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Studies on upscaled bifunctional catalysts and their mutual interactions in direct CO2 hydrogenation to DME
No full textIn the present work, the direct synthesis of dimethyl ether (DME) from CO2 and H2 was investigated as a central focus for CO2 valorisation. The two-part reaction requires a bifunctional catalyst, which consists of a CO2 hydrogenation catalyst for MeOH formation and a dehydration catalyst for DME formation.A CuO/ZnO/ZrO2 (CZZ) system was used as the hydrogenation catalyst. The synthesis of CZZ was successfully scaled up by a factor of 7 in this work, enabling a synthesis of 35 g CZZ per day. Several BRØNSTED-acidic zeolites (H-ZSM5_93, H-ZSM5_440, H-FER_20, H-MOR_32, H-BEA_25, H-SAPO_11) were screened as dehydration catalysts in various mixtures. In addition, literature-known tungstosilicic acid-coated Al2O3 and ZrO2 (HPA@Al and HPA@Zr) were used as dehydration catalysts.In a project funded by the Federal Ministry of Education and Research (BioDME project), a transportable synthesis station was designed and put into operation. The best systems from the screening (H-ZSM5_93, H-FER_20 and HPA@Al) were further analysed in this reactor. The systems showed high CO2 conversions (approx. 24 %) and DME selectivities (approx. 60 %).Depending on the mixture method, some dehydration catalysts (H-FER_20, H-MOR_32) showed strong variations in their DME productivity while others showed no dependencies. Therefore, surface tests were performed to investigate the changes of the dehydration catalysts when mixed with CZZ. The investigations revealed a weakening of the strong-acid sites. However, no direct correlation with the DME activity could be identified.Due to the high material costs of CZZ, an in-house developed, fluorinated CuO/ZnO/MgO (CZMg-F) was investigated in direct DME synthesis. The results showed partially higher DME selectivities for CZMg-F. In general, the successful upscaling of the CZZ synthesis provided enough raw material for the operation of a new synthesis station. This made it possible to investigate bifunctional catalyst systems with high CO2 conversions. Furthermore, different methods were investigated to better understand the interaction between hydrogenation catalyst and dehydration catalyst.In addition, CZMg-F was successfully established as a MeOH-forming component in the direct DME synthesis
La faticaccia sta nei dettaglietti - Suffigierte Substantive des Italienischen in der Übersetzung: eine vergleichende Analyse zwischen Italienisch, Deutsch und Englisch in den parallelen InterCorp-Korpora und eine Bestandsaufnahme der übersetzerischen Fähigkeiten künstlicher Intelligenz
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German Cardiac Society comments on the guidelines of the ESC (2024) on the management of atrial fibrillation : from the Committee for Clinical Cardiovascular Medicine
No full textStatuen und visuelle Kommunikation im Ionien archaischer Zeit
No full textIm Griechenland archaischer Zeit (ca. 700–480/470 v. Chr.) beginnt die Erfolgsgeschichte eines Bildmediums, dessen hauptsächliche Aufgabe in der dauerhaften Repräsentation seiner Stifter lag: Statuen aus Marmor hatten aufgrund ihrer Größe und dreidimensionalen Ausarbeitung, jedoch auch dank der Härte ihres Produktionsmaterials die Fähigkeit, die körperliche Präsenz des Dargestellten zu suggerieren. Sie boten damit eine visuelle Kommunikationsleistung an, die anderen, kleineren oder flach gearbeiteten Bildern fehlten.Die vorliegende Studie untersucht die ausschließlich über die lokalen Eliten geführte 'Kommunikation mit Statuen' im Ionien archaischer Zeit, wo die Resonanz auf das neue Repräsentationsmedium schon im frühen 6. Jh. v. Chr. groß war. Ziel der Untersuchung ist ein Verständnis der Werte, der sozialen und kulturellen Konventionen und der Diskurse, die mit dem Medium der groß- und rundplastischen Marmorstatue an verschiedenen Bildtypen und in diachroner Perspektive bis in das späte 6./frühe 5. Jh. v. Chr. verhandelt wurden
The low-friction and viscous detachments drive deformation on Mars
No full textIntroductionThe Tharsis region on Mars represents one of the most prominent volcanic and tectonic provinces in the Solar System, shaped over the past four billion years through sustained magmatic and tectonic activity [1]. The prevailing hypothesis attributes the formation of Tharsis to a long-lived mantle plume beneath a relatively thin lithosphere [2,3]. Alternative models propose a superplume origin [4] or invoke a combination of isostatic uplift, lithospheric flexure, volcanic loading, and intrusive thickening [5,6]. Simulations have been employed to test these hypotheses and explore variations in crustal thickness and mantle flow [7,8], while geological and structural observations support the presence of plume-induced stress centers that have governed the development of step-like topographic decreases from the center outward and the formation of compressional landforms [9,10].A key manifestation of this tectonic evolution is the widespread system of compressional landforms called “wrinkle ridges”, which encircle the Tharsis rise and extend into the Northern Plains. These landforms, typically several hundred meters in height and tens of kilometers in width, are best preserved around Syria, Thaumasia, and Lunae Planum [11]. Their morphology, spacing, and radial distribution suggest a genetic link to underlying detachment and a link with Tharsis uplift. Their formation remains debated due to limited subsurface data, with hypotheses ranging from fault-propagation folding to blind thrusting over detachments [12–13]. In several regions, wrinkle ridges display regular spacing that decreases with distance from the Tharsis center, particularly between Sinai Planum and Solis Dorsa [14].This study investigates (i) the mechanical connection between circumferential compressional features and large-scale detachment and (ii) the influence of detachment rheology—frictional versus viscous—on stress transfer within wedge-shaped topography. These questions are addressed using two-dimensional thermomechanical models driven by gravitational