Publications Repository - Helmholtz-Zentrum Dresden-Rossendorf

We present a study on the transport and materials properties of aluminum spanning from ambient to warm dense matter conditions using a machine-learned interatomic potential (ML-IAP). Prior research has utilized ML-IAPs to simulate phenomena in warm dense matter, but these potentials have often been calibrated for a narrow range of temperature and pressures. In contrast, we train a single ML-IAP over a wide range of temperatures, using density functional theory molecular dynamics (DFT-MD) data. Our approach overcomes computational limitations of DFT-MD simulations, enabling us to study transport and materials properties of matter at higher temperatures and longer
time scales. We demonstrate the ML-IAP transferability across a wide range of temperatures using molecular-dynamics (MD) by examining the thermal conductivity, diffusion coefficient, viscosity, sound velocity, and ion-ion structure factor of aluminum up to about 60,000 K, where we find good agreement with previous theoretical data.

The phonon magnetochiral effect (MChE) is the nonreciprocal acoustic and thermal transports of phonons caused by the simultaneous breaking of the mirror and time-reversal symmetries. So far, the phonon MChE has been observed only in a ferrimagnetic insulator Cu₂OSeO₃, where the nonreciprocal response disappears above the Curie temperature of 58 K. Here, we study the nonreciprocal acoustic properties of a room-temperature ferromagnet Co₉Zn₉Mn₂ for unveiling the phonon MChE close to room temperature. Surprisingly, the nonreciprocity in this metallic compound is enhanced at higher temperatures and observed up to 250 K. This clear contrast between insulating Cu₂OSeO₃ and metallic Co₉Zn₉Mn₂ suggests that metallic magnets have a mechanism to enhance the nonreciprocity at higher temperatures. From the ultrasound and microwave-spectroscopy experiments, we conclude that the magnitude of the phonon MChE of Co₉Zn₉Mn₂ mostly depends on the Gilbert damping, which increases at low temperatures and hinders the magnon-phonon hybridization. Our results suggest that the phonon nonreciprocity could be further enhanced by engineering the magnon band of materials.

In magnetischen Materialien „frieren“ die magnetischen Momente üblicherweise in wohlgeordneten oder glasartigen Strukturen ein. Quanteneffekte können dazu führen, dass diese Strukturen „schmelzen“ und die Spinflüssigkeit selbst am absoluten Nullpunkt nicht ordnet.

We investigate the morphologies of the Ge(001) surface that are produced by bombardment with a normally incident, broad argon ion beam at sample temperatures above the recrystallization temperature. Two previously-observed kinds of topographies are seen, i.e., patterns consisting of upright and inverted rectangular pyramids, as well as patterns composed of shallow, isotropic basins. In addition, we observe the formation of an unexpected third type of pattern for intermediate values of the temperature, ion energy and ion flux. In this type of intermediate morphology, isolated peaks with rectangular cross sections stand above a landscape of shallow, rounded basins. We also extend past theoretical work to include a second order correction term that comes from the curvature dependence of the sputter yield. For a range of parameter values, the resulting continuum model of the surface dynamics produces patterns that are remarkably similar to the intermediate morphologies we observe in our experiments. The formation of the isolated peaks is the result of a term that is not ordinarily included in the equation of motion, a second order correction to the curvature dependence of the sputter yield.

Several technologies, including photodetection, imaging and data communication, could greatly benefit from the availability of fast and controllable conversion of terahertz (THz) light to visible light. Here, we demonstrate that the exceptional properties and dynamics of electronic heat in graphene allow for THz-to-visible conversion, which is switchable at a sub-nanosecond timescale. We show a tunable on/off ratio of more than 30 for the emitted visible light, achieved through electrical gating using a gate voltage on the order of one Volt. We also demonstrate that a grating-graphene metamaterial leads to an increase in THz-induced emitted power in the visible range by two orders of magnitude. The experimental results are in agreement with a thermodynamic model that describes black-body radiation from the electron system heated through intraband Drude absorption of THz light. These results provide a promising route towards novel functionalities of optoelectronic technologies in the THz regime.

Strain and temperature are important physiological parameters for health monitoring, providing access to the respiration state, movement of joints and inflammation processes. The challenge for smart wearables is to unambiguously discriminate strain and temperature using a single sensor element assuring a high degree of sensor integration. Here, we report a dual-modal sensor with two electrodes and tubular mechanically heterogeneous structure enabling simultaneous sensing of strain and temperature without cross-talk. The sensor structure consists of a thermocouple coiled around an elastic strain-to-magnetic induction conversion unit, revealing a giant magnetoelastic effect, and accommodating a magnetic amorphous wire. The thermocouple provides access to temperature and its coil structure allows to measure impedance changes caused by the applied strain. The dual-modal sensor also exhibits interference-free temperature sensing performance with high coefficient of 54.49 μV/°C, low strain and temperature detection limits of 0.1% and 0.1 °C, respectively. We demonstrate the use of these sensors in smart textiles to monitor continuously breathing, body movement, body temperature and ambient temperature. The developed multifunctional wearable sensor is needed for applications in early disease prevention, health monitoring and interactive electronics as well as for smart prosthetics and intelligent soft robotics.

Monazites are rare earth phosphates that are potential host matrices for the immobilization of actinides in high-level radioactive waste streams. This is due to their ability to incorporate various cations through different substitution mechanisms as well as their radiation resistance as observed in natural monazite mineral samples. In this study, LnPO4 monazite ceramics and single crystals doped with 500 ppm EuIII as a luminescent probe were irradiated with heavy ions to simulate the recoil of daughter products that occurs during alpha decay of the actinides. More specifically, irradiation experiments were conducted either with 14 MeV Au ions at fluences ranging from 5×1013 – 1×1015 ions/cm2 or with swift 1.7 GeV Au ions at fluences of 5×1011 – 2×1012 ions/cm2.
Irradiated monazite ceramics were analyzed with electron microscopy (SEM), vertical scanning interferometry (VSI), grazing incidence diffraction (GID), Raman spectroscopy, and luminescence spectroscopy to probe long and short range order of the monazite microstructure.
SEM micrographs and VSI data show clear damage of the irradiated regions of the ceramics, in the form of swollen grains and grain boundaries. GID images and powder patterns reveal diffuse scattering and amorphous contributions in irradiated samples. Solid solution compositions show larger damage than corresponding monazite endmembers, while polycrystalline and single crystal samples show similar level of amorphization. In the local coordination environments, Raman spectra of irradiated samples display a shoulder on the ν1 peak, indicating disruption in the vibrational modes of the phosphate tetrahedra. Confocal measurements of the swift heavy-ion irradiated monazites show full amorphization of the surface layers of the monazites samples, and increasing crystallinity with increasing sample depth. Luminescence data illustrate differences in the local LnO9 polyhedral environment in the monazites with irradiation. Integrated excitation spectra show a difference in the intensity and position of the excitation peak with irradiation. Especially single crystal data show a systematic decrease of the local site symmetry of the Eu3+ cation, and a general broadening of emission spectra, indicative for reduced local order following amorphization.

This contribution provides an overview of a current research network funded by the German Federal Ministry of Education and Research (BMBF), entitled “Fundamental investigations of actinide immobilization by incorporation into solid phases relevant for final disposal” – AcE. The AcE project aims at understanding the incorporation and immobilization of actinides (An) in crystalline, repository-relevant solid phases, such as zirconia (ZrO2) and UO2, but also in zircon (ZrSiO4), pyrochlores (Ln2Zr2O7) and orthophosphates of the monazite type (LnPO4), which may find use as host matrices for the immobilization and safe disposal of high-level waste streams.
Recent studies by the AcE-project consortium, addressing the structure, properties, and the radiation tolerance of monazites and Zr(IV)-based solid phases containing actinides or their surrogates from the lanthanide series will be presented. Material synthesis strategies in the AcE project have aimed at generating single-phase solid solutions in the form of polycrystalline powders, dense ceramics, and single crystals. Structural studies using powder X-ray diffraction at ambient conditions, but also at high temperatures and pressures have been complemented with a wide range of microscopic and spectroscopic techniques to address differences between the host- and dopant environments in the solid matrices at ambient and extreme conditions. The radiation tolerance of the synthetic solid phases have been investigated by combining external heavy-ion irradiation of inactive Ln-doped materials and in situ self-irradiation of 241Am-doped Zr(IV)-phases with monoclinic, cubic defect fluorite and pyrochlore structures. The latter experiments have been conducted in joint efforts with the Joint Research Center in Karlsruhe within the ActUsLab programme.

Nuclear energy provides a widely applied carbon-reduced energy source. Following operation, the spent nuclear fuel (SNF), containing a mixture of radiotoxic elements such as transuranics, needs to be safely disposed of. Safe storage of SNF in a deep geological repository (DGR) relies on multiple engineered and natural retention barriers to prevent environmental contamination. In this context, zirconia (ZrO2) formed on the SNF rod cladding, could be employed as an engineered barrier for immobilization of radionuclides via structural incorporation. This study investigates the incorporation of Eu3+ and Cm3+, representatives for trivalent transuranics, into zirconia by co-precipitation and crystallization in aqueous solution at 80 °C. Complementary structural and microstructural characterization has been carried out by Powder X-ray Diffraction (PXRD), spectrum imaging analysis based on Energy-Dispersive X-ray Spectroscopy in Scanning Transmission Electron Microscopy mode (STEM-EDXS), and luminescence spectroscopy. The results reveal the association of the dopants with the zirconia particles and elucidate the presence of distinct bulk and superficially incorporated species. Hydrothermal aging for up to 460 days in alkaline media points to great stability of these incorporated species after initial crystallization, with no indication of phase segregation or release of Eu3+ and Cm3+ over time. These results suggest that zirconia would be a suitable technical retention barrier for mobilized trivalent actinides in a DGR.

Spent nuclear fuel (SNF) from nuclear reactors operating worldwide will be disposed of directly or after reprocessing. In the latter case, generation of specific waste streams, e.g. minor actinide-containing waste, may require immobilization in durable, crystalline waste forms. Such candidate phases for the immobilization of (minor) actinides are various Zr(IV)-bearing solid phases like pyrochlore and zirconia. In addition to their use as potential ceramic waste matrices or inert matrix fuels for e.g. the incineration of waste plutonium, Zr-bearing phases, especially ZrO2, may be of importance as corrosion products in the dissolution of Zircaloy cladding material of SNF rods. ZrO2 is monoclinic phase (P21/c) at ambient conditions, and transforms into tetragonal (P4_2/nmc) and cubic phases (Fm3 ̅m) at high temperatures of around 1200 °C and 2370 °C, respectively. However, particle size effects, the incorporation of foreign ions such as the actinides, as well as high radiation fields are also known to influence the stability fields of the polymorphs.
This contribution provides an overview of recent studies addressing the structure, properties and the radiation tolerance of Zr(IV)-based solid phases containing actinides and their surrogates from the lanthanide series. Synthesis strategies and structural transformations taking place as a result of An(IV) or Ln(IV) incorporation in ZrO2 will be presented. Combining bulk structural characterization using powder X-ray diffraction (PXRD) with spectroscopic investigations, differences between the host- and dopant environments can be explored. In addition, radiation damage studies combining external heavy-ion irradiation of inactive Ln-doped materials and in situ self-irradiation of recently synthesized 241Am-doped Zr(IV)-phases with monoclinic, cubic defect fluorite and pyrochlore structures, will be addressed.

The accurate identification of the transition velocities Utrans in bubble columns (BCs) is very important for their effective design, operation and scale-up. In this work, a novel parameter (new hybrid index (NHI)) has been developed and successfully applied to gas holdup and pressure fluctuations recorded in various BCs operated with water and aqueous solutions of alcohols (ethanol and iso-propanol).
The first Utrans has been identified on the basis of a well-pronounced local NHI minimum, whereas the second Utrans has been distinguished by the point, from which the NHI profile levels off. It has been concluded that the main Utrans depend on the type of gas-liquid system and sparger used. A set of several Utrans has been reported.

The vibrational spectra of the copper(i) cation-dihydrogen complexes Cu+(H2)4, Cu+(D2)4 and Cu+(D2)3H2 are studied using cryogenic ion trap vibrational spectroscopy in combination with quantum chemical calculations. The infrared photodissociation (IRPD) spectra (2500-7300 cm−1) are assigned based on a comparison to IR spectra calculated using vibrational second-order perturbation theory (VPT2). The IRPD spectra exhibit ≈60 cm−1 broad bands that lack rotational resolution, indicative of rather floppy complexes even at an ion trap temperature of 10 K. The observed vibrational features are assigned to the excitations of dihydrogen stretching fundamentals, combination bands of these fundamentals with low energy excitations as well as overtone excitations of a minimum-energy structure with Cs symmetry. The three distinct dihydrogen positions present in the structure can interconvert via pseudorotations with energy barriers less than 10 cm−1, far below the zero-point vibrational energy. Ab initio Born-Oppenheimer molecular dynamics (BOMD) simulations confirm the fluxional behavior of these complexes and yield an upper limit for the timeframe of the pseudorotation on the order of 10 ps. For Cu+(D2)3H2, the H2 and D2 loss channels yield different IRPD spectra indicating non-ergodic behavior. © 2023 The Royal Society of Chemistry.

