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Vacuum circuit breakers have an issue of instability arc current and chopping phenomena when the current is cut off from the circuit. To clarify the effect of the instability low-current vacuum arc for circuit breaker development, the instability mechanism of low-current vacuum arc for various parameters was proposed to verify consequent affecting circuit breaker capacity in this paper. This paper used the cathode spot model neglect the transition region between the collisionless sheath and collisional plasma region. The eight equations were used for solving the dependent variable of plasma parameters for both silver and copper electrode materials. The low ionization was supposed in the cathode spot model. The results showed that the changes in the work function and ion current fraction at ambient temperature did not have the main influence on the arc stability limit current both in the silver electrode and copper electrode. On the contrary, the changes in the heat conductivity at ambient temperature affecting the arc stability limit current significantly both in the silver and copper electrodes. Furthermore, the results were found out that the cathode spot can be confirmed unstable current phenomena when the current below 19 A for copper cathode and below 19.4 A for the silver cathode. These phenomena can be explained that the reversed electrons flow from the plasma side to sheath region affecting the electric field at cathode spot become negative zone; thus, the starting noise on the current trace appears before chopping current.

Indium doped tin oxide (ITO) nanostructured films were prepared by the electron-beam evaporation with the oblique-angle deposition (OAD) technique. The influence of the film thickness of the ITO nanostructures on the crystal structures, the physical morphologies, the optical properties, and the electrical attributes was investigated by grazing-incident X-ray diffraction (GIXRD), field-emission scanning electron microscopy (FE-SEM), UV-Vis spectrophotometry, four-point probe measurements, the respectively. The GIXRD analyses indicated that the ITO nanostructured films were mostly polycrystalline with the cubic bixbite structure. The FE-SEM micrographs clearly showed that the increased film thickness greatly affected the morphologies of the ITO nanostructures. The optical transmission spectra at the different angles of incidence clearly demonstrated the optimized results for the highest transmission in the visible region. The electrical resistivity of the ITO nanostructures was gradually decreased with the increased ITO thickness. Finally, the most optimized solar transmission with small light scattering and sheet resistance were discussed based on the anti-reflection performance of the ITO nanostructured films towards the solar cell applications.

In this study, we investigated the effects on the film thickness of the vertically aligned indium-doped tin oxide nanorods (ITO NRs). The ITO nanorods of deposited time at 180 to 780 sec were deposited on the silicon wafers and ITO-coated glass substrate by the ion-assisted electron-beam evaporation with the glancing-angle deposition technique. The physical microstructures and optical properties of the prepared samples have been investigated by grazing-incident X-ray diffraction (GIXRD), field-emission scanning electron microscopy (FE-SEM), and spectrophotometry. From the results, the ITO nanorods indicated the bixbite structures. The FE-SEM micrographs showed the changes of the physical morphologies based on the increased film thickness. The angle-dependent transmission as measured from -80° to 80° incident angles demonstrated the increased optical transmission from the vertically aligned ITO nanorods, compared to that of the ITO-coated glass. The enhancement of the optical transmission was related to the anti-reflection and light-scattering properties of the ITO nanorods, and offered a great potential for solar cell applications.

This paper describes the design charging and discharging supercapacitors of LED lamps for emergency lighting rated 10-W, 12-V. Designing two modules of supercapacitors used, each 33.33-F, 15-V. By SC1 and SC2 are charged by simultaneously until fully. When the power outage SC1 will discharging the led lamps until the voltage reduced to 5-V. Then SC2 will discharging charge to the led lamp until the voltage reduced to 5-V. Causing both SC1 and SC2 to not be able to discharge energy. When the electrical system enters normal conditions, both SC1 and SC2 will be recharged again. The results showed that was when supercapacitors charged by plugging in to the 220-Vac electrical system. The supercapacitors were fully charged at 15.4-V in 10 minutes. After that, the relay control circuit would disconnected the charging process. In case of power outage, the supercapacitors discharging to the LED lamps. It can give luminance for 28.34 minutes. The luminous efficacy of emergency lighting was 20.20 lumens per watt.

