60 research outputs found

    Analysis of the Thermal and Magnetic Properties of Amorphous Fe 61Co10Zr2.5Hf2.5Me2W2B20 (Where Me = Mo, Nb, Ni Or Y) Ribbons

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    The paper presents the results of structural and magnetic properties and thermal stability for a group of functional materials based on Fe61Co10Zr2.5Hf2.5Me2W2B20 (where Me = Mo, Nb, Ni or Y). Samples were obtained in the form of ribbons using melt-spinning method. The X-ray diffraction patterns of investigated samples confirmed their amorphous structure. Based on the analysis of DSC curves characteristic temperatures: glass forming temperature (Tg), crystallization temperature (Tx) and temperature range of the supercooled liquid ΔTx were determined. Small addition of transition metals elements has strong influence on magnetic and thermal parameters of studied materials. The comprehensive studies revealed that in terms of magnetic properties the Ni-addition resulted in highest reduction in coercivity and anisotropy field

    The Lake Baikal neutrino experiment: selected results

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    We review the present status of the lake Baikal Neutrino Experiment and present selected physical results gained with the consequetive stages of the stepwise increasing detector: from NT-36 to NT-96. Results cover atmospheric muons, neutrino events, very high energy neutrinos, search for neutrino events from WIMP annihilation, search for magnetic monopoles and environmental studies. We also describe an air Cherenkov array developed for the study of angular resolution of NT-200.Comment: 25 pages, 12 figures. To appear in the Procrrdings of International Conference on Non-Accelerator New Physics, June 28 - July 3, 1999, Dubna, Russi

    Microstructure and high temperature oxidation of modified ductile ni-resist alloy with higher manganese content

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    In this study, ductile Ni-resist with a minimum of 18 wt% nickel composition was modified. Up to 12 wt% manganese was added together with 10 wt% nickel to investigate the effects of the alloying elements on its microstructure, mechanical properties and isothermal oxidation behaviour. The results show a higher manganese composition on modified ductile Ni-resist with increased carbide formation, and a slightly decreased elevated temperature tensile strength. The addition of higher Mn [wt%] slightly increased the oxidation resistance. Three different oxide layers were observed on the modified ductile Ni-resist after 25 h hot corrosion at 765◦C

    Sex-stratified patterns of emergency cardiovascular admissions prior and during the COVID-19 pandemic

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    The COVID-19 pandemic has had a significant impact on global public health, with long-term consequences that are still largely unknown. This study aimed to assess the data regarding acute cardiovascular hospital admissions in five European centers before and during the pandemic. A multicenter, multinational observational registry was created, comparing admissions to the emergency departments during a 3-months period in 2020 (during the pandemic) with the corresponding period in 2019 (pre-pandemic). Data on patient demographics, COVID-19 test results, primary diagnosis, comorbidities, heart failure profile, medication use, and laboratory results were collected. A total of 8778 patients were included in the analysis, with 4447 patients in 2019 and 4331 patients in 2020. The results showed significant differences in the distribution of cardiovascular diseases between the two years. The frequency of pulmonary embolism (PE) increased in 2020 compared to 2019, while acute heart failure (AHF) and other cardiovascular diseases decreased. The odds of PE incidence among hospitalized patients in 2020 were 1.316-fold greater than in 2019. The incidence of AHF was 50.83% less likely to be observed in 2020, and the odds for other cardiovascular diseases increased by 17.42% between the 2 years. Regarding acute coronary syndrome (ACS), the distribution of its types differed between 2019 and 2020, with an increase in the odds of ST-segment elevation myocardial infarction (STEMI) in 2020. Stratification based on sex revealed further insights. Among men, the incidence of AHF decreased in 2020, while other cardiovascular diseases increased. In women, only the incidence of STEMI showed a significant increase. When analyzing the influence of SARS-CoV-2 infection, COVID-positive patients had a higher incidence of PE compared to COVID-negative patients. COVID-positive patients with ACS also exhibited symptoms of heart failure more frequently than COVID-negative patients. These findings provide valuable information on the impact of the COVID-19 pandemic on acute cardiovascular hospital admissions. The increased incidence of PE and changes in the distribution of other cardiovascular diseases highlight the importance of monitoring and managing cardiovascular health during and post pandemic period. The differences observed between sexes emphasize the need for further research to understand potential sex-specific effects of COVID-19 on cardiovascular outcomes

    Impact of coronavirus disease 2019 (COVID-19) outbreak on acute admissions at the emergency and cardiology departments across Europe

