The measurement of oxygen radical density in O₂-N₂ mixture gas weakly ionized plasma by using a simple platinum made thin wire sensor has been carried out. The increased temperatures of the platinum wire caused by the released energy of the recombination reaction process of two oxygen radicals on the platinum surface have been measured by varying the nitrogen gas mixture ratio and compared with the oxygen radical densities theoretically calculated in the same plasma conditions. Moreover, the relation between the thin wire temperature and the oxygen radical densities has been also cross-checked by the quantitative measurement of oxygen radical densities using a quadrupole mass spectrometer. All these results made us possible to determine the oxygen radical density experimentally solely from the platinum wire temperature. The influence of ambient gas temperature on the radical density measurement has been also examined and discussed.

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Increased use of factory automation (FA) apparatus raises concern over electromagnetic interference among electronic devices at the industrial sites. The purpose of the present paper is to discuss modeling of electromagnetic environment inside a factory building via Finite Difference Time Domain (FDTD) method. The principal noise frequency radiated by an inverter-motor system in the building is between 1MHz and 10MHz. Three-dimensional simulation code is verified against measurement of magnetic field distribution inside a simulated building and a laboratory. Effect of wire reinforced concrete wall on the numerical modeling is discussed. As long as the noise source is far away from the wall, the reinforced concrete wall can be modeled as a simple metallic wall reflecting the electromagnetic wave of the frequencies between 1MHz and 10 MHz. When the noise source is embedded inside the wall, however, each reinforcing wire must be modeled.

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Peripheral plasma electrostatic fluctuations are studied with inserted electrostatic probe array in the STP-3(M) Reversed Field Pinch, and radial profiles of electron density, electron temperature, and plasma space potential are measured. The particle flux driven by electrostatic fluctuation is calculated with the correlation between the fluctuation of electron density and fluctuation of plasma space potential, bringing us the results that the increase of electrostatic fluctuation at the edge causes particle diffusions. The agreement between the E_r×B drift velocity of the radial electric field by the gradient of plasma space potential and the ion thermal velocity at the edge indicates ion motion dominates the particle diffusion. The decrease of the toroidal phase velocity at the edge and the confinement degradation shows the radial outside flow of the E_r×B_p drift, where E_t is generated by the toroidal flow fluctuation of the E_t×B drift. Therefore, the electrostatic fluctuation caused by the radial propagation of plasma space potential is thought as the dominance of the radial particle flux.

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In this paper, induced currents in an anatomical head model exposed to a non-uniform ELF magnetic field (B-field) including harmonics are numerically calculated, and are discussed based on the basic restriction established by International Commission on Non-Ionizing Radiation Protection (ICNIRP). A casual hair dryer of 100V and 1.2kW is chosen as a typical source of the non-uniform B-field including both the fundamental and second harmonic components. The B-field distribution around the hair dryer is estimated by using the 3-orthogonal magnetic dipole moments, which are derived from a couple of measured values around it. The high-resolution human head model used is constructed based on the MRI images of a real human, and consists of six kinds of tissues (bone, brain, eyeballs, muscle, skin and blood). So-called impedance method is used for the numerical calculation of the induced current. The numerical results show that the maximum values of the induced current of 17µA/m², for the 60Hz component, which is about 1/120 of the ICNIRP basic restriction appear in the muscle near the eyeball when the hair dryer is used from the side of the head model, and the averaged current in the eyeballs that have the highest conductivity is the highest among the six tissues. It is also demonstrated that the induced current due to the 120Hz B-field becomes comparable to the 60Hz current although the magnitude of the 120Hz B-field is much smaller than that of the 60Hz B-field.

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Tribological properties of Ti-based (Ti, TiO₂ and TiN) thin films on a stainless steel (304SS) substrate were investigated at several pressures in an atmosphere of the air. Films 0.2 µm thick were prepared on a mirror-polished substrate using each method of ion beam assisted deposition, ion beam assisted reactive deposition and dynamic ion beam mixing. The tribological test was carried out with a tribo meter of a pin-on-disk type in a high vacuum chamber. The wear surface was observed with a scanning laser microscope and a scanning electron microscope. The friction coefficient of stainless steel in a pressure of 1×10⁵ Pa showed a lower value than that in 1×10^-5 Pa, because oxygen or moisture contained in the air played a role of lubrication. Also the TiN thin film in 1×10⁵ Pa showed a low friction coefficient until wearing the TiN layer on a substrate at a sliding distance of 10 m. However friction coefficients of the TiO₂ and Ti thin film were hardly dependent on a gas pressure. In the case of 5 m in a sliding distance, friction coefficients of Ti-based thin films converged on 0.3 at a pressure of 1×10^-3 Pa.

