• 제목/요약/키워드: Fibres

검색결과 276건 처리시간 0.021초

A Novel Technique for Characterizing the Influence of Refining Energy on the Mechanical Properties of TMP Fibres

  • Law, Ken;Mao, Changbin
    • 한국펄프종이공학회:학술대회논문집
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    • 한국펄프종이공학회 2006년도 PAN PACIFIC CONFERENCE vol.1
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    • pp.141-146
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    • 2006
  • Mechanical fibres are commonly characterized by measuring their length distribution and freeness. These parameters, however, do not adequately characterize the influence of refining on their mechanical properties. In this work we conducted multiple compression on fibre mats prepared from different length fractions (Bauer McNet fractions) to generate stress-strain curves from which several quality parameters can be derived such as modulus, stress and toughness. We found that these characteristics of fibre are strongly influenced by the refining energy used to produce pulp; fibres of similar length exhibit different mechanical properties depending on the refining energy6 consumption.

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효소처리에 의한 제지적성 개선

  • 김형진;조병묵
    • 한국펄프종이공학회:학술대회논문집
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    • 한국펄프종이공학회 2000년도 춘계학술발표논문집
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    • pp.39-46
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    • 2000
  • In pulp and papermaking process, enzymatic treatment of pulp fibres has been a topic of increasing interest in last decade. Lots of patents, papers and research reports were published on the application of enzymes in the fields of enzymatic bleaching, deinking, slime control, pitch control, waste water treatment and fibre modification. Cellulase and hemicellulase are the principal enzymes used for the modification of fibre property. This study was carried out for determinating the behaviors of enzyme to pulp fibres. A commercial enzyme, Denimax BT which is consisted with cellulase and hemicellulase, was treated to the kraft pulp produced from domestic hardwood mixtures. Results were mainly concentrated on the behaviors of freeness, drainability and fines content of fibres, and physical properties of paper with enzyme treatment. The freeness levels and dewatering ability were developed, and the fines contents were decreased. The creation of fines were controlled by the method of pre-enzyme treatment prior to fibre beating. The mechanical strength of paper, like tensile, burst, tear strength and folding endurance, were remarkably improved by the pre-enzyme treatment.

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A Study and Investigation on the Influence of Static and Dynamic Loading on the Properties of Handmade Persian Carpet (I) - The Effect of Static Loading -

  • Mirjalili S. A.;Sharzehee M.
    • Fibers and Polymers
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    • 제6권2호
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    • pp.139-145
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    • 2005
  • The paper reports the physical and mechanical properties of hand-woven carpets, which have been put under static force. Two groups of wool fibres, from two parts of Iran, were prepared to spin pile yams for the carpets. Each group of the fibres included both conventional and tanned wool. Then two yam counts, $N_m$ = 4/2 and 6/2, were spun for two different knot densities. After weaving the carpets, they were put under static force and their thickness variations were measured and plotted against time, in logarithm scale. The resiliency of the carpets piles after eliminating the static force, were measured and plotted against time, in logarithm scale, too. The results were compared to each other and analysed with respect to parameters such as the type and quality of the wool fibres as well as knot density of the carpets.

A New Species in the Family Irciniidae(Demospongiae: Dictyoceratida) from Korea

  • Sim, Chung-Ja;Lee, Kyung-Jin
    • Animal cells and systems
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    • 제6권4호
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    • pp.283-285
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    • 2002
  • Sponges of the family Irciniidae are poorly known in Korean waters. This paper describes a new species of new genus, Bergquistia coreana n. sp. in the family Irciniidae (Demospongiae: Dictyoceratida) from Jejudo Island, Korea from 1998 to 1999. Bergquistra n. gen. is characterized by extremely simple fasciculated and uncored primary fibres. However, in the choano-somal region, primary fibres are made of wider clear web. Secondary fibres form a very thin regular uncored network. The sponge surface has thick and regular conules. The colour is beige throughout the sponge, and the texture is slightly hard and compressible. Thickness of filament is variable.

