Theses

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  • The effect of copper and manganese on phytoplankton in the Grand River (southern Ontario), Lake Erie and Pacific Ocean ecosystems
    The effect of copper and manganese on phytoplankton in the Grand River (southern Ontario), Lake Erie and Pacific Ocean ecosystems
    With the increased use and loading of metals into the environment, the accumulation of toxic metals by phytoplankton has become a concern. Trace metal interactions with phytoplankton are of particular interest due to the influence of phytoplankton on the biogeochemical cycling of metals in aquatic systems. The study of the accumulation of metals and their toxicity in phytoplantkon is also of interest since phytoplankton lie at the base of many aquatic food webs. Toxic metals therefore have the potential to disrupt food webs and may have important implications onaquatic ecosystems.This study has chosen to focus on the response of phytoplankton to two tracemetals in particular: copper (Cu) and manganese (Mn). Although both Cu and Mn are essential elements for phytoplankton, Cu is of particular interest as a toxicant. Anumber of laboratory studies have suggested that there exists a physiologicalinteraction between Cu and Mn, and that Cu toxicity can be decreased in the presenceof high concentrations of Mn. However, few studies have examined the effects ofthese metals on phytoplankton in their natural environments. The significance of thisstudy is that it is one of the first to examine whether the importance of Cu toxicity andthe interaction between Cu and Mn observed in the laboratory is also observable undernatural conditions.Short-term bioassays were conducted in order to observe the response of phytoplankton from the Grand River (Southern Ontario) and Lake Erie to additions of various concentrations of eu and Mn under natural conditions. Similar long-term bioassay experiments were also conducted in the Pacific Ocean. Experiments in the Grand River and the Pacific Ocean revealed no significant decrease in phytoplankton biomass or in photosynthetic efficiency with the addition of various concentrations of Cu and Mn. In Lake Erie, phytoplankton biomass was only adversely affected following relatively high additions of Cu of 60 nM, and only under certain conditions. These results seem to indicate that under the tested conditions, Cu toxicity may not be of particular concern to the phytoplankton of the Grand River, Lake Erie and Pacific Ocean ecosystems.
    The effect of corrosion on shear behaviour of self-consolidating concrete beams
    The effect of corrosion on shear behaviour of self-consolidating concrete beams
    The objectives of this research are to compare the effect of corrosion on shear behavior in particular, and the overall structural response in both NC and SCC beams in general. Twenty reinforced concrete beams were used, with ten specimens cast using normal concrete (NC), and the other ten were cast using self-consolidating concrete (SCC). The dimensions for each beam were 150mm x 220mm x 1400mm. Using accelerated corrosion through the application of a constant current of one ampere, four stages of corrosion were established at 5%, 10%, and 20% of mass loss. Simply supported beams were loaded with two concentrated loads, and a four-point loading test was applied to the reinforced concrete (RC) beams. If (a) is the distance from the concentrated load to the reaction, and (d) is the distance from the center of the tensile flexural rebars to the top of the concrete beam, then a/d=2.5 was applied to assure the highest probability of shear failure mode. The data collected from load cell, LVDTs, corrosion crack patterns and loading cracks patterns were used to study the effects of multiple stages of corrosion on the shear behaviour of reinforced NC and SCC concrete beams. The corroded rebars were then retrieved and cleaned to compare the calculated mass loss with real mass loss. The results showed high correlation between the calculated mass loss (according to Faraday law) and real mass loss. The accelerated corrosion resulted in a corrosion crack pattern, which was documented and analyzed. In this research, the use of NC and SCC showed minor influences on failure mode, while the different states of corrosion showed a higher degree of influence on failure mode and the structural capacity of beams made from both types of concrete. The apparent changes in failure mode were associated with the increased corrosion stage.
