Digital Commons Network^™

A Hardware Security Solution Against Scan-Based Attacks, Ankit Mehta

Electronic Theses and Dissertations

Scan based Design for Test (DfT) schemes have been widely used to achieve high fault coverage for integrated circuits. The scan technique provides full access to the internal nodes of the device-under-test to control them or observe their response to input test vectors. While such comprehensive access is highly desirable for testing, it is not acceptable for secure chips as it is subject to exploitation by various attacks. In this work, new methods are presented to protect the security of critical information against scan-based attacks. In the proposed methods, access to the circuit containing secret information via the scan chain …

Investigation Of Plasma Electrolytic Oxidation (Peo) Coated Bores In Internal Combustion Engines, Vladislav Leshchinsky

Electronic Theses and Dissertations

With increasing fuel economy and emission restrictions being placed onto the automotive industry, there is always a need for innovation and research in striving to reduce energy loss and make internal combustion engines more efficient. An area of potential improvement is through the reduction of frictional parasitic losses in tribological systems. This study investigates the feasibility of use for low-friction Plasma Electrolytic Oxidation (PEO) coatings on cylinder bores in order to reduce the frictional coefficients along the piston ring and cylinder bore sliding surface. For PEO coatings, wear is a limiting factor and this study aims at understanding the main …

Fatigue Crack Growth Of Nps20 Steel Oil Pipe At Varied Orientations, Craig G. L. Taylor

Electronic Theses and Dissertations

Very few studies concerning fatigue of oil pipe have been conducted using full-scale tests. Further, no research is found in open literature concerning fatigue cracks in the longitudinal direction of pipes, despite being deemed more critical. Fatigue crack growth was investigated in NPS 20, API 5L X-70 grade, straight-seam steel oil pipes in the base metal and at the welded joint for various orientations. Specifically, the effect of the welded joint and crack orientation on the fatigue crack growth behaviour relative to a longitudinal crack in the base metal was determined. The fatigue crack growth behaviour of a longitudinal crack …

New Materials And Methods For The Fabrication Of Large-Area Stretchable Electronics, Heather Lynn Filiatrault,

Electronic Theses and Dissertations

This dissertation addresses three main challenges towards the fabrication of large-area stretchable electronic devices. First, we replaced expensive photolithography techniques with low-cost methods to achieve highly stretchable gold films on elastomers. Second, we enabled the fabrication of large-area stretchable pixels through the incorporation of stretchable elastomers in the emissive layer of light-emitting devices. Third, we made progress towards theinception of air-stable large-area stretchable electronics by developing methods to deposit conductive metal films on new highly impermeable stretchablesubstrates.

Chapter 2 describes the deposition of a low-cost, microstructured glue interlayer on an elastomeric substrate to enable the fabrication of gold films with …

In-Field Observations Of Heavy Mining Vehicle Wheels And Analyses Of Proposed Solutions To Enhance Safety, Aleksander Tonkovich

Electronic Theses and Dissertations

This research strives to enhance the safety of multi-piece wheel assemblies as injuries and fatalities are associated with their failure, yet information on this topic is limited. Experiments were performed to determine mechanical performance and planar deformation characteristics of several tires to aid in numerical model development. For a 29.5-29 tire, observations included determining vertical versus lateral deflection relationships (0.310 mm/mm), and vertical (2.59 kN/mm) and lateral (6.29 kN/mm) stiffness. A database capable of tracking wheel maintenance trends based on historical data was developed, allowing maintenance schedules to be estimated. A safety shield system was proposed. Effectiveness of the design …

Thermal And Microstructural Analysis Of The A356 Alloy Subjected To High Pressure In The Squeeze Casting (Sc) Umsa Technology Platform, Mohammad Khurshed-Ul Alam

Electronic Theses and Dissertations

The effect of cyclic pressure on the thermal and microstructural behaviour of the A356 alloy and the addition of commercial Al-Sr Master Alloy, Nano Alumina Master Alloy and a combination of both Master Alloys during the squeeze casting was investigated in this study. The results show that the α-dendrite growth temperature was increased and the Al-Si eutectic growth temperature was decreased substantially, resulting in a super refined, as-cast, equiaxed α-Al cells and ultra fine dendritic eutectic Si in the modified and unmodified A356 aluminum alloy. Moreover, very rapid spheroidization of the Si particles was observed within a very short Solution …

