bluuebunny/crossref_metadata_2025 huggingface dataset:
Comparative Study and Analysis of Friction Stir Welding with Plasma ARC Welding
Authors: Elanchezhian C. , Vijaya Ramnath B. , Pazhanivel Kaliyaperumal , Vedhapuri A. , Mano B. , Manojkumar A. , Stalin M. , Vishnu V.
Published: June 2015

The main objective of this work is to compare the friction stir welding with plasma arc welding processes using dissimilar materials. The materials used AA 8011 and AA 6061.The factors compared in this process are the weld quality, different welding feed and rotation speed. The effects of welding processes on the impact test and micro hardness behaviour were studied. Morphological analysis was carried out using SEM analysis. Taguchi’s, DOE method and ANOVA is done to find the parameters that have highest influence on weld strength. The results show that the FSW joints exhibit superior tensile and fatigue, impact test, and micro hardness properties compared to plasma arc welding. This is mainly due to the presence of mechanical properties are superior to plasma arc welding. Keywords: Friction stir welding, SEM, AA 8011, AA 6061, plasma arc welding, ANOVA, and DOE
Heat Reduction in a Tool Holder during Friction Stir Welding of Aluminium Alloy
Authors: Mystica A. , Sankavi S.P. , Siva Sakthi V. , Ganesh T.S. , Senthil Kumar V.S.
Published: June 2015

Friction stir welding is a solid state welding process that uses a rotating tool to amalgamate two metals by the frictional heat generated. Recent developments in FSW of aluminium have been exploited in aerospace, marine and transport industries. The friction stir welding on aluminium metal generates heat which has detrimental effects on the system in the long run. The heat generated, due to the friction developed, has to be reduced to provide a constant thermal environment for the tool and the workpiece. This work focuses on the conception to develop a water cooled tool holder to reduce the excess temperature thereby protecting the spindle bearing. The current paper elucidates on the design and parameters of water cooled tool holder and spring loaded seal, its implementation and the results obtained by friction stir welding of aluminum.
Investigating the Weld Strength of AA7075 Aluminium Alloy for TIG, MIG and FSW Welding
Authors: Elanchezhian C. , Vijaya Ramnath B. , Saisundararam R. , Ramanan V. , Siddarth C.S. , Kandeepa Thondaiman P. , Maurya Sundar V. , Mohammed Sadiq S.
Published: June 2015

The main objective of this work is to compare the weld strength of AA7075 aluminium alloy by conducting tensile test and impact test for various welding like TIG, MIG and FSW. Aluminium is one of the lightest available commercial metals with a density approximately one third that of steel or copper, thus making it the most earnestly used metal for Catamaran ferries, petroleum tankers and aircrafts. Having so many welding methods for joining AA7075 alloy, it is still unclear as to which welding method gives the better weld strength. This study shows the best suitable method of welding for AA7075 aluminium alloy for the suitable conditions specified. ANOVA is done to find the parameters that have highest influence on weld strength. The result shows that the parameter that has highest influence on weld strength is axial force.
Influence of Process Parameter on Microstructural Characteristics and Tensile Properties of Friction Welded ASS304L Alloy
Authors: Umanath K. , Palanikumar K.
Published: June 2015

The rotary type continuous friction welding process is a solid state joining process by mechanically. It produces a joint in the forging pressure contact with rotating and motionless workpiece. The solid state joining process it produces welds with reduced distortion and improved mechanical properties. The austenitic stainless steels are widely used in shipbuilding field, nuclear field and automobile field because of their special mechanical and metallurgical properties. In this work, friction welding of austenitic stainless steel rods of 10mm diameter was investigated with an aim to understand the influence of friction welding process parameters. The details of microstructure analysis using optical microscopy are discussed.
Developing the Empirical Relationship to Predict the Minimum Microhardness of AISI 1020 Grade Low Carbon Steel Joints
Authors: Selvamani S.T. , Umanath K. , Palanikumar K. , Vinothkumar P. , Madhu G.
Published: June 2015

In this research work, friction welding (FW) of AISI 1020 grade carbon steel rods of 12 mm diameter was investigated with an aim to develop the empirical relationship to predict the minimum micro hardness for the process parameters. Welds are made with various process parameter combinations using ANOVA design matrix which were subjected to Vickers hardness tests. A microstructure analyses was carried out to acquire the joint efficiency. The heat affected zone of the microstructure has been shown for the optimized condition.Keywords:-Friction welding, AISI 1020 grade carbon steel, empirical relationship, Grain structure, Micro hardness.
Characterization of Duplex Stainless Steel/Cold Reduced Low Carbon Steel Dissimilar Weld Joints by GTAW
Authors: Devakumar D. , Jabaraj D.B. , Bupesh Raja V.K. , P Periyasamy
Published: June 2015

The purpose of this study is to evaluate the mechanical and metallurgical properties of dissimilar metal weld joints between duplex stainless steel/Cold Reduced low carbon Steel (CRS) by Gas Tungsten Arc Welding (GTAW) process. The dissimilar 2 mm thickness plates of duplex stainless steel and cold reduced low carbon steel, conforming to AISI 2205 and IS 513_2008 CR2_D were butt welded by means of gas tungsten arc welding using argon as shielding gas. The butt welding joint arrangement was used for this experiment using E 309L electrode as filler metal. The joints were investigated for mechanical properties and microstructure. Tensile, Hardness and bend tests were carried out to evaluate the mechanical properties. Optical microscopy was used to explore the microstructure. The micro structural examination of the weld region revealed dendritic delta ferrite. Micro examination of DSS base metal revealed elongated grains of austenite (white) with ferrite (Brown). Micro examination of CRS base metal discloses deformed grains of ferrite present in the matrix. Fracture analysis was conducted for the failure part with Scanning Electron Microscope (SEM) and found ductile fracture occurred at CR steel side.
Delamination in Drilling of Natural Fibre Reinforced Polymer Composites Produced by Compression Moulding
Authors: Aravindh S. , Umanath K.
Published: June 2015

