162 research outputs found

    In-Situ Neutron Diffraction Under Tensile Loading of Powder-in-Tube Cu/Nb3_{3}Sn Composite Wires: Effect of Reaction Heat Treatment on Texture, Internal Stress State and Load Transfer

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    The strain induced degradation of Nb3_{3}Sn superconductors can hamper the performance of high field magnets. We report elastic strain measurements in the different phases of entire non-heat treated and fully reacted Nb3_{3}Sn composite strands as a function of uniaxial stress during in-situ deformation under neutron beam. After the reaction heat treatment the Cu matrix loses entirely its load carrying capability and the applied stress is transferred to the remaining Nb-Ta alloy and to the brittle (Nb-Ta)3Sn phase, which exhibits a preferential grain orientation parallel to the strand axis

    Goitre and Iodine Deficiency in Europe

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    The prevalence of endemic iodine-deficiency goitre in Europe has been reduced in many areas by the introduction of iodination programmes. Recent reports, however, show that goitre remains a significant problem and that its prevalence has not decreased in a number of European countries. Hetzel1 has pointed out that the high global prevalence of iodine-deficiency disorders could be eradicated within 5-10 years by introduction of an iodised salt programme. The current World Health Organisation recommendations for iodine intake are between 150 and 300 ÎĽg/da

    Temperature Induced Degradation of Nb Ti/Cu Composite Superconductors

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    The degradation mechanisms of state-of-the-art Nb-Ti/Cu superconductors are described, based on in-situ synchrotron X-ray diffraction measurements during heat treatment. A quantitative description of the Nb-Ti/Cu degradation in terms of critical current density, Cu stabiliser resistivity and mechanical composite strength is presented. In an applied magnetic field a significant critical current degradation is already observed after a 5-minute 400 °C heat treatment, due to variations of a-Ti precipitate size and distribution within the Nb-Ti alloy filaments. A strong degradation of the strand mechanical properties is observed after several minutes heating above 550 °C, which is also the temperature at which the formation of Cu Ti intermetallic phases is detected. Several minutes heating at 250 °C are sufficient to increase the RRR of the strongly cold work strands inside a Rutherford type cable from about 80 to about 240. Heating for several minutes at 400 °C does not cause a significant conductor degradation in self-field and, thus, leaves enough temperature margin for the electrical interconnection of Nb-Ti/Cu conductors with common low temperature solders

    Phase Transformations during the Reaction Heat Treatment

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    The evolution of Nb containing phases during the diffusion heat treatment of three different high critical current Nb3_{3}Sn strand types is compared, based on synchrotron X-ray diffraction results that have been obtained at the ID15 beam line of the European Synchrotron Radiation Facility (ESRF). In all strands studied, Nb3_{3}Sn formation is preceded by the formation of a Cu-Nb-Sn ternary phase, NbSn2 and Nb6Sn5. As compared to the PIT and Tube Type strand, the amount of these phases formed in the RRP strand is relatively small. In the RRP strand subelements with a fine filament structure Nb3_{3}Sn grows more quickly, thereby preventing to a large extent the formation of the other higher tin phases

    Harnessing the wisdom of crowds can improve guideline compliance of antibiotic prescribers and support antimicrobial stewardship

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    open access articleAntibiotic overprescribing is a global challenge contributing to rising levels of antibiotic resistance and mortality. We test a novel approach to antibiotic stewardship. Capitalising on the concept of “wisdom of crowds”, which states that a group’s collective judgement often outperforms the average individual, we test whether pooling treatment durations recommended by different prescribers can improve antibiotic prescribing. Using international survey data from 787 expert antibiotic prescribers, we run computer simulations to test the performance of the wisdom of crowds by comparing three data aggregation rules across different clinical cases and group sizes. We also identify patterns of prescribing bias in recommendations about antibiotic treatment durations to quantify current levels of overprescribing. Our results suggest that pooling the treatment recommendations (using the median) could improve guideline compliance in groups of three or more prescribers. Implications for antibiotic stewardship and the general improvement of medical decision making are discussed. Clinical applicability is likely to be greatest in the context of hospital ward rounds and larger, multidisciplinary team meetings, where complex patient cases are discussed and existing guidelines provide limited guidance

    Tensile Properties of the Individual Phases in Unreacted Multifilament Nb3_{3}Sn Wires

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    The room temperature elastic and plastic properties under uniaxial tensile loading of the different phases of an un-reacted, internal-tin process, Nb3_{3}Sn wire have been determined by tensile tests of whole wires and of extracted Ta, Nb and Nb alloy filaments, as well as by indentation hardness measurements in metallographic wire cross sections

