Current-voltage characteristics evaluation

The numerical methods [32, 33, 34, 35, 36, 37] developed for the analysis of experimental polarization curves described by the current-voltage characteristic (2) with the aim of determining the electrochemical parameters a, /3 and h, are of considerable importance in the field of basic research as well as in corrosion rate monitoring. They permit, in fact, a more objective evaluation of these quantities with reference to a given potential difference interval AE, removing the degree of subjectivity that is inherent in the graphic determination of the Tafel slopes. 

Thus there are a lot of two-phase flow simulators developed. However the evaluation of the simulators is insufficient, because the comparison between practical cell operation and its simulation has been focused on the level of only current-voltage characteristics. To get the reliability on the simulation, a comparison... 

The device structures, operations of OFETs, and estimation of the FET characteristics from current-voltage curves have been summarized previously [2]. The important parameters to evaluate the quality of an OFET are carrier mobility /d), on/off ratio, and threshold voltage 8 performance of the transistor... 

Having obtained T(E,Vt), we proceed with the evaluation of the current-voltage, I-V, characteristic of the tube utilizing the following formula for calculating the current (24)... 

The first report of an all-SiC, three-phase dc-ac inverter was presented by Seshadri et al. [17] in 1999. Although Seshadri s inverter used SiG GTOs and p-/-n diodes, it was operated at ambient temperature and at voltage and current levels so low that the authors were unable to ...determine typical switching characteristics of the individual SiG components. From the standpoint of technology development, there exists a need to evaluate SiC technology under relevant circuit stresses. 

A number of empirical equations have been suggested (e.g. Shepherd formulae) for certain types of cell which give cell voltage as a function of discharge depth, current, etc., once a number of constants characteristic of the cell discharge have been evaluated. 

In order to evaluate the impact of the relative amount of fuel crossover upon the cathode performance, and thus the overall cell voltage, it is necessary to compare the crossover current densities, rather than on a molar basis. In Fig. 1.50, the crossover current densities are compared for ail three fuels, dimethoxymethane, trimethoxymethane. and methanol, of varying concentrations. When the behavior of TMM is contrasted with that of methanol, it is apparent that a 1.0 M methanol solution displays similar crossover characteristics compared with a - 0.3 M solution of trimethoxymethane. This trend is understandable in that one trimethoxymethane molecule is converted to four carbon dioxide molecule in an overall 20 electron electro-oxidative... 

Fill Factor - The ratio of a photovoltaic cell s actual power to its power if both current and voltage were at their maxima. A key characteristic in evaluating cell performance. 

To evaluate the sensing characteristics of the conjugated polymer or its nanocomposite using four-probe technique of resistivity measurement, four electrical contacts are made on the layer by copper wire and silver paste. Subsequently the change in voltage between two middle probes on the sample layer is measured in analyte environment and the results are reported in terms of the change in resistivity of the sample at constant current applied trough terminal two probe. The resistivity of the sample layer can be calculated by the equation [12] ... 

The evaluation was conducted with all the failures subject to consideration as these occurred within the period of monitoring of 41 hours and 27 minutes. The period included both the measurement of particular load characteristics as well as long-term operation at rated power (the supply of electric power into the distribution network via inverter). The NEXA system experienced twelve failures within the period monitored. There were five failures due to the low pressure of fuel at the fuel cell system inlet, four failures due to high stack current and one failure caused by the low stack voltage (Fig. 6) and there were two failures due to causes within the distribution network (or the inverter). The latter failures did not induce the automatic deactivation of the fuel cell system yet only temporary interruption of the supply into the distribution network. 

In Eig. 22.14a, the changes in the currents at 1.45 V of the characteristic cycles throughout the 10,000 cycles are presented. The first observation is that the activity of the OER catalysts steadily decays at the rate of 3 % per 1,000 cycles. The second is that the OER currents form three distinctive bands. The upper band contains only ten points, the first point of each of the ten scans immediately following the evaluation of the surface area. During these measurements the electrode potential is close to 0 V, and therefore, the electrode surface is fully reduced, i.e., regenerated. The middle band contains the partially regenerated surfaces, after the voltage is dropped to 0.7 V (see the example in Eig. 22.13b). There are 20 of these points per... 

Another way to calculate the residual capacity of a traction battery is based on the evaluation of voltage and current. Both parameters have to be measured continuously, and the typical performance characteristics of a battery type have to be inserted in the calculation process. Often this type of capacity indication is part of the electronic control of a vehicle. 

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