bluuebunny/crossref_metadata_2025 huggingface dataset:
A Socratic E-Learning Approach
Authors: Snaprud Mikael H. , Helmikstøl Gerd Reidun
Published: June 2015

Using questions to elaborate knowledge, is widely used in learning today. In this position paper we argue that there are new benefits to reap from using ICT in a learning process based on the Socratic method, and outline practical steps of an approach for collaborative e-learning using questions.
Fabrication of Aluminum Interdigitated Electrode for Biosensor Application Using Conventional Lithography
Authors: Farehanim M.A. , Hashim U. , Soin Norhayati , Azman A.H. , Norhafizah S. , Fatin M.F. , Ramzan Mat Ayub
Published: June 2015

A simple technique for the fabrication of interdigitated electrode (IDEs) using conventional lithography was presented. A top-down simple lithography approach was used to fabricate a set of Interdigitated electrodes were patterned with aluminum metal. Silicon dioxide serves to isolate the electrode from the substrate. A chrome mask was proposed to complete this work. In this work, the proposed method was experimentally demonstrated by fabricating the IDEs structure 4-5μm, approximately. The dimensions of structure were determined by using scanning electron microscopy (SEM). It is a simple, easy-to-use and cost effective method and does not require complicated micro-lithography process for fabricating desired microelectrode in reproducible approach.
Electrical Properties of Nano-TiO2 Thin Film Prepared by Sol-Gel Precipitation Route Using Two-Point Probe Method
Authors: Muaz A.K.M. , Hashim U. , Nadzirah Sharipah , Al-Mufti M. Wesam , Ibrahim Fatimah , Kwai Lin Thong
Published: June 2015

Titanium dioxide (TiO2) thin films were successfully prepared using the use of titanium isopropoxide as a precursor with an ethyl alcohol solution at a molar ratio 1.0:10 by sol-gel precipitation method at room temperature (~24°C). The gel solution was formed after mixed for different times. TiO2 thin films were deposited on the P-type <100> silicon substrates by spin coating technique. In this paper, we report the comparison between conductivity and resistivity of TiO2 thin films prepared at different heat treatment. The results show that the electrical properties of TiO2 thin film were changed with the changes of heat treatment. The results exhibit that the resistance tends to decline as the annealing temperature increases. The most conductive sample is 700°C followed with 500°C, 300°C, 100°C and least conductive is as-deposited film. From the I-V curve, the graph giving a Schottky contact properties.
SERS-Modeling in Molecular Sensing
Authors: Asing Asing , Ali Md Eaqub , Abd Hamid Sharifah Bee
Published: June 2015

Surface enhanced Raman spectroscopy (SERS) is an ultrasensitive vibrational spectroscopic technique that useful tools in detecting biomolecules at near or on the surface of plasmonic nanostructures. Unique physicochemical and optical properties of noble metal nanostructures allow the assimilation of biomolecular probes and exhibit distinctive spectra, prompting the development of a plethora of biosensing platforms in molecular diagnostics. In SERS biosensor, signal to noise ration such as recognition and transducer elements that provide fingerprint spectrum at the lower limit of detection with specific binding or hybridized event, increasing reliability and sensitivity. Since the localized surface plasmon resonance (LSPR) of nanoparticle lies at the heart of SERS. It is essential to control all of the LSPR influencing factors in highly sensitivity signal strength that ensures reproducibility of SERS signals. SERS active substrates, transducer elements, metal surfaces modification, interparticle spacing, dielectric environment and selection of biorecognition molecules contribute in SERS signal strength. Modified metal structure with bioprobe and Raman reporter molecules provides a strong signature fingerprints that surely contribute to noble biosensor structural designing. We reviewed here ideal fabrication of nanostructure for SERS application in molecular sensing research fields.
Preparation and Characterization of Pt Coated on Al-Doped ZnO Nanorods Thin Film at Different Thicknesses
Authors: Wahida M.N. , Mamat M.H. , Yusoff A.A.M. , Rusop Mohamad
Published: June 2015

The surfaces of Al-doped ZnO nanorods thin films were coated with platinum (Pt) by five different thicknesses; 5 nm, 10 nm, 15 nm, 20 nm and 25 nm. The resistivity decreases while the conductivity increases, proving the trend in current-voltage measurement. The transmittance spectra show diverse result. Meanwhile the 5 nm coating sample shows highest absorbance characteristic among others. This absorption coefficient was calculated from transmittance obtained by UV-vis spectra, indicating that they have high UV absorbance properties at wavelengths below 400 nm. Absorption rate might be due to the thickness of Pt that allows the penetration of UV for more oxygen absorption.
Physical and Electrical Properties of Nano-Structured Sn-Doped Zinc Oxide Thin Film at Different Sn Doping Concentrations
Authors: Saurdi I. , Mamat Mohamad Hafiz , Shafura A.K. , Malek Mohd Firdaus , Ishak A. , Rusop Mohamad
Published: June 2015

In this paper, the nanostructured Sn-doped ZnO thin films were prepared by Spin coating technique on glass substrates at various Sn doping of 0, 1, 1.5, 1, 2.0 and 3 at.%. The structural, optical and electrical properties were characterized by field emission scanning electron microscopy (FESEM), X-Ray Diffraction (XRD), UV-Vis-NIR and I-V measurement, respectively. The surface morphology reveals that the average particle size of nanostructured Sn-doped ZnO thin films decreased as the Sn concentrations increased. The results show all films are transparent in the visible region with average transmittance above 88%. Meanwhile, the resistivity of Sn-soped ZnO thin films was decreased when the Sn concentrations increased. Among all of Sn-doped ZnO thin films, the thin films doped with 2 at.% shows the optimum properties of average resistivity and transmittance were 7.7 x 102 Ω.Cm and 96%, respectively.
In-House Development of Shear Horizontal Acoustic Waves Based Sensitive Sensors for Bacterial Pathogens Detection
Authors: Ten Seng Teik , Hashim Uda , Sudin Ahmad , Liu Wei Wen , Foo Kai Loong , Voon Chun Hong , Wee F.H. , Lee Yeng Seng , Salleh N.H.M. , Hisham Hashim , Nazwa Taib
Published: June 2015