The EU Horizon 2020 Framework-funded Standardized Treatment and Outcome Platform for Stereotactic Therapy Of Re-entrant tachycardia by a Multidisciplinary (STOPSTORM) consortium has been established as a large research network for investigating STereotactic Arrhythmia Radioablation (STAR) for ventricular tachycardia (VT). The aim is to provide a pooled treatment database to evaluate patterns of practice and outcomes of STAR and finally to harmonize STAR within Europe. The consortium comprises 31 clinical and research institutions. The project is divided into nine work packages (WPs): (i) observational cohort; (ii) standardization and harmonization of target delineation; (iii) harmonized prospective cohort; (iv) quality assurance (QA); (v) analysis and evaluation; (vi, ix) ethics and regulations; and (vii, viii) project coordination and dissemination. To provide a review of current clinical STAR practice in Europe, a comprehensive questionnaire was performed at project start. The STOPSTORM Institutions' experience in VT catheter ablation (83% ≥ 20 ann.) and stereotactic body radiotherapy (59% > 200 ann.) was adequate, and 84 STAR treatments were performed until project launch, while 8/22 centres already recruited VT patients in national clinical trials. The majority currently base their target definition on mapping during VT (96%) and/or pace mapping (75%), reduced voltage areas (63%), or late ventricular potentials (75%) during sinus rhythm. The majority currently apply a single-fraction dose of 25 Gy while planning techniques and dose prescription methods vary greatly. The current clinical STAR practice in the STOPSTORM consortium highlights potential areas of optimization and harmonization for substrate mapping, target delineation, motion management, dosimetry, and QA, which will be addressed in the various WPs. © The Author(s) 2023. Published by Oxford University Press on behalf of the European Society of Cardiology.

Electrically conductive coordination polymers and metal–organic frameworks are attractive emerging electroactive materials for (opto-)electronics. However, developing semiconducting coordination polymers with high charge carrier mobility for devices remains a major challenge, urgently requiring the rational design of ligands and topological networks with desired electronic structures. Herein, we demonstrate a strategy for synthesizing high-mobility semiconducting conjugated coordination polymers (c-CPs) utilizing novel conjugated ligands with D2h symmetry, namely, “4 + 2” phenyl ligands. Compared with the conventional phenyl ligands with C6h symmetry, the reduced symmetry of the “4 + 2” ligands leads to anisotropic coordination in the formation of c-CPs. Consequently, we successfully achieve a single-crystalline three-dimensional (3D) c-CP Cu4DHTTB (DHTTB = 2,5-dihydroxy-1,3,4,6-tetrathiolbenzene), containing orthogonal ribbon-like π–d conjugated chains rather than 2D conjugated layers. DFT calculation suggests that the resulting Cu4DHTTB exhibits a small band gap (∼0.2 eV), strongly dispersive energy bands near the Fermi level with a low electron-hole reduced effective mass (∼0.2m0*). Furthermore, the four-probe method reveals a semiconducting behavior with a decent conductivity of 0.2 S/cm. Thermopower measurement suggests that it is a p-type semiconductor. Ultrafast terahertz photoconductivity measurements confirm Cu4DHTTB’s semiconducting nature and demonstrate the Drude-type transport with high charge carrier mobilities up to 88 ± 15 cm2 V–1 s–1, outperforming the conductive 3D coordination polymers reported till date. This molecular design strategy for constructing high-mobility semiconducting c-CPs lays the foundation for achieving high-performance c-CP-based (opto-)electronics.

In this Letter, we report a tailored 532/1064-nm demultiplexer based on a multimode interference (MMI) coupler with an efficiency of 100%. The device structure is designed according to the self-imaging principle, and the propagation and the wavelength division performance are simulated by the beam propagation method. The demultiplexer is fabricated in a y-cut LiNbO3 crystal by femtosecond laser direct writing (FLDW) combined with the ion implantation technique. The end-face coupling system is used to measure the near field intensity distribution, and the spectra collected from the output ports are obtained by spectrometers. The simulated and the experimental results indicate that the customized demultiplexer in the LiNbO3 crystal presents excellent wavelength division performance operating at 532 nm and 1064 nm. This work demonstrates the application potential of FLDW technology for developing miniaturized photonic components and provides a new strategy for fabricating high-efficiency integrated wavelength division devices on an optical monocrystalline platform.

The electric E1 and magnetic M 1 dipole responses of the N = Z nucleus 24 Mg were investigated in an inelastic photon scattering experiment. The 13.0 MeV electrons, which were used to produce the unpolarised bremsstrahlung in the entrance channel of the 24 Mg(γγ) reaction, were delivered by the ELBE accelerator of the Helmholtz-Zentrum Dresden-Rossendorf. The collimated bremsstrahlung photons excited one J = 1-, four J = 1+ , and six J = 2+ states in 24 Mg. De-excitation γ rays were detected using the four high-purity germanium detectors of the γELBE setup, which is dedicated to nuclear resonance fluorescence experiments. In the energy region up to 13.0 MeV a total B(M1)_up = 2.7(3) µ_N ² is observed, but this N = Z nucleus exhibits only marginal E1 strength of less than B(E1)_up = 0.61 10^-3 e² fm² . The B(M1, 1+ -> 2+1 )/B(M1, 1+ -> 0gs ) branching ratios in combination with the expected results from the Alaga rules demonstrate that K is a good approximative quantum number for 24Mg. The use of the known (E0, 0+_2 -> 0+_gs) strength and the measured B(M1, 1+ -> 0+_2) / B(M1, 1+ -> 0+_ gs) branching ratio of the 10.712 MeV 1+ level allows, in a two-state mixing model, an extraction of the between the prolate ground-state structure and shape-coexisting superdeformed structure built upon the 6432-keV 0+_2 level.

In a recent Letter [T. Dornheim \textit{et al.}, Phys. Rev. Lett. \textbf{121}, 255001 (2018)], it was predicted on the basis of \textit{ab initio} quantum Monte Carlo simulations that, in a uniform electron gas, the peak $\omega_0$ of the dynamic structure factor $S(q,\omega)$ exhibits an unusual non-monotonic wave number dependence, where $d\omega_0/dq < 0$, at intermediate $q$, under strong coupling conditions. This effect was subsequently explained by the pair alignment of electrons [T. Dornheim \textit{et al.}, Comm. Phys. \textbf{5}, 304 (2022)].
Here we predict that this non-monotonic dispersion resembling the roton-type behavior known from superfluids should be observable in a dense, partially ionized hydrogen plasma. Based on a combination of path integral Monte Carlo simulations and linear response results for the density response function, we present the approximate range of densities, temperatures and wave numbers and make predictions for possible experimental observations.

According to German requirements for LOCA analyses, it has to be proven in addition to the common safety criteria that less than 10% of the fuel rods rupture during the accident. In order to perform such core damage extent analysis, a newly developed model of a generic German Pressurized Water Reactor is presented. The model developed with the system code ATHLET-CD includes four loops and a detailed configuration of the reactor pressure vessel. A 3D parallel channel approach is applied for the downcomer, lower and upper plenum and the core, which is modelled by 193 thermal-hydraulic channels (one channel per fuel assembly) and multiple rods per channel in order to represent the power distribution in a sufficiently accurate way. New for such detailed system code analyses is that the deformation and burst of the fuel rods and the feedback to thermal hydraulics by reduction of the flow cross-sections is taken into account. The number of failed rods has been determined for best-estimate and top-peaked power profiles and has been compared to the 10% criterion. Furthermore, the large-break LOCA leads to asymmetric thermal-hydraulic boundary conditions at the RPV inlets and outlets because of break of only 1 out of 4 loops, asymmetric emergency core-cooling due to postulated outage and/or malfunction of certain trains and the influ-ence of the pressurizer. In contrast to previous studies, an asymmetric distribution of the failed rods within the core is observed, depending on the location of break, pressurizer and available ECCS injection.

Strontium-90 (90Sr) is an anthropogenic radionuclide, which, due to its radiological relevance, has been most intensively monitored in the past. In terms of initial activity, over 630 PBb of this radioisotope have been distributed globally from stratospheric fallout of bomb-testing, and there are more localized contributions from test, accidents, and releases from reprocessing plants. In the past massive sample sizes (up to 100 l of seawater or 100 g of coral aragonite) were required even right after the peak period of global fall-out from bomb testing. On the other hand, the high amount of strontium dissolved in seawater complicates the use of mass spectrometric methods, as an isotopic abundance sensitivity of at least 1·10-15 is required to detect the estimated main signal. With recent advances in isobar separation technique in accelerator mass spectrometry (AMS) at the University of Vienna, this requirement has come within reach, offering new research possibilities. The new technique uses an ion-cooler and laser-photo-detachment to suppress the stable isobar 90Zr almost completely. With initial test samples we could confirm an isotopic abundance sensitivity of 8·10-16 90Sr/Sr, sufficient for application to ocean water samples. In this presentation we will show comparison of 90Sr to 236U, another ocean tracer that has been studied intensively recently. We will present results from contemporary coral skeleton material, the methods, requirements, and impact of sample preparation. Further, first result from ocean water samples and the sample preparation and blank levels for these types of samples will be shown. Finally, we explain our sample preparation scheme to extract 236U, simultaneously with 90Sr for multi-isotope applications of both.

Uptake of uranium (U) by secondary minerals, such as carbonates and iron (Fe)-sulfides, that
occur ubiquitously on Earth, may be substantial in deep anoxic environments compared to
surficial settings due to different environment-specific conditions. Yet, knowledge of U
reductive removal pathways and related fractionation between 238 U and 235 U isotopes in
deep anoxic groundwater systems remain elusive. Here we show bacteria-driven degradation
of organic constituents that influences formation of sulfidic species facilitating reduction of
geochemically mobile U(VI) with subsequent trapping of U(IV) by calcite and Fe-sulfides.
The isotopic signatures recorded for U and Ca in fracture water and calcite samples provide
additional insights on U(VI) reduction behaviour and calcite growth rate. The removal effi-
ciency of U from groundwater reaching 75% in borehole sections in fractured granite, and
selective U accumulation in secondary minerals in exceedingly U-deficient groundwater
shows the potential of these widespread mineralogical sinks for U in deep anoxic
environments.

The coexistence of the charge-density wave (CDW) and the superconducting phase and their tunability under external pressure remains one of the key focus points in understanding the electronic structure of AV3Sb5 (A = K, Rb, Cs) kagome metals. Here, we employ synchrotron-based infrared spectroscopy assisted by density-functional calculations to study the pressure evolution of the electronic structure at room temperature up to 17 GPa experimentally for the first time. The optical spectrum of CsV₃Sb₅ is characterized by the presence of localized carriers seen as a broad peak at finite frequencies in addition to the conventional metallic Drude response. The pressure dependence of this low-energy peak mirrors the re-entrant behavior of superconductivity and may be interpreted in terms of electron-phonon coupling changing with the growth and shrinkage of the Fermi surface (FS). Moreover, drastic modifications in the low-energy interband absorptions are observed upon the suppression of CDW. These changes are related to the upward shift of the Sb2 px +py band that eliminates part of the FS around the M-point, whereas band saddle points do not change significantly. These observations
shed new light on the mixed electronic and lattice origin of the CDW in CsV₃Sb₅.

Progress in computing technologies enforces an active search for novel materials, assuring low-power and high-speed operations. One of prospective materials for such needs is Cr2O3. Here, we discuss access to the order parameters and properties of antiferromagnetic domain walls related to the possibility of electric operations on them, as well as fundamental and technological perspectives of the recently accessed flexomagnetism in thin Cr2O3 films.

Antiferromagnets, which possess nearly zero magnetic moment and consist of a few magnetic sublattices connected by the symmetry operation of their permutation, represent a perspective material platform for technology and fundamental science. Among a variety of such materials, \ch{Cr2O3} is a unique example of the easy axis magnetoelectric material at room temperature. Here, we discuss measuring and manipulation of domain walls in single crystal and polycrystalline \ch{Cr2O3} samples, and respective applications including electric access to the texture state: pinning at grain boundaries, elastic degrees of freedom of a domain wall and detection of an uncompensated magnetization, which originates from the spatial distribution of the \neel{} temperature and is coupled with the strain gradient.

Interplay between the geometry and behavior of magnetic textures in statics and dynamics has been traditionally considered regarding planar confined samples and their boundaries (vortices in nanodisks, interaction of skyrmions and domain walls with notches etc.). Recent developments of experimental techniques on fabrication of freestanding 3D nanostructures gave a possibility to access and validate theoretical predictions of behavior of magnetic textures, related to the intrinsic geometric properties of extended films and complex sample topologies [1].

Properties of energy functionals in both, ferro- and antiferromagnetic samples reflect geometric symmetries in curvature-driven Dzyaloshinskii-Moriya interaction and anisotropies, which are proportional to the first and second powers of the curvatures, respectively [1]. Magnetostatics is also sensitive to the breaks of the geometric symmetries. In thin films, it is possible to tease out an interplay between the out-of-surface magnetization component and mean curvature of the film [2]. Furthermore, for such non-local textures as vortices hosted by asymmetric Py caps, it enables complex magnetochiral effects pronounced in twisting of the vortex string in a helix and coupling of this helix chirality with the vorticity of the whole texture [3].

Antiferromagnetic curvilinear nanoarchitectures provide more intrinsic material symmetries. In spin chains, the dipolar interaction provides the hard-axis shape anisotropy, with the anisotropy axis along the tangential direction to the chain. This makes the geometry-driven helimagnetic phase transition to be possible for any finite curvature and torsion of the chain [4]. The locally broken spatial translation symmetry of antiferromagnetic dimers in bipartite chains leads to the micromagnetic energy term of the non-chiral longitudinal Dzyaloshinskii energy symmetry and enables local weak ferromagnetic response related to the spatial inhomogeneity of the Neel vector [5]. The geometry-driven easy axis of anisotropy is present even if the material anisotropy is of the hard-axis type, which enables spin-flop transition governed by the chain shape. In a particular case of the ring with the hard-tangential anisotropy and uniform ground state, the helimagnetic phase transition appears in spin-flop phase and the intermediate canted phase for the case of strong Dzyaloshinskii-Moriya interaction [6].

