Publications Repository - Helmholtz-Zentrum Dresden-Rossendorf

We presetnt a method to compute a static exchange-correlation (XC) kernel across temperature regimes using KS-DFT for any XC functional available in Libxc [1]. We show the results of the static exchange-correlation kernel analysis using various XC functionals for dense electron gas and warm dense hydrogen. The results allow to better understund the effect of thermal excitations and density inhomogeneity on the XC kernel. Based on a comparison of KS-DFT data with high-precision Quantum Monte Carlo (QMC) data for both high temperatures and the ground state, we present the results of the analysis of the accuracy of the commonly used XC functionals for warm dense matter simulations [1-4]. As an application of the static XC kernel, we discuss linear-response time-dependent density functional theory (TDDFT) approach to warm dense matter with adiabatic exchange--correlation kernels [5].

The exchange correlation kernel (XC) naturally arises within the framework of linear response theory as a key quantity for describing correlated systems of many particles. Particularly, the XC kernel is needed in linear response TDDFT (LR-TDDFT), which is a powerful ab initio method that
allows one to describe dynamical and transport properties of equilibrium quantum-many body systems. A standard approach of the calculation of the XC kernel in LR-TDDFT is based on the computation of the second order functional derivative of a XC functional with respect to density. For extended systems, this approach is limited to simple static (adiabatic) LDA and GGA (such as PBE ) level XC functionals due to mathematical and computational challenges of computing functional derivatives of meta-GGA and hybrid level functionals. In fact, only adiabatic LDA (ALDA) is available in commonly used open source DFT codes. We have overcome these limitations by developing a new method of the calculation of the XC kernel [1], which utilizes the method of a direct harmonic perturbation. The essence of the developed approach is to compute a static density response function of a system by measuring the density perturbation induced by an external static harmonic field; with density being extracted from an equilibrium KS-DFT simulation. An alternative and equivalent definition of the XC kernel as a difference between the inverse values of the density response functions of systems with non-zero and zero XC functionals allows us to access the XC kernel without explicitly computing functional derivatives. This allows one to compute the XC kernel using available XC functionals through the ranks of Jacob's ladder and for any temperature. We demonstrated the utility of this method by analyzing the XC kernel beyond GGA level including meta-GGA and hybrid XC functionals [1-3]. In addition, we have presented a workflow for using the static XC kernel from the direct perturbation approach in the
LR-TDDFT of warm dense matter [4].

[1] Zhandos Moldabekov, Maximilian Böhme, Jan Vorberger, David Blaschke, and Tobias
Dornheim, Ab Initio Static Exchange–Correlation Kernel across Jacob’s Ladder without Functional
Derivatives, Journal of Chemical Theory and Computation 19 (4), 1286-1299 (2023 )
[2] Zhandos A. Moldabekov, Mani Lokamani, Jan Vorberger, Attila Cangi, Tobias Dornheim,
Assessing the accuracy of hybrid exchange-correlation functionals for the density response of warm
dense electrons. J. Chem. Phys. 158 (9), 094105 (2023).
[3] Zhandos A. Moldabekov, Mani Lokamani, Jan Vorberger, Attila Cangi, and Tobias Dornheim,
Non-empirical Mixing Coefficient for Hybrid XC Functionals from Analysis of the XC Kernel, The
Journal of Physical Chemistry Letters 14 (5), 1326-1333 (2023)
[4] Zhandos A. Moldabekov, Michele Pavanello, Maximilian P. Böhme, Jan Vorberger, and Tobias
Dornheim, Linear-response time-dependent density functional theory approach to warm dense
matter with adiabatic exchange-correlation kernels, Phys. Rev. Research 5, 023089 (2023)

To improve postoperative monitoring of patients undergoing pancreatic surgery, we propose a bedside, droplet-based millifluidic device that facilitates near real-time accurate and rapid determination of drain amylase activity. Drain liquid is co-encapsulated with a starch substrate in multiple nanoliter-sized reactors to track the fluorescence intensity released upon reaction with amylase. Comparing the amylase levels of 32 patient samples, 31 out of 32 millifluidic system results (96.9%) matched the clinical data within the 95% confidence interval. Importantly, the new millifluidic strategy significantly reduces the amylase assay time from several hours to approximately 3-4 minutes and offers a ca. 10 times lower limit of detection of 0.007 µmol/sL compared to that of current clinical techniques. Finally, we for the first time demonstrate the possibility of dynamic monitoring of amylase levels in the patient samples. Thus, the proposed droplet-based instant assay system could augment state-of-the-art clinical methods and significantly improve diagnosis of postoperative complications in patients after pancreatic surgery via near-real-time bedside monitoring.

Oncology research has been an exciting area for the application of electrical biosensors over the last few decades. Extremely high sensitivity of field-effect transistor-based (FET) biosensors directed the interest of scientists mostly to early cancer detection applications. However, the potential of electrical biosensors should not be limited to cancer diagnosis. With immunotherapy on the way to become the fourth pillar of cancer treatment, there will be an increasing demand for immunoassay testing before, during, and after the conduction of therapeutic treatment. Our previous results have demonstrated the usefulness of FET-based biosensors in the research and development of a safer engineered chimeric antigen receptor (CAR) T-cells-based therapy. In this work, we continue to explore the practicality of electrical biosensors in the potential therapeutic setting of immunotherapy. Here, we present a complete stand-alone FET-based biosensing system relying on the extended gate (EG) concept. Our platform has an independent readout which is portable, compatible with multiplexed measurement, and self-sufficient for point-of-care sensing purposes. The extended gate sensing chip is disposable and can be tailored for the specific sensing application. Compared to the traditional ion-sensitive FET setup, EG FET provides improved flexibility, cost-effectiveness, and adaptiveness to individual needs making it a promising candidate for clinical application. During a universal CAR T-cells (UniCAR) therapy, “switch” molecules are injected into the patient’s bloodstream to activate the T-cell processes for attacking tumors. Therefore, it is crucial to monitor the level of CAR T-cells and switch molecules for better control and decision-making related to personalized treatment. Here, we demonstrate the application of our EG FET platform in testing the therapeutic components of this treatment and discuss the related outlook for FET-based biosensors in immunotherapy. Our work endeavors to bridge the gap between clinical needs in immunotherapy and available sensing technology by broadening the application area for electrical biosensors.

Microorganisms show a high affinity for trivalent actinides and lanthanides, which play an important role in the safe disposal of high-level radioactive waste as well as in the mining of various rare earth elements. The interaction of the lanthanide Eu(III) with the sulfate-reducing microorganism Desulfosporosinus hippei DSM 8344T, a representative of the genus Desulfosporosinus that naturally occurs in clay rock and bentonite, was in-vestigated. Eu(III) is often used as a non-radioactive analogue for the trivalent actinides Pu(III), Am(III), and Cm(III), which contribute to a major part of the radiotoxicity of the nuclear waste. D. hippei DSM 8344T showed a weak interaction with Eu(III), most likely due to a complexation with lactate in artificial Opalinus Clay pore water. Hence, a low removal of the lanthanide from the supernatant was observed. Scanning transmission electron microscopy coupled with energy-dispersive X-ray spectroscopy revealed a bioprecipitation of Eu(III) with phosphates potentially excreted from the cells. This demonstrates that the ongoing interaction mechanisms are more complex than a sim-ple biosorption process. The bioprecipitation was also verified by luminescence spec-troscopy, which showed that the formation of the Eu(III) phosphate compounds starts almost immediately after the addition of the cells. Moreover, chemical microscopy pro-vided information on the local distribution of the different Eu(III) species in the formed cell aggregates. These results provide first insights into the interaction mechanisms of Eu(III) with sulfate-reducing bacteria and contribute to a comprehensive safety concept for a high-level radioactive waste repository, as well as to a better understanding of the fate of heavy metals (especially rare earth elements) in the environment.

From microplastics resuspending into the atmosphere to earth particles left behind during extraterrestrial explorations, the resuspension of microparticles by a turbulent gas flow occurs in many natural and industrial systems. Wall surfaces, onto which particles initially adhere, are rarely smooth and this surface roughness affects their resuspension. Available experimental data on particle resuspension have been obtained with substrates, whose surfaces are either unaltered or manually abraded with, for instance, sand blasting. In these experiments, the roughness elements span a wide size range and are in-homogeneously distributed in space. Surface functionalization is a modern technique allowing the precise fabrication of a wall surface with well-characterized microstructures, hence reducing the asperity randomness associated with conventional abrasion techniques. Taking advantage of surface functionalization, we present here a new set of reference data, where the wall asperities are represented by a structured arrangement of micropillars and microcubes. Adhesion force measurements and particle remaining fraction against gas velocity, at Reynolds number up to 8000, are reported for one reference and two artificially roughened substrates. Laboratory measurements show that the microasperities have little to moderate effect on the mean adhesion force and the threshold velocity, at which half of the 100-µm particles resuspend. The standard deviations are, however, significantly affected. The presented results will primary contribute to the improvement of resuspension models, which until now rely on a simplified representation of the surface roughness elements. The presented measurements are highly compatible with such models, which involve elementary roughness features, such as hemispherical asperities superimposed with a flat plate.

We study the meson contribution to the equation of state of the 2-flavor Polyakov-loop Nambu–Jona-Lasinio model, including the full momentum dependence of the meson polarization loops. Within the Beth-Uhlenbeck approach, we demonstrate that the contribution from the quark-antiquark continuum excitations in the spacelike region ω^2 − q^2 < 0, i.e., the Landau damping, leads to an increase of the pressure for temperatures ≳0.8T^χ_c and a significant meson momentum cutoff dependence in the mesonic pressure and the QCD trace anomaly. We investigate the dependence of the results on the choice of the Polyakov-loop potential parameter T_0. From the dependence of the mesonic pressure on the current quark mass, by means of the Feynman-Hellmann theorem, we evaluate the contribution of the pion quasiparticle
gas and Landau damping to the chiral condensate.

We utilize pump-probe spectroscopy to measure the quasiparticle relaxation dynamics of BaFe2As2 in a diamond anvil cell at pressures up to 4.4 GPa and temperatures down to 8 K. Tracing the amplitude of the relaxation process results in an electronic phase diagram that illustrates the variation of the spin-density wave (SDW) order across the whole range of the applied pressures and temperatures. We observe a slowing down of the SDW relaxation dynamics in the vicinity of the phase transition boundary. However, its character depends on the trajectory in the phase diagram: the slowing down occurs gradually for the pressure-induced transition at low temperatures and abruptly for the thermally-driven transition. Our results suggest that the pressure-induced quantum phase transition in BaFe2As2 is related to the gradual worsening of the Fermi-surface nesting conditions.

To date, perfusion simulations in the human brain have been limited to a relatively small number of patient-specific cases. Here, a
pipeline relying on magnetic resonance imaging (MRI) is proposed to overcome this limitation. The computational geometry is
adjusted using T1-weighted MRI, whereas the perfusion model parameters are tuned based on arterial spin labeling perfusion MRI. A
cohort of 75 patients is considered to demonstrate that the pipeline is suitable to generate virtual patients with statistically realistic
cerebral blood flow maps. In the future, in silico clinical trials will be conducted using similar virtual cohorts to improve ischaemic
stroke interventions.