Development Of A Generalized Finite Difference Scheme For Convection-Diffusion Equation, Shixin He

Electronic Theses and Dissertations

The traditional finite difference method has an important limitation in practical applications, which is the requirement of a structured grid. The purpose of this thesis is to improve the finite difference scheme for application on complex domains. The analysis of the Finite Difference method is carried out for 1D model problems governed by the convection-diffusion equation. The Stencil Mapping method is developed for complex domains. One of the features of this new scheme is that the value at a node can be calculated by using only the neighbouring values on the 3-point stencil. This allows finite differencing for arbitrary nodal …

Failure Mechanism Of Coated Biomaterials Under High Impact-Sliding Contact Stresses, Ying Chen

Electronic Theses and Dissertations

This study uses a newly developed testing method-- inclined cyclic impact-sliding test to investigate the failure behaviors of different types of biomaterials, (SS316L, Ti6Al4V and CoCr) coated by different coatings (TiN, DLC and PEO), under extremely high dynamic contact stress conditions. This test method can simulate the combined impact and sliding/rolling loading conditions, which is very practical in many aspects of commercial usages. During the tests, fatigue cracking, chipping, peeling and material transferring were observed in damaged area. This research is mainly focused on the failure behaviors of load-bearing materials which cyclic impacting and sliding are always involved. This purpose …

Study Of Fuels And Fuelling Strategies For Enabling Clean Combustion In Compression Ignition Engines, Xiaoye Han

Electronic Theses and Dissertations

The main objective of this dissertation is to improve the efficiency and emissions of compression ignition engines. Adaptive fuelling control strategies are applied for enabling the low temperature combustion on the research engines of high compression ratios using a selected set of fuels that are vastly different from the conventional diesel. These fuels include n-butanol, gasoline, ethanol, and nine diesel fuels with specifically formulated Cetane numbers, aromatic contents, and boiling temperatures. The effects of these fuels on the engine performance are compared with those of diesel in both the high temperature combustion and low temperature combustion modes in terms of …

Determination Of Optimal Power For Zigbee-Based Wireless Sensor Networks, Okhamila Yusuf

Electronic Theses and Dissertations

In designing WSNs, both the transmit power, network topology, and routing scheme are considered. Transmitting at lower power affect the connectivity of the network while transmitting at excessive power reduces the lifetime of nodes and increases the network interference. Thus, determining the optimal power of the nodes that will be necessary to guarantee network connectivity. In this work, a practical self-healing and self-configuring real life prototype ZigBee Wireless Mesh Sensor Networks (WMSNs) was design to evaluate the performance of IEEE 802.15.4/ZigBee. We showed that increasing the transmit power of nodes from -6dBm to 0dBm in WMSNs leads to improved packets …

Web Service Network Analysis, Avani Gade

Electronic Theses and Dissertations

A Web Service is a software component that is accessible on the Web. Web Services can collaborate to form composite services, which are called Mashups. Services and Mashups interconnect with each other, forming a complex network. This technological network evolves in a large scale without central control. As a new type of software network, there is an urgent need to study its topological properties. This thesis studies the Web Service Network that consists of 4255 primitive web services and mashups collected from ProgrammableWeb.com. We study various centralities of the network, including degree, betweenness, closeness and page rank. We find that …

Experimental Determination Of The Forming Limits Of Dp600 And Aa5182 Sheets In Electrohydraulic Free Forming, Christopher Joel Lyall Maris

Electronic Theses and Dissertations

Electrohydraulic forming is a pulsed metal forming process that uses the discharge of electrical energy across a pair of electrodes submerged in fluid to form sheet metal. Pulsed metal forming processes, including electrohydraulic forming, have been shown to increase the formability of sheet metals, which is of significant industrial interest. An experimental procedure was developed to quantify the formability in electrohydraulic free forming (EHFF) that is consistent with the quasi-static formability assessment convention. Novel sheet metal specimen geometries were created to quantify the formability across the entire minor strain spectrum. The experimental EHFF forming limit curve (FLC) was determined for …

