bluuebunny/crossref_metadata_2025 huggingface dataset:
Influence of TiO2 on Selfclean Bio Coating
Authors: Sulong Nurulsaidatulsyida , Rus Anika Zafiah Mohd
Published: April 2013

Treatment on the exposed surface to the environmental attack was studied based on biopolymer coating from waste cooking oil doped with a superhydrophilic filler of Titanium Dioxide (TiO2), known as TOP. TOP was found to affect the physical properties of the coated concrete surface in a systematic way. Contact angle measurements are interpreted with respect to nanoand micro-features existing on the surface of the water repellent superhydrophilic filler filled bio-polymer composite coating. The smooth coated surfaces of polymer filled or doped with superhydrophobic filler shows the systematic increasing static Waste Contact Angle, WCA (θst) and revealed that polymer filled superhydrophobic fillers by only 2.0 % shows the ability to form superhydrophobicity property. Scanning Electron Microscope (SEM) pictures revealed the difference between the concrete surface roughness of concrete biopolymer with and without TOP coating is to provide self-cleaning concrete biopolymer coating based on two principal ways: (1) the development of surface coating of semiconducting photocatalytic superhydrophilic. (2) If such a superhydrophilic is illuminated by light, then grease, dirt and organic contaminants will be decomposed and can easily be swept away by rain.
Differential Ceramic Shell Thickness Evaluation for Direct Rapid Investment Casting
Authors: Omar M.F.M. , Sharif S. , Ibrahim Mustaffa , Idris Mohd Hasbullah , Fadzil A.S.A. , Amin Azriszul Mohd
Published: April 2013

Rapid prototyping (RP) process offers a promising economical way as a sacrificial pattern in investment casting (IC) at high speed and low cost for low volume part manufacturing. However direct sacrificial RP pattern have encountered shell cracking during burnout process due to polymer based materials. Shell mould thickness was need to be concerned to have strong enough to withstand RP part expansion for employing direct method. The aim of present research was to compare the efficacy of different shell thickness for aluminum casting part fabricated from acrylonitrile butadiene styrene (ABS) and acrylate based material made from FDM and MJM respectively. The hollow RP pattern has been used directly to produce ceramic moulds. The feasibility of ceramic mould has been assessed in term of burnout ability and crack defect. Dimensional accuracies and surface roughness of the castings part have been observed in this investigation. Result shows thicker mould with proposed stuco procedure resulted without any crack defect for botRP part and no residual ash remained when firing higher than 870°C of temperature.In addition, FDM produced better accuracy for overall mould thickness, but MJM have better surface roughness. Therefore both direct RP pattern were suitable to be used in IC process with proposed shell thickness.
Preliminary Fabrication of Polymer Membranes from Renewable Resources
Authors: Abd Rahim Rahimah , Rus Anika Zafiah Mohd , Bakhtiar Anis Suraya Ahmad
Published: April 2013

Polymer membranes from renewable material with controlled pore size and structure were produce using phase inversion technique. The optimal conditions for the preparation of polymer membranes was polymer concentrations in N,N-dimethylformamide (DMF) solution 12 % (w/v), 15 % (w/v), 18 % (w/v) and 21 % (w/v). This is due to the types of structure; pinhole-like structure and interconnected network structure. The structure of the membranes consisted of thick fibrill elements. The polymer membrane cross-section is composed of stacks of separate layers. Permeability of the polymer membranes obtained at lower concentrations, gives highest value of 0.161, 0.015, 0.001 and 0.00051 L/s.m3for 12 %, 15 %, 18 % and 21 % (w/v) respectively. Evidently, as the concentration of the polymer in DMF increases, the tear strength decreases. Meanwhile, for lower concentration in N,N-dimethylformamide (DMF), gave highest strength due to low membranes wall thicker. Thus, the membranes are easily break compared to the membranes that have high porosity as shown by tear test of 12 % with 21.8495 N/mm tear strength.
Numerical Investigation of 2-D Free Convection of Nanofluid in L-Shaped Enclosure
Authors: Sidik Nor Azwadi Che , Safdari Arman
Published: April 2013

This paper presents numerical investigations of the thermal and fluid flow behavior in an L-shaped of cavity filled with nanofluid. The left and bottom walls are heated to higher temperature than the horizontal upper and right vertical walls. The results show that the characteristic of flow and heat transfer are critically dependent on the dimensionless Rayleigh number. We also found that the presence of nanoparticle enhances the heat transfer rate in the enclosure.
Influence of Hot Compression Moulding of Biopolymer Filled Waste Granulate Biopolymer
Authors: Ghani M. Khairul Zaimy Abd , Rus Anika Zafiah Mohd
Published: April 2013

Bio-monomer based on original cooking oil was mixed with the hardeners with different percentages of Waste granulate Biopolymer (WB) fillers which is 30, 40, and 50 % equivalent to weight of monomer to produce Biopolymer filled Waste granulate Biopolymer (BWB) by using hot compress moulding. The tensile strength of BWB is 0.33, 0.45 and 0.43 MPa, meanwhile value of Youngs Modulus is 11.00, 8.18 and 5.06 MPa for loading 30, 40 and 50 % respectively. From the Scanning Electron Microscopy (SEM) micrograph, BWB has two characteristic and classified as a brittle and ductile fracture of granular (shiny) texture or cleavage character with little yielding before the sample breaks. Furthermore brittle fracture is characteristic by rapid crack propagation and then ductile fracture with stress whitening zone, appears fibrous appearance is dull and it have very rough surface. This fracture has glassy smooth surface, flat, bright, shiny and minimum deformation.
Performance and Emissions Characteristics of Diesel Engine Fuelled by Biodiesel Derived from Palm Oil
Authors: Khalid Amir , Osman Shahrul Azmir , Jaat M. Norrizam Mohamad , Mustaffa Norrizal , Basharie Siti Mariam , Manshoor Bukhari
Published: April 2013