Natural fibre composites today are replacing synthetic fibre composites due to superior properties of natural fibres such as low density, high specific strength and modulus, relative no abrasiveness, ease of fibre surface modification, and wide availability .Drilling is often required to facilitate the assembly of the parts to get the final product. however, drilling composite materials present a number of problems such as delamination associated with the characteristics of the material and with the used cutting parameters .The present investigation is an attempt to study the factors and combination of factors that influence the delamination of drilled unidirectional jute fibre reinforced composites using taguchi, signal to noise ratio, Anova analysis and to achieve the conditions for minimum delamination.
Optimization of Friction Welding in Dissimilar Materials through Taguchi Based Grey Relational Analysis
Authors: Shanjeevi C. , Satish Kumar S. , Sathiya P. , Jose Paul
Published: June 2015

Friction welding is widely used in determining the mass production process for joining dissimilar materials due to its environment friendliness, production efficiency and low heat input. In this study, Taguchi approach was applied in grey relational analysis to solve the multi-response optimization. The experimental result analysis is to achieve the maximization of tensile strength and minimization of weld time and metal loss. The optimal combinations of welding parameters are predicted through grey relational analysis for the multi-performance and optimal results were verified through confirmation test.
Minimizing of Rejection in Cylinder Head Machining Using the Anova Method
Authors: Shanmugam C. Jothi
Published: June 2015

The main rejections in the machining sections are exhaust valve port leak, injector bore blow hole, induction passage punchered, inlet valve port leak, top face unwash, valve guide hole blow hole, top face leak, joint face unwash, induction face unwash, rear face unwash, valve port unwash, water mixing with oil., water passage blocked, emf leak, injector bore leak, inlet valve port blocked, water way leak, oil way leak and defective jig location pad. This paper describes the method by which the rejections while maching the cylinder head, is minimized.
Modeling and Analysis of Cutting Force in Turning of AISI 316L Stainless Steel (SS) under Nano Cutting Environment
Authors: Rajmohan T. , Sathishkumar S.D. , Palanikumar K. , Ranganathan S.
Published: June 2015

Nano Cutting fluids play a significant role in machining operations and impact shop productivity, tool life and quality of work. In the present work, machining performance of AISI 316L Stainless steel (SS) is assessed under nano cutting environment. Experiments are performed by plain turning of 80mm diameter and 300mm long rod of AISI 316L SS on NAGMAT centre lathe under wet machining with and without Multi Wall Carbon nano Tubes (MWCNT) inclusions in the conventional lubricant. The Second order quadratic models were developed to predict cutting forces using response surface methodology (RSM) based D-optimal design. Machining parameters such as speed, feed rate and depth of cut are chosen as numerical factor, and the wt % of MWCNT content is considered as the categorical factor. Furthermore, using analysis of variance method, significant contributions of process parameters have been determined. Experimental results reveal that wt % of MWCNT and feed rate are the dominant variables on responses.
Investigation of Tensile Properties of Manila Fibre Reinforced Composite
Authors: Vijaya Ramnath B. , Manickavasagam V.M. , Elanchezhian C. , Rajendra Prasad A. , Kavin C. , Karthik Subramanian B. , Rahul V.
Published: June 2015

In the present scenario, composites are beginning to play a major role in day to day applications. Suitable properties can be imparted by selection or orientation of fibers during the manufacturing process. This paper demonstrates the natural composites made up of Manila as reinforcing agent with epoxy resin as matrix enclosed between glass fibers. Glass fibers, also known as woven rovings, are used to improve the surface finish and provide better strength and rigidity to the composite. Using hand lay-up method, fibers of Manila are arranged in alternate layers. The strength of composites depends on the fiber-matrix interfacial bonding. Three composite samples are prepared and mechanical stability of the composite is determined by tensile test. It is seen that there is not much variation in the ultimate strength of the three samples. On an average, it is found that average break load of the composite is 4.8 KN and the corresponding displacement is 9.08 mm. All the three samples exhibit almost similar elongation of about 18 % and the average ultimate tensile strength is 31.66 MPa. The reason for uniform tensile properties is due to a homogeneous distribution of fibers in all the three samples.
Theoretical Prediction of Thickness Distribution on Warm Deep Drawn AISI 304 Steel Cup
Authors: Ethiraj N. , Ganesh P. , Senthil Kumar V.S.
Published: June 2015

Warm deep drawing is a non-conventional deep drawing process which is performed by applying heat in the conventional deep drawing, at the same time keeping the blank below the recrystallization temperature. Austenitic stainless steels like AISI 304 are widely used in food and automotive industries. Most of the current research work in warm deep drawing has been focussing on experimental and numerical simulation only. In this work, a new methodology is proposed to calculate the thickness distribution of the warm deep drawn circular cup from AISI 304 stainless steel sheet of 1.0 mm thickness analytically at temperatures ranging from room temperature to 300°C. The results of the theoretical approach show a reasonably good correlation with the experimental results.
Effect of Vulcanization Additive on Cure Characteristics and Physical Properties of Silica Filled Epoxidised Natural Rubber Truck Tyre Tread Compound
Authors: Che Aziz Ahmad Kifli , Zaeimoedin Teku Zakwan , Mustafa Kamal Mazlina
Published: June 2015