    The effect of different mix proportions on the hygrothermal performance of hempcrete in the Canadian context
    The effect of different mix proportions on the hygrothermal performance of hempcrete in the Canadian context
    Hempcrete is a light composite bio-based envelope plus insulation material with lime as binding agent and hemp as a renewable raw material from agriculture. The main qualities of hempcrete are hygrothermal behavior and low environmental impact. There is currently lack of clear cross-industry standards for hempcrete; however, extensive research, laboratory experiments and literature reviews are ongoing. The primary aim of this study was to understand the impact of different mixes on the performance of hempcrete and to establish hygrothermal behavior of a hempcrete wall in the Canadian context (by measuring dry density and some other hygroscopic parameters for 3 different mixes) as well as to define the required minimum thickness for a code compliant wall (as per OBC requirements) based on the most reliable reference R values. Based on the material values acquired from the tests and references, simulations for 2 types of wall assemblies and series of sensitivity analysis were carried out in WUFI software. Finally, further research on hygrothermal performance of hempcrete wall (using Canada grown hemp) was recommended to carry out by measuring thermal conductivity in various mean temperatures.
    The effect of face-to-face communication on editorial stance:  a case study of the 2010 Liberal Express tour
    The effect of face-to-face communication on editorial stance: a case study of the 2010 Liberal Express tour
    This Major Research Paper explores the value of face-to-face communication in a digital age by examining the effect of face-to-face communication on media coverage. The author outlines the theoretical components of agenda-setting theory, presentation theory, and invitational rhetoric to illustrate the process by which individuals or groups compete to gain attention and power, and the role that face-to-face communication can play to persuade. This theory is examined with a political case study of the Liberal Party of Canada’s cross-Canada bus tour in July and August of 2010. The author provides a discourse analysis of newspaper editorials published in Ontario, Canada before and after then-Party Leader Michael Ignatieff visited. The author observes that the tone of media coverage is more favourable after face-to-face communication with citizens and journalists took place, suggesting that face-to-face communication is an effective tool for politicians in a digital age.
    The effect of heat-treating temperatures on induced compressive residual stress and fatigue life in 300m landing gear steel due to shot peening
    The effect of heat-treating temperatures on induced compressive residual stress and fatigue life in 300m landing gear steel due to shot peening
    The main objective of the study is to model the behavior of residual stresses in shot peened 300M landing gear steel affected by heat treatment. It is well known that residual stresses can have a significant influence on the mechanical behavior of major components under stresses. Therefore, information regarding the stability of existing residual stress states is of significant importance. In this experiment, special attention is paid to consequences of the heat treatment processes on compressive residual stresses induced in material by shot peening. The relaxation in residual stress due to addition of thermal energy by heat treatment at different temperatures and times is investigated. An existing model was used to create a stress relaxation equation for 300M high strength steels. Effect of heat treatment on residual stress distribution at subsurface level is also be examined. The current study will focus on the initial compressive residual stress field produced by common aerospace peening conditions and by how much isothermal exposures alter this stress and factors affecting the stress relaxation as well as fatigue life of the affected components.
    The effect of learning, forgetting,  fatigue, and recovery on the performance of dual-resource constrained (DRC) systems
    The effect of learning, forgetting, fatigue, and recovery on the performance of dual-resource constrained (DRC) systems
    Dual-Resource Constrained (DRC) systems consist of two resources: workers and machines (stations). DRCs have become common in manufacturing and service firms that emphasise flexibility, where workers perform different tasks. Although having a flexible workforce is beneficial, it comes at a cost. When workers alternate between different jobs the productivity of the system is affected. On one hand the system becomes more responsive to changes (internal/external), and on the other hand worker productivity and system throughput deteriorate because of the loss of knowledge and workers’ fatigue. This subjects workers to conflicting phenomena. When workers are performing a task they are learning but also accumulating fatigue, which may result in error or injury. When transferred to another task, or on a break, workers may forget what they have learnt but at the same time recover from fatigue, either fully or partially. In particular, forgetting and fatigue are interesting to be considered as they directly affect the quality of products. This research investigates the effects of workers’ learning-forgetting and fatigue-recovery on DRC systems. First, it modifies a known learning-forgetting model by accounting for fatigue and recovery. Second, it assumes that the quality of a production process may deteriorate and generate defective items that require rework. Third, a human error model is developed that considers human learning-forgetting and fatigue-recovery in producing defective items. Fourth, a comprehensive model is developed that integrates learning, forgetting, fatigue, and recovery into a DRC system with quality consideration. This model is investigated for different transfer and flexibility policies. Numerical results provide insights and guidelines that may help operations managers with decisions on how to improve a system’s performance and throughput, while considering worker welfare. Results indicate that it is important to consider workers capabilities and limitations when designing manufacturing systems. They also suggest that ignoring human restrictions and abilities results in unrealistic production planning and erroneous cost estimation.
