2,871 research outputs found
Morphology investigation on direct current pulsed gas tungsten arc welded additive layer manufactured Ti6Al4V alloy
The effects of pulsed gas tungsten arc weldingparameters on the morphology of
additive layer manufacturedTi6Al4V has been investigated in this study. Thepeak/
base current ratio and pulse frequency are found tohave no significant effect on
the refinement of prior betagrain size. However, it is found that the wire feed
ratehas a considerable effect on the prior beta grainrefinement at a given heat
input. This is due to the extrawire input being able to supply many
heterogeneousnucleation sites and also results in a negative temperaturegradient
in the front of the liquidus which blocks thecolumnar growth and changes the
columnar growth toequiaixal growth
Electronic Raman scattering in Magnetite, Spin vs. Charge gap
We report Raman scattering data of single crystals of magnetite (Fe3O4) with
Verwey transition temperatures (Tv) of 123 and 117K, respectively. Both single
crystals reveal broad electronic background extending up to 900 wavenumbers
(~110 meV). Redistribution of this background is observed when samples are
cooled below Tv. In particular, spectra of the low temperature phase show
diminished background below 300 wavenumbers followed by an enhancement of the
electronic background between 300 and 400 wavenumbers. To enhance the effect of
this background redistribution we divide the spectra just below the transition
by the spectra just above the transition. A resultant broad peak-like feature
is observed, centered at 370 wavenumbers (45 meV). The peak position of this
feature does not scale with the transition temperature. We discuss two
alternative assignments of this feature to a spin or charge gap in magnetite.Comment: 4 figures, 1 tabl
Project Energize: intervention development and 10 years of progress in preventing childhood obesity
Prevention of childhood obesity is a global priority. The school setting offers access to large numbers of children and the ability to provide supportive environments for quality physical activity and nutrition. This article describes Project Energize, a through-school physical activity and nutrition programme that celebrated its 10-year anniversary in 2015 so that it might serve as a model for similar practices, initiatives and policies elsewhere. The programme was envisaged and financed by the Waikato District Health Board of New Zealand in 2004 and delivered by Sport Waikato to 124 primary schools as a randomised controlled trial from 2005 to 2006. The programme has since expanded to include all 242 primary schools in the Waikato region and 70 schools in other regions, including 53,000 children. Ongoing evaluation and development of Project Energize has shown it to be sustainable (ongoing for >10 years), both effective (lower obesity, higher physical fitness) and cost effective (one health related cost quality adjusted life year between 30,000) and efficient ($45/child/year) as a childhood 'health' programme. The programme's unique community-based approach is inclusive of all children, serving a population that is 42 % Ma¯ori, the indigenous people of New Zealand. While the original nine healthy eating and seven quality physical activity goals have not changed, the delivery and assessment processes has been refined and the health service adapted over the 10 years of the programme existence, as well as adapted over time to other settings including early childhood education and schools in Cork in Ireland. Evaluation and research associated with the programme delivery and outcomes are ongoing. The dissemination of findings to politicians and collaboration with other service providers are both regarded as priorities
Symbolic Planning and Code Generation for Grounded Dialogue
Large language models (LLMs) excel at processing and generating both text and
code. However, LLMs have had limited applicability in grounded task-oriented
dialogue as they are difficult to steer toward task objectives and fail to
handle novel grounding. We present a modular and interpretable grounded
dialogue system that addresses these shortcomings by composing LLMs with a
symbolic planner and grounded code execution. Our system consists of a reader
and planner: the reader leverages an LLM to convert partner utterances into
executable code, calling functions that perform grounding. The translated
code's output is stored to track dialogue state, while a symbolic planner
determines the next appropriate response. We evaluate our system's performance
on the demanding OneCommon dialogue task, involving collaborative reference
resolution on abstract images of scattered dots. Our system substantially
outperforms the previous state-of-the-art, including improving task success in
human evaluations from 56% to 69% in the most challenging setting.Comment: Accepted to EMNLP 202
Corrosion and Passivation of Fe and FeN Films
The role of nitrogen in corrosion and passivation of thin Fe-N films was studied. Sputtered films with different levels of nitrogen were characterized for composition, conductivity, stress, and crystallinity. Corrosion and passivation of the films were evaluated by electrochemical measurements combined with in situ ellipsometry and ex situ x-ray photoelectron spectroscopy. The results indicate that in deaerated solutions the primary action of N is to reduce the catalytic activity of the surface for the hydrogen reaction and thereby reduce corrosion. In aerated solutions the corrosion rate increases with N content. Kinetics of the protective oxide formation as a function of potential, percent N, and the presence of borate buffer are discussed in detail. The work is relevant to the behavior of oxide-free Fe-N surfaces in contact with mild, nearly neutral electrolytes, such as could be used in fabrication of magnetic recording heads
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Quantification of ethyl acetate using FAIMS
The enjoyment of wine is based not only on its flavour but also its aroma. The presence of compounds, such as ethyl acetate, can add a desirable depth of body, richness and sweetness to a wine. However, if the levels exceed the human perception threshold (100 - 200 mg/l) an aroma similar to acetone becomes prevalent and the wine is regarded as spoilt.A study was undertaken to determine the concentration of ethyl acetate within wine using a Gas Chromatograph coupled with Field Asymmetric Ion Mobility Spectrometry (FAIMS).