Bio fuels based on vegetable oils offer the advantage being a sustainable, annually renewable source of automobile fuel. Despite years of improvement attempts, the key issue in using vegetable oil-based fuels is oxidation stability, stoichiometric point, bio-fuel composition, antioxidants on the degradation and much oxygen with comparing to diesel gas oil. Thus, the improvement of emissions exhausted from diesel engines fueled by biodiesel derived from palm oil is urgently required to meet the future stringent emission regulations. Purpose of this study is to explore how significant the effects of palm oil blending ratio on combustion process that strongly affects the vehicles performance and exhaust emissions. The engine speed was varied from 15003000 rpm, load test condition varied by Dynapack chassis dynamometer from 050% and palm oil blending ratio from 515vol% (B5B15). Increased blends of biodiesel ratio is found to enhance the combustion process, resulting in decreased the HC emissions with nearly equal of engine performance. The improvement of combustion process is expected to be strongly influenced by oxygenated fuel in biodiesel content.
Experimental Investigation of Mechanical Properties and Forming Capabilities in Thin Magnesium Sheet at Elevated Temperature
Authors: Soomro M. Waseem , Akhtar M. , Khan R. , Altaf S.
Published: April 2013

This paper investigates the mechanical properties and forming capabilities of magnesium ZE10. Mechanical properties are observed by stress strain diagram. Three types of the samples are used which are machined from thin sheets of 0.8mm thickness in 00, 450, 900 of the rolling direction (RD). The samples are then tested at different temperatures varying from room temperature (RT) to 400°C. The factors that are considered in tensile tests are Youngs modulus, Yield strength, Ultimate tensile strength and fracture strain. The later part of this paper is devoted to deep drawing tests in which specimen are drawn from room temperature to 250°C. In these tests variation of Limit Drawing Ratio (LDR) is investigated at different temperatures. The other parameters observed are drawing depth, punch force, blank holder force and their variation from room temperature to elevated temperature.
Experimental Investigations and Modeling of Machining Titanium Alloy – Ti-6Al-4V
Authors: Satyanarayana Kosaraju , Gopal Anne Venu , Babu Popuri Bangaru
Published: April 2013

The problem of machining titanium is one of ever-increasing magnitude due to its low thermal conductivity and work hardening characteristic of the titanium alloy. The efficient machining of titanium alloy with coated carbides involves a proper selection of process parameters to minimizing the surface roughness and cutting force. In the present work, experimental studies have been carried out to obtain the optimum conditions for machining titanium alloy. The effect of machining parameters such speed, feed and depth of cut on the cutting force, surface roughness were investigated. The significance of these parameters, on cutting force and surface roughness has been established using the analysis of variance. Mathematical models have also been developed for estimating the cutting force and surface roughness on the basis of experimental results.
Effect of Powder Loading and Binder Materials on Mechanical Properties in Iron-ABS Injection Molding Process
Authors: Sa'ude Nasuha , Ibrahim M. , Saidin Wahab
Published: April 2013

This paper presents the development of a new polymer matrix composite (PMC) feedstock material by the injection molding machine. The material consists of iron powder filled in an acrylonitrile butadiene styrene (ABS) and surfactant powder (binder) material. In this study, the effect of powder loading and binder content on the mechanical properties was investigated experimentally. The detailed formulations of compounding ratio by Brabender Mixer and injection molding machine of the sample specimen was used with various combinations of the new PMC material. Based on the result obtained, it was found that, higher powder loading of iron filler affected the hardness, tensile and flexural strength of PMC material. With 32% iron powder loading in ABS composites increase the flexural force, maximum stress and force of PMC material through an injection molding process.
Effect of Postweld Heat Treatment on the Mechanical Properties of Weld in a Medium Carbon Steel
Authors: Manladan S.M. , Onyekpe B.O.
Published: April 2013

This paper presents the result of an investigation of the effect of postweld heat treatment on the mechanical properties of weld in 0.36%C medium Carbon Steel. Samples were prepared and welded using Shielded Metal Arc Welding (SMAW) process with a low hydrogen electrode. The welded samples were subjected to postweld heat treatment (stress relief) at four different temperatures: 550°C, 600°C, 650°C and 700°C followed by air-cooling. Microstructural examination was carried out to determine the change in microstructure before and after postweld heat treatment. The mechanical properties of the samples were also tested before and after the heat treatment. It was established that a hard microstructure, susceptible to Hydrogen Induced Cracking (HIC), was formed in the heat affected zone of the as-welded samples and that postweld heat treatment improved the mechanical properties of the weld and substantially reduced or eliminated the risk of HIC.
Experimental Study on Ballistic Resistance of Sandwich Panel Protection Structure with Kenaf Foam as a Core Material against Small Arm Bullet
Authors: Zainol Abidin Mohamad Hafiz , Mohamad Mahmod Abd Hakim , Zaidi Ahmad Mujahid Ahmad , Wan Mat Wan Ali
Published: April 2013

