The state of being free or at liberty.
From M.E. fredom, from O.E. freodom, from freo "free; noble, joyful," → free.
Âzâdi "freedom," noun from âzâd, → free.
Fr.: loi de Freeman
A statistical finding about "normal" → spiral galaxies, whereby there is an upper limit on the mean central → surface brightness of disks. This value is constant for different spiral types, amounting to 21.65 ± 0.30 mag arcsec2 in the B band.
Named after K. C. Freeman (1970, Ap.J. 160, 811); → law.
1) yax bastan; 2) rocidan
1) To change from the liquid to the solid state by loss of heat; become hardened into ice.
Freeze, from O.E. freosan "turn to ice," from P.Gmc. *freusanan (cf. O.H.G. friosan, Ger. frieren "to freeze"), from *freus-, from PIE base *preus- "to freeze" also "to burn" (cf. Skt. pruśva- "hoar-frost, ice;" L. pruina "hoar-frost," Skt. pruśta- "burnt;" Albanian prus "burning coals;" L. pruna "a live coal").
1) Yax bastan, from yax "ice" + bastan "to bind, shut; to congeal, coagulate." The first component yax, from Av. aexa- "ice, frost," isav-, isu- "icy, chilly," cf. Sarikoli (Pamir dialect) īš "cold," P.Gmc. *isa- (O.N. iss, O.Fris. is, Du. ijs, Ger. Eis). The second component bastan, from Mid.Pers. bastan/vastan "to bind, shut;" Av./O.Pers. band- "to bind, fetter," banda- "band, tie" (cf. Skt. bandh- "to bind, tie, fasten;" PIE *bhendh- "to bind;" Ger. binden; E. bind). 2) Rocidan, → coagulate.
1) yaxbast; 2) roceš
Fr.: gel, congélation
1) The phase transition of a substance passing from the liquid to the solid state;
the opposite of → fusion. In meteorology, the freezing of water.
Verbal noun from → freeze.
Fr.: point de congélation
1) The temperature at which a liquid of specified composition changes into a solid under
a specified pressure.
Gibbs free energy
kâruž-e âzâd-e Gibbs
Fr.: énergie libre de Gibbs
The total energy needed to create a thermodynamic system minus the energy provided the environment. It is defined by G = U + PV -TS, where U is the → internal energy, T the → absolute temperature, S the → entropy, P the → pressure, and V is the final → volume. Same as the → Gibbs function and → thermodynamic potential.
Helmholtz free energy
kâruž-e âzâd-e Helmholtz
Fr.: énergie libre de Helmholtz
Of a system, the quantity whose decrease gives the maximum amount of external work which is performed when any physical or chemical process is carried out reversibly at constant temperature. It is defined by F = U - TS, where U is the → internal energy, T the → absolute temperature, and S the final → entropy.
mean free path
puyeš-e âzâd-e miyângin (#)
Fr.: libre parcours moyen
The mean distance which a particle moves between two successive collisions with other particles of the medium. Mean free path is inversely proportional to the number of particles per cm3 (n), and the collision → cross section (σ). In the case of a gas with molecules having a diameter of d, the cross section is equal to the area of a circle of radius d, i.e. σ = πd2, and the mean free path is given by: l = 1/(nσ). Taking into account the relative velocity distribution of the colliding molecules, l = 1/(√2 . nσ). For a gas at one atmosphere pressure and room temperature, the average distance between molecules is roughly 3.5 × 10-7 cm, that is some 35 times the diameter of a molecule. Taking the gas density n = 2.4 × 1014 molecules cm-3, and a typical diameter d = 2 × 10-8 cm for a molecule, the mean free path is 3.3 × 10-5 cm. This means that the average distance between collisions is about 95 times the average distance between molecules.
universality of free fall
hargânigi-ye oft-e âzâd
Fr.: universlité de chute libre
Same as → weak equivalence principle.