bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of Different Olive Stone Particle Size on the Yield and Surface Area of Activated Carbon Production
Authors: Alslaibi Tamer M. , Abustan Ismail , Ahmad Mohd Azmier , Abu Foul Ahmad
Published: December 2012

Usually, a few preliminary stages have been done for raw materials before the actual production of activated carbon such as materials crushing, milling and sieving to an appropriate particle size. Particle size is important for the subsequent handling of the raw material, such as mixing with a catalyst or impregnation, but it can also affect the properties of the subsequent activated carbon. This research was assessed the effect of different olive stone particle size on activated carbon production by KOH using the yield and surface area response. Three particle size ranges were examined, namely 1-2mm, 2-4.75 and the raw material in its original form. The results demonstrated that the most suitable form was 2mm to 4.75mm which resulted in 38.67% of yield and 886.72 m2 g-1 of a surface area and it has more rigidity compared with finer particle size and has more surface area and yield compared with olive stone in its original form.
A Study of Fe-Based Composite Coating Fabricated by the Self-Propagating High Temperature Synthesis
Authors: Singsarothai Saowanee , Rachpech Vishnu , Niyomwas Sutham
Published: December 2012

The steel substrate was coated by Fe-based composite using self-propagating high-temperature synthesis (SHS) reaction of reactant coating paste. The green paste was prepared by mixing precursor powders of Al, Fe2O3and Al2O3. It was coated on the steel substrate before igniting by oxy-acetylene flame. The effect of coating paste thickness and the additives on the resulted Fe-based composite coating was studied. The composite coating was characterized by X-ray diffraction (XRD) and scanning electron microscope (SEM) couple with dispersive X-ray (EDS).
Characteristics of Treated Palm Oil Fuel Ash and its Effects on Properties of High Strength Concrete
Authors: Zeyad A.M. , Johari M.A. Megat , Bunnori Norazura Muhamad , Ariffin K.S. , Altwair Nurdeen M.
Published: December 2012

Palm oil fuel ash obtained from palm oil mill was treated via screening, grinding and heating to improve its pozzolanic reactivity. The characteristics of the palm oil fuel ash before and after treatment were monitored to assess the changes in the properties of the palm oil fuel ash. The resulting ultrafine palm oil fuel ash was then utilized to produce high strength concrete by replacing the ordinary Portland cement at 0, 20, 40 and 60% on mass-for-mass basis. The results show that the treatment process undertaken reduces the particle size, diminishes the unburned carbon content, while at the same time increases the glassy phases. The utilization of the ultrafine palm oil fuel ash in high strength concrete was observed to improve workability especially at higher ultrafine palm oil fuel ash content. In addition, the long-term compressive strength of the high strength concrete was significantly increased with the ultrafine palm oil fuel ash inclusion. Further, the long-term rapid chloride permeability was significant reduced especially at higher ultrafine palm oil fuel ash content of 60%, which could be translated into superior durability performance.
Luminescence Studies on Lithium-Strontium Borophosphate Glasses Doped with Cr, Ni and Zn Ions
Authors: Wong Poh Sum , Hua Wan Ming , Hussin Rosli , Ibrahim Zuhairi
Published: December 2012

Luminescence material is a solid which converts certain types of energy into electromagnetic radiation over and above thermal radiation. Due to the limited studies on luminescence properties of the transition metal ion doped glass, this present study aiming to understand further the effect of doping different transition metal ions to the luminescence properties. This paper report on the luminescence properties of 20Li2O-20SrO-30B2O3-30P2O5 glasses doped from the photoluminescence spectroscopy. The luminescence spectra of 20Li2O-20SrO-30B2O3-30P2O5-x with x = 1 mol % of different transition metal ions (Cr, Ni, and Zn) which had been prepared by melt quenching technique. The luminescence properties were analyzed using photoluminescence spectroscopy. Based on the emission spectra obtained from 20Li2O-20SrO-30B2O3-30P2O5-Cr, it consists of two emission bands at around 348 nm and 369 nm. While for the luminescence spectra of 20Li2O-20SrO-30B2O3-30P2O5-Ni, it exhibits only one emission band which is at around 363 nm. Lastly, for the luminescence spectra of 20Li2O-20SrO-30B2O3-30P2O5-Zn, it exhibits two emission bands at around 379 nm and 434 nm.
Sensitivity of ZnO Based NH3 Sensor by RF Magnetron Sputtering
Authors: Ahmad Samsiah , Md Sin Nor Diyana , Berhan M.N. , Rusop Mohamad
Published: December 2012

Zinc Oxide (ZnO) thin films were deposited onto SiO2/Si substrates using radio frequency (RF) magnetron sputtering method as an Ammonia (NH3) sensor. The dependence of RF power (50~300 Watt) on the structural properties and sensitivity of NH3sensor were investigated. XRD analysis shows that regardless of the RF power, all samples display the preferred orientation on the (002) plane. The results show that the ZnO deposited at 200 Watt display the highest sensitivity value which is 44%.
Synthesis of Nano-Structured Ni-Co-Al Hydrotalcites and Derived Mixed Oxides
Authors: Salam M. Abdus , Lwin Ye , Sufian Suriati
Published: December 2012

nanostructured hydrotalcite-like compounds that contain nickel, cobalt and aluminum have been synthesized by conventional coprecipitation method without using any surfactants or templating agents. The structure and morphology of the coprecipitated nanohydrotalcites and its derived mixed oxides were characterized by powder X-ray diffraction (XRD), Fourier-transformed Infrared (FTIR) spectroscopy, field-emission scanning electron microscopy (FESEM), high resolution transmission electron microscopy (HRTEM), and nitrogen adsorption-desorption techniques. The results show that the synthesized materials exhibited micro-meso-pore networks. The cobalt-rich calcined hydrotalcites are generally amorphous, having a coral-like morphology whereas nickel-rich hydrotalcites show hexagonal plate-like morphology. The presence of nickel in mixed oxides catalyzed the reduction of Co-Al-O spinels. The Fast Fourier Transform (FFT) analysis of HRTEM revealed the inter planner distances of the crystal of hydrotalcite.
Antibacterial Activity of Copper and CTAB Modified Clays against Pseudomonas aeruginosa
Authors: Malek Nik Ahmad Nizam Nik , Ishak Siti Amirah , Kadir Mohammed Rafiq Abdul
Published: December 2012

