Có 40+ tài liệu thuộc chủ đề "nghiên cứu môi trường"
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gon, far more abundant in Earth’s atmosphere than any of the other noble (inert) gases, is a by-product of the radioactive decay of an isotope of potassium. Earth’s sur- face, warmed by the absorption of solar radiation, conducts heat into the lowest portion of the atmo- sphere. Virtually all the phenomena that are com- monly referred to as “weather” occur...
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However, begin- ning in the 1950’s, international economic factors and changes in farming methods led to larger farms being more economically viable than small ones. Different types of farming are concentrated mainly in the areas that suit them best, depending on water availability and climatic conditions. About 90 percent of all cattle are used for beef. Queensland and New South...
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can only be given to this type of beer brewed in the small Pajottenland region of Belgium. Nearly half of the beer brewed in Belgium is exported, mostly to Canada, France, Germany, Italy, Spain, the United States, and the United Kingdom.. During the seventeenth century, when the Low Coun- tries were ruled by Spain, Spanish conquistadores brought cacao beans back...
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Butanol can be produced by the fermentation of sugars similar to the ethanol production. The biological production by fermentation is not economically attractive because of low levels of product concentrations and high cost of product re- covery compared to the chemical process.. Beginning in 2008, a majority of fuel stations in the United States were selling gasoline with 10 percent...
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The biome concept finds use in the biosphere reserve program, which is based on environmental planning aimed at saving substantial portions of each unique biome.. Energy Entering the Biosphere. The biosphere concept serves an accounting function by placing all living systems on one enclosed “space- ship Earth”—a concept that became far easier for the public to visualize when the space...
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With a rarity akin to that of silver, bismuth is a rela- tively minor component of the Earth’s crust. It is one of three elements that is less dense in the solid phase than in the liquid. The earliest recorded use of bismuth was in the mid- 1400’s as an alloying material in casting type. German scientist Georgius Agricola stated...
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Brazil is one of the top-ten producers of textiles.. In 2007, coffee was grown on 2.3 million hectares, mainly in the states of São Paulo and Minas Gerais, with a production of 2.2 million metric tons. Oranges were cultivated on 0.8 million hectare, mostly in the state of São Paulo, from which 18.2 mil- lion metric tons were produced. Cattle...
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Solar panels, or modules, are one of the most promising sources of inexpensive and environmen- tally safe energy. The phenomenon was dis- covered in the eighteenth century and studied by Al- bert Einstein in the 1920’s. After the widespread adoption of silicon for circuitry in the twentieth cen- tury, photovoltaic cells became less expensive to pro- duce and more efficient...
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Calcium is the fifth most abundant element in the Earth’s crust, of which it makes up roughly 3.6 per- cent. Limestone, largely or entirely composed of calcium carbonate, is generally formed by the deposition and consolidation of the skeletons of invertebrate marine organisms, although some limestones are the result of chemical precipita- tion from solution. Dolostone, composed chiefly of the...
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In command economies, markets are subordinated to the authority of the state. Private property conveys to the owners of capital and resources the right to use their property regard- less of the impact on society or nature. More recently, property refers not to the use of the property but rather to its value. Clearing waterways and digging canals reduced the...
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Chalk is made of the shells of microscopic floating or- ganisms which once lived in the sea. Sodium carbonate minerals are present in associa- tion with dry salt lake deposits in some parts of the world. The most important use of calcite is in the production of cements and lime. The raw materials are ground together, and the mixture is...
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The element cesium makes up only 7 parts per million of the Earth’s crust. Cesium has significant applications in the manufac- ture of photoelectric cells and vacuum tubes. The In- ternational Atomic Energy Agency has also identified cesium 137 as one of the radioactive materials that may be used to make “dirty bombs.”. it may explode in the presence of...
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cubic meters, or almost equal to China’s total annual runoff.. The total hydrological power reserve is esti- mated at 680 million kilowatts, ranking first in the world. Of the total, 380 million kilowatts can be devel- oped to generate 1.9 trillion kilowatt-hours of electric- ity, which contribute a great deal to China’s economic development and the world economy.. China’s vast...
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Clean Air Act. The Clean Air Acts of 1963 and 1970, with subse- quent amendments, are intended to improve air qual- ity in the United States, largely through mandated air quality standards.. The 1963 Clean Air Act (CAA) and its 1965 amend- ments attempted to improve air quality in the United States through federal support of air pollution re- search...
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presence of which would ordinarily cause decay of the plant tissue. A layer of peat in excess of 2 meters in thickness and cov- ering more than 5,000 square kilometers is present in the Dismal Swamp of coastal North Carolina and Vir- ginia.. Such a sequence of rock deposited during a single advance and retreat of the shoreline, termed a...
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Cobalt is widely distributed in the Earth’s crust in many ores, but only a few are of commercial value. The world’s major sources are in the Democratic Re- public of the Congo, Australia, Canada, Zambia, Rus- sia, and Cuba.. Cobalt (abbreviated Co), atomic number 27, belongs to Group VIII of the transition elements of the peri- odic table and resembles...
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“Conservation” generally refers to the use of re- sources found in the natural environment in such a way that the resources will serve humans effectively and will be available to humans for as long as possible.. Humans alter the natural cycling of energy and flow of matter in the Earth’s ecosystem. Natu- ral resources are all of the things that...
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The emphasis of the program is to create synergies and partnerships among the stakeholders in ways that are pro-poor, gender equitable, and envi- ronmentally sustainable.. The major uses of copper are in the electrical industry because of the substance’s ability to conduct electric-. Copper is also utilized extensively in the construction industry especially for plumbing. Most of the remaining copper...
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By 3400 b.c.e., the fossil record shows a marked change in corn, notably increased cob and kernel size, indicating greater domestication.. Extensive attempts at hybridization began in the late nineteenth century, but the increase in yield was usually a disappointing 10 percent or so. One of the hybridizers of the 1920’s was Henry A. Dry milling is a simpler process,...
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The pri- mary function of most dams is to smooth out or regu- late flows downstream of the dam. Flood-control objectives dictate that a dam’s reservoir be as empty as possible so that any excess water from the watershed (the area upstream of the dam that sheds water to it) can be detained or re- tained in the reservoir to...