17,176 research outputs found
Development of a magneforming process for the fabrication of thin-wall tungsten cylinders final report
Magneforming process - high energy rate metal forming technique for fabrication of thin wall tungsten cylinder
Developing E-cigarette friendly smoking cessation services in England: staff perspectives
This is the final version of the article. Available from BioMed Central via the DOI in this record.BACKGROUND: Public health leadership in England has taken a distinctive international stance by identifying the potential public health benefit of e-cigarettes for smoking cessation. This includes the development of a ground-breaking set of national guidelines for developing e-cigarette friendly stop smoking services. However, little is known about the views of staff engaged within these services and whether or how such services are becoming e-cigarette friendly. This study aimed to investigate the uptake and usage of e-cigarette guidance, from the perspective of those enacting tobacco cessation interventions 'on the ground'. METHODS: Qualitative semi-structured interviews were conducted with 25 cessation service staff, including advisors (n = 15), managers (n = 5) and commissioners (n = 5) from eight different services in the South-West of England, UK. A thematic analysis of the transcripts was conducted using NVivo software. RESULTS: Although some stop smoking services labelled themselves e-cigarette friendly, there was no consensus over what this should entail. For some, this meant active engagement, such as working with local vape shops, and in the case of one service, offering e-cigarettes through a voucher scheme to disadvantaged groups. For others, an e-cigarette friendly service was conceptualized in a passive sense, as one which welcomed service users using e-cigarettes. Many services did not use the 'e-cigarette friendly' claim in their branding or promotional material. Several discursive themes underlay differing staff attitudes. Those more reluctant to engage framed this in terms of their 'duty of care', with concerns focusing on the addictiveness of nicotine, lack of medically licensed product and ongoing scientific controversy. Those motivated to engage drew on a discourse of social justice goals and 'doing things differently' in relation to lower socio-economic status smokers, those with mental health issues and other vulnerable groups. Strong public health leadership was also identified as a key factor in changing staff attitudes towards e-cigarettes. CONCLUSIONS: On-the-ground enactment of e-cigarette friendly services is varied as well as reflective of the wider policy and regulatory environment. Although the context of English stop smoking services is one of austerity and change, there are opportunities for active engagement with e-cigarettes to achieve overall cessation goals. For this to occur, training, policy consistency and sharing best practice are needed.This study was funded by Cancer Research UK, Tobacco Advisory Group (TAG)
Hysteresis multicycles in nanomagnet arrays
We predict two new physical effects in arrays of single-domain nanomagnets by
performing simulations using a realistic model Hamiltonian and physical
parameters. First, we find hysteretic multicycles for such nanomagnets. The
simulation uses continuous spin dynamics through the Landau-Lifshitz-Gilbert
(LLG) equation. In some regions of parameter space, the probability of finding
a multicycle is as high as ~0.6. We find that systems with larger and more
anisotropic nanomagnets tend to display more multicycles. This result
demonstrates the importance of disorder and frustration for multicycle
behavior. We also show that there is a fundamental difference between the more
realistic vector LLG equation and scalar models of hysteresis, such as Ising
models. In the latter case, spin and external field inversion symmetry is
obeyed but in the former it is destroyed by the dynamics, with important
experimental implications.Comment: 7 pages, 2 figure
Untersuchungen zum Gehalt an ME und praecaecal verdaulichen Aminosäuren aus einem Gemisch thermisch behandelter Körnerleguminosen (LEGUMI-therm®) beim Broiler
The objective of this study was to assess the effect of heating a mixture of grain legumes based on sweet lupins, faba beans, and peas (1:1:1, toasted “LEGUMItherm ®”; untreated: “LEGUMI-mix”) on the content of metabolisable energy (ME) and precaecal digestible (pc) amino acids for broilers. The mean of amino acid digestibility of LEGUMI-mix and LEGUMI-therm was 88 and 87 %. The ME content of the mixture ranged between 11.9 (LEGUMI-therm) and 12.1 MJ/kg DM (LEGUMI-mix). Both parameters were unaffected by heating
A necklace of Wulff shapes
In a probabilistic model of a film over a disordered substrate, Monte-Carlo
simulations show that the film hangs from peaks of the substrate. The film
profile is well approximated by a necklace of Wulff shapes. Such a necklace can
be obtained as the infimum of a collection of Wulff shapes resting on the
substrate. When the random substrate is given by iid heights with exponential
distribution, we prove estimates on the probability density of the resulting
peaks, at small density
Trust, regulatory processes and NICE decision-making: Appraising cost-effectiveness models through appraising people and systems.
