14 research outputs found

    Ternary intermetallic compounds synthesized by molten-metal-solution growth

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    Several new ternary compounds have been synthesized by growing crystals of metallic compounds in a molten-metal solution. Quantum-stability diagrams predict whether a ternary intermetallic compound, a quasi-ternary compound or a binary compound will crystallize from the solution upon slow cooling

    GENERAL CONDITION FOR AMORPHISATION OF INTERMETALLIC COMPOUNDS

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    Using simple thermodynamic considerations for the Gibbs free energies of the crystalline and amorphous states a general condition for the solid-state amorphisation of intermetallic compounds by irradiation or mechanical impact was derived. It was obtained that the amorphisation is possible if the maximum elastic energy, ÆŠHmel, stored during the (chemical) order-disorder transition is larger than ÆŠHatop, the enthalpy of the topological change of amorphisation. This condition can be rewritten into the form : the amorphisation is not possible if the order-disorder temperature is lower than the melting temperature, TcTm - in contrast to Johnson's condition - the possibility of the amorphisation depends on the relative magnitude of the elastic mismatch energy and the chemical energy of ordering. If their ratio is large enough the amorphisation is possible. Detailed calculations, carried out for a large number of compounds, led to a satisfactory agreement with the experimental observations

    Ternary intermetallic compounds synthesized by molten-metal-solution growth

    No full text
    Several new ternary compounds have been synthesized by growing crystals of metallic compounds in a molten-metal solution. Quantum-stability diagrams predict whether a ternary intermetallic compound, a quasi-ternary compound or a binary compound will crystallize from the solution upon slow cooling

    Women receiving massive transfusion due to postpartum hemorrhage: A comparison over time between two nationwide cohort studies

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    Introduction Incidence of massive transfusion after birth was high in the Netherlands between 2004 and 2006 compared with other high-income countries. This study investigated incidence, causes, management and outcome of women receiving massive transfusion due to postpartum hemorrhage in the Netherlands in more recent years. Material and methods Data for all pregnant women who received eight or more units of packed red blood cells from a gestational age of 20 weeks and within the first 24 hours after childbirth, during 2011 and 2012, were obtained from a nationwide retrospective cohort study, including 61 hospitals with a maternity unit in the Netherlands. Results Incidence of massive transfusion due to postpartum hemorrhage decreased to 65 per 100 000 births (95% CI 56-75) between 2011 and 2012, from 91 per 100 000 births (95% CI 81-101) between 2004 and 2006, while median blood loss increased from 4500 mL (interquartile range 3250-6000) to 6000 mL (interquartile range 4500-8000). Uterine atony remained the leading cause of hemorrhage. Thirty percent (53/176) underwent peripartum hysterectomy between 2011 and 2012, compared with 25% (83/327) between 2004 and 2006. Case fatality rate for women who received massive transfusion due to postpartum hemorrhage was 2.3% (4/176) between 2011 and 2012, compared with 0.9% (3/327) between 2004 and 2006. Conclusions The incidence of postpartum hemorrhage with massive transfusion decreased in the Netherlands between both time frames, but remained an important cause of maternal mortality and morbidity, including peripartum hysterectomy. National surveillance of maternal morbidity and mortality due to postpartum hemorrhage through an improved and continuous registration with confidential enquiries may lead to the identification of clear improvements of maternal care
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