Big Chemical Encyclopedia

Chemical substances, components, reactions, process design ...

Articles Figures Tables About

Boltzmann constant thermodynamic model

The idea of a thermodynamic temperature scale was first proposed in 1854 by the Scottish physicist William Thomson, Lord Kelvin [iv]. He realized that temperature could be defined independently of the physical properties of any specific substance. Thus, for a substance at thermal equilibrium (which can always be modeled as a system of harmonic oscillators) the thermodynamic temperature could be defined as the average energy per harmonic oscillator divided by the Boltzmann constant. Today, the unit of thermodynamic temperature is called kelvin (K), and is defined as the fraction 1/273.16 of the thermodynamic temperature of the triple point of water. [Pg.671]

The temperature-dependence of the viscosity of simple liquids can be discussed using the cell model as follows. Consider the cell of molecules shown in Fig. 6.2(a), where U is the average height of the potential barrier a molecule must surmount to escape from the cell. The molecule at A tries to climb over this barrier times per second, where Vq is its vibration frequency. The probabihty that the molecule at A acquires sufficient energy, as a result of a thermal fluctuation, to climb over the potential barrier is proportional to the Boltzmann factor exp (—where k is the Boltzmann constant and T is the thermodynamic temperature. Therefore, the number of successful attempts per second to surmount the potential hill, known as the jump frequency i, is ... [Pg.156]

Thermodynamic equation of state Boltzmann constant Affine deformation Gaussian distribution Phantom chain approximation Phantom model Constrained fluctuation model Slip-link model Nonaffine slip tube model Mooney-Rivlin equation Visoelasticity of elastomers Alpha transition Beta transition Gamma transition Storage modulus... [Pg.409]

Since electrostatic effects dominate the thermodynamic cycle as shown in Figure 10-2, major development efforts have focused on the calculation of electrostatic energy for transferring the neutral and charged forms of the ionizable group from water with dielectric constant of about 80 to the protein with a low dielectric constant (see later discussions). This led to the development of continuum based models, where water and protein are described as uniform dielectric media, and enter into the linearized Poisson-Boltzmann (PB) electrostatic equation,... [Pg.265]

In thermodynamics the entropy is defined only for states of equilibrium. Indeed, Boltzmann by actually computing the H-function has shown for a very general class of gas models ([6, Chap. VI 10, Chap. V], also Qtutheorie, I, 139) that this function, is the same, apart from an additive constant, as the negative entropy if we consider states of equilibrium. For states of nonequilibrium, —If is a generalization of the thermodynamical entropy. For the combinatorial meaning of the quantity H, see Section 12d. [Pg.84]


See other pages where Boltzmann constant thermodynamic model is mentioned: [Pg.498]    [Pg.232]    [Pg.723]    [Pg.602]    [Pg.233]    [Pg.247]    [Pg.518]    [Pg.176]    [Pg.285]    [Pg.471]    [Pg.74]    [Pg.62]    [Pg.188]    [Pg.385]    [Pg.249]    [Pg.74]    [Pg.60]    [Pg.268]    [Pg.117]    [Pg.1490]    [Pg.35]    [Pg.456]    [Pg.133]    [Pg.148]    [Pg.20]    [Pg.195]    [Pg.254]    [Pg.350]   
See also in sourсe #XX -- [ Pg.80 , Pg.81 ]




SEARCH



Boltzmann constant

Boltzmann constant model

Boltzmann model

Thermodynamic constants

Thermodynamic model

Thermodynamic modelings

Thermodynamics constants

Thermodynamics modeling

© 2024 chempedia.info