Surface acoustic wave can be generated at the free surface of an elastic solid. Interdigital transducers (IDTs) are fabricated on the piezoelectric substrate surface that will act as electrical input and output port. When appropriate AC voltage stimulus is applied to the input transducer, surface acoustic wave will be produced. The output or receiving port will detect the incident surface acoustic wave and convert it back to a suitably filtered electrical once. For this property, surface acoustic based devices were initially developed for the telecommunication purpose such as signal filters and resonators. SAW based devices have been modified to be sensors later on from for gas detections and have been moving towards biological detections recently for its ultra-sensitivity to surface perturbation. The main component of this device is the IDTs. Recently, there are several methods to produce IDTs; Ultra-Violet (UV), deep UV lithography, Electron beam (e-beam) lithography and X-ray lithography. Although, these methods can produce very fine and accurate electrodes in term of submicron size but the costs are extremely expensive. Thus, this paper will discuss the conventional CMOS method which is much more economical to produce the applicable IDTs for the bacterial pathogens sensing purpose. Shear horizontal surface acoustic wave (SHSAW), one of the SAW based types is used in this paper as it is most suitable for the liquid based application as it has the advantage of acoustic energy is not being radiated into liquid.
Preparation, Morphological and Structural Properties of Nanocrystalline Ni-Mg Cobalt-Ferrite Synthesized by the Co-Precipitation Method
Authors: Rosnan Rizuan Mohd , Othaman Zulkafli , Ati Ali A.
Published: June 2015

The present study describes the morphological and structural characterization of nanosized Ni-Mg cobalt-ferrites. The nominal compositions Co0.5Ni0.5−xMgx Fe2O4 in the range (0.0 ≤ x ≤ 0.5) have been synthesized by co-precipitation method. These nanopowder products were sintered in furnace at temperature of 900°C for 10 hour with a heating rate of 5°C/min to obtain these ferrites. The prepared nanoferrites were characterized by X-ray diffraction (XRD) and field emission scanning electron microscopy (FESEM) with varying concentration (x) in the composition of the prepared nanoferrites. XRD confirmed formation of single phase spinel ferrite with average crystalline size in the range of 34–37 nm. Lattice constant (a) increases with an increase of Mg concentration. Further information about the structure and morphology of the nanoferrites was obtained from FESEM and results are in good agreement with XRD.
Titanium Containing Aluminophosphate Molecular Sieve for Oxidation of Styrene
Authors: Endud Salasiah , Roslan Nurliana , Ramli Zainab , Lintang Hendrik O.
Published: June 2015

Microporous aluminophosphate (AlPO-5) and titanium aluminophosphate (TAPO-5) molecular sieves, which are zeolite-like materials have been synthesized by direct hydrothermal method using two different templates; triethylamine (TEA) as organic base and tetraethylammonium hydroxide (TEAOH) as alkali base. XRD patterns confirmed that the TAPO-5 catalysts are identical with AFI structure but the crystallinity of the catalysts had decreased after the incorporation of titanium into the framework. Besides that, characterization of TAPO-5 catalysts using DRUV-Vis confirmed the coordination of titanium species and this evidenced also supported by the result 27Al MAS NMR. Catalytic performance of the TAPO-5 catalysts was tested in the oxidation of styrene to produce benzaldehyde and phenylacetaldehyde in the presence of hydrogen peroxide as oxidant. TAPO-5 catalysts showed higher activity in styrene oxidation compared to AlPO-5. Keywords: zeolite; aluminophosphate; titanium; organic template; styrene
Fabrication of Nanostructure-Based Copper Oxide Biosensor
Authors: Azmi M. Safwan , Nadzirah Sharipah , Hashim Uda
Published: June 2015

The purpose of this paper is to give a review of the fabrication of nanostructure-based copper oxide biosensor. This paper briefly covers processes from silicon wafer cleaning, oxidation process, silicon nitride deposition, aluminum metal deposition, pattern transfer, copper oxide sol-gel preparation and coating and lastly IV testing with the results expected from the completed device.Keywords: Nanostruture, copper oxide, biosensor, sol-gel, current-voltage testing.
Morphological Characterization of Fabricated Aluminum Interdigitated Electrodes on Silicon Substrate
Authors: Azmi M. Safwan , Nadzirah Sharipah , Hashim Uda
Published: June 2015

The purpose of this paper is to study the morphological characterization of aluminum interdigitated electrodes (IDE) of different gap sizes on silicon substrate. The electrodes were fabricated using standard photolithography process and were done so with sizes of 12 μm, 10 μm and 7 μm. The electrodes were morphologically characterized using scanning electron microscope (SEM) and high-powered microscope (HPM).Keywords: morphological, interdigitated electrodes, aluminum
High Yield Preparation of Graphene Oxide Film Using Improved Hummer’s Technique for Current-Voltage Characteristic
Authors: Low F.W. , Lai Chin Wei , Abd Hamid Sharifah Bee , Chong S.W. , Liu Wei Wen
Published: June 2015

