• Title/Summary/Keyword: cellulose fiber

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Effects of Specialty Cellulose Fibers on Improvement of Flexural Performance and Control of Cracking of Concrete (콘크리트의 휨성능 증진 및 균열제어에 대한 특수 가공된 셀룰로오스섬유의 효과)

  • 원종필;박찬기
    • Journal of the Korea Concrete Institute
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    • v.12 no.2
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    • pp.89-98
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    • 2000
  • The mechanical properties of specialty cellulose fiber reinforced concrete and the contribution of specialty cellulose fiber to drying shrinkage crack reduction potential of concrete and theirs evaluation are presented in this paper. The effects of differing fiber volume fraction(0.03%, 0.06%, 0.08%, 0.1%, 0.15%, 0.2%) were studied. The results of tests of the specialty cellulose fiber reinforced concrete were compared with plain and polypropylene fiber reinforced concrete. Flexural performance(flexural strength and flexural toughness) test results indicated that specialty cellulose fiber reinforcement showed an ability to increase the flexural performance of normal- and high- strength concrete(as compared to plain and polypropylene fiber reinforced concrete). Optimum specialty cellulose fiber reinforced concrete were obtianed using 0.08% fiber volume fraction. Drying shrinkage cracking test results confirmed specialty cellulose fibers are effective in reducing the drying shrinkage cracking of normal and high-strength concrete(as compared to popylene fiber reinforced concrete).

Field Case Study of Mechanized Form Roads Pavement Construction using Cellulose Fiber Reinforced Concrete (셀룰로오스 섬유보강 콘크리트를 사용한 기계화경작로 확·포장공사의 현장사례 연구)

  • Park, Jong Gun
    • Journal of The Korean Society of Agricultural Engineers
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    • v.57 no.2
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    • pp.47-56
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    • 2015
  • At the present, the mechanized form roads pavement was constructed with plain concrete. Mostly, it was used by welded wire mesh for preventing crack. Cellulose fibers for the reinforcement of concrete offer relatively high levels of elastic modulus, fiber count (per unit weight), specific surface, and bond strength to cement-based materials. The construction of concrete pavement confirmed that cellulose fiber reinforced concrete was applicable to mechanized form roads pavement. In the study, cellulose fibers were used here at 0.08 % volume fraction, which is equivalent to a fiber content of $1.2kg/m^3$. Cellulose fiber reinforced concrete were compared with plain concrete. Field test results indicated that cellulose fiber reinforced concrete showed slightly to increase of 28 days compressive strength and improved the initial strength. it tended to increase of splitting tensile strength. Test results showed that the slump and air content tend to decreased. but, the variation of air contends is very little. Also, construction cost of cellulose fiber reinforced concrete is less than about 25.7 % the case of welded wire mesh previously used. Therefore, The cost reduction is expected to be possible in construction site by mechanized form roads pavement.

Oxide Semiconductor Thin Film Transistor based Solution Charged Cellulose Paper Gate Dielectric using Microwave Irradiation

  • Lee, Seong-Yeong;Jo, Gwang-Won;Jo, Won-Ju
    • Proceedings of the Korean Vacuum Society Conference
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    • 2015.08a
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    • pp.207.1-207.1
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    • 2015
  • 차세대 디스플레이 소자로서 TAOS TFT (transparent amorphous oxide semiconductor Thin Film Transistor)가 주목 받고 있다. 또한, 최근에는 값 비싼 전자 제품을 저렴하고 간단히 처분 할 수 있는 시스템으로 대신 하는 연구가 진행되고 있다. 그중, cellulose-fiber에 전기적 시스템을 포함시키는 e-paper에 대한 관심이 활발하다. cellulose fiber는 가볍고 깨지지 않으며 휘는 성질을 가지고 있다. 가격도 저렴하고 가공이 용이하여 차세대 기판의 재료로서 주목받고 있다. 하지만, cellulose-fiber 위에는 고온의 열처리공정과 고품질 박막 성장이 어려워서 TFT 제작에 어려움을 겪고 있다. 이러한 문제를 해결하기 위해서 산화물 반도체를 이용하여 TFT를 제작한 사례가 보고되고 있다. 또한, 채널 물질 뿐만 아니라 cellulose fiber에도 다른 물질을 첨가하거나 증착하여 전기적 화학적 특성을 개선시킨 사례도 많이 보고되고 있다. 본 연구에서는 가장 저품질의 용지로 알려진 신문지와 A4용지를 gate dielectric을 이용하여서 a-IGZO TFT를 제작하였다. 하지만, cellulose fiber로 만들어진 TFT의 경우에는 고온의 열처리가 불가능 하다. 따라서 저온에서 높을 효율은 보이는 microwave energy를 이용하여 열처리를 진행하였다. 추가적으로 저품질의 종이의 특성을 개선시키기 위해서 high-k metal-oxide solution precursor를 첨가 하여 TFT의 특성을 개선시켰다. 결과적으로 cellulose fiber에 metal-oxide solution precursor을 첨가하는 공정과 micro wave를 조사하는 방법을 사용하여 100도 이하에서 cellulose fiber를 저렴하고 우수한 성능의 TFT를 제작에 성공하였다.

