2,117 research outputs found

    A Suite of Reduced-Order Models of a Single-Layer Lithium-ion Pouch Cell

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    For many practical applications, fully coupled three-dimensional models describing the behaviour of lithium-ion pouch cells are too computationally expensive. However, owing to the small aspect ratio of typical pouch cell designs, such models are well approximated by splitting the problem into a model for through-cell behaviour and a model for the transverse behaviour. In this paper, we combine different simplifications to through-cell and transverse models to develop a hierarchy of reduced-order pouch cell models. We give a critical numerical comparison of each of these models in both isothermal and thermal settings, and also study their performance on realistic drive cycle data. Finally, we make recommendations regarding model selection, taking into account the available computational resource and the quantities of interest in a particular study

    Incorporating Ambipolar and Ohmic Diffusion in the AMR MHD code RAMSES

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    We have implemented non-ideal Magneto-Hydrodynamics (MHD) effects in the Adaptive Mesh Refinement (AMR) code RAMSES, namely ambipolar diffusion and Ohmic dissipation, as additional source terms in the ideal MHD equations. We describe in details how we have discretized these terms using the adaptive Cartesian mesh, and how the time step is diminished with respect to the ideal case, in order to perform a stable time integration. We have performed a large suite of test runs, featuring the Barenblatt diffusion test, the Ohmic diffusion test, the C-shock test and the Alfven wave test. For the latter, we have performed a careful truncation error analysis to estimate the magnitude of the numerical diffusion induced by our Godunov scheme, allowing us to estimate the spatial resolution that is required to address non-ideal MHD effects reliably. We show that our scheme is second-order accurate, and is therefore ideally suited to study non-ideal MHD effects in the context of star formation and molecular cloud dynamics

    Report of the GDR working group on the R-parity violation

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    This report summarizes the work of the "R-parity violation group" of the French Research Network (GDR) in Supersymmetry, concerning the physics of supersymmetric models without conservation of R-parity at HERA, LEP, Tevatron and LHC and limits on R-parity violating couplings from various processes. The report includes a discussion of the recent searches at the HERA experiment, prospects for new experiments, a review of the existing limits, and also theoretically motivated alternatives to R-parity and a brief discussion on the implications of R-parity violation on the neutrino masses.Comment: 60 pages, LaTeX, 22 figures, 2 table

    Measuring the quality of family-professional partnerships in special education services

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    This is the published version, also found here: http://cec.metapress.com/content/jr8655lg61k1n440/?p=edbc223bb2fb4291b6b55663014711a2&pi=3One difficulty in monitoring the quality of family-professional partnerships has been the lack of a psychometrically acceptable and sufficiently general instrument with which to assess them. The current work describes the development of the Family-Professional Partnership Scale, which assesses parents' perceptions of the importance of and their satisfaction with family-professional partnerships. Indicators were constructed from qualitative research on families with children with and without disabilities, and the scale was refined across two field tests that included families with children with a wide range of ages and disability types and severity. Both the 18-item overall scale and the two 9-item subscales demonstrated excellent psychometric properties. The possible uses of this scale in future research and service delivery are discus

    Multi-Periodic Oscillations in Cepheids and RR Lyrae-Type Stars

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    Classical Cepheids and RR Lyrae-type stars are usually considered to be textbook examples of purely radial, strictly periodic pulsators. Not all the variables, however, conform to this simple picture. In this review I discuss different forms of multi-periodicity observed in Cepheids and RR Lyrae stars, including Blazhko effect and various types of radial and nonradial multi-mode oscillations.Comment: Proceedings of the 20th Stellar Pulsation Conference Series: "Impact of new instrumentation & new insights in stellar pulsations", 5-9 September 2011, Granada, Spai
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