1,082 research outputs found

    Multiferroic clusters: a new perspective for relaxor-type room-temperature multiferroics

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    Multiferroics are promising for sensor and memory applications, but despite all efforts invested in their research no single-phase material displaying both ferroelectricity and large magnetization at room-temperature has hitherto been reported. This situation has substantially been improved in the novel relaxor ferroelectric single-phase (BiFe0.9Co0.1O3)0.4-(Bi1/2K1/2TiO3)0.6, where polar nanoregions (PNR) transform into static-PNR (SPNR) as evidenced by piezoresponse force microscopy (PFM) and simultaneously enable congruent multiferroic clusters (MFC) to emerge from inherent strongly magnetic Bi(Fe,Co)O3 rich regions as verified by magnetic force microscopy (MFM) and secondary ion mass spectrometry (SIMS). The material’s exceptionally large Néel temperature TN = 670 ± 10 K, as found by neutron diffraction, is proposed to be a consequence of ferrimagnetic order in MFC. On these MFC, exceptionally large direct and converse magnetoelectric coupling coefficients, α ≈ 1.0 x 10-5 s/m at room-temperature, were measured by PFM and MFM respectively. We expect the non-ergodic relaxor properties which are governed by the Bi1/2K1/2TiO3 component to play a vital role in the strong ME coupling, by providing an electrically and mechanically flexible environment to MFC. This new class of non-ergodic relaxor multiferroics bears great potential for applications. Especially the prospect of a ME nanodot storage device seems appealing

    First-time synthesis of a magnetoelectric core-shell composite via conventional solid-state reaction

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    In recent years, multiferroics and magnetoelectrics have demonstrated their potential for a variety of applications. However, no magnetoelectric material has been translated to a real application yet. Here, we report for the first time that a magnetoelectric core–shell ceramic, is synthesized via a conventional solid-state reaction, where core–shell grains form during a single sintering step. The core consists of ferrimagnetic CoFe2O4CoFe_{2}O_{4}, which is surrounded by a ferroelectric shell consisting of (BiFeO3)x–(Bi1/2K1/2TiO3)1−x(BiFeO_{3})_{x}–(Bi_{1/2}K_{1/2}TiO_{3})_{1−x}. We establish the core–shell nature of these grains by transmission-electron microscopy (TEM) and find an epitaxial crystallographic relation between core and shell, with a lattice mismatch of 6 ± 0.7%. The core–shell grains exhibit exceptional magnetoelectric coupling effects that we attribute to the epitaxial connection between the magnetic and ferroelectric phase, which also leads to magnetic exchange coupling as demonstrated by neutron diffraction. Apparently, ferrimagnetic CoFe2O4CoFe_{2}O_{4} cores undergo a non-centrosymmetric distortion of the crystal structure upon epitaxial strain from the shell, which leads to simultaneous ferrimagnetism and piezoelectricity. We conclude that in situ core–shell ceramics offer a number of advantages over other magnetoelectric composites, such as lower leakage current, higher density and absence of substrate clamping effects. At the same time, the material is predestined for application, since its preparation is cost-effective and only requires a single sintering step. This discovery adds a promising new perspective for the application of magnetoelectric materials

    An intraoperative telemedicine program to improve perioperative quality measures: The ACTFAST-3 randomized clinical trial

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    IMPORTANCE: Telemedicine for clinical decision support has been adopted in many health care settings, but its utility in improving intraoperative care has not been assessed. OBJECTIVE: To pilot the implementation of a real-time intraoperative telemedicine decision support program and evaluate whether it reduces postoperative hypothermia and hyperglycemia as well as other quality of care measures. DESIGN, SETTING, AND PARTICIPANTS: This single-center pilot randomized clinical trial (Anesthesiology Control Tower-Feedback Alerts to Supplement Treatments [ACTFAST-3]) was conducted from April 3, 2017, to June 30, 2019, at a large academic medical center in the US. A total of 26 254 adult surgical patients were randomized to receive either usual intraoperative care (control group; n = 12 980) or usual care augmented by telemedicine decision support (intervention group; n = 13 274). Data were initially analyzed from April 22 to May 19, 2021, with updates in November 2022 and February 2023. INTERVENTION: Patients received either usual care (medical direction from the anesthesia care team) or intraoperative anesthesia care monitored and augmented by decision support from the Anesthesiology Control Tower (ACT), a real-time, live telemedicine intervention. The ACT incorporated remote monitoring of operating rooms by a team of anesthesia clinicians with customized analysis software. The ACT reviewed alerts and electronic health record data to inform recommendations to operating room clinicians. MAIN OUTCOMES AND MEASURES: The primary outcomes were avoidance of postoperative hypothermia (defined as the proportion of patients with a final recorded intraoperative core temperature \u3e36 °C) and hyperglycemia (defined as the proportion of patients with diabetes who had a blood glucose level ≤180 mg/dL on arrival to the postanesthesia recovery area). Secondary outcomes included intraoperative hypotension, temperature monitoring, timely antibiotic redosing, intraoperative glucose evaluation and management, neuromuscular blockade documentation, ventilator management, and volatile anesthetic overuse. RESULTS: Among 26 254 participants, 13 393 (51.0%) were female and 20 169 (76.8%) were White, with a median (IQR) age of 60 (47-69) years. There was no treatment effect on avoidance of hyperglycemia (7445 of 8676 patients [85.8%] in the intervention group vs 7559 of 8815 [85.8%] in the control group; rate ratio [RR], 1.00; 95% CI, 0.99-1.01) or hypothermia (7602 of 11 447 patients [66.4%] in the intervention group vs 7783 of 11 672 [66.7.%] in the control group; RR, 1.00; 95% CI, 0.97-1.02). Intraoperative glucose measurement was more common among patients with diabetes in the intervention group (RR, 1.07; 95% CI, 1.01-1.15), but other secondary outcomes were not significantly different. CONCLUSIONS AND RELEVANCE: In this randomized clinical trial, anesthesia care quality measures did not differ between groups, with high confidence in the findings. These results suggest that the intervention did not affect the targeted care practices. Further streamlining of clinical decision support and workflows may help the intraoperative telemedicine program achieve improvement in targeted clinical measures. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT02830126

    Coastal Ocean Processes : a science prospectus

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    CoOP (Coastal Ocean Processes) is an organization meant to study major interdisciplinary scientific problems in the coastal ocean. Its goal is "to obtain a new level of quantitative understanding of the processes that dominate the transformations, transport and fates of biologically, chemically and geologically important matter on the continental margin". Central to obtaining this understanding will be advances in observing and modeling the cross-shelf component of transport. More specific objectives are to understand 1) cross-margin exchanges, 2) air sea exchanges, 3) benthic-pelagic exchanges, 4) terrestrial inputs and 5) biological and chemical transformations within the water column. CoOP research will be carried out primarly through a series of process-oriented field studies, each involving about two years of measurements. Each of these field studies is to be initiated and defined through a community workshop. In addition to the process studies, CoOP will also involve modeling, long time series, exploratory studies, remote sensing, technological innovation, data archiving and communications. A CoOP pilot study has been approved for funding by the National Science Foundation, and funding will begin in 1992. The CoOP science effort is thus already underway.Funding was provided by the National Science Foundation under Grant No. OCE-9108993

    Social Class

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    Discussion of class structure in fifth-century Athens, historical constitution of theater audiences, and the changes in the comic representation of class antagonism from Aristophanes to Menander
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