The hydraulic fracturing technique as a method for determination of in-situ stresses has the advantage over other stress measuring methods in that it can be used at considerably greater depths from a point of access. This is of great significance in earthquake regions where stresses at hundreds or thousands of meters are of interest. Despite of the increasing use of hydraulic fracturing, however, there are uncertainties associated with the interpretation of the resulting data. In particular, confidence in the calculated maximum principal stress is less than in the minimum principal stress, although the former is often of great moment. Furthermore, the equation established to calculate the maximum principal stress is unclear. More recently, dry fracturing techniques have been developed and examined as the new potential method for determination of in-situ stress at great depth, through studies both in the laboratory and in the filed. In dry fracturing, the borehole wall is subjected to shear load as well as normal load, which are induced by internal pressurization of the probe.
The state of the art of rock stress measurement by hydraulic fracturing is reviewed and a comparative study is made of two kinds of dry fracturing techniques, which have been developed as the potential method for stress determination. The general review is followed by individual summaries of each method and the main characteristics of its validations and applications.

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In this study, the automatic system for boulder breakage by use of force sensors and image processing was investigated. In order to carry out the full automation of the boulder breakage, the following three subtasks have to be automated: 1)detection of the boulder, 2)control of the chisel to move to the boulder and 3)carrying out the boulder breakage. In this paper, two algorithms to automate the 3) task were proposed by use of force sensors and image processing. One is the algorithm to detect the chisel sliding while pressing the boulder by the chisel. This algorithm is based on the rate of strain change measured by strain gauges which were attached beside the chisel. The other one is the algorithm to detect the boulder breakage by use of the features from the signals of strain gauges and ones from image processing. It was confirmed through the experiments that these algorithms proposed here worked well.

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Triaxial compression tests at 50 MPa confining pressure and room temperature have been conducted under various constant axial strain rates ranging between 10^-7 s^-1 and 10^-3 s^-1 by using dried specimens of Inada granite. The experimental results showed that the ultimate strength, axial strain at failure, Poisson's ratio and anelastic energy which may be considered as the energy required to generate new cracks or to propagate pre-existing cracks in the compression process, increased with increasing strain rate. In addition, Young's modulus and fracture angle which is the angle contained by fracture plane and lateral section of specimen, decreased with increasing strain rate.
By comparing the strain rate dependence of the compressive strength and elastic constants of granites determined experimentally in the present study and the previous works, it can be decided that the strain rate dependence of the different rocks showed different features although the rocks were same granites in petrologic classification. First, the compressive strength increased linearly as the logarithm of the strain rate increase at intermediate strain rate range (considered as from 10^-8 s^-1 to 10^-1 s^-1, approximately) in any granite. At high confining pressure, the strain rate dependence of the strength is enhanced in fine-grained granites; in contrast, the dependence is enfeebled in medium-grained granites. Secondly, the strain rate dependence of Young's modulus had more complex behaviors than that of the strength. At the intermediate strain rate range, there are three types of granites which were (1) their Young's modulus did not depend on the strain rate, (2) their modulus increased with the increase of the strain rate, and (3) their modulus decreased with the increase.

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A bleeding examination and a flow characteristic examination of grout materials were performed to understand a difference of the flow characteristic by the difference in the material mixed grout materials. Moreover, the flow characteristic of grout materials in the voids and applicability to field of injection analysis were examined. The results are as follows
1) The influence of bleeding becomes the largest during a flow of W + C.
2) In W + C + P + B, the bleeding is controlled by making the connection with a clay particle and the electrolyte generated from cement.
3) W + C + P and W + C of 15 % or less of volume concentration can be assumed to be Newton fluid. However, W + C + P + B must be taken as Bingham fluid since yield stress changes with volume concentration a lot.
4) The plastic viscosity of the grout materials which flows the inside of the voids follows the theoretical equation which Mori and Ototake (1955) introduced regardless of the kind of grout materials.
5) The injection water and the injection grout materials will be flow in the laminar flow state if there is a proportional relation to the injection pressure, the discharge and Lugeon value.
6) It analyzed about the stage which has the relation shown by the above 5). Consequently, the injection analysis and the field data were well in agreement, and the applicability to the field of this analysis technique was confirmed.

