical gradient of the mean horizontal flow and the eddy viscosity coefficient k m { \ displaystyle k _ { m } } equal to u β 2 { \ displaystyle u _ { * } ^ { 2 } } : k m β u β z = u β 2 { \ displaystyle k _ { m } { \ frac { \ partial { \ overline { u } } } { \
youtube video ) from summit to seafloor β lifted weight as a function of altitude and depth by rolf steinegger joukowski transform interactive webapp archived october 19, 2019, at the wayback machine how planes fly archived june 11, 2021, at the wayback machine youtube video presentation by krzysztof fidkowski, associate professor of aerospace engineering at the university of michigan
sound barrier. however, aircraft design progressed sufficiently to produce the bell x - 1. piloted by chuck yeager, the x - 1 officially achieved supersonic speed in october 1947. historically, two parallel paths of research have been followed in order to further gas dynamics knowledge. experimental gas dynamics undertakes wind tunnel model experiments and experiments in shock tubes and ballistic ranges with the use of optical techniques to document the findings. theoretical gas dynamics considers the equations of motion applied to a variable - density gas, and their solutions. much of basic gas dynamics is analytical, but in the modern era computational fluid dynamics applies computing power to solve the otherwise - intractable nonlinear partial differential equations of compressible flow for specific geometries and flow characteristics. = = introductory concepts = = there are several important assumptions involved in the underlying theory of compressible flow. all fluids are composed of molecules, but tracking a huge number of individual molecules in a flow ( for example at atmospheric pressure ) is unnecessary. instead, the continuum assumption allows us to consider a flowing gas as a continuous substance except at low densities. this assumption provides a huge simplification which is accurate for most gas - dynamic problems. only in the low - density realm of rarefied gas dynamics does the motion of individual molecules become important. a related assumption is the no - slip condition where the flow velocity at a solid surface is presumed equal to the velocity of the surface itself, which is a direct consequence of assuming continuum flow. the no - slip condition implies that the flow is viscous, and as a result a boundary layer forms on bodies traveling through the air at high speeds, much as it does in low - speed flow. most problems in incompressible flow involve only two unknowns : pressure and velocity, which are typically found by solving the two equations that describe conservation of mass and of linear momentum, with the fluid density presumed constant. in compressible flow, however, the gas density and temperature also become variables. this requires two more equations in order to solve compressible - flow problems : an equation of state for the gas and a conservation of energy equation. for the majority of gas - dynamic problems, the simple ideal gas law is the appropriate state equation. otherwise, more complex equations of state must be considered and the so - called non ideal compressible fluids dynamics ( nicfd ) establishes. fluid dynamics problems have two overall types of references frames, called lagrangian and eulerian ( see joseph - louis lagrange and leonhard euler ). the
setup, let u 0 { \ displaystyle u _ { 0 } } be the forward velocity of the gas at a horizontal flat layer ( labeled as y = 0 { \ displaystyle y = 0 } ) ; u 0 { \ displaystyle u _ { 0 } } is along the horizontal direction. the number of molecules arriving at the area d a { \ displaystyle da } on one side of the gas layer, with speed v { \ displaystyle v } at angle ΞΈ { \ displaystyle \ theta } from the normal, in time interval d t { \ displaystyle dt } is n v cos ( ΞΈ ) d a d t Γ ( m 2 Ο k b t ) 3 / 2 e β m v 2 2 k b t ( v 2 sin ΞΈ d v d ΞΈ d ) { \ displaystyle nv \ cos ( { \ theta } ) \, da \, dt \ times \ left ( { \ frac { m } { 2 \ pi k _ { \ mathrm { b } } t } } \ right ) ^ { 3 / 2 } \, e ^ { - { \ frac { mv ^ { 2 } } { 2k _ { \ mathrm { b } } t } } } ( v ^ { 2 } \ sin { \ theta } \, dv \, d \ theta \, d \ phi ) } these molecules made their last collision at y = Β± β cos ΞΈ { \ displaystyle y = \ pm \ ell \ cos \ theta }, where β { \ displaystyle \ ell } is the mean free path. each molecule will contribute a forward momentum of p x Β± = m ( u 0 Β± β cos ΞΈ d u d y ), { \ displaystyle p _ { x } ^ { \ pm } = m \ left ( u _ { 0 } \ pm \ ell \ cos \ theta { \ frac { du } { dy } } \ right ), } where plus sign applies to molecules from above, and minus sign below. note that the forward velocity gradient d u / d y { \ displaystyle du / dy } can be considered to be constant over a distance of mean free path. integrating over all appropriate velocities within the constraint v > 0 { \ displaystyle v > 0 }, 0 < ΞΈ < Ο 2 { \ textstyle 0 < \ theta < { \ frac { \ pi } { 2 } } }, 0 <
at the edge of the future border between the two plates. greece lacked its current projection into the aegean ; in fact, the aegean was not there. at this stage, as early as 30 mya in the oligocene, the mainland of the balkans had been formed by successive waves of subduction of the african plate under the eurasian, called " thrusts " from their thrusting of the eurasian plate to the ne. the various forearcs, or " thrust sheets, " created by this thrusting had moved to the north and had docked against the preceding, closing the ancient seas between them. each forearc was a complex of folds, or " nappes, " raised by compression ( or " shortening of the crust " ), which had a tendency to fall over, creating tilted layers exposed later in highlands. the general hypothesis is that throughout these successive subductions there was only one subduction zone acting continuously to convey ( as on a conveyor belt ) and emplace ( obduct ) microcontinents broken from the african slab. between each microcontinent was a local ocean, which was subducted and closed in turn : in the cenozoic the vardar, 1, 000 kilometres ( 620 mi ) subducted ; the pindos, 500 kilometres ( 310 mi ) subducted ; and the eastern mediterranean, still being suducted. between the vardar and the pindos was the pelagian microcontinent ; between the pindos and the mediterranean was the apulian ( or adriatic ) microcontinent, with 900 kilometres ( 560 mi ) subducted for the two, amounting to a closure of 2, 400 kilometres ( 1, 500 mi ) between africa and eurasia. individual subductions thus varied between oceanic and continental, the current being oceanic. this hellenic orogeny to this point was part of the alpine orogeny. the newly formed alps connected to the dinaric alps, which were continuous with a chain called the outer hellenides, the last to form. each former forearc was its own type of rock, or facies. mainland greece thus consists geologically of strips, or isopic zones ( " same facies " ), or " tectono - stratigraphic units " of distinct rock trending from nw to se. the regime through the oligocene, evidenced in the zone structure of greece, was compressional. the subduction was in the trench and its forearc was the edge of the overriding plate (
Answer:
|
gas layers
| null |
A plane travels through what?
0. gas layers
1. plains
2. oceans
3. time
the surface layer is the layer of a turbulent fluid most affected by interaction with a solid surface or the surface separating a gas and a liquid where the characteristics of the turbulence depend on distance from the interface. surface layers are characterized by large normal gradients of tangential velocity and large concentration gradients of any substances ( temperature, moisture, sediments et cetera ) transported to or from the interface. the term boundary layer is used in meteorology and physical oceanography. the atmospheric surface layer is the lowest part of the atmospheric boundary layer ( typically the bottom 10 % where the log wind profile is valid ). the ocean has two surface layers : the benthic, found immediately above the sea floor, and the marine surface layer, at the air - sea interface. = = mathematical formulation = = a simple model of the surface layer can be derived by first examining the turbulent momentum flux through a surface. using reynolds decomposition to express the horizontal flow in the x { \ displaystyle x } direction as the sum of a slowly varying component, u { \ displaystyle { \ overline { u } } }, and a turbulent component, u β² { \ displaystyle u'}, u = u + u β² { \ displaystyle u = { \ overline { u } } + u'} and the vertical flow, w { \ displaystyle w }, in an analogous fashion, w = w + w β² { \ displaystyle w = { \ overline { w } } + w'} we can express the flux of turbulent momentum through a surface, u β { \ displaystyle u _ { * } }, as the time - averaged magnitude of vertical turbulent transport of horizontal turbulent momentum, u β² w β² { \ displaystyle u'w'} : u β 2 = | ( u β² w β² ) s | { \ displaystyle u _ { * } ^ { 2 } = \ left | { \ overline { ( u'w') _ { s } } } \ right | }. if the flow is homogeneous within the region, we can set the product of the vertical gradient of the mean horizontal flow and the eddy viscosity coefficient k m { \ displaystyle k _ { m } } equal to u β 2 { \ displaystyle u _ { * } ^ { 2 } } : k m β u β z = u β 2 { \ displaystyle k _ { m } { \ frac { \ partial { \ overline { u } } } { \
youtube video ) from summit to seafloor β lifted weight as a function of altitude and depth by rolf steinegger joukowski transform interactive webapp archived october 19, 2019, at the wayback machine how planes fly archived june 11, 2021, at the wayback machine youtube video presentation by krzysztof fidkowski, associate professor of aerospace engineering at the university of michigan
sound barrier. however, aircraft design progressed sufficiently to produce the bell x - 1. piloted by chuck yeager, the x - 1 officially achieved supersonic speed in october 1947. historically, two parallel paths of research have been followed in order to further gas dynamics knowledge. experimental gas dynamics undertakes wind tunnel model experiments and experiments in shock tubes and ballistic ranges with the use of optical techniques to document the findings. theoretical gas dynamics considers the equations of motion applied to a variable - density gas, and their solutions. much of basic gas dynamics is analytical, but in the modern era computational fluid dynamics applies computing power to solve the otherwise - intractable nonlinear partial differential equations of compressible flow for specific geometries and flow characteristics. = = introductory concepts = = there are several important assumptions involved in the underlying theory of compressible flow. all fluids are composed of molecules, but tracking a huge number of individual molecules in a flow ( for example at atmospheric pressure ) is unnecessary. instead, the continuum assumption allows us to consider a flowing gas as a continuous substance except at low densities. this assumption provides a huge simplification which is accurate for most gas - dynamic problems. only in the low - density realm of rarefied gas dynamics does the motion of individual molecules become important. a related assumption is the no - slip condition where the flow velocity at a solid surface is presumed equal to the velocity of the surface itself, which is a direct consequence of assuming continuum flow. the no - slip condition implies that the flow is viscous, and as a result a boundary layer forms on bodies traveling through the air at high speeds, much as it does in low - speed flow. most problems in incompressible flow involve only two unknowns : pressure and velocity, which are typically found by solving the two equations that describe conservation of mass and of linear momentum, with the fluid density presumed constant. in compressible flow, however, the gas density and temperature also become variables. this requires two more equations in order to solve compressible - flow problems : an equation of state for the gas and a conservation of energy equation. for the majority of gas - dynamic problems, the simple ideal gas law is the appropriate state equation. otherwise, more complex equations of state must be considered and the so - called non ideal compressible fluids dynamics ( nicfd ) establishes. fluid dynamics problems have two overall types of references frames, called lagrangian and eulerian ( see joseph - louis lagrange and leonhard euler ). the
setup, let u 0 { \ displaystyle u _ { 0 } } be the forward velocity of the gas at a horizontal flat layer ( labeled as y = 0 { \ displaystyle y = 0 } ) ; u 0 { \ displaystyle u _ { 0 } } is along the horizontal direction. the number of molecules arriving at the area d a { \ displaystyle da } on one side of the gas layer, with speed v { \ displaystyle v } at angle ΞΈ { \ displaystyle \ theta } from the normal, in time interval d t { \ displaystyle dt } is n v cos ( ΞΈ ) d a d t Γ ( m 2 Ο k b t ) 3 / 2 e β m v 2 2 k b t ( v 2 sin ΞΈ d v d ΞΈ d ) { \ displaystyle nv \ cos ( { \ theta } ) \, da \, dt \ times \ left ( { \ frac { m } { 2 \ pi k _ { \ mathrm { b } } t } } \ right ) ^ { 3 / 2 } \, e ^ { - { \ frac { mv ^ { 2 } } { 2k _ { \ mathrm { b } } t } } } ( v ^ { 2 } \ sin { \ theta } \, dv \, d \ theta \, d \ phi ) } these molecules made their last collision at y = Β± β cos ΞΈ { \ displaystyle y = \ pm \ ell \ cos \ theta }, where β { \ displaystyle \ ell } is the mean free path. each molecule will contribute a forward momentum of p x Β± = m ( u 0 Β± β cos ΞΈ d u d y ), { \ displaystyle p _ { x } ^ { \ pm } = m \ left ( u _ { 0 } \ pm \ ell \ cos \ theta { \ frac { du } { dy } } \ right ), } where plus sign applies to molecules from above, and minus sign below. note that the forward velocity gradient d u / d y { \ displaystyle du / dy } can be considered to be constant over a distance of mean free path. integrating over all appropriate velocities within the constraint v > 0 { \ displaystyle v > 0 }, 0 < ΞΈ < Ο 2 { \ textstyle 0 < \ theta < { \ frac { \ pi } { 2 } } }, 0 <
