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NECOC-Verfahren
No full textBeim NECOC-Verfahren wird CO2 aus industriellen Abgasen in einen festen Kohlenstoff umgesetzt
Measurement of air-showers by the radio antennas of the IceCube Surface Array Enhancement
No full textIn a cubic km of ice at the South Pole, strings of Digital Optical Modules of the IceCube observatory measure neutrinos from astrophysical phenomena. IceTop, located on the surface of this detector, comprising 81 pairs of ice Cherenkov detectors measure the electromagnetic and muonic parts of air showers induced by cosmic rays. Challenges arising from the accumulation of snow over these detectors over time led to a planned enhancement of these detectors. Since early 2025, the Surface Array Enhancement has three stations each equipped with 3 antennas and 8 scintillators deployed on the IceTop footprint. The data from the new stations were checked and the first radio data triggered by scintillators measured in all three stations have been reconstructed and verified. Estimation of Xmax with the previous dataset with a single station is also discussed
Testing newly released hadronic interaction models with KASCADE-Grande
No full textKASCADE-Grande was designed to study the energy spectrum and mass composition of cosmic rays in the energy range from 10 PeV up to 1 EeV. The measurements revealed a knee-like structure in the heavy components at energies around 100 PeV, consistent with expectations from rigidity-dependent scenarios. In addition, a spectral hardening was observed in the light component near 120 PeV. With the recent release of updated post-LHC hadronic interaction models - QGSJet-III-01, EPOS.LHC-R, and Sibyll 2.3d - we test their validity using KASCADE-Grande data. In this contribution, we present the reconstructed all-particle energy spectra as well as the energy spectra of individual mass groups derived from shower size observables, using the newly released hadronic interaction models
Anomaly detection in real-time continuous fruit-based monitoring of olive via extensimeter
No full textRechtliche und gesellschaftliche Herausforderungen von Deepfakes
No full textBei Deepfakes handelt es sich um Medieninhalte, die mithilfe von KI-Systemen erzeugt oder manipuliert wurden und die fälschlicherweise einen authentischen Eindruck erwecken. Seit ihrem ersten Aufkommen im Jahr 2017 hat sich die Technologie zu ihrer Erzeugung, vor allem aber ihrer Verbreitung dramatisch entwickelt. In der Folge stellt sich eine Reihe von gesellschaftlichen Herausforderungen, von sexueller Gewalt in Form von nicht-einvernehmlichen, sexualisierten Deepfakes über Betrugsversuche bis hin zu Versuchen politischer Einflussnahme. Dabei bietet die Technologie auch große Potenziale etwa in der Bildung, Kunst, Werbung und Unterhaltung. Die TA-Kompakt-Studie stellt den technischen Stand von Deepfakes, ihre Anwendungen und die Herausforderungen, die mit ihnen einhergehen, übersichtlich und aktuell dar. Ein besonderer Fokus liegt auf der Frage der bisherigen und einer möglichen zukünftigen rechtlichen Regulierung
Identification of Linear Time-Invariant Systems with Dynamic Mode Decomposition
No full textDynamic mode decomposition (DMD) is a popular data-driven framework to extract linear
dynamics from complex high-dimensional systems. In this work, we study the system identification
properties of DMD. We first show that DMD is invariant under linear transformations in the image of the data matrix. If, in addition, the data are constructed from a linear time-invariant system, then we prove that DMD can recover the original dynamics under mild conditions. If the linear dynamics are discretized with the Runge–Kutta method, then we further classify the error of the DMD approximation and detail that for one-stage Runge–Kutta methods; even the continuous dynamics can be recovered with DMD. A numerical example illustrates the theoretical findings
Quarton qubits with stacked Josephson junctions
No full textSuperconducting quantum circuits rely on compact, low-loss inductive elements, strong anharmonicity, and robust flux biasing to realize coherent and controllable quantum bits. This thesis investigates how vertically stacked Josephson junction arrays can be employed to meet these requirements and enable compact flux qubits operated in the quarton regime.
In the first part, stacked Al/AlOx/Al Josephson junctions are established as compact linear inductors. Their three-dimensional geometry reduces parasitic capacitance to ground while allowing multiple junctions to be integrated within a small footprint. A numerical modeling approach is used to quantify stray capacitances, Coulomb screening, and collective modes of extended stacked junction arrays. Cryogenic transport measurements confirm strongly underdamped junction dynamics with uniform junction characteristics, demonstrating their suitability as low-loss inductive elements in superconducting circuits.
In the second part, these inductors are integrated into flux qubits operated in the quarton regime. In this regime, the qubit potential becomes nearly quartic around half-flux bias, resulting in positive anharmonicity and first-order insensitivity to flux noise at the operating point. Spectroscopy reveals qubit transition frequencies in the 3–5 GHz range and anharmonicities of 0.5–1.5 GHz, consistent with the expected quartic potential landscape.
To distinguish intrinsic from externally induced decoherence, a persistent-current bias scheme is implemented, enabling stable and low-noise flux biasing over time scales of up to one week. A direct comparison between conventionally biased and persistently biased devices rules out external flux noise as the dominant coherence-limiting mechanism.
High-resolution spectroscopy identifies avoided level crossings caused by microscopic two-level systems (TLS) in the amorphous tunnel barriers of the stacked junctions. A systematic cumulative analysis of splitting statistics across multiple devices shows that the spectral TLS density scales with the total tunnel-barrier area, while the array length determines the effective qubit–TLS coupling strength. The measured relaxation times follow scaling relations consistent with Fermi’s golden rule for a bath of weakly coupled TLS, demonstrating that TLS in the stacked junction arrays constitute the dominant intrinsic decoherence channel in quarton qubits.
These results establish stacked Josephson junction arrays as compact superinductive elements and provide an understanding of coherence limitations in superconducting quantum circuits based on Josephson junction arrays, offering guidance for future device optimization
Image Log Analyzer Tool (ILAT)
No full textThe Image Log Analyzer Tool (ILAT) is a Python-based application designed for the preprocessing, referencing, visualization, interpretation, and export of image log data. Its workflow is structured through a preprocessing wizard and an advanced dual-view analysis environment that enables detailed picking, classification, and export of structural features from borehole image logs