Large amount of thermal energy storage is essential for proceeding with further energy saving and contributing to environmental issues. The long term of weekly, monthly and seasonal thermal energy containment is useful to link between urban thermal energy demands and thermal energy sources-heat exhaust from industries, incinerations, power generations, air-conditioned buildings and other social infrastructures, and various natural heat sources such as seasonal warm and cold temperatures and solar energy. While we have to consider that we have both global limited resources-fossil fuel resources and environmental resources which is indispensable for human life, we have to continue our engineering efforts to establish the social structures of energy circulation by putting an energy source to joint use of industries and urban life through cascade use of thermal energy by each temperature level of thermal demands. Thus total energy consumption will be decreased among industries, social capitals and urban life. Now that huge thermal energy storage systems are not feasible to build on the ground, Underground thermal energy storage system (UTES) is one of the best effective solutions to the above issues, requiring us further engineering development about analysis technology on thermal analysis of underground soil behaviors and heat transfers, underground soil structure survey, underground thermal energy storage systems, low cost bore hole construction technology, underground heat exchanger technology, underground water movement control, more progressed heat pump technology, system integration of effective thermal energy consumption and storage types and peak load shavings, system operation and control technology and environmental evaluations. UTES is able to be combined with application of geo-thermal energy. Research and development efforts are continued to provide the solutions to above engineering subjects.

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The author suggested a measurement method of crack tip position in a previous paper. This method utilizes the polarity of first motion of diffracted P-wave at a tip of a crack, and this has the advantage of independence from effect of frequency of P-wave. The polarity of first motion of diffracted P-wave is decided by the incidence and the diffraction angle at a tip of a crack. The relationship of these two angles is influenced by only Poisson's ratio. In order to measure a crack tip position with high accuracy, it is necessary to clear the effect of Poisson's ratio. In the present paper, relationship between the first motion polarity of diffracted P-wave and a crack tip position and a crack angle was studied, and the effect of Poisson's ratio on the relationship was mentioned. The main results obtained from this study are, 1) According to the increase of Poisson's ratio, displacement of a change point of first motion polarity of diffracted P-wave increases. 2) Regardless of the crack tip position and the crack angle, the smaller Poisson's ratio becomes, the less Poisson's ratio effects on displacement of a change point of first motion polarity. 3) According to the decrease of Poisson's ratio, error of the analysis increase. 4) Replacement of transmitters and receivers according to the crack tip position and the crack angle enables measurements with a high accuracy.

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Hydrofracturing is widely used for stress measurement because of its simplicity and high applicability to great depth. In the conventional hydrofracturing, supposing axi-parallel fracture plane in intact rock, the minimum stress σh in the plane normal to hole axis is calculated from the shut-in pressure Ps , and the maximum stress σH from breakdown pressure Pb or re-opening pressure Pr. But it has been pointed out that σH is less reliable because breakdown criterion depends on water permeation, and reopening is difficult to detect and vague in its mechanism. So it would be helpful if one could get information about σH from other than Pb or Pr. In this paper, the effect of stress difference (σH-σh ) on the probability distribution of the azimuth of vertical fractures is regarded as a new source of information about σH. Though the azimuth of fracture has been thought to coincide with that of maximum stress σH, one can easily expect that the fractures' azimuths would randomly scatter in direction when stress difference (σH-σh ) is small. The distribution of fracture azimuth, therefore, possibly provides the information about σH. In order to deal with such azimuth distribution caused by strength variation from location to location, this paper adopts the weakest link theory to investigate the breakdown phenomenon probabilistically. Based on the theory, the probability of breakdown and p. d. f of fracture azimuth are deduced, and the mean and 90 % confidence interval of Pb (or tensile strength T) and 90 % confidence interval of fracture azimuth are numerically calculated. From the results it was found that those calculated values are closely related to the stress difference or anisotropy providing new information about σH. This approach of stress estimation has been applied to in-situ test at a granitic rock mass with scarce joints.

