Electro-osmotic

Fig. 5-8 Total adhesion loss of a 500-/xm-thick coating of EP (liquid lacquer), 0.2 M NaCI, galvanostatic = -1.5 /tA nrr, 5 years at 25"C. Left coating with a pin pore loss of adhesion due to cathodic disbonding. Right pore-free coating loss of adhesion due to electro-osmotic transport of H O. In both cases the loose coating was removed at the end of the experiment.

Vijh, A. K. Electro-Osmotic Dewatering of Clays, Soils, and Suspensions 32... 

A disadvantage of methanol, however, is the phenomenon of electro-osmotic drag" in which protons moving through the... 

Chapter 4 is devoted to single-phase heat transfer. Data on heat transfer in circular micro-tubes and in rectangular, trapezoidal and triangular ducts are presented. Attention is drawn to the effect of energy dissipation, axial conduction and wall roughness on the thermal characteristics of flow. Specific problems connected with electro-osmotic heat transfer in micro-channels, three-dimensional heat transfer in micro-channel heat sinks and optimization of micro-heat exchangers are also discussed. 

The subject of this chapter is single-phase heat transfer in micro-channels. Several aspects of the problem are considered in the frame of a continuum model, corresponding to small Knudsen number. A number of special problems of the theory of heat transfer in micro-channels, such as the effect of viscous energy dissipation, axial heat conduction, heat transfer characteristics of gaseous flows in microchannels, and electro-osmotic heat transfer in micro-channels, are also discussed in this chapter. 

Electro-Osmotic Heat Transfer in a Micro-Channel... 

Fig. 4.22 Normalized electro-osmotically driven velocity profiles as a function of z for circular tube. Reprinted from Maynes and Webb (2003) with permission...

A general case of heat transfer under the conditions of combined action of electro-osmotic forces and imposed pressure gradient was considered by Chakra-borty (2006). The analysis showed that in this case the Nusselt number depends not only on parameters z and S, but also on an additional dimensionless group, which is a measure of the relative significance of the pressure gradient and osmotic forces. 

Mala GM, Li D, Werner C (1997b) Flow characteristics of water through a micro-channel between two parallel plates with electro kinetic effects. Int J Heat Fluid Flow 18 491 96 Male van P, Croon de MHJM, Tiggelaar RM, Derg van den A, Schouten JC (2004) Heat and mass transfer in a square micro-channel with asymmetric heating. Int J Heat Mass Transfer 47 87-99 Maranzana G, Perry I, Maillet D (2004) Mini- and micro-channels influence of axial conduction in the walls. Int J Heat Mass Transfer 47 3993 004 Maynes D, Webb BW (2003) Full developed electro-osmotic heat transfer in microchannels. Int J Heat Mass Transfer 46 1359-1369... 

Capillary electrophoresis (CE) has several unique advantages compared to HPLC, snch as higher efficiency dne to non-parabolic fronting, shorter analytical time, prodnction of no or much smaller amounts of organic solvents, and lower cost for capillary zone electrophoresis (CZE) and fused-silica capillary techniques. However, in CZE, the most popular separation mode for CE, the analytes are separated on the basis of differences in charge and molecular sizes, and therefore neutral compounds snch as carotenoids do not migrate and all co-elute with the electro-osmotic flow. 

Figure 2.47 Micro mixer based on the excitation of an electro-osmotic flow around a cylinder by an oscillatory electric field (top). The bottom of the figure shows particle traces on both sides of the liquid/liquid interface with no electric field (above) and with the electric field switched on (below), as described in [145].

Top plate material Polydimethyl-siloxane (PDMS) Tube for electro-osmotic flow inner diameter length 500 pm 20 mm... 

Figure 2 Flow profiles for electro-osmotic and hydrodynamic flows.

Table 2 Additives Frequently Used in HPCE for Electro-osmotic Flow (EOF) Modification...

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