We demonstrate a significantly simplified experimental approach for investigating liquid metallic hydrogen, which is crucial to
understand the internal structure and evolution of giant planets. Plastic samples were shockcompressed and then probed by
short pulses of X-rays generated by free electron lasers. By comparison with ab initio simulations, we provide indirect
evidence for the creation of elemental hydrogen in shock-compressed plastics at ∼150GPa and ∼5,000K and thus in a
regime where hydrogen is predicted to be metallic. Being the most common form of condensed matter in our solar system,
and ostensibly the simplest of all elements, hydrogen is the model case for many theoretical studies and we provide a new
possibility to benchmark models for conditions with extreme pressures and temperatures. Moreover, this approach will also
allow to probe the chemical behavior of metallic hydrogen in mixture with other elements, which, besides its importance for
planetary physics, may open up promising pathways for the synthesis of new materials.

Actinides (An) play an important role in chemical research and environmental science related to the nuclear industry or nuclear waste repositories. Investigating their coordination chemistry can function as a tool to obtain fundamental understanding of actinide binding. Due to the radiotoxicity of actinide complexes, special care in handling those material is needed in form of working in a controlled area lab. Therefore, the understanding of complexation properties of the actinides, in particular the transuranium (TRU) elements, is lacking behind those of the d- or 4f-elements.
For the early actinides possible oxidation states typically range from +II to +VII. A suitable approach to explore fundamental physico-chemical properties of the actinides is to study series of isostructural An compounds in which the An is in the same oxidation state. Therefore, our investigations are directed towards the synthesis of actinide complexes (An = Th, U, Np, and Pu) with the f-element in the oxidation state IV, the dominant oxidation state particularly under anoxic conditions. Observed changes in e.g. the binding situation or magnetic effects along such series deliver insight into the elements’ unique electronic properties mainly originating from the f-electrons. One important question in the field of An chemistry is the degree of “covalency” in compounds across the An series, which may be addressed by systematic studies on series of An compounds, including transuranium (TRU) elements.
An complexes using ambidentate ligand systems can give valuable information on covalency differences between soft and hard donor atoms in one complex system. We therefore chose the 2-mercaptopyridyl ligand system (PyS) as monoanionic ambidentate S,N-moiety. Due to possible resonance structures in the ligand backbone, the negative charge can be distributed over both donor atoms. This leaves sufficient flexibility for PyS to coordinate to the actinide atom in a S- or N-monodentate or S,N-chelating manner. We synthesized a series of PyS-containing Th, U, Np, and Pu complexes and compare their structural and spectroscopic characteristics along the early actinides. These results are used as a basis to further analyze bonding trends along the actinide series by means of quantum chemical calculations.
From the results, trendlines along the actinides were obtained, which shed some light in the ongoing debate of covalency in actinide bonding.

https://u.ganil-spiral2.eu/10.26143/GANIL-2016-E710.html

Im Zusammenspiel magnetischer und elektrischer Felder entstehen
elektromagnetische Kräfte. Deren praktische Anwendung z. B. in Elektromotoren ist aus unserem Alltag nicht mehr wegzudenken.
Elektromagnetische Kräfte sind aber auch in der Lage, leitfähige Flüssigkeiten, wie Elektrolyte und Metallschmelzen, kontaktlos zu beeinflussen.
Die Vielfalt an Strömungskonfigurationen, die mit einfachen Permanentmagneten in einer Elektrolysezelle einstellbar sind, wird im Experiment
demonstriert.

Energie ist auf vielfltige Weise mit dem Leben verknüpft. Im Laufe der Geschichte dominierten unterschiedliche Energieträger. Der Vortrag nimmt sie unter die Lupe und zeigt den Wandel ihrer Nutzung und die damit verbundenen Konsequenzen. Ein Schwerpunkt ist die im Horizon 2020 Projekt SOLSTICE entwickelte Speichertechnologie.

Die geplante Umstellung des Energiesystems auf fluktuierende Erzeuger zieht einen immensen Bedarf an Speichern nach sich, um Angebot und Nachfrage auszugleichen. Der Vortrag stellt verschiedene Arten von Flüssigmetallbatterien vor, die derzeit mit dem Ziel einer ökonomischen stationären Energiespeicherung entwickelt werden.

Die geplante Umstellung des Energiesystems auf fluktuierende Erzeuger zieht einen immensen Bedarf an Speichern nach sich, um Angebot und Nachfrage auszugleichen. Der Vortrag stellt verschiedene Arten von Flüssigmetallbatterien vor, die derzeit mit dem Ziel einer ökonomischen stationären Energiespeicherung entwickelt werden.

Classical novae are thermonuclear explosions in stellar binary sys- tems, and important sources of 26Al and 22Na. While γ rays from the decay of the former radioisotope have been observed throughout the Galaxy, 22Na remains untraceable. Its half-life (2.6 yr) would allow the observation of its 1.275 MeV γ-ray line from a cosmic source. However, the prediction of such an observation requires good knowl- edge of its nucleosynthesis. The 22Na(p,γ)23Mg reaction remains the only source of large uncertainty about the amount of 22Na ejected. Its rate is dominated by a single resonance on the short-lived state at 7785.0(7) keV in 23Mg. Here, a combined analysis of particle-particle correlations and velocity-difference profiles is proposed to measure femtosecond nuclear lifetimes. The application of this method to the study of the 23Mg states, places strong limits on the amount of 22Na produced in novae and constrains its detectability with future space-borne observatories.

Radionuclide therapies are an important tool for the management of patients with neuroendocrine tumors (NETs). Especially [131I]MIBG and [177Lu]Lu-DOTA-TATE are routinely used for the treatment of a subset of NETs, including phechromocytomas, paragangliomas and gastroenteropancreatic tumors. Some patients suffering from other forms of NETs, such as medullary thyroid carcinoma or neuroblastoma, were shown to respond to radionuclide therapy; however, no general recommendations exist. Although [131I]MIBG and [177Lu]Lu-DOTA-TATE can delay disease progression and improve quality of life, complete remissions are achieved rarely. Hence, better individually tailored combination regimes are required. This review summarizes currently applied radionuclide therapies in the context of NETs and informs about recent advances in the development of theranostic agents that might enable targeting subgroups of NETs that previously did not respond to [131I]MIBG or [177Lu]Lu-DOTA-TATE. Moreover, molecular pathways involved in NET tumorigenesis and progression that mediate features of radioresistance and are particularly related to the stemness of cancer cells are discussed. Pharmacological inhibition of such pathways might result in radiosensitization or general complementary antitumor effects in patients with certain genetic, transcriptomic, or metabolic characteristics. Finally, we provide an overview of approved targeted agents that might be beneficial in combination with radionuclide therapies in the context of a personalized molecular profiling approach.

In our HELIPORT workshop, we provided insights into our project and share our results. In addition, we would like to provide a platform for the presentation of similar projects, as well as extensions or integrations from the surrounding research areas. The overall goal of the workshop is bringing together different institutions with similar challenges and establishing a community around our HELIPORT project.
We therefore encouraged our community to submit an abstract for a talk or poster. The submissions are dedicated to four thematic points:

• HELIPORTuse-cases,
• Scientificprojectandmetadatamanagement, • Experiment-specificandoverallmetadataand • Scientificworkflows.

Warm dense matter (WDM)---an extreme state that is characterized by extreme densities and temperatures---has emerged as one of the most active frontiers in plasma physics and material science. In nature, WDM occurs in astrophysical objects such as giant planet interiors and brown dwarfs. In addition, WDM is highly important for cutting-edge technological applications such as inertial confinement fusion and the discovery of novel materials. In the laboratory, WDM is studied experimentally in large facilities around the globe, and new techniques have facilitated unprecedented insights. Yet, the interpretation of these experiments requires a reliable diagnostics based on accurate theoretical modeling, which is a notoriously difficult task [1]. In this work, I will give an overview of how we can use exact ab-initio path integral Monte Carlo (PIMC) simulations [2] together with thermal density functional theory (DFT) calculations to get new insights into the behavior of WDM. Moreover, I will show how switching to the imaginary time representation allows us to significantly improve the interpretation of X-ray Thomson scattering (XRTS) experiments, which are a key diagnostic for WDM [3]. Specifically, I will present a model-free temperature diagnostic [4] based on the well-known principle of detailed balance, but available for all wave numbers, and a new idea to directly extract the electron— electron static structure factor from an XRTS measurement [5]. As an outlook, I will show how new PIMC capabilities will allow to give us novel insights into electronic correlations in warm dense quantum plasmas, leading to unprecedented agreement between experiments [6] and theory.

[1] M. Bonitz et al., Physics of Plasmas 27, 042710 (2020)

[2] M. Böhme et al., Physical Review Letters 129, 066402 (2022)

[3] S. Glenzer and R. Redmer, Reviews of Modern Physics 81, 1625 (2009)

[4] T. Dornheim et al., Nature Communications 13, 7911 (2022)

[5] T. Dornheim et al., arXiv:2305.15305 (submitted)

[6] T. Döppner et al., Nature 618, 270-275 (2023)

In this talk, I will present our research on the application of time-dependent density functional theory (TDDFT) to model observables induced in matter under extreme conditions. Specifically, I will discuss the electron loss function in scattering experiments with X-ray free electron lasers [1] and the electrical conductivity in metals [2, 3]. Additionally, I will explore the potential of physics-informed neural networks for solving the time-dependent Kohn-Sham equations, which describe electron dynamics in response to incident electromagnetic waves [4].

[1] Z. Moldabekov, T. Dornheim, A. Cangi, Sci. Rep. 12, 1093 (2022).
[2] K. Ramakrishna, M. Lokamani, A. Baczewski, J. Vorberger, A. Cangi, Phys. Rev. B 107, 115131 (2023).
[3] K. Ramakrishna, M. Lokamani, A. Baczewski, J. Vorberger, A. Cangi, arXiv:2210.10132 (2022).
[4] K. Shah, P. Stiller, N. Hoffmann, A. Cangi, NeurIPS Machine Learning and the Physical Sciences, arXiv:2210.12522 (2022).

In this talk, I will present two lines of our research. In the first part, I will discuss the application of time-dependent density functional theory (TDDFT) in modeling observables induced in matter under extreme conditions, such as the electron loss function relevant to scattering experiments with X-ray free electron lasers [1] and the electrical conductivity in metals [2]. In the second part, I will highlight our recent progress in leveraging Artificial Intelligence (AI) to enhance the efficiency of electronic structure calculations [3]. Specifically, I will focus on our efforts to accelerate Kohn-Sham density functional theory calculations at finite temperatures by integrating deep neural networks into the Materials Learning Algorithms framework [4,5]. Our results demonstrate significant improvements in calculation speed for metals up to their melting point. Additionally, our implementation of automated machine learning has led to substantial savings in computational resources for identifying optimal neural network architectures, paving the way for large-scale AI-driven investigations [6]. Lastly, I will present our latest breakthrough, showcasing the capability of neural-network-driven electronic structure calculations for systems containing over 100,000 atoms [7].

