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The General Theoretical Framework

We start with the analogue of the model discussed in Sections 4.7 and 5.6. The system consists of four identical subunits, each having one binding site. Each subunit can be in one of two conformational states, L or //, having different [Pg.193]

Q H) is the canonical PF of a system having i bound ligands. Each of these may be written as a sum over all possible conformations of the subunits. Since each of the indices a, p, y, 8 can be either L or H, we have altogether sixteen terms in the sum over these indices. The explicit form of each of the factors depends [Pg.194]

Note that direct correlation factors S are included in 2 (0 ( 2) and are assumed to be additive. [Pg.196]

As an example, we construct 2(3) for the linear model. The common factor is [which has one 2 (a=L,H) for each subunit in state a, and one for each subunit-subunit interaction]. This is multiplied by the variable factor + 2g p 8S] and then summed over all the indices aPy8. (Note [Pg.196]

The four terms in square brackets correspond to the four configurations of placing three ligands at the four sites. In two of these there is only one direct correlation S, and in the other two there are two factors of direct correlation. [Pg.196]

Ordinarily, in quantum chemistry we concern ourselves with the solution of the Schrodinger equation [Pg.227]

For the metastable states in which the decaying electron spends some time in the vicinity of the target, Gamow /52/ and Dirac /53/ suggested that the width of these resonances T is related to the lifetime by the uncertainty relation T = h/r where r is the lifetime of the metastable state and that the time development of these decaying states be described by [Pg.227]

However, the Siegert function of eqn. (10) is divergent / V rei ad r oo and the number of particles is not conserved. This non-L2 nature of ipTet has given rise to difficulties in the direct application of Siegert s method to resonant scattering /55/. [Pg.227]

In order to conserve the number of particles and to be able to apply the usual bound state methods to the treatment of resonances, the following transformations are called for /56/  [Pg.228]

The theorems of Aguilar, Balslev and Combes /27-30/ prescribe that the complex scaling of all the electronic coordinates in the Hamiltonian modifies its spectrum as depicted in fig. 1. [Pg.228]

In this section, we present a general outline of a theoretical approach to water and point out some basic assumptions that are made in most theories. [Pg.100]

The most fundamental starting point for any theoretical approach is the quantum mechanical partition function PF), and the fundamental connection between the partition function and the corresponding thermodynamic potential. Once we have a PF, either exact or approximate, we can derive all the thermodynamic quantities by using standard relationships. Statistical mechanics is a general and very powerful tool to connect between microscopic properties of atoms and molecules, such as mass, dipole moment, polarizability, and intermolecular interaction energy, on the one hand, and macroscopic properties of the bulk matter, such as the energy, entropy, heat capacity, and compressibility, on the other. [Pg.101]

The general quantum mechanical partition function of the system is  [Pg.101]

However, since the canonical PF requires the knowledge of all energy levels of a system, and this is impossible to calculate at present (except for highly simplified models), we resort to the classical analog of the canonical partition function Qclass 111 making this transition from the quantum mechanical to the classical PF, we actually make a few assumptions and approximations. [Pg.101]

The classical limit for the translational degrees of freedom is attained when c 1, where p is the number density and is the momentum PF, or the de Broglie thermal wavelength. This [Pg.101]


Despite the fact that electron transfer reactions at the electrode/electrolyte interface are of fundamental importance to many chemical processes, a quantitative understanding of the factors that influence the rate of these reactions is still lacking. Although the general theoretical framework was established many years ago by Marcus, Levich, Dogonadze, and oth-... [Pg.154]

The Ti q) behave as wavevector-dependent relaxation times and the form of the wavevector dependence can provide a useful check on the consistency of models. Table 5 shows a comparison of the experimental coefficients for fresh apple tissue with those calculated with the numerical cell model. The agreement is quite reasonable and supports the general theoretical framework. It would be interesting to apply this approach to mealy apple and to other types of fruit and vegetable. [Pg.108]

The most favourable circumstances for observing the competitive effect are probably those of reactions within the radiation chemical spur, where high concentrations of both reactants are formed [see Chap. 7, Sect. 4]. Little work, except that of Clifford et al. [442, 443], has been done on such systems to incorporate competitive effects. In this section, some of the work which has been done is considered and the general theoretical framework advanced. [Pg.289]

In this chapter we first review the general theoretical framework of VER, including a discussion of various different quantum correction factors. We then consider three specific systems, extending and developing the basic framework as needed, and in each case then make detailed comparison with experiment. [Pg.684]