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High-temperature heat treatment of polyimide (Kapton) film yielded a highly oriented graphite film, composed of nearly ideal thin graphite layers with 6 ˜ 7nm in thickness. The graphite films assumed various characteristic forms in appearance depending on heat-treatment. The graphite films containing minute vesicles within the film were obtained starting from a thick polyimide film, which yielded a flexible graphite sheet with excellent physical and mechanical properties compared with commercialized, expanded graphite sheets.

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An investigation on residual life diagnosis system of low voltage rotating machines for elevator equipments was conducted in the purpose of predicting the insulation deterioration accidents. The algorism of presented diagnosis system follows the following process: analyze a deterioration grade based on non-breakdown data by an expert system developed before and being tried in the establishment places, estimate one more deterioration grade corresponding to the insulation breakdown time by a regression analysis on actual breakdown voltage (BDV) databases, and finally estimate a residual insulation life by a regression analysis between the deterioration grade and databases with the operation progress days. These databases were made as the results of insulation breakdown tests for 150 low voltage rotating machines removed from the various elevator operation places. This paper reports about the trial of the system that the residual insulation life is predicted with referring to the BDV databases correlated with the inputted non-breakdown data in the above process. The system performance is discussed in terms of the breakdown voltage inspection in detail.

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Surge endurance characteristics between foil conductors on printed wiring boards with and without earthed backing metal foil were studied in air at 20°C and 40-45%RH. The gap distance between the conductors ranged from 0.05mm to 2mm. The thickness of the board was 0.8mm or 0.3mm. The impulse voltage (1.2/20µs) was applied between the conductors. The experimental results show that the flashover on the board without backing metal occurs when the electric field strength on the HV electrode edge is increased to a certain magnitude which is independent of the gap distance. For the board with backing electrode, the field strength at the flashover depends on the gap distance and increases with the gap distance except in the case that positive flashover for the board thickness of 0.8mm. The increase in the field strength may result from electric field stabilization at the conductor edge due to the large amount of homo-charge on the board surface near the electrode edge. The calculation of the static electric field revealed that, in the case of the board with backing foil, the strong vertical field component on the board surface is produced near the sharp conductor edge by the existence of the earthed backing foil. A large number of the homo-charge stays on the board surface near the HV electrode due to the strong vertical field component on the board surface near the conductor edge.

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The surface treatment of glass substrates affects the in situ polymerization of pyrrole on them. Here, we have studied the initial deposition process for the positively charged substrates. It was found that no notable difference is induced by dipping the substrates in solutions containing one or two components of the in situ polymerization solution, prior to in situ polymerization. However, dipping in the in situ polymerization solution containing all three components, pyrrole, FeCl₃ and p-toluenesolfonic acid sodium salt (PTSNa) removed the rest time. This fact implies that the polymerization reaction of pyrrole on the substrate is required to initiate the deposition of polypyrrole. It was also observed that photoelectron emission from the substrates for which the polymerization was quenched during the rest time, indicating the depositon of oligomerized or polymerized pyrrole on the substrates although the deposition could not be detected by the optical absorption spectra.

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Our visual characteristics are affected by various visual environments. In this experiment, we examine how things look in a dense fog. Namely, 4 subjects evaluated their eyesight in a fog of four kinds of particle diameters using colored-landolt ring. Yellow color was given the best eyesight in a dense fog. In other words, under such visual environment, yellow visibility was the best. This tendency was remarkable as the diameter of a fog particle became small.

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The Ballooning mode, which occurs at a region where the plasma pressure gradient exceeds a certain limit, needs to be suppressed to achieve high β. Using a magnetic-probe system with a high spatial resolution, we measured magnetic fluctuations in a very local area to get fluctuations due to the Ballooning mode. As its result, we found that the amount of fluctuation decreased with I_tfc while I_tfc < 40 kA, but that it increased while I_tfc > 40 kA, which agreed with the earlier simulation of the ballooning mode. Analyzing the fluctuation of I_tfc > 40 kA, we found that the frequency was 0.4 - 0.8 MHz and the mode number was about 10.

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