Sensitivity Coefficients for Fast Reactor Core Analysis

Sensitivity coefficients of nuclear reactors with respect to cross section changes are very useful for the evaluation of neutronic characteristics with respect to nuclear data change, cross section adjustment, and uncertainty analysis. In the analysis of fast reactors, cell calculations are usually carried out using fine energy groups to accurately take into account the cross section behaviour in the fast and resonance energy ranges. Sensitivity coefficients should thus be calculated using fine groups, although in practice core calculations are done with broad energy groups. Also, in fast reactors the transport effect is large because of the long neutron mean free path and because leakage is larger than in thermal reactors. However, sensitivity coefficients are usually calculated based on diffusion theory. This paper present two topics. The first is a “sensitivity reconstruction", an attempt to estimate fine group sensitivities from broad group calculations. A “flux reconstruction" method is proposed, and the results from some sample calculations are presented. The second topic is the transport effect on the sensitivity coefficients. Sensitivity coefficients are calculated using transport and diffusion theory. It is shown that for reactors of the size of Monju (714 MWth) the results from transport and diffusion calculations are in reasonable agreement.7-11 December 2009 Kyoto, Japanconference pape

Superior DC and RF Performance of AlGaN-Channel HEMT at High Temperatures

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Exploring the factor on sensory motor function of upper limb associated with executive function in community-dwelling older adults

2016-08Exercise, such as cardiovascular fitness training, has been shown to have utility in improving executive function but is difficult for older adults with low mobility to perform. Accordingly, there is interest in the development of regimens other than high mobility exercises for older adults with low mobility. The aim of the present study was to evaluate the association between sensory motor function of the upper limb and executive function in community-dwelling older adults. A cross-sectional study was conducted in 57 right-handed, independent, community-dwelling older adults. Sensory motor function of upper limb, including range of motion, strength, sensation, finger dexterity, and comprehensive hand function was measured in both hands. Executive function was assessed using the Delta Trail Making Test. Multiple regression analysis indicated the finger dexterity of the non-dominant hand as independently associated with executive function (β = –0.414, P < 0.001). The findings of the present study may facilitate the development of exercise regimens for improving executive function that are more suitable for older adults with limited physical fitness levels. As this was a cross-sectional study, further studies are required to validate the efficacy of non-dominant finger dexterity training for improving executive function in older adults.departmental bulletin pape

少年スポーツ活動における継続性に及ぼす要因に関する研究

Articledepartmental bulletin pape