Engineering Commons^™

Adaption Of Catechol And Reversible Addition-Fragmentation Chain-Transfer (Raft) Chemistries For Water-Based Applications, Olabode Oyeneye

Electronic Thesis and Dissertation Repository

Incorporating the binding chemistry of catechol functionality with RAFT chemistry offers a facile and simplified approach for developing a suite of new 2D and 3D hybrid materials with tailored morphologies. Leveraging both chemistries by synthesizing catechol-end functionalized RAFT agents and catechol-containing monomeric species for RAFT (co)polymerization, this dissertation examined a new series of advanced materials that were designed for water-based applications including model flocculants, thermoresponsive hydrogels, adsorbents and underwater adhesives.

To prepare the RAFT agents, novel trithiocarbonates with several catechol end R groups (as postpolymerization anchors) were synthesized that differ in their carbonyl α-substituents (Dopa-CTAs). These materials were evaluated for …

A Performance Based Design Approach For Tall Buildings Under Wind Loading, Fouad Y. Elezaby

Electronic Thesis and Dissertation Repository

The wind design of buildings is typically based on strength provisions under ultimate loads. This is unlike the ductility-based approach used in seismic design, which allows inelastic actions to take place in the structure under extreme seismic events. This research investigates the application of a similar concept in wind engineering. In seismic design, the elastic forces resulting from an extreme event of high return period are reduced by a load reduction factor. A load reduction factor is chosen by the designer and accordingly a certain ductility capacity needs to be achieved in the structure. Two reasons have triggered the investigation …

Assessment Of Dynamic Effect Of Transmission Line Conductor Longitudinal Reaction Due To Downburst Loading, Ibrahim Ibrahim

Electronic Thesis and Dissertation Repository

Due to the locality and non-stationary nature of downburst wind loading events, their effect on the structural response of transmission line structures is of special nature that differs from conventional atmospheric boundary layer wind loading. Acknowledging such difference, the current thesis aims to quantify the dynamic effect associated with downburst loading on transmission line systems. To achieve that, several steps had to be realized, including experimentally verifying the numerical model used for analysis using wind field that was generated using computational fluid dynamics. The verified model was extended from model scale to full scale, where the wind field used for …

Fabrication And Modification Of Titania Nanotube Arrays For Harvesting Solar Energy And Drug Delivery Applications, Ahmed El Ruby Abdel Rahman Mohamed

Electronic Thesis and Dissertation Repository

The fast diminishing of fossil fuels in the near future, as well as the global warming caused by increasing greenhouse gases have motivated the urgent quest to develop advanced materials as cost-effective photoanodes for solar light harvesting and many other photocatalytic applications. Recently, titania nanotube arrays (TNTAs) fabricated by anodization process has attracted great interest due to their excellent properties such as: high surface area, vertically oriented, highly organized, one-dimensional, nanotubular structure, photoactivity, chemical stability and biocompatibility. This unique combination of excellent properties makes TNTAs an excellent photoanode for solar light harvesting. However, the relatively wide band gap energy of …

Modelling Of Future Flood Risk Across Canada Under Climate Change, Ayushi Gaur

Electronic Thesis and Dissertation Repository

Climate change has induced changes in key climate variables and hydrological cycle in Canada. In this study, future runoff projections made by 21 GCMs following four Representative Concentration Pathways (RCPs) are used as inputs into a macro-scaled hydrodynamic model: CaMa-Flood to simulate 25 km resolution daily streamflow across Canada for historical (1961-2005) and future (2061-2100) time-periods. Future changes in flood-hazard as a consequence of changes in flooding frequencies of historical 100-year and 250-year return period flood events, and changes in the month of occurrence of extreme flows are analyzed. Changes in flood risk at Canada’s 100 most populous cities and …

Thermo-Hydro-Mechanical Analysis Of Evaporation From Unsaturated Soils, Seyed Morteza Mousavi

Electronic Thesis and Dissertation Repository

ABSTRACT

Estimating evaporation from unsaturated soil is important for many applications including agriculture, climate, hydrology, water resources, saturated and unsaturated groundwater flow, slope stability, and soil covers. As an example, the long term performance of soil covers, which are widely used in mining and landfill applications to protect the environment, strongly depends on evaporation from their surfaces.

