Some experimental studies on the dielectric strength characteristics of organic material under compressive stress associated with high magnetic fields and of liquid coolant in the presence of thermally induced bubble, which might be generated at unexpected quench of immersed-cooling superconducting devices, was performed to obtain the basic data on the electrical insulation design for superconducting apparatus. PET and liquid nitrogen were used as test mediums.

본보고는 전기절연재료로 사용되고 있는 폴리에칠렌의 전기적특성의 연신효과에 관한 연구 결과이다. 전기적 특성으로서는 전기전도, 이동도, 절연파괴의 온도의존성을 파악한 것이다.

The Orientation and distribution of stilbenes and azobenzenes in bilayer membranes are disoussed. The micropolarity that the organic molecules experience is rather polar.

Theory and experimental results are presented to show the possibility of using a dielectric rod resonator method for characterizing dielectric materials at microwave frequency. The measuring structure is a resonator made up of a cylindrical dielectric rod placed between two parallel conducting plates. In this system, the TE$\_$011/ mode frequency was adapted to minimize the effect of the air-gap between the rod and the conducting plates. The dielectric properties are computed from the resonance frequencies, structure dimensions and 3-dB bandwidth.

In this paper, The preparation and characteristics of polyaniline/Zn battery by (NH$_4$)$_2$S$_2$O$\sub$8/ and used as cathod active material to investigate the characteristics of polyaniline/Zn battery. Characteristics of polyaniline/Zn battery was affected of amounts of electrolytes and additives such as graphite and carbon black.

A Thermally stimulated measurement using a temperature gradient has been applied to the study of charged particles and their polarity in polymer. Our experimental results on a cross-linked polysthylen(XLPE) film can be obtained, observing the TSC peaks of the trapped carriers in C peak determinated negative polarity that is electron.

A streaming current in liquid generated by flow electrification in a pipe is very hazardous and has to be reduced before the liquid is put into a storage tank, it was measured in pipe (${\Phi}$: 0.5mm, 0.8mm length: 1.5-11cm), it was increased as increasing pressure of Ar gas and appeared a peak value at 5cm of pipe length in 4m/sec of flow velocity.

In this paper, the theoritical breakdown characteristics of $N_2$and $SF_{6}$ in uniform field are studied by streamer criterion and the effective ionisation coefficients. Evaluation of the breakdown voltage for $N_2$and $SF_{6}$ has been done over following ranges: $N_2$: 100.0 $\leq$pd$\leq$10000.0(Torr cm) $SF_{6}$: 100.0$\leq$pd$\leq$6000.0(Torr cm) Computed values are compared with those of experiment. The results show a good agreement between the computed and the experimental values.

Epoxy, noticed as a new insulation material for electrical equipments, may become an excellent cured material from the crosslink reaction with some curing agents and accelerators. The characteristics of cured epoxy is determined by the method of lattice formation according to curing method. The purpose of this paper, varing the process of lattice formation by various surrounding temperatures and heating time during the curing process, is to obtain the optimum cured condition for electrical insulation from the results of investigation on the physical and dielectric properties of cured epoxy. In this investigation, it is found that the excessive temperature and heating time brings on the growth of metamorphic methyl and the insulating properties of cured epoxy is decreased by this phenomenon. As a result, it is concluded that the optimum dielectric characteristics can be obtained when cured at a curing temperature at 14$0^{\circ}C$ for one hour.

The effect of Mo elenent and annealing condition on the magnetic properties were investigated in Fe$_{80}$B$_{12}$Si$_{8}$ amorphous alloy. With increasing Mo contents, soft magnetic properties were improved by decreasing coercive force and increasing maximum permeability. These improvements were attributed to the decreasing of magnetostriction by Mo addition. The annealing treatment also improved the soft magnetic properties of (Fe$_{1-x}$ Mo$_{x}$)$_{80}$ B$_{12}$ Si$_{8}$ amorphous alloys. It could be thought that these improvements were ascribed to the relaxation of internal stress.nal stress.ess.

The properties of sintered Ag-SnO$_2$contacts which contain the second oxide were investigated with hardeness, workability, electrical conductivity and are erosion. Ag-SnO$_2$contacts containing ZnO or Bi$_2$O$_3$have most excellent workability and arc erosion endurance.

All-polycrystalline Cd$_1$-xZnxS/CdTe solar cells have been fabricated by coating CdTe slurries with 4.5 wt% of CdCl$_2$on the sintered Cd$_1$-xZnxS films and by sintering CdTe layer at 6$25^{\circ}C$ for lh in nitrogen atmosphere. Solar efficiency of the sintered Cd$_1$-xZnxS/CdTe solar cells increases as the Zn content increases up to x=0.06 and then decreases with further increase in the Zn content. A solar efficiency of 12.5% under a solar intensity of 76mW/$\textrm{cm}^2$ was observed in a Cd 0.94 Zn0.06S/CdTe solar cell. By optimizing the amount of CdCl$_2$in the slurry and sintering conditions, it is possible to produce Cd$_1$-xZnxS/CdTe solar cells with efficiency higher than 12%.

