This study deals with the apparent resistivities measured by both Dipole arrays and Schlumberger array which is frequently used in resistivity sounding. Both have a connection with each other, which is shown by the equations of reciprocity between various electrode arrays, in the form given by Al'pin. These can be approximated as a linear summation by replacing their differential coefficients with formulae obtained by the use of the Lagrange interpolation polynomial. It is shown that this approximated transformation equation, which provides the Resistivity Sounding (RS) curve for the Dipole array from that obtained with the Schlumberger array, is adequate. Furthermore, the automatic interpretation method of Schlumberger RS curves which is an iterative one employing a non-linear least square technique can be applied to the automatic interpretation of Dipole RS curves, using the approximated equation stated above.
This paper contains a discussion on the above mentioned concepts, and the results of simple model experiments as well as ground measurements are included as case studies.

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Water content in a rock sample has a strong influence on the fatigue crack growth behavior. In order to investigate this effect, corrosion fatigue tests at room temperature were performed on granitic rock samples, containing various degree of saturation.Furthermore, mechanical fatigue crack growth rate in an inert environment was determined to evaluate the effect of water content more quantitatively.Corrosion fatigue crack growth rates can be represented by Paris' law as follows.
da/dN|_CF=D (ΔK) ^m (m=22.5).(1)
where D is a parametric constant depending on environment and frequency, ΔK stress intensity factor range and mconstantd etermined experimentally.Considering the effects of water content and mechanical variables, such as loading frequency and stress ratio, on cyclic crack growth rate, the following empirical relation was obtained.
da/dN|_CF=D (Sr, f) D'(R)(ΔK) ^m.(2)
where D is a function of loading frequency (f) and degree of water saturation (Sr) and D'is a function of stress ratio (R). Taking Walker's model into consideration, equation (2) can be rewritten in terms of effective stress intensity factor range (ΔK_eff).
da/dN|CF=D (Sr, f)(ΔK_eff) ^m.(3)
whereΔK_eff=K_max(1-R)ⁿ (n=0.1)
Mechanical fatigue crack growth rate in the inert environment, where a constant D in eq.(1) shows a constant value D₀ independent of loading frequency, was determined as follows.
da/dN|_inert=D₀ (ΔK_eff)^m (D₀=2.6×10^-7).(4)

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To compare the new type slurry explosives with conventional type permitted explosives, the safety tests were performedb y several series of the suspension method and the mortar and the angle shot mortar methods. From the experimental results and the consideration on the effect of blending contents, detonation velocity, and specific gravity of the slurry explosives, wecon clude as follows:
1) The 400g class and the 600g class slurry explosives are both inferior to those of the conventional explosives in the safety on suspension method.
2) On the angle shot mortar test of Eq.S-1 class, the slurry explosives are also inferior to the conventional ones. By the enactment about the new explosives safety test method for the permissible slurry explosives, however, several new slurry explosives have had the same safety standards to the conventional explosives.
3) Through the experiments and the discussion of the results, following analytical relations between the parametric factors and the safety of slurry explosives can be concluded;(1) the ignitability of coal dust depends on the quantity of flash reducing agents or sodium nitrate, (2) methane ignitability changes with the ratio of water and salt, the ratio of ammonium nitrate and water or the ratio of ammonium nitrate and aluminum powder, and (3) methane ignitability also changes with the increase or the decrease of the density of slurry explosives.