    The effect of multi-bit correlation on the design of routing resources in field programmable gate arrays
    The effect of multi-bit correlation on the design of routing resources in field programmable gate arrays
    The large arithmetic-intensive applications increasingly implemented on field-programmable gate arrays (FPGAs) challenge FPGA architects to design FPGAs that can efficiently transport large amount of multi-bit wide signals in the data-path circuits of these applications. In this work, we investigate the area efficiency of two FPGA multi-bit aware routing architectures - the sparse and the enhanced sparse architectures, and compare them with the conventional and the configuration memory sharing architectures. We found that the sparse and enhanced sparse architectures are 6-10% more efficient than the conventional architecture. Our data also show that while the configuration memory sharing architecture can achieve the highest level of theoretical area savings for multi-bit transportation, it performs poorly for circuits with 50% or less multi-bit signals. These results suggest that FPGA architects should look beyond conventional architectures in order to create more efficient routing architectures for modern FPGAs.
    The effect of temperature on fatigue strength and damage of FRP composite laminates
    The effect of temperature on fatigue strength and damage of FRP composite laminates
    The present study intends to investigate the effect of temperature on cumulative fatigue damage of laminated fibre-reinforced polymer (FRP) composites. The effect of temperature on fatigue damage is formulated based on a previously proposed residual stiffness fatigue damage model. The fatigue strength of FRP composite laminates is also formulated to have temperature dependent parameters. The research work is divided into three main parts; the first part reviews the fatigue damage mechanism is fibre-reinforced composites based on stiffness degradation. The recent residual stiffness of Varvani-Shirazi was used as the backbone structure of damage analysis in this thesis. This model is capable of damage assessment while the effects of maximum stress, stress ratio and fibre orientation of FRP composites were recognized. The Varvani-Shirazi damage model was further developed to assess fatigue damage of FRP composites at various temperatures (T). Inputs of the damage model are temperature dependent parameters including Young's modulus (E), ultimate tensile strength(ðult) and fatigue life (Nf). As the next part of the proposed analysis, the temperature dependency of each parameter is formulated, and the relations of E-T and ðult-T are substituted in the Varvani-Shirazi fatigue model. Finally, all terms and equations are evaluated with the experimental data available in the literature. Six sets fatigue data were used in this thesis to evaluate fatigue of FRP specimens. The predicted results were found to be in good agreement with the experimentally obtained data. The proposed fatigue damage model was found promising to predict the fatigue damage of unidirectional (UD) and women FRP composites at different temperatures. Temperature dependant parameters of Young's modulus, ultimate tensile strength, and S-N diagram were also found to be responsive when used of UD, cross-ply, and quasi-isotropic FRP laminates.
    The effect of traffic strategies on emissions
    The effect of traffic strategies on emissions
    Air pollution and its relationship to the ecosystem and human life has always been the subject of a significant amount of study. The effect of highway air emissions on urban air quality has been studied for many years. This report contains a simulation of a single intersection in an urban area, using Arena®, a general purpose simulation program, and taking into account dynamic and stochastic considerations. The United States Environmental Protection Agency (USEPA) emission factors for idling situations were used to measure the emission of carbon monoxide (CO), volatile organic compounds (VOC) and nitrogen oxide (Nox) for the delay time. The simulation result predicts emission levels to be higher in a two-phase plan (unprotected left lane) with three different cycle times studied in this case (90, 120, and 140 seconds) compared to a three-phase plan (a protected left lane). However, the degree to which a two-phase plan is positively correlated with intersection cycle time suggests that a multi-faceted approach needs be taken in implementing modifications to reduce overall emissions.
