• Title/Summary/Keyword: Fibres

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Flexural behaviour of fibre reinforced geopolymer concrete composite beams

  • Vijai, K.;Kumutha, R.;Vishnuram, B.G.
    • Computers and Concrete
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    • v.15 no.3
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    • pp.437-459
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    • 2015
  • An experimental investigation on the behaviour of geopolymer composite concrete beams reinforced with conventional steel bars and various types of fibres namely steel, polypropylene and glass in different volume fractions under flexural loading is presented in this paper. The cross sectional dimensions and the span of the beams were same for all the beams. The first crack load, ultimate load and the loaddeflection response at various stages of loading were evaluated experimentally. The details of the finite element analysis using "ANSYS 10.0" program to predict the load-deflection behavior of geopolymer composite reinforced concrete beams on significant stages of loading are also presented. Nonlinear finite element analysis has been performed and a comparison between the results obtained from finite element analysis (FEA) and experiments were made. Analytical results obtained using ANSYS were also compared with the calculations based on theory and presented.

Synthesis and mechanical properties of flax fabric reinforced geopolymer composites

  • Assaedi, Hasan S.;Alomayri, Thamer S.;Shaikh, Faiz U.A.;Low, It-Meng
    • Advances in materials Research
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    • v.3 no.3
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    • pp.151-161
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    • 2014
  • Geopolymer composites reinforced with different layers of woven flax fabric are fabricated using lay- up technique. Mechanical properties, such as flexural strength, flexural modulus and fracture toughness of geopolymer composites reinforced with 2.4, 3 and 4.1 wt% flax fibres are studied. The fracture surfaces of the composites are also examined using scanning electron microscopy. The results show that all the mechanical properties of the composites are improved by increasing the flax fibre contents. It is also found that the mechanical properties of flax fabric reinforced geopolymer composites are superior to pure geopolymer matrix. Micro-structural analysis of fracture surface of the composites indicated evidence of various toughening mechanisms by flax fabrics in the composites.

Controlling the Hardness and Tribological Behaviour of Non-asbestos Brake Lining Materials for Automobiles

  • Mathur, R.B.;Thiyagarajan, P.;Dhami, T.L.
    • Carbon letters
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    • v.5 no.1
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    • pp.6-11
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    • 2004
  • In spite of unparalleled combination of essential material properties for brake linings and clutch facings, replacement for asbestos is seriously called for since it is a health hazard. Once asbestos is replaced with other material then composition and properties of brake pad changes. In certain cases hardness of the material may be high enough to affect the rotor material. In this study, hardness of the brake pad has been controlled using suitable reinforcement materials like glass, carbon and Kevlar pulp. Brake pad formulations were made using CNSL (cashew net shell liquid) modified phenolic resin as a binder, graphite or cashew dust as a friction modifier and barium sulphate, talc and wollastonite as fillers. Influence of each component on the hardness value has been studied and a proper formulation has been arrived at to obtain hardness values around 35 on Scleroscopic scale. Friction and wear properties of the respective brake pad materials have been measured on a dynamometer and their performance was evaluated.

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Next Generation Fiber Length Measurement

  • Tiikkaja, Esa;Sopenlehto, Taina
    • Journal of Korea Technical Association of The Pulp and Paper Industry
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    • v.32 no.5
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    • pp.54-59
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    • 2000
  • The next generation fibre size analyser has been developed in Kajaani based on over 15 years experience in fibre measurement. This new FiberLab-analyser can measure fibre length both along the fibre centre line and as projected. The cross-sectional measurements of fibre are in principle similar to the earlier version FiberLab. Measured data are generally displayed in distributions. Some new calculations have been added, for example the fibres cross sectional area and fibre volume index both available as distributions as well. The performance of the FiberLab measurement is verified against the manual microscopic testing. These tests show that the new image analysis-based measurement well matches with the manual methods.

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$C^*$-ALGEBRAS ASSOCIATED WITH LENS SPACES

  • Boo, Deok-Hoon;Oh, Sei-Qwon;Park, Chun-Gil
    • Communications of the Korean Mathematical Society
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    • v.13 no.4
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    • pp.759-764
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    • 1998
  • We define the rational lens algebra (equation omitted)(n) as the crossed product by an action of Z on C( $S^{2n+l}$). Assume the fibres are $M_{ k}$/(C). We prove that (equation omitted)(n) $M_{p}$ (C) is not isomorphic to C(Prim((equation omitted)(n))) $M_{kp}$ /(C) if k > 1, and that (equation omitted)(n) $M_{p{\infty}}$ is isomorphic to C(Prim((equation omitted)(n))) $M_{k}$ /(C) $M_{p{\infty}}$ if and only if the set of prime factors of k is a subset of the set of prime factors of p. It is moreover shown that if k > 1 then (equation omitted)(n) is not stably isomorphic to C(Prim(equation omitted)(n))) $M_{k}$ (c).

