bluuebunny/crossref_metadata_2025 huggingface dataset:
Synthesis of Barium Hexaferrite with Addition of Tapioca as Rodlike Template
Authors: Septiadi Arifin , Purwasasmita Bambang Sunendar
Published: October 2014

Barium hexaferrite is categorized as hexagonal ferrite material with ferrimagnet properties. Barium hexaferrite has high coercivity, curie temperature, anisotropy magnetic field, and chemical stability that is often used as permanent magnet. It can be synthesized by using bottom up or top down method. The bottom up method of sol-gel has potential advantages in industry application compared to the top down method because of low energy requirement, more homogeneous product, and low time consuming to achieve nanometer size. The development of sol-gel method by using tapioca and chitosan as surfactant increases the quality of the product. Tapioca is used to increase anisotropy properties of particles by changing the particles shape into rodlike shape whereas chitosan is used to stabilize them at small size. Molar ratio of Fe3+/Ba2+ is set on 12 and the ratio of tapioca/chitosan is set on 1/3, 1/2, and 1. Iron (III) nitrate is used as Fe3+ source whereas barium nitrate is used as Ba2+ source. Condensation is done by heating up the sol system in the oven at 100OC. The product then is calcined at 1000OC with holding time of 3 hours. The calcined product is then characterized by X-Ray Diffraction (XRD), Scanning Electron Microscope (SEM), and Vibrating Sample Magnetometer (VSM). XRD result shows that the hematite phase has still been formed. The occurrence of the phase indicates that the reaction between iron and barium is uncompleted. SEM images show the existence of needle and rod-shaped particles with diameter of 200nm–550nm. It explains that tapioca can be used as rodlike template. The increase of tapioca tends to enlarge the rod-shaped particle and remove the needle-shaped particle. VSM result shows that the highest value of Br is found in the sample of tapioca/chitosan with the ratio of 1/3 and the value of 24 emu/g. The fact indicates that the optimal ratio of tapioca/chitosan is 1/3.
Finite Element Simulation of the Drawability of Tailor-Welded Blank
Authors: Anggono Agus Dwi , Riyadi Tri Widodo Besar
Published: October 2014

Tailored welded blank (TWB) consists of steel sheets of different thicknesses and strength which welded into one sheet to reduce weight and production costs, to increase dimensional accuracy and strength. Since a tailored blank is composed of different sheets of metals having different thicknesses and properties, the forming of tailored blanks then creates a lot of technical problems especially in the scheme of deformation. The objective of this work was to evaluate the drawability of tailored blanks. In order to assess the forming behavior of the tailor-welded blanks under the influence of weld orientations, a finite element and experimental methods were conducted. Three welded specimens with weld lines oriented at an angle of 0°, 90° and 45° with respect to the direction of load were investigated. The finite element result showed in a good agreement with the experimental result. The result of the experiment showed that a welded part was characterized by a higher strength and lower plasticity compared to those of the base material. Hence, the weld influences the strain distribution of the tailor-welded specimens. This phenomenon depends strongly on the direction of the weld against the direction of tensile load. The lowest strains occur in the specimen with a longitudinal weld.
Tensile Properties and Morphology of Recycled Latex Glove Filled Epoxidized Natural Rubber (ENR50) Compounds
Authors: Afiratul A.A. , Noimam N.Z. , Ruzaidi C.M. , Ting Sam Sung , OMAR MOHD FIRDAUS , Hazwan S.M.
Published: October 2014

The effects on the properties of recycled latex glove (RL-G) filled Epoxidized Natural Rubber (ENR 50) were studied. Both compounds were prepared by two roll mill at five different compositions of RL-G (5, 15, 25, 35 and 50 phr). The size range of RL-G particles i.e., S1 (300μm-700μm) and S2 (3cm-5cm) were used. The properties such as tensile properties (tensile strength, elongation at break, and stress at 100% elongation) and morphology studies were determined. The results indicated that the both size, S1 and S2 of recycled latex glove filled ENR 50 blends exhibited an increased in tensile strength and elongation at break for increasing weight ratio of RL-G. Scanning electron microscopy (SEM) of the fracture surfaces shows that the fine size, S1 RL-G/ENR50 exhibited high surface roughness and matrix tearing lines than the coarse size, S2 thus improving the compatibility of RL-G/ENR50 compounds. The results overall indicated that the fine size, S1of RL-G filled ENR50 contributed to the better properties such as tensile strength and surface morphology compared to the coarse size, S2 mainly at 15 phr of RL-G content.
Mechanical Properties of Class C High Volume Fly Ash Concrete with Lime Water as Mixing Water
Authors: Solikin Mochamad , Setiawan Budi
Published: October 2014

This paper reports an investigation on mechanical properties of high volume fly ash (HVFA) concrete produced using different types of mixing water i.e. tap water and saturated lime water. The mechanical properties of ordinary Portland cement concrete are also investigated as control tests. The concrete were tested for their compressive strength, flexural strength and splitting tensile strength at the curing ages of 56 days. The results showed that strength development of high volume fly ash concrete up to 56 days is lower than ordinary portal cement. In addition, the flexural strength and splitting strength of concrete are lower than ordinary Portland cement. Moreover, the use of saturated lime water as mixing water reduces the mechanical properties of class C high volume fly ash concrete.
Development of Pressure Torch Brazing System
Authors: Baskoro Ario Sunar , Wicaksana Rizki Arief , Supermando Pither
Published: October 2014

