expansion by compression
41Variable star — A star is classified as variable if its apparent brightness as seen from Earth changes over time, whether the changes are due to variations in the star s actual luminosity, or to variations in the amount of the star s light that is blocked from… …
42Acousto-optic modulator — An acousto optic modulator (AOM), also called a Bragg cell, uses the acousto optic effect to diffract and shift the frequency of light using sound waves (usually at radio frequency). They are used in lasers for Q switching, telecommunications for …
43Perforce — is a commercial, proprietary revision control system developed by Perforce Software, Inc.ArchitecturePerforce is a client/server system.The server manages a central database and a master repository of file versions. Users work on files in local… …
44Theory of heat — In the history of science, the theory of heat or mechanical theory of heat was a theory, introduced predominantly in 1824 by the French physicist Sadi Carnot, that heat and mechanical work are equivalent.[1] It is related to the mechanical… …
45Carnot, Sadi — ▪ French engineer and physicist in full Nicolas léonard sadi Carnot born June 1, 1796, Paris, Fr. died Aug. 24, 1832, Paris French scientist who described the Carnot cycle, relating to the theory of heat engines. Carnot was the… …
46Emden, Robert — ▪ Swiss astronomer born March 4, 1862, St. Gallen, Switz. died Oct. 8, 1940, Zürich physicist and astrophysicist who developed a theory of expansion and compression of gas spheres and applied it to stellar structure. In 1889 Emden was …
47absolute humidity — noun a) The mass of water vapour in a given volume of air b) In a system of moist air, the ratio of the mass of water vapor present to the volume occupied by the mixture, that is, the density of the …
48Carnot cycle — noun a cycle (of expansion and compression) of an idealized reversible heat engine that does work without loss of heat • Syn: ↑Carnot s ideal cycle • Hypernyms: ↑cycle, ↑oscillation * * * Thermodynam. an ideal cycle of reversible engine… …
49Carnot's ideal cycle — noun a cycle (of expansion and compression) of an idealized reversible heat engine that does work without loss of heat • Syn: ↑Carnot cycle • Hypernyms: ↑cycle, ↑oscillation …
50adiabatic gradient — noun : the rate at which the temperature of an ascending or descending body of air is changed by adiabatic expansion or compression, being about 1.6° F. for each 300 feet of change of height; also : a curve representing this * * * adiabatic… …
