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Advancing Two-Photon Polymerization For Biofabrication By Employing Diazosulfonate Functionalized Dyes And Their Derivatives As Photoinitiator
No full textXR in Teaching - Roadmap für Extended Reality in der Lehre und Ausbildung an der TU Wien
No full textIm Projekt „XR in Teaching“ wurde an der TU Wien eine Strategie zur Integration von Extended Reality (XR) in die Hochschullehre entwickelt. Ziel war ein einheitliches Konzept, das den Bedürfnissen aller acht Fakultäten gerecht wird. Durch eine umfassende Forschungs- und Analysephase sowie fakultätsübergreifende Workshops wurde die zentrale Herausforderung der inhaltlichen Gestaltung von XR-Anwendungen identifiziert. Um diese Herausforderung zu adressieren, wurde im Wintersemester 2023/2024 eine interdisziplinäre Lehrveranstaltung initiiert, in der Studierende und Lehrende gemeinsam eine XR-Roadmap entwickelten. Das Projekt liefert wertvolle Einblicke in die Potenziale und Herausforderungen von XR in der Hochschullehre und gibt konkrete Empfehlungen für eine nachhaltige Integration an der TU Wie
Quantum key distribution: towards secure communication
No full textThe security of the cryptographic protocols currently used for secure communications relies on the computational difficulty of solving certain mathematical problems, thus characterizing what is known as computational security. In contrast, quantum key distribution (QKD) offers a more fundamental level of security, grounded in the laws of quantum mechanics. However, one of the current challenges is ensuring that practical implementations of QKD strictly match the theoretical idealizations of the protocols. In this article, we present the main results that formalize the security proof of quantum key distribution. We also discuss some of the technical and conceptual challenges involved in incorporating experimental imperfections into security proofs, with the goal of developing protocols that are both practical and secure.A segurança dos protocolos de criptografia utilizados atualmente para comunicações seguras se baseia na dificuldade computacional de resolver certos problemas matemáticos, caracterizando assim a chamada segurança computacional. Em contraste, a distribuição quântica de chaves (DQC) oferece um nível de segurança mais fundamental, baseado nas leis da mecânica quântica. Contudo, um dos grandes desafios atuais é assegurar que as implementações práticas de DQC correspondam às idealizações teóricas dos protocolos. Neste artigo, apresentamos os principais resultados que formalizam a prova de segurança da distribuição quântica de chaves. Além disso, discutimos alguns dos desafios técnicos e conceituais envolvidos na incorporação de imperfeições experimentais às demonstrações de segurança, com o objetivo de desenvolver protocolos que sejam ao mesmo tempo práticos e seguros
Identification of a hydroxycinnamoyl-CoA double bond reductase (HDR) affirms multiple pathways for dihydrochalcone formation in apple
No full textDihydrochalcones are secondary metabolites with manifold dietary and pharmaceutical properties, but with a yet unclear function in plants. The abundance of dihydrochalcones, particularly phloridzin, makes Malus ssp. unique in the plant kingdom. The gene(s)/enzyme(s) for the key reaction in phloridzin biosynthesis, the reduction in the C3-bridge connecting the aromatic rings A and B of chalcones, have long been searched for. To date, two possible pathways to phloridzin have been described, one via the reduction in p-coumaroyl-CoA and the other via the reduction in naringenin chalcone. In this work, an enzyme from apple leaves, which catalyses the reduction in p-coumaroyl-CoA, was purified and partially sequenced. The newly identified hydroxycinnamoyl-CoA double bond reductase (HDR) has not been mentioned in the context of phloridzin biosynthesis so far. Long-read sequencing and sequence analyses in search of transcriptional and translational variants predicted a MdHDR proteoform potentially formed by alternative translational initiation. Heterologous expression of the two HDR proteoforms in E. coli showed that recombinant HDR is able to reduce p-coumaroyl-CoA beside other hydroxycinnamic acid CoA esters, whereas other substrates including the corresponding free hydroxycinnamic acids and naringenin chalcone were not accepted. Heterologous expression of the HDR proteoforms in A. thaliana resulted in the formation of O-hexosylated dihydrocinnamic acids, confirming the functional activity of the HDR as a reductase in planta, but no phloretin derivatives were detected. Our findings support the presence of an alternative pathway to the recently described reduction in naringenin chalcone in the biosynthesis of dihydrochalcones
