title: Harmonic emissions assessment for common DC and AC electric vehicle charging station architectures

subject:
Electric grid
Electric vehicle (EV)
FCS
Power quality
Harmonics

abstract:
Future transportation needs are going to be met by Electric Vehicles (EVs) because of global pollution by oil-based vehicles and climate change. In order to meet the charging demand and range anxiety of EV users, Fast Charging Stations (FCS) are required. As these FCS are grid-connected, they are going to be a new non-linear load for the host utility, which will impact its Power Quality (PQ).
In this thesis, Common DC and AC bus (CDCB and CACB) architectures for grid-connected FCS are examined. For both architectures, two-level Voltage Source Converter (VSC) is used to connect the EV FCS to the grid, and further cascaded DC-DC converters are used for voltage regulation at the charger end. The Unit Template (UTC) and dq-SRF control methods are implemented for switching control of the VSC. The Constant Current-Constant Voltage (CC-CV) method is used for the control of DC-DC converters. The simulations are run in MATLAB/Simulink®. The following studies are carried out:
•	Comparison of CDCB & CACB architectures by varying load and transformer connections: - results show that CDCB architecture gives better performance in terms of charging and PQ, and the star-delta configuration of Distribution Transformer (DT) connections provides lower harmonics.
•	Comparison of two control strategies for the VSC using UTC and dq-SRF control strategies: - results show that UTC strategy performs better than dq-SRF method for control and operation of VSC.
•	Studying the impact of varying X/R ratio and MVASC: - results show that MVASC and X/R ratio has significant impact on a weak-grid operation connected with the FCS.
•	Studying the system with and without PV-panel: - results show that inclusion of PV-panel increases the reliability and efficiency of the system. There is small increase in THDV and THDI due to inclusion of PV-panel, but is as per the IEEE-519 standards.
•	Comparison of a Conventional-Capacitor (CC) with Super-Capacitor (SC) for the common DC bus: - results show that SC escalates the charging speed with fewer harmonics.
•	Comparison of two architectures in Vehicle to Grid (V2G) mode: - results show low harmonic content and better State of Discharge (SoD) with CDCB architecture.


title: Sedentary time and hospitalization in Canada's middle-aged and older adults

subject:
Sedentary time
Hospitalization
Older adults
Falls
Physical function

abstract: Sedentary Time (ST) is a widespread behaviour in all age groups, especially in older adults. It is associated with chronic conditions, falls and poor physical function. Our purpose was to investigate the association between ST and hospitalization in middle-aged and older adults, considering falls and physical function. Canadian Longitudinal Study on Aging data on physical function, self-reported ST, and hospitalization were used in logistic regression models. Falls-related hospitalization was negatively associated with ST in middle-aged females such that higher ST was associated with lower odds of hospitalization. Emergency department visits were positively associated with ST in middle-aged males, while higher time in the Timed Up and Go test (worst fitness) was positively associated with all types of hospitalization in different groups. The associations between ST and hospitalization imply the need to investigate sex-specific recommendations in regards to falls and hospitalization prevention. Future intervention research is required.

abstract: University of Ontario Institute of Technology


title: Impact of neck muscle fatigue on upper limb sensorimotor integration

subject:
Somatosensory Evoked Potentials (SEPs)
Transcranial Magnetic Stimulation (TMS)
Motor acquisition
Sensorimotor Integration (SMI)
Proprioception

abstract:
Neck muscles have a high density of sensory receptors which project to the central nervous system, and have important role in sensory motor integration (SMI). The cerebellum is important for SMI and it is known to undergo neuroplastic changes in response to performing a novel motor acquisition task. Alterations in neck sensory input impacts motor output to upper limb muscles, cerebellar disinhibition, and performance accuracy in response to novel motor acquisition. Despite this, the impact of cervical extensor muscle (CEM) fatigue on cerebellar-motor cortex plasticity and SMI pathways in response to a novel motor acquisition task has not been yet investigated.
Study one used short latency somatosensory evoked potentials (SEPs) to investigate the differential effects of CEM fatigue on motor learning and retention; and on sensorimotor processing from distal hand muscles. CEM fatigue impaired upper limb motor learning performance in conjunction with differential changes in SEP peak amplitudes related to SMI. Study two used a paired pulse cerebellar-motor cortex transcranial magnetic stimulation (TMS) technique to determine whether CEM fatigue alters cerebellar disinhibition in response to novel motor skill acquisition. Neck fatigue led to a lessened capacity for cerebellar disinhibition coupled with diminished motor learning relative to a control group. Study three used an eye-hand tracking protocol to investigate the effect of CEM fatigue on accuracy of pointing to both visual and hidden targets. CEM fatigue reduced the accuracy of upper limb tracking to a hidden target. Study four used short- and medium-latency SEPs to determine the impact of CEM fatigue on motor performance accuracy and retention of proximal upper limb muscles, as well as neural processing changes in response to novel motor acquisition using proximal upper limbs muscles. CEM fatigue had minimal impact on proximal upper-limb motor performance accuracy, but lead to differential changes in both short- and medium- latency SEP peak amplitudes related to SMI.
Overall, this thesis suggesting that SMI areas including the cerebellum are impacted by CEM fatigue, likely because the altered afferent input from the neck due to fatigue alters body schema, impacting awareness of upper limb position sense, resulting in decreased upper limb performance accuracy.


title: Modeling and vibration analysis of a rocking–mass gyroscope system

subject:
Mechanical vibrations
Gyroscopes
Mathematical modeling
Gyroscope systems

abstract: Rocking-mass gyroscope consists of an assembly of four cantilever beams with a rigid mass attached to them in the middle subjected to base rotations.  Due to the gyroscope effect, the beams undergo coupled flexural-torsional vibrations.  The main goal of the research is to develop an accurate model of such a system and along this line a detailed mathematical modeling of the gyroscope is developed.  The equations of motion clearly show the presence of the gyroscopic couplings in all cantilever beams.  A computer simulation model in its most general form has been developed, to analyze the effectiveness of this type of gyroscope.


title: Determining the impact of carrion decomposition on soil microbial activity levels and community composition.

contributor:
Forbes, Shari
Kirkwood, Andrea

subject:
Taphonomy
Soil microbiology
Decomposition
FAME profiling
Illumina sequencing

abstract: The ubiquitous nature of microorganisms and their specificity to certain locations make them potentially useful for forensic investigators. Advances in microbial profiling techniques have made it possible to compare microbial community profiles obtained from evidence or crime scenes to individuals and vice versa. Profiling microbial communities associated with cadaver decomposition may provide useful information concerning post-mortem intervals and aid in the identification of clandestine graves. Four experiments using pigs as human decomposition analogues were performed over the course of 2011 and 2012 in southern Ontario to document changes in soil microbiology following decomposition. Studies were conducted in the spring and summer to document the effect of environmental conditions on the decomposition process and subsequent changes in gravesoil microbiology. Microbial activity was measured using a fluorescein diacetate assay as a preliminary indicator of changes within the soil microbial population. Both decreases and increases in microbial activity were observed throughout each decomposition experiment indicating that the microbial response to decomposition is complex. It is believed that environmental conditions and decomposition rates play a role in determining how taphonomic events affect soil microbial activity. Fatty acid methyl esters (FAME) profiling was used document community level changes throughout decomposition. Shifts in FAMEs profiles were brought on by the onset of active decay and persisted through to the dry remains stage. The fatty acids 3OH 12:0, 12:0, 16:0 and 18:0 were frequently found in higher amounts in gravesoils and may prove useful as markers of cadaver decomposition. Metagenomic profiles of soil microbial communities were obtained using Illumina® sequencing. Decomposition was associated with changes in microbial community composition. This allowed gravesoil samples to be differentiated from control samples for an extended period of time. Bacteria responsible for the shift in microbial profiles are those commonly associated with cadaver decomposition. Both sets of soil profiles indicated that weather had an effect on microbial community composition. Results highlight the need to document natural changes in microbial communities over seasons and years to establish normal microbial patterns to effectively use soil microbial profiles as post-mortem interval or clandestine grave indicators.


title: Deep learning for islanding detection of grid-connected photovoltaic systems

subject:
Convolutional neural networks
Deep learning
Passive islanding detection
Photovoltaic systems
Smart distribution systems

abstract: Over the past decade, the integration of renewable-based distribution energy resources within the smart distribution system has been steadily growing. Despite the numerous advantages of integrating these renewable energy resources in reducing the greenhouse gas emissions and releasing the transmission line capacity, there are many operational challenges involving the protection when considering the unintentional islanding of these resources. Typically, when faults occur, an island or multiple islands may be formed throughout the electrical power distribution system. When the island includes one or more distributed energy resource, there is usually a serious potential hazard for the working personnel and hence the IEEE Standard 1547 recommends the distributed generation to cease to supply within 2 seconds of the formation of the island. Thus, there is a need for detecting the island and disconnecting the distributed generation within two seconds to fully comply with the IEEE Standard. In the literature, several methods for islanding detection have been proposed, which can be classified as communication-based, active or passive methods. The communication-based methods are expensive to implement while the active methods typically inject harmonic distortion into the distribution system to detect the island, which will lead to power quality degradation. On the other hand, the passive methods are preferred over other detection methods because they are inexpensive to implement and they do not affect the system power quality. The passive methods rely on identifying the islanding features in the local measurement of the voltage and current signals, which needs to be fed to the machine learning algorithms that have been proposed in the literature. However, identifying such features a priori is a very complex task in particular when considering inverter-based renewable energy resources. The work in this thesis uses deep learning to discover the features of the islanding as part of the classification process rather than identifying the features a priori as in the previous work and hence enhancing the capability of the passive methods. The results of testing the proposed passive islanding approach show an outstanding performance of the proposed method in islanding detection in grid-connected photovoltaic system. The proposed method utilized 31 features generated from 46 different cases to classify and detect the islanding. The proposed method succeeded in detecting islanding with a high accuracy of 98.1% and a rapid detection time of 0.28 second.


