84 research outputs found

    Velocity-space sensitivity of the time-of-flight neutron spectrometer at JET

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    The velocity-space sensitivities of fast-ion diagnostics are often described by so-called weight functions. Recently, we formulated weight functions showing the velocity-space sensitivity of the often dominant beam-target part of neutron energy spectra. These weight functions for neutron emission spectrometry (NES) are independent of the particular NES diagnostic. Here we apply these NES weight functions to the time-of-flight spectrometer TOFOR at JET. By taking the instrumental response function of TOFOR into account, we calculate time-of-flight NES weight functions that enable us to directly determine the velocity-space sensitivity of a given part of a measured time-of-flight spectrum from TOFOR

    Relationship of edge localized mode burst times with divertor flux loop signal phase in JET

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    A phase relationship is identified between sequential edge localized modes (ELMs) occurrence times in a set of H-mode tokamak plasmas to the voltage measured in full flux azimuthal loops in the divertor region. We focus on plasmas in the Joint European Torus where a steady H-mode is sustained over several seconds, during which ELMs are observed in the Be II emission at the divertor. The ELMs analysed arise from intrinsic ELMing, in that there is no deliberate intent to control the ELMing process by external means. We use ELM timings derived from the Be II signal to perform direct time domain analysis of the full flux loop VLD2 and VLD3 signals, which provide a high cadence global measurement proportional to the voltage induced by changes in poloidal magnetic flux. Specifically, we examine how the time interval between pairs of successive ELMs is linked to the time-evolving phase of the full flux loop signals. Each ELM produces a clear early pulse in the full flux loop signals, whose peak time is used to condition our analysis. The arrival time of the following ELM, relative to this pulse, is found to fall into one of two categories: (i) prompt ELMs, which are directly paced by the initial response seen in the flux loop signals; and (ii) all other ELMs, which occur after the initial response of the full flux loop signals has decayed in amplitude. The times at which ELMs in category (ii) occur, relative to the first ELM of the pair, are clustered at times when the instantaneous phase of the full flux loop signal is close to its value at the time of the first ELM

    Using mobile devices to help high school students improve their oral presentation skills

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    Video review is a useful tool for formative assessment in higher education settings. However, not much is known about the impact of video review as a tool for bringing about better student outcomes in oral presentation in a school setting. This paper examines the effectiveness of using video review in student learning of English oral presentations in both in-class and out-of-class settings for Grade 11 Research Education students in a Singapore high school. Three conditions were: (a) in-class video review (n = 21), (b) out-of-class video review using mobile devices (n= 18), and (c) no video review (n = 19). We used both parametric and non-parametric analyses to determine whether inclass video review and out-of-class video review had an impact on student outcomes in terms of (a) fluency and clarity of speech, (b) audience awareness, (c) response to questions, and (d) effectiveness of group presentation. The findings indicate that having in-class video review of students’ presentations in English results in significantly higher scores for effectiveness of group presentation

    The moral rhetoric of childhood

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    In the UK, the discourse of innocence currently prevails as a major way of understanding children. This article argues that the strength of this discourse lies in its prevalence, its resistance to challenges and the ways in which it connects ideas of innocence and vulnerability. The moral quality of the discourse of innocence works in conjunction with the sacred status of the child, to produce childhood as a moral rhetoric. Children and childhood function to explain and legitimize any practice or opinion as right while removing the necessity to provide reasons: children are the reason. The article also considers how issues around childhood and morality are implicated in the generation of social concern with risks affecting children
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