The various topics investigated in the course of the preparation of this thesis can by unified under the common theme of fibrous fIltration enhancement from both experimental and theoretical perspectives. Fibrous filtration is by far the most common method of gas pUrification in use today and further improvements will require a better understanding of the various mechanisms contributing to the collection of particles. The lack of agreement between experimental results and the latest theoretical models found in the literature which have been put forward to predict fIlter efficiency led to the development of a complex computer simulation of a fIltration process. The model simultaneously accounts for particle collection in the inertial impaction, interception and Brownian diffusion regimes and also recognizes that real fIlters do not consist of a simple array of fibres, but are a complex mixture of fibres positioned randomly in space. Test fIlters carefully manufactured from well characterized glass fibre components were used to challenge monosize sodium chloride aerosols. Since most of the filtration parameters are known, our model was used and directly compared with the leading theoretical models and our experimental results. The enhancement of fibrous filters by gradual clogging was investigated. The filtration characteristics; pressure drop and upstream & downstream concentrations were monitored as loading progressed. A discussion of the changes in the quality factor which was found to be dependent upon aerosol size is given. The fractal dimension of the particle deposits on individual fibres was measured and found to be dependent on the fIltration dynamics present. The fundamental forces of electrostatic filtration (Coulomb, image and polarization forces) were clearly demonstrated in a system of test aerosols and fibrous fIlters which were identical except for the amount of charges the particles and fibres contained. The size ranges in which these forces are effective were accurately measured.

The development of the next generation of Saab's multirole combat aircraft the JAS 39 Gripen includes developing a lot of new software for the aircraft's on-board computers. The new software has to be loaded into these computers routinely, in order to carry out testing on it. This is currently a slow and tedious process. In order to load the computers a protocol defined in the ARINC 615A standard is used. Today Saab uses commercial software applications implementing this protocol for the loading process. These applications have significant disadvantages, such as not being able to load several computers in parallel or only being able to load computers from a specific manufacturer. In this thesis we introduce a system using a client-server architecture that allows users to load the computers in parallel, regardless of the manufacturer. In Section 3.2.2 we show that our system reduces the time required to load the aircraft's on-board computers significantly. We also indicate some improvements that can be made in order to speed up the process even further. These improvements mainly involve improving the on-board computers themselves through the use of faster persistent storage and support for later revisions of the protocol involved.

Master of Science / Department of Civil Engineering / Asadollah Esmaeily / The accuracy and applicability of the existing stress-strain models for concrete confined by Carbon Fiber Reinforced Polymer (CFRP) were analytically and experimentally explored. This investigation includes major parameters affecting the stress-strain response of confined concrete, including the loading pattern and protocol. It has been observed and reported that the experimentally recorded stress-strain relationship of the same specimen will be different if the loading protocol of the test is switched from displacement control to load control. In the experimental phase of this study, four standard 6" by 12" concrete cylinders were constructed using the same concrete batch for consistency. Three two-inch strain gauges were affixed equally spaced at mid-height on the surface of the specimen in the longitudinal direction, and two two-inch strain gauges were applied in the lateral direction at mid-height opposite each other. CFRP was then impregnated with a two-part epoxy and applied externally in two continuous layers, with an overlap. During the first phase of the experimental program, the tests were conducted with a constant load rate or with a constant displacement rate. The data was collected from externally mounted strain gauges and potentiometers positioned on the opposite sides of the cylinder in the longitudinal direction. Since the capacity of the existing actuator in the structural lab was less than the required failure level of the specimens, a nutcracker-like device was constructed to increase the mechanical advantage of the test frame in the second phase of the experimental program. In this phase, all tests were conducted in displacement control. Various models were selected to be studied from a large number of existing models that propose to determine the stress-strain relationship of concrete. Analytical predictions of the models were compared against the experimental data. Results show that some of the models provide a reasonable prediction of the real performance of the specimen. However, in general, predictions are different from the real performance for most models.

