Publications Repository - Helmholtz-Zentrum Dresden-Rossendorf

Retirement Home facilities have been widely affected by the COVID-19 pandemic. The residents in these homes are usually elderly people with a high risk of mortality from being infected. Since they are in contact with each other, once an infection arrives at the facility, it propagates quickly. To prevent the outbreaks, it has been demonstrated that regular testing of the residents is the most practical approach. However, testing may result in extra time for the staff that performs the test as well as residents' discontent, which presents a trade-off between the time invested in testing, daily caring activities, and viral spread containment. We introduce a novel optimization approach for testing schedule strategies in retirement homes. We develop a mixed-integer linear programming model for balancing the staff’s workload while minimizing the expected detection time of a probable infection inside the facility. We present a probabilistic approach in conjunction with the optimization models to compute the risk of infection, including contact rates, incidence status, and the probability of infection of the residents. To tackle the combinatorial nature of the problem, we proved an efficient property, called symmetry property of optimal testing strategy and utilized it in proposing an enhanced local search algorithm. We perform several experiments with real-size instances and show that the proposed approach can derive optimal testing strategies.

Clay rock formations are considered as host rocks for underground radioactive waste repositories. Reliable predictions of diffusive transport heterogeneity are critical for assessing the sealing capacity of argillaceous rocks. The predictive power of numerical approaches to flow field analysis and radionuclide migration depends on the quality of the underlying pore network geometry. Both sedimentary and diagenetic complexity are controlling factors.
In this study, we demonstrate a cross-scale approach to reconstruct the pore network geometries of the sandy facies of the Opalinus Clay rock. We identified diagenetic and sedimentary subfacies components based on the concentration of diagenetic carbonates and sulfides and grain size variability, and quantified their pore size distributions and pore network geometries. A viable approach for use in transport modeling is to combine μ-CT data segmentation followed by filling the resulting volumes with representative pore network geometries based on FIB-SEM data. The resulting generalized pore network geometries are applied in digital rock models to calculate effective diffusivities, using a combined upscaling workflow for transport simulations from nanometer to micrometer scales.
Positron emission tomography (PET) diffusion experiments validated the transport simulation results. We introduced a statistical treatment of the PET and μ-CT tomographic datasets based on the spatial variability of both PET tracer concentrations and rock density. The analyzed effective diffusivities confirmed the numerical results.
This study illustrates three important steps in migration analysis: (i) a workflow of general applicability for cross-scale identification of pore network data in argillaceous rocks, (ii) application of the pore network data for the numerical analysis of diffusive transport, and (iii) validation of numerical results via combined PET - μ-CT diffusion experiments. Although the conceptual approach is not feasible for large numbers of samples, it opens up a strong potential for generalization: the validated results of effective diffusivities can now be easily used in a variety of segmented geometries. This allows to efficiently test upscaling concepts for the continuum scale on this basis.

This paper is associated with a video winner of the 2021 American Physical Society’s Division of Fluid Dynamics (DFD) Milton van Dyke Award for work presented at the DFD Gallery of Fluid Motion. The original video is available online at the Gallery of Fluid Motion, https://doi.org/10.1103/APS.DFD.2021.GFM.V0036.

We investigated a miscible displacement of a less viscous liquid by a more viscous shear-thinning liquid in a Hele-Shaw cell. Due to a coacervation
reaction between both liquids, a hydrodynamic instability appears in the form of inward viscous fingering. The liquids consisted of a solution of
the anionic biopolymer xanthan gum, as the injection liquid, which displaced a cationic surfactant (C14TAB) aqueous solution (Keshavarzi et al.,
2019). In the contact zone between the two solutions, the oppositely charged species form polymer-surfactant complexes due to electrostatic
interactions. The electrostatic and hydrophobic interactions between these complexes lead to a self-assembly process, forming a membrane
structure separated from the main solution. During the continuing radial displacement, a large variety of patterns can emerge which is attributed
to the rheological properties of the system involving viscosity gradients, the non-Newtonian nature of the displacing solution and the complex
rheology of the coacervate phase. Variation of the flow rate and gap width of the Hele-Shaw cell revealed distinct instability regimes and allowed
to identify main contributing mechanisms. These insights open the door for further investigation of fluid mechanics problems (i.e. Saffman-Taylor
instability) (Saffman & Taylor, 1958) in multiphase systems of complex rheology and its applications in engineering and technology.
References:
Keshavarzi, B., Langmuir. 2019, 35(42), 13624-13635.
Saffman, P., & Taylor, G. Proceedings of the Royal Society A: Mathematical, Physical. 1958, 245(1242), 312-329.
Acknowledgements: This work was supported by the German Aerospace Center (DLR) with funds provided by the Federal Ministry for
Economic Affairs and Energy (BMWi), Grant No. 50WM2061 (project ChemFront).

We present a new Spectral Neighbor Analysis Potential (SNAP) machine-learning potential for large-scale molecular dynamics simulations of Iron. SNAP is a classical interatomic potential that expresses the energy of each atom as a linear function of selected bispectrum components of the neighbor atoms. The development of the SNAP potential entails three steps: (1) the creation of a training database comprised of a consistent and meaningful set of first-principles Density Functional Theory (DFT) data for Iron at a range of high pressures (0-400 GPa) and temperatures (0-6500 K); (2) the robust and physically guided training of the SNAP hyper-parameters based on DFT data using statistical data analysis; and (3) the validation of the SNAP potential in molecular dynamics simulations of Iron by evaluating transport properties at extreme conditions up to those prevalent in Earth's core.

We present results for direct maskless magnetic patterning of ferromagnetic nanostructures using a special liquid metal alloy ion source for focused ion beam (FIB) systems. We used a Co36Nd64 alloy as the FIB source [1]. A Wien mass filter allows for quick switching between the ion species in the alloy without changing the FIB source. A 5000×1000×50 nm3 permalloy strip served as the sample. Using the FIB we implanted a 300-nm-wide track with Co ions (see Fig.1). We observed the Co-induced changes by measuring the sample with microresonator ferromagnetic resonance before and after the implantation. Structures as small as 30 nm can be implanted up to a concentration of 10 % near the surface. Such lateral resolution is hard to reach for other lithographic methods. This allows for easy magnetic modification of edge-localized spin waves.
In another set of samples, we implanted Dy ions to locally increase the damping in a stripe pattern of ~120-nm-wide strips with 400 nm periodicity on a total area of 1×1 mm². Thus, the Gilbert damping parameter can be easily increased by one order of magnitude with a lateral resolution of about 100 nm.
In contrast to electron beam lithography in combination with broad-beam ion implantation, the maskless FIB process does not require the cumbersome and difficult removal of the ion-hardened resist if optical measurements like BLS or TR-MOKE are needed.

Spin waves are one of the options to replace the transfer of electronic charges in logic devices to make information processing faster and more efficient [1]. A fundamental understanding of the dynamic magnetic properties of confined rectangular strips is a prerequisite for the development of nanoscale computational devices. Planar microresonators/microantennas made it possible not only to measure spin wave dynamics in a single microstrip, but to apply synchrotron-based time-resolved scanning transmission microscopy (TR-STXM) [3] using a phase-locked ferromagnetic resonance (FMR) excitation scheme (STXM-FMR). STXM-FMR enables direct temporally resolved imaging of the spatial distribution of the precessing magnetization within the microstrip during FMR excitation with elemental selectivity. FMR modes in a single rectangular permalloy microstrip were directly imaged using STXM-FMR and the findings were corroborated by micromagnetic simulations showing a very good agreement [5]. Under uniform excitation in a single confined microstrip typically standing spin waves are expected, nevertheless all imaged spin waves are nonstationary at and off resonance.

Objectives: During the last 15 years several PSMA PET ligands for prostate cancer imaging have been developed resulting in the recent approvals of 68Ga-PSMA-11, 18F-PSMA-1007 and 18F-DCFPyL.[1,2] However, 99mTc remains a popular radiometal for SPECT imaging due to its longer half-life and availability from 99Mo/99mTc generators especially in outpatient imaging centers. Due to the widespread availability of SPECT cameras PSMA SPECT ligands have the potential to substantially extend the availability of PSMA-based imaging, but currently no PSMA SPECT ligand is approved. MIP-1404, PSMA-I&S and HYNIC-iPSMA are rare examples of PSMA SPECT tracers in clinical development. Accordingly, the aim of our study was to develop a PSMA ligand for 99mTc SPECT imaging of prostate cancer based on an N2S2 chelator, which enables reliable radiolabeling to form stable 99mTc complexes.[3]

Methods: A number of compounds, which contain the PSMA binding motif Glu-urea-Lys, a varying linker and a bisaminothiol (BAT)-type N2S2 chelator, were synthesized. Selected compounds were radiolabeled with 99mTc, followed by assessment of in vitro stability of the formed complexes via radio-HPLC. The specific binding affinity towards PSMA and the internalization of the radioligands were examined in LNCaP cells, supplemented by autoradiographic studies. Tissue distribution and tumor accumulation were evaluated in LNCaP-tumor bearing mice via quantitative SPECT/CT imaging, benchmarked with [99mTc]Tc-PSMA-I&S[4] and [68Ga]Ga-PSMA-11.

Results: Among the six 99mTc radioligands synthesized and examined, [99mTc]TcO-ABX474 showed most favorable properties. Radiolabeling of ABX474 (50 µg) was achieved starting from [99mTc]NaTcO4 (0.2-2 GBq) in saline (1.4 mL) using SnCl2 (1 µg in 0.01 M HCl) as reducing agent, in presence of calcium-D-heptagluconate (10 µg) and D-mannitol (1 mg) at pH 5-6. Incubation at r.t. for 20 min followed by heating at 80°C for 20 min afforded the product-containing solution with a radiochemical purity of 93.8 ± 3.1 % (n=20) optimization planned during kit development). [99mTc]TcO-ABX474 was stable in DPBS (96.7 ± 2.1 % unchanged, n=3) at 25°C for 20 h as well as in mouse plasma (96.7 ± 1.3 % unchanged, n=3) and human plasma (91.7 ± 0.3 % unchanged, n=5) at 37°C for 6 h, respectively. [99mTc]TcO-ABX474 showed high binding affinity towards PSMA (Kd= 7.2 ± 1.7 nM) and substantial uptake in LNCaP cells (binding: 3.2 %AD/mg protein internalization: 2.8 %AD/mg protein, 47% internalization of total cell bound activity at 37°C).
In LNCaP xenograft mice, [99mTc]TcO-ABX474 showed high PSMA-specific tumor uptake, mainly renal excretion and moderate kidney retention. Hence, [99mTc]TcO-ABX474 exhibited higher tumor-to-background ratios (SUV) between 1‒4 hours after injection (tumor/muscle: 25.2‒52.7 tumor/kidney: 0.3‒0.37) compared to the reference compound [99mTc]Tc-PSMA-I&S (tumor/muscle: 5.7‒18.2 tumor/kidney: 0.17‒0.2). [99mTc]TcO-ABX474 allowed for similar tumor visualization compared to PET/CT imaging with [68Ga]Ga-PSMA-11 (tumor/muscle: 22.9 tumor/kidney: 0.24) 1 hour after injection.

Conclusion: This study demonstrates that [99mTc]TcO-ABX474 is a promising radiotracer candidate for PSMA-specific SPECT imaging of prostate cancer warranting further clinical evaluation.

Acknowledgments: The authors would like to thank the Sächsische Aufbaubank - Förderbank - for financial support (100363946).

References:

[1] https://www.fda.gov/drugs/news-events-human-drugs/fda-approves-second-psma-targeted-pet-imaging-drug-men-prostate-cancer, published on 27/05/2021.

[2] https://www.has-sante.fr/jcms/p_3337433/en/radelumin-18f-psma-1007-cancer-de-la-prostate, published on 04/05/2022.

[3] Hoepping, A. et al., EPO Patent Application EP22174909.6, 23/05/2022.

[4] Robu, S. et al., J Nucl Med 2017, 58, 235-242.

This study addresses the complementary metal-oxide-semiconductor-compatible fabrication of vertically stacked Si/SiO2/Si nanopillars (NPs) with embedded Si nanodots (NDs) as key functional elements of a quantum-dot-based, gate-all-around single-electron transistor (SET) operating at room temperature. The main geometrical parameters of the NPs and NDs were deduced from SET device simulations using the nextnano++ program package. The basic concept for single silicon ND formation within a confined oxide volume was deduced from Monte-Carlo simulations of ion-beam mixing and SiOx phase separation. A process flow was developed and experimentally implemented by combining bottom-up (Si ND self-assembly) and top-down (ion-beam mixing, electron-beam lithography, reactive ion etching) technologies, fully satisfying process requirements of future 3D device architectures. The theoretically predicted self-assembly of a single Si ND via phase separation within a confined SiOx disc of < 500 nm³ volume was experimentally validated. This work describes in detail the optimization of conditions required for NP/ND formation, such as the oxide thickness, energy and fluence of ion-beam mixing, thermal budget for phase separation and parameters of reactive ion beam etching. Low-temperature plasma oxidation was used to further reduce NP diameter and for gate oxide fabrication whilst preserving the pre-existing NDs. The influence of critical dimension variability on the SET functionality and options to reduce such deviations are discussed. We finally demonstrate the reliable formation of Si quantum dots with diameters of less than 3 nm in the oxide layer of a stacked Si/SiO2/Si NP of 10 nm diameter, with tunnelling distances of about 1 nm between the Si ND and the neighboured Si regions forming drain and source of the SET.

