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Articles by S. Abdullah
Total Records ( 28 ) for S. Abdullah
  M.M. Rahman , A.K. Ariffin , S. Abdullah , M.M. Noor and Rosli A. B
  This research presents the durability assessment of cylinder block for a two-stroke free piston engine using narrow band approach. The life prediction results are worthy for improving the component design at the very early developing stage. This approach is adequate for periodic loading, however, requires very large time records to accurately describe random loading processes. Fatigue damage in conventionally determined from time signals of the loading, frequently in the form of stress and strain. However, there are scenarios when a spectral form of loading is more appropriate. In this case the loading is defined in terms of its magnitude at different frequencies in the form of a Power Spectral Density (PSD) plot. The vibration fatigue calculation can be utilized where the random loading and response are categorized using power spectral density functions and the dynamic structure is modeled as a linear transfer function. This research also investigates the effect of the mean stress on the fatigue life prediction using the random loading. The acquired results indicate that the Goodman mean stress correction method gives the most conservative results with the Gerber and no (zero) mean stress method. It is observed that the compressive mean stresses are beneficial while the tensile mean stresses are detrimental to the fatigue life. The proposed technique is capable of determining premature products failure phenomena. Therefore, this technique is able to reduce cost, time to market, improve the product reliability and finally the user confidence.
  S. Abdullah , C.K.E. Nizwan and M.Z. Nuawi
  This study presents the development of the STFT-based fatigue data editing technique that will be used as a tool to accelerate for accelerating fatigue testing. This technique was performed by removing low amplitude cycles contained in the original signal in order to produce a shortened signal using the Short-Time Fourier Transform (STFT) parameter. The effectiveness of STFT power spectrum was validated using an SAE random fatigue data in order to indicate the relationship between STFT parameter and fatigue damage. The data was separated into two segments, i.e., damage and non-damage segments based on the 100% retention of the original fatigue damage. For the editing process, the STFT power spectrum distribution was used as the parameter to identify the damaged segment according to the power spectrum Cut-Off Level (COL). The low amplitude cycles with power spectrum lower than COL value were then removed from the original signal. Thus, a new edited signal was obtained which has retained almost 100% of the original fatigue damage and has equivalent signal statistic. The edited signal was found to be approximately 84% of the time duration of the original signal.
  M.M. Rahman , A.K. Ariffin , S. Abdullah , M.M. Noor , Rosli A. Bakar and M. A. Maleque

Objectives: This study was focused on the finite element techniques to investigate the effect of surface treatment on the fatigue life of the vibrating cylinder block for new two-stroke free piston engine using random loading conditions.
An understanding of the effects related to the random loading is necessary to improve the ability of designers to accurately predict the fatigue behavior of the components in service. An internal combustion engine cylinder block is a high volume production component subjected to random loading.
Problem statement:
Proper optimization of this component that is critical to the engine fuel efficiency and more robustly pursued by the automotive industry in recent years. A detailed understanding of the applied loads and resulting stresses under in-service conditions is demanded.
The finite element modeling and analysis were performed utilizing the computer aided design and finite element analysis codes respectively. In addition, the fatigue life prediction was carried out using finite element based fatigue analysis code. Aluminum alloys were considered as typical materials in this study.
Results: The frequency response approach was applied to predict the fatigue life of cylinder block using different load histories. Based on the finite element results, it was observed that the fatigue life was significantly influenced for the nitriding treatment. The obtained results were indicated that the nitrided treatment produces longest life for all loading conditions.
Conclusion: The nitriding process is one of the promising surface treatments to increase the fatigue life for aluminum alloys linear engine cylinder block.

