The ozone generation technologies with electrical discharge for higher grade equipment have been progressed and the application fields using ozone also have spread widely. Moreover the additional effects using ozone called advanced oxidation processes (AOPs) have been attracted for the treatment of organic compounds in water. The education of ozone utilization with safety is also required for the practical use of it.

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The characteristics of dielectric barrier discharge, such as lissajous figure, charging current, electric field strength and appearance of discharge were measured at various applied voltages, gap lengths using unheated discharge devices. Besides, the influence of dielectric surface temperature on discharge mode was examined. As a result, it was found that the number of micro discharges was increased at higher applied voltage and shorter gap distance. When the gap distance was 3mm, the electric field strength at discharge initiation point was about 3.2kV/mm, however it increased with decreasing the gap distance in case of the unheated discharge device. On the other hand, in case of a heated discharge device, the discharge initiation voltage decreased and current pulse became larger. At the same time, it was observed that many micro discharges were distributing in the whole discharge space and emitting strong light.

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Whereas it is not difficult to derive the impulse time parameters, T₁ and T₂, from a given Lightning Impulse (L.I.) generator, there has been no effective technique in making so conversely: to determine values of circuit components so that its output waveform can exactly have the given time parameters. With a conventional technique, one has to tabulate many intermediate values from curves composed from the double-exponential function despite a L.I. generator's output can precisely be described by the triple-exponential function. This paper proposes a generalised L.I. generator circuit, techniques to solve its circuit equation and a method to determine values of circuit constants to fulfil given time parameters. Performances of the Windows program based upon the developed method are also demonstrated.

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The standard frequency and time signal emissions in LF band began in 1999 in Japan. The bands of standard frequencies are rightly guarded from other intentional emission, but some reports show radio noise interferes with the receipt of the time signals. We observed LF band at several points, and found high level noises overlap at the some percents of time sequence. And additional search shows radio noise has two type origins. One is natural source, thunder noise, and it emits impulsive noise. But the other one, artificial origin, maintains emission during the origin works, and sometime becomes a strong disturbance.

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In IEC 61000-4-2 for electrostatic discharge (ESD) immunity testing, an ESD-gun is used to simulate the ESD events from a charged human body. The gun of this kind injects into a device under test the discharge current through a lumped resistor from a charged lumped capacitor. In actual ESD events from charged human bodies, however, the charge distributed on the body surface is discharged through a spark from the fingertip, and its situation is essentially different from that of the ESD-gun. To understand the behavior of the above-mentioned discharge current, using a 6GHz digital oscilloscope, we previously measured the current through a hand-held metal piece from a charged human body, and proposed an equivalent circuit model for calculating the discharge current with a time invariant spark resistance. In this study, with respect to the approaching speed of the hand-held metal piece, we measured discharge currents through a metal piece from a human-body with a charge voltage raging from 200V to 1000V, and estimated the resultant voltage waveforms from the above-mentioned equivalent circuit model. Through these results, in conjunction with the metal piece speed, we demonstrated the dependence on the charge voltage of current peak, current rise time, time-varying spark resistance, spark length and breakdown field. We confirmed also that the spark resistance value at the current peak time enables one to calculate the discharge current, which supports the validity of the previously proposed circuit model.

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The information understanding in communication is supposed to be concerned with the emotion. The purpose of this study is to estimate the information understanding through the nasal skin thermogram which reflects the human emotion. The local fractal dimension analysis was applied to the nasal skin thermogram. Based on the relationship among the local fractal dimension and the subjective understanding measured in English listening tests, the information understanding has been estimated by the linear multiple regression. As a result, the estimated understanding has been obviously classified in two groups according to the difficulty of the test. Additionally, we have shown that the local fractal dimension of the nasal skin thermogram is the individual independent factor for the infomation understanding estimation.