Nowadays, graphene (Gr) is one of the most promising materials in the field of nanoscience and nanotechnology and has attracted extensive attention in variety of applications, such as solar energy, environmental management, sensor, electronic device as well as energy storage and conversion. From a theoretical point of view, Gr provides the ultimate two-dimensional (2D) model of a catalytic support with sp2 hybridized carbon atoms. Its unique physical, chemical and mechanical properties are outstanding, and could allow the preparation of this composite material with unprecedented characteristics, such as superior electron mobility, good conductivity, excellent transparent property and high chemical stability. These unique characteristics inherent to well-defined 2D Gr are suitable for facilitating a wide range of transformations and may offer extraordinary potential in the design of novel catalytic systems. Herein, a simple and well-controllable Improved Hummer’s method was presented for the first time by controlling it’s stirring duration for high yield production of GO (62.50%). Based on our preliminary results, it was found that large amount of oxygen functional groups appeared after the conversions of graphite into graphene oxide (GO) by applying the vigorous stirring speed for 72 hours continuously. The main reason mainly attributed to the improvement of the mass transfer rate of oxygen molecules during the oxidation reactions; thus, high yield of GO could be achieved under this experimental condition. In addition, the resultants GO exhibited higher short-circuit currents with 290 μA compare to short circuit of Gr with 70 μA under light simulation condition.
Structural and Optical Properties of ZnO Nanotetrapods Deposited by Thermal Chemical Vapor Deposition with Different Gas Flow Rate
Authors: Azhar Najwa Ezira Ahmed , Shariffudin Shafinaz , Rosli Aimi Bazilah , Shafura A.K.S. , Rusop Mohamad
Published: June 2015

ZnO nanotetrapod with different oxygen flow rate was prepared by thermal chemical vapor deposition. We have successfully deposited ZnO nanotetrapod on synthesis Zn powder using double furnace with argon (Ar) and oxygen (O2) gas as source material. In this study, we report the effect of different gas flow rate (5 sccm to 15 sccm) on structural and optical properties of the ZnO nanotetrapod. The morphology of ZnO nanotetrapods were analyzed by field emission scanning electron microscope (FE-SEM). It exhibits the length of the nanotetrapods arm decrease with increased of flow rate and diameter of nanotetrapod in range 30 nm to 90 nm. The optical properties were determined through XRD and photoluminescence with 2θ (30o to 80o) and wavelength 350 nm to 620 nm respectively. PL spectra show that the UV emission centred at 380 nm while yellow-orange emission centred at 540 nm.
Synthesized of Highly Sensitive Tin (IV)-Doped Zinc Oxide Humidity Sensor
Authors: Ismail Ahmad Syakirin , Malek Mohd Firdaus , Abdullah Muhammad Amir Ridhwan , Mamat Mohamad Hafiz , Rusop M.
Published: June 2015

High sensitivity Tin (IV) (Sn) - doped zinc oxide (ZnO) humidity sensor was deposited using sol-gel immersion method. The Sn-doped sample was deposited on glass substrate and undoped sample was also prepared to seem the improvement made through doping process. The analyses showed that the sensor’s morphology has become more porous and having lower average diameter of nanorods, high conductivity and higher response, recovery time, and sensitivity. The sensitivity of the sensor increased from 2 to 4 by doping with Sn.
The Effect of Au-Seeded Thickness to the Morphology of ZnO Nanostructures Obtained by Mist-Atomization on Heated Substrates
Authors: Abdullah Nurul Afaah , Asib N.A.M. , Aziz Aadila , Rusop M. , Mohamed Ruziana , Khusaimi Zuraida
Published: June 2015

ZnO nanostructures were obtained by mist-atomisation technique. Nanostructured ZnO can be grown in aqueous solution of zinc nitrate hexahydrate as precursor solution with the addition of stabilizer hexamethylenetetramine (HMTA). ZnO nanostructures deposited by mist-atomisation, with applied heat from the glass substrates’ downside. Firstly, the glass substrates were seeded by Au with different thickness of 0 (non-seeded), 6, and 12 nanometer (nm). The growth of ZnO on different Au-seeded thickness is studied. The optical properties of ZnO nanostructures were examined by Ultraviolet-Visible (UV-Vis) spectroscopy. The morphology of the ZnO thin films obtained was studied by FESEM. FESEM micrographs shows different nanostructures formed on different thickness of Au-seeded glass. UV-vis spectra of ZnO nanostructures display high absorption in the UV region and high transparency in the visible region. There is improvement in UV absorption for ZnO growth on 6nm Au-seeded compared to non-seeded and 12 nm Au-seeded glass due to imperfect alignment of ZnO nanostructures.
Fabrication of Micro-Gap Structure by Reactive Ion Etching Technique (RIE) for Future Reproductivity of Nanogap Biosensor
Authors: Humayun Q. , Hashim U.
Published: June 2015

The important role of reactive ion etching (RIE) technique is to etch the semiconductor surface directionally. The purpose of the current research is to fabricate polysilicon micro-gap structures by RIE technique for future biosensing application. Therefore zero-gap microstructure of butterfly topology was designed by using AutoCAD software and finally the designed was transferred to commercial chrome glass photomask. Ploysilicon wafer samples were selected to achieve high conductivity during electrical characterization measurement. The fabrication process starts from samples resist coating and then by employing photolithography through chrome glass photomask the zero-gap pattern of butterfly topology was transferred to resist coated sample wafer followed by resist stripping from exposed area and finally by reactive ion etching (RIE) technique the open area of polysilicon was etched directionally at different etching time to fabricate micro-gap structure on wafer samples. The spacing of fabricated micro-gap structures will be further shrink by thermal oxidation (size reduction technique) until to nanosize gap spacing. The proposed nanospacing gap will definitely show the capability to detect the bio molecule when inserted into the gap spacing.
The Effects of Fly Ash Addition on the Properties of Porous Clay-Fly Ash Composites
Authors: Chan W.H. , Mohd Noor Mazlee , Ahmad Zainal A. , Jamaludin Shamsul Baharin , Ishak Mohd Azlan Mohd
Published: June 2015