This project is about an experimental impact resistance and behaviour of sandwich panel structure, consists of steel plates and kenaf foam. The use of natural fiber reinforcement foam could give a great advantages in weigh reduction which very useful in military mobility and transportability. A standard rifle was used to launch a small bullet (5.56 mm) in constant velocity towards the sandwich panels. The experiments result is based on the depth of the indentation due to the penetration against the armour. The best specimen combining both parameters of study is 20% of kenaf with 45 mm thickness because it can resists the most impact from the bullet. Therefore, it can be concluded that using kenaf to reinforce the polyurethane is success in enhancing its strength and mechanical properties.
Modelling and Simulation the Flexible Link in Water to Generate Dissolved Oxygen
Authors: Shah Muhammad Amir Mat , Md Zain Badrul Aisham
Published: April 2013

This paper presents the simulation of modeling a flexible link system that will be used as a new method to generate dissolved oxygen. This method is inverted as compared to other researches done in this field. The vibration generated from the movement of the flexible link will generate waves and bubbles in water thus generating dissolved oxygen. The results of the simulation are presented.
Evaluation of Parts Produced by a Novel Additive Manufacturing Process
Authors: Fahad Muhammad , Hopkinson Neil
Published: April 2013

Rapid prototyping refers to building three dimensional parts in a tool-less, layer by layer manner using the CAD geometry of the part. Additive Manufacturing (AM) is the name given to the application of rapid prototyping technologies to produce functional, end use items. Since AM is relatively new area of manufacturing processes, various processes are being developed and analyzed for their performance (mainly speed and accuracy). This paper deals with the design of a new benchmark part to analyze the flatness of parts produced on High Speed Sintering (HSS) which is a novel Additive Manufacturing process and is currently being developed at Loughborough University. The designed benchmark part comprised of various features such as cubes, holes, cylinders, spheres and cones on a flat base and the build material used for these parts was nylon 12 powder. Flatness and curvature of the base of these parts were measured using a coordinate measuring machine (CMM) and the results are discussed in relation to the operating parameters of the process.The result show changes in the flatness of part with the depth of part in the bed which is attributed to the thermal gradient within the build envelope during build.
Plane-Stress Analysis of the New Stress Tensor Decomposition
Authors: Mohd Nor Mohd Khir , Vignjevic Rade , Campbell James
Published: April 2013

The accuracy and reliability of the new stress tensor decomposition to capture the plasticity behaviour of orthotropic materials under plane-stress conditions was examined in this paper. No experiment was required to perform this work. Therefore, the suitable, published paper which provides a relevant test result and sufficient material properties to characterise the new stress tensor decomposition, was used. This new stress tensor decomposition was used to presents a new yield criterion for orthotropic sheet metals under plane-stress conditions in this work. This was done by assuming the yield surface to be circular in the new deviatoric plane. The predictions of the new effectice stress expression were then compared with the experimental data of 6000 series aluminium alloy sheet (A6XXX-T4) and Al-killed cold-rolled steel sheet SPCE. The predicted new yield surfaces are in good agreement with respect to the experimental data for two materials (A6XXX-T4 and SPCE).
The Effect of Optimum Number of Kanbans in just in Time Production System to Manufacturing Performance
Authors: Naufal Ahmad Adnan , Jaffar Ahmed , Noriah Yusoff , Halim Nurul Hayati Abdul
Published: April 2013

This paper discusses a method to determine optimum numbers of kanban in Just In Time production system and analyzes effect of optimum numbers of kanban to manufacturing performance. Method to determine kanban numbers was carried out by designing kanban flow based current situation, gathering relevant parameter on floor and company database, and calculating of kanban quantity through basic mathematical model. The basic mathematical model of kanban is derived according to designated kanban flow in JIT production system. The optimum number of kanbans would control and regulate material flow in manufacturing, thus JIT is achieved. As a result, product lead time and inventory stock level are improved. The conclusion is that an appropriate determination numbers of kanban could lead to optimizing manufacturing capability.
Wettability of Molten Sn-Zn-Bi Solder on Cu Substrate Ervina Efzan
Authors: Ervina Efzan M.N. , Tan S.Y.
Published: April 2013

This work presents the studies of wettability Sn-6Zn-4Bi lead-free solder alloy in electronic applications. A reference solder Sn-3.1Ag-0.9 Cu lead-free solder alloy is used to compare the properties of both solders. Differential Scanning Calorimeter (DSC) profile, wettability and the microstructure of the solder were investigated. The melting temperature of Sn-Zn-Bi (Tm=194.97°C) is lower than Sn-Ag-Cu (Tm=220.40°C). Further, the wettability between molten solder and copper substrate was measured at different reflow temperature. The contact angle for Sn-Ag-Cu was decreasing from 28.23º to 24.97º and for Sn-Zn-Bi solder alloys were decreasing from 48.92º to 29.78º as the temperature increased from 230°C to 250°C. A significant increment of contact angle for Sn-Zn-Bi at 270°C and the contact angle did not change at 270°C for Sn-Ag-Cu. The result of spreading area is inversed with the contact angle. The layers of intermetallic compound were examined by energy-dispersive X-ray. The Sn-Zn-Bi solder exhibits a mixture of Cu-Sn+Cu-Zn phase and ϒ-Cu5Zn8phase. The Sn-Ag-Cu solder exhibits Cu6Sn5 (η-phase) and Cu3Sn (ε-phase). As a conclusion, Sn-Zn-Bi is a potential lead-free solder to develop based on its wettability properties than previous available solder materials.
Vibration Analysis of Unbalanced and Misaligned Rotor System Using Laser Vibrometer
Authors: Masrol S.R. , Madlan M.A. , Md Salleh Salihatun , Ismon Maznan , Roslan Mohd Nazrul
Published: April 2013

