Recent Submissions
Stuttgarter Symposium für Produktentwicklung SSP 2025 : Tagungsband zur Konferenz, Stuttgart, 22. Mai 2025
(Stuttgart : Fraunhofer IAO, 2025) Hölzle, Katharina; Kreimeyer, Matthias; Roth, Daniel; Maier, Thomas; Riedel, Oliver
Mit dem Ziel, nationale und internationale Fachleute unterschiedlicher Disziplinen der Produktentwicklung aus Industrie und Wissenschaft in den Dialog zu bringen, organisiert der Verein zur Förderung produktionstechnischer Forschung e.V. und das Fraunhofer IAO gemeinsam mit dem Institut für Konstruktionstechnik und Technisches Design IKTD, dem Institut für Maschinenelemente IMA und dem Institut für Arbeitswissenschaft und Technologiemanagement IAT der Universität Stuttgart das Stuttgarter Symposium für Produktentwicklung SSP. Am 22. Mai 2025 findet das SSP zum achten Mal statt. Die Konferenz bietet Wissenschaftlern eine Plattform zur Präsentation und Diskussion ihrer neuesten Forschungsergebnisse im Bereich der Produktentwicklung und fördert so den interdisziplinären Wissenstransfer. Aufgerufen waren in der SSP 2025 Beiträge aus folgenden Kategorien: • Adaptive Bedienung für automatisiertes Fahren • Advanced Systems Engineering (ASE) / Model-Based Systems Engineering • Agile Produktentwicklung • Design-Technik-Konvergenz • Digital Engineering • Innovations- und Technologiemanagement • Konstruktionsmethodiken • Leichtbau in der Produktentwicklung • Nachhaltige Produktentwicklung • Nutzerzentriertes Design •Produktkomplexität • Wissensmanagement in der Produktentwicklung • Zuverlässige Produktentwicklung Im Plenum und vier Tracks mit jeweils drei Sessions werden 38 Beiträge präsentiert. Der Abstract der Keynote sowie die 38 Volltexte mit deutschen und englischen Abstracts sind in diesem Band zusammengefasst.
Chronoamperometric investigations on electrochemical synthesis of iron nitrides in molten salt system
(2024) Thiebes, Yannick M.; Engel, Katja; Niewa, Rainer
A systematic investigation of the electrochemical iron nitride synthesis in a LiCl/KCl salt melt at 723 K shows an optimum of ϵ-Fe 3N 1+xformation in the range of 2.2 to 2.3 V and for γ′-Fe 4N between 2.4 and 2.5 V enabling the control of the desired iron nitride phase by setting the supplied terminal voltage. The product formation of iron nitrides starts when the electrochemical window is reached, which could be verified by linear sweep voltammetry. Hence, a maximum of nitrogen content in the formed iron nitride phases is observed for 2.27 V. During elongated synthesis periods, convection emerges as the predominant transport mechanism hindering an accelerated reaction rate with higher overpotential applied. Real-time analysis of the background current allows conclusions about the remaining nitride concentration. Additionally, there is concurrent iron nitride formation at the electrode surface through nitride adsorption and autonucleation-induced precipitation of iron and nitride ions. The analysis of the amount of sediment in comparison to the layer thickness of the nitrided working electrode suggests that the autonucleation mechanism dominates over the adsorption mechanism with increasing overpotential and can be further enhanced by this feature.
Agent-based principal strips modeling for freeform surfaces in architecture
(2024) Chai, Hua; Orozco, Luis; Kannenberg, Fabian; Siriwardena, Lasath; Schwinn, Tobias; Liu, Hanning; Menges, Achim; Yuan, Philip F.
The principal curvature (PC) of a freeform surface, as an important indicator of its fundamental features, is frequently used to guide their rationalization in the field of architectural geometry. The division of a surface using its PC lines into principal strips (PSs) is an innovative way to break down a freeform surface for construction. However, the application of PC networks in architectural design is hindered by the difficulty to generate them and flexibly control their density. This paper introduces a method for PS-based reconstruction of freeform surfaces with different umbilical conditions in the early stages of design. An agent-based modeling approach is developed to find the umbilics and increase the degree of control over the spacing of PC lines. This research can effectively expand the application range of PS-based surface reconstruction methods for freeform architectures.
Reproducing kernel Hilbert spaces cannot contain all continuous functions on a compact metric space
(2024) Steinwart, Ingo
Given an uncountable, compact metric space X, we show that there exists no reproducing kernel Hilbert space that contains the space of all continuous functions on X .
