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oscillator, electronic

(Encyclopedia)oscillator, electronic ŏsˈəlāˌtər [key], electronic circuit that produces an output signal of a specific frequency. An oscillator generally consists of an amplifier having part of its output ret...

Mahama, John Dramani

(Encyclopedia)Mahama, John Dramani drämäˈnē mähäˈmä [key], 1958–, Ghanaian political leader, grad. Univ. of Ghana, Legon (1981, 1986), Institute of Social Sciences, Moscow (1988). A member of the National...

Sarnoff, David

(Encyclopedia)Sarnoff, David, 1891–1971, American pioneer in radio and television, b. Russia. Emigrating to the United States in 1900, he worked for the Marconi Wireless Company, winning recognition as the narrat...

Lee's Summit

(Encyclopedia)Lee's Summit, city (1990 pop. 46,418), Jackson co., W Mo., in the Kansas City metropolitan area; inc. 1868. The city is an important trucking center and manufactures communications equipment, applianc...

tuning systems

(Encyclopedia)tuning systems, methods for assigning pitches to the twelve Western pitch names that constitute the octave. The term usually refers to this procedure in the tuning of keyboard instruments. The need fo...

Santiago, city, Panama

(Encyclopedia)Santiago säntyäˈgō [key], city (1990 pop. 60,959), W central Panama. Santiago is a communications and commercial center in the Pacific lowlands. It is a provincial and district capital. ...

linden, in botany

(Encyclopedia)CE5 Linden, Tilia americana linden, common name for the Tiliaceae, a family of chiefly woody shrubs and trees. Most genera are tropical, but the genus Tilia, commonly called linden, or lime tree, ...

lens, in optics

(Encyclopedia)CE5 Lenses lens, device for forming an image of an object by the refraction of light. In its simplest form it is a disk of transparent substance, commonly glass, with its two surfaces curved or wi...

Leo, in astronomy

(Encyclopedia)Leo [Lat.,=the lion], northern constellation lying S of Ursa Major and on the ecliptic (apparent path of the sun through the heavens) between Cancer and Virgo; it is one of the constellations of the z...

Larissa, in astronomy

(Encyclopedia)Larissa, in astronomy, one of the natural satellites, or moons, of Neptune. ...