Recently, sewer pipelines are mostly separated into pipeline for sewerage and pipeline for storm water. Pipelines for sewerage are required to have high durability, good chemical attack resistance and high strength as well as lining economical.
The reinforced concrete pipes manufactured in Japan are mainly medium sized 250-1500mm diameter centrifugal spun pipes, known here as Hume pipe. However since concrete and steel are highly effected by chemical attack pipe corrodes easily under environment of pH 4 and lower. Such acid environment is often created by action of bacteria, etc. within the pipe.
Ore laboratory has conducted studies on lining hardened concrete, lining fresh concrete, coating a thin vinyl chloride lining and other composite pipe system for corrosion protection.

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Monolayer polyimide films containing azobenzene were prepared on SnO₂- coated glass substrates by using the Langmuir-Blodgett technique. We have examined the electrical properties of precursor films of polyimide (AZBPAA) and polyimide films (AZBPI). The displacement current due to trans-cis photoisomerization was generated by alternate irradiation with UV light and visible light in AZBPAA LB films. In contrast, the displacement current was not generated in AZBPI LB films, because the photoisomerization was not initiated and the transportation of photoexcited electrons in the films was negligibly small.
The displacement current due to the photoexcited electron transfer between AZBPAA monolayers and electrodes was found to be generated only in the initial photoirradiation by introducing an electrically insulating film (PIBM LB films) between AZBPAA monolayers and electrodes. It was concluded that motion of charged particles can be purposefully controlled and be detected by the displacement current measurement.

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In previous paper, a perturbed-hard-sphere equation of state (PHS-EOS) have been successfully applied to correlate the solubilities of high-boiling compounds such as coal liquefaction products in supercritical fluids.
In this paper, the PHS-EOS with the mixing rule based on the local mole fraction concepts is applied to correlate vapor-liquid equilibria (VLE) of systems containing a strong electrolyte such as calcium chloride. The purpose of this study is to examine the flexibility of EOS for correlating VLE of systems containing non-volatile strong electrolytes. A simple method was proposed to determine constants a_s, b_s and c_s for calcium chloride.
It was found that the salting-out and salting-in effects on these systems by calcium chloride can be illustrated by adjusting the characteristic binary constants k_ij and a_ij

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A sol-gel process was applied to prepare Co-Mo/SiO₂ catalysts, a typical hydrocracking catalyst, from tetraethyl orthosilcate and aqueous mixture of Co (NO₃) ₂ and (NH₄) ₆ Mo₇O₂₄. The modefication of the process with addition of water-soluble polymer at the start of the process enabled the control of a pore size distribution of the catalysts.
Solvent refined coal (SRC) prepared from Taiheiyo coal was hydrocracked under H₂ atmosphere with the catalysts prepared. Their SRC hydrocracking activities were considerably different depending on pore size distribution of them. The effect of their pore size distribution on the catalytic activity was discussed.

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The stirred mill is regarded as one of the most efficient devices for micronizing materials and have come to be actively used for preparation of fine particles. Recently, a demand for ultrafine particles is increasing in many kind of industries.
In this paper, based on frictional action of feed material each other, an autogenous grinding to get submicron or micronized particles have been carried out using a stirred mill (Attritor-type D). The mill used was made of stainless steel and its volume was about 5.5 liters. The mill held 12 impellers. In the present work, two operating parameters such as stirring speed and feed size of limestone were used. The feed mass was 5 kg and three different feed size were chosen for this experiment: 6.7-10, 10-13, 13-20mm. The rotational speed of impeller examined were 69, 103 and 139 rev/min. The ground products were sieved in the size range from feed size to 149, u m, and from 149 to 0.17, a m, the size distributions were measured by a laser diffraction and scattering method
The torque reading were recorded during each experiment, and the area under the torque vs. grinding time curve was used to give a measure of the total energy input to the mill. The grinding time were 2, 4, 10, 25, 40, 60 and 180 min. The progress of grinding was evaluated by the increasing rate of submicron or micronized particles in products.
The results are summarized as follows
(1) The zero-order equation was applicable to the increasing rate of submicron particles in earlier grinding time. (2) The energy consumption to get submicron particles decreased with increase in the feed size at all speed of impeller.
(3) It was minimum when the feed size was 13-20mm, that is, close to the distance between the top edge of impeller and the wall of mill. (4) The following experimental equation was obtained. Q₁= (5.6×10^-9-3.2×10_-11n) E·x_fm where Qi is the mass fractiom finer than 1μEm, n the rotational speed of impeller, E the energy consumption and x_fm the maximum size in the feed.
(5) It was found the an autogenous grinding with a stirred mill is an effective method producing submicronized limestone.

