Publications Repository - Helmholtz-Zentrum Dresden-Rossendorf

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37208 Publications

Master Curve Testing of RPV Steels using Mini-C(T) Specimens – Irradiation Effects and Censoring Statistics

Das, A.; Chekhonin, P.; Houska, M.; Obermeier, F.; Altstadt, E.

Includes master curve data for the materials used in this work as well as the SEM images of the fracture surfaces.

Keywords: Fracture mechanics testing; sub-sized specimen; transition temperature; reactor pressure vessel steels; Master Curve; neutron-irradiation

  • Reseach data in the HZDR data repository RODARE
    Publication date: 2022-05-19
    DOI: 10.14278/rodare.1634
    License: CC-BY-4.0

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Permalink: https://www.hzdr.de/publications/Publ-34701
Publ.-Id: 34701


Extrinsic localized excitons in patterned 2D semiconductors

Yagodkin, D.; Greben, K.; Eljarrat Ascunce, A.; Kovalchuk, S.; Ghorbani Asl, M.; Jain, M.; Kretschmer, S.; Severin, N.; Rabe, J. P.; Krasheninnikov, A.; Koch, C. T.; Bolotin, K. I.

We demonstrate a new localized excitonic state in patterned monolayer 2D semiconductors. The signature of an exciton associated with that state is observed in the photoluminescence spectrum after electron beam exposure of several 2D semiconductors. The localized state, which is distinguished by non-linear power dependence, survives up to room temperature and is patternable down to 20 nm resolution. We probe the response of the new exciton to the changes of electron beam energy, nanomechanical cleaning, and encapsulation via multiple microscopic, spectroscopic, and computational techniques. All these approaches suggest that the state does not originate from irradiation-induced structural defects or spatially non-uniform strain, as commonly assumed. Instead, we show that it is extrinsic, likely a charge transfer exciton associated with the organic substance deposited onto the 2D semiconductor. By demonstrating that structural defects are not required for the formation of localized excitons. Our work opens new possibilities for further understanding of localized excitons as well as their use in the applications that are sensitive to the presence of defects, e.g. chemical sensing and quantum technologies.

Keywords: Two-dimensional materials; Excitons; MoS2; Electron beam; Defects; Patterning

Permalink: https://www.hzdr.de/publications/Publ-34695
Publ.-Id: 34695


Data publication: Influence of surface cleaning on quantum efficiency, lifetime and surface morphology of p-GaN:Cs photocathodes

Schaber, J.; Xiang, R.; Teichert, J.; Arnold, A.; Murcek, P.; Zwartek, P.; Ryzhov, A.; Ma, S.; Gatzmaga, S.; Michel, P.; Gaponik, N.

Origin-files zur Darstellung von thermischen Reinigung, Aktivierung und Quanteneffizienz-Überwachung von GaN Fotokathoden SEM Bilder als .tif Dateien EDX Spektren als Exel-files zur Darstellung von EDX Analysen AFM Orginal Bilder die mit dem Programm Gwiddion geöffnet werden können

Keywords: p-GaN; UV-photocathode; quantum efficiency; surface cleaning; surface morphology

  • Software in the HZDR data repository RODARE
    Publication date: 2022-05-17
    DOI: 10.14278/rodare.1625
    License: CC-BY-4.0

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Permalink: https://www.hzdr.de/publications/Publ-34690
Publ.-Id: 34690


Investigation of Tumor Cells and Receptor-Ligand Simulation Models for the Development of PET Imaging Probes Targeting PSMA and GRPR and a Possible Crosstalk between the Two Receptors

Liolios, C.; Patsis, C.; Lambrinidis, G.; Tzortzini, E.; Roscher, M.; Bauder-Wüst, U.; Kolocouris, A.; Kopka, K.

Prostate-specific membrane antigen (PSMA) and gastrin-releasing peptide receptor (GRPR) have both been used in nuclear medicine as targets for molecular imaging and therapy of prostate (PCa) and breast cancer (BCa). Three bioconjugate probes, the PSMA specific: [68Ga]Ga-1, ((HBED-CC)-Ahx-Lys-NH-CO-NH Glu or PSMA-11), the GRPR specific: [68Ga]Ga-2, ((HBED-CC)-4-amino-1-carboxymethyl piperidine-[D-Phe6, Sta13]BN(6-14), a bombesin (BN) analogue), and 3 (the BN analogue: 4-amino-1-carboxymethyl piperidine-[(R)-Phe6, Sta13]BN(6-14) connected with the fluorescent dye, BDP-FL), were synthesized and tested in vitro with PCa and BCa cell lines, more specifically, with PCa cells, PC-3 and LNCaP, with BCa cells, T47D, MDA-MB-231, and with the in-house created PSMA-overexpressing PC-3(PSMA), T47D(PSMA), and MDA-MB-231(PSMA). In addition, biomolecular simulations were conducted on the association of 1 and 2 with PSMA and GRPR. The PSMA overexpression resulted in an increase of cell-bound radioligand [68Ga]Ga-1 (PSMA) for PCa and BCa cells and also of [68Ga]Ga-2 (GRPR), especially in those cell lines already expressing GRPR. The results were confirmed by fluorescence-activated cell sorting with a PE-labeled PSMA-specific antibody and the fluorescence tracer 3. The docking calculations and molecular dynamics simulations showed how 1 enters the PSMA funnel region and how pharmacophore Glu-urea-Lys interacts with the arginine patch, the S1', and S1 subpockets by forming hydrogen and van der Waals bonds. The chelating moiety of 1, that is, HBED-CC, forms additional stabilizing hydrogen bonding and van der Waals interactions in the arene-binding site. Ligand 2 is diving into the GRPR transmembrane (TM) helical cavity, thereby forming hydrogen bonds through its amidated end, water-mediated hydrogen bonds, and π-π interactions. Our results provide valuable information regarding the molecular mechanisms involved in the interactions of 1 and 2 with PSMA and GRPR, which might be useful for the diagnostic imaging and therapy of PCa and BCa.