This study is to develop the process of torch brazing system which transmits the pressure on the workpiece to be brazed. Mechanical stress is given by 0, 0.7, 1.2 and 1.7 MPa. When the filler melts, it cause mechanical pressure to push each sample and cause a reduction in the thickness of the filler. The higher the static pressure is given, the smaller thickness of the filler. Therefore, when the sample is heated, stainless steel expands and resulting thermal stresses. The thinner the thickness of the filler due to mechanical pressure will result in the interaction distance is getting smaller. And with the same thickness of the filler, it will result in greater thermal stress with the increasing mechanical pressure. So the displacement will increase along with the amount of mechanical stress given. By giving stress on the joining process it will affect the joint brazed connections clearance. With the change in the joint clearance will certainly affect the strength of the connection as well. The study was conducted to investigate the effect of the pressure on the strength of joint.
Optimisation of Processing Condition Using Taguchi Method on Strength of HDPE-Natural Fibres Micro Composite
Authors: Ibrahim Mohd Halim Irwan , Zainol M.Z. , Othman Mohd Hilmi , Amin Azriszul Mohd , Asmawi Rosli , Sa'ude Nasuha
Published: October 2014

Injection molding usually uses to produce part from plastic. Other than it is cheap, it also can produce part in large quantity. In this paper, Taguchi Methods was used to define the optimization of process parameter for an injection molding machine to produce a dumbbell product from High-density Polyethylene (HDPE) + natural fiber (Kenaf). Taguchi Methods with L9-34 approaches will be used in this work. Four different formulation of material will be tested to find the best formulation and its parameter setting. Here, an orthogonal array (OA), signal-to-noise (S/N) ratio and analysis of variance (ANOVA) are employed to analyze the effect of injection molding parameter. The significant of formulation and parameter setting from injection molding through the hardness and the strength value of the specimen. Furthermore, test will be conducted through hardness test and tensile test. Changes in the parameter setting will give different hardness and tensile strength value. The optimum parameter setting was set base on the S/N ratio. For each formulation, it has their optimum parameter setting for hardness and for tensile strength. The optimum parameter setting was predicting their S/N ratio using Minitab software.
Dynamic Explicit Finite Element Code for U-Bending Simulation and Springback Prediction
Authors: Anggono Agus Dwi , Riyadi Tri Widodo Besar , Siswanto Waluyo Adi
Published: October 2014

In this paper, a dynamic explicit method was used to simulate U-bending processes of aluminium and its springback. The simulation was carried out using a free software of finite element analysis code namely Impact. The model was taken from a benchmark model in Numisheet'93. The numerical results of the dynamic explicit code were compared with the results of the experimental works. After the optimization was done using the simulation process, it was found that the springback results showed a good agreement with that done by the experimental results. The software Impact was capable of simulating the U-bending processes and predicting the occurrence of springback.
Prediction of Flux Cored Arc Welding (FCAW) Parameters and Bead Geometry in Downhill Position (3F)
Authors: Abd Rahman Nik Mohd Baihaki , Tham Abdul Ghalib , Abas Sunhaji Kiyai , Hassan Razali , Manurung Yupiter H.P. , Redza Mohd Ridhwan Mohammed , Yaakub Mohamad Yazman
Published: October 2014

The robot can perform Flux Cored Arc Welding (FCAW) at high productivity and consistency in quality. The quality of the welding depend on the selection of welding parameter and deposition geometry. These input has to be known before the start of production, generally the welding operator will obtain the information through experimental trial and error. This project planned to develop a tool that can advise the choice of welding parameter that produce quality weld bead with desired geometry. This research focused on the correlation of heat input on weld bead geometry and the range of welding parameter for fillet design welded in downhill direction (3F). From the correlation trend-line equations and welding parameter population boundary, the weld bead geometry and welding parameter for quality deposit are predicted. Consequently two calculators were developed to display the values digitally. The deviation of predicted bead geometry from actual welding is less than 1mm. Mean Absolute Deviation (MAD) is less than 0.4mm, accuracy is good. A wide range of welding parameters can be generated for quality welding at desired bead geometry.
Empty Fruit Bunches Oil as New Lubricant
Authors: Iman Golshokouh , Syahrullail Samion , Farid Nasir Ani
Published: October 2014

In this study, a tribological property of new oil extract from the empty fruit bunches (EFB) of palm fruit was studied as a new alternative source of lubricant oil. The experimental works were did using a fourball tribotester following the ASTM D4172 standard. The wear conditions on the balls surface were examined using CCD microscope and scanning electron microscope (SEM). A similar experimental works were conducted using engine oil as a benchmark for the new tested lubricant. The correlation between coefficient of friction and time was calculated using statistical software. The results showed that empty fruit bunch oil has higher anti-friction and anti-wear ability compared to engine oil.
The Performance of Modified Jatropha-Oil Based Trimethylolpropane (TMP) Ester on Tribology Characteristic for Sustainable Metalworking Fluids (MWFs)
Authors: Talib Norfazillah , Rahim Erween Abdul
Published: October 2014