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The effect of grain boundary inclination on intergranular corrosion in boi-l ing HNO₃+Cr⁶⁺ solution was investigated on Alloy 690 with coarse columnar crystals. As the deviation of the growing direction from ‹100› orientation was within 10°, the grain boundaries were treated approximately as simple tilt boundaries with ‹100› rotation axis. The depth of intergraunlar corrosion, h, showed a tendency to increase with increasing the relative tilt angle, ω. At the symmetrical tilt boundaries, h decreased at coincidence boundaries such as Σ13 and Σ17 against the normal relation of h with ω. It was found that grain boundaries of which the planes are close to {100} or {110} of both component crystals have lower susceptibility to corrosion. And at the boundaries with ω which is less than 10°, h was small. The groove angle of intergranular corrosion decreased with increasing h. The groove width of intergranular corrosion on the surface did not depend on h so much.

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Effects of impurities and firing atmosphere on the electromagnetic properties of low temperature sintered NiCuZn ferrites have been studied with reference to their microstructures. It is shown that a low oxygen partial pressure during firing is effective to achieve a high quality factor of a NiO-rich NiCuZn ferrite for high frequency use. This can be responsible for the less interference fringes at the grain boundaries. TEM observation indicates that CuO and CoO are enriched at the central part of interference fringes. Moreover, the quality factor is strongly affected by impurities or a small amount of ingredients such as CoO, MnO, and P.

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Ionic conductivity of Na⁺ in β-or β″-Al₂O₃ is affected by their densi-ties.This paper deals with the influence of the particle size and the admixture (ZrO₂, HfO₂, Ta₂O₅ et al.) on the density of the samples and the ionic conductivity of Na+ in β″-Al₂O₃.
The ionic conductivities of Na+ in non admixed and admixed β″-Al₂O₃ were measured using an ion blocking electrodes (Au), and then arrhenius plots were made for ionic conductivities at various temperatures.
As the results, it was observed that the ionic conductivities of the samples increased with those densities. Also it was found that the admixture concentration has a limited value for the ionic conductivity.

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Barium titanate precursor gel was successfully obtained by a sol-gel process with the use of barium acetate and titanium isopropoxide as starting materials. The calcination process of the barium titanate gel was characterized by FTIRPAS, TG-DTA, XRD and acid extraction method. These analyses indicate that barium acetate was distributed uuiformly in the gel matrix formed by hydrolysis and polymerization of titanium isopropoxide. The barium titanate was formed rapidly at higher temperatures than 823-873K resulted from the reaction between titanium oxide and barium carbonate or barium oxide.

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A breaker is a machine used to break rocks in the mining and public works.
In the field of these works the oil hydraulic breaker is selected corresponding to the crushing strength of rocks.
Recently, in order to control the mining machines automatically, it is requested that the design of the oil hydraulic breaker should correspond to the wide range of crushing strength of rocks.
In this paper, the perforemance test of a commercial oil hydraulic breaker is treated, and the influence of a change of the stroke of the piston on the blow energy is examined theoretically and experimentally. It is shown that a new type of the oil hydraulic breaker with variable piston-stroke can be designed for breaking wide variety of rocks

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Phosphor Y₂ O₃: Eu₃₊ particles were prepared by a wet chemical method from yttrium isoproxide and europium nitrate as starting materials. Europium was effectively doped into host material while hydrolysis of yttrium isopropoxide with europium nitrate tended to generate the small and agglomerate particles compared to those obtained from alkoxide only. The decomposition terminated at the calcination temperatures of 600-700°C for residual organic matter in precipitate, and then crystallization began to proceed with temperatures. The fluorescence peak at 611 nm was observed for the prepared Y₂ O₃: Eu₃₊ particles above the temperatures of 600°. The peak intensity increased with the calcination temperature corresponding to the progress of crystallization.

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The role of work functions in electron emissive materials is very important. A high emission current density can be obtained from thermionic emission materials (thermionic cathodes) having low work functions and kept at high temperature. The figure of merit is, thus, the work function divided by the melting temperature of the meterial. In the case of field emission (cold) cathodes, the magnitude of the work function is not as important as its time variation, which creates field emission current fluctuation (noise). The reduction of the current fluctuation is, hence, the major issue of the development of field emission cathode materials.

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