Keywords: GRPR; LNCaP; MD simulations; MD-MB231; PC-3; PET imaging; PSMA; T47D; breast cancer; prostate cancer

Permalink: https://www.hzdr.de/publications/Publ-34687
Publ.-Id: 34687


Current- and field- induced magnetization dynamics and magnetic configurations in cylindrical nanowires

Fernandez Roldan, J. A.

In the last years the take-off of three-dimensional nanomagnetism has brought into scene diverse novel non-trivial magnetic textures that could be of interest for spintronic and nanoelectronics applications [1,2]. Particularly, cylindrical nanowires are fascinating building blocks of nanoarchitectures due to its surface curvature that promotes domain walls that are likely to reach the high velocities required for fast recording technologies like the Bloch Point (BP) domain wall [3-6], and non-trivial magnetic configurations like Skyrmion tubes [7-9]. The challenge in several technologies based on these objects is to achieve the fast controlled propagation of domain walls and tailoring magnetic domain structure. In this talk I will review recent developments in spin-polarized current- and field- magnetization processes in cylindrical nanowires [4,5], and present three-dimensional magnetic configurations that are appealing for the development of advanced technologies.

[1] A. Fernandez-Pacheco et al., Three-dimensional nanomagnetism. Nat. Commun. 8, 15756 (2017)
[2] B. Dieny et al., Opportunities and challenges for spintronics in the microelectronics industry. Nat. Electron. 3, 446–459 (2020).
[3] S. Da Col et al., Observation of Bloch-point domain walls in cylindrical magnetic nanowires, Phys. Rev. B, 89, 180405 (2014).
[4] X.-P. Ma et al., Cherenkov-type three-dimensional breakdown behavior of the Bloch-point domain wall motion in the cylindrical nanowire, Appl. Phys. Lett. 117, 062402 (2020).
[4] J.A. Fernandez-Roldan et al., Electric current and field control of vortex structures in cylindrical magnetic nanowires, Phys. Rev. B 102, 024421 (2020).
[5] M. Schöbitz et al., Fast Domain Wall Motion Governed by Topology and Oersted Fields in Cylindrical Magnetic Nanowires. Phys. Rev. Lett. 123, 217201 (2019).
[6] J. A. Fernandez-Roldan, C. Bran, R. P. del Real, M. Vazquez and O. Chubykalo-Fesenko. Bloch Point propagation in cylindrical nanowires under spin-polarized currents. (Submitted) (2021)
[7] J. A. Fernandez-Roldan et al, Magnetization pinning in modulated nanowires: from topological protection to the “corkscrew” mechanism, Nanoscale 10, 5923 (2018)
[8] J. Garcia et al, Narrow Segment Driven Multistep Magnetization Reversal Process in Sharp Diameter Modulated Fe67Co33 Nanowires, Nanomaterials 2021, 11(11), 3077 (2021).
[9] E. Berganza et al., Evidence of Skyrmion-Tube Mediated Magnetization Reversal in Modulated Nanowires. Materials 14, 5671 (2021).

Keywords: Cylindrical Magnetic Nanowire; magnetic domain wall; magnetic domain; spin-polarized current; Oersted field; skyrmion tube; three-dimensional nanomagnetism

  • Open Access Logo Invited lecture (Conferences) (Online presentation)
    Magnetic Resonance Laboratory Seminars (Argentina), 17.05.2022, Bariloche, Rio Negro, Argentina

Permalink: https://www.hzdr.de/publications/Publ-34672
Publ.-Id: 34672


Magnetoelectric antiferromagnet Cr2O3 for spinorbitronic applications

Makarov, D.

In this presentation, we reviewed our recent activities on the fabrication and characterization of thin film and SPS-sintered Cr2O3 samples for MRAM and domain wall based memory applications.

Keywords: antiferromagnetic spintronics; Cr2O3 thin films

  • Lecture (others)
    Seminar at the University of Leipzig, Fakultät für Physik und Geowissenschaften, Felix-Bloch-Institut für Festkörperphysik, 11.05.2022, Leipzig, Germany

Permalink: https://www.hzdr.de/publications/Publ-34658
Publ.-Id: 34658


FlexiSens: 
smart magnetic field sensor technologies

Makarov, D.

In this presentation, we reviewed the topic of the cooperation between the HZDR and scia Systems GmbH. The topic concerns realization of flexible and printed magnetic field sensors.

