2,618 research outputs found

    In-Beam Background Suppression Shield

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    The long (3ms) proton pulse of the European Spallation Source (ESS) gives rise to unique and potentially high backgrounds for the instrument suite. In such a source an instrument capabilities will be limited by it's Signal to Noise (S/N) ratio. The instruments with a direct view of the moderator, which do not use a bender to help mitigate the fast neutron background, are the most challenging. For these beam lines we propose the innovative shielding of placing blocks of material directly into the guide system, which allow a minimum attenuation of the cold and thermal fluxes relative to the background suppression. This shielding configuration has been worked into a beam line model using Geant4. We study particularly the advantages of single crystal sapphire and silicon blocks .Comment: 12 pages, 8 figures, proceeding of NDS 2015, 4th International Workshop on Neutron Delivery Systems, 28 -30 September 2015, ILL Grenoble, Franc

    Threading the spindle: a geometric study of chiral liquid crystal polymer microparticles

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    Polymeric particles are strong candidates for designing artificial materials capable of emulating the complex twisting-based functionality observed in biological systems. In this letter, we provide the first detailed investigation of the swelling behavior of bipolar polymer liquid crystalline microparticles. Deswelling from the spherical bipolar configuration causes the microparticle to contract anisotropically and twist in the process, resulting in a twisted spindle shaped structure. We propose a model to describe the observed spiral patterns and twisting behavior

    Facility for fast neutron irradiation tests of electronics at the ISIS spallation neutron source

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    The VESUVIO beam line at the ISIS spallation neutron source was set up for neutron irradiation tests in the neutron energy range above 10 MeV. The neutron flux and energy spectrum were shown, in benchmark activation measurements, to provide a neutron spectrum similar to the ambient one at sea level, but with an enhancement in intensity of a factor of 107. Such conditions are suitable for accelerated testing of electronic components, as was demonstrated here by measurements of soft error rates in recent technology field programable gate arrays

    Swimming in the Antarctic scallop Adamussium colbecki

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    Management of Devastating Ocular Trauma--Experience of Maxillofacial Surgeons Deployed to a Forward Field Hospital

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    Combat-related eye injuries continue to increase in frequency and are generally secondary to Improvised Explosive Devices. Many ocular injuries are potentially preventable by the wearing of ballistic eye protection. The management of penetrating eye trauma is normally outside the routine practice of maxillofacial surgeons in the UK. The aim of this paper is to describe the surgical techniques used in the modern management of devastating ocular trauma including selected case examples managed by British military maxillofacial surgeons deployed to Afghanistan
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