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THE 2016 CAGS/PROQUEST DISTINGUISHED DISSERTATION AWARD WINNER IN THE CATEGORY OF ENGINEERING, MEDICAL SCIENCE AND NATURAL SCIENCES
Dr. Drew Higgins, University of Waterloo
Nanostructured Oxygen Reduction Catalysts Designs to Reduce the Platinum Dependency of Polymer Electrolyte Fuel Cells
Incidents such as the 2011 pipeline rupture in northern Alberta and the disastrous 2013 derailment of a crude oil containing freight train in Lac-Megantic highlight some of the most serious issues associated with our rapidly increasing fossil fuel dependency. While climate change concerns and natural resource depletion are motivation enough, it is clear that we need to develop clean and safe methods of producing, handling and delivering energy. A sustainable energy economy will undoubtedly rely on renewable sources of fuels for the transportation sector, one of the biggest greenhouse gas emitters. Polymer electrolyte fuel cells (PEFCs) are ideal for this purpose, as they are electrochemical devices that efficiently convert oxygen and renewably generated hydrogen into electricity and water. Their clean emissions and fast refueling times make PEFCs highly amenable for transportation applications; however their commercial viability is still hindered by high capital costs and inadequate long term operational stability. A main contributor towards both of these issues is the platinum-based catalysts needed to convert the oxygen and hydrogen into electricity. These expensive precious-metal catalysts comprise upwards of 50% of the PEFC cost, and will undergo detrimental performance loss during long periods of operation. It is therefore the holy grail of fuel cell research to develop catalysts that can operate with high efficiency and stability, while achieving cost savings by reducing the platinum content. This dissertation makes significant strides towards these objectives. In the first portion of work, platinum-alloy nanowire catalysts are developed. In this regard, the platinum content of the catalyst is diluted by less expensive cobalt atoms, with a simultaneous boost in efficiency. In fact, these catalysts achieved a 7-fold performance increase over state-of-the-art materials. In the second portion of the dissertation, completely precious-metal free catalysts containing cobalt sulfide particles on graphene are reported. These materials were the best performing transition metal chalcogenide catalysts reported to date, with the potential to achieve large cost savings by completely replacing platinum. These approaches effectively address the efficiency, stability and cost challenges facing conventional fuel cell catalysts, and are expected to play an important role towards achieving sustainability of the transportation sector.
THE 2016 CAGS/PROQUEST DISTINGUISHED DISSERTATION AWARD WINNER IN THE CATEGORY OF FINE ARTS, HUMANITIES AND SOCIAL SCIENCES
Dr. Douglas Hunter York University
Stone of Power: Dighton Rock, Colonization and the Erasure of an Indigenous Past
This dissertation examines the historiography of Dighton Rock, one of the most contested artifacts of American antiquity. Since first being described in 1680, the forty-ton boulder on the east bank of the Taunton River in Massachusetts has been the subject of endless speculation over who created its markings or “inscription.” Interpretations have included Vikings, Phoenicians and visitors from Atlantis. In its latest incarnation the rock is celebrated in a dedicated state park museum as an artifact of a lost Portuguese explorer, Miguel Colte-Real. I accept the Indigenaiety of its essential markings, which has never been seriously contested, and show how antiquarians and scholars into the twentieth century pursued an eccentric range of Old World attributions. I contend that the misattribution of Dighton Rock (and other Indigenous petroglyphs, as well as the so-called Mound Builder materials) has been part of the larger Euro-American/ Anglo-American colonization project and its centuries-long conceptualization of Indigenous peoples. As with colonization itself, the rock’s historiography is best understood through the criteria of belonging, possession and dispossession. The rock’s historiography not only reflects that colonization project and its shifting priorities over time, but its interpretation has also played a significant role in defining and advancing it. By disenfranchising Indigenous peoples from their own past in the interpretations of Dighton Rock and other seeming archaeological puzzles, colonizers have sought to answer to their own advantage two fundamental questions: to whom does America belong, and who belongs in America?