Effect of some operating variables on citrate recovery from model solutions by electrodialysis
The effect of pH and temperature (straight theta) on the overall performance indicators (i.e., solute recovery, rho, and Faraday, eta, efficiencies; specific energy consumption, epsilon, solute, JS, and water, JW, fluxes) of batch electrodialytic recovery of citric acid from model solutions was assessed at different values of feed solute concentration (cSf) and electric current density (j). Regardless of the initial feed concentration used, rho and JS were found to be independent of straight theta; eta and JW exhibited a positive trend with respect to straight theta, while epsilon a negative one. At the maximum temperature tested (33 degrees C), as the pH of the feed solution was varied from 3 to 7, rho increased from 0.90 +/- 0.08 to 0.97 +/- 0.02, eta grew from 0.09 +/- 0.02 to 0.50 +/- 0.01, JS practically doubled, epsilon reduced about 8 times, but JW increased from 3 to 4 times. So, the optimal conditions for this technique are to be determined by balancing the savings in the investment and maintenance costs against the energy costs. Copyright John Wiley & Sons, Inc.
Optimization of solution concentration by electrodialysis: Application to zinc sulfate solutions
Electrodialysis is used here for concentrating dilute solutions of zinc sulfate. Product concentration is limited by salt flux and water transport, i.e. hydration water, and osmotic, electroosmotic fluxes. Then, the variation in concentration of the concentrate solution can be expressed by a relation of the form: 
 
ΔCb = Cb0(k1x + k2xX)/(k3x + k4xX) where the variable x is either the surface, or the number of elementary compartments. It can also be the time, or the current density. Optimization with respect to time shows that high concentration factors are obtained with an apparatus for which the product of the exchange area to the inverse of the channel width is high. Experimental results agree with this analysis in the case of ZnSO4 aqueous solutions.
Representation of systems disturbed by wide band noise
In this paper, a method of handling and working with wide band noise is developed. We represent wide band noise as a distributed delay of white noise and use it to reduce a nonlinear system disturbed by wide band noise to a nonlinear system disturbed by white noise. An application of this reduction to a nonlinear filtering problem under a wide band noise disturbance is discussed.