Models Wilson

Wilms tumor Wilson model Wilson plots Wilson s disease Wilson s equation... 

This, the Wilson model, is more complex than the Van Laar model, but it does retain the two-parameter feature. The terminal activity coefficients are related to the parameters ... 

Whereas the Wilson model has been found to represent a wide variety of nonideal VLE, it caimot handle the case of partial immiscihility of the Hquid phase for this purpose a three-parameter relationship, the nonrandom, two-Hquid (NRTL) model was developed (20). 

Table 37.3 shows the complete table of eight indicator variables for 10 triply substituted tetracyclines [31 ] that have been tested for bacteriostatic activity (1/Z), which is defined here as the ratio of the number of colonies grown with a substituted and with the unsubstituted tetracycline. In this application we have three substitution positions, labelled U, V and W. The number of substituents at the three sites equals 2,3 and 3, respectively. Arbitrarily, we chose the compound with substituents H, NOj and NO2 at the sites U, V and W as the reference compound. This leads to a reduction of the number of indicator variables from eight to five, as shown in Table 37.4. The solution of the Free-Wilson model can be obtained directly by means of multiple regression ...

Principal components analysis can also be used in the case when the compounds are characterized by multiple activities instead of a single one, as required by the Hansch or Free-Wilson models. This leads to the multivariate bioassay analysis which has been developed by Mager [9]. By way of illustration we consider the physicochemical and biological data reported by Schmutz [41] on six oxazepines... 

Williamson ether synthesis, 10 574 Williamson flow model, 21 705 Wilson s disease, 7 710 Wilson model, for VLE, 8 745 Wilsonville Coal-Liquefaction facility, 6 766, 841-844 Winch dyeing, 9 208 Wind energy... 

Kubinyi, H., Kehrhahn, . H. (1976) Quantitative structure-activity relationships. 3. A comparison of different Free-Wilson models. JMed Chem 19(8), 1040-1049. 

Firstly, we will examine the VLE of binary mixtures. The Wilson model is selected for liquid activity with Redlich-Kwong EOS for vapor phase. The predictions offered by Aspen Plus [9] are in agreement with experimental data [5], except... 

X + x2G21 = 1.509, andx2 +x1G12 = 1.022. Substituting into the Wilson model,... 

Related Calculations. When the Wilson model is used for systems with more than two components, it is important to remember that the Gjj summations must be made over every possible pair of components (also, remember that Gj j Gjj ). 

The Free-Wilson model (also called additivity model) is defined as ... 

The Fujita-Ban model is a linear transformation of the classical Free-Wilson model indeed, group contributions of the Free-Wilson model can be transformed to Fujita-Ban group contributions by subtracting the group contributions of the corresponding substituents of the reference compound. 

Free-Wilson model Free-Wilson analysis... 

In regard to the representation of biological activity in the various Free-Wilson models there has been discussion (221,... 

Wilson s equation of state is found from Equations (14) and (15). It can be seen that for obtaining the activity coefficient of a component 1 in a pure solvent 2, we need four interaction parameters (A12, A21, An a A22, which are temperature dependent. It is evident that for calculating the value of the binary interaction parameters, additional experimental data, such as molar volume is needed. Other models which belong to the first category have the same limitations as Wilson s method. The Wilson model was used in the prediction of various hydrocarbons in water in pure form and mixed with other solvents by Matsuda et al. [11], In order to estimate the pure properties of the species, the Tassios method [12] with DECHEMA VLE handbook [13] were used. Matsuda et al. also took some assumptions in the estimation of binary interactions (because of the lack of data) that resulted in some deviations from the experimental data. 

Migliorini et al. [65] used both the IAS and the RAS theory to accoimt for the experimental binary competitive isotherm data of the Troger s base enantiomers on microcrystalline triacetate cellulose (CTA), using ethanol as the solvent. For the calculations of the RAS theory, they used the Wilson model for the solution, including the empirical spreading pressure dependence [66]. They concluded that the IAS model imderestimates the extent of the competition between the two enantiomers in this system while the RAS model accormts accurately for the complex competitive adsorption behavior exhibited by these enantiomers. 

Once the interaction energies were obtained, they were used to calculate the parameters in the UNIQUAC and Wilson models given by Eq. (24). To test the validity of the method, low-pressure vapor-liquid equilibrium (VLE) predictions were made for several binary aqueous systems. The calculations were done using the usual method assuming an ideal vapor phase (Sandler, 1999). Figures 7 and 8 show the low-pressure VLE diagrams for the binary aqueous mixtures of ethanol and acetone [see Sum and Sandler (1999a,b) for results for additional systems and values of the... 

The vapor-liquid equilibria of this system was represented by the Wilson model for the activity coefficients and the Antoine equation for the vapor pressures. The binary Wilson model parameters are (quoted by Biddulph and Kalbassi). 

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