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Preisstabilität in Deutschland in Zeiten von D-Mark und Euro
No full textMit der Abschaffung der D-Mark und der Einführung des Euro waren Hoffnungen verbunden,
aber auch Befürchtungen, dass die neue Währung nicht so stabil wie die D-Mark sein könnte.
Die D-Mark gehörte international über 50 Jahre zu den zwei Währungen mit den niedrigsten
Inflationsraten. In diesem Beitrag wird die Entwicklung der Preise und der Kaufkraft in
Deutschland in zwei gleich langen Perioden vor und nach der Euro-Einführung verglichen. Der
Euro weist dabei sogar geringere durchschnittliche Inflationsraten, gemessen an den
Verbraucherpreisen in Deutschland, als die D-Mark auf. In den Jahren 1999 bis 2020 herrschte
weltweit ein günstigeres Inflationsumfeld, was es auch der Europäischen Zentralbank (EZB)
leichter machte, ihr Preisstabilitätsziel zu verfolgen. Die ersten schweren Herausforderungen
ergaben sich für die EZB seit 2021, als die Inflationsrate aufgrund negativer Angebotsschocks
und einer beispiellosen Fiskalexpansion auf über 10% anstieg. Die Deutsche Bundesbank
konnte in ähnlichen Krisen in den 1970er Jahren mit einer konsequenten Stabilitätspolitik den
Preisauftrieb deutlich stärker und nachhaltiger bekämpfen als die meisten anderen Länder.
Ein Erfolg, zu dem auch ihr hoher Grad der Unabhängigkeit von der Politik beitrug. Ob dies der EZB gelingt, bleibt abzuwarten. Anfang 2025 liegt die Inflationsrate im Euroraum und in
Deutschland trotz einer tiefgreifenden Konjunkturschwäche mit 2,5% noch immer über dem
Inflationsziel von 2%
Konzeption eines Astronomie-Besucherexperiments für das Deutsche Röntgen Museum
No full textDas Deutsche Röntgen Museum in Remscheid ist eine weltweit einzigartige Institution, die das Leben und Werk des ersten Physik Nobelpreisträgers Wilhelm Conrad Röntgen und die Auswirkungen seiner Entdeckung der Röntgenstrahlung erforscht und dokumentiert Als integraler Bestandteil des Museums bietet das Museumslabor RöLab die Möglichkeit, durch eigene Experimente praktische Erfahrungen zu verschiedenen Themen rund um Röntgenstrahlung, Optik und Technik zu sammeln Im Rahmen eines gemeinsamen Entwicklungsprojekts konzipieren Studierende der TH Aschaffenburg derzeit ein Besucherexperiment zur astronomischen Röntgenoptik für das Museumslabor Das neue Besucherexperiment soll nach seiner Realisierung junge Forscherinnen und Forscher für die faszinierende Welt der Röntgenoptik und der Röntgenastronomie begeistern
In situ high-speed milling and thermal post-processing for the optimization of fatigue behaviour of additive-manufactured IN718 components
No full textWe report on the optimization of tensile properties and fatigue behaviour of Laser Powder Bed Fusion (PBF-LB/M)-built IN718 components employing an innovative hybrid additive-subtractive technology and various heat treatments. The hybrid approach comprises PBF-LB/M with in situ high-speed milling. Double Ageing, solution and ageing treatment, as well as Hot Isostatic Pressing are used to improve ultimate tensile strength and endurance limit. As a result, the advantages of the hybrid-machined components are clearly demonstrated by their improved mechanical properties. These enhanced properties are associated to changes in microstructure, which are identified as precipitations of IN718. Furthermore, crack initiation and crack growth for high cycle numbers as well as sudden fractures are determined
Polydopamine Coatings for Enhanced Soft X-Ray Reflectivity in Space Telescope Mirrors
No full textIt has been known for years that sputtered low-density coatings deposited under vacuum (e.g. carbon or B4C), applied on top of high-density metallic coatings, can enhance their reflectivity in the soft X-ray band (below ~5 keV). However, the physical deposition techniques, as vacuum-based sputtering, to produce B4C or amorphous coatings are usually difficult and highly costing. Polydopamine (PDA), a bio-polymer inspired by mussels, exhibits exceptional surface binding and it’s nowadays a popular material used in surface engineering for multipurpose applications (Ryu, 2018). PDA thin film are typically produced in aqueous solution by the oxidative polymerization of dopamine, commonly known as one of the “hormones of happiness”, resulting in nanometric PDA coating with tunable thickness and morphology. In recent years, we have introduced and investigated a novel and scalable strategy for enhancing the soft X-ray reflectivity of telescope mirrors used in space missions based on dip-liquid deposition of PDA thin films as carbon-rich coating (carbon 62.7 %wt. in DA monomer) (Cotroneo, 2022). This method is very versatile and quick and offers a low-cost alternative to conventional carbon-like coating, while maintaining or even exceeding performance in the energy range below ~5 keV. Experimental tests across three X-ray beamlines—including two synchrotron facilities—demonstrated consistent reflectivity enhancement, especially in the 1–4 keV energy range and with a good match between theoretical predictions and experimental reflectivity profiles. When applied over traditional coatings (e.g Au, Ir), the dip-liquid overcoats produced improvements of up to 100% in effective area for some specific X-ray bands compared to conventional single-metal films. These results are particularly compelling for nickel-replicated mirrors with gold coatings, a common architecture in cost-sensitive space missions.
