bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of Inner Steel Tube Cross-Sectional Shape on Compressive Behavior of Square FRP-Concrete-Steel Double-Skin Tubular Columns
Authors: Louk Fanggi Butje Alfonsius , Ozbakkloglu Togay
Published: April 2015

Recently, a new type of composite system was proposed in the form of fibre reinforced polymer (FRP)-concrete-steel double-skin tubular columns (DSTCs). The performance of this column system, which consists of an outer tube made of FRP and an inner tube made of steel, has been experimentally investigated in a number of studies. However, apart from a single study reported on square DSTCs, all of the existing studies have been concerned with DSTCs with circular external tubes. This paper reports on part of an ongoing experimental program at the University of Adelaide that was aimed at addressing this research gap. The effect of cross-sectional shape of inner steel tube on compressive behaviour of square DSTCs was investigated through the test of 16 hollow and concrete-filled DSTCs. The result of the experimental study indicate that concrete in hollow DSTCs with circular inner steel tubes develop significantly larger ultimate axial stresses and strains than concrete in companion hollow DSTCs with square inner steel tubes. On the other hand, the results also indicate that the presence of a concrete-filling inside inner steel tubes results in a significant improvement in the behavior of DSTCs with square inner steel tubes.
Crack Behaviour of Retrofitted Pre-Tensioned Concrete Beam
Authors: Suliman Nurul Huda , Bakar A. Abu , Hamzah Siti Hawa , Shahar Norzahiah
Published: April 2015

Crack is a common cause of the degradation of concrete and may affect its structural durability. In order to ensure the bridge is safe utilized in anticipated period of their future service, a proper maintenance process and procedure should be taken. Therefore in this study, static load test were performed on a pre-tensioned (PRT) concrete beam to investigate crack behaviour before and after retrofitting process as well as to determine the effectiveness of the retrofitting method. A control beam named PRTB1 will fully loaded until fail to determine its maximum load capacity and critical load of the beam. Hence another beam named PRTB-FRP will be loaded until it reached it critical load capacity before retrofitted using Fiber Reinforced Polymer (FRP) plates located beneath the centre of the beam. After the retrofitting process PRTB-FRP will be put again under the static load. The load capacity of PRTB-FRP increased compared to PRTB1 with some improvement in crack propagation behaviour after retrofitted.
Finite Element Modelling of Reinforced Concrete Slab at Elevated Temperature Using ABAQUS
Authors: Ab-Kadir Mariyana Aida , Awal A.S.M. Abdul
Published: April 2015

This paper investigates the finite element modelling of the temperature distributions of reinforced concrete slab using a general purpose non-linear finite-element program, ABAQUS. The reinforced concrete slab is tested under exposure to designed fire in order to validate the shell element in in the ABAQUS program. The modelling results showed agreement with the fire test and it demonstrated that the ABAQUS shell element can be used to predict fire behaviour within reinforced concrete slab in elevated temperature conditions.
An Analytical Study on the Performance of Wind Resistant System Considering Climate Change
Authors: Kim Dong Keon , Son Hong Min , Hu Jong Wan
Published: April 2015

As the development of structural system and material enable to construct many high-rise buildings. However, high rise buildings are vulnerable to the strong wind rather than seismic excitation, because they have relatively long period. Recently, intensity and frequency of extreme wind such as hurricane and typhoon have been increased with the weather change all over the world. Therefore, in this study, 50-story building with three types of braces which are diagonal brace, X-brace, Chevron brace are modelled and compared with non-braced 50-story building by changing wind speed. Finally, all the results from four cases are compared for wind performances. As a result, buildings reinforced with X-brace and Chevron braces have a good performance subjected to the strong wind.
Effect of Sea Water Submersion on GFRP-S Bonding Capacity of Reinforced Concrete Beam
Authors: Irmawaty Rita , Djamaluddin Rudy , Kwandou Robby
Published: April 2015

An experimental investigation on laboratory simulation of reinforced concrete beams submerged in sea water was carried out. The research aimed to analyze the beam flexural behavior cause by submersion effect in the marine environment and simulation pool. Flexural testing was conducted by using two point loading up to beams ruptured. Total 18 reinforced concrete beams of 10 cm x 12 cm x 60 cm in dimension with GFRP-S bonded on the bottom side. Nine beams were submerged in the marine environment and 9 beams were submerged in the simulation pool. Exposure period is 1, 3 and 6 months after 28 days cured in fresh water. The result indicate that the ultimate load and bonding capacity of beam specimens submersed in the marine environment were relatively lower than the specimens submersed in simulation pool. Based on this experimental study, submerging of specimens in simulation pool (Pp
) could be used to predict specimens submersed in marine (Ps) by using equation
Experimental Investigation of Concrete Confinement with Textile Reinforced Concrete
Authors: Yin Hong Yu , Xun Yong , Ji Chen Bin , Sun Shuai
Published: April 2015

Mechanical property and constraint mechanism of concrete cylinders confined by TRC under uniaxial compression is analyzed. 24 concrete cylinders confined by TRC and 8 unconfined concrete cylinders are loaded under uniaxial compression to investigate the performance based on textile ratio, section dimension and strength of concrete. Based on the test results, stress process and failure mechanism of strengthened members is studied, stress-strain relationship of strengthened members is researched, effect of ratio of textile reinforcement, section dimension and concrete strength on ultimate strength of strengthened members is also evaluated. The results show strengthened members showed increasing in strength and deformation. Strengthened members showed drum-shaped shear damage. With the increasing of textile ratio, the confining effect of TRC on the concrete increases. With the increasing of section dimension, the confining effect of TRC on the concrete decreases. The confining effect of TRC on low strength concrete is stronger.
Finite Element Analysis of Automobile Suspension Control Arm
Authors: Zhang Hai Bo , Zhang Rui Jun , Chang Ying
Published: April 2015

