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Catalytic Requirements for Removing Kinetic Bottlenecks and Enabling Cascade Reactions in Alkanol C-H and C-O Bond Activation on Bifunctional Metal Oxides
Get PDFBifunctional metal oxide catalysts (e.g., supported VOx and CuOx) contain redox and acid sites that work in tandem for alkanol upgrading to value-added esters or acetals. Enabling these cascade reactions, by removing the kinetic bottlenecks of C-H or C-O bond scission, requires a detailed knowledge of the redox and acid site strength, and how to manipulate this strength. This thesis establishes the mechanistic origins of redox and acid site strength by decoupling the two functionalities and probing their intrinsic reactivity descriptors, related to changes in catalyst structure through tuning domain size, support identity, metal identity, and metal oxidation state. Chemical titrants act as probes for active site strength: for Lewis acid sites, pyridine adsorption enthalpies prescribe 2-butanol dehydration rates from acidic (Al2O3) to basic (ZnO) oxides, and for redox sites, H2 activation enthalpies prescribe alkanol oxidative dehydrogenation (ODH) rates for VOx on irreducible (SiO2) to reducible (TiO2) supports. The identity of the metal-lattice oxygen coordination environment dictates its reactivity, where for supported VOx, ODH turnover rates increase with smaller domains and more reducible supports, predominantly from sites at the V-O-support interface, confirmed for ODH reactions with methanol, ethanol, 2-butanol, cyclohexanol, and benzyl alcohol reactants. With decreasing oxygen chemical potential, metal oxides reduce to lower states, and for VOx and CuOx this drastically hinders their alkanol C-H rates in ODH reactions. For the case of CuOx, a complete reduction to metallic Cu0 states means ODH mechanisms shift to their anaerobic equivalents that evolve H2; in this phase transition, metastable nanoparticles with strained Cu0 active sites are more effective for C-H scission than bulk Cu0. Strained copper active sites form in both steady state and transient conditions, the latter due to intraparticle lattice oxygen diffusion limitations that form oxide core-metal shell nanoparticles. Taken together, these studies give an atomistic scale understanding of alkanol C-H and C-O bond activation on the redox and acid sites of bifunctional metal oxide catalysts.Ph.D
Application of Riemann Solver Based Flux Functions to Large-Eddy Simulation of Subsonic Turbulent Flows
Get PDFA density-based high-order Central Essentially Non-Oscillatory (CENO) Godunov-type finite-volume scheme in combination with low-dissipative Riemann solver based numerical flux functions is applied to both low- and moderate-Mach number compressible turbulent subsonic flows. In particular, implicit large-eddy simulation results are obtained by the numerical solution of the Favre-filtered compressible Navier-Stokes equations for the canonical Taylor-Green vortex (TGV) flow and decay of homogeneous isotropic turbulence (HIT) problems. These results are compared to both direct numerical simulation (DNS) as well as to available experimental data. For the low-Mach number essentially incompressible TGV and HIT flows, DNS results are obtained through the implementation of a pseudo-spectral Fourier-Galerkin solver on triply periodic cubic computational grids containing up to 2,048^3 nodes, while published data is used as a means of comparison for compressible flow simulations at the moderate Mach numbers considered in this research. For the TGV flow, the CENO scheme is shown to outperform the standard second-order finite-volume scheme by achieving lower error in peak enstrophy at a significantly reduced computational cost. Additionally, modified variants of the standard Roe flux, specifically low-Mach Roe (LMRoe) and L2Roe, showed significant reduction in numerical dissipation as evidenced by increased peak enstrophy for the TGV flow problem and a significantly improved -5/3 slope when compared to the standard Roe flux for the decay of both incompressible and compressible HIT. For all the LES results obtained for the HIT test cases, using both second- and high-order finite-volume schemes, the decay of kinetic energy matched the expected t^(-1.25) result and no stability issues were encountered. The expected drain of energy is captured by the implicit filtering strategy without the use of an explicit sub-grid model.M.A.S
Ectropion Repair Techniques and the Role of Adjunctive Superotemporal Skin Transposition for Tarsal Ectropion