[1] Z. Moldabekov, T. Dornheim, A. Cangi, Sci. Rep. 12, 1093 (2022).
[2] K. Ramakrishna, M. Lokamani, A. Baczewski, J. Vorberger, A. Cangi, Phys. Rev. B 107, 115131 (2023).
[3] L. Fiedler, K. Shah, M. Bussmann, A. Cangi, Phys. Rev. Materials 6, 040301, (2022).
[4] A. Cangi, J. A. Ellis, L. Fiedler, D. Kotik, N. A. Modine, V. Oles, G. A. Popoola, S. Rajamanickam, S. Schmerler, J. A. Stephens, A. P. Thompson, MALA, https://doi.org/10.5281/zenodo.5557254 (2021).
[5] J. A. Ellis, L. Fiedler, G. A. Popoola, N. A. Modine, J. A. Stephens, A. P. Thompson, A. Cangi, Phys. Rev. B 104, 035120 (2021).
[6] L. Fiedler, N. Hoffmann, P. Mohammed, G. A. Popoola, T. Yovell, V. Oles, J. A. Ellis, S. Rajamanickam, A. Cangi, Mach. Learn.: Sci. Technol. 3, 045008 (2022).
[7] L. Fiedler, N. A. Modine, S. Schmerler, D. J. Vogel, G. A. Popoola, A. P. Thompson, S. Rajamanickam, A. Cangi, Npj Comput. Mater., accepted (2023).

This paper defines a 3D full core neutronics benchmark which is based on the NuScale small modular reactor (SMR) concept. The paper provides a detailed description of the NuScale-like core, a list of expected outputs, and a reference solution to the benchmark exercises obtained with the Monte Carlo code Serpent.

The benchmark was developed in the framework of the Euratom McSAFER project and can be used for verification of computational chains dedicated to 3D full-core neutronics simulations of water cooled SMRs.

The paper is supplemented with a digital data set to ease the modeling process.

BaFe2As2 is the parent compound for a family of iron-based high-temperature superconductors as well as a prototypical example of the spin-density wave (SDW) system. In this study, we perform an optical pump-probe study of this compound to systematically investigate the SDW order across the pressure-temperature phase diagram. The suppression of the SDW order by pressure manifests itself by the increase of relaxation time together with the decrease of the pump-probe signal and the pump energy necessary for complete vaporization of the SDW condensate. We have found that the pressure-driven suppression of the SDW order at low temperature occurs gradually in contrast to the thermally-induced SDW transition. Our results suggest that the pressure-driven quantum phase transition in BaFe2As2 (and probably other iron pnictides) is continuous and it is caused by the gradual worsening of the Fermi-surface nesting conditions.

In laser wakefield acceleration, a laser pulse interacts with plasma to accelerate electrons.
These novel small-scale accelerators require an ultra-short, high-intensity laser system. The
intensity and its temporal distribution can be described by the spectrum of the laser. Initially,
this spectrum has the characteristics of a time-varying Gaussian-like shape with several smaller
peaks and fluctuations. Before the laser can be used in experiments, it must be amplified to
the desired intensities. If the initial spectrum is amplified, the uneven intensity distribution of
the Gaussian-like shape can lead to high intensities at the wavelengths at the corresponding
peak positions. These high intensities form a potential threat due to the amount of energy
present over a short period, which could lead to the loss and destruction of laboratory equip-
ment. Consequently, the spectrum must be equalized in gain. To achieve gain equalization,
the shape of the spectrum must be changed accordingly, subject to the time-varying unmodi-
fied initial spectrum.
One option for performing the spectral shaping is the ”Mazzler” device developed and con-
structed by the French companies, Fastlite and Amplitude technologies. This device can modify
an optical input beam in a flexible manner and be adjusted to complex settings. However, this
is currently performed by an proprietary feedback loop shipped with the device. Consequently,
the details and inner workings of this software are inaccessible. The feedback loop has only a
single mode of operation, which is the purposing of a single predefined spectral target. This
target is the equalization of the spectral gain, in which the intensities of the spectrum are
more evenly distributed, thereby allowing for better amplification. While this modification of
the spectrum is achieved by the feedback loop to a reliable and sufficient degree, multiple iter-
ations of the underlying algorithm are needed to reach the desired state. Since the execution
of each of these steps requires manual interaction, the question of a faster solution arises.
Approaching this task in a data-driven manner is a promising direction for achieving this, since
the corresponding methods allow utilization of already existing experience in the form of data,
gained by modifying spectra in the past. Unlike the current feedback loop, this would imply that
prior executions in previous optimization procedures were not forgotten, but used to build a
model capable of reaching the desired goal more quickly. Furthermore, a method capable of
this could potentially also be used to perform other modifications to the spectra, demonstrat-
ing promising features important for specific use cases such as laser wakefield acceleration.
The generation and optimization of settings for the Mazzler device with neural networks is
the major task introduced in this thesis. An actor-critic model with multiple adaptations of the
algorithm and the underlying models is presented and proposed as an novel approach to this
problem. These models are capable of optimizing in a large, continuous domain through the
exploration-based generation of data, enabling to reach states not present in any available
data. This makes them especially suitable for the optimization of Mazzler settings to modify
spectra in an unprecedented manner. Furthermore, extensive data-related processing to re-
strict the state and action-space of the method are investigated to enable stable operation
and improved efficiency of the hardware in the laboratory. Corresponding results gathered
over multiple days in the DRACO laser laboratory of HZDR are presented with the proposed
method controlling the Mazzler device. Additionally, since execution of these experiments re-
quires hardware interaction, an implementation of this functionality is presented.

In the present work, the two-fluid model (TFM) is coupled with the population balance model (PBM) to trace the spatial and temporal change of bubble size and interfacial area concentration (IAC) in flashing flows. The model is first validated for bubble growing in stagnant superheated liquid, and satisfactory predictions of the bubble size under low and moderate superheat are obtained. It is then applied to flashing pipe flows, which are characterized by low superheat and high turbulence intensities. The results show that in these cases, coalescence and breakup are important phenomena changing the bubble size distribution in addition to growth. The neglect of their contribution leads to a significant under-prediction of the bubble size and consequently over-prediction of IAC. In addition, choosing an appropriate closure for interfacial heat transfer coefficient (HTC) is another key point in flashing simulation. In high-Reynolds cases (e.g. Re > 10^6), the enhancement due to turbulence is nonnegligible.

n this paper, we present an experimental investigation that centers on exploring the fluid dynamics within a
precessing cylinder. Our research is part of the DRESDYN project at Helmholtz-Zentrum Dresden-Rossendorf,
specifically focusing on the precession dynamo experiment. The primary objective of our study is to examine how
different rotation configurations influence the dominant flow modes inside the precessing cylinder, specifically
considering the prograde and retrograde rotations. Our main focus lies on two significant flow modes: the directly
forced mode (m1, k1) and the non-geostrophic axisymmetric mode (m0, k2). These modes hold substantial potential
for precession-driven dynamo action. By analyzing the outcomes between the prograde and retrograde
configurations, we gain valuable insights into the prevailing flow patterns within the precessing cylinder.

In the ternary system CsCl – NaCl – H₂O, at a temperature of 298.15 K, a double salt with the stoichiometric formula CsCl∙2NaCl∙2H₂O(cr) is known to be formed. This double salt and the anhydrous CsCl(cr) are the end-members of a solid solution. For the pure double salt, the solubility constant was determined. The obtained value were applied to calculate the solubility diagram also of the quaternary system CsCl – NaCl – KCl – H₂O and the quaternary-reciprocal system Cs⁺, Na⁺ || Cl⁻, SO₄²⁻ – H₂O. The solubility constant together with a solid solution between CsCl∙2NaCl∙2H₂O(cr) and CsCl(cr) were implemented in THEREDA, which extends the applicability of the existing cesium dataset.

This presentation will provide an overview of the coherent THz sources and the user activities at the ELBE Radiation Source. Ideas for new types of measurements and materials to study will be discussed, followed by a look toward DALI, the concept for a new facility at HZDR for advanced accelerator-based THz sources.

Lignin hydrogenolysis into monophenols presents a promising route for lignin-based chemical and fuel production but still suffers from harsh reaction conditions (e.g. high temperature and high external H2 pressure). Herein, we report an ultrafine Ni nanocluster anchored on N-doped carbon nanosheets (Ni/LNC) for efficient catalytic transfer hydrogenolysis of poplar organosolv lignin. The catalyst was fabricated through a simple pyrolysis process of lignin‑nickel complex mixed with melamine, in which the lignin coordination greatly improved the Ni dispersion and the strong Nisingle bondN interaction inhibited the Ni nanocluster growth, resulting in the ultrafine particle size (1–2 nm). Under mild conditions (160 °C, 1 h), 22.08% of monophenol yield was obtained over the catalyst, which was significantly higher than those over the two reference catalysts (Ni/AC and Ni/LC) as well as other previously reported Ni-based catalysts. The excellent catalytic activity can be attributed to both the substantial increase in catalytic active sites and the enhancement in H transfer from methanol resulted from the electron-rich N-doped nanosheet support. Finally, magnetically recycled Ni/LNC showed excellent recycling stability. Consequently, this work presents a facile and low-cost approach for the synthesis of N-doped carbon nanosheet supported ultrafine Ni nanocluster and further demonstrates its superior applicability in lignin hydrogenolysis.

In response to China's commitment to meet carbon peaking and carbon neutrality targets, universities are seeking to assess and minimize their greenhouse gas emissions. In this study, a new methodology based on LEAP and LCA was developed to assess the carbon footprint of a medium-sized university campus in eastern China. The emission sources consider six areas: electricity, fuel, transportation, water, waste, and consumption of other materials. The results showed that the campus emitted about 13,877 tonnes of CO2-eq in 2020. In particular, electricity consumption contributed about 77% of the total CO2-eq emissions on campus, while green cover and material recycling resulted in a negative emission of 404.4 tonnes of CO2-eq. In addition, seven common mitigation strategies were proposed to reduce the campus carbon footprint, and budgets would influence the implementation time. It was found that the seven proposed carbon reduction measures could reduce emissions by 97% in 2060, with decarbonisation of electricity being the largest contributor, leading to an emissions reduction of 64.7%. In addition, carbon offsetting is needed to achieve a carbon-neutral campus by 2060.

Air Taylor bubbles in a millichannel filled with water are characterized by an elongated shape, a bullet-shaped nose and a comparatively flat tail. Many experimental and numerical investigations have been performed in the past. Yet, most of them consider Taylor bubbles in a straight channel with constant cross-section. The effect of a local change in the channel geometry on both the bubble shape and the flow fields on each side of the gas-liquid interface is, however, difficult to predict. In this work, we present experimental data obtained in a vertical millichannel, where the flow is moderately obstructed by a constriction, whose ratio ranges from 10 to 36 %. \rhandrey{We find that the Taylor bubble takes an equilibrium position for downward liquid flow with 264.36 < Re < 529.67 and 264.36 < Re < 728.29 for 10.17 % and 18.06 % constriction ratios, respectively}. In this area, an empirical correlation characterizing the bubble head is provided. Other flow regimes, such as bubble breakup, co- and counter-current configurations are identified and shown in the form of a regime map. The results, besides their relevance in process engineering, exhibit high reproducibility and will serve as reference for future interface resolving two-phase flow simulations.

