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Articles 1561 - 1590 of 2284

Full-Text Articles in Engineering

Investigation Of Flow And Thermal Behaviour In A Pipe Submerged In A Hot Fluid, Ben S. Steen Sep 2015

Investigation Of Flow And Thermal Behaviour In A Pipe Submerged In A Hot Fluid, Ben S. Steen

Electronic Thesis and Dissertation Repository

Convection heat transfer through a pipe immersed in a stagnant fluid is used in various applications such as water heaters, chemical and food industry, etc. In this study, the effect of mixed convection on the flow and thermal structure of a fluid immersed inside a hotter, stagnant fluid was experimentally investigated. Temperature and velocity fields were obtained for a Reynolds number range of 330-6670, and a Grashof number range of 14000-95000 (0.6 < Gr/Re2 < 0.0003). It was found that the buoyancy-induced wall-normal velocity component altered the streamwise velocity structure and the temperature profiles. The mean streamwise velocity profile was skewed towards the bottom of the pipe for initially laminar flow only. A vertical temperature gradient was also observed in the internal fluid under these conditions, where the hotter fluid resided in the top region of the pipe. The Nusselt number was found to moderately follow the predictive Gnielinski correlation, with an additional dependence on the bottom wall temperature. This showed that an increase in the Grashof number tended to dampen the turbulent convective heat transfer. The influence of natural convection on the mean and turbulent velocity profiles was found to be almost negligible in the high Reynolds number range.


Biohydrogen Production From Cellulose By Clostridium Termitidis And Clostridium Beijerinckii., Maritza Gomez-Flores Sep 2015

Biohydrogen Production From Cellulose By Clostridium Termitidis And Clostridium Beijerinckii., Maritza Gomez-Flores

Electronic Thesis and Dissertation Repository

The purpose of this study was to determine Clostridium termitidis microbial kinetics on glucose, cellobiose, and cellulose, and to assess its co-culture with Clostridium beijerinckii for hydrogen production. Microbial kinetics parameters of the mesophilic, cellulolytic, and hydrogen producer C. termitidis were determined on glucose and cellobiose using MATLAB for modelling biomass growth and substrate consumption. Hydrogen yields on these substrates were 1.99 and 1.11 mol H2 mol-1 hexose equivalent, respectively. C. termitidis microbial kinetics in mono-culture and in co-culture with mesophilic hydrogen producer C. beijerinckii were also investigated under agitated and non-agitated conditions, with hydrogen yields of 1.46 …


Fundamentals Of Electro-Flotation And Electrophoresis And Applications In Oil Sand Tailings Management, Raquibul Alam Sep 2015

Fundamentals Of Electro-Flotation And Electrophoresis And Applications In Oil Sand Tailings Management, Raquibul Alam

Electronic Thesis and Dissertation Repository

This thesis addresses two challenges facing the management of mature fine tailings (MFT) from oil sand processing. The first challenge is the high concentration of residual bitumen in tailings ponds, which poses a hazard to aquatic biota and impact to the environment. A laboratory scale study is carried out to assess the suitability of electro-flotation (EF) for removal of bitumen from oil sand tailings slurry. The results of the study confirm that EF is effective to reduce bitumen contents of tailings slurry. At a current density 150 A/m2, the bitumen concentration is reduced from 106.8 mg/L to less …


Behaviour Of Helical Pile Connectors For New Foundations, Muhammad Ahmad Muhammad Diab Sep 2015

Behaviour Of Helical Pile Connectors For New Foundations, Muhammad Ahmad Muhammad Diab

Electronic Thesis and Dissertation Repository

Despite the wide application of the connections between slender pile types, which end with a mono steel bar at the ground level (e.g. helical piles and micro piles), and new reinforced concrete foundations with limited width (e.g. RC grade beams) in the piling industry in North America, neither a clear understanding of the connections' behaviour nor a specific design criteria for their implementation is presented.

