- Sektör: 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 ...
Extensive periods of time where a region suffers from lack of rain, causing dehydration for animals and plants, often resulting in crop failure. Sequential droughts during the 1930s in the United States were extremely damaging to the Great Plains, made worse by poor land management practices.
Industry:Chemistry; Weather
Family of 75 different toxic chlorinated hydrocarbons formed as by-products in chemical reactions involving chlorine and hydrocarbons, usually at high temperatures. The "premier" and probably most toxic member of the dioxin family is 2,3,7,8-Tetrachlorodibenzo-p-dioxin. Though these compounds have relatively low vapor pressures and poor solubility in water, they cycle from aquatic environments--where they have been deposited from waste incineration, wood burning, pulp bleaching, smelting, etc. ---into the atmosphere in a series of small steps, staying airborne, and atmospheric mobile, for short periods of time. Dioxins have been found in some organisms on all the earth's continents.
Industry:Chemistry; Weather
For carbon regulation, a method of decreasing carbon emissions by setting (annual) regulatory limits on large, industrial CO<sub>2</sub> emitters and fining them if they surpass that limit. Emitters that can decrease their annual CO<sub>2</sub> emissions are allowed to sell the rights to emit the balance to other emitters which can't as easily decrease emissions. These traded emission right prices are set by the market and, in theory, allow those who need to purchase the emission rights a chance to save money over the fines. Gradually the regulatory emission limits are lowered and this pushes total emissions down over time. A system like this has been in place for sulfur dioxide emissions in the US since the 1990s and for NO<sub>x</sub> since 2003.
Industry:Chemistry; Weather
For monochromatic radiation, absorbance (A) is determined by the relationship: A = abc, with a = absorptivity, b = path length through the medium, and c = concentration of the absorbing species. The intensity of a ray of light which has gone through a medium is a function of the path length through which the light passes and the concentration of absorbing matter in that medium.
Industry:Chemistry; Weather
For monochromatic radiation, absorbance (A) is determined by the relationship: A = abc, with a = absorptivity, b = path length through the medium, and c = concentration of the absorbing species. The intensity of a ray of light which has gone through a medium is a function of the path length through which the light passes and the concentration of absorbing matter in that medium.
Industry:Chemistry; Weather
Free radicals are molecules that, through photolysis or chemical reaction, have an unpaired electron in their outer valance shell. These radicals are very reactive and thus have a short life. When a free radical reacts with a more stable molecule, the radical often pulls an atom from it and becomes a stable molecule itself. The original molecule then becomes a free radical and will react with other species of atoms and molecules in a long series (or chain) of reactions until the process reaches the termination phase (see below). In this phase two free radicals combine, sharing the pair of electrons and breaking the chain.
Industry:Chemistry; Weather
Free radicals react with molecules, atoms, other radicals in long series of chain reactions. A radical is formed in the atmosphere through photolysis or chemical reaction. Radicals are very reactive and will pull atoms or electrons from other molecules to fill their outer valance shell. New radicals may formed from the original molecule which then react with another molecule, etc. This reaction propagates from one species to another until a termination reaction occurs. The termination reaction usually involves the reaction of two free radicals to form a stable product.
Industry:Chemistry; Weather
Gaseous water vapor that begins to change to tiny water droplets (a liquid state) or ice crystals when the air gets cold enough. This process begins at the dew point. Energy required to vaporize the water is released, about 585 cal/g of water at 20 degrees Celsius.
Industry:Chemistry; Weather
Granular snow that has endured a summer without melting and will transform into glacial ice.
Industry:Chemistry; Weather
H<sub>2</sub>O<sub>2</sub>, this compounds molecular weight is 34. 02g/mol; it is a colorless, rather unstable oxidant with a bitter taste and caustic to the skin. Hydrogen peroxide will decompose, liberating oxygen. Pure hydrogen peroxide is stable, but the slightest impurity will enhance decomposition, often violently. Concentrated solutions of hydrogen peroxide are highly corrosive and toxic. H<sub>2</sub>O<sub>2</sub> is used as bleach, deodorizer, and in the manufacturing of rocket fuel. The hydrogen peroxide in your bathroom is approximately 3 percent in water. In the atmosphere this is one of the oxidizers for sulfur dioxide in cloud water droplets that produces sulfuric acid, a major component in acid rain.
Industry:Chemistry; Weather
