Some problems in the preparation process of highly loaded Coal-Water Mixtures(CWM) were discussed. The optimization of particle size distribution based on the two-stage pulverizing process was examined to attain stability in storage and fluidity in transport. The optimum particle size distribution obtained in this work was difficult to realize by using the actual pulverizer. Therefore, a possibility of a semi-optimum particle size distribution was sought in consideration of the experimental results of viscosity measurements of highly loaded CWM. A thixotropy model, in which the yield stress was adopted as a structural parameter, was proposed in connection with the stability problem of CWM storage. The model was able to explain well the buildup and breakdown processes of network structure in CWM. It was shown that the yield stress at the final stage of network structure buildup could be adopted as the index for the evaluation of stability in CWM storage.

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The taste of boiled rice depends primarily on various mechanical properties of boiled rice grains and the internal structure is responsible for these mechanical properties.
(1) The time dependency of strain in compressed boiled rice, a Japanese delicacy known as“oshi-zushi”, during its formation process was studied by applying a given compressive stress. Most of the properties of compressed boiled rice grains could be explained by a mechanical nine-element model, and the components of the strain in each element were determined by the thickness of boiled rice grains before compression, the compressive stress, and compression time.
(2) Twenty-four types of domestic rice were examined for their mechanical properties. There was a strong correlation between the taste category and the experimental results, including the initial compressive modulus, adhesive energy, total strain, and relaxation time.
(3) Deterioration of the taste of boiled rice with the retrogradation time and its physical factors were studied. Generally, the change in the degree of crystallinity obtained from an X-ray diffraction intensity diagram correlated well with the change in the compressive energy obtained from compression experiments.
(4) Changes of structure and mechanical properties were studied in the gelatinization process of suspensions of starch granules from white potatoes, non-glutinous rice, and non-glutinous rice pretreated by NaOH, and that of gel of starch granules from non-glutinous rice. Before the heat treatment, four-leaf clover images were seen in the light scattering photographs. As the gelatinization proceeded, a maximum appeared in the viscosity-time relation. Streaks and speckles were observed in the succeeding light scattering measurements.
(5) Furthermore changes in the structure and mechanical properties of starch granules from white potatoes during the gelatinization process were studied. The light scattering photographs and polarization microscopy during the heating process demonstrated that there was a relationship between the disintegration characteristics of granules and change in viscosity. Also, there was a definite difference in the thermal resistance between the surface layers and the inner part of the same starch granule.

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Deformation process of amorphous polymers was investigated from a microscopic view-point by employing several new techniques. The acoustoelastic properties of a brittle polymer, poly (methyl methacrylate)(PMMA), were studied using Brillouin scattering and ultrasonic techniques. The sound velocity showed a large softening along the stress direction, and its anisotropic angular dependence with respect to the stress direction was determined. The origin of this phenomenon was attributed to the formation of submicro-cracks with lens-like shape, based on results of small angle x-ray scattering (SAXS) and acoustic emission (AE) measurements.
Furthermore, the hypersonic sound velocities in two kinds of ductile polymers, polycarbonate (PC) and polyethylene terephthalate (PET), were investigated by Brillouin scattering. These two materials exhibited a decrease in sound velocity when stress was applied, but the degree of softening as well as its angular dependence were much smaller than those of the brittle polymer, PMMA. Close correlation between these acoustic properties and the formation of submicrocracks was elucidated, and the difference in the anisotropy in the softening of ductile and brittle polymers is discussed in terms of the shape and density of submicrocracks.
Time-dependent SAXS measurements were also conducted with PMMA at constant strains to study the micromechanism of the stress relaxation phenomenon. The application of strain induced rapid nucleation of submicrocracks. The correlation between the increase in submicrocrack concentration and the relaxation modulus was clarified. These results suggest that in brittle amorphous polymers such as PMMA, the formation of submicro-cracks plays a decisive role in the stress relaxation phenomenon.

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The Rheopexy or hardening property of Coal-Oil-Mixture (COM) without any additive was examined. Measurements were carried out using the intermittent dynamic method, which employs dynamic measurements intermittently instead of the 2nd (low shear) step of the double-step shearing test, after COM has been subjected to high shear to reduce the viscosity to the steady value. By this method, the increase of viscosity under the state of standstill could be measured. This method is available for the systems in which the rheological properties vary very slowly.
The COM becomes over 10 times harder than the initial state and the increase of dynamic viscosity much depends upon temperature; the higher the temperature is, the slower the hardening is. At temperatures higher than 27°C, it is observed that the hardening speed increases much at a certain time, although the increase is hardly detected at lower temperatures.
The double-step shearing tests were also carried out. At low temperatures, the viscosity showed a sigmoidal increase with time in the low shear region.

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An equation for the cohesive powder discharge from a cylindrical vessel (bin) is derived theoretically from the force balance for falling powder. It is assumed that a cylindrical block of a certain height is formed at the bottom (orifice) of the cylindrical vessel and moves out from the vessel. The block height is calculated from a dynamic force balance and a discharge equation is derived for the falling block. The equation gives a velocity profile of periodic discharge of powder. The result is similar to that by Tanaka et al., in which the motion of powder was analyzed by using different values for the static and the dynamic Rankin's coefficients.

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