VictorJuiz/thesis huggingface dataset:
Practical Considerations of Discrete Multitone Modulation for High-Speed Wireline Links
Keywords: communication circuits
digital modulation
discrete multitone
DMT
OFDM
wireline

To overcome the severe losses beyond 28 GHz in low-cost electrical channels, 4-level pulse-amplitude modulation (4-PAM) wireline links targeting 112 Gb/s incorporate resource- or power-intensive equalization schemes such as decision-feedback equalizers (DFEs) with many taps. Alleviating the timing constraints that cause DFEs to balloon in size and power, discrete multitone (DMT) modulation involves independent sub-channels that can be equalized in the frequency domain without feedback. DMT allows flexibility in assigning bits to each sub-channel, thereby potentially avoiding lossy parts of available frequency spectrum. This document presents behavioural modeling and experimental results on DMT transceivers. One set of simulations aimed to study various impairments shows 200-Gb/s operation at a bit error rate (BER) of less than 10^{−5} over an IEEE P802.3ck channel with 21 dB of loss at 50 GHz and assuming 150 fs_{rms} of jitter, 1.26 mV_{rms} of noise at the receiver’s input, and 7-bit 80-GS/s data converters. The estimated power and area of the associated digital signal processing are comparable to those of DFE. We also present experimental results achieving 61.6 Gb/s at a BER of 8.6×10^{−4} over a physical channel with severe magnitude response notches that is very challenging for 4-PAM. Furthermore, because there is considerable variability in the use of bit loading and power loading in DMT for wireline applications, this document also elucidates the relative benefits of these loading mechanisms. After comparing various loading scenarios in simulations, we propose a method for dynamically adjusting bit and power profiles based on the bit error distribution across sub-channels. A second set of experimental results demonstrates 75-Gb/s DMT operation with a spectral efficiency of 2.5 b/sample over a channel with a smooth magnitude response exhibiting a loss of 26 dB at half the sampling rate and 33 dB at 1/4 the data rate (the Nyquist rate of a 4-PAM signal at the same data rate). The proposed dynamic bit and power allocation method helped get a BER of 2×10^{−5}, lower than the BERs reported by other recent DMT implementations for high-speed wireline links, including some with lower channel losses than that compensated in our setup.
The Impact of Ammonia Combustion on Soot Emissions Formation in Compression Ignition Engines
Keywords: Ammonia
Diesel
Emissions
Engine
Nanostructure
Soot

The impact of ammonia (NH3) co-firing with diesel on the greenhouse gases (GHG) and soot emissions of compression ignition (CI) engines is a current concern in large-scale agriculture, marine transportation, and shipping applications for which NH3 is proposed as a near-term decarbonization solution. In this thesis, the addition of NH3 to hydrocarbons combustion is studied in laminar diffusion co-flow C2H4 flames and through port injection in a dual fuel diesel engine. The effect of NH3 combustion on soot formation is investigated numerically and experimentally using measurements of: (1) the soot volume fraction and mass yield, (2) the average primary particles diameter and number concentration, (3) the graphitization of the soot nanostructure, and (4) the soot surface nitrogen content. Engine GHG, NOx, and unburnt NH3 emissions are also measured. The results show a suppressive chemical effect for NH3 cofiring with hydrocarbons on soot inception and growth in flame and engine combustion. The chemical bonding of nitrogen to the soot surface is found to increase soot graphitization leading to less carbon bonding. In addition, the nitrogen content of the soot surface is found to increase indicating an increased potential for nitrogenated PAHs formation with NH3 addition.
Application of Microwave Imaging in Identifying Valuable Minerals/Metals in Ore Sorting
Keywords: electromagnetic scattering
microwave imaging
ore sorting

Ore sorting is a pre-concentration technique used in mineral processing to reject low-grade ore particles from the feed material at coarse particle sizes. Modern ore sorting technology employs sensors to distinguish between the properties of different rocks. This study aims to investigate if microwave imaging (MWI) can be used to distinguish rocks that contain valuable minerals or metals from those that do not, for potential application in sensor-based ore sorting as a new sensing method. Compared to more established sensors, such as XRT and XRF, MWI has the potential to penetrate deeper into ore particles and to be used as a supplementary method for analyzing those ores with high contrast in electromagnetic (EM) properties between valuable minerals/metals and gangue minerals. Microwave scattering simulations and experimental measurements are performed on both gold ore cores and gold ore particles with irregular shapes. A MWI algorithm and a sorting algorithm are proposed to form images of rocks and to make the accept/reject sorting decision, respectively. Both simulation and measurement results suggest the feasibility of using MWI to identify the presence of valuable minerals or metals in ores.
Serbian Queer Identities in Diaspora in Canada and the United States: Challenging Theories of “Balkan Ethnonationalism”
Keywords: Balkan ethnonationalism
Identity formation
Integration/Acculturation
Intersectionality
Serbian Diaspora
Serbian queer identities

