A simple technique to calibrate a downhole AE system to locate subsurface cracks is presented. Cross-hole detonation tests were employed for the calibration. In situ P-wave velocity in the formations is estimated from the P-wave arrival time. A simple formula associated with an appropriate filtering is proposed to equalize the difference of the frequency dependent coupling of tri-axial accelerometers set in a downhole AE sonde. Consideration ofthe ray path and the coupling compensation reduces the mapping error.
Data measured at Higashi Hachimantai Field supports the validity of this technique. The accuracy achieved in the mapping of the AE source lies within 10 degrees in all directions.

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Determination of in-situ stress change in rock mass during excavations is most important for security of underground constructions or mining excavations. However, monitoring of displacement or strains is mainly conducted for the purpose because there is not a simple and reliable method for measuring the change of in-situ stresses especially for the wide range of rock masses.
In this paper, a new method is proposed for measuring two-dimensional change of in-situ stresses, and the results of laboratory tests under both uniaxial and biaxial compression are described.
The new method uses a cylindrical pressure cell with eight strain gauges glued tothe inner wall of thecell, which is inserted in a borehole with non-contraction type of grouting material. A special merit of this method lies in the internal pressure test, which is carried out prior to the measurement of in-situ stress change, using the measuring instrument itself in order to know the mechanical interaction between the measuring system and the rock mass. Utilizing the information on the deformation modulus of the rock mass obtained in the internal pressure test, two-dimensional change of in-situ stresses in the rock mass is measured with least squares method on the circumferential strain distribution around the inner wall ofthe pressure cell as in equation (12).
Results of laboratory tests both in uniaxial compression and in biaxial compression are summarized in Tables 1 and 2, respectively. These results are almost satisfactory from the practical view point. However, non-linearity between compressive strains and applied stress at the lower levels of stress and poor increase of tensile strains at the larger levels of stress lower the precision of the predicted stresses. Although these points could be improved by increasing initial internal pressure as in the in-situ measurements, it is still necessary to conduct a systematic investigationon the mechanical properties of various grouting materials in order to choose the most suitable one.

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The most widely adopted method for determining airflow resistance in a mine is that based upon the measurement of airflow rate and pressure drop. However, as the measurement of pressure is time-consuming and prone to inaccuracy, in practice it is impossible to always maintain up-to-date data concerning airflow resistan ces for every change in the mine structure using this method.
On the other hand, as the measurement of airflow is easier than that of pressure and is regularly made for the purpose of safety, there is a large volume of data on airflow available in every mine. Therefore, if it is possible to calculate airflow resistance using only airflow data, this will contribute to an improvement in the accuracy of airflow resistance determination and also to a reduction in labor involved in ventilation measurement. This would lead to greater precision in ventilation network analysis.
From this point of view, the authors have examined the possibility of calculating airflow resistance using airflow data only. This has led to the following conclusions:
(1) Unique values for resistance cannot be calculated using only a single set of airflow data;
(2) Unique resistances can be calculated by using two or three sets of airflow data that have been measured under different conditions of ventilation.
Subsequently, two different methods are shown for calculating airway resistances. One uses the principle of the node potential method and the other uses the mesh method principle. If the airflow data are correct, both methods give correct values of resistance.

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In this report, the results of large diameter drilling tests in coal seams assisted with water jetsare described.
The results of these tests are summarized as follows.
(1) The length of the longest drill hole in the coal seam is 70m at Taiheiyo coal mine and thediameter of the most enlarged borehole is about 700mm at Akabira coal mine.
(2) Some measurements on the fundamental tests (gas flow, volume of cuttings, reduction of the stressin coal seam etc.) during drilling of the borehole indicated that a large diameter borehole made by using water jets wasas effective as drilling with the conventional methods.
(3) The penetration rate on the fundamental tests was 3.5 times as fast as with the conventionalmethod and it on the operational suitability tests was 1.5 times as fast as conventional method and the time to set up thedrilling unit was reduced to 50%

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The purpose of the present paper is to exhibit basic equations which are applied to slug flow in vertical pipes. The derivation of the equations was carried out as follows.
First the local and average void fractions in gas slug, liquid slug and overall system regions were defined clearly and the overall continuity equations of gas-phase and liquid-phase were represented. Secondly using eddy viscosity concept, the equation for the liquid-phase velocity profile in the liquid slug regions was obtained assuming that the void fraction profile in that region is known. Thirdly considering the flow of liquid film in the gas slug as one-dimensional flow, the differential equation of the liquid film holdup was derived. Furthermore, the coefficients of eddy viscosity due to wall generated turbulence and due to bubble induced turbulence, which are necessary to analysis of the liquid-phase velocity profile, were denoted as a function of radius respectively.
Analytical solutions and experimental results will be described in the next report.