As a neuromodulator, the neurotransmitter acetylcholine plays an important role in cognitive, mood, locomotor, sleep/wake, and olfactory functions. In the pathophysiology of
most neurodegenerative diseases, such as Alzheimer disease (AD) or Lewy body disorder (LBD), cholinergic receptors, transporters, or enzymes are involved and relevant as
imaging targets. The aim of this review is to summarize current knowledge on PET imaging of cholinergic neurotransmission in neurodegenerative diseases. For PET imaging
of presynaptic vesicular acetylcholine transporters (VAChT), (-)-18F-fluoroethoxybenzovesamicol (18F-FEOBV) was the first PET ligand that could be successfully translated
to clinical application. Since then, the number of 18F-FEOBV PET investigations on patients with AD or LBD has grown rapidly and provided novel, important findings
concerning the pathophysiology of AD and LBD. Regarding the α4β2 nicotinic acetylcholine receptors (nAChRs), various second-generation PET ligands, such as 18F-nifene,
18F-AZAN, 18F-XTRA, (-)-18F-flubatine, and (+)-18F-flubatine, were developed and successfully translated to human application. In neurodegenerative diseases such as AD
and LBD, PET imaging of α4β2 nAChRs is of special value for monitoring disease progression and drugs directed to α4β2 nAChRs. For PET of α7 nAChR, 18F-ASEM and
11C-MeQAA were successfully applied in mild cognitive impairment and AD, respectively. The highest potential for α7 nAChR PET is seen in staging, in evaluating disease
progression, and in therapy monitoring. PET of selective muscarinic acetylcholine receptors (mAChRs) is still in an early stage, as the development of subtype-selective
radioligands is complicated. Promising radioligands to image mAChR subtypes M1 (11C-LSN3172176), M2 (18F-FP-TZTP), and M4 (11C-MK-6884) were developed and
successfully translated to humans. PET imaging of mAChRs is relevant for the assessment and monitoring of therapies in AD and LBD. PET of acetylcholine esterase activity
has been investigated since the 1990s. Many PET studies with 11C-PMP and 11C-MP4A demonstrated cortical cholinergic dysfunction in dementia associated with AD and
LBD. Recent studies indicated a solid relationship between subcortical and cortical cholinergic dysfunction and noncognitive dysfunctions such as balance and gait in LBD.
Taken together, PET of distinct components of cholinergic neurotransmission is of great interest for diagnosis, disease monitoring, and therapy monitoring and to gain insight
into the pathophysiology of different neurodegenerative disorders.

This study proposes a novel non-intrusive approach for measuring axial liquid dispersion coefficients in trickle-bed reactors. The approach is based on the flow modulation technique (FMT), which replaces traditional tracer substance injections with a marginal sinusoidal modulation superimposed on the liquid inlet flow. The modulation causes a sinusoidal variation of the liquid holdup in time, i.e. liquid holdup wave. Downstream the inlet, the holdup wave gets damped in amplitude and shifted in phase due to dispersion. Amplitude damping and phase shift are experimentally measured and related to the value of the axial dispersion coefficient using a one-dimensional dispersion model. Recently, the flow modulation has been applied to investigate the axial gas dispersion coefficient in bubble columns. In this study, the approach is adapted to measure liquid dispersion in co-current gas-liquid trickle-bed reactors. In addition, the consequences of the assumptions requested by the axial dispersion model are discussed. Furthermore, the impact of the experimental flow modulation parameters on sensitivity and uncertainty of the dispersion coefficient is analyzed.

The knowledge of the tray efficiency value is crucial for a correct design of tray columns [1]. In the last decades, several models have been developed for predicting the tray efficiency value, given the point efficiency. Validation of these models requires determining both tray and point efficiency experimentally.
The tray efficiencies are mostly determined by sampling the incoming and exiting streams of liquid and gas over the tray. On the contrary, experimentally determining point efficiencies is technically challenging and thus, their value is often derived from correlations or small-scale experiments (e.g. Oldershaw columns). Only few studies on the experimental determination of point efficiencies on large-scale distillation trays exist (e.g. [2], [3]). The physical systems used in these studies pose several technical restrictions and safety concerns. For these reasons, a setup designed ad hoc for point efficiency studies is mostly needed.
Recently Marchini et al. [4] proposed the stripping of isobutyl acetate from an aqueous solution using air as a physical system,which was proven to offer several advantages over the traditional ones and to be readily integrated into existing cold fluid air/water mockups without any major modification. The authors also showed how the tray-to-point efficiency ratio can be determined based on the liquid concentration distribution on the tray, accounting for liquid mixing phenomena in both the axial and transversal directions.
In this study, the tray and point efficiency values of an 800 mm dia. distillation sieve tray were determined at different gas and liquid flow rates by sampling the liquid at different deck locations for subsequent UV-spectroscopy, obtaining the liquid concentration distribution (Figure 1).

When assessing the long-term safety of a nuclear waste repository, the interactions of dissolved long-lived radionuclides, such as the actinide neptunium, with corroded phases in the near-field of the repository have to be considered. Zirconia (ZrO₂) is the main corrosion product of the zircaloy cladding material of nuclear fuel rods and can constitute a first barrier against the release of mobilized radionuclides into the environment.
To gain a detailed understanding of the Np(V) sorption processes at the zirconia‒water interface, a comprehensive multimethod approach was pursued. Molecular level information about the Np(V) surface species were derived by in situ Attenuated Total Reflection Fourier Transform Infrared Spectroscopy (ATR FT-IR) and Extended X-ray Absorption Fine Structure Spectroscopy (EXAFS). The Np L₃-absorption edge (17,610 eV) is commonly used for EXAFS investigations of neptunium. However, the Zr K absorption edge (17,998 eV) is close in energy to the Np L₃-edge, reducing the k-range that can be evaluated. Since attempts to use the Np L₂-edge (21,600 eV) with an energy above the Zr K-edge were not successful, the Np L₃-edge EXAFS spectra had to be used to gain information about the molecular environment of the sorbed Np(V) surface species. The short Np-Zr distance of approximately 3.6 Å derived from EXAFS spectra revealed the predominant formation of bidentate inner-sphere Np(V) surface complexes. ATR FT-IR experiments were conducted at different pH values and a shift of the asymmetric stretching vibration of Np(V) (𝜈₃(NpO₂⁺) towards lower energies was observed at acidic pH, revealing the interactions between Np(V) and ZrO₂. Furthermore, the sorption process was only slightly reversible, also indicating the formation of Np(V) inner-sphere complexes. However, with increasing pH, vibrational surface modes of the ZrO₂ matrix appeared, which were overlapping with Np(V) stretching frequency and impeding the investigation of the pH-dependent surface speciation of Np(V).
Batch sorption experiments (varying ionic strength, Np(V) concentration, and solid-to-liquid ratio (m/V)) as well as a sorption isotherm experiment at pH 6 were conducted to study the sorption processes of the Np(V)‒ZrO₂ system on the macroscopic scale. The sorption of Np(V) was independent of ionic strength, also indicating the formation of Np(V) inner-sphere surface complexes. This was supported by zeta potential measurements in the presence of neptunium, where a shift to higher pH values of the isoelectric point of the neat ZrO₂ was observed. With increasing m/V the Np(V) sorption edge was shifted towards lower pH values, indicating the presence of different kinds of sorption sites, which was also deduced from the shape of the sorption isotherm.
Reliable information about the number and denticity of surface species obtained by spectroscopic and macroscopic investigations enable modeling approaches such as surface complexation modeling (SCM) to be robust. The results derived by SCM will in turn contribute to a more reliable prediction of the environmental fate of neptunium.

For a safety assessment of a repository for nuclear waste, the interactions of actinides with corroded phases in the near-field must be taken into account. Most commercial fission reactors use uranium-based fuels and the spent nuclear fuel still contains approximately 95 % of uranium, making it the largest fraction of the spent nuclear fuel by mass. Zirconia (ZrO₂) is the main corrosion product of the zircaloy cladding material of nuclear fuel rods and can act as a first barrier against the release of mobilized radionuclides from the spent nuclear fuel into the environment. Furthermore, the complexation of dissolved radionuclides with common inorganic ligands, such as carbonate, in the groundwater can have a significant influence on the formation and structure of actinide surface species and thus their mobility in the environment.
In situ Attenuated Total Reflection Fourier Transform Infrared Spectroscopy (ATR FT-IR) and Extended X-ray Absorption Fine Structure Spectroscopy (EXAFS) were applied to investigate the U(VI) speciation at the ZrO₂-water interface. A pH-dependent speciation of U(VI) at the zirconia surface could be observed under inert gas conditions with EXAFS and the preliminary results indicated the presence of two inner-sphere U(VI) surface species with different structural environments. The EXAFS results can be compared to the literature results of Lomenech et al., where also two U(VI) surface species on the ZrO₂ surface were observed (a tridentate U(VI) surface species at pH 3 and a bidentate surface species at higher pH) [1,2].
The sorption of U(VI) onto ZrO₂ under inert gas conditions was also studied with ATR FT-IR at pH 3.5 and 5.5 and a pH-dependent U(VI) speciation was observed, supporting the findings from the EXAFS investigations. The observed red shift of the asymmetric stretching vibration of the free uranyl aqua ion (𝜈₃(UO₂²⁺)) in the presence of ZrO₂ at pH 5.5 was due to the U(VI)‒ZrO₂ interactions. At a lower pH of 3.5 a second U(VI) surface species with a less pronounced red shift of the ν₃ vibration was identified.
A pH-dependence of the sorption of atmospheric carbonate on the zirconia surface was observed and a spectral splitting (Δ𝜈) of approximately 200 cm⁻¹ of the symmetric and asymmetric stretching vibration modes indicated the presence of bidentate bound carbonate species on the surface. The U(VI) sorption onto zirconia pre-equilibrated with atmospheric carbonate was also studied at pH 5.5 and 3.5. Compared to the experiments conducted under inert gas conditions, the red shift of the ν₃ mode of U(VI) at pH 5.5 was more pronounced in the presence of carbonate, indicating an influence of carbonate on the formed U(VI) surface species. In addition, changes in the frequency of the asymmetric and symmetric stretching vibrations of carbonate sorbed to the zirconia surface were observed in the presence of U(VI), also hinting towards structural changes in the surface species.
EXAFS and ATR FT-IR investigations provided valuable structural information about the formed U(VI) sorption species on the ZrO₂ surface in the presence and absence of carbonate. The improved molecular level understanding of such sorption processes will enable more reliable predictions of the environmental fate of U(VI). Such results will be complemented with batch sorption experiments as well as thermodynamic surface complexation modeling.

[1] Lomenech, C. et al. (2003) Radiochim. Acta 91(8), 453-461.
[2] Lomenech, C. et al. (2003) J. Colloid Interface Sci. 261(2), 221-232.

Soft actuators are required to deform, fold, or unfold in order to interact with their surroundings.[1] One strategy to achieve the movement of mechanically soft systems is the use of magnetic fields for untethered actuation. Flexible magnetic composites have been demonstrated as functional grippers, rollers, and walkers upon applied external magnetic fields.[2] Being controlled with electromagnetic coils, magnetic actuators can profit from high-speed actuation to quickly respond to their environment.[3]

The development of an appropriate sensory tracking system for soft actuators is a research topic with open challenges. Light, conformal, and mechanically imperceptible sensing systems are to be developed to be compatible with soft actuators. In this work, we present flexible magnetosensitive electronic skin which relies on thin-film magnetic field sensors to enable onboard folding control of origami-like soft actuators. The flexible electronic skin consists of thin film giant magnetoresistive GMR and Hall effect sensors that are used to measure the magnetization state of the actuator, the applied magnetic fields, and the completeness of the bending process. The resulting intelligent material is mechanically designed to fold even when the flexible magnetic skin is attached to the soft actuator.[4]

The magnetic origami actuators are made of thin DiAPLEX foils, a shape memory polymer, with embedded NdFeB particles. Such composite can be used to achieve magnetically induced motion using magnetic fields and a directed light source to increase locally the temperature. We experimentally found the best thickness (60 µm) and concentration (40 NdFeB wt%) parameters to achieve magnetic folds.[4]

The integration of magnetic soft actuators with e-skins allowed self-guided assembly of the origami foils. We showed two case studies showing that this approach is useful for assembling boxes and boat-like origami shapes. This integration process was monitored, followed, and controlled by the output of the laminated sensors. [4]

[1] A. Miriyev, et al. Nat. Commun. 8, 596 (2017)

[2] S. Wu, et al. Multifunct. Mater. 3, 042003 (2020)

[3] X. Wang, et al. Commun. Matter. 1, 67 (2020)

[4] M. Ha, et al. *Adv. Mater. 33, 2008751 (2021)

The development of functional printable materials enables the production of electronic components in unconventional materials and different form factors[1]. Here, we show magnetically sensitive inks/pastes based on magnetoresistive powder that can be printed via stencil, dispenser, or screen printing. We employ bismuth microparticles[2] as well as [Co/Cu], [Py/Cu],[3] and permalloy [4] flakes showing giant, anisotropic, or non-saturating large magnetoresistance, respectively.

