title: Molecular characterization of GABA receptor subunits from the parasitic nematode Haemonchus contortus

contributor:
Forrester, Sean
Bonetta, Dario

subject:
GABA
Ligand-gated chloride channel
Electrophysiology
Homomeric channel
Haemonchus contortus
Heteromeric channel

abstract:
Haemonchus contortus is a parasitic nematode that is controlled by several nematocides
which target ion channels. We have identified two H. contortus ion channel genes, Hcounc-
49B and C that encode two GABA-gated chloride channel subunits.
Electrophysiological analysis shows that the Hco-UNC-49B subunit forms a functional
homomeric channel in Xenopus laevis oocytes that produces a robust response to GABA
and is highly sensitive to picrotoxin. In contrast, Hco-UNC-49C alone does not respond
to GABA but can assemble with Hco-UNC-49B to form a heteromeric channel with an
increased sensitivity to GABA and a lower sensitivity to picrotoxin. To investigate the
subunit requirements for high agonist sensitivity, we generated cross-assembled channels
by co-expressing the H. contortus subunits with UNC-49 subunits from the nematode
Caenorhabditis elegans (Cel-UNC-49). Co-expressing the Cel-UNC-49B with Hco-
UNC-49C produced a heteromeric channel with a low sensitivity to GABA. In contrast,
co-expressing Hco-UNC-49B with Cel-UNC-49C produced a heteromeric channel that
was highly sensitive to GABA. These results suggest that the Hco-UNC-49B subunit is
the key determinant for the high agonist sensitivity of heteromeric channels.


title: Improving understanding of rape proclivity

subject:
Sexual violence
Rape proclivity
Prevention of sexual violence

abstract: The current dissertation included three studies that together aimed to improve understanding of rape proclivity as a potential construct related to sexual violence. In the first study, participants' understanding of the items on the Rape Proclivity Measure were assessed to gain insight into participants' perspectives about rape scenarios and to examine the content validity of the measure. Most participants (68.7% to 95.8%) did not view the wording of scenarios as ambiguous, and understood scenarios as incidents of sexual violence, indicating that the Rape Proclivity Measure is comprehensible and has good content validity. However, participants were more likely to label rape scenarios involving: (a) a stranger perpetrator, and (b) use of physical force, as incidents of rape, indicating that their definition of rape matches the rape scripts prevalent in North America. The second study examined the relationship between rape proclivity and various correlates of rape, namely deviant sexual interests, offence supportive cognition (both rape and antisocial), and history of past sexually aggressive behaviour. The aim was to identify the most relevant variables, and to evaluate whether rape proclivity forms a distinct construct or whether it overlaps substantially with one of these other constructs. There was a strong correlation between rape proclivity and correlates of rape. However, in a factor analyses, the various measures of rape proclivity did not form a distinct construct indicating that different measures of rape proclivity may not be assessing the same construct. Finally, the third study aimed to address the gap in the literature regarding the role of rape proclivity, assessed by rape proclivity measures, as a predictor of sexually aggressive behaviour. Results indicated that rape proclivity measured by Sexual Experience Survey-Tactics First Revised (SES-TFR) predicted future sexual violence, but the Rape Proclivity Measure did not. This means that rape proclivity may be a factor related to the perpetration of sexual offending, but care must be taken in the measures that are used. Once proclivity can be identified in a reliable and valid manner, it can be targeted in programs designed to prevent sexual violence.

abstract: University of Ontario Institute of Technology


title: An examination of the impact of corroborator age on alibi assessment

subject:
Alibi assessment
Crime perceptions
Corroborator
Credibility
Child witness

abstract: The purpose of the current research was to assess the impact of the age of an alibi corroborator on the perceptions and decision-making of alibi assessors. Across two studies, adult participants were asked to assume the role of a police detective and to assess the alibi of an armed robbery suspect. The alibi contained a single individual that was willing to verify the suspect’s account (i.e., an alibi corroborator). In Study 1, I examined the impact of the alibi corroborator’s age (i.e., 8-year-old vs. 25-year-old) and relationship with the suspect (i.e., stranger vs. neighbour vs. son) on ratings of five dependent measures related to corroborator credibility and suspect guilt. In Study 2, I examined the impact of the alibi corroborator’s age (i.e., 4-year-old vs. 8-year-old vs. 25-year-old) and the level of cognition needed to remember the alibi event (i.e., delayed vs. recent event) on the same five dependent measures. Consistent with a two-factor model of witness credibility, results indicated that participants viewed an 8-year-old corroborator more favourably than a 4- or 25-year-old corroborator. Participants also demonstrated increased skepticism when the corroborator was interviewed after a longer delay as well as when the corroborator was related to the suspect. The current results help to shed light on an existing inconsistency in the alibi literature regarding the impact of corroborator age on alibi assessment outcomes.


title: Optimized multi-superframe scheduling for clustered wireless sensor networks

subject:
Wireless Sensor Network (WSN)
LEACH clustering
IEEE 802.15.4e
Multi-superframe
Differential Evolution (DE)

abstract: Since the power source for wireless sensor networks (WSN) is mainly from batteries, prolonging network life is an important requirement of the network. Hence, clustering algorithms are employed to decrease the number of packets in the network via data aggregation as well to reduce packet network collisions by adopting scheduled communication among nodes in a cluster. The composition of the superframe plays an important role in scheduling the communication among the nodes in the network as well as determining the application data rate of acquisition. The differential evolution (DE) algorithm is used to fulfill the objective, to maximize network life under different data acquisition rate. The data acquisition rate is dependent on the IEEE 802.15.4e superframe. In addition, the multi-superframe structure is utilized to enable nodes to conserve more energy. The proposed method provides a set of solutions, based on the constraints and goals.


title: Thermal aspects of high efficiency channel with conventional and alternative fuels in SuperCritical water-cooled reactor (SCWR) applications

contributor:
Pioro, Igor
Gabriel, Kamiel

subject:
SCWR
Fuel centerline temperature
Alternative fuels
High efficiency channel
Heat loss

abstract:
Chosen as one of six Generation‒IV nuclear-reactor concepts, SuperCritical Water-cooled Reactors (SCWRs) are expected to have high thermal efficiencies within the range of 45 ‒ 50% owing to reactor‘s high outlet temperatures. A generic pressure-channel (or pressure-tube)SCWR operates at a pressure of 25 MPa with inlet- and outlet-coolant temperatures of 350°C and 625°C. Consequently, the sheath and fuel centerline temperatures are higher in SCWRs than those of the current nuclear reactors. Previous studies have shown that the sheath and fuel centerline temperatures could exceed the design and industry accepted limits of 850°C and 1850°C, respectively. These studies correspond to UO2 enclosed in a 43-element fuel bundle at an average thermal power per channel of 8.5 MWth. Additionally, these high operating conditions in the range of 350 - 625°C lead to high heat losses from the coolant to the moderator, which in turn reduces the overall thermal efficiency of the Nuclear Power Plant (NPP). Therefore, there is a need for alternative fuels or fuel bundles for future use in SCWRs. Hence, it is also necessary to determine the amount of heat losses from a number of fuel-channel designs for SCWRs.
The objectives of this study are to investigate the possibility of using alternative fuels and to determine the heat losses from a fuel-channel design at SCWR conditions. The investigated fuels are categorized as low thermal-conductivity (e.g., UO2, MOX, and ThO2), high thermal-conductivity (e.g., UC, UC2, UN), and enhanced thermal-conductivity (e.g., UO2‒SiC, UO2‒C, and UO2‒BeO) fuels. Additionally, the examined fuel channel is the High Efficiency Channel (HEC), which has been designed by the Atomic Energy of Canada Limited (AECL) for the proposed CANDU SCWR.
In order to achieve the objectives of this study, a steady-state one-dimensional heat-transfer analysis was conducted. The MATLAB© and NIST REFPROP© software were used for programming and retrieving thermophysical properties of a light-water coolant, respectively. The fuel centerline temperature was calculated for the fuel channels with the maximum thermal power, i.e., +15% above average channel power. Results of this analysis showed that the fuel centerline temperatures of low thermal-conductivity fuels exceed the industry limit; therefore, either a fuel with a higher thermal conductivity should be used or the fuel bundle geometry must be modified. Among the high thermal-conductivity fuels, UC has been shown to be a candidate for future use in SCWRs. However, the chemical compatibility of UC with water at high operating temperatures of SCWRs remains ambiguous. Therefore, further studies are required before selecting UC. In regards to enhanced thermal-conductivity fuels, UO2‒BeO is the most suitable candidate; however, its mechanical and neutronic properties must be thoroughly studied before any decision is made with regards to the selection of a fuel.
In regards to the heat losses from the examined fuel channel, the heat loss was between 70 kW and 110 kW per fuel channel based on an average thermal power per channel of 8.5 MWth and a moderator pressure of 0.1 MPa at 80°C. A sensitivity analysis of the fuel channel shows that the heat loss can be reduced by increasing the operating pressure of the moderator, which in turn allows for increasing the operating temperature of the moderator. Higher operating temperatures of the moderator result in smaller temperature differences between the coolant and the moderator, which leads to lower heat losses. Therefore, either the thickness of the insulator or the pressure of the moderator should be increased in order to reduce the heat losses from the fuel channel.


title: Fault tolerant behavior of advanced control schemes of induction machine drives

subject:
Induction machine drives
Variable speed drives
Direct torque control
Field oriented control
Fault analysis of ac drives

abstract:
Power electronics based variable-speed drives offer energy saving solutions, providing precise control and quick response time. They are required for sensitive process control in industrial applications and other emerging technologies such as electric vehicles.
This thesis examines two popular advanced control schemes of variable-speed induction machine drive applications. The two advanced control schemes, Indirect Field oriented control (IFOC) and Direct torque control (DTC), are compared by examining their implementation complexity, parameter sensitivity, dynamic responses, steady state performance and, most importantly, under power line fault scenarios. MATLAB-Simulink package is used to develop system models for both control schemes. System studies are done under normal and abnormal operating conditions. In the end, conclusions are drawn based on their behavior and comparison of performance characteristics under dynamic and AC fault (single-line to ground, phase to phase and triple-line to ground) conditions, highlighting the fault tolerant characteristics of the two drive schemes.


