• Title/Summary/Keyword: fibre characteristics

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

  • Law, Ken;Mao, Changbin
    • Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
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    • 2006.06a
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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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Interface and Microstructure Development in Carbon/Carbon Composites

  • Mathur, R.B.;Bahl, O.P.;Dhami, T.L.;Chauhan, S.K.;Dhakate, S.R.;Rand, B.
    • Carbon letters
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    • v.5 no.2
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    • pp.62-67
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    • 2004
  • Performance of carbon-carbon composites is known to be influenced by the fibre matrix interactions. The present investigation was undertaken to ascertain the development of microstructure in such composites when carbon fibres possessing different surface energies (T-300, HM-35, P120 and Dialed 1370) and pitch matrices with different characteristics (Coal tar pitch $SP110^{\circ}C$ and mesophase pitch $SP285^{\circ}C$) are used as precursor materials. These composites were subjected to two different heat treatment temperatures of $1000^{\circ}C$ and $2600^{\circ}C$. Quite interesting changes in the crystalline parameters as well as the matrix microstructure are observed and attempt has been made to correlate these observations with the fibre matrix interactions.

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Variation of Tow Geometry for Polymer Foam-Composite Sandwich Structures during Forming (플리머 포움-복합재료 샌드위치 구조의 성형 중 토우 구조의 변화)

  • Woo Jong Won;Kim Yong Soo;Chang Seung Hwan
    • Proceedings of the Korean Society For Composite Materials Conference
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    • 2004.04a
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    • pp.198-201
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    • 2004
  • This paper aims to investigate the micro-mechanical behaviour of tow geometry with forming pressures and densities of foams during the curing process of plain weave carbon fibre fabric prepregs onto polymer foams. In order to find out and compare deformation patterns between different forming conditions, tow parameters such as amplitude and crimp angle etc. are investigated. From the observation results, geometric difference in the tow architecture with respect to forming conditions and foam characteristics were found. To observe the micro-deformation of the fabric structure, appropriate specimens from carbon fibre-foam sandwich structures are sectioned and observed under the microscope.

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Damage Effect on Glass Fibre Reinforced Plastics under Airflow by a Continuous Wave Laser (연속발진 레이저에 의한 공기 유동에 노출된 유리섬유 강화 플라스틱 손상효과)

  • Lee, Kwang Hyun;Shin, Wan-Soon;Kang, Eung-Cheol
    • Journal of the Korea Institute of Military Science and Technology
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    • v.18 no.3
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    • pp.293-299
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    • 2015
  • We analyzed the damage effect on Glass Fibre Reinforced Plastics(GFRP) under air flow by irradiation of continuous wave near-IR laser. Damage process and temporal temperature distribution were demonstrated and material characteristics were observed with laser intensity, surface flow speed and angle. Surface temperature on GFRP rapidly increased with laser intensity, and the damaged pattern was different with flow characteristics. In case of no flow, penetration on GFRP by burning and flame generation after laser irradiation was appeared at once. GFRP was penetrated by the heat generated from resin ignition. In case of laser irradiation under flow, a flame generated after burning extinguished at once by flow and penetration pattern on GFRP were differently shown with flow angle. From the results, we presented the damage process and its mechanism.

Effect of fibrous diets on chemical composition and odours from pig slurry

  • Mpendulo, Conference Thando;Hlatini, Vuyisa Andries;Ncobela, Cypril Ndumiso;Chimonyo, Michael
    • Asian-Australasian Journal of Animal Sciences
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    • v.31 no.11
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    • pp.1833-1839
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    • 2018
  • Objective: Incorporating high fibre ingredients into pig diets has the potential to reduce odour emissions from of pigs. The current study was carried out to determine effect of diets containing 0, 80 and 160 g/kg of each of lucerne hay, maize cobs and sunflower husks on the chemical characteristics and odours from pig slurries. Methods: Twenty eight pigs averaging $18{\pm}2.0kg$ were kept in individual cages, over four weeks. All pigs were fed ad libitum. Faeces and urine were collected, mixed in a 1:2.3 ratio (w/w), stored and fermented for 16 days in a temperature controlled room at $22^{\circ}C{\pm}2.3^{\circ}C$. The slurry was sampled twice (on day 1 and on day 16) of the fermentation period and analysed for pH, chemical oxygen demand (COD), nitrogen and short chain fatty acids (SCFA) concentration, on wet basis. All samples were tested for odour offensiveness using 18 panelists. A scale of 1 to 5 was used to rank the odour severity, (1 = not offensive, 5 = extremely offensive). Results: Slurry pH and COD varied with fibre source (p<0.05). On day 16, COD for lucerne hay, sunflower husk and maize cobs were 369, 512, and 425 (standard error of the mean = 34.2) mg of oxygen per litre. Total SCFA concentration was higher at day 16 than day 1 (p<0.05). Odour offensiveness varied with fibre source across both incubation periods (p<0.05). Sunflower husks and lucerne hay-based diets were rated as less offensive (mean rank = 2.2) than maize cob diets (mean rank of 4.3) (p<0.05). Conclusion: It was concluded that different fibre sources and incubation period influence chemical composition and odour of the slurry. There is, thereby, a need to incorporate locally available fibrous feeds in the diet of pigs because they have an economical and environmental relevance to pig management.

