http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Mossbauer Study of Ti₁-x-yCoxFeyO₂
Eng Chan Kim,S. R. Lee,T. H. Kim,Y. S. Ryu,J. H. Cho,Y. G. Joh,D. H. Kim 한국자기학회 2006 韓國磁氣學會誌 Vol.16 No.1
Mossbauer spectra of Ti₁-x-yCoxFeyO₂ (0.01≤x, y≤0.05) prepared with (57)^Fe enriched iron have been taken at various temperatures ranging from 80 to 300 K. The Mossbauer spectrum of Ti0.94Co_(0.03)Fe_(0.03)O₂ consists of a ferromagnetic (six-Lorentzian), a paramagnetic phase (doublet) and armorphous phase over all temperature ranges. Isomer shifts indicate Fe³+ for the ferromagnetic phase and the paramagneic phase of Ti₁-x-yCoxFeyO₂ samples. It is noted that the magnetic hyperfine field of ferromagnetic phase had the value about 1.5 times as large as that of α-Fe. The XRD data for Ti₁-x-yCoxFeyO₂ showed mainly rutile phase with tetragonal structures without any segregation of Co and Fe into particulates within the instrumental resolution limit. The magnetic moment per (Co+Fe) atom in Ti_(0.94)Co_(0.03)Fe_(0.03)O₂ under the applied field of 1 T was estimated to be about 0.332μB which is ten times as large as that of Ti_(0.97)Co_(0.03)O₂, 0.024μB per Co atom, suggesting a high spin configuration of Co and Fe ions.
Han S. Uhm,Kyung H. Lee,Soon C. Cho,Sung Y. Jo,Chan U. Bang,Dong K. Lee 한국물리학회 2008 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.53 No.2
Surface treatments of Y2O3:Eu phosphors for improving the hydrophobic property were carried out using plasmas generated from a O-(Si(CH3)3)2 (HMDSO) in a low-pressure environment. The super-hydrophobic properties of the treated Y2O3:Eu phosphors were investigated. The samples treated by using the HMDSO/toluene glow plasma were analyzed by FTIR and OES and analyzed in terms of their contact angles (CAs). The effects of the HMDSO/toluene plasma treatments on the Y2O3:Eu phosphors were investigated in terms of the total surface free energy by using probe liquids to measure their contact angles (CAs). The total surface free energy of the Y2O3:Eu phosphors before and after a surface treatment with the HMDSO/toluene plasma, as estimated via the Owens-Wendt equation, was found to decrease from 82.2 mJ/m2 to 0.021 mJ/m2. This represents a significant improvement of the hydrophobicity of the Y2O3:Eu phosphors after the plasma treatment.
이우성,조현민,임욱,유찬세,이영신,강남기 한국마이크로전자및패키징학회 2000 추계 기술심포지움 논문집 Vol.2 No.1
Brazing characteristics of the LTCC(Low Temperature Co-fired Ceramics)/Kovar(Fe-Ni-Co alloy) was investigated. Kovar is one of the typical material for the lid of MCM and packages. In case of alumina package, Brazing process is done by higher temperature profile than 800 ℃ and Ag-Cu alloy. But, LTCC has sintering temperature near 850℃. So, it is difficult to use the same process as alumina brazing. The adhesion strength of the brazed part is affected by brazing alloy and metallization properties between conductor pattern and LTCC material. We investigated brazing characteristics of the LTCC/Kovar using various Urazing alloys(Ag-Cu, Au-Sn) and process conditions. And, we examined the influence of the glass contents in conductor on the brazing characteristics of the LTCC/Kovar.
임욱,강병환,유찬세,이영신,조현민,이우성,강남기 한국마이크로전자및패키징학회 2000 추계 기술심포지움 논문집 Vol.2 No.1
Non-aqueous tape casting of LTCC with PVB binder has been studied in a continuous tape casting machine. The aim of the study was to evaluate this type of system in the different Binder/Plasticizer and solid content compositions. Each four slurry compositions were used in the experiments with varied binder/plasticizer and solid content. All the slurries gave good quality tapes with smooth surfaces without blisters or pinholes. The highest mechanical properties was obtained for the B/P=3.0, powder content 70vo1% composition from 52 ㎛ green tapes, a tensile strength of 4.6 MPa and a linear extension of 29.5%.
Assessment of Soil Compaction Related to the Bulk Density with Land use Types on Arable Land
Cho, Hee-Rae,Jung, Kang-Ho,Zhang, Yong-Seon,Han, Kyung-Hwa,Roh, Ahn-Sung,Cho, Kwang-Rae,Lim, Soo-Jeong,Choi, Seung-Chul,Lee, Jin-Il,Yun, Yeo-Uk,Ahn, Byoung-Gu,Kim, Byeong-Ho,Park, Jun-Hong,Kim, Chan-Y 한국토양비료학회 2013 한국토양비료학회지 Vol.46 No.5
Soil compaction is affected by soil texture, organic matter (OM), strength (ST) and soil moisture, which is difficult to understand the degree and effects of related factors. The purpose of the study is to assess the impact of them on the compaction with bulk density (BD). The analysis was conducted with data collected from national-wide monitoring sites including 105 upland soils, 246 orchard soils, and 408 paddy soils between 2009 and 2012. The distributions of soil physical properties were measured. The correlation and multi linear regression analysis were performed between soil physical properties using SAS. The regression equation of BD(y) includes ST, gravitational water contents (GWC), and OM as variables commonly, having additional factors, clay content and sand content in paddy soil and upland soil for only subsoil (p<0.001). Our results show that the BD could be explained about 40~50% by various physical properties. The regression was mainly determined by ST in orchard and upland soil and by the GWC in paddy soil. To mitigate soil compaction, it is important to maintain the proper level of OM in upland soil and to consider the moisture condition with soil texture in paddy soil when making work plan. Furthermore, it would be recommended the management criteria classified by soil texture for the paddy soils.
