126,793 research outputs found

    Wear and Friction Modeling on Lifeboat Launch Systems

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    The RNLI provides search and rescue cover along the UK and RoI coast using a variety of lifeboats and launch techniques. In locations where there is no natural harbour it is necessary to use a slipway to launch the lifeboat into the sea. Lifeboat slipway stations consist of an initial section where the boat is held on rollers followed by an inclined keelway lined with low friction composite materials, the lifeboat is released from the top of the slipway and proceeds under its own weight into the water. The lifeboat is later recovered using a winch line. It is common to manually apply grease to the composite slipway lining before each launch and recovery in order to ensure sufficiently low friction for successful operation. With the introduction of the Tamar class lifeboat it is necessary to upgrade existing boathouses and standardise slipway operational procedures to ensure consistent operation. The higher contact pressures associated with the new lifeboat have led to issues of high friction and wear on the composite slipway linings and the manual application of grease to reduce friction is to be restricted due to environmental impact and cost factors. This paper presents a multidisciplinary approach to modelling slipway panel wear and friction using tribometer testing in conjunction with finite element analysis and slipway condition surveys to incorporate common real-world effects such as panel misalignments. Finally, it is shown that a freshwater lubrication system is effective, reducing cost and environmental impacts while maintaining good friction and wear performance

    Juvenile Probation Officer Workload and Caseload Study: Alaska Division of Juvenile Justice

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    This report describes results of a study to measure and analyze the workload and caseload of Juvenile Probation Officers (JPOs) within the Alaska Division of Juvenile Justice. More specifically, this study assessed the resources needed in both rural and urban Alaska to adequately meet minimum probation standards, to continue the development and enhancement of system improvements, and to fully implement the restorative justice field probation service delivery model.Bureau of Justice Assistance Grant No. 2008-IC-BX-K001Section I – Juvenile Probation Officer Workload and Caseload Study Table 1. Total Time Available by Office Figure 1. Referrals for New Offenses, by Depth of Processing Table 2. Average Caseloads by Office: FY06-08 Table 3. Summary Estimates for Hours Required per Type of Case Table 4. Final Results Table 5. Workload Burdens / Section II – Workload Elements Table 6. Total Time Available by Office Figure 2. Referrals for New Offenses, by Depth of Processing Table 7. Average Caseloads for Ultimate Probation Officers: FY06-08 Table 8. Average Caseloads for Immediate Probation Officers: FY06-08 Table 9. Summary Estimates for Hours Required per Type of Case / Section III – Workload Calculations Table 10. Total Hours Needed by Office Table 11. Total Hours Needed and Available by Office Table 12. Positions Needed by Office Table 13. Workload Burdens by Office Table 14. Summary of Final Results Table 15. Final Results with Average Times Required per Case Table 16. Final Results with Average Case Dispositions Table 17. Final Results with Average Times Required per Case and Case Dispositions Table 18. Summary of Final Results Table 19. Time Study Comparisons / Appendix A – Time Available Table A.1. Number of Positions by Region and Location Table A.2. Average Hours per Week Required for Other Activities Table A.3. Total Hours Available per Year by Position and Office / Appendix B – Number of Cases Figure B.1. Referrals for New Offenses, by Depth of Processing Table B.1. Average Caseloads for Ultimate Probation Officers: FY06-08 Table B.2. Average Caseloads for Immediate Probation Officers: FY06-08 / Appendix C – Time Required Table C.1. Summary Estimates for Hours Required per Type of Case Table C.2. Average Estimates (in Minutes) per Type of Case and Activity Table C.3. Detailed Estimates (in Minutes) for Time Required per Dismissed Case Table C.4. Detailed Estimates (in Minutes) for Time Required per Case Adjusted Without a Referral Table C.5. Detailed Estimates (in Minutes) for Time Required per Case Adjusted With a Referral Table C.6. Detailed Estimates (in Minutes) for Time Required per Informal Probation Case Table C.7. Detailed Estimates (in Minutes) for Time Required per Petitioned Cas

    The No-Boundary Measure of the Universe

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    We consider the no-boundary proposal for homogeneous isotropic closed universes with a cosmological constant and a scalar field with a quadratic potential. In the semi-classical limit, it predicts classical behavior at late times if the initial scalar field is more than a certain minimum. If the classical late time histories are extended back, they may be singular or bounce at a finite radius. The no-boundary proposal provides a probability measure on the classical solutions which selects inflationary histories but is heavily biased towards small amounts of inflation. This would not be compatible with observations. However we argue that the probability for a homogeneous universe should be multiplied by exp(3N) where N is the number of e-foldings of slow roll inflation to obtain the probability for what we observe in our past light cone. This volume weighting is similar to that in eternal inflation. In a landscape potential, it would predict that the universe would have a large amount of inflation and that it would start in an approximately de Sitter state near a saddle-point of the potential. The universe would then have always been in the semi-classical regime.Comment: 4 pages, revtex4, minor corrections to accord with published versio

    Vector Fields in Holographic Cosmology

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    We extend the holographic formulation of the semiclassical no-boundary wave function (NBWF) to models with Maxwell vector fields. It is shown that the familiar saddle points of the NBWF have a representation in which a regular, Euclidean asymptotic AdS geometry smoothly joins onto a Lorentzian asymptotically de Sitter universe through a complex transition region. The tree level probabilities of Lorentzian histories are fully specified by the action of the AdS region of the saddle points. The scalar and vector matter profiles in this region are complex from an AdS viewpoint, with universal asymptotic phases. The dual description of the semiclassical NBWF thus involves complex deformations of Euclidean CFTs.Comment: 17 pages, 3 fig

    Impact of Four-Quark Condensates on In-Medium Effects of Hadrons

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    Spectral properties of hadrons in nuclear matter are treated in the framework of QCD sum rules. The influence of the ambient strongly interacting medium is encoded in various condensates. Especially, the structure of different four-quark condensates and their density dependencies in light quark systems are exemplified for the omega meson and the nucleon.Comment: Contribution to Quark Confinement and the Hadron Spectrum VII, 02.-07.09.2006, Ponta Delgada, Portuga

    Four-quark condensates in open-charm chiral QCD sum rules

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    Recently, in Hilger et al. (2011) [1] QCD sum rules for chiral partners in the open-charm meson sector have been presented at nonzero baryon net density or temperature up to and including mass dimension 5. Referring to this, details concerning the cancelation of infrared divergences are presented and important technical and conceptional ingredients for an incorporation of four-quark condensates beyond factorization and of other mass dimension 6 condensates are collected.Comment: 7 pages, 5 figures, conference proceedin

    Electromagnetic Probes of Strongly Interacting Matter: Probes of Chiral Symmetry Restoration?

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    The QCD sum rule approach to in-medium modifications of the omega meson in nuclear matter is reviewed with emphasis of its relation to 4-quark condensates and chiral symmetry restoration. Possible implications of the CB-TAPS experiment for the reaction gamma A -> A' omega (-> pi0 gamma) are sketched and the particularly important role of di-electron probes, accessible with HADES, is highlighted. A brief update of a parametrization of the previous dilepton and photon probes from CERES and WA98 of heavy-ion collisions at CERN-SPS energies is presented.Comment: Contribution to Workshop on In-Medium Hadron Physics, Giessen, Nov. 11-13; 11 page
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