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Current research on aquifer thermal energy storage (ATES) in Germany
No full textThis paper reviews the current research on aquifer thermal energy storage (ATES) and mine thermal energy storage (MTES) in Germany providing descriptions of 3 low-temperature ATES (LT-ATES), 8 high-temperature ATES (HT-ATES), and 2 MTES research sites. While the overview reveals a diverse field of investigations spanning various spatial scales, research objectives, and methodologies, the predominant focus is limited to early-stage research with low technology readiness levels (TRL). The high number of HT-ATES research sites suggests greater research interest compared to LT-ATES. The integration of ATES into district heating (DH) grids in particular is a prominent research focus, yet almost none of the projects are specifically intended for practical implementation. Future research should therefore prioritize real-world demonstration projects and identify key locations, which is crucial for showcasing the benefits of ATES. The need for a streamlined regulatory framework that addresses environmental risks and ensures installation quality and efficient permit procedures is also discussed
Detection of production relevant deviations in paint sprays
No full textSpray painting is still a poorly manageable process due to the complex interaction of physical, chemical and environmental influences like turbulent air flows, strong electrostatic fields, complex viscosity of paints and paint booth conditions. Consequently, many important properties of the painted film, like thickness, color, surface structure and the efficiency of the process are not controllable in an adequate manner, despite the enormous economic ramifications of poor quality control in high volume applications, such as in the automotive industry. This study shows how novel, online spray monitoring can instantaneously generate characterizing quantities from the spray to detect harmful deviations in the process. In this study, several minute changes have been experimentally imposed on a paint system, such as changed paint viscosity or pigmentation, deviations in air flow and paint flow rates, and defective or used and worn equipment parts. It will be shown that all these deviations lead to features which allow a clear distinction from the intact and reference cases. Additionally, it is shown that most of the deviations, if not detected, would have led to quality issues of the paint coating
When do prevocational programs ease the transition to vocational education and training?
No full textPreparing youth for the transition from school to work is a key labor market challenge in many countries. Across Europe, there are many educational pograms to improve youth’s school-to-work transitions. In Germany, youth with difficulties in their school-to-work transitions are channeled into prevocational programs to help them to enter vocational education and training (VET), which serve as an entry into the labor market. Using data drawn from the National Educational Panel Study (NEPS; N = 1,282 participants of prevocational programs), we (1) examined youth’s transition trajectories after their attendance of a first prevocational program and (2) how using institutional resources such as internships during the first prevocational program supports youth’s transitions to VET. Our findings of sequence and cluster analysis showed that approximately two-thirds of the participants had largely stable transitions to VET (i.e., transitions with a low risk of dropout), although many of these transitions were delayed by one year after leaving their first prevocational program. In contrast, one-third of the participants had at-risk transition trajectories and were at risk of being permanently excluded from the education and employment system. By conducting a multinomial logistic regression, we also found that attending long internships and attaining a higher school certificate during the first prevocational program was associated with a smooth transition to VET programs, and both factors "protected" youth from encountering difficult pathways with very low prospects of reaching VET programs after leaving prevocational programs. Moreover, mentoring during prevocational programs and the perceived degree to which the programs helped youth to form occupational aspirations were also associated with a lower probability of facing at-risk transition trajectories
Waldemar Petersen - Eine Biografie
No full textWer nach Darmstadt kommt, um hier zu studieren oder zu arbeiten, begegnet dem Namen von Waldemar Petersen (1880 – 1946) auf vielfältige Weise. So trug beispielsweise die Hauptverkehrsstraße, die auf den Standort lichtwiese der TU Darmstadt führt, über Jahrzehnte den Namen Petersenstraße, benannt nach Waldemar Petersen. Es gibt auch eine in den 1950er Jahren gegründete Waldemar-Petersen-Stiftung mit Sitz in Darmstadt, die das 1929 erbaute Erholungsheim in Hirschegg im Kleinwalsertal unterhält. Seit 2011 ist der Autor Geschäftsführer dieser Stiftung
Identifying productivity-limiting factors in progressive die stamping: data-driven methodology for process optimization
No full textManufacturing products in multi-stage forming processes through blanking, deep-drawing and bending operations with progressive dies is one of the most economically relevant processes in the sheet metal forming industry and allows for complex geometries. In order to be able to ensure a reliable operation of the tools, manufacturers choose stroke speed conservatively, which limits the productivity and profitability. For this reason, this paper describes which productivity-limiting factors affect multi-stage forming processes and how machine learning in combination with explainable artificial intelligence methods can be used to identify and counteract productivity-limiting factors. By equipping the processes with multiple sensors, stroke rate-dependent anomalies can be detected at an early stage and countermeasures can be derived proactively, thus making the process more reliable and ensuring product quality. The methodology developed is demonstrated using two use cases which show that vibrations and friction in a progressive die are significantly reduced
