Engineering Commons^™

Denoising Techniques Reveal Neural Correlates Of Modulation Masking Release In Auditory Cortex, Sahil Chaubal

Theses

Hearing aids allow hearing impaired (HI) individuals to regain auditory perception in quiet settings. However, despite advances in hearing aid technology, HI individuals do not perform as well in situations with background sound as normally hearing (NH) listeners. An extensive literature demonstrates that when comparing tone detection performance in background noise, NH listeners have better thresholds when that noise is temporally modulated as compared to temporally unmodulated. However, this perceptual benefit, called Modulation Masking Release (MMR), is much reduced in HI listeners, and this is thought to be a reason for why HI listeners struggle in the presence of background …

Heat Transfer In Silicon - Experiments And Simulation, Chihlin Huang

Theses

The purpose of this thesis is to study the heat transfer in silicon. Silicon is the key semiconductor material, and thermal processing is the traditional method that is used in semiconductor processing. In this research, we can predict the temperature of the silicon wafer during heating. This ability to predict wafer temperature during semiconductor processing will facilitate in the following: (a) Process temperature uniformity, (b) Film thickness uniformity, (c) Diffusion, (d) Process yield, (e) Thermally induced stresses, and (f) Device yield - spatially and temporally across the wafer. For low temperature applications, IC chips can be modeled to simulate the …

Eis Analysis Of Shear Enhanced Microfluidic Lab-On-A-Chip Device, Mehnaz Mursalat

Theses

Electrochemical sensors and biosensors have received much attention owing to the feasibility demonstrated regarding instrumental simplicity, decent cost, and portability during the detection of a wide range of biological and pharmaceutical macromolecules. Carbon-based nanomaterials, including carbon nanotubes, have garnered tremendous interest for their unique thermal, mechanical, electronic and catalytic properties while designing these sensors. Whenever the macromolecules interact with a bio-recognition element on the electrode transducer surface, a measurable change in the electrical current or potential takes place. To achieve lower limits of detection, the use of sensor surfaces modified with nanostructured materials such as nanotubes, or nanoparticles is becoming …

Source-Channel Coding For Coordination Over A Noisy Two-Node Network, Sarah A. Obead

Theses

Recently, the concept of coordinating actions between distributed agents has emerged in the information theory literature. It was first introduced by Cuff in 2008 for the point-to-point case of coordination. However, Cuff’s work and the vast majority of the follow-up research are based on establishing coordination over noise-free communication links. In contrast, this thesis investigates the open problem of coordination over noisy point-to-point links. The aim of this study is to examine Shannon’s source-channel separation theorem in the context of coordination. To that end, a general joint scheme to achieve the strong notion of coordination over a discrete memoryless channel …

Novel Experimental Method For The Determination Of The Minimum Agitation Speed For Solids Suspension In Flat-Bottomed Stirred Tank Reactors, Shriarjun Shastry

Theses

Knowledge of the minimum agitation speed, Njs, required to suspend finely divided solids in vessels stirred by an impeller is a critical parameter to properly operate industrial tanks in a large number of industrial operations. The most common experimental approach to measure N_js is that of Zwietering’s (Chem. Eng. Sci., 1958, 8, 244-253), consisting of visually inspecting the tank bottom and visually determining the impeller agitation speed at which the solids are observed to rest on the tank bottom for no more than 1-2 seconds before being swept away. This method is quite reliable, but a method …

Real Time, Integrated, Paper Based Temperature Sensor For Lab On A Chip Device, Vignesh Shekhar

Theses

Temperature measurement and manipulation is a critical factor in a wide range of applications like Point Of Care Diagnostics (POC's), Polymerase Chain Reaction (PCR), Temperature Gradient Focusing (TGF) to cite few prominent examples. In the past decade, researchers have used various techniques to sense and control the temperature in microfluidic systems. The primary challenge has been the twin problem of integration and accuracy using minimal equipment while keeping it simple. In this study, an equipment free fabrication of the temperature sensor using filter paper impregnated with p-type colloidal PbS quantum dots is demonstrated. This sensor is later integrated into line …

