Self-Organizing Neural Network (SONN) was constructed for the purpose of mineral identification. This system consists of two different kinds of networks, Kohonen's Self-Organizing Map and three layer feedforward neural network based on the back-propagation learning algorithm. The former step, Self-Organizing Map, could divide minerals into some categories by the similarities on the selected characteristics of minerals. This rough division of whole input patterns on feature maps was closely analogous to the first step of classification by human brains. The later step, each category had the three layer feedforward neural network independently, and then the minerals belonging to the same category could be identified.
In this study, 82 minerals were identified by 5 characteristics of cleavage, metallic luster, Mohs hardness, streak, and color. Some minerals have plural input patterns on the 5 characteristics mentioned above. Therefore, total number of input patterns was 119 for 82 minerals.
After constructing the feature maps and the back-propagation learning, this system could suggest the suitable mineral name for unlearning input patterns. The advantage of the proposed method is that scaling up of the system is possible with relatively small increase in learning times. Further, it should be stressed that this technique can be used in other problems where recognition and identification are necessary.

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The mechanical behaviors in coal and rock masses during longwall extraction were monitored around six longwall coal panels of Taiheiyo Coal Mine by the use of hydraulic capsules, load cells etc.
The following conclusions can be made from our studies.
1) The abutment pressure zone, which forms in solid coal ribsides with face approach, moves deeper as a result of the enlargement of the stress relief zone.
2) Monitoring the pressure changes of hydraulic capsules, it was clarified that the coal seam near the fault was severely loosened.
3) Floor heave dominates as a deformation mode of roadways, and the deformation behavior of steel arches can be divided into three types according to the load-displacement curves.
4) The vertical stress changes in goaf measured by load cells gradually increase with face advance. Also they are dependent on the distance from the ribside and the geometry of the old workings in upper coal seams.

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In the past, many methods of measuring gas concentration were developed. However, limitations lixe; selectivity in the kind of gases the system can measure, range of gas quantity and pre-treatment requirements prevented the wider applications of these techniques.
The objective of this research is to develop a method for measuring gas concentrations that is free from the above mentioned limitations. In this regard, the principle and the technique of measuring the sound generated by the spectral diffraction of a laser beam was investigated.
This technique is fundamentally different from any other usual spectroscopic analysis: this is an indirect method which measures the acoustic pressure emitted from gas when the photo energy is supplied to it.
First, miniaturized laser equipment was fabricated based on diagrams and gas flow type. Then the primary parameters in this system in terms of the sensitivity of this system are the following; the laser's power output, the chopping frequency and the acoustic cell shape. The influence of these factors on the sound generated by the beam were investigated.
As an condition of this system, a CO₂ laser with output power of under 5.0W, a radial cell and a chopping frequency of 20Hz were chosen. As a result of the experiments under this condition, we confirmed that acoustic signal is proportional to gas concentration of single and mixture gas.
For high sensitivity analysis of measuring acoustic signal, the noise characterics in measuring system, which was occured by discharge tube of laser, microphone, acoustic cell and so on, were measured and were eliminated. The new discharge tube of laser without noise was fabricated. And we maked out for the about thirty kinds of diameter, axies lenngth and mass of acoustic cell. The chopping frequency was chosen outside for frequency of noise. It was found that the gas concentrations of Ethylene was measurable in the ranges of concentration 1ppm-10%.

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A heading face is usually ventilated by forcing auxiliary ventilation system with duct and local fan, because heat, gases and dust particles by blasting or machines are liberated in the heading place rather than in other working places. A number of studies about ventilation at a heading face have been reported, but most of the results are based on assumptions due to difficulties in measurement of experiments and in theoretical analysis.
However, as environmental problems arise from accelerated mechanization of heading operations, detailed investigations of air flow at a heading face is increasingly important for effective ventilation control.
From this point of view, a theoretical study on the profile of ventilation air flow at a heading place has been performed. The 3D unsteady turbulance flow code which are solved by SIMPLER algorithm based on the finite different method was used in this study. It is shown in this paper that the results of simulation coincide with the actual phenomena and can be available to estimate of air flow of ventilation at the working places.

