Anodes 1.2 INDEX

Gradient Refractive Index Anode for High Contrast OLEDs.517... 

FIGURE 6.26 Schematic diagram of a high contrast OLED using a gradient refractive index anode. 

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 ... 

Refractive index The refractive index of the clear anodic film produced on aluminium of the highest purity in sulphuric acid is 1-59 in the as-formed condition, rising to 1-62 after sealing . 

Since the corrosion resistance of anodic films on aluminium is markedly dependent on the efficacy of sealing (provided the film thickness is adequate for the service conditions), tests for sealing quality are frequently employed as an index of potential resistance to corrosion. While it is admitted that an unequivocal evaluation of corrosion behaviour can only be obtained by protracted field tests in service, accelerated corrosion tests under closely controlled conditions can also provide useful information in a shorter time within the limitations of the particular test environment employed. 

The overall current-producing reaction can be obtained by combining the cathodic reaction occurring at one electrode (index 1 ) with the anodic reaction occurring at the other electrode (index 2 ), while the equations for these reactions must be written so that the values of n in these equations are identical (the reactions must be coupled) ... 

If measurements are made in thin oxide films (of thickness less than 5 nm), at highly polished Al, within a small acceptance angle (a < 5°), well-defined additional maxima and minima in excitation (PL) and emission (PL and EL) spectra appear.322 This structure has been explained as a result of interference between monochromatic electromagnetic waves passing directly through the oxide film and EM waves reflected from the Al surface. In a series of papers,318-320 this effect has been explored as a means for precise determination of anodic oxide film thickness (or growth rate), refractive index, porosity, mean range of electron avalanches, transport numbers, etc. 

In this context see also Refs. [83a, 83b]. Comninellis and Plattner [287,287a, 288] have developed a simple method for estimating the facility of the electrochemical oxidation of organic species based on a newly defined electrochemical oxidizability index (EOI) and the degree of oxidation using the electrochemical oxygen demand (EOD). Electrochemical oxidizability index for various benzene derivatives obtained at Pt/Ti and Sn02-ABB-anodes are listed in Table 23. 

Table 23. Comparison of the Electrochemical Oxidation Index (EOI) at Pt/Ti and Sn02- Anodes (ABB-Anode) with organic substances [45a, 287, 288]...

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... 

The dependence of PS porosity on doping density has been exploited to fabricate optical waveguides. Such structures require only a single variation of refractive index. If a p-type substrate with implanted p+ lines is anodized and partially oxidized, mesoporous lines of high refractive index are embedded in a low refractive index material. An obtained refractive index contrast between core and clad of 30% is promising for future applications [Tal2]. 

Figure 5. (A) Voltammograms on Ir and Pt low-index single crystals at 50 mV s in O.SM H2SO4. Solid curves are for Ir and dotted ones for Pt. (B) Anodic voltammograms on various iridium single crystals. (From Ref. 32.)...

This water back-transport index is expressed as the normalized through-plane water flux from the cathode side to the anode side divided by the water generation rate at the cathode. Consequently, a... 

Figure 12 under the counter-flow mode at 0.5 A/cm2. The index with the MPL is larger than that without the MPL for an index of 0-1 as depicted in Fig. 12. This result also shows that the MPL enhances water back-transport from the cathode side to the anode side. However, when the index is negative, meaning that the internal water circulation from the anode channel to the cathode channel, the index with the MPL is slightly higher than the index without the MPL. Therefore, the MPL at the cathode suppressed water vapor absorption at the anode, which is explainable by membrane hydration attributable to the MPL at the cathode. Consequently, the MPL promotes membrane hydration, leading less internal water circulation from the anode to the cathode side.

The second procedure is based on the effect of the square wave amplitude on the peak potential separation between the anodic and cathodic components of the SWV response. This separation depends on both the reversibility of the surface charge transfer (through co and Sw- Thus, by plotting the differences AEp = Epc — E pl>, with Ep c and EpA being the peak potentials of the forward and reverse currents measured versus the index potential, or AE p = Ef c — E p a with h p c and h p a being the peak potentials of the forward and reverse currents measured versus the real potential that is applied in each case (potential-corrected voltammograms), it is possible to obtain linear dependences between the peak potentials separation and... 

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). 

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