This paper describes a new and simple method for determination of effective porosity with transient flow of gases through a porous media.
The unsteady flow of gases through porous media is influenced by effective porosity. We have expanded numerical model and method used by Aronofsky and Jenkins by including thetime for inlet pressure to rise in order to construct the methodof measuring effective porosity of a porous media. On the basis of the numerical calculation, the timelag, required for gas flowing out to the half steady state from the time of the inlet pressure to rise to the half, was related to the characteristics of gas flow such as effective porosity, permeability and so on.
Present method was successfully applied to measure the three samples of porous media formed by compressing powder aluminum and powdered coal. By flowing gases uniformly through each samples, permeability, Klinkenberg's constant, effective pore-area and mean pore-radius were measured. And each Effective porosity and tortuosity were determined on the measured timelag of the transientoutlet flow which was generated by giving impetuous inlet pressure.

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Optimizing the control of failure process of rock under uniaxialcompression testing using a linear combination of stress and strain as the control variable model analysis of servo-controlled testing machine was conducted in this study.
At first stage, supposing a linear rock model, the characteristic polynomial of the machine-rock system was obtained and examined to reduce;
1) The control performance is influenced by the relaxation time of rock, the slope of stress-strain curve and the response time (natural frequency) of testing machine.
2) The relaxation time is found to be a function of control speed. So that the control performance is greatly influenced by the control speed.
The computer simulation was conducted using a non-linear visco-elastic rock model which was recently proposed by authors. The calculated results were compared with the experimental results. It was found that the non-linear simulation model is suitable, and mainresults of simulation are summarized in a diagram for quick reference.

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The purpose of this underground measurement of strain waves generated in a coal seam by a shot is to evaluate the stress values around the shot point. The results obtained from this measurement and some considerations are as follows;
(1) Under the charge of 400 g Eqs explosives, it was found that the relations between the distance from shot point and the stress values were;σ_rmaxσ_o=-4.62×10⁵ (r/r_o)^-2.05σ_θmax/σ_o=7.49×10⁴ (r/r_o)^-1.72According to above experimental equations, as the stress wave travels outwards, its stress level decreases rapidly as the result measured in the rock by the other researcher.
(2) It is considered that the coal seam breakage like fall down or slip out after.shotfiring might occur by the stress addition of shot to the rock pressure. In the direction of the axis of maximum principal stress, composition of rock pressure and shot stress might occur most effectively.
(3) The most effective method to prevent the unlikely destruction of a coal seam after shotfiring is not to arrange shot holes near the unstable coal seam portion especially around the top of the driving face because the stress bya shot decreases quite markedly according to the increase of thedistance from the shot point.

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The reactivity of alkaline and alkaline-earth metal ions by dawsonite [NaAlCO₃(OH)₂] and the collection of lithium contained in actual hot ground-water by this mineral were studied.
The emphasis of these studies is on the following:
1. Dawsonite captures selectively Li⁺among the alkaline metal ions above pH 8.
2. The alkaline-earth metal ions are well captured above pH 6 with little selectivity among them.
3. The amount of lithium captured depends mainly upon solution temperature and lithium concentration. The highest amount is obtained at about 50°C when the concentration of lithium is less than 20mg/l.
4. The selective capture of Li⁺is mainly caused by the chemical reaction forming lithium aluminate.
5. The relatively high lithium collection percentage was obtained for the actual hot ground water: however, from the practical view point, the coexisting Ca²⁺and the soluble SiO₂ must be removed before the lithium collection because of the remarkable hindrance caused by these components.

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A ferromagnetic wire charged with alternating current in magnetic field (H_o) perpendicular to an axis and with the overall gradient along it's axis (dH/dx) is horizontally vibrated by electromagnetic force. The wire and the magnetic particles captured on it move relatively and the friction between them are reduced. The magnetic particles are transported to the place of the strongest magnetic field by magnetic force (F_mx) and deposit there. When the upward magnetic force (F_mu) acting the particles becomes weaker than gravity (F_g), the particles fall apart from the wire.
On the basis of the above-mentioned principle, single wire experiments were conducted. The results obtained were as follows;
(1) As particles were transported in state of blocks, the moving velocity (Vp) was larger than the value calculated about one particle.
(2) The moving velocity of particles were proporsional to wire amplitude (Y). When the wire fixed on both sides, therefore, is vibrated in first mode the paticles are transported more rapidly in central part than in the side.
(3) Wire amplitude is proportional to current; therefore the moving velocity of the particles is also proportional to it.
(4) The results of calculation indicated that the thickness of deposit layers (r) which the particles fall apart from the wire could be predicted by the deposit layer model.

