Self-Healing Of Concrete Under Diverse Environmental Exposure, Ahmed Ramadan Suleiman

Electronic Thesis and Dissertation Repository

Self-healing efficiency of cement-based materials has so far been evaluated mostly through the healing of surface cracks, without adequately capturing the dominant effects of environmental exposure or accurately quantifying the volume of cracks healed. In addition, the effects of diverse additions such as silica-based materials, swelling agents, superabsorbent polymers, and carbonating minerals on self-healing performance under different environmental exposure, remain largely unexplored.

In this dissertation, multiple test methods were used to investigate self-healing of cracks in cement mortar incorporating metakaolin, bentonite, fly ash, superabsorbent polymers, and calcium carbonate microfiller under different environmental exposure (i.e. cold and hot temperatures, high and …

Role Of Groundwater-Lake Interactions On The Behavior Of Chemicals In A Nearshore Aquifer, Sabina Rakhimbekova

Electronic Thesis and Dissertation Repository

It is well recognized that groundwater-surface water interactions play an important role in controlling the flux of groundwater-derived inorganic chemicals to surface waters. While these interactions have been well-studied in marine, and river and stream settings, the influence of these interactions on chemical fluxes to large lakes is poorly understood. Nearshore aquifers adjacent to inland coastal waters, such as the Great Lakes, are characterized by dynamic flow patterns and the mixing of groundwater and lake water, which have distinct chemical compositions. This sets up an important reaction zone in the nearshore aquifer that may modify the fate of groundwater-derived chemicals …

Partial Nitritation Anammox Process For Sidestream Wastewater Treatment In Mabr Technology, Panagiota Stamatopoulou

Electronic Thesis and Dissertation Repository

There has been an increased interest in alternative wastewater treatment systems to improve nutrients removal and energy consumptions while achieving acceptable discharge limits. Wastewater treatment plants (WWTP) have shifted their interest in treating the sidestream wastewater; a reject liquid post anaerobic digestion, rich in ammonium-nitrogen. A dedicated sidestream wastewater treatment unit has become an attractive option with the finding of a relatively new species of bacteria, anaerobic ammonium oxidizers (anammox), able to convert ammonium and nitrite into nitrogen gas. However, anammox bacteria are sensitive in environmental changes, and in combination with their low growth rate, it is challenging to establish …

Miniature Cone Penetration Tests With Shear Wave Velocity And Electrical Resistivity Measurements In Characterization Of Silica Sand, Ronit Ganguly

Electronic Thesis and Dissertation Repository

Geotechnical engineering design and analysis require sound identification and characterization of in-situ soil. To characterize is to gather information about the engineering properties of a particular soil which will affect the performance of any structure built on it. As a result of complications associated with the retrieving of undisturbed samples of cohesionless soils, calibration chamber-based experiments under controlled laboratory settings are used for the determination of several geotechnical engineering parameters. The capability of a reduced-scale calibration chamber-based cone penetration testing system along with shear wave velocity and electrical resistivity measurements, to better characterize in-situ soil is examined in this study. …

Anaerobic Digestion Modeling Of A High Rate Acidification Pre-Treatment Technology, Connor Pritty

Electronic Thesis and Dissertation Repository

Through the application of a computerized model (BioWin), anaerobic co-digestion (AcoD) of source separated organics (SSO) and a high rate acidification technology (pretreatment) for a conventional wastewater treatment plant was reviewed. Through this combined approach of high rate acidification, and co-digestion techniques it was found that the experimental modeling scenarios offered increases when compared to the existing base scenario production levels. With the addition of the high rate acidification technology and application of source separated organics the maximum increases in biogas production came when an OLR of 5.24 kg-COD/m³/day and 97g COD/L/d was experimentally modeled. It is therefore, recommended that …

Numerical And Semi-Analytical Estimation Of Convective Heat Transfer Coefficient For Buildings In An Urban-Like Setting, Anwar Demsis Awol

Electronic Thesis and Dissertation Repository

Urban building arrangements such as packing density, orientation and size are known to influence the microclimate surrounding each building. Studies on the impact of urban microclimatic changes on convective heat transfer coefficient (CHTC) from a stock of buildings, however, have been rare in surveyed literature. The present study focuses on numerical and analytical investigation of CHTC from building-like models with homogeneous set of equal and unequal planar and frontal densities. Consequently, the study discusses the CHTC response in relation to broader changes in the urban surface form. Part of the process involves the development of a simplified one-dimensional semi-analytical CHTC …

