INDEX Current density

Hatch, G. B., Maximum Self-generated Anodic Current Density as an Inhibitor Pitting Index , III. State Water Surv., Circ. No. 91, 24 (1966) C.A., 66, 8l8l4f Herbsleb, G., Pitting Corrosion on Metals with Elearon-conductive Passive Layers , tVerksl. Korros., 17, 649 (1966) C.A., 66, 5337m ... 

Since oxidation of methanol is an electrocatalytic reaction with different adsorption steps, interactions of the adsorbed species with the metallic surface are important. Using platinum single-crystal electrodes, it has been proven that the electrooxidation of methanol is a surface-sensitive reaction. The initial activity of the Pt(llO) plane is much higher than that of the other low-index planes, but the poisoning phenomenon is so rapid that it causes a fast decrease in the current densities. The... 

If the properties of anodically grown oxides are compared to those of thermal oxides, distinct differences are observed. Anodic oxides formed in water-rich electrolytes exhibit a lower refraction index (nr< 1.4) than thermal oxides ( =1.46) [Du2]. The density of thick anodic oxides is a weak function of the current density for galvanostatic anodization and increases from 1.8 to about 2.1 g cm-3 (thermal oxide 2.2 g cm4) if... 

In-situ measurement technique of water vapor concentration in gas flow channels in PEMFCs using tunable diode laser absorption spectroscopy (TDLAS)31-36 is also shown with fundamental descriptions on its measuring principle and validity of a practical system. Localized current density and through-plane water-back transport index are obtained with variation of vapor concentration along the gas channel taken into account. Demonstrative results showing that effect of the micro porous layer (MPL) on variation of through-plane water-back transport index is shown in an operating PEMFC. 

Connection of Complex Refraction Index with Current Density... 

Once the crack is initiated, the metal surface inside the crack may be quite different from the normal surface of the metal. Thus, in the course of plastic deformation, the metal could have developed slip steps [see Fig. 12.77(c)] which contain crystallographic planes of high Miller index at which the specific dissolution rate (or exchange current density) may be larger than that at the normal metal surface. Anodic current densities of some 104 times those at a passive surface have been shown to appear at a metal surface that is yielding under stress (Despic and Raicheff, 1978). 

The interaction of ions with solvent molecules suggests a more detailed picture in which during electrolysis the cations are transporting nj+ solvent molecules into the cathode compartment and the anions nj solvent molecules out of that region into the opposite direction. The residual molecules of the solvent, which remain unaffected by the ion movement, are regarded as free , n = ni+, ni are total solvation numbers of the ions which differ from those in Chapter III. The transference numbers t[ referred to the free solvent (index ) are called true transference numbers The diffusion current density referred to the velocity v j of the free solvent results from Eq. (51) ... 

Calculated Power and Efficiency. The simplified analytical models of thermionic characteristics have been used to project the converter efficiency and power density with the barrier index as a parameter. These projections are shown in Figures 8 and 9 as functions of the emitter temperature. The dashed lines in these two figures are for a constant current density of 10 A/cm. If the current density is adjusted to maximize the efficiency at each temperature, the calculated performance is represented by the solid lines. Typical present generation themionlc converters operate with Vg near 2.0. Ignited mode converters in laboratory experiments have demonstrated practical operation with 1.85 < Vg < 1.90. Other laboratory devices with auxiliary sources of ions and/or special electrode surfaces have achieved Vj < 1.5, but usually not under practical operating conditions. 

In Fig. 13 the different electrolytes listed in Table 6 are compared to one another with respect to their throwing power, characterized by the Wagner index. Within one particular electrolyte system, the throwing power decreases with increasing current density [28, 33, 186, 187]. In comparison to the electrolytes El II and III, the throwing ability of El I, S3, and S6 is significantly lower. As a result, El I was replaced by either El II or El III in technical plating applications. 

The blocks, or elementary volumes, form the grid. The blocks are numbered with two indexes, i and j, in the horizontal and vertical direction respectively. The horizontal axes is denoted as x and the vertical one - as z. The sizes of the block along these axes are denoted as Ax and Az. The values of cp, Ci, c2 and a are located in the centre of the block and are supposed to be constant in it. The current density vector j has the horizontal and vertical components j=(jx, jz) these components are assigned to the centres of the block sides see Fig.l. Ohm s law in vector notation gives us the relation between (p and j ... 

The permittivity of a vacuum Eq has SI units of (C /J m). The specific conductivity (Tc (l/( 2-m)) couples the electric field to the electric current density by J= OcE. From the relations described in (6b), it becomes evident that optically generated gratings correspond to spatial modulations of n, , or Xg. The parameters AA, , and Xg are tensorial. This means that the value of Xg depends on the material orientation to the electric field (anisotropic interactions). In general, P and E can be related by higher-rank susceptibility tensors, which describe anisotropic mediums. The refractive index n, and absorption coefficient K, can be joined to specify the complex susceptibility when K (Xp) 471/Xp such that... 

Let us assume that in an arbitrary layer, which is denoted by index (1), a uniform electric field E = E e is given, and it is located at the xz plane. The current density in this layer is = (JiEi. 

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