Topic relationship classification

Three criteria are useful when assessing topic relationships, namely (a) the molecular environment, (b) symmetry considerations, and (c) the substitution criterion. When two topic groups in a molecule have stereoisomeric environments, the molecule is said to possess elements of prostereoisomerism. Mislow and Raban have given a definitive classification of topic relationships [62], and the following discussion is based on this classification. 

The complete classification of the different types of selectivity is given in Figure 11.7. Such a classification enables one to specify the type of situselectivity at the level of detail needed or desired. At the simplest level, a process at a molecular site is selective (situselective), nonselective (situnonselective), or aselective (situaselective). If situselective, a process is either stereosituselective or nonstereosituselective. At the next level, one may specify the topic relationship between the sites - enantiosituselective vs. diastereosituselective, or astereosituselective vs. nonequisituselective. The next level of detail specifies the type of site... 

In retrospect, it was a consistent and logical step for Seebach and Prelog to propose, in 1982 2 a reactant-based descriptor system (SP system) corresponding to the Izumi -Tai classification. The SP system makes use of the familiar Re Si system already discussed (see Section 1.1.2.2.). Again, relative configurational relationships must be incorporated, something which the SP system does by straightforward combination of descriptors into Ikjul pairs (relative topicities) (see Section 1.1.2.2. and 1.1.4.). 

As the uses of toxicological-based quantitative structure-activity relationships (QSARs) move into the arenas of priority setting, risk assessment, and chemical classification and labeling the demands for a better understanding of the foundations of these QSARs are increasing. Specifically, issues of quality, transparency, domain identification, and validation have been recognized as topics of particular interest (Schultz and Cronin, 2003). 

A scheme analogous to the upper part of Fig. 2 has been presented for topic and morphic relationships [18,20], Thus, fragments of the same atomic composition may be homotopic or heterotopic, depending on whether they are superimposable or not. If the latter have the same constitution, they are stereoheterotopic, in the other case they are constitutionally heterotopic. Stereoheterotopic fragments are enantiotopic or diastereotopic. Morphic analysis yields the corresponding classification (see [19]). 

As intensive studies on the ECPs have been carried out for almost 30 years, a vast knowledge of the methods of preparation and the physico-chemical properties of these materials has accumulated [5-17]. The electrochemistry ofthe ECPs has been systematically and repeatedly reviewed, covering many different and important topics such as electrosynthesis, the elucidation of mechanisms and kinetics of the doping processes in ECPs, the establishment and utilization of structure-property relationships, as well as a great variety of their applications as novel electrochemical systems, and so forth [18-23]. In this chapter, a classification is proposed for electroactive polymers and ion-insertion inorganic hosts, emphasizing the unique feature of ECPs as mixed electronic-ionic conductors. The analysis of thermodynamic and kinetic properties of ECP electrodes presented here is based on a combined consideration of the potential-dependent differential capacitance of the electrode, chemical diffusion coefficients, and the partial conductivities of related electronic and ionic charge carriers. 

Geotechnical topics covered during the first cycle include soil formation, phase relationships, soil classification, principle of effective stress, seepage, consolidation, shear strength, drained and undrained conditions, essentials of Eurocode 7, retaining walls, shallow foundations, slope stability, and field investigations. There are three class hours of lectures and two class hours of exercises per week, within a semester consisting of 15 weeks. With this list of topics, basic soil mechanics principles escape students, who attend... 

The description and classification of perfumes is a study in itself, as is the important relationship between odor and color. Most major fragrance houses have their own views on these important topics, but an excellent book which gives general insights into many of these creative aspects of perfumery remains that by Wells and Billot [5] a recent volume from Calkin and Jellinek reveals much of modem perfumery [6]. 

Dust formation is a relatively common occurrence in novae, and one for which the general physical mechanism is reasonably clear (see, e.g., Gehrz 1988). Nevertheless, the relationship of dust formation to other properties of novae, or to their classification in schemes such as those of Williams et al 1992, remains a largely unexplored topic. 

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