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chain reaction

(Encyclopedia)CE5 Chain reaction: A neutron (n) strikes the uranium nucleus (U-235), causing it to split into fission products A and B and release two neutrons. These neutrons can in turn cause further fissions....

Shatt al Arab

(Encyclopedia)Shatt al Arab shät äl äˈräb [key], tidal river, 120 mi (193 km) long, formed by the confluence of the Tigris and Euphrates rivers, flowing SE to the Persian Gulf, forming part of the Iraq-Iran bo...

Etowah

(Encyclopedia)Etowah ĕtˈəwôˌ, āˈtə– [key], river, 141 mi (227 km) long, rising in the Blue Ridge Mts., N Ga., and flowing SW to Rome, Ga., where it joins the Oostanaula River to form the Coosa. Allatoona ...

Fort William Henry

(Encyclopedia)Fort William Henry, at the southern end of Lake George, NE N.Y.; built by the English in 1755. In 1757, during the last conflict of the French and Indian Wars, it was captured and destroyed by the Fre...

intrauterine device

(Encyclopedia)intrauterine device (IUD), variously shaped birth control device, usually of plastic, which is inserted into the uterus by a physician. The IUD may contain copper or levonorgestrel, a progestin (a hor...

Ilemi Triangle

(Encyclopedia)Ilemi Triangle, triangular-shaped region, c.10,000 sq km (3,860 sq mi) in area, at the NW corner of Lake Turkana, E Africa. It borders South Sudan (W), Ethiopia (E) and Kenya (S). A disputed territory...

antihistamine

(Encyclopedia)antihistamine ănˌtĭhĭsˈtəmēn [key], any one of a group of compounds having various chemical structures and characterized by the ability to antagonize the effects of histamine. Their principal u...

Fleming, Peggy

(Encyclopedia)Fleming, Peggy, 1948–, American ice skater, b. San Jose, Calif. She began skating at age 9, and after distinguished accomplishments as a juvenile and novice skater, she was U.S. Ladies Champion from...

José Tomás

(Encyclopedia)José Tomás (José Tomás Román Martín), 1975–, Spanish matador. Though he first entered the bullring in Spain, he became a full-fledged matador in Mexico City after having gone there to gain exp...

Moscow, city, United States

(Encyclopedia)Moscow mŏsˈkō [key], city (1990 pop. 18,519), seat of Latah co., NW Idaho, at the Wash. line; inc. 1887. It is a trade center for a lumber and farm area where wheat, peas, lentils, and dairy items ...