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Implementation of Artificial Intelligence at PK-4 for the Analysis of Complex Plasmas
(2026-03-20) Klein, Max
Complex plasmas serve as a distinctive experimental framework for particle-resolved investigations of strongly coupled many-particle systems under controlled laboratory and microgravity conditions. However, experiments such as the Plasmakristallexperiment-4 generate large image datasets whose analysis is complicated by noise, limited observation times, evolving experimental conditions and inherent ambiguities between ordered and disordered states. Furthermore, the necessity of human intervention during the experiments limits repeatability and is a source of error. This dissertation examines how machine learning methods can be systematically integrated into both the analysis and operation of complex plasma experiments in a physically consistent and computationally efficient manner. The core of this cumulative dissertation comprises three publications that address complementary aspects of particle-resolved data analysis. A convolutional encoder–decoder network is employed to identify string-like particle structures in two-dimensional camera images, with network architecture and training data generation guided by the underlying electrorheological physics. An unsupervised self-organizing map is applied and optimized for robust particle tracking between consecutive frames, enabling reliable trajectory reconstruction in dense and high-velocity particle flows without manual threshold tuning. To further improve data quality, an outlier detection procedure is developed. Based on the particle trajectories, turbulence in complex plasmas is formulated as a time-resolved classification problem and investigated using a long short-term memory network operating on physically motivated, invariant trajectory features. Beyond the individual publications, this work demonstrates the practical deployment of machine learning methods directly at the experiment. The developed models are adapted to embedded hardware through compact network architectures and mixed-precision inference, enabling data analysis with minimal latency implemented into the experiment. In addition, molecular dynamics simulations are analyzed using the machine learning framework, revealing systematic dependencies of turbulent particle motion on simulation parameters. Overall, this dissertation establishes a physically motivated and extensible machine learning framework that advances automated data analysis and diagnostics and supports future adaptive control strategies in complex plasma experiments.
Occurrence and partitioning of selected micropollutants in the Ishmi River Basin, Albania: water treatment under use of low-cost functionalized magneto clay-biochar composites for naproxen, carbamazepine, Cd(II), Cr(VI), and Cu(II) removal
(2026) Peqini, Aleksandër
This cumulative study explores the occurrence, environmental behavior, and removal of heavy metals and pharmaceuticals (belonging to the group of “micropollutants”) through the development of sustainable adsorbents in aquatic systems, with a focus on the Ishmi River basin, Albania. In the first component of this thesis, twelve pharmaceuticals, including caffeine (CAFF), anti-inflammatories (naproxen (NPX), ibuprofen (IBU), and diclofenac (DCF)), antibiotics (anhydro-erythromycin (AETM), azithromycin (ATM), clindamycin (CMC), ciprofloxacin (CFC), erythromycin (ETM), sulfamethoxazole (SMX), and trimethoprim (TMP)), and the antiepileptic carbamazepine (CBZ) were analyzed in surface water and sediment during seasons of the years 2023 and 2024. Highest concentrations occurred near urban areas with limited wastewater treatment, notably at site LR1. Partitioning behavior (Kd, Koc) was significantly influenced by compound-specific (Dow, molecular weight) and sediment-specific (pH, content of organic carbon, CaCO3, and metals) properties, and regression models successfully predicted partition coefficients for NPX, IBU, CFC, AETM, and CMC. In the second component, innovative low-cost magneto-biochar-clay (MBC) composite adsorbents were prepared from the combination of magnetic nanoparticles, biochar (from grape cluster stalk), and feldspar clay and were tested for simultaneously heavy metal removal (Cd(II), Cr(VI), Cu(II)). The MBC 1:2:1 and MBC 1:3:1 showed high adsorption capacities due to enhanced surface area and functional groups. Adsorption was governed by electrostatic interactions and pore filling, with Cr(VI) showing the highest removal efficiency and strong adsorbent reusability over multiple cycles. The third component evaluated the MBC 1:2:1 composite for pharmaceutical removal, specifically NPX and CBZ. The composite demonstrated excellent adsorption performance (≥99% efficiency over five cycles), particularly at low pH values, through electrostatic and hydrophobic interactions. NPX removal remained high (≈93%) even in real Ishmi River water. Overall, the combined findings highlight the influence of environmental and sediment characteristics on pharmaceutical distribution, both the environmental risks posed by pharmaceutical and metal contaminants in under-monitored regions and the effectiveness of MBC composites as sustainable, cost-effective adsorbents for water treatment applications.
