• Title/Summary/Keyword: Fiber Formation

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A study on the orthogonal cutting characteristics of glass fiber reinforced plastics (복합재료의 직교 절삭가공 특성에 관한 연구)

  • 송화용;정용운;김준현;김주현
    • Proceedings of the Korean Society of Machine Tool Engineers Conference
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    • 2001.10a
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    • pp.155-160
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    • 2001
  • In the use of glass fiber reinforced plastics(GFRP) it is often necessary to cut the components, but the cutting of GFRP is often made difficult by the delamination of the compositions and short tool life. Experimental investigation was conducted to evaluate the chip formation of the glass fiber reinforced plastics during orthogonal cutting. The chip formation process, cutting force, and thrust force were studied. The chip formation processes were studied through the use of quick-stop device. Chip-tool contact areas were obtained with the use of the quick-stop device, and observed using optical microscopy after polishing. Cutting force and thrust force were measured through the use of the tool dynamometer.

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Effect of Vat Control in Cylinder Machine on Physical Properties of Paper (환망 초지기의 배트 운용이 종이의 품질에 미치는 영향)

  • Park, Yong-Sung;Jeon, Yang;Seo, Yung Bum
    • Journal of Korea Technical Association of The Pulp and Paper Industry
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    • v.32 no.2
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    • pp.51-57
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    • 2000
  • Cylinder machine usually gives more fiber orientation than fourdrinier and has limitation in machine speed because of fiber wash-off caused by centrifugal force when machine speed increases. This study aimed for the improvement of paper formation and productivity by setting an apron in vat inlet and by adjusting mould water head. Improvement of formation and increase of machine speed were achieved, which ultimately improve productivity. Installing an apron successfully decreased fiber wash-off. Fiber orientation and two-sideness of ash distribution became less severe. The proper adjustment of water head inside the cylinder mould proved to be an important factor not only in paper formation but also in decreasing paper two-sideness.

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Role of flgA for Flagellar Biosynthesis and Biofilm Formation of Campylobacter jejuni NCTC11168

  • Kim, Joo-Sung;Park, Changwon;Kim, Yun-Ji
    • Journal of Microbiology and Biotechnology
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    • v.25 no.11
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    • pp.1871-1879
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    • 2015
  • The complex roles of flagella in the pathogenesis of Campylobacter jejuni, a major cause of worldwide foodborne diarrheal disease, are important. Compared with the wild-type, an insertional mutation of the flgA gene (cj0769c) demonstrated significant decrease in the biofilm formation of C. jejuni NCTC11168 on major food contact surfaces, such as polystyrene, stainless steel, and borosilicate glass. The flgA mutant was completely devoid of flagella and non-motile whereas the wild-type displayed the full-length flagella and motility. In addition, the biofilm formation of the wild-type was inversely dependent on the viscosity of the media. These results support that flagellar-mediated motility plays a significant role in the biofilm formation of C. jejuni NCTC11168. Moreover, our adhesion assay suggests that it plays an important role during biofilm maturation after initial attachment. Furthermore, C. jejuni NCTC11168 wild-type formed biofilm with a net-like structure of extracellular fiber-like material, but such a structure was significantly reduced in the biofilm of the flgA mutant. It supports that the extracellular fiber-like material may play a significant role in the biofilm formation of C. jejuni. This study demonstrated that flgA is essential for flagellar biosynthesis and motility, and plays a significant role in the biofilm formation of C. jejuni NCTC11168.

A Study of the Characteristic Changes of Self-Compacting Concrete with mixing shifted contents of Steel Fibers (섬유 변화량에 따른 고유동 자기충전 콘크리트의 특성변화에 관한 연구)

  • Lee, Keun-Su;Choi, Yeol;Lee, Jae-Ik;Jung, Woong
    • Proceedings of the Korea Concrete Institute Conference
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    • 2009.05a
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    • pp.243-244
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    • 2009
  • Fibers reinforced concrete(FRC) has abilities to make up for brittleness fracture as one of the material characteristics of concrete. However, being mixed with steed fibers in concrete mixes could set off a "Fiber Ball". The Fiber ball formation could be one of the main reasons to decrease the quality of Fibers reinforced concrete. In order to eliminate the fiber ball formation and improve the deficient flowablitiy, The necessity of research for fiber reinforced self-compacting concrete(FRC-SCC) should be raised.

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Numerical Simulation of Particle Deposition Pattern on Cylindrical Fiber under External Electrical Field (외부 전기장내의 단일 섬유에 대한 먼지층 형사 수치 모사)

  • 박현설;정용원;박영옥;이규원
    • Journal of Korean Society for Atmospheric Environment
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    • v.15 no.1
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    • pp.41-51
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    • 1999
  • In this study, the two dimensional morphology of particle accumulates on a cylindrical fiber was numerically simulated when a uniform external electric field was present across a cylindrical fiber. In order to investigate the mechanism of linear dendrite formation which is observed under the above electrostatic condition, the electrostatic forces between a newly introduced particle and each deposited particle were calculated and compared with those between the particle and fiber As a result of this study it was found that dielectrophoretic forces between the oncoming particle and fiber play principal roles in linear dendrite formation.