We demonstrate that magnetic field sensors based on various types of magnetoresistive flakes can be printed onto rigid, flexible, and deformable substrates. We employed block-copolymers and elastic binders to enable mechanical resilience of these sensors: they can withstand bending down to 16 µm, 100% of stretching, and bending for hundreds of cycles without losing functionality.[3]

Additionally, by automatizing the dispenser printing process of bismuth-based pastes, we demonstrate the production of fully printed magnetic field sensors. The use of a micro-optically optimized high-power diode laser array provided a versatile approach for selective sintering of sensors over flexible foils in areas exceeding several square centimeters. In this work we experimentally confirm that such sensors retain their non-saturating magnetoresistive performance (MR = 146%) in high field conditions, allowing operation above 5 T. [2]

Our printed magnetic field sensors can be used to create interfaces that are responsive to magnetic fields through remote human input. Being flexible, they can be laminated on the skin, or stuck onto any object, from a desk to a house wall. We demonstrate the capabilities of printed magnetic field sensors to work as an interface to navigate through digital maps, as input panels for smart home applications, and as interactive wallpapers.

[1] A. Kamyshny, et al. 1905279 (2020) *Chem. Soc. Rev.* **48**, 1712 (2019)

[2] E.S. Oliveros-Mata, et al. *Appl. Phys. A* **127,** 280 (2021)

[3] M. Ha, et al. *Adv. Mater.* **33,** 2005521 (2021)

[4] E.S. Oliveros‐Mata, E. S., C. Voigt, et al. *Adv. Mater. Technol.* 2200227 (2022)

The study of habitat selection is a foundational component of basic and applied animal ecology. Today, habitat selection in mammals is primarily studied using resource selection functions, a class of models that uses logistic regression to compare “used” to “available” habitat. However, these models have several statistical problems, including rampant pseudoreplication from failing to account for autocorrelation in modern animal movement data, no clear guidelines for sampling available habitat, and large amounts of numerical error from sampling too few available points. These problems are widely acknowledged but have no generally accepted solutions, so we propose three new methods for addressing them: likelihood weighting, Gaussian availability sampling, and numerical convergence checks. We demonstrate the practical advantages of these methods over conventional approaches using simulations and empirical data on a water mongoose (Atilax paludinosus), a caracal (Caracal caracal), and a serval (Leptailurus serval), and briefly demonstrate how to apply our methods to animal tracking data using the ‘ctmm’ R package. Broad uptake of these methods could substantially improve our estimates of habitat selection in mammals.

Objective. Local magnetic resonance (MR) signal loss was previously observed during proton beam
irradiation of free-floating water phantoms at ambient temperature using a research prototype in-
beam magnetic resonance imaging (MRI) scanner. The emergence of this MR signal loss was
hypothesised to be dependent on beam-induced convection. The aim of this study was therefore to
unravel whether physical conditions allowing the development of convection must prevail for the
beam-induced MRI signatures to emerge. Approach. The convection dependence of MRI magnitude
signal-based proton beam visualisation was investigated in combined irradiation and imaging
experiments using a gradient echo (GE)-based time-of-flight (ToF) angiography pulse sequence,
which was first tested for its suitability for proton beam visualisation in free-floating water phantoms
at ambient temperature. Subsequently, buoyant convection was selectively suppressed in water
phantoms using either mechanical barriers or temperature control of water expansivity. The
underlying contrast mechanism was further assessed using sagittal imaging and variation of T1
relaxation time-weighting. Main results. In the absence of convection-driven water flow, weak beam-
induced MR signal changes occurred, whereas strong changes did occur when convection was not
mechanically or thermally inhibited. Moreover, the degree of signal loss was found to change with the
variation of T1-weighting. Consequently, beam-induced MR signal loss in free-floating water
phantoms at ambient temperature does not exclusively originate from buoyant convection, but is
caused by local composite effects of beam-induced motion and radiation chemistry resulting in a local
change in the water T1 relaxation time. Significance. The identification of ToF angiography sequence-
based proton beam visualisation in water phantoms to result from composite effects of beam-induced
motion and radiation chemistry represents the starting point for the future elucidation of the currently
unexplained motion-based MRI contrast mechanism and the identification of the proton beam-
induced material change causing T1 relaxation time lengthening.

While Density Functional Theory (DFT) is the most common tool for the investigation of materials under extreme conditions, its scaling behavior with respect to both system size and temperature makes large scale simulations challenging. Yet, progress in this regard would enable accurate modeling of planetary interiors or radiation damage in fusion reactor walls.
One possible route to alleviate these scaling problems is through the use of surrogate models, i.e., machine-learning models. These are trained on DFT data and are able to reproduce DFT observables at comparable accuracy, but negligible computational cost.
In order to actually be useful for such investigations, existing models need to be able to work across length scales and be transferable within desired temperature ranges. Here we show how models based on local mappings of electronic structure information [1], implemented in the Materials Learning Algorithms (MALA) package [2] can be trained on small number of atoms and select temperatures, yet perform accurately when used to make predictions for extended systems within a range of temperatures.

X-ray Absorption Near-Edge Structure (XANES) in the High-Energy-Resolution Fluorescence Detected Mode (HERFD) is a very powerful technique for actinide systems. The M4,5 edges are of particular interest because they probe directly 5f states. However, before the advent of HERFD they were scarcely used because the large core-hole lifetime broadening results in broad and featureless spectra. With the improved resolution of the HERFD mode, the characterristic edge shift of different oxidation states is well resolved and several spectral features are observed in M4,5 HERFD XANES of actinides. The richness of physicochemical information coded in the spectra are hard to extract due to the complexity of XANES interpretaion and drawing conclusions on the system under study is not trivial.

In this regards, spectral calculations are fundamental for a correct interpretation. Calculating HERFD XANES on actinide systems is however particularly challenging. Relativistic effects, spin-orbit and interelectronic interactions and the influence of the atomic environment are all relevant and need to be considered in calculations. In last years, despite several approaches has been used with promising results, we still miss a theoretical framework that can address the complexity of M4,5 HERFD XANES on actinide systems.

In this presentation we will report the results we obtained with a DFT-based approach on the M4 edge of U6+ systems. Our results will be compared with works done with other approaches in order to give an overview of the level of agreement with experimental data that can be reached today. Special emphasis will be given to the investigation of covalency of 5f states.

Micro- and nano-sized conical structures possess specific magnetic, superhydrophobic and electrocatalytic properties and are therefore attractive for numerous applications. Among the various methods of manufacturing such structured layers, electrodeposition appears a simple and inexpensive method. Beside the use of capping agents, the application of magnetic fields could support the local growth of cones on a non-templated planar electrode.
This dissertation investigates electrodeposition at conically structured metal layers in external magnetic fields. Depending on the direction and the intensity of the magnetic field, the Lorentz force and the magnetic gradient force can generate electrolyte flow and bring electrolyte enriched with metal ions towards the cone tips. As a result, the local deposition rate is increased and conical growth is promoted. In order to obtain a basic understanding of the magnetic field effects, systematic numerical and theoretical investigations are performed for electrodeposition at mm-sized cones of different materials, shapes and arrangements under different electrochemical and magnetic conditions. If a uniform external magnetic field is oriented parallel to the cone axis, the magnetic gradient force enabled by the magnetization of ferromagnetic cones provides a strong support for conical growth, thereby often dominating over the Lorentz force and the buoyancy force arising from electrode reactions. This supporting effect is only slightly mitigated when neighboring cones are getting closer. The numerical results shown are validated by experimental data for different configurations and deposition parameters.
In order to explore the prospects of magnetic fields to enhance the growth of smaller, micro- and nanometer sized conical structures, scaling laws of the local flows driven by the magnetic forces are derived numerically and confirmed analytically for shrinking cone sizes. Although the magnetic gradient force can generate a beneficial flow at ferromagnetic cones, the small flow region and the nearly constant thickness of the concentration boundary layer limit the support of the magnetic field. Enhancements of the structuring effect are observed for pulsed deposition and, despite only moderately, at higher magnetic field intensities. Furthermore, a simplified modeling approach is developed to simulate the growth mechanism of nano-cones with respect to the influence of capping agents.
Experimental results of the electrodeposition of Ni cones in magnetic fields obtained by partners in Krakow are analyzed by performing simulations of both the global cell flow and the local flows generated by magnetic fields of different orientations. This two-step approach provides an interpretation of the experimental results, and gives a deeper insight on how the capping agent influences the local growth.
Finally, the impact of the hydrogen side reaction on the electrodeposition in magnetic fields is considered. The numerical results indicate that hydrogen bubbles sitting at the cone tips may damp conical growth, while the magnetic-field-driven flow imposes a weak stabilizing force on the bubble.

Nonlinear THz spectroscopy of two-dimensional systems (pump-probe in graphene, with and without magnetic field, dressed microcavity polaritons).

Systems of self-propelled particles exhibit self-organized collective behavior that leads to the formation of complex spatio-temporal patterns that can be observed all over nature — from the active self-assembly of microtubules in cells through the action of kinesin motor proteins, to flocking birds. Because of their abundance, the question of how these rich macroscopic structures emerge from the microscopic interactions of their constituents remains of central interest. While there exist several hydrodynamic theories that help better understand the physical mechanisms, it is often difficult to determine which local microscopic interactions shape and regulate self-organized structures in active particle systems. Using a combination of unsupervised clustering algorithms and sparsity-promoting inference, we learn from data dominant force balance laws that locally drive the emergence of macroscopic patterns in active particle systems. We consider a classic hydrodynamic model of self-propelled particle systems that hosts solutions composed of spatiotemporal patterns like asters and propagating stripes. We show that 1) propagating stripes are formed by local alignment interactions and driven by gradients in polarization density and 2) steady-state asters are shaped by a mechanism of splay-induced negative compressibility arising from strong particle interactions. These data-driven discoveries are in excellent agreement with analytical predictions. We therefore believe that the presented data-driven strategy, in combination with physical modeling, can help our mechanistic understanding of active material systems as well as the design of biomimetic materials.

In-beam MRI has recently proven capable of visualising proton beams in liquid-filled
phantoms based on beam-induced local MR signal amplitude loss. This holds promise for on-
line beam range verification and dosimetric as well as geometric quality assurance for hybrid
MRI-proton therapy systems currently under development. The purpose of this study was
firstly to determine whether, in addition to MR signal amplitude loss, the MRI phase signal is
affected by the proton beam and secondly, to test whether these changes in MRI signals are
triggered by beam-induced convection.

Background and purpose: Proton therapy has become a popular treatment modality in the field of radiooncology due to higher spatial dose conformity compared to conventional radiotherapy, which holds the potential to spare normal tissue. Nevertheless, unresolved research questions, such as the much debated relative biological effectiveness (RBE) of protons, call for preclinical research, especially regarding in vivo studies. To mimic clinical workflows, high-precision small animal irradiation setups with image-guidance are needed.

Material and methods: A preclinical experimental setup for small animal brain irradiation using proton radiographies was established to perform planning, repositioning, and irradiation of mice. The image quality of proton radiographies was optimized regarding the resolution, contrast-to-noise ratio (CNR), and minimal dose deposition in the animal. Subsequently, proof-of-concept histological analysis was conducted by staining for DNA double-strand breaks that were then correlated to the delivered dose.

Results: The developed setup and workflow allow precise brain irradiation with a lateral target positioning accuracy of <0.26mm for in vivo experiments at minimal imaging dose of <23mGy per mouse. The custom-made software for image registration enables the fast and precise animal positioning at the beam with low observer-variability. DNA damage staining validated the successful positioning and irradiation of the mouse hippocampus.

Conclusion: Proton radiography enables fast and effective high-precision lateral alignment of proton beam and target volume in mouse irradiation experiments with limited dose exposure. In the future, this will enable irradiation of larger animal cohorts as well as fractionated proton irradiation.

In this work, an approach is proposed to study the influence of floating conditions on the fluid flow behavior of separation columns. A structured packing (Mellapak 250Y) air dehumidifier was embarked on a hexapod ship motion emulator with six-degree-of-freedom motions to mimic swell. A novel flow imaging sensor has been developed to visualize the flow morphology dynamics of triethylene glycol evolving on the corrugated sheets of packings. Furthermore, a numerical model was developed based on the hydrodynamic analogy concept to evaluate the separation performance using experimentally observed flow patterns. In our contribution, we describe the flow imaging sensor design as well as the impact of tilt on efficiency losses in comparison with the conventional upright stationary column.

Environmental and economic constraints for oil and gas production necessitate the development of cost-effective operating facilities in the modern offshore industry. For this reason, floating production systems are increasingly used to operate oil and gas fields in deepwater locations, whereby high submarine pipeline expenditures of fixed offshore platforms are eliminated. Apart from economic advantages, floating production systems maintain a safe operation and continuous production under severe ocean conditions, i.e. cyclones, huge waves and floating icebergs. Whilst traditional fossil energy sources are continuously losing their dominance, liquefied natural gas (LNG) is gaining popularity in the energy market owing to the comparatively lower greenhouse gas emissions. For LNG production, Floating Production Storage and Offloading (FPSO) units combine the feature of onshore LNG plants and that of storage tankers in a single large marine vessel. Thus, the number of FPSOs for LNG production has been growing in the offshore industry. The design principles for land-based process units cannot be directly applied to FPSO topside equipment because of wind-generated wave effects. Separation columns are more susceptible to the motion impact than most of the onboard process equipment, and consequent product quality losses represent the main concern.
Separation columns with structured packings are mostly used on floating platforms due to their low pressure drop, high capacity and performance. To study the dynamics of the flow morphology in the packing and the corresponding mass transfer performance, a structured packing column is embarked on a hexapod motion simulator, which mimics the six-degree-of-freedom ship motion (cf. Fig. 1). The process of air dehumidification by triethylene glycol (TEG) solutions is used as an example. A novel flow imaging sensor was developed to visualize the flow morphology dynamics evolving on the corrugated sheets of the structured packing (Fig. 2). The sensor detects most relevant morphologies, i.e. unwetted, partially and fully wetted channels and their corresponding film thicknesses on the packing sheets for the tilted and moving column allowing a comparison with the vertically oriented configuration.
At a later step, along with the fluid dynamics, the separation performance of air dehumidification and the liquid desiccant regeneration processes will be evaluated. The experimental data will be used to develop a new modelling approach for floating structured packing columns based on hydrodynamic analogies between complex flow patterns in real columns and simplified fluid-dynamic elements.