Evaporation depends on both moisture flow within an unsaturated soil mass, which is generally coupled with heat flow, and void ratio and hydraulic and air conductivities, which are in turn affected by stress and strain and resulting soil settlement. This makes thermo-hydro-mechanical (THM) …

Investigation Of Ductile Crack Growth And Normalization Method For Se(T) Specimen Using Finite Element Analyses, Cheng Qian

Electronic Thesis and Dissertation Repository

The fracture toughness resistance curve (e.g. J-R curve) is widely used in integrity assessment and strain-based design of oil and gas pipelines with respect to planar defects (i.e. cracks). This thesis includes two-dimensional (2D) and three-dimensional (3D) finite element analyses (FEA) of ductile crack growth of X80-grade pipeline steel based on the Gurson-Tvergaard-Needleman (GTN) constitutive model, and investigation of the normalization (NM) method to generate the J-R curve for the single-edge tension (SE(T)) specimen.

First, the GTN model implemented in the computational cell is adopted in the commercial software ABAQUS to calibrate the micromechanical parameters for the pipeline steel. Subsequently, …

Partial Material Strength Reduction Factors For Aci 318, Tong Zhang

Electronic Thesis and Dissertation Repository

The strength reduction factors, phi, defined in ACI 318-14 for different structural actions and elements lead to inconsistent results. This study proposes partial material strength reduction factors for concrete, phi_c, and reinforcing steel, phi_s, that yield similar design strengths and more consistent reliability indices. Three structural actions are investigated: moment; shear; and, combined moment and axial force. The first-order, second-moment method is used to compute reliability indices for moment and shear, and Monte Carlo simulation is used for combined moment and axial force. The statistical parameters assumed for the professional factor for shear strength significantly impact …

Behaviour Of Pre-Stressed Concrete Transmission Poles Under High Intensity Wind, Ahmed M. Ibrahim

Electronic Thesis and Dissertation Repository

Among different types of electrical transmission line structures, pre-stressed concrete transmission poles have the advantages of low installation and maintenance costs, appropriate delivery time, and high corrosion resistivity. Typically, these poles are designed to resist synoptic wind loading. Current design codes do not consider the effect of high intensity wind (HIW) events in the form of downbursts and tornadoes on pre-stressed concrete poles despite the fact that those weather events are the main cause of failure of transmission line structures. The first comprehensive study conducted to assess the behaviour of pre-stressed concrete transmission poles under HIW is presented in this …

Bi-Directional Cyclic Behaviour And Liquefaction Analysis Of A Silica-Carbonate Sand, Keyvan Mirbaha

Electronic Thesis and Dissertation Repository

The cyclic behavior and liquefaction behavior of reconstituted samples of a local silica-carbonate sand are examined by performing monotonic and cyclic simple shear tests in addition to bender element shear wave velocity measurements. Shear wave velocity was found to vary with effective overburden stresses by an average power of 0.25. Maximum shear modulus (G_max) was also computed from the shear wave velocity measurements and a correlation was developed between G_max, effective stress and void ratio. Small strain and cyclic strain dependent shear modulus of the soil were determined, and shear modulus reduction curves were obtained. The …

Seismic Performance Of Steel Helical Piles, Moustafa K. El-Sawy

Electronic Thesis and Dissertation Repository

Recent earthquakes have highlighted the need for safe and efficient construction of earthquake resilient structures. Meanwhile, helical piles are gaining popularity as a foundation for new structures and retrofitting solution for existing deficient foundations due to their immense advantages over conventional driven pile alternatives. In addition, helical pile foundations performed well in recent earthquakes, proving they can be a suitable foundation option in seismic regions. The objective of this thesis is to evaluate the seismic performance of helical piles by conducting full-scale shaking table tests and nonlinear three-dimensional numerical modeling using the computer program ABAQUS/Standard. The experimental setup involved installing …

Enumeration, Variability, And Transport Of Escherichia Coli In The Foreshore Reservoir And Surface Water At Freshwater Beaches, Laura J. Vogel

Electronic Thesis and Dissertation Repository

Beaches are of immense recreational, societal and economic value. This value, however, is considerably diminished by poor water quality. Fecal indicator bacteria (FIB) are measured at recreational beaches worldwide to assess the water quality. A beach closure or advisory is issued if FIB concentrations in surface water exceed recreational water quality standards. Due to the lengthy time required to enumerate FIB (24 – 96 hours), statistical and mechanistic models have been developed to predict water quality exceedances a priori and to better understand why and under what conditions water quality exceedances occur. These models as well as beach water quality …