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Currently, a tunnel boring machine (TBM) is widely used in tunneling. TBM is a full-face machine, therefore the face cannot be observed. This is disadvantageous especially in rapidly changing conditions, as is commonly the case for rock mass in Japan. In previous paper, equations (1) and (2) for estimating rock strength of face with TBM cutting force are proposed based on experimental findings.
σ_c = F_N / c₁p ……(1)
σ_c = T_R / c₂p^1.5 ……(2)
σ_c: rock strength p : cutting depth F_N : thrust force T_R : torque.
Constants c₁ and c₂ in equations (1) and (2) should be the function of the specifications of TBM(tunnel diameter, cutter diameter, cutter distance etc.). In this study, the relationship between constants (c₁ and c₂) and specifications of TBM was examined for ten tunnels.
It was found that constants c₁ was strongly influenced by a cutter diameter d.
c₁ = n(4.37d-1.43) ……(3)
n is number of cutter. With increase of a cutter diameter, not only contact area with rock, but also apparent strength of rock increased.
Constants c₂ was also influenced by tunnel diameter and cutter diameter.
c₂ = n(2.19-0.1D)(4.37d-1.43)……(4)
By equation (1) ∼ (4), thrust force and torque of TBM can be estimated if necessary information is available.

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As a motive power in heavy construction machineries including mining and various construction works, a multi-cylinders type of diesel engine is very often used because of its high cost performance. Steady maintaining of diesel engine's operation is substantial in view of economic demands and environmental concerns. To realize this, a practice of early diagnosis and early repair are essential.
In our previous study using a V-12 type of diesel engine installed on a bench, we demonstrated that a misfiring cylinder could be detected by statistical analysis method using rms value of the acceleration waveforms measured on a single point of the engine block.
In this paper, the same experimentation and analyses as in the previous study were conducted for two practical machineries that loaded the same type engine of the previous study. Even though the engine was loaded on a practical machinery, it was found that a misfiring cylinder could be detected by the same way as in the previous study. In addition to the analyzing method in the previous study, in this study, we employed a wavelet transform method with the Gabor function as a window, and analyzed the acceleration waveforms. The results of wavelet analysis revealed that a misfiring cylinder could be detected visually from time-frequency charts. With the aid of statistical analysis using rms value, a misfiring cylinder in a multi-cylinder diesel engine can be doubly checked by wavelet analysis.

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To develop an efficient method to recover Ce from radioactive wastes containing concentrated nitric acid, we have studied the possibility of the combination methods of selective electro-oxidation and anion exchange. The redox reaction behavior of Ce(IV) / Ce(III) in nitric acid solution has been investigated. Anion exchange behavior of Ce(IV) at various nitric acid concentrations and temperatures was studied. Moreover, separation of Ce(IV) from other rare earth elements was attempted by anion exchanger column.
The results of study by cyclic voltammetry indicate that the kinetics of the Ce(IV) / Ce(III) redox reaction on carbon electrode was significantly promoted by increasing HNO₃ concentration, while the formal redox potential remained at almost constant values between 1.34-1.38 V(vs.Ag / AgCl). Electrolytic oxidation of Ce(III) to Ce(IV) in 6 mol · dm^-3 HNO₃ solution was successfully performed with the conversion of 100 % and current efficiency near 60 % by using a novel flow type electrolysis cell containing a carbon-fiber column electrode as working electrode and Vycor Glass(porous silica glass) as separator.
Ce(IV) showed relatively strong adsorption on AR-01 anion exchanger as the form of nitrato-complexes such as Ce(NO₃)₅^- and Ce(NO₃)₆^2- and the distribution coefficient increased with increasing HNO₃ concentration. However, the adsorbed Ce(IV) was reduced to Ce(III) and eluted into the solution through redox reaction with the anion exchanger. Lowering temperature (< 288 K) can considerably suppress the redox reaction between Ce(IV) and the anion exchanger. It was found that the separation factor between Ce(IV) and other trivalent rare earths at 278-288 K was as high as 25-60. Separation experiments by AR-01 packed column demonstrated that Ce can be separated with high purity from a nitric acid solution containing La(III), Ce(III) and Nd(III) after electro-oxidation using the flow type electrolysis cell. The recovery of Ce was 82 % at 278 K, while La and Nd were not detected in the recovered Ce product solution.

