1,133 research outputs found

    Stygiophobia and Other Fears of Death and Loneliness: Collected Fiction

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    This creative thesis is comprised of five short stories and an introduction, which details artistic influences and other factors related to writing. The first story, Through the Electronic Looking Glass, is a story simultaneously about a dissolving relationship and the intersection between art and commerce. \u27\u27Stygiophobia, the title work of the collection meaning fear of hell, deals with a Christian protestor\u27 s experience at a gay pride parade. So Damned Civilized tells the story of an office dinner party gone horribly wrong and gives a glimpse into the evils of human nature. Affliction, at its core, is about a zombie apocalypse and its effects on a suburban strip mall, but it also explores whether people can put aside their differences for the common good ... during an election season. Finally, Love, Backwards centers around a teenage girl and her deceased sister\u27s boyfriend and the ways in which the two of them cope with loss. All of the stories are tied together by either the threat of death (from zombies, the afterlife, and car accidents) or loneliness (from infidelity, rejection, and moving away), and that both of these concepts embody a sort of hell for the stories\u27 characters. I feel that each story highlights my achievements in Brockport\u27s Creative Writing M.A. program

    Particle-in-cell simulation of a mildly relativistic collision of an electron-ion plasma carrying a quasi-parallel magnetic field: Electron acceleration and magnetic field amplification at supernova shocks

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    Plasma processes close to SNR shocks result in the amplification of magnetic fields and in the acceleration of electrons, injecting them into the diffusive acceleration mechanism. The acceleration of electrons and the B field amplification by the collision of two plasma clouds, each consisting of electrons and ions, at a speed of 0.5c is investigated. A quasi-parallel guiding magnetic field, a cloud density ratio of 10 and a plasma temperature of 25 keV are considered. A quasi-planar shock forms at the front of the dense plasma cloud. It is mediated by a circularly left-hand polarized electromagnetic wave with an electric field component along the guiding magnetic field. Its propagation direction is close to that of the guiding field and orthogonal to the collision boundary. It has a low frequency and a wavelength that equals several times the ion inertial length, which would be indicative of a dispersive Alfven wave close to the ion cyclotron resonance frequency of the left-handed mode (ion whistler), provided that the frequency is appropriate. However, it moves with the super-alfvenic plasma collision speed, suggesting that it is an Alfven precursor or a nonlinear MHD wave such as a Short Large-Amplitude Magnetic Structure (SLAMS). The growth of the magnetic amplitude of this wave to values well in excess of those of the quasi-parallel guiding field and of the filamentation modes results in a quasi-perpendicular shock. We present evidence for the instability of this mode to a four wave interaction. The waves developing upstream of the dense cloud give rise to electron acceleration ahead of the collision boundary. Energy equipartition between the ions and the electrons is established at the shock and the electrons are accelerated to relativistic speeds.Comment: 16 pages, 18 figures, Accepted for publication by Astron & Astrophy

    Recollimation Shocks in Magnetized Relativistic Jets

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    We have performed two-dimensional special-relativistic magnetohydrodynamic simulations of non-equilibrium over-pressured relativistic jets in cylindrical geometry. Multiple stationary recollimation shock and rarefaction structures are produced along the jet by the nonlinear interaction of shocks and rarefaction waves excited at the interface between the jet and the surrounding ambient medium. Although initially the jet is kinematically dominated, we have considered axial, toroidal and helical magnetic fields to investigate the effects of different magnetic-field topologies and strengths on the recollimation structures. We find that an axial field introduces a larger effective gas-pressure and leads to stronger recollimation shocks and rarefactions, resulting in larger flow variations. The jet boost grows quadratically with the initial magnetic field. On the other hand, a toroidal field leads to weaker recollimation shocks and rarefactions, modifying significantly the jet structure after the first recollimation rarefaction and shock. The jet boost decreases systematically. For a helical field, instead, the behaviour depends on the magnetic pitch, with a phenomenology that ranges between the one seen for axial and toroidal magnetic fields, respectively. In general, however, a helical magnetic field yields a more complex shock and rarefaction substructure close to the inlet that significantly modifies the jet structure. The differences in shock structure resulting from different field configurations and strengths may have observable consequences for disturbances propagating through a stationary recollimation shock.Comment: 14 pages, 15 figures and 1 table, accepted for publication in Ap

    Solving Nonlinear Systems of Equations Via Spectral Residual Methods: Stepsize Selection and Applications

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    Spectral residual methods are derivative-free and low-cost per iteration procedures for solving nonlinear systems of equations. They are generally coupled with a nonmonotone linesearch strategy and compare well with Newton-based methods for large nonlinear systems and sequences of nonlinear systems. The residual vector is used as the search direction and choosing the steplength has a crucial impact on the performance. In this work we address both theoretically and experimentally the steplength selection and provide results on a real application such as a rolling contact problem

    Parent career modeling: keeping middle school students on the track to successful careers

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    This study reports the results of regression analyses that examined the contribution of parent career modeling to the outcomes of student engagement, school valuing, and future time perspective. The study was conducted with 6th grade students, who were surveyed at both the beginning of the school-year and at the end of the school-year using self-report scale items for the independent and dependent constructs. Baseline levels and demographic variables, such as gender, socioeconomic status, family structure, and race were controlled for in the regression analysis to determine the unique contribution by parent career modeling. It was found that parent career modeling contributes significantly to all three of the dependent variables. This study provides evidence for using parent career modeling in interventions aimed at increasing student engagement, student valuing of school, and future time perspective

    Development and validation of wear models by using innovative three-dimensional laser scanners:

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    One of the main problems in railway and tramway systems, both dynamically (safety, comfort etc.) and economically (planning of maintenance interventions, reduction of wheel and rail lifetime etc.), is represented by the wear of wheel and rail profiles, due to the wheel–rail interaction. The profile's shape variation caused by wear influences the dynamic behaviour of the vehicle and, in particular, the wheel–rail contact conditions. Hence, nowadays, one of the most important topics in the railway field is the development of reliable wear models to predict profiles evolution, together with the use of more efficient and accurate measuring instruments for the model validation and the rolling components inspection. In this context, the aim of this research work is the development and the validation of wear models, using experimental data acquired through an innovative measuring instrument based on noncontact three-dimensional laser scanning technology. The tramway line of the city of Florence, characterized by very narrow curves and critical in terms of wear, has been chosen as a reference test case. Moreover, the inspection procedures currently adopted on this line for the maintenance plan are based only on classical two-dimensional contact measurement systems, not so accurate for a complete wear assessment. Therefore, the introduction of a new three-dimensional laser scanning technology may have a great impact on the maintenance management of the line
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