Anelastic strain recovery (ASR) was measured on 8 cores obtained from the bottom of a 1, 000m depth borehole, drilled at Inagawa town in Hyogo prefecture.
The largest amount of ASR was observed on a 967m core of cataclasite, which was obtained from a shear zone. ASR up to 150 microstrain was observed on cores of sandy shale obtained from the depthes of 980-998m. The amount of ASR of individual core differd from those of others, although cores were obtained in only 3m apart from a same formation.
The direction of principal strain on a horizontal plane was estimated on 3 cores (967m, 992m, 995m). The direction of 967m and 992m cores, on which large amount of ASR was observed, coincides with that of the horizontal maxium stress obtained from a hydrofracturing test at the depth of 946m. The direction of 995m core, on which small amount of ASR was observed, differs from that of hydrofracturing test, but coincides with the old tectonic stress direction estimated from the syncline around the borehole.

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In order to predict blast vibration more precisely, we attempted to use the following equation described by circular frequency, that is used in the earthquake engineering field.
O(ω) =G(χ)·H(ω)·S(ω)
where, O(ω) is spectra of the wave motion of ground surface, G(ω) is the geometrical attenuation related energy spread during wave propagation, H(ω) is the transfer function and S(ω) is the source function.
We developed a computer program for a multi-reflection method based on Haskell (1960) to get H(ω) in above equation. For S(ω), we used the equation derived by Sharpe (1942). Finally, we had reasonable results for wave motion of a point of ground surface by calculating inverse FFT of O(ω) obtained by convolution of H(ω) and S(ω) about two layers model and four layers model.

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In order to reduce blast vibration, we usually use delayed blasting method.Recently, it became to be able to control delay time precisely within several, μ s. Based on such preciseness of initiation time, we studied nine setting methods of delay time for the purpose of reducing total ground vibration.As the results, we indicated setting method had influenced on peak particle velocity, predominant frequency and its amplitude remarkably and then discussed the results from point of view of blast vibration control.

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Through an extensive hydraulic fracturing experiment in granitic rock with low frequencies of joints, the initiation, reopening and closing behaviors have been carefully examined. zn this 3 rd report, the features which have not been dealt with in the previous two reports are discussed; the fracture direction and two deflection points in a shut-in curve.
A numerical analysis based on the weakest-link theory reveals that, with increase of the maximum compression stress SH, the mean and the variability of hydro-fracturing tensile strength T increases, while the variability of fracture direction decreases.
In this study, the vertical crack with a circular periphery tends to extend passing through the packers. When sufficient rate of flow is supplied for reopening the crack, the crack tip is fully open. After closing the water valve, the pressure is continuously decreasing, and the first deflection point Pctc is observed at the cracktip closing. With further pressure decrease, the crack surface is closing gradually from the outer to inner part. When the part of crack extended passing through the packers is closed, the second deflection point Ps₂ is observed. Considering the crack-closing process, Ps₂ should be larger than (3Sh-SH)/2 while Pctc is equal to the minimum compression stress Sh.
In this experiment, different values of Ps₂ have been observed at two depths while the values of Pctc (=Sh) are almost the same. According to the crack closing mechanism described above, smaller Ps₂ suggests larger SH. At a depth with smaller Ps₂, the variability of crack direction is small and SH is large. This result suggests that the variability of crack direction and Ps₂ possibly give useful information for stress estimation.

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It is considered that land deformation caused by open-cut mining influences wind shift around the quarry. The authors made a statistical study on the influence of topography on the wind speeds at 8 meteorological stations in Iwate Prefecture. It was recognized that the wind speeds at meteorological stations in the mountainous district were affected by the surrounding topography in sprig and fall. It was investigated the correlation between the mean wind speeds and the deviations of inclination. It was concluded that the topography within 1km-radius affected the wind speeds. It was obtained the next quantitative formulae between the mean wind speeds (V_s, V_f: m/s) and the deviations of inclination in the same directions (K_i).
V_s=-6.15K_i+3.03 (in sprig)
V_f=-5.16K_i+2.59 (in fall)
The deviations of inclination K_i are defined as follows.
K_i=tan α_i-16Σj=1tan α_j/16 (i=1, 2, ......, 16)
Where tan α_i=ΔH_i/L_i
Here, ΔH_i is the difference between the altitude of the base point and the highest point within 1km-radius.L_i is the distance from the base point to the highest point.
It became possible to predict the change of mean wind speed around the quarry by the use of these formulae. As a case study was conducted at the quarry that made a plan to be mined-out the whole mountain. As a result, it was predicted that wind system around the quarry would change widely with land deformation caused by open-cut mining.