Porous ceramics have a great potential to be utilised for adsorption purposes. In this study, the effects of fly ash addition in porous clay-fly ash composites via polymeric replica technique were investigated. The results shows that the fly ash addition from 1:1 to 1:1.5 (clay:fly ash ratio) have promoted favourable results for compressive strength (0.228-0.284 MPa), porosity (97.0-97.4 percent) and densities (2.358-2.439 g/cm3) respectively. When the fly ash ratio addition was increased up to 1:2 (clay:fly ash ratio), the compressive strength (0.18 MPa) reduced significantly. However, the density was bounced back to 2.404 g/cm3 at the same ratio. This condition was occurred due to high concentration of mineral contents when fly ash addition has increased. Based on XRD pattern, the intensities between mullite and quartz was reduced when clay:fly ash ratio increased from 1:1 to 1:1.5. As the clay:fly ash ratio was increased up to 1:2, the intensities of mullite and quartz showed an increment in XRD pattern. However, there were only 4 percent of changes in porosity when the fly ash addition was 1:2 (clay: fly ash ratio). The reticulated structures of porous clay-fly ash composites were similar although fly ash addition has increased from 1:1 to 1:2.
The Effect of Micron-Size Silicon Additions on Microstructure, Microhardness and Thermal Properties of Sn-Cu-Ni Solder Alloy
Authors: Izwan Ramli Mohd Izrul , Saud Norainiza , Mohd Salleh Mohd Arif Anuar , Derman Mohd Nazree , Said Rita Mohd , Nasir Norhayanti
Published: June 2015

The effect of Si particulate addition on the commercial Sn-Cu-Ni solder system (SN100C) solder alloy has been investigated. The SN100C/Si composite solder was fabricated via powder metallurgy (PM) technique. In this study five different Si composition chosen were (0 wt. %, 0.25 wt. %, 0.5 wt. %, 0.75 wt. %, and 1.0 wt. %). The results indicated that adding a small amount of Si particulate can slightly improve the physical properties of the composite solder compared to monolithic solder alloy. Microstructural analysis revealed the reinforcement seen well distributed between the grains boundaries with additions of 1.0 wt. % resulted with highest hardness value.
Effects of Annealing on the Properties of Copper Oxide Thin Films
Authors: Che Halin Dewi Suriyani , Talib Ibrahim Abu , Daud Abdul Razak , Hamid Muhammad Azmi Abd
Published: June 2015

Thin films of copper oxide were successively deposited on glass substrates by sol-gel like spin coating for 40 s and annealed in air at different temperatures (200-400°C). Precursor solutions were prepared by dissolving cupric chloride in methanol. Various stabilizers and additives were used to enhance the solubility of cupric chloride and to improve the adhesion between the films and the glass substrates. Glucopone was used as a surfactant to reduce the surface energy. The evolution of oxide coatings under thermal treatment was studied by glancing incidence X-ray diffraction and scanning electron microscopy. Annealing the films in air at 300°C converts the films to CuO. The general appearances of the films were uniform and brownish in color.
Modeling the Effect of ARC and other Parameters on the Efficiency of GaAs Solar Cell Using Silvaco
Authors: Sai Lim Kean , Osman Rozana Aina Maulat , Idris Mohd Sobri
Published: June 2015

Gallium Arsenide (GaAs) based solar cell which have nearly ideal direct bandgap of 1.43eV hold the highest single junction solar cell efficiency. GaAs solar cell without Anti-Reflective Coating (ARC) layer was studied and shows the efficiency ranges between 8% to 15%, followed by GaAs solar cell with efficiency ranges between 20% to 25% with ARC layer. The substrate thickness for both GaAs solar cell was varied from 0.1μm to 1.0μm. Increased of P-type substrate thickness shows a small variation in efficiency with parabolic shape, while increased of N-type substrate thicknesss increased the efficiency between 21% to 25% for single layer GaAs with ARC thickness. Besides that, increased of P-type doping concentration from 1×1018cm-3 to 1×1019cm-3 and fixed N-type doping will decreased the efficiency. However increased the N-type doping concentration from 1×1017cm-3 to 1×1018cm-3 and fixed the P-type doping will increased the efficiency. The thickness of ARC layer on GaAs solar cell was studied and shows that highest efficiency achieved at narrow thickness of ARC.
Sic-Reinforced Aluminum-Silicon Composite via Pressureless Infiltration Using Polystyrene as External Binder for Electronic Assemblies
Authors: Mohd Salim Nurul Nadia , Hussain Zuhailawati , Mohamad Hasmaliza , Anasyida Abu Seman
Published: June 2015

SiC-reinforced aluminum composite was developed by pressureless infiltration technique using polystyrene as external binder. The metal matrix composites obtained were characterized for phase composition, microstructure, density, porosity, hardness and thermal expansion. The SiC particles were uniformly distributed within the Al-Si matrix with the help of polystyrene as external binder. The variation in the density of the composites was found to be linear with volume percent of SiC. The hardness increased with increasing SiC content and highest hardness was 64.52 HV achieved with addition of 20 vol.% SiC. Thermal conductivity of the composites increased with increasing of SiC volume fraction up to 27.34 W/mK.
Compression Test and Energy Absorption of Polyurethane/Multi Walled Carbon Nanotubes Foam Composites
Authors: Sinar A.A. , Firuz Zainuddin , Nur Azni M.A. , Ahmad Zaidi Nur Hidayah , Hazizan Md Akil , Sahrim H.A.
Published: June 2015

