Determination of distribution

Additional information concerning the mechanisms of solid—solid interactions has been obtained by many diverse experimental approaches, as the following examples testify adsorptive and catalytic properties of the reactant mixture [1,111], reflectance spectroscopy [420], NMR [421], EPR [347], electromotive force determinations [421], tracer experiments [422], and doping effects [423], This list cannot be comprehensive. Electron probe microanalysis has also been used as an analytical (rather than a kinetic) tool [422,424] for the determination of distributions of elements within the reactant mixture. Infrared analyses have been used [425] for the investigation of the solid state reactions between NH3 and S02 at low temperatures in the presence and in the absence of water. 

Methods to determine free energy (18,19) can be divided into three classes (i) Direct determination of distribution functions, (ii) Probe methods, (iii) Perturbation and integration methods. 

Brandstrom, A., A rapid method for the determination of distribution coefficinet of bases for biological purposes, Acta Chem. Scand. 17, 1218-1224 (1963). 

A simple rocking device was tested for routine determination of distribution coefficients [9], Sample cells were constructed for two-phase [9] and three-phase [10] systems. The investigators claim that the rocking action causes the shape of each phase to vary slowly and constantly and that the precision associated with the distribution coefficient is similar to that for shake-out methods. The three-phase cell was tested as an in vitro model to simulate factors involved in the absorption process. Rates of drug transfer and equilibrium drug distribution were evaluated under conditions in which one aqueous phase was maintained at pH 7.4 and the other phase was maintained at another pH. 

The determination of distribution pattern of various forms of both macroelements and heavy metals in soil profile is a very complicated task. We have to know the... 

Armstrong DW, Golden T. 1986. Determination of distribution and concentration of trihalomethanes in aquatic recreational and therapeutic facilities by electron capture GC. LC-GC 4 652-655. 

Przyjazny, A., Janicki, W., Chrzanowski, and Staszewki, R. Headspace gas chromatographic determination of distribution coefficients of selected organosulphur compounds and their dependence of some parameters, J. Chromatogr. A, 280 249-260, 1983. 

Simpson HJ, Trier RM, Li YH, et al. 1984. Field experiment determinations of distribution coefficients of actinide elements in alkaline lake environments. NucI Waste Geochem, 326-342. 

The use of Eqs. (3.13) for the determination of distribution coefficients is not always possible, because of the unknown correlation parameters, e.g. for the reversed phase. It is much more convenient to determine K. of functional molecules by examining at critical conditions a low-molecular-weight substance of a similar chemical structure and containing the same functional groups. Suitable for this purpose is a low-molecular-weight monofunctional homologue (the assumption Kj ra2 is sufficient for practical applications). 

Figure 3.6. Experimental determination of distribution coefficients for different cations in calcite at 25°C compared with the difference in free energies between Ca2+and N2+, where N is the cation. Katz et al. (1972) a Katz (1973) Bodineetal. (1965) Michard(1968) O Crocket and Winchester (1966) and Dardenne (1967) D Tsuesue and Holland (1966) O Lorens (1981) Mucci and Morse (1983). (After Sverjensky, 1984.)...

SEC has been shown (7) to give satisfactory results for latexes with broad particle size distributions as well. The method is particularly useful (7) in the determination of distributions of small particles when specific turbidity would provide only a turbidity (or weight) average diameter. 

The direct determination of distribution curves of particle size in suspensions." J. Soc. Chem. Ind. (London), 46 105T-107T. 

A necessary condition for the two-term expansion of the distribution function of equation (2) to be valid is that the electron collision frequency for momentum transfer must be larger than the total electron collision frequency for excitation for all values of electron energy. Under these conditions electron-heavy particle momentum-transfer collisions are of major importance in reducing the asymmetry in the distribution function. In many cases as pointed out by Phelps in ref. 34, this condition is not met in the analysis of N2, CO, and C02 transport data primarily because of large vibrational excitation cross sections. The effect on the accuracy of the determination of distribution functions as a result is a factor still remaining to be assessed. 

Determination of distribution of surface area and pore volume in relation to pore radius... 

Partition Coefficients of Ions Determination of Distribution Profiles. ... 

A suitable animal model can be used for in vivo pharmacokinetic assessment of a topically applied elastic liposome formulation. Rats and mice are most common but tend to provide an over-estimate compared to human skin as the skin is more permeable. Piglets provide a closer approximation to human skin permeability and have been used for some evaluations of elastic liposomes (9, 34). Appropriate animal ethics committee approval is required. A generalised protocol is outlined in the following section but there can be considerable variation depending on the complexity of information sought, i.e., if the determination of distribution into tissues is required in addition to absorption into the circulation ... 

Doong, R. and Chang, S., Determination of distribution coefficients of priority polycyclic aromatic hydrocarbons using solid-phase microextraction. Anal Chem., 72, 3647-3652, 2000. 

Determinants of distribution The distribution of drugs to the tissues depends upon the following ... 

For confirmation of adequacy of chosen technique for experimental determination of distributions of reagents residence times in tubular turbulent apparatus numerical calculation of three-dimensional turbulent liquid flow with the use of CFD soft PHOENICS was carried out. 

European Standard ENV 1007-5 Determination of distribution of tensile strength and of tensile strain to failure of filaments within a multifilament tow at ambient temperature CEN TC 184, European Committee for Standardization, Brussels, Belgium. April 1998. 

In experiments at trace level or very low loading of one ion, the isotope dilution procedure is not required. All that is necessary is that the exchangeable ions on the solid be those of the salt present in macro concentration. The computation of results, which followed that conventionally used in the determination of distribution coefficients, ignores possible effects of colon exclusion from water in the clay pack it is implicitly assumed that the water in the pack has the same coion concentration as the supernatant solution. It is possible that coion exclusion has an effect which may be significant on distribution coefficients (particularly when they are low) and on capacities computed from the results. We shall discuss this interference later in connection with the capacities measured by displacement of both cations and anions from the clay pack and associated water. Coion exclusion has been further discussed in references 1 and 7 (see also 8, 9, and 10). 

Molecular geometry, determination of cis- and trans isomers, distortion from cubic symmetry (Jahn-Teller effect), effect of polymerization, finding the right structure of polynuclear complexes, identification of possible structural position occupied by the Mossbauer atom, determination of distribution of Mossbauer atoms among the sites, determination of site preference, determination of coordination number, effect of neighbors... 

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