Bose-Einstein condensation (BEC)
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.
1) General: The act of making more dense or compact.
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
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.
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.