Philosophiae Doctor - PhD / The most significant human impacts on the hydrological system are due to land-use change. The conversion of land to agricultural, mining, industrial, or residential uses significantly alters the hydrological characteristics of the land surface and modifies pathways and rates of water flow. If this occurs over large or critical areas of a catchment, it can have significant short and long-term impacts, on the quality of water. While there are methods available to quantify the pollutants in surface water, methods of linking non-point source pollution to water quality at catchment scale are lacking. Therefore, the research presented in this thesis investigated modelling techniques to estimate the effect of land-cover type on water quality. The main goal of the study was to contribute towards improving the understanding of how different landcovers in an urbanizing catchment affect surface water quality. The aim of the research presented in this thesis was to explain how the quality of surface runoff varies on different land-cover types and to provide guidelines for minimizing water pollution that may be occurring in the Kuils-Eerste River catchment. The research objectives were; (1) to establish types and spatial distribution of land-cover types within the Kuils-Eerste River catchment, (2) to establish water quality characteristics of surface runoff from specific land-cover types at the experimental plot level, (3) to establish the contribution of each land-cover type to pollutant loads at the catchment scale. Land-cover characteristics and water quality were investigated using GIS and Remote Sensing tools. The application of these tools resulted in the development of a landcover map with 36 land classifications covering the whole catchment. Land-cover in the catchment is predominantly agricultural with vineyards and grassland covering the northern section of the catchment. Vineyards occupy over 35% of the total area followed by fynbos (indigenous vegetation) (12.5 %), open hard rock area (5.8 %), riparian forest (5.2 %), mountain forest (5 %), dense scrub (4.4 %), and improved grassland (3.6 %). The residential area covers about 14 %. Roads cover 3.4 % of the total area. Surface runoff is responsible for the transportation of large quantities of pollutants that affect the quality of water in the Kuils-Eerste River catchment. The different land-cover types and the distribution and concentration levels of the pollutants are not uniform. Experimental work was conducted at plot scale to understand whether landcover types differed in their contributions to the concentration of water quality attributes emerging from them. Four plots each with a length of 10 m to 12 m and 5 m width were set up. Plot I was set up on open grassland, Plot II represented the neyards, Plot III covered the mountain forests, and Plot IV represented the fynbos landcover. Soil samples analyzed from the experimental plots fell in the category of sandy soil (Sa) with the top layer of Plot IV (fynbos) having loamy sand (LmSa). The soil particle sizes range between fine sand (59.1 % and 78.9 %) to coarse sand (between 7 % and 22 %). The content of clay and silt was between 0.2 % and 2.4 %. Medium sand was between 10.7 % and 17.6 %. In terms of vertical distribution of the particle sizes, a general decrease with respect to the size of particles was noted from the top layer (15 cm) to the bottom layer (30 cm) for all categories of the particle sizes. There was variation in particle size with depth and location within the experimental plots. Two primary methods of collecting water samples were used; grab sampling and composite sampling. The quality of water as represented by the samples collected during storm events during the rainfall season of 2006 and 2007 was used to establish water quality characteristics for the different land-cover types. The concentration of total average suspended solids was highest in the following land-cover types, cemeteries (5.06 mg L-1), arterial roads/main roads (3.94 mg L-1), low density residential informal squatter camps (3.21 mg L-1) and medium density residential informal townships (3.21 mg L-1). Chloride concentrations were high on the following land-cover types, recreation grass/ golf course (2.61 mg L-1), open area/barren land (1.59 mg L- 1), and improved grassland/vegetation crop (1.57 mg L-1). The event mean concentration (EMC) values for NO3-N were high on commercial mercantile (6 mg L-1) and water channel (5 mg L-1). The total phosphorus concentration mean values recorded high values on improved grassland/vegetation crop (3.78 mg L-1), medium density residential informal townships (3mgL-1) and low density residential informal squatter camps (3 mg L-1). Surface runoff may also contribute soil particles into rivers during rainfall events, particularly from areas of disturbed soil, for example areas where market gardening is taking place. The study found that different land cover types contributed differently to nonpoint source pollution. GIS model was used to estimate the diffuse pollution of five pollutants (chloride, phosphorus, TSS, nitrogen and NO3-N) in response to land cover variation using water quality data. The GIS model linked land cover information to diffuse nutrient signatures in response to surface runoff using the Curve Number method and EMC data were developed. Two models (RINSPE and N-SPECT) were used to estimate nonpoint source pollution using various GIS databases. The outputs from the GIS-based model were compared with recommended water quality standards. It was found that the RINSPE model gave accurate results in cases where NPS pollution dominate the total pollutant inputs over a given land cover type. However, the N-SPECT model simulations were too uncertain in cases where there were large numbers of land cover types with diverse NPS pollution load. All land-cover types with concentration values above the recommended national water quality standard were considered as areas that needed measures to mitigate the adverse effects of nonpoint pollution. The expansion of urban areas and agricultural land has a direct effect on land cover types within the catchment. The land cover changes have adverse effect which has a potential to contribute to pollution.

