The photoinduced hydrophilicity of TiO2/WO3 double layer films was fabricated by using a conventional rf-magnetron sputtering method. The photoinduced hydrophilic reaction of the TiO2 surface was enhanced by the presence of WO3 under the TiO2 layer by irradiation of a 10 W cylindrical fluorescent light bulb. However, when the TiO2 and WO3 layers were separated by an insulating layer, the surface did not appeared high hydrophilic,under the same light bulb. The enhanced photoinduced hydrophilic reaction can be explained by the charge transfer between TiO2 and WO3 layers. It was also demonstrated that visible light passing through the TiO2 layer could excite WO3. Thus, visible light can be used for the hydrophilic reaction in the present TiO2/WO3 system.

Inside the existing superconducting cables, the superconducting wire carries a loss-free current, and the cable former (the stranded copper wire) bypasses the fault current to prevent damage and loss of the superconducting cable when the fault current is applied. The fault-current-limiting-type superconducting cable proposed in this paper usually carries a steady current; but in a fault state, the cable generates self-resistance that makes the fault current lower than a certain width. That is, the superconducting cable that transmitted only a low voltage and a large capacity power repetitively limits the fault current, as does a superconducting current limiter. To complete this structure, it is essential to investigate the mutual resistance relationship between the superconducting wires after applying a fault current. Therefore, in this paper, one kinds of superconducting wires (a wire without a stabilization layer) were connected parallel 4 tapes, respectively; and after applying a fault current, the current, voltage, resistance and thermal stability of the HTS thin-film wires were examined.

When an abnormal condition occurs due to a fault current at a consumer location whereelectricity is supplied through high-Tc superconducting(HTS) cable, the HTS cable would be damaged ifthere is no appropriate method to protect it. The fault-current-limiting type HTS cable that is suggestedin this study has a structure of transport part and limit part. It conduct a zero impedance transportcurrent at ordinary operations and carry out a fault current limiting at extraordinary operations. To makea perfect this structure, it is essential to investigate electrical properties of transport part that comprisethe fault-current-limiting type HTS cable. In this paper, transport part that comprise HTS wire withcopper stabilization layer is examined the current transport properties and the stability evaluation.

When an abnormal condition occurs due to a fault current at a consumer location where electricity is supplied through a high-capacity and high-Tc superconducting(HTS) cable, the HTS cable would be damaged if there is no appropriate measure to protect it. Therefore, appropriate measures are needed to protect HTS cables. The fault-current-limiting HTS cable that was suggested in this study performs an ideal transport current function in normal operations and plays a role in limiting a fault current in abnormal operation (i.e., when a fault current is applied). It has a structure that facilitated its self-current-limiting ability through device change and reconfiguration in the existing HTS cable without extra switching equipment. To complete this structure, it is essential to investigate about the selection of the superconducting wire. Therefore, in this paper, HTS wire using two types of different stabilization layer is compared and examined the stability and current limiting properties under the existence of a fault current.

Abstract: To realize the high-Tc superconducting (HTS) DC cable system, it is important to study not only high current capacity and low loss of conductor hut also optimum electrical insulation at cryogenic temperature. A model I-ITS DC cable system consists of a HTS conductor, semi-conductor, cooling system and insulating materials. Polypropylene laminated paper (PPLP) has been widely adopted as insulating material for HTS machines. However, the fundamental insulation characteristics of PPLP for the development of HTS DC cable have not been revealed satisfactorily until now. In this paper, we will discuss mainly on the breakdown characteristics of 3 sheets PILP in liquid nitrogen (LN2). The characteristics of the diameter, location of butt-gap, distance between butt-gap length, pressure effect, polarity effect under DC and impulse voltage were studied. Also, the DC polarity reversal breakdown voltage of mini-model cable was measured in LN2 under 0.4 MPa.

In this paper, we designed and fabricated LED navigation lights which can replace the existing ones immediately and overcome disadvantages due to use of conventional lamps. To decide the best arrangement and position of a LED module, optical systems of existing navigation lights were analyzed and refracted routes of rays were simulated. The electrical and optical characteristics of the fabricated LED navigation lights were measured and analyzed with a goniophotometer. To calculate ranges of visibility, the vertical and horizontal luminous intensity distributions were evaluated in accordance with the COLREGs (convention on the international regulation for preventing collisions at Sea). From the results, the proposed LED navigation lights showed suitable characteristics for marine environment with the power consumption reduced by 90% and the maximum luminous intensity increased by 20% compared to the existing navigation lights.

Citations

• A study on the operation analysis of the power conditioning system with real HTS SMES coil
  A.R. Kim, H.Y. Jung, J.H. Kim, Mohd. Hasan Ali, M. Park, I.K. Yu, H.J. Kim, S.H. Kim, K.C. Seong
  Physica C: Superconductivity.2008; 468(15-20): 2104.     CrossRef