The challenges of using Epoxidised Natural Rubber (ENR) in truck tyre tread are to achieve good cure reversion resistant and physical properties especially on abrasion resistance towards long vulcanization time. The objectives of the project are to study the effects of vulcanization additive on cure characteristics and physical properties of silica filled ENR compound. In this work, a variation of curing systems were employed and a standard carbon black filled Natural Rubber/Butadiene Rubber (NR/BR) compound as a comparison. Greater reversion resistance and physical properties were observed with inclusion of vulcanization additive in the silica compound as compared to compound containing any. The abrasion resistance on the hand improved in spite of long vulcanisation time which commonly practices in truck tyre manufacturing. Keywords: ENR, silica, vulcanization additive, cure reversion, abrasion resistance
Tensile Properties and Melt Flow Index of Polypropylene/Ethylene Propylene Diene Monomer Nanocomposites
Authors: Hamzah Muhammad Safwan , Mariatti M. , Kamarol M.
Published: June 2015

In this article, we report three nanofillers filled polymer composite systems. Nanofillers composed of alumina, titania and organoclay were embedded separately in 50% polypropylene (PP) and 50% ethylene propylene diene monomer (EPDM) blends. The nanocomposites were prepared using an internal mixer and were molded using a compression mold to form test samples. Effect of filler loading (2, 4, 6, and 8 vol.%) on the tensile properties and melt flow index (MFI) were determined. The mechanical properties of alumina are the highest compared to titania and organoclay. Alumina and organoclay shows an ascending trend in tensile strength with the increase of nanofiller loading. In contrast, the increment of titania filler loading reduces the tensile strength of the nanocomposites. The Young's modulus of the nanocomposites increases with the addition of filler loading. Elongation at break of the nanocomposites shows a descending trend with the addition of filler loading. The addition of 8 vol. % titania and organoclay slightly changes the MFI of the PP/EPDM nanocomposites whereas the addition of 8 vol. % alumina drastically decreased the MFI values. Further addition of nanofillers up to 8 vol. % decreases the MFI values of the PP/EPDM nanocomposites.
The Effects of Halogen-Free Flame Retardant Additives in Epoxidized Natural Rubber (ENR)
Authors: Habibah A.I.H.Dayang , Ruhida Abd Rahim
Published: June 2015

Legislation on fire safety requirements especially in the USA and UK has been the driving force behind the use of halogen-free flame retardants (FR) in recent years. The present study describes the effect of inorganic fillers, namely aluminium hydroxides (ATH) on epoxidized natural rubber (ENR) in order to increase its flame retardant capability. Two different types of ATH, a standard type Apyral 60 CD (ATH 60) and a submicron sized Apyral 200 SM (ATH 200) were used. The flame-retardant ENR composite was characterized by limiting oxygen index (LOI), UL-94V, and thermogravimetric analysis (TGA) to study the combustion behavior and thermal stability. The finer particles size (ATH 200) as expected produced better flame retardant properties (measured by LOI) compared to ATH 60; however, the difference between the values is marginal. It was also observed that a combination of 100 pphr ATH 200 and 60 pphr ATH 60 gave the highest LOI value (29.4%) in ENR compounds. The compound was V0 rated in UL-94V burn test. Even at the higher loading, it was also found that the compound exhibited lower viscosity indicating its easier processability.
Anions Effect on the Electrical Properties of PMMA/ENR 50 Blend Electrolytes
Authors: Latif Famiza , Sharil Fadli Mohamad Zamri , Aziz Madzlan
Published: June 2015

The lattice energy of the doping salt for a polymer electrolyte is crucial because it affects the ionic conductivity of the polymer electrolyte system. It is also known that the lattice energy of a salt depends on the size of the anion. The larger the anion the lower the lattice energy of the salt. Therefore, in this study the effect of the anion size of various doping salts; LiNO3 and LiN(CF3SO2)2 with lattice energy of 848 kJ/mol and 489.4 kJ/mol, respectively were investigated and compared with LiCF3SO3 salt (735 kJ/mol) on the electrical properties of poly (methyl methacrylate) (PMMA) / epoxidised natural rubber (ENR 50) blend film. All the doped PMMA/ENR 50 films were prepared by solvent casting technique. Surprisingly, though LiN(CF3SO2)2 exhibited the lowest lattice energy, it displayed the lowest ionic conductivity value of 10-8 S/cm at room temperature as compared to LiNO3 and LiBF4 due to its poor coordinating power with the polymer. This was confirmed from the FTIR analyses. Further investigation on the dielectric behaviour of the doped PMMA/ENR 50 films were also reported.
Conductivity and Thermal Behaviour of Epoxidized-30% Poly (Methyl Methacrylate)-Grafted Natural Rubber-Lithium Triflate Based Solid Polymer Electrolytes
Authors: Nazir Khuzaimah , Ayub Siti Fadzilah , Fairoz Aziz Ahmad , Zakaria Rosnah , Yahya Mohamad Faizul , Marwan Bin Ali Abdul Malik
Published: June 2015

Thin films of epoxidized-30% poly (methyl methacrylate)-grafted natural rubber (EMG30) doped with lithium triflate (LiTf) salt were prepared by using the solution-casting technique. Transformation of carbon double bond (C=C) into epoxide group (C-O-C) in EMG30 polymer host was confirmed by 1HNMR analysis. The ionic conductivity measurement was carried out and the highest conductivity was found to be at 5.843×10-3 S cm room temperature for the sample with composition at 60wt% EMG30: 40wt% LiTf. Thermal gravimetric analysis studies showed that upon the addition of lithium salts into EMG30 was increased the thermal stability of the polymer electrolyte systems.
Conductivity-Temperature Dependent Studies on MG49 Doped Lithium Triflate Salt
Authors: Mahmud Zaidatul Salwa , Zaki N.H.M. , Zakaria R. , Yahya Mohamad Faizul , Marwan Bin Ali Abdul Malik
Published: June 2015

