Solid state electrotransport (SSE) is one of the most promising methods for the removal of interstitial gaseous impurities from metallic materials. In this review, from the viewpoint of the purification, the trends of the SSE processing are reviewed after the 1960's since when the SSE processing has been mainly used as one of the purification techniques. Firsts of all, a history of the SSE studies and the characteristics and the general concept in the SSE treatment are described. Various measuring methods of the SSE properties, such as the effective valence, non-dimensional number δ, are explicated and the features in the individual methods are pointed out. By using many results in the literature, the attainable purification degree by the SSE treatment is discussed not only under the steady state but also under the unsteady state conditions. At last, by exemplifying the discrepancies between the theoretical results and the experimental results, the causes of the discrepancies are explained.

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A pH-measuring system was daveloped for the study of rock/hot water reaction. This system consists of a main reaction autoclave and a pH-measuring cell, and the main autoclave is connected with the pH measuring cell by three sampling pipes. The pH of reaction solution can be measured directly at the same temperature and pressure as the main autoclave. A platinum-hydrogen test electrode and a silver-silver chloride external pressure-balanced reference electrode were used in the pH-measuring cell. The pHmeasuring cell showed a Nernstian pH response in the all temperature and pressure ranges (100-250°C and 50-200kgf/cm²) studied here. The temperature dependence of pH for calcite-water system was determined under the saturated solubility condition in the temperature range of 100-250°C using the pH measuring system.

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In the previous studies, authors carried out the computer simulation by FEM program and discussed the failure process and the size effect of rock specimen model subjected to compressive stress.
In this study, behaviour of rock specimen under uniaxial tensile stress is examined by a similar computer simulation and some experimental work. For the computer simulation, FEM program implemented with a non-linear visco-elastic constitutive equation is used. In the experimental work, two kinds of rocks are tested under uniaxial tension to obtain the complete stress-strain curves. Surface of a rock specimen is carefully examined with the aid of CCD camera.
The calculated results indicate that failure process of rock specimen is considerably complex, that is, cracks initiate and propagate at many separated locations in the specimen and a macro crack which leads to final failure is not a straight line but having many sharp turns. This calculated result conforms to the experimental result.
The computer simulation also indicates that strength of specimen decreases with increase of the number of elements in FEM mesh. However, number of elements exceed 90, then strength dose not change apparently. It is also found that the loading rate dependency of strength decreases with number of elements. These results quantitatively coincide with the results obtained in the previous study for compression stress.

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A general theory of isotropic elastic spherical shell has been presented to evaluate the initial stress field. Extending the original theory of isotropic elastic spherical shell presented by McCutchen, the thermal stress has been analyzed and the influence of the temperature gradient near the surface and the thermal stress has been discussed. The theoretical solution shows that the fundamental relationships realized near the surface are as follows. Namely, the vertical normal stress coincides with the overburden pressure and the horizontal strain is determined by the ratio of the surface subsidence to the radius of the earth. Then, in the general model, the average horizontal stress at a certain depth is given by a function of the elastic constants with stress dependency.
To make clear the profile of the average horizontal stress and to investigate the applicability of the general theory, the ratio of the average horizontal stress to the vertical stress has been analyzed and compared to the measurements by means of the stress relieving method in the world. Showing the close agreement between the measurement and the calculation, it has been concluded that the vertical distribution of the Young's modulus, which is deeply depending on the mean normal stress, plays an important role in determining the magnitude of the average horizontal stress. Finally, the expansion of the theory to the anisotropic field has been pointed out to be a future work.

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Significant errors may occur in the estimates of the initial rock stress from results of measurement which were carried out in anisotropic rocks, when the ovecoring method based on the isotropic elasticity was adopted for the measurement of the initial rock stress. Analytical solutions and computer programs have been prepared to apply the USBM borehole deformation gauge and CSIRO HI stress cell to anisotropic rocks. However, for the conical-ended borehole technique, which is effective for the initial rock stress measurement in isotropic rocks, applicability of it to orthotropic and transversely isotropic rocks has not been discussed because that there is no analytical solution for a special bottom shape of borehole.
In this paper, theoretical approach to assess the applicability of the conical-ended borehole technique to transversely isotropic rocks is presented. Firstly, the theory of analyzing the strains on the conical bottom surface, applying the initial rock stress, is shown. Then the displacement coefficients and the strain coefficients, which is necessary for the theory, are calculated from results analyzed by 3D boundary element method. Secondly, the strains on the measurement circle of the conical borehole bottom surface are computed, applying initial stress components individually. Subsequently, evaluating errors between the assumed initial rock stress and the analyzed initial rock stress from these strains by the conical-ended borehole technique neglecting the rock anisotropy, it is made clear that the conical-ended borehole technique is applicable to transversely isotropic rocks in the case that the borehole for measurement is directed normal to the plane of isotropy of a transversely isotropic rock and the mean value of the Young's modulus of it is used in estimates of the initial rock stress.

