http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Sm을 첨가한 BaTiO<sub>3</sub>계의 재산화 온도 및 시간에 따른 PTC 특성 변화
정용근,최성철,Chung, Yong-Keun,Choi, Sung-Churl 한국세라믹학회 2009 한국세라믹학회지 Vol.46 No.3
We investigated the effects of the re-oxidation temperature and time on the positive temperature coefficient (PTC) of resistivity characteristics of Sm-doped $BaTiO_3$ sintered at $1200{\sim}1260^{\circ}C$ for 2 h in a reducing atmosphere (3% $H_2/N_2$), followed by re-oxidization processes in air, in which re-oxidization temperature and time were $600{\sim}1000^{\circ}C$ and $1{\sim}10$h, respectively. The result reveals that Smdoped (Ba,Ca)$TiO_3$ ceramics fired in a reducing atmosphere exhibit low PTC characteristics, whereas the sample re-oxidized at $800^{\circ}C$ for 1 h in air exhibit pronounced PTC characteristics. The room-temperature resistivity and jumping characteristics of resistivity (${\rho}_{max}/{\rho}25^{\circ}C$) decrease with Sm contents. The PTC characteristics with reoxidization time at $800^{\circ}C$ have improved about $2{\sim}3$ orders of magnitude whereas differed according to the sintering temperature. The 0.7 at% Sm-doped (Ba,Ca)$TiO_3$ samples reveal the best PTC characteristics in the present range of formula and processes.
Voriconazole로 치료한 Scedosporium apiospermum 에 의한 피부감염증 1예
정용근,배인규,임민희,김재희,강민경,김선주,허상택 대한의진균학회 2008 대한의진균학회지 Vol.13 No.4
Scedosporium(S.) apiospermum has been isolated from polluted water, soil, sewage and potted plants in a hospital with low virulence. The localized skin infection due to S. apiospermum is rare and usually results from traumatic implantation of contaminated material due to a penetrating injury. We report a case of skin infection due to S. apiospermum in a 78-year-old female. She had multiple nodules, pustules and exudative ulcerative lesions at the right forearm. Cultured isolation for definitive diagnosis showed typical S. apiospermum. Treatment was started with itraconazole effectively, but skin lesions were recurred after 4 months, and then cured with voriconazole with no recurrence. Scedosporium(S.) apiospermum has been isolated from polluted water, soil, sewage and potted plants in a hospital with low virulence. The localized skin infection due to S. apiospermum is rare and usually results from traumatic implantation of contaminated material due to a penetrating injury. We report a case of skin infection due to S. apiospermum in a 78-year-old female. She had multiple nodules, pustules and exudative ulcerative lesions at the right forearm. Cultured isolation for definitive diagnosis showed typical S. apiospermum. Treatment was started with itraconazole effectively, but skin lesions were recurred after 4 months, and then cured with voriconazole with no recurrence.
소성 조건에 따른 WO$_3$계 후막센서소자의 제조 및 응답특성
정용근,엄우식,이희수,최성철 한국마이크로전자및패키징학회 1999 마이크로전자 및 패키징학회지 Vol.6 No.2
가스 감지막의 미세구조와 비화학량론 구조의 변화에 따른 응답특성의 거동을 고찰하기 위하여 소성 조건을 변화시키면서 $WO_3$후막형 가스센서를 제조하였다. 소자는 감지물질인 $WO_3$분말과 유기 용제를 균일하게 혼합한 페이스트를 Au전극과 $RuO_2$발열체가 입혀진 알루미나 기판 위에 스크린 프린팅 방법으로 제조하였다. 소성 조건을 변화시키기 위하여 600-$800^{\circ}C$ 온도범위하에서 1시간 동안 열처리 하였고, Ar과 $O_2$가스의 비율을 변화시키면서 $700^{\circ}C$에서 1시간 재열처리하였다. 열처리 결과, 소성 온도 $700^{\circ}C$에서 제조된 $WO_3$가스센서 소자가 가스감도 210, 응답속도 2초로 가장 좋은 특성을 보였으며 Ar과 $O_2$가스의 비율이 40-50%의 소성 분위기에서 가스 감도가 가장 높게 나타났다. We have fabricated $WO_3$ thick film gas sensor under various firing conditions in order to study gas sensing properties in terms of the variation of microstructure and non-stoichiometric structure of gas sensing layer. $WO_3$ paste mixed homogeneously with organic vehicle was coated by screen printing method on alumina substrate composed of Au electrode and $RuO_2$heater on each side. To change filing condition, sensing materials were fared at 600-$800^{\circ}C$ for 1 hour and refired at $700^{\circ}C$ for 1 hour in the mixtures of $_Ar/O2$gas. In the result of heat-treatment, $WO_3$ gas sensor fared at $700^{\circ}C$ showed best gas sensing properties of 210 gas sensitivity and 2 second response time and the best firing environment was 40-50% of $Ar/O_2$gas.