Digital Commons Network^™

Nano-Patterned High-Responsivity Gaas Metal-Semiconductor-Metal Photodetector, Ayman Karar, Chee Leong Tan, Kamal Alameh, Yong Tak Lee

Research outputs 2011

In this paper, we use the finite difference time-domain (FDTD) method to optimize the light absorption of an ultrafast nano-grating plasmonic GaAs metal-semiconductor-metal photodetector (MSM-PD) employing double metal nano-gratings. The geometry of the MSM-PD is theoretically investigated, leading to improved light absorption near the design wavelength of GaAs due to plasmon-assisted electric and magnetic field concentration through a subwavelength aperture. Simulation results show up to 8- and 21-times light absorption enhancement for the single and double nano-grating structure, respectively, in comparison to conventional MSM-PDs. Experimentally, more than 4 times enhancement in photocurrent is demonstrated for a single top nano-grating MSM-PD …

Secondary Students Research Projects In Engineering: Optical Fibre Bragg Grating Sensor Applications, Steven Hinckley, Graham Wild

Research outputs 2011

In this paper, we present a study of secondary student research projects on fibre Bragg grating (FBG) based optical fibre sensors. Our study has shown that simple experimental procedures can be developed and implemented by students with minimal prior knowledge. In these experiments, students gain a significant understanding of FBG properties and performance, as well as an understanding of research, data analysis and communications skills required by researchers. Student satisfaction and enjoyment with the programme is very high, based on feedback received. These research-based projects would be ideal for implementation into undergraduate engineering learning programmes.

Stabilisation Of Linear-Cavity Fibre Laser Using A Saturable Absorber, David Michel, Feng Xiao, Kamal Alameh

Research outputs 2011

We investigate the optimisation of the length of an un-pumped erbium doped fibre (EDF) in order to suppress amplifier noise in a linear-cavity fibre laser structure. The experimental results demonstrate the existence of an optimum length of the un-pumped EDF which eliminates noise due to high optical pumping powers, thus leading to a stable laser output.

Modelling Small-Scale Stand-Alone (Pv) Energy Systems With Reverse Osmosis Integration, Daniel Clarke, Yasir Al-Abdeli, Ganesh Kothapalli

Research outputs 2011

Australia has a vast land mass characterised by more than 35,000km of shore-line and an abundance of renewable sources (e.g., solar and wind en ergy). Despite the existence of much potential to utilise sustainable pathways of power generation, ther e remains a general reliance on electricity generated from larger plants which are mostly grid-connected but fossil-fuel operated. In Western Australia, only a fraction of its coastal areas and inland mass is serviced by the South West Interconnected (grid) System. For the majority of its regional commun ities, decentralised power generati on forms the prime source of power provision. This exacerbates …

Garnet Multilayer Thin Film Structure With Magnetostatically-Altered And Improved Magnetic Properties Prepared By Rf Magnetron Sputtering, Mohammad Nur-E-Alam, Mikhail Vasiliev, Viacheslav Kotov, Kamal Alameh

Research outputs 2011

We prepare an all-garnet multilayer film structure by sandwiching a magneto-soft garnet material in between two magneto-hard garnet materials with high bismuth substitution levels using RF magnetron sputtering technique and investigate the microstructure and the effects of magnetostatic inter-layer coupling on magnetic properties. Both types of the Bi-substituted magneto-optic garnet materials used possess excellent optical, magnetic and magneto-optical properties suitable for the application in different new and emerging technologies in optics and photonics. Garnet layers of composition type Bi2Dy1Fe4Ga1O12 have strong perpendicular magnetic anisotropy and Bi1.8Lu1.2Fe3.6Al1.4O12 magneto-soft layer features magnetization behavior similar to that of in-plane magnetized films. The all-garnet …

Design Of Laser Multi-Beam Generator For Plant Discrimination, Sreten Askraba, Arie Paap, Kamal Alameh, John Rowe

Research outputs 2011

Optimisation of the optical signal from the laser multi-spot beam generator employed in a photonic based real-time plant discrimination sensor for use in selective herbicide spraying systems is presented. The plant detection sensor uses a three-wavelength laser diode module that sequentially emits identically-polarized laser light beams through a common aperture, along one optical path. Each laser beam enters a multi-spot beam generator which produces 15 parallel laser beams over a 240mm span. The intensity of the reflected light from each spot is detected by a high-speed line scan image sensor. Plant discrimination is based on calculating the slope of the …

