http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
이재훈(Jaehun Lee),정경진(Kyoung Jin Jung),이길태(Kil Tae Lee),강인모(Inmo Kang) 한국전산유체공학회 2009 한국전산유체공학회 학술대회논문집 Vol.2009 No.11
In this study, two and three dimensional low Reynolds number flows are compared. For the two dimensional flow, an airfoil was considered and for the three dimensional low wing and full-body aircraft were considered. Because a flight condition of the aircraft is in a low Reynolds number flow, itl requires reflecting flow transition. In the two dimensional analysis, transition is predicted using en method. In the three dimensional flow, the effect of transition is included using k-w SST turbulence models.
이원중(Won Joong Lee),송지운(Jiwoon Song),정경진(Kyoung-Jin Jung),조형희(Hyung Hee Cho) 한국추진공학회 2012 한국추진공학회 학술대회논문집 Vol.2012 No.11
본 연구의 목적은 사각공동 내부와 그 주변에서 발생하는 유동특성들을 이해하고, 플라즈마 액츄에이터를 이용해 이를 제어하는 방법을 실험적으로 조사하는 것이다. 사각공동의 상류지점에 서로 다른 방향으로 플라즈마 액츄에이터를 설치하여 각각의 액츄에이터 작동에 따른 유동장의 변화를 입자영상 유속계(PIV)를 통해 측정하였다. 사각공동의 종횡비와 플라즈마 액츄에이터의 유동 가속 방향에 따라 각기 다른 현상이 나타났으며, 이 결과로부터 플라즈마 액츄에이터를 이용한 사각공동 주변의 유동제어가 가능함을 확인하였다. The object of this study is understanding flow characteristics on rectangular cavity and probe the flow controlling method which using dielectric barrier discharge plasma(DBD plasma) actuator. Plasma actuators are set up in front of rectangular cavity at different directions. Measure the changes of flow field after operate each plasma actuators by utilizing particle image velocimetry(PIV). Aspect ratio of rectangular cavity and direction of flow acceleration make different phenomena and according to these results, flow controlling method by DBD plasma is verified.
초내식성 스테인리스강 선재와 브라켓의 내식성 및 금속 이온 용출 특성
오근택,정경진,황충주,박용수,김경남 大韓齒科器材學會 2001 대한치과재료학회지 Vol.28 No.4
Metallic orthodontic appliances are known to release metal ions in an oral cavity. It is not advisable that toxic corrosion products derived from the appliances is absorbed into the body. Metal ions release from orthodontic appliances is known to have large effects on the result of orthodontic treatment and systemic health. Metal bracket and wire were made of super stainless steel(S32050) with high corrosion resistance. The corrosion resistance and ion release property of S32050 and conventionally used appliances were examined. Four types of wire were ligated in either super stainless steel(SB) or Tomy bracket(TB) with O-ring, and then each group was immersed in an artificial saliva at 37℃ for 12 weeks. Amount of released metal ions was measured with immersion time by graphite furnace atomic absorption spectroscopy and surface morphology was investigated. S32050 showed the low passive current density of about 1 μA/㎠ and the stable passive region to a high potential in artificial saliva. S32050 appliances did hardly release nickel ions in artificial saliva. S32050 wire(SRW) and NiTi wire(NW) didn't show significant difference of Ni ion release with immersion time, meanwhile, Remanium wire(RW) showed significant difference in 12 weeks. Ni ion releasce from the brackets didn't show any significant difference with immersion time and between SB and TB. Amounts of Ni ion released from TB-SRW showed significant difference in 12 weeks, those from TB-RW showed significant difference from 4 weeks later and highest release among all groupsin12weeks. TB-NW released little Ni ion for all immersion time and showed significant difference from 4 weeks later, TB-TW(TMA wire) showed significant difference in 12 weks. SB-SRW didn't show any significant difference and SB-RW signigicant difference in 12 weeks,but lower compared with TB group. SB-NW and SB-TW didn't show any significant difference. Corrosion products didn't be observed in mostly groups during the immersion time, except that in TB-RW, they were observed on the bracket surface between O-ring and wire from 8 weeks later. Super stainless steel wire had good corrosion resistance compared with stainless steel wire, and it is believed that it can be used as orthodontic material for bracket and wire.