Get PDFBackground: Ectropion is a common eyelid problem and is defined as eversion of the eyelid margin and typically involves the lower eyelid. The main acquired causes of ectropion include involutional, cicatricial, paralytic, and mechanical. A severe manifestation of ectropion is tarsal ectropion, where much of the tarsal conjunctiva is visible, often with keratinization of the conjunctiva. causes. Common techniques for ectropion repair include horizontal tightening of the lid with lateral tarsal strip or Bick procedure, lateral tarsorraphy, inverting sutures and the sub-orbicularis oculi fat lift. However, all surgical techniques are prone to ectropion recurrence. We review the techniques for ectropion repair and describe a novel adjunctive technique called the superotemporal skin transposition (STS), which is well suited for patients with recurrent or tarsal ectropion. Methods: The STS is combined with a lateral tarsal strip or Bick procedure. For the STS, all of the anterior lamellae of the lateral lower lid is retained. The posterior lamellae is sutured to the lateral orbital tubercle. A triangular bed of skin is excised superotemporally, and the lower lid anterior lamellae is transposed and secured with multiple sutures. The STS can be combined with inverting sutures, or skin graft for cicatricial cases. Results: We used the STS with Bick procedure and optional inverting sutures on 23 patients, 4 of whom required bilateral ectropion repair. At 1–6 month followup all patients achieved satisfactory outcomes with a well-positioned eyelid and improved symptoms. The STS had more lateral cutaneous scarring than with a Bick procedure alone, but patients did not find this objectionable. No reoperations were required. Conclusion: The STS is a straightforward and useful adjunct for patients with severe, recurrent or tarsal ectropion. Further studies are needed to determine the long-term efficacy of this technique
Mediating Innovation Policy Delivery: The Regional Innovation Centres of Ontario
Get PDFReport cards and academic scholarship have been critical of innovation policy in Canada. But what if these reports have done a profound injustice to the story of knowledge-driven economic reinvention and the actual transformation taking place in the country?
Spotlighting what is happening in cities and regions across Ontario, Mediating Innovation Policy Delivery argues that it is far more nuanced and exciting than what has been captured in scorecards and report cards. The book explores the intermediary institutions, the organizational brokers at the frontline of Canada’s innovation race, that are shepherding the process of economic reinvention in regions large and small.
The book draws on case studies to explore three central themes. The first is about innovation, innovation policy, and their delivery systems. The second is that of regions as the frontlines of technological and socioeconomic change in the Canadian federation. The third covers the role of intermediary institutions as innovation platforms, highlighting their triumphs and tribulations as they strategically navigate through the shifting currents of change. The book’s main lessons apply not just to Ontario and Canada but also to other industrialized democracies worldwide. Ultimately, the book advances our knowledge of organizational instruments of innovation policy delivery that operate at the strategic interface between the state, market, and society.
Using Ontario as a case study, this book sheds light on the delivery of innovation policy in politically complex environments
Ion Manipulation from Liquid Xe to Vacuum: Ba-Tagging for a nEXO Upgrade and Future 0νββ Experiments
No full textNeutrinoless double beta decay (0νββ) provides a way to probe physics beyond the Standard Model of particle physics. The upcoming nEXO experiment will search for 0νββ decay in 136Xe with a projected half-life sensitivity exceeding 1028 years at the 90% confidence level using a liquid xenon (LXe) Time Projection Chamber (TPC) filled with 5 tonnes of Xe enriched to ∼90% in the ββ-decaying isotope 136Xe. In parallel, a potential future upgrade to nEXO is being investigated with the aim to further suppress radioactive backgrounds and to confirm ββ-decay events. This technique, known as Ba-tagging, comprises extracting and identifying the ββ-decay daughter 136Ba ion. One tagging approach being pursued involves extracting a small volume of LXe in the vicinity of a potential ββ-decay using a capillary tube and facilitating a liquid-to-gas phase transition by heating the capillary exit. The Ba ion is then separated from the accompanying Xe gas using a radio-frequency (RF) carpet and RF funnel, conclusively identifying the ion as 136Ba via laser-fluorescence spectroscopy and mass spectrometry. Simultaneously, an accelerator-driven Ba ion source is being developed to validate and optimize this technique. The motivation for the project, the development of the different aspects, along with the current status and results, are discussed here
S-ETEG Guidance on LAC Requirements for Harvesting Theses and Dissertations Release 1.0
Get PDFThe recommendations developed by the LAC harvesting sub-group of the Scholaris Electronic Theses and Dissertations Expert Group (S-ETEG) provide guidance to Scholaris participants on meeting Library and Archives Canada (LAC) requirements for harvesting theses and dissertations from an institutional repository hosted in the Scholaris technical environment. The document also recommends changes to the default DSpace 7.x metadata registry and ETDMS crosswalk that must be implemented in order to meet LAC requirements
A Collection of Upper Egyptian Predynastic Ceramics from the ROM: the Potential of Legacy Collections for Egyptian Ceramic Analysis
