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Empirical results

The empirical results contained in Fig. 2.10 present us with three challenges ... [Pg.105]

A more practically useful work index based on empirical results from ball milling trials has been developed (7—9) and is expressed by equation 1 ... [Pg.139]

Figure 2.3.1 (Wachtel, et al, 1972) shows the ARCO reactor that tried to simulate the real reaction conditions in a fluid cracking unit. This was a formal scale-down where many important similarities had to be sacrificed to get a workable unit. This unit was still too large for a laboratory study or test unit, but instead was pilot-plant equipment that could still give useful empirical results Since this serves a very large industry, it may pay off to try it, even if it costs a lot to operate. Figure 2.3.1 (Wachtel, et al, 1972) shows the ARCO reactor that tried to simulate the real reaction conditions in a fluid cracking unit. This was a formal scale-down where many important similarities had to be sacrificed to get a workable unit. This unit was still too large for a laboratory study or test unit, but instead was pilot-plant equipment that could still give useful empirical results Since this serves a very large industry, it may pay off to try it, even if it costs a lot to operate.
Substituent effects as evaluated on the basis of the Hammett equation and its extended forms, are - this has to be emphasized again — empirical results. Nevertheless, it is very soothing to know that theoretical approaches, i. e., calculations of substituent effects using ab initio molecular orbital theory (Topsom, 1976, 1981, 1983 Taft and Topsom, 1987, STO-3G and 4-31G level), give results that are consistent with the experimental data. However, it is not recommended to use only theoretically calculated substituent constants and values for F, R, and other parameters for the interpretation of experimental data. [Pg.150]

Each reaction has its own characteristic equilibrium constant, with a value that can be changed only by varying the temperature (Table 9.2). The extraordinary empirical result, which we justify in the next section, is that, regardless of the initial composition of a reaction mixture, the composition tends to adjust until the... [Pg.482]

Another approach to assess the partitioning of metals among the phases comprising natural particulate matter is to sequentially and selectively extract or dissolve portions of natural particulate matter. Based on the release of trace metals accompanying each step, associations between the trace metal and the extracted phase are inferred. Both of the above approaches have drawbacks, and at this time it is impossible to predict in advance how and to what extent metals and particulate matter will bond to one another in a natural system. Despite the uncertainties, empirical results can often be interpreted using the framework provided here. [Pg.394]

Particles Stress Equations Derived from Empirical Results. 71... [Pg.36]

As already mentioned in the introduction, various fundamental and many empirical results have been published. Although photoelectrochemical cells are easily made, many problems concerning the stability of semiconductors and the function of catalysts still remain to be solved. There are few other approaches such as for instance sensitization (see e.g.) which are not treated here. In addition it should be mentioned that photoelectrochemical systems have been used for light induced synthesis of organic compounds (see e.g.) which could also not be considered in this article. [Pg.109]

The Wd estimated from the RASCI is compared with other theoretical calculations [46, 54] in Table V. The present DF estimate of Wd deviates by 21%(29%) from the SCF (RASSCF) estimate of Kozlov et al. [46] and by 17% from the semiempirical result of Kozlov and Labzovsky [54], while our RASCI result departs by 6% (3%) from the SCF-EO (RASSCF-EO) treatment of Kozlov et al. [46] and is in good agreement with the semi-empirical result of Kozlov and Labzovsky. At this juncture, we emphasize that our computed ground state dipole moment of BaF (p(. = 3.203 debyes) is also reasonably close to experiment p(. = 3.2 debyes (see Table 5 of Ref. 38). [Pg.258]

The HO—LU interaction came early to the notice of theoreticians. Hiickel 74> pointed out the role of LU in the alkaline reduction of naphthalene and anthracene. Moffitt 75> characterized the formation of S03, SO2CI2, etc. by the reactions of SO2 as an electron donor with the S-atom-localiz-ing character of HO MO. Walsh 76) considered that the empirical result of producing nitro compounds in the reaction of the nitrite anion with the carbonium ion should be attributed to the HO of the NO2 anion which is localized at the nitrogen atom. [Pg.43]

The empirical results provided by Borrell17 indicate that the price elasticity of aggregate demand for each therapeutic chapter appears to be much higher than time-series and cross-national studies have shown. Thus, price restriction may be a powerful explanatory factor for the large amount of pharmaceuticals consumed per person in Spain. [Pg.219]

