Reinforced Concrete (RC) bridge piers, RC columns along exterior of buildings or those located in parking garages are designed to support large compressive axial loads but are vulnerable to transverse out-of-plane loadings, such as those arising from impacts or explosions. To address a lack of understanding regarding blast and impact response of RC members and the need for retrofit techniques to address deficiencies in existing structures, a multi-disciplinary team including various institutes of the National Research Council and the University of Ottawa has initiated work towards developing a fibre reinforced polymer composite protection system for RC columns subjected to extreme shocks. This thesis will focus on the impact program of the aforementioned project. An extensive literature review was conducted to gain a better understanding of: impact loading and associated dynamic effects; experimental testing of RC members subjected to impact; experimental testing of axially loaded members; and retrofit methods for the protection of RC under impact loading. Five half-scale RC columns were constructed and tested using a drop-weight impact machine and two additional specimens were tested under static loading. Deflections, strain distributions within the columns, impact loads and reaction loads were measured during the testing of the built RC members. Comparisons of experimental datum were established between members with differing levels of axial load and between a retrofitted and a non-retrofitted member. Single-degree-of-freedom analysis was used to obtain the predicted response of certain columns under impact loading allowing for comparisons with experimental data.

In this thesis, dual-frequency optoelectronic oscillators (OEOs) and their applications to transverse load sensing are studied. Two configurations of dual-frequency OEOs are proposed and investigated. In the first configuration, a polarization-maintaining phase-shifted fiber Bragg grating (PM-PSFBG) is employed in the OEO loop to the generation of two oscillating frequencies. The beat between the two oscillating frequencies is a function of the load applied to the PM-PSFBG, which is used in transverse load sensing. To avoid the frequency measurement ambiguity, a second configuration is proposed by coupling a dual-wavelength fiber laser to the dual-frequency OEO. A single tone microwave signal with the frequency determined by the birefringence of the grating is generated in the OEO and is fed into the fiber ring laser to injection lock the dual wavelengths. The sensitivity and the resolution are measured to be 9.73 GHz/(N/mm) and 2.06×10-4 N/mm, respectively. The high stability of the single-tone microwave signal permits accurate measurement, while the frequency interrogation allows an ultra-high speed demodulation.

Load management is an essential and important factor for distributed simulations running on shared resources due to load imbalances that can caused considerable performance loss. High Level Architecture (HLA) -based simulation is a framework that works to facilitate the design and management of distributed simulations. HLA coordinates the interaction between simulation entities (federates). However, HLA-based simulation standards do not present the ability to manage resources or help detect load imbalances that could directly cause decrease of performance. Focusing on this constraint, a migration-aware dynamic balancing system has been designed for HLA simulations to offer an efficient load-balancing scheme that works in large-scale environments. This system presents some limitations on estimating costs and benefits, so we propose an enhancement to this existing load balancing system, which improves the accuracy of estimating the number of migrations for the next load redistribution. The proposed scheme detects the load imbalances by evaluating the recourses overhead. The scheme classifies the recourses based on the overhead as overloaded and underloaded, followed by matching the highest overloaded recourses with the lowest underloaded recourses. Furthermore, the proposed scheme aims to precisely estimate the number of migrations by evaluating and analyzing the recourses to obtain the best number of migrations. Therefore, certain migrations that do not contribute to an improvement in the simulation performance are avoided. This avoidance is based on comparing time delay and time gain. Moreover, to be considered for migration, the overall sum of the time gains should be larger than the overall sum of the time delays. The proposed scheme has shown an improvement on decreasing the execution time.

