VictorJuiz/thesis huggingface dataset:
Metal-Organic Frameworks of Pyrazolate Derivatives: Synthesis and Applications for Chemical Sensing, Gas Separation, and Catalysis
Keywords: Catalysis
Gas Separation
Luminescence
Metal-Organic Frameworks
MOFs
Volatile Organic Compound Sensing

In this work we examine the structure and applications of metal-organic frameworks (MOFs) synthesized from pyrazolate derivatives. In total, six pyrazolate ligands were examined: 4-(4-(3,5-dimethyl-1H-pyrazol-4-yl)phenyl)pyridine (HL), 1,1’-methylenebis(3,5-dimethyl-1H-pyrazolyl-4-carboxylic acid) (H2BPM), triethyl-1,1',1''-methanetriyltris(3,5-dimethyl-1H-pyrazole-4-carboxylate) (TPM-1), triethyl-4,4',4''-(methanetriyltris[3,5-dimethyl-1H-pyrazole-1,4-diyl])tribenzoate (TPM-2), 1,1',1'',1'''-(propane-1,1,3,3-tetrayl)tetrakis(3,5-dimethyl-1H-pyrazole-4-carboxylic acid) (H4TPP), tetraethyl-1,1',1'',1'''-(1,4-phenylenebis[methanetriyl]) tetrakis(3,5-dimethyl-1H-pyrazole-4-carboxylate)pyridinephenylpyrazole (TPX). These ligands were used to synthesize a variety of MOFs that were subsequently investigated for luminescent sensing, gas storage, and catalytic performance. In Chapter 2, three MOFs synthesized from the reaction of HL and CuX (X = Br, I) were investigated. These materials were found to form MOFs which contained the luminescent trinuclear Cu(I) pyrazolate unit. Only CuBr and HL alone resulted in a MOF of sufficient purity and stability to permit evaluation as a luminescent sensor. Experiments with various volatile organic compounds revealed turn-on (luminescence enhancement) behaviour for ethyl acetate, pentane, and benzene and turn-off (luminescence quenching) behaviour for diethyl ether and chloroform for this material. In Chapters 3 and 4, ten MOFs are described. These were synthesized from H2BPM and metal-acetate salts. Chapter 3 encompassed two MOFs: [Ni(BPM)]n∙xDMSO and [Cd(BPM)]n∙xDMSO. These MOFs are isostructural, microporous materials. Evacuation of the pores led to collapse of the [Cd(BPM)]n∙xDMSO material but [Ni(BPM)]n∙xDMSO proved to be permanently porous. Further investigations revealed [Ni(BPM)]n∙xDMSO selectively adsorbed methane over nitrogen indicating it may serve as a porous material for coal mine methane capture. Chapter 4 investigated the many other structures H2BPM can assume in the presence of manganese, cobalt, iron, copper, and europium. Cobalt in particular proved highly tunable with 4 separate structures being synthesized such as [Co2(BPM)2(H2O)4(Bpy)0.5]n∙2DMF∙2(H2O). This was achieved through varying the synthetic conditions. [Co2(BPM)2(H2O)4(Bpy)0.5]n∙2DMF∙2(H2O)and [Eu(BPM)(OAc)]n were further investigated for the oxidation of olefins and luminescence respectively. In Chapter 5, metal complexes Mo(TPM-1)(CO)3, Mo(TPM-2)(CO)3, Pd2(H4TPP)Cl4, and Pd2(TPX)Cl4 were synthesized. The catalytic performance of Mo(TPM-1)(CO)3 was evaluated and found to be effective for the oxidation of olefins. MOF synthesis was attempted with all four compounds but was ultimately unsuccessful. Although one MOF was produced from Mo(TPM-1)(CO)3, large scale synthesis was not possible preventing full investigation of its properties.
SMELT DROPLET-WATER INTERACTION IN THE KRAFT RECOVERY BOILER DISSOLVING TANK
Keywords: Dissolving Tank
Kraft Recovery
Recovery Boiler
Smelt
Vapor Explosion