A dataset is considered complete if, in addition to the pure data (e.g. measured values), further information, such as origin and license for use, is also available. This requires not only the complete collection of data and metadata, but also assistance or instructions for collection and use, as well as an infrastructure for storage, publication and unique identification. Such a "value chain" is made up of various processes that should be handled by people in defined roles.

In this context, it is also necessary to provide a technical infrastructure which, on the one hand, generates a precise input mask for the user's specific case, but which, on the other hand, must direct general search queries in a targeted manner to the correct data records. And of course, this entire construct cannot be controlled without rules and documentation, and must be equipped with an adapted training offering and an intuitive user interface. The training offer is also aimed at people with roles or assigned tasks in the data management system to ensure that the roles are performed with the necessary quality by defining the necessary qualifications. A plausibility check, which takes into account the expected flexibility of the system, guarantees the consistency of the data records. In one of the highest levels of sophistication, the plausibility check is followed by a kind of self-healing mechanism that suggests a data set to the user according to the specifications or makes the user's re-intervention obsolete altogether.

In this contribution, the focus will be on the roles and on the interaction with the data management system. All necessary qualifications and tasks are assigned to the roles. The advantage of the subdivision into roles is that it remains open whether the additional tasks are covered by existing or new personnel or whether one person holds several roles. This means that the specific personnel approach can be adapted to the institution's own needs.

Multiple dopant configurations of Te impurities in close vicinity in silicon are investigated using photoelec- tron spectroscopy, photoelectron diffraction, and Bloch wave calculations. The samples are prepared by ion implantation followed by pulsed laser annealing. The dopant concentration is variable and high above the solubility limit of Te in silicon. The configurations in question are distinguished from isolated Te impurities by a strong chemical core level shift. While Te clusters are found to form only in very small concentrations, multi-Te configurations of type dimer or up to four Te ions surrounding a vacancy are clearly identified. For these configurations a substitutional site location of Te is found to match the data best in all cases. For isolated Te ions this matches the expectations. For multi-Te configurations the results contribute to understanding the exceptional activation of free charge carriers in hyperdoping of chalcogens in silicon.

Contactless Inductive Flow Tomography (CIFT) is a flow measurement technique allowing for visualizing the global flow in electrically conducting fluids. The method is based on the precise measurement of very weak induced magnetic fields arising from the fluid motion under the influence of one or several primary excitation magnetic field(s). The simultaneous use of more than one excitation magnetic field is necessary to fully reconstruct three-dimensional liquid metal flows, yet is not trivial as the scalar values of induced magnetic field at the sensors need to be disentangled for each contribution of the excitation fields. Another approach is to multiplex the excitation fields. Here the temporal resolution of the measurement needs to be kept as high as possible. We apply two trapezoidal-shaped excitation magnetic fields with perpendicular direction to each other to a mechanically driven liquid metal flow. The consecutive application by multiplexing enables to determine the flow structure in the liquid with a temporal resolution down to 3 s with the existing equipment.

Alkaline water electrolysis is a mature and cost-effective technology for hydrogen production. By using wind or solar derived energy, the hydrogen produced is a promising approach to replace fossil fuels and establish a net-zero-emission-industry [1]. However, by blocking electrocatalytic sites the generated bubbles cause significant losses in terms of increased overpotential and ohmic resistance losses [2,3]. Therefore, the study of bubble dynamics on porous electrodes commonly used in industrial electrolyzers is essential to improve the overall efficiency of alkaline electrolysis.

In the present study, a novel three electrode cell is introduced to perform parametric studies of H2 evolution on porous electrodes [4]. For this purpose, electrochemical methods are combined with high-speed optical measurements to characterize the electrodes in terms of electrochemical active surface areas (ECSA), bubble size distribution and electrode coverage. The performance of the electrode can then be derived as a function of current density and applied electrolyte flow rate.

References
[1] L. Lüke and A. Zschocke, Alkaline Water Electrolysis: Efficient Bridge to CO2 -Emission-Free Economy, Chem. Ing. Tech., 92 (2020) 70–73.
[2] A. Angulo et al., Influence of Bubbles on the Energy Conversion Efficiency of Electrochemical Reactors, Joule 4 (2020) 555-579.
[3] J.R. Lake et al., Impact of Bubbles on Electrochemically Active Surface Area of Microtextured Gas-Evolving Electrodes, Langmuir 38 (2022) 3276-3283.
[4] H. Rox et al., Bubble size distribution and electrode coverage at porous nickel electrodes in a novel 3-electrode flow-through cell, Int. J. Hydrog. Energy 48 (2023) 2892-2905.

Flashing-induced instability (FII) has a significant impact on the safe operation of a natural cir-culation circuit, a phenomenon frequently encountered in the cooling systems of advanced light water reactors. While one-dimensional system codes are commonly used for engineering design and safety analysis of FII, there is a strong academic interest in understanding the underlying physical mechanisms. To address this, high-resolution computational fluid dynamics (CFD) simulations serve as a valuable tool. However, the current state of CFD modeling for phase change two-phase flows, particularly high transient fluctuating flashing flows, is still in its early stages of development. In this study, we establish a CFD model that focuses on interphase heat transfer to analyze FII. By incorporating experimental data from the literature, we investigate the transient flow field and thermodynamic behavior in the riser of the GENEVA test facility. The study provides valuable insights into the non-equilibrium and interfacial transfer phenom-ena during the phase change as well as the effect of high-frequency fluctuation. Additionally, we discuss in detail the challenges associated with FII modeling and the limitations of the current model. We also provide suggestions for potential improvements in future numerical studies.

Characterizing the physicochemistry and microbial diversity of U mine water is a key prerequisite for understanding the biogeochemical processes occurring in these water mass and for the design of an efficient bioremediation strategy. This study has collected and analysed in reference date measurements water samples from two former U-mines (Schlema-Alberoda and Pöhla, Wismut GmbH) in East Germany. The samples from both mines are pH-circumneutral (7.3 and 6.6) and show reducing conditions (E_H: +139 and –91 mV). Interestingly, the U and sulphate concentrations of Schlema-Alberoda mine water (U: 1 mg/L; SO₄ ²⁻: 335 mg/L) are 2 and 3 order of magnitude higher than those of the Pöhla samples (U: 0.01 mg/L; SO₄ ²⁻: 0.5 mg/L), respectively. U, SO₄ ²⁻ and Fe seem to shape the differential microbial diversity of the water from both mines. Microbial diversity analysis revealed the distribution of bacteria with U(VI)-reducing capacity and the ability to maintain the stability of reduced U-species (e.g., Desulfurivibrio, Gallionella and Sulfuricurvum). In addition, water from the mines harbour wood-degrading fungal communities (e.g., composed of Cadophora and Acremonium) providing potential electron donors which promote the growth of U-reducing bacteria. For the design of a bioremediation strategy, we conducted a preliminary U-bioreduction experiment to screen for suitable electron donors (glycerol, vanillic acid and gluconic acid). We also observed that high levels of soluble U (initially present as Ca₂UO₂(CO₃)₃(aq) and UO₂(CO_{3) 3} ⁴⁻), Fe and SO₄ ²⁻ were removed by 98, 95 and 53%, respectively from the mine water by using glycerol as electron donor. The remaining U concentrations after bioreduction meet regulatory standards for beneficial reuse of U mine water. As a whole, the results reveal the chemical factors influencing the microbial community in U mine water and may contribute to the design of bioremediation strategies based on the biostimulation of U-reducing bacteria for low U concentrations in contaminated water.

Electrochemical upgrading of ethanol to acetic acid provides a promising strategy to couple with the current hydrogen production from water electrolysis. This work reports the design of a series of bimetallic Pt-Hg aerogels, where the PtHg aerogel exhibits a 10.5-times higher mass activity than that of commercial Pt/C toward ethanol oxidation. More impressively, the PtHg aerogel demonstrates nearly 100% selectivity toward the production of acetic acid. The operando infrared spectroscopic studies and nuclear magnetic resonance analysis verify the preferable C2 pathway mechanism during the reaction. This work opens an avenue for the electrochemical synthesis of acetic acid via ethanol electrolysis.

Interactions of selenium (Se), a trace element bio-essential at low concentrations but highly toxic at high concentrations, with the most abundant mineral in the Earth's crust, namely pyrite, was investigated over a wide range of time scales. At the nanosecond scale, selenate Se(VI)O42– adsorption onto the net pyrite surface is shown by ab-initio computations to proceed via the formation of a chemical bond between an oxyanion oxygen atom and a surface Fe atom, weakening the other Se-O bonds and reducing Se atom oxidation state. At the hour-to-day scale, adsorption and coprecipitation of selenate and selenite, Se(IV)O32–, were investigated through wet chemical batch experiments at various pH values at different sulfide concentrations. Selenium removal from solution is slower and weaker for selenate than for selenite. After 24h, only 10% of selenate, against 60% for selenite (or even 100% in the presence of sulfide), is removed by the pyrite surface. Independently of its original oxidation state, adsorbed Se is completely reduced to elemental selenium via adsorption or coprecipitation, as shown by XANES spectroscopy. Our EXAFS results, compared to published data on Se-rich pyrite, show a Se to S substitution within the pyrite structure. The reductive coprecipitation mechanism of selenium with pyrite represents valuable new insights for improving our understanding of modern and ancient biogeochemical cycles involving Se. In addition, several industries can benefit from direct applications of our findings, such as water treatment, green technologies and sustainable mining.

The old question of whether the solar dynamo is synchronized by the tidal forces of the orbiting planets has recently received renewed interest, both from the viewpoint of historical data analysis and in terms of theoretical and numerical modeling. We aim to contribute to the solution of this longstanding puzzle by analyzing cosmogenic radionuclide data from the last millennium. We reconsider a recent time-series of ¹⁴C-inferred sunspot data and compare the resulting cycle minima and maxima with the corresponding conventional series down to 1610 A.D., enhanced by Schove's data before that time. We fnd that, despite recent claims to the contrary, the ¹⁴C-inferred sunspot data are well compatible with a synchronized solar dynamo, exhibiting a relatively phase stable period of 11.07 years, which points to a synchronizing role of the spring tides of the Venus-Earth-Jupiter system.

We consider a conventional α–Ω-dynamo model with meridional circulation that exhibits typical features of the solar dynamo, including a Hale-cycle period of around 20 years and a reasonable shape of the butterfly diagram. With regard to recent ideas of a tidal synchronization of the solar cycle, we complement this model by an additional time-periodic α-term that is localized in the tachocline region. It is shown that amplitudes of some decimeters per second are sufficient for this α-term to become capable of entraining the underlying dynamo. We argue that such amplitudes of α may indeed be realistic, since velocities in the range of m/s are reachable, e.g. for tidally excited magneto–Rossby waves.

We introduce machine learning (ML) models that predict the electronic structure of materials across a wide temperature range. Our models employ neural networks and are trained on density functional theory (DFT) data. Unlike other ML models that use DFT data, our models directly predict the local density of states (LDOS) of the electronic structure. This provides several advantages, including access to multiple observables such as the electronic density and electronic total free energy. Moreover, our models account for both the electronic and ionic temperatures independently, making them ideal for applications like laser-heating of matter. We validate the efficacy of our LDOS-based models on a metallic test system. They accurately capture energetic effects induced by variations in ionic and electronic temperatures over a broad temperature range, even when trained on a subset of these temperatures. These findings open up exciting opportunities for investigating the electronic structure of materials under both ambient and extreme conditions.

