An Etymological Dictionary of Astronomy and Astrophysics

فرهنگ ریشه شناختی اخترشناسی-اخترفیزیک

M. Heydari-Malayeri    -    Paris Observatory



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Number of Results: 36 Search : nuclear
nuclear power
  توان ِ هسته‌ای   
tavân-e haste-yi

Fr.: puissance nucléaire   

Electric or motive power whose primary source is nuclear energy.

nuclear; → power.

nuclear process
  فراروند ِ هسته‌ای   
farâravand-e haste-yi

Fr.: processus nucléaire   

A process in which an → atomic nucleus changes, including → radioactive decay of naturally occurring and man-made → isotopes, → nuclear fission, and → nuclear fusion.

nuclear; → process.

nuclear reaction
  واژیرش ِ هسته‌ای   
vâžireš-e haste-yi

Fr.: réaction nucléaire   

A process in which the energy, composition, or structure of an atomic nucleus changes.

nuclear; → reaction.

nuclear reactor
  واژیرگر ِ هسته‌ای   
vâžirgar-e haste-yi

Fr.: réacteur nucléaire   

A device in which a nuclear fission chain reaction is maintained and controlled for the production of nuclear energy or radioactive isotopes.

nuclear; → reactor.

nuclear spin
  اسپین ِ هسته‌ای   
espin-e haste-yi

Fr.: spin nucléaire   

The total → angular momentum of a → nucleus, represented by symbol I. The nucleus, which is composed of neutrons and protons, acts as if it is a single entity which has intrinsic angular momentum. The nuclear spin depends on the → mass number; if the mass number is odd then the nucleus has half-integer spin like the electron while if the nucleus has even mass number then its spin will be integer spin.

nuclear; → spin.

nuclear statistical equilibrium (NSE)
  ترازمندی ِ آماری ِ هسته‌ای   
tarâzmandi-ye âmâri-ye haste-yi

Fr.: équilibre statistique nucléaire   

In → nucleosynthesis models, the condition in which all nuclear species are in equilibrium under exchange of → protons and → neutrons. Matter in nuclear statistical equilibrium is characterized by a large abundance of iron peak nuclei. In such equilibria abundance of each nuclide can be calculated from repeated application of → Saha equation.

nuclear; → statistical; → equilibrium.

nuclear time scale
  مرپل ِ زمانی ِ هسته‌ای   
marpel-e zamâni-ye haste-yi

Fr.: échelle de temps nucléaire   

The time required for a star to exhaust its hydrogen (H) supply in → nuclear fusion. The nuclear time scale is given by the relation t = E/L, where E is the total nuclear energy that can be generated by a star and L is the stellar → luminosity. Assuming that the end point of fusion is → iron (Fe), the → atomic mass difference between H and Fe is Δm = 0.008 mH. Therefore, the maximum amount of energy a star with a hydrogen mass M can release is Δ M = 0.008 Mc2. The nuclear time scale is then: t = 0.008 c2M/L. However, stars use up only a fraction of their hydrogen supply, because only the inner part of the star is hot enough for fusion. For example, the Sun will spend only about 10% of its hydrogen supply before evolving into a → red giant. In other words, the solar life time on the → main sequence is about 1010 years.

nuclear; → time; → scale.

nuclear transition
  گذرش ِ هسته‌ای   
gozareš-e haste-yi

Fr.: transition   

A change in the → energy level or state of an atomic → nucleus involving a → quantum of energy.

nuclear; → transition.

nuclear transmutation
  تراموتش ِ هسته‌ای   
tarâmuteš-e haste-yi

Fr.: transmutation nucléaire   

The changing of atoms of one element into those of another by suitable nuclear reactions.

nuclear; → transmutation.

nuclear waste
  آخال ِ هسته‌ای   
âxâl-e haste-yi (#)

Fr.: déchets nucléaires   

A particular type of radioactive waste that is produced as part of the nuclear fuel cycle. These include extraction of uranium from ore, concentration of uranium, processing into nuclear fuel, and disposal of byproducts.

nuclear; → waste.

pycnonuclear reaction
  واژیرش ِ چگال‌هسته‌ای   
vâžireš-e cagâl-hasteyi

Fr.: réaction pycnonucléaire   

A nuclear reaction that takes place at high densities and relatively low temperatures. Pycnonuclear reactions are almost temperature independent and occur even at zero temperature. These reactions are extremely slow at densities typical for normal stars but intensify with increasing density. For example, carbon burns into heavier elements at densities over 1010 g cm-3.

Pycnonuclear, from pycno- a combining form meaning "dense, thick," from Gk. pyknos "dense, solid" + → nuclear; → reaction.

Vâžireš, → reaction; cagâl-hasteyi, from cagâl, → dense, + hasteyi, → nuclear.

thermonuclear flash
  درخش ِ گرماهسته‌ای   
deraxš-e garmâhaste-y

Fr.: flash thermonucléaire   

A theoretical interpretation for the → X-ray bursts observed toward → low-mass X-ray binary (LMXB) stars. According to models, X-ray bursts are produced on the surface of → neutron stars as a result of violent thermonuclear processes in a → hydrogen or → helium rich → layer. It is the → nuclear energy released in the → fusion of hydrogen and helium to heavier elements (e.g., Ni, Zn, and Se) in the → accreted matter which heats the upper layers of the neutron star so that X-rays are emitted from the surface (see, e.g., Taam, R.E., 1984, AIP Conf. Proc. 115, 263).

thermonuclear; → flash.

thermonuclear reaction
  واژیرش ِ گرماهسته‌ای   
vâžireš-e garmâhaste-yi (#)

Fr.: réaction thermonucléaire   

A nuclear reaction in which two or more atomic nuclei fuse into a single heavier nucleus by a collision of the interacting particles at extremely high temperatures. Chains of thermonuclear reactions, such as the → proton-proton chain and the → CNO cycle, account for the energy radiated from the Sun and more massive stars.

thermo- + → nuclear; → reaction.

thermonuclear runaway
  واژیرش ِ گرماهسته‌ای ِ لگام گسیخته   
vâžireš-e garmâhaste-yi-e legâm gosixté

Fr.: emballement thermonucléaire   

1) The uncontrolled → fusion of hydrogen into helium.
2) A → thermonuclear reaction process occurring at electron → degenerate conditions in stellar material, such as in → Type Ia supernovae.

thermonuclear; → runaway.

Vâžireš, → reaction; garmâhaste-yi, → thermonuclear; legâm gosixté literally "rampant, unrestrained," from legâm "bridle, rein" + gosixté "broken off, torn away," p.p. of gosixtan "to tear away, to break off."

thermonuclear supernova
  ابر-نو-اختر ِ گرماتوانیک   
abar-now-axtar-e garmâtavânik

Fr.: supernova thermonucléaire   

Same as → type Ia supernova

thermonuclear; → supernova.

weak nuclear force
  نیروی ِ هسته‌ای ِ نزار، ~ ~ کمزور   
niru-ye hasteyi-ye nezâr, ~ ~ kamzur

Fr.: force nucléaire faible   

Same as → weak interaction.

weak; → nuclear; → force.

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