forces arising from isostatic and volcanic loading, in the absence of external tectonic boundary conditions.MethodologyPrimary datasets were sourced from NASA’s Planetary Data System (PDS) and the Mars Global GIS repository. Topographic profiles were extracted from the MOLA-HRSC blended digital elevation model at 200 m/pixel resolution [15]. THEMIS daytime infrared mosaics (~100 m/pixel) [16] were used as the base for identifying circumferential wrinkle ridges [17]. We applied the Swath Profiler Toolbox [18] to derive average topographic cross-sections within 1,500 km-wide swaths focused on well-preserved wrinkle ridges. Features overprinted by Amazonian-era resurfacing were excluded from analysis.Numerical simulations were performed using a finite-difference thermo-mechanical code [19,20] based on a marker-in-cell approach, which couples a fixed Eulerian grid with freely advected Lagrangian markers. Governing equations for conservation of mass, momentum, and energy were solved on a static grid, while the fourth-order Runge-Kutta method was used to update marker positions. Our domain consisted of an 8 km-thick sticky-air layer above a 7 km-thick upper crustal unit characterized by a quartzite rheology. Below this, a 2 km-thick mechanically weak detachment layer was introduced, implemented either as low-frictional (fluid-overpressured shale) or low-viscosity (salt). The base of the crust comprised an 8 km-thick megaregolithic layer modeled using dry olivine flow laws. Detachment depths were validated by the shallow seismic profiles of the InSight mission [20]. We conducted 60 exploratory runs to probe the parameter space and selected 10 representative models for detailed analysis. For the frictional case, mobile shale detachment zones were simulated under fluid overpressure ratios from 0.7 to 0.99. In viscous cases, the salt layer viscosity was varied from 10¹⁷ to 10¹⁹ Pa·s.Results and ConclusionOur numerical modeling reveals distinct behaviors for low-frictional versus viscous detachments. Specifically, for the wedge structure, notably low alpha and beta angles imply that the mechanically homogeneous wedge requires an exceptionally low friction coefficient to match the gravity-driven geometry. This supports the presence of a low-friction detachment, potentially shale, possibly activated by fluid overpressure. Simulations with an initial overpressure of 0.7 show no deformation, with localization beginning only beyond a threshold of 0.85. Between 0.85 and 0.99, proximal normal faulting is followed by deformation in a transmission zone and the formation of a distal thrust front. In contrast, viscous detachment models—representing salt with a viscosity of ~10⁷ Pa·s—produce diapiric upwellings, with normal faults shifting from radial to offset configurations, indicating unstable wedge deformation. When viscosity increases to 10⁸ Pa·s, the detachment transmits stress from the Tharsis uplift without localized diapirism, aligning best with observed topography.Here, we propose that the presence of such low-friction detachment is likely linked to alteration of pyroclastic materials, and a viscous detachment, particularly around Tharsis, and in the Valles Marineris region, may be attributed to previously suggested [22] chlorite-based hydrothermal alteration processes. This mechanism could plausibly reduce both the frictional strength and viscosity of the detachment zone, thereby facilitating the observed tectonic features
Therapygenetics: serotonin transporter gene polymorphism (5-HTTLPR) is associated with behavioral treatment response to virtual exposure therapy in patients with spider phobia
No full textA comparison of health policies, public opinion and vaccination rates in France and Germany
No full textObjectivesFrance and Germany have different approaches towards childhood immunisation. The aim of this study was to determine the similarities and differences between France and Germany in terms of heath policies, vaccination rates and public opinion as far as infant vaccinations were concerned.Study designLiterature review.Subject and methodsWe used the databases of the Robert Koch Institute (RKI) and of Santé publique France (SpF) to compare the vaccination rates of children in the year 2017. The state of public opinion was principally assessed by comparing data from SpF and the German Federal Center for Health Education (BZgA).ResultsVaccination rates were higher in French pre-school children in 2017 for the hexavalent and anti-pneumococcal vaccines, whereas Measles–Mumps–Rubella and anti-meningococcal vaccination rates were higher in Germany. Public opinion was more favourable towards vaccines in Germany than in France. Some vaccines, especially against seasonal influenza and hepatitis B, were viewed with criticism in France, whereas German parents considered hepatitis B immunisation to be important for their children. Moreover, both countries showed higher immunisation rates in northern regions. This correlated with the state of vaccine confidence in France. In Germany, eastern regions were more favourable towards vaccines, which correlated with higher immunisation rates in these regions.ConclusionsThe state of vaccine confidence seemed to correlate with immunisation rates in both countries. The need for information about vaccines is still high in both countries and trust in the medical community as well as in the immunisation policymakers should be reinforced as a priority
Stochastic partial differential equations and invariant manifolds in embedded hilbert spaces
No full textWe provide necessary and sufficient conditions for stochastic invariance of finite dimensional submanifolds for solutions of stochastic partial differential equations (SPDEs) in continuously embedded Hilbert spaces with non-smooth coefficients. Furthermore, we establish a link between invariance of submanifolds for such SPDEs in Hermite Sobolev spaces and invariance of submanifolds for finite dimensional SDEs. This provides a new method for analyzing stochastic invariance of submanifolds for finite dimensional Itô diffusions, which we will use in order to derive new invariance results for finite dimensional SDEs