Western social scientists and political observers have depicted Serbia, and former socialist countries in the so-called Balkan region covering Southeastern and Southwestern Europe, as embodiments of violent ethnic nationalisms (Dyrstad, 2012; Gordy, 2016). This study investigates the existence of ethnonationalism among members of the queer Serbian diaspora in Canada and the United States, using cultural and social theories of intersectionality, fluidity, and ever shifting identifications, as well as 15 personal interviews with queer Serbs who immigrated to Canada and to the United States between the 1990s and 2000s. In so doing, this study highlights the complexity and liquidity of Serbian queer identifications and the active ways in which these identity formations reflect forms of social privilege, yet also sexual, economic, and cultural marginality. Serbian queer immigrant notions of self, Other, “nation,” and “homeland” present negotiations of this privilege and marginality amid hegemonic and deeply homophobic Canadian and American societies; spaces already hostile to migrants who defy the normative cultural foundations of capitalism, heterosexuality, and Western modernity steeped in celebrations of civilization associated with “Europe” wherein Serbia and other Balkan societies imagined as “ethno-nationalistic,” and therefore “violent and backward,” do not really belong. The interviews illuminate the violent ways in which the Serbian state and society also discriminate against queer and non-normative members of the nation, further complicating and layering how queer Serbs in diaspora perceive home, nation, and express or do not express modes of nationalism. The analysis draws from critical realism, realist ontology, and constructivist epistemology to uncover underlying power dynamics and social structures giving shape to these Serbian queer identity formations in diaspora. Ultimately, this research contributes to deeper and better understanding of queer and immigrant identitites in Canada and the United States adding new knowledge especially to literatures on queer nationalisms in North America, as well as theories of nationalism across political science, history, and area studies focused on the geopolitical region called the Balkans.
Development and Research into Visible Light Photocatalysts and the Photocatalytic Mechanism
Keywords: CMP-NMR
NGQD
NMR
Photocatalysis
TiO2

Heterogeneous photocatalysis has long been purported as a renewable and green solution to many environmental issues, but none more promising than organic degradation for applications such as wastewater remediation or drinking water purification. However, despite significant research interest and resources, photocatalysis has largely remained a scientific pursuit, with very limited commercial use cases being reported to date. This lack of real-world utilization can be attributed to both a material problem; where current photocatalytic materials simply aren’t effective enough to compete with traditional techniques, and a testing problem; where lab scale testing generates large amounts of data but lacks any insight into photocatalytic mechanisms. Through a nanosized composite utilizing novel nitrogen doped graphene quantum dots and hydrothermally synthesized titanium dioxide (TiO2-NGQD composite), a new range of highly efficient visible active photocatalysts are presented. To address a knowledge gap in photocatalytic testing, nuclear magnetic resonance (NMR) is introduced and employed to monitor photocatalytic reactions which require no additional sample prep or manipulation. It is shown via NMR experiments that the TiO2-NGQD composites outperform the commercial standard photocatalyst of P25 TiO2 in both full spectrum and visible only conditions and that intermediates could be easily identified and quantified. These experiments were extended via a newly developed technique called comprehensive multiphase NMR (CMP-NMR) which was employed to study a photocatalytic system for the first time. These experiments shed new insight into the photocatalytic mechanism and identified a region of restricted diffusion near the surface of the photocatalyst to be of significant importance. It was in this region, or “gel phase”, where the majority of degradation was identified to occur, and further suggested that it was through reactive oxidative species (ROS) and not direct oxidation that was responsible for the photocatalytic degradation. Lastly, it was shown that CMP-NMR could be utilized to show mechanistic differences between two similar photocatalysts in P25 TiO2 and TiO2-NGQD, providing a new foundation for future photocatalytic works.
Blood-Pool Stress MRI as a Tool for Identifying Early Biomarkers of Diabetic Heart Failure with Preserved Ejection Fraction
Keywords: Diabetes
Heart Failure
hypercapnia
microvasculature
MRI
Vasoreactivity

