• 제목/요약/키워드: monofilament

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폴리프로필렌 섬유보강 콘크리트의 파괴특성 연구 (Fracture Characteristics of Polypropylene Fiber Reinforced Concrete)

  • Shin-Won Paik
    • 한국안전학회지
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    • 제12권4호
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    • pp.230-240
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    • 1997
  • 본 연구에서는 폴리프로필렌 섬유보강 콘크리트의 파괴특성을 알아보기 위해 Monofilament 섬유와 Fibrillated 섬유의 두 종류 폴리프로필렌 섬유를 선택하여 10$\times$10$\times$50 cm 보 시편을 만들었는데, 이때 사용된 두 종류의 섬유 길이는 19 mm이고, 섬유 혼입량은 0%, 1%, 2%, 3%로 하였으며, 초기균열 깊이의 영향을 알아보기 위해 초기 균열길이를 각 섬유 혼입량에 따라 1.5cm, 3.0cm, 4.5cm로 하여 실험을 수행하였다. 또한, 본 연구에서는 폴리프로필렌 섬유보강 콘크리트의 파괴특성을 규명하기 위해 보 시편에 대한 4 점 하중 휨시험을 통해 하중-하중점 변위 곡선을 각 시편에 대해 측정하였고, 이때 COD 게이지를 이용하여 하중-CMOD 곡선도 측정할 수 있었다. 이러한 실험결과를 통해, 섬유혼입량과 초기 균열 깊이에 따른 압축강도, 휨강도 및 휨인성, 응력확대계수, 파괴에너지 등이 규명되었다. 이러한 결과에 대한 분석으로부터 Fibrillated 폴리프로필렌 섬유가 Monofilament 섬유보다 연성 효과가 큰 것을 알 수 있었으며, 특히 하중-CMOD 곡선으로부터 계산되는 파괴에너지인 Jc가 믿을만한 파괴특성 인자임을 알 수 있었다.

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수중 침지식 생분해성 PBSAT 그물 열처리기 개발과 성능 분석 (Development of the submerged heat treatment machine for PBSAT(polybutylene succinate adipate-co-terephthalate) monofilament nets and its efficiency)

  • 박성욱;김성훈;임지현;최혜선
    • 수산해양기술연구
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    • 제51권1호
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    • pp.94-101
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    • 2015
  • The heat treatment machine based on immersion was developed to reduce temperature difference during netting process and appraised it performance compared current heat treatment machine using high pressure. It was also reviewed the optimum heat treatment procedures for PBSAT monofilament net in accordance with the immersion time and temperature. The procedure was based on physical measurement such as breaking load, elongation and angle of the mesh for PBSAT monofilament. The water temperature gap of the treatment machine based on immersion was less than $1^{\circ}C$. and the energy consumption was also increased in high temperature condition. It was identified that the optimum temperature was $75^{\circ}C$ and its optimum processing time was between 15 minutes and 20 minutes to get qualified physical properties.

Biodegradable sheath-core biphasic monofilament braided stent for bio-functional treatment of esophageal strictures

  • Han, Cheol-Min;Lih, Eugene;Choi, Seul-Ki;Bedair, Tarek M.;Lee, Young-Jae;Park, Wooram;Han, Dong Keun;Son, Jun Sik;Joung, Yoon Ki
    • Journal of Industrial and Engineering Chemistry
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    • 제67권
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    • pp.396-406
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    • 2018
  • In this study, a polydioxanone (PDO) and poly(L-lactic acid) (PLLA) sheath-core biphasic monofilament was designed to develop an esophageal stent with improved mechanical properties and controlled biodegradability. The radial force of PDO/PLLA sheath-core stent was 10.24 N, while that of PDO stent was 5.64 N. Deteriorations of tensile strength, elastic modulus and elongation during degradation test were also delayed on PDO/PLLA group. Hyaluronic acid-dopamine conjugate and $BaSO_4/PDO$ conjugate coating layers provided improved tissue adhesion strength and reasonable X-ray contrast, respectively. Taken all together, the sheath-core filaments with tissue adhesive and radiopaque properties will be useful in designing esophageal stents.

연평어장에서 생분해성 꽃게 삼중자망의 어획성능 (Catching efficiency of biodegradable trammel net for swimming crab (Portunus trituberculatus) in the Yeonpyeong fishing ground of Korea)