title: Novel electrode materials and advanced electrochemical diagnostics for electrochromic devices

contributor:
Zenkina, Olena V.
Easton, E. Bradley

subject:
Electrochromic
Durability
Electrode
Impedance spectroscopy
Degradation

abstract: Electrochromic materials (ECMs) are a class of “smart” materials used in a variety of applications due to the ability to alter their optical properties with the application of a potential. For these applications, ECMs are fashioned into electrochromic devices (ECDs). However, commercialization of ECDs are limited due to challenges with cyclic stability and optical durability. Commonly, it is seen that ECM development is vastly investigated, while insight into the overall ECD architecture is limited. In this work, the effect of the counter electrode (CE) and operating potentials were investigated using an Fe (II) terpyridine based complex as the ECM. From this, it was found that by improving the charge-storage properties at the CE and limiting the potential window used, ECD degradation could be minimized. Furthermore, by employing these modifications it was found that the lifetime of these ECDs were able to undergo months of constant cycling, as opposed to days, with further improvement to their optical properties.


title: Optimal resource sharing and spectrum leasing in energy efficient relay-assisted networks

subject:
Relay networks
Resource sharing
Power allocation
Cooperative networks
Energy harvesting

abstract: Assuming a bidirectional relay assisted network, we first study the problem of optimal resource sharing between two transceiver pairs. One of the pairs, referred to as the primary pair, owns the spectral resources while the other pair, called the secondary pair, is considered to own the relay infrastructure. Assuming amplify-and-forward relaying scheme and aiming to establish a cooperation between the two networks, we study three different design problems in a single carrier scenario. In the first approach we maximize the smaller of the secondary transceiver rates subject to two separate constraints on the total powers consumed in the primary and the secondary networks while providing a minimum data rate to the primary pair. In the second approach, we replace the per network power constraint by a constraint on the average total power consumed in both networks. The third approach combines the two aforementioned methods to materialize spectrum leasing and sharing for the case when the primary network is active with a certain probability. Then we investigate two different design approaches to the multi-carrier scenario. The first approach relies on maximizing the secondary network average sum-rate subject to two spectral power masks for the two networks while providing a minimum sum-rate to the primary pair in a multi-relay scenario. In the second approach, we replace the spectral power mask for each network by a constraint on the total power consumed in that network. Different from the previous studies, we further investigate the resource allocation problem between several energy harvesting relay nodes such that a unidirectional communication link is established between a pair of users and the harvested energy is optimally allocated between the relays such that the overall throughput of the network is maximized. Assuming the availability of full knowledge of channel state information and that of the energy packets, we maximize the throughput of the network under two sets of constraints on the status of the battery. We then consider the problem of maximizing the average throughput of the system, for the case when only the statistics of the channels are available.


title: Computational and laboratory investigations of a model of blood droplet flight for forensic applications

subject:
Stereoscopic 3D
Depth cues
Game design
User experience
Engagement

abstract:
Game developers strive to maximize immersion and engagement,
to emotionally involve the audience in their material. One technique
used to increase engagement is the development of new technologies,
such as Stereoscopic 3D. Stereoscopic 3D (S3D) creates the impression
of depth (stereopsis) in  at images by providing additional binocular
depth cues, such as convergence and binocular disparity. In this thesis,
we explore the e ects that S3D has on the player experience in an
attempt to uncover design methodologies that can help game developers
develop more e ective content. Three experiments were designed
and conducted to examine the e ects S3D has on player experience and
game design: i) Engagement in Stereoscopic 3D Games, ii) S3D Depth-
Axis Interaction for Video Games: Performance and Engagement, iii)
Depth Representation and Player Performance with Depth-Axis Interactivity.
We hypothesized that S3D technology would increase immersion
and engagement, and new mechanics that exploit the depth axis would
be e ective.
The results of these studies suggest that S3D does not increase
user engagement, and is consistent with prior research that suggest
the impact of S3D is dependent on the game. They also demonstrate
that developers can design unique experiences in stereoscopic 3D, but
there may be additional ways to represent depth. The results suggest
developers need to adjust the di culty of their game when including
stereoscopic 3D, depending on the interactions of their game. It is our
recommendation that developers continue to explore the a ordances offered
by stereoscopic 3D to create unique experiences, but its inclusion
is dependent on their speci c game.


title: Anodic alcohol fuel cell reactions at platinum active sites on doped metal oxide supports

subject:
Doped metal oxides
Electrocatalyst
Alcohol oxidation
Ethanol sensor
Electrochemical impedance spectroscopy

abstract: Fuel cells produce electrical energy via chemical reactions, which take place on the carbon supported platinum catalyst (Pt/C). As attractive as these devices may seem, their practicality is often limited by the functionality of the carbon support, which can be prone to corrosion. To limit the corrosion associated with a carbon-based catalyst, metal oxide supports are an area of interest as they display high stability in the harsh conditions associated with fuel cell operations. In this work, the employment of various doped metal oxide supports; silicon & molybdenum doped titanium oxide (TOMS), silicon doped titanium oxide (TOS), and silicon doped niobium oxide (NbOS) were investigated to replace carbon as a supporting material in alcohol fuel cells. In an alkaline environment, Pt/TOMS displayed faster kinetics and less poisoning during the methanol and ethanol oxidation reactions compared to the commercial Pt/C. When compared in an acidic ethanol and methanol oxidation, Pt/TOS and Pt/NbOS exhibit smaller activation energies than Pt/C, however, only Pt/NbOS produces smaller charge transfer resistances and higher peak oxidation currents. These studies highlight the promise of replacing the carbonaceous material presently found in fuel cells with metal oxide, or doped metal oxide, materials.


title: The impact of assisted dying on suicidality: a synthetic control analysis of population suicide rates

contributor:
Gamble, Brenda
Rudoler, David

subject:
Assisted dying
Synthetic control method
Suicide rate
Suicide contagion
Belgium

abstract: Adoption of assisted dying is growing, but one argument against these policies is that they cause a suicide contagion, thus increasing suicides. Evidence for the assisted dying-suicide link does not currently exist, and in general, research is scarce. I add to this body of literature to help stakeholders understand the consequences of such policies. I performed a time series study to determine how suicide rates changed in Belgium after assisted dying was introduced in 2002. The synthetic control method was chosen for the analysis, and additional European nations were included as placebos. The results show no change in suicide rates following the assisted dying policy change. A comparison of MSPE ratios with placebo countries also suggest statistical insignificance (p = 0.29). I conclude that there is no evidence that Belgium’s assisted dying policy is associated with a change in suicide rates or a suicide contagion.


title: Non-precious metal catalysts prepared by chemical functionalization of carbon surfaces.

contributor:
Easton, Brad
MacLean, Brian J.

subject:
Fuel cells
NPMC
ORR
Diazonium

abstract:
New sources of power are of great interest as attempts to make smaller, more convenient and environmentally friendly sources are being investigated. Hydrogen fuel cells are a way to combine both an effective method of power supply, converting chemical energy into electrical energy directly, and a way to employ clean energy. Fuel cells involve the use of platinum (Pt) as a catalyst, for both the oxygen reduction and hydrogen oxidation reactions, which is both rare and expensive. As such, there is significant ongoing research towards the discovery of non-precious metal catalysts (NPMC) with activity comparable to that of Pt.
The Fe-N/C catalyst system is a promising alternative, though the exact structure of the active catalytic site is still debated. Active catalysts are typically formed by high temperature (600 – 1000°C) pyrolysis in an ammonia atmosphere of a carbon with adsorbed iron on the surface. Our approach to these catalysts employs surface chemical methods to more systematically synthesize the active site in order to better relate structure and activity. The current nitrogen compound of interest is 5,6-diamino-1,10-phenanthroline (aphen) which was attached to a carbon support (Black Pearls 2000 or Ketjen Black EC600JD) using a diazonium coupling reaction. This a chemisorption process, as opposed to physisorption one, that allows for a clearer model of attachment of the aphen molecule.
In order to understand the effects of the precursor and the metal on active site density and activity many synthetic parameters were varied and measurements were taken at each step of the process. Aphen loading was investigated by preparing a series of samples with increasing ratios of aphen to Black Pearls 2000 and Ketjen Black EC600JD. Iron uptake was also explored by using two different iron salts; iron(III) chloride and iron(II) acetate. An alternate carbon support and synthetic route was also explored using graphene oxide in a glycerol reflux to mimic reactions commonly used to make organometallic compounds.
Overall it was found that the Black Pearls 2000 outperformed the Ketjen Black EC600JD samples at all ratios. An optimal heat treatment, ink loading and ratio of aphen to carbon black pearls was determined for these catalyst materials. It was also observed that using iron(III) chloride for the iron uptake step produced the most active catalyst. Electrochemical and structural measurements indicate that the success of the diazonium coupling reaction and graphitization during heat treatment are essential to the synthesis of active materials.


title: Professors’ views on mental health nursing education in the baccalaureate nursing programs of Ontario: a grounded theory approach

subject:
Mental health
Psychiatric
Nursing
Education

abstract: According to the Canadian Nurses’ Association (2005), mental health (MH) nursing is currently undervalued in the nursing profession. The Education Committee of the Canadian Federation of Mental Health Nurses (CFMHN) (2009) reports that the length of MH theory and practicum varies enormously in the undergraduate nursing programs of Ontario and across the country. Interviews with 19 nursing professors representing programs with different MH components show a variation in their opinions about topics such as the degree of importance of a mandatory stand-alone MH component, whether MH nursing education should be students’ or professors’ responsibility, how professors relate themselves to the MH component, and their familiarity with and assessment of their program’s MH education. It remains unclear the extent to which these factors contribute to program design and, in turn, students’ knowledge of MH nursing. Further research in this area is required.


