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Ice is a prominent characteristic of water bodies in cold regions. For rivers regulated for hydropower operations, the production of ice particles can result in obstructions and subsequent performance issues during energy production. Rough and thickened ice covers resulting from high flow conditions can also lead to substantial hydraulic losses. While ice formations impact hydropower operations, a river’s flow hydrograph also influences ice processes from freeze-up through break-up. Research investigations into the influence of regulation on ice processes benefits not only hydropower practioners, but also those who are impacted by hydropower operations. Further, understanding these cause-and-affect relationships supports design of innovative tools to quantify the impact of ice on river hydraulics. In this study, a detailed characterization of ice processes is presented for the regulated Upper Nelson River region located at the outlet of Lake Winnipeg in Northern Manitoba, Canada. With a focus on freeze-up and mid-winter processes, this characterization informed design of a 2D numerical modelling methodology to simulate ice-affected winter hydraulics. Model development included simulation of both thermal and dynamic ice phenomenon, which relied on derivation of numerous site-specific hydraulic functions. The presence of significant skim ice runs in this region inspired development of a novel treatment to simulate freeze-up jamming of skim ice floes on very mild-sloped rivers. The modelling methodology shows strong performance in simulating both freeze-up and mid-winter hydraulics, which is a signficiant contribution considering the complexity of this lake-outlet system. A quantitative evaluation of the effects of climate change on river ice hydraulics is included, with future projection of shorter and warmer winters leading to greater cumulative discharge from Lake Winnipeg. While discharge increases may lead to increased power production in future years, concurrent projections of increased inter-annual variability may present new operational challenges. Findings from this original research can be applied not only to the Nelson River, but also other regulated regions that are impacted by river ice.

Rapidly changing environments impact avian populations greatly. Indeed, variable weather affects the timing of crucial resource availability and behaviours of breeding birds. Migratory birds are particularly threatened by advancing springs and must adjust their migration timing to remain synchronized with spring phenology. Environmental factors such as weather variability are known to influence bird timing both during breeding and migratory periods but have rarely been investigated for their impact across migration routes. Once birds are at their breeding locations, how environmental factors influence local timing and movements has also been little examined. In this study, in a declining long-distance migrant, the purple martin (Progne subis), I first investigate how extrinsic (environmental), and intrinsic (morphological, migration destination) factors impact migration timing and rate. Second, I investigate the timing of parental roosting during active parental care, and how environmental and nest conditions influence this behaviour. I found that variation in destination and timing are the main influence on spring arrival date and migration rate, while to a lesser extent favourable weather promotes faster migration. The great influence of spring departure on migration rate and arrival suggests selective pressure on migration timing across routes to match with conditions at the breeding grounds. I also found that summer roosting is prominent in purple martins with colder evenings and increased parental investment increasing the odds of parents remaining at their colony at night. Overall, my findings indicate that the influence of environmental factors on movement behaviour may vary by season, with spring migration being mostly driven by intrinsic factors, while summer roosting may be most influenced by local temperature. Future research on the effects of environmental factors on migratory stopover duration and the seasonality of roosting would further our understanding of these timing behaviours and how they may interact with advancing climate change.

A planet once flourishing with ecological biodiversity is now experiencing catastrophic changes as it undergoes a severe exploitation of its natural resources. Such a level of exploitation is predominantly caused by various but linked human-centric or anthropocentric forces. Everything we do as humans has an effect on the planet, and many human activities have grave and at times, unforeseeable effects. At present, we overexploit the Earth’s resources constantly – with the flick of a switch we utilize fossil fuels that power electricity; with a trip in the car we emit greenhouse gases; with a purchase at the grocery store we use excessive packaging – and the extent to which the Earth’s resources are being used to meet the demand of a large and growing human population has created severe exploitation. This feeding frenzy has led to the current prognosis: an astronomical number of environmental disasters and projected global temperatures that cannot sustain plant, animal, or human life in the future. The widespread consequences of human activities such as major wildlife extinction, rising sea levels, air pollution, and irreversible global warming look to perpetuate until the Earth is uninhabitable. As one population among many at extreme risk of major die-off, it is crucial that we explore what remedial options we have left. These ecologically catastrophic changes are only characteristic of our relatively recent history as humanity’s recent answers to fundamental survival questions have trended towards overlooking environmental sustainability. I have come to understand agriculture, from its ancient form to the current industrial and mass-scale variety, as one game-changing initiation if not the origin of massive human exploitation of the Earth’s resources. Thus, both industrial and ancient agriculture will be the focus of my research. Through the exploration of recent historical and scientific research surrounding agriculture, I will provide insight into how we made our way to the current crisis, what prevents us from changing our unsustainable behaviour, and how we can look within ourselves and at the external complex system in which we live, to change the current prognosis and come home to a sustainable way of life on this planet.

