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fatigue, in physiology

(Encyclopedia)fatigue, in physiology, inability to perform reasonable and necessary physical or mental activity. Muscle fatigue, for example, results when the contractile properties of muscle are reduced, and conti...

elevator, in aviation

(Encyclopedia)elevator, in aviation: see airplane. ...

elevator, in machinery

(Encyclopedia)elevator, in machinery, device for transporting people or goods from one level to another. The term is applied to the enclosed structures as well as the open platforms used to provide vertical transpo...

emanation, in chemistry

(Encyclopedia)emanation: see radon.

emanation, in philosophy

(Encyclopedia)emanation ĕmənāˈshən [key] [Lat.,=flowing from], cosmological concept that explains the creation of the world by a series of radiations, or emanations, originating in the godhead. It is character...

fox, in zoology

(Encyclopedia)fox, carnivorous mammal of the dog family, found throughout most of the Northern Hemisphere. It has a pointed face, short legs, long, thick fur, and a tail about one half to two thirds as long as the ...

Islam in Africa

(Encyclopedia)Islam in Africa, the development of the Muslim religion on the African continent. During Muhammad's lifetime a group of Muslims escaped Meccan persecution (615) by fleeing to Ethiopia, where the Negus...

apostrophe, in punctuation

(Encyclopedia)apostrophe: see punctuation; abbreviation. ...

Io, in astronomy

(Encyclopedia)Io īˈō [key], in astronomy, one of the 39 known moons, or natural satellites, of Jupiter. Io is subject to Jupiter's enormous tidal forces and is, as a result, the most volcanically active body in ...

ion, in chemistry

(Encyclopedia)ion, atom or group of atoms having a net electric charge. Ionization has many applications. Vapor lamps and fluorescent lamps take advantage of the light given off when positive ions recombine with ...