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Tabulation Approaches

Meisel and Collins were among the first authors who used this principle and called it the repro-modelling approach. Meisel and Collins suggested that within a large complex model, it is worth identifying very time-consuming subtasks which are used frequently, where the results depend only on the values of a few variables (Meisel and Collins 1973). It is immediately obvious that the presence of [Pg.260]


Chatzopoulos, A.K., Rigopoulos, S. A chemistry tabulation approach via rate-controlled constrained equilibrium (RCCE) and artificial neural networks (ANNs), with application to turbulent non-premixed CH4/H2/N2 flames. Proc. Combust. Inst. 34, 1465-1473 (2013)... [Pg.294]

In this second empirical approach, which has also been used for C NMR spectra, predictions are based on tabulated chemical shifts for classes of structures, and corrected with additive contributions from neighboring functional groups or substructures. Several tables have been compiled for different types of protons. Increment rules can be found in nearly any textbook on NMR spectroscopy. [Pg.522]

The reactivity ratios of a copolymerization system are the fundamental parameters in terms of which the system is described. Since the copolymer composition equation relates the compositions of the product and the feedstock, it is clear that values of r can be evaluated from experimental data in which the corresponding compositions are measured. We shall consider this evaluation procedure in Sec. 7.7, where it will be found that this approach is not as free of ambiguity as might be desired. For now we shall simply assume that we know the desired r values for a system in fact, extensive tabulations of such values exist. An especially convenient source of this information is the Polymer Handbook (Ref. 4). Table 7.1 lists some typical r values at 60°C. [Pg.431]

The special appeal of this approach is that it allows the heat of mixing to be estimated in terms of a single parameter assigned to each component. This considerably simplifies the characterization of mixing, since m components (with m 6 values) can be combined into m(m - l)/2 binary mixtures, so a considerable data reduction follows from tabulating 6 s instead of AH s. Table 8.2 is a list of CED and 6 values for several common solvents, as well as estimated 6 values for several common polymers. [Pg.526]

The check sheet shown below, which is tool number five, is a simple technique for recording data (47). A check sheet can present the data as a histogram when results are tabulated as a frequency distribution, or a mn chart when the data are plotted vs time. The advantage of this approach to data collection is the abiUty to rapidly accumulate and analy2e data for trends. A check sheet for causes of off-standard polymer production might be as follows ... [Pg.371]

Here it is possible to consider how the starting materials may react and to check the result with the help of the spectra. Another approach would start by tabulating the C shifts, CH multiplicities... [Pg.200]

If you calculate AG° in this way, you should keep in mind an important limitation. AG°reacUon is valid only at the temperature at which AG data are tabulated, in this case 25°C. AG° varies considerably with temperature, so this approach is not even approximately valid at other temperatures. [Pg.462]

Effects of Cold Gas Recycle and Approach to Equilibrium. Product gases resulting from various CGR ratios were analyzed (Table XI). For the experiments tabulated, a decrease in the cold recycle ratio resulted consistently in increases in the product gas concentrations of water vapor, hydrogen, and carbon dioxide and a decrease in methane concentration. These trends may be noted in experiment HGR-12 as the CGR ratio decreased from 8.7 1 to 1.2 1, in experiment HGR-13 as it increased from 1.0 1 to 9.1 1, and in experiment HGR-14 as it decreased from 3.0 1 to 1.0 1. These trends indicate that the water-gas shift reaction (CO + H20 —> C02 + H2) was sustained to some degree. Except for the 462-hr period in experiment HGR-14, the apparent mass action constants for the water-gas shift reaction (based on the product gas compositions in Table XI) remained fairly constant at 0.57-1.6. These values are much lower than the value of 11.7 for equilibrium conversion at 400°C. In... [Pg.118]

The last comprehensive review of reactions between carbon-centered radicals appeared in 1973.142 Rate constants for radical-radical reactions in the liquid phase have been tabulated by Griller.14 The area has also been reviewed by Alfassi114 and Moad and Solomon.145 Radical-radical reactions arc, in general, very exothermic and activation barriers are extremely small even for highly resonance-stabilized radicals. As a consequence, reaction rate constants often approach the diffusion-controlled limit (typically -109 M 1 s"1). [Pg.36]

Jones et al. [73] have provided an alternative approach to the linearization of data using the tabulated reduced time values given by Sharp et al. [70]. The experimental data are expressed in the form ae as a function of (t/t0.s)ei where the subscript e refers to the experimental data. Three broadly equivalent methods of plotting can be used. [Pg.78]

A few functional dihalides have been prepared. Some of these monomers are tabulated in Table 6.2. The monomers could be nitrated and then reduced to amine-functionalized monomers (Scheme 6.26).203 This approach was used to nitrate DCDPS or bis-4-fluorophenyl phenyl phosphine oxide.204 These monomers were used to copolymerize with some other activated dihalides as the comonomers. [Pg.356]

Using either of the above approaches we have measured the thermal rate constants for some 40 hydrogen atom and proton transfer reactions. The results are tabulated in Table II where the thermal rate constants are compared with the rate constants obtained at 10.5 volt cm.-1 (3.7 e.v. exit energy) either by the usual method of pressure variation or for concurrent reactions by the ratio-plot technique outlined in previous publications (14, 17, 36). The ion source temperature during these measurements was about 310°K. Table II also includes the thermal rate constants measured by others (12, 13, 33, 39) using similar pulsing techniques. [Pg.166]

We offer two approaches for obtaining AH and AG values for these conditions. In the most straightforward approach, the functions (G — H)/T and (H — H29s)/T, are tabulated for extensive temperature ranges for many simple molecules. The advantage of these functions is... [Pg.90]

Molecules and Clusters. The local nature of the effective Hamiltonian in the LDF equations makes it possible to solve the LDF equations for molecular systems by a numerical LCAO approach (16,17). In this approach (17), the atomic basis functions are constructed numerically for free atoms and ions and tabulated on a numerical grid. By construction, the molecular basis becomes exact as the system dissociates into its atoms. The effective potential is given on the same numerical grid as the basis functions. The matrix elements of the effective LDF Hamiltonian in the atomic basis are given by... [Pg.53]

Both approaches to study day calculation are used in the pharmaceutical industry, although the algorithm in Program 4.3 is probably used more often. The CDISC Submission Data Tabulation Model states that you should use the algorithm in... [Pg.90]

This chapter first explores the general approach to creating any statistical table or listing. Then it examines PROC REPORT and PROC TABULATE as possible stand-alone methods of clinical trial reporting. Next, examples of several common clinical trial tables are presented. Finally, issues concerning the appearance of the output are discussed. [Pg.126]

The relationships of the type (3.1.54) and (3.1.57) imply that the standard electrode potentials can be derived directly from the thermodynamic data (and vice versa). The values of the standard chemical potentials are identified with the values of the standard Gibbs energies of formation, tabulated, for example, by the US National Bureau of Standards. On the other hand, the experimental approach to the determination of standard electrode potentials is based on the cells of the type (3.1.41) whose EMFs are extrapolated to zero ionic strength. [Pg.175]


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Tabulation

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