    Telemonitoring Devices and Systems: Current Status and Future Trends

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    In the future, the number of elderly and chronically ill will be quite large. Additionally, pathologies will in many cases be in comorbidity. Alongside this reality, the health care resources will be insufficient for the population, thus the current research for solutions that can be fully implemented in the future. There are available several telemonitoring devices and systems for chronic diseases. Massive use of these devices will be essential to address the current and future lack of health system resources. Research on telemonitoring devices and systems for chronic diseases was con-ducted in academic and scientific databases. The technical specifications were collected in the manufacturers’ web page. The gathered data was analysed and compared in order to propose scenarios for the future trend of technical specifi-cations required in telemonitoring devices/system is performed. Telemonitoring for chronic diseases can bring great benefits to patient and health systems. Widening this practice will be a reality in the near future. This procedure will be fostered by the promotion and regulation of interoperability between de-vices/systems, as well as of front-end programs providing the link between health support systems. Interoperability issues are the main flaw of tedevicesring devices/systems on the market today.info:eu-repo/semantics/publishedVersio

    Telemonitoring Devices and Systems: Current Status and Future Trends

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    In the future, the number of elderly and chronically ill will be quite large. Additionally, pathologies will in many cases be in comorbidity. Along with this reality, the health care resources will be insufficient for the population, thus the current research for technological solutions needs to be implemented in the future. There are available several telemonitoring devices and systems for chronic diseases. Massive use of these devices will be essential to address the current and future lack of health system resources. Research on telemonitoring devices and systems for chronic diseases was conducted in academic and scientific databases. The technical specifications were collected from the manufacturers’ web page. The collected data was analysed and compared in order to propose scenarios for the future trend of technical specifications required in telemonitoring devices/system. Telemonitoring for chronic diseases can bring great benefits to patient and health systems. Widening this practice will be a reality in the near future. This procedure will be fostered by the promotion and regulation of interoperability between devices/systems, as well as of front-end programs providing the link between health support systems. Interoperability issues are the main flaws of telemonitoring devices/systems on the market today.info:eu-repo/semantics/publishedVersio

    The goitre rate, its association with reproductive failure, and the knowledge of iodine deficiency disorders (IDD) among women in Ethiopia: Cross-section community based study

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    <p>Abstract</p> <p>Background</p> <p>Iodine deficiency is severe public health problem in Ethiopia. Although urinary iodine excretion level (UIE) is a better indicator for IDD the goitre rate is commonly used to mark the public health significance. The range of ill effect of IDD is however beyond goitre in Ethiopia. In this study the prevalence of goitre and its association with reproductive failure, and the knowledge of women on Iodine Deficiency were investigated.</p> <p>Methods</p> <p>A cross-section community based study was conducted during February to May 2005 in 10998 women in child bearing age of 15 to 49 years. To assess the state of iodine deficiency in Ethiopia, a multistage "Proportional to Population Size" (PPS) sampling methods was used, and WHO/UNICEF/ICCIDD recommended method for goitre classification.</p> <p>Results</p> <p>Total goitre prevalence (weighted) was 35.8% (95% CI 34.5–37.1), 24.3% palpable and 11.5% visible goitre. This demonstrates that more than 6 million women were affected by goitre.</p> <p>Goitre prevalence in four regional states namely Southern Nation Nationalities and People (SNNP), Oromia, Bebshandul-Gumuz and Tigray was greater than 30%, an indication of severe iodine deficiency. In the rest of the regions except Gambella, the IDD situation was mild to moderate. According to WHO/UNICEF/ICCIDD this is a lucid indication that IDD is a major public health problem in Ethiopia. Women with goitre experience more pregnancy failure (X<sup>2 </sup>= 16.5, p < 0.001; OR = 1.26, 1.12 < OR < 1.41) than non goitrous women. Similarly reproductive failure in high goitre endemic areas was significantly higher (X<sup>2 </sup>= 67.52; p < 0.001) than in low. More than 90% of child bearing age women didn't know the cause of iodine deficiency and the importance of iodated salt.</p> <p>Conclusion</p> <p>Ethiopia is at risk of iodine deficiency disorders. The findings presented in this report emphasis on a sustainable iodine intervention program targeted at population particularly reproductive age women. Nutrition education along with Universal Salt Iodization program and iodized oil capsule distribution in some peripheries where iodine deficiency is severe is urgently required.</p
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