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The giant protein titin is the third myofilament in the cardiac sarcomere. It is responsible for generating passive forces in stretched myocardium and maintaining sarcomere structure. The force generation properties of titin are determined by titin's elastic springlike elements, and this dissertation focuses on the determination of the physical properties of these springlike elements using atomic force microscopy. The primary project of this dissertation investigates the link between a single point mutation in one of titin's subdomains and arrhythmogenic cardiomyopathy.

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Grip kinetics are emerging as an important measure in clinical assessments of handwriting pathologies and fine motor rehabilitation as well as in biometric and forensic applications. The signature verification literature in particular has extensively examined the spatiotemporal, kinematic, and axial pressure characteristics of handwriting, but has minimally considered grip kinetics. Therefore, the focus of this thesis was to investigate the variability of grip kinetics in adults during signature writing. To address this goal, a database of authentic and well-practiced bogus signatures were collected with an instrumented pen that recorded the forces applied to its barrel. Four different analytical studies were conceived. The first study investigated the intra- and inter-participant variability of grip kinetic topography on the pen barrel based on authentic signatures written over 10 days. The main findings were that participants possessed unique grip force topographies even when the same grasp pattern was employed and that participants could be discriminated from each other with an average error rate of 1.2% on the basis of their grip force topographies. The second study examined the stability of different grip kinetic features over an extended period of a few months. The analyses revealed that intra-participant variation was generally much smaller than inter-participant variations even in the long term. In the third study, grip kinetics associated with authentic and well-practiced bogus signatures were compared. Differences in grip kinetic features between authentic and bogus signatures were only observed in a few participants. The kinetics of bogus signatures were not necessarily more variable. The variation of grip kinetic profiles between participants writing the same bogus signature was evaluated in the fourth study and an average error rate of 5.8% was achieved when verifying signatures with kinetic profile-based features. Collectively, the findings of this thesis serve to inform future applications of grip kinetic measures in biometric, clinical and industrial applications.

Grip kinetics are emerging as an important measure in clinical assessments of handwriting pathologies and fine motor rehabilitation as well as in biometric and forensic applications. The signature verification literature in particular has extensively examined the spatiotemporal, kinematic, and axial pressure characteristics of handwriting, but has minimally considered grip kinetics. Therefore, the focus of this thesis was to investigate the variability of grip kinetics in adults during signature writing. To address this goal, a database of authentic and well-practiced bogus signatures were collected with an instrumented pen that recorded the forces applied to its barrel. Four different analytical studies were conceived. The first study investigated the intra- and inter-participant variability of grip kinetic topography on the pen barrel based on authentic signatures written over 10 days. The main findings were that participants possessed unique grip force topographies even when the same grasp pattern was employed and that participants could be discriminated from each other with an average error rate of 1.2% on the basis of their grip force topographies. The second study examined the stability of different grip kinetic features over an extended period of a few months. The analyses revealed that intra-participant variation was generally much smaller than inter-participant variations even in the long term. In the third study, grip kinetics associated with authentic and well-practiced bogus signatures were compared. Differences in grip kinetic features between authentic and bogus signatures were only observed in a few participants. The kinetics of bogus signatures were not necessarily more variable. The variation of grip kinetic profiles between participants writing the same bogus signature was evaluated in the fourth study and an average error rate of 5.8% was achieved when verifying signatures with kinetic profile-based features. Collectively, the findings of this thesis serve to inform future applications of grip kinetic measures in biometric, clinical and industrial applications.

Nitrogen compounds, such as aqueous ammonia, are a widespread problem in the wastewater industry as they are toxic to numerous aquatic life, cause eutrophication, and contribute to various environmental concerns. Environment Canada has mandated new wastewater regulations, limiting un-ionized ammonia discharge to 1.25 mg/L, expressed as nitrogen. This study provides insight into methods for removing nitrogen compounds, specifically aqueous ammonia, from wastewater. Two wastewater treatment technologies were compared: Ultra Violet light and an electrochemical process. These treatments were evaluated individually, as well as in combination, to determine potential synergistic effects.

This thesis investigated corrosion of a reinforcing steel bar embedded in concrete and the effect of corrosion coupling on the bar/concrete interface induced by the variation of corrosion potentials with concrete depth. Two separate numerical models were used to simulate the corrosion process which included: a two-dimensional finite element model for mass transport of oxygen and chloride to the bar/concrete interface; and, a one-dimensional model for the corrosion current flow through the electrolyte induced by corrosion potential differences on the bar/concrete interface. A novel approach to corrosion modeling in reinforced concrete that had not been identified in the literature was used. This new approach, incorporated: variable solution conductivity developed from concentrations within the pore solution; anodic and cathodic areas modified to maximize corrosion current through the electrolyte; and, kinetics of corrosion set by the pore solution chemistry. Various reinforcing configurations and moisture conditions were evaluated within the simulation to obtain insight into the effect these variables have on corrosion potentials measured on the concrete surface and the corresponding corrosion currents generated on the bar/concrete interface. Variables related to bar diameter, concrete cover, and bar spacing where all shown to affect corrosion potentials and current densities on the bar/concrete interface and the concrete surface where field measurements are obtained. Moisture conditions were found to have the largest impact on corrosion potentials and current density’s on the bar/concrete interface. When relative humidity’s of 90% or higher were used, simulated corrosion potentials on the concrete surface under high chloride conditions were found to reach values identified in ASTM C876 and Alberta Transportations Deck Testing Guidelines that indicate active corrosion. However, when moisture conditions were reduced to below 90% relative humidity, simulated corrosion potentials on the concrete surface for high chloride concentrations did not achieve values that indicate a high probability of corrosion. This result suggests a secondary mechanism must be present on the bar/concrete interface that changes the chemical composition within the pore solution to shift the kinetics of corrosion to an environment that will produce the negative corrosion potentials recognized as indicating a high probability of corrosion. Therefore, a new mechanism is proposed that outlines the process necessary for the pore solution on the bar/concrete interface to transition the kinetics of corrosion to an actively corroding state at low relative humidity. This mechanism requires local acidification of the pore solution along portions of the bar where anodic processes are increased due to the presence of chloride and reduced oxygen availability. Reaching this environment requires free OH- to be consumed without replenishment from the surrounding environment by either diffusion from high pH areas or dissolution of the hardened portions of the pore structure. The proposed mechanism begins with corrosion by-products formed when Fe2+ reacts with free OH-, precipitates from the pore solution onto the pore structure as Fe(OH)2. Once precipitated, the contact area between pore solution and hardened portions of the pore structure are reduced which restricts the dissolution process for restoring OH- removed from the electrolyte. Additionally, precipitation of Fe(OH)2 reduces the flow of OH- from the surrounding high pH zones as the pore structure is restricted. Both mechanisms result in a pH gradient being formed with acidified zones created on the bar/concrete interface in the anodic regions. These acidified zones cause the kinetics of corrosion to transition from a passivated state, towards an environment similar to carbonation.

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