16,249 research outputs found

    Pulsed Doppler lidar for the detection of turbulence in clear air

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    A pulsed C02 Doppler lidar system is described and demonstration tests in ground-based and airborne flight operations are discussed. As a ground-based system, it can detect wind shears in thunderstorm gust fronts to a range of 6 km. When in the airborne configuration, the lidar can detect clear air turbulence in advance of the aircraft encountering clear air turbulence. The data provided by the lidar included turbulence location and intensity with intensity being indicated by the measured spectral width which is proportional to the wind gust velocity

    Controls on geothermal heat recovery from a hot sedimentary aquifer in Guardbridge, Scotland:Field measurements, modelling and long term sustainability

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    Geothermal heat from Hot Sedimentary Aquifers represents a promising intermediate (30Ā°C) resource for district heating systems. A key control on the geothermal productivity of these aquifers is the architecture of faults, which can significantly enhance or reduce the natural permeability of these systems. We present the first three-dimensional coupled groundwater flow and heat transport numerical model, combining multiple data from field mapping and fracture surveys, of two intersecting major fault systems in Central-East Scotland. This includes fault-zone fracture permeability modelling, depth-dependent permeability modelling, geo-mechanical facies assessment and heat productivity estimates for single well and multiple well extraction scenarios. Simulations indicate that with careful location of extraction wells within permeable fault systems, production is sustainable for over 50 years for multiple-well extraction scenarios in this region

    ā€˜So presumably things have moved on since then?ā€™ The management of risk allegations in child contact mediation.

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    Author's draft version. Copyright Ā© Oxford University Press. Final version available online at http://www.oxfordjournals.org/Over the past decade, considerable efforts have been made to ensure that domestic violence and child protection issues are identifi ed, assessed, and managed appropriately within the family justice system. These efforts follow sustained criticism that allegations of harm have been previously overlooked or marginalized within court processes, including in private law cases concerning residence and contact disputes following parental separation. In this article, however, we argue that allegations of harm continue to be marginalised in court-based dispute resolution. Our fi ndings are based on a detailed study of 15 in-court conciliation or court-based dispute resolution sessions. We use conversation analysis to examine in detail precisely how allegations are overlooked or downgraded. We fi nd that conciliators routinely ignore, reframe, or reject allegations unless there is an existing external evidence to support the claim. However, the precise way in which marginalisation occurs is contextual and interactional, shaped not least by the specifi city or persistence of allegations presented by parents. We suggest that the conciliatorā€™s handling of allegations refl ects a particular understanding of their institutional role and tasks that centre upon settlement, contact, and case processing seemingly at the expense of risk management.Data originally collected as part of a Lord Chancellorā€™s Department funded project. The analysis of the data was supported by Economic and Social Research Council grant RES-000-22-264

    The source of Dalradian detritus in the Buchan Block, NE Scotland: Application of new tools to detrital datasets

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    Detrital zircons from four samples of upper Dalradian metasedimentary rocks from the Buchan Block in the NE Grampian Highlands of Scotland were analysed by laser ablation inductively coupled plasma mass spectrometry to establish their Uā€“Pb age and trace element composition. The analysed grains (magmatic cores) mainly yield concordant ages ranging from Neoproterozoic to Eoarchaean. Kernel density plots of the data show pronounced peaks in the late Mesoproterozoic, Palaeoproterozoic and Neoarchaean eras. The data are indistinguishable from detrital zircon age spectra from Dalradian rocks elsewhere, an interpretation supported by application of a non-parametric multidimensional scaling algorithm, and are consistent with a Laurentian source. Similar to existing studies from other Dalradian rocks, the age spectra from the Buchan Block reveal an increase in the relative proportion of older detritus with time, suggesting derivation from late Mesoproterozoic (Grenville) then Palaeoproterozoic orogens before widespread exposure and denudation of their Archaean basement rocks. Application of a novel approach to estimate the most likely time of radiogenic-Pb loss indicates that some detrital zircon grains were affected by element mobility around 470ā€“450 Ma as a result of Grampian orogenesis

    Does endoscopic sinus surgery alter the biomechanics of the orbit?