at the edge of the future border between the two plates. greece lacked its current projection into the aegean ; in fact, the aegean was not there. at this stage, as early as 30 mya in the oligocene, the mainland of the balkans had been formed by successive waves of subduction of the african plate under the eurasian, called " thrusts " from their thrusting of the eurasian plate to the ne. the various forearcs, or " thrust sheets, " created by this thrusting had moved to the north and had docked against the preceding, closing the ancient seas between them. each forearc was a complex of folds, or " nappes, " raised by compression ( or " shortening of the crust " ), which had a tendency to fall over, creating tilted layers exposed later in highlands. the general hypothesis is that throughout these successive subductions there was only one subduction zone acting continuously to convey ( as on a conveyor belt ) and emplace ( obduct ) microcontinents broken from the african slab. between each microcontinent was a local ocean, which was subducted and closed in turn : in the cenozoic the vardar, 1, 000 kilometres ( 620 mi ) subducted ; the pindos, 500 kilometres ( 310 mi ) subducted ; and the eastern mediterranean, still being suducted. between the vardar and the pindos was the pelagian microcontinent ; between the pindos and the mediterranean was the apulian ( or adriatic ) microcontinent, with 900 kilometres ( 560 mi ) subducted for the two, amounting to a closure of 2, 400 kilometres ( 1, 500 mi ) between africa and eurasia. individual subductions thus varied between oceanic and continental, the current being oceanic. this hellenic orogeny to this point was part of the alpine orogeny. the newly formed alps connected to the dinaric alps, which were continuous with a chain called the outer hellenides, the last to form. each former forearc was its own type of rock, or facies. mainland greece thus consists geologically of strips, or isopic zones ( " same facies " ), or " tectono - stratigraphic units " of distinct rock trending from nw to se. the regime through the oligocene, evidenced in the zone structure of greece, was compressional. the subduction was in the trench and its forearc was the edge of the overriding plate (
Answer:
|
plains
| 0.3 |
A fixed wing aircraft can fly
0. high in space
1. in the troposphere
2. inside an amoeba
3. deep underwater
air by emulating the flight mechanisms of insects and birds. these microrobots have to overcome the issues related to lift, thrust, and movement that are challenging to accomplish at such a small scale where most aerodynamic theories must be modified. active flight is the most energy - intensive mode of locomotion, as the microrobot must lift its body weight while propelling itself forward. to achieve this function, these microrobots mimic the movement of insect wings and generate the necessary airflow for producing lift and thrust. miniaturized wings of the robots are actuated with piezoelectric materials, which offer better control of wing kinematics and flight dynamics. to calculate the necessary aerodynamic power for maintaining a hover with flapping wings, the primary physical equation is expressed as m g = 2 β Ο β l 2 β β Ο
i 2 { \ displaystyle mg = 2 * \ rho * l ^ { 2 } * \ phi * \ upsilon _ { i } ^ { 2 } } where m is the body mass, l is the wing length, Ο represents the wing flapping amplitude in radians, Ο indicates the air density, and vi corresponds to the induced air speed surrounding the body, a consequence of the wings'flapping and rotation movements. this equation illustrates that a small insect or robotic device must impart sufficient momentum to the surrounding air to counterbalance its own weight. one example of a flying microrobot that utilizes flying locomotion is the robobee and delfly nimble, which, regarding flight dynamics, emulate bees and fruit flies, respectively. harvard university invented the robobee, a miniature robot that mimics a bee fly, takes off and lands like one, and moves around confined spaces. it can be used in self - driving pollination and search operations for missing people and things. the delfly nimble, developed by the delft university of technology, is one of the most agile micro aerial vehicles that can mimic the maneuverability of a fruit fly by doing different tricks due to its minimal weight and advanced control mechanisms. = = types and applications = = due to their small size, microbots are potentially very cheap, and could be used in large numbers ( swarm robotics ) to explore environments which are too small or too dangerous for people or larger robots. it is expected that microbots will be useful in applications such as looking for survivors in collapsed buildings after an earthquake or crawling through the digestive tract. what microbots lack in brawn or computational power
when the vehicle reaches the top and bottom depth limits of its operating envelope. without a buoyancy engine, an underwater glider could be used once and then deploy a package that would float to the surface where it can be retrieved, or drop ballast, with the same effect. with the addition of a buoyancy engine, the underwater glider becomes a more viable tool as it can stay in operation longer and can be reused. an underwater glider, like an aircraft glider, loses altitude as it moves forward. in the case of an underwater glider, its depth increases. eventually, any glider will touch the ground. with a gliding aircraft, this is not much of an issue since they are expected to land and are reusable when they do so. this is not true for an underwater glider. if an underwater glider were to land on the ocean floor, it is essentially lost. since a buoyancy engine allows a glider to change its density, the glider can glide in two directions. it can glide down like an aircraft, or it can glide up if it makes itself less dense than the water around it. in this way, as long as the buoyancy engine remains active, and power is available, an underwater glider can continue to operate. the actual operation of a buoyancy engine occurs through a complex system of tubing, valves, and sensors. when a glider equipped with a buoyancy engine is deployed, the glider will increase its density to sink to an appropriate depth at which to start its mission. once at that depth, the glider will begin the mission and the buoyancy engine will adjust the density to a value that is efficient for gliding. when a predetermined depth has been reached, the buoyancy engine will decrease density and this will cause the glider to glide back towards the surface. in this way, the underwater glider remains in operation between two preset depths. the mechanism used to modify buoyancy for this purpose is often a variable buoyancy pressure vessel. = = application = = the buoyancy engine, when combined with the underwater glider, gives scientists and other individuals or organizations access to hardware to survey the ocean depths. for instance, the buoyancy engine, since it is used on underwater gliders and extends the capabilities of such craft, would be able to more effectively map the ocean floor. the use of the buoyancy engine has other effects as well. it could be used to improve the detection of underwater stores of oil. in addition, since the operational range of underwater
youtube video ) from summit to seafloor β lifted weight as a function of altitude and depth by rolf steinegger joukowski transform interactive webapp archived october 19, 2019, at the wayback machine how planes fly archived june 11, 2021, at the wayback machine youtube video presentation by krzysztof fidkowski, associate professor of aerospace engineering at the university of michigan
operator deliberately flew the uav 2. 5 miles away from himself and was unaware of the helicopters'presence. the operator did not know of the collision until contacted by the ntsb and when interviewed by them showed only a general cursory awareness of the regulations. there was also a temporary flight restriction in place, from which the black hawk ( but not the uav ) was exempt. uavs are prohibited from flying beyond the pilot's line of sight under faa regulations. 12 october 2017 a beechcraft king air a100 of skyjet aviation collided with a uav as the former was approaching jean lesage airport near quebec city, canada. the aircraft landed safely despite its wing being hit. the aircraft had flown from rouyn - noranda airport to jean lesage airport with six passengers and two crew. a spokeswoman for the quebec city police said that neither the uav nor the operator had been found. it had been flying at 1500 feet β five times the maximum altitude that uavs are permitted to fly in canada. regulations banning the flying of uavs near airports had been introduced earlier in 2017. minister of transport marc garneau released a statement saying " although the vast majority of drone operators fly responsibly, it was our concern for incidents like this that prompted me to take action and issue interim safety measures restricting where recreational drones could be flown. i would like to remind drone operators that endangering the safety of an aircraft is extremely dangerous and a serious offence. " 10 august 2018 in the first - ever recorded mid - air collision between a uav and a hot air balloon, the balloon, carrying a certified pilot and two passengers, was struck by a dji mavic pro while flying near the teton county fairgrounds in driggs, idaho, united states. the drone was destroyed after its rotors were sheared off on contact with the balloon's envelope and load lines, and fell to earth ; the balloon suffered no significant damage and landed safely with no injuries to the pilot or passengers. the inexperienced hobbyist drone operator reportedly lost sight of the balloon in the aircraft's monitor and was operating within 5 miles ( 8 km ) of driggs β reed memorial airport without notifying air traffic control, a violation of federal aviation regulations ; the balloon pilot had relied on radio communication with nearby manned aircraft and air traffic control to avoid other air traffic. the balloon pilot chose to report the incident to the national transportation safety board in lieu of notifying the local sheriff's department, stating that she
of scavenged material. amoeboid cells do not have a mouth or cytostome, and there is no fixed place on the cell at which phagocytosis normally occurs. some amoebae also feed by pinocytosis, imbibing dissolved nutrients through vesicles formed within the cell membrane. = = = size range = = = the size of amoeboid cells and species is extremely variable. the marine amoeboid massisteria voersi is just 2. 3 to 3 micrometres in diameter, within the size range of many bacteria. at the other extreme, the shells of deep - sea xenophyophores can attain 20 cm in diameter. most of the free - living freshwater amoebae commonly found in pond water, ditches, and lakes are microscopic, but some species, such as the so - called " giant amoebae " pelomyxa palustris and chaos carolinense, can be large enough to see with the naked eye. = = = sexual reproduction = = = recent evidence indicates that several amoebozoa lineages undergo meiosis. orthologs of genes employed in meiosis of sexual eukaryotes have recently been identified in the acanthamoeba genome. these genes included spo11, mre11, rad50, rad51, rad52, mnd1, dmc1, msh and mlh. this finding suggests that the β'acanthamoeba'β are capable of some form of meiosis and may be able to undergo sexual reproduction. the meiosis - specific recombinase, dmc1, is required for efficient meiotic homologous recombination, and dmc1 is expressed in entamoeba histolytica. the purified dmc1 from e. histolytica forms presynaptic filaments and catalyses atp - dependent homologous dna pairing and dna strand exchange over at least several thousand base pairs. the dna pairing and strand exchange reactions are enhanced by the eukaryotic meiosis - specific recombination accessory factor ( heterodimer ) hop2 - mnd1. these processes are central to meiotic recombination, suggesting that e. histolytica undergoes meiosis. studies of entamoeba invadens found that, during the conversion from the tetraploid uninucleate tropho
Answer:
|
in the troposphere
| null |
A fixed wing aircraft can fly
0. high in space
1. in the troposphere
2. inside an amoeba
3. deep underwater
air by emulating the flight mechanisms of insects and birds. these microrobots have to overcome the issues related to lift, thrust, and movement that are challenging to accomplish at such a small scale where most aerodynamic theories must be modified. active flight is the most energy - intensive mode of locomotion, as the microrobot must lift its body weight while propelling itself forward. to achieve this function, these microrobots mimic the movement of insect wings and generate the necessary airflow for producing lift and thrust. miniaturized wings of the robots are actuated with piezoelectric materials, which offer better control of wing kinematics and flight dynamics. to calculate the necessary aerodynamic power for maintaining a hover with flapping wings, the primary physical equation is expressed as m g = 2 β Ο β l 2 β β Ο