Rotor unbalance and shaft misalignment are common major concerns in rotating system. In this study, vibration analysis for unbalanced rotor and misaligned shaft components using non-contact laser Doppler vibrometer (LDV) were examined. The vibration acceleration magnitude (m/s2) and FFT spectrum from the both fault detections were recorded by the portable laser Doppler vibrometer and analysed by the vibration analysis software. The result shows that combination of unbalance and parallel misalignment fault conditions can produce higher vibration thus reduce the life span of the rotor system. In this case, the unbalance fault condition combined with parallel misaligned rotor gave highest vibration magnitude followed by simply unbalanced rotor and parallel misalignment fault only. This experiment shows that the non-contact method has successfully detected the unbalance and parallel misalignment fault in the rotor system.
Lean Manufacturing Practices Implementation in Malaysian's SME Automotive Component Industry
Authors: Rose Ahmad Nasser Mohd , Deros Baba M. , Rahman Mohd Nizam A.
Published: April 2013

Due to global competition, automotive component industries are very keen to improve their manufacturing system as to fulfill car manufacturer demand. Currently, lean manufacturing (LM) system has become increasingly famous and popular among automotive component players. And, it was proven that lean manufacturing is the best manufacturing system in the 21st century. The main objective of this paper is to investigate the extent of 24 lean manufacturing practices implementation in SME. Secondly, to determine the possible barriers that could influence the process of lean manufacturing implementation. A survey questionnaire was developed to collect top and senior management judgement on 24 lean manufacturing practices and to rate the possible barriers during lean manufacturing implementation. Total completed questionnaires were 97 which represent 81.5% respond rate. The survey results show that a majority of respondents agreed and implementing extensively kaizen, 5S and standardization in their firms. Another finding was the four possible barriers that could influence the failure of lean manufacturing implementation which are employees resist to changes, unstable customer schedule, lack of knowledge and poor employee involvement.
The Novel Continues Biodiesel Proses Using Ultrasonic Clamp on Tubular Reactor
Authors: Soon Leong Boon , Rus Anika Zafiah Mohd , Hasan Sulaiman , Daim Ahmad Daud
Published: April 2013

This research is done to explore the advantage of ultrasonic clamp on tubular reactor as a new technology for the transesterification process of the vegetable oil by using the newly fabricated small biodiesel pilot plant. The following studies will analyze on the performance and the efficiency of the ultrasonic tubular reactor in its flow performance and the influence of the angle towards the flow rate which plays the role in the production. The low flow rate and reaction time will influence the cost of biodiesel process and by using ultrasonic, it helps the chemical reaction process to react faster hence contributing to less time consumption. In the research, the methanol to oil molar ratio will consists of 6:1, 9:1 and 12:1 respectively. Besides that, the percentage of catalyst concentration is 0.75 %, 1% and 1.25%. The fabricated small biodiesel pilot plant will be a part of knowledge on biodiesel process and its production.
The Effect of Drying Air Temperature and Humidity on the Drying Kinetic of Kenaf Core
Authors: Misha Suhaimi , Mat Ali Sohif , Ruslan Mohd Hafidz , Sopian Kamaruzzaman , Salleh Elias
Published: April 2013

Drying kinetics of kenaf core was investigated in a Low Temperature and Humidity Chamber Test. The drying experiments were carried out at temperature of 45, 50 and 55°C and air relative humidity of 10, 20 and 30% using a constant air velocity of 1.0 m/s. The moisture content data at various drying air conditions were converted to moisture ratio and plotted against time to obtain the drying curves for each experimental data. The curves were fitted to eight different thin layer drying models to determine a suitable model for drying of kenaf core. The fit quality of the models was evaluated based on their coefficient of determination (R2), reduced chi-square (χ2) and root mean square error (RMSE). Among the eight models, Two Term model is the best model for describing the drying behavior of kenaf core. The drying air temperature gave more significant effect on the drying kinetic of kenaf core compared to the drying air relative humidity under the experimental conditions studied.
Design and Analysis of a New Natural Illumination Device through Lumen Method Approach
Authors: Rahimah A.H. , Yuhazri M.Yaakob , Sihombing Haeryip , Adibah Razali
Published: April 2013

The design and development of a natural illumination device (NID) for Malaysian roofing system is explored and improved with the aid of Lumen Method Approach at the analysis stage. The aim of this research is to channel and distribute natural sunlight from exterior to interior building to enlighten the required space in a daytime. It is made up of three main parts; dome as light collector, light tube as light reflector and light diffuser as light distributor. The result shows illuminance level for the NID in full summer sun and overcast summer sun conditions are higher than T8 fluorescent lamp.
Effect of Process Parameters on Quality of Cold Spinned Tube Head
Authors: Wardoyo Toto Triantoro Budi , Izman S. , Kurniawan Denni
Published: April 2013