The use of more sophisticated calculations based on rotational isomeric state theory [9,10] allows calculation of CM(T), but this capability still does not enable us to predict Tg accurately since CJTg) cannot be calculated without having some idea of what Tg should be before the calculation. Despite this limitation, Equation 6.18 and the general theoretical framework which led to its development hold out the hope that further extensions of this approach or similar methods may be able to allow accurate predictions of the effects of tacticity on Tg in the future. [Pg.268]

Regarding the analytical model further comments may apply. The general theoretical framework stands as the DFT however, this venture was developed on its conceptual rather than on its computational virtues. This way, the approximate energetic functional approaches (Nalewajski, 1996 Putz, 2008b) were systematically avoided by considering the independent-particle picture ofthe softness kernel formulation, see Sections 4.6.1-4.6.4. [Pg.262]

In Sec. 2.2,1 will present the general theoretical framework for the study of water where the difficulties and the approximations of any theoretical approach will be discussed. [Pg.99]

The variable Q is intrinsically random. For quantifying the imcertainty of Q, a sample of 149 atmual maximal value is available. The extreme value theory gives the general theoretical framework for properly fitting a probability distrihution to the maxima of iid... [Pg.1704]

While no one presently doubts that quantum mechanics forms the general theoretical framework for the discussion of molecular processes, the question of what is the most convenient computational algorithm for certain classes of problems is open. [Pg.69]

The experimental data mentioned in this section and in more detail in other reviews, substantiates the general theoretical framework for protein folding and function given by the single funnel hypothesis. However, in spite of all the studies, theoretical and experimental, that seem to support it, there is not, as yet, a definitive proof for the single funnel hypothesis and in the next sections an alternative theoretical framework, based on a kinetic control of folding, will be put forward. [Pg.92]

In Chapter 2, we discuss the refractive indices of hquid ciystals in terms of the induced polarization P and the optical electric field E, where P is linearly related to E. Generally speaking, a material is said to be optically nonlinear when the induced polarization Pis not linearly dependent on E. This could happen if the optical field is very intense. It could also happen if the physical properties of the material are easily perturbed by the optical field. In this chapter we describe the general theoretical framework for studying these processes. Specific nonlinear optical phenomena observed in liquid crystalline systems will be presented in Chapter 12. [Pg.273]

Separation of the effects due to the long-range and short-range interactions greatly advances the understanding of the dynamics prevailing in continuum processes. Particularly useful general theoretical frameworks to this effect have been the R-matrix theory [44, 70] and the multichannel quantum defect theory (MQDT) [71, 72], They have been applied successfully to a wide variety of atomic and molecular systems, and the relevant material is too rich to be covered in this article. [Pg.205]

Stochastic models for biochemical reaction systems in terms of the CME are not an alternative to the differential equation approach, but a more general theoretical framework that deserves further investigation. In particular, the relation between the dynamic CME and the general theory of statistical thermodynamics of closed and... [Pg.280]

Because of the importance of boundary-layer theory to problems related to flame attachment and to flame spread, we shall begin with a presentation of this subject as applied to reacting flows. It will be seen that formulations base(f on coupling functions (Section 1.3) are particularly useful for reacting boundary layers. A general theoretical framework will be... [Pg.485]

Methodology. Unquestionably, the application of quantum mechanics to chemical bonding has revolutionized scientific thinking. In fact, the modern theoretical framework of chemistry rests on quantum physics. In principle, the Schrodinger equation may be solved for any chemical system. No prior knowledge of any analogous or related system is necessary. Exactly solvable problems are rare, due to the mathematical complexities recourse must then be made to approximate methods, and many powerful approaches have been devised. Generally, approximate solutions must suffice for the size of molecules of pharmaceutical interest. [Pg.718]

In actual long term applications of polymers, however, it is well known that chemical reactions occur which actually change the viscoelastic properties of the material while it is in use. In addition, environmental factors such as exposure to solvents or even water, while not always chemically modifying a material, can have a profound influence on its viscoelastic properties in much the same way as a true chemical transformation. If predictions based exclusively on time-temperature correspondence were to be successful, the rates of all of these processes would have to vary with temperature in exactly the same m inner as does the viscoelastic spectrum. While this might be approximately true in certain special cases, it is usually not so. Thus, a more general theoretical framework is necessary to predict the properties of simultaneously chemically reacting and physically relaxing networks. [Pg.219]

This book provides a consistent treatment of these issues that is based on a general theoretical framework. This, in turn, stems from the generalized population-balance equation (GPBE), which includes as special cases all the other governing equations previously mentioned (e.g. PBE and BE). After discussing how this equation originates, the different computational models for its numerical solution are presented. The book is structured as follows. [Pg.524]


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