• Title/Summary/Keyword: breaking strain

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Characterization of Conductive Polypyrrole Coated Wool Yarns

  • Kaynak, Akif;Wang, Kijing;Hurren, Chris;Wang, Xungai
    • Fibers and Polymers
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    • v.3 no.1
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    • pp.24-30
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    • 2002
  • Wool yams were coated with conducting Polypyrrole by chemical synthesis methods. Polymerization of pyrrole was caned out in the presence of wool yarn at various concentrations of the monomer and dopant anion. The changes in tensile, moisture absorption, and electrical Properties of the yam upon coating with conductive polypyrrole are Presented. Coating the wool yams with conductive Polypyrrole resulted in higher tenacity, higher breaking strain, and lower initial modulus. The changes in tensile properties are attributed to the changes in surface morphology due to the coating and reinforcing effect of conductive Polypyrrole. The thickness of the coating increased with the concentration of p-toluene sulfonic acid, which in turn caused a reduction in the moisture regain of the wool yin. Reducing the synthesis temperature and replacing p-toluenesulfonic acid by anthraquinone sulfonic acid resulted in a large reduction in the resistance of the yam.

Reinforcing effect of Single Wall Carbon Nanotubes on Acrylic Fibers

  • Min, Byung G.;Sreekumar, T.V.;Kumar, Satish
    • Proceedings of the Korean Fiber Society Conference
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    • 2003.10a
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    • pp.11-12
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    • 2003
  • The reinforcing effect of single wall carbon nanotubes (SWNTs) on polyacrylonitrile (PAN) fiber were investigated. The tensile fracture images of the composite fibers demonstrate that SWNTs are well dispersed in PAN matrix as bundles (ropes) ca. 20nm in thickness. It was found that SWNTs play a role not only to reinforce but also to toughen the PAN fiber by increasing breaking strain as well as modulus and strength of the fiebrs. The composite fibers exhibited improved dimensional stability at elevated temperature compared to the neat PAN fiber.

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Effect of False Twist Processing Conditions on the Physical Properties of PET DTY (PET 가연공정특성이 DTY의 물성에 미치는 영향)

  • 이민수;김승진;박경순
    • Textile Coloration and Finishing
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    • v.15 no.6
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    • pp.33-38
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    • 2003
  • This study surveys the effects of POY physical properties and processing conditions of belt texturing machine to the textured yarns. The various textured yarns are made with the variations of 1st heater temperature, draw ratio, velocity ratio, and the physical properties of these specimens such as yam linear density, tenacity, breaking strain, and wet and dry thermal shrinkages are measured and analysed with the various processing conditions of texturing machine. Especially, the thermal characteristics of the textured yarns, which are affected at the fabric hands and the determination of the processing conditions in the dyeing and finishing processes, are investigated through the thermal stress analyser and DSC experiments.

Surface Modification of Polypropylene Meltblown(PPMB) Nonwovens by Plasma Treatment (초극세형 폴리프로필렌부직포의 플라즈마를 이용한 표면개질)

  • Lee, Youn-Eung;Joo, Chang-Whan
    • Textile Coloration and Finishing
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    • v.18 no.1
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    • pp.20-27
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    • 2006
  • On the purpose of surface modifications of polypropylene meltblown(PPMB) nonwovens, PPMB nonwovens were treated in the plasma system by oxygen atmosphere with different treatment time and discharge power. Dimensional change and physical properties of the treated nonwovens were evaluated. Contact angles onto PPMB nonwovens about water and methyleneiodide were measured and surface energies were calculated by Owen's method. As the results, microcraters were observed on the surface of treated nonwovens. Tenacity and breaking strain of PPMB nonwovens decreased with increasing treatment time and discharge power. Surface energy of PPMB nonwovens increased by plasma treatment. Meanwhile, the friction static voltage and dyeability of PPMB nonwovens have enhanced to some extent by oxygen plasma treatment due to the improvement of surface hydrophilicity.

