Engineering Commons^™

Modelling Of Polyaniline For Wi-Fi Electromagnetic Interference Shielding, Whamid Al-Shabib, Stefan W. Lachowicz

Research outputs 2013

In this paper COMSOL model is used to model the s-parameters of the electromagnetic shielding of layer/layers of Polyaniline (PAni) for Wi-Fi Electromagnetic Interference (EMI) shielding. PAni has a good future for minimizing the problems with Electromagnetic Shielding (EMS), and will be increasingly be used to provide protection from Electromagnetic Radiation (EMR) and Electromagnetic Interference (EMI). With the increased development in Wi-Fi and telecommunications equipment, a simple model is required to test for transmission losses. In this paper the electromagnetic radiation from antenna, positioned 30cm from PAni shielding device is modelled using COMSOL 4.2. The paper predicts the radiation reduction …

Multi-Component Adsorption Of Benzene, Toluene, Ethylbenzene, And Xylene From Aqueous Solutions By Montmorillonite Modified With Tetradecyl Trimethyl Ammonium Bromide, Heshmatola Nourmoradi, Mehdi Khiadani, Mahnaz Nikaeen

Research outputs 2013

Multicomponent adsorption of benzene, toluene, ethylbenzene, and xylene (BTEX) was assessed in aqueous solutions by montmorillonite modified with tetradecyl trimethyl ammonium bromide (TTAB-Mt). Batch experiments were conducted to determine the influences of parameters including loading rates of surfactant, contact time, pH, adsorbate concentration, and temperature on the adsorption efficiency. Scanning electron microscope (SEM) and X-ray diffractometer (XRD) were used to determine the adsorbent properties. Results showed that the modification of the adsorbent via the surfactant causes structural changes of the adsorbent. It was found that the optimum adsorption condition achieves with the surfactant loading rate of 200 of the cation …

Earthquake Load Attenuation Using Eps Geofoam Buffers In Rigid Wall Applications, Richard J. Bathurst, S Zarnani

Research outputs 2013

The paper is a synthesis of previously published work by the authors that is focused on the use of expanded polystyrene (EPS) geofoam buffers for seismic load attenuation against rigid basement and soil retaining walls. The paper begins with a brief description of the first documented field application followed by a description of physical 1 m-high reduced-scale shaking table tests that provided the first "proof of concept". Next, details of the development and verification of a displacement-based model and a FLAC numerical model are described and simulation results that were verified against the physical shaking table tests presented. The numerical …

Roles Of Compressive Residual Stress In Enhancing The Corrosion Resistance Of Nano Nitride Composite Coatings On Steel, Xiaoli Zhao, Paul Munroe, Daryoush Habibi, Zonghan Xie

Research outputs 2013

Nanocomposite coatings were synthesized, and subsequently annealed, in an attempt to understand the influence of residual stress upon their resistance to corrosion under acidic attack. Pitting corrosion, originating from microscopic coating defects, was commonly identified in the coatings subject to annealing. Finite element analysis was used to map the residual stress distribution adjacent to these defects and quantify resulting geometrical changes. The results show that with the presence of compressive residual stress in the coatings, corrosion-initiated cracking along weak interfaces was suppressed, and structural integrity maintained. Moreover, compressive residual stress helped constrict pre-existing structural defects in columnar-structured coatings and, in …

Tuning Of The Transverse Magneto-Optical Kerr Effect In Magneto-Plasmonic Crystals, Martin Pohl, L. E. Kreilkamp, Vladimir I. Belotelov, Ilya A. Akimov, A N. Kalish, N E. Khokhlov, V J. Yallapragada, A V. Gopal, Mohammad Nur-E-Alam, Mikhail Vasiliev, D R. Yakovlev, Kamal Alameh, A K. Zvezdin, M Bayer

Research outputs 2013

The spectral properties of the transverse magneto-optical Kerr effect (TMOKE) in periodic metal–dielectric hybrid structures are studied, in particular with respect to the achievable magnitude. It is shown that the TMOKE is sensitive to the magneto-optical activity of the bismuth-substituted rare-earth iron garnet, which is used as a dielectric material in the investigated structures. For samples with larger Bi substitution level and, consequently, larger gyration constant, the magnitude of the TMOKE increases and reaches 13% in the case of a Bi1.8Lu1.2Fe3.6Al1.4O12 magnetic film. Further, it is demonstrated that the TMOKE vanishes at the high-symmetry points of the Brillouin zone (at …