Antibacterial activity of modified kaolinite and bentonite with antibacterial agents againstPseudomonas aeruginosawas studied. These clays have been modified with only cetyltrimethyl ammonium bromide (CTAB) and copper (Cu) and the combination of both. Characterization of the studied materials with X-Ray Diffraction (XRD), Fourier Transform-Infrared (FTIR) spectroscopy, Energy Dispersive X-ray (EDX) analyzer and Field Emission-Scanning Electron Microscopy (FESEM) revealed the successful preparation of CTAB-clays, Cu-clays and CTAB-Cu-clays without distorting the structure of these clays. From the antibacterial assay of the studied materials by Inhibition Growth Study and Minimum Inhibition Concentration (MIC) technique, CTAB-Cu-clays have been proven to have the highest antibacterial activity due to the synergistic effect of CTAB and Cu as antibacterial agents. It can be concluded that modification of clays with CTAB and Cu can become new alternative powerful antibacterial agent.
Comparison Studies of Blend and Unblend GPE Systems: Ionic Conductivity, Structural and Morphological Properties
Authors: Samin Siti Mariam , Mansor Mazwan , Isa Khairul Bahiyah Md. , Osman Zurina
Published: December 2012

Studies on comparison of blend and unblend PMMA-based gel polymer electrolytes containing LiClO4salt with EC and PC as plasticizing solvent is reported. The GPE samples are prepared by varying the salt concentrations from 5 wt.% to 30 wt.%. At room temperature, PVdF-HFP/PMMA blend GPE exhibits the highest conductivity of 4.71 x 10-3S cm-1containing 25 wt.% of LiClO4salt while the highest conductivity for unblend GPE is 3.34 x10-3S cm-1containing 20 wt.% of LiClO4salt. The amorphous nature and morphological properties between LiClO4salt, EC and PC in the blend and unblend GPE systems have been validated using XRD and FESEM analysis.
Ionic Conductivity and Dielectric Properties of Plasticized Polyacrylonitrile Based Solid Polymer Electrolyte Films
Authors: Chong W.G. , Osman Zurina , Othman Lisani , Isa Khairul Bahiyah Md.
Published: December 2012

The conducting polymer electrolyte films composed of polyacrylonitrile (PAN) as the host polymer, LiCF3SO3 and NaCF3SO3 as inorganic salts and ethylene carbonate (EC) as plasticizer were prepared by the solution cast technique. The conductivities of the films were characterized by impedance spectroscopy. On addition of more than 14 wt% of salt, the NaCF3SO3-containing PAN films exhibited higher ionic conductivity than the LiCF3SO3-containing PAN films. The values of the dielectric constant, εr and dielectric loss, εi increase as frequency decreases at room temperature. The temperature dependence of the conductivity obeys Arrhenius relation in the temperature range of 303 K to 353 K.
Effect of Antioxidant on Properties of Thermoplastic Natural Rubber Based on ENR/TPU Blends
Authors: Kalkornsurapranee Ekwipoo , Nakason Charoen , Kummerlöwe Claudia , Vennemann Norbert
Published: December 2012

Thermoplastic natural rubber based on epoxidized natural rubber (ENR) and thermoplastic polyurethane (TPU) blend was prepared via dynamic vulcanization process. The main objective is to improve thermal properties of the blends. Two types of antioxidant: phenolic antioxidant (Wingstay®L) and N-(1,3-dimethzlbutyl)-N-Phenyl-p-phenylenediamine (6PPD) were used to improve oxidative degradation of the blends. It was found that thermal properties in term of thermal elastic properties and thermal stability can be improved by adding the antioxidants and 6PPD gave the blend with the highest thermal properties. These were measured based on temperature scanning stress relaxation (TSSR) technique. Incorporation of ENR into the TPU caused reduction of the hardness, improved thermal properties, elasticity and oil resistance compared to the neat TPU. These results indicated that the novel high performance TPNRs with high elasticity can be prepared.
Influence of Processing Oil and Plasticizer on Properties of ENR-25/TPU Simple Blends
Authors: Pichaiyut Skulrat , Nakason Charoen , Vennemann Norbert
Published: December 2012

Thermoplastic natural rubber (TPNR) based on blending of thermoplastic polyurethane (TPU) and epoxidized natural rubber with 25 mol % epoxide (ENR-25) was prepared by simple blend technique. Influence of different types of plasticizer and processing oil (i.e., DOP, TDAE oil and Paraffinic oil) with a fixed loading level of 20 phr was investigated. The main aim was to improve elasticity and lowering the hardness of the blends. It was found that an incorporation of processing oil and plasticizer caused decreasing of mixing torque, mixing temperature, and mechanical properties in terms of tensile strength, and hardness. This is attributed to diffusion of oil or plasticizer molecules into ENR and TPU phases. The oil and plasticizer typically acts as lubricant to promote the ease of flow and influence on various properties. It was also found that an incorporation of processing oil and plasticizer caused decreasing of glass transition temperature (Tg) of rubber and TPU phases, tension set value and Tan δ which refer to greater rubber elasticity and tendency to recover to original shape after prolonged extension. Additionally, the blend with DOP exhibited superior mechanical and other related properties than those of the blends with TDAE oil and paraffinic oil, respectively.
The Effect of Substrate Temperatures on the Structural and Optical Properties of Cosputtered ZnO and AlN Thin Films
Authors: Ismail A. , Abdullah Mat Johar
Published: December 2012

