Role of Computer Modeling

Several types of computer models have been developed for estimating the expected concentrations of the chemicals of interest as they move away from the source. Soil transport models attempt to estimate the expected concentration at the surface above buried sources. Plume transport models attempt to estimate the concentrations within a plume, along with its shape and position. A different form of model is designed to guide a search pattern for employing a sensing system to trace a plume. 

16Recall that the term seafloor in this work designates the soil of the bottom of any body of water, whether sea, lake, pond, river, stream, or irrigated field. 

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J. Bertran, Molecular Aspects of Biotechnology Computational Models and Theories, Proceedings of the NATO Advanced Research Workshop on The Role of Computational Models and Theories in Biotechnology, Sant Feliu de Guixols, Spain, June 13-19, 1991, in NATO ASI Series, Ser. C., Vol. 368, Kluwer, Dordrecht, 1992. 

The role of computer modelling in the science of complex solids including microporous materials was surveyed in Faraday Discussion 106 held in 1997. These techniques have now an increasingly predictive role. They can, for example, predict new microporous structures, design templates for their synthesis and model the static and dynamical behaviour of sorbed molecules within their pores,a topic of enduring importance and one of particular interest to Barrer. Computer modelling methods are, of course, most effective when used in a complementary manner with other physical techniques. Ref. 6 nicely illustrates this theme. Here EXAFS and quantum mechanical methods are used in a concerted manner to elucidate the structure of the active site in microporous titanosilicate catalysts. Articles in Faraday Discussions, vol. 106 again illustrate the complementarity of computational and experimental techniques. 

In a recent account, Radhakrishnan has discussed molecular structure, symmetry, and shape as the design elements in the fabrication of molecular crystals for second harmonic generation and has highlighted the role of computational modeling. 

The development of quantitative theories to explain the observed thermomechanical behavior of rubber-like solids in terms of their molecular structure had its beginnings over fifty years ago and remains an active area of research. In this paper we describe, in brief outline, the role of computer modelling as a technique for testing aspects of these theories details of the procedures will be found elsewhere (see Gao and Weiner [2], [3] and [4]). 

Thermodynamic properties such as heats of reaction and heats of formation can be computed mote rehably by ab initio theory than by semiempirical MO methods (55). However, the Hterature of the method appropriate to the study should be carefully checked before a technique is selected. Finally, the role of computer graphics in evaluating quantum mechanical properties should not be overlooked. As seen in Figures 2—6, significant information can be conveyed with stick models or various surfaces with charge properties mapped onto them. Additionally, information about orbitals, such as the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO), which ate important sites of reactivity in electrophilic and nucleophilic reactions, can be plotted readily. Figure 7 shows representations of the HOMO and LUMO, respectively, for the antiulcer dmg Zantac. 

From this perspective, and with a continued lack of models and a better understanding of enantioseparation mechanisms, we can assume that the role of computers in this field will become increasingly determinant. 

The Supporting Role of Molecular Modelling and Computational Chemistry in Polymer Analysis... 

Mathematical methods as tools for data treatment also encompassing the role of computers in handling, analysing and modelling the vast sources of data. 

Jorgensen, W. L. 2004. The Many Roles of Computation in Drug Discovery , Science, 303, 1813. Leach, A. R. 2001. Molecular Modelling, 2nd Edn., Prentice Hall London. 

S. Elnashaie, F. Alhabdin, S. Elshishini, The vital role of mathematical modelling in chemical engineering education, Math Comput Modelling, 17 (1993), p. 3-11... 

In anticipation of future requirements and resources, it is reasonable to expect that mechanistic models may very well be able to communicate directly with global models or take on the role of process models. With the advent of increasingly sophisticated serial computers and an advanced understanding of the paradigm of parallel computing, it is reasonable to extrapolate today s advances to the year 2000 where mechanistic models may well provide all three levels (mechanistic, molecular, and global) of product information. 

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