A study on the Impact Characteristics for Rubber Toughened polymeric Materials under Low Velocity Impact (고무보강 폴리머 재료의 저속 충격 해석)

  • 구본성;박명균;박세만
    • Proceedings of the Safety Management and Science Conference
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    • 2004.05a
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    • pp.219-231
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    • 2004
  • The Charpy and Izod impact tests are the most prevalent techniques used to characterize the effects of high impulse loads on polymeric materials. An analysis method for rubber toughened PVC is suggested to evaluated critical dynamic strain energy release rates(G$_c$) from the Charpy impact tester was used to extract ancillary information concerning fracture parameters in additional to total fracture energies and maximum critical loads. The dynamic stress intensity factor KID was computed for varying amounts of rubber contents from the obtain maximum critical loads and also toughening effects were investigated as well. The fracture surfaces produced under low velocity impact for PVC/MBS composites were investigated by SEM. The results show that MBS rubber is very effective reinforcement material for toughening PVC.

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A study on properties of sector gear for seat recliner (Seat recliner용 sector gear의 fine blanking에 관한 연구)

  • Kim, Chang-ho;Kang, Soo-ho;Lee, Kwan-young;Nam, Ki-woo
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.9 no.1
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    • pp.99-105
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    • 2010
  • This study was performed to solve the breaking problem in the fine blanking(FB) process of sector gears for car seat recliner using nickel chrome molybdenum steel(SNCM220) plate. The optimal design of embossing circle is changed to oval with labors' experiences and finite element analysis. The maximum principal stress and effective strain in a forming process are analyzed by commercial finite element software to solve the problems in embossing stage of FB process. As a result of FE analysis, the maximum principal stress in forming is lower than yield point of material. It is shown from experiments in the modified die that the formed gear does not break in embossing stage.

The Physical Property of Knitted Fabrics for High Sensible Garment according to the Spinning Method using Organic Cotton (오가닉 코튼 원사제조 방법에 따른 고감성 의류용 편성물의 물리적 특성)

  • Kim, Hyun-Ah;Kim, Hyun-Chel
    • Fashion & Textile Research Journal
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    • v.15 no.4
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    • pp.606-612
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    • 2013
  • This paper investigates the physical properties of organic cotton staple yarns manufactured by ring and siro spinning methods as well as analyzes the physical properties of fabric specimens knitted with staple yarns made by these two methods. The breaking stress and evenness of organic ring staple yarns showed the same level for the Japanese specimens as the control yarns; in addition, the same coefficient for the friction of the manufactured yarns and Japanese specimens was also shown. These results makes it possible to manufacture organic staple ring yarns from organic cotton fibers. The tenacity and breaking strain of siro staple yarns were higher than ring staple yarns. The evenness and friction coefficient of siro staple yarns were lower than the ring staple yarns; in addition, hairiness and the number of siro staple yarns was significantly lower than the ring staple yarns. The dimensional stabilities of knitted fabrics by 20 Ne and 30 Ne siro staple yarns were superior to ring staple yarns. The color fastnesses of washing, perspiration and abrasion of knitted fabrics by two spinning methods showed the same level as the 4.5 grade; however, the light fastness of knitted fabric by siro staple yarns was superior to ring staple yarns. It was shown that the siro spinning method (using eco-friendly organic cotton fibers) was applicable to a high sensible knitted garment that overcame drawbacks of organic fibers related to shrinkable properties after washing and low color fastness to light.