AlN doped ZnO thin films were prepared on glass and Si (100) substrates by RF sputtering. For AlN doped ZnO at RF powers of 200 W (ZnO target) and 200W (AlN target), the ZnO (002) peak showed the highest intensity at the substrate temperature of 400˚ C. The prepared films showed good transmission of above 72 % in the visible range. The calculated values of energy band gaps were in the range (3.42 eV - 3.54 eV) for the films prepared at different substrate temperatures.
The Effect of Hybridization of the Glass Fiber-Flexible Modified Epoxy and Rigid Epoxy Composite Properties under Low-Velocity Impact
Authors: Mamauod Siti Nur Liyana , Abidin Mohd Hanafiah , Romli Ahmad Zafir
Published: December 2012

In the present study, experiment was carried out to investigate the impact properties of flexible and rigid polymer reinforced with E-glass fiber, under low velocity impact. The experimental work includes preparing the cured glassflexible modified epoxy and placed it onto the uncured glass-epoxy composite samples. The experimental results prove that the hybridization improves the impact strength of laminates. The flexibility segments that were introduced into the epoxy system increased the penetration impact resistance value. Hence more impact energy is required to perforate the samples compared to epoxy composite system which is brittle phase.
The Role of Silica Fume in the Adhesion of Concrete Restoration Systems
Authors: Tayeh Bassam A. , Abu Bakar B.H. , Johari M.A. Megat , Zeyad A.M.
Published: December 2012

The weak interfacial transition zone between new and old concrete is always paid much attention and controls many properties of repaired concrete, The present work reports a study on the influence of the silica fume on the adhesion of reactive powder concrete (RPC), as a concrete restoration material, with the ordinary concrete (OC) substrate. The results showed that, the silica fume presence in the interfacial transition zone significantly enhances the adhesion strength between RPC and OC substrate. Furthermore, the silica fume particles consume calcium hydroxide, which is in attendance in the interfacial transition zone, and make the zone more dense, uniform and tough.
Optimization of Material Removal Rate in EDM Using Taguchi Method
Authors: Das Milan Kumar , Kumar Kaushik , Barman Tapan K. , Sahoo Prasanta
Published: December 2012

This paper presents an investigation on the effect and optimization of machining parameters on material removal rate (MRR) in electrical discharge machining (EDM) of EN31 tool steel. For the experiment, four process parameters viz. pulse on time, pulse off time, discharge current and voltage are considered. The settings of machining parameters are determined by using Taguchis orthogonal array (OA). L27 orthogonal array (OA) is considered for the study. The level of importance of the machining parameters on MRR is determined by analysis of variance (ANOVA) test. The optimum machining parameter combination is obtained by the analysis of signal-to-noise (S/N) ratio. The analysis shows that discharge current has the most significant effect on MRR followed by pulse off time and voltage. It is seen that with an increase in discharge current and pulse off time, MRR increases in the studied range. The methodology described here is expected to be highly beneficial to manufacturing industries.
Corrosion Behavior of AZ91 Mg-Alloy Coated with AlN and TiN in NaCl and Hank's Solution
Authors: Rosli Zulkifli Mohd , Mahamud Zainab B. , Mohd Juoi Jariah , Nafarizal Nayan , Loon Kwan Wai , Yusuf Yusliza , Maulod Hairul Effendy Ab
Published: December 2012

Magnesium alloys create increasing interest in structural application where weight reduction is vast concern. However, its low corrosion resistance especially in atmosphere environment restricts their wide application. In this study, AlN and TiN were coated on AZ91 Mg alloy using PVD magnetron sputtering. AlN and TiN existence is confirmed via grazing angle x-ray diffraction (GA-XRD). The corrosion behaviors of uncoated and coated AZ91 Mg alloy in3.5% NaCl and Hanks solutions were investigated using a potentiostat during electrochemical corrosion test. AlN and TiN coated samples showed better performance in Hanks solution with TiN coated samples have the least corrosion rate (penetration rate=0.040mm/yr and mass loss rate=0.191g/m2d) in Hanks solution. These create interest to further works on exploring the potential of coated AZ91 Mg alloy in biomaterial application.
Physical and Mechanical Properties of Glass Composite Material Made from Incinerated Scheduled Waste Slag and SLS Waste Glass
Authors: Mohd Juoi Jariah , Arudra Dilip , Rosli Zulkifli Mohd , Toibah A.R. , Shamsuri Siti Rahmah , Azuraien Japper Jaafar
Published: December 2012

