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Prelog, Vladimir

(Encyclopedia)Prelog, Vladimir vlädyēˈmĭr prāˈlôg [key], 1906–98, Swiss chemist, b. Sarejevo, Austria-Hungary (now in Bosnia and Herzegovina). Educated in Prague, he worked in Yugoslavia until the German i...

polychlorinated biphenyl

(Encyclopedia)polychlorinated biphenyl or PCB, any of a group of organic compounds originally widely used in industrial processes but later found to be dangerous environmental pollutants. Polychlorinated biphenyl i...

nitric acid

(Encyclopedia)nitric acid, chemical compound, HNO3, colorless, highly corrosive, poisonous liquid that gives off choking red or yellow fumes in moist air. It is miscible with water in all proportions. It forms an a...

xenon

(Encyclopedia)xenon zēˈnŏn [key] [Gr.,=strange], gaseous chemical element; symbol Xe; at. no. 54; at. wt. 131.293; m.p. −111.9℃; b.p. −107.1℃; density 5.86 grams per liter at STP; valence usually 0. Xeno...

ammonium nitrate

(Encyclopedia)ammonium nitrate, chemical compound, NH4NO3, that exists as colorless, rhombohedral crystals at room temperature but changes to monoclinic crystals when heated above 32℃. It is extremely soluble in ...

ayahuasca

(Encyclopedia)ayahuasca or yagé, drink made by boiling various South American plants, used for centuries by shamans of traditional societies in the Amazon region in religious and healing ceremonies. It is usually ...

Masai

(Encyclopedia)Masai or Maasai mäsīˈ [key], a largely nomadic pastoral people of E Africa, chiefly in Kenya and Tanzania. Cattle and sheep form the basis of the economy that they have maintained in resistance to ...

peat

(Encyclopedia)peat, soil material consisting of partially decomposed organic matter, found mainly in swamps and bogs in various parts of the northern temperate zone but also in some semitropical and tropical region...

sweat

(Encyclopedia)sweat or perspiration, fluid secreted by the sweat glands of mammalian skin and containing water, salts, and waste products of body metabolism such as urea. The dissolved solid content of sweat is onl...

bone

(Encyclopedia)CE5 Bone bone, hard tissue that forms the skeleton of the body in vertebrate animals. In the very young, the skeleton is composed largely of cartilage and is therefore pliable, reducing the incide...