Power cycles based on supercritical carbon dioxide (sCO2) promise higher thermal efficiencies and more compact components than conventional technologies. Within the CARBOSOLA project, funded by the German Federal Ministry for Economic Affairs and Energy, a large-scale experimental facility is being set up by a consortium of scientific and industrial partners to actively contribute to the development of sCO2 technology. The first expansion stage provides a circulation of the sCO2 flow without expansion devices in the test loop. Thereby the compressor is intended to compensate for pressure losses and consequently for low pressure differences. In addition to that, a preferably wide operating range, regarding temperature and pressure, shall provide a high degree of flexibility of the test rig.
This work presents the design optimization of the impeller aiming at a wide operating range in compliance with the boundary conditions set for the test rig and the use of sCO2. For this purpose, a hybrid approach is used, combining parametric three-dimensional modeling with a one-dimensional performance criterion for operating range estimation. A large number of impeller designs have been simulated numerically within an optimization procedure using a genetic algorithm. On this basis, several designs have been selected and compared against each other. The evaluation includes sets of performance lines and the validation of the one-dimensional criterion used for optimization.

The safe disposal of high-level radioactive waste represents a significant scientific and societal challenge. According to geological, geochemical, and geophysical properties, clay formations represent a suitable host rock for the long-term storage of this waste. However, for a comprehensive safety assessment, the influence of naturally occurring microorganisms in clay rock and in the backfill material bentonite must be taken into account.
Desulfosporosinus species play a crucial role in the community of sulfate-reducing bacteria present in clay rock and bentonite.[1,2] Desulfosporosinus hippei DSM 8344T is a close relative of the isolated species and was originally found in permafrost soils.[3] Desulfitobacterium sp. G1-2 has been isolated from bentonite samples and is an important representative of iron-reducing bacteria. As members of the microbial community from deep geological layers, these strains were selected to get a more profound knowledge about their interactions with U(VI).
During time-dependent experiments in bicarbonate buffer (30 mM, 100 µM U(VI)), Desulfitobacterium sp. G1-2 showed a removal of up to 80% within 5 days. UV/Vis studies of the dissolved cell pellets verified the formation of U(IV) during the process.
In contrast to these findings, Desulfosporosinus hippei DSM 8344T was not able to reduce U(VI) in the presence of bicarbonate. Therefore, experiments in artificial Opalinus Clay pore water [4] (100 µM U(VI), pH 5.5) were conducted. Determinations of the U concentrations showed a removal of up to 80% of the radionuclide from the supernatants within only 48 h. UV/Vis studies of the dissolved cell pellets provided clear proof of a partially reduction of U(VI) to U(IV), although bands of U(VI) were also still observable. These findings propose a combined association-reduction process as a possible interaction mechanism for this microorganism.
TEM images combined with EDX analysis revealed the presence of two different U-containing aggregates inside cells of Desulfitobacterium sp. G1-2. Furthermore, cells of Desulfosporosinus hippei DSM 8344T released membrane vesicles as a possible defense mechanism against encrustation by U precipitates on the cell surface. However, cells showed almost no uptake of U.
In this study, different analytical methods were used to better understand the U(VI) reduction by sulfate- and iron-reducing bacteria. Significant differences in the occurring mechanisms were evident between both microorganisms, highlighting the importance of studies on the U(VI) interactions of different microorganisms present in clay rock. Moreover, these results contribute to a safety concept for a nuclear repository in clay formations and for final disposal sites using bentonite as backfill material.

References:

[1] Bagnoud et al. (2016) Nat. Commun 7, 1–10.
[2] Matschiavelli et al. (2019) Environ. Sci. Technol. 53, 10514–10524.
[3] Vatsurina et al. (2008) Int. J. Syst. Evol. Microbiol. 58, 1228–1232.
[4] Wersin et al. (2011) Appl. Geochemistry 26, 931–953.

Air pollution caused by particle resuspension is a growing public health problem in many cities. Pollen and anthropogenic pollutants, such as heavy metal particles and micro-plastics debris, settle onto urban ground surfaces. Prolonged urban heat waves are propitious for heavy and continuous deposition. Particles in the submillimeter size range eventually resuspend by urban winds within seconds, may be inhaled, cause allergic reactions and escape the city's boundaries. Here, the resuspension and subsequent dispersion of generic particles ranging from 10 to 100 μm in size are simulated. The city area “Bayerischer Bahnhof” in Leipzig, Germany, has been chosen as a practical example. To track the resuspended particles, a Lagrangian model is used. Taking advantage of graphics processing unit, turbulent flow simulations at different wind speeds are performed in almost real time. The results show that particle resuspension starts, when the inlet wind speed beyond the canopy, that is at a height of 40 m, exceeds 7 m/s. At wind speed beyond 14 m/s, resuspension occurs in almost all city parts. At moderate wind speed, high-risk areas are identified. The effect of green infrastructures on both the flow field and particle resuspension is also investigated.

Aerosolpartikel liegen in nahezu allen Gasen vor. Die Abscheidung dieser Partikel ist unter anderem bei der Reinigung von Luft von Feinstaub und Viren relevant. Auch in der Verfahrenstechnik reagieren beispielsweise Gase mit Feststoffen, wie bei der Gasphasenpolymerisation. Für Partikel im Größenbereich von 0,1 – 10 µm sind bisher aufgrund zu weniger empirischer Daten keine zuverlässigen Vorhersagen der Prozesse möglich.
In diesem Beitrag werden Messungen der Innenströmung einer Blase in verschiedenen, mit Wasser durchströmten Rohren gezeigt. In einem Rohr mit konstantem Durchmesser ist ein langgezogener Wirbel sichtbar. Zur Beeinflussung der Blaseninnenströmung ist in einem Rohr eine Verjüngung eingebracht. Die Verjüngung erzeugt in der Blase einen zweiten Wirbel, welcher die gleiche Rotationsrichtung aufweist. Im Berührungsbereich zwischen beiden Wirbeln treffen entgegengesetzte Strömungen aufeinander.

XANES, with its high sensitivity to the oxidation state and the local structure, is a very powerful tool to investigate actinide-based materials. The use of the High-Energy-Resolution Fluores-cence-Detected (HERFD) mode opened new perspective in this field. By reducing the core-hole lifetime broadening, HERFD allows a relevant gain in resolution at the L3 edge and a major im-provement for M4,5 edges.
The information contained in a XANES spectrum are often hard to extract and therefore need the support of theory. However, calculations of actinide materials made complex by the compa-rable strength of intra-electronic interactions, spin-orbit and influence of the local environment. Efforts are ongoing to take all the relevant physics into account, however today none of the the-oretical framework used in XANES calculations can account for all relevant interactions over a large cluster of atoms.
If we do not yet have a unique theoretical framework that can be applied to all actinide systems, we can still select the theory that is more adapted to specific cases. In this contribution we will present progresses in the interpretation of XANES of actinide systems obtained by using the DFT–based code FDMNES [1]. Results at the L3 and M4,5 edges on Th4+ and U6+ systems will be presented [2-4]. These systems, where the intra-electronic interactions are less relevant due to the absence of 5f valence electrons, are particularly suited to investigate the importance of the local environment on the spectral shape.
Our results endorse the use of HERFD XANES coupled with DFT-based calculations to investi-gate complex actinide-containing systems.

Nature teaches that nanostructured surfaces show a variety of beneficial macroscopic effects. The laser texturing of metal surfaces allows the fast, defined, and adjustable large-area nano- and micro surface structuring using ultrashort laser pulses. Such hierarchical structures comprising of determined micro patterns and self-organized nanostructures allow the customization of metal surface properties for applications in accelerators, optics, and fluidics. Here, the laser exposure of superhydrophobic SSt can cause a localized modification of the surface tension which enables the guiding and pining of water droplets which was studied using high-speed optical imaging.
The laser-induced micro- and nano structuring and the chemical modification of the metal surfaces allows the fast and defined adjustment of the macroscopic properties of metals with manifold applications.

In this review, the application of light ion irradiation is discussed for tailoring novel functional materials and for improving the performance in SiC or Si based electrical power devices. The deep traps and electronic disorder produced by light ion irradiation can modify the electrical, magnetic, and optical properties of films (e.g., dilute ferromagnetic semiconductors and topological materials). Additionally, benefiting from the high reproducibility, precise manipulation of functional depth and density of defects, as well as the flexible patternability, the helium or proton ion irradiation has been successfully employed in improving the dynamic performance of SiC and Si based PiN diode power devices by reducing their majority carrier lifetime, although the static performance is sacrificed due to deep level traps. Such a trade-off has been regarded as the key point to compromise the static and dynamic performances of power devices. As a result, herein the light ion irradiation is highlighted in both exploring new physics and optimizing the performance in functional materials and electrical devices.

Dielectric thin films having high permittivity (high-k) and low dielectric loss is essential for developing high performance capacitive devices like metal oxide field effect transistor or thin film transistor. Ga ion implantation performed on Cu-doped ZnO film fabricated by pulsed laser deposition with optimized doping concentrations and post-implantation annealing yielded film having high permittivity and low dielectric loss (ε = 87 and tan δ = 0.17 at the frequency of 1 kHz). Moreover, the permittivity exhibits good stability over a wide range of frequency from 20 Hz to 10 MHz. The high-k film was characterized by detailed dielectric studies, including frequency dependence of permittivity and dielectric loss, complex electrical modulus analysis, impedance spectroscopy and ac conductivity. The enhancement of the permittivity was attributed to the correlated potential barrier hopping of electrons between the neighboring acceptor-donor defect complex states in the band gap created by the co-doping, thus acting as electric dipoles polarizing the film. This work opens up future possibility for ‘dielectric engineering’. The three-dimensional dielectric spatial profile can be controlled via the selective area ion implantation with the depth controlled by the ion implantation energy.

The modulation of structural color through various methods has attracted considerable attention. Herein, a new modulation method for the structural colors in all-dielectric photonic crystals (PCs) using energetic ion beams is proposed. One type of periodic PC and two different defective PCs were experimentally investigated. Under carbon-ion irradiation, the color variation primarily originated from the blue shift of the optical spectra. The varying degrees of both the reflection and transmission structural colors mainly depended on the carbon-ion fluences. Such nanostructures are promising for tunable color filters and double-sided chromatic displays based on PCs.

Two-dimensional conjugated metal–organic frameworks (2D c-MOFs) have emerged as a new generation of conducting MOFs for electronics. However, controlled synthesis of thin-film samples with high crystallinity and defined layer orientation, which is beneficial for achieving high-performance devices and reliable structure–property relationship, has remained a challenge. Here, we develop a surfactant-directed two-step synthesis of layered 2D c-MOF films based on benzene and triphenylene ligands linked by copper-bis(diimino) complexes (HIB-Cu and HITP-Cu, respectively). The achieved layered 2D c-MOF films are featured as free-standing, in-plane oriented, and polycrystalline films with domain size up to ∼8000 nm2 and a tunable thickness in the range of 8–340 nm. Benefiting from the intrinsic electrical conductivity and quasi-one-dimensional pore channels, a HIB-Cu film based chemiresistive sensor is constructed, displaying effective humidity sensing with a response as fast as ∼21 s, superior to the reported MOF-powder-based chemiresistive sensors (in the orders of minutes).

In this work, carbon ion irradiation and precise diamond blade dicing are applied for Nd:GdCOB ridge waveguide fabrication. The propagation properties of the fabricated Nd:GdCOB waveguides are investigated through experiments and theoretical analysis. The micro-Raman analysis reveals that the lattice of Nd:GdCOB crystal expands during the irradiation process. The micro-second harmonic spectroscopic analysis suggests that the original nonlinear properties of the Nd:GdCOB crystal are greatly enhanced within the waveguide volume. Under a pulsed 1064-nm laser pumping, second harmonic generation (SHG) at 532 nm have been achieved in the fabricated waveguides. The maximum SHG conversion efficiencies are determined to be ~8.32%W^-1 and ~22.36%W^-1 for planar and ridge waveguides, respectively.

