Mass transfer coefficient ku was measured over a range of flow rates of gas Ug=0-100 cm s"1 and liquid [7^=0.05-25 cm-s"1 in a column packed with spheres of three different diameters d=2.8-12.7 mm. The systems used were the dissolution of benzoic acid in water and diffusionlimited oxidation of brass with dichromate ion in sulfuric acid solution. The effect of Ug on ku is not found at all in gas continuous flow, is the greatest in pulse flow and becomes less significant again in dispersed bubble flow. The value of ku increases rapidly around the transition from gas continuous to pulse flow. The enhancement factor p (=ku in two-phase flow/ kts in single-phase flow) increases from 1.2 to 2 with increasing d in gas continuous flow while it equals the reciprocal of liquid holdup in pulse and dispersed bubble flows. A liquid-film analogy in gas continuous flow and a single-phase analogy in pulse and dispersed bubble flows are proposed and the experimental results are examined in the light of them.

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Sevoflurane anesthesia attenuates glucose-induced insulin secretion without affecting basic insulin secretion, while propofol anesthesia enhances insulin secretion. Propofol anesthesia exaggerates insulin-resistive conditions, whereas sevoflurane anesthesia dose not impair insulin sensitivity; there may be a possible association of TNF-α with insulin-resistive conditions under propofol anesthesia.