• Title/Summary/Keyword: Repeated Structures

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Basic Study in Fabrication and Mechanical Characteristics of Ultra Light Inner Structured and Bonded(ISB) Panel Containing Perpendicularly Woven Metal (수직방향 직조 금속망을 이용한 초경량 금속 내부구조 접합판재의 제작 및 특성에 관한 기초 연구)

  • Jung Chang Gyun;Yoon Seok-Joon;Yang Dong-Yol;Lee Sang Min;Na Suck-Joo;Lee Sang-hoon;Ahn Dong-Gyu
    • Journal of the Korean Society for Precision Engineering
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    • v.22 no.5 s.170
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    • pp.152-158
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    • 2005
  • Inner structured and bonded panel, or ISB Panel, as a kind of sandwich type panel, has metallic inner structures which have low relative density, due to their dimensional shape of metal between a pair of metal skin sheets or face sheets. Previous works showed that ISB panels containing inner structures formed as repeated pyramidal shapes saved weight up to $60\%$ in condition of same stiffness comparing with solid sheet. In this work, woven metal is adapted to inner structures replacing pyramidal structures. The test specimens of ISB panel containing woven metal made by multi-point electric resistance welding and 3-point bending test have been carried out. The results of experiments and comparisons of process parameters, stiffness and failure mode are discussed.

Flavonol Galactosides from Artemisia apiacea

  • Kim, Kyoung-Soon;Lee, Sang-Hyun;Kang, Kyoung-Hwan;Kim, Bak-Kwang
    • Natural Product Sciences
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    • v.11 no.1
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    • pp.10-12
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    • 2005
  • Flavonol galactosides were isolated from the EtOAc fraction of Artemisia apiacea by repeated column chromatography. Their structures were elucidated as $isorhamnetin-3-O-{\beta}-D-galactoside$ (1) and $quercetin-3-O-{\beta}-D-galactoside$ (2) by chemical and spectroscopic analysis. This is the first report on the isolation of compound 2 from this plant.

Buckling of cylindrical shells under external pressure proposition of a new shape of self-stiffened shell

  • Araar, M.;Jullien, J.F.
    • Structural Engineering and Mechanics
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    • v.4 no.4
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    • pp.451-460
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    • 1996
  • We propose a new shape of cylindrical shell formed by multiples vaults which gives a self-stiffening against buckling. By an experimental and numerical study of cylindrical shells with a repeated defect, on the circumferential direction made only of outside oriented wave-defects, we show that multiple vault cylindrical shells can have a good behaviour in buckling. An optimal behaviour is obtained by optimization of the vaults number, with conduces to a special multiple vault cylindrical shell named "ASTER shell".

Antitumor and Antiinflammatory Constituents from Celtis sinensis

  • Kim Dae Keun;Lim Jong Pil;Kim Jin Wook;Park Hee Wook;Eun Jae Soon
    • Archives of Pharmacal Research
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    • v.28 no.1
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    • pp.39-43
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    • 2005
  • Eight compounds were isolated from the methanolic extract of the twigs of Celtis sinensis through repeated silica gel and Sephadex LH-20 column chromatography. Their chemical structures were elucidated as two triterpenoids, germanicol and epifriedelanol, two amide compounds, trans-N-caffeoyltyramine and cis-N-coumaroyltyramine, two lignan glycoside, pinoresinol glycoside and pinoresinol rutinoside, and two steroids by spectroscopic analysis.

Design Practice of a Vehicle Mounted Platform Servo Control System Slaved to the Independently Controlled Tracking System

  • 안태영;강태하;손승걸;조성훈;최영호
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 1992.10a
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    • pp.209-214
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    • 1992
  • This paper presents a one cycle R&D project regarding the large inertia platform servo control system. The steps followed the rather orthodox procedure. A serial double rate-loop was closed with a position loop, and acceleration velocity anticipatory compensations were designed in the forward path. Some appropriate compensation devices were utilized for the signal processing as well as for the better control quality. Simulations and experimental tests were repeated, and satisfactory performances were observed. However, frequency domain uncertainties inherent to the large structures still remain as an expertise supported subject.

