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Chemical potential continuous

The only conclusion needed at this point is a cautious one for a component in a sample in true equilibrium, a chemical potential can certainly be defined, and it seems that in certain circumstances, even where we know that the material is not in its ultimate equilibrium state, the idea of a component having a chemical potential continues to be acceptable and perhaps for some purposes useful. [Pg.21]

The gradient of the chemical potential continues to drive the reaction... [Pg.560]

For both first-order and continuous phase transitions, finite size shifts the transition and rounds it in some way. The shift for first-order transitions arises, crudely, because the chemical potential, like most other properties, has a finite-size correction p(A)-p(oo) C (l/A). An approximate expression for this was derived by Siepmann et al [134]. Therefore, the line of intersection of two chemical potential surfaces Pj(T,P) and pjj T,P) will shift, in general, by an amount 0 IN). The rounding is expected because the partition fiinction only has singularities (and hence produces discontinuous or divergent properties) in tlie limit i—>oo otherwise, it is analytic, so for finite Vthe discontinuities must be smoothed out in some way. The shift for continuous transitions arises because the transition happens when L for the finite system, but when i oo m the infinite system. The rounding happens for the same reason as it does for first-order phase transitions whatever the nature of the divergence in thennodynamic properties (described, typically, by critical exponents) it will be limited by the finite size of the system. [Pg.2266]

At the junction of the adsorbed film and the liquid meniscus the chemical potential of the adsorbate must be the resultant of the joint action of the wall and the curvature of the meniscus. As Derjaguin pointed out, the conventional treatment involves the tacit assumption that the curvature falls jumpwise from 2/r to zero at the junction, whereas the change must actually be a continuous one. Derjaguin put forward a corrected Kelvin equation to take this state of affairs into account but it contains a term which is difficult to evaluate numerically, and has aroused little practical interest. [Pg.123]

Several colloidal systems, that are of practical importance, contain spherically symmetric particles the size of which changes continuously. Polydisperse fluid mixtures can be described by a continuous probability density of one or more particle attributes, such as particle size. Thus, they may be viewed as containing an infinite number of components. It has been several decades since the introduction of polydispersity as a model for molecular mixtures [73], but only recently has it received widespread attention [74-82]. Initially, work was concentrated on nearly monodisperse mixtures and the polydispersity was accounted for by the construction of perturbation expansions with a pure, monodispersive, component as the reference fluid [77,80]. Subsequently, Kofke and Glandt [79] have obtained the equation of state using a theory based on the distinction of particular species in a polydispersive mixture, not by their intermolecular potentials but by a specific form of the distribution of their chemical potentials. Quite recently, Lado [81,82] has generalized the usual OZ equation to the case of a polydispersive mixture. Recently, the latter theory has been also extended to the case of polydisperse quenched-annealed mixtures [83,84]. As this approach has not been reviewed previously, we shall consider it in some detail. [Pg.154]

Numerical solution of Eq. (51) was carried out for a nonlocal effective Hamiltonian as well as for the approximated local Hamiltonian obtained by applying a gradient expansion. It was demonstrated that the nonlocal effective Hamiltonian represents quite well the lateral variation of the film density distribution. The results obtained showed also that the film behavior on the inhomogeneous substrate depends crucially on the temperature regime. Note that the film exhibits different wetting temperatures on both parts of the surface. For chemical potential below the bulk coexistence value the film thickness on both parts of the surface tends to appropriate assymptotic values at x cx) and obeys the power law x. Such a behavior of the film thickness is a consequence of van der Waals tails. The above result is valid when both parts of the surface exhibit either continuous (critical) or first-order wetting. [Pg.282]

The continuous CVM can also be applied to an fee alloy. We use the pair approximation of continuous CVM within the NN pair approximation in the fee binary alloys. For the binary system, we use the chemical potential to control the composition as was done in the 2-D case. For convenience, we choose... [Pg.51]

For convenience, the local energy and chemical potential have been written as continuous functions of x, it being understood that... [Pg.345]

