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petrochemical

(Encyclopedia)petrochemical, any one of a large group of chemicals derived from a component of petroleum or natural gas. The cracking processes for manufacturing gasoline produce vast quantities of gaseous hydrocar...

Virginia Polytechnic Institute and State University

(Encyclopedia)Virginia Polytechnic Institute and State University, better known as Virginia Tech, at Blacksburg; land-grant and state supported; coeducational; chartered and opened 1872 as an agricultural and mecha...

sodium thiosulfate

(Encyclopedia)sodium thiosulfate, Na2S2O3, colorless crystalline compound that is more familiar as the pentahydrate, Na2S2O3·5H2O, an efflorescent, monoclinic crystalline substance also called sodium hyposulfite o...

digestive system

(Encyclopedia)CE5 Digestive system digestive system, in the animal kingdom, a group of organs functioning in digestion and assimilation of food and elimination of wastes. Virtually all animals have a digestive ...

Avogadro's number

(Encyclopedia)Avogadro's number ävōgäˈdrō [key] [for Amedeo Avogadro], number of particles contained in one mole of any substance; it is equal to 602,252,000,000,000,000,000,000, or in scientific notation, 6.0...

electret

(Encyclopedia)electret, solid electrically insulating, or dielectric, material that has acquired a long-lasting electrostatic polarization. Electrets are produced by heating certain dielectric materials to a high t...

liquefaction

(Encyclopedia)liquefaction, change of a substance from the solid or the gaseous state to the liquid state. Since the different states of matter correspond to different amounts of energy of the molecules making up t...

Greenpeace

(Encyclopedia)Greenpeace, international organization that promotes environmental awareness and addresses environmental abuse through direct, nonviolent confrontations with governments and companies. Founded in 1971...

Jaisalmer

(Encyclopedia)Jaisalmer jəsälˈmər [key], former principality, Rajasthan state, NW India. Its terrain is largely a sandy or stony waste and constitutes a section of the Thar Desert. Jaisalmer was brought under t...

gallium

(Encyclopedia)gallium gălˈēəm [key], metallic chemical element; symbol Ga; at. no. 31; at. wt. 69.723; m.p. 29.78℃; b.p. 2,403℃; sp. gr. 5.904 at 29.6℃ (solid), 6.095 at 29.8℃ (liquid); valence +2 or +3...