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In our laboratory, development of a new detection system using different types of sensors was attempted for the detection of the spontaneous combustion of coal. The measurements of changing smell which was generated from the coal sample were carried out by using this detection system during heating the samples. Akabira coal, Ashibetsu coal, Sorachi coal, Taiheiyo coal and South Africa coal were used as the samples. The results of the measurements are summarized as follows;
1) Spontaneous combustion of coal can be detected earlier by this detection system than by conventional CO detection system.
2) The most sensitive sensors for spontaneous combustion of coal were 112AJ and 453AA.
3) There is no difference in the results for different kinds of coal.

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We have been studying a continuous measurement system for gas concentration by means of a photoacoustic effect, which is observed as photoacoustic energy when gas molecules are excited by laser beam energy.
In this paper, the photoacoustic properties of a newly designed photoacoustic cell are described. The structures of photoacoustic cell plays an impdrtant role on noise characteristics in the photoacoustic measurement system using a CO₂ laser. In order to obtain a better signal to noise ratio, configuration of cells and intensitiy of photoacoustic signals were examined experimentally based on data using a non-resonance single-tube type cell as a standard cell.
The results showed that a double-tube cell had a high photoacoustic isolation effect for external noises. Futhermore, the optimal condition for obtaining a high-intensity photoacoustic signal was ascertained by spectrum analysis of the resonant frequency of cells.
Thus, it was confirmed that a resonance double-tube type cell retained a better SN ratio, and was appropriate for the photoacoustic measurement system for gas concentration useing CO₂ laser.

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The present paper is concerned with a theoretical analysis of the steady characteristics of an air-lift pump system for conveying the marine mineral resources from the deep-sea bed to the sea surface. Here, the effect of pressure drop owing to the friction between the fluid and the inner wall of the pipe is taken into consideration. Some numerical experiments have been carried out using a set of five equations in the solid-liquid two-phase region and a set of eight equations in the solid-gas-liquid three-phase region for determining the nonequilibrium flow properties. In particular, the influence of the pipe diameter as well as the liquid-phase velocity on the solid-phase mass flux to be lifted has been examined from a numerical point of view. It has been quantitatively demonstrated how the mass flux of mineral ores decreases because the pressure drop due to the wall friction becomes more remarkable as the liquid-phase velocity is higher and the pipe diameter is selected to be smaller. Again, the critical condition whether or not solid particles can be lifted has been indicated with the liquid-phase velocity and the pipe diameter as parameters. Such important problems are described in detail.

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The extraction of rhodium (III) chloro species has been investigated by using a trioctylmethylammonium chloride (R₃R'NCl) in various diluents. The extraction isotherm decreases
The extraction isotherm decreases with increasing the acid concentration. The stoichiometric composition of the complex formed in the organic phase deduced to be (R₃R'N) RhCl₄(H₂O)₂. Therefore, the following mechanism is proposed for the extraction of rhodium (III) chloro species.
R₃R'NCl (org) +RhCl₄(H₂O)₂^-(aq)⇔(R₃R'N) RhCl₄(H₂O)₂ (org)+Cl^-(aq).
These results are also confirmed by visible and infrared spectral measurements.
In the examination of diluents effects, nitrobenzene and benzene most promoted the extraction of Rh (III) at 0.1 and 7 mol dm^-3 hydrochloric acids, respectively.
The distribution ratio increases with increasing temperature.

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