Excitation factor

Equation 4.79a points out the Reduced Isotopic Partition Function Ratio (RPFR) may be considered as the product of three factors the product factor (PF), the excitation factor (EXC), and the zero-point energy factor (ZPE). Note that in terms of RPFR s, the isotope effects corresponding to Equations 4.65, 4.66, and 4.68 can be written... 

The MMI (mass moment of inertia), EXC (excitation factor), and ZPE (zero point energy) terms are defined on successive lines of Equation 4.145. For reactions involving heavier isotopes the effects are no longer concentrated in the ZPE term and it is convenient to apply the Teller-Redlich product rule (Section 3.5.1) and eliminate the moments of inertia by using Equations 4.79,4.79a, and 4.141, thus obtaining an equivalent relation... 

The product of the excitation factors and the numerical factor of 0.92 may be assumed, with sufficient accuracy, to be unity. If the experimental data (kH/kT)Pa is put in the form AeBlTy one finds from the experimental value of 3.7 at 775°K that B is approximately 700 cm-1. In agreement with Weston, one must conclude this to be a more reasonable value for the difference in activation energies than 2060 cm"1 obtained by least squares. 

The total energy efficiency of ary non-equilibrium plasma-chemical process can be subdivided into three main components an excitation factor (jjex), a relaxation factor (jjrei), and a chemical factor ( chem) ... 

The energy efficiency of the plasma-chemical processes is usually divided into three factors excitation factor relaxation factor ()]rei), and chemical factor ()]chem)- The most... 

The total energy efficiency of the considered mechanism of H2O dissociation includes three major factors the excitation factor ) ex, related to the discharge energy fraction going to vibrational excitation the relaxation factor showing the effectiveness of the dissociation... 

A. The excitation factor. This factor depends on reduced electric field and electron tem-... 

Total energy efficiency q) of the non-equihbrium plasma synthesis of NO from air or N2-O2 mixtures, stimulated by vibrational excitation, can be subdivided into three factors the excitation factor q x), the relaxation factor ( rei), and the chemical factor (/jchem, to be considered in the next section) ... 

The excitation factor q ) is due to energy losses related to the excitation of low productive degrees of freedom. For the aforementioned mechanism, the percentage of discharge energy going to vibrational excitation of N2 is shown. Thus, at Te 1 eV, ) ex = 0.8-0.9 see Fig. 6-5. 

The value f may be referred to as the excitation factor. It is a complex function of excitation conditions and must be determined experimentally for every case. An exception is the thermal or equilibrium emission for which the ratio of excited to unexcited molecules (f) fits the Boltzmann distribution. 

Experimental determination of the excitation factor shows that with chemical luminescence excitation (chemiluminescence) in flames the f value is, as a rule, much higher than the thermal emission factor. This stems from the non-equilibrium nature of this kind of emission, directly related to the energy liberated by some or other elementary chemical process. This shows the high importance of chemiluminescence both for the identification of labile intermediates and for the elucidation of certain fine details of the chemical reaction mechanism. 

Since we have argued that bonding in moderately bound molecules is cooperative, we could explain similar trends in such systems in a completely different fashion A second bond will always be stronger than the first because of bond cooperativity, everything else being equal. That is to say, even if spatial excitation were to remain constant, reaction (12) would be more exothermic than reaction (10) because the first formed bond assists the formation of the next one. Now, the spatial excitation factor is an indisputable reality and what we have to show is that bond cooperativity does exist. We can demonstrate the existence of such a phenomenon if we could produce a set of data which show that, while reaction (10) requires less spatial excitation than reaction (12), the latter is nonetheless equally or more exothermic than the former because it profits from bond cooperativity. 

The modal factors Li and F, are termed the modal excitation factor and the modal participation factor, respectively. It is easy to verify that the values of both the factors F, and Li depend on the normalization used for [Pg.1516]

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