This paper reports on the conductivity-temperature studies of gel polymer electrolytes (GPEs) based on 49% poly (methyl methacrylate) grafted-natural rubber (MG49) doped with lithium triflate salt (LiTf) and plasticized with ethylene carbonate (EC). The GPE films are prepared by solution cast technique. The X-ray diffraction (XRD) studies reveal the polymer electrolyte systems are amorphous. AC impedance spectroscopy is carried out in the temperature range between 303 and 373 K. The magnitudes of conductivity observed are strongly dependent on salt concentration and temperature. The high ionic conductivity at elevated temperatures of GPE is attributed to the high ionic mobility of charge carriers. The ionic migration is seen to follow the VTF behavior and approaches to Arrhenius rule at high and low at temperature. Ionic conductivity relaxation appears to be a characteristic of the ionic polarization and the modulus formalism studies confirmed the GPEs in the present investigation are ionic conductors.
Effect of Co3O4 Doping on Nonlinear Coefficient in Zn-Bi-Ti-O Varistor Ceramics
Authors: Ghazali Mohd Sabri Mohd , Zakaria Azmi , Abdullah Wan Rafizah Wan , Hafiz Mohd Zaid Mohd , Amin Matori Khamirul
Published: June 2015

In the ZnO based varistor, the improvement of nonlinear coefficient (α) and prevention of evaporation of Bi2O3 during heat treatments can be achieved by the addition of MnO2 or Co3O4. In this conjunction, it is proper to see the effect of these additives at different low mol percentage and sintering conditions to nonlinear coefficient improvement of the varistor ceramics. In this paper, the investigation regarding to the α variation of Co3O4 doping on ZnO-Bi2O3-TiO2 system is discussed. Here, the crystalline phases were identified by an XRD (PANalytical (Philips) XPert Pro PW3040/60) with CuKα radiation and the data were analyzed by using XPert High Score software. The density of varistor ceramics was measured by the geometrical method. The current-voltage characteristics of the varistor ceramics were evaluated. The average grain size (d) was determined by lineal intercept method. The α of ZnO doped with 0.5 mol% of Bi2O3, 0.5 mol% of TiO2 and x mol% of Co3O4 was calculated from data analysis of current-voltage characteristics obtained through a Source Measure Unit (Keithley 236). The calculation of α is done by using Origin Pro8.0 software. The value of α at low concentration at 1170 °C has the value 5.36 and 3 at 45 and 90 min sintering time, respectively, and then decreases to 4.99 and 2.98 at 0.8 mol% Co3O4 concentrations. When the amount of dopant is increased then the value of α increase up to 0.4 mol% and then the value are slightly dropped after further addition. The addition of Co3O4 dopant in Zn-Bi-Ti oxide ceramics sintered at 45 minutes cause the value of α to increase up to 0.4 mol% and decrease after further addition.
The Effect of HCl Concentration on the Ionic Conductivity of Liquid PMMA Oligomer
Authors: Kamaluddin Norashima , Famiza Abdul Latiff , Han Chan Chin
Published: June 2015

To date gel and film type polymer electrolytes have been widely synthesized due to their wide range of electrical properties. However, these types of polymer electrolytes exhibit poor mechanical stability and poor electrode-electrolyte contact hence deprive the overall performance of a battery system. Therefore, in order to indulge the advantages of polymer as electrolyte, a new class of liquid-type polymer electrolyte was synthesized and investigated. To date this type of polymer electrolytre has not been extensively studied. This is due to the unavailability of liquid polymer for significance application. In this study, liquid poly (methyl methacrylate) (PMMA) electrolyte was synthesized using the simplest free radical polymerization technique using benzoyl peroxide as the initiator. It was found that this liquid PMMA oligomer has potential as electrolyte in proton battery when doped with small volume of various molarity of hydrochloric acid (HCl) in which the highest ionic conductivity achieved was 10-7 S/cm at room temperature. The properties of this liquid PMMA oligomer were further investigated using Fourier Transform Infrared Spectroscopy (FTIR).
Electrochemical Behavior of Carbon Steel in Acidic Medium Containing Cationic Inhibitor
Authors: Nazri Idris Mohd , Daud Abdul Razak , Othman Norinsan Kamil
Published: June 2015

Electrochemical behavior of carbon steel in 1 M acetic acid (CH3COOH) containing tetramethyl ammonium bromide (TMB) as the cationic inhibitor was investigated by potentiodynamic polarization technique and electrochemical impedance spectroscopy (EIS). The aim of this study is to evaluate the inhibition efficiency of cationic inhibitor for carbon steel corrosion. The electrochemical analysis revealed that inhibition efficiency significantly increased with the increasing of inhibitor concentration. Polarization study indicated that TMB acted as a mixed type inhibitor, which inhibited both cathodic and anodic reactions. The changes of impedance parameters by different inhibitor concentration showed a better protection due to formation of a thin film onto the steel surface. This study suggests that TMB is able to inhibit corrosion process of carbon steel in acidic medium with significant inhibition efficiency.
Structural Study of Plasticized Carboxy Methylcellulose Based Solid Biopolymer Electrolyte
Authors: Chai M.N. , Isa M.I.N.
Published: June 2015