Shear strength of full-scale steel fibre-reinforced concrete beams without stirrups

  • Spinella, Nino
    • Computers and Concrete
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    • 제11권5호
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    • pp.365-382
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    • 2013
  • Although shear reinforcement in beams typically consists of steel bars bent in the form of stirrups or hoops, the addition of deformed steel fibres to the concrete has been shown to enhance shear resistance and ductility in reinforced concrete beams. This paper presents a model that can be used to predict the shear strength of fibrous concrete rectangular members without stirrups. The model is an extension of the plasticity-based crack sliding model originally developed for plain concrete beams. The crack sliding model has been improved in order to take into account several aspects: the arch effect for deep beams, the post-cracking tensile strength of steel fibre reinforced concrete and its ability to control sliding along shear cracks, and the mitigation of the shear size effect due to presence of fibres. The results obtained by the model have been validated by a large set of experimental tests taken from literature, compared with several models proposed in literature, and numerical analyses are carried out showing the influence of fibres on the beam failure mode.

Seven new species of genus Dysidea (Demospongiae: Dictyoceratida: Dysideidae) from Korea

  • Young A Kim;Kyung Jin Lee
    • Journal of Species Research
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    • 제12권1호
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    • pp.38-47
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    • 2023
  • Seven new species of genus Dysidea (Demospongiae: Dictyoceratida: Dysideidae) are described from Jejudo Island and Geomundo Island, Korea. These new species are compared with other reported species in fibre structure and arrangement, and cored detritus. Dysidea reticulum n. sp. is similar to D. glavea in skeletal structure but differ in sponge shape. Dysidea simplex n. sp. is close to D. glavea with loosely arranged skeletal structure but fibres in this new species are not cored with large sands. Dysidea pyeongdaensis n. sp. is characterized by tube-like surface oscules open toward the sandy bottom. Dysidea capillus n. sp. is similar to D. dokdoensis in skeletal structure, but differs in long surface conules. Dysidea mukriensis n. sp. is close to D. corallina in distinct dense surface conules, but differs in sponge shape and skeletal structure. Dysidea membrana n. sp. is similar to D. sabulum in primary fibres cored with numerous large sands, but differs in sponge surface conules and secondary fibres. Dysidea chujaensis n. sp. is unique in the sponge shape and skeletal structure.

인천시 고잔동에서 제기된 유리섬유에 의한 건강피해 역학 조사 (Health Assessment for Glass Fibre Landfill at Gozan-dong, Inchon)

  • 조수헌;주영수;김경렬;이강근;홍국선;은희철;송동빈;홍재웅;권호장;하미나;한상환;성주헌;강종원
    • Journal of Preventive Medicine and Public Health
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    • 제30권1호
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    • pp.77-101
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    • 1997
  • In September 1994, residents of Gozan-dong, Incheon City, made a petition to the government about their health problems which might be caused by previous glass fibre landfill nearby 'H' company. In february 1995, at regular academic meeting of occupational and environmental medicine, a research team of 'D' University presented that they had found glass fibres in groundwater of the area through their survey. They were suspicious of probable association between ingestion of groundwater contaminated with glass fibres and skin tumors among residents. A joint research team was formed and carried out the survey of environment concerning groundwater and its glass fibre existence, and health assessment of residents in the area and industrial workers of 'H' company during May to November, 1995. Analysis of groundwater flow system indicates that the flow lines from the glass fibre landfill pass through or terminate at the 6 houses around the landfill. This means that the groundwater of the 6 houses around the glass fibre landfill could be affected by some possible contaminants from the landfill, but the groundwater quality of the other houses was irrelevant to the landfill. The qualitative and qualitative analyses for glass fibres in 54 groundwater samples including those from the nearby 6 houses, were carried out using SEM equipped with EDS, resulting in no evidence for the presence of glass fibres in the waters. Major precipitates, formed in waters while boiling, were identified as calcium carbonates, in particulary, aragonites in needle form. The results of health assessments of 889 residents in Gozan-dong, participated in this study, showed statistically significant differences in past medical histories of skin tumor and respiratory disease between the exposed group (31 persons who inhabited in 6 houses around the landfill) and the control group, but no significant differences in past medical histories of other diseases, such as cancer mortality, current gastroscopic findings, current skin diseases and respiratory diseases, etc. Also, we could not prove any glass fibres in excised specimens of 9 skin tumors in both groups and there were no health problems possibly associated with glass fibres in employees of the 'H' company. After all, we could not authenticate the association, raised by prior investigators, between groundwater streams, assumedly contaminated with glass fibres or not, and specific disease morbidities or common disease/symptom prevalences. That is, we could not find any glass fibres in groundwater as the only exposure factor of this study hypothesis, and there were not enough certain evidences such as increasing disease prevalences, for examples, skin, respiratory and gastrointestinal diseases etc, possibly related to glass fibre exposure, in exposed group. As a matter of course, the conditions for confirming causal association, for example, strength of the association, consistency of the association, specificity of the association, temporality of the association and dose-response relationship etc, have not been satisfied. In conclusion, we were not able to certify the hypothesis that contamination of groundwater with glass fibres might cause any hazardous health effects in residents who used it for drinking.

