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calorie

(Encyclopedia)calorie, abbr. cal, unit of heat energy in the metric system. The measurement of heat is called calorimetry. The calorie, or gram calorie, is the quantity of heat required to raise the temperature of ...

radiometer

(Encyclopedia)radiometer rāˌdēŏmˈətər [key], instrument for detection or measurement of electromagnetic radiation; the term is applied in particular to devices used to measure infrared radiation. One of the ...

spectrum

(Encyclopedia)CE5 Dispersion of white light by a triangular prism spectrum, arrangement or display of light or other form of radiation separated according to wavelength, frequency, energy, or some other propert...

Girondists

(Encyclopedia)Girondists zhērôNdăNˈ [key], political group of moderate republicans in the French Revolution, so called because the central members were deputies of the Gironde dept. Girondist leaders advocated ...

noise pollution

(Encyclopedia)noise pollution, human-created noise harmful to health or welfare. Transportation vehicles are the worst offenders, with aircraft, railroad stock, trucks, buses, automobiles, and motorcycles all produ...

Magdeburg

(Encyclopedia)Magdeburg mäkˈdəbo͝orkh [key], city (1994 pop. 270,546), capital of Saxony-Anhalt, central Germany, on the Elbe River. It is a large inland port, an industrial center, and a rail and road junction...

labor, in economics

(Encyclopedia)labor, term used both for the effort of performing a task and for the workers engaged in the activity. In ancient times much of the work was done by slaves (see slavery). In the feudal period agricult...

sleep

(Encyclopedia)sleep, resting state in which an individual becomes relatively quiescent and relatively unaware of the environment. During sleep, which is in part a period of rest and relaxation, most physiological f...

steroids

(Encyclopedia)CE5 Two examples of steroids steroids, class of lipids having a particular molecular ring structure called the cyclopentanoperhydro-phenanthrene ring system. Steroids differ from one another in th...

spring, in geology

(Encyclopedia)spring, in geology, natural flow of water from the ground or from rocks, representing an outlet for the water that has accumulated in permeable rock strata underground. Some of the water that falls as...