References
1. D. Makarov, O. Volkov, A. Kakay et al., Adv. Mat. 34, 2101758 (2022)
2. D. Sheka, O. Pylypovskyi, P. Landeros et al., Commun. Phys. 3, 128 (2020)
3. O. Volkov, D. Wolf, O. Pylypovskyi, et al., Nat. Commun. In press (2023)
2. O. Pylypovskyi, D. Kononenko, K. Yershov et al., Nano Lett. 20, 8157 (2020)
5. O. Pylypovskyi, Y. Borysenko, J. Fassbender et al., Appl. Phys. Lett. 118, 182405 (2021)
6. Y. Borysenko, D. Sheka, J. Fassbender, et al., Phys. Rev. B 106, 174426 (2022)

Curvilinear spin chains are simplest antiferromagnetic systems revealing direct influence of their shape onto magnetic states via geometry-tracking anisotropies stemming from the dipolar interaction [1] or local surrounding [2]. Here, we show that in addition to the strongest effect onto magnetic state from exchange (biaxial anisotropy and chiral energy term) [1], the local break of the translational symmetry in curvilinear anisotropic antiferromagnets leads to (i) the longitudinal Dzyaloshinskii-Moriya energy term stemming from the single-ion anisotropy and (ii) the local weakly ferromagnetic response [2]. Furthermore, non-zero curvature κ can drive the helimagnetic phase transition in the spin-flop phase and enables the intermediate canted state for rings with large enough κ. [1] O. Pylypovskyi, D. Kononenko et al., Nano Lett. 20, 8157 (2020); [2] O. Pylypovskyi et al., Appl. Phys. Lett. 118, 182405 (2021); [3] Y. Borysenko et al., Phys. Rev. B, 106, 174426 (2022).

Understanding behavior of magnetic texture in antiferromagnetic nanostructures and thin films is crucial for the design of novel magnetic data storage and logic devices. Here, we derive the boundary conditions for the Néel vector in a two-sublattice antiferromagnet (AFM) and apply them to describe the shape of the domain walls [1,2] and skyrmions [2] in confined samples. In general, the surface of a 3D domain wall behaves as an elastic ribbon which bends in response on the topographic features of the single crystal Cr2 O3 [1]. In presence of the Dzyaloshinskii-Moriya interaction, topologically non-trivial AFM textures possess broadening near the surface. In thin films, the sample’s granularity becomes crucial. We present a model of a granular AFM and, by comparison with Nitrogen Vacancy magnetometry of 200-nm-thick Cr2O3 films, estimate the inter-grain exchange strength. The grain boundaries act as strong pinning sites for the AFM texture. [1] N. Hedrich et al., Nat. Phys. 17, 574 (2021); [2] O. Pylypovskyi et al., Phys. Rev. B 103, 134413 (2021).

Underground accelerator laboratories are important instruments to measure nuclear reactions with low cross sections in experimental nu- clear astrophysics. The reduced detector background due the shielding from cosmic rays allows the study of astronuclear reactions at energies relevant to Big Bang nucleosynthesis and stellar burning. The reac- tions 3He(a,g)7Be and 12C(p,g)13N have recently been studied at the shallow underground laboratory Felsenkeller Dresden, where a 5 MV accelerator provides several high intensity ion beams and an ultra-low background counting setup for activation measurements. In the talk, the latest scientific results from the Felsenkeller laboratory, its current capabilities and upcoming enhancements will be summarized.

The 12C(p,γ)13N reaction is the onset process of both the CNO and Hot CNO cycles that drive massive star, Red and Asymptotic Giant Branch star and novae nucleosynthesis. The 12C(p,γ)13N rate affects the final abundances of the stable 12,13C nuclides, with ramifications for meteoritic carbon isotopic abundances and the s-process neutron source strength. Here, a new underground measurement of the 12C(p,γ)13N cross-section is reported. The present data, obtained at the Felsenkeller shallow-underground laboratory in Dresden (Germany), encompass the 320-620 keV center of mass energy range to include the wide and poorly constrained E = 422 keV resonance that dominates the rate at high temperatures. This work S-factor results, lower than literature by 25%, are included in a new comprehensive R-matrix fit, and the energy of the 1 + first excited state of 13N is found to be 2369.6(4) keV, with radiative and proton width of 0.49(3) eV and 34.9(2) keV respectively. A new reaction rate, based on present R-matrix fit and extrapolation, is suggested.

Various continuous-wave (CW) electron gun technologies are reviewed, including DC, superconducting radio frequency RF (SRF), hybrid DC-SRF and normalconducting RF. Also, the SLAC Linac Coherent Light Source II (LCLS-II) normal-conducting RF gun and injector are described, and the performance to date, including the bunch emittance achieved and the dark current observed, is presented.

The 12C/13C ratio is a significant indicator of nucleosynthesis and mixing processes during hy- drogen burning in stars. Its value mainly depends on the relative rates of the 12C(p,γ)13N and 13C(p,γ)14N reactions. Both reactions have been studied at the Laboratory for Underground Nu- clear Astrophysics (LUNA) in Italy down to the lowest energies to date (Ec. m. = 60 keV) reaching for the first time the high energy tail of hydrogen burning in the shell of giant stars. Our cross sections, obtained with both prompt γ-ray detection and activation measurements, are the most precise to date with overall systematic uncertainties of 7–8%. Compared with most of the liter- ature, our results are systematically lower, by 25 % for the 12C(p, γ)13N reaction and by 30 % for 13C(p, γ)14N. We provide the most precise value up to now of 3.6 ± 0.4 in the 20 – 120 MK range for the lowest possible 12C/13C ratio that can be produced during H burning in giant stars.

The Felsenkeller underground laboratory for nuclear astrophysics includes a 5 MV Pelletron ion accelerator and Germany’s lowest background high-purity germanium detector setup for radioactivity measurements. The lab is jointly operated by HZDR and TU Dresden. Protected by its 45 m thick rock overburden, the Felsenkeller cosmic-ray muon flux is 40 times lower than at surface. The natural neutron background is 180 times lower, and the background in a gamma-ray detector with muon veto more than 1000 times lower than at surface. These characteristics place the laboratory in a league with deep underground accelerator labs worldwide and enable highly sensitive nuclear reaction experiments.

The scientific program specifically addresses solar fusion, cosmology, and nucleosynthesis in neutron star precursors. The talk will new reaction data addressing deuterium and lithium from the Big Bang, and solar hydrogen burning.These science cases are highly topical and closely linked to efforts at GSI and FAIR.

In addition to in-house research by HZDR and TU Dresden, the lab is open as a facility for scientific users worldwide, with beam time applications reviewed by an independent science advisory board based on the scientific merits. In addition, EU-supported transnational access is available via the ChETEC-INFRA network of small and medium-scale European research infrastructures for nuclear astrophysics.

The two-fluid model is usually combined with closure forces designed for applications on coarse grids, i.e. bubbles (or particles) are typically assumed to be smaller than a grid cell. Practical applications however include situations where the mesh is comparatively fine, e.g. when meshing the wall boundary layer or in cases with growing bubbles. This may lead to non-convergent behaviour in mesh studies or to void fraction oscillations. To tackle this problem, a filtering approach is proposed, based on an additional diffusion term in the continuity equation. This approach increases the robustness of the results in regions of high spatial resolution, significantly reducing mesh-dependency of the simulation results. The implementation is straightforward, without a need to solve any additional system of equations. It is analysed in four different bubbly flow cases with varying characteristics: 2D/3D, wedge, square, and cuboid computational domains, with resolutions up to 32 cells per bubble diameter, laminar and turbulent flows, and several ways of gas injection. The additional computational effort varies, but is moderate. The proposed approach is applicable in multi-field two-fluid models for which a stable Euler-Euler behaviour on fine meshes is required, for example to prepare the transfer to an interface-resolving volume-of-fluid representation in morphology-adaptive approaches.

Abstract
The understanding of the interaction of radionuclides (RNs) with plant cells serves as basis to explore their transfer in the environment and their uptake into the food chain. Europium(III) is used as an analog for the hazardous actinides Am(III) and Cm(III). Our study describes the interaction of Eu(III) with tobacco (Nicotiana tabacum) BY-2 cells on the cellular and molecular level. Cellular level experiments included the determination of the cell viability, the cell growth, and the homeostasis of macro- and microelements in the presence of Eu(III) as well as its bioassociation by the plant cells. Whereas molecular level investigations are focused on the Eu(III) speciation in media and cells applying different complementary luminescence spectroscopic techniques (UV-excitation and direct excitation). Different Eu(III) species could be distinguished in the media after separating the cells and on the BY-2 cells. The characteristic sum spectrum of the cell-bound Eu(III) depicts a very strong intensity of the hypersensitive 5D0  7F2 transition. The cellular and molecular level investigations with BY-2 cells will be compared with results obtained with Daucus carota [1] and Brassica napus cells [2]. The spectroscopic results indicated differences in the Eu(III) speciation on BY-2 cells on one side compared with D. carota and B. napus cells on the other side.

References
[1] J. Jessat; et al. A comprehensive study on the interaction of Eu(III) and U(VI) with plant cells (Daucus carota) in suspension. J. Hazard. Mater. 439; 2023; 129520.
[2] J. Jessat; et al. Bioassociation of U(VI) and Eu(III) by plant (Brassica napus) suspension cell cultures – A spectroscopic investigation. Environ. Sci. Technol. 55; 2021; 6718 – 6728.

Data, code, and metadata that can be used to reproduce the analyses underlying 'Environmental drivers of body size in North American bats' by Alston et al. 2023 Functional Ecology (Preprint: https://doi.org/10.1101/2021.07.28.454183).

Individual data owners are detailed in the data. Data may only be used to reproduce the analyses underlying Alston et al. (2023). Any other use requires the written permission of the individual data owners.

For more detailed information, please visit the metadata file.

1. Bergmann's rule—which posits that larger animals live in colder areas—is thought to influence variation in body size within species across space and time, but evidence for this claim is mixed.

2. We used Bayesian hierarchical models to test four competing hypotheses for spatiotemporal variation in body size within 20 bat species across North America: (1) the heat conservation hypothesis, which posits that increased body size facilitates body heat conservation (and which is the traditional explanation for the mechanism underlying Bergmann's rule); (2) the heat mortality hypothesis, which posits that increased body size increases susceptibility to acute heat stress; (3) the resource availability hypothesis, which posits that increased body size is enabled in areas with more abundant food; and (4) the starvation resistance hypothesis, which posits that increased body size reduces susceptibility to starvation during acute food shortages.

3. Spatial variation in body mass was most consistently (and negatively) correlated with mean annual temperature, supporting the heat conservation hypothesis. Across time, variation in body mass was most consistently (and positively) correlated with net primary productivity, supporting the resource availability hypothesis.

4. Climate change could influence body size in animals through both changes in mean annual temperature and resource availability. Rapid reductions in body size associated with increasing temperatures have occurred in short-lived, fecund species, but such reductions will be obscured by changes in resource availability in longer-lived, less fecund species.

muss noch eingetragen werden.

Imaging techniques such as positron emission tomography need radionuclides that can be produced with cyclotrons. The involved nuclear reactions mostly produce neutron and gamma radiation, which must be shielded. In order to be able to determine the required thickness of the shielding for a new medical cyclotron, corresponding radiation protection calculations were carried out. The necessary neutron source term was supplied by the manufacturer. To verify this source term, additional source terms were calculated with the MCNP6 and the FLUKA code packages. The results with the source, on base of code internal nuclear models, produced comparable results, but the neutron yield with the source supplied by the manufacturer is lower by a factor of about 5. To validate the results, experiments were carried out on an already existing cyclotron. Neutron fluence was measured with standard monitors which are used in reactor dosimetry. The experiment was performed during regular 18F production. The activities of the nuclides were measured by gamma spectroscopy and compared with the calculated activities. We found varied agreements between calculated results with the internal source and experimental results.

Beim Rückbau eines Kernkraftwerkes ist die genaue Kenntnis über die spezifischen Aktivitäten des Reaktordruckbehälters (RDB) und deren Einbauten für eine optimale Planung der Entsorgung dieser Großkomponenten und damit die Minimierung der anfallenden radioaktiven Abfälle unabdingbar. Diese kann auf Basis von Rechnungen vor dem beginnenden Rückbau gewonnen werden. Eine wesentliche Voraussetzung für die exakte Bestimmung der Aktivitäten ist dabei eine sehr gute Berechnung der akkumulierten Neutronenfluenzen in den Komponenten, denn die beim Betreiben des Kraftwerks entstehenden Radionuklide werden primär durch die dort herrschende Neutronenstrahlung verursacht. Damit ist eine frühzeitige radiologische Charakterisierung der Komponenten möglich, ohne Proben zur Analyse entnehmen zu müssen.
In diesem Zusammenhang wurde eine Methode entwickelt, die auf dem kombinierten Einsatz von zwei Monte-Carlo-Codes basiert (MCNP6 [1] und FLUKA2021 [2]) und die Bewertung der Aktivierung in den kernnahen Komponenten in einem frühen Stadium der Planung, d.h. noch während des Betriebs, ermöglicht. Die Methode ist anhand eines deutschen Druckwasserreaktors (DWR) verifiziert worden.
Der MCNP6 Code wurde verwendet, um die Neutronenfluenzen im RDB und dessen Einbauten zu berechnen. Dafür wurde ein sehr detailliertes 3D-Modell eines DWR entwickelt, das auch die biologische Abschirmung und das Trageschild miteinschließt. In dieses Modell sind alle zur Verfügung stehenden Informationen eingeflossen. Die verwendete Neutronenquelle basiert auf Abbrandberechnungen des Betreibers und wurde brennstabweise modelliert. Um die Zuverlässigkeit der Ergebnisse zu überprüfen, wurde das MCNP6-Modell und die benutzte Neutronenquelle auf Basis von Neutronenfluenzmessungen validiert. In zwei deutschen DWR wurden entsprechende Monitore installiert, während eines Zyklus bestrahlt und anschließend deren Aktivierung gammaspektrometrisch bestimmt. Die Vergleiche zwischen den berechneten und gemessenen Aktivitäten haben gezeigt, dass die MCNP6-Berechnungen die realen Bedingungen im Reaktor widerspiegeln und für die folgenden Aktivierungsberechnungen verwendet werden können.
Für die anschließenden Aktivierungsberechnungen wurde der FLUKA2021-Code verwendet. Die Grundlage der 3D-Modelle bildete das MCNP Modell. Dabei wurden Teilabschnitte von Komponenten moduliert und für diese, auf Basis der berechneten Neutronenfluenzspektren, entsprechende Oberflächenquellen generiert. Mit diesem Verfahren konnten die spezifischen Aktivitäten in den einzelnen Komponenten sowohl in einem feinen Netz als auch mit großer Genauigkeit berechnet werden. Sie können als Grundlage für die Charakterisierung der Reaktorkomponenten verwendet werden, das wiederum als Basis einer optimalen Planung der verschiedenen Entsorgungswege und deren Lagerung dient.
Diese Arbeit wird im Rahmen des Forschungsprogramms FORKA (Forschung für den Rückbau kerntechnischer Anlagen) vom Bundesministerium für Forschung und Bildung (BMBF, Förderkennzeichen 15S9409A) gefördert und zusätzlich von PreussenElektra unterstützt.