Keywords: flexible magnetic field sensors; printable magnetic field sensors

  • Invited lecture (Conferences)
    Annual workshop for partners of scia Systems GmbH, 16.03.2022, Chemnitz, Germany

Permalink: https://www.hzdr.de/publications/Publ-34657
Publ.-Id: 34657


Magnetic control of mass transfer and convection in electrochemical processes

Weier, T.; Mutschke, G.

Outside the classical domains of magnetohydrodynamics, plasmas and
liquid metals, the action of electromagnetic forces can be observed as
well in electrolytes. The talk will start with examples on the control
of flat plate boundary layers and separated flows and discuss their
effectiveness and efficiency. Stationary as well as periodic Lorentz
forces are thematized in this context and proof to be a versatile tool
for research while high energy demand limits their applicability for
naval applications. Switching the context to electrochemical
processes, where an electrical current is inherently present,
alleviates the question of energy demand and opens-up a large field of
additional topics: Improved mass transfer can be used to increase the
limiting current density and thereby the space-time yield of
processes. Efficiency of water electrolyzers benefits from accelerated
removal of bubbles from the electrodes. Magnetic gradient forces can
assist in the build-up of nano-structured ferromagnetic layers using
comparably cheap electrochemical technology.

Keywords: magnetohydrodynamics; magnetoelectrochemistry; Lorentz force; active flow control; Particle Image Velocimetry; Finite Time Lyapunov Exponents; Proper Orthogonal Decomposition; Lagrangian Coherent Structures

  • Open Access Logo Invited lecture (Conferences) (Online presentation)
    School of Magneto-Hydro-Dynamics, 21.04.-26.05.2022, Cagliari, Italien

Permalink: https://www.hzdr.de/publications/Publ-34652
Publ.-Id: 34652


Data publication: Unusual dynamics of the ferroelectric phase transition in K1−xLixTaO3 crystals

Nuzhnyy, D.; Bovtun, V.; Buixaderas, E.; Petzelt, J.; Savinov, M.; Kempa, M.; Paściak, M.; Rafalovskyi, I.; Chelod Paingad, V.; Kužel, P.; Kamba, S.; Repček, D.; Pashkin, O.; Trepakov, V. A.; Trybuła, Z.

SHG temperature dependence and dielectric spectroscopy data on KLT measured by A. Pashkin

Keywords: second harmonic generation; THz spectroscopy

Related publications

  • Reseach data in the HZDR data repository RODARE
    Publication date: 2022-05-12
    DOI: 10.14278/rodare.1623

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Permalink: https://www.hzdr.de/publications/Publ-34651
Publ.-Id: 34651


Unusual dynamics of the ferroelectric phase transition in K1−xLixTaO3 crystals

Nuzhnyy, D.; Bovtun, V.; Buixaderas, E.; Petzelt, J.; Savinov, M.; Kempa, M.; Paściak, M.; Rafalovskyi, I.; Chelod Paingad, V.; Kužel, P.; Kamba, S.; Repček, D.; Pashkin, O.; Trepakov, V. A.; Trybuła, Z.

K1−xLixTaO3 (x=0.043, 0.08) crystals, characterized by pyroelectric current with calculated spontaneous polarization and zero-field second-harmonic generation, have been studied by broadband dielectric spectroscopy, including time-domain terahertz transmission and infrared (IR) reflectivity, and by polarized Raman spectroscopy in the 10–300 K temperature range. This multiexperimental approach has proven the percolative nature of the ferroelectric (FE) transition at low temperatures and demonstrated that the FE phase is inherently inhomogeneous and displays coexistence of FE and relaxor regions. Thanks to the very broad frequency range studied (from 1 Hz to 20 THz), the relevant excitations were identified and fitted in the dielectric response of both crystals: three relaxations, a central mode (CM), and a soft mode (SM) that splits into three components on cooling. Two Cole-Cole relaxations (assigned to flipping of polar nanoregions around the Li+ ions by π/2 and π, in agreement with the known literature), thermally activated below ∼150K, but staying in the gigahertz range at higher temperatures, do not show any frequency anomaly at the FE transition and are therefore related to the non-FE parts of the sample volume. A third thermally activated relaxation of unusually slow dynamics was revealed at low frequencies and preliminary assigned to an expected critical relaxation connected with the percolative nature of the FE phase transition. The IR SM, which undergoes much less softening than in the undoped KTaO3, splits into three components below the FE transition. Two higher-frequency components correspond to the FE volume part of the crystals assigned to the split A1 and E modes due to the cubic-tetragonal transition. The third low-frequency component is assigned to the non-FE (relaxor) volume part. Our assignment was confirmed by modeling the terahertz-IR response of the SM using the Bruggeman model within the effective medium approach. Below the SM response, an additional CM in the 1011Hz range in the whole temperature range is inferred from the fits.

Related publications

Permalink: https://www.hzdr.de/publications/Publ-34644
Publ.-Id: 34644


Intensity scaling limitations of laser-driven proton acceleration in the TNSA-regime

Keppler, S.; Elkina, N.; Becker, G. A.; Hein, J.; Hornung, M.; Mäusezahl, M.; Rödel, C.; Tamer, I.; Zepf, M.; Kaluza, M. C.

