Current densities different

Figure 5. The relative change in the halogen concentration as a function of exposure time for two current densities differing by 2.5 orders of magnitude.

For the time domain responses of the CPE, the current density difference (A/)/scan rate (v) relation is expressed by the following power-law during the potential scanning199... 

Figure 14. Dependence of the current density difference Ai between anodic and cathodic peak currents of the cyclic voltammograms (CVs) on the scan rate v for carbon specimens A (o), B ( ), and C (A). Reprinted from Ref. 17, (2006), with permission from Elsevier.

Current density difference between anodic and cathodic peak currents of the cyclic voltammogram Inverse fast Fourier transform International Union of Pure and Applied Chemistry... 

Hydrogen evolution rate on the tin surface increases when tin is coupled with inert platinum. The observed increase in Fig. 6.6 results from the exchange current density difference of the coupled metals. The intersection between the tin dissolution polarization curve and the polarization curve for hydrogen evolution on tin results in fcorr.Sn- When equal surface area of tin (1 cm and platinum (1 cm are coupled, the sum of the rates of hydrogen evolution reactions on both metals is equal to the total rate of hydrogen evolution. 

Color Index (common) name Applied current density Different units reported Percentage of TOC decay Not determined initial COD mM concentration Specific charge passed (Ah dm ... 

Electrical similarity exists between two units when corresponding potential and current density differences bear a constant ratio. The two sizes of cells will require the same cell voltage and current distribution. The criterion often necessitates a constant interelectrode gap on scale-up. A variety of dimensionless groups have been proposed as similarity criteria. One for example is the so-called polarization parameter P, defined as ... 

Fig. 8.21 Current density differences between fast and slow sweep rate polarisation curves and stress corrosion cracking suspectiblity as a function of potential for a C-Mn steel in nitrate, hydroxide and carbonate-bicarbonate solutions...

The RG theorem was proven in two distinct parts. In the first part (RGI), one shows that the corresponding current densities differ. The current density is given by... 

If the Taylor expansion of the difference of the two potentials about = 0 is not spatially uniform for some order, the Taylor expansion of the current density difference will then be nonzero at a finite order. Thus, RGI establishes the fact that the external potential is a functional of the current density,... 

This correction function was calculated for different kinds of excitation coils, like circular coils without ferrite core, spiral coils, double-D coils and a sheet inducer. For this purpose the eddy current density was determined for frequencies between 10 and 1000 Hz and for depths between 0 and 30 mm. 

The simulation of the actual distortion of the eddy current flow caused by a crack turns out to be too time consuming with present means. We therefore have developed a simple model for calculating the optimum excitation frequencies for cracks in different depths of arbitrary test sarriples Using Equ. (2.5), we are able to calculate the decrease in eddy current density with increasing depth in the conductor for a given excitation method, taking into account the dependence of the penetration depth c on coil geometry and excitation frequency. 

For a more general reaction of the fonn Ox + ne Red, with differing concentrations of Ox and Red, the exchange current density is given by... 

The overpotential is defined as the difference between the actual potential of an electrode at a given current density and the reversible electrode potential for the reaction. 

The first semiconductor lasers, fabricated from gallium arsenide material, were formed from a simple junction (called a homojunction because the composition of the material was the same on each side of the junction) between the type and n-ty e materials. Those devices required high electrical current density, which produced damage ia the region of the junction so that the lasers were short-Hved. To reduce this problem, a heterojunction stmcture was developed. This junction is formed by growing a number of layers of different composition epitaxially. This is shown ia Figure 12. There are a number of layers of material having different composition is this ternary alloy system, which may be denoted Al Ga his notation, x is a composition... 

If equations 2 and 3 are combined, relationships between the average current density J, current I, surface area to be machined A, appHed potential difference, gap width h, and electrolyte conductivity are... 

Electrolytic plating rates ate controUed by the current density at the metal—solution interface. The current distribution on a complex part is never uniform, and this can lead to large differences in plating rate and deposit thickness over the part surface. Uniform plating of blind holes, re-entrant cavities, and long projections is especiaUy difficult. 

A problem that affects the accuracy of the prediction of plating thickness is in estimating the actual current density. Current is not evenly distributed over the surface of the part being plated, rather, it takes the path of least resistance. Current also concentrates on sharper points, corners, and edges even the shape of the plating tank can have an influence on the current distribution. The difference in current and, subsequendy, the plate thickness distribution, is minimal when geometrically conforming anodes are part of the system, but this condition is not often achieved. 

---