• 제목/요약/키워드: filament

검색결과 1,338건 처리시간 0.031초

FRP의 원통형 압력 용기제작을 위한 필라멘트 밴드의 감김 시뮬레이션 (Filament Band Winding Simulation for Fiber Reinforced Cylindrical Pressure Vessels)

  • 윤재득;;정융호
    • 한국CDE학회논문집
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    • 제19권1호
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    • pp.19-28
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    • 2014
  • The filament winding method is widely used to manufacture products of fiber reinforced plastics (FRP), such as high pressure vessels, launch tubes and pipes. For reducing winding time, the method of winding by filament band which consists of several filament fibers is used. NC winding machine is used for precise winding and NC path is needed. Before filament winding, users should verify that winding path which presented by a line is appropriate by filament winding simulation. Also, the used length of each filament is different. So, if the peak filament exhausted, it causes to stop manufacturing. In this research, we developed software which visualizes 3D graphic of filament band winding path and simulates winding process on real time. And we proposed algorithm about calculation of each filament usage. We use geodesic equation for generating filament band surface and calculating the usage length of each filament.

Silk Filament Progression with Backcross Breeding Generations in Tropical Tasar Silkworm, Antheraea mylitta D

  • Reddy, Rangareddygari Manohar;Suryanarayana, Nagabathula;Sinha, Manoj Kumar;Gahlot, Nand Singh;Hansda, Ganga;Ojha, Nand Gopal;Prakash, Nanjappa Basappa Vijaya
    • International Journal of Industrial Entomology and Biomaterials
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    • 제19권1호
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    • pp.187-192
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    • 2009
  • Silk filament progression study applying backcross breeding with recipient parent Jata and donor parent Daba ecoraces of tropical tasar silkworm, Antheraea mylitta Drury conducted during 2006 to 2008, revealed introgression of filament denier (10.2 d) superior to both parents at BC4 level. Also, the silk waste (0.35%) and filament breaks (2.6 nos) were reduced compared to both parents, while the filament length (973 m) and non break filament (296 m) improved over donor and could attain closer to recipient parent. The best performance of Jata $\times$ Daba at F1 level, with highest silk filament length (1646 m) of 12.5 d denier, denotes heterosis impact on silk trait with parental heterogenousity, an advantage to exploit silk filament yield. The progression of quality in terms of finer filament denier, less silk waste and least number of filament breaks over both parents and improvement in filament length and non break filament over donor parent except for a marginal shortage against recipient at BC4 level indicates the prospects of Jata and Daba ecoraces as source of breeding material for qualitative improvement of tasar silk filament. The study suggests that the commercially important finer denier of tasar silk filament can be attained with minor reduction in silk yield of wild Jata ecorace by adopting repeated backcrossing for four generations with semi domesticated Daba ecorace.

Characterization of Luster Properties of Nylon 6 Hollow Filament Yarn Woven Fabric - Three-dimensional Simulation of Hollow Filament -

  • Kim, Jong-Jun;Jeon, Dong-Won;Jeon, Jee-Hae
    • 패션비즈니스
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    • 제8권6호
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    • pp.68-77
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    • 2004
  • Hollow filament yarns provide better warmth to the touch, lighter in weight, increased opacity, and subtle luster compared to the regular synthetic filament yarns. However, luster properties of textile fibers or fabrics are often difficult to characterize, partly due to the fineness of the surface texture, the anisotropic nature of the weave structure, the complexity of the fiber array comprising a yarn, and the fiber structure itself. In this study, the fabric surface luster image was analyzed using image analysis methods after image acquisition. The hollow filament fiber was modeled using a three-dimensional modeling software. It was then ray-traced for comparing the virtual luster images of the hollow fiber and the regular fiber models based on shading models including photon mapping. The luster object size of the actual hollow filament fabric was smaller than that of the regular filament fabric. The shape of the luster object of the hollow filament fabric was dual peak type while that of the regular filament was single.

Fabrication of Potassium Ion Source and its Emission Characteristics

  • Choi, Dae Sun
    • Applied Science and Convergence Technology
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    • 제25권6호
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    • pp.116-119
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    • 2016
  • In this study, we fabricated the $K^+$ ion source for the various purposes and investigated the emission characteristics. The fabricated $K^+$ ion source was painted in the tungsten filament to make filament type ion source. The RGA spectra show that the filament type $K^+$ ion source has a good out gassing character, so it can be used in the ultra-high vacuum system. The maximum $K^+$ ion current was 20 mA when filament temperature was 1410 K and filament potential was 50 V. When the filament temperature was 1070 K, the initial beam current was 50 mA and decreased only by 2% during 4 hours. The emitting energy was measured to be 2.04 eV. This low value means that the fabricated specimen is a good $K^+$ ion source. We conclude that this filament type ion source can be used in various fields, including the LEIS research.

