Waterloo, Canada

University of Waterloo

uwaterloo.ca/
Waterloo, Canada

University of Waterloo is a public research university whose main campus is located in Waterloo, Ontario, Canada. The main campus is located on 400 hectares of land in Uptown Waterloo, adjacent to Waterloo Park. The university offers a wide variety of academic programs, which is administered by six faculties, and three affiliated university colleges. Waterloo is a member of the U15, a group of research-intensive universities in Canada. Wikipedia.

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The present invention relates to core-shell particles, each particle comprising(A) a core comprising elemental sulfur and(B) a shell, which enwraps core (A), comprising MnO_(2). The present invention further relates to a process for preparing said core-shell particles, to a cathode material for an electrochemical cell comprising said core-shell particles, and to a cathode and an electrochemical cell comprising said cathode materials.


Risko E.F.,University of Waterloo | Gilbert S.J.,University College London
Trends in Cognitive Sciences | Year: 2016

If you have ever tilted your head to perceive a rotated image, or programmed a smartphone to remind you of an upcoming appointment, you have engaged in cognitive offloading: the use of physical action to alter the information processing requirements of a task so as to reduce cognitive demand. Despite the ubiquity of this type of behavior, it has only recently become the target of systematic investigation in and of itself. We review research from several domains that focuses on two main questions: (i) what mechanisms trigger cognitive offloading, and (ii) what are the cognitive consequences of this behavior? We offer a novel metacognitive framework that integrates results from diverse domains and suggests avenues for future research. © 2016 Elsevier Ltd


Denison S.,University of Waterloo
Cognition | Year: 2013

We present a proposal-"The Sampling Hypothesis"-suggesting that the variability in young children's responses may be part of a rational strategy for inductive inference. In particular, we argue that young learners may be randomly sampling from the set of possible hypotheses that explain the observed data, producing different hypotheses with frequencies that reflect their subjective probability. We test the Sampling Hypothesis with four experiments on 4- and 5-year-olds. In these experiments, children saw a distribution of colored blocks and an event involving one of these blocks. In the first experiment, one block fell randomly and invisibly into a machine, and children made multiple guesses about the color of the block, either immediately or after a 1-week delay. The distribution of guesses was consistent with the distribution of block colors, and the dependence between guesses decreased as a function of the time between guesses. In Experiments 2 and 3 the probability of different colors was systematically varied by condition. Preschoolers' guesses tracked the probabilities of the colors, as should be the case if they are sampling from the set of possible explanatory hypotheses. Experiment 4 used a more complicated two-step process to randomly select a block and found that the distribution of children's guesses matched the probabilities resulting from this process rather than the overall frequency of different colors. This suggests that the children's probability matching reflects sophisticated probabilistic inferences and is not merely the result of a naïve tabulation of frequencies. Taken together the four experiments provide support for the Sampling Hypothesis, and the idea that there may be a rational explanation for the variability of children's responses in domains like causal inference. Copyright © 2012 Elsevier B.V. All rights reserved.


Turri J.,University of Waterloo
Cognition | Year: 2013

Assertion is fundamental to our lives as social and cognitive beings. Philosophers have recently built an impressive case that the norm of assertion is factive. That is, you should make an assertion only if it is true. Thus far the case for a factive norm of assertion been based on observational data. This paper adds experimental evidence in favor of a factive norm from six studies. In these studies, an assertion's truth value dramatically affects whether people think it should be made. Whereas nearly everyone agreed that a true assertion supported by good evidence should be made, most people judged that a false assertion supported by good evidence should not be made. The studies also suggest that people are consciously aware of criteria that guide their evaluation of assertions. Evidence is also presented that some intuitive support for a non-factive norm of assertion comes from a surprising tendency people have to misdescribe cases of blameless rule-breaking as cases where no rule is broken. © 2013 Elsevier B.V.


Lamb K.G.,University of Waterloo
Annual Review of Fluid Mechanics | Year: 2014

Internal waves are important physical phenomena on the continental shelf/slope. They are often very energetic, and their breaking provides an important dissipation and mixing mechanism, with implications for biological productivity and sediment transport. Internal waves appear in a variety of forms and can break in a variety of ways. A consequence of their dispersion properties is the breaking of waves reflecting from, or being generated at, near-critical slopes. Breaking mechanisms associated with internal solitary waves include bottom boundary layer instabilities, shear instabilities in the interior of the water column, and wave overturning as they shoal. Shoaling can result in the formation of waves with trapped cores either at the surface or at the bottom. Theoretical, numerical, and laboratory studies have largely focused on simple geometries, whereas recent work has shown that the situation in the ocean is often much more complicated because of more complex geometries and the presence of a full hierarchy of fluid motions. Copyright © 2014 by Annual Reviews. All rights reserved.


