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Vorlesungsverzeichnis. Karlsruher Institut für Technologie (KIT). Wintersemester (WS) 2025/26
No full textControlled Synthesis of a New Class of Heterostructured Metal Oxides (Cerium, Thorium, Uranium)/Calcium Fluoride Core‐Shell Nanocrystals With Atomically Coherent Interfaces
No full textHeterostructured nanocrystals (NCs) integrating chemically and/or structurally distinct materials are of significant interest due to their potential to exhibit multiple functionalities or unconventional properties. However, the development of such materials remains limited, primarily due to crystallographic incompatibilities and synthesis challenges. Here, we report the synthesis and structural characterization of a new class of metal oxide-based (Ce, Th, or U) heterostructures with calcium fluoride featuring core-shell architectures with precise control over both morphology and shell thickness. Powder x-ray diffraction (PXRD) and high-resolution scanning/transmission electron microscopy techniques confirm the formation of high-quality single-crystalline particles coupling metal oxide (Ce, Th, or U) and calcium fluoride domains through a structurally coherent but chemically complex intermixed oxide-fluoride interface—an unprecedented observation in cerium and actinide nanochemistry. These novel materials have been designed to anticipate their future doping with therapeutic alpha particle-emitting radionuclides (α-emitters) such as Th or U for locoregional targeted alpha therapy (TAT). It is anticipated that the reported heterostructured core-shell NCs will offer a promising platform for preclinical investigations to determine the full potential and interest of inorganic core-shell NCs,
especially CeO / CaF , for TAT application
„95% des Universums sind unsichtbar“ – Das KIT beteiligt sich an der Jagd nach Dunkler Materie und Dunkler Energie - Campus-Report am 03.03.2026
No full textWir sind tief beeindruckt, wenn wir in klaren Nächten das Funkeln des Sternenhimmels über uns betrachten. Die vielfarbigen Bilder ferner Galaxien, wie sie das James-Webb-Weltraumteleskop aus den Tiefen des Universums liefert, begeistern uns. Und dennoch spielt diese glänzende Welt aus Sternen und Galaxien im Kosmos nur eine winzige Nebenrolle. Was sich dort seit dem Urknall abspielt wird in Wirklichkeit gesteuert durch geheimnisvolle unsichtbare Kräfte. Dunkle Materie und Dunkle Energie machen nach heutigem Wissensstand 95% des Universums aus. Die Leere des Weltraums ist nicht wirklich leer. Eine fieberhafte Suche nach den unsichtbaren Bestandteilen unserer Welt ist gegenwärtig eines der größten Abenteuer der Wissenschaft. Mit gewaltigen Detektoren tief unter der Erde und im ewigen Eis der Antarktis will man Spuren der Dunklen Materie sichtbar machen. Die Dunkle Energie wurde seit 1998 als konstante Kraft für eine unendliche, sich beschleunigende Ausdehnung des Universums verantwortlich gemacht. Neuere Messungen legen jetzt den begründeten Verdacht nahe, dass sich die Dunkle Energie bereits seit einigen Milliarden Jahren abschwächt. Das Standardmodell der Kosmologie ist unter Beschuss geraten
Prompting for the Unknown: Leveraging In-Context-Learning for Few-Shot Open Set Classification
No full textRecognising customer intent is crucial for applications such as chatbots and virtual assistants, requiring accurate interpretation of user inputs. While traditional intent recognition systems depend on large datasets and complex machine learning pipelines, large language models (LLMs) offer competitive performance with significantly less training data through in-context learning (ICL). In this work, we assess the effectiveness of ICL for intent recognition, with a particular focus on detecting out-of-distribution (OOD) inputs. We explore prompting strategies to improve OOD detection and systematically evaluate few-shot classifiers under varying OOD proportions. Our results show that implicit prompting strategies yield better precision for OOD detection, while explicit strategies excel at recall. Moreover, we confirm that LLMs perform comparably to conventional classifiers on in-distribution data. However, a significant fraction of OOD errors are non-overlapping between LLMs and traditional models, highlighting limitations in LLM robustness and suggesting new directions for enhancing generalisation in intent recognition systems
Understanding of floods on regional scale: aggravating pathways, vulnerability, and adaptive capacity – A case study for Oberland Region (Upper Bavaria), Germany
No full textDevelopment of a bioprocess with Streptomyces setonensis to produce a novel herbicidal sugar as an alternative to glyphosate
