5,872 research outputs found
Sensitivity of predicted bioaerosol exposure from open windrow composting facilities to ADMS dispersion model parameters
Bioaerosols are released in elevated quantities from composting facilities and are associated with negative health effects, although dose-response relationships are not well understood, and require improved exposure classification. Dispersion modelling has great potential to improve exposure classification, but has not yet been extensively used or validated in this context. We present a sensitivity analysis of the ADMS dispersion model specific to input parameter ranges relevant to bioaerosol emissions from open windrow composting. This analysis provides an aid for model calibration by prioritising parameter adjustment and targeting independent parameter estimation. Results showed that predicted exposure was most sensitive to the wet and dry deposition modules and the majority of parameters relating to emission source characteristics, including pollutant emission velocity, source geometry and source height. This research improves understanding of the accuracy of model input data required to provide more reliable exposure predictions
Linking discrete event simulation models using HLA
The increasing usage of discrete event simulation packages for modeling and analyzing manufacturing and logistics has led to a need for connecting simulation models together at runtime. One such methodology for linking discrete event simulation models together has been developed for this research and this paper demonstrates the usage of this linking method. A unified simulation model is developed from two submodels developed using different simulation packages. <br /
Accurate OH maser positions II. the Galactic Center region
We present high spatial resolution observations of ground-state OH masers,
achieved using the Australia Telescope Compact Array (ATCA). These observations
were conducted towards 171 pointing centres, where OH maser candidates were
identified previously in the Southern Parkes Large-Area Survey in Hydroxyl
(SPLASH) towards the Galactic Center region, between Galactic longitudes of
and and Galactic latitudes of and
. We detect maser emission towards 162 target fields and suggest
that 6 out of 9 non-detections are due to intrinsic variability. Due to the
superior spatial resolution of the follow-up ATCA observations, we have
identified 356 OH maser sites in the 162 of the target fields with maser
detections. Almost half (161 of 356) of these maser sites have been detected
for the first time in these observations. After comparing the positions of
these 356 maser sites to the literature, we find that 269 (76\%) sites are
associated with evolved stars (two of which are planetary nebulae), 31 (9\%)
are associated with star formation, four are associated with supernova remnants
and we were unable to determine the origin of the remaining 52 (15\%) sites.
Unlike the pilot region (\citealt{Qie2016a}), the infrared colors of evolved
star sites with symmetric maser profiles in the 1612 MHz transition do not show
obvious differences compared with those of evolved star sites with asymmetric
maser profiles.Comment: 24 pages, 12 figures, accepted by ApJ
Antegrade Chronic Total Occlusion Strategies: A Technical Focus for 2020
Chronic total occlusions (CTOs) are common in patients with ischaemic heart disease. In many countries, patients with CTOs are underserved by percutaneous coronary intervention (PCI). One of the barriers to CTO PCI is the technical challenges of these procedures. Improvements in technique and dedicated devices for CTO PCI, combined with advances in procedural strategy, have resulted in a dramatic increase in procedural success and outcomes. Antegrade wiring (AW) is the preferred initial strategy in short CTOs, where the proximal cap and course of the vessel is understood. For many longer, more complex occlusions, AW has a low probability of success. Dissection and re-entry techniques allow longer CTOs and those with ambiguous anatomy to be crossed safely and efficiently, and CTO operators must also be familiar with these strategies. The CrossBoss and Stingray system is currently the primary targeted re-entry device used during antegrade dissection and re-entry (ADR), and there continues to be an evolution in its use to increase procedural efficiency. In contrast to older ADR techniques, targeted re-entry allows preservation of important side-branches, and there is no difference in outcomes compared to intraplaque stenting
Direct Observation of Dynamic Symmetry Breaking above Room Temperature in Methylammonium Lead Iodide Perovskite
Lead halide perovskites such as methylammonium lead triiodide (MAPI) have
outstanding optical and electronic properties for photovoltaic applications,
