Split-charge variables

If you are in charge of quality control laboratories in manufacturing companies, it is important to distinguish between the variability of a product and the variability of the analysis. When analyzing tablets on a pharmaceutical production line, variability in the results of an analysis has two contributions from the product itself and from the analytical procedure. Your bosses are interested in the former, and you, the analyst, must understand and control the latter. It is usually desired to use methods of analysis for which the repeatability is much less than the variability of the product, in which case the measured standard deviation can be ascribed entirely to the product. Otherwise, analysis of variance can be used to split the total variance of duplicate results into its components (chapter 2). In the discussion that follows, the emphasis is on measurement variability, but the principle is the same, and the equations and methods can be used directly to obtain information about the product or manufacturing process. 

In conclusion, over 130 semiconductors are known to catalyze the photochemical water-splitting reaction according to eq 1 or either water oxidation or reduction in the presence of sacrificial agents. Even though the principle activitycontrolling factors in semiconductor-heterostructures have been identified, many aspects of the function of inorganic photocatalysts are still unclear. Most importantly, the molecular mechanism of water reduction and oxidation on the semiconductor surface has not yet been elucidated in sufficient detail. ° Many questions about charge transfer between semiconductor and cocatalysts, and its dependence on the structural and electronic features of the interface are still open. The effect of variable material preparations and surface impurities on the catalytic activity of semiconductors (e.g. sulfur and oxide on... 

The splitting of the molecular orbitals derived from metal J valence orbitals involves a quantity that is of considerable interest when discussing the electronic structures of metal complexes. The A values for a representative selection of octahedral, square-planar, and tetrahedral complexes are given in Table 9-1. The value of A depends on a number of variables, the most important being the geometry of the complex, the nature of the ligand, the charge on the central metal ion, and the principal quantum number of the d valence orbitals. We shall discuss these variables individually. 

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