An object numbering task reveals an underestimation of complexity for typically structured scenes
No full textOur visual environments are composed of an abundance of individual objects. The efficiency with which we can parse such rich environments is remarkable. Previous work suggests that this efficiency is partly explained by grouping mechanisms, which allow the visual system to process the objects that surround us as meaningful groups rather than individual entities. Here, we show that the grouping of objects in typically and meaningfully structured environments directly relates to a reduction of perceived complexity. In an object numerosity discrimination task, we showed participants pairs of schematic scene miniatures, in which objects were structured in typical or atypical ways and asked them to judge which scene consisted of more individual objects. Critically, participants underestimated the number of objects in typically structured compared with atypically structured scenes, suggesting that grouping based on typical object configurations reduces the perceived numerical complexity of a scene. In two control experiments, we show that this overestimation also occurs when the objects are presented on textured backgrounds, and that it is specific to upright scenes, indicating that it is not related to basic visual feature differences between typically and atypically structured scenes. Together, our results suggest that our visual surroundings appear less complex to the visual system than the number of objects in them makes us believe
40 Jahre Richtfest Maschinenbauhallen auf der Lichtwiese
No full textAm 17. April jährte sich das Richtfest der Versuchshallen für den Fachbereich Maschinenbau auf dem Erweiterungsgebiet Lichtwiese zum 40. Mal. Bereits 1970 hatte das Staatliche Hochschulbauamt Darmstadt dort mit dem Bau des neuen Institutsgebäudes begonnen, dem sich die Hallen und Laboratorien im rückwärtigen Bereich anschließen
SurGrID: controllable surgical simulation via Scene Graph to Image Diffusion
Full text linkPurpose: Surgical simulation offers a promising addition to conventional surgical training. However, available simulation tools lack photorealism and rely on hard-coded behaviour. Denoising Diffusion Models are a promising alternative for high-fidelity image synthesis, but existing state-of-the-art conditioning methods fall short in providing precise control or interactivity over the generated scenes.
Methods: We introduce SurGrID, a Scene Graph to Image Diffusion Model, allowing for controllable surgical scene synthesis by leveraging Scene Graphs. These graphs encode a surgical scene’s components’ spatial and semantic information, which are then translated into an intermediate representation using our novel pre-training step that explicitly captures local and global information.
Results: Our proposed method improves the fidelity of generated images and their coherence with the graph input over the state of the art. Further, we demonstrate the simulation’s realism and controllability in a user assessment study involving clinical experts.
Conclusion: Scene Graphs can be effectively used for precise and interactive conditioning of Denoising Diffusion Models for simulating surgical scenes, enabling high-fidelity and interactive control over the generated content
Augusto Varnesi (1866 - 1941)
Full text linkBildhauer, Plakettenstecher, Modelleur und Professor – eine interessante Kombination und beispielhaft für das vielfältige Wirken und Schaffen des am 02.02.1866 – also vor 150 Jahren – in Rom geborenen Giulio Cesare Augusto (Agosto) Varnesi. Als Sohn eines Bildhauers lag es für Augusto nahe, seiner kreativen Berufung zufolgen
The Impact of PEO and PVP Additives on the Structure and Properties of Silk Fibroin Adsorption Layers
Full text linkMaterials formed with a base of silk fibroin (SF) are successfully used in tissue engineering since their properties are similar to those of natural extracellular matrixes. Mixing SF with different polymers, for example, polyethylene oxide (PEO) and polyvinylpyrrolidone (PVP), allows the production of fibers, hydrogels, and films and their morphology to be controlled. The impact of PEO and PVP on formation and structure of SF adsorption layers was studied at different was studied at different polymer concentrations (from 0.002 to 0.5 mg/mL) and surface lifetimes. The protein concentration was fixed at 0.02 and 0.2 mg/mL. These concentrations are characterized by different types of spontaneously formed structures at the air–water interface. Since both synthetic polymers possess surface activity, they can penetrate the fibroin adsorption layer, leading to a decrease in the dynamic surface elasticity at almost constant surface tension and a decrease in ellipsometric angle Δ and adsorption layer thickness. As shown by AFM, the presence of polymers increases the porosity of the adsorption layer, due to the possible arrangement of protein and polymer molecules into separate domains, and can result in various morphology types such as fibers or tree-like ribbons. Therefore, polymers like PEO and PVP can be used to regulate the SF self-assembly at the interface, which in turn can affect the properties of the materials with high surface areas like electrospun matts and scaffolds