In order to improve the reliability and stability of the automobile suspension system, the important parts of automobile suspension control arm is studied. Reverse engineering technology is applied to reverse modeling according to the characteristics of complicated suspension control arm shape. At the same time, the automobile suspension control arm is analyzed under load condition to ensure that the automobile suspension control arm is safe in the process of driving. The control arm meshing and strength analysis are completed by ANSYS analysis software. Finally, ANSYS fatigue analysis module is used to verify that the automobile suspension control arm can meet the requirement of fatigue strength.
Synthesis and Performances of Crosslinking Polymeric Dyes
Authors: Tang Bing Tao , Wang Wen Tao , Qiu Jin Jing , Huang Jian , Zhang Shu Fen
Published: April 2015

Development of dyes with high fixation and salt-free dyeing process for cotton and silk is essential for the textile industry due to ecological and economical reasons. In this study, the synthesis of novel crosslinking polymeric dyes and its salt-free crosslinking dyeing method are described, and cotton and silk have been effectively dyed with the novel dyes. Excellent dye fixation of over 99% on silk and over 97% on cotton, were achieved in a padding process in the salt-free condition. The dyes showed excellent wet fastness values equal to those observed for the standard reactive dyeing.
Numerical Analysis of Swirl Chamber Combustion System in DI Diesel Engines with the Conical-Spray
Authors: Wei Sheng Li , Ji Kun Peng , Leng Xian Yin , Liu Xuan
Published: April 2015

In order to promote the quality of mixture and improve the fuel spray spatial distribution, enhancing airflow movement in a combustion chamber, a new swirl chamber combustion system in DI (direct injection) diesel engines is proposed based on conical-spray. Numerical simulations have been conducted by using the FIRE v2008 code. Several different widths of passage and spray angles are investigated in a single cylinder 135 diesel engine. The combustion and emissions performance were investigated by different conical-spray nozzles and combustion chambers with a constant compression ratio. The results show that using this combustion system, the mixture formation and combustion processes have been improved by a certain longitudinal swirl when the air is squished into the swirl chamber through the relative narrow passage. Moreover, the formation of homogeneous mixture is accelerated and the combustion is improved compared with that of conventional combustion system. The cases show the passage width of 5mm and conical spray cone angle of 140° has a better performance in the new combustion system.
Structural Modification Strategies to Improve Piezoelectric Energy Harvester Performance
Authors: Salleh Hanim , Lam Mun Heng , Muhamad Linasuriani , bin Jaafar Mohd Firdaus
Published: April 2015

Harvesting energy from vibrations has received massive attention due to it being a renewable energy source that has a wide range of applications. Over the years of development, there is always research to further improve and optimise piezoelectric energy harvesters. This paper presents work on improving piezoelectric energy harvesters based on the structural modifications. Four different strategies of structural modification are employed for optimization by using additional beam structure as well as incorporation of rubber layer. This work summarized the optimum performance of the strategies at a resonance frequency of 60 + 2 Hz at 0.25g. The parameters compared among the strategies are voltage, power, PZT power density, spatial power density and specific power density. The results are also compared with other similar work. In general, structure with an addition of silicon rubber beam was found to give the best power density output and produce 253% increase of power ouput as compared to basic PZT energy harvester.
Verification of External Gas-Assisted Mold Temperature Control for Injection Molding Process
Authors: Minh Pham Son , Trung Do Thanh
Published: April 2015

In this study, a hot gas is used for heating the cavity surface of a mold. Different stamp thickness were designed and insert into the cavity plate. The stamp surface temperature was heated to above the glass transition temperature of the common plastic material. The heating result show that cavity surface can be heated to 196 °C after 20 s. The highest temperature appears at the center stamp surface. The stamp thickness strongly affects the heating speed and heating uniformity. When the stamp thickness is 0.5 mm the fastest heating rate can be reached with the value of 8.3 oC/s. With the thicker stamp, the slower heating rate could be reached.
Solubility Determination of Tamarind Seeds Extracts by Using Supercritical CO2 Extraction
Authors: binti Idris Sitinoor Adeib , Jantan Sawai Anak , Alias Nur Hashimah , binti Mohd Yusof Noorsuhana , Ghazali Nurul Aimi , Yahya Effah
Published: April 2015

In recent years, tamarind seeds extracts are used widely in food, pharmaceutical and textile industry due to unique functions as cooking oil, antibacterial and thickening agent. In this study, a simple static technique is used to obtain the solubility of tamarind seed in supercritical carbon dioxide because there is no study on that yet. The solubility measured is performed at temperatures and pressures ranging from 40oC, 60oC, 80oC and 3000psi, 5000psi and 7000psi respectively; resulting in mass fractions in the 6.00 x 10-8 to 5.84 x 10-7 range. The Chrastil model is used to correlate the experimental data. The oil yield extract in range of 0.0375 to 0.365g.
Effect of Temperature of Distilled Water on the Morphology of Nanoporous Zinc Oxide Synthesized by Anodizing
Authors: Voon Chun Hong , Lim Bee Ying , Hashim Uda , Md Arshad Mohd Khairuddin , Ting Sam Sung , Foo Kai Loong , Ten Seng Teik
Published: April 2015