Metalworking fluids (MWFs) are widely used in machining process to improve its performance and product quality. It acts as a coolant and lubricant to reduce heat between the contact of two surfaces. However, commercial MWFs used in the industry were usually from petroleum-based oil which is toxic to the environment, difficult to dispose and caused significant health. Therefore, it is essential to develop a bio-based MWFs to overcome the aforementioned drawbacks. This study was aimed to determine the effect of chemically modified crude jatropha oil (CJO) with trimethylolpropane (TMP) at different molar ratio on tribological characteristic. The produced TMP esters are compared with synthetic ester in terms of wear scar diameter, coefficient of friction and friction torque. From the result, it shows that modified jatropha oil was equivalent with synthetic ester and provided good lubrication and reduce friction and wear.
Effect of Heat Compression on the Tensile Strength of PALF/Sugarcane Bagasse for Disposable Plate
Authors: Mustapa Mohammad Sukri , Sabdin Saiful Din , Rahim Erween Abdul , Wahab Md. Saidin , Yusof Yusri
Published: October 2014

This paper presents the results of heat compression effect on tensile properties in manufacturing process of disposable plate from Pineapple Leaf Fibers (PALF) based material. The plate was made of PALF and sugarcane bagasse waste as alternatif to polystyrenes to promote the green technology efford on food packaging material. Two different spesimens were produced with different composition of PALF/sugarcane bagasse, N2T8 (20% Pineapple leaf fiber and 80% sugarcane bagasse and N8T2 (80% pineapple leaf fiber and 20% sugarcane bagasse). The specimens were produced on a hot press machine at different compressing temperature, 50°C, 100°C and 150°C with constant pressure of 0.024 MPa at 10 minutes. Tensile and tearing tests were carried out on the specimens to determine the tensile and tearing properties. The results shown that the N2T8 speciment compressed at 50°C gives higher tensile and tearing strength of 22 MPa and 2 MPa ,respectively. This range of properties is expected to be good enough for the requirement of disposable plate and it has a potential as a raw material for strength and lightweight of disposable plate manufacturing.
Thin Layer Modeling of Grated Coconut Drying
Authors: Zainal Abidin Muhammad Hanif , Sabudin Sulastri , Zakaria Jamal Hazri , Mohideen Batcha Mohd Faizal
Published: October 2014

With the increasing demand for new and energy efficient drying methods of agricultural products, various techniques were deviced by researchers around the world. This techniques usually developed in laboratory scale prior to scale-up for actual industrial application. During this stage, modeling usually involved to aid scaling up process. This paper presents the modeling of drying kinetics of grated coconut using three semi emperical thin layer model. These models were Logarithmic, Modified Handerson and Pabis, and Verma et al models. Moisture ratio predicted by these models were compared against experimental drying carried out at four temperatures: 50°C, 60°C, 70°C and 80°C. The performance of these models were analyzed statistically using non-linear regression using LabFit software. The statistical parameters analyzed were coefficient of determination (R2), reduced Chi-square (X2), Root Mean Square Error (RMSE) and Residuals. Higher R2 with lower X2, RMSE and Residuals implies good predictability of the models. From the analysis, it was found that Logarithmic model yields the best predictive capability of grated coconut drying kinetics with R2 = 0.9996387, X2 =0.505535x10-3, RMSE = 0.00623597 and Residuals = 0.0703607.
The Influence of Sewage Fat Composition on Rheological Behavior of Metal Injection Moulding
Authors: Amin Azriszul Mohd , Ibrahim Mohd Halim Irwan , Asmawi Rosli , Mustafa Najwa
Published: October 2014

Influence of sewage ratio or Fat Oil Grease (FOG) on the feedstock rheological characteristic for optimal binder formulation in metal injection moulding is evaluated besides Polypropylene (PP) as a backbone binder. Powder loading of 62% of water atomised SS316L being used here to determine the possibility of the best binder formulation which could be optimised for optimal powder loading base on rheological characteristic analysis. Two binder formulations of PP to SF being selected here are 60/40, 50/50 and 40/60 accordingly with the powder loading of 62% each binder formulation. The analysis will be base on viscosity, shear rate, temperature, activation energy, flow behaviour index and moldability index. It is found that from rheological result views, binder with composition of 60/40 and 50/50 exhibit pseudoplastic behaviour or shear thinning where the viscosity decrease with increasing shear rate. For 40/60 binder ratio is not suitable since the behaviour of the flow indicates dilatants behaviour. After considering all the criteria in terms of flow behaviour index, activation energy, viscosity and mouldability index, binder with ratio of 60/40 is evolve as a good selections.
CO2 Absorption in a 5M Aqueous Solution of 2-(Diethylamino)Ethanol
Authors: Maneeintr Kreangkrai , Boonpipattanapong Pattara , Assabumrungrat Suttichai , Charinpanitkul Tawatchai
Published: October 2014

Currently, climate change and global warming are the main issues on environmental concern due to the higher amount of carbon dioxide in the atmosphere. The main sources of carbon dioxide are energy-related activities such as power generation. Now, the effective technology to remove CO2 from these sources is absorption especially with amine solution. The commercially used amine solutions are monoethanolamine (MEA) and methyldiethanolamine (MDEA). Nevertheless, they also have disadvantages such as low capacity, corrosion and high energy requirement. Therefore, many new solvents have been developed to improve efficiency for CO2 capture. Therefore, the objective of this work is to measure the vapor-liquid equilibrium of CO2 in a 5M aqueous solution of 2-(Diethylamino) ethanol (DEAE) as a novel solution 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 DEAE solution are compared with those of aqueous solution of MEA. For cyclic capacity, the results present that DEAE provides higher performance which is up to 861% higher than that of MEA. This means that DEAE can save more energy and cost for solution regeneration.
Thermal and Electrical Experimental Characterization of Ethylene Glycol and Water Mixture Coolants for a 400 W Proton Exchange Membrane Fuel
Authors: Zakaria Irnie Azlin , Michael Zeno , Hanapi Suhadiyana , Wan Mohamed Wan Ahmad Najmi
Published: October 2014