Single-crystal europium iron garnet (EuIG) thin films were epitaxially grown on gadolinium gallium garnet (GGG)(001) substrates using off-axis sputtering and showed strain-induced perpendicular magnetic anisotropy (PMA). By varying the sputtering conditions, we have tuned the europium/iron (Eu/Fe) composition ratios in the films to tailor the film strains. The films exhibited an extremely smooth, particle-free surface with a root-mean-square roughness as low as 0.1 nm, as observed by atomic force microscopy. High-resolution x-ray diffraction analysis and reciprocal space maps showed pseudomorphic film growth, a very smooth film/substrate interface, excellent film crystallinity with a rocking curve of 0.012° (ω scans), and an in-plane compressive strain without relaxation. In addition, spherical aberration-corrected scanning transmission electron microscopy showed an atomically abrupt interface between the EuIG film and GGG. The saturation magnetization (Ms) and coercive field (Hc) were measured using a vibrating sample magnetometer. The square-shaped out-of-plane M-H loops in conjunction with angle-dependent x-ray magnetic dichroism demonstrated the PMA in the films. The spin Hall magnetoresistance on Pt/EuIG samples was measured to obtain the PMA field strength (H⊥), which increases from 4.21 to 18.87 kOe with the increasing Eu/Fe ratio and in-plane compressive strain. We also measured spin transport in the Pt/EuIG bilayer structure and directly obtained the real part of spin mixing conductance to be 3.48×10^14Ω–1m–2. We demonstrated current-induced magnetization switching with a low critical switching current density of 3.5×10^6A/cm2, showing excellent potential for low-dissipation spintronic devices.

Delta doping (δ-doping) can find a wide range of applications in advanced metal oxide semiconductor field effect transistors, deep UV photodetectors, quantum devices, and others. In this work, we formed a δ-doping layer in silicon by employing flash lamp annealing to treat the PCl3 monolayers grafted on silicon surfaces. The δ-doping layer is atomically thin (<1 nm). Low-temperature Hall measurements show that the δ-doping layer is in a metallic state and exhibits a weak localization phenomenon, implying that a two-dimensional electron gas is formed. When we form such an n-type δ-doping layer on a highly doped p-type Si substrate, a highly sensitive solar-blind UV photodetector is created, which traditionally was only possible by using wide band gap semiconductors such as gallium nitride (GaN) or silicon carbide (SiC).

For a reliable safety assessment for future deep underground repositories for highly active nu-clear waste a comprehensive understanding of the radionuclide retention by the surrounding host rock is required. Several parameters such as mineral heterogeneity and surface roughness, as well as pore water chemistry, influence radionuclide retention. Although many studies have been performed to investigate individual parameters, their interplay with each other is not yet well understood.

In our study, we focus on the sorption of trivalent curium on K-feldspar, a representative for the large alkali feldspar fractions contained in most crystalline rocks. We use cleaved macroscopic K-feldspar crystals and perform experiments at different pH values (5.5 and 6.9) to determine its impact on surface sorption with varying surface roughness. Furthermore, we investigate a K-feldspar mineral grain, which is part of a complex heterogeneous crystalline rock, obtained from the Grimsel Test Site.

To assess the sorption dependencies, we apply a correlative spectromicroscopy approach. In de-tail, the topography and surface roughness of the K-feldspar crystals as well as the mineral thin section is determined by vertical scanning interferometry. In addition, Raman microscopy deliv-ers information about the thin section’s surface mineralogy. The quantitative amount of sorbed Cm(III) is obtained by calibrated autoradiography and partially µTRLFS (micro-focus time-resolved laser-induced fluorescence spectroscopy), which is also the only method capable of measuring Cm(III) surface speciation on the molecular level via analysis of luminescence spec-tra and lifetimes.

Our results indicate that rougher K-feldspar surfaces exhibit increased Cm(III) uptake and stronger surface complexation. Similarly, the increase in pH leads to higher surface loading and stronger Cm(III) binding to the surface. Results obtained on the thin section reveal, that within a heterogeneous mineralogical system, sorption is affected by dissolution of neighboring minerals and competitive sorption between different mineral phases, such as mica and feldspar. The ob-tained findings express a need for investigating relevant processes on multiple scales of dimen-sion and complexity to better understand radionuclide retention by potential repository host rocks.

The authors acknowledge funding provided by the German Federal Ministry of Education and Research (iCross project 02NUK053B), the Helmholtz Association (iCross project SO-093 and CROSSING project PIE-0007), as well as by the German Federal Ministry of Economics and Technology (SMILE project 02E11668B). We thank F. Bok R. Moeckel, S. Beutner and S. Schöne.

ELBE is a compact, accelerator-driven photon and particle source. The variety of secondary radiation being offered extends from high-energy gamma rays to infrared and THz radiation as well as from neutrons to positrons and electrons. Since 2001 ELBE is operated as a user facility, providing more than 5500 hours of beamtime with an efficiency of more than 90% each year. The electron accelerator is based on four superconducting 9-cell TESLA cavities that are driven in CW operation to accelerate an average current of 1 mA up to beam energies of 40 MeV.

The the talk will summarize our experiences of operating TESLA cavities over two decades in CW. In detail, this includes the cavity performance and attempts to improve it, as well as investigations on their limitations. Additionally, we will discuss several issues that are related to the high average RF as well as beam power and we will present appropriate measures to protect the machine. In this regard we will also report on long-term experiences with our 10kW 1.3 GHz solid state power amplifiers and introduce a resonant ring for RF component tests at CW power levels up to 100 kW.

The contribution highlights the developments of superconducting radio frequency photo electron source (SRF gun) in Germany. The success at HZDR, as well as the progress at HZB and DESY are discussed. The presentation completes with detailed beam dynamics simulations for the typical bunch charges and an gives perspectives of high charge (1 nC) operation.

Throughout the coronavirus disease 2019 (COVID-19) pandemic, decision makers have relied on forecasting models to determine and implement non-pharmaceutical interventions (NPI). In building the forecasting models, continuously updated datasets from various stakeholders including developers, analysts, and testers are required to provide precise predictions. Here we report the design of a scalable pipeline which serves as a data synchronization to support inter-country top-down spatiotemporal observations and forecasting models of COVID-19, named the \textit{where2test}, for Germany, Czechia and Poland. We have built an operational data store (ODS) using PostgreSQL to continuously consolidate datasets from multiple data sources, perform collaborative work, facilitate high performance data analysis, and trace changes. The ODS has been built not only to store the COVID-19 data from Germany, Czechia, and Poland but also other areas. Employing the dimensional fact model, a schema of metadata is capable of synchronizing the various structures of data from those regions, and is scalable to the entire world. Next, the ODS is populated using batch Extract, Transfer, and Load (ETL) jobs. The SQL queries are subsequently created to reduce the need for pre-processing data for users. The data can then support not only forecasting using a version-controlled Arima-Holt model and other analyses to support decision making, but also risk calculator and optimisation apps. The data synchronization runs at a daily interval, which is displayed at https://www.where2test.de.

Die zunehmende Energieversorgung aus regenerativen Quellen erfordert ein höheres Maß an Flexibilität beim Betrieb thermischer Trennkolonnen. Vor diesem Hintergrund werden Bodenkolonnen vermehrt mit Festventilen ausgestattet, da diese im Vergleich zu anderen Bodentypen auch bei Teil- oder Überlastfahrweisen eine hohe Trenneffizienz aufweisen. Die Auslegung solcher Böden stellt in der Praxis jedoch eine Herausforderung dar, da es bislang an verlässlichen Daten und Methoden mangelt, um den Einfluss der Ventilanordnung auf die komplexe Zweiphasenströmung abzuschätzen. Im Rahmen eines aktuellen Forschungsprojektes soll daher ein grobskaliger CFD-Ansatz entwickelt werden, mit dessen Hilfe Strömungsszenarien auf Festventilböden mit vertretbarem Aufwand vorausberechnet werden können.
Im vorliegenden Beitrag werden erste Ergebnisse der Verwendung eines hybriden Modellierungsansatzes vorgestellt, mit dem sowohl disperse Strukturen als auch aufgelöste Phasengrenzflächen innerhalb einer Simulationsumgebung abgebildet werden können. Beispielhaft wird dieses Morphologie-adaptive Mehrfeld-Zweifluid-Modell hier zur Simulation der Strömung an einem einzelnen Festventil eingesetzt. Die Abbildung des Ventils erfolgt dabei nicht durch die Auflösung seiner Geometrie im Rechengitter, sondern durch die Implementierung lokaler Massen- und Impulsquellen in der Gasphase. Zur Verifikation der Simulationsergebnisse werden experimentelle Daten der Phasenverteilung um ein Ventil herangezogen, die an einem mit Luft und Wasser betriebenen Laborversuchstand mit einem Leitfähigkeitssensorarray erfasst wurden. Der Vergleich zeigt, dass die im zeitlichen Mittel auftretenden Phasengrenzflächen bei Verwendung statischer Quellterme bereits zufriedenstellend abgebildet werden können. Zur angemessenen Vorhersage des transienten Verhaltens ist jedoch eine Einbeziehung dynamischer Parameter erforderlich. Hierfür können beispielsweise experimentell ermittelte Ablösefrequenzen der Gasblasen vom Ventil verwendet werden. In weiterführenden Arbeiten soll der vielversprechende Ansatz zunächst auf Ventilgruppen und schließlich auf Böden im industriellen Maßstab übertragen werden.

This review article provides an overview of a range of recent technical developments in
advanced arterial spin labeling (ASL) methods that have been developed or adopted by
the community since the publication of a previous ASL consensus paper by Alsop et al.
1 . It is part of a series of review/recommendation papers from the International Society
for Magnetic Resonance in Medicine (ISMRM) Perfusion Study Group. Here, we focus
on advancements in readouts and trajectories, image reconstruction, noise reduction,
partial volume correction, quantification of non-perfusion parameters, fMRI,
fingerprinting, vessel selective ASL, angiography, deep learning, and ultra-high field
ASL. We aim to provide a high level understanding of these new approaches and some
guidance for their implementation, with the goal of facilitating the adoption of such
advances by research groups and by MRI vendors. Topics that are outside the scope of
this article, and are reviewed at length in separate articles, include velocity selective
ASL, multiple-timepoint ASL, body ASL, and clinical ASL recommendations.

Pressure drop, holdup and flooding points are essential factors for the hydraulic design of columns equipped with structured packings. This is also true for sandwich packings representing a combination of two alternating layers of conventional structured packings with different geometric surface areas. Such a combination results in a heterogeneous flow pattern evolving within certain operating ranges. In order to describe accurately the fluid dynamics over the entire operating range of both common structured packings and sandwich packings, a modelling approach is proposed based on conventional measurements and tomographic investigations. The approach distinguishes film-like flow patterns and froth regimes. For film-like flow patterns, packing-typical descriptions are used, whereas the froth in packings is described using an analogy to trays. Correlations were derived to determine the liquid holdup for film and froth flow, the dry and irrigated pressure drop as well as the gas velocities at the loading limits. The fluid dynamic model was verified with 1595 measurements for pressure drop and 510 measurements for holdup for the test system water/air.

When radionuclides (RNs) enter the food chain and are ingested by humans, they pose a potential health risk due to their radio- and chemotoxicity. After oral ingestion, RNs first come into contact and interact with the biofluids of the digestive system. For the development of a rapid as well as ef-ficient method for the decorporation of RNs, it is necessary to know the biokinetic processes as well as the speciation in the digestive system. Therefore, the aim of this work was to investigate the in-teractions of uranium(VI) with the biofluids of the human digestive system, with the gastrointesti-nal digestive segments stomach and small intestine as well as the whole digestive system at the mo-lecular level. To simulate the biofluids, saliva, gastric juice, pancreatic juice and bile, and the diges-tive segments were synthesized based on human physiology.[1] For the determination of chemical speciation, luminescence spectra were measured using time-resolved laser-induced fluorescence spectroscopy under cryogenic conditions (cryo-TRLFS) at 153 K. Species distribution was then de-termined by parallel factor analysis (parafac), where the resulting species were assigned using the spectra of the individual complexes. These results were compared with thermodynamic modeling.
Based on the TRLFS experiments, it can be shown that the speciation of uranium is predominantly dominated by the inorganic components, mainly carbonate and to a smaller extent phosphate. Among the organic components, only the protein mucin is involved in speciation at acidic pH val-ues, such as in the stomach. Therefore, the complexation of mucin with uranium(VI) was investi-gated in more detail.

This work is funded by the German Federal Ministry of Education and Research (BMBF) under grant number 02NUK057A and is part of the joint project RADEKOR.

[1] Wilke, C. et al. (2017) J. Inorg. Biochem. 175, 248-258.

Orangutans encounter habitat quality deterioration due to land-use changes and associated forest fires. This creates a complex stress scenario for the individual animals and threatens populations. The disturbance of forest canopies or loss of trees induce changes in primates' movement behavior: the preferred arboreal movement needs to be complemented by movements on the ground requiring more energy, and prolonging the search for fruiting and nesting trees. This all together leads to a change in the daily activity patterns (time spent to travel, feeding and resting) and subsequently to shift in the available energy budget decreasing the fitness of the animals. While agent-based models have been developed and widely employed to check the impact of disturbances or conservation management on the habitat use, population development and viability, there has been less emphasis on studying the direct impact of canopy disturbances on the arboreal movement of individual primates, which can be the origin of cascading effects on animals health, vitality and subsequent life processes. We developed the agent-based simulation model BORNEO (arBOReal aNimal movEment mOdel), which explicitly describes both orangutans' arboreal and terrestrial movement between trees in a forest depending on distances among trees and canopy structure. Orangutans in the model perform activities with a motivation to balance energy intake and expenditure involving mechanical work of locomotion. The model was tested with forest inventory data obtained in Sebangau National Park, Central Kalimantan, Indonesia. Information on tree constellations, sizes etc. were used to reconstruct a virtual forest with similar characteristics (e.g., trees network in terms of connections between overlapping canopies) as in the real world. In order to parameterise the energy related processes of the orangutans described in the model, we applied a computationally intensive evolutionary algorithm on high computing clusters and evaluated the simulation results against behavioural patterns of the orangutans observed in Sebangau. Both the simulated variability and proportion of activity budgets including feeding, resting, and travelling time for female and male orangutans respectively, confirmed the suitability of the model for its purpose. We used the calibrated model to compare the activity patterns and energy budgets of orangutans in both natural and disturbed forests. The results confirm field observations that orangutans in the disturbed forest are prone to experiencing deficit energy balance by spending more time travelling and less time feeding. The finding of a threshold of forest disturbances which affects a significant change in the activity pattern points out that forest deterioration may even threaten the survival of orangutans to some extent.