The main goal of this research was to clearly understand the behaviour of these connections and their failure mechanism under monotonic and cyclic loadings. The research methodology involved conducting experimental tests on 33 full-scale pile-foundation …


Electromechanical Coupling Behavior Of Dielectric Elastomer Transducers, Jianyou Zhou Sep 2015

Electromechanical Coupling Behavior Of Dielectric Elastomer Transducers, Jianyou Zhou

Electronic Thesis and Dissertation Repository

Dielectric elastomer transducers with large deformation, high energy output, light weight and low cost have been drawing great interest from both the research and industry communities, and shown potential for versatile applications in biomimetics, dynamics, robotics and energy harvesting. However, in addition to multiple failure modes such as electrical breakdown, electromechanical instability, loss-of-tension and fatigue, the performance of dielectric elastomer transducers are also strongly influenced by the hyperelastic and viscoelastic properties of the material. Also, the interplay among these material properties and the failure modes is rather difficult to predict. Therefore, in order to provide guidelines for the optimal design …


Secondary Electrohydrodynamic Flow Generated By Corona And Dielectric Barrier Discharges, Mohammadreza Ghazanchaei Sep 2015

Secondary Electrohydrodynamic Flow Generated By Corona And Dielectric Barrier Discharges, Mohammadreza Ghazanchaei

Electronic Thesis and Dissertation Repository

One of the main goals of applied electrostatics engineering is to discover new perspectives in a wide range of research areas. Controlling the fluid media through electrostatic forces has brought new important scientific and industrial applications. Electric field induced flows, or electrohydrodynamics (EHD), have shown promise in the field of fluid dynamics. Although numerous EHD applications have been explored and extensively studied so far, most of the works are either experimental studies, which are not capable to explain the in depth physics of the phenomena, or detailed analytical studies, which are not time effective. The focus of this study is …


Catalytic Conversion Of Glycerol To Value-Added Chemical Products, Malaya Ranjan Nanda Sep 2015

Catalytic Conversion Of Glycerol To Value-Added Chemical Products, Malaya Ranjan Nanda

Electronic Thesis and Dissertation Repository

Rapid expansion of biodiesel industry has generated a huge amount of crude glycerol. This thesis aimed to explore utilization of glycerol for the production of solketal as an oxygenated fuel additive and 1, 2-propanediol as a pre-polymer via catalytic conversion.

The thesis work may be divided into two major parts. In the first part, the thermodynamics and kinetics of the glycerol ketalization for the synthesis of solketal were investigated in a batch reactor. From this information, a continuous-flow process was designed, developed and optimized using pure glycerol. Crude glycerol (13 wt% purity) was successfully upgraded into a purified crude glycerol …


Endoscopic Targeting Tasks Simulator: An Approach Using Game Engines, Shaun W. Carnegie Sep 2015

Endoscopic Targeting Tasks Simulator: An Approach Using Game Engines, Shaun W. Carnegie

Electronic Thesis and Dissertation Repository

The pervasiveness of simulators used in professions requiring the skilled control of expensive machinery such as is the case in the aviation, mining, construction, and naval industries raises an intriguing question about the relatively poor adoption within the field of medicine. Certain surgical procedures such as neuro-endoscopic and laparoscopic lend themselves well to the application of virtual reality based simulators. This is due to the innate ability to decom- pose these complex macro level procedures into a hierarchy of subtasks that can be modelled in a software simulator to augment existing teaching and training techniques.

The research in this thesis …


Morphological Response Of Sand Bed Streams To Unsteady Flow Events: An Experimental Study, Etta Haley Gunsolus Aug 2015

Morphological Response Of Sand Bed Streams To Unsteady Flow Events: An Experimental Study, Etta Haley Gunsolus

Electronic Thesis and Dissertation Repository

Changes in riverine discharge, such as those due to reservoir flushing, seasonal variation or extreme precipitation events, can alter sediment transport rates and morphology of the stream bed. Experimental research investigated the effect of unsteady flow event hydrographs on stream bed morphological response. Laboratory experiments were conducted in a 5.0 m-long sediment transport flume with a bed comprised of a medium sand. Experimental hydrographs were composed of antecedent (base-flow), unsteady event (flood) and post- flood (return to base-flow) stages. Three distinct series of experimental laboratory runs were conducted to systematically investigate the effect of three characteristics of unsteady flow event …


Gamification Framework For Sensor Data Analytics, Alexandra L'Heureux Aug 2015

Gamification Framework For Sensor Data Analytics, Alexandra L'Heureux

Electronic Thesis and Dissertation Repository

Data in all of its form is becoming a central part of our existence, it is being captured in every facets of our everyday life: social media, pictures, smartphones, wearable devices, smart building etc. One of the main drivers of this Big Data Revolution is the Internet of Things, which enables inert objects to communicate through a multitude of sensors. The data amassed fuels a thirst for information, the extraction of such knowledge is rendered possible through Data Analytics Techniques.

