Technische Universität Dresden: Qucosa
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13. Symposium Experimentelle Untersuchungen von Baukonstruktionen (SEUB)
No full textDas 13. Symposium „Experimentelle Untersuchungen von Baukonstruktionen“ (SEUB) fand am 19. März 2025 in der Messe Dresden statt. Das Tagungsprogramm wartete mit insgesamt 13 Vorträgen zu den Schwerpunkten
- Methoden und Bewertung von Zustand, Tragsicherheit und Restlebensdauer von Bauwerken,
- Zustandsprognose und Monitoring,
- Neue Messverfahren und Digitalisierung sowie
- Aktuelle Bauwerksuntersuchungen
auf. Die Tagung stand unter dem Eindruck der jüngeren Schadensfälle an älteren Spannbetonbrücken. Passend zur Thematik wurden innovative Messmethoden diskutiert, mit denen zukünftig zerstörungsfrei ins Innere von Bauwerken geblickt werden soll. Neue Entwicklungen bei Normen und Richtlinien standen ebenso im Fokus wie die überzeugenden Chancen der vermehrten Nutzung digitaler Werkzeuge und Verfahren. Die Praxisbeispiele zeigten, wie experimentelle Untersuchungen an historischen, aber auch neuen Baukonstruktionen deren (temporären) Betrieb und Erhalt wirkungsvoll unterstützen können.
Das 14. SEUB ist für 2027 geplant.:Schwerpunkt: Digitalisierung
Kristin Kottmeier, Chris Voigt, Martin Schickert, Marat Khairtdinov: Der BIM-Anwendungsfall „digitale Bauwerksdiagnostik“
Sarah Schäfer, Günther Grunert: Wirklichkeitsnahe Eigenfrequenzen mittels moderner Messmethoden und KI-Tools in der Brückendynamik
Andrei Firus, Michael Vospernig, Falk Angermann, Tomás Arana Villafán, Steven Lorenzen: Monitoring von Eisenbahnbrücken im Offenen Digitalen Testfeld des DZSF
Schwerpunkt: Monitoring
Moritz Schäferhoff, Kira Peper, Tina Ambrosat, Christoph Heinze, Daniel Matuszczyk, Frank Weichert, Bettina Brune, Dieter Ungermann, Michael Geist: Sensorgestütztes Monitoring an Stahlbrücken zur prädiktiven Wartung
Ronald Stein, Philipp Metsch, Felix Kaplan, Till Brauer: Bauwerksmonitoring während der Bauarbeiten und den zerstörenden Versuchen am Bauwerk 19.04
Alois Vorwagner, Maciej Kwapisz, Leopold Philip, Vazul Boros, Thomas Moser: Satellitengestütztes Bauwerksmonitoring – Verformungsmessungen an der Großbrücke Schottwien als Demonstrationsprojekt
Marc Gutermann, Susanne Gieler-Breßmer, Uwe Guttenberg: Verlängerung der Restnutzungsdauer von Chlorid- und AKR-geschädigten Parkbauten am Beispiel des Parkhauses am Holstentor in Lübeck
Schwerpunkt: Mesmethoden
Max Fiedler, Peter Deepe, Gregor Schacht, Katarzyna Zdanowicz: Faseroptik und Schallemission bei Spannungsrisskorrosion – eine innovative Anwendung bei einer Spannbetonbrücke in Dresden
Christian Steffes: Kabellose Sensoren zur proaktiven Strukturüberwachung
Sebastian Schulze: Röntgen als Methode für die Bauwerksuntersuchung – neue Entwicklungen und Praxisbeispiele
Schwerpunkt: Bauwerksuntersuchungen
Markus Fischer, Gunter Hahn: Experimentelle Tragsicherheitsbewertung an Spannbeton-Hohlkammerplatten nach einer unplanmäßigen Abweichung vom Sanierungskonzept
Juliane Wagner, Sophie Uhlemann, Alexander Schumann, Sabine Liebelt, Torsten Hampel, Simeon Burkhardt: Belastungsversuche an historischen Decken mit Carbonbetonverstärkung
Jenny Keßler, Conrad Pelka, Steffen Marx: Erhalt von Eisenbahngewölbebrücken durch Belastungsversuch
Organic Electrochemical Transistors - Towards Reliable Electrochemical Sensors and Circuit Technology
No full textThe growing interest in brain-inspired artificial intelligence (AI) is driving a wave of innovation in hardware design, especially with its integration with the Internet of Things (IoT). This endeavor aims to emulate the remarkable functions of the human brain, while overcoming the limitations of traditional computing architectures, such as the von Neumann bottleneck. Achieving this requires a new device concept and new materials to form a new breed of intelligent systems capable of adapting and learning in dynamic environments. Organic Electrochemical Transistor (OECTs) are an emerging class of devices where ions in an electrolyte are used to modulate the electric conduction in a soft organic polymer. This ionic-electronic coupling in OECTs results in a complex time-dependent correlation of signals mimicking effects of synaptic plasticity.
