Modelling and kinetics

Liu J, Ericksen SS, Besspiata D et al (2003) Characterization of substrate binding to cytochrome P450 1A1 using molecular modeling and kinetic analyses case of residue 382. Drug Metab Dispos 31 412 -20... 

Figure 23.9 illustrates the model and kinetics scheme for these conditions. We confine our analysis to a single first-order reaction, based on the development of Kunii and Levenspiel (1990 1991, pp. 300-302). However, extension to other reaction orders is straightforward. 

In addition, modeling and kinetic studies of iron nanoparticle synthesis from gas-phase Fe(CO)s have recently been reported [78, 79]. 

The type of quantitative analytical data which are needed for modelling and kinetic studies on coal liquefaction process could not be obtained by using general analytical techniques. We have developed a new analytical approach for obtaining qualitative information as well as quantitative data on coal liquid species. Coal liquefaction produces smaller molecules from coal which is composed of larger molecular species or a matrix of larger molecular species in which smaller species are entrapped. 

Oxygen incorporation at low pressures was simulated using a simple transport-kinetics model, and kinetic parameters were determined. Results of the transport-... 

M. Biehl, Lattice gas models and kinetic Monte Carlo simulations of expitaxial growth. http //arXiv.org/, paperno. cond-mat/0406707, 2004. 

Before discussing the chemical dynamics of estuarine systems it is important to briefly review some of the basic principles of thermodynamic or equilibrium models and kinetics that are relevant to upcoming discussions in aquatic chemistry. Similarly, the fundamental properties of freshwater and seawater are discussed because of the importance of salinity gradients and their effects on estuarine chemistry. 

Most, if not all, solutions of the nozzle expansion problem have used equilibrium composition chamber conditions as the initial condition for nozzle solution. The feature is common to all of the nozzle flow solutions that is, the equilibrium composition expansion, frozen composition expansion, Bray freezing model, and kinetic rate solutions have all invoked the assumption of equilibrium composition at the beginning of the expansion process. While the failure to obtain equilibrium composition predicted performance, in terms of experimental characteristic velocities, has suggested a departure from equilibrium in the combustion chamber, only recently have non-equilibrium compositions been measured directly (31). 

In theory, by feeding the MWD and experimental rate data into a mathematical model containing a variety of polymerization mechanisms, it should be possible to find the mechanism which explains all the experimental phenomena and to evaluate any unknown rate constants. As pointed out by Zeman (58), as long as there are more independent experimental observations than rate parameters, the solution should, in principle, be unique. This approach involves critical problems in choice of experiments and in experimental as well as computational techniques. We are not aware of its having yet been successfully employed. The converse— namely, predicting MWD from different reactor types on the basis of mathematical models and kinetic data—has been successfully demonstrated, however, as discussed above. The recent series of interesting papers by Hamielec et al. is a case in point. 

Weekman, V. W., Lumps, models and kinetics in practice. Chem. Eng. Prog. Monog. Ser. 75(11), 3... 

The inclusion of reactions to represent the low-temperature chemistry in a detailed model for n-butane oxidation at high pressures, that is appropriate to temperatures down to about 600 K began in 1986 [225]. At the present time, models which include around 500 species and more than 2000 reversible reactions to represent alkane isomers up to heptane, are in use [219] and still larger schemes are under development [220]. Progress in the validation and application of these models, and kinetic representations for propane and propene oxidation, are discussed in the next subsection. Modelling of the low-temperature combustion of ethene has also been undertaken more recently [20]. 

Natural waters obtain their equilibrium composition through a variety of chemical reactions and physicochemical processes. In this chapter we consider principles and applications of two alternative models for natural water systems thermodynamic models and kinetic models. Thermodynamic, or equilibrium, models for natural waters have been developed more extensively than kinetic models. They are simpler in that they require less information, but they are nevertheless powerful when applied within their proper limits. Equilibrium models for aquatic systems receive the greater attention in this book. However, kinetic interpretations are needed in description of natural waters when the assumptions of equilibrium models no longer apply. Because rates of different chemical reactions in water and sediments can differ enormously, kinetic and equilibrium are often needed in the same system. 

The basic differences between thermodynamic models and kinetic models can be exemplified by considering a single hypothetical chemical reaction... 

Although the thermal decomposition reactions of biomass have been systematically investigate for many years the biomass community is still debating the best foimal reaction model and kinetic parameters for the primary thermal decomposition. Even for... 

We have in our files about 500 published papers that report studies or contain kinetic equations of deactivation of solid catalysts of which about 50 contain kinetic equations of deactivation of the catalysts for the FCC (fluid catalytic crEicking) process. Thus, much could be said on the subjects especially since each author in the field uses his own approach and experimental technique. In addition, the literature used is different from one author to another which, in turn, makes possible a lot of different bases and approaches. Thus, for the FCC process each author and oil company lend to use their own model and kinetics, making it difficult to arrive at new approaches and optimum parameters of deactivation, especially if one is already comfonable with an approach and its corresponding parameters. 

V.W.Weekman Jr., Lumps, Model and Kinetic in Practice, AIChE monograph series (1979). 

In a word, the formation process of zeolites is very complicated. The crystallization models and kinetics equations proposed during early studies are not very meticulous. 

The authors know from their own experience how attractive and fascinating, but at the same time meaningless can be computer games with equations, software, and model modifications. Based on this, we have almost completely refrained from consideration of any mathematical aspects and computational procedures, which are indeed very important in modeling and kinetic simulations. However, these topics require separate consideration, but only when... 

Weekman, V.W., 1979, Lumps, Models and Kinetics in Practice, AlChE Monograph Series. No. II, 75. 3. 

Do and Do(1994a-c) have reported a detailed modeling and kinetic study of the electrochemical oxidation of benzyl alcohol to benzaldehyde in a continuous-stirred tank electrochemical reactor. 

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