http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
오늘 본 자료
Yoon, Taeho,Kim, Daesoo,Park, Kern H.,Park, Hosang,Jurng, Sunhyung,Jang, Jihyun,Ryu, Ji Heon,Kim, Jae Jeong,Oh, Seung M. The Electrochemical Society 2014 Journal of the Electrochemical Society Vol.161 No.4
<P>The evolution of surface film on aspect of chemical composition and thickness is monitored on a nickel-doped manganese spinel positive electrode (LNMO, LiNi<SUB>0.5</SUB>Mn<SUB>1.5</SUB>O<SUB>4</SUB>) for lithium-ion batteries. In the first charging from 4.2 to 4.9 V (vs. Li/Li<SUP>+</SUP>), large amount of lithium fluoride (LiF) deposits at lower potentials (4.2 V) but it is removed when the electrode potential moves to the charging end (4.9 V). The phenomenon of LiF deposition at lower potentials and removal at higher potentials is repeated in the continuing cycles, but the overall LiF concentration becomes progressively lower for the surface films to be enriched by the carbon-containing organic species in the later cycles. Due to the highly resistive nature of LiF, the film resistance shows a strong correlation with the LiF concentration in the films. From the finding that LiF formation is the most significant at 4.2 V in every cycle, under which circumstances LNMO itself is fully lithiated to provide lithium source for LiF formation, hydrogen fluoride (HF) attack on the LNMO surface has been proposed to be the major route for LiF formation.</P>
Taeho Moon(문태호),Wonki Yoon(윤원기),Seung-Yoon Lee(이승윤),Kwang Sun Ji(지광선),Young-Joo Eo(어영주),Seh-Won Ahn(안세원),Heon-Min Lee(이헌민) 한국진공학회(ASCT) 2010 Applied Science and Convergence Technology Vol.19 No.2
ZnO:Al 박막은 산소 압력을 조절한 두 번의 증착 과정을 이용하여, DC 펄스 마그네트론 스퍼터링 방법에 의해 증착되었다. 시드막은 다양한 Ar/O₂ 압력비에서 증착되었으며, 벌크막은 순수한 Ar가스를 사용하여 증착되었다. 시드막 증착시 산소 압력이 증가함에 따라, 결정성과 (002) 배향성의 정도는 증가했다. 비저항은 시드가 없는 샘플의 경우 4.7×10?⁴ Ωㆍ㎝로부터 Ar/O₂ = 9/1 샘플의 경우 3.7×10?⁴ Ωㆍ㎝까지, 결정성의 증가와 함께 점차 감소했다. 에칭된 표면은 분화구 형상의 구조를 보여주었으며, 급격한 형상 변화가 결정성 증가와 함께 나타났다. Ar/O₂ = 9/1 조건의 샘플은 500 ㎚에서 88%의 매우 높은 haze 수치를 보여주었으며, 이는 AFM 이미지에서 보여지는 것처럼 큰 표면 구조 크기에 의해 설명된다. ZnO:Al films were deposited by DC-pulsed magnetron sputtering using a two-step process involving the control of the oxygen pressure. The seed layers were prepared with various Ar to oxygen flow ratios and the bulk layers were deposited under pure Ar. As the oxygen pressure during the deposition of the seed layer increased, the crystallinity and degree of (002) texturing increased. The resistivity gradually decreased with increasing crystallinity from 4.7×10?⁴ Ωㆍ㎝ (no seed) to 3.7×10?⁴ Ωㆍ㎝ (Ar/O₂ = 9/1). The etched surface showed a crater-like structure and an abrupt morphology change appeared as the crystallinity was increased. The sample deposited at an Ar/O₂ flow ratio of 9/1 showed a very high haze value of 88% at 500 ㎚, which was explained by the large feature size of the craters, as shown in the AFM image.
