• 제목/요약/키워드: shed

검색결과 1,087건 처리시간 0.023초

직기 특성이 PET직물 물성에 미치는 영향(I) (Effects of Weaving Machine Characteristics on the Physical Properties of PET Fabrics (I))

  • 김승진;손준혁;강지만;박명환
    • 한국염색가공학회지
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    • 제16권4호
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    • pp.26-35
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    • 2004
  • This study surveys the tension differences between Korean domestic and foreign looms and analyses fabric mechanical properties due to warp and weft tension differences using KES-FB system. Paper is divided by two parts. In this 1st paper, fabric is designed as 5 harness satin weave using 75d/36f warp and 100d/192f weft polyester filaments, and is woven by $Omega^\circledR$ rapier loom by Textec Co.Ltd and Picanol$-GTX^\circledR$ rapier loom by Picanol Co.Ltd respectively. These grey fabrics are processed on the same dyeing and finishing processes. Weavability is also analysed by measuring warp tension variation according to the warp position, the relationship between shed amount and the warp tension on one fixed heald frame is surveyed, and the relationship between end breaks and warp and weft tensions is also discussed.

진동 유동장에서 유동공진에 의한 실린더 후류의 와류 특성 변화 (Change of Vortex Dynamics in the Cylinder Wake by the Lock-on to Oscillatory Incident Flow)

  • 김원태;성재용;유정열
    • 대한기계학회논문집B
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    • 제27권11호
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    • pp.1645-1654
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    • 2003
  • When vortex shedding is locked-on to a single frequency oscillatory flow, the variations of vortex dynamics are investigated using a time-resolved PIV system. Wake regions of recirculation and vortex formation, dynamic behavior of the shed vortices and the Reynolds stress fields are measured in the wake-transition regime at the Reynolds number 360. In the lock-on state, reduction of the wake region occurs and flow energy distributed downstream moves upstream being concentrated near the cylinder base. To observe the dynamic behavior of the shed vortices, the trajectory of the vortex center extended to the inside of the wake bubble is considered, which describes well the formation and evolution processes. The Reynolds stresses and their contributions to overall force balance on the wake bubble manifest the increase of the drag force by the lock-on.

Full-scale investigation of wind-induced vibrations of a mast-arm traffic signal structure

  • Riedman, Michelle;Sinh, Hung Nguyen;Letchford, Christopher;O'Rourke, Michael
    • Wind and Structures
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    • 제20권3호
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    • pp.405-422
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    • 2015
  • In previous model- and full-scale studies, high-amplitude vertical vibrations of mast-arm traffic signal structures have been shown to be due to vortex shedding, a phenomenon in which alternatingly shed, low-pressure vortices induce oscillating forces onto the mast-arm causing a cross-wind response. When the frequency of vortices being shed from the mast-arm corresponds to the natural frequency of the structure, a resonant condition is created causing long-lasting, high-amplitude vibrations which may lead to the fatigue failure of these structures. Turbulence in the approach flow is known to affect the cohesiveness of vortex shedding. Results from this full-scale investigation indicate that the surrounding terrain conditions, which affect the turbulence intensity of the wind, greatly influence the likelihood of occurrence of long-lasting, high-amplitude vibrations and also impact whether reduced service life due to fatigue is likely to be of concern.

프로젝타일과 에어제트 직기특성이 의류용 모직물 물성에 미치는 영향(I) - 장력특성과 직기 메커니즘 - (Effect of the Projectile and the Air-jet Weaving Machine Characteristics on the Physical Properties of Worsted Fabrics for Garment(I) -Tension Characteristics & Loom Mechanism-)

  • 김승진;정기진
    • 한국의류산업학회지
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    • 제7권1호
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    • pp.101-105
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    • 2005
  • This study surveys the warp and weft tension differences between projectile and air-jet looms and analyses the mechanical properties of worsted fabrics for garment with relation of these loom characteristics using KES-FB system. The paper is divided by two parts. In the 1st paper, the worsted fabric is woven as 5 harness satin weave using 1/40 Nm sirofil worsted warp yarn and 1/30 Nm worsted weft yarn by projectile(Sulzer) and air-jet looms(Picanol PAT and OMNI), respectively. The weavability is also analysed by measuring warp tension variation according to the warp position and weft tension of 3 kinds of looms. The relationship between shed amount and the warp tension is surveyed, and the relationship between end breaks and warp and weft tensions is also discussed.