Metal spinning can be used to produce hollow, axially symmetric sheet metal parts with low tooling and production costs, high flexibility, and low waste. Spinning parameters determine the quality of the spinned parts and are of interest for enabling the spinning of thick sheet metals. In this study, conventional metal spinning was conducted on a 6 mm thick low carbon steel with process below its recrystallization temperature to fabricate tube head, requiring maximum deflection of about 90º at its edge. Spinning parameters varied were temperature (at room temperature and 300°C), feed (2 mm and 5 mm), and spinning speed (200 rpm and 250 rpm). Evaluation was made on the resulted surface morphology, thickness variation, and further analysis on hardness and microstructure of the spinned tube head. The resulted tube heads were of acceptable quality in terms of surface morphology and thickness variation, while hardness and microstructure analysis showed that inner parts of the workpiece were not affected by the spinning process.
Optimisation of Facility Layout Problem at Automotive Industry a Case Study in Sabah
Authors: Tan Kah Song , Mohd-Lair Noor Ajian , Nai-Vun Stephen Yong , Chau-Leong James Yong
Published: April 2013

The general Facility Layout Problem deals with the arrangement of machines within the facility based on the constraints such as material flow distance, volume of flow of products, material handling cost and operation sequence of product. The facility layout problem is directly linked with the efficiency of the facility or the manufacturing line. The objective of this project is to design a simulation based methodology experiment on designing an optimized facility layout and evaluating the proposed alternative layouts using ARENA simulation. This project is conducted at Benteng Motor Sdn. Bhd. in Kota Kinabalu, Sabah. Currently, the company is planning to expand their manufacturing plant and hence the company needs an optimized facility layout to maximize the product capacity and manufacturing throughput time on a minimum utilization of resources environment. An eight steps simulation methodology is being proposed to design an optimized facility layout. A manufacturing re-engineering scenario has been developed to improve the existing system. The proposed scenario was evaluated using Arena simulation student package. The scenario has significantly increases the production capacity up to 225%, decrease the manufacturing throughput time by 19% as well as increase the utilization of majority of the manufacturing resources more than 200%.
The Effect of Oil Supply Pressure on the Circumferential Pressure Profile in Hydrodynamic Journal Bearing
Authors: Ahmad Mohamad Ali , Kasolang Salmiah , Dwyer-Joyce Rob , Abdullah Nik Rosli
Published: April 2013

In hydrodynamic lubrication, the pressure condition of the fluid is critical to ensure good performance of the lubricated machine elements such as journal bearings. In the present study, an experimental work was conducted to determine the effect of oil supply pressure on pressure profile around the circumference of a journal bearing. A journal diameter of 100mm with a ½ length-to-diameter ratio was used. The oil supply pressure was set at three different values (0.3, 0.5, 0.7 Mpa) and the circumferential pressure results for 400, 600 and 800 RPM at different radial loads were obtained. It was observed that the maximum pressure values were affected by changes in oil supply pressure.
Mechanical Behavior of Polyurethane Composite Foams from Kenaf Fiber and Recycled Tire Rubber Particles
Authors: Subramaniyan S. Kanna , Mahzan Shahruddin , bin Ghazali Mohd Imran , Ismon Maznan , Zaidi Ahmad Mujahid Ahmad
Published: April 2013

In the present work polyurethane foams containing various content loadings of kenaf fiber and recycled tire rubber particulates were prepared and studied, with the objective of developing alternative composite rigid foams. The influence of the filler content on the foam microstructure and its physical and mechanical behavior has been studied for three different polyurethane resin densities. Microstructural observation on fracture surface of composites was carried out using scanning electron microscopy. It has shown closed spherical cells with reduced size when the fillers are added. Nevertheless, the incorporation of kenaf fiber and recycled tire rubber particulates that refined at 80 mesh led to higher mechanical properties than that unfilled polyurethane foam. A 6% filler content loading exhibited the optimum compression stress and compression modulus, while further increase of filler content loading resulted in decline in mechanical behavior. The presence of larger filler content deteriorated the polyurethane system cellular structure and lead to poor composites strength. Overall, the use of kenaf fiber and recycled tire rubber particulates gives composite foams with comparable mechanical behavior for the studied filler reinforcement level.
Computational Analysis of Mechanism Operability
Authors: Szweda Jan , Poruba Zdenek , Sikora Roman , Podešva Jiří
Published: April 2013

This article deals with a way of interpretation the results of numerical simulations solved for the mechanism of lifting platform. Subject of analysis is the atypical design solution of lifting mechanism with one degree of freedom, which members are connected by revolute joints and linear sliding guidance. The mechanism movement is provided by linear hydromotors. Computational simulations are carried out by FEM, where linear coupling equations are used for modeling of revolute joints and linear sliding guidance is modeled by structural contact of rail and slider. The way of modeling and parameters setting of structural contact significantly affects the stability of numerical solutions and the obtained results. The authors assume that the interpretation of the observed behavior and results of the numerical simulations allow to deduce the mechanism operability and gives a clue for setting the gap of real bounds.
The Effect of Wavy Groove Liner on Pressure Distribution of Journal Bearing
Authors: Asral Asral , Md Sheriff Jamaluddin , Osman Kahar
Published: April 2013