However, OECTs are still a young field of research, and many fundamental questions about ion interactions and device integration need to be answered. This dissertation focuses on OECTs as electronic switches, but also as an ion sensors. Both applications are closely related, as detailed knowledge of ion interactions and double layer capacitance formation is required to build reliable devices and quantitative device models. I will demonstrate the ion sensing performance of OECTs by combining the impedance analysis to determine ion concentration and ion species without ion-selective membranes. In addition to signal amplification and sensing functions, an OECT can operate as an electronic switch to perform complex computations in circuits. The stability and reliability of a single device are the most important prior to circuit integration. Any step in the fabrication process could lead to unreliable device performance. I will investigate the performance of photopatternable solid OECTs fabricated using a photolithography system. Finally, I will introduce a dual-gate device concept in OECTs to tune the threshold voltage from depletion mode to enhancement mode, proving that device engineering can dynamically adjust electrical characteristics without a channel substitution. Combining dual-gate OECTs allows for the creation of a complementary circuit design, which enables the construction of low-power networks specifically suited for edge computing in IoT applications.
This study presents novel insights into the applications of OECTs in discrete biosensors and power-efficient neuromorphic computing. By providing these insights, it not only enhances our understanding of ionic interactions in organic polymers, but also provides practical guidance for implementing innovative solutions in device engineering. Ultimately, these contributions drive the evolution of the IoT toward more efficient and intelligent networks
Morphology, anatomy and sleep movements of Ludwigia sedoides
No full textThe diurnal motion of higher plants, responding to the alternation of day and night, known as nyctinastic movements or “sleep movements”, has been discussed frequently. We present the first description of the circadian rhythm of the water plant Ludwigia sedoides (Humb. & Bonpl.) H.Hara of the family Onagraceae, furthermore its morphology and anatomy. Our results indicate that the plant’s movements are endogenous, although environmental factors certainly have an influence. The majority of plants with nyctinastic leaf movements have a pulvinus, as the crucial part of the plant enabling this movement. Although the basal section of the L. sedoides petiole is not swollen, the tissue functions similarly to a pulvinus. It consists of a central conducting tissue with thick-walled cells, which is surrounded by thin-walled motor cells that can undergo visible shrinking and swelling. Thus, the tissue functionally corresponds to a pulvinus. Examinations of cellular processes, like measurements of the turgor pressure in the petiole, need to be evaluated in future studies
An Active-Inference Approach to Second-Person Neuroscience
No full textSocial neuroscience has often been criticized for approaching the investigation of the neural processes that enable social interaction and cognition from a passive, detached, third-person perspective, without involving any real-time social interaction. With the emergence of second-person neuroscience, investigators have uncovered the unique complexity of neural-activation patterns in actual, real-time interaction. Social cognition that occurs during social interaction is fundamentally different from that unfolding during social observation. However, it remains unclear how the neural correlates of social interaction are to be interpreted. Here, we leverage the active-inference framework to shed light on the mechanisms at play during social interaction in second-person neuroscience studies. Specifically, we show how counterfactually rich mutual predictions, real-time bodily adaptation, and policy selection explain activation in components of the default mode, salience, and frontoparietal networks of the brain, as well as in the basal ganglia. We further argue that these processes constitute the crucial neural processes that underwrite bona fide social interaction. By placing the experimental approach of second-person neuroscience on the theoretical foundation of the active-inference framework, we inform the field of social neuroscience about the mechanisms of real-life interactions. We thereby contribute to the theoretical foundations of empirical second-person neuroscience
Do Goffman Studies Exist?
