• 제목/요약/키워드: Electric-field dependence

검색결과 179건 처리시간 0.027초

전도성 모델에 의한 키토산 현탁액의 유변학적 특성 연구 (Electrorheology of Chitosan Suspension by Conduction Models)

  • 최웅수;안병길;이상순;권오관
    • Tribology and Lubricants
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    • 제14권4호
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    • pp.95-99
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    • 1998
  • The electrorheological (ER) behavior of chitosan suspension in the silicone oil was investigated. Chitosan suspension showed a typical ER response, Bingham flow behavior upon application of an electric field due to the polarizability of the branched amino group of the chitosan particles. The shear yield stress exhibited a linear dependence on the volume fraction of particles and the squared electric field. On the basis of the experimental results, chitosan suspension has been correlated with the conduction models for ER response and found to be an ER fluid.

Electrorheological Properties of Chitin and Chitosan Suspensions

  • 최웅수
    • KSTLE International Journal
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    • 제6권1호
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    • pp.8-12
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    • 2005
  • The electrorheological properties pertaining to the electrorheological (ER) bebaviour of chitin and chitosan suspensions in silicone oil were investigated. Chitosan suspension showed a typical ER response (Bingham flow behavior) upon application of an electric field, while chitin suspension acted as a Newtonian fluid. The difference in behaior results from the difference in the conductivity of the chitin and chitosan particles, even though they have a similar chemical structure. The shear stress for the chitosan suspension exhibited a linear dependence on the volume fraction of particles and a 1.18 power of the electric field. The experimental results for the chitosan suspension correlated with the conduction model for ER response.

유체법을 이용한 유사스파크 방전의 기동 특성 해석 (Ignition Characteristics Analysis of Pseudospark Discharge using Fluid Method)

  • 심재학;주흥진;고광철;강형부
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 1997년도 춘계학술대회 논문집
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    • pp.95-98
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    • 1997
  • Theoritical predictions are given of the time dependence of charged particle densities and electric field in a pseudospark discharge. Our medel is based on a numerical solution of the continuity equation for electrons and positive ions and coupled with Poisson's equation for the electric field. From numerical results, we can identify phisical mechanisms that lead to the rapid rise in current in the onset of a pseudospark discharge.

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수정된 수평 전개 모델을 이용한 SC-PMOSFET의 기판 전류와 게이트 전류의 해석적 모델 (An Analytical Models for Substrate Current and Gate Current Using Modified Lateral Electric Field Model for Surface-Channel PMOSFET's)

  • 양광선;박종태;김봉렬
    • 전자공학회논문지A
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    • 제31A권1호
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    • pp.48-53
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    • 1994
  • In this paper, we present the analytical models for substrate current and gate current of stressed SC-PMOSFET using the change of the lateral electric field distribution due to the trapped electron. Calculated Isub and Ig of stressed SC-PMOSFET agree with experimental data. Our model can be very useful explaining the logarithmic time dependence of Isub and Ig. and also the trapped electron distribution.

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Electrorheology of Hollow Polyaniline Pimelate Suspension by Conduction Model

  • Choi Ung-Su
    • KSTLE International Journal
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    • 제7권1호
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    • pp.1-4
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    • 2006
  • The electro rheological behavior of the hollow polyaniline pimelate suspension in silicone oil was investigated. Hollow polyaniline pimelate suspension showed a typical ER response (Bingham flow behavior) upon application of an electric field. The shear stress for the suspension exhibited the dependence with a factor equals to 0.84 power on the electric field. The experimental results for the hollow polyaniline pimelate suspension correlated with the conduction models of Tang et al., and this suspension behaved as an ER fluid.

전도성 모델에 의한 인산에스테르셀룰로오즈 현탁액의 전기유변학적 특성 연구 (Electrorheological Properties of Cellulose Phosphate Ester Suspension by Conduction Models)

  • 최웅수;고영건;박용성;권오관
    • Tribology and Lubricants
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    • 제17권2호
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    • pp.124-129
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    • 2001
  • The electrical and rheological behaviors of the cellulose phosphate ester suspension in the silicone oil were investigated. Cellulose phosphate ester suspension showed a typical ER response (Bingham flow behavior) upon application of an electric field. The shear stress for the cellulose phosphate ester suspension exhibited a linear dependence on the volume fraction of particles and a square power of the electric field. On the basis of the experimental results, cellulose phosphate ester suspension correlated with the conduction model of Tang et al, and found to be an ER fluid.