Spatial And Temporal Characteristics Of Temperature-Precipitation Covariability Across Canada In A Changing Climate, Harsimrenjit Singh

Electronic Thesis and Dissertation Repository

Changes in the regional characteristics of temperature and precipitation can intensify the occurrence and severity of extreme events such as rain-on-snow induced flooding, droughts and wildfires. Analyzing these climate variables in isolation without considering their interdependencies might result in severe underestimation of their combined effects. In this study, copula functions are used to describe the joint behaviour of temperature and precipitation across Canada over a historical period of 1910-present using observations and further till the end of the 21st century using three large ensembles of regional climate models. Moreover, given the lack of observation data over Canada, gridded datasets are …

High Strain Dynamic Test On Helical Piles: Analytical And Numerical Investigations, Mohammed Fahad Alwalan

Electronic Thesis and Dissertation Repository

Helical piles are currently considered a preferred foundation option in a wide range of engineering projects to provide high compressive and uplift resistance to static and dynamic loads. In view of the large capacity of large diameter helical piles, there is a need to determine their capacity using accurate and economically feasible testing techniques. The capacity of piles is usually determined by conducting a Static Load Test (SLT). However, the SLT can be costly and time consuming, especially for large capacity piles. The High Strain Dynamic Load Test (HSDT) evaluates the pile capacity using dynamic measurements generated through subjecting the …

Application Of Bayesian Networks To Integrity Management Of Energy Pipelines, Wei Xiang

Electronic Thesis and Dissertation Repository

Metal-loss corrosion and third-party damage (TPD) are the leading threats to the integrity of buried oil and natural gas pipelines. This thesis employs Bayesian networks (BNs) and non-parametric Bayesian networks (NPBNs) to deal with four issues with regard to the reliability-based management program of corrosion and TPD. The first study integrates the quantification of measurement errors of the ILI tools, corrosion growth modeling and reliability analysis in a single dynamic Bayesian network (DBN) model, and employs the parameter learning technique to learn the parameters of the DBN model from the ILI-reported and filed-measured corrosion depths. The second study develops the …

Comparative Assessment Of Downscaling Methods And Application Towards Analysis Of Climate Change Impact On Urban Regions, Markus Eichenbaum

Electronic Thesis and Dissertation Repository

Global climate models (GCM) are sophisticated numerical models used to make long term climate projections. However, the resolution of their output is too coarse for climate change related local impact studies on urban regional scales. Downscaling efforts are taken to address this and increase GCM projection resolution. Physical Scaling (SP) downscaling methodology attempts to incorporate the physical basis of dynamical downscaling efforts with the computational efficiency of statistical methods. In this study, North American Regional Reanalysis surface skin temperature and precipitation data for a 1°x1° region centered on Houston, TX are downscaled to a resolution of 500m via SP and …

Bioremediation Of Refinery Desalter Effluent Using Debaryomyces Hansenii And Parachlorella Kessleri, Leila Azimian

Electronic Thesis and Dissertation Repository

Crude oil desalting operations produce an effluent stream which is challenging to treat due to its salt, heavy metal and hydrocarbon content. Consequently, desalter effluent (DE) is usually diluted into other effluent streams and sent to conventional wastewater treatment plants which may lead to upsets the plant operation.

In this study, a novel microbial approach was applied which investigated DE treatment using halotolerant yeast Debaryomyces hansenii (LAF-3 10 U) or the environmentally robust micro-algae Parachlorella kessleri strain CPCC 266. The effect of these two different approaches on both synthetic and actual DE was investigated in both batch and/or continuous mode. …

Modal Analysis And Analytical Modeling Of Tornado-Like Vortices, Mohammad Karami

Electronic Thesis and Dissertation Repository

Regardless of the type of vortex chamber, many tornado simulators generate flows that reveal similar flow patterns and a general agreement on the variations of the flow structures with swirl ratio (the ratio of tangential velocity to radial velocity) was achieved. However, very little is known about the underlying physics of the flow, mostly of the fluctuating one, as the previous studies have mainly focused on qualitative flow visualization and the quantitative description of the mean flow.