Microvascular dysfunction (mvD) has been implicated as the primary hallmark of several cardiac and inflammatory diseases (e.g., diabetes, heart failure), affecting millions of people worldwide. The onset and progression of microvascular disease is driven by vascular inflammation and is characterized by vascular smooth muscle cell thickening and impaired vasomodulation, resulting in reduced baseline perfusion and potentially leading to tissue damage. The ability to noninvasively assess microvascular dilation and constriction is essential to assessing intact microvascular function and dysfunction. Yet, conventional measurements based on catheterization and MRI blood oxygenation are invasive and not specific to changes in blood volume, respectively. While cardiac and skeletal muscle mvD have been predicted to be the origin of diabetic heart failure and heart failure with a preserved ejection fraction (HFpEF), current diagnostics are onlyutilized when the patient suffers from cardiac symptoms, at which point the microvascular system is already compromised. This requires a paradigm shift in diagnostics, focusing on the early detection of mvD prior to the onset of heart failure signs and symptoms. In this body of work, we propose that MRI can serve as a non-invasive imaging modality to diagnose mvD within the heart and skeletal muscle, which can offer an early diagnostic platform for diabetics who are at risk of developing HFpEF and other diabetic cardiomyopathies. By combining the use of an MRI blood-pool contrast agent, T1 – weighted imaging, and mild carbon dioxide as a vasodilator, we showcase a technology that can assess microvascular reactivity in bothcardiac and skeletal muscle. Evaluation in a non-genetically modified rat model of type II diabetesiii revealed that cardiac and skeletal muscle reactivity are compromised prior to any classical signs and symptoms of heart failure (e.g., diastolic dysfunction, hypertension, fibrosis). These findings were shortly followed by exercise intolerance and a reduction in oxygen saturation in skeletal muscle. Additionally, we show that sex-dependent differences exist from a young age and must be considered when developing diagnostic criteria for HFpEF. The studies presented in this thesis will pave the way for translating this diagnostic platform into a clinical setting, where patients suffering from type II diabetes and are prone to developing HFpEF can be diagnosed early and begin treatment, prior to exhibiting heart failure symptoms.
Illuminating Protoplanetary Disk sub-Structures and their Indirect Effects on Exoplanets
Keywords: Planet Formation
Protoplanetary Disks
Stellar Irradiation

Of all the areas of astrophysics, the scales involved in forming planets span the most orders of magnitude. One of the biggest outstanding questions in astrophysics is how planet formation proceeds. Everything from sub-micron sized dust grains that are responsible for passively heating a protoplanetary disk, to centimeter sized pebbles which accrete to form planets, or gaps and rings in protoplanetary disks that are tens of AU in diameter, can effect the planets that eventually form. In this thesis, I will describe several contributions to this enormous field which all attempt to understand the substructures in protoplanerary disks and how they affect planet formation. I begin by focusing on a particular variety of exoplanet called super-Earths or sub-Neptunes. I investigate the relationships between planet properties and their host star (as a proxy for the conditions in the protoplanerary disk) and compare the observed trends with those implied or predicted by various theories of planet formation. Then I re-focus onto the protoplanetary disk by performing a linear perturbation of the secular gravitational instability with drifting dust. Previous analytical derivations of growth rates do not include the radial drift of dust, which is a guarantee in protoplanetary disks. I show that not only does the instability persist, but also the radial dust drift excites larger scale perturbations than disks with non-drifting dust. Lastly, I perform 2D hydrodynamic simulations of irradiated protoplanetary disks. My simulations capture the growth of the irradiation instability and the inward propagating thermal waves that are predicted by linear theory. Interestingly, I find that the thermal waves stall and the disk reaches a steady state. Such a steady state produces sub-structure in scattered light and thermal continuum emission on scales that are, unfortunately, below current detection thresholds. Together, these works expand our knowledge and understanding of protoplanetary disk substructures and their implied affects on the resulting planetary systems. They also introduce a novel steady state of protoplanetary disks which has far reaching consequences. Protoplanetary disks set the stage for planet formation and the work presented in this thesis paves the way for further investigation of irradiated protoplanetary disks and the implied imprints left on the exoplanets that eventually form.
Bolted CHS Flange-Plate Connections under Tension, Bending and Combined Loads
Keywords: Bolted connections
Circular flange plates
Design recommendations
Experiments
Hollow structural sections
Prying effect

This thesis presents research on bolted circular hollow section blank flange-plate connections under axial tension, bending and combinations of these loads. For each load situation, the existing experimental and numerical data are collated and reviewed, then expanded by additional large-scale laboratory experiments (totalling 8) and parametric numerical (non-linear finite element) models (totalling 480) by the author. The resulting database is screened to isolate only the pertinent failure modes (or limit states) for the connection, then the eligible data are used to evaluate existing and new proposed design methods based on prying models. For each design method, the difference in using the ultimate stress, instead of the traditional yield stress, for the flange-plate plastification criterion is also analysed. Design procedures are recommended for bolted circular hollow section blank flange-plate connections under axial tension and under bending, and a reliability analysis is performed to generate appropriate resistance factors. For the load case of combined tension and bending studied (for which the first-ever laboratory tests on such connections are performed), a practical linear interaction design method is advocated which gives acceptable statistical results.
Life with the Maladie Alcoolique: Conceptions of Drinking and Abstinence in a French Mutual-Aid Group
Keywords: addiction
anthropology of concepts
anthropology of ethics
France
medical anthropology
mutual-aid

