Publications Repository - Helmholtz-Zentrum Dresden-Rossendorf

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43660 Publications

Ferrous iron oxidation in the presence of antimonate at neutral pH: Mutual effects on iron mineral products and antimony sequestration

Wegner, L.; Burton, E. D.; McCammon, C.; Scheinost, A.; Planer-Friedrich, B.; Peiffer, S.; Hockmann, K.

Abstract

Antimony is a priority pollutant, whose mobility in redox-dynamic environments may be controlled by interactions with Fe(III) hydroxide minerals that form via Fe(II) oxidation. In this study, we examined the Fe(III) hydroxide precipitates and associated mechanisms of Sb(V) sequestration that result from Fe(II) oxidation in the presence of Sb(V) under neutral pH conditions. To achieve this aim, oxidation experiments were carried out in O2-saturated, Fe(II)-bearing solutions (buffered at pH 7) over a range of environmentally relevant Sb(V) concentrations (equivalent to Sb(V):Fe(II) molar ratios of 0, 0.01, 0.04, 0.1 and 0.25). Under these experimental conditions, Fe(II) oxidation occurred rapidly (within 20 minutes) causing associated removal of Sb(V) from solution via coprecipitation with the resulting Fe(III) hydroxides. At low Sb(V):Fe(II) ratios (< 0.1), lepidocrocite was the only Fe(III) mineral product of Fe(II) oxidation, whereas higher ratios resulted in formation of feroxyhyte. Both lepidocrocite and feroxyhyte retained Sb(V) within their crystal structure via Sb(V)-for-Fe(III) substitution. This mechanism of Sb(V) retention largely protected the solid-phase Sb(V) from release processes. Collectively, these results highlight the coupled role that interactions between Sb geochemistry and the Earth's near-surface Fe cycle can play in controlling both Fe(III) hydroxide mineralogy and Sb mobility.

Keywords: EXAFS; Feroxyhyte; Lepidocrocite; Mössbauer spectroscopy; Sb

Involved research facilities

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Permalink: https://www.hzdr.de/publications/Publ-41105


Defect-induced magnetic symmetry breaking in oxide materials

Brand, E.; Rosendal, V.; Wu, Y.; Tran, T.; Palliotto, A.; Maznichenko, I. V.; Ostanin, S.; Esposito, V.; Ernst, A.; Zhou, S.; Park, D.-S.; Pryds, N.

Abstract

Magnetic properties of crystalline solids are fundamental to a wide range of applications, capturing the attention of a vast scientific community. Thus, engineering magnetic order in materials such as ferromagnetism and antiferromagnetism holds great scientific and technological interest. Defects such as vacancies, interstitials, and dopants induce local perturbations within the crystal lattice. These perturbations locally disturb the entire symmetry of crystals, resulting in symmetry breaking. Oxides, in particular, exhibit intriguing properties when subjected to defects, which can lead to significant modifications in their structural, electronic, and magnetic properties. Such defects in non-magnetic oxides can induce magnetic symmetry breaking, leading to the formation of emergent magnetic domains and orderings. In this review, we focus on the recent progress in magnetic breaking symmetries in materials via defect engineering and present our perspectives on how these may lead to new understanding and applications.

Involved research facilities

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Permalink: https://www.hzdr.de/publications/Publ-41103


P2206 - Functionalized bisaminothiol derivatives, complexes with these bisaminothiol derivativesand use of said complexes as diagnostics and therapeutics

Fischer, S.; Ludwig, F.-A.; Ullrich, M.; Sihver, W.

Abstract

The invention relates to a compound of general formula I
(formula I)
wherein
A is a chelator selected from the group consisting of
k is independently at each occurrence 0, 1, or 2;
m is independently at each occurrence 1, 2, 3, 4 or 5;
n is independently at each occurrence 0, 1, 2 or 3;
p is independently at each occurrence 1, 2 or 3;
q is independently at each occurrence 1, 2 or 3;
u is independently at each occurrence 0 or 1;
X and Y are substituted or unsubstituted amino acids;
M 22 4 262 Application Text.docx
L is a bifunctional linker selected from group, consisting of
wherein v, x, and y are independently of each other 0, 1, 2, or 3 and z is 0, 1, 2 ,3, 4 or
5; and
R is H, methyl or ethyl.

  • Patent
    EP4282438 - Offenlegung 29.11.2023, Nachanmeldungen: WO

Permalink: https://www.hzdr.de/publications/Publ-41096


P2309 - Verfahren zur verbesserten, magnetisch unterstützten Abtrennung von Seltenen Erden

Lei, Z.; Ortmann, K.; Eckert, K.; Jähnigen, P.

Abstract

Die Erfindung betrifft ein Verfahren zur Abtrennung Seltener Erden aus einer festen oder einer wässrigen Phase mittels Lösungsmittelextraktion. Das Verfahren umfasst die Schritte: a) Kontaktieren einer wässrigen Phase (1) mit einer zweiten Phase (2), ausgewählt aus fester oder einer organischen flüssigen Phase, so dass aufgrund des Übergangs der Seltene Erden in Form von Seltenen-Erden-Ionen (3) von der zweiten oder in die zweite Phase ein Konzentrationsgradient innerhalb der wässrigen Phase entsteht, und b) Anlegen eines Magnetfelds (4) mittels eines Magneten (5) während des Kontaktierens an der Kontaktfläche, wobei das Magnetfeld so ausgerichtet wird, dass der Magnetfeldgradient antiparallel zum Konzentrationsgradienten der Seltenen Erden-Ionen in der wässrigen Phase ist und wobei das Produkt der Seltenen-Erden-abhängigen magnetischen Suszeptibilität χ und des Magnetfeldgradienten größer als 0,002 T2/m ist.

  • Patent
    DE102023122650 - Offenlegung 27.02.2025, Nachanmeldungen: WO

Permalink: https://www.hzdr.de/publications/Publ-41093


A perspective on rhamnolipid metal complexation for application in bioionflotation

Chakankar, M. V.; Pawliszak, P.; Pollmann, K.; Krasowska, M.; Rudolph, M.

Abstract

Abstract
Objective: Many industrial wastewater streams contain various base and critical metals, which have to be removed, from the point of view of both environmental and economic reasons. Ion flotation is a simple physicochemical separation process for such streams. The process requires addition of surface active chemicals such as frothers that generate foam and collectors that collect metal ions. The separation efficiency of ion flotation process is controlled by the collector surfactants. As a way towards green processes, ion flotation is being assessed for the use of environmentally friendly alternatives. In this context, there has been a recent surge of research on use of biosurfactants as flotation reagents. The primary interest of this research is to scrutinize the useability of biosurfactants as ecofriendly ionflotation reagents and provide an insight into metal complexation and selectivity. This work is a part of our research aiming to develop a fundamental understanding of biosurfactants metal interactions.
Rhamnolipids are a group of glycolipid type of biosurfactants containing one or two rhamnose sugars attached to two beta hydroxyl fatty acid chains and produced by various strains of Pseudomonas species. The properties of rhamnolipid as ion collectors, like surface and interfacial activity and metal complexation ability for various base and critical metals are investigated with dynamic surface tension studies and isothermal titration calorimetry (ITC), in order to advance their application in bioionflotation process.
Results: The influence of various metals ions (Ga, As, Al, Mn, Ni, Co and Li) on surface activity of rhamnolipid revealed significant impact. Presence of metals ions shifted the surface activity curve of rhamnolipid. This change in trend can be attributed to the complexation of rhamnolipid with metal ions that lead to longer diffusion at the sub-surface and then to interface resulting in higher surface ages. Further, the shifting of surface tension curves of rhamnolipid is different for various tested metals, with Al being farthest followed by Ga and other metals. However, the surface tension curve for rhamnolipid in presence of As and Li alone does not show this behavior suggesting no complexing interaction of rhamnolipid with these metal ions. The difference in shifting of the curves with different metals shows that such surface tension studies in presence and absence of ions could provide an indirect suggestion on the possible selectivity or preference for complexation between different metal ions by surface active agent. Additionally, the rhamnolipid-metal complexation was evaluated using ITC to determine the thermodynamic characterization of the interaction of rhamnolipid with metal ions. The results show high binding affinity for metals as Ga>Mn>Ni>Co, suggesting the complexation. Moreover, ITC data also showed that rhamnolipid did not interact with Li and As, thus supporting the surface tension results. We will also discuss experimental findings of recent interaction studies at the Synchrotron in Melbourne, Australia.
Conclusion: The role of rhamnolipid as ion collector in the ion flotation process was assessed in the current study. In particular, our results revealed that the rhamnolipid showed the high affinity towards Al and Ga followed by other base metals, whereas no interaction was observed with As and Li. Further, the binding affinity results from ITC supported the surface activity results. Overall, the proposed approach of studying the effect of metal ions on surface activity and determining the binding affinity using ITC enables a better description of the possible selectivity of metals in mixed metal solutions and can be used during the design of flotation experiments.

Keywords: Rhamnolipid; Metal complexation; Biosurfactants; Environmentally-friendly

  • Lecture (Conference)
    Jahrestreffen der DECHEMA/VDI-Fachgruppen Gasreinigung, Mechanische Flüssigkeitsabtrennung, Grenzflächenbestimmte Systeme und Prozesse 2025, 06.-07.03.2025, Frankfurt, Germany

Permalink: https://www.hzdr.de/publications/Publ-41088


P2310 - Wärmespeicher

Unger, S.; Hampel, U.

Abstract

Die Erfindung betrifft einen Wärmespeicher zum Speichern thermischer Energie, wobei der Wärmespeicher eine Speicherelement-Anordnung mit einem oder mehreren Kombinations-Wärmespeicherelementen aufweist, wobei jedes der Kombinations-Wärmespeicherelemente ein aus einem Festkörpermaterial bestehendes Festkörper-Wärmespeicherelement aufweist, in
dem ein oder mehrere mit einem Phasenwechselmaterial befüllte Hohlräume ausgebildet sind.

  • Patent
    DE102023123958 - Offenlegung 06.03.2025, Nachanmeldungen: WO

Permalink: https://www.hzdr.de/publications/Publ-41085


Data publication: Electrolyte spraying within H2 bubbles during water electrolysis

Bashkatov, A.; Bürkle, F.; Demirkır, Ç.; Ding, W.; Sanjay, V.; Babich, A.; Yang, X.; Mutschke, G.; Czarske, J.; Lohse, D.; Krug, D.; Büttner, L.; Eckert, K.

Abstract

Description of Data availability.zip:

The archive contains raw data necessary for reproducing all figures presented in the manuscript submitted as Electrolyte spraying within H2 bubbles during water electrolysis (also available as a pre-print at https://doi.org/10.48550/arXiv.2409.00515). Each folder within the archive includes a readme file detailing data included (e.g. images, electrochemical data, or velocity fields).

Keywords: raw data; electrolysis; bubble dynamics; hydrogen; Worthington jet; droplets injection; end-pinching; Marangoni effect; internal flow; electrolyte spraying; hydrogen evolution reaction

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Permalink: https://www.hzdr.de/publications/Publ-41084


Data publication: Measurement of liquid foam flow through a diverging nozzle

Skrypnik, A.; Lappan, T.; Knüpfer, L.; Ziauddin, M.; Arnal Tribaldos, I.; Shevchenko, N.; Heitkam, S.

Abstract

The hydrodynamic theory of pneumatic foam analytically predicts the advective transport of liquid by foam rising continuously in a vertical column or pipe, relying on cross-sectional averaging of the foam velocity and liquid fraction. This experimental study accumulates a database for assessing the pneumatic foam theory in a vertically aligned diverging nozzle, i.e. at increasing cross-sectional area in nominal flow direction. The velocity distribution of the flowing foam and its liquid fraction distribution were measured by means of X-ray, optical and electrical techniques in three different nozzles distinguished by their half angle θ = 5°, 10°, 20°. The experimental setup and the measurements are described in detail in Skrypnik et al. (https://www.hzdr.de/publications/Publ-41024).

  • X-ray radiography (XR) has measured the distribution of the liquid fraction (εXR) inside the nozzle as a two-dimensional projection, i.e. integrated in the X-ray beam direction.
  • X-ray particle tracking (XPTV) has measured the local velocity uT inside the nozzle, along the motion path of each tracer particle described by the radial (r) and vertical position (z) in consecutive frames. The velocity uT was normalised by the superficial gas velocity jg(z) = Qg / (π * R(z)2), with Qg denoting the gas flow rate of compressed air applied for foam generation, and R(z) denoting the radius of the cross-sectional area depending on the vertical position z. To compare different nozzles, the vertical position z was normalised by the total length L = 25 mm / tan(θ) of the nozzle depending on its half angle θ = 5°, 10°, 20°.
  • Optical PIV adapted to foam (FoamPIV) has measured the time-averaged velocity uW through the transparent wall of the nozzle, i.e. at the nozzle radius r = R(z) depending on the vertical position z. As described above, the velocity uW was normalised by the superficial gas velocity jg(z), and the vertical position z was normalised by the total length L of the nozzle.
  • Electrode pairs (EP) have measured the cross-sectional average values of the liquid fraction (εEP) upstream and downstream the nozzle, simultaneously to the X-ray radiographic measurement of the liquid fraction distribution (εXR) inside the nozzle.

The experimental data in this repository is structured into different folders and files as follows.

  • FoamNozzle_Overview.CSV gives an overview of all measurements runs, nozzles, and techniques.
  • Level 1 are folders classified by the measurement technique: 01_XR: X-ray radiography, 02_XPTV: X-ray particles tracking velocimetry, 03_FoamPIV: Optical PIV adapted to foam, 04_EP: Electrode pairs.
  • Level 2 are folders classified by the different nozzles, distinguished by the nozzle half angle θ = 5°, 10°, 20°, and divided into bottom and top part in the case of θ = 5°, 10°.
  • Level 3 are TIF and CSV files of measurement results.
    • 01_XR: Each TIF image shows the time-averaged distribution of the liquid fraction inside the nozzle; the liquid fraction (0 < εXR < 1) is indicated by the value of each pixel.
    • 02_XPTV: Each CSV file consists of three columns, namely the radial position (r, in mm), the normalised vertical position (z / L), and the normalised velocity (uT / jg(z)).
    • 03_FoamPIV: Each CSV file consists of two columns, namely the normalised vertical position (z / L), and the normalised velocity (uW / jg(z)).
    • 04_EP: Each CSV file consists of three columns, namely the cross-sectional average of the liquid fraction (0 < εEP < 1) downstream as well as upstream the nozzle, and the time (in s).

Keywords: Drainage; Liquid fraction; Particle tracking velocimetry; Particle image velocimetry; Pneumatic foam theory; X-ray radiography

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Permalink: https://www.hzdr.de/publications/Publ-41083


Dataset for ESFR-SIMPLE Task 3.3 (D3.3)

Fridman, E.

Abstract

This dataset contains the complimentary data for the deliverable D3.3:

  • Region- and batch-wise burnup data at EOEC in MWd/kg
  • DH data in Watts: up to 1.0E+07 sec for all 36 burnable materials described in Section ‎3.2
  • 3D power maps in Watts: SA-wise data subdivided into 19 axial layers
  • Detailed nuclide compositions of all burnable materials (number densities) at EOEC in #/barn‧cm.

Downloads

Permalink: https://www.hzdr.de/publications/Publ-41081


Extending and applying automated HERMES software publication workflows

Kernchen, S.; Meinel, M.; Druskat, S.; Fritzsche, M.; Pape, D.; Bertuch, O.

Abstract

Research software is an important output of research and must be published according to the FAIR Principles for Research Software. This can be achieved by publishing software with metadata under a persistent identifier. HERMES is a tool that leverages continuous integration to automate the publication of software with rich metadata. In this work, we describe the HERMES workflow itself, and how to extend it to meet the needs of specific research software metadata or infrastructure. We introduce the HERMES plugin architecture and provide the example of creating a new HERMES plugin that harvests metadata from a metadata source in source code repositories. We show how to use HERMES as an end user, both via the command line interface, and as a step in a continuous integration pipeline. Finally, we report three informal case studies whose results provide a preliminary evaluation of the feasibility and applicability of HERMES workflows, and the extensibility of the hermes software package.

Keywords: research software; software publication; software metadata; automation

Permalink: https://www.hzdr.de/publications/Publ-41080


Compared Experiences from Teaching Full-Semester Research Software Engineering Courses at Four German Universities

Bertrand, N.; Devkate, A.; Juckeland, G.; Linxweiler, J.; Peters, S.; Remus, S.; Schöning-Stierand, K.; Lamprecht, A.-L.

Abstract

Research Software Engineering has emerged as a critical discipline atthe intersection of software development and research with the aim of enhancingthe quality, reliability, and reproducibility of scientific software. In this paper wepresent a comparative analysis of the experiences gained from teaching full-semesterResearch Software Engineering (RSE) courses at four different universities in Ger-many. Despite its growing importance, there is limited literature on the pedagogicalapproaches and challenges encountered in teaching RSE courses, particularly at theuniversity level. This paper investigates and contrasts the contexts, designs, andexperiences of RSE courses offered at the TU Braunschweig, TU Dresden, Uni-versity of Hamburg and University of Potsdam. By synthesizing the experiencesand insights gleaned from these four universities, this study aims to provide valu-able guidance and best practices for educators seeking to develop or enhance RSEeducation initiatives.

Keywords: Research Software Engineering; Scientific Software Engineering; RSE Education; RSE Teaching

Permalink: https://www.hzdr.de/publications/Publ-41079


Recovering Knowledge from old Code

Erxleben, F.

Abstract

Imagine: A 30 year old Fortran code. 10K lines of three-letter variables, almost no commentary of varying correctness and no one left to remember how it works. Amazingly it is still in use - even though it is unclear how exactly it calculates what it calculates…

Somewhere buried in these dusty bits and bytes supposedly lies an algorithm that promises to be better than the tools that a research group have available, faster and more precise.

The HIFIS RSE-consulting team was approached to help with investigating this software, unlocking its hidden secrets and coming up with a way to deal with this kind of "inherited software", because we can be sure: There is a lot more where that came from.

In this talk we will present how we approach this problem, the plan, the steps already taken, the challenges encountered, what worked (or at least looks promising) and what didn't.

Keywords: RSE; Legacy Software; FORTRAN 77; HIFIS

Permalink: https://www.hzdr.de/publications/Publ-41077


Anomalous Quasielastic Scattering Contribution in the Centrosymmetric Multi-q Helimagnet SrFeO3

Andriushin, N. D.; Grumbach, J.; Kulbakov, A. A.; Tymoshenko, Y. V.; Onykiienko, Y. A.; Firouzmandi, R.; Cheng, E.; Granovsky, S.; Skourski, Y.; Ollivier, J.; Walker, H. C.; Kocsis, V.; Büchner, B.; Keimer, B.; Doerr, M.; Inosov, D. S.; Peets, D. C.

Abstract

Centrosymmetric compounds which host three-dimensional topological spin structures comprise a distinct subclass of materials in which multiple-q magnetic order is stabilized by anisotropy and bond frustration in contrast to the more common path of antisymmetric exchange interactions. Here we investigate static and dynamic magnetic properties of the cubic perovskite SrFeO3—a rare example of a centrosymmetric material hosting two types of topological spin textures: skyrmionlike and hedgehoglattice phases. Our detailed magnetization and dilatometry measurements describe the domain selection processes and phase transitions in SrFeO3. Spin excitations are investigated using inelastic neutron scattering for all three zero-field phases. In the higher-temperature ordered phases, high-energy magnons increasingly lose coherence, so that spin fluctuations are dominated by a distinct quasielastic component at low energies. We anticipate that this could be generic to symmetric helimagnets in which the chiral symmetry is spontaneously broken by the magnetic order.