In this talk, different approaches to keeping the HELIPORT code base maintainable will be presented. The talk will discuss both the tools used to automate various aspects of development and operation of HELIPORT, as well as how certain aspects of development are approached and how the choice of libraries and tooling helps these aspects.

Running a C.W. electron accelerator as a user facility for more than two decades necessitates upgrades or even complete redesign of subsystems at some point. At ELBE, the outdated timing system needed a replacement due to obsolete components and functional limitations. Starting in 2019, with Cosylab as contractor and using hardware by Micro Research Finland, the new timing system has been developed and tested and is about to become operational. Besides the ability to generate a broader variety of beam patterns from single pulse mode to 26 MHz C.W. beams for the two electron sources, one of the benefits of the new system is improved machine safety. The ELBE control systems is mainly based on PLCs and industrial SCADA tools. This contribution depicts how the timing system implementation to the existing machine entailed extensions and modifications of the ELBE machine protection system, i.e. a new core MPS PLC, and how they are being realized.

Für den Betrieb des Elektronen-Linearbeschleunigers am ELBE - Zentrum für Hochleistungsstrahlenquellen arbeiten wir im Bereich SCADA-System seit 2019 mit Kontron AIS GmbH im Rahmen eines Dienstleistungsvertrags zusammen. Wir stellen in der Präsentation den Beschleuniger vor, beschreiben die einzelnen Support- und Projektthemen und die damit verbundenen Vorteile für Betriebssicherheit und Nutzerfreundlichkeit und Wieterentwicklung unseres WinCC Leitsystems.

In recent years, more and more research was conducted to explore smaller and smaller systems that become similar to an
actual micro/nano-robot. The major roadblock regarding their real world implementation is the highly restricted available
volume. In this paper, we introduce folding – hence an origami technology using Al2O3 as building material, which is
compatible with current Si technology. High quality 50 nm thin Al2O3 film is grown by atomic layer desposition, patterned,
thinned and then released from the Si subtrate using SF6 plasma etching. The realized free standing Al2O3 structure would
fold itself at predefined regions due to the stress in the as deposited films. We believe such technology could offer a new
possibility to tackle the problem of efficiently using the volume. Al2O3 could act as both the structural origami material and
the functional gate dielectric material for electronics. This approach enables the feasibility of patterning devices and circuits
on every Al2O3 facet of a 3D object, while the inside volume of this object is still available for 3D bulk device components.
We demonstrate the optimized etching process as well as an emperical improvement of the folding hinges and of the overall
structural stability.

Data processing or analysis workflows are generally understood as processes running without any user intervention where usually only a small set of parameters being provided upon workflow submission, adjustment of which is also limited by low turnaround rates of workflow runs due to scheduling alone. Many types of experimental data analyses require manual experimentation with parameters to succeed, necessitating interactivity and fast iteration. In this talk we present examples of interactive workflow applications at HZDR, from data analysis and simulation; discuss challenges arising from differences to completely automated workflows and lay-out the related data-provenance and project-resource management features we envision for the HELIPORT workflow platform.

Compartmentalisation in a cell occurs by lipid membrane bound organelles or membrane-less organelles (MLOs). MLOs are dynamic liquid-like condensates inside the cell constituted of various biomolecules formed by liquid-liquid phase separation (LLPS). In LLPS, a biomolecule in an aqueous solution de-mixes from a single well-mixed phase to form two phases – a concentrated phase and a dilute phase. It creates a local concentration hotspot for the biomolecule, leading to enhancement of associated biological functions.
Creating two phases from a single well-mixed aqueous phase involves significant restructuring of the hydration water around the biomolecule. These dynamics are expected to play a crucial role in forming two coexisting phases in the same medium. However, the solvent's role in forming biomolecular condensates remains a relatively unexplored territory.
Recent pioneering work from our group has uncovered the critical role of solvent in the phase separation of RNA binding proteins (RBPs) and how differences in local hydration behaviour leads to phase separation. Following up on our previous work, we study how the alteration of hydration dynamics of different RBPs leads to their phase separation and how protein level modifications in the RBP modulate these dynamics.

The operation of nuclear power plants requires a supply of nuclear fuel where uranium plays a substantial role as a primary fissile material. Its extraction from U-bearing minerals and handling may cause a leakage of heavily toxic radioactive pollution, which ends up in water bodies and soil. Therefore, tackling U-contaminated water is crucial to preserve water integrity and quality. Zeolites are known as profound ion exchangers with great affinity towards cationic species present in polluted waters. Various zeolite synthesis routes have made this group of aluminosilicates even more promising to be applied as water purification materials. Here, the synthetic gismondite, faujasite, and Linde type-A zeolites from coal fly-ash were synthesized via tailored, coupled fusion-hydrothermal method and applied to remove aqueous uranium (primarily as 238U) under varying pH, time (sorption kinetics), and initial U concentrations (sorption isotherms). The maximum U uptake was observed for Na–P1 (GIS) zeolite, which equals 48.72 mg U/g, the highest reported value on maximum U adsorption capacity for zeolitic materials. The U adsorption kinetics showed that equilibrium is reached after approximately 3 h of adsorption and that the removal process follows a Freundlich isothermal model for all zeolites, thus preferential adsorption onto heterogeneous surfaces. Advanced spectroscopic studies, including laboratory-scale X-ray Photoelectron Spectroscopy with synchrotron light X-ray Absorption Near Edge Structure in High Energy Resolution Fluorescence Detection mode, revealed that at acidic pH, predominantly an ion exchange between Na+ ions with hexavalent uranyl species takes place. In contrast, in the neutral pH region, the U is immobilized via precipitation in the form of μm-scale mineral aggregates of Na-schoepite: Na(UO2)4O2(OH)55↓. The outcomes of the research study has demonstrated that synthetic zeolites, obtained from industrial by-products such as coal fly-ash, can be successfully valorized to efficient U adsorbents while unveiling the insights to understand the zeolites/U interactions at the nanoscale level.

Molybdenum sulfide (MoS₂) has attracted significant attention due to its great potential as a low-cost and efficient catalyst for the hydrogen evolution reaction. Developing a facile, easily upscalable, and inexpensive approach to produce catalytically active nanostructured MoS₂ with a high yield would significantly advance its practical application. Colloidal synthesis offers several advantages over other preparation techniques to overcome the low reaction yield of exfoliation and drawbacks of expensive equipment and processes used in chemical vapor deposition. In this work, we report an efficient synthesis of alloyed Re_xMo_1−xS₂ nanoflakes with an enlarged interlayer distance, among which the composition Re_0.55Mo_0.45S₂ exhibits excellent catalytic performance with overpotentials as low as 79 mV at 10 mA/cm² and a small Tafel slope of 42 mV/dec. Density functional theory calculations prove that enlarging the distance between layers in the Re_xMo_1−xS₂ alloy can greatly improve its catalytic performance due to a significantly reduced free energy of hydrogen adsorption. The developed approach paves the way to design advanced transition metal dichalcogenide-based catalysts for hydrogen evolution and to promote their large-scale practical application.

We report on the development of a pump system for ultrafast optical parametric amplifiers (uOPA) as an upgrade for the existing uOPA at the Petawatt High Energy Laser for heavy Ion eXperiments (PHELIX) and the new Petawatt ENergy-Efficient Laser for Optical Plasma Experiments (PEnELOPE). The system consists of a two-stage chirped pulse amplifier, centered around a high energy Yb:YAG regenerative amplifier that delivers 108 mJ uncompressed output energy, resulting in 92 mJ at 1030 nm after compression, pulse durations of 1.4 ps, a high beam quality of Mx/y2 = 1.02 / 1.16 and a relative energy stability of 0.35 %. A second harmonic generation (SHG) efficiency of up to 70 % is achievable and a maximum pulse energy of 43 mJ at 515 nm has been obtained, which is only limited by the damage threshold of the SHG crystal. A self-phase modulation stage makes this system a widely applicable, self-seedable pump module for uOPA without placing strong requirements on its seed oscillator.

The properties of hydrogen at warm dense matter (WDM) conditions are of high importance for the understanding of astrophysical objects and technological applications such as inertial confinement fusion. In this work, we present extensive new \emph{ab initio} path integral Monte Carlo (PIMC) results for the electronic properties in the Coulomb potential of a fixed ionic configuration. This gives us new insights into the complex interplay between the electronic localization around the protons with their density response to an external harmonic perturbation. We find qualitative agreement between our simulation data and a heuristic model based on the assumption of a local uniform electron gas model, but important trends are not captured by this simplification. In addition to being interesting in their own right, we are convinced that our results will be of high value for future projects, such as the rigorous benchmarking of approximate theories for the simulation of WDM, most notably density functional theory.

Over the last century, antibiotics against bacterial infections have led
to increased life expectancy and quality of people worldwide. Yet the
WHO has brought attention to the increasing resistance development
of bacterial pathogens against antibiotics - many bacteria are already
multi-resistant. In the search for alternatives to classical antibiotics,
nanotechnology and nanoparticles (NP) are moving into the focus of
scientific research. Particular attention is paid to the Nano-silver (Ag-
NP), which has experienced an immense upswing in recent years and is
used in many medical products such as wound dressings or consumer
products. However, are Ag-NPs safe for health and the environment? To
tackle this challenge, conventional methods have been used to explore
nanoparticle resistance. Conversely, these methods have proven to be
limited in terms of labor, cost, and statistical power. In our work,
we intend to overcome these barriers by developing a droplet-based
microfluidic analytical platform as a tool to elucidate the impact and
biological influence of nanoparticles on living microorganisms with high
statistical evaluation and detection efficiency. This method allows the
separation of bacteria into single droplets, the generation of individual
bioreactors, and the screening of bacterial metabolism in the
presence of Ag-NP.

Over the last century, antibiotics against bacterial infections have led
to increased life expectancy and quality of people worldwide. Yet the
WHO has brought attention to the increasing resistance development
of bacterial pathogens against antibiotics - many bacteria are already
multi-resistant. In the search for alternatives to classical antibiotics,
nanotechnology and nanoparticles (NP) are moving into the focus of
scientific research. Particular attention is paid to the Nano-silver (Ag-
NP), which has experienced an immense upswing in recent years and is
used in many medical products such as wound dressings or consumer
products. However, are Ag-NPs safe for health and environment? To
tackle this challenge, conventional methods have been used to explore
nanoparticle resistance. Conversely, these methods have proven to be
limited in terms of labor, cost, and statistical power. In our work,
we intend to overcome these barriers by developing a droplet-based
microfluidic analytical platform as a tool to elucidate the impact and
biological influence of nanoparticles on living microorganisms with high
statistical evaluation and detection efficiency. This method allows the
separation of bacteria into single droplets, the generation of individual
bioreactors, and the screening of bacterial metabolism in the
presence of Ag-NP.

In this presentation we discuss our achievements on the use of fluidic activities for the detection of impact of nanoparticles on microorganisms.

