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rennet

(Encyclopedia)rennet, substance containing rennin, an enzyme having the property of clotting, or curdling, milk. It is used in the making of cheese and junket. Rennet is obtained from the stomachs of young mammals ...

Yost, Ed

(Encyclopedia)Yost, Ed (Paul Edward Yost), 1919–2007, American balloonist, b. Bristow, Iowa, grad. Boeing School of Aeronautics, 1940. The father of modern hot-air ballooning, Yost pioneered the used of propane (...

chemical reaction

(Encyclopedia)chemical reaction, process by which one or more substances may be transformed into one or more new substances. Energy is released or is absorbed, but no loss in total molecular weight occurs. When, fo...

Lindemann, Frederick Alexander

(Encyclopedia)Lindemann, Frederick Alexander (Viscount Cherwell) lĭnˈdəmən, chärˈwĕl [key], 1886–1957, British physicist and government official. He studied with W. H. Nernst and developed with him the Ner...

Lomonosov, Mikhail Vasilyevich

(Encyclopedia)Lomonosov, Mikhail Vasilyevich mēkhəyēlˈ vəsēˈlyəvĭch ləmənôˈsəf [key], 1711–65, Russian scientist, scholar, and writer, an outstanding figure in 18th-century Russia. Lomonosov was the...

kiln

(Encyclopedia)kiln kĭl, kĭln [key], furnace for firing pottery and enamels, for making brick, charcoal, lime, and cement, for roasting ores, and for drying various substances (e.g., lumber, chemicals). Kilns may ...

Haber process

(Encyclopedia)Haber process häˈbər [key], commercial process for the synthesis of ammonia, NH3. Pure hydrogen and nitrogen gases are mixed in the appropriate proportion, heated to between 450℃ and 600℃, comp...

eczema

(Encyclopedia)eczema ĕkˈsəmə [key], acute or chronic skin disease characterized by redness, itching, serum-filled blisters, crusting, and scaling. Predisposing factors are familial history of allergic disorders...

fire clay

(Encyclopedia)fire clay, clay that has a high degree of resistance to heat. By the best standards it should have a fusion point higher than 1,600℃. The term “fire clay” is commonly held to exclude kaolin and ...

firing

(Encyclopedia)firing, process of treating clay or other plastic ceramic materials with heat to produce a hard, durable but brittle material such as pottery. Primitive potters baked their clay in an open fire, but f...