title: Joint relay beamforming and transceiver processing in multiuser relay network

subject:
Peer-to-peer
Multi-way multi-antenna
Relay beamforming
Semidefinite relaxation

abstract:
In this thesis, we focus on joint relay beamforming and transceiver processing in multiuser relay network. First of all, we consider the scenario in which multiple source-to-destination (S-D) pairs intend to communicate with the help of multiple distributed
amplify-and-forward (AF) relays. A rank-two beamforming Alamouti scheme is proposed
at the sources and relays, and we aim to minimize maximal individual relay
power subject to pre-defined SINR requirements. The resulting non-convex optimization
problem is solved by ordinary semi-definite relaxation (SDR) and separable SDR
approaches. Compared to conventional rank-one scheme, proposed rank-two methods
provide one more degree of freedom in optimal solution, and have significantly better
performance in terms of min-max per-relay power and optimality gap.
Secondly, we consider the scenario where multiple users exchange information with
each other via a multi-way multi-antenna relaying. Our objective is to jointly design
both relay beamforming and receiver linear processing to maximize the minimum
signal-to-interference-and-noise ratio (SINR) under a relay power budget. The joint
optimization problem is iteratively solved by designing relay beam matrix and receiver
processing matrix. For the latter, both maximum-ratio-combining (MRC) receiver
and zero-forcing (ZF) receiver are designed. The MRC receiver leads to the optimal
iterative design while the ZF receiver has lower computational complexity. We also use
successive interference cancellation (SIC) as our decoding strategy to further enhance
sum-rate. Simulation results show that the proposed iterative algorithm yields higher
achievable sum-rate than the existing partial ZF (PZF) method which uses sum-rate
maximization as the design objective.


title: Audiovisual multisensory integration in young adults with and without a diagnosis of Attention-Deficit/Hyperactivity Disorder

contributor:
Yielder, Paul
Murphy, Bernadette

subject:
Multisensory integration
ADHD
EEG
Response time
Audiovisual

abstract: Attention-Deficit/Hyperactivity Disorder (ADHD) is a neurodevelopmental disorder with behavioural and neurophysiological characteristics. Several cortical structures that are altered in ADHD are involved in the process of multisensory integration (MSI). MSI is a fundamental form of sensory processing involved in many everyday tasks. Therefore, it is important to know whether those with ADHD experience altered MSI. Two different paradigms were used to assess MSI in adults with a diagnosis of ADHD. First, a simple response time (RT) task was completed. Electroencephalography (EEG) analysis revealed that those with ADHD had MSI occur, while there were significant differences in brain activity between groups. Study two employed a two-alternative forced-choice discrimination task. Those with ADHD responded faster than controls. EEG analysis revealed that those with ADHD have enhanced MSI. Activity differences were found in brain regions that are structurally altered in those with ADHD, indicating that structural alterations in ADHD may promote sensory processing.


title: Time-frequency analysis techniques for non-intrusive load monitoring

subject:
NILM
Wavelet design
Load disaggregation
Transient analysis

abstract:
The work
in this thesis examines time-frequency analysis techniques and in particular the wavelet
transform to extract the features contained within the electrical load signals. A novel approach
that is based on wavelet design was utilized to generate a wavelet library which was used to
match each load signal to a specific wavelet using Procrustes and covariance analysis. In order
to automate the load identification process, two machine learning classifiers representing an
eager learner and a lazy learner were used in this work. The proposed wavelet design concept
has been verified experimentally, and the results of implementing the proposed load detection
and classification approach shows significant improvement in the classification accuracy
compared to other existing detection approaches reaching an overall accuracy of 98%.


title: Jointly optimal pre- and post-channel equalization and distributed beamforming in asynchronous bi-directional relay networks

subject:
Pre- and post-channel equalization
Distributed
Beamforming
Bi-directional
Relay networks

abstract: We consider an asynchronous two-way relay network, consisting of two transceivers and multiple relays, where due to the propagation delays of different transceiver-relay paths being different, inter-symbol- interference (ISI) exists at both transceivers. In this work, pre- and post-channel equalization blocks are used to combat ISI. The mean-squared error of the estimated received signals at both transceivers is minimized under a total transmit power budget by optimally obtaining the transceivers’ powers and relay beamforming weight vectors as well as pre- and post-channel equalizers at the two transceivers. We prove that our proposed approach results in a certain relay selection scheme.


title: Single copy gene expression system as a tool for the purification of membrane proteins from Pseudomonas aeruginosa

subject:
Membrane proteins
RND efflux
Antibiotic resistance
His-tag purification
Single-copy gene expression system

abstract: Pseudomonas aeruginosa is a Gram-negative opportunistic human pathogen known to cause a variety of infections that are difficult to treat due to extremely high resistance to almost all antibiotics currently in clinical use. One of the major contributors to this resistance is the active efflux of antibiotics from the cell, primarily by action of the Resistance Nodulation Division (RND) family of efflux pumps. These pumps are composed of three proteins; an inner membrane RND pump, a periplasmic membrane fusion adaptor protein, and an outer membrane protein. The mechanism by which the three proteins interact to form a functional complex is largely unknown and the methods currently available for their study involves expression systems geared for high levels of expression. In the case of membrane proteins which play a role in clinically relevant activities, such as multidrug resistance, an expression system which does not always reflect biologically relevant levels of protein in the cell is not ideal for studying their interactions as correlation of conclusions from interaction studies to true interactions may not be possible. In this study a single copy gene expression system was designed and demonstrated to better reflect clinically relevant levels of overexpression compared to a multi-copy expression system. Quantitative-real time PCR analysis of C-terminally hexa-histidine tagged outermembrane protein, OpmH, expression shows approximately 100-fold and 20-fold overexpression from multi-copy and single-copy expression systems respectively. OpmH-H6 was successfully purified from both multi copy and single copy expression systems with proportionate purification schemes indicating the feasibility of single copy expression systems for the study of membrane bound protein complexes.


title: Reasons for concussion under-reporting in varsity athletes: a mixed methods approach

subject:
Concussion
Sport
Education
Mixed-methods
Symptom reporting

abstract:
Sport-related concussion is an increasing challenge for student-athletes, medical staff, and faculties to manage in post-secondary institutions. Delayed assessment and management leads to increased time away from class and sport, and low reporting rates among athletes contribute to poor recovery rates and potential long-term consequences. The purpose of this study was to utilize a mixed-methods approach to examine concussion education, attitudes, and reporting intention and behaviour, to explore reasons why varsity athletes fail to report concussions.
Results indicated that athlete knowledge of signs and symptoms of concussion is very high, but that decision-making process that athletes undergo to report concussions leads to unsafe reporting behaviours. Themes of knowledge, non-reporting influences, and high thresholds to report create complex inter- and intra-personal messages that over-ride education and lead to non-reporting of concussions.
The results of this study suggest that education programs need to address the influence of sport-culture, personal attitudes and beliefs, and external messages that varsity athletes receive in order to improve reporting rates.


title: Reliability analysis of smart electrical transmission system and reliability modeling through dynamic flowgraph methodology

subject:
Dynamic flowgraph methodology
Smart electrical transmission system
Reliability modeling

abstract: Reliability assessment methods allow the evaluation of the reliability of systems and provide important information on how to improve a system‟s life to reduce risk and hazards. With the advancement in technology, the existing methods were extended and new methods were adopted. The advancement from mechanical to numerical and analog to digital system in many applications, and deregulation of energy sector brought the need to further modify the reliability analysis methods. The scope of this research is to demonstrate the advancement of the Dynamic Flowgraph Methodology (DFM) to reliability modeling of Smart Electrical Transmission System. The reason behind this is the successful operation of electric power under a deregulated electricity market depends on transmission system reliability management. Besides this, analog electro-mechanical systems in existing power system are aging and becoming obsolete. This thesis also illustrates how the electrical transmission system can be renovated into smart electrical transmission system and evaluates the reliability measures.


title: Performance analysis of gas turbine cogeneration systems.

contributor:
Reddy, B.V.
Agelin-Chaab, Martin

subject:
Gas turbine cogeneration systems
Steam injection
Energy analysis
Exergy analysis
CO2 emmissions
Specific heat

abstract:
Cogeneration is a highly efficient approach to generating electricity and process heat
from the same fuel source. It is an approach of utilizing waste energy products for a
useful purpose that significantly improves the optimal provision of the different grades
of energy from high-quality, high-grade electricity or power to low quality and low-grade
heat. As a result, combined heat and power can be applied to various situations using
various technologies.
In the present work, performance of two gas turbine cogeneration systems is analyzed
using the first and second laws of thermodynamics. A basic gas turbine cogeneration
system and a steam injection gas turbine cogeneration system are investigated. In the
analysis the system components, compressor, combustion chamber, turbine and heat
recovery steam generator are modeled. The CO2 emissions of both systems are also
evaluated. In this investigation the decrease in CO2 emissions was found in the steam
injected gas turbine cogeneration system as compared to the basic gas turbine
cogeneration system.
In the parametric study the influence of pressure ratio and turbine inlet temperature on
the performance characteristics of the systems such as specific work, energy and exergy
efficiencies are investigated. In the efficiency calculations all the three forms of outputs:
power, heat and cogeneration are considered. Thus power generation, heat generation
and cogeneration efficiencies are estimated. The carbon dioxide emissions are
estimated for both systems. In addition, the effect of pressure ratio and turbine inlet
temperature on the CO2 emissions is studied. The results show that pressure ratio and
turbine inlet temperature are the key operating variables to optimize the performance
of the cogeneration systems.
The second law analysis revealed that the maximum exergy destruction occurs in the
combustion chamber. In this analysis, the chemical and physical component of the
exergy is considered.
The role of specific heat as the function of temperature in estimating the performance
of cogeneration is also investigated and the performance results are compared with the
results assuming constant specific heat. The results with specific heat as the function of
temperature are more realistic and accurate compared to the actual performance of the
cogeneration systems.
The analysis and the results are useful for optimizing the operating parameters of the
gas turbine cogeneration systems and thereby enhancing the system performance. The
study is also useful for choosing appropriate cogeneration system for a specific
application.