Nanofluid is an emerging technology in heat transfer study. The effect of nanofluids as a cooling medium in Proton Exchange Membrane Fuel Cell (PEMFC) is studied. Nanofluids with 0.1% and 0.5% of Al2O3 dispersed in base fluid of 50:50 mixture of Ethylene Glycol and water were analyzed experimentally. A 400 W liquid cooled PEMFC was used to verify the findings. The result showed that insignificant improvement in performance of PEMFC with nanofluids, perhaps due to the lower wattage of PEMFC used. However, the thermal performance is improved through the heat transfer rate increment of 68.5 % and 46 % for both 0.5 % of Al2O3 nanofluid and 0.1 % of Al2O3 nanofluid respectively.
NOx Emission of Diesel Fuel Blended with Different Saturation Degrees of Biofuel and with Oxygenator
Authors: bin Abdullah Mohd Fareez Edzuan , bin Sulaiman Mohd Hisyamuddin , Abdul Majid Noor Aliah Binti
Published: October 2014

This paper discusses the nitrogen oxides (NOx) emission characteristics of compression ignition diesel engine operating on diesel fuel blends with different saturation degrees of biofuel and with methanol. In order to investigate the dominant factor of increased NOx in biofuels, diesel combustion tests were conducted under idling condition and the tailpipe exhaust emissions were measured by a flue gas analyzer. The general trend where NOx emission increased and reduced carbon monoxide (CO) emission in the biofuel and methanol blend cases were observed. The NOx emission levels increased as the biofuel saturation degree decreased, where it may be suggested that the prompt NOx mechanism is significant in total NOx formation of biofuel combustion process.
The Performance of Brass Electrode on Material Removal for Aluminium Composite in EDM Die-Sinking
Authors: Mohd Amran Ali , Laily Suraya , Fatin Aisyah , Hussein Nur Izan Syahriah , Muhamad Mohd Razali , Manshoor Bukhari , Lajis Mohd Amri , Raja Izamshah , Mohd Hadzley , Taufik Taufik
Published: October 2014

This paper investigates the performance of brass electrode on the removal of aluminium alloys LM6 (Al-Sil2) in an electrical discharge machining (EDM) die-sinking. The machining parameters such as pulse-on time, pulse-off time and peak current were selected to find the responses on the material characteristics such as material removal rate (MRR), electrode wear rate (EWR) and surface roughness (Ra). Brass with diameter of 10mm was chosen as an electrode. Orthogonal array of Taguchi method was used to develop experimental matrix and to optimize the MRR, EWR and Ra. It is found that the current is the most significantly affected the MRR, EWR and Ra while pulse on time, pulse off time and voltage are less significant factor that affected the responses. Percentage optimum value of MRR increases to 3.99%, however EWR and Ra reduce to 3.10% and 2.48% respectively. Thus, it shows that brass having capability to cut aluminium alloys LM6.
Hydrogen (Al+HCl) Improve the Combustion of Gasoline Engine and Reduction the Hydrocarbon and Carbon Monoxide up 33% to 34%
Authors: Razali Halim , Sopian K. , Mat S.
Published: October 2014

The requirement of hydrogen in the transport system is indispensable nowadays. Especially to fulfill the requirement from the transports and industry sector related with green technology implementation. As an alternative, a research has been conducted from a technical aspect on the profitability of using hydrogen onboard as fuel for internal combustion engine. Applications using a mixture of Gasoline with hydrogen (G+H2) can be used to increase the combustion performance especially on the reduction of hydrocarbon and carbon monoxide. In this study hydrogen as an alternative fuel in four-stroke motorcycles has been tested using a chassis dynamometer model ATV Inertial Dyno, 054-500-1K. Hydrogen requirement in the petrol mixing ratio is dependent on the operating system of the engine ignition system which is controlled by hydrogen pressure in the cylinder. Three stages of load test on the engine performance have been conducted on the chassis dynamometer, namely, load test L0 is equal 0 ampere (L0), load test L1 is equal 1 ampere, and load test L2 is equal 2. During the tests L0, L1 and L2, the average hydrocarbon gas readings decreased by 34 % and 58.2% (L0), 27.4% (L1) and 16.7% (L2) to 46ppm, 85ppm and 95ppm respectively versus gasoline engine 110ppm, 117ppm and 114ppm. And the overall average results of this study showed a reduction of carbon monoxide by 33 %. It proves the use of hydrogen (AL + HCl) in the stoichiometric ratio helps combustion when the oxygen content in the air and fuel mixture is not adequate especially for vehicles using gasoline as a fuel.
Combustion Characteristic of a Diesel Engine Operating with Methanol as Alternative Fuel
Authors: Kathri Akasyah M. , Mamat Rizalman , Aziz Amir Bin , Alias Azri , Abdullah Nik Rosli
Published: October 2014

