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pump

(Encyclopedia)pump, device to lift, transfer, or increase the pressure of a fluid (gas or liquid) or to create a vacuum in an enclosed space by the removal of a gas (see vacuum pumps under vacuum). The centrifugal ...

proton

(Encyclopedia)proton, elementary particle having a single positive electrical charge and constituting the nucleus of the ordinary hydrogen atom. The positive charge of the nucleus of any atom is due to its protons....

earth, in geology and astronomy

(Encyclopedia)CE5 A. Cross section of the earth, showing its shells B. Detailed cross section of the crust and upper mantle: The lithosphere consists of the hard rock in the crust and upper mantle, lying above t...

Sung

(Encyclopedia)Sung so͝ong [key], dynasty of China that ruled 960–1279. It was divided into two periods: Northern Sung (907–1126) with its capital at Kaifeng and Southern Sung (1127–1279) with its capital at ...

ion, in chemistry

(Encyclopedia)ion, atom or group of atoms having a net electric charge. Ionization has many applications. Vapor lamps and fluorescent lamps take advantage of the light given off when positive ions recombine with ...

voice, sound produced by living beings

(Encyclopedia)voice, sound produced by living beings. The source of the sound in human speaking and singing is the vibration of the vocal cords, which are inside the larynx, and the production of the sounds is call...

quasicrystal

(Encyclopedia)quasicrystal kwāˈzīkrĭsˌtəl, kwäzˈē– [key] or quasiperiodic solid, solid body that exhibits such crystalline features as symmetry and repeating patterns of unit cells (regular arrangements ...

nuclear reactor

(Encyclopedia)CE5 Power reactor system nuclear reactor, device for producing controlled release of nuclear energy. Reactors can be used for research or for power production. A research reactor is designed to pr...

Deep Sea Drilling Project

(Encyclopedia)Deep Sea Drilling Project, U.S. program designed to investigate the evolution of ocean basins by core drilling of ocean sediments and underlying oceanic crust. Funded by the National Science Foundatio...

aerial and satellite photography

(Encyclopedia)aerial and satellite photography, technology and science of taking still or moving-picture photographs from a camera mounted on a balloon, airplane, satellite, rocket, or spacecraft. In the 19th cent....