title: Examining the practice approaches used by registered dietitians in Canada when working with higher weight adults

subject:
Implementation
Practice approaches
Weight stigma
Registered dietitian
Weight inclusive

abstract: A cross-sectional, national, online survey of Canadian Registered Dietitians (RDs) was conducted to explore the various practice approaches used when working with higher weight adults. Specifically examined was the use of non-weight focused approaches (NWFAs), and the barriers and facilitators for implementation. NWFAs deemphasize the importance of body weight with respect to adults’ nutrition and health. A comprehensive literature search identified only one study, conducted in Australia, that examined the diverse approaches regarding weight used by RDs. Other studies have examined RDs’ use of single practice approaches. There were no studies that explored the implementation of NWFAs in Canada or nationally. Overall, this thesis presents research that demonstrates that NWFAs are the dominant practice approach being used by Canadian RDs when working with higher weight adults. It also identifies the key barriers and facilitators that RDs experience when implementing NWFAs into practice, across a spectrum of readiness to implement NWFAs.


title: Effects of blade configuration on flow distribution and power output of a zephyr vertical axis wind turbine.

contributor:
Naterer, Greg F.
Rosen, Marc

subject:
advanced heat transfer
advanced energy systems
fuel cells and hydrogen systems
wind power and small scale hydropower
solar cells and solar collectors

abstract: Worldwide interest in renewable energy systems has increased dramatically, due to environmental concerns like climate change and other factors. Wind power is a major source of sustainable energy, and can be harvested using both horizontal and vertical axis wind turbines. This thesis presents studies of a vertical axis wind turbine performance for applications in urban areas. Numerical simulations with FLUENT software are presented to predict the fluid flow through a novel Zephyr vertical axis wind turbine(VAWT). Simulations of air flow through the turbine rotor were performed to analyze the performance characteristics of the device. Major blade geometries were examined. A multiple reference frame (MRF) model capability of FLUENT was used to express the dimensionless form of power output of the wind turbine as a function of the wind freestream velocity and the rotor's rotational speed. The simulation results exhibit close agreement with a stream-tube momentum model.


title: An integrated big data framework utilizing stream computing to support real-time clinical decision-making in the field of space medicine

subject:
Clinical decision support system
Space medicine
Big data
Adaption-based assessment
Human-technology systems

abstract: Space exploration continues to be one of greatest endeavours of humankind. As manned space exploration extends to deep space, destinations such as the Moon and Mars, technological improvements and scientific advancements are in order, so as to enable safe prolonged human presence in space. Existing challenges of medical care delivery in space need to be addressed, while the meaningful and practical use of the acquired data will enable greater understanding of the impact of space travel on humans. This thesis proposes a novel wholistic approach to the human-technology ecosystem, enabling integration of the various components to address existing challenges of fragmented, retrospective discontinuous file-base data acquisition, in-batch data processing, extensive data down-sampling and an enormous amount of data loss. It presents an innovative solution to support proactive prognostics, diagnostics and health management, while providing the necessary tools to support action-taking and informed decision-making within the field of space medicine.


title: Military and the media examining the wartime framing of Canada’s involvement in Afghanistan

contributor:
Hinch, Ron
Mirrlees, Tanner

subject: Canada Afghanistan Media War Framing

abstract: Through a content analysis of 72 print news articles and 12 official sources disseminated following the 2010 troop surge in Afghanistan, this study contends that the relationship between the major print news media and the Canadian government in times of war is characterised by a broad and diffused array of media frames. The National Post, Toronto Star, and Globe and Mail were found to publish a variety of politically and thematically diverse articles. Robert Entman’s framing theory will be used to explain how the Canadian print media framed the war in Afghanistan. It will be shown that the Canadian print media is best described as heavily influenced by the official framing but free to offer dissenting options and divergent frames. These findings offer insight into the role of the press within Canada’s liberal democracy and contribute to the research surrounding the normative theories of the press and their applicability in Canada.


title: The effect of concurrent mental and physical fatigue on physical endurance performance, strength and muscle activity: a pilot study

contributor:
La Delfa, Nicholas
Graham, Jeffrey

subject:
Neuromuscular fatigue
Mental fatigue
Ergonomics
Force fluctuation
Endurance time

abstract: A significant amount of research focus has been dedicated to physical and mental fatigue individually, but their combined effects on physical performance are relatively underexplored. As such, the purpose of this pilot study was to evaluate the concurrent effects of mental and physical fatigue on upper limb neuromechanics and endurance performance, compared to just mental fatigue and physical fatigue elicited independently. Initial findings from this thesis provide initial support for concurrent mental and physical fatigue detrimentally affecting handgrip endurance and strength when compared to the mental fatigue and control conditions. As this pilot study was conducted to inform a larger planned data collection, several other areas for refinement in the protocol were identified, notably the addition of a familiarization session, utilizing only one post-measurement endurance trial, removing upper and lower ranges during the endurance trial, and adding the flexor carpi ulnaris muscle alongside the muscles used in this pilot study.

abstract: University of Ontario Institute of Technology


title: Development and analysis of a new direct steam generation-based parabolic trough collector power plant hybridized with a biomass boiler

contributor:
Agelin-Chaab, Martin
Reddy, Bale

subject:
Solar
Biomass
Sustainability
Power generation
Environment

abstract: Direct steam generation (DSG) is the process by which steam is directly produced in parabolic trough fields and supplied to a power block. This process simplifies parabolic trough plants and improves cost effectiveness by increasing the permissible temperature of the working fluid. In the present work, an innovative DSG plant hybridized with a biomass boiler is proposed and analyzed in detail. Two additional configurations comprising indirect steam generation in parabolic trough collector (PTC) plants were also analyzed in order to compare their energy and exergy performance. In addition, energy and exergy analyses of DSG are conducted and compared to an existing indirect steam generation PTC power plants such as the Andasol. To further understand the biomass subsystem, multiple fuels were presented and analyzed in detail. The obtained results indicate that the proposed DSG-based PTC plant is able to increase the overall system efficiency by 3% in comparison to indirect steam generation when linked to a biomass boiler that supplies 50% of the energy.


title: Characterization of natural fibre reinforced biodegradable composities

subject:
Natural fibre
Biodegradable
Light weight
Composites
Properties

abstract:
Low cost, light weight, recyclability, and high specific strength of natural fibres make them a good replacement for synthetic fibre such as glass in fibre reinforced plastics (FRP). Green and ecofriendly source of these fibres offer less reliance on oil sources. However, their moisture uptake ability, low thermal stability and quality variations are some disadvantages that restrict their use.
Biodegradable polymers or biopolymers such as polylactic acid polymers (PLA) are polyesters of lactic acid, and originally made from renewable agricultural raw materials e.g. corn starch. Development of new composite products from the existing renewable resources has a strong potential to bring a new biodegradable composite material suitable for the automotive and packaging industry to replace non-renewable petroleum based plastics. These biodegradable composites could degrade completely in soil or by composting process and do not emit any toxic or harmful components.
The purpose of this work is to investigate the effects of increasing natural fibre content, and also adding Biomax modifier on the mechanical properties of poly lactic acid. PLA was reinforced with two different kinds of sustainable natural fibres, cotton, and jute fibres respectively. Biomax strong 120 was used as modifier for PLA/natural fibre composites in order to improve the impact strength and toughness properties. Mixtures of different fibre mass proportions as reinforcement, and PLA as a base resin with modifier additive were compounded in a twin-screw extruder. The extruded materials were processed in a novel compression moulding system to produce test samples. Composites without any modifier content were also produced under the same conditions and used as reference materials.
iv
Addition of plant fibres to the PLA reduces the composites flexural strength, while improves the elastic modulus significantly, compared to neat PLA. PLA 3001D based composites containing 40% jute fibre exhibited the highest stiffness (5.9 GPa) amongst the composites. Investigation of the impact properties of the composites showed that increasing fibre mass proportion leads to an increase in the impact strength of the composites. The impact strength of the PLA/cotton composite is more promising than PLA/Jute composites. The most significant result is that addition of even 3% Biomax Strong 120 had a positive effect on the impact properties of the specimens.
Analysis of the rheological properties of the composites demonstrates that the cotton fibre reinforced PLA has higher complex viscosity than Jute fibre reinforced PLA composites. The DSC results explain that the crystallization temperature increases with increasing the jute fibre content. Furthermore composite‟s microstructure was monitored using Scanning Electron Microscope (SEM). A better adhesion between the cotton fibres and the PLA matrix than jute fibres and PLA was observed in the SEM images.


