- Industry: 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 ...
The rate of continuous change, flow or movement of liquid, particles or energy. The rate of discharge of a liquid, removal of energy or particle depositing from one body to another. For example, flux emissions of sesqiterpines from vegetation was estimated to be 10-40 mg per square meter in a summer month of the western and southern US states.
Industry:Chemistry; Weather
Using the wind to turn a windmill blade to generate electricity. The blades collect the wind's energy as it goes over the blades because they slow down the speed of the wind; the blades are spun and the wind is slowed. The blades are connected to a drive shaft which is turning an electric generator to produce electricity.
Industry:Chemistry; Weather
These are organic chemicals that have a very high vapor pressure and low solubility in water under normal atmospheric conditions. They tend to be much more concentrated as an indoor pollutant because of the numerous household items that contain them. Exposure to these VOCs can lead to eye, nose, throat irritation, headaches, nausea, and even liver damage. In polluted urban environments these compounds can contribute to the production of ozone.
Industry:Chemistry; Weather
This describes a condition in which there is equilibrium in a photochemical reaction. For this condition to take place the rate of photodissociation or rate of chemical reaction of one or more of the reactants has to be equal to the rate of their recombination or reformation. The reactions producing ozone in the atmosphere under certain conditions are described this way. For instance, the three important tropospheric reaction involving the formation and consumption of ozone are:
O<sub>3</sub> + NO -------> O<sub>2</sub> + NO<sub>2</sub> (ozone consumption by NO)
NO<sub>2</sub> + hv -------> O + NO (NO<sub>2</sub> photolysis)
O<sub>2</sub> + O ----M---> O<sub>3</sub> (ozone formation)
At night in the clean troposphere, the concentration of NO is very low and so O<sub>3</sub> consumption is very slow, and therefore ozone's concentration stays relatively constant overnight even though ozone is no longer being produced. Likewise in polluted, urban settings at night, as before, ozone is no longer being produced but NO's concentration at the end of the day can be quite high, and so O<sub>3</sub> in that setting can be completely destroyed overnight. There are, therefore, some concentrations of NO, NO<sub>2</sub>, sunlight, and O<sub>3</sub> that would interact according to the equations above--and given tropospheric reaction rates and sunlight intensities--would yield a constant concentration of ozone. This would be the photostationary state concentration of ozone; however, it is important to note that this concentration--if no other reagents are considered and at normal tropospheric temperatures and sunlight intensities--is too low to account for the common ground-level ozone concentrations routinely found in polluted cites like Houston, Texas or Beijing, China. Instead, there must be other means of NO oxidation to NO<sub>2</sub> besides oxidation by ozone ocurring to produce the O<sub>3</sub> levels that are wide spread in highly polluted environments. And there are: peroxy compounds like methyl peroxy radical, hydroperoxy radical, and other volatile organic compounds are also involved in reactions that yield ozone in cities all over the planet.
Industry:Chemistry; Weather
The rate of decrease of temperature with increasing altitude in the atmosphere. If heat is neither gained nor lost from the air parcel under consideration, then the lapse rate is said to be adiabatic. For air parcels of differing water content this value is different. In the troposphere, these two values are generally inversely proportional: increasing altitude means a lower temperature until the tropopause is reached. When altitude increases and temperature decreases, the lapse rate is considered positive, and for unsaturated tropospheric air this is approximately 9. 8 degrees C/km; however, in an inversion layer the atmospheric lapse rate is negative, that is, the atmosphere's temperature warms with increasing altitude.
Industry:Chemistry; Weather
These are gases in the atmosphere that do not occur in large quantities but are significant to life on Earth or are important constituents of the chemical cycles in the atmosphere.
Industry:Chemistry; Weather
This spectral band in the UV is responsible for the absorption and filtering of solar ultraviolet radiation. Photons with a wavelength longer than 210 nm are weakly absorbed by oxygen in the atmosphere. Ozone then becomes the major UV absorber, with a band of 210-380 nm. Compare to ozone's Chappuis band in the visible wavelength region.
Industry:Chemistry; Weather
Three dimensional computer simulations of climate and weather which, through calculations, are used to investigate gravity wave fields. The models may help to predict atmospheric chemistry distribution and meteorological trends for the future.
Industry:Chemistry; Weather
This is the pressure at sea-level (the average level of the ocean over the entire earth). The average sea-level air pressure is 1,013 millibars, 760 mm Hg, 101 kilopascals, 29. 92 inch of mercury, 14. 7 lb/ sq in, or 1. 00 atmosphere. The normal range of sea level air pressure worldwide is 970-1040 millibars.
Industry:Chemistry; Weather
These are clouds found in the stratospheric region of the atmosphere. Unlike the moisture laden troposphere, the stratosphere is almost moisture free. A lack of moisture means that cloud formation in the stratosphere is a relatively uncommon occurrence. Because of the very low temperatures, nacreous clouds, a type of stratospheric cloud, occur during winter conditions at the higher latitudes. A second type of stratospheric cloud, called a polar stratospheric cloud (PSC), occurs in the polar regions during winter and early spring. Polar stratospheric clouds are of particular interest to scientists studying the Antarctic Ozone Hole. Polar stratospheric clouds form under extremely cold conditions, whereby nitric acid, water vapor and other trace chemicals freeze to form ice crystals. PSCs provide a solid surface on which chlorine-containing reservoir compounds can gather, and on this surface the chemical reactions involved in the depletion of ozone are greatly increased. Science; v292; 61-63; 2001. `
Industry:Chemistry; Weather
