46 research outputs found

    Characterisation of selectively laser melted dissimilar alloys for remanufacturing applications: iconel 625 over cast iron

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    by Roshan SebastianM.Tech

    PredNet and Predictive Coding: A Critical Review

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    PredNet, a deep predictive coding network developed by Lotter et al., combines a biologically inspired architecture based on the propagation of prediction error with self-supervised representation learning in video. While the architecture has drawn a lot of attention and various extensions of the model exist, there is a lack of a critical analysis. We fill in the gap by evaluating PredNet both as an implementation of the predictive coding theory and as a self-supervised video prediction model using a challenging video action classification dataset. We design an extended model to test if conditioning future frame predictions on the action class of the video improves the model performance. We show that PredNet does not yet completely follow the principles of predictive coding. The proposed top-down conditioning leads to a performance gain on synthetic data, but does not scale up to the more complex real-world action classification dataset. Our analysis is aimed at guiding future research on similar architectures based on the predictive coding theory

    Developing Biocompatible Wide Temperature-Range Functional Herders for Rapid Oil Spill Response

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    The effect of oil spills in marine environment has resulted in huge negative environmental impacts and economic loss. The Deepwater Horizon oil spill of 2010 is the most recent, and the worst spill in the world, which affected more than 8000 kinds of marine organisms and cost around $65 Billion. Hence, it is imperative to have in place an effective and efficient oil spill recovery system. The research focuses on developing a chemical oil recovery method called oil herding. Herder is an amphiphilic oil-collecting agent, that is designed to spray around the oil spill areas and can retract oil slick from a thin layer to a thick mass, which is easier for further spill recovery. The application of oil herder lowers the air-water tension and causes retraction of the oil slick. The commercial oil herders like Silsurf A108 and Silsurf A004-D are effective, but their toxic impact to environment is undocumented, and they are chemically stable, which makes them remain on water body for a long period. The proposed project aims to develop an innovative oil herder from a natural plant-based product, Konjac. The base material used to develop the proposed oil herder konjac is derived from konjac root, commercially known as konjac glucomannan (KGM). KGM is a natural polysaccharide and has flexibility in functionalization. The easily functionalized hydroxyl groups in the KGM molecular structure allow hydrophobic tails to be attached to the hydrophilic backbone to form the surfactant-like structure. The functionalized KGM is demonstrated in this research to efficiently herd lighter oils like dodecane. KGM was found to have no Krafft temperature and that enables it to be effective in herding oil in cold waters. The applications of KGM based surfactants as dispersants or as agents aiding dispersants in oil spill mitigation is an area which augurs more research

    Hadrophilic Dark Sectors at the Forward Physics Facility

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    Models with light dark sector and dark matter particles motivate qualitatively new collider searches. Here we carry out a comprehensive study of hadrophilic models with U(1)B_B and U(1)B3Lτ_{B-3L_{\tau}} gauge bosons coupled to light dark matter. The new mediator particles in these models couple to quarks, but have suppressed couplings to leptons, providing a useful foil to the well-studied dark photon models. We consider current bounds from accelerator and collider searches, rare anomaly-induced decays, neutrino non-standard interactions, and dark matter direct detection. Despite the many existing constraints, these models predict a range of new signatures that can be seen in current and near future experiments, including dark gauge boson decays to the hadronic final states π+ππ0\pi^+ \pi^- \pi^0, π0γ\pi^0 \gamma, K+KK^+ K^-, and KSKLK_S K_L in FASER at LHC Run 3, enhancements of ντ\nu_{\tau} scattering rates in far-forward neutrino detectors, and thermal dark matter scattering in FLArE in the HL-LHC era. These models therefore motivate an array of different experiments in the far-forward region at the LHC, as could be accommodated in the proposed Forward Physics Facility

    Biocompatible Herder for Rapid Oil Spill Treatment over a Wide Temperature Range

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    PresentationOil spills caused by damaged oil rigs, ruptured pipelines, and tankers can have immediate and long-term detrimental effects on marine systems and aquatic life. Herein we further develop the merit of an oil spill recovery technique called oil herding. A herder is an amphiphilic oil-collecting surfactant which is applied to spray around the oil spill areas and is able to retract oil slicks, transforming them from a large thin layer to a small thick bulk. This herding treatment greatly simplifies further in-situ burning and the recycle process. The natural konjac glucomannan (KGM) material could be functionalized and examined here as an oil herder, which has the great advantage of nontoxicity, biocompatibility, and adaptability. Moreover, functionalized KGM is a non-ionic surfactant with no Krafft temperature. The absence of Krafft temperature gives KGM surfactants the unique ability to retain surfactant ability at temperatures nearing 0 °C. It unlocks a new direction for efficient oil herders within low temperature water areas, especially for oil spills treatment in Arctic waters, in the offshore safety control

    What Predicts Hospital Admissions in Community-Dwelling People With Parkinsonism?