title: Design and development of multifunctional energy harvesting and storage systems for sensor applications

subject:
Energy harvesting
Tire
Piezoelectric
Sensor
Multifunctional

abstract:
This research focuses on the design and development of multifunctional components intended to provide three basic functions: (i) power generation, (ii) power storage, and (iii) structural support. They are made of composite multi-material systems that include
smart materials. By combining various functions into the same component significant performance, weight, space, assembly and packing benefits can be achieved. A major portion of this thesis is devoted to the use of piezoelectric layers in order to generate few
milliwatts of power and enhance the utility of electrical mobility products and subsystems while facilitating new venues for implementing such devices. Shoes and pneumatic tires were used to harvest energy from their innate motion and various useful applications of harvested energy have been demonstrated in the form of sensors and power sources for
larger devices.
Shoe-based power generation can be used for charging Radio Frequency IDentification (RFID) tags, GPS sensors, portable electronics, etc. Tire-based power generation can be used for powering battery-less wireless Tire Pressure Monitoring Systems (TPMS),
wireless Vehicle Speed Sensors (VSS), tire health monitoring sensors, etc. Fully functional proof-of-product prototypes of a variety of multifunctional components were developed and subjected to experimentation and testing using custom designed and built
lab-scale made experimental machinery. Contrary to the paradigm, the possibility of using piezoelectric materials in automotive tires to produce few watts of power (>2 watts) has been successfully demonstrated with applications ranging from powering more demanding sensors to onboard batteries. An Electronic Vehicle Control System (EVCS)
with electronic differential and cruise control capabilities has also been designed, developed and tested on the Extended Range Plug-In Hybrid vehicle previously developed at UOIT.


title: The shift from “muffins” to mangoes: child, family, and organizational impacts of an after-school snack program

subject:
Nutrition
Child obesity
After-school program

abstract: In 2009 alarming rates of childhood obesity resulted in the Government of Ontario launching a province-wide initiative through the Ministry of Health Promotion & Sport. This study focused on Eastview Boys and Girls Club (Eastview unit) in Oshawa, Ontario and examined immediate impacts of an after-school snack program involving close to 100-children daily. Data collection included key informant interviews (n=7); one focus group interview with parents (n=8); three interactive children‟s sessions, and document review. Findings identified changes in children‟s eating behaviours (e.g., willingness to try new foods) and shifts in staff attitudes (e.g., role-modelling). Facilitators included staff commitment, strong partnerships, and previous program accreditation. Organizational barriers included gaps in nutrition-related knowledge/skills of staff and insufficient program-specific training and resources. Recommendations call for building capacities at individual-, organizational- and community-levels to strengthen the nutritional component of the after-school initiative. Future research should evaluate long-term outcomes of the snack program.


title: Synthesis and characterization of nanostructured catalysts for photovoltaic applications

contributor:
Trevani, Liliana
Gaspari, Franco

subject:
TiO2
DSSC
Supercritical CO2
Morphology
Sol-Gel

abstract:
The objective of this project was to investigate the effect of the morphology of titanium
dioxide (TiO2) nanoparticles on the electron transport properties and light harvesting potential in
a dye sensitized solar cell (DSSC). Particular attention was given to develop synthetic methods
to produce metal oxide photocatalysts with similar crystallite size, with different morphologies
(spheres, fibers, hierarchical spheres, and globular structures) with the aim of studying the
relationship between morphology and photocatalytic activity. The addition of CNTs to the
synthesis showed that they acted as nucleation sites and altered the morphology. Materials were
fully characterized using Raman, SEM, XRD, BET, and FTIR.
The photocatalytic activity of the as-synthesized materials was tested in a DSSC
configuration and characterized using electrochemical impedance spectroscopy. It was found that
the different morphologies had different light scattering properties which influenced the
efficiencies. Based on these preliminary results, the nanofibres prepared in heptane performed
the best, with good dye loading, electron lifetime and diffusion coefficient. The addition of a
scattering layer using hierarchical spheres showed promising results in decreased transparency
and increased efficiency. The addition of CNTs had an adverse effect, this could be due to light
blocking by the black CNTs and increased recombination with the electrolyte.


title: Design and implementation of a single phase modified Z-source inverter topology for photovoltaic/grid interconnected DC charging applications

subject:
Electric vehicles
Solar inverter
Residential DC charging
Plug-in
Z-source

abstract:
Solar energy has been the most popular sources of renewable energy for residential and
semi-commercial applications. Solar energy sources alone cannot be used to charge an
electric vehicle (EV). Solar/Grid interconnected charging stations are used to charge
EV batteries to reduce the dependency on the grid and enable charging at convenient
locations such as a residential garage or a parking lot right next to an office or a shopping
mall.
The Z-source inverter (ZSI) topology achieves voltage boost and DC-AC power conversion
in a single stage. In this thesis, the design and implementation of a modified
ZSI (MZSI) based charging topology for PV/EV/Grid interconnected application has been
presented. The operation of the proposed topology was verified. The proposed topology
reduces the number of conversion stages to charge EVs from a Smart Grid/PV interface
(high efficiency).
A 3.3 kW MZSI has been designed and simulated using PLECS. Detailed loss modeling
was done using PLECS. The peak efficiency of 94% was observed under irradiation
and temperature changes. A scaled-down version of the proposed topology has been
implemented for proof of concept.
In a single-phase 60 Hz inverter, the 120 Hz component has to be suppressed. One
way is to size the capacitance in the system to absorb the 120 Hz component which may
result in a bulky system. The design of Active Power Filters (APF) for the ZSI topology
can be tricky because of the shoot-through state. A new DC side active power filter has
been proposed for ZSI topology which suppresses the 120 Hz component completely
thereby eliminating the need to use electrolytic capacitors in ZSI systems. The proposed
APF can reduce the capacitance by 100 times. Simulation studies have been presented
for the proposed topology.


title: Parent descriptions of the active play behaviours of their twins and triplets with autism

subject:
Autism
Active play
Multiples

abstract: Children with autism engage in active play in different ways than children who are neurotypical, but the active play behaviours of children with autism are not well understood. Research with twins and triplets with autism offers a unique opportunity to explore the active play behaviours of children with autism because children within a twin or triplet sibling group share many similarities (age, access to toys, etc.) enabling the researcher to gain a clear picture of their play behaviours. Through semi-structured interviews, this descriptive phenomenological study aimed to explore and describe the active play behaviours of 19 twins and triplets with autism from the perspective of their parents (N=9). The interviews revealed three main themes including1) parents’ descriptions of active play, 2) parents’ descriptions of social play and 3) active play as a window into a child’s world. The results from this study reveal the diverse play behaviours of twins and triplets with autism; parents described their children engaging in sensory, indoor, outdoor, and organized play and making play choices based on their unique interests, strengths, and motivations. These results suggest that parents value active play as a way to connect with their children and that children with autism may be meeting the definition of active play in non-traditional ways.


title: Modeling mobility patterns

contributor:
Pu, Ken
Zhu, Ying

subject: Hierarchical Clustering Segmentation Mobility Pattern

abstract: This work focuses on analysis and model generation for user mobility patterns given a sequence of observed WiFi signals. Built on the Android platform, the data collection mobile application gathers WiFi sensor readings (BSSID and SSID). The implemented pipeline performs location identification using an online hierarchical timeline clustering algorithm and segmentation algorithm. The segmentation algorithm constructs a tree of location candidates which are then aggregated by a similarity measure based on their BSSID and SSID features. The generated locations are processed to extract mobility patterns. A pattern is a sequence of location transitions which have high information content, high activity over time, and high degree of predictability. Each of these aspects are described by a numerical measure based on statistical properties of the location observations in a feature space.


title: Localization of a robotic crawler for CANDU fuel channel inspection

contributor:
Nokleby, Scott
Waller, Ed

subject: Robotics Localization CANDU Inspection

abstract:
This thesis discusses the design and development of a pipe crawling robot for the purpose of CANDU fuel channel inspection.  The pipe crawling robot shall be capable of deploying the existing CIGAR (Channel Inspection and Gauging Apparatus for Reactors) sensor head.  The main focus of this thesis is the design of the localization system for this robot and the many tests that were completed to demonstrate its accuracy.

The proposed localization system consists of three redundant resolver wheels mounted to the robot's frame and two resolvers that are mounted inside a custom made cable drum.  This device serves the dual-purpose of providing absolute position measurements as well as retrieving the robot if it is inoperable.  The estimated accuracy of the proposed design is demonstrated with the use of a proof-of-concept prototype and a custom made test bench that uses a vision system to provide a more accurate estimate of the robot's position.  The proposed solution shall use radiation hardened resolver wheels, whereas the proof-of-concept prototype used encoder wheels of the same accuracy.

The UKF was selected as the ideal sensor fusion algorithm for use in this application.  Benchmarking was completed to compare the accuracy achieved by the UKF algorithm to other data fusion algorithms.  When compared to other algorithms, the UKF demonstrated the best accuracy when considering all likely sources of error such as sensor failure and surface unevenness.  The test results show that the localization system is able to achieve a worst case positional accuracy of +/- 3.6 mm for the robot crawler over the full 6350 mm distance that the robot travels inside the pressure tube.  This is extrapolated from the test results completed over the shorter length test bench with simulated surface unevenness.

