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vortex

(Encyclopedia)vortex vôrˈtĕks [key], mass of fluid in whirling or rotary motion. To simplify the analysis, vortex motion usually describes motions in a frictionless fluid. In such cases the absence of friction w...

Air Force, United States Department of the

(Encyclopedia)Air Force, United States Department of the, military department within the U.S. Dept. of Defense (see Defense, United States Department of). The Air Force traces its roots to the founding of the Aeron...

hydrogen

(Encyclopedia)hydrogen hīˈdrəjən [key] [Gr.,=water forming], gaseous chemical element; symbol H; at. no. 1; interval in which at. wt. ranges 1.00784–1.00811; m.p. −259.14℃; b.p. −252.87℃; density 0.08...

Nashua

(Encyclopedia)Nashua năshˈo͞oə [key], city (1990 pop. 79,662), seat of Hillsborough co., S N.H., on the Merrimack and Nashua rivers near the Mass. line; settled c.1655, inc. as a city 1853. Because of the avail...

Anaxagoras

(Encyclopedia)Anaxagoras ănˌəksăgˈərəs [key], c.500–428 b.c., Greek philosopher of Clazomenae. He is credited with having transferred the seat of philosophy to Athens. He was closely associated with many f...

furnace

(Encyclopedia)furnace, enclosed space for the burning of fuel. There are many kinds of furnaces, the type depending upon the fuel and the use to which the heat produced within it is put. Most familiar are the furna...

specific gravity

(Encyclopedia)specific gravity, ratio of the weight of a given volume of a substance to the weight of an equal volume of some reference substance, or, equivalently, the ratio of the masses of equal volumes of the t...

cerium

(Encyclopedia)cerium sērˈēəm [key] [from the asteroid Ceres], metallic chemical element; symbol Ce; at. no. 58; at. wt. 140.116; m.p. 799℃; b.p. 3,426℃; sp. gr. 6.77 at 25℃; valence +3 or +4. Cerium is a ...

Bessemer process

(Encyclopedia)CE5 Bessemer converter Bessemer process bĕsˈəmər [key] [for Sir Henry Bessemer], industrial process for the manufacture of steel from molten pig iron. The principle involved is that of oxidati...

linoleum

(Encyclopedia)linoleum lĭnōˈlēəm [key], resilient floor or wall covering made of burlap, canvas, or felt, surfaced with a composition of wood flour, oxidized linseed oil, gums or other ingredients, and colorin...