9 research outputs found

    Electromagnetic Compatibility of a Low Voltage Power Supply for the ATLAS Tile Calorimeter Front-End Electronics

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    The front-end electronics of the ATLAS Tile Calorimeter is powered by DC/DC converters that sit close to it. The performance of the detector electronics is constrained by the conducted noise emissions of its power supply. A compatibility limit is defined for the system. The noise susceptibility of the front-end electronics is evaluated, and different solutions to reduce the front-end electronics noise are discussed and tested

    Validity of self- reported sedentary time differs between Australian rural men engaged in office and farming occupations

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    Rural Australians have a higher likelihood of chronic disease than urban Australians, particularly male farmers. Chronic disease has been associated with occupational sedentary time. The aim was to validate the self-report of sedentary time in men in contrasting rural occupations. Farmers (n = 29) and office workers (n = 28), age 30–65 years, were recruited from the Riverland region of South Australia. Daily sedentary time and number of breaks in sedentary time were self-reported and measured objectively using body-worn inclinometers. Correlational analyses were conducted between self-reported and objectively measured variables, separately by occupation. There was a significant correlation between self-reported and objectively measured sedentary time in the whole sample (r = 0.44, P = 0.001). The correlation among office workers was significant (r = 0.57, P = 0.003) but not among farmers (r = 0.08, P = 0.68). There were no significant correlations between self-reported and measured number of breaks in sedentary time, for the whole sample (rho = −0.03, P = 0.83), office workers (rho = 0.17, P = 0.39) and farmers (rho = −0.22, P = 0.25). In conclusion, the validity of self-report of sedentary behaviours by farmers was poor. Further research is needed to develop better performing self-report instruments or more accessible objective measures of sedentary behaviour in this population

    Optimization of DC-DC Converters for Improved Electromagnetic Compatibility With High Energy Physics Front-End Electronics

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    The upgrade of the Large Hadron Collider (LHC) experiments at CERN sets new challenges for the powering of the detectors. One of the powering schemes under study is based on DC-DC buck converters mounted on the front-end modules. The hard environmental conditions impose strict restrictions to the converters in terms of low volume, radiation and magnetic field tolerance. Furthermore, the noise emission of the switching converters must not affect the performance of the powered systems. A study of the sources and paths of noise of a synchronous buck converter has been made for identifying the critical parameters to reduce their emissions. As proof of principle, a converter was designed following the PCB layout considerations proposed and then used for powering a silicon strip module prototype for the ATLAS upgrade, in order to evaluate their compatibility
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