An Etymological Dictionary of Astronomy and AstrophysicsEnglish-French-Persian

فرهنگ ریشه شناختی اخترشناسی-اخترفیزیک

M. Heydari-Malayeri    -    Paris Observatory

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Number of Results: 1310
 Couette viscometer   وشک‌سنج ِ کویءت   vošksanj-e CouetteFr.: viscosimètre de Couette   A device consisting of two vertical coaxial cylinders and a fluid filling the volume between the cylinders and used for measuring the viscosity of the fluid. The inner cylinder is stationary while the outer cylinder rotates. The amount of shear stress produced owing to rotation is directly proportional to the viscosity of the fluid. Couette-Taylor flow   تچان ِ کویءت-تیلر   tacân-e Couette-TaylorFr.: écoulement de Couette-Taylor   In fluid mechanics, the motion of a fluid between two concentric cylinders when one or both of the cylinders rotate.→ Couette flow; Geoffrey Ingram Taylor (1886-1975), British physicist; → flow. coulomb (C)   کولن   coulomb (#)Fr.: coulomb   The unit of → electric charge in the → mks system, equal to the quantity of charge transferred in one second by a steady current of one → ampere. One coulomb represents a charge of approximately 6.241 506 × 1018 → electrons. Compared with the charge unit in the → cgs system, 1 C = 2.998 × 109 → esu.Named after the French physicist Charles Augustin de Coulomb (1736-1806), who pioneered research into magnetism and electricity. Coulomb barrier   ورغه‌ی ِ کولن   varqe-ye Coulomb (#)Fr.: barrière de Coulomb   The energy barrier due to electrostatic interaction that two nuclei (for example two protons) need to overcome so they can get close enough to undergo nuclear fusion (to form a helium).→ coulomb; → barrier. Coulomb collision   همکوبش ِ کولن   hamkubeš-e CoulombFr.: collision coulombienne   A particle → collision where the dominant force is described by → Coulomb's law. The collision results in deflections of the particles away from their initial paths.→ coulomb; → collision. Coulomb energy   کاروژ ِ کولن   kâruž-e CoulombFr.: énergie coulombienne   The → potential energy from which derives the repulsive electrostatic force between two → charged particles. For example, the Coulomb energy between two protons is e2/r ~ 0.5 MeV, which is small compared with the average → binding energy per particle (~ 8 Mev). However the Coulomb repulsion becomes important for heavy nuclei. The total Coulomb energy of a nucleus is given by: (3/5) Z(Z - 1)e2/R, where Z is the → atomic number, e the charge, and R the nuclear radius. Since R ∝ A1/3 and Z is roughly proportional to A, the Coulomb energy is roughly proportional to A5/3. On the other hand, the total binding energy is proportional to A, which means that the relative importance of the repulsive electrostatic energy increases with increasing mass number as A2/3.→ coulomb; → energy. Coulomb excitation   بر‌انگیزش ِ کولن   barangizeš-e CoulombFr.: excitation coulombienne   The transition to a higher → energy level than → ground state undergone by an atomic nucleus when a → charged particle of appropriate energy moves past it.→ coulomb; → excitation. Coulomb force   نیروی ِ کولن   niru-ye Coulomb (#)Fr.: force de Coulomb   An attractive or repulsive → electrostatic force between objects bearing electric charge, as described by → Coulomb's law. If the charges are of opposite sign, then the force is attractive; if thy are of the same sign, the force is repulsive.→ Coulomb; → force. Coulomb gauge   گز ِ کولن   gaz-e CoulombFr.: jauge de Coulomb   The optimum → gauge for steady fields, defined by: ∇.A = 0, where A is the → magnetic vector potential. Also called transverse gauge.→ Coulomb; → gauge. Coulomb interaction   اندرژیرش ِ کولن   andaržireš-e CoulombFr.: interaction de Coulomb   The reciprocal force between two or more → charged particles according to → Coulomb's law.