However, when it comes to sensor data our large-scale ability to perform analytics is highly limited by the difficulties associated …


Calcification Of Bovine Pericardial Aortic Heart Valves, Asha Parekh Aug 2015

Calcification Of Bovine Pericardial Aortic Heart Valves, Asha Parekh

Electronic Thesis and Dissertation Repository

Heart valve disease is prevalent among Canadian population and worldwide; and for failing valves, the ultimate solution is valve replacement surgery. Bovine pericardial tissue is commonly used as a biomaterial to fabricate bioprosthetic heart valves (BHVs), however calcification of the soft tissue is an ongoing concern for its long-term performance. Calcification ultimately results in device failure due to regurgitation, stenosis, or both, which is caused by stiffening, tearing and rupturing of the tissue valve leaflets. This project investigates parameters related to bovine pericardial heart valve calcification. Three in vitro methods of calcium quantification in soft tissue were assessed using bovine …


Development Of Glass Fiber Reinforced Poly(3-Hydroxybutyrate-Co-3-Hydroxyhexanoate), Willson Arifin Aug 2015

Development Of Glass Fiber Reinforced Poly(3-Hydroxybutyrate-Co-3-Hydroxyhexanoate), Willson Arifin

Electronic Thesis and Dissertation Repository

Enhancement of mechanical properties of the bacterial polyester poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) (PHBH) by the addition of glass fibers (GF) and thermoplastic elastomers was investigated. Glass fiber addition significantly increased Young’s modulus and strength of PHBH, but had little effect on the degree of crystallinity of PHBH. To increase ductility and/or energy absorbed in fracture, that were found to be reduced, in glass fiber reinforced PHBH composites, two types of thermoplastic elastomers, styrene-ethylene-butylene-styrene copolymer (SEBS) and maleated styrene-ethylene-butylene-styrene copolymer (SEBS-MA), were added to PHBH/GF composites. SEBS-MA was more effective than SEBS in improving ductility, fracture energy, and notched Izod impact strength of PHBH/GF …


A 3-Dof Stewart Platform For Trenchless Pipeline Rehabilitation, Derek K. Brecht Aug 2015

A 3-Dof Stewart Platform For Trenchless Pipeline Rehabilitation, Derek K. Brecht

Electronic Thesis and Dissertation Repository

A major component of the infrastructure of any modern city is a network of underground pipes that transport drinking water, storm water and sewage. Most of the pipes currently being used are made out of concrete or various plastics. As with any material, they have an expected lifespan after which deterioration begins to occur. This can result in cracks, and in some cases, even large holes in the pipe which can cause a complete loss of function of the pipe. These defects invariably lead to water losses that necessitate the repair of the pipeline, which is an expensive undertaking.

The …


Investigations In Hydrodynamics And Mixing Pattern In The Bubble Column Equipped With Internals, Keller J H George Aug 2015

Investigations In Hydrodynamics And Mixing Pattern In The Bubble Column Equipped With Internals, Keller J H George

Electronic Thesis and Dissertation Repository

Bubble column reactors, with or without solid particles, have a number of applications in the chemical, petrochemical, biochemical and environmental industries. A number of these industrial applications require internals such as baffles, heat transfer surfaces and special distributors to meet demands. Proper selection and design of these internals can lead to the improved performance and efficiency of a bubble column reactor. Several experiments are carried out in a bubble column equipped with a concentric tube bundle (CT) and an internal combination consisting of a concentric tube bundle and concentric baffle (or static mixer) (CTB) respectively. Neutrally buoyant particles are used …


Elastic Highly Available Cloud Computing, Hassan Hawilo Aug 2015

Elastic Highly Available Cloud Computing, Hassan Hawilo

Electronic Thesis and Dissertation Repository

High availability and elasticity are two the cloud computing services technical features. Elasticity is a key feature of cloud computing where provisioning of resources is closely tied to the runtime demand. High availability assure that cloud applications are resilient to failures. Existing cloud solutions focus on providing both features at the level of the virtual resource through virtual machines by managing their restart, addition, and removal as needed. These existing solutions map applications to a specific design, which is not suitable for many applications especially virtualized telecommunication applications that are required to meet carrier grade standards. Carrier grade applications typically …


