156 research outputs found

    Large-scale static investigation of circulation-control-wing concepts applied to upper surface-blowing aircraft

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    The use of a circulation control to deflect turbofan engine thrust beyond 90 deg. has been proven in full-scale static ground tests of the circulation-control-wing/upper-surface-blowing (CCW/USB) concept. This powered high-lift system employs a circular, blown trailing edge to replace the USB mechanical flaps to entrain engine-exhaust flow, and to obtain both a vertical-thrust component and an augmented circulation lift for short takeoff and landing (STOL) applications. Previous tests (Phase 1), done in 1982, of a basic configuration installed on the Quiet Short Haul Research Aircraft confirmed these CCW/USB systems capabilities. A second phase (Phase 2) of full-scale, static, thrust-deflection investigations has reconfirmed the ability to deflect engine thrust from 40 to 102 deg., depending on thrust level. Five new configurations were evaluated and performance improvements noted for those configurations with larger blown span, fences or favorable engine interactions, smaller slot height, and larger radii with less than 180 deg. of CCW surface arc. In general, a 90 deg. circular arc with a smaller slot height provided the best performance, demonstrating that adequate thrust turning can be produced by a trailing-edge shape which may have minimal cruise-performance penalty. Thrust deflections were achieved at considerably lower blowing momentum than was required for the baseline case of Phase 1. Improved performance and versatility were thus confirmed for the CCW/USB system applied to STOL aircraft, where the potential for developing a non-moving-parts pneumatic thrust deflector to rapidly vary horizontal force from thrust to drag, while maintaining constant vertical force, appears quite promising. The conversion from high-lift to lower-drag cruise mode by merely terminating the blowing provides an effective STOL aircraft system

    Static investigation of the circulation control wing/upper surface blowing concept applied to the quiet short haul research aircraft

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    Full scale static investigations were conducted on the Quiet Short Haul Research Aircraft (QSRA) to determine the thrust deflecting capabilities of the circulation control wing/upper surface blowing (CCW/USB) concept. This scheme, which combines favorable characteristics of both the A-6/CCW and QSRA, employs the flow entrainment properties of CCW to pneumatically deflect engine thrust in lieu of the mechanical USB flap system. Results show that the no moving parts blown system produced static thrust deflections in the range of 40 deg to 97 deg (depending on thrust level) with a CCW pressure of 208,900 Pa (30.3 psig). In addition, the ability to vary horizontal forces from thrust to drag while maintaining a constant vertical (or lift) value was demonstrated by varying the blowing pressure. The versatility of the CCW/USB system, if applied to a STOL aircraft, was confirmed, where rapid conversion from a high drag approach mode to a thrust recovering waveoff or takeoff configuration could be achieved by nearly instantaneous blowing pressure variation

    South African guideline for the use of chronic opioid therapy for chronic non-cancer pain

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    Chronic pain may have a significant impact on health-related quality of life and can be difficult to manage. In carefully selected patients, and as part of a comprehensive pain management strategy, opioid analgesia may help to achieve long-term pain control with a manageable side-effect profile and a low risk of serious adverse effects. However, appropriate evaluation, including biopsychosocial screening and risk screening is essential before initiating an opioid and during continued therapy. This guideline aims to assist practitioners in screening and selecting appropriate patients with chronic non-cancer pain to initiate, monitor and continue pain management with opioid therapy.The development of this guideline was supported by an unrestricted grant from Mundipharma who did not participate in the development or writing of the guideline. Dr M Raff has received honoraria for consultancies and non-restricted research grants from Mundipharma, Pfizer, Janssen Pharmaceutica, AstraZeneca, MSD, Eli Lilly, Aspen and Abbott Laboratories. Drs J Crosier and S Eppel have received honoraria from Mundipharma. Prof. H Meyer has received honoraria for consultancies and non-restricted research grants from Janssen Pharmaceutica, Eli Lilly, MSD and Mundipharma. Dr B Sarembock has received honoraria for consultancies and non-restricted research grants from MSD, AstraZeneca, Pfizer and Mundipharma. Dr D Webb has received professional fees for services to Abbott Laboratories, Adcock Ingram, Alcon Laboratories, AstraZeneca, Eli Lilly, Janssen Pharmaceutica, Mundipharma, Novartis, and Reckitt Beckiser Pharmaceuticals.http://www.samj.org.zaam201

    Motivations for the use and consumption of wildlife products

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    The dominant approach to combating the illegal wildlife trade has traditionally been to restrict the supply of wildlife products. Yet conservationists increasingly recognize the importance of implementing demand‐side interventions that target the end consumers in the trade chain. Their aim is to curb the consumption of wildlife or shift consumption to more sustainable alternatives. However, there are still considerable knowledge gaps in understanding of the diversity of consumer motivations in the context of illegal wildlife trade, which includes hundreds of thousands of species, different uses, and diverse contexts. Based on consultation with multiple experts from a diversity of backgrounds, nationalities, and focal taxa, we developed a typology of common motivations held by wildlife consumers that can be used to inform conservation interventions. We identified 5 main motivational categories for wildlife use: experiential, social, functional, financial, and spiritual, each containing subcategories. This framework is intended to facilitate the segmentation of consumers based on psychographics and allow the tailoring of interventions—whether behavior change campaigns, enforcement efforts, or incentive programs—to the specific context in which they will be used. Underlining the importance of consumer research and collaborating with local actors is an important step toward promoting a more systematic approach to the design of demand reduction interventions