Influence Of Turbulence On The Aerodynamics Of Low-Rise Buildings, Fakhruzzaman Arif

Electronic Thesis and Dissertation Repository

During extreme wind events, roofing failures may lead to damage of the whole structure. In order to alleviate the effect, surface pressure coefficients on the roofs have been extensively investigated. This research aims to determine the roof pressures acting on low-rise buildings with consideration of the effects of turbulence (terrain). Pressure measurements, as well as wind speed data, were taken at the Boundary Layer Wind Tunnel Laboratory (BLWTL) of the University of Western Ontario (UWO) to examine the influence of turbulence level (i.e., terrain condition) on the critical wind directions corresponding to the largest surface roof pressure coefficients for various …

Generic Numerical Tornado Model For Common Interpretation Of Existing Experimental Simulators, Anant Gairola

Electronic Thesis and Dissertation Repository

There are difficulties in making a common interpretation of results of similar experiments done in different experimental tornado simulation facilities. This is primarily because of the differences in vortex generation mechanisms utilized as well as geometric differences in these facilities. Therefore, in an attempt to facilitate a universal interpretation of results, a generic numerical tornado model, representing the three major existing experimental tornado simulators, is developed in this study. The three experimental simulators in consideration are VorTECH at Texas Tech University, Tornado Simulator at Iowa State University and WindEEE Dome at Western University as representatives of “Ward” type, “top-down” type …

The Development And Numerical Modelling Of A Representative Elemental Volume For Packed Sand, Ashraf Thabet

Electronic Thesis and Dissertation Repository

The motivation of this thesis is the development of simple microscopic-scale model (representative elemental volume; REV) that can be used to conduct flow and heat transfer simulations from which closure coefficients can be established for the volume-averaged transport equations for porous media (packed bed). The thesis provides a brief introduction to the computational technique adopted for the geometric generation of the REV (YADE), followed by a parametric study undertaken to reveal the minimum number of particles inside the REV that are required to mimic the appropriate physics. Additional analysis was conducted with the goal of determining the influence of deviation …

Time-Lapse Electrical Resistivity Tomography For Mapping In Situ Smouldering Remediation (Star), Lais Muchatte Trento

Electronic Thesis and Dissertation Repository

Time-lapse Electrical Resistivity Tomography (ERT), a surface geophysical technique, was applied for the first time to monitor the first full-scale application of Self-sustaining Treatment for Active Remediation (STAR) at a coal tar contaminated site. STAR is a self-sustaining smouldering technology that destroys contaminants in situ by combustion, generating heat, water, and combustion gases. ERT is used as a complementary source of information to support conventional temperature and gas concentration data collected during STAR operations. A shallow (2.4 mbgs) and a deep (7.8 mbgs) treatment cell were monitored, with 2D surface resistivity surveys conducted before, during and after treatment. Two 36 …

A Study On Hydraulic Conductivity Of Fine Oil Sand Tailings, Mingyue Liu

Electronic Thesis and Dissertation Repository

In oil sand waste tailings pond, the gravity segregation takes place, where coarse particles settle relatively more quickly than fine particles, and a stable suspension, known as the mature fine tailings (MFT), is formed. Compression of MFT appears to be very slow, and MFT remains suspended in tailings pond for decades due to the low permeability. Large volumes of MFT continually accumulate in tailings ponds, and therefore MFT storage requires a large containment pond, which generates environmental concerns and leads to MFT management challenges. Hydraulic conductivity is one of the most important properties of MFT because it controls consolidation behaviors. …

Analysis Of Framing Failures In Wood-Frame Residential Roofs Under Wind Load, Sarah A. Stevenson

Electronic Thesis and Dissertation Repository

Wood-frame residential roof failures are among the most common and expensive types of tornado damage. Hip roofs are commonly understood to be more resilient during extreme wind in relation to gable roofs. However, inspection of damage survey data from recent tornadoes has revealed a previously unstudied failure mode in which hip roofs suffer partial failure of the framing structure. This research focuses on proving the concept of framing failures in hip roofs. Evidence of partial framing failures and statistics of their occurrence are explored and discussed, and common roof design and construction practice is reviewed. Two-dimensional finite element models are …

Pressure Equalization Of Wind-Induced Pressures On Residential Vinyl Siding Cladding In Full-Scale, Randy A. Van Straaten