In the dissolving tank of a recovery boiler, violent interaction between smelt droplets and water can cause the tank to rumble and tremor, and in severe cases, a dissolving tank explosion accident. A laboratory apparatus was constructed to visualize smelt droplet-water interaction with high speed imaging, and to examine the effects of various dissolving tank operating parameters on the explosion characteristics of synthetic smelt droplets composed of sodium carbonate and sodium chloride. The results show that smelt droplets are more likely to explode when 1) the water temperature is low, 2) the smelt composition approaches the eutectic composition, 3) the droplet size is large, and 4) there is an external disturbance. Experiments were also conducted using real kraft smelt and green liquor. The results show that real smelt behaves in a similar manner as synthetic smelt, and that replacing water with green liquor promotes droplet explosions. A 1-D heat transfer model of smelt droplet-water interaction was also developed to explain the explosion mechanism. The modeling results suggest that whether a droplet explodes or not depends on the thickness of the solidified layer formed on the smelt droplet surface at the moment the vapor film around the droplet collapses. Experimental results from this study also show that explosions that occur on the water surface generate less sound and tank vibration than explosions that occur beneath the water surface, and that droplet explosions promote smelt dissolution. To improve dissolving tank safety and efficiency, it is important to avoid accumulation of a large amount of smelt in the dissolving tank.
Organic Electrode Materials for Energy Storage Devices
Keywords: Energy storage
Lithium ion batteries
Organic Electrodes
Organic Electronics
Supercapacitors

This thesis describes the design of organic electrode materials for energy storage devices and the investigation into the underlying structure-property relationships governing the performance of these materials. Chapter 1 serves as a general introduction to energy storage devices, the use of organic electrodes in these devices, the factors governing the performance, and the quantification thereof. The characteristics and fundamentals of different types of energy storage devices and the electrochemical properties of suitable materials for each are discussed. Chapter 2 examines the use of a polyfullerene material for supercapacitor applications. I find that the polyfullerene has a favourable redox potential and a high capacity that affords a high power supercapacitor, although, its cycling stability is limited. Examining the performance of the polyfullerene under different conditions, a key degradation mechanism is elucidated that can be used as a guideline to develop stable supercapacitor materials. In Chapter 3, I describe the development of a biologically-derived pendant polymer cathode material for lithium-ion batteries. The polymer is derived from riboflavin (Vitamin B2) and uses a polynorbornene backbone. The polyflavin material affords a high capacity, but the cycling stability is limited. Using a combined theoretical and experimental approach, a new degradation mechanism is uncovered that can be applied to organic electrode materials in general and the design criteria to develop highly stable materials is further refined. Chapters 4 and 5 investigate triptycene-based frameworks for lithium-ion batteries. A cathode material is studied in Chapter 4, and an anode material in Chapter 5. Here, I draw conclusions on the utility of triptycene frameworks for electrode materials in lithium-ion batteries based on the material properties. Specifically, I find that the nature of the linker units is important for the performance of these materials. Choosing the correct linker to form a material with high crystallinity and small aggregate size yields an electrode with excellent stability and high usage of active material. Chapter 6 serves as a summary of this thesis, provides an outlook on the future of organic electrode materials for energy storage, and suggests future directions that the field should take to develop high performance materials.
Ultrasound Characterization of Upper Fibers of Trapezius Muscle in Healthy and Myofascial Neck Pain
Keywords: Myofascial Pain
Trapezius muscle
Ultrasound

Myofascial pain syndrome (MPS) is a common, nonarticular musculoskeletal disorder, characterized by myofascial trigger points (MTrPs). The clinical detection of MTrPs has poor inter-rater reliability. Ultrasound imaging could provide reliable and objective information. Therefore, the overall purpose was to assess the attributes of ultrasound of the trapezius muscle in patients with MPS and potential discriminative ability. Quantitative B-mode ultrasound characteristics for the healthy trapezius muscle using blob area, count and mean echo intensity (EI) was demonstrated to provide differences between healthy and patients with regional neck pain. 98.55% of the overall variance was explained by the median blob area, mean blob count and mean EI. These results provide robust discriminative ability using these measures between clinically apparent regional neck pain and healthy muscle. Subsequently, texture analysis was used to evaluate the upper trapezius muscles of healthy volunteers, and patients who fulfilled the clinical criteria of latent MTrP and active MTrP. Principal component analysis (PCA) demonstrated twelve components accounting for 92.8% of the cumulative variance. Some texture features with highest loading included: energy 45 and 135 degrees (co-occurrence direction), maximum probability 90 degrees, cluster shade 0 and 45 degrees, cluster prominence 0 degrees, dissimilarity average, difference entropy average, inverse difference, information measure 1 90 degrees, correlation 45 and 90 degrees, information measure 2 average. Based on multivariate analysis of variance (MANOVA), significant between group differences (P
Confronting Antigay Prejudice
Keywords: Attitudes
Confrontation
Intergroup relations
Prejudice
Sexual prejudice
Stereotyping