The use of FAIMS (also known as Differential Mobility Spectrometry) as a selective detector has increasingly become prevalent within analytical science. There is now a vibrant community of researchers working with the technique and different commercial systems are readily available. Two such systems are the Tourist and Lonestar instruments available from Owlstone Ltd. The Owlstone systems are characterised by the sensor being a solid state device, which imposes constraints on operational parameters but also offers opportunities over comparable devices.
FAIMS technology requires the interaction of compounds both within the ionisation and separation region. To influence the interactions in these two regions studies were completed at elevated (compared to ambient) pressures and humidity. The study of ethyl acetate within wine provided an opportunity to investigate these effects and also provided a route for optimisation of the instrument for the study.
It was found, in contrast to a previously reported investigation, that increasing the pressure resulted in a greater resolution of compounds. A more complicated relationship was observed with respect to humidity, believed attributable to water being an important constituent of reactive and product ion formation. Additional effects due to the presence of co-solvents were observed and subsequently managed so as to provide increased sensitivity.
The quantification of ethyl acetate within wine was accomplished considerably below the human perception threshold providing the opportunity to better manage this multifarious compound throughout manufacture and the product lifecycle
Anti–Vascular Endothelial Growth Factor Drugs Compared With Panretinal Photocoagulation for the Treatment of Proliferative Diabetic Retinopathy: A Cost-Effectiveness Analysis
\ua9 2024Objectives: This study aimed to evaluate the cost-effectiveness of anti–vascular endothelial growth factor drugs (anti-VEGFs) compared with panretinal photocoagulation (PRP) for treating proliferative diabetic retinopathy (PDR) in the United Kingdom. Methods: A discrete event simulation model was developed, informed by individual participant data meta-analysis. The model captures treatment effects on best corrected visual acuity in both eyes, and the occurrence of diabetic macular edema and vitreous hemorrhage. The model also estimates the value of undertaking further research to resolve decision uncertainty. Results: Anti-VEGFs are unlikely to generate clinically meaningful benefits over PRP. The model predicted anti-VEGFs be more costly and similarly effective as PRP, generating 0.029 fewer quality-adjusted life-years at an additional cost of \ua33688, with a net health benefit of −0.214 at a \ua320 000 willingness-to-pay threshold. Scenario analysis results suggest that only under very select conditions may anti-VEGFs offer potential for cost-effective treatment of PDR. The consequences of loss to follow-up were an important driver of model outcomes. Conclusions: Anti-VEGFs are unlikely to be a cost-effective treatment for early PDR compared with PRP. Anti-VEGFs are generally associated with higher costs and similar health outcomes across various scenarios. Although anti-VEGFs were associated with lower diabetic macular edema rates, the number of cases avoided is insufficient to offset the additional treatment costs. Key uncertainties relate to the long-term comparative effectiveness of anti-VEGFs, particularly considering the real-world rates and consequences of treatment nonadherence. Further research on long-term visual acuity and rates of vision-threatening complications may be beneficial in resolving uncertainties
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