241 research outputs found

    Advanced Satellite Technique for Volcanic Activity Monitoring and Early Warning.

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    Nowadays, satellite remote sensing is an important tool for volcanic activity monitoring, thanks to several operational satellite platforms providing data everywhere with high observational frequencies and generally at low cost. Among different techniques available, an advanced satellite method, named RST (Robust Satellite Technique). based on the multitemporal analysis of satellite data, has shown a high capability in volcanic activity monitoring. This approach has proved capable of identifyimg and tracking volcanic ash Cloud and of correctly detecting and monitoring volcanic thermal anomalies. This paper analyzes some recent results, obtained applying this approach to the last eruptive events of Mt. Etna using both polar and geostationary satellites. In particular, for the first time, this approach is implemented on the present geostationary platform MSG-SEVIRI, with 15 min of temporal resolution. Preliminary results, together with a future potential of this implementation, are shown and discussed. Moreover, a differential RST index in time domain is also proposed for near real-time application, as a possible contribution to the development of an efficient early warning satellite system for volcanic hazard mitigation

    Advanced satellite technique for volcanic activity monitoring and early warning

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    Nowadays, satellite remote sensing is an important tool for volcanic activity monitoring, thanks to several operational satellite platforms providing data everywhere with high observational frequencies and generally at low cost. Among different techniques available, an advanced satellite method, named RST (Robust Satellite Technique), based on the multitemporal analysis of satellite data, has shown a high capability in volcanic activity monitoring. This approach has proved capable of identifying and tracking volcanic ash cloud and of correctly detecting and monitoring volcanic thermal anomalies. This paper analyzes some recent results, obtained applying this approach to the last eruptive events of Mt. Etna using both polar and geostationary satellites. In particular, for the first time, this approach is implemented on the present geostationary platform MSG-SEVIRI, with 15 min of temporal resolution. Preliminary results, together with a future potential of this implementation, are shown and discussed. Moreover, a differential RST index in time domain is also proposed for near real-time application, as a possible contribution to the development of an efficient early warning satellite system for volcanic hazard mitigation

    Anterior Segment-Optical Coherence Tomography features in Blau syndrome.

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    Blau syndrome (BS) is a rare granulomatous auto-inflammatory disease, characterized by the classic clinical triad of joints, skin and ocular involvements. Ocular manifestation usually consists in a bilateral insidious chronic anterior uveitis with a potential evolution to panuveitis. We describe the case of two siblings, an 8-years old female and a 5-years old male, with a diagnosis of BS, evaluated by Anterior Segment-Optical Coherence Tomography (AS-OCT). In the female patient, slit-lamp examination revealed bilateral anterior granulomatous uveitis and inflammatory sequelae. AS-OCT revealed high intensity reflective layers in the anterior cornea, hyperreflective dots both in the aqueous humor and in the posterior corneal surface. In the male, no signs of inflammation were detected both on slit-lamp examination and AS-OCT scans. AS-OCT is a valuable, non-invasive tool that could improve the diagnosis of ocular involvement, better characterize and follow-up corneal alterations and anterior segment features in pediatric patients with BS

    Methodological enhancements in MDO process investigated in the AGILE European project

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    This paper presents methodological investigations performed in research activities in the field of MDO in overall aircraft design in the ongoing EU funded research project AGILE. AGILE is developing the next generation of aircraft Multidisciplinary Design and Optimization processes, which target significant reductions in aircraft development costs and time to market, leading to cheaper and greener aircraft solutions. The paper introduces the AGILE project structure and describes the achievements of the 1st year (Design Campaign 1) leading to a reference distributed MDO system. A focus is then made on the different novel optimization techniques studied during the 2nd year, all willing to ease the optimization of complex work flows, characterized by high degree of discipline interdependencies, high number of design variables in the context of multi-level and multi-partner collaborative engineering projects. Then the implementation of these methods in the enhanced MDO framework is discussed

    A precise measurement of the non‐leptonic weak decay parameters α and ϕ in the spin 3/2 decay ω−→Λ0+K−

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    Experiment E800 at Fermilab using the E800 spectrometer has made a precise measurement of the non‐leptonic weak decay parameters for the spin 3/2 decay, Ω−→Δ°+K−. The paratmeters determined are αΎαΩ=0.0126±0.0042, αΩ=0.0196±0.0066, and ϕπ=−3.4°±10.3°. This measurement of αΩ is nearly four times more precise than the previous world average value of −0.026±0.026 and shows this parameter to be inconsistent with zero. Also, E800 has made the first measurement of ϕΩ. (AIP) © 1995 American Institute of Physics.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/87479/2/692_1.pd

