38,510 research outputs found
Thermodynamic property measurements in reflected shock air plasmas at 12,000 - 16,000 K
Reflected shock air plasma thermodynamic properties at 12,000 to 16,000 deg
An evlauation of the three-dimensional split-film anemometer for measurements of atmospheric turbulence
A three-dimensional split-film anemometer was tested in turbulent, as well as in nonturbulent flow downstream from a wind tunnel turbulence grid. The data obtained with this probe in the turbulence behind the grid, indicated that the measured turbulence intensities were somewhat lower than the intensity measured with the conventional hot-wire anemometry; a result of the finite dimensions of the sensor arrays. The probe yaw angle was determined to be accurate within three degrees. Statistical averages, determined by mean-wind direction and vertical and lateral directions were computed on the basis of the probe yaw angle
Chemical abundance study of two strongly s-process enriched post-AGB stars in the LMC: J051213.81-693537.1 and J051848.86-700246.9
Context: This paper is part of a larger project in which we study the
chemical abundances of extra-galactic post-AGB stars with the ultimate goal of
improving our knowledge of the poorly understood AGB third dredge-up mixing
processes and s-process nucleosynthesis. Aims: In this paper, we study two
carefully selected post-AGB stars in the LMC. The combination of favourable
atmospheric parameters for detailed abundance studies and their known distances
make these objects ideal probes of the internal AGB third dredge-up and
s-process nucleosynthesis in that they provide observational constraints for
theoretical AGB models. Methods: We use high-resolution optical UVES spectra to
determine accurate stellar parameters and perform detailed elemental abundance
studies. Additionally, we use available photometric data to construct SEDs for
reddening and luminosity determinations. We then estimate initial masses from
theoretical post-AGB tracks. Results: Both stars show extreme s-process
enrichment associated with relatively low C/O ratios of about 1.3. We could
only derive upper limits of the lead (Pb) abundance which indicate no strong Pb
overabundances with respect to other s-elements. Comparison with theoretical
post-AGB evolutionary tracks in the HR-diagram reveals that both stars have low
initial masses between 1.0 and 1.5 Msun. Conclusion: This study adds to the
results obtained so far on a very limited number of s-process enriched post-AGB
stars in the Magellanic Clouds. We find an increasing discrepancy between
observed and predicted Pb abundances towards lower metallicities for all
studied Magellanic Cloud post-AGB stars found so far, as well as moderate C/O
ratios. We find that all s-process rich post-AGB stars in the LMC and SMC
studied so far, cluster in the same region of the HR-diagram and are associated
with low-mass stars with a low metallicity on average.Comment: 11 pages, 14 figure
Chemical abundance study of two strongly s-process enriched post-AGB stars in the LMC: J051213.81-693537.1 and J051848.86-700246.9
Context: This paper is part of a larger project in which we study the
chemical abundances of extra-galactic post-AGB stars with the ultimate goal of
improving our knowledge of the poorly understood AGB third dredge-up mixing
processes and s-process nucleosynthesis. Aims: In this paper, we study two
carefully selected post-AGB stars in the LMC. The combination of favourable
atmospheric parameters for detailed abundance studies and their known distances
make these objects ideal probes of the internal AGB third dredge-up and
s-process nucleosynthesis in that they provide observational constraints for
theoretical AGB models. Methods: We use high-resolution optical UVES spectra to
determine accurate stellar parameters and perform detailed elemental abundance
studies. Additionally, we use available photometric data to construct SEDs for
reddening and luminosity determinations. We then estimate initial masses from
theoretical post-AGB tracks. Results: Both stars show extreme s-process
enrichment associated with relatively low C/O ratios of about 1.3. We could
only derive upper limits of the lead (Pb) abundance which indicate no strong Pb
overabundances with respect to other s-elements. Comparison with theoretical
post-AGB evolutionary tracks in the HR-diagram reveals that both stars have low
initial masses between 1.0 and 1.5 Msun. Conclusion: This study adds to the
results obtained so far on a very limited number of s-process enriched post-AGB
stars in the Magellanic Clouds. We find an increasing discrepancy between
observed and predicted Pb abundances towards lower metallicities for all
studied Magellanic Cloud post-AGB stars found so far, as well as moderate C/O
ratios. We find that all s-process rich post-AGB stars in the LMC and SMC
studied so far, cluster in the same region of the HR-diagram and are associated
with low-mass stars with a low metallicity on average.Comment: 11 pages, 14 figure
Resonant Scattering of Emission Lines in Coronal Loops: Effects on Image Morphology and Line Ratios
We have investigated the effects of resonant scattering of emission lines on
the image morphology and intensity from coronal loop structures. It has
previously been shown that line of sight effects in optically thin line
emission can yield loop images that appear uniformly bright at one viewing
angle, but show ``looptop sources'' at other viewing angles. For optically
thick loops where multiple resonant scattering is important, we use a 3D Monte
Carlo radiation transfer code. Our simulations show that the intensity
variation across the image is more uniform than the optically thin simulation
and, depending on viewing angle, the intensity may be lower or higher than that
predicted from optically thin simulations due to scattering out of or into the
line of sight.Comment: Accepted for publication in Ap
Comparison of Allen Carr's Easyway programme with a specialist behavioural and pharmacological smoking cessation support service: a randomized controlled trial.