In this work, the effect of temperature of distilled water on the morphology of ZnO nanoporous thin films formed by anodizing was studied. ZnO nanoporous thin films were formed by anodizing of Zn plates at voltage 30 V in 500 ml distilled water of temperature ranged from 5 °C to 25°C. As anodized zinc plates were characterized by using SEM and XRD. Characterization of as anodized Zn plates using SEM showed that the morphologies of the as anodized Zn plates were significantly influenced by the temperature of distilled water. Nanoporous ZnO thin films were formed when 15 °C to 25 °C were used while ZnO thin films without nanoporous structures were formed when 5°C and 10 °C were used. XRD analysis indicated the ZnO thin films formed in distilled water of 5 °C to 25°C were of hexagonal wurtzite structures.
Characterization of Cuprous Oxide Thin Films Prepared by Sol-Gel Spin Coating Technique with Different Additives
Authors: Halin Dewi Suriyani Che , Ahmad Khairel Rafezi , Kamarudin Hussin , Talib I.A. , Daud Abdul Razak , Hamid M.A.A. , Sandu Andrei Victor
Published: April 2015

Cuprous oxide (Cu2O) thin films were formed onto indium tin oxide (ITO) coated glass substrate by sol-gel spin coating technique using different additives namely polyethylene glycol and ethylene glycol. It was found that the organic additives added had an important influenced on the formation mechanism of Cu2O films and lead to different microstructures and optical properties. The films were characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM) and ultraviolet-visible spectroscopy (UV-Vis). Based on the FESEM micrographs the grain size of film prepared by polyethylene glycol has smallest grain of about 83 nm with irregular shape. The highest optical absorbance film was obtained by the addition of polyethylene glycol.
Nanoemulsion Applications in Enhanced Oil Recovery and Wellbore Cleaning: An Overview
Authors: Hashimah Alias Nur , Aimi Ghazali Nurul , Amran Tengku Mohd Tengku , Adieb Idris Sitinoor , Yahya Effah , binti Mohd Yusof Noorsuhana
Published: April 2015

This article is an overview of potential applications of nanoemulsion as a promising candidates for enhanced oil recovery (EOR) and as a medium for wellbore cleaning. Nanoemulsion is an emulsion that has nanosize particle distributions in the range of below 500 nm. It also has lower interfacial tension (IFT) as low as the value of 0.001 mN/m. The small particle size distributions in nanoemulsion resulted the good properties of nanoemulsion in term of large surface area. This excellent property will improve the sweeping efficiency of the oil droplet in the reservoir and finally increase the oil recovery. Besides that, the unique features possess by nanoemulsion make it suitable as superior wellbore cleaner as compared to conventional detergent-based cleaner. Thus, the significance of nanoemulsion becomes the major highlight in oil and gas industry. This overview on nanoemulsion applications is imperative and necessary in order to provide an insight for the future development and perhaps open a door to extend the applications of nanoemulsion to other more challenging areas.
Structural Analysis of LiNi0.7Mn0.3O2 as Cathode Material for Rechargeable Lithium-Ion Batteries
Authors: Chin Y.M. , Osman Rozana Aina Maulat , Idris Mohd Sobri
Published: April 2015

The layered rock salt LiNi0.7Mn0.3O2 was prepared by conventional solid-state synthesis route. The prepared samples were analysed using X-ray diffraction (XRD) to determine purity of samples. Then, structural analysis and crystallographic properties of samples were analysed using Rietveld refinement. Rietveld refinement results indicated that the amount of cation disorder in the layered rock salt structure highly influenced by temperature and synthesis conditions. The most optimum temperature to obtain the highest degree of cation ordering is between 850oC and 900oC in air.
Carbon Coated TiO2 and it Application on Photodegradation of 4-Chlorophenol under Solar Irradiation
Authors: Nawawi Wan Izhan , Mahrouqi H.K.N. , Nawi M.A. , Ishak Mohd Azlan Mohd , Jawad Ali H. , Ismail Khudzir
Published: April 2015

The photocatalytic degradation of 4-Chlorophenol (4CP) using carbon C coated TiO2 (C-TiO2) and pristine TiO2 under solar irradiation was carried out in a suspension mode under custom made glass cell reactor with continuous aeration supply. It was found that 0.3 and 0.6 g were the optimum loading for C-TiO2 and pristine TiO2 respectively in the degradation of 20 mg L-1 4CP under solar irradiation. The optimum C-TiO2 was found six times faster than pristine TiO2 based on pseudo first order rate constant of 4CP photodegradation. No adsorption was observed in the photocatalysts. The intermediates observed during this photocatalytic degradation process were maleic acid, hydroquinone (HQ), benzoquinone (BQ), 4-chlorochetol (4CC) and resorcinol.
The Influences of Cure Characteristics and Physical Properties of Recycled Nitrile Glove Filled Epoxidized Natural Rubber Compounds (NBRr/ENR25)
Authors: Afiratul A.A. , Noriman N.Z. , Sam S.T. , Hanafi Ismail , OMAR MOHD FIRDAUS
Published: April 2015