  S. Abdullah , M.F. Abdullah , A.K. Ariffin and A. Jalar
  The copper-based leadframe is practically proven effective in the thermal and reliability of a Quad Flat No Lead (QFN) three dimension (3D) stacked-die semiconductor package. Reducing the copper thickness is understood to present various thermal and reliability failure mode and mechanisms, such as die cracking and delamination. However, no in-depth study has been pursued in order to determine the capability of achieving the product requirements in terms of thermal and reliability in a 3D stacked-die package. The drive towards a Die-Free Package Cost (DFPC) reduction has led the authors to study the used of a thin leadframe in a QFN 3D stacked-die. Hence, the work presents basis for the qualification of a thin leadframe design and also to demonstrate the thermal and reliability performance. Finally, an extensive virtual thermal-mechanical prototyping has to be achieved in order to understand the physics of materials during the assembly and reliability testing of a 3D stacked-die package with a thin leadframe. This design rule was found to be developed in order to prevent a die crack occurrence between die and leadframe in the semiconductor package.
  D.A. Wahab , N.F. Adull Manan , M.A. Hannan , S. Abdullah and A. Hussain
  Today, intelligent safety systems are installed in modern cars in view of minimising road hazards. An intelligent air bag system for example, comprised several subsystems that are integrated to include the weight sensor system, image sensor system, crash sensor system and tyre pressure monitoring system. These systems when poorly positioned into the car seat, will certainly affect comfort and reliability of the car seat. This research presents the design work on an intelligent car seat, which is equipped with a load cell type-sensory system. The load cells are used to detect the weight of a passenger for the deployment of an air bag system. The proposed design is validated against displacement and stress analysis using an 80 kg load to simulate the weight of a passenger. Results from the design validation indicated that the proposed configuration and material is appropriate for use in the intelligent car seat application.
  M.F. Rosle , I. Abdullah , S. Abdullah , M.A.A. Hamid , A.R. Daud and A. Jalar
  Problem statement: Repeated heat cure during assembly processes affected the Die Attach Film (DAF) material properties and the effectiveness touched area that leads to weak die bonding and delamination. Suitable die attached condition and DAF material selection had been evaluated to achieve required reliability performance in the manufacturing of the 3D Quad Flat No-Lead (QFN) stacked die package. Approach: During this study, special attention was given to the development of the residual stresses due to mismatch in the coefficients of thermal expansion of different DAF materials. Both experimental and finite element method were employed to gain a better understanding in a stress development induced between two different type of DAF, different die attach temperature and during the manufacturing process. Differential Scanning Calorimetry (DSC) was used to measure the changes of heat flow characteristics for both types of DAF. The die bond strength results measured using shear testing machine were compared with the finite element method prediction. Results: Although both DAF samples achieved good reliability performance and passed the Moisture Sensitivity Level 3 test (MSL3) at reflow 260°C without any sign of delamination, numerical simulation had demonstrated that the stress development were increased exponentially as the die attach temperature increased. It showed that different DAF gave different values of stresses but presented the same trend which the lowest die attached temperature (100°C in comparison with 125°C and 150°C) gave more stress to the die and possibility that the die will have weak adhesion to the substrate was high. Conclusions/Recommendations: Therefore for this case, stress can be relieved by having higher die attached temperature with an adequate bonding force and time, however die attached temperature for both DAF must be used above the glass transition temperature (128°C for DAF A and 165°C for DAF B) and being controlled not to exceed the crystallization temperature (203°C for DAF A and 204°C for DAF B) of both DAF.