Carboxyl methylcellulose (CMC) doped with oleic acid (OA) and plasticized with glycerol was able to be produced into solid biopolymer electrolytes using the solution cast technique. The CMC-OA-glycerol solid polymer electrolyte obtained the highest conductivity of 1.64 x 10-4 S cm-1 at room temperature for sample Gly 40 wt. %. Within the temperature range investigated, the conductivity– temperature relationship of the biopolymer electrolytes is characteristically Arrhenius behaviour, suggesting that the conductivity is thermally assisted. Fourier Transform Infrared studies was carried out to determine the dissociation of free protons (H+) from the carboxyl group (–COOH) of glycerol.
Influence of Grain Formation on Electrical Properties of La0.67Sr0.33MnO3
Authors: Chin Hui Wei , Lim Kean Pah , Halim S.A. , Chen S.K. , Ng S.W. , Gan Albert  H.M. , Cheong K.H.
Published: June 2015

In this work, polycrystalline perovskite manganites of La0.67Sr0.33MnO3 (LSMO) sample was prepared by two wet chemical methods: co-precipitation (CP) and sol-gel (SG) methods. Both samples were sintered at high temperature (1300 °C) for longer duration (24 hours) to investigate the effect of grains formation on its electrical properties. XRD results show that both samples were forming single LSMO phase with hexagonal structure (R-3c). SG sample shows smaller grain size (~220nm) however the CP sample (~4.45μm) was about 20-fold larger. Slower grain growth takes place in SG sample due to the triple junction effect where grain growth in nanocrystal is limited. Terrace patterns are noticed on the surface of CP sample which is suspected as the occurrence full crystallization or recrystallisation. TP of SG sample was shifted to lower temperature (298 K) due to the significant magnetically disordered layer across the grain boundaries which had weakened double exchange effect. SG sample displays higher extrinsic MR (-10.8%, 1 kG) and intrinsic MR (-25.1%, 10 kG) at 80 K due to the Core-Shell effect in the nanograin. However, grain boundaries (shell) effect is weakening in full crystallite CP sample. Hence, only intrinsic MR can be observed which is-15.6% at 10 kG applied field. Consequently, extrinsic MR is dominant in sol-gel sample however intrinsic MR is dominant in co-precipitation sample. Therefore, the grain size and microstructure formation affect the Tp, resistivity and magnetoresistive effect.
Physico-Chemical Properties of Silica Coated Superparamagnetic Magnetite Nanoparticles Synthesized by Non-Seeded Process
Authors: Kayode Sodipo Bashiru , Aziz Azlan Abdul
Published: June 2015

The science of core-shell nanoparticles requires investigation into several physical and chemical properties of the composite nanoparticles. Unlike the conventional sol-gel or the reverse microemulsion micelle method, we presented here a non-seeded process of encapsulating superparamagnetic magnetite nanoparticles (SPMN) with silica. Physico-chemical analysis of the product was used to confirm the result of the coating procedure. Colloidal suspension of SPMN and silica nanoparticles were synthesised through coprecipitation method and modified Stöber method respectively. Afterwards, both colloidal suspensions of SPMN and silica nanoparticles were sonicated to encapsulate the SPMN with silica. Elemental mapping of the composite particles with electron spectroscopy imaging (ESI) confirmed the core-shell micrograph of the SPMN and silica. The X-ray diffraction pattern (XRD) showed the silica shell to be in amorphous form. FTIR analysis further confirmed the chemical properties of the product to be silica coated SPMN.
Comparative Study of the Electrospun PAN Nanofiber Reinforced with CNT and CNF: Effect on Morphology, Thermal Stability and Electro-Conductivity Properties
Authors: Idris Rubia , Puvaneswaren K. , Arshad Sazmal Effendi , Pak Yan Moh , Noraini A. , Shaheen M.K. , Jahimin A. Asik
Published: June 2015

Reinforced electrospun PAN nanofibers with carbon nanotubes and carbon nanofibers were produced via electrospinning techniques. The spinning was carried out in a ratio of 6 and 10 wt % of CNT and CNF to PAN slurry respectively. The applied voltage was 10.0 kV and the spuns had undergone three stages of thermal treatments, namely, stabilization, carbonization, and graphitization. The studies indicated that the nanofiber diameter, thermal stability and electric conductivity properties of the PAN electrospun were greatly affected by the ratio of the nanoparticles. The morphological study revealed that the fiber diameters of the PAN/CNT electrospun were between 0.62 to 0.70 mm, and the PAN/CNF fiber diameters were between 1.03 to 1.20 mm respectively. For the thermal stability study, it was observed that the thermal degradation of the PAN polymer had increased as the CNT and CNF ratios increased. The electro-conductivity study also revealed that addition of CNT had increased the conductivity of the PAN polymer until 5.4 x 10-4 Scm-1 besides PAN/CNF increased the electrical resistivity of PAN from 2.49 x 10-5 to 1690.2 Ω cm-1 respectively.
The Effect of CuO on NiO Electroceramics
Authors: Kui Tan Guan , Ab Rahman Mohd Fariz , Ahmad Zainal Arifin , Mohamed Julie Juliewatty
Published: June 2015

