51,278 research outputs found
Influence of configuration details on the subsonic characteristics of a space shuttle orbiter design
An investigation was conducted in the Langley low-turbulence pressure tunnel of a model of a space shuttle orbiter design in order to determine the influence of minor configuration geometric details on the aerodynamic characteristics at subsonic speeds. A plane wing was tested with a small planform fillet; a twisted wing was tested with both a small and a large planform fillet. Tailored attitude-control propulsion-system wing-tip and body pods, trisegmented elevons, and canopy effects were also investigated. The tests were conducted at angles of attack from -3 deg to 24 deg for sideslip angles of 0 deg and 6 deg and at a Mach number of 0.25
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Modelling the injured spinal cord using 3-dimensional cell cultures; strategies for improving tissue engineered repair
Abstract not available
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CO J = 3ā2 and J = 2ā1 mapping and spectroscopy of NGC 7027
We present spectra and mapping for NGC 7072 in the J = 3ā2 and J = 2ā1 transitions of CO. The central profile at J = 2ā1 is shown to be very similar to the J = 1ā0 spectrum measured by Thronson (1983), and this implies a source expansion at roughly constant velocity. The J = 3ā2 line however appears weaker, with evidence for appreciable quenching of the higher velocity components. Detailed modelling f the source indicates that densities n must vary appreciably with shell radius R(as nĪ± R-a, where Ī±ā„2), and this leads to a corresponding steep radial decrease in the radiation temperature TR. In consequence, the source FWHM is found to decrease appreciably iwth increasing transition frequency, a trend which appears also to be confirmed by our central J = 3ā2 scans. It is not however possible to constrain gas kinetic tempertures TK, the level of CO thermalisation, or shell mass M with any degree of confidence - both low and high mass models appear capable of replicating our spectra.
Finally, the J = 2ā1 spatial velocity map displays evidence for a decrease in velocity width towards the outer regions of the nebula; a feature which is expected of most outflow models. The J = 3ā2 map also indicates the presence of a nebular extension to the north-west of the peak emission core, although this is not reproduced in the corresponding J = 1ā0 map of Mufson et al. (1975)
Development of field ionization for the improvement of mass spectrometry Interim scientific report, 25 Mar. 1968 - 25 Mar. 1969
Field ionization for improvment of mass spectrometr
Supporting research and development in ambulance services: research for better healthcare in prehospital settings
Background This paper discusses recent developments in research support for ambulance trusts in England and Wales and how this could be designed to lead to better implementation, collaboration in and initiation of high-quality research to support a truly evidence-based service.
Method The National Ambulance Research Steering Group was set up in 2007 to establish the strategic direction for involvement of regional ambulance services in developing relevant and well-designed research for improving the quality of services to patients.
Results Ambulance services have been working together and with academic partners to implement research and to participate, collaborate and lead the design of research that is relevant for patients and ambulance services.
Conclusion New structures to support the strategic development of ambulance and prehospital research will help address gaps in the evidence for health interventions and service delivery in prehospital and ambulance care and ensure that ambulance services can increase their capacity and capability for high-quality research
Mid-Infrared Observations of Planetary Nebulae detected in the GLIMPSE 3D Survey
We present mapping, profiles and photometry for 24 planetary nebulae (PNe)
detected in the GLIMPSE 3D mid-infrared (MIR) survey of the Galactic plane. The
PNe show many of the properties observed in previous studies of these sources,
including evidence for longer wave emission from outside of the ionised zones,
a likely consequence of emission from polycyclic aromatic hydrocarbons (PAHs)
within the nebular photo-dissociation regimes (PDRs). We also note variations
in 5.8/4.5 and 8.0/4.5 microns flux ratios with distance from the nuclei;
present evidence for enhanced MIR emission in the halos of the sources; and
note evidence for variations in colour with nebular evolution.Comment: 35 pages, 28 figures, Accepted for publication in Revista Mexicana de
Astronomia y Astrofisica (RevMexAA). 61 pages in arXi
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Near infrared spectroscopy of W51 IRS-2
Near-infrared spectra at 2.95-3.5 Ī¼m and 3.99-10 Ī¼m have been obtained towards W51 IRS-2 and its surroundings, in order to investigate the spatial variations in intensity of the 3.28 Ī¼m unidentified feature and the 4.05 Ī¼m Brackett-Ī± line. The Br-Ī± and 3.28 Ī¼m features occupy a broadly similar spatial zone, which is characterised by an unresolved core responsible for most of the emission, and an extended and considerably weaker halo. Grain properties required to excite the 4.28 microns line, the nature of the 3.28 Ī¼m emission, and its relation to the source structure are discussed
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