Zn$_4$SnSe$_{6}$ and Zn$_4$SnSe$_{6}$ :Co$^{2+}$ single crystals were by the chemical transport reaction method. They crystallized in the monoclinic structure. The direct energy band gaps of the Zn$_4$SnSe$_{6}$ and Zn$_4$SnSe$_{6}$ :Co$^{2+}$single crystals at 289k were found to be 2.146eV and 2.042eV. Optical absorption due to impurity in the Zn$_4$SnSe$_{6}$ :Co$^{2+}$single crystal was observed and described as originating from the electron transition between energy levels of Co$^{2+}$ion sited at T$_{d}$ symmetry point.y point.

The multi layer spiral inductors, which enhance the quality factor Q of an inductor fabricated on the silicon substrate, has been designed using a TSMC CMOS 0.2sum 1-poly 5-metal layer technology. To investigate the performance of the designed inductors, a 2.5-dimensional field simulation tool(Momentum) is used. The simulation results show that the quality factor Q of the 5-metal inductor is improved 1.8 times over that of a convention31 spiral inductor at 2GHz for wireless LAN applications.

Recently the research for utilization of waste heat produced from electric power plants, casting factories, heat treating factories or commercial building are being afforded by the need for energy saving. The objective of this study is to develop a thermoelectric generation system which converts unused energy from close-at-hand sources such as garbage incineration heat and industrial exhaust etc. into electricity. This paper presents a thermoelectric technology on a optimum system design method and efficiency and cost effective thermoelectric element on order to extract the maximum power output from energy conversion of waste energy. It is shown that the longitudinal stresses of module contacted with two point constrained AI tubes could be released more than those with a one-point constrained.

Design and test results of a VRAG(Vacuum Rotary Arc Gap) switch were presented. To control the damage of electrodes caused by the vacuum arc, Lorentz's force by the radial magnetic field between spiral electrodes was used to rotate the vacuum uc. VRAG switch electrodes were made of the material of CuCr and OFHC. Gap distance between two spiral type electrodes for the rotation of the arc discharge is 8, 10, 12mm. In the cathode, one trigger electrode was inserted into each spiral wing. Normal operation of the VRAG switch was confirmed with 10.6[$mutextrm{s}$]of trigger delay and 2~3[$mutextrm{s}$] of the jitter time. The speed of the vacuum arc was measured to be 0.6 ~ 1[km/s] by a motion analyzer.

Gas insulated switchgear(GIS) is an important equipment in a substation. It is highly desirable to measure a partial discharge(PD) in GIS which is a symptom before insulation breakdown occurs. The issue is that the PD signal is weak and sensitive to external noise. In this paper, the algorithm for detection of PD in GIS using wavelet transform is proposed. The wavelet transform provides a direct quantitative measure of spectral content, "dynamic spectrum", in the time-frequency domain. The recommended mother wavelet is 'Daubechies' wavelet. 'db4', the most commonly applied mother wavelet in the power quality analysis, can be used most properly in disturbance phenomena which occurs rapidly for a short time. Through the procedure of wavelet transform, noise extraction and reconstruction, the signal is Analyzed to determine the magnitude of PD in GIS. In experimental results, we can know that partial discharge is exactly detected in combination of Dl and D2 using wavelet transform.transform.

In this paper statistics on the radiation field waveforms produced by stepped leaders just prior to lightning return strokes were described. As a parameter of stepped leader pulse characteristics, the time interval between the final leader pulse and return stroke peak, the pause time between stepped leaders, the ratio of the final leader peak to the return stroke peak and the stepped leader pulse width at half maximum were examined. The average time intervals between the final leader pulse and return stroke peak were about 16.2 and 14.8$mutextrm{s}$ for the positive and negative polarities, respectively. When the stepped leader approaches closely to ground, the time interval between leader steps was decreased and the mean value was about 17$mutextrm{s}$, and the present results were in reasonable agreement with the data observed in Florida and Japan. The large fraction of the ratios of the final stepped leader pulse to the lightning return stroke peak were distributed over the range from 5 to 35% and in average the ratio of the final leader pulse to the return stroke peak was 17.4$\pm$11.9% for the positive and 18.5$\pm$9.4% for the negative electric field waveforms. In addition, the mean pulse widths at half maximum of the stepped leaders are 1.4Us with a standard deviation of 0.9 for the positive Polarity and 2.2us with a standard deviation of 1.2 for the negative polarity, respectively.

Arresters are deteriorated by overvoltages or impulse currents, and the resistive leakage current of arresters increases as the deterioration of the arrester progresses, showing an increase in the 3$^{rd}$ harmonic component of the leakage current. In this reason, arrester diagnostic techniques based on the 3$^{rd}$ harmonic leakage current as a reference parameter of deterioration are widely used. The technique, however, includes an error due to the harmonics of power system voltage. Therefore, the influence of the harmonics on arrester diagnostics should be considered. In this paper, we designed a PSpice ZnO arrester model to simulate the influence of the voltage harmonics described above. A pure sinusoidal voltage and its the 3r harmonic voltage were applied to the model, and the leakage current components were analyzed. From the simulation results, it is confirmed that the peak value of resistive leakage current depends not only on the phase of the 3$^{rd}$ harmonic voltage but also on the magnitude of it. Consequently, the errors caused 1)y the harmonic voltage could be minimized by correcting the magnitude of leakage current upon analyzing the harmonics.cs.

The radiating multislotted antennas widely used in the antennas technique are rather prospective for the application in industrial installations for microwave heating. In this paper, the model of such an antenna is experimentally investigated. The model under investigation presents a section of the waveguide Inn 340 whose broad wall contains 15 movable slotted plates. This design allows to experimentally define a location of all the slots providing the necessary distribution of radiating power along the waveguide with minimal SWR of all the system. The variants of power uniform distribution along the waveguide as well as the power decreasing to the waveguide end are examined. The application of plates with different thickness allowed to estimate the influence of the walls thickness on the Power distribution. The possibility of system extra-tuning with the help of tuning screws located in the vicinity of each slot is considered. Obtained results are compared to the conducted theoretical calculations and data in references.

With the progress of optical communication technology recently, the development of micro actuator using MEMS technology has been made for optical switching. The actuation types are various; electrostatic, electromagnetic, and electrostatic +electromagnetic etc. Among them, the electrostatic type is the most popular because of the relative ease of fabrication, integration and shielding as well as low power consumption. However, it needs a high voltage to generate a larger driving force. To overcome this problem, we proposed a new type of electrostatic actuator with an extra vertical electrode in addition to the horizontal one. The vertical electrode also lays a role of making the stable angular rotation as a stopper. From the theoretical analysis and experiment, we find the actuation voltage can be reduced up to 50 % of that of the conventional one.