binary mixture (fructose-water, Figure 2) since a! depends only on the values of C2 and bi, where C 2 is defined as the ratio of dead volume of the bottom reservoir to the displacement.Chen and Hill (1971) have shown that there are three possible regions of pump operations. Regions 1, 2, and 3, depending on the relative magnitudes of penetration distances Lli and L2ir and the height of the column h. AS long as for the continuous pump and