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grease

(Encyclopedia)grease, mixture of lubricant and thickener. It is used to reduce friction between surfaces from which oils would leak away or cause damage by dripping, or where lubrication must be assured for extende...

Moissan, Henri Ferdinand Frederick

(Encyclopedia)Moissan, Henri Ferdinand Frederick, 1852–1907, French chemist, Ph.D. École Pratique des Haute Études, Paris, 1880. Moissan was a professor at the School of Pharmacy in Paris (1886–1900) and at t...

rare earths

(Encyclopedia)rare earths, in chemistry, oxides of the rare-earth metals. They were once thought to be elements themselves. They are widely distributed in the earth's crust and are fairly abundant, although they we...

gills, in biology

(Encyclopedia)CE5 Gills of a fish: Side view (A) and ventral view (B) gills, external respiratory organs of most aquatic animals. In fishes the gills are located in gill chambers at the rear of the mouth (phary...

blackbody

(Encyclopedia)blackbody, in physics, an ideal black substance that absorbs all and reflects none of the radiant energy falling on it. Lampblack, or powdered carbon, which reflects less than 2% of the radiation fall...

iron

(Encyclopedia)iron, metallic chemical element; symbol Fe [Lat. ferrum]; at. no. 26; at. wt. 55.845; m.p. about 1,535℃; b.p. about 2,750℃; sp. gr. 7.87 at 20℃; valence +2, +3, +4, or +6. Iron is biologically s...

global warming

(Encyclopedia)global warming, the gradual increase of the temperature of the earth's lower atmosphere as a result of the increase in greenhouse gases since the Industrial Revolution. Global warming and its effects,...

Haldane, John Scott

(Encyclopedia)Haldane, John Scott, 1860–1936, British scientist, b. Edinburgh; father of John Burdon Sanderson Haldane. He made many important contributions to mine safety, investigating principally the action of...

Libby, Willard Frank

(Encyclopedia)Libby, Willard Frank, 1908–80, American chemist, b. Grand Valley, Colo., grad. Univ. of California (B.S., 1931; Ph.D., 1933). He taught (1933–45) at the Univ. of California and was a chemist (1941...

capillary

(Encyclopedia)capillary kăpˈəlĕrˌē [key], microscopic blood vessel, smallest unit of the circulatory system. Capillaries form a network of tiny tubes throughout the body, connecting arterioles (smallest arter...