Yttria coated silica nano-particles were fabricated by a sol-gel method, and the yttria-silica adding effect for BaTiO₃ on a dielectric property was investigated. The sizes of mono-dispersed silica particles prepared were 20nm and 50nm, and these silica particles were coated with the yttria thin layer using yttrium nitrate aqueous solution. Yttria coated silica particles were successfully obtained in sizes of 29nm and 84nm. These yttria-silica particles were mixed with commercial BaTiO₃ powder, and a sintered pellet was synthesized by a conventional sintering method in order to measure the dielectric property. The dielectric anomalies were suppressed for the specimen using the 29nm yttria-silica particles, but they were intact for the specimen using the 84nm yttria-silica particles.

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In the negative pressure system of pneumatic conveying, the authors previously proposed a highly-efficient and constant feeding system of a powder, which was equipped with an injection pipe at the center of the suction nozzle. In this paper, we examined the effect of insertion depth of injection pipe into the powder bed from the tip of the suction nozzle. As a result, it was found that the optimum insertion depth which gives the highest nozzle efficiency and constant feeding exists for a given condition. The powders behavior near the injection pipe at a different insertion depth was identified through the powder flow visualization.

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TiO₂ nanoparticles supported on aluminosilicate particles modified with cationic surfactant by simply mixing them in water could protect resin from photocatalytic decomposition while decomposing acetaldehyde via photocatalic reaction. When anionic polymer dispersants with different structures and molecular weights were adsorbed on TiO₂ nanoparticles for the improvement of decomposition efficiency, the TiO₂ nanoparticles supported on aluminosilicate particles modified with cationic surfactant exhibited protection effect of resin, depending on the structure and molecular weight of anionic polymer dispersant. This trend was not observed for the TiO₂ nanoparticles dispersed by anionic polymer dispersant. The interaction between TiO₂ nanoparticles and aluminosilicate surface was analyzed with the colloid probe AFM method. The protection effect of resin appears when a decrease in the adhesive force and weak repulsive force were observed.

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