i 2 { \ displaystyle mg = 2 * \ rho * l ^ { 2 } * \ phi * \ upsilon _ { i } ^ { 2 } } where m is the body mass, l is the wing length, Ο represents the wing flapping amplitude in radians, Ο indicates the air density, and vi corresponds to the induced air speed surrounding the body, a consequence of the wings'flapping and rotation movements. this equation illustrates that a small insect or robotic device must impart sufficient momentum to the surrounding air to counterbalance its own weight. one example of a flying microrobot that utilizes flying locomotion is the robobee and delfly nimble, which, regarding flight dynamics, emulate bees and fruit flies, respectively. harvard university invented the robobee, a miniature robot that mimics a bee fly, takes off and lands like one, and moves around confined spaces. it can be used in self - driving pollination and search operations for missing people and things. the delfly nimble, developed by the delft university of technology, is one of the most agile micro aerial vehicles that can mimic the maneuverability of a fruit fly by doing different tricks due to its minimal weight and advanced control mechanisms. = = types and applications = = due to their small size, microbots are potentially very cheap, and could be used in large numbers ( swarm robotics ) to explore environments which are too small or too dangerous for people or larger robots. it is expected that microbots will be useful in applications such as looking for survivors in collapsed buildings after an earthquake or crawling through the digestive tract. what microbots lack in brawn or computational power
when the vehicle reaches the top and bottom depth limits of its operating envelope. without a buoyancy engine, an underwater glider could be used once and then deploy a package that would float to the surface where it can be retrieved, or drop ballast, with the same effect. with the addition of a buoyancy engine, the underwater glider becomes a more viable tool as it can stay in operation longer and can be reused. an underwater glider, like an aircraft glider, loses altitude as it moves forward. in the case of an underwater glider, its depth increases. eventually, any glider will touch the ground. with a gliding aircraft, this is not much of an issue since they are expected to land and are reusable when they do so. this is not true for an underwater glider. if an underwater glider were to land on the ocean floor, it is essentially lost. since a buoyancy engine allows a glider to change its density, the glider can glide in two directions. it can glide down like an aircraft, or it can glide up if it makes itself less dense than the water around it. in this way, as long as the buoyancy engine remains active, and power is available, an underwater glider can continue to operate. the actual operation of a buoyancy engine occurs through a complex system of tubing, valves, and sensors. when a glider equipped with a buoyancy engine is deployed, the glider will increase its density to sink to an appropriate depth at which to start its mission. once at that depth, the glider will begin the mission and the buoyancy engine will adjust the density to a value that is efficient for gliding. when a predetermined depth has been reached, the buoyancy engine will decrease density and this will cause the glider to glide back towards the surface. in this way, the underwater glider remains in operation between two preset depths. the mechanism used to modify buoyancy for this purpose is often a variable buoyancy pressure vessel. = = application = = the buoyancy engine, when combined with the underwater glider, gives scientists and other individuals or organizations access to hardware to survey the ocean depths. for instance, the buoyancy engine, since it is used on underwater gliders and extends the capabilities of such craft, would be able to more effectively map the ocean floor. the use of the buoyancy engine has other effects as well. it could be used to improve the detection of underwater stores of oil. in addition, since the operational range of underwater
youtube video ) from summit to seafloor β lifted weight as a function of altitude and depth by rolf steinegger joukowski transform interactive webapp archived october 19, 2019, at the wayback machine how planes fly archived june 11, 2021, at the wayback machine youtube video presentation by krzysztof fidkowski, associate professor of aerospace engineering at the university of michigan
operator deliberately flew the uav 2. 5 miles away from himself and was unaware of the helicopters'presence. the operator did not know of the collision until contacted by the ntsb and when interviewed by them showed only a general cursory awareness of the regulations. there was also a temporary flight restriction in place, from which the black hawk ( but not the uav ) was exempt. uavs are prohibited from flying beyond the pilot's line of sight under faa regulations. 12 october 2017 a beechcraft king air a100 of skyjet aviation collided with a uav as the former was approaching jean lesage airport near quebec city, canada. the aircraft landed safely despite its wing being hit. the aircraft had flown from rouyn - noranda airport to jean lesage airport with six passengers and two crew. a spokeswoman for the quebec city police said that neither the uav nor the operator had been found. it had been flying at 1500 feet β five times the maximum altitude that uavs are permitted to fly in canada. regulations banning the flying of uavs near airports had been introduced earlier in 2017. minister of transport marc garneau released a statement saying " although the vast majority of drone operators fly responsibly, it was our concern for incidents like this that prompted me to take action and issue interim safety measures restricting where recreational drones could be flown. i would like to remind drone operators that endangering the safety of an aircraft is extremely dangerous and a serious offence. " 10 august 2018 in the first - ever recorded mid - air collision between a uav and a hot air balloon, the balloon, carrying a certified pilot and two passengers, was struck by a dji mavic pro while flying near the teton county fairgrounds in driggs, idaho, united states. the drone was destroyed after its rotors were sheared off on contact with the balloon's envelope and load lines, and fell to earth ; the balloon suffered no significant damage and landed safely with no injuries to the pilot or passengers. the inexperienced hobbyist drone operator reportedly lost sight of the balloon in the aircraft's monitor and was operating within 5 miles ( 8 km ) of driggs β reed memorial airport without notifying air traffic control, a violation of federal aviation regulations ; the balloon pilot had relied on radio communication with nearby manned aircraft and air traffic control to avoid other air traffic. the balloon pilot chose to report the incident to the national transportation safety board in lieu of notifying the local sheriff's department, stating that she
of scavenged material. amoeboid cells do not have a mouth or cytostome, and there is no fixed place on the cell at which phagocytosis normally occurs. some amoebae also feed by pinocytosis, imbibing dissolved nutrients through vesicles formed within the cell membrane. = = = size range = = = the size of amoeboid cells and species is extremely variable. the marine amoeboid massisteria voersi is just 2. 3 to 3 micrometres in diameter, within the size range of many bacteria. at the other extreme, the shells of deep - sea xenophyophores can attain 20 cm in diameter. most of the free - living freshwater amoebae commonly found in pond water, ditches, and lakes are microscopic, but some species, such as the so - called " giant amoebae " pelomyxa palustris and chaos carolinense, can be large enough to see with the naked eye. = = = sexual reproduction = = = recent evidence indicates that several amoebozoa lineages undergo meiosis. orthologs of genes employed in meiosis of sexual eukaryotes have recently been identified in the acanthamoeba genome. these genes included spo11, mre11, rad50, rad51, rad52, mnd1, dmc1, msh and mlh. this finding suggests that the β'acanthamoeba'β are capable of some form of meiosis and may be able to undergo sexual reproduction. the meiosis - specific recombinase, dmc1, is required for efficient meiotic homologous recombination, and dmc1 is expressed in entamoeba histolytica. the purified dmc1 from e. histolytica forms presynaptic filaments and catalyses atp - dependent homologous dna pairing and dna strand exchange over at least several thousand base pairs. the dna pairing and strand exchange reactions are enhanced by the eukaryotic meiosis - specific recombination accessory factor ( heterodimer ) hop2 - mnd1. these processes are central to meiotic recombination, suggesting that e. histolytica undergoes meiosis. studies of entamoeba invadens found that, during the conversion from the tetraploid uninucleate tropho
Answer:
|
inside an amoeba
| 0.3 |
When the weatherman says to expect a storm, he most-likely is telling you to watch for
0. downpour conditions
1. nothing
2. flying cats
3. Water parks
oxford university press. isbn 978 - 0 - 19 - 506268 - 7. reynolds, r ( 2005 ) [ 2005 ]. guide to weather. buffalo, new york : firefly books inc. p. 208. isbn 978 - 1 - 55407 - 110 - 4. holton, j. r. ( 2004 ) [ 2004 ]. an introduction to dynamic meteorology ( 4th ed. ). burlington, md : elsevier inc. isbn 978 - 0 - 12 - 354015 - 7. archived from the original on 19 july 2013. retrieved 21 may 2017. roulstone, ian & norbury, john ( 2013 ). invisible in the storm : the role of mathematics in understanding weather. princeton university press. isbn 978 - 0691152721. = = = dictionaries and encyclopedias = = = glickman, todd s. ( june 2000 ). meteorology glossary ( electronic ) ( 2nd ed. ). cambridge, massachusetts : american meteorological society. archived from the original on 10 march 2014. retrieved 10 march 2014. gustavo herrera, roberto ; garcia - herrera, ricardo ; prieto, luis ; gallego, david ; hernandez, emiliano ; gimeno, luis ; konnen, gunther ; koek, frits ; wheeler, dennis ; wilkinson, clive ; del rosario prieto, maria ; baez, carlos ; woodruff, scott. a dictionary of nautical meteorological terms : cliwoc multilingual dictionary of meteorological terms ; an english / spanish / french / dutch dictionary of windforce terms used by mariners from 1750 to 1850 ( pdf ). cliwoc. archived from the original ( pdf ) on 21 april 2021. retrieved 13 april 2014. " meteorology encyclopedia ". central weather bureau. 6 december 2018. archived from the original on 21 september 2014. retrieved 14 september 2014. = = = history = = = lawrence - mathers, anne ( 2020 ). medieval meteorology : forecasting the weather from aristotle to the almanac. cambridge : cambridge university press. bibcode : 2020mmfw. book..... l. doi : 10. 1017 / 9781108289948. isbn 978 - 1 - 108 - 40600 - 0. s2cid 211658964. = = external links = = please see weather forecasting for weather forecast sites. air quality meteorology archived 25 july 2009 at the wayback machine β online course that introduces the basic concepts
is called forked lightning. when it swoops down upon some object it is called'swooping lightning'after aristotle, progress in meteorology stalled for a long time. theophrastus compiled a book on weather forecasting, called the book of signs, as well as on winds. he gave hundreds of signs for weather phenomena for a period up to a year. his system was based on dividing the year by the setting and the rising of the pleiad, halves into solstices and equinoxes, and the continuity of the weather for those periods. he also divided months into the new moon, fourth day, eighth day and full moon, in likelihood of a change in the weather occurring. the day was divided into sunrise, mid - morning, noon, mid - afternoon and sunset, with corresponding divisions of the night, with change being likely at one of these divisions. applying the divisions and a principle of balance in the yearly weather, he came up with forecasts like that if a lot of rain falls in the winter, the spring is usually dry. rules based on actions of animals are also present in his work, like that if a dog rolls on the ground, it is a sign of a storm. shooting stars and the moon were also considered significant. however, he made no attempt to explain these phenomena, referring only to the aristotelian method. the work of theophrastus remained a dominant influence in weather forecasting for nearly 2, 000 years. = = = meteorology after aristotle = = = meteorology continued to be studied and developed over the centuries, but it was not until the renaissance in the 14th to 17th centuries that significant advancements were made in the field. scientists such as galileo and descartes introduced new methods and ideas, leading to the scientific revolution in meteorology. speculation on the cause of the flooding of the nile ended when eratosthenes, according to proclus, stated that it was known that man had gone to the sources of the nile and observed the rains, although interest in its implications continued. during the era of roman greece and europe, scientific interest in meteorology waned. in the 1st century bc, most natural philosophers claimed that the clouds and winds extended up to 111 miles, but posidonius thought that they reached up to five miles, after which the air is clear, liquid and luminous. he closely followed aristotle's theories. by the end of the second century bc, the center of science shifted from athens to alexandria, home to
