120 research outputs found

    Effect of area ratio of the primary nozzle on steam ejector performance considering nonequilibrium condensations

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    This is the final version. Available on open access from Elsevier via the DOI in this recordThe formation and evaporation of nanodroplets in steam ejectors is neglected in many numerical simulations. We analyse the influence of a primary nozzle on steam ejector performances considering phase change processes. The numerical model is validated in detail against experimental data of supersonic nozzles and steam ejectors available in the literature. The results show that the first nonequilibrium condensation is observed within the primary nozzle, while under-expanded supersonic flow causes a second nucleation-condensation process to achieve a large liquid fraction of 0.26 in the steam ejector. The compression process of the supersonic flow results in a steep decrease of the degree of subcooling leading to droplet evaporations. The condensation and evaporation processes repeat alternatively depending on the flow behaviour in the mixing section. The increasing area ratio leads to the transition of the flow structure from under-expanded flows to over-expanded flows in the mixing section. The droplet diameter is about 7 nm in the constant section and the entrainment ratio can reach approximately 0.75 for an area ratio of 8, which achieves a good performance of the steam ejector.European Union Horizon 2020Independent Research Fund DenmarkInnovation Fund of DenmarkMAN Energy SolutionsNational Natural Science Foundation of Chin

    Risk factors for sudden cardiac death in hypertrophic cardiomyopathy

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    Aim of this study was the evaluation of six non invasive clinical indices as risk factors for sudden death (SD)in hypertrophic cardiomyopathy (HCM). Previous syncope, family history of SD, non sustained ventricular tachycardia, abnormalblood pressure response during exercise, excessive hypertrophy ≥3 cm and left ventricular outflow tract obstructionwith a peak gradient ≥30 mmHg were evaluated in a cohort of 166 patients(112 males, 51.8 ± 15.6 years), followed up for amedian of 32.4 months (range 1 to 209 months). During follow up 13 patients reached study’s endpoints: SD, cardiac arrest,documented sustained ventricular tachycardia and/or Implantable Cardioverter Defibrillator (ICD)-discharge. Patients havingexperienced syncope or presenting with a Maximum Wall Thickness ≥3cm in echocardiography were more sensitive to SDemergence since they had a 13.07 (95%CI: 4.00-46.95, p < 0.0001) and a 10.07 (95%CI: 2.92-34.79, p = 0.003) greater relativerisk respectively. In our cohort of patients only two of the six ‘recognised’ potential risk factors for SD were found sensitive,a result causing scepticism about the validity of criteria used for ICD implantation in HCM patients for SD prevention

    Accurate and reproducible reconstruction of coronary arteries and endothelial shear stress calculation using 3D OCT: Comparative study to 3D IVUS and 3D QCA

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    Background: Geometrically-correct 3D OCT is a new imaging modality with the potential to investigate the association of local hemodynamic microenvironment with OCT-derived high-risk features. We aimed to describe the methodology of 3D OCT and investigate the accuracy, inter- and intra-observer agreement of 3D OCT in reconstructing coronary arteries and calculating ESS, using 3D IVUS and 3D QCA as references. Methods-Results: 35 coronary artery segments derived from 30 patients were reconstructed in 3D space using 3D OCT. 3D OCT was validated against 3D IVUS and 3D QCA. The agreement in artery reconstruction among 3D OCT, 3D IVUS and 3D QCA was assessed in 3-mm-long subsegments using lumen morphometry and ESS parameters. The inter- and intra-observer agreement of 3D OCT, 3D IVUS and 3D QCA were assessed in a representative sample of 61 subsegments (n ¼ 5 arteries). The data processing times for each reconstruction methodology were also calculated. There was a very high agreement between 3D OCT vs. 3D IVUS and 3D OCT vs. 3D QCA in terms of total reconstructed artery length and volume, as well as in terms of segmental morphometric and ESS metrics with mean differences close to zero and narrow limits of agreement (BlandeAltman analysis). 3D OCT exhibited excellent inter- and intra-observer agreement. The analysis time with 3D OCT was significantly lower compared to 3D IVUS. Conclusions: Geometrically-correct 3D OCT is a feasible, accurate and reproducible 3D reconstruction technique that can perform reliable ESS calculations in coronary arteries

    The fusion approach – applications for understanding local government and European integration

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    The article explores the theoretical capabilities of the fusion approach as a conceptual ‘kit’ to explain the ‘bigger picture’ of European integration from a local government perspective. Fusion addresses the rationales and methods facilitating the transfer of policy-making competences to the European level. It understands European integration as a merging of public resources and policy instruments from multiple levels of government, whereby accountability and responsibilities for policy outcomes become blurred. The article argues that the fusion approach is useful to explain the systemic linkages between macro-trajectories and the corresponding change at the local level; the fusion dynamics of the local and European levels in a common policy-cycle; and the attitudes of local actors towards the EU. Although the article concludes that local government is rather modestly ‘fused’ into the EU, fusion approaches allow examining the extent to which the local level has become integrated into the European governance system

    Implications of serial measurements of natriuretic peptides in heart failure: insights from BIOSTAT‐CHF

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    Riociguat treatment in patients with chronic thromboembolic pulmonary hypertension: Final safety data from the EXPERT registry

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    Objective: The soluble guanylate cyclase stimulator riociguat is approved for the treatment of adult patients with pulmonary arterial hypertension (PAH) and inoperable or persistent/recurrent chronic thromboembolic pulmonary hypertension (CTEPH) following Phase
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