Herein, coherent structures in tornado-like vortices are extracted using modal decomposition techniques. Modal analysis helps us to better understand the complex vortex dynamics …

Analysis Of Roofs Of Wooden Houses Under Uplift Wind Loads- Analytical Solution, Retrofit, And Reliability Analysis, Adnan Farouk Enajar

Electronic Thesis and Dissertation Repository

Observations of post-hurricane events indicate that light-frame wood houses are vulnerable to failure

Observations of post-hurricane events indicate that light-frame wood houses are vulnerable to failure due to the inability of their connections to provide sufficient transfer of uplift wind loads from the roof of the house to the foundation. One of these connections is the roof-to-wall connection (RTWC), which connects roof trusses to the top plate members of the walls. This issue has been investigated through full-scale testing at the Insurance Research Lab for Better Homes. This thesis describes the detailed finite element modelling performed for this full-scale testing …

An Integrated Framework To Assess Compound Flood Risks For Interdependent Critical Infrastructure In A Coastal Environment, Ying Zhang

Electronic Thesis and Dissertation Repository

Compound flooding refers to flood events caused by multiple factors, including marine processes (e.g. storm tides and waves), hydrometeorological signals (e.g. rainfall and river flows) among others. Saint Lucia is a tropical island in eastern Caribbean Sea, which is frequently affected by weather-related extreme events such as tropical storms and the associated risks are exacerbated due to its mountainous topography and high concentrations of infrastructure and human communities close to the coast. At the southern coast of Saint Lucia, significant infrastructures such as Hewanorra International Airport and Vieux Fort Seaport, and human settlements such as towns of Vieux Fort and …

Experimental And Numerical Evaluation Of A Novel Piling System For Sound Wall Applications, Daniel Mroz

Electronic Thesis and Dissertation Repository

Drilled shafts are conventionally used as foundations for sound walls. However, steel piles can provide faster installation and immediate utilization. The purpose of this research program is to evaluate a novel pile concept which comprises an H-pile modified to better resist typical load patterns faced by sound wall piles including lateral force and moment from wind and uplift force from adfreeze. The modifications include one or two plates welded to the pile and soil anchors (nodes) welded along the pile flange.

A full-scale pile load testing program was performed on sixteen piles which included monotonic and cyclic lateral load tests …

The Effect Of Stiffness Anisotropy Of A Glacial Clay On The Behaviour Of A Shallow Wind Turbine Foundation, Jesús A. González-Hurtado

Electronic Thesis and Dissertation Repository

Shallow wind turbine foundations are designed based on investigations of the ultimate, serviceability and fatigue limit states. The serviceability limit state design approaches in particular are based on simple isotropic elastic half-space analyses that ignore coupling between loading directions, and soil non-linearity and elastic anisotropy. Many of the wind farms in Ontario are constructed around the Great Lakes basin and a number of these areas are characterized as stiff clayey glacial tills. It is recognized that many of these glacial materials exhibit some degree of strength, stiffness and fabric anisotropy. This research aimed to characterize the anisotropic geotechnical properties of …

Long-Term Deflections Of Reinforced Concrete Beams, Ziad Elaghoury

Electronic Thesis and Dissertation Repository

The CSA A23.3 code provisions compute the long-term deflection of reinforced concrete flexural members by applying a multiplier to the short-term deflection, essentially ignoring the creep and shrinkage characteristics of concrete. The CAC Concrete Design Handbook presents more elaborate methods, but fails to account for the factors that influence the creep and shrinkage of concrete.

The four widely recognized models for computing creep and shrinkage strains yield predictions that differ by up to 30%. Studies by others to assess the accuracy of the models apply different of statistical analyses do different datasets and so yield contradicting outcomes, making it difficult …

Effects Of Building Scale Parameters On Pressure Equalization Capacity Of Roof Paver Systems, Matthew Sparks

Electronic Thesis and Dissertation Repository

Roof pavers are commonly installed with a cavity beneath the paver that develops an internal suction pressure. These cavity pressures reduce the net pressure felt by a roof paver subject to uplift. Paver-scale parameter effects are well-understood, in this study, the effects of changing building-scale parameters such as height, aspect ratio, afterbody length, small and large scale roof obstructions, and paver to roof size ratio on cavity pressures are investigated. To do so pressure measurements were taken at the University of Western Ontario’s Boundary Layer Wind Tunnel Laboratory on a modular flat roof building model at four different heights with …