) pyrocumulus = = q = = quantitative precipitation estimation quantitative precipitation forecast quasi - geostrophic equations = = r = = radiance radiant barrier radiant energy radiation radiation budget radiation hormesis radiation poisoning ( radiation sickness ) radiative cooling radiative forcing radiological weapon ( radiological dispersion device [ rdd ] ) radiosonde radius of outermost closed isobar rain rain fade ( fading of signal by rain or snow ) rain gauge rain sensor rain shadow rainbow rainforest rarefaction realclimate ( commentary site on climate science ) realsky ( digital photographic sky atlas ) relative humidity relative pressure ( relief precipitation : see ) orographic lift research balloon resistance thermometer ( resistance temperature detector ) ( rtd ) rime ( frost ) = = s = = saffir - simpson hurricane scale satellite temperature measurements ( sea islands hurricane ) 1893 sea islands hurricane sea level ( sea level pressure ) atmospheric pressure sea surface temperature ( sst ) severe weather severe weather terminology ( united states ) skew - t log - p diagram sky skyglow smoke snow solar and heliospheric observatory solar azimuth angle solar cell solar collector solar constant solar cycle solar eclipse solar flare ( see under hazards ) solar furnace solar greenhouse ( technical ) solar heating solar maximum solar maximum mission solar minimum solar mirror solar proton event solar radiation ( solar irradiance ) ( solar storm ) geomagnetic storm solar thermal collector solar thermal energy solar updraft tower solar variation solar wind solarium space geostrategy ( astrostrategy ) ( geostrategy in space ) space science and engineering center ( ssec ) space weather ( specific humidity : see ) humidity ( see under specific humidity ) squall squall line ( standard atmospheric pressure ) atmospheric pressure ( standard atmosphere ) standard conditions for temperature and pressure storm storm cellar storm chasing storm drain ( storm sewer ) ( stormwater drain ) storm - scale storm surge storm tide storm track storm warning ( see same for " storm watch " ) storm scale stormwater stratopause stratosphere stuve diagram subarctic subarctic climate subtropical cyclone ( see same for " subtropical depression " and for " subtropical storm " ) subtropics ( see same for " subtropical " and for " subtropical climate " ) sudden ionospheric disturbance ( sid ) sudden stratospheric warming sun sun dog ( sundog ) ( parhelion ) sunlight sunshower sunspot ( see under " significant events " ) supercell surface temperature inversion surface
when this is not the case b ^ 0 : 5 { \ displaystyle \ mathbf { { \ hat { b } } _ { 0 : 5 } } } needs to be combined with the initial state vector to find the most likely initial state. we thus find that the forward probabilities by themselves are sufficient to calculate the most likely final state. similarly, the backward probabilities can be combined with the initial state vector to provide the most probable initial state given the observations. the forward and backward probabilities need only be combined to infer the most probable states between the initial and final points. the calculations above reveal that the most probable weather state on every day except for the third one was " rain ". they tell us more than this, however, as they now provide a way to quantify the probabilities of each state at different times. perhaps most importantly, our value at Ξ³ 5 { \ displaystyle \ mathbf { \ gamma _ { 5 } } } quantifies our knowledge of the state vector at the end of the observation sequence. we can then use this to predict the probability of the various weather states tomorrow as well as the probability of observing an umbrella. = = performance = = the forward β backward algorithm runs with time complexity o ( s 2 t ) { \ displaystyle o ( s ^ { 2 } t ) } in space o ( s t ) { \ displaystyle o ( st ) }, where t { \ displaystyle t } is the length of the time sequence and s { \ displaystyle s } is the number of symbols in the state alphabet. the algorithm can also run in constant space with time complexity o ( s 2 t 2 ) { \ displaystyle o ( s ^ { 2 } t ^ { 2 } ) } by recomputing values at each step. for comparison, a brute - force procedure would generate all possible s t { \ displaystyle s ^ { t } } state sequences and calculate the joint probability of each state sequence with the observed series of events, which would have time complexity o ( t β
s t ) { \ displaystyle o ( t \ cdot s ^ { t } ) }. brute force is intractable for realistic problems, as the number of possible hidden node sequences typically is extremely high. an enhancement to the general forward - backward algorithm, called the island algorithm, trades smaller memory usage for longer running time, taking o ( s 2 t log t ) { \ displaystyle o ( s ^ { 2 } t \ log
may ensue, as a parcel rises to the level of free convection ( lfc ), after which it enters the free convective layer ( fcl ) and usually rises to the equilibrium level ( el ). if the environmental lapse rate is larger than the dry adiabatic lapse rate, it has a superadiabatic lapse rate, the air is absolutely unstable β a parcel of air will gain buoyancy as it rises both below and above the lifting condensation level or convective condensation level. this often happens in the afternoon mainly over land masses. in these conditions, the likelihood of cumulus clouds, showers or even thunderstorms is increased. meteorologists use radiosondes to measure the environmental lapse rate and compare it to the predicted adiabatic lapse rate to forecast the likelihood that air will rise. charts of the environmental lapse rate are known as thermodynamic diagrams, examples of which include skew - t log - p diagrams and tephigrams. ( see also thermals ). the difference in moist adiabatic lapse rate and the dry rate is the cause of foehn wind phenomenon ( also known as " chinook winds " in parts of north america ). the phenomenon exists because warm moist air rises through orographic lifting up and over the top of a mountain range or large mountain. the temperature decreases with the dry adiabatic lapse rate, until it hits the dew point, where water vapor in the air begins to condense. above that altitude, the adiabatic lapse rate decreases to the moist adiabatic lapse rate as the air continues to rise. condensation is also commonly followed by precipitation on the top and windward sides of the mountain. as the air descends on the leeward side, it is warmed by adiabatic compression at the dry adiabatic lapse rate. thus, the foehn wind at a certain altitude is warmer than the corresponding altitude on the windward side of the mountain range. in addition, because the air has lost much of its original water vapor content, the descending air creates an arid region on the leeward side of the mountain. = = impact on the greenhouse effect = = if the environmental lapse rate was zero, so that the atmosphere was the same temperature at all elevations, then there would be no greenhouse effect. this doesn't mean the lapse rate and the greenhouse effect are the same thing, just that the lapse rate is a prere
Answer:
|
downpour conditions
| null |
When the weatherman says to expect a storm, he most-likely is telling you to watch for
0. downpour conditions
1. nothing
2. flying cats
3. Water parks
oxford university press. isbn 978 - 0 - 19 - 506268 - 7. reynolds, r ( 2005 ) [ 2005 ]. guide to weather. buffalo, new york : firefly books inc. p. 208. isbn 978 - 1 - 55407 - 110 - 4. holton, j. r. ( 2004 ) [ 2004 ]. an introduction to dynamic meteorology ( 4th ed. ). burlington, md : elsevier inc. isbn 978 - 0 - 12 - 354015 - 7. archived from the original on 19 july 2013. retrieved 21 may 2017. roulstone, ian & norbury, john ( 2013 ). invisible in the storm : the role of mathematics in understanding weather. princeton university press. isbn 978 - 0691152721. = = = dictionaries and encyclopedias = = = glickman, todd s. ( june 2000 ). meteorology glossary ( electronic ) ( 2nd ed. ). cambridge, massachusetts : american meteorological society. archived from the original on 10 march 2014. retrieved 10 march 2014. gustavo herrera, roberto ; garcia - herrera, ricardo ; prieto, luis ; gallego, david ; hernandez, emiliano ; gimeno, luis ; konnen, gunther ; koek, frits ; wheeler, dennis ; wilkinson, clive ; del rosario prieto, maria ; baez, carlos ; woodruff, scott. a dictionary of nautical meteorological terms : cliwoc multilingual dictionary of meteorological terms ; an english / spanish / french / dutch dictionary of windforce terms used by mariners from 1750 to 1850 ( pdf ). cliwoc. archived from the original ( pdf ) on 21 april 2021. retrieved 13 april 2014. " meteorology encyclopedia ". central weather bureau. 6 december 2018. archived from the original on 21 september 2014. retrieved 14 september 2014. = = = history = = = lawrence - mathers, anne ( 2020 ). medieval meteorology : forecasting the weather from aristotle to the almanac. cambridge : cambridge university press. bibcode : 2020mmfw. book..... l. doi : 10. 1017 / 9781108289948. isbn 978 - 1 - 108 - 40600 - 0. s2cid 211658964. = = external links = = please see weather forecasting for weather forecast sites. air quality meteorology archived 25 july 2009 at the wayback machine β online course that introduces the basic concepts
is called forked lightning. when it swoops down upon some object it is called'swooping lightning'after aristotle, progress in meteorology stalled for a long time. theophrastus compiled a book on weather forecasting, called the book of signs, as well as on winds. he gave hundreds of signs for weather phenomena for a period up to a year. his system was based on dividing the year by the setting and the rising of the pleiad, halves into solstices and equinoxes, and the continuity of the weather for those periods. he also divided months into the new moon, fourth day, eighth day and full moon, in likelihood of a change in the weather occurring. the day was divided into sunrise, mid - morning, noon, mid - afternoon and sunset, with corresponding divisions of the night, with change being likely at one of these divisions. applying the divisions and a principle of balance in the yearly weather, he came up with forecasts like that if a lot of rain falls in the winter, the spring is usually dry. rules based on actions of animals are also present in his work, like that if a dog rolls on the ground, it is a sign of a storm. shooting stars and the moon were also considered significant. however, he made no attempt to explain these phenomena, referring only to the aristotelian method. the work of theophrastus remained a dominant influence in weather forecasting for nearly 2, 000 years. = = = meteorology after aristotle = = = meteorology continued to be studied and developed over the centuries, but it was not until the renaissance in the 14th to 17th centuries that significant advancements were made in the field. scientists such as galileo and descartes introduced new methods and ideas, leading to the scientific revolution in meteorology. speculation on the cause of the flooding of the nile ended when eratosthenes, according to proclus, stated that it was known that man had gone to the sources of the nile and observed the rains, although interest in its implications continued. during the era of roman greece and europe, scientific interest in meteorology waned. in the 1st century bc, most natural philosophers claimed that the clouds and winds extended up to 111 miles, but posidonius thought that they reached up to five miles, after which the air is clear, liquid and luminous. he closely followed aristotle's theories. by the end of the second century bc, the center of science shifted from athens to alexandria, home to
) pyrocumulus = = q = = quantitative precipitation estimation quantitative precipitation forecast quasi - geostrophic equations = = r = = radiance radiant barrier radiant energy radiation radiation budget radiation hormesis radiation poisoning ( radiation sickness ) radiative cooling radiative forcing radiological weapon ( radiological dispersion device [ rdd ] ) radiosonde radius of outermost closed isobar rain rain fade ( fading of signal by rain or snow ) rain gauge rain sensor rain shadow rainbow rainforest rarefaction realclimate ( commentary site on climate science ) realsky ( digital photographic sky atlas ) relative humidity relative pressure ( relief precipitation : see ) orographic lift research balloon resistance thermometer ( resistance temperature detector ) ( rtd ) rime ( frost ) = = s = = saffir - simpson hurricane scale satellite temperature measurements ( sea islands hurricane ) 1893 sea islands hurricane sea level ( sea level pressure ) atmospheric pressure sea surface temperature ( sst ) severe weather severe weather terminology ( united states ) skew - t log - p diagram sky skyglow smoke snow solar and heliospheric observatory solar azimuth angle solar cell solar collector solar constant solar cycle solar eclipse solar flare ( see under hazards ) solar furnace solar greenhouse ( technical ) solar heating solar maximum solar maximum mission solar minimum solar mirror solar proton event solar radiation ( solar irradiance ) ( solar storm ) geomagnetic storm solar thermal collector solar thermal energy solar updraft tower solar variation solar wind solarium space geostrategy ( astrostrategy ) ( geostrategy in space ) space science and engineering center ( ssec ) space weather ( specific humidity : see ) humidity ( see under specific humidity ) squall squall line ( standard atmospheric pressure ) atmospheric pressure ( standard atmosphere ) standard conditions for temperature and pressure storm storm cellar storm chasing storm drain ( storm sewer ) ( stormwater drain ) storm - scale storm surge storm tide storm track storm warning ( see same for " storm watch " ) storm scale stormwater stratopause stratosphere stuve diagram subarctic subarctic climate subtropical cyclone ( see same for " subtropical depression " and for " subtropical storm " ) subtropics ( see same for " subtropical " and for " subtropical climate " ) sudden ionospheric disturbance ( sid ) sudden stratospheric warming sun sun dog ( sundog ) ( parhelion ) sunlight sunshower sunspot ( see under " significant events " ) supercell surface temperature inversion surface