    The effectiveness of Tillage Radish® to improve the growing medium for trees
    The effectiveness of Tillage Radish® to improve the growing medium for trees
    Urban trees provide ecosystem services, the value of which is dependent on canopy coverage. However, canopy growth is often restricted by soil compaction. Compaction reduces plant access to important soil resources and mechanically impedes root growth. Bio-drilling plants offer an alternative approach to conventional remediation methods. The study evaluated the effectiveness of growing Tillage Radish® to remediate soil compaction and improve soil quality under established trees. The study plot was located in Guelph, Ontario. Soil data was collected before and after planting radish. Results indicated that 1) radish growth was limited by nutrients but not soil compaction. And, 2) Tillage Radish® reduced surface compaction in moderately to highly compact soils. Other soil characteristics did not change significantly. The results suggested that planting Tillage Radish® has potential to remediate compaction in the rooting zone of trees. However, fertilization may be necessary to maximize radish growth and its associated soil remediation benefits., Dr. Andrew A. Millward is named as co-author on page iii.
    The effects of ISO 14001 on corporate financial and environmental performance
    The effects of ISO 14001 on corporate financial and environmental performance
    The purpose of this study is to examine the effects of ISO 14001 registration on corporate financial and environmental performance. The stock market's reaction to the ISO 14001 registration of a sample of Canadian firms is investigated. An analysis of the overall sample of companies revealed that there were no abnormal stock market returns experienced during a three day event window. However, abnormal returns were experienced when the companies were analyzed individually. The environmental performance component of this study investigated whether ISO 14001 registered facilities experience greater emission reductions than non-registered facilties within the Transportation Equipment Industries sector in Canada. The results of the analysis indicated that there was no difference between facilities that adopted ISO 14001 at differenct time periods and that the facilities that adopted ISO 14001 experienced an increase in aggregated weighed emissions.
    The effects of corrosion on the performance of reinforced concrete beams
    The effects of corrosion on the performance of reinforced concrete beams
    This report presents the results of a laboratory investigation into the effects of corrosion on the structural behaviour of reinforced concrete (RC beams. Twelve RC beams (156 x 176 x 1150 nun) were constructed, ten of which were corroded to various levels by impressed current while the remaining two were set aside as the control beams. Each beam was tested using non-destructive methods and then by four-point loading and the corresponding loads and deflections were recorded Following the mechanical testing, the tensile steel -was retrieved and cleaned in order to assess the mass loss. The results of this experiment clearly indicated a dramatic shift in the nature of the failure of corroded RC beams. Specifically, it was observed in the present study that as corrosion increased the failure mode of the beams shifted from predictable ductile flexure failures at mid-span, to more brittle failures near the support. Based on the data collected, several new corrosion-dependant empirical relationships were established to model the altered responses of RC beams (ie. stiffness, deflection ratio, ductility, and toughness). In addition to beam tests, a pullout study -was conducted in an effort to identify the relationship between the reduction of load-carrying capacity and the residual bond strength of the tensile steel Other behavioural changes examined are initial cracking load, flexural crack development and the evolution of the failure mode. It was found that the overall behaviour of the beam specimens tested conforms to that reported in the literature, with reductions in the ultimate capacity, deflection capacity and stiffness upon increasing corrosion. Also, the results of this experiment clearly indicated a dramatic shift in the nature of the failure of corroded RC beams. Specifically, it was observed that as corrosion increased, the failure mode of the beams shifted from predictable ductile flexure failures at mid-span, to more brittle failures near the support.