bluuebunny/crossref_metadata_2025 huggingface dataset:
Studies on Effect of Zinc Oxide (ZnO) Nanostructures Morphology by Modification of Sol-Gel Solution
Authors: Kamardin Ili Liyana Khairunnisa , Ainun Rahmahwati Ainuddin
Published: October 2015

Zinc Oxide (ZnO) known as wide band gap semiconductor with large excitation energy 60 meV, noncentral symmetry, piezoelectric and biocompatible for biomedical application are the unique characteristic that attract many researcher’s attention on ZnO nanostructure synthesis and physical properties. ZnO thin films were deposited on Si Glass substrate by a sol-gel process. The starting solution were prepare by dissolved zinc acetate dehydrate (ZnAc) and diethanolamine (DEA) in water (H2O) and 2-propanol (2-PrOH). 0 to 60 drops of NaOH were dropped into 100 ml sol-gel solution to study effect of sol-gel modification. ZnO thin films were obtained after preheating the spin coated thin films at 100 °C for 10 minutes after each coating. The coated substrates were undergone for Hot Water Treatment (HWT) process at 90 °C for 6 hours to grow ZnO nanostructures. The effects of sol-gel modification by drop of NaOH into the solution were studied. ZnO nanorods and nanoflakes were obtained after hot water treated at 90 °C for 6 hours with different amount of NaOH dropped directly in the sol-gel solution. On the basis of the changes in morphology and microstructure induced by hot water treatment, it is concluded that the amount of NaOH dropped into sol-gel effected morphology of ZnO growth.
Morphological Effect of Composite Coated SUS430 Steel during Thermal Oxidation Process
Authors: Ramdan Raden Dadan , Setiawan Asep Ridwan , Suratman Rochim
Published: October 2015

High temperature behaviour is important characteristic to be evaluated for internconnect materials in solid oxide fuel cell (SOFC) application. The present works concern in evaluating the morphological effect of composite coated SUS430, prospective material for SOFC application, on the high temperature behavior of the composite. Thermal spray method has been conducted as the major coating processes whereas thermal oxidation and sol gel coating is the addition coating method performed in the present works. Through variation of coating processes in the present works, different morphology of composite coated SUS430 alloy were obtained. Scanning electron microscope (SEM) characterizations have been performed in order to evaluate the morphological aspect of the coated samples before and after thermal oxidation process. In addition, X-ray diffraction characterization has been performed in order to identified the existing phase before and after thermal oxidation. From both characterization results, it was obtained that particle size of the composite layer influences the compactness and porous characteristic of the layer and in turn influences the oxidation characteristic of the layer during high temperature services.
Dry Sliding Wear Behavior of A356-ZrO2 Metal Matrix Composite
Authors: Ghandvar Hamidreza , Farahany Saeed , Idris Mohd Hasbullah , Daroonparvar Mohammadreza
Published: October 2015

Dry sliding wear and friction behavior of cast A356 Al-Si alloy and composite containing 5wt. % ZrO2 particles were studied by means of a pins-on-disk apparatus over loads of 5N, 20N and a sliding speed of 0.628m/s. The experimental results showed that the composites exhibited a higher wear resistance in comparison to that of the unreinforced A356 alloy. The friction coefficient of tested materials increased with increasing applied load from 5 to 20 N. FESEM investigations revealed that the wear mechanism of the A356 matrix alloy changed from sever abrasive, adhesive wear into mild abrasion and adhesive wear with addition of 5wt. % ZrO2 reinforcement particles.
Interlaminar Damage Behavior of CFRP Composite Laminates under Cyclic Shear Loading Conditions
Authors: Abdullah Muhammad A'imullah , Arjmandi Mohammad Reza , Koloor Seyed Saeid Rahimian , Wong King Jye , Tamin Mohd Nasir
Published: October 2015

This paper provides quantitative description of interlaminar damage process in CFRP composite laminates under cyclic shear loading. Quasi-static end-notched flexural (ENF) test on 16-ply CFRP composite laminate beam, [0]16 and its complementary validated FE model provide the reference “no-interlaminar damage” condition. Two identical ENF samples were fatigue to 50000 cycles, but at different load amplitude of 90 and 180 N, respectively (Load ratio, R = 0.1) to induce selectively property degradation at the interface crack front region. Subsequent quasi-static ENF tests establish the characteristic of the interlaminar damage degradation. The residual peak load for the fatigued ENF samples is measured at 1048 and 914 N for the load amplitude of 90 and 180 N, respectively. Cyclic interlaminar shear damage is represented by a linear degradation of the residual critical energy release rate, GIIC with the accumulated damage. Reasonably close comparisons of the predicted residual load-displacement responses with measured curves serve to verify the suitability of the assumed bilinear traction-separation law for the cyclic cohesive zone model (CCZM) used.
Hydrothermal Synthesis Effect on Growth of Zinc Oxide Structure
Authors: Ainun Rahmahwati Ainuddin , Hashim Muhammad Firdaus , Kamardin Ili Liyana Khairunnisa
Published: October 2015