when this is not the case b ^ 0 : 5 { \ displaystyle \ mathbf { { \ hat { b } } _ { 0 : 5 } } } needs to be combined with the initial state vector to find the most likely initial state. we thus find that the forward probabilities by themselves are sufficient to calculate the most likely final state. similarly, the backward probabilities can be combined with the initial state vector to provide the most probable initial state given the observations. the forward and backward probabilities need only be combined to infer the most probable states between the initial and final points. the calculations above reveal that the most probable weather state on every day except for the third one was " rain ". they tell us more than this, however, as they now provide a way to quantify the probabilities of each state at different times. perhaps most importantly, our value at Ξ³ 5 { \ displaystyle \ mathbf { \ gamma _ { 5 } } } quantifies our knowledge of the state vector at the end of the observation sequence. we can then use this to predict the probability of the various weather states tomorrow as well as the probability of observing an umbrella. = = performance = = the forward β backward algorithm runs with time complexity o ( s 2 t ) { \ displaystyle o ( s ^ { 2 } t ) } in space o ( s t ) { \ displaystyle o ( st ) }, where t { \ displaystyle t } is the length of the time sequence and s { \ displaystyle s } is the number of symbols in the state alphabet. the algorithm can also run in constant space with time complexity o ( s 2 t 2 ) { \ displaystyle o ( s ^ { 2 } t ^ { 2 } ) } by recomputing values at each step. for comparison, a brute - force procedure would generate all possible s t { \ displaystyle s ^ { t } } state sequences and calculate the joint probability of each state sequence with the observed series of events, which would have time complexity o ( t β
s t ) { \ displaystyle o ( t \ cdot s ^ { t } ) }. brute force is intractable for realistic problems, as the number of possible hidden node sequences typically is extremely high. an enhancement to the general forward - backward algorithm, called the island algorithm, trades smaller memory usage for longer running time, taking o ( s 2 t log t ) { \ displaystyle o ( s ^ { 2 } t \ log
may ensue, as a parcel rises to the level of free convection ( lfc ), after which it enters the free convective layer ( fcl ) and usually rises to the equilibrium level ( el ). if the environmental lapse rate is larger than the dry adiabatic lapse rate, it has a superadiabatic lapse rate, the air is absolutely unstable β a parcel of air will gain buoyancy as it rises both below and above the lifting condensation level or convective condensation level. this often happens in the afternoon mainly over land masses. in these conditions, the likelihood of cumulus clouds, showers or even thunderstorms is increased. meteorologists use radiosondes to measure the environmental lapse rate and compare it to the predicted adiabatic lapse rate to forecast the likelihood that air will rise. charts of the environmental lapse rate are known as thermodynamic diagrams, examples of which include skew - t log - p diagrams and tephigrams. ( see also thermals ). the difference in moist adiabatic lapse rate and the dry rate is the cause of foehn wind phenomenon ( also known as " chinook winds " in parts of north america ). the phenomenon exists because warm moist air rises through orographic lifting up and over the top of a mountain range or large mountain. the temperature decreases with the dry adiabatic lapse rate, until it hits the dew point, where water vapor in the air begins to condense. above that altitude, the adiabatic lapse rate decreases to the moist adiabatic lapse rate as the air continues to rise. condensation is also commonly followed by precipitation on the top and windward sides of the mountain. as the air descends on the leeward side, it is warmed by adiabatic compression at the dry adiabatic lapse rate. thus, the foehn wind at a certain altitude is warmer than the corresponding altitude on the windward side of the mountain range. in addition, because the air has lost much of its original water vapor content, the descending air creates an arid region on the leeward side of the mountain. = = impact on the greenhouse effect = = if the environmental lapse rate was zero, so that the atmosphere was the same temperature at all elevations, then there would be no greenhouse effect. this doesn't mean the lapse rate and the greenhouse effect are the same thing, just that the lapse rate is a prere
Answer:
|
flying cats
| 0.3 |
Wildfire is when what catches fire?
0. timberland
1. farms
2. cities
3. winds
##itate against catastrophic wildfires. forest fires gained a negative connotation because of cultural references to uncontrolled fires that take lives and destroy homes and properties. controlled burns can decrease the risk of wildfires through the regular burning of undergrowth that would otherwise fuel rampant burning. broadcast burning has helped to fireproof landscapes by burning off undergrowth and using up potential fuel, leaving little or no chance for a wildfire to be sparked by lightning. of all of the mechanisms of human - mediated disturbances, anthropogenic fire has become one of great interest to ecologists, geographers, soil scientists, and anthropologists alike. by studying the effects of anthropogenic fires, anthropologists have been able to identify landscape uses and requirements of past cultures. ecologists became interested in the study of anthropogenic fire as to utilize methods from previous cultures to develop policies for regular burning. geographers and soil scientists are interested in the utility of anthropic soils caused by burning in the past. the interest in anthropogenic fire came about in the wake of the industrial revolution. this time period included a mass migration from rural to urban areas, which decreased controlled burning in the countryside. this led to an increase in the frequency and strength of wildfires, thus initiating a need to develop proper prevention methods. historical ecology focuses on the impact on landscapes through human - mediated disturbances, once such being anthropogenic fire. it is a fusion of ecological, geographical, anthropological, and pedological interests. = = = biological invasions = = = biological invasions are composed of exotic biota that enter a landscape and replace species with which they share similarities in structure and ecological function. because they multiply and grow quickly, invasive species can eliminate or greatly reduce existing flora and fauna by various mechanisms, such as direct competitive exclusion. invasive species typically spread at a faster rate when they have no natural predators or when they fill an empty niche. these invasions often occur in a historical context and are classified as a type of human - mediated disturbance called human - mediated invasions. invasive species can be transported intentionally or accidentally. many invasive species originate in shipping areas from where they are unintentionally transported to their new location. sometimes human populations intentionally introduce species into new landscapes to serve various purposes, ranging from decoration to erosion control. these species can later become invasive and dramatically modify the landscape. it is important to note that not all exotic species are invasive ; in fact, the majority of newly introduced species never become invasive. humans have on their
fire history, the ecological science of studying the history of wildfires, is a subdiscipline of fire ecology. patterns of forest fires in historical and prehistorical times provide information relevant to the vegetation pattern in modern landscapes. it gives an estimate of a natural disturbance regime's historical range of variability and can be used to identify the processes affecting fire occurrence. fire history reconstructions are achieved by compiling atlases of past fires, using the tree ring record from fire scars and tree ages and the charcoal record from soils and sediments. = = prehistoric fires = = sustained wildfire can only exist once oxygen levels and fuel sources are present in sufficient quantities. between 400 and 450 million years ago, fire became a landscape feature. : 11 β 14 the presence of fusain ( fossil charcoal ), beginning in the early carboniferous attests to this fire history and forms an important element of the cretaceous β paleogene boundary. : 11 β 14 = = mapped data = = = = tree - ring data = = the growth record of a tree in seasonal climates is preserved in the growth rings in the stem wood ; the field of dendrochronology is the study of the record of climate and other events preserved in the growth record. each growth ring represents one year of life. the thickness of each ring indicates the amount of wood produced during that growing season. large cells can quickly divide rapidly at the beginning of the growing season, creating a light - colored wood. when growth slows down, generally in colder months, a darker wood is created from smaller cells, dividing more slowly. thus, one year is represented by a light inner ring and a darker outer ring. rings can be counted from dead trees and stumps left behind from logging. a sample can be collected from a living tree using tools like the increment borer. the increment borer is a hollow steel tube that extracts a core sample from a tree β s trunk. the growth rings in a core sample are counted to determine the age of that tree. the ages of stand - replacing fires may be determined by determining the cohort age of trees established after a fire. for example, tree - ring dating of large stands will show the age of the forest and may provide an estimate of when the last significant disturbance event occurred. sometimes, growth rings exhibit scars. a fire scar forms when heat kills the vascular cambium beneath the bark, which then heals over subsequent years as growth rings curl over the scarred area, thus protecting the tree from infection.
engaged community in which the awareness and actions of residents regarding infrastructure, buildings, landscaping, and the surrounding ecosystem lessens the need for extensive protection actions and enables the community to safely accept fire as a part of the surrounding landscape. " three groups are responsible for achieving the three wui objectives, these are land management agencies, local governments, and individuals. land management agencies eliminate ignition sources by hardening infrastructure, reduce wildfire size and intensity through fuel and vegetation management, reduce vulnerability through community education on individual preparedness, and respond to wildfires with suppression. local governments control human factors through avoiding moderate density development zoning. individuals reduce vulnerability through preparedness in increasing home resistance to ignition, reducing flammability of structures, and eliminating ember generating materials. fire - adapted communities have been successful in interacting with wildfires. the key benefit of fire - adapted communities is that a reliance on individuals as a core block in the responsibility framework reduces wui expenditures by local, regional, and national governments. = = = = reducing risk through zone defenses = = = = the risk of a structure to ignite in a wildfire is calculated by a home ignition zone ( hiz ) metric. the hiz includes at a minimum the space within a 200 foot ( 61 m ) radius around a structure. the hiz is a guideline for whoever is responsible for structure wildfire protection ; landlords and tenants ( homeowner if they are the same ) are responsible for physically constructing and maintaining defense zones while local government defines land use boundaries in a way that defense zones are effective ( note : fire - resistant is arbitrary and is not defined in hours of resistance for a given degree of heat ; these guidelines are relaxed for non - evergreen trees which are less flammable ; this guide is not intended to prevent combustion of individual structures in a wildfire β it is intended to prevent catastrophic wildfire in the wui ) : guidelines for structures : roof materials are fire - resistant and do not produce embers. exterior wall materials are fire - resistant. vents for eaves, attics, foundations, and roof are covered with wire mesh fine enough to catch embers deck and porch materials are fire - resistant. guidelines for landscaping : keep vegetation from around windows ( heat will break glass ). keep plants farther than 5 feet ( 1. 5 m ) from walls ; this is a bare dirt no - grow zone, optional to use mowed green lawn grass and non - combustible mulch with sparse deciduous plants. keep trees from growing within 30 feet ( 9.
