The aim of this study is to prevent the hardening of coal ash during transportation from power plants and storage. In order to prevent the coal ash from hardening, humidification and mixing with additives were applied.
As a result, (1) humidification of coal ash at 40°C with air of 50-90%RH, the hardenability of coal ash greatly decreased because sulfur trioxide on the surface of the coal ash reacted with alkaline components such as calcium carbonate by humidification, (2) miximg coal ash with lime stone is the most effective method in reducing the hardenability because it reacts with the sulfur trioxide. The addition of 1-10% lime stone is necessary to prevent hardening.

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In order to convert waste incineration fly ash (Fa) into calcium phosphates, Fa was treated with Na₃PO₄ solutions at 85°C for 24h and the resulting materials were characterized by various means. Powder X-ray diffraction, X-ray fluorescence and thermal analysis indicated that the Fa contains large amounts of CaCO₃ and Ca(OH)₂. By treating the Fa in Na₃PO₄ solution, CaCO₃ and Ca(OH)₃in the Fa were dissolved to form calcium hydroxyapatite (Ca₁₀(PO₄)₆(OH)₂: Hap). Adding NHO₃ solution in the treating solution accelerated the dissolution of CaCO₃ and Ca(OH)₂ in the Fa, leading to an increase in the adsorbed amount of PO^3-₄ and the formation of dicalcium phosphate unhydrate (CaHPO₄) and Hap. These results indicated that the calcium compounds in Fa are available for calcium source to synthesize the calcium phosphates.

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In order to optimize sphere-pack fuel pin fabrication process, internal structure of fuel pin under small particle infiltration process was observed by micro focus X-ray CT system. During the settling of small particles through the bed of large particles, some small particles are localized in the space between large particles. When small particles reach the bottom of the fuel column, they fill the space between large particles forming a complete packing layer. Sphere-pack process proceeds with the growth of the layer from the bottom to the top of the column. A unique layer is formed near the top of fuel column. In the layer, small particles completely intrude between large particles and pin wall. The structure did not change after the completion of small particle infiltration process. The formation of the unique layer was controlled by the strength of a constraint of the layer surface.

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Insights have been given into basic problems in understanding of underlying mechanisms for size and shape control of nanoparticles in liquid phases on five major topics of current nanotechnology: applicable systems of the fundamental equation for size control, limits of Nielsen's chronomal analysis in its application to growth mechanisms, contradictions involved in the aggregative growth model of monodispersed particles, a new idea on the mechanism of particle growth in W/O microemulsions, questions on the soft-template model of surfactants for the anisotropic growth of metallic nanoparticles.

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