래피어 직기 특성이 의류용 모직물 물성에 미치는 영향(I) - 장력특성과 직기 매카니즘 - (Effects of Rapier Weaving Machine Characteristics on the Physical Properties of Worsted Fabrics for Garment (I) - Tension Characteristics & Loom Mechanism -)

  • 김승진;강지만
    • 한국의류산업학회지
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    • 제6권6호
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    • pp.765-771
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    • 2004
  • This study surveys the warp and weft tension differences among 3 types of rapier looms and analyses the mechanical properties of worsted fabrics for garment with relation of these looms characteristics using KES-FB system. Raper is divided by two parts. In the 1st paper, the worsted fabric is woven as 5 harness satin weave using 1/40 Nm sirofil worsted warp yam and 1/30 Nm worsted weft yam by rapier looms such as FAST-R, THEMA-11-E and PICANOL-GTX respectively. The weavability is also analysed by measuring warp tension variation according to the warp position and weft tension of 3 kinds of looms. The relationship between shed amount and the warp tension is surveyed, and the relationship between end breaks and warp and weft tensions is also discussed.

전력선 벤드 장력 작용에 대한 전주의 영향 (Protect Measures and Impact of Electric Pole for Abnormal Tension of Messenger Wire)

  • 조현섭;김영조;김성운
    • 한국산학기술학회:학술대회논문집
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    • 한국산학기술학회 2006년도 춘계학술발표논문집
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    • pp.302-306
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    • 2006
  • In this study, we analyzed the influence of electrical pole by FEM(Finite Element Method) and developed protective system by designing and interpreting protective system for electrical pole when abnormal strength worked on messenger wire. Protective system did not shed messenger wire under wind pressure and discontent load but did assign a part to preventing rupture of electrical pole through automatically shed messenger wire over fixed strength. Structure of protective system analysis by FEM and prove property by measuring tensile strength for practical product.

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보오텍스 분포법(分布法)에 의한 회전체(回轉體)의 유체동력학적(流體動力學的) 힘과 모우멘트의 추정(推定) (Prediction of Hydrodynamic Forces and Moments Acting on a Body of Revolution by the Method of Surface Vortex Distribution)

  • 양승일;이창섭;강창구
    • 대한조선학회지
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    • 제20권1호
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    • pp.35-46
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    • 1983
  • The hydrodynamic lift and moment acting on the bodies of revolution with pointed-end were calculated by the surface discrete vortex method. It was found, by direct computation, that the lift normal to the on-coming flow can be generated by introducing the shed-vortex to the unless otherwise purely potential model. The value of the destabilizing moment, which is called Munk moment, is reduced by the shed-vortex model, resulting in better agreement with the existing experimental values.

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조가선 이상 장력 작용에 대한 전주의 영향 및 보호 대책 연구 (A Study on the Protect Measures and Impact of Electric Pole for Abnormal Tension of Messenger Wire)

  • 오훈
    • 조명전기설비학회논문지
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    • 제20권3호
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    • pp.78-83
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    • 2006
  • 본 연구에서는 통신선 가설 보조 기구인 조가선에 이상 장력이 작용하였을 때 전주의 영향을 유한 요소 해석을 통하여 전주 보호 기구를 설계 해석하여 보호시스템을 개발하였다. 보호시스템은 일반하중 또는 풍압과 일반적인 불평형 하중에서는 조가선이 탈락되지 않고 일정강도 이상이 가해지면 조가선이 자동 탈락되어 전주의 절손 방지 역할을 한다. 이러한 보호시스템의 구조는 유한 요소 해석을 통하여 해석되어졌고, 실제 제품에 대한 인장강도를 측정함으로써 성능을 입증하였다.

종양세포 표면항원에 대한 분자면역학적 연구(II) 백혈병세포의 발생과 세포분화에 관한 연구 (Immunological Studies on the Surface Antigens of Tumor Cell (II) Introduction to Immunological Studies on the Development and Cell Differentiation of the Leukemia Cell)

  • 김한도;김정락박병채
    • 한국동물학회지
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    • 제34권4호
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    • pp.469-478
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    • 1991
  • The CALLA on the surface of leukemic cell lines, recognized by our monoclonal antibody. KP-22(IgG1, K) was one of cell surface glycoproteins having moi. wt. of approximately 100,000 dalton, and could be shed in spent medium or endocytosed when binding the cognate antidoby, KP-22. In the presence of cognate antibodies, 60% of CALLAS recogniEed by KP-22 MAs were modulated and cleared from the cell surface during 24 hrs, and approximaetely 35% of them was endocytosed and 25%, was shed in spent medium. The reappearance of the membrane CALLA after modulation by the KP-22 required at least 6 hours and supposed to be newly synthesized molecules.

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