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Validated prediction of weld residual stresses in austenitic steel pipe girth welds before and after thermal ageing, part 1: Mock-up manufacture, residual stress measurements, and materials characterisation
A series of engineering-scale multi-pass pipe girth weld mock-ups were manufactured using conventional manual metal arc techniques from Esshete 1250 austenitic steel. They were characterised in detail, in order to provide validation benchmarks for finite element prediction of weld residual stresses. The fabrication sequence comprised initial solution heat treatment and quenching, manufacture of five closely spaced girth welds in a single assembly, and then separation into five individual weldments. Detailed welding records were kept, to allow subsequent calibration of weld heat source models. Residual stresses were measured using diverse methods (incremental deep hole drilling and the contour method), in both the as-welded condition and after thermal ageing at 650 °C. The measurements showed good agreement, providing reliable validation targets for predicted residual stresses in both states. Detailed mechanical property characterisation was performed on both parent material and weld metal, comprising monotonic and isothermal cyclic testing over a range of temperatures from ambient up to 1000 °C. The test data were used to derive a range of Lemaitre-Chaboche mixed isotropic-kinematic model parameter sets for use in finite element simulation. These welds and their supporting characterisation comprise a reliable benchmark for weld residual stress simulation in an engineering-scale weldment
Prevalence of Injuries Among Medicaid Enrolled Infants Prior to Child Abuse and Neglect
Prior research has identified common injuries among children who experience child maltreatment; however, most of this work has focused on inpatient settings and has excluded many cases of neglect. This study examines the prevalence of injuries that occur prior to a diagnosis of child maltreatment, as well as the proportion of children with well-child visits prior to the injury and child maltreatment diagnosis. Based on a secondary analysis of Medicaid data from four states, we found that among infants with 12 months of continuous enrollment (N = 4817), 30.6% of those diagnosed with maltreatment were previously diagnosed with an injury. Among infants diagnosed with child maltreatment, 88.4% had at least one well-child visit prior to the maltreatment diagnosis. Among children with a maltreatment diagnosis and a prior injury, 84% had at least one well-child visit preceding the injury. These results indicate that most children had at least one well-child visit prior to being diagnosed with child maltreatment or an injury, indicating opportunities for prevention
A preliminary investigation of the molten salt mediated synthesis of Gd2TiO5 âstuffedâ pyrochlore
Refractory âstuffedâ pyrochlores such as Gd2TiO5 are of interest for nuclear applications, including as matrices for actinide disposition and as neutron absorbers in control rods. Here, we report the results of a preliminary comparative investigation of the synthesis of Gd2TiO5 by molten salt and conventional solid-state synthesis. We show that synthesis of Gd2TiO5 proceeds from the pyrochlore phase Gd2Ti2O7 which is first formed as a kinetic product. Molten salt synthesis afforded single phase Gd2TiO5 at 1300 °C in 2 h, via a template growth mechanism, and is effective for the synthesis of these refractory materials. This work demonstrates molten salt mediated synthesis of âstuffedâ pyrochlore for the first time
Harmonious Healthcare Teams: What Healthcare Professionals Can and Cannot Learn from Chamber Musicians
Background: As healthcare becomes increasingly team based, we need new ways of educating trainees to be collaborative team members. One approach is to look to other professions that have developed highly effective ways of collaborating. Doctors have already turned to musicians for specific lessons; however, as of yet, there has been little empirical study of the ways that musicians interact in ensembles, or analysis of how this might provide insights for healthcare. Our hypothesis is that healthcare teams might learn from understanding collaborative practices of chamber musicians.Methods and Findings: We undertook an exploratory study of professional musicians playing in non-conducted ensembles. We used semi-structured interviews to explore factors the musicians considered important for effective group function. The interviews were transcribed and coded thematically. We identified three prominent themes that have relevance for healthcare teams.Conclusions: The highly individual nature of each musical groupâs identity suggests that a focus on generic interprofessional education skills development may be insufficient. Furthermore, musiciansâ understanding of the fundamental role of non-melodic parts provides the possibility of more nuanced leadership models. Finally, essential differences between musiciansâ interactions in rehearsals and performances highlight the importance of varied forms of group interactions
Trends in unintentional polysubstance overdose deaths and individual and community correlates of polysubstance overdose, North Carolina, 2009-2018
