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Climate change is expected to affect Canada through extreme heat events (EHEs). Already vulnerable populations, including newcomers and immigrants, will especially be vulnerable to the health impacts associated with EHEs. This population is important to consider for a country as diverse as Canada. With a focus on Hamilton Ontario, this thesis will assess barriers that immigrants and newcomers face with coping to EHEs. Adverse impacts they face will also be discussed. Current formal and informal coping methods will also be highlighted. Quantitative analysis will also be used to explore the relationship between EHEs, air quality (as measured by the Air Quality Health Index (AQHI)), forward sortation areas and hospital admission for heat-related illnesses. The results of this study highlight that unique factors influencing heat health vulnerability among immigrants and newcomers in Hamilton. The benefits of current formal and informal coping mechanisms will also be discussed, as well as areas for improvement. Quantitative analysis also highlights that the AQHI, maximum temperature and a heat event can impact if an individual is admitted to the hospital for a heat-related illness. However, age, gender and most FSAs were not statistically significant. This thesis highlights the importance of considering the immigrant and newcomer population for EHE and general climate change adaptation efforts. / Thesis / Master of Arts (MA)

京都大学 / 新制・課程博士 / 博士(工学) / 甲第23499号 / 工博第4911号 / 新制||工||1767(附属図書館) / 京都大学大学院工学研究科都市環境工学専攻 / (主査)教授 米田 稔, 教授 清水 芳久, 准教授 島田 洋子 / 学位規則第4条第1項該当 / Doctor of Philosophy (Engineering) / Kyoto University / DGAM

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We study the structure of the set of extreme points of the compact convex set of matrix-valued holomorphic functions with positive real part on a finitely-connected planar domain 𝐑 normalized to have value equal to the identity matrix at some prescribed point t₀ ∈ 𝐑. This leads to an integral representation for such functions more general than what would be expected from the result for the scalar-valued case. After Cayley transformation, this leads to a integral Agler decomposition for the matrix Schur class over 𝐑 (holomorphic contractive matrix-valued functions over 𝐑). Application of a general theory of abstract Schur-class generated by a collection of test functions leads to a transfer-function realization for the matrix Schur-class over 𝐑, extending results known up to now only for the scalar case. We also explain how these results provide a new perspective for the dilation theory for Hilbert space operators having 𝐑 as a spectral set. / Ph. D.

Sediment pulses are defined as large amounts of loose sediment that are suddenly deposited in river corridors due to the action of external factors or processes of natural or anthropogenic origin. Such factors and processes include landslides, debris flows from tributaries, volcanic eruptions, dam removal projects, and mining-related activities. Their occurrence is associated with a surplus in sediment load to downstream reaches, and therefore, with severe channel aggradation and degradation, significant floodplain deposition, increase in flood frequency, damage of infrastructure, and impairment of aquatic habitats. The main objective of this research is to develop a better understanding of the fundamental mechanisms that govern the propagation of these sediment-flow hazards in alluvial sand-bed rivers. Specifically, the study presented herein is divided into three separate parts to achieve this overarching goal. First, a component intended to improve the numerical modeling of morphodynamic processes in alluvial sand-bed rivers by proposing a novel solution methodology that applies either the decoupled or the coupled modeling approach based on local flow and sediment transport conditions. Secondly, a detailed numerical analysis to characterize the behavior of fine-grained sediment pulses (i.e. composed of granular material in the sand size range) in alluvial sand-bed rives by identifying the properties of these types of pulses, as well as the characteristics of riverine environments, that are most relevant to their downstream migration. And lastly, a case study application to assess the effect of the magnitude, duration, and frequency of severe hydrologic events on the overall propagation behavior of fine-grained sediment pulses in alluvial sand-bed rivers. Ultimately, this research aims to contribute towards reducing the uncertainty associated with the impact of these phenomena, and hence, improving the resilience of rivers corridors. / Ph. D.

