• 제목/요약/키워드: membrane property

검색결과 347건 처리시간 0.023초

중공사 나노여과막을 이용한 방향족 농약의 배제 특성 (Rejection Properties of Aromatic Pesticides by a Hollow Fiber NF Membrane)

  • 정용준;키소 요시아키;박순길;김종용;민경석
    • 한국물환경학회지
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    • 제20권3호
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    • pp.296-300
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    • 2004
  • The rejection properties of 6 aromatic pesticides were evaluated by a continuous flow system equipped with a hollow fiber NF membrane. Different from the separation experiment of batch cell, the rejection and the removal could be calculated exactly because the concentration of feed, permeate and retentate was separately obtained. The lowest and the highest rejection were found in carbaryl(54.8%) and methoxychlor(99.2%), respectively, and the removals were always shown higher than rejections. This may be caused by some reasons such as the solute adsorption on the membrane, the variation of feed concentration. Although molecular weight, molecular width regarded as solute characteristics and log P(n-octanol/water partition coefficient) as hydrophobicity could be applied to explain the rejection property, these factors should be considered together for better analysis. According to the higher relationship between log B(solute permeability) and molecular weight, it was revealed that the solute separation with this membrane was influenced more by molecular weight.

Analysis on the Amino Acid Distributions with Position in Transmembrane Proteins

  • Chi, Sang-Mun
    • Journal of the Korean Data and Information Science Society
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    • 제16권4호
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    • pp.745-758
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    • 2005
  • This paper presents a statistical analysis on the position-specific distributions of amino acid residues in transmembrane proteins. A hidden Markov model segments membrane proteins to produce segmented regions of homogeneous statistical property from variable-length amino acids sequences. These segmented residues are analyzed by using chi-square statistic and relative-entropy in order to find position-specific amino acids. This analysis showed that isoleucine and valine concentrated on the center of membrane-spanning regions, tryptophan, tyrosine and positive residues were found frequently near both ends of membrane.

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표면 개질된 나노복합막의 투과 특성 (Permeation Property of Surface Modified Nanofiltration Membrane)

  • 박형규;탁태문;장경국;김은영;장하원;배태현
    • 한국막학회:학술대회논문집
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    • 한국막학회 2004년도 춘계 총회 및 학술발표회
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    • pp.153-155
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    • 2004
  • 상전이법으로 제조된 비대칭막은 세공의 크기를 nm이하의 수준으로 줄여 주면 막 여과저항이 크게 증가하여 경제성이 떨어지는 문제점을 가지고 있다. 이에 대한 대안으로 복합막이 제조되어 사용되고 있는데, 복합막은 우수한 투과도와 높은 배제율을 달성하기 위한 적극적인 대안이 되고 있다. 정수처리 및 수질환경 분야에 사용되는 나노복합막의 경제성을 더욱 향상시키기 위해서는 나노막의 투과유속을 증가시켜야 하는데, 복합막의 투과 성능은 지지체의 특성과 스킨층을 형성시키는 기술에 의해 좌우된다.(중략)

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개폐식 대공간 구조물에서 지붕 맞댐부 우수차단 시스템의 수밀성 평가에 관한 연구 (Watertightness Property Evaluation of Rain-Block System)

  • 김윤호;백기열;김종수;이선규;오상근
    • 한국건축시공학회:학술대회논문집
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    • 한국건축시공학회 2010년도 춘계 학술논문 발표대회 1부
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    • pp.13-16
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    • 2010
  • This study is an Investigation on the Watertightness Properties of Rain-Block System on the Sliding-Roof Joint of Large-Span Membrane Structures. In this experimental, we test the watertightness performance of joint part of sliding door in roof of large span membrane structure(for pilot project) under environment of rain and wind. A shape of rain water blocking systems of joint part in sliding door verifies the defects and effects of water leakage prevention in precipitation with the wind conditions. For obtaining watertightness of large span membrane structures, it is necessary quality of joints and performance, and quality of membrane material of a retractable roof as well as a closed roof. Also, for obtaining quality in joints, it is essential to make a watertightness guideline for design of large-span membrane.