Electrical, Electronic And Optical Properties Of Mos2 & Ws2, Weitao Tang

Theses

Two dimensional materials such as graphene, boron nitride and transition metal dichalcogenide (TMDCs) monolayers have arisen as a new class of materials with unique properties at monolayer thickness. Their electrical, electronic and optical properties are of great importance for a variety of applications in optoelectronics as light emitters, detectors, and photovoltaic devices. This work focuses on MoS₂ and WS₂, which are two important members of the TMDC class of materials. The properties of monolayer MoS₂ and WS₂ are investigated as well as the properties of bulk MoS₂ and WS₂ to provide an understanding …

Reliability Of Micro Mechanical Low Frequency Energy Harvesters For Implanted Cardiac Pacemakers, Sunny Jay

Theses

The aim of this project was to develop methods to assess the suitability and reliability of silicon-based piezoelectric micro-electro-mechanicai systems (MEMS) energy harvesters to capture the kinetic energy of the heartbeat in an implanted cardiac pacemaker. The major challenges of the work were that harvesters for vibration frequencies below 100 Hz have not been widely reported and the system requires reliable operation over a long lifetime. In this work device modelling was used for harvester design assessment. Experimental test methods and equipment were developed to produce data to validate the device models and to assess device reliability. A 2D analytical …

The Impact Of Drone Technology In Surveying In Ireland: An Examination Of The Accuracy Level Of Drones., Eleni Zintiridou

Theses

Abstract The society that we are living in could unquestionably be characterised as a community of technology. One of the most recent technological inventions is the drone, of which the usage is expected to triple by 2020, worldwide. Through the development and increasing popularity of the drones, the ability of latter to affect the surveying industry in Ireland has become a contemporary subject of study in the field of surveying, which is, however, in its infant stage. The presented dissertation is dealing with the ability of drones to impact the way that surveys are being conducted in Ireland, and also …

Development Of A Novel Kalman Filter Bank Predictor To Optimally Schedule The Renewable Energy Contribution Within A Micro-Grid, Conor Lynch

Theses

This PhD thesis presents a novel Kalman Filter Bank (KFB) methodology. The novel KFB is applied to predict and optimally schedule the operation of micro-grid energy resources with a public fixed-grid connection and an auxiliary battery storage backup facility. This methodology relies on a sliding single time step forecast projection to accurately acquire the anticipated schedule for a range of time dependent parameters, stochastic by nature, that have inherent embedded cyclical patterns. The innovative feature here consists of a novel bank of hourly adjacent Kalman Filter estimators, which operate in synchronism, for accurate parameter prediction over a selected time horizon. …

Development Of A Dynamic Cfd Model For Offshore Oscillating Water Columns With Non-Linear Interactions, Ken O'Connell

Theses

This thesis focuses on the development of a state of the art modelling technique for offshore Oscillating Water Column (OWC) type Wave Energy Converters (WEC) using Computational Fluid Dynamics (CFD). Current literature indicates a limited amount of work has been completed on studying these devices containing non-linear time dependent flow phenomenon. Initially, a 2D Numerical Wave Tank (NWT) is studied to reduce discretisation error in order to reproduce accurately propagating waves. Further development into a 3D domain permits the geometrical requirements of an OWC type spar buoy to be included.

In parallel, a single Degree of Freedom (DOF) model is …

Development & Validation Of An Improved Biomechanical Model For Motion Analysis, Darren Dawson

Theses

Three dimensional motion analysis systems are utilised across a number of different disciplines, including clinical gait analysis, sports performance studies and analysis of tasks of daily living. These systems utilise biomechanical models which define body segment coordinate systems and calculate kinematic and kinetic relationships about the joints between adjacent coordinate systems. In this study, a biomechanical model for general use in motion analysis was developed and validated. It was designed to improve upon the accuracy and capability of currently available models. The newly developed model utilises state of the art techniques to accurately define body segment coordinate systems. Accurate predictive …

