32,551 research outputs found

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

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    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

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

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    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

    Recombination Algorithms and Jet Substructure: Pruning as a Tool for Heavy Particle Searches

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    We discuss jet substructure in recombination algorithms for QCD jets and single jets from heavy particle decays. We demonstrate that the jet algorithm can introduce significant systematic effects into the substructure. By characterizing these systematic effects and the substructure from QCD, splash-in, and heavy particle decays, we identify a technique, pruning, to better identify heavy particle decays into single jets and distinguish them from QCD jets. Pruning removes protojets typical of soft, wide angle radiation, improves the mass resolution of jets reconstructing a heavy particle decay, and decreases the QCD background. We show that pruning provides significant improvements over unpruned jets in identifying top quarks and W bosons and separating them from a QCD background, and may be useful in a search for heavy particles.Comment: 33 pages, 42 figure

    R. K. Narayanswami B.A.B.L. Engine Driver : Story-Telling and Memory in The Grandmother’s Tale, and Selected Stories

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    Much like the Nambi of this tale, R. K. Narayan has merited his reputation as a marvelous storyteller. Noted for his laser-beam focus on the closely-imagined Malgudi, he has come to be recognized as the Indian novelist, from whose pen many readers expected all the accumulated wisdom of the subcontinent\u27s abiding concern for transcendence. While such guru-ization amused Narayan, it also elicited his quietly sustained argument against procrustean templates by which the west insisted on reading him as typically Indian.

    Projectile-shape dependence of impact craters in loose granular media

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    We report on the penetration of cylindrical projectiles dropped from rest into a dry, noncohesive granular medium. The cylinder length, diameter, density, and tip shape are all explicitly varied. For deep penetrations, as compared to the cylinder diameter, the data collapse onto a single scaling law that varies as the 1/3 power of the total drop distance, the 1/2 power of cylinder length, and the 1/6 power of cylinder diameter. For shallow penetrations, the projectile shape plays a crucial role with sharper objects penetrating deeper.Comment: 3 pages, 3 figures; experimen

    An exploration of infant feeding experiences of women in Lincolnshire in the early postnatal period

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    Executive Summary Breastfeeding initiation and maintenance rates within Lincolnshire remain lower than the average for the East Midlands and England. Rates of initiation of breastfeeding at birth in 2010/2011 were 72% in Lincolnshire, compared to an initiation rate in England of 74%. The percentage of babies still being either partially or exclusively breastfed at 6 – 8 weeks dropped to 39% in Lincolnshire in comparison to 46% in England (NHS Lincolnshire, 2011). The purpose of this qualitative research was to gain an understanding of primigravid women‟s breastfeeding experience in the first 6 – 8 week postpartum period. Whilst valuable audit data is held on infant feeding methods in Lincolnshire, this research focuses on offering insights into the experiences of new mothers in order to better understand their feeding experiences and decisions, with a view to understanding differences in rates. The objectives of the study were: PRIMARY OBJECTIVE To describe women‟s experiences of breastfeeding SECONDARY OBJECTIVES To determine women‟s perceptions of breastfeeding To identify the factors that influence breastfeeding duration and cessation. The study used phenomenological principles to understand the lived experiences of the women. The study focused on women who were living in the county of Lincolnshire. Ethical approval was granted by the University of Nottingham and the National Research Ethics Committee. Two methods of data collection were used: Personal diaries 48 primigravid women over 34 weeks gestation were invited to complete detailed daily diaries of their infant feeding experiences in the 6 to 8 week postnatal period. 22 diaries were completed, a response rate of 46%. In-depth interviews A sub-sample of 13 women participated in a face-to-face interview which explored their infant feeding experiences and factors that affected their decision to continue or to discontinue breastfeeding. Data analysis utilised phenomenological principles that proceeded from coding to category development to themes
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