Cocoon Filament Quality of a Special Silkworm Variety, GoldenSilk

  • Kweon, Hae-Yong;Lee, Kwang-Gill;Park, Kwang-Young;Kang, Seok-Woo;Kang, Pil-Don;Kim, Mi-Ja;Kim, Kee-Young
    • International Journal of Industrial Entomology and Biomaterials
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    • 제24권1호
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    • pp.17-21
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    • 2012
  • The effect of cultivation season on the cocoon filament quality of authorized silkworm variety, GoldenSilk was examined with cocoon filament character, reeling character, and fiber character during 3 years. In cocoon filament character, filament length of spring and autumn cocoon was 979 and 879 m, respectively. Cocoon filament weight of spring and autumn cocoon was 33.1 and 26.5 cg, which is lower than that of general bivoltine strain, BaeGokJam. Raw silk percentage of spring and autumn cocoon was 15.65 and 13.77%, respectively. In reeling character, reelability showed similar trend regardless of cultivation season and strain. However, the length and weight of non-broken filament of spring season were slightly higher than those of autumn cocoon. Cultivation season did not affect on the fiber characteristics such as clearness and neatness, lousiness, and degumming loss. In cocoon character, filament length, size, and weight, spring cocoon filament showed higher value than autumn cocoon, but lower than authorized general silkworm varieties. In reeling characteristics, non-broken length and weight showed the similar trends with the cocoon filament character. However, the reelability of GoldenSilk cocoon was not affected by cultivation season. The reelability of GoldenSilk cocoon was also similar with that of authorized general one. Fiber character including clearness and neatness, lousiness, and degumming loss was also similar regardless of the rearing season and different strain.

초음파 팬텀 내 모노필라멘트의 해상력 개선에 대한 연구 (Improvement on resolution of mono-filament wire)

  • 마상철;공영건
    • 대한방사선기술학회지:방사선기술과학
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    • 제26권2호
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    • pp.49-56
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    • 2003
  • 초음파 Q/A팬텀은 조직등가물질(TMM)과 표적물질로 구성한다. 표적물질은 데드존, 거리분해능, 측분해능, 수직과 수평거리 정확성 등을 평가하는 모노필라멘트로 TMM과 조화를 이뤄 선명하게 나타나야 한다. 본 연구의 목적은 금속성 모노필라멘트와 나일론 모노필라멘트를 이용하여 TMM 내에서 최적의 해상력을 표현할 수 있는 선 표적물질을 얻기 위해 탈기수와 C15 g TMM을 합성하여 모노필라멘트를 설치하고 SONOACE 6000C $3.5{\sim}7.5\;MHz$를 주사하여 다음과 같은 결론을 얻었다. 1. 0.1 mm 금속성 모노필라멘트와 0.12 mm, 180데너아 나일론 모노필라멘트에서 점상의 선명한 에코양상을 관찰할 수 있었다. 2. 0.2 mm 금속성과 나일론 모노필라멘트는 다중반사에 의한 혜성꼬리음영이 관찰되었다. 3. 데드존과 거리분해능은 0.1 mm 나일론 모노필라멘트가 유용한 것으로 나타났다. 4. 나일론 모노필라멘트는 금속성 모노필라멘트에 비해 견고성과 수축성이 우수하여 팬텀제작에 유리한 것으로 나타났다. 5. TMM의 경도 차가 모노필라멘트의 에코 양상에 많이 관여하지 않는 것으로 나타났다.

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The Motion of Plasma in an Excited Quiescent Filament

  • Song, Dong-Uk;Chae, Jong-Chul
    • 천문학회보
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    • 제35권2호
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    • pp.48.2-48.2
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    • 2010
  • Quiescent filaments are bigger, more stable, and longer lived than active region filaments. So, the shape of a quiescent filament changes little during its lifetime and a fast motion of plasma rarely occurs. But when it is dynamically influenced by external phenomena, a rapid motion of plasma may temporarily occur. By analyzing the motion of plasma we can infer some of the magnetic structure permeating such an excited quiescent filament. We analyzed the H$\alpha$ images of a quiescent filament in the northern hemisphere that was observed at Big Bear Solar Observatory on 2004 August 2, and found that: 1) the filament was excited by a flare that occurred in a remote active region located in the southern hemisphere, 2) By this excitation, a part of the filament moved vertically upward and horizontally out of main body, and then it stayed there without much motion. Then after it moved vertically downward and horizontally to the main body, 3) the final position of plasma, however, was not the same as the initial position, being about 14Mm above it. We suggest that the filament was initially in a more or less static equilibrium. The excitation of the filament broke the initial equilibrium, and then brought about a new one that is different from the original one. Since the filament should have magnetic field, it is likely that both the equilibria may have been maintained by diplike magnetic structures. Furthermore, the transition from one equilibrium to another as we inferred should have accompanied a permanent change of magnetic configuration as well.

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Studies on Cocoon Filament Size Deviation in Multivoltine Breeds and Multivoltine ${\times}$ Bivoltine Hybrids of Silkworm, Bombyx mori L.

