This paper proposes a new self-organizing fuzzy control system for a nonlinear system accompanied by Gaussian noise and its application to pH control. This system permits to change a scaling factor for the membership function in accordance with the command signal, and also to estimate automatically a weighting factor for improving the fuzzy production rule. The pH control is carried out by simulation considered a two-stage stirred tank system.
The conclusions are as follows:
(1) The self-organizing fuzzy controller is sufficiently available in pH control without a strict control rule.
(2) The automatic estimation method of the weighting factor for improving the control matrix is better than the fixed weighting factor method.

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A new conditional expression has been proposed from the viewpoint of equilibrium thermodynamics for attaining a steady state with no existing flow of matter (static steady state) in a system which is not uniform in temperature and pressure. The conditional expression has been applied to a binary system under a uniform pressure, and it has been shown that the heat of transport can be related to the dependence of the standard entropy and the activity on temperature, and that it is possible to extend activity data of a solution into a wider temperature range by conducting experiments to attain the above-mentioned steady state in a system under a uniform pressure.

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X-ray powder diffraction method coupled with the prolonged grinding technique has been used for analyzing quartz and anatase in several kaolin samples. Kaolin minerals easily change from crystalline state to amorphous one by the prolonged dry grinding. This contrasts to the behavior of quartz and anatase. Because of this selective feature, Bragg reflections of quartz and anatase can readily be identified in the X-ray diffraction profiles of ground kaolin samples. The internal standard method was applied to the ground kaolin samples and quantitative analysis of constituent quartz and anatase was carried out. Gibbsite is known to become amorphous state by the prolonged dry grinding. Thus, present technique was also applied to the analysis of natural bauxite samples. The results clearly indicate that the present technique is promising for the analysis of quartz and anatase in kaolin and bauxite samples by reducing the difficulties unsolved in the conventional X-ray powder diffraction method.

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The effects of the thermal capacity of a heat source on the accuracy of thermal conductivity measurement were investigated numerically and analytically.
It was found that the accuracy is greatly affected by the thermal capacity ratio of the media to the heat source. It was also found that there exists a critical thermal capacity ratio at which the error becomes zero at a finite time. The relationship between measured and true thermal conductivities at sufficiently large times critically depends upon the capacity ratio, i.e. when the capacity ratio is smaller than the critical thermal capacity ratio, the measured thermal conductivity is always smaller than the true value and vice versa. A closed form formula defining the measurement errors for a given thermal capacity ratio and time was derived analytically.

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Aiming at the development of a less energy-consumptive process for producing hydrogen storag materials, an experimental study was carried out on the direct production of Ni-Rm (Rm: mixture of La, Ce, Pr and Nd) compounds from the mischmetal oxides by the reduction-diffusion (R-D) method. In the R-D process, a mischmetal oxide was reduced by metallic calcium at temperatures of 950, 1, 000 and 1, 050°C in the presence of nickel particles (size:-100, +200 mesh) and the reduced mischmetal elements diffused into the particles to directly form a Ni₅Rm compound.
An optical microscopic observation and an EPMA analysis of the reacted nickel particles revealed that three layers of Ni₄Rm, Ni₅Rm and Ni₅Ca were formed topochemically from outside to inside the particle, and that the Ni₅Ca layer was always sandwiched between the Ni₅Rm layer and the unreacted nickel core, suggesting that a reaction of the diffused mischmetal elements with Ni₅Ca to form Ni₅Rm, Ni₅Ca+ Rm=Ni₅Rm+ Ca, occurred. Volume fractions of the Ni₄Rm and Ni₅Rm layers, which were determined for the particles with an average diameter of 200 pm, using an image analyzer, were found to rapidly increase with the reaction time, and the unreacted nickel disappeared in 135, 55 and 45 minutes at 950, 1, 000 and 1, 050°C, respectively.
The experimental results were discussed based on the unreacted core model and a reactive diffusion mechanism, focusing on the role of Ni₅Ca which enhanced the rate of formation of Ni₅Rm.

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Anelastic strain recovery method is one of inexpensive and simpler methods for measuring in-situ stresses at great depth. However, the method has been based on the critical assumptions that the vertical boring axis is one of principal directions and that vertical stress is given by overburden pressure, which are not always true for actual rock masses.
In this study, by deriving a fundamental equation on the anelastic strain recovery of isotropic visco-elastic material in general three dimensional stress state, the method for measuring three-dimensional in-situ stresses has been proposed. In the method, by measuring six independent anelastic normal strains of a core, six anelastic strain deviations and anelastic volumetric strain are determined first. From the former, the orientations of principal in-situ stresses and ratios of principal in-situ stress deviations are determined without the knowledge of anelastic strain recovery compliances of the core, in-situ pore pressure and temperature change in the core. Then, by evaluating pore pressure and by correcting the effect of temperature change on the anelastic volumetric strain, absolute three dimensional in-situ stresses are determined by measuring the anelastic strain recovery compliances of the rock core in both shear and volumetric modes in the laboratory.