This article presents an ethnographic study of regulatory decision-making regarding the cost-effectiveness of expensive medicines at the National Institute for Health and Care Excellence (NICE) in England. We explored trust as one important mechanism by which problems of complexity and uncertainty were resolved. Existing studies note the salience of trust for regulatory decisions, by which the appraisal of people becomes a proxy for appraising technologies themselves. Although such (dis)trust in manufacturers was one important influence, we describe a more intricate web of (dis)trust relations also involving various expert advisors, fellow committee members and committee Chairs. Within these complex chains of relations, we found examples of both more blind-acquiescent and more critical-investigative forms of trust as well as, at times, pronounced distrust. Difficulties in overcoming uncertainty through other means obliged trust in some contexts, although not in others. (Dis)trust was constructed through inferences involving abstract systems alongside actors’ oral and written presentations-of-self. Systemic features and ‘forced options’ to trust indicate potential insidious processes of regulatory capture
Counts and Sizes of Galaxies in the Hubble Deep Field - South: Implications for the Next Generation Space Telescope
Science objectives for the Next Generation Space Telescope (NGST) include a
large component of galaxy surveys, both imaging and spectroscopy. The Hubble
Deep Field datasets include the deepest observations ever made in the
ultraviolet, optical and near infrared, reaching depths comparable to that
expected for NGST spectroscopy. We present the source counts, galaxy sizes and
isophotal filling factors of the HDF-South images. The observed integrated
galaxy counts reach >500 galaxies per square arcminute at AB<30. We extend
these counts to faint levels in the infrared using models. The trend previously
seen that fainter galaxies are smaller, continues to AB=29 in the high
resolution HDF-S STIS image, where galaxies have a typical half-light radius of
0.1 arcseconds. Extensive Monte Carlo simulations show that the small measured
sizes are not due to selection effects until >29mag. Using the HDF-S NICMOS
image, we show that galaxies are smaller in the near infrared than they are in
the optical. We analyze the isophotal filling factor of the HDF-S STIS image,
and show that this image is mostly empty sky even at the limits of galaxy
detection, a conclusion we expect to hold true for NGST spectroscopy. At the
surface brightness limits expected for NGST imaging, however, about a quarter
of the sky is occupied by the outer isophotes of AB<30 galaxies. We discuss the
implications of these data on several design concepts of the NGST near-infrared
spectrograph. We compare the effects of resolution and the confusion limit of
various designs, as well as the multiplexing advantages of either multi-object
or full-field spectroscopy. We argue that the optimal choice for NGST
spectroscopy of high redshift galaxies is a multi-object spectrograph (MOS)
with target selection by a micro electro mechanical system (MEMS) device.Comment: 27 pages including 10 figures, accepted for publication in the
Astronomical Journal, June 2000, abridged abstrac
Superfluidity of spin-polarized 6Li
We study the prospects for observing superfluidity in a spin-polarized atomic
gas of Li atoms, using state-of-the-art interatomic potentials. We
determine the spinodal line and show that a BCS transition to the superfluid
state can indeed occur in the (meta)stable region of the phase diagram if the
densities are sufficiently low. Moreover, for a total density of
, which still fulfills this requirement, we find a critical
temperature of only . We also discuss the stability of the gas due to
exchange and dipolar relaxation and conclude that the prospects for observing
superfluidity in a magnetically trapped atomic Li gas are particularly
promising for magnetic bias fields larger than .Comment: 4 pages of ReVTeX and 2 uuencoded figures. Submitted for publication
in Physical Review Letter
Strong signatures of radiation reaction below the radiation dominated regime
The influence of radiation reaction (RR) on multiphoton Thomson scattering by
an electron colliding head-on with a strong laser beam is investigated in a new
regime, in which the momentum transferred on average to the electron by the
laser pulse approximately compensates the one initially prepared. This
equilibrium is shown to be far more sensitive to the influence of RR than
previously studied scenarios. As a consequence RR can be experimentally
investigated with currently available laser systems and the underlying widely
discussed theoretical equations become testable for the first time.Comment: 4 pages, 3 figure
Detecting the Earliest Galaxies Through Two New Sources of 21cm Fluctuations
The first galaxies that formed at a redshift ~20-30 emitted continuum photons
with energies between the Lyman-alpha and Lyman limit wavelengths of hydrogen,
to which the neutral universe was transparent except at the Lyman-series
resonances. As these photons redshifted or scattered into the Lyman-alpha
resonance they coupled the spin temperature of the 21cm transition of hydrogen
to the gas temperature, allowing it to deviate from the microwave background
temperature. We show that the fluctuations in the radiation emitted by the
first galaxies produced strong fluctuations in the 21cm flux before the
Lyman-alpha coupling became saturated. The fluctuations were caused by biased
inhomogeneities in the density of galaxies, along with Poisson fluctuations in
the number of galaxies. Observing the power-spectra of these two sources would
probe the number density of the earliest galaxies and the typical mass of their
host dark matter halos. The enhanced amplitude of the 21cm fluctuations from
the era of Lyman-alpha coupling improves considerably the practical prospects
for their detection.Comment: 11 pages, 7 figures, ApJ, published. Normalization fixed in top
panels of Figures 4-
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