The key benefits of the pipe crawling robot when compared to the current system include: reduced dosage to workers and the reduced outage time.  The advantages are due to the fact that the robot can be automated and multiple inspection robots can be deployed simultaneously.  The current inspection system is only able to complete one inspection at a time.


title: A secure and privacy-preserving incentive framework for vehicular cloud

contributor:
Lin, Xiaodong
Zhu, Ying

format: application/pdf application/pdf

subject:
Vehicular cloud computing
Incentive mechanism
Security and privacy-preserving

abstract:
Vehicular Cloud Computing (VCC) plays a critical role in data generation where a large number of vehicles collect various kinds of sensing resources with large-volume features. While the information that should be collected is essential for the success of VCC applications, how to stimulate the vehicle owners to provide their sensing resources in VCC is also crucial to its success. When vehicle owners choose to contribute their data for economically appealing compensation, they may be concerned about their privacy.
This thesis proposes a promising secure and privacy-preserving incentive mechanism framework for VCC. An incentive to convince vehicle owners with excess on-board capabilities to join in VCC without the risk of privacy disclosure. The incentive mechanism employs game theory to model the interactions between the VCC server and vehicles. With the incentive mechanism, the VCC server, which represents the task announcement can select competent vehicles to collaborate for the announced task, and the vehicle owners can earn payments from their participation. The signcryption technique and homomorphic concept are exploited to achieve mutual authentication between the VCC server and vehicles, and prevent the privacy information of these vehicles from being disclosed.
Moreover, we study the situation in which the VCC server announces a task that can be exploited by a malicious roadside unit to reveal vehicles' privacy. Therefore, we propose a novel secure and privacy-preserving scheme for enhancing security in VCC-based tasks announcement. The proposed scheme combines a multiple receiver signcryption technique with proxy re-encryption in order to protect message content that includes the private information of the vehicles from being disclosed during task announcement.
In addition to the above schemes, while the VCC server is responsible for recruiting vehicles to collaborate for the announced task, it may not be fully trusted, and the disclosure of individual locations has serious privacy implications. Thus, by exploiting Lagrange interpolating polynomials, we design a privacy-preserving location matching mechanism, called LATE, to enable the VCC server determining whether the interested vehicle participant is in a geocast region of a spatial task or not without having any knowledge about the task's geocast regions and the vehicle's location.


title: Water quality and biotic community response to an urban – rural land-use gradient in the Lake Simcoe watershed

subject:
lotic
Water quality
Periphyton
Invertebrates
Lake Simcoe watershed

abstract: Most research in the Lake Simcoe watershed (LSW) has focused on how the lake has responded to changes in nutrients sourced by agriculture, particularly after mitigation measures have been put in place to remedy the lake’s water quality. Nutrient sources from urban areas are not well understood, yet 31% of phosphorus originates from urban tributaries, despite urban land-use accounting for only 12% of total watershed area. Since many urban areas are seeing drastic human population growth and intensification, the impact urban derived stressors have on water quality and biotic communities requires further investigation. The research presented here explored the links between land-use, periphyton nutrient content and biomass, and invertebrate response in lotic surface waters in the LSW. To infer the contribution of cosmetic fertilizer use in the LSW, a community survey was conducted to assess lawn care and fertilizer choices by residents. Overall, the survey results confirmed that cosmetic fertilizer application posed a significant issue in the LSW. The effects of land-use, season, and abiotic parameters on periphyton biomass, nutrient content, invertebrate abundance and biotic composition were investigated using artificial and natural substrates at 14 field sites that represent a gradient from reference to agriculture to urban land-uses. Two consecutive years of sampling found that water quality, particularly nitrate and chloride, from urban land-uses was the same or worse as compared to reference and agriculture land-uses. There was not an increase in periphyton biomass nor change in indicator taxa at urban sites, potentially due to light availability and/or chloride. There was a periphyton nutrient content response between land-uses, however, potential drivers varied. Exploring relationships between established periphyton and invertebrate abundance determined that herbivores exhibited negative relationships with abiotic and biotic predictors, however these varied with season and land-use. The results did highlight that periphyton studies require investigation throughout the complete ice-free year in temperate climates because single season sampling may yield incorrect or incomplete conclusions.


title: A wireless communication based active safety system for articulated heavy vehicles

contributor:
Liscano, Ramiro
He, Yuping

subject:
Adaptive Extended Kalman filter
DSRC
Data time-delay
Lateral Stability
AHV

abstract: To date, various active safety systems, have been developed to improve the safety of road vehicles. This dissertation presents a novel active trailer steering (ATS) system using wireless communication to exchange data among controllers and sensors allocated on the leading and trailing units of an articulated heavy vehicle (AHV). Conventionally, integrating the sensors, actuators, and controllers located on the leading and trailing units of the vehicle needs wired connections. The physical connection at the articulation joint increases the risk of disconnections and damages. Adopting a wireless communication system displays pronounced advantages, including flexibility, cost-effectiveness and ease of maintenance. For AHV's lateral stability control using wireless communication based ATS, addressing the problem of data delay and loss is the main challenge of this study. Innovative solutions have been proposed to tackle the challenges and numerical simulations have been conducted to evaluate the applicability and effectiveness of the proposed techniques for wireless communication based ATS. To this end, a realistic co-simulation platform is designed: the wireless communication based ATS system is constructed in MATLAB/Simulink; the virtual AHV is built in TruckSim; by means of integrating the ATS system and the virtual AHV, the co-simulation can be performed. As a preliminary design, a gain scheduler is introduced to compensate for the effect of data delay and stabilize the AHV. Later, in order to ensure the performance of the ATS control, a Kalman filter-based estimator is introduced. The estimator uses the available dynamic data to estimate the current states of the AHV in case some sensor data is not available. Several design parameters of the communication system based on dedicated short range communication (DSRC) standard such as modulation, quantization, channel estimation algorithm and transmit diversity have been studied. The effect of each parameter on AHV lateral stability is reviewed to propose proper configuration of the DSRC standard. Finally, an adaptive extended Kalman filter is introduced to mitigate the effects of asynchronous time delay on the AHV lateral stability. This thesis initiates the concept of wireless communication based ATS systems for AHVs and provides valuable guidance for such design and development.


title: Reliable peer-to peer multicast streaming

subject:
Peer to peer (P2P)
Multicast
Base tree
Backup tree

abstract: P2P is increasingly gaining its popularity for streaming multimedia contents. The architecture of streaming has shifted from traditional client server architecture to P2P architecture. Although it is scalable and robust it faces its own challenges and problems such as churn. In tree topology frequent joining and leaving of users in search for better quality and reliable streaming makes the P2P network instable. This thesis provides an effective approach to achieve a resilient network for streaming. Relying on a single tree to receive data from single parent may leave the user deprived of getting the data if any of its ancestors leaves the network. Therefore we present an ideal solution to this problem by introducing a backup tree for the existing base tree. The backup tree is constructed based on parameter such as bandwidth and delay. In case of failure of a node, its children along the tree receive the data from the nodes of backup tree. We present an efficient algorithm for the construction of base tree as well as the backup tree which are based on normalization of two entities of nodes: bandwidth and delay. Through mathematical formulation and experimental setups we show that introducing a backup tree for an existing base tree can help provide resilience to the network.


title: Second law analysis of a liquid cooled battery thermal management system for hybrid and electric vehicles

subject:
Entropy
Second law
Heat transfer
Electric vehicle
Battery

abstract:
As hybrid and electric vehicles continue to evolve there is a need for better battery
thermal management systems (BTMS), which maintain uniformity of operating
temperature of the batteries in the vehicles. This thesis investigates the use of an
indirect liquid cooled system, which can be applied to hybrid and electric vehicles.
The design is modeled as part of the UOIT EcoCAR. The predominant focus of this
indirect liquid cooled system is the entropy generation in each of the components
within the system, as well as a total system analysis. Four main components of the
system are the battery module, heat exchanger, pump, and throttle. The battery
module coolant tubes and the entire heat exchanger model are developed. Various
parameters are changed in each component, leading to a decrease in entropy
generation depending on the variable changed. Of the four components identified, the
heat exchanger produced the majority of entropy generation, which leads to an overall
increase in system entropy generation. There are many factors to consider when
designing a liquid cooled BTMS. The new model shows a unique ability to improve
system performance by reducing the entropy generation in the BTMS.


title: Nonlinear vibration and chaotic motion of uniform and non-uniform carbon nanotube resonators.

subject:
Nonlinear vibration
Chaos
Non-uniform carbon nanotube resonators

abstract:
Vibration analysis of carbon nanotubes (CNTs) is very essential field owing to
their many promising applications in tiny instruments. The unique and interesting
properties of CNTs, particularly their mechanical and electrical features, have fascinated
industries and researchers to implement CNTs for production of different
electromechanical devices. Research on vibration behavior of CNTs has been done for a
few decades. Accordingly, a number of mathematical theories have been developed to
analyze the vibration of CNTs. Most of the articles on the vibration of CNTs are focused
on the linear and free vibrations and also, CNTs are supported by linear foundations. The
main goal of this research is to develop nonlinear vibration analysis of CNTs having
geometrical nonlinearity and being rested on nonlinear Winkler and Pasternak
foundations. The nonlinear vibrations of the curved CNTs are developed using the
Eringen theory in conjunction with the Euler-Bernoulli beam model and the thermal
effect is also considered for the vibration of CNTs. The effects of fluid conveying flow,
geometrical nonlinearities and Winkler and Pasternak foundations are studied. Nonlinear
equations of CNTs vibration postulating the longitudinal electromagnetic effect is also
modeled. Furthermore, a new method is developed for the nonlinear vibrations of
freeform carbon nanotube based on the Euler-Bernoulli beam theory in conjunction with
Non-Uniform Rational B-Spline (NURBS). The proposed model is quite straightforward
for the vibrational analysis of the curved structures. Moreover, the chaotic motions of the
fluid conveying carbon nanotube rested on a Winkler and Pasternak foundation are
studied. The bifurcation and time history diagrams, phase-plane trajectories and Poincaré
sections are presented to examine the dynamical behavior of carbon nanotubes. The
Galerkin approach in conjunction with the multiple time scales method is chosen to study the nonlinear vibrations of the proposed models. The effects of different parameters on the primary and secondary resonant cases and also the nonlinear and linear frequencies of CNTs are examined.


title: Comparison of the force and torque transfer for different cam profiles

subject:
Cam-follower
Force
Torque
Load cell
Experiment

abstract: This study presents static load and torque distribution measurements in groove cams for sinusoidal and cycloidal cam profiles. In this thesis, two different designs and apparatuses were developed and built for the static force and torque measurements in cam-follower systems. It was shown that for the constant load applied to the groove cams, the peak value of the cycloidal cam's average torque was nearly 50% higher than the peak value of the sinusoidal cam. It was also observed that for the constant torque applied to the groove cams, the peak value of the force experienced by the follower of the cycloidal cam was nearly 40% higher than the peak value of the sinusoidal cam. As a result of this thesis, cycloidal cams can be considered as advantageous compared to sinusoidal cams for having the tendency to produce larger shaft torque for the same external load.