The Ni1-xCuxO was prepared from raw materials of NiO and CuO via solid state reaction. This study was focuses on undoped and CuO doped NiO properties. CuO was used as dopant with five different concentrations. The powders were mix for 24 hours and followed by calcinations at 900°C for 2 hours. The calcined powders were compacted to a 5 mm diameter pellet form, by applying 200 MPa pressure. Then, the pellets were sintered at temperature 1200°C for 12 hours. After that, the samples were analyzed by using XRay diffraction (XRD) in order to identify the phase formation, scanning electron microscopy (SEM) for the microstructure and surface topography observation, density measurement by Archimedes principle and impedance analyzer in order to measure the dielectric properties. XRD results show that all sintered pellets produce a single phase of Ni1-xCuxO. In addition, increase of Cu dopant concentration causes the lattice parameter getting larger. Apart from that, SEM shows that more addition of Cu dopant increase the grain size. The density is also improved, due to formation of bigger grain size lead to an increasing in density. Impedance analyzer results show the dielectric behaviour of the samples was improved with increasing of CuO content. The 0.10 mol% CuO obtained optimum dielectric properties with lowest dielectric loss measured at 1 GHz (0.008).
Effect of Calcination on the Basic Strength of Surface Modified Nano-Zinc Oxide Characterised by FTIR and Back Titration Methods
Authors: Yacob Abdul Rahim , Kabo Kamaluddeen Suleiman
Published: June 2015

The use of metal oxides in heterogeneous base catalysis has gained a large interest due to their application in many chemical and industrial processes and is environmental friendly. Basic metal oxides are commonly used and their structures, morphology and performance can be modified by method of preparation and thermal activation. In this study, surface modified amphoteric zinc oxide was prepared via hydration-dehydration method and characterised by TGA and FTIR. The basic strength at various temperatures is characterised by FTIR and back titration analyses. The results shows that surface modified zinc oxide has the highest basic strength of 1.453mmolg-1 at 400°C making it a relatively good and suitable compound for use in heterogeneous basic catalysis. This result is also supported by FTIR spectra which show possible relationship between the Lewis O2- and increasing basic strength.
Deacidification of Acidic Petroleum Crude Oil Utilizing a Formulated Basic Chemical
Authors: Mohd Shukri Nurasmat , Jaafar Jafariah , Wan Abu Bakar Wan Azelee , Abdul Majid Zaiton
Published: June 2015

An increasing interest in acidic fractions in crude oil was prompted by the corrosion problems that these compounds caused during oil refining process. This corrosion is associated with the total acid number (TAN). With the anticipated growth of acidic crudes in the market, a new technology for removal of the acidic fractions was introduced. Petronas Penapisan Melaka Light Crude (B) with TAN values of 2.52 was studied. The ammoniated polyethylene glycol (PEG) was used as the deacidifying agent in this study with a concentration range of 100-2500 mg/L. Data indicated that the optimal content of ammoniated polyethylene glycol in crude B was 1500 mg/L, and PEG with molecular weight of 2000 was the most promising co-solvent with the reagent/oil ratio being 0.4:1 (wt/wt). A reaction time of 5 min with a suitable reaction temperature of 40°C and optimal stirring time of 5 min were sufficient to achieve the goal for crude oil B. The TAN was lowered to 0.28 for crude oil B. The percentage of acid removal for crude B was 78. An increase in the concentration of basic chemical reduced the TAN value for crude oil B to less than 1.
Efficient Oxidative Desulfurization (ODS) of Commercial Diesel with TBHP under Mild Conditions Catalyzed by Polymolybdates Supported on Al2O3
Authors: Wan Abdullah Wan Nazwanie , Ali Rusmidah , Wan Abu Bakar Wan Azelee
Published: June 2015

Due to the low specifications for sulfur content in diesel, a lot of research work are been conducted to develop alternative method for desulfurization. Catalytic oxidative desulfurization (Cat-ODS) has been found to be an alternative method to replace a conventional method which is hydrodesulfurization.New catalyst formulation using tert-butyl hydroperoxide polymolybdate based catalyst system was investigated in this research utilizing tert-butyl hydroperoxide (TBHP) as oxidant and dimethylformamide (DMF) as solvent for extraction. A series of polymolybdate supported alumina catalysts were prepared using wet impregnation method, ageing at ambient room temperature for 24 hours and followed by calcination process. A commercial diesel with 440 ppmw of total sulfur was employed to evaluate the elimination of sulfur compounds. Besides, the percentage of sulfur removal was measured by gas chromatography-flame photometric detector (GC-FPD). The sulfur content in commercial diesel was successfully reduced from 440 ppmw to 35 ppmw under mild condition followed by solvent extraction. From catalytic testing, Mo-Al2O3 calcined at 500°C was revealed as the most potential catalyst which gave 92% of sulfur removal.
Screening of Factors Affecting Pre-Treatment by Ammonia-N Removal from Poultry Manure Wastewater by Using Soil Water to Improve Biogas Production
Authors: Mohd Jamaludin Nina Farhana , Zainol Norazwina
Published: June 2015

In this study, best pre-treatment condition of poultry manure wastewater (PMW) was determined from factorial analysis for the purpose of improving biogas production. Five factors were chosen for factorial screening namely: agitation (0 or 200 rpm), reaction time (2 to 5 hours), type of soil (peat soil or poultry farm soil), soil to water ratio (1:1 or 1:4) and PMW to soil water (SW) ratio (1:4 or 2:3). Based on the result, agitation gave highest contribution in pre-treatment of PMW at 38.36% followed by PMW to SW ratio at 29.76% contribution. In term of interaction, agitation and reaction gave the highest contribution to pre-treatment of PMW at 3.33% contribution. The best pre-treatment condition suggested by Design Expert software was using peat soil as source of soil at SW ratio of 1:6, and mixed with PMW at 1:4 ratio without agitation for 5 hours reaction time. Application of this best pre-treatment condition showed improvement in biogas yield by 82 % from 0.0045 L/g COD using untreated PMW to 0.0248 L/g COD using treated PMW.
ZnO Nanoparticles Concentration Dependent Optical Properties of Erbium Doped Phosphate Glass
Authors: Arifin R. , Zulkifeli Nur Asilah , Sahar Md Rahim , Ghoshal Sib Krishna
Published: June 2015