The effects on curing characteristics and physical propertiesof recycled nitrile glove (NBRr) filled epoxidized natural rubbers (ENR25) were examined. Two different size ranges of NBRr particles, i.e., S1 (250μm-500μm) and S2 (2cm-5cm) were used in this study. The NBRr/ENR25 compounds with five different compositions of NBRr (5, 15, 25, 35 and 50 phr) were prepared using a two roll-mill at room temperature. The result of cure characterization show that scorch time, t2 and cure time t90 of the NBRr/ENR25decreased with the increased of NBRr content due to the existence of crosslinked precursors and unreacted curativein the recycled rubber.NBRr/ENR25 compounds with fine size, S1 of NBRr particles exhibit lower minimum torque (ML) compared with the coarse size, S2 which resulted in more efficient processing. The maximum torque (MH) of all NBRr/ENR25 compounds show the increasing trend with increased NBRr content probably due to the good interactions in NBRr/ENR25 compounds. For physical properties, NBRr/ENR25 compounds with fine size, S1 of NBRr particles exhibited the higher hardness and crosslinking density at all compound ratios. The results overall indicated that the NBRr/ENR25 with fine size, S1 of NBRr particles show better cure characteristics and physical properties (crosslink density and hardness test) compared to coarse size, S2 of NBRr particles.
Conductivity and Structural Studies of PEMA/ENR-50 Blend with LiCF3SO3 Salt
Authors: Sukri Nursyazwani , Mohamed Nor Sabirin , Subban R.H.Y.
Published: April 2015

Solid polymer electrolytes (SPEs) comprising of a blend of Poly (ethyl methacrylate) (PEMA) and Epoxidized natural rubber-50 (ENR50) as polymer host and lithium triflate (LiCF3SO3) as dopant were prepared by solution cast technique. The blend based polymer electrolytes have a fixed PEMA/ENR50 ratio of 70:30 by wt. % as at this ratio ENR-50 imparted stable mechanical properties to the otherwise fragile PEMA. The incorporation of LiCF3SO3 into the blend is found to increase the conductivity of PEMA/ENR50. The highest conductivity achieved was 3.64 x 10-5 Scm-1 at 40wt. % LiCF3SO3. The structure of the samples was investigated by X-ray diffraction and the results show that the highest conducting sample is the most amorphous.
In Vitro Mechanical Properties of Metallocene Linear Low Density Polyethylene (mLLDPE) Nanocomposites Incorporating Montmorillonite (MMT)
Authors: Osman Azlin Fazlina , Alakrach Abdulkader M. , Kalo Hussein , Dahham Omar Sabbar , Al Bakri A.M. Mustafa
Published: April 2015

The viability of metallocene linear low density polyethylene (mLLDPE) nanocomposites is being investigated as a new material for biomedical application. The effect of filler loadings on the ambient and in vitro (after being exposed in oxidizing condition, 37°C) mechanical properties was studied. We observed that, the mLLDPE nanocomposites have higher mechanical property values as compared to the neat mLLDPE. Furthermore, these properties were less affected by the in vitro conditions. The best ambient and in vitro mechanical properties were achived when 3wt% of organically modified MMT (organo-MMT) was added into the mLLDPE. It was postulated that the presence of MMT layered structure introduced a more tortous path for the diffusing of oxidant molecules, thereby decreasing their permeability towards mLLDPE molecular chains. The smaller amount of oxidants entering the molecular chains resulted in greater retention of mechanical properties when tested in vitro. This preliminary biostability studies show promising properties of the mLLDPE nanocomposite which possess the potential to be further developed for biomedical devices.
Study Regarding the Influence of Polymerization Mode of Light Unit on Surface Microhardness of Composite Resins
Authors: Stoleriu Simona , Iovan Gianina , Perju Manuela Cristina , Sandu Andrei Victor , Andrian Sorin
Published: April 2015

The aim of the study was to compare the surface microhardness of composite resins polymerized in different mode of light unit. Three commercial composite resins: Charisma (Heraeus Kulzer Co.), Filtek Z 250 (3M ESPE Co.) and G-aenial Anterior (GC Company Co.), were used in this study. Fifteen samples of each material were obtained by placing the composite resin in plastic rings having 2 mm high and 6 mm inner diameter. All composite samples were cured using blue light-emitted diode G 0010 (SKI, China). Five samples were cured using ramp mode of the light unit, five samples were cured using single light: high intensity (constant) mode and five samples were cured using pulse mode. The samples were finished and polished and then stored in distilled water, at room temperature for 48 hours. The samples were subjected to microhardness evaluation using microhardness tester (Micro-Vickers Hardness System CV-400DMTM, CV Instruments Namicon). A 50 g load was applied through a Vickers indenter. For each sample three indentations were made in different areas of the sample and the value of Vickers hardness was calculated as a mean result of the three recordings. Statistical Mann-Whitney U test and Kruskal-Wallis test were used to compare the values of surface hardness. Polymerization of all three composite resins using pulse mode leaded to significantly lowest mean hardness values and single light high intensity mode to the highest values. Filtek Z250 composite resin showed the highest microhardness mean values in all three polymerization mode and Charisma the lowest values. Surface microhardness of composite resins is influenced by different modes of light unit. Single light high intensity mode of polymerization leaded to the highest values of microhardness, followed in descending order by ramp and pulse mode. The best results regarding the surface microhardness was recorded for Filtek Z250composite resin, followed in descending order by G-aenial Anterior and Charisma.
The Effects of Different Fillers on Mechanical and Morphological Properties of SBR/CRr Blends
Authors: Azmi Ahmad Azrem , Zulkepli Nik Noriman , OMAR MOHD FIRDAUS , Kamarudin Hussin
Published: April 2015

