14,104 research outputs found
A study of high-altitude manned research aircraft employing strut-braced wings of high-aspect-ratio
The effect of increased wing aspect ratio of subsonic aircraft on configurations with and without strut bracing. Results indicate that an optimum cantilever configuration, with a wing aspect ratio of approximately 26, has a 19% improvement in cruise range when compared to a baseline concept with a wing aspect ratio of approximately 10. An optimum strut braced configuration, with a wing aspect ratio of approximately 28, has a 31% improvment in cruise range when compared to the same baseline concept. This improvement is mainly due to the estimated reduction in wing weight resulting from use of lifting struts. All configurations assume the same mission payload and fuel. The drag characteristics of the wings are enhanced with the use of laminar flow airfoils. A method for determining the extent of attainable natural laminar flow, and methods for preliminary structural design and for aerodynamic analysis of wings lifting struts are presented
Heavy ion induced Single Event Phenomena (SEP) data for semiconductor devices from engineering testing
The accumulation of JPL data on Single Event Phenomena (SEP), from 1979 to August 1986, is presented in full report format. It is expected that every two years a supplement report will be issued for the follow-on period. This data for 135 devices expands on the abbreviated test data presented as part of Refs. (1) and (3) by including figures of Single Event Upset (SEU) cross sections as a function of beam Linear Energy Transfer (LET) when available. It also includes some of the data complied in the JPL computer in RADATA and the SPACERAD data bank. This volume encompasses bipolar and MOS (CMOS and MHNOS) device data as two broad categories for both upsets (bit-flips) and latchup. It also includes comments on less well known phenomena, such as transient upsets and permanent damage modes
Incidence of and risk factors for perineal trauma: A prospective observational study
Background: Our aim was to describe the range of perineal trauma in women with a singleton vaginal birth and estimate the effect of maternal and obstetric characteristics on the incidence of perineal tears. Methods: We conducted a prospective observational study on all women with a planned singleton vaginal delivery between May and September 2006 in one obstetric unit, three freestanding midwifery-led units and home settings in South East England. Data on maternal and obstetric characteristics were collected prospectively and analysed using univariable and multivariable logistic regression. The outcome measures were incidence of perineal trauma, type of perineal trauma and whether it was sutured or not. Results: The proportion of women with an intact perineum at delivery was 9.6% (125/1,302) in nulliparae, and 31.2% (453/1,452) in multiparae, with a higher incidence in the community (freestanding midwifery-led units and home settings). Multivariable analysis showed multiparity (OR 0.52; 95% CI: 0.30-0.90) was associated with reduced odds of obstetric anal sphincter injuries (OASIS), whilst forceps (OR 4.43; 95% CI: 2.02-9.71), longer duration of second stage of labour (OR 1.49; 95% CI: 1.13-1.98), and heavier birthweight (OR 1.001; 95% CI: 1.001-1.001), were associated with increased odds. Adjusted ORs for spontaneous perineal truama were: multiparity (OR 0.42; 95% CI: 0.32-0.56); hospital delivery (OR 1.48; 95% CI: 1.01-2.17); forceps delivery (OR 2.61; 95% CI: 1.22-5.56); longer duration of second stage labour (OR 1.45; 95% CI: 1.28-1.63); and heavier birthweight (OR 1.001; 95% CI: 1.000-1.001). Conclusions: This large prospective study found no evidence for an association between many factors related to midwifery practice such as use of a birthing pool, digital perineal stretching in the second stage, hands off delivery technique, or maternal birth position with incidence of OASIS or spontaneous perineal trauma. We also found a low overall incidence of OASIS, and fewer second degree tears were sutured in the community than in the hospital settings. This study confirms previous findings of overall high incidence of perineal trauma following vaginal delivery, and a strong association between forceps delivery and perineal trauma. © 2013 Smith et al; licensee BioMed Central Ltd
Seasonal patterns of oral antihistamine and intranasal corticosteroid purchases from Australian community pharmacies : a retrospective observational study
Acknowledgments The abstract of this paper was presented at the Respiratory Effectiveness Group 2016 Annual Summit as a poster presentation with interim findings. The poster’s abstract was published in “Poster Abstracts” in The Journal of Thoracic Disease (Vol. 8, Supplement 5, 5 July 2016). http://jtd.amegroups.com/article/view/8504.Peer reviewedPublisher PD
Implementation of Patient-Reported Outcomes (PROMs) from specialist pain clinics in England and Wales:experience from a nationwide study