We report on experimental results on laser-driven proton acceleration using high-intensity laser pulses. We present power law scalings of the maximum proton energy with laser pulse energy and show that the scaling exponent ξ strongly depends on the scale length of the preplasma, which is affected by the temporal intensity contrast. At lower laser intensities, a shortening of the scale length leads to a transition from a square root toward a linear scaling. Above a certain threshold, however, a significant deviation from this scaling is observed. Two-dimensional particle-in-cell simulations show that, in this case, the electric field accelerating the ions is generated earlier and has a higher amplitude. However, since the acceleration process starts earlier as well, the fastest protons outrun the region of highest field strength, ultimately rendering the acceleration less effective. Our investigations thus point to a principle limitation of the proton energy in the target normal sheath acceleration regime, which would explain why a significant increase of the maximum proton energy above the limit of 100 MeV has not yet been achieved.

Keywords: laser; plasma; TNSA; particle-in-cell simulation; preplasma

Permalink: https://www.hzdr.de/publications/Publ-34642
Publ.-Id: 34642


V0036: Chemical Flowers: buoyancy-driven instabilities under modulated gravity

Stergiou, Y.; Horvath, D.; Schuszter, G.; Hauser, M.; de Wit, A.; Eckert, K.; Schwarzenberger, K.

In this video, we present experiments of a miscible reactive horizontal displacement in a radial Hele-Shaw cell under modulating gravity levels.Initially, the Hele-Shaw cells are filled with a colorless solution of KSCN, and the injected fluid is a colorless solution of FeNO3. When the two solutions react, a complex ion (FeSCN2+) forms resulting in a red-colored product solution. Due to the direct visualization of the formed product using a white LED light array and a monochrome camera, this chemical system is convenient to study reaction-diffusion-convection fronts [1]. The gravity modulations were achieved aboard the 73rd ESA Parabolic Flight Campaign that took place in October, 2020 in Paderborn, Germany. The parabolic flight allowed for experiments under micro-g, normal-g and hyper-g conditions and the transition between them. These experiments provided detailed insights in a previously investigated [2] buoyancy-driven instability. In particular, the effect of hyper-g and multiaxial acceleration on the pattern formation was revealed. The observation of the system under micro-g confirmed that no instability develops in the absence of buoyancy effects.

[1] A. Tóth, G. Schuszter, N.P. Das, E. Lantos, D. Horváth, A. De Wit, F. Brau, Effects of radial injection and solution thickness on the dynamics of confined A+ B→ C chemical fronts. Phys Chem Chem Phys, 22(18), 2020

[2] F. Haudin, L. A. Riolfo, B. Knaepen, G. M. Homsy, A. De Wit. Experimental study of a buoyancy-driven instability of a miscible horizontal displacement in a Hele-Shaw cell. Phys. Fluids, 26(4), 2014

Permalink: https://www.hzdr.de/publications/Publ-34641
Publ.-Id: 34641


Tuning of the Dzyaloshinskii-Moriya interaction by He+ion irradiation

Nembach, H. T.; Jué, E.; Potzger, K.; Faßbender, J.; Silva, T. J.; Shaw, J. M.

We studied the impact of He+ irradiation on the Dzyaloshinskii-Moriya interaction (DMI) in Ta/Co20Fe60B20/Pt/MgO
samples. We found that irradiation of 40 keV He+ ions increases the DMI by approximately 20% for fluences up to 2 × 1016
ions/cm2 before it decreases for higher fluence values. In contrast, the interfacial anisotropy shows a distinctly different
fluence dependence. To better understand the impact of the ion irradiation on the Ta and Pt interfaces with the
Co20Fe60B20 layer, we carried out Monte-Carlo simulations, which showed an expected increase in disorder at the
interfaces. A moderate increase in disorder increases the total number of triplets for the three-site exchange mechanism and
consequently increases the DMI. Our results demonstrate the significance of disorder for the total DMI.

Keywords: Dzyaloshinskii-Moriya interaction; Fluence dependence; Ions irradiation

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Permalink: https://www.hzdr.de/publications/Publ-34640
Publ.-Id: 34640


Chemical Behavior of Long-Lived Fission and Activation Products in the Near Field of a Nuclear Waste Repository and the Possibilities of their Retention (Vespa II)

Mayordomo, N.; Altmaier, M.; Bischofer, B.; Bosbach, D.; Gaona, X.; Hagemann, S.; Müller, K.

To ensure a reliable and long-term safety assessment of high-level radioactive waste disposal, it is essential to study the physico-chemical properties of the radionuclides within spent nuclear fuel as well as their transport behavior expected under conditions of the near- and far-field of a nuclear waste repository. Among the radionuclide inventory, long-lived mobile fission products are of high concern since they can strongly contribute to the total biosphere dose from spent nuclear fuel disposal. The collaborative project VESPA “Chemical Behavior of Long-Lived Fission and Activation Products in the Near Field of a Nuclear Waste Repository and the Possibilities of their Retention - Phase II” aims to investigate the solubility and the immobilization of Tc-99, I-129, Cs-137, and Se-79. In particular, the focus is set on (1) the source term, evaluating, e.g., the I-129 inventory together with the instant release fraction and its speciation; (2) the effect of geochemical conditions in the near-field, i.e. T, p, Eh, pH, on the processes of surface redox-mediation and secondary mineral phase formation; (3) the solution chemistry, determining solubility products, complex formation and activity coefficients of Tc(IV) in presence of anions and small organic molecules, and Se(IV), Se(0), Cs(I) and I(-I) at elevated temperature; and (4) the retention behavior of I, Se and Tc on layered double hydroxides (LDH) and Fe-corrosion products. Finally, safety analysis calculations link the obtained results and provide an enhanced confidence in predictive risk assessments.