This paper describes the effect of multi walled carbon nanotubes (MWCNTs) on the properties, especially the strength properties of rigid polyurethane (PU) foams produced from palm oil based polyol (POP) and methylene diphenyl diisocyanate (MDI). The foam composites in the ratio of 1:1.1 (wt. %) mixed at speed 2000 rpm. The addition of MWCNTs into PU foam are varies from 0 wt. % to 3 wt. %. The properties evaluated were compressive strength, density and energy absorption. Compressive strength of PU foam composites with 0.5% of MWCNTs showed the highest value 1.162 MPa of compressive strength compared to other foam composites. It was proved by modeling displacement nodal magnitude using NX Software (version 8.5). The density was increased 15.69 % with addition of 0.5 % MWCNTs into the PU foam. Increasing the amount of MWCNTs in PU foam was found to improve the energy absorption from 22.89 J for pure PU to 24.53 J for foam composites with 3 % MWCNTs.
Wear Properties of Metal Matrix Composite Al-Cu and Al-Cu-TiB2
Authors: Rosmamuhamadani Ramli , Sulaiman Shamsuddin , Ismail Mohd Idris Shah , Azmah Hanim Mohamed Arif , Talari Mahesh
Published: June 2015

Tensile and wear properties of aluminium (Al) based metal matrix composites (MMCs) was prepared by added titanium diboride (TiB2) with in-situ technique by salt route. The salts used in this research were potassium hexafluorotitanate (K2TiF6) and potassium tetrafluoroborate (KBF4). Nanocomposite samples were prepared by casting technique associated with incorporating 3 and 6 wt.% of TiB2 into matrix of Al-6wt.%Cu. Instron and wear tests machine were used to characterize the tensile and wear Al-Cu alloys properties. Results showed that increase in TiB2 content gave the high properties of tensile and wear behavior. The study indicates that TiB2 particles have giving improvement the wear performance of the Al–6wt.%Cu alloy. For a constant load and sliding speed, the wear rate decreases as a function of amount of TiB2 in the composite. The wear rate decrease with increasing in wt.% TiB2 particles for the all loads applied. However, addition of TiB2 particle to the Al–6 wt%.Cu matrix has show the coefficient value of wear decreases regardless of applied load. Study of the wear surfaces both alloy and composites by optical microscope suggests that the improvement in wear resistance is mainly due to the formation of finer groove or debris by content of TiB2.
Effect of Microwave and Conventional Heating on Sintering Behavior of Cu-10vol.%SiC Nanocomposites
Authors: Bashirom Nurulhuda , Kit Kwok Wai
Published: June 2015

Effect of heating mode and sintering temperature on sinterability of ex-situ Cu-10vol.%SiC composites was investigated. The Cu and SiC powder mixture were mechanically alloyed for 5 hours at 100 rpm in a planetary ball mill under argon atmosphere. The as-milled powders of Cu-10vol.%SiC were compacted and sintered in conventional tube furnace and microwave furnace at 700°C, 800°C, and 900°C. Microwave reduces the processing time significantly along with higher heating rates when compared to conventional tube furnace. Based on XRD result, the average Cu crystallite size is 80.49 nm after milling and its value remained under 100 nm after sintering. Microwave gave relatively smaller crystallite size than tube furnace. SEM revealed the homogeneous distribution of SiC particles in the Cu matrix in both heating mode. Relatively higher densification parameter was obtained by microwave furnace sintered at 900°C. This temperature was defined as an optimum sintering temperature and microwave sintering was claimed to exhibit much better sinterability than conventional tube furnace sintering.
Effects of Maleated Natural Rubber on Mechanical Properties of Polylactic Acid/Natural Rubber Blends
Authors: Mohammad N.N.B. , Arsad Agus , Rahmat Abdul Razak , Abdullah Sani N.S.
Published: June 2015

Brittle Polylactic acid (PLA) was toughened by introducing 5-20 wt. % of Natural Rubber (NR) through melt blending in a twin screw extruder. The results of tensile strength and Young’s modulus of PLA/NR blends were dramatically decreased. Maleic anhydride grafted natural rubber (NR-g-MA) was prepared and used to enhance the blends performance. The preparation of NR-g-MA was carried out using internal mixer by free radical melt grafting reaction followed by Fourier transform infrared spectroscopy (FTIR) to analyze the incorporation of MA on the NR. The compatibilization effect on the mechanical properties of PLA/NR blends was investigated with addition of 3 phr NR-g-MA. Comparison between PLA/NR/Compatibilizer and virgin PLA/NR blends significantly improved on the mechanical properties. FTIR result confirmed grafting reaction occurred between MA and NR.
Epoxy Layered Silicates with Fly Ash-Based Geopolymer: Flexural Properties
Authors: Mat Daud Yusrina , Kamarudin Hussin , Ruzaidi Che Mohd , Osman Azlin Fazlina , Al-Bakri Mustafa , Binhussain Mohammed
Published: June 2015

The effect of fly ash-based geopolymer in epoxy-layered silicates nanocomposites was studied through flexural properties and morphological characterization. In this study, a series of nanocomposites with fly ash-based geopolymer containing 1-7% wt were prepared. It was found that the addition of fly ash with lower content in the beginning showed lower flexural strength than nanocomposites without fly ash. However, flexural properties suddenly increased at 3% wt of fly ash geopolymer content in comparison to origin. This indicates the blending of fly ash geopolymer in nanocomposites systems have the ability for further studied.
Non-Isothermal Kinetic Modelling for Hydrogen Reduction of Ferric Oxide Using Matlab
Authors: binti Che Ibrahim Nurul Syazwina , Ramakrishan Sivakumar , Rezan Sheikh Abdul , binti Baharun Norlia , Alizadeh Reza , Roohi Parham
Published: June 2015

