- Branża: 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 measure of how efficient an emission process is. The quantum yield is a ratio of absorbed photons and photons used up in the chemical process. Quantum yield is usually dependent on temperature, pressure, and wavelength.
Industry:Chemistry; Weather
A measure of the rate of the reduction of transmitted light through a substance.
Industry:Chemistry; Weather
A measure of the value or comfort of people with the air they breathe inside buildings and homes. "Suitable" indoor air quality can conferred on air in which there are no known contaminants at harmful levels as determined by appropriate authorities or--more likely--air with which 80% or more of the people exposed do not express dissatisfaction.
Industry:Chemistry; Weather
A measurement of an atom or molecule's ability to absorb light at a specified wavelength, measured in square cm/particle.
Industry:Chemistry; Weather
A measurement of the ability to see and identify objects at different distances. Degradation of visibility is a negative effect of particulates in the environment.
Industry:Chemistry; Weather
A meteorological term used to describe a cold front where the warm winds force the cold air down at such an angle that there is no mixing and little precipitation is formed. These are often referred to as dry fronts.
Industry:Chemistry; Weather
A method of capturing carbon dioxide so that it is not released into the atmosphere. This is a proposed response to the increase of CO<sub>2</sub> in the atmosphere---mostly from anthropogenic sources since the industrial revolution. It can be achieved chemically in two obvious ways: carbon dioxide can be captured after a fossil fuel has been combusted in either the concentrated exhaust stream or, for example, carbon dioxide can be generated in fuel consumption/precombustion in the so-called syngas (synthesis gas) process which produces molecular hydrogen and CO from a methane-rich feed gas. That mix reacts with high temperature steam to produce H<sub>2</sub> and CO<sub>2</sub> which is captured. H<sub>2</sub> is burned to produce energy. Even more difficult is collecting CO<sub>2</sub> from the atmosphere at ambient concentrations in tropospheric air. Carbon dioxide produced by hydrocarbon combustion can be pressurized and injected into old salt mines or used in enhanced oil recovery.
Industry:Chemistry; Weather
A method of using electricity to break chemical bonds or cause electron exchange. An electric current passes through an electrolyte causing ions to move toward the electrodes. The positively charged electrode, called the anode, attracts anions and causes them to be oxidized. The negative electrode is called the cathode. It attracts cations which are then reduced. The electrical energy applied to the ionic solution causes a non-spontaneous process to become spontaneous. Electrolysis of water produces molecular hydrogen and molecular oxygen.
Industry:Chemistry; Weather
A molecule that is composed of two oxygen atoms, O<sub>2</sub>, and has no color, odor, or taste. It is present in both the atmosphere and dissolved in the oceans and freshwater sources exposed to the atmosphere. Solar radiation with wavelengths less then 242 nm can break it back into oxygen atoms,
O<sub>2</sub> ---> O + O
One of these oxygen radicals in turn can combine with O<sub>2</sub> to form ozone,
O<sub>2</sub> + O ---> O<sub>3</sub>
This last reactions requires quick collision with a third body to remove the excess energy of the ozone product.
Industry:Chemistry; Weather