Incineration of scheduled waste and landfilling of the incineration residue (Bottom Slag) is extensively practised in Malaysia as a treatment method for scheduled waste. Land site disposal of Bottom Slag (BS) may lead to environmental health issues and reduces the availability of land to sustain the nations development. This research aims in producing Glass Composite Material (GCM) incorporating BS and Soda Lime Silicate (SLS) waste glass as an alternative method for land site disposal method and as an effort for recycling SLS waste glass .SLS waste glass originates from the urban waste and has been a waste stream in most of the nation whereby the necessity for recycling is in high priority.The effect of BS waste loading on the GCM is studied.Batches of powder mixture is formulated with 30 wt% to 70 wt % of BS powder and SLS waste glass powder for GCM sintering.The powder mixtures of BS and SLS waste glass is compacted by uniaxial pressing method and sintered at 800C with heating rate of 2C/min and 1 hour soaking time. Physical analysis of bulk density, apparent porosity, and water absorption is perfomed according to ASTM C-373 standard. Mechanical testing of microhardness vickers according to ASTM C1327 and Modulus of Rupture (MOR) according to ISO 10545-4 is conducted. Microstructural analysis is carried out using Scanning Electron Microscope and phase analysis by X-ray diffraction method.Phases identified are Anorthite sodian,Quartz,Hematite and Diopside from X-ray diffraction analysis. Higher BS waste loading shows weak physical and mechanical properties .GCM from batch formulation of 30 wt % BS and 70 wt% SLS waste glass has projected optimized physical and mechanical properties. It is observed this batch has projected lowest water absorption percentage of 1.17 % , lowest porosity percentage of 2.2 %, highest bulk density of 1.88 g/cm3and highest MOR of 70.57 Mpa and 5.6 GPa for Vickers Microhardness.
Effect of Annealing Temperature on Surface Morphology of Lanthanum Phosphate (LaPO4) Nanostructures Thin Films
Authors: Zainurul A.Z. , Rusop M. , Abdullah Saifollah
Published: December 2012

LaPO4 particles with different morphologies and sizes have been successfully synthesized via sol-gel spinned coating process. The aim of this paper is to investigate the effect of annealing on the morphology and formation of LaPO4 on thin films. Physical structural properties of LaPO4 was investigated using atomic force microscopy (AFM-XE100). EDS analysis was done to check on the formation of LaPO4.
Effect of Multiwall Carbon Nanotubes (MWCNT) on Mechanical and Electrical Properties of PP/C Composites as Alternative Materials for Bipolar Plate Fuel Cell
Authors: Zulfia Anne , Sutopo  , Indriyana Bangkit , Albar Muhammad Ekaditya , Rohman Saeful
Published: December 2012

The properties of polypropylene can be improved by addition of multiwall carbon nanotube (MWCNT). This research focuses on material design of composite based on polymer matrix and carbon including MWCNT to improve mechanical and electrical properties of composites according to the requirement for bipolar plate material. It is found that the effect of small addition of MWCNT and Cu have been increasing electrical conductivity up to 15.62 S/cm while tensile and flexural strengths increase to 14.97 MPa and 31.78 MPa respectively.
The Study of the Surface Morphology of PVDF/MgO Nanocomposites Thin Films
Authors: Arshad Adillah Nurashikin , Mohd Dahan Rozana , Mohd Wahid Mohamad Hafiz , Habibah Zulkefle , Lyly Nyl Ismail , Sarip Muhamad Naiman , Mohamad Rusop Mahmood
Published: December 2012

This study investigates the effect of varying loading percentages of MgO on the topography and morphology of Poly (vinylideneflouride)/Magnesium Oxide (PVDF/MgO) nanocomposites thin films. PVDF/MgO nanocomposites spin coated thin films with thicknesses ranging from 200nm to 456nm were successfully characterized. The nanocomposite solutions were spin coated on Al-glass substrates at 1500rpm. The topography and surface roughness of PVDF/MgO nanocomposites were characterized by using AFM. FE-SEM was used to investigate the surface morphology of the nanocomposites thin films and ATR-FTIR was used to determine the chemical bonding of PVDF/MgO nanocomposites. MgO (7%) was found to be the optimum loading percentage for PVDF/MgO nanocomposite film with favorable distribution of MgO particles, minimum defects and high content of β-phase as evident by FESEM and FTIR.
Effect of Calcinations Temperature on the Structural and Photocatalytic Activity of TiO2 Powders Prepared by Sol-Gel Method
Authors: Sangchay Weerachai
Published: December 2012

TiO2powders were prepared by sol-gel method. The prepared powders were synthesized at the temperature of 200 °C to 700 °C for 2 h with a heating rate of 10 °C/min. The characterizations of synthesized powders were characterized by XRD and SEM. Finally, photocatalytic activity was evaluated by UV-vis spectrophotometer. The results show all samples have the agglomeration. It was found that the effect of calcinations temperature on phase transformation, crystallite size, morphology and photocatalytic activity of the synthesized powders. It can be note that TiO2powders calcined at 700 °C were found to give the highest photocatalytic efficiency (81.7%) under UV irradiation.
Evaluation of Silica Fume Effect on Compressive Strength of Structural Lightweight Concrete Containing LECA as Lightweight Aggregate
Authors: Mortazavi Maryam , Majlessi Mojtaba
Published: December 2012

The purpose of this paper is to evaluate the effect of silica fume on compressive strength of structural lightweight concrete, containing saturated LECA (Light Expanded Clay Aggregate) as lightweight aggregate (LWA). In experimental phase of study 120 cubic specimens (10*10*10) were made and cured. For every mix design, different cement percentages were replaced with silica fume, containing same amount of saturated LECA. The mixes incorporate 0%, 5%, 10%, 15%, 20%, 25% silica fume. Constant level of Water/Cement ratio (0.37) was considered. For each mix design 20 specimens were prepared and cured for 7, 14, 28, 42 days in standard 20 C water. Also 20 specimens with the same mix design of 0% silica fume as normal weight concrete were prepared and cured to compare the results. For these specimens LECA were replaced with same volume and size of sand. The testing results showed; increasing silica fume causes considerable increase in compressive strength. The rate of strength gain slows down at high percentage of silica fume. Also silica fume leads concrete to get higher initial compressive strength at certain time compared with normal weight concrete.
Effect of Soya Bean Flour Content on Mechanical Properties and Biodegradability of Poly(vinyl Alcohol) Film
Authors: Suki Fairus Mazlia Mat , Ismail Hanafi , Hamid Zuratul Ain Abdul
Published: December 2012