title: An examination of laptop-based off-task behaviours in secondary school classrooms

subject:
Laptop
Off-task behaviours
Secondary school
Distraction
Gender differences

abstract: The purpose of this study was to examine factors that affect secondary school students’ off-task behaviours in laptop-based classrooms. Quantitative and qualitative data were collected from 224 secondary school students from four private schools in Canada (156 males, 65 females, 3 no response). The perceived advantages of laptop use in the classroom were access to information online, the use of technology during class, and the use of specific programs and applications during course work. The perceived disadvantages of laptop use in the classroom by students were being distracted by peers and engaged in off-task behaviours. The factors that appeared to influence off-task laptop-based activities were subject area, instructional method, and gender. Gender differences were found in students’ on-task activities and off-task activities. Females reported engaging in on-task activities significantly more than males. Females also engaged significantly more frequently in social media compared to males, whereas males played games significantly more often than females. More in-depth research, perhaps in the form of interviews and discussion groups, needs to be conducted on how subject area and instructional method might influence secondary school students’ off-task behaviours.


title: Milking anomie: experiencing food safety on Canadian dairy farms

contributor:
Hinch, Ron
Downing, Steven

subject:
Food safety
Farmers
Institutional anomie
Alienation
Canadian dairy industry

abstract: The developing discipline of Food Crime requires the analysis of food safety responsibility from a critical structural perspective. Analyzing the Canadian dairy industry, this project seeks to answer how the legal definition of food safety impacts the production practices of farmers, and where farmers place the burden of food safety responsibility, while partially testing institutional anomie theory. A legal discourse analysis of food safety law in Canada is performed to contextualize individual interviews with six active family-farmers in rural southern Ontario in order to determine how dairy farmers experience food safety legislation. As hypothesized, farmers experience food safety law through forms of disempowerment and alienation involving dairy production products, leading to a partial displacement of responsibility for safe food. The ideas of institutional anomie theory were insignificant or inconclusive for these case studies. More research is required to determine potential policy implications concerning the safety of Canadian food.


title: Analysis of hydrodynamic phenomena in a fluidized bed for thermochemical hydrogen production

contributor:
Dincer, Ibrahim
Naterer, Greg F.

subject:
Cupric Chloride
Fluidized bed
Transport phenomena
Hydrodynamics

abstract: This thesis examines transport phenomena of cupric chloride (CuCI2) hydrolysis within a fluidized bed.  Conversions of CuCi2 and steam as a fluidizing gas are numerically investigated using a new non-catalytic gas-solid reaction model, proposed in the literature but here updated for the purposes of the present study.  The results are illustrated considering two cases of kinetics for the consumption of particles: Volumetric Model and Shrinking Core Model.  Consistent results in terms of the conversion of reactants versus superficial velocity, bed inventory and bed temperature are obtained by developing new solution algorithms abased on each of the above kinetic models.


title: Exploring lateralized sensorimotor processing using somatosensory evoked potentials

contributor:
Yielder, Paul
Murphy, Bernadette

subject:
Somatosensory evoked potentials
Laterality
Sensorimotor integrations
Motor learning
Motor control

abstract:
Differences exist between the two upper limbs in the chosen motor control strategy when moving in dynamic environments. To date, a large body of literature has explored these differences but few studies have incorporated neurophysiological data to support their findings. By utilizing somatosensory evoked potentials (SEPs) we can gain insight into the underlying neurological processes at the levels of the spinal cord and the cortex in response to movement and motor learning. The
research conducted showed greater accuracy in the non-dominant limb following a novel tracing task. This was complimented by differential SEP peak amplitudes in the pathways that reflect cerebellar activation and sensorimotor integration. Additionally, the research also showed that when motor task acquisition occurs in the presence of sensory perturbations, the non-dominant limb is more accurate than a control group and there are differential changes in peaks reflecting the primary somatosensory cortex and the cerebellum


title: Youth homelessness: an exploration into the desire for family reunification

subject:
Youth homelessness
Family
Reunification
Reconnection
Trajectory

abstract: With family conflict serving as the predominant underlying factor that leads to youth homelessness, family has often been framed as “the problem.” As such, many youth services have ignored the role of family as potential solutions to youth homelessness, despite a growing body of literature suggesting family connectedness holds strong currency for youth. In a sample of 34 youth experiencing homelessness, interviews were conducted to explore the extent to which youth have desire for family reunification, and to examine how differences in length of homelessness impact youth’s family-life trajectories. The results indicate that most youth desire to reconnect with their families, and that youth who have experienced homelessness for a comparatively short time (under 1 year) have more supportive familial relations than do youth who have experienced a moderate (1-2 years) or long (over 2 years) time homeless. Optimism for family reunification tends to wane the longer one experiences homelessness.


title: Sex and seasonal variation in hippocampal volume and neurogenesis in the eastern chipmunk, Tamias striatus

contributor:
Saucier, Deborah
Lehmann, Hugo

subject: Hippocampus Neurogenesis Doublecortin Neuroecology Chipmunk

abstract: The hippocampus (HPC) is important in spatial memory and navigation and also exhibits adult neurogenesis. In wild-living species, HPC volume and neurogenesis have been found to differ between the sexes and vary seasonally in tandem with spatial behaviours such as food-caching and mating. However, few studies have simultaneously compared across sex and season, and the literature contains inconsistencies. The present study examined sex and seasonal differences in HPC volume and neurogenesis in the eastern chipmunk, Tamias Striatus. HPC volume was greatest in males after controlling for age, consistent with males' greater spatial behaviour, but was seasonally stable. Neurogenesis exhibited a curvilinear pattern across the active season after controlling for age, with no sex or seasonal differences corresponding to the timing of spatial behaviours. The pattern of results was partially consistent with predictions based on chipmunk behavioural ecology, with some unexpected results, highlighting the importance of studies involving naturally variant populations.

abstract: University of Ontario Institute of Technology


title: The Pharmacological Characterization of Hco-UNC-49, a GABA-gated Chloride Channel from the Parasitic Nematode Haemonchus contortus

subject:
H. contortus
GABA-A pharmacology,
UNC-49
Anthelmintics
Insecticides
Channel modulation

abstract: Compared to mammals, nematodes appear to exhibit a unique GABAergic nervous system. Haemonchus controtus is a parasitic nematode that infects ruminants worldwide. Hco-UNC-49 is a H. contortus GABA-gated chloride channel and is an orthologue to the UNC-49 channel from the free-living nematode Caenorhabditis elegans. Previous research by our group has shown that while the UNC-49 channels from the two nematodes share similar sequence homology they do not share identical sensitivity to GABA. To further investigate the characteristics of the Hco-UNC-49 channel, this study tested the effects of various modulators, insecticides and anti-parasitic drugs on channel function. Most notably, the molecules penicillin G, propofol and pregnenolone sulfate all had similar effects on Hco-UNC-49 as reported previously for Cel-UNC-49. On the other hand, Hco-UNC-49 appears to be less sensitive to picrotoxin inhibition compared to what has been reported for Cel-UNC-49. Novel effects of a number of anthelmintics were also observed. For example, the anthelmintics ivermectin and moxidectin both enhanced Hco-UNC-49 GABA responses, while piperazine was able to directly activate Hco-UNC-49 at high concentrations. These results suggest that Hco-UNC-49 is likely an in vivo target for these anthelmintics.


title: Experimental investigation of photocatalytic hydrogen production with boron-doped TiO2 and multi-walled carbon nanotubes-TiO2

subject:
Solar energy
Photocatalytic hydrogen production
Photoactive materials
Boron doped TiO2
Carbon nanotube-TiO2

abstract:
This thesis investigates photocatalytic hydrogen production by performing an experimental study using a small-scale photochemical cell which splits water to hydrogen and oxygen by UV light irradiated boron-doped TiO2 and carbon nanotube-TiO2 semiconductor
photoelectrodes. The average current densities generated under potentiostatic scan for uncoated stainless steel, boron-doped TiO2 and carbon nanotube-TiO2 working electrodes are observed to be 112.51 mA /cm2, 128.43 mA /cm2, and 164.73 mA /cm2 under UV light
respectively. Although amount of hydrogen produced by carbon nanotube-TiO2 is higher than boron-doped TiO2, boron-doped TiO2 has the maximum energy and exergy efficiencies. Moreover, in this study, alternative reactor designs are proposed and simulated on COMSOL Multiphysics software in order to improve the flow of the
hydrogen bubbles inside of the reactor. The simulation results showed that the amount of hydrogen at the beginning for the three designs 1.19 𝑐𝑚2 drops to 0.078 𝑐𝑚2 which shows 32.5% improvement and 0.0581 𝑐𝑚2 which represents 34.9% improvement in hydrogen released compared to the base design for first and second proposed designs respectively.


title: Understanding personal support workers and their role in Ontario.

subject:
Personal support workers
PSW
Long-term care
Homecare

abstract:
There are an estimated 90,000 personal support workers (PSWs) in Ontario providing assistance with daily activities for individuals in hospitals, long-term care
facilities, adult day programs and home care yet little is known about them. (Ontario Ministry of Health and Long-Term Care [MOHLTC], 2011b). The goals of this thesis
are to better understand where the occupation of PSWs is in its development towards
becoming a profession; and what the challenges, opportunities, and prospects are towards
this realization.
The data collection for this case study is based a scoping review of peer review articles and grey literature to describe who these workers are, their education, where they
work and regulatory structures that govern their practice. The analytical framework used
to examine the professional progression of PSWs is based on the neo-Weberian theory of
professions. PSWs are unregulated frontline providers. Many PSWs are immigrants and
visible minority females older than 45 years whose first language is not English
(Aronson, Denton, & Zeytinoglu, 2004; Neysmith, Reitsma-Street, Collins, & Porter,
2004; Canadian Research Network for Care in the Community [CRNCC], 2009a).
Employment status varies with the majority working in long-term care institutions.
However a considerable number of PSWs work in home care. Education for PSWs is not
standardized and educational requirements vary by work setting as does wage levels.
Turnover is high in this occupation and there is no unifying organization representing
PSWs.
This study has brought to the foreground several challenges. PSWs do not meet
the neo-Weberian criteria of a profession due to lack of strong leadership, adequate education, autonomy and resources that can support the complexity of a professional body. PSWs who work in the community setting have little or no support from other providers responsible for delegating and directing their work, suffer increased job
insecurity and decreased pay and/or benefits.