Effect Of Suction On Local Scour Around Circular Bridge Piers, Mohammed Jahan

Electronic Theses and Dissertations

An experimental study was conducted in the Hydraulics Laboratory of the University of Windsor, involving analysis of local scour around circular model bridge piers placed on a non-cohesive sand bed, with suction and no suction conditions. Experiments were conducted using three model circular piers. The results show that a narrower pier will induce a large value of depth averaged channel mean velocity in comparison to a wider pier in the same flow field. Furthermore, suction generally creates larger equilibrium scour depth, and increases near bed velocity, and decreases friction velocities with increasing suction. The present results indicate that, generally, scour …

Effects Of Inflow Parameters And Operating Conditions On The Structural Response And Power Production Of A Commercial Wind Turbine, Jamie C. Smith

Electronic Theses and Dissertations

Onshore wind farms can experience a wide variety of wind conditions, even in simple or flat terrain, as a result of diurnal and seasonal changes in stability in the atmospheric boundary layer. At a farm in Southwestern Ontario, a commercial-sized wind turbine operates in close proximity to a meteorological mast capable of quantifying the inflow parameters of the approaching wind profile. The turbine's steel supporting tower has been instrumented with an optical strain gauge array measuring longitudinal deformation at multiple elevations. Wind conditions have been classified into two major profile types on the basis of two key inflow parameters: vertical …

Transient And Steady-State Mobile Air Conditioning Operation With The Inclusion Of And Internal Heat Exchanger, Stephen Gemin

Electronic Theses and Dissertations

This thesis investigates the change in power consumption for a mobile air conditioning (MAC) system from the introduction of an internal heat exchanger (IHX). The internal heat exchanger is so named since it is a simple heat exchanger that is placed internally into the AC system. It serves to transfer heat from the high to low pressure refrigerant to maximize the system cooling capacity. The work investigates how other performance parameters such as the pressure drops, IHX capacity, evaporator capacity, coefficient of performance and the absolute efficiency ratio change from the introduction of the IHX. The steady-state simulation results are …

Investigation Of Metallurgical Coatings For Automotive Applications, Jun Feng Su

Electronic Theses and Dissertations

Metallurgical coatings have been widely used in the automotive industry from component machining, engine daily running to body decoration due to their high hardness, wear resistance, corrosion resistance and low friction coefficient. With high demands in energy saving, weight reduction and limiting environmental impact, the use of new materials such as light Aluminum/magnesium alloys with high strength-weight ratio for engine block and advanced high-strength steel (AHSS) with better performance in crash energy management for die stamping, are increasing. However, challenges are emerging when these new materials are applied such as the wear of the relative soft light alloys and machining …

Turbulence Convective Heat Transfer For Cooling The Photovoltaic Cells, Iman Arianmehr

Electronic Theses and Dissertations

Solar PV (photovoltaic) is a rapidly advancing renewable energy technology which converts sunlight directly into electricity. One of the outstanding challenges of the current PV technology is the reduction in its conversion efficiency with increasing PV panel temperature, which is closely associated with the increase in solar intensity and the ambient temperature surrounding the PV panels. To more effectively capture the available energy when the sun is most intense, significant efforts have been invested in active and passive cooling research over the last few years. While integrated cooling systems can lead to the highest total efficiencies, they are usually neither …

Modeling Truck Toll Competition Between Two Cross-Border Bridges Under Various Regimes, Qi Li

Electronic Theses and Dissertations

The competition between a new publicly-owned cross-border bridge and the existing Ambassador Bridge is modeled in this thesis as a duopoly game where each bridge's strategy is its toll level. We assume the Ambassador Bridge always wants to maximize its profit, while the new bridge may have various objective functions. The competition between the two bridges has a natural bi-level structure, with the upper level being the two bridges setting their respective tolls, and the lower level being the road users choosing their routes. The competition equilibrium (i.e. Nash equilibrium) emerges when each bridge cannot improve its objective function by …

