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Ali M.S.M.,Malaysia Japan International Institute of Technology | Doolan C.J.,University of Adelaide | Wheatley V.,University of Queensland
International Journal of Heat and Fluid Flow | Year: 2012

A numerical study of the alteration of a square cylinder wake using a detached downstream thin flat plate is presented. The wake is generated by a uniform flow of Reynolds number 150 based on the side length of the cylinder, D. The sensitivity of the near wake structure to the downstream position of the plate is investigated by varying the gap distance (G) along the wake centerline in the range 0≤G≤7D for a constant plate length of L=D. A critical gap distance is observed to occur at G c≈2.3D that indicates the existence of two flow regimes. Regime I is characterised by vortex formation occurring downstream of the gap while for regime II, formation occurs within the gap. By varying the plate length and gap distance, a condition is found where significant unsteady total lift reduction can occur. The root mean square lift reduction is limited by an unsteady stall process on the plate. © 2012 Elsevier Inc.

Ali M.S.M.,Malaysia Japan International Institute of Technology | Doolan C.J.,University of Adelaide | Wheatley V.,University of Queensland
AIAA Journal | Year: 2013

The case of a rigid flat plate placed in the wake of a square cylinder for passive sound control is investigated numerically at a Reynolds number of 150 and a Mach number of 0.2. Two flow regimes are observed, and these are shown to affect the radiated sound. An overall sound reduction at an observer directly above the cylinder is observed for a small gap distance G between the cylinder and the plate (0 ≤ G ≤ 2.3D, in which D is the cylinder height), where a 2.9 dB reduction in the sound-pressure level is obtained when there is no gap between the two bodies. In contrast, the emitted sound-pressure level increases by at least 8.0 dB for large gap distances (2.4D ≤ G ≤ 7D). Despite this, a 6.3 dB reduction in the sound-pressure level is obtained due to a sound-cancellation mechanism when the plate length is reduced to 0.26D and placed 5.6D downstream of the cylinder. The maximum sound reduction attainable is shown to be limited by the nonlinear unsteady stall process on the plate. Copyright © 2012 by the American Institute of Aeronautics and Astronautics, Inc. All rights reserved.

Yazid I.I.M.,Malaysia Japan International Institute of Technology | Mazlan S.A.,Malaysia Japan International Institute of Technology | Kikuchi T.,Yamagata University | Zamzuri H.,University of Technology Malaysia | Imaduddin F.,University of Technology Malaysia
Materials and Design | Year: 2014

Magnetorheological (MR) damper is a semi-active suspension device that uses MR fluid to produce controllable damper. The mechanical properties of the suspension can be controlled by adjusting the yield stress of MR fluid. This paper presents the design of a new concept for MR damper with a combination of shear and squeeze working modes. Finite Element Method Magnetics (FEMM) was utilized to simulate the magnetic field generated by electromagnetic coils in MR damper. The MR damper was designed and fabricated according to the simulation results. The experimental tests were performed under quasi-static loading in three different conditions; shear mode, squeeze mode and combination of both modes. The results showed that the mixed mode MR damper has produced a unique damping characteristic where in general, a higher damping force has obtained in mixed mode than single mode. © 2013 Elsevier Ltd.

Manzo K.,Northumbria University | Padfield R.,Malaysia Japan International Institute of Technology
Transactions of the Institute of British Geographers | Year: 2016

To date, debates about climate change reporting in national media focus largely on Western democracies. We aim to broaden the scope for cross-national comparison by looking at climate change reporting in Malaysia - an emerging economy in the global South facing developmental tensions common to many, specifically an ambitious national climate change agenda in the face of an economy largely reliant on the extraction and export of primary commodities. Our questions are: How is climate change framed in Malaysian media? How do Malaysian narratives compare with those found elsewhere? How do climate change and development narratives interact in a 'second tier' emerging economy? And lastly, what do these interacting narratives say about the salience of neoliberal and North-South perspectives on climate change and development? To answer these questions, we undertook a content analysis of climate action stories published over a three-year period (2009-2011) in five English-language news sources. In addition to a high proportion of environmental-framed articles across all the news sources, our findings show that climate change has been framed as both a multi-scalar responsibility and a positive opportunity for two key stakeholders in development, i.e. neoliberal market forces and geopolitical actors keenly interested in restructuring the international political economy along lines reminiscent of the new international economic order (NIEO) demands of the 1970s. We label the key themes emergent from our analysis as climate capitalism and green nationalism (neither of which are unique to Malaysia), while demonstrating that debates about palm oil are particularly illustrative of the interaction of these themes in the Malaysian context. In the final section we suggest thinking of the interacting elements as a singular, structuralist model of green development - one reminiscent of discourses at work in other emerging economies. Copyright © 2016 Royal Geographical Society (with the Institute of British Geographers).

Nasef M.M.,University of Technology Malaysia | Nasef M.M.,Malaysia Japan International Institute of Technology
Chemical Reviews | Year: 2014

Fuel cell technology is one of the key emerging technologies that is currently attracting tremendous effort with the aim to provide alternative environmentally friendly and efficient power sources. The worldwide move away from conventional fossil fuel combustion power generation technologies is driving much of this important research. The replacement of a liquid electrolyte by PEM in such systems has eliminated the corrosion problems and conferred on the system additional advantages such as simplicity of construction, compactness, and quick self-starting at ambient temperatures. The successful performance of these kinds of fuel cell systems depends critically on the role played by the PEM. The second category involves the formation of acid-base complexes that provide a viable alternative for membranes that can maintain high conductivity at elevated temperatures without suffering from dehydration effects.

