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hydrophone

(Encyclopedia)hydrophone hīˈdrəfōnˌ [key], device that receives underwater sound waves and converts them to electrical energy; the voltage generated can then be read on a meter or played through a loudspeaker....

Dryopithecus

(Encyclopedia)Dryopithecus drīˌōpəthēˈkəs, –pĭthˈəkəs [key], an extinct group of apes. Fossils about 20 million years old have been found in Africa, Asia, and Europe. Dryopithecus had a semierect postu...

celestial horizon

(Encyclopedia)celestial horizon, one axis of the altazimuth coordinate system. It is the great circle on the celestial sphere midway between the observer's zenith and nadir; it divides the celestial sphere into two...

neuralgia

(Encyclopedia)neuralgia no͝orălˈjə, nyo͝o– [key], acute paroxysmal pain along a peripheral sensory nerve. Unlike neuritis, there is no inflammation or degeneration of nerve tissue. Neuralgia occurs commonly ...

local area network

(Encyclopedia)local area network (LAN), a computer network dedicated to sharing data among several single-user workstations or personal computers, each of which is called a node. A LAN can have from two to several ...

scale, in cartography

(Encyclopedia)scale, in cartography, the ratio of the distance between two points on a map to the real distance between the two corresponding points portrayed. The scale may be expressed in three ways: numerically,...

cross-laminated timber

(Encyclopedia)cross-laminated timber (CLT), manufactured wood panels that consist of layers of boards glued together under pressure with the grain of the boards in one layer running perpendicular to the grain in ad...

chickenpox

(Encyclopedia)chickenpox or varicella vârˌəsĕlˈə [key], infectious disease usually occurring in childhood. It is caused by the same herpesvirus, varicella-zoster, that produces shingles; the virus can hide in...

popular sovereignty

(Encyclopedia)popular sovereignty, in U.S. history, doctrine under which the status of slavery in the territories was to be determined by the settlers themselves. Although the doctrine won wide support as a means o...

heatstroke

(Encyclopedia)heatstroke, profound disturbance of the heat-regulating mechanism of the body, also known as sunstroke. It is characterized by extremely high body temperatures and sometimes by convulsions and coma. T...