Electrochemical drag

Water transport through polymer membrane including both electrochemical drag and back diffusion. 

An electrochemical method was developed by Fuller and Newman [10] based on electrochemical potential that arises across a membrane sample exposed at each side to different water activities. In that case the electrochemical drag is ... 

An H2/Air fuel cell operates at 80°C and IZOkPa. Hydrogen is supplied in a dead-end mode. If the net electrochemical drag is 0.25 molecules of H2O per proton, calculate required relative humidity of hydrogen at the inlet so that there is neither water accumulation nor drying of the membrane on the hydrogen side of the fuel cell. Explain the physical meaning of your result. 

The electrochemical stripping of ions incorporated into polymer films can also be used in the sense of release of reagents into solution 261-264) jjjg electrochemically stimulated and controlled release of drags and neurotransmitters from... 

TDM was first carried out on drags in biological samples using ultraviolet (UV) light, fluorescence, and electrochemical detection, which measured physicochemical properties of drags. Used alone, these detection methods had low sensitivity and selectivity and were soon obsolete.10... 

Ren, X., Springer, T. E., Zawodzinski, T. A. and Gottesfeld, S. 2000. Methanol transport through Nafion membranes— Electro-osmotic drag effects on potential step measurements. Journal of the Electrochemical Society 147 466-474. 

A fundamental fuel cell model consists of five principles of conservation mass, momentum, species, charge, and thermal energy. These transport equations are then coupled with electrochemical processes through source terms to describe reaction kinetics and electro-osmotic drag in the polymer electrolyte. Such convection—diffusion—source equations can be summarized in the following general form... 

Mobilization. Fluid drag can yield particle detachment and mobilization. Mobilization depends on the balance among participating particle-level forces (gravitational and electrical), the magnitudes of which are controlled by particle size, and electrochemical fluid characteristics. 

The electrochemical insertion process includes - charge transfer (red-ox reaction) by electrons and ions and -> diffusion of ions in the host to theirs sites. The inserted species can be cations (upon cathodic polarization), anions (upon anodic polarization), atoms, and molecules. Insertion of ions can be accompanied by co-insertion of solvent molecules from the -> solvation shell of the ions, which are dragged to the host together with the ions as the electrical field is applied. Insertion electrodes are highly important for the filed of - Li batteries, as most of the electrodes used in Li/Li-ion batteries are in fact insertion electrodes. Thereby, this entry concentrates mainly on Li ion insertion electrodes. 

Lu J, Rogers C, Manno VP, Philipossian A, Anjur S, Moinpour M. Measurements of slurry film thickness and wafer drag during CMP. Electrochem Soc 2004 151 (4) G241-G247. 

Here, 1 are the ionic drag coefficients of cations and anions, respectively, and are the electrochemical potentials of cations and anions, respectively, which are... 

Weng, D. et al.. Electro-osmotic drag coefficient of water and methanol in polymer electrolytes at elevated temperatures, J. Electrochem. Soc., 143, 1260, 1996. 

X.M. Ren, W. Henderson, and S. Gottesfeld. Electro-osmotic drag of water in ionomeric membranes New measurements employing a direct methanol fuel cell. Journal of the Electrochemical Society 144, L267-L270 1997. 

Ren, X. Gottesfeld, S. Electro-osmotic drag of water in poly(perfluorosulfonic acid) membranes. J. Electrochem. Soc. 2001, 148, A87. 

In this study, we have demonstrated a new electrochemical method for highly sensitive, accurate, and rapid multiplex detection of colon cancer cells response to differentiation therapy. The development of an electronic biochip array system, adjusted to biological experiments can help tailor cancer treatment to individual patients. Human colon cancer cells, HT-29, were treated with the differentiation therapy drag agents BA, AN-7, and AN-9, and the cells response was simultaneously measured on hue and compared. This microarray technology provides the ability to test on line the affect of multi-drag agents, and to tailor effective therapy to the individual. 

The growth of the bubble induces a micro-convective flow on the electrolyte that pushes each bubble from an ideal center of the surface ( active site ) in various radial directions (Figure 14.5). When each bubble attains a certain size, the buoyancy exceeds its adhesion and the bubble leaves the surface producing a drag flow. However, in the electrochemical cell, the radial and the azimuthal directions produces the opposite drag flow to the platinum surface displaying the so-called surface pressure effect. 

Many other factors have to be considered for the characterization of a turbine in a chemical or electrochemical reactor. First, the impeller pumping capacity, defined as the liquid flow, is obtained from the revolution volume of the impeller. In addition it is also considered here the circulation flux, conceived as the fluid flowable to drag by the circulation laces generated by the impellers. The renovation time—the time that the entire electrolyte contained in the vessel remains before being drawn across the impeller—has to be also considered. The circulation time is the time that taken by the electrolyte in the reactor to circulate along all the circulation laces (flux pattern of the impeller). Finally, the index of the turbulence is simply the ratio between the mean fluctuant speed in the entire reactor volume from the edge of the impeller. 

Operation mode of fuel cell is strongly determined by water balance. Water production by electrochemical process and also water transport due to proton migration and diffusion were measured with use of special complex. For MEA based on MF-4SK proton exchange membrane with hydrophobic catalytic layer an effective water drag coefficient =0.28 for air and =0.53 for pure oxygen, water diffusion coefficient trough membrane T) , =l.55x10 mVs. 

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