Confrontation of prejudice may be socially costly to confronters, leading to them being disliked for their actions. Moreover, it appears that confronting antigay prejudice specifically bears an additional cost for males: people may question their sexual orientation following their confrontation. Relatedly, heterosexual males report being concerned with having their sexual orientation misclassified were they to confront antigay prejudice. This may act as a mental barrier to confrontation, leading them to remain silent in the face of blatant prejudice. Given that antigay prejudice remains rampant and that heterosexual people seem to be the most effective confronters of antigay prejudice, it is important to find ways to reduce their legitimate fears and help them confront. This program of research included five studies to further investigate confrontation of antigay prejudice in order to solidify and expand previous knowledge about its costs, as well as test different interventions aimed at removing barriers to confrontation and increasing confrontation by heterosexual people. Studies 1-2 sought to replicate previous findings in new social contexts and found that, across different situations, sexual orientation perception biases constitute a recurring cost for male confronters of antigay prejudice. Study 3 examined the efficacy of different confrontation tactics in response to varied bigoted comments and found that confronting clear bigotry using a suggestive tone and avoiding prejudice labels such as â homophobicâ led to better outcomes for confronters than confronting ambiguous bigotry with a personal attack using labels. Study 3 also compared confrontation of anti-lesbian and antigay bigotry and found that people are generally more positive toward antigay prejudice confronters. Studies 4-5 tested different interventions aimed at reducing barriers to help heterosexual individuals confront antigay prejudice. Study 4 showed that simply allowing males to disclose and affirm their orientation may not be enough to help them confront more, whereas Study 5 showed that giving information about confrontation may reduce beliefs that confronting is ineffective. Together, these studies not only shed light on alliesâ antigay prejudice confrontation outcomes, but also offer valuable information as to how it may be possible to reduce costs to confronters in hopes of encouraging them to confront more often.
Ground State Properties of Strongly Correlated Electron Systems in High Magnetic Field
Keywords: High Magnetic Field
High Tc Superconductor
Magnetism
Quantum Criticality
Quantum Oscillations

Ground states of strongly-correlated electron systems can be affected profoundly if subjected to high magnetic field. In this thesis, we use torque magnetometry as well as modulation field de Haas-van Alphen measurement to measure the magnetic response of three different systems involving of quantum criticality and phase transitions. We employed torque magnetometry in magnetic fields up to 33 T in dc magnets and 65 T in pulsed magnets to the undedoped high Tc cuprate YBCO at 4 K. We observed diamagnetism in two differently doped crystals up to the highest fields applied. While this diamagnetism may still arise from weak bulk superconductivity, it can also be caused by superconducting fluctuations or a reduction of normal state paramagnetism. We also observed that the differential susceptibility dM/dB is rapidly suppressed for B > 16 T, but saturates at a small positive value at higher field. dM/dB departs from linear behaviour with increasing applied field at a characteristic field Hd, and temperature dependence as well as the magnitude of Hd matches the proposed critical field Hc2 = 24 T from previous transport measurements (Grissonnanche et al., Nat. Comm., 4. 3280 (2014)). Using the modulation field method, we measured quantum oscillations of the newly discovered antiferromagnet URhIn5 . We find that the Fermi surface (FS) consists of four sheets, two nearly spherical sheets and two larger orbits that may originate on one cylindrical FS. Multiple copies of these surfaces are needed to match the experimental value of the specific heat coefficient Îł. Advanced band structure calculations are needed to establish the exact FS topology. We also applied the modulation field method to measure the susceptibility of Sr3Ru2O7 at the quantum critical point of the high field anisotropic phase. We observed that the amplitude of the susceptibility peak at the QCP follows a power law with temperature, and determined the critical exponent to be between 2/3 and 1. We could only resolve one dHvA frequency inside the phase at 1 kT, which exhibited neither mass enhancement nor frequency field dependence. Further studies on better crystals would be needed.
Talk to Me: An Educator's Search for Conversations on Ethics in Education
Keywords: ethics
teacher education
teacher identity
teacher misconduct