This research deals with the effects of different fillers of styrene butadiene rubber/recycled chloroprene rubber/carbon black (SBR/CRr/CB) blends and styrene butadiene rubber/recycled chloroprene rubber/calcium carbonate (SBR/CRr/CaCO3) blends on mechanical and morphological properties. The range size of CRr used in this study was 181 – 549 μm. Both SBR/CRr/CB blends and SBR/CRr/CaCO3 were prepared using a two roll mill at room temperature with blend ratios 95/5, 85/15, 75/25, 65/35 and 50/50. It can be observed that, tensile strength, Eb and rebound resilience of SBR/CRr/CB blends and SBR/CRr/CaCO3 blends decreased with increasing CRr content in both blends. However, M100 increased with increasing CRr content in both blends. The scanning electron microscopy (SEM) of the tensile fractured surface of SBR/CRr/CB blends illustrates better adhesion between CB and SBR matrix compared to SBR/CRr/CaCO3 blends at all blend ratios.Keywords: styrene butadiene rubber, recycled chloroprene rubber, mechanical properties, SEM
The Performance of Double Sheathed Composite Walling Made from Profiled Steel Sheeting and Dry Board
Authors: Majid Masni A. , Wan Badaruzzaman Wan Hamidon
Published: April 2015

This paper presents the performance of an emerging prefabricated composite system made from profiled steel sheeting and dry board. Six full-scale wall specimens were prepared and tested under axial load. The results of the experimental investigation showed that the performance of the composite walls is governed by the strength of profiled steel sheeting while the dry board performed as a wall sheathed. A partial interaction between the profiled steel sheeting and dry board was achieved by using self-drilling screws. The maximum axial load capacity is 1329kN for the double sheathed wall. The failure behavior of single and double sheathed composite wall exhibited similar pattern such as global buckling and cracking. The developed composite wall system was found the great potential in prefabricated and modular construction in Malaysia.
Rheological and Thermal Study of Chitosan Filled Thermoplastic Elastomer Composites
Authors: Lim B.Y. , Poh C.S. , Voon Chun Hong , Salmah Husseinsyah
Published: April 2015

The chitosan filled thermoplastic elastomer (TPE) composites with different filler loading was prepared by melt mixing at 180 °C. The effect of 3-aminopropyltriethoxysilane (3-APE) as coupling agent on the rheological and thermal properties of composites were investigated. The melt flow indexer was used to characterize the melt flow index (MFI) of TPE/Chitosan composites at temperature of 180 to 210 °C. It was found that addition of chitosan into composites had reduced the MFI values. Besides that, the MFI values of composites were found to increase linearly with temperature. The treated composites demonstrated lower MFI values, indicated that better interfacial bonding was established between chitosan and TPE and the flowability of the composite melts was hindered. The TGA results reported that the treated composites had better thermal stability and lower total weight loss as compared to untreated composites at similar filler loading.
Blended Cement Containing High Volume Ground Dune Sand and Ground Granulated Blast Furnace Slag for Autoclave Concrete Industry
Authors: Alawad Omer Abdalla , Alhoziamy Abdulrahman , Jaafar Mohd Saleh , Abdul Aziz Farah Noor , Al-Negheimish Abdulaziz
Published: April 2015

This paper presents the results of using ground dune sand (GDS) and ground granulated blast furnace slag (slag) as high volume cement replacement materials. In this study, plain and four blended mixtures were fabricated and cured under normal and autoclave conditions. For the blended mixtures, 40% GDS by weight of the total binder materials and different percentages of slag (15%, 30% and 45%) were incorporated as partial cement replacement materials. The effect of curing conditions (normal and autoclave) on the compressive strength of prepared mixtures was studied. The results showed that, for the autoclave cured mixture, up to 85% of cement can be replaced by GDS and slag without significant drop in the compressive strength. Microstructure analyses using scanning electron microscope (SEM) and X-ray diffraction analysis (XRD) were carried out to examine the microscale changes of the hydrated mixtures. The SEM revealed the formation of thin plate-like calcium silicate hydrate and compacted microstructure of autoclave cured mixture. XRD showed the elimination of calcium hydroxide and existence of residual crystalline silica of all blended mixtures.
Effect of Alkaline Activator Ratio to Mechanical Properties of Geopolymer Concrete with Trass as Filler
Authors: Risdanareni Puput , Ekaputri Januarti Jaya , Al Bakri Abdullah Mohd Mustafa
Published: April 2015

This paper describes the effect of alkaline activator ratio (Na2SiO3/NaOH) to mechanical properties of geopolymer concrete. The mechanical properties of geopolymer concrete were assessed by setting time, split tensile strength and porosity. Fly ash was used as a cement substitute, and trass used as filler. While, Natrium hydroxide (NaOH) and Sodium Silicate (Na2SiO3) was applied as alkaline activator. In this study, NaOH concentration eight and ten molar with an alkaline activator ratio Na2SiO3/ NaOH by mass: 0.5, 1, 1.5, 2 and 2.5 were used. The test result showed that setting time, porosity and split tensile strength of geopolymer concrete were hardly influenced by NaOH concentration and the alkaline activator ratio. The alkaline activator ratio of Na2SiO3/NaOH has an optimum value at 2 and 2.5. Test result showed that the fastest setting time was 25 minute, the highest amount of closed porosity was 9.035 % and the highest split tensile strength was 2.86 MPa.
Simulation Behavior of Flexure in Reinforced Concrete Beams Strengthened with Carbon Fiber Reinforced Polymer (CFRP)
Authors: Alfahdawi Ibrahim H. , Osman S.A.
Published: April 2015