In an early work by Mertz and Pettitt, an open system was devised, in which an extended variable, representing the extent of protonation, was used to couple the system to a chemical potential reservoir [67], This method was demonstrated in the simulation of the acid-base reaction of acetic acid with water [67], Recently, PHMD methods based on continuous protonation states have been developed, in which a set of continuous titration coordinates, A, bound between 0 and 1, is propagated simultaneously with the conformational degrees of freedom in explicit or continuum solvent MD simulations. In the acidostat method developed by Borjesson and Hiinenberger for explicit solvent simulations [13], A. is relaxed towards the equilibrium value via a first-order coupling scheme in analogy to Berendsen s thermostat [10]. However, the theoretical basis for the equilibrium condition used in the derivation seems unclear [3], A test using the pKa calculation for several small amines did not yield HH titration behavior [13],... [Pg.270]

Frossard sees absolutely that Germany will win the war.. . . Frossard offers to put his whole industry into the services of Germany to strengthen the chemical potential for the continuance of the war against England.. .. He says Kuhlmann would be prepared to produce all preliminary auxiliary products for I.G. Farben which would be desired from the German side. He, Frossard, wants a confidential collaboration [independent of the Reich]. .. a closer connection by marriage in the dyestuff and chemical field. [Pg.296]

It may happen in a phase transition that s2 — Si = 0 and V2 — V1 =0 which means that the first derivatives of the chemical potentials are continuous across the transition point. This latter type is indiscriminately commonly referred to as second-order transitions. [Pg.500]

The second boundary condition arises from the continuity of chemical potential [44], which implies - under ideally dilute conditions - a fixed ratio, the so-called (Nernst) distribution or partition coefficient, A n, between the concentrations at the adjacent positions of both media ... [Pg.127]

As another example, the functional expression for the energy in terms of p(r) is known only approximately. However exact formulas have been developed that relate the energies of atoms and molecules to the electrostatic potentials at their nuclei [49-52], This has been done as well for the chemical potentials (electronegativities) of atoms [53]. Thus, both the intrinsic significance and the practical applications of the electrostatic potential continue to be active areas of investigation. [Pg.253]

In this way, we can relate duality to quark-hadron continuity. We considered duality, which is already present at zero chemical potential, between the soliton and the vector mesons a fundamental property of the spectrum of QCD which should persists as we increase the quark chemical potential. Should be noted that differently than in [42] we have not subtracted the energy cost to excite a soliton from the Fermi sea. Since we are already considering the Lagrangian written for the excitations near the Fermi surface we would expect not to consider such a corrections. In any event this is of the order //, [42] and hence negligible with respect to Msoiiton. [Pg.156]

R possesses a spherical core of radius a consisting of quark matter with CFL condensate surrounded by a spherical shell of hadronic matter with thickness R — a containing neutron and proton superfluids. The triangular lattice of singly quantized neutron vortices with quantum of circulation irh/jj, forms in response to the rotation. Since the quark vortices carry SttTj/fi quantum of circulation, the three singly quantized neutron vortices connect at the spherical interface with one singly quantized quark vortex so that the baryon chemical potential is continuous across the interface [19]. [Pg.270]

Stoichiometric saturation defines equilibrium between an aqueous solution and homogeneous multi-component solid of fixed composition (10). At stoichiometric saturation the composition of the solid remains fixed even though the mineral is part of a continuous compositional series. Since, in this case, the composition of the solid is invariant, the solid may be treated as a one-component phase and Equation 6 is the only equilibrium criteria applicable. Equations 1 and 2 no longer apply at stoichiometric saturation because, owing to kinetic restrictions, the solid and saturated solution compositions are not free to change in establishing an equivalence of individual component chemical potentials between solid and aqueous solution. The equilibrium constant, K(x), is defined identically for both equilibrium and stoichiometric saturation. [Pg.564]

The membrane and diffusion-media modeling equations apply to the same variables in the same phase in the catalyst layer. The rate of evaporation or condensation, eq 39, relates the water concentration in the gas and liquid phases. For the water content and chemical potential in the membrane, various approaches can be used, as discussed in section 4.2. If liquid water exists, a supersaturated isotherm can be used, or the liquid pressure can be assumed to be either continuous or related through a mass-transfer coefficient. If there is only water vapor, an isotherm is used. To relate the reactant and product concentrations, potentials, and currents in the phases within the catalyst layer, kinetic expressions (eqs 12 and 13) are used along with zero values for the divergence of the total current (eq 27). [Pg.463]


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See also in sourсe #XX -- [ Pg.144 , Pg.145 , Pg.146 , Pg.147 , Pg.189 , Pg.190 ]




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