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This paper is mainly concerned with the velocity dependence of the erosion of metallic materials by non-traversing water jets impinging normally in the air, using a cylindrical nozzle. The experimental conditions are a discharge pressure of 28 MPa to 104MPa and a nozzle inner diameter of 0.6mm. Materials tested are aluminium and brass, and the time-averaged incident velocity of water jets has been determined by means of the impact force measurement.
The centre depth of the crater produced by the water jet impact of a certain time has been firstly investigated using a precision micrometer system, and a remarkable axial region results in a constant centre depth has been successfully found out over a wide range behind the axial location where the water jet begins to break up. In this axial region, the erosion speed of the surface erosion period until the centre depth reaches the nozzle inner diameter has been secondarily investigated as well as the erosion profile in the subsequent drilling process.
The centre depth in the surface erosion period is clarified to increase in direct proportion to the time of impinging, and the erosion speed is proportional to the 6th power of the incident velocity. The present relationship has been discussed to be a fundamental law for erosion caused by the microcrack propagation with the repeated impact and subsequent surface fragmentation, basing on the fracture mechanics. Additionally with respect to the drilling process, it has been clarified that the erosion speed on the bottom surface decreases with increasing the depth of hole, reflecting the velocity attenuation within a drilled hole.

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An oscillating jet nozzle has been developed to improve the efficiency of water jet cutting. In this nozzle, several piezo-electric transducers attached to a vibration plate give high-frequency oscillation to inner high-pressure water. These transducers were driven by the electric circuit composed of a function generator, an amplifier and a matching box.
Firstly, to evaluate the performances of this nozzle, the characteristics of electro-mechanical transformation and mechanical-acoustic transformation were analyzed. Equations which could estimate the vibration velocity, sound pressure and cutting speed were derived by simplified model of this nozzle.
Secondly, photographic studies of oscillating jets and cutting experiments were done. These results were compared with analytic results qualitatively. Main results were as follows.
1) In case that oscillation frequency was constant, wave length became longer according to the increase of the water jet velocity.
2) Increase of the water jet velocity reduced the wave amplitude of oscillating jet under the constant electrical power.
3) Mass loss increased with growing the electrical power which supplied to piezo-electic transducers, but there was a saturation point in electrical power-mass loss curve.
4) In this study, by using oscillating jet the increment of mass loss was recognized from stand-off distance of 30 to 180.

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It is a well-known fact that a little fine dust in a glass tube containing a vibrating column of air disposes itself in recurring patterns. These striped dust patterns are called as “Kundt's Dust Figures” in honor of his discovery. The purpose of the present study is to apply the Kundt's method to solid-liquid mixtures for making concentrated solid clusters in a tube. Ultrasonic wave was used as a source of vibration. Two types of polystyrene particles and fine titanium oxide particles (powder) were used for the experiments.
As the results of the experiments, the neutraly buoyant polystyrene particles formed regular stripes of concentrated clusters in salt water. With increasing the particle concentration, the stripes of the clusters disappeared and a massive cluster was gradually formed at the upper part of the tube. The particles slightly heavier than liquid also made a massive cluster in the middle of the tube. The fine titanium oxide particles did not show clear cluster patterns, however, after draining the mixture, the particles remaining on the inside wall of the tube indicated the formation of weak stripes.

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The effect of surfactant addition on bacterial leaching of chalcopyrite by Thiobacillus ferrooxidans was investigated with polyoxyethylene sorbitan monolaurate (Tween20) as a surfactant. Bacterial leaching experiments were carried out without nutrient mineral salts such as ammonium sulfate to avoid the complication of leaching behavior with cell growth. Without the surfactant, most cells adhered to the mineral surface and soluble iron was dominantly present in ferrous form. The surfactant depressed the cell adhesion to the mineral surface and the number of cells in the liquid phase increased with increasing addition. When adding 20 to 50g/m³ of the surfactant, the cells in the liquid phase rapidly oxidized ferrous ions to form ferric ions and chalcopyrite was chemically oxidized by the ferric ions, as a result the amount of extracted copper increased markedly. However, the excessive addition depressed the bacterial ferrous oxidation and the chemical leaching of chalcopyrite with ferric ions, and decreased copper extraction.

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Lithium antimonate (Sample L) and lithium antimonate containing 5 mol % of potassium antimonate (Sample K) were synthesized by a pyrometallurgical method. Lithium ion in lithium antimonate was exchanged with proton in a nitric acid solution by using the column method and the batch method. The effects of temperature and nitric acid concentration on the ion exchange rate were investigated, and following results were obtained.
(1) The ion exchange of sample K proceeded more rapid than that of sample L.
(2) The ion exchange rate was fit to the following equation.
1-2/3a-(1-a)^2/3=kt
where a, k, and t are fraction reacted, apparent rate constant, and time, respectively.
(3) Arrhenius plots of the apparent rate constant showed that the apparent activation energy for the sample K and sample L were about 100kJ/mol and 130 kJ/mol, respectively.
(4) The nitric acid did not affect the apparent rate constant at high concentration region.
(5) The rate-controlling step for the ion exchange was diffusion of lithium ion in the sample at high nitric acid concentration region.
(6) The enhancement of the ion exchange rate can be attributed to the formation of potassium solid solution and the decrease in particle size by the coexistence of potassium antimonate.

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Properties of rapidly solidified TiN powder which was produced by reactive gas atomization process using laser were investigated.
It is necessary that laser power and gas pressure is kept high for stable atomization to obtain TiN powder. Nitrogen concentration in TiN powder increases in proportion as laser power and gas pressure increases.
Nitrogen concentration of TiN powder estimated from lattice parameter are in the range of 31.5-34.4 at%, resulting in the composition of TiN _0.46-0.53.
It was found from X-ray diffraction pattern that the N deficient TiN_1-x which consisted of TiN and TiN 0.3 changed ε-Ti₂N phase by heating over 873 K. At the same temperature, exothermic reaction is observed by DSC thermal analysis under an inert atmosphere.
Knoop hardness in the TiN particles varies from min HK 500 to max HK 2500.

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