Affordance Based Human Behaviour Model For Group Path Finding, Lokesh Patil

Electronic Theses and Dissertations

Many advanced models are developed to predict human behaviour that explains human actions in some specific environment. This study refers to some of those models, such as work behaviour model which deals with the theory of purposeful work behaviour by agents in a work environment. Some behaviour models includes cognitive, emotional and social aspects of human behaviour such as PECS model. Some models deals with affordance theory which focuses on the relation between agent, his actions and his observations. All these models offer suitability towards the formation of a new computational model which identifies human behavioural aspects individually. Our new …

Decision System For Incremental Upgrades Of The Power Distribution System For Electric Vehicles, Syed Mohammad Sami

Electronic Theses and Dissertations

The growing demand of Electric energy powered vehicles has some unwanted side effects on the current power grid system. Some of these side effects are wires not being able to sustain such high currents for prolonged periods of time, transformers not being able to sustain stable voltages [1], to sustain the added energy demands. Thus, we have to solve how and where we can provide a feasible incremental upgrade approach for the energy distribution companies. This requires us to monitor voltage and current output of various nodes in the electrical distribution system, which is able to collect data and identify …

Grouping And Sequencing Of Machining Operations For High Volume Transfer Lines, Soumitra Subhash Bhale

Electronic Theses and Dissertations

Transfer lines are employed for mass production of a fixed product or a very narrow range of product variants. This thesis considers a simple transfer line balancing problem with a focus on process planning and line configuration. Design features of the product are grouped and machining operations are sequenced in an optimal manner. The objective is to minimize the handling time fraction of the cycle time consisting mainly of orientation change time and tool change time. A new MILP model is developed to solve the problem with the aforementioned objectives while respecting a set of constraints, which include cutting tool …

Effect Of Grain Refiners On Squeeze Casting Of Magnesium Alloy Am60, Yanda Zou

Electronic Theses and Dissertations

The effect of hexachloroethane (C 2 Cl 6 ) and calcium carbide (CaC 2 ) as grain refiners added into the squeeze casting AM60 magnesium alloys was investigated in this study. The results of thermal analysis and microstructural analysis indicate the occurrence of heterogeneous nucleation of primary magnesium during solidification. The microstructural analysis suggests that the nucleation behaviors of C 2 Cl 6 /CaC 2 -treated AM60 alloys may be attributed to the increase in nuclei and nucleation rate during the solidification of the magnesium alloy. Grain size measurements indicated that both C 2 Cl 6 and CaC 2 have …

Modelling Of Flow And Heat Transport In Vertical Loop Ground Heat Exchangers, Christopher G. Cvetkovski

Electronic Theses and Dissertations

The performance of ground source heat pumps relies greatly on the heat transfer efficiency throughout the ground loop configuration. Vertical ground loops can employ a U-Bend or a Coaxial pipe configuration which generates vortical structures and turbulence, enhancing the heat transfer process. For the U-Bend, the Dean Number (radius of curvature) and the Reynolds Number (inlet velocity) are tested. For the Coaxial, the inner pipe offset, and the Reynolds Number (inlet velocity) are tested for improved configurations. For the U-Bend, it was found the Reynolds Number dominates. In the Coaxial system, it was found that inner pipe offset destroys the …

Mechanical And Material Characterization Of Mining Wheels For Enhanced Safety, Sante Dicecco

Electronic Theses and Dissertations

A study was undertaken to evaluate the mechanical and material behaviour of the Q345 alloy, used in fabrication of five-piece mining wheel assemblies. Material samples were extracted from all components of a five-piece wheel. Material testing included compositional analyses, fully submerged corrosion testing, and microstructural analyses. Mechanical testing included hardness testing, tensile testing and stress-based high-cycle fatigue testing of specimens with polished and pre-corroded surface conditions. Special emphasis was placed on obtaining the fatigue behaviour of the alloy in the pre-corroded condition. Component microstructures were all found to consist of ferrite and colony pearlite. Ultimate tensile strengths of most component …