    A precision measurement of the Ω− magnetic moment

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    The structure of baryons can be probed at long range by measuring their magnetic moments. The particulary simple valence quark structure (three strange quarks with their spins aligned) of the Ω− should make a precise measurments its magnetic moment a useful test of models of baryon structure. The only previous measurement of the Ω− magnetic moment to a precision of 10%, could not clearly differentiate between these models. © 1995 American Institute of Physics.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/87480/2/478_1.pd

    A first measurement of the interaction cross section of the tau neutrino

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    The DONuT experiment collected data in 1997 and published first results in 2000 based on four observed Μτ\nu_\tau charged-current (CC) interactions. The final analysis of the data collected in the experiment is presented in this paper, based on 3.6×10173.6 \times 10^{17} protons on target using the 800 GeV Tevatron beam at Fermilab. The number of observed Μτ\nu_\tau CC interactions is 9, from a total of 578 observed neutrino interactions. We calculated the energy-independent part of the tau-neutrino CC cross section (Îœ+Μˉ\nu + \bar \nu), relative to the well-known Îœe\nu_e and ΜΌ\nu_\mu cross sections. The ratio σ(Μτ)\sigma(\nu_\tau)/σ(Îœe,ÎŒ)\sigma(\nu_{e,\mu}) was found to be 1.37±0.35±0.771.37\pm0.35\pm0.77. The Μτ\nu_\tau CC cross section was found to be 0.72±0.24±0.36×10−380.72 \pm 0.24\pm0.36 \times 10^{-38} cm2GeV−1^{2}\rm{GeV}^{-1}. Both results are in agreement the Standard Model.Comment: 37 pages, 15 figure

    Enhancing optimization capabilities using the AGILE collaborative MDO framework with application to wing and nacelle design

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    This paper presents methodological investigations performed in research activities in the field of Multi-disciplinary Design and Optimization (MDO) for overall aircraft design in the EU funded research project AGILE (2015–2018). In the AGILE project a team of 19 industrial, research and academic partners from Europe, Canada and Russia are working together to develop the next generation of MDO environment that targets significant reductions in aircraft development costs and time to market, leading to cheaper and greener aircraft. The paper introduces the AGILE project structure and describes the achievements of the 1st year that led to a reference distributed MDO system. A focus is then made on different novel optimization techniques studied during the 2nd year, all aiming at easing the optimization of complex workflows that are characterized by a high number of discipline interdependencies and a large number of design variables in the context of multi-level processes and multi-partner collaborative engineering projects. Three optimization strategies are introduced and validated for a conventional aircraft. First, a multi-objective technique based on Nash Games and Genetic Algorithm is used on a wing design problem. Then a zoom is made on the nacelle design where a surrogate-based optimizer is used to solve a mono-objective problem. Finally a robust approach is adopted to study the effects of uncertainty in parameters on the nacelle design process. These new capabilities have been integrated in the AGILE collaborative framework that in the future will be used to study and optimize novel unconventional aircraft configurations

    3D rainbow phononic crystals for extended vibration attenuation bands

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    We hereby report for the first time on the design, manufacturing and testing of a three-dimensional (3D) nearly-periodic, locally resonant phononic crystal (PnC). Most of the research effort on PnCs and metamaterials has been focused on the enhanced dynamic properties arising from their periodic design. Lately, additive manufacturing techniques have made a number of designs with intrinsically complex geometries feasible to produce. These recent developments have led to innovative solutions for broadband vibration attenuation, with a multitude of potential engineering applications. The recently introduced concept of rainbow metamaterials and PnCs has shown a significant potential for further expanding the spectrum of vibration attenuation in such structures by introducing a gradient profile for the considered unit cells. Given the above, it is expected that designing non-periodic PnCs will attract significant attention from scientists and engineers in the years to come. The proposed nearly-periodic design is based on cuboid blocks connected by curved beams, with internal voids in the blocks being implemented to adjust the local masses and generate a 3D rainbow PnC. Results show that the proposed approach can produce lightweight PnCs of a simple, manufacturable design exhibiting attenuation bandwidths more than two times larger than the equivalent periodic designs of equal mass
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