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electronics
electronics science and technology based on and concerned with the controlled flow of electrons or other carriers of electric charge, especially in semiconductor devices. It is one of the principal branches of electrical engineering . The invention of the transistor, announced in 1948, and the...
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Smithson Tennant
Smithson Tennant 1761-1815, English chemist. In 1796 he proved, by burning a diamond, that the diamond consists solely of carbon. In 1804 he announced his discovery of osmium and iridium.
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advertising
advertising in general, any openly sponsored offering of goods, services, or ideas through any medium of public communication. At its inception advertising was merely an announcement; for example, entrepreneurs in ancient Egypt used criers to announce ship and cargo arrivals. The invention of print...
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superconductivity
superconductivity abnormally high electrical conductivity of certain substances. The phenomenon was discovered in 1911 by Kamerlingh Onnes, who found that the resistance of mercury dropped suddenly to zero at a temperature of about 4.2°K. For the next 75 years there followed a rather steady str...
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photoelectric effect
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 of electromagnetic radiation to explain it helped lead to the development of the quantum theory . A...
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Jan Masaryk
Jan Masaryk , 1886-1948, Czechoslovak diplomat, son of Thomas G. Masaryk. He was (1925-38) Czechoslovak minister to Great Britain, and in London he became (1940) foreign minister in the Czechoslovak government in exile headed by Eduard Beneš after the German occupation of Czechoslovakia. Duri...
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Americana
Americana term used to describe material printed in or about the Americas, or written by Americans; usually restricted to the formative period in the history of the two continents. Thus the letter written by Columbus in 1493 in which he announces the discovery of the Indies is the earliest item. ...
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Angelus
Angelus [Lat.,=angel], daily prayer of the Roman Catholic Church, said usually three times daily, as announced by a bell, traditionally at six in the morning, at noon, and at six in the evening. It is said in honor of the Incarnation and consists of three repetitions of the Hail Mary together with ...
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Bay Psalm Book
Bay Psalm Book common hymnal of the Massachusetts Bay colony. Written by Richard Mather, John Eliot, and Thomas Weld, it was published in 1640 at Cambridge as The Whole Book of Psalms Faithfully Translated into English Metre. The announced effort of the authors to make a literal rendering at the ...
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Jacobus Cornelius Kapteyn
Jacobus Cornelius Kapteyn , 1851-1922, Dutch astronomer. He was an authority on the Milky Way, of which he made notable statistical studies; he constructed a model of the galaxy known as the "Kapteyn universe." He computed the positions of the stars of the Southern Hemisphere photographed by Sir...
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