Yoon, Taeho,Lee, Taejin,Soon, Jiyong,Jeong, Hyejeong,Jurng, Sunhyung,Ryu, Ji Heon,Oh, Seung M. The Electrochemical Society 2018 Journal of the Electrochemical Society Vol.165 No.5
<P>High voltage positive electrodes for lithium ion batteries have suffered from continuous oxidation of the electrolyte during cycling, which largely offsets the benefits of high energy and power densities. In this work, the electrolyte oxidation and concomitant film deposition/dissolution behaviors were investigated on Pt electrode by using linear sweep voltammetry (LSV), electrochemical quartz crystal microbalance (EQCM), and X-ray photoelectron spectroscopy (XPS). Two characteristics were identified. First, film deposition is relatively unfavorable at higher potentials (>4.7 V vs. Li/Li+) because the oxidation products are mostly gaseous or soluble species. Second, the concentration of inorganic species decreases in the surface film as the potential increases, which is likely dissolved by HF or polar species. The dominance of gaseous or soluble products and the partial dissolution of the surface film, are two characteristics which hamper passivation of the electrode surface, leading to severe electrolyte oxidation at the high potentials. (C) 2018 The Electrochemical Society.</P>
사용자 친화형 웹 기반 ezSIM 플랫폼을 활용한 구조해석 서비스 모델 구현
윤태호(Taeho Yoon),서동우(Dongwoo Seo),박형욱(Hyungwook Park) (사)한국CDE학회 2014 한국 CAD/CAM 학회 학술발표회 논문집 Vol.2014 No.8
구조해석 절차는 중소 제조기업의 제품 납품을 위한 인증 시 설계 절차의 강화 및 프로세스 단축을 이룰 수 있어 설계 프로세스에 필수적인 항목으로 포함되어 가고 있다. 본 연구에서는 해석 부분에 큰 비용 부담을 둘 수 없는 중소중견기업 입장에서 저렴하게 특화 서비스 될 수 있도록 개발한 웹 기반 ezSIM 플랫폼의 일반적 구성 환경과 구조 해석에 적용한 모듈 활용 절차를 소개하였다. 플랫폼에 내재된 ANSYS 소프트웨어를 사용한 복합재료 중공 토션바의 활용 예를 통해 구조 설계 모델의 해석 절차를 사용자 친화형 그래픽 환경에서 사용 가능하고 저렴한 비용과 빠른 병렬처리가 가능케 하는 서비스 모델임을 제시하였다.
Timed Model-Based Formal Analysis of a Scheduler of Qplus-AIR, an ARINC-653 Compliance RTOS
YOON, Sanghyun,LEE, Dong-Ah,PAK, Eunji,KIM, Taeho,YOO, Junbeom 'Institute of Electronics, Information and Communi 2017 IEICE transactions on information and systems Vol.100e.d No.10
<P>Qplus-AIR is a real-time operating system for avionics, and its safety and correctness should be analyzed and guaranteed. We performed model checking a version of Qplus-AIR with the Times model checker and identified one abnormal case that might result in safety-critical situations.</P>
A 103.125-Gb/s Reverse Gearbox IC in 40-nm CMOS for Supporting Legacy 10- and 40-GbE Links
Yoon, Taehun,Lee, Joon-Yeong,Lee, Jinhee,Han, Kwangseok,Lee, Jeong-Sup,Lee, Sangeun,Kim, Taeho,Han, Jinho,Won, Hyosup,Park, Jinho,Bae, Hyeon-Min IEEE 2017 IEEE journal of solid-state circuits Vol.52 No.3
<P>This paper presents the first 103.125-Gb/s multilink gearbox (MLG) IC, which facilitates the transport of independent 10-and 40-GbE signals to 4 x 25.78 Gb/s physical layers, such as 100GBASE-xR4. The IC consumes only 1.37 W while implementing complicated reverse gearbox functionality. The measured TX jitter from 10- and 25-G lanes is 0.407 and 0.448 psrms, respectively. The measured input sensitivities for a BER of 10(-1)2 of the 10- and 25-G RXs are 20 and 42 mVppd, respectively. The proposed gearbox IC, fabricated in a 40-nm CMOS process, occupies 3.7x3.4 mm(2). The power consumption of RX and TX in a 25-G interface is 50.9 and 52 mW, respectively, and those of a 10-G interface are 29 and 24.4 mW, respectively. MLG functionality is verified using embedded self-test logics.</P>
Effect of Li2O Addition on Precipitation Behavior of Uranium in LiCl-KCl-UCl3 Salt