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A pulsed ion-beam evaporation (IBE) technique is used to ablate Si species from bulk Si target onto quartz substrates. Large round-shaped droplets up to a few μm are predominantly formed in vacuum, whereas introduction of He gas could result in formation of particles with decreased size up to a few hundreds nm. A slight oxidation of Si particles is found even in vacuum condition, revealed by surface composition analysis using X-ray photoelectron spectroscopy (XPS). Note that the presence of He ambient obviously promotes the oxidation of as-deposited Si species. The changes in morphology and composition of formed Si particles are attributable to an enhanced interaction between ablated Si plume and the ambient gas with an increased pressure.

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A probe with a magnetic yoke for nondestructive evaluation of mechanical properties was developed. This probe can evaluate magnetic properties of ferromagnetic materials without machining them to a shape of ring core or frame core, that is, in-situ measurements. In this paper, magnetic properties measured by the magnetic yoke probe were compared with mechanical property. The magnetic properties measured by the probe have a good correlation with those mechanical properties. This shows a potential to apply the probe to NDE of mechanical properties in ferromagnetic materials. The effect of air gap between the probe and the specimen was also investigated, to consider the problem of contact in practical use.

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In magnetocardiogram (MCG) measurements, magnetic noise from the wire used to suture the sternum after heart surgery becomes a problem. Independent component analysis is effective as one method of noise rejection.
In this study, MCG measurements were made with the wire attached to a normal subject and with the wire not attached. We performed signal processing by independent component analysis in order to reduce the effect of magnetic noise from the wire. Comparison of the waveforms after this signal processing with waveforms where the wire was not attached, clearly showed that magnetic noise from the wire was reduced.
This result clearly shows that independent component analysis is effective for removal of magnetic noise from the wire.

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This paper describes the effects of polarity of applied voltage on electrical conduction and space charge formation up to electric breakdown in one-sided acetophenone-coated low-density polyethylene (LDPE) film. At the field before electrical breakdown, negative space charge accumulation was formed in the bulk regardless of the polarity of electrode with acetophenone coating. The field at positive electrode was larger than the field at negative electrode and that field in case of negative acetophenone-coated electrode was more enhanced than applied field. The dielectric constant is evaluated by Schottky-plot on the field near breakdown field modified by the space charge effect at both electrodes in acetophenone-coated LDPE film, which is about 2 to 9. The value of dielectric constant evaluated on the field modified by the space charge effect at acetophenone-coated electrode is especially in the same order to the value (about 3) obtained by capacitance measurement. From this result, it is considered that high field conduction in acetophenone-coated LDPE is affected by the carrier injection or extraction at acetophenone-coated electrode.

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The paper proposes an application of elliptic function to a new measuring method of electric resistivity of outer-semiconductive layer of XLPE cable. The new measuring method may substitute the conventional method.
The resistivity can be obtained easily by measuring resistance between two electrodes which are attached to a circumferential edge on one side of the outer-semiconductive layer of a cable core sample. The solution process is applicable to heat conduction as well as hydromechanics.

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The purpose of this paper is to introduce a new eddy-current testing technique for surface defect detection in nonmagnetic metals using magneto-optic crystal and exciting coil (magneto-optic eddy current probe, MOECP). The magneto-optic eddy current probe could measure the slit depth of the 0.1 mm with the signal-to-noise ratio (SNR) at 16.8 and detect the slit interval with high spacial resolution.

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Induced currents in the high-resolution, anatomical human models are numerically calculated by the impedance method. The human models are supposed to be exposed to highly inhomogeneous 20.9 kHz magnetic fields from a household induction heater (IH). In the case of the adult models, the currents ranging from 5 to 19 mA/m² are induced for between the shoulder and lower abdomen. Meanwhile, in the case of the child models, the currents ranging from 5 to 21 mA/m² are induced for between the head and abdomen. In particular, the induced currents near the brain tissue are almost the same as those near the abdomen. When the induced currents in the central nervous system tissues are considered, the induced currents in the child model are 2.1 to 6.9 times as large as those in the adult model under the same B-field exposure environment. These results suggest the importance of further investigation intended for a pregnant female who uses the IH as well as for a child (or the IH users of small standing height).

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