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direction finder

(Encyclopedia)direction finder, electronic device used to determine the position of a ship or aircraft. In a simple direction finder a radio receiver is equipped with a revolving directional antenna. The antenna re...

expert system

(Encyclopedia)expert system, a computer system or program that uses artificial intelligence techniques to solve problems that ordinarily require a knowledgeable human. The method used to construct such systems, kno...

acetate

(Encyclopedia)acetate ăsˈĭtātˌ [key], one of the most important forms of artificial cellulose-based fibers; the ester of acetic acid. The first patents for the production of fibers from cellulose acetate appea...

Roanne

(Encyclopedia)Roanne rôänˈ [key], town (1990 pop. 42,848), Loire dept., E central France, on the Loire River. Cotton and metals are the chief products; other industries include tanning, machine and vehicle manuf...

Pedersen, Charles John

(Encyclopedia)Pedersen, Charles John, 1904–89, American chemist, b. Busan, Korea, M.S. Massachusetts Institute of Technology, 1927. After finishing his studies, Pedersen began work as a research chemist for the D...

Fort Peck Dam

(Encyclopedia)Fort Peck Dam, 21,430 ft (6,531 m) long and 250 ft (76 m) high, on the Missouri River, NE Mont.; one of the world's largest earth-filled dams. The dam was built (1933–40) by the U.S. Army Corps of E...

oasis

(Encyclopedia)oasis ōāˈsĭs [key], an area within a desert where the water table reaches the surface, with enough moisture to permit the growth of vegetation. The water may come up to the surface in springs, or ...

Whipple, Fred Lawrence

(Encyclopedia)Whipple, Fred Lawrence, 1906–2004, American astronomer, b. Red Oak, Iowa. After graduating from the Univ. of California, Berkeley (Ph.D. 1931), he accepted a position at Harvard, where he remained f...

bionics

(Encyclopedia)bionics, the study of living systems with the intention of applying their principles to the design of engineering systems. Drawing on interdisciplinary research in the mechanical and life sciences, bi...

Pointe-Noire

(Encyclopedia)Pointe-Noire pwăNt-nwär [key], city (1984 pop. 294,203), SW Republic of the Congo, Africa, a port on the Atlantic Ocean. Offshore oil drilling and oil refining are the city's most important economic...