The properties and performances of Zinc Oxide (ZnO) film have made the material spread widely in several applications such as in providing energy to consumers in which it is harvest energy from the sun rays. By using hydrothermal method in order to fabricate ZnO films is one of the process that consume less energy and lower temperature compare to the other methods. In this research, the seed layer of ZnO was deposited on Fluorine doped Tin Oxide (FTO) substrate and heat treated at 100 °C for 10 min prior to the hydrothermal growth. Hydrothermal growth temperature was varies at 70 °C, 90 °C and 110 °C for 12 hours. The ZnO-coated FTO films were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM) and energy disperse spectroscopy (EDS). The I-V characteristic of the ZnO-coated FTO films was characterized with solar simulator. The experimental results reveal that the hydrothermal growth temperature exerts a strong influence on the properties of the ZnO-coated FTO films. The effects of the hydrothermal growth temperature are discussed.
Pulsed Current Electrodeposition of Mn-Cu Alloys on SUS 430 Substrate as Coating Material for SOFC Interconnect Application
Authors: Setiawan Asep Ridwan , Ramelan Aditianto , Suratman Rochim , Herwandi Naufal Muhammad
Published: October 2015

In the present study, several series of pulse current electrodeposition experiment have been carried out at 25 °C in various electrolyte bath under different current densities to find the suitable electrodeposition condition for fabricating Mn-Cu alloys coating. The deposition kinetic of Mn-Cu alloy was assessed from the measurement of cathodic polarization behavior in selected electrolyte bath. The uniformity of Mn-Cu alloy coating, and its composition were studied by scanning electron microscope (SEM) equipped with energy dispersive spectroscopy (EDS) analysis. The results shows that a dense, adherent, smooth and uniform Mn-Cu alloy coating can be deposited on SUS 430 substrate with relatively high deposition rate. The evaluation of coating area specific resistance (ASR) at 700 °C shows a value of 0.04 Ωcm2. This result indicates that Mn-Cu alloy is promising as alternative coating materials for SOFC interconnect.
Investigation of Deposition Parameters Dependence on Sputtered Cu2ZnSnSe4 Thin Films Properties
Authors: Kim Kyoo Ho , Wibowo Rachmat Adhi , Park Nokeun , Fianti Fianti , Muslih Ersan Y.
Published: October 2015

Cu2ZnSnSe4(CZTSe) thin films were deposited by sputtering process using powder compacted target of CuSe, ZnSe and SnSe on Corning 1737 glass for Indium-free thin film solar cell application. Film composition,structure and properties were investigated by varying deposition parameters,such as substrate temperature,film thickness and RF power in order to deposit films with a stoichiometric composition and single phase of CZTSe. At an optimal condition of experiment,substrate temperature toward 1500 C,RF power 75W, CZTSe films near stoichiometric composition with a polycrystalline stannite single phase were successfully deposited. Film thickness was little dependency with structure and composition except optical transmittance of the films. And it was observed to have a absorption coefficient of up to 104 cm-1, band gap energy of 1.5 eV, carrier concentration in order of 1019 cm-3, mobility of 100 cm2V-1s-1 and resistivity of 10-1-103 Ωcm.It was also showed that all films were identified as p-type semiconductor.
Solution-Processable Field-Effect Transistor Behavior of π-Conjugated Oligothiophene
Authors: Lim Eun Hee
Published: October 2015

The effect of substitution pattern of the linear-type π-conjugated oligothiophenes is examined. The material solubility, thermal properties, and charge transport characteristics of two hexyl subsituted quinquethiophenes (DH5T) were determined along with the characteristics of an organic field-effect transistor (OFET). The solubility of 4,7-bis (3’-hexyl-2,2’-bithiophene-5-yl) thiophene (β-DH5T), which featured a lateral substitution, was significantly better than that of α,α’-dihexylquinquethiophene (α-DH5T) by altering the directional position of the alkyl group, which makes it a good candidate for solution-processed OFETs. Despite the well-defined vertical alignment of α-DH5T, the hole mobility of the β-DH5T film (3.02 × 10–3 cm2 V–1 s–1) was one order of magnitude higher than the hole mobility of the α-DH5T film (2.47 × 10–4 cm2 V–1 s–1) prepared by solution processing.
Parameter Design for Hardness of Metal Filled Epoxy Matrix
Authors: Mohd Khushairi Mohd Tanwyn , Sharif Safian , Mohd Ani Jaafar Sidek
Published: October 2015

Epoxy is blended with metal fillers to enhance its performance and application for tooling. Material used contains aluminium particles (Rencast CW47), blended with brass separately. Brass is added into the matrix based on 10%, 20% and 30% of the epoxy mix weight ratio. Using Taguchi method, controls factor such as pre-curing temperature (A), filler percentage (B), degassing time (C), curing time (D) and post curing temperature (E) are selected parameters in order to determine optimum conditions. Noise strategy is adopted for material cooling via ambient (N1) and oven temperatures (N2), which gave different hardness values of the epoxy composite. Optimum parameters were decided based on the prediction of S/N ratio, where A = Room temperature, B = 20%, C = 60 minutes, D = 14 hours and E = 1800C. The most significant control factor is de-gassing time for both fillers, and percentage of filler to weight ratio of epoxy mixture is optimum at 20%. It was found that brass gave higher mean hardness values, (Hv = 24.1) compared to copper (Hv = 22.7) and aluminium filled epoxy (Hv = 22.3) based on the prediction run, and suitable as additional filler to improve the surface toughness of epoxy matrix as inserts. Confirmation run was conducted according to the optimum parameters and validated the gain values for brass at 7.98. Fillers enhance the mechanical properties of epoxy matrix by increasing hardness of mould cavity and core. This work helped to design the best control factors to produce optimum hardness conditions for filled epoxy matrix.
The Influence of Punch Angle on the Spring Back during V-Bending of Medium Carbon Steel
Authors: Suyuti Muhammad Arsyad , Nur Rusdi , Asmeati Asmeati
Published: October 2015