  M. Abdullah , A.F.M. Zain , Y.H. Ho and S. Abdullah
  Problem Statement: Ionospheric scintillations, which cause significant effects on satellite signals for communication and navigation, often takes place in equatorial region such as Malaysia. However, this disturbance is not fully understood due to few studies performed. This research reports the study and monitoring activity on Total Electron Content (TEC) and ionospheric scintillation in Malaysia using GPS measurements. Approach: One dual-frequency GPS receiver was positioned at the main station in Parit Raja, West Malaysia (1.86° N, 103.8° E) and Sipitang, East Malaysia (5.10° N, 115.56° E) respectively. Dual-frequency GPS data collected during the one-month ionospheric experimental campaign was used for TEC and scintillation computation and analysis. The TEC with 15 sec interval were computed from combined L1 and L2 code-pseudorange and carrier phase measurements. Whereas, the scintillation parameter S4 index was computed as a standard deviation of the received signal power normalized to average signal power every 60 sec on L1. A corrected S4 (without noise effects) was also computed and used in the analysis. Results: It was found that the daily maxima vTEC for Parit Raja (PR) ranged from 38-100 TECU, which is generally higher than those of Sipitang, which ranged from 30-42 TECU. However, a general consistency for both stations can be seen during the 1 month campaign period. Conclusions/Recommendations: In conclusion, these results show good agreement in the existence of the equatorial anomaly observed during moderate solar flux conditions and undisturbed geomagnetic condition. This will contributes to the knowledge of equatorial ionosphere and help in space weather condition. However, to better understand and characterize the ionosphere over Malaysia, more campaigns should be encouraged.
  Layth H. Jawad , S. Abdullah , R. Zulkifli and W.M.F.W. Mahmood
  In order to increase the performance of the conventional turbocharger compressor’s to boost the pressure into engine. The flow inside a small centrifugal compressor with both single and modified double splitters used as an automotive turbocharger was simulated. Further, the performance of the centrifugal compressor depended on the flow in the impeller and splitters, but the splitters were not continued to the leading edge. If the splitters continued to the leading edge, it would produce sufficient blockage to cause choking at high speed. This research aimed to study and simulate the effect of double splitters on the performance of a turbocharger compressor. The simulation was undertaken using Computational Fluid Dynamics (CFD) analyses on aerodynamic flow field and to predict the mass flow rate and aerodynamic characteristics. The mesh generator of CFD Code was used to generate a polyhedron mesh. According to the results of the simulation, the outlet mass flow rate for a specific speed increased for the compressor with double splitters and all the performance characteristics also increased. It was observed that the turbocharger compressor performance was heavily affected by the impeller design.
  S. Abdullah , M.H. Selamat , Z.C. Cob and U.S. Sazaly
  In this study, we proposed a framework for measuring knowledge transfer process in e-learning environment. This framework provides an element that covers all aspects to better evaluate the KTP and e-learning and provide a better description in explaining issues of effectiveness. We set up questionnaires to survey users of E-Faculty (e-learning system developed by FSKTM, UPM) and make a descriptive and inferential analysis for better findings on measurement attributes and correlation between hypothesis and testing result. We conclude that our framework provide a proper guideline to conduct evaluation on determining the effectiveness of process in e-learning.
  S. Abdullah , S.N. Sahadan , M.Z. Nuawi and Z.M. Nopiah
  This study explores an application of the wavelet denoising technique in a fatigue road load variable amplitude data set. In this study, the wavelet denoising application has been implemented using the 4th order of Daubechies family, with the adaptation of fifteen levels decomposition process. From the view of current research trend, the wavelet-based denoising approach is widely used using vibration random signal, but it is rarely been used in the scope of fatigue road loadings, or also known as fatigue strain signals. The idea of this study came from the some previous vibration analysis research and it was found to be suited to the approach of fatigue signal denoising process. High amplitude events in a fatigue road signal are very important and they should be retained because of these features caused significant damage of the components, particularly in automotive applications. After the fatigue signal has been denoised, the global signal statistical calculation and fatigue damage/life analysis were performed in order to validate the applicability of this denoising technique. From the analysis, it was found that the wavelet denoising approach was not suitable to analyse fatigue data and the major concern is the omission of high amplitude events from the original road loading, hence to a significant fatigue damage difference when compared to the edited road loading.
  S. Abdullah , N.A. Al-Asady , A.K. Ariffin and M.M. Rahman
  This research describes the majority of interesting findings in the use of the Finite Element Analysis (FEA) based fatigue for automotive components in a form of review write-up. Thus, the theoretical background related to the fatigue life prediction using FEA is presented which is the main subject of this research. The challenge for FEA-based software developers is to deliver reliable fatigue-analysis tools because over designing components is no longer a viable option. Combination between a fatigue model based on the crack initiation, the crack growth and the crack closures are performed with consideration of cycle sequence effect together with finite element results, which lead to the prediction of fatigue life under spectrum or service loadings.