Vor der Inbetriebnahme von Anlagen, die ionisierte Strahlung emittieren, müssen Untersuchungen zum entstehenden Strahlenfeld und deren Abschirmung durchgeführt werden. 2018 wurde am Helmholtz-Zentrum Dresden-Rossendorf ein neuer Kreisbeschleuniger (Zyklotron) zur Herstellung von Radioisotopen für medizinische Anwendungen installiert, und im Vorfeld wurden entsprechende Rechnungen zum Strahlenfeld durchgeführt.
Auf der Grundlage einer vom Hersteller vorgegebenen Neutronenquelle [1], die allgemein für Strahlenschutzrechnungen beim Zyklotron genutzt wird, wurden Neutronen- und Gammadosisleistungen innerhalb und außerhalb des Gebäudes mit dem Monte-Carlo-Code MCNP6 [2] geschätzt. Parallel dazu wurden Rechnungen durchgeführt, mit denen der Quellterm auf Basis des „Cascade Exciton Model“ (CEM) bestimmt wurde. Dieses Kernmodell ist bereits im MCNP implementiert, so dass hier direkt der Protonenstrahl als Primärquelle genutzt werden konnte. Überraschend war, dass die vom Hersteller gelieferte Quelle eine um den Faktor 5 geringere Ausbeute aufwies. Dagegen ergaben Nachrechnungen mit dem FLUKA-Code [3], der ein anderes Kernmodell verwendet (Pre-Equilibrium Cascade Model, PEANUT), vergleichbare Ergebnisse zu den Rechnungen mit der CEM Quelle. Der Unterschied wird auf die fehlenden Kanäle in der vom Hersteller gelieferten Neutronenquelle zurückgeführt, die nur die 18O(p,n)18F-Reaktion berücksichtigt, während die MCNP- und FLUKA-Berechnungen zusätzliche Neutronenreaktionskanäle einschließen.
Um die Neutronenquelle zu validieren, wurde ein experimentelles Programm gestartet, bei dem Aktivierungsproben während eines 18F-Produktionslaufs in der Nähe eines H218O-Targets platziert wurden. Nach der Bestrahlung wurde die Aktivierung der Proben gammaspektrometrisch mit Hilfe eines HPGe Spektrometers (High-Purity Germanium Detector) bestimmt und anschließend die Aktivität mit entspre¬chenden Rechenergebnissen verglichen. Die Ergebnisse der Simulationen und der Experimente stimmten gut überein, die C/E (Calculation/Experiment) Verhältnisse lagen größtenteils zwischen 0,6 und 1,4.
Die Ergebnisse der MCNP-Berechnungen für das neue Rossendorfer Zyklotron zeigen, dass bei der maximalen Protonenenergie von 28 MeV eine Gesamtortsdosisleistung im Bereich des öffentlichen Verkehrs von ca. 0,1 µSv/h zu erwarten ist und damit deutlich unter dem Richtwert für das Betriebsgelände von 0,5 µSv/h liegt [4]. Hauptursache der Dosis sind Photonen, die aus den Neutroneneinfang innerhalb der Betonwände emittiert werden. Sie verursachen dabei 98 % der Gesamtdosis. Die Dosisleistung der vom Wassertarget stammenden Photonenstrahlung wurde auf etwa 0,01 µSv/h und die von den Neutronen auf etwa 0.002 µSv/h geschätzt.

The MCPA herbicide mobilizes trace metals in soil by outcompeting adsorption by soil minerals[1]. Trace metal tracers are too immobile for the relatively short observation times available with positron emission tomography (PET). For the first time, however, timelapse movies of Cu migration in columns filled with artificial soil (68 % sand, 26 % silt, 5 % illite clay, 1 % goethite) were recorded. Soil solution was supplied from bottom up at a flow rate of 100 µL/min, low enough to allow for equilibration while maintaining a residence time in the order of tracer half-life (12.7 h). Up to 5 mL or 250 MBq of Cu-64 tracer was applied in one pulse run. The figure show volume renderings at different times (voxel size = 1 mm³, column high = 10 cm). The radiolabeled Cu-MCPA complex breakthrough occurred just about 10-fold slower than the inert solute tracer [F-18]KF used in control columns shown in the lower row of the figure. Imaging movies are accessible at [2].
1. Kulenkampff J. et al. (2018). Sci. Rep., 8(7091). Open access CC BY 4.0.
2. URL https://zenodo.org/record/852968

Electrochemical oxygen reduction reaction (ORR) is fundamental for many energy conversion and storage devices. Selective tuning of *OOH/*OH adsorption energy to break the intrinsic scaling limitation (ΔG*OOH = ΔG*OH + 3.2 eV) is effective in optimizing the ORR limiting potential (UL), which however, is practically challengeable to be achieved by constructing a particular catalyst. Herein, using first-principles calculations, we elucidated how to rationally plant an additional *OH that can selectively interact with the ORR intermediate of *OOH via hydrogen bonding, while not affecting the *OH intermediate. Guided by the design principle, we successfully tailored a series of novel carbon-based catalysts, with merits of low-cost, long-lasting, synthesis feasibility, exhibiting a high UL (1.06 V). Our proposed strategy comes up with a new linear scaling relationship of ΔG*OOH = ΔG*OH + 2.84 eV. This approach offers a great possibility for the rational design of efficient catalysts for ORR and other chemical reactions.

Purpose/Objective:

Biomedical images are a source of high-dimensional information that can be extracted using feature-based machine learning (radiomics). Moreover, preclinical radiotherapy research using animal models generates an enormous number of images that are generally overlooked as a source of quantitative image-based biomarkers. Here we apply radiomics feature extraction methods to 2D histopathology data from a published animal trial (Rassamegevanon et al., Radiother. Oncol., 2019) to classify HNSCC tumors based on their known radiosensitivity.
 
Materials/Methods:
Athymic mice were xenotransplanted with three HNSCC tumor models of varying radiosensitivity. The tumors were irradiated in vivo with 2 – 8 Gy, excised 24 hours post-treatment, and stained for nuclear marker DAPI. Up to 13 ROIs per tumor were imaged using fluorescence microscopy and the nuclei were segmented using ImageJ plugin StarDist. Standardized radiomic features were extracted and clustered using the radiomics processor MIRP. Then, the feature set was processed via 33 repetitions of 3-fold cross-validation (CV) of the training cohort with the machine learning framework FAMILIAR, using the MIFS algorithm for feature selection. A final radiomics signature was derived based on the power to classify resistant and sensitive tumors, using cumulative scoring across the CV folds and hyperparameter optimisation. A logistic regression model was trained to predict tumor radiosensitivity using the final signature. Its performance was validated on an independent data set.

Results:

Twenty-four tumors from one radioresistant model (SAS) and 24 tumors in total from two radiosensitive models (SKX and XF354) were used for the initial analysis. More than 250 ROIs per sensitivity class were considered and assigned to the training (2/3) and validation (1/3) cohorts. ROIs originating from the same tumor were treated as independent samples. 223 radiomic features were extracted from each ROI and the three best performing features for the classification of tumors as radioresistant or radiosensitive were identified (one morphological and two texture-based features). The logistic regression model using the final signature yielded a high accuracy: 0.96 (95% CI 0.94 – 0.98) and 0.93 (95% CI 0.89 – 0.97) for the training and validation cohort, respectively. Implementation of additional pre-processing and quality control steps such as stability analysis and batch effect control will be presented.

Conclusion:

Quantitative image features can be extracted from 2D preclinical immunofluorescence data with a potential to classify tumors based on their radiosensitivity. However, further modifications are required to increase the robustness of the classification signature. Radiomics analysis of preclinical image data can serve as a basis for biological hypotheses and design of preclinical validation experiments, and support the interpretability of clinically relevant radiomics models.

Rhamnolipids have received great attention in various environmental applications in terms of metal complexation and recovery. However, the influence of metal ions on the interfacial, foaming, and ion flotation properties of rhamnolipid are poorly investigated. In this study we investigated the effect of metal ions alone and in a mixed metal system on the interfacial and foaming properties of rhamnolipid. Further, the potential of rhamnolipid to recover and separate Gallium from a mixed metal system containing Gallium (Ga) and Arsenic (As) using bioionflotation has been investigated. The effect of operating parameters like pH, rhamnolipid concentration, and airflow rate were tested and found to have a significant influence on the separation performance. The maximum removal of Ga could reach 74 % when rhamnolipid concentration was 0.85 mM at pH 6 and an airflow rate of 80 ml/min. The selectivity index of Ga over As was highest (17.2) at 0.85 mM rhamnolipid concentration, pH 6, and an airflow rate of 40 ml/min. Also, the selective separation of Ga was dependent on the recovery of water from the foam. The results showed that rhamnolipid biosurfactant acted as a highly efficient ion collector for Ga and the optimized process parameters could be expected to provide very efficient separation and recovery of target metal via ion flotation.

The current study investigated the application of rhamnolipid biosurfactant as an ion collector in bioionflotation. In a top-down approach, the influence of rhamnolipid on gallium (Ga) ion flotation and recovery were investigated followed by detailed studies on the influencing parameters and foam characterization. Rhamnolipid exhibits extensive foaming properties and foam produced by rhamnolipid alone has higher stability making it difficult to collect the flotation concentrates. An addition of 1,2-decanediol introduces instability to this foam and also aids in concentrate collection. Observations during the flotation studies resulted in a series of investigations on rhamnolipid properties such as aggregate size, surface tension, and foam characterization. These results indicated that the addition of Ga and/or 1,2-decanediol affected the molecular aggregation of rhamnolipid. Moreover, the surface activity, foamability, foam drainage, and foam coarsening/coalescence of the rhamnolipid changed in the presence of Ga and/or 1,2-decanediol. In a batch bioionflotation process, rhamnolipid was able to remove nearly 80% Ga at pH 7 in presence of 1,2-decanediol. However, upgrading was higher at pH 6 without 1,2-decanediol, which is important when considering the flotation recovery in presence of other metals. Such biosurfactants have a high potential for wide applications in ion flotation and further optimization of flotation parameters is essential.

The sample preparation and evaluation of the effects of impurities on the determination of ¹ ⁰Be and ² ⁶Al by accelerator mass spectrometry (AMS) was performed as an initial part of research project determining the timing of early hominin occupation at Korolevo, western Ukraine. The rock samples analysed exhibited various levels of weathering, lithology, and mass. The follow-up mass spectrometry scans revealed Ti impurity in BeO targets which stimulated quantification of Ti in quartz concentrate. The ² ⁶Al to ¹ ⁰Be ratios were independent on Ti and Al impurity for samples from the same depositional
level. AMS Be current reduction was a function of BeO dilution by TiO₂ molecules.

Nuclear astrophysics seeks to understand the nuclear processes that govern galactic chemical evolution, with the help of experiments conducted on Earth. Precise knowledge of the nuclear reaction cross sections is crucial for understanding the role of the reactions at play, but the measurement of these small cross sections often poses great experimental challenges.

Underground accelerator laboratories utilize the natural shielding of a rock overburden to reduce background from cosmic rays, and provide a rather unique environment to study nuclear reactions with high sensitivity. In recent years, several new underground accelerators have taken up operation for nuclear astrophysics studies, extending the range of available beam intensities, ion species, and beam energies underground.

This seminar will introduce the advantages and challenges of going underground for measurements of radiative capture reactions, present an overview of the current landscape of underground accelerator facilities, and highlight recent results obtained in these laboratories.

Aim: Cannabinoid receptor 2 (CB2) expression in healthy brain is very low and the upregulation is associated with inflammation, traumatic brain injury, neurodegeneration and cancer[1]. In view of the increasing interest in CB2-targeted therapies, PET offers an attractive strategy to quantify the availability of CB2 in the diseased brain. To achieve this goal, we developed a number of 18F-labelled CB2 ligands and biologically evaluated them in rodents. Here we present a comparative overview of the obtained results.
Methods: Structure-activity-relationships-driven target compound identification, organic synthesis and radiofluorination was performed for compounds of the thiazole ([¹⁸F]JHU94620[2] and [¹⁸F]LUZ5[3]), naphthyridin-2-one ([¹⁸F]LU14[4] and [¹⁸F]LU13[5]) and indole ([¹⁸F]RM365) families. The new radioligands were assessed in vitro by binding experiments using CHO(hCB2) cells and rat spleen homogenates and by autoradiography on cryosections of rodent spleen. Furthermore, the radioligands were examined for their metabolic stability and biodistribution by PET. Furthermore, for selected radioligands the binding to highly expressed hCB2 in a rat model overexpressing hCB2(D80N) in the right striatum (AAV-hCB2)[6] was investigated.
Results: The low- to subnanomolar hCB2 affinities of the presented radioligands were demonstrated in vitro by Kd values ranging from 0.4 to 2.9 nM with a hCB2 selectivity against hCB1 of >1000-fold. The highest metabolic stability was observed for [18F]RM365 with 55% and 90% and the lowest for [¹⁸F]JHU94620 with 7% and 36% of the initial fraction in plasma and brain 30 min p.i., respectively. The in vivo experiments confirmed the in vitro autoradiographic results, and showed high uptake for [¹⁸F]JHU94620, but low or non-displaceable uptake for [¹⁸F]LU14, [¹⁸F]LUZ5 and [¹⁸F]RM365 in spleen. Contrary to the low uptake of [¹⁸F]LUZ5 in the brain of naïve Wistar rats, target-specific and displaceable uptake for [¹⁸F]LU14 and [¹⁸F]RM365 was demonstrated in the AAV-hCB2 rat model, with the highest signal-to-noise ratio determined for [¹⁸F]RM365 expressed as SUVR of 20 and lowest for [¹⁸F]LU14 expressed as SUVR of 6.
Conclusion: A novel series of CB2 receptor radioligands has been developed and preliminarily evaluated in rodents. Binding affinity to the CB2 varies between species, however PET scans with an AAV-hCB2 rat model revealed a high brain uptake and target specificity for hCB2 with excellent signal-to-noise ratios and displaceable binding.
References: [1] Stasiulewicz et al. IJMS, 2020, 21, 2778; [2] Moldovan et al. JMC, 2016, 59, 17; [3] Ueberham et al. JMC, 2023; [4] Teodoro et al. IJMS, 2021, 22, 15; [5] Gündel et al., JMC 2022, 65, 13; [6] Attili et al. BJP, 2019, 176, 1481

Background: Gliomas are highly invasive and infiltrative solid tumors that present significant clinical challenges in terms of achieving complete surgical resection. These tumors often harbor mutated isocitrate dehydrogenase enzymes (mIDH), making them attractive theranostic targets. Therefore, accurately assessing mIDH status is essential for effective patient management. Currently, the presence of mIDH1 is determined either by invasive biopsy or indirectly by measuring the mIDH-derived oncometabolite 2-hydroxyglutarate (2-HG) using magnetic resonance spectroscopy (MRS). The availability of mIDH-targeted radioligands would allow for PET neuroimaging to detect the mIDH1 protein directly and non-invasively.

