Digital simulations controlled current

Note that this equation is the same as (12.3.29). This limiting current holds only in the region of small (o. When A (= b C lcS) becomes small, the behavior approaches the mass-transfer-controlled limiting current. Results of a digital simulation of the catalytic case (83) are shown in Figure 12.4.3. Other treatments of the ErCj case at the RDE, as well as variations of this mechanism, have also appeared (84-86). The treatment of the Ej-CJ case for the RRDE by digital simulation techniques showed that the results (i.e., plots of Nk vs. XKT) are indistinguishable from those of the Ej-Ci case for first- or pseudo-first-order reactions (83). 

The shapes of the polarization curves depend strongly on the /oM ratios. It is obvious that the continuous change of the exchange current density to the limiting diffusion current density ratio for processes of the metal electrodeposition is only possible by the digital simulation. In this way, the relations between ratios, the shape of polarization curve, and the electrodeposition process control can be established. 

Controlled potential techniques have shown to be useful tools to characterize the electrochemical behavior of organic compounds. Particularly, cyclic, convolution and square wave voltammetries, controlled potential electrolysis, and digital simulation provide valuable information, which allows elucidating the electrochemical reaction mechanism, and the determination of thermodynamic, kinetic and diffusion parameters (Bard Faulkner, 2001). In addition, the square wave voltammetry is particularly a fast and sensitive technique to detect and quantify a given substrate considering its ability to discriminate against capacitive currents (Osteryoimg O Dea, 1987 Mirceski, Komorsky-Lovric Lovric, 2007). 

An extremely valuable contribution to control system design has been provided by the digital and analogue system simulations developed over the past years. It is, therefore, worthwhile to outline the basic content of the current wide range simulator which is programmed on a PACE analogue computer. 

---