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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...

student movements

(Encyclopedia)student movements, designation given to the ideas and activities of student groups involved in social protest. Historically, student movements have been in existence almost as long as universities the...

Tamil Nadu

(Encyclopedia)Tamil Nadu mədrăsˈ, mədräsˈ [key], state (2001 provisional pop. 62,110,839), 50,180 sq mi (129,966 sq km), SE India, on the Bay of Bengal. The capital is Chennai (formerly Madras). On a low-lyin...

air forces

(Encyclopedia)air forces, those portions of a nation's military organization employing heavier-than-air aircraft for reconnaissance, support of ground troops, aerial combat, and bombing of enemy lines of communicat...

carbon

(Encyclopedia)CE5 The three solid forms of pure carbon: In the diamond crystal each carbon atom is surrounded symmetrically by four other carbons (at each of the four corners of a tetrahedron). In the graphite c...

Sumatra

(Encyclopedia)Sumatra so͝omäˈtrə [key], island (1990 pop. 36,471,731), c.183,000 sq mi (473,970 sq km), Indonesia, in the Indian Ocean along the equator, S and W of the Malay Peninsula (from which it is separat...

atom

(Encyclopedia)CE5 Bohr-Rutherford atom CE5 Probability distribution of the electron in the hydrogen atom: A. Ground state B. Highly excited state atom [Gr.,=uncuttable (indivisible)], basic unit of matte...

Union of Soviet Socialist Republics

(Encyclopedia)Union of Soviet Socialist Republics (USSR), Rus. Soyuz Sovetskikh Sotsialisticheskikh Respublik, former republic. It was established in 1922 and dissolved in 1991. The Soviet Union was the first state...

Aleutian Islands

(Encyclopedia)Aleutian Islands əlo͞oˈshən [key], chain of rugged, volcanic islands curving c.1,200 mi (1,900 km) west from the tip of the Alaska Peninsula and approaching Russia's Komandorski Islands. A partial...

engineering

(Encyclopedia)engineering, profession devoted to designing, constructing, and operating the structures, machines, and other devices of industry and everyday life. Until the Industrial Revolution there were only t...