3,065 research outputs found

    Orbiter windward surface entry Heating: Post-orbital flight test program update

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    Correlations of orbiter windward surface entry heating data from the first five flights are presented with emphasis on boundary layer transition and the effects of catalytic recombination. Results show that a single roughness boundary layer transition correlation developed for spherical element trips works well for the orbiter tile system. Also, an engineering approach for predicting heating in nonequilibrium flow conditions shows good agreement with the flight test data in the time period of significant heating. The results of these correlations, when used to predict orbiter heating for a high cross mission, indicate that the thermal protection system on the windward surface will perform successfully in such a mission

    Single-qubit unitary gates by graph scattering

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    We consider the effects of plane-wave states scattering off finite graphs, as an approach to implementing single-qubit unitary operations within the continuous-time quantum walk framework of universal quantum computation. Four semi-infinite tails are attached at arbitrary points of a given graph, representing the input and output registers of a single qubit. For a range of momentum eigenstates, we enumerate all of the graphs with up to n=9n=9 vertices for which the scattering implements a single-qubit gate. As nn increases, the number of new unitary operations increases exponentially, and for n>6n>6 the majority correspond to rotations about axes distributed roughly uniformly across the Bloch sphere. Rotations by both rational and irrational multiples of π\pi are found.Comment: 8 pages, 7 figure

    Colheita e armazenamento de sementes de coentro.

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    Made available in DSpace on 2011-04-09T16:13:50Z (GMT). No. of bitstreams: 1 nascimentocolheita.pdf: 1775148 bytes, checksum: 55e9ecfa2f8f7b5b443ff8e6687a2648 (MD5) Previous issue date: 2007-03-2

    Course-based Science Research Promotes Learning in Diverse Students at Diverse Institutions

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    Course-based research experiences (CREs) are powerful strategies for spreading learning and improving persistence for all students, both science majors and nonscience majors. Here we address the crucial components of CREs (context, discovery, ownership, iteration, communication, presentation) found across a broad range of such courses at a variety of academic institutions. We also address how the design of a CRE should vary according to the background of student participants; no single CRE format is perfect. We provide a framework for implementing CREs across multiple institutional types and several disciplines throughout the typical four years of undergraduate work, designed to a variety of student backgrounds. Our experiences implementing CREs also provide guidance on overcoming barriers to their implementation

    Redefining smoking relapse as recovered social identity – secondary qualitative analysis of relapse narratives

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    Although many people in the general population manage to quit smoking, relapse is common. Theory underpinning the determinants of smoking relapse is under-developed. This article aims to specify theoretical insight into the process of relapse to smoking, to underpin effective intervention development. Secondary qualitative analysis of extended narratives of smoking relapse (n=23) were inductively coded within our conceptual framework of a socially situated narrative theoretical approach to identity. Smoking relapse is conceptualised as a situated rational response to a ‘disruption’ in individual narrative identity formation, and an attempt to recover a lost social identity. Emotional reactions to relapse, such as pleasure, but also guilt and shame, support this assertion by demonstrating the ambivalence of re-engaging in a behaviour that is situated and rational in terms of individual identity formation, yet ostracised and stigmatised by wider culture

    Broadcasting graphic war violence: the moral face of Channel 4

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    Drawing on empirical data from Channel 4 (C4) regarding the broadcasting of violent war imagery, and positioned within Goffman’s notion of the interaction ritual (1959, 1967), this article investigates how C4 negotiate potentially competing commercial, regulatory and moral requirements through processes of discretionary decision-making. Throughout, the article considers the extent to which these negotiations are presented through a series of ‘imaginings’ – of C4 and its audience – which serve to simultaneously guide and legitimate the decisions made. This manifestation of imaginings moves us beyond more blanket explanations of ‘branding’ and instead allows us to see the final programmes as the end product of a series of complex negotiations and interactions between C4 and those multiple external parties significant to the workings of their organization. The insights gleaned from this case study are important beyond the workings of C4 because they help elucidate how all institutions and organizations may view, organize and justify their practices (to both themselves and others) within the perceived constraints in which they operate

    The Self stepping into the shoes of the Other: Understanding and developing self-perceptions of empathy among prospective physical education teachers through a special school placement

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    Teachers who demonstrate a high degree of empathy are said to have more positive attitudes towards pupils with disabilities. Therefore, this article sought to explore the influence of a special school placement on prospective teachers’ self-perceptions of empathy. Thirty-two final year undergraduate students participated in focus group interviews and were selected because they aspired to be a physical education teacher and had attended a placement in a special school. Interview transcripts were analysed and the following themes constructed: Stepping into the shoes of the Other; Frustrated ‘for’ not ‘with’ pupils with disabilities; Empathy for planning inclusive lessons and ‘reading’ pupil body language; and Knowing when not to show empathy. All prospective teachers felt that: (a) they could empathise with pupils with disabilities; (b) situated learning experiences within the placement enabled them to reflect on the ways in which their empathy influences their teaching now and could continue to do so in the future; and (c) it was important that teachers demonstrated empathy. Thus, it is recommended that all prospective teachers gain some experience teaching in special schools. Our research also warns against teachers claiming the last, conclusive word about who children with disabilities are, what they think, how they feel and what they want, in myriad contexts and situations

    The purpose of mess in action research: building rigour though a messy turn

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    Mess and rigour might appear to be strange bedfellows. This paper argues that the purpose of mess is to facilitate a turn towards new constructions of knowing that lead to transformation in practice (an action turn). Engaging in action research - research that can disturb both individual and communally held notions of knowledge for practice - will be messy. Investigations into the 'messy area', the interface between the known and the nearly known, between knowledge in use and tacit knowledge as yet to be useful, reveal the 'messy area' as a vital element for seeing, disrupting, analysing, learning, knowing and changing. It is the place where long-held views shaped by professional knowledge, practical judgement, experience and intuition are seen through other lenses. It is here that reframing takes place and new knowing, which has both theoretical and practical significance, arises: a 'messy turn' takes place
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