1,456 research outputs found

    Motion-base simulator study of control of an externally blown flap STOL transport aircraft after failure of an outboard engine during landing approach

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    A moving-base simulator investigation of the problems of recovery and landing of a STOL aircraft after failure of an outboard engine during final approach was made. The approaches were made at 75 knots along a 6 deg glide slope. The engine was failed at low altitude and the option to go around was not allowed. The aircraft was simulated with each of three control systems, and it had four high-bypass-ratio fan-jet engines exhausting against large triple-slotted wing flaps to produce additional lift. A virtual-image out-the-window television display of a simulated STOL airport was operating during part of the investigation. Also, a simple heads-up flight director display superimposed on the airport landing scene was used by the pilots to make some of the recoveries following an engine failure. The results of the study indicated that the variation in visual cues and/or motion cues had little effect on the outcome of a recovery, but they did have some effect on the pilot's response and control patterns

    Flight investigation of piloting techniques and crosswind limitations using a research type crosswind landing gear

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    A research-type crosswind landing gear was tested in a flight program which used a light STOL transport in strong crosswind conditions. The research-type crosswind landing gear used enabled the airplane to land to crosswinds up to a magnitude of 25 to 30 knots. Three modes of landing-gear operation were investigated: preset, automatic, and castor (passive self-alignment). Actual test data and histograms are given for the 195 'visual flight rules' crosswind landings made

    Stability of Solid State Reaction Fronts

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    We analyze the stability of a planar solid-solid interface at which a chemical reaction occurs. Examples include oxidation, nitridation, or silicide formation. Using a continuum model, including a general formula for the stress-dependence of the reaction rate, we show that stress effects can render a planar interface dynamically unstable with respect to perturbations of intermediate wavelength

    Three Keys to Success for Principals (and Their Teachers)

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    This is the author's accepted manuscript, post peer-review. The publisher's official version is available at: http://dx.doi.org/10.1080/00228958.2008.10516527.What is successful leadership and how can leadership concepts be applied to schools? Hundreds of books and articles and a plethora of executive seminars describe what leadership is and propose strategies for what effective leaders do. Most of these writings and presentations, however, focus on business, with much less information available about how to lead schools. In addition, there is a diversity of opinions about what makes leaders effective. This article suggests that it is possible to extract, reframe, and apply the best of what is known about leadership to help principals be more successful. Moreover, if principals are successful, teachers also are positioned to be successful, with the ultimate impact being successful student learning

    Body Composition as a Predictor of Toxicity in Patients Receiving Anthracycline and Taxane–Based Chemotherapy for Early-Stage Breast Cancer

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    Poor body composition metrics (BCM) are associated with inferior cancer outcomes; however, in early breast cancer (EBC) there is a paucity of evidence regarding BCM’s impact on toxicities. This study investigates associations between BCM and treatment-related toxicity in EBC patients receiving anthracyclines-taxane based chemotherapy

    Skeletal Muscle Measures as Predictors of Toxicity, Hospitalization, and Survival in Patients with Metastatic Breast Cancer Receiving Taxane-Based Chemotherapy

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    Severe skeletal muscle (SM) loss (sarcopenia), is associated with poor cancer outcomes including reduced survival and increased toxicity. This study investigates SM measures in metastatic breast cancer (MBC) patients receiving first line taxane-based chemotherapy and evaluates associations with treatment toxicity and other outcomes

    Skeletal muscle measures and physical function in older adults with cancer: sarcopenia or myopenia?

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    BACKGROUND: Skeletal muscle loss, commonly known as sarcopenia, is highly prevalent in older adults and linked with adverse outcomes in cancer, yet the definition and role of sarcopenia remains uncertain. The aim of this study was to examine the association of Computerized Tomography (CT) assessed skeletal muscle measures with physical function in older adults with cancer. RESULTS: CTs for 185 patients were available. Median age 73 (IQR 68-76) and 56.5% female. After controlling for sex and BMI, we found no evidence that SMI was associated with physical function impairments. Both SMD and SMG were associated physical function impairments and higher values were associated with decreased limitations in instrumental activities of daily living (RR 0.84 [CI 0.73-0.96] and 0.94 [CI 0.89-0.99], respectively), climbing stairs (RR 0.84 [CI 0.76-0.94] and 0.91 [CI 0.87-0.96]), walking 1 block (RR 0.77 [CI 0.67-0.90] and 0.91 [CI 0.85-0.97]), and prolonged Timed Up and Go (RR 0.83 [CI 0.75-0.92] and 0.92 [CI 0.88-0.96]). MATERIALS AND METHODS: Using the Carolina Senior Registry, we identified patients with CT imaging performed within 60 days +/- of baseline geriatric assessment (GA). Skeletal muscle area and density (SMD) were analyzed from L3 lumbar segments. Muscle area and height (m2) were used to calculate skeletal muscle index (SMI). Skeletal Muscle Gauge (SMG) was created by multiplying SMI x SMD. CONCLUSIONS: Skeletal muscle mass as assessed from CT imaging was not associated with physical function impairments. Skeletal muscle radiodensity was more associated with physical function and may aid in identifying older adults at risk for functional impairments

    Structure and oxidation kinetics of the Si(100)-SiO2 interface

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    We present first-principles calculations of the structural and electronic properties of Si(001)-SiO2 interfaces. We first arrive at reasonable structures for the c-Si/a-SiO2 interface via a Monte-Carlo simulated annealing applied to an empirical interatomic potential, and then relax these structures using first-principles calculations within the framework of density-functional theory. We find a transition region at the interface, having a thickness on the order of 20\AA, in which there is some oxygen deficiency and a corresponding presence of sub-oxide Si species (mostly Si^+2 and Si^+3). Distributions of bond lengths and bond angles, and the nature of the electronic states at the interface, are investigated and discussed. The behavior of atomic oxygen in a-SiO2 is also investigated. The peroxyl linkage configuration is found to be lower in energy than interstitial or threefold configurations. Based on these results, we suggest a possible mechanism for oxygen diffusion in a-SiO2 that may be relevant to the oxidation process.Comment: 7 pages, two-column style with 6 postscript figures embedded. Uses REVTEX and epsf macros. Also available at http://www.physics.rutgers.edu/~dhv/preprints/index.html#ng_sio

    A randomized controlled trial of outpatient CAncer REhabilitation for older adults: The CARE Program

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    Large numbers of older adults (aged 65 years or older) are surviving cancer; however, many survivors report decreased quality of life (QOL) and limitations in activities of daily living (ADL) and instrumental activities of daily living (IADL) both during and after treatment [1–3]. Occupational and physical therapy (OT/PT) are services focused on improving functional status and QOL that are largely unexplored and underutilized in cancer survivorship care [4, 5]

    Envisioning sustainable tourism futures: An evaluation of the futures wheel method

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    Methods for researching the future have grown both in variety and rigour, offering new opportunities for understanding sustainable tourism. This paper discusses the value of futures research as a tool for envisioning and planning sustainable tourism futures but observes that there is greater potential for the use of futures methods in tourism. The aim of this paper is to evaluate the usefulness of a particular method known as the futures wheel as a sustainable planning tool for tourism decision makers and researchers. The futures wheel method is combined with a grounded theory approach to capture and distil the tacit knowledge of three 'expert' think tanks. The evaluation suggests that the futures wheel is a useful tool for researching sustainable tourism futures but that its potential may be enhanced if it can be combined with other futures research methods
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