Methods: The study involved obtaining 18F-labeled AG-120 (Ivosidenib), an FDA-approved small molecule inhibitor of mIDH, by Cu-mediated radiofluorination of a corresponding diastereomerically pure stannyl precursor. The researchers studied the internalization of [18F]AG-120 in vitro in U251 human glioblastoma cells stably transfected with IDH1 or IDH1R132H. Brain uptake and metabolism of [18F]AG-120 were investigated in healthy CD-1 mice by dynamic PET-MR imaging and radio-chromatographic analyses of plasma and brain tissue. Dynamic PET-CT imaging studies were performed in nude rats bearing U251-IDH1 or U251-IDH1R132H glioblastoma.

Results: The (S,S)-enantiomer of [18F]AG-120 was successfully prepared, and the procedure was implemented into a remotely-controlled radiosynthesis module. A considerably higher uptake of activity was observed in U251-IDH1R132H cells compared to U251-IDH1 cells (0.422 vs. 0.014% applied activity/μg protein after 120 min incubation). The percentage of non-metabolized [18F]AG-120 in the mouse 30 min post i.v. injection was 85% in plasma and 91% in the brain, respectively. Dynamic PET studies showed limited blood-brain barrier permeation of [18F]AG-120 (SUV < 0.1 within the first 5 min post i.v. injection), which could be significantly increased by inhibiting the p-glycoprotein 1 with cyclosporine A. PET studies with glioblastoma rats indicated slightly higher tumor-to-blood ratios in IDH1R132H-tumors compared to IDH1-tumors (~1.7 vs. ~1.3 at 40–60 min p.i.).

Conclusion: For the first time, pure (S,S)-[18F]AG-120 has been synthesized. In addition, GMP-compliant production is facilitated by the established automated radiosynthesis. Despite limited BBB permeation, [18F]AG-120 shows target-specific internalization in vitro and high metabolic stability in vivo. Furthermore, the slightly higher accumulation of [18F]AG-120 in IDH1R132H-glioblastoma compared to IDH1-glioblastoma in vivo encourages further evaluation of mIDH inhibitors for the noninvasive detection of IDH1R132H in glioma by PET.

Support: European-Regional-Development-Fund ERDF and Sächsische-Aufbaubank SAB (project no. 100364142).

Einleitung
In der Radioonkologie hat sich die Protonentherapie als Alternative zur Photonentherapie etabliert. Die relative biologische Wirksamkeit (RBW) von Protonen wird bislang klinisch als konstant angenommen, hängt jedoch u. a. von der physikalischen Dosis, dem Gewebetyp und dem linearen Energietransfer (LET) ab. Die Vernachlässigung dieser Variabilität kann zu einer relevanten Unterschätzung von therapiebedingten Nebenwirkungen führen. Die Berechnung des LET ist in einigen Bestrahlungsplanungssystemen möglich, steht jedoch in anderen Systemen sowie für retrospektive Daten nicht immer zur Verfügung. Deep-Learning-basierte Ansätze könnten in diesen Fällen helfen den LET, und somit die variable RBW, abzuschätzen. In dieser Arbeit wird das Potenzial von 3D Convolutional Neural Networks (CNN) zur Berechnung des dosisgemittelten LET (LETd) auf Basis der geplanten Dosisverteilung untersucht.

Material & Methoden
An einer Kohorte von 115 an der Universitäts Protonen Therapie Dresden behandelten Patienten mit primärem Hirntumor wurden drei Netzwerkarchitekturen (UNet, UNETR, SegResNet) mittels einer fünffachen Kreuzvalidierung trainiert und verglichen. Das leistungsfähigste Modell wurde an 28 Patienten aus dem Westdeutschen Protonentherapiezentrum Essen validiert. Dabei wurde die mittels Monte-Carlo (MC)-Simulation generierte LETd-Verteilung anhand der geplanten Dosisverteilung vorhergesagt. Die Genauigkeit des Resultats wurde für einzelne Regionen (u. a. Hirn, Hirnstamm, CTV) bewertet. Durch die RBE-gewichtete Dosis wurden therapiebedingte Nebenwirkungen anhand veröffentlichter Modelle abgeschätzt.

Ergebnisse
Das SegResNet zeigte die qualitativ besten Ergebnisse in der Kreuzvalidierung. In der externen Validierung dieses Modells ergaben sich für den mittleren LETd im Hirn, dem Hirnstamm und dem CTV jeweils eine Wurzel der mittleren quadratischen Abweichung (RMSE) von 0,22, 0,33 und 0,25 keV/µm. Der gepaarte Wilcoxon-Vorzeichen-Rang-Test wies für die drei Regionen keine signifikanten Unterschiede zwischen den MC- und CNN-generierten Verteilungen des mittleren LETd auf. Für die Vorhersage der Wahrscheinlichkeit einer Gedächtnisstörung Grad≥2 12 Monate nach Therapie betrug die RMSE zwischen beiden Ansätzen 0,003.

Zusammenfassung
In dieser Studie wurden 3D-CNN entwickelt, die den Protonen-LETd erfolgreich anhand der geplanten Dosisverteilung vorhersagen. Beobachtete Abweichungen im LETd zeigten dabei einen geringen Einfluss auf die klinisch relevantere Vorhersage behandlungsbedingter Nebenwirkungen. Die entwickelten Modelle können einen wichtigen Beitrag für die Untersuchung der variablen RBW von Protonen leisten, insbesondere für retrospektive Patientendaten und für Kliniken ohne die Möglichkeit der MC-basierten LET-Berechnung.

Rotating Packed Beds (RPBs) are increasingly used in academia and industry for separation processes, but a lack of knowledge about fluid dynamics and liquid maldistribution still limits understanding the mass transfer inside. Recently, structured Zickzack packings (ZZ packings) were designed that promise to provide homogeneous liquid distribution throughout the packing volume. In this study, the fluid dynamics of a water-air system in ZZ packings were characterized at atmospheric pressure and 20°C. For decreasing rotational speeds, a strongly increasing wet pressure drop was observed below 500 rpm due to a formation of a liquid wreath in front of the inner packing edge, and flooding of the rotor eye was visually detected at rotational speeds lower than 300 rpm. At rotational speeds greater than the flooding limit, the fluid dynamics of a single ZZ packing were found to be equal to a stacked two-level ZZ packing. In addition, gamma-ray computed tomography (CT) was used to non-invasively study the liquid distribution inside the rotating packing at multiple scanning planes along the packing height for selected operating conditions. The scans revealed that liquid maldistribution occurred at rotational speeds lower than 1200 rpm, while the liquid was perfectly distributed throughout the packing volume at rotational speeds greater than 1200 rpm.

Raw data for the article 'Revisiting power-law distributions in empirical outage data of power systems' (see the manuscript preprint https://arxiv.org/abs/2303.12714 for more details)

Cobalt is a magnetic material that finds extensive use in various applications, ranging from magnetic storage to ultrafast spintronics. Usually, it exists in two phases with different crystal lattices, namely in hexagonal close packed (hcp) or face-centered cubic (fcc) structure. The crystal structure of Co films significantly influences the magnetic and spintronic properties. We report on the thickness dependence of the structural and magnetic properties of sputter-deposited Co on a Pt seed layer. It grows in an hcp lattice at lower thickness. In thicker films it becomes a mixed hcp-fcc phase due to a stacking fault progression along the growth direction. The x-ray-based reciprocal space map technique has been employed to distinguish and confirm the presence of both phases. Moreover, the precise determination of Land ́e’s g-factor by ferromagnetic resonance provides valuable insights into the structural properties. In our detailed experiments, we observed that a structural variation results in a nonmonotonic variation of the magnetic anisotropy along the thickness. The work offers information of great significance in terms of practical application, for both fundamental physics and potential applications of thin films with perpendicular magnetic anisotropy.

We present results of direct maskless magnetic patterning of ferromagnetic nanostructures using a cobalt focused ion beam (FIB) system. The liquid metal ion source of the FIB was made of a Co36Nd64 alloy. A Wien mass filter allows for selecting the ion species. Using the FIB, we implanted narrow tracks of Co ions into a nominal 5000×1000×50 nm3 permalloy strip. We observed the Co-induced changes of the magnetic properties by measuring the sample with microresonator ferromagnetic resonance before and after the implantation. Regions as small as 50 nm can be implanted up to concentrations of at.-10 % near the surface. This allows for easy magnetic modification of edge-localized spin waves with a lateral resolution otherwise hard to reach. The direct-write maskless FIB process is quick and convenient for optical measurement techniques, as it does not involve the virtually impossible removal of ion-hardened resist masks one would face when using lithography with broad-beam ion implantation

Continuous advancements in science and technology in the field of flexible devices encourage researchers to dedicate themselves to seeking candidates for new flexible transparent conductive films (FTCFs). Our recently developed two-dimensional (2D) metal aerogels are considered as a new class of FTCFs. Here, we describe a new large-scale self-assembly synthesis of bimetallic Pt-Ni 2D metal aerogels with controllable morphology during the synthesis. The
obtained 2D aerogels require only a low quantity of precursors for the synthesis of percolating nanoscale networks with areas of up to 6 cm² without the need of an additional drying step. Stacks of the obtained monolayer structures display low sheet resistances (down to 270 Ω/sq), while decreasing the optical transparency. In perspective, the 2D bimetallic Pt-Ni aerogels not only enrich the structural diversity of metal aerogels but also bring forth new materials for further applications in flexible electronics and electrocatalysis with reduced costs of production.

We investigate coherent lattice dynamics in optimally doped YBa2Cu3O7−δ driven by ultrashort (∼ 12 fs) near infrared (NIR) and near ultraviolet (NUV) pulses. Transient reflectivity experiments, performed at room temperature and under moderate (<0.1 mJ/cm2) excitation fluence, reveal phonon modes related to the O(2,3) bending in the CuO2 planes and to the apical O(4) stretching at frequencies between 10 and 15 THz, in addition to the previously reported Ba and Cu(2) vibrations at 3.5 and 4.5 THz. The relative coherent phonon amplitudes are in stark contrast to the relative phonon intensities in the spontaneous Raman scattering spectrum excited at the same wavelength. This contrast indicates mode-dependent contributions of the Raman and non-Raman mechanisms to the generation of the coherent phonons. The particularly intense amplitude of the coherent Cu(2) phonon, together with its initial phase, supports its generation to be dominated by non-Raman mechanism involving charge transfer within the CuO2 plane. By contrast, the coherent out-of-phase O(2,3) bending mode is unproportionally weak compared with its Raman counterpart, suggesting that the charge transfer is ineffective in generating such an "asymmetric" atomic displacement. When the pump light has the polarization component normal to the CuO2 plane, the coherent O(4) mode is strongly enhanced compared to the in-plane excitation, probably by the charge transfer from the apical oxygen to the Cu-O chains. Our findings demonstrate that the charge transfer excitations in YBa2Cu3O7−δ strongly contribute to the electron-phonon coupling on a femtosecond timescale.

MSPaCMAn is the recently developed workflow that does the mineralogical quantification of individual particles using its histograms while considering the effects of partial volume artefacts in interphases at particle level detail. This paper demonstrates and validates the new developments in the MSPaCMAn workflow, aiming to minimize user bias and enhance the accuracy of MSPaCMAn.

Here, in the new developments of MSPaCMAn workflow, firstly, the recently developed deep learning method, namely ParticleSeg3D, is employed to distinguish particles from the background. Secondly, the particle's size and shape information are considered along with its histogram to classify and quantify the mineral phases in liberated particles. After the new developments, the detection limit of MSPaCMAn to characterize small and thin liberated particles is enhanced. Experimental results demonstrate the effectiveness of the MSPaCMAn's updated workflow. It was found that the mineralogical composition calculated by the MSPaCMAn's updated workflow was precise, with the highest coefficient of variance of 6.56%. Moreover, the mineralogical composition determined by MSPaCMAn's updated workflow had low variance across three different reconstruction parameters and two different voxel sizes (5.5 μm and 10 μm). Comparisons with other quantification methods highlight the accuracy of MSPaCMAn's updated workflow to determine the mineralogical compositions. When analyzing a test sample consisting of quartz, calcite, fluorite, and lepidolite, MSPaCMAn's updated workflow achieved the highest mineralogical deviation of only 7.73% from the reference mineralogy. In contrast, the random forest algorithm resulted in a deviation of 51.47%, while the manual thresholding method yielded a deviation of 41.46%.
Overall, these findings emphasize the reliability and accuracy of MSPaCMAn's updated workflow in quantifying mineralogical composition.