This study presents the influence of punch angle on the spring back behavior of the medium carbon steel under V-bending through experimental and analytical studies. Punch angle from 80o, 85o and 90o were applied to the samples, which were bent on a 90° V-shaped die for the spring back evaluation. Results from both the experimental and analytical method indicate that the spring back has similar results with the punch angle of 80o, 85o and 90o.
Interaction of Metal and Slag in Continuous Casting Mold
Authors: Arruda José Dimas , Pereira Alexandre Leopoldo , da Silva Carlos Antonio , da Silva Itavahn Alves , Seshadri Varadarajan
Published: October 2015

Knowledge of the flow field inside the mold can offer an opportunity to improve the internal cleanness of the final product. The PIV technique was employed to assess the distribution of longitudinal velocity distribution along a wide section ranging from the submerged nozzle entry to the narrow surface of a mold in a slab casting machine, as well as the distribution of transverse velocity component. This information can be used to assess the degree of interfacial turbulence and also to characterize transient phenomena in the mold.
Mathematical Modeling of Heat Losses in Steelmaking Ladles
Authors: Duarte Izabela Diniz , da Silva Carlos Antonio , da Silva Itavahn Alves , Ferreira Eliana Rodrigues , Seshadri Varadarajan
Published: October 2015

The main factors that determine heat losses in a steelmaking ladle are reviewed. Controlling the temperature of the liquid steel from the primary refining until casting is essential to achieve product quality as well as energy savings. Among other objectives this study sought to assess the relative weight of heat losses to the refractory lining and the thermal losses through the slag layer. Temperature, slag thickness and properties, refractory temperature and physical properties and convection characteristics are the defining factors. Numerical integration was carried out with a computer code specifically developed for the purpose .The results show that heat loss through the refractory linings at side wall is relatively high compared to that through the bottom and slag layer, Heat loss through the double slag layer depends on temperature, slag thickness, heat transfer coefficient and time.
Study of Heat Dissipation Generated in Tool Designed for Friction Stir Welding Process (FSW)
Authors: Paramo G. , Benitez A.
Published: October 2015

Friction stir welding (FSW) is an alternative method of joining materials with low melting point, patented in 1991 by the American Welding Institute (UK). This method uses the heat generated by mechanical friction between two moving parts, one is the tool rotates and is fastened on the spindle of a conventional milling machine and the other is the part that is attached and is gagged on the bed of the machine. Among the variables identified as the most important for a successful run of the process are the revolutions per minute (RPM) at which the tool rotates, the speed advance at which the workpiece and the tool design as such moves [1]. In this paper the design of several tools applied to FSW process is studied in specific dissipation of heat generated by mechanical friction between the parts, its relation to tool design and qualities of successful meetings is presented, the methodology to achieve this goal was first identify the possible and applicable materials for the tools, second his respective designs to ensure the right function for operation, and finally define FSW technical parameters (RPM, Head angle, speed advance) for experimental tests. The findings and conclusions attribute a novel analysis in the design of tools for this innovative manufacturing process, in the analysis of the results obtained for each of the assemblies experimentation it was discovered that the use of rings at the parts are not decisive for a good weld even heat dispersion is not good.
Development of Aluminum Anodizing Process by the Power Supply Using Pulse Width Rectifying Method
Authors: Chung Myung Jin
Published: October 2015

Pulse width rectifying method, adopted in the power supply using for anodizing process, is proposed. This method needs low requiring voltage and short processing time than previous anodizing method to make a same thickness of Al2O3 layer. The performance test is conducted with power supply using the pulse width rectifying method. The aluminum specimen having Al2O3 layer generated by proposed anodizing process is analyzed by using the SEM image. From the analysis of SEM image, the generation rate of Al2O3 layer is calculated as 1.25μm/min.
TGO Formation with NiCoCrAlYTa Bond Coat Deposition Using APS and HVOF Method
Authors: Mohd Zulkifli S. , Yajid Muhammad Azizi Mat , Idris Mohd Hasbullah , Daroonparvar M. , Hamdan Halimaton
Published: October 2015

Formation of thin and continuous layer of thermally grown oxide (TGO) in thermal barrier coating (TBC) are essential in order to avoid coating failure for high temperature applications. As-sprayed high velocity oxy-fuel (HVOF) bond coat can provide more uniform TGO layer in TBC system and much less oxide compare to air plasma spray (APS). In this paper, both APS and HVOF method are used to deposit NiCoCrAlYTa bond coat on Inconel 625 substrate followed by topcoat, YSZ deposition. Pre-oxidation process was done in normal oxygen furnace at 1000°C for 12 to 24 hours to study the characteristic of TGO formation via these two different methods. From the result obtained, it shows that HVOF method provide better TGO formation as compared to APS.
Thermal Response of Activated Charcoal Modified Investment Casting Moulds
Authors: Yahaya Bashir , Nazim E.M. , Idris Mohd Hasbullah , Dambatta M.S. , Anwar Mahmood , Izman Sudin
Published: October 2015

