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Kinetic covariates

It should be emphasized that for Markovian copolymers a knowledge of the values of structural parameters of such a kind will suffice to find the probability of any sequence Uk, i.e. for an exhaustive description of the microstructure of the chains of these copolymers with a given average composition. As for the composition distribution of Markovian copolymers, this obeys for any fraction of Z-mers the Gaussian formula whose covariance matrix elements are Dap/l where Dap depend solely on the values of structural parameters [2]. The calculation of their dependence on time, and the stoichiometric and kinetic parameters of the reaction system permits a complete statistical description of the chemical structure of Markovian copolymers to be accomplished. The above reasoning reveals to which extent the mathematical modeling of the processes of the copolymer synthesis is easier to perform provided the alternation of units in macromolecules is known to obey Markovian statistics. [Pg.167]

All current taxometric procedures are based on a single statistical method termed Coherent Cut Kinetics (CCK). We decipher the meaning of this term in the next section in the example of the MAXCOV-HITMAX (MAXCOV stands for MAXimal COVariance the reason for this name will become clear in the next section) technique. However, we emphasize that it is not the shared statistical method that defines taxometrics. Adherence to a particular set of epistemological principles distinguishes taxometrics from other approaches. In other words, any analytic procedure that can identify taxa may... [Pg.31]

Let us review what we did with the depression example so far. First, we conjectured a taxon and three indicators. Next, we selected one of these indicators (anhedonia) as the input variable and two other indicators (sadness and suicidality) as the output variables. Input and output are labels that refer to a role of the indicator in a given subanalysis. We cut the input indicator into intervals, hence the word Cut in the name of the method (Coherent Cut Kinetics), and we looked at the relationship between the output indicators. Specifically, we calculated covariances of the output indicators in each interval, hence the word Kinetics —we moved calculations from interval to interval. Suppose that after all that was completed, we find a clear peak in the covariance of sadness and suicidality, which allows us to estimate the position of the hitmax and the taxon base rate. What next Now we need to get multiple estimates of these parameters. To achieve this, we change the... [Pg.42]

The kinetic profile of reactions involving the micelle s counterions is frequently analyzed in terms of the PIE model. Despite the known shortcomings of this model, it nevertheless typically reproduces kinetic data rather well - though one should remain conscious of the potential problems related to parameter covariance (vide supra). [Pg.26]

It should be emphasized that for the Markovian copolymers, the knowledge of these structure parameters will suffice for finding the probabilities of any sequences LZ, i.e., for a comprehensive description of the structure of the chains of such copolymers at their given average composition. As for the CD of the Markovian copolymers, for any fraction of Z-mers it is described at Z 1 by the normal Gaussian distribution with covariance matrix, which is controlled along with Z only by the values of structure parameters (Lowry, 1970). The calculation of their dependence on time and on the kinetic parameters of a reaction system enables a complete statistical description of the chemical structure of a Markovian copolymer. It is obvious therewith to which extent a mathematical modeling of the processes of the synthesis of linear copolymers becomes simpler when the sequence of units in their macromolecules is known to obey Markov statistics. [Pg.172]

Much of what is currently understood about the Cenozoic history, of deep-sea temperature, carbon chemistry, and global ice volume, has been gleaned from the stable isotope ratios of benthic foraminifera. Benthic foraminifera extract carbonate and other ions from seawater to construct their tests. In many species, this is achieved near carbon and oxygen isotopic equilibrium. Kinetic fractionation effects tend to be small and constant (Grossman, 1984, 1987). As a result, shell fi C and strongly covary with the isotopic... [Pg.3396]

Pigure 9 shows an electron-ion covariance map obtained at the same time as Pig. 8b. Por convenience the time-averaged electron and ion TOP spectra are shown alongside the x and y axes. The electron TOP is virtually structureless, the slight forward-backward asymmetry and the peak at 292 ns being due to a small inhomogeneity in the extraction field. The forward electrons are unaffected and a kinetic energy scale is shown for both electrons and protons. In order to ensure that this lack of structure was not the result of poor instrumental resolution, an electron TOP spectrum of Xe was taken under identical conditions. A series of ATI peaks was observed in both the forward and backward direction, separated by about 2 eV. [Pg.17]