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    Objectives: Previous studies have looked at the reasons for hospital admission in people with parkinsonism (PwP), yet few have looked at factors that precipitate admission. Methods: People with parkinsonism with a diagnosis of idiopathic Parkinson disease of Hoehn and Yahr stage III-V and those with Parkinson plus syndromes were assessed for motor and nonmotor symptoms, quality of life, and functional performance. Logistic regression was used to investigate predictors of hospital admission over the subsequent 2 years. Results: Overall, 162 patients consented to be part of the study. Seventy-one PwP (43.8%) had at least 1 hospital admission, and 17 (10.5%) patients had 3 or more admissions to hospital. Poorer cognition, more nonmotor symptoms, poorer quality of life, slower timed-up-and-go test scores, and abnormal swallow predicted a subsequent hospital admission. Discussion: Our study emphasizes the importance of nonmotor symptoms in predicting admission. A cost–benefit analysis of early intervention to prevent admission should be considered

    Effect of early tranexamic acid administration on mortality, hysterectomy, and other morbidities in women with post-partum haemorrhage (WOMAN): an international, randomised, double-blind, placebo-controlled trial

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    Background Post-partum haemorrhage is the leading cause of maternal death worldwide. Early administration of tranexamic acid reduces deaths due to bleeding in trauma patients. We aimed to assess the effects of early administration of tranexamic acid on death, hysterectomy, and other relevant outcomes in women with post-partum haemorrhage. Methods In this randomised, double-blind, placebo-controlled trial, we recruited women aged 16 years and older with a clinical diagnosis of post-partum haemorrhage after a vaginal birth or caesarean section from 193 hospitals in 21 countries. We randomly assigned women to receive either 1 g intravenous tranexamic acid or matching placebo in addition to usual care. If bleeding continued after 30 min, or stopped and restarted within 24 h of the first dose, a second dose of 1 g of tranexamic acid or placebo could be given. Patients were assigned by selection of a numbered treatment pack from a box containing eight numbered packs that were identical apart from the pack number. Participants, care givers, and those assessing outcomes were masked to allocation. We originally planned to enrol 15 000 women with a composite primary endpoint of death from all-causes or hysterectomy within 42 days of giving birth. However, during the trial it became apparent that the decision to conduct a hysterectomy was often made at the same time as randomisation. Although tranexamic acid could influence the risk of death in these cases, it could not affect the risk of hysterectomy. We therefore increased the sample size from 15 000 to 20 000 women in order to estimate the effect of tranexamic acid on the risk of death from post-partum haemorrhage. All analyses were done on an intention-to-treat basis. This trial is registered with ISRCTN76912190 (Dec 8, 2008); ClinicalTrials.gov, number NCT00872469; and PACTR201007000192283. Findings Between March, 2010, and April, 2016, 20 060 women were enrolled and randomly assigned to receive tranexamic acid (n=10 051) or placebo (n=10 009), of whom 10 036 and 9985, respectively, were included in the analysis. Death due to bleeding was significantly reduced in women given tranexamic acid (155 [1·5%] of 10 036 patients vs 191 [1·9%] of 9985 in the placebo group, risk ratio [RR] 0·81, 95% CI 0·65–1·00; p=0·045), especially in women given treatment within 3 h of giving birth (89 [1·2%] in the tranexamic acid group vs 127 [1·7%] in the placebo group, RR 0·69, 95% CI 0·52–0·91; p=0·008). All other causes of death did not differ significantly by group. Hysterectomy was not reduced with tranexamic acid (358 [3·6%] patients in the tranexamic acid group vs 351 [3·5%] in the placebo group, RR 1·02, 95% CI 0·88–1·07; p=0·84). The composite primary endpoint of death from all causes or hysterectomy was not reduced with tranexamic acid (534 [5·3%] deaths or hysterectomies in the tranexamic acid group vs 546 [5·5%] in the placebo group, RR 0·97, 95% CI 0·87-1·09; p=0·65). Adverse events (including thromboembolic events) did not differ significantly in the tranexamic acid versus placebo group. Interpretation Tranexamic acid reduces death due to bleeding in women with post-partum haemorrhage with no adverse effects. When used as a treatment for postpartum haemorrhage, tranexamic acid should be given as soon as possible after bleeding onset. Funding London School of Hygiene & Tropical Medicine, Pfizer, UK Department of Health, Wellcome Trust, and Bill & Melinda Gates Foundation

    The Forward Physics Facility at the High-Luminosity LHC

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    Effectiveness of a national quality improvement programme to improve survival after emergency abdominal surgery (EPOCH): a stepped-wedge cluster-randomised trial

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    Background: Emergency abdominal surgery is associated with poor patient outcomes. We studied the effectiveness of a national quality improvement (QI) programme to implement a care pathway to improve survival for these patients. Methods: We did a stepped-wedge cluster-randomised trial of patients aged 40 years or older undergoing emergency open major abdominal surgery. Eligible UK National Health Service (NHS) hospitals (those that had an emergency general surgical service, a substantial volume of emergency abdominal surgery cases, and contributed data to the National Emergency Laparotomy Audit) were organised into 15 geographical clusters and commenced the QI programme in a random order, based on a computer-generated random sequence, over an 85-week period with one geographical cluster commencing the intervention every 5 weeks from the second to the 16th time period. Patients were masked to the study group, but it was not possible to mask hospital staff or investigators. The primary outcome measure was mortality within 90 days of surgery. Analyses were done on an intention-to-treat basis. This study is registered with the ISRCTN registry, number ISRCTN80682973. Findings: Treatment took place between March 3, 2014, and Oct 19, 2015. 22 754 patients were assessed for elegibility. Of 15 873 eligible patients from 93 NHS hospitals, primary outcome data were analysed for 8482 patients in the usual care group and 7374 in the QI group. Eight patients in the usual care group and nine patients in the QI group were not included in the analysis because of missing primary outcome data. The primary outcome of 90-day mortality occurred in 1210 (16%) patients in the QI group compared with 1393 (16%) patients in the usual care group (HR 1·11, 0·96–1·28). Interpretation: No survival benefit was observed from this QI programme to implement a care pathway for patients undergoing emergency abdominal surgery. Future QI programmes should ensure that teams have both the time and resources needed to improve patient care. Funding: National Institute for Health Research Health Services and Delivery Research Programme
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