This dissertation presents an investigation into the structure of macromolecular protein assemblies by mass spectrometry. The experiments described within are designed to systematically assess the analytical utility of surface-induced dissociation (SID) tandem mass spectrometry in the characterization of multi-subunit protein complexes. This is accomplished by studying the effects of ion-surface collision on the fragmentation products of protein assemblies that vary by mass, number of subunits, and protein structural features. The dissociation energetics and mechanisms of protein complexes are considered by examining the influence of ion internal energy and sub-oligomeric protein structure on the dissociation process. Conditions are first established for the preservation of “native” protein quaternary structure and applied to previously characterized systems for proof-ofconcept. These conditions are subsequently extended to determine the molecular weight and subunit stoichiometry of several small heat shock proteins. Native mass spectrometry is then combined with limited proteolysis experiments to characterize the subunit interface of a unique small heat shock protein, Hsp18.5 from Arabidopsis thaliana, identifying regions of the protein essential for preservation of the native dimer. The dissociation of non-covalent protein assemblies is then explored on a quadrupole time-of-flight (Q-TOF) mass spectrometer, modified for the study of ion-surface collisions. This instrument allows ions to be dissociated through collisions with a surface or more conventional collisions with gas atoms. The dissociation of protein complexes is explored by both activation methods beginning with specific and non-specific dimers with masses less than 40 kDa. These studies are extended to larger assemblies with as many as 14 subunits weighing over 800 kDa, and are applied to both homo- and hetero-oligomeric protein complexes. Activation of a protein complex with “n” subunits through multiple collisions with inert gas atoms results in asymmetric dissociation into a highly charged monomer and complementary (n-1)-mer regardless of protein size or subunit architecture. This process is known to occur through an unfolding of the ejected subunit, and limits the amount of structural insight that can be gleaned from such studies. Collision at a surface however, results in more charge and mass symmetric fragmentation, and in some instances reflects the substructure of the protein assembly under investigation. The differences observed between the CID and SID of protein complexes is attributed to the rapid deposition of large amounts of internal energy deposited upon collision at a more massive target such as a surface. The ion activation time-frame and energy transfer efficiency are proposed to induce dissociation on a time-scale that precedes subunit unfolding providing access to dissociation pathways that are inaccessible by traditional means of activation. The systems studied here represent the largest ions fragmented via surface collisions within a mass spectrometer, and the fragmentation products observed by SID demonstrate its promise for expanding the role of mass spectrometry in the field of structural biology.

Intelligent systems with even the bare minimum of sophistication require extensive computational power and complex processing units. At the same time, small insects like flies are adept at visual navigation, target pursuit, motionless hovering flight, and obstacle avoidance. Thus, biology provides engineers with an unconventional approach to solve complicated engineering design problems. Computational models of the neuronal architecture of the insect brain can provide algorithms for the development of software and hardware to accomplish sophisticated visual navigation tasks. In this research, we investigate biologically-inspired collision avoidance models primarily based on visual motion. We first present a comparative analysis of two leading collision avoidance models hypothesized in the insect brain. The models are simulated and mathematically analyzed for collision and non-collision scenarios. Based on this analysis it is proposed that along with the motion information, an estimate of distance from the obstacle is also required to reliably avoid collisions. We present models with tracking capability as solutions to this problem and show that tracking indirectly computes a measure of distance. We present a camera-based implementation of the collision avoidance models with tracking. The camera-based system was tested for collision and non-collision scenarios to verify our simulation claims that tracking improves collision avoidance. Next, we present a direct approach to estimate the distance from an obstacle by utilizing non-directional speed. We describe two simplified non-directional speed estimation models: the non-directional multiplication (ND-M) sensor, and the non-directional summation (ND-S) sensor. We also analyze the mathematical basis of their speed sensitivity. An analog VLSI chip was designed and fabricated to implement these models in silicon. The chip was fabricated in a 0.18 um process and its characterization results are reported here. As future work, the tracking algorithm and the collision avoidance models may be implemented as a sensor chip and used for autonomous navigation by intelligent systems.

