The formation and growth mechanisms of germanium oxide ultrafine particles in a flame were experimentally investigated by means of TEM observation. GeO particles were initially formed at the lower part of the hydrogenoxygen diffusion flame and then evaporated as the temperature increased in the flame. In case of low concentration of raw materials, GeO particles was entirely evaporated and then appeared again as GeO₂ particles through homogeneous nucleation. On the otherhand, in case of high concentration of raw materials, developed aggregates of GeO particles were oxidized from the peripheral portion accompanied by shrinkage due to the evaporation of the GeO.
The formation and growth mechanisms of ultrafine particles in a flame were discussed by comparing germanium oxide particles with the silica particles reportted in the literature.

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The fabrication of a metal-ceramic gradient composite was studied to provide a fundamental idea for manufacturing functionally gradient materials in which chloride reduced metallic particles were infiltrated within a ceramic packing. The experiment using nickel chloride and alumina packing proved that the mixtures formed well controlled compositional gradient profiles. The infiltration process was successively simulated with the filtration theory which allowed the design of the optimal gradients. Attention has also been given to control designed gredients by using multi-layer packing composed of a different particle diameter.
The mixing state of the compositional gradient mixture was evaluated by making use of the quality of mixing derived from information entropy theory. The mixing calculated from the nickel images observed under EPMA proved that the infiltration of chloride reduced particles could fabricate compositional gradient mixtures with a satisfactory amount of homogeneous mixing.

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The encapsulation of magnetite particles was carried out by the use of heterogeneous polymerization in water in the presence of the particles, an anionic surfactant being adsorbed. The anionic surfactants used prior to polymerization were sodium dodecyl benzen sulfonate and sodium dodecyl sulfate, and the coating polymer was polymethyl methacrylate. The magnetite particles were found to be uniformly covered with polymer film due to the selection of a suitable concentration of the surfactant.
The magnetic particles encapsulated with polymer obtained in this work were also applied to the support of an immobilized enzyme. The experimental results of enzyme immobilization and enzyme reaction demonstrated that the magnetic particles prepared by this encapsulation process were sufficiently capable of application as the magnetic support of a immobilized enzyme.

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Graphical design methods for various types of closed circuit grinding systems including plural mills and classifiers are dealt with on the basis of mathematical analyses. The systems involving one mill together with single or plural classifiers (Figs. 3 and 7) have the same characteristics as the standard type (Fig. 1) except for the circulating load, which should be equal to that of the standard type plus one if the same product size distribution is required. This means that those types are superior to the standard type with respect to capacity, while, systems involving two mills (Figs. 4 and 6) are characterized by alterations in the size distribution of the finished product. Figs. 2 and 5 are useful for designing those circuits without tedious calculations.

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The pulverizing behavior of coals in organic solvents has been studied by a homogenizer-type pulverizer. The pulverized coal powder exhibited a particle size distribution consisting of coarse and fine particles divided at around 70μm. Illinois No. 6 coal was pulverized easily in solvents such as toluene and hexane which hardly swelled the coal, but it was not easy to pulverize in solvents such as acetone and ethanol which swelled the coal. The pulverizing characteristics also depended on the coal rank. The low rank coals, Wandoan and Wabamun, were hard to pulverize in toluene. Vitrinites and inertinites were condensed in the fine and coarse particles, respectively.

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