Published by
Penerbit Universiti Sains Malaysia



Print ISSN: 1823-3430
Online ISSN: 2180-4214
Frequency: Annually
Current Issue: Volume 14, 2018
Abstracting/Indexing: MyJurnal, ProQuest, Google Scholar, Genamics JournalSeek, WorldCat


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Aims and Scope

The Journal of Engineering Science presents a broad interdisciplinary knowledge hub on novel international practices and the most recent research findings of practical importance in all aspects of engineering science that could be of benefit to any community worldwide. This international journal aims to be a catalyst towards the eventual success of the United Nations Decade of Education for Sustainable Development (UNDESD) programme. A hallmark of this journal papers is that they are interdisciplinary in nature, a distinction of findings involving collaboration between traditional engineering disciplines and other scientific fields of specialization. Transdiscipline scope of the Journal will focus on all aspects of engineering disciplines; which could include design, development of engineering techniques, engineering technology, government and legislative policies, engineering management, mathematical modelling of engineering processes, cost optimization, economic aspects of industry, impact of engineering practices on society, biotechnology, nanotechnology, medical image analysis, fuel cells, fibre optics, robotics, offshore foundations, optoelectronics, superconductivity, hypersonics, turbomachinery, coastal management, structural integrity, physiological modelling, ophthalmic technology, geophysics and environmental management via treatment and control of hazardous wastes among others. The objective of this Journal is to enhance communication and understanding across all aspects of global engineering science fraternity via the publications of peer-reviewed and original papers on engineering advancement and solutions to problems worldwide.


The Journal of Engineering Science herewith announces its decision to retract article Controllability of Hybrid Model Reference Fuzzy Logic Controller for Load Disturbances in Shell-and-Tube Heat Exchanger Temperature System which was scheduled for publication in Volume 10 (2014). The decision is made upon discovery that an article of similar contents have been published in another journal.

All manuscripts submitted for publication must be original, previously unpublished, and not under consideration for publication elsewhere. Its publication must be approved by all Authors and tacitly or explicitly by the responsible authorities where the work was carried out, and that, if accepted, it will not be published elsewhere in the same form, in English or in any other language, without the written consent of the publisher, Penerbit Universiti Sains Malaysia.


Publication Ethics

Journal of Engineering Science adheres to the Committee on Publication Ethics (COPE) standards on publications ethics. For further details please visit:


Current Issue


Volume 14, 2018
 

Title: Investigation of Human Kinetic Energy Harvesting from Human Foot Strike
Author: Joo Ann Teh and Zuraini Dahari
Source: Journal of Engineering Science 14: 1–14, 2018
 
- Abstract  

Due to the increasing demand of wireless sensor and low power consumer electronic device demand, energy harvesting from human motion become more favoured in recent years. In this study, an energy harvester based on human foot strike is proposed. The kinetic energy is harvested by using the piezoelectric materials and converted into an electrical energy. The effect of different types and different circuit configurations of piezoelectric materials are investigated in this study. Besides, the effect of several factors such as human body weight, gender and walking speed are also investigated. It is found that the MCFT–41T–1.0A1–141 piezoelectric ceramic which is thinner and greater in diameter can generate the greatest amount of electrical energy, which is 30.97 μW, whereas the best configuration is series connection. Besides, the electrical energy generated by people with greater body weight and faster walking speed are also higher. Finally, results also showed that a male can generate greater amount of electrical energy when compared to female.

Keywords: Energy harvesting, piezoelectric, human foot strike, electrical energy production

Title: Development of Heartbeat Based Biometric System Using Wavelet Transform
Author: Chin Chee Yeen and Dzati Athiar Ramli
Source: Journal of Engineering Science 14: 15–33, 2018
 
- Abstract  

Electrocardiogram (ECG) is a new biometric trait that has an advantage as it is an internal modality which indicates to be difficult of counterfeiting. The ECG records the heart activity and it is unique as different individuals have distinct heart structure. Hence, it provides vital information for differentiating one individual from another. One of the techniques to extract the salient information from the ECG signal is by using discrete wavelet transform (DWT). However, in order to develop a reliable ECG based biometric system using DWT, there are many parameters that need to be determined. In this study, we study the effect of different parameters used for de-noising orders, threshold levels and type of mother wavelets to the final authentication performance of our developed system. For the authentication stage, Support Vector Machine (SVM) is used as classifier. The system performance is evaluated based on Genuine Acceptance Rate (GAR), False Acceptance Rate (FAR) and Equal Error Rate (EER) by using the scores given by the SVM. The combination of de-noising order 3, heursure threshold method and db6 mother wavelet yields the top performance with GAR of 92.5% at FAR of 5% and EER of 6.9499% have been achieved. At the end of this paper, a simple ECG based security system is then constructed so as to show the feasibility of this study to be implemented in real-time situation.