Far-Infrared Emission Characteristics of Germanium Included Fabrics for Emotional Garment (게르마늄 함유 감성의류용 직물의 원적외선 방출 특성)

  • Kim, Hyun-Ah;Kim, Seung-Jin
    • Science of Emotion and Sensibility
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    • v.13 no.4
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    • pp.687-692
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    • 2010
  • This paper surveys emission characteristics of Far-infrared of the fabrics fabricated with germanium imbedded sheath-core conjugate composite filaments. For this purpose, master batch chip was prepared with PET semi-dull chip and nano sized germanium particles and sheath-core type conjugate composite filament was spun using this master batch chip and polyester semi dull. The emission power and emissivity of the germanium imbedded fabrics were measured and investigated using FT-IR spectrophotometer by KICM- FIR 1005 measurement method. In addition, the fabric mechanical properties were measured and discussed with the effects of the optimum texturing process conditions and fabric structural design conditions. The sheath/core type PET composite germanium imbedded filaments were manufactured by the optimum spinning condition, its tenacity and breaking strain showed the same level as the regular PET filament. The tenacity and breaking strain of the DTY showed good physical properties and no problem in the weaving process. Then, wet and dry shrinkages showed higher values than those of regular PET filament. The emission power of the germanium imbedded fabric was $3.53{\times}10^2W/m^2$ at the $5-20{\mu}m$ wave length range, and emissivity was 0.874. The fabric hand of germanium imbedded fabrics was inhanced by the optimum texturing process and fabric structural design with improved mechanical properties such as fabric bending and compressional properties.

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Structure and mechanical properties of Korean commercial silkworm cocoon (장려품종 누에고치의 구조 및 기계적 특성)

  • Kim, Sung-Kuk;Jo, You-Young;Lee, Kwang-Gill;Kim, Kee-Young;Kim, Hyun-bok;Kweon, HaeYong
    • Journal of Sericultural and Entomological Science
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    • v.53 no.2
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    • pp.97-100
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    • 2015
  • Korean commercial Bombyx mori silkworm cocoon made by Kumokjam and Daesungjam was examined to characterize for application. Amino acid analysis showed that the main amino acid of Kumokjam and Daesungjam cocoon was glycine, alanine, serine, tyrosine, and aspartic acid. The content of three major amino acids was about 67% and the content of long chain amino acids was about 37%. Stress-strain curve showed that breaking stress of Kumokjam cocoon, 50 MPa, was higher than that of Daesungjam cocoon, 48 MPa. Breaking strain of Kumokjam cocoon, 37%, was also longer than that of Daesungjam cocoon, 30%. These results might be used as basic information for development of non-textile materials using Bombyx mori silkworm cocoon.

Investigation of the impact of multi-strain probiotics containing Saccharomyces cerevisiae on porcine production

  • Sheena Kim;Jinho Cho;Gi Beom Keum;Jinok Kwak;Hyunok Doo;Yejin Choi;Juyoun Kang;Haram Kim;Yeongjae Chae;Eun Sol Kim;Minho Song;Hyeun Bum Kim
    • Journal of Animal Science and Technology
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    • v.66 no.5
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    • pp.876-890
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    • 2024
  • A balanced intestinal microbiome controls intestinal bacterial diseases, helps regulate immunity, and digests and utilizes nutrients, ultimately having a positive effect on the productivity of industrial animals. Yeasts help in the digestion process by breaking down indigestible fibers and producing organic acids, vitamins, and minerals. In particular, polysaccharides such as beta-glucan and mannan-oligosaccharides, which are present in the cell wall of yeast, inhibit the adhesion of pathogens to the surface of the gastrointestinal tract and increase resistance to disease to help maintain and improve intestinal health. Among the yeast additives used in animal feed, Saccharomyces cerevisiae is one of the most commonly used probiotics. However, it does not naturally reside in the intestine, so if it is supplied in combination with other species of probiotics that can compensate for it, many benefits and synergies can be expected for pigs in terms of maintaining intestinal health such as supplementing the immune system and improving digestion. A number of previous studies have demonstrated that dietary complex probiotic supplementation has growth-promoting effects in pigs, suggesting that multiple strains of probiotics may be more effective than single strain probiotics due to their additive and synergistic effects. In practice, however, the effects of complex probiotics are not always consistent, and can be influenced by a variety of factors. Therefore, this review comprehensively examines and discusses the literature related to the effects of complex probiotics using Saccharomyces cerevisiae in pig production.