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Fabrication of Vanadium Dioxide Thin Films and their Structural, Optical and Electrical Characterization for Optoelectronic Applications
Get PDFVanadium dioxide (VO2) is a transition metal oxide that is well known for its metal-to-insulator phase transition (MIT). One of the most common forms of VO2 that has been generally studied is the thin film form. VO2 thin films are considered a strong candidate in various new-generation optical, electronic, and optoelectronic (photonic) applications. From the technology perspective, the fabrication of single-crystal VO2 thin films appears to be challenging. Up to now, research on the preparation of VO2 thin films has focused on employing different material fabrication techniques to produce high-quality VO2 thin films. The stoichiometry and quality of VO2 thin films strongly depend on the fabrication process. There is still a need to study the production of near-single-crystal, high-quality VO2 thin films and their structural, optical and electrical characterization. Secondly, the metal-to-insulator phase transition phenomenon in VO2 is a topical research field. The percolation theory has introduced some rigor in explaining the phase transition. This dissertation focuses on two aspects of research on VO2 thin films. The first aspect focuses on studying the effect of specific deposition parameters such as substrate biasing and substrate temperature on the quality of VO2 thin films. Also, the synthesis of high-quality VO2 thin films prepared on single-crystal silicon, quartz and sapphire substrates is investigated. The films are examined using various analysis techniques including Raman spectroscopy, scanning electron microscopy (SEM), x-ray diffraction (XRD), x-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM) and energy-dispersive x-ray spectroscopy (EDS). The optical constants, namely the refractive index (n) and the extinction coefficient (K), and the optical bandgap (Eg) of the films are extracted using the Swanepoel and Manifacier techniques. The second aspect of this dissertation covers the application of percolation theory on the phase transition in VO2 thin films. Accordingly, the topology of conducting clusters during the IMT and MIT is investigated by means of optical and electrical switching in a high-quality VO2 thin film. Additionally, self-heating-induced electrical and optical switching in VO2 thin films prepared on sapphire substrates under constant applied current pulses has been studied. The difference in the two switching dynamics is explained by a simple model based on the percolation theory
ON DEVELOPING AN ADAPTIVE DESIGN METHODOLOGY AND ITS APPLICATIONS TO VENTILATORS TO FILTER CORONAVIRUS
No full textThe abstract of this item is unavailable due to an embargo
Beyond More Houses: A Multimethod Secondary Analysis of Federal Housing Programs, Household Crowding, and Health in First Nations Communities in Saskatchewan
Get PDFHousing is a social determinant of health and specific equity concern for First Nations Peoples living on-reserve in Canada. Lasting results of discriminatory colonial structures and federal government control on-reserve include challenges with housing quality and quantity. Some First Nations face distressing levels of housing shortages and household crowding. This study was a multimethod secondary analysis of data collected in two community-based research studies with First Nations in Saskatchewan. The main research question was “What relationships exist between federal housing programs, household crowding, and health among First Nations Peoples living on-reserve in Saskatchewan?” Specific sub-questions were “How do First Nations Peoples in two communities in Saskatchewan describe challenges and solutions related to household crowding on-reserve?” and “What is the relationship between household crowding and (a) overall physical health, (b) overall mental health, and (c) chronic and infectious respiratory diseases among First Nations Peoples living on-reserve in two communities in Saskatchewan?” I undertook a qualitative secondary analysis of 34 interviews with First Nations adults living on-reserve to answer the first sub-question, where I identified four themes: (1) designing for kinship, (2) relieving system pressure, (3) planning instead of reacting, and (4) renovating alongside building. I completed a quantitative secondary analysis of interviewer-administered surveys from 831 First Nations adults living on-reserve to answer the second sub-question, where I identified the household crowding measure was significantly associated with chronic bronchitis diagnosis. Integration of findings to answer the overarching research question emphasized that federal housing systems need to change to improve housing status and related health outcomes on-reserve. Suggested federal-level changes include the provision of sufficient and sustained funding and support of First Nations’ control
Indigenous Studies Library Collection Development Toolkit
Get PDFPeer ReviewedThis toolkit is one of the outputs of my 6-month sabbatical in 2022, when I conducted an online survey of librarians' experiences with doing selection for Indigenous Studies materials in academic libraries across Western Canada. This toolkit provides tips and guidelines for doing this type of collection development work, both for those with experience and those who are new to this work, as folks can learn from each other, regardless of their level of experience. This toolkit covers tips for such issues as how to find these materials, the importance of local contexts, whether to select for print or electronic formats, advocacy for funding (if needed), recognizing the interdisciplinarity / multi-disciplinarity of Indigenous Studies, and much more
Improving the Spectral Efficiency of Modulation on Conjugate-Reciprocal Zeros (MOCZ) for Non-Coherent Short Packet Communications
Get PDFFuture internet of things (IoT) applications need to meet the stringent requirements of ultra high reliability and ultra low-latency. To meet the ultra low-latency requirements, the IoT networks will be employing the short data packets for data transmission between the devices. Employing the short data packet communications (SPCs) is not straightforward as there are several design problems related to the SPCs which still remain unsolved.