The authors acknowledge the German Federal Ministry of Economic Affairs and Climate Action (BMWK) for the funding (02 E 11607A-D). Further information is given at https://vespa2.grs.de/.

Keywords: Fission products; Near Field; Nuclear waste repository

  • Poster
    19th Radiochemical conference, 15.-20.05.2022, Marienbad, Czech Republic

Permalink: https://www.hzdr.de/publications/Publ-34639
Publ.-Id: 34639


Tc(VII) reductive immobilization by Sn(II) pre-sorbed on alumina nanoparticles.

Mayordomo, N.; Rodríguez, D. M.; Roßberg, A.; Scheinost, A.; Müller, K.

The interaction of highly mobile radioactive elements in the spent fuel with the different technical and geological barriers of a nuclear waste repository needs quantification and mechanistic understanding to allow a reliable safety assessment.
One of the most concerning mobile fission products is Tc-99. It is a long-lived radionuclide (half-life of 0.213 million years) that is expected to occur as Tc(VII) under oxidizing conditions and as Tc(IV) under reducing conditions. The anion pertechnetate (TcO₄⁻) is the main species of Tc(VII) and it is known to be a highly mobile species since it barely interacts with mineral surfaces. On the contrary, TcO₂ is the main species of Tc(IV) and it is a hardly soluble solid. Therefore, the reduction of Tc(VII) to Tc(IV) limits the mobility of Tc in water and is triggered by reducing agents such as Fe(II) or Sn(II). [1] In a previous work, we have observed that pre-sorption of Fe(II) on alumina enabled the Tc(VII) reduction at the interface, even at low pH values when Tc(VII) reduction by Fe(II) was expected to be limited due to the low sorption of Fe(II) on alumina. [2] In this study we focus on the impact of Sn(II).
We have performed sorption experiments following a stepwise strategy to ensure that Tc(VII) reduction by Sn(II) occurred at the interface (heteroreduction). i) Sn(II) was sorbed on alumina, ii) the Sn(II) pre-sorbed on alumina solid was isolated and dried, iii) a solution of Tc(VII) was added to this modified alumina, and iv) the yield of Tc removal by Sn(II) pre-sorbed on alumina was analyzed. The resulting Tc-containing solid was analyzed by X-ray absorption spectroscopy (XAS) at the Rossendorf Beamline (ROBL) at the European Synchrotron Radiation Facility in Grenoble (France).
Re-oxidation experiments were performed in samples where Tc(VII) reduction by Sn(II) was obtained by different pathways: i) Tc(VII) direct reduction by dissolved Sn(II) (homoreduction) and ii) Tc(VII) reduction by Sn(II) pre-sorbed on alumina (heteroreduction).
The results show that Tc(VII) is reduced to Tc(IV) with a high yield (85-100% removal from solution), being maximum at pH values between 3.5 and 9.5, and minimum at pH 10. Re-oxidation studies show that Tc(IV) obtained by heteroreduction presents lower oxidation kinetics than Tc(IV) obtained by homoreduction. These results support that the presence of alumina plays an important role by preventing Tc(IV) re-oxidation.
Acknowledgements
The authors acknowledge the German Federal Ministry of Economic Affairs and Climate Action (BMWK) for the Vespa II project funding (02 E 11607B).
References
[1] Owunwanne, A., Church, L. B. & Blau, M. Effect of oxygen on the reduction of pertechnetate by Stannous ion. J. Nucl. Med. 18, 822–826 (1977).
[2] Mayordomo, N. et al. Technetium retention by gamma alumina nanoparticles and the effect of sorbed Fe2+. J. Hazard. Mater. 388, 122066 (2020).

Keywords: Techenetium; Reduction; X-ray absorption spectroscopy

  • Lecture (Conference)
    19th Radiochemical conference, 15.-20.05.2022, Marienbad, Czech Republic

Permalink: https://www.hzdr.de/publications/Publ-34638
Publ.-Id: 34638


HELIPORT Logos

Knodel, O.

The guidance system HELIPORT aims to make the components or steps of the entire life cycle of a research project at Helmholtz-Zentrum Dresden-Rossendorf (HZDR) discoverable, accessible, interoperable and reusable according to the FAIR principles. In particular, this data management solution deals with the entire lifecycle of research experiments, starting with the generation of the first digital objects, the workflows carried out and the actual publication of research results.

The initial logos of the HELIPORT platform are collected in this upload and are available as Open Access.

Keywords: HELIPORT; Logo

  • Software in the HZDR data repository RODARE
    Publication date: 2022-05-06
    DOI: 10.14278/rodare.1616
    License: CC-BY-4.0

Downloads:

Permalink: https://www.hzdr.de/publications/Publ-34636
Publ.-Id: 34636


P–Ru-Complexes with a Chelate-Bridge-Switch: A Comparison of 2-Picolyl and 2-Pyridyloxy Moieties as Bridging Ligands

Ehrlich, L.; Gericke, R.; Brendler, E.; Wagler, J.

