- Branche: 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 oceans cover approximately 70% of the Earth's surface and are apparently unique in the solar system (although keep an eye on some of the giant planets' moons. . . ). The oceans are important for the regulation of tropospheric heat and the storage and production of oxygen and carbon dioxide.
Industry:Chemistry; Weather
The outer, rigid shell of the Earth, situated above the asthenosphere and containing the crust, continents and plates.
Industry:Chemistry; Weather
The outermost electrons of an atom that are in the orbitals of highest principal quantum number of all electrons in the atom and don't fill that orbital completely.
Industry:Chemistry; Weather
The outermost shell of the atmosphere, between the mesosphere and outer space; where temperatures increase steadily with altitude. This begins at about 100 km altitude at a temperature of about -75 degrees C.
Industry:Chemistry; Weather
The outflow of charged particles from the solar corona into space. Because of the high temperature of the particles of the corona (mostly protons and electrons), they are moving at speeds higher than the solar escape velocity. At the orbit of the Earth, these particles are moving at about 500 km/sec. Some of these particles are captured by the magnetic fields of the planets, forming their magnetospheres.
Industry:Chemistry; Weather
The overall increase of the Earth's atmospheric temperature due to a buildup of greenhouse gases. In spring 2007 research predicted that the earth's Arctic Ocean might be completely ice-free at the end of the summer by the year 2020; however, ice would return in the winter. In 2010 research posed that September Arctic ice thickness was changing by >10% per decade. See also Global Climate Change.
Industry:Chemistry; Weather
The ozone concentration in the troposphere is directly related to the pollutants that are in the air and the time of day. For example, during the early hours of the day many pollutants are released into the air. As the day progresses, the sun becomes more overhead and the concentration of the sunlight increases. This solar radiation causes chemical reactions to occur and the primary pollutants decrease while the concentration of ozone increases. Eventually the ozone breaks back down and the process is ready to proceed the next day.
Industry:Chemistry; Weather
The ozone hole refers to the total amount of ozone in the atmosphere over Antarctica that was discovered to be decreasing at an alarming rate. The hole was discovered over an observation site in Antarctica by J. C. Farman, B. G. Gardiner and J. D. Shanklin. There is extensive evidence showing that chlorine originating from a class of synthetic compounds, the chlorofluorocarbons (CFCs), is responsible for the destruction of the ozone layer. CFCs are molecules that contain one or more atoms of both chlorine and fluorine. In September of 2006, the ozone hole over Antarctica was the largest area ever recorded and was almost THREE times larger than the area of the U. S. Because CFCs are so unreactive, they do not break down when released into the air in the troposphere where they are spilled. In time, air currents and diffusion carry them into the stratosphere, where, under the influence of UV radiation, they release chlorine radicals that initiate the destruction of ozone. Data collected by NASA have shown, conclusively, that there is an inverse relationship between ozone concentration and the chlorine monoxide radical in the stratosphere; ClO is formed by chlorine atom attack on O<sub>3</sub>. CFCs are very useful inert, nontoxic, nonflammable compounds that had been used for years as coolants and as spray can propellants for aerosol forms of hair sprays and deodorants. They had been unsurpassed as solvents for cleaning electronic microcircuits. Commercially, the most important CFCs are the halogenated methanes, Freon-11 (trichlorofluoromethane) and Freon-12 (dichlorodifluoromethane). Over 50% of asthma inhalers contain chlorofluorocarbons as the solvent and gaseous propellent. These CFCs have relatively recently been prohibited in all products except in those medicinal inhaler dispensers for asthmatics and a few other limited exceptions. In Finland alone there are over a million medicinal dispensers that disperse freons into the atmosphere. This is equal to the freon concentration of the cooling devices in approximately l00,000 refrigerators. See Antarctic Ozone Hole for much more.
Industry:Chemistry; Weather
The period of Earth's history from about 2 million years ago to the present; also, the rocks and deposits of that age.
Industry:Chemistry; Weather
The phenomenon in which outgoing infrared radiation that would normally exit from a planet's atmosphere but instead, is trapped or reflected because of the presence of the atmosphere and its components (see below) is called the greenhouse effect. It has been calculated that this effect is necessary to maintain the earth's climate and surface temperature and, more importantly, the liquid state of water in the majority of the earth's biosphere; however, the best scientific estimates to date suggest that increasing amounts of greenhouse gases are resulting in higher temperatures worldwide. This could result in melting of icecaps that would raise the sea level and cause devastating floods in coastal areas, more extremes in rainfall and intensity, and the distribution of species in the biosphere.
Industry:Chemistry; Weather
