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Surface predicted

Yet at 0.1 V/s the anodic peak due to the oxidation of the radical cation does not exhibit the shape characteristic of stripping of a solid phase. At faster scan rates the anodic peak broadens considerably and splits into two peaks the same behavior is noticeable in Figure 1. We do not have an explanation for this phenomenon. A recent theoretical treatment of redox molecules attached to electrode surfaces predicts that under certain conditions an anodic surface wave can broaden and split with increasing scan rate in a manner shown in Figure 3 (16). However the same theory predicts that the corresponding cathodic peak normalized to constant scan rate will increase with increasing scan rate. The latter prediction is not observed in our system. [Pg.435]

In every case in which a kinetic model is selected to represent adequately a reaction, the rate surface predicted by the model must be compared to the surface observed in the data. In the methods discussed in Section II, only one section through the entire rate surface was examined for example, the dependence of initial rate on total pressure could be investigated when in fact the total rate surface constituted the dependence of rate on several component partial pressures and temperature. The misleading results obtain-... [Pg.154]

Assume the two inputs you chose in Problem 12.1 will exhibit factor interaction. If they would be expected to interact, what would be the mechanistic basis of that interaction What might be the approximate mathematical form of that interaction Would you use a mechanistic or empirical model to approximate the response surface Why Sketch the response surface predicted by this model. [Pg.275]

Eliminate the interaction terms from the model you chose in Problem 12.3 and sketch the response surface predicted by this simpler model. How dissimilar is this sketch from the sketch made in Problem 12.3 How important does the interaction term seem to be ... [Pg.275]

FIGURE 2.15 Response surface predictions from haze intensity observations made with 30 combinations of gliadin and TA at pH 4.5. Reprinted with permission from Siebert and Lynn (2000). Copyright 2000 American Society of Brewing Chemists. [Pg.71]

These results are remarkably close to each other e.g., for an extreme value of = 0.5 the fresh surface prediction is only 6% larger than the surface stretch prediction. The amplitude of the area oscillation, e, has a relatively small effect since = 0.3 in many systems (R3, Yl). [Pg.197]

Lu, X. and Lin, M. C. Bonding configurations of acetylene adsorbed on the Si(100)-2x 1 surface predicted by density functional cluster model calculations. Physical Chemistry Chemical Physics 2, 4213 1217 (2000). [Pg.390]

The calculation of the PE surface is basically quantum mechanical. Accurate surfaces are used to show how the topography of the surface affects the reaction unit as it changes configuration across the surface. Predictions can be made, and these can be tested by molecular beams, spectroscopic techniques and chemiluminescence. [Pg.165]

The scattering intensities observed in the experiment with WS2 were used to discriminate between the different sites at which the H atoms might adsorb on the WS2 surface. Predictions based on three possible models for the structure were compared with the results and the authors deduced that the model in which the H occupies an on-top site above the S atoms, was the one which most closely simulated the data. [Pg.58]

Of course, when the potential of the surface becomes sufficiently large, the linear approximation fails, and the (exponential) increase in the counterions density in the vicinity of the surface predicted by the Poisson—Boltzmann equation largely exceeds the depletion of co-ions and the available volume is expected to become smaller than that in the bulk. [Pg.337]

The fluctuations increase the equilibrium thicknesses of the films (see Figures 5, 6a, and 7a), an effect which is particularly important for the common black films (see Figure 7a). This effect was found in the experiments of Exerowa et al.,2 who noted that the DLVO theory (for planar surfaces) predicts a too small repulsion and suggested that the hydration force (which has a shorter range) cannot account for the discrepancy. [Pg.540]

Therefore, even in the absence of surface dipoles, the polarization model for the hydration/double layer predicts qualitatively different results from those of the traditional theory at moderate and high ionic strengths. At low electrolyte concentrations, the quantitative differences between the two models, far away from the surface, can be accounted for by suitable modifications of the surface charge. The shape of the electric field and polarization within a few Angstroms from the surface, predicted by the two models, are however different at all electrolyte concentrations. [Pg.581]

For polyelectrolytes, analyses of equilibrium adsorption are only beginning to emerge. Muthukumar s (1987) treatment of a single polyelectrolyte chain interacting with a charged surface predicts adsorption with a mean square end-to-end distance of 0(k 1) when... [Pg.219]

The different reactivity of MgO versus CaO surfaces predicted by cluster calculations [95] has been recently confirmed by metastable impact electron spectroscopy (MIES) experiments on CO2 adsorption on MgO [100] and CaO [101] as well as by synchrotron based photoemission spectroscopy on the same systems [102,103] while the CaO surface exposed to CO2 is highly reactive and becomes terminated by carbonate complexes, on the MgO surface CO2 chemisorption does not take place at regular sites but only at defect sites, presumably the O " ions at the step or comer sites. [Pg.109]

Figure 3. Response surface—predicted Izod for compositions in experimental... Figure 3. Response surface—predicted Izod for compositions in experimental...
Figure 5. Response surface—predicted yield strength for compositions in experimental region. Figure 5. Response surface—predicted yield strength for compositions in experimental region.
Results of calculations of the potential energy surface predict the existence of weakly bound intermediate complexes. This implies a complex, multi-step reaction mechanism. The profile of the potential energy surface of the reaction systems is shown in Fig. 19. [Pg.176]

Here, F is the Faraday constant and R is the ideal gas constant. However, this model of charge development on surfaces predicts that surface charge should increase exponentially as the pH is adjusted away from the point of zero charge, PZC. [Pg.115]

Both endoproteinases and chemicals can be used to cleave the protein, provided they are active at conditions optimal for complex formation. Table 4.5 provides a list of 13 commercially available proteinases which are useful for protein footprinting. The majority of chemicals reactive towards proteins suffers from the drawback of being reactive towards nucleic acids as well. Hydroxyl radicals produced from H202 in the vicinity of Fe2+ ions are, however, useful for protein surface predictions and for mapping DNA-13 and RNA binding sites (Fig. 4.1423) on proteins. [Pg.150]

Zhou and Shan [29] and Fariselli et al. [26] employed neural networks to combine sequence and structural information for the prediction of whether a residue is located in an interaction site of a protein with a known structure. Bradford et al. [30] used a Support Vector Machine approach to identify interface residues using sequence neighbors. In both cases, the interaction surfaces are represented as surface patches of neighboring residues with their associated sequence profiles (derived from multiple alignments). The accuracy of these methods is 70% for interaction-surface prediction. [Pg.233]


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See also in sourсe #XX -- [ Pg.522 , Pg.525 ]




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