• 제목/요약/키워드: Confining Effect

검색결과 287건 처리시간 0.023초

The fluctuation and the rigidity study of F-actin filaments in a confined space

  • Park, Myung-Chul;Youli Li;Cyrus R. Safinya;Kim, Mahn-Won
    • 한국생물물리학회:학술대회논문집
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    • 한국생물물리학회 2003년도 정기총회 및 학술발표회
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    • pp.67-67
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    • 2003
  • Filamentous actin (F-actin) is a two stranded long helix that performs structural function in eukaryotic cells. F-actin had been assembled from Alexa-labeled G-actin and had been confined in microchannel. The fluctuation of single filaments was observed by fluorescence optical microscopy. We measured Tangent-tangent Correlation Function G(s) (where s is the distance along the contour of the chain), which tells us the confining wall effect of wormlike semi-flexible polymers as well as the flexural rigidity, such as persistence length.

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강관 내무보강 중공교각의 연성도 평가 (Ducti1ity, Evaluation of Circular Reinforced Concrete Piers with an Internal Steel Tube)

  • 강영종;최진유;김도연;한택희
    • 한국철도학회:학술대회논문집
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    • 한국철도학회 2001년도 춘계학술대회 논문집
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    • pp.241-248
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    • 2001
  • The ductility of circular hollow reinforced concrete columns with one layer of longitudinal and spiral reinforcement placed near the outside face of the section and the steel tube placed on the inside face of the section is investigated. Such hollow sections are confined through the wall thickness since the steel tube is placed. The results of analytical moment-curvature analyses for such hollow sections are compared with those for the circular section with the sane diameter. In this study, moment-curvature analyses are conducted with Mandel's confined concrete stress-strain relationship in which the effect of confinement is to increase the compression strength and ultimate strain of concrete. The moment-curvature analyses confirmed that the ductility is primarily influenced on the ultimate strain. The variables influenced on the ultimate strain is the ratio and yield strength of confining reinforcement and the compression strength for confined concrete. From this ultimate strain - the transverse reinforcement ratio relationship, the transverse reinforcement ratio for circular hollow reinforced columns with confinement is proposed. The proposed transverse reinforcement ratio is confirmed by experimental results.

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각형강관을 사용한 고강도 콘크리트 전단벽체에 대한 실험적 연구 (An Experimental Study on the High-Strength Concrete Shear Wall using Rectangular Steel Tubes)

  • 최기봉;조순호;김명준;오종환
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 1997년도 봄 학술발표회 논문집
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    • pp.460-467
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    • 1997
  • Compared to normal-strength concrete, high-strength concrete has the lower lateral expansion capacity caused by the higher elastic modulus and the lower internal crack characteristic. Therefore, the effect of the lateral confining action of hoops appears slowly and also in inefficient Nevertheless. it has been reported that the strength and deformation capacity of high-strength concrete is improved by well-distributed hoops. Due to that argument, this investigation has been compared and analyzed by the experimental works on the deformation capacity and the confinement mechanism of high-strength concrete shear wall of the high-rise building reinforced by rectangular steel tubes and rectangular hoops at both edges of the shear wall.

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부모멘트를 받는 프리스트레스트 합성형교의 휨 거동 (Flexural Behaviors of Prestressed Composite Girder Bridges subjected to Negative Flexural Moment)

  • 강병수;주영태;성원진;신동훈;이용학
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 2005년도 봄학술 발표회 논문집(I)
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    • pp.419-422
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    • 2005
  • Prestressed composite girder bridges with concrete infilled steel tube at negative flexural moment region takes the advantages provided due to the interactive reaction in the steel tube and concrete interface layer, enhancing local buckling resistance and the concrete strength provided by the lateral confining effect of concrete. Two beams were tested to examine ultimate behaviors of prestressed composite girder bridges subjected to negative flexural moment. The experimental observations of the Prestressed composite girder bridges subjected to positive flexural moment are investigated and compared to the numerical results obtained by sectional analysis method, and 1-D. and 3-D. finite element analysis methods.

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대규모 굴착공사에 따른 지중연속벽체의 변형특성(I) -계측 및 실험- (Deformation Characteristics of Diaphragm Wall Induced by Deep Excavation(I) -Instrumentation and Experiments-)

  • 김동수;이병철;김동준;양구승
    • 한국지반공학회논문집
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    • 제17권4호
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    • pp.93-105
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    • 2001
  • 해성토층(풍화토 및 모래질 충적토가 암반 위에 쌓인) 위에 준설매립된 수도권 해안매립지역에서 원형의 대심도 굴착공사로 인하여 발생하는 지중연속벽의 수평변위에 대한 현장계측을 중심으로 연구를 수행하였다. 현장측정으로는 지중연속벽의 8방향에서 벽체수평변위와 철근응력, 토압, 간극수압 등이 측정되었고, 정확한 측정결과를 얻기 위하여 합리적인 해석 및 보정방법이 연구되었다. 현장측정결과 굴착시공단계에 따라서 벽체수평변위가 증가하였으며, 일정깊이에 존재하는 점토층을 굴착함으로써 간극수압의 급격한 변화가 측정되었다. 한편, 굴착전후의 구속압감소에 따른 지반물성치의 변화를 정리하였다. 굴착전후의 탄성계수는 일정깊이까지 상당한 정도로 감소됨을 알 수 있었고 굴착전후 여러 가지 시험방법에 따른 탄성계수의 차이들을 비교하였다.