Iridoid Compounds from the Whole Plant of Galium verum var. asiaticum

  • Lee, Tae Gwan;Kim, Dae Keun
    • Natural Product Sciences
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    • v.19 no.3
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    • pp.227-230
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    • 2013
  • One new iridoid glycoside, 10-p-dihydrocoumaroyl-6-${\alpha}$-hydroxygeniposide (1), and six known iridoid glycoside derivatives, 10-p-dihydrocoumaroyl deacetylasperuloside (2), asperulosidic acid methylester (3), asperuloside (4), asperulosidic acid (5), deacetylasperuloside (6), and scandoside (7) were isolated from the methanolic extract of the whole plant of Galium verum var. asiaticum Nakai (Rubiaceae) through repeated column chromatography. Their chemical structures were characterized by spectroscopic analysis. This is the first report of the characterization of compounds 1 - 7 from this plant.

CO2 reforming of methane based on TiO2/Ni-based catalysts

  • Kim, Dong-Wun;Seo, Hyun-Ook;Kim, Kwang-Dae;Dey, Nilay Kumar;Kim, Myoung-Joo;Jeong, Myoung-Geun;Kim, Young-Dok
    • Proceedings of the Korean Vacuum Society Conference
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    • 2010.08a
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    • pp.60-60
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    • 2010
  • CO2 reforming of methane (CRM) based on Ni catalysts was studied using temperature programmed reaction (TPR). The onset temperature of the CRM reaction was increased in a repeated TPR experiments. X-ray photoelectron spectroscopy (XPS) and Raman spectroscopy showed formation of graphite structures on Ni during CRM reaction, which deactivate Ni-surfaces. Attempts were made for inhibiting deactivation of Ni surfaces and reducing onset-temperature of the CRM reaction by various surface modification techniques, which will be presented in this poster.

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Iridoid Compounds from Boschniakia rossica

  • Yin, Zong-Zhu;Kim, Hang-Sub;Kim, Young-Ho;Lee, Jung-Joon
    • Archives of Pharmacal Research
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    • v.22 no.1
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    • pp.78-80
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    • 1999
  • Four iridoid compounds were isolated from methanol extract of Boschniakia rossica by repeated column chromatography. Their structures were determined as boschnaloside (1), boschnarol (2), bosnarol methylether (3), and 7-deoxy 8-epiloganic acid (4), respectively. Compound 2, 3, and 4 were isolated for the first time form this plant.

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C-Glycosylflavonoids from the Whole Plants of Setaria faberi Herrmann (가을강아지풀의 C-Glycosylflavone 성분)

  • Kim, Dae Keun
    • Korean Journal of Pharmacognosy
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    • v.47 no.3
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    • pp.222-225
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    • 2016
  • Four flavone compounds were isolated from the whole plants of Setaria faberi Herrmann (Gramineae) through repeated column chromatography. Their chemical structures were elucidated as tricin (1), and three C-glycosylflavone, 2"-O-rhamnosylvitexin (2), 2"-O-rhamnosylscoparin (3), and 2"-O-rhamnosylorientin (4), respectively, by spectroscopic analysis. These compounds were isolated for the first time from this plant.

Phytochemical Constituents of Panicum dichotomiflorum Michaux (미국개기장의 식물화학적 성분)

  • Bae, Jong Jin
    • Korean Journal of Pharmacognosy
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    • v.48 no.4
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    • pp.285-288
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    • 2017
  • A lignan and four flavonoid derivatives were isolated from the aerial parts of Panicum dichotomiflorum Michaux (Gramineae) through repeated column chromatography. Their chemical structures were identified as (-)-pinoresinol (1), tricin (2), luteolin (3), luteolin-4'-O-${\beta}$-D-glucopyranosde (4) and luteolin-7-O-${\beta}$-D-glucopyranosde (5), respectively, by spectroscopic analysis. These compounds were isolated for the first time from this plant.