Chemical and structural characteristics

Smith PA, Sorich MJ, McKinnon RA, Miners JO. In silico insights chemical and structural characteristics associated with uridine diphosphate-glucuronosyltransferase substrate selectivity. Clin Exp Pharmacol Physiol 2003 30 836-40. 

The absorption and emission spectra of Ru(bpy) + also showed pronounced spectral shifts (compared to that in water) upon intercalating into a sulfonated derivative of layered a-ZrP, zirconium sulfophenylphosphonate, or ZrPS [84], The XRD and the infrared (IR) spectra of the mixture, on the other hand, indicated that the chemical and structural characteristics of the complex were not significantly affected by the host matrix. The diffuse reflectance spectra, however, revealed three important differences from that observed in aqueous solution. These are that (1) the tt-tt band was strongly red-shifted to 317-320 nm from that observed at 285 nm in aqueous solution, (2) the MLCT band also red-shifted, depending on the loading, from 462 to 494 nm, and (c) the ratio of the intensity of the tt-tt band to the MLCT band decreased with loading (Fig. 40). 

The nature of an interface (liquid/liquid, solid/liquid, air/liquid and so on) should reflect on the relevant interfacial phenomena, so that detailed understandings of chemical and structural characteristics of the interface at a microscopic level are of primary importance for further advances in various sciences. In practice, solid/liquid and air/liquid interfacial systems have been studied widely by various experimental techniques, and the knowledges about the characteristics of the interfaces have been accumulated. However, very little is known about the chemical and structural characteristics of a liquid/liquid interface at a microscopic level. So far, thermodynamic and electrochemical techniques have been applied to study liquid/liquid interfacial chemistry. Nonetheless, its dynamic aspects have rarely been explored. 

In this chapter, we review recent results on the studies of chemical and structural characteristics at water/oil interfaces with special references to those at water/CCU and water/l,2-dichloroethane (DCE) interfaces. 

It is unfortunate that in the published catalytic studies with heat-treated NH4-exchanged Y the catalyst substrate seems to be insufficiently characterized, and the assignment of structural details, which are most important for catalytic properties, are based on assumptions, usually drawn from comparisons with similar zeolite samples. Furthermore, the catalytic properties of zeolites which are more fully characterized usually are not reported in the literature. Consequently, comparison between catalysts prepared by different investigators is very difficult and risky since the catalytically important details depend on several chemical and structural characteristics, all of which usually are not described. As an example of this problem, the dehydroxylation of heat-treated NH4" -exchanged Y depends on the temperature, atmosphere, and time employed on activation, as well as on the Si/Al ratio, the degree of NH4" exchange 16), and the residual cations 108). 

Uniform active sites on the catalyst. Today, in industrial catalysis using solid inorganic catalysts, "uniform active sites" are only a dream. The active sites in both oxide and metal catalysts represent a wide, often extremely wide, range of chemical and structural characteristics. Consequently, the chosen process conditions are optimized to the average active site characteristics. The result is that a fi action of the active sites will be ineffective and another will show less than optimum selectivity. Any presently used commercial catalyst, if it could be prepared with uniform or at least nearly uniform active sites, would allow further process and performance optimization. 

ACCUGLASS 203 and 305, were Investigated. It is shown that SOG films of 2-3000A thickness yield adequate smoothing of one micron high features and that their material and processing characteristics are compatible with IC processes. The chemical and structural characteristics of SOG 203 were further studied with a variety of spectroscopic techniques. The SOG/silicon interface was found to be structurally similar to that between thermal Si02 and silicon. 

Dias, J.R. 1992b. Deciphering the Information Content of Chemical Formulas Chemical and Structural Characteristics and Enumeration of Indacenes. Journal of Chemical Information Computer Science 32 203-209. 

Organic matter is present in water, soil, air particulates, and waste materials as a conglomeration of carbonaceous chemical by-products of living and decaying plant and animal matter. Several factors control the range and types of chemical and structural characteristics of the... 

This assumption also follows from the group contribution method used to compute 8 from the chemical and structural characteristics of polymeric chain [Grulke, 1989 van JCrevelen, 1992]. 

Fig. 2.40. Variations of physical-chemical and structural characteristics of fiim materials based on PE as a function of mineral oil content (1) elasticity moduius (E), (II and III) crystallinity degree (D731 and Diaes - optical density of absorption bands at 731 and 1368 cm frequencies in IR spectra of the materials S - melting peak areas on thermograms)...

Recently we found (Sakurai, Urabe, and Izumi 1988 1989) that interlayer La cations were irreversibly fixed by heating onto the exchange sites of silicate layer in TSM, and the fixed La ions gave the pillared TSM a strong acidity. The resultant La -modified pillared TSM possesses, in principle, all of the La ions, or acid sites only on the silicate surfaces but not on the pillars. Here, we have extended the type of modifying cation and host layered clay, respectively, to various cations and clays other than TSM, and report on their chemical and structural characteristics with respect to catalytic performances (Sakurai, Urabe, and Izumi 1990 1991). 

Animals are not capable of de novo synthesis of vitamin A-active substances, neither preformed retinol and its derivatives nor the carotenoid precursor forms. The preformed retinoids are defined and their chemical and structural characteristics are given in other chapters in this volume and in the appendix. 

Figure 5 The classification of the elements produced with nonnormalized physical, chemical and structural characteristics (from Ref. 32).

The classification hierarchy produced with the use of 10 physical, chemical, and structural characteristics is presented in Figure 8. 

The first partitioning in classes 1 and 2 is the same as in the nonnorma-lized classification on the basis of 10 physical, chemical, and structural characteristics, except for aluminum, which is classified with the main group elements Tm and Cu are near the boundary between classes. All the characteristics, except the boiling point, are assigned to this class only the melting point has a lower MD, being at the limit of the class. 

A relatively large number of chemical and structural characteristics affect the properties and behaviors of polymeric materials. Some of these influences are as follows ... 

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