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Partitioned matrix, general

We will use constraint matrices to describe the classification of the isomers into various classes a given ligand partition is characterized by a matrix where each row is associated with a class and each column with an isomer in the general ligand partition. Such a matrix 0 has therefore z rows and twenty columns. In a given row, we put one in the column of the isomers belonging to the class of the row. Of course, there is one and only one non-vanishing element in each column, and... [Pg.56]

The extent of the cleanup depends on the sample matrix to be analyzed, the extraction procedure, the method of detection and the desired sensitivity. Generally, the cleanup method is liquid-liquid partitioning (LLP), but recently it has become simpler and more reliable to use solid-phase extraction (SPE) columns. [Pg.1131]

However, since and -5 asymptote to the same function, one might approximate (U) = S dJ) in (3.57) so that the acceptance probability is a constant.3 The procedure allows trial swaps to be accepted with 100% probability. This general parallel processing scheme, in which the macrostate range is divided into windows and configuration swaps are permitted, is not limited to density-of-states simulations or the WL algorithm in particular. Alternate partition functions can be calculated in this way, such as from previous discussions, and the parallel implementation is also feasible for the multicanonical approach [34] and transition-matrix calculations [35],... [Pg.104]

Liquid-liquid partitioning cleanup is generally directed to removal of the matrix constitutents from the aqueous extract into organic immiscible solvents (14, 298, 299, 302, 308). Unfortunately, tetracyclines cannot be quantitatively recovered into organic immiscible solvents at any pH value because of their high polarity. However, recoveries higher than 85% were reported when tetrabutylammonium ions were employed in the ion-pair extraction of oxytetracycline and tetracycline into dichloromethane at pH 8.2 (297). [Pg.987]

The organization of this paper is as follows First, we will present some of the evidences which point to the existence of the chain theta point and to the possibility of the configurational transition, based on the recently conducted Monte Carlo studies by McCrackin and Mazur.2 Next, we will describe the chain as a stochastic process of dependent events. This stochastic process will serve as a basis for the formulation of the chain partition function. The chain partition function will be subsequently expanded in terms of the eigenvalues of the transition matrix. We will also present a general outline showing how the study of the distribution of the eigenvalues of the transition matrix could be employed in conjunction with the Monte Carlo calculations in order to study the thermodynamic... [Pg.262]

Extractions generally rely on a favourable partition of PCBs from the sample matrix into the extraction matrix. The more favourable the partition coefficient, the higher is the extraction efficiency. Since PCBs are lipophilic, the extraction methods are based on the isolation of lipids from the sample matrix [30]. It should be noted that the concentration of planar or non-ortho-substituted PCBs, which are considered the most toxic PCB congeners, is generally 1000-fold lower (ng/kg) than... [Pg.597]

Partitioning technique refers to the division of data into isolated sections and it was put into successful practice in connection with matrix operations. Lowdin, in his pioneering studies, [21, 22] developed standard finite dimensional formulas into general operator transformations, including treatments appropriate for both the bound state and the continuous part of the spectrum, see also details in later appendices. Complementary generalizations to resonance-type problems were initiated in Ref. [23], and simple variational formulations were demonstrated in Refs. [24,25]. Note that analogous forms were derived for the Liouville equation [26, 27] and further developed in connection with a retarded-advanced subdynamics formulation [28]. [Pg.86]

The methods that generally are used to remove volatile organic chemicals (VOCs) from biological samples for analysis are applicable to chlorobenzene. These include headspace analysis, purge-and-trap (gas stripping) collection from aqueous solutions or slurry samples, solvent extraction, and direct collection on resins. Headspace analysis offers speed, simplicity, and good reproducibility for a particular type of sample. However, partitioning of the analyte between the headspace and the sample matrix is dependent upon the nature of the matrix and must be determined separately for different kinds of matrices (Walters 1986). [Pg.61]

Enhanced HOC solubility in surfactant systems generally has been quantified by a distribution coefficient that only considers HOC partitioning to surfactant micelles that exist above the critical micelle concentration (CMC). Although surfactants can form a mobile micellar pseudophase that leads to the facilitated transport of solubilized HOCs, they also can be adsorbed by the solid matrix and thereby lead to HOC partitioning to immobile sorbed surfactants and, thus, enhanced HOC retardation. Therefore, the effectiveness of a remediation scheme utilizing surfactants depends on the distribution of an HOC between immobile compartments (e.g., subsurface solids, sorbed surfactants) and mobile compartments (e.g., water, micelles). [Pg.188]

Sequential extraction involves treatment of a sample of soil or sediment with a series of reagents in order to partition the trace element content. The reagents used are generally similar to those employed as single extractants to liberate metals bound to particular components of the sample matrix, discussed above. The growth in popularity of the approach is demonstrated by the marked increase in publications in which it has featured over the past decade (Fig. 10.2). [Pg.276]

For simplicity, hereinafter one considers single-component adsorption where s — 2, i — A (a site is occupied), i — v (a site is free), and avpv — 1. The matrix method (MM) [17,19] may serve to either confirm or impugn the results obtained by MC. MM is based on a generally plausible assumption that the surface fragment with AMm sites can recur periodically along some direction. The MM analog of partition function (A. 1) is... [Pg.446]


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See also in sourсe #XX -- [ Pg.545 ]




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