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isomorphism

(Encyclopedia)isomorphism īˌsəmôrˈfĭzəm [key], of minerals, similarity of crystal structure between two or more distinct substances. Sodium nitrate and calcium sulfate are isomorphous, as are the sulfates of...

elasticity

(Encyclopedia)elasticity, the ability of a body to resist a distorting influence or stress and to return to its original size and shape when the stress is removed. All solids are elastic for small enough deformatio...

wheel

(Encyclopedia)wheel. Through the many millennia of the Paleolithic period and the Neolithic period no use of the wheel was known to humans. Its use was not known to the Native Americans until the Europeans introduc...

caoutchouc

(Encyclopedia)caoutchouc kouˈcho͝ok [key], natural rubber obtained as a latex from various tropical plants, e.g., the Pará rubber tree. It is much more elastic than balata or gutta-percha. It is the most familia...

Castle, Wendell

(Encyclopedia)Castle, Wendell, 1932–2018, American furniture designer, b. Emporia, Kans., grad. Univ. of Kansas (B.F.A. 1958, M.F.A. 1961). Trained as an industrial designer and sculptor, he became the preeminent...

Bourbaki, Nicolas

(Encyclopedia)Bourbaki, Nicolas, pseudonym under which a group of 20th cent. mathematicians has written a series of treatises on pure mathematics. The mathematicians have all been associated with the Ecole Normale ...

tomato

(Encyclopedia)tomato, plant (Lycopersicon esculentum) of the family Solanaceae (nightshade family), related to the potato and eggplant. Although cultivated in Mexico and Peru for centuries before the European conqu...

Sennacherib

(Encyclopedia)Sennacherib sĕnăkˈərĭb [key] or Senherib, d. 681 b.c., king of Assyria (705–681 b.c.). The son of Sargon, Sennacherib spent most of his reign fighting to maintain the empire established by his ...

fatigue, in physiology

(Encyclopedia)fatigue, in physiology, inability to perform reasonable and necessary physical or mental activity. Muscle fatigue, for example, results when the contractile properties of muscle are reduced, and conti...

umbilical cord

(Encyclopedia)umbilical cord ŭmbĭlˈĭkəl [key], cordlike structure about 22 in. (56 cm) long in the pregnant human female, extending from the abdominal wall of the fetus to the placenta. Its chief function is t...