title: Learning-based adaptive design for dynamic spectrum access in cognitive radio networks.

contributor:
Dong, Min
Grami, Ali

subject:
Dynamic spectrum access (DSA)
Access policies
Cognitive radio networks
Auction-based formulation
Decentralized multi-armed bandit (DMAB)
Online learning

abstract:
This thesis is concerned with dynamic spectrum access in cognitive radio networks.
The main objective is designing online learning and access policies which maximize
the total throughput of the secondary users in a cognitive radio network. As the first
approach, we consider the auction-based formulation in design of dynamic spectrum
access mechanisms where it is assumed that primary channels are heterogeneous with
distinct availability statistics unknown to each secondary user (SU). Considering this
approach, we first apply a unit demand (UD) auction which is called DGS (Demange-
Gale-Sotomayor) auction. Applying the DGS auction, we explore the instantaneous
link condition of each SU for its throughput maximization. To tackle the issues of this
UD auction, we propose a learning-based unit demand (LBUD) auction. Our proposed
auction mechanism incorporates a distributed learning of the primary channels
into the auction mechanism to explore both primary channel availability statistics
and instantaneous link gains of the SUs for their throughput maximization. This new
mechanism substantially improves the communication overhead and also the SUs’
throughputs where the primary channels have dissimilar availability statistics. The
proposed LBUD auction preserves the strong property of the UD auction, i.e., it is
dominant strategy incentive compatible. To improve convergence speed of the iterative
procedure used in the auction, we further propose an adaptive price increment
algorithm. Simulation results show the effectiveness of the proposed LBUD auction
mechanism in terms of the throughput gain.

As our second approach, we model the problem of designing decentralized dynamic
spectrum access policies as a decentralized multi-armed bandit(DMAB) problem.
Using DMAB formulation, we first propose a truly decentralized online learning
and access policy where in addition to channel availability statistics, the secondary
user population is also assumed to be unknown to the SUs. To reduce collision events
at different learning stages, we then improve an existing access policy by exploiting a
”perceived population” by each secondary user. We also develop a distributed learning
and access policy which is effective in a wide range of primary channel conditions.
As our last approach, we investigate designing of a decentralized online learning
and channel access in a cognitive radio network with M secondary users. We formulate
the distributed channel selection problem in a cognitive network as a strategic
game which is proved to be an exact potential game. Applying stochastic learning
automata, we propose an adaptive decentralized access policy where each SU probabilistically
selects one of the M-best channels to access. Based on collision events, we
update the channel selection probability. In our proposed adaptive policy, two underlying
distributed learning algorithms are utilized in parallel: i) Learning from sensing
history on the primary channel availability, and ii) Learning from collision history on
channel selections among SUs to avoid further collision. Simulation results show the
effectiveness of our proposed adaptive policy in various distributions of mean channel
availabilities across primary channels, as compared with other existing policies.

abstract: University of Ontario Institute of Technology


title: A real-time 12-lead electrocardiogram remote patient monitoring and analytics framework

subject:
Remote patient monitoring
Electrocardiogram
Telemedicine
Cardiovascular diseases
Real-time streaming

abstract: This work presents XBeats: A machine learning-based framework for real-time electrocardiogram monitoring and analysis that uses edge computing and data analytics for early anomaly detection. The framework encompasses a data acquisition ECG patch with 12 leads to collect heart signals, perform on-chip processing, and transmit the data to healthcare providers in real-time for further analysis. The ECG patch provides a dynamically configurable selection of the active ECG leads for transmission to the backend monitoring system. The selection ranges from a single ECG lead to a complete 12-lead ECG testing configuration. XBeats implements a lightweight binary classifier for early anomaly detection to reduce the time to action should abnormal heart conditions occur. This initial detection phase is performed on an edge node and alerts can be configured to notify designated healthcare providers. Further deep analysis can be performed on the full-fidelity 12-lead data sent to the backend. A fully functional prototype of the XBeats is implemented to demonstrate the feasibility and usability of the proposed system. XBeats can achieve up to 95.30% detection accuracy for abnormal conditions while maintaining a high data acquisition rate of up to 480 samples per second. Besides a systematic energy consumption profiling criteria is provided for evaluating participating hardware components in the XBeats ECG patch. We isolate each hardware component to find power-intensive processes, discover energy consumption patterns, and measure voltage, current, power, and energy consumption for a given period. The proposed optimization techniques demonstrate significant improvements to the hardware components. The results show that optimizing the data acquisition process saves 8.2% compared to the original power consumption and 1.62% in data transmission over BLE, thus extending the lifetime of the device. Lastly, we optimize the data logging operation to save 54% of data initially written to an external drive. Moreover, the analytical results of the energy consumption profile show that the ECG patch provides up to 37 hours of continuous 12-lead ECG acquisition.


title: Multisensory integration in subclinical neck pain

subject:
Multisensory integration
Subclinical neck pain
Response time
Two-alternative forced-choice

abstract:
Subclinical neck pain (SCNP) is recurrent neck pain marked by painful “flare-ups” and minimal to no pain between flare-ups. It is associated with altered proprioception, slower mental rotation response times, and altered sensorimotor integration, leading to the possibility that multisensory integration is also affected. Effective multisensory integration is important for many tasks at home and at work, making it important to know if it is altered in SCNP individuals, and whether any changes persist over time. A pilot study used a temporal order judgement task to see if SCNP affected multisensory integration. This study revealed many technical challenges due to aspects such as timing delays of the equipment used to present the stimuli. In the second experiment, a two-alternative forced-choice discrimination task was used to test for multisensory differences, specifically whether SCNP individuals have altered response times vs healthy controls, and the consistency of results over time. Response times were recorded at baseline and week 4. A two-way mixed ANOVA Indicated that auditory response times improved over time (p = 0.050) with no group differences. The SCNP group was slower at both visual and multisensory tasks (p = 0.046, p = 0.020, respectively), with no change for either group over 4 weeks, suggesting that these two stimuli are stable measures to use in future SCNP studies.
multisensory integration, audio, visual, tactile, subclinical neck pain, response time, two-alternative forced-choice discrimination, temporal order judgement.


title: Supporting student success with machine learning and visual analytics

subject:
Visual analytics
Machine learning
Student retention
Education
Predictive analytics

abstract: Post secondary institutions have a wealth of student data at their disposal. This data has recently been used to explore a problem that has been prevalent in the education domain for decades. Student retention is a complex issue that researchers are attempting to address using machine learning. This thesis describes our attempt to use academic data from Ontario Tech University to predict the likelihood of a student withdrawing from the university after their upcoming semester. We used academic data collected between 2007 and 2011 to train a random forest model that predicts whether or not a student will dropout. Finally, we used the confidence level of the model’s prediction to represent a students “likelihood of success”, which is displayed on a beeswarm plot as part of an application intended for use by academic advisors.


title: An energy-efficient periodic resource model for cyber-physical systems By Suzanne Elashri

subject:
Cyber-physical systems
Periodic resource model
Energy consumption
Delay-tolerant tasks

abstract: Cyber-Physical Systems (CPS), especially real-time systems, are subject to time constraints that should be met for the applications to run properly. The schedulability of workloads can be analyzed by determining the supply and demand bound functions (sbf & dbf) when the minimum resource availability (sbf) can satisfy the maximum possible resource demand (dbf) of the workload under a specific scheduling algorithm during a given time interval. Typical real-time systems are insufficient resource reservation by over-provisioning resources when resource supply is always higher than the workload demand. Energy efficiency considerations are required for resource reservations in real-time systems when calculating the optimum processor speed to ensure that the supply of resources is no less than the workload demand during any time intervals. Therefore, we explore an energy-efficient Dynamic Speed Scaling technique for CPS to efficiently estimate resource reservation and efficiently reduce energy consumption.


title: A flexible, longitudinal and surrogate consent model: Consent of Infants for Neonatal Secondary-use research (CoINS) Model

subject:
Surrogate consent
Secondary use
Physiological data
Neonatal research

abstract: Documenting healthcare, along with technology enabling capture of streaming patient telemetry, can deliver large datasets offering opportunities to discover new insights primarily identified through retrospective secondary use research. Research involving health data requires consent of the subject patient or someone with the power to speak on that patient’s behalf. Flexible consent models that capture consent preferences while allowing updates as preferences change are needed. This research proposes and demonstrates one solution in a case study collecting surrogate consent from parents for the physiological data of infant inpatients in the Neonatal Intensive Care Unit (NICU) and attaching this consent as a wrapper controlling access to their data. 145 parents were approached and 134 provided consent: with 78 percent of infants consented during their first week of life. This research supports the contention that using a flexible consent approach enhances willingness to consent use of infant’s health data for secondary research purposes.


title: Recommendations in visual analytics using emotions : a mixed-initiative interaction approach

subject:
Affective computing
Information visualization
Recommendation system
Eye tracking
GSR

abstract: The thesis demonstrates an idea for helping users in visual analytic tasks by investigating some critical steps required for providing recommendations. The proposed model uses mixed-initiative interaction approach by detecting users’ negative emotions, caused by the visual analytic tasks, as a cue to generate useful guidance. For building a negative emotion detection classifier, I have created a dataset from 28 participants carrying out intentionally difficult visualization tasks and collected their emotional responses using multiple biosensors. I used this dataset to built a real-time emotion detection model which predicts mental state in every 4s. Next, the visualization tool uses the detected emotions to generate a recommendation and decide when to intervene. Additionally, the system also adapts intrusion level by analyzing long-term emotions, and decide the best way to show the help. Finally, I have concluded this work by discussing the design space of interventions for providing just-in-time assistance in visual analytics.