  S. Abdullah , M. Loman and N. Jamaluddin
  This study focuses on the assessment of fatigue damage in a piping system. Strain loading data was acquired using the fatigue data acquisition devices on a lab scale piping system. Specifically, the data was measured on the roughened and smooth pipe surfaces simultaneously, where the strain gauges were mounted on both of the piping surfaces. In this study, three different water flow rates were operated in the experiments which were normal, maximum and variable. The normal water flow rate was assumed as the reference flow rate for the subsequent fatigue analysis. The recorded strain signal was then analyzed using the frequency and time-frequency method and the short-time Fourier transform was applied to explain the fatigue damage events. The fatigue data from the experiment was employed to calculate the fatigue damage of the piping system.
  M.M. Rahman , A.K. Ariffin , N. Jamaludin , S. Abdullah and M.M. Noor
  This study presents the finite element based fatigue life prediction of a new free piston linear generator engine mounting. The objective of this research is to assess the critical fatigue locations on the component due to loading conditions. The effects of mean stress and probabilistic nature on the fatigue life are also investigated. Materials SAE 1045-450-QT and SAE 1045-595-QT are considered in this study. The finite element modeling and analysis was performed using computer-aided design and finite element analysis codes. In addition, the fatigue life prediction was carried out utilizing the finite element based fatigue code. Total-life approach and crack initiation approach were applied to predict the fatigue life of the free piston linear engine mounting. The results show the contour plots of fatigue life and damage histogram at the most damaging case. The comparison between the total-life approach and crack initiation approach were investigated. From the results, it can be concluded that Morrow mean stress correction method gives the most conservative (less life) results for crack initiation method. It can be seen that SAE 1045-595-QT material gives consistently higher life than SAE 1045-450-QT material for all loading conditions for both methods.
  S. Abdullah , S.M. Beden , A.K. Ariffin and M.M. Rahman
  This study presents an analysis technique to asses the fatigue life of a shell structure under variable amplitude loadings (VAL). For this purpose, the finite element analysis technique was used for the simulation works. The life prediction results are useful for improving the component design methodology at the early developing stage especially for shell structures such as a pressure vessels or pipelines analysis. The fatigue life prediction was performed using the finite element based fatigue analysis codes. In addition the ability of stress-life (S-N) and strain-life (ε-N) approaches to correlate and predict life are examined according to the different damage and failure rules. Numerical life prediction results (S-N and ε-N) of shells under VAL, as well as Constant Amplitude Loading (CAL) are presented and discussed. The effect of the mean stress, surface finish and the shell thickness are studied and discussed as apart of the interactions between geometries, loadings and materials. The simulation results showed that more studies on the shell structure need to be performed in order to obtain more accurate fatigue life.
  T.E. Putra , S. Abdullah , M.Z. Nuawi and Z.M. Nopiah
  An extraction computational algorithm for fatigue feature editing is presented in this study. The magnitude of the time domain Morlet wavelet coefficient level was used as the parameter to set gate value for the eliminating process of the 60 sec original signal. It was important to maintain the signal statistical parameters and the total fatigue damage of the mission signal as close as to the original signal, with the retention of the original load sequences. At the end of the process, by using this approach, segments containing the higher Morlet wavelet coefficients that contribute to the more fatigue damaging events were retained and were then joined so produce the optimum mission signal length of 13.8 sec. This short signal gave a 77% reduction in length with only 8.7% reduction in the fatigue damage. In conclusion, the extraction of the fatigue features using the Morlet wavelet successfully created a new mission signal which retains the majority of the higher fatigue damaging events in the time history.