Bibliography
Cotroneo, V., 2022. Dopamine dip-liquid overcoatings for soft x-ray reflectivity enhancement.
SPIE Proceedings.
Ryu, J. H., 2018. Polydopamine Surface Chemistry: A Decade of Discovery.
ACS Applied Materials & Interfaces
Design Guide for Hybrid-Additive Manufacturing of Inconel 718 Combining PBF-LB/M and In Situ High-Speed Milling
No full textAs the correlation between design rules and process limitations is of the upmost importance for the full exploitation of any manufacturing technology, we report a design guide for hybrid-additive manufacturing of Inconel 718. Basic limitations need to be evaluated for this particular hybrid approach that combines laser powder bed fusion (PBF-LB/M) and in situ high-speed milling. Fundamental geometric limitations are examined with regard to the minimum feasible wall thickness, cylinders, overhanging structures, and chamfers. Furthermore, geometrical restrictions due to the integrated three-axis milling process with respect to inclinations, inner angles, notches, and boreholes are investigated. From these findings, we derive design guidelines for a reliable build process using this hybrid manufacturing. Additionally, a design guideline for the hybrid-additive manufacturing approach is presented, depicting a step-to-step guide for the adjustment of constructions. To demonstrate this, a powder nozzle for a direct energy deposition (DED-LB/M) process is redesigned following the previously defined guidelines. This redesign encompasses analysis of the existing component and identification of problematic areas such as flat angles, leading to a new construction that is suitable for a hybrid-additive manufacturing approach
Influence of in-situ high-speed milling within a hybrid additive manufacturing approach on the fatigue behaviour of Inconel 718 lattice structures
No full textAs lattice structures in various designs are used in additive manufacturing for lightweight components, the mechanical characterisation and fracture behaviour is of upmost importance for their industrial application. In this study, the fatigue behaviour of Inconel 718 lattice structures is evaluated, comparing sole PBF-LB/M to a hybrid additive manufacturing process combining PBF-LB/M with in-situ high-speed milling. At first, the static and dynamic mechanical load behaviour of different packing densities is analysed, determining the compressive strength and the endurance limit. Secondly, hybrid additive manufactured components are compared to PBF-LB/M built parts with respect to these mechanical properties, revealing improved compressive properties and modified regimes of fatigue. In addition, differences in fracture behaviour are qualified by fractographic and surface analysis. Overall, it can be summarized that the mechanical load characteristics, especially the fatigue behaviour, are improved for hybrid additively manufactured components with a superior surface quality of Ra < 1 µm
Evaluation of the Impact of Heat Treatment Processes and Surface Conditions on the Mechanical Properties of PBF-LB/M-Built Inconel 718 Components
No full textA study of the mechanical properties of hybrid additive manufactured IN718 components is presented, optimising mechanical properties due to an in-situ high-speed milling and different heat treatment processes. At first, the impact of different heat treatment processes is investigated, as the changes in microstructure during the process lead to different mechanical properties. Static and dynamic mechanical load behaviour is tested, quantifying microstructural changes by means of the Ultimate Tensile Strength (UTS) and the endurance limit. Furthermore, sole PBF-LB/M- and hybrid built components are compared, investigating the effect of a surface finish on the static and dynamic load behaviour, as superficial cracks and melting errors diminish the UTS and the endurance limit of PBF-LB/M-built components. Within these experiments, a change of fatigue behaviour for the heat-treatedstates can be observed, compared to the as-built state of the PBF-LB/M, as the development of different phases during heat treatment leads to an improvement of the endurance limit for, e.g., solution and ageing treated components. Additionally, the improvement of the surface quality to Ra = 2 µm leads to a significant increase of the dynamic mechanical load behaviour of hybrid-built components, as superficial cracks and surface defects are reduced
„Zirkus UNI-versum” - ein Astronomie-Event für Schulklassen
No full textIm “Wissenschaftsjahr 2023 – Unser Universum”, einer gemeinsamen Initiative des Bundesministeriums für Bildung und Forschung (BMBF) und Wissenschaft im Dialog (WiD), wurden zahlreiche Projekte in ganz Deutschland gefördert. Eines dieser Projekte war der “Zirkus UNI-versum”, der an der Technischen Hochschule Aschaffenburg stattfand. Zielgruppe waren Schulklassen von benachbarten Schulen, die eingeladen wurden, bei einem Besuch auf dem Hochschul-Campus spielerisch Wissen über Astronomie und Raumfahrt zu sammeln. Gleichzeitig sollen mit dem Projekt (und anderen „Erlebnis-Bausteinen“ unserer Schulprojekte) die Schülerinnen und Schüler für MINT-Fächer begeistert und zukünftige Studierende für technische Studiengänge gewonnen werden