Photovoltaic (PV) solar panels and trackers represent one of the most common renewable energy technology which converts sunlight radiation into electrical energy. The solar trackers specifically are more complex structures because they involve mechanical devices, a supporting slender structure, and photovoltaic modules mounted and positioned on top of the supporting structure. Solar trackers are mounted on mobile supports or racks, in order to enable the rotation and tilt of the PV which thus maintains their optimum exposure to the incident sunlight. Solar trackers support structures should be designed for wind resistance during the operation and at stow position for its life span and this became a concern considering the new tendency of installing the solar trackers on the rooftop of low-rise or medium-rise buildings. The current research focused on performing site measurements of the wind-induced displacement for a dual-axis solar tracking system installed on the roof of the Mann Parking building of the University of Ottawa, for different azimuth, elevations. The supporting structure of the solar tracker was instrumented with 16 strain gauges and the strains developed in the metal truss members were measured during the months February 2015 and March 2015. The tracker was rotated and tilted at different angles through the duration of the experiment and the strains observed on each structural element were recorded. In order to estimate deflections of the supporting structure for wind speeds higher than the ones measured, a finite element (FE) model of the solar tracker was created and static analysis was performed for different inclinations using the SAP 2000 structural software. The experimental results were in agreement with the FE simulation results as the stresses obtained ranged between 1.02 × 107 Pa and 7.88 × 107 Pa. Lower attack angles between 45° and 60° were found to have significant effect on the elements of the solar tracker irrespective of the wind load magnitude. Operational attack angles between 65° and 75° were found to be safer positions as obtained displacements and stress analysis result showed that the supporting structure of the solar tracker was stable for wind speeds between 0 m/s and 33m/s in Ottawa region

To achieve a high level of reliability, efficiency, and robustness in electric systems, the concept of smart grid has been proposed. It is an update of the traditional electric grid designed to meet current and future customers' requirements. With the smart grid, demand management has been adopted in order to shape the load pattern of the consumers, maintain supply-demand balance, and reduce the total energy cost. In this thesis, we focus mainly on energy savings by critically investigating the problem of load management in the smart grid. We first propose a user aware demand management approach that manages residential loads while taking into consideration users' comfort. This latter is modeled in a simple yet effective way that considers waiting time, type of appliance, as well as a weight factor to prioritize comfort or savings. The proposed approach is based on game theory using a modified regret matching procedure. It provides users with high incentives to participate actively in load management and borrows advantages of both centralized and decentralized schemes. Then, we investigate the issue of fairness within demand response programs. The fair division of the system bill stemming from the use of shared microgrid resources with different costs is examined. The Shapley value provides one of the core solutions to fairness problems; however, it has been known to be computationally expensive for systems such as microgrids. Therefore, we incorporate an approximation of the Shapley value into a demand response algorithm to propose a fair billing mechanism based on the contribution of each user towards attaining the aggregated system cost. Finally, we study energy trading in the smart grid as an alternative way to reduce the load on the grid by efficiently using renewable energy resources. We propose a solution that takes into account the smart grid physical infrastructure, in addition to the distribution of its users. Different constraints stemming from the nature of the smart grid have been considered towards a realistic solution. We show through simulation results that all of the proposed schemes reduce the load on the grid, the energy bills, and the total system energy cost while maintaining the users' comfort as well as fairness.