The ability of bearing liner to maintain the fluid film lubrication is crucial to its performance. This study is to investigate the pressure distribution for full film lubrication of wavy bearing liner. The results were compared to that from smooth bearing liner. These bearings were used with the palm oil based lubricant. CFD analysis was developed to determine the numerical data. A 60 mm bearing with ratio 0.5 of its diameter to length is simulated. This bearing has 250 µm in clearance and 200 µm in amplitude with semi rectangular circumferential surface waviness liner in shape. Pressure distribution of the bearing was influenced by the increment of the eccentricity ratio and the speed of shaft. The surface waviness liner bearing produces higher in pressure by comparing it with the smooth bearing. The maximum pressure was noted in the vicinity of minimum fluid film thickness where it was distributed at the area around the peak of wave.
Effectiveness of Enterprise Resource Planning System in Supporting the Lean Manufacturing
Authors: Kong Pang Chee , Daud Yusof
Published: April 2013

Enterprise Resource Planning (ERP) system is integrated software that linked the functional areas in the organization by using and sharing the database in one platform. The implementation of ERP system in most of the manufacturing plants help in simplifying the production and scheduling system and smoothing the process flow which will lead the organisation towards lean manufacturing environment. Most of the manufacturers do not analyse and review on the effectiveness and implications of the ERP system at the post implementation stage. This study was established to address the impacts of the ERP system in leveraging the lean practices at the shop floor and the recommendations for the continuous improvement initiatives. Data for analysis has been retrieved from in house ERP system and from manual record system of a company that already implemented ERP system. Questionnaires have been distributed to ERP users within Malaysia and Singapore to gain insight the related issue of using ERP system in their company. The study provides evidence on the effectiveness and positive impacts of the ERP system to support manufacturing industries to become more lean and agile. ERP system also effectively to response to the customer requirement and added the value along the supply chain.
Effects of Mig Welding to Corrosion Behaviour of Carbon Steel
Authors: Razak Nur Azhani Abd , Ng Wai Loon , Juliawati A.
Published: April 2013

This paper presents corrosion behaviour of welded low carbon steel at different welding parameters. Welding process was conducted using metal inert gas (MIG) technique at welding voltage range of 19 to 22 V with 1 V interval, and wire feed rate range of 90 to 120 inch per minute (ipm) with 10 ipm interval. Filler material used was ER 70S-6 with 1.2 mm diameter. Corrosion behaviour of welded carbon steel was tested using synthetic seawater environment with 3.5 wt% NaCl. Microstructure changes and penetration level of weldments were observed using scanning electron microscope (SEM). Results showed that, corrosion rate decreased when the welding voltage and wire feed rate increased with full penetration level of weldment attainment. The lowest corrosion rate occurred at the highest welding voltage and wire feed rate when full penetration of weldment occurred. From metallographic study, iron oxides and pitting was found on the surface of the exposed area after the corrosion test.
Experimental Study on the Effect of Different Speeds Applied with Palm Olein Using Pin-on-Disk Tester
Authors: Izhan M.I. , Wira Jazair Yahya , Kadir Mohammed Rafiq Abdul , Syahrullail Samion
Published: April 2013

The wide use of conventional lubricants causes pollution to the environment and the rising awareness on green house effect has triggered the use of environmental friendly and biodegradable lubricants in the industries. Palm olein was selected to be a candidate due to its superior tribological properties and large production in country. In the research, the behavior of palm olein characteristic was investigated by using pin-on-disk experiment in which the pin was loaded against the rotating grooved disk. The experiments by sliding were performed via pin on disk tester using stainless steel as the material for both flat ended pin and grooved disk. The test were carried out by dropping 5 ml of palm olein as lubricant on the sliding surface at two different speeds which were 0.25 and 1 m/s. In this study, the wear rate of the pin and friction coefficient was investigated. The weight loss and surface roughness before and after experiment were analyzed. All the results obtained were compared to hydraulic oil and paraffinic mineral oil. From the analysis, friction coefficient acquired with lubrication of palm olein was the lowest for both conditions, while the wear rate obtained also showed a similar trend. The pin lubricated with palm show the lowest result of wear rate and weight loss.
Experimental Study of Oil Supply Pressure Effects on Bearing Friction in Hydrodynamic Lubrication
Authors: Ahmad Mohamad Ali , Kasolang Salmiah , Dwyer-Joyce Rob
Published: April 2013

Journal bearing is widely applied in most of rotating machineries for transmission of large loads at mean speed of rotation. Friction caused by the shearing condition between journal, bearing and lubricant contribute to power loses in journal bearing system. In the present study, an experimental work was conducted to determine the effect of oil supply pressure on frictional force, friction coefficient and torque of a journal bearing. A journal diameter of 100 mm with a ½ length-to-diameter ratio was used. The oil supply pressure was set at three different values (0.3, 0.5, 0.7 MPa). Frictional force and friction coefficient results for 400, 600 and 800 RPM at different radial loads were obtained. It was observed that the change in oil supply pressure has affected the fluid frictional force and friction coefficient to some extent.
Influence of Zr/Sn Ratio Electric Properties of PLZST Ceramic
Authors: Wang Jin Fei , Yang Tong Qing , Wei K. , Li G. , Li Yong Xiang
Published: April 2013