Computer Based Experiments For Off-Campus Teaching And Learning Of Ac Electricity, Graham Wild, Geoffrey Swan, Steven Hinckley

Research outputs 2011

In this work, we show the implementation of a computer based Digital Storage Oscilloscope (DSO) and Signal Generator (SG), using the computers soundcard for off- campus AC electronics experiments. The microphone input is used for the DSO, and the speaker jack is used as the SG. In an effort to reduce the cost of implementing the experiment, we examine software available for free online. A small number of applications were compared in terms of their interface and functionality, for both the DSO and SG. With the choice of a suitable app for both the input and the output, simple AC …

Simulation Of A Mobile Robot Navigation System, Ahmed Khusheef, Ganesh Kothapalli, Majid Tolouei Rad

Research outputs 2011

Mobile robots are used in various application areas including manufacturing, mining, military operations, search and rescue missions and so on. As such there is a need to model robot mobility that tracks robot system modules such as navigation system and visi on based object recognition. For the navigation system it is important to locate the position of the robot in surr ounding environment. Then it has to plan a path towards desired destination. The navigation system of a robot has to identify all potential obstacles in order to find a suitable path. The objective of this research is to develop …

A 1x4 Adaptive Optical Splitter Based On Opto-Vlsi Processor, Haithem Mustafa, Feng Xiao, Kamal Alameh

Research outputs 2011

We propose and experimentally demonstrate a novel high resolution 1×4 adaptive optical power splitter based on the use of an Opto-VLSI processor and a 4-f imaging system with an optimized optical beam waist profile. By uploading optimized multicasting phase holograms onto the software-driven Opto-VLSI processor, an input optical signal is dynamically split into different output fiber ports with user-defined splitting ratios. Experimental results showing dynamic optical splitting over a wavelength range exceeding 50 nm are presented.

Transmission Improvement Of Umts And Wi-Fi Signals Through Energy Saving Glass Using Fss, Irfan Ullah, Xiaoli Zhao, Daryoush Habibi, Ghaffer I. Kiani

Research outputs 2011

The transmission of infrared (IR) and visible frequencies through modern energy-saving glass, due to etching of bandpass frequency-selective surfaces (FSSs), is analysed. Energy-saving glass panels employ a very thin layer of metallic oxide on one side of the ordinary glass. Due to the presence of this layer, IR waves are attenuated whereas visible wavelengths can pass through, providing good see-through effect. However, one drawback with such energy-saving glass panels is that they also attenuate useful radio frequency (RF)/ microwave (MW) signals such as those used for mobile (e.g. global system for mobile communication (GSM)), global positioning system (GPS) and personal …

Theory Of The Scattering Of Light And Surface Plasmon Polaritons By Finite-Size Subwavelength Metallic Defects Via Field Decomposition, Guangyuan Li, Feng Xiao, Lin Cai, Kamal Alameh, Anshi Xu

Research outputs 2011

A theoretical model is presented for the scattering of light and surface plasmon polaritons (SPPs) by finite-size subwavelength metallic defects. Based on the decomposition of the scattered fields into SPPs and quasi-cylindrical waves (CWs), an SPP–CW model is developed to depict the multiple scattering of SPPs and CWs in finite-size defects using the elementary scattering processes in a single one. The involved elementary scattering of the CW, as well as the CW-related coefficients, which are difficult or even impossible to define and calculate according to classical scattering theory, is clarified. A close relationship between the scattering coefficients of the SPP …

Power Quality Improvement In Autonomous Microgrid Operation Using Particle Swarm Optimization, Waleed Al-Saedi, Stefan W. Lachowicz, Daryoush Habibi, Octavian Bass

Research outputs 2011

This paper presents an optimal power control strategy for an autonomous microgrid operation based on a real-time self-tuning method. The purpose of this work is to improve the quality of power supply where Distributed Generation (DG) units are connected to the grid. Dynamic response and harmonics distortion are the two main performance parameters which are considered in this work, particularly when the microgrid is islanded. The controller scheme is composed of an inner current control loop and an outer power control loop based on a synchronous reference frame and the conventional PI regulators. Particle Swarm Optimization (PSO) is an intelligent …

