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Facilitation factor, calculation

Abramovitch, Roy, and Uma 51> disagreed with this, pointing out a number of inconsistencies with that conclusion. Thus, while the total rate ratios are not much different from unity, as expected for a homolytic substitution, the values of °h A = 1.0, °HeA = 0.96, and °hA = 0.80 do not support this mechanism since such electron-donating substituents should facilitate attack by an electrophilic free radical 59-60> and lead to total rate ratios greater than unity. Also, the partial rate factor calculated for attack at the meta position of toluene was unusually low, and it is not clear why this position should be deactivated towards attack either by a free radical or by an electrophilic species. [Pg.25]

The factor f reduces the oscillation amplitude symmetrically about R - R0, facilitating straightforward calculation of polymer refractive index from quantities measured directly from the waveform (3,). When r12 is not small, as in the plasma etching of thin polymer films, the first order power series approximation is inadequate. For example, for a plasma/poly(methyl-methacrylate)/silicon system, r12 = -0.196 and r23 = -0.442. The waveform for a uniformly etching film is no longer purely sinusoidal in time but contains other harmonic components. In addition, amplitude reduction through the f factor does not preserve the vertical median R0 making the film refractive index calculation non-trivial. [Pg.237]

The effects of antioxidants on OT of SME by non-isothermal (conventional) DSC, static mode P-DSC, and dynamic mode P-DSC were investigated by Dunn (2006a), which is summarized in Table 1.15. Results from all three methods consistently showed that treating SME with antioxidants TBHQ and a-tocopherol increased OT with respect to untreated SME. Statistical comparison of P-DSC results with those from isothermal analysis of OSI at 60°C was facilitated by calculation of the corresponding response factors (defined ratios of OT of the sample to that of methyl oleate, and of OSI of the sample to that of methyl oleate). Data for the sample and reference material (methyl oleate) were measured under the same experimental conditions. Results showed the highest degree of correlation (P = 0.79) between dynamic-mode P-DSC and isothermal OSI analyses. [Pg.39]

The parameters K, e and a can be used to calculate a facilitation factor, F, which is defined as ... [Pg.29]

Once the properties of the system are known, equation 5 can be used to calculate facilitation factors which can be compared to the experimental data. The properties used In the calculation are summarized in Table 2. [Pg.134]

The agreement is excellent. Since the equilibrium constant and the complex dlffuslvlty were not independently measured, this approach is semlempirlcal, yet it is very valuable as it allows calculation of facilitation factors at conditions that were not studied experimentally. [Pg.134]

This is the first study of HjS facilitated transport of PFSA lono-mers. Hydrogen sulfide and methane fluxes were measured at ambient conditions for 200 urn PFSA membranes containing monopositive EDA counterions as carriers. Facilitation factors up to 26. 1 and separation factors for H S/CH up to 1200 were observed. The H S transport is diffusion limited. The data were well represented by a simplified reaction equilibrium model. Calculation of dimensionless groups indicates that HxS transport would be diffusion limited even at a membrane thickness of 1 um. [Pg.135]

The index layer is composed of the evaluation factors capable of reflecting the characteristics of water resources allocation system. They are measured by quantification, analysis and comparison of the index, which could obtain the degree of the harmoniousness of water resources allocation more scientifically. The corresponding evaluation indexes for each system of the criterion layers are set up, which is widely ranged thanks to the complexity of these systems. Therefore, in order to seize the key to determine the mode of water resources development and facilitate the calculation of the evaluation, the most representative and key indicators will be selected, and the indicators which have little to do with the research purpose should be abandoned. [Pg.115]

According to this approximation method, the facilitation factor F can be calculated by solving the following simultaneous algebraic equations. [Pg.241]

Experiments on the separation of CO2 from CH4 by the supported liquid membranes containing aqueous amines such as monoethanolamine, diethanolamine and ethylenediamine hydrochloride were performed, and tfie data were discussed quantitatively on the basis of facilitated transport theory. The effects of the chemical properties of amines such as the reaction rate constant and chemical equilibrium constant and also the effect of the CO2 partid pressure on the permeation rate of CO2 could be interpreted by the proposed theory. It was propos to use L as the effective diffusional path length in the calculation of the facilitation factor, where L is the membrane thickness and x is the tortuosity factor of the microporous support membrane. The permeation rates of CH4 was found to provide useful information for evaluating the solubilities of CO2 in the reactive membrane solutions. [Pg.250]

Various mathematical models have been developed to describe facilitated transport in liquid membranes (32-39). Under certain conditions (rapid complexation kinetics, large facilitation factors) the models allow calculation of the separation factor... [Pg.290]

The explicit separation of vibrations in the multidimensional GF of Theorem 4.4 allows an effective reduction of the number of degrees of freedom and facilitates the calculation of transition rates. In this regard, it cannot be too strongly emphasized that the calculation of transition rates in the parallel-mode approximation has a fundamental inadequacy that is evident from the derivation above. The defect emerges, if we return to the case of N-vibrational modes some of which are not parallel to each other. This situation occurs if the latter have the same symmetry, especially if they are totally symmetric in the molecular group. In this case, the complexity introduced by the reciprocal (4.69a) and interactive displacement parameters (Equations 4.69b and 4.69c) is considerable and this fact cannot be overlooked in any parallel-mode estimate of the transition probability. Even with considerable effort, it is impossible to factor the exact GF into a product of one-dimensional GF. [Pg.93]

There are three main methods for calculating electron correlation Configuration Interaction (Cl), Many Body Perturbation Theory (MBPT) and Coupled Cluster (CC). A word of caution before we describe these methods in more details. The Slater determinants are composed of spin-MOs, but since the Hamilton operator is independent of spin, the spin dependence can be factored out. Furthermore, to facilitate notation, it is often assumed that the HF determinant is of the RHF type. Finally, many of the expressions below involve double summations over identical sets of functions. To ensure only the unique terms are included, one of the summation indices must be restricted. Alternatively, both indices can be allowed to run over all values, and the overcounting corrected by a factor of 1/2. Various combinations of these assumptions result in final expressions which differ by factors of 1 /2, 1/4 etc. from those given here. In the present book the MOs are always spin-MOs, and conversion of a restricted summation to an unrestricted is always noted explicitly. [Pg.101]

From this further analysis, the actual amount of waste (and its nature) per kilogram of product will become evident. At this stage it is also important to look forward and assess options for recycling or reusing the waste on site for example if a solvent can be efficiently recovered then this should be taken into account in calculating the E-factor. Although the choice of which route to fully optimize may not be obvious even from this further analysis, it will facilitate a reasoned discussion of the issues. [Pg.48]


See other pages where Facilitation factor, calculation is mentioned: [Pg.88]    [Pg.169]    [Pg.308]    [Pg.320]    [Pg.1739]    [Pg.320]    [Pg.80]    [Pg.319]    [Pg.306]    [Pg.53]    [Pg.459]    [Pg.1733]    [Pg.14]    [Pg.126]    [Pg.806]    [Pg.201]    [Pg.626]    [Pg.401]    [Pg.409]    [Pg.58]    [Pg.435]    [Pg.241]    [Pg.242]    [Pg.249]    [Pg.115]    [Pg.121]    [Pg.722]    [Pg.2903]    [Pg.319]    [Pg.2109]    [Pg.2271]    [Pg.386]    [Pg.248]    [Pg.314]    [Pg.511]   
See also in sourсe #XX -- [ Pg.289 ]




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