Eine biomechanische Analyse verschiedener Sehnenplastiken mit und ohne knotenlosem Nahtsystem zur Versorgung der Achillessehnenruptur
(2026) Bürger, Henry Valentin
Diese biomechanische Studie zeigt, dass eine Verbesserung der Gesamtstabilität erreicht werden kann, ohne zusätzliches Nahtmaterial einzubringen, und auf konventionelle Knoten verzichtet werden kann. Die Kombination von Z-Plastik und dem knotenlosem Nahtsystem „Stratafix“ zeigt sich biomechanisch besonders vorteilhaft in Hinblick auf maximale Kraft, Spannung und Dehnung. Diese Technik ist besonders für Sehnenplastiken relevant, die bei Erkrankungen wie dem kongenitalen Klumpfuß oder bei pathologischer Sehnenverlängerung als Komplikation nach einer Achillessehnenruptur zum Einsatz kommen. Die Technologie mit dem feinen Widerhaken entlang des Verlaufs der Naht ermöglicht eine gleichmäßige Kraftverteilung und reduziert Druckpunkte um die Knoten. Außerdem glänzt die Naht durch eine einfache und schnelle Nahtführung, was besonders bei schlechtem Sehnengewebe oder chronischen Rupturen einen Vorteil darstellen kann. Die Umkippplastik nach Silfverskiöld zeigte mit der Stratafix-Naht vergleichbare Ergebnisse wie mit konventionellem PDS-Nahtmaterial, was für den breiten Einsatz dieser Nahttechnologie spricht. Die Technik sollte jedoch der Versorgung von Rupturen vorbehalten bleiben und nicht zur geplanten Verlängerung einer Sehne eingesetzt werden, da sich hier die Z-Plastik als biomechanisch stabiler erwies. Langfristig könnten diese Erkenntnisse die operative Versorgung von Achillessehnenrupturen und deren Komplikationen verändern. Die Reduktion des Nahtmaterials und der Operationszeit bei einer gleichbleibenden oder sogar erhöhten biomechanischen Stabilität bringt die Vorteile einer schnelleren Rehabilitation und geringerer Kosten. Ein Vorteil, der im modernen Gesundheitssystem nicht wichtiger sein könnte. Weitere biomechanische, tierexperimentelle und histologische Studien sind erforderlich, um die genaue Interaktion der Widerhaken mit dem Sehnengewebe zu untersuchen und auf weitere Nahttechniken anzuwenden. Klinische Studien könnten abschließend die funktionellen Ergebnisse einer Versorgung mit knotenlosen Nahtsystemen untersuchen und die Heilungsqualität bewerten.
Essays on Financial Integration, Inequality, and Geoeconomics
(2026) Yun, Jinyeong
In the first paper, I document empirical evidence indicating that an exogenous capital inflow shock increases income inequality in advanced economies and reduces income inequality in emerging market economies. To examine the effects of capital inflows on income inequality within countries, I estimate a panel structural vector autoregression model with annual data for 53 countries over the period 1990 to 2020. I identify the structural shocks in capital inflows using sign restrictions, thereby distinguishing the exogenous shocks driven by global financial conditions from other shocks. The findings of this paper indicate a remarkable difference in the results between advanced economies and emerging market economies, suggesting that the distributional effects of capital inflows vary depending on the economic conditions in the recipient countries. With respect to income class, a capital inflow shock is primarily associated with an increase in the income share of the high-income class in advanced economies and of the low-income class in emerging market economies. It is necessary for policymakers to pay attention to the distributional effects of capital inflows and to design tailored policy frameworks to address them. The second paper in the dissertation provides novel empirical evidence by examining the impact of financial integration on wage inequality using an unbalanced panel for 20 European countries from 1999 to 2021. Focusing on between-firm wage inequality within industries arising from firm heterogeneity, I find that financial integration (capital flows) increases wage inequality within industries. The effects are more pronounced in the medium term rather than in the short term. The paper then uncovers the underlying mechanism in the distributional effects of financial integration. I show that financial integration shocks widen the capital intensity (the capital-to-labor ratio) gap between firms within industries, which in turn widens the labor productivity gap. This channel allows highly productive, capital-intensive firms to increase wages to a greater extent than small and medium-sized enterprises (SMEs). This proposed channel is further validated by showing that the adverse distributional effects of capital flows are more pronounced in industries with a higher degree of external financial dependence. Finally, while deeper domestic financial markets may play a mitigating role, this effect appears secondary to external financial dependence. Geopolitical risk is commonly associated with adverse outcomes in financial and commodity markets. The third paper shows that the projection of military power in response to geopolitical risk can generate positive financial market responses. We examine the effects of unexpected increases in the presence of the U.S. military in East Asia on asset prices and capital inflows in the region. To this end, we construct a novel index from local newspapers reporting on the presence of U.S. Carrier Strike Groups (CSG) and assess the causal effects of a surprise change in this index on financial markets. Our findings reveal that a higher military presence leads to an increase in stock prices, an appreciation of the local currency, and an inflow of foreign capital. We also document substantial heterogeneity in the effects across geopolitical contexts and U.S. administrations. Market responses are strongly positive when deployments of CSG pertain to North Korean provocations, but muted or even negative when related to tensions with China. Moreover, the expansionary effects disappear or change sign during the first Trump administration, suggesting that the market benefits are tied to overall U.S. strategic policy frameworks. Our findings underscore that the projection of U.S. military power can function as a stabilizing signal for local financial markets, but only under specific geopolitical and institutional conditions.
„Wow. Das sieht groß aus. Und ich bin Teil davon.“ Autoethnografisch-partizipative Forschung untersucht am Beispiel des Kunstprojektes „Über den Brillenrand“
(2026) Schmidt, Anna Julia
In dieser Doktorarbeit werden zwei wissenschaftliche Methoden – Autoethnografie und partizipative Forschung – sowie zwei theoretische Stränge – Organisationsforschung und Projektmanagement – unter ethischer Reflexion zusammengeführt sowie mit eigenen wissenschaftlich fundierten sowie kreativ-innovativen Ideen erweitert. Dadurch wird ein neuer Forschungsstil, die autoethnografisch-partizipative-Forschung (kurz: APF) entwickelt, dieser wird theoretisch dargelegt und praktisch anhand eines durchgeführten Kunstprojektes zu „Gewalt gegen Frauen“ exemplarisch angewendet. Durch diese Doktorarbeit können daher auf gesellschaftlicher und wissenschaftlicher Ebene zentrale Leistungen erbracht werden: Betroffene werden in ihrem Empowerment unterstützt und die Thematik Gewalt gegen Frauen erhält öffentliche Sichtbarkeit. Zudem werden Desiderate im Forschungsbereich „Gewalt gegen Frauen“ behoben und ein Forschungsansatz entwickelt, der auf vielfältige prospektive Forschungsvorhaben adaptiert werden kann.