On the unsteady formation of secondary flow inside a rotating turbine blade passage

This paper addresses the unsteady formation of secondary flow structures inside a turbine rotor passage. The first stage of a two-stage, low-pressure turbine is investigated at a Reynolds Number of 75,000. The design represents the third and the fourth stages of an engine-representative, low-pressure turbine. The flow field inside the rotor passage is discussed in the relative frame of reference using the streamwise vorticity. A multistage unsteady Reynolds-averaged Navier–Stokes (URANS) prediction provides the time-resolved data set required. It is supported by steady and unsteady area traverse data acquired with five-hole probes and dual-film probes at rotor inlet and exit. The unsteady analysis reveals a nonclassical secondary flow field inside the rotor passage of this turbine. The secondary flow field is dominated by flow structures related to the upstream nozzle guide vane. The interaction processes at hub and casing appear to be mirror images and have characteristic forms in time and space. Distinct loss zones are identified, which are associated with vane-rotor interaction processes. The distribution of the measured isentropic stage efficiency at rotor exit is shown, which is reduced significantly by the secondary flow structures discussed. Their impacts on the steady as well as on the unsteady angle characteristics at rotor exit are presented to address the influences on the inlet conditions of the downstream nozzle guide vane. It is concluded that URANS should improve the optimization of rotor geometry and rotor loss can be controlled, to a degree, by nozzle guide vane (NGV) design

Omega-3 and -6 fatty acid plasma levels are not associated with liver cirrhosis-associated systemic inflammation

Background: Liver cirrhosis is associated with profound immunodysfunction, i.e. a parallel presence of chronic systemic inflammation and immunosuppression, which can result in acute-on-chronic liver failure (ACLF). Omega-3 fatty acids are precursors of pro-resolving mediators and support the resolution of inflammation. Objective: The aim of this study was to determine plasma levels of omega-3 fatty acids in patients with liver cirrhosis and ACLF. Methods: Patients with liver cirrhosis with and without ACLF were enrolled in a prospective cohort study and analyzed post-hoc for the present sub-study. Clinical data and biomaterials were collected at baseline and at day 7, 28 and after 3 months of follow-up. Plasma concentrations of arachidonic acid (ARA) and docosahexaenoic acid (DHA), which represent key omega-6 and -3 fatty acids, respectively, were quantified and associated with markers of systemic inflammation and severity of liver cirrhosis. Results: A total of 117 patients were included in the present analyses. Of those, 26 (22.2%), 51 (43.6%) and 40 (34.2%) patients had compensated or decompensated liver cirrhosis, and ACLF. Plasma levels of ARA and DHA were similar in patients with compensated cirrhosis, decompensated cirrhosis, and ACLF. Furthermore, no significant association between plasma ARA or DHA and C-reactive protein or peripheral blood leukocytes were observed (P>0.05). Conclusion: In our study plasma levels of key omega-3 and omega-6 fatty acid are neither associated with the severity of liver cirrhosis nor with liver-cirrhosis-associated systemic inflammation

Neue Techniken zur Kompostierung. Verwertung auf landwirtschaftlichen Flaechen. Teilvorhaben: 10.b T. 1. Naehrstofffreisetzung bei der Kompostierung und Vergaerung Abschlussbericht

Available from TIB Hannover: F99B1588 / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEBundesministerium fuer Bildung und Forschung (BMBF), Bonn (Germany)DEGerman