title: Robotic radiation mapping using modelling and probabilistic analysis of sparse data

contributor:
Nokleby, Scott
Waller, Ed

subject:
Radiation mapping
Robotics
Markov Chain Monte Carlo

abstract:
An approach for generating radiation intensity maps, comprised of a mobile robotic platform and an integrated radiation model, is presented, and its ability to generate accurate radiation maps in simulation studies as well as real-life exposure scenarios are investigated.
The radiation intensity mapping approach described here consists of two stages. First, radiation intensity samples are collected using a radiation sensor mounted on a mobile robotic platform, reducing the risk of exposure to humans from an unknown radiation field. Next, these samples, which need only to be taken from a subsection of the entire area being mapped, are then used to calibrate a radiation model. This model is then used to predict the radiation intensity field throughout the rest of the area.
In this thesis, the technical details of both the prototype mobile robotic platform and the mathematical models for the radiation and map generation algorithms are presented in depth. The performance of the approach is evaluated in simulation studies and experiments in the lab. The sensitivity of the performance of the platform to changes in the number and orientation of the locations where the robot gathers samples from to calibrate the model for the given exposure scenario is analyzed quantitatively.
The results show that the developed system is effective at achieving the goal of generating radiation maps using sparse data.


title: Transient heat transfer analysis of heat exchangers in a Marnoch Heat Engine

contributor:
Naterer, Greg
Dincer, Ibrahim

subject:
Waste
Heat recovery
Power generation
Heat exchanger
Heat transfer
Marnoch Heat Engine

abstract: The Marnoch heat engine (MHE) is a new type of power generation device that is under research and development at the University of Ontario Institute of Technology. In this thesis, the transient heat transfer behaviour of the source heat exchanger of the Marnoch heat engine is studied, and its operation for laminar and turbulent flows is modelled. The temperature variations of the working fluid, the heating fluid and the wall, are calculated. The temperature distribution of the fluids and the wall over the length of the heat exchanger is also calculated. It is found that the temperature of the working fluid rises sharply to a peak and then gradually decreases. The wall temperature decreases exponentially, and the temperature of the heating fluid falls sharply, and then gradually decreases. A base model for the step change in the mass flow of the working fluid is developed and compared against past works for the purpose of validation.


title: Automated partial premature infant pain profile scoring using big data analytics

subject:
Neonate
Neonatal pain management
Clinical decision support system
Pain scale
Physiological data streams

abstract:
Lack of valid and reliable pain assessment in the neonatal population has become a significant challenge in the Neonatal Intensive Care Unit (NICU). Current practice in the NICU involves the meticulous, time-consuming and potentially bias process of manual interpretation of pain scores.
In an attempt to forego the manual scoring system, this thesis presents an initial framework to automate a partial pain score for newborn infants using big data analytics that automates the analysis of high speed physiological data. The design of the novel Artemis Premature Infant Pain
Profile (APIPP) is proposed in this thesis. An ethically approved retrospective clinical research study was performed to calculate APIPP scores from premature infant data collected from the
Artemis platform. Using the Premature Infant Pain Profile (PIPP) as the base gold standard scale, scoring techniques were automated to create data abstractions from the physiological streams of Heart Rate (HR) and Oxygen Saturation (SpO2). These were then brought together to compute an automated partial pain score (APIPP) that was based on gestational age, HR and SpO2. Through the retrospective clinical research study, and to evaluate the effectiveness and feasibility of automating the scale in the future, APIPP was retrospectively compared with the PIPP which was manually scored by nursing staff at The Hospital for Sick Children, Toronto. Furthermore, the characteristics in HR were also assessed in a thorough manner by preforming statistical tests to assess the resourcefulness of HR as a measure to identify a pain response. Future research will focus on the clinical validation of this work by carrying out prospective research to implement an algorithm based on the design proposed in this thesis that can be integrated into a clinical decision support system named Artemis.


title: A contextual authentication framework for smart home environments

subject:
Smart home security
Context-based user authentication
App-based user authentication
Device-to-device message authentication
Identity-based signcryption

abstract: A smart home is one equipped with connected Internet-of-Things (IoT) devices that can be remotely accessed and controlled. Access to smart home devices is mostly achieved through smartphones and tablet computers, but this comes with security challenges such as unauthorized access and interception of data transmission. Although smart home devices are critical, many examples of security challenges, such as unauthorized access to home devices and interception of data transmission, are reported. Furthermore, many home IoT devices are still shipped with default credentials even though it is widely known that these settings are used in attacks. A number of cryptographic schemes have been proposed for securing communication among home IoT devices. However, the ability to handle such schemes, especially by devices with constrained computing resources, can be challenging. To address the above issues, this thesis introduces a contextual authentication framework for smart home environments that integrates a context-based user authentication method, a device-to-device message authentication scheme, and an app-based user authentication model. A proof of concept prototype of context-based authentication has been constructed. An identity-based signcryption scheme for securing data transmission between home IoT devices has been designed, and an app-based user authentication model has been developed. The results demonstrate that considerable contextual information can be retrieved and such information can be used in providing seamless, usable, and secure authentication. Furthermore, analysis and evaluation of the proposed signcryption scheme demonstrate that, in addition to providing authentication, it provides integrity and confidentiality as well as the ability to protect communication against possible attacks. The evaluation of the app-based user authentication model is performed on three datasets, and the results show that the model has the ability to authenticate users with high accuracy in terms of low false positive, false negative and equal error rates.


title: Analysis and processing issues of plastic color mismatch

subject: Colorants Pigments Resins Temperature RPM

abstract:
Color is a visual characteristic which imparts the ability to categorize different
objects. When light strikes an object, there are three possibilities as to what can happen.
The light may be reflected, refracted or scattered. Human perception of color is due to a
combination of these. Plastics are polymeric materials. Polymers are generally colorless
and need colorants in order to have some color. One or more pigments in certain ratios
can be used to give a specific color to plastics. Slight variations in the proportions of
either of the used pigments, or their dispersion, may result in a color that is different from
the desired one. There can also be many other reasons for color mismatch such as
processing or degradation effects.
This study utilized the historical data records of SABIC IP to look at effects of
changing Grade on color (i.e. when the same color is produced from resin blends which
may have different amounts of resins, pigments or additives). These records were also
used to study effects of change in screw diameter and configuration on color (i.e. when
the same grade of a color is produced on two different production lines, different screw
diameters and configurations).
The effects of the processing parameters on the colors were also investigated by
carrying out experiments using a twin screw extruder at SABIC IP’s plant in Cobourg.
Resins, pigments and additives were dry blended and extruded while being subjected to
different processing conditions. Three processing parameters, namely temperature, rpm
and feed-rate, were chosen for the study. A three level factorial design of experiments
was used. An analysis of variance (ANOVA) has been utilized to find the effects of
individual parameters on color and the interaction between two parameters and their
cumulative effect on color.


title: The transcription factor, fixK, plays a central role in carbon source metabolism and cellulose synthesis in Komagataeibacter species

subject:
Komagataeibacter xylinus
Komagataeibacter hansenii
fixK
Bacterial cellulose
Carbon source

abstract: Komagataeibacter xylinus ATCC 53582 and K. hansenii ATCC 23769 are model bacterial cellulose producers. This thesis investigated both carbon source utilization and the role that a Crp/Fnr transcription factor, FixK, plays in bacterial cellulose biosynthesis. Extracellular proteins secreted by Komagataeibacter were assayed for degradative activity against plant cell wall compounds. Mutagenesis of fixK, previously associated with cellulose regulation, revealed its role in cellular metabolism. Growth, pH, gluconic acid, and cellulose yield were measured in static and agitated cultures grown in the presence of glucose, fructose or sucrose. BcsZ (formerly CmcAx) was found to be carbon-source regulated. K. hansenii was dependent on fixK for growth in fructose and sucrose, but not in glucose. Mutation of fixK abolished cellulose production in K. hansenii, but limited production in K. xylinus. Altogether, this study improves our understanding of carbon source utilization and bacterial cellulose synthesis in Komagataeibacter species.


title: Towards trusted and efficient temporal relational databases

contributor:
Pu, Ken
Zhu, Ying

subject:
Temporal database
Blockchain
Trustworthy data
Query optimization

abstract: This research is to develop a blockchain based database based on a relational database management system (RDBMS). The database guarantees authenticity of the stored records using immutable and verifiable signatures. The database supports query evaluation over the entire timeline of the transaction log. To support efficient query evaluation, we utilize materialized snapshots at selected timestamps. We propose an optimal snapshot algorithm to compute the best timestamps so that the overall query load can be evaluated with minimal computation.


title: Exploring entities in text with descriptive non-photorealistic rendering

subject: IIlustrative visualization

subject: Integrating spatial and non-spatial data

subject: Text visualization

subject: User interfaces

abstract:
We present a novel approach to text visualization called descriptive non-photorealistic
rendering which exploits the inherent spatial and abstract dimensions in text documents
to integrate 3D non-photorealistic rendering with information visualization. The visualization
encodes text data onto 3D models, emphasizing the relative signi ficance of words
in the text and the physical, real-world relationships between those words. Analytic exploration
is supported through a collection of interactive widgets and direct multitouch
interaction with the 3D models. We applied our method to analyze a collection of vehicle
complaint reports from National Highway Traffic Safety Administration (NHTSA),
and through a qualitative evaluation study, we demonstrate how our system can support
tasks such as comparing the reliability of di fferent makes and models, finding interesting
facts, and revealing possible causal relations between car parts.