    Gamow Shell Model Description of Weakly Bound Nuclei and Unbound Nuclear States

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    We present the study of weakly bound, neutron-rich nuclei using the nuclear shell model employing the complex Berggren ensemble representing the bound single-particle states, unbound Gamow states, and the non-resonant continuum. In the proposed Gamow Shell Model, the Hamiltonian consists of a one-body finite depth (Woods-Saxon) potential and a residual two-body interaction. We discuss the basic ingredients of the Gamow Shell Model. The formalism is illustrated by calculations involving {\it several} valence neutrons outside the double-magic core: 6−10^{6-10}He and 18−22^{18-22}O.Comment: 19 pages, 20 encapsulated PostScript figure

    TELAMON: Effelsberg monitoring of AGN jets with very-high-energy astroparticle emission -- I. Program description and sample characterization

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    Aims. We introduce the TELAMON program which is using the Effelsberg 100-m telescope to monitor the radio spectra of active galactic nuclei (AGN) under scrutiny in astroparticle physics, specifically TeV blazars and candidate neutrino-associated AGN. Here, we present and characterize our main sample of TeV-detected blazars. Methods. We analyze the data sample from the first ~2.5 years of observations between August 2020 and February 2023 in the range from 14 GHz to 45 GHz. During this pilot phase, we have observed all 59 TeV-detected blazars in the Northern Hemisphere (i.e., Dec. >0{\deg}) known at the time of observation. We discuss the basic data reduction and calibration procedures used for all TELAMON data and introduce a sub-band averaging method used to calculate average light curves for the sources in our sample. Results. The TeV-selected sources in our sample exhibit a median flux density of 0.12 Jy at 20 mm, 0.20 Jy at 14 mm and 0.60 Jy at 7 mm. The spectrum for most of the sources is consistent with a flat radio spectrum and we find a median spectral index (S(Îœ)∝ΜαS(\nu)\propto\nu^\alpha) of α=−0.11\alpha=-0.11. Our results on flux density and spectral index are consistent with previous studies of TeV-selected blazars. Compared to the GeV-selected F-GAMMA sample, TELAMON sources are significantly fainter in the radio band. This is consistent with the double-humped spectrum of blazars being shifted towards higher frequencies for TeV-emitters (in particular for high-synchrotron peaked BL Lac type objects), which results in a lower radio flux density. The spectral index distribution of our TeV-selected blazar sample is not significantly different from the GeV-selected F-GAMMA sample. Moreover, we present a strategy to track the light curve evolution of sources in our sample for future variability and correlation analysis.Comment: 16 pages, 11 figures, 4 tables, accepted for publication in A&

    TELAMON: Effelsberg Monitoring of AGN Jets with Very-High-Energy Astroparticle Emissions -- II. Polarization properties

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    We present recent results of the TELAMON program, which is using the Effelsberg 100-m telescope to monitor the radio spectra of active galactic nuclei (AGN) under scrutiny in astroparticle physics, namely TeV blazars and neutrino-associated AGN. Our sample includes all known Northern TeV-emitting blazars as well as blazars positionally coincident with IceCube neutrino alerts. Polarization can give additional insight into the source properties, as the polarized emission is often found to vary on different timescales and amplitudes than the total intensity emission. Here, we present an overview of the polarization properties of the TeV-emitting TELAMON sources at four frequencies in the 20 mm and 7 mm bands. While at 7 mm roughly 82 %82\,\% of all observed sources are found to be significantly polarized, for 20 mm the percentage is ∌58 %\sim58\,\%. We find that most of the sources exhibit mean fractional polarizations of <5%<5\%, matching the expectations of rather low polarization levels in these sources from previous studies at lower radio frequencies. Nevertheless, we demonstrate examples of how the polarized emission can provide additional information over the total intensity.Comment: 9 pages, 2 figures, Proceedings of the 38th International Cosmic Ray Conference (ICRC2023

    Applying behavioural theory to the challenge of sustainable development: using hairdressers as diffusers of more sustainable hair-care practices

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    The challenges presented by sustainable development are broadly accepted, yet resource use increases unabated. It is increasingly acknowledged that while technical solutions may play a part, a key issue is behaviour change. In response to this there has been a plethora of studies into how behaviour change can be enabled, predominantly from psychological and sociological perspectives. This has resulted in a substantial body of knowledge into the factors that drive behaviour change and how they can be manipulated to achieve desired social goals. In this paper we describe a study that draws on this body of knowledge to design an intervention to drive behaviour change across the hairdressing sector, and by the process of diffusion, across the vast social networks of this occupational group to influence domestic hair-care practices. The intervention was successful: hairdressers indicated positive intentions to adopt more sustainable practices within their salons and pass them onto their customers. The customer survey (N=776) confirms this: customers surveyed after their hairdresser attended the Green-Salon-Makeover intervention were significantly more likely to report that environmental issues had been considered in their salon visit and that they themselves would consider such issues in their hair-care practices at home than customers who were surveyed before the intervention

    Householders’ Mental Models of Domestic Energy Consumption: Using a Sort-And-Cluster Method to Identify Shared Concepts of Appliance Similarity

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    If in-home displays and other interventions are to successfully influence people's energy consumption, they need to communicate about energy in terms that make sense to users. Here we explore householders' perceptions of energy consumption, using a novel combination of card-sorting and clustering to reveal shared patterns in the way people think about domestic energy consumption. The data suggest that, when participants were asked to group appliances which they felt naturally 'went together', there are relatively few shared ideas about which appliances are conceptually related. To the extent participants agreed on which appliances belonged together, these groupings were based on activities (e.g., entertainment) and location within the home (e.g., kitchen); energy consumption was not an important factor in people's categorisations. This suggests messages about behaviour change aimed at reducing energy consumption might better be tied to social practices than to consumption itself
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