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In a previous study, authors discussed probability distribution of strength and failure time in compression. In this study, uniaxial and indirect tension tests and creep test were carried out under air-dried and water-saturated conditions. Sample rocks are Sanjome andesite, Tage and Oya tuffs. The experimental results indicate that both uniaxial and indirect tensile strengths of three sample rocks follow the Weibull distribution whether in air-dried or water-saturated condition.
On the assumption that the failure process under constant load (creep test) is not differ from that under constant stress rate, the relation between fluctuation of strength and that of failure time was proposed in the previous work. Through detailed examination, it was found that the experimental results in tension as well as in compression conform fairly well to theoretical estimation.
The most important results obtained by the previous and this studies are that probability distributions of strength and failure time in tension does not differ so much from those in compression.

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In Japanese open pit limestone quarries, the drill and blast method using the bench cut system is employed. Since the success of drilling machine is more sensitive, its application should be made after proper evaluation of geological conditions and rock characteristics in order to predict the machine performance and bit consumption and so on. Geological conditions have a significant effect on the performance of drilling machine. Unconfined compressive strength or uncofined tensile strength of intact rock which is used as an index for criterion or prediction is not good because the fragmentation mechanism is not considered well. It is more important to consider the consumed energy value in fragmentation such as the rock impact hardness number (RIHN) than the strength failure value such as the unconfined compresive strength or the unconfined tensile strength for criterion or prediction of machine performance.
From these points of view, this paper discusses the predicting method of the drilling rate and the selecting method of the drilling machine by using the rock impact hardness number, RIHN.

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In order to solve a flow problem using the conservation equations, it is necessary to give a set of constitutive equations. It is the purpose of this work to investigate the constitutive equations for onedimensional gas-liquid-solid three-phase flow in vertical pipes with a mixture model. In this paper, we discuss average velocities and average volumetric fractions of each phase experimentally by applying a drift flux model.
For the gas phase, using the drift flux model based on the mixture center-of-volumetric velocity (mixture volumetric flux), the distribution parameter was examined by adapting the drift velocities which several investigators proposed for gas-liquid two-phase flow systems. Furthermore the analysis took into account the effect of the radial distributions of local phase velocities and local volumetric fractions on the distribution parameter for bubbly flow regime. For the solid phase, the similar parameter to the distribution parameter was correlated by using a flow model based on the mixture center-ofmass velocities. Then concerning the average volumetric fractions of gas and solid phases, calculated results by using the obtained correlations agree with the experimental data.

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Fundamental matters on the flotation of sulfide mineral, such as galena, were clarified using 2-mercaptobenzothiazole (MBT) for the collection and depression phenomena. The galena recovery shows a maximum in the pH region from 6.0 to 9.0. In the tests, the flotation recovery increases with increasing the concentration of collector. The adsorption density varies linearly with the equilibrium MBT concentration and it exhibits a maximum near pH 7.0 corresponding to pK^a of MBT. The flotation recovery of partly oxidized galena exhibit a marked increase in the alkaline region as compared with clean galena ore. Further, the effects of adding two kinds of collectors on the collection of mineral in flotation were cleared up in the case of MBT-potassium ethyl xanthate (KEX) combination. The competitive adsorption of collectors on sulfide mineral was recognized in the case of MBT-KEX combination.

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In order to establish the anodic behaviour of the Pb-Ag alloy for zinc electrowinning, anode potential and AC impedance characteristics of Pb-Ag or Pb-Sn alloy anodes in a sulfuric acid solution were investigated using galvanostatic techniques. The anode potential decreases with increasing Ag content for the Pb-Ag alloys. The potential for the Pb-Sn alloys is constant at about 1.88 V vs. Ag/AgCl, independent of Sn content. There is a good correlation between the anode potential and the charge transfer resistance obtained by AC impedance measurement, and it shows that nearly a quarter of the decrease in the anode potential is attribute to the decreasing in the resistance. X-ray photoelectron spectroscopy reveals that Pb0 is produced between the underlying alloy and the surface oxide, Pb0₂. This result supports the presumption that doping of alloying element, Ag or Sn, into the oxide layer produced by electrolysis affects the charge transfer resistance.

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