spawning which can result in a decrease in numbers of fish. fishing is also a cultural practice that many indigenous communities still practise today and with tpk, these communities know there can be variance in time and change of numbers of fish from one year to the next. = = indigenous and western application of traditional phenological knowledge = = tpk can be used as a predictive and management tool in both traditional indigenous practices and western practices. embracing tk and continuous observations of the physical environment creates reliable information for future generations. it pertains to the interconnectivity of animal species, plant species and human behaviour. = = = indigenous applications = = = fire management can be timed with phenological events in north - american indigenous nations. burning shrubs in vast areas would help deer find food in the next season. burning causes more water to be retained in the soil which promotes seedling sprouts in the spring and summer. for indigenous communities in california, there can be more grass growth which is used for cultural " deer grass " weaving. spring burning also promote species diversity and different cultivation such as tobacco. fire can kill fast growing vegetation and pests, and aid full - light vegetation to grow in these areas i. e. oak and huckleberries. hence, traditional knowledge and tpk can help with food security, food for wildlife. = = = western applications = = = tpk and tek are seen as sustainable practices to help fight against climate change and are starting to be recognised as a tool to help mitigate food insecurity and issues regarding biodiversity loss. a term to describe the combination of indigenous knowledge and western knowledge is known as two - eyed seeing. for instance, tpk is a tool for fire management that western communities have adopted to decrease the severity of fires. = = tpk and language = = the transmission of tpk is passed down through stories which can be in the form of indirect tpk. it is not actually observed by the eye of the learner but rather transmitted through language by family members and community members. = = sustainability and biodiversity = = conservation of the land is engrained in indigenous knowledge. practises of indigenous knowledge can be useful for sustainability and solutions for modern day environmental issues regarding climate change and biodiversity loss. tpk, tek, tk, ik are ways to look at landscape ecology in a method that also scientists and the general public can learn from. many practises can aid sustainable practises and fights
1156 floods have short and long - term negative implications to people's health and well - being. short term implications include mortalities, injuries and diseases, while long term implications include non - communicable diseases and psychosocial health aspects. for example, the 2022 pakistan floods ( which were likely more severe because of climate change ) affected people's health directly and indirectly. there were outbreaks of diseases like malaria, dengue, and other skin diseases. = = = wildfires = = = climate change increases wildfire potential and activity. climate change leads to a warmer ground temperature and its effects include earlier snowmelt dates, drier than expected vegetation, increased number of potential fire days, increased occurrence of summer droughts, and a prolonged dry season. wood smoke from wildfires produces particulate matter that has damaging effects to human health. the health effects of wildfire smoke exposure include exacerbation and development of respiratory illness such as asthma and chronic obstructive pulmonary disorder ; increased risk of lung cancer, mesothelioma and tuberculosis ; increased airway hyper - responsiveness ; changes in levels of inflammatory mediators and coagulation factors ; and respiratory tract infection. = = = storms = = = storms become wetter under climate change. these include tropical cyclones and extratropical cyclones. both the maximum and mean rainfall rates increase. this more extreme rainfall is also true for thunderstorms in some regions. furthermore, tropical cyclones and storm tracks are moving towards the poles. this means some regions will see large changes in maximum wind speeds. scientists expect there will be fewer tropical cyclones. but they expect their strength to increase. = = health risks from climate - sensitive infectious diseases = = = = health risks from changes in air quality = = = = = indoor air quality = = = indoor air pollution is known to affect the health, comfort, and well - being of building occupants. it has also been linked to sick building syndrome, respiratory issues, reduced productivity, and impaired learning in schools. indoor air quality is linked inextricably to outdoor air quality. climate change can affect indoor air quality by increasing the level of outdoor air pollutants such as ozone and particulate matter, for example through emissions from wildfires caused by extreme heat and drought. there are numerous predictions for how indoor air pollutants will change in future. models have attempted to predict how the forecasted scenarios will affect indoor air quality and indoor comfort parameters such as humidity and temperature. the net - zero challenge requires significant changes in
Answer:
|
timberland
| null |
Wildfire is when what catches fire?
0. timberland
1. farms
2. cities
3. winds
##itate against catastrophic wildfires. forest fires gained a negative connotation because of cultural references to uncontrolled fires that take lives and destroy homes and properties. controlled burns can decrease the risk of wildfires through the regular burning of undergrowth that would otherwise fuel rampant burning. broadcast burning has helped to fireproof landscapes by burning off undergrowth and using up potential fuel, leaving little or no chance for a wildfire to be sparked by lightning. of all of the mechanisms of human - mediated disturbances, anthropogenic fire has become one of great interest to ecologists, geographers, soil scientists, and anthropologists alike. by studying the effects of anthropogenic fires, anthropologists have been able to identify landscape uses and requirements of past cultures. ecologists became interested in the study of anthropogenic fire as to utilize methods from previous cultures to develop policies for regular burning. geographers and soil scientists are interested in the utility of anthropic soils caused by burning in the past. the interest in anthropogenic fire came about in the wake of the industrial revolution. this time period included a mass migration from rural to urban areas, which decreased controlled burning in the countryside. this led to an increase in the frequency and strength of wildfires, thus initiating a need to develop proper prevention methods. historical ecology focuses on the impact on landscapes through human - mediated disturbances, once such being anthropogenic fire. it is a fusion of ecological, geographical, anthropological, and pedological interests. = = = biological invasions = = = biological invasions are composed of exotic biota that enter a landscape and replace species with which they share similarities in structure and ecological function. because they multiply and grow quickly, invasive species can eliminate or greatly reduce existing flora and fauna by various mechanisms, such as direct competitive exclusion. invasive species typically spread at a faster rate when they have no natural predators or when they fill an empty niche. these invasions often occur in a historical context and are classified as a type of human - mediated disturbance called human - mediated invasions. invasive species can be transported intentionally or accidentally. many invasive species originate in shipping areas from where they are unintentionally transported to their new location. sometimes human populations intentionally introduce species into new landscapes to serve various purposes, ranging from decoration to erosion control. these species can later become invasive and dramatically modify the landscape. it is important to note that not all exotic species are invasive ; in fact, the majority of newly introduced species never become invasive. humans have on their
fire history, the ecological science of studying the history of wildfires, is a subdiscipline of fire ecology. patterns of forest fires in historical and prehistorical times provide information relevant to the vegetation pattern in modern landscapes. it gives an estimate of a natural disturbance regime's historical range of variability and can be used to identify the processes affecting fire occurrence. fire history reconstructions are achieved by compiling atlases of past fires, using the tree ring record from fire scars and tree ages and the charcoal record from soils and sediments. = = prehistoric fires = = sustained wildfire can only exist once oxygen levels and fuel sources are present in sufficient quantities. between 400 and 450 million years ago, fire became a landscape feature. : 11 β 14 the presence of fusain ( fossil charcoal ), beginning in the early carboniferous attests to this fire history and forms an important element of the cretaceous β paleogene boundary. : 11 β 14 = = mapped data = = = = tree - ring data = = the growth record of a tree in seasonal climates is preserved in the growth rings in the stem wood ; the field of dendrochronology is the study of the record of climate and other events preserved in the growth record. each growth ring represents one year of life. the thickness of each ring indicates the amount of wood produced during that growing season. large cells can quickly divide rapidly at the beginning of the growing season, creating a light - colored wood. when growth slows down, generally in colder months, a darker wood is created from smaller cells, dividing more slowly. thus, one year is represented by a light inner ring and a darker outer ring. rings can be counted from dead trees and stumps left behind from logging. a sample can be collected from a living tree using tools like the increment borer. the increment borer is a hollow steel tube that extracts a core sample from a tree β s trunk. the growth rings in a core sample are counted to determine the age of that tree. the ages of stand - replacing fires may be determined by determining the cohort age of trees established after a fire. for example, tree - ring dating of large stands will show the age of the forest and may provide an estimate of when the last significant disturbance event occurred. sometimes, growth rings exhibit scars. a fire scar forms when heat kills the vascular cambium beneath the bark, which then heals over subsequent years as growth rings curl over the scarred area, thus protecting the tree from infection.
engaged community in which the awareness and actions of residents regarding infrastructure, buildings, landscaping, and the surrounding ecosystem lessens the need for extensive protection actions and enables the community to safely accept fire as a part of the surrounding landscape. " three groups are responsible for achieving the three wui objectives, these are land management agencies, local governments, and individuals. land management agencies eliminate ignition sources by hardening infrastructure, reduce wildfire size and intensity through fuel and vegetation management, reduce vulnerability through community education on individual preparedness, and respond to wildfires with suppression. local governments control human factors through avoiding moderate density development zoning. individuals reduce vulnerability through preparedness in increasing home resistance to ignition, reducing flammability of structures, and eliminating ember generating materials. fire - adapted communities have been successful in interacting with wildfires. the key benefit of fire - adapted communities is that a reliance on individuals as a core block in the responsibility framework reduces wui expenditures by local, regional, and national governments. = = = = reducing risk through zone defenses = = = = the risk of a structure to ignite in a wildfire is calculated by a home ignition zone ( hiz ) metric. the hiz includes at a minimum the space within a 200 foot ( 61 m ) radius around a structure. the hiz is a guideline for whoever is responsible for structure wildfire protection ; landlords and tenants ( homeowner if they are the same ) are responsible for physically constructing and maintaining defense zones while local government defines land use boundaries in a way that defense zones are effective ( note : fire - resistant is arbitrary and is not defined in hours of resistance for a given degree of heat ; these guidelines are relaxed for non - evergreen trees which are less flammable ; this guide is not intended to prevent combustion of individual structures in a wildfire β it is intended to prevent catastrophic wildfire in the wui ) : guidelines for structures : roof materials are fire - resistant and do not produce embers. exterior wall materials are fire - resistant. vents for eaves, attics, foundations, and roof are covered with wire mesh fine enough to catch embers deck and porch materials are fire - resistant. guidelines for landscaping : keep vegetation from around windows ( heat will break glass ). keep plants farther than 5 feet ( 1. 5 m ) from walls ; this is a bare dirt no - grow zone, optional to use mowed green lawn grass and non - combustible mulch with sparse deciduous plants. keep trees from growing within 30 feet ( 9.