Involved research facilities

  • High Magnetic Field Laboratory (HLD)

Permalink: https://www.hzdr.de/publications/Publ-41076


Giant quantum oscillations in thermal transport in low-density metals via electron absorption of phonons

Bermond, B.; Wawrzynczak, R.; Zherlitsyn, S.; Kotte, T.; Helm, T.; Gorbunov, D.; Gu, G.; Li, Q.; Janasz, F.; Meng, T.; Menges, F.; Felser, C.; Wosnitza, J.; Grushin, A.; Carpentier, D.; Gooth, J.; Galeski, S.

Abstract

Oscillations of conductance observed in strong magnetic fields are a striking manifestation of the quantum dynamics of charge carriers in solids. The large charge carrier density in typical metals sets the scale of oscillations in both electrical and thermal conductivity, which characterize the Fermi surface. In semimetals, thermal transport at low-charge carrier density is expected to be phonon dominated, yet several experiments observe giant quantum oscillations in thermal transport. This raises the question of whether there is an overarching mechanism leading to sizable oscillations that survives in phonon-dominated semimetals. In this work, we show that such a mechanism exists. It relies on the peculiar phase-space allowed for phonon scattering by electrons when only a few Landau levels are filled. Our measurements on the Dirac semimetal ZrTe5 support this counterintuitive mechanism through observation of pronounced thermal quantum oscillations, since they occur in similar magnitude and phase in directions parallel and transverse to the magnetic field. Our phase-space argument applies to all low-density semimetals, topological or not, including graphene and bismuth. Our work illustrates that phonon absorption can be leveraged to reveal degrees of freedom through their imprint on longitudinal thermal transport.

Involved research facilities

  • High Magnetic Field Laboratory (HLD)
  • Open Access Logo Proceedings of the National Academy of Sciences of the United States of America 122(2025)10, 2408546122
    DOI: 10.1073/pnas.2408546122
    arXiv: https://arxiv.org/abs/2402.17022

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Permalink: https://www.hzdr.de/publications/Publ-41074


Superconducting critical temperature elevated by intense magnetic fields

Wu, Z.; Chen, H.; Weinberger, T. I.; Cabala, A.; Graf, D. E.; Skourski, Y.; Xie, W.; Ling, Y.; Zhu, Z.; Sechovsky, V.; Valiska, M.; Grosche, F. M.; Eaton, A. G.

Abstract

Below a critical temperature Tc, superconductors transport electrical charge without dissipative energy losses. The application of a magnetic field B generally acts to suppress Tc, up to some critical field strength at which Tc -> 0 K. Here, we investigate magnetic field–induced superconductivity in high-quality specimens of the triplet superconductor candidate UTe2 in pulsed magnetic fields up to B = 70 T. Strikingly, we find that this material has a higher Tc when B > 40 T (Tc ≈ 2.4 K) than it does for B = 0 T (Tc = 2.1 K). This observation points to a fundamentally distinct mechanism for the formation of superconductivity at high B in Ute2 compared to the case of B = 0 T.

Involved research facilities

  • High Magnetic Field Laboratory (HLD)
  • Open Access Logo Proceedings of the National Academy of Sciences of the United States of America 122(2025)2, 2422156122
    DOI: 10.1073/pnas.2422156122

Permalink: https://www.hzdr.de/publications/Publ-41073


Host–guest chemistry on living cells enabling recyclable photobiocatalytic cascade

Zhang, J.; Batista, V. F.; Hübner, R.; Karring, H.; Wu, C.

Abstract

Combining chemical and whole-cell catalysts enables sustainable chemoenzymatic cascade reactions. However, their traditional combination faces challenges in catalyst recycling and maintaining cell viability. Here, we introduce a supramolecular host–guest strategy that efficiently attaches photocatalysts to bacterial cells, facilitating recyclable photobiocatalysis. This method involves attaching a cationic polyethylenimine (PEI) polymer, functionalized with beta-cyclodextrin (beta-CD), to E. coli cells. The polymer attachment is biocompatible and protective, safeguarding the cells from harsh conditions such as UV radiation and organic solvents, without causing cell death. Additionally, the presence of beta-CD imparts a plug-and-play capability to the cells, enabling the straightforward integration of guest photocatalysts – specifically anthraquinone – onto the cell surface through host–guest interactions. This effective combination of cellular and chemical catalysts promotes efficient photobiocatalytic cascades and supports the photocatalyst's recycling and reuse. This supramolecular system thus represents a promising platform for advancing photobiocatalysis in cascade synthesis.

Involved research facilities

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Permalink: https://www.hzdr.de/publications/Publ-41072


Protein Modifications and Ionic Strength Show the Difference in Protein-Mediated and Solvent-Mediated Regulation of Biomolecular Condensation

Czajkowski, A.; Udayabanu, A.; Raj, M.; Pulibandla, L. C. P.; Tursunovic, M.; Jahnel, M.; Adams, E.

Abstract

Biomolecular condensation is an important mechanism of cellular compartmentalization without membranes. Formation of liquid-like condensates of biomolecules involves protein-protein interactions working in tandem with protein-water interactions. The balance of these interactions in condensate-forming proteins is impacted by multiple factors inside of a living organism. This work investigates the effects of post-translational modifications (PTMs) and salt concentration as two such perturbing factors on the protein Fused in Sarcoma (FUS), an RNA binding protein. The protein was obtained from two expression systems differing by their capability to add PTMs to the protein, bacterial and insect cell. Attenuated total reflection Terahertz spectroscopy is used to probe the solvation behavior in condensates formed from FUS protein with and without PTMs at 100 mM and 2.5 M KCl. The results show that while PTMs impact the phase-separating propensity, they do not alter protein solvation in the condensate. On the other hand, salt concentration was found to alter the stiffness of the water hydrogen bond network. These findings have implications for biomolecular condensates chemistry, showing that condensate molecular organization is perturbed by fluctuations in solvent properties.

Keywords: biomolecular condensates; protein solvation

Permalink: https://www.hzdr.de/publications/Publ-41071


How to find and evaluate good research software - a field report

Konrad, U.; Bruch, C.

Abstract

The Helmholtz Association strongly promotes the field of research software engineering. Among other activities, the Helmholtz Research Software Directory (RSD) was developed and the Helmholtz Software Award was launched. But these great initiatives have raised questions:

How exactly do you find the great software?
How do you encourage the development teams to publish it and describe it in such a way that not only insiders understand what it's all about?
How can international reviewers be recruited and how can they evaluate software applications in areas they are not specialized on?
How do you compare and evaluate software that differs greatly not only in terms of technical aspects, but also in terms of maturity, user community and target groups?

The Helmholtz RSD has developed into a successful repositoiry and is increasingly bringing added value to software developers and scientists. The first Helmholtz Software Prize 2023 was awarded in three categories and the applications for the second call 2024 have been received and are being reviewed. At the same time the topic of evaluating research results, including data and software, has recently become increasingly important. Here too, the evaluation of research software is playing an important role.

In this presentation, the experiences and results of these processes will be presented in detail. The topics mentioned and still in flux are of growing importance for universities, research institutions and also the NFDI consortia! These experiences in this still relatively new field are therefore valuable information and a basis for discussions in the RSE community!

Keywords: Research Software Engineering; RSE; Research Software Repository; Software Award; Evaluation

Involved research facilities

  • Data Center

Permalink: https://www.hzdr.de/publications/Publ-41070


Tungsten oxide thin films probed by depth-resolved positron annihilation spectroscopy

Burwitz, V. V.; Kärcher, A.; Mathes, L.; Book, A.; Paul, N.; Schwarz-Selinger, T.; Butterling, M.; Hirschmann, E.; Liedke, M. O.; Wagner, A.; Unsal, E.; Cuniberti, G.; Hugenschmidt, C.

Abstract

Tungsten oxide (WOx) films grown on tungsten (W) are characterized by depth-resolved Doppler-broadening spectroscopy (DBS) and positron-annihilation lifetime spectroscopy (PALS) as primary analytical methods. The WOx films are prepared on W(111) monocrystals using either exposure to air, electrochemical, or thermal oxidation procedures, chosen according to the desired thickness. We calculate the lifetime of positrons in the bulk of WOx and in different types of vacancies using the atomic superposition (AtSup) method. These give the size required for a multivacancy in WOx needed for it to be identifiable by PALS. In our experiments, we identified a distinct positron lifetime of 325 p⁢s in the thin oxide layer on W exposed to air. This value overlaps with that of multivacancy sites in W and, hence, should be taken into account in future PALS studies of radiation-induced defects in W.

Keywords: Defects; Radiation damage; Vacancies; Oxides; Thin films; Transition metal oxides; Doppler broadening spectroscopy; Positron annihilation spectroscopy; X-ray diffraction

Involved research facilities

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Permalink: https://www.hzdr.de/publications/Publ-41069


Data publication: Free volume and nonlinear viscoelasticity in supercrystalline nanocomposites: A nanoindentation driven modelling analysis

Yan, C.; Hirschmann, E.; Geers, G. D. M.; Giuntini, D.

Abstract

This data set consists of positron annihilation lifetime measurements generated at a conventional measuring station with a Na-22 source.

Keywords: Supercrystals; Creep; Nonlinear viscoelasticity; Free volume; Positron annihilation lifetime spectroscop

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Permalink: https://www.hzdr.de/publications/Publ-41068


Free volume and nonlinear viscoelasticity in supercrystalline nanocomposites: A nanoindentation driven modelling analysis

Yan, C.; Hirschmann, E.; Geers, G. D. M.; Giuntini, D.

Abstract

Supercrystalline nanocomposites (SCNCs) are a new class of hybrid materials consisting of organically functionalized nanoparticles that are arranged into periodic architectures, featuring multi-functional properties. While their mechanical behavior is starting to be assessed, the time-dependent aspects thereof, and especially creep, remain unexplored. This lack of understanding is an obstacle towards future implementation of SCNCs into devices. It is therefore imperative not only to capture experimentally the creep behavior of SCNCs, but also to develop models that accurately predict its evolution. Here, a model is proposed to capture the nanoindentation creep behavior of SCNCs, using both rheological models and free volume theory. The creep compliance derived from the rheological model shows a stress-dependent trend, indicating nonlinear viscoelasticity. The presence of free volume is experimentally detected in SCNCs via positron annihilation lifetime spectroscopy. It decreases in size with increasing degrees of crosslinking of the organic phase, a phenomenon attributed to the shrinkage of superlattices. The creep compliance is predicted by introducing a shift factor to account for the evolution of the relaxation time caused by the change in free volume. A free volume-based creep model is proposed to predict the creep behavior of SCNCs, and its applicability is validated through new nanoindentation creep tests at varying loads.

Keywords: Supercrystals; Creep; Nonlinear viscoelasticity; Free volume; Positron annihilation lifetime spectroscop

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Permalink: https://www.hzdr.de/publications/Publ-41067


Technetium - The Unknown Center of the Periodic Table

Strub, E.; Badea, D.; Bruns, J.; Frontera, A.; Mayordomo, N.; Sakhonenkova, A.; Roca Jungfer, M.; Wickleder, M.; Yong, C.; Zegke, M.

Abstract

It took 78 years from Mendeleev’s proposal of an existence of “eka-manganese” (1869) until it was finally named as technetium (Tc) in 1937. Another 78 years have passed since then. This provides a good occasion to pinpoint what we know and what we still do not know of this radioelement. Technetium is placed near the center of the Periodic Table, in the center of the groups 6, 7, and 8. Some chemical properties of the elements surrounding technetium show trends within the columns or along the rows of the Periodic Table, but a consistent interpretation of these trends is lacking as long as the knowledge on technetium remains incomplete. This is especially remarkable as, on the other hand, the isotope 99mTc is applied on a daily basis in nuclear medicine. The aim of this paper is to review the fundamental understanding of technetium chemistry, mostly focusing on the research of the last decade,
its implications, and its future perspectives. These developments show a picture of growing connections between physicochemical data, fundamental inorganic chemistry, organometallic and coordination chemistry, computational chemistry, and geochemistry

Keywords: Technetium; Perspectives; geochemistry; coordination chemistry; organometallic chemistry; inorganic chemistry; computational chemistry

Permalink: https://www.hzdr.de/publications/Publ-41065


Helmholtz Quality Indicators for Software– & Data Products

Meistring, M.; Juckeland, G.

Abstract

The Helmholtz Association is adding a new indicator for research data and research software publications to its reporting. A working group with members from all Helmholtz centers has been working on defining this new indicator and the Helmholtz general assembly has approved their suggestion in its fall meeting of 2024. In this talk the indicator as well as the ideas behind it and the methods to collect the information are introduced. The indicator is based on a maturity model looking at various aspects of a research software publication, thus also providing value to the authors of the software and research software researchers as it makes multiple aspects of research software as a scientific publication itself visible.

  • Open Access Logo Invited lecture (Conferences)
    6. Helmholtz Research Software Forum, 12.-13.02.2025, Jülich, Deutschland
  • Open Access Logo Invited lecture (Conferences) (Online presentation)
    39th HIRSE Seminar, 21.02.2025, Jülich, Deutschland
  • Open Access Logo Lecture (Conference)
    deRSEcon25, 25.-27.02.2025, Karlsruhe, Deutschland

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Permalink: https://www.hzdr.de/publications/Publ-41064


Verification of nTRACER/COBRA-TF with Serpent2/SUBCHANFLOW for full core high fidelity high-resolution analysis of VVERs

Papadionysiou, M.; Bilodid, Y.; Fridman, E.; Pautz, A.; Hursin, M.

Abstract

This work illustrates the verification of the nTF/CTF multi-physics core solver for full core VVER-1000 analysis and more specifically the X2 benchmark. The coupled code system is compared with a solver of similar capabilities, Serpent2/SCF. The differences in the models and in the methods employed by the multi-physics core solvers are discussed in detail. Their impact is studied by comparing nTF/CTF with Serpent2/SCF for single VVER assembly calculations with different modeling options. Then, the two code systems are compared for the Hot Full Power (HFP) state of the X2 benchmark, which includes two phases, one with default modeling options for all codes, and one with consistent modeling options. Overall, nTF/CTF presents good agreement with Serpent2/SCF, in terms of power, temperature and boron concentration. The existing discrepancies can be partly attributed to the different methods and correlations used by the codes involved in the coupled code systems.

Keywords: High-resolution; Multi-physics; nTRACER; COBRA-TF; VVER

Involved research facilities

  • Data Center

Permalink: https://www.hzdr.de/publications/Publ-41062


Enhancing froth flotation of PEMEL catalyst particles for recycling by adding sodium hexametaphosphate

Ahn, S.; Rudolph, M.

Abstract

This study investigates the effect of dispersant on the froth flotation of representative polymer electrolyte membrane water electrolyzer (PEMEL) catalyst particles, specifically TiO2 and carbon black. Since the used material showed significant difference in their (de) wetting behavior, mechanical processes such as froth flotation can achieve selective separation of the particles. In the previous research on liquid-liquid particle separation, SHMP significantly improved the dispersion ability of TiO2, alleviating stabilization at the interface and enhancing its recovery. Hence, sodium hexametaphosphate (SHMP) is proposed to address the challenge of hydrophilic TiO2 entrainment in the froth phase.
Both pristine particles and ionomer-containing particles were prepared for the test. The behaviour of the synthesized particles represents that of real particles from the cell in the system. The amphiphilic structure of ionomer significantly influenced particle separation based on wettability differences. Moreover, to overcome the limitation of ultrafine particles in froth flotation, a hydrophobic double emulsion was used to selectively agglomerate carbon black particles.
SHMP improved the recovery and grade of both particles effectively by stabilizing TiO2 in the particle dispersion and preventing its undesired recovery in the froth phase.
While many studies focus on chemical processes for PGMs recovery, the approach with mechanical separation methods present a more sustainable recycling strategy for PEM water electrolyzers.

  • Lecture (Conference)
    Jahrestreffen der DECHEMA/VDI-Fachgruppen Gasreinigung, Mechanische Flüssigkeitsabtrennung, Grenzflächenbestimmte Systeme und Prozesse, 06.-07.03.2025, Frankfurt am Main, Germany

Permalink: https://www.hzdr.de/publications/Publ-41057


hMtMrFoam - Heat and Mass Transport Multiregion Solver

Personnettaz, P.; Weber, N.

Abstract

The software repository contains a solver to model heat and mass transfer in several regions with OpenFOAM. Heat transport is modelled in the full domain, while fluid dynamics is solved in each layer separately. Mass transfer is simulated only in the bottom layer. The dataset further contains a testcase of a Li-Bi liquid metal battery.

Related publications

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Permalink: https://www.hzdr.de/publications/Publ-41056


NAPMIX - Nuclear, Astroparticle, and Particle Physics Metadata Integration for eXperiments

Knodel, O.; Mistry, A. K.

Abstract

The NAPMIX project aims to create a cross-domain metadata schema tailored for the Nuclear, Astro, and Particle Physics communities. By leveraging local and international connections, including Open Science initiatives like EOSC, EURO-LABS, and the ESCAPE Cluster, NAPMIX will foster synergies with related fields, enhancing cross-domain interoperability. The schema will facilitate the sharing and long-term findability of datasets, representing a breakthrough in Open Science within experimental physics. Community feedback will be integral to refining the schema, ensuring its relevance and sustainability.

Keywords: Metadata; ESCAPE; NAPMIX; Nuclear Physics; Astroparticle Physics; Particle Physics; Ontology

Involved research facilities

  • Felsenkeller
  • Open Access Logo Invited lecture (Conferences)
    1st OSCARS Annual General Meeting, 03.-04.03.2025, Rome, Italy

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Permalink: https://www.hzdr.de/publications/Publ-41055


Data publication: Development of [99mTc]TcO-ABX474: Design, Synthesis and biological Evaluation of PSMA-binding Technetium-99m radioligands for SPECT Imaging of Prostate Cancer

Lis, C.; Ludwig, F.-A.; Fischer, S.; Ullrich, M.; Lankau, H.-J.; Sihver, W.; Gündel, D.; Joseph, D.; Meyer, C.; Kopka, K.; Pietzsch, J.; Brust, P.; Hoepping, A.

Abstract

Daten zur Radiosynthese der Tracer, einschließlich analytische Daten Daten zu Stabilitätsprüfungen der Tracer Daten zur biologischen Evaluierung (Autoradiographie)

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Permalink: https://www.hzdr.de/publications/Publ-41054


Data publication: OECD/NEA AI/ML Benchmark on Critical Heat Flux—HZDR Results

Nikitin, E.

Abstract

Results obtained in the framework of OECD/NEA Benchmark on Artificial Intelligence and Machine Learning for Scientific Computing in Nuclear Engineering—Phase 1: Critical Heat Flux

Keywords: Critical Heat Flux; CHF; OECD/NEA Benchmark; Artificial Intelligence; Look-up Table

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Permalink: https://www.hzdr.de/publications/Publ-41051


Data publication: Generating structured foam via flowing through a wire array

Skrypnik, A.; Knüpfer, L.; Trtik, P.; Lappan, T.; Ziauddin, M.; Heitkam, S.

Abstract

The structure of liquid foam is generally considered random and isotropic. However, when foam flows past a set of wires, an inhomogeneous liquid fraction distribution, or layering, can be observed within the bulk. This dataset presents neutron radiography data of foam flowing past a set of thin metal wires. During the experiments, the gas flow rate and bubble size were varied. Additionally, a dataset for foam flow past a single wire is included for reference.


The folder includes initial data for the manuscript "Generating structured foam via flowing through a wire array".

Folder includes:

01_scripts scripts used for the data processing
02_rawdata Initial neutron imaging data (.tif images)
03_evaluation folder with MATLAB scripts used for data analysis

LABBOOK Experimental labbook explaining the experimental sequence.
Protocol The Neutron imaging protocol with the data of neutron source and image resolution

The data processing is shown for the O1 bubble generator. It includes:
1. MASK_... script used to define the cell walls and determine the mask, used further for the liquid fraction calculation.
2. N13_INIT... scritps to define normalised image, which further used to determine liquid fraction distribution
3. POST_BOT... scripts used to postprocess the data: define Liquid fraction distribution and DFT of those distributions.

