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The best known explanation of the oxygen effect is the oxygen fixation hypothesis developed by Alexander in 1962, [9] which posited that radiation-induced non-restorable or "fixed" nuclear DNA lesions are lethal to cells in the presence of diatomic oxygen. [10] [11] Recent hypotheses include one based on oxygen-enhanced damage from first ...
Path loss, or path attenuation, is the reduction in power density (attenuation) of an electromagnetic wave as it propagates through space. [1] Path loss is a major component in the analysis and design of the link budget of a telecommunication system. This term is commonly used in wireless communications and signal propagation.
The International Telecommunication Union has a very detailed documentation for absorption behavior encountered in the radio bands and spectroscopic data for oxygen and water vapor. [9] In water vapor: Resonance peak at 22.24 GHz, 1.35 cm, for which there is a K band (IEEE) in radio; 183 GHz; In oxygen:
For example, air has a refractive index of 1.0002793 at atmospheric pressure, where there are about 2 × 10 25 molecules per cubic meter, and therefore the major constituent of the atmosphere, nitrogen, has a Rayleigh cross section of 5.1 × 10 −31 m 2 at a wavelength of 532 nm (green light). [14]
An estimated value of ~ gives an increase in global temperature of about 1.6 K above the 1750 reference temperature due to the increase in CO 2 over that time (278 to 405 ppm, for a forcing of 2.0 W/m 2), and predicts a further warming of 1.4 K above present temperatures if the CO 2 mixing ratio in the atmosphere were to become double its pre ...
Up until the 1940s, astronomers used optical telescopes to observe distant astronomical objects whose radiation reached the earth through the optical window. After that time, the development of radio telescopes gave rise to the more successful field of radio astronomy that is based on the analysis of observations made through the radio window .
In the case of global energy flux, the W/m 2 value is obtained by dividing the total energy flow over the surface of the globe (measured in watts) by the surface area of the Earth, 5.1 × 10 14 m 2 (5.1 × 10 8 km 2; 2.0 × 10 8 sq mi). [3]
In ice cores, mainly Arctic and Antarctic, the ratio of 18 O to 16 O (known as δ 18 O) can be used to determine the temperature of precipitation through time.Assuming that atmospheric circulation and elevation has not changed significantly over the poles, the temperature of ice formation can be calculated as equilibrium fractionation between phases of water that is known for different ...