1) farâz-padâk; 2) farâz-padâkidan
Fr.: 1) rampe, montée; 2) promouvoir, revaloriser
1a) An incline going up in the direction of movement.
The process by which an area of Earth's crust slowly rises either due to increasing upward force applied from below or decreasing downward force (weight) from above.
1) bârgozâštan; 2) bârgozâri (#)
Fr.: 1) mettre en ligne; 2) mise en ligne
bâlâ (#), zabarin (#)
Higher, as in place, position, pitch, or in a scale.
havâsepehr-e zabarin, javv-e ~
Fr.: atmosphère supérieure
The general term applied to the atmosphere above the → troposphere.
Fr.: culmination supérieure
Same as → superior culmination.
tarâz-e bâlâ (#), ~ zabarin (#)
Fr.: niveau supérieur
In atomic physics, an initial energy state in an emission transition.
hadd-e bâlâ (#), ~ zabarin (#)
Fr.: limite supérieure
Of an integral operator, the point at which the integration ends.
Fr.: manteau supérieur
upper mass cut-off
bore-ye bâlâyi-ye jerm, ~ zabarin-e ~
Fr.: coupure aux masses élevées
Same as → upper mass limit.
upper mass limit
hadd-e bâlâyi-ye jerm, ~ zabarin-e ~
Fr.: limite supérieure de masses
The highest mass range admitted in a star formation model. The high mass end of the → initial mass function. The upper mass limit is a critical parameter in understanding → stellar populations, → star formation, and → massive star feedback in galaxies.
gozar-e zabarin (#)
Fr.: passage supérieur
The movement of a celestial body across a celestial meridian's upper branch. Same as → upper culmination.
Fr.: en amont
1) Toward or in the higher part of a stream; against the current.
A → radioactive metallic → chemical element; symbol U. → Atomic number 92; → atomic weight 238.0289; → melting post 1,132 °C; → boiling point 3,818°C; → specific gravity 19.1 at 25 °C. Uranium has 14 known → isotopes of which 238U is the most abundant in nature. This isotope (→ half-life 4.5 billion years) is 138 times more abundant than 235U (half-life 710 million years). The metal was first isolated by the French chemist Eugène-Melchior Peligot in 1841. See also: → uranium oxide, → uranium conversion, → uranium dioxide, → uranium enrichment, → uranium hexafluoride, → uranium-233, → uranium-235, → uranium-238, → plutonium, → fissile isotope, → fertile isotope, → yellowcake.
From the name of the planet → Uranus. The German chemist Martin-Heinrich Klaproth discovered the element in 1789, following the German/English astronomer William Hershel's discovery of the planet in 1781.
Fr.: convesrion de l'uranium
Fr.: dioxyde d'uranium
A black crystalline solid (UO2pitchblende, carnotite, and autunite and is used chiefly as a source of nuclear energy by fission of the radioisotope uranium-235. After the → uranium hexafluoride is enriched, a fuel fabricator converts it into uranium dioxide powder and presses the powder into fuel pellets.
Fr.: enrichissement de l'uranium
The process by which the percentage of → fissile uranium in a sample is increased. Uranium obtained from mining contains several → isotopes of uranium in different compositions, such as U-238 (~99%), U-235 (~0.7%), and U-234 (~0.02%). Among them, U-235 is the only one that is fissile, i.e. can be used in a → nuclear reactor to produce heat (and consequently electricity) in a controlled manner. As such, the concentration of U-235 as a fuel used in a reactor needs to be increased, which is done using several techniques, such as → gaseous diffusion.
Fr.: hexafluorure d'uranium
A white solid compound (UF6) of → uranium and → fluorine obtained by chemical treatment of → yellowcake, forming a vapor at temperatures above 56 °C. It contains both of the naturally occurring → isotopes of uranium U-235 and U-238. The isotopes are separated on the basis of differences in their diffusion properties. UF6 is the process medium for all separation processes for → uranium enrichment. It is essential that fluoride be a pure element and therefore solely the mass differences of U-235 and U-238 determine the separation process.
Fr.: oxyde d'uranium
A chemical compound made up of → uranium and → oxygen. The most common forms of uranium oxide are U3O8 and UO2. Both oxide forms are solids that have low solubility in water and are relatively stable over a wide range of environmental conditions. Triuranium octaoxide (U3O8) is the most stable form of uranium and is the form most commonly found in nature. → Uranium dioxide (UO2) is the form in which uranium is most commonly used as a → nuclear reactor fuel. At ambient temperatures, UO2 will gradually convert to U3O8.