• 제목/요약/키워드: Molecular Surface

검색결과 2,086건 처리시간 0.034초

전도성 블랜드의 AC와 DC에 대한 전기적 특성 (Electrical Properties of Conducting Blends for AC & DC)

  • 이태희;김종은;김윤상;서광석
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2003년도 하계학술대회 논문집 C
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    • pp.1481-1483
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    • 2003
  • Molecular motions of polyaniline conducting blends were prepared. Surface resistance of its blends was investigated by a Surface Resistance Meter. DC electrical properties were investigated by Thermally Stimulated Currents(TSC) method and AC dielectric properties were investigated by Dielectric Thermal Analyzer (DETA) in the temperature range from $-50^{\circ}C$ to $120^{\circ}C$ at 1E0 Hz $^{\sim}$ 1E7 Hz for a comparative study of molecular relaxation. Using Scanning Electron Microscopy(SEM), relations of both microstructure and conduction behaviors was observed.

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HTV 실리콘 고무에서 열화인자에 따른 저분자량 성분과 표면 발수성의 변화 (Effects of Ageing Factors on Low Molecular Weight Silicone Fluids Content Fluids Content and Surface Hydrophobicity in HTV Silicone Rubber)

  • 허창수;연복희;조한구
    • 한국전기전자재료학회논문지
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    • 제12권1호
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    • pp.1-10
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    • 1999
  • In this paper, we have investigated the effects of the environmental factors on Low Molecular Weight (LMW) silicone fluid contents existing in high temperature vulcanized (HTV) silicone rubber sample, using dipping method and contact angle, current measurement. Artificial treatments such as immersion in water, elevated temperature, UV irradiation and dry band arcing under salt-fog condition are selected as the environmental factors. This results will be helpful to investigate the degradation with time and to expect a life time, because the LMW silicone content, which is important to recovery the hydrophobicity of silicone rubber surface, show different results by each environmental factors.

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코로나 방전에 따른 실리콘 고무의 표면 특성 (Surface Characteristics of Silicone Rubber Processes by Corona Discharges)

  • 한동희;조한구;강동필;민경은
    • 한국전기전자재료학회논문지
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    • 제15권2호
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    • pp.133-140
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    • 2002
  • This paper aims to investigate the effect of silicone oils as processing agent affecting the loss and recovery of hydrophobicity. The recovery of hydrophobicity was evaluated by the measurement of the surface electrical resistivity and the contact angle on the SIR surface. Two kinds of silicone oils (1 and 2) having different molecular weight were selected under a consideration of hydrophobicity and processability. SIR specimens were exposed to corona discharges in air and the specimens were analyzed with contact angle and surface resistance measurements. It was observed that the contact angle and the surface resistivity of SIR increase gradually with testing time. The fast recovery of hydrophobicity of SIR, expressed by the increment of contact angle and surface resistivity, was showed in SIR2 containing silicone oil 2.

아연전기도금의 존착성에 미치는 폴리에탈렌글리콜의 영향 (The Effect of polyethlenglycol on Electrocrystallization of zine Coat)

  • 김현태;정원섭;조남웅
    • 한국표면공학회지
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    • 제30권2호
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    • pp.128-135
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    • 1997
  • The effect of the polyethyledglycol(PEG) on the surface morphology and crystal orientation of electrodeposited zinc from a chloride (1.5M Zinc+7.0M chloriode) have been studied by means of electrochemical methodes, scanning electron microscopy, surface appearance measurement and X-ray diffraction patterns. The resistance of electrodeposit increased, whereas the evolution of hydrogen decreased with incrasing of molecular weight of the PEG. Large grains of electrodeposit were obtained from bath in the absence of organid additive. When the PEG was added, fine grained crystals were observed and the surface roughness was relatively small, but surface appearance deteriorated. The preferred orientation with a(101) plane parallel to the surface was obtained from the PEG addited bath.

