16,625 research outputs found

    Time Dilation and Quasar Variability

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    The timescale of quasar variability is widely expected to show the effects of time dilation. In this paper we analyse the Fourier power spectra of a large sample of quasar light curves to look for such an effect. We find that the timescale of quasar variation does not increase with redshift as required by time dilation. Possible explanations of this result all conflict with widely held consensus in the scientific community.Comment: 6 pages including 3 figures. Accepted for publication in ApJ Letter

    Cost analysis of new and retrofit hot-air type solar assisted heating systems

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    A detailed cost analysis/cost improvement study was performed on two Department of Energy/National Aeronautics and Space Administration operational test sites to determine actual costs and potential cost improvements of new and retrofit hot air type, solar assisted heating and hot water systems for single family sized structures. This analysis concentrated on the first cost of a system which included procurement, installation, and integration of a solar assisted heating and hot water system on a new or retrofit basis; it also provided several cost projections which can be used as inputs to payback analyses, depending upon the degree of optimism or future improvements assumed. Cost definitions were developed for five categories of cost, and preliminary estimates were developed for each. The costing methodology, approach, and results together with several candidate low cost designs are described

    A spectrum of ozone from 760 to 5800 cm-1

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    An atlas of O3 lines between 760 and 5800/cm obtained from a low pressure, long-path-length sample of O3 at 296K is presented. Many of the line centers are marked and their positions tabulated

    Rational combinations of Betti diagrams of complete intersections

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    We investigate decompositions of Betti diagrams over a polynomial ring within the framework of Boij-S\"oderberg theory. That is, given a Betti diagram, we determine if it is possible to decompose it into the Betti diagrams of complete intersections. To do so, we determine the extremal rays of the cone generated by the diagrams of complete intersections and provide a rudimentary algorithm for decomposition.Comment: This research was conducted at the Willamette Mathematics Consortium RE

    Inlet spillage drag tests and numerical flow-field analysis at subsonic and transonic speeds of a 1/8-scale, two-dimensional, external-compression, variable-geometry, supersonic inlet configuration

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    Accurate spillage drag and pressure data are presented for a realistic supersonic inlet configuration. Results are compared with predictions from a finite-differencing, inviscid analysis computer procedure. The analytical technique shows good promise for the evaluation of inlet drag, but necessary refinements were identified. A detailed description of the analytical procedure is contained in the Appendix

    Embedding stakeholders in sustainable tourism strategies

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    This research explains how the involvement of stakeholders in sustainable tourism (ST) strategies can be enhanced. The study was inspired by the persistent failure of ST proponents to recognise the significance of stakeholder management processes in the implementation of ST strategies. The ‘Traffic Light Routes’ framework is proposed with the Green Route forming the most desirable strategy for adoption by managers, and the Amber Route and the Red Route completing the construct. The ‘Traffic Light Routes’ emerged from a study of an award-winning ST initiative in the South West of the United Kingdom encompassing focus group research and interviews with a cross section of stakeholders. In recognition of the global significance of sustainable development, the ‘Traffic Light Routes’ framework contributes towards the bigger picture of ST realisation

    Implementing sustainable tourism: a multi-stakeholder involvement management framework

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    Within the extensive body of literature on sustainable tourism (ST), its successful implementation is an emerging and important theme. The lack of or ineffective stakeholder participation is a major obstacle to ST realisation and there is little clarity as to how best to resolve this problem. This paper presents the findings of a purposive UK-based case study that evaluated stakeholder involvement in the implementation of ST. Using over fifty stakeholders’ accounts drawn from eight primary stakeholder groups, a ‘multi-stakeholder involvement management’ (MSIM) framework was developed. The MSIM framework consists of three strategic levels: attraction, integration and management of stakeholder involvement. Six stages are embedded within the three levels: scene-setting, recognition of stakeholder involvement capacity, stakeholder relationship management, pursuit of achievable objectives, influencing implementation capacity and monitoring stakeholder involvement. These are supported by the overarching notion of ‘hand-holding’ and key actions [e.g. managing stakeholder adaptability] that enhance stakeholder involvement in ST. Key words: Implementation, Sustainable Tourism, Stakeholder Involvement, Stakeholder framewor

    The 'leadership-stakeholder involvement capacity' nexus in stakeholder management

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    It is accepted that stakeholders affect the achievement of organisational plans and that ineffective ‘stakeholder involvement’ in developmental initiatives can hinder the achievement of business objectives. Purposive case study research using the context of sustainability demonstrated that ‘stakeholder involvement’ (how stakeholders become active or inactive) is a complex process influenced by a range of interlinked internally and externally driven factors. Principally, the process is influenced by the type of leadership (leadership quality) and the capability of stakeholders to become involved (stakeholder involvement capacity). These two forces play a significant role in stakeholder involvement and constitute the main part of the ‘Leadership-Stakeholder Involvement Capacity’ (LSIC) nexus that is presented in this paper
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