→ coulomb; → interaction. Coulomb pressure   فشار ِ کولن   fešâr-e CoulombFr.: pression de Coulomb   The repulsive interaction due to the → Coulomb energy between two ions. If the ionic charge is Z, then the Coulomb potential energy is Z2e2/a, where a is some typical separation between the ions. The Coulomb pressure is expected to become important when the ratio ΓC = Z2e2/akT is much larger than 1. In that case, Coulomb effects dominate those of → thermal agitation and the gas settles down into a → crystal.→ Coulomb; → pressure. Coulomb's law   قانون ِ کولن   qânun-e Coulomb (#)Fr.: loi de Coulomb   The electrical force between two charged objects is directly proportional to the product of the quantity of charge on the objects and inversely proportional to the square of the separation distance between the two objects→ coulomb; → law. count   ۱) شماردن؛ ۲) شمار   1) šomârdan (#); 2) šomâr (#)Fr.: 1) compter; 2) coup   1) (v.) To enumerate; reckon up; calculate; compute. 2) (n.) A single ionizing event registered by a device such as a → Geiger counter. The indication of the total number of ionizing events registered by a device.From O.Fr. conter "add up," from L. computare, → compute.Šomârdan, from Mid.Pers. ôšmârtan, ôšmurtan "to reckon, calculate, enumerate, account for," from Av. base (š)mar- "to have in mind, remember, recall," pati-šmar- "to recall; to long for," hišmar-, cf. Skt. smar- "to remember, become aware," smarati "he remembers," L. memor, memoria, Gk. mermera "care," merimna "anxious thought, sorrow," martyr "witness." countdown   فروشمارش   forušomârešFr.: compte à rebours   1) The backward counting in fixed time units from the initiation of a project, as a rocket launching, with the moment of firing designated as zero. 2) The final preparations made during this period (Dictionary.com).→ count; → down. counter   شمارگر   šomârgar (#)Fr.: compteur   Generally,a device for indicating a number or amount. Any of various instruments for detecting ionizing radiation and for registering counts. → Geiger counter.M.E. countour, from O.Fr. conteor, from L. computator, from computa(re) "to compute" + → -tor suffix forming personal agent nouns mainly from verbs.Šomârgar, from šomâr present tense stem of šomârdan "to count," → count + agent suffix -gar. counter-   پاد-   pâd- (#)Fr.: contre-   A prefix used with the meanings "against, contrary, opposite." → contra-.M.E. countre-, from O.Fr. contre-, from L. contra "opposite, against;" PIE base *kom- "beside, near, by, with."Pâd- "contrary to; against; opposing," variants pâ- (pâsox, pâzahr, pâhang, → response), paž- (pažvâk, → echo, pažâvand "the bar of a door or a gate, door lock"), baž- (bažkam, → forbidden), pat- (patvâz, → correspond), pa- (panâh, padid), from Mid.Pers. pât-, from O.Pers. paity "agaist, back, opposite to, toward, face to face, in front of," Av. paiti, akin to Skt. práti "toward, against, again, back, in return, opposite," Pali pati-, Gk. proti, pros "face to face with, toward, in addition to, near;" PIE *proti. counterbalance   پاتراز   pâtarâzFr.: contrebalance   An equal weight, power, or influence acting in opposition.→ counter-; → balance. counterclockwise   پادساعت‌سو   pâdsâ'atsu (#)Fr.: en sens inverse des aiguilles d'une montre   In a direction opposite to the rotating hands of a clock.From counter- "contrary; opposite; opposing," + → clockwise.Pâdsâ'atsu, from pâd-, → counter-, + sâ'atsu, → clockwise. counterexample   پادنمونه   pâdnemunéFr.: contre-exemple   Logic: An individual case or instance that falsifies a universal generalization. A counterexample to an → argument is a situation in which the → premises are → true, but the → conclusion is → false. For example, "All dogs are mammals" (true). "All cats are mammals" (true). "Therefore, all cats are dogs." (false).→ counter-; → example. counterflow   پادتچان   pâdtacânFr.: contreflot   The movement of a fluid in the opposite direction to a fluid flowing in the same cross section of a turbulent medium.→ counter-; → flow.