Geoelectrical Signatures Of Acid-Generating Mine Waste Rock, Difan Su

Electronic Thesis and Dissertation Repository

Acid mine drainage (AMD) contamination associated with waste rock piles (WRPs) at mining sites is a global concern, and understanding the generation and release of AMD from these piles is highly desirable. Traditional WRP monitoring techniques involve the installation of monitoring wells and periodic core sampling; however, these approaches are invasive, expensive and can only provide data with limited spatial and temporal resolution. An attractive alternative is non-invasive geophysical techniques that can provide non-invasive and continuous information on subsurface features and processes. This thesis aims to investigate the feasibility of the spectral induced polarization (SIP) method for monitoring changes in …

Physical Investigation Of Downburst Winds And Applicability To Full Scale Events, Federico Canepa

Electronic Thesis and Dissertation Repository

Thunderstorm winds, i.e. downbursts, are cold descending currents originating from cumulonimbus clouds which, upon the impingement on the ground, spread radially with high intensities. The downdraft phase of the storm and the subsequent radial outflow that is formed can cause major issues for aviation and immense damages to ground-mounted structures. Thunderstorm winds present characteristics completely different from the stationary Gaussian synoptic winds, which largely affect the mid-latitude areas of the globe in the form of extra-tropical cyclones. Downbursts are very localized winds in both space and time. It follows that their statistical investigation, by means of classical full scale anemometric …

Erosion Control Of Steep Open Channels Using Articulated Concrete Blocks, Mohammadomid Marandi

Electronic Thesis and Dissertation Repository

Overtopping flow can undermine the stability of hydraulic structures including embankments and spillways through the shear stress and the subsequent soil erosion. Increased flow velocity can cause scour, which can result in the failure of dams, bridges, and overall open channel hydraulic structures. Sediment transport is another crucial issue in open channels that can cause severe socioeconomic and environmental consequences. Two general approaches are commonly considered for scour prevention. The first approach involves flow modifications to minimize the corresponding effects on the structures. The second approach is associated with bed armoring and placing physical barriers on the natural bedding such …

Experimental Simulation Of Tornado-Like Vortices And Their Impact On High-Rise Buildings, Arash Ashrafi

Electronic Thesis and Dissertation Repository

One of the most crucial research areas in wind engineering is tornadoes due to the widespread damages to infrastructure and the environment in North America and other parts of the world. The proper scaling of tornadoes in experimental facilities, generating tornado-like vortices (TLVs) is, therefore, an essential part of evaluating tornado-indued damages on engineered buildings. The capability of producing TLVs of length scales in the range between 1:300 and 1:150 inside the Wind Engineering, Energy and Environment (WindEEE) Dome at Western University has already been demonstrated using only one mode of the full potential of this simulator. A new mode …

Active Fluids: Rheological Properties And Response To Light Of Suspensions Of Synechocystis Sp. Cpcc 534, Zahra Habibi

Electronic Thesis and Dissertation Repository

Despite our current understanding of active fluid mechanics, more knowledge is required to fully understand their rheological properties, response to light, and details of the interactions between cells in diluted suspensions.

The focus of this thesis is on investigating the rheological properties of suspensions of cyanobacterium Synechocystis sp. CPCC 534 under shear, induced by stirring. Experiments were conducted at different stirring rates and results are compared with the stationary condition. A notable increase in growth and biomass of Synechocystis sp. under various shear conditions was observed and the yield was nearly doubled. Besides, the data showed Newtonian behavior for suspensions …

Experimental Study Of Tornado-Induced Pressures, Aya Kassab

Electronic Thesis and Dissertation Repository

The increased devastation associated with tornadic flow-fields in terms of human lives or destruction of properties and their subsequent economic losses highlights the significance of understanding the tornado vortex structure, particularly near the ground where the majority of this destruction happens. While the body of research in this area is increasing there is a lack of resolution associated with physical near-surface measurements in tornado-like vortices (TLVs) and the effects of translation, surface roughness, and surface vortex dynamics are not yet well understood.

In order to address these gaps, high spatial and temporal surface pressure measurements were carried out at WindEEE …

Effect Of The C-Source And Cod/N On Nitrite And Partial Nitrate Denitrification, Ahmed Fathy Elyas Badia

Electronic Thesis and Dissertation Repository

The main objectives of this study were: (i) to investigate dynamic specific denitrification rates (SDNR) from nitrite at various chemical oxygen demand (COD) / nitrogen (N) ratios using municipal wastewater (MWW) and acetate, and to study the kinetic parameters, (ii) to investigate the dynamic specific denitrification rates (SDNRs) from nitrite at various COD/N ratios in a system that uses methanol as a complementary carbon source, and studying the effect in case if nitrate replaced nitrite, and (iii) to investigate and compare between the nitrite shunt and N-PDN-anammox technologies through studying the dynamic specific denitrification rates (SDNRs) from nitrate and nitrite …