Biodegradable film blends of soya bean flour with poly (vinyl alcohol) (PVA) were prepared by solution mixing and solution casting. The main goal of this study is to investigate the effect of soya bean flour content in the PVA film. Mechanical properties of the obtained blends were assessed by tensile testing, whereas the biodegradability were assessed by subjected the films in natural weathering. The incorporation of soya bean flour decreased the tensile strength and elongation at break of PVA film. However, the tensile modulus increased with the addition of soya bean flour. The reduction in tensile properties of the PVA/soya bean flour blend films revealed that the presence of soya bean flour show positive effect in degradation.
Influence of Waste Paper Sludge Ash (WPSA) and Fine Recycled Concrete Aggregate (FRCA) on the Compressive Strength Characteristic of Foamed Concrete
Authors: Sharipudin Siti Shahidah , Ridzuan Ahmad Ruslan Mohd
Published: December 2012

In the effort to produce sustainable concrete, considerable attempt has been placed on replacing the main ingredients in concrete mixtures with more sustainable materials with the objective to reduce the carbon footprint. One of the replacement materials is waste paper sludge ash (WPSA), a local industrial by-product generated abundantly by newsprint mills which possesses considerable cementitious properties. Parallel to this, the high amount of construction waste, particularly concrete waste has become a difficult environmental issue to cope with in todays world. For this reason, recycling of concrete waste as a new alternative aggregate is being effectively utilized in concrete production. Thus, this paper reports on a study conducted to evaluate the compressive strength characteristics of the potential of using WPSA as a binder and fine recycled concrete aggregate (FRCA) as a virgin sand replacement in producing foamed concrete. The findings of this study exhibited that the inclusion of WPSA and FRCA for replacement ratios up to 20% and 15% respectively has significantly influenced the strength properties of foamed concrete.
Numerical and Experimental Studies on Extrusion of Fan-Shaped Shell of Magnesium Alloy
Authors: Zhang Bao Hong , Wu Yao Jin , Zhang Zhi Min
Published: December 2012

This paper presents a case study of optimizing the forming process for a fan-shaped shell component. Numerical simulation was used to study the backward extrusion process of a fan-shaped shell. The underfill defect produced at the opening of the extruded shell due to the billet shape was solved and the minimal base thickness required to avoid the presence of the underfill defect at the bottom corner of the component was defined through the numerical simulation. The extrusion drawing and forming process of the fan-shaped shell were designed on the basis of the results of the numerical simulation. Forming experiments had been performed on the fan-shaped shell at 380 °C and cracking was found on the outside wall in the center of the extruded shell. Choked groove on the inner wall of the die and reducing the lubrication had been used to avoid the presence of cracking. The fan-shaped shell of AZ31 magnesium alloy has been successfully formed by the three-stage forming process of hot upsetting, hot backward extrusion and cold sizing.
The Influence of Fly Ash Addition on the Compressive Strength of Concrete Containing Recycle Concrete Aggregates
Authors: Rohman Rosyid Kholilur , Cahyono Setiyo Daru , Triyono A.R. Hanung
Published: December 2012

The rapid economy growth in Indonesia encourages the developments in all fields. One of them is the development of infrastructure on housings, transportations, and irrigation. Constructions of concrete building are used on the road, bridges, buildings, housing, and water buildings. A concrete is a material structure of building that made from mix of sand, gravel, cement and water as adhesive. All the materials of the concrete were derived from the nature. To avoid the excessive exploration of nature resource the method of recycling of used concrete to become new one were needed. The used concrete was used for coarse aggregate. To improve the quality of concrete from the used one, additional material was required, that is, fly ash. The test material were formed of cube of 15x15x15 cm in size. From the result of research, the analysis can be done in order to find the relationship between quantity of fly ash to be added and the quality of concrete can be formulated as y =-34.921x2 + 11.45x + 25.465, in which y is compressive strength and x is the percentage of fly ash. Thus, for maximum addition of fly ash of 16.4 %, it obtains the maximum compressive strength of concrete of 26.4 MPa and the age of concrete is 28 days. The method of recycling of used concrete and the use of fly ash to become the material of new concrete are safe environmentally, which can overcome the nature filthy especially from the waste of used concrete and coal. Therefore, this is in line with the principal of nature preservation, those are Reduce, Reuse dan Recycle.
Investigation of the Geometry Modeling of Metal Organic Halide Vapor Phase Epitaxy (MOHVPE) Reactor
Authors: Annuar N. Zieyana Mohamed , Mohd Sabri Mohd Faizul , Abu Bakar A. Shuhaimi
Published: December 2012

The new approach for designing a horizontal metal organic halide vapor phase epitaxy (MOHVPE) reactor chamber is proposed. The model is conjugated with comprehensive detailed simulation for horizontal tube reaction chamber by using computerized software. The modeling approach is based on the hybridization of MOCVD and HVPE. The development consists of 5 inlet nozzles with dimension of 54 cm long. The numerical study of horizontal MOHVPE growth shows dependence on temperature and species flow rates. The inlet area is set to room temperature while the whole chamber is set in the temperature range from 1273 K to 1473 K. It is seen that the flow pattern is influenced more by the temperature distribution and geometry of the chamber.
Parameter Optimerization for Photo Polymerization of Microstereolithography
Authors: Khairu K. , Raman Ibrahim , Mohamed Mohammad Asraf Shaik , Ibrahim Mustaffa , Saidin Wahab
Published: December 2012