(Pb0.97La0.02)(Zr0.92-xSnxTi0.08)O3 (PLZST) ferroelectric ceramics with x=0.40, 0.25, 0.15, respectively, were investigated. It was found that these ceramics with different Zr:Sn ratios were perovskite structure. With increasing of Zr:Sn ratio, the phase-transition electric-field of antiferroelectric to ferroelectric phase increased. when x>0.15,All the samples have double hysteresis loops with antiferroelectric phase characteristics. Yet, when the electric field was removed at lower temperature of -5oC and -20oC, for x=0.25 and 0.40, the electric field induced FE phase can remain metastable FE state. But for x=0.15, the induced FE phase recover to AFE phase even at -20oC. Yet, electric field induced FE phase exist as metastable FE phase. TFE-AFE of the samples was -5oC, -20oC, when x=0.40, x=0.25, respectively. With increasing of Zr:Sn ratio, TFE-AFE increaseddecreased, Tc was hardly changed, but the dielectric constant increased from ~2500 to ~6000, the peak changed sharply, dielectric loss increased continuously with increasing of Zr:Sn ratio.
Production of BaTiO2 Nanocrystalline Powders by High Energy Milling and Piezoelectric Properties of Corresponding Ceramics
Authors: Chandramani Singh K. , Jiten Chongtham
Published: April 2013

Barium titanate (BaTiO3 or BT) has become one of the most studied functional materials due to its potential application as multilayer ceramic capacitors, PTC thermistors, electromechanical devices, piezoelectric transducers, actuators, dynamic RAM or logic circuitry as well as a great variety of electro-optical devices. In the present study, high energy ball milling has been used to produce nanocrystalline powders of BT. Two categories of powders having average particle size of 35 nm and 25 nm were prepared by setting the milling speed at 250 rpm and 300 rpm respectively, fixing the milling time at 30 hours. Four ceramic samples, BT35-1350, BT25-1350, BT35-1400 and BT25-1400, were formed by sintering the two types of powders at 1350oC and 1400oC for 3 hours. The ferroelectric and piezoelectric properties of the ceramic samples were studied and found to be dependent on the size of the starting nanopowders. The bulk density and piezoelectric constant (d33) of B25-1350 were found to be less than those of BT35-1350, while the reverse was true in case of BT25-1400 and BT35-1400. Well saturated P-E hysteresis loops were observed for all the ceramics with the size and shape of the loops appearing different for the four samples. For both the pairs of ceramics sintered at 1350oC and 1400oC, the remnant polarization (Pr) decreases with starting particle size, that is, as we go from BT35-1350 to BT25-1350 as well as from BT35-1400 to BT25-1400. However, with decreasing particle size of the starting powders, the coercive field (Ec) increases for the ceramics sintered at 1350oC and decreases for the ceramics sintered at 1400oC. The study reveals the importance of an optimized combination of the size of the starting nanopowders and sintering temperature for obtaining BT ceramics with the desired properties.
Properties of Optical Quantum Transition of GaN and CdS In Electron Deformation Potential Phonon Interacting Qusi-Two Dimensional System under Two Circularly Oscillating Fields
Authors: Lee S.H. , Sug J.Y. , Park J.H.
Published: April 2013

We study optical quantum transition line shapes (QTRSs) and optical quantum transition line widths (QTLWs) in relation to magnetic-field dependence properties of the electron-deformation potential phonon interaction system. We consider two systems - one is subject to right circularly oscillating external fields and the other is subject to left circularly oscillatory external fields. The main purpose of this work is to compare QTLSs, which indicate absorption power, in the two oscillating external fields. Our results indicate that the QTLSs of right circularly oscillating external fields is larger than the QTLSs of left circularly oscillating external fields, while the opposite result is obtained for the QTLWs. Through the analysis of this work , we found the increasing properties of QTLW and QTLS of GaN and CdS with the temperature and the magnetic fields. We also found the dominant scattering processes are the phonon emission transition process.(PACS: 72.10.Bg,72.10.Di)
Effect of Chemical Reaction Temperature on Magnetic Properties of Cu2+ Substituted NiZn Ferrites
Authors: Shinde Neelam S. , Khot Sujata. S. , More R.M. , Watawe Shrikant C.
Published: April 2013

Ni-Cu-Zn ferrites with general formula Ni0.5Cux/2Zn0.5-x/2Fe2O4 (with x = 0.3, 0.4, 0.5 and 0.6) have been synthesized using oxalate precursor method with different precursor reaction temperatures in the range 100C to 700C. The structural analysis has been carried out using X-ray diffraction studies which reveal the formation of ferrites structure. The lattice parameters obtained using the most intense 311 peak are found to be in the range 8.37 to 8.42 Å for all the samples. The saturation magnetization is found to be in the range 20 to 51 emu/g, while the magnetic moment is found to be in the range 0.63 to 1.5 µB. The magnetic losses were found to be maximum for the samples obtained at precursor reaction temperature of 350C. The grain size is found to be in the range 0.4 to 2.0 µm. There is variation in the magnetic properties for different precursor temperatures indicating the effect of reaction history on the various parameters studied.
Optical Properties of ZnO Nanowires Decorated with Au Nanoparticles
Authors: Sakurai Makoto , Liu Ke Wei , Ceolato Romain , Aono Masakazu
Published: April 2013

