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degree-day

(Encyclopedia)degree-day, a unit of measure used to estimate the fuel and power requirements in heating and cooling a building; it is equal to a difference of 1 degree between the outdoor daily average temperature ...

sneeze

(Encyclopedia)sneeze, involuntary violent expiration of air through the nose and mouth. It results from stimulation of the nervous system in the nose, causing sudden contraction of the muscles of expiration. The st...

Dewar flask

(Encyclopedia)Dewar flask [for Sir James Dewar], container after which the common thermos bottle is patterned. It consists of two flasks, one placed inside the other, with a vacuum between. The vacuum prevents the ...

sprain

(Encyclopedia)sprain, stretching or wrenching of the ligaments and tendons of a joint, often with rupture of the tissues but without dislocation. Sprains occur most commonly at the ankle, knee, or wrist joints, cau...

Watson, James Dewey

(Encyclopedia)Watson, James Dewey, 1928–, American biologist and educator, b. Chicago, Ill., grad. Univ. of Chicago, 1947, Ph.D. Univ. of Indiana, 1950. With F. H. C. Crick he began (1951) research on the molecul...

Vavilov, Sergei Ivanovich

(Encyclopedia)Vavilov, Sergei Ivanovich vəvēˈləf [key], 1891–1951, Russian physicist. In 1932 he became director of the P. N. Lebedev Physical Institute, which he organized around the laboratory of the Sovie...

hotbed

(Encyclopedia)hotbed, low, glass-covered frame structure for starting tender plants. It differs from a cold frame only in that the soil is heated—either artificially as by underground electric wiring or steampipe...

Pledge of Allegiance

(Encyclopedia)Pledge of Allegiance, in full, Pledge of Allegiance to the Flag of the United States of America, oath that proclaims loyalty to the United States. and its national symbol. It reads: “I pledge allegi...

Eisenhower, Dwight David

(Encyclopedia)Eisenhower, Dwight David īˈzənhouˌər [key], 1890–1969, American general and 34th President of the United States, b. Denison, Tex.; his nickname was “Ike.” In his farewell address as pr...

Petersburg

(Encyclopedia)Petersburg, city (1990 pop. 38,386), politically independent and in no county, SE Va., on the Appomattox River; inc. 1850. A port of entry and an important tobacco market, it has industries producing ...

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