Ensuring product quality while maintaining high productivity and energy efficiency are key aspects and therefore levers for optimization measures in companies. In many sectors, including light metal foundries, data-driven methods based on machine learning are already being used in the context of Industry 4.0 to continuously improve process efficiency. Many studies are focused on analyzing process data during serial production. A holistic, data-based strategy for determining a robust and reliable process design that considers any process fluctuations that occur has not yet been developed for low pressure die casting. This paper therefore presents a novel, automated method for determining a robust and reliable operating point during the development phase of the low pressure die casting process. The focus is on the process parameters for a given casting and mold design but can easily be extended to include design parameters. Within the framework of design of experiments, the procedure includes the needs-based adjustment of the number of experiments as well as compliance with input and output restrictions, the modelling of both static and dynamic system behavior and, within the multi-criteria optimization, the consideration of both uncertainties in the process parameters and uncertainties due to limited metrological accessibility. A selection mechanism, which supports the user in the rapid analysis of robust and reliable Pareto-optimal solutions, rounds off the procedure. The performance is demonstrated using a real low pressure die casting process at MARTINREA HONSEL GERMANY GMBH. The results show that the approach enables a robust and reliable casting process design with comparatively low energy input, considering the boundary conditions of short cycle times.

This dissertation analyzes two-dimensional structures and effects involving Mo, Ta, and S on Au(111), using scanning tunneling microscopy (STM). The structures presented include monolayer dislocation-free concentric lateral heterostructures (CLHs) between MoS2 and TaS2, alloys and a kagome structure. All of these are created utilizing epitaxial growth methods, including a mix of physical vapor and chemical vapor deposition. Physical vapor deposition supplies the transition metals Ta and Mo, and chemical vapor deposition using H2S, supplies the S components. By fine tuning of the growth parameters the differing structures could be realized with precision and consistency. The analyzed CLHs consist of a core of MoS2 and a surrounding envelope of TaS2, which represents a Schottky contact with maximally reduced dimensionality in the z-direction. Structures of this kind are of great interest as model systems for device manufacturing with reduced dimensionalities. While a growth process was already established in previous works, the nature of the interconnection of these two materials, which exhibit a lattice constant mismatch of ∼4.5 %, was left unresolved. This thesis shows that each CLHs presents two types of dislocation-free interfaces, compensating lattice constant mismatch not via dislocations but interface-type dependent deformations. The interface types have been identified from the perviously unknown stacking registries of the CLH with the substrate. These were determined from the distribution of the orientations of CLHs within the hcp- and fcc-stacked areas of the Au(111) substrate, in comparison to free-standing islands of MoS2. Additionally, the edge terminations of the CLHs could be determined from these results. The majority of the deformation was shown to accumulate in the TaS2 envelope. This envelope contracted in both interfaces to match the MoS2 core, which only showed little expansion. In one interface a relaxation of the envelope lattice constant with distance to the interface was observed. Notably, with significant distance, even an extension beyond the equilibrium lattice constant was detected. Empirical potentials and finite elements simulations were performed, showing that most of the effects were explainable by simple mechanics. Modifying the growth process, originally designed to grow CLHs, Mo_(1-x)Ta_(x)S2 alloys were observed. The dependence of alloy formation on the new growth parameters has been analyzed and, utilizing a combination of analysis methods, the ranges of mixtures inside alloys with different growth parameters were estimated. A continuous change from CLHs to alloys with increase in annealing temperature has been found. The investigation of these alloys was further expanded upon by the alteration of the growth process, resulting in the observation of additional structures and variations. Another new structure was discovered as a byproduct of various growth processes. A structure crystallizing in the distinctive kagome lattice, aptly called kagome structure. Topography analysis was used to calculate a first estimation of the lattice constant of the structure. Additionally, a synthesization method to grow large areas of the material was developed. Lastly, Kirkendall holes, the 2D equivalent of the 3D Kirkendall voids, were discovered as a result of the Kirkendall effect. The detection took place after a special growth process which resulted in the formation of Mo_(1-x)Ta_(x)S2 alloys with gradual rates of mixture. Local changes of alloy lattice constants and coverages rates of holes and alloys, in comparison to CLHs, were used to analyze the resulting structures. A model of the growth process was proposed with the help of DFT calculations and a Monte Carlo simulation, showing that the Kirkendall effect can be transferred from 3D to 2D applications.

Die Masterarbeit untersucht die Repräsentation der Marvel-Superheldin Black Widow und deren Entwicklung innerhalb des Marvel Cinematic Universe (MCU) von einer sexualisierten und objektifizierten Nebenfigur zu einer zunehmend selbstbestimmten feministischen Heldinnenfigur. Im Zentrum steht die Frage, wie sich diese Entwicklung über acht Filme und einen Zeitraum von elf Jahren vollzieht und welche Rolle Geschlechterkonstruktionen sowie filmische Blickstrukturen dabei spielen. Auf Grundlage feministischer Filmtheorien zum männlichen und weiblichen Blick sowie theoretischer Ansätze zu Geschlechterstereotypen, Weiblichkeit und weiblichen Figuren im Superheld:innengenre wird die Darstellung Natasha Romanoffs hinsichtlich ihrer Figurenkonstruktion, Körperinszenierung, Kostümierung, Beziehungen, Handlungsmacht und filmischen Inszenierung analysiert. Dabei wird auch die Comicgeschichte der Figur sowie der Produktions- und gesellschaftspolitische Kontext des MCU berücksichtigt. Die Analyse zeigt, dass Black Widows frühe Filmauftritte stark durch den männlichen Blick geprägt sind. Insbesondere in Iron Man 2 (2008) und Marvel’s The Avengers (2012) wird ihr Körper sexualisiert und sie trotz vorhandener Handlungsmacht wiederholt als Objekt männlichen Begehrens inszeniert. Im weiteren Verlauf des MCU nimmt diese Form der Objektifizierung ab, während ihre Charakterentwicklung, Eigenständigkeit und narrative Bedeutung zunehmen. Einen entscheidenden Wandel markiert der Solofilm Black Widow (2021), in dem die Figur stärker als vollständiges, handlungsfähiges und emotional komplexes Subjekt inszeniert wird und sich die filmische Perspektive zunehmend einem weiblichen Blick annähert. Die Arbeit kommt zu dem Ergebnis, dass sich Black Widow innerhalb des MCU von einer sexistisch geprägten Figurenkonstruktion zu einer feministischen Ikone mit fortbestehenden Defiziten entwickelt. Dieser Wandel steht nicht nur für eine Veränderung der Figur selbst, sondern verweist zugleich auf Veränderungen der Geschlechterrepräsentation und der Produktionsbedingungen im Superheld:innengenre. Dabei spielen sowohl gesellschaftliche und feministische Diskurse als auch Veränderungen vor und hinter der Kamera eine wesentliche Rolle.