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 vitro studies have shown that the major membrane phospholipid phosphatidylcholine (PC) can positively influence the incorporation of cholesterol in lipid membranes. The influence of PC on the cellular trafficking of LDL-derived free cholesterol was investigated. Sterol regulatory-defective (SRD)-4 cells are Chinese hamster ovary (CHO)-derived fibroblasts that display vastly elevated rates for the synthesis and catabolism of PC. SRD-4 cells harbor two known gene mutations: a mutation in the functional allele for SCAP, resulting in defective feedback suppression of cholesterol biosynthesis; and a loss-of-function mutation in the functional allele for acyl-CoA:cholesterol acyl transferase (ACAT), an endoplasmic reticulum (ER)-localized enzyme that esterifies free cholesterol. Incubation of SRD-4 cells with 50 µg/ml low density lipoprotein (LDL) for 18 h resulted in lysosomal accumulation of free cholesterol as revealed by filipin staining. This accumulation was not evident following LDL treatment of parental CHO7 cells, and was blunted in SRD-2 cells that express a constitutively-active form of SREBP-2 and overproduce cholesterol but have functional ACAT activity. Treatment of SRD-2 cells with LDL in the presence of an ACAT inhibitor 58-035 resulted in robust lysosomal cholesterol accumulation that was reversible upon drug washout, supporting that cholesterol trafficking in cholesterol-loaded cells is dependent on ACAT activity and, more specifically, ER free cholesterol levels. Lysosomal accumulation of LDL-derived cholesterol was prevented in SRD-4 cells supplemented with lyso-PC (50 µM), a substrate for PC synthesis through the reacylation pathway, and also in cells treated with bromoenol lactone (BEL), an inhibitor of phospholipase A2 implicated in bulk PC turnover. In a counter study, lysosomal LDL-derived cholesterol accumulation was induced in parental CHO-7 cells using R-propranolol, which inhibits the conversion of phosphatidic acid to diacylglycerol (DAG), a substrate in the CDP-choline pathway. This blockage was also relieved through co-treatment with lyso-PC. These studies support that PC to free cholesterol ratios in downstream organellar membranes can influence cholesterol trafficking out of lysosomal compartments in cholesterol-loaded cells.

Abstract Liquid containing tanks (LCTs) are used in water distribution systems and in the industry for storing water, toxic and flammable liquids and are expected to be functional after severe earthquakes. The failure of a large tank during seismic excitation has implications far beyond the economic value of the tanks and their contents. Then seismic design becomes a high necessity for this type of structure. However, tanks differ from buildings in two ways: first, during seismic excitation, the liquid inside the tank exerts a hydrodynamic force on tank walls, base, and roof in addition to the hydrostatic forces. Second, LCTs are generally required to remain watertight. Many current standards and guidelines such as ACI 350.3-06, ACI 371R-08, ASCE7, API650, EUROCODE8 and NZSEE 1986 code, cover seismic designs which are based primarily on theoretical analysis. This analysis is still not enough to fully describe the behavior of this structure under seismic oscillation noting that the theoretical analysis is based on a linear model and two dimensional spaces. So the focus of this study is to measure two important dynamic parameters which are the natural period and the maximum sloshing height of the water under harmonic motion by conducting an experimental investigation and computational fluid dynamic (CFD) simulation. Open-foam is the numerical tool chosen in this study. There is currently no study done with this tool to measure the behavior of the water inside a square tank neither under seismic motion nor harmonic oscillation.Finally, a comparison between the experimental, the analytical and the numerical results will be presented to confirm the level of validity of each method. Then a conclusion is made to summarize this research and to propose future works.

In this study, a three-dimensional two-phase (air and water) numerical solver is applied to investigate free surface flows. The first component aims to improve the overall understanding of the underlying physical mechanisms that occur during the interaction between turbulent hydraulic bores and simple structures. Data collected during large-scale physical experiments based on generating dam-break waves in a horizontal rectangular channel is used for comparing to the numerical results. An extensive sensitivity analysis on numerical parameters including spatial discretization and turbulence models is presented. Quantitative comparisons of numerical and experimental time series of water surface elevations, pressure, and net streamwise force exerted on the structure are used to validate the model. In the in-depth analysis, it is demonstrated that the model is able to simulate the pertinent aspects of the flow behaviour that occur during the interaction with good agreement. The numerical impulsive force generated at initial impact shows excellent agreement with the experimental results, particularly for the larger magnitudes bores considered. Since the numerical model treats the air as an incompressible media, the level of agreement observed between the experimental and numerical results suggests that the compressibility of the air in the leading edge of the bore during the physical testing had no significant effect on the measured impulsive force. The two-phase model was also able to capture the occurrence of a second transient spike in the force exerted on the structure when the initial runup collapsed back onto the incoming flow, trapping a pocket of air in the process. The model was further applied to investigate the effect of an initially quiescent layer of water in the downstream channel section on bore propagation characteristics and the subsequent interaction with the structure. It is demonstrated that for small nonzero values of initial downstream depth a substantial increase in bore depth occurs. However, further increases in the downstream depth did not appear have any significant effects. For the greatest downstream depth simulated, a considerable reduction in the hydrodynamic force is observed as a result of a more rapid closing of the wake that develops on the leeside of the structure. The second component of the study applies the same numerical solver to investigate a novel long wave generation technique for producing laboratory-scale tsunami waves. The concept is based on removing the air from the inside of a tank with a submerged outlet at the upstream end of the basin and releasing the water in a controlled manner. A similar procedure as described above was used to calibrate the numerical parameters to experimentally-measured wave heights and periods. To model the influence of the pneumatic valves mounted on top of the upstream chamber, time-varying pressure boundary conditions are developed to regulate and control the pressure inside the tank. Quantitative and qualitative comparisons of the numerical and experimental results show good agreement and a high potential for the solver to be used for similar investigations. An analysis is performed to improve the existing understanding of the wave formation process. The model is also applied to modify test configurations that influence the waveform for which the results may be used to aid in making operating decisions for future tests or in the design of similar wave generating devices.