When reinforced concrete (RC) beams are found deficient in flexure, and fails in shear capacity after shear strengthening, the need to use new technique for flexure strengthening become important. Over the years, there are many experimental studies had been carried out with this technique of strengthening, and finding from other researchers have proved to be effective and successful. In this study, the behavior of flexure in RC beams strengthened with carbon fiber reinforced polymer (CFRP) were investigated. ANSYS11 software package of finite element method was use to simulate two models of RC beams with different parametric study such as (i) effect of grade of concrete, (ii) number of layers of CFRP strips, (iii) effect of steel stirrups and CFRP strips and (iv) longitudinal reinforcement yield stress. The results show that for beams strengthened with CFRP has increased in capacity load up to 32.8%. In general, good agreement between the FE solution and the available experimental results has been obtained.
Instantaneous Deflection of Steel Fibre Reinforced Selfcompacting Concrete Beams
Authors: Anand Vijay , Maganti Janardhana , Ibrahim Azmi , Muthu K.U.
Published: April 2015

Self-compacting concrete has been accepted as a quality product. A Suitable method for estimating the instantaneous deflection for SFRSCC is not available. In this study an effective moment of inertia function has been formulated with a power coefficient obtained from authors and others data. The proposed method is found to predict the instantaneous deflections satisfactorily.
The Characteristics of ZnO Nanorods According to Growth Concentration on PES Substrate
Authors: Lee Hyun Min , Kim Sang Hyun , Ock Jae Heon , Jang Nak Won , Kim Hong Seung
Published: April 2015

In particular, the PES substrate, the crystal structure of the amorphous as well as the surface morphology is not good. So research of thin films growth for epitaxial growth by the use of a buffer layer on the amorphous PES substrate is essential.
Therefore, in this study, we deposited ZnO thin-film on PES substrate, and grown ZnO nanorods at various ZnO concentrations during 1 hour. We used SEM, XRD, and HP 4145B for observe the structural and electrical characteristics of ZnO nanorods. UV-visible spectrometer was used to get the band gap and transmittance.
Optimization on Conventional Photolithography Process of 0.98 μm Gap Design for Micro Gap Biosensor Application
Authors: Zaki M. , Hashim Uda , Md Arshad Mohd Khairuddin , Nurfaiz M. , Fathil M.F.M. , Azman A.H. , Ramzan Mat Ayub
Published: April 2015

. Pattern design transfer is the most crucial step in fabrication. Even a small mistake in fabrication can result in device damage or poor performance. To ensure the device performs perfectly, exact design and dimension pattern should be perfectly transferred onto wafer substrate. In this paper, optimization of conventional photolithography process of 0.98μm gap design for micro gap biosensor application is presented. The micro gap pattern on chrome mask is used and the effect of coating profile, UV light, and Post Exposure Bake (PEB) process are investigated. The conventional photolithography process (using a micro gap mask) starts after the silicon oxide, polysilicon and aluminium have been deposited on top of the substrate. Each set of experiment conducted by pairing the element investigated coating profile, UV light, and PEB, with the normal specification of photolithography process. It was observed that 0.98μm gap size can be achieved by choosing suitable process parameters i.e. thickness of coating profile, time and temperature used for UV light and PEB.
Influence of Silicon Nitride (Si3N4) Addition on Microstructure, Mechanical and Thermal Properties of Sn-0.7Cu Lead-Free Solder
Authors: Nasir Norhayanti Mohd , Saud Norainiza , Mohd Salleh Mohd Arif Anuar , Derman Mohd Nazree B. , Izwan Ramli Mohd Izrul , Said Rita Mohd
Published: April 2015

This research has investigated the solder performances of Sn-0.7Cu lead-free solder reinforced with silicon nitride (Si3N4). The Sn-0.7Cu + Si3N4 composite solder were fabricated via powder metallurgy (PM) technique with five different weight percentages (0, 0.25, 0.5, 0.75 and 1.0). Results showed that distribution of Si3N4 along the grain boundaries has increased the hardness of the Sn-0.7Cu + Si3N4 composite solders compared to monolithic Sn-0.7Cu solder alloy. Addition of Si3N4 reinforcement had no significant effect to the melting temperature of the solder. Overall, the entire range of Sn-0.7Cu + Si3N4 composition greatly improves the microhardness of the eutectic solder.
Microstructure and Mechanical Properties of Sn-1.0Ag-0.7Cu (SAC107) Lead-Free Solder Reinforced Silicon Nitride (Si3N4) Particles
Authors: Nasir Norhayanti Mohd , Saud Norainiza , Mohd Salleh Mohd Arif Anuar , Derman Mohd Nazree B. , Izwan Ramli Mohd Izrul , Said Rita Mohd
Published: April 2015

This research has investigated the microstructural analysis and shear strength of Sn-1.0Ag-0.7Cu (SAC107) alloy used as matrix while silicon nitride (Si3N4) as reinforcement particles with different weight fractions (0, 0.25, 0.5, 0.75 and 1.0 wt. %). The composite solders were fabricated using powder metallurgy (PM) method consisting of mixing, compaction and sintering process. With additions of Si3N4 particles, the composite solders experienced a corresponding increase in strength due to fine and homogeneous microstructure. This is signified that the presence of Si3N4 particles effectively refines the microstructure.
Organic Solar Cell: An Overview on Performance and Fabrication Techniques
Authors: Idris Nurul Bariah , Norizan Mohd Natashah , Mohamad Ili Salwani
Published: April 2015