Since the block length for SPCs is finite; the channel estimation is a challenging problem. This is because the conventionally used known pilot symbols to estimate the channel will severely degrade the spectral efficiency of SPCs. Recently a novel non-coherent modulation technique named as modulation on conjugate reciprocal zeros (MOCZ) was proposed which supports the blind detection of transmitted data, i.e., detection without the knowledge of channel. It is also well known that SPCs suffers from data rate loss as compared to the channel capacity limit. Hence, in this thesis, we aim to increase the spectral efficiency of MOCZ.
We improve the spectral efficiency of MOCZ by proposing a technique named as spectrally efficient modulation on conjugate reciprocal zeros (SE-MOCZ) which combines MOCZ with a technique named as faster than Nyquist (FTN) Signaling. Hence; in SE-MOCZ, we end up transmitting the coefficients of MOCZ, modulated on T-orthogonal pulses, at a rate faster than the Nyquist limit, i.e., τT, instead of T, where 0 < τ < 1. That said, we intentionally introduce inter symbol interference (ISI) between the received samples of SE MOCZ. To partially remove the ISI, we introduce a discrete-time filter at the receiver. We further optimize the radius of complex zeros of SE-MOCZ in the presence of ISI. Simulation results show the gains of proposed SE-MOCZ in terms of spectral efficiency
DEVELOPMENT OF COST-EFFECTIVE FAULT LOCALIZATION PLATFORM FOR UNDERGROUND CABLE SYSTEM
Get PDFThe mining industry is highly dependent on electricity or other forms of energy converted into electricity. Here, one of the common forms of electricity distribution is through underground cables, but the electricity systems regularly confront contingencies due to cable breakdowns or defects. Depending on fault types, detective tools, and cable position, it may take several hours to days to detect the exact fault location with existing methods and tools, which affects the entire mining operation with financial losses and safety issues. Besides, industrial fault localization platforms are very expensive and seldom tailored for the mining industry. To locate such faults, the online fault localization platform has drawn wide attention but is limited in functionalities and applications.
This research aims to develop a cost-effective double-ended online fault localization platform while proposing solutions for data synchronization and accurate traveling wave arrival time detection problems. At first, extensive market research has been done on available platforms to access those platforms’ functionalities and costings. Then, a hardware setup has been developed by combining appropriate sensors, a data acquisition unit, a computational platform, and other necessary components. Furthermore, to establish communication between remote platforms, a Python-based software program has been developed. Besides, query-based server management has been introduced to handle and manage huge amounts of data. Combining the hardware and software, the overall cost of a single platform is CAD $ 2,850.00, which is at least ten times less than the least expensive market option.
The chosen double-ended traveling wave-based online fault localization method requires accurate synchronized time to properly compute the traveling wave arrival time difference. Thus, coordinated universal time alignment of acquired time series data is needed. Global Positioning System (GPS) based universal time synchronization is one of the popular ways. There are several other techniques, but all of these have some practical difficulties and dependencies. To solve this problem, a cost-effective novel zero-crossing point-based data synchronization approach has been proposed. This approach doesn’t rely on GPS receivers or any other existing methods; rather, the measurement is synchronized by calibrating the zero-crossing points of the sinusoid measurements before the fault. In this way, appropriate synchronization has been realized.
The accuracy of traveling wave-based fault localization highly depends on how accurately its arrival times are detected from ends of cable. Accurate detections are achieved when signals sampling rates are high. Usually, a data acquisition system with a higher sampling rate may address the issue, but it increases cost. On the other hand, available interpolation-based up-sampling techniques have several constraints. Machine learning model can solve this problem if trained by real inputs and outputs with desired sampling rates for different types of faults. In this research, a machine learning-based up-sampling model has been presented, which improves the accuracy of traveling wave arrival time detection. Besides, it is cost-effective and outperforms interpolation techniques.