Note: 

1. The data were analysed at two positions: bottom (0) and top (100), meaining at the wire grid and 100 mm downstream the grid. To this end, mask should be calculated also for the top part of the nozzle, if needed, as shown in the presented examples.

2. The data for the empty cell were calculated for the foam flow through the cell with a single thin wire. Teh data were extracted
in the ROI before the wire (run 553-557).

3. Data processing was performed as suggested in https://doi.org/10.1371/journal.pone.0210300

Keywords: Foam; Neutron imaging; Radiography

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Permalink: https://www.hzdr.de/publications/Publ-41043


The Data Management Evolution in the Photon and Neutron Community (PaNOSC)

Knodel, O.

Abstract

The presentation refers to the advances in research data management developed for the photon and neutron communities (PaN) in the context of the two EU projects PaNOSC and ExPaNDS. Both projects played a crucial role in advancing open science within the European research landscape.

Keywords: PaNOSC; ExPANDS; PaN; Photon and Neutron; Data Management

  • Open Access Logo Invited lecture (Conferences)
    Love Data Week at OSL, 14.02.2025, Open Science Lab, SLUB Dresden, Germany
    DOI: 10.5281/zenodo.14887431

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Permalink: https://www.hzdr.de/publications/Publ-41041


Accessing neodymium in end-of-life magnet materials using innovative leaching and selective solvent extraction

Kelottijärvi, L.; Kelly, N.; Ebert, D.; Väisänen, A. O.; Patil, A. B.

Abstract

Rare earth elements (REEs) have become necessary in a wide range of high-technology applications due to their unique magnetic, electronic and optical properties. The materials are used in consumer electronics, and they play a big role in the renewable energy technologies. Although REEs are relatively abundant in the Earth’s crust, low concentrations of single elements in minerals makes economically viable extraction challenging. With the growth of green technologies, global demand for REEs can be expected to rise significantly, increasing the need for efficient recycling and recovery of these materials.
NdFeB permanent magnets contain notable amount of REEs like neodymium, praseodymium, dysprosium and gadolinium, therefore making end-of-life magnets a valuable waste stream. The development of effective recycling processes optimizes the return of valuable metals, minimizes the need for primary mining of REE and reduces Europe's dependence on imports of critical raw materials. In this study, we investigate the leaching of waste magnet powders with mineral and organic acids in dependence on typical parameters like leaching time and acid concentration. Since the pregnant leaching solution (PLS) contains a significant amount of Fe(III), an innovative solvent extraction route for the selective separation of Fe(III) is developed. It is important to mention that, Fe(III) removal is universal and critical issue in primary and secondary processing of rare earth metals.
Optimization of the relevant process parameters contact time, pH, A/O ratio and anion system for single element and mixed solutions of Nd(III) and Fe(III) in the extraction system NdX3–FeX3–acid/amine–kerosene is carried out. Extraction yields of 80–95 % for Fe(III) and 10–30 % for Nd(III) in pHeq. of 1.8 indicate a possible separation of Fe(III) from a PLS. As a result of further investigations such like the development of extraction isotherms, process conditions for continuous experiments with laboratory mixer-settler system are set. In addition, the method is tested for solution containing organic acid.

Involved research facilities

  • Metallurgy Technical Centre
  • Lecture (Conference)
    Jahrestreffen der DECHEMA-Fachgruppe Extraktion, 19.-20.02.2025, Aachen, Deutschland

Permalink: https://www.hzdr.de/publications/Publ-41032


Revision of the CNO cycle: Rate of ¹⁷O destruction in stars

Rapagnani, D.; Straniero, O.; Imbriani, G.; Aliotta, M.; Ananna, C.; Barile, F.; Barbieri, L.; Bemmerer, D.; Best, A.; Boeltzig, A.; Broggini, C.; Bruno, C. G.; Caciolli, A.; Campostrini, M.; Casaburo, F.; Cavanna, F.; Ciani, G. F.; Colombetti, P.; Compagnucci, A.; Corvisiero, P.; Csedreki, L.; Davinson, T.; Depalo, R.; Di Leva, A.; Elekes, Z.; Ferraro, F.; Formicola, A.; Fülöp, Z.; Gervino, G.; Gesuè, R. M.; Gyürky, G.; Guglielmetti, A.; Gustavino, C.; Junker, M.; Lugaro, M.; Marigo, P.; Marsh, J.; Masha, E.; Menegazzo, R.; Mercogliano, D.; Paticchio, V.; Piatti, D.; Prati, P.; Rigato, V.; Robb, D.; Sidhu, R. S.; Skowronski, J.; Szücs, T.; Zavatarelli, S.

Abstract

Background: The CNO cycle powers core H burning, in stars with M > 1.2M(solar), and shell H burning, during the advanced evolutionary phases. Therefore, the uncertainties affecting the reaction rates of proton captures on C, N, and O isotopes limit our understanding of stellar evolution and nucleosynthesis.

Purpose: We aim to develop a general and self-consistent tool for the calculation of nuclear reaction rates and their uncertainties, starting from available experimental data. As a longer term plan, we intend to use this tool to revise the proton-capture reactions of the CNO cycle for which new experimental data are or will be available in the next future.

Method: The general procedure consists of R-matrix cross section calculations based on available measurements of the relevant nuclear parameters (energies, widths, strengths of known resonances, interference patterns, etc.), coupled to a Monte Carlo procedure to evaluate the global reaction rate error.
Results: A first application of this method to 17O(p,γ)18F and 17O(p,α)14N, the reactions that determine the 17O destruction in stellar interiors where the CNO cycle is active, is presented. These two reactions also allow us to test the multichannel and multilevel capabilities of the R-matrix method. In the temperature range of hydrostatic H burning (T < 100 MK), we confirm that the median rates are up to a factor of 2 higher than those suggested in reaction rate libraries commonly used in stellar model calculations. In this temperature range, the 17O destruction mainly proceeds through the 17O(p,α)14N channel, whose rate is known within ±20% (95% C.L.).

Conclusions: Based on current stellar models of red giant stars, we show that this uncertainty produces a 10% variation on the predicted 16O/17O abundance ratio. Other uncertainties, such as those affecting the 17O production rate, i.e., the 16O(p,γ)17F reaction, have a stronger impact on this theoretical prediction, a fact that motivates further experimental investigations of the 17O production channel.

Keywords: Nuclear Astrophysics; CNO Cycle; R-Matrix Analysis; Astrophysical Reaction Rate

Permalink: https://www.hzdr.de/publications/Publ-41022


2025 roadmap on 3D nanomagnetism

Gubbiotti, G.; Barman, A.; Ladak, S.; Bran, C.; Grundler, D.; Huth, M.; Plank, H.; Schmidt, G.; van Dijken, S.; Streubel, R.; Dobrovoloskiy, O.; Scagnoli, V.; Heyderman, L.; Donnelly, C.; Hellwig, O.; Fallarino, L.; Jungfleisch, B.; Farhan, A.; Maccaferri, N.; Vavassori, P.; Fischer, P.; Tomasello, R.; Finocchio, G.; Clérac, R.; Sessoli, R.; Makarov, D.; Sheka, D.; Krawczyk, M.; Gallardo, R.; Landeros, P.; d’Aquino, M.; Hertel, R.; Pirro, P.; Ciubotaru, F.; Becherer, M.; Gartside, J.; Ono, T.; Bortolotti, P.; Fernández-Pacheco, A.

Abstract

The transition from planar to three-dimensional (3D) magnetic nanostructures represents a significant advancement in both fundamental research and practical applications, offering vast potential for next-generation technologies like ultrahigh-density storage, memory, logic, and neuromorphic computing. Despite being a relatively new field, the emergence of 3D nanomagnetism presents numerous opportunities for innovation, prompting the creation of a comprehensive roadmap by leading international researchers. This roadmap aims to facilitate collaboration and interdisciplinary dialogue to address challenges in materials science, physics, engineering, and computing. The roadmap comprises eighteen sections, roughly divided into three parts. The first section explores the fundamentals of 3D nanomagnetism, focusing on recent trends in fabrication techniques and imaging methods crucial for understanding complex spin textures, curved surfaces, and small-scale interactions. Techniques such as two-photon lithography (TPL) and focused electron beam-induced deposition enable the creation of intricate 3D architectures, while advanced imaging methods like electron holography and synchrotron x-ray tomography provide nanoscale spatial resolution for studying magnetization dynamics in three dimensions. Various 3D magnetic systems, including coupled multilayer systems, artificial spin-ice, magneto-plasmonic systems, topological spin textures, and molecular magnets are discussed. The second section introduces analytical and numerical methods for investigating 3D nanomagnetic structures and curvilinear systems, highlighting geometrically curved architectures, interconnected nanowire systems, and other complex geometries. Finite element methods are emphasized for capturing complex geometries, along with direct frequency domain solutions for addressing magnonic problems. The final section focuses on 3D magnonic crystals and networks, exploring their fundamental properties and potential applications in magnonic circuits, memory, and spintronics. Computational approaches using 3D nanomagnetic systems and complex topological textures in 3D spintronics are highlighted for their potential to enable faster and more energy-efficient computing.

Keywords: nanomagnetism; three-dimensional nano structures; fabrication techniques; imaging methods; analytical methods; computational approaches

Permalink: https://www.hzdr.de/publications/Publ-41020


Data publication: Towards Personalized Immunotherapeutic Drug Monitoring with Multiplexed Extended Gate FET Biosensors

Nguyen-Le, T.-A.; Neuber, C.; Cela, I.; Janićijević, Ž.; Rodrigues Loureiro, L. R.; Hoffmann, L.; Feldmann, A.; Bachmann, M.; Baraban, L.

Abstract

Measurement datasets collected from extended gate Field Effect Transistor biosensor and radioactivity measurements

Keywords: immunosensor; field-effect-transistor; immunotherapy; precision medicine; point-of-care; extended gate; biosensor

Involved research facilities

  • PET-Center

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Permalink: https://www.hzdr.de/publications/Publ-41016


BMBF-Verbundprojekt RADEKOR: Speziation und Transfer von Radionukliden im Menschen unter besonderer Berücksichtigung von Dekorporationsmitteln. Teilprojekt A

Barkleit, A.

Abstract

Gelangen Radionuklide (RN) über den Nahrungspfad zum Menschen, können sie eine radio- und chemotoxische Gefahr darstellen. Um die Gesundheitsrisiken bei einer oralen Aufnahme von RN mit der Nahrung präzise abschätzen und wirksame Dekontaminationsverfahren anwenden zu können, ist ein Prozessverständnis der Biokinetik der RN auf zellulärer und molekularer Ebene zwingend notwendig. In dem Verbundprojekt wurden für die orale Inkorporation ausgewählter RN neben quantitativen Ausscheidungsanalysen und biokinetischen Modellierungen die molekulare Speziation der RN im Verdauungstrakt und ihre Wechselwirkungen mit Zellen des Verdauungs- und Ausscheidungssystems in An- und Abwesenheit gängiger und neuer potentieller Dekorporationsmittel untersucht. Ziel dieser Arbeiten war es, mit einem tieferen Prozessverständnis der RN-Wechselwirkungen im Verdauungstrakt auf molekularer und zellulärer Ebene zur Erstellung eines präzisen biokinetischen Modells und zur Entwicklung bzw. Verbesserung von nuklidspezifischen Dekontaminations-strategien beizutragen.

  • Open Access Logo Wissenschaftlich-Technische Berichte / Helmholtz-Zentrum Dresden-Rossendorf; HZDR-137 2025
    ISSN: 2191-8708, eISSN: 2191-8716

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Permalink: https://www.hzdr.de/publications/Publ-41014


[Tc(NO)Cl₂(PPh₃)₂(CH₃CN)] and Its Reactions with 2,2′-Dipyridyl Dichalcogenides

Sawallisch, T. E.; Rupf, S. M.; Abdulkader, A.; Ernst, M. J.; Roca Jungfer, M.; Abram, U.

Abstract

The sparingly soluble technetium(I) complex [Tcᴵ(NO)Cl₂(PPh₃)₂(CH₃CN)] (1) slowly dissolves during reactions with 2,2′-dipyridyl ditelluride, (2-pyTe)₂, 2,2′-dipyridyl diselenide, (2-pySe)₂, or 2,2′-dipyridyl disulfide, (2-pyS)₂, under formation of deeply colored solutions. Blue (Te compound) or red solids (Se compound) of the composition [{Tcᴵ(NO)Cl₂(PPh₃)₂}₂{µ₂-(2-pyE)₂}], E = Te (3), Se (4), precipitate from the reaction solutions upon addition of toluene. They represent the first technetium complexes with dichalcogenides. While [{Tcᴵ(NO)Cl₂(PPh₃)}₂{µ₂-(2-pyTe)₂}] (3) is the sole product, a small amount of a second product, [Tcᴵᴵ(NO)Cl₂(PPh₃)(2-pySe)] (5), was obtained from the respective mother solution of the reaction with the diselenide. From the corresponding reaction between 1 and (2-pyS)₂, the technetium(II) compound, [Tcᴵᴵ(NO)Cl₂(PPh₃)(2-pyS)] (6), could be isolated exclusively. The products were studied by single-crystal X-ray diffraction and spectroscopic methods including ⁹⁹Tc NMR for the technetium(I) products and EPR spectroscopy for the Tc(II) complexes. The experimental results are accompanied by DFT considerations, which help to rationalize the experimental observations.

Keywords: technetium; nitrosyls; dichalcogenides; 2-Pyridyl chalcogenolates; NMR; EPR; X-ray diffraction

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Permalink: https://www.hzdr.de/publications/Publ-41011


Data publication: Hybrid Isentropic Twin Stars

Carlomagno, J. P.; Contrera, G. A.; Grunfeld, A. G.; Blaschke, D.

Abstract

Data for the figures of the publication on "Hybrid Isentropic Twin Stars" in ASCII format.

Keywords: hot neutron stars; color superconductivity; thermal twin stars; quark confinement; Seidov criterion

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Permalink: https://www.hzdr.de/publications/Publ-41007


Cluster-Freezeout_PLB860

Blaschke, D.; Liebing, S.; Röpke, G.; Dönigus, B.

Abstract

Data for particle production in heavy-ion collisions allow the quantum statistical analysis of the parameters for chemical freeze-out of hadron species with special emphasis on light nuclear clusters. Tables are provided for the freeze-out lines in the plane of temperature and chemical potential in ASCII format. These lines, together with abundances of alpha particle clusters are given also in the temperature-density plane using both linear and logarithmic density scale. The data have been obtained in July-August 2024 within a collaboration between 4 authors of the publication in Phys. Lett. B 860(2025) 139206, who represent 5 Institutions: University of Wroclaw, HZDR/CASUS, University of Rostock, TU Bergakademie Freiberg and University of Frankfurt (Main).

Keywords: Light clusters; Mott transition; Beth-Uhlenbeck; Chemical freeze-out; Heavy-ion collisions

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Permalink: https://www.hzdr.de/publications/Publ-41006


Forschungsbewertung im Wandel: Ansätze für Anerkennung und FAIRness bei Helmholtz

Meistring, M.; Genderjahn, S.; Juckeland, G.; Ferguson, L. M.; Pampel, H.; Vleugel, M.

Abstract

Die zunehmende Digitalisierung und Open-Science-Praktiken fordern neue Wege zur Bewertung wissenschaftlicher Leistungen. Eindimensionale Metriken wie Zitationszahlen reichen nicht aus, um die Vielfalt des Forschungsoutputs angemessen zu erfassen. Seit 2022 arbeitet eine Task Group der Helmholtz-Gemeinschaft mit Vertreter:innen aus den 18 Helmholtz-Zentren an einem mehrdimensionalen Qualitätsindikator für Forschungsdaten- und -Software-Publikationen. Dieser Ansatz soll die Qualität in der Wissenschaft steigern.

Permalink: https://www.hzdr.de/publications/Publ-41005


In ovo model for investigation of novel PET antibodies: first experience with [⁸⁹Zr]Zr-nSucDf-Denosumab and [⁸⁹Zr]Zr-nSucDf-Atezolizumab

Benčurová, K.; Gündel, D.; Kieler, M.; Friske, J.; Helbich, T. H.; Hacker, M.; Balber, T.; Mitterhauser, M.; Philippe, C.; Brandt, M.

Abstract

Introduction
The chick embryo (in ovo) is a promising model for preselection of radiotracer candidates yet
the behaviour of PET antibodies (Ab) in ovo remains largely unexplored. [⁸⁹Zr]Zr-DfDenosumab was recently developed to target receptor activator of nuclear kappa-B ligand
(RANKL) [1] and denosumab is authorised for treatment of osteoporosis and cancer-related
bone diseases [2]. Using [⁸⁹Zr]Zr-nSuc-Df-Denosumab ([⁸⁹Zr]Deno) as a model Ab, we aimed
to explore the potential of the in ovo model for development of immuno PET agents;
[⁸⁹Zr]Zr-nSuc-Df-Atezolizumab [3] ([⁸⁹Zr]Atezo) was used for comparison.
Methods
Fertilised chicken eggs were incubated as published previously [4]. [⁸⁹Zr]Deno and
[⁸⁹Zr]Atezo were synthesised according to Bensch et al. [3]. PET/MRI was performed on
embryo development day (EDD) 17 and 18 using a 9.4 Tesla MR BioSpec® scanner with a
dedicated PET insert and a PET-compatible coil (Bruker Biospin) 1 h 20 min, 7 h, and 23 h p.i.
of [⁸⁹Zr]Deno (n = 4) or 19 h p.i. of [⁸⁹Zr]Atezo (n = 2). Chick embryonic organs were
delineated based on anatomical MR information. The metabolic stability of [⁸⁹Zr]Deno was
assessed for chick embryonic serum and gallbladder by size exclusion high-pressure liquid
chromatography and instant thin-layer chromatography.
Results/Discussion
Zr-labelled antibodies were synthesised with a radiochemical yield >70% and >98%
radiochemical purity. [⁸⁹Zr]Deno initially accumulated mainly in the chick embryos’ heart,
spleen and liver; no uptake was detected in the brain. The activity in the liver and the increase
in gallbladder-associated activity indicate hepatobiliary excretion. In addition, [⁸⁹Zr]Deno
appears to be partially excreted via kidneys into the allantois (Fig. 1). The in ovo
biodistribution profile was similar to that in mice [1] but occurred much faster. Higher
amounts (n = 2, 9.3 vs. 1.1 mg/kg bw) resulted in slower metabolism/clearance in ovo.
Metabolic analysis 6 h p.i. revealed a release of free Zr in the gallbladder (40%) and the
formation of larger protein aggregates in serum (50%). The tracer’s cross-reactivity for
chicken RANKL, which is ~60% homologous to the mammalian receptor [5], was not
investigated. The biodistribution of [⁸⁹Zr]Atezo 19 h p.i. was highly comparable to [⁸⁹Zr]Deno
23 h p.i. (Fig. 2).
Conclusion
The biodistribution profile of [⁸⁹Zr]Deno reflected that observed in mice [1], albeit in a much
shorter time frame and was also highly comparable to [⁸⁹Zr]Atezo approx. 1 day p.i. This
study provides insights into what is probably a non-targeted, physiological behaviour of
antibodies in ovo and indicates the potential of the in ovo model as a high throughput
platform for the development of immuno PET agents.
Novelty
To the best of our knowledge, this is the first investigation of the biodistribution and stability
of ⁸⁹Zr-labelled antibodies in the in ovo model.
Impact
The rapid biodistribution observed in the in ovo model highlights its potential for an initial
high throughput testing of novel PET antibodies.
Disclosure
Neither I nor any of my co-authors have any financial interests or relationships to disclose in
relation to the subject of this presentation.
References
[1] Dewulf, Jonatan, et al. ‘Immuno-PET molecular imaging of RANKL in cancer’, Cancers 2021, 13(9): 2166
[2] European Medicines Agency (EMA). ‘Xgeva (denosumab): an overview of Xgeva and why it is authorised in the
EU’, EMA/302853/2018. https://www.ema.europa.eu/en/documents/overview/xgeva-epar-medicineoverview_en.pdf
[3] Bensch, Frederike, et al. ‘ Zr-atezolizumab imaging as a non-invasive approach to assess clinical response to
PD-L1 blockade in cancer’, Nat Med 2018, 24(12): 1852-8
[4] Benčurová, Katarína, et al. ‘CAM-xenograft model provides preclinical evidence for the applicability of
[⁶⁸Ga]Ga-Pentixafor in CRC imaging’, Cancers 2022, 14(22): 5549
[5] Sutton, Kate MC, et al. ‘The functions of the avian receptor activator of NF-κB ligand (RANKL) and its receptors,
RANK and osteoprotegerin, are evolutionarily conserved’, Dev Comp Immunol 2015, 51(1): 170-84

Keywords: in ovo; chick embryo; Atezolizumab; Denosumab; PET/MRI

  • Lecture (Conference)
    EMIM 2025, 11.-14.03.2025, Bilbao, Spain

Permalink: https://www.hzdr.de/publications/Publ-40994


A Description Framework for Research Software and Metadata Publication Policies

Pape, D.; Bertuch, O.; Huste, T.; Knodel, O.; Meinel, M.; Kernchen, S.; Heeb, N.; Meeßen, C.