The cell parameters of the sintered CdS/CdTe solar cells in which te CuCl$_2$was added in the carbon paste after the sintering of the CdS/CdTe composites an were annealed at 35$0^{\circ}C$ for 10 min in nitrogen are investigated. Voc and FF do not change significantly as the CuCl$_2$increasing up to 500 ppm, Jsc increases with futher increase in copper. The hole concentration, determined by C-V measurement, increases to $1.5\times$10$^{16}$ ㎤ as the copper increased to 25 ppm and then stays at about the same value with further increase in copper.

Piezoelectric BaTiO$_3$-polymer composite were investigated for dielectric and piezoelectric properties with the barium titanate active particle size. Under the condition of the same density and ceramic volume ratio of composite, the dielectric and piezoelectric constant of composite are increasing as the ceramic particle size in composite are increasing. The surface layer model was quoted to explain these phenomena in our system and experimentally confirmed. The connectivity parameter of modified cube model of composite was calculated from the dielectric constant variation as their particle size. The connectivity parameter X and Y were 77.8% and 98.9% respectively. It means that the barium titanate particle distribution in composite nearly approach to the parallel mode. It was experimentally confirmed that the surface layer has low dielectric and nonferroelectric properties. Dielectric constant and thickness of surface layer were calculated from the equivalent circuit of composite.

After reviewing previous work done on two piezoelectric thin films(PZT, ZnO), ZnO thin piezofim of 1-3UM is fabricated by sputtering on the different substrates(i. e., P+Si/N-Si, SiO2/P+Si/ N-Si, Al/SiO2/ P+Si/ N+Si). The result shows that ZnO piezofilm on the Al has the best c-axis orientation. One of applications for the ZnO piezofilm as an microvalve to control liquid flow is introduced, and which can be controlled electrically and remotely.

(1-x-y)Pb($Zn_{1/3}Nb_{2/3})O_3-Ba(Zn_{1/3}Nb_{2/3})O_3-PbTiO_3(0.12{\leq}x{\leq}0.21, 0.24{\leq}y{\leq}0.33$) ternary compound ceramics were fabricated by the mixed oxide method. The sintering temperature and time were 1050 [$^{\circ}C$], 2[hr]. Morphotropic phase boundary region was chosen for the composition. 0.55 PZN-0.21 BZN-0.24 PT specimen had the highest value of relative dielectric constants, 5353. The curie temperature of specimens were increased linearly with PT content. Near the morphotropic phase boundary, electro-mechanical coupoling factor and mechanical quality factor of the specimens had the highest values.

x Pb($Sb_{1/2}Sn_{1/2}O_3-PbTiO_3-PbZrO_30.05{\leq}x{\leq}0.25$) ternary compound ceramics were fabricated by the mixed oxide method. The sintering temperature and time were 1200-1270[$^{\circ}C$], 2 hour, respectively. Increasing the PSS contents, the transition temperatures were decreased. The relative dielectric constant and Curie temperature of the 0.25 PSS-0.25 PT-0.5 PZ specimens were 450, 220[$^{\circ}C$]. The Pyroelectric coefficient of the 0.25PSS-0.25PT-0.50 PZ specimen was $5.20{\times}10^4$[C$\textrm{cm}^2$K].

The aim of the study is to develope the processing technique of PZT-Polymer piezoelectric composite materials for ultrasonic transducer application such as biomedical probe and hydrophone. Piezoelectric composite of PZT and polymer with 1-3 connectivity patterns have been fabricated by dicing-filling method and extrusion forming method. In this study processing forming method. In the study processing steps by extrusion forming method in the preperation of PZT/polymer piezoelectric composites are described. The PZT powder used in the study is commercial powder which is prepared by mixing PbO, TiO$_2$ and ZrO$_2$. The binder, water and plasticizer are mixed with the PZT powder to form a slip. It is necessary to adjust the viescosity of slip according on the PZT rod diameters to be extruded. The electromechanical properties of the piezoelectric composites are characterized in terms of the thickness resonance mode. The pulse response characteristics by the ultrasonic transducer analyzer and osciloscope are evaluated.

