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americium

(Encyclopedia)americium ămərĭˈshēəm [key], artificially produced radioactive chemical element; symbol Am; at. no. 95; mass no. of most stable isotope 243; m.p. about 1,175℃; b.p. about 2,600℃; sp. gr. 13....

electroconvulsive therapy

(Encyclopedia)electroconvulsive therapy in psychiatry, treatment of mood disorders by means of electricity; the broader term “shock therapy” also includes the use of chemical agents. The therapeutic possibiliti...

electromotive series

(Encyclopedia)electromotive series, list of metals whose order indicates the relative tendency to be oxidized, or to give up electrons (see oxidation and reduction); the list also includes the gas hydrogen. The ele...

Draghi, Mario

(Encyclopedia)Draghi, Mario mäˈēō drägˈē [key], 1947–, Italian economist and government and international ...

combustion

(Encyclopedia)combustion, rapid chemical reaction of two or more substances with a characteristic liberation of heat and light; it is commonly called burning. The burning of a fuel (e.g., wood, coal, oil, or natura...

emphysema

(Encyclopedia)emphysema ĕmfĭsēˈmə [key], pathological or physiological enlargement or overdistention of the air sacs of the lungs. A major cause of pulmonary insufficiency in chronic cigarette smokers, emphyse...

Sachs, Jeffrey David

(Encyclopedia)Sachs, Jeffrey David săks [key], 1954–, American economist, b. Detroit; grad. Harvard (B.A. 1976, M.A. 1978, Ph.D. 1980). He joined the Harvard faculty in 1980, and became a full professor three ye...

trypanosome

(Encyclopedia)trypanosome trĭpˈənəsōmˌ [key], microscopic, one-celled protozoan of the genus Trypanosoma, typically living as an active parasite in the bloodstream of a vertebrate; hundreds of species are kno...

acid rain

(Encyclopedia)acid rain or acid deposition, form of precipitation (rain, snow, sleet, or hail) containing high levels of sulfuric or nitric acids (pH below 5.5–5.6). Produced when sulfur dioxide and various nitro...

bleaching

(Encyclopedia)bleaching, process of whitening by chemicals or by exposure to sun and air, commonly applied to textiles, paper pulp, wheat flour, petroleum products, oils and fats, straw, hair, feathers, and wood. C...