- Branża: Education
- Number of terms: 13055
- Number of blossaries: 0
- Company Profile:
Founded in 1879 and named after Texas' greatest hero General Sam Houston, Sam Houston State University is public shcool within the Texas state university system and located in Huntsville, Texas.
It's a multicultural institution that offers 79 bachelorette degree programs, 54 masters and five ...
CH<sub>3</sub>Br, a volatile compound with a high mixing rate in the atmosphere. Methyl bromide escapes easily into the atmosphere where it can contribute to the depletion of ozone in the upper atmosphere. It works similarly to CFCs in its reaction with ozone molecules (O<sub>3</sub>). In the stratosphere, with the sun's UV light as a catalyst, methyl bromide breaks down and exchanges a bromide ion for oxygen from ozone. By breaking down the ozone molecules in the stratosphere, methyl bromide thins the ozone layer and lets more UV light pass through.
Industry:Chemistry; Weather
CH<sub>3</sub>Br, this halocarbon is released, to a degree, naturally from the oceans, but is more commonly released from its anthropogenic use as a soil fumigant or pesticide. Methyl bromide is persistent enough to reach the stratosphere where it photochemically decomposes to yield atomic bromine (radical) and proceeds to destroy stratospheric ozone in the same manner as the atomic chlorine radical. On an atom-for-atom basis, stratospheric bromine is more efficient at destroying ozone than is chlorine because the HBr reservoir species is more photochemically active than HCl; however, there is much less of hydrogen bromide in the stratosphere. Recent data suggest that since 1998 atmospheric concentrations have dropped 13% due the CH<sub>3</sub>Br use limitations mandated by the Montreal Protocol.
Industry:Chemistry; Weather
CH<sub>3</sub>C(=O)-CH<sub>2</sub>CH<sub>2</sub> also known as methyl ethyl ketone, 2-butanone is a product of the manufacturing of paints, glues, and other finishes because of its dissolving ability. A byproduct in the exhaust of automobiles, 2-butanone can easily evaporate into the atmosphere. It has been detected in both indoor and outdoor air. While in outdoor air it is produced by the photoxidation of certain air pollutants, such as butane and other hydrocarbons. Is known to have negative health effects when breathed in at high concentrations.
Industry:Chemistry; Weather
CH<sub>3</sub>CCl<sub>3</sub>, a synthetic organic compound that has been used as a substitute for earlier solvents that contributed to air pollution. Methyl chloroform is now known to cause destruction to stratospheric ozone and is scheduled to be phased out by the year 2005.
Industry:Chemistry; Weather
CH<sub>3</sub>CH<sub>3</sub>, a hydrocarbon found in the atmosphere whose primary fate is to react with free radicals such as chlorine and nitrous oxide. This reaction would prevent these radicals from reacting with ozone which is needed in the stratosphere to block ultraviolet light from reaching the surface of the earth.
Industry:Chemistry; Weather
CH<sub>3</sub>Cl, this compound supplies chlorine to the stratosphere by occasional volcanic eruptions and by tropospheric to stratospheric transport. Methyl chloride is also produced by seaweed. The natural chlorine content of the stratosphere as a consequence of these sources is about 0. 6 ppbv.
Industry:Chemistry; Weather
CH<sub>3</sub>OH, Classified as a VOC and introduced naturally to the atmosphere by flowering plants though plant structures and metabolic processes and by biological decomposition product of biological wastes and sewage. Also released into the atmosphere as an evaporated solvent. When oxidized it forms formaldehyde and ozone.
Industry:Chemistry; Weather
CH<sub>3</sub>SCH<sub>3</sub>, released by bacteria on the continents and in the oceans. Oxidized in the marine atmosphere to partially form cloud condensation nuclei and this may effect the formation of clouds over the oceans.
Industry:Chemistry; Weather
CH<sub>4</sub>, a colorless, odorless, flammable, greenhouse gas. It is the simplest of all hydrocarbons with a formula of CH<sub>4</sub>. Methane is released naturally into the air from anaerobic environments such as marshes, swamps, and rice fields, and from symbiotic microbes in the guts of ruminant animals (such as cattle, sheep, and camels), and sewage sludge. Methane is released from methane producing bacteria (methanogens) that live in these anaerobic places. Methanogens in termite guts are the source of methane released by termites. The discovery that termites may be a significant source of atmospheric methane is attributed to work by Patrick Zimmerman and his research group members at the National Center for Atmospheric Research in Boulder Colorado (see reference immediately below and papers in the scientific literature). Ice core data from the European Project for Ice Coring in Antarctica show that present atmospheric concentrations of CO<sub>2</sub> and CH<sub>4</sub> are the highest in the past 800,000 years as determined in the so-called Dome C ice core.
Industry:Chemistry; Weather
Change in the average global surface temperature, precipitation level, seal level, arctic sea ice, etc. Global climate change can be affected directly or indirectly by anthropogenic processes such as fossil fuel combustion and can also be influenced by natural occurrences. Most significant are changes in the atmospheric concentrations of atmospheric water vapor, CO<sub>2</sub>, CH<sub>4</sub>, N<sub>2</sub>O, and CFCs. Also see Global Warming.
Industry:Chemistry; Weather