  M.Z. Nuawi , M.J. M. Nor , N. Jamaludin , S. Abdullah , F. Lamin and C.K. E. Nizwan
  This study presents the development of an alternative statistical analysis method called Integrated Kurtosis-based Algorithm for Z-filter (I-kaz). The I-kaz analysis was developed in order to measure the degree of data scattering with respect to the data centroid for a dynamic signal analysis. The I-kaz parameter of a particular signal was determined by the value of I-kaz coefficient. The algorithm of I-kaz analysis provides a three dimensional graphic display of the magnitude distribution, which each axis represents the data distribution of the signal at three different frequency ranges. The I-kaz method which is a graphic-based technique is a proactive signal analysis tools because the relevant information can be extracted and the I-kaz space of scattering can be directly interpreted. The reliability of the I-kaz method has been evaluated by observing the I-kaz coefficient for a multivariate signal analysis and the trend of the coefficient values were compared to the existing statistical parameters, which are the standard deviation, variance, kurtosis and root mean square (rms). Finally, the applicability of the I-kaz method was accordingly verified.
  S. Abdullah , M. D. Ibrahim , Z. Mohd Nopiah and A. Zaharim
  This study presents the description of fatigue damage in the context of the statistical process control paradigm. The quality control approach that was used in the analysis was needed in order meet the requirements as well as improving the fatigue damage caused by variable amplitude loading. The methodology discussed in this study is enabling to reduce variability with the specification limits at three standard deviations on both side of the mean value. This concept was used to comparing three ARIMA models that have been previously found based on potential capability value (Cp) and Mean Squared Deviation (MSD). The assumption was made when the process reached the upper and the lower control limits in term of reducing the variability that was described by a variable amplitude fatigue loading. A successive three-sigma concept was then applied and developed on to this type of loading and it purpose was to detect the variation. Finally, it is suggested that the three-sigma concept provided a good platform for analyzing the fatigue damage in the aspect of the durability assessment.
  S. Abdullah , E. Adril , A. Muchtar and A.K. Ariffin
  In order to combat dry lubrication occurred in the combustion chamber of a compressed natural gas direct injection engine, the piston or piston rings have to be equipped with measures to address this boundary lubrication issue. Hence, the aim of the study is to address the issue which can minimize sliding friction in the combustion chamber between the piston ring and the cylinder liner. To solve this problem, the wear resistance level toward friction for piston ring during its interaction with the cylinder liner was enhanced using diffusion coating technique. The piston ring is made of ASSAB DF-3 steel and several substances such as 0.9% carbon (C), 0.85% chromium (Cr), 96.6% ferric (Fe), 1.2% manganese (Mn) and 0.55% titanium. The chemical substance which is used for the diffusion process are the mixture of three substances i.e., chromium, ammonium chloride (NH4Cl) and aluminum oxide (Al2O3). The piston ring together with the chromium mixtures were heated at different periods of time. In order to improve friction and wear, the piston ring which is coated with 99.5% chromium dust using a diffusion coating technique yields higher hardness compared to the original piston ring due to its resistance toward wear. The hardness depends on the time maintained during heating. Furthermore, it was also shown that the modified piston ring led to better reduction in coefficient of friction as well as less weight loss due to wear. These characteristics can result in better endurance during engine operation and prevent damage due to lubrication failure.
  Z.M. Nopiah , M.N. Baharin , S. Abdullah and M.I. Khairir
  Abrupt changes are changes that occur at a time instant at which properties suddenly change, but before and after which properties are constant in some sense. The detection of abrupt changes refers to the determination whether, such a change occurred in the characteristics of the considered subject. Running Damage Extraction (RDE) method is a new technique that was developed based on the fatigue damage calculation in detecting the abrupt changes. The objective of this study was to observe the capability of RDE method in analyzing fatigue data for detection of abrupt changes. For the purpose of this study, a collection of nonstationary data that exhibits a random behavior was used. This random data was measured in the unit of microstrain on the lower suspension arm of a car. Experimentally, the data was collected for 60 sec at a sampling rate of 500 Hz, which gave 30,000 discrete data points. By using RDE algorithm, a running damage plot was constructed in monitoring the damage changes for fatigue data. Global signal statistical value indicated that the data were non Gaussian distribution in nature. The result of the study indicates that RDE technique is applicable in detecting the abrupt changes that exist in fatigue time series data by isolating the high and low amplitude event into different segmentation.
