Refrigerant-12 and related CFCs, Refrigerant-11 and Refrigerant-22, are currently the major compounds used in the cooling and insulation systems of home refrigeration units. It has been found, however, that CFCs are posing a major threat to the global environment through their role in the destruction of the ozone layer. A search has therefore begun for replacements, and some manufacturers of CFCs have already pledged to phase out these products by the end of the century.
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A stamp depicting the image of Hanaoka Seishu. Hanaoka Seishu (1760-1835), Japanese physician and pioneer of anesthetic surgery. Hanaok... -
In the N and W United States the era of mechanized agriculture began with the invention of such farm machines as the reaper, the cultivator,...
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Fluid Mechanics, physical science dealing with the action of fluids at rest or in motion, and with applications and devices in engineering u...