Our study (a) introduces the first agent-based model describing the arboreal movement of primates and can serve as a tool to investigate the direct impact of forest changes and disturbances on the behaviour of orangutans; and (b) demonstrates the suitability of high-performance computing to optimise the calibration of complex agent-based models describing animal behaviour at a fine spatiotemporal scale (1-meter and 1-second granularity).

Gold concentration usually consists of gravity separation and froth flotation. However, flotation faces difficulties due to gold-bearing ores often being refractory and finely disseminated in nature. Poor recovery and low flotation kinetics of fine particles are mainly due to the low frequencies of particle-bubble collisions and an increase in entrainment of fine gangue particles decreases the grade. In this study, applications of two pilot ImhoflotTM G-14 (tangential feed to the separator vessel with 1.4 m diameter) cells in an open circuit demonstrated its ability to recover fines with high gold grade and achieved a high recovery of 65–68 % for the particle size fraction of −20 µm. The gold content in the −20 µm fraction of tailings is only about 0.36 g/t, which is lower than in the existing flotation circuit (0.47 g/t), including rougher and scavenger banks. Furthermore, bubble size measurements indicate that pneumatic ImhoflotTM generated very fine bubbles in a high shear environment, improving particle-bubble collision frequencies.

Liquid foams occur whether intentionally or unintentionally across different industrial sectors. The detection of foam and characterization of its liquid content currently requires complex measurement methods such as electrical conductivity measurements. This paper presents a novel method for foam detection and characterization of its liquid fraction based on a capacitive level sensor. A correlation between the sensor output signal and defined liquid fractions of dry to wet foam indicated a high accuracy of this sensor technique. Regarding the sensor operation in different liquid solutions, a minimum screw-in depth is presented. The sensor allows minimal invasive inline measurements in equipment regardless of the wall material and extreme process conditions e.g. explosion hazard areas.

The development PET radioligands for imaging of the cannabinoid type 2 receptors (CB2R) has been intensively explored due to their upregulation in various pathological conditions [1]. Recently, we reported the development of [18F]JHU94620 [2], however, this radioligand suffered from low metabolic stability in vivo. Here, we describe the development of the deuterated analogues [18F]JHU94620-d4 and -d8 as well as their biological evaluation (Figure 1). The precursors for radiofluorination were obtained by coupling 4,5-dimethylthiazol-ylidene-2,2,3,3-tetramethylcyclopropane-1-carboxamide with either d4 or d8 1,4-butanediol-bistosylate and radiofluorinated in the presence of Kryptand K2.2.2. and K2CO3. [18F]JHU94620-d4 and -d8 were obtained in 10% radiochemical yield and >99% radiochemical purity. The fraction of radiometabolites was quantified in mice plasma, brain and spleen of CD1 mice at 30 min p.i. Both [18F]JHU94620-d4 and -d8 demonstrated an improved metabolic stability with 80% intact radioligand detected in the brain vs. 36% for [18F]JHU94620. The CB2 affinity and specificity of [18F]JHU94620-d8 was determined by in vitro binding experiments and a KD(rCB2) of 0.36 nM was determined. Additionally, we evaluated the [18F]JHU94620-d8 uptake by PET-studies into the spleen of healthy rats and in a rat model carrying an adeno-associated viral (AAV2/7) vector expressing hCB2R(D80N) at high densities in the right striatum (hCB2-rs) [3, 4]. Our PET study with [18F]JHU94620-d8 revealed a rCB2 specific uptake into the spleen (AUC0-30min = 33 vs. 17 SUV min after blocking with GW405833). In the hCB2-rs model we could show a target specific uptake of [18F]JHU94620-d8 with a constant SUV of 6.7±0.3 from 6 to 60 min p.i. and an SUVr (right striatum-to-cerebellum) of 43±7at 60 min p.i., as well as a reversible binding in displacement studies. Thus, [18F]JHU94620-d8 is a new PET tracer with improved metabolic stability and excellent ability to image the CB2 receptors in-vivo. Its further evaluation is underway.

Six mononuclear tetravalent actinide complexes (1-6) have been synthesized using a new Schiff base ligand 2-methoxy-6-(((2-methyl-1-(pyridin-2-yl)propyl)imino)methyl)phenol (HLpr). The HLpr is treated with tetravalent actinide elements in varied stoichiometry to afford mononuclear 1:1 complexes [MCl3-Lpr∙nTHF] (1-3) and 2:1 complexes [MCl2-Lpr2] (4-6) (M = Th4+ (1 and 4), U4+ (2 and 5) and Np4+ (3 and 6)). All complexes are characterized using different analytical techniques such as IR, NMR, and absorption spectroscopy as well as crystallography. UV-vis spectroscopy revealed more red-shifted absorption spectra for 2:1 complexes as compared to 1:1 complexes. 1H NMR of Th(IV) complexes exhibit diamagnetic spectra whereas U(IV) and Np(IV) complexes revealed paramagnetically shifted 1H NMR. Interestingly, NMR signals are paramagnetically shifted between -70 to 40 ppm in 2 and 3, but are confined within -35 to 25 ppm in 2:1 complexes 5 and 6. Single crystal structures for 1:1 complexes revealed an eight-coordinated Th(IV) complex (1) and seven-coordinated U(IV) (2) and Np(IV) (3) complexes. Whereas, all 2:1 complexes 4-6 were isolated as eight-coordinated isostructural molecules. The geometry around the Th4+ center in 1 is found to be trigonal dodecahedral and, capped trigonal prismatic around U(IV) and Np(IV) centers in 2 and 3, respectively. Whereas, An4+ centers in 2:1 complexes are present in dodecahedral geometry. Importantly, 2:1 complexes exhibit increased bond distances in comparison to their 1:1 counterparts as well as interesting bond modulation w.r.t. ionic radii of An(IV) centers. Cyclic voltammetry displays an increased oxidation potential of the ligand by 300 to 500 mV, after coordination with An4+. CV studies indicates Th(IV)/Th(II) reduction beyond −2.3 V whereas attempts were made to identify redox potentials for U(IV) and Np(IV) centers. Spectroscopic binding studies reveal that complex stability in 1:1 stoichiometry follows the order Th4+≈ U4+ > Np4+.

The radiocarbon bomb-pulse created by nuclear weapons testing in the 1950s and 1960s has created a massive spike of atmospheric ¹⁴C, which has been used in the study of the global carbon cycle in many subsystems including the marine environment. Coral records of bomb-pulse era ¹⁴C have been studied over the past decades to gain insight into the uptake and mixing of atmospheric CO₂ in the ocean. The ¹⁴C level seen in surface waters is specific to the origin of the water masses and ocean-atmosphere exchange of CO₂.
We present results for radiocarbon levels in coral aragonite with yearly resolution for a coral core from Belize. The core has a well-established stratigraphy, stretching from the onset of atmospheric testing of thermonuclear devices to 2007. The core has previously been analyzed for and trace metal content in relation to environmental impacts and the bomb-pulse of ²³⁶U. We compare the results with existing results and model expectations for the Caribbean Sea. We further discuss the close agreement for the prior results in terms of feasibility and the achievable accuracy of cross-dating of cores using the rise of radiocarbon by the atmospheric bomb-pulse.

The study of matter under extreme densities and temperatures as they occur e.g. in astrophysical objects and nuclear fusion applications has emerged as one of the most active frontiers in physics, material science, and related disciplines. In this context, a key quantity is given by the dynamic structure factor S(q,ω), which is probed in scattering experiments -- the most widely used method of diagnostics at these extreme conditions. In addition to its crucial importance for the study of warm dense matter, the modeling of such dynamic properties of correlated quantum many-body systems constitutes one of the most fundamental theoretical challenges of our time. Here we report a hitherto unexplained roton feature in S(q,ω) of the warm dense electron gas [1], and introduce a microscopic explanation in terms of a new electronic pair alignment model [2]. This new paradigm will be highly important for the understanding of warm dense matter, and has a direct impact on the interpretation of scattering experiments. Moreover, we expect our results to give unprecedented insights into the dynamics of a number of correlated quantum many-body systems such as ultracold helium, dipolar supersolids, and bilayer heterostructures.

In this work, we demonstrate the usability of a fully-2D-material based device consisting of MoS2/WSe2 heterojunction encapsu-lated by hBN and contacted by graphene as temperature sensor for linear temperature measurement at cryogenic temperatures. More precisely, temperatures in the range of 10 K up to 300 K were applied to the device while recording the I-V characteris-tics. From this, we had a deeper look on the current transport mechanism by obtaining the activation energy of the saturation current in the Arrhenius diagram. It is 1.3 eV, which can be related to the bandgap of MoS2 or WSe2 (both nominal 1.3 eV) as for traditional pn-junction diodes in bulk materials. Further-more, we applied a constant forward current to the device while measuring the voltage drop at different temperatures to investi-gate the temperature-sensor performance. In the range of 40 K up to 300 K, the sensitivity of the sensor is ~2 mV/K, which is comparable to Si devices, while the linearity is still lower (R2 ~ 0.94). On the other hand, the demonstrated device consists only of 2D materials and is, thus, substrate independent, ultra-thin, and can be fabricated on a fully flexible substrate in a low-cost process.

Article and Suplementary information available on the Open Access Journal:https://www.mdpi.com/2079-4991/12/12/1968/htm

Figure S1: Nonstandard 2D MFM images of a single NW for an applied magnetic field of (a) ±47 mT and (b) ±28 mT;
Figure S2: (a) Sketch of two simulated CoNi/Cu NWs with different segments and Cu layer lengths. (b) Hysteresis loops of NWs with different anisotropies (68° and 65° with respect to NW axis) and geometries as shown in (a). (c) Zoom of hysteresis loops of NWs with anisotropy at 65° and different geometries.

We introduce a practical hybrid approach that combines orbital-free density functional theory (DFT) with Kohn-Sham DFT for speeding up first-principles molecular dynamics simulations. Equilibrated ionic configurations are generated using orbital-free DFT for subsequent Kohn-Sham DFT molecular dynamics. This leads to a massive reduction of the simulation time without any sacrifice in accuracy. We assess this finding across systems of different sizes and temperature, up to the warm dense matter regime. To that end, we use the cosine distance between the time series of radial distribution functions representing the ionic configurations. Likewise, we show that the equilibrated ionic configurations from this hybrid approach significantly enhance the accuracy of machine-learning models that replace Kohn-Sham DFT. Our hybrid scheme enables systematic first-principles simulations of warm dense matter that are otherwise hampered by the large numbers of atoms and the prevalent high temperatures. Moreover, our finding provides an additional motivation for developing kinetic and noninteracting free energy functionals for orbital-free DFT.

We report on the operation of the DRACO Laser Driven electron source for stable multi-day operation of secondary applications with demanding beam requirements. The nC-class accelerator delivers charge densities around 10 pC/MeV*, 1 mrad rms divergence at energies up to 0.5 GeV and peak currents of over 10kA**. Precise characterisation is paramount for controlled operation of demanding applications, this includes: spectrally resolved charge diagnostic, source size diagnostics based both on betatron radiation*** as well as on coherent optical transition radiation (TR) to resolve microbunch beam structures**** and TR-based multioctave high-dynamic range spectrometry for sub-fs resolved characterisation of the 10 fs rms electron bunches**. Achieved stability allows systematic exploration of applications, resulting in the recent demonstration of the first LWFA based Beam-driven Plasma Wakefield Accelerator*****. In an effort toward LWFA based Free Electron Lasing, the COXINEL manipulation line developed at Synchrotron SOLEIL was recently installed at our facility. At initial commissioning, successful beam transport was achieved with over 13000 delivered shots within 9 experimental days.