Background: Polysubstance involvement is increasing among fatal drug overdoses. However, little is known about the epidemiology of polysubstance drug overdoses. This paper describes emerging trends in unintentional polysubstance overdose deaths in North Carolina (NC) and examines associations with individual and community factors. Methods: Using 2009â2018 NC death certificate data, we identified unintentional drug overdose deaths and commonly involved substances (opioids, stimulants, benzodiazepines, alcohol, and antiepileptics). We examined polysubstance combinations, comparing opioid and non-opioid involved deaths. We examined individual level correlates from death certificate data and community level correlates from the American Community Survey and Robert Wood Johnson Foundation County Health Rankings to quantify associations. Results: From 2009â2018, 53 % of opioid and 19 % of non-opioid overdose deaths involved multiple substances. During this period, polysubstance overdose death increased dramatically, from 2.9 to 12.1 per 100,000 persons, with the greatest increases among drug combinations involving stimulants. The most common polysubstance combinations were: opioids and stimulants (12.1 % of overdose deaths); opioids and benzodiazepines (9.0 %); opioids and alcohol (5.1 %); opioids, stimulants, and benzodiazepines (3.1 %); and opioids, benzodiazepines, and antiepileptics (2.2 %). Compared to overdoses involving opioids alone, overdoses involving combinations of opioids, stimulants, and benzodiazepines involved younger individuals (53.7 % in 15â34 years of age vs. 40.7 %). Men comprised two-thirds of overdoses involving opioids alone, however, overdoses involving opioids, benzodiazepines, and antiepileptics were predominantly among women (60.6 %). Conclusions: Polysubstance involvement has increased among overdose deaths in NC. These findings can be used to inform public health interventions addressing polysubstance deaths and associated individual and community level factors
Universal Correlations of Coulomb Blockade Conductance Peaks and the Rotation Scaling in Quantum Dots
We show that the parametric correlations of the conductance peak amplitudes
of a chaotic or weakly disordered quantum dot in the Coulomb blockade regime
become universal upon an appropriate scaling of the parameter. We compute the
universal forms of this correlator for both cases of conserved and broken time
reversal symmetry. For a symmetric dot the correlator is independent of the
details in each lead such as the number of channels and their correlation. We
derive a new scaling, which we call the rotation scaling, that can be computed
directly from the dot's eigenfunction rotation rate or alternatively from the
conductance peak heights, and therefore does not require knowledge of the
spectrum of the dot. The relation of the rotation scaling to the level velocity
scaling is discussed. The exact analytic form of the conductance peak
correlator is derived at short distances. We also calculate the universal
distributions of the average level width velocity for various values of the
scaled parameter. The universality is illustrated in an Anderson model of a
disordered dot.Comment: 35 pages, RevTex, 6 Postscript figure
Search for displaced vertices arising from decays of new heavy particles in 7 TeV pp collisions at ATLAS
We present the results of a search for new, heavy particles that decay at a
significant distance from their production point into a final state containing
charged hadrons in association with a high-momentum muon. The search is
conducted in a pp-collision data sample with a center-of-mass energy of 7 TeV
and an integrated luminosity of 33 pb^-1 collected in 2010 by the ATLAS
detector operating at the Large Hadron Collider. Production of such particles
is expected in various scenarios of physics beyond the standard model. We
observe no signal and place limits on the production cross-section of
supersymmetric particles in an R-parity-violating scenario as a function of the
neutralino lifetime. Limits are presented for different squark and neutralino
masses, enabling extension of the limits to a variety of other models.Comment: 8 pages plus author list (20 pages total), 8 figures, 1 table, final
version to appear in Physics Letters
Measurement of the polarisation of W bosons produced with large transverse momentum in pp collisions at sqrt(s) = 7 TeV with the ATLAS experiment
This paper describes an analysis of the angular distribution of W->enu and
W->munu decays, using data from pp collisions at sqrt(s) = 7 TeV recorded with
the ATLAS detector at the LHC in 2010, corresponding to an integrated
luminosity of about 35 pb^-1. Using the decay lepton transverse momentum and
the missing transverse energy, the W decay angular distribution projected onto
the transverse plane is obtained and analysed in terms of helicity fractions
f0, fL and fR over two ranges of W transverse momentum (ptw): 35 < ptw < 50 GeV
and ptw > 50 GeV. Good agreement is found with theoretical predictions. For ptw
> 50 GeV, the values of f0 and fL-fR, averaged over charge and lepton flavour,
are measured to be : f0 = 0.127 +/- 0.030 +/- 0.108 and fL-fR = 0.252 +/- 0.017
+/- 0.030, where the first uncertainties are statistical, and the second
include all systematic effects.Comment: 19 pages plus author list (34 pages total), 9 figures, 11 tables,
revised author list, matches European Journal of Physics C versio
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