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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 ...

Piazzolla, Ástor Pantaleón

(Encyclopedia)Piazzolla, Ástor Pantaleón, 1921–92, Argentinian composer and player of the bandoneón (a large accordionlike instrument), b. Mar del Plata. He spent much of his childhood in New York, returned (1...

voltmeter

(Encyclopedia)voltmeter, instrument used to measure differences of electric potential, commonly called voltage, in volts or units that are multiples or fractions of volts. A voltmeter is usually combined with an am...

Steinmetz, Charles Proteus

(Encyclopedia)Steinmetz, Charles Proteus stīnˈmĕts [key], 1865–1923, American electrical engineer, b. Breslau, Germany, studied at the Univ. of Breslau. Forced to flee Germany because of his socialist activiti...

bus

(Encyclopedia)bus [Lat. omnibus=for all], large public conveyance. A horse-drawn urban omnibus was introduced in Paris in 1662 by Blaise Pascal and his associates, but it remained in operation for only a few years....

Lenz's law

(Encyclopedia)Lenz's law, physical law, discovered by the German scientist H. F. E. Lenz in 1834, that states that the electromotive force (emf) induced in a conductor moving perpendicular to a magnetic field tends...

Langmuir, Irving

(Encyclopedia)Langmuir, Irving lăngˈmyo͞or [key], 1881–1957, American chemist, b. Brooklyn, N.Y. Associated (1909–50) with the research laboratory of the General Electric Company, he introduced atomic-hydrog...

asphyxia

(Encyclopedia)asphyxia ăsfĭkˈsēə [key], deficiency of oxygen and excess of carbon dioxide in the blood and body tissues. Asphyxia, often referred to as suffocation, usually results from an interruption of brea...

graphite

(Encyclopedia)graphite grăfˈīt [key], an allotropic form of carbon, known also as plumbago and black lead. It is dark gray or black, crystalline (often in the form of slippery scales), greasy, and soft, with a m...

Charters, Samuel Barclay

(Encyclopedia)Charters, Samuel Barclay, 1929–2015, American musical historian and author, b. Pittsburgh. In the 1950s he studied jazz and blues in New Orleans and traveled through the South, where he recorded neg...