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대규모 굴착공사에 따른 지중연속벽체의 변형특성(II) -수치해석- (Deformation Characteristics of Diaphragm Wall Induced by Deep Excavation(II) -Numerical Analysis-)

  • 김동준;이병철;김동수;양구승
    • 한국지반공학회논문집
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    • 제17권4호
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    • pp.107-115
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    • 2001
  • 해성토층 위에 준설매립된 수도권 해안매립지역에서 원형의 대심도 굴착공사로 인하여 발생하는 지중연속벽의 수평변위를 예측하기 위하여 수치해석을 수행하였고, 이러한 수치해석결과와 현장측정값을 비교하여 각각의 수치해석방법의 적용성을 평가하였다. 수치해석법으로는 지반반력해석, 선형 유한요소법 그리고 비선형 유한요소법이 수행되었다. 각각의 방법들에서는 미소변형률에서의 지반거동특성인 비선형성과 굴착으로 인한 구속압감소효과를 고려한 경우와 고려하지 않은 경우에 대하여 수치해석을 수행하여 각각 그 결과들을 비교.분석하였다. 이러한 분석결과 미소변형률에서의 비선형성과 굴착으로 인한 구속압감소 효과를 고려한 비선형 유한요소해석법이 가장 정확하게 수평변위를 예측할 수 있는 방법임을 알 수 있었다.

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샌드위치식 강-콘크리트 복합구조체의 매개변수 및 거동특성 연구 (A Study on Parameter and Behavior for Composite Steel-Concrete Structure of Sandwich System)

  • 정연주;정광희;이필승;박성수;황일선
    • 한국전산구조공학회:학술대회논문집
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    • 한국전산구조공학회 2000년도 가을 학술발표회논문집
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    • pp.75-82
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    • 2000
  • A huge offshore structures such as immersed tunnel, ice-resisting wall are continuously subjected to large force from water pressure, wave action and impact loads. Composite steel-concrete structure of sandwich system has profitable advantages for a huge offshore structures. This composite structures should exhibit a high degree of strength and ductility, because of concrete confining effect and the property of steel plate. Therefore, it endures large deformation and absorbs a great deal of energy until failure. In this study, nonlinear analysis for composite steel-concrete structure of sandwich system was carried out, and certify the effects of various parameters, elastic·plastic behavior characteristic, load-carrying and failure mechanism.

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Behavior of geotextile reinforced flyash + clay-mix by laboratory evaluation

  • Vashi, Jigisha M.;Desai, Atul K.;Solanki, Chandresh H.
    • Geomechanics and Engineering
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    • 제5권4호
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    • pp.331-342
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    • 2013
  • The major factors that control the performance of reinforced soil structures is the interaction between the soil and the reinforcement. Thus it is necessary to obtain the accurate bond parameters to be used in the design of these structures. To evaluate the behavior of flyash + clay soil reinforced with a woven geotextile, 36 Unconsolidated-Undrained (UU) and 12 reinforced Consolidated-Undrainrained (CU) triaxial compression tests were conducted. The moisture content of soil during remolding, confining pressures and arrangement of geotextile layers were all varied so that the behavior of the sample could be examined. The stress strain patterns, drainage, modulus of deformation, effect of confinement pressures, effects of moisture content have been evaluated. The impact of moisture content in flyash + clay backfills on critical shear parameters was also studied to recommend placement moisture for compaction to MDD. The results indicate that geotextile reinforced flyash + clay backfill might be a viable alternative in reinforced soil structures if good-quality granular backfill material is not readily available.

안산지역 해함점토의 크리프 정수에 관한 연구 (A Study on the Creep Parameters of Ansan Marine Clay)

  • 정형식;안상로
    • 한국지반공학회지:지반
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    • 제9권4호
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    • pp.93-102
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    • 1993
  • 연약 지반위에 축조된 토질 구조물은 제체의 자중으로 인하여 오랜 기간 동안 침하가 계속되는데 이는 시간표존적 거동인 압밀과 크리프(creep)가 동시에 작용하여 발생된다. 본 연구에서는 안산의 해성점토에 대하여 크리프거동 해석에서 필요한 정수를 구하고 수치해석시 중요시되고 있는 구속응력과 응력수준에 따른 크리프정수의 영향 특성에 대하여 연구하였다. 그 결과 탄성계수 E1과 크리프정수 n는 적용응력 수준에 영향을 받는 것으로 나타나 응력수준에 따른 크리프정수 결정식을 제시하였다.

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복합 유체-입자(몬테칼로)법을 이용한 유사스파크 방전의 기동 특성 해석 (Ignition Characteristics Analysis of Pseudospark Discharge using Hybrid Fluid-Particle(Monte Carlo) Method)

  • 주흥진;심재학;강형부
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 1997년도 추계학술대회 논문집
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    • pp.270-274
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    • 1997
  • The numerical model that can describe the ignition of the pseudospark discharge using hybrid fluid-particle method has been developed. The evolution process of the discharge has been divided into four phases along the potential distribution. After the plasma enters in the hollow cathode, the confining effect which is one of hollow cathode properties occurs and the electron current on anode rises rapidly. As the plasma expands successively, the sheath contracts and as the electric field in the sheath increases, the field-enhanced thermionic emission(Schottky emission) occurs. From numerical results, the physical mechanism that causes the rapid current rise in the ignition of the pseudospark discharge could be identified.

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