• 제목/요약/키워드: compositional

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Atom Probe Tomography를 이용한 나노 스케일의 조성분석: I. 이론과 설비 (Nano Scale Compositional Analysis by Atom Probe Tomography: I. Fundamental Principles and Instruments)

  • 정우영;방찬우;구길호;박찬경
    • Applied Microscopy
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    • 제41권2호
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    • pp.81-88
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    • 2011
  • 최근 나노 영역에서의 구조분석과 조성분석의 중요성이 증대되고 있으나, 기존의 분석장비들은 한계에 부딪히고 있다. 최근 개발된 APT는 nm 이하의 공간분해능과 수십 ppm수준의 detection limit으로 원소의 3차원분포와 조성정보를 제공해 주는 분석장비로서, 이러한 기존 분석의 한계를 극복할 수 있는 새로운 분석장비이다. 그러나 국내에는 아직 잘 알려지지 않아 활용이 미비한 실정이다. 따라서, 본 논문에서는 APT에 대한 이해를 돕기 위해 APT분석의 원리와 시편준비에 대해 소개하였다.

Annealing Effect on Exchange Bias in NiFe/FeMn/CoFe Trilayer Thin Films

  • Kim, Ki-Yeon;Choi, Hyeok-Cheol;You, Chun-Yeol;Lee, Jeong-Soo
    • Journal of Magnetics
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    • 제13권3호
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    • pp.97-101
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    • 2008
  • We investigated the exchange bias fields at the NiFe/FeMn and FeMn/CoFe interfaces in 18.9-nm NiFe/15.0-nm FeMn/17.6-nm CoFe trilayer thin films as the annealing temperature was varied from room temperature to $250^{\circ}C$ in a vacuum for 1 hour in a magnetic field of 150 Oe. Interestingly, magnetic hysteresis (M-H) measurements showed that NiFe/FeMn/CoFe trilayer thin films exhibited a completely contrasting variation of the exchange bias fields at both the NiFe/FeMn and FeMn/CoFe interfaces with annealing temperatures. High-angle X-ray diffraction (XRD) measurements indicated the absence of any discernible effect of thermal treatment on the NiFe(111) and FeMn(111) peaks. The compositional depth profile obtained from X-ray photoelectron spectroscopy (XPS) results presented the asymmetric compositional depth profiles of the Mn and Fe atoms throughout the FeMn layer. We contend that this asymmetric compositional depth profile and the preferential Mn diffusion into the NiFe layer, compared to that into the CoFe layer, are conclusive experimental evidence of the contrasting variation of the exchange bias fields at two interfaces having a common polycrystalline FeMn(111) layer.

미궁과 미로의 구성원리 분석을 통한 현대 건축 공간특성에 관한 연구 - 전시 공간을 중심으로 - (A Study on the Spatial Characteristics of the contemporary architecture through the Compositional Principle in Labyrinth and Maze - Focused on the Exhibition Space -)

  • 임종엽;김윤겸
    • 한국실내디자인학회논문집
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    • 제14권3호
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    • pp.12-19
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    • 2005
  • In contemporary society, Labyrinth and maze are used with the same meaning. They are also used by translating various meanings. But labyrinth and maze are exactly different meaning. The purpose of this study is to inquire about difference for understanding essential meaning between labyrinth and maze. First of all, this study is to grasp composition principles and the characteristics of space through example of labyrinth and maze from ancient to contemporary, prescribe about essential meaning between labyrinth and maze and examine contemporary architecture which is fit for essential meaning. As compositional Principle in labyrinth and maze applied to comtemporary architecture, the labyrinth are centrality, property of one-sideness, determinable space, on the contrary the maze are out of centrality, property of multi-sideness, indeterminable space. Finally, The aim of this paper is analyze exhibition space that suit to the characteristics of composition principle and find the characteristics in labyrinth and maze. Examples of exhibition space are Aldo Van Eyck's 'Sculpture Pavilion', Kazuyo Sejima's '21st Century Museum of Contemporary Art', Ben van berkel's'Museum Het Valkhof'. These research we studied the visitor's circulation and the architectural structure in exhibition space with the spatial characteristics and the compositional principle in labyrinth and maze.

