1,985 research outputs found

    Fluxes, Gaugings and Gaugino Condensates

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    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

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    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

    Stringy NJL and Gross-Neveu models at finite density and temperature

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    Nonlocal stringy versions of the Nambu-Jona-Lasinio and Gross-Neveu models arise in a certain limit of holographic QCD. We analyze the phase structure at finite density and temperature at strong coupling in terms of probe branes in the gravity dual. Comparison with the phase structure of the local field theory models shows qualitative agreement with some aspects, and disagreement with others. Finally, we explain how to construct the Landau potentials for these models by taking the probe branes off-shell.Comment: 32 pages, uses JHEP3.cls; v2, references added, version to be submitted to JHE

    Reflectionless tunneling in ballistic normal-metal--superconductor junctions

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    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

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    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

    Survey on Traditional Mangrove Crab Identification Methods of Filipino Fishermen

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    The Philippines is one of the largest producers of mangrove crabs in the industry, but only three of the four Scylla species exist in the country. As one of the largest mangrove crab exporters, Filipino crab farmers must distinguish their harvest before catching them for crab farming since the growth and needs of crabs depend heavily on their species group. To determine the accuracy of widely used local traditional methods, survey questions were distributed to 34 respondents around the Philippines through selected online platforms. Data gathered included local methods for identifying mangrove crabs based on traditional ecological knowledge and experiences of the local fishers interviewed. The study found that 70.58% of those polled identify the species of crabs by looking at their claws and 55.88% observe the color of the crabs. Furthermore, 41.17% of respondents consider the width and size of the shell, while 11.76% examine the crabs\u27 carapace. Unique methods to certain regions were reported, including observation of minor features and behavior of the crabs and reliance on texture, weight, and season. Difficulty in species identification of juvenile crabs has been reported but was also possible when the crabs turn 2-3 months old or grow to the size of a 5-peso coin or 5 centimeters. Feeding schedules and consistent pond management are also said as crucial tasks in growing mangrove crabs. The fishermen voiced out concerns and opinions regarding the technology development and government policies in the crab industry

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

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    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

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    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)

    Double Field Theory Formulation of Heterotic Strings

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    We extend the recently constructed double field theory formulation of the low-energy theory of the closed bosonic string to the heterotic string. The action can be written in terms of a generalized metric that is a covariant tensor under O(D,D+n), where n denotes the number of gauge vectors, and n additional coordinates are introduced together with a covariant constraint that locally removes these new coordinates. For the abelian subsector, the action takes the same structural form as for the bosonic string, but based on the enlarged generalized metric, thereby featuring a global O(D,D+n) symmetry. After turning on non-abelian gauge couplings, this global symmetry is broken, but the action can still be written in a fully O(D,D+n) covariant fashion, in analogy to similar constructions in gauged supergravities.Comment: 28 pages, v2: minor changes, version published in JHE
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