Tracing Quasar Narrow-Line Regions Across Redshift: A Library of High S/N Optical Spectra

In a single optical spectrum, the quasar narrow-line region (NLR) reveals low density, photoionized gas in the host galaxy interstellar medium, while the immediate vicinity of the central engine generates the accretion disk continuum and broad emission lines. To isolate these two components, we construct a library of high S/N optical composite spectra created from the Sloan Digital Sky Survey (SDSS-DR7). We divide the sample into bins of continuum luminosity and Hbeta FWHM that are used to construct median composites at different redshift steps up to 0.75. We measure the luminosities of the narrow-emission lines [NeV]3427, [NeIII]3870, [OIII]5007, and [OII]3728 with ionization potentials (IPs) of 97, 40, 35, and 13.6 eV respectively. The high IP lines' luminosities show no evidence of increase with redshift consistent with no evolution in the AGN SED or the host galaxy ISM illuminated by the continuum. In contrast, we find that the [OII] line becomes stronger at higher redshifts, and we interpret this as a consequence of enhanced star formation contributing to the [OII] emission in host galaxies at higher redshifts. The SFRs estimated from the [OII] luminosities show a flatter increase with z than non-AGN galaxies given our assumed AGN contribution to the [OII] luminosity. Finally, we confirm an inverse correlation between the strength of the FeII4570 complex and both the [OIII] EW (though not the luminosity) and the width of the Hbeta line as known from the eigenvector 1 correlations.Comment: 17 pages, colour figures, accepted for publication in MNRA

AGN and starbursts at high redshift: High resolution EVN radio observations of the Hubble Deep Field

We present deep, wide-field European VLBI Network (EVN) 1.6 GHz observations of the Hubble Deep Field (HDF) region with a resolution of 0.025 arcseconds. Above the 210 microJy/beam (5sigma) detection level, the EVN clearly detects two radio sources in a field that encompasses the HDF and part of the Hubble Flanking Fields (HFF). The sources detected are: VLA J123644+621133 (a z=1.013, low-luminosity FR-I radio source located within the HDF itself) and VLA J123642+621331 (a dust enshrouded, optically faint, z=4.424 starburst system). A third radio source, J123646+621404, is detected at the 4sigma level. The VLBI detections of all three sources suggest that most of the radio emission of these particular sources (including the dusty starburst) is generated by an embedded AGN.Comment: 4 pages, 1 figure; Accepted by Astron. & Astrophys Letters ... See http://www.nfra.nl/~mag/hdf_evn.htm

Dynamic blade loading in the ERDA/NASA 100 kW and 200 kW wind turbines

Dynamic blade loads, including aerodynamic, gravitational, and inertial effects, are presented for two large horizontal-axis wind turbines: the ERDA-NASA 100 kW Mod-0 and 200 kw Mod-0A wind power systems. Calculated and measured loads are compared for an experimental Mod-0 machine in operation. Predicted blade loads are also given for the higher power Mod-0A wind turbine now being assembled for operation as part of a municipal power plant. Two major structural modifications have been made to the Mod-0 wind turbine for the purpose of reducing blade loads. A stairway within the truss tower was removed to reduce the impulsive aerodynamic loading caused by the tower wake on the downwind rotor blades. Also, the torsional stiffness of the yaw drive mechanism connecting the turbine nacelle to the tower was doubled to reduce rotor-tower interaction loads. Measured reductions in load obtained by means of these two modifications equaled or exceeded predictions

‘Joining a group was inspiring’: a qualitative study of service users’ experiences of yoga on social prescription

Background Yoga is becoming an increasingly popular holistic approach in the West to manage long-term health conditions. This study presents the evaluation of a pilot yoga intervention, Yoga4Health, that was developed for the NHS to be socially prescribed to patients at risk of developing specific health conditions (risk factors for cardiovascular disease, pre-diabetes, anxiety/depression or experiencing social isolation). The aim of this qualitative study was to explore service users’ experiences of Yoga4Health and the acceptability of the programme. Methods Qualitative data were collected from three sources: 1. Open-ended questions on questionnaires completed by services users at three different time-points (baseline, post intervention and 3 months); 2. Interviews and focus groups with a subset of participants (n = 22); 3. interviews with yoga teachers delivering Yoga4Health (n = 7). Each data source was analysed thematically, then findings were combined. Results Of participants completing baseline questionnaires (n = 240), 82.5% were female, 50% White, with a mean age of 53 (range 23–82) years. Baseline questionnaires revealed key motivations to attend Yoga4Health were to improve psychological and physical health, and believing Yoga4Health would be accessible for people with their health condition. Post-intervention, participants reported a range of benefits across psychological, physical and social domains from Yoga4Health. Increased confidence in self-management of health was also reported, and a number of participants described making positive lifestyle changes after attending the programme. Unanticipated benefits of yoga emerged for participants, such as enjoyment and social connectedness, which facilitated ongoing attendance and practice. Also key to facilitating practice (during and after the intervention) were suitability of the classes for those with health conditions, practising with a group and qualities of the yoga teacher. Home practice was supported by course materials (manual, videos), as well as the teaching of techniques for everyday application that offered immediate benefits, such as breathing practices. Follow-up questionnaires revealed a key challenge was continuation of practice once the intervention had finished, with the structure of a class important in supporting practice. Conclusions Yoga4Health was a highly acceptable intervention to services users, which brought a range of biopsychosocial improvements, suggesting yoga is an appropriate intervention to offer on social prescription

Preliminary analysis of performance and loads data from the 2-megawatt mod-1 wind turbine generator

Preliminary test data on output power versus wind speed, rotor blade loads, system dynamic behavior, and start-stop characteristics on the Mod-1 wind turbine generator are presented. These data were analyzed statistically and are compared with design predictions of system performance and loads. To date, the Mod-1 wind turbine generator has produced up to 1.5 MW of power, with a measured power versus wind speed curve which agrees closely with design. Blade loads were measured at wind speeds up to 14 m/s and also during rapid shutdowns. Peak transient loads during the most severe shutdowns are less than the design limit loads. On the inboard blade sections, fatigue loads are approximately equal to the design cyclic loads. On the outboard blade sections, however, measured cyclic loads are significantly larger than design values, but they do not appear to exceed fatigue allowable loads as yet