Big Chemical Encyclopedia

Chemical substances, components, reactions, process design ...

Articles Figures Tables About

Embedded calculated parameters

Although it is difficult to see in Figure 7.29, the solid line fitting function returned by datafitO essentially overlays all the experimental data points and does a very excellent job of fitting the experimental data with its approach of using local cubic functions to describe a much more complicated relationship on the global scale. The interpolation functions have been saved in this example in a table to illustrate how a series of functions can be generated each with a different set of embedded interpolation parameters for use in subsequent calculations. [Pg.292]

Based on the RIS Ansatz, the embedding algorithm benefits from a great flexibility in the choice of the input parameters that account for the local chain energy configuration the input for the correlations of torsion angles along the chain backbones can be either calculated with the help of a force field, or extracted from measurements, or even biased in order to study any thinkable structural properties of the macromolecules. [Pg.152]

Our objective has been to develop methods that allow the calculation of various electronic parameters such as partial atomic charge, q, electronegativity, polarizability, a, for each atom of a molecule. In this way, the values assigned to an atom not only reflect the type of the atom, but also the particular molecular environment into which this atom is embedded (Fig. 18). The electronic parameters assigned to the atoms of a bond will then be used to arrive at a quantitative value for this bond which reflects its reactivity. A detailed description of a reaction will also have to include parameters characteristic of the reagent in order to account for its influences on bond breakage and formation. [Pg.48]

It is clear that the g values are very sensitive to the presence or absence of hydrogen bonding to the quinone oxygens and to the hydrophobicity of the solvent surrounding or the protein pocket. Also the structure of the quinone itself plays a role.140 However, since the 0-tensor reflects only the global properties of the wavefunction it is still difficult to draw far reaching conclusions from this spectroscopic parameter. This situation will hopefully change when more reliable 0-tensor calculations, e.g. for radicals embedded in proteins, become available, e.g. on the QM/MM level. [Pg.186]

The parameter X has been embedded in the definition of Hp. The wave function from perturbation theory [equation (A.109)] is not normalized and must be renormalized. The energy of a truncated perturbation expansion [equation (A.110)] is not variational, and it may be possible to calculate energies lower than experimental. ... [Pg.244]

Lin and Yang (1987) also calculated the thermodynamic parameters of diazepam for micellar solubilization in Pluronic surfactant solutions at different temperatures (Table 13.4). For all systems, AG was negative, indicating micellar solubilization was spontaneous. The sign of entropy has been associated with the location of solubilized molecules within the micelles. Positive values have been observed for molecules embedded in the micelle center and negative values for adsorption of the molecules on the micelle surface. The results in this paper indicate that in the F-108 and F-88 Pluronics, diazepam molecules can penetrate into the micelle interior, whereas for F-68 and lower concentrations of F-88, diazepam is adsorbed on the micelle surface without penetration into the micellar core. [Pg.322]

In this dilemma of contradicting interests, COSMO-RS can be a valuable tool for the computational characterization of the solubility behavior of the drug candidate as well as of its dissociation constants. Both are of crucial interest since the small and very expensive amount of compound has to be dissolved and embedded in different solvents and environments for the various steps of purification, crystallization, analysis, and formulation. At present, empirical solubility parameter approaches are often used in order to classify and predict the solubility behavior of the new drug, but despite their poor physical foundation, they have the additional disadvantage that the experimental measurement of the solubility parameters of the new drug consumes time and compound. In contrast, the required DFT/COSMO calculations can be started before the compounds come to the development laboratory, and a COSMO-RS solubility and dissociation screening can be completed—even at optimal computational level— when the work in the development department starts. Furthermore, none of the valuable substance is wasted in this step. [Pg.169]

Work of Harding and coworkers has clearly established the value of defect entropy calculations using these methods. Moreover, we note that comparisons have been made between entropies and energies calculated using supercell and embedded crystallite techniques. It is reassuring that the techniques yield the same defect parameters for large sizes of the supercell and of the crystallite. [Pg.4535]

Equation 2.4 really is at the center of the entire way of argumentation. This equation and the c, x parameters derived to calculate it - as well as various permutations and applications - flatly provide the fundament of a quantitative understanding of the behaviour of metal ions (and, theoretically speaking also other kinds of electrophiles) in both biomass and the embedding ecosystems. By this approach selective binding to certain metal ions and their corresponding clustering can be... [Pg.23]

A simpler form of the Gaussian band shape, where a is simply treated as an adjustable parameter, is given in equation 21-5. This is the equation that will be used in the following treatment. By using an embedded chart to compare calculated and experimental data, you can fairly easily find a set of A ax/ Vmax and a values that approximate the band shape, to use as initial guesses for the deconvolution procedure outlined in the box on the following page. [Pg.345]

The monitoring uses formulas that take into account feed flow rates, targets calculated by the optimization layer of multivariable control, controlled variables upper and lower limits and other parameters. The economic benefits are based on the degrees of freedom and the active constraints at the steady state predicted by the linear model embedded in the controller. In order to improve the current monitoring, parameters dealing with process variability will be incorporated in the formulas. By doing this, it will be also possible to quantify external disturbances that affect the performance of the advanced control systems and identify regulatory control problems. [Pg.495]


See other pages where Embedded calculated parameters is mentioned: [Pg.823]    [Pg.163]    [Pg.242]    [Pg.84]    [Pg.309]    [Pg.111]    [Pg.118]    [Pg.229]    [Pg.130]    [Pg.138]    [Pg.161]    [Pg.53]    [Pg.123]    [Pg.128]    [Pg.63]    [Pg.318]    [Pg.213]    [Pg.240]    [Pg.161]    [Pg.163]    [Pg.161]    [Pg.130]    [Pg.313]    [Pg.535]    [Pg.283]    [Pg.317]    [Pg.107]    [Pg.151]    [Pg.187]    [Pg.20]    [Pg.38]    [Pg.41]    [Pg.430]    [Pg.157]    [Pg.433]    [Pg.27]    [Pg.32]    [Pg.69]    [Pg.221]   
See also in sourсe #XX -- [ Pg.170 ]




SEARCH



Parameter calculation

© 2024 chempedia.info