Research presented in this dissertation falls into two parts: fragmentation mechanisms of peptide and fragmentation mechanism of amino acid derivatives. The study of peptide fragmentation may help to improve protein identification by incorporating the rules governing this process into search algorithms. This study elucidates the chemical 'rules' governing peptide dissociation. It is believed that these 'rules' can be incorporated into searching algorithms to achieve better protein identification. The present study focuses on the effects of different amino acids on fragmentation. Amino acids with a wide range of different chemical and physical properties are investigated, including amino acids with hydrophilic side chains, amino acids with aliphatic side chains and amino acids without side chains. It can be concluded from the present studies that the different amino acid properties have great influence on the peptide fragmentation and spectrum appearance.The study of fragmentation mechanisms of amino acid derivatives is another focus of this dissertation. Based on the fragmentation mechanism study, a quantification method was developed. The method can distinguish glutamine with 15N-label at N-terminal amine vs the side chain even if they have same molecular weight. Ammonia metabolism was successfully monitored by feeding mosquitoes with isotope-labeled compounds and subsequently measuring the amount of the labeled amino acids. This method demonstrates the power of mass spectrometry in metabolism studies.

Inspiration from biological systems suggests that robots should demonstrate same level of capabilities that are embedded in biological systems in performing safe and successful interaction with the humans. The major challenge in physical human robot interaction tasks in anthropic environment is the safe sharing of robot work space such that robot will not cause harm or injury to the human under any operating condition. Embedding human like adaptable compliance characteristics into robot manipulators can provide safe physical human robot interaction in constrained motion tasks. In robotics, this property can be achieved by using active, passive and semi active compliant actuation devices. Traditional methods of active and passive compliance lead to complex control systems and complex mechanical design. In this thesis we present compliant robot manipulator system with semi active compliant device having magneto rheological fluid based actuation mechanism. Human like adaptable compliance is achieved by controlling the properties of the magneto rheological fluid inside joint actuator. This method offers high operational accuracy, intrinsic safety and high absorption to impacts. Safety is assured by mechanism design rather than by conventional approach based on advance control. Control schemes for implementing adaptable compliance are implemented in parallel with the robot motion control that brings much simple interaction control strategy compared to other methods. Here we address two main issues: human robot collision safety and robot motion performance.We present existing human robot collision safety standards and evaluate the proposed actuation mechanism on the basis of static and dynamic collision tests. Static collision safety analysis is based on Yamada’s safety criterion and the adaptable compliance control scheme keeps the robot in the safe region of operation. For the dynamic collision safety analysis, Yamada’s impact force criterion and head injury criterion are employed. Experimental results validate the effectiveness of our solution. In addition, the results with head injury criterion showed the need to investigate human bio-mechanics in more details in order to acquire adequate knowledge for estimating the injury severity index for robots interacting with humans. We analyzed the robot motion performance in several physical human robot interaction tasks. Three interaction scenarios are studied to simulate human robot physical contact in direct and inadvertent contact situations. Respective control disciplines for the joint actuators are designed and implemented with much simplified adaptable compliance control scheme. The series of experimental tests in direct and inadvertent contact situations validate our solution of implementing human like adaptable compliance during robot motion and prove the safe interaction with humans in anthropic domains.

