45 research outputs found

    Reconstructing phase diagrams from local measurements via Gaussian processes: mapping the temperature-composition space to confidence

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    We show the ability to map the phase diagram of a relaxor-ferroelectric system as a function of temperature and composition through local hysteresis curve acquisition, with the voltage spectroscopy data being used as a proxy for the (unknown) microscopic state or thermodynamic parameters of materials. Given the discrete nature of the measurement points, we use Gaussian processes to reconstruct hysteresis loops in temperature and voltage space, and compare the results with the raw data and bulk dielectric spectroscopy measurements. The results indicate that the surface transition temperature is similar for all but one composition with respect to the bulk. Through clustering algorithms, we recreate the main features of the bulk diagram, and provide statistical confidence estimates for the reconstructed phase transition temperatures. We validate the method by using Gaussian processes to predict hysteresis loops for a given temperature for a composition unseen by the algorithm, and compare with measurements. These techniques can be used to map phase diagrams from functional materials in an automated fashion, and provide a method for uncertainty quantification and model selection

    Ferroelectric ceramic dispersion to enhance the beta phase of polymer for improving dielectric and ferroelectric properties of the composites

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    Ferroelectric ceramic-polymer composites consisting of Poly Vinyledine Fluoride-Hexa Fluoro Propylene (PVDF-HFP) as polymer host and 0.5Ba(Zr0.2Ti0.8)O-3-0.5(Ba0.7Ca0.3)TiO3(BZT-BCT) ceramics as filler were prepared using solution casting technique. These composites are characterized for structural, microstructural, vibrational, optical, dielectric and ferroelectric properties at various experimental conditions. The electroactive beta phase fraction (observed from XRD and FTIR analysis) increases as the filler concentration increases up to 20 wt% of BZT-BCT and above that its value decreases. FTIR results were analyzed to understand the mechanism of enhancement of beta phase by the interaction between negatively surface charged ions of filler with the CH(2)dipole of polymer matrix. UV-visible spectroscopy also employed to confirm polymer-ceramic filler interaction. Variation of the dielectric constant with different filler concentrations is explained using the percolation theory. Finally, the interplay between the functional properties and the beta phase is discussed in detail

    Phase transition and enhanced magneto-dielectric response in BiFeO3-DyMnO3 multiferroics

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    This work is partially supported by DST fast track Project No. SR/FTP/PS-16/2009. Dhiren K. Pradhan acknowledges IFN (NSF Grant No. EPS—01002410) for fellowship. The work at UPR was supported by National Science Foundation (NSF DMR 1410869) and Institute for Functional Nanomaterials (IFN).We report systematic studies on crystal structure and magneto-dielectric properties of (1 − x) BiFeO3-x DyMnO3 (0.0 ≤ x ≤ 0.2) nanoceramics synthesized by auto-combustion method. Rietveld refinement of X-ray diffraction data indicates a structural transition from R3c to R3c + Pn21a at x = 0.1. Field emission scanning electron micrographs display a decrease in grain size with increase in x. The presence of dielectric anomalies around antiferromagnetic transition temperature implies the magnetoelectric coupling. Dielectric measurements showed decrease in magnetic ordering temperature with increasing x in agreement with differential scanning calorimetry results. A significant increase in magnetization has been found with increasing DyMnO3 substitution. Magneto-impedance spectroscopy reveals a significant change (∼18%) in dielectricpermittivity at H = 2 T for x = 0.2.Peer reviewe

    Research Productivity and Visualization of the All India Institute of Medical Sciences (AIIMS) Bhubaneswar during 2012-2019: A Scientometric Approach

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    The purpose of the present study is to evaluate the productivity of research at the Indian Institute of Medical Sciences (AIIMS), Bhubaneswar, in the first eight years (2012-2019) of its establishment. In this study, the authors used a number of Scientometric indices to assess research productivity. The results of the study showed that in the selected period of 2019, most research publications appear with an average growth rate of 46.43%. Most of the comments were written by five or more authors. In addition, R.R. Das is recognized as the most prolific author, and the Journal of Clinical and Diagnostic Research is one of the most popular sources of publications, with the largest number of publications with the help of scientists from AIIMS. The UK and AIIMS New Delhi are the countries and institutions that work best together. In addition, the study also found that the Indian Medical Research Council is the leading research institution with AIIMS Bhubaneswar. The title of Maiti R Metronomic Chemotherapy , published in the Journal of Pharmacology and Pharmacotherapeutics, received the most citations. this sentence is long and somewhat complicated. This study is useful for policymakers and stakeholders in medical institutions to improve their research prospects

    Research Productivity and Visualization of the All India Institute of Medical Sciences (AIIMS) Bhubaneswar during 2012-2019: A Scientometric Approach

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    Scientometric analysis of research results enable individuals and institutions to understand their current status and improve their performance. The present study evaluate the productivity of research at the Indian Institute of Medical Sciences (AIIMS), Bhubaneswar using scientometric parameters. Study revealed that most research publications appeared with an average growth rate of 46.43%. and R.R. Das was the most prolific author. Journal of Clinical and Diagnostic Research was found to be the most popular source of publications and AIIMS Bhubaneswar the leading research institution. The title of Maiti R 'Metronomic Chemotherapy' published in the Journal of Pharmacology and Pharmacotherapeutics, received the highest citations. The findings of the study will be of use to the policy makers to improve research in the the area

    Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries

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    Abstract Background Healthcare cannot achieve net-zero carbon without addressing operating theatres. The aim of this study was to prioritize feasible interventions to reduce the environmental impact of operating theatres. Methods This study adopted a four-phase Delphi consensus co-prioritization methodology. In phase 1, a systematic review of published interventions and global consultation of perioperative healthcare professionals were used to longlist interventions. In phase 2, iterative thematic analysis consolidated comparable interventions into a shortlist. In phase 3, the shortlist was co-prioritized based on patient and clinician views on acceptability, feasibility, and safety. In phase 4, ranked lists of interventions were presented by their relevance to high-income countries and low–middle-income countries. Results In phase 1, 43 interventions were identified, which had low uptake in practice according to 3042 professionals globally. In phase 2, a shortlist of 15 intervention domains was generated. In phase 3, interventions were deemed acceptable for more than 90 per cent of patients except for reducing general anaesthesia (84 per cent) and re-sterilization of ‘single-use’ consumables (86 per cent). In phase 4, the top three shortlisted interventions for high-income countries were: introducing recycling; reducing use of anaesthetic gases; and appropriate clinical waste processing. In phase 4, the top three shortlisted interventions for low–middle-income countries were: introducing reusable surgical devices; reducing use of consumables; and reducing the use of general anaesthesia. Conclusion This is a step toward environmentally sustainable operating environments with actionable interventions applicable to both high– and low–middle–income countries
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