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Sheet Formation Properties of Morus Hanji (뽕나무 한지의 지합특성)

  • Yi, Il-Roh;Cho, Nam-Seok
    • Journal of Korea Technical Association of The Pulp and Paper Industry
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    • v.38 no.3 s.116
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    • pp.47-60
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    • 2006
  • This study was carried out to investigate the sheet formation properties of Morus Hanjis, made of bast and whole stalk pulps by different pulping methods, such as alkali, alkali-peroxide and sulfomethylated pulping. Two species of Morus, M. alba and M. lhou, were used. Effect of morphological properties of pulp stocks on the sheet formation and its gray levels based on optical property were evaluated using an Image analyzer. In addition, the effect of fiber distribution index(FDI) which was calculated from tile data of Confocal laser scanning microscopy(CLSM) on the sheet formation and optical properties of Morus Hanji were also discussed. On the sheet formation, Hanji from whole stalk pulp was superior than that of bast pulp. The more the sheet formation improved, the more paper opacity decreased. In the aspect of Hanji's surface characteristics analyzed by an Image analyzer, the average gray level and its standard deviation of Hanji from the whole stalk pulp were rather lower than those of bast pulp because of better sheet formation of the former. However, high brightness Hanji showed high value of gray level. The sheet formation and paper opacity were increased with the decrease of standard deviation of gray level. From these results, gray level measurement could be used to predict the paper opacity as well as sheet formation. Sheet formation of whole stalk Hanji and its FDI measured by CLSM were higher than those of bast fibers. In conclusion, the sheet formation and opacity of Hanji could be evaluated by standard deviation value of Hanji's gray level using an Image analyzer and by fiber distribution index using CLSM.

Quality analysis of Reconstituted tobacco ( I ) - On the Physical and Structural properties - (판상엽 품질 특성 분석 (제1보) - 물리적ㆍ구조적 특성에 관하여 -)

  • 한영림;나도영;김삼곤;김근수;강영희
    • Journal of the Korean Society of Tobacco Science
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    • v.26 no.1
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    • pp.57-63
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    • 2004
  • A comparative analysis of characteristics of domestic and foreign reconstituted tobacco based on papermaking was conducted to evaluate the quality of reconstituted tobacco and to utilize as basic data for improvement of domestic reconstituted tobacco. In the formation, which is key factor to quality and physical properties of product, foreign reconstituted tobacco has better uniform formation than those of domestic one. These result was attributed to distribution of large floc size in the domestic one unevenly. In the fiber morphology, domestic reconstituted tobacco has larger average fiber length and width than those of foreign one. They indicated that fiber morphology of domestic one will exert structural properties of paper such as formation and permeability. Tensile strength of domestic one has lower than those of foreign one by basis weight. In the air permeability, domestic one was remarkably reduced because base web was over sized. It also will affect the combustibility of reconstituted tobacco. In summary, we conclude that the physical and structural properties of domestic reconstituted tobacco result in quality deviations compared with foreign reconstituted tobacco.

A Study of the Formation Process of the Fabric Drapes

  • Mizutani, Chiyomi;Baba, Takeichirou;Amano, Toshihiko
    • Proceedings of the Korean Fiber Society Conference
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    • 2003.10a
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    • pp.111-111
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    • 2003
  • In our experiments using a new apparatus, the drape formation process was found to consist of three stages, seeds generation, their development and the final stabilizing stages. A new parameter R evaluating the shape of the drape was defined in terms of the vertical projection of the drape. Both drape coefficient and R-parameter are expected to be useful for analyzing the formation process of the fabric drape quantitatively.

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A Study on the Change of Hand of Nettle Denim (네틀 데님소재의 태의 변화에 관한 연구)

  • Lee, Jungmin
    • Journal of Fashion Business
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    • v.22 no.2
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    • pp.107-117
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    • 2018
  • Nettle fiber, a sustainable fiber, was applied to the fabrication of denim to identify changes in textile appearance and formation. For the weaving of nettle denim, nine specimens, distinguished by three kinds of composite use of nettle fiber and three stages of fabrication processes, were used. The kinetic characteristics of the nine specimens were measured by the KES-FB system, and the images of the specimens of finished denim textiles, captured with a CCD Camera, were analyzed. In terms of the extensibility (EM) of nettle denim, all specimens showed post-processing increase, thereby suggesting an easy transformation of the textile as a source material for denim fabric. The effects of washing on the woven formation of denim were also identified. The geometric roughness (SMD), the problematic property of bast-fiber-like nettle fiber, was found to be decreased by washing. In terms of the bending rigidity (B) of the textile, the post-processing shrinking percentage of elastic nettle denim was found to decrease; all specimens that underwent bio-washing only also manifested that post-processing elasticity increased. To improve the draping of nettle denim, a mixed spinning together with washing were found to be advantageous. In terms of the shear stiffness (G), which is closely associated with the appearance of clothes, the formation of textile was improved regardless of the types of processing, including bio-washing and bleach washing.