  • Rao, D.Raghavendra;Singh, Ravindra;Kariappa, B.K.;Dandin, S.B.
    • International Journal of Industrial Entomology and Biomaterials
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    • 제9권2호
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    • pp.273-277
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    • 2004
  • Variation in the size of the silk filament will determine the uniformity and quality of the silk reeled. In the present study, an attempt has been made to study the filament size variation in 6 multivoltine parental breeds and 9 multivoltine ${\times}$ bivoltine hybrids in all three seasons of a year. All multivoltine breeds and multivoltine ${\times}$ bivoltine hybrids showed variation in filament size throughout its length from the outer layer to inner layer. Results of the present study indicated that the size of the filament decreased from outer to inner layer. The decrease in filament size was sudden in some breeds/hybrids whereas it was gradual in other. Relationship between filament length to that of slope, average filament size to slope, and maximum filament size to slope was determined based on regression analysis. Regression analysis revealed significant positive correlation between slope vs average filament length (r=0.92$^{**}$) in multivoltine${\times}$bivoltine hybrids. Among parental breeds, 96C showed lowest slope of the curve (b-value: -0.00428) and 96A showed highest slope of the curve (b-value: -0.00269). Among 9 hybrids, PM${\times}$N $B_4$ $D_2$ recorded lowest slope value (b-value: -0.00328) and BL24${\times}$N $B_4$ $D_2$ showed highest value for slope of the curve (b-value: -0.00234). The breed 96C, which showed lowest slope value can be utilized for future breeding programmes to breed strains with less size deviation. Three multivoltine${\times}$bivoltine hybrids viz., PM${\times}$N $B_4$ $D_2$, 96E${\times}$CSR19 and BL67${\times}$CS $R_{101}$ , which showed less slope values (b-values: -0.00328, -0.00300 and -0.00297 respectively) can be utilized for commercial exploitation to produce uniform silk.k.

유한요소법에 의한 Bi2223 고온 초전도 선재의 다심 인발에 대한 연구 (A Study on Multi-Filament Drawing of Bi2223 High-Temperature Superconductivity Wire by FE Method)

  • 박동인;김병민;오상수
    • 소성∙가공
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    • 제13권1호
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    • pp.78-83
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    • 2004
  • High-temperature superconduction materials(Bi2223) possess electrical/electronic and magnetic properties. Because high-temperature superconduction materials is a ceramic powder, that cannot be produced singlehandedly. So Ag sheathed Bi-2223 wire was produced by drawing process using powder-in-tube(PIT) method. This superconductor has many difficulties to produce. The main difficulty is that the mechanical properties of the ceramic powder are very different from those of the Ag sheath. And by these properties, Bi2223 high-temperature superconductor, which has a single filament drawing process and multi-filament drawing process, has a defect like sausaging and bursting at a center. This study analyzed multi-filament drawing process by FEM, and a defect generated during multi-filament drawing was studied by FEH. Specially, in order to prevent a bursting at a center, this study presented a method that inserts a pure Ag at a center of multi-filament wire

리튬 이온 기반 멤리스터 커패시터 병렬 구조의 저항변화 특성 연구 (A Study on the Resistve Switching Characteristic of Parallel Memristive Circuit of Lithium Ion Based Memristor and Capacitor)

  • 강승현;이홍섭
    • 마이크로전자및패키징학회지
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    • 제28권4호
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    • pp.41-45
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    • 2021
  • 본 연구에서는 멤리스터 소자의 높은 신뢰성을 확보하기 위해 소자 제작 단계에서 30 nm 두께의 ZrO2 금속산화물 박막 위 국부영역에 리튬 filament seed 층을 패턴하여 작은 이온반경의 리튬이온을 저항변화 주체로 활용하는 멤리스터 소자를 구현하였다. 패턴 된 리튬 filament seed 대비 다양한 상부전극의 면적을 적용하여 멤리스터-커패시턴스 병렬 구조의 이온형 저항변화 소자에서 커패시턴스가 filament type 저항변화 특성에 미치는 영향을 조사하고자 하였다. 이를 위해 ZrO2 박막 위에 5 nm 두께, 5 ㎛ × 5 ㎛ 면적의 리튬 filament seed 증착 후 50 ㎛, 100 ㎛ 직경의 상부전극을 증착, 리튬 메탈의 확산을 위한 250℃ 열처리 전 후 샘플에서 저항변화 특성을 확인하였다. 열확산에 의해 형성된 전도성 filament의 경우 전압에 의한 제어가 불가함을 확인하였으며, 전압에 의해 형성된 filament만이 electrochemical migration에 의한 가역적 저항변화 특성 구현이 가능한 것을 확인하였다. 전압에 의한 filament 형성 시 병렬로 존재하는 커패시턴스의 크기가 filament의 형성 및 소실에 중요한 인자임을 확인하였다.