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Experimentelle Untersuchungen zum Oberflächenabfluss auf natürlichem Grünland bei Starkregen
No full textSearch for low-mass electron-recoil dark matter using a single-charge sensitive SuperCDMS-HVeV detector
No full textWe present constraints on low-mass dark matter electron scattering and absorption interactions using a SuperCDMS high-voltage eV-resolution (HVeV) detector. Data were taken underground in the NEXUS facility located at Fermilab with an overburden of 225 meters of water equivalent. The experiment benefits from the minimizing of luminescence from the printed circuit boards in the detector holder used in all previous HVeV studies. A blind analysis of 6.1 g·days
of exposure produces exclusion limits for dark matter-electron scattering cross sections for masses as low as 1 MeV/2, as well as on the photon-dark photon mixing parameter and the coupling constant between axionlike particles and electrons for particles with masses >1.2 eV/2 probed via absorption processes
BWR Severe Accident Uncertainty and Sensitivity Analysis in the Framework of the IAEA CRP I31033
No full textTritium Exposure and Decontamination: The TED Facility
No full textOzone was used at the Tritium Laboratory Karlsruhe (TLK) for the first time for the decontamination of parts of the KATRIN experiment. The observed high decontamination efficiency led to the question of how to use ozone as an efficient cleaning tool for other facilities operated at TLK for years with tritium. To answer this question, we built the Tritium Exposure and Decontamination (TED) facility, where standard decontamination measures (purging, bake-out) can be quantitatively compared to the ozone method. To quantify the amount of ozone, and hence, the decontamination efficiency, we developed tritiumcompatible in-line ozone sensors, which are presented alongside the TED facility and first results. A first series of tritium exposure at substantial tritium amounts (≈28 bar·h) and decontamination campaigns was performed using industrial-grade stainless steel, copper, and aluminum as sample materials, and applying ozone and conventional decontamination strategies. The first results have indicated that ozone as a cleaning agent alone is not sufficient for tritium removal, and if possible, a bake-out is the most effective and least waste gas intense method. The ultimate goal of the TED facility is the development of a “plug-in” ozone generator suited for deployment in various facilities to achieve, e.g. the reduction of residual tritium in analytical systems or as a fast-acting cleaning tool prior to opening contaminated vacuum systems for modification and/or dismantling
PINNs4Drops: Video-conditioned physics-informed neural networks for two-phase flow reconstruction (Research Data)
No full textTwo-phase flow phenomena underpin critical technologies such as hydrogen fuel cells, spray cooling, and combustion, where droplet dynamics govern performance and efficiency. Conventional optical diagnostics, including shadowgraphy and particle image velocimetry, provide valuable insights but are limited to two-dimensional projections of inherently three-dimensional flows. We employ a specialized optical technique that encodes droplet surface information through color-coded glare points, enabling enhanced reconstruction of gas-liquid interfaces. To interpret these measurements, we introduce video-conditioned physics-informed neural networks VcPINNs, which integrate experimental observations with governing fluid dynamics equations. This hybrid framework leverages the strengths of both data-driven learning and physical constraints, allowing accurate volumetric flow reconstruction from limited input images. Applied to droplet impingement experiments, our method yields highly resolved and physically consistent 3D interface and flow dynamics. The combined imaging and PINN reconstruction strategy provides a powerful platform for advancing multiphase-flow analysis, with broad potential impact across energy, cooling, and propulsion applications
Data Study Group Final Report: Johnson Matthey - Data Driven Modelling of Chemical Processes: Towards Flexible Production of Energy Carriers for a Net-Zero Society
No full textData Study Groups are week-long events at The Alan Turing Institute bringing together some of the country’s top talent from data science, artificial intelligence, and wider fields, to analyse real-world data science challenges.
Johnson Matthey (JM), an FTSE 250 company, is a global leader in speciality chemicals and sustainable technologies with a 200+ year history of using advanced metals chemistry to tackle the world’s biggest challenges. JM continually seeks to expand on products and services which provide sustainability benefits through the positive impact they have on the environment, resource efficiency and human health. For instance, JM are interested in various new manufacturing processes that help build a sustainable society, such as power-to-X, power-to-fuels, and green hydrogen processes. This challenge mainly pertains to the flexible operation of these processes: we seek to understand how they can be operated with a time-changing feedstock such as electricity.
Data Study Group - December 2023 | The Alan Turing Institut
COVARIANCE ESTIMATION USING h-STATISTICS IN MONTE CARLO AND MULTILEVEL MONTE CARLO METHODS
No full textWe present novel Monte Carlo (MC) and multilevel Monte Carlo (MLMC) methods to determine the unbiased covariance of random variables using h-statistics. The advantage of this procedure lies in the unbiased construction of the estimator\u27s mean square error in a closed form. This is in contrast to conventional MC and MLMC covariance estimators, which are based on biased mean square errors defined solely by upper bounds, particularly within the MLMC. The numerical results of the algorithms are demonstrated by estimating the covariance of the stochastic response of a simple 1D stochastic elliptic PDE such as Poisson\u27s model
Inter-User Interference Analysis in a Point-to-Multipoint Sub-THz Wireless Communication Link
No full textThis paper presents the analysis of the inter-user interference (IUI) in a multiuser wireless link operating in the sub-THz frequency range of 270 GHz to 330 GHz. The link utilizes an optoelectronic transmitter (Tx) comprising two integrated external cavity lasers with a wide tuning range, a broadband electro-optic modulator, and a uni-traveling carrier photodiode with a WR3.4 output. A conformal lens-integrated WR3.4 frequency beam-steering antenna transmits the signal to seven users distributed in space. At the user side, an electronic sub-THz receiver is used for the wireless link. A finite portion of the Rx bandwidth (270 GHz to 330 GHz) is allocated to each user. The power ratio between the individual user channels is experimentally evaluated in three different test scenarios, operating at carrier frequencies of 290 GHz, 300 GHz, and 310 GHz, respectively. This evaluation is based on the frequency response analysis of the optoelectronic Tx, the electronic Rx, and the radiation characteristics of the frequency beam-steering antenna. To the best of our knowledge, this work presents the first IUI analysis in a sub-THz wireless link operating over a distance of 10 m, with a record high gross aggregated data rate of 140 Gbps across seven users. A worst-case power ratio of -2.5 dB between adjacent channels and an average power ratio of -11.3 dB is observed, highlighting the potential of sub-THz communication for high-data-rate multiuser networks
