• Title/Summary/Keyword: Fiber shape

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Seam Puckering Behavior of Breathable Waterproof Fabrics with Various Finishing Methods (가공방법에 따른 투습방수직물의 심 퍼커링 거동)

  • Jeong, Won-Young;Han, Won-Hee;An, Seung-Kook
    • Proceedings of the Korean Fiber Society Conference
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    • 2003.04a
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    • pp.402-403
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    • 2003
  • Garment manufacture represents the final stage of processing a finished fabric. The main task of the garment manufacturer is to produce shell structures out of flat fabrics to match the shape of the human body, and the most acceptable means of joining textile materials for apparel use is by sewing. On the sewing process, the bottom layer is pushed forward by the feed-dog, but the presser foot tends to retard the passage of the top layer. Since the friction between the layers is low, is possible that the components will move out of phase and pucker. (omitted)

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Microscopic Observation of Kenaf by Optical and Scanning Electron Micrograph (Kenaf 구성 세포의 현미경적 관찰)

  • Yoon, Seung-Lak
    • Journal of Korea Technical Association of The Pulp and Paper Industry
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    • v.41 no.2
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    • pp.47-54
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    • 2009
  • Anatomical characteristics of kenaf were investigated in transverse, radial and tangential direction by optical and scanning electron micrograph. Kenaf was made up of bast fibers, wood fibers, vessels and parenchyma cells. Bast fibers were long slender cells with different types of pits. The shape of wood fibers were in various ways and pointed at the ends. The pits were observed on the surface of bast fibers. Kenafs were diffuse and radial porous. and composed of solitary pores and two or three radial pore multiples. Various types of vessels were observed. The pits showed alternate pitting and larger diameter than other cells. Parenchyma cells were rectangular or square with different shapes of pith parenchyma cells compared to conventional types of parenchyma cells in wood. The number of pith on the surfaces were small.

Study on the Defect Detectability in Carbon Fiber Reinforced Plastic Sheet by the Ultrasonic Immersed Reflector Plate Method. (Ultrasonic Immersed Reflector Plate Mechod를 이용한 박판형 CFRP 소재의 결함탐지능에 관한 연구)

  • Lee, Jae-Ok;Lee, Se-Kyung
    • Journal of the Korean Society for Nondestructive Testing
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    • v.6 no.1
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    • pp.23-30
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    • 1986
  • The optimumultrasonic test conditions for the thin carbon fiber reinforced plastic (CFRP) sheet were determined for the immersed reflector plate method. The effects of the water distance, the surface conditions of the specimen and transducer characteristics were studied. For a reliable test the water distance between the transducer and the front surface of the specimen should be determined when the beam profile of the transducer appears in the bell-shape. The detectability of the defect was improved as the effective beam width of the ultrasonic transducer became narrow. The transducer should be properly chosen considering to the surface condition of the test material as well as the size and type of the defect to be detected. It was possible to detect the flat bottom hole whose diameter is as small as about 500 micrometer.

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A study on the chucking alignment error analysis in coaxial grinding of ferrule (페룰 동축연삭시 척킹 오차 해석)

  • 김동길;김영태;이상조
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2002.05a
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    • pp.9-14
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    • 2002
  • Ferrule is widely used as fiber optic connecters. In fiber-optic communications, the shape accuracy such as coaxiality and cylindricity of ferrule affects insertion loss. When coaxial grinding of ferrule supported by two pin, pin alignment and chucking accuracy are very important. In this research, the kinematic behavior of the ferrule center is investigated in the case where cone-shaped center pins and round circle hales which make contact with each other near the edge of the holes, using homeogenous coordinate transformation and numerical analysis. The obtained results are as follows: The alignment errors between center pins alone do not affect the rotation accuracy of ferrule. The alignment errors between center holes cause a sinusoidal displacement of ferrule. And the maximum displacement of ferrule centers increase in proportion to the center pin angle in the case of a fixed alignment errors

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A Study on the Mechanical Properties of Floor Slab structures Using Fiber Reinforced Cement Composites (섬유보강 시멘트 복합체를 이용한 상판구조의 역학적 특성에 관한 연구)

  • 박승범;윤의식;차종훈
    • Proceedings of the Korea Concrete Institute Conference
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    • 1994.10a
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    • pp.343-349
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    • 1994
  • The purpose of this study is to investigate the mechanical properties of floor slab structures with high-strength and lightweight CFRC panel using fly ash, PAN-derived and Pitch-derived carbon fiber. As a result, the flexural strength of CFRC is remarkably increased by CF contents, but compressive strength of the CFRC is not so increased as flexural strength. The bulk specific gravity is influenced by FA contents more than by CF contents, The compressive strength and the flexural strength are increased by FA contests, but decreased the case of 30% of contents. In order to increasing the flexural-carrying capacity of floor slab structures, it is recommended that the shape of anchor for reinforcement is required type-C and the spacing of anchor is required below 60mm.

