In order to elucidate the reduction rate of zinc oxide with metallic iron and CO, kinetic experiments were carried out in the temperature range between 1, 171 and 1, 473 K. Experimental data for each reduction were analyzed by the isothermal unreacted core model and the isothermal shrinking model, respectively.
For the reduction of zinc oxide with metallic iron the specific permeability kp of zinc vapor is expressed by the following equation:
log (kp/m²)=-19.398+0.8767×104 T^-1/K^-1
Under the experimental conditions the overall rate is controlled by the permeation of zinc vapor through the pores of the product layer formed.
Under the experimental conditions the overall rate is controlled by the permeation of zinc vapor through the pores of the product layer formed.
For the reduction of zinc oxide with CO the reaction rate constant/cc is obtained by the following equation and the activation energy is 162kJ-mol^-1 in the temperature range 1, 273-1, 473 K.
kc/10^-2m·s^-1=exp {9.766-161.7×10³/(RT)}(1, 273-1, 473K)
The chemical surface reaction controlls the overall reaction rate under the present experimental conditions.

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An experimental program of disc cutting was carried out using a circular rock cutting testing rig for seven selected rocks occurring in Japan, Korea and China. The program aimed at establishing the optimal condition of disc cutting, finding the relation between the peak tool force and the mean tool force, and estimating the effect of radius of cutting track on the lateral component of the tool force. The main results obtained from the present study are as follows:
(1) The optimal ratio of tool space to disc penetration that enables us to minimize the specific energy for excavating rock depends on the fracture toughness and the uniaxial compressive strength of rock.
(2) The specific energy at the optimal cutting condition correlates linearly with the uniaxial compressive strength of rock.
(3) All the components of tool force vary around their mean values, resulting in stochastic process. The lateral force fluctuates more heavily than the rolling force, although their mean values each are comparable to the other.
(4) The peak tool force is in proportion to the mean tool force: the magnification of peak to mean is 1.33, 1.60, and 1.63 for the thrust, the rolling force, and the lateral force respectively, regardless of different types of rocks.
(5) The magnitude of lateral force does not depend on the radius of cutting track when rock between neighboring tracks are cut off completely. Lateral force is always directed toward the adjacent cutting track.

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Continuous measurement on gas drainage was carried out at 22 drilling sites of No.1 and No.3 slope area in Minami-Oyubari coal mine. In this coal mine, methane drainage method from seam-road using each drilling site where 40-60 boreholes were drilled as gas drainage area has been developed.
The results obtained are as follows.
1) Patterns of gas drainage at each drilling site can be divided into three types according to geological conditions.
2) With the exception of one example, it is recognized that cumulative gas drainage volume was in proportion to the peak value of gas drainage rate.
3) Cumulative gas drainage volume, cumulative gas drainage volume per coal reserve within the boring area of fan-shape and cumulative gas drainage volume per boring meter related to No.1 slope area were different from these related to No.3 slope area. These values of No.1 slope area were respectively 3.1, 3.7 and 2.4 times compared with No.3 slope area.
4) With gas drainage at each drilling site of No.3 dip area, the peak value of gas drainage rate at drilling sites with faults was about 2.0 than this value at drilling sites without faults.
5) Relationships between boring length per 1m2 of gas drainage and cumulative gas drainage per coal reserve divided according to geological conditions are recognized.

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The composite film which consists of Cr nitride and Fe-Cr solid solution has been formed on pre-nitrided steels in molten salts, where these steels were immersed and then Cr diffused and cemented into steels. The standard composition of the molten salts were eutectic salts of KC1-BaCl₂-NaF with CrF₃ and ferro-chromium as metal sources. Only when all of NaF, CrF3 and ferro-chromium existed in molten salts at the same time, the film is formed, so the formation reaction of the film was confirmed to be a disproportionation reaction.
The amount of surface films increased with an increasing of Cr treatment time, and then reached to almost constant. The surface layer was found to be a composite film with Fe-Cr solid solution and CrN through the X-ray analysis and EPMA. In the case of high Cr treatment temperature, Cr₂N and Cr₇C₃ were detected besides CrN and Fe-Cr solid solution. The surface hardness value of Cr treated specimen increased with high Cr treatment temperature. High surface hardness is due to the compounds such as Cr₂N and Cr₇C₃ in surface films. The corrosion resistance was also improved by Cr treatment.

