Silicon carbide (SiC) is a promising material for power device applications due to its wide band gap(3.26 eV for 4H-SiC), high critical electric field and excellent thermal conductivity. The Schottky barrier diodeis the representative high-power device that is currently available commercially. A field plate edge-terminated4H-SiC was fabricated using a lift-off process for opening the Schottky contacts. In this case, Ni/Ti dual-metalcontacts were unintentionally formed at the edge of the Schottky contacts and resulted in the degradation ofthe electrical properties of the diodes. The breakdown voltage and Schottky barrier height (SBH, ΦB) was 107V and 0.67eV, respectively. To form homogeneous single-metal Ni/4H-SiC Schottky contacts, a deposition andetching method was employed, and the electrical properties of the diodes were improved. The modified SBDsshowed enhanced electrical properties, as witnessed by a breakdown voltage of 635V, a Schottky barrier heightof ΦB=1.48eV, an ideality factor of n=1.04 (close to one), a forward voltage drop of VF=1.6V, a specific onresistance of Ron=2.1mΩ-cm2 and a power loss of PL=79.6Wcm-2.

최근 지진의 발생 빈도가 잦아지면서 고강도 내진 철근에 대한 관심이 급증하였다. 그러나 현재 콘크리트구조 학회기준 (2017)에서는 철근콘크리트 부재의 전단철근의 항복강도를 500MPa로 제한하고 있다. 이 논문에서는 이러한 설계기준항복강도 제한을 확장하기 위해 고강도 내진 철근을 사용한 철근콘크리트 보의 실험을 수행하였다. 실험에는 항복강도가 400MPa, 500MPa, 700MPa인 전단철근이 사용되었으며 전단철근의 배근간격을 변수로 하여 철근비에 따른 철근콘크리트 보의 전단거동을 비교하였다. 실험결과 철근량과 철근의 항복강도가 증가할수록 전단강도비가 감소하는 경향이 나타났다.

In this study, the torsional strength of reinforced concrete hollow beams is predicted by nonlinear finite element analysis. A nonlinear finite element analysis program, ATENA, was used for the analysis. A total of six reinforced concrete beams were used and the analysis was performed under the same conditions as the actual test.

Anaerobic/aerobic reactor system was used to treat a synthetic wastewater with glucose as carbon sources(0.38˜2.29 kg COD/m3.day) and Acid Red 14(1.05˜24.00 g Acid Red 14/m3.day, color degree of 570˜1710). COD removal efficiency by the anaerobic stage in operation period were above 90 % organic loading rate of 0.38˜2.29 kg COD/m3.day(except, adaptation period) and the removal efficiency of the whole system were above 96 %. The decolorization of the Acid Red 14 was through the alteration of the dye structure(or cleavage of the Azo bond) during the anaerobic treatment. In the A/A system, the anaerobic stage played an essential role in removing both color and COD. In addition it also improves biodegradability of dye for further aerobic treatment. After operation, average MLSS concentration of anaerobic sludge reactor, anaerobic fixed-bed reactor and aerobic fixed-bed reactor were 17100mg/L, 20000mg/L, and 10000mg/L, respectively.