spawning which can result in a decrease in numbers of fish. fishing is also a cultural practice that many indigenous communities still practise today and with tpk, these communities know there can be variance in time and change of numbers of fish from one year to the next. = = indigenous and western application of traditional phenological knowledge = = tpk can be used as a predictive and management tool in both traditional indigenous practices and western practices. embracing tk and continuous observations of the physical environment creates reliable information for future generations. it pertains to the interconnectivity of animal species, plant species and human behaviour. = = = indigenous applications = = = fire management can be timed with phenological events in north - american indigenous nations. burning shrubs in vast areas would help deer find food in the next season. burning causes more water to be retained in the soil which promotes seedling sprouts in the spring and summer. for indigenous communities in california, there can be more grass growth which is used for cultural " deer grass " weaving. spring burning also promote species diversity and different cultivation such as tobacco. fire can kill fast growing vegetation and pests, and aid full - light vegetation to grow in these areas i. e. oak and huckleberries. hence, traditional knowledge and tpk can help with food security, food for wildlife. = = = western applications = = = tpk and tek are seen as sustainable practices to help fight against climate change and are starting to be recognised as a tool to help mitigate food insecurity and issues regarding biodiversity loss. a term to describe the combination of indigenous knowledge and western knowledge is known as two - eyed seeing. for instance, tpk is a tool for fire management that western communities have adopted to decrease the severity of fires. = = tpk and language = = the transmission of tpk is passed down through stories which can be in the form of indirect tpk. it is not actually observed by the eye of the learner but rather transmitted through language by family members and community members. = = sustainability and biodiversity = = conservation of the land is engrained in indigenous knowledge. practises of indigenous knowledge can be useful for sustainability and solutions for modern day environmental issues regarding climate change and biodiversity loss. tpk, tek, tk, ik are ways to look at landscape ecology in a method that also scientists and the general public can learn from. many practises can aid sustainable practises and fights
1156 floods have short and long - term negative implications to people's health and well - being. short term implications include mortalities, injuries and diseases, while long term implications include non - communicable diseases and psychosocial health aspects. for example, the 2022 pakistan floods ( which were likely more severe because of climate change ) affected people's health directly and indirectly. there were outbreaks of diseases like malaria, dengue, and other skin diseases. = = = wildfires = = = climate change increases wildfire potential and activity. climate change leads to a warmer ground temperature and its effects include earlier snowmelt dates, drier than expected vegetation, increased number of potential fire days, increased occurrence of summer droughts, and a prolonged dry season. wood smoke from wildfires produces particulate matter that has damaging effects to human health. the health effects of wildfire smoke exposure include exacerbation and development of respiratory illness such as asthma and chronic obstructive pulmonary disorder ; increased risk of lung cancer, mesothelioma and tuberculosis ; increased airway hyper - responsiveness ; changes in levels of inflammatory mediators and coagulation factors ; and respiratory tract infection. = = = storms = = = storms become wetter under climate change. these include tropical cyclones and extratropical cyclones. both the maximum and mean rainfall rates increase. this more extreme rainfall is also true for thunderstorms in some regions. furthermore, tropical cyclones and storm tracks are moving towards the poles. this means some regions will see large changes in maximum wind speeds. scientists expect there will be fewer tropical cyclones. but they expect their strength to increase. = = health risks from climate - sensitive infectious diseases = = = = health risks from changes in air quality = = = = = indoor air quality = = = indoor air pollution is known to affect the health, comfort, and well - being of building occupants. it has also been linked to sick building syndrome, respiratory issues, reduced productivity, and impaired learning in schools. indoor air quality is linked inextricably to outdoor air quality. climate change can affect indoor air quality by increasing the level of outdoor air pollutants such as ozone and particulate matter, for example through emissions from wildfires caused by extreme heat and drought. there are numerous predictions for how indoor air pollutants will change in future. models have attempted to predict how the forecasted scenarios will affect indoor air quality and indoor comfort parameters such as humidity and temperature. the net - zero challenge requires significant changes in
Answer:
|
cities
| 0.3 |
Mammals can breathe thanks to
0. organisms with roots
1. volcanoes
2. rainbows
3. oxygen tanks
found microbial communities apparently based on the products of reactions between water and the constituents of rocks. these communities have not been studied much, but may be an important part of the global carbon cycle. rock in mines two miles deep also harbour microbes ; these live on minute traces of hydrogen produced in slow oxidizing reactions inside the rock. these metabolic reactions allow life to exist in places with no oxygen or light, an environment that had previously been thought to be devoid of life. the intertidal zone and the photic zone in the oceans are relatively familiar habitat types. however the vast bulk of the ocean is inhospitable to air - breathing humans, with scuba divers limited to the upper 50 m ( 160 ft ) or so. the lower limit for photosynthesis is 100 to 200 m ( 330 to 660 ft ) and below that depth the prevailing conditions include total darkness, high pressure, little oxygen ( in some places ), scarce food resources and extreme cold. this habitat is very challenging to research, and as well as being little - studied, it is vast, with 79 % of the earth's biosphere being at depths greater than 1, 000 m ( 3, 300 ft ). with no plant life, the animals in this zone are either detritivores, reliant on food drifting down from surface layers, or they are predators, feeding on each other. some organisms are pelagic, swimming or drifting in mid - ocean, while others are benthic, living on or near the seabed. their growth rates and metabolisms tend to be slow, their eyes may be very large to detect what little illumination there is, or they may be blind and rely on other sensory inputs. a number of deep sea creatures are bioluminescent ; this serves a variety of functions including predation, protection and social recognition. in general, the bodies of animals living at great depths are adapted to high pressure environments by having pressure - resistant biomolecules and small organic molecules present in their cells known as piezolytes, which give the proteins the flexibility they need. there are also unsaturated fats in their membranes which prevent them from solidifying at low temperatures. hydrothermal vents were first discovered in the ocean depths in 1977. they result from seawater becoming heated after seeping through cracks to places where hot magma is close to the seabed. the under - water hot springs may gush forth at temperatures of over 340 Β°c ( 640 Β°f ) and support unique communities of organisms in their
##theres = = = = horseshoe bats ( of the family rhinolophidae ) are a bat genus that possess air pouches, or chambers, around their larynx which act as helmholtz resonators. the male hammerhead bat has an extremely large larynx that extends through most of his thoracic cavity, displacing his other internal organs. a pharyngeal air sac connects to a large sinus in the bat's snout ; these structures act as resonating chambers to further amplify the bat's voice. so specialized are these structures that scientists herbert lang and james chapin remarked ; " in no other mammal is everything so entirely subordinated to the organs of voice ". pinnipeds have been noted to employ this structure ; the expanded nasal chambers of elephant and hooded seals act as resonant spaces that enhance their calls. the expanded laryngeal lumen of california sea lions, the pharyngeal pouch of walrus, and the tracheal sacs of various phocids may also function in a similar manner. mysticetes, such as the blue whale, use their greatly expanded larynx as a resonant cavity. even in juveniles, the larynx is bigger than either one of the whale's lungs. this organ, along with the nasal passages, act as resonant spaces that produce the signature drawn - out calls of the baleen whales. = = = sauropsida = = = = = = = crocodylians = = = = the ghara of the indian gharial is a specialized organ that acts as a resonating chamber ; as a result, the call of a mature male can be heard up to 75 metres ( 82 yd ) away. = = = = lambeosaurines = = = = the crests of a number of lambeosaurine dinosaurs have been hypothesized to act as resonating chambers ; reconstructed upper airways, specifically, the nasal passsages of parasaurolophus, lambeosaurus, hypacrosaurus and corythosaurus have been examined, and they were concluded to be able to enhance the vocalizations in life, and the different cranial crest shapes would have distinguished the sounds produced between genera. = = = = birds = = = = the avian syrinx is the primary vocal organ in most birds, with the trachea being the primary resonator in the system. in some
ice age in the carboniferous period. this did not repeat in later ecosystems, since the carbon dioxide " locked up " in wood was returned to the atmosphere by decomposition of dead wood, but the earliest fossil evidence of fungi that can decompose wood also comes from the late devonian. the increasing depth of plants'roots led to more washing of nutrients into rivers and seas by rain. this caused algal blooms whose high consumption of oxygen caused anoxic events in deeper waters, increasing the extinction rate among deep - water animals. = = = land invertebrates = = = animals had to change their feeding and excretory systems, and most land animals developed internal fertilization of their eggs. the difference in refractive index between water and air required changes in their eyes. on the other hand, in some ways movement and breathing became easier, and the better transmission of high - frequency sounds in the air encouraged the development of hearing. the oldest animal with evidence of air - breathing, although not being the oldest myriapod fossil record, is pneumodesmus, an archipolypodan millipede from the early devonian, about 414 ma. its air - breathing, terrestrial nature is evidenced by the presence of spiracles, the openings to tracheal systems. however, some earlier trace fossils from the cambrian - ordovician boundary about 490 ma are interpreted as the tracks of large amphibious arthropods on coastal sand dunes, and may have been made by euthycarcinoids, which are thought to be evolutionary " aunts " of myriapods. other trace fossils from the late ordovician a little over 445 ma probably represent land invertebrates, and there is clear evidence of numerous arthropods on coasts and alluvial plains shortly before the silurian - devonian boundary, about 415 ma, including signs that some arthropods ate plants. arthropods were well pre - adapted to colonise land, because their existing jointed exoskeletons provided protection against desiccation, support against gravity and a means of locomotion that was not dependent on water. the fossil record of other major invertebrate groups on land is poor : none at all for non - parasitic flatworms, nematodes or nemerteans ; some parasitic nematodes have been fossilized in amber ; annelid worm fossils are known from the carboniferous, but they may still have been aquatic animals ; the earliest fossils of gastropods on
are also known in contemporary freshwater environments. these structures rarely exceed 10 cm in diameter. one former classification scheme of cyanobacterial fossils divided them into the porostromata and the spongiostromata. these are now recognized as form taxa and considered taxonomically obsolete ; however, some authors have advocated for the terms remaining informally to describe form and structure of bacterial fossils. = = = origin of photosynthesis = = = oxygenic photosynthesis only evolved once ( in prokaryotic cyanobacteria ), and all photosynthetic eukaryotes ( including all plants and algae ) have acquired this ability from endosymbiosis with cyanobacteria or their endosymbiont hosts. in other words, all the oxygen that makes the atmosphere breathable for aerobic organisms originally comes from cyanobacteria or their plastid descendants. cyanobacteria remained the principal primary producers throughout the latter half of the archean eon and most of the proterozoic eon, in part because the redox structure of the oceans favored photoautotrophs capable of nitrogen fixation. however, their population is argued to have varied considerably across this eon. archaeplastids such as green and red algae eventually surpassed cyanobacteria as major primary producers on continental shelves near the end of the neoproterozoic, but only with the mesozoic ( 251 β 65 ma ) radiations of secondary photoautotrophs such as dinoflagellates, coccolithophorids and diatoms did primary production in marine shelf waters take modern form. cyanobacteria remain critical to marine ecosystems as primary producers in oceanic gyres, as agents of biological nitrogen fixation, and, in modified form, as the plastids of marine algae. = = = origin of chloroplasts = = = primary chloroplasts are cell organelles found in some eukaryotic lineages, where they are specialized in performing photosynthesis. they are considered to have evolved from endosymbiotic cyanobacteria. after some years of debate, it is now generally accepted that the three major groups of primary endosymbiotic eukaryotes ( i. e. green plants, red algae and glaucophytes ) form one large monophyletic group called archaeplastida, which evolved after one unique endosymbiotic event. the morphological