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    PURPOSE: We evaluated whether the severe acute respiratory syndrome coronavirus 2 (SARS-COV-2) pandemic was associated with changes in the pattern of acute cardiovascular admissions across European centers.METHODS: We set-up a multicenter, multinational, pan-European observational registry in 15 centers from 12 countries. All consecutive acute admissions to emergency departments and cardiology departments throughout a 1-month period during the COVID-19 outbreak were compared with an equivalent 1-month period in 2019. The acute admissions to cardiology departments were classified into 5 major categories: acute coronary syndrome, acute heart failure, arrhythmia, pulmonary embolism, and other.RESULTS: Data from 54,331 patients were collected and analyzed. Nine centers provided data on acute admissions to emergency departments comprising 50,384 patients: 20,226 in 2020 compared with 30,158 in 2019 (incidence rate ratio [IRR] with 95% confidence interval [95%CI]: 0.66 [0.58-0.76]). The risk of death at the emergency departments was higher in 2020 compared to 2019 (odds ratio [OR] with 95% CI: 4.1 [3.0-5.8], P < 0.0001). All 15 centers provided data on acute cardiology departments admissions: 3007 patients in 2020 and 4452 in 2019; IRR (95% CI): 0.68 (0.64-0.71). In 2020, there were fewer admissions with IRR (95% CI): acute coronary syndrome: 0.68 (0.63-0.73); acute heart failure: 0.65 (0.58-0.74); arrhythmia: 0.66 (0.60-0.72); and other: 0.68(0.62-0.76). We found a relatively higher percentage of pulmonary embolism admissions in 2020: odds ratio (95% CI): 1.5 (1.1-2.1), P = 0.02. Among patients with acute coronary syndrome, there were fewer admissions with unstable angina: 0.79 (0.66-0.94); non-ST segment elevation myocardial infarction: 0.56 (0.50-0.64); and ST-segment elevation myocardial infarction: 0.78 (0.68-0.89).CONCLUSION: In the European centers during the COVID-19 outbreak, there were fewer acute cardiovascular admissions. Also, fewer patients were admitted to the emergency departments with 4 times higher death risk at the emergency departments. (C) 2020 Published by Elsevier Inc.Cardiolog

    The evolving SARS-CoV-2 epidemic in Africa: Insights from rapidly expanding genomic surveillance

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    INTRODUCTION Investment in Africa over the past year with regard to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) sequencing has led to a massive increase in the number of sequences, which, to date, exceeds 100,000 sequences generated to track the pandemic on the continent. These sequences have profoundly affected how public health officials in Africa have navigated the COVID-19 pandemic. RATIONALE We demonstrate how the first 100,000 SARS-CoV-2 sequences from Africa have helped monitor the epidemic on the continent, how genomic surveillance expanded over the course of the pandemic, and how we adapted our sequencing methods to deal with an evolving virus. Finally, we also examine how viral lineages have spread across the continent in a phylogeographic framework to gain insights into the underlying temporal and spatial transmission dynamics for several variants of concern (VOCs). RESULTS Our results indicate that the number of countries in Africa that can sequence the virus within their own borders is growing and that this is coupled with a shorter turnaround time from the time of sampling to sequence submission. Ongoing evolution necessitated the continual updating of primer sets, and, as a result, eight primer sets were designed in tandem with viral evolution and used to ensure effective sequencing of the virus. The pandemic unfolded through multiple waves of infection that were each driven by distinct genetic lineages, with B.1-like ancestral strains associated with the first pandemic wave of infections in 2020. Successive waves on the continent were fueled by different VOCs, with Alpha and Beta cocirculating in distinct spatial patterns during the second wave and Delta and Omicron affecting the whole continent during the third and fourth waves, respectively. Phylogeographic reconstruction points toward distinct differences in viral importation and exportation patterns associated with the Alpha, Beta, Delta, and Omicron variants and subvariants, when considering both Africa versus the rest of the world and viral dissemination within the continent. Our epidemiological and phylogenetic inferences therefore underscore the heterogeneous nature of the pandemic on the continent and highlight key insights and challenges, for instance, recognizing the limitations of low testing proportions. We also highlight the early warning capacity that genomic surveillance in Africa has had for the rest of the world with the detection of new lineages and variants, the most recent being the characterization of various Omicron subvariants. CONCLUSION Sustained investment for diagnostics and genomic surveillance in Africa is needed as the virus continues to evolve. This is important not only to help combat SARS-CoV-2 on the continent but also because it can be used as a platform to help address the many emerging and reemerging infectious disease threats in Africa. In particular, capacity building for local sequencing within countries or within the continent should be prioritized because this is generally associated with shorter turnaround times, providing the most benefit to local public health authorities tasked with pandemic response and mitigation and allowing for the fastest reaction to localized outbreaks. These investments are crucial for pandemic preparedness and response and will serve the health of the continent well into the 21st century

    The Influence of Heat Treatment on Soft Magnetic Properties of the Fe60Co10Mo2Y8B20Fe_{60}Co_{10}Mo_{2}Y_{8}B_{20} Alloy

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    This paper presents the results of studies on the magnetic properties of the Fe60Co10Mo2Y8B20Fe_{60}Co_{10}Mo_{2}Y_{8}B_{20} alloy. The samples were fabricated in the form of plates by the injection-casting method. The structure of the investigated alloy, in the as-quenched state and after annealing, was verified by using X-ray diffractometry. The magnetization curves as a function of temperature were measured by a force magnetometer. From thermomagnetic curves the Curie temperature of the alloy was determined. As a critical parameter β was chosen to be equal to 0.36 for these calculations, it confirmed that the alloys may be considered as ferromagnetic of the Heisenberg type. Additionally, using a vibrating sample magnetometer the magnetization and coercivity field were studied (in magnetic field up to 2 T)
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