Fig. 1. Result from the subset analysed so far. The data are binned in metallicity to reflect the typical uncertainty on our determination of [Fe/H], marked by horizontal error-bars. The median value of 5(My) in each metallicity bin is plotted as filled squares, with the vertical error-bars representing its associated error. For comparison we also plot the empirical results from [5] in two Cepheid fields in Ml 01 (open circles and solid line) and the theoretical predictions by [2] from non-linear pulsational models (dashed line)... Fig. 1. Result from the subset analysed so far. The data are binned in metallicity to reflect the typical uncertainty on our determination of [Fe/H], marked by horizontal error-bars. The median value of 5(My) in each metallicity bin is plotted as filled squares, with the vertical error-bars representing its associated error. For comparison we also plot the empirical results from [5] in two Cepheid fields in Ml 01 (open circles and solid line) and the theoretical predictions by [2] from non-linear pulsational models (dashed line)...
There is no theoretical ground for this conclusion, which is a purely empirical result based on a variety of experimental measurements. However, it seems to apply everywhere and to represent a law of Nature, stating that systems consisting of more than one particle of half-integral spin are always represented by anti-symmetric wave functions. It is noted that if the space function is symmetrical, the spin function must be anti-symmetrical to give an anti-symmetrical product. When each of the three symmetrical states is combined with the anti-symmetrical space function this produces what is... [Pg.244]

The Ahmad and Faeth [18] data encompass alcohols saturated into an inert wall of xp up to 150 mm and xf up to 450 mm. Typically, qf is roughly constant over the visible flame extension (4) with values of between 20 and 30 kW/m2. The same behavior is seen for the radiatively enhanced burning of solid materials - again showing q values of 20-30 kW/m2 over 4 for Xf up to 1.5 m. These data are shown in Figure 8.13. Such empirical results for the flame heat flux are useful for obtaining practical estimates for upward flame spread on a wall. [Pg.207]

This empirical result is consistent with the theoretical analysis of the partial-wave expansion (where the truncation of the FCI expansion is based on the angular-momentum quantum number rather than on the principal quantum number n), for which it has been proved that the truncation error is proportional to L-3 when all STOs up to l = L are included in the FCI wavefunction [49, 50],... [Pg.15]

Attention. In pursuing high ee of the digested products (more reactive enantiomers) under kinetically resolving conditions, termination of the reaction at the proper conversion is very important. When the relationship between conversion and ees of the digested product and of the unaffected substrate was calculated using the mathematical model of Chen et al., it was predicted that 80 % conversion should be the critical point, as depicted in Figure 5.3, which corroborated the empirical results mentioned in steps 2 and 3. [Pg.197]

Example 1 - Customer loyalty and customer profitability. Investments made in customer loyalty initiatives are largely justified by an assumed positive influence on profitability. The empirical results of Reinartz and Kumar (2002), however, challenge the assumption that higher loyalty is associated with increased profits. They examine the... [Pg.193]

Demonstration of the capability of electrodeposition to produce materials with predesignable, variable, and controllable composition down to practically the atomic scale constitutes an important step toward the realization of custom-tailored materials. On the theoretical side, the lack of a single satisfactory theory for the possible explanation of the different empirical results is somewhat disappointing. [Pg.305]

Photoelectron spectroscopy studies on 72 and 74 were carried out by another Basel chemist, Edgar Heilbronner. Tentative orbital energy assignments of 72 were made by him on the basis of a simple MO model calculation and the crystal structural data of 72. These assignments were unambiguously verified by the empirical results obtained from the less symmetrical 74. ... [Pg.124]

A number of works have focused on the pattern dependencies in tungsten (both tungsten via and local interconnect) polishing [12,19,21]. To first order, empirical results seem to suggest that dishing is dominated by the width or size of the metal feature being polished wide lines tend to suffer... [Pg.126]

STO-3G computations, and the experimental shifts of olefinic sp carbon atoms [40] yields a result similar to that observed for sp carbons again we have three equidistant parallel regression tines, depending on the number of H atoms attached to the olefinic carbon. The analysis by means of Eq. (5.9), on the other hand, leads to p = 31.8 + 4 me, that is, in essence, the value found for the sp carbons, 30.12 me [40], Energy calculations [109] led to the empirical result = 7.7 me for the ethylene carbon atom. [Pg.60]


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See also in sourсe #XX -- [ Pg.165 ]




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Empirical Results Higher Order Properties

Empirical Results Single Proteins

Results of Semi-Empirical Calculations

Review of empirical results on individual effects

Semi-empirical Results

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