Taeho Kim,Su Jeong Heo,Dalsung Yoon,Seungwoo Paek,Chang Hwa Lee 한국방사성폐기물학회 2022 한국방사성폐기물학회 학술논문요약집 Vol.20 No.2
The effect of Li2O addition on precipitation behavior of uranium in LiCl-KCl-UCl3 has been investigated in this study. 99.99% LiCl-KCl eutectic salt is mixed with 10wt% UCl3 chips at 550°C in the Pyrex tube in argon atmosphere glove box, with 10 ppm O2 and 1 ppm H2O. Then, Li2O chunks are added in mixed LiCl-KCl-UCl3 and the system has been cooled down to room temperature for 10 hours to form enough UO2 particles in the salt. The solid salt has been taken out from the glove box, and cut into three sections (top, middle and bottom) by low-speed saw for further microscopic analysis. Three pieces of solid salt are dissolved in deionized water at room temperature and the solution is filtered by a filter paper to collect non-dissolved particles. The filter paper with particles is baked in vacuum oven at 120°C for 6 hours to evaporate remaining moisture from the filter paper. Further analysis was performed for the powder remaining on the filter paper, and periphery of the powder (cake) on the filter paper. Scanning electron microscopy (SEM), electron diffraction spectroscopy (EDS), and X-ray powder diffraction (XRD) are adopted to analysis the characteristic of the particles. From SEM analysis, the powders are consisted of small particles which have 5 to 10 ?m diameter, and EDS analysis shows they are likely UO2 with 23 at. % of uranium and 77 at. % oxygen. Cake is also analyzed by SEM and EDS, and needle like structures are widely observed on the particle. The length of needle is distributed from 5 to 20 ?m, and it has 6 to 10 at. % of chlorine, which are not fully dissolved into deionized water at room temperature. From XRD analysis, the particles show the peak position of UO2, and the result is well matched with the SEM-EDS results. We are planning to add more Li2O in the system for fully reacting uranium in UCl3, and compare the results to find the effect of Li2O concentration on UO2 precipitation.
Taeho Lim,Yeosol Yoon The Korean Electrochemical Society 2023 Journal of electrochemical science and technology Vol.14 No.4
The high cost of Si-based solar cells remains a substantial challenge to their widespread adoption. To address this issue, it is essential to reduce the production cost of solar-grade Si, which is used as raw material. One approach to achieve this is Si electrodeposition in molten salts containing Si sources, such as SiO<sub>2</sub>. In this study, we present the pulse electrodeposition of Si in molten CaCl<sub>2</sub> containing SiO<sub>2</sub> nanoparticles. Theoretically, SiO<sub>2</sub> nanoparticles with a diameter of less than 20 nm in molten CaCl<sub>2</sub> at 850℃ have a comparable diffusion coefficient with that of ions in aqueous solutions at room temperature. However, we observed a slower-than-expected diffusion of the SiO<sub>2</sub> nanoparticles, probably because of their tendency to aggregate in the molten CaCl<sub>2</sub>. This led to the formation of a non-uniform Si film with low current efficiency during direct current electrodeposition. We overcome this issue using pulse electrodeposition, which enabled the facile supplementation of SiO<sub>2</sub> nanoparticles to the substrate. This approach produced a uniform and thick electrodeposited Si film. Our results demonstrate an efficient method for Si electrodeposition in molten CaCl<sub>2</sub> containing SiO<sub>2</sub> nanoparticles, which can contribute to a reduction in production cost of solar-grade Si.