Imaduddin F.,University of Technology Malaysia | Mazlan S.A.,Malaysia Japan International Institute of Technology | Zamzuri H.,University of Technology Malaysia
Materials and Design | Year: 2013

The trend and progress in rotary magnetorheological (MR) damper development is currently not as extensive as the advancement of linear MR damper, despite the fact that it has several comparative advantages. A rotary MR damper offers substantial weight reduction and design compactness thus requiring smaller space than a linear MR damper for device installation. In addition, a rotary damper also utilizes a smaller quantity of MR fluid, which is a significant contribution for cost reduction. In this paper, an overview of recent advances in rotary MR damper are presented, in terms of different proposed concepts of structural design, magnetic circuit configuration, and modelling techniques. The review separates rotary MR damper design into two categories, namely continuous angle and limited angle dampers. Issues regarding device endurance, ease of manufacturing and maintenance and controllability are particularly highlighted. © 2013 Elsevier Ltd.

Asako Y.,Malaysia Japan International Institute of Technology
Journal of Heat Transfer | Year: 2016

The energy equation for constant density fluid flow with the viscous dissipation term is often used for the governing equations of gas flow with low velocity in microchannels. If the gas is an ideal gas with low velocity, the average temperatures at the inlet and the outlet of an adiabatic channel are the same based on the first law of the thermodynamics. If the gas is a real gas with low velocity, the average temperature at the outlet is higher or lower than the average temperature at the inlet. However, the outlet temperature which is obtained by solving the energy equation for constant density fluid flow with the viscous dissipation term is higher than the inlet gas temperature, since the viscous dissipation term is always positive. This inconsistency arose from choice of the relationship between the enthalpy and temperature that resulted in neglecting the substantial derivative of pressure term in the energy equation. In this paper, the energy equation which includes the substantial derivative of pressure term is proposed to be used for the governing equation of gas flow with low velocity in microchannels. The proposed energy equation is verified by solving it numerically for flow in a circular microtube. Some physically consistent results are demonstrated. © Copyright 2016 by ASME.

Yamada M.,Malaysia Japan International Institute of Technology
2016 IEEE 6th International Conference on Photonics, ICP 2016 | Year: 2016

Analytical method of noise in the semiconductor optical amplifier (SOA) has not been established yet. The basic problem is how introduce quantized optical field with the Langevin noise sources in the open wave guide, because the SOA has not have facets mirrors to confine the optical field in the device. The author's group introduced an idea to define finite size of photons based on the quantum mechanical property of the spontaneous emission. The longitudinal mode for the traveling optical field is defined for optical signal and the generated spontaneous emission. Then, the intensity (IM) noise, the frequency (FM) noise and the spectral linewidth were theoretically calculated. Characteristics of these noise were also experimentally confirmed. © 2016 IEEE.

Othman M.F.,University of Technology Malaysia | Shazali K.,Malaysia Japan International Institute of Technology
Procedia Engineering | Year: 2012

Development in the technology of sensor such as Micro Electro Mechanical Systems (MEMS), wireless communications, embedded systems, distributed processing and wireless sensor applications have contributed a large transformation in Wireless Sensor Network (WSN) recently. It assists and improves work performance both in the field of industry and our daily life. Wireless Sensor Network has been widely used in many areas especially for surveillance and monitoring in agriculture and habitat monitoring. Environment monitoring has become an important field of control and protection, providing real-time system and control communication with the physical world. An intelligent and smart Wireless Sensor Network system can gather and process a large amount of data from the beginning of the monitoring and manage air quality, the conditions of traffic, to weather situations. In this paper, we discuss and review wireless sensor network applications for environmental monitoring. In order to implement a good monitoring system, there are several requirements to be followed. From the studies, it has been proved to be an alternative way to replace the conventional method that uses men force to monitor the environment. It is also proven that these approaches can improve the system performance, provide a convenient and efficient method and can also fulfill functional requirements. © 2012 Mohd Fauzi Othman and Khairunnisa Shazali.

Darvill D.,Imperial College London | Centeno A.,Imperial College London | Centeno A.,Malaysia Japan International Institute of Technology | Xie F.,Imperial College London
Physical Chemistry Chemical Physics | Year: 2013

This review focuses on metal enhanced fluorescence (MEF) and its current and future applications in biotechnology. The mechanisms of MEF are discussed in terms of the additional radiative and nonradiative decay rates caused by the close proximity of the metal. We then review the current MEF materials and structures that show promise in bioapplications. The use of electromagnetic modelling to predict fluorescent rate enhancement is then considered. We then give particular focus to the recent work carried out in the homogeneous fabrication of metal nanoparticles using colloidal lithography. It is concluded that the use of computational electromagnetic modelling alongside homogeneous fabrication techniques will lead to predictable and controllable MEF, paving the way for increased applications in biotechnology. © 2013 The Owner Societies.

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