9,465 research outputs found

    Noise measurements at Stockton Airport obtained during engineering evaluation of two-segment approaches in a 727-222 aircraft

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    The results of acoustic measurements made on a 727-222 aircraft during standard ILS and two-segment approaches are presented. The aircraft was equipped with a special purpose glide slope computer to provide the capability of making two-segment noise abatement approaches. For upper segment computations, the computer used barometric-corrected pressure altitude and the slant range to a DME transmitter which was colocated with the glide slope transmitter. The computer used the ILS glide slope deviation for lower segment computations. Additional measurements were made on 737 revenue aircraft using the Stockton Airport. The purpose of the acoustical portion of the test was to measure and identify the noise levels during the various approaches

    Noise measurements taken at LAX during operational evaluation of two-segment approaches in a 727-200 aircraft

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    A series of seven noise measurements were made each day over a period of fifteen days. The first and last flights each day were made by a specially instrumented 727-200 aircraft being used to evaluate the operational effectiveness of two-segment noise abatement approaches in scheduled service. Noise measurements were made to determine the noise reduction benefits of the two-segment approaches

    Bioactive composites for bone tissue engineering

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    One of the major challenges of bone tissue engineering is the production of a suitable scaffold material. In this review the current composite materials options available are considered covering both the methods of both production and assessing the scaffolds. A range of production routes have been investigated ranging from the use of porogens to produce the porosity through to controlled deposition methods. The testing regimes have included mechanical testing of the materials produced through to in vivo testing of the scaffolds. While the ideal scaffold material has not yet been produced, progress is being made

    Computer program to assess impact of fatigue and fracture criteria on weight and cost of transport aircraft

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    A preliminary design analysis tool for rapidly performing trade-off studies involving fatigue, fracture, static strength, weight, and cost is presented. Analysis subprograms were developed for fatigue life, crack growth life, and residual strength; and linked to a structural synthesis module which in turn was integrated into a computer program. The part definition module of a cost and weight analysis program was expanded to be compatible with the upgraded structural synthesis capability. The resultant vehicle design and evaluation program is named VDEP-2. It is an accurate and useful tool for estimating purposes at the preliminary design stage of airframe development. A sample case along with an explanation of program applications and input preparation is presented

    Astrometric Detection of Terrestrial Planets in the Habitable Zones of Nearby Stars with SIM PlanetQuest

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    SIM PlanetQuest (Space Interferometry Mission) is a space-borne Michelson interferometer for precision stellar astrometry, with a nine meter baseline, currently slated for launch in 2015. One of the principal science goals is the astrometric detection and orbit characterization of terrestrial planets in the habitable zones of nearby stars. Differential astrometry of the target star against a set of reference stars lying within a degree will allow measurement of the target star's reflex motion with astrometric accuracy of 1 micro-arcsecond in a single measurement. We assess SIM's capability for detection (as opposed to characterization by orbit determination) of terrestrial planets in the habitable zones of nearby solar-type stars. We compare SIM's performance on target lists optimized for the SIM and Terrestrial Planet Finder Coronograph (TPF-C) missions. Performance is quantified by three metrics: minimum detectable planet mass, number and mass distribution of detected planets, and completeness of detections in each mass range. Finally, we discuss the issue of confidence in detections and non-detections, and show how information from SIM's planet survey can enable TPF to increase its yield of terrestrial planets.Comment: Minor corrections to figures and tables. 46 pages, 27 figures. To appear in PASP (Publications of the Astronomical Society of the Pacific), May 200

    On the edge of a new frontier: Is gerontological social work in the UK ready to meet twenty-first-century challenges?

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    This article is available open access through the publisher’s website. Copyright @ 2013 The Authors.This article explores the readiness of gerontological social work in the UK for meeting the challenges of an ageing society by investigating the focus on work with older people in social work education and the scope of gerontological social work research. The discussion draws on findings from two exploratory studies: a survey of qualifying master's programmes in England and a survey of the content relating to older people over a six-year period in four leading UK social work journals. The evidence from master's programmes suggests widespread neglect of ageing in teaching content and practice learning. Social work journals present a more nuanced picture. Older people emerge within coverage of generic policy issues for adults, such as personalisation and safeguarding, and there is good evidence of the complexity of need in late life. However, there is little attention to effective social work interventions, with an increasingly diverse older population, or to the quality of gerontological social work education. The case is made for infusing content on older people throughout the social work curriculum, for extending practice learning opportunities in social work with older people and for increasing the volume and reporting of gerontological social work research.Brunel Institute for Ageing Studie

    Combined Reconstruction and Registration of Digital Breast Tomosynthesis

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    Digital breast tomosynthesis (DBT) has the potential to en- hance breast cancer detection by reducing the confounding e ect of su- perimposed tissue associated with conventional mammography. In addi- tion the increased volumetric information should enable temporal datasets to be more accurately compared, a task that radiologists routinely apply to conventional mammograms to detect the changes associated with ma- lignancy. In this paper we address the problem of comparing DBT data by combining reconstruction of a pair of temporal volumes with their reg- istration. Using a simple test object, and DBT simulations from in vivo breast compressions imaged using MRI, we demonstrate that this com- bined reconstruction and registration approach produces improvements in both the reconstructed volumes and the estimated transformation pa- rameters when compared to performing the tasks sequentially

    Secondary school admissions

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