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Earth accumulation

Carbon is a true pharmakom a poison and a gift, powering the modern world. Carbon released into the atmosphere mere years or decades ago is now being taken up by plants. But fossil carbon taken from the earth accumulated over millions of years. Carbon, then, is a temporal problem, and thus it is intimately linked with the nexus of alchemy and mining. [Pg.172]

Its importance depends on the nuclear property of being readily fissionable with neutrons and its availability in quantity. The world s nuclear-power reactors are now producing about 20,000 kg of plutonium/yr. By 1982 it was estimated that about 300,000 kg had accumulated. The various nuclear applications of plutonium are well known. 238Pu has been used in the Apollo lunar missions to power seismic and other equipment on the lunar surface. As with neptunium and uranium, plutonium metal can be prepared by reduction of the trifluoride with alkaline-earth metals. [Pg.205]

According to one theory earth and the other planets were formed almost 5 billion years ago from the gas (the solar nebula) that trailed behind the sun as It rotated Being remote from the sun s core the matter in the nebula was cooler than that in the in tenor and therefore it contracted accumulating heavier elements and becoming the series of planets that now circle the sun... [Pg.6]

Some nut trees accumulate mineral elements. Hickory nut is notable as an accumulator of aluminum compounds (30) the ash of its leaves contains up to 37.5% of AI2O2, compared with only 0.032% of aluminum oxide in the ash of the Fnglish walnut s autumn leaves. As an accumulator of rare-earth elements, hickory greatly exceeds all other plants their leaves show up to 2296 ppm of rare earths (scandium, yttrium, lanthanum, dysprosium, holmium, erbium, thulium, ytterbium, and lutetium). The amounts of rare-earth elements found in parts of the hickory nut are kernels, at 5 ppm shells, at 7 ppm and shucks, at 17 ppm. The kernel of the Bra2d nut contains large amounts of barium in an insoluble form when the nut is eaten, barium dissolves in the hydrochloric acid of the stomach. [Pg.272]

Polymers with much higher average molecular weights, from 90,000 to 4 x 10 , are formed by a process of coordinate anionic polymerization (43—45). The patent Hterature describes numerous organometaUic compounds, aLkaline-earth compounds, and mixtures as polymerization catalysts. Iron oxides that accumulate in ethylene oxide storage vessels also catalyze polymerization. This leads to the formation of nonvolatile residue (NVR) no inhibitor has been found (46). [Pg.453]

Natural Gas Natural gas is a combustible gas that occurs in porous rock of the earth s crust and is found with or near accumulations of crude oil. It may occur alone in separate reservoirs, but more commonly it forms a gas cap entrapped between petroleum and an impervious, capping rock layer in a petroleum reservoir. Under high-pressure conditions, it is mixed with or dissolved in crude oil. Natural gas termed dry has less than 0.013 dmVm (0.1 gaLlOOO fF) of gasoline. Above this amount, it is termed wet. [Pg.2365]

Land, vegetation, and bodies of water are the surfaces on which acidic deposition accumulates. Bodies of fresh water represent the smallest proportion of the earth s surface area available for acidic deposition. Yet, the best-known effect is acidification of freshwater aquatic systems. [Pg.152]

The handle of the bucket was covered with plastic. When acetone was drained into the bucket, a static charge accumulated on the acetone and on the bucket. The plastic prevented the charge from flowing to earth via the drain pipe, which was grounded. Finally a spark passed between the bucket and the drain valve, and the acetone caught fire. [Pg.291]

In cyanobacteria and the eukaryotic photosynthetic cells of algae and higher plants, HgA is HgO, as implied earlier, and 2 A is O,. The accumulation of O, to constitute 20% of the earth s atmosphere is the direct result of eons of global oxygenic photosynthesis. [Pg.713]

The noble gases make up about 1% of the earth s atmosphere in which their major component is At. Smaller concentrations are occluded in igneous rocks, but the atmosphere is the principal commercial source of Ne, Ar, Kr and Xe, which are obtained as by-products of the liquefaction and separation of air (p. 604). Some Ar is also obtained from synthetic ammonia plants in which it accumulates after entering as impurity in the N2 and H2 feeds. World production of... [Pg.889]

Not only is geology important in exploring for hydrocarbons, but also engineers must study the present composition and structure of the earth to successfully drill the borehole itself. Further, once hydrocarbons have been found and have proven to be economically recoverable, studies of the physical and chemical aspects of earth in such regions are important to the follow-on production and reservoir engineering. These studies help ensure that the accumulated hydrocarbons are recovered in an economic manner [24],... [Pg.240]

Igneous rocks are the original rocks of the earth and were solidified from the molten mixture of materials that made up the earth prior to its cooling. Igneous rocks are very complex a.ssemblages of minerals. Usually such rocks are very dense and have very few pores (or voids) which can accumulate or pass any type of fluid. [Pg.240]

Tar sands (oil sands) are large deposits of sand saturated with bitumen and water. Tar sand deposits are commonly found at or near the earth s surface entrapped in large sedimentary basins. Large accumulations of tar sand deposits are few. About 98% of all world tar sand is found in... [Pg.24]

The name dust , is used in a variety of ways, and with different meanings. These range from the material that accumulates on the earth s surface, such as on streets and in living and working environments, to the particulate material suspended in the atmosphere. In this paper I wish to consider these two materials in terms of their chemical composition, sources and relationship between them. The names used for the two materials will be surface dust and atmospheric dust . The word aerosol may also be used for atmospheric dust but it more properly applies to the finer particles of atmospheric dust and includes liquid aerosol (i). Botfi surface and atmospheric dusts are increasingly seen to be a hazard to human beings as they are a source of intake of toxic materials such as heavy metals. For this reason study is important of the composition and sources of the dusts. [Pg.117]

Records of past environmental change are preserved in a broad range of Earth materials. Past environments are inferred from "proxy" records, meaning measurements of physical and chemical parameters of marine and terrestrial sediment, polar ice, and other materials that were in some way influenced by their environment during accumulation. Examples of proxy records are the distribution of glacial deposits, the isotopic composition of terrestrial and marine sediments and ice, the abundance and species composition of plant and animal fossils, and the width of tree rings. [Pg.459]

Marcantonio F, Anderson RF, Higgins S, Stute M, Schlosser P, Kubik PW (2001b) Sediment focusing in the central equatorial Pacific Ocean. Paleoceanography 16(3) 260-267 Marcantonio F, Kumar N, Stute M, Anderson RF, Seidl MA, Schlosser P, Mix A (1995) A comparative study of accumulation rates derived by He and Th isotope analysis of marine sediments. Earth Planet. Sci. Letters 133 549-555... [Pg.527]

Griin R, Thome A (1997) Dating the Ngandong humans. Science 276 1575 Hille P (1979) An open system model for uranium series dating. Earth Planet Sci Lett 42 138-142 Ikeya M (1982) A model of linear uranium accumulation for ESR age of Heidelberg (Mauer) and Tautavel bones. Jap J App Phys (Lett) 21 690-692... [Pg.627]


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See also in sourсe #XX -- [ Pg.605 ]




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