Electronic Thesis and Dissertation Repository

Residential vinyl siding cladding system failures have been observed in high wind events. North American vinyl siding design standards allow a 64% pressure equalization factor, which yield relatively low wind load resistance for these products. The allowance is based on testing, which is questioned based on the literature review. The modified discharge equation analytical model, developed by others, accurately predict extent of pressure equalization found in scaled wind tunnel measurements. The model provides value in informing testing standards, product design and forensic investigations. However, it has only been validated based on scaled wind tunnel testing which may present scaling effect …

Estimation Of Turbulence Effects On Wind-Induced Suctions On The Roof Of A Low-Rise Building, Chieh-Hsun Wu

Electronic Thesis and Dissertation Repository

The effects of turbulence in the atmospheric boundary layer (ABL) on surface pressures of a typical low-rise building roof are investigated in this thesis. A 1/50 geometrically-scaled model of the Texas Tech University Wind Engineering Field Research Lab (WERFL) building model is used for pressure measurements in wind tunnel experiments. ABL wind turbulence intensities ranging from about 10% to 30%, and length scales ranging from 6 to 12 times of the building height (H) are generated. The effects of ABL turbulence on the mean roof pressures within the separated flow are explained from the time-averaged Navier-Stokes equations. The pressure fields …

Static And Dynamic Properties Of Controlled Low-Strength Materials Incorporating Treated Oil Sands Waste, Ahmed Mneina

Electronic Thesis and Dissertation Repository

Controlled Low-Strength Materials (CLSM) is a self-compacted self-leveling cementitious material with compressive strength of 8.3 MPa or less. It is used as an alternative of soil backfill materials in geotechnical and infrastructure applications. This study investigates the effects of incorporating treated oil sand wastes (TOSW) as a partial replacement of sand or fly ash on fresh and hardened properties of CLSM. In addition, the environmental impact of the proposed new mixtures was evaluated. The results show that CLSM mixtures incorporating TOSW had satisfied the limits and requirements of ACI committee 229 for CLSM with no environmental hazards. The incorporation of …

Treatment Of Oil Sands Process-Affected Water Using Activated And Surface Modified Petroleum Coke For Organic Compounds Recovery, Hojatallah Seyedy Niasar

Electronic Thesis and Dissertation Repository

Each day large volumes of oil sands process-affected water (OSPW) are being produced during the extraction of bitumen in oil sands industry in northern Alberta. OSPW contains different polyaromatic hydrocarbons which not only are the major source of toxicity in OSPW, but also create operational problems such as corrosion of the equipment during bitumen recovery process. Therefore, these compounds need to be removed prior to the recycle of the OSPW. In this research, petroleum coke (PC) as an abundant, inexpensive adsorbent was selected as an adsorbent for recovery of chemicals from OSPW. The surface area and adsorption capacity of PC …

Liquefaction Susceptibility Analysis Of Fraser River Sand In Miniature Cone Penetration Tests And Cyclic Direct Simple Shear Tests, Stephen Jones

Electronic Thesis and Dissertation Repository

The cone penetration test (CPT) and, its geophone-equipped form, the seismic cone penetration test (SCPT) are increasingly used site investigation techniques to determine in-situ geotechnical properties of soil profiles as well as liquefaction susceptibility in seismically active locations. The use of experimental techniques, most notably miniature cone penetration testing (MCPT), can be used to recreate these in-situ tests in a controlled laboratory setting.

In this study, MCPT tests are completed using Fraser River sand to determine cone tip and sleeve frictional resistances as well as shear wave velocity measurements and are validated using in-situ SCPT tests and existing soil classification …

Performance Characterization Of Coagulation Pretreatment For Two Industrial Effluents, Jing Wan

Electronic Thesis and Dissertation Repository

In this work, performances of coagulation and flocculation were tested for two different industrial effluents. Coagulation-Flocculation and activated carbon adsorption were applied for the remediation of oil sands process-affected water (OSPW), generated from oil sands operations in Alberta, Canada. OSPW is a complex mixture of suspended solids, various suspended and dissolved organic compounds. Alum and natural coagulant Opuntia ficus-indica (OFI) were used as the coagulants, and the process was optimized to improve the removal of turbidity and dissolved organic carbon (DOC). The maximum removal of 98% and 63% in turbidity and DOC from OSPW, respectively occurred at pH=6.32, with an …

