Principles of Modelling

This chapter will outline the main principles of modeling enzymatic reactions and leave to subsequent chapters the examination of specific enzymes and different catalytic factors. 

One of the basic principles of modelling is that of the conservation of mass. For a steady-state flow process, this can be expressed by the statement ... 

Dukler, A. E., and Y. Taitel, 1991a, Modern Measuring Methods, in Two-Phase Gas-Liquid Flow A Short Course on Principles of Modelling Gas-Liquid Flow and on Modem Measuring Methods, p. 115, University of Houston, Houston, TX. (3)... 

Chapter 2 introduces the essential principles of modeling and simulation and their relation to design from a systems point of view. It classifies systems based on system theory in a most general and compact form. This chapter also introduces the basic principles of nonlinearity and its associated multiplicity and bifurcation phenomena. More on this, the main subject of the book, is contained in Appendix 2 and the subsequent chapters. 

This is a heterogeneous system formed of two phases. For general principles of modeling heterogeneous systems, we refer to Chapter 6. 

Basic Principles of Model-Based Fault Diagnosis... 

Lumping constituents is clearly necessary when the reactant mixture is of such a complexity that it can only be characterized, for practical (e.g. analytical) reasons, by global properties that is notably the case for the pyrolysis of gas oils and crude oils. Examples of lumped constituent models can be found in refs. 35 and 36. In what follows, a few typical models will be briefly described, to bring to light the underlying principles of model building. 

Some particular aspects of mixing systems should be considered in relation to the general principles of model theory. First, if a general correlation is to be used for scale-up, it must be certain that the variables used in the correlation are the only ones acting in the given situation. Because of the complexity of mixing systems, we often lack... 

The starting-point and basic-level principles of models, which can be defined as comprehensive or inclusive, must be the following the combinatorial approach for the compilation of a kinetic scheme and the use of independent values of kinetic parameters. The latter means the flat refusal to use any parameter optimization algorithms based on adjustment of the whole model or its blocks to some selected experimental data. These two basic principles are already discussed above in Sections II.A and II.B with reference to the GRI-Mech (combinatorial approach) and the methane-to-methanol oxidation model developed by Vedeneev and co-authors (use of independent kinetic parameters). However, we could not find any example of consistent employment of both principles in conjunction. 

If we accept the prohibition of varying or adjustment of rate constants as a ruling principle of model development, this opens the prospect for using the joint Ci C2 description as a basis for an expansion on some different areas. One... 

The general principles of modeling a vapor-phase reaction on a solid catalyst in a fixed-bed reactor are illustrated by applying them to the specific case of nitrobenzene reduction to aniline. Several models of varying complexity are discussed. 

Principles of Modeling Pesticide Movement in the Unsaturated Zone... 

The basic principles of modeling the physical, chemical and biological processes that determine pesticide fate in unsaturated soil are reviewed. The mathematical approaches taken to integrate diffusion, convection, sorption, degradation and volatilization are presented. Deterministic and stochastic models formulated to describe these processes in a soil-water pesticide system are contrasted and evaluated. The use of pesticide models for research or management purposes dictates the degree of resolution with thich these processes are modeled. 

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