An air bubble that passes through a horizontal interface from a lower layer of Freon‐113 to an upper layer of aqueous glycerol forms a two‐phase bubble in the upper layer as a result of entrainment of a certain volume of Freon‐113 from the lower layer. The volume of entrained Freon‐113 and the rise velocity of such a two‐phase bubble have been measured. The former increases with an increase of the bubble size irrespective of the viscosity of the upper liquid. The latter is somewhat lower than that of a normal air bubble of the same size.

In addition to the two different condensation patterns revealed respectively in n‐pentane (bubble)/glycerol and water (bubble)/silicone oil systems in the authors' previous study (1979), a third pattern has been found in methanol (bubble)/silicone oil system: a condensate appears at the rear part of the bubble surface as several blunt drops, turns into a conical tail through coalescence to each other, and finally drops out from the bubble. The possible mechanism as well as the heat transfer characteristics of the condensation process are discussed.

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Homogeneous BaTiO3 nano-sized powders were successfully prepared by spray pyrolysis using multiphase plasma under the air atmosphere. Particle size, morphology, crystal phase and crystallinity of as-prepared powders were characterized by SEM and XRD. The effect of starting precursor solution on the formation of nanoparticles was investigated. The use of Ba/Ti aqueous solution derived from malic acid led to formation of cubic BaTiO3 nanoparticles with 50 nm size.

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