A STATISTICAL STUDY OF STREAMER-ASSOCIATED CORONAL MASS EJECTIONS
Moon, Y.J.,Kim, Jin-Sug,Kim, Y.H.,Cho, K.S.,Bong, Su-Chan,Park, Y.D. The Korean Astronomical Society 2006 Journal of The Korean Astronomical Society Vol.39 No.4
We have made a comprehensive statistical study on the coronal mass ejections(CMEs) associated with helmet streamers. A total number of 3810 CMEs observed by SOHO/LASCO coronagraph from 1996 to 2000 have been visually inspected. By comparing their LASCO images and running difference images, we picked out streamer-associated CMEs, which are classified into two sub-groups: Class-A events whose morphological shape seen in the LASCO running difference image is quite similar to that of the pre-existing streamer, and Class-B events whose ejections occurred in a part of the streamer. The former type of CME may be caused by the destabilization of the helmet streamer and the latter type of CME may be related to the eruption of a filament underlying the helmet streamer or narrow CMEs such as streamer puffs. We have examined the distributions of CME speed and acceleration for both classes as well as the correlation between their speed and acceleration. The major results from these investigations are as follows. First, about a quarter of all CMEs are streamer-associated CMEs. Second, their mean speed is 413 km $s^{-1}$ for Class-A events and 371 km $s^{-1}$ for Class-B events. And the fraction of the streamer-associated CMEs decreases with speed. Third, the speed-acceleration diagrams show that there are no correlations between two quantities for both classes and the accelerations are nearly symmetric with respect to zero acceleration line. Fourth, their mean angular width are about $60^{\circ}$, which is similar to that of normal CMEs. Fifth, the fraction of streamer-associated CMEs during the solar minimum is a little larger than that during the solar maximum. Our results show that the kinematic characteristics of streamer-associated CMEs, especially Class-A events, are quite similar to those of quiescent filament-associated CMEs.
배열파력발전 플랫폼형상변화에 따른 운동응답특성에 관한 실험적 연구
박지용(J.Y. Park),남보우(B.W. Nam),신승호(S.H. Shin),박인보(I.B. Park),원영욱(Y.U. Won),오영재(Y.J. Oh),노찬(R. Chan),조세진(S.J. Cho) 한국해양환경·에너지학회 2018 한국해양환경공학회 학술대회논문집 Vol.2018 No.11
배열식 파력발전장치는 폭방향으로 긴 형상을 갖는 플랫폼에 다수의 로터를 배치하여 다양한 발전용량과 크기를 갖는 장치를 제작가능하다. 본 연구에서는 1MW 발전용량의 배열식파력 발전장치의 플랫폼형상에 대해 사이각 변화에 따른 운동응답특성의 변화를 실험적으로 분석하였다. 자유감쇠 실험을 통해 형상에 따른 고유주기를 검토하고, 150도, 120도, 90도로 사이각을 변화시키며, 정면과 측면의 입사파에서 주기와 파고에 따른 운동을 비교하였다. 이를 통해, 발전성능과 구조안전성의 측면에서 형상제어의 필요성을 확인하였으며, 추후 로터운동을 고려한 플랫폼 운동성능평가를 수행하려 한다. In the arrayed-buoy wave energy converter, a plurality of rotors is disposed on a platform having a long shape in the width direction, thereby making it possible to construct a device having various power generation capacities and sizes. In this study, the change of wave response according to the included angle was experimentally analyzed with respect to the 1 MW arrayed-buoy wave energy converter. The natural period of the platform was analyzed by free decay model test and the wave motions are measured and compared according to the included angle of 150°, 120° and 90° under the head sea and beam sea wave conditions. Through this study, the necessity of shape control in terms of power generation performance and structural safety was confirmed and we will perform platform motion performance evaluation considering rotor motion in the future.
Kim, S.J.,Kim, W.K.,Chan Cho, Y.,Park, S.,Jeong, I.K.,Yang, Y.S.,Kuroiwa, Y.,Moriyoshi, C.,Tanaka, H.,Takata, M.,Jeong, S.Y. Elsevier 2011 Current Applied Physics Vol.11 No.3
This study investigated the bonding nature and electrostatic potential of asymmetric Li ionic mobility in Li<SUB>2</SUB>B<SUB>4</SUB>O<SUB>7</SUB> crystals using the maximum entropy method (MEM) combined with Rietveld refinement and Ewald's technique. Compared with the interaction between oxygen and boron, Li<SUP>+</SUP> ions exhibited weak interactions with both oxygen and boron. Furthermore, electrostatic-potential-distribution analysis showed that Li<SUP>+</SUP> ions had a much weaker interaction with the matrix along the c-axis channel, suggesting that higher ionic conductivity occurred along the c-axis than along the a- and b-axes.