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Separation of Dichlorinated Bydrocarbons by Pervaporntion Using ZSM-5 Zeolite Membrane

  • Lee, Young-Jin;Lee, Hye-Ryeon;Shim, Eun-Young;Ahn, Hyo-Sung;Lee, Yong-Taek
    • Korean Membrane Journal
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    • 제7권1호
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    • pp.51-57
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    • 2005
  • Pervaporation with a membrane is one of the economic technologies for separation of liquid mixtures including organic/water mixtures. The ZSM-5 membrane was used fur pervaporation of dichloromethane, 1,2-dichloroethane and trans-1,2-dichloroethylene from their aqueous solutions since its physical property shows very hydrophobic. ZSM-5 crystals were hydrothermally grown and deposited on the inside of a porous sintered stainless steel tube by the secondary growth method. Fluxes of dichlorinated organic compounds were observed to be $50{\~}429\;g/m^2/h$ while separation factors were $15{\~}320$ depending on a mole fraction of a dichlorinated organic compound in a feed solution ranged from 0.0001 to 0.001 mole fraction and the operation temperature between $25^{\circ}C\;and\;35^{\circ}C$.

막구조물의 파손단면에서의 응력집중 현상에 관한 연구 (A Study on the Stress Concentration at Crack of Membrane Structures)

  • 전진형;정을석;김승덕
    • 한국공간구조학회:학술대회논문집
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    • 한국공간구조학회 2005년도 춘계학술발표회 및 정기총회 2권1호(통권2호)
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    • pp.89-98
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    • 2005
  • Membrane structures, a kind of lightweight soft structural system, are used for spatial structures. The material property of the membrane has strong axial stiffness, but little bending stiffness. Therefore membrane structures arc unstable structures initially. These soft structures need to be introduced initial stresses first because of its initial unstable state, and it happens large deformation phenomenon. To find the structural shape after large deformation caused by initial stiffness introduced, we need the shape analysis considering geometric nonlinearity in structural design procedure. In this study, we investigate into the stress concentration at crack of membrane structures. Therefore, using the nonlinear analysis program that NASS (Nonlinear Analysis for Spatial Structures) perform nonlinear analysis, and stress distribution for creak length investigate for using linear elastic fracture mechanics.

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막 구조물의 측지선을 이용한 재단도 생성에 관한 연구 (A Study on Cutting Pattern Generation of Membrane Structures by Using Geometric Line)

  • 안상길;손수덕;김승덕
    • 한국공간구조학회:학술대회논문집
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    • 한국공간구조학회 2005년도 춘계학술발표회 및 정기총회 2권1호(통권2호)
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    • pp.125-132
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    • 2005
  • Membrane structures, a kind of lightweight soft structural system, are used for spatial structures. The material property of the membrane has strong axial stiffness, but little bending stiffness. The design procedure of membrane structures are needed to do shape finding, stress-deformation analysis and cutting pattern generation. In shape finding, membrane structures are unstable structures initially. These soft structures need to be introduced initial stresses because of its initial unstable state, and it happens large deformation phenomenon. And also there are highly varied in their size, curvature and material stiffness. So, the approximation inherent in cutting pattern generation methods is quite different. Therefore, in this study, to find the structural shape after large deformation caused by Initial stress, we need the shape analysis considering geometric nonlinear ten And the geodesic line on surface of initial equilibrium shape and the cutting pattern generation using the geodesic line is introduced.

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Preparation of Cross-linked Asymmetric Membrane and Control of Its Morphology and Mechanical Property

  • Hong, Byung-Pyo;Ko, Moon-Young;Kwon, Byeong-Min;Byun, Hong-Sik
    • Korean Membrane Journal
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    • 제10권1호
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    • pp.1-7
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    • 2008
  • Polystyrene-co-divinylbenzene (PS-co-DVB) asymmetric membranes were prepared. In order to control their structure and mechanical properties the degree of cross-linking and the composition of casting solution were varied. The rubber added PS-DVB membranes was also prepared to overcome the mechanical limitation of cross-linked membrane, and their mechanical properties were investigated. It was revealed that the concentration of polymer in the casting solution affected the determination of skin formation. When the PS-co-DVB membrane consists of styrene-butadiene (SB) rubber or liquid polybutadiene (PBD), the structures formed showed that the PS content in the PS/DVB system played an important role in determining the porous sublayer structure.