Optimal Control Of Power Quality In Microgrids Using Particle Swarm Optimisation, Waleed Abood Baddai Al-Saedi

Theses: Doctorates and Masters

Driven by environmental protection, economic factors, conservation of energy resources, and technical challenges, the microgrid has emerged as an innovative small-scale power generation network. Microgrids consist of a cluster of Distributed Generation units that encompass a portion of an electric power distribution system and may rely on different energy sources. Functionally, the microgrid is required to provide adequate levels and quality of power to meet load demands. The issue of power quality is significant as it directly affects the characteristics of the microgrid’s operation. This problem can be defined as an occurrence of short to long periods of inadequate or …

Indirect Measures Of Learning Transfer Between Real And Virtual Environments, Michael J. Garrett, Mark T. Mcmahon

Research outputs 2013

This paper reports on research undertaken to determine the effectiveness of a 3D simulation environment used to train mining personnel in emergency evacuation procedures, designated the Fires in Underground Mines Evacuation Simulator (FUMES). Owing to the operational constraints of the mining facility, methods for measuring learning transfer were employed which did not require real world performance evaluation. Transfer measures that examined simulator performance relative to real world experience, fidelity assessment, and appraisal of the training value of the platform were utilised. Triangulation of results across all three measures indicated the presence of learning transfer, suggesting the viability of indirect measures …

Recent Developments In Magneto-Optic Garnet-Type Thin-Film Materials Synthesis, Mohammad Nur E Alam, Mikhail Vasiliev, Viacheslav Kotov, Kamal Alameh

Research outputs 2013

Magneto-optic (MO) garnets are used in a range of applications in nanophotonics, integrated optics, communications and imaging. Bi-substituted iron garnets of different compositions are the most useful class of materials in applied magneto- optics due to their excellent MO properties (large Faraday effect) and record-high MO figure of merit among all semi- transparent dielectrics. It is highly desirable to synthesise garnets which possess simultaneously a high MO figure of merit and large uniaxial magnetic anisotropy. However, the simultaneous optimization of several material properties and parameters can be difficult in single-layer garnet thin films, and it is also challenging to prepare …

Episodic Adaptations And Trade-Offs: Examples From The Victorian Construction Industry, Manikam Pillay, David Borys

Research outputs 2013

A central facet of resilience engineering involves adaptation which involves making temporal adjustments by responding, monitoring, anticipation and learning from disturbances continuous stressors. This ability to adapt is inherent in the actions which manifest as behaviors in individuals and teams. In the main, the response is generally in response is to regular and irregular threats such that work continues to operate as normal. Invariably, these adaptations also require trade-offs and sacrifices being made at a number of levels. However, there is little published research that seeks to explain how such adaptations actually occur in construction works. It has been suggested …

Plasmon-Mediated Magneto-Optical Transparency, Vladimir Belotelov, L. E. Kreilkamp, Ilya Akimov, A Kalish, D Bykov, S Kasture, V Yallapragada, A Gopal, A M Grishin, S I Khartsev, Mohammad Nur E Alam, Mikhail Vasiliev, L Doskolovich, D Yakovlev, Kamal Alameh, A K Zvezdin, M Bayer

Research outputs 2013

Magnetic field control of light is among the most intriguing methods for modulation of light intensity and polarization on sub-nanosecond timescales. The implementation in nanostructured hybrid materials provides a remarkable increase of magneto-optical effects. However, so far only the enhancement of already known effects has been demonstrated in such materials. Here we postulate a novel magneto-optical phenomenon that originates solely from suitably designed nanostructured metal-dielectric material, the so-called magneto-plasmonic crystal. In this material, an incident light excites coupled plasmonic oscillations and a waveguide mode. An in-plane magnetic field allows excitation of an orthogonally polarized waveguide mode that modifies optical spectrum …

Energy Efficiency Performance Improvements For Ant-Based Routing Algorithm In Wireless Sensor Networks, A. M. Zungeru, Kah Phooi Seng, Li-Minn Ang, W.C. Chia

Research outputs 2013

The main problem for event gathering in wireless sensor networks (WSNs) is the restricted communication range for each node. Due to the restricted communication range and high network density, event forwarding in WSNs is very challenging and requires multihop data forwarding. Currently, the energy-efficient ant based routing (EEABR) algorithm, based on the ant colony optimization (ACO) metaheuristic, is one of the state-of-the-art energy-aware routing protocols. In this paper, we propose three improvements to the EEABR algorithm to further improve its energy efficiency. The improvements to the original EEABR are based on the following: (1) a new scheme to intelligently initialize …