Semiconductor Materials And Devices For 2 Micron Generation, Dzianis Saladukha

Theses

In the last century, semiconductor research has led to significant changes in the fields of communication, medicine, the environment, and many others. Semiconductor devices provide a relatively simple and effective way to convert electrical energy to light and vice versa. Devices based on semiconductor materials of various kinds provide interaction of an electromagnetic signal in the range of wavelengths with a medium. Examples of such devices are LED lamps, photovoltaic cells, thermometers, gas sensors, cameras, and many others. The study of various semiconductors broadens the range of application of photonics. This work is based on the study of materials which …

Strategically Managing Product Innovation To Create Consumer Value: An Analysis In The Context Of The Australian Electric Vehicle Market, Brendan Koehler

Theses

This thesis encompasses a body of research which looks to explore how strategic management, consumer value and product innovation interrelate. In particular, this research will evaluate such a unilateral relationship in specific reference to product innovations developed as a result of emerging and disruptive technology. Therefore, this research will be conducted in the context of the Australian electric vehicle industry. This industry was selected as it has displayed traits of an industry with companies that have a desire to incorporate electric vehicle product innovations into their portfolio from a strategic perspective; yet these product innovations have no particular consumer demand …

An Investigation Of Service Quality Within Irish Franchised Motor Dealerships, Clive Atkinson

Theses

This study investigates service quality within franchised motor dealerships from the perspective of thirty-eight persons working in the roles of Dealer Principal, After-Sales Manager or Service Manager in dealerships operating under the Volkswagen group of brands in Ireland (VW, Audi, SEAT and Skoda). With approximately 2.3 million cars on Irish roads, more than two thirds of the Irish adult population encounter car service experiences on a regular basis. Regardless of brand or dealership type, the quality of vehicle service experience is paramount for customer retention. Despite this, however, service quality within Irish motor dealerships remains an under-explored area. Qualitative analysis …

Investigating The Parameters That Influence The Particle Mass Concentration Rates In A Grade C Cleanroom., Nazar H. Baker

Theses

The cleanroom design engineers use the guidelines tables, in which the Air Change Rates (ACHs) are determined based on the room cleanliness class. These guidelines are based on experience and do not fully address many other critical variables that influence the particulate level and particle distribution. These simplified approaches could often cause significant energy waste. In the last five decades, a number of mathematical models were developed to determine the airflow required in cleanrooms. As a consequence of the approximation of many critical variables in these models, these models can only be used as a qualitative indicator of the airflow …

Behavior Of Double-Sided Concrete Corbels Reinforced With Glass-Fiber Reinforced Polymer Bars, Ayman Farid Abu Obaida

Theses

Steel reinforced concrete members with small shear span-to-effective depth ratios (a/d), such as corbels; have many classical applications, mostly in tall building, precast structures, factory buildings, bridges, and foundations. Despite extended research works on the performance of such members, little information is available on the performance of these members when reinforced totally with internal fiber reinforced polymer (FRP) bars. The use of FRP bars in reinforcing concrete members would eliminate corrosion problems thus increasing the service life of the structure. This thesis aims at investigating the shear strength of double-sided concrete corbels reinforced with glass-fiber reinforced polymer (GFRP) bars. The …

Design, Fabrication And Characterization Of Low­ Power Gas Sensors Based On Organic-Inorganic Nano-Composition, Ayah Faeik Salim Abu Hani

Theses

Lower power consumption and higher performance are compelling demands in the electronic systems motivating the search for new materials, which are capable of fulfilling these demands. Recently, nanomaterial-based sensor technology has drawn considerable attention towards the development of sensing applications such as H2S gas sensors. Development of H2S gas sensors is crucial due to its extreme toxicity and damaging effects on both health and environment. This thesis aims to develop H2S gas sensors with enhanced sensitivity, flexibility, lower operating temperature, and high selectivity.

