first law of thermodynamics قانون ِ نخست ِ گرماتوانیک qânun-e naxost-e garâtavânik
*Fr.: première loi de la thermodynamique*
The total energy of a → *closed system*
is constant. This means that energy can be changed from one form to another,
or transferred from one system to another, but it cannot be created or destroyed.
A mathematical formulation of the first law is:
δ*Q* = δ*U* + δ*W*,
where δ*Q* is the heat transferred to the system, δ*U*
the change in internal energy (resulting in a rise or fall of temperature), and
δ*W* is the work done by the system. → *first*; → *law*;
→ *thermodynamics*. |

local thermodynamic equilibrium (LTE) ترازمندی ِ گرماتوانیک ِ محلی tarâzmandi-ye garmâtavânik-e mahali
*Fr.: équilibre thermodynamique local*
The assumption that all distribution functions characterizing the
material and its interaction with the radiation field at a point in
the star are given by → *thermodynamic equilibrium* relations at local
values of the temperature and density. → *local*; → *thermodynamic*;
→ *equilibrium*. |

non-local thermodynamic equilibrium (NLTE) ترازمندی ِ گرماتوانیک ِ نامحلی tarâzmandi-ye garmâtavânik-e nâmahali
*Fr.: hors équilibre thermodynamique local*
A physical condition in which the assumption of the
→ *local thermodynamic equilibrium* does not hold. → *non-*; → *local thermodynamic equilibrium*. |

second law of thermodynamics قانون ِ دوم ِ گرماتوانیک qânun-e dovom-e garmâtavânik
*Fr.: deuxième loi de la thermodynamique*
1) Heat cannot be transferred from a colder to a hotter body without some other effect, i.e.
without → *work* being done. Expressed in terms of
→ *entropy*: the entropy of an
→ *isolated system* tends toward a maximum and its
available energy tends toward a minimum.
2) In language of → *statistical physics*,
an isolated physical system will tend toward an
equilibrium → *macrostate*
with as large a total → *entropy*
as possible, because then the number of → *microstate*s
is the largest. See also
→ *Kelvin's postulate*,
→ *Clausius's postulate*. → *second*; → *law*;
→ *thermodynamics*. |

statistical thermodynamics گرماتوانیک ِ آماری garmâtavânik-e âmâri
*Fr.: thermodynamique statistique*
Same as → *statistical mechanics*. → *statistical*; → *thermodynamics*. |

thermodynamic گرماتوانیک garmâtavânik
*Fr.: thermodynamique*
Of or pertaining to → *thermodynamics*. → *thermo-*; → *dynamic*. |

thermodynamic equilibrium ترازمندی ِ گرماتوانیک tarâzmandi-ye garmâtavânik
*Fr.: équilibre thermodynamique*
The condition of a → *thermodynamic system*
in which the available → *energy* is distributed uniformly
among all the possible forms of energy. Furthermore,
all → *thermodynamic process* es must be exactly balanced by
their reverse processes. For example, inside a star
there will be as many → *ionization*s of helium per second
as there are → *recombination*s of
free electrons and helium ions. Se also
→ *local thermodynamic equilibrium (LTE)*. → *thermodynamic*; → *equilibrium*. |

thermodynamic path په ِ گرماتوانیک pah-e garmâtavânik
*Fr.: chemin thermodynamique*
The loci of various changes between two → *state*s through which a
→ *thermodynamic system* passes during a
→ *thermodynamic process*. → *thermodynamic*; → *path*. |

thermodynamic potential توند ِ گرماتوانیک tavand-e garmâtavânik
*Fr.: potentiel thermodynaique*
A measure of the energy level of a → *thermodynamic system*.
It represents the amount of → *work* obtainable when the system
undergoes a → *change*. The main types of thermodynamic
potential are:
→ *internal energy*,
→ *enthalpy*, the
→ *Helmholtz free energy*, and the
→ *Gibbs free energy*. → *thermodynamic*; → *potential*. |

thermodynamic process فراروند ِ گرماتوانیک farâravand-e garmâtavânik
*Fr.: processus thermodynamique*
An ordered set of → *equilibrium state*s undergone by a
→ *thermodynamic system*. Thermodynamics processes have
various types:
→ *cyclic process*, → *reversible process*,
and → *irreversible process*,
→ *isothermal process*, → *adiabatic process*,
→ *isentropic process*. → *thermodynamic*; → *process*. |

thermodynamic system راژمان ِ گرماتوانیک râžmân-e garmâtavânik
*Fr.: système thermodynamique*
A quantity of substance or a working machine which in a well-defined way is set apart from
its → *environment*. The boundary between the system and its
surroundings can be real or an imaginary mathematical envelope. A thermodynamic system
is not necessarily bound to a predefined geometry. Thermodynamic systems can be divided into
three types:
→ *open system*s,
→ *closed system*s, and
→ *isomated system*s. → *thermodynamic*; → *system*. |

thermodynamic temperature دمای ِ گرماتوانیک damâ-ye garmâtavânik
*Fr.: température thermodynamique*
A temperature scale, measured in → *kelvin (K)*,
that is related to the energy possessed by matter; it was formerly known as
→ *absolute temperature*.
The zero point on the scale (0 K) is absolute
zero. Thermodynamic temperature can be converted to temperature on
the → *Celsius scale*
by subtracting 273.15. → *thermodynamic*;
→ *temperature*. |

thermodynamics گرماتوانیک garmâtavânik
*Fr.: thermodynamique*
A branch of physics concerned with the relations between heat and
other forms of energy and how these affect temperature, pressure, volume,
mechanical action, and work. → *thermo-*; → *dynamics*, coined by
the Scottish physicist William Thomson (Lord Kelvin, 1824-1907), in 1849. |

third law of thermodynamics قانون ِ سوم ِ گرماتوانیک qânun-e sevom-e garmâtavânik
*Fr.: troisième loi de la thermodynamique*
The → *entropy* of an idealized state of maximum order is
zero at the temperature of → *absolute zero*.
Another version of this law: As a system approaches absolute zero, all processes
cease and the entropy of the system approaches a minimum value. → *third*; → *law*;
→ *thermodynamics*. |

zeroth law of thermodynamics قانون ِ صفرُم ِ گرماتوانیک qânun-e sefrom-e garmâtavânik
*Fr.: loi zéro de la thermodynamique*
Two objects that are in → *thermal equilibrium*
with a third object will be in thermal equilibrium with each other. → *zero*; → *law*;
→ *thermodynamics*. |