Abstract

The curation of software metadata safeguards their quality and compliance with institutional software policies. Moreover, metadata that was enriched with development and usage information can be used for evaluation and reporting of academic KPIs. Software CaRD ("Software Curation and Reporting Dashboard"; ZT-I-PF-3-080), a project funded by the Helmholtz Metadata Collaboration (HMC), develops tools to support the curation and reporting steps of the research software publication process. The dashboard will present metadata collected by the HERMES workflow in a graphical user interface, assess compliance with a configurable set of policies, and highlight issues and breaches. It will be usable both standalone and in a CI/CD context.

As a first step in the project, and as a foundation for the curation dashboard, a description format for software publication policies had to be developed. Our solution takes an approach that allows for configuration at different levels of abstraction: Low level building blocks describe metadata (e.g., CodeMeta) validation in terms of the Shapes Constraint Language (SHACL). A higher-level configuration language allows users to reuse and parameterize these components. This makes Software CaRD usable for RSEs, management, and policy makers, and it allows for customization that facilitates usage in different research institutions.

This poster submission presents our approach, showcases example policies, and gives guidance to users of the application.

Keywords: metadata; policies; rdf; shacl; software-publication

  • Open Access Logo Poster
    deRSE25 - 5th Conference for Research Software Engineering in Germany, 25.-27.02.2025, Karlsruhe, Deutschland
    DOI: 10.5281/zenodo.14844059

Permalink: https://www.hzdr.de/publications/Publ-40958


Advanced 2D XRF imaging of uranium oxidation states using HERFD at the U M4 edge

Bazarkina, E.; Lau, K. V.; Chappaz, A.; Bastrakov, E.; Etschmann, B.; Brugger, J.; Marshall, M.; Meyer, F. M.; Boreham, C. J.; Amidani, L.; Kvashnina, K.

Abstract

Uranium is found in various types of rocks. HERFD-XRF imaging at the U M4 edge is a novel non-destructive technique that visualizes the distribution of U (IV), (V), and (VI) oxidation states at concentration levels ranging from ppm to wt%, offering unprecedented insights into uranium habitat and valence.

Keywords: uranium; sedimentary rocks; organic-rich shales; phosphorite grainstone; HERFD-XRF; U M4 edge HERFD; HERFD-XAS; pentavalent uranium

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Permalink: https://www.hzdr.de/publications/Publ-40951


Drastic enhancement of electronic correlations induced by hydrogen insertion in the cerium intermetallic compound CeFeSi

Sourd, J.; Vignolle, B.; Gaudin, E.; Burdin, S.; Tencé, S.

Abstract

We report a comparative study of two cerium-based intermetallic compounds: CeFeSi with an anti-PbFCl type structure, and CeFeSiH with a ZrCuSiAs type structure. The latter is obtained from CeFeSi through hydrogen insertion. Our results are based on x-rays, transport, thermodynamic and magnetic measurements. While the tetragonal structure with P4/nmm symmetry remains unchanged after hydrogen insertion, the thermodynamic, magnetic, and transport properties change drastically. On the one hand, CeFeSi behaves as a Pauli paramagnet with a small Sommerfeld coefficient, indicating the absence of 4f electron physics. On the other hand, our study shows that CeFeSiH exhibits strong magnetic fluctuations with a magnetic transition at 3.5 K, and coherent Kondo-lattice heavy-fermion features.

Permalink: https://www.hzdr.de/publications/Publ-40950


Origin of the non-Fermi-liquid behavior in CeRh2As2

Khanenko, P.; Hafner, D.; Semeniuk, K.; Banda, J.; Lühmann, T.; Bärtl, F.; Kotte, T.; Wosnitza, J.; Zwicknagl, G.; Geibel, C.; Landaeta, J. F.; Khim, S.; Hassinger, E.; Brando, M.

Abstract

Unconventional superconductivity in heavy-fermion systems appears often near magnetic quantum critical points (QCPs). This seems to be the case also for CeRh2As2 (Tc ≈ 0.31 K). CeRh2As2 shows two superconducting (SC) phases, SC1 and SC2, for a magnetic field along the c axis of the tetragonal unit cell, but only the SC1 phase is observed for a field along the basal plane. Furthermore, another ordered state (phase I) is observed below T0 ≈ 0.48 K whose nature is still unclear: Thermodynamic and magnetic measurements pointed to a nonmagnetic multipolar state, but recent μSR and nuclear quadrupole resonance/nuclear magnetic resonance (NMR) experiments have clearly detected antiferromagnetic (AFM) order below T0. Also, quasi-two-dimensional AFM fluctuations were observed in NMR and neutron-scattering experiments above T0. The proximity of a QCP is indicated by non-Fermi-liquid (NFL) behavior observed above the ordered states in both specific heat C(T )/T ∝ T−0.6 and resistivity ρ(T ) ∝ √T. These T dependencies are not compatible with any generic AFM QCP. Because of the strong magnetic-field anisotropy of both the SC phase and phase I, it is possible to study a field-induced SC QCP as well as a phase-I QCP by varying the angle α between the field and the c axis. Thus, by examining the behavior of the electronic specific-heat coefficient C(T )/T across these QCPs, we can determine which phase is associated with the NFL behavior. Here, we present low-temperature specific-heat measurements taken in a magnetic field as high as 21 T applied at several angles α.We observe that the NFL behavior very weakly depends on the field and the angle α, a result that is at odds with observations in standard magnetic QCPs. This suggests a nonmagnetic origin of the quantum critical fluctuations.

Involved research facilities

  • High Magnetic Field Laboratory (HLD)

Permalink: https://www.hzdr.de/publications/Publ-40949


Formation of varying dendritic morphologies in a directionally solidifying Ga-In-Bi alloy

Shevchenko, N.; Budenkova, O.; Chichignoud, G.; Eckert, S.

Abstract

Solidification of a ternary Ga-In-Bi alloy under a thermal gradient ≈ 1.8K/mm with a moderate cooling rate 0.01K/s was performed with in-situ observation using X-ray radiography. Similar to the solidification of a binary Ga-In alloy, buoyancy convection developed in the system due to a large density difference between the alloy components. Yet, it was found that contrary to the binary system, the primary arms of the ternary solid structure not only adapt their velocity to the variation of the local concentration ahead of their tips but may also change continuously or abruptly their growth direction. A closer look on the system revealed that the deviation of the growth direction happened via branching. Alternatively, some of primary arms demonstrated multiple splitting and intense yet retarded growth of the secondary arms.

Keywords: Directional solidification; Ternary alloys; Morphology; In-situ; X-ray radiography

Permalink: https://www.hzdr.de/publications/Publ-40948


Data publication: Uncovering the Dynamic CO2 Gas Uptake Behaviour of CALF-20 (Zn) under Varying Conditions via Positronium Lifetime Analysis

Elsherif, A. G. A.; Bon, V.; Hirschmann, E.; Butterling, M.; Wagner, A.; Zaleski, R.; Kaskel, S.

Abstract

Raw data of positron annihilation, gas adsorption, in situ PXRD, and SEM images

Keywords: CALF-20; CO2 capture and storage; environmental gas uptake; positron annihilation

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Permalink: https://www.hzdr.de/publications/Publ-40946


Uncovering the Dynamic CO2 Gas Uptake Behaviour of CALF-20 (Zn) under Varying Conditions via Positronium Lifetime Analysis

Elsherif, A. G. A.; Bon, V.; Hirschmann, E.; Butterling, M.; Wagner, A.; Zaleski, R.; Kaskel, S.

Abstract

Carbon dioxide (CO2) is a major greenhouse gas contributing to global warming. Adsorption in porous sorbents offers a promising method to mitigate CO2 emissions by capturing and storage. The zinc-triazole-oxalate-based metal-organic framework CALF-20 demonstrates high CO2 capacity, low H2O affinity, and low CO2 adsorption heat, enhancing energy efficiency while maintaining stable performance over multiple adsorption/desorption cycles. This study examines CO2 adsorption in CALF-20. Using the combination of positron annihilation lifetime spectroscopy (PALS), in situ-Powder X-ray Diffraction (PXRD) analyses, and gas adsorption experiments, we elucidate the CO2 adsorption mechanisms in CALF-20 under various temperatures, and humidity levels, simulating ambient conditions. The variable temperature PALS experiments demonstrate that CO₂ molecules are spatially localized within the CALF-20 cages, leaving temperature- and pressure-dependent gaps between them. PALS results indicate that CO2 initially spreads across cage centers, 1D chains, and ultimately adheres to pore walls. Interestingly, positronium intensity, which increases with CO₂ adsorption pressure, closely aligns with the Langmuir-Freundlich isotherm and reflects gas uptake behaviour. Moreover, we explore the adsorption characteristics of relative humidity (RH) and humid CO₂ in CALF-20. At low RH in pure humidity run, water molecules are sparsely adsorbed within the framework, forming isolated clusters or small oligomers with minimal hydrogen bonding. Above 35% RH, water molecules begin to form interconnected hydrogen-bond networks that fill the cages, significantly altering the material's free volumes. In humid CO₂ experiment, competitive interactions between CO₂ and water are observed, where CO₂ initially disrupts the propagation of water, but at higher RH, water molecules form more extensive hydrogen-bond networks. This competition influences both the cage and inter-granular spaces, with the latter becoming larger and more flexible as water fills the framework. The synergy between in situ-PALS, in situ-PXRD, and gas adsorption techniques provides a comprehensive understanding of CALF-20's potential for efficient CO2 capture under varying environmental conditions.

Keywords: CALF-20; CO2 capture and storage; environmental gas uptake; positron annihilation

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Permalink: https://www.hzdr.de/publications/Publ-40945


Use Case: HZDR — NAPMIX at the Felsenkeller Laboratory

Boeltzig, A.; Knodel, O.

Abstract

At the kick-off meeting of the OSCARS-funded NAPMIX project, the HZDR's use case, the Felsenkeller laboratory, was presented. In addition to the actual experiment, data publication of both metadata and the real data sets and a possible embedding in the HZDR publication ecosystems such as SciCat and RODARE were introduced.

Keywords: Felsenkeller; Data Management; OSCARS; NAPMIX; Metadata

Involved research facilities

  • Felsenkeller
  • Open Access Logo Invited lecture (Conferences)
    NAPMIX Project Kick Off 2025, 05.-06.02.2025, Darmstadt, Deutschland

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Permalink: https://www.hzdr.de/publications/Publ-40943


European Workshop on Photocathodes for Particle Accelerator Applications 2024 – Summary of Oral Contributions

Xiang, R.; Ryzhov, A.; Jones, L.; Noakes, T. C. Q.; Monaco, L.; Sertore, D.; Baylac, M.; Kühn, J.; Ganter, R.

Abstract

The European Workshop on Photocathodes for (particle) Accelerator Applications (EWPAA) brings together experts in the field of photocathode electron sources for use in particle accelerators with the aim of sharing their knowledge and latest research and development progress in this crucial field of particle accelerator science.
The workshop is convened every other year, and is thus complementary to the P3 workshop (Photocathode Physics for Particle accelerators) run in the USA. Consequently, there is a workshop focusing on photocathodes for particle accelerator applications convened every year, either in Europe or the USA.
The EWPAA 2024 is the 5th meeting in this workshop series. The event was hosted by the ELBE Department at the HZDR Helmholtz–Zentrum Dresden–Rossendorf in Dresden between September 17th and 19th. Photocathodes have been developed, studied and utilized in SRF
photoinjectors at the ELBE center for more than 20 years.
The programme was organised with 7 working groups, with each oral contribution assigned to the most appropriate group. Details of the event and the scientific programme can be found at the website https://events.hifis.net/event/1255/overview. The proceedings present the main points raised by each of the speakers in their oral presentations.
The Local Organizer Committee acknowledges the EWPAA Scientific Programme Members for their support in drafting and delivering the agenda and thanks them for their help in organizing and achieving such a successful event.
The organizers also gratefully acknowledge the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) for their part-funding of the workshop cost under DFG Project No. 545151564.
The next workshop in 2026 will be hosted by the Irène Joliet-Curie Laboratory (IJCLAb) at Orsay in Paris.

  • Open Access Logo Wissenschaftlich-Technische Berichte / Helmholtz-Zentrum Dresden-Rossendorf; HZDR-135 2025
    ISSN: 2191-8708, eISSN: 2191-8716

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Permalink: https://www.hzdr.de/publications/Publ-40942


Towards reproducible perfusion MRI analysis: the ISMRM Open Science Initiative for Perfusion Imaging

van Houdt, P.; Bell, L.; Dickie, B.; Mutsaerts, H.; Petr, J.; Sourbron, S.; Suzuki, Y.

Abstract

To improve reproducibility and increase harmonization in
MRI perfusion imaging, a community-led initiative was launched in
2019 to promote open science for perfusion imaging (OSIPI). An
initial set of resources have been developed that are useful for sci-
entists working with perfusion MRI data.

Involved research facilities

  • PET-Center

Permalink: https://www.hzdr.de/publications/Publ-40941


The effect of BBB-ASL intravoxel transit time on perfusion and water exchange time modeling in gliomas

Turhan, G.; Cetin, A. I.; Padrela, B. E.; Mahroo, A.; Konstandin, S.; Hoinkiss, D. C.; Breutigam, N. J.; Keil, V.; Danyeli, A. E.; Ozduman, K.; Eickel, K.; Mutsaerts, H. J.; Petr, J.; Gunther, M.; Dincer, A.; Ozturk Isik, E.

Abstract

The Blood Brain Barrier ASL (BBB-ASL) model, incor-
parates intra-voxel transit time (ITT), evaluates BBB integrity. This
study investigated the impact of including ITT on water exchange
time (Tex) and CBF maps in gliomas. Fitting ITT in the model
resulted in lower CBF and Tex values in tumor regions.

Involved research facilities

  • PET-Center

Permalink: https://www.hzdr.de/publications/Publ-40940


Tissue-specific T2 BBB-ASL in Meningiomas

Cetin, A. I.; Turhan, G.; Padrela, B.; Mahroo, A.; Konstandin, S.; Honkiss, D. C.; Breutigam, N.-J.; Keil, V.; Barkhof, F.; Danyeli, A. E.; Özduman, K.; Pamir, N.; Eickel, K.; Mutsaerts, H. J.; Petr, J.; Günther, M.; Dincer, A.; Ozturk-Isik, E.

Abstract

BBB-ASL can assess vascular permeability. This study
aimed to evaluate cerebral blood flow (CBF) and water exchange time
(Tex) in meningiomas using tissue-specific T2 BBB-ASL. Tex
decreased in the tumor. This study showed that using mean regional
T2 values might miss the heterogeneity in the tumor.

Involved research facilities

  • PET-Center
  • Open Access Logo Contribution to proceedings
    40th Annual Scientific Meeting of ESMRMB, 02.10.2024, Barcelona, Spain
    DOI: 10.1007/s10334-024-01191-6
  • Open Access Logo Poster
    40th Annual Scientific Meeting of ESMRMB, 02.10.2024, Barcelona, Spain

Permalink: https://www.hzdr.de/publications/Publ-40939


Hemodynamic changes in developing pediatric brain measured with single- and multi-delay arterial spin labeling

Prysiazhniuk, Y.; Petr, J.; Alexander, S.; Armindo, R. D.; Otáhal, J.; Kynčl, M.; Moseley, M.; Tong, E.; Zhao, M. Y.

Abstract

We investigate age-related hemodynamic changes in
children’s brains using single- and multi-delay ASL MRI. Significant
differences in perfusion quantification between these approaches
highlight age-dependent variations.

Involved research facilities

  • PET-Center
  • Open Access Logo Poster
    40th Annual Scientific Meeting of ESMRMB, 02.10.2024, Barcelona, Spain
  • Open Access Logo Contribution to proceedings
    40th Annual Scientific Meeting of ESMRMB, 02.10.2024, Barcelona, Spain
    DOI: 10.1007/s10334-024-01191-6

Permalink: https://www.hzdr.de/publications/Publ-40938


Triangular-shaped Cu–Zn–In–Se-based nanocrystals with narrow near infrared photoluminescence

Bora, A.; Fu, N.; Saha, A.; Prudnikau, A.; Hübner, R.; Bahmani Jalali, H.; Di Stasio, F.; Gaponik, N.; Lesnyak, V.

Abstract

Tunable optical properties exhibited by semiconductor nanocrystals (NCs) in the near infrared (NIR) spectral region are of particular interest in various applications, such as telecommunications, bioimaging, photodetection, photovoltaics, etc. While lead and mercury chalcogenide NCs do exhibit exemplary optical properties in the NIR, Cu–In–Se (CISe)-based NCs are a suitable environment-friendly alternative to these toxic materials. Several reports of NIR-emitting (quasi)spherical CISe NCs have been published, but their more complex-shaped counterparts remain rather less explored. The emerging anisotropic nanomaterials have gained significant interest owing to their unique optical properties arising due to their specific shape. While several examples of non-spherical Cu–In–S-based NCs have been reported, examples of CISe-based anisotropic NCs are rather scarce, and those with intensive photoluminescence (PL) are not yet developed. In this work, we present a one-pot approach to synthesize quaternary Cu–Zn–In–Se (CZISe) triangular NCs with intensive PL in the NIR region. The NCs synthesized exhibit tetragonal crystal structure and, depending on the reaction conditions, are single triangular particles or stacks of triangular blocks of varied lateral sizes but rather uniform thickness. The synthesis involves the formation of In2Se3 seeds with subsequent incorporation of copper and growth of triangular CISe NCs, followed by the incorporation of zinc and the growth of a ZnS shell. Importantly, the PL band widths of the final core/shell heterostructured NCs are narrow, down to 102 meV, which is a rarely observed characteristic for this class of materials and can be attributed to their anisotropic shape and the absence of thickness and compositional inhomogeneities of their building blocks. The PL of the CZISe/ZnS NCs can be tuned in the range of 1082-1218 nm reaching a quantum yield of up to 40% by varying their size and composition. To the best of our knowledge, this is the farthest and the narrowest PL achieved for CISe-based NCs so far, which widens application perspectives of this material in NIR LEDs, bioimaging, and photovoltaics.

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Permalink: https://www.hzdr.de/publications/Publ-40937


Atomic structure and electronic properties of Janus SeMoS monolayers on Au(111)

Picker, J.; Ghorbani Asl, M.; Schaal, M.; Kretschmer, S.; Otto, F.; Gruenewald, M.; Neumann, C.; Fritz, T.; Krasheninnikov, A.; Turchanin, A.

