Nickel concentration profiles were studied for impregnated nickel/alumina catalysts prepared by impregnating two types of spherical aluminas with nickel (II) chloride aqueous solution and applying a wide range of postimpregnation drying conditions. Migration of nickel (II) ion towards the outer surface of alumina occurred during post-impregnation drying. The fraction of migrated nickel (II) ion increased with increase of the constant drying rate, and was held at a constant value, 0.5, at values

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... of the constant drying rate larger than 2 x l0~4kg-m~2-s~1. Amodel of solute migration during post-impregnation drying, combining solution movement by a capillary force with solute diffusion, was proposed. The observed nickel concentration profiles of the nickel/alumina catalysts showed good agreement with the results calculated by the model over the whole range of drying conditions. Kinetic behavior of a temperature-sensitive water-absorbing gel was analyzed experimentally by using a newly developed water-absorbing polyvinylmethylether gel (PVMEG).The gel showed a volume change phenomenon responding to a temperature change across the temperature of 310 K. It swelled and shrank respectively below and above the transition temperature. Asimple mathematical model for the kinetic behavior of the gel is presented and it is found that the simulated behavior of the gel fits very well with the experimental results by employing appropriate values for the parameters included in the model.