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The present study was done for the purpose of finding any available solid reference electrode for SO₂sensor employingbeta alumina solid electrolyte. In this paper, we tried a few experiments for this sensor using two solid reference electrode, (β+β')-alumina and (α+β)-alumina.
The cells used were as follows: Pt, (β+β')-alumina in air/β'-alumina/Na₂SO₄/SO₂+O₂+SO₃, Pt (1) Pt, (α+β)-alumina in air/β-alumina/Na₂SO₄/SO₂+O₂+SO₃, Pt (1)(11) From the present experiments, the following conclusions were obtained.
1) The constant sodium activities in these solid reference electrodes were maintained for a long duration of the experiment.
2) For both cells, good straight lines were obtained between e.m.f.'s and log Pso2 within the temperature ranges from 933 to 1230 K in the cell (1) and from 932 to 1278 K in the cell (11). Especially, in the (β+β')-alumina solid reference electrode, it was shown that the cell using this electrode could be employed to determine concentrations up to a few ppm of SO₂ gases at temperatures of 932 to about 1100 K. Consequently, this (β+β')-alumina mixture is recommended for the solid reference electrode ofSO₂ sensor employingβ'-alumina solid electrolyte.
3) From e.m.f.'s of these cells, the activities of Na₂O in β-Al₂O₃+β'-Al₂O₃and α-Al₂O₃+β-Al₂O₃coexistences were respectively calculated by considering thermochemical data and compared with the others.

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The crystallization stripping of Ni-loaded Versatic Acid was studied in the presence of CO₂, in order to develop a newproduction method of fine powders and enlarge the use of solvent extraction. Simultaneous crystallization was also investiated. The physical properties of crystallized metal carbonates and the produ cts roasted in air or hydrogen gas were examined
Highcrystallization of Ni was obtained under CO₂ pressure of 5-20kg/cm², though the crystallization strippingde-pended on the various factors, such as CO₂pressure, extractant concentration, Ni concentration and the sort of strippingsolution. The extractant concentration was highly concerned in the extent of crystallization, and the crystallization ofNi decreasedwith an in crease in extractant concentrations. Thecrystallized product was found to be NiCO₃2Ni(OH)₂4H₂O₃which had themean particle size of 0.3-0.8μm and the spheric structure. The metal salt was easily converted to fine powders of metal oxide and metal at temperature of about 350°C.
The simultaneous crystallizationof Ni and Co-loaded Versatic Acid under CO₂pressure gavethe finely dispersed complexmetal carbonate, irrespective of theconcentration ratio of Ni and Co in the initial organic phase. The metal powder from reduc-tion of the complex metal ca rbonate was found to be alloy powder containing Ni and Co.

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Copper (II) in an ammoniacal solution comaining 5 g/dm³Cu and 3 N NH₄OH was eliminated by precipitating CuS ata controlled pH of 10 and at 50°C (323 K) by disproportionation reaction of activated sulphur powder containing isotope 35S. The progress of the elimination was monitored by measuring the suspension potential (SCE). Intermediate sulphur compounds formed during the reaction were identified by means of thin layer radiochromatography and their concentrations were semiquantitatively determined using autoradiogram and a 2πgas flow counter.
The reaction involved were closely related to the suspensionpotential. In the range-0.07 (start)-0.13V, S₄O₆^-2and S₃O₆^-2 (maximum concentration: 0.003 and 0.002 mol/dm³, respectively) were found in the solution, but not SO₂^-4 and S₂O2^-3.An unknown S species, which did not migrate on a plate by development, wasalso found. This S species was considered to be a complex involving the thionate anions. At-0.13 V, S₄O₂^-6and the S species disappeared, S₃O₂^-6decreased, and S2O2-3 appeared. These S₂0₂^-3and S₃0₆^2-were stably present in the solution at constant concentrations (0.028 and 0.0008mol/dm, respedtively) until the suspension potential approached a final value of-0.34V.
It seemed that the precipitation of CuS had no relation to the changes of the sulphur compounds described above. For 4 times of repeated experiments, the precipitation proceeded at a nearly constant rate (0.6g/h), however an induction period was shortened. The precipitation wascompleted at-0.23 V. The following reactions have been considered. Above-0.13 V: 10 Cu (NH₃) ₄²⁺⁺17 S+12 H₂O=10 CuS+S₄O₂^-6+S₃O_2-6+40 NH₃+24 H⁺at-0.13V: 2 S₄O₂^-6+2S+3 H₂O=5 S₂O₂^-3+ 6H⁺2 S₃O₂^-6+4S+3 H₂O=5 S₂O₂^-3+6H⁺and in the range-0.07-0.23 V: 2 Cu (NH₃) ₄²⁺⁺4 S+3 H₂O=2 CuS+S₂O₂^-3+8 NH₃+6H⁺

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