Direct microwave dewaxing of investment casting moulds is possible at the expense of time and poor heat distribution. Modifying the back-up stucco of investment casting moulds may enhance microwave absorption; however, it may affect its thermal properties. In this study, the effects of adding activated charcoal in the back-up stucco of the investment casting mould were investigated. Samples prepared without and with 25% activated charcoal were tested for differential scanning calorimetry (DSC) and Thermogravimetric analysis (TGA). It was observed that the specific heat capacity is higher in the samples added with activated charcoal. The DSC curves exhibit a smooth trend with no indication of exothermic or endothermic peaks in both samples. The glass transition temperature was also increased from 515.29°C to 582.24°C after modifying the contents. However, the TGA results show no significant difference in mass lost between the two samples that are about 2%. The DSC and TGA curves for both samples show similar patterns indicating that there is very close similarity in their thermal behaviour. Due to that, it can be concluded that the addition of activated charcoal in the back-up stucco does not induce an unusual reaction or thermal behaviour in the moulds.
A Study on Different Welding Processes of IN718 for Elevated Temperature Application
Authors: Min Kyung Ju , Yoon Jong Hoon , Yoo Joon Tae , Lee Ho Sung
Published: October 2015

Alloy IN718 is a nickel based precipitation hardened material and it has the necessary strength over a range of temperatures which includes the operating range for many rocket propulsion systems and jet engines. This performance is accomplished by a combination of solid-solution strengthening, precipitation strengthening and grain-boundary strengthening. However, it is common for precipitation hardened nickel based superalloys to have a problem of post-weld cracking. In this study, several welding processes are investigated to obtain the optimum welding method of IN718 for elevated temperature forming. These include LBW(Laser Beam Welding), EBW(Electron Beam Welding), HIP(hot isostatic pressing), and solid state diffusion bonding. The result shows that the LBW specimen performs the highest formability at 980°C so that this process can be applied to superplastic forming of IN718 sheet. It is demonstrated that the elevated temperature superplastic forming of nozzle extension with internal cooling channels was possible with laser beam welded IN718 sheet.
Mechanical Properties of Shielded Metal Arc Welded Low Carbon Steel: Effect of Butt Joint Type and Uncapping of Excess Weldment
Authors: Wardoyo Toto Triantoro Budi , Izman S. , Sharif Safian , Ardhyananta Hosta , Kurniawan Denni
Published: October 2015

In this paper, Shielded Metal Arc Welding (SMAW) was performed on low carbon steel with three types of butt joint (i.e., square, single V, and double V) and uncapping of the weldment. The welding performance is measured based on the mechanical properties (i.e., strength and hardness). Grain size and microstructure of the weldments were also evaluated. The results show that all tested samples show similar tensile strength, which means there was no significant effect of the type of butt joint type or uncapping. The hardness of the weld metal was found to be slightly higher than that of heat affected zone and base metal, in which both showed similar hardness values. The grain size of the weld metal was also finer than that of heat affected zone and base metal. This trend in hardness and grain size on three regions of the welded sample was the same regardless of the butt joint type and whether the weldment was uncapped or not.
Effects of Salinity on Nanosilica Applications in Altering Limestone Rock Wettability for Enhanced Oil Recovery
Authors: Sulaiman Wan Rosli Wan , Adala A.J. , Junin Radzuan , Ismail Issham , Ismail Abdul Razak , Hamid Mariani Abdul , Kamaruddin Mohd Johari , Zakaria Zaki Yamani , Johari Anwar , Hassim Mimi Haryani , Tuan Abdullah Tuan Amran , Kidam Kamarizan
Published: October 2015

The role of nanoparticles in enhancing oil recovery from oil reservoirs is an increasingly important topic of research. Nanoparticles have the properties that are potentially useful for enhanced oil recovery (EOR) processes. One of the important roles of nanoparticles in petroleum industry is to change the wettability of reservoir rocks. The main objective of this study is to investigate the efficiency of silica nanoparticles in enhancing oil recovery in the presence of formation brine with different concentrations. The methodology of this study involved several laboratory tests. It is divided into two main sections with the aim of enhance oil recovery of oil wet reservoirs. First, the wettability alteration and oil–water interfacial tension modification induced by introducing different concentrations of nanosilica (0.01, 0.05, 0.1wt %) and different concentrations of NaCl formation brine (0.3, 1, 2, 3, 4 wt %) was studied by experimental approach. Second, the displacement test for determining oil recovery for those different concentrations of nanosilica and formation brine. There exists an optimal nanoslica concentration for varying salinity and an optimal salinity for varying nanosilica concentration at which the wettability alteration on oil wet limestone is the maximum for the study. The results revealed that IFT and contact angle tests were found to have the same optimal salinity (0.3wt %) and optimal nanosilica concentration (0.1wt %). Furthermore the highest value of displacement efficiency obtained at nanosilica (0.05wt %) and salinity (0.3 wt %) NaCl. As conclusion, as the salinity increases the extent of wettability alteration, IFT reduction, and enhanced oil recovery by nanosilica decreases.
Improved Coefficient of Friction Using Different Types of Lubricants in Drilling Operation
Authors: Ismail Abdul Razak , Rashid Muhammad Syafiq Ab , Ismail Nurul Jannah , Sulaiman Wan Rosli Wan , Jaafar Mohd Zaidi
Published: October 2015

