Selection, concept

Bajorath J (2001) Selected concepts and investigations in compound classification, molecular descriptor analysis and virtual screening. J Chem Inf Comput Sci 41 233... 

Example for demonstration The example shall demonstrate that a data base comprising activity data from hydrogenation of mono-functional substrates allows a preselection of potential catalysts for hydrogenation of multifunctional substrates. Based on this pre-selection concept the process of identifying the optimal precious metal powder catalysts is accelerated. 

Development is usually done in several phases. Each phase can have any number of steps. In the course we mn we assume four phases a first one in which a firm orients itself and plans which products it will develop, a second one in which a core team forms concepts and plans the project, a third one in which the core team develops the selected concept to a product with its manufacturing and market, and a final phase in which the product is exploited (Figure 3-1). Each of these phases is a learning cycle for the firm, but there will be many sub-cycles in each. The subdivision into four phases is arbitrary a complex project may need more phases. Regulations may force one to use more phases. 

Final selected concept models as best solution... 

The discussion of a number of topics in electrocatalysis, including adsorption phenomena, surface reaction mechanisms and investigation techniques, electrocatalytic activity and selectivity concepts, and reaction engineering factors, may seem at first too diverse. We believe, however, that fundamental principles cannot be divorced from their natural counterpart, praxis. Here, we attempt to establish ties between basic and applied electrocatalysis and with their conventional similes, catalysis, surface physics (and spectroscopy) and reaction engineering. By taking a vitae parallelae perspective, we hope that a synthetic analysis of the present state of the art emerges. 

DeBoef and co-workers have reported a similar reaction, wherein direct C-H to C-H indole-arene cross-coupling can be controlled through the use of a particular oxidant (Scheme 34) [53,54], The basis of their selectivity concept is the formation of different polyvalent clusters between the Pd(OAc)2 and the AgOAc or Cu(0 Ac)2 oxidants respectively, and the subsequent reactivity of these complex in the aryla-tion reaction. The same group also demonstrated the utility of an intermolecular C-H to C-H coupling reaction. 

Refine and optimize the selected concept(s) using DFMA techniques. 

Figure 5.4 A schematic illustration of the shape selectivity concept, classically referring to a significant modification in the distribution of products in a catalytic reaction due to the localisation of the active sites within a confined space of the catalyst. Reactant shape selectivity (a) occurs when some but not all the components in a reaction mixture can reach the inner active sites and react. When the size and shape of the inner void modify the distribution of products by limiting the number of possible transition states, the effect is called transition state shape selectivity (b). And, finally, when a molecule can be formed but cannot be desorbed due to its size and shape, the product distribution is altered by product shape selectivity (c). In addition to these broad concepts, thermodynamic effects are also of importance. Reproduced by permission from Macmillan Publishers Ltd Nature, B. Smit and T.L.M. Maesen, 451, 671 (20). Copyright (2008) Macmillan Publishers Ltd.

Step 3. Select concept. Innovative concepts for the new design are generated, first by brainstorming. These are evaluated, with the best selected for further development. 

Nevertheless, there has been re-evaluation of the selected concepts. Due to the more stringent regulatory requirements adopted for shallow land disposal in some countries in the 1980 s, the modem concepts provide much better isolation by means of engineered barriers than diose introduced a few decades ago. 

Swedish bedrock. However, it was also concluded that much additional research and development work were needed before the KBS concept could be realized. The view that the KBS concept can be used as the main alternative in the industry s R D programme has been reconfirmed in the later reviews of Swedish and Finnish spent fuel disposal programmes [1,2]. It is also clear that before starting to construct the actual facilities, the safety of the selected concept and of its viable alternatives will be thoroughly evaluated. 

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