title: Hybrid inductive and capacitive wireless power transfer system for future transportation electrification

subject:
Coupling
Electric vehicles
Inductive
Capacitive
Wireless power

abstract:
The inductive link in wireless power transfer (WPT) fed by various high–frequency power converters is widely accepted for medium power (<50 kW) and medium power transfer distance (100 mm-200 mm) applications due to remarkable efficiencies (>90%) in stationary wireless charging scenarios. However, considering the dynamic or the on the move wireless charging, the inductive link implementation for millions of kilometers is quite expensive due to the need for sophisticated resources. Therefore, relatively inexpensive capacitive link, which initially focused on low power (<100 watts) and small distance (<10 mm) applications, has gained momentum and is explored for medium power (~3 kW) and medium distance (~100 mm) applications. It has achieved considerable DC-DC efficiencies (70%-90%), no induced eddy current loss in the nearby metal objects and low cost and weight implementation.
First, the thesis identifies the significant roles played by inductive and capacitive AC link designs in static and dynamic expansion of wireless electric vehicle charging. Through a relative analysis, the thesis emphasizes the need for mutual promotion of these AC links as a hybrid system in order to boost wireless EV charging technology. Second, capacitive wireless power transfer system is analyzed under different link configurations and dielectric influences aiming to improve their performances. Third, a reduced capacitance model is derived from the existing six capacitance model of bipolar 2x2 matrix configuration which is suitable for large charging area applications like electric vehicle charging. Here, when the separation distance between the same side plate pair is large enough, the effect of cross-coupling capacitances diminishes and the analysis based on a reduced capacitance model can be carried out. The advantage of using this model is that it attains the unity gain and load-independent operation at designed resonant frequency instead of at dual resonant frequencies in the conventional model. Fourth, a novel hybrid inductive and capacitive wireless power transfer system is realized by combining both systems using a three-leg, mixed switching frequency inverter. The combination offered a choice of power management between two systems. The modular structure makes both systems independent and helps to achieve individual or combined wireless power transfer.


title: Characterization of the ACC-1 Family of cys-loop ligand gated ion  channels from the parasitic nematode Haemonchus contortus.

subject:
Acetylcholine
ACC
Haemonchus contortus
Cys-loop receptors
Anthelmintic resistance

abstract: Nematode cys-loop ligand-gated ion channels (LGICs) have been extensively studied for decades because of their role in current anthelmintic action and potential as targets for future drugs. Many families of cys loop receptors have not yet been pharmacologically characterized in parasitic nematodes, and thus provides an opportunity for further exploration into their role in the nervous system of these pathogens, and relevance for anthelmintic action. The ACC-1 family of receptors is a group of inhibitory acetylcholinegated chloride channels that are unique to invertebrate species. Specifically, the ACCs have been identified in both free-living (Caenorhabditis elegans) and parasitic (Haemonchus contortus) nematodes. However, their pharmacological properties in H. contortus have yet to be explored. My PhD thesis focused on identifying and characterizing the role of the ACC-1 family of receptors in H. contortus, using molecular cloning, pharmacological characterization and an investigation of the ligand-binding pockets using site directed mutagenesis and computational protein modelling. I conducted an extensive pharmacological characterization of the following receptors, ACC-2, ACC-1/ACC-2, ACC-1/LGC-46, LGC-46, LGC-39/ACC-1, and LGC-40/ACC-1, and generated homology models for each with various ligands bound. The ACC receptors from H. contortus are sensitive to various cholinergic ligands, nicotinic acetylcholine receptor anthelmintics, classical antagonists, and minimally sensitive to nicotine. Although one particular subunit, ACC-1, does not form a functional channel alone, it does associate with other members of the ACC family, ACC-2 and LGC-46, as well the previously uncharacterized cholinergic receptors, LGC-39 and 40, to form unique heteromeric channels. In addition, it was found that a single point mutation of a phenylalanine residue to a tyrosine in Loop C of the ACC binding pocket results in a hypersensitive receptor. Finally, sequence analysis of the ACCs revealed that the characteristic tryptophan residue, which contributes to π-cationic stabilizing interactions with ligands in the binding pocket, is located in Loop C of these receptors, whereas this residue is commonly found in Loop B of mammalian nAChRs. Together, this dissertation provides the first characterization of these inhibitory ACh receptors in parasitic nematodes and further sheds light into cholinergic neurotransmission in H. contortus.


title: An exploration of palliative care providers’ lived experiences of implementing the gold standards framework in oncology care from a hospital-based, outpatient palliative care setting

subject:
Cancer
Palliative care
Gold standards framework
Healthcare providers
Palliative

abstract: Palliative care aims to address the needs of patients and family members who are dealing with a life-altering illness. The Gold Standards Framework (GSF), consisting of 7 key components (Communication, Coordination, Control of Symptoms, Continuity of Care, Continued Learning, Carer Support and Care in the Dying Phase), is a tool implemented in palliative care to ensure such objectives are met. Therefore, through an in-depth qualitative analysis, this thesis examined the lived experiences of 6 palliative care providers on implementing the GSF in oncology care from a hospital-based, outpatient palliative care setting. The GSF facilitated the interpretation of the results according to each component of the framework and 11 subthemes emerged. This study highlights the facilitators and barriers that impact the implementation of the GSF in a hospital-based, outpatient setting. This study has implications for palliative care practice, policy, education and research to help strengthen the development of sustainable palliative care.


title: Climbing the corporate ladder: desired skills and successful psychopaths

subject:
Psychopathy
Corporations
CEO
Personality traits
Systemic psychopathy

abstract: Many of the characteristics embodied by successful psychopaths, such as superficial charm, cool decisiveness, and a grandiose self-worth, are often treated synonymously with corporate leadership qualities. Consequently, successful psychopaths are actively being selected for corporate positions as they exemplify the perfect candidate. These successful psychopaths, as corporate leaders and recruiters, increase the probability of systemic psychopathy and white-collar crime. The current study will provide a deeper understanding of successful psychopaths while exploring the role of the “Westernized” corporation in recruiting successful psychopaths into their businesses through character descriptions in 25 executive career advertisements using Wexler’s (2008) Psychopathic Personality Dimensions and Positively Reinforced Corporate Labels. Results demonstrated that corporations are seeking out characteristics that are synonymous to Factor 1 psychopathic personality traits, which could increase the propensity of successful psychopaths in the workplace. This paper discusses the implications of these findings and identifies some potentially useful approaches for excluding corporate psychopaths from organizations.


title: A CFD analysis of the pressure drop through misaligned Stirling engine regenerators

subject:
Stirling engine
Regenerator
Misalignment
Pressure drop
CFD

abstract: Experiments were conducted to discover the average misalignment in wire mesh regenerators, and it was found that regardless of the intended stacking arrangement, the average misalignment was 44% to 49%. A 3-dimensional CFD model was validated against previous empirical results, and used to determine the effect of wire mesh misalignment on the pressure drop for ow through a regenerator. A friction factor correlation equation was developed and it was found that a perfectly aligned regenerator could result in a 38% to 45% decrease in pressure losses. The model was also used to determine the influence of axial spacing on the pressure drop, and it was found to be dependent on the misalignment, with pressure loss reductions only being realized in highly misaligned cases. As a result of this thesis, Stirling designers can confidently disregard alignment and spacing when assembling wire mesh regenerators, and can more accurately calculate the pressure losses.


title: Prevalence and patterns of alcohol consumption among persons with dementia in Canada

subject:
Alcohol consumption
Alzheimer’s disease
Dementia

abstract:
Aim: To identify the prevalence of alcohol consumption and its impact on chronic disease, injury and hospital stays in persons with dementia (PWD).
Methods: Multivariate analysis was conducted using data collected from a nationwide population-based survey, Canadian Community Health Survey (CCHS).
Results: PWD consume alcohol at comparable rates to persons without dementia. A reported 60% of PWD consume alcohol. Males more often reported alcohol consumption than females. Multivariate analysis showed PWD who consumed alcohol were less likely to report chronic conditions such as heart disease (22% vs 30%) and diabetes (13% vs 24%) than their counterparts who abstained from consumption.
Conclusions: Lower rates of injury, hospital stays, and various chronic diseases demonstrates the importance of assessing alcohol consumption in PWD. A better understanding of drinking habits in PWD would allow for the development of recommendations and guidelines to alcohol consumption.

abstract: University of Ontario Institute of Technology


title: Developing a framework for thermodynamic measurements of fluoride salt nuclear fuel

subject:
Thermodynamics
Molten salt reactor
Nuclear

abstract: With a single liquid acting simultaneously as a primary coolant and a nuclear fuel, molten salt reactor development has been challenged with understanding the behavior of its complex fluoride solution under various conditions. Experimental thermodynamics can address part of this challenge by providing insights into the system’s behaviour, such as melting points, heat capacities, and solubilities. The current work develops an experimental framework for studying the experimental thermodynamics of fluoride nuclear salt materials. By establishing experimental capabilities and practises, experimental routines are qualified with the goal of providing background on the environment of error of future thermodynamic measurements using differential scanning calorimetry. Infrastructure, standard procedures, a custom crucible, and qualification of a routine for thermodynamic measurements have been developed. Study on particle size reduction, material interactions, and techniques for purification demonstrated a promising environment for thermodynamic measurements.


