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duralumin

(Encyclopedia)duralumin do͝orălˈyəmĭn, dyo͝o– [key], alloy of aluminum (over 90%) with copper (about 4%), magnesium (0.5%–1%), and manganese (less than l%). Before a final heat treatment the alloy is duct...

Eustathius, Saint

(Encyclopedia)Eustathius, Saint yo͞ostāˈthēəs [key], c.280–c.335, patriarch of Antioch (324?–330?), leader at the First Council of Nicaea. He was deposed and exiled by a faction led by Eusebius of Nicomedi...

lake, in dyeing

(Encyclopedia)lake, in dyeing, an insoluble pigment formed by the reaction between an organic dye and a mordant. The color of a lake depends upon the mordant as well as the dye used. Generally, lakes are not as col...

Smith, Theobald

(Encyclopedia)Smith, Theobald, 1859–1934, American pathologist, b. Albany, N.Y., M.D. Albany Medical College, 1883. He was professor of bacteriology at Columbian (now George Washington) Univ. (1886–95) and of c...

stress test

(Encyclopedia)stress test or exercise electrocardiography, in medicine, a test that evaluates the performance of the heart by subjecting it to controlled amounts of physical stress. Such tests, which include walkin...

Pettenkofer, Max von

(Encyclopedia)Pettenkofer, Max von mäks fən pĕtˈənkōˌfər [key], 1818–1901, German chemist and hygienist. He studied medicine at Munich. Pettenkofer is considered a founder of epidemiology and is known for...

Thermidor

(Encyclopedia)Thermidor thûrˈmĭdôr, Fr. tĕrmēdôrˈ [key], 11th month of the French Revolutionary calendar. The coup of 9 Thermidor (July 27, 1794) marked the downfall of Robespierre and the end of the Reign ...

centripetal force and centrifugal force

(Encyclopedia)CE5 Centripetal and centrifugal forces: When a ball is swung in a circle at the end of a string, centripetal and centrifugal forces act as shown above. centripetal force and centrifugal force, act...

Rh factor

(Encyclopedia)Rh factor, protein substance present in the red blood cells of most people, capable of inducing intense antigenic reactions. The Rh, or rhesus, factor was discovered in 1940 by K. Landsteiner and A. S...

Zewail, Ahmed Hassan

(Encyclopedia)Zewail, Ahmed Hassan, 1946–2016, Egyptian-American chemist, b. Damanhur, Egypt, Ph.D. Univ. of Pennsylvania, 1974. He became a U.S. citizen in 1982. A professor at the California Institute of Techno...