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It is anticipated that dynamical responses to changes of air supply become more complicated in a large-scale air-lift pump. Then it is inevitable to grasp unsteady flow characteristics in air-lift pumps for safety operations of the systems. Therefore the purposes of this study are to obtain safety operational conditions for air-lift pumps of lifting marine mineral resources such as manganese nodules from deep-sea floor to a mining ship. The numerical method was applied to an air-lift pump of 5,000 m depth. In this paper, we discuss especially the unsteady flow characteristics of gas-liquid two-phase flow in beginning and increasing of air supply, in increasing and reducing of back-pressure, and in stopping of air supply.

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The pyroclastic deposit in Kusu formation in Kusu, Oita prefecture was surveyed. Average particle sizes in the collected five areas range from 11 to 150μm. Particle size of the upper level in the pyloclastic deposit was smaller than that of the lower level. Main constituents of minerals in the samples were volcanic glass, feldspar, hornblende and quartz. Two kinds of upper level samples were separated by elutriation method to three size fractions of 5-10μm (S), 10-20μm (M) and 20-45μm (L), of average particle diameters of 9μm, 18.5μm, 28μm, respectively. Particle densities of samples were 2.35 g/cm3 in average. The separated samples were heat-foamed for a few seconds at 1,000 °C in a furnace that was designed for the heat-treatment of small size particles. Expanding ratios of the partially foamed S samples after heat treatments were determined to be from 1.11 to 1.21, and the particle densities from 1.95 to 2.12 g/cm3. Expanding ratios of the foamed L samples ranged from 2.65 to 2.66, and the particle densities from 0.88 to 0.89 g/cm3. Floating part in water of the foamed S samples was smaller in mass-ratio of less than 2 %；however, that of the foamed L samples was relatively large, from 56.8 % to 61.5 %. The shapes of the foamed particles were almost spherical.

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The Oheyama plant of Nippon Yakin Kogyo Co., Ltd. produces ferro-nickel granules by the Oheyama Process (the world's only method for smelting siliceous nickel ores with a rotary kiln) for self-consumption to make finished stainless steels in Kawasaki plant. Siliceous nickel ores imported from New Caledonia, Indonesia and Philippines are composed of various minerals and their chemical compositions largely vary depending on mines as well as working places, which causes smelting operations very vulnerable. Constituent minerals of New Caledonian ores were investigated by X-ray diffraction method to understand the properties of the siliceous nickel ores and the following results were obtained. (1) Main constituent minerals are garnierite, serpentine, goethite and silica. (2) Garnierites are consisted of such types as 7 A°, 10 A°, 14 A° and 12 A° which represent X-ray reflection positions from the base planes of phyllo-silicates, while serpentines are consisted of 7 A° and 14 A°. (3) Ni in the ores is concentrated in phyllo-silicates such as garnierites and serpentines, while Fe is concentrated mainly in laterite ore whose main constituent mineral is goethite. (4) A good relationship between Ni content and crystal structure is observed.

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The kinetic behavior of oxidation of impurities (Zn, Sn and Pb) in liquid copper was investigated by blowing air onto the liquid copper surface. The oxidation of only Zn and Sn proceeded at the early stage of experiment. As Zn and Sn contents decreased, the oxygen content in copper increased and then the oxidation of Pb started after the oxygen content reached some critical value. The oxidation rates of impurities and the formation of Cu2O-based slag were promoted with increasing the blowing rate of air. Lower temperature favored the removal of Zn and Sn, but it was difficult to lower the contents of Zn, Sn, and specially, Pb down to less than 0.01 mass % only by blowing air. A kinetic reaction model was developed based on two film theory. The experimental results were confirmed to be interpreted by this model.