Abstract

Janus SeMoS monolayers (MLs) are synthetic 2D materials with unique electronic properties, as theory predicts, but their experimental exploration has been hindered by the low-quality of the samples. Here we report a synthesis of high-quality Janus MLs on gold substrates by thermal exchange reaction taking place at the ML/Au(111) interface. The synthesized Janus SeMoS MLs were characterized by complementary techniques, and the insights into the topography and electronic properties of the system were obtained. Specifically, due to the lattice mismatch with the Au(111), the moiré pattern with a periodicity of 2.9 nm was observed, a precise experimental determination of the lattice constant of Janus SeMoS of 3.22 ± 0.01 Å and the measured spin-orbit splitting at the K point of the valence band was found to be 170 ± 15 meV matching well the results of the density functional theory calculations.

Keywords: Janus TMDs; 2D materials; moiré; CVD

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Permalink: https://www.hzdr.de/publications/Publ-40936


Pressure drop and flooding points of droplet separators at relevant fluid properties

Döß, A.; Schubert, M.; Kryk, H.; Flegiel, F.; Hampel, U.

Abstract

Der Mitriss von Tropfen durch die aufsteigende Dampfphase in Trennkolonnen beeinträchtigt die Trennleistung, Energieeffizienz und Produktqualität erheblich und kann den Betrieb nachgeschalteter Apparate stören. Effiziente Tropfenabscheidung ist daher entscheidend für die Einsparung von Energie und Ressourcen. Zur verlässlichen Modellierung der Abscheidung bei realen Stoffsystemen ist eine Vorhersage mitgerissener Tropfenspektren, Druckverluste sowie der Flutpunkte entscheidend. Verfügbare Experimentaldaten für Tropfenabscheider wie Gestricke, Trägheitsabscheider oder Füllkörper decken jedoch nur einen unzureichenden Teil realer Geometrien und Stoffwerte ab. Insbesondere relevant sind Stoffwerte, die zur Bildung von Kleinsttropfen (< 5 μm) beitragen oder ein Benetzungsverhalten hervorrufen, welches kaum durch gängige Ersatzsysteme wie z. B. Wasser/Luft abgebildet werden kann. Darüber hinaus werden wichtige Einflussfaktoren wie Tropfengrößen und geometrische Parameter der Abscheider in gängigen Modellen bisher ignoriert. Dies führt häufig zu kostenintensiven, überdimensionierten Anlagen und großen Sicherheitsmargen.
In der TERESA-Forschungsanlage am Helmholtz-Zentrum Dresden-Rossendorf wird ein Kältemittelkreislauf mit dem Arbeitsmedium dient 3M™ Novec 649™ betrieben. Bei unterschiedlichen Druckniveaus werden relevante Fluidstoffwerte realisiert: Oberflächenspannungen unter 10 mN/m, hohe Dampfdichten (18 bis 170 kg/m³) bei gleichzeitig großen Dichteunterschieden zur Flüssigphase (887 bis 1450 kg/m³). Durch eine Flash-Verdampfung treten Dampf und Flüssigphase im Gleichstrom in einen vertikalen Testabscheider (DN 300 x 2,3 m) ein, so dass F-Faktoren bis 6 Pa0,5 realisiert werden können. Zusätzlich können über Düsen gezielt Tropfenspektren in die Zweiphasenströmung aufgegeben werden. Die in die Tropfenabscheider eingetragenen Tropfenspektren werden durch ein Strömungsmikroskop erfasst. Die Analyse der Flutpunkte und die Bilanzierung des Mitrisses erfolgt stromabwärts der Abscheider durch Erfassung aller notwendigen Flüssigkeitsströme.
In diesem Beitrag werden Untersuchungen mit verschieden Gestrickabscheidern vorgestellt. Dies umfasst die geometrische Charakterisierung und experimentellen Bestimmung von Porosität, trockenem Druckverlust und Flutpunkten für relevante Stoffwerte. Ein auf Basis dieser Daten entwickeltes praxistaugliches Modell wird ebenso präsentiert, bei dem viskose und turbulente Effekte beim Druckverlust berücksichtigt werden. Zudem wurden die Flutpunkte mehrerer Gestricke in der TERESA-Versuchsanlage für drei verschiedene Stoffeigenschaften-Kombinationen analysiert. Die Ergebnisse werden mit bestehenden Vorhersagemethoden wie dem Sherwood-Diagramm und der K-Wert-Methode verglichen.
Die Arbeiten im Rahmen des Projektes GeTReal werden durch das Bundesministerium für Wirtschaft und Klimaschutz (BMWK) über die Arbeitsgemeinschaft industrieller Forschungsvereinigungen „Otto von Guericke“ e.V. (AiF) gefördert (IGF-Vorhaben: 01IF22594N).

Keywords: Droplet separation; Wire mesh demisters; Pressure drop; Thermal separation

Involved research facilities

  • TOPFLOW Facility
  • Lecture (Conference)
    Jahrestreffen der DECHEMA/VDI-Fachgruppe Fluidverfahrenstechnik, 03.-05.02.2025, Bochum, Deutschland

Permalink: https://www.hzdr.de/publications/Publ-40935


RBS Spectra: "Temperature Effects of Nuclear and Electronic Stopping Power on Si and C Radiation Damage in 3C-SiC"

Kucal, E.; Józwik, P.; Mieszczynski, C.; Heller, R.; Akhmadaliev, S.; Dufour, C.; Czerski, K.

Abstract

RBS channeling spectra measured at the 2MV Van-de-Graaff accelerator with 1.7 MeV He ions. The measured silicon carbide samples were previously irradiated with Si and C ions at different ion energies and different temperatures at 3 MV and 6 MV tandem accelerators. The backscattered He ions were detected by a silicon surface barrier detector at an angle of 170◦.

For each sample, random spectra were recorded by tilting a sample at angles θ and ϕ of −4◦ off the normal to the surface and consequently changing one of them within the range (−4◦, +4◦) with a step of 0.2◦, while the other one was fixed at −4◦ or +4◦, respectively. Such random measurements also allow a high-precision alignment of the sample along the ion beam by the indication of the main crystallographic planes. The sample orientation for the measurements in channeling mode is determined by the values of the theta and phi angles corresponding to the intersection of the crystallographic planes. RBS/C analysis allows the evaluation of disorder after irradiation. The crystalline quality of an as-grown sample was evaluated as the ratio of the backscattered yield of an aligned pristine spectrum to that of the random spectrum.

The results show that annealing and repair effects are important for the prediction of radiation damage in SiC.

Keywords: radiation damage; stopping power; Rutherford backscattering; ion channeling

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Permalink: https://www.hzdr.de/publications/Publ-40932


EURAD state-of-the-art report: development and improvement of numerical methods and tools for modeling coupled processes in the field of nuclear waste disposal

Claret, F.; Prasianakis, N. I.; Baksay, A.; Lukin, D.; Pepin, G.; Ahusborde, E.; Amaziane, B.; Bátor, G.; Becker, D.; Bednár, A.; Béreš, M.; Bérešová, S.; Böthi, Z.; Brendler, V.; Brenner, K.; Březina, J.; Chave, F.; Churakov, S. V.; Hokr, M.; Horák, D.; Jacques, D.; Jankovský, F.; Kazymyrenko, C.; Koudelka, T.; Kovács, T.; Krejčí, T.; Kruis, J.; Laloy, E.; Landa, J.; Ligurský, T.; Lipping, T.; López-Vázquez, C.; Masson, R.; Meeussen, J. C. L.; Mollaali, M.; Mon, A.; Montenegro, L.; Pisani, B.; Poonoosamy, J.; Pospiech, S. I.; Saâdi, Z.; Samper, J.; Samper-Pilar, A.-C.; Scaringi, G.; Sysala, S.; Yoshioka, K.; Yang, Y.; Zuna, M.; Kolditz, O.

Abstract

The Strategic Research Agenda (SRA; https://www.ejp-eurad.eu/publications/eurad-sra) of the European Joint Programme on Radioactive Waste Management (EURAD; https://www.ejp-eurad.eu/) describes the scientific and technical domains and sub-domains and knowledge management needs of common interest between EURAD participant organizations. Theme number 7 is entitled “Performance assessment, safety case development and safety analyses.” A list of research and development priorities and activities of common interest to be addressed within EURAD for theme 7 have been established. Amongst others, the Understanding and modelling of multi-physical Thermo-Hydro-Mechanical-Chemical coupled processes (THMC) occurring in radioactive waste disposal is a major and permanent issue to support optimization of design and safety case abstraction. To tackle this challenge a research work package entitled “DONUT: Development and improvement of numerical methods and tools for modelling coupled processes” has been conducted within the EURAD join programming initiative. The purpose of this work package is to improve/develop methods or numerical tools in order to go a step further in development of (i) relevant, performant and cutting-edge numerical methods that can easily be implemented in existing or new tools, in order to carry out high-performance computing to facilitate the study of highly coupled processes in large systems, (ii) numerical scale transition schemes for coupled processes, (iii) innovative numerical methods to carry out uncertainty and sensitivity analyses. In this paper the work carried out within the DONUT work package is put in perspective regarding the existing concept and literature on the field. It does not pretend to be exhaustive but rather to put emphasis on particular issues tackled during the project.

Permalink: https://www.hzdr.de/publications/Publ-40923


Heat transfer enhancement for nucleate boiling via microlayer disruption on micro-pillar arrayed surfaces

Zhang, J.; Li, R.; Vadlamudi, S. R. G.; Pang, C.; Hampel, U.; Ding, W.

Abstract

Surface modifications have demonstrated significant potential in enhancing heat transfer in nucleate boiling, yet their impact on microlayer evaporation—a key heat transfer mechanism—remains less understood. In this work, we performed isolated bubble nucleate boiling experiments with micro-pillar arrayed surfaces to study the microlayer heat transfer. We initially analyzed the bubble dynamics, including growth dynamics and shape evolution throughout the entire bubble life cycle on these surfaces in detail. The results show that bubble dynamics differ considerably across different surfaces under the same surface superheat, primarily due to differences in microlayer evaporation. We then statistically quantify the bubble growth dynamics to evaluate the microlayer heat transfer performance. Importantly, we found that the experimental results align closely with the inference on the microlayer heat transfer derived from our previous simulation results of initial microlayer morphology on similar surfaces. This alignment allowed us to experimentally confirm the existence of two distinctive microlayer morphologies on micro-pillar arrayed surfaces, as observed in our previous simulations: the disturbed and the disrupted microlayer. We demonstrated that the microlayer morphology governs its heat transfer performance and, consequently, bubble dynamics during the entire bubble life cycle. Notably, our findings suggest the existence of a critical microlayer thickness, which can be achieved through surface modifications, to sustain a high evaporation rate throughout the bubble life cycle. To optimize surface design, we proposed a microlayer morphology concept that links the microlayer morphology with the corresponding heat transfer performance on micro-pillar arrayed surfaces.

Keywords: Nucleate boiling; Microlayer morphology; Micro-pillar arrayed surface; Heat transfer; Surface engineering

Permalink: https://www.hzdr.de/publications/Publ-40921


Data publication: Benchmarking a magnon-scattering reservoir with modal and temporal multiplexing

Heins, C.; Kim, J.-V.; Körber, L.; Faßbender, J.; Schultheiß, H.; Schultheiß, K.

Abstract

This data publication contains the data for the publication "Benchmarking a magnon-scattering reservoir with modal and temporal". The dataset is structured in folders corresponding to the different figures in the paper. The parent folder contains the full BLS spectrum and the input used to generate that spectrum. Folder Fig2 contains the experimental data measured with Brillouin-light-scattering microscopy integrated for the measured positions. Fig3 and Fig4 contain the extraction and evaluation. Each Folder contains additional information about their content.

Keywords: reservoir computing; spin wave; magnon; magnetic vortex; nonlinearity; Brillouin light scattering

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Permalink: https://www.hzdr.de/publications/Publ-40920


High-Performance Visible-to-SWIR Photodetector Based on the Layered WS2 Heterojunction with Light-Trapping Pyramidal Black Germanium

Bhattacharya, K.; Chaudhary, N.; Bisht, P.; Satpati, B.; Manna, S.; Singh, R.; Mehta, B. R.; Georgiev, Y.; Das, S.

Abstract

This study presents a layered transition metal dichalcogenide/black germanium (b-Ge) heterojunction photodetector that exhibits superior performance across a broad spectrum of wavelengths spanning from visible (vis) to shortwave infrared (SWIR). The photodetector includes a thin layer of b-Ge, which is created by wet etching of germanium (Ge) wafer to form submicrometer pyramidal structures. On top of this b-Ge layer, the WS2 thin film is deposited using pulsed laser deposition. In comparison to conventional germanium, b-Ge absorbs about 25% more light between 850 and 1750 nm wavelengths. The WS2/b-Ge photodetector has a peak photoresponsivity of 0.65 A/W, which is more than twice the photoresponsivity of the WS2/Ge photodetector at 1540 nm. Additionally, it shows better responsivity and response speed compared with other similar state-of-the-art photodetectors.
Such an improvement in the performance of the device is credited to the lighttrapping effect enabled by the germanium pyramids. Theoretical simulations employing the finite-difference time-domain technique help validate the concept. This novel photodetector holds promise for efficient detection of light across the vis to SWIR spectrum.

Keywords: layered TMD; germanium pyramids; black germanium; heterojunction photodetector; light trapping; FDTD

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  • Secondary publication expected from 31.08.2025

Permalink: https://www.hzdr.de/publications/Publ-40911


Flexible, printed and eco-sustainable magnetic field sensors

Zabila, Y.; Guo, L.; Sergio Oliveros Mata, E.; Xu, R.; Makarov, D.

Abstract

Magnetic field sensors are integral part of our household electronics, automation and IoT. Conventional magnetic field sensors are rigid components prepared on Si wafers. We realise biocompatible, biodegradable and self-healable magnetosensitive devices using printed and flexible electronics technologies. With these activities, we minimise electronic waste and bring magnetoelectronics to new application fields in medical implants, health monitoring and human-machine interfaces.

Composites consisting of magnetic fillers in polymers and elastomers enable new application scenarios in soft robotics [1,2] and reconfigurable actuation [3]. Furthermore, they gave birth to the novel technology of solution processable magnetic field sensors. We demonstrate that printed magnetoelectronics can be stretchable, skin-conformal, capable of detection of low magnetic fields and withstand extreme mechanical deformations [4,5]. We feature the potential of our skin-conformal sensors in augmented reality settings for remote and touchless control of virtual objects, scrolling electronic documents and zooming maps. We put forth technology to realise magnetic field sensors, which can be printed and self-heal upon mechanical damage [6]. This opens exciting perspectives for magnetoelectronics in smart wearables, interactive printed electronics. Moreover, this research motivates further explorations towards the realization of eco-sustainable magnetoelectronics. For the latter, we will discuss biocompatible and biodegradable magneto sensitive devices, which can help to minimise electronic waste and bring magnetoelectronics to new application fields in medical implants and health monitoring.

REFERENCES
[1] Y. Liu, G. Lin, M. Medina, M. G. Noguera, D. Makarov, and D. Jin, “Responsive magnetic nanocomposites for intelligent shape-morphing microrobots,” ACS Nano vol. 17, pp. 8899-8917, May 2023.
[2] M. Richter, J. Sikorski, P.Makushko, Y. Zabila, V. K. Venkiteswaran, D. Makarov, and S. Misra, “Locally addressable energy efficient actuation of magnetic soft actuator array systems,” Advanced Science vol. 10, pp. 2302077, Aug. 2023.
[3] M. Ha, G. S. Cañón Bermúdez, J. A.-C. Liu, E. S. Oliveros Mata, B. A. Evans, J. B. Tracy, and D. Makarov, "Reconfigurable magnetic origami actuators with on-board sensing for guided assembly," Adv. Mater. vol. 33, pp. 2008751, Jun. 2021.
[4] M. Ha, G. S. Cañón Bermúdez, T. Kosub, I. Mönch, Y. Zabila, E. S. Oliveros Mata, R. Illing, Y. Wang, J. Fassbender, and D. Makarov, “Reconfigurable magnetic origami actuators with on-board sensing for guided assembly,” Advanced Materials vol. 33, pp. 2005521, Mar 2021.
[5] E. S. Oliveros Mata, C. Voigt, G. S. Cañón Bermúdez, Y. Zabila, N. M. Valdez-Garduño, M. Fritsch, S. Mosch, M. Kusnezoff, J. Fassbender, M. Vinnichenko, and D. Makarov, "Dispenser printed bismuth-based magnetic field sensors with non-saturating large magnetoresistance for touchless interactive surfaces," Adv. Mater. Technol. vol. 7, pp. 2200227, Oct. 2022.
[6] R. Xu, G. S. Cañón Bermúdez, O. V. Pylypovskyi, O. M. Volkov, E. S. Oliveros Mata, Y. Zabila, R. Illing, P. Makushko, P. Milkin, L. Ionov, J. Fassbender, and D. Makarov, "Self-healable printed magnetic field sen-sors using alternating magnetic fields," Nature Communications vol. 13, pp. 6587, Nov. 2022.

  • Invited lecture (Conferences)
    RAEng workshop on Alternative device concepts for flexible electronics, 25.11.2024, Royal Academy of Engineering, London, United Kingdom

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Permalink: https://www.hzdr.de/publications/Publ-40910


Multifunctional smart skins for human machine interfaces and robotics

Zabila, Y.

Abstract

Mechanically soft electronics relies on functional elements, which are prepared on flexible and elastic membranes, allowing for bending, folding, or twisting. This technology enables applications in smart skins, smart textiles and soft robotics. Crucial to flexible interactive on-skin and wearable electronics are flexible magnetic field sensors [1], facilitating the monitoring of various types of motion. Typically, magnetic thin films are employed in flexible magnetoelectronics for detecting in-plane magnetic fields [2-4]. To enhance sensitivity to out-of-plane magnetic fields [5], Bi-based Hall effect sensors have demonstrated efficiency in smart wearables and electromobility applications [6].

Semi-metallic Bi thin films exhibit exceptionally high magnetoresistance (MR) and a robust Hall effect, even at room temperature, particularly when patterned to a small lateral size. Our research delves into the remarkable strain sensitivity of Bi thin films to create a multifunctional flexible device capable of simultaneously measuring strain and magnetic fields. We fabricate Bi thin films of different thickness on ultrathin polyimide foils. These sensors prove their mechanically stable, enduring severe mechanical bending with radii as small as 1 mm for 10,000 bending cycles. We introduce and validate a measurement sequence based on the spinning current approach, effectively decoupling signals measured by a single sensor element in transversal and longitudinal resistance channels. Furthermore, we have developed a method to analyze the measured transversal and longitudinal resistances, enabling the assessment of the out-of-plane component of the magnetic field (Hall effect)
and vector components of in-plane strain (piezoresistive effect). These sensors find application as a component of smart skin for soft robotics and human-machine interfaces. In this presentation, we will demonstrate the key aspects linking the fundamental properties of Bi thin films to their practical implementation in flexible sensor devices for simultaneous strain and magnetic field sensing.

References
[1] G.S. Cañón Bermúdez et al., Magnetosensitive E-Skins for Interactive Devices. Adv. Funct. Mater. 31, 2007788 (2021).
[2] R. Xu, Y. Zabila et al., Self-healable printed magnetic field sensors using alternating magnetic fields. Nature Communications 13, 6587 (2022).
[3] M. Ha, Y. Zabila et al., Printable and Stretchable Giant Magnetoresistive Sensors for Highly Compliant and Skin-conformal Electronics. Adv. Mater. 33, 2005521 (2021).
[4] E. S. Oliveros Mata, Y. Zabila et al., Dispenser printed bismuth-based magnetic field sensors with nonsaturating large magnetoresistance for touchless interactive surfaces. Adv. Mater. Technol. 7, 2200227 (2022).
[5] P. Makushko, Y. Zabila et al., Flexible Magnetoreceptor with Tunable Intrinsic Logic for On-Skin Skin Touchless Human-Machine Interfaces. Adv. Funct. Mater. 31, 2101089 (2021).
[6] M. Melzer, Y. Zabila et al., Wearable Magnetic Field Sensors for Flexible Electronics. Adv. Mater. 27, 1274 (2015).

