Migration rate of species

In the sediments being studied, it is believed that nuclide migration away from the waste form will primarily be due to molecular diffusion. The simpler mathematical analyses of diffusion which yield anal3rbical solutions show that, to a first approximation, the migration rate of species i should generally be inversely proportional to the magnitude of Kp (l). Hence, the... 

Ca) is fixed. The velocity is variously called the concentration wave velocity of species i, the migration rate of species i or the concentration front propagation velocity of species i (Sherwood et al., 1975). A more formal method of arriving at expression (7.1.12a) is given below. 

Capillary electrophoresis offers several useful methods for (i) fast, highly efficient separations of ionic species (ii) fast separations of macromolecules (biopolymers) and (iii) development of small volume separations-based sensors. The very low-solvent flow (l-10nL min-1) CE technique, which is capable of providing exceptional separation efficiencies, places great demands on injection, detection and the other processes involved. The total volume of the capillaries typically used in CE is a few microlitres. CE instrumentation must deliver nL volumes reproducibly every time. The peak width of an analyte obtained from an electropherogram depends not only on the bandwidth of the analyte in the capillary but also on the migration rate of the analyte. 

As seen earlier, cation exchange of montmorillonite has an important role in agricultural applications. In these cases, cations sorbed previously on bentonite are added to the soil. The opposite process, however, is also important in environmental applications, namely, when polluting cations have to be sorbed on bentonite. Such applications are the clay barriers of waste disposals. The high CEC is desirable. The sorption of cationic species decreases the migration rate of wastes, too (Section 3.2). 

Laminating adhesive is always behind a barrier film layer. The thickness of this layer, the levels of crystallinity as well as polymer type all influence the migration rates of adhesive components through this layer. The rate of permeation of food or food simulant into the packaging is also controlled by the nature of the food contact layer. Because of the presence of this barrier layer between the adhesive and the food, it is only low molecular weight mobile chemical species that have the potential to contaminate food. 

The first column provides the two essential functions of adsorption and separation. If the mixed species are easily separated lower column ratios are required and the loading capacity can be increased or reduced. For a basic study only the third column, a glass one, is used. The change of bandshape can, as a result, be directly observed while the migration rate of the separation band can be easily monitored by watching its movement in this glass column. 

Electrophoresis Difference in migration rate of charged species in an electric field... 

Capillary zone electrophoresis (CZE) is a relatively recent separation technique based on the differential migration rates of ionic species in an electrical... 

Distribution ratio. The distribution of an ionic species between the ion exchanger and the contacting phase is an important term in ion-exchange chromatography, because the migration rate of the ion on the chromatographic column and hence the position of the peak of the component in the chromatogram is controlled by the distribution ratio. 

The pressure of the reactor must also be defined, and acronyms APCVD, LPCVD, and SCF-CVD are used to denote ambient, in vacuo, and supercritical pressure conditions within the deposition chamber, respectively. In general, the resultant film conformality of a CVD process follows the order LPCVD > APCVD, due to the relative migration rates of intermediate species along the surface of the substrate. However, it has recently been shown that conformal thin films of metal oxides may be deposited on nonplanar substrates such as carbon fibers under APCVD, even at low temperature. 

If we assume that the rates of adsorption and desorption are both large compared with the surface migration rate, the surface and bulk concentrations of each species will be almost in equlibriura, and hence will be... 

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