Starting from [Ru(pyO)₂(nbd)] 1 and a N,P,N-tridentate ligand (2a: PhP(pic)₂, 2b: PhP(pyO)₂) (nbd = 2,5-norbornadiene, pic = 2-picolyl = 2-pyridylmethyl, pyO = 2-pyridyloxy = pyridine-2-olate), the compounds [PhP(μ-pic)₂(μ-pyO)Ru(κ²-pyO)] (3a) and [PhP(μ-pyO)₃Ru(κ²-pyO)] (3b), respectively, were prepared. Reaction of compounds 3 with CO and CNtBu afforded the opening of the Ru(κ²-pyO) chelate motif with the formation of compounds [PhP(μ-pic)₂(μ-pyO)Ru(κ-O-pyO)(CO)] (4a), [PhP(μ-pic)₂(μ-pyO)₂Ru(CNtBu)] (5a), [PhP(μ-pyO)₄Ru(CO)] (4b) and [PhP(μ-pyO)₄Ru(CNtBu)] (5b). In dichloromethane solution, 4a underwent a reaction with the solvent, i.e., substitution of the dangling pyO ligand by chloride with the formation of [PhP(μ-pic)₂(μ-pyO)Ru(Cl)(CO)] (6a). The new complexes 3a, 4a, 5a, 5b and 6a were characterized by single-crystal X-ray diffraction analyses and multi-nuclear (¹H, ¹³C, ³¹P) NMR spectroscopy. The different coordination behaviors of related pairs of molecules (i.e., pairs of 3, 4 and 5), which depend on the nature of the P–Ru-bridging ligand moieties (μ-pic vs. μ-pyO), were also studied via computational analyses using QTAIM (quantum theory of atoms in molecules) and NBO (natural bond orbital) approaches, as well as the NCI (non-covalent interactions descriptor) for weak intramolecular interactions.

Keywords: atoms-in-molecules; hemilabile; phosphane; ruthenium

Permalink: https://www.hzdr.de/publications/Publ-34635
Publ.-Id: 34635


Data publication: Calorimeter with Bayesian unfolding of spectra of high-flux broadband X-rays

Laso García, A.; Hannasch, A.; Molodtsova, M.; Ferrari, A.; Couperus Cabadağ, J. P.; Downer, M. C.; Irman, A.; Kraft, S.; Metzkes-Ng, J.; Naumann, L.; Prencipe, I.; Schramm, U.; Zeil, K.; Zgadzaj, R.; Ziegler, T.; Cowan, T.

Data for the publication: Calorimeter with Bayesian unfolding of spectra of high-flux broadband X-rays Containing: - Raw datasets - Source code for extracting calibrated energy information from datasets - Source code for simulations - Source code for unfolding of spectra

Keywords: Technique and instrumentation; Relativistic laser plasmas; X-rays; Bremsstrahlung

Related publications

  • Reseach data in the HZDR data repository RODARE
    Publication date: 2022-05-05
    DOI: 10.14278/rodare.1612
    License: CC-BY-4.0

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Permalink: https://www.hzdr.de/publications/Publ-34630
Publ.-Id: 34630


Local control after locally ablative, image-guided radiotherapy of oligometastases identified by Gallium-68-PSMA-Positron Emission Tomography in castration-sensitive prostate cancer patients (OLI-P)

Hölscher, T.; Baumann, M.; Kotzerke, J.; Zöphel, K.; Paulsen, F.; Müller, A.; Zips, D.; Thomas, C.; Wirth, M.; Troost, E. G. C.; Krause, M.; Löck, S.; Lohaus, F.

Progression of prostate-specific antigen (PSA) values after curative treatment of prostate
cancer patients is common. Prostate-specific membrane antigen (PSMA-) PET imaging can identify
patients with metachronous oligometastatic disease even at low PSA levels. Metastases-directed
local ablative radiotherapy (aRT) has been shown to be a safe treatment option. In this prospective
clinical trial, we evaluated local control and the pattern of tumor progression. Between 2014 and 2018,
63 patients received aRT of 89 metastases (MET) (68 lymph node (LN-)MET and 21 bony (OSS-)MET)
with one of two radiation treatment schedules: 50 Gy in 2 Gy fractions in 34 MET or 30 Gy in 10 Gy
fractions in 55 MET. The mean gross tumor volume and planning target volume were 2.2 and 14.9 mL,
respectively. The median follow-up time was 40.7 months. Local progression occurred in seven MET,
resulting in a local control rate of 93.5% after three years. Neither treatment schedule, target volume,
nor type of lesion was associated with local progression. Regional progression in the proximity to the
LN-MET was observed in 19 of 47 patients with at least one LN-MET (actuarial 59.3% free of regional
progression after 3 years). In 33 patients (52%), a distant progression was reported. The median time
to first tumor-related clinical event was 16.6 months, and 22.2% of patients had no tumor-related
clinical event after three years. A total of 14 patients (22%) had another aRT. In conclusion, local
ablative radiotherapy in patients with PSMA-PET staged oligometastatic prostate cancer may achieve
local control, but regional or distant progression is common. Further studies are warranted, e.g., to
define the optimal target volume coverage in LN-MET and OSS-MET.

