The continuous δ-γ transformation during cooling of ferritic-austenitic iron-chromium-nickel alloys

Following previously published isothermal TTT diagrams, continuous TTT diagrams for the δ-γ transformation of a series of different iron-chromium-nickel-alloys containing 23.0–35.0 Cr and 6.45–15.6 Ni are presented. The microstructures and transformation behaviors indicate the same nucleation and growth process as in the isothermal reactions. The critical upper cooling rate for complete undercooling of the δ-γ transformation decreases with increasing chromium- and decreasing nickel contents.     

Einfluß des Gefüges auf die mechanischen Eigenschaften von Gußeisen mit rd. 3% C und 14% Cr für Walzen

Ermittlung der mechanischen Eigenschaften unterschiedlicher Bereiche gegossener Walzen mit 360 mm Ballendurchmesser und 200 mm Zapfendurchmesser aus drei Schmelzen eines Gußeisens mit rd. 3% C, 0,8% Si, 0,8% Mn, 0,14% P, 0,014% S, 14,2% Cr, 0,35% Mo und 0,5% Ni in zwei Wärmebehandlungszuständen. Zahlenmäßiger Zusammenhang zwischen der Biegefließgrenze und geeigneten Kennwerten für den Gefügezustand unter Bezugnahme auf die Beanspruchungsrichtung. Einfluß des Gefügezustandes auf das Formänderungsverhalten im statischen Biegeversuch.     

Einfluß der chemischen Zusammensetzung und der Abkühlungsbedingungen auf den Gefügezustand von Gußeisen mit rd. 3% C und 14% Cr für Walzen

Abguß von drei Walzenkörpern aus verschleißfestem Gußeisen mit 2,95 bis 3,16% C, rd. 0,8% Si, rd. 0,8% Mn, rd. 0,14% P, rd. 0,014% S, rd. 14% Cr, rd. 0,35% Mo und rd. 0,5% Ni. Abkühlgeschwindigkeit nach dem Abguß. Rechnerische Ermittlung der chemischen Zusammensetzung und der Mengenanteile der sich ausscheidenden Gefügebestandteile. Metallographische Gefügeuntersuchungen. Abstand der Sekundärarme der Mischkristalldendriten sowie Länge und Dicke der Carbidteilchen als Kenngrößen zur zahlenmäßigen Gefügebeschreibung. Einfluß der Abkühlungsbedingungen auf den Zustand des Primär- und des Sekundärgefüges.     

δ-γ phase equilibria in iron-rich iron-chromium-nickel alloys at temperatures between 1200 and 1350 °C

The δ-γ phase equilibria of iron-rich iron-chromium-nickel alloys with 23 to 38% Cr, 7 to 22% Ni are established at temperatures between 1200 and 1350 °C. The effect of chemical compositions and annealing temperatures on equilibrium δ ferrite fraction is discussed.     

S-Adenosyl-l-Methionine Salvage Impacts Psilocybin Formation in “Magic” Mushrooms

Psychotropic Psilocybe mushrooms biosynthesize their principal natural product psilocybin in five steps, among them a phosphotransfer and two methyltransfer reactions, which consume one equivalent of 5′-adenosine triphosphate (ATP) and two equivalents of S-adenosyl-l -methionine (SAM). This short but co-substrate-intensive pathway requires nucleoside cofactor salvage to maintain high psilocybin production rates. We characterized the adenosine kinase (AdoK) and S-adenosyl-l -homocysteine (SAH) hydrolase (SahH) of Psilocybe cubensis. Both enzymes are directly or indirectly involved in regenerating SAM. qRT-PCR expression analysis revealed an induced expression of the genes in the fungal primordia and carpophores. A one-pot in vitro reaction with the N-methyltransferase PsiM of the psilocybin pathway demonstrates a concerted action with SahH to facilitate biosynthesis by removal of accumulating SAH.     

Influence of base material,tempered condition and hardening pattern on the residual stress profile of induction hardened gears

Forschung im Ingenieurwesen - This paper discusses influences of the base material, pre-heat treatment and hardening pattern on the residual stresses of induction hardened gears with module 2 and...     

DRAG REDUCTION IN ARTIFICIALLY ROUGHENED PIPES

The influence of an extremely rough surface on the drag reducing properties of polymer solutions is studied by pressure drop measurements in a rough pipe. It is shown that the onset of drag reduction for a homogeneous dilute polymer solution in a rough pipe occurs at the same wall shear stress as in a smooth pipe of the same diameter. In addition, the maximum drag reduction is almost the same in both types of pipes. Similar results are found for so-called heterogeneous drag reduction obtained by injecting a concentrated polymer solution in the centre of the pipe. The injected polymer solution, which is convected along the centre of the pipe as an elastic thread, disintegrates into fine polymer threads in the rough pipe leading to an increased drag reduction. In this case the injection of the same amount of polymer in the form of a concentrated solution is more effective than a homogeneous polymer solution.     

Cytomegalovirus infection and coronary heart disease: results of a german case-control study

This case-control study investigated whether previous infection with cytomegalovirus (CMV) was associated with coronary heart disease (CHD). In total, 312 patients of German nationality aged 40-68 years who had a coronary stenosis of >50% of the luminal diameter were recruited for study. Controls (n=479) were voluntary blood donors. CMV serology was performed to determine presence of specific CMV antibodies (IgG, IgM, IgA ELA test; Medac, Hamburg, Germany). Rheologic and inflammatory markers were determined. The prevalence of specific IgG antibodies against CMV was 54.5% in cases and 49.9% in controls (P=.116). The odds ratio for CHD was 1.21 (95% confidence interval, 0.84-1.75) given a positive serostatus of specific IgG antibodies after adjustment for covariates. With the exception of C-reactive protein in controls, none of the rheologic or inflammatory markers was associated with CMV serostatus. Thus, serologic evidence of previous infection with CMV was not a major risk factor for CHD in this population.