Reduction of iron oxide by hydrogen is important in the production of direct reduced iron. This method of iron production is gaining increasing significance as an alternative route to the blast furnace technology with the many difficult issues facing the latter, the most important being the problem related to environmental. In order to reduce the emission of greenhouse gases CO2, particularly for iron making, the production of Direct Reduced Iron (DRI) using hydrogen as the reducing gas instead of carbon monoxide is being considered. Reduction of pure hematite by hydrogen was studied at the laboratory scale, varying the experimental conditions like temperature (700oC and 800oC) and porosity (20% and 40%). Then, a Kinetic Modelling was conducted using Matlab software based on independently measured physical and thermodynamic properties of the reaction system and experimentally measured properties of the reactant solid (Fe2O3), gas phase (H2) and reactant product (Fe). There is a gap that occurs between the predicted result and the experimental result although the model explicated the trend and the behaviour of the reduction rate of Ferric Oxide and indicated a good homogeneity to the experimental conditions used in this research.
Microstructure and Compressive Strength of Magnesium-Zinc Alloy Reinforced with Different Percentage of Bio-Glass Content
Authors: Zaludin Mohd Amin Farhan , Jamaludin Shamsul Baharin
Published: June 2015

The objective of this work is to fabricate composite Mg-Zn filled with 45S5 bio-glass (5, 10, and 15 wt. %) via powder metallurgy. The microstructure of the sintered composite was investigated using optical microscope and scanning electron microscope. The densities of the composites were also evaluated. The densities of the compacts are increasing with increasing bio-glass content. Compression test was done by the Instron machine. The result showed that bio-glass was dispersed in the Mg-Zn matrix. Compressive strength was decreased as the amount of bio-glass increased. However, the results are still comparable to natural bone, which is important to reduce the stress shielding effect.
The Effect of Sintering Temperature on the Sintered Mg/3wt.%Zn-Bioglass (45S5) Composites
Authors: Llah Noorazimah Ab , Jamaludin Shamsul Baharin , Che Daud Zuraidawani
Published: June 2015

Magnesium and bioglass are a good combination to create biocompatible and bioactive materials. Magnesium-bioglass composites can be manufactured by casting or sintering. This work was aimed to manufacture the composite Mg-3wt.%Zn filled with 5, 10, 15, 20, 25 and 30wt.% bioglass (45S5) by powder metallurgy. Two sintering temperatures of 450 °C and 550 °C were used to sinter the samples. The sintered samples were characterized using optical micrograph and X-Ray diffraction (XRD). Optical micrograph shows that increasing of bioglass content lead to smaller grain size. XRD analysis shows no new crystalline compound detected on XRD pattern for Mg-3wt%Zn sintered at 450 °C ad 550 °C.
Microstructural and Corrosion Behavior of Biodegradable Magnesium Alloys for Biomedical Implant
Authors: Tok H.Y. , Hamzah Esah , Bakhsheshi-Rad Hamid Reza
Published: June 2015

Magnesium and its alloys have great potential as biodegradable metallic implant materials with good mechanical properties. However, the poor corrosion rate and the production of hydrogen during degradation hindered its application. Binary alloy, Mg-3Ca and ternary alloy, Mg-3Ca-3Zn alloy were studied to investigate their bio-corrosion properties. Microstructure evolution and surfaces of corroded alloys were characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS). The bio-corrosion behavior of the Mg alloys was investigated using immersion and electrochemical tests in Kokubo solution. Microstructural analysis showed that binary Mg-3Ca alloy consisted of α-Mg and Mg2Ca phases and ternary Mg-3Ca-3Zn alloy consisted of α-Mg, Ca2Mg6Zn3 and Mg2Ca phases. These phases had significant effect on the corrosion resistant of the alloy. Electrochemical test showed an improvement in ternary alloys where the corrosion current density reduced from 0.497 mA/cm2 in Mg-3Ca to 0.312 mA/cm2 in Mg-3Ca-3Zn alloy. Ternary Mg-3Ca-3Zn showed significant lower corrosion rate (1.1 mg/cm2/day) compared to binary Mg-3Ca (5.8 mg/cm2/day) alloy after 14 days immersion test.
A Short Review on In Vitro Bioactivity Behavior of Magnesium Composites
Authors: Ab Llah Noorazimah , Jamaludin Shamsul Baharin , Che Daud Zuraidawani
Published: June 2015

Research and development on the biomaterials are increasing due to the demand for materials that can bond to the living bones and by any chance can avoid second surgery procedure. Good bonding between bones and biomaterials or artificial implant can avoid loosening that due to the friction and wear. Currently, magnesium alloys are being actively researched because of their ability to serve as structural support in short term and can be absorbed in the body after healing process is completed. The addition of bioactive components such as hydroxyapatite and bioglass into magnesium is made to improve the bioactivity behavior of magnesium alloys. This paper summarizes the past and current studies of magnesium alloys in regards of in vitro bioactivity behavior, biomineralization and apatite formation mechanism.
Reactions of Limestone on the Slaking Process under Different Conditions of Parameters
Authors: Mohd Darus D. , Aimi Noorliyana H. , Azmi R. , Kamarudin H.
Published: June 2015