title: Robust controller design for active trailer steering systems of articulated vehicles using multi-objective optimization

subject:
Multi-objective optimization
Control systems
Active trailer steering systems
Gain scheduling controller
Articulated vehicles

abstract: This thesis presents and evaluates an approach to the robust controller design for active trailer steering (ATS) systems to increase the safety of articulated vehicles. By applying a multi-objective evolutionary algorithm (MOEA) to the design optimization of the robust ATS controller, a series of optimal gain values can be obtained in a single run. This allows for posteriori decision making along with flexibility to select appropriate gain for different operating conditions. The algorithm creates Pareto optimal gain values for various speeds, thereby resulting in the robust ATS controller with an optimized gain scheduling scheme. The research elucidates the advantages of multi-objective algorithms over mono-objective or single-objective algorithms. For the design optimization of the ATS controller, a benchmark investigation is conducted to select an effective algorithm from the multi-objective algorithms, including GDE3, NSGA-II, NSGA-III, SPEA2 and MOPSO. A modular framework is introduced for co-simulations conducted in the CarSim-Simulink/Matlab environment, with which the vehicle and controller parameters can be optimized. The method ensures that a robust ATS controller with optimized feedback control gains, as well as satisfaction of design criteria and constraints. This research proposes a framework to generate a multi-dimensional look-up table using the multi-objective evolutionary algorithm for a general dynamic system controlled by a feedback controller. The optimized look-up system can be used to improve the robustness of control systems in real-world applications.


title: Isolation and partial characterization of three members of the GGR-1 family in the parasitic nematode Haemonchus contortus

subject:
Haemonchus contortus
GGR-1
Cys-loop receptor
Acetylcholine
Electrophysiology

abstract: Haemonchus contortus is a blood sucking parasitic nematode that infects ruminant animals. These parasites are of significant economic importance as they are estimated to cost the agricultural industry billions of dollars each year in management. Reliance and overuse of drugs has resulted in resistance, and there is an urgent need for novel anti-parasitic drugs. Cys-loop ligand gated ion channels have been recognized as important invertebrate specific drug targets. However, specific targets must be identified and characterized prior to drug development. This thesis describes the identification and partial characterization of three ion channel subunits from the GGR-1 family – Hco-lgc-39, Hco-lgc-40, and Hco-ggr-2. The phylogenetic analysis conducted in this study revealed that these genes are widely conserved across several different parasitic nematodes. Two of these genes, lgc-39 and ggr-2, have not been previously characterized in another organism. Although lgc-40 has been previously investigated in C. elegans, the channel found in H. contortus was found to be similarly sensitive to choline and 18-fold more sensitive to acetylcholine. This increased sensitivity to acetylcholine could potentially indicate a different function in H. contortus. Pharmaceutical characterization of Hco-LGC-39, revealed that this protein subunit forms a homomeric channel that is responsive to acetylcholine, and to a higher degree, methacholine. A ligand for the Hco-GGR-2 homomeric channel has not yet been identified. Additionally, homology modelling of Hco-LGC-39 and Hco-LGC-40 provided further insight into receptor ligand interactions, and helped to identify several residues that may be important for ligand binding. This partial characterization of unique receptor subunits provides the beginning step for the production of novel anthelminthic drugs to combat the increasingly problematic parasite, H. contortus.


title: An analysis of the freedom of expression policy in higher education

subject:
Free speech
Higher education
Ontario
Empathy
Policy analysis

abstract: This study examines free speech policy in general and specifically the free speech policy at one institution of higher education in Ontario, Canada, in order to better understand the complex interconnectedness between human rights and freedom of expression. The detailed, rigorous analysis of free speech policy was guided by Pal’s (2014) policy analysis framework, which encourages investigations of the normative, legal, logical and empirical aspects of a policy. The normative policy aspects include basic values and ethical principals underlying free speech policy. Also included here are Rogers’ (1969, 1995) freedom to learn within the context of humanistic education theory. The legal aspects include an examination of human rights and legal rights in Canada and Ontario. Logical analysis considers the paradoxes such as the paradox of tolerance (e.g. Habermas, 2003). The empirical elements of this study include a survey of students at one university asking about free speech and empathy. Students were also invited to engage in a knowledge co-creation activity working in an online community. This policy analysis framework provided a comprehensive way to investigate free speech. One unique contribution of this research is its cross-disciplinary approach to existing fields such as policy, law, humanistic education and technology. It explored new hitherto less-investigated relationships of free speech with empathy. The findings of this study indicate that a cross-disciplinary approach provides a comprehensive lens to understand the complexities of free speech and to inform related education research and policy analysis.


title: Application-specific transfer learning over edge networks

subject:
Machine learning
Transfer learning
Embedded systems
Edge networks
Classification and regression

abstract: Transfer learning uses a profound labeled set of data from the source domain to deal with a similar problem for the target domain. Transfer learning provides accurate decision- making when insufficient data samples are available and when building a new prediction model takes more time and effort. This study explains comparative analysis of traditional machine learning techniques and transfer learning approaches over edge networks to enhance the performance and networking latency within discrete nodes. Edge networks are widely used to improve the efficiency and staging of any algorithm as the embedded systems focus on implementing some particular events based on the microprocessors and, at the same time, working on the least resources that result in having less power consumption. Moreover, we generated a hybrid-based transfer learning model to avoid negative transfer. This thesis uses two case studies: mushroom sales prediction and heart attack detection system.


title: Toward enhancement of evolutionary multi- and many-objective optimization: algorithms, performance metrics, and visualization techniques

contributor:
Rahnamayan, Shahryar
Martin, Miguel Vargas

subject:
Many-objective optimization
Visualization
Performance metrics
Hybrid optimization
Evolutionary computation

abstract:
In the last three decades, the focus of multi-criteria optimization has been solving problems containing two or three objectives. However, real-world problems generally involve multiple stakeholders and functionalities requiring relatively large number of objectives and decision variables to model these sophisticated problems. In the optimization field, multi-objective problems with four or more objectives are called many-objective problems. Although there are a number of highly successful multi-objective algorithms capable of solving complex two- or three-objective problems, the majority of these algorithms experience significant performance deterioration due-to an increase in the number of solutions required for approximating the entire Pareto-front and the loss of selection pressure required to move non-dominated candidate solutions towards the optimal Pareto-front. Moreover, as the number of objectives increases, visualization of the solution set becomes progressively challenging as well as the applicability of quantitative performance metrics capable of measuring the convergence and diversity of solution become computationally too expensive or unreliable.
This thesis explores the challenges associated with solving many-objective optimization problems and proposes novel algorithms, performance measures, and visualization techniques to mitigate these challenges. Firstly, three multi- and many-objective visualization techniques are proposed. These visualization techniques are capable of showing the convergence and distribution of solutions on the Pareto-optimal front, the distribution of solutions along each objective, and relationship among decision variables and objective function values. Secondly, two novel performance measures capable of assessing the distribution and spread of solutions along each objective are proposed. Thirdly, a new reference-based hybrid optimization framework is proposed to allow multiple optimization algorithms to work together to take advantage of their combined benefits. This framework is also capable of extracting a subset of well-distributed solutions from thousands of non-dominated solutions collected during the optimization process of several algorithms. Lastly, the proposed optimization algorithms, visualization techniques, and performance measures are applied to multi-objective renewable energy systems to assess their efficacy when dealing with real-world problems. Experimental results on widely used benchmark and real-world optimization problems indicate that the proposed optimization algorithms, visualization techniques, and performance measures can significantly enhance the solving and decision-making processes involved in multi- or many-objective optimization.


title: MAVIDS: an intelligent intrusion detection system for autonomous unmanned aerial vehicles

subject:
Unmanned aerial vehicle
Intrusion detection systems
Machine learning
Novelty detection
Cyber-physical systems

abstract: Unmanned Aerial Vehicles (UAVs) face a large threat landscape, being used in numerous industries in hostile environments while relying on wireless communication. As attacks against UAVs increase, an intelligent Intrusion Detection System (IDS) is needed to aid the UAV in identifying attacks. The UAV domain presents unique challenges for intelligent IDS development, primarily the variety of components, communication protocols, and dataset availability. A novelty-based approach to intrusion detection in UAVs is proposed by using one-class classifiers, exploiting the use of flight logs for training. The proposed technique is integrated into a fully developed IDS which operates onboard the UAV, allowing it to detect and mitigate attacks even when communication to the ground control station is lost. The approach shows promising results when faced with a number of common attacks, including macro averaged F1 scores of up to 90.57% and 94.3% for live GPS spoofing and jamming respectively.


title: Conductive Si doped metal oxide fuel cell catalyst supports: understanding the role of Si content

subject:
Metal oxide
Electrocatalyst support
Durability
Proton exchange membrane fuel cell

abstract: Current proton exchange membrane fuel cell (PEMFC) catalysts commonly use platinum supported on carbon (Pt/C) which is susceptible to corrosion, thus a highly conductive and stable Ti3O5 doped by Si (TOS) conductive metal oxide catalyst support is reported. The TOS support was optimized for 20 wt% Si and surface area. The support was studied under intensive electrochemical durability tests and exhibited impressive durability and stability, narrow band gap and high electronic conductivity. The TOS support was platinized (Pt/TOS) and possessed high stability under and electrochemical durability test while experiencing ca. 15% loss to the electrochemical surface area (ECSA) compared to the commercial Pt/C catalyst which decayed by 90%. The Pt/TOS catalyst maintained adequate electroactivity and stability toward the ORR and produced a maximum power density of 900 mW cm-2 compared to 850 mW cm-2 for Pt/C.


