Trend Prediction

In particular, the experimental evidence that the curvature increases with decreasing supercooling is just the opposite of the trend predicted. The LH theory... 

The role of the solvent in polymer adsorption has been the subject of much discussion. For example, theories have made predictions about the effect of the polymer/solvent interaction (i.e. Flory Huggins x parameter) on adsorption. For many systems, x parameters had already been tabulated so that a number of adsorption studies focused attention on this parameter. In spite of much effort, available data are ambiguous, sometimes verifying and sometimes contradicting the trends predicted by theory. 

Comparison of the experimental data with the trends predicted from quantum chemistry ab initio simulations demonstrated that the multiple conductance values of Au-alkanedithiol-Au junctions could be attributed to different Au-sulfur coordination geometries and to different conformations of the alkyl chain. In particular, the medium conductance corresponds to an all-trans conformation of the alkyl chain, with each sulfur atom coordinated in atop position to a single... 

Fig. 25.4. Oxygen and carbon stable isotopic compositions of calcite ( ) and dolomite ( ) cements from Lyons sandstone (Levandowski et al., 1973), and isotopic trends (bold arrows) predicted for dolomite cements produced by the mixing reaction shown in Figure 25.3, assuming differing CO2 fugacities (25, 50, and 100) for the Fountain brine. Fine arrows, for comparison, show isotopic trends predicted in calculations which assume (improperly) that fluid and minerals maintain isotopic equilibrium over the course of the simulation. Figure after Lee and Bethke (1996).

The predictions of this model (normalized to meteoritic abundance for solar metallicity) are illustrated in Fig. 9.6 and compared with observational data for beryllium in stars, based on ground-based measurements of the near-UV Be II doublet A 3130. Assuming that surface Be can suffer some destruction in some of the metal-rich disk stars, there is fair agreement down to about 0.1 of solar abundance, but the secondary trend predicted at still lower metallicities is too steep. 

The measured uptake of CPA and PTA over the three activated carbons [55] is shown in Figure 6.28, and the trends predicted by the RPA model in Figure 6.27 are at least qualitatively observed. However, at high pH, over the two highest-surface-area carbons (CA and KB), uptake is about half of that predicted by the RPA model. The discrepancy was explained [55] by steric exclusion of the large Pt ammine complexes, believed to retain two hydration sheaths [15,19], from the smallest micropores of the high-surface-area activated carbon. 

The data compiled in Table 7.5 show that the relative energies of the axial and equatorial isomers yielded by the B3LYP/II level of theory are very similar to their CCSD(T) counterparts. The B3LYP/II BDEs are always larger than the CCSD(T)/II results, but the trends predicted by the two methods for different ligands are the same. It is worth noting... 

It largely obeys the trend predicted by Equation 1.4. Maximal retention may be expected when both selector and analyte are dissociated to a high degree (i.e., where the product of and reaches a maximum value). For carboxylic acids, this retention maximum is usually found between pH 5 and 6, where the enantiose-lectivity also adopts its optimum (see Figure 1.5). Above this pH, the retention is decreased because (i) the dissociation of the selector becomes increasingly reduced, (ii) the effective counterion concentration may be increased, and (iii) the superimposed hydrophobic retention increment of the solute on the bonded phase loses its... 

The qualitative trend predicted by this equation is that, when the heat of solution is negative (the dissolution is exothermic, i.e., heat is evolved, the enthalpy of solvation is more negative than the lattice enthalpy is positive), the solubility diminishes with increasing temperatures. The opposite trend is observed for endothermic dissolution. An analogue of Eq. (2.58), with H replacing G, and the same tables [12] can be used to obtain the required standard enthalpies of solution of ionic solutes. No general analogues to Eqs. (2.53)-(2.55) are known as yet. 

In general, the trends predicted by -propylperoxy radical, 1-butoxy radical, and -pentyl radical provide good benchmarks for understanding the oxidation chemistry of longer chain radicals. For instance, 1,5-H-atom transfer and... 

Rainbow scattering has been detected from high Miller Index stepped platinum surfaces. Typical rainbow scattering patterns are shown in Fig. 4.7. The increase in intensity of the surface rainbows, as displayed by this figure, for an increase in the angle of incidence, qualitatively follows the trend predicted from calculations by McClure... 

Hence, the trend predicted by the Kapitsa theory is supported by the recent, more accurate, film thickness measurements. This does not indicate, however, that the Kapitsa theory will apply in detail over the whole wavy laminar regime of film flow, since Kapitsa (K7) pointed out that such a reduction in the mean thickness should result for other types of wavy flow besides the particular case considered in his theory. 

The stability of a number of polymer latices has been examined and some typical values are reported in Table II. The trends observed are qualitatively in agreement with the trends predicted by the theoretical approach outlined in this section for particles with smooth surfaces, with a homogeneous distribution of surface charges ( p everywhere the same) using simple electrolytes, i.e. those wfiich do not interact chemically with water to form new ionic species. 

The relative viscosity curve predicted by Eq. 4.55 is plotted in Figure 4.11. Experimental viscosities for several common solvents are also shown in the figure these data points verify the trends predicted above. 

CgB is practically independent of pressure in distillation systems (21,25 see also cyclohexane-n-heptane curves on Fig. 6.9a), This suggests that CSB is, at the most, only a very weak function of physical properties. Further, it suggests that any physical property variations that accompany a change in distillation pressure (and, therefore, also in the equilibrium temperature), do not affect CSB. This contradicts trends predicted by some of the earlier flood correlations (18-20). 

Secondary Intermolecular Nonequilibrium Isotope Effects for Radicals. The decompositions of chemically activated alkyl radicals provide many of the present examples of these normal isotope effects. Since ea is closely similar for all cases, but e ,jnt varies, the magnitudes of the effect per D atom should show the trend predicted in Sec. II-D, 2. 

Complexes of the type [Rh(TPP)(RX)] [RX = C H X (n = 3-5, X = Cl or Br n = 3-6, X = I) TPP = dianion of tetraphenylporphyrin] were prepared by Anderson et al. (179). The nature of RX was found to determine the overall electrochemical behavior for the reduction of [Rh(TTP)(RX)]. For some complexes, specifically those where X = Br and I, the bound alkyl halide could be reduced without cleavage of the metal-carbon bond. This resulted in the electrochemically initiated conversion of [Rh(TPP)(RX)] to a [Rh(TPP)(R)] complex. The E. value for this reduction was dependent on the chain length and halide of the RX group and followed the trend predicted for alkyl halides. The reduction of the bound RX occured at Ei values significantly less negative that those for reduction of free RX under the same solution conditions. 

Semiempirical MNDO calculations have been carried out on model pyrylium and thiopyrylium systems (88MI1). The calculated HOMO-LUMO gap in the gas phase correlates well with experimental absorption maxima obtained in solution. Ionization potentials and electron affinities predicted by Koopmans theorem with MNDO orbital energies do not track the observed trends in the experimental redox values. In contrast these are paralleled by the trends predicted by A// values calculated by MNDO and AMI for the open-shell and closed-shell species. 

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