Water utilities in Nova Scotia face numerous challenges treating low turbidity water and complying with stringent guidelines and treatment standards. Problems associated with the treatment of low-turbidity water are not confined to Nova Scotia; several other provinces, British Columbia, Manitoba and Ontario share similar water characteristics of drinking water sources. The treatment of low turbidity water is a challenge for these utilities as it requires maintaining the appropriate coagulant dosage that will ensure adequate particle and natural organic matter removal, while at the same time not enhancing the formation of disinfection by-products. Another concern associated with the treatment of such water is that when the particle content of the water is very low, charge neutralization will not be effective due to the weak contact between destabilized particles. Currently, nanoparticles are not regulated as water contaminants, and thus it is unclear whether the existing filtration treatment practices are capable of removing them from drinking water. Obtaining in-depth information on nanoparticle characteristics in drinking water sources will provide a valuable resource that can assist in the development of future treatment strategies. In this research, characteristics of four synthetic nanoparticles cerium dioxide (CeO2), ferric oxide (Fe2O3), silicon dioxide (SiO2) and titanium dioxide (TiO2) were investigated in Milli-Q water for particle size, surface area, and surface potential using different characterization techniques. Water samples from Pockwock Lake were also characterized for naturally occurring nanoparticles. After initial testing, titanium dioxide (TiO2) nanoparticles were selected to examine particle removal at bench-scale filtration experiments, under operating conditions similar to those practiced at the J.D. Kline Water Supply Plant, Halifax, NS, Canada. Filter performance for the deposition of TiO2 nanoparticles was evaluated through the calculation of its attachment efficiency and coefficient under various water chemistry conditions. The calculated filter efficiency was then applied to simulate natural nanoparticles removal from water. The results of the research indicate that the investigated nanoparticles behaved similar to natural particles and formed aggregates with larger particle sizes in Milli-Q water. Among the tested nanoparticles, only titanium dioxide could be coagulated with alum, as its negative surface charge and zero point of charge were closer to that of alum. Filtration experiments revealed that TiO2 nanoparticles, when present in water, could successfully be removed by an alum dose of 8 mg/L. Indeed, removal in excess of 99.5% was achieved under the study conditions. Under the investigated water chemistry conditions, very low attachment efficiencies (?) of 0.001, 0.002 and 0.01, and filter coefficients (?) of -0.003, -0.001 and -0.02 were determined for the filters. Based on the calculated attachment efficiencies, and under the studied conditions, natural nanoparticles remain dispersed in the water and would not likely to be removed by direct filtration. The overall research findings represent a major step forward in nanoparticle removal by direct filtration.

Unintentional injuries are the leading cause of death and disability for youth under 20, and motor vehicle collisions are the leading cause of death in youth aged 15-19 (World Health Organization, 2010). Research has consistently shown that driver education programs do not result in safer youth driving. Indeed, the biggest predictor of collisions involving youth is parental history of collisions. This dissertation comprised two studies – one to develop a measure of risky driving and one that examined the influence of parents on youth risky driving. Participants (N = 432) for both studies were undergraduate students aged 17 to 22 who had obtained their G2 driver’s licence in the past year. In Study 1, exploratory and confirmatory factor analyses of the new Youth Domains of Risky Driving Scale revealed a four-factor solution consisting of aggressive, substance use, distracted, and moving violation subscales. In Study 2, this new measure was used to evaluate relations between parental modeling of risky driving behaviours, parental teaching about safe driving behaviours, and youth risky driving. Results revealed that parental modeling was generally more predictive of youth risk than parental teaching, for all four subtypes of driving behaviours examined. Youth whose parents modeled risky driving behaviour were more likely be willing to drive in a risky manner, to expect that they would do so in the future, and to report a history of risky driving in the past. Findings from this study highlight the role parents play in the development of youth risky driving. Implications for future interventions targeting parent driving behaviour in the early months of youth licensure are discussed. / Canadian Institutes of Health Research

Radio Frequency IDentification (RFID) is growing prominence as an automated identification technology able to turn everyday objects into an ad-hoc network of mobile nodes; which can track, trigger events and perform actions. Energy scavenging and backscattering techniques are the foundation of low-cost identification solutions for RFIDs. The performance of these two techniques, being wireless, significantly depends on the underlying communication architecture and affect the overall operation of RFID systems. Current RFID systems are based on a centralized master-slave architecture hindering the overall performance, scalability and usability. Several proposals have aimed at improving performance at the physical, medium access, and application layers. Although such proposals achieve significant performance gains in terms of reading range and reading rates, they require significant changes in both software and hardware architectures while bounded by inherited performance bottlenecks, i.e., master-slave architecture. Performance constraints need to be addressed in order to further facilitate RFID adoption; especially for ultra large scale applications such as Internet of Things. A natural approach is re-thinking the distributed communication architecture of RFID systems; wherein control and data tasks are decoupled from a central authority and dispersed amongst spatially distributed low-power wireless devices. The distributed architecture, by adjusting the tag's reflectivity coefficient creates micro interrogation zones which are interrogated in parallel. We investigate this promising direction in order to significantly increase the reading rates and reading range of RFID tags, and also to enhance overall system scalability. We address the problems of energy-efficient tag singulations, optimal power control schemes and load aware reader placement algorithms for RFID systems. We modify the conventional set cover approximation algorithm to determine the minimal number of RFID readers with minimal overlapping and balanced number of tags amongst them. We show, via extensive simulation analysis, that our approach has the potential to increase the performance of RFID technology and hence, to enable RFID systems for ultra large scale applications. / Thesis (Ph.D, Computing) -- Queen's University, 2011-08-30 23:41:02.937