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Effect of Gooking on Water Insoluble Dietary Fiber in Vegetables (조리방법에 따른 채소의 불용성 식이섬유 함량 변화에 관한 연구)

  • 계수경
    • The Korean Journal of Food And Nutrition
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    • v.8 no.2
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    • pp.116-127
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    • 1995
  • Recently, interests of dietary fiber associated with critical physiological effects have been rising in Korea physiological effect in the body. In the present study, the contents of fiber components in 15 kinds of vegetables being consumed commonly in Korea were investigated, and the effects of various treatments (cooking and Kimchi fermentation) on fiber were studied. The results are summarized as follows. Fiber contents of vegetables were 11.8∼31.9% of neutral detergent fiber(NDF), total insoluble dietary fiber, 10.9∼25.4% of acid detergent fiber(ADF), 8.8∼23.8% of cellulose, 0.6∼10.6% of hemicellulose and 1.0∼5.2% of lignin, on dry weight basis. Especially, peppers had higher contents of NDF than the other vegetables. In the vegetables used in the present study, it was found that a great portion of NDF, total insoluble dietary fiber, was composed of cellulose because cellulose covered 63% of NDF. 'Cooking increased the NDF, ADF and cellulose contents, and most change was due to the change of cellulose. The values of hemicellulose and lignin showed an Irregular pattern upon cooking. Fermentation slightly increased NDF, ADF and cellulose, while hemicellulose and lignin showed irregular pattern.

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Optimization of Carbonated Cellulose Fiber-Cement Composites

  • Won, Jong-Pil;Bae, Dong-In
    • KCI Concrete Journal
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    • v.12 no.1
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    • pp.79-89
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    • 2000
  • This research developed an accelerated curing processe for cellulose fiber reinforced cement composites using vigorous reaction between carbon dioxide and cement paste. A wet-processed cellulose fiber reinforced cement system was considered. Carbonation curing was used to complement conventional accelerated curing. The parametric study followed by optimization investigation indicated that the carbonation curing can enhance the productivity and energy efficiency of manufacturing cellulose fiber reinforced cement composites. This also adds environmental benefits to the technical and economical advantages of the technology.

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Oxide Semiconductor Thin Film Transistor based Solution Charged Cellulose Paper Gate Dielectric using Microwave Irradiation

  • Lee, Gi-Yong;Jo, Gwang-Won;Jo, Won-Ju
    • Proceedings of the Korean Vacuum Society Conference
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    • 2015.08a
    • /
    • pp.207.2-207.2
    • /
    • 2015
  • 차세대 디스플레이 소자로서 TAOS TFT (transparent amorphous oxide semiconductor Thin Film Transistor)가 주목 받고 있다. 또한, 최근에는 값 비싼 전자 제품을 저렴하고 간단히 처분 할 수 있는 시스템으로 대신 하는 연구가 진행되고 있다. 그중, cellulose-fiber에 전기적 시스템을 포함시키는 e-paper에 대한 관심이 활발하다. cellulose fiber는 가볍고 깨지지 않으며 휘는 성질을 가지고 있다. 가격도 저렴하고 가공이여 용이하여 차세대 기판의 재료로서 주목받고 있다. 하지만, cellulose-fiber 위에는 고온의 열처리공정과 고품질 박막 성장이 어려워서 TFT 제작에 어려움을 겪고 있다. 이러한 문제를 해결하기 위해서 산화물 반도체를 이용하여 TFT를 제작한 사례가 보고되고 있다. 또한, 채널 물질 뿐만 아니라 cellulose fiber에도 다른 물질을 첨가하거나 증착하여 전기적 화학적 특성을 개선시킨 사례도 많이 보고되고 있다. 본 연구에서는 가장 저품질의 용지로 알려진 신문지와 A4용지를 gate dielectric을 이용하여서 a-IGZO TFT를 제작하였다. 하지만, cellulose fiber로 만들어진 TFT의 경우에는 고온의 열처리가 불가능 하다. 따라서 저온에서 높을 효율은 보이는 microwave energy를 이용하여 열처리를 진행하였다. 추가적으로 저품질의 종이의 특성을 개선시키기 위해서 high-k metal-oxide solution precursor를 첨가 하여 TFT의 특성을 개선시켰다. 결과적으로 cellulose fiber에 metal-oxide solution precursor을 첨가하는 공정과 micro wave를 조사하는 방법을 사용하여 100도 이하에서 cellulose fiber를 저렴하고 우수한 성능의 TFT를 제작에 성공하였다.