title: Situation tables as the new crime prevention: theoretical underpinnings, strengths, weaknesses, and best practices

subject:
Community safety and wellbeing
Policing
Risk
Collaboration
Harm reduction

abstract: Change in police calls-for-service has resulted in a shift in the role of police through the years. Specifically, the increase in mental health calls for police services has created the Community Safety and Well-Being (CSWB) model. The CSWB model seeks to prevent social disorganization through proactive community efforts. Situation Tables are a risk-driven, collaborative model in Ontario that falls under the CSWB model. Drawing on in-depth interviews from Situation Table coordinators and other participants, this thesis found that risk, collaboration, and harm reduction are the theoretical underpinnings of the Situation Table. Interestingly, participants identified Situation Tables as an alternative to incarceration in that they proactively address criminal risk factors and offer social services rather than engaging in law enforcement action. In addition, this thesis offers recommendations and best practices for the participation and implementation of Situation Tables as a learning tool for current and future Situation Table participants.


title: Modeling and simulation of The CERTS Microgrid: a comparative study using PSCAD and MATLAB SIMSCAPE

contributor:
Ibrahim, Walid Morsi
Sidhu, Tarlochan

subject:
Micro modelling
Microgrid simulations
PSCAD
Simulink
Renewable energy

abstract:
The legacy electric power system has grown in magnitude and complexity since its conception. This was a result of various advancements, such as the need to match the increase in power demand, and to address the shortage of conventional sources (e.g. oil and gas). This led to the integration of Distributed Generators (DGs) into the legacy grid, thereby facilitating the incorporation of microgrids. An adverse effect can be seen with the large-scale penetration of various distributed generation (DGs) caused by the utilization of switching devices and inconsistent performance of the DGs. The effects of incorporating switching devices has led to issues such as an increase in harmonics, voltage, frequency regulation, power quality degradation, and reverse power flow.
A cost-effective approach to study the abovementioned impacts is via modelling and simulating the system in well-known simulating platforms such as Power System Computer Aided Design (PSCAD) and MATLAB Matlab-Simscape. To that note, the fundamental difference between the two simulation environments is that Matlab-Simscape is based on solving a system of ordinary differential equations (ODEs) represented in the form of matrices using ODE45 and its variations, while PSCAD utilizes electromagnetic transient including DC (EMTDC). EMTDC represents the system as differential equations for both electromagnetic and electromechanical systems in the time domain. Solutions are based on a fixed time step and the results are solved as instantaneous values in time. Therefore, modelling the same component in either of them can result in some inconsistencies in the output quantities.
In this work, the modeling of the microgrid in both simulation platforms is studied and the model transformation approach is introduced, which highlights the procedure to model any component in the two simulation environments to generate consistent results. Additionally, both simulation platforms are studied in detail utilizing a standardized microgrid benchmark system, known as the Consortium for Electric Reliability Technology Solution (CERTS) microgrid. This CERTS configuration defines the framework necessary to measure and adjust the performance of both simulation platforms in a quantitative and qualitative manner. Furthermore, a methodology is proposed to model the various components of the microgrid in a uniform and interchangeable manner. Ultimately, the proposed methodology overcomes the differences in modelling some electrical components in each platform. In addition, the properties of each component in both software have been highlighted in detail to facilitate the transition between each platform.
Finally, this work introduces a comparative study between PSCAD and Matlab-Simscape based on the CERTS microgrid. The performance of both simulating platforms is studied in both the grid connected mode of operation and in the island mode of operation. The performance of both simulating platforms is evaluated, and the results are presented to demonstrate the validity of the modeling techniques. The results have shown that the difference between the quantities measured at the same point of measurement in both simulation platforms are less than 1%, which verifies that the modeling technique results in uniform outcomes in both PSCAD and Matlab-Simscape.


title: Development of FEA wide-base truck tire and soil interaction models

subject:
FEA wide-base tire modeling
SPH soil model
Hybrid SPH/FEA soil model
Tire/terrain interaction

abstract: Tires are considered one of the most important components of ground vehicles as they are the only link between the chassis and ground. They support the vehicle weight and cushion road surface irregularities to provide a comfortable ride. Tires are designed in a way that provide necessary tractive, braking, and cornering forces to form a safe and stable ride for ground vehicles. Recent advancements in computerized and virtual modeling provided an efficient methodology for accurate prediction of tire characteristics. In this thesis Finite Element Analysis (FEA) is employed as a method to accurately construct a new virtual wide-base tire model, validate it, and then study rolling resistance of the tire on a hard surface. This thesis includes tire-soil interaction and effects of soil on tires rolling resistance. To accurately study rolling resistance on soft soil, various soil models are created by using FEA and Smoothed Particle Hydrodynamics (SPH), as a representative of dry sand soil. Soil models are calibrated by using shear-displacement and pressure-sinkage simulation tests. The simulation results are then compared to published data. Also, the created soil models are compared to each other to determine the optimum one based on computational time efficiency and accuracy. SPH, as the accurate current method for soil modeling, has long computational solving time. In this thesis FEA/SPH hybrid soil models are studied and modified to achieve lower computational solving time while having the desirable accuracy. Rolling resistance of tire on each soil model is carried out through various loads and inflation pressures and the simulation results are compared to physical test results to examine the accuracy of each soil model. The new hybrid soil model created in this thesis reduces the computational CPU time almost by half and slightly increases accuracy compared to full SPH soil model.


title: Effect of diameter ratios on the flow-sound interaction of the straight circular finned cylinders

subject:
Vortex shedding
Finned cylinders
Phase-locked PIV
Acoustic resonance
LES

abstract:
Finned tubes that are widely used in heat exchangers could be susceptible to the flow-excited acoustic resonance that generates intense pressure fluctuations, which may lead to premature fatigue failure of the tubes. This thesis explores the unsteady flow development around circular finned tubes and its role in the excitation of acoustic resonance. Finned cylinders with same effective diameter (De f f ), fin pitch (p), fin thickness (t) and a range of diameter ratios between 1.25 _ Df =Dr _ 2.5 are considered. Results from the PIV measurements at Re = 20000 demonstrated that the extent of the recirculation region decreases downstream of the finned cylinders when the diameter ratio increases due to higher flow entrainment between the fins. The frequency spectra of the streamwise velocity fluctuations showed that the temporal evolution of the vortex shedding in the wake becomes more periodic when the diameter ratio of the finned cylinders (Df =Dr) increases. Moreover, the strength of the vortices increases significantly in the wake. The increase in the flow entrainment in between the fins leads to a pronounced reduction in the random velocity fluctuations in the near wake of the cylinders.
The three-dimensional flow development and structural loading on the finned cylinders are studied using Large Eddy Simulation. In addition to the flow entrainment mechanism in between the fins, another entrainment mechanism in the near wake is found to be caused by the downwash flow induced by an array of edge vortices that generate at the tip of the fins. The RMS of the fluctuating lift coefficient increases significantly on the surface of the finned cylinders due to a reduction in the vortex formation length and enhanced vortex strength. Moreover, the increase in skin friction on the surface of the cylinders, as a result of the higher flow entrainment, causes a significant increase in the drag coefficient for finned cylinders with larger diameter ratios (Df =Dr ).
The results from the aeroacoustic response show that the excitation of acoustic resonance in the case of finned cylinders occurs at lower flow velocities compared to that of bare cylinders. This is mainly due to the existence of more energetic vortex shedding in the wake of the finned cylinders. Moreover, the normalized acoustic pressure generated during resonance excitation increases significantly as a result of an enhanced vortex strength and a reduced vortex formation length. Phase-locked particle image velocimetry (PIV) measurements during resonance excitation reveal that the global effect of the fins on the vortex shedding affects the location of the acoustic sources and sinks in the flow field as well as the energy transfer mechanism between the flow and the sound fields.


title: Structure guided image restoration : a deep learning approach

subject: Deep-learning Image-restoration Image-Inpainting Super-resolution

abstract:
Image restoration aims at recovery of degraded images and estimating the original. Over the past few years, computer vision research has been dominated by deep learning techniques in part due to advances in computing infrastructure, algorithms and image capturing devices. As a result, deep neural networks currently set the state-of-the-art in image restoration problems. However, many of these techniques fail to reconstruct reasonable structures as they are commonly over-smoothed and/or blurry.
In this dissertation, we develop models based on deep convolutional neural networks to address two image restoration problems: image inpainting and image super-resolution. We develop a new approach for image inpainting that does a better job of reproducing missing regions exhibiting fine details. Furthermore, we extend this method to image superresolution by reformulating the problem as an in-between pixels inpainting task. We propose a two-stage adversarial model that comprises of an edge generator followed by an image completion network. The edge generator hallucinates edges of the missing region of the image, and the image completion network fills in the missing regions using hallucinated edges as a priori. We evaluate our model over the publicly available datasets and show that it outperforms current state-of-the-art techniques quantitatively and qualitatively.


title: Integrated heat pump options for heat upgrading in Cu-Cl cycle for hydrogen production

contributor:
Dincer, Ibrahim
Rosen, Marc A.

subject:
Cascaded heat pump
Mercury
Biphenyl
CuCl
Coefficient of performance

abstract:
The Copper Chlorine (Cu-Cl) hydrogen production cycle is a promising green method to meet the future demand for hydrogen. The Cu-Cl cycle has a number of endothermic reactions that take place at high temperature level. One of the highest temperature demanding components in the Cu-Cl cycle is the copper oxychloride decomposition reactor. This thesis proposes two potential methods to address this demand by using a cuprous chloride (CuCl) vapor compression heat pump cascaded with a mercury heat pump as a first option, and cascaded with a biphenyl heat pump as a second option. These cascaded heat pumps are meant to upgrade heat from nuclear power plants with a heat input of approximately 300⁰C or industrial waste heat to meet the copper oxychloride decomposition reactor demand. A comprehensive energetic, exergetic, and exergoeconomic assessment is made to understand the heat pump performance and costs.
The CuCl-mercury heat pump had an overall energetic coefficient of performance of 1.93 and an exergetic performance of 1.25. Its total estimated cost is US$1,446,554 which is 62% higher than that estimated for its CuCl-biphenyl counterpart. Nevertheless, the CuCl-mercury heat pump has the lowest exergy destruction cost flow rate of 2,045 $/hour.
The CuCl-biphenyl heat pump, on the other hand, also shows high coefficient of performance for certain operating conditions of compressors isentropic efficiencies, and excess CuCl feed temperature. Its base energetic and exergetic coefficient of performances are 1.76 and 1.15, respectively. Its estimated cost of $892,440 is lower than its CuCl-mercury counterpart. However, its overall exergy destruction cost flow rate was two times higher, 4,903 $/hour.