Biomass Production and Nutritive Potential of Conserved Forages in Silvopastoral Traditional Fodder Banks (Ngitiri) of Meatu District of Tanzania

  • Rubanza, C.D.K.;Shem, M.N.;Ichinohe, T.;Fujihara, T.
    • Asian-Australasian Journal of Animal Sciences
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    • v.19 no.7
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    • pp.978-983
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    • 2006
  • Forages from grazing lands comprise conventional feed resources for ruminants in the tropical region. A study was conducted to assess fodder productivity and nutritive potential of deferred forages of six silvopastoral traditional fodder banks in central northwest Tanzania, traditionally known as Ngitiri. The grazing lands were dominated by low quality increaser grass species: Eragrostis spp., Aristida spp., Urochloa spp., Rottboellia exaltata, Cenchrus spp., Cynodon spp. and Chloris spp., and forbs species. The grazing lands had low vegetative basal cover that varied (p<0.05) from 34.7 to 75%, and low forage biomass productivity that varied (p<0.05) from 0.76 to 3.69 tones (t) dry matter (DM)/ha. The forages contained low crude protein (CP) that varied (p<0.05) from 16 to 27 g/kg DM; and had high fibre contents, which varied (p<0.05) from 702-725, 497-573 and 119-225 g/kg DM for neutral detergent fibre (NDF), acid detergent fibre (ADF) and acid detergent lignin (ADL), respectively. The forages were poorly degraded in sacco, and showed low DM degradability (DMD) characteristics of 74, 473 and 576 g/kg DM for DM washing losses (a), slowly degradable feed fraction (b) and potential degradability, (a+b), respectively; and low DMD at 48 h incubation, which varied from 317-345 g/kg DM, and contained low metabolizable energy (ME), (4.2-4.36 MJ/kg DM). The herbage forages would not meet protein and energy requirements for maintenance and production, which could be reflected through low animal productivity. Further work is needed to assess animal productivity (growth, milk, draft force) from conserved forages in traditional fodder banks in the dry season.

Development of High Sensible Fabrics Using Worsted Yarn Drawing Technology (소모사 연신기술 이용 고감성 직물소재 개발)

  • Kim, Seung-Jin
    • Science of Emotion and Sensibility
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    • v.10 no.4
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    • pp.623-629
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    • 2007
  • Recently, the $"Optim"^{(R)}$ which is the wool fibre with high lustre developed by CSIRO in Australia is imported and commercialized as a high sensible fabrics for garment. But the price of this $"Optim"^{(R)}$ fibre is very high so material demand and supply is not smooth. This study is aiming to develop the drawing technology of the worsted yarn with washable function, lustre and low production cost. For this purpose, drawing yarns are made using developed drawing machine and high sensible fabrics are woven using this yarns, and various physical properties of the fabric specimen are measured and analysed with garment characteristics such as sewability and formability. The final objective of this study is seemed to be achieved by making the high sensible fabrics using drawing worsted yarns with high lustre such as $"Optim"^{(R)}$ fibre.

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Short term bond shear stress and cracking control of reinforced self-compacting concrete one way slabs under flexural loading

  • Aslani, Farhad;Nejadi, Shami;Samali, Bijan
    • Computers and Concrete
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    • v.13 no.6
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    • pp.709-737
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    • 2014
  • Fibre-reinforced self-compacting concrete (FRSCC) is a high-performance building material that combines positive aspects of fresh properties of self-compacting concrete (SCC) with improved characteristics of hardened concrete as a result of fibre addition. To produce SCC, either the constituent materials or the corresponding mix proportions may notably differ from the conventional concrete (CC). These modifications besides enhance the concrete fresh properties affect the hardened properties of the concrete. Therefore, it is vital to investigate whether all the assumed hypotheses about CC are also valid for SCC structures. In the present paper, the experimental results of short-term flexural load tests on eight reinforced SCC and FRSCC specimens slabs are presented. For this purpose, four SCC mixes - two plain SCC, two steel, two polypropylene, and two hybrid FRSCC slab specimens - are considered in the test program. The tests are conducted to study the development of SCC and FRSCC flexural cracking under increasing short-term loads from first cracking through to flexural failure. The achieved experimental results give the SCC and FRSCC slabs bond shear stresses for short-term crack width calculation. Therefore, the adopted bond shear stress for each mix slab is presented in this study. Crack width, crack patterns, deflections at mid-span, steel strains and concrete surface strains at the steel levels were recorded at each load increment in the post-cracking range.

Characteristics of CFRP strengthened tubular joints subjected to different monotonic loadings

  • Prashob, P.S.;Shashikala, A.P.;Somasundaran, T.P.
    • Steel and Composite Structures
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    • v.32 no.3
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    • pp.361-372
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    • 2019
  • Tubular joints are used in the construction of offshore structures and other land-based structures because of its ease of fabrication. These joints are subjected to different environmental loadings in their lifetime. At the time of fabrication or modification of an existing offshore platform, tubular joints are usually strengthened to withstand the environmental loads. Currently, various strengthening techniques such as ring stiffeners, gusset plates are employed to strengthen new and existing tubular joints. Due to some limitations with the present practices, some new techniques need to be addressed. Many researchers used Fibre Reinforced Polymer (FRP) to strengthen tubular joints. Some of the studies were focused on axial compression of Glass Fibre Reinforced Polymer (GFRP) strengthened tubular joints and found that it was an efficient technique. Earlier, the authors had performed studies on Carbon Fibre Reinforced Polymer (CFRP) strengthened tubular joint subjected to axial compression. The study steered to the conclusion that FRP composites is an alternative strengthening technique for tubular joints. In this work, the study was focused on axial compression of Y-joint and in plane and out of plane bending of T-joints. Experimental investigations were performed on these joints, fabricated from ASTM A106 Gr. B steel. Two sets of joints were fabricated for testing, one is a reference joint and the other is a joint strengthened with CFRP. After performing the set of experiments, test results were then compared with the numerical solution in ANSYS Parametric Design Language (APDL). It was observed that the joints strengthened with CFRP were having improved strength, lesser surface displacement and ovalization when compared to the reference joint.