Lead titanate thin films with a perovskite structure were successfully structure were successfully fabricated on titanium substrate by Chemical Vapour Deposition(CVD). Analyses of Auger Electron Spectroscopy(AES) and X-ray Photoelectron Spectroscopy (XPS) have been performed in order to find a chemical composition of lead titanate films. The analysis of chemical composition by AES and XPS was investigated for variations of deposition temperature and Ti(C$_2$H$_{5}$O)$_4$ fractions. The chemical composition of PbTiO$_3$by XPS analysis was almost constant regardless of deposition parameters and the comparison of chemical composition by AES and XPS was performed.d.

We fabricated primary and secondary seed grains. Primary seed grains having larger grain size were obtained under the conditions that were 2.0m/o BaCO$_3$ and 10 hours sintering. The amount of primary seed grain to yield the largest secondary seed grains were choosed as 3 w/o and we fabricated the low voltage varistors which were joined the low voltage-oriented ZnO varistor system made by conventional method with the secondary seed grains. As a result, ZnO varistor showed appoximately 10V/mm of nonlinear resistance and 15-22 of nonlinear exponent.

NTC thermistor was prepared by adding TiO$_2$and MnO$_2$on Fe$_2$O$_3$and the effects of additions were investigated. And the effects of compating pressure, sintering temperature, and sintering time were also experimented. Fe$_2$O$_3$is insulator in stoichiometric state and will be semiconductor by introducing Ti$^{+4}$, Sn$^{+4}$. These semiconducting material will show large negative temperature coeffecients and can be used as NTC thermistor.tor.

Thermistor is the semiconducting material whose electrical resistance is varied with its self heating. In this paper, the improvement of resistance-temperature characteristics of NTC thermistor devices based on NiO was experimented. The specimens were prepared by mixing NiO and Mn$_2$O$_3$(1:1 mole %) and by addition of CuO(1 wt %, 2 wt %, 4 wt %). The specimens were compacted at the pressure of 1000 kg/$\textrm{cm}^2$ and sintered for 1 hour in air ambient at 120$0^{\circ}C$. Reducing CuO additions not only resistance-temperature characteristics, but also increased room temperature resistance.

Thermal Electet of the Zinc Oxide varistor has been studied in the temperature range of -130~200[$^{\circ}C$] and the electric field of 6[kV/m]. It appears that there are four peaks of thermally stimulated current; $\alpha$, $\beta$, ${\gamma}$ and $\delta$ spectra appearing at the temperature range of 160, 130, 20 and -30[$^{\circ}C$], respectively. It seems that the origin of $\alpha$, $\beta$, ${\gamma}$ and $\delta$ peaks are associated with the depolarization of donor ions in the depletion layer, the detrapping of trapped electron in the surface, the detrapping of trapped electron in the donor level and the detrapping of trapped electron between grain and intergranular, respectively.

The effects of pyrochlore phase and micostructure on the dielectric properties. such as dielectric constant, dissipation factor, diffusensess coefficient and dielectric hysteresis characteristics, of Lead magnesium niobate(PMN) ceramics have been studied as a function of the amount of excess MgO. The pyrochlore phase in PMN was completely eliminated with the addition of 5 m/o excess MgO. Also, the dielectric constant and remanent polarization increased with increase in grain size, density and then decreased with grain growth inhibitation for further addition of excess MgO. The diffuseness coefficient showed a tendency nearly reverse to that for the dielectric constant and remanent polarization change.

Based on the ferroelectric microstructural residual stress model, the relation between grain size and residual elastic energy was proposed. It was found that the residual elastic energy increased with decreasing grain size by modeling and DSC results. This residual elastic energy change with grain size which induce the phase transituion mode change was the cause of a diffuse phase transition in small grain size.

This paper reports the optical characteristics of TeS$_{5}$ Ge$_{5}$ thin film. In phase diagram, TeS$_{5}$ Ge$_{5}$ has the eutetic point with the loweat melting point. Therfore, TeS$_{5}$ Ge$_{5}$ thin film will be melted by Diode Laser with low energy. TeS$_{5}$ Ge$_{5}$ thin films start to change the phase from amorphous to crystalline near 10$0^{\circ}C$, but perfectly change the phase at 28$0^{\circ}C$. As-deposit TeS$_{5}$ Ge$_{5}$ thin film start to change the phase to crystalline in enviroment og 66$^{\circ}C$ 80%RH.circ}C$ 80%RH.

An infrasonic wide band transducer fabricated by polytetrafluoroethylene(PTFE)is studied experimentally. The sensitivity of the transducer depends largely on the surface charge of the Electret and is typically between-50 and -62[dBV] for a sound-pressure level of 1[ubar]. The sensitivity of the transducer does not decay over periods of the order of years at room temperature. The frequency response is within 1.5[dB] from 1 to 6,000[Hz] and within 12[dB] from 0.05[Hz] to 1[Hz] respectively. The resonance frequency of the element is 510 [Hz]. We conjectures that the element is applicable to accustics, communication system, seismological observation and other similar filed.