Precise manipulation of nanoparticles (NPs) in rare earth doped inorganic glasses for achieving tuneable physical and optical properties is challenging. Series of erbium doped phosphate glasses containing ZnO NPs with composition (78.5-x)P2O510Li2O10ZnO1.5Er2O3(x)ZnO, where 0x1.2 are prepared using melt quenching method. The local structures analyzed using FTIR spectra reveal an increase in depolymerisation of the glass at Q3 tetrahedral sites due to the introduction of ZnO NPs. The optical band gap energy obtained from UV-Vis absorption spectra varies within 3.533.59 eV and the Urbach energy increase as much as 0.260 eV. The role of ZnO NPs within the lithium (II) oxide-zinc oxide-phosphate glass matrix in influencing the optical and structural responses are analyzed and discussed. The observed optical improvements suggest that these glasses are potential for photonic devices.
Density Functional Theory (DFT) Calculation of Band Structure of Kesterite
Authors: Basri Katrul Nadia , Zabidi Noriza Ahmad , Abu Kassim Hasan , Rosli Ahmad Nazrul
Published: June 2015

The kesterite, Cu2ZnSnS4 has a big potential as a future solar material in replacing current material. Although the kesterite and copper indium gallium selenide, CIGS has almost same structure but the constituent elements of kesterite are earth-abundance, cheaper and non-toxic. The chalcogen elements existed inside the kesterite compound are selenium and sulphur, Cu2ZnSnSe4 / Cu2ZnSnS4. Therefore, the structural flexibility of kesterite opens up an avenue to develop light-absorber material with suitable properties and applications. The density functional theory (DFT) has been used to calculate the total energy of Kesterite developed from Material Studio - CASTEP. The general gradient approximation (GGA) has been choosing to treat the exchange-correlation. The structure of kesterite has been developed by determining its space group, I4 and Pc and its coordination of each atom. The previous calculated shown that the energy of its band gap is around 1.0-1.5 eV.
Effect of the Ge Mole Fraction on the Electrical Characteristics of Single and Dual Channel Vertical Strained SiGe Impact Ionization MOSFET (VESIMOS)
Authors: Ismail Saad , Bun Seng Chan , Mohd Zuhir Hamzah , Bolong Nurmin , Anuar Mohamad Khairul , Bablu Ghosh
Published: June 2015

The effect of the Ge mole fraction in a Si1-xGex on single and dual channel Vertical Strained SiGe Impact Ionization MOSFET was successfully analyzed. It is found that the threshold voltage, breakdown voltage and sub-threshold slope of the devices was affected by the presence of the Germanium. A better performance in sub-threshold voltage of the devices was obtained for dual channel VESIMOS compared to single channel VESIMOS with a suitable amount of Germanium. Germanium has high and symmetric impact ionization rates to ensure the transition from OFF state to ON state is abrupt. With the appearance of the SiGe layer in the devices, has an advantage of the mobility enhancement of carriers in the devices operation. With the improvement of the Ge composition, it could transform VESIMOS into a new paradigm of devices which applicable to nanoelectronics with better electrical characteristics.
DFT Investigations of Ti, V Doped ZnO Based Diluted Magnetic Semiconductors
Authors: Ul Haq Bakhtiar , Ahmed R. , Shaari A. , Hussain R. , binti Mohamad Mazmira
Published: June 2015

The injection impurity element into ZnO has added new dimension to its versatile applications particularly in spintronics and optoelectronics. In this work, we are reporting effect of non magnetic Ti, and magnetic V impurities in ZnO. The substitution of impurity atoms have been done in ground state wurtzite (WZ) and meta stable zinc-blende (ZB) structure. Our investigations have revealed a small difference in WZ and ZB geometries of contaminated ZnO reflecting on the possibility of their experimental fabrication. Spin polarized electronic structures resembled nonmagnetic nature of Ti:ZnO in WZ and magnetic nature in ZB geometry. Similarly introduction of V in to ZnO induced magnetization in ZnO in both WZ and ZB geometry. For these investigations, we have adapted DFT approach using FP-L(APW+lo) method implemented in WIEN2k code.
Multiple Regression Model on Optical Properties of Tin Oxide Thin Film
Authors: Md.Yassin Fouziah , Baco Saturi , Abdullah Noraini
Published: June 2015

Tin Oxide (SnO2) thin film is one of the important transparent conducting oxides (TCOs) due to its electrical and optical transparency in visible light spectrum. This study presents the best model in estimating optical properties of tin oxide thin film which is performed using the absorption coefficient of the film. The annealing temperature is at 473 K prepared by radio frequency sputtering technique. Twelve multiple regression (MR) models with interactions are generated from three independent variables (transmission spectra, energy band gap and the wavelength of light). They are developed from data sets of 50. The best model M8.0.0 is chosen from the 6 selected models based on the Eight Selection Criterion (8SC). Best model will have the majority criteria with the least value. Factors affect the absorption coefficient are found to be X1 (transmission spectra), X2 (energy band gap) and X1X2 (interaction between transmission spectra and energy band gap).
Impedance and Resistivity Behavior of Graphene Oxide-Activated Carbon Hybrids
Authors: Md Ali Ruslinda , Kamisan Ainnur Sherene , Kamisan Ainnur Izzati , Tunku Kudin Tunku Ishak , Hatta Faizatul Farah , Hassan Oskar Hasdinor , Yahya Muhd Zuazhan
Published: June 2015