Dans le football professionnel, les blessures ont une influence négative sur la performance, l'économie et la santé. Malgré un accent accru sur la prévention des blessures dans le football, il est préoccupant de constater que les blessures n'ont pas diminué au cours des 11 dernières saisons. En raison de l'impact significatif et négatif des blessures dans le football professionnel, il est primordial de veiller à ce que de tels accidents ne se produisent plus. Il est important de déterminer de nouvelles méthodes et procédés afin de détecter et d'empêcher les blessures chez les footballeurs professionnels. En outre, dans la littérature de la recherche scientifique, il y a des résultats contradictoires et des débats en ce qui concerne les facteurs de risque, les tests et les exercices de prévention pour les blessures sans contact dans le football professionnel. Les recherches scientifiques devraient être menées afin d'influencer les pratiques soit en validant soit en réfutant certains procédés et certaines procédures, cependant, il y a actuellement un fossé entre la science et la pratique (Bishop, 2008).Le but de cette thèse était de : (a) étudier des méthodes nouvelles et innovantes pour détecter et prévenir les blessures sans contact au plus haut niveau du football professionnel masculin et (b) (b) de réduire le fossé entre la science et la pratique. Les études de recherche spécifiques menées dans cette thèse étaient (1) les facteurs de risque, le dépistage et les stratégies de prévention pour les blessures sans contact dans le football professionnel: les perceptions et les pratiques actuelles de 44 équipes de première division. (2) les facteurs de risque, le dépistage et les stratégies de prévention pour les blessures de non-contact dans le football professionnel :Les facteurs de risque, les tests et les stratégies de prévention pour des blessures sans contact dans le football professionnel: une revue systématique, (3) un simple test isométrique des membres musculaires inférieurs chez les joueurs de football professionnels, (4) Effet d'un programme de prévention des blessures sur un taux de blessures dans une équipe professionnelle de football participant aux compétitions européennes. La présente thèse a réussi à réduire le fossé entre la science et la pratique en révélant le top 3 des perceptions et des pratiques des équipes de football de haut niveau concernant les facteurs de risque (blessure antérieure, fatigue, déséquilibre musculaire), essais (écran de mouvement fonctionnel, questionnaire, isocinétique) et des exercices de prévention (excentrique, équilibre / proprioception et ischio-jambiers excentrique). Une revue systématique de la littérature scientifique a fourni un niveau scientifique de preuve pour les 3 principaux facteurs de risque, tout à la fois un niveau scientifique de preuve et des recommandations globales graduées ont été fournies pour les 3 premiers tests et exercices de prévention. Un test simple et pratique pour évaluer la force isométrique des membres musculaires inférieurs a été vérifié et mis en œuvre avec succès dans le cadre du football professionnel. Le test s'est avéré être à la fois assez fiable et sensible pour déceler les changements de force survenant après un match de football. Enfin, un programme de prévention des blessures à haute conformité a été correctement et efficacement mis en œuvre dans une équipe de haut niveau prenant part aux compétitions européennes et les taux de blessures considérablement réduits, même lors d'une période comprenant des matchs rapprochés soit 2 matchs par semaine.La présente thèse peut aider à guider les praticiens à utiliser les meilleures pratiques factuelles actuelles. En outre, du point de vue de la recherche, les résultats fournissent aux chercheurs des pistes où concentrer les futures recherches sur la prévention des blessures dans le football professionnel. / In professional football, injuries have a negative influence on performance, economy and health. Despite an increased focus on prevention of injury in football, it is of concern that injuries have not reduced in this cohort over the past 11 seasons. Due to the significant and negative impact of injuries in professional football it is of interest to prevent such injuries from occurring. It is important to determine new methods and processes to detect and prevent injuries in professional footballers. Additionally, within the scientific research literature there are conflicting results and ongoing debates in regards to risk factors, testing and preventative exercises for non-contact injury in professional football. Scientific research should aim to influence practice by either validating or refuting certain processes and procedures, however, there is currently a gap between science and practice (Bishop, 2008). Purpose: The purpose of this thesis was to (a) investigate new and innovative methods to detect and prevent non-contact injuries at the highest level of professional male football and (b) (b) to reduce the gap between science and practice. Studies: The specific research studies conducted in this thesis were (1) Risk factors, testing and preventative strategies for non-contact injuries in professional football: Current perceptions and practices of teams from 44 premier leagues. (2) Risk factors, testing and preventative strategies for non-contact injuries in professional football: A systematic review, (3) Reliability and sensibility of a simple isometric posterior lower limb muscle test in professional soccer players, (4) Effect of an injury prevention program on injury rate in a professional football team participating in European competition. Conclusion: The present thesis successfully reduced the gap between science and practice by revealing the top 3 perceptions and practices of top-level football teams concerning risk factors (previous injury, fatigue, muscle imbalance), testing (functional movement screen, questionnaire, isokinetic) and preventative exercises (eccentric, balance/proprioception and hamstring eccentric). A systematic review of the research literature provided a scientific level of evidence for the top 3 risk factors, while both a scientific level of evidence and overall graded recommendation was provided for the top 3 tests and preventative exercises. A simple and practical test to assess the isometric force of the posterior lower limb muscles was verified and implemented successfully in the professional football setting. The test was found to be both reliable and sensitive enough to detect changes in force following a competitive soccer match. Finally, an injury prevention program with high compliance was successfully and effectively implemented in a top-level team competing in European competition and significantly reduced injury rates even when playing during a congested match period i.e. 2 matches per week. The present thesis can help to guide practitioners in using the current best evidence based practice. Additionally, from a research perspective, the findings provides researchers with avenues of where to concentrate future research concerning injury prevention in professional football.