Burkov A.A.,University of Waterloo
Physical Review Letters | Year: 2014

We present a theory of the anomalous Hall effect (AHE) in a doped Weyl semimetal, or Weyl metal, including both intrinsic and extrinsic (impurity scattering) contributions. We demonstrate that a Weyl metal is distinguished from an ordinary ferromagnetic metal by the absence of the extrinsic and the Fermi surface part of the intrinsic contributions to the AHE, as long as the Fermi energy is sufficiently close to the Weyl nodes. The AHE in a Weyl metal is thus shown to be a purely intrinsic, universal property, fully determined by the location of the Weyl nodes in the first Brillouin zone. © 2014 American Physical Society.


Lynch M.D.J.,University of Waterloo | Neufeld J.D.,University of Waterloo
Nature Reviews Microbiology | Year: 2015

The profound influence of microorganisms on human life and global biogeochemical cycles underlines the value of studying the biogeography of microorganisms, exploring microbial genomes and expanding our understanding of most microbial species on Earth: that is, those present at low relative abundance. The detection and subsequent analysis of low-abundance microbial populations-the 'rare biosphere'-have demonstrated the persistence, population dynamics, dispersion and predation of these microbial species. We discuss the ecology of rare microbial populations, and highlight molecular and computational methods for targeting taxonomic 'blind spots' within the rare biosphere of complex microbial communities. © 2015 Macmillan Publishers Limited.


Burkov A.A.,University of Waterloo
Physical Review Letters | Year: 2014

We present a microscopic theory of diffusive magnetotransport in Weyl metals and clarify its relation to the chiral anomaly. We derive coupled diffusion equations for the total and axial charge densities and show that the chiral anomaly manifests as a magnetic-field-induced coupling between them. We demonstrate that a universal experimentally observable consequence of this coupling in magnetotransport in Weyl metals is a quadratic negative magnetoresistance, which will dominate all other contributions to magnetoresistance under certain conditions. © 2014 American Physical Society.


Evers S.,University of Waterloo | Nazar L.F.,University of Waterloo
Accounts of Chemical Research | Year: 2013

The goal of replacing combustion engines or reducing their use presents a daunting problem for society. Current lithium-ion technologies provide a stepping stone for this dramatic but inevitable change. However, the theoretical gravimetric capacity (∼300 mA h g-1) is too low to overcome the problems of limited range in electric vehicles, and their cost is too high to sustain the commercial viability of electrified transportation. Sulfur is the one of the most promising next generation cathode materials. Since the 1960s, researchers have studied sulfur as a cathode, but only recently have great strides been made in preparing viable composites that can be used commercially. Sulfur batteries implement inexpensive, earth-abundant elements at the cathode while offering up to a five-fold increase in energy density compared with present Li-ion batteries.Over the past few years, researchers have come closer to solving the challenges associated with the sulfur cathode. Using carbon or conducting polymers, researchers have wired up sulfur, an excellent insulator, successfully. These conductive hosts also function to encapsulate the active sulfur mass upon reduction/oxidation when highly soluble lithium polysulfides are formed. These soluble discharge products remain a crux of the Li-S cell and need to be contained in order to increase cycle life and capacity retention. The use of mesoporous carbons and tailored designs featuring porous carbon hollow spheres have led to highly stable discharge capacities greater than 900 mA h g-1 over 100 cycles. In an attempt to fully limit polysulfide dissolution, methods that rely on coating carbon/sulfur composites with polymers have led to surprisingly stable capacities (∼90% of initial capacity retained). Additives will also play an important role in sulfur electrode design. For example, small fractions (> 3 wt%) of porous silica or titania effectively act as polysulfide reservoirs, decreasing their concentration in the electrolyte and leading to a higher utilization of sulfur and increased capacities. © 2012 American Chemical Society.


Clapp J.,University of Waterloo
Journal of Peasant Studies | Year: 2014

This paper provides a new perspective on the political implications of intensified financialization in the global food system. There has been a growing recognition of the role of finance in the global food system, in particular the way in which financial markets have become a mode of accumulation for large transnational agribusiness players within the current food regime. This paper highlights a further political implication of agrifood system financialization, namely how it fosters ‘distancing’ in the food system and how that distance shapes the broader context of global food politics. Specifically, the paper advances two interrelated arguments. First, a new kind of distancing has emerged within the global food system as a result of financialization that has (a) increased the number of the number and type of actors involved in global agrifood commodity chains and (b) abstracted food from its physical form into highly complex agricultural commodity derivatives. Second, this distancing has obscured the links between financial actors and food system outcomes in ways that make the political context for opposition to financialization especially challenging. © 2014 Taylor & Francis.

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