yet a full understanding of how this solution processable material works so
well is currently missing. Previous research has revealed that MAPI possesses
multiple forms of static disorder regardless of preparation method, which is
surprising in light of its excellent performance. Using high energy resolution
inelastic X-ray (HERIX) scattering, we measure phonon dispersions in MAPI and
find direct evidence for another form of disorder in single crystals: large
amplitude anharmonic zone-edge rotational instabilities of the PbI_6 octahedra
that persist to room temperature and above, left over from structural phase
transitions that take place tens to hundreds of degrees below. Phonon
calculations show that the orientations of the methylammonium couple strongly
and cooperatively to these modes. The result is a non-centrosymmetric,
instantaneous local structure, which we observe in atomic pair distribution
function (PDF) measurements. This local symmetry breaking is unobservable by
Bragg diffraction, but can explain key material properties such as the
structural phase sequence, ultra low thermal transport, and large minority
charge carrier lifetimes despite moderate carrier mobility.Comment: 30 pages, 11 figure
A national study of plasma use in critical care: clinical indications, dose and effect on prothrombin time
Chemical complexity in protoplanetary disks in the era of ALMA and Rosetta
Comets provide a unique insight into the molecular composition and complexity of the material in the primordial solar nebula. Recent results from the Rosetta mission, currently monitoring comet 67P/Churyumov-Gerasimenko in situ, and ALMA (the Atacama Large Millimeter/submillimeter Array) have demonstrated a tantalising link between the chemical complexity now confirmed in disks (via the detection of gas-phase cf.CH3CN Öberg et al. [13]) and that confirmed on the surface of 67P (Goesmann et al. [3]), raising questions concerning the chemical origin of such species (cloud or inheritance versus disk synthesis). Results from an astrochemical model of a protoplanetary disk are presented in which complex chemistry is included and in which it is assumed that simple ices only are inherited from the parent molecular cloud. The model results show good agreement with the abundances of several COMs observed on the surface of 67P with Philae/COSAC. Cosmic-ray and X-ray-induced photoprocessing of predominantly simple ices inherited by the protoplanetary disk is sufficient to generate a chemical complexity similar to that observed in comets. This indicates that the icy COMs detected on the surface of 67P may have a disk origin. The results also show that gas-phase cf.CH3CN is abundant in the inner warm disk atmosphere where hot gas-phase chemistry dominates and potentially erases the ice chemical signature. Hence, cf.CH3CN may not be an unambiguous tracer of the complex organic ice reservoir. However, a better understanding of the hot gas-phase chemistry of cf.CH3CN is needed to confirm this preliminary conclusion
Evaluation of a group acceptance commitment therapy intervention for people with knee or hip osteoarthritis: a pilot randomized controlled trial
Objectives: The aim was to evaluate an Acceptance Commitment Therapy (ACT) intervention for people with knee or hip osteoarthritis; a related aim was to compare treatment effects from Rasch-transformed and standard scales. Methods: Participants were recruited from a research database and outpatient rheumatology and orthopaedic clinics at two hospitals. Eligible participants were randomly allocated to either intervention or usual care. Intervention comprised six-sessions of group ACT. Outcomes were assessed two and four months after randomisation. Rasch-transformed and standard self-report measures were compared. Qualitative interviews also explored the acceptability of the intervention. Results: Of 8 people assessed for eligibility, 31 (36%) were randomised. The main reason for non-randomisation was that participants received surgery. Of the 16 participants randomised to intervention, 64% completed ≥50% of the scheduled group sessions. Follow-up data was complete for 84% participants at two months and 68% at four months. Outcome analysis demonstrated important differences between the Rasch-transformed and standard scales. There were significant differences between the groups in pain. Qualitative interviews with 7 participants suggested the intervention was acceptable. Conclusions: ACT for osteoarthritis is likely to be an acceptable treatment option for people with osteoarthritis. Progress to a definitive trial is warranted. Rasch-transformed outcome scales are preferable in clinical trials where possible
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