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Chad, Lake

(Encyclopedia)Chad, Lake chăd, chäd [key], N central Africa. It lies mainly in Chad and Cameroon. Some 550 sq mi (1,425 sq km) in area in 2003, the shallow lake has been greatly reduced in size since the 1960s, w...

firefly

(Encyclopedia)firefly or lightning bug, small, luminescent, carnivorous beetle of the family Lampyridae. Fireflies are well represented in temperate regions, although the majority of species are tropical and subtro...

metallurgy

(Encyclopedia)metallurgy mĕtˈəlûrˌjē [key], science and technology of metals and their alloys. Modern metallurgical research is concerned with the preparation of radioactive metals, with obtaining metals econ...

salt, chemical compound

(Encyclopedia)salt, chemical compound (other than water) formed by a chemical reaction between an acid and a base (see acids and bases). Salts are also prepared by methods other than neutralization. A metal can c...

phosphorylation

(Encyclopedia)phosphorylation, chemical process in which a phosphate group is added to an organic molecule. In living cells phosphorylation is associated with respiration, which takes place in the cell's mitochondr...

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...

Draghi, Mario

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

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...

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....

Bernoulli's principle

(Encyclopedia)CE5 Bernoulli's principle Bernoulli's principle, physical principle formulated by Daniel Bernoulli that states that as the speed of a moving fluid (liquid or gas) increases, the pressure within th...