Electrokinetic losses

The contribution of electrokinetic losses to the total sound attenuation is almost always negligibly small (9) and will be neglected. This opens an opportunity to separate acoustic spectroscopy from electroacoustic spectroscopy because acoustic attenuation spectra are independent of the electric properties of the dispersed system. 

However, these chemical thermodynamic considerations are important but not decisive for the technical exploitation of high temperature fuel cells. One practical important factor is the decrease in the electrokinetically determined overvoltage so that smaller losses occur in comparison with low temperature operation and, thus, higher efficiencies are obtained. Another difficulty is the direct utilization of the fuels which are produced at high temperatures... 

The suppression of fhe removal rate of TaN film could nof be fully explained through the electrochemical phenomena by chemical reaction between complexing agent and the TaN film surface. We fhought that the TaN film loss and the Cu-to-TaN removal selectivity are directly related to the electrostatic interaction and electrokinetic behavior due to chemical adsorption and steric hindrance of adsorbed organic chemical. 

Several experiments have shown that electrokinetically mediated iron mineralization is, in essence, a self-limiting process in which the current falls as an essentially impermeable (1 x 10" m/s or less) iron-rich lithilied soil mass develops (e.g. Hopkinson and Cundy, 2003 Cundy and Hopkinson, 2005). In the context of Cr(VI) stabilization, the generation of low-permeability zones, in which chemically stabilized Cr(III) is locked in iron-rich mineral phase(s), means that stabilized zones are likely to be resilient to reactive flow, with the low permeability also serving to limit potential loss of adsorbed Cr(VI) residue on the iron mineral phase(s). 

Inject sample. Sample is injected either by hydrostatic pressure or electrokinetically depending on the nature of the analyte and the sample matrix. Ideally, the injection should be followed by a second injection of separation buffer (equivalent of 1-2 s at 0.5 psi) to avoid any loss of sample into the inlet vial during the first few seconds of voltage application. This is particularly important with sample matrices that end to generate significant Joule heat. 

As mentioned before, when pressure-based sample injection is employed, the maximum injection volume must be less than the effective length of the capillary. At least 10% of the effective capillary length must remain available for separation. To inject a larger sample volume, electrokinetic injection must be employed. In most online sample preconcentration techniques, the maximum amount that can be injected without loss of separation efficiency is certainly less than the capillary volume. However, with a large volume sample injection under cathodic EOF conditions in SDS MEKC, a sample devoid of the micelle can be continuously electrokinetically injected for a volume equivalent to seven times the capillary volume without significant loss of separation efficiency under favorable... 

When spatial or time multiplexing is employed as a multidimensional separation strategy with a first dimension based on an electrokinetic separation mode, an inherent difficulty arises from the need for the first dimension separation channel to be intersected by one of more second dimension channels. Regardless of whether the first dimension separation is operated in a transient (e.g., CZE) or steady-state (e.g., lEF) mode, electric field lines extending into the intersecting channels result in dispersion of sample out of the first dimension channel, and ultimately to sample loss as diffusion... 

If AEMs are to be apphed to fuel cells for other applications (such as automotive power etc.), more temperature stable AEMs must be developed. Operation of aUcaline-membrane-based fuel cells at elevated temperature would reduce thermodynamic voltage losses due to pH differences across the AEM and would also improve the electrokinetics. Successful, stable over the long term, and being operational at elevated temperatures, all would allow application in fuel cells for the automotive mass market. 

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