The key performance of any drilling operation depends heavily on the choice of drilling fluid used as well as how good it can overcome the drill pipe friction. It is essential that the drilling fluid be able to reduce bit wear, torque and drag. Drilling with oil-based drilling fluid offer less torque and drag. However, water based drilling fluid are cheaper and environmental friendly compared to oil-based and synthetic-based drilling fluids. Lubricants are added to drilling fluid to produce a thin film of liquid that separates the solid surfaces in contact to reduce the friction to an acceptable range. This study focused on the performance evaluation of two different commercial lubricants, which are EBL and EME salt to improve the lubricity of water based drilling fluid. The performances of lubricants were evaluated by ranging the concentrations from 1%, 2% and 3%. Fann Lubricity Tester is used to test the lubricity of these lubricants. The results reveal that the coefficients of friction for all lubricants were reduced after reaching the optimum concentration at the range of 1 - 2%. Some improvements were observed on the rheological properties such as plastic viscosity, yield point and gel strength when the lubricants were added to the drilling fluid. The values satisfy the requirement accepted by the industry. This study also showed that the applicants of EBL lubricant is better than EME salt in term of reducing the coefficient of friction in drilling fluid.
Mechanical and Thermal Properties of Rubber Toughened Poly(Lactic Acid)
Authors: Mad Desa Mohd Shaiful Zaidi , Hassan Azman , Arsad Agus , Mohammad Nor Nisa Balqis
Published: October 2015

The effect of rubber toughening on mechanical and thermal properties of poly (lactic acid) (PLA) was investigated by using three types of rubbers; natural rubber (NR), epoxidized natural rubber (ENR) and core-shell rubber (CSR). The PLA/rubber blends were prepared by melt blending in a counter-rotating twin-screw extruder, where the rubber content for all blends was kept at 5 wt%. It was found that the addition of the rubbers increased the impact strength for all blends as compared to pure PLA. On the other hand, all PLA/rubber blends showed notable decrease of Young’s modulus especially for PLA/NR blend which decreased by 72% than pure PLA. Similarly, significant decrease of tensile strength was also observed for all PLA/rubber blends. PLA/ENR blend showed a morebalance mechanical properties with fairly significant improvement of impact strength and moderate decrease of tensile strength, Young’s modulus and elongation at break. In general, PLA/NR blend showed the highest overall impact strength, while the PLA/CSR showed the highest tensile strength and Young’s modulus among the blends. Thermal analysis revealed that the Tg of PLA decreased with incorporation of the three types of rubbers with NR showing the largest decrease. This study indicates that NR, ENR and CSR are effective in enhancing toughness of PLA
Mechanical Behavior of Composite Multilayered Basalt/E-Glass/Epoxy Pipe under Internal Pressure
Authors: Almula Thamir Aunal Deen Mohammed Sheet , Yahya Mohd Yazid , Ayob Amran , Makhtar Iqbal , Alias Amran
Published: October 2015

Pressurized composite pipes made of concentric fiber reinforced polymer layers have found much interest among researchers. These composite pipes possess mechanical and thermal properties that exceed those of their constituent materials. This development is motivated by the demand for corrosion resistant, lighter and high specific stiffness components. Natural fiber composite materials retain better flexural stiffness and are environmentally friendly. Unlike experimental testing, numerical investigations on the manufacture and performance of natural fiber reinforced pipes under internal pressure seem lacking. In this analysis, the mechanical behavior of multilayer composite pipes made of natural basalt and E-glass fibers under internal pressure were carried out numerically. The multilayered composite pipes were fabricated by employing filament winding technique with, basalt and E-glass fibers, with fiber orientation angles of ±45o, ±55o, ±65o, ±75o. The matrix epoxy resin was infused using vacuum infusion process (VIP). A longitudinal and hoop tensile test rig, designed and fabricated according to ASTM D2105 and D2299 respectively, was used to determine the hoop and longitudinal properties of the pipes. Numerical simulations were conducted to determine the stress and strain behaviors with the intention to find the effect of ply angle, basalt and glass properties and also to evaluate the performance of the new natural basalt fiber as an alternative to E-glass/Epoxy.
Alteration by Cerium Element on Primary and Eutectic Mg2Si Phases in Al-20%Mg2Si In Situ Composite
Authors: Nordin Nur Azmah , Farahany Saeed , Abu Bakar Tuty Asma , Hamzah Esah
Published: October 2015

Owing to its beneficial material properties, Al-Mg2Si in-situ composite has recently received wide attention and application in the manufacture of automotive and aerospace components. Melt treatment of the in-situ composite with the addition of Ce has resulted in a change in the primary and eutectic Mg2Si phases to refined morphology, which would be expected to improve the mechanical properties of the composite. Characteristic parameters of Mg2Si particles have been investigated via thermal and microstructural analysis. This has revealed that the addition of 0.8wt.% Ce produced optimum refinement effects on Mg2SiP because the coarse structure has been changed to a polygonal shape and reduced in size. Similarly, the flake-like morphology of Mg2SiE has been transformed into a rod-like or fibre form in addition to reduction of the eutectic cell area. The result also showed an increase in nucleation temperature TN of Mg2SiP while depressed for Mg2SiE, which also corresponds to the refinement morphology effect.
Highly Response and Sensitive Copper Sensors Based on Chitosan Films
Authors: Eljali Ahmed , Nainggolan Irwana , Hashim Shahrir , Nasution Tulus Ikhsan
Published: October 2015