Keywords: prostatic neoplasms; prospective studies; radiotherapy; image-guided; radiosurgery; positron emission tomography; prostate-specific antigen; neoplasm metastasis; local control

Permalink: https://www.hzdr.de/publications/Publ-34626
Publ.-Id: 34626


Test of the detector system for the Stopping Target Monitor of the Mu2e experiment in the presence of a high flux gamma background

Price, J.; Müller, S.; Ferrari, A.; Knodel, O.; Voigt, M.; Keshavarzi, A.; Motuk, E.; Judson, D.; Koltick, D.; Miller, J.; Plesniak, P.; Edmonds, A.; Ufer, R.; Huang, S.; Chen, J.; Chislett, R.; Lancaster, M.; Rachamin, R.; Tickle, S.; Alvarez, C.; Ginther, G.; Harkness-Brennan, L.

These data were taken to characterize the performance and test the data acquisition system of two detectors to be used to monitor the stopping target for the forth-coming Mu2e experiment at Fermilab; the High Purity Germanium (HPGe) and Lanthanum Bromide (LaBr) Detectors, in the presence of the pulsed gamma beam at ELBE. This measurement is crucial for the normalisation of the Mu2e experiment. The corresponding beamtime was carried out at the gELBE bremsstrahlung beamline of HZDR's ELBE radiation facility from April 21 to April 25, 2022 (GATE ID: 21202619-ST). The data sets represent the data taken with the LaBr detector by means of an ORTEC DSPEC 50 and a Lecroy/Teledyne HDO4104 oscilloscope.

Keywords: dataset; detector; HPGe; LaBr3; Stopping target Monitor (STM); Mu2e; gELBE; Data Mangement; DAQ; muon conversion

  • Reseach data in the HZDR data repository RODARE
    Publication date: 2022-05-05
    DOI: 10.14278/rodare.1600

Downloads:

Permalink: https://www.hzdr.de/publications/Publ-34624
Publ.-Id: 34624


Horizont 2020 Projekt: „Sodium-Zinc molten salt batteries for low-cost stationary storage“

Weber, N.

Der Vortrag gibt einen Überblick über die Erfahrungen bei der Antragstellung des Horizon 2020-Projekts SOLSTICE.

  • Invited lecture (Conferences) (Online presentation)
    Aktuelle Förderinstrumente der EU im Bereich Energie - Details, Hinweise und Erfahrungsberichte, 11.05.2022, Dresden, Deutschland

Permalink: https://www.hzdr.de/publications/Publ-34622
Publ.-Id: 34622


Natrium-Zink Salzschmelzenbatterien als stationäre Energiespeicher

Weber, N.

Der Vortrag gibt einen Überblick über das Forschungsvorhaben SOLSTICE sowie die ersten Ergebnisse.

  • Invited lecture (Conferences)
    5. Vernetzungsveranstaltung im Bereich Energieinnovation - Chancen für sächsische und ostdeutsche Akteure, 13.05.2022, Dresden, Deutschland

Permalink: https://www.hzdr.de/publications/Publ-34621
Publ.-Id: 34621


Prospects for precise predictions of $a_\mu$ in the Standard Model

Colangelo, G.; Davier, M.; El-Khadra, A. X.; Hoferichter, M.; Lehner, C.; Lellouch, L.; Mibe, T.; Roberts, B. L.; Teubner, T.; Wittig, H.; Ananthanarayan, B.; Bashir, A.; Bijnens, J.; Blum, T.; Boyle, P.; Bray-Ali, N.; Caprini, I.; Carloni Calame, C. M.; Catà, O.; Cè, M.; Charles, J.; Christ, N. H.; Curciarello, F.; Danilkin, I.; Das, D.; Deineka, O.; Della Morte, M.; Denig, A.; Detar, C. E.; Dominguez, C. A.; Eichmann, G.; Fischer, C. S.; Gérardin, A.; Giusti, D.; Golterman, M.; Gottlieb, S.; Gülpers, V.; Hagelstein, F.; Hayakawa, M.; Hermansson-Truedsson, N.; Hoid, B.-L.; Holz, S.; Izubuchi, T.; Jüttner, A.; Keshavarzi, A.; Knecht, M.; Kronfeld, A. S.; Kubis, B.; Kupść, A.; Lahert, S.; Liu, K. F.; Lüdtke, J.; Lynch, M.; Malaescu, B.; Maltman, K.; Marciano, W.; Marinković, M. K.; Masjuan, P.; Meyer, H. B.; Müller, S.; Neil, E. T.; Passera, M.; Pepe, M.; Peris, S.; Petrov, A. A.; Procura, M.; Raya, K.; Rebhan, A.; Risch, A.; Rodríguez-Sánchez, A.; Roig, P.; Sánchez-Puertas, P.; Simula, S.; Stoffer, P.; Stokes, F. M.; Sugar, R.; Tsang, J. T.; van de Water, R. S.; Vaquero Avilés-Casco, A.; Venanzoni, G.; von Hippel, G. M.; Zhang, Z.

We discuss the prospects for improving the precision on the hadronic corrections to
the anomalous magnetic moment of the muon, and the plans of the Muon g − 2 Theory
Initiative to update the Standard Model prediction.