title: Muscle fatigue and other factors influencing forearm muscle activity

contributor:
Holmes, Michael
Murphy, Bernadette

subject:
Forearm
Muscle activity
Performance
Fatigue
Neuromuscular physiology

abstract:
The wrist extensor muscles of the forearm exhibit relatively greater muscle activity than the wrist flexors during most hand/wrist tasks. Since the extensors operate at a greater percentage of maximum to balance wrist joint moments, this could contribute to their higher incidence of overuse injury. However, current knowledge of forearm muscle function comes primarily from isometric research or from studies examining isolated motor tasks. Conclusions derived from this work may not translate to tasks of daily living, which are typically dynamic and performed by multiple muscle actions simultaneously. Additionally, while fatigue develops more rapidly in the extensors than the flexors, the consequences of fatigue between these two muscle groups are presently unclear.
The objectives of this thesis were broken into two parts. Part 1: Quantify forearm muscle recruitment during the simultaneous execution of various handgrip and wrist forces (Chapter 3) and during dynamic wrist exertions (Chapter 4). Part 2: Characterize the effects of sustained isometric wrist flexion and wrist extension contractions on hand-tracking accuracy (Chapter 5) and investigate the underlying central mechanisms that may contribute to accuracy impairments (Chapter 6).
In Part 1, we identified that the muscle activity of the wrist flexors was highly sensitive to changes in dual-task parameters (grip and wrist exertions), while the activity of the extensors was consistently greater than the flexors during both dual-task and dynamic contractions. In some conditions, the wrist extensors exceeded flexor activity even during pure wrist flexion contractions. In Part 2, it was found that inducing fatigue separately through sustained wrist extension and wrist flexion contractions significantly impaired hand-tracking accuracy. However, there were no differences in hand-tracking accuracy between the two methods of inducing fatigue. This was surprising, given that follow-up work demonstrated both muscle activity and corticospinal differences between the muscle groups following sustained contractions.
This thesis provides a robust examination of the factors that can influence forearm muscle recruitment. It is also the first work to document the consequences of fatigue in opposing muscle groups of the forearm. The conclusions drawn from this research are essential in furthering our understanding of overuse injury development in the distal upper-limb.


title: Is Yang style Tai Chi a “one size fits all” fall prevention exercise program for older adults?

subject:
Older adults
Exercise
Physical function
Falls
Tai Chi

abstract: Falls among Canadian older adults is a growing problem, not only in terms of incident rates and its impacts, but most importantly, the vast scope of preventable morbidity and mortality. A decline in age-related physical function is acknowledged as a risk factor of falls. Community-based group exercise programs such as Yang style tai chi may help to reduce fall risk by improving components of physical function. To investigate, a pretest-posttest experimental design was conducted. Post-intervention assessments revealed Yang style tai chi practiced three times a week over eight weeks improved balance, muscle strength and muscle endurance. These findings suggest Yang style tai chi is moderately effective in reducing fall risk but further research is needed to determine the true effectiveness of tai chi as a fall prevention strategy. This study provides directions for future research guided by a proposed conceptual framework and offers some tentative recommendations for community health practice.


title: A framework for anomalous activity analysis for intrusion detection with applications to IoT networks

subject:
Internet of Things
Anomaly detection
Deep learning
Generative adversarial networks
Convolutional neural network

abstract:
Computer systems have become an integral part of our daily lives. The Internet of Things (IoT) has recently attracted considerable attention in the information technology industry due to its various benefits. IoT activities increase the quantity of information shared. It produces new services through the Internet due to advancements in information and communication technology. The growing development of IoT devices creates a large attack surface for cybercriminals to conduct potentially more destructive cyberattacks; as a result, the security industry has seen an exponential increase in cyber-attacks. These attacks have effectively accomplished malicious goals because intruders use novel and innovative techniques to conduct cyber-attacks. The security of IoT networks is becoming increasingly challenging, and anomaly detection for IoT networks is a critical technique for addressing this issue.
The security challenge is to develop techniques to identify malicious activity correctly, mitigate the impact of such activity, and utilize them to implement enhanced Intrusion Detection Systems (IDS) to detect novel trends of cyber-attacks. Anomaly-based IDSs that use machine learning methods can detect and classify anomalies in IoT networks. This thesis design a framework for anomalous activity analysis for intrusion detection with applications to IoT networks. Anomaly detection frameworks based on nonparametric machine learning methods, feed-forward neural networks, convolutional neural networks, recurrent neural networks, and generative adversarial networks have been designed. A technique for creating a new dataset from existing pcap files has been described. The proposed technique created five IoT network intrusion datasets from existing pcap files. A method for identifying IoT devices connected to a network using machine learning has been proposed. Two datasets were generated for IoT device identification utilizing preexisting pcap files. The generated datasets are publicly available.
The performance of anomalous activity analysis frameworks was evaluated and tested in binary and multiclass classification environments using four network intrusion datasets and five IoT network intrusion datasets. In each evaluative situation, the frameworks in this thesis improve the benchmark techniques in terms of accuracy, precision, recall, and F1 score.


title: Risk management at public events: a case study of a municipality within Southern Ontario

subject:
Risk
Public events
Risk management
Terrorism
Municipality

abstract: Current literature surrounding risk management at public events focuses on the efforts of municipal officials to reduce the risk of terrorist activity. The literature only focuses on large municipalities that host global sporting events like the FIFA World Cup and the Olympics. The focus tends to be on a broad global view of terrorism superseding other types of mundane criminal activities that are more likely to occur at smaller municipalities and venues. In this thesis, an analysis of potential risks at public events hosted by a medium-size municipality is examined. By analyzing the responses of in-depth interviews with municipal officials, performing a content analysis of their Standard Operating Procedures (SOPs), and participating in direct observation of municipal events, this study determines that differences exist between the risks outlined in existing literature and the perceptions of risk garnered from the experience of those that work in the field. Security officials of this medium-size municipality define risks as “emergencies” and consider the risk of stampedes and environmental disasters as a greater threat than terrorism within their events.


title: Scalable immersive audio for virtual environments

contributor:
Kapralos, Bill
Mirza-Babaei, Pejman

subject:
Virtual environments
Spatial sound
CPU/GPU

abstract: This thesis discusses the history of game sound and how it developed to become increasingly more immersive and realistic by accounting for the spatial aspects of sound. It then compares several 3D sound technologies before continuing on to present a custom spatial sound system that uses the highly parallel nature of modern graphics processing units (GPUs) to process large amounts of data for simulated sound propagation. In a real-time virtual reality game environment, the system is able to handle dynamic geometry and movable sound sources in full 3D at interactive rates. To test the implementation, I developed a VR-compatible video game for desktop and mobile platforms with an emphasis on play-by-sound gameplay mechanics. Results demonstrated low overhead on all devices tested when used with the appropriate pathfinding backend (CPU/GPU). Additional testing yielded that the GPU part of the system is capable of processing several thousand 3D paths at interactive rates.


title: Behavioural and neurophysiological measures of haptic feedback during a drilling simulation

subject:
Haptic feedback
Simulation
Motor performance
Electroencephalography
Event-related desynchronization

abstract: Virtual environments (VEs) and computer-generated simulations are becoming more prevalent as tools for education, rehabilitation, and training purposes. As technology enhances the quality and quantity of human-machine interfaces, it is essential that we expand our understanding of multimodal interactions, and how they influence our virtual experience and associated brain activity. Haptic sensation, or touch, is often neglected in VE research. In this thesis, Study 1 showed that haptic force-feedback in a drilling simulation improved motor performance and ratings of perceived reality, as compared to trials without haptic feedback. Study 2 used electroencephalography measures and demonstrated greater desynchronization in trials with haptic feedback, as compared to trials without haptic feedback. Large effect sizes were found between haptic and non-haptic trials in the alpha frequency band (8-13 Hz). This work provides evidence that task-relevant haptic feedback can enhance motor performance, and may facilitate motor learning processes.


title: Forward screening for herbicide resistance in Arabidopsis thaliana and the monocot species Triticum aestivum

subject: Cellulose Triticum Arabidopsis Indaziflam Genetics

abstract:
Cellulose is the primary structural component of plant cell walls and is composed of β-1,4-glucan chains. The cellulose synthesis complex is composed of multiple cellulose synthases (CESAs), which work together to extend the cellulose molecule. Although extensively studied, cellulose biosynthesis is not yet fully understood. One way to elucidate the role of CESAs is through their interactions with cellulose biosynthesis inhibitors (CBIs). CBI resistant Arabidopsis thaliana mutants were identified from previous forward genetic screens. Some identified CBI resistant mutants demonstrated altered cellulose crystallinity, and cell wall saccharification. In a larger crop species, these characteristics would allow for plant cell wall material to be efficiently converted into cellulosic ethanol. Therefore, a forward genetic screen has been carried out in Triticum aestivum, bread wheat. Three CBI resistant mutants have been identified in wheat, and were found to contain point mutations in the wheat ortholog for AtCESA3, TaCESA1. These CBI resistant mutants demonstrated altered cell wall saccharification, and cellulose crystallinity. The identification of CBI resistant mutants in wheat demonstrates that traits identified in A. thaliana can be reproduced in a monocot crop species.
The second focus of this thesis was to develop new herbicide resistant lines in A. thaliana. Indaziflam is a potent herbicide used to control annual grasses and broadleaf weeds. To better understand the plant pathways affected by indaziflam, a forward genetic screen for indaziflam resistance was completed in A. thaliana. Approximately 750, 000 A. thaliana seeds were screened for indaziflam resistance, and only one allele, indaziflam resistant 1 (izr1), was identified to cause weak indaziflam resistance. Positional cloning coupled with next-generation sequencing revealed that a point mutation in the CULLIN1 (CUL1) encoding gene caused the decrease in indaziflam sensitivity. CUL1 is an E3 ligase involved in a variety of plant signalling pathways, including auxin response. Along with decreased sensitivity to indaziflam, izr1 seedlings demonstrated reduced sensitivity to auxin mimicking herbicides. Comparing izr1 to a known auxin resistant CUL1 mutant, cul1-6, and the known CBI resistant CESA mutant, ixr1-1, revealed that alterations to the CUL1 protein or CESA3 can affect indaziflam sensitivity.