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양이온교환막 표면의 전기투석 물분해에서 다가의 큰 이온성분자에 의해 형성된 고정층 바이폴라 계면의 영향 (Effects of Immobilized Bipolar Interface Formed by Multivalent and Large Molecular Ions on Electrodialytic Water Splitting at Cation-Exchange Membrane Surface)

  • Seung-Hyeon Moon;Moon-Sung Kang;Yong-Jin Choi
    • 멤브레인
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    • 제13권3호
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    • pp.143-153
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    • 2003
  • 본 연구에서는 양이온교환막 표면에 형성된 바이폴라 계면이 물분해 현상에 미치는 영향을 조사하였다. 실험결과, 전기투석 중 막표면에 형성된 고정화된 바이폴라 계면이 심각한 물분해를 유발함을 알 수 있었다. 특히, 고정화된 바이폴라 계면은 다가 양이온이 전해질로 이용되는 전기투석 시스템에서 양이온교환막 표면에 쉽게 형성됨을 알 수 있었다. 낮은 용해도적 상수를 갖는 다가 양이온들은 급격한 물분해를 유발하였는데 이는 이들이 막표면에서 쉽게 수산화물의 형태로 침적되며 따라서 수소-친화 그룹과 수산화-친화 그룹으로 구성된 바이폴라 계면이 막-용액 계면에 형성됨을 알 수 있었다. 따라서 물분해는 막 표면의 금속수산화물 층과 막의 고정전하 그룹간에 발생되는 강한 전기장에 의해 크게 활성화됨을 알수 있다. 또한 이와 유사하게 분자량이 큰 유기 상대이온들이 막표면에 누적되는 경우에도 고정화된 바이폴라 계면이 형성되어 한계전류밀도 이상에서 심각한 물분해를 유발하였다. 따라서 전기투석의 고전류 운전시 효율 향상을 위해서는 막표면에 유발되는 고정화된 바이폴라 계면의 형성을 억제하는 것이 매우 중요함을 알 수 있다.

Molecular analysis of c-terminus structure for elucidating the stabilization effect of site-specific immobilization

  • 백승필;유영재
    • 한국생물공학회:학술대회논문집
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    • 한국생물공학회 2001년도 추계학술발표대회
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    • pp.886-889
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    • 2001
  • C-terminus specific immobilization often results in a increased structural stability resistant to various denaturation factors. In order to elucidate the immobilization effect on the c-terminus in molecular level, we made over 200 protein data set from Protein Data Bank(PDB), analyzed c-terminus structure of each protein, and investigated the structural relationship with the stabilizing factors such as hydrogen bond, ion pairs, cation pi, disulfide bond, solvation free energy, surface area, flexibility and so on.

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폴리설폰 중공사막 혈액여과기의 설계 및 여과성능 (Design and Filtration Performance of Polysulfone Hollow Fiber Membrane Hemofilter)

  • 김재진;박진용
    • 대한의용생체공학회:의공학회지
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    • 제14권3호
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    • pp.227-234
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    • 1993
  • Hemofilter was optimally designed and manufactured using polysulfone hollow fiber mem- brane with surface area of 0.6mE Molecular weight cut-off of the hemofilter was measured with polyethylene glycol and dextran aqueous solutions of various molecular weights and it was ranged from 9,500 to 38,900. Ultrafiltration rates were measured with pure water in a static system and flowing system. The clearance of urea, creatinlne, and vitamine BIB were measured using aqueous solutions.

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Interfacial Charge and Mass Transfer at Graphene-SiO2 Substrates: Raman Spectroscopic Studies

  • 류순민
    • 한국진공학회:학술대회논문집
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    • 한국진공학회 2014년도 제46회 동계 정기학술대회 초록집
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    • pp.115.1-115.1
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    • 2014
  • Atom-thick 2-dimensional materials such as graphene, h-BN and MoS2 hold substantial potential for applications in future molecular-scale integrated electronics, transparent conducting membranes, nanocomposites, etc. From a fundamental point of view, 2-dim crystal-solid substrates can also serve as a unique system to study various physicochemical phenomena occurring at low dimensions or interfaces. In this talk, I will present our recent Raman spectroscopy studies on the surface science problems of graphene: interfacial charge transfer, molecular diffusion in confined space and structural deformation.

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$CsX^+$(X=Al, Ga, As) 분자이온을 이용한 SIMS의 정량분석 (The Detection of Molecular Ion $CsX^+$(X=Al, Ga, As) for Quantitative SIMS Analysis)

  • 김차연;김선미;김성태;지종열
    • 한국진공학회지
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    • 제1권1호
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    • pp.121-125
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    • 1992
  • Secondary Ion Mass Spectrometry (SIMS) is widely known as highly sensitive a surface analysis technique. Efforts for quantification have been hindered, however, by the presence of matrix effects. Here we describe a new technique for the quantitative analysis of AlxGa1-xAs. Instead of Al+, Ga+, As+ ions, CsX+ ions (X=Al, Ga, As) have been detected. Intensity of these molecular ions appears to be much less affected by matrix effects. We have successfully accomplished the compositional analysis with standard deviation better than 2 percent.

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