This paper review based on the organic solar cell (OSC). In this review we investigates on the performance perspectives and theoretical of the solar cell using both simulation and spin coating fabrication technique. This paper reviews on progress several organic materials which use as active layer and issues on device efficiencies. This paper also review on development in device structure to get desired higher output in OSC.
Automated Green Sorting Device for Ferrous and Non-Ferrous Material Wastes Using Eddy Current Technique
Authors: Zol Bahri Razali , Nur Hadzwan Ibrahim
Published: April 2015

This project is to design an automated green sorting device that can be used to recognize, differentiate and separate between ferrous and non-ferrous materials, as well as to perform transferring of the mentioned materials. In particular, the technique of separation is using magnetic and Eddy-current concept. Eddy-current is generated on a conductor when the conductor is placed in a magnetic field. These Eddy-currents circulate such a way that they induce their own magnetic field and causing a repulsive force (Eddy force). The analysis done is to analyzed the maximum Eddy force generated to the non-ferrous materials when the materials coming close to the Eddy-current roller. The focused parameters in this analysis are a gap distance between magnet to magnet and a gap distance between magnet to material. The results show this sorting device is completely sort the mix materials (ferrous and non-ferrous materials) up to 90% of consistency.
Comparison Characterization of Geopolymer Source Materials for Coating Application
Authors: Fifinatasha Noor , Al Bakri Abdullah Mohd Mustafa , Ghazali Che Mohd Ruzaidi , Kamarudin Hussin , Binhussain Mohammed , Sandu Andrei Victor
Published: April 2015

Geopolymer is new binder manufactured from an aluminosilicate source materials synthesized of geopolymer by polycondensation reaction of geopolymeric precursor and alkali polysilicate. Material contains mostly Silicon (Si) and Aluminium (Al) in amorphous form is a possible to be geopolymer source material. Several minerals and industrial by-product materials have been investigated geopolymer materials essentially as a replacement for Ordinary Portland Cement (OPC) and for advanced high-tech composites, ceramic applications, and also as an inorganic polymer coating. This paper reports microstructure properties of various geopolymer properties which are kaolin, white clay and silica sand, from Saudi Arabia by conducting several tests. The characterization and particle morphology of the various geopolymer sources materials was determined using scanning electron microscopy (SEM). X-Ray Fluorescence (XRF) is conducted according to perform elemental analysis and chemical analysis while X-ray Diffraction Analysis (XRD) investigates crystalline material structure, including atomic arrangement, crystalline size, and imperfections.
Study the Properties of Abrasive Stone for Aluminum Grinding
Authors: Hasni Nurul Syafiqah , Hidayu Jamil Noorina , Chik Abdullah , Mohd Arif Wi Wan , Seong Hong Eng
Published: April 2015

A doubled-sided lapping machine of grinding stone manufactured of a SiC as an abrasive, specific resin and other thermosetting resin were developed for grinding process of the substrate of hard disk drive (HDD) made up of aluminum since the conventional lapping machine cause the serious quality problem of the magnetic substrate. However, at certain parameter during the grinding process, the abrasive stone was clogging due to the agglomeration of debris from the substrate which cause scratches on the magnetic substrates and affect its performance. The samples were classified into four parts (soft spot, border spot, hard spot, and unused spot). Characterizations of the samples were done using XRF, SEM and FTIR analysis. Based on all the above analysis, it can conclude that the porosity of the stone were not homogeneous and the percentage of Al was highest at the border spot which shows that, the area at the border spot cause the clogging to occur thus produces the hard spot that will damage the magnetic substrate during grinding process.
Modeling of TiN Coating Grain Size Using RSM Approach
Authors: Mohamad Jaya Abdul Syukor , Mohammad Jarrah Mu’ath Ibrahim , Muhamad Muhd Razali
Published: April 2015

Modeling of thin film coating is an important work to identify the required characteristic. In general, suitable coating process parameters are very important to find the best characteristics of coating and towards less material usage, reduced trial in experiment and less machine maintenance. In this paper, Response Surface Methodology (RSM) was implemented in modeling TiN coating grain size. N2 pressure, Argon pressure, and turntable speed were selected as process variables, while the coating grain size as an output response. Significant factors that influence the coating characteristic are determined by using Analysis of Variance (ANOVA) and to develop a polynomial quadratic model. Findings from this study suggested that turntable speed and Argon pressure quadratic term has significant effect to the TiN coating grain size. The result also showed that the actual validation data fell within the 95% prediction interval (PI) and the residual errors percentage was lower than 10%.
Flutter Analysis of an Aircraft Wing Using Computational Fluid Dynamics
Authors: Kumar Sinha Anjani , Ananda Kumar Eriki , Johnrajan A.
Published: April 2015

In today’s aviation world, the design of aircraft wing becomes a challenging one for aeronautical engineers, in order to meet the aero elastic phenomenon such as flutter, wing divergence in both aerodynamics and structural aspects. There are so many FEM packages available for both flow and structural analysis such as ANSYS, NASTRAN, ALGOR, NISA, ADINA, COSMOS, etc. The paper presents the application of computational aero-elasticity (CA) methods to analyze the wing in both aerodynamic and structural aspects, using ANSYS-FLOTRAN; 2-D typical aerofoil sections were analyzed and validated with experimental results. Also the vibration behavior of wing section is analyzed under MODAL, HARMONIC, TRANSIENT and SPECTRUM analysis under the aerodynamic lift force and moments. The support reaction forces and moments at the fuselage-wing intersection are developed in this research.
Investigation of H13 Alloy Cutter Behaviour for Hard Rock Tunneling Applications
Authors: Hoang Hieu , Østhus Rune , Lange Hans , Grøv Eivind , Smading Steve
Published: April 2015