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The coprecipitation behaviors of leaching solution and their sintering conditions have been examined to synthesize red phosphor (Y₂O₃:Eu³⁺) from phosphor sludge contained in waste fluorescent lamp. At first, the recovery of rare earth elements and the removal of impurity in the leaching solution were investigated by treatment processes such as hydroxide and oxalate precipitations. The drying process of coprecipitation reaction product was examined by freeze-dry and air-dry. The synthesis behavior of red phosphor (Y₂O₃:Eu³⁺) was also investigated by changing some factors such as temperature, time and flux. The experimental results obtained are summarized as follows:
(1) The homogeneous Y and Eu oxalate precipitations were produced by adding oxalic acid into leaching solution under the dispersion using ultrasonic stirring and the desiccation using freeze-dry.
(2) Y and Eu precipitations were sintered at 1,473 K for 144 ks under the addition of 1 % barium borate as a flux. Red phosphor (Y₂O₃:Eu³⁺) sintered had crystal size more than 0.2μm and average particle size of 5-6μm.
(3) Impurity elements in leaching solution were efficiently removed by hydroxide precipitation process, in which leaching solution was retained at less than pH 5.0 and by oxalate synthesis process, in which oxalic acid was added to use 3 times the molar quantity of Y and Eu hydroxides. In these treatments, recovery of Y and Eu were about 85 %, respectively.
(4) Synthesis process of red phosphor (Y₂O₃:Eu³⁺) from waste phosphor sludge contained in fluorescent lamp was established by using simulate leaching solution. On the basis of these treatment methods, rare earth powder of red phosphor was synthesized from waste phosphor sludge.
Luminescence properties of rare earth powder synthesized were in fairly agreement with these of commercial red phosphor. Rare earth powder synthesized in this work may be used substantially as a red phosphor.

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The objective of this study is to investigate the effect of various reaction conditions on zeolitization from coal fly ash. Hydrothermal syntheses of zeolite were carried out by using KOH as an alkali source. Various physical properties such as surface texture, identification of crystalline materials, cation exchange capacity and so on were evaluated for the obtained zeolites. From these results, the reaction mechanism of zeolite was considered in the hydrothermal synthesis by KOH as an alkali source.
Potassium-chabazite(K-CHA), which is one of the zeoltic materials, is obtained in 2.0 mol / dm³ KOH solution at 393 K of reaction temperature. The production of K-CHA is confirmed to begin at 5h of reaction time, and then the crystallization degree of K-CHA becomes constant at about 10 h. The value of cation exchange capacity(CEC) of the product is about 250 meq / 100 g at 50h of reaction time, at which crystallization degree reaches an saturation state. The reaction rate of K-CHA increases with an increase in KOH concentration, and the CEC in 4.0 mol / dm³ KOH solution at 50 h of reaction time becomes large up to 280 meq / 100 g. The layer of K-CHA crystal in the product is about 80 % as a volume standard.

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The premix dry mortar was used as tile substrate mortar, tiling mortar, joint mortar for tiles and so forth. The granulated blastfurnace slag or the annealed blastfurnace slag could not use as fine aggregate for the premix dry mortar, because of the poor workability.
In order to improve of the workability of mortar using the granulated blastfurnace slag as fine aggregate, a disintegration process was applied. The mortar tests using processed blastfurnace slag, non processed one and natural sand as fine aggregate were investigated. The workability of mortar using processed one was better than non processed one, and was similar to natural sand. Bending strength and compressive strength of mortar specimen were higher than non processed one and natural sand one. From these experiments, it was confirm that these processed blastfurnace slag could use as fine aggregate for the premix dry mortar.

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