Keywords: Biometrics, electrocardiogram, wavelet transform, authentication, support vector machine

Title: In Vitro Biocompatibility of SiCHA Nanopowders on Human Mesenchymal Stem Cells
Author: Yanny M. Baba Ismail, Ian Wimpenny, Oana Bretcanu, Kenneth W. Dalgarno and Alicia J. El Haj
Source: Journal of Engineering Science 14: 35–46, 2018
 
- Abstract  

Synthetic hydroxyapatite (HA) possesses good biocompatibility, bioactivity and osteoconductivity and closely mimics the mineralised phase of human bone and teeth. However, for many years the clinical researchers worldwide have been aware that the mineral phase of bone is not solely HA but contains a number of substituents (e.g. CO3, Si, Zn, Sr, Na and Mg). Among the substituents, carbonate is the major substitute ions which are present about 2–8 wt. % depending mainly on the individual age. The presence of approximately 1 wt. % Si is known to be essential in bone formation and calcification. Thus, the present study is aimed at developing a new biomaterial consisting both of these two biologically important cations into the HA structure by synthesising silicon carbonated HA (SiCHA) powders via nanoemulsion method, and to assess the in vitro biocompatibility of the as-synthesised powders in response to human Bone Marrow derived Mesenchymal Stem Cells (hMSCs). Both the carbonate and silicon ions were successfully substituted into the HA lattice. Powders with carbonate encouraged better cell activity in comparison to the carbonate-free powders. While, SiHA and SiCHA–1 as-synthesised powders with high amount of Si (> 1 wt. %) tend to kill some cells at the early stage of seeding and hinder cells activity afterwards. Among the tested powders, SiCHA–2 as-synthesised powders is chosen as the optimum composition as it exhibited the highest cell viability and proliferation besides having the closest amount of carbonate and Si ions to the bone mineral.

Keywords: Silicon carbonated hydroxyapatite, nanopowders, human mesenchymal stem cells, in vitro biocompatibility test, bone tissue engineering

Title: Effect of Carbon in Brake Friction Materials on Friction Characteristics
Author: Talib Ria Jaafar, Aznifa Mahyam Zaharudin, Arif Pahmi, Ramlan Kasiran and Eliasidi Abu Othman
Source: Journal of Engineering Science 14: 47–59, 2018
 
- Abstract  

Brake friction materials composed of eight to 20 ingredients in the formulation. Each ingredient has its own function in producing the stable coefficient of friction (COF) and acceptable wear rate. The goal of this work is to study the effect of different carbon volume percentage (vol. %) on the friction characteristics. Three samples were prepared through powder metalurgy process by varying the carbon vol. %. Each sample was subjected to specific gravity, porosity, hardness, chase friction and brake inertia dynamometer tests in accordance with international test procedures. All the entire three samples are sensitive to speed and temperature. COF increased in the early stage of braking. Upon reaching the degradation temperature of polymeric materials, the COF decreased gradually with increasing speed and temperature. The pad thickness loss and rotor roughness decreased with increasing vol. % of carbon in the formulation. Sample B is the best formulation based on the friction characteristics and pad thickness loss. Formulation of sample C is rejected due to lower COF even though has the lowest pad thickness loss. Sample A and sample B will be further analysed and evaluated on-road and reliability performance before can be commercialised and used on the road.

Keywords: Brake friction materials, carbon, COF, speed, temperature sensitivity

Title: Roles of Slip Agent in Blown Film Extrusion of Linear Low Density Polyethylene
Author: Nur Haslina Nasirah Abdul Hadi, Mohd Fairuz Zainal Abidin and Raa Khimi Shuib
Source: Journal of Engineering Science 14: 61–70, 2018
 
- Abstract  

In this work, the effects of different contents of slip agent (0, 800, 1,000, 1,200 and 1,500 ppm) on the surface friction and tensile properties of Linear Low Density Polyethylene (LLDPE) films were investigated. The mixture of LLDPE and slip agent was first compounded and palletised using twin screw extruder and subsequently processed into film using extrude blow film machine. Coefficient of friction (COF), tensile strength, elongation at break, Young's modulus and gel count of the produced film were investigated. It was found that COF, tensile strength and Young's modulus decreased with increase in contents of slip agent but the elongation at break was found to slightly increase. It was also found that the gel count increased as the contents of slip agent increased which might be due to remaining slip agent or contamination in the materials.

Keywords: Slip agent, LLDPE, films, COF, tensile properties

Title: Mathematical Implications of Hydrogeological Conditions: Modelling for Aquifer Parameters Determination
Author: Sheriffat Taiwo Okusaga, Mustapha Adewale Usman and Niyi Olaonipekun Adebisi
Source: Journal of Engineering Science 14: 71–99, 2018
 
- Abstract  

Formulations of natural hydrogeological phenomena have been derived, from experimentation and observation of Darcy fundamental law. Mathematical methods are also been applied to expand on these formulations, but the management of complexities which relate to subsurface heterogeneity is yet to be developed into better models. This study employs a thorough approach to modelling flow in an aquifer (a porous medium) with phenomenological parameters such as Transmissibility and Storage Coefficient on the basis of mathematical arguments. An overview of the essential components of mathematical background and a basic working knowledge of groundwater flow is presented. Equations obtained through the modelling process were used to separate variables and solve hypothetical problems. Based on finite-difference conservative scheme the essential components of aquifer were determined by solving problem of groundwater flow in a porous medium.

Keywords: Hydrogeological, mathematical, Darcy, aquifer, storage and transmissibility



 


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