Solar cell converts sunlight into electricity with no moving parts and environmental friendly. Although silicon based solar cell is currently more efficient, the dye-sensitized solar cell is considerably cheaper to manufacture because of its low cost materials and simplicity process of fabrication. In this paper, the development of plasma formed equipment for thin film material on flexible solar cell using low-pressure high frequency Plasma Chemical Vapor Deposition method on the surface of Polyethylene naphthalate (PEN) with the mixture of Ar gas and N2gas is presented. The results indicate that using this method can be possible for surface modification.

Even though silicon based solar cell currently has more efficient, the dye sensitized solar cell is considerably cheaper for manufacturing because of its low cost materials and simplicity process of fabrication. In this paper, the development of plasma formed equipments for thin film material on flexible solar cell using low-pressure high-frequency plasma chemical vapor deposition method on the surface of Si wafer with the mixture of Ar gas and O 2 gas is presented. The results indicate that using this method can be possible for surface modification.

In recent years, a flexible type of solar cell that can maintain various shape changes and that is applicable to virtually all products has attracted global attention. In the present research, we describe equipment for the production of thin-film material for flexible type solar cells that uses a high-frequency plasma chemical vapor deposition (CVD) method. This equipment is now at the development stage, and in order to clarify the cardinal trait of the plasma, we performed a plasma treatment on the surface of a Si wafer. Using X-ray photoelectron spectroscopy and contact angle meter measurements, we identified one index that clarifies the simple cardinal trait of plasma CVD.

In order to clarify the instability phenomena of a low current vacuum arc, characterized by noise on the current trace prior to the actual current chopping, an analysis of silver cathode spot has been made. For the analysis, cathode spot region is recognized as the collisionless space charge sheath connected with singly ionized collisional plasmas.It is proposed that a current level below that no real solution exists is unstable current and this current corresponds to the point at which a vacuum arc turns into unstable. It is found that there is no real solution when the current is below 19.4A. The physical explanation is considered that the electrons returning to the sheath region from the plasma one dominate over positive ions and, consequently, the electric field at the cathode surface is F02

This study described the physical mechanism of the thermal conductivity effect on the instability phenomena using the cathode spot model. An analysis of stable arc current is performed by changing thermal conductivity of copper by compound material. It was found that the minimum stability arc is inversely proportion to the thermal conductivity. The thermal conductivity is reduced to increase stable arc current with reducing reversed electron from plasma region. The thermal conductivity is reduced with increasing the stable arc current region. Consequently, the cathode temperature is decreased. It can be concluded that the electron current is reduced by lower cathode temperature. This analysis results revealed that percent weight had inverse variation with thermal conductivity and flow heating alloy. The research results revealed that degree of ionization of copper had inverse variation with arc current. The debye length of copper had direct variation with arc current.

The purpose of this research was to analyses and compare the instability of a contact surface between copper and nickel as an alloy cathode in vacuum, the different ratio of copper and nickel were conducted at 1%, 4% and 6% by using the cathode spot model which is recognized as the collisionless space charge sheath connected with singly ionized collisional plasma. It was found that the minimum stable arc current is highly dependent on the thermal conductivity of the cathode material due to amount of percent nickel. The chopping current is proportional to the level of minimum stable arc current. As results, the smaller recovery voltage which is induced by chopping current. This is a very important result for the development of cathode materials for low - surge vacuum interrupters. The results obtained by this study clearly demonstrate the physical mechanism of current instability occurrence, the level of chopping current and the recovery voltage in power system.

To utilize waste glass fiber-reinforced plastic (GFRP) and to reduce environmental pollution in rivers and lakes, we developed a filtering material that can clean contaminated water. The high strength and porous nature of glass fiber-reinforced ceramic made by mixing clay and crushed waste GFRP before firing was exploited to do so. Various specimens with different pore size distributions were made by changing the mixing ratio of clay and crushed GFRP, the GFRP particle size, and the mixture firing temperature. Bending strength and permeability tests indicated that several types of ceramics with good permeabilities and adequate bending strengths could be produced, which enables their use as filtration materials for turbid water. Filtration tests on simulated turbid water clarified the relationship between the pore size distribution and the filtering ability of the ceramic for turbid water. Filtration tests on river water verified their practical suitability as ceramic filtration materials. It is proposed that ceramics made from clay and GFRP could be used as filtering materials for turbid water.