* J.P. Couperus et al., Nat. Comm. 8 (2017)
** O. Zarini et al., PRAB (2022)
*** A. Köhler et al., PRAB (2021)
**** A. Lumpkin et al., PRL 125 (2020)
***** T. Kurz et al., Nat. Comm. 12 (2021)

Wenn Radionuklide (RN) in die Nahrungskette gelangen und vom Menschen aufgenommen werden, stellen sie aufgrund ihrer Radio- und Chemotoxizität ein mögliches Gesundheitsrisiko dar. Dabei kommen die RN nach der oralen Aufnahme zuerst mit den Biofluiden des Verdauungssystems in Kontakt und interagieren mit diesen. Die Ausscheidung der Schwermetalle erfolgt größtenteils renal. Für die Entwicklung einer schnellen sowie effizienten Methode zur Dekorporation der RN ist es notwendig, die biokinetischen Prozesse sowie die Speziation im Verdauungs- und Ausscheidungssystem zu kennen. Ziel dieser Arbeit ist es daher, die Wechselwirkungen von Uran(VI) mit den Biofluiden des menschlichen Verdauungssystems, mit den gastrointestinalen Verdauungssegmenten Magen und Dünndarm sowie des gesamten Verdauungssystems auf molekularer Ebene zu untersuchen. Für die Simulierung der Biofluide wurden Speichel, Magen-, Pankreassaft und Gallenflüssigkeit sowie die Verdauungssegmente basierend auf der menschlichen Physiologie synthetisch hergestellt.[1] Die chemische Speziation wurde mittels zeitaufgelöster laserinduzierter Fluoreszenz-Spektroskopie unter kryogenen Bedingungen (Kryo-TRLFS) bei 153 K untersucht sowie die Ergebnisse mit thermodynamischen Modellierungen verglichen.
Anhand der TRLFS-Experimente kann gezeigt werden, dass die Speziation von Uran überwiegend von den anorganischen Bestandteilen, hauptsächlich Carbonat und zu einem geringeren Anteil Phosphat, dominiert wird. Bei den organischen Komponenten ist lediglich das Protein Mucin bei sauren pH-Werten, wie z. B. im Magen, an der Speziation beteiligt, weshalb die Komplexierung von Mucin mit Uran(VI) genauer betrachtet wurde. Des Weiteren wurden Zellexperimente mit Nierenzellen von Menschen (HEK-293) und Ratten (NRK-52E) in vitro durchgeführt, um den Effekt von Uran auf die Zellen mittels XTT-Assays zu untersuchen. Um den biochemischen Mechanismus auf molekularer Ebene zu verstehen, wurde die Speziation von Uran im Zellkulturmedium ebenfalls mittels Kryo-TRLFS analysiert. Bei der Hauptspezies, welche auf die Zellen einwirkt, handelt es sich um eine Uranylcarbonatverbindung.
Diese Arbeit wird vom Bundesministerium für Bildung und Forschung (BMBF) unter dem Förderkennzeichen 02NUK057A gefördert und ist Teil des Verbundprojekts RADEKOR.
Referenzen:
[1] C. Wilke et al., J. Inorg. Biochem. 2017, 175, 248-258.

Technetium-99m (99mTc, t1/2 = 6.007 h) has been widely used for radiodiagnostic purposes for decades, and it is still one of the most used radioisotopes worldwide with an estimated 40 million doses consumed annually. Tc-99m can be produced through various nuclear transmutation methods, but commercially speaking, it is generally derived from molybdenum-99 (99Mo, t1/2 = 65.925 h), where the origin of it is dependent upon chemistry and isotopic composition of the target material, e.g., natural or enriched Mo, or enriched 235U targets. However, the production and distribution of 99mTc relies on a complex supply-chain that has proven itself prone to disruptions in years past and was most recently observed during the SARS-CoV-2 pandemic.[1] Ultimately, this leads to delays on diagnoses of patients due to postponed imaging procedures as well as the loss of material and capital.
As a solution to this problem, the deployment of a decentralised network of compact accelerator neutron sources (CANS) for producing 99mTc and 101Tc (t1/2 = 14.22 min) using the (n,𝛾) reaction on Mo-based targetry has been proposed.[2] For example, the use of fusion-driven deuterium-deuterium (D-D) neutron generators for producing both 99mTc and 101Tc has been demonstrated along with their subsequent isolation using a separation tailored for low-specific activity 99Mo targets.[2]
Another under-utilised source of neutrons already being generated in this fashion is during the production of many positron emission tomography (PET) radionuclides in cyclotrons, where parasitic neutrons are liberated from the cyclotron target, e.g., 18O(p,n)18F. The implementation of larger production batches, high yield targetry, and more production runs are all complementary to generating neutrons. From this, the hybridised production of 99mTc and 101Tc concurrently during [18F]FDG has been demonstrated and its feasibility explored.[3]
The aim of the work presented herein is to compare various CANS production modes for 99mTc and 101Tc production in regards to their subsequent applications. Further, it provides potential alternatives for the future production of radiopharmaceuticals, meanwhile meeting the objectives of several Unesco and sustainable development goals.

REFERENCES
[1] K. SADRI, V.R. DABBAGH, M.N. FORGHANI, M. ASADI, R. SADEGUI, Lymphoscintigraphy in the Time of COVID-19: Effect of Molybdenum-99 Shortage on Feasibility of Sentinel Node Mapping, Lymphat. Res. Biol. 19 (2021) 134–140.
[2] E.J. MAUSOLF, E.V. JOHNSTONE, N. MAYORDOMO, D.L. WILLIAMS, E.Y.Z. GUAN, C.K. GARY, Fusion-Based Neutron Generator Production of Tc-99m and Tc-101 : A Prospective Avenue to Technetium Theranostics, Pharmaceuticals. 14 (2021) 1–19.
[3] E.V. JOHNSTONE, E.J. MAUSOLF. Hybridized Production of 18F and 99mTc on a Low-Energy Cyclotron. Internal Document, IFS, LLC (2021).

Background

PSMA PET is frequently used for staging of prostate cancer patients. Furthermore, there is increasing interest to use PET information for personalized local treatment approaches in surgery and radiotherapy, especially for focal treatment strategies. However, it is not well established which quantitative imaging parameters show highest correlation with clinical and histological tumor aggressiveness.

Methods

This is a retrospective analysis of 135 consecutive patients with non-metastatic prostate cancer and PSMA PET before any treatment. Clinical risk parameters (PSA values, Gleason score and D’Amico risk group) were correlated with quantitative PET parameters maximum standardized uptake value (SUVmax), mean SUV (SUVmean), tumor asphericity (ASP) and PSMA tumor volume (PSMA-TV).

Results

Most of the investigated imaging parameters were highly correlated with each other (correlation coefficients between 0.20 and 0.95). A low to moderate, however significant, correlation of imaging parameters with PSA values (0.19 to 0.45) and with Gleason scores (0.17 to 0.31) was observed for all parameters except ASP which did not show a significant correlation with Gleason score. Receiver operating characteristics for the detection of D’Amico high-risk patients showed poor to fair sensitivity and specificity for all investigated quantitative PSMA PET parameters (Areas under the curve (AUC) between 0.63 and 0.73). Comparison of AUC between quantitative PET parameters by DeLong test showed significant superiority of SUVmax compared to SUVmean for the detection of high-risk patients. None of the investigated imaging parameters significantly outperformed SUVmax.

Conclusion

Our data confirm prior publications with lower number of patients that reported moderate correlations of PSMA PET parameters with clinical risk factors. With the important limitation that Gleason scores were only biopsy-derived in this study, there is no indication that the investigated additional parameters deliver superior information compared to SUVmax.

Technetium is the lightest element without a stable isotope. The β‑emitting ⁹⁹Tc is especially relevant for nuclear waste management due to its long half-life (ca. 2.1×10⁵ years) and relatively high formation yield (≥6%) in ²³⁵U and ²³⁹Pu nuclear reactors. In this context, redox reactions at mineral/water interfaces are crucial for the safety of nuclear waste repositories.

In the absence of complexing agents, Tc exists in water as Tc(VII) and Tc(IV). The former predominates in non-reducing conditions as TcO₄⁻(aq), which is highly mobile in the environment due to its solubility and weak interaction with adsorbents. Studies show that Fe(II) minerals can reduce Tc(VII) to Tc(IV), which is then immobilized by adsorption onto or incorporation into the oxidized Fe mineral and by precipitation as TcO₂·xH₂O. However, even in the simpler case (precipitation) the structure of TcO₂·xH₂O remains controversial.

Lukens et al. [1] demonstrated that, despite being amorphous, TcO₂·xH₂O has a well-defined local structure. Based on EXAFS measurements, they proposed that TcO₂·xH₂O forms linear chains of equally spaced edge-sharing TcO₄(H₂O)₂ octahedra, with terminal H₂O ligands at the apical positions. Vichot et al. [2] obtained similar results but, despite having extracted only one Tc‑Tc distance from the EXAFS, proposed that Tc atoms would be separated by shorter and longer alternating distances as in the monoclinic TcO₂ crystal. More recently, Yalçintaş et al. [3] showed that both models can be fitted equally well to the EXAFS and, thus, the TcO₂·xH₂O structure remained unsolved.

In this work, we use density functional theory (DFT) to investigate the polymeric TcO₂·xH₂O structure. Our calculations reveal that, in contrast to previous models, a zigzag configuration with the terminal H₂O groups at neighboring positions of the octahedra is more likely. The zigzag configuration is energetically more favored and results in a better agreement with the EXAFS measurement.

[1] Lukens et al. (2002), Environ. Sci. Technol. 36, 1124-1129.
[2] Vichot et al. (2002), Radiochim. Acta 90, 575-579.
[3] Yalçintaş et al. (2016), Dalton Trans. 45, 17874-17885.

Dithiine linkage formation via a dynamic and self-correcting nucleophilic aromatic substitution reaction enables the de novo synthesis of a porous thianthrene-based two-dimensional covalent organic framework (COF). For the first time, this organo-sulfur moiety is integrated as a structural building block into a crystalline layered COF. The structure of the new material deviates from the typical planar interlayer stacking of the COF to form undulated layers caused by bending along the C-S-C bridge, without loss of aromaticity and crystallinity of the overall COF structure. Comprehensive experimental and theoretical investigations of the COF and a model compound, featuring the thianthrene moiety, suggest partial delocalization of sulfur lone pair electrons over the aromatic backbone of the COF decreasing the band gap and promoting redox activity.
Postsynthetic sulfurization allows for direct covalent attachment of polysulfides to the carbon backbone of the framework to afford a molecular-designed cathode material for lithium-sulfur (Li-S) batteries with a minimized polysulfide shuttle. The fabricated coin cell delivers nearly 77% of the initial capacity even after 500 charge-discharge cycles at 500 mA/g current density. This novel sulfur linkage in COF chemistry is an ideal structural motif for designing model materials for studying advanced electrode materials for Li-S batteries on a molecular level.

The cyclin-dependent kinase 4 and 6 (CDK4/6) inhibitor palbociclib is an emerging cancer therapeutic that just recently gained Food and Drug Administration approval for treatment of estrogen receptor (ER)-positive, human epidermal growth factor receptor (Her)2-negative breast cancer in combination with the ER degrader fulvestrant. However, CDK4/6 inhibitors are not cancer-specific and may affect also other proliferating cells. Given the importance of T cells in antitumor defense, we studied the influence of palbociclib/fulvestrant on human CD3+ T cells and novel emerging T cell-based cancer immunotherapies. Palbociclib considerably inhibited the proliferation of activated T cells by mediating G0/G1 cell cycle arrest. However, after stopping the drug supply this suppression was fully reversible. In light of combination approaches, we further investigated the effect of palbociclib/fulvestrant on T cell-based immunotherapies by using a CD3-PSCA bispecific antibody or universal chimeric antigen receptor (UniCAR) T cells. Thereby, we observed that palbociclib clearly impaired T cell expansion. This effect resulted in a lower total concentration of interferon-g and tumor necrosis factor, while palbociclib did not inhibit the average cytokine release per cell. In addition, the cytotoxic potential of the redirected T cells was unaffected by palbociclib and fulvestrant. Overall, these novel findings may have implications for the design of treatment modalities combining CDK4/6 inhibition and T cell-based cancer immunotherapeutic strategies.

Radiation-induced embrittlement of nuclear steels is one of the main limiting factors for safe long-term operation of nuclear power plants. In support of accurate and safe reactor pressure vessel (RPV) lifetime assessments, we developed a physics-based model that predicts RPV steel hardening and subsequent embrittlement as a consequence of the formation of nano-sized clusters of minor alloying elements. This model is shown to provide reliable assessments of embrittlement for a very wide range of materials, with higher accuracy than industrial correlations. The core of our model is a multiscale modelling tool that predicts the kinetics of solute clustering, given the steel chemical composition and its irradiation conditions. It is based on the observation that the formation of solute clusters ensues from atomic transport driven by radiation-induced mechanisms, differently from classical nucleation-and-growth theories. We then show that the predicted information about solute clustering can be translated into a reliable estimate for radiation-induced embrittlement, via standard hardening laws based on the dispersed barrier model. We demonstrate the validity of our approach by applying it to hundreds of nuclear reactors vessels from all over the world.

In spectroscopy studies of solids, interaction between a discrete mode and a continuum of excitations sometimes leads to an interference effect known as the Fano resonance, characterized by the asymmetric scattering amplitude of the discrete mode as a function of electromagnetic driving frequency. Cuprate high-Tc superconductors are known for its intertwined interactions and the coexistence of competing orders. In this study, we report a new type of Fano resonance manifested by the collective amplitude oscillations of the superconducting order, i.e. the Higgs mode, in cuprate high-Tc superconductors, where we resolve both the amplitude and phase signatures of the Fano resonance. Our observation suggests that the heavily damped Higgs mode is coupled to another collective mode in the system. Based on the results of an extensive hole-doping and magnetic field dependent investigation, we speculate charge density wave fluctuations as the coupled mode. Our study highlights the possibility of a dynamical interaction between superconductivity and charge density wave in cuprate high-Tc superconductors, which demonstrates the scientific prospect of Higgs spectroscopy as a new type of spectroscopy method.