Biomechanics Of Trees Under Extreme Wind Loading Events, Mojtaba Dargahi

Electronic Thesis and Dissertation Repository

For urban planners, arborists and foresters, understanding tree stability under self-weight and applied loads from wind and snow is important when developing management strategies to reduce the risk of damage from these abiotic agents. Current predictive approaches are generally empirical and based on a posteriori surveys of failures. A more rigorous engineering approach to understanding response phenomenon in trees subjected to extreme winds has been attempted herein. The size of trees and their architecture (shape and structure) greatly influence their mechanical stability under dynamic loading. Considering trees as porous media, wind loads on them are affected by their resistance to …

Tornado Occurrence Modelling And Equivalent Tornado Design Wind Profile For Canada, Qian Huang

Electronic Thesis and Dissertation Repository

The tornadoes can be devastating to structures and infrastructure systems. They can cause fatalities and economic losses. In this thesis, the tornado hazard for Canada is systematically assessed. The use of three spatial point processes (i.e., Poisson, zero-inflated Poisson, and negative binomial models) are first investigated in a hierarchical structure to predict the tornado occurrence rate by considering the annual cloud-to-ground lightning flash density and annual thunderstorm days as covariates. An existing historical tornado catalogue with reported tornado events up to 2009 is considered and the population bias effect in estimating the tornado occurrence rate is included. Both the Bayesian …

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 …

Modeling Of Suspended Sediment Concentration Using Conventional And Machine Learning Approaches, In Thames River, Canada, Issam Mohamed

Electronic Thesis and Dissertation Repository

Water resource management, planning, hydraulic design, environmental conservation, reservoir management and operation all require reliable information and data about Suspended Sediment Concentration (SSC). To predict such data, direct sampling and Sediment Rating Curves (SRC) are commonly utilized. Since direct sampling can be risky during extreme weather events and SRC cannot provide satisfactorily dependable results, engineers are trying to propose new precise fore-casting approaches. Various soft computing techniques have been applied to model different hydrological and environmental problems and have showed promising results in this regard. Although many studies have been performed to simulate the phenomena of SSC at numerous rivers …

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 …

Uncertainty Modeling In The Assessment Of Climate Change Impacts On Water Resources Management, Sohom Mandal

Electronic Thesis and Dissertation Repository

Climate change has significant impacts on water resource systems. The objective of this study is to assess climate change impacts on water resource management. The methodology includes (a) the assessment of uncertainty introduced by choice of precipitation downscaling methods; (b) uncertainty assessment and quantification of the impact of climate change on projected streamflow; and (c) uncertainty in and impact of climate change on the management of reservoirs used for hydropower production. The assessment is conducted for two future time periods (2036 to 2065 and 2066 to 2095). The study area, Campbell River basin, British Columbia, Canada, consists of three reservoirs …

Automated Control Flaw Generation Procedure: Cheakamus Dam Case Study, Bogdan Pavlovic

Electronic Thesis and Dissertation Repository

This thesis deals with the problem of aging hydropower infrastructure systems and system components, a problem that is very common across Canada. Flaws of common risk analysis methods are noted, and the need for new risk analysis approaches is identified. System dynamics simulation method is introduced as an implementation mechanism for the System Theoretic Process Analysis (STPA). STPA and its adaptation to complex hydropower systems are explained thoroughly. Fuzzy logic is used to model operator’s decision making. The main objectives of the research include the development of an automated generic approach that implements STPA and fuzzy logic for the investigation …

Application Of Treated Oil Sands Drill Cuttings Waste In Micropiles Construction, Moustafa Ahmed Raafat Mohamed Aboutabikh

Electronic Thesis and Dissertation Repository

A micropile is constructed by drilling a hole, placing a steel reinforcing element, grouting it using neat cement. However, cement production consumes energy and generates carbon dioxide. Implementing waste materials in construction applications represents a sustainable solution for many waste management problems. On the other hand, oil sands drill cuttings waste represents one of the most difficult challenges for the oil sands mining sector. Reducing the amount oil sands drill cutting waste sent to landfill offers one of the best solutions for waste management. This thesis presents an innovative solution for application of treated oil sands waste (TOSW) in grout …

Slope Stability Enhancement Of An Upstream Tailings Dam: Laboratory Testing And Numerical Modelling, Yazeed A. Alsharedah

Electronic Thesis and Dissertation Repository

Mine tailings are the byproduct of mining activities, which need to be disposed of once the ore is extracted. They can be disposed of in either dry or wet forms. The latter is most common with the tailings being disposed of in the form of slurry inside retention structures. The retention structure may be a natural, manmade, or built dam, which is the case in most of nowadays mining locations. In this thesis, improving the stability of an upstream tailings dam using soil additives is investigated. The experimental phase of this study involved laboratory tests conducted to characterize mine tailings …

