Big Chemical Encyclopedia

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

Articles Figures Tables About

Connection formula applications

The arbitrary-order connection formulas (4.19), (4.21) and (4.22) can in many cases be used for obtaining very accurate solutions of physical problems, when the turning points are well separated, and there are no other transition points near the real axis in the region of the complex 2-plane of interest. Within their range of applicability, these connection formulas are very useful because of their simplicity and the great ease with which they can be used. They have been discussed by Froman and Froman (2002) see Sections 3.10-3.13 and 3.20 there. [Pg.40]

Straub et al. described several systems in detail, concentrating on system parameters where a comparison with one or more analytic rate theories Grote-Hynes,9 etc.) could be made, and in addition where tests of connection formulas that bridge these analytic theories could be performed. While we will discuss their detailed comparisons in a later section, we note here that the power of simulation in understanding the range of applicability of analytic theories is evident in the work of Straub et al. As Straub et al. point out, extending these comparisons to experiment requires the consideration of several quantities (potential of mean force, friction on the reaction coordinate, etc.), which may in fact be difficult to estimate from experimental measurements. There is still a need in many types of reactions to connect the parameters of such models to experimental measurements on real systems. [Pg.87]

The goal is to apply the formulas, the K values, and the pipe and connections friction values to determine the Hf and Hv, plus the Hs and Hp, and then the TDH, total dynamic head in the system. Then we can specify a pump for this application. [Pg.101]

This chapter has provided a brief overview of the application of optimal control theory to the control of molecular processes. It has addressed only the theoretical aspects and approaches to the topic and has not covered the many successful experimental applications [33, 37, 164-183], arising especially from the closed-loop approach of Rabitz [32]. The basic formulae have been presented and carefully derived in Section II and Appendix A, respectively. The theory required for application to photodissociation and unimolecular dissociation processes is also discussed in Section II, while the new equations needed in this connection are derived in Appendix B. An exciting related area of coherent control which has not been treated in this review is that of the control of bimolecular chemical reactions, in which both initial and final states are continuum scattering states [7, 14, 27-29, 184-188]. [Pg.73]

In principle, Gibbs free energies of transfer for trihalides can be obtained from solubilities in water and in nonaqueous or mixed aqueous solutions. However, there are two major obstacles here. The first is the prevalence of hydrates and solvates. This may complicate the calculation of AGtr(LnX3) values, for application of the standard formula connecting AGt, with solubilities requires that the composition of the solid phase be the same in equilibrium with the two solvent media in question. The other major hurdle is that solubilities of the trichlorides, tribromides, and triiodides in water are so high that knowledge of activity coefficients, which indeed are known to be far from unity 4b), is essential (201). These can, indeed, be measured, but such measurements require much time, care, and patience. [Pg.113]

The second-order changes, in terms of which polarizability coefficients may be defined, are much more difficult to discuss because they involve essentially a change in the wave function (made in such a way as to preserve self-consistency)—unlike the first-order changes, which involve the Mwperturbed wave function only. Approximate formulae for the polarizabilities were first obtained (McWeeny, 1956) using a steepest descent method to minimize the energy, a useful result being the establishment of a connection between tt,, and F, valid for systems of any kind (non-alternant or heteroaromatic included) and applicable either in Hiickel theory or in a more complete theory. [Pg.133]

We will describe, in some detail, one such modification, an effective Dirac equation (EDE) which was derived in a number of papers [7, 8, 9, 10]. This new equation is more convenient in many applications than the original BS equation, and we will derive some general formulae connected with this equation. The physical idea behind this approach is that in the case of a loosely bound system of two particles of different masses, the heavy particle spends almost all its life not far from its own mass shell. In such case some kind of Dirac equation for the light particle in an external Coulomb field should be an excellent starting point for the perturbation theory expansion. Then it is convenient to choose the free two-particle propagator in the form of the product of the heavy particle mass shell projector A and the free electron propagator... [Pg.6]

Then, according to the statement below Eq. (106), the absorption cross section below the Ps formation threshold Eth and within the energy range of applicability of the Baz law is derivable from the knowledge of the Ps formation cross section above Elh, in spite of the fact that these two cross sections are conventionally obtained completely independently. The absorption cross section below Eth must smoothly connect to the Ps formation cross section above Elh according to a single known formula (104). [Pg.230]

Once the desired structure is generated the user should be able to use its representation (the connection table) in many different ways to store it, to combine it with other structures, supplement it with textual information, to decompose it to fragments, add it to a collection, use it as a target or query compound in different searches or procedures, use it in different applications such as simulation of spectra, determination of properties, etc. calculate molecular formula, draw it on a plotter, etc. [Pg.69]

Proceeding toward conclusions of higher specificity, notice that all of these applications achieve monotonic convergence only when at least four moments are utilized. The reason for this is a general one connected to the structure of the formula Eq. (4.32), p. 76 see also Fig. 4.3, p. 76. Here the most probable occupancies are n = 3 and 4. Other occupancies are improbable relative to those cases, and terms of Eq. (4.32) other than n = 3 and 4 are extremely small. But n- is zero for terms n < k. Thus, final adjustments of the predicted probable populations await the moment information > 3, which makes direct adjustments to the largest terms of Eq. (4.32). After k > (n)o, subsequent adjustments are indirect, either through the consistency and normahzation requirements on the or through the extremely small terms of the sum. [Pg.185]

Abstract We present an explicit list of relevant formulae connecting the various coordinate sets for the representation of the potential energy surface of triatomic systems. The connections are made to those coordinates which give the potential energy surface dependence on the internuclear distances. Reference will also be made to computer programs which are made available on the Internet. Applications are indicated for molecular and chemical physics. [Pg.123]


See other pages where Connection formula applications is mentioned: [Pg.248]    [Pg.1000]    [Pg.462]    [Pg.239]    [Pg.92]    [Pg.70]    [Pg.17]    [Pg.465]    [Pg.66]    [Pg.470]    [Pg.320]    [Pg.279]    [Pg.312]    [Pg.391]    [Pg.65]    [Pg.294]    [Pg.88]    [Pg.34]    [Pg.75]    [Pg.131]    [Pg.127]    [Pg.1625]    [Pg.265]    [Pg.218]    [Pg.102]    [Pg.268]    [Pg.33]    [Pg.143]    [Pg.1625]    [Pg.395]    [Pg.53]    [Pg.265]    [Pg.308]    [Pg.1401]    [Pg.45]    [Pg.8]    [Pg.594]    [Pg.16]    [Pg.207]   
See also in sourсe #XX -- [ Pg.24 , Pg.29 ]




SEARCH



Applications formula

Connection formula

© 2024 chempedia.info