718 research outputs found

    Sensitivity to oscillation with a sterile fourth generation neutrino from ultralow threshold neutrino-nucleus coherent scattering

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    We discuss prospects for probing short-range sterile neutrino oscillation using neutrino-nucleus coherent scattering with ultra-low energy (∌10\sim 10 eV - 100 eV) recoil threshold cryogenic Ge detectors. The analysis is performed in the context of a specific and contemporary reactor-based experimental proposal, developed in cooperation with the Nuclear Science Center at Texas A\&M University, and references developing technology based upon economical and scalable detector arrays. The baseline of the experiment is substantially shorter than existing measurements, as near as about 2 meters from the reactor core, and is moreover variable, extending continuously up to a range of about 10 meters. This proximity and variety combine to provide extraordinary sensitivity to a wide spectrum of oscillation scales, while facilitating the tidy cancellation of leading systematic uncertainties in the reactor source and environment. With 100~eV sensitivity, for exposures on the order of 200 kg⋅\cdoty, we project an estimated sensitivity to first/fourth neutrino oscillation with a mass gap Δm2∌1 eV2\Delta m^2 \sim 1 \, {\rm eV}^2 at an amplitude sin⁥22Ξ∌10−1\sin^2 2\theta \sim 10^{-1}, or Δm2∌0.2 eV2\Delta m^2 \sim 0.2 \, {\rm eV}^2 at unit amplitude. Larger exposures, around 5,000 kg⋅\cdoty, together with 10 eV sensitivity are capable of probing more than an additional order of magnitude in amplitude.Comment: 4 figures, PRD version, New author added, analysis updated with stat. estimates based on new measurements and simulation

    Sunny windy Sundays

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    Rapid expansion of wind and solar capacity in Great Britain presents challenges for managing electricity systems. One concern is the reduction in system inertia during periods where renewables provide a high proportion of demand which has led to some networks imposing system nonsynchronous penetration limits. However, given the lack of operational data, the relationship between renewable generation and demand for the full range of meteorological conditions experienced in Great Britain is poorly understood. This study uses reanalysis datasets to determine the proportion of demand from renewable generation on an hourly resolution for a 36-year period. The days with highest penetration of renewables tend to be sunny, windy weekend days between May and September, when there is a significant contribution of both wind and solar generation and demand is suppressed due to human behaviour. Based on the current distribution of wind and solar capacity, there is very little curtailment for all system non-synchronous penetration limits considered. However, as installed capacity of renewables grows the volume of generation curtailed also increases with a disproportionate volume occurring at weekends. The total volume of curtailment is highly dependent on ratio of wind and solar capacity, with the current blend close to the optimum level

    Optimasi Portofolio Resiko Menggunakan Model Markowitz MVO Dikaitkan dengan Keterbatasan Manusia dalam Memprediksi Masa Depan dalam Perspektif Al-Qur`an

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    Risk portfolio on modern finance has become increasingly technical, requiring the use of sophisticated mathematical tools in both research and practice. Since companies cannot insure themselves completely against risk, as human incompetence in predicting the future precisely that written in Al-Quran surah Luqman verse 34, they have to manage it to yield an optimal portfolio. The objective here is to minimize the variance among all portfolios, or alternatively, to maximize expected return among all portfolios that has at least a certain expected return. Furthermore, this study focuses on optimizing risk portfolio so called Markowitz MVO (Mean-Variance Optimization). Some theoretical frameworks for analysis are arithmetic mean, geometric mean, variance, covariance, linear programming, and quadratic programming. Moreover, finding a minimum variance portfolio produces a convex quadratic programming, that is minimizing the objective function ðð„with constraintsð ð ð„ „ ðandðŽð„ = ð. The outcome of this research is the solution of optimal risk portofolio in some investments that could be finished smoothly using MATLAB R2007b software together with its graphic analysis

    Differential cross section measurements for the production of a W boson in association with jets in proton–proton collisions at √s = 7 TeV