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The Ar-SF6 inductively coupled thermal plasma (ICTP) at atmospheric pressure was successfully generated for different SF6 admixture ratios in order to investigate the quenching effect of SF6 injection on thermal plasma from the viewpoint of elucidating a remarkable interruption ability of SF6. Spectroscopic observation was carried out to measure the radial distributions of the radiation intensity of Ar lines and temperature for the Ar-SF6 ICTP. It was found that only 0.5% SF6 injection caused a 1/2 decrease in the radiation intensity and 1000 K decline in the temperature on the centre axis at 10 mm below the coil end. A two-dimensinal hydrodynamic model was developed for Ar-SF6 ICTP to simulate flow and temperature fields on the assumption of the local thermal equilibrium. The results obtained from the calculation indicated that a little SF6 addition to Ar ICTP decreased high temperature area above 9000 K drastically. This temperature decaying tendency agreed with the experimental results.

This paper deals with a novel method of calculating radiation dose rate within a building and around its surroundings. We employed the Monte Carlo method to calculate the direct gamma rays absorbed in an object. The buildup fluxes caused by the Compton scattering were simply treated with the buildup factor as a function of the mean free path of photons. The proposed method was benchmarked for a simplified geometry case and compared with the point-kernel integration code QAD-CGGP-A. The results of both methods were in good agreement. The proposed method could be used for predicting radiation dose rate in the fission products deposited areas.

Microcapsules containing tri-n-octylamine as an extractant with the diameter of less than 25μm were prepared by using SPG membrane emulsification and insitu polymerization method. The morphologies of microcapsules, the encapsulation efficiencies of tri-n-octylamine, the extraction properties of palladium （II） from hydrochloric acid solution and the back extraction properties of palladium （II） from microcapsules were investigated. The average diameter of obtained microcapsules was about half of the pore diameter of SPG membrane. The encapsulation efficiency of tri-n-octylamine was approximately 100% for all the microcapsules prepared in this study. Therefore, it can be said that there was practically no loss of tri-n-octylamine during the preparation of microcapsules. All microcapsules prepared in this study reached forward extraction equilibrium within 5 minutes and the forward extraction ratio reached nearly 1. The back extraction of palladium （II） from microcapsules was carried out using 0.1M-hydrochloric acid solution containing a prescribed amount of thiourea. The back extraction occurred promptly and the back extraction ratio was high enough to elute all palladium （II） out from the microcapsules. Furthermore, by repeating forward and back extraction experiments, the durability of microcapsules was examined. From the result, it can be said that tri-n-octylamine was encapsulated rigidly and there was no leakage during extraction and back extraction experiment. Thus it seemed that the microcapsules were capable to be used in a repeated operation.

application/pdf ギ酸濃度が銅の腐食に及ぼす影響を調べるため，濃度1～10000 mg/L ギ酸溶液中に銅管を最長84日間浸漬した．試験溶液中の銅イオン濃度を測定し，銅溶出速度を求めた．1～1000 mg/L ギ酸溶液中の銅イオン濃度はある一定値に飽和する一方，5000，10000 mg/L ギ酸溶液中の銅イオン濃度は浸漬日数の増加とともに上昇する．84日間浸漬後の銅管に発生した腐食の形態は，1～1000 mg/L ギ酸溶液の場合は蟻の巣状腐食であり，5000，10000 mg/L の場合は全面溶解であった．試料の重量減は溶液のギ酸濃度が増すにつれて増加する傾向を示した．Copper tubes were immersed in formic acid solutions ranging in concentration from 1 to 10000 mg/L for up to 84 days to investigate the effect of concentration of formic acid on copper corrosion. Concentrations of copper ion in test solutions were measured to determine the dissolution rate of copper. Concentrations of copper ion in formic acid solutions from 1 to 1000 mg/L were saturated in a certain value, while concentrations of copper ion in 5000 and 10000 mg/L formic acid solutions increase with an increase in immersion period. Corrosion form of copper tubes soaked in formic acid solutions from 1 to 1000 mg/L was an ant's nest corrosion, while the uniform attack occurred on copper tubes soaked in 5000 and 10000 mg/L formic acid solutions. Weight losses of specimens have a tendency to increase with increasing concentration of formic acid.

This paper presents new developed noise reduction methods and results of partial discharge detection and measurements of electric power apparatus using digital signal processing techniques. We have examined noise diminution by the algorithm in laboratory based on measurements of PD signals in SF6 gas and real noise as well as interference in practical HV and EHV substations. Consequently, the techniques, enabled us to reduce sinusoidal continuous noise considerably, so that they are promising for future application in actual HV substations.

application/pdf Improvement of the generation power in micro-hydraulic turbines is shown in the range of low flow rate and low head using a new inverter generation system. The generation power can be obtained down to very low flow rate and head using the new inverter generation system with variable rotational speed control, where a water turbine connot produce the electric power in a normal constant-speed-control system. Experiments were carried out using a practical micro-hydraulic turbine with 2 kW output and variable rotational speed in a forest on the mountain, Mie University. The total efficiency is kept at a high value even in the very low partial load area. Compared with the constant speed control, the generation power is improved over 20 percent by varying the rotational speed.

Establishment of an early trouble diagnosis system is demanded to prevent damage of wind turbine generator. Therefore, AE signal occurring by the damage of a wind blade was detected with the AE sensor which installed to the body of wind turbine generator and a pole. In this study, length of a blade of a small wind turbine generator was changed as simulated trouble in the constant wind velocity. The AE signal which occurred at this time was measured with an AE sensor. The signal was processed by FFT analysis, and a change of spectrum strength was examined. Then, trouble diagnosis technology of 50W grade small wind turbine generator was developed. As the results, a method to count the number of times more than threshold of AE signals was suggested by a wave pattern of an AE signal. It was understood that the number of the count was decided as standard to judge normality or abnormality of 50W grade small wind turbine generator.