Light artificial/solar

Application of heterogeneous photocatalysis to water and air purification appears a particularly convenient method in the cases of easily accessible UV light (mainly solar, but also artificial) and diluted pollutants. H02-based photocatalysis offers unique possibilities of mineralization of most organic compounds and, in addition, sterilization. This type of AOP useful for water and air purification has been studied and developed extensively over the last few decades. UV light, especially as a part of solar radiation, must be used to activate this process. In addition oxygen and water are indispensable. 

Li, Y.Z., D.S. Hwang, N.H. Lee and S.J. Kim (2005c). Synthesis and characterization of carbon-doped titania as an artificial solar light sensitive photocatalyst. Chemical Physics Letters, 404(1-3), 25-29. 

The fungicides carboxin (5,6-dihydro-2-methyl-l,4-oxathi-ine-3-carboxani-lide) (V) and oxycarboxin (5,6-dihydro-2-methyl-l,4-oxathi-ine-3-carboxani-lide-4,4-dioxide) (VI) were photolysed in artificial solar light (A. >290nm) in pure water and in the presence of soil-extracted humic and fulvic acids (Scheyern, Germany) (1 mg IT1) [69]. 

Shapiro and Robertson (59, 60) evaluated 79 dyes as solar radiation protectants for spsy moth, Lymantria dispar nucieopolyhedrovirus (Ivertical distance of 50 cm from the light bulb (intensity). Congo red was die only dye tested that fully retain LdMNPV activity after artificial solar radiation exposure. Solar protectants absorbed at 280-320 nm (UV-B), as well as 320-400 nm (UV-A) (Table 3). 

Type of illuminations artificial light or solar light... 

P aerugineum is a unicellular alga cultured under artificial or solar light in a freshwater medium supplied with CO2, in an outdoor bioreactor developed by Arad and Yaron. Algal growth was optimized for yield and for the properties of the blue color produced. The parameters that require close monitoring are light intensity and temperature, in order to avoid stress conditions that result in decreased color yield and solubility and increased biosynthesis of the polysaccharides that encapsulate the cells and are excreted into the medium. 

It responds well to a wide range of hydrocarbon fires and is blind to welding arcs except when very close to the detector. It can see through smoke and other contaminates that could blind a UV detector. It generally ignores lightning, electrical arcs and other forms of radiation. It is blind to solar radiation and resistant to most forms of artificial lighting. 

Warnings are often given that acceleration factors for relating artificial light sources with service are meaningless, because of both the variation in solar irradiation and the variation in spectral distribution. Regardless of this, acceleration factors are estimated, and indeed have to be if any extrapolation from accelerated tests is to be made. 

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