8,920 research outputs found

    Reliability analysis of semi-automatic train door systems in service on today's rolling stock of the SNCB

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    This article analyses the reliability of semi-automatic train door systems that are in use on today’s rolling stock of the SNCB. For the analysis several databases of the SNCB concerning both operation and maintenance were thoroughly screened. These databases are briefly explained and scaling factors are applied to compare the performance of different series of rolling stock relative to each other. Conclusions are made out of the available data

    Radio AGN in 13,240 galaxy clusters from the Sloan Digital Sky Survey

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    We correlate the positions of 13,240 Brightest Cluster Galaxies (BCGs) with 0.1 <= z <= 0.3 from the maxBCG catalog with radio sources from the FIRST survey to study the sizes and distributions of radio AGN in galaxy clusters. We find that 19.7% of our BCGs are associated with FIRST sources, and this fraction depends on the stellar mass of the BCG, and to a lesser extent on the richness of the parent cluster (in the sense of increasing radio loudness with increasing mass). The intrinsic size of the radio emission associated with the BCGs peaks at 55 kpc, with a tail extending to 200 kpc. The radio power of the extended sources places them on the divide between FR I and FR II type sources, while sources compact in the radio tend to be somewhat less radio-luminous. We also detect an excess of radio sources associated with the cluster, instead of with the BCG itself, extending out to ~1.4 Mpc.Comment: 14 pages, 6 figures, accepted for publication in ApJ

    Investigating correlation of faecal indicator bacteria and potential pathogenic fungi on Dublin beaches in the interest of public health

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    Sandy beaches are usually the preferred location for leisure activities but may pose a risk to public health in particular to children, the elderly and immuno compromised individuals Beach sand and marine water may be a reservoir of opportunistic and pathogenic microbes, as well as faecal indicator bacteria (that influence the bathing water quality status. The growth and the proliferation of microbes in beach sand and water are not restricted to bacteria but include also different groups of fungi such as potentially pathogenic and allergenic moulds, yeasts and dermatophytes Currently, no clear guidance about pathogenic fungi levels in relation to public health is available for these environments.info:eu-repo/semantics/publishedVersio

    Tight Noise Thresholds for Quantum Computation with Perfect Stabilizer Operations

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    We study how much noise can be tolerated by a universal gate set before it loses its quantum-computational power. Specifically we look at circuits with perfect stabilizer operations in addition to imperfect non-stabilizer gates. We prove that for all unitary single-qubit gates there exists a tight depolarizing noise threshold that determines whether the gate enables universal quantum computation or if the gate can be simulated by a mixture of Clifford gates. This exact threshold is determined by the Clifford polytope spanned by the 24 single-qubit Clifford gates. The result is in contrast to the situation wherein non-stabilizer qubit states are used; the thresholds in that case are not currently known to be tight.Comment: 4 pages, 2 figure
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