Modelling the compression ignition engine mostly depends on fuel characteristics. The proses involve a model of the real system and carry out experiment as a mean of comparison to understand the behaviour of the system. The diesel engine nowadays operated with different kind of alternative fuels such as natural gas and biofuel. The aim of this article is to study the combustion characteristic occurred in an engine cylinder of a diesel engine when using biofuel. The one-dimensional numerical analysis using GT-Power software is used to simulate the diesel engine. The engine operated at full engine load and difference speed. The methanol fuel used in the simulation is derived from the conventional methanol fuel properties. The analysis of simulations includes the cylinder pressure, combustion temperature and rate of heat release. The simulation result shows that in-cylinder pressure for methanol is slightly higher than diesel fuel in any speed of the engine. It also found that the combustion characteristic on methanol temperature is higher at all crank angle degree of diesel fuel. Mass fraction burns of methanol are much lower than diesel fuel, but burns faster than diesel fuel.
Experimental Investigation of Emissions Characteristics of Small Diesel Engine Fuelled by Blended Crude Palm Oil
Authors: Khalid Amir , Anuar M.D. , Sapit Azwan , Razali Azahari , Manshoor Bukhari , Fawzi Mas , Zaman Izzuddin Bin
Published: October 2014

Biodiesel is an alternative, decomposable and biological-processed fuel that has similar characteristics with mineral diesel which can be used directly into diesel engines. Crude palm oil (CPO) is one of the vegetable oil that has potential for use as a fuel in diesel engine. However, Biodiesel is also an oxygenated fuel and more density, viscosity meaning it contains influences the emissions production during burning process. Despite years of improvement attempts, the key issue in using crude palm oil fuels is oxidation stability, high viscosity and much oxygen comparing to diesel fuel. Thus, the improvement of performance and emission exhausted from biodiesel fuels is urgently required to meet the future performance and emission regulations. Purpose of this study is to explore how significant the effect of biodiesel blends on the exhaust emission with different speed. The engine speed was varied from 1500-2500 rpm and CPO blending ratio from 5-15 vol% (B5-B15).The emission parameter have been tested in term of opacity, hydrocarbon (HC), nitrogen oxide (NOX), carbon dioxide (CO2 ) and oxygen (O2). Increased blends of biodiesel ratio is found to enhance the combustion process, resulting in decreased the HC emissions and also other exhaust emission element. The improvement of combustion process is expected to be strongly influenced by oxygenated fuel in biodiesel content.
Performance Evaluation of Electrical Discharge Machining Die Sinking on Stainless Steel 316L Using Copper Impregnated Graphite
Authors: Safiei Wahaizad , Sharif S. , Mansor Ahmad Fairuz , Mohd Isa Mohd Halimudin
Published: October 2014

This study presents the results of experimental studies carried out to conduct a comprehensive investigation on the influence of Electrical Discharge Machining (EDM) input parameters on characteristics of EDM process. The machining parameters include peak current, servo voltage, pulse ON time and pulse OFF time. The study was conducted using 2 levels of Full Factorial Method in Design of Experiments. The design expert software employed to perform all the data analysis for Full Factorial and Central Composite Design (CCD) experiments. This study evaluates the machining performance of the Stainless Steel 316L using Sodick EDM linear motor series AM3L which employed Copper impregnated graphite diameter 7.0 mm as the tool electrode. The response variables are material removal rate (MRR), electrode wear rate (EWR), surface roughness (SR) and dimensional accuracy. The result shows that the peak current was the most significant factors to all variable responses. The servo voltage does not have significant effects to the machining responses in RSM. Higher current produced higher MRR, EWR, SR and Dimensional Accuracy. Maximum MRR was obtained at peak current range from 27amp to 38amp, pulse on time range from 120μs to 145μs and 60μs of pulse off time. Maximum EWR was obtained at peak current range from 27amp to 37amp, pulse on time range from 140μs to 160μs and 60μs of pulse off time. High probably, the minimum EWR only can be obtained if peak current parameter sets greater than 45amp. Lower dimensional accuracy and SR obtain at 5amp of pulse on time. Higher pulse off time produced lower MRR and EWR.Keywords: EDM Die sinking, Stainless Steel 316L, Copper Impregnated Graphite Electrode, Response Surface Methodology, Surface Roughness, Material Removal Rate, Electrode Wear Rate, Dimensional Accuracy
The Aerodynamics Analysis on Cambered Fuselage Model
Authors: bin Md Shah Mohd Zarif , bin Abu Bakar Mohd Ridh , Basuno Bambang
Published: October 2014

There various factors gives influence in determining the fuselage shapes, such as the payload, cockpit, wing and tail placements or in manner up and down loading the payload for a cargo aircraft. These factors may come up the fuselage is no longer as symmetrical fuselage but represent as a cambered fuselage. As results the lift coefficient as well as its pitching moment coefficient is no longer equal to zero as the angle of attack goes to zero. Basically the manner how to determine the fuselage aerodynamics characteristics for cambered fuselage can be done in similar way as in the case of symmetrical fuselage by simply replacing the angle of attack α term with (α-αL=0), where αL=0 represent the angle of attack at zero lift. The present work use a similar manner in determining the zero lift angle of attack as it had been used in DATCOM software. To investigate the effect of camber on the aerodynamics characteristic fuselage, the present work use a fuselage model with a circular cross section where the location of center of the circle placed along the fuselage’s camber line. The fuselage’s camber line defined according to the definition of camber line of NACA airfoils. Aerodynamics analysis on over various fuselage models indicate that the maximum camber line thickness and their position give a significant influent to the fuselage aerodynamics characteristics.
An Evolution of Hybrid Airship Vehicle (HAV) Envelope: Aerodynamics Analysis
Authors: Mahzan Muhammad Iyas , Muhamad Sallehuddin
Published: October 2014