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In a slurry pipeline deposition occurs on the bottom of the pipe at flow velocities below the critical deposit velocity. If the discharge is then gradually increased, particles at the surface of the bed are removed by flow to reduce the height of the bed. However, at certain flow conditions the bed begins to slip at the pipe wall, giving rise to a sliding bed flow.
The object of this paper is to provide accurate predictions of mechanical friction forces which must be overcome in order to set the bed in motion. The forces which act on the pipe wall were analysed, assuming that the state of stress in the bed is on a condition of plastic equilibrium and that the driving forces of the bed are equivalent to the mechanical friction forces which hold the bed in place. As a result, driving forces of the bed FT for θb <π/2 were given by
Ft=2r²μwγ∫₀^θbE(Ksin²θ+cos²θ)dθ dE/dθ={1+(K-1)sin²θ}μwE-sinθ
where μ_w is the friction coefficient between solids and the pipe wall, and K is the coefficient of particles (or earth) pressure at rest; the dimensionless number E with respect to pressure P_v is defined with the pipe radius r and the specific weight of the bed γ by E=P_v/(γ-r), and θb is a half of the center angle against a surface of the bed taken as a chord. The solution of these equations was provided numerically, and also analytically as in approximate one.
Experimental verification for this theoretical analysis was then performed.
The granular material used in the tests was a sand of specific gravity 2.66 and mean diameter 1.71 mm. Friction forces occurring between the sands and the pipe wall were measured in 3.2cm and 4.0cm transparent plastic pipes with a pair of cell keeping the bed at any height within it. Comparison between experimental results and theoretical values for the friction forces showed good agreement if 7 was calculated by the following equation:γ=C γ _s+ (1-C)γ _w
where Cis the volumetric fraction of solids in the bed;γ_s and γ_w are specific weights of solids and water, respectively.

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As a basic research for the application of high gradient magnetic separation, the magnetic susceptibilities were measured in room temperature for some sulfide minerals;pyrite, chalcopyrite, bornite, chalcocite, covellite, sphalerite and galena. The susceptibilities of crystalline pyrites, except 0.46 × 10^-6emu/g of colloform pyrite, gave low values of narrow range from 0.16 to 0.28 × 10^-6 emu/g, which are independent of the magnetic force.Besides, pyrites from the metamorphic and metasomatic deposits caused to vary the magnetization intensity depending on magnetic force owing to the coexisting minor ferromagnetic minerals as magnetite, hematite and pyrrhotite.Against chalcopyrite, the susceptibility ranged the values from 2.8 to 7.0 × 10^-6emu/g, but bornite showed a low value of 0.7 × 10^-6emu/g.Sphalerites showed more positive susceptibilities with the increase of iron content, and the curve followed by the values is nonlinear which is similar to the curve, given by Keys et al.(1968).Chalcocite, covellite and galena are diamagnetic substantially.Nevertheless, the first one gave positive valueof 0.04 × 10^-6emu/g and the second one 0.5 and 0.9 × 10^-6emu/g.In galena only, the negative value was found as- 0.04 ×10^-6 emu/g, but it is very small, as compared to pure synthetic PbS.It is thought that the deviations of susceptibilities of the above three minerals might have been caused by the presence of any magnetic impurity within them as iron in sphalerite.

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Most of the limestone produced is used as raw material for the cement, iron and steel industries, and various civil enginneering projects. Some of the limestone which is of very high grade could be more profitably used as paper filler than for the manufacture of cement. The present paper was thus focused on problems related to limestone pulverization for paper filler production.
(1) Limestone of high grade purity and whiteness was pulverized by the Tower Mill Pulverizer in a dry semi-continuous system.
(2) Tests were performed under various conditions in order to examine the characteristics of the pulverizing system.
(3) The increased number of revolutions of the blower mounted to the pulverizer for conveying the pulverized products increased the weight of the pulverized product while decreasing the weight percent of the-10μm particles in the product, and also increasing the weight of the -10μm products.
(4) While the increased number of revolutions of the blower caused an increase in the electricity consumption of the motor of the blower, it decreased that of the pulverizer. There was however an increase in the total consumption of both motors.
(5) The increased number of revolutions of the blower decreased the total electricity consumption per unit weight of the pulverized product and per unit weight of the -10μm product. The minimum values of the former and the latter were 0.070 and 0.641 kWh/kg, respectively.

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The extraction of copper ion was carried out using liquid surfactant membranes containing LIX65N as a mobile carrier.
A mathematical model for the extraction was proposed. In this model, W/O/W emulsion consists of a large number of oil drops containing smaller, but more numerous water droplets. The calculated results agreed with the experimental ones, and the effects of concentration of various component on the extraction rate were clarified. The overall extractionrate was controlled by both the reaction at external water-oil interfaces and the diffusion of the mobile carrier within the oil phase.
The extraction rate could be also evaluated by a simple model in which the liquid membrane consists of a single layer, considering the effective thickness of liquid membrane.

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