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» Browse Science and Environment Term Papers
Dioxins
Number of Words: 1755 / Number of Pages: 7
... (y en la actualidad en pocos lugares en donde todavía se usa este tipo de pesticida), las dioxinas llegaron hasta nosotros no solo por el aire sino que directamente por los alimentos. Son lipofílicos, es decir solubles en las grasas y sus moléculas están unidas por enlaces fuertes que les dan una vida media entre los 7 y los 30 años, por esto se les llama moléculas persistentes. Existen una variedades de dioxinas, siendo las más tóxicas la 2,3,7,8 tetraclorodibenzodioxina (TCDD), la cual reúne a los Dibenzofuranos policlorados, las dibenzodioxinas policloradas y los bifenilos policlorados, más en gene ...
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Alchemy
Number of Words: 829 / Number of Pages: 4
... acid is a solvent of metals, and he liberated oxygen from the red oxide of mercury. The fundamental concept of stemmed from the Aristotelian doctrine that all things tend to reach perfection. Because other metals were thought to be less "perfect" than gold, it was reasonable to assume that nature formed gold out of other metals deep within the earth and that with sufficient skill and diligence an artisan could duplicate this process in the workshop. Efforts toward this goal were empirical and practical at first, but by the 4th century AD, astrology, magic, and ritual had begun to gain prominence ...
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The Importance Of The Ozone Layer
Number of Words: 765 / Number of Pages: 3
... monoxide is an ozone destroyer. There is always a certain
amount of chlorine monoxide in the atmosphere.
It is important to remember that ozone is constantly being created and
destroyed in the atmosphere. The amount of ozone in the atmosphere is based
on these reactions. There are many factors that influence the amount of
reactions like season, latitude, and solar cycle. Because of these factors
ozone can vary wildly each day. In the northern latitudes there can be up
to 40% difference than the day before. And in the equator regions, there
might be no variance at all.
Unfortunately, the Congr ...
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Copper Report
Number of Words: 297 / Number of Pages: 2
... chemical symbol. It contains 29 protons/electrons (atomic number) and 35 neutrons. It's atomic weight is 65.39. Copper is an orangy, red metal that is found in ores as a solid form. It can be found in such countries as the United States, Chile, Zambia, Zaire, Peru, and Canada. The most important copper ores are the sulfides, oxides, and carbonates. From these copper is obtained by smelting, leaching, and electrolysis. It's alloys, brass and bronze, long used, are still very important; all American coins are now copper alloys; gun metals also contain copper. The most important compounds a ...
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Lime Disease
Number of Words: 916 / Number of Pages: 4
... are contained within B. burgdorferi1. This bacteria
uses white-footed mice, mosquitoes, and deer as their hosts.
This disease does not discriminate between sex and age; male and female, as
well as old and young are affected. It is widely distributed around the world in the
temperate zones3. A person is infected when a black-legged tick imbeds itself into
them while out in the open in wodded and forested areas. This usually occurs between
the months of May and July. Tick abundance is associated with humidity, temperature,
landscape slope, forested areas with sandy soils, and the extremity ...
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Homosexual Gene
Number of Words: 369 / Number of Pages: 2
... which is controlled by a single gene, whose location is known, and who’s function we do understand.
Now scientists are attempting to find proof if the infamous “gay gene”. For years, the gay community has been trying to prove that they were “born gay” and that their lifestyle was not choice. The news media has a ridiculous double standard for the trait "sexual orientation" and every other trait. ABC's science journalist David Marash reported on Nightline that a gay gene "suggests that homosexuality may not be a choice." Marash is suggesting that unless we locate a gene for homosexuality, homosexualit ...
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Urban Heat Islands
Number of Words: 524 / Number of Pages: 2
... surfaces of the
surrounding countryside. The slow release of heat tends to keep city
temperatures higher than those of the unpaved faster cooling areas.
On clear, still nights when the heat island is pronounced, a small thermal low-
pressure area forms over the city. Sometimes a light breeze, called a country
breeze which blows from the countryside into the city. If there are major
industrial areas along the city's outskirts, pollutants are carried into the
heart of town, where they tend to concentrate.
At night, the extra warmth of the city occasionally produces a shallow unstable
layer near t ...
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Sedimentary Rocks
Number of Words: 693 / Number of Pages: 3
... size of the grains, or color.
All rock disintegrate slowly as a result of mechanical weathering and chemical weathering. Mechanical weathering is the breakdown of rock into particles without producing changes in the chemical composition of the minerals in the rock. Ice is the most important agent of mechanical weathering. Water percolates into cracks and fissures within the rock, freezes, and expands. The force exerted by the expansion is sufficient to widen cracks and break off pieces of rock. Heating and cooling of the rock, and the resulting expansion and contraction, also aids the process. Weath ...
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Comets
Number of Words: 275 / Number of Pages: 1
... is a “dirty snowball” conglomerate of ices and dust. Major proofs of the
snowball theory rest on various data. For one, of the observed gases and
meteoric particles that are ejected to provide the coma and tails of comets,
most of the gases are fragmentary molecules, or radicals, of the most common
elements in space: hydrogen, carbon, nitrogen, and oxygen. The radicals, for
example, of CH, NH, and OH may be broken away from the stable molecules CH4
(methane), NH3 (ammonia), and H2O (water), which may exist as ices or more
complex, very cold compounds in the nucleus. Another fact in support of ...
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Diabetes
Number of Words: 1271 / Number of Pages: 5
... in the blood, a condition called hyperglycemia ("hyper" = too much, "glycemia" = glucose in the blood). Hyperglycemia causes intense thirst, the need to urinate frequently, blurred vision, fatigue, and other symptoms. Over time, high blood glucose can cause very serious medical problems.
Adding up the total toll of complications, the disease is one of the nation's leading causes of death. All complications can be largely prevented by practicing what is known as "tight control," keeping your blood glucose level as close to normal as possible. This takes time and energy, but many diabetics ...
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