title: Development and initial testing of a virtual simulation training module to teach microtomy

subject:
Microtomy
Simulation-based education
Gamification
Justice
Simulation

abstract:
Background: Microtomy is a procedure that medical laboratory technologists (MLTs) use to cut tissue samples. The aim of this thesis is to use the think-aloud protocol to develop a virtual simulation training module for students to learn microtomy.
Methods: A think-aloud protocol was conducted with an MLT expert to generate the steps of the microtomy procedure. Eight experts rated the criticalness and provided feedback on the steps. Once the module was developed, nine undergraduate students completed the module and provide feedback.
Results: The think-aloud protocol generated 10 steps for the microtomy procedure and experts concluded that all ten steps are critical. Students who completed the module provided a positive response and considered the module as a useful tool to practice microtomy.
Conclusions: The 10 steps of the microtomy procedure have been validated by MLT experts. Students completed the virtual simulation training module and viewed it as a user-friendly tool for learners of the medical laboratory sciences program.


title: The analysis of the entomological and chemical decomposition of human remains to ultimately assess the viability of the domestic pig as a substitute in forensic applications

subject:
Forensic entomology
Human decomposition
Volatile organic compounds
Postmortem interval

abstract: Death investigations often rely on the minimum post mortem interval (minPMI) estimations provided by forensic entomologists. The models accepted by courts in Canada are not based on research involving humans but rather on a human substitute, the domestic pig. However, now that facilities for human decomposition research are opening, we are faced with the prospect that pigs may not be so similar to humans as originally thought. The purpose of this research is to analyze the entomological and chemical decomposition of human and pig remains to determine if the domestic pig is an appropriate substitute for humans in research applied to minPMI estimations. Two human (n=4, n=2) and one pig (n=2) study were performed in Sydney, Australia, while three pig (n=3, n=2, n=3) studies were performed in Oshawa, Ontario. The environmental conditions were monitored as well as the accumulated degree days (ADD), rates of decomposition, primary dipteran colonizers, and volatile organic compound (VOC) production. Domestic pigs in Oshawa, Ontario, had rates of decomposition that were highly alike. Rates of insect colonization were rapid, with little to no delay. The production of 5 known apneumones showed no significant difference (p < 0.05) between pigs. Human decomposition in Sydney yielded results with varied rates of decomposition and colonization – some with long pre-colonization intervals (Pre-CIs), which affected the rate of decomposition. It was noted that the donors with long Pre-CIs were likely to have been taking strong peri-mortem antibiotics due to their antemortem health conditions. These antibiotics could have affected the donor’s microbiome, killing the beneficial bacteria that produce apneumones. The domestic pigs observed in Sydney showed decompositions, colonizations and VOC productions more similar to the pigs in Ontario than to the humans in Sydney. Humans live differently than domestic pigs with varying diets, habits, body types, and medications that can influence their decomposition and colonization after death. Since this cannot be said for the domestic pig, it is recommended that the researching community aim to shift future research to human donors so that the data collected can be applied to human death investigations while considering comorbidities and how it affects insect colonization.


title: StoryTIME: development of a tangible interface for storytelling

subject:
Augmented reality
Tangible interface
Projection mapping

abstract: The production of 3D digital animated sequences is an iterative process where ideas are scrutinized by members of the production team until they are finalized. Production teams are comprised of many individuals with varying levels of expertise in a broad spectrum of disciplines such as screen writing, animating and directing. It is imperative that everyone involved understands the development tasks for the production. To facilitate the communication of ideas, the prototyping process typically begins with the development of a storyboard that is then turned into a 3D previsualization. This process requires specialized training to be effective. This thesis presents StoryTIME, a system designed to simplify the storyboarding and digitalization process by leveraging tangible interfaces and projected augmented reality. The presented system works by capturing and recording the motion of physical props such as small toys and figurines which are then applied to a virtual counterpart. We discuss the design and development of the system followed by a user study that investigates its effectiveness with respect to traditional animation prototyping systems.


title: Coded aperture imaging application in one-sided imaging of visually obscured objects

contributor:
Waller, Ed
Nokleby, Scott

subject:
Coded aperture imaging
Backscattered x-rays
One-sided imaging
Concealed objects

abstract:
The physical properties of visible light and its interaction with matter create
obstructions the human eye cannot explore. High energy radiation has been
used as an alternative to visible light to penetrate these concealed regions
and reveal their contents. However, traditional imaging techniques require a
two-sided apparatus with a radiation source and a detector on opposite sides
of the concealed object.
One-sided imaging of concealed objects is made possible by a technique
called backscatter imaging, utilizing high energy radiation. However, the
signal produced by backscatter imaging is inherently weak, which makes in-
terpretation di cult. One of the most promising techniques for recovering
the weak signal is the coding and decoding provided by Coded Aperture
Imaging (CAI).
The purpose of this study was to create and test a coded aperture imaging
system using backscattered x-rays. This would enable one-sided imaging of
concealed objects and demonstrate whether a portable imaging system was
feasible. The results obtained from conducting a computer simulation, visi-
ble light experiments, and x-ray experiments proved that the process works,
however, the x-ray
ux levels required were too high for a portable system,
based upon the current equipment available at UOIT.

abstract: University of Ontario Institute of Technology


title: Monte-Carlo-simulation-based performance analysis of the heat transfer process in nuclear-based hydrogen production based on Cu-Cl Cycle.

subject:
Monte-Carlo simulation
Performance analysis

abstract: As a crucial step in nuclear-based hydrogen production based on Cu-Cl cycle, the performance analysis of heat transfer process is of paramount importance. However, as a newly built system, the major obstacle of applying standard performance analysis to the heat transfer process is the sparse data. In this thesis, the methodology of Monte-Carlo Simulation-based (MCS-based) performance analysis is developed, and it is shown that this method can be used to deal effectively with the problems caused by sparse data in the heat transfer process. This method expanded the database successfully and carried out the Monte-Carlo simulation through expanded database. The details of the heat transfer process in a nuclear-based hydrogen production based on a four-step Cu-Cl cycle is firstly listed and discussed. Afterwards, the modelling of the MCS-based performance analysis of heat transfer process is proposed and explained step by step. The confidence interval of the simulation results is demonstrated since the variations in results is a major issue for any performance analysis based on simulations. The final result indicated that the MCS-based performance analysis is a reasonable performance analysis method that can be used to evaluate the performance of the heat transfer process in the nuclear-based hydrogen production based on Cu-Cl cycle through sparse data.


title: Development and pilot of a survey to build capacity for examining interactions of constraints to sport participation among adolescent girls

subject:
Sport
Interactions
Survey development
Newell’s model

abstract: Sport participation (SP) declines among girls during adolescence, and though many constraints to SP have been identified, it is not known whether or how they interact. The purpose of this thesis was to develop a survey which collects data on constraints to SP, and pilot it on adolescent girls residing in Durham Region, Ontario. A comprehensive list of constraints was generated from the literature. The research was guided by Newell’s model of constraints (individual, environmental and task), and the Developmental Assets Profile (DAP). An online survey was developed and validated via an expert panel. The survey was piloted on a sample of adolescent girls (n=97, mean age= 15.5 years). Survey data revealed good reliability (Cronbach’s α=0.897). Recommendations for larger scale implementations are discussed in terms of refining a sampling strategy, resolving issues with survey administration, and refining analytical techniques.


title: Design of rectifier power supplies for Thermal Energy Storage System

subject:
Thermal Energy Storage System (TESS)
Battery Energy Storage system (BESS)
Asymmetric converter
Symmetric converter

abstract: Energy storage systems have been brought to focus as means to reduce the high fluctuation in the production side and facilitate integration of renewable energy sources. This work is focused on investigating design and utilizing of cost-effective Thermal Energy Storage System (TESS) which has longer life-time as an alternative to Battery Energy Storage System. Both thermal and electrical design aspects are investigated in this work. For thermal part; detailed analysis of electrical properties of the heating element (i.e. graphite) is conducted to design the heating element used to heat up the storage material (i.e. molten salt). For electrical part; asymmetric and symmetric power electronic rectifier are investigated and compared with low frequency modulation and pulse width modulation techniques, based on their power factor (PF) and total harmonic distortion (THD). Finally, direct output voltage control and cascaded current voltage control are implemented and compared.


title: Development and experimental investigation of new self-can cooling systems

subject: Self-cooling Can Analytical Numerical Optimization

abstract:
In this thesis, two conceptual self-cooling beverage can designs are proposed. The methods of cooling are validated experimentally and certain parameters of interested are obtained for an analytical and numerical study of the conceptual designs. Optimization of the can geometry for heat transfer rate, volume of beverage, and total amount of cooling is performed.
Experiments are carried out using experimental test systems that evaluate the validity of two specific cooling methods. First method of cooling uses ammonia throttling followed by desiccant salt adsorption. The results show that there is satisfactory cooling for 300 ml of water in 3 minutes. The second method uses an endothermic reaction between ammonium thiocyanate and barium octahydrate as a cooling method. The results show that this method is also a valid cooling method.
The experimental work provides key parameters of interest for the analytical and numerical study of the proposed conceptual self-cooling can designs. The numerical study is conducted using computational fluid dynamics and heat transfer modeling. The goal of this study is to determine the best aspect ratio for the cooling vessel inside the beverage can, and to determine the effects of ambient temperature on the performance of the system. The results show that the best performing aspect ratio is aspect ratio 4. Aspect ratio 4 is the thinnest and longest cooling vessel and provides the best heat transfer performance. Ambient temperature does not significantly change the final temperature of the beverage at the end of 3 minutes.
A cooling effectiveness study is conducted to evaluate the performance of the self-cooling beverage can. The study only looks at the ammonia expansion design. The best performance in terms of cooling effectiveness is achieved when using aspect ratio 4 at an ambient temperature of 35°C. The cooling effectiveness for this specific case is 0.834 for energy and 0.772 for exergy, respectively.
An optimization study of the self-cooling beverage can geometry is conducted. The objectives are to minimize cooling time, maximize volume of beverage, and maximize cooling effectiveness. The non-dominating optimal solutions are presented in Pareto front graphs. The results of this study provide a highly effective tool needed to make a decision on which dimensions to use in a final design of a self-cooling beverage can.