For direct cross section measurements in nuclear astrophysics, in addition to suitable ion beams and detectors, also highly pure and stable targets are needed. Here, using a gas jet as a target offers an attractive approach that combines high stability even under significant beam load with excellent purity and high localisation. Such a target is currently under construction at the Felsenkeller underground ion accelerator lab for nuclear astrophysics in Dresden, Germany. The target thickness will be measured by optical interferometry, allowing an in-situ thickness determination including also beam-induced effects. The contribution reports on the status of this new system and outlines possible applications in nuclear astrophysics.

Decentralized electrochemical production of hydrogen peroxide (H₂O₂) is an attractive alternative to the industrial anthraquinone process, the application of which is hindered by the lack of high-performance electrocatalysts in acidic media. Herein, a novel catalyst design strategy is reported to optimize the Pd sites in pure metallic aerogels by tuning their geometric environments and electronic structures. By increasing the Hg content in the Pd-Hg aerogels, the Pd-Pd coordination is gradually diminished, resulting in isolated, single-atom-like Pd motifs in the Pd₂Hg₅ aerogel. Further heterometal doping leads to a series of M-Pd₂Hg₅ aerogels with an unalterable geometric environment, allowing for sole investigation of the electronic effects. Combining theoretical and experimental analyses, a volcano relationship is obtained for the M-Pd₂Hg₅ aerogels, demonstrating an effective tunability of the electronic structure of the Pd active sites. The optimized Au-Pd₂Hg₅ aerogel exhibits an outstanding H₂O₂ selectivity of 92.8% as well as transferred electron numbers of ≈2.1 in the potential range of 0.0-0.4 V_RHE. This work opens a door for designing metallic aerogel electrocatalysts for H₂O₂ production and highlights the importance of electronic effects in tuning electrocatalytic performances.

A significant deceleration effect on a stored coasting ion beam by a continuous-wave laser light was observed in the Schottky-noise spectrum during the laser experiments with lithium-like oxygen ion beams stored at a relativistic energy of 275.7 MeV/u at the heavy-ion storage ring CSRe in Lanzhou, China. The observed deceleration range of the laser (Δp/p≈5.7×10−6) is much broader than the expected capture range (Δp/p≈3.6×10−8), as calculated from the natural linewidth of the O5+ ion’s electronic transition (2S1/2 −2 P1/2). In order to explain this huge deviation, a phase space tracking code has been developed to investigate the interaction between the stored coasting ion beam and the laser light. Simulations reveal that the deceleration range of the typically narrow CW laser force is highly enlarged by taking into account the transverse betatron oscillation of the ions with larger emittance and the angular misalignment of the laser light direction. The experimental observation is well described by the systematic simulations. The present work is crucial for forthcoming laser cooling and precision laser spectroscopy experiments and simulations on heavy highly charged ions at the CSRe and the future facility HIAF.

Hybrid organic–inorganic lead halide perovskites have drawn much interest due to their optical and electronic properties. The ability to fine-tune the structure by the organic component allows for obtaining a wide range of materials with various dimensionalities. Here, we combine experimental and theoretical work to investigate the structures and properties of a series of low-dimensional hybrid organic–inorganic perovskites, based on naphthalene ammonium cations, 2,6-diaminonaphthalene (2,6-DAN), 1-aminonaphthalene (1-AN) and 2-aminonaphthalene (2-AN). All materials exhibit edge- or face-sharing 1D chain structures. Compared to the 2D counterpart containing isomeric 1,5-diaminonaphthalene (1,5-DAN), 1D hybrid materials exhibit broadband light emission arising from the self-trapped excitons (STEs) owing to their highly distorted structure. This work expands the library of low-dimensional hybrid perovskites and opens new possibilities for obtaining broadband-light-emitting materials.

Glioblastoma (GBM) is still an incurable tumor that is associated with high
recurrence rate and poor survival despite the current treatment regimes. With
the urgent need for novel therapeutic strategies, immunotherapies, especially
chimeric antigen receptor (CAR)-expressing T cells, represent a promising
approach for specific and effective targeting of GBM. However, CAR T cells
can be associated with serious side effects. To overcome such limitation, we
applied our switchable RevCAR system to target both the epidermal growth
factor receptor (EGFR) and the disialoganglioside GD2, which are expressed in
GBM. The RevCAR system is a modular platform that enables controllability,
improves safety, specificity and flexibility. Briefly, it consists of RevCAR T cells
having a peptide epitope as extracellular domain, and a bispecific target module
(RevTM). The RevTM acts as a switch key that recognizes the RevCAR epitope and
the tumor-associated antigen, and thereby activating the RevCAR T cells to kill
the tumor cells. However, in the absence of the RevTM, the RevCAR T cells are
switched off. In this study, we show that the novel EGFR/GD2-specific RevTMs
can selectively activate RevCAR T cells to kill GBM cells. Moreover, we show that
gated targeting of GBM is possible with our Dual-RevCAR T cells, which have
their internal activation and co-stimulatory domains separated into two
receptors. Therefore, a full activation of Dual-RevCAR T cells can only be
achieved when both receptors recognize EGFR and GD2 simultaneously via
RevTMs, leading to a significant killing of GBM cells both in vitro and in vivo.

Silicon carbide (SiC) is a suitable candidate for studying hybrid spin-mechanical systems due to its established use as a sensor material[1] and the capability of its hexagonal polytype (4H-SiC) to host highly coherent spin-centers[2], such as silicon vacancies (V_Si). To realize such a system, spin resonances associated with V_Si need to be coupled to the mechanical modes, which will allow more sensitive magnetic field sensing[3]. To achieve this, we will fabricate mechanical resonators in 4H-SiC and create V_Si by helium ion implantation.
To study the influence of created V_Si on the mechanical properties, we first considered a system with 3C-SiC (grown on Si) as shown in the figure, which provides higher-quality mechanical resonators compared to 4H-SiC grown on 4H-SiC. In our preliminary experiments, we implanted the resonators with broad beam He+ implantation to create ensembles of V_Si. We intend to show how the mechanical properties can be modified varying fluence, in terms of resonance frequencies, mechanical quality factors and, stress. In future, we plan to use focused He+ implantation to study the positional dependence and number of V_Si on the modification of the material. Finally, we will employ an Optically Detected Spin-Mechanical Resonance (ODSMR) scheme to characterize the coupling of spins and phonons[3].
References:
[1] F. Zhao et al., “Photoelectrochemical etching to fabricate single-crystal SiC MEMS for harsh environments”, Materials Letters 65, 409–412 (2011)
[2] D. Riedel et al., “Resonant Addressing and Manipulation of Silicon Vacancy Qubits in Silicon Carbide”, Phys.Rev.Lett.109, 226402 (2012)
[3] A. V. Poshakinskiy and G. V. Astakhov, "Optically detected spin-mechanical resonance in silicon carbide mem-branes”, PhysRevB.100.094104 (2019)

Nonsteroidal anti-inflammatory drugs (NSAIDs) are the most widely used therapeutics against pain, fever and inflammation; additionally, antitumor properties have been reported. NSAIDs reduce the synthesis of prostaglandins (PG) by inhibiting the cyclooxygenase (COX) isoforms COX-1 and COX-2. As non-selective inhibition is associated with off-target effects, strategies to achieve selectivity for the clinically preferred isoform COX-2 are of high interest. The modification of NSAIDs using carborane clusters as phenyl mimetics has been reported to alter the selectivity profile through size exclusion. Inspired by these findings, we have prepared isonimesulide and its carborane derivatives. The biological screening showed that the carborane containing compounds exhibit a stronger antitumor potential compared to nimesulide and isonimesulide. Furthermore, the replacement of the phenyl ring of isonimesulide with a carborane moiety resulted in a shift of the COX activity from non-active to COX-active compounds.

Die Herstellung und Zusammensetzung des MgO-Spritzbetons sind im Bericht des Projektkoordinators, dem Institut für Bergbau und Spezialtiefbau der TU Bergakademie Freiberg (FKZ 02E11769A), beschrieben.
Im Teilprojekt des HZDR wurden bildgebende Methoden angewendet, um die innere Struktur des Materials zu charakterisieren und die Art des Transports von Lösungen anhand prozesstomographischer Bildgebung aufzuklären. Hierfür wurde einerseits Mikrofokus-Röntgen-Computertomographie (µCT), andererseits Positronen-Emissions-Tomographie (PET) eingesetzt. Bei dem Material handelt es sich um Proben aus dem GV2-Bauwerk (Projekt CARLA II, FKZ 02C1204, Dammbauwerk im Carnallitit aus MgO-Spritzbeton mit Kieszuschlag), die nach einer Alterung über etwa 10 Jahre gewonnen wurden, sowie um frisch hergestellte Proben mit veränderter Rezeptur aus den Versuchen GSBV3 und GSBV4 (in-situ Großspritzbetonversuche mit Salzzuschlag). Eine Probe aus der GSBV4 konnte vor und nach der Durchströmung mit Salzlösung untersucht werden.
Die Proben in Bohrkerngröße wurden mit µCT strukturell charakterisiert. Die Tomogramme haben eine Auflösung von 50 µm. Dies erlaubt die Charakterisierung größerer Porenklassen und der Körnung.
Es zeigte sich, dass die Verteilung der Körnung und die Porenradienverteilung mit dem Abstand zur Betonierabschnittsgrenze (BAG) in charakteristischer Weise variieren: Mit Annäherung zur BAG nimmt der Anteil feiner Poren an der Gesamtverteilung zu, große Poren zeigen ein uneinheitliches Muster. Gleichzeitig nimmt der Anteil grober Körnung ab. Dieses Verhalten ist plausibel, weil große Körner nicht die BAG durchdringen können.
Die Zunahme des Anteils feiner Poren bedeutet eine homogenere, feinere Struktur des Materials in der Nähe der BAGs, aber nicht notwendig eine Abnahme der Permeabilität. Wegen der begrenzten Ausdehnung der Zone würde sich eine Veränderung der Permeabilität mittels üblicher Verfahren kaum nachweisen lassen, deshalb wurde das Fortschreiten einer mit ²²Na markierten Lösung mit Hilfe von Langzeit-PET-Aufnahmen dargestellt. Dies lieferte verlässlichere Information über den Prozessverlauf, insbesondere über dessen Homogenität oder präferentielle Wegsamkeiten.
Hierfür wurden spezielle Druckkammern und Injektionsverfahren entwickelt. Einerseits wurde ein Schutzring-Oberflächenpacker angewendet, wobei die Probe sich nicht unter einem Einspanndruck befand, andererseits wurde ein strahlungstransparentes Druckgefäß entwickelt, in dem sich die Probe unter hydrostatischem Einspanndruck befindet, wie dies für Permeabilitätsuntersuchungen gebräuchlich ist.
Es hat sich anhand der µCT-Untersuchungen gezeigt, dass die frischen Proben großräumig verbundene Poren besitzen können, deren maximale Ausdehnung von einigen Zentimetern nicht die Größe der Probe erreicht. Zwischen solchen porösen Bereichen befinden sich kurze Abschnitte, oft unterhalb einer Länge von 1 mm, die als Engstellen die bereits anfänglich geringe Permeabilität bewirken.
PET-Untersuchungen an solchen Proben zeigten den merklichen Einfluss solcher lokalen Wegsamkeiten. Sie konnten aber insofern nicht erfolgreich durchgeführt werden, weil die einsetzende – gemäß µCT-Untersuchungen isotrope – Expansion der Proben im Kontakt mit der Lösung Risse bewirkte.
Dagegen bleiben Proben nach Lösungsinjektion unter Einspanndruck intakt. Nach der Durchströmung mit Salzlösung zeigte es sich anhand der µCT-Bilder, dass auch eine eingespannte Probe merklich expandiert war, aber verbundene poröse Zonen weitgehend verschwunden waren. Vor allem hatte der Anteil von Poren mit Größen unter 1 mm signifikant abgenommen, größere Poren blieben als isolierte Objekte erhalten. PET-Untersuchungen im Anschluss daran zeigten keine präferentiellen Wegsamkeiten, sondern homogene Ausbreitung des Tracers.
Eine gealterte Probe aus dem GV2-Bauwerk wies ebenfalls isolierte Luftporen größer als 1 mm auf. In der PET-Untersuchung bewirkte eine solche angeschnittene und tiefer reichende Pore im Bereich der BAG ein anfängliches lokales Eindringen des Tracers bis in Zentimeter-Tiefe, darüber hinaus geschah die Ausbreitung der Lösung ebenfalls homogen, bei einer Permeabilität von 1e‑20 m².
Dieses Ergebnis weist darauf hin, dass durch den Kontakt mit Salzlösung und generell durch den Alterungsprozess ursprünglich vorhandene flächige Wegsamkeiten verschlossen werden und der anfänglich ablaufende räumlich heterogen verteilte Prozess danach unter signifikanter Reduktion des Porenanteils unterhalb des Millimeterbereichs durch langsamen homogenen Transport ersetzt wird.
Daraus folgt, dass als Untersuchungsmethodik für die strukturelle Analyse eine Kombination von Quecksilber-Kapillardruckmessungen (mercury injection porosimetry MIP), für die Charakterisierung der transportwirksamen Porosität, und µCT, zum Ausschluss verbundener makroskopisch poröser Bereiche, geeignet ist. Sofern solche verbundenen Bereiche ausgeschlossen werden können, lassen sich einfache homogene Rechenmodelle für Transportsimulationen einsetzen. Für die Verifikation, sowohl der Transportmodelle, als auch der räumlichen Homogenität des Prozesses, eignet sich die PET-Methodik.

Research of the spin-wave (SW) dynamics in confined rectangular microstructures is important for the their
potential use for information transport and processing [1]. The design of a microstructure can affect the SW be-
havior, which can be used as a manipulating mechanism [2, 3]. The development of planar microresonators/mi-
croantennas with a micro-coil (loop) allows for measuring FMR of a single ferromagnetic microstrip including
resonance lines corresponding to the SW excitations [4, 5]. TR-STXM [6] with the use of the planar microres-
onators enables direct, time-dependent imaging of the spatial distribution of the precessing magnetization across
the nm-thin microstrips during FMR excitation at the GHz frequency range with elemental selectivity [7, 8]
[...]

