Migration Modeling

Fig. 5.20. The shock-induced polarization of a range of ionic crystals is shown at a compression of about 30%. This maximum value is well correlated with cation radius, dielectric constant, and a factor thought to represent dielectric strength. A mechanically induced point defect generation and migration model is preferred for the effect (after Davison and Graham [79D01]).

As an alternative to potential step experiments, current steps have also been used.163,166,167 Again, small-amplitude experiments are preferable,163 and a migration model should be used for data analysis.167... 

Williams, B.A. and Vigh, G., Dry look at the CHARM (charged resolving agent migration) model of enantiomer separations by capillary electrophoresis,. Chromatogr. A, 777, 295, 1997. 

Wei JZ (2003) A multi-factor, credit migration model for sovereign and corporate debts. J Int Money Finance 22 709-735... 

Baner, A., Brandsch J. Franz, R. and Pringer, O. (1996). The application of a predictive migration model for evaluating the compliance of plastic materials with European food regulations. Food Addit. Contain., 13, 5, 587-601. 

Two mathematical models for sintering mechanisms for supported metals have been put forward (1) a particle migration model where particles migrate over the surface of the support, collide and fuse, causing loss in dispersion (e.g. Ruckenstein et al 1984) and (2) an atomic migration model involving the... 

This chapter summarizes the book with special emphasis on the future of migration modeling procedures for polyolefins and non-polyolefins in mono- and multilayer structures combined with modern analytical methods for measuring mass transfer in new polymer-migrant systems. 

Vice versa, migration models allow a back calculation to maximum permissible contaminant concentrations in recycled PET bottle starting with the FDA prescribed migration upper limit of 0.01 ppm (10 ppb) in the foodstuff. Table 10-10 shows the calculated situation for three of the model contaminants used, based on the above mentioned diffusion model. 

Using migration modeling to estimate exposure to components of food packaging... 

The text of this clause is yet provisional and will be improved later. To develop and validate a migration estimation model for the above purpose, the Commission approved a project entitled Evaluation of Migration Models to be Used under Directive 90/128/EEC . A final objective of this project is a proposal of a validated migration model to the European Committee of Standards (CEN) for standardization. 

The following discussion summarizes the current state of knowledge regarding migration modeling. 

Migration modeling with new polymer-migrant systems... 

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