- 업종: Education
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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 ...
A zonal circulation of the atmosphere confined to equatorial regions and driven principally by the oceanic temperature gradient. In the Pacific, air flows westward from the colder, eastern area to the warm, western ocean, where it acquires warmth and moisture and subsequently rises. A return flow aloft and subsidence over the eastern ocean complete the cell.
Industry:Chemistry; Weather
Acidified particulate matter in the atmosphere that is deposited by precipitation onto a surface, often eroding the surface away. This precipitation generally has a pH less than 5 and sometimes much lower depending on the concentration of acidic components.
Industry:Chemistry; Weather
Active chlorine can be a single chlorine atom that is a radical ("Cl dot") and therefore highly reactive. It can also be a molecule containing chlorine that is reactive (ClO). Active chlorine's most notable role in atmospheric chemistry is in catalytic destruction of ozone in the stratosphere and the accumulation of active chlorine at the earth's polar stratosphere during the polar night that leads to major ozone hole formation during the spring.
Industry:Chemistry; Weather
Air pollutants, as defined by the U. S. Clean Air Act, that present a threat to human health and/or the environment. Pollutants include asbestos, beryllium, mercury, benzene, etc. The creation of various monitoring programs set up by the Environmental Protection Agency, allow for the regulation of the required 188 hazardous air pollutants.
Industry:Chemistry; Weather
All geologic time from the beginning of Earth history to 570 million years ago. Also refers to the rocks that formed in that epoch.
Industry:Chemistry; Weather
Also called gas hydrates, formed by or having molecules which are interlaced in a lattice-like geometrical pattern.
Industry:Chemistry; Weather
Also known as ethyl alcohol or alcohol, (C<sub>2</sub>H<sub>5</sub>OH) is an oxygenated hydrocarbon that can be burned as a fuel, or blended into gasoline. Thought of as an alternative fuel and clean fuel, ethanol is a renewable energy source that is made from corn or other grains, for instance in Brazil from sugar cane. If blended into gasoline, ethanol helps with the combustion process and therefore less unburned hydrocarbons form. Ethanol blended fuels competed with methyltertbutylether (MTBE), but because of the cost and the fact MTBE can be shipped through existing pipelines, MTBE was chosen. MTBE is now being banned because of its ability to travel in ground water and the bad taste it imparts to drinking water. Because of this, ethanol is once again being put back into gasoline. The process of producing ethanol from grain requires energy. The question is: how much? Furthermore since ethanol is "less energy dense" than gasoline the same volume will produce less energy.
Industry:Chemistry; Weather
Also known as Halon-1301, this chemical with formula CBrF<sub>3</sub> is one of the most ozone destructive substances known to man. It is listed as a Class I ozone depleting chemical in the United States Clean Air Act amendments of 1990. This chemical is commonly used in fire fighting equipment used around sensitive electronic equipment such as computer rooms, telecommunication centers, and aviation equipment. It is know to cause headache and unconsciousness in humans.
Industry:Chemistry; Weather
Also known as the stratospheric aerosol layer, this is the lower layer of the stratosphere consisting of predominantly sulfuric acid/water particles with an average diameter of 0. 14 μm, discovered in 1960 by Christian Junge while examining other atmospheric components. The sulfur in this layer probably comes from a stable biogenic gas released from the earth's surface, carbonyl sulfide, O=C=S, which is photolyzed and oxidized in the stratosphere. This is a more important sulfur source for the Junge Layer than reactive sulfur gases originating from the planet's surface because their lifetimes are too short to allow transportation beyond the tropopause.
Industry:Chemistry; Weather
Also referred to as air quality index (AQI). This is a measure of different levels of concentration of air pollutants in the air. This index by another name was originally established in 1976. With each pollutant level, there is a warning depending on the concentration and its effects to the public. Alert levels can be found for any of five pollutants and the levels have color and number indicators that warn the public. The pollutants upon which the air quality index is based are ground-level ozone, particulate matter, carbon monoxide, sulfur dioxide, and nitrogen dioxide. The AQI levels are:
(>301) Maroon = Hazardous
(201-300) Purple = Very Unhealthy
(151-200) Red = Unhealthy
(101-150) Orange = Unhealthy for Sensitive Groups
(51-100) Yellow = Moderate
(0-50) Green = Good.
Industry:Chemistry; Weather
