Noncontact starts

This is even more so for noncontact starts, especially for slow diffusion (tpc —> 0). As was mentioned, CA leads to the finite value of the charge separation yield in the static limit when cpc = D = 0. In highly polar solvents this quantity, lim =0 dashed line 2b (drawn for 8 = 1) with ordinate (Fig. 3.25). Instead, the remote recombination theory provides the following formula, deduced in the quasistatic limit from the general Eq. (3.224) ... 

Here z = WqLR is identical to the EM parameter provided Wo = k-el. Z(D) behavior for inner starts is qualitatively similar for contact starts from the exponential reaction zone. The noncontact starts from the exponential reaction zone are also similar to the starts from inside the rectangular recombination zone. Only for starts outside this zone, Z(D) is a monotonically increasing function of the diffusion coefficient [Fig. 3.26(h)]. For thin layers (qL << 1) this dependence coincides with that predicted by the CA Eq. (3.209). This is a consequence of the artificially sharp borders of the rectangular recombination layer. Ions that are born outside do not react in principle unless diffusion delivers them into the reaction zone. 

Commercial applications of UTT measurement started in 1976 however, the method has not found widespread use. An important application in extrusion is the noncontacting temperature measurement of heat-sensitive materials. Protruding temperature sensors can easily cause degradation with such materials. The UTT measurement, pressure compensated, can be used for stock temperature control in a similar fashion as with the conventional melt temperature sensor (see Section 4.6). 

Because the study of liquid interfaces by scanning probe microscopy [SPM] requires using specific tips usually milled with FIB or else using high-aspect-ratio tips grown at the apex, micro- and nanofluidics using SPM has started only recently. When a standard pyramidal tip is put in contact with a liquid surface, a large meniscus is created and is detrimental to any measurement. Noncontact... 

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