  • Invited lecture (Conferences)
    iSIM 2024 - International Symposium on Integrated Magnetics, 04.-05.05.2024, Rio de Janeiro, Brazil

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Permalink: https://www.hzdr.de/publications/Publ-40909


Flexible, printed and eco-sustainable magnetic field sensors

Zabila, Y.; Guo, L.; Sergio Oliveros Mata, E.; Xu, R.; Makarov, D.

Abstract

Magnetic field sensors are integral part of our household electronics, automation and IoT. Conventional magnetic field sensors are rigid components prepared on Si wafers. We realise biocompatible, biodegradable and self-healable magnetosensitive devices using printed and flexible electronics technologies. With these activities, we minimise electronic waste and bring magnetoelectronics to new application fields in medical implants, health monitoring and human-machine interfaces.
Composites consisting of magnetic fillers in polymers and elastomers enable new application scenarios in soft robotics [1,2] and reconfigurable actuation [3]. Furthermore, they gave
birth to the novel technology of solution processable magnetic field sensors. We demonstrate that printed magnetoelectronics can be stretchable, skin-conformal, capable of detection of low magnetic fields and withstand extreme mechanical deformations [4,5]. We feature the potential of our skinconformal sensors in augmented reality settings for remote and touchless control of virtual objects, scrolling electronic documents and zooming maps. We put forth technology to realise magnetic field sensors, which can be printed and selfheal upon mechanical damage [6]. This opens exciting perspectives for magnetoelectronics in smart wearables, interactive printed electronics. Moreover, this research motivates further explorations towards the realization of ecosustainable magnetoelectronics. For the latter, we will discuss biocompatible and biodegradable magneto sensitive devices, which can help to minimise electronic waste and bring magnetoelectronics to new application fields in medical implants and health monitoring.

REFERENCES
[1] Y. Liu, G. Lin, M. Medina, M. G. Noguera, D. Makarov, and D. Jin,
“Responsive magnetic nanocomposites for intelligent shape-morphing
microrobots,” ACS Nano vol. 17, pp. 8899-8917, May 2023.
[2] M. Richter, J. Sikorski, P.Makushko, Y. Zabila, V. K. Venkiteswaran,
D. Makarov, and S. Misra, “Locally addressable energy efficient
actuation of magnetic soft actuator array systems,” Advanced Science vol.
10, pp. 2302077, Aug. 2023.
[3] M. Ha, G. S. Cañón Bermúdez, J. A.-C. Liu, E. S. Oliveros Mata, B. A.
Evans, J. B. Tracy, and D. Makarov, "Reconfigurable magnetic origami
actuators with on-board sensing for guided assembly," Adv. Mater. vol. 33,
pp. 2008751, Jun. 2021.
[4] M. Ha, G. S. Cañón Bermúdez, T. Kosub, I. Mönch, Y. Zabila, E. S.
Oliveros Mata, R. Illing, Y. Wang, J. Fassbender, and D. Makarov,
“Reconfigurable magnetic origami actuators with on-board sensing for
guided assembly,” Advanced Materials vol. 33, pp. 2005521, Mar 2021.
[5] E. S. Oliveros Mata, C. Voigt, G. S. Cañón Bermúdez, Y. Zabila, N. M.
Valdez-Garduño, M. Fritsch, S. Mosch, M. Kusnezoff, J. Fassbender, M.
Vinnichenko, and D. Makarov, "Dispenser printed bismuth-based
magnetic field sensors with non-saturating large magnetoresistance for
touchless interactive surfaces," Adv. Mater. Technol. vol. 7, pp. 2200227,
Oct. 2022.
[6] R. Xu, G. S. Cañón Bermúdez, O. V. Pylypovskyi, O. M. Volkov, E. S.
Oliveros Mata, Y. Zabila, R. Illing, P. Makushko, P. Milkin, L. Ionov,
J. Fassbender, and D. Makarov, "Self-healable printed magnetic field sensors using alternating magnetic fields," Nature Communications vol. 13,
pp. 6587, Nov. 2022.

Keywords: flexible magnetoelectronics; printed magnetoelectronics; biocompatible magnetic field sensors

  • Open Access Logo Invited lecture (Conferences)
    Intermag 2024, IEEE International Magnetics Conference, 05.-10.05.2024, Rio de Janeiro, Brazil

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Permalink: https://www.hzdr.de/publications/Publ-40908


A new pairwise encounter probability estimator for range-resident animals

Calabrese, J.; Martinez Garcia, R.; Colombo, E. H.; Simoes Silva, I. M.; Menezes, J.; Fleming, C.

Abstract

Direct encounters, which can occur when two animals come within a threshold distance of each another, underpin many ecological processes including predation, mating, contest competition, territory formation, and disease transmission. The probability of encounter is therefore of fundamental quantity, and has historically been quantified from animal tracking data via two classes of metrics that feature contrasting strengths and weaknesses. Trajectory-based methods estimate the frequency of simultaneous location observations between two individuals that are within a threshold distance, d. In contrast, distribution-based methods use home range overlap as a proxy for encounter potential. While trajectory-based metrics directly quantify the probability of encounter, they are sensitive to the sampling frequency and yield underestimates when data are sparse, often failing to detect any encounters. In contrast, home-range-based metrics have good statistical properties, including insensitivity to sampling frequency, but are not straightforwardly related to encounter probability. Here, we introduce a distribution-based estimator of the probability of encounter. Using mathematical arguments, simulated data, and empirical case studies, we show that, like trajectory-based methods, our metric directly and accurately estimates encounter probability, while also displaying the sampling insensitivity of methods based on home range overlap. Furthermore, our probability of encounter estimator features reliable confidence intervals, and is implemented in and fully integrated with the ctmm R package (v1.2+) for movement analysis.

Keywords: animal tracking data; continuous-time models; ctmm; encounter probability; species interactions

  • Lecture (Conference)
    BioMove Symposium 2024, 01.03.2024, Potsdam, Deutschland

Permalink: https://www.hzdr.de/publications/Publ-40907


A Novel, Range-Distribution-Based Estimator of Pairwise Encounter Probabilities

Calabrese, J.; Martinez Garcia, R.; Menezes, J.; Medici, P.; Morato, R.; Fleming, C.

Abstract

Direct encounters, which can occur when two animals come within a threshold distance of each another, underpin many ecological processes including predation, mating, contest competition, territory formation, and disease transmission. The probability of encounter is therefore of fundamental quantity, and has historically been quantified from animal tracking data via two classes of metrics that feature contrasting strengths and weaknesses. Trajectory-based methods estimate the frequency of simultaneous location observations between two individuals that are within a threshold distance, d. In contrast, distribution-based methods use home range overlap as a proxy for encounter potential. While trajectory-based metrics directly quantify the probability of encounter, they are sensitive to the sampling frequency and yield underestimates when data are sparse. In contrast, home-range-based metrics have good statistical properties, including insensitivity to sampling frequency, but are not straightforwardly related to encounter probability. Here, we introduce a distribution-based estimator of the probability of encounter. Using mathematical arguments, simulated data, and empirical case studies, we show that, like trajectory-based methods, our metric directly and accurately estimates encounter probability, while also displaying the sampling insensitivity of methods based on home range overlap. Furthermore, our probability of encounter estimator features reliable confidence intervals, and is implemented in and fully integrated with the ctmm R package (v1.2+) for movement analysis.

  • Invited lecture (Conferences)
    Brin Mathematics Research Center: Applied Stochastic Processes for Encounter Problems, 06.02.2024, College Park, USA

Permalink: https://www.hzdr.de/publications/Publ-40906


Data publication for "Feasibility of Na-Zn batteries for grid-scale energy storage: insights from in situ studies"

Sarma, M.; Shevchenko, N.; Weber, N.; Weier, T.

Abstract

This dataset contains unprocessed results from the X-ray radiography imaging of high temperature molten salt Na-Zn battery.

The folders are structured as follows:

- 01 to 03 correspond to radiography results,

- 04 corresponds to comparison of long-term cycling of two different batteries.

01 to 03 has subfolder structure as follows:

- 01 has the raw files in 16bit tiff format,

- 02 has unprocessed png files with fixed contrast and overlay of cycling data for each time step,

- 03 is an mp4 video of png files made with ffmpeg,

- 04 is the recorded cycling data.

The raw data has the Date and time as title.

There is 167 second offset between radiographs and electrochemical data (one has to add the offset time to join both data sets).

Cycling data has been exported as .txt from EC-Lab V11.61 with following variables:

*time/s* *Ewe/V* *I/mA* *(Q-Q0)/mA.h* *cycle number* *mode* *ox/red*

This project has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No 963599.

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Permalink: https://www.hzdr.de/publications/Publ-40905


Interfacing Single Layer Graphene with Ferromagnets for Terahertz Spintronics

Koyun Yücel, H. N.; Salikhov, R.; Winnerl, S.; Lindner, J.; Ünlü, C. G.; Helm, M.

Abstract

Efficient broadband electronic frequency multipliers and modulators for the terahertz (THz) frequency range require integration of a highly nonlinear material like graphene (Gr) in an electronic device. In ferromagnetic (FM) materials, on the other hand, spin waves or magnons in a FM layer can be excited using THz light. Combining these materials in a Gr/FM heterostructure allows one to generate and inject a spin-polarized current into Gr, which is one goal of Gr-based spintronics. However, a major limitation arises in the presence of disorder and impurities on Gr during fabrication of a prototypical spintronic device, namely during metal deposition [1]. It has been shown that the level of structural damage can be reduced after the sputtering process on Gr by changing of sputtering configuration [2]. We follow this approach by depositing 2 nm of Permalloy (Py) onto single-layer graphene (SLG) with a change of the distance, which was 20 cm between target and substrate, and using SLG which was produced by chemical vapor deposition. We utilize two configurations, the standard configuration with the SLG facing the target and a flipped configuration, in which the backside of the SLG faces the target. Raman spectoscopy was carried out on the fabricated Si/SiO2/Gr/Py composite samples. Figure 1 compares the Raman spectra of SLG deposited in the two configurations. The characteristic D, G and 2D major peaks of Gr can be observed at around 1336 cm−1, 1582 cm−1 and 2678 cm−1, respectively. The Lorentzian shape of the 2D peak as well as the I2D/IG ratio of the samples for both configurations indicates a monolayer. The peak at 1336 cm−1 corresponds to the D-band, which is attributed to the presence of undesirable impurities in the structure. Since the D peak comes into sight in the presence of structural defects and disorders, the appearance of the higher D peak indicates that the deposition of Py induces disorder in the structure, especially in the unflipped deposition configuration. The ID/IG ratio which is used to assess the quality of the Gr was calculated as 0.31 for the flipped configuration (lower than the unflipped configuration, was 1.41) therefore this ratio implies a lower number of defects in the Gr. We see that the weak intensity of D-peak in the flipped configuration provides higher quality Gr and it was observed that even after Py deposition, quality of Gr can be maintained using the flipped configuration.

Keywords: Single Layer Graphene; Spin-polarized current; Graphene/Ferromagnet heterostructure

  • Open Access Logo Poster
    The 25th International Conference on the Electronic Properties of Two-Dimensional Systems (EP2DS-25) and 21st International Conference on Modulated Semiconductor Structures (MSS-21), 09.-14.07.2023, Grenoble, France

Permalink: https://www.hzdr.de/publications/Publ-40903


Optimizing Subwavelength Metallic Gratings For Enhanced Spintronic Terahertz Frequency Conversion Efficiency

Koyun Yücel, H. N.; Salikhov, R.; Fowley, C.; Lindner, J.; Winnerl, S.; Erbe, A.; Helm, M.; Faßbender, J.; Kovalev, S.

Abstract

Terahertz (THz) spintronics, operating on picosecond timescales, involves the generation and control of non-equilibrium electron spin states within the THz frequency regime. Efficient generation and control of spin currents launched by THz radiation with subsequent ultrafast spin-to-charge conversion is the current challenge for the next-generation of high-speed communication and data processing units. Recent studies have shown that THz light can efficiently drive coherent spin currents in nanometer-thick ferromagnet (FM)/heavy-metal (HM) heterostructures, primarily due to demagnetization process of FM and the ultrafast spin Seebeck effect arising from a THz-induced temperature imbalance between electronic and magnonic systems and rapid electron-phonon relaxation. Owing to the fact that the electron-phonon relaxation time is comparable (or smaller) to the period of a THz wave, the induced spin current from each half cycle of the THz wave results in THz second harmonic generation (TSHG) and THz optical rectification. In this study, we explore the potential of utilizing subwavelength-sized gold periodic arrays with a grating period smaller than the THz wavelength to enhance local spin currents, thereby improving the efficiency of THz frequency conversion. By fabricating different gratings with varying widths of Au stripes and spacing between them, we aim to achieve efficient spintronic THz frequency conversion in the near-field regime. Our findings indicate that power efficiency increases as the gap size decreases, resulting in a nine-fold enhancement at a 2 μm gap size.

Keywords: Terahertz spintronics; ferromagnet (FM)/heavy-metal (HM) heterostructures; Spin Current; Terahertz second harmonic generation

Involved research facilities

  • Poster
    Optical Terahertz Science and Technology, 08.-12.04.2024, Marburg, Germany

Permalink: https://www.hzdr.de/publications/Publ-40902


Advancing the Efficiency of Spintronic Terahertz Frequency Conversion

Koyun Yücel, H. N.; Salikhov, R.; Fowley, C.; Lindner, J.; Winnerl, S.; Erbe, A.; Faßbender, J.; Helm, M.; Kovalev, S.

Abstract

Terahertz (THz) spintronics, operating on picosecond timescales, involves the generation and control of non equilibrium electron spin states within the THz frequency regime. Recent studies have shown that THz light can efficiently drive coherent spin currents in nanometer-thick ferromagnet (FM)/heavy-metal (HM) heterostructures, primarily due to demagnetization process of FM and the ultrafast spin Seebeck effect. Owing to the fact that the electronphonon relaxation time is comparable (or smaller) to the period of a THz wave, the induced spin current from each half cycle of the THz wave results in THz second harmonic generation (TSHG) and THz optical rectification. In this study, we explore the potential of utilizing subwavelength-sized gold periodic arrays with a grating period smaller than the THz wavelength to enhance local spin currents, thereby improving the efficiency of THz frequency conversion.

Keywords: Terahertz Second Harmonic Generation; Efficiency; Spin Current; Ferromagnet/Heavy Metal Heterostructure

Involved research facilities

  • Lecture (Conference)
    87. Annual Meeting of DPG and DPG-Frühjahrstagung (DPG Spring Meeting) of the Condensed Matter Section (SKM), 17.-22.03.2024, Berlin, Germany

Permalink: https://www.hzdr.de/publications/Publ-40900


Early collapse of vegetation cover induced by nonreciprocal interactions

Pinto Ramos, D. I.

Abstract

Understanding large-scale vegetation cover dynamics has required the development of several mathematical models to predict its future in a changing climate. In these models, it is the rule rather than the exception that simplifications are made for mathematical simplicity and tractability of the model outcomes. Homogeneity and isotropy are assumptions that have allowed the community to develop a robust theory for the future of vegetation, and how this future is related to the phenomenon of spatial pattern formation. Nevertheless, several authors have extended the models beyond these assumptions, finding unexpected phenomena, such as the survivance of vegetation beyond the tipping point or the prediction of spatial structures not present in previous theories. In this work, we explore the effect of nonreciprocal interactions, which are a form of non-isotropy, combined with the finite region of the landscape that supports patterns modeled by boundary conditions for the model. We find that enough nonreciprocity can overcome the resilience induced by spatial patterns, and anti-intuitively, a homogeneous cover can become more resilient against environmental changes. Nonreciprocity always reduces the system's resilience, but introduces an interplay between the nonreciprocity and the competition range of plants that control the tipping point nontrivially. Our findings highlight the relevance of often ignored ingredients in mathematical models of vegetation cover.

  • Invited lecture (Conferences)
    School on Biological Physics across Scales: Pattern Formation, 11.-22.11.2024, ICTP-SAIFR, São Paulo, Brazil

Permalink: https://www.hzdr.de/publications/Publ-40898


A Cu3BHT-Graphene van der Waals Heterostructure with Strong Interlayer Coupling for Highly Efficient Photoinduced Charge Separation

Wang, Z.; Fu, S.; Zhang, W.; Liang, B.; Liu, T.-J.; Hambsch, M.; Pöhls, J. F.; Wu, Y.; Zhang, J.; Lan, T.; Li, X.; Qi, H.; Polozij, M.; Mannsfeld, S. C. B.; Kaiser, U.; Bonn, M.; Thomas Weitz, R.; Heine, T.; Parkin, S. S. P.; Wang, H. I.; Dong, R.; Feng, X.

Abstract

Two-dimensional van der Waals heterostructures (2D vdWhs) are of significant interest due to their intriguing physical properties critically defined by the constituent monolayers and their interlayer coupling. Synthetic access to 2D vdWhs based on chemically tunable monolayer organic 2D materials remains challenging. Herein, the fabrication of a novel organic–inorganic bilayer vdWh by combining π-conjugated 2D coordination polymer (2DCP, i.e., Cu3BHT, BHT = benzenehexathiol) with graphene is reported. Monolayer Cu3BHT with detectable µm2-scale uniformity and atomic flatness is synthesized using on-water surface chemistry. A combination of diffraction and imaging techniques enables the determination of the crystal structure of monolayer Cu3BHT with atomic precision. Leveraging the strong interlayer coupling, Cu3BHT-graphene vdWh exhibits highly efficient photoinduced interlayer charge separation with a net electron transfer efficiency of up to 34% from Cu3BHT to graphene, superior to those of reported bilayer 2D vdWhs and molecular-graphene vdWhs. This study unveils the potential for developing novel 2DCP-based vdWhs with intriguing physical properties.

Keywords: connductive 2D coordination polymers; 2D van der Waals heterostructures; interlayer coupling; charge separation

Permalink: https://www.hzdr.de/publications/Publ-40897


Temperature Effects of Nuclear and Electronic Stopping Power on Si and C Radiation Damage in 3C-SiC

Kucal, E.; Józwik, P.; Mieszczynski, C.; Heller, R.; Akhmadaliev, S.; Dufour, C.; Czerski, K.

Abstract

Silicon carbide has been considered a material for use in the construction of advanced hightemperature
nuclear reactors. However, one of the most important design issues for future reactors is
the development of structural defects in SiC under a strong irradiation field at high temperatures. To
understand how high temperatures affect radiation damage, SiC single crystals were irradiated at
room temperature and after being heated to 800 °C with carbon and silicon ions of energies ranging
between 0.5 and 21 MeV. The number of displaced atoms and the disorder parameters have been
estimated by using the channeling Rutherford backscattering spectrometry. The experimentally
determined depth profiles of induced defects at room temperature agree very well with theoretical
calculations assuming its proportionality to the electronic and nuclear-stopping power values. On
the other hand, a significant reduction in the number of crystal defects was observed for irradiations
performed at high temperatures or for samples annealed after irradiation. Additionally, indications
of saturation of the crystal defect concentration were observed for higher fluences and the irradiation
of previously defected samples.