Electromigration in Gold: Challenges and Possibilities (Invited)
No full textA comprehensive understanding of electromigration at a fundamental level has enabled its application in processing silicon surfaces and forming silicon nanowires. This paper presents state-of-the-art models currently used to enhance the electromigration reliability of metallic interconnects and introduces a novel approach to leveraging these models to study the movement and morphological transformation of gold droplets on silicon substrates. Electromigration-driven gold droplets act as agents in the formation of surface features on silicon, which can be utilized for silicon nanowire processing. The impact of gold droplet size and shape, as well as the applied electrical current density, are accurately predicted by simulations, as demonstrated through comparison with experimental results
Modeling Advanced Magnetoresistive Memories
No full textNonvolatile CMOS-compatible spin-transfer torque (STT) and spin-orbit torque (SOT) magnetoresistive random access memories (MRAMs) possess high speed and endurance as well as long retention compared to their competitors. Advanced MRAM devices are composed of multiple magnetic layers separated by tunnel barriers and nonmagnetic metallic spacers. To efficiently model magnetization dynamics in complex, multilayered structures, we use a coupled spin and charge transport approach, which accurately captures the spin accumulation and the torques acting on ferromagnetic layers. Appropriate boundary conditions at the interfaces are applied to determine the spin and charge transport in metallic spin valves and magnetic tunnel junctions. We demonstrate the versatility of our approach by applying it to evaluate operation in ultra-fast multilayer STT-MRAM, efficient magnetic fieldfree switching in SOT-MRAM with a heavy metal/ferromagnetic SOT stack, as well as a magnetization control in strained noncollinear antiferromagnet Mn3 Sn. By combining an Mn3 Sn layer with a ferromagnetic layer, electrical control over magnetization is achieved, opening perspectives for future field-free SOT-MRAM devices
Neutron capture measurements for s-process nucleosynthesis : A review about CERN n_TOF developments and contributions
No full textThis article presents a review about the main CERN n_TOF contributions to the field of neutron-capture experiments of interest for s-process nucleosynthesis studies over the last 25 years, with a special focus on the measurement of radioactive isotopes. A few recent capture experiments on stable isotopes of astrophysical interest are also discussed. Results on s-process branching nuclei are appropriate to illustrate how advances in detection systems and upgrades in the facility have enabled increasingly challenging experiments and, as a consequence, have led to a better understanding and modeling of the s-process mechanism of nucleosynthesis. New endeavors combining radioactive-ion beams from ISOLDE for the production of radioisotopically pure samples for activation experiments at the new NEAR facility at n_TOF are briefly discussed. On the basis of these new exciting results, also current limitations of state-of-the-art TOF and activation techniques will be depicted, thereby showing the pressing need for further upgrades and enhancements on both facilities and detection systems. A brief account of the potential technique based on inverse kinematics for direct neutron-capture measurements is also presented
Exploring Reinforcement Learning Algorithms for Current Control of Single-Phase AC/DC Full-Bridge Converters
No full textWe discuss a reinforcement learning (RL) algorithm to create a general current control structure for a converter based on a Deep Neural Network (DNN). We discuss an RL algorithm which learns the design of a current controller for a SinglePhase AC/DC Full-Bridge Converter without any pre-calculated training data provided by the user and and/or knowledge about the circuit. No dependencies of the four switching signals are known to the RL algorithm, so it must learn to avoid bridge-leg shorting. The RL algorithm attempts to achieve control with a sinusoidal input current, and optimizes the DNN-based controller for minimum switching losses, minimum low-order harmonics, and low THD of the grid current. We implement this DNNbased controller in a circuit simulator, and analyze controller performance in the time domain