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fuel cell

(Encyclopedia)fuel cell, electric cell in which the chemical energy from the oxidation of a gas fuel is converted directly to electrical energy in a continuous process (see oxidation and reduction). The efficiency ...

germanium

(Encyclopedia)germanium jərmāˈnēəm [key] [from Germany], semimetallic chemical element; symbol Ge; at. no. 32; at. wt. 72.63; m.p. 937.4℃; b.p. 2,830℃; sp. gr. 5.323 at 25℃; valence +2 or +4. Pure german...

Marshall Plan

(Encyclopedia)Marshall Plan or European Recovery Program, project instituted at the Paris Economic Conference (July, 1947) to foster economic recovery in certain European countries after World War II. The Marshall ...

zoning

(Encyclopedia)zoning, legislative regulations by which a municipal government seeks to control the use of buildings and land within the municipality. It has become, in the United States, a widespread method of cont...

Pei, I. M.

(Encyclopedia)Pei, I. M. (Ieoh Ming Pei) pā [key], 1917–2019, Chinese-American architect, b. Guangzhou, China. Pei immigrated to the United States in 1935 and studied at the Univ. of Pennsylvania, the Massachuse...

Tennessee Valley Authority

(Encyclopedia)Tennessee Valley Authority (TVA), independent U.S. government corporate agency, created in 1933 by act of Congress; it is responsible for the integrated development of the Tennessee River basin. The h...

Geiger counter

(Encyclopedia)Geiger counter or Geiger-Müller (G-M) counter gīˈgər-mŭlˈər, –myo͞oˈlər [key], instrument for the detection and quantitative determination of ionizing radiation such as the alpha and beta ...

Mitchell, Joni

(Encyclopedia)Mitchell, Joni, 1943–, Canadian-American songwriter, singer, guitarist, poet, and painter, b. MacLeod (now Fort Macleod), Alta., as Roberta Joan Ander...

Turner, Tina

(Encyclopedia) Turner, Tina 1939- , African American R&B and rock singer, b. Brownsville, Tn., as Anna Mae Bullock. Turner had a turbulent childhood, with her par...

typewriter

(Encyclopedia)typewriter, instrument for producing by manual operation characters similar to those of printing. Corresponding to each key on the instrument's keyboard is a steel type. Activated through a series of ...