Miscellaneous Glass Studies

5 Miscellaneous glass studies. The reaction of minerals and glasses with aqueous fluids at low temperatures (hydrothermal alteration) is one of the most important geochemical processes occurring in the earth s crust. Hydrothermal alteration of 

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Metis161 reported a preliminary cost study on a 500-L scaled-up modular photobioreactor, and outlined the following cost distribution for the unit based on operating it for a period of 6 months photobioreactor materials, 45% mineral nutrients, 39% labor 4% water supply, 4% land lease, 2% power, 1% and miscellaneous expenses, 5%. He reported the actual cost of the materials for the pilot photobioreactor unit as 0.75 m 2, but the material used and the lifetime of the unit was not stated. This cost is much lower that the often quoted estimates of up to 100 per meter square using glass covered structures. Glass does not appear to be a realistic material to use in a commercial photobioreactor system because of both initial and replacement costs. 

Miscellaneous other uses of emission spectroscopy should be mentioned. The cement and glass industries use spectroscopic methods for quality control. The food and beverage industries monitor trace element concentrations during processing. Spectroscopy is used for forensic purposes, usually to help identify samples as to source or origin. Meteorite composition also has been studied by spectroscopic methods, as have lunar samples returned to earth by astronauts. Emission spectroscopy also has served as a research tool in chemistry and physics by providing composition information on research samples. 

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