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fatigue, in engineering

(Encyclopedia)fatigue, in engineering, microscopic cracking of materials, especially metals, after repeated applications of stress. Fissures may be formed within pieces of metal during their manufacture when, while...

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. ...

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 ...