41 research outputs found

    Assessing the sociology of sport: On race and diaspora

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    © The Author(s) 2014 On the 50th anniversary of the ISSA and IRSS, a key foundational scholar on the intersection of race and sport, Ben Carrington, reflects on the field as a whole and the notion of “diaspora” in understanding race and sport. In considering the trajectory of the sociology of sport, questions are raised about whether a coherent field has ever existed. Noting relative failures in getting “mainstream sociology” to take sport seriously, the challenges ahead are for a field that is necessarily a “multifaceted” entity, and one that ironically has never been more impactful while at its weakest institutional moment. Noting the paradox between the relative little consideration given to sport in the main sociology journals in the US and UK in contrast with the sociology of sport having successfully established self-reproducing and self-referencing spaces of critical enquiry, a key challenge for the field continues to be in its search for a “scholarly place;” it is less than clear whether the banner of “the sociology of sport” continues to resonate in the face of the neo-liberal assaults on critical scholarship within higher education. The concept of “diaspora,” surprisingly ignored in the study of sport, will be increasingly important in the future as it will enable critical race scholars to problematize the often Eurocentric and teleological underpinning of globalization theory in relation to sport; considerations of diaspora will fuel more meaningful accounts of how sport reconnects geographically dispersed groups and changes identities and subjectivities in hostile circumstances

    Detailed Multi-dimensional Modeling of Direct Internal Reforming Solid Oxide Fuel Cells

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    Fuel flexibility is a significant advantage of solid oxide fuel cells (SOFCs) and can be attributed to their high operating temperature. Here we consider a direct internal reforming solid oxide fuel cell setup in which a separate fuel reformer is not required. We construct a multidimensional, detailed model of a planar solid oxide fuel cell, where mass transport in the fuel channel is modeled using the Stefan-Maxwell model, whereas the mass transport within the porous electrodes is simulated using the Dusty-Gas model. The resulting highly nonlinear model is built into COMSOL Multiphysics, a commercial computational fluid dynamics software, and is validated against experimental data from the literature. A number of parametric studies is performed to obtain insights on the direct internal reforming solid oxide fuel cell system behavior and efficiency, to aid the design procedure. It is shown that internal reforming results in temperature drop close to the inlet and that the direct internal reforming solid oxide fuel cell performance can be enhanced by increasing the operating temperature. It is also observed that decreases in the inlet temperature result in smoother temperature profiles and in the formation of reduced thermal gradients. Furthermore, the direct internal reforming solid oxide fuel cell performance was found to be affected by the thickness of the electrochemically-active anode catalyst layer, although not always substantially, due to the counter-balancing behavior of the activation and ohmic overpotentials

    A Model for the Mass and Distribution of Particles in Dark Matter Halos

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    This model is intended for dark-matter-dominated galaxies and galaxy clusters for which the centrifugal force caused by system rotation is negligible. Such systems, ostensibly dark matter halos, would tend to be spherical. Consider a uniform sphere of identical, massive particles in equilibrium (not contracting or expanding). In the quantum model, gravitation pulls the particles together and quantum uncertainty pushes them apart. In the corresponding classical model, gravitation pulls the particles together and thermal motion pushes them apart. This model provides an expression for particle mass as a function of the total mass and density of the system and its quantum state or temperature. Using the measured total mass and density of our dark-matter-dominated galaxy, and assuming the system is in the ground state, the particle mass is found to be 10.5 eV and the temperature 0.042 K. This represents the lowest possible system temperature and particle mass. If, on the other hand, the system is in equilibrium with the cosmic microwave background, the particle mass is found to be 693 eV. This range of inferred particle masses supports the hypothesis of “low-mass dark matter” with approximate mass 100 eV. However, the system temperature is not presently known so it is possible that the temperature is higher and, consequently, the particles are heavier. The average speed of the particles is found to be approximately 1/1000th the speed of light in our galaxy. Remarkably, this result does not depend on the system temperature and, therefore, does not depend on the particle mass. The extension of this model to variable density provides a straightforward solution to the “core-cusp problem” because the distribution of dark matter that minimizes the system energy has a flat central dark matter density profile.The accepted manuscript in pdf format is listed with the files at the bottom of this page. The presentation of the authors' names and (or) special characters in the title of the manuscript may differ slightly between what is listed on this page and what is listed in the pdf file of the accepted manuscript; that in the pdf file of the accepted manuscript is what was submitted by the author
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