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An Experimental Study on Physical and Mechanical Properties of Steel Fiber Reinforced Concrete Containing Waste Glass (폐유리를 혼입한 강섬유보강 콘크리트의 물리ㆍ역학적 특성에 관한 실험적 연구)

  • 박승범;이봉춘;조광연;이택우
    • Proceedings of the Korea Concrete Institute Conference
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    • 2002.05a
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    • pp.903-908
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    • 2002
  • The production of waste glasses has been increased with the development of industry. The utilization of waste glass for concrete can cause the concrete to be cracked and to be weakened due to an expansion by alkali-silica reaction(ASR). When used the fibers with waste glass, there is an effect on reduction of expansion and strength loss due to ASR between the alkali in the cement paste and the silica in the waste glass. In this study, we conducted basic experimental research to analyze the possibilities of recycling of amber waste glass as fine aggregates for steel fiber reinforced concrete. Test results of fresh concrete. slump is decreased because grain shape is angular and air content is increased due to involving small size particles so much in waste glasses. Also. tensile and flexural strengths increased as the content of steel fibers increased. In conclusion, the content of waste glass below 40% is reasonable and usage of pertinent admixture is necessary to obtain workability or air content.

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Surface contouring using Electronic Speckle Pattern Interferometry (전자 스페클 패턴 간섭계를 이용한 형상 측정)

  • 김계성;유원재;강영준
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 1995.10a
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    • pp.397-401
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    • 1995
  • ESPI(Electronic Speckle Pattern Interfermetry) is an optical technique to measure surface deforamtion of engineering components and materials in industrial ares. This optical method is capable of providing full-field results with high spatial resolution, high speed and is the non-contact technique. One of important application aspects using electronic speckle pattern interferometry is to generate contours of a diffuse object in order to provide data for 3-D shape analysis and topography measurement. The contouring method by modified dual-beam speckle pattern interferometry is proposed. We introduce a shift of the illumination beams through optical fiber in order to obtain the contour fringe patterns. The speckle pattern correlation technique is suitable for providing measurement range from millimeters to several centimeters. The complete geometric analysis of the contoretical and experimental results are obtained.

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Optimization of a fiber optic probe for non-invasive blood glucose monitoring

  • Kang, Na-Roo;Baek, Ju-Hyun;Woo, Young-Ah;Lee, Hyun-Chul;Kim, Hyo-Jin
    • Proceedings of the PSK Conference
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    • 2002.10a
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    • pp.407.3-408
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    • 2002
  • A portable near infrared (NIR) system which was newly integrated by our lab has been used to develop a non-invasive blood glucose monitoring. The portable NIR system includes a tungsten halogen lamp, a photo diode array type-InGaAs detector, and specialized reflectance fiber optic probes. The shape of probes is composed of two parts. one for illumination into sample and the other for receiving the radiation from sample. Three kinds of probes with different distance between illumination and receiving part. such as 0.03. 0.1. and 0.5mm, were investigated for optimization. (omitted)

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Rapid Tooling for Resin Transfer Molding of Composites Part (복합재료 부품의 RTM 공정을 위한 쾌속금형의 제작)

  • Kim, S.K.
    • Transactions of Materials Processing
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    • v.15 no.6 s.87
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    • pp.436-440
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    • 2006
  • A rapid tooling (RT) method fur the resin transfer molding (RTM) have been investigated. We fabricated a curved I-beam to verify the method. After creating a three-dimensional CAD model of the beam we fabricated a prototype of the model using a rapid prototyping (RP) machine. A soft mold was made using the prototype by the conventional silicone mold technique. The procedure and method of mold fabrication is described. The mold was cut into several parts to allow easier placement of the fiber preform. We conducted the resin transfer molding process and manufactured a composite beam with the mold. The preform was built by stacking up eight layers of delicately cut carbon fabrics. The fabrics were properly stitched to maintain the shape while placement. The manufactured composites beam was inspected and found well-impregnated. The fiber volume ratio of the fabricated beam was 16.85%.

Effect of Concrete Strength on the Bond Strength of Glass Fiber Reinforced Polymer Bars (콘크리트 강도가 GFRP 복합재료 보강근의 부착강도에 미치는 영향)

  • Kim, Tae-Young;Park, Ji-Sun;Lee, Jung-Yoon;You, Young-Chan;Kim, Keung-Hwan
    • Proceedings of the Korea Concrete Institute Conference
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    • 2005.11a
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    • pp.189-192
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    • 2005
  • Glass fiber reinforced polymer (GFRP) bars gain increasingly more attention as a reinforcing option for concrete because of their corrosion resistance and non-magnetism. GFRP reinforcement for concrete does not have the same shape as steel reinforcement. Therefore, the bond performance of FRP bars, unlike that of steel, is dependent on their design, manufacture and mechanical properties. This paper studied the effect of high strength concrete on the bond strength of GFRP bars. Twenty-nine specimens having different compressive strength of concrete were tested in order to examine the bond behavior of GFRP bars.

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