Photonic Microwave Filter Employing An Opto-Vlsi-Based Adaptive Optical Combiner, Haithem Mustafa, Feng Xiao, Kamal Alameh

Research outputs 2011

A reconfigurable photonic microwave filter structure employing an Opto-VLSI based adaptive optical combiner is proposed and experimentally demonstrated. The Opto-VLSI based adaptive optical combiner is used to combine RF modulated optical signals with a user-defined weight profile to realize a reconfigurable RF photonic filter response. Theoretical simulations are in excellent agreement with the experimental results that demonstrate the concept of the photonic microwave filter structure.

Numerical Modelling Of Interrogation Systems For Optical Fibre Bragg Grating Sensors, Daniel P. Oswald, Steven J. Richardson, Graham Wild

Research outputs 2011

There are a number of interrogation methods that can be used in optical Fibre Bragg Grating (FBG) sensing system. For very high frequency signals interrogating the sensor signal from an FBG is limited to two intensiometric methods, edge filter detection and power detection. In edge filter detection, a broadband light source illuminates an FBG, the reflected spectrum is then passed through a spectral filter. In power detection, a narrowband light source with a wavelength corresponding to the 3dB point of the FBG is filtered by the FBG itself. Both methods convert the spectral shift of the FBG into intensity signals. …

Tuning Fuzzy Systems To Achieve Economic Dispatch For Microgrids, Thair Mahmoud, Daryoush Habibi, Octavian Bass, Stefan W. Lachowicz

Research outputs 2011

In this paper, a Tuning Fuzzy System (TFS) is used to improve the energy demand forecasting for a medium-size microgrid. As a case study, the energy demand of the Joondalup Campus of Edith Cowan University (ECU) in Western Australia is modelled. The developed model is required to perform economic dispatch for the ECU microgrid in islanding mode. To achieve an active economic dispatch demand prediction model, actual load readings are considered. A fuzzy tuning mechanism is added to the prediction model to enhance the prediction accuracy based on actual load changes. The demand prediction is modelled by a Fuzzy Subtractive …

Universal Design Of Transportation Systems: A Case Study Of Access And Mobility Of People With Disabilities At Selected Intersections In Dar Es Salaam, Nurdin Mushule

Tanzania Journal of Engineering and Technology (TJET)

The pedestrian facilities at intersections must be usable by pedestrians of all ages and capabilities. Intersections in particular must be designed to safely accommodate pedestrians of all ages and physical and mental abilities. Often, however, intersection designs fail to accommodate people with visual and mobility disabilities. In this regard, for pedestrians with disabilities, intersections can prove to be a challenge. Some of those challenges include provision of insufficient pedestrian clearance time due to use of inappropriate design pedestrian speed. Most importantly, the required facilities to enable People With Disabilities (PWD) to use the intersection without hindrance may be missing. Obstacles …

A Multicriteria Based Quantitative Framework For Assessing Sustainability Of Pile Foundations, Aditi Misra

Master's Theses

ABSTRACT

Civil Engineering is the major instrument of anthropocentric development over centuries through ever expanding infrastructure, cities and facilities.  Civil engineering processes are both resource and fuel intensive.  The building industry alone, during the construction stage, uses about 30-40% of the total resources used in the industrialized countries.  There is a growing consensus that delivering a sustainable built environment starts with incorporating sustainability thoughts at the planning and design stages of a project.  Geotechnical engineering is most resource intensive although this intensive consumption of energy goes unnoticed mainly because of the indirect nature of the energy used in the …

An Integrated Approach For Phytate Degradation And Recovery Of Myo-Inositol And Phosphate As Valued-Added Products From The By-Products Of Corn Ethanol Industry, Jun Dang

Department of Chemical and Biomolecular Engineering: Dissertations, Theses, and Student Research