Tropical Cyclone Wind Hazard Assessment For Southeast Part Of Coastal Region Of China, Sihan Li Aug 2015

Tropical Cyclone Wind Hazard Assessment For Southeast Part Of Coastal Region Of China, Sihan Li

Electronic Thesis and Dissertation Repository

Tropical cyclone (TC) or typhoon wind hazard and risk are significant for China. The return period value of the maximum typhoon wind speed is used to characterize the typhoon wind hazard and assign wind load in building design code. Since the historical surface observations of typhoon wind speed are often scarce and of short period, the typhoon wind hazard assessment is often carried out using the wind field model and TC track model. For a few major cities in the coastal region of mainland China, simple or approximated wind field models and a circular subregion method (CSM) have been used …


Design And Control Of Robotic Systems For Lower Limb Stroke Rehabilitation, Aaron Yurkewich Aug 2015

Design And Control Of Robotic Systems For Lower Limb Stroke Rehabilitation, Aaron Yurkewich

Electronic Thesis and Dissertation Repository

Lower extremity stroke rehabilitation exhausts considerable health care resources, is labor intensive, and provides mostly qualitative metrics of patient recovery. To overcome these issues, robots can assist patients in physically manipulating their affected limb and measure the output motion. The robots that have been currently designed, however, provide assistance over a limited set of training motions, are not portable for in-home and in-clinic use, have high cost and may not provide sufficient safety or performance. This thesis proposes the idea of incorporating a mobile drive base into lower extremity rehabilitation robots to create a portable, inherently safe system that provides …


Real Time Testing And Validation Of A Novel Short Circuit Current (Scc) Controller For A Photovoltaic Inverter, Vishwajitsinh H. Atodaria Aug 2015

Real Time Testing And Validation Of A Novel Short Circuit Current (Scc) Controller For A Photovoltaic Inverter, Vishwajitsinh H. Atodaria

Electronic Thesis and Dissertation Repository

About 45% applications from PV solar farm developers seeking connections to the distribution grids in Ontario were denied in 2011-13 as the short circuit current (SCC) capacity of several distribution substations had already been reached. PV solar system inverters typically contribute 1.2 p.u. to 1.8 p.u. fault current which was not considered acceptable by utility companies due to the need for very expensive protective breaker upgrades. Since then, this cause has become a major impediment in the growth of PV based renewable systems in Ontario.

A novel predictive technique has been patented in our research group for management of short …


Experimental Analysis Of Parameters Influencing The Bone Burring Process, Jonathan Kusins Aug 2015

Experimental Analysis Of Parameters Influencing The Bone Burring Process, Jonathan Kusins

Electronic Thesis and Dissertation Repository

The experimental quantification of the bone removal characteristics associated with bone burring represents a desirable outcome mainly for the selection of optimal parameters. An experimental apparatus was developed that allowed for concurrent measurement of three outputs associated with the bone removal process (cutting force, vibration, and temperature) as a function of various burring-specific parameters. Initial process trends were established on a uniform sawbone analog through use of a fully balanced multivariate statistical analysis. A smaller set of optimal and suboptimal parameters were further validated using a porcine femur. From the parameters tested, an optimal tool configuration, to avoid high temperature …


Blood Supply To The Brain Via The Carotid Arteries: Examining Obstructive And Sclerotic Disorders Using Theoretical And Experimental Models, Onaizah Onaizah Aug 2015

Blood Supply To The Brain Via The Carotid Arteries: Examining Obstructive And Sclerotic Disorders Using Theoretical And Experimental Models, Onaizah Onaizah

Electronic Thesis and Dissertation Repository

Stroke remains one of the leading causes of death in North America. Approximately half of all ischemic episodes are a direct result of carotid artery disease, which can be categorized into either obstructive or sclerotic disease. Obstructive disease is a result of plaque development that imposes a direct limitation on the physical space available for blood flow. Sclerotic disease involves the hardening of the arteries as is often a result of aging and disease. While the impact of vessel stiffening is not as obvious, it does interfere with wave propagation. Effects of obstructive and sclerotic disease were studied using a …