The current paper first analyzed the degradation mechanisms of the worn disc cutter made of forged H13 chromium alloy for hard rock tunneling applications. The paper investigated subsequently the mechanical properties of H13 to have a better understanding of the degradation mechanisms. Hardness tests were carried out on different positions on a cutter. Tensile tests and fracture toughness were carried out to investigate temperature effects. The test results showed that the material has a high wear resistance and a good temperature resistance, but its quasi brittle behavior and the residual stress effect (due to the cutting process) is critical for the chipping damage of the disc cutter.
Investigating the Characteristics of Longitudinal Profile of Primary Particles in Extensive Air Showers
Authors: Al-Rubaiee A.A. , Hashim Uda , Md Arshad Mohd Khairuddin , Rahim Ruslinda A. , Ramzan Mat Ayub , Wesam Al-Mufti A. , Al-Douri Y. , Altaiee A.J.
Published: April 2015

One of the characteristics of longitudinal development of extensive air showers is the number of charged particles and depth of shower maximum in extensive air showers as a function of primary energy, which is often used to reconstruct the elemental composition of primary cosmic rays. Studying of extensive air shower characteristics was performed by investigating the longitudinal development parameters depending on Heitler model for different primary particles. The simulation of the number of charged particles and depth of shower maximum (N and Xmax) in extensive air showers of particle cascades was performed using AIRES code for SIBYLL hadronic model for different primary particles like electron, positron, gamma quanta and iron nuclei at the energy range 1014-1019 eV. The comparison between the simulated longitudinal development of N and Xmax using SIBYLL hadronic model with two hadronic models (QGSJET99 ans SIBYLL16) has shown an opportunity for determination of cosmic ray cascade interactions in extensive air showers.
The Influence of Geopolymerization Process on Liquid and Plastic Limits of Soils
Authors: Syed Zuber Sharifah Zaliha , Al Bakri Abdullah Mohd Mustafa , Kamarudin Hussin , Ahmad Fauziah , Binhussain Mohammed
Published: April 2015

Liquid and plastic limits are very important especially for classification of soil and other engineering purposes where they can provide basis information and also better understanding about the soil. In this study, the geopolymerization process was applied to three different soils; kaolin and the other two soils (Soil 2 and Soil 3) were taken at two different places to investigate any changes of liquid and plastic limit values with solid (soil) to alkaline activator (S/L) ratio range from 1 to 4. The results obtained indicated that the geopolymerization process influenced those values and with further investigation, there might be possibility the properties of soil could be improved due to the chemical reactions.
A Study on Corrosion Behavior of Carbon Steel in Artificial Solution of Geopolymer Paste by Open Circuit Potential
Authors: Zainal Farah Farhana , Hussin Kamarudin , Rahmat Azmi , Al Bakri Abdullah Mohd Mustafa , Sandu Andrei Victor
Published: April 2015

This paper presents an experimental study on corrosion of carbon steel as reinforcement bar in artificial solution of geopolymer paste by Open Circuit Potential (OCP). The OCP measurements have been used in reinforcement bar concrete studies for many years to determine the corrosion behavior of materials. OCP is the potential of the working electrode relative to the reference electrode when no current or potential is being applied to cell. The OCP of reinforcement bar was recorded with time and this experiment has been done for 30 days. A copper/copper sulfate (Cu/CuSO4) reference electrode with a potential V-SHE of +0.318 V (at 25oC) was used in this study. The pH of geopolymer concrete was observed to be in the range of 11.5 to 12.5 depending on the formulations. Thus, in this study the artificial solutions of geopolymer paste that were used are pH 11, pH 12 and pH 13. It has been found that the potential values of three solutions were fluctuated from the beginning until day 30. The highest potential value was indicated by pH 13 whereas the maximum value is 0.542 V and minimum value is 0.205 V while pH 11 shows the lowest potential value with the maximum value 0.356 V and the minimum value-0.047 V. However, all the redox potential values for pH 11, pH 12 and pH 13 were located at passivity region, Fe2O3. The Fe2O3 is the stable phase in which this oxide acts as a protective film or passive layer in this region. It would be expected to provide some protection against corrosion.
Keywords: corrosion, artificial solution, geopolymer paste, reinforcement bar, open circuit potential, passivity
Filling the Missing Data of Air Pollutant Concentration Using Single Imputation Methods
Authors: Noor M.N. , Yahaya A.S. , Ramli N.A. , Al Bakri Abdullah Mohd Mustafa
Published: April 2015

Hourly measured PM10 concentration at eight monitoring stations within peninsular Malaysia in 2006 was used to conduct the simulated missing data. The gap lengths of the simulated missing values are limited to 12 hours since the actual trend of missingness is considered short. Two percentages of simulated missing gaps were generated that are 5 % and 15 %. A number of single imputation methods (linear interpolation (LI), nearest neighbour interpolation (NN), mean above below (MAB), daily mean (DM), mean 12-hour (12M), mean 6-hour (6M), row mean (RM) and previous year (PY)) were calculated to fill in the simulated missing data. In addition, multiple imputation (MI) was also conducted to compare between the single imputation methods. The performances were evaluated using four statistical criteria namely mean absolute error, root mean squared error, prediction accuracy and index of agreement. The results show that 6M perform comparably well to LI. Thus, this show that the effect of smaller averaging time gives better prediction. Other single imputation methods predict the missing data well except for PY. RM and MI performs moderately with the increasing performance in higher fraction of missing gaps whereas LR makes the worst methods for both simulated missing data percentages.