Air pollution and the energy crisis are the two main driving forces behind the development of alternative, environmentally friendly methods of energy production. Photoactive materials can be used both to clean the air and to produce green hydrogen for clean energy. Transition metal oxides are one of the most considered materials for high-performance photocatalysis. In this work, we investigate the effect of millisecond flash lamp annealing (FLA) of TiO2 on the degradation of methyl blue (MB) and methyl orange (MO). To reduce the energy consumption of the TiO2 deposition process, the layers were made using magnetron sputtering at room temperature, followed by millisecond FLA. By controlling the flash energy input, we can tune the phase formation of TiO2 films from pure anatase to mixed anatase/rutile phases. Scanning electron microscopy, positron annihilation spectroscopy, photoluminescence and X-ray diffraction studies show that the crystal size and film quality increase with increasing annealing temperature. Photocatalytic experiments demonstrate that FLA-treated TiO2 films are active in degrading both MB and MO. This makes them attractive not only for the production of green hydrogen, but also for the purification of water from medical contaminants.

We report on the development of an ultrafast optical parametric amplifier (uOPA) front-end for the Petawatt High Energy Laser for heavy Ion eXperiments (PHELIX) and the Petawatt ENergy-Efficient Laser for Optical Plasma Experiments (PE NELOPE). This front-end delivers broadband and stable amplification up to 1 mJ per pulse while maintaining a high beam quality. Its implementation at PHELIX allowed to bypass a front-end amplifier that was known to be a source of pre-pulses. With the bypass, an amplified spontaneous emission (ASE) contrast of 4.9·10−13 and a pre-pulse c ntrast
of 6.2·10−11 could be realized. Due to its high stability, high beam quality and its versatile pump amplifier, the system
offers an alternative for high-gain regenerative amplifiers in the front-end of vario

Stationary electric energy storage systems can help balance temporal differences
in electricity supply and demand. With the increasing use of volatile electricity
sources, this task is becoming more important. Liquid metal and molten salt
batteries are high-temperature storage devices and one option for stationary
storage. They are based on the stable density stratification of a liquid alkali
metal, a fused salt and a molten heavy metal. Mediated by the high operating
temperature, which must be above the melting temperatures of the individual
phases, interfacial reactions are rapid and transport processes are fast. High
current and power densities can thus be reached. The completely liquid cell
interior enables conceptually simple scalability at the cell level, which suggests
favorable energy-related investment costs. Electrode and electrolyte layers possess
thicknesses in the millimeter range and consist either of pure metals or a small
number of components. Both properties will facilitate recycling considerably.
The battery concept enables the use of abundant and cost effective active
material combinations like Na-Zn. In contrast to most other battery systems,
fluid mechanical processes, which are closely coupled to charge transport and
transfer, are of relatively high importance. The talk will present selected physical
phenomena in liquid metal batteries as well as discuss their possible role in a
future energy system.

In April 2023, all German nuclear power plants (NPPs) will have been shut down. The final shutdown is followed by a post-operational phase in which measures can be carried out to prepare for the NPPs dismantling and decommissioning. One of the essential tasks in planning and preparing an NPP for decommissioning is to obtain precise knowledge of the activation levels in its reactor pressure vessel (RPV), the biological shielding, and other internal components. In that regard, a method based on the combined use of two Monte Carlo codes, MCNP6 and FLUKA2021, was developed to serve as a non-destructive tool for evaluating the activation in an NPP. The methodology is demonstrated through the activation calculations of selected components of a German pressurized water reactor (PWR), Germany's most common NPP type. In the first step, the MCNP6 code was used to calculate the neutron fluence rate characteristics in the studied component using a detailed 3D model of a German PWR. The neutron source defined in the model was based on burn-up calculations provided by the operator. The neutron fluence rate prediction capability of the MCNP6 model was validated using neutron fluence monitors placed inside two German PWRs. The validation studies showed that the MCNP6 model and neutron sources are reliable and suitable for evaluating the neutron radiation field in the reactor for the ensuing activation calculations. In the second step, the FLUKA2021 code was used to calculate the specific activity in the studied component using a 3D exact model of the component and complex source terms built based on the neutron fluence rate parameters computed using the MCNP6 code. The results of the calculations were obtained with great accuracy and can be used as guidelines for optimal planning of the discharged reactor components' disposal and storage.

For some years now, research on adsorptive separation of hydrogen isotopes such as deuterium (D) and
tritium (T) has been evolving with a view toward nuclear fusion. Experimental and theoretical investigations
show that H2 strongly binds to undercoordinated Cu+ sites and more strongly when one H2O ligand is added
to Cu+.[1] To understand the vibrational behavior that drives the hydrogen isotopologue selectivity of
Cu+(H2O)(H2)2 formation, harmonic and anharmonic vibrational spectra have been computed and compared
to infrared photodissociation (IRPD) spectroscopy results from the gas phase. Our calculations show that
geometries and harmonic frequencies at the MP2/def2-TZVPP level match CCSD(T)/aug-cc-pVTZ ones
very closely. Scaling the harmonic frequencies by a factor of 0.95 [2] improves the agreement with the
available experimental data, but fails to produce the combination bands. By contrast, anharmonic VPT2
calculations at the MP2/def2-TZVPP level not only predict these bands but they also reproduce the
experimental frequencies very well. In addition to that, we found a similar structure for Cu+(H2O)(H2)2 as a
previous study[1]: a planar arrangement with C2v symmetry (Figure 1) but with a significantly shorter
Cu+–H2 bond length (1.62 Å vs 1.71 Å). Finally, the obtained results show that CCSD(T) calculations are
not required and VPT2 frequencies at the MP2/def2-TZVPP level are identified as a particularly good
compromise for future modeling of the vibrational properties driving isotopologue-selective H2 adsorption
at undercoordinated Cu+ sites.

Reference
[1] Paul R. Kemper et al., J. Am. Chem. Soc., 120:51,13494-13502 (1998)
[2] N. Heine et al., J. Phys. Chem. Lett., 6(12):2298-2304 (2015)

Im Rahmen dieser Projektarbeit wurde ein Hochtemperaturwärmespeicher ausgelegt.
Beginnend mit einer überblicksartigen Darstellung der Anwendung und Einteilung von Wärmespeichern wird der Stand der Technik anhand ausgewählter Forschungsprojekte zu Festkörperwärmespeichern vorgestellt. Darauf aufbauend werden im folgenden Kapitel 3 das angewendete Konzept der Auslegung sowie die zugrundeliegenden Stoffeigenschaften des Festkörpermaterials und des eingesetzten Fluides erläutert.
In Kapitel 4 wird die überschlägige Auslegung anhand einer analytischen Berechnung vorge-stellt. Besonderes Augenmerk liegt dabei auf der Berechnung der Wärmestrahlung des eingesetzten Fluides CO2. Es ist festzustellen, dass bei Berücksichtigung der Wärmestrahlung der Aufheizvorgang bei Aufheizung von 400 °C auf (gemittelt) 900 °C für einen 20 m langen Speicher knapp 18 % schneller verläuft, als bei gleichen Bedingungen ohne Berücksichtigung der Wärmestrahlung. Bei einem 4 m langen Speicher verläuft der Aufheizvorgang sogar über 45 % schneller, da hier aufgrund der geringeren Länge die Exergieverluste bei Vernachlässigung der Wärmestrahlung deutlich höher sind.
Die präzise Berechnung des Aufheizvorgangs anhand einer numerischen Simulation wird in Kapitel 5 beschrieben. Auch hier liegt das besondere Augenmerk auf der Berechnung der Wärmestrahlung. Dafür werden verschiedene in dem Programm ANSYS CFX zur Verfügung stehende Berechnungsmethoden für Wärmestrahlung untersucht und die Discrete-Transfer-Methode als für diesen Fall geeignet ermittelt. Darüber hinaus stellt bei der Modellierung der großen Geometrie (Länge von 20 m), bei Berücksichtigung der Wärmestrahlung und einem feinen Netz der entstehende Berechnungsaufwand eine große Herausforderung dar. Durch die Betrachtung eines kürzeren Speichers mit einer Länge von 4 m kann der Berechnungsaufwand verringert und damit die Qualität der Berechnungsergebnisse erhöht werden. Anhand der numerischen Modellierung konnte die analytische Berechnung annäherungsweise bestätigt werden.
Zur Untersuchung des Einflusses des Designs auf das Aufheizverhalten wurde anhand der analytischen Berechnung eine Reihe von verschiedenen Querschnittsvarianten untersucht. Es
7 Zusammenfassung und Ausblick
67
zeigt sich, dass bei Beachten der volumetrischen Energiedichte des Speichers und des nötigen Volumenstroms je gespeicherter Energie, möglichst kleine Dimensionen verwendet werden sollten. Allerdings ist hierbei die Frage der mechanischen Festigkeit durch thermische Spannungen, insbesondere im Dauerbetrieb zu beachten, wodurch ein nicht bestimmbarer Grenzwert für die minimale Größe der Strukturen definiert wird. Zugleich wurde mit der numerischen Simulation der Effekt des Wärmewiderstandes im Festkörper untersucht, wobei für den untersuchten Wandstärkenbereich keine signifikanten Temperaturgradienten durch die Modellierung ermittelt werden konnten.
Ausblickend können neben der Untersuchung des Einflusses der Querschnittsabmessungen zusätzliche andere Betriebsparameter, wie z. B. die Strömungsgeschwindigkeit oder der Systemdruck, untersucht werden.
Darüber hinaus wäre die Modellierung eines gesamten Wärmespeichersystems mit Kreis-laufführung des Fluides sinnvoll, um die in der Modellierung entstehenden Exergieverluste ausschließen zu können. Damit einhergehend wäre für die Kreislaufführung die über die Zeit aufnehmbaren (elektrischen) Energieströme zum Aufheizen des Fluides von der Austrittstemperatur aus dem Speicher auf 1000 °C oder der nötige Volumenstrom zum Erreichen einer geforderten (elektrischen) Aufheizleistung nötig.
Weiterhin sollten durch eine experimentelle Untersuchung die Stoffeigenschaften des Festkörpermaterials verifiziert werden, da insbesondere die Wärmeleitfähigkeit der Keramik nur in einem sehr großen Bereich von 3,5 W/(m K) bis 35 W/(m K) gegeben ist. Für die Berechnung wurde auf der sicheren Seite liegend zwar der untere Wert dieses Bereiches verwendet, allerdings sind in anderen Literaturstellen [9] für Keramikmaterialen Werte in einer Größenordnung des oberen Wertebereichs angegeben (siehe Tabelle 2-1). Zusätzlich kann durch eine experimentelle Untersuchung die Problematik der mechanischen Festigkeit geprüft werden.

The COVID-19 pandemic caused by SARS-CoV-2 led to millions of infections and deaths worldwide. As this virus evolves rapidly, there is a high need for treatment options, which can win the race against new emerging variants of concern. Here, we describe a novel immunotherapeutic drug based on the SARS-CoV-2 entry receptor ACE2 and provide experimental evidence that it cannot only be used for (i) neutralization of SARS-CoV-2 in vitro and in SARS-CoV-2 infected animal models, but also for (ii) clearance of virus infected cells. For the latter purpose, we equipped the ACE2 decoy with an epitope tag. Thereby, we converted it to an adapter molecule which we successfully applied in the modular platforms UniMAB and UniCAR for retargeting of either unmodified or universal chimeric antigen receptor modified immune effector cells. Our results pave the way for a clinical application of this novel ACE2 decoy, which will clearly improve COVID-19 treatment.

