3,422 research outputs found

    Suicide under Workmen\u27s Compensation Laws

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    No jurisdiction allows a death claim for suicide according to the strict definition of the term. When death benefits are paid to a decedent\u27s dependents for death produced by his own hand, the term self-destruction rather than suicide is applicable. To allow recovery, all jurisdictions require that the decedent be subject to some mental derangement at the time of the commission of the act. It is the degree of derangement required, the manifestation of it, and the causal relationship of it to the compensable injury which create problems

    Suicide under Workmen\u27s Compensation Laws

    Get PDF
    No jurisdiction allows a death claim for suicide according to the strict definition of the term. When death benefits are paid to a decedent\u27s dependents for death produced by his own hand, the term self-destruction rather than suicide is applicable. To allow recovery, all jurisdictions require that the decedent be subject to some mental derangement at the time of the commission of the act. It is the degree of derangement required, the manifestation of it, and the causal relationship of it to the compensable injury which create problems

    A DSMC investigation of gas flows in micro-channels with bends

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    Pressure-driven, implicit boundary conditions are implemented in an open source direct simulation Monte Carlo (DSMC) solver, and benchmarked against simple micro-channel flow cases found in the literature. DSMC simulations are then carried out of gas flows for varying degrees of rarefaction along micro-channels with both one and two ninety-degree bends. The results are compared to those from the equivalent straight micro-channel geometry. Away from the immediate bend regions, the pressure and Mach number profiles do not differ greatly from those in straight channels, indicating that there are no significant losses introduced when a bend is added to a micro-channel geometry. It is found that the inclusion of a bend in a micro-channel can increase the amount of mass that a channel can carry, and that adding a second bend produces a greater mass flux enhancement. This increase happens within a small range of Knudsen number (0.02 Knin 0.08). Velocity slip and shear stress profiles at the channel walls are presented for the Knudsen showing the largest mass flux enhancement

    Development of a two-temperature open source CFD model for hypersonic reacting flows

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    The highly complex flow physics that characterise re-entry conditions have to be reproduced by means of numerical simulations with both an acceptable level of accuracy and within reasonable timescales. In this respect, a new CFD solver, hyFoam, has been developed within the framework of the open-source CFD platform OpenFOAM for modelling hypersonic reacting flows. hyFoam has been successfully validated for two 0-degree adiabatic heat bath test cases and the limitations of a one-temperature CFD model have been highlighted. To cope with high-temperature gas chemistry, the internal energy has been decomposed into its elementary energy modes, thus introducing the translational-rotational and the vibrational temperatures. A two-temperature CFD model is being implemented in order to attain a better agreement between CFD and DSMC results. Validation of the code for a single species has been executed while mixture-related libraries are currently being developed. The vibrational-translational relaxation time formulation has also been presented and discussed

    A two-temperature open-source CFD model for hypersonic reacting flows, part two : multi-dimensional analysis

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    hy2Foam is a newly-coded open-source two-temperature computational fluid dynamics (CFD) solver that has previously been validated for zero-dimensional test cases. It aims at (1) giving open-source access to a state-of-the-art hypersonic CFD solver to students and researchers; and (2) providing a foundation for a future hybrid CFD-DSMC (direct simulation Monte Carlo) code within the OpenFOAM framework. This paper focuses on the multi-dimensional verification of hy2Foam and firstly describes the different models implemented. In conjunction with employing the coupled vibration-dissociation-vibration (CVDV) chemistry–vibration model, novel use is made of the quantum-kinetic (QK) rates in a CFD solver. hy2Foam has been shown to produce results in good agreement with previously published data for a Mach 11 nitrogen flow over a blunted cone and with the dsmcFoam code for a Mach 20 cylinder flow for a binary reacting mixture. This latter case scenario provides a useful basis for other codes to compare against

    Chemically reacting hypersonic flows over 3D cavities : flowfield structure characterisation

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    In this paper, a computational investigation of hypersonic rarefied gas flows in the transitional flow regime over 3D cavities is carried out by using the direct simulation Monte Carlo method. Such cavities give rise to geometric discontinuities that are often present at the surface of reentry vehicles. This work is focused on the flowfield structure characterisation under a rarefied environment and in the presence of chemical reactions. The cavities are investigated with different length-to-depth ratios, and the different flow structures are studied. In particular, for length-to-depth ratios of 1 and 2, a single recirculation is observed inside the cavities and the main flow is not able to enter the cavity due to the recirculation structure and high particle density. In the case of length-to-depth ratio 3, the flow is able to partially enter the cavity resulting in an elongated recirculation and the beginning of a secondary recirculation core is noticed. For the case of values 4 and 5, the main flow is able to penetrate deeper into the cavities and two recirculation zones are observed; however, for the length-to-depth ratio 5 the flow impinges directly on the bottom surface, which is a behaviour that is only observed in the continuum regime with a cavity length-to-depth ratio greater than 14

    Bioengineered Lysozyme Reduces Bacterial Burden and Inflammation in a Murine Model of Mucoid Pseudomonas aeruginosa Lung Infection

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    The spread of drug-resistant bacterial pathogens is a growing global concern and has prompted an effort to explore potential adjuvant and alternative therapies derived from nature\u27s repertoire of bactericidal proteins and peptides. In humans, the airway surface liquid layer is a rich source of antibiotics, and lysozyme represents one of the most abundant and effective antimicrobial components of airway secretions. Human lysozyme is active against both Gram-positive and Gram-negative bacteria, a

    A kinetic model of the Boltzmann equation for non-vibrating polyatomic gases

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    A kinetic model of the Boltzmann equation for non-vibrating polyatomic gases is proposed, based on the Rykov model for diatomic gases. We adopt two velocity distribution functions (VDFs) to describe the system state; inelastic collisions are the same as in the Rykov model, but elastic collisions are modelled by the Boltzmann collision operator (BCO) for monatomic gases, so that the overall kinetic model equation reduces to the Boltzmann equation for monatomic gases in the limit of no translational–rotational energy exchange. The free parameters in the model are determined by comparing the transport coefficients, obtained by a Chapman–Enskog expansion, to values from experiment and kinetic theory. The kinetic model equations are solved numerically using the fast spectral method for elastic collision operators and the discrete velocity method for inelastic ones. The numerical results for normal shock waves and planar Fourier/Couette flows are in good agreement with both conventional direct simulation Monte Carlo (DSMC) results and experimental data. Poiseuille and thermal creep flows of polyatomic gases between two parallel plates are also investigated. Finally, we find that the spectra of both spontaneous and coherent Rayleigh–Brillouin scattering (RBS) compare well with DSMC results, and the computational speed of our model is approximately 300 times faster. Compared to the Rykov model, our model greatly improves prediction accuracy, and reveals the significant influence of molecular models. For coherent RBS, we find that the Rykov model could overpredict the bulk viscosity by a factor of two
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