Keywords: radiation damage; stopping power; Rutherford backscattering; ion channeling

Involved research facilities

Related publications

Permalink: https://www.hzdr.de/publications/Publ-40896


The n_TOF facility at CERN

Tagliente, G.; Aberle, O.; Alcayne, V.; Amaducci, S.; Andrzejewski, J.; Babiano-Suarez, V.; Bacak, M.; Balibrea Correa, J.; Bernardes, A. P.; Berthoumieux, E.; Beyer, R.; Boromiza, M.; Bosnar, D.; Caamaño, M.; Calviño, F.; Calviani, M.; Cano-Ott, D.; Casanovas, A.; Castelluccio, D. M.; Cerutti, F.; Cescutti, G.; Chasapoglou, S.; Chiaveri, E.; Claps, G.; Colombetti, P.; Colonna, N.; Console Camprini, P.; Cortés, G.; Cortés-Giraldo, M. A.; Cosentino, L.; Cristallo, S.; Dellmann, S.; Diacono, D.; Di Castro, M.; Diakaki, M.; Dietz, M.; Domingo-Pardo, C.; Dressler, R.; Dupont, E.; Durán, I.; Eleme, Z.; Eslami, M.; Fargier, S.; Fernández-Domínguez, B.; Finocchiaro, P.; Furman, V.; Gandhi, A.; García-Infantes, F.; Gawlik-Ramięga, A.; Gervino, G.; Gilardoni, S.; González-Romero, E.; Goula, S.; Griesmayer, E.; Guerrero, C.; Gunsing, F.; Gustavino, C.; Heyse, J.; Hillman, W.; Jenkins, D. G.; Jericha, E.; Junghans, A.; Kadi, Y.; Kaperoni, K.; Kokkoris, M.; Koll, D.; Kopatch, Y.; Krtička, M.; Kyritsis, N.; Ladarescu, I.; Lederer-Woods, C.; Lerendegui-Marco, J.; Lerner, G.; Manna, A.; Martínez, T.; Masi, A.; Massimi, C.; Mastinu, P.; Mastromarco, M.; Maugeri, E. A.; Mazzone, A.; Mendoza, E.; Mengoni, A.; Michalopoulou, V.; Milazzo, P. M.; Mucciola, R.; Musacchio-Gonzalez, E.; Musumarra, A.; Negret, A.; Pérez de Rada, A.; Pérez-Maroto, P.; Patronis, N.; Pavón-Rodríguez, J. A.; Pellegriti, M. G.; Perkowski, J.; Petrone, C.; Piersanti, L.; Pirovano, E.; Plaza del Olmo, J.; Pomp, S.; Porras, I.; Praena, J.; Quesada, J. M.; Reifarth, R.; Rochman, D.; Romanets, Y.; Rooney, A.; Rubbia, C.; Sánchez-Caballero, A.; Sabaté-Gilarte, M.; Scarpa, D.; Schillebeeckx, P.; Schumann, D.; Smith, A. G.; Sosnin, N. V.; Spelta, M.; Stamati, M. E.; Tamburrino, A.; Tarifeño-Saldivia, A.; Tarrío, D.; Torres-Sánchez, P.; Tosi, S.; Tsiledakis, G.; Valenta, S.; Vaz, P.; Vecchio, G.; Vescovi, D.; Vlachoudis, V.; Vlastou, R.; Wallner, A.; Weiss, C.; Woods, P. J.; Wright, T.; Žugec, P.

Abstract

The neutron Time-of-Flight (TOF) research facility at CERN, n_TOF, has been a pioneering platform for neutron cross-section measurements since its inception in 2001. It boasts three distinct experimental areas, each tailored to address a specific range of neutron energies. This paper delves into the intricacies of the n_TOF facility, including its recent upgrade during the Long Shutdown 2 (LS2) at CERN. Additionally, it highlights the key characteristics of the detectors employed for capture and fission cross-section measurements, paving the way for future research endeavors.

Keywords: CERN n_ToF

Permalink: https://www.hzdr.de/publications/Publ-40895


Experimental setup of the 239Pu neutron capture and fission cross-section measurements at n_TOF, CERN

Sanchez-Caballero, A.; Alcayne, V.; Andrzejewski, J.; Cano-Ott, D.; Cardinaels, T.; Dries, P.; Gawlik-Ramiega, A.; González-Romero, E.; Heyse, J.; Leinders, G.; Martínez, T.; Mendoza, E.; Moens, A.; Pérez de Rada, A.; Perkowski, J.; Plompen, A.; Paradela, C.; Schillebeeckx, P.; Sibbens, G.; van Hecke, K.; Vanaken, K.; Vanleeuw, D.; Verguts, K.; Verwerft, M.; Wynants, R.; Aberle, O.; Altieri, S.; Amaducci, S.; Babiano-Suarez, V.; Bacak, M.; Balibrea Correa, J.; Beltrami, C.; Bennett, S.; Bernardes, A.-P.; Berthoumieux, E.; Beyer, R.; Boromiza, M.; Bosnar, D.; Caamaño, M.; Calviño, F.; Calviani, M.; Casanovas, A.; Castelluccio, D.; Cerutti, F.; Cescutti, G.; Chasapoglou, S.; Chiaveri, E.; Colombetti, P.; Colonna, N.; Console Camprini, P.; Cortés, G.; Cortés-Giraldo, M.; Cosentino, L.; Cristallo, S.; Dellmann, S.; Di Castro, M.; Di Maria, S.; Diakaki, M.; Dietz, M.; Domingo-Pardo, C.; Dressler, R.; Dupont, E.; Durán, I.; Eleme, Z.; Fargier, S.; Fernández, B.; Fernández-Domínguez, B.; Finocchiaro, P.; Fiore, S.; Furman, V.; García-Infantes, F.; Gervino, G.; Gilardoni, S.; Guerrero, C.; Gunsing, F.; Gustavino, C.; Hillman, W.; Jenkins, D.; Jericha, E.; Junghans, A.; Kadi, Y.; Kaperoni, K.; Kaur, G.; Kimura, A.; Knapová, I.; Kokkoris, M.; Kopatch, Y.; Krtička, M.; Kyritsis, N.; Ladarescu, I.; Lederer-Woods, C.; Lerendegui-Marco, J.; Lerner, G.; Manna, A.; Masi, A.; Massimi, C.; Mastinu, P.; Mastromarco, M.; Maugeri, E.-A.; Mazzone, A.; Mengoni, A.; Michalopoulou, V.; Milazzo, P.; Mucciola, R.; Murtas, F.; Musacchio-Gonzalez, E.; Musumarra, A.; Negret, A.; Pérez-Maroto, P.; Patronis, N.; Pavón-Rodríguez, J.-A.; Pellegriti, M.; Petrone, C.; Pirovano, E.; Plaza del Olmo, J.; Pomp, S.; Porras, I.; Praena, J.; Quesada, J.-M.; Reifarth, R.; Rochman, D.; Romanets, Y.; Rubbia, C.; Sabaté-Gilarte, M.; Schumann, D.; Sekhar, A.; Smith, G.; Sosnin, N.; Stamati, M.-E.; Sturniolo, A.; Tagliente, G.; Tarifeño-Saldivia, A.; Tarrío, D.; Torres-Sánchez, P.; Vagena, V.; Valenta, S.; Variale, V.; Vaz, P.; Vecchio, G.; Vescovi, D.; Vlachoudis, V.; Vlastou, R.; Wallner, A.; Woods, P.-J.; Wright, T.; Zarrella, R.; Žugec, P.

Abstract

The experimental setup of the new measurement of 239Pu fission and capture cross-section in the n_TOF time-of-flight facility at CERN is presented. The measurement aims to address the needs and demands of nuclear data users. The experiment incorporates an innovative fast Fission Fragment Detector and the n_TOF Total Absorption Calorimeter, enabling the implementation of the fission tagging technique. Preliminary results exhibit the robust performance of the detector systems, along with the high quality of the new 239Pu samples. These samples were exclusively produced for this measurement by the European Commission’s Joint Research Centre in Geel.

Keywords: CERN n_ToF; 239Pu; neutron induced fission; neutron capture

Permalink: https://www.hzdr.de/publications/Publ-40894


Description and outlook of the 50, 53Cr(n, γ) cross section measurement at n_TOF and HiSPANoS

Pérez-Maroto, P.; Guerrero, C.; Casanovas, A.; Fernández, B.; Aberle, O.; Alcayne, V.; Altieri, S.; Amaducci, S.; Andrzejewski, J.; Babiano-Suarez, V.; Bacak, M.; Balibrea Correa, J.; Beltrami, C.; Bennett, S.; Bernardes, A. P.; Berthoumieux, E.; Beyer, R.; Boromiza, M.; Bosnar, D.; Caamaño, M.; Calviño, F.; Calviani, M.; Cano-Ott, D.; Castelluccio, D. M.; Cerutti, F.; Cescutti, G.; Chasapoglou, S.; Chiaveri, E.; Colombetti, P.; Colonna, N.; Console Camprini, P.; Cortés, G.; Cortés-Giraldo, M. A.; Cosentino, L.; Cristallo, S.; Dellmann, S.; Di Castro, M.; Di Maria, S.; Diakaki, M.; Dietz, M.; Domingo-Pardo, C.; Dressler, R.; Dupont, E.; Durán, I.; Eleme, Z.; Fargier, S.; Fernández-Domínguez, B.; Finocchiaro, P.; Fiore, S.; Furman, V.; García-Infantes, F.; Gawlik-Ramięga, A.; Gervino, G.; Gilardoni, S.; González-Romero, E.; Gunsing, F.; Gustavino, C.; Heyse, J.; Hillman, W.; Jenkins, D. G.; Jericha, E.; Junghans, A.; Kadi, Y.; Kaperoni, K.; Kaur, G.; Kimura, A.; Knapová, I.; Kokkoris, M.; Kopatch, Y.; Krtička, M.; Kyritsis, N.; Ladarescu, I.; Lederer-Woods, C.; Lerendegui-Marco, J.; Lerner, G.; Manna, A.; Martínez, T.; Masi, A.; Massimi, C.; Mastinu, P.; Mastromarco, M.; Maugeri, E. A.; Mazzone, A.; Mendoza, E.; Mengoni, A.; Michalopoulou, V.; Milazzo, P. M.; Mucciola, R.; Murtas, F.; Musacchio-Gonzalez, E.; Musumarra, A.; Negret, A.; Pérez de Rada, A.; Patronis, N.; Pavón-Rodríguez, J. A.; Pellegriti, M. G.; Perkowski, J.; Petrone, C.; Pirovano, E.; Plaza del Olmo, J.; Pomp, S.; Porras, I.; Praena, J.; Quesada, J. M.; Reifarth, R.; Rochman, D.; Romanets, Y.; Rubbia, C.; Sánchez-Caballero, A.; Sabaté-Gilarte, M.; Schillebeeckx, P.; Schumann, D.; Sekhar, A.; Smith, A. G.; Sosnin, N. V.; Stamati, M. E.; Sturniolo, A.; Tagliente, G.; Tarifeño-Saldivia, A.; Tarrío, D.; Torres-Sánchez, P.; Vagena, E.; Valenta, S.; Variale, V.; Vaz, P.; Vecchio, G.; Vescovi, D.; Vlachoudis, V.; Vlastou, R.; Wallner, A.; Woods, P. J.; Wright, T.; Zarrella, R.; Žugec, P.

Abstract

Chromium is a very relevant element regarding criticality safety in nuclear reactors because of its presence in stainless steel, an important structural material. Currently, there are serious discrepancies between the different evaluations regarding the neutron capture cross sections of 50Cr and 53Cr, most probably related to the difficulty of reducing and then estimating the very large neutron scattering effects on the shape of the resonances. In this context, there is a recent entry in the Nuclear Energy Agency (NEA) High Priority Request List (HPRL) to measure these reactions between 1 and 100 keV with an accuracy of 8-10%. In response to this request, we have performed a time-of-flight experiment at CERN n_TOF (Switzerland) and a complementary activation experiment on 50Cr at 30 and 90 keV at CNA HiSPANoS (Spain). The experiments are presented herein, together with a discussion on the quality of the preliminary data and the results to be expected.

Keywords: CERN n_ToF; HiSPANoS; neutron capture

Permalink: https://www.hzdr.de/publications/Publ-40893


Combining Liposomal Photocatalysts with Whole-Cell Catalysts for One-pot Photobiocatalysis

Zhang, J.; Batista, V. F.; Hübner, R.; Vogel, S.; Wu, C.

Abstract

Cooperative photobiocatalytic processes have seen extensive potentials for the synthesis of both bulk and fine chemicals owing to their versatility, eco-friendliness, and cost-effectiveness. Nevertheless, developing a universal and effective synthetic strategy compatible with both catalytic systems remains challenging. In this study, we explored cationic liposomes as biocompatible photocatalyst encapsulation systems and combined them with bacteria overexpressing enzymes for two-step and three-step cascade reactions. Specifically, the water-soluble photocatalyst anthraquinone-2-sulfonate (AQS), which can oxidize benzyl alcohol, is encapsulated within the core of cationic liposomes composed of dioleoyl-3-trimethylammonium propane (DOTAP) and the helper lipid cholesterol. The positive charge on the liposome surface enabled electrostatic interactions with the negative charges on the membrane of Escherichia coli cells. Bacterial cells overexpressing various enzymes, such as Candida antarctica lipase B (CalB) and benzaldehyde lyase (BAL), and coated with liposomes enabled the production of added value compounds through cascade reactions with excellent production. These cascades involve CalB-catalyzed hydrolysis, BAL-catalyzed condensation, and AQS-driven photo-oxidation reactions. Therefore, the strategy offers more possibilities of combining photocatalysis with biocatalysis for recoverability, enhanced mass transfer, and enhanced compatibility in both industrial biotechnology and synthetic chemistry.

Involved research facilities

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Permalink: https://www.hzdr.de/publications/Publ-40892


Data publication: Noise-induced nonreciprocal topological dissipative solitons in directionally coupled chains and lattices

Pinto Ramos, D. I.; Alfaro-Bittner, K.; Rojas, R. G.; Clerc, M. G.

Abstract

Simulation data in .npy format (Python) and the corresponding scripts (.py files) to run and generate the plots in the article.

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Permalink: https://www.hzdr.de/publications/Publ-40891


Silicon Nanowire Transistors: Device Characteristics to Sensing Applications

Ghosh, S.; Echresh, A.; Kentsch, U.; Prucnal, S.; Vardhan, V.; Biswas, S.; Holmes, J.; Erbe, A.; Georgiev, Y.

Abstract

Field-effect transistors based on silicon nanowires have been extensively used for sensing applications since the compact nanoscale structures allow excellent regulation of electrostatic potential across the nanowire channel. Sensors based on Junctionless Nanowire Transistors (JNT) have shown excellent sensitivity in liquid phases but they have not yet been operated in the gas phase.
In this work, we report the fabrication and characterisation of silicon-based JNT devices and their initial tests as gas sensors. Silicon-on-insulator wafers are doped by ion implantation and flash lamp annealing. Device patterning is based on electron beam lithography, inductively-coupled reactive ion etching, metal deposition and lift-off.
JNT sensor tests exhibited characteristic shifts in the transfer curve and a systematic increase and decrease of p- and n-type current, respectively, under the influence of different gases like NO2 and NH3 confirming potential suitability as gas sensors for detecting atmospheric radicals.

Keywords: Junctionless Nanowire Transistors (JNT); Sensor; NO2 Sensor; Atmospheric radicals; Ambipolar

Involved research facilities

Related publications

  • Lecture (Conference)
    87. Annual Meeting of DPG and DPG-Frühjahrstagung (DPG Spring Meeting) of the Condensed Matter Section (SKM), 17.-22.03.2024, Berlin, Germany

Permalink: https://www.hzdr.de/publications/Publ-40889


Leveraging grain boundary effects for nanostructured electrode layers in symmetric solid oxide fuel cells

Baiutti, F.; Chiabrera, F.; Anzengruber, M.; Kreka, K.; Sirvent, J.; Yedra, L.; Buzi, F.; Liedke, M. O.; Cavallaro, A.; Carmona Zuazo, A.; Estradé, S.; Butterling, M.; Hirschmann, E.; Wagner, A.; Aguadero, A.; Peiró, F.; Tarancon, A.

Abstract

While grain boundary engineering is attracting great interest as a potential strategy to fabricate highly electrochemically active materials, open questions remain in relation to the fundamental mechanisms of local property enhancement as well as to the potential technological impact of such nanostructuring strategies. In this paper, we consider nanocrystalline films of lanthanum chromite and we demonstrate the ability to turn the material from a predominantly electronic conductor to an excellent mixed-ionic electronic conductor by grain boundary doping. We highlight 4 orders of magnitude increase of the oxygen diffusion coefficient at grain boundaries and relate such a remarkable enhancement to local chemical changes. We show that grain boundary effects can be effectively exploited for technological purposes by fabricating a proof-of-concept symmetric solid oxide cell based on lanthanum chromite film electrodes. The cell is operated under reversible gas feeding conditions, exhibiting electrode self-healing characteristics. Our results provide new insights on the fundamental aspects of fast grain boundary oxygen diffusion and validate grain boundary engineering as a technologically relevant strategy for the realization of solid oxide cells with enhanced performance.

Keywords: SOFC; lanthanum chromite; grain boundaries; thin-films

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Permalink: https://www.hzdr.de/publications/Publ-40888


n_TOF Detector Developments

Patronis, N.; Aberle, O.; Alcayne, V.; Alpar, G.; Al Halabi, M.; Amaducci, S.; Babiano, V.; Bacak, M.; Balibrea-Correa, J.; Bartolomé, J.; Bernardes, A.-P.; Gameiro, B. B.; Berthoumieux, E.; Beyer, R.; Birch, M.; Boromiza, M.; Bosnar, D.; Brusasco, B.; Caamaño, M.; Cahuzac, A.; Calviño, F.; Calviani, M.; Cano-Ott, D.; Casanovas, A.; Castelluccio, D.; Catlett, D.; Cerutti, F.; Cescutti, G.; Chiaveri, E.; Claps, G.; Colombetti, P.; Colonna, N.; Console Camprini, P.; Cortés, G.; Cortés-Giraldo, M.; Cosentino, L.; Cristallo, S.; D'Ottavi, A.; de la Fuente Rosales, G.; Dellmann, S.; Diakaki, M.; Di Castro, M.; Di Chicco, A.; Dietz, M.; Domingo-Pardo, C.; Dupont, E.; Durán, I.; Eleme, Z.; Eslami, M.; Fargier, S.; Fernández-Domínguez, B.; Finocchiaro, P.; Flanagan, W.; Furman, V.; Gandhi, A.; García-Infantes, F.; Gawlik-Ramięga, A.; Gervino, G.; Gilardoni, S.; González-Romero, E.; Goula, S.; Griesmayer, E.; Guerrero, C.; Gunsing, F.; Gustavino, C.; Heyse, J.; Hillman, W.; Jenkins, D.; Jericha, E.; Junghans, A.; Kadi, Y.; Kaperoni, K.; Kelly, I.; Kokkoris, M.; Kopatch, Y.; Krtička, M.; Kyritsis, N.; Lederer-Woods, C.; Lerendegui-Marco, J.; Manna, A.; Martínez, T.; Martínez-Cañada, M.; Masi, A.; Massimi, C.; Mastinu, P.; Mastromarco, M.; Maugeri, E.-A.; Mazzone, A.; Mendoza, E.; Mengoni, A.; Michalopoulou, V.; Milazzo, P.; Moldenhauer, J.; Mucciola, R.; Musacchio González, E.; Musumarra, A.; Negret, A.; Odusina, E.; Papanikolaou, D.; Pavón-Rodríguez, J.; Pellegriti, M.; Pérez-Maroto, P.; Pérez de Rada Fiol, A.; Perfetto, G.; Perkowski, J.; Petrone, C.; Pieretti, N.; Piersanti, L.; Pirovano, E.; Porras, I.; Praena, J.; Quesada, J.-M.; Reifarth, R.; Rochman, D.; Romanets, Y.; Rooney, A.; Rovira, G.; Rubbia, C.; Sánchez-Caballero, A.; Sahoo, S.; Scarpa, D.; Schillebeeckx, P.; Smith, G.; Sosnin, N.; Spelta, M.; Stamati, M.-E.; Stasiak, K.; Tagliente, G.; Tarifeño-Saldivia, A.; Tarrío, D.; Torres-Sánchez, P.; Tosi, S.; Tsiledakis, G.; Valenta, S.; Vaz, P.; Vecchio, G.; Vescovi, D.; Vlachoudis, V.; Vlastou, R.; Wallner, A.; Weiss, C.; Woods, P. J.; Wright, T.; Wu, R.; Žugec, P.

