- 産業: 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 ...
Defined as a SI unit which expresses a unit of energy. 1 J = 1 kg*m<sup>2</sup>/s<sup>2</sup>.
Industry:Chemistry; Weather
Defined as an instrument utilized to determine the amount of dust particles in a sample of air.
Industry:Chemistry; Weather
Deposit of powder-like substance over the ground surface; especially effecting plant leaves; that when contacted by water has a very low pH.
Industry:Chemistry; Weather
Deposit of powder-like substance over the ground surface; especially effecting plant leaves; that when contacted by water has a very low pH.
Industry:Chemistry; Weather
Determined by the daily weather interactions over many years. Characteristics used in determining climate are temperature, precipitation, humidity, sunshine, and cloudiness, wind, and air pressure. Climatologists describe climate in terms of average temperature and precipitation amounts.
Industry:Chemistry; Weather
During a solar eclipse the moon completely blocks the sun from shining on the Earth. In the umbra, the source of light is completely blocked by the moon causing the shadow on the Earth.
Industry:Chemistry; Weather
Emitted during the burning of coal, diesel fuel, natural gas and biomass and is part of the composition of soot. Black Carbon can absorb and reflect sunlight cooling the Earth’s surface, but also increase solar energy absorbed in the atmosphere, warming it. These effects are thought to effect global climate and rainfall cycles. Black carbon increases the effect of global warming, visibility problems, and health problems.
Industry:Chemistry; Weather
Energy that is emitted in the form of electromagnetic waves at a wavelength greater than about 750 up to approximately 30,000 nanometers. Although the earth absorbs almost all the IR, UV, and visible radiation the hits it, the surface of the earth emits only the longest wavelength radiation of these three, IR, in any significant amounts. It is this re-emission of IR towards space--and its subsequent absorbance, re-emission and scattering--that contributes to the process that heats the atmosphere. This re-emission and subsequent heating is a part of the greenhouse effect.
Industry:Chemistry; Weather
Energy that is emitted in the form of electromagnetic waves with a wavelength of 1-380nm, which is composed of UV-A, UV-B, and UV-C light; UV-A light being the longest wavelength and having the smallest energy and UV-C light being the shortest wavelength and having the highest energy. All UV-C light and most UV-B light is filtered out of the atmosphere via the ozone layer. However, UV-A light travels to the surface of the earth.
Industry:Chemistry; Weather
Establishing the relative age of various materials with the use of carbon-14. This involves measuring the amount of <sup>14</sup>C and of <sup>12</sup>C and comparing the measured ratio to the one established by the production of <sup>14</sup>C in the upper atmosphere by cosmic rays. When an organism is alive, the <sup>14</sup>C/ <sup>12</sup>C ratio in its biomass is constant (because of constant atmospheric <sup>14</sup>C production, diffusion to the lower atmosphere, absorption and incorporation by organisms, and because of constant <sup>14</sup>C radioactive decay); however, when the organism dies, the ratio begins to change---at a very predictable rate---because the (dead) organism is no longer incorporating new carbon. Therefore knowing the carbon-14/carbon-12 ratio now in some artifact gives a very good measure of how long the carbon has been "dead. " The object however must obviously have organic material either in it or on it for this dating method to work. Also the length of time one can "look back" in time is limited because the amount of carbon-14 must be detected with some certainty for the age to be known with confidence, and the longer the sample has been dead the less <sup>14</sup>C is present because it is continually decaying.
Industry:Chemistry; Weather