This paper presents a research on composition photo absorber (Sudan I) effect based on curing parameter, the Liquid Crystal Display (LCD) projector as energy light source initiated the photo reactive polymer. The polymer based material with composition of 1, 6-Hexanediol dicrylate, Phenylbis (2,4,6-trimethylbenzoyl) phosphine oxide with varied Sudan I concentration was used to build 3D structures. The structure was fabricated with three different photo absorber concentrations 0.002%, 0.003%. and 0.006%. of Sudan I. In this experiment the photoreactive polymer solidification phenomena was evaluated.The experiment result obtained, that exposed time of the varied photo absorber was most significantly affect the surface roughness values and the solidification layer time regardless the layer thickness. This work represents that photo absorber composition solution gave a different characteristics for 3D microstructure fabrication.
Microstructural Evolution in Partially Homogenized AZ91 Alloy during Hot Rolling and Interpass Annealing
Authors: Ferdowsi Mahmoud Reza Ghandehari , Mazinani Mohammad , Ebrahimi Gholam Reza
Published: December 2012

The as-cast AZ91 Mg alloy ingot with mean grain size of 98 μm after solution treatment was subjected to plastic deformation by multi-pass hot rolling. The process facilitated steady grain refinement by dynamic recrystallization with increasing rolling passes, and the final grain size was reduced to 6.4 μm by 4 rolling passes. Optical microscopy demonstrated that in the beginning of the rolling process twin DRX was the major dynamic recrystallization mechanism. In contrast, in 3rdand 4thpasses of rolling new grains nucleated at grain boundaries, due to low grain size of the alloy.
Role of Salt Concentration Lithium Perchlorate on Ionic Conductivity and Structural of (Glycidyl Methacrylate-co-Ethyl Methacrylate) (70/30) Based on a Solid Polymer Electrolyte
Authors: Imperiyka M. , Ahmad Azizan , Hanifah S.A. , Rahman Mohd Yusri Abdul
Published: December 2012

A new solid polymer electrolytes (SPE) comprising copolymer of poly(glycidyl methacrylate, GMA) and (ethyl methacrylate, EMA) as polymer host and LiClO4as dopant was prepared by solution-casting technique. The copolymer was prepared by photopolymerization method and was characterized using NMR. The SPEs were characterized using electrochemical impedance spectroscopy (EIS), fourier transforms infrared (FTIR) and X-ray diffraction (XRD). The highest conductivity achieved was 4.0x10-4at 373K with highest conductivity at room temperature (2.7x10ˉ5 S cm-1at 30 wt. % of LiClO4). The active coordination site for the cation (Li+), three electrons donating functional carbonyl, ether and epoxy group of the GMA-co-EMA host have been evaluated base on their properties that were recorded in (FTIR). The structural analysis showed reduction in copolymer crystallinity phases at its highest conductivity
Evaluation on the Thermal Conductivity of Sand-Cement Blocks with Kenaf Fiber
Authors: Jalilluddin Aimi Munirah , Ayop Seti Mariam , Kamaruddin Kartini
Published: December 2012

Mechanical means of ventilation and air-conditioning system in Malaysian buildings are used continuously to provide and maintain the comfort of indoor environment to the occupants of the buildings. It was found that the system used led to higher rate of energy consumption. Hence, development of masonry units with high thermal insulation properties is a necessity. This paper represented the study on the thermal conductivity and the density of sand-cement blocks incorporated with different proportions of kenaf (Hibiscus cannabinus L.) fiber as additive. The amount of kenaf fiber inclusions were the main focus to observe the achievement of best results for both properties. It was found that kenaf fiber content had an advantage to reduce the self-weight of blocks whilst reducing the thermal conductivity property. Hence, it can be seen that there is a potential in developing masonry units for single wall components in Malaysian buildings with lightweight features and thermal insulator properties.
Stability of Created Nano-Holes from Electrodeposited Organic SAMs (Thiols) on Gold Polycrystalline Films
Authors: Zabat Mokhtar , Morin Mario
Published: December 2012

Self-assembled monolayers CH3(CH2)n-1SH with different chain lengths have been elaborated by electrodeposition on gold films. Enhanced blocking properties were obtained by sweeping the potential between oxidative and reductive regions. Once complete and almost defects free layers were obtained, partial reduction was found to lead to the creation of almost circular nanosized holes in the SAMs; which can be used as nanoelectrodes. As verified by the EIS analysis of the charge and the mass transfer through the electrodeposited layers, the stability of the system permeability was found deeply depending on the chain length.
Effects of Activating Flux on Inconel 718 Alloy and AISI 304 Stainless Steel Dissimilar TIG Welds
Authors: Lin Hsuan Liang , Hsu Zhau Hong , Wang Wun Kai
Published: December 2012

The purpose of this work is to investigate the effects of activating flux on the penetration, depth-to-width ratio (DWR), angular distortion and hardness of Inconel 718 alloy and AISI 304 stainless steel (SS) dissimilar welds in the tungsten inert gas (TIG) welding process. In the activated TIG (A-TIG) process, the single component fluxes such as SiO2, NiO, MoO3 and MoS2 and the mixed component fluxes that using 50 % of each single component flux to create six new mixtures were used in the experiment. The experimental results showed that the A-TIG welds coated with 100% SiO2 flux was provided with best DWR of dissimilar welds. In addition, the experimental procedure of A-TIG welding process not only produced a significant increase in penetration and DWR of weld bead, but also improved the angular distortion and hardness of Inconel 718 alloy and AISI 304 SS dissimilar welds.
Preparation and Characterization of Rice Husk Powder Incorporated Natural Rubber Latex Foam
Authors: Ramasamy Shamala , Ismail Hanafi , Munusamy Yamuna
Published: December 2012

