An Etymological Dictionary of Astronomy and Astrophysics

فرهنگ ریشه شناختی اخترشناسی-اخترفیزیک

M. Heydari-Malayeri    -    Paris Observatory



Number of Results: 15 Search : thermodynamic
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: δQ = δU + δW, where δQ is the heat transferred to the system, δU the change in internal energy (resulting in a rise or fall of temperature), and δW 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 → microstates 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.


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 → ionizations of helium per second as there are → recombinations 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 → states 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 states 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 systems, → closed systems, and → isomated systems.

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.


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.