An Etymological Dictionary of Astronomy and Astrophysics
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فرهنگ ریشه شناختی اخترشناسی-اخترفیزیک

M. Heydari-Malayeri    -    Paris Observatory

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Number of Results: 5 Search : condensation
Bose-Einstein condensation (BEC)
  چگالش ِ بوز-اینشتین   
cagâleš-e Bose-Einstein

Fr.: condensation de Bose-Einstein   

A → quantum phase transition during which the → bosons constituting a sufficiently cooled boson gas are all clustered in the → ground energy state. The phase transition results in a → Bose-Einstein condensate. This phenomenon occurs when the temperature becomes smaller than a critical value given by: Tc = (2πħ2 / km)(n / 2.612)2/3, where m is mass of each boson, ħ is the → reduced Planck's constant, k is → Boltzmann's constant, and n is the particle number density. When T  ≤  Tc, the → de Broglie wavelength of bosons becomes comparable to the distance between bosons.

boson; → Einstein; → condensation.

condensation
  چگالش   
cagâleš (#)

Fr.: condensation   

1) General: The act of making more dense or compact.
2) Physics: The physical process by which a vapor becomes a liquid; the opposite of → evaporation. → sublimation; → deposition.
3) Acoustics: The ratio of the instantaneous excess of density to the normal density at a point in a medium transmitting longitudinal sound waves. → rarefaction.
4) Chemistry: Chemical change in which two or more molecules react with the elimination of water or of some other simple substance.
5) Meteorology: Any process by which water vapor changes to dew, fog, or cloud.

Verbal noun from → condense; → -tion.

condensation nucleus
  هسته‌ی ِ چگالش   
haste-ye cagâleš

Fr.: noyau de condensation   

A tiny suspended particle in the → atmosphere around which → water vapor condenses to form → droplets. Condensation nuclei are usually less than about 0.001 mm in diameter and can be made of → ice, → salt, → dust, and other materials. The droplets that form can be liquid water or ice, depending on the surrounding temperature. When the number of these droplets is large enough, a cloud is visible.

condensation; → nucleus.

condensation of vapor
  چگالش ِ بخار   
cagâleš-e boxâr (#)

Fr.: condensation de vapeur   

Change of vapor into liquid. It takes place when the pressure of the vapor becomes equal to the maximum vapor pressure of the liquid at that temperature.

condensation; → vapor.

coronal condensation
  چگالش ِ تاجی   
cagâleš-e tâji

Fr.: condensation coronale   

A part of the → solar corona where the gas density and the temperature are higher than in its vicinity. The coronal condensations are visible on the solar limb, above → sunspot groups. Images in X-rays and those supplied by → coronagraphs in white light reveal that such condensations consist of structures in the form of nodes, underlining the corona magnetic field (M.S.: SDE).

coronal; → condensation.