  A. Lennie , S. Abdullah , Z.M. Nopiah and M.N. Baharin
  This study presents an analysis on variable amplitude loading strains data by using amplitude probability distribution function, power spectral density function and cross correlation function techniques. The objectives of this study are to observe the capability of these techniques in investigating the time series behaviour in terms of distribution and statistical values and also detecting the similarity of pattern signal. In this study, the data consisting of non-stationary variable amplitude loading strains data exhibiting a random behaviour was used as a set of case study. This random data was collected on the lower suspension arm of an automobile component travelling on pavé and highway route. The data was repetitively measured for 60 sec at the sampling rate of 500 Hz, which provided 30,000 discrete data points. The collected data was then calculated and analysed for the signal distribution, statistics parameter and cross correlation values. Higher calculated cross correlation values were then selected to analyse fatigue damage prediction. From amplitude probability distribution function and power spectral density function diagrams, the result can be concluded that the non-Gaussian distribution can be related to a broad band signal, while for Gaussian distribution for a narrow band signal. The findings from this study are expected to be used in determining the pattern behavior that exists in VA signals.
  F.Y. Lim , S. Abdullah and I. Ahmad
  In the present analysis, a microchannel heat sinks configuration was simulated by modelling the stacked microchannel heat sinks in a macroscopic scale as if it is a fluid saturated porous medium. The numerical solutions were obtained using the Brinkman and the general heat transfer based formulation. In order to accurately predict the permeability and heat transfer of the stacked microchannels, the simulations were compared with the simulation of a single microchannel heat sink assuming incompressible flow. The advantage of the proposed method is that no assumption on the laminar or fully develop nature of the flow is required. Therefore, this approach can also be used for developing flows in the channel. The important entrance effect which was neglected by previous researchers was also considered in the current simulation. Besides that, in the simulation of large microchannels stack, the proposed method reduce the computing time by approximately one order of magnitude when compared to the conventional approach of simulating individual microchannels. The extended works of the verified porous-media-like-microchannels were combined to be part of a computational domain of a CFD simulation. In the simulations, two cases were conducted under the same pump and the same pressure drops limitations. Good agreements were found with the simulations with discrepancy of 0.25-0.38%. The results were compared with numerical solutions and experimental results from the past reports. The fluid flow and thermal performance of microchannel heat sinks were well predicted with less than 5% discrepancy.
  S. Abdullah , S.K. Abdul Mudalip , S. Md. Shaarani and N.A. Che Pi
  Attempt was made in this research to extract the oil from Monopterus albus or commonly known as eel by using assisted ultrasonic extraction method. The effects of different ultrasonic power, solvents volume and sonication time on extraction yields were investigated. The ultrasonic power used was 100, 200, 300 and 450 Watts. The amount of ethanol or solvent used was 50, 100, 200 and 500 mL. In terms of sonication time it was varied at 20, 30, 50, and 60 min. Analysis was done using 785 DMP Titrino and Gas Chromatography Mass Spectrometer (GC-MS). Results obtained show that the maximum ultrasonic power of 200 Watts, ethanol volume of 500 mL and 60 min of sonication time produce the higher yields of oil extracts. The yields were 7.20% with FFA content of 0.22 (g/100 g). The FFA detected from chromatographic analysis using GC-MS was palmitic acid and stearic acid.