Rice husk powder (RHP) is an abundant agricultural by product that is produced in bulk quantity as part of rice milling. This research is carried out to incorporate RHP with natural rubber latex (NRL) compound. Different loading of RHP is added to NRL compound and is foamed to make natural rubber latex foam (NRLF) using a well known technique called the Dunlop method. The tensile properties of modified NRLF is studied and compared with the controlled NRLF which has zero RHP loading. The morphology and micro structural characterization has been performed by Tabletop microscopy (TM1000). The tensile strength decreases at 2.5 pphr but increases again as the filler loading increases. Elongation at break decreases whereas modulus at 100% elongation (M 100) and hardness increases as the filler loading increases.
The Effect of pH on Zinc Phosphate Coating Morphology and its Corrosion Resistance on Mild Steel
Authors: Abdalla Khalid , Azmi Rahmat , Azizan Aziz
Published: December 2012

Zinc phosphate coating is commonly used for corrosion protection of metallic materials, mainly mild steel. In this study, influence of the pH of phosphating bath on the surface morphology and corrosion resistance of zinc phosphate coatings on mild steel was investigated. The phosphate layers were deposited on steel from phosphating bath at different pH values (1.75 ~ 2.75). The surface morphology and composition of phosphate coatings were investigated via scanning electron microscopy (SEM), and energy-dispersive X-ray (EDX). The corrosion resistance of the coating was evaluated by polarization curves (anodic and cathodic) in an aerated 3.5% NaCl solution. The results showed that better surface coverage and corrosion resistance for the steel phosphated at pH 2.75.
Differences between 2D and 3D Interlaminar Fracture Analysis of Unidirectional Carbon/Epoxy Arcan Specimens: Numerical and Experimental Approaches
Authors: Bakhtiari Reza , Choupani Naghdali , Darabi Ehsan
Published: December 2012

In this paper, the mixed-mode interlaminar fracture behavior of unidirectional carbon-epoxy composite was investigated based on experimental and numerical analysis. A modified version of Arcan specimen was employed to conduct a mixed-mode fracture test using a special loading device. A full range of mixed-mode loading conditions including pure mode-I and pure mode-II loading were created and tested. This test method is a simple procedure, clamping/unclamping the specimens is easy to achieve and only one type of specimen is required to generate all loading conditions. Also, the correction factors were determined via two-and three-dimensional analysis and the results were compared. Results indicated that the interlaminar cracked specimen is tougher in shear loading condition and weaker in tensile loading condition.
Thermoplastic Elastomer Based on Epoxidized Natural Rubber/Polyamide-12 and Co-Polyamide-12 Blends
Authors: Romin Rawviyanee , Nakason Charoen , Thitithammawong Anoma
Published: December 2012

Thermoplastic elastomers based on blending of epoxidized natural rubber with 30 mol% epoxide (ENR-30) with polyamide-12 (PA-12) (i.e., ENR-30/PA-12) and blending of ENR-30 with co-polyamide-12 (ENR-30/CO-PA-12) were prepared by dynamic vulcanization technique. It was found that the dynamically cured ENR-30/PA-12 blends exhibited higher tensile strength, Youngs modulus and hardness than those of the ENR-30/CO-PA-12 blends. However, the elongation at break of the ENR-30/PA-12 blend was very poor and hence the tension set could not be determined. On the other hand, the ENR-30 contents in the dynamically cured ENR-30/CO-PA-12 influence on various properties. These include lowering of stiffness and tensile properties together with enhancing elastic properties (i.e. lower tension set and tan ) of the blends.
Energy Absorption Characteristics of Interface Modified GFRP Laminates under Low Velocity Impact
Authors: Mubarak Ali , Sunil C. Joshi
Published: December 2012

The effect of modification of the ply-interfaces in glass fibre reinforced polymer (GFRP) laminates with dispersed micro-particles on its impact characteristics was investigated. The reference and modified laminates were fabricated using woven GFRP prepregs. Impact tests were conducted using an instrumented drop tower device at various incident energy levels. The results were analysed using 5 different energy terms, namely maximum energy (Emax), elastic energy (Eel), absorbed energy (Eab), energy before peal load (Ebpl), energy after peak load (Eapl) and the damping index (DI). This investigation elaborates the relationship between the different energy terms as a function of the incident impact energy and time. The analysis of the energy characteristics indicates reduction in impact damage in the modified laminates. The modified laminates show higher Ebpland lower DI when compared to the reference laminates.
Effects of Various Additives on Drying Shrinkage, Compressive and Flexural Strength of Lightweight Foamed Concrete (LFC)
Authors: Roslan Ahmad Farhan , Awang Hanizam , Mydin Md Azree Othuman
Published: December 2012

This paper presents an investigation on lightweight foamed concrete (LFC) with different type of additives. LFC with 600, 1000 and 1400 kg/m3 density were cast and tested. Fly ash, lime and polypropylene fibre were used on each density with different percentages. All the additives effects were compared with normal LFC as control mix. Mechanical properties of LFC were evaluated with several tests up to 180 days. The results show that the drying shrinkage, compressive strength and flexural strength are affected by the hydration process of each additive in the harden LFC. Fly ash as pozzolanic material helps to strengthen the LFC, though it needs longer curing period to achieve ultimate strength. Lime gives slight contribution to strength as detail investigation on microstructure formation will give clear answer on how the mechanical properties were affected. The addition of polypropylene contributes to flexural strength and shrinkage of LFC. Polypropylene fibre only contributes to compressive strength at low LFC density.
Preparation and Possible Agricultural Applications of Polymer Hydrogel Composite as Soil Conditioner
Authors: Laftah Waham Ashaier , Hashim Shahrir
Published: December 2012