as compared to only 15 % in non - gestating females under the same low levels of oxygen. = = = aerial respiration ( air breathing ) = = = aerial respiration is the'gulping'of air at the surface of water to directly extract oxygen from the atmosphere. aerial respiration evolved in fish that were exposed to more frequent hypoxia ; also, species that engage in aerial respiration tend to be more hypoxia tolerant than those which do not air - breath during the hypoxia. there are two main types of air breathing fish β facultative and non - facultative. under normoxic conditions facultative fish can survive without having to breathe air from the surface of the water. however, non - facultative fish must respire at the surface even in normal dissolved oxygen levels because their gills cannot extract enough oxygen from the water. many air breathing freshwater teleosts use abos to effectively extract oxygen from air while maintaining functions of the gills. abos are modified gastrointestinal tracts, gas bladders, and labyrinth organs ; they are highly vascularized and provide additional method of extracting oxygen from the air. fish also use abo for storing the retained oxygen. = = = = predation risk associated with asr and aerial respiration = = = = both asr and aerial respiration require fish to travel to the top of water column and this behaviour increases the predation risks by aerial predators or other piscivores inhabiting near the surface of the water. to cope with the increased predation risk upon surfacing, some fish perform asr or aerial respiration in schools to'dilute'the predation risk. when fish can visually detect the presence of their aerial predators, they simply refrain from surfacing, or prefer to surface in areas where they can be detected less easily ( i. e. turbid, shaded areas ). = = gill remodelling in hypoxia = = gill remodelling happens in only a few species of fish, and it involves the buildup or removal of an inter - lamellar cell mass ( ilcm ). as a response to hypoxia, some fish are able to remodel their gills to increase respiratory surface area, with some species such as goldfish doubling their lamellar surface areas in as little as 8 hours. the increased respiratory surface area comes as a trade - off with increased metabolic costs because the gills are a very important site
Answer:
|
organisms with roots
| null |
Mammals can breathe thanks to
0. organisms with roots
1. volcanoes
2. rainbows
3. oxygen tanks
found microbial communities apparently based on the products of reactions between water and the constituents of rocks. these communities have not been studied much, but may be an important part of the global carbon cycle. rock in mines two miles deep also harbour microbes ; these live on minute traces of hydrogen produced in slow oxidizing reactions inside the rock. these metabolic reactions allow life to exist in places with no oxygen or light, an environment that had previously been thought to be devoid of life. the intertidal zone and the photic zone in the oceans are relatively familiar habitat types. however the vast bulk of the ocean is inhospitable to air - breathing humans, with scuba divers limited to the upper 50 m ( 160 ft ) or so. the lower limit for photosynthesis is 100 to 200 m ( 330 to 660 ft ) and below that depth the prevailing conditions include total darkness, high pressure, little oxygen ( in some places ), scarce food resources and extreme cold. this habitat is very challenging to research, and as well as being little - studied, it is vast, with 79 % of the earth's biosphere being at depths greater than 1, 000 m ( 3, 300 ft ). with no plant life, the animals in this zone are either detritivores, reliant on food drifting down from surface layers, or they are predators, feeding on each other. some organisms are pelagic, swimming or drifting in mid - ocean, while others are benthic, living on or near the seabed. their growth rates and metabolisms tend to be slow, their eyes may be very large to detect what little illumination there is, or they may be blind and rely on other sensory inputs. a number of deep sea creatures are bioluminescent ; this serves a variety of functions including predation, protection and social recognition. in general, the bodies of animals living at great depths are adapted to high pressure environments by having pressure - resistant biomolecules and small organic molecules present in their cells known as piezolytes, which give the proteins the flexibility they need. there are also unsaturated fats in their membranes which prevent them from solidifying at low temperatures. hydrothermal vents were first discovered in the ocean depths in 1977. they result from seawater becoming heated after seeping through cracks to places where hot magma is close to the seabed. the under - water hot springs may gush forth at temperatures of over 340 Β°c ( 640 Β°f ) and support unique communities of organisms in their
##theres = = = = horseshoe bats ( of the family rhinolophidae ) are a bat genus that possess air pouches, or chambers, around their larynx which act as helmholtz resonators. the male hammerhead bat has an extremely large larynx that extends through most of his thoracic cavity, displacing his other internal organs. a pharyngeal air sac connects to a large sinus in the bat's snout ; these structures act as resonating chambers to further amplify the bat's voice. so specialized are these structures that scientists herbert lang and james chapin remarked ; " in no other mammal is everything so entirely subordinated to the organs of voice ". pinnipeds have been noted to employ this structure ; the expanded nasal chambers of elephant and hooded seals act as resonant spaces that enhance their calls. the expanded laryngeal lumen of california sea lions, the pharyngeal pouch of walrus, and the tracheal sacs of various phocids may also function in a similar manner. mysticetes, such as the blue whale, use their greatly expanded larynx as a resonant cavity. even in juveniles, the larynx is bigger than either one of the whale's lungs. this organ, along with the nasal passages, act as resonant spaces that produce the signature drawn - out calls of the baleen whales. = = = sauropsida = = = = = = = crocodylians = = = = the ghara of the indian gharial is a specialized organ that acts as a resonating chamber ; as a result, the call of a mature male can be heard up to 75 metres ( 82 yd ) away. = = = = lambeosaurines = = = = the crests of a number of lambeosaurine dinosaurs have been hypothesized to act as resonating chambers ; reconstructed upper airways, specifically, the nasal passsages of parasaurolophus, lambeosaurus, hypacrosaurus and corythosaurus have been examined, and they were concluded to be able to enhance the vocalizations in life, and the different cranial crest shapes would have distinguished the sounds produced between genera. = = = = birds = = = = the avian syrinx is the primary vocal organ in most birds, with the trachea being the primary resonator in the system. in some
ice age in the carboniferous period. this did not repeat in later ecosystems, since the carbon dioxide " locked up " in wood was returned to the atmosphere by decomposition of dead wood, but the earliest fossil evidence of fungi that can decompose wood also comes from the late devonian. the increasing depth of plants'roots led to more washing of nutrients into rivers and seas by rain. this caused algal blooms whose high consumption of oxygen caused anoxic events in deeper waters, increasing the extinction rate among deep - water animals. = = = land invertebrates = = = animals had to change their feeding and excretory systems, and most land animals developed internal fertilization of their eggs. the difference in refractive index between water and air required changes in their eyes. on the other hand, in some ways movement and breathing became easier, and the better transmission of high - frequency sounds in the air encouraged the development of hearing. the oldest animal with evidence of air - breathing, although not being the oldest myriapod fossil record, is pneumodesmus, an archipolypodan millipede from the early devonian, about 414 ma. its air - breathing, terrestrial nature is evidenced by the presence of spiracles, the openings to tracheal systems. however, some earlier trace fossils from the cambrian - ordovician boundary about 490 ma are interpreted as the tracks of large amphibious arthropods on coastal sand dunes, and may have been made by euthycarcinoids, which are thought to be evolutionary " aunts " of myriapods. other trace fossils from the late ordovician a little over 445 ma probably represent land invertebrates, and there is clear evidence of numerous arthropods on coasts and alluvial plains shortly before the silurian - devonian boundary, about 415 ma, including signs that some arthropods ate plants. arthropods were well pre - adapted to colonise land, because their existing jointed exoskeletons provided protection against desiccation, support against gravity and a means of locomotion that was not dependent on water. the fossil record of other major invertebrate groups on land is poor : none at all for non - parasitic flatworms, nematodes or nemerteans ; some parasitic nematodes have been fossilized in amber ; annelid worm fossils are known from the carboniferous, but they may still have been aquatic animals ; the earliest fossils of gastropods on
are also known in contemporary freshwater environments. these structures rarely exceed 10 cm in diameter. one former classification scheme of cyanobacterial fossils divided them into the porostromata and the spongiostromata. these are now recognized as form taxa and considered taxonomically obsolete ; however, some authors have advocated for the terms remaining informally to describe form and structure of bacterial fossils. = = = origin of photosynthesis = = = oxygenic photosynthesis only evolved once ( in prokaryotic cyanobacteria ), and all photosynthetic eukaryotes ( including all plants and algae ) have acquired this ability from endosymbiosis with cyanobacteria or their endosymbiont hosts. in other words, all the oxygen that makes the atmosphere breathable for aerobic organisms originally comes from cyanobacteria or their plastid descendants. cyanobacteria remained the principal primary producers throughout the latter half of the archean eon and most of the proterozoic eon, in part because the redox structure of the oceans favored photoautotrophs capable of nitrogen fixation. however, their population is argued to have varied considerably across this eon. archaeplastids such as green and red algae eventually surpassed cyanobacteria as major primary producers on continental shelves near the end of the neoproterozoic, but only with the mesozoic ( 251 β 65 ma ) radiations of secondary photoautotrophs such as dinoflagellates, coccolithophorids and diatoms did primary production in marine shelf waters take modern form. cyanobacteria remain critical to marine ecosystems as primary producers in oceanic gyres, as agents of biological nitrogen fixation, and, in modified form, as the plastids of marine algae. = = = origin of chloroplasts = = = primary chloroplasts are cell organelles found in some eukaryotic lineages, where they are specialized in performing photosynthesis. they are considered to have evolved from endosymbiotic cyanobacteria. after some years of debate, it is now generally accepted that the three major groups of primary endosymbiotic eukaryotes ( i. e. green plants, red algae and glaucophytes ) form one large monophyletic group called archaeplastida, which evolved after one unique endosymbiotic event. the morphological
as compared to only 15 % in non - gestating females under the same low levels of oxygen. = = = aerial respiration ( air breathing ) = = = aerial respiration is the'gulping'of air at the surface of water to directly extract oxygen from the atmosphere. aerial respiration evolved in fish that were exposed to more frequent hypoxia ; also, species that engage in aerial respiration tend to be more hypoxia tolerant than those which do not air - breath during the hypoxia. there are two main types of air breathing fish β facultative and non - facultative. under normoxic conditions facultative fish can survive without having to breathe air from the surface of the water. however, non - facultative fish must respire at the surface even in normal dissolved oxygen levels because their gills cannot extract enough oxygen from the water. many air breathing freshwater teleosts use abos to effectively extract oxygen from air while maintaining functions of the gills. abos are modified gastrointestinal tracts, gas bladders, and labyrinth organs ; they are highly vascularized and provide additional method of extracting oxygen from the air. fish also use abo for storing the retained oxygen. = = = = predation risk associated with asr and aerial respiration = = = = both asr and aerial respiration require fish to travel to the top of water column and this behaviour increases the predation risks by aerial predators or other piscivores inhabiting near the surface of the water. to cope with the increased predation risk upon surfacing, some fish perform asr or aerial respiration in schools to'dilute'the predation risk. when fish can visually detect the presence of their aerial predators, they simply refrain from surfacing, or prefer to surface in areas where they can be detected less easily ( i. e. turbid, shaded areas ). = = gill remodelling in hypoxia = = gill remodelling happens in only a few species of fish, and it involves the buildup or removal of an inter - lamellar cell mass ( ilcm ). as a response to hypoxia, some fish are able to remodel their gills to increase respiratory surface area, with some species such as goldfish doubling their lamellar surface areas in as little as 8 hours. the increased respiratory surface area comes as a trade - off with increased metabolic costs because the gills are a very important site
Answer:
|
oxygen tanks
| 0.3 |
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