  Z. Karim , M.Z. Nuawi , A.Y. Md Said , J.A. Ghani and S. Abdullah
  The response of Integrated Kurtosis-Based Algorithm for Z-Notch Filter (I-kazTM) Multilevel coefficients toward the simultaneous changes in amplitude and frequency of signals was unknown. This study presents the coefficients responses toward the synthetic signals which vary in amplitude and frequency simultaneously. The I-kazTM Multilevel coefficients, 3rd order (3Z), 4th order (4Z), 5th order (5Z), 6th order (6Z), 7th order (7Z) and 8th order (8Z) were investigated by analyzing their response using three types of synthetic signals, FIAI, FIAD and FDAI. The responses of the I-kazTM Multilevel coefficients were analyzed by either increasing or decreasing the amplitude and frequency in the synthetic signals simultaneously. This study indicated that the response of all orders of I-kazTM Multilevel coefficients showed an increasing trend with respect to the increment in amplitude of FIAI and FDAI. All the coefficients however showed a decreasing trend in FIAD synthetic signal study regardless the increase in the frequency. The study also indicated that the change in amplitude has more influence than the change in frequency in the I-kazTM Multilevel coefficients responses. The influence ratio of the amplitude to frequency change was estimated to be 86.96-13.06%, respectively. Recognizing the behaviour of I-kazTM Multilevel coefficients toward the change in amplitude and frequency is important especially when analysing dynamic signals.
  A.A. Lashlem , D.A. Wahab , S. Abdullah and C.H. Che Haron
  In recent years, many industrial countries face the consequences of a wide flow of consumer goods and limited product life spans, resulting in a continuous increase in the quantity of used manufactured goods. This occurrence certainly increases the problem of disposal of used products. In this study, of particular interest is the disposal of solid waste from used vehicles. With the facilities of landfill sites rapidly declining due to government legislations, problems of solid waste disposal would continue persist. At present, environmental concerns and government legislations in many developed and developing countries are increasingly guided by the inventor principle, which capitalizes that inventors, designers, or whosoever inflict damage on the environment should likewise remove such damage. This, in turn, has compelled manufacturers to undertake recycling efforts at the end-of-life stage of their products. This entire exercise has resulted in huge implications on the product end-users, producers and the end-product recyclers. Designing for the environment is a necessary concern throughout the life cycle of a product. This means, that the recyclability of a product or its parts should be deliberated on from the on-set, namely from the design, manufacture, use or service, until the end-of-life stage. Management of solid wastes from vehicles considers product recycling by reuse, remanufacturing and reassembling, which is collectively known as End-of-Life-Vehicle (ELV) consequently, this study explores the efforts thus far in published literatures, to implement ELV around the world.
  M.M. Rahman , A.K. Ariffin , S. Abdullah , M.M. Noor , R.A. Bakar and M.A. Maleque
  This study describes the finite element based fatigue life prediction of cylinder head for a two-stroke free piston linear engine subjected to variable amplitude loading, applicable to electric power generation. A set of aluminum alloys, cast iron and forged steel for cylinder head are considered in this study. The finite element modeling and analysis were performed utilizing the finite element analysis codes. The fatigue life analysis was carried out using finite element based fatigue analysis commercial codes. Fatigue stress-life approach was used when the piston is subjected to variable amplitude at different loading conditions. The effects of mean stress and sensitivity analysis on fatigue life are discussed. From the results, it was shown that the Goodman mean stress correction method is predicted more conservative (minimum life) results. It was found to differ significantly the compressive and tensile mean stresses. The compressive mean stress are beneficial however tensile mean stress detrimental to the fatigue life. The effect of materials and components S-N was also investigated and not found to give any large advantages, however the effect of certainty of survival was found to give noticeable advantages and it concluded that the 99.9% are fond to be design criteria. The proposed technique is capable of determining premature products failure phenomena.