In this work, we report on the preparation of Te-hyperdoped Si. The hyperdoped Si layers are homogeneous, do not show cellular breakdown, and have a flat surface. Based on the obtained materials, we demonstrate a room-temperature mid-wavelength infrared Si p-n photodiode working in photovoltaic mode. The fabricated photodiode exhibits enhanced performance, e.g. regarding spectral photoresponse, specific detectivity, bandwidth and response speed. Moreover, inherited from the high free carrier concentration, mid-infrared-localized surface plasmon resonances (LSPR) are also observed in hyperdoped Si. We show that the mid-infrared LSPR can be further enhanced and spectrally extended to the far-infrared range by fabricating two-dimensional arrays of micrometer-sized antennas on a Te-hyperdoped Si chip. Since Te-hyperdoped Si can also work as an infrared photodetector, we believe that our results will unlock the route toward the direct integration of plasmonic sensors within a one-chip CMOS platform, greatly advancing the possibility of mass manufacturing of Si-based infrared photonic systems.

Magneto-ionics, an emerging approach to manipulate magnetism that relies on voltage-driven ion motion, holds the promise to boost energy efficiency in information technologies such as spintronic devices or future non-von Neumann computing architectures. For this purpose, stability, reversibility, endurance, and ion motion rates need to be synergistically optimized. Among various ions, nitrogen has demonstrated superior magneto-ionic performance compared to classical species such as oxygen or lithium. Here, we show that ternary Co1−xFexN compound exhibits an unprecedented nitrogen magneto-ionic response. Partial substitution of Co by Fe in binary CoN is shown to be favorable in terms of generated magnetization, cyclability and ion motion rates. Specifically, the Co0.35Fe0.65N films exhibit an induced saturation magnetization of 1500 emu cm–3, a magneto-ionic rate of 35.5 emu cm–3 s–1 and
endurance exceeding 103 cycles. These values significantly surpass those of other existing nitride and oxide systems. This improvement can be attributed to the larger saturation magnetization of Co0.35Fe0.65 compared to individual Co and Fe, the nature and size of structural defects in as-grown films of different composition, and the dissimilar formation energies of Fe and Co with N in the various developed crystallographic structures.

In recent years the importance of the aqueous solvent in influencing protein structure, function, and dynamics has been recognized. Coupling of water molecules to the protein surface results in an interfacial region in which water molecules within this region have distinctly different properties than bulk water. However, the structure and dynamics within this interfacial region are still not easy to access experimentally. Terahertz (THz) spectroscopy has been shown to be a powerful tool to investigate solvent dynamics in bulk solutions. Radiation in the THz regime is directly sensitive to the low frequency collective intermolecular hydrogen-bonding vibrations of water (0.3-6 THz or 10-200 cm-1), and thus to any changes in the hydrogen-bonding network. Changes in these sub-picosecond collective motions, such as protein-water interactions, result in changes in the measured THz absorption. Individual hydrations shells of proteins have been shown to contribute largely to structure-function relationships and ultimately modulate the binding properties of proteins. Here the role of solvation dynamics in processes such as electron transport in protein complexes and enzymatic catalysis will be investigated.

Water possesses strong absorption in the THz range due to intermolecular vibrational modes in a network of hydrogen-bonded water molecules. Its THz response is also sensitive to the coupling of water to other molecules, i.e. the hydration shell of a protein. Probing the nonlinear properties of hydration water can provide insight into protein solvent dynamics, and in the case of intrinsically disordered proteins, its subsequent role in the liquid-liquid phase separation (LLPS). Such characterization at low THz frequencies (< 3 THz) remains yet limited, due to the scarcity of brilliant light sources in this range. Here, we present the nonlinear characterization at 0.5 THz of water and FUS protein solution in a liquid transmission cell, using a THz time-domain spectroscopy (THz-TDS) setup with the TELBE free electron laser source at HZDR. Our results show that the nonlinear absorption and refractive indices of the FUS protein solution differ from that of water, indicating a perturbed hydrogen bonding network.

In recent years the importance of the aqueous solvent in influencing protein structure, function, and dynamics has been recognized. Coupling of water molecules to the protein surface results in an interfacial region in which water molecules within this region have distinctly different properties than bulk water. However, the structure and dynamics within this interfacial region are still not easy to access experimentally. Terahertz (THz) spectroscopy has been shown to be a powerful tool to investigate solvent dynamics in bulk solutions. Radiation in the THz regime is directly sensitive to the low frequency collective intermolecular hydrogen-bonding vibrations of water (0.3-6 THz or 10-200 cm-1), and thus to any changes in the hydrogen-bonding network. Changes in these sub-picosecond collective motions, such as protein-water interactions, result in changes in the measured THz absorption. Individual hydrations shells of proteins have been shown to contribute largely to structure-function relationships and ultimately modulate the binding properties of proteins. Here the role of solvation dynamics in the liquid-liquid phase separation (LLPS) of the intrinsically disordered protein fused in sarcoma (FUS) is probed. Characterization of the hydrogen bonding network reveals that water solvating hydrophobic groups is stripped away in the membrane-less FUS biomolecular condensates. Additionally, water left inside of the biomolecular condensates is highly constrained, indicative of a population of bound hydration water. These results uncover the vital role of hydration water in LLPS: the entropically favorable release of unfavorable hydration water serves as a driving force for LLPS.

In recent years the importance of the aqueous solvent in influencing protein structure, function, and dynamics has been recognized. Coupling of water molecules to the protein surface results in an interfacial region in which water molecules within this region have distinctly different properties than bulk water. However, the structure and dynamics within this interfacial region are still not easy to access experimentally. Terahertz (THz) spectroscopy has been shown to be a powerful tool to investigate solvent dynamics in bulk solutions. Radiation in the THz regime is directly sensitive to the low frequency collective intermolecular hydrogen-bonding vibrations of water (0.3-6 THz or 10-200 cm-1), and thus to any changes in the hydrogen-bonding network. Here the role of solvation dynamics in the liquid-liquid phase separation (LLPS) of the intrinsically disordered protein fused in sarcoma (FUS) is probed. Characterization of the hydrogen bonding network reveals that water solvating hydrophobic groups is stripped away in the membrane-less FUS biomolecular condensates. Additionally, water left inside of the biomolecular condensates is highly constrained, indicative of a population of bound hydration water. These results uncover the vital role of hydration water in LLPS: the entropically favorable release of unfavorable hydration water serves as a driving force for LLPS.

Rapid access to accurate equation-of-state (EOS) data is crucial in the warm-dense matter regime, as it is employed in various applications, such as providing input for hydrodynamics codes to model inertial confinement fusion processes. In this study, we develop neural network models for predicting the EOS based on first-principles data. The first model utilizes basic physical properties, while the second model incorporates more sophisticated physical information, using output from average-atom calculations as features. Average-atom models are often noted for providing a reasonable balance of accuracy and speed; however, our comparison of average-atom models and higher-fidelity calculations shows that more accurate models are required in the warm-dense matter regime. Both the neural network models we propose, particularly the physics-enhanced one, demonstrate significant potential as accurate and efficient methods for computing EOS data in warm-dense matter.

Simulations and diagnostics of high-energy-density plasmas and warm dense matter rely on models of material response properties, both static and dynamic (frequency-dependent). Here, we systematically investigate variations in dynamic electron–ion collision frequencies ν(ω) in warm dense matter using data from a self-consistent-field average-atom model. We show that including the full quantum density of states, strong collisions, and inelastic collisions lead to significant changes in ν(ω) ⁠. These changes result in red shifts and broadening of the plasmon peak in the dynamic structure factor, an effect observable in x-ray Thomson scattering spectra, and modify stopping powers around the Bragg peak. These changes improve the agreement of computationally efficient average-atom models with first-principles time-dependent density functional theory in warm dense aluminum, carbon, and deuterium.

For CMS, Heterogeneous Computing is a powerful tool to face the computational challenges posed by the upgrades of the LHC, and will be used in production at the High Level Trigger during Run 3. In principle, to offload the computational work on non-CPU resources, while retaining their performance, different implementations of the same code are required. This would introduce code-duplication which is not sustainable in terms of maintainability and testability of the software. Performance portability libraries allow to write code once and run it on different architectures with close-to-native performance. The CMS experiment is evaluating performance portability libraries for the near term future.

The Helmholtz Metadata Collaboration (HMC) is an initiative that provides support for researchers within the Helmholtz Association to create, manage, and use metadata effectively and to establish FAIR data as the new standard for working with data in science. The HMC provides services, advice, and training on how to identify and apply appropriate metadata standards and schemas, how to design and implement metadata workflows, and to develop strategies for data discovery and reuse. Six metadata hubs according to the Helmholtz association's six research areas have been established to meet the specific needs of the respective communities. This presentation is given by the Hub Energy to communicate the HMC's efforts and offers for the research data in the field Energy and to its research community

Open Science implies sharing data for the reuse in other research context. For data to be reusable, it needs proper documentation, which is usually done through metadata. Metadata and its management are a critical component of ensuring that energy data is FAIR (Findable, Accessible, Interoperable, and Reusable). Metadata is information about data, such as its format, origin, and purpose, that helps users understand and use the data effectively.
One of the key challenges of managing energy data is the variety of sources, including sensors, simulations, and experiments. This means that the data may be in different formats, with different levels of detail, and with different levels of quality. Metadata help to standardize and harmonize the data, making it easier to find, access, and use them.
Another key benefit of metadata management is that it allows energy data to be more easily shared and reused. By providing detailed information about the data, including its provenance, quality, and limitations, metadata management helps to ensure that the data is used appropriately. This is particularly important in the energy sector, where data is often used to guide policy and investment decisions.
The use of standard vocabularies and ontologies is beneficial for describing the available research data in a consistent way, making it easier to search and retrieve them.
In conclusion, elaborated metadata management in a way described above, is an essential component of ensuring that energy data is compatible with the principles of FAIR.
The Helmholtz Metadata Collaboration (HMC) is an initiative that provides support for researchers within the Helmholtz Association to create, manage, and use metadata effectively and to establish FAIR data as the new standard for working with data in science. The HMC provides services, advice, and training on how to identify and apply appropriate metadata standards and schemas, how to design and implement metadata workflows, and to develop strategies for data discovery and reuse.
The HMC can support researchers in various ways, such as:
1. Standard and schema identification: The HMC can help researchers to identify the most suitable metadata standards and schemas for their research data, and to apply them correctly. This will ensure that data can be easily discovered and reused by others.
2. Metadata workflows: The HMC can assist researchers in designing and implementing metadata workflows that are tailored to their specific research needs. This can help to ensure that data is properly described and indexed, and that metadata is created in a consistent and accurate manner.
3. Data discovery and reuse: The HMC can help researchers to develop strategies for making their data discoverable and reusable by others. This includes creating metadata records, depositing data in repositories, and making data available through data catalogs or research data management platforms.
4. Tool and service integration: The HMC can support researchers in integrating their metadata with other data management tools and services, such as data repositories, data catalogs, and research data management platforms. This will help to ensure that data is easily discoverable, accessible, and reusable.
5. Providing training and support: The HMC offers training and support to researchers to help them create, manage, and use metadata effectively. This is done by offering a variety of workshops, webinars, and one-on-one support.
Overall, the HMC aims to foster a culture of good data management practices within the Helmholtz community and to support the discovery, access, and reuse of research data across the Helmholtz association. The HMC is committed to help researchers in their metadata management processes, and to make sure that their data is discoverable, accessible, and reusable by others. Six metadata hubs according to the Helmholtz association's six research areas have been established to meet the specific needs of the respective communities. This presentation is given by the Hub Energy to communicate the HMC's efforts and offers for the research data in the field Energy and to its research community