The decline of easily accessible reserves pushes the oil and gas industry to explore deeper wells, where the ambient temperature often exceeds 210 °C. The need for high temperature operation, combined with the need for real-time data logging has created a growing demand for robust, high temperature RF electronics. This thesis presents the design of an intermediate frequency (IF) variable gain amplifier (VGA) for downhole communications, which can operate up to an ambient temperature of 230 °C. The proposed VGA is designed using 0.25 μm GaN on SiC high electron mobility transistor (HEMT) technology. Measured results at 230 °C show that the VGA has a peak gain of 27dB at center frequency of 97.5 MHz, and a gain control range of 29.4 dB. At maximum gain, the input P1dB is -11.57 dBm at 230 °C (-3.63 dBm at 25 °C). Input return loss is below 19 dB, and output return loss is below 12 dB across the entire gain control range from 25 °C to 230 °C. The variation with temperature (25 °C to 230 °C) is 1 dB for maximum gain, and 4.7 dB for gain control range. The total power dissipation is 176 mW for maximum gain at 230 °C. / Master of Science

Decreasing reserves of natural resources drives the oil and gas industry to drill deeper and deeper to reach unexploited wells. Coupled with the demand for substantial real-time data transmission, the need for high speed electronics able to operating in harsher ambient environment is quickly on the rise. This paper presents a high temperature VCO for downhole communication system. The proposed VCO is designed and prototyped using 0.25 μm GaN on SiC RF transistor which has extremely high junction temperature capability. Measurements show that the proposed VCO can operate reliably under ambient temperature from 25 °C up to 230 °C and is tunable from 328 MHz to 353 Mhz. The measured output power is 18 dBm with ±1 dB variations over entire covered temperature and frequency range. Measured phase noise at 230 °C is from -121 dBc/Hz to -109 dBc/Hz at 100 KHz offset. / Master of Science

As the oil and gas industry continues to explore higher temperature environments, electronics that operate at those temperatures without additional cooling become critical. Additionally, current communications systems cannot support the higher data-rates being offered by advancements in sensor technology. An RF modem would be capable of supplying the necessary bandwidth to support the higher data-rate. A voltage-controlled oscillator is an essential part of an RF modem. This thesis presents a 2.336-2.402 GHz voltage-controlled oscillator constructed with 0.25 μm GaN-on-SiC technology high electron mobility transistor (HEMTs). The measured operating temperature range was from 25°C to 225°C. A minimum tuning range of 66 MHz, less than 20% variation in output power, and harmonics more than 20 dB down from the fundamental is observed. The phase noise is between -88 and -101 dBc/Hz at 100 kHz offset at 225°C. This is the highest frequency oscillator that operates simultaneously at high temperatures reported in literature. / Master of Science / The oil and gas industry require communications systems to transmit data collected from sensors in deep wells to the surface. However, the temperatures of these wells can be more than 210 °C. Traditional Silicon based circuits are unable to operate at these temperatures for a prolonged period. Advancements in wide bandgap (WBG) semiconductor devices enable entrance into this realm of high temperature electronics. One such WBG technology is Gallium Nitride (GaN) which offers simultaneous high temperature and high frequency performance. These properties make GaN an ideal technology for a high temperature RF modem. A voltage-controlled oscillator is an essential part of a RF modem. This thesis demonstrates a GaN-based 2.36 GHz voltage-controlled oscillator (VCO) whose performance has been measured over a temperature range of 25°C-225°C. This is the highest frequency oscillator that operates simultaneously at high temperatures reported in literature.

Wearable computers allow users the freedom to work in any environment including hazardous environments that may require protective clothing. Past research has shown that protective clothing interferes with manual materials handling tasks, medical tasks, and manual dexterity tasks. However, little information exists regarding how protective clothing affects task performance with wearable input devices. As a result, a study was conducted to address this issue and offer recommendations to enhance the compatibility of chemical protective clothing and wearable input devices. Sixteen active-duty soldiers performed a text-entry task with a wearable mouse and touch pad, while bare handed, wearing 7-mil, 14-mil, and 25-mil chemical protective gloves, wearing a respirator alone, and wearing the respirator and each of three gloves. Upon completion of the experiment, participants rated task difficulty, confidence using the input device, and input device preference. Task completion times were 9% slower with the 25-mil glove than the 7-mil glove. Text entry was not perceived as difficult when bare handed, or wearing the 7-mil and 14-mil gloves, suggesting that thin chemical protective gloves (i.e. 7-mil and 14-mil) are more suitable than thicker gloves for use with wearable input devices. When using the touch pad, task completion times were 17% faster than when using the mouse. Subjective ratings of difficulty, confidence, and preference provide strong support for the use of a touch pad input device rather than a mouse. / Master of Science