Neglect, severe

Most of the present implementations of the CPA on the ab-initio level, both for bulk and surface cases, assume a lattice occupied by atoms with equal radii of Wigner-Seitz (or muffin-tin) spheres. The effect of charge transfer which can seriously influence the alloy energetics is often neglected. Several methods were proposed to account for charge transfer effects in bulk alloys, e.g., the so-called correlated CPA , or the screened-impurity model . The application of these methods to alloy surfaces seems to be rather complicated. 

Development of this model has neglected several substances that in principle possibly could have been included. The most obvious omissions are dissolved phosphate released by the decomposition of organic matter and the possible dissolution or precipitation of CaC03. Both of these substances would affect the pH profile. The effect of phosphate on pH would probably be small because its concentration in organic matter is low compared to N and C. The effect of CaC03 on pH however could be important and thus application of the model should probably be restricted to CaC03 free sediments. 

Because of the vast quantity of published ET research, we have had to neglect several important areas of current interest. Many investigators have built systems to try to mimic the first steps of photosynthesis as well as the low-temperature (4.2 K) ET seen in photosynthetic reaction centers. Efficient ET has been observed down to 10 K in certain complexes (19, 184), and studies of ET across membranes using model systems have been made (59, 135, 137, 167). A relatively new area related to photosynthctic charge separation encompasses the study of ET in polymers that have been func-... 

Because the Reeves-Kelly scheme neglects several important non-bonded interactions, such as those between syn-diaxial hydroxyl groups and vicinal, gauche substituents, and because polar interactions are neglected altogether, the scheme may, at best, be considered to represent a qualitative attempt to predict the conformational behavior of pyranoid sugars in solution. 

This review concentrates on characterization of the actual pore space, and transport within the pore space, using NMR methods. Thus, it neglects several areas. For instance the adsorption properties of a porous solid are of considerable interest in the fields of gas separation and catalysis. Adsorption and catalytic properties depend critically on the surface chemistry of the solid phase, and NMR studies of this topic have been widely reviewed elsewhere. " We shall, however, consider NMR studies of adsorbates when they specifically give information on the pore space. 

Pressure and vapor phase composition being often chosen as dependent variables, the errors in temperature and liquid phase composition are neglected. Several objective functions based on these assumptions were suggested and studied by Van Ness, Pedersen and Rasmussen (78VAN1), e. g. 

Fig. 31. Phonon dispersion curves for CcPds al room temperature. Solid symbols are longitudinal modes, open symbols transverse modes. In the [110] direction A, transverse polarized in (110) plane O, transverse polarized in (100) plane. Results of Born-von Karman fit including breathing term are shown as solid and dashed lines (the latter for A data points). Dotted lines if breathing term is neglected (Severing el al. 1988).

If the baseline shift or the change of sensitivity detected by two consecutive zero/standard samples caimot be neglected, several compensation methods may be applied. Figure 10-27 shows a record of ten CFA samples in steady-state mode preceded and followed by zero/ standard sequences. Both, baseline and sensitivity, differ considerably between the first and the final zero/standard sequence. 

The extrapolation of friction coefficient results, from twin disk machine tests to gears, neglects several inqmrtant aspects that contribute to the discrepancies found ... 

The classical theory accounts only for electrostatics and thermal motion and neglects several important effects such as dispersion forces. 

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