BACKGROUND AND AIMS: A combination of behavioural and pharmacological support is judged to be the optimal approach for assisting smoking cessation. Allen Carr's Easyway (ACE) is a single-session pharmacotherapy-free programme that has been in operation internationally for 38Â years. We compared the effectiveness of ACE with specialist behavioural and pharmacological support delivered to the national standard in England. DESIGN: A two-arm, parallel-group, single-blind, randomized controlled trial. SETTING: London, UK, between February 2017 and May 2018. PARTICIPANTS: A total of 620 participants (310 in ACE and 310 in the combined behavioural and pharmacological support condition) were included in the analysis. Adult (â„ 18Â years) smokers wanting to quit were randomized in a 1Â :Â 1 ratio. Mean age for the total sample was 40.8Â years, with 53.4% being male. Participant baseline characteristics (ethnicity, educational level, number of previous quit attempts, nicotine dependence) were evenly balanced between treatment groups. INTERVENTION AND COMPARATOR: The intervention was the ACE method of stopping smoking. This centres on a 4.5-6-hour session of group-based support, alongside subsequent text messages and top-up sessions if needed. It aims to make it easy to stop smoking by convincing smokers that smoking provides no benefits for them. The comparator was a specialist stop smoking service (SSS) providing behavioural and pharmacological support in accordance with national standards. MEASUREMENTS: The primary outcome was self-reported continuous abstinence for 26Â weeks from the quit/quit re-set date verified by exhaled breath carbon monoxide measurement <Â 10Â parts per million (p.p.m.). Primary analysis was by intention to treat. Secondary outcomes were: use of pharmacotherapy, adverse events and continuous abstinence up to 4 and 12Â weeks. FINDINGS: A total of 468 participants attended treatment (255 ACE versus 213 SSS, PÂ <Â 0.05). Of those who did attend treatment, 100 completed 6-month measures (23.7% ACE versus 20.7% SSS). Continuous abstinence to 26Â weeks was 19.4% (60 of 310) in the ACE intervention and 14.8% (46 of 310) in the SSS intervention [risk difference for ACE versus SSS 4.5% (95% confidence interval (CI) =Â -1.4 to 10.4%, odds ratio (OR)Â =Â 1.38)]. The Bayes factor for superiority of the ACE condition was 1.24. CONCLUSION: There was no clear evidence of a difference in the efficacies of the Allen Carr's Easyway (ACE) and specialist smoking cessation support involving behavioural support and pharmacotherapy
A review of the development of the education service in the borough of Chesterfield 1944-1967
The thesis examines the growth of the Education Service in the Excepted District of the Borough of chesterfield from 1944 to I967. The negotiations leading to the granting of Excepted District status and the formulation of the Scheme of Delegation are discussed, together with the establishment of Managing and Governing bodies of schools and the production of the Development plan for the Borough. The Major and Minor works building programmes are examined and related to the proposals of the Development plan. The evolution of a transfer procedure is described end an analysis is made of the philosophy of Secondary Education maintained by the Borough Education Officer of the day which gave rise to a system of Secondary Schools which attracted interest and acknowledgement at national level and of the factors which caused dissatisfaction with the system in the late 1950's. The resulting discussion leading towards the reorganisation of Secondary Education and the effect of Circulars 10/65 and 10/66 on the decisions of the Council are also examined. The growth of Special Services, Further Education and the Youth Service and the Library Service within the functions delegated by the Scheme of Divisional Administration is outlined. The introduction of i.t.a. and French in the Primary Schools is included in the survey. The successful growth of the service in all its aspects is shown to be a justification for the belief expressed in 1944 that the small Authority of Chesterfield was well able to manage its own affairs within the Scheme of Delegation. The influence of the Borough's geographical position within N.E. Derbyshire, together with the willingness of the Local Education Authority to support bids for the provision of various establishments serving the Borough and N.E. Derbyshire, thus augmenting the development of the Borough Education Service, is analysed
Robot-Mediated Interviews with Children : What do potential users think?
Luke Wood, Hagen Lehmann, Kerstin Dautenhahn, Ben Robins, Austen Rayner, and Dag Syrdal, âRobot-Mediated Interviews with Children: What do potential users think?â, paper presented at the 50th Annual Convention of the Society for the Study of Artificial Intelligence and the Simulation of Behaviour, 1 April 2014 â 4 April 2014, London, UK.When police officers are conducting interviews with children, some of the disclosures can be quite shocking. This can make it difficult for an officer to maintain their composure without subtly indicating their shock to the child, which can in turn impede the information acquisition process. Using a robotic interviewer could eliminate this problem as the behaviours and expressions of the robot can be consciously controlled. To date research investigating the potential of Robot-Mediated Interviews has focused on establishing whether children will respond to robots in an interview scenario and if so how well. The results of these studies indicate that children will talk to a robot in an interview scenario in a similar way to which they talk to a human interviewer. However, in order to test if this approach would work in a real world setting, it is important to establish what the experts (e.g. specialist child interviewers) would require from the system. To determine the needs of the users we conducted a user panel with a group of potential real world users to gather their views of our current system and find out what they would require for the system to be useful to them. The user group we worked with consisted of specialist child protection police officers based in the UK. The findings from this panel suggest that a Robot-Mediated Interviewing system would need to be more flexible than our current system in order to respond to unpredictable situations and paths of investigation. This paper gives an insight into what real world users would need from a Robot-Mediated Interviewing system
Pairing-excitation versus intruder states in 68Ni and 90Zr
A discussion on the nature of the 0+ states in 68Ni (Z=28, N=40) is presented
and a comparison is made with its valence counterpart 90Zr (Z=40, N=50).
Evidence is given for a 0+ proton intruder state at only ~2.2 MeV excitation
energy in 68Ni, while the analogous neutron intruder states in 90Zr reside at
4126 keV and 5441 keV. The application of a shell-model description of 0+
intruder states reveals that many pair-scattered neutrons across N=40 have to
be involved to explain the low excitation energy of the proton-intruder
configuration in 68Ni.Comment: 10 pages, 2 figures, 1 tabl
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