The effect of polymer hydrogel composites (PHGC) on sandy soils holding capacity, urea leaching loss rate (ULLR) and plant growth was studied. The effect oil palm empty fruit bunch (OPEFB) microfiber on biodegradation of poly acrylic acid hydrogel was investigated. Soil holding capacity, plants growth and ULLR were positively affected by PHGC. The composite of PHG-g-OPEFB has better Biodegradation in contrast with plain PHG.
Effects of Cavity Length on Optical Characteristics of Deep Violet InGaN DQW Lasers
Authors: Alahyarizadeh Ghasem , Zainuriah Hassan , Thahab Sabah M. , Amirhoseiny Maryam , Ghazai Alaa J.
Published: December 2012

The performance characteristics and their dependence to cavity length of deep violet InGaN DQW lasers emitting at 390 nm have been investigated using the Integrated System Engineering Technical Computer Aided Design (ISE TCAD) software. The focus of simulation was on the study of optical properties which were carried out with varying cavity length from 200µm to 600µm. The simulation results indicated that the cavity length strongly affects the optical properties of the violet InGaN DQW laser. They showed that the parameters related to the output power such as optical intensity increases by increasing cavity length due to increase of applied current to the laser system. The results also indicated that the parameters such as optical material gain, stimulated and radiative recombination which are related to quantum efficiencies and laser performance decrease by increasing cavity length. It was shown that the laser structure with the longer cavity length has the lower optical loss.
Effect of Electrolyte Concentration on the Growth of Porous Anodic Aluminium Oxide (AAO) on Al-Mn Alloys
Authors: Voon C.H. , Derman Mohd Nazree
Published: December 2012

In this study, the effect concentration of electrolyte on pore nucleation process during anodizing was investigated. It was found that the concentration of oxalic acid influenced the morphologies and regularities of porous AAO formed on aluminum-manganese substrate. When the concentration of oxalic acid is 0.1 M, the porous AAO exhibited a disordered pores arrangement and no long range order was observed. However, when the concentration was increased to 0.3 M and 0.5 M, hexagonal pores arrangement and long range order were obtained. Although the hexagonal pore arrangement was still retained, further increasing the concentration of oxalic acid to 0.7 M render the long range order disappeared. The rate of increase of oxide mass of porous AAO increased with the concentration of oxalic acid.
Effect of Post-Heated Concrete Cylinders Repaired with CFRP Reinforcement
Authors: Zuki Sharifah Salwa Mohd , Jayaprakash J. , Hock Lee Kit , Chong Yong Ong
Published: December 2012

This paper presents the experimental results of post-heated concrete cylinders repaired externally using Carbon Fibre Reinforced Polymer (CFRP) fabrics. Eighteen concrete cylinders of size 155mm x 300mm were exposed to different temperatures of 100, 200, and 300°C for 3 hours. Subsequently, the exposed concrete cylinders were naturally cooled down to room temperature and repaired externally using CFRP reinforcement. All these cylinders were tested to failure under axial loading. Results show that the residual strength of post-heated CFRP repaired concrete cylinders was significantly increased between 47 to 51% over the control cylinders. However, the ductility of CFRP repaired concrete cylinders was increased at the elevated temperatures.
In Vitro Biodegradability of Poly(lactic Acid)/Hydroxyapatite Biocomposites Prepared by Solvent-Blending Technique
Authors: Kaavessina Mujtahid , Khanifatun Fitriani , Ali Imtiaz , Alzahrani Saeed M.
Published: December 2012

Poly (lactic acid) was solvent-blended and formed as thin ribbons with different weight fraction of hydroxyapatite, namely 5, 10 and 20wt%. In-vitro biodegradability of biocomposites was performed in phosphate buffer solution (PBS) at 37°C. The presence of hydroxyapatite tended to increase biodegradability of poly (lactic acid) in its biocomposites. Thermal stability of biocomposites was always higher than that neat poly (lactic acid) either before and after hydrolytic degradation tests. After biodegradation tests, some micro-holes and cracks were appeared in the surface morphology of biocomposites as well as the increasing crystallinity occurred.
Effect of Silane Coupling Agent on the Curing, Tensile, Thermal, and Swelling Properties of EPDM/Mica Composites
Authors: Ismail Hanafi , Hamid Z.A.A. , Ishak S.
Published: December 2012

In this work, the influence of silane (bis (3-triethoxysilylpropyl) tetrasulfide) or Si69 coupling agent on properties of EPDM/mica composites was studied. Both EPDM/mica composites with silane and without silane were compounded using two roll mill at various filler loading (i.e., 100/0, 100/10, 100/30, 100/50, 100/70). The tensile and thermal properties as well as fracture surfaces of composites were tested using Instron Universal Testing Machine, Thermal Gravimetric Analysis (TGA) and Emission Scanning Electron Microscope (SEM). The results indicated that the optimum cure (t90), scorch time (ts2) value was lower, while maximum torque (MH) value slightly higher for EPDM/mica composites with silane compared to EPDM/mica composites without silane. The tensile properties, M100 and M300 value increased for EPDM/mica composites in the presence of silane and the optimum filler loading for those properties occurred at 50 phr. In addition, thermal stability and swelling ratio for both composites improved with increasing filler loading. However, EPDM/mica composites with silane show better thermal stability and swelling ratio due to stronger linkage taking place at the rubberfiller boundary and it promotes filler dis-agglomeration.