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As a fundamental study for systematic and comprehensive understanding of copper and nickel smelting processes from a standpoint of thermodynamics, the phase equilibrium between the FeOX-SiO2 base slag, which was saturated with silica and containing about 6 mass % MgO, and the Cu2S-Ni3S2-FeS matte with NNi /(NNi + NCu) molar ratios of 0, 0.25, 0.5, 0.75 and 1 was investigated at 1,573 K under the partial pressure of SO2 with 0.1 atm. The slag and the matte were equilibrated in a MgO crucible and the partial pressures of oxygen and sulfur were controlled by using an Ar-SO2-S2 gas mixture passing through a sulfur reservoir. It was clarified that the partial pressures of oxygen and sulfur in relation to the iron content in the matte were almost independent of the matte species. This was considered to be ascribed to the activity of FeS in the matte which was almost constant against the matte species when the composition of iron in the matte was specified. The content of copper in the slag at a specified composition of iron in the matte decreased with increasing the nickel molar ratio, NNi /(NNi + NCu), in the matte while that of nickel increased with increasing the nickel molar ratio. It was found that the distribution ratio of silver between the slag and matte phases was considerably small at less than 0.1 and had a tendency to increase with increasing the nickel molar ratio in the matte when the composition of iron in the matte was specified. On the other hand, the distribution ratio of cobalt presented considerably large values of about 1 in the range of low iron content in the matte.

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Dissolution and deposition of gold was studied for using the following equation (1) considered as a disproportionation of gold in a chloroaurate acid solution. 3 AuCl2- = 2 + AuCl4- + 2 Cl- …………… (1) An autoclave made of heat-resistant glass was used in the experiments. Gold wire was dissolved at a high temperature above 130°C by the reverse reaction of eq. (1) on the assumption of leaching gold scrap. After the dissolution experiment, the gold dissolved was recovered from the leaching solution by disproportionation in the cooling of the solution to normal temperature. At temperatures above 130°C, the gold wire easily dissolved in a 0.01 mol/l chloroaurate solution. It was considered that the dissolved weight showed an equilibrium concentration of AuCl2- in eq. (1). Though the concentration was small, it rose when the concentrations of Cl- or AuCl4- was heightened. The addition of Cl- had strong effect especially. Even with a small addition of 0.025 mol HCl-l, the dissolution weight of gold was elevated from 10-2 order g/l to several g/l. Namely, the effect for gold dissolution showed an increase of about 100 times. When the leaching solution of gold was cooled to a normal temperature, all AuCl2- ion formed by the reverse reaction of equation (1) was deposited as a metallic fine gold powder. There were submicron granular particles, fine particles with clear crystal faces and very thin flaked particles in the fine gold powder. It was clarified that these shapes were controllable by the cooling rate from the reverse reaction temperature to the disproportionation temperature.

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Translucent polycrystalline aluminas with different grain sizes were obtained by sintering the green compact, which was fabricated by using slip casting methods for high-purity α-alumina (99.99 %) powder of 0.24 μm in grain size, at 1,373 ∼ 2,073 K and by applying HIP method. Effect of average grain size on transmittance and mechanical strength of sintered bodies was investigated. For sintered bodies with average grain size of less than 2 μm, transmittance increased because of the effect by Rayleigh scattering. Non-translucent alumina with average grain size about 2 ∼ 7 μm is considered to follow Mie scattering. For average grain sizes larger than 7 μm, the transmittance was slightly increased based on the law of Fresnel. Mechanical strength of sintered body increased with decreasing the grain size, and depended on the inverse-square law of the grain size. Polycrystalline alumina with the average grain size of 0.8 μm showed the excellent properties of high transmittance and high mechanical strength, compared with that of lucalox.

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Silica particles which have relatively large micro pores were synthesized by the calcination of silica gel including well dispersed phosphorous and molybdenum compounds. The suspension solution which was not perfectly dissolved solution of silica and other inorganic compounds was dried in order to get rid of solvents and volatiles and successively calcinated. Afterwards, the compounds were dissolved with hot water. It newly showed that the average pore diameter was proportional to the square root of calcination time even when the pore diameter was in the region of sub-micron. The pore size and distribution were also able to be controlled by the relative ratio of the phosphorous and molybdenum compounds, especially it changed largely by the ration of (NH4 )6 Mo7 O24 4 H2O in the solution. They also depended on the melting points of multiple inorganic salts and their steric structure. The steric structure of the pores was like spinodal decomposition profiles which was expected that the pore size distribution was narrow. A new type porous glass which is different from the pore glass types made by boron-silicate and "shirasu" balloon could be prepared from a new multiple salts solution.

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