A Methodology For Assessing Dynamic Resilience Of Coastal Cities To Climate Change Influenced Hydrometeorological Disasters, Angela Peck

Electronic Thesis and Dissertation Repository

Confronted with rapid urbanization, intensified tourism, population densification, increased migration, and climate change impacts, coastal cities are facing more challenges now than ever before. Traditional disaster management approaches are no longer sufficient to address the increased pressures facing urban areas. A paradigm shift from disaster risk reduction to disaster resilience building strategies is required to provide holistic, integrated, and sustainable disaster management looking forward. To address some of the shortcomings in current disaster resilience assessment research, a mathematical and computational framework was developed to help quantify, compare, and visualize dynamic disaster resilience. The proposed methodological framework for disaster resilience combines …

Studies On The Liquefaction Behaviour Of Tailings And Natural Sand, Guillermo Riveros

Electronic Thesis and Dissertation Repository

This series of studies explores the liquefaction behaviour of cohesionless mine tailings and a natural sand and examines the effectiveness of a bio-mediated treatment for the mitigation of liquefaction. The first study investigates the flow liquefaction failure of the Fundão tailings dam (2015) by analytically assessing the stability of the breached abutment, accounting for the specific triggering mechanism and subsequent strength loss that led to its collapse. The second study evaluates the static liquefaction behaviour of gold mine tailings and its correlations with shear-wave velocity through an experimental program comprised of direct simple-shear and bender element tests. The last study …

Performance Of Pressure Grouted Helical Piles Under Monotonic Axial And Lateral Loading, Mohamed A. Mansour

Electronic Thesis and Dissertation Repository

The pressure grouted helical pile (PGHP) is an innovative pile foundation system that allows a significant increase in the helical pile capacity with some additional cost. The pile is constructed by applying pressurized grout during the installation of a closed ended helical pile through two grout nozzles welded to the hollow pile shaft. Torquing PGHP into the ground allows the grout nozzles to create a cavity around the pile shaft. The cavity then expands under the effect of pressurized grout and helix rotation. This thesis presents a comprehensive laboratory study and three-dimensional finite element analysis to investigate the effects of …

Field Trials Of Ex Situ Smouldering Treatment (Starx) Of Oil Sludge, Cody Murray

Electronic Thesis and Dissertation Repository

Growing environmental concern and regulations around petroleum producing and refining facilities, along with the divesting of legacy properties, have necessitated the need for rapid, high capacity, and cost-effective treatment technologies for remediating these sites and their produced wastes. Self-sustained liquid smouldering – known as STAR technology - has been studied extensively at small scales and has been proven as an effective in situ remediation technique for heavy hydrocarbons. However, STAR as a large-scale ex situ waste disposal method (STARx) has yet to be demonstrated. Here STARx is evaluated for the first time in soil pile configurations, using an engineered base …

Field-Scale Implementation Of Sulfidated Nano Zerovalent Iron For In-Situ Remediation, Ariel Nunez Garcia

Electronic Thesis and Dissertation Repository

As far back as the mid-1990s, biogenic sulfidation has been observed during the implementation of iron-based materials for groundwater remediation. This phenomenon has largely been a consequence of natural biogeochemical processes and the prospects of utilizing engineered sulfidated zerovalent iron (ZVI) particles – nano- and/or micro- sized – were not extensively explored. More recently sulfidation of zerovalent iron (ZVI) particles has received considerable attention, highlighting the benefits that engineered/abiotic sulfidation can offer to nZVI, but to date, no field demonstration of the technology has been conducted. The first part of this thesis aims to report the unique challenges and unanswered …

Structural Optimization Of Cable-Stayed Bridges Considering The Action Of Permanent And Transitory Loads, Carolina Almeida Novaes Dos Santos

Electronic Thesis and Dissertation Repository

Cable-stayed bridges are complex structures with several advantages such as aesthetical appeal, economic use of materials, and efficient construction method. Due to these advantages and the extensive knowledge gained from projects over the years, longer cable-stayed bridges are being constructed. As span lengths increase, structures become more flexible, which makes the accurate evaluation of wind loads critically important in the design of cable-stayed bridges. A large number of variables are involved in the design of cable-stayed bridges. Those include overall geometric dimensions, cross-sectional dimensions, number of stay-cables and pre-tensioning forces to be applied to the cables. Taking all variables into …