Therefore, the proposed fault localization platform combines all the above solutions, which makes the platform very advance, reliable, and cost-effective
Foraging Habitat Use and Diet Composition of Barn Swallows (Hirundo rustica) and Tree Swallows (Tachycineta bicolor) in Agriculturally Intensive Landscapes of the Northern Prairies
Get PDFBirds that catch insects while in flight, which comprise the guild known as aerial insectivores, have declined sharply over the last 50 years. The causes of these declines are incompletely understood but are hypothesized to relate to changes in aerial insect prey that lead to region- and species-specific changes in productivity and survival. One possible driver of such aerial insect changes is increasing agricultural intensity across the guild’s North American breeding grounds, as practices such as removal of natural habitat and increased insecticide use are known to affect insect communities. In this thesis, I studied the feeding ecology of two aerial insectivore species, Barn Swallows (Hirundo rustica) and Tree Swallows (Tachycineta bicolor), across a gradient of agricultural intensity in the Prairie Pothole Region of Saskatchewan, Canada. I sought to identify whether agricultural intensity affected the foraging behavior and diet of swallows, and to determine whether previously identified foraging differences between these species led them to respond differently to land use intensity. While I intended to also examine dietary insecticide exposure in relation to foraging and diet, this analysis was delayed as COVID-related closures of laboratory facilities prevented blood samples from being processed. Using data derived from GPS tags, I determined that both Barn and Tree Swallows selectively foraged in wetland habitats and avoided cropped habitat. Foraging habitat use was mostly consistent across the agricultural intensity gradient, but maximum foraging distance was affected by agricultural intensity among Tree Swallows but not Barn Swallows. Diet was similar between Barn and Tree Swallows, with both species, and particularly nestlings, frequently consuming emergent aquatic insects. Local wetland cover was a significant predictor of diet composition in both species of swallow, with wetland insecticide pollution also affecting diet among Tree Swallows. Collectively, these foraging and diet results indicate that there is a high degree of similarity in the feeding ecology of Barn and Tree Swallows in this Saskatchewan study system. This study highlights the importance of wetlands and emergent insects to multiple species of farmland-breeding aerial insectivores and indicates that conserving wetland habitats should be a conservation priority in the Prairie Pothole Region
John Milton's Republican Poetics and the Politics of Paradise Lost
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England in the 1640s was torn by civil war between Parliamentarians in pursuit of a free commonwealth and Royalists loyal to the Stuart monarchy of Charles I. Throughout the decade, John Milton turned from poetry to political pamphleteering, attaching his personal calling to the republican cause. During the 1640s, his polemical tracts argued for freedom of expression and liberty from monarchical oppression. In the treatise The Reason of Church Government Urged Against the Prelaty, Milton presented his political writing as preparation for the great national poem he would someday write. After the execution of Charles I and the abolition of the monarchy in 1649, Milton defended regicide and republicanism in The Tenure of Kings and Magistrates, Eikonoklastes, and the two Latin Defenses. However, by the end of the 1650s, the political hopefulness expressed in tracts such as Defensio Secunda was replaced by the poet’s disillusionment over the impending restoration of the monarchy. In 1660 Milton wrote The Readie and Easie Way to Establish a Free Commonwealth, where he criticized his countrymen’s inability to sustain republican rule and pleaded that they acknowledge that reason and law were integral to the construction of the English commonwealth.
My thesis argues that the interplay of reason, law, and human will is also central to Milton’s post-Restoration epic, Paradise Lost. Nevertheless, many critics see the epic as the poet’s retreat from politics. My research demonstrates that Paradise Lost is not a work that signals Milton’s withdrawal from active political engagement; rather, the poem reflects the poet’s continued commitment to evaluating the country’s political challenges and addresses twenty years of republican potential, upheaval, tyranny, and disintegration. My dissertation provides a systematic analysis of specific episodes in Paradise Lost and takes into consideration their relationship with the political and theological views of Milton expressed in his polemical tracts during the civil war, Interregnum, and Restoration. I argue that the political debates in Heaven and Pandemonium, the exchanges between Adam and Eve in the Garden, and Adam’s visions and Michael’s instruction reflect Milton’s commitment to a free commonwealth over monarchical tyranny, his disillusionment with his contemporaries, and his belief in the educability of the English people
IMPACT OF COVID-19 ON FOOD PRICES IN REMOTE INDIGENOUS COMMUNITIES- THE CASE OF FOX LAKE IN LITTLE RED RIVER CREE NATION (LRRCN).
Get PDFRecent studies suggest significant increase in food prices due to the Covid-19 pandemic in Indigenous communities across Canada and the US. This study investigates whether and to what extent food prices might have changed in response to the Covid-19 pandemic using Fox Lake, a remote community within Little Red River Cree Nation in Northern Alberta, as an interesting case study. The study uses retail price data for selected food items from Fox Lake’s local store, The Northern, and respective retail prices for similar products in Alberta, over a five-year period from 2017 to 2021. The study is guided by three specific objectives. First, it investigates disparities in price levels and temporal price changes between Fox Lake and Alberta. Second, the study assesses the extent to which temporal changes in food prices may have been driven by Covid-19 in Fox Lake in comparison to respective changes at provincial level. Finally, the study examines the implications of potentially higher food prices on the living wage requirements for Fox Lake households.
Results show that between 2017 and 2022, Fox Lake's prices for selected food items were up to 175% and 186% higher than in Alberta, particularly for food items like canned tuna and margarine respectively. Food prices in Fox Lake, however, did not soar during the pandemic. On average prices increased by 1.1% in Fox Lake, which is three times lower than the average food price increase in Alberta. The thesis’ findings are, hence, in contrast to significant price surges of 400%, observed during the Covid-19 pandemic e.g., in northern Ontario. Nevertheless, a modest 1.1% increase in food prices would increase annual food expenses by 19.58 to $19.63 for a family of four with two working members
3D Printed Polycaprolactone/Nano-Hydroxyapatite Scaffolds for Bone Tissue Engineering In-Vitro
No full textThe abstract of this item is unavailable due to an embargo