The purpose of this Delphi study is to explore the role of ethics and ethical decision-making in education in the Ontario context. There is legislation in Ontario that references ethics in relationship to teacher conduct and teacher training, however, there is little evidence that educators actually engage in conversations on ethics or ethical decision-making. Critical theory and the Multiple Ethical Paradigm frame this study and inform the discourse to explore, deconstruct, and analyze the data. The data gathered in this study reveal a complexity with multiple issues that prevent natural conversations on ethics from occurring in educational settings. Given the important role ethics and ethical decision-making play in keeping students safe, welcomed, and respected, and coupled with the current climate of accountability and transparency, educators need to pay greater attention to what this silence on ethics is telling us.
Comprehensive Simulation of One-Dimensional Unsteady Pipe Network Hydraulics: Improved Formulations and Adaptive Hybrid Modeling
Keywords: Hydraulic Modeling
Pipe Networks
Rigid Water Column
Transient Flow
Water Hammer

From municipal water supply to wastewater collection, pressurized pipe networks form the basis of many urban water systems. Numerical models are essential for analyzing their unsteady hydraulics, but there are multiple types of models with poorly understood ranges of applicability. Water hammer models feature greater physical accuracy, making them suitable for highly dynamic conditions. They are, however, more computationally demanding than the simpler yet less accurate rigid water column (RWC) and quasi-steady models. Unsteady hydraulic analyses require solution methods that are both physically accurate and computationally efficient; accordingly, there is an accuracy-efficiency trade-off. To balance these competing demands, this thesis presents an adaptive hybrid transient model (AHTM) capable of simulating the full range one-dimensional unsteady pipe network hydraulics. In developing the comprehensive AHTM, a number of gaps in the literature are addressed. A novel RWC formulation is first proposed, one that overcomes the numerical challenges of previous published work. This is subsequently combined with unsteady flow characterization indices and an adaptive scheme to form an incompressible flow AHTM. Essentially, a more demanding yet more physically accurate model is used only when necessary for efficiency; though powerful, the framework does not consider unsteady-compressible flow. The third objective concerns models for such conditions. A flexible water hammer formulation is introduced that generalizes the method of characteristics and the wave characteristics method, two predominant numerical approaches. Finally, the culmination of this thesis combines each of the aforementioned into a single comprehensive, flexible, and efficient AHTM. The AHTM is shown to adapt to the degree of unsteadiness and, more importantly, individual analyses. Results of this work ultimately benefit practical analyses of unsteady pipe network hydraulics. Not only can simulations be performed more efficiently, but they may encompass multiple transient flow regimes. Moreover, the key advantages of the comprehensive AHTM are its generality and adaptability.
Factors Contributing to Variation in the Management of Radiation Therapy-Induced Nausea and Vomiting
Keywords: cohort study
nausea
radiation therapy
survey
systematic review
vomiting

Purpose: Variation in the management of radiation therapy-induced nausea and vomiting (RINV) negatively impacts patients, practitioners and health systems and likely reflects limits in knowledge and failures to apply evidence. Factors that contribute to this variation are understudied. We investigated five factors that we believe contribute to variation in practice. Methods: 1) A web-based case-based international patterns of practice survey investigated RINV management strategies among radiation oncologists; 2) a systematic literature review investigated the timing and duration of prophylactic serotonin3 receptor antagonist (5-HT3RA) antiemetic therapy in randomized and non-randomized RINV trials; 3) another systematic review investigated the methodologies, endpoints and outcome measures of randomized RINV trials; 4) a prospective cohort study investigated RINV among patients receiving moderate- and low-risk palliative radiation therapy (RT) for bone metastases; and 5) another prospective cohort study investigated RINV among patients receiving long-course neoadjuvant pelvic RT and concurrent 5-fluorouracil-based chemotherapy for rectal adenocarcinoma. Results: Practice patterns varied among 1022 respondents from 12 countries, especially for moderate-risk and low-risk cases. The timing and duration of 5-HT3RA prophylaxis schedules and symptom control rates differed within 25 RINV trials. A diverse collection of methodologies, endpoints and outcome measures were observed in 34 RINV trials. RINV control rates were low within the bone metastases cohort (n=59 [32 evaluable]) with only 31% of patients being free of nausea and 44% being free of vomiting. Vomiting occurred in 21% of patients within the rectal cohort (n=34[33 evaluable]), however, the cumulative incidence of days with vomiting for all patients was only 1.6% of 1407 evaluable days. Conclusions: Our five complementary studies provide insight into factors likely contributing to variation in RINV management. These include a lack of knowledge about practice patterns in RINV management, an uncertainty regarding the ideal prophylactic administration of 5-HT3RAs, the heterogeneity of RINV clinical trial designs and outcome measures, and an incomplete understanding of the incidence of RINV among patients undergoing moderate-risk and low-risk palliative RT for bone metastases and long-course neoadjuvant pelvic RT for rectal adenocarcinoma.
Chronology, Paleoecology and Stratigraphy of Late Pleistocene Sediments from the Hudson Bay Lowlands, Canada
Keywords: Hudson Bay Lowlands
Laurentide Ice Sheet
Marine Isotope Stage 3
Pollen
Quaternary

