932 research outputs found

    The core structure of presolar graphite onions

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    Of the ``presolar particles'' extracted from carbonaceous chondrite dissolution residues, i.e. of those particles which show isotopic evidence of solidification in the neighborhood of other stars prior to the origin of our solar system, one subset has an interesting concentric graphite-rim/graphene-core structure. We show here that single graphene sheet defects in the onion cores (e.g. cyclopentane loops) may be observable edge-on by HREM. This could allow a closer look at models for their formation, and in particular strengthen the possibility that growth of these assemblages proceeds atom-by-atom with the aid of such in-plane defects, under conditions of growth (e.g. radiation fluxes or grain temperature) which discourage the graphite layering that dominates subsequent formation of the rim.Comment: 4 pages, 7 figures, 11 refs, see also http://www.umsl.edu/~fraundor/isocore.htm

    The United Kingdom smart meter rollout through an energy justice lens

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    The United Kingdom’s Smart Meter Implementation Programme (SMIP) creates the legal framework so that an in-home display unit and a smart gas and electricity meter can be installed in every household by the end of 2020. Intended to reduce household energy consumption, the SMIP is one of the world’s most complex smart meter rollouts. It is also proving to be a challenging one as a series of obstacles has characterised and potentially restricted implementation. This chapter first gives background to the most recent smart meter roll out developments in the UK and second, uses an energy justice framework to explore the emergent challenges under the titles of distributional justice, procedural justice and justice as recognition. Applying this framework to an analysis of the UK SMIP provides opportunities to accurately record, present and expose potential forthcoming injustices. In light of this, we offer a series of policy recommendations

    The UK market for energy service contracts in 2014–2015

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    This paper provides an overview of the UK market for energy service contracts in 2014 and highlights the growing role of intermediaries. Using information from secondary literature and interviews, it identifies the businesses offering energy service contracts, the sectors and organisations that are purchasing those contracts, the types of contract that are available, the areas of market growth and the reasons for that growth. The paper finds that the UK market is relatively large, highly diverse, concentrated in particular sectors and types of site and overwhelmingly focused upon established technologies with high rates of return. A major driver is the emergence of procurement frameworks for energy service contracts in the public sector. These act as intermediaries between clients and contractors, thereby lowering transaction costs and facilitating learning. The market is struggling to become established in commercial offices, largely as a result of split incentives, and is unlikely to develop further in this sector without different business models, tenancy arrangements and policy initiatives. Overall, the paper concludes that energy service contracts can play an important role in the transition to a low-carbon economy, especially when supported by intermediaries, but their potential is still limited by high transaction costs

    Chirality of wave functions for three coalescing levels

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    The coalescence of three levels has particular attractive features. Even though it may be difficult to realise such event in the laboratory (three additional real parameters must be adjusted), to take up the challenge seems worthwhile. In the same way as the chiral behaviour of a usual EP can give a direction on a line, the state vectors in the vicinity of an EP3 provide an orientation in the plane. The distinction between left and right handedness depends on the distribution of the widths of the three levels in the vicinity of the point of coalescence.Comment: Manuscript has been discussed in June 2007 with the experimental group under Professor Achim Richter at the TU Darmstadt. It has been presented at the 6th International Workshop on Pseudo Hermitian Hamiltonians, London, 16-18 July 2007. An expanded version is being prepared for publication. 3 Figures, 11 page

    Fast readout algorithm for cylindrical beam position monitors providing good accuracy for particle bunches with large offsets

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    A simple, analytically correct algorithm is developed for calculating pencil beam coordinates using the signals from an ideal cylindrical particle beam position monitor (BPM) with four pickup electrodes (PUEs) of infinitesimal widths. The algorithm is then applied to simulations of realistic BPMs with finite width PUEs. Surprisingly small deviations are found. Simple empirically determined correction terms reduce the deviations even further. The algorithm is then used to study the impact of beam-size upon the precision of BPMs in the non-linear region. As an example of the data acquisition speed advantage, a FPGA-based BPM readout implementation of the new algorithm has been developed and characterized. Finally,the algorithm is tested with BPM data from the Cornell Preinjector.Comment: 21 pages, 17 figure

    Relaxation rate of the reverse biased asymmetric exclusion process

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    We compute the exact relaxation rate of the partially asymmetric exclusion process with open boundaries, with boundary rates opposing the preferred direction of flow in the bulk. This reverse bias introduces a length scale in the system, at which we find a crossover between exponential and algebraic relaxation on the coexistence line. Our results follow from a careful analysis of the Bethe ansatz root structure.Comment: 22 pages, 12 figure

    Mining Public Domain Data to Develop Selective DYRK1A Inhibitors

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    Kinases represent one of the most intensively pursued groups of targets in modern-day drug discovery. Often it is desirable to achieve selective inhibition of the kinase of interest over the remaining ∟500 kinases in the human kinome. This is especially true when inhibitors are intended to be used to study the biology of the target of interest. We present a pipeline of open-source software that analyzes public domain data to repurpose compounds that have been used in previous kinase inhibitor development projects. We define the dual-specificity tyrosine-regulated kinase 1A (DYRK1A) as the kinase of interest, and by addition of a single methyl group to the chosen starting point we remove glycogen synthase kinase β (GSK3β) and cyclin-dependent kinase (CDK) inhibition. Thus, in an efficient manner we repurpose a GSK3β/CDK chemotype to deliver 8b, a highly selective DYRK1A inhibitor
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