Discharge of metal containing effluents into water has been a major concern. Traditional detecting methods were proven to be ineffective and expensive. This paper proposes the use of chitosan film as a highly response and sensitive film sensor towards Cu ion due to its positive charge and electrical characteristic. Chitosan film was deposited by using electrochemical deposition technique. Different deposition times were applied to study the effect of deposition time on sensing properties of chitosan films, in which the best performance time of 90 seconds was recorded. This study was carried out to investigate the sensing performance of chitosan films toward variation concentrations of copper ion. Contaminated air exposure technique was used in this work to detect the concentrations of copper ion. The chitosan film sensors showed different sensor output toward deionized water and 0.005 M, 0.01M, 0.05M, 0.1M copper ions. The results showed that chitosan films had good sensitivity, fast response, stable and excellent recovery time. Scanning electron microscopy was employed to characterize chitosan film structure.
Overview on Mechanical-Chemical Ionic Liquid Pretreatment Study on Bioethanol–Based Lignocellulosics Biomass
Authors: Mohd Safaai Nor Sharliza , Azizan Amizon , Ramli Maisarah , Che Kamarludin Siti Norsyarahah
Published: October 2015

Due to rapid growth in population and industrialization, worldwide ethanol demand is increasing continuously. The abundant sources of lignocellulosic biomass (LB) from agricultural wastes are attractive feed stocks to become a sustainable source for bioethanol production. There are many crucial engineering steps involved in the bioethanol production route especially on the pretreatment which comprises of chemical, mechanical and biological approaches. In this study we reviewed the various pretreatment involved in biofuel production. By considering the all steps required which may incur costs then influence the price of bioethanol an effective pretreatment technology is required for minimizing the cost and concurrently minimizing other problem especially environmental pollution caused by the pretreatment process. Therefore, a compact step combining all or some of the steps and with additional application of green technology with ionic liquid (IL) will be beneficial to the future direct production of liquefied biofuel with chemical-mechanical-biological based techniques starting from the pretreatment study which therefore lessen cost incurred and process time.
Characterization of Nanosilica of Tapioca Peel as Adsorbent for Biomethane Storage System
Authors: binti Habibun Hasnizah , binti Abdul Manaf Shareena Fairuz , Alias Nur Hashimah , Ab Aziz Nur Shahidah , Hamzah Fazlena
Published: October 2015

Biomethane is an alternative and renewable source that occurred naturally which produced from the anaerobic digestion of organic matter. It can be used as the electricity power generation, water heating and also vehicle fuel. In this study, the characteristics of the nanosilica of the tapioca peel as an adsorbent on the structural and physical properties to store the biomethane were investigated. To enhance the adsorption and desorption performance as well as the structural and physical properties, the nanosilica was modified with the metal oxides. The metal oxides that have been used to modify the nanosilica adsorbent are zinc (II) oxide (ZnO) and nickel (II) oxide (NiO). Both of the modified and unmodified nanosilica structural properties were characterized by using X-Ray Diffraction (XRD) and Scanning Electron Microscope (SEM). While, the physical properties of both of the modified and unmodified nanosilica were characterized by using Brunauer, Emmet, Teller (BET) surface area measurement. The effects of both types of metal oxides with different concentration were investigated. Based on the results obtained, the structural and physical characteristics of the nanosilica were affected by the different metal oxides loading. It have been identified that 1% ZnO modified nanosilica has highest BET surface area (8.32 m2/g) with pore volume (19.23 cc/g) and pore size (82.8 nm). Thus, it concluded that 1% ZnO modified nanosilica improved the structural and physical structure. Hence, it enhances the capacity of methane adsorption and desorption prior to storage system.
Tensile and Morphological Properties of Hybrid Montmorillonite/Microcrystalline Cellulose Filled Polylactic Acid Composites: Effect of Filler Ratio
Authors: Arjmandi Reza , Hassan Azman , Mohamad Kassim Mohamad Haafiz , Zakaria Zainoha
Published: October 2015

The objective of this study is to investigate the effect of partial replacement of montmorillonite (MMT) with microcrystalline cellulose (MCC) on the tensile and morphology properties of polylactic acid (PLA) composites. PLA composites reinforced with hybrid MMT/MCC were prepared by solution casting. Based on our previous study, tensile strength exhibited that the optimum MMT content in the PLA/MMT is 5 phr. Therefore, partial replacement of MMT with MCC was performed at 5 phr of filler content in order to produce PLA/MMT/MCC hybrid composites. Fourier transform infrared spectroscopy revealed some polar interaction between fillers and PLA matrix. Young’s modulus of the PLA/MMT/MCC hybrid composites increased gradually with increasing MCC filler in the hybrid composites and was higher than PLA/MMT nanocomposites. However, the highest tensile strength of hybrid composites was obtained at 4 phr MMT and 1 phr of MCC filler (~26 MPa), which was lower than optimum formulation of PLA/MMT nanocomposites. Interestingly, the percent elongation at break of the hybrid composites were higher than that of PLA/MMT nanocomposites; increased significantly from ~10 to ~58 %. Field emission scanning electron microscopy indicated the aggregation of MCC and the presence of some cracks in the PLA hybrid composites, resulted in decrease of the tensile strength.
Effects of Pre-Treatment Conditions on Black Tilapia Fish Scales for Gelatin Extraction
Authors: SOCKALINGAM KANAGESWARY , Idris Maizlinda Izwana , Abdullah Hasan Zuhudi
Published: October 2015