HAV has a potential application as the new means to carry Ultra Heavy Payload cargo since it combines the buoyancy capabilities of Lighter-than-Air (LTA), and the aerodynamics of lifting body of Heavier-than-Air (HTA) for speed. Due to its potential, American Institute of Aeronautics and Astronautics (AIAA) has issued a Request for Proposal (RFP) regarding the Hybrid Airship Vehicle (HAV) as cargo transportation with several requirements. AIAA RFP required an envelope that can produce 60% of the lift from buoyancy and 40% of lift from aerodynamic. To satisfy the RFP requirements, this paper analyzed 4 different designs using Computational Fluid Dynamic (CFD) software. Design 4 was chosen as the final design because it meets all the requirements. It was found that at 5° Angle of Attack (AOA), the envelope produce highest aerodynamic lift over drag (L/D) ratio of 3.79. At higher AOA, flow separation occurs at the envelope tail section jeopardizing the aerodynamic characteristic of Design 4 envelope. The lift and drag force graphs were plotted at this AOA and it was found that the HAV envelope is capable of performing the tasks in the RFP.
Study of Passive Vibration Absorbers Attached on Beam Structure
Authors: Zaman Izzuddin Bin , Mohamed Salleh Muhammad , Ismon Maznan Bin , Manshoor Bukhari , Khalid Amir , Mohd Sani Mohd Shahrir , Araby Sherif
Published: October 2014

Structural vibration is undesirable, wasting energy and possibly leading to excessive deflections and structure and machine’s failure. In order to reduce structural vibration, one of the common way is considering vibration absorber system attach to the structure. In this study, a vibration absorber is developed in a small scale size. The host structure selected for the study is a fixed-fixed ends beam. The effectiveness of vibration absorbers attached to a beam is investigated through experimental study. In prior to experiment, a finite element analysis of Solidworks® and analytical equations of Matlab® are produced in order to determine the structural dynamic response of the beam, such as the natural frequency and mode shapes. The preliminary results of finite element analysis demonstrate that the first five natural frequency of fixed-fixed end beam are 17Hz, 46Hz, 90Hz, 149Hz and 224Hz, and these results are in agreement with the beam’s analytical equations. However, there are slight discrepancies in experiment result due to noise and error occurred during the setup. In the later stage, the experimental works of beam are performed with attached vibration absorber. Result shows that the attachment of vibration absorber produces better outcome, which is about 45% vibration reduction. It is expected that by adding more vibration absorber to the structure, the vibration attenuation can significant.
Underwater Acoustics Evaluation of Glass Fiber – Polyurethane Sandwich Composite
Authors: Diharjo Kuncoro , Ubaidillah Ubaidillah , Raharjo Wijang Wisnu , Pitoyo Joko , Mustaqim Mustaqim
Published: October 2014

This article presents underwater acoustics evaluation of glass fiber – polyurethane sandwich composite which is useful for ship materials. The composite consists of two main functional laminations namely structural and acoustical lamination. The structural lamination is constructed from polyester and polyethylene fibers while the polyurethane is potential for acoustical lamination. The fabrication involves vacuum bagging and conventional hydraulic methods. The materials will be treated in both with and without immersion in sea water. The immersion process takes time about 72 hours. The properties of acoustics for each materials generally have high insertion loss (maximum found 25 dB), but some of them can reach low insertion loss (below 5 dB). The optimization of combination between structural and acoustic materials is promising to be investigated in near future to achieve the optimum properties of materials in terms of sound transparency.
The Effect Carbon Fiber Pole on Hand-Arm Vibration of Palm Fruit Motorised Cutter
Authors: Md Salleh Salihatun , Abd Kadir M.S. , Ramlee M.P. , Rahim Erween Abdul , Jelani Abdul Razak , Ahmad M.R. , Kasron Z.
Published: October 2014

Motorised cutter has been used in palm oil plantations and becomes an added value to improve its productivity during harvest. However, frequent use of the machine can cause damages to human hand arm and fingers caused by vibration. This paper presents a study on the hand arm vibration produced by a motorised cutter with pole 3 metres length. The objective of this study is to assess the safety of the machine to the users. The measurements involve taking vibration measurement at both grip of point 1 and point 2. These experiments involve two skilled users and two unskilled users which run in real palm oil plantation. The measurements are made according to ISO 5349,evaluation of hand arm was assessed from different angle of cutting, vibration values at both grip point and the standard limit exposure action A(8). Skilled user shows vibration exposed to less than 2.5m/s2 indicating safe condition of using the machine. The unskilled user shows vibration exposed to more than 2.5m/s2 indicating caution condition should be taken when handling the machine. From the data obtained, it is suggested to provide guidelines or training for any users so that less vibration transmission can be transferred to user when using this machine.
Design Flaw Enhanced by Improper Workmanship to Cause Fatigue Failure on Rotor Blade of Compressor Gas Turbine
Authors: Wiryolukito Slameto
Published: October 2014