title: Optimization of plastic scintillator thicknesses for online beta detection in mixed fields

subject:
Plastic scintillation detectors
Monte Carlo radiation transport
MCNPX code
Efficiency
Whole body monitor
Beta
Gamma

abstract: For efficient beta detection in a mixed beta gamma field, Monte Carlo simulation models have been built to optimize the thickness of a plastic scintillator, used in whole body monitor. The simulation has been performed using MCNP/X code and different thicknesses of plastic scintillators ranging from 150 to 600 um have been used. The relationship between the thickness of the scintillator and the efficiency of the detector has been analyzed. For 150 m thickness, an experimental investigation has been conducted with different beta sources at different positions on the scintillator and the counting efficiency of the unit has been measured. Evaluated data along with experimental ones have been discussed. A thickness of 300 um to 500 um has been found to be an optimum thickness for better beta detection efficiency in the presence of low energy gamma ray.


title: The synthesis and in vitro evaluation of siRNAs modified at the backbone with a novel triazole-based internucleotide linkage and abasic alkyl-chain linkages of varying length

subject:
Nucleic acids
SiRNA
Click chemistry
Triazole
Backbone

abstract: For over a decade, the use of double-stranded short interfering RNAs (siRNAs) to silence the expression of genes associated with disease at the translational level has gained much attention. Using a highly conserved endogenous pathway within cells, siRNA technology displays a high degree of target specificity and potency. However, traits required for the successful design of siRNA-based therapeutics such as resistance to nuclease-mediated degradation, improved cell membrane permeability and reduced off-target toxicity, are compromised by the native structure of duplex RNA′s charged backbone. This study therefore focused on synthesizing novel and neutrally-charged triazole-linked nucleoside dimer analogs which were incorporated throughout siRNA duplexes using DMTphosphoramidite chemistry, in order to attenuate the negative contributions of RNA′s native backbone. In order to further elucidate the mechanism of the RNA interference (RNAi) pathway, additional siRNAs were synthesized containing commercially available abasic alkyl spacers. Through the robust copper(I)-catalyzed Huisgen [3+2] cycloaddition, azide and alkyne nucleic acid monomers were joined through the heterocyclic linkage in nearly quantitative yields, producing the novel triazole-linked uracil-uracil (UtU) and cytosine-uracil (CtU) dimers. Results from cell-based assays indicate that triazole-modified siRNAs are capable of silencing the transiently-expressed reporter gene firefly luciferase and the endogenous gene glyceraldehyde-3-phosphate dehydrogenase (GAPDH) in a dose-dependent manner. In addition, modifying the 3′- overhangs of siRNAs with the triazole backbone linkage, gave rise to increased nuclease resistance well beyond that of wild-type siRNA. Duplex RNAs containing abasic spacer linkages in the sense strand also maintained activity while targeting the luciferase reporter gene, indicating the capability to tune the efficacy of siRNA constructs by altering their thermodynamic profiles, in addition to providing evidence for an alternative RNAi mechanism. The studies describe herein, emphasize the compatibility of these novel backbone modifications with Watson-Crick interactions and with the RNA pathway.


title: A nonlinear and nonlocal model for animal aggregation

contributor:
van Veen, Lennaert
Buono, Luciano

subject:
Aggregation model
Saturation function
Partial differential equation

abstract: An aggregation model is a kind of model used to show the dynamics of the distribution of the population of organisms. Mathematically, we can use a partial differential equation to model the density of an organism at different times and locations. In this paper, we are going to look at a 2+1-dimensional nonlinear and nonlocal aggregation model proposed by Fetecau [8] with an adaptation of a saturation function to the nonlinear term. The nonlinear term represents the interaction between an individual and its neighbours. The saturation function can suppress or amplify the interaction at a low or high level depending on the values of some parameters in the saturation function. We will explore the behaviour of the model with different saturation functions applied.

abstract: University of Ontario Institute of Technology


title: Intelligent fault diagnosis of gearboxes and its applications on wind turbines

subject:
Vibration analysis
Fault detection
Fault semantic network
Evolutionary optimization

abstract:
The development of condition monitoring and fault diagnosis systems for wind turbines has received considerable attention in recent years. With wind playing an increasing part in Canada’s electricity demand from renewable resources, installations of new wind turbines are experiencing significant growth in the region. Hence, there is a need for efficient condition monitoring and fault diagnosis systems for wind turbines. Gearbox, as one of the highest risk elements in wind turbines, is responsible for smooth operation of wind turbines. Moreover, the availability of the whole system depends on the serviceability of the gearbox.
This work presents signal processing and soft computing techniques to increase the detection and diagnosis capabilities of wind turbine gearbox monitoring systems based on vibration signal analysis. Although various vibration based fault detection and diagnosis techniques for gearboxes exist in the literature, it is still a difficult task especially because of huge background noise and a large solution search space in real world applications. The objective of this work is to develop a novel, intelligent system for reliable and real time monitoring of wind turbine gearboxes. The developed system incorporates three major processes that include detecting the faults, extracting the features, and making the decisions. The fault detection process uses intelligent filtering techniques to extract faulty information buried in huge background noise. The feature extraction process extracts fault-sensitive and vibration based transient features that best describe the health of the gearboxes. The decision making module implements probabilistic decision theory based on Bayesian inference. This module also devises an intelligent decision theory based on fuzzy logic and fault semantic network.
Experimental data from a gearbox test rig and real world data from wind turbines are used to verify the viability, reliability, and robustness of the methods developed in this thesis. The experimental test rig operates at various speeds and allows the implementation of different faults in gearboxes such as gear tooth crack, tooth breakage, bearing faults,
iv
and shaft misalignment. The application of hybrid conventional and evolutionary optimization techniques to enhance the performance of the existing filtering and fault detection methods in this domain is demonstrated. Efforts have been made to decrease the processing time in the fault detection process and to make it suitable for the real world applications. As compared to classic evolutionary optimization framework, considerable improvement in speed has been achieved with no degradation in the quality of results. The novel features extraction methods developed in this thesis recognize the different faulty signatures in the vibration signals and estimate their severity under different operating conditions. Finally, this work also demonstrates the application of intelligent decision support methods for fault diagnosis in gearboxes.


title: Single-stage boost integrated asymmetrical half-bridge AC-DC power converter with dual modulation for indoor led lighting

subject:
LED driver
Eliminating electrolytic capacitor
120Hz ripple regulation
Single stage converter
Power factor improvement

abstract: Light emitting diodes (LEDs) for indoor lighting is a promising technology which can lead to major energy saving and cost reductions. The major concerns of improving power factor and regulating the output current ripple with regards to LED drivers has been addressed in this thesis by using dual modulation in a single stage AC/DC power converter. The dual modulation has been achieved through novel controls schemes. Various decoupling control strategies has been proposed. Dual modulation also helps in eliminating the need of bulk electrolytic output capacitors hence enhancing the life time of power supplies. The thesis also includes optimizing the DC link voltage. Design of magnetics for the converter has been carried out. Analytical and simulation results are presented as the proof of concept.


title: Towards low dose retrospective dosimetry on shelled species

subject:
EPR dosimetry
Retrospective dosimetry
Alanine powder
Calcified tissues
Mn2+

abstract: This work investigates calcified tissues of shelled species for retrospective dosimetry using electron paramagnetic resonance (EPR) spectroscopy. To determine applicable samples for low dose studies, shells of crustacean and mollusc species were irradiated to 10 Gy using a 137Cs source. Reference dosimetry was performed with alanine powder using a specifically developed calibration curve. Characteristic Mn2+ signals were present in the EPR spectra of all studied species. Radiation induced peaks were not detected in shells of any species except terrestrial snails. A dose-response curve for terrestrial snails was developed by irradiating shells to 2, 10, and 20 Gy. However, Mn2+ signals caused limitations in resolving radiation induced peaks below 2 Gy. Environmental factors were assessed, and it was found that shell structure and habitat characteristics contribute to Mn2+ signals in EPR spectra. Since high-intensity Mn2+ signals obscured radiation-induced peaks, shells of the studied aquatic species were deemed unsuitable for low dose retrospective dosimetry.


title: Linear regression model for continuous non-invasive blood pressure estimation for an ICU setting

subject: Intra-arterial blood pressure monitoring

subject: Pulse transit time

subject: Heart rate

subject: Gender

subject: Age

abstract: Continuous blood pressure (BP) monitoring in critically ill patients is crucially important for clinicians. The gold standard intra-arterial method is complicated and contraindicated. Current pulse transit time (PTT)-based BP estimation methods are validated on healthy subjects using intermittent cuff-based BP measurements. Research indicates significant differences in invasive and noninvasive BP recordings in critically ill patients. Research also indicates BP variations due to clinical condition induced heart rate changes and gender and age differences. Comprehensively addressing all these issues, a novel, continuous non-invasive BP estimation model with age, gender and heart rate as covariates along with PTT to estimate ICU patient invasive BP data is presented in this pilot-study. The proposed novel model is tested for four common ICU clinical conditions. The results indicate compliance with the Association for Advancement for Medical Instrumentation standards, thus providing a potential solution for the underlying risk-factors associated with the conventional method.