One of the key technologies in future optoelectronics is control of excitons in oxide materials by the coupling with plasmons on noble metal surfaces. Optical properties of ZnO nanowires decorated with Au nanoparticles were studied to understand fundamental mechanism of the coupling and to develop optoelectronic devices with new functionalities. Light intensity at the main peak position in the photoluminescence (PL) spectra of ZnO nanowires was enhanced with the coverage of Au nanoparticles. Lifetime of excitons excited optically decreased by the decoration of Au nanoparticles. Understanding of the coupling between excitons and plasmons leads to optical control of excitons and will pave the way for new type of optoelectronic devices.
Exploration for Soapstone Occurrences: Use of Bulk Chemical Analyses to Select Potential Formation Areas
Authors: Leinonen Seppo
Published: April 2013

Soapstone is a talc and carbonate containing metamorphic ultramafic rock commonly found in greenschist-amphibolite facies greenstone belts. The regional metamorphism and shear zones as pathways for CO2 containing water fluids are interpreted to have been essential to the formation of soapstone. In spite of the supposed uniform metamorphic conditions favourable to talc-carbonate soapstone, also unaltered serpentinites are usually found in the same location areas and deposits. The objective of this study is to define the bulk chemical response of ultramafic rocks to form soapstone in hydration-carbonation metamorphic processes. Thermodynamic calculations and pseudosection modelling indicate that soapstone is most likely to occur in high silica low magnesium ultramafic sequences, because they turn to talc-carbonate even with very low CO2 content of metamorphic fluids. This is a new approach to classify and locate potential deposit areas in soapstone exploration.
An Investigation of Colour Properties of Orosei Limestones (Italy) by Using Computer Program
Authors: Akkoyun Ozgur , Careddu Nicola , Marras Graziella
Published: April 2013

In this study, a new computer program developed to determine the colour properties of natural stone products is introduced. The program can scan any digitalised picture of natural stone products and produce several statistical results such as mean, variance, minimum and maximum colour values, skewness and kurtosis values of the colour histogram, energy, contrast, entropy and homogeneity values of the data which may be used to classify the typology and/or quality of natural stone products. As a case study, Orosei limestones (Sardegna, Italy) were used. There are several typologies of Orosei limestones such as Nuvolato (Cloudy), Venato chiaro (Light veined), Venato medio (Medium veined), Venato scuro (Dark veined), Perlato chiaro (Light pearled), Perlato medio (Medium pearled) and Perlato scuro (Dark pearled). The remarkable results produced by the program are presented.
Rock Alteration and its Relation to Surface Finishing
Authors: Silva Zenaide Carvalho G. , da Cruz Joana M.M.
Published: April 2013

Rock finishing is a valuable tool used by architects to improve contrasts in decoration pattern in walls or building façades as they exhibit textures and color differences on their surfaces according to the type of finishing. When exposed to aggressive environment, these finishing impose different rate of alteration in the rocks as their ability to absorb humidity is also different for each type of finishing. Special types of silicate rocks underwent experiments in order to test their response to salt fog atmosphere. The study was centered on surface aspects of polished and honed finishing and their mass loss during seven salt fog cycles. All rocks studied are identified in the rock industry as granites although some are differently classified according to their petrography. They are: Blue Bahia, Belfast, Amazonite, Baltic Brown, Imperial Brown and Blue Labrador “Granites”. Each one has a particular feature to justify its inclusion in the study, as texture, mineral composition or specific occurrence and mineral association.
Characterization of "Xisto" as a Way to Promote its Use as Natural Stone
Authors: Noronha Fernando , Carvalho Cristina , Aires Silvia , Casal Moura Antonio , Farinha Ramos Joao
Published: April 2013

The main objective of this work was to contribute to the knowledge of the geological resources of Trás-os-Montes and Alto Douro (TMAD) region, in particular of its “Xisto” (Portuguese word for “schist”, lato sensum), considering its economic and social impact. The target area is characterized by the abundant occurrence of different types of “schist”, belonging to the Variscan basement. This work is a contribution to improve the knowledge about mineralogy, fabric, chemistry and technology of the “schist”, in order to promote its exploitation and use as a natural stone. It was possible to identify the main factors that have an influence on the characteristics of all types of “schist”, conditioning its use as natural stone.
Comparison of Young’s Moduli of Engineered Stones Using Different Test Methods
Authors: dos Santos João P. Lam , Amaral Pedro M. , Diogo António Correia , Rosa Luís Guerra
Published: April 2013

This work reports the results of Young’s modulus of elasticity obtained for 3 types of engineered stones. Using parallelepiped specimens with dimensions 150  30  20 mm3, Young’s modulus is determined by different methods: static and dynamic. Via quasi-static deformation tests: - uniaxial tension, - uniaxial compression, and, - pure bending (i.e. symmetrical four-point bending), determination of Young’s modulus was carried out by means of the conventional electric-resistance extensometry with strain-gauge strips glued to the specimens. The results obtained from these quasi-static deformation tests are compared with the results of dynamic Young’s modulus obtained with RFDA equipment (Resonant Frequency & Damping Analyser) using the parallelepiped specimens in a flexural vibration mode. Dynamic Young’s modulus was also evaluated through measurements of ultrasonic pulses velocity. Composition and microstructures of the materials under investigation are also presented and discussed.