외부자계 영향에 따른 HTS 선재의 직$\cdot$교류 통전 특성 (DC and AC current transport characteristics of HTS tapes with external magnetic field)

  • 임성우;최용선;최효상;황시돌;정영호
    • 한국초전도저온공학회:학술대회논문집
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    • 한국초전도저온공학회 2003년도 학술대회 논문집
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    • pp.15-18
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    • 2003
  • HTS(High Temperature Superconductor) tapes have dependence on critical characteristics such as electric, magnetic field and temperature. In order to confirm these effects, we examined the current transport characteristics of HTS tapes. First, after being fed DC and AC, the dependence of HTS tapes of 10cm on external magnetic field was investigated. On centeral region of HTS tape, about 1cm, external magnetic field was applied. Second, after applying DC of 50A to HTS tapes, we applied time variable magnetic field about 100mT and investigated the quench characteristics. Finally, AC, which is about 10 times of I$_{c}$, was applied to HTS tapes and over current characteristics were investigated. The data acquired in this study will be used as a source for the study of HTS cable conductor which is supposed to carry on.n.

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제2고조파발생을 이용한 LiNbO$_3$의 중요 광굴절상수측정 (Determination of photorefrative constants in LiNbO$_3$ using second harmonic generation)

  • 김봉기;이범구
    • 한국광학회지
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    • 제12권3호
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    • pp.230-234
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    • 2001
  • 반전대칭이 없는 광굴절결정에 있어 위상접합이 만족되지 않은 상태에서 발생된 제2고조파의 세기가 외부전기장에 의존한다는 사실을 이용하여 광굴적결정의 광굴절율 변형현상에 관한 중요상수를 측정할 수 있는 방법을 개발하였다. 마커무늬의 전기장의존도에 관한 근사식을 구하였고 이를 이용하여 제2고조파의 세기변화로부터 공간전하장의 크기를 측정할 수있었다. 실험적으로 congruent $LiNbO_3$에 빛을 두가지 다른 세기로 비추어 유도되는 공간저하장의 시간의존성을 조사하였고 측정결과를 근사식과 비교분석하여 $LiNbO_3$의 광기전력상수, 암전도상수 및 광전도상수를 결정할 수 있었다.

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아민화 폴리아크로니트릴 유도체 현탁액의 전기유변학적 특성 (Electrorheological Properties of Aminated Polyacrylonitrile Susupension)

  • 최웅수;김충현
    • Tribology and Lubricants
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    • 제25권3호
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    • pp.176-181
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    • 2009
  • Aminated polyacrylonitrile as the new organic disperse phases of the anhydrous ER fluid has been synthesized and ER effect of the suspension composed of aminated polyacrylonitrile in silicone oil investigated. The suspension showed a typical ER response (Bingham flow behavior) upon application of an electric field. The shear stress for the suspension exhibited the dependence with a factor equals to 1.6 power on theelectric field. The current density and the conductivity of the of aminated polyacrylonitrile suspension increase with the electric field intensity and moreover the conductivity of the suspension is about 8 order of magnitude higher than that of the silicone oil. On the basis of the the results, aminated polyacrylonitrile suspension showed the ER flow behavior upon application of the electric field due to the polarizability of the branched amine polar group of the aminated polyacrylonitrile particles.

외부 자계 인가에 따른 고온초전도 케이블 도체의 ?치 특성 (Influence of external magnetic field on HTS cable conductor)

  • Seong Woo Yim;Si Dole Hwang;Je Myoung Oh;Byung Sung Han
    • 한국초전도저온공학회:학술대회논문집
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    • 한국초전도저온공학회 2003년도 추계학술대회 논문집
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    • pp.284-287
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    • 2003
  • Quench characteristics of HTS cable conductor due to external magnetic field were investigated. Firstly, the influence of critical characteristics of HTS tape on locally applied magnetic field was examined. Secondly, critical current of HTS tapes, which are wound on surface of former, were measured respectively, before the experiment for quench characteristics, Finally, 50mT and 100mT were applied to HTS cable conductor and quench characteristics were investigated through V-I curves. As the results, same as the result of HTS tape, HTS cable conductor showed strong dependence on external magnetic field with direction and magnitude.

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