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Four New Species of Dictyoceratid Sponges (Demospongiae) from Korea

  • Lee, Kyung-Jin;Sim, Chung-Ja
    • Animal cells and systems
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    • v.11 no.1
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    • pp.55-60
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    • 2007
  • Four new species, Semitaspongia jejuensis, Scalarispongia regularis, S. nigra and Dysidea violata are described from Jejudo, Korea. They were collected from 15 m depth by SCUBA diving and from intertidal area by hand. Semitaspongia jejuensis n. sp. is easily distinguished from other Semitaspongia species in growth form, conules, colour, skeletal structure, diameter of fibre and habitat. Scalarispongia regularis n. sp. is very close to S. scalaris (Schmidt, 1862) in skeletal structure, but S. scalaris has longer conules, larger meshes, longer distance between primary fibres, and highly developed subdermal canal system. Scalarispongia nigra n. sp. is very close to S. regularis in skeletal structure but can be easily distinguished by its black colour of external surface and growth form. Dysidea violata n. sp. is similar with D. ethria (Laubenfels, 1936) in sponge appearance, but D. etheria is clearly defined by its blue colour and thickness of fibre.

Behavior of fibre reinforced cementitious material-filled steel tubular columns

  • Kharoob, O.F.;Taman, M.H.
    • Steel and Composite Structures
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    • v.23 no.4
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    • pp.465-472
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    • 2017
  • This paper presents an experimental study, investigating the compressive behavior of glass-fibre reinforced and unreinforced cementitious material-filled square steel tubular (GFCMFST and CMFST) columns. The specimens were manufactured by using high performance cementitious materials without using coarse aggregate. The influence of adding glass-fibres to the mix on the behavior of both axially and eccentrically loaded columns is considered. It was found that adding glass fibre improvesthe confinement behavior, the axial compressive strength, the stiffness and the toughness of both axially and eccentrically loaded columns. The compressive strength of axially loaded columns is compared with strength predictions according to EC4 and the AISC specification. It was found that the design predictions according to EC4 and the AISC codes provide conservative results for CMFST and GFCMFST columns. Alternatively, the axial load-bending moment interaction diagrams specified in theEC4 are conservative for the eccentrically tubular CMFST and GFCMFST tested columns.

Histamine Signaling Pathway in Sensory Neurons is Similar to Bradykinin

  • Lee, Sang-Hee;Koo, Jae-Yeon;Kim, Sang-Sung;Lee, Jung-Youn;Cho, Ha-Won;Kim, Byung-Moon;Oh, Uh-Taek
    • Proceedings of the PSK Conference
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    • 2003.04a
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    • pp.192.1-192.1
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    • 2003
  • Histamine is found in most tissues of the body and activates polymodal nociceptors via unmyelinated afferent C-fibres. We have demonstrated that bradykinin. acting at B2 bradykinin receptors. excites sensory nerve endings by activating capsaicin receptors via production of 12-lipoxygenase metabolites of arachidonic acid in dorsal root ganglion. Histamine is known to the activator of phospholipase A2- arachidonic acid pathway via a G-protein- coupled H1 receptor. (omitted)

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A numerical study on vibration behavior of fiber-reinforced composite panels in thermal environments

  • Al-Toki, Mouayed H.Z.;Ali, Hayder A.K.;Ahmed, Ridha A.;Faleh, Nadhim M.;Fenjan, Raad M.
    • Structural Engineering and Mechanics
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    • v.82 no.6
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    • pp.691-699
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    • 2022
  • This paper is devoted to the presentation of a numerical study on vibration behavior of composite panels reinforced by glass fibres and carbon nanotubes (CNTs) subjected to thermal environments. The effect of temperature variation has been included as thermal load acting on in-plane direction of the panel. To model the composite material, a micromechanical model which contains random dispersion of nanotubes and single-direction fibers has been selected. The geometry of the panel has been considered to have a single curveture along its width. Based on the above assumptions, the governing equations have been derived by using thin shell theory capturing the panel curveture and also nonlinear deflections. Finally, the panel dependence on various factors such as the curveture, nanotube amount, fiber volume, fiber direction and temperature variation has been researched.

USE OF FIBREDRAIN IN DREDGED CLAY RECLAMATION PROJECT

  • Lee, S.L.;Yong, K.Y.;Soehoed A R
    • Proceedings of the Korean Geotechical Society Conference
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    • 2001.11a
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    • pp.96-109
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    • 2001
  • Land was reclaimed at the waterfront in the Pluit area of Jakarta for a 90ha residential-cum-recreational development. The reclamation works involve construction of permanent and temporary dykes, fill placement, soil improvement, dredging of internal canals and marina, and construction of canal revetment. The site lies on 16m to 18m thick soft seabed deposits. Settlement of the reclaimed areas will result as a consequence of consolidation of the soft underlying sediments. In order to reduce post-construction settlement to within acceptable levels, a system of vertical drains and preloading was adopted. This paper describes the use of Fibredrain, a prefabricated vertical drain made of jute and coir fibres developed at the National University of Singapore, in the soil improvement works and a secondary use in the construction of perimeter dykes for the reclamation works. The construction of the perimeter dyke must be carried out in such a way that slope stability is on ensured. Bamboo rafts and bamboo clusters with Fibredrain inserted, and stage construction were employed to improve stability during the dyke formation for the Pantai Mutiara project.

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