The asymmetry of spin-wave patterns in confined rectangular Ni80Fe20 microstrips, both in single and double-strip geometries, is quantified. The results of time-resolved scanning transmission x-ray microscopy (TR-STXM) and micromagnetic simulations are compared. The micromagnetic simulations were set up based on the parameters determined from ferromagnetic resonance measurements at 14.015 GHz. For the TR-STXM measurements and the corresponding simulations the excitation was a uniform microwave field with a fixed frequency of 9.43 GHz, while the external static magnetic field was swept. In the easy axis orientation of the analyzed microstrip, the results show a higher asymmetry for the double microstrip design, indicating an influence of the additional microstrip placed in close proximity to the analyzed one.

Matter at extreme densities and pressures is ubiquitous throughout our universe and naturally
occurs in astrophysical objects such as giant planet interiors. In addition, such warm dense
matter (WDM) is important for technological applications such as inertial confinement fusion
and the discovery of novel materials. Consequently, WDM is routinely studied in experiments
at large research facilities around the globe, including NIF, LCLS, Omega, and the Sandia Z-
machine in the USA, SACLA in Japan, and the European XFEL in Germany.
In practice, the extreme conditions render the accurate diagnostics of WDM a formidable
challenge as even basic parameters such as the temperature cannot be directly measured, and
have to be inferred indirectly from other observations. In this context, a particularly important
property is given by the electronic density response to an external perturbation, which is
probed for example in X-ray Thomson scattering (XRTS) experiments.
In this talk, I give an overview of a number of recent developments in this field [1].
Specifically, I show how we can use state-of-the-art computational methods such as quantum
Monte Carlo (QMC) [2,3] and density functional theory (DFT) simulations [4] to model a
gamut of electronic density response properties of WDM with unprecedented accuracy. In
addition, I present a new approach that allows one to diagnose the temperature of arbitrary
materials from XRTS experiments in the imaginary-time domain without any simulations or
approximations [5]. Finally, I outline a strategy for future developments based on the close
interplay between simulations and experiments.
Keywords: Warm-dense matter, Inelastic X-ray scattering, Path-integral Monte Carlo,
Density functional theory
References:
[1] T. Dornheim et al., Phys. Plasmas 30, 032705 (2023)
[2] T. Dornheim, J. Vorberger, and M. Bonitz, PRL 125, 085001 (2020)
[3] M. Böhme, Zh. Moldabekov, J. Vorberger, and T. Dornheim, PRL 129, 066402 (2022)
[4] Zh. Moldabekov et al., J. Chem. Theory. Comput. 19, 1286-1299 (2023)
[5] T. Dornheim et al., Nature Comm. 13, 7911 (2022)

The main techniques used to characterize raw materials are currently bulk or 2D. This is a consequence of the current lack of standardized and automated methods to characterize particulate materials in 3D. Here, we apply a workflow to characterize a crushed chromite ore with nine particle size classes below 1 mm using X-ray computed tomography. All data processing of all samples follows the same sequence of steps, which means that the analysis can be automated with limited user input as opposed to traditional 3D image processing methods. Results of chromite composition, particle size distribution and chromite liberation are obtained for individual particles and compared with the results from x-ray diffraction and 2D-based automated mineralogy. The results shows a consistent accuracy across all size classes down to 75 μm. For the larger particle sizes (>600 μm) the chromite liberation curves are more consistent than those obtained from 2D-based automated mineralogy, possibly due to the stereological bias of 2D sections. The particle size distributions is the property for which the 2D bias is more contrasting with 3D. In conclusion, the workflow is more automatable (thus, faster and cheaper) and less bias (thus, more accurate and standardisable) than other 3D image analysis methods. Additionally, it stands as complementary to established techniques for particle-based characterization, especially to measure particle properties that 2D-based methods may not measure representatively. Further testing of the workflow in progressively more complex materials is necessary, but its potential to transform the way mineral particulate materials are characterized is demonstrated.

Spin pumping from a metallic ferromagnet (FM) into an insulating antiferromagnet has been studied across the magnetic phase transition by means of temperature-dependent, broad-band ferromagnetic resonance (FMR) experiments. A set of spin pumping heterostructures consisting of Permalloy (Ni80Fe20) as FM and Zn1−xCoxO with x = 0.3, 0.5 and 0.6 (Co:ZnO) as antiferromagnetic insulator has been used where previous experiments have already pointed out the possibility of the existence of spin-pumping. The present experiment allow to reliably separate the various contributions of the temperature-dependent Gilbert damping parameter to the FMR line-width. A careful analysis of the obtained data demonstrates a significant increase of the temperature-dependence of the Gilbert damping parameter alpha(T ) around the magnetic phase transition of Co:ZnO which extends up to room temperature, confirming spin pumping into the fluctuating spin sink of an antiferromagnetic/paramagnetic insulator.

Additive manufacturing (AM) can produce complex vascular network configurations, yet limited testing has been done to characterize the damage and healing behavior of concrete with embedded networks for self-healing. In this study, different AM methods and network wall materials were used to produce vascular networks for self-healing concrete prisms, where their load-response behavior, healing efficiency and microstructure were evaluated using non-destructive techniques: acoustic emission (AE), ultrasonic pulse velocity (UPV), digital image correlation (DIC), and X -ray computed tomography (CT). The types of healing agent release mechanisms that were studied include a ductile-porous network that supplies fluid from its pores and a brittle network that fractures under load to release fluid. DIC coupled with AE verified debonding of ductile-porous networks from the cementitious matrix, and was able to track damage progression as well as healing for all networks with load regains up to 56% and stiffness regains up to 91% using polyurethane.

The experimental investigation of matter under extreme densities and temperatures, as in
astrophysical objects and nuclear fusion applications, constitutes one of the most active frontiers at
the interface of material science, plasma physics, and engineering. The central obstacle is given by
the rigorous interpretation of the experimental results, as even the diagnosis of basic parameters like
the temperature T is rendered difficult at these extreme conditions. Here, we present a simple,
approximation-free method [1,2] to extract the temperature of arbitrarily complex materials in
thermal equilibrium from X-ray Thomson scattering experiments, without the need for any
simulations or an explicit deconvolution. Our paradigm can be readily implemented at modern
facilities and corresponding experiments will have a profound impact on our understanding of warm
dense matter and beyond, and open up a variety of appealing possibilities in the context of
thermonuclear fusion, laboratory astrophysics, and related disciplines.
[1] T. Dornheim, M. Böhme, D. Kraus, T. Döppner, Th. Preston, Zh. Moldabekov, and J. Vorberger,
Accurate temperature diagnostics for matter under extreme conditions, Nature Comm. 13, 7911
(2022)
[2] T. Dornheim, M. Böhme, D. Chapman, D. Kraus, T. Döppner, Th. Preston, Zh. Moldabekov, and
J. Vorberger, Temperature analysis of X-ray Thomson scattering data, arXiv:2212.10510

Monoclinic gallium oxide (β-Ga2O3) is the chemically and thermally most stable compound, compared to its other four polymorphs, with an ultra-wide bandgap of 4.9 eV. It is a promising semiconductor material for power electronics, optoelectronics, and batteries. However, controlling the metastable polymorph phases is quite hard, and the fabrication technology at the nanoscale is immature. Our goal is to understand polymorph conversion. Controlling the crystalline structure will allow us to establish new fabrication methods of single-phase polymorph coatings, buried layers, multilayers, and different nanostructures in Ga2O3 using focused ion beams (FIBs). The research aims to better understand and control the polymorph conversion with special emphasis on laterally resolved modifications by utilizing focused ion beams.
In a previous study, our project partners Kuznetsov et.al. [1] demonstrated the ion-beam-induced β-to-κ phase transformation in Ga2O3 as shown in Fig.1. However, later, Garcia Fernandez et.al. [2] showed that the monoclinic β-phase actually transforms into the cubic γ-phase.
Here, we used Helium Ion Microscopy (HIM) and other focused ion beams (FIBs) to locally irradiate the (-201) oriented β-Ga2O3 sample with different ions (Ne, Co, Nd, Si, Au, In) to induce the polymorph transition. The successful conversion into γ- Ga2O3 under Ne+ irradiation (Fig.2(a)) has been confirmed using Electron Backscattered Diffraction (EBSD) and indexing the Kikuchi patterns (Fig.2(b)). Furthermore, Positron Annihilation Lifetime Spectroscopy (PALS) was performed for broad beam irradiated implants to better understand the fluence-dependent creation and distribution of defects. Transmission Electron Microscopy (TEM) images also provide information about the distinct and sharp interfaces between different polymorphs of Ga2O3. The first results indicate that the damage/strain created by the FIB irradiation leads to a local transformation of β- Ga2O3 to γ- Ga2O3.

The cost-efficient production of green hydrogen using renewable energies requires next-generation proton exchange membrane (PEM) electrolysers to be operated at higher current density. Under this new operating condition, the elevated temperature of the ultra-pure water and its supersaturation with oxygen on the anode side have strong effects on the formation and transport of gas bubbles. The resulting gas-liquid two-phase flow through the porous transport layer at the membrane electrode assembly is characterised by up to 50 % gas fraction, which is exceptionally high. Such a foam-like flow within the porous medium is not accessible by optical measurements. Instead, we performed imaging flow measurements by means of time-resolved radiography using polychromatic X-rays as well as thermal neutrons at 100 frames per second imaging frame rate. On a laboratory scale, we aimed to study the bubble transport by mapping the local gas fraction distribution over time. This conference contribution presents two model experiments with open-porous metal and polymer foams, namely made of nickel and polyurethane, showcasing the advantages but also limitations of X-ray and neutron radiography for investigating bubble transport phenomena within such foam structures. In both experiments, foam samples of approximately 70 mm x 70 mm in width and height were sandwiched between the X-ray- or neutron-transparent front and back windows of a vessel filled with deionised water. As neutrons are strongly attenuated in water, the thickness of the water-filled vessel and the foam sample were set to 5 mm along the beam direction in all measurements. Bubbles were generated continuously by injecting compressed air at different but constant volumetric flow rates through a single hollow needle releasing the bubbles directly into the water-soaked foam. Based on calibration radiographs acquired both in the absence and presence of water, quantitative image analysis yielded a pixelwise mapping of the gas fraction at approximately 0.06 mm image pixel size without binning. While X-ray radiography visualised the pulsating transport of bubble plumes through a nickel foam of 1.2 mm pore size, neutron radiography gave insights into the jumping motion of single bubbles through a polyurethane foam of approximately 3 mm pore size. In conclusion, we characterised the gas transport depending on the volumetric gas flow rate, the bubble size in relation to the foam pore size and the wettability of the inner foam surface. Further radiographic studies will consider bubble flows through open-porous materials with different pore geometry or functionalised surface wettability.

The flow behaviour of liquid foam is of central importance in froth flotation for mineral processing. Flotation separates valuable mineral particles from gangue material based on the surface wettability. To this end, the solids are finely ground and suspended in an aqueous solution with flotation reagents. In aerated flotations cells, gas bubbles selectively attach to the hydrophobic mineral particles, rise to the surface, and form a froth. To recover the valuables, they are transported out of the flotation cell with the froth. In flotation plants, the recovery of solid and liquid is monitored by optical observation of the overflowing froth. However, this monitoring is limited to the free surface of the particle-laden froth. Aiming for detailed insights into the flow behaviour underneath the surface-near foam bubbles, the laboratory-scale experiment in this work investigates the velocity field of an overflowing foam in combined optical and X-ray measurements. For this purpose, foam was generated continuously, moved similar to a plug-flow in a vertical channel with rectangular cross-section, and flowed off over a one-sided horizontal weir into the open surrounding. The imaging measurements focused on the foam flow in the region of interest around the weir. Simultaneously, the liquid fraction of the foam was monitored by measuring its electric conductivity between electrode pairs mounted near the weir. We used aqueous foams of two different surfactant concentrations but similar bubble size range and superficial gas velocity, yielding around 10 % liquid fraction. The optical measurements carried out through the transparent side wall of the flow channel as well as at the free surface of the overflowing foam. They captured light reflections on the foam bubbles were analysed by an adapted particle image velocimetry algorithm. While the opacity of the foam limits optical measurements to the wall- or surface-near foam bubbles, our approach of X-ray particle tracking velocimetry with custom-tailored tracer particles sheds light on the velocity field in a truly three-dimensional measurement volume. We prepared tracers consisting of small 3D-printed polymer tetrahedra with tiny metal beads glued to the tetrahedral tips. Owing to their shape and the light-weight material composite, these tracers adhered to the bubble-scale foam structure and, therefore, were carried with the foam flow very well. X-ray radiography visualised the motion paths of each tracer’s metal beads, representing the local streamlines of the foam flow. Besides, the X-ray images mapped the liquid fraction distribution in the entire field of view, i.e. also directly at the weir, thus extending the local measurement of the liquid fraction by means of the electrode pairs. The tracer-based X-ray measurements revealed the velocity profile increasing in vertical direction above the weir, whereas the optical flow measurements were subjected to wall and surface effects, resulting in lower velocities. Combining all measurement results, we identified an unexpected velocity maximum underneath the free surface of the overflowing foam.

The development of novel ligands for G-protein-coupled receptors (GPCRs) typically entails the characterization of their binding affinity, which is often performed with radioligands in a competition or saturation binding assay format. Since GPCRs are transmembrane proteins, receptor samples for binding assays are prepared from tissue sections, cell membranes, cell lysates, or intact cells. As part of our investigations on modulating the pharmacokinetics of radiolabeled peptides for improved theranostic targeting of neuroendocrine tumors with a high abundance of the somatostatin receptor sub-type 2 (SST₂), we characterized a series of ⁶⁴Cu-labeled [Tyr³]octreotate (TATE) derivatives in vitro in saturation binding assays. Herein, we report on the SST₂ binding parameters measured toward intact mouse pheochromocytoma cells (MPC) and corresponding cell lysates and discuss the observed differences taking the physiology of SST₂ and GPCRs in general into account. Furthermore, we point out method-specific advantages and limitations.

