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Doppler effect

(Encyclopedia)Doppler effect, change in the wavelength (or frequency) of energy in the form of waves, e.g., sound or light, as a result of motion of either the source or the receiver of the waves; the effect is nam...

fireproofing

(Encyclopedia)fireproofing, method of making normally combustible materials as nearly noncombustible as possible. Fireproofing generally applies to textiles and construction materials that are treated with a soluti...

Rumsfeld, Donald Henry

(Encyclopedia)Rumsfeld, Donald Henry, 1932–2021, American government official, b. Chicago, Princeton Univ. (B.A., 1954). After graduating college, Rumsfeld enliste...

work

(Encyclopedia)work, in physics and mechanics, transfer of energy by a force acting to displace a body. Work is equal to the product of the force and the distance through which it produces movement. Although both fo...

stimulant

(Encyclopedia)stimulant, any substance that causes an increase in activity in various parts of the nervous system or directly increases muscle activity. Cerebral, or psychic, stimulants act on the central nervous s...

Moscow, grand duchy of

(Encyclopedia)Moscow or Muscovy, grand duchy of, state existing in W central Russia from the late 14th to mid-16th cent., with the city of Moscow as its nucleus. Its formation and eventual ascendancy over other Rus...

glacial periods

(Encyclopedia)glacial periods, times during which large portions of the earth's surface were covered with thick glacial ice sheets. In the Pleistocene epoch, in the Carboniferous and Permian periods of the Paleozoi...

guidance and counseling

(Encyclopedia)guidance and counseling, concept that institutions, especially schools, should promote the efficient and happy lives of individuals by helping them adjust to social realities. The disruption of commun...

erosion

(Encyclopedia)erosion ĭrōˈzhən [key], general term for the processes by which the surface of the earth is constantly being worn away. The principal agents are gravity, running water, near-shore waves, ice (most...

electroencephalography

(Encyclopedia)electroencephalography əlĕkˌtrōĕnsĕfˌəlŏgˈrafē [key], science of recording and analyzing the electrical activity of the brain. Electrodes, placed on or just under the scalp, are linked to a...