In this thesis, the redundancy resolution and failure analysis of Cable-Driven Parallel Manipulators (CDPM) are investigated. A CDPM consists mainly of a Mobile Platform (MP) actuated by cables. Cables can only apply force in the form of tension. So, to design a fully controllable CDPM, the manipulator has to be redundantly actuated (e.g., by using redundant cables, external force/moment or gravity). In this research, the redundancy resolution of planar CDPMs is investigated at the kinematic and dynamic levels in order to improve the manipulator safety, reliability and performance, e.g., by avoiding large tension in the cables that may result in high impact forces, and avoiding large MP velocities that may cause instability in the manipulator, or on the contrary, by increasing the cable tensions and the stiffness for high-precision applications. The proposed approaches are utilized in trajectory planning, design of controllers, and safe dynamic workspace analysis where collision is imminent and the safety of humans, objects and the manipulator itself are at risk. The kinematic and dynamic models of the manipulator required in the design and control of manipulators are examined and simulated under various operating conditions and manufacturing automation tasks to predict the behaviour of the CDPM. In the presented research, some of the challenges associated with the redundancy resolution are resolved including positive tension requirement in each cable, infinite inverse dynamic solutions, slow-computation abilities when using optimization techniques, failure of the manipulator, and elasticity of cables that has a significant role in the dynamics of a heavy loaded manipulator with a large workspace. Optimization-based and non-optimization-based techniques are employed to resolve the redundancy of CDPM. Depending on the advantages and disadvantages of each method, task requirements, the used redundancy resolution technique, and the objective function suitable optimization-based and non-optimization-based routines are employed. Methodologies that could combine redundancy resolution techniques at various levels (e.g., position, velocity, acceleration, and torque levels) are proposed. / Thesis (Ph.D, Mechanical and Materials Engineering) -- Queen's University, 2012-09-26 22:39:34.35

No description available.

Thesis (M.Tech.:Civil Engineering)-Dept of Civil Engineering and Survey, Durban Institute of Technology, 2005 xiv, 134 leaves, Annexures A-C / Road fatalities claim more than one million lives annually worldwide. The emotional, social and economic impact of road traffic fatalities demands urgent attention globally. This epidemic of road traffic fatalities is plaguing everyone, especially the poorer nations. Some countries like Australia and Sweden have been more successful than others in combating this epidemic. South Africa is currently seeking strategies to combat this epidemic because South Africa’s road traffic fatalities have been increasing annually, with a substantial percentage of teenagers and young adults between the ages of 16 and 29 contributing to these statistics. This age group will become or already have become part of the economically active population and concern is mounting as to why this particular age group is vulnerable. This thesis provides an overview of the road safety problem globally, nationally, provincially and locally and also looks at the historical factors that have contributed to this problem. The Victorian model, which has been classified as the ‘world’s best practice’, has been reviewed. A pilot survey was conducted at the Mangosuthu Technikon and the focal survey was conducted at the tertiary institutions in the Durban area. Students from this sector were selected as they fall in the most vulnerable age group and data was collected from them on various aspects of road safety. On analysing the data, various problems were identified, in particular, lack of resources and limited education pertaining to road safety. A range of possible solutions is recommended and the focus areas are the 3E’s namely: education, enforcement and engineering. However, the focal recommendation is on education and looks at the possibility of introducing learner’s licence testing to the grade 12 syllabi.