• Title/Summary/Keyword: Applied Research

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Identification of inseticidal compound SR 2077 from Actinomycetes isolate No. 2077 (방선균 분리주 No. 2077이 생산하는 살충성 물질 SR 2077의 구조 동정)

  • Oh, Sei-Ryang;Lee, Hyeong-Kyu;Choi, Soo-Keun;Kim, Jeong-Il
    • Applied Biological Chemistry
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    • v.37 no.4
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    • pp.234-236
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    • 1994
  • During the screening of insecticidal compounds from soil microorganisms, SR 2077 was isolated from the metabolites of Actinomycetes isolate No. 2077 and identified as albocycline by UV and NMR data analyses.

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Performance evaluation of Superconducting synchronous motor via Finite element method (유한요소법을 이용한 고온초전도 동기모터 특성해석)

  • Baik, S.K.;Kim, S.W.;Sohn, M.H.;Jo, Y.S.;Seo, M.G.;Kwon, Y.K.;Ryu, K.S.
    • Proceedings of the KIEE Conference
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    • 2002.07b
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    • pp.720-722
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    • 2002
  • Superconducting synchronous motor using HTS(high-temperature superconducting) field windings has a lot of advantages over LTS(Jow-temperature superconducting) synchronous machine. A recently developed 5000[hp] HTS motor represents 1/2 reduction in weight and volume compared to an induction type conventional machine. Furthermore. 40% machine loss is reduced compared to the industry average. Based on a conceptual design, a 100[hp] HTS synchronous motor is modeled by F.E.M(Finite Element Method) and the performance is predicted in this paper

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Effect of pre-annealing conditions on critical current density of Bi-2223 tapes

  • Ha, Dong-Woo;Yang, Joo-Saeng;Ha, Hong-Soo;Oh, Sang-Soo;Lee, Dong-Hoon;Hwang, Sun-Yuk;Park, Jung-Gyu;Kwon, Young-Kil
    • Progress in Superconductivity and Cryogenics
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    • v.5 no.1
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    • pp.31-34
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    • 2003
  • Bi-2223 superconducting wires with 55 filaments were fabricated by stacking, drawing process with different heat-treatment histories. Two kinds of powders were prepared. One was pre-annealed at 760-820 $^{\circ}C$ and low oxygen partial pressure, and the other was only calcined state. Before rolling process, round wires were pre-annealed at 760 -820 $^{\circ}C$ and in a low oxygen partial pressure. We confirmed that pre-annealing step was to transform Bi-2212 orthorhombic structure from Bi-2212 tetragonal structure and to reduce the formation of second phases at superconducting wire. However Bi-2223 phases were formed at higher pre-annealing temperature. Bi-2223 conductor was needed frequently annealing at low temperature because pre-annealing at precursor powder brought about decrease in workability. We could achieve highest Je of 6500 A/$\textrm{cm}^2$ at the tape using Bi-2212 orthorhombic phase by introduced slightly overheating at the 1st sintering process.

Development of 30kVA Superconducting Generator (I) : Structure and Manufacturing (30kVA 초전도발전기 개발 (I) : 구조와 제작)

  • Sohn, M.H.;Baik, S.K.;Kwon, Y.K.;Ko, R.K.;Bae, J.H.;Lee, E.Y.;Jin, H.B.;Ryu, K.S.
    • Proceedings of the KIEE Conference
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    • 1999.07a
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    • pp.229-231
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    • 1999
  • For the first time in Korea, a 30kVA superconducting generator has been designed, developed and successfully tested recently. This is the forerunner of a 1MVA superconducting generator which is currently under development. The paper discusses the structure and manufacturing of a superconducting generator. Helium transfer coupling has 3 passages of the recovered Helium gas and a gas flow control system.

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Stability of Triplet NbTi Cable-In-Conduit Conductor (NbTi 관내 3연선 도체의 안정성)

  • Jang, H.M.;Oh, S.S.;Ha, D.W.;Ha, H.S.;Bae, J.H.;Kim, S.C.;Ryu, K.S.;Wang, Q.L.
    • Proceedings of the KIEE Conference
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    • 1998.07a
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    • pp.82-84
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    • 1998
  • The normal zone propagation velocity and minimum quench energy (MQE) of cable-in-conduit conductors (CICC) has been investigated at the different background magnetic fields and supercritical helium pressures. The sample CICC of 2 m in length was fabricated with triplet NbTi/Cu strands inserting into a round stainless-steel tube. The heat pulse disturbance with duration time about 400 ms was acted on the center region of the CICC to quench the strands. The normal zone propagation velocity increased with operating current of the CICC. The measured velocity with respect to operation current could be fitted with numerical results.

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