The reaction of limestone in the slaking process has been studied under different conditions of parameters such as calcination times, soaking times and particle sizes. The reactivity of quicklime was determined by recording temperature rise and the rate of temperature rise during the slaking process. The obtained ‘milk of lime’ is characterized using instrumental measurements such as X-ray fluorescence (XRF) to identify the chemical composition that exists in the sample. In this paper, the quicklime used during slaking test indicates the differential of temperature pattern which influences by quicklime particle sizes, calcination temperatures and soaking times. Results indicate that the optimum and efficient distribution of heat transfer and thermal decomposition onto quicklime can be obtained by calcining at 1100 °C with 60 minutes of soaking time samples which produced a highly porous structure towards higher reactivity of quicklime.
Effects of Quarry Dust as Partial Sand Replacement on Compressive Strength and Crack Profile of Cement Composites
Authors: Madzura M. , Mohd Noor Mazlee , Jamaludin Shamsul Baharin
Published: June 2015

This research presents the findings of experimental works in terms of mechanical properties and crack profile of cement composites containing quarry dust at different percentages as a partial sand replacement. The compositions of quarry dust were varied from 10 to 20 wt. % and were mixed into five different ratios. It was found that 0.45 water cement ratio was suitable to mix all proportions and values of slump were observed have been increased with the increasing percentage of quarry dust in cement composites. The compressive strength tests were carried out and the results showed that the compressive strength decreased at each 2.5 percent interval of quarry dust at 7 and 28 days of curing. However, the strength developments of cement composites were increased corresponding to the ages of curing. The crack profiles of cement composites have been analyzed to investigate the strength developments of the cement composites. According to the results, the cracks in the specimens were in shearing pattern at 10 and 12.5 wt. % of quarry dust in cement composites. Meanwhile, as the contents of quarry dust at 15, 17.5 and 20 wt. %, the specimens failed in shearing and splitting patterns. According to the findings of compressive strength and crack profile, the contents of quarry dust as a partial sand replacement is 12.5 wt. % were more suitable to be utilized in cement composite
Characterization of Hematite Nanoparticles (Fe2O3) Produced by High Energy Milling for Dye Removal Catalyst
Authors: Roshaida Arbain , Baharun Norlia
Published: June 2015

Hematite nanoparticles with average particle size of 75.6 and 93.4 nm were produced by mechanical grinding technique using planetary ball mill. The ground hematite were characterized by X-ray diffraction analysis technique, specific surface area analysis (BET), transmission microscope (TEM) and scanning electron microscope (SEM). The effects of different properties of hematite particles used as a catalyst for decolorization of synthetic dye, Remazol Red 3B (RR3B) were investigated. The experimental results show that smaller particle size of 75.6 nm decolourized at the rate of 95.8% within 10 min reaction while larger particle size of 93.4 nm decolorized at the rate of 95.9% within 60 min reaction. The decolorization of RR3B dye by both catalyst were achieved with minimum iron leached (<5 mgL-1) which fulfill the Malaysian Environmental Quality (Industrial Effluent) Regulations 2009. The continuous mode for decolorization of RR3B was carried out and complete decolorization was achieved with low iron dissolution which demonstrates the possibilities of using milled hematite as catalyst for large-scale textile industry wastewater treatment applications.
Strength of Adhesive T-Joint in Granulator Fluidization Bed at Elevated Temperature
Authors: Izzawati Basirom , Afendi Mohd , Nurhashima S. , Nor A. , Abdullah A.R. , Daud R. , Abdul Majid M.S.
Published: June 2015

This paper presents the results of an experimental investigation on mechanical characterization of adhesive T-joint in granulator fluidization bed at elevated temperature. This research aims to explore the suitability of adhesive bonding between stainless steel plate and perforated plate to replace plug weld in granulator fluidization bed. For this purpose, T-joint and bulk specimens were prepared for tensile loading tests, at different temperature. Measurement of the temperature-dependent of the tensile strength was conducted using thermostatic chamber attached to a universal testing machine for a range from room temperature to 100°C. The strength of adhesive T-joint decreases for temperatures over than 35°C. This is because at high temperature, the failure is determined by the changes of mechanical properties of adhesive. The results have shown that the strength of adhesive T-joint was affected by both temperature and bondline thickness. The objective of the present study was to examine a series of adhesively-bonded T-joints in tension at elevated temperatures between room temperature and 100°C having various bond thicknesses.
A Study on the Impact of the Milling Parameters on the Surface Roughness when Using Polyurethane Board as a Base Material in Manufacturing Automotive Checking Fixtures
Authors: Catherine Louis Denis Kevin , Raja Ma’arof Raja Aziz , Suresh Sangeeth
Published: June 2015

The improvement of the quality of the surface roughness of the polyurethane board (PB) has always been a challenge in the automotive industry. A suitable combination of the milling parameters is very important in order to get a high grade of smoothness specially when dealing with complex designs such as curved profiles. In this paper, a half factorial design of experiment (DoE) with 16 runs at two levels is applied in the milling operation of the checking fixtures of a car seat belt bracket under a dry cutting condition. The Feed rate, Depth of cut, Spindle speed, Step over and Plunge rate were taken as the variables for the DoE. Two different milling tools, a flat end mill of diameter10 mm for roughing, and a ball nose of diameter 5 mm for the finishing process were used. Minitab software was use to analyze the correlation between the parameters and the surface roughness. The most influential factor in the milling process was observed to be the Step over.
Joining Dissimilar Metals between Steel and Aluminum by TIG Welding
Authors: Jamaludin Shamsul Baharin , Abd Latif Mohd Zahir , Mohd Noor Mazlee , Hussin Kamarudin
Published: June 2015