The mitigation of blast hazards on critical reinforced concrete structures has become a major concern in regards to the safety of people and the integrity of buildings. Recent terrorist incidents and accidental explosions have demonstrated the need to study the effects of such threats on structures in order to develop effective methods of reducing the overall impact of blast loads. With the arrival of innovative materials such as steel fibre reinforced concrete (SFRC), ultra-high performance fibre reinforced concrete (UHPFRC) and high strength steel reinforcement, research is required in order to successfully adapt these new materials in blast-resistant structures. Hence, the objective of this thesis to conduct an experimental parametric study with the purpose of investigating the implementation of these innovative materials in reinforced concrete slabs and panels. As part of the study, a total of fourteen one-way slab specimens with different combinations of concrete, steel fibres and steel reinforcement are tested under simulated blast loads using the University of Ottawa Shock-Tube Facility. The test program includes three slabs constructed with normal-strength concrete, five slabs constructed with SFRC and six slabs constructed with UHPFRC. Among these specimens, four are reinforced with high-performance steel reinforcement. The specimens are subjected to repeated blast loading with gradually increasing reflected pressure and reflected impulse until failure. The performance of the slabs is studied using various criteria such as failure load and mode, maximum and residual deflections, as well as tensile cracking, spalling and secondary fragmentation control. The behaviour of all specimens is compared in different categories to determine the effects of concrete type, steel reinforcement type, steel fibre content and steel fibre type on blast performance. As part of the analytical study the response of the slab specimens is predicted using dynamic inelastic single-degree-of-freedom (SDOF) analysis. The dynamic analysis is conducted by generating load-deformation resistance functions for the slabs incorporating dynamic material properties.

Concussions are debilitating injuries affecting the short and long-term health of those who suffer from them. While an increased awareness of the injury has helped lead to a better understanding of the importance of better monitoring and treatment protocols, concussive injuries continue to occur at an alarming rate. Current injury risk thresholds exist and are used in the development of better equipment to protect athletes in high impact sports, however much of this data is based on simulations and/or cadaveric and animal model data from falls. Thus, there is a lack of data from concussive injuries resulting from a multitude of injury events within different sports, including collisions, falls and punches. The purpose of this thesis was to use dynamic response characteristics and brain tissue response to compare four different injury events from reconstructions of real life concussive injury events. This research was designed to provide information related to brain trauma characteristics specific to four common concussive brain injury events. Seventy-two (72) injury reconstructions were used in this study involving four injury events; collisions, helmeted falls, unhelmeted falls and punches. The results from the first study revealed that while all injury events produced similar MPS and Von Mises stress values, the injury events produced different peak linear and rotational accelerations. In terms of risk for concussive injury, differences were also found between percent risk for concussion and the specific injury events, questioning the validity of current concussive thresholds’ applicability to across all types of concussive injury events. The second study aimed to characterize each concussive injury event by means of specific kinematic characteristics unique to that particular event. The results showed that dynamic response variables that accounted for the most variance changed dependant on the concussive producing event. The third study compared maximal principle strain and strain fields within the brain by the specific injury event. The results showed that global strain within specific regions of the brain were significantly different between the different injury events. Furthermore, unique strain fields within the cerebrum were found between the four concussive injury events. The three studies in this research program characterize four common concussive injury events found in sport. It aimed to describe the unique dynamic response characteristics for each injury event that may have significant influence on protective equipment development and standards testing. Finally, though the aim of this study was not to correlate location of strains within the brain with onset of concussive symptoms and duration, this study demonstrated that the concussive producing event can have an effect on location of peak strain and strain field within regions of the cerebrum associated with concussive symptoms.