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A New Species of the Genus Narrabeena (Demospongiae: Dictyoceratida: Thorectidae) from Korea

  • Kim, Hye-Ri;Sim, Chung-Ja
    • Animal Systematics, Evolution and Diversity
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    • 제26권1호
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    • pp.83-86
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    • 2010
  • A new species of the family Thorectidae, Narrabeena nigra n. sp. is described. This species was collected from the front of Songaksan, Daejeong-eup, Seogwipo-si, Jejudo Island, Korea. Narrabeena nigra n. sp. is similar to Narrabeena lamellate (Bergquist, 1980) with uncored primary and secondary fibres and an unarmoured surface. They differ in growth form, colour, and fibres.

A New Sponge of the Genus Smenospongia (Dictyoceratida: Thorectidae) from Gageodo Island, Korea

  • Lee, Kyung-Jin;Sim, Chung-Ja
    • Animal cells and systems
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    • 제9권1호
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    • pp.9-11
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    • 2005
  • A new species of the genus Smenospongia (Dictyoceratida, Thorectidae), S. coreana n. sp., is described from Gageodo Island, Korea. This new species is readily distinguished from the other species of Smenospongia by the un-lobated growth forms and un-crowded primary fibres. S. aurea and S. lamellata are no distinction between primary and secondary elements, but this species is easily distinguished from them. The matrix easily derived from the fibres. This species has five sesterterpenes, three scalaranetypes and two linear furanosesterterpenes, in chemical compounds.

PTT/Tencel/Cotton 친환경 MVS 혼방사 편성물의 물성에 관한 연구 (II) (Wearing Performance of Garment for Emotional Knitted Fabrics Made of PTT/Tencel/Cotton MVS Blended Yarns (II))

  • 김현아
    • 한국의류산업학회지
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    • 제17권6호
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    • pp.1020-1029
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    • 2015
  • This paper investigated the wearing performance of knitted fabrics made of air vortex yarns using PTT/tencel/cotton fibres in comparison with ring and compact yarns for emotional garment. Wicking property of knitted fabric made of MVS yarns was worse than those by ring and compact yarns, however, drying property of knitted fabric made of MVS yarns was better than those by ring and compact yarns, which was explained as more water vapor transport due to larger openness between fibres in the MVS yarns than those in the ring and compact yarns. Thermal conductivity of knitted fabric made of MVS was lower than those of ring and compact yarns and maximum heat flow(Qmax) at the transient state of MVS knitted fabric was lower than those of ring and compact yarns, which may be attributed to MVS yarn structure that has parallel fibres in the core part of the yarn and fasciated fibre bundles on the sheath part with roughness on the yarn surface. However, pilling of MVS knitted fabric was better than those by ring and compact yarns, which was caused by less and shorter hairy fibres protruded from MVS yarn surface than those of ring and compact yarns. It was observed that tactile hand of MVS yarn knitted fabrics was stiffer than those of ring and compact yarns knitted fabrics. It was explained by low extensibility and compressibility and high bending and shear rigidities of the MVS yarn knitted fabrics, which resulted in bad wearing performance of MVS knitted fabric.