Abstract

In this report, the ongoing developments of the n_TOF detectors are presented. The document describes the capabilities related to new research avenues and perspectives in new physics research with the n_TOF collaboration. It specifically summarizes the long and ongoing efforts of different working groups in developing detectors, considering the specific characteristics of the n_TOF experimental areas, with the goal of fully leveraging the unique features of the n_TOF facility.

Keywords: detector development; neutron physics; nuclear astrophysics; neutron induced fission studies; neutron induced charged particle reactions; CERN n_TOF; Time Of Flight; nuclear physics; medical physics; nuclear physics applications

Involved research facilities

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  • Open Access Logo Contribution to external collection
    in: CERN-n_TOF-PUB-2024-001, Geneva, Switzerland: CERN, 2024

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Permalink: https://www.hzdr.de/publications/Publ-40887


Magnetocaloric effect in La1−zCez(Fe0.88−yMnySi0.12)13 with tunable, low transition temperature in high magnetic fields

Straßheim, M.; Salazar Mejia, C.; Bykov, E.; Niehoff, T.; Beyer, L.; Freudenberger, J.; Hübner, R.; Ganss, F.; Naumann, T.; Wosnitza, J.; Gottschall, T.

Abstract

Cryogenic magnetic refrigeration becomes more and more important nowadays, especially for the liquefaction of gases such as hydrogen. In this study, we have synthesized La1–zCez(Fe0.88–yMnySi0.12)13 samples and investigated their magnetic and magnetocaloric properties in order to assess their potential for cryogenic applications. By adjusting the Mn and Ce content and adding excess rare-earth elements, the first-order ferromagnetic transition was lowered from 200 to 40 K and the adiabatic temperature change of the samples was measured directly using pulsed magnetic fields. The sample with the lowest transition temperature still showed a significant adiabatic temperature change in magnetic fields up to 10 T, with an increasingly stronger first-order transition observed in samples with higher Ce substitution. In addition, we synthesized spherical powder with diameters between 20 and 120 μm using ultrasonic atomization while maintaining the magnetic transition, which is a promising starting material for future additive manufacturing of magnetocaloric materials.

Involved research facilities

  • High Magnetic Field Laboratory (HLD)

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  • Secondary publication expected from 29.01.2026

Permalink: https://www.hzdr.de/publications/Publ-40886


Challenges and Future Directions of ART

Richter, C.; Jäckel, O.; Weykamp, F.; Dankulchai, P.

Abstract

Panel discussion

Involved research facilities

  • OncoRay
  • Lecture (others)
    PSCM School in Adaptive Radiation Therapy 2024, 12.-14.12.2024, Bangkok, Thailand

Permalink: https://www.hzdr.de/publications/Publ-40885


ART with particle therapy

Richter, C.

Abstract

ART with particle therapy

Involved research facilities

  • OncoRay
  • Invited lecture (Conferences)
    PSCM School in Adaptive Radiation Therapy 2024, 12.-14.12.2024, Bangkok, Thailand

Permalink: https://www.hzdr.de/publications/Publ-40884


Low-energy spin excitations in field-induced phases of the spin-ladder antiferromagnet BiCu2PO6

Pilch, P.; Amelin, K.; Schmiedinghoff, G.; Reinold, A.; Zhu, C.; Povarov, K.; Zvyagin, S.; Engelkamp, H.; Lan, Y.-P.; Shu, G.-J.; Chou, F. C.; Nagel, U.; Room, T.; Uhrig, G. S.; Fauseweh, B.; Wang, Z.

Abstract

We report on terahertz spectroscopic measurements of quantum spin dynamics on single crystals of a spin-1/2 frustrated spin-ladder antiferromagnet BiCu2PO6 as a function of temperature, polarization, and applied external magnetic fields. Spin triplon excitations are observed at zero field and split in applied magnetic fields. For magnetic fields applied along the crystallographic a axis, a quantum phase transition at Bc1 = 21.4 T is featured by a low-energy excitation mode emerging above Bc1, which indicates a gap reopening. For fields along the b axis and the c axis, different field dependencies are observed for the spin triplon excitations, whereas no low-lying modes could be resolved at field-induced phase transitions. We perform a theoretical analysis of the magnetic field dependence of the spin triplon modes by using continuous unitary transformations to determine an effective low-energy Hamiltonian. Through an exhaustive parameter search we find numerically optimized parameters to very well describe the experimentally observed modes, which corroborate the importance of significant magnetic anisotropy in the system.

Involved research facilities

  • High Magnetic Field Laboratory (HLD)

Permalink: https://www.hzdr.de/publications/Publ-40883


High precision image-guided proton therapy in 10 years

Richter, C.

Abstract

High precision image-guided proton therapy in 10 years

Involved research facilities

  • OncoRay
  • Invited lecture (Conferences)
    Advanced Imgaing in Radiotherapy, 29.-31.01.2024, Brussels, Belgium

Permalink: https://www.hzdr.de/publications/Publ-40882


Data publication: Exchange-Biased Multiring Planar Hall Magnetoresistive Sensors With Nanotesla Resolution in Nonshielded Environments

Schmidtpeter, J.; Das, P. T.; Zabila, Y.; Schubert, C.; Gundrum, T.; Wondrak, T.; Makarov, D.

Abstract

This entry includes the data presented in the publication "Exchange-Biased Multiring Planar Hall Magnetoresistive Sensors With Nanotesla Resolution in Nonshielded Environments"

Keywords: Magnetic Sensors; Planar Hall Effect; Noise Spectral Density

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Permalink: https://www.hzdr.de/publications/Publ-40881


Status and Application Perspectives of Laser Plasma Accelerators - the role of beam transport

Schramm, U.

Abstract

HED Invited Conference Talk / Introduction to plasma accelerators

Keywords: Plasma accelerators

Involved research facilities

Related publications

  • Invited lecture (Conferences)
    45th International Workshop on High-Energy-Density Physics with Intense Ion and Laser Beams, 27.-30.01.2025, Hirschegg, Österreich

Permalink: https://www.hzdr.de/publications/Publ-40877


Advancement of High Intensity Laser Driven Particle Accelerators to Application Readiness

Schramm, U.

Abstract

Eingeladener Vortrag zur Laser Ionenbeschleunigung und Anwendungen

Keywords: Laser proton acceleration; Plasma accelerator

Involved research facilities

  • Invited lecture (Conferences)
    44th International Workshop on High-Energy-Density Physics with Intense Ion and Laser Beams, 29.01.-01.02.2024, Hirschegg, Österreich
  • Invited lecture (Conferences)
    OPTICA High Brightness Sources and Ligth-Driven Interactions Congress High Intensity Lasers and High Field Phenomena, 12.-14.03.2024, Wien, Österreich
  • Invited lecture (Conferences)
    ICUIL Preisträgervortrag, 09.-13.09.2024, Cozumel, Mexico
  • Invited lecture (Conferences)
    ASILS 13, 16.-18.12.2024, Labh Garh Palace, Udaipur, Rajasthan, Indien

Permalink: https://www.hzdr.de/publications/Publ-40875


Data publication: How dual wetting electrode surfaces improve electrocatalytic hydrogen evolution

Rox, H.; Ränke, F.; Zschach, L. G.; Yang, X.; Mutschke, G.; Eckert, K.; Lasagni, A. F.; Baumann, R.

Abstract

Tuning the electrode surfaces for better bubble management is a promising approach to increase the efficiency of alkaline water electrolysis. Therefore, Direct Laser Writing was used to structure Nickel electrodes with a dual wetting surface. The applied pillar-like structure combines superhydrophilic behavior and strong spreading of the liquid across the electrode with hydrophobic bubble nucleation sites. In addition, the electrochemically active surface area is increased by a factor of 9. As a result, the overpotential has been significantly reduced, while the size of the detached bubble has increased. The present data set compares three different electrodes, a non-structured reference electrode and two laser structured electrodes with different depths of the structure, at applied current densities of j = -20, -50 and -100 mA/cm² in terms of electrode potential, detached bubble size and number of nucleation sites. As electrolyte 1 M KOH was used. All experiments were carried out under ambient conditions (T = 293 K,p = 1 bar).

Description of Data.zip:

An overview of all performed experiments is given in the file Summary.csv. The data is analyzed as described in the corresponding journal publication How dual wetting electrode surfaces improve electrocatalytic hydrogen evolution. Each data set is stored in a .hdf5-file, with the relevant metadata incorporated into the attributes assigned to the groups/datasets within the .hdf5-file. The data files are structured in groups as follows:

  • Electrochemical Measurement Data
    • Galvanostatic Measurement Data
    • CV double-layer capacitance
    • LSV onset potential
  • Results
    • Detected Bubbles Sideview
  • Sideview Raw Images (only for SH2_LS_Pil_01.hdf5)

With the exception of a single comprehensive data set comprising unprocessed images (SH2_LS_Pil_01.hdf5), the remaining raw images from all performed measurements can be made available upon request.

Keywords: Alkaline water electrolysis; Hydrogen evolution reaction; Bubble dynamics; Direct laser writing

Involved research facilities

  • Data Center

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Permalink: https://www.hzdr.de/publications/Publ-40874


Integration of imaging in clinical protocols of particle therapy

Trnkova, P.; Bolsi, A.; Knopf, A.; Hoffmann, A. L.

Abstract

An examination of the current landscape of image guidance in particle therapy, as utilized across numerous European particle therapy centres, will be provided herein. This analysis will encompass considerations pertaining to the anatomical location of tumours, the diverse clinical experiences, and the specific clinical demands encountered by various particle therapy centres.

  • Book chapter
    in: Imaging in Particle Therapy Current practice and future trends, London: IOP Publishing Ltd, 2024, 13-1-13-16
    DOI: 10.1088/978-0-7503-5117-1ch13

Permalink: https://www.hzdr.de/publications/Publ-40872


Exploring a nitric oxide-releasing celecoxib derivative as a potential modulator of bone healing: insights from ex vivo and in vivo imaging experiments

Neuber, C.; Niedenzu, L.; Schulze, S.; Laube, M.; Hofheinz, F.; Rammelt, S.; Pietzsch, J.

Abstract

The inducible enzyme cyclooxygenase-2 (COX-2) and the subsequent synthesis of eicosanoids initiated by this enzyme are important molecular players in bone healing. In this pilot study, the suitability of a novel selective COX-2 in-hibitor bearing a nitric oxide (NO) releasing moiety was investigated as a modulator of healing a critical size bone defect in rats. A 5-mm femoral defect was randomly filled with no material (negative control, NC), a mixture of col-lagen and autologous bone fragments (positive control, PC), or poly-co-caprolactone (PCL)-scaffolds coated with two types of artificial extra-cellular matrix (aECM; collagen/chondroitin sulfate (Col/CS) or colla-gen/polysulfated hyaluronic acid (Col/sHA3)). Bone healing was monitored by a dual-tracer ([18F]FDG/[18F]fluoride) approach using PET/CT imaging in vivo. In addition, ex vivo µCT imaging as well as histological and immunohisto-chemical studies were performed 16 weeks post-surgery. A significant higher uptake of [18F]FDG, a surrogate marker for inflammatory infiltrate, but not of [18F]fluorid, representing bone mineralization, was observed in the implanted PCL-scaffolds coated with either Col/CS or Col/sHA3. Molecular targeting of COX 2 with NO-coxib had no significant effect on tracer uptake in any of the groups. Histological and immunohistochemical staining showed no evidence of a positive or negative influence of NO-coxib treatment on bone healing.

Permalink: https://www.hzdr.de/publications/Publ-40871


Explorando os efeitos magnetocalóricos em materiais com transições de primeira ordem: um foco em altos campos magnéticos e baixas temperaturas

Salazar Mejia, C.

Abstract

es hat keine aussagefähiges Abstract vorgelegen

Involved research facilities

  • High Magnetic Field Laboratory (HLD)
  • Invited lecture (Conferences) (Online presentation)
    Workshop on i-Caloric Effects 2024, 25.-27.03.2024, Rio de Janeiro, Brasilien

Permalink: https://www.hzdr.de/publications/Publ-40870


Wissenschaftliche Metadaten und ihre Potenziale freilegen: Maßgeschneiderte Metadaten-Schulung für den Forschungsbereich Matter

Özkan, Ö.; Schaller, T.; Haghiri, H.; Günther, G.; Kubin, M.; Mannix, O.

Abstract

Um Forschende in den Grundkenntnissen der Metadatenkuration zu schulen, hat HMC den
Trainingskurs “Fundamentals of Scientific Metadata” entwickelt. (Gerlich et al. 2023)
HMC Hub Matter hat diesen Trainingskurs kürzlich für Communities aus dem Forschungsbereich
Materie angepasst, die von Teilchen-, Ionenstrahl- und Beschleunigerphysik bis hin zu Photonen- und
Neutronenforschung an Großgeräten reicht.

Keywords: Metadata Training; Fundamentals Training; HMC

  • Poster
    5. SaxFDM Tagung, 17.09.2024, Freiberg, Deutschland

Permalink: https://www.hzdr.de/publications/Publ-40869


Advancing Al-doped ZnO thin films structural, optical and electrical properties of low temperature PET substrates via flash lamp annealing

Lee, J.; Jo, C.-H.; Lee, G.; Bae, M.-S.; Prucnal, S.; Zhou, S.; Zubair Khan, M.; Gohar, O.; Saleem, M.; Koh, J.-H.

Abstract

In this study, aluminum-doped zinc oxide (AZO) thin films were deposited onto a low-temperature polyethylene terephthalate (PET) substrate using DC magnetron sputtering. Deposition parameters included power range of 100−300 W, a working pressure of 15 mTorr, and a substrate temperature of 50 °C. Post-deposition, flash lamp annealing (FLA) was employed as a rapid thermal processing method with a pulse duration of 1.7 ms and energy density of 7 J·cm−2, aimed at enhancing the film's quality while preserving the temperature-sensitive PET substrate. FLA offers advantages over conventional annealing,
including shorter processing times and improved material properties. The structural, optical, and electrical characteristics of the AZO films were assessed using X-ray diffraction, field emission scanning electron microscopy coupled with energy-dispersive X-ray spectroscopy, ultraviolet−visible spectroscopy, and Hall effect measurements. The results demonstrated that properties of AZO films varied with deposition and annealing conditions. Films deposited at 200 W and subjected to FLA exhibited superior crystallinity, with average visible light transmittance exceeding 80% and resistivity as low as 0.38 Ω·cm representing 95% improvement in transmittance. Electrical analysis revealed that carrier concentration, mobility, and resistivity were influenced by both sputtering and annealing parameters. These findings underscore the effectiveness of FLA in optimizing AZO thin film properties, highlighting potential in optoelectronics applications.

Keywords: Flash Lamp Annealing; AZO; sputtering; flexible electronics; doping

Involved research facilities

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  • Secondary publication expected from 15.09.2025

Permalink: https://www.hzdr.de/publications/Publ-40868


Defect migration and phase transformations in two-dimensional iron chloride inside bilayer graphene

Liu, Q.; Sun, H.; Lin, Y.-C.; Ghorbani Asl, M.; Kretschmer, S.; Solís-Fernández, P.; Siao, M.-D.; Chiu, P.-W.; Ago, H.; Krasheninnikov, A.; Suenaga, K.

Abstract

The intercalation of metal chlorides, and particularly iron chlorides, into graphitic carbon structures has recently received lots of attention, as it can not only protect this two-dimensional (2D) magnetic system from the effects of the environment, but also substantially alter the magnetic, electronic, and optical properties of both intercalant and host material. At the same time, the intercalation can result in the formation of structural defects, or defects can appear under external stimuli, which can affect materials performance. These aspects have received so far little attention in the dedicated experiments. In this study, we investigate the behavior of atomic-scale defects in iron chlorides intercalated into bilayer graphene (BLG) by using scanning transmission electron microscopy (STEM) and first-principles calculations. We observe transformations between the FeCl2 and FeCl3 phases and elucidate the role of defects in the transformations. Specifically, three types of defects are identified: Fe vacancies in FeCl2 domains, Fe adatoms and interstitials in FeCl3 domains, each exhibiting distinct dynamic behaviors. Our findings not only advance the understanding of intercalation chemistry of 2D materials, but also highlight the profound impact of atomic-scale defects on their properties and potential technological applications.

Keywords: intercalation; STEM; iron chloride; phase transformation; bilayer graphene

Involved research facilities

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  • Secondary publication expected from 24.01.2026

Permalink: https://www.hzdr.de/publications/Publ-40867


The VECTOR project - Overview and current status

Pereira, T.; Stockey, C.

Abstract

The presentation prepared for the PDAC 2024, is a short summary about the VECTOR project and its current status.

Keywords: VECTOR; Exploration; Shared Value; Data Science; Geoscience; Social Science

  • Open Access Logo Invited lecture (Conferences)
    PDAC 2024, 03.-6.3.2024, Toronto, Canada

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Permalink: https://www.hzdr.de/publications/Publ-40866


On the characterization of battery materials by means of iGC

Sygusch, J.; Rudolph, M.

Abstract

Characterization of Lithium ion battery components using inverse gas chromatography

  • Invited lecture (Conferences)
    Sorption Symposium Europe 2024 ​, 18.-19.09.2024, Wien, Österreich

Permalink: https://www.hzdr.de/publications/Publ-40865


Gorno and Piani Resinelli: genesis and correlations of two Alpine-type Pb-Zn districts

Summino, L.; Giorno, M. A.; Barale, L.; Bertok, C.; Frenzel, M.; Gasparrini, M.; Martire, L.

Abstract

The strata-bound, carbonate-hosted Pb-Zn-Ag (+ fluorite + baryte) districts of Gorno and Piani Resinelli belong to the Alpine metallogenic province located between Italy, Austria and Slovenia. The orebodies are hosted in the lower Carnian stratigraphic succession of the Lombardian Basin (Southalpine Domain, N Italy), mainly composed of peritidal limestones. The aim of this study is to constrain the ore-forming conditions using petrography, geochemistry, fluid inclusion microthermometry, and radiometric datings on both ore minerals
and associated diagenetic products.

Petrographic studies reveal that the mineralization was preceded by dolomitization, silicification, and brecciation events. Thermometric data from primary fluid inclusions in dolomite, sphalerite, and fluorite indicate the involvement of moderately hot (T between 70 and 150 °C) and high-salinity fluids (up to ~20 wt % eq NaCl) during ore precipitation. Radiometric dating performed on associated diagenetic minerals which pre- and postdate the sulfide mineralization reveals that the precipitation of the ore minerals occurred during the LateTriassic. Moreover, in situ analyses (EPMA, LA-ICP-MS) of trace elements on sphalerite will be presented here, including their implications for ore-forming conditions.

Several similarities between Gorno and Piani Resinelli in terms of diagenetic evolution of the host rock, temperature and composition of the fluids, and timing of the ore precipitation highlight the possibility that both districts could be related to a unique, widespread Late Triassic hydrothermal system, in which metal-rich fluids flowed upward through faults and associated fractures. This circulation in the Upper Triassic stratigraphic succession caused major modifications in the host rocks such as multiphase dolomitization, silicification,
dissolution, and brecciation, as well as the precipitation of ore minerals in a shallow burial setting.

  • Lecture (Conference)
    SGI - SIMP 2024 - Geology for a sustainable management of our Planet, 03.-05.09.2024, Bari, Italy

Permalink: https://www.hzdr.de/publications/Publ-40864


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