Modern Optimization Algorithms And Applications: Architectural Layout Generation And Parallel Linear Programming, Bradley J. De Vlugt Aug 2015

Modern Optimization Algorithms And Applications: Architectural Layout Generation And Parallel Linear Programming, Bradley J. De Vlugt

Electronic Thesis and Dissertation Repository

This thesis examines two topics from the field of computational optimization; architectural layout generation and parallel linear programming. The first topic, a modern problem in heuristic optimization, focuses on deriving a general form of the optimization problem and solving it with the proposed Evolutionary Treemap algorithm. Tests of the algorithm's implementation within a highly scalable web application developed with Scala and the web service framework Play reveal the algorithm is effective at generated layouts in multiple styles. The second topic, a classical problem in operations research, focuses on methodologies for implementing the Simplex Algorithm on a parallel computer for solving …


The Application Of The Ultrafine Technology In Improving The Biocompatibility And Osteo-Inductivity Of Dental Implants, Nicholas Y. Hou Aug 2015

The Application Of The Ultrafine Technology In Improving The Biocompatibility And Osteo-Inductivity Of Dental Implants, Nicholas Y. Hou

Electronic Thesis and Dissertation Repository

Dental implants are very effective medical devices. However, although stable, the conventional titanium implants are not very bioactive which in some instances could reduce their efficacy. This thesis described the research progress of using polymeric ultrafine-particles with bioactive additives to enrich the surface of titanium substrate, thereby increasing the biocompatibility and osteo-inductivity of the biomaterial. During this doctoral project, three different types of polymers were examined, initially the conventional polyester, and later the novel epoxy as well as the epoxy/polyester hybrid polymers. Physical characterizations confirmed that all of the coating powders were ultrafine particles, and homogeneous surfaces were constructed from …


Self-Sustaining Smouldering Combustion As A Novel Disposal Destruction Method For Waste Water Biosolids, Tarek L. Rashwan Aug 2015

Self-Sustaining Smouldering Combustion As A Novel Disposal Destruction Method For Waste Water Biosolids, Tarek L. Rashwan

Electronic Thesis and Dissertation Repository

Managing biosolids, the major by-product from wastewater treatment plants (WWTPs), persists as a major global challenge that often constitutes the majority of WWTP operating costs. Self-sustained smouldering is a new approach for organic waste treatment, in which the waste (i.e., the fuel) is destroyed in an energy efficient manner after mixing it with sand. Smouldering has never been applied to biosolids. Column experiments, using biosolids obtained from a WWTP, were employed to identify if - and under what conditions - smouldering could be used for treating biosolids. The parameter space in which smouldering was self-sustaining was mapped as a function …


Location Estimation In Wireless Communication Systems, Kejun Tong Aug 2015

Location Estimation In Wireless Communication Systems, Kejun Tong

Electronic Thesis and Dissertation Repository

Localization has become a key enabling technology in many emerging wireless applications and services. One of the most challenging problems in wireless localization technologies is that the performance is easily affected by the signal propagation environment. When the direct path between transmitter and receiver is obstructed, the signal measurement error for the localization process will increase significantly. Considering this problem, we first propose a novel algorithm which can automatically detect and remove the obstruction and improve the localization performance in complex environment. Besides the environmental dependency, the accuracy of target location estimation is highly sensitive to the positions of reference …


Smart Pv Inverter Control For Distribution Systems, Ehsan M. Siavashi Aug 2015

Smart Pv Inverter Control For Distribution Systems, Ehsan M. Siavashi

Electronic Thesis and Dissertation Repository

PV solar systems employ inverters to transform dc power from solar panels into ac power for injecting into the power grids. Inverters that perform multiple functions in addition to real power production are known as “smart inverters”.