Black tilapia (Oreochromis mossambicus) fish scales are good sources of gelatin. Fish scales needs to undergo adequate demineralization (pre-treatment) process in order to be a suitable medium for gelatin extraction. The effect of hydrochloric acid (HCl) concentrations (1-5 %) and pre-treatment time (4-20 h) on the raw tilapia scales have been determined. Scanning Electron Microscopy (SEM) analysis was done on the raw scales before and after pre-treatment process. SEM images reveal the pattern of ridges on the scales that fades away at different treatment conditions. Energy Dispersive X-ray Spectroscopy (EDX) results indicate that 3% of HCl with 12 h of treatment time is adequate for demineralization of the fish scales. These were further proved by Fourier Transform Infrared Spectroscopy (FTIR) analysis, where no any inorganic components been detected in the pre-treated scales in comparison to raw scales.
Oxidation of Pure Aluminium Granules during In Situ Melting
Authors: Saleh Aslinda , Idris Mohd Hasbullah
Published: October 2015

Oxidation behaviour of in-situ melted pure aluminium was investigated. The granules were heated in ceramic investment casting moulds between 700 and 850°C, for the duration of 30 and 60 min in air using high temperature muffle furnace. The product was visually inspected macroscopically for the geometry and appearance. Scanning electron microscope (SEM) together with energy dispersive x-ray spectroscopy (EDS) was employed to analyse the oxidation characteristics of the product. Macroscopically, the granules failed to melt and unable to produce a casting even when the temperature was increased to 850°C. The surface of the granule experienced oxidation and spalling. Both temperature and heating duration were found to influence geometry, appearance of the product and oxidation behaviour. The oxide layer encapsulated the granule during in-situ melting of Al granules was found to be Al2O3.
Biopolymeric Adsorbent for the Removal of Methylene Blue: Characterizations, Equilibrium Isotherms and Kinetic Studies
Authors: Muhmed Siti Aishah , Mohd Nawawi Mohd Ghazali
Published: October 2015

Crosslinked Sago Starch (CSS) was prepared by crosslinking native starch with Sodium Trimetaphosphate. As a biodegradable adsorbent, CSS was used to remove methylene blue (MB) from the aqueous solution based on its characterization, including the granule morphology, crystalline nature and molecular structure. The adsorption capacity of CSS was evaluated as a function of pH, adsorbent dosage, initial concentration and time. It was favorable for adsorption under condition of neutral and at high initial concentration. The adsorption capacity trend was decreased with increasing the adsorbent dosage. The equilibrium isotherms were conducted using Langmuir, Freundlich and Tempkin model. It has been demonstrated that the better agreement was Langmuir isotherm with correlation coefficient of 0.99, equilibrium adsorption capacity of 3.75 mg g-1, chi-square test, χ2 of 0.03% and corresponding contact time of 4 hours. The pseudo-first-order, pseudo-second-order and intra-particle diffusion were used to fit adsorption data in the kinetic studies. And results showed that the adsorption kinetics was more accurately described by the pseudo-second-order model with correlation coefficient, R2 of 0.99 and standard deviation, SSE of 0.12%. The obtained results suggest that CSS could be promising candidates as an adsorbent for dye removal.
Effect of Solvent on Adhesion Property of Glass Fiber Recycled by Superheated Steam
Authors: Shi Jian , Bao Li Min , Kemmochi Kiyoshi
Published: October 2015

We developed a kind of technology to recycle FRP by superheated steam. In order to achieve the good adhesion between unsaturated polyester resin and recycled glass fiber on which there were some char impurities, a surface treatment should be carried out to remove them. After surface cleaning, the recycled glass fibers were remanufactured to glass fiber reinforced polymer (GFRP) for adhesion test. It was carried out to evaluate the effects of solution and soaking time. Samples of treated, recycled and virgin fibers were analyzed by scanning electron microscopy to determine visual signs of residual char impurities. SEM picture showed char impurities would decrease after surface cleaning by ultrasonic cleaning machine. Although detergent can make work life more environmental friendly, SEM micrographs indicated that there were less residual char impurities on glass fiber which cleaned by acetone. Results of adhesion test showed that adhesion property of remanufactured GFRP can be preserved about 90% of that of virgin GFRP. The recycled glass fibers were able to be used as feedstock for remanufactured GFRP with high mechanical properties.
An Introduction to Lightweight, Energy Saving, Environment Friendly Magnesium Based Nanocomposites: Materials of Upcoming Generation
Authors: Gupta Manoj , Wong W.L.E.
Published: October 2015

Magnesium nanocomposites are promising materials for weight and strength critical engineering and biomedical applications. The addition of nano-particles to magnesium can improve hardness and strength without detrimental effect on the ductility which tends to occur when micron-size particles are added. Examples of magnesium nanocomposites reinforced with ceramic and metallic particles are provided and the microstructure, grain size, tensile, compressive and dynamic behavior are discussed.
Determination of Volatile Organic Compounds (VOCs) at Selected Pump Stations in Skudai, Johor Bahru
Authors: Hassim Mimi H. , Mohammad Norsyazwani , Johari Anwar , Tuan Abdullah Tuan Amran , Kidam Kamarizan , Kamaruddin Mohd Johari , Zakaria Zaki Yamani , Sulaiman Wan Rosli Wan
Published: October 2015

The determination of volatile organic compounds (VOCs) at selected pump stations in Skudai, Johor Bahru was investigated. About 27 chemicals substances in petrol and 24 chemicals substances in diesel with different concentration have been identified in each pump station. Benzene, toluene, ethylbenzene and xylene (BTEX) and MTBE have been chosen as VOCs of interests because of their toxicity properties that can gives hazardous to human health. The exposures of benzene at all three pump stations during refuelling the liquid fuel have potential to cause cancer riskwhile, ethylbenzene stated as acceptable risk to the people health.As for non-carcinogenic substances, the exposure of toluene, xylene and MTBE were recorded as acceptable risk to the people health at all the studied pump stations. Besides, there is a great correlation between physical environment factors; temperature, relative humidity and wind speed typically with total volatile organic compounds that evaporate into the ambient air during refuelling activities.
Carbon Dioxide Removal by Using Absorption Process with 5M Aqueous Solution of 2-(Methylamino)Ethanol
Authors: Maneeintr Kreangkrai , Iamareerat Pimon , Manonukul Poomsup , Assabumrungrat Suttichai , Charinpanitkul Tawatchai
Published: October 2015