Reduced-dimensional modelling for nonlinear convection-dominated flow in cylindric domains
(2024) Mel’nyk, Taras; Rohde, Christian
The aim of the paper is to construct and justify asymptotic approximations for solutions to quasilinear convection-diffusion problems with a predominance of nonlinear convective flow in a thin cylinder, where an inhomogeneous nonlinear Robin-type boundary condition involving convective and diffusive fluxes is imposed on the lateral surface. The limit problem for vanishing diffusion and the cylinder shrinking to an interval is a nonlinear first-order conservation law. For a time span that allows for a classical solution of this limit problem corresponding uniform pointwise and energy estimates are proven. They provide precise model error estimates with respect to the small parameter that controls the double viscosity-geometric limit. In addition, other problems with more higher Péclet numbers are also considered.
Properties of application-relevant microemulsions : influence of short-chain alkanes, pressure and bio-based block copolymers
(2024) Krappel, Maximilian; Sottmann, Thomas (Prof. Dr.)
Co-modulation of TNFR1 and TNFR2 in an animal model of multiple sclerosis
(2023) Fiedler, Timon; Fairless, Richard; Pichi, Kira; Fischer, Roman; Richter, Fabian; Kontermann, Roland E.; Pfizenmaier, Klaus; Diem, Ricarda; Williams, Sarah K.
BackgroundTumour necrosis factor (TNF) is a pleiotropic cytokine and master regulator of the immune system. It acts through two receptors resulting in often opposing biological effects, which may explain the lack of therapeutic potential obtained so far in multiple sclerosis (MS) with non-receptor-specific anti-TNF therapeutics. Under neuroinflammatory conditions, such as MS, TNF receptor-1 (TNFR1) is believed to mediate the pro-inflammatory activities associated with TNF, whereas TNF receptor-2 (TNFR2) may instead induce anti-inflammatory effects as well as promote remyelination and neuroprotection. In this study, we have investigated the therapeutic potential of blocking TNFR1 whilst simultaneously stimulating TNFR2 in a mouse model of MS.MethodsExperimental autoimmune encephalomyelitis (EAE) was induced with myelin oligodendrocyte glycoprotein (MOG35-55) in humanized TNFR1 knock-in mice. These were treated with a human-specific TNFR1-selective antagonistic antibody (H398) and a mouse-specific TNFR2 agonist (EHD2-sc-mTNFR2), both in combination and individually. Histopathological analysis of spinal cords was performed to investigate demyelination and inflammatory infiltration, as well as axonal and neuronal degeneration. Retinas were examined for any protective effects on retinal ganglion cell (RGC) degeneration and neuroprotective signalling pathways analysed by Western blotting.ResultsTNFR modulation successfully ameliorated symptoms of EAE and reduced demyelination, inflammatory infiltration and axonal degeneration. Furthermore, the combinatorial approach of blocking TNFR1 and stimulating TNFR2 signalling increased RGC survival and promoted the phosphorylation of Akt and NF-κB, both known to mediate neuroprotection.ConclusionThese results further support the potential of regulating the balance of TNFR signalling, through the co-modulation of TNFR1 and TNFR2 activity, as a novel therapeutic approach in treating inflammatory demyelinating disease.
Epidemiology of football injuries of the German Bundesliga : a media-based, prospective analysis over 7 consecutive seasons
(2023) aus der Fünten, Karen; Tröß, Tobias; Hadji, Abed; Beaudouin, Florian; Steendahl, Ida Bo; Meyer, Tim
Background. This study describes the implementation of a standardised, prospective injury database covering the entire 1st male German football league (“Bundesliga”) based on publicly available media data. For the first time, various media sources were used simultaneously as the external validity of media-generated data was low in the past compared to data obtained by way of the “gold standard”, i.e. by the teams’ medical staffs.
Methods. The study covers 7 consecutive seasons (2014/15-2020/21). The primary data source was the online version of the sport-specific journal “kicker Sportmagazin™” complemented by further publicly available media data. Injury data collection followed the Fuller consensus statement on football injury studies.
