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        검색결과 55

        1.
        2008.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        신대훈, 김길수, 이영중, 조훈, 김영도
        ZnS- composite is normally used for sputtering target. In recent years, high sputtering power for higher deposition rate often causes crack formation of the target. Therefore the target material is required that the sintered target material should have high crack resistance, excellent strength and a homogeneous microstructure with high sintered density. In this study, raw ZnS and ZnS- powders prepared by a 3-D mixer or high energy ball-milling were successfully densified by spark plasma sintering, the effective densification method of hard-to-sinter materials in a short time. After sintering, the fracture toughness was measured by the indentation fracture (IF) method. Due to the effect of crack deflection by the residual stress occurred by the second phase of fine , the hardness and fracture toughness reached to 3.031 GPa and , respectively
        4,000원
        2.
        2007.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        김해곤, 김길수, 오승탁, 석명진, 김영도
        The sintering behavior and mechanical property of Mo nanopowder was investigated as a function of various sintering condition. Mo oxide nanopowders were milled using a high energy ball-milling process. After the ball milling for 20h, the crystalline size of was about 20 nm. The nanopowders were reduced at the temperature of without holding time in atmosphere. The sinterability of Mo nanopowder and commercial Mo powder was investigated by dilatometric analysis. Mo nanopowder and commercial Mo powder were sintered at for 1 hand for 3 h, respectively. In both specimens the measured relative density was about 95%. But the measured hardness values were 2.34 GPa for nanopowder and 1.87 GPa for commercial powder. Probably due to finer grain size of the sintered body prepared from Mo nanopowder than that prepared using commercial Mo powder. The mean grain sizes were measured to be about 1.4 mm and 6.2 mm, respectively.
        4,000원
        3.
        2007.05 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        조태선, 이승호, 김길수, 김세훈, 김영도
        4,000원
        4.
        2006.05 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        류경환, 송태권, 이재현, 김길수, 이선호, 엄기원
        4,000원
        5.
        2006.05 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        김길수, 조태선, 서영익, 류우석, 김영도
        4,000원
        6.
        2006.05 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        김길수, 조태선, 서영익, 류우석, 김영도
        4,000원
        9.
        2003.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        김길수, 김대건, 김영도
        Recently, the fabrication process of W-Cu nanocomposite powders has been researched to improve the sinterability by mechanochemical process (MCP), which consists of ball milling and hydrogen-reduction with W- and Cu-oxide mixture. However, there are many control variables in this process because the W oxides are hydrogen-reduced via several reduction stages at high temperature over 80 with susceptive reduction conditions. In this experiment, the W-15 wt%Cu nanocomposite powder was fabricated with the ball-milling and hydrogen-reduction process using W and CuO powder. The microstructure of the fabricated W-Cu nanocomposite powder was homogeneously composed of the fine W particles embedded in the Cu matrix. In the sintering process, the solid state sintering was certainly observed around 85 at the heating rate of 1/min. It is considered that the solid state sintering at low temperature range should occur as a result of the sintering of Cu phase between aggregates. The specimen was fully densified over 98% for theoretical density at 120 for 1 h with the heating rate of 1/min.
        4,000원
        11.
        2002.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        이강원, 김길수, 김대건, 김영도
        Recently, the fabrication process of the W-Cu nanocomposite powders has been studied to improve the sinterability through the mechanical alloying and reduction of W and Cu oxide mixtures. In this study. the W-Cu composites were produced by mechanochemical process (MCP) using mixtures with two different milling types of low and high energy, respectively. These ball-milled mixtures were reduced in atmosphere. The ball-milled and reduced powders were analyzed through XRD, SEM and TEM. The fine W-Cu powder could be obtained by the high energy ball-milling (HM) compared with the large Cu-cored structure powder by the low energy ball-milling (LM). After the HM for 20h, the W grain size of the reduced W-Cu powder was about 20-30 nm.
        4,000원
        12.
        1999.12 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        정명모, 김길수, 장기상, 유근배, 박덕근, 김길무, 윤인섭, 홍치유
        4,000원
        13.
        1989.12 구독 인증기관 무료, 개인회원 유료
        박준형, 김영환, 김길수
        Choline과 choline esters인 acetylcholine, methacholine, carbachol, bethanechol이 토끼의 적출장관 운동에 미치는 영향과 각 약물의 값을 산출하여 각각 비교를 하였다. Choline은 최대유효농도가 이었으며 은 이었고 값은 2.619이었다. Acetylcholine은 최대유효농도가 이었으며 에서는 거의 효과가 나타나지 않았고 은 이었고 값은 5.154이었다. Methacholine은 최대유효농도가 이었으며 에서는 거의 효과가 나타나지 않았고 은 이었고 값은 6.045이었다. Carbachol은 최대유효농도가 이었으며 에서는 거의 효과가 나타나지 않았고 은 이었고 값은 6.244이었다. Bethanechol은 최대유효농도가 이었으며 에서는 거의 효과가 나타나지 않았고 은 이었고 값은 5.480이었다. Choline esters는 토끼의 적출장관 운동에 대하여 수축을 일으켰으며 각 약물의 potency의 순서는 carbachol이 가장 강하게 나타났고 methacholine, bethanechol, acetylcholine, choline의 순으로 나타났다.
        4,000원
        15.
        2016.10 서비스 종료(열람 제한)
        주용선, 김영준, 백승제, 유병옥, 김길수, 진영관, 김희문, 안상복
        17.
        2016.05 서비스 종료(열람 제한)
        홍권표, 김성근, 오완호, 정상희, 박명철, 진영관, 김길수
        18.
        2016.05 서비스 종료(열람 제한)
        주용선, 김길수, 백승제, 유병옥, 김영준, 진영관, 김희문, 안상복
        19.
        2015.10 서비스 종료(열람 제한)
        김영준, 허기수, 진영관, 유병옥, 백승제, 정양홍, 김길수, 주용선, 안상복
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