The actinides (An) are located at the bottom of the periodic table. These elements are exclusively radioactive, highly chemo-toxic, and play an important role in chemical engineering and environmental science related to the nuclear industry or nuclear waste repositories. In contrast to the strongly shielded 4f electrons of the lanthanides, 5f electrons of particularly the early An are found to participate in bonding, e.g. to organic ligands. Another characteristic of the An is their huge variety of possible oxidation states, typically ranging from +II to +VII for early actinides, making their chemistry complex but interesting. 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. Observed changes in e.g. the binding situation or magnetic effects among the An series may deliver insight into their unique electronic properties mainly originating from the f-electrons. A question still remaining in the field of An chemistry is the degree of “covalency” in compounds across the actinide series, which may be addressed by systematic studies on series of An compounds, including transuranium (TRU) elements.
We investigate the coordination chemistry of low-valent actinides using organic N-, O-, or S-donor ligands. Information on covalency trends as well as mutual ligand influences can be obtained by the analysis of solid-state structures derived by SC-XRD in combination with quantum chemical calculations (QCC) and high-energy-resolution fluorescence detection X-ray absorption near edge spectroscopy (HERFD-XANES). In solution, NMR spectroscopy permits to draw conclusions about the complex speciation in solution, the intrinsic magnetic properties of the actinides, or subtle changes in covalency in the ligand-actinide-bonding.

Bayes Hilbert spaces \(B^2(P)\) describe a Hilbert space structure
on a set of mutally continues probability measures, improper priors
and likelihoods with origin \(P\).

The talk will give an overview of Bayes Spaces and their relation to
various concepts of mathematical statistics. Several deep results of
statistics and information theory become obvious and geometrically
intuitive corrolaries, when viewed in the light of this vector space
structure.

The name comes from the fact that vector addition in this space is
given by Bayes theorem. A distribution family is an exponential
family if and only if its a finite dimensional subspaces of a Bayes
Space. In case of regular exponential families its a Bayes Hilbert
Space. The geometry of the space is closely related to Fisher
information. There is a cannocial isometric mapping to \(L^2_0(P)\)
called centered log ratio transform, proving score functions. The
\(P\)-a.s. constant ratio of this centred log ratio transform to the
log density is Kulback Leibler Divergence. The Basis vectors of
conjugated priors can be directly interpreted in terms of
information and the basis of the original family. I.e. we explicitly
give the conjugated prior for every exponential family.

In a multivariate setting, we can identify conditional distributions
with qotient spaces, and provide a straight forward decomposition
into a sum of products of marginal spaces closely related to the
Hammersley Clifford Theorem, Graphical models and generalizing
log-linear models to continues distributions.

Ultraviolet germicidal irradiation has proven to be an efficient method of rendering airborne microorganisms inactive. In the present study, a novel model for airborne virus/bacteria inactivation using UV-light is presented. A particle-to-particle photonic approach that takes into account each of the interactions between the microorganism particles and UV-light photons is obtained. The main advantage of the presented model is its faithfulness to the physical reality of the inactivation process, i.e. that the ultraviolet inactivation effect is a stochastic process not a deterministic one. This characteristic allows the model to track and calculate the inactivation success for each of the single particles conforming a particle cloud. The model is validated against published data of inactivation of aerolized Escherichia coli bacteria in a UV-reactor.

Since the coming of the COVID-19 pandemic in 2019, virus spreading in confined spaces has been in the spotlight. Ultraviolet germicidal irradiation has proven to be an efficient method of rendering airborne microorganisms inactive. In the present study, a novel model for airborne virus/bacteria inactivation using UV-light is presented. A particle-to-particle photonic approach that takes into account each of the interactions between the microorganism particles and UV-light photons is obtained. The main advantage of the presented model is its faithfulness to the physical reality of the inactivation process, i.e. that the ultraviolet inactivation effect is a stochastic process not a deterministic one. This characteristic allows the model to track and calculate the inactivation success for each of the single particles conforming a particle cloud. The model is validated against published data of inactivation of aerolized Escherichia coli bacteria in a UV-reactor and will be validated experimentally using a seasonal coronavirus in a Potential Aerosol Mass Oxidation Flow Reactor at the Helmholtz-Zentrum in Munich.

Publishing raw PIC-simulation results according to the FAIR principle is difficult,
primarily size with a single large simulation's raw data reaching 100s TeraByte up to
1-2 PetaByte.
Fulfilling the FAIR principles therefore requires a different approach, with only
compressed results and simulation setup/initial state made directly available in direct
access public data bases.
This assures findability of simulations if initial conditions are automatically searchable, makes raw data on slow, high capacity archive storage accessible for specific simulations of interest, or allows rerunning the same simulation if additional data is required.

This is currently hindered by the different historically grown input description standards of different PIC-codes.

Simulation setups can neither be parsed, searched or understood without implementing a dedicated parser for each code and with more than 4 PIC-simulation codes, (PIConGPU, WARPX, Smilei, PICLS, ...) in use at HZDR alone this is unfeasible.
To realise the above a common standardized description for PIC-codes is needed. PICMI is being implemented and developed by HZDR and Berkley Labs for this purpose.
Besides fulfilling the above requirements, PICMI will also allow reuse of user interfaces between codes, make the simulations more accessible to users and allow using a common setup for different codes thereby al Bytelowing easy direct comparisons between codes for better reproducibility as well as lay the ground work for automated machine learning on simulations.

Atomic Population Kinetics for ParticleInCell

Standard atomic physics models in PIC simulation either neglect excited states, predict
atomic state population in post processing only, or assume quasi-thermal plasma conditions.

This is no longer sufficient for high-intensity short-pulse laser generated plasmas, due
to their non-equilibrium, transient and non-thermal plasma conditions, which are now becoming
accessible in XFEL experiments at HIBEF (EuropeanXFEL), SACLA (Japan) or at MEC (LCLS/SLAC).
To remedy this, we have developed a new extension for our PIC simulation framework PIConGPU
to allow us to model atomic population kinetics in-situ in PIC-Simulations, in transient
plasmas and without assuming any temperatures.
This extension is based on a reduced atomic state model, which is directly coupled to the
existing PIC-simulation and for which the atomic rate equation is solved explicitly in
time, depending on local interaction spectra and with feedback to the host simulation.
This allows us to model de-/excitation and ionization of ions in transient plasma conditions,
as typically encountered in laser accelerator plasmas.
This new approach to atomic physics modeling will be very useful in plasma emission
prediction, plasma condition probing with XFELs and better understanding of isochoric
heating processes, since all of these rely on an accurate prediction of atomic state
populations inside transient plasmas.

Inductive flow measurement techniques such as the Contactless Inductive Flow Tomography require sensors that provide a magnetic field resolution of 1 nT while operating in magnetic fields of several mT. With advancements in state-of-the-art magnetoresistive thin-film sensors the required behavior regarding sensitivity, precision and hysteresis can be achieved [1]. Planar Hall Effect sensor have been shown to be one of the leading sensor types in this area. Therefore we present a detailed study on the effect of different sensor layouts, geometries, magnetic flux concentrators and other parameters on the characteristics of single layer Permalloy Planar Hall Effect sensors. [1] Granell, Pablo Nicolás, et al. npj Flexible Electronics 3.1 (2019): 1-6.

Magnetic shape memory alloys have been examined intensively due to their multifunctionality and multitude of
physical phenomena. For both areas, epitaxial films are promising since the absence of grain boundaries is beneficial for applications in microsystems and they also allow to understand the influence of a reduced dimension on the physical effects. Despite many efforts on epitaxial films, two particular aspects remain open. First, it is not
clear how to keep epitaxial growth up to high film thickness, which is required for most microsystems. Second, it
is unknown how the microstructure of premartensite, a precursor state during the martensitic transformation,
manifests in films and differs from that in bulk.
Here, we focus on micrometer-thick austenitic Ni-Mn-Ga films and explain two distinct microstructural features
by combining high-resolution electron microscopy and X-ray diffraction methods. First, we identify pyramid-
shaped defects, which originate from {1 1 1} growth twinning and cause the breakdown of epitaxial growth.
We show that a sufficiently thick Cr buffer layer prevents this breakdown and allows epitaxial growth up to a
thickness of at least 4 μm. Second, premartensite exhibits a hierarchical microstructure in epitaxial films. The reduced dimension of films results in variant selection and regions with distinct premartensite variants, unlike its
microstructure in bulk.

INTRODUCTION
Radioactive strontium isotopes are products of the fission of uranium in the context of nuclear energy production. Furthermore, strontium is often used in geochemical calculations as an analog for radium, both being alkaline earth metals.
In the THEREDA database [1,2], a thermodynamic Pitzer dataset for Sr in the system of oceanic salts (Na⁺, K⁺, Mg²⁺, Ca²⁺ | Cl⁻, SO₄²⁻ – H₂O) is available [3]. Yet, this dataset is valid for the temperature T = 25 °C only. However, several strontium solid phases show a large variation in solubility with temperature, e.g. strontium chloride hydrates (SrCl₂∙xH₂O with x = 6, 2 and 1) [4] or strontium hydroxide (Sr(OH)₂∙8H₂O) [5].
In this work, a polythermal extension of the existing Sr dataset for the chloride system is presented, which is valid in the range T = 0–100 °C.

DESCRIPTION OF THE WORK
Experimental data (osmotic coefficients) from literature were used to generate a temperature function for the binary Pitzer interaction coefficients (β⁰, β¹, and CΦ). Solubility data of SrCl₂ in water [4] were then used to parameterize temperature functions for the solubility products of the different strontium chloride hydrates. Consistency with the existing 25 °C data set was ensured.
Solubility data of SrCl₂ in water [4] were then used to parameterize temperature functions for the solubility products of the different strontium chloride hydrates. Polythermal expansions of the ternary Pitzer coefficients also were required for a few subsystems only.
Furthermore, the data set was extended to quaternary acidic systems (Sr²⁺, H⁺ | Cl⁻ – H₂O).

RESULTS
With the obtained dataset, it is possible to model the ternary system (Sr²⁺, Na⁺ | Cl⁻ – H₂O) in the temperature range T = 0–100 °C. The solubility of all known solid phases is correctly reproduced, see Fig. 1. The dataset now also allows polythermal calculation of higher systems such as the quaternary system (Sr²⁺, Na⁺, K⁺ | Cl⁻ – H2O) in the temperature range for which experimental solubility data are available (T = 15–50 °C), see Fig. 2. For those two systems, no adjustment of the existing ternary Pitzer interaction coefficients was necessary.
The presented polythermal extension of the strontium Pitzer model allows robust calculation of the geochemical behavior of strontium in the chloride system over a wide temperature range. This extension of the THEREDA data set will become part of the next official data release and will be complemented by polythermal data for strontium sulfate (SrSO₄) and hydroxide (Sr(OH)₂∙8H₂O) in future work.

ACKNOWLEDGMENTS
THEREDA is funded by the German “Bundesgesellschaft für Endlagerung (BGE)”, contract number 45181017.

REFERENCES
1. THEREDA – Thermodynamic Reference Database. Release 2021, https://www.thereda.de/, (2022).
2. H. C. Moog et al., “Disposal of Nuclear Waste in Host Rock formations featuring high-saline solutions - Implementation of a Thermodynamic Reference Database (THEREDA)” Appl. Geochem., 55, 72–84 (2015), DOI: 10.1016/j.apgeochem.2014.12.016.
3. T. Scharge “Thermodynamic model for the systems Sr – Na, K, Mg, Ca – Cl, SO₄ – H2O at 298.15 K”, THEREDA Report (2016).
4. B. S. Krumgalz “Temperature Dependence of Mineral Solubility in Water. Part I. Alkaline and Alkaline Earth Chlorides” J. Phys. Chem. Ref. Data, 46, 043101, DOI: 10.1063/1.5006028.
5. I. Lambert et al. “Alkaline Earth Hydroxides in Water and Aqueous Solutions” IUPAC Solubility Data Series Vol. 52, Pergamon Press, Oxford, 388 p.

(Fe(II)(NCCH₃)(NTB))(OTf)₂ (NTB = tris(2- benzimidazoylmethyl)amine, OTf = trifluoromethanesulfonate) was reacted with difluoro(phenyl)-λ³-iodane (PhIF₂) in the presence of a variety of saturated hydrocarbons, resulting in the oxidative fluorination of the hydrocarbons in moderate-to-good yields. Kinetic and product analysis point towards a hydrogen atom transfer oxidation prior to fluorine radical rebound to form the fluorinated product. The combined evidence supports the formation of a formally Fe(IV)(F)₂ oxidant that performs hydrogen atom transfer followed by the formation of a dimeric μ-F−(Fe(III))₂ product that is a plausible fluorine atom transfer rebound reagent. This approach mimics the heme paradigm for hydrocarbon hydroxylation, opening up avenues for oxidative hydrocarbon halogenation.

Droplet-induced self-folding processes enable the easy and cost-effective fabrication of submillimeter 3D structures from planar templates. These templates were fabricated by laser cutting of polymer foils that offers a high flexibility in design. The interaction of water droplets with template surfaces induces a surface tension force that causes deformation of the laser-cut templates needed to form the 3D structures. In this study, laser patterning of 25 µm thick polyimide (PI) foils by UV ultrashort pulse laser ablation was used to systematically investigate the effect of hinge thickness on the bending and self-folding process of cubes. The deposition of water droplets on the laser-structured samples leads to forces that move the side faces of the cube template causing a defined deformation of the hinges of the PI template and resulting in a bending angle between hinged template regions. The bending angle was determined as a function of hinge geometry and water droplet volume. The bending angle is increased with increasing droplet volume below a certain maximum, but decreased with increasing hinge thickness and width. The results provide guidelines for experimental optimization and reference data for computer-aided optimization of water droplet-induced self-folding of 3D structures.