The proposed sensors present a contribution to the field of nano-electronics. They are designed based on the …

Performance Of Continuous Concrete Slabs Reinforced With Hybrid Steel-Basalt Bars, Mohammad Sohayeb Akiel

Theses

Continuous steel-reinforced concrete structures are vulnerable to corrosion

Damage when exposed to harsh environment. Although replacing conventional steel entirely with basalt fiber-reinforced polymer (BFRP) bars can eliminate corrosion problems, the lower modulus of elasticity of BFRP would reduce serviceability of the structure. The use of hybrid steel-BFRP bars rather than BFRP bars only has a potential to improve the serviceability of continuous concrete

Structures without reducing the deformation capacity. Through experimental testing and numerical simulation, this work aims to examine the structural behavior of two-span concrete specimens internally reinforced with BFRP or hybrid steel-BFRP bars.

A total of 12 two-span …

An Islanding Detection Method For Micro-Grids With Grid-Connected And Islanded Capability, Hasna Mubarak Saleh Ai Seiari

Theses

With the increasing prevalence of renewable energy and distributed generation (DG) in distribution systems, micro-grids are becoming more popular and an attractive option for enhancing system operation and reliability. This can be attributed to the micro-grid ability to operate in both connected and disconnected modes. Equally important, micro-grids are the best solution to meet the increasing demand of electric power in a cost effective manner due to the close proximity to the load demand and thus minimizing system losses. Islanding detection methods have been proposed for inverter based distributed generation with only grid-connected capability. Micro-grids are composed of DGs that …

Effect Of Melt Method On Thoracolumbar Connective Tissue, Faria Sanjana

Theses

Approximately, 31 million adults in the United States suffer from low back pain (LBP). Altered connective tissue structure has been identified in adults with chronic LBP. Numerous novel treatments are being developed targeting the connective tissue and nervous system to relieve people from LBP. One such self-care treatment is the MELT method. The objective of this study was to determine whether thickness of thoracolumbar connective tissue and other biomechanical and viscoelastic properties of myofascial tissue in the low back region change in subjects with chronic LBP as a result of MELT.

Using ultrasound imaging and an algorithm developed in MATLAB, …

Effect Of Temperature On The Fracture Behavior Of Lead-Free Solder Joints, Patrick Thompson

Theses

The objective of the present study is to examine the effect of temperature on the fracture behavior of Cu-SAC305-Cu joints. To this end, double cantilever beam (DCB) specimens, consisting of a thin layer of Sn96.5Ag3.0Cu0.5 (SAC305) solder sandwiched between two copper bars, fabricated under standard surface mount (SMT) processing conditions are fractured under various temperatures with a MTS machine equipped with an environment chamber. The load-displacement behavior corresponding to crack initiation and the subsequent toughening before ultimate failure and the displacements near crack tip are recorded and used to calculate the fracture energy release rates. The fracture surfaces and the …

Preparation, Ignition And Combustion Of Reactive Metal-Sulfur Nanocomposites, Ziyue Zhong

Theses

Mechanical milling is applied to synthesize reactive metal-sulfur nanocomposites. Specifically, magnesium-sulfur, aluminum-sulfur and zirconium-sulfur nanocomposite powders are prepared. Each powder particle contained homogeneously mixed sulfur and respective metal. These materials are expected to be stable in room air. They are also expected to release sulfur upon ignition; the released sulfur may serve as a biocidal agent. The ignition temperatures of the three prepared sulfur-bearing materials fall in a range of 750 - 1000 K. All prepared materials are successfully ignited in electrostatic discharge experiment as well as in a constant volume explosion experiment. The most sensitive material to spark ignition …

Continuum Mechanical Analysis Of Space And Time Dependent Deformation Pattern Of Brain With Blunt Injury, Chen Miao

Theses

Deformation of human brain due to acceleration impact has been widely accepted as the direct connection to the Trauma Brain Injury (TBI). However, the limitation of obtaining deformation data of TBI is a major obstacle to understanding TBI mechanism. This experiment mainly focuses on developing a method to measure deformation pattern of brain with blunt injury. First of all, displacement data of markers on sagittal plane of an injury head model was collected using 3D reconstruction software after an impact test. Second, the displacement data was used to calculate 2D Lagrangian strain tensor and the principal strain. The temporal and …