With the increasing concern of climate change and greenhouse gas emissions, innovative solutions to produce energy via renewable sources are needed. Geothermal energy has the potential to provide heating and cooling to residential and commercial buildings, however, its implementation has been stunted due to high initial costs, longer payback periods, and lesser return on investment. Helical steel piles, mainly used as structural foundations for buildings, have the potential to act as in-ground heat exchangers, producing higher efficiencies than conventional borehole systems at a lower cost. Eight helical steel piles, fitted with plastic tubing for fluid circulation, have been installed in an experimental site in Waterloo, Ontario. Cooling and heating tests have been conducted on the novel system to evaluate the capacity, power consumption and coefficient of performance. This paper presents the results of the peak and steady state capacity tests as well as the limitations experienced. Part of Proceedings of the Canadian Society for Mechanical Engineering International Congress 2022.

This study focuses on simultaneous vibration suppression and energy harvesting in a broad frequency band. For this purpose, a variant nonlinear energy sink (NES) is developed. The developed variant NES consists of a nonlinear oscillator and an electromagnetic energy harvester. Unlike a true NES, the nonlinear oscillator’s spring is not essentially nonlinear. The variant NES is attached to a single-degree-of- freedom (SDOF) primary system that is subjected to a base excitation. Different from the traditional way, the electromagnetic energy harvester is placed between the oscillator’s mass and the base. This study investigates the performance of this non-traditional variant NES under harmonic base excitation. First, the developed apparatus is described. Subsequently, the approximate solutions of steady state responses are derived using the harmonic balance (HB) method. Next, computer simulations are conducted using both the HB method’s solution and numerical integration. The results show that under harmonic excitation, the proposed apparatus behaves similarly to a true NES with the following features: amplitude jump, excitation level dependence, strongly modulated response (SMR), etc. Overall, the non-traditional variant NES can achieve vibration suppression and energy harvesting in a broad frequency band. Part of Proceedings of the Canadian Society for Mechanical Engineering International Congress 2022.

Beluga whales (Delphinapterus leucas) are an Arctic cetacean with circumpolar distribution. They are known to have distinct, lengthy and consistent migration paths to and from summer and wintering grounds. The Western Hudson Bay beluga population, the largest summering aggregation in the world, inhabits three main estuaries in the summer season. Little protection is afforded to them here, and little is known of the specific details of their summer distribution and factors affecting that distribution. Using a combination of satellite telemetry, aerial photos, satellite data, and visual observations and historical reports, investigations into factors affecting beluga distribution in Western Hudson Bay were conducted. An examination into beluga age class distribution near the Churchill and Seal River estuaries, using aerial survey imagery, suggested that belugas may not be segregating by age in summer, however the Seal River estuary may be more important from a calf-rearing perspective. Belugas use a greater home range than we would expect, based on historical range data, in the face of predation by their main predator, the killer whale (Orcinus orca). Killer whales are sighted more frequently in Hudson Bay than historically, and results presented here show that ice entrapments, occurring with higher frequency in the future, may impact distribution of beluga as killer whales expand their range and occurrence in Hudson Bay. Finally, an assessment of beluga behaviour in the presence of whale-watching vessels showed that beluga response to vessels varied but the probability of travelling behaviour was significantly greater with distance from vessels; belugas also appear to be spending more time interacting with vessels now, as compared to 15 years ago when there were fewer whale-watching vessels. The results found through this research are useful in informing climate change implications, marine-protected area boundaries, policy and marine spatial planning, and subsistence harvest management.