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    Ā© 2020 The Author(s). Objective: The purpose of this study is to determine if removal of ethmoid cell septations as commonly performed in endoscopic sinus surgery leads to a change in orbital wall fracture patterns and the force required to create them. Methods: Six fresh-frozen cadaveric heads were acquired and underwent endoscopic uncinectomy, maxillary antrostomy, and anterior and posterior ethmoidectomy on one, randomized, side. The contralateral sinuses were used as intra-specimen control. Hyaluronic acid gel globe injections were performed to simulate normal intra-ocular pressure. Post-op CT scans confirmed no orbital fractures or violation of the lamina papyracea prior to trauma testing. Orbital trauma was induced using a guided weight-drop technique. Both orbits were tested in random order, and sequentially higher drops were performed until both the test and control side demonstrated an orbital fracture on CT scan. Results: In all six heads, the post-sinus surgery side incurred a medial orbital wall fracture, and no orbital floor fractures were identified. On the other hand, on the control side, all six heads incurred orbital floor fractures at drop heights equal to, or higher than, the surgical side. Fisher\u27s exact test demonstrated a significant difference in fracture pattern (p \u3c 0.001). Conclusions: To our knowledge, this is the first demonstration that the structures removed during sinus surgery may act as a buttress for the medial orbital wall. The anatomic changes of sinus surgery may alter the biomechanics of the orbit and affect the pattern of subsequent traumatic blowout fractures

    Effect of neutrophil depletion on gelatinase expression, edema formation and hemorrhagic transformation after focal ischemic stroke

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    BACKGROUND: While gelatinase (MMP-2 and -9) activity is increased after focal ischemia/reperfusion injury in the brain, the relative contribution of neutrophils to the MMP activity and to the development of hemorrhagic transformation remains unknown. RESULTS: Anti-PMN treatment caused successful depletion of neutrophils in treated animals. There was no difference in either infarct volume or hemorrhage between control and PMN depleted animals. While there were significant increases in gelatinase (MMP-2 and MMP-9) expression and activity and edema formation associated with ischemia, neutrophil depletion failed to cause any change. CONCLUSION: The main finding of this study is that, in the absence of circulating neutrophils, MMP-2 and MMP-9 expression and activity are still up-regulated following focal cerebral ischemia. Additionally, neutrophil depletion had no influence on indicators of ischemic brain damage including edema, hemorrhage, and infarct size. These findings indicate that, at least acutely, neutrophils are not a significant contributor of gelatinase activity associated with acute neurovascular damage after stroke

    The role of temporary accommodation buildings for post-disaster housing reconstruction

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    The number of houses damaged or destroyed after disasters is frequently large, and re-housing of homeless people is one of the most important tasks of reconstruction programmes. Reconstruction works often last long and during that time, it is essential to provide victims with the minimum conditions to live with dignity, privacy, and protection. This research intends to demonstrate the crucial role of temporary accommodation buildings to provide spaces where people can live and gradually resume their life until they have a permanent house. The study also aims to identify the main problems of temporary accommodation strategies and to discuss some principles and guidelines in order to reach better design solutions. It is found that temporary accommodation is an issue that goes beyond the simple provision of buildings, since the whole space for temporary settlement is important. Likewise, temporary accommodation is a process that should start before a disaster occurs, as a preventive pre-planning. In spite of being temporary constructions, these housing buildings are one of the most important elements to provide in emergency scenarios, contributing for better recovery and reconstruction actions.The first author gratefully acknowledges the financial support of Fundacao para a Ciencia e a Tecnologia, FCT, through grant SFRH/BD/73853/2010

    Comparison of spin anisotropy and exchange alternation

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    Quasiā€1ā€D magnetic systems with on the one hand an Isingā€Heisenberg type spin anisotropy and on the other hand an alternating (dimerized) character have many interesting features in common and a few interesting differences in their phase behavior and general magnetic properties. This report reviews results rather scattered in the literature in addition to presenting new results. These rather complex quantum models present a theoretical challenge. It is also hoped that this work will be helpful to magnetochemists interested in identifying the underlying magnetic character of their systems, and to experimentalists in general
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