Sorting coefficient

Isotopic fractionation factor kdt also used as temporary parameters of various sorts Used as temporary coefficients of various sorts Coefficients (such as activity coefficients)... 

Figure 25.5 Permeability as a function of (mean) particle radius r for different aquifer porosity < >, which, in turn, depends on the sorting coefficient So = (r75 / r25)1,2, where r75 and r2S characterize the particle radii larger than, respectively, 75% and 25% of the radii of all the aquifer particles. The hydraulic conductivity Kq (right scale) refers to water at 20°C. Redrawn from Lerman (1979).

If r is defined as the mean particle radius, Eq. 25-7 also can be used for aquifers that consist of particles of different size. Then the parameter a depends on the particle size distribution. It increases with porosity ( ), which in turn is linked to the so-called sorting coefficient, So (see Fig. 25.5). Small So values indicate greater uniformity of the particles large So values indicate a greater variance of the particle size, that is, a denser packing (small particles fill the space in between the larger ones). Therefore,... 

Figure 4. Sketch of distribution of seabed sediment sorting coefficient (Qdcp).

Majia Shoal mainly consists of median-coarse sand and median-fine sand. Median sand is deposited from top to -15 m—20 m depth, with layer thickness of 10 m 15 m (see Fig. 4). d50 of the sandy layer is between 0.20 mm and 0.40 mm in vertical, with an average of 0.30 mm. Sorting coefficient of sand is between 0.23 and 0.64, and the sand is sorted very well. 

Cera.mic, The ceramic substrate is made from a mixture of siUcon dioxide, talc, and kaolin to make the compound cordierite [12182-53-5]. Cordierite possesses a very low coefficient of thermal expansion and is thermal-shock resistant. The manufacturing process involves extmding the starting mixture (which is mixed with water and kneaded into a sort of dough) through a complex die to form the honeycomb stmcture. The extmded piece is dried and fired in a kiln to form the cordierite. The outside or circumferential dimension is formed by the die, and the length is cut later with a ceramic saw. 

For exposure of reasons of observable discrepancy of results of the analysis simulated experiment with application synthetic reference samples of aerosols [1]. The models have demonstrated absence of significant systematic errors in results XRF. While results AAA and FMA depend on sort of chemical combination of an elements, method of an ashing of a material and mass of silicic acid remaining after an ashing of samples. The investigations performed have shown that silicic acid adsorbs up to 40 % (rel.) ions of metals. The coefficient of a variation V, describing effect of the indicated factors on results of the analysis, varies %) for Mn and Fe from 5 up to 20, for Cu - from 10 up to 40, for Pb - from 10 up to 70, for Co the ambassador of a dry ashing of samples - exceeds 50. At definition Cr by a method AAA the value V reaches 70 %, if element presences an atmosphere in the form of Cr O. At photometric definition Cr (VI) the value V is equal 40%, when the element is present at aerosols in the form of chromates of heavy metals. 

The first theoretical attempts in the field of time-resolved X-ray diffraction were entirely empirical. More precise theoretical work appeared only in the late 1990s and is due to Wilson et al. [13-16]. However, this theoretical work still remained preliminary. A really satisfactory approach must be statistical. In fact, macroscopic transport coefficients like diffusion constant or chemical rate constant break down at ultrashort time scales. Even the notion of a molecule becomes ambiguous at which interatomic distance can the atoms A and B of a molecule A-B be considered to be free Another element of consideration is that the electric field of the laser pump is strong, and that its interaction with matter is nonlinear. What is needed is thus a statistical theory reminiscent of those from time-resolved optical spectroscopy. A theory of this sort was elaborated by Bratos and co-workers and was published over the last few years [17-19]. 

Starting in the 1960s, many compounds with such properties were discovered (i.e., with high conductivities and low-temperature coefficients of conductivity). Some of them are double salts with silver iodide (uAgFmMX) or other silver halides where MX has either the cation or the anion in common with the silver halide. The best-known example is RbAgJj (= 4AgFRbI), where this sort of conduction arises at - 155°C and is preserved up to temperatures above 200°C. At 25°C this compound has a conductivity of 26 S/m (i.e., the same value as found for a 7% KOH solution). Another example is Ag3SI, which above 235°C forms an a-phase with a conductivity of 100 S/m. 

The present theory can be placed in some sort of perspective by dividing the nonequilibrium field into thermodynamics and statistical mechanics. As will become clearer later, the division between the two is fuzzy, but for the present purposes nonequilibrium thermodynamics will be considered that phenomenological theory that takes the existence of the transport coefficients and laws as axiomatic. Nonequilibrium statistical mechanics will be taken to be that field that deals with molecular-level (i.e., phase space) quantities such as probabilities and time correlation functions. The probability, fluctuations, and evolution of macrostates belong to the overlap of the two fields. 

As before, the total energy, E, can be minimized by optimizing the mixing coefficients c so that dE/dci is zero. In the case of a system comprising two configurations, this leads to the same sort of determinantal equation that was obtained when we minimized the en-... 

The reason why the authors do not sort the DCT data before fitting the DCT polynomial is as follows. If the data get sorted then it becomes monotonically increasing or decreasing (according to the sorting). Hence the data can be very well modeled with low degree polynomial with very small mean square error. Thus, when one gets back to the DCT coefficients from the polynomial, the modified data (and also the data that are not modified) are not disturbed much and consequently the watermark is not removed. 

Once the value of maB has been established, the evaluation of the remaining terms in Eq. (150) for the activity coefficient follows quite simply. The fourth term on the right-hand side clearly involves interactions of oppositely charged defects of the sort considered in the Lidiard-Bjerrum theory. It can be written for the systems under consideration as... 

This form of the partition coefficient, analogous to that used for Fe-Mg fractionation between olivine and melt (see Chapter 1), is necessary only for the rare cases where trace substitution affects Cj and Cp substantially. A number of reviews (O Nions and Powell, 1977 Michard, 1989) describe the various sorts of partition coefficients expressed either in mass-fractions, atom fractions, or normalized to a major element and their respective merits. If the discussion is restricted to a narrow range of chemical compositions (e.g., basaltic systems, Irving, 1978, Irving and Frey, 1984), enough experimental information exists on trace-element partitioning to resort to the wonderfully simple equation (9.1.1). 

The movement of the analyte is an essential feature of separation techniques and it is possible to define in general terms the forces that cause such movement (Figure 3.1). If a force is applied to a molecule, its movement will be impeded by a retarding force of some sort. This may be as simple as the frictional effect of moving past the solvent molecules or it may be the effect of adsorption to a solid phase. In many methods the strength of the force used is not important but the variations in the resulting net force for different molecules provide the basis for the separation. In some cases, however, the intensity of the force applied is important and in ultracentrifugal techniques not only can separation be achieved but various physical constants for the molecule can also be determined, e.g. relative molecular mass or diffusion coefficient. 

Either Transwell inserts or side-by-side diffusion chambers can be used for transport studies. Bode et al. have provided an excellent review on this subject [60], Briefly, cells are incubated for 30-60 min with a buffer solution. To initiate the transport study, a transport buffer containing the drug under investigation is added to either the apical or the basal chamber depending on the transport direction of interest. At predetermined time points, the respective receiver chamber is sampled and the withdrawn volume is replaced with the same volume of fresh buffer. The permeability coefficient (Papp) is calculated and the ratio of /apP in the basolateral-to-apical direction versus that in the apical-to-basolateral direction gives the efflux ratio. These sort of transport experiments are well suited to determine if drugs/xenobiotics are substrates of the placental efflux proteins. 

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