This thesis presents a novel control of PV inverter as a dynamic reactive power compensator – STATCOM. This “smart PV inverter” control enables a PV solar inverter to operate in three modes – i) Full PV, ii) Partial STATCOM, and iii) Full STATCOM, depending upon system needs. The novel control is developed and demonstrated for the objectives of a) symmetrical voltage regulation, b) …


Development Of A Wearable Mechatronic Elbow Brace For Postoperative Motion Rehabilitation, Anastasiia Kyrylova Aug 2015

Development Of A Wearable Mechatronic Elbow Brace For Postoperative Motion Rehabilitation, Anastasiia Kyrylova

Electronic Thesis and Dissertation Repository

This thesis describes the development of a wearable mechatronic brace for upper limb rehabilitation that can be used at any stage of motion training after surgical reconstruction of brachial plexus nerves. The results of the mechanical design and the work completed towards finding the best torque transmission system are presented herein. As part of this mechatronic system, a customized control system was designed, tested and modified. The control strategy was improved by replacing a PID controller with a cascade controller. Although the experiments have shown that the proposed device can be successfully used for muscle training, further assessment of the …


Stochastic Stability And Uncertainty Quantification Of Ring-Based Vibratory Gyroscopes, Soroush Arghavan Aug 2015

Stochastic Stability And Uncertainty Quantification Of Ring-Based Vibratory Gyroscopes, Soroush Arghavan

Electronic Thesis and Dissertation Repository

Effect of stochastic fluctuations in angular velocity on the stability of two DOF ring-type MEMS gyroscopes is investigated. The governing Stochastic Differential Equations are discretized using the higher-order Milstein scheme in order to numerically predict the system response assuming the fluctuations to be white noise. Simulations via Euler scheme as well as a measure of Largest Lyapunov Exponents are employed for validation purposes due to lack of similar analytical or experimental data. The stability investigation predicts that the threshold fluctuation intensity increases nonlinearly with damping ratio. Under typical gyroscope operating conditions, nominal input angular velocity magnitude and mass mismatch appear …


Mercury Removal From Aqueous Solution Using Natural, Synthetic, And Modified Zeolites, Mahshid Attari Aug 2015

Mercury Removal From Aqueous Solution Using Natural, Synthetic, And Modified Zeolites, Mahshid Attari

Electronic Thesis and Dissertation Repository

Mercury has been recognized as one of the most hazardous heavy metals. The discharge of effluents containing mercury in soil, sediments and water can inflict an irreversible harm to the environment and human health. In this work, zeolitized coal fly ash as well as gold and gold-iron modified zeolites were successfully employed for mercury removal from a typical industrial wastewater. X-ray diffraction (XRD), thermo-gravimetrical analyses (TGA), surface area measurement (BET), and scanning electron microscopy (SEM-EDX) were utilized to explore the characteristics of the raw and modified zeolites. A pseudo-second-order kinetic model was identified to best represent the kinetic data for …


Exploitation Of Data Correlation And Performance Enhancement In Wireless Sensor Networks, Tianqi Yu Aug 2015

Exploitation Of Data Correlation And Performance Enhancement In Wireless Sensor Networks, Tianqi Yu

Electronic Thesis and Dissertation Repository

With the combination of wireless communications and embedded system, lots of progress has been made in the area of wireless sensor networks (WSNs). The networks have already been widely deployed, due to their self-organization capacity and low-cost advantage. However, there are still some technical challenges needed to be addressed. In the thesis, three algorithms are proposed in improving network energy efficiency, detecting data fault and reducing data redundancy.

The basic principle behind the proposed algorithms is correlation in the data collected by WSNs. The first sensor scheduling algorithm is based on the spatial correlation between neighbor sensor readings. Given the …


Novel Carbon-Supported Transition Metal Phosphide Catalysts For Hydrodeoxygenation Of Fast Pyrolysis Oil, Cheng Guo Aug 2015

Novel Carbon-Supported Transition Metal Phosphide Catalysts For Hydrodeoxygenation Of Fast Pyrolysis Oil, Cheng Guo

Electronic Thesis and Dissertation Repository

Catalytic hydrodeoxygenation (HDO) is considered to be the most promising route to upgrade pyrolysis oil to liquid transportation fuels. The objective of this research was to explore inexpensive supported metal oxides/metal phosphide catalysts for the upgrading of pyrolysis oil into advanced drop-in hydrocarbon liquid fuels by HDO.

The first stage of this thesis project investigates a series of molybdenum oxides/phosphide catalysts on different supports that were prepared in-house, such as Al2O3, activated carbon (AC), MgAl2O4 and Mg6Al2(CO3)(OH)16. The HDO activity of these catalysts were investigated …