Results. During the 7 seasons, 6653 injuries occurred, thereof 3821 in training and 2832 in matches. The injury incidence rates (IRs) per 1000 football hours were 5.5 [95% CI 5.3-5.6], 25.9 [25.0-26.9] per 1000 match, and 3.4 [3.3-3.6] per 1000 training hours. Twenty-four per cent of the injuries ( n = 1569, IR 1.3 [1.2-1.4]) affected the thigh, 15% ( n = 1023, IR 0.8 [0.8-0.9]) the knee, and 13% ( n = 856, IR 0.7 [0.7-0.8]) the ankle. Muscle/tendon injuries contributed 49% ( n = 3288, IR 2.7 [2.6-2.8]), joint/ligament injuries 17% ( n = 1152, IR 0.9 [0.9-1.0]), and contusions 13% ( n = 855, IR 0.7 [0.7-0.8]). Compared to studies using injury reports from the clubs’ medical staff, media data revealed similar proportional distributions of the injuries, but the IRs tended towards the lower end. Obtaining specific locations or diagnosis especially with regard to minor injuries is difficult.
Conclusions. Media data are convenient for investigating the quantity of injuries of an entire league, for identifying injuries for further subanalysis, and for analysing complex injuries. Future studies will focus on the identification of inter- and intraseasonal trends, players' individual injury histories, and risk factors for subsequent injuries. Furthermore, these data will be used in a complex system approach for developing a clinical decision support system, e.g. for return to play decisions.
Cognitive, physical and emotional determinants of activities of daily living in nursing home residents : a cross-sectional study within the PROCARE-project
(2023) Wollesen, Bettina; Schott, Nadja; Klotzbier, Thomas; Bischoff, Laura Luise; Cordes, Thomas; Rudisch, Julian; Otto, Ann-Kathrin; Zwingmann, Katharina; Hildebrand, Claudia; Jöllenbeck, Thomas; Vogt, Lutz; Schoene, Daniel; Weigelt, Matthias; Voelcker-Rehage, Claudia
Background. Interdependencies of health, fitness, cognition, and emotion can promote or inhibit mobility. This study aimed to analyse pathways and interactions between individual subjective and objective physical performance, cognition, and emotions with activities of daily living (ADLs) as mobility indicators in multimorbid nursing home residents.
Methods. The study included n = 448 (77.1% females, age = 84.1 ± 7.8 years) nursing home residents. To describe the participant's demographics, frailty, number of falls, and participating institutions' socioeconomic status (SES) were assessed. ADLs were measured with the Barthel Index (BI; dependent variable). Independent variables included objective physical performance, subjective physical performance, cognition, and emotions. A structural equation model (SEM) with maximum likelihood estimation was conducted with AMOS. Direct and indirect effects were estimated using standardized coefficients (significance level of 0.05).
Results. Indices showed (Chi 2 (148) = 217, PCMIN/DF = 1.47; p < .001; Comparative Fit Index = .940; Tucker Lewes Index = .902, RMSEA = .033) that the model fitted the data adequately. While there was no direct association between emotions, subjective physical performance, and ADLs, objective physical performance and cognition predicted higher ADLs (p < .01). Emotions had a strong relationship with subjective physical performance, and cognition had a moderate relationship with objective physical performance.
Discussion and conclusion. Objective performance and cognition predicted higher functional status, as expressed by higher BI scores. ADLs, such as mobility, dressing, or handling tasks, require motor and cognitive performance. Subjective performance is an important predictor of ADLs and is only partly explained by objective performance, but to a large extent also by emotions. Therefore, future interventions for nursing home residents should take a holistic approach that focuses not only on promoting objective physical and cognitive performance but also on emotions and perceived physical performance.
Generalized Clausius inequalities in a nonequilibrium cold-atom system
(2023) Mayer, Daniel; Lutz, Eric; Widera, Artur
Thermodynamic inequalities, such as the Clausius inequality, characterize the direction of nonequilibrium processes. However, the latter result presupposes a system coupled to a heat bath that drives it to a thermal state. Far from equilibrium, the Clausius inequality can be generalized using information-theoretic quantities. For initially isolated systems that are moved from an equilibrium state by a dissipative heat exchange, the generalized Clausius inequality is predicted to be reversed. We here experimentally investigate the nonequilibrium thermodynamics of an initially isolated dilute gas of ultracold Cesium atoms that can be either thermalized or pushed out of equilibrium by means of laser cooling techniques. We determine in both cases the phase-space dynamics by tracing the evolution with position-resolved fluorescence imaging, from which we evaluate all relevant thermodynamic quantities. We confirm the validity of the generalized Clausius inequality for the first process and of the reversed generalized Clausius inequality for the second transformation.