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nutation

(Encyclopedia)nutation, in astronomy, a slight wobbling motion of the earth's axis. The causes of nutation are similar to those of the precession of the equinoxes, involving the varying attraction of the moon on th...

kaolinite

(Encyclopedia)kaolinite kāˈəlĭnīt [key], clay mineral crystallizing in the monoclinic system and forming the chief constituent of china clay and kaolin. It is a hydrous aluminum silicate commonly formed by the...

quantum electrodynamics

(Encyclopedia)quantum electrodynamics (QED), quantum field theory that describes the properties of electromagnetic radiation and its interaction with electrically charged matter in the framework of quantum theory. ...

electromotive force

(Encyclopedia)electromotive force, abbr. emf, difference in electric potential, or voltage, between the terminals of a source of electricity, e.g., a battery from which no current is being drawn. When current is dr...

Duchenne, Guillaume Benjamin Amand

(Encyclopedia)Duchenne, Guillaume Benjamin Amand gēyōmˈ bäNzhämăNˈ ämäNˈ düshĕnˈ [key], 1806–75, French physician. He is noted for researches on diseases of the muscular and nervous systems and for h...

Broglie, Maurice, duc de

(Encyclopedia)Broglie, Maurice, duc de, 1875–1960, French physicist; brother of Louis Victor, duc de Broglie. His contributions include notable work on X rays and in atomic physics, radioactivity, and electricity...

Gilbert, William

(Encyclopedia)Gilbert, William, 1544–1603, English scientist and physician. He studied medicine at Cambridge (M.D., 1569), where he was elected a Fellow of St. John's College, and set up practice in London, becom...

metal

(Encyclopedia)metal, chemical element displaying certain properties by which it is normally distinguished from a nonmetal, notably its metallic luster, the capacity to lose electrons and form a positive ion, and th...

auteur

(Encyclopedia)auteur ōtörˈ [key], in film criticism, a director who so dominates the film-making process that it is appropriate to call the director the auteur, or author, of the motion picture. The auteur theor...

time and motion study

(Encyclopedia)time and motion study, analysis of the operations required to produce a manufactured article in a factory, with the aim of increasing efficiency. Each operation is studied minutely and analyzed in ord...
 

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