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Dhaka, Bangladesh

Shubhra Q.T.H.,University of Dhaka | Alam A.K.M.M.,Universiti Malaysia Pahang | Beg M.D.H.,Universiti Malaysia Pahang | Khan M.A.,Bangladesh Atomic Energy Commission | Gafur M.A.,PP and PDC
Journal of Composite Materials | Year: 2011

Degradable phosphate glass fiber is a synthetic fiber and silk is one of the strongest natural fibers. In this study, composites are fabricated from PP reinforced with phosphate glass fiber and silk fiber using compression molding. Tensile testing, flexural testing and impact testing are carried out to evaluate the composites mechanical properties. It has been found that silk fiber composites provided higher tensile strength (46 MPa), bending strength (50 MPa), and impact strength (17 kJ/m 2) compared to glass fiber composites which are respectively 39 MPa, 46 MPa, and 8 kJ/m 2. Degradation studies are carried out by accelerated weathering as well as by natural weathering. After weathering, the mechanical properties are evaluated and it has been found that phosphate glass fiber/PP composites degrade more rapidly compared to silk/PP composites. © The Author(s) 2010. Source

Bhuiyan M.K.H.,Bangladesh Agricultural University | Rahman M.M.,Bangladesh University of Engineering and Technology | Mina M.F.,Bangladesh University of Engineering and Technology | Islam M.R.,Universiti Malaysia Pahang | And 2 more authors.
Composites Part A: Applied Science and Manufacturing | Year: 2013

Isotactic polypropylene (PP) nanocomposites with multi-walled carbon nanotubes (MWCNTs) of various diameters (10-50 nm) were fabricated by extrusion and compression-molding techniques and characterized by X-ray diffraction measurements, differential scanning calorimetry, scanning electron microscopy, mechanical test and differential thermal analyses. The pure PP exhibits both the a and b-axes oriented α-crystal, whereas MWCNTs induce the b-axis orientation of the α-crystal along with the formation of minor γ-phase crystal in nanocomposites. Crystallinity, long period of lamellae, tensile strength, tensile modulus (TM) and microhardness (H) of PP considerably change by different loading and sizes of MWCNTs. The estimated values H/TM = 0.09-0.10 for all samples approach the predicted value of 0.10 for polymers. The increase in crystallinity has been demonstrated by both XRD and DSC studies. Mathematical models have been invoked to explain the changes in mechanical properties. An increase in thermal stability of polymer matrix occurs with increasing MWCN-size and loading. © 2013 Elsevier Ltd. All rights reserved. Source

Pathan M.A.K.,University of Dhaka | Siddiquee K.A.M.H.,University of Dhaka | Alam S.,University of Dhaka | Islam O.,University of Dhaka | And 2 more authors.
Journal of Materials Science: Materials in Electronics | Year: 2013

This article presents the deposition and characterization of CdS and CdHgTe thin films for the fabrication of CdHgTe/CdS structure. The growth of CdS and CdHgTe thin films on FTO-coated conducting glass substrates have been performed by chemical bath deposition (CBD) and electrodeposition methods, respectively. The deposition conditions have been optimized for getting better quality layers of CdS and CdHgTe. The grown layers of both CdS and CdHgTe have been characterized by photoelectrochemical cell (PEC) measurement, X-ray diffraction (XRD), scanning electron microscopy (SEM) and UV-vis spectrophotometer. Annealing effect of the deposited films has also been investigated. Finally the fabrication of CdHgTe/CdS structure has been performed and investigated by I-V characteristics. PEC, XRD, SEM and UV-vis spectrophotometer studies reveal that chemically deposited CdS layers are n-type with band gap values vary from 2.29 to 2.41 eV and cubic with (111) preferential orientation, and have spherical grain distributed over the surface. However, electrodeposited CdHgTe layers are p-type with band gap values varying from 1.50 to 1.53 eV and cubic with highly oriented CdHgTe crystallites with the (111) planes parallel to the substrate, and have uniform distribution of granular grains over the surface. The fabricated CdHgTe/CdS structure gave an open-circuit photovoltage and a short-circuit photocurrent of 510 mV and 13 mA/cm2 respectively, under AM 1.5 illumination. © 2012 Springer Science+Business Media, LLC. Source

Siddiquee K.A.M.H.,University of Dhaka | Pathan M.A.K.,University of Dhaka | Alam S.,University of Dhaka | Islam O.,University of Dhaka | Qadir M.R.,PP and PDC
Optik | Year: 2013

CdTe/CdS heterojunction solar cell structure has been fabricated using simple, easy and low-cost methods. To fabricate this structure, CdS and CdTe thin films are deposited onto FTO-coated conducting glass substrates by chemical bath deposition (CBD) and electrodeposition method, respectively. The optimized growth conditions are chosen for both CdS and CdTe films by investigating the optical, structural and morphological properties of both the as-deposited and annealed films. Optical measurement showed that CdS films have higher transmittance and lower absorbance, and CdTe films have lower transmittance and higher absorbance in the near infrared region. The band gap of CdS films is estimated to lie in the range 2.29-2.41 eV and that of CdTe films is in the range 1.53-1.55 eV. X-ray diffraction (XRD) study reveals that CdS and CdTe films are polycrystalline with preferential orientation of (1 1 1) plane. Scanning electron microscopy (SEM) study reveals that both films are smooth, void-free and uniformly distributed over the surface of the substrate. Fabricated CdTe/CdS structure showed the anticipated rectifying behaviour, and the rectifying behaviour is observed to improve due to CdCl2 treatment. © 2013 Elsevier GmbH. Source

Huq T.,Dhaka University of Engineering and Technology | Khan A.,Dhaka University of Engineering and Technology | Noor N.,Dhaka University of Engineering and Technology | Saha M.,Dhaka University of Engineering and Technology | And 3 more authors.
Polymer - Plastics Technology and Engineering | Year: 2010

Jute fiber mat (hessian cloth) reinforced PET-based composites (50% fiber by weight) and E-glass fiber matreinforced PET based composites (50% fiber by weight) were fabricated by compression molding and the mechanical properties tensile strength (TS), tensile modulus (TM), elongation at break (%), bending strength (BS), bending modulus (BM), impact strength (IS) and hardness (Shore-A) of the composites were evaluated and compared. The interfacial properties of the both composites were also compared. Water uptake test and soil degradation test were also investigated. © Taylor & Francis Group, LLC. Source

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