Regeneration Potential Of Activated Petroleum Coke For Application In Oil Sands Process-Affected Water, Sreejon Das

Electronic Thesis and Dissertation Repository

Cost effective regeneration of spent adsorbent is crucial for large scale application of adsorption as a viable separation process. While adsorption studies are abundant in literature, systematic and comprehensive regeneration studies are seldom reported in open literature. A proprietary activated carbon from petroleum coke was used for the removal of model naphthenic acids (NAs) and organic compounds from oil sands process-affected water (OSPW). A systematic and comprehensive study was conducted to regenerate the adsorbents. Methanol with aqueous NaOH (pH adjusted to around 12) was applied to regenerate the spent commercially available granular activated carbon (GAC) and activated petroleum-coke (APC). Optimization …

Morphodynamic Response Of Spencer Creek To Large Precipitation Events And Channel Modifications: A Case Study, Emily Mae Martin

Electronic Thesis and Dissertation Repository

Severe weather events are occurring more frequently with extreme repercussions as our climate changes. Rainfall events of large magnitudes can lead to instability of river banks, riverbed erosion, and alterations in stream planform alignment. It is important to understand the hydraulic and geomorphic response of rivers and streams to storm events to predict long term morphological change, protect hydraulic structures, and manage aquatic ecosystems. The goal of this thesis is to examine the influence of precipitation events of varying magnitude on the morphodynamic processes of an urban creek. Four events are simulated: a constant averaged flow of 1.249 m3/s representative …

Tensile And Impact Behaviour Of Shape Memory Alloy Fibre Reinforced Engineered Cementitious Composites, Mohamed Ali El-Sayed Mahmoud Ali

Electronic Thesis and Dissertation Repository

Extreme loading events such as impact, blast, and earthquakes have often led to partial or total collapse of structures, associated with economic and human life loss. Therefore, civil engineers have been seeking innovative materials and systems that would allow designing resilient and smart structures which can withstand such catastrophic events. Recently, engineered cementitious composites (ECC) and shape memory alloys (SMA) have emerged as strong contenders in the production of smart and resilient structural systems.

The aims of this study are to explore the possible synergy between ECC and SMA for developing a novel hybrid fibre-reinforced ECC incorporating randomly dispersed SMA …

System Reliability Analyses And Optimal Maintenance Planning Of Corroding Pipelines, Changqing Gong

Electronic Thesis and Dissertation Repository

The failure of corroding pipeline joints may induce severe consequences. However, maintenance is expensive due to the cost of excavating and repairing a single joint and typically a significant number of joints that need repair. It is central to develop an optimal cost-effective maintenance strategy that balances cost and safety. A key component of the strategy is the reliability based condition evaluation of pipeline joints. The focus of the research reported in this thesis is therefore developing efficient reliability assessment methods for pipeline individual joints, and developing an optimal maintenance framework for the entire pipeline system.

First, efficient system reliability …

Liquefaction Assessment Of Carbonate-Silica Silty Sands Using Energy, State Parameter And Shear Wave Velocity, Naemeh Naghavi

Electronic Thesis and Dissertation Repository

The liquefaction behaviour and dynamic properties of reconstituted natural carbonate-silica silty sand samples were investigated in a series of monotonic and cyclic triaxial tests. The critical state parameters of the mixtures with different levels of fines were obtained through monotonic triaxial compression tests. Bender element tests were performed at the consolidation stage to characterize soil’s initial state and small strain properties. The results demonstrated that soil contraction capacity, liquefaction potential and undrained brittleness increase by increasing the state parameter. A general correlation between shear wave velocity and state parameter was established. The susceptibility and triggering of liquefaction under cyclic loading …

Comparative Investigation Of Bored And Continuous Flight Auger Piles With Consideration Of Green Concrete, Mahmoud Kassem

Electronic Thesis and Dissertation Repository

Bored and continuous flight auger (CFA) piles are two widely used cast in place reinforced concrete pile types that are constructed employing different techniques, which affect their performance and capacity. However, both are classified as non-displacement piles and are designed accordingly using the same method. Therefore, the objective of this work is to comparatively investigate the axial and lateral performance of bored and CFA piles installed in sand. In addition, the potential of constructing sustainable piles utilizing green concrete mixture that incorporates treated oil sand waste (TOSW) was investigated. Fresh and hardened properties along with durability performance of CFA concrete …