Single iron atom and nitrogen-codoped carbon (Fe–N–C) electrocatalysts, which have great potential to catalyze the kinetically sluggish oxygen reduction reaction (ORR), have been recognized as the most promising alternatives to the precious metal platinum. Unfortunately, the ORR properties of the existing Fe–N–C catalysts are significantly hampered by the inferior accessibility and intrinsic activity of FeN4 moieties. Here, we constructed densely exposed surface FeN4 moieties on a hierarchically porous carbon (sur-FeN4-HPC) by Fe ion anchoring and a subsequent pyrolysis strategy using the nitrogen- doped hierarchically porous carbon (NHPC) as the scaffold. The high surface area of the NHPC with abundant surface Fe anchoring sites enabled the successful fabrication of densely accessible FeN4 active moieties (34.7 􏰁x 10^19 sites g^-􏰂1) on sur-FeN4-HPC. First-principles calculations further suggested that the edge effect could regulate the electronic structure of the single Fe site, hence promoting the intrinsic ORR activity of the FeN4 moiety. As a result, the sur-FeN4-HPC electrocatalyst exhibited excellent ORR activity in acidic media with a high half-wave potential of 0.83 V (vs. the reversible hydrogen electrode). We further examined sur-FeN4-HPC as a cathode catalyst in proton exchange membrane fuel cells (PEMFCs). The membrane electrode assembly delivered a high current density of 24.2 mA cm􏰂2 at 0.9 ViR-free (internal resistance-compensated voltage) under 1.0 bar O2 and a maximum peak power den- sity of 0.412 W cm􏰂2 under 1.0 bar air. Importantly, the catalyst demonstrated promising durability during 30000 voltage cycles under harsh H2 and air conditions. The PEMFC performance of sur-FeN4-HPC outperforms those of the previously reported Fe–N–C electrocatalysts. The engineering of highly acces- sible and dense surface FeN4 sites on sur-FeN4-HPC offers a fruitful pathway for designing high- performance electrocatalysts for different electrochemical processes.

Lanmodulin (LanM), a naturally lanthanide (Ln)-binding protein with a remarkable selectivity for Lns over Ca(II ) and affinities in the picomolar range, is an attractive target to address challenges in Ln separation. Why LanM has such a high selectivity is currently not entirely understood; both specific amino acid
sequences of the EF-Hand loops and cooperativity effects have been suggested. Here, we removed the effect of cooperativity and synthesised all four 12-amino acid EF-Hand loop peptides, and investigated their affinity for two Lns (Eu( III) and Tb(III)), the actinide Cm(III) and Ca(II). Using isothermal titration calorimetry and time-resolved laser fluorescence spectroscopy (TRLFS) combined with parallel factor analysis, we show that the four short peptides behave very similarly, having affinities in the micromolar range for Eu(III) and Tb(III). Ca(II) was shown not to bind to the peptides, which was verified with circular dichroism spectroscopy. This technique also revealed an increase in structural organisation upon Eu(III) addition, which was supported by molecular dynamics simulations. Lastly, we put Eu(III) and Cm(III) in direct competition using TRLFS. Remarkably, a slightly higher affinity for Cm(III) was found. Our results demonstrate that the picomolar affinities in LanM are largely an effect of pre-structuring and therefore a reduction of flexibility in combination with cooperative effects, and that all EF-Hand loops possess similar affinities when detached from the protein backbone, albeit still retaining the high selectivity for lanthanides and actinides over calcium.

In cove-edged zigzag graphene nanoribbons (ZGNR-C), one terminal CH group per length unit is removed on each zigzag edge, forming a regular pattern of coves which controls their electronic structure. Based on three structural parameters that unambiguously characterize the atomistic structure of ZGNR-C, we present a scheme that classifies their electronic state, i.e., if they are metallic, topological insulators or trivial semiconductors, for all possible widths N, unit lengths a and cove position offsets at both edges b, thus showing the direct structure-electronic structure relation. We further present an empirical formula to estimate the band gap of the semiconducting ribbons from N,a, and b. Finally, we identify all geometrically possible ribbon terminations and provide rules to construct ZGNR-C with well-defined electronic structure.

Interfacial synthetic Cu-phthalocyanine-based two-dimensional conjugated metal-organic framework (CuPc-CuO4 2D c-MOF) films were transferred to graphite electrodes and analyzed via electrochemical resonance Raman spectroscopy. Comparison of CuPc-CuO4 with the corresponding monomer, combined with Density Functional Theory (DFT) calculations allowed a detailed assignment of the vibrational bands. CuPc-CuO4 films attached to graphite electrodes via an Nickel-Nitrilo Triaacetic Acid (Ni-NTA) linker exhibited excellent bifunctional catalytic activity towards oxygen reduction (ORR) and oxygen evolution (OER) reaction. Potential dependent Raman spectroscopy yielded three different species in the respective potential window that could be assigned to an ORR active CuI/CuI state, an inactive CuII/CuI state and an CuII/CuII state that could be activated for OER. From the spectroelectrochemical data, the redox potentials of Cu in the CuPc moieties and the Cu-catecholate nodes could be determined to be ECuPc = -0.04 V and ECuO4 = 0.33 V vs. Ag|AgCl, respectively. Furthermore, DFT calculations of bandagps and density of states showed the smalest bandgap and highest -conjugation for the CuI/CuI state and the largest bandgap and lower conjugation for the mixed CuII/CuI state state, agreeing very well with the experimental activity of the species. Our results suggest that the coupling between metal oxidation changes and long range electron transfer of the 2D c-MOF is a key parameter to achieve the high electrocatalytic activity.

A conceptually new approach to synchronizing accelerator-based light sources and external laser systems is presented. The concept is based on utilizing a sufficiently intense accelerator-based single-cycle terahertz pulse to slice a thereby intrinsically synchronized femtosecond-level part of a longer picosecond laser pulse in an electro-optic crystal. A precise synchronization of the order of 10 fs is demonstrated, allowing for real-time lock-in amplifier signal demodulation. We demonstrate successful operation of the concept with three benchmark experiments using a 4th generation accelerator-based terahertz light source, i.e. (i) far-field terahertz time-domain spectroscopy, (ii) terahertz high harmonic generation spectroscopy, and (iii) terahertz scattering-type scanning near-field optical microscopy.

For millennia, ceramics have been densified via sintering in a
furnace, a time-consuming and energy-intensive process. The need
to minimize environmental impact calls for new physical concepts
beyond large kilns relying on thermal radiation and insulation. Here,
we realize ultrarapid heating with intense blue and UV-light.
Thermal management is quantified in experiment and finite element
modelling and features a balance between absorbed and radiated
energy. With photon energy above the band gap to optimize
absorption, bulk ceramics are sintered within seconds and with
outstanding efficiency (~2 kWh/kg) independent of batch size.
Sintering on-the-spot with blacklight as a versatile and widely
applicable power source is demonstrated on ceramics needed for
energy storage and conversion and in electronic and structural
applications foreshadowing economic scalability.

Flash lamp annealing is a non-equilibrium annealing method on the sub-second time scale which excellently meets the requirements of thin film processing. It has already been used in microelectronics to activate dopants, to recrystallize amorphous semiconductor layers and to anneal out defects. However, in the last 20 years, flash lamp annealing has opened up new areas of application like thin films on glass, sensors, printed electronics, flexible electronics, batteries etc. Since two years, the Helmholtz Innovation blitzlab aims to transfer this technology to industry and application-related research.
In this presentation, we give a short introduction to flash lamp annealing and discuss the pros and cons of this technology for thin film and semiconductor processing. In the main part we report about our activities in the field of Ge-based materials for electronic applications. This includes the n-type doping of Ge above the solubility level by ion implantation and flash lamp annealing, the doping of GeSn alloys, and the fabrication of NiGe for contact formation.

The presentation gives a short overview of our recent activities to dope GaN with Mg by ion implantation and flash lamp annealing.

Contactless inductive flow tomography (CIFT) is a flow measurement technique developed at Helmholtz-Zentrum Dresden-Rossendorf that can reconstruct the global 3D flow field in electrically conducting fluids such as liquid metals. The velocity field of the moving fluid can be reconstructed by solving the underlying inverse problem using appropriate regularization methods. This publication introduces the key concept and mathematical foundation of the method and illustrates the measurement capability of CIFT on two examples: continuous casting of steel in applied fluid dynamics and Rayleigh-Bénard convection as a paradigmatic system in fundamental fluid dynamics.

The necessity of exhaustive documentation of research data arises from an increasing depth of scientific understanding and investigations of unknown phenomena with research teams of different areas and fields. Different methods and definitions and insufficient documentation of field work, experimental and numerical examinations lead to information loss, especially over time. To counteract this problem the scientific community aims to make research data Findable, Accessible, Interoperable and Reusable (FAIR). Unfortunately infrastructure, tools, personnel and acceptability for these additional steps are often missing and result in the mentioned paucity of information and data. Within the Helmholtz Association the Helmholtz Metadata Collaboration (HMC) has taken on the task of building this infrastructure to support high quality data documentation and publication throughout the entire lifecycle of research data and to raise the awareness for necessary structural changes in the wider scientific community.
One goal of HMC is the mapping of existing data management structures and demands in the different research fields of the Helmholtz Community. These fields are especially addressed with Hubs, being the connection between HMC and the specific needs of the research fields. Based on the collected information HMC will implement tools to assist scientists, data managers and IT administrators in making their research data FAIR. Furthermore members of HMC will connect with other (meta-)data initiatives to work towards necessary structural changes in the world of scientific research by e.g. defining standards.
In this poster we will discuss the FAIR principles and introduce the Helmholtz Metadata Collaboration and their tasks. Also, we will show concrete examples from the geoscientific part of Hub Energy. The Hub in which we are active.

The diiron compounds [Fe2Cp2(CO)2(μ-CO)(μ-CSEt)]CF3SO3, [1]CF3SO3, K[Fe2Cp2(CO)3(CNCH2CO2)], K[2], [Fe2Cp2(CO)2(μ-CO)(μ-CNMe2)]NO3, [3]NO3, [Fe2Cp2(CO)2(PTA){μ-CNMe(Xyl)}]CF3SO3, [4]CF3SO3, and [Fe2Cp2(CO)(μ-CO){μ−η:1η3-C(4-C6H4CO2H)CHCNMe2}]CF3SO3, [5]CF3SO3, containing a bridging carbyne, isocyanoacetate, or vinyliminium ligand, were investigated for their photoinduced cytotoxicity. Specifically, the novel water-soluble compounds K[2], [3]NO3, and [4]CF3SO3 were synthesized and characterized by elemental analysis and IR and multinuclear NMR spectroscopy. Stereochemical aspects concerning [4]CF3SO3 were elucidated by 1H NOESY NMR and single-crystal X-ray diffraction. Cell proliferation studies on human skin cancer (A431) and nontumoral embryonic kidney (HEK293) cells, with and without a 10-min exposure to low-power UV light (350 nm), highlighted the performance of the aminocarbyne [3]NO3, nicknamed NIRAC (Nitrate-Iron-Aminocarbyne), which is substantially nontoxic in the dark but shows a marked photoinduced cytotoxicity. Spectroscopic (IR, UV−vis, NMR) measurements and the myoglobin assay indicated that the release of one carbon monoxide ligand represents the first step of the photoactivation process of NIRAC, followed by an extensive disassembly of the organometallic scaffold.

Nano-structured cones have gained much attention due to their superior super-hydrophobic and electrocatalytic properties recently. This work aims to explore if magnetic fields could support the electrodeposition of nano-cone arrays on electrodes that are not externally templated. The magnetic forces, including the Lorentz force and the magnetic gradient force, can generate a flow that brings electrolyte enriched with electroactive ions towards the cone tips, and thus may enhance the local mass transfer and support the conical growth.
Numerical studies on single diamagnetic (Cu) and ferromagnetic (Fe) cathodes of conical shape at mm length scale provide a basic understanding of the flow and the mass transfer at conical structures during electrodeposition in a uniform external magnetic field. It is found that beside the Lorentz force, the magnetic gradient force caused by the magnetization of the Fe cones can efficiently enhance conical growth. Working towards nano-sized cone arrays, upon shrinking the cone size we find that conical growth becomes less supported. Damping effects from neighboring cones and weaker electrolyte flow in general are weakening the mass transfer enhancements near the cone tip. However, the flow caused by the magnetic gradient force (Fe case) is clearly less affected than that caused by the Lorentz force (Cu case).
Despite the weaker flow effects when the cone size shrinks, a beneficial influence of the magnetic field on conical growth, especially for ferromagnetic deposits, can be stated also at small scales.

Correctly predicting the behaviour gas-liquid multiphase flows with numerical simulation tools is a highly complex task, especially when considering industrial scales. The most challenging task in that regard might be the large range of length scales of turbulent as well as of interfacial structures. Based on the two-fluid model, a hybrid methodology is developed with the goal to adaptively combine Euler-Euler and Volume-of-Fluid (VOF) simulation methods for statistical and scale-resolving representation of gas-liquid interfaces, respectively (Meller et al., 2021). With that approach, inevitably situations arise, where interfacial dynamics need to be predicted with VOF in combination with a particularly coarse grid resolution.
Low-pass filtering of the underlying two-fluid equations in this context reveals an unclosed sub-grid surface tension term, besides the convective and other unclosed terms (Meller et al., 2022). This contribution expresses the interfacial forces due to surface tension, which are not captured on a comparatively coarse computational grid. Different functional and structural closure models for that unclosed term are assessed in an a-posteriori fashion in case of a gas bubble rising in stagnant liquid. This contributes to an improved predictive power of the numerical model regarding large-scale interface and turbulent dynamics, even with low spatial resolution.