An integrated process was developed to hydrolyze the phytates in light steep water (LSW) and to simultaneously isolate inorganic phosphate (Pi) and myo-inositol products. The proposed integrated process is helpful in resolving the environmental and nutritional concerns in the use of corn gluten feed (CGF) in the animal diets. This process comprised of partial and total hydrolysis of LSW and intermediate anion exchange separation technique. The phytates in LSW were initially degraded to negatively charged myo-inositol phosphates (InsP₂ - InsP₅). The optimized experimental parameters for the partial hydrolysis of LSW were determined to be 2 h hydrolysis …

Florida Weatherization Training - Quarterly Report (October 2010-December 2010), Florida Solar Energy Center, Neil Moyer

FSEC Energy Research Center®

The weatherization training for the State of Florida Dept of Community Affairs continues at the Florida Solar Energy Center's Training Facility. Progress for the sixth three months of the contract included a five day classroom training on October 18-22 (17 students) and in-field evaluations (16 students).

Distributed Grid Intelligence For Future Microgrid With Renewable Sources And Storage, Fanjun Meng, Ravi Akella, Mariesa L. Crow, Bruce Mcmillin

Electrical and Computer Engineering Faculty Research & Creative Works

The FREEDM microgrid is a smart grid solution with Distributed Grid Intelligence (DGI) to efficiently manage the power distribution and storage of renewable energy. within the FREEDM system, DGI applies distributed control method in a unique way to achieve feasible load balancing in microgrid by migrating power between renewable energy generation and storage at each node. This paper presents the key aspects in implementing such a scheme and outlines the preliminary results obtained by integrating the proposed methodology. the results demonstrate the potential benefits of adopting DGI control on a microgrid.

Improving The Emulsion Stability Of Sponge Cake By The Addition Of ?-Polyglutamic Acid, Yung-Shin Shyu, Wen-Chieh Sung

Journal of Marine Science and Technology–Taiwan

The batter properties of sponge cake with the addition of γ-polyglutamic acid (PGA) at different levels (0.05, 0.1, 0.5 gkg-1, w/w) was evaluated. The viscosity, emulsion stability and foam stability increased at the addition of 0.5 gkg-1 PGA level. PGA caused significant declines in the differential scanning calorimetry (DSC) enthalpy, onset and peak temperatures of ice-melting transition of sponge cake. Sponge cakes manufactured with 0.5 gkg-1 PGA addition were in general lighter on crumb color and white index than the control. Scanning electron microscopy showed that sponge cake with the addition of 0.1 and 0.5 gkg-1 PGA exhibited microstructures having …

Evaluation Of Hydraulic Efficiency Of Disinfection Systems Based On Residence Time Distribution Curves, Jordan M. Wilson, Subhas K. Venayagamoorthy

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Hydraulic efficiency is a vital component in evaluating the disinfection capability of a contact system. Current practice evaluates these systems based upon the theoretical detention time (TDT) and the rising limb of the residence time distribution (RTD) curve. This evaluation methodology is expected because most systems are built based on TDT under a "black box" approach to disinfection system design. Within recent years, the proliferation of computational fluid dynamics (CFD) has allowed a more insightful approach to disinfection system design and analysis. Research presented in this study using CFD models and physical tracer studies shows that evaluation methods based upon …

Incorporating Feedback From Multiple Sensory Modalities Enhances Brain–Machine Interface Control, Aaron J. Suminski, Dennis C. Tkach, Andrew H. Fagg, Nicholas G. Hatsopoulos

Biomedical Engineering Faculty Research and Publications

The brain typically uses a rich supply of feedback from multiple sensory modalities to control movement in healthy individuals. In many individuals, these afferent pathways, as well as their efferent counterparts, are compromised by disease or injury resulting in significant impairments and reduced quality of life. Brain–machine interfaces (BMIs) offer the promise of recovered functionality to these individuals by allowing them to control a device using their thoughts. Most current BMI implementations use visual feedback for closed-loop control; however, it has been suggested that the inclusion of additional feedback modalities may lead to improvements in control. We demonstrate for the …

Modeling Of Aortic Valve Anatomic Geometry From Clinical Multi Detector-Row Computed Tomography Images, Gregory A. Book