The demand for electrical energy has increased since the population of and automation in factories have grown. The manufacturing industry has been growing dramatically due to the fast-changing market, so electrical energy for manufacturing processes has increased. As a result, solar energy has been installed to supply electrical energy. Thus, assessing a solar panel company could be a complex task for manufacturing companies that need to assess, install, and operate solar panels when several criteria with different hierarchies from decision-makers are involved. In addition, the stages of a solar panel system could be divided into analysis, installation, operation, and disposal, and all of them must be considered. Thus, the solar panel company must provide a holistic solution for each stage of the solar panel lifespan. This paper provides a fuzzy decision-making approach (Fuzzy TOPSIS) to deal with the assessment of solar companies using the S4 framework in which the sensing, smart, sustainable, and social features are labeled with linguistic values that allow the evaluation of companies using fuzzy values and linguistic labels, instead of using crisp values that are difficult to define when decision-makers are evaluating a solar company for installation of the solar panels. The S4 features are considered the benefits of the evaluation. In the case study presented, three solar panel companies with different alternatives are evaluated on the basis of three decision-makers from manufacturing companies using the S4 framework. This paper considers the benefits of solar companies in the context of decision-makers participating in a multi-decision selection of such a company to install solar panels, so that the selection process is more effective. Thus, the proposed Fuzzy TOPSIS method proved efficient when selecting a solar panel company from among many options that best meets the needs of manufacturing companies.

The Himalayas are among the most threatened regions of the world to climate change. Women in the Himalayas are particularly vulnerable to environmental changes due to their various farm work responsibilities. This scoping literature review draws on anthropological and climate-based research to explore how the effects of climate change in Ladakh (situated in the Indian Himalayas) pose challenges for women farmers. Through utilizing a feminist political ecology theoretical framework, this paper reflects on the interlinking impacts of gendered power relations and environmental issues that encompass the everyday lives of Ladakhi women. This is unpacked in order to illuminate the non-homogeneity of the lived experiences of climate change that diverge along gendered, class, caste, and socioeconomic lines. Ontario Graduate Scholarship (OGS)

Metal-free heteroatom-doped carbonaceous materials such as carbon nitride (CN) with secondary/tertiary nitrogen-rich catalytic centers as well as chemical and thermal resilience can potentially serve as catalysts for many organic reactions. However, because of the stable alternate Csp2–Nsp2 configuration of N-linked heptazine units (C6N7), the chemical modification of CN via doping and functionalization has been a critical challenge. Herein, we report an exceptional 9.2% sulfur content in CN with sulfonate/sulfate functional groups (CNS) via a one-step in situ synthesis approach. When used as a catalyst for the dehydration/hydration of glucose, CNS catalysts demonstrate a relatively high yield and selectivity toward levulinic acid, LLA, (≈48% yield with 57% selectivity) production. CNS’s high activity of direct conversion of glucose to LLA can be attributed to the synergistic catalytic effects of multiple sulfur functionalities, better dispersibility, and microstructural porosity. The synthesized CNS catalysts offer an energy efficient direct LLA production route to bypass the multistep process of sugar to LLA conversion.

The arctic sea ice is presenting unprecedent retreat and some research state that the arctic region is warming three to four times faster than the rest of the world. At the same time, middle latitudes have experienced extreme events such as extreme snow fall and episodes of extreme low temperatures which some literature suggest that are connected to the arctic warming. In this thesis we explore teleconnections between the arctic and the tropics, most specifically northern South America (nSA). For this analysis we have two objectives: exploring how the arctic sea ice decline could influence the precipitation over nSA, and second, using two PAMIP models scenarios to explore future impacts of the arctic sea ice loss over the precipitation in nSA. Firstly, using sea ice data provided by NSIDC and precipitation monthly means reanalysis data for the same period provided by NCEP/NCAR, we correlate precipitation anomalies in equatorial South America with Arctic sea ice extent anomaly series. A precipitation center with the highest correlation with Arctic sea ice extent anomalies was identified in the eastern part of equatorial South America (in the Amazon rainforest). This region's time series was then compared to the sea ice extent anomaly using a linear regression dependence analysis. An rsquare of 15% was found; in other words, the sea ice variability might influence 15 percent of the precipitation volume anomaly in some parts of Brazil’s northern and northeastern regions. Secondly, we used five models from the PAMIP to quantify the precipitation changes over nSA using two different scenarios, one employing present-day SST and sea ice concentration (SIC) and other consisting in projections of the SIC in the Arctic considering 2°C atmospheric warming relative to pre-industrial conditions. The model average projections for the DJF season show drier conditions in the northern part of the Amazon and wetter conditions in the southern part in the >2 °C scenario. At the same time, the JJA season shows wetter conditions in the western part of the Amazon region, and drier conditions in the eastern part. These precipitation changes are related to changes in the atmospheric circulation in the tropical Atlantic.