For petroleum industries, CO2 can cause corrosion, and heating-value reduction. However, CO2 can be used to enhance the oil recovery for oil production. However, the amount of CO2 supply is not enough because the cost of carbon capture is high. The main sources of CO2 come from power generation. The technology to capture CO2 is carbon capture and storage or CCS. Currently, the effective technology to remove CO2 from the power plants is chemical absorption and chemicals used in this technology play a key role. Nowadays, the commercially used solvents are monoethanolamine (MEA). Nevertheless, it also has disadvantages such as low capacity and high energy requirement for regeneration thus making CCS costly. Therefore, many new solvents such as 2-(methylamino) ethanol or 2-MAE have been developed to improve efficiency and to reduce the cost of CO2 capture. Therefore, the objective of this work is to measure the solubility data of CO2 in a 5M aqueous solution of 2-MAE as a promising solvent at the temperature from 30 °C to 80 °C and CO2 partial pressures ranging from 5 to 100 kPa. The solubility results of CO2 in 2-MAE solution are compared with those of aqueous solution of MEA. In term of cyclic capacities, the results show that 2-MAE provides higher performance which is up to 86.8% and 150.9% higher than that of MEA at 15 and 100 kPa, respectively. Furthermore, the results present that the CO2 loading can increase as partial pressure increases and decrease at higher temperature. It can be concluded that an increase in cyclic capacity leads to the decrease in energy requirement for solution regeneration and liquid-circulation rate, leading to the reduction of the overall capital and operating costs and resulting in the decrease in cost of carbon capture.
Particulate Emission from Biomass Fuel Combustion
Authors: Nor Ruwaida J. , Rashid M. , Syahirah M.M.
Published: October 2015

The remarkable growth of palm oil industry in Malaysia is undeniable. Approximately, one million ton of crude palm oil is produced by the industry in a month, thus put Malaysia as one of the largest producer in the world. Most of the mills are operated on cogeneration system, where the biomass residue of palm fibre and shell are used as fuel in the mill boilers mostly to generate steam and also electricity. This practise however produced considerable amount of particulates in terms of fly ash emitting to the environment. Thus, this study is to evaluate the particulate emission from five palm oil mill boilers with steam capacity ranging from 17-35 tonne/h. The results showed that the average particulate emission concentration exiting the stack was 2.21±1.20 g/Nm3 (corrected to 7% oxygen concentration), ranging from 0.42 to 3.77 g/Nm3. The study suggests that the fuel feed rates of fiber and shell was one of the parameters affecting the emission concentration in the boiler. Particulate morphology were also being presented in this study.
An Investigation of Carbon Dioxide Sequestration on Amine–Modified Kenaf: Adsorption Isotherm Study
Authors: Zaini Nabilah , Kamarudin K.S.N.
Published: October 2015

The increase concentration of CO2 in the atmosphere is linked with global climate change. Among the technology options used for CO2 capture, there is a growing interest in using adsorption method for separation process. Inspired by the most applicable technology of amine–based chemical absorption for capturing CO2, the development of amine–functionalized kenaf based adsorbent has been proposed in this study. The incorporation of amine functional group (MEA and TEPA) on kenaf was conducted via wet impregnation method. The characterization was carried out by using FESEM and FTIR. The CO2 adsorption equilibrium study have been conducted and further described by Langmuir and Freundlich isotherm equation models at temperature of 0, 25 and 50oC. Result presented shows that Freundlich isotherm model fits the experimental data for raw kenaf and amine–modified kenaf. It was indicated by the values of R2. Additionally, results for each sample show the adsorption favourability since the values of KL is less than 1 and the magnitude of Freundlich (n) is greater than 1. Finally, this study revealed that the amine–modified kenaf could become another potential adsorbent for CO2 separation.
Effect of Silver Nanoparticles in Silicalite-1 Zeolite on Antireflection and Antibacterial Performances
Authors: Bae Hye Jin , Lee Bo Kyung , Ok Hae Ryul , Choi Byung Ho
Published: October 2015

A nano-sized zeolite has been prepared in an autoclave, using tetraethoxysilane (TEOS), tetrapropylammonium hydroxide (TPAOH) and H2O at various hydrothermal synthesis temperatures. Using transmission electron microscopy and particle size analysis, the size of the nano-sized powders was revealed to be 10–300 nm and its distribution was uniform and spherical, depending on the hydrothermal temperature. X-ray diffraction analysis confirmed that the nano-sized powder was the silicalite-1 zeolite. A coating sol could be prepared by the proper combination of these nanoparticles with a solvent. The resulting coating on the glass substrate showed an antireflection effect, with less than 2–3% average reflectance over the visible range. In addition, the effect of silver nanoparticles in the silicalite-1 zeolite on antibacterial performances was carried as a function of the amount of nano-sized silver used. With increasing amounts of nano-sized silver, the number of colony forming unit decreased and became almost to zero.