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Black Sea

(Encyclopedia)Black Sea, inland sea, c.159,600 sq mi (413,360 sq km), between SE Europe and Asia, connected with the Mediterranean Sea by the Bosporus, the Sea of Marmara, and the Dardanelles. It is c.750 mi (1,210...

sediment

(Encyclopedia)sediment, mineral or organic particles that are deposited by the action of wind, water, or glacial ice. These sediments can eventually form sedimentary rocks (see rock). Sediments form sedimentary ...

tin

(Encyclopedia)tin, metallic chemical element; symbol Sn [Lat. stannum]; at. no. 50; at. wt. 118.710; m.p. 231.9681℃; b.p. 2,270℃; sp. gr. 5.75 (gray), 7.3 (white); valence +2 or +4. Tin exhibits allotropy; abov...

walrus

(Encyclopedia)walrus, marine mammal, Odobenus rosmarus, found in Arctic seas. Largest of the fin-footed mammals, or pinnipeds (see seal), the walrus is also distinguished by its long tusks and by cheek pads bearing...

hair

(Encyclopedia)CE5 A. Cross section of a hair shaft B. General structure of a hair hair, slender threadlike outgrowth from the skin of mammals. In some animals hair grows in dense profusion and is called fur or ...

bearing

(Encyclopedia)bearing, machine part designed to reduce friction between moving parts or to support moving loads. There are two main kinds of bearings: the antifriction type, such as the roller bearing and the ball ...

continent

(Encyclopedia)continent, largest unit of landmasses on the earth. The continents include Eurasia (conventionally regarded as two continents, Europe and Asia), Africa, North America, South America, Australia, and An...

global warming

(Encyclopedia)global warming, the gradual increase of the temperature of the earth's lower atmosphere as a result of the increase in greenhouse gases since the Industrial Revolution. Global warming and its effects,...

digital versatile disc

(Encyclopedia)digital versatile disc or digital video disc (DVD), a small plastic disc used for the storage of digital data. The successor media to the compact disc (CD), a DVD can have more than 100 times the stor...

cortisone

(Encyclopedia)cortisone kôrˈtĭsōnˌ [key], steroid hormone whose main physiological effect is on carbohydrate metabolism. It is synthesized from cholesterol in the outer layer, or cortex, of the adrenal gland u...