1,778 research outputs found

    Fluxes, Gaugings and Gaugino Condensates

    Full text link
    Based on the correspondence between the N = 1 superstring compactifications with fluxes and the N = 4 gauged supergravities, we study effective N = 1 four-dimensional supergravity potentials arising from fluxes and gaugino condensates in the framework of orbifold limits of (generalized) Calabi-Yau compactifications. We give examples in heterotic and type II orientifolds in which combined fluxes and condensates lead to vacua with small supersymmetry breaking scale. We clarify the respective roles of fluxes and condensates in supersymmetry breaking, and analyze the scaling properties of the gravitino mass.Comment: 17 pages, C

    Enriching the values of micro and small business research projects: co-creation service provision as perceived by academic, business and student

    Get PDF
    This is an Accepted Manuscript of an article published by Taylor & Francis in Studies in Higher Education, first published online 3 September 2014, available online: http://www.tandfonline.com/doi/full/10.1080/03075079.2014.942273.The National Committee of Inquiry into Higher Education (1996) chaired by Lord Dearing envisioned a university sector central to the UK’s knowledge-based economy. With successive government support the university-business partnership ideology has been put into practice. Widening participation has increased in emphasis over recent years, providing key innovations and skills to support business growth. Yet business schools activities in business growth is marginal against other university schools. The paper reports on an empirical study analyzing the university/business values derived from one small business engagement project. Data collected through semi-structured interviews, observations, memos, and discussions were coupled with critical evaluation of work and action-based learning (ABL) literature. Analysis reveals evidence of multiple value adding factors; it emerged that the existence of knowledge, present or generated through blended learning techniques, was a key value adding element. The findings enabled the construction of a universal process model providing a project framework, detailing areas of collaborative efforts and associated recompenses; this included ease in project advancements and a noticeably advanced project outcome. The study highlights these values in terms of individual and organizational learning, originality and quality of outputs. Given the growing importance of Small to Medium-sized Enterprises (SMEs) to the UK economy, understanding the value co-created by collaborative projects in delivering both work-based and ABL for graduates/students, academics and enterprise management is important.Peer reviewedFinal Accepted Versio

    Reflectionless tunneling in ballistic normal-metal--superconductor junctions

    Full text link
    We investigate the phenomenon of reflectionless tunneling in ballistic normal-metal--superconductor (NS) structures, using a semiclassical formalism. It is shown that applied magnetic field and superconducting phase difference both impair the constructive interference leading to this effect, but in a qualitatively different way. This is manifested both in the conductance and in the shot noise properties of the system considered. Unlike diffusive systems, the features of the conductance are sharp, and enable fine spatial control of the current, as well as single channel manipulations. We discuss the possibility of conducting experiments in ballistic semiconductor-superconductor structures with smooth interfaces and some of the phenomena, specific to such structures, that could be measured. A general criterion for the barrier at NS interfaces, though large, to be effectively transparent to pair current is obtained.Comment: published versio

    Interweaving in hybrid methodologies

    Get PDF
    The paper will consider instances of the interweaving of theory and practice within drawing research, in order to suggest potential approaches to the development of hybrid methodologies in fine art practice-led research. The paper is written from the position of two current supervisors and creative research collaborators: Deborah Harty and Phil Sawdon (aka humhyphenhum from 2007), who historically were supervisee/supervisor. The paper will make reference to Harty's experience as a Ph.D. researcher undertaking practice-led research within a fine art context (completed 2010) and supervised by Sawdon. A discussion of Harty's hybrid methodology: action theoria, will provide an instance of the interweaving of theory and practice. Action theoria incorporates the cyclical and iterative process of action research – intention; action; review – with a process of theoria – the dialogue of both practice and theory's relationship to a given subject matter. Following this, the paper will discuss the interweaving of action theoria into humhyphenhum's collaborative research methodology: meaningful play. This interwoven methodology evolved during collaborative practice-led research projects from 2005 to the present. The paper will make reference to several of humhyphenhum's projects as a means to identify the interweaving of theory and practice within collaborative research. As current supervisors (2015), the paper will conclude with a discussion of how reflection on these experiences has informed our position as supervisors. We will consider, for example, how this has impacted on our ability, as individual supervisors, to offer insights into the interweaving of theory and practice, without defaulting to the position of compelling our supervisees to adopt our methodology

    Industrial work placement in higher education: a study of civil engineering student engagement