Oscillation Built-In-Self-Test For Adc Linearity Testing In Deep Submicron Cmos Technology, Koay Soon Chan, Nuzrul Fahmi Nordin, Kim Chon Chan, Terk Zyou Lok, Chee Wai Yong, Adam Osseiran

Research outputs 2013

This paper proposes an Oscillation BIST (OBIST) that is meant to test ADCs fabricated in sub 100nm processes. The design is intended to be capable of testing a 10-bit ADC that was designed in 40nm CMOS. The design scheme presents a simple analog stimulus generator that was designed in 40nm CMOS together with schematic based simulation results. There is also a description of a calibration circuit and a highlevel implementation of a BIST control system to run the BIST and to calculate static parameters such as Differential Non-linearity (DNL) and Integral Non-linearity (INL). Simulation results for the analog stimulus generator …

Free-Space Optics For High Speed Reconfigurable Card-To-Card Optical Interconnects, Ke Wang, Ampalavanpillai Nirmalathas, Christina Lim, Efstratios Skafidas, Kamal Alameh

Research outputs 2013

High-speed card-to-card optical interconnects are highly demanded in high-performance computing and data centers. Compared with other solutions, free-space optical interconnects have the capability of providing both reconfigurability and flexibility. In this paper we propose and experimentally demonstrate a free-space based reconfigurable optical interconnect architecture and it is capable of connecting cards located both inside the same rack as well as in different racks. Results show that 3xiO Gb/s data transmission is achieved with a worst-case receiver sensitivity better than -9.38 dBm.

Unidirectional Coupling Of Surface Plasmons With Ultra-Broadband And Wide-Angle Efficiency: Potential Applications In Sensing, Kun Li, Feng Xiao, Fan Lu, Kamal Alameh, Anshi Xu

Research outputs 2013

A cascaded-grating coupling scheme for unidirectionally coupling and launching surface plasmons from free-space light with ultra-broadband and wide-angle efficiency is proposed and theoretically investigated, and the potential applications in sensing are discussed. The cascaded sub-gratings of different periods couple the incident light over a relatively wide wavelength and angular range into surface plasmon polaritons (SPPs). After traveling a short distance, the SPPs interact with the sensed medium, and then are coupled back into freely propagating light through the nanoslit in the metal film. By observing the changes of SPP-mediated light coupled out through the slit, broadband sensing is achieved. A …

Optical Magnetometer Employing Adaptive Noise Cancellation For Unshielded Magnetocardiography, Valentina Tiporlini, Kamal Alameh

Research outputs 2013

This paper demonstrates the concept of an optical magnetometer for magnetocardiography. The magnetometer employs a standard Least-Mean-Squares (LMS) algorithm for heart magnetic field measurement within unshielded environment. Experimental results show that the algorithm can extract a weak heart signal from a much-stronger magnetic noise and detect the P, QRS, and T heart features and completely suppress the common power line noise component at 50 Hz.

Optical Fiber Bragg Grating Based Intrusion Detection Systems For Homeland Security, Gary Allwood, Steven Hinckley, Graham Wild

Research outputs 2013

This paper describes the use of optical Fiber Bragg grating (FBG) sensors for use in various intrusion detection systems for homeland security. We show that a FBG sensor can be used effectively as an embedded in-ground acoustic sensor, sensitive enough to detect the acoustic emissions associated with walking on a concrete surface. Also, the FBG can be used as an in-ground pressure switch for intrusion detection through temporary flooring materials, such as tiles and wooden laminate. In addition, we verify the use of FBGs as in-fence perimeter breach detectors. Finally, we show how an FBG can be used as a …

High Sensitivity Optically Pumped Quantum Magnetometer, Valentina Tiporlini, Kamal Alameh

Research outputs 2013

Quantum magnetometers based on optical pumping can achieve sensitivity as high as what SQUID-based devices can attain. In this paper, we discuss the principle of operation and the optimal design of an optically pumped quantum magnetometer. The ultimate intrinsic sensitivity is calculated showing that optimal performance of the magnetometer is attained with an optical pump power of 20 W and an operation temperature of 48°C. Results show that the ultimate intrinsic sensitivity of the quantum magnetometer that can be achieved is 327 fT/Hz1/2 over a bandwidth of 26 Hz and that this sensitivity drops to 130 pT/Hz1/2 in the presence …

The Optimisation Of A Turbulent Swirl Nozzle Using Cfd, Brett K. Thomas, Zahir U. Ahmed, Yasir M. Al-Abdeli, Miccal T. Matthews

