Novel technique to prepare calcite hollow particles controlling heating process of vaterite hollow particles as base particles has been developed. The vaterite hollow particles, whose shell surface consists of nano-sized particles, were previously synthesized by dissolving of carbon dioxide gas in calcium chloride aqueous solution. Vaterite transforms into calcite phase at near 500℃. Activation energy of the transformation calculated by Arrhenius plot indicated that transformation of the vaterite hollow particle to calcite phase successfully occurred. With increase in heating temperature up to 600℃, surface roughness became smooth. However, spherical shape and hollow structure remained. In addition, the calcite hollow particle showed excellent morphological stability after immersion in water for one month.

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In order to determine the preparation time for slurry in ceramic manufacturing processes, the effect of the conformation of ammonium polycarboxylate, an adsorbed anionic polymeric dispersant with a molecular weight of 8000～10000, on the dispersion stability of the slurry was investigated. The slurry preparation time was varied and the effect was investigated using and hydrostatic pressure measurement. The results of the investigation showed that the conformation of adsorbed polymers changed with time from random coil to fibril-like and that it took several days for the polymers to relax completely in the slurry. Furthermore, the dispersion state of the slurry changed with the relaxing of the conformation of adsorbed polymers. The results showed that the stretching of adsorbed polymers contributed significantly to the dispersion state of the slurry. The optimum conditions of polymers for the preparation of the slurry are also discussed.

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The use of vibrations and an external electric field for triboelectrically charging particles has been studied both theoretically and experimentally. The condenser model was applied to formulate particle charging caused by repeated contact with a surface. In this experiment, particles were fed from the top of an inclined vibration plate. The particles could travel on the surface, and they were then dropped from the plate. The charge on the particles was measured using a Faraday cup. It was found that the particle charge depends on the inclination angle, electrode length, electric field strength, vibration direction, and material type. The experimental results agreed well with the theoretical results, showing that this method is suitable for characterizing and controlling the particle charge.

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Dry dense medium separation using a gas-solid fluidized bed was applied to separate lump coal for dry coal cleaning. A mixture of zircon sand and silica sand was used as the fluidized medium. Float-sink experiments using a cylindrical column indicated that fluidizing air velocity affects the separation efficiency ; the cause was discussed considering density-segregation of the medium and fluidization intensity near the bed surface. Continuous separation experiments were conducted on lump coal in the size range of +11.1～31.5 mm in the fluidized bed with medium density of 1650 kg / m³ and feed rate of 50 kg / h. Comparison of the feed rate and the recovery rate indicated that the feed and the recovery were in equilibrium after 10 minutes of operation. The experiments resulted in nearly perfect separation; the mass percentage 69.4% of floaters was almost same with the value 68.7% of lump coal with density less than 1650 kg / m³. Measurements of calorific value and ash content indicated that the separator produced an upgrade in calorific value of +2441 kcal / kg and reduced the ash content by 59.2%.

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A two-dimensional direct numerical simulation is performed in a particle-laden turbulent flow to investigate effects of a parcel modeling on characteristics of particles' dispersion, fluctuation velocity of ambient turbulence and scalar diffusion in a turbulent mixing layer. Two parcel models in which each parcel has the same volume (volume fixed model, VFM) and represents the same number of particles （number fixed model, NFM） are discussed by comparing with directly tracking one by one particle without a parcel model as a referred case (reference case, RC). In consequence of the simulation, the spatial distribution of the dispersed particles for NFM shows a good agreement in comparing with RC. While spatially skewed distribution appeared for VFM. Fluctuation velocity distribution is overestimated for both VFM and NFM in comparing with RC as the number of particle represented by one parcel is increased and subsequently scalar diffusion is overestimated in present numerical conditions.

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In the tabletting process, we occasionally face tabletting troubles which are obstacle to assure quality of tablet. Generally, medicine including tablet was required high level of quality, so we have investigated to prevent tabletting troubles from taking place from various aspects. In this study, we focused on surface affinity between punches for tabletting and formulations, cohesion of formulations. Distance of surface free energy was used as the index of surface affinity. Porosity was used as the index of cohesion. When polar component of surface free energy of punches was low, adhesion of the formulations to punch was controlled by surface affinity. When polar component of punches was high, adhesion to punch was controlled by cohesion of formulations. Factors affecting the adhesion were different depending on the system.

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In this paper we have reviewed the granular flows and the piles which were predicted in a flat-bottomed hopper and bin based on three-dimensional numerically empirical constitutive relations using Smoothed Particle Hydrodynamics (SPH). The constitutive equations for the strain rate independent stress have been obtained as the functions of the Almansi strain. The constitutive equations cover the elastic and the plastic regions including the flow state and represent the friction mechanism of granular material. The good agreement between the calculated and the experimental results suggests that the constitutive relations and the simulation method would be applicable for predicting granular flows and pile formation with complex geometry including free surface geometry.

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By mixing with polymer and inorganic substances in a molecular level, organic-inorganic hybrids which have both functions derived from each component can be obtained. We can also tune the properties of the materials by changing the contents or types of organic components. In this review, we survey the series of studies on organic-inorganic hybrids. The design strategy and the applications for the hybrid materials are described. Moreover, we also present the polyhedral oligomeric silsesquioxane （POSS）-based functional materials. Unique characteristics originated from the structural features of POSS are explained.

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It has been handed down from ancient that Korean loess mined in natural is very beneficial to human health. This paper presents the physical and chemical properties of loess mined in Korea to interpret the benefit which is mainly attributed to effect of far-infrared rays emitted from the honeycomb structure.
The paper subsequently introduces a developed process to manufacture various bio-products from loess in consideration with the properties and application to enhance and maximize the benefit. Evaluation of customers using the bio-products are summarized and discussed from comprehensive view points including powder technology.

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