Ten stages of Compressor Engine S/N 123 of X-Gas Turbine failed in service prior the schedule for overhaul at 40,000 hour. At the failure event the running hour was 29,600. The maintenance was normally done every 8000 hours including filter and gasket replacement, instrument re-calibration, and bore scope examination. Upon dismantling, it was found one blade at rotor stage #3 failed with facture surface strongly indicated a fatigue failure, defective on stator and rotor blades at downstream, no defective blades at upstream. Detail examination confirm Root Cause of failure on Compressor Blade of X-Gas Turbine were combination of a sharp radius of root chamfer as the major contributor and at lesser extent enhanced by “scratches” exist on root blade free surface. There was no evidences Foreign Objects or corrosion contributed to fail the compressor blades. Blade material was sound and did not contribute to fail the blade. The recommendations to avoid failure reoccurrences were all existing installed rotor blades shall be dismantled and examined for the existence of crack at their root area. Inspection on brand new blades for the existence of scratches on blade surface prior assembly shall be strongly imposed; blade with preexisting scratch shall be rejected. In a design stages, increase the sharp chamfer radius on blade root is worth-while to be analyzed further. Workmanship during blade assembly shall not develop any scratch on blade surface especially on its root surface. A procedure and schedule for inspection on the running blades shall be refined to be able to detect any crack on the operating blades; special attention shall be given on root area.
Numerical Study on Failure Process of Aluminium Plate Subjected to Normal Impact by Hemispherical Projectiles
Authors: Ibrahim M.N. , Siswanto Waluyo Adi , Zaidi Ahmad Mujahid Ahmad
Published: October 2014

In this paper a study is presented on the numerical analysis of the failure process of aluminium armour plate subjected to normal impact by hemispherical projectiles. The perforation process has been simulated by the application of 3D analysis using IMPACT dynamic FE program suite. The comparison on the elements size of meshing towards failure mode was observed and evaluated. The material behaviour of the target plate was approximated by an appropriate constitutive relation. The study covered different size of meshing element on target plate as well as different level of impact velocities. Different failure modes for each case were found. For low speed impact condition a petalling was observed, whereas for high speed impact a radial neck along with a holes enlargement was observed with better and uniform perforation mode. The deformation and failure mode of the impacted target plate will be given special attention in this investigation.
Optimization of Laser Cutting Parameters on the Laminated Carbon Fibre Reinforced Plastics (CFRP) Composites Using DOE Technique
Authors: Wahab Md. Saidin , Rahman Norzaina Abdul , Mohamed M.A.S. , Rahim Erween Abdul
Published: October 2014

Nowadays, carbon fiber reinforced plastics (CFRP) composites is widely used in the aerospace industry due to its excellent mechanical properties. In laser cutting process, high powers are used to cut materials then material melts and burns leaving edges with a high quality finish. To fulfill the high demand of cutting quality, a set of laser cutting parameters of CFRP material are studied. The objective of this experiment is to obtain an optimum laser cutting parameter thus minimizing the cutting defects particularly on kerf width at the top and bottom surfaces. The analysis of process parameter was carried out using DOE, Design Expert 6.0.8. Cutting speed, pulse duration, pulse repetition rate and pulse energy were analyzed at two levels. By the optimizing the parameter setting, significant improvement in cutting quality has been achieved.
Evaluation of Shear Strength of Concrete Beams with GFRP Reinforcement
Authors: Ali Imohamed , Abdul Samad Abdul Aziz , Mohamad Noridah , Al-Kafri Ghusen , Mohmmed Ahamad
Published: October 2014

This research presents an experimental study related to the shear behavior of simply supported reinforced concrete beams reinforced with Glass Fiber Reinforced Polymer (GFRP) bars. Four concrete beams reinforced with GFRP bars and four control concrete beams reinforced with steel bars were tested until failure. In order to realize the occurrence of shear failure, all tested beams were designed with longitudinal reinforcement only and without shear reinforcement. The test variables used in this study were the concrete strength, f'c, and longitudinal reinforcement ratio, ρ. The crack patterns, location of the diagonal crack and angle of the diagonal crack were also observed during the test. The shear design equations obtained from the codes and references were used to evaluate the data obtained from the test. Finally, based on the data obtained from experimental and theoretical analysis, comments and recommendation on the shear strength equations were suggested.
Hydrodynamic Characteristics of Flow around Tube Bank with Integral Wake Splitter
Authors: bin Md Seri Suzairin , bin Abdul Karim Zainal Ambri , bin Salleh Hamidon , Mohideen Batcha Mohd Faizal , Raghavan Vijay R.
Published: October 2014

This paper reports the effects of a longitudinal plate attached at the backward stagnation point of a bank of tubes on the local static pressure distribution. The longitudinal plate is termed as an integral wake splitter. Investigations on hydrodynamic characteristics of tube banks with integral wake splitter were carried out in cross flow of air in a rectangular duct at a Reynolds number of 15950. The integral wake splitter length-to-tube-diameter ratios studied were 0.5, 1.0, 1.5 and 2.0. The tube bank consisting of 12 rows and 3 tubes per row in equilateral triangular arrangement with a transverse pitch to diameter ratio, a = 2. The results obtained were compared to the experimental data of Seri et al. (2014). It is observed that the addition of the integral wake splitter reduces the overall pressure drop.
The Effect on the Application of Coolant and Ultrasonic Vibration Assisted Micro Milling on Machining Performance
Authors: Ibrahim Mohd Rasidi , Rahim E.A. , Ibrahim A.A. , Maskam N.A. , Ghani S.C.
Published: October 2014