    Get PDF
    For civil engineering undergraduates, the opportunity to spend a period of time in formal industrial work placement provides an invaluable learning experience. This paper reviews student engagement with short-term industrial placement and provides analysis of questionnaires (n=174) returned by undergraduates studying civil engineering at four Higher Education Institutes (HEI’s) in the West of Scotland. The data captures industrial placement statistics, employability skill-sets and presents brief testimonies from students. Whilst the journey to becoming a professional civil engineer is undoubtedly enhanced by short-term placement clear opportunities exist for HEI’s to affect and change existing pedagogical discourse. Commentary is likely to resonate beyond civil engineering and serve as a timely reminder of the need to re-invigorate academia / industry curriculum partnerships

    A liquid crystalline copper phthalocyanine derivative for high performance organic thin film transistors

    Get PDF
    This journal is © The Royal Society of Chemistry 2012Bottom-gate, bottom-contact organic thin film transistors (OTFTs) were fabricated using solvent soluble copper 1,4,8,11,15,18,22,25-octakis(hexyl)phthalocyanine as the active semiconductor layer. The compound was deposited as 70 nm thick spin-coated films onto gold source–drain electrodes supported on octadecyltrichlorosilane treated 250 nm thick SiO2 gate insulators. The performance of the OTFTs was optimised by investigating the effects of vacuum annealing of the films at temperatures between 50 0C and 200 0C, a range that included the thermotropic mesophase of the bulk material. These effects were monitored by ultraviolet-visible absorption spectroscopy, atomic force microscopy and XRD measurements. Device performance was shown to be dependent upon the annealing temperature due to structural changes of the film. Devices heat treated at 100 0C under vacuum (≥10-7 mbar) were found to exhibit the highest field-effect mobility, 0.7 cm2 V^-1 s^-1, with an on–off current modulation ratio of~107, a reduced threshold voltage of 2.0 V and a sub-threshold swing of 1.11 V per decade.UK Technology Strategy Board (Project no: TP/6/EPH/6/S/K2536J) and UK National Measurement System (Project IRD C02 ‘‘Plastic Electronics’’, 2008–2011)

    Type-IIA flux compactifications and N=4 gauged supergravities

    Full text link
    We establish the precise correspondence between Type-IIA flux compactifications preserving an exact or spontaneously broken N=4 supersymmetry in four dimensions, and gaugings of their effective N=4 supergravities. We exhibit the explicit map between fluxes and Bianchi identities in the higher-dimensional theory and generalized structure constants and Jacobi identities in the reduced theory, also detailing the origin of gauge groups embedded at angles in the duality group. We present AdS4 solutions of the massive Type-IIA theory with spontaneous breaking to N=1, at small string coupling and large volume, and discuss their dual CFT3.Comment: 43 pages, 1 figure. v2: refs added, v3: minor additions. Final version to appear on JHE

    The performance of GridPix detectors

    Get PDF
    A GridPix detector is a gaseous detector capable of detecting individual single primary electrons from ionizing particles. Such a detector consists of a pixel chip as active anode covered with a thin layer of silicon rich silicon nitride (SiRN) for protection against discharges, an integrated amplification grid (InGrid), applied on top of the chip by wafer post processing techniques, and a cathode plane. The drift region is between the grid and cathode while the gas gain occurs between the chip and the grid. The discharge quenching properties of the SiRN layer have been determined as well as the relation on grid capacitance, grid voltage and gas mixture. Part of the detectors in this report were of the type Gossip, a GridPix detector with a drift gap of ∼1 mm. Using such thin drift layer, one may consider this detector as a replacement for a silicon pixel detector. The performance of three Gossip detectors has been investigated by measurements in a test beam at CERN

    Managing affect in learners' questions in undergraduate science

    Get PDF
    This is the author's accepted manuscript. The final published article is available from the link below. Copyright @ 2012 Society for Research into Higher Education.This article aims to position students' classroom questioning within the literature surrounding affect and its impact on learning. The article consists of two main sections. First, the act of questioning is discussed in order to highlight how affect shapes the process of questioning, and a four-part genesis to question-asking that we call CARE is described: the construction, asking, reception and evaluation of a learner's question. This work is contextualised through studies in science education and through our work with university students in undergraduate chemistry, although conducted in the firm belief that it has more general application. The second section focuses on teaching strategies to encourage and manage learners' questions, based here upon the conviction that university students in this case learn through questioning, and that an inquiry-based environment promotes better learning than a simple ‘transmission’ setting. Seven teaching strategies developed from the authors' work are described, where university teachers ‘scaffold’ learning through supporting learners' questions, and working with these to structure and organise the content and the shape of their teaching. The article concludes with a summary of the main issues, highlighting the impact of the affective dimension of learning through questioning, and a discussion of the implications for future research
    • …
    corecore