Research outputs 2013

Swirl is imparted into free and impinging nozzle flows as well as jet flames to affect convective heat transfer, fluid mixing or flame stability. At the nozzle exit plane, the emerging flow strongly influences downstream flow development and so factors which impact upon the emitted flow are worthy of study. This paper presents preliminary CFD analyses into the effect of design parameters and operational settings on the emerging flow at the exit plane for a swirl nozzle (Remax~30,500). The research was conducted in the premanufacture stage to optimise the nozzle. Swirl is aerodynamically generated using multiple tangential ports located upstream …

Position Control Of Electro-Hydraulic Actuator System Using Fuzzy Logic Controller Optimized By Particle Swarm Optimization, Daniel M. Wonohadidjojo, Ganesh Kothapalli, Mohammed Hassan

Research outputs 2014 to 2021

The position control system of an electro-hydraulic actuator system (EHAS) is investigated in this paper. The EHAS is developed by taking into consideration the nonlinearities of the system: the friction and the internal leakage. A variable load that simulates a realistic load in robotic excavator is taken as the trajectory reference. A method of control strategy that is implemented by employing a fuzzy logic controller (FLC) whose parameters are optimized using particle swarm optimization (PSO) is proposed. The scaling factors of the fuzzy inference system are tuned to obtain the optimal values which yield the best system performance. The simulation …

The Effect Of Gamma Radiation On Fibre Bragg Grating Sensors When Used As Radiation Dosimeters, Des Baccini

Theses : Honours

The effects of Gamma Radiation on Fibre Bragg Gratings (FBGs), when used as a radiation dosimeter, was proposed. The focus of this study centred on the FBG performance, and in particular the Bragg Wavelength Shift (BWS) whilst being exposed to ionizing radiation. Current research suggests that certain types of fibres manufactured by varying methods produce different results. The different responses to exposure from gamma irradiation between Germanium (Ge) doped optical fibres, with and without Hydrogen loading, along with the standard SMF-28 fibre with Hydrogen, were used and results noted and compared to previous work. The FBG’s in each fibre were …

Effect Of Thermal Annealing And Carbon Implantation On The Functional Properties Of Nanocomposite Tisin Coatings On Steel, Mohammad Shoeb Ahmed

Theses: Doctorates and Masters

This PhD research contributes to the part of advanced materials technology. The machining industry currently faces tremendous pressures with the need for durable cutting tools suitable for eco-friendly high speed machining operations becoming acute. In this thesis innovative design and synthesis strategies are explored to tailor the properties of nanocomposite coatings. Advanced characterisation techniques are applied to identify the mechanisms that control the mechanical, tribological, and corrosion behaviours of these coatings. Cutting tools protected by these coatings are anticipated to exhibit a unique combination of superior toughness and greater resistance to wear and corrosion, providing significant economic and environmental benefits. …

Characterising The Deformation Behaviour Of Human Tooth Enamel At The Microscale, Simona O'Brien

Theses: Doctorates and Masters

Enamel plays an important role in tooth function. Optimal combinations of composition and structure endow enamel with unique mechanical properties that remain largely unexplored. Specifically, more detailed understanding of the loadbearing ability of enamel is needed to mimic it synthetically and to design next generation biocomposite materials. This research investigates the variables that influence deformation behaviour of tooth enamel in relation to its hierarchical structure. Initially, a new method was developed for preparing flat, finely polished tooth samples that were maintained in their normal hydrated state for nanoindentation testing. In contrast to conventional methods, which commonly utilise either inappropriate or …

A Model For Systematically Investigating Relationships Between Variables That Affect The Performance Of Novice Programmers, Vivian Campbell

Theses: Doctorates and Masters

This research was motivated by an interest in novices learning to program

and a desire to understand the factors that affect their learning. The

traditional approach to performing such an investigation has been to select

factors which may be important and then perform statistical tests on a few

potential relationships. A new research model is proposed and tested to

ensure that a thorough and systematic investigation of the data is performed.

This thesis describes the data, defines the model and explains the

application and validation of the model.