Advancing of micro-milling process via ultrasonic vibration assist has been proven able to improve machining characteristics such as surface roughness quality and dimension accuracy. The improvement is due to the cutting motion of Vibration Assisted Machining (VAM) process. Thus, for every vibration motion manner, the cutting characteristic of the VAM system will be difference from one to another. This paper presents the development approach of ultrasonic vibration assisted micro-milling (UVAM) using tilted 45° XY stage. It covers theoretical perspective and the influence of Minimum Quantity Lubrication (MQL) system as cutting fluid. It will emphasize on the theory of surface roughness, dimension tolerance and cutting tool life. Piezo-actuator is used as fast servo vibration mechanism in specific axis input with controlled signal. The input signal is sine wave with controllable frequency and amplitude to allow mechanism control algorithms to be develop during the process. In addition, the effect of cutting fluid was be analyzed to understand the potential capabilities of this aid on UVAM process.
An Experimental Study of Heat Transfer Coefficient in a Bubble Flow throughout an Annulus Pipe Heated at Inner Wall
Authors: Sarjito Sarjito , Putro Sartono , Nugraha Nurmuntaha Agung
Published: October 2014

The aim of the research work describe in this paper is to investigate correlation of water, air massflow rate and calor fluks to heat transfer coefficient. The investigation was carried out toward a pipe section test developed from acrylic with diameter of 60 mm and 210 mm length, therefore, the buble can be easier to shoot. A concurrent water were flowed upward and air was injected from the bottom. The wall of the heater was heated using two thermocouple installed at the outer surfece of the heater. The fluid flow was measured using thermocouple installed along the annulus pipe. A heater with transparent tube diameter of 50 mm and 1800 mm length was also installed, and supplied with 1000 Watt electric power. Result of the experiment showed that heat transfer coefficient incresed along with the air massflow rate increased, and its decreased with the increasing of water mass flow rate. The maximum heat transfer coefficient of 4340,602 W/m2 °C at electric fluck calor of 29582,448 W/m2 was echieved on water volume flow rate of 3 lpm and 9 lpm of air volume rate.
A Parametric Study of Wind Catcher Model in a Typical System of Evaporative Cooling Tower Using CFD
Authors: Sarjito Sarjito , Riyadi Tri Widodo Besar
Published: October 2014

The aims of the research work described in this paper is a part were to use computational fluid dynamics (CFD) to investigate the factors affecting the performance of a single-stage downdraught evaporative cooling device for low-energy cooling of buildings developed from a novel prototype device described by Pearlmutter et al. (1996; 2008); and to model and explore the performance of the device when integrated within a hypothetical building. This involved carrying out simulations: to select the most effective wind catcher geometry. Two types of wind catcher using curved deflector and closed cowl design were studied: In total five alternative arrangements were investigated. Arrangements 1 and 2 were bi-directional wind catchers. Arrangement 1 was modelled without a baffle and arrangement 2 was modelled with an extended baffle. Arrangements 3, 4 and 5 were uni-directional closed cowls. Arrangement 3 was modelled without a baffle, arrangement 4 was modelled with a short baffle and arrangement 5 was modelled with an extended baffle and an increased inner radius of 1 metre which had the effect of raising the mid-plane height of the cowl inlet by 1 metre. Initially, for comparison in all studies, the inlet wind speed was set at 10 m/s at a reference height of 11.5 metres which corresponded to the mid plane height of the wind catcher and wind cowl entry ducts for arrangements 1 to 4. The CFD simulations were carried out to define the optimum geometry of a wind catcher.
Parametric Study on Anti-Vortex Film Cooling Hole Arrangements
Authors: Abdullah Mohammad Kamil , Aminnuddin Hazim Fadli , Mohammed Akmal Nizam
Published: October 2014

Film cooling has been extensively used to provide thermal protection for the external surface of the gas turbine blades. Numerous number of film cooling holes designs and arrangements have been introduced. The main motivation of these designs and arrangements are to reduce the lift-off effect cause by the counter rotating vortices (CRVP) produce by cylindrical cooling hole. One of the efforts is the introduction of newly found anti-vortex film cooling design. The present study focuses on anti-vortex holes arrangement consists of a main hole and pair of smaller holes. All three holes share a common inlet with the outlet of the smaller holes varies base on it relative position towards the main hole. Three anti-vortex holes arrangements have been considered; downstream anti-vortex hole arrangement (DAV), lateral anti-vortex hole arrangement (LAV), and upstream anti-vortex hole arrangement (UAV). In addition, a single hole (SH) film cooling has also been considered as the baseline. The investigation make used of ANSYS CFX software ver. 14. The investigations are made through Reynolds Average Navier Stokes analyses with the application of shear k-ε turbulence model. The results show that the anti-vortex designs produce significant improvement in term of film cooling effectiveness and distribution. The LAV arrangement shows the best film cooling effectiveness distribution among all considered cases and is consistent for all blowing ratios (BR). The results also unveil the formation of new vortex pair on both side of the primary hole CRVP. Interaction between the new vortices and the main CRVP structure reduce the lift off explaining the increased lateral film effectiveness.