41,343 research outputs found

    Flow field survey near the rotational plane of an advanced design propeller on a JetStar airplane

    Get PDF
    An investigation was conducted to obtain upper fuselage surface static pressures and boundary layer velocity profiles below the centerline of an advanced design propeller. This investigation documents the upper fuselage velocity flow field in support of the in-flight acoustic tests conducted on a JetStar airplane. Initial results of the boundary layer survey show evidence of an unusual flow disturbance, which is attributed to the two windshield wiper assemblies on the aircraft. The assemblies were removed, eliminating the disturbances from the flow field. This report presents boundary layer velocity profiles at altitudes of 6096 and 9144 m (20,000 and 30,000 ft) and Mach numbers from 0.6 to 0.8, and it investigated the effects of windshield wiper assemblies on these profiles. Because of the unconventional velocity profiles that were obtained with the assemblies mounted, classical boundary layer parameters, such as momentum and displacement thicknesses, are not presented. The effects of flight test variables (Mach number and angles of attack and sideslip) and an advanced design propeller on boundary layer profiles - with the wiper assemblies mounted and removed - are presented

    Impact of large-scale dynamic versus thermodynamic climate conditions on contrasting tropical cyclone genesis frequency

    Get PDF
    Significant advances have been made in understanding the key climate factors responsible for tropical cyclone (TC) activity, yet any theory that estimates likelihood of observed TC formation rates from mean climate states remains elusive. The present study investigates how the extremes of observed TC genesis (TCG) frequency during peak TC seasons are interrelated with distinct changes in the large-scale climate conditions over different ocean basins using the global International Best Track Archive for Climate Stewardship (IBTrACS) dataset and ERA-Interim for the period 1979–2014. Peak TC seasons with significantly high and low TCG frequency are identified for five major ocean basins, and their substantial spatial changes in TCG are noted with regionally distinct differences. To explore the possible climate link behind such changes, a suite of potentially relevant dynamic and thermodynamic climate conditions is analyzed. Results indicate that the observed changes in extreme TCG frequency are closely linked with distinct dominance of specific dynamic and thermodynamic climate conditions over different regions. While the combined influences of dynamic and thermodynamic climate conditions are found to be necessary for modulating TC formation rate over the North Atlantic, eastern Pacific, and southern Indian Oceans, significant changes in large-scale dynamic conditions appear to solely control the TCG frequency over the western Pacific and South Pacific basins. Estimation of the fractional changes in genesis-weighted climate conditions also indicates the coherent but distinct competing effects of different climate conditions on TCG frequency. The present study further points out the need for revising the existing genesis indices for estimating TCG frequency over individual basins

    Flight evaluation of a hydromechanical backup control for the digital electronic engine control system in an F100 engine

    Get PDF
    The backup control (BUC) features, the operation of the BUC system, the BUC control logic, and the BUC flight test results are described. The flight test results include: (1) transfers to the BUC at military and maximum power settings; (2) a military power acceleration showing comparisons bvetween flight and simulation for BUC and primary modes; (3) steady-state idle power showing idle compressor speeds at different flight conditions; and (4) idle-to-military power BUC transients showing where cpmpressor stalls occurred for different ramp rates and idle speeds. All the BUC transfers which occur during the DEEC flight program are initiated by the pilot. Automatic transfers to the BUC do not occur

    The Unitary Patent Package, the Court of Justice of the European Union, and Brexit: (Ir)reconcilable?

    Get PDF
    This is the author accepted manuscript. The final version is available electronically via Westlaw UK.For seventy years, debates in the European patent community have centred on the introduction of a unitary patent system. For an efficient and effective European patent system, there are two key aspects – the promotion of harmonisation and the consideration of wider societal implications. In considering these two key aspects, this article focuses on the role of the Court of Justice of the European Union (CJEU) in the Unitary Patent Package (UPP) and the added complication of Brexit. In doing so, it examines the relevant institutional issues that have arisen in the lead up to the finalisation of the UPP, which continue to cause issues as a result of Brexit, and proposes a new way forward for reconciliation. It is argued that the continued questioning of the role of the CJEU goes against the overarching goal of a harmonised patent system that still considers the wider implications of its decisions

    Value-based pricing for medical education?

    Get PDF
    No Abstract

    Newton: from certainty to probability?

    Get PDF
    This is the final version. Available from University of Chicago Press via the DOI in this recordNewton’s earliest publications contained scandalous epistemological claims: not only did he aim for certainty; he also claimed success. Some commentators argue that Newton ultimately gave up claims of certainty in favor of a high degree of probability. I argue that no such shift occurred. I examine the evidence of a probabilistic shift: a passage from query 23/31 of the Opticks and rule 4 of the Principia. Neither passage supports a probabilistic approach to natural philosophy. The aim of certainty, then, was an enduring feature of Newton’s methodology

    Medical education: The case for investment

    Get PDF
    No Abstract

    Point Of View: Online Assessment in Medical Education – Current Trends and Future Directions

    Get PDF
    No Abstrac

    Mobile Learning in Medical Education: Review

    Get PDF
    In the past several years, mobile learning made rapid inroads into the provision of medical education. There are significant advantages associated with mobile learning. These include high access, low cost, more  situated and contextual learning, convenience for the learner, continuous communication and interaction  between learner and tutor and between learner and other learners, and the ability to self-assess themselves  while learning. Like any other form of medical pedagogy, mobile learning has its downsides. Disadvantages of mobile learning include: inadequate technology, a risk of distraction from learning by using a device that can be used for multiple purposes, and the potential for breakdown in barriers between personal usage of the mobile  device and professional or educational use. Despite these caveats, there is no question but that mobile  learning offers much potential. In the future, it is likely that the strategy of mobile first, whereby providers of e-learning think of the user experience on a mobile first, will result in learners who increasingly expect that all e-learning provision will work seamlessly on a mobile device.KEYWORS: Medical education, mobile learning, technolog
    • …
    corecore