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Logic second order

This expression suggests a rate-controlling step in which RM reacts with an intermediate. If so, [Int] °c [RM] /2. To be consistent with this, the initiation step should be first-order in [RM] and the termination step second-order in [Int]. Since O2 is not involved in the one propagation step deduced, it must appear in the other, because it is consumed in the overall stoichiometry. On the other hand, given that one RM is consumed by reaction with the intermediate, another cannot be introduced in the second propagation step, since the stoichiometry [Eq. (8-3)] would disallow that. Further, we know that the initiation and propagation steps are not the reverse of one another, since the system is not well-behaved. From this logic we write this skeleton ... [Pg.188]

A second fluorine substituent shields in the ortho- and especially in the para-position, but one in the meta-position deshields, with 1,3-5-trifluorobenzene having the most deshielded fluorines in a polyfluoro-aromatic system (Scheme 3.58). On the other hand, hexafluorobenzene has highly shielded fluorines. The fluorine spectra of these multifluoro-benzenes are second order in nature and their appearance is thus not generally predicable on the basis of first-order logic. [Pg.94]

Graphic Method A plot of the data can be used to ascertain the order. If a plot of concentration versus time yields a straight line, the reaction is zero order. A straight line from the plot of logic/ - x) versus time is first order and second order if the plot of 1 /(a - xf versus time is a straight line (where the initial concentrations are equal). [Pg.690]

One possible method of automatic optimization was mentioned by Kahn (Kl) quite some time ago. This used the Monte Carlo technique to make a random design of cases over a broad area known to contain the optimum. After a limited number of cases had been calculated, the best case was selected and another random design of cases was made. For the second design, however, the dispersion of cases was reduced so that the investigation became more localized. After a sufficient number of repetitions of this process the optimum would be determined to a sufficient degree of accuracy. The method is perhaps the antithesis of a logical or orderly calculation procedure, but it can be programmed for automatic sequential calculation. [Pg.360]

Because of the complexity of the ash formation and ash deposition process, it seems logical to deal first with those key coal constituents most responsible for ash deposition. The iron and sodium contents of an ash have typically been considered key constituents. Techniques have been developed to determine how these key constituents are contained in the coal, i.e., the particular mineral forms that are present or the grain size of the constituent in question. Obviously the remainder of the mineral matter has an effect, but depending on the concentration and form in which iron and/or sodium constituents are present, the remaining mineral matter often has second order effects. [Pg.292]

In the forward sense this reaction exemplifies a logically necessary aspect of chain mechanisms, namely independent initiation. The reverse step, which is second order in chain centre concentration, represents one of the important subgroups of chain terminating reactions. Their occurrence, as that of chain propagation, necessarily depends upon the presence of the chain centres, and is usually manifested in the kinetics by at least a first order factor. In combination, these particular initiation and termination steps lead to a chain centre concentration which approaches an equilibrium level dependent only upon the reaction conditions and thermodynamics. [Pg.87]

The logical extension of GGA methods is to allow the exchange and correlation functionals to depend on higher order derivatives of the electron density, with the Laplacian (V ) being the second-order term. Alternatively, the functional can be taken to depend on the orbital kinetic energy density t, which for a single orbital is identical to the von Weizsacker kinetic energy Tw (eq. (6.3)). [Pg.250]

To go beyond (66) we shall proceed to second order in F ordering, supplemented by some further approximations to simplify the form of our final results. The second-order F-ordered approximation, which we shall call SOGA, requires knowledge of F (1 2), and the logic of F ordering demands that the F (l 2) used in the expression F(1 2) = F (1 2)+F (l 2), like 2) itself, be exact to one higher order in y than the lowest-order result. Thus we seek an F (l 2) that is exact through y for fixed ti2 to accompany an... [Pg.62]

Computational analysis of stereoelectronic involvement in TS stabilization is complicated by the intrinsically delocalized nature of transition states. The stretched and/or deformed bonds of the TS (or the forming incipient bonds) are sufficiently different from the normal 2c,2e bonds with the very large o/a or jt/jt separation. This difference complicates comparisons based on the usual logic and intuition derived from the stable ground state structures. For NBO analysis, the choice of a reference point in estimating delocalization can be contentious. Furthermore, the interactions are so strong that the mathematics of second order perturbation estimation is suitable for only very crude approximations. [Pg.240]

Our hardware model terms are of first order. On the other hand it is very useful to be able to deal with higher order logic (mostly second order) in order to develop and prove hardware model term rewriting rules and to support definitions by using higher order patterns. [Pg.294]


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See also in sourсe #XX -- [ Pg.115 ]




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