INTRODUCTION: Evaluating outcomes in routine clinical practice is a significant challenge for specialist pain clinics due to the complexity of interventions provided and the subjective nature of pain. This study reports findings from implementation of Patient Reported Outcomes (PROMs) in pain clinics in England and Wales between 2011 and 2013. METHODS: A paper-based questionnaire was administered at a first appointment in participating centres. This assessed quality of life, experience of health care and health care usage with postal follow-up at 6 and 12 months by the research team. Feasibility was assessed in terms of response rates, completion rates and outcomes. RESULTS: Ninety-one (56%) clinics participated, entering 9,588 patients (19% of those eligible). For responders, there was a 92% item completion rate. The dropout rate was high, 46% and 19% returned questions at 6 and 12 months, respectively. Quality of life at baseline was low, with a mean EQ5D-3L Time Trade Off value of 0.32. Amongst responders at 12 months, 92% continued to experience significant pain. For those with planned discharges 30% achieved the Minimal Important Change for quality of life. Nonetheless, 70% reported positive experiences of care. CONCLUSIONS: Patients attending UK pain clinics report an extraordinarily poor quality of life and difficulty with understanding their condition. Problems with PROMs implementation included initial recruitment, follow-up response rates, classification systems and benchmarking. Successful implementation should include use of electronic data capture, feedback and focus on gradual improvement. To achieve this would require extended periods of funding. SIGNIFICANCE: No nationwide evaluation of the effectiveness of specialist pain clinics had previously been attempted. Comparison of patient outcomes from services enables improvement. This work provides a platform to improve methods of routine PROMs capture in pain clinics, measure clinical effectiveness and identify areas for potential research
XAX: a multi-ton, multi-target detection system for dark matter, double beta decay and pp solar neutrinos
A multi-target detection system XAX, comprising concentric 10 ton targets of
136Xe and 129/131Xe, together with a geometrically similar or larger target of
liquid Ar, is described. Each is configured as a two-phase
scintillation/ionization TPC detector, enhanced by a full 4pi array of
ultra-low radioactivity Quartz Photon Intensifying Detectors (QUPIDs) replacing
the conventional photomultipliers for detection of scintillation light. It is
shown that background levels in XAX can be reduced to the level required for
dark matter particle (WIMP) mass measurement at a 10^-10 pb WIMP-nucleon cross
section, with single-event sensitivity below 10^-11 pb. The use of multiple
target elements allows for confirmation of the A^2 dependence of a coherent
cross section, and the different Xe isotopes provide information on the
spin-dependence of the dark matter interaction. The event rates observed by Xe
and Ar would modulate annually with opposite phases from each other for WIMP
mass >~100 GeV/c^2. The large target mass of 136Xe and high degree of
background reduction allow neutrinoless double beta decay to be observed with
lifetimes of 10^27-10^28 years, corresponding to the Majorana neutrino mass
range 0.01-0.1 eV, the most likely range from observed neutrino mass
differences. The use of a 136Xe-depleted 129/131Xe target will also allow
measurement of the pp solar neutrino spectrum to a precision of 1-2%.Comment: 16 pages with 17 figure
A proper understanding of Millikan
Ruth Millikan’s teleological theory of mental content is complex and often misunderstood. This paper motivates and clarifies some of the complexities of the theory, and shows that paying careful attention to its details yields answers to a number of common objections to teleological theories, in particular, the problem of novel mental states, the problem of functionally false beliefs, and problems about indeterminacy or multiplicity of function
HI Bright Galaxies in the Southern Zone of Avoidance
A blind survey for HI bright galaxies in the southern Zone of Avoidance, (212
deg < l < 36 deg; |b| < 5 deg), has been made with the 21 cm multibeam receiver
on the Parkes 64 m radiotelescope. The survey, sensitive to normal spiral
galaxies to a distance of about 40 Mpc and more nearby dwarfs, detected 110
galaxies. Of these, 67 have no counterparts in the NASA/IPAC Extragalactic
Database. In general, the uncataloged galaxies lie behind thicker obscuration
than do the cataloged objects. All of the newly-discovered galaxies have HI
flux integrals more than an order of magnitude lower than the Circinus galaxy.
The survey recovers the Puppis cluster and foreground group (Kraan-Korteweg &
Huchtmeier 1992), and the Local Void remains empty. The HI mass function
derived for the sample is satisfactorily fit by a Schechter function with
parameters alpha = 1.51 +- 0.12, Phi* = 0.006 +- 0.003, and log M* = 9.7 +-
0.10.Comment: To appear in The Astronomical Journa
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