The effect of welding current on the joining of mild steel and aluminum 6063 has been investigated. The joining was carried using a tungsten inert gas (TIG) welding. The welding currents used were 30 A to 80 A. The formation of intermetallic reaction layers (IML) and tensile shear strength of the joining were investigated. The result showed that tensile shear strength increased as welding current increased up to 55 A. Microstructural analysis showed that intermetallic reaction layer was formed at the interface between steel and aluminum alloy during welding process. The thickness of IML was decreased with decreasing welding current.
Corrosion Behavior of WC-Co Cermet Coatings
Authors: Kamdi Zakiah , Phang C.Y. , Ahmad H.
Published: June 2015

Metal-ceramic composite or cermet coatings have become popular due to their enhanced wear and corrosion resistance properties. Cermet consists of ceramic particulate embedded in a metallic binder. WC-Co coatings are often used in applications that require wear resistance, but there are many applications in which thermally sprayed coatings have been deposited on components that operate under both abrasive and corrosive condition. Thus, in this study, the corrosion behavior of WC-12wt%Co in different electrolyte has been evaluated. Electrochemical test has been done in three electrolytes namely 0.5 M hydrochloric acid, HCl, 0.5 M sulfuric acid, H2SO4 and 0.5 M sodium hydroxide, NaOH. It is found that corrosion potential of this coating in acidic environment is more positive compares to in alkaline environment. Both in acid and alkaline electrolyte, binder dissolution were preferential. It may be concluded that this coating have higher corrosion resistance in alkaline electrolyte than in acid electrolyte.
Restauration du site minier Lorraine, Latulipe, Québec : Résultats de 10 ans de suivi
Authors: Bussière Bruno , Potvin Robin , Dagenais Anne-Marie , Aubertin Michel , Maqsoud Abdelkabir , Cyr Johanne
Published: June 2015

Le gisement polymétallique de la mine Lorraine (Latulipe, Québec), exploité de 1964 à 1968, a généré environ 600 000 tonnes de résidus miniers potentiellement générateurs d’acide. Ces résidus ont été entreposés dans un parc d’une superficie de 15,5 hectares. Le parc a été laisse à l’abandon pendant environ 30 ans. Durant cette période, les réactions d’oxydation des sulfures contenus dans les rejets miniers se sont enclenchées, ce qui a conduit à la génération de drainage minier acide (DMA), dont les traces sont principalement observées dans le secteur sud du parc. Afin de réduire les impacts sur l’environnement, des travaux de restauration ont été entrepris a l’été 1998. L’approche de restauration préconisée inclut la construction d’une couverture avec effets de barrière capillaire (CEBC) pour limiter la migration de l’oxygène jusqu’aux résidus réactifs. En plus de la CEBC, un système de traitement passif, constitue de drain dolomitique (3) et calcique (1), a été mis en place pour améliorer la qualité de l’eau des exfiltrations du site. Les mesures effectuées sur le site montrent qu’après une période transitoire de deux ans, la CEBC est efficace pour limiter la migration de l’oxygène. Les flux mesures sont inferieurs à l’objectif de design, qui était de l’ordre de 20 à 40 g d’O2/m2/an. Malgré la bonne performance de la CEBC, l’eau qui sort du site (avant traitement passif) ne respecte toujours pas les critères de rejets québécois ; cependant, une amélioration notable a été observée au cours des deux dernières années. Grâce aux drains dolomitiques, on améliore significativement la qualité de l’eau de l’effluent final, sans toutefois respecter tous les critères.
Valorisation de déchets de caoutchouc dans les matériaux de construction : cas d’un composite cimentaire cellulaire
Authors: Benazzouk A. , Douzane O. , Queneudec M.
Published: June 2015

In this work, the idea is to use rubber waste particles as a raw material, to develop a new lightweight construction materials. The objective of the research reported in this paper is to investigate the physico-mechanical properties of Aerated Cement-Rubber Composites (ACRC), based on rubber particles. The volume content ratio of the rubber particles ranged from 0% to 50%. The aerated composite was produced using a new type of proteinic air-entraining agent, in accordance with a specific aerating process derived in the laboratory. The aerated composite was produced to be used in cellular concrete applications. Results from tests performed on fresh aerated composites have demonstrated many attractive properties, such as improved workability and a high stability of air bubbles within the matrix. A study conducted on hardened composite properties has indicated a significant reduction in sample unit weight, thereby resulting in a level of compressive strength. The composite satisfies the basic requirement of construction materials, and could be used for insulated load-bearing wall this study has also highlighted the effect of the proteinic air-entraining agent on the cementrubber interaction system, as regards the composite’s compressive strength. However, an examination of the composite’s water capillary absorption reveals that the addition of rubber particles tends to restrict water propagation and reduce water absorption; sorptivity values decrease with increasing rubber particles content.

Cette étude concerne l’évaluation des propriétés du composite cellulaire ciment-caoutchouc, élaboré à base de poussières de caoutchouc pour des teneurs allant de 0 à 50 %. L’allégement a été effectué suivant un procédé d’allégement par moussage protéinique, mis au point au laboratoire, en vue de l’utilisation du composite dans le domaine d’application des bétons cellulaires. L’étude du composite à l’état frais a montré une amélioration de la maniabilité, avec une bonne stabilité des bulles d’air dans la matrice. L’étude du composite à l’état durci a montré une nette réduction de la masse volumique, avec des propriétés mécaniques compatibles avec l’utilisation en isolant porteur. L’effet de l’agent entraîneur d’air protéinique sur les liaisons matrice/caoutchouc dans la résistance du composite a été mis en évidence. L’étude de l’absorption par capillarité du composite a montré que l’ajout de poussières de caoutchouc réduit la sensibilité à l’eau du composite.