653 research outputs found

    QCSEE under-the-wing engine-wing-flap aerodynamic profile characteristics

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    As part of a broad-based NASA program to provide a technology base for future propulsion requirements for powered-lift aircraft, the Quiet, Clean, Short-Haul, Experimental Engine (QCSEE) program was begun by the Lewis Research Center in 1974. The initial buildup of the under-the-wing (UTW) engine was tested by the contractor at his test site. The UTW engine was delivered to Lewis in 1978 for further testing with wing and flap segments simulating an installation on a short-haul transport aircraft. The engine was also tested alone as an aid in identifying the various noise sources and their levels. As part of these tests the aerodynamic profiles at the exhaust nozzle and on the surfaces and in the wake of the wing-flap system were measured. This report documents, in plots and tabular form, the significant results from those tests. The results are presented as tabulations of aerodynamic data for all of the test points and as profiles of pressure, temperature, velocity, and normalized velocity and pressure for selected conditions. One of the main conclusions was that the measured flap surface temperatures were surprisingly low for both approach and takeoff flap settings

    Real-Gas Effects and Phase Separation in Underexpanded Jets at Engine-Relevant Conditions

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    A numerical framework implemented in the open-source tool OpenFOAM is presented in this work combining a hybrid, pressure-based solver with a vapor-liquid equilibrium model based on the cubic equation of state. This framework is used in the present work to investigate underexpanded jets at engine-relevant conditions where real-gas effects and mixture induced phase separation are probable to occur. A thorough validation and discussion of the applied vapor-liquid equilibrium model is conducted by means of general thermodynamic relations and measurement data available in the literature. Engine-relevant simulation cases for two different fuels were defined. Analyses of the flow field show that the used fuel has a first order effect on the occurrence of phase separation. In the case of phase separation two different effects could be revealed causing the single-phase instability, namely the strong expansion and the mixing of the fuel with the chamber gas. A comparison of single-phase and two-phase jets disclosed that the phase separation leads to a completely different penetration depth in contrast to single-phase injection and therefore commonly used analytical approaches fail to predict the penetration depth.Comment: Preprint submitted to AIAA Scitech 2018, Kissimmee, Florid

    Effect of Ambrotose AO® on resting and exercise-induced antioxidant capacity and oxidative stress in healthy adults

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    <p>Abstract</p> <p>Background</p> <p>The purpose of this investigation was to determine the effects of a dietary supplement (Ambrotose AO<sup>®</sup>) on resting and exercise-induced blood antioxidant capacity and oxidative stress in exercise-trained and untrained men and women.</p> <p>Methods</p> <p>25 individuals (7 trained and 5 untrained men; 7 trained and 6 untrained women) received Ambrotose AO<sup>® </sup>(4 capsules per day = 2 grams per day) or a placebo for 3 weeks in a random order, double blind cross-over design (with a 3 week washout period). Blood samples were collected at rest, and at 0 and 30 minutes following a graded exercise treadmill test (GXT) performed to exhaustion, both before and after each 3 week supplementation period. Samples were analyzed for Trolox Equivalent Antioxidant Capacity (TEAC), Oxygen Radical Absorbance Capacity (ORAC), malondialdehyde (MDA), hydrogen peroxide (H<sub>2</sub>O<sub>2</sub>), and nitrate/nitrite (NOx). Quality of life was assessed using the SF-12 form and exercise time to exhaustion was recorded. Resting blood samples were analyzed for complete blood count (CBC), metabolic panel, and lipid panel before and after each 3 week supplementation period. Dietary intake during the week before each exercise test was recorded.</p> <p>Results</p> <p>No condition effects were noted for SF-12 data, for GXT time to exhaustion, or for any variable within the CBC, metabolic panel, or lipid panel (p > 0.05). Treatment with Ambrotose AO<sup>® </sup>resulted in an increase in resting levels of TEAC (p = 0.02) and ORAC (p < 0.0001). No significant change was noted in resting levels of MDA, H<sub>2</sub>O<sub>2</sub>, or NOx (p > 0.05). Exercise resulted in an acute increase in TEAC, MDA, and H<sub>2</sub>O<sub>2 </sub>(p < 0.05), all which were higher at 0 minutes post exercise compared to pre exercise (p < 0.05). No condition effects were noted for exercise related data (p > 0.05), with the exception of ORAC (p = 0.0005) which was greater at 30 minutes post exercise for Ambrotose AO<sup>® </sup>compared to placebo.</p> <p>Conclusion</p> <p>Ambrotose AO<sup>® </sup>at a daily dosage of 4 capsules per day increases resting blood antioxidant capacity and may enhance post exercise antioxidant capacity. However, no statistically detected difference is observed in resting or exercise-induced oxidative stress biomarkers, in quality of life, or in GXT time to exhaustion.</p

    Montmorency cherry juice reduces muscle damage caused by intensive strength exercise.

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    addresses: Sports and Exercise Science Research Centre, London South Bank University, London, United Kingdom. [email protected]: Clinical Trial; Journal Article; Research Support, Non-U.S. Gov'tThis is a non-final version of an article published in final form in Medicine and Science in Sports and Exercise, 2011, Vol. 43, Issue 8, pp. 1544 – 1551. © 2011 American College of Sports Medicine (ACSM)Montmorency cherries contain high levels of polyphenolic compounds including flavonoids and anthocyanins possessing antioxidant and anti-inflammatory effects. We investigated whether the effects of intensive unilateral leg exercise on oxidative damage and muscle function were attenuated by consumption of a Montmorency cherry juice concentrate using a crossover experimental design

    Inference on inspiral signals using LISA MLDC data

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    In this paper we describe a Bayesian inference framework for analysis of data obtained by LISA. We set up a model for binary inspiral signals as defined for the Mock LISA Data Challenge 1.2 (MLDC), and implemented a Markov chain Monte Carlo (MCMC) algorithm to facilitate exploration and integration of the posterior distribution over the 9-dimensional parameter space. Here we present intermediate results showing how, using this method, information about the 9 parameters can be extracted from the data.Comment: Accepted for publication in Classical and Quantum Gravity, GWDAW-11 special issu

    Report on the first round of the Mock LISA Data Challenges

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    The Mock LISA Data Challenges (MLDCs) have the dual purpose of fostering the development of LISA data analysis tools and capabilities, and demonstrating the technical readiness already achieved by the gravitational-wave community in distilling a rich science payoff from the LISA data output. The first round of MLDCs has just been completed: nine data sets containing simulated gravitational wave signals produced either by galactic binaries or massive black hole binaries embedded in simulated LISA instrumental noise were released in June 2006 with deadline for submission of results at the beginning of December 2006. Ten groups have participated in this first round of challenges. Here we describe the challenges, summarise the results, and provide a first critical assessment of the entries.Comment: Proceedings report from GWDAW 11. Added author, added reference, clarified some text, removed typos. Results unchanged; Removed author, minor edits, reflects submitted versio
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