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Properties of Specialty Cellulose Fiber Reinforced Concrete at Early Ages (특수 가공된 셀룰로오스섬유보강 콘크리트의 초기 특성)

  • 원종필;박찬기
    • Proceedings of the Korea Concrete Institute Conference
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    • 1999.04a
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    • pp.349-354
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    • 1999
  • Specialty cellulose fibers processed for the reinforcement of concrete offer relatively high levels of elastic modulus and bond strength. The hydrophilic surfaces of specialty cellulose fibers facilitate their dispersion and bonding in concrete. Specialty cellulose fibers have small effective diameters which are comparable to the cement particle size, and thus promote close packing and development of dense bulk and interface microstructure in the matrix. The relatively high surface area and the close spacing of specialty cellulose fibers when combined with their desirable mechanical characteristic make them quite effective in the suppression and stabilization of microcracks in the concrete matrix. The properties of fresh mixed specialty cellulose fiber reinforced concrete and the contribution of specialty cellulose fiber to the restrained shrinkage crack reduction potential of cement composites at early age and theirs evaluation are presented in this paper. Results indicated that specialty cellulose fiber reinforcement showed an ability to reduce the total area significantly (as compared to plain concrete and polypropylene fiber reinforced concrete.

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Flexural Performance of Specialty Cellulose Fiber Reinforced Concrete (특수 가동된 셀룰로오스섬유보강 콘크리트의 휨성능)

  • 원종필;박찬기
    • Proceedings of the Korea Concrete Institute Conference
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    • 1999.10a
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    • pp.311-314
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    • 1999
  • This study is aim to evaluate of the flexural performance of specialty cellulose fiber reinforced concrete. Flexural test is proceeded by third-point loading method and the size of the test specimens is 15$\times$15$\times$55cm. The rate of loading was 0.006mm/min. The effects of differing fiber volume fraction(0.08%, 0.1%, 0.15%) were studied. The results of test on the specialty cellulose fiber reinforced concrete were compared with plain and polypropylene fiber reinforced concrete. Results indicated that specially cellulose fiber reinforcement showed an improvement of flexural performance.

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Cellulose계 섬유의 새로운 전망

  • Cho, Hwan
    • Textile Coloration and Finishing
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    • v.6 no.2
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    • pp.63-70
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    • 1994
  • 최근, Courtaulds Fiber Ltd.사에 의해 개발된, 새로운 용제방사(瑢劑紡絲) cellulose fiber인 Tencel에 대한 관심이 고조되고 있다. 이 글에서는, 먼저 Tencel의 고기능 특성을 cellulose섬유의 구조적 성질과 관련지어 언급코져 한다. 다음으로, 중공섬유막(hollow fiber membranes), sponge, 부직포와 bacterial cellulose, 그리고, 그 들 cellulose로부터 유래된 새로운 상품과 그 응용의 광범위한 분야를 서술하고져 한다. 그 외에, cellulose fibers와 fabric에 대한 가능성 후처리기술들의 최근의 동향도 기술하고져 한다. 끝으로, 생분해성 plastic과 super섬유로서의 cellulose의 특성, 그리고 장래 그들의 기술적 전망도 부언하고져 한다.

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Parametric Study on the Morphology of Electrospun Cellulose Web (전기방사 조건이 셀룰로오스 웹 형상에 미치는 영향)

  • Jung, Yeon-Su;Jeong, Young-Jin
    • Textile Coloration and Finishing
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    • v.24 no.1
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    • pp.62-68
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    • 2012
  • Cellulose was electrospun over water collector and the cellulose solution was prepared using N-methyl-morpholine N-oxide/water(nNMMO/$H_2O$). The morphology of electrospun cellulose was investigated by scanning electron microscopy (SEM). SEM images showed that the fiber formation depended on processing parameters such as solution concentration, applied electric field strength, solution feeding rate and temperature of water in coagulation bath. High concentration, low temperature of water bath, and low feeding rate were more favorable to obtain fiber morphology. All the variables affected on the fluidity of the cellulose solution and diffusion of NMMO. Low fluidity and fast diffuision of NMMO was critical for obtaining fiber morphology.