This dissertation explores conceptualisations of alcohol dependence and abstinence in Vie Libre, a French mutual-aid group. Based on two years of ethnographic fieldwork in Paris, France, both with a local group chapter and addictions specialists at a nearby hospital, it describes how group members conceived of their drinking histories, understood themselves to be suffering the “maladie alcoolique,” and buttressed that understanding via their group involvement. It argues that their concept of the maladie was referentially inclusive, its non-specificity bounded by a tautological relationship with abstinence, and could thus accommodate considerable variations of experience, thought and feeling both between and within individual members. It shows how understandings of their maladie were open to contestation and disruption but that their self-descriptions as malades were collectively stabilised by their participation in Vie Libre. Drawing on participant observation with addictology doctors, it is claimed that clinical encounters were not reductive of patient experiences and self-interpretations, as if “formal” diagnostic entities (as of the DSM or ICD) abutted and threatened them, but in fact were predicated on them. Finally, in comparison with the speaking styles described of Alcoholics Anonymous, it is shown that Vie Libre participation encouraged provisionality and experimentation in self-representation and did not entail the adoption of a specific story of drinking or a substantively restrictive identity as a malade. Altogether, this work offers a description of mutual-aid group participation based on conceptual and affective variability and inclusivity, including that provoked by close collaboration with specialists and formalised involvement in medical institutions, and undergirded by discursive norms that encouraged narrative heterogeneity. This ethnography aims to contribute to the anthropological literatures on ethics, concepts and medical narratives, as well as to understandings of addiction, abstinence, and patient support groups.
Probing for N-acetylglucosamine in the Glycans of Escherichia coli
Keywords: Bacterial glycans
Biofilms
GlcNAz
Glycobiology
Metabolic labelling
Polysaccharide

The glycobiology of bacteria is fundamental to understanding many aspects of their behaviour and how they interact with their environments, infect hosts, and transition between various lifestyles. Typical lab culturing conditions ignore the often-dominant biofilm lifestyle of bacteria, but it is in that form that many microorganisms survive in nature and persist under the stressful environment of host cells. The altered glycobiology of the sessile cell results in changing glycan distribution levels as extracellular polymeric substances begin to form the nascent biofilm matrix. The important biofilm polysaccharide poly-β-1,6-N-acetylglucosamine (PNAG) was studied using the PNAG hydrolase DspB, developing a PNAG-specific binding probe for specific detection in the heterogeneous setting of a biofilm. Applying this tool to the early stages of biofilm development revealed how PNAG accumulates in areas of locally high concentrations, explaining the effectiveness of DspB binding despite its lower affinity for PNAG oligosaccharides. PNAG is composed of N-acetylglucosamine (GlcNAc), the most ubiquitous member of the amino sugars, which are disproportionately found in many crucial bacterial glycans. The nucleotide sugar substrate for glycan biosynthesis UDP-GlcNAc is a product of the hexosamine biosynthesis pathway and a key target for metabolic glycan labelling. Engineering the hexosamine pathway through introduction of the hexosamine 1-kinase NahK permitted direct feeding of the metabolic analogue N-azidoacetylglucosamine (GlcNAz) and metabolic labelling in E. coli. The cytosolic production of UDP-GlcNAz was confirmed using fluorescence assisted polyacrylamide gel electrophoresis. In the typical planktonic lifestyle, dissection of the GlcNAc glycome for potential UDP-GlcNAz utilization revealed varying degrees of incorporation in glycan destinations, with the highest levels of incorporation observed in peptidoglycan, and no observable incorporation in the Wzx/Wzy-dependent glycans lipopolysaccharide or enterobacterial common antigen. The lack of undecaprenyl-pyrophosphoryl-GlcNAz intermediates generated in vivo corroborated this result. Finally, returning to the biofilm lifestyle, PNAG was found to incorporate low levels of GlcNAz, determined through isolation of labelled biofilm matrix material and through investigations with PNAG synthase in vitro promiscuity towards UDP-GlcNAz. This body of work will guide future developments of carbohydrate-based probes and metabolic engineering strategies in future studies of bacterial glycobiology.