138 research outputs found

    Towards cleaner production: a roadmap for predicting product end-of-life costs at early design concept

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    The primary objective of the research was to investigate how disposal costs were being incurred in the domain of defence electronic systems by the Original Equipment Manufacturer (OEM) and subsequently to ascertain a novel approach to prediction of their end-of-life (EOL) costs. It is intended that the OEM could utilise this method as part of a full lifecycle cost analysis at the conceptual design stage. The cost model would also serve as a useful guide to aid decision making at the conceptual design stage, so that it may lead to the design of a more sustainable product in terms of recycling, refurbishment or remanufacture with the consideration of financial impact. The novelty of this research is that it identifies the significance of disposal costs from the viewpoint of the OEM and provides a generic basis for evaluation of all the major EOL defence electronic systems. A roadmap has been proposed and developed to facilitate the prediction of disposal costs and this will be used to determine a satisfactory solution of whether the EOL parts of a defence electronic system are viable to be remanufactured, refurbished or recycled from an early stage of a design concept. A selected defence electronic system is used as a case study. Based on the findings, the proposed method offers a manageable and realistic solution so that the OEM can estimate the cost of potential EOL recovery processes at the concept design stag

    A precise measurement of the magnetic field in the corona of the black hole binary V404 Cygni

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    Observations of binary stars containing an accreting black hole or neutron star often show x-ray emission extending to high energies (>10 kilo­–electron volts), which is ascribed to an accretion disk corona of energetic particles akin to those seen in the solar corona. Despite their ubiquity, the physical conditions in accretion disk coronae remain poorly constrained. Using simultaneous infrared, optical, x-ray, and radio observations of the Galactic black hole system V404 Cygni, showing a rapid synchrotron cooling event in its 2015 outburst, we present a precise 461 ± 12 gauss magnetic field measurement in the corona. This measurement is substantially lower than previous estimates for such systems, providing constraints on physical models of accretion physics in black hole and neutron star binary systems. This article has a correction. Please see: http://science.sciencemag.org/content/360/6386/eaat927

    A New Definition of Learning Disabilities

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    Learning disabilities is a generic term that refers to a heterogeneous group of disorders manifested by significant difficulties in the acquisition and use of listening, speaking, reading, writing, reasoning or mathematical abilities. These disorders are intrinsic to the individual and presumed to be due to central nervous system dysfunction. Even though a learning disability may occur concomitantly with other handicapping conditions (e.g., sensory impairment, mental retardation, social and emotional disturbance) or environmental influences (e.g., cultural differences, insufficient/inappropriate instruction, psychogenic factors), it is not the direct result of those conditions or influences.Yeshttps://us.sagepub.com/en-us/nam/manuscript-submission-guideline

    K-Shell photodetachment of Li−: Experiment and theory

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    We have measured the first and second moments of the hadronic mass-squared distribution in B→Xclv, for Plepton>1.5 GeV/c. We find(MX 2−MD −2)= 0.251 ± 0.66 GeV2,((MX 2−MX 2)2)=0.576 ± 0.170 GeV4, where MÂŻ Dis the spin-averaged D meson mass. From that first moment and the first moment of the photon energy spectrum in b→s Îł, we find the heavy quark effective theory parameter λ1(in the modified minimal subtraction renormalization scheme, to order 1/MB 3and Îł0αs 2) to be −0.24±0.11GeV2. Using these first moments and the B semileptonic width, and assuming parton-hadron duality, we obtain|Vcb|=0.0404±0.0013

    Improved upper limits on the flavor-changing neutral current decays B→Kℓ+ℓ- and B→K*(892)ℓ+ℓ-

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    We have searched a sample of 9.6×106 B¯B events for the flavor-changing neutral current decays B→Kℓ+ℓ- and B→K*(892)ℓ+ℓ-. We subject the latter decay to the requirement that the dilepton mass mℓℓ exceed 0.5 GeV. There is no indication of a signal. We obtain the 90% confidence level upper limits B(B→Kℓ+ℓ-) 0.5Gev0.5Gev < 1.5×10-6. The weighted-average limit is only 50% above the standard model prediction

    Measurement of the muon flux from 400 GeV/c protons interacting in a thick molybdenum/tungsten target

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    The SHiP experiment is proposed to search for very weakly interacting particles beyond the Standard Model which are produced in a 400 GeV/c proton beam dump at the CERN SPS. About 1011 muons per spill will be produced in the dump. To design the experiment such that the muon-induced background is minimized, a precise knowledge of the muon spectrum is required. To validate the muon flux generated by our Pythia and GEANT4 based Monte Carlo simulation (FairShip), we have measured the muon flux emanating from a SHiP-like target at the SPS. This target, consisting of 13 interaction lengths of slabs of molybdenum and tungsten, followed by a 2.4 m iron hadron absorber was placed in the H4 400 GeV/c proton beam line. To identify muons and to measure the momentum spectrum, a spectrometer instrumented with drift tubes and a muon tagger were used. During a 3-week period a dataset for analysis corresponding to (3.27±0.07) × 1011 protons on target was recorded. This amounts to approximatively 1% of a SHiP spill
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