Get PDFCeramics are among the most abundant artifacts recovered from archaeological excavations and have long served as chronological markers and proxies for understanding social phenomena. In Predynastic Egyptian archaeology, ceramic seriation has been instrumental in constructing relative chronologies and identifying cultural and social boundaries during this formative period of Egyptian civilization. However, the universal application of these typologies often overshadows regional variation. This study applies a methodology situated in the chaîne opératoire to analyze Predynastic ceramics from the Royal Ontario Museum's collection from three Upper Egyptian sites: Abydos, el-Amra, and Armant. By critically applying standardized classification systems, including Petrie’s typology and the Vienna System for fabric analysis, this research identifies local variations in production sequences and technical traditions and identifies future areas of research for Predynastic ceramic fabric analysis. The findings reveal nuanced regional differences in ceramic technology and highlight the potential for legacy collections to contribute new data to refine existing classification systems and chronological frameworks.M.A
Sensory Dysfunction in ALS and Other Motor Neuron Diseases: Clinical Relevance, Histopathology, Neurophysiology, and Insights from Neuroimaging
Get PDFBackground: The clinical profiles of MNDs are dominated by inexorable motor decline, but subclinical proprioceptive, nociceptive and somatosensory deficits may also exacerbate mobility, dexterity, and bulbar function. While extra-motor pathology and frontotemporal involvement are widely recognised in motor neuron diseases (MNDs), reports of sensory involvement are conflicting. The potential contribution of sensory deficits to clinical disability is not firmly established and the spectrum of sensory manifestations is poorly characterised. Methods: A systematic review was conducted to examine the clinical, neuroimaging, electrophysiology and neuropathology evidence for sensory dysfunction in MND phenotypes. Results: In ALS, paraesthesia, pain, proprioceptive deficits and taste alterations are sporadically reported and there is also compelling electrophysiological, histological and imaging evidence of sensory network alterations. Gait impairment, impaired dexterity, and poor balance in ALS are likely to be multifactorial, with extrapyramidal, cerebellar, proprioceptive and vestibular deficits at play. Human imaging studies and animal models also confirm dorsal column-medial lemniscus pathway involvement as part of the disease process. Sensory symptoms are relatively common in spinal and bulbar muscular atrophy (SBMA) and Hereditary Spastic Paraplegia (HSP), but are inconsistently reported in primary lateral sclerosis (PLS) and in post-poliomyelitis syndrome (PPS). Conclusions: Establishing the prevalence and nature of sensory dysfunction across the spectrum of MNDs has a dual clinical and academic relevance. From a clinical perspective, subtle sensory deficits are likely to impact the disability profile and care needs of patients with MND. From an academic standpoint, sensory networks may be ideally suited to evaluate propagation patterns and the involvement of subcortical grey matter structures. Our review suggests that sensory dysfunction is an important albeit under-recognised facet of MND
Genomic Profile and Clinical Outcomes in Acute Myeloid Leukemia with Monosomal Karyotype
Get PDFThe biology of Monosomal Karyotype Acute Myeloid Leukemia (MK AML) remains unclear, and its mutational profile has not been exclusively assessed. We sought to determine the genomic profile of MK AML patients and its correlation with overall survival (OS). We conducted a retrospective study involving 664 AML patients, identifying 156 (23.5%) with MK AML. The most common monosomies were -17 (41%) and -7 (37%), with 149 (95%) and 138 (88%) having myelodysplasia-related (MR) cytogenetics and complex karyotype (CK), respectively. Frequent mutations included TP53 (69%), DNMT3A (19%), TET2 (13%), and IDH1 (7%). Patients with MK AML with TP53 mutation (TP53 Mut) had shorter OS compared to those with TP53 wild-type (WT) (median OS, 3.9 versus 9.2 months, p = 0.002). Our validation study further supports this finding. There was no significant difference in OS related to the presence or absence of CK (p = 0.252), MR mutations (p = 0.252), DNMT3A (p = 0.264), TET2 (p = 0.264), and IDH1 (p = 0.183) alterations. Co-mutation with novel EPI6 and TAZI signature alterations did not significantly impact OS among MK AML TP53 Mut patients, suggesting that TP53 Mut remains the dominant driver of outcome in this subgroup. In conclusion, MK AML is a genotypically diverse and high-risk group, with MK AML TP53 Mut indicating worse prognosis
Artificial Intelligence in Scholarly Publishing
Get PDFSlides presented at Student Journal Forum, February 18-20, 2025.
Presenters from: Libraries and Cultural Resources, University of Calgary
Session recording is available at: https://play.library.utoronto.ca/watch/0218054bfb66866c7c5c4da55bd7a94dIn this session, we will introduce the basics of machine learning and AI and then discuss some of the key issues that peer reviewers and editorial teams must consider when using AI tools (or not) in the publishing process