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In the present study, a series of adsorption tests by using coconut activated carbon were carried out on synthesized pregnant solutions containing thiourea complexes of gold and iron as a oxidizing agent. Then, elution tests were conducted by using ethanol and propyrene glycol as eluates.
From the results of adsorption tests, it was shown that adsorption of gold onto activated carbon was dependent on concentrations of thiourea, ferric ion and sulphuric acid, as well as activated carbon, and temperature. When the composition of a pregnant solution was 5g/l of thiourea, 0.2N of H₂SO₄ and 0.5g/l of Fe³⁺, Au was completely adsorbed onto activated carbon under the optimum condition, where activated carbon is 7.5g/l, temperature is 35°C and adsorption time is 75 minutes. Thus, it was found that coconut activated carbon was an excellent adsorbent for gold in the acidothiourea solution.
Elution tests were conducted by using different kinds of eluates, i. e., ethanol, propyrene glycol, sodium hydroxide and sodium sulphide. The results suggested that ethanol and propyrene glycol with NaOH or Na₂S were effective for eluting of gold from activated carbon loaded gold. Especially, Au was completely eluted by ethanol with NaOH under an optimum condition, i. e., 50vol% of ethanol, 0.4N of NaOH, 75°C and 2hr.

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It is of great importance to understand and know of the relationship between the mechanical properties of coal measure rocks and water content, in maintaining of mine roadways and utilizing mine waste rocks as packing and backfilling materials.
From this point of view, changes in mechanical properties of rocks, which are classified mainly into Palaeogene, exposed to alternate dry and wet conditions are investigated by laboratory tests. The measurements of pore volume and pore size distributions of these rocks are carried out with mercury penetration method.
The results are summarized as follows;
1) Slaking rocks exhibit remarkable deterioration in the mechanical properties even after a few times of repetition of dry and wet condition, whilst non-slaking rocks exhibit little.
2) Pore volume increases with times of repetition untill the onset of slaking.
3) These phenomena indicate that deterioration of mechanical properties is due to increased pore volume, namely microcracks.

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A series of fire experiments have been carried out in order to clarify the suppression effect of underground open fires by a method of ventilation control using parachute-type air block system in a full-scale test gallery with a cross section of 5.4 m². This air block system can be used at upstream side of fire and the parashute-type curtain made of heat resistant material seals off the fire area in short times.
The results obtained through the experiments are as follows;
(1) The airflow blocking effect of the parachute-type air block system is satisfactory when the air velocity is less than 3.0m/s. Approximately 85 percents of initial quantity of ventilation airflow can be blocked by using the air block system.
(2) The effect enough to suppress the underground fires involving timber sets and conveyor belts for use in coal mines can be obtained through fire experiments using the air block system in case of the relatively low air velocity.
(3) Temporary increase of fire gases such as carbon dioxide and carbon monoxide was observed during ventilation control, but the accumulated gases decreased rapidly as the suppression of fire. The diffusion of fire gases leeward side of fire and the reverse flow windward side can be prevented by using the air block system.

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The liberation properties of progeny mineral particles were discussed, considering the compression and impact comminution in the experimental study with an iron ore.
It was proved that fractional degree of liberation (FDL) remains nearly irrespective of the reduction ratio. It was also proved that FDL obtained by impact comminution is greater than by compression comminution. It can be explained by the preferencial breakage of iron mineral grains due to its selective fracture. It means that FDL can not be determined uniquely by the particle size.
Size distibution of the constituent mineral grains was also estimated by converting the areal data, measured by an image analysis on polished sections of raw materials, into volumetric distribution.

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Extraction equilibrium of Fe (III) with D2EHPA was investigated in the presence of alkyl phosphoric acids in order to elucidate the extracted species and extraction mechanism. Butyl phosphoric acid and 2-ethyloctyl phosphoric acid were used for the investigation.
The extracted amount of Fe (III) extremely increases by addition of alkyl phosphoric acids. In the presence of 2-ethyloctyl phosphoric acid, which has low aqueous solubility, the effect is impressive, while butyl phosphoric acid whose aqueous solubility is higher is not suitable for an industrial use and an investigation of extraction mechanism. The addition of alkyl phosphoric acids results in an enhancement of extraction rate of Fe (III).
Butyl phosphoric acid is more effective than 2-ethyloctyl phosphoric acid. 2-ethyloctyl phosphoric acid synergistically takes part in the formation of extracted species with D2EHPA which is the main extractant. In this research extraction of Fe (III) has been carried out from highly concentrated sulphate solutions and hence the extracted species and extraction equilibrium have been analyzed taking account of various Fe (III) species in the aqueous solution. The extracted species and extraction equilibrium have been inferred by a slope analysis method as follows, Fe³⁺+3/2 (H₂R₂) org+ (H₄A₂) org (FeR₃A₂H₄) org+3H⁺.

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Batch grinding experiments in a planetary ball mill were carried out using nine kinds of grinding media. Grinding media used were steel, alumina and porcelain balls with three diameters of 6, 8 and 10 mm. Specific surface area and size distribution of product were investigated to elucidate the effect of grinding media on initial grinding rate and limit in the planetary ball milling. In the initial stage of grinding, the specific surface area of product with steel balls was found to be greater than those with other balls. According to a grinding rate equation proposed in a previous paper, it was found that the initial grinding rate at the grinding time shorter than 1, 800 sec increased proportionally to 1.2 power of grinding energy regardless of the variety of balls. Final specific surface area of product is essentially considered not to vary with density of grinding media, but may be affected by the degree of the adhesion of product on the surface of grinding media.

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Ventilation network analysis to optimize ventilation network is becoming increasingly important, as underground structure extends and augments its complexity in coal mines. From this point of view, the new ventilation network analysis system has been developed to enable the user to analize mine ventilation network easily without receiving any special training. Though the system can be executed on micro-computers the maximum size of the network that can be analyzed by this method is in excess of 1000 nodes and 1500 branches. This system has already been brought into practical use in all major coal mines in Japan and is contributing much to solving various ventilation problems. This paper first describes the outline, merits, calculation method and program of the system. Then the process of the development and the result of promotion of practical use of the system are described.

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