Influence Of Waves On Groundwater Flows And Geochemistry In A Sandy Nearshore Aquifer: A Combined Field And Modelling Study, Spencer S. Malott

Electronic Thesis and Dissertation Repository

Waves are known to influence the flux of pollutants to coastal waters via groundwater discharge. This study combines field measurements with numerical groundwater modelling to evaluate the influence of a period of intensified wave conditions (wave event) on nearshore groundwater flows and geochemistry in a sandy freshwater beach. Comprehensive vertical nested pressure transducer data obtained over a 2.5 day isolated wave event reveal the development of transient groundwater flow recirculations through the nearshore aquifer combined with enhanced water exchange across the sediment-water interface (i.e., beach face). The wave-induced groundwater flows were simulated in FEFLOW using a phase-averaged wave setup approach …

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 …

Wind And Thermal Effects On Ground Mounted Photovoltaic (Pv) Panels, Chowdhury Mohammad Jubayer

Electronic Thesis and Dissertation Repository

A combination of Computational Fluid Dynamics (CFD) simulations and wind tunnel experiments are carried out to investigate the effects of wind on the aerodynamic loading and heat transfer of a ground mounted stand-alone photovoltaic (PV) panel with tilt angle of 25^o in open country atmospheric boundary layer. Several azimuthal wind directions are considered: Southern 0^o, Southwest 45^o, Northwest 135^o and Northern 180^o. Three dimensional Reynolds-Averaged Navier-Stokes (RANS) approaches with an unsteady solver using Shear Stress Transport (SST) k-ω turbulence closure are employed for the CFD simulations, whereas Particle Image Velocimetry (PIV) and …

Influence Of Water Chemistry Parameters On The Dissolution Rate Of The Lead (Ii) Carbonate Hydrocerussite, Caitlin Se Kushnir

Electronic Thesis and Dissertation Repository

This work has focused on the kinetic dissolution of the lead (II) carbonate hydrocerussite (Pb₃(CO₃)₂(OH)₂) under four pH conditions (7.5, 8, 9, 10), three dissolved inorganic concentrations (DIC; 10, 20, 50 mg C/L), and three initial hydrocerussite concentrations (10, 20, 50 mg/L) in batch experiments. Experiments were performed in at least duplicate to determine total dissolved lead dissolution curves at short time scales (hr.). All equilibrium dissolved lead concentrations were achieved in 40 minutes or less, and matched trends from previous studies; pH 7.5 and pH 10 corresponding to the highest and …

Hydrogeological And Thermal Sustainability Of Geothermal Borehole Heat Exchangers, S. Emad Dehkordi

Electronic Thesis and Dissertation Repository

Assessment of the current approach taken by guidelines and design methods of vertical closed loop heat exchangers shows that often groundwater flow is either disregarded or is not methodically incorporated. The state of scientific research in this arena reveals that overlooking the groundwater flow in the design procedure may not always be a correct assumption. The significance of advective heat transport compared to conduction is defined by the groundwater flux or Darcy velocity which heavily depends on the hydraulic conductivity of the ground, followed by the hydraulic gradient which has a relatively limited range. A sensitivity analysis on ground and …

Biofilm Control In A Fludized Bed Bioreactor (Fbbr) Treating Municipal Wastewater: Optimization, Modeling, And Nitrous Oxide (N2o) Emissions, Ahmed Eldyasti

Electronic Thesis and Dissertation Repository

Among the various biological wastewater treatment processes for industrial and municipal wastewater treatment, fluidized bed bioreactors (FBBR) demonstrate numerous advantages compared to suspended growth systems such as lower hydraulic retention time, high surface area and accordingly high biomass retention time, higher volumetric conversion rates, lower sensitivity to temperature, and less sludge production. Despite the numerous biofilm bioreactor configurations and system schemes that are currently available for a wide variety of environmental applications, the development and optimization of a stable biofilm that is capable of offering effective and integrated functions, i.e. biodegradation, biomass-liquid separation, and biomass retention along with a substantial …

Investigation Of Bio-Hydrogen And Bio-Methane Production From Thin Stillage, Noha El-Sayed Nasr

Electronic Thesis and Dissertation Repository

An evaluation of single-stage and two-stage anaerobic digestion processes for biomethane and biohydrogen production using thin stillage was performed to assess the viability of biohydrogen production from thin stillage and the impact of separating the acidogenic and methanogenic stages on anaerobic digestion with hydrogen production in the first stage. A comparative evaluation of anaerobic digester sludge (ADS) and acclimatized anaerobic digester sludge (AADS) for biohydrogen production was performed at various S°/X° ratios. The optimum range of S°/X° ratio for hydrogen production was found to be 1 to 2 gCOD/gVSS using conventional ADS and 3 to 6 gCOD/gVSS using AADS. Maximum …