Master's Theses

Transcatheter aortic valve implantation (TAVI) is an emerging and viable alternative to surgical valve replacement. A TAVI procedure involves insertion of a catheter into the heart through an artery or transapically, and expanding valve stent in place. This procedure dramatically reduces the recovery time by eliminating the need for open heart surgery. Understanding the biomechanics of the stent-valve interaction is crucial for proper device deployment and function. In this study, we examine the extraction of valve geometries and creation of valve models from multi-detector row computed tomography (MDCT) images that may eventually be used to model stent expansion on a …

4-D Modeling Of Displacement Vector Fields For Improved Radiation Therapy, Elizabeth Zachariah

Theses and Dissertations

In radiation therapy, it is imperative to deliver high doses of radiation to the tumor while reducing radiation to the healthy tissue. Respiratory motion is the most significant source of errors during treatment. Therefore, it is essential to accurately model respiratory motion for precise and effective radiation delivery. Many approaches exist to account for respiratory motion, such as controlled breath hold and respiratory gating, and they have been relatively successful. They still present many drawbacks. Thus, research has been expanded to tumor tracking. This paper presents a spatio-temporal model for four dimensional CT reconstruction. The method begins with a set …

Synthesis And Characterization Of Electrospun Gelatin/Dendrimer Scaffold Encapsulated With A Silver As A Potential Antimicrobial Wound Dressing, Alpana Dongargaonkar

Theses and Dissertations

A novel nanofiber scaffold was fabricated and characterized as a potential antimicrobial wound dressing. Half generation polyamidoamine (PAMAM) dendrimer G3.5 was covalently conjugated to gelatin. Gelatin alone or with gelatin-dendrimer conjugates was electrospun into nanofiber scaffolds. Gelatin is a derivative of natural collagen, and it is biocompatible, non-toxic and inexpensive, making it a desirable component in a wound dressing. Dendrimers are synthetic polymers comprising of a central core, internal branches and reactive surface groups. They provide a structurally controlled architecture for drug release. Silver was incorporated into the scaffold in situ due to its broad spectrum of antimicrobial properties. The …

Development Of Electroencephalography Based Brain Controlled Switch And Nerve Conduction Study Simulator Software, Kai Qian

Theses and Dissertations

This thesis investigated the development of an EEG-based brain controlled switch and the design of a software for nerve conduction study. For EEG-based brain controlled switch, we proposed a novel paradigm for an online brain-controlled switch based on Event-Related Synchronizations (ERDs) following external sync signals. Furthermore, the ERD feature was enhanced by 3 event-related moving averages and the performance was tested online. Subjects were instructed to perform an intended motor task following an external sync signal in order to turn on a virtual switch. Meanwhile, the beta-band (16-20Hz) relative ERD power (ERD in reverse value order) of a single EEG …

Voltage Prediction Using A Cellular Network, Lisa L. Grant, Ganesh K. Venayagamoorthy

Electrical and Computer Engineering Faculty Research & Creative Works

Better identification tools are needed for power system voltage profile prediction. the power systems of the future will see an increase in both renewable energy sources and load demand increasing the need for quick estimation of bus voltages and line power flows for system security and contingency analysis. a Cellular Simultaneous Recurrent Neural Network (CSRN) to identify and predict bus voltage dynamics is presented in this paper. the benefit of using a cellular structure over traditional neural network architectures is that the network can represent a direct mapping of any power system allowing for easier scalability to large power systems. …

Integrating Balanced Scorecard And Simulation Modelling To Improve Emergency Department Performance In Irish Hospitals, Amr Arisha, Waleed Abo-Hamad, Khaled Ismail

Conference papers

In the healthcare sector, there is a requirement for innovative solutions in managing the high levels of complexity and uncertainty within Emergency Departments (EDs). Simulation modeling is currently seen as a competent means of analyzing EDs, which allows changes effects to be understood and predicted more easily. The Balanced Scorecard (BSC), well-known performance management concept, has become a steering method in approaching new improvement cycles. This paper presents a methodology that integrates BSC and simulation modeling to improve the performance of ED in a University Hospital in North Dublin. BSC design began with understanding patient's needs, ED activities, as well …

Network Science: Using Information Technology To Enable Collaboration, Arden L. Bement Jr.

PPRI Digital Library

No abstract provided.