Optimization Of Window Confirguration In Buildings For Sustainable Thermal And Lighting Performance, Meseret Tesfay Kahsay

Electronic Thesis and Dissertation Repository

In recent years, there is an urban architectural evolution towards significant use of glazing in high-rise buildings. Windows play a critical role in moderating the elements of the climate. Although good for outdoor viewing and daylighting, glazing has very little ability to control heat flow and solar heat gain. As a result, about 20 - 40% of the energy in a building is wasted through windows. Finding an optimal configuration of windows is a complex task due to its conflicting objectives, such as outdoor view, daylighting, and thermal comfort demands. Further buildings interact with the microclimate in a complex manner, …

Risk Analysis Of Natural Gas Distribution Pipelines With Respect To Third Party Damage, Joseph S. Santarelli

Electronic Thesis and Dissertation Repository

The objective of this study is to develop a quantitative method of evaluating the risk of third party damage (TPD) on natural gas distribution pipelines using available industry data and practical engineering experience. A risk model for TPD of gas distribution pipelines is developed to allow for a more robust decision making process and better prioritization of the allocation of resources for operators of natural gas distribution pipelines. The model consists of likelihood and consequence classification procedures to estimate the severity of TPD events within an area.

The TPD model consists of a fault tree (FTA) model to estimate the …

The Effect Of Low Temperature And Low Light Intensity On Nutrient Removal From Municipal Wastewater By Purple Phototrophic Bacteria (Ppb), Peyman Dalaei

Electronic Thesis and Dissertation Repository

There has been increased interest in alternative wastewater treatment systems to improve nutrient recovery while achieving acceptable TCOD, TN, and TP discharge limits. Purple phototrophic bacteria (PPB) have a high potential for simultaneous nutrient removal and recovery from wastewater. This study evaluated the PPB performance and its growth at different operating conditions with a focus on HRT and light optimization using a continuous-flow membrane photobioreactor (PHB). Furthermore, the effect of low temperature on PPB performance was assessed to evaluate the PPB’s application in cold-climate regions. In order to evaluate PPB performance, TCOD, TN, and TP removal efficiencies and Monod kinetic …

Performance-Based Design Of Fire-Exposed Reinforced Concrete Elements Using An Equivalent Standard Fire, Robert T. Kuehnen

Electronic Thesis and Dissertation Repository

Fire events represent one of the most severe loading scenarios for reinforced concrete (RC) buildings. In lieu of intensive computational analysis, designers need simplified methods to assess RC members exposed to natural fires. This thesis focuses on the development of a time equivalent (t_e) to replace a natural fire with an equivalent standard fire, allowing for the implementation of existing simplified analysis methods.

The proposed t_e is based on the average internal temperature profile (AITP) that develops in a section during fire. Two AITP t_e are proposed to accurately or conservatively approximate the AITP of …

Effect Of Coagulant Recycling On Chemically Enhanced Primary Treatment Performance, Tulip Chakraborty

Electronic Thesis and Dissertation Repository

Chemically enhanced primary treatment (CEPT) process is a promising method for carbon redirection and improving the performance and efficiency of wastewater treatment processes. CEPT is employed to precipitate colloidal and suspended matter from wastewater; however, this requires a significant amount of coagulant and produces large volumes of sludge. Coagulant recovery (CR) from the precipitated sludge has the potential to reduce sludge quantities, associated costs for disposal of sludge, cost of dosing fresh coagulant by regenerating and purifying the coagulant before reuse. This research was conducted to understand the feasibility and implications of CR in municipal wastewater.

In order to evaluate …

Future Changes Of Hydroclimatic Extremes In Western North America Using A Large Ensemble: The Role Of Internal Variability, Mohammad Hasan Mahmoudi

Electronic Thesis and Dissertation Repository

Increases in the intensity and frequency of extreme events in Western North America (WNA) can cause significant socioeconomic problems and threaten existing infrastructure. In this study we analyze the impacts of climate change on hydroclimatic extremes and assess the role of internal variability over WNA, which collectively drain an area of about 1 million km². We used gridded observations and downscaled precipitation, maximum and minimum temperature from seven General Circulation Models (GCMs) that participated in the Coupled Model Intercomparison Project Phase 5 (CMIP5) and a large ensemble of CanESM2 model simulations (CanESM2-LE; 50 members) for this analysis. Spatial …