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Ultraviolet radiation, also known as simply UV, is electromagnetic radiation of wavelengths of 10–400 nanometers, shorter than that of visible light, but longer than X-rays. UV radiation is present in sunlight , and constitutes about 10% of the total electromagnetic radiation output from the Sun.
Thermophotovoltaic (TPV) energy conversion is a direct conversion process from heat to electricity via photons.A basic thermophotovoltaic system consists of a hot object emitting thermal radiation and a photovoltaic cell similar to a solar cell but tuned to the spectrum being emitted from the hot object.
Photochemical immersion well reactor (50 mL) with a mercury-vapor lamp.. Photochemistry is the branch of chemistry concerned with the chemical effects of light. Generally, this term is used to describe a chemical reaction caused by absorption of ultraviolet (wavelength from 100 to 400 nm), visible (400–750 nm), or infrared radiation (750–2500 nm).
Laser pumping lamps. The top three are xenon flashlamps while the bottom one is a krypton arc lamp External triggering was used in this extremely fast discharge. Due to the very high speed, (3.5 microseconds), the current is not only unable to fully heat the xenon and fill the tube, but is still in direct contact with the glass.
It may be broadly defined to include all radiation with a wavelength of 0.1μm and 5.0μm or narrowly defined so as to include only radiation between 0.2μm and 3.0μm. There is little radiation flux (in terms of W/m 2 ) to the Earth's surface below 0.2μm or above 3.0μm, although photon flux remains significant as far as 6.0μm, compared to ...
The thermosphere (or the upper atmosphere) is the height region above 85 kilometres (53 mi), while the region between the tropopause and the mesopause is the middle atmosphere (stratosphere and mesosphere) where absorption of solar UV radiation generates the temperature maximum near an altitude of 45 kilometres (28 mi) and causes the ozone layer.
Extreme ultraviolet composite image of the Sun (red: 21.1 nm, green: 19.3 nm, blue: 17.1 nm) taken by the Solar Dynamics Observatory on August 1, 2010 13.5 nm extreme ultraviolet light is used commercially for photolithography as part of the semiconductor fabrication process. This image shows an early, experimental tool.
Variations in the ultraviolet component. The UV component varies by more than the total, so if UV were for some (as yet unknown) reason to have a disproportionate effect, this might explain a larger solar signal. Effects mediated by changes in galactic cosmic rays (which are affected by the solar wind) such as changes in cloud cover.