http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Dae-Joon You,Seok-Myeong Jang,Jeong-Phil Lee,Tae-Hyun Sung IEEE 2008 IEEE transactions on magnetics Vol.44 No.11
<P>In our high-power flywheel energy storage system, the heavy and large flywheel is rotated by the electromagnetic torque of a permanent-magnet (PM) synchronous motor (PMSM) and, in case of a breakdown of electric current, this motor used as a generator supplies electric energy to the various electric utilities using mechanical rotation energy of the flywheel. Thus, the dynamic performance of the flywheel is related to the electromagnetic torque for the motoring and generating power of the PMSM/G. Moreover, in the idling mode without generating loads, speed reduction of the flywheel is mainly caused by drag torque generated in the slotless iron-cored stator of this PM machine. In this paper, the operating torque, defined as the electromagnetic torque and drag toque, is estimated from the magnetic-field analysis by the PM rotor with diametrical magnetization. Also, the dynamic performance of the flywheel, according to the driving mode, is simulated from dynamic modeling of the PMSM/G with the operating torque and verified by the experiment.</P>
신재생 에너지 적용을 위한 고효율 영구자석 동기 전동/발전기의 해석 및 설계
유대준(Dae-Joon You),김일중(Il-Jung Kim) 대한전기학회 2011 전기학회논문지 Vol.60 No.5
In renewable energy system such as flywheel energy storage system, wind power and solar power, the motor/generator is the important key for offering the electric energy to the electric loads. For example, the heavy and large flywheel is rotated by electromagnetic torque of pemanent magnet synchronous motor (PMSM) and, in case of a breakdown of electric current, the PMSM used as generator supplies electric energy for the various electric utilities using mechanical rotation energy of the flywheel. Thus, design of a motor/generator should be performed in effort to reduce cogging torque and electromagnetic loss for high efficiency. In our paper, a slotless permanent magnet synchronous motor/generator (SPMSM/G) with output power 15kW at the rotor speed 18000rpm is designed from electromagnetic analysis and dynamic performance analysis. In analytical approach, design parameters such as back electro-motive force (back EMF), inductance and electromagnetic torque are derived from analytical method which is one of the electromagnetic analysis method. And using the design parameters, this paper deal with system design considering the driving characteristics and electric load in required power. Finally, the analytical results are verified by the experiment and finite element method (FEM).
C.V.D. 방법에 의한 Cd_0.78Zn_0.22 S박막 성장과 광전기적 특성연구
유상하,이상렬,홍광준,서상석,김혜숙,전승룡,윤은희,문종대 조선대학교 기초과학연구소 1993 自然科學硏究 Vol.16 No.1
We had grown Cd_0.78Zn_0.22S polycrystal thin films on slide substrate using chemical vapour deposition(CVD) method. We measured X-ray diffraction patterns in order to study Cd_0.78Zn_0.22S polycrystal structure. We studied its band gap using transmission curves and photocurrent and also analyzed photoluminescence using configurational coordinate model. We measured Hall effect·on this sample by Van der Pauw method and studied on carrier density and mobility depending on temperature.
You, Mi-Hyeon,Kim, Wang-Joon,Shim, Wooyoung,Lee, Sang-Rim,Lee, Gwang,Choi, Sangdun,Kim, Dae-Yong,Kim, Yong Man,Kim, Hyunsoo,Han, Sang-Uk Blackwell Publishing Asia 2009 Journal of gastroenterology and hepatology Vol.24 No.8
<P>Abstract</P><P>Background and Aim: </P><P>Stem cell transplantation offers potential gene therapy for brain tumors. However, this approach has received little attention as a treatment for gastrointestinal tumors. In the present study, we explored the possibility of human bone marrow-derived mesenchymal stem cells (hMSC) producing cytosine deaminase (CD), followed by systemic 5-fluorocytosine (5-FC) administration, showing an antitumor effect on a mouse gastric cancer xenograft.</P><P>Methods: </P><P>We first explored the ability of hMSC, coated with fluorescent dye, to migrate to human gastric cancer MKN45 cells <I>in vitro</I> and <I>in vivo</I>. We then used hMSC in which a gene expressed the prodrug-activating enzyme CD, which can convert the prodrug 5-FC into the cytotoxic agent 5-fluorouracil (5-FU), and further investigated the potential of these cells to deliver the CD gene and to reduce tumor growth in nude mice. The migratory capacity of hMSC was confirmed by an <I>in vitro</I> migration assay, as well as in an <I>in vivo</I> model of nude mice bearing subcutaneous tumors of MKN45 cells when hMSC were injected.</P><P>Results: </P><P>The migration ability of hMSC towards MKN45 cells was confirmed by migration assay. Effective conversion of 5-FC to 5-FU by hMSC transfected with the CD gene (CD-hMSC) showed therapeutic anticancer potential in a MKN45 cell co-culture system, as confirmed by thin layer chromatography. Nude mice bearing MKN45 tumors were intravenously injected with CD-hMSC, followed by systemic 5-FC treatment (500 mg/kg/day) for 7 days. Tumor volumes and weights of mice injected with CD-hMSC decreased significantly after treatment with 5-FC. However, the 5-FC-treated group without CD-hMSC injection showed neither a decrease in tumor volume nor bodyweight loss.</P><P>Conclusion: </P><P>The CD-hMSC system showed anticancer therapeutic potential, and minimized the side-effects of 5-FU.</P>
n-CdS_(0.46)Se_(0.54)/p-Cu_92-x)S_(0.46)Se_(0.54) 이종접합 태양전지의 제작과 그 특성에 관한 연구
유상하,최승평,이상열,홍광준,서상석,김혜숙,전승룡,윤은희,문종대,신영진,정태수,신현길,김택성,유기수 全北大學校 基礎科學硏究所 1994 基礎科學 Vol.16 No.-
승화방법에 의해 CdS_0.46Se_0.54 단결정을 성장하여 결정구조를 조사하고, Van der Pauw 방법으로 Hall effect를 측정하여 carrier density의 온도 의존성과 mobility의 온도 의존성을 조사하였다. 성장된 CdS_0.46Se_0.54 단결정을 치환반응하여 n-CdS_0.46Se_0.54/p-Cu_2-xS_0.46Se_0.54 이종접합 태양전지를 제작하였다. Spectral response, 전류-전압특성 및 전력변환 효율을 조사하여 그 결과로부터 개방전압은 0.48V, 단락 전류 밀도는 21mA/㎠, fill factor와 전력변환효율은 각각 0.75와 9.5%를 얻었다. CdS_0.46Se_0.54 single crystal was grown by a sublimation method. The crystal structure and the temperature dependence of carrier density and mobility of CdS_0.46Se_0.54 single crystal were studied. Heterojunction solar cells on n-CdS_0.46Se_0.54/p-Cu_2-xS_0.46Se_0.54 were fabricated by the substitution reaction. The spectral response, the J-U characteristics and the conversion efficiency of the n-CdS_0.46Se_0.54/p-Cu_2-xS_0.46Se_0.54 heterojunction solar cells were studied. The open-cricuit voltage, short-circuit density, fill factor and conversion efficiency of n-CdS_0.46Se_0.54/p-Cu_2-xS_0.46Se_0.54 heterojunction solar cells under 80mW/㎠ illumination were found to be 0.48V, 21mA/㎠, 0.75 and 9.5%, respectively.