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Iliescu, Ion

(Encyclopedia)Iliescu, Ion, 1930–, Romanian political leader, president of Romania (1990–96, 2000–2004). A member of the Communist party from 1953, he held a series of party posts before he was elected a memb...

field-ion microscope

(Encyclopedia)field-ion microscope: see microscope. ...

Maurer, Ion Gheorghe

(Encyclopedia)Maurer, Ion Gheorghe yôn gāôrˈgā [key], 1902–2000, Romanian statesman. A lawyer, he defended Romanian Communists in the 1930s and later became (1945) a member of the central committee of the Co...

Compton effect

(Encyclopedia)Compton effect [for A. H. Compton], increase in the wavelengths of X rays and gamma rays when they collide with and are scattered from loosely bound electrons in matter. This effect provides strong ve...

Peltier effect

(Encyclopedia)Peltier effect pĕlˈtyā [key]: see thermoelectricity. ...

piezoelectric effect

(Encyclopedia)piezoelectric effect pīēˌzōĭlĕkˈtrĭk [key], voltage produced between surfaces of a solid dielectric (nonconducting substance) when a mechanical stress is applied to it. A small current may be ...

Raman effect

(Encyclopedia)Raman effect räˈmən [key], appearance of additional lines in the spectrum of monochromatic light that has been scattered by a transparent material medium. The effect was discovered by C. V. Raman i...

Coriolis effect

(Encyclopedia)Coriolis effect kôrˌē-ōˈlĭs [key] [for G.-G. de Coriolis, a French mathematician], tendency for any moving body on or above the earth's surface, e.g., an ocean current or an artillery round, to ...

photoelectric effect

(Encyclopedia)photoelectric effect, emission of electrons by substances, especially metals, when light falls on their surfaces. The effect was discovered by H. R. Hertz in 1887. The failure of the classical theory ...

Hall effect

(Encyclopedia)Hall effect, experiment that shows the sign of the charge carriers in a conductor. In 1879 E. H. Hall discovered that when he placed a metal strip carrying a current in a magnetic field, a voltage dif...