For the particular case of second-order kinetics the concentration covariance... [Pg.713]

To model the particle velocity fluctuation covariances caused by particle-particle collisions and particle interactions with the interstitial gas phase, the concept of kinetic theory of granular flows is adapted (see chap 4). This theory is based on an analogy between the particles and the molecules of dense gases. The particulate phase is thus represented as a population of identical, smooth and inelastic spheres. In order to predict the form of the transport equations for a granular material the classical framework from the kinetic theory of... [Pg.921]

Proper boundary conditions are generally required for the primary variables like the gas and particle velocities, pressures and volume fractions at all the vessel boundaries as these model equations are elliptic. Moreover, boundary conditions for the granular temperature of the particulate phase is required for the PT, PGT and PGTDV models. For the models including gas phase turbulence, i.e., PGT and PGTDV, additional boundary conditions for the turbulent kinetic energy of the gas phase, as well as the dissipation rate of the gas phase and the gas-particle fluctuation covariance are required. The... [Pg.927]

The wide variation in the kinetics of the anti-mAb response and lack of sufficient anti-mAb data prevented the development of a model that could be used to predict the anti-mAb response in anti-mAb-positive patients. It was also possible that the presence of mAb caused interference in the anti-mAb assay. For these reasons, the mAb model used a simplified metric of anti-mAb levels to account for the impact of anti-mAb on mAb elimination. In both studies, the anti-mAb titer measured 4 weeks after dosing was found to be a reasonable covariate that predicted both the... [Pg.1139]

There are significant relationships between the values of both shell carbonate and organic tissues with immersion time. There are a large number of explanations for variations in the carbonate skeletons of organisms in nature, however few of the available explanations would produce the small, systematic change of c. l%e observed over the 3.5 m of sample profile. Only kinetic effects, metaholic effects, varying pH or the local influx of C-depleted waters are likely to have been able to significantly influence shell isotope composition over the spatial scale sampled. An influx of C-depleted meteoric water derived from adjacent terrestrial areas should lead to covariance between and 8 0 in the shell carbonate. This is not observed and hence can be discounted as the mechanism behind the observed relationship. [Pg.180]

As demonstrated in the definition of Mi, M2 and M3, kinetic parameters preset as constants for kinetic analysis of GST reaction curve should have strong covariance. Except Kiq as an unknown kinetic parameter for optimization, other kinetic parameters are those reported (Kunze, 1997 Pabst, et al, 1974). To optimize Kiq, two criteria are used. The first is the consistency of predicted Am at a series of GSH concentrations using data of 6.0-min reaction with that by the equilibrium method after 40 min reaction (GST activity is optimized to complete the reaction within 40 min). The second is the resistance of Vm to reasonable changes in data ranges for analyses. After stepwise optimization, Kiq is fixed at 4.0 pmol/L Am predicted for GSH from 5.0 pmol/L to 50 pmol/L is consistent with that by the equilibrium method (Zhao, L.N., et al. 2006) the estimation of Vm is resistant to changes of data ranges (Fig. 5). Therefore, Kiq is optimized and fixed as a constant at 4.0 pmol/L. [Pg.174]

Simple linear regressions between each of the independent variables can be used to produce a correlation matrix. The values of R in this matrix can be used to identify possible covariance problems. Once statistical significance of various factors is established, the corrosion researcher should consider the corrosion processes and first principles in reaction kinetics to evtiluate the consistency of the statistical model with a physical model. Best fits of data to physical models can yield valuable information such as activation energies that can point toward diffusion controlled or activation controlled processes. [Pg.87]


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See also in sourсe #XX -- [ Pg.40 , Pg.272 ]




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Covariance kinetics

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Covariation

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