Fr.: objet rétrograde
An object which has a retrograde orbit around its primary.
Fr.: orbite rétrograde
An orbit with an inclination between 90° and 270° such as those of some comets and small asteroids orbiting the Sun.
Fr.: triangle de Reuleaux
A shape of constant width created using an equilateral triangle and three similar circles. The equilateral triangle lies in the first circle with a vertex coinciding with the center of the circle and the sides equal to the circle radius. The centers of the two other circles are located at the two other vertices. The Reuleaux triangle is the intersection of the three circles.
Named after Franz Reuleaux (1829-1905), a German engineer, specialist of analysis and design of mechines; → triangle.
Fr.: inversion, interversion
An act or instance of reversing. The state of being reversed. → phase reversal.
vârun, vâgard (#)
Fr.: contraire, opposé
Opposite or contrary in position, direction, order, etc.
M.E. revers from O.Fr. revers "reverse, cross," from L. reversus, p.p. of revertere "to turn back," from → re- "back" + vertere "to turn," cognate with Pers. gard "to turn," as below.
Vârun "inverse, upside down," from vâ- "back, backward, again, re-,"
variant of bâz-, from Mid.Pers. abâz-, apâc-, O.Pers. apa- [pref.]
"away, from;" Av. apa- [pref.] "away, from,"
apaš [adv.] "toward the back;" cf. Skt. ápāñc
Fr.: choc en retour
A → shock front in a → supernova remnant (SNR) arising from the interaction of the → supersonic → forward shock wave with the → interstellar medium (ISM) material. The reverse shock forms as the high pressure gas behind the forward shock wave expands and pushes back on the stellar ejecta. Reverse shock propagates into ejecta, starting from outside.
Capable of returning to an original condition. → reversible process.
farâravand-e vâgaštpazir (#)
Fr.: processus réversible
Any physical process which can be performed in the reverse direction, the whole series of changes constituting the process being exactly reversed. → irreversible process.
lâye-ye vâgardân (#)
Fr.: couche d'inversion
A layer of relatively cool gas forming the lower part of the Sun's chromosphere, just above the photosphere, that gives rise to absorption lines in the Sun's spectrum.
1) bâzdâ; 2) bâzdâ kardan
Fr.: 1) revue; 2) faire une revue
1a) A critical article or report.
M.E., from O.Fr. reveue "a reviewing, review," from feminine p.p. of revoir "to see again, reexamine," from O.Fr. reveoir, from → re- + veoir, veeir "to see."
Bâzdâ, from bâz-, → re-, + dâ root of didan "to see" (Mid.Pers. ditan "to see, regard, catch sight of, contemplate, experience;" O.Pers. dī- "to see;" Av. dā(y)- "to see," didāti "sees;" cf. Skt. dhī- "to perceive, think, ponder; thought, reflection, meditation," dādhye; Gk. dedorka "have seen") + kardan "to do," → -or.
Fr.: papier de revue
A talk that deals with a subject by examining, criticizing, and summarizing the facts.
To alter something already written or printed, in order to make corrections, improve, or update (Dictionary.com).
the act or work of revising. a process of revising. a revised form or version, as of a book.
Verbal noun of → revise.
Fr.: reprise, remise en vigueur, renouveau
1) An improvement in the condition, strength, or fortunes of someone or something.
1) bâz-zividan; 2) bâz-zivândan
Fr.: ranimer, réanimer, faire renaître
1a) Regain life, consciousness, or strength.
The act of revoking; annulment.
Verbal noun of → revoke.
1) To take back or withdraw; annul, cancel, or reverse; rescind or repeal.
The movement of a celestial body which is in orbit around another. It is often measured as the → orbital period.
Verbal noun of → revolve.
To move in a an orbit around another object. Compare with → rotate.
M.E. revolven, from L. revolvere "to turn, roll back," from → re- "back, again" + volvere "to roll."
Gardidan variant gaštan "to turn, to change;" gardun "wheel; chariot;" (+ → ni-) navardidan, navard- "to twist; to fold; to stroll;" Mid.Pers. wardidan, walt- "to turn; twist;" Av. varət- "to turn, revolve;" cf. Skt. vart- "to turn, roll," vartate "it turns round, rolls;" L. vertere "to turn;" O.H.G. werden "to become;" PIE base *wert- "to turn, bend."
adad-e Reynolds (#)
Fr.: nombre de Reynolds
A dimensionless quantity that governs the conditions for hydrodynamic stability and the occurrence of turbulence in fluids. It is defined by the ratio, R, of the inertial force (ρ u2) and the viscous force (μ u / L), i.e. R = L u ρ/μ, where L is a typical dimension of the system, u is a measure of the velocities that prevail, ρ the density, and μ the kinematic viscosity. At low Reynolds numbers the flow is steady, since the viscous forces are predominant in controlling the flow. At a critical value of R, corresponding to a critical velocity, the flow becomes turbulent.
Named after Osborne Reynolds (1842-1912), a British physicist who pioneered the study of turbulent flows; → number.