  Y.G. Seah , A.G. Mazlan , S. Abdullah , C.C. Zaidi , G. Usup and C.A.R. Mohamed
  In this study, stomach content analyses were used to determine the feeding guild of dominant trawl species comprising leiognathids and priacanthids. Specimens were collected from the southeastern coastal waters of Peninsular Malaysia using commercial trawler. Five species of leiognathids and two species of priacanthids were caught throughout the study. The results showed that the mean value of trophic level for leiognathid species, Photopectoralis bindus was 3.22±0.49, Gazza minuta was 2.75±0.29, Secutor indicius was 2.87±0.30, Eubleekeria jonesi was 2.49±0.27, Equulites stercorarius was 2.63±0.30 and for priacanthid species, Priacanthus macracanthus was 3.51±0.47 and Priacanthus tayenus was 3.61±0.45. The results indicated that the feeding regime of P. bindus, G. minuta and S. indicius can be categorized as bentho-pelagic feeders that have forwardly or upwardly protractible mouth types and feed mainly on zooplankton and zoobenthos. E. stercorarius and E. jonesi with a downwardly protractible mouth type feed mainly on zoobenthos and can be classified as benthivorous. The results suggested that the forwardly or upwardly protractible mouth types leiognathids occupy a higher trophic level compared to the downwardly protractible mouth type leiognathids. Both priacanthids with upturned mouth type have similar diet composition consisting of crustaceans, polychaetes, ostracods, fish and cephalopods. They are thus mid-level carnivores since the species are able to consume organisms at trophic level 3.5. The results revealed that the value of trophic level for priacanthid species were higher than leiognathid species.
  W.A. Wan Noorina , Loh Wayen , Teh Lay Ann , S. Kanagasingam , S. Abdullah and M.M. Rahman
  The aim of this study was to evaluate the irrigant flow pattern of a hypodermic needle; in Micro-Computed Tomography (MCT) scanned root canals prepared using Reciproc® files at two different levels using a Computational Fluid Dynamics (CFD) model. Two lower incisors prepared with Reciproc® rotary files sized R 25 and 50, underwent MCT scanning to create 3-dimensional root canal models. A computational model of a 30 G hypodermic needle was then positioned at 3 and 5 mm from the apex in each root canal model. Irrigant flow pattern, velocity and mean apical pressure at 1 mm from the apices were evaluated using commercial CFD software, Star CCM+. The irrigant produced a high velocity jet, reaching 5.8 m sec–1, at the needle outlet and created multiple vortices near the canal wall before exiting at the canal orifice. Mean apical pressure and velocity recorded for R 25/3 mm (7.77 kPa/0.235 m sec–1), for R 25/5 mm (4.34 kPa/0.001 m sec–1), for R 50/3 mm (7.89 kPa/0.005 m sec–1) and R 50/5 mm (4.49 kPa/0.0001 m sec–1). Close proximity of the needle to the apex produced higher mean apical pressure; meanwhile, larger apical preparation sizes produced lower velocity of irrigant. It was observed that within the same canal, irrigant flow patterns were similar for both needle levels. Needle positions and apical preparation sizes were found affecting the apical pressure and velocity. The CFD simulations in MCT scanned root canals were clinically significant.
  R. Kittaneh , S. Abdullah and A. Abuhamdah
  Clustering problem is a type of classification under optimisation problems, which is considered as a critical area of Data Mining. Medical clustering problem is a type of unsupervised learning in data mining. This study has presented an enhancement of K-Means (i.e., Multi K-Means) and iterative simulated annealing algorithm for solving medical clustering problems. The aim of this study was to improve the K-Means algorithm for a better performance and produce an effective algorithm for partitioning N objects into K clusters. The structure of the Iterative Simulated Annealing (ISA) algorithm resembles a Simulated Annealing (SA) algorithm structure. The basic difference is that, in ISA the temperature is reinitialized for further improvement, whilst, in SA the temperature is initialized only once at the beginning of the search. Therefore, ISA has a better capability of escaping from a local optima compared to SA and attempts to enhance the trial solution by exploring different neighborhood structures to overcome the limitation of the SA and by the swap mechanism ISA is able to get further improve. Experimental results obtained by three way of calculating the minimal distance that have been tested on six benchmark medical datasets that are available in UCI Machine Learning Repository show that, ISA algorithm with more computational time (coded as IISA) is able to produce significantly good quality solutions and outperformed SA and ISA algorithms on all datasets.
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