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granite

(Encyclopedia)granite, coarse-grained igneous rock of even texture and light color, composed chiefly of quartz and feldspars. It usually contains small quantities of mica or hornblende, and minor accessory minerals...

Purvey, John

(Encyclopedia)Purvey, John, c.1354–c.1421, English scholar, who in support of the Lollardry movement completed the first thorough translation of the Bible into English. Becoming associated with John Wyclif at Oxf...

forging

(Encyclopedia)forging, shaping metal by heating it and then hammering or rolling it. Forging is the method by which metal was first worked when it came into use about 4000 b.c. in Egypt and Asia. Modern forging is ...

hydrogenation

(Encyclopedia)hydrogenation hīdrôjˈənāˌshən, hīˌdrəjənāˈshən [key], chemical reaction of a substance with molecular hydrogen, usually in the presence of a catalyst. A common hydrogenation is the harde...

injection

(Encyclopedia)injection, introduction of a fluid into the body, usually by means of a needle and syringe. The material injected may be a test substance (as in determining allergic sensitivity or immunity to a disea...

sonic boom

(Encyclopedia)CE5 Sonic boom wave pattern from a supersonic aircraft and variation in pressure sonic boom, shock wave produced by an object moving through the air at supersonic speed, i.e., faster than the spee...

Bergström, Sune Karl

(Encyclopedia)Bergström, Sune Karl so͞oˈnə, bĕrˈyəström [key], 1916–2004, Swedish biochemist, grad. Karolinska Institute (Ph.D., M.D., 1944). With his former pupil B. I. Samuelsson and John R. Vane, he wa...

tire

(Encyclopedia)tire, device made of rubber and fabric and attached to the outer rim of a vehicle wheel. Solid rubber tires were in limited use before 1850; they are still used in some special applications, e.g., for...

nicotine

(Encyclopedia)nicotine, C10H14N2, poisonous, pale yellow, oily liquid alkaloid with a pungent odor and an acrid taste. It turns brown on exposure to air. Nicotine, a naturally occurring constituent of tobacco, is t...

liquefaction

(Encyclopedia)liquefaction, change of a substance from the solid or the gaseous state to the liquid state. Since the different states of matter correspond to different amounts of energy of the molecules making up t...