No full textThe year 2022 commemorates two special events in Erving Goffman's life trajectory: his 100th birthday and the 40th anniversary of his death. Such momentous occasions usually are cause for increased publications in the academic book market, especially for books that are expected to find high resonance. Thus, Michael Hviid Jacobsen and Greg Smith have published a Handbook on Goffman Studies in the renowned Routledge International Handbook series, which currently comprises almost 500 volumes that extend far beyond sociology... [aus dem Beitrag
Ersatzneubau Strombrückenzug Magdeburg
No full textIn der Landeshauptstadt Magdeburg musste infolge des gravierenden Elbehochwassers 2013 ein kompletter Brückenzug notgesichert, neugebaut und saniert werden. In mehr als zehn Jahren Planungs- und Bauzeit wurden innovative sowie nachhaltige Lösungen gefunden, denkmalgerechte Rekonstruktionen realisiert und auch überraschende Sprengstofffunde in Brückenpfeilern eliminiert
Brückenbau mit hohem Vorfertigungsgrad - die Modulbauweise im Praxistest mit dem Ersatzneubau der Elisabethbrücke in Halle (Saale)
No full textEinleitung: Im Rahmen des „Stadtbahnprogramms Halle 25' wurde die Mansfelder Straße, die Halle Neustadt und Halle-Altstadt miteinander verbindet, zu einer zukunftsfähigen Stadtbahnlinie ausgebaut. Bestandteil des Ausbaus ist die Erneuerung der Elisabethbrücke, welche nördlich des Bestandsbauwerkes in verbesserter Linienführung errichtet wird. Neben der Einhaltung der Lichtraumprofile über dem Schifffahrtsprofil der Elisabethsaale war es von entscheidender Bedeutung, alle erforderlichen innerstädtischen Sparten mit dem Neubau des Bauwerkes zu überführen. Diese Aufgabe konnte durch die gewählte Konstruktionsart mit einem integrierten Medienwartungsgang bestens gelöst werden
On asymptotics of least squares estimators in single-node regression trees
No full textThis thesis considers a regression model for two real-valued random variables. Instead of estimating the nonparametric regression function itself, we assume that, according to the quadratic mean, there exists a best approximation among all step functions with a fixed number of jumps, the regression tree.
To estimate the regression tree, we use least squares estimators for its parameters. The main objective is to formulate limit theorems. For this purpose, we analyse the convergence behaviour of the estimators in different cases and observe the corresponding rates, which range from the cube root to one. The rate and limit depends on how the regression function behaves in the neighbourhood of the jumps in the regression tree.
For the results, however, we use and generalise a well-known arginf-CMT for the Skorokhod space and introduce an invariance principle, both of which can also be used in other contexts.:1. Introduction
2. Regression model and least squares estimator
3. Random variables in the multivariate Skorokhod space
4. Change-point problem
5. Split-point problem
6. Simultaneous analysis of change- and split-points
7. Consistency of the estimator
8. An estimator for the optimal number of jumps
A Appendi
Moderat hypofraktionierte Protonentherapie von Prostatakarzinomen: Auswertung bezüglich Effizienz und Nebenwirkungen, im Vergleich zu Photonen
No full textModerately hypofractionated proton beam therapy with implantable retroprostatic spacer in men with localized prostate cancer.:1. Introduction
2. Materials and Methods
3. Results
4. Discussion
5. Limitations and Conclusio
Concrete failure based on a localizing gradient-enhanced damage formulation coupled with plasticity
No full textInvestigations of the mechanical behavior of concrete, including plastic deformability and failure mechanisms, have always been of vital importance. In this work, a modified yield criterion with three surfaces is proposed to capture the plastic yielding behavior under different loading conditions. The failure, that is, the gradual degradation and the final loss of material integrity, can be described through a damage concept. For the purpose of robust finite element (FE) implementations as well as the failure description at an appropriate scale, a localizing gradient-enhanced damage model has been adopted. As such, one obtains mesh-insensitive material responses, while ruling out the unphysical damage broadening observed in conventional gradient-enhanced damage models with a constant regularization length. Following a consistent derivation, the plasticity-damage coupled model is implemented into an in-house FE framework, based on which an experiment-inspired example is simulated to illustrate the capability of the proposed description in concrete modeling, especially the mixed-mode failure. Lastly, the conclusion provides some final insights