Theoretical Understanding of the Problem

Recently, the notion of preexisting protein conformations was used to rationalize binding events based on the concept of folding funnels [22, 23]. According to this theory, the native state of the protein may not be represented by a single conformation. 

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It should be emphasized that particularly for these merits the quasiclas-sical (or semiclassical) methods of detailed chemical kinetics have become a basis for the present theoretical understanding of the problems of chemical reactivity. 

Despite these problems and limitations, calculations of chromatic differences by formula has proved useful, automated colorimeters for doing so exist, and the practice may be regarded as established, perhaps more firmly than it should be. Room for improvement at a practical level and for a better theoretical understanding of the problem certainly exists. 

Other, often made distinction in types of research, are between exploration, description, explanation, and testing, van der Zwaan (Zwaan van der, 1990). Exploration is conducted when theoretical knowledge in literature lacks information on which variables are important. Description types of research aim at the relevance of the variables. Explanation types of research aim at identifying the causal links between variables and phenomena. Finally, testing types of research aim at proving the hypotheses derived from the causal links. The research project discussed in this thesis is mainly explorative in nature. The emphasis is to design concepts and a protocol, which increases the understanding of the problem of how and why accidents continue to occur in companies in the chemical process industry. In this way a contribution to the solution of the problem will be made and consequently this research can be typified as applied positivistic exploratory research. 

These examples of simulations of the molecular dynamics of carbohydrates show the possibility of predicting their behavior in different solvents. Experimental work has confirmed these findings. While theoretical prediction is becoming more reliable, it is only qualitative and we must consider the theoretical results within the framework of the actual capability of the methods. Current minicomputers allow simulation of large system. Polysaccharides, for instance, are being studied by this technique. However, the description of carbohydrate solutions is still poor, and simple systems can help in the understanding of the problems. 

Another of our present aims is to continue investigating the theoretical properties of the 2- and 3-body terms. Thus, there are many exact relations linking the different 3-body terms arising from each of the 36 options of equation (9) as well as their holes counterparts [16]. These relations are interesting by themselves, because they widen our understanding of the problem and may be helpful for improving our approximations. Another important theoretical question is, as mentioned above, to investigate the reason why one Ai corrects the VCP error which in some cases is only due to the 3-body contribution but which may also involve other kind of correlation effects. 

There were still problems, however. Physicists had never succeeded in gaining a good theoretical understanding of the so-called strong force, the force that held protons and neutrons together in nuclei. They had devised various approximations that described this force but none was entirely accurate. It was now apparent why they had failed. The strong force was actually the result of forces between quarks inside protons and neutrons. No one yet knew what these forces were, but there was every reason to think that their nature would sooner or later be discovered. 

We saw above that the study of the competition between Fe3+ and H + reduction on illuminated p-GaP led to an increased understanding of the nature of surface electrochemical processes on that material. For many n-type materials, however, the most serious competing reaction with the oxidation of some redox couple in solution is the oxidative corrosion of the semiconductor itself. This has considerable practical consequencies a photoelectrochemical device for the conversion of solar energy must be one in which the desired electrochemical route is overwhelmingly probable compared with semiconductor dissolution. So essential is this requirement, and so difficult has it proved to find satisfactory solutions for n-type semiconductors, that a substantial fraction of the recent literature on semiconductor electrochemistry has been devoted to both practical and theoretical considerations of the problem. 

The key to understanding the occurrence of these rotating waves lies in the interplay of the shift in potential of the counter-electrode when the active area increases, and the radial dependence of the IR drop between the reference electrode and different positions of the working electrode. However, a complete explanation of the phenomenon has to await the results of the theoretical treatment of the problem currently being investigated by Christoph et al ... 

A number of organic polymers become electrically conducting on addition of electron donors or acceptors.(1-5) Despite the enormous interest in these conducting polymer systems, many theoretical aspects of the problem remain poorly understood, especially with regard to the electronic properties of the "doped" (partially ionized) polymers. Progress is being made, however, in understanding the undoped polymer precursors. In a series of recent papers, we have demonstrated the utility of the... 

Density functional techniques are available for the calculation of the molecular and electronic structures of ground state systems. Techniques of this kind are also applied extensively in the study of classical liquids, where applications cover a broad spectrum ranging from fluids at interfaces to theories of freezing and nucleation. The area of nuclear physics is still in a very early stage of development in the use of DFT, mainly because there is not yet a complete theory, as there is in the molecular and atomic cases. This chapter has focused on the theoretical aspects of other applications not related to the use of the Kohn-Sham procedure for electronic systems, with the hope that a better understanding of the problems and successes in the respective areas would help in the development of improved functionals. 

While I will admit to some parametric observations where no specific theoretical background could be estabUshed right away, we are basically using an analytic approach that not only leads to a clear understanding of the problems but also establishes whether solutions exist and what they are. 

The chapters can be divided into two parts Chapters 1-9 deal mostly with gas-solid adsorption and Chapters 10-15 deal with liquid-solid adsorption. Chapter 2 discusses the gas-solid adsorption on heterogeneous surfaces and provides an excellent and up-to-date overview of the recent literature, giving new results and aspects for a better and deeper understanding of the problem in question. The same statements are valid for Chapters 4-7. In Chapters 8 and 9, the problems of adsorption kinetics, using quite different methods, are discussed however, these methods are successfrd from both a theoretical and a practical point of view. The Uquid-solid adsorption discussed in Chapters 10-15 can be regarded as developments and/or continuations of Everett s and Shay s work done in the 1960s and 1970s. 

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