Influence of MBE Growth Temperature on the Sulfur Compositional Variation Of ZnSSe Epitaxial Layers on GaAs Substrates

  • Kim, Dong-Lyeul;Bae, In-Ho;Son, Jeong-Sik;Kim, In-Su;Lee, Jae-Young m;Akira Yoshida
    • Transactions on Electrical and Electronic Materials
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    • 제1권3호
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    • pp.18-22
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    • 2000
  • In this work, we reported the sulfur compositional variation of ZnS$\_$x/Se$\_$1-x/ epitaxial layers with growth temperature and BEP ration of ZnX/Se/)P$\_$ZnS//P$\_$Se/) grown on GaAs substrates by molecular beam epitaxy. The sulfur composition of ZnSSe epitaxial layers was varied sensitively on the growth temperature and show different linear relationship with growth temperature and BEP ration of ZnS/Se(P$\_$ZnS//P$\_$Se/), which revealed -0.107 %$\^{C}$ at (P$\_$ZnS//P$\_$Se/)=0.30 and -0.052 %$\^{C}$ at (P$\_$ZnS//P$\_$Se/)=0.158 rspectively. A reference data for the accurate control of the sulfur composition and the growth of high quality ZnSSe/GaAs epitaxial layers was provided.

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Measurement of Socioeconomic Position in Research on Cardiovascular Health Disparities in Korea: A Systematic Review

  • Lee, Chi-Young;Lee, Yong-Hwan
    • Journal of Preventive Medicine and Public Health
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    • 제52권5호
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    • pp.281-291
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    • 2019
  • Objectives: The validity of instruments measuring socioeconomic position (SEP) has been a major area of concern in research on cardiovascular health disparities. The purpose of this systematic review is to identify the current status of the methods used to measure SEP in research on cardiovascular health disparities in Korea and to provide directions for future research. Methods: Relevant articles were obtained through electronic database searches with manual searches of reference lists and no restriction on the date of publication. SEP indicators were categorized into compositional, contextual, composite, and life-course measures. Results: Forty-eight studies published from 2003 to 2018 satisfied the review criteria. Studies utilizing compositional measures mainly relied on a limited number of SEP parameters. In addition, these measures hardly addressed the time-varying and subjective features of SEP. Finding valid contextual measures at the organizational, community, and societal levels that are appropriate to Korea's context remains a challenge, and these are rarely modeled simultaneously. Studies have rarely focused on composite and life-course measures. Conclusions: Future studies should develop and utilize valid compositional and contextual measures and appraise social patterns that vary across time, place, and culture using such measures. Studies should also consider multilevel influences, adding a focus on the interactions between different levels of intertwined SEP factors to advance the design of research. More attention should be given to composite and life-course measures.

유체해석 프로그램을 이용한 골재의 입자크기 및 입도, 구성위치에 따른 배수층의 특성 평가 (Evaluation of characteristics of drainage layer according to particle size, particle size, and compositional location of aggregate using fluid analysis program)

  • 임창민;권현우;김영민;조도영;이건철
    • 한국건축시공학회:학술대회논문집
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    • 한국건축시공학회 2022년도 가을 학술논문 발표대회
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    • pp.147-148
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    • 2022
  • Due to recent climate abnormalities, the form of rainfall is changing to localized torrential rains. Localized torrential rains cause flooding in urban areas. In addition, in various industrial fields, there are cases where materials necessary for the process are kept outdoors, and damage from material loss and flooding of stockyards occurs during heavy rain. Accordingly, it is necessary to introduce a drainage layer where flooding is expected. This drainage layer places the aggregate inside and allows rainwater to penetrate and drain into the voids between the aggregates. However, the amount of voids differs according to the particle size distribution and particle size of the aggregate, and the drainage performance varies according to the compositional location of the aggregate. Therefore, in this study, the drainage characteristics according to the particle size, particle size, and compositional location of aggregates are analyzed using a fluid analysis program.

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