Due to Germany’s nuclear phase-out, the decommissioning of nuclear power plants (NPPs) and final disposal of structural materials becomes an increasingly important task. The project WERREBA (German acronym for Ways for Efficient Decommissioning of Reactor Components and Concrete Shielding) aimed at the reliable determination of radionuclides produced by neutron activation, the activity as a function of time since shutdown and investigating subsequent radionuclide mobility. In the scope of the project, activity measurements and calculations were carried out for samples of the reactor pressure vessel and the concrete shielding of unit 2 of the Greifswald NPP shut down in 1990 during the German reunification.
Both measurements and calculations show that the highest specific activity of the RPV is found in a small region adjacent to the reactor core. Several decades after shutdown, Cobalt-60 (half-live time 5.27 y) is the dominating nuclide. A prolongation of the interim storage time by several years, i.e. caused by the delayed start of the operation phase of the Konrad repository, will therefore lead to a significant reduction of the activity of the structural materials. The specific activity decreases by 4 to 5 orders of magnitude with increasing distance to the reactor core. It is expected that a specific clearance or even unrestricted clearance will be possible for parts of the RPV after several decades of interim storage time.
Unit 2 of the Greifswald NPP is a first-generation VVER-440 (Russian acronym for pressurized water reactor with light water as coolant and moderator) which features an annular water tank. A neutron radiation field calculation using the radiation transport code MCNP reveals that the maximum neutron fluence in the concrete component is located in the floor just below the RPV. The concrete structures closest to the reactor core are shielded efficiently against neutron radiation by the annular water tank.
Measured and calculated specific activities of Europium-152, Europium-154 and Cobalt-60 for the cement screed at the position of the maximum neutron fluence are surprisingly low compared to recently published calculations and measurements for VVER-440 of the second generation. This is attributed primarily to the distinct design of the first generation VVER-440/230 compared with the second generation VVER-440/213 without annular water tank.

Gas Taylor bubbles in millichannels are characterized by an elongated shape, bullet-shaped bubbles nose and a comparatively flat bottom. Because of dominant interfacial tension forces, such bubbles occupy most of the cross-sectional area of the tube. There exist many experimental or numerical investigations. Most of them consider Taylor bubbles moving in a straight pipe with constant cross-section, such as a tube or square duct. In this work, we report a new finding for a vertical tube equipped with a geometrical singularity. The dynamics of an individual Taylor bubble in a counter-current flow is presently investigated. We find that a small tube constriction, with only 5 % obstruction, has a significant influence on the flow and interfacial dynamics. Various regimes, characterized for increasing channel obstruction, are here established. High experimental and numerical reproducibility is observed.

Light microscopy is a widespread and inexpensive imaging technique facilitating biomedical discovery and diagnostics. However, light diffraction barrier and imperfections in optics limit the level of detail of the acquired images. The details lost can be reconstructed among others by deep learning models. Yet, deep learning models are prone to introduce artefacts and hallucinations into the reconstruction. Recent state-of-the-art image synthesis models like the denoising diffusion probabilistic models (DDPMs) are no exception to this. We propose to address this by incorporating the physical problem of microscopy image formation into the model's loss function. To overcome the lack of microscopy data, we train this model with synthetic data. We simulate the effects of the microscope optics through the theoretical point spread function and varying the noise levels to obtain synthetic data. Furthermore, we incorporate the physical model of a light microscope into the reverse process of a conditioned DDPM proposing a physics-informed DDPM (PI-DDPM). We show consistent improvement and artefact reductions when compared to model-based methods, deep-learning regression methods and regular conditioned DDPMs.

The coupling energies between the buckled dimers of the Si(001) surface were determined through analysis of the anisotropic critical behavior of its order-disorder phase transition. Spot profiles in high-resolution low-energy electron diffraction as a function of temperature were analyzed within the framework of the anisotropic two-dimensional Ising model. The validity of this approach is justified by the large ratio of correlation lengths, ζ +/ζ∥+=5.2 of the fluctuating c(4×2) Domains above the critical temperature Tc=(190.6±10) K. We obtain effective couplings J∥=(-24.9±1.3) meV along the dimer rows and J⊥=(-0.8±0.1) meV across the dimer rows, i.e., antiferromagneticlike coupling of the dimers with c(4×2) symmetry.

Theory suggests that in high-energy elastic hadron+hadron scattering, t-channel exchange of a family of colourless crossingodd
states – the odderon – may generate differences between pp¯ and pp cross-sections in the neighbourhood of the
diffractive minimum. Using a mathematical approach based on interpolation via continued fractions enhanced by statistical
sampling, we develop robust comparisons between pp¯ elastic differential cross-sections measured at √s=1.96 TeV by the
D0 Collaboration at the Tevatron and function-form-unbiased extrapolations to this energy of kindred pp measurements at
√s/TeV=2.76,7,8,13 by the TOTEM Collaboration at the LHC and a combination of these data with earlier cross-section
measurements at √s/GeV=23.5,30.7,44.7,52.8,62.5 made at the intersecting storage rings. Focusing on a domain that
straddles the diffractive minimum in the pp¯ and pp cross-sections, we find that these two cross-sections differ at the
(2.2−2.6)σ level; hence, supply evidence with this level of significance for the existence of the odderon. If combined with
evidence obtained through different experiment-theory comparisons, whose significance is reported to lie in the range
(3.4−4.6)σ, one arrives at a (4.0−5.2)σ signal for the odderon.

B20-CoSi is a newly discovered Weyl semimetal that crystallizes into a non-centrosymmetric crystal structure. However, the investigation of B20-CoSi has so far been focused on bulk materials, whereas the growth of thin films on technology-relevant substrates is a prerequisite for most practical applications. In this study, we have used millisecond-range flash-lamp annealing, a non-equilibrium solid-state reaction, to grow B20-CoSi thin films. By optimizing the annealing parameters, we were able to obtain thin films with a pure B20-CoSi phase. The magnetic and transport measurements indicate the appearance of the charge density wave and the chiral anomaly. Our work presents a promising method for preparing thin films of most binary B20 transition-metal silicides, which are candidates for topological Weyl semimetals.

Solute channel formation introduces compositional and microstructural variations in a range of processes, from metallic alloy solidification to salt fingers in ocean and water reservoir flows. Applying an external magnetic field interacts with thermoelectric currents at solid/liquid interfaces generating additional flow fields. This thermoelectric (TE) magnetohydrodynamic (TEMHD) effect can impact on solute channel formation ,via a mechanism recently drawing increasing attention. To investigate this phenomenon, we combined in situ synchrotron X-ray imaging and Parallel Cellular Automata Lattice Boltzmann method-based numerical simulations to study the characteristics of flow and solute transport under TEMHD. Observations suggest the macroscopic TEMHD flow appearing ahead of the solidification front, coupled with the microscopic TEMHD flow arising within the mushy zone are the primary mechanisms controlling plume migration and channel bias. Two TE regimes were revealed, each with distinctive mechanisms that dominate the flow. Further, we show that grain orientation modifies solute flow through anisotropic permeability. These insights led to a proposed strategy for producing solute channel-free solidification using a time-modulated magnetic field.

Monoclinic gallium oxide (β-Ga2O3) exhibits the highest chemical and thermal
stability among its four other polymorphs, making it a highly promising
semiconductor material for various applications such as power electronics,
optoelectronics, and batteries, thanks to its exceptionally wide bandgap of around
4.7 eV. However, the challenge lies in effectively managing the metastable
polymorph phases and dealing with underdeveloped nanoscale fabrication
techniques. Our objective is to leverage the potential of ion-beam-induced polymorph
conversion to gain a comprehensive understanding and control over the crystalline
structure. By utilizing focused ion beams (FIBs), we aim to pioneer new fabrication
methods for generating single-phase polymorph layers, buried layers, multilayers,
and diverse nanostructures within Ga2O3. The primary focus of this research is to
enhance our knowledge and control of polymorph conversion, with a particular
emphasis on spatially precise modifications using focused ion beams.
Most semiconductor materials transform into an amorphous phase under a high
dose of ion irradiation, however, Ga2O3 is an exceptionally radiation-tolerant material
even at high fluences of ion irradiation. The conversion from the stable to the
metastable phase seems to be enabled by the formation of a defective spinel
structure in which the oxygen lattice remains unchanged [1]. It has been found that
sub-lattice requires a certain level of damage accumulation, specifically
displacement per atom (DPA), to transform into γ-phase [1].
Here, we used Helium Ion Microscopy (HIM) and liquid metal alloy ion source
(LMAIS) FIBs to locally irradiate (-201) -oriented β-Ga2O3 substrate with different
ions (Ne, Ga, Co, Nd, Si, Au, In) to induce the polymorph transition. Locally and
spatially resolved characterization was performed by Electron Backscatter Diffraction
(EBSD) and analyzing the Kikuchi patterns. Furthermore, Doppler Broadening
Variable Energy Positron Annihilation Spectroscopy (DB-VEPAS) and Rutherford
Backscatter Spectrometry (RBS) were performed for neon-broad-beam-irradiated
implants to better understand the fluence-dependent creation and distribution of
defects. Transmission Electron Microscopy (TEM) images provide information about
the interfaces between different polymorphs of Ga2O3. The first results indicate that
the damage/strain created by the Ne+, Co+, and Si+ FIB irradiations leads to a local
transformation of β- Ga2O3 to γ- Ga2O3 and the structure maintains its crystallinity
up to high-fluence FIB irradiation instead of being amorphized.

To investigate a phase transition around 2 K in Er₃Ru₄Al₁₂ with a distorted kagome lattice, we conducted the specific heat, magnetic susceptibility, and ultrasonic measurements. At zero field a sharp peak of the specific heat is observed at T_N = 2.2 K, implying a phase transition. The magnetic susceptibility in a field applied along [100], which is a magnetically easy direction, remains almost the same value below T_N. The longitudinal elastic modulus, C₁₁, shows an obvious hardening at T_N, and TN decreases up to 0.4 T as the magnetic field applied along [100] increases, suggesting an antiferromagnetic ordering. In the magnetic field dependence of C₁₁ at 0.5 K, we discovered two abrupt softenings at 0.25 T and around 0.47 T, proposing that the antiferromagnetic phase boundary closes around 0.47 T in the field applied along [100]. Other phase boundary exists around 0.25 T in the ordered state