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Accuracy evaluation evolution

CT-VPP-REDOR) or the pulse duration fp (CT-VPD-REDOR) then produces CT-REDOR curves, from which the second moment may be evaluated with distinctively superior accuracy as compared to the values obtained from a parabolic fit to the conventional REDOR data. When restricting the experiment to short dipolar evolution times, the two-spin approximation may be applied for the data analysis, which proves to be especially attractive for amorphous solids, for which the exact spin geometry is unknovm. The data presented on the model compoimds illustrate the various facets of CT-REDOR NMR spectroscopy. First application examples, namely, the evaluation of the heteronuclear Li-Ti dipolar couplings within the garnet structure of Li5La3Nb20i2, the determi-nation of the intemuclear B- P distance in frustrated Lewis pairs, the analysis of Na- F dipolar interaction in fluormica or Na- P... [Pg.21]

Definitions 2 and 3 allow an evolution in the different techniques and methods as definitive methods for the same analyte (Leijnse, 1982). Indeed, even though systematic errors were investigated during the initial research work, later technical advances may uncover errors that were undetected during the original measurements. The end use and end purposes of the definitive method include the evaluation of the accuracy of reference methods and its application to the quantitation of analytes in certified reference materials present in a biological matrix. [Pg.143]

Obviously, the universal goal of any measurement technique is to obtain reproducible results regardless whether the samples come from different sources with different matrix effects, are run by different operators, in different laboratories, on different occasions and using different lots of reagents. This is usually accomplished by characterization of the newly developed assay in terms of sensitivity, selectivity, robustness and correctness (i.e., accuracy and precision). Evaluation of sensitivity and precision does not normally constitute a problem for a newly developed immunoassay, and accuracy can be attained by comparison with the results obtained by a reference ( standard ) method. However, the evolution of assay standardization from this point on is much more difflcult. The following section deals with application-specific problems related to validation and standardization of immimoassay. [Pg.617]

The (n + 1)-dimensional Krylov space constructed in Eq. (C.5) spans locally over p(t) and the subsequent n actions of A(t). As an orthogonal but incomplete basis set, the Gaussian quadrature accuracy of order would be expected for the n-dimensional Krylov space approximation. It thus allows the time-local evolution, p t + St) exp[A(t)St]p t) be evaluated accurately with a fairly large St, The project-out error can be estimated similarly as that of the short-iterative-Lanczos Hilbert-space propagator [51]. [Pg.33]

Although nonlinear effects have been found to be important, some issues remain unresolved. First, we need an evaluation of the accuracy with which the kurtosis is estimated from spectra. BFI originally describes the as3unptotic behavior, given an initial value, but in reality, there is no initial condition in the ocean. This should be verified in the near future. Second, we need to accoimt for wave directionality. In real sea states, directional effects are important. Directional contributions to the evolution of the kurtosis, using a modified nonlinear Schrodinger equation, have been described, and the effects of four-wave interactions only appear close to long-crested waves conditions. A quantitative discussion of directional effects should be presented in the near future. [Pg.147]

The hydrogen evolution method is also superior to the estimation of corrosion rate from polarization curve in terms of measurement accuracy. The application of the traditional Tafel extrapolation in estimating the corrosion rates of Mg and its alloys is actually questionable and in many cases can lead to a misleading result, although it has been employed to investigate or evaluate the corrosion performance of Mg and its alloys in some studies (Bonora et al, 2000 Eliezer et al, 2000 Hallopeau et al., 1997 Krishnamurthy et al., 1988 Mathieu et al., 2000). [Pg.40]

This selection process is then iterated, beginning from an initial state of the system, as defined by species populations, to simulate a chemical evolution. A statistical ensemble is generated by repeated simulation of the chemical evolution using different sequences of random numbers in the Monte Carlo selection process. Within limits imposed by computer time restrictions, ensemble population averages and relevant statistical information can be evaluated to any desired degree of accuracy. In particular, reliable values for the first several moments of the distribution can be obtained both inexpensively and efficiently via a computer algorithm which is incredibly easy to implement (21, 22), especially in comparison to now-standard techniques foF soTving the stiff ordinary differential equations (48, 49) which may arise in the deterministic description of chemical kinetics (53). Now consider briefly the essential features of a simple chemical model which illustrates well the attributes of stochastic chemical simulations. [Pg.253]


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See also in sourсe #XX -- [ Pg.75 ]

See also in sourсe #XX -- [ Pg.75 ]




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Accuracy evaluation

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