Stratigraphic records in the Hudson Bay Lowlands (HBL), Canada, offer rare insight into local paleoenvironments and the Late Pleistocene climate system over North America. Age determinations on sub-till non-glacial materials suggest that the HBL, lying near the centre of the Last Glacial Maximum (LGM) extent of the Laurentide Ice Sheet (LIS), was ice-free for parts of Marine Isotope Stage 3 (MIS 3; 57,000 to 29,000 yr BP), MIS 5 (130,000 to 71,000 yr BP) and MIS 7 (243,000 to 190,000 yr BP). The MIS 3 age assignment is notable since it suggests the possibility of significant retreat of the LIS and a relatively high global sea level, both of which are a contrast to assumptions that North America was moderately glaciated, and that global sea level was relatively low during that time interval. Paleoecological proxies, including pollen and plant macrofossils, suggest that the HBL contained peatland and boreal vegetation during all previous non-glacial intervals, and pollen-based quantitative reconstructions of sites which are hypothesized to be MIS 3 and MIS 5a (~80,000 yr BP) in age suggest that climate during MIS 3 may have had less annual precipitation than during MIS 5a and present day. Stratigraphic analyses of these glacial and non-glacial sediments provide insight into the dynamicity of Late Pleistocene ice sheets; multiproxy analyses of three stratigraphic successions along the Albany River resulted in the recognition of at least three glacial advances from shifting ice centers within the QuĂŠbec sector of the Laurentide Ice Sheet during the Late Pleistocene. This dissertation contributes a chronological dataset for reconstructing the movement, timing and dynamics of Late Pleistocene ice sheets over North America, as well as paleoecological data for understanding the character and distribution of boreal peatlands during previous interstadial and interglacial periods.
Regulation and Repair of Neural Stem Cells and the Neurogenic Niche
Keywords: Adult Neurogenesis
Metformin
Neural Stem Cells
p53
Senescence

In the adult mammalian brain, numerous complex regulatory networks exist in order to regulate adult neural precursor cell (NPC) maintenance throughout life. While many of these networks have been described, others remain less well understood. Here, we have asked about three of these pathways (specifically the p53 family, cellular senescence, and AMPK), using genetic and pharmacological tools to determine their roles in precursor maintenance and neurogenesis in vivo. First, we show that p53, p63, and p73 functionally interact in NPCs to regulate cell fate. When these interactions are perturbed due to combined p63;p73 heterozygosity, precursor pools and neurogenesis are rapidly depleted due to an increase in p53-mediated senescence. Second, we demonstrate that senescent NPCs rapidly accumulate in the subgranular zone (SGZ) with age, and this coincides with a decrease in neurogenesis and precursor numbers. When senescent cells in the SGZ are reduced either pharmacologically or genetically, neurogenesis and stem cell proliferation are dramatically enhanced, demonstrating a cell non-autonomous regulatory network between senescent and non-senescent precursors in the hippocampus. Last, we show that AMPK agonist metformin acts on two distinct pathways to regulate cell fate in adult neural precursors. Specifically, we demonstrate that metformin acts to enhance NPC proliferation and self-renewal via a TAp73-dependent mechanism. However, metformin can also promote NPC differentiation by activating an aPKC-CBP pathway, indicating that AMPK plays an important role in regulating cell fate decisions. Taken together, the results of this thesis demonstrate that complex regulatory networks including the p53 family, cellular senescence and AMPK act to maintain adult NPCs, and manipulation of these networks can drastically alter neurogenesis and precursor pools in vivo.