No full textThe controversial herbicide glyphosate is widely applied to reduce weeds worldwide, to increase agricultural yields to feed the world’s population. Emerging plant resistances and its negative impact on the environment and living beings urge for an effective as well as ecologically acceptable alternative. Streptomyces setonensis, a natural producer strain of such a novel herbicidal substance, seems a promising biocatalyst for the large-scale production of 7–deoxy–sedoheptulose (7dSh). However, this strain has been marginally investigated. Therefore, we developed a microbial production process for 7dSh, systematically optimizing it by investigating essential factors such as medium composition, phosphate and nitrogen limitation, as well as process parameters and modes. Starting on a small scale, the experiments were conducted in a high throughput microbioreactor system (BioLector), in shake flasks employing a Design of Experiments approach and complemented by real–time oxygen transfer measurements with RAMOS® (Respiration Activity MOnitoring System) to gain a deeper understanding of the bacterial metabolism. Elevated osmolarity emerged as a critical factor for 7dSh production. Surprisingly, increased phosphate concentrations enabled an altered metabolism after the growth phase and extended culture longevity, allowing for the application of a feeding strategy. The optimized process was successfully scaled up to a 15 L
Experimental and numerical investigation of non-premixed ammonia flames stabilized on a heated slot burner
No full textStable CoO Nanoscrolls with Outstanding Electrical Properties
No full textLayered CoO is of great interest for its promising properties but is meta-stable in its bulk form. CoO is synthesized by converting the quasi-1D crystal structure of bulk CaCoO via a hydrothermal treatment. The resulting nanostructures are predominantly nanoscrolls with very thin walls, which exhibit long-term stability. A detailed structural investigation reveals that the CoO is found to crystallize in monoclinic form, similar to the related CaCoO-CoO misfit structure. Individual nanoscrolls are characterized electrically and show a p-type semiconducting nature with a high current-carrying capacity of 4·10 A cm and an extremely high breakdown voltage of up to 270 kV cm. The results demonstrate the possibility to stabilize meta-stable materials in low-dimensional forms and a promising application of the nanoscrolls as interconnect in high-voltage electronic circuitry
Tungsten Oxide Mediated Quasi-van der Waals Epitaxy of WS on Sapphire
No full textConventional epitaxy plays a crucial role in current state-of-the art semiconductor technology, as it provides a path for accurate control at the atomic scale of thin films and nanostructures, to be used as the building blocks in nanoelectronics, optoelectronics, sensors, etc. Four decades ago, the terms “van der Waals” (vdW) and “quasi-vdW (Q-vdW) epitaxy” were coined to explain the oriented growth of vdW layers on 2D and 3D substrates, respectively. The major difference with conventional epitaxy is the weaker interaction between the epi-layer and the epi-substrates. Indeed, research on Q-vdW epitaxial growth of transition metal dichalcogenides (TMDCs) has been intense, with oriented growth of atomically thin semiconductors on sapphire being one of the most studied systems. Nonetheless, there are some striking and not yet understood differences in the literature regarding the orientation registry between the epi-layers and epi-substrate and the interface chemistry. Here we study the growth of WS2 via a sequential exposure of the metal and the chalcogen precursors in a metal–organic chemical vapor deposition (MOCVD) system, introducing a metal-seeding step prior to the growth. The ability to control the delivery of the precursor made it possible to study the formation of a continuous and apparently ordered WO3 mono- or few-layer at the surface of a c-plane sapphire. Such an interfacial layer is shown to strongly influence the subsequent quasi-vdW epitaxial growth of the atomically thin semiconductor layers on sapphire. Hence, here we elucidate an epitaxial growth mechanism and demonstrate the robustness of the metal-seeding approach for the oriented formation of other TMDC layers. This work may enable the rational design of vdW and quasi-vdW epitaxial growth on different material systems
Stewart-Platform Six-DoF Haptic Joystick with Force-Feedback via Cartesian Wrench Compensation
No full textThis paper presents the development of a novel six-degree-of-freedom (DoF) force-feedback (FF) joystick, which is designed for controlling large mobile manipulators. We first present the joystick design based on a compact Stewart-platform mechanism to generate motion in all translational and rotational DoF. A computationally efficient closed-form inverse-kinematics formulation is derived, and the necessary forward-kinematics solution is presented. The forward-kinematics solver is implemented on an Arduino-class microcontroller, demonstrating that the approach is suitable for embedded real-time operation. In addition, FF is provided in each DoF to support the operator during manipulation. With our novel compensation scheme, the nonlinearities of the parallel mechanism are addressed to achieve a linear force-displacement characteristic, improving operator comfort. Finally, the proposed joystick is integrated into a human-in-the-loop simulator, and a control mapping is implemented exemplarily. Initial tests demonstrate the approach is feasible and suggest broad utility for future applications