V, 400 Hz oscillatory potential with various superimposed steady potentials (Figure , see accompanying permanent separation of colloids. The pH transients observed in experiments showed similar qualitative shape, pH values, and decay times compared to the numerical kinetic model (cf., Figure ). Figure shows the pH transients for several steady potentials applied to a sample cell with a 650 μm electrode separation. Here the pH values peaked after about 20 seconds for each applied potential and decayed to near the initial value after hundreds of seconds, consistent with experiments and simulations.