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Thermal oxidation of TiN, CrN and TiAIN films were studied in air at temperatures from 923K to 1, 173K. These nitride films were deposited onto stainless steel substrates using an arc ion-plating appratus. Oxidation rates were calculated by the weight changes with time. Formed oxide layers were analyzed by XRD, SEM, and SAM. The oxidation rates were proportional to square-root of reaction time. This means the oxidation are controlled by diffusion. The difference of oxidation rates among films materials were compared from the Arrhenius plots of the rate constant. The calculated activation energy of 136 kJ/mol for oxidation of TiN was less than that of 180 kJ/mol for oxygen diffusion in TiO₂. This difference suggests that the oxidation of TiN is enhanced by grain boundary diffusion of oxygen in formed oxide film. The activation energy for CrN was 251 kJ/mol, which was almost the same value as that of diffusion of Cr ion in Cr₂O₃. The oxidation reaction of Ti0 9Al0.1N is much faster than that of Ti0.6A10.4N. The activation energies were 215 kJ/mol for Ti0.9Al0 1N and 471 kJ/mol for Ti0.6Al0 4N, respectively. The activation energy for Ti0 6A10 4N was almost the same as that of diffusion of Alion in Al₂0₃.

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An experimental study was carried out on the reactive diffusion in the Ni-La binary alloys for providing a fundamental knowledge of the reduction-diffusion (R-D) method to directly produce powders of nickel-rare earth compounds RNis for use of hydrogen storage materials.
Phase relationships were investigated at temperatures above 1, 100K and in the concentration range of nickel above 60 mol%, using reactive diffusion and metallographic methods. New compounds of LaNi₄ and La₂Nis₅ were found in the process of reactive diffusion. Peritectic reactions relating to these compounds were L+LaNis→LaNi₄ at 1, 408K, L+LaNi4→La₂Ni₇ at 1, 373K and L+LaNi3→La2Ni5 at 1, 153K. Solubility limit of a LaNis solid solution was determined by an EPMA analysis, and the maximum solubility was 82.4-85.6mol% Niat 1, 543K.
Interdiffusion coefficient D of the LaNi₅ compound was determined in the temperature range from 1, 423 to 1, 503K, using a diffusion couple, and was given as D/m2·ES-1=1.02×10-1·Eexp (-294 kJ·Emol^-1/RT) with activation energy of 294 kJ·Emol^-1 (R: gas constant).
Diffusion experiments using a diffusion couple of Ni/CaNi₅/Ni-La melt were carried out to investigate a role of the CaNis thin coating layer on the surface of the metallic nickel, which drastically enhanced the reactive diffusion to form the LaNi₅ compound.

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Oxygen pressure measurements were carried out by immersing a disposable oxygen probe into converter slag, white metal or blister copper which had been poured into a ladle from a commercial PS copper converter after the completion of the slag or copper making stage. Measured oxygen pressures were all normalized at a constant temperature depending on the molten phase so as to investigate the reproducibility of the measurements, the oxidation degree of each phase and so on. The following results were obtained in this study.
(1) A stable electromotive force of the oxygen probe was obtained in about 15 s after the immersion of the probe by shaking it in each molten phase.
(2) The reproducibility of the measurements was good in each of the phases. However, the reproducibility for white metal was slightly inferior to those for converter slag and blister copper, probably because white metal is more easily oxidized by air than the others.
(3) Each of the molten phases produced in the converter was completely poured into several ladles, and then the oxygen probe was applied to each of the ladles. Since there was no significant difference in oxygen pressure among the ladles, the oxidation degree of each phase can be deemed uniform in each phase.
(4) However the oxygen pressure of converter slag was a little lower than that of white metal, and the converter slag was not in real equilibrium with the white metal even after the completion of the slag making stage.
(5) Part of the blister copper near the tuyeres was excessively oxidized at the final blowing in the copper making stage to the extent that Cu₂O (s) was formed.

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Strongly c-axis oriented Pb (Zr_xTi_1-x) O₃ thin films were successfully grown on (100) Pt/(100) MgO substrate using the metalorganic chemical vapor deposition (MOCVD) method. The electrical properties of PZT thin films with thickness of 2μm are almost the same values of PZT single crystal. But they sharply change below film thickness of 0.5μm: dielectric constant and remanent polarization decrease, and coercive field increases. These phenomena are explained by the model that low dielectric constant layer exist in series with normal PZT layer. The origins of this layer is considered to be the intrinsic stress produced by the coalescence of crystal grains.

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Discharge behaviour has been determined at 25 for the characterization of the manganese dioxides produced by ozone oxidation in acidified manganese (II) sulfate solutions at a constant ozone partial pressure, 2×10^-2 atm. A descent of the manganese dioxide electrode potential with discharge time was measured in 9.0mol/l KOH solution at a constant applied current of 2.0mA/0.10g MnO₂.
The manganese dioxides, identified as gamma type according to X-ray diffraction data, showed discharge characteristics analogous to the electrolytic manganese dioxide for battery use. The observed discharge behaviour of the manganese dioxides was found to be significantly influenced by ozonation conditions, reaction temperature, from 25 up to 80°C, and acid concentration of the solution up to 5.0 mol/l.
The manganese dioxides formed at temperatures above 60°C in solutions of acid concentration of 0.5 to 1.5 mol/l possess the discharge capacity larger than some typical electrolytic manganese dioxide samples. Similar discharge curves were observed also for the manganese dioxide precipitated from the solutions simulating zinc sulfate electrolyte solution.

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