Optimum Distance Between Ground Base Stations For High-Speed Train Communications Using Free-Space Optical Laser Links, Sina Fathi Kazerooni

Theses

High-Speed trains (HSTs) can travel at speeds up to 430 Km/h. The increasing adoption rate of HSTs, and large number of Internet-connected digital devices, pose a great demand for a fast and reliable Internet connection in high-speed trains. Different radio-frequency (RF) wireless communication systems have been studied for HSTs. However, RF wireless communications in high-speed mobility environments suffer from frequent handovers, penetration loss, and Doppler effect. These problems promote the use of other technologies such as free-space optical (FSO) communications to provide reliable Internet connection for HST’s passengers.

Two different approaches for performing signal handover using FSO technology for ground …

An Electromechanical System For Characterization Of Piezoelectric Materials, Ahmet Sait Asan

Theses

Piezoelectric materials have been used in medical applications for a long time due to their unique characteristics, which is to respond to mechanical stimulation by producing an electrical current and vice versa. They perform a pivotal role in medical applications both for diagnostic and therapeutic purposes. In this regard, characterizing the piezoelectric properties of these materials is crucial for their usage. In this particular study, an electromechanical system for measurement of piezoelectric output signals is designed and tested. The project is motivated by the question: can the piezoelectric properties be characterized by applying different mechanical stimulation waveforms and frequencies. Two …

Infrared Imaging - Case Studies And Applications, Shuang Du

Theses

Recent advancements in the manufacture of solid state detectors have led to significant improvements in the use and applications of infrared (IR) imaging. Compared with traditional imaging in visible light, infrared imaging has abilities to convey significant additional information. Applications in medicine require wavelengths in the range of 0.8 to 25 microns while metrology and astronomy, traditionally, require wavelengths in the range of 25 microns to 1 mm.

In this study, infrared imaging has been used as a tool to characterize a variety of objects and systems. Some of these case studies have been considered under conditions of thermodynamic non-equilibrium. …

Diffusivity Of Drug Actives In Transdermal Drug Delivery (Tdd), Natali R. Gendelberg

Theses

Transdermal Drug Delivery (TDD) through skin patches has many advantages including the following: slow and continuous administration of the therapeutic over long periods of time, timely dosage, accessibility, kinetic maneuverability, elimination of the “First Pass Effect” and negative side effects on the digestive tract. All of the above justify investment into further development of TDD therapies, despite the skin permeability restrictions posed on size and charge by the skin. As skin permeability varies between all individuals based on age, ethnicity and lifestyle, the determination of the proper drug dosages to be contained in the skin patch is highly reliant on …

Antibacterial Efficacy Of Nanometals In Conjunction With Electrical Stimulus, Syed A. Hussain

Theses

Hospital related infections generally result from the combined effect of preexisting bacteria on the patient and invasive devices. This demonstrates the significance in improving these medical devices to increase the quality of life of the patients that require them. This study will attempt to evaluate the antibacterial efficacy of nanocopper particles and an electrical stimulus for the usage in medical device development and the hospital environment.

For devices such as catheters, infections typically result from bacteria entering the body from the outside. This is accomplished by bacteria attaching themselves to the exterior of the device and producing biofilm which allows …

Response Of Stretch-Injured Schwann Cells, Stephanie Iring

Theses

Axon fibers are covered by myelin sheath. After axonal damage, demyelination follows with the production of debris. In the Central Nervous System many studies have been performed to observe and analyze stretch injured axons, but very little has been done to study the white matter axonal tracts, oligodendrocytes. Schwann cells can help take a first look into stretch injured glia cells from the Peripheral nervous system. In order to observe changes in Schwann Cells a stretch injury device is used to produce the effects of severe and moderate injuries. Schwann Cells are stretch injured in both their undifferentiated and differentiated …