Mobile fines

Other minerals beside water-swelling clays have been found to undergo fines migration. The permeability damage caused by essentially non-swelling clays such as kaolinite and chlorite is a well-known phenomenon. Silica fines have been identified as a potential source of permeability damage in various poorly consolidated U.S. Gulf Coast formations (1). Other minerals identified as constituents of mobile fine particles include feldspar, calcite, dolomite, and siderite (4,5). 

C Mobile, fine-grained, found in slack zones, in isolation and overlying type A 1.17 29-45-73 5-55-71 0 50... 

In liquid-solid adsorption chromatography (LSC) the column packing also serves as the stationary phase. In Tswett s original work the stationary phase was finely divided CaCOa, but modern columns employ porous 3-10-)J,m particles of silica or alumina. Since the stationary phase is polar, the mobile phase is usually a nonpolar or moderately polar solvent. Typical mobile phases include hexane, isooctane, and methylene chloride. The usual order of elution, from shorter to longer retention times, is... 

In this equation, Zp is the electrical mobility of the particle. In the case of fine particles, the slip correction must be taken into account, and the mobility is given by... 

A quite different approach was introduced in the early 1980s [44-46], in which a dense solid electrode is fabricated which has a composite microstructure in which particles of the reactant phase are finely dispersed within a solid, electronically conducting matrix in which the electroactive species is also mobile. There is thus a large internal reactant/mixed-conductor matrix interfacial area. The electroactive species is transported through the solid matrix to this interfacial region, where it undergoes the chemical part of the electrode reaction. Since the matrix material is also an electronic conductor, it can also act as the electrode s current collector. The electrochemical part of the reaction takes place on the outer surface of the composite electrode. 

In contrast to PEG-1000, the ESR-spectra obtained for labelled grafted PEO-oligomers (N = 1-9) were reported to differ strongly from that for N = 23 and exhibited only slowly moving labels. As the fine width of the fast domain spectrum depends on the mobility of the label, it can be concluded that the tails for N = 23 must consist of at least 4-9 repeated units. It appears that some tails are rather long. 

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