  • 김인옥;이건호;조삼광;차봉진;손병규
    • 수산해양기술연구
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    • 제48권4호
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    • pp.322-336
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    • 2012
  • To study the catching efficiency of biodegradable trammel net for swimming crab (Portunus trituberculatus), three types (biodegradable, monofilament and multifilament) of trammel nets were used in the field test, and the tests were carried out 16 times with two different mesh sizes (105mm and 160mm) in the Yeonpyeong fishing ground of Korea, 2009~2011. The catching efficiency of three type nets was analyzed by catch in number, catch in weight and average weight per individual of small and large size swimming crab by net types and mesh sizes. Statistical T-test was also carried out to verify the efficiency between the three types of nets. The results are as follows. The catch in number of swimming crab was 24,667 and formed about 81.0% of total catch. Of all swimming crab catch, small swimming crabs with less than 64mm in carapace length which is a prohibited landing size by law formed 48.1%, larger swimming crabs with more than 64mm in carapace length which is a landing size formed 51.9%. In 105mm mesh size trammel net test, the catch share in number of small size swimming crab by biodegradable trammel net was 47.5% in comparison with multifilament trammel net and 74.2% in comparison with monofilament trammel net, so biodegradable trammel net has more protective effects on small size swimming crab than other types of trammel nets. The protective effects for small size swimming crab by biodegradable trammel net was 25.8~52.5% in comparison with other types of trammel nets. The catch share in weight of large size swimming crab by biodegradable trammel net was 98.3% in comparison with multifilament trammel net and 92.3% in comparison with monofilament trammel net, so biodegradable trammel net has a similar catch efficiency to multifilament trammel net. The results of 160mm mesh size trammel net test have shown similar results of 105mm mesh size trammel net test. This study shows that biodegradable trammel net is a more useful fishing gear than multifilament and monofilament trammel net because biodegradable trammel net has lower catch rate than other types of nets in small size swimming crab and similar catch rate than multifilament trammel net which is a well used net by fishermen.

Effect of fiber content on flexural properties of fishnet/GFRP hybrid composites

  • Raj, F. Michael;Nagarajan, V.A.;Elsi, S. Sahaya;Jayaram, R.S.
    • Steel and Composite Structures
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    • 제22권1호
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    • pp.13-24
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    • 2016
  • In the present paper, glass fibers are substituted partially with monofilament fishnet and polyester matrix for making the composites. The composite specimens were prepared in accordance with ASTM for analyzing the flexural strength and dynamic mechanical properties. Furthermore, machinability revealed the interaction of glass fiber and partial substituted monofilament fishnet fiber with the matrix. Fiber pullouts on the fractured specimen during the physical testing of the composites are also investigated by COSLAB microscope. The results reveal that the fishnet based composites have appreciably higher flexural properties. Furthermore, the glass fiber, woven roving and fishnet composite has more storage modulus and significant mechanical damping. The composite specimens were fabricated by hand lay-up method. Hence, these composites are the possible applications to develop the value added products. The results of this study are presented.

Monofilament Polypropylene사를 이용한 단속단층 식도문합술 (Interrupted Single-layer Suture Technique in Esophageal Anastomosis Using Monofilament Polypropylene Suture)

  • 성시찬;편승환
    • Journal of Chest Surgery
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    • 제31권7호
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    • pp.711-717
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    • 1998
  • 배경: 식도 문합술은 여러가지 문합방법과 문합재료를 사용해오고 있지만 문합부 누출과 협착이 다른 장문합에 비해 빈번하고 발생하면 중한 결과를 초래한다. 최근 저자들은 식도문합술 거의 대부분에서 polypropylene사를 이용한 단속단층 문합술을 시행하고 있다. 대상 및 방법: 이에 본 동아대학교병원 흉부외과에서는 1990년 4월부터 1996년 12월까지 시행한 식도문합술 90례의 임상결과를 분석하여 이 문합방법의 효용성을 알아 보기위해 이 연구를 시행하였다. 문합부 누출은 모두 5례(5.6%)에서 발생하였고 이 중 1례가 사망하였다. 결과: 문합부 협착은 수술 생존자를 대상으로 조사하였는데 모두 15례(17.4%)에서 발생하였다. 이 협착은 식도-위 문합술에서 가장 높은 빈도(22%)로 나타났고, 식도-대장문합술에서 가장 낮은 빈도(5%)로 나타났다. 이러한 결과는 다른 여러학자들의 자동 문합기에 의한 문합방법을 포함한 다른 문합방법들의 결과들과 비교할만한 결과였다. 결론: 저자들은 식도문합에 있어 이 문합방법은 식도폐쇄증 교정을 포함한 여러 식도문합에서 만족스러운 결과로 계속 사용되어 질 수 있으리라고 생각된다.

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참조기 유자망어업에 있어서 그물실의 굵기 변화에 따른 어획성능 특성 (Characteristics on the fishing performance of a drift net for yellow croaker (Larimichthys polyactis) in accordance with the thickness of a net twine)

  • 김성훈;박성욱;이경훈;임지현
    • 수산해양기술연구
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    • 제49권3호
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    • pp.218-226
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    • 2013
  • The objective of this study is to estimate the optimal net twine thickness of drift net for yellow croaker. The filed experiments of the fishing performance were conducted with three kinds of drift net with different monofilament diameters (No.3=0.284mm, No.4=0.330mm, No.5=0.370mm) the total eight times in the southwest coastal sea of Korea. And the physical properties tests on the monofilaments of experimental net were carried out to estimated breaking load and softness in dry and wet conditions, respectively. From the results, the No.3 mono. was the strongest break load per unit area in dry and wet conditions. And the softness showed that the No. 3 mono. was the most soft than another experimental monofilaments. The fishing performance was; the No. 3 drift net showed the most catches. Conversely, the catches of No. 4 and No. 5 drift net showed the half on the catches of No. 3 drift net. Consequently, the diameter of monofilament in the drift net for yellow croaker should carefully choose to consider the economic sides such as the amount of catches and the cost of catches.