Engineering Commons^™

Power Dissipation And Power Correlations For A Retreatblade Impeller Under Different Baffling Conditions, Chadakarn Sirasitthichoke

Theses

Glass-lined stirred reactors and tanks are commonly used in the pharmaceutical industry because of their corrosion resistance, ease of cleanliness and minimization of product contamination. Most industrial glass-lined tank reactors are provided with a torispherical tank bottom and a retreat curve impeller with low impeller clearance from the vessel bottom. The power, P, dissipated by the impeller is a critical process parameter to mixing processes to achieve the desired mixing effect, especially since the power per unit volume, P/V, directly controls mass transfer processes and other mixing phenomena. However, little information has been published about the power dissipation and the …

Oil Recovery By Surfactant Flooding; Sensitivity Analysis To Technical Parameters And Economic Analysis, Hadel Mohsen Moustafa

Theses

Various enhanced oil recovery methods including miscible gas injection, chemical, thermal and other methods are applied at the third phase of production after the primary and secondary recovery have been exhausted. Surfactant flooding is one of the chemical methods that is capable of recovering more oil by decreasing the IFT and/or wettability alteration.This piece of work aims to asses and select the development options using surfactant process that maximize oil recovery for a synthetic reservoir model by optimizing technical and economic analysis.

Reservoir simulation study using ECLIPSE 100 was used to study the different development options of surfactant flooding applied …

Durability Of Glass Fiber-Reinforced Polymer Bars In Seawater-Contaminated Concrete, Abdelrahman A. E. Alsallamin

Theses

This research aims to investigate the durability performance and microstructure characteristics of two different types of glass fiber-reinforced polymer (GFRP) bars in severe environment. GFRP bars encased in seawater-contaminated concrete were immersed in tap water for 5, 10, and 15 months at temperatures of 20, 40, and 60°C. Half of the specimens were conditioned under a sustained load of 25% of their ultimate strength whereas the other half was conditioned without load. Following conditioning, the GFRP bars were retrieved then tested to failure under uniaxial tension. Microstructure analysis was performed by employing differential scanning calorimetry (DSC), Fourier transform infrared (FTIR) …

Evaluation Of Electrocoagulation For Chloride And Ammonium Removal From The Reject Brine Effluent Pretreated By Solvay Process, Miada Abubaker Ali

Theses

Excessive use of desalination, due to the increase in freshwater demand, results in large productions of reject brine. Therefore, the development of an efficient treatment process of the reject brine becomes vital. The Solvay process is one of the main treatment technologies, wherein NH₃ is introduced to convert soluble Na⁺ into insoluble NaHCO₃. However, in this process, Cl^- is not removed and NH₄⁺ is introduced, and therefore electrocoagulation has been proposed for their removal. The experiment was designed using Minitab with different initial concentrations of chloride (7400 – 32600 mg/l), current densities (0.033 …

Urban Park Design, Level Of Enclosure And People’S Satisfaction: A Comparative Analysis Of Al Jahili And Al Selimi Parks In Al Ain, Uae, Amnah Ali S Gargoum

Theses

The purpose of this research is to understand how physical characteristics of parks with a particular focus on different levels of enclosure affect park usage level and user patterns in the city of Al-Ain, UAE. Parks in Al Ain are present in different parts of the city and provide plenty of opportunities for leisure and recreation. Despite this diversity, parks located within the inner city area remain the most popular among the residents of Al-Ain, and have expanded significantly in the last few years. Specifically, this thesis aims to understand how the levels of usage and the behavioral patterns of …

Enabling Smart City Services For Heterogeneous Wireless Networks, Besintha Jafar Marakkarakath

Theses

A city can be transformed into a smart city if there is a resource-rich and reliable communication infrastructure available. A smart city in effect improves the quality of life of citizens by providing the means to convert the existing solutions to smart ones. Thus, there is a need for finding a suitable network structure that is capable of providing sufficient capacity and satisfactory quality-of-service in terms of latency and reliability. In this thesis, we propose a wireless network structure for smart cities. Our proposed network provides two wireless interfaces for each smart city node. One is supposed to connect to …

Wave Energy Assessment In Southern Central Java Island And Control Method For Maximizing The Captured Power In Wave Energy Converters, Fatima Sultan Ghdayer Ali Alaryani

Theses

This thesis discusses the wave energy potential of the Indian Ocean on the south coast of Central Java Island, where no previous known similar study has been conducted. A control technique that involves a dynamic electrical model was established. The following objectives were achieved. The first was to determine the ideal location to implement wave energy conversion (WEC), and the second objective was to simulate the significant wave height by using the novel control method.

To achieve these goals, the following steps and procedures were implemented. Wave energy assessment was conducted for the Indian Ocean on the south coast of …

An Immersive Learning Model, Shamsa Abdulla Salem Al Mazrouei

Theses

Our overarching goal is to provide children with immersive game-based learning environments to support Arabic linguistic skills acquisition. We postulate that immersion in- creases learning. To investigate this hypothesis, we developed a model and built an implementation of an educational virtual environment (EVE) that supports immersion and thus, induces effective learning. Experimental results confirm our hypothesis.

Our model integrates learning content, learning activities, immersion and gameplay. Based on our analysis of various curricula, specifically the United Arab Emirates grade one curriculum, we identified the nature of the learning content in order to satisfy the curriculum requirements. This content is conceptually …

Performance Study For Capillary Machine-To-Machine Networks, Maisaa Othman Albaghdadi

Theses

Communication technologies witness a wide and rapid pervasiveness of wireless machine-to-machine (M2M) communications. It is emerging to apply for data transfer among devices without human intervention. Capillary M2M networks represent a candidate for providing reliable M2M connectivity. In this thesis, we propose a wireless network architecture that aims at supporting a wide range of M2M applications (either real-time or non-real-time) with an acceptable QoS level. The architecture uses capillary gateways to reduce the number of devices communicating directly with a cellular network such as LTE. Moreover, the proposed architecture reduces the traffic load on the cellular network by providing capillary …

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 …

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 …

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 …

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 …

Electrical, Electronic And Optical Properties Of Mose2 And Wse2, Sushant Shashikant Rassay

Theses

Transition-metal dichalcogenides (TMDC) crystals have emerged as a new class of semiconductors that display distinctive properties at monolayer thickness. Their electrical, electronic and optical properties are of particular interest and importance for applications in optoelectronics as light emitters, detectors, and photovoltaic devices. Monolayer MoSe₂ and WSe₂ have an intrinsic band-gap in the visible region of the solar spectrum (400nm - 700nm) which makes them distinct from other 2-D materials like graphene.

In this study, the electrical, electronic and optical properties of monolayer and bulk MoSe₂ and WSe₂ are studied. The electronic band structures are presented for …

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 …

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 …

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 …

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 …

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 …

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 …

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 …

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. …

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 …