Big Chemical Encyclopedia

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

Articles Figures Tables About

Predictions model-free

The respective predictions can be called model-free predictions , because they do not require the reaction model to be used explicitly in the numerator of equation (47) and (48). Note, that the pre-exponential factor is also unnecessary for making predictions by equation (47) and (48). [Pg.530]

It has been experimentally demonstrated [17,75,85] that the model-free equations give rise to reliable predictions, whereas substitution of the kinetic triplets, obtained from a single heating rate run, into equation (44) yields fundamentally erroneous predictions. It has also been shown that the model-free predictions are superior to the predictions based on the ASTM method (equation... [Pg.531]

The limitations of the ASTM method are avoided in the model-free predictions (Vyazovkin 1996), which make use of the dependence of on a determined by an isoconversional method. The predictive equation was originally proposed in the following form ... [Pg.294]

The respective predictions are called model-free predictions because they eliminate the reaction model g(a) in the numerator of Eq. (3.27). [Pg.294]

Model-free predictions are typically superior to predictions based on the ASTM method. Figure 3.29 provides an example of using Eqs. (3.28) (ASTM... [Pg.294]

Using Happel s free surface model, which predicts (H10) ... [Pg.373]

The micro-kinetic model also predicts the coverages of the various intermediates on the surface. As shown in Tab. 8.2, the approximation of the surface being dean is quite reasonable. The highest coverages are observed for hydrogen and formate, but the majority of sites are free, even at 50 bar. [Pg.316]

In this contribution we will deal with electron-electron correlation in solids and how to learn about these by means of inelastic X-ray scattering both in the regime of small and large momentum transfer. We will compare the predictions of simple models (free electron gas, jellium model) and more sophisticated ones (calculations using the self-energy influenced spectral weight function) to experimental results. In a last step, lattice effects will be included in the theoretical treatment. [Pg.190]

Combined use of Eqs. (43)—(45) allows free drug concentrations to be predicted for each subcompartment. This approach to modeling free drug concentrations would make use of protein binding parameters (i.e., Bt, Kt) obtained from in vitro experiments. [Pg.87]

Once more, free-electron models correctly predict many qualitative trends and demonstrate the appropriateness of the general concept of electron delocalization in molecules. Free electron models are strictly one-electron simulations. The energy levels that are used to predict the distribution of several delocalized electrons are likewise one-electron levels. Interelectronic effects are therefore completely ignored and modelling the behaviour of many-electron systems in the same crude potential field is ndt feasible. Whatever level of sophistication may be aimed for when performing more realistic calculations, the basic fact of delocalized electronic waves in molecular systems remains of central importance... [Pg.332]

An important advance in the understanding of the chemical behaviour of glasses in aqueous solution was made in 1977, when Paul (1977) published a theoretical model for the various processes based on the calculation of the standard free energy (AG ) and equilibrium constants for the reactions of the components with water. This model successfully predicted many of the empirically derived phenomena described above, such as the increased durability resulting from the addition of small amounts of CaO to the glass, and forms the basis for our current understanding of the kinetic and thermodynamic behaviour of glass in aqueous media. [Pg.171]

Since the rate for the tunneling of a proton is strongly dependent on barrier width, it is necessary that the molecular systems to be studied constrain the distance of proton transfer. Also, since the various theoretical models make predictions as to how the rate of proton transfer should vary with a change in free energy for reaction as well as how the rate constant should vary with solvent, it is desirable to study molecular systems where both the driving force for the reaction and the solvent can be varied widely. [Pg.64]

In 2007, Wichmann et al. [47] applied several COSMO-RS cr-moments as descriptors to model PPB. Unlike the above-mentioned PPB models, which predicted %PPB directly, Wichmann et al. built up a QSAR model to predict human serum albumin binding, log Kt SA (logarithm of %bound/%free), instead. The performance of the log K isa model was reasonable given only four... [Pg.116]

The success of this simple four site model in predicting the relative site intensities using only one free parameter, taken together with the calculated linear dependence of the f-factors on the coordination number, is yet another confirmation of the assumed structure of AU55. [Pg.10]


See other pages where Predictions model-free is mentioned: [Pg.503]    [Pg.531]    [Pg.295]    [Pg.503]    [Pg.531]    [Pg.295]    [Pg.457]    [Pg.520]    [Pg.91]    [Pg.16]    [Pg.307]    [Pg.15]    [Pg.333]    [Pg.99]    [Pg.382]    [Pg.451]    [Pg.44]    [Pg.410]    [Pg.348]    [Pg.331]    [Pg.232]    [Pg.458]    [Pg.44]    [Pg.61]    [Pg.508]    [Pg.488]    [Pg.29]    [Pg.303]    [Pg.63]    [Pg.84]    [Pg.97]    [Pg.182]    [Pg.26]    [Pg.955]    [Pg.199]    [Pg.68]    [Pg.216]   
See also in sourсe #XX -- [ Pg.294 ]




SEARCH



Model-free

Modeling Predictions

Modelling predictive

Prediction model

Prediction techniques free energy modeling

Predictive models

Structure prediction techniques free energy modeling

© 2024 chempedia.info