We measured the resistivity and conductivity behavior of activated carbon and an activated carbon – graphene oxide (GO – AC) hybrid using two point probe method. As graphene oxide is well known as insulator, the effects of different ratio of activated carbon on conductivity of hybrid GO – AC was investigated.
Fabrication and Analysis of Photoelectrochemical Properties of Dye Sensitized Solar Cell Using Local Borneon Natural Dye Extracts
Authors: Ung Mee Ching , Mansa Rachel Fran , Sipaut Coswald Stephen , Dayou Jedol
Published: June 2015

Natural dyes were extracted from the plant species Etlingera elatior, Duranta erecta and Amaranthus spp. that were collected from Keningau and Tambunan, Sabah, Malaysia. The possibility of photon-electron conversion was then assessed based on their absorption ability in the region of wavelength between 400-900nm. In addition, FT-IR analysis was carried out to determine if functional groups exists in their extracts. Finally, the DSSCs were assembled and their efficiency measured. It shows the successful conversion from visible sunlight to electricity by using extracts from Etlingera elatior, Duranta erecta and Amaranthus spp. as raw natural dye sensitizers in Dye Sensitized Solar Cells (DSSCs) with efficiency of 0.1% ,0.06% and 0.04%, respectively. This result shows that local natural dyes can be used as sensitizer in DSSCs. However, further investigations are required to improve the efficiency.
Formation of Kirkendall Voids at Low and High Aging Temperature in the Sn-0.7Cu-1.0wt.%Si3N4/Cu Solder Joints
Authors: Saud Norainiza , Somidin Flora , Ibrahim Najib Saedi , Mohd Salleh Mohd Arif Anuar
Published: June 2015

The intermetallic compounds (IMCs) layer formed between Sn-0.7Cu-1.0wt.%Si3N4 (SC-1.0SN) solder and Cu-substrate were investigated through isothermal solid-state aging. The SC-1.0SN/Cu solder joints were aged at 50°C and 150°C for 24h, 240h, 480h and 720h duration after reflow. The as-soldered joint IMC formed at interface was Cu6Sn5. In addition, only Cu6Sn5 layer was observed at the interface of the samples aged at low temperature of 50°C although the aging duration was prolonged up to 720h and has begun to increase in thickness. On the other hand, the Cu3Sn layer was clearly observed in the sample of aged at 150°C up to 240h. However, at least no voids were vividly observed in the 50°C aged samples, while kirkendall voids were clearly found in Cu3Sn layer of samples aged at 150°C up to 480h of aging time will be discussed further.
The Microstructure Evolutions of Sn-0.7Cu Solder Using Microwave-Assisted Sintering Method at Various Exposure Times
Authors: Somidin Flora , Saud Norainiza , Mohd Salleh Mohd Arif Anuar
Published: June 2015

This study investigates the effect of microwave-assisted sintering on microstructure evolution and microhardness of Sn-0.7Cu green compact solder. Results showed that microwave-assisted sintering has shortened the sintering duration compared to conventional process. Microstructural characterization revealed that the 800W (2.45GHz) microwave power combined with SiC microwave susceptor heating showed rapid particle grain evolution within 120 seconds. In order to get similar grain evolution, 2 hours of sintering duration was needed for conventional sintering. Results were also revealed that the microhardness of the Sn-0.7Cu green compact also decreased as the microwave exposure time is increased.
Effect of Sintering Temperature on the Superconducting Properties of MgB2 Superconductor Co-Added with a High Concentration of Si and C
Authors: Tan Kwee Yong , Tan K.B. , Lim Kean Pah , Halim Shaari Abdul , Chen Soo Kien
Published: June 2015

In this study, as much as 10 and 15 wt.% nanosized silicon and carbon (Si+C) were reacted with (Mg+2B) at 650°C and 850°C, respectively, for 1 hour. The phase formation, surface morphology and superconducting properties of these samples were evaluated. The relative peak intensity as calculated from the XRD patterns indicates the formation of large Mg2Si volume fraction at low sintering temperature. MgB4 phase was detected in the samples sintered at high temperature as a result of Mg deficiency. The C substitution level as estimated from the lattice parameters, was shown to increase in the samples reacted with a higher amount of (Si+C) at high temperature. Scanning electron micrograph showed that (Si+C) co-addition had refined the grain size and improved the grain coupling of MgB2. The superconducting transition temperature was found to decrease with increasing addition level. The superconducting transition width was also broadened because of a large volume fraction of secondary phases. The improved field dependent critical current density at both 5 K and 20 K is accounted to enhanced scattering by C substitution and grain boundary pinning.
Structural and Superconducting Properties of Bi-Based Low Density HTSC
Authors: Azura C.M.N. , Azhan H. , Azman K. , Syuhaida I.N. , Robaiah M. , Rosli Mohd Mustaqim
Published: June 2015

Low density HTSC with nominal composition of Bi1.6Pb0.4Sr2Ca2Cu3Oy filled with crystalline sucrose has been synthesized and its structucal and superconducting properties have been studied. The transport properties, morphology, density and structural identification were determined by using the standard four point probe, Field Emission Scanning Electron Microscope (FESEM), densitometer and X-ray diffraction (XRD) respectively. The critical current density (Jc) of optimized ratio of crystalline sucrose onto Bi-2223 powder used to produce low density Bi-based superconductor was found to be higher than the bulk polycrystalline sample. TC zero obtained was varied between 93 and 101 K towards the increment ratio of crystalline sucrose with the highest TC zero = 101 K for ratio of 0.050:1.950 and decrease gradually for further addition of cystalline sucrose. The crystallographic structures was found to be remained in tetragonal where a=b≠c. The grains with higher porosity resulting in decreasing of critical current density (Jc) as well as critical temperature (Tc zero) due to lack of effective area of current flows.