The effect of configuration changes and add-on devices on the drag reduction of a tractor-trailer is studied through wind tunnel tests using two 1/12-scale models. The configuration changes involve ground clearance, tractor-trailer gap, roof angle and back inclination while add-on devices include flow deflectors, skirts and gap seals. Moving surface boundary layer control as a means of drag reduction is also attempted. Both drag and pressure data are obtained to help identify local contributions. Results suggest that an optimum combination of configuration parameters can reduce drag up to 17% while the add-on devices resulted in a further decrease by a modest amount. The results with moving surface boundary layer control proved to be inconclusive. / Applied Science, Faculty of / Mechanical Engineering, Department of / Graduate

As population increases, the number of water bodies meeting water quality standards tends to decrease. The 1972 Clean Water Act (CWA) addresses the issues of point and nonpoint source pollution by requiring states to compose lists of waters that do not meet water quality standards and develop Total Maximum Daily Loads (TMDL) for those waters. This requirement of the CWA remained inactive until EPA and states suffered lawsuits from environmental groups and concerned citizens. The result prompted a flurry to develop TMDLs in compliance with consent decrees. A variety of methods and models serve as tools to calculate existing loads, load reductions and allocations. The purpose of this study is threefold 1) to examine two methods of TMDL development, Flow Duration (FD) used in Kansas and Hydrologic Simulation Program-Fortran (HSPF) used in Virginia; 2) to compare results of both methods in the same watershed of Virginia; and, 3) to evaluate stakeholder involvement in the TMDL process. A variety of stakeholders such as agencies, towns and industry, agribusiness, and concerned citizen/environmentalists are faced with meeting TMDL reductions and allocations. It is important that the TMDL process and implications are understood by all stakeholders. / Master of Public and International Affairs

Pas de résumé / No abstract

Perceptual capacity and selection in attention have for long been an interest in cognitive science, with early theories of early selection to late selection. Hearing is an important subject to investigate when it comes to attention and early auditory processing can be investigated by using auditory steady state responses (ASSRs). Studies on ASSRs to irrelevant sounds have investigated the 40 Hz ASSR and concluded no effect of load. As studies on temporal activation of ASSRs indicate that lower and higher frequencies activate different stages of the auditory pathway, there is a need to investigate other frequencies than the 40 Hz. This study investigated the 20 Hz and 80 Hz amplitude modulations using EEG. The visual stimuli were a rapid stream of letters and varied between no load, low load, and high load. The auditory stimuli were an amplitude-modulated tone with a carrier frequency of 500 Hz, with three varying modulation frequencies: 20 Hz, 40 Hz, and 80 Hz. Load level and amplitude modulation alternated over 18 blocks. The statistical analysis was comprised of t tests and Bayes Factor. Results provided support for the null hypothesis for the 20 Hz frequency but were inconclusive for the 40 Hz and 80 Hz frequency. More data is needed to give a conclusion for effect of load for the 40 Hz and 80 Hz frequency. As we did not have enough data, we cannot say anything about the temporal activation of ASSRs in the brain.