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In this report, we describedo bservationso f behavioro n the long time leachinge xperimentsu sings ome enrichmentc ultures.
Our study was made by a conbinationo f the followingtw oexperiments;(1) a experimentw ithout containingn utrient except for energy source, which is the same as a method applied usually in a basic study of the pure culture, (2) a long time leachinge xperimentu nder pH 2 with a enrichmentc ulture.
The enrichment cultures were used for FeSO₄oxidation and S⁰leaching in the absence of nutritive salts. The relations between treatment time and product amount of Fe³⁺or SO₄^2-were linear.
The followingo bservationws ere obtaineda bout the behavioro f the enrichmentc ulturesi n these experiments.
1) It was supposed that the drop of apparent oxidation velocity of Fe²⁺at the high values of the ratio [Fe³⁺]/[Fe²⁺] resultedf rom the regulatorym echanismo f bacteria.
2) From the result of leachinge xperimentso f elementals ulfur, it was recognizedth at a enrichmentc ulture kept a constant activity for a long time.

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Agglomeration experiments were carried out using BaSO4 as model particles, sodium oleate (NaOl) as surface active reagent and kerosene as bridging liquid and agglomerate growth processes could be classified into three patterns as follows: Pattern 1) Agglomerates were formed immediately after the agglomeration experiment started and they gradually grew to certain sizes after which agglomerate growth slowed down (Figure 3). Pattern 2) Initially, micro-agglomerates were formed and after a certain aging time they grew rapidly to large agglomerates with intermediate size agglomerates also present (Figure 4 (a) and (b)). Pattern 3) Initially, micro-agglomerates were formed and after a certain aging time they grew to large agglomerates rapidly with almost no intermediate size agglomerates (Figure 5 (a) and (b)).
Simulations of these patterns were conducted using the population balance equations derived by the authors. The equations consist of a collision frequency function and a coalescence probability, formulated on the basis of Kolmogoroff's theory under isotropic turbulent flow conditions and the physical properties of agglomerates. Both the experimental and simulated results showed that in the case of pattern 1 agglomerate growth was restricted by a characteristic agglomerate diameter (C_D), at which the coalescence probability between two agglomerates of the same diameter was zero. There was good correlation between the weight mean diameter of agglomerates (D₅₀) and the C_D. In the case of pattern 2 and 3, the rapid agglomerate growth after the certain aging time is interpreted in terms of rapid increases in the CD. It was.also shown that breakage of agglomerates became significant for agglomerates larger than a limiting diameter. From these results, it was concluded that the agglomerate growth were controlled by C_Dand the three patterns were mainly caused by the differences in C_Dchanges due to compaction during the experiments.

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Thermodynamic and kinetic studies on the removal of Va elements (As, Sb) from molten copper using a CaO-Na₂SO₄flux were carried out.
The distribution coefficients of As and Sb between the flux and molton copper were obtained at 1473 K. Although the values of As distribution coefficients in a CaO-Na₂SO₄flux were smaller than those in a Na₂SO₃ flux, they were sufficiently high to consider its use as a flux for As in copper refining. The oxygen potential dependence of the As distribution coefficients suggested that the dissolved species of As in the flux was in the pentavalent state.
The removal rates of As and Sb from molten copper were measured at different temperatures and oxygen potentials.

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The extraction of rare metals from spent desulfurization catalyst was carried out by using aqueous hydrogen peroxide solution. The leaching test was done under the following conditions; the range of hydrogen peroxide concentration from 0.5 to 6%, pulp density range 20 to 200g/l, leaching temperature range 20 to 80°C and the range of leaching time from 5 to 60 minutes.
In the leaching with hydrogen peroxide, extraction of molybdenum, vanadium, nickel and cobalt increased with increasing hydrogen peroxide concentration, but, extraction of aluminium was not affected by hydrogen peroxide. For instance, the extraction rates of the components on leaching at pulp density of 20g/l for 60 minutes in the solution of 6% hydrogen peroxide were 98.5% for Mo, 85.3% for V, 95.3% for Ni, 96.7% for Co and 6.7% for Al respectively. Concequently, molybdenum, vanadium, nickel and cobalt were effectively extracted from the spent desulfurization catalyst with aqueous hydrogen peroxide solution.

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