An Interactive Approach To Software Visualization For Customization, Manpreet Singh Kaler

Electronic Theses and Dissertations

The Software Product Line (SPL) provides software customization by composing several different web services together. When further supported by Service-Oriented Architecture (SOA), SPL offers unprecedented advantages for reusing software artifacts in mass customization of software applications, leading to radically reduced time, cost, and effort of software development. A Petri-Net based visualization system for the software customization has been developed in our research group. This thesis works on enhancement of the prior work by introducing an interactive approach of software visualization for software customization. The proposed approach segregates the users based on their interaction with the system and the best suited …

Waste Heat Recovery Systems For Fuel Economy, Gianmarco Capano

Electronic Theses and Dissertations

The largest automakers strive to reduce carbon dioxide emissions to meet regulations by improving engine efficiency. A device that recovers a portion of the heat wasted in the exhaust gas could be a highly effective solution. It is believed that the most appealing technology is the Organic Rankine Cycle for its ability to recover heat from low temperature sources and its limited costs. However, Waste Heat Recovery (WHR) is still far from being employed in mass production light duty vehicles because there are still several unsolved problems. To assess the feasibility of such devices it is fundamental to develop a …

Development Of Hybrid Composite Co-Pultruded Structural Members, Hart Noah Honickman

Electronic Theses and Dissertations

Fibre reinforced polymer (FRP) materials offer many advantages over conventional metallic structural materials due to their high specific strength and stiffness, long fatigue life, and resistance to environmental corrosion. However, these materials present some unique engineering challenges due to their anisotropy and heterogeneity. The connection of these composite parts to adjacent components often results in complex and counter-intuitive states of stress that can be quite difficult to model. Furthermore, since these materials are, in a sense, synthesized during the fabrication of the final part, the mechanical properties that can be expected from FRP structures are largely dependent upon highly skilled …

Aluminum Foam Core Density And Geometry Influences On The Deformation Mechanisms And Energy Absorption Capacity Of Foam Filled Braided Tubular Structures In Axial And Transverse Loading, Ramsin Audysho

Electronic Theses and Dissertations

The mechanical response of an energy absorbing device was studied experimentally by means of a custom built testing machine. Results showed that the force/displacement behavior was strongly dependent upon foam density; however after tow lockup this dependency was reduced. Axially loaded specimens utilizing circular cores reduced the total elongation to failure and maximum load by approximately 120 mm and 7 kN, respectively compared to specimens utilizing rectangular cores. Good agreement and deviation between theoretical results and experimental tests for specimens with low and high density cores were observed with an error of 3.03% and 16.45%, respectively. Significant tensile loads and …

Performance Of Basalt Fibre Mixed Concrete, Padmanabhan Iyer

Electronic Theses and Dissertations

In this research, the mechanical properties of smart concrete made of chopped basalt fibre were investigated. Two different types of basalt fibres (bundles and filaments) were used.The basalt fibre specimens were cast using basalt fibres of varying length (12 mm, 36 mm, and 50 mm) and varying fibre dosage (4 kg/m 3 , 8 kg/m 3 , and 12 kg/m 3 ). The results indicated that the 50 mm basalt bundled fibre at 8 kg/m 3 was the optimum fibre length and fibre volume for basalt bundled fibres. It provided the optimum increase in flexural strength, compressive strength, and split …

Analysis Of Heat Transfer In Spray Cooling Systems Using Numerical Simulations, Masoumeh Jafari

Electronic Theses and Dissertations

The impingement of sprays onto dry and wet walls and the associated heat transfer occurs in many engineering applications. These applications include internal combustion engines, gas turbines, spray drying, spray coating and spray cooling. The fluid dynamics and heat transfer characteristics of liquid films created by spray impingement are very complex and determining the underlying physics requires fundamental studies. In this study, an efficient and practical approach is devised for tackling many aspects of the spray cooling process. The computational fluid dynamics (CFD) methodology used here includes numerous droplets and it is designed to predict the spray-wall impact outcome based …