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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...

soapstone

(Encyclopedia)soapstone or steatite stēˈətīt [key], metamorphic rock of which the characteristic and usually chief mineral is talc, but which also contains varying parts of chlorite, mica, tremolite, quartz, ma...

silicon carbide

(Encyclopedia)silicon carbide, chemical compound, SiC, that forms extremely hard, dark, iridescent crystals that are insoluble in water and other common solvents. Widely used as an abrasive, it is marketed under su...

turquoise

(Encyclopedia)turquoise, hydrous phosphate of aluminum and copper, Al2(OH)3PO4·H2O+Cu, used as a gem. It occurs rarely in crystal form, but is usually cryptocrystalline. Turquoise is opaque and has a waxy luster; ...