The research process is managed by a control algorithm that is the …

Optimal Power Generation In Microgrids Using Agent-Based Technology, Thair Mahmoud

Theses: Doctorates and Masters

The existing power grids that form the basis of the respective electrical power infrastructures for various states and nations around the world, are expected to undergo a period of rapid change in the near future. The key element driving this change is the emergence of the Smartgrid. The Smartgrid paradigm represents a transition towards an intelligent, digitally enhanced, two-way power delivery grid. The aim of the Smartgrid is to promote and enhance the e_cient management and operation of the power generation and delivery facilities, by incorporating advanced communications, information technology, automation, and control methodologies into the power grid proper. Smartgrid's …

An Integrated Computer-Aided Modular Fixture Design System For Machining Semi-Circular Parts, Uday H. Farhan

Theses: Doctorates and Masters

Productivity is one of the most important factors in manufacturing processes because of the high level of market competition. In this regard, modular fixtures (MFs) play an important role in practically improving productivity in flexible manufacturing systems (FMSs) due to this technology using highly productive computer numerical control (CNC) machines. MFs consist of devices called jigs and fixtures for accurately holding the workpiece during different machining operations. The design process is complex, and traditional methods of MF design were not sufficiently productive.

Computer-aided design (CAD) software has rapidly improved as a result of the development of computer technology, and has …

Bit Error Rate Estimation In Wimax Communications At Vehicular Speeds Using Nakagami-M Fading Model, Biswojit Bose

Theses: Doctorates and Masters

The wireless communication industry has experienced a rapid technological evolution from its basic first generation (1G) wireless systems to the latest fourth generation (4G) wireless broadband systems. Wireless broadband systems are becoming increasingly popular with consumers and the technological strength of 4G has played a major role behind the success of wireless broadband systems. The IEEE 802.16m standard of the Worldwide Interoperability for Microwave Access (WiMAX) has been accepted as a 4G standard by the Institute of Electrical and Electronics Engineers in 2011. The IEEE 802.16m is fully optimised for wireless communications in fixed environments and can deliver very high …

Investigation On The Mobile Robot Navigation In An Unknown Environment, Ahmed S. Khusheef

Theses: Doctorates and Masters

Mobile robots could be used to search, find, and relocate objects in many types of manufacturing operations and environments. In this scenario, the target objects might reside with equal probability at any location in the environment and, therefore, the robot must navigate and search the whole area autonomously, and be equipped with specific sensors to detect objects. Novel challenges exist in developing a control system, which helps a mobile robot achieve such tasks, including constructing enhanced systems for navigation, and vision-based object recognition. The latter is important for undertaking the exploration task that requires an optimal object recognition technique.

In …

On A Joint Physical Layer And Medium Access Control Sublayer Design For Efficient Wireless Sensor Networks And Applications, Mahir Lumumba Meghji

Theses: Doctorates and Masters

Wireless sensor networks (WSNs) are distributed networks comprising small sensing devices equipped with a processor, memory, power source, and often with the capability for short range wireless communication. These networks are used in various applications, and have created interest in WSN research and commercial uses, including industrial, scientific, household, military, medical and environmental domains. These initiatives have also been stimulated by the finalisation of the IEEE 802.15.4 standard, which defines the medium access control (MAC) and physical layer (PHY) for low-rate wireless personal area networks (LR-WPAN).

Future applications may require large WSNs consisting of huge numbers of inexpensive wireless sensor …

Surface Plasmons For Enhanced Metal-Semiconductor-Metal Photodetectors, Ayman A. Karar

Theses: Doctorates and Masters

Surface Plasmon Polaritons (SPPs) are quantized charge density oscillations that occur when a photon couples to the free electron gas of the metal at the interface between a metal and a dielectric. The extraordinary properties of SPP allow for sub-diffraction limit waveguiding and localized field enhancement. The emerging field of surface plasmonics has applied SPP coupling to a number of new and interesting applications, such as: Surface Enhanced Raman Spectroscopy (SERS), super lenses, nano-scale optical circuits, optical filters and SPP enhanced photodetectors. In the past decade, there have been several experimental and theoretical research and development activities which reported on …

Silver (Ag) Nanoparticle Based Masks For The Development Of Antireflection Subwavelength Structures In Gaas And Si Solar Cells, Nazme A. Moushumy

Theses: Doctorates and Masters

This thesis focuses on the design and development of silver nanoparticles that can be used as masks for the development of antireflection subwavelength grating (SWG) structures. We particularly investigate the impact of silver thin film thickness and the effect of annealing temperature on the fabrication of silver nanoparticles of controlled size and spacing distributions. We also use these measured distributions to predict the performance of subwavelength grating structures developed using dry and isotropic etching of semiconductor substrates.

Silver (Ag) thin films of different thicknesses are deposited on Silicon (Si) and Gallium Arsenide (GaAs) semiconductor substrates and annealed at different temperatures. …