Keywords: muon anomalous magnetic moment; g-2; a_mu

Permalink: https://www.hzdr.de/publications/Publ-34620
Publ.-Id: 34620


The Training Catalogue for Photon and Neutron Data Services

Knodel, O.; Konrad, U.; Valcarcel-Orti, A.; Padovani, A.

Education is becoming an increasingly important topic to help scientists work on photon and neutron sources. Other relevant areas such as advanced quantum technologies will also play a key role in the future.

One of the goals of ExPaNDS (European Open Science Cloud (EOSC) Photon and Neutron Data Service) is to train research scientists in order to better understand the issues, methods and available computational RI infrastructures to address critical research questions.

Our PaN-training catalogue provides a one-stop shop for trainers and trainees to discover online information and content:

* For trainers the catalogue offers an environment for sharing materials and event information.
* For trainees, it offers a convenient gateway via which to identify relevant training events and resources, and to perform specific, guided analysis tasks via training workflows to provide FAIR research.

Keywords: training; photon science; neutron science; e-learning; catalogue; data management

  • Open Access Logo Poster
    LEAPS meets Quantum Technology Conference, 15.-21.05.2022, La Biodola Bay, Elba Island, Italy
    DOI: 10.5281/zenodo.6491949

Permalink: https://www.hzdr.de/publications/Publ-34618
Publ.-Id: 34618


Magnetometric exploration of the phase diagrams of Yb-based delafossites

Luther, S.

The Yb-based delafossites NaYbCh2 (Ch = O, S, Se) are planar triangular-lattice spin systems with a trigonal crystal structure (space group R-3m). In these compounds, a strong spin-orbit coupling, combined with crystalline-electric-field effects, leads to a pronounced magnetic anisotropy and a pseudospin-1/2 spin-liquid ground state at low temperatures. The chalcogen series provides the possibility for tuning the interlayer distance and the associated exchange couplings by changing the chemical composition. The absence of magnetic long-range order at zero field down to lowest temperatures is strongly suggestive of a quantum spin-liquid ground state. Relaxation measurements by means of µSR and NMR have shown persistent strong fluctuations down to 100 mK at low magnetic fields. Based on specific-heat and magnetization experiments, we have observed magnetic order for out-of-plane fields exceeding 2 T for all three compounds. For in-plane fields of several tesla, a plateau-like feature in the magnetization indicates an up-up-down spin arrangement [1-3]. Furthermore, our measurements up to fields of 30 T allow to probe the saturation fields and polarized moments and, thus, the determination of the anisotropic exchange couplings [4]. Our 23Na NMR measurements of NaYbSe2 aim to probe the microscopic details of the field-induced magnetic structure in this compound. Measurements of the field-dependent transition temperature to long-range order via the 1/𝑇1-relaxation rate are in agreement with the specific-heat results. The in-plane up-up-down spin arrangement is leading to an asymmetric broadening of the NMR spectra. At elevated out-of-plane fields, an umbrella-type configuration of the magnetic moments is predicted and in agreement with a symmetric broadening of the 23Na NMR spectra. Low-field measurements reveal a monotonic low-temperature increase of the 1/𝑇1-relaxation rate and spectral broadening, without any signature of long-range order down to 0.3 K.

[1] M. Baenitz et al., Phys. Rev. B 98, 220409(R) (2018)
[2] K. M. Ranjith et al., Phys. Rev. B 99, 180401(R) (2019)
[3] K. M. Ranjith et al., Phys. Rev. B 100, 224417 (2019)
[4] B. Schmidt et al., Phys. Rev. B 103, 214445 (2021)

  • Lecture (others)
    IFPM Seminar, 17.05.2022, Dresden, Deutschland

Permalink: https://www.hzdr.de/publications/Publ-34616
Publ.-Id: 34616


A quasi-bivariate approach to tracking secondary particle properties within the class method framework

Lucas, D.; Niemi, T.; Peltola, J.; Schlegel, F.

In many polydisperse multiphase flows, the fluid or solid particles are not only distributed over size, but also with respect to other variables such as their velocity, shape, temperature or chemical composition, in which case the corresponding population balance is referred to as bi- or multivariate, respectively as two- or multidimensional. While industrial Computational Fluid Dynamics (CFD) simulations of disperse multiphase flows increasingly include approximate solutions of univariate population balance equations, e.g. for tracking the particle size distribution by means of class or quadrature-based moment methods, bivariate solution approaches are still a subject of research. This contribution highlights an aspect of recently published work (Lehnigk et al. 2022) [1], wherein a quasi-bivariate approach to tracking secondary particle properties in the class method framework is presented and demonstrated for the simulation of a bubbly flow in a vertical pipe as well as the synthesis of titania powder in a furnace reactor. In the former case, the velocity is selected as secondary property, since shear in the liquid phase can result in a pronounced radial separation of bubbles depending on their size. For the latter case, the surface area to volume ratio of the particle aggregates is used to describe the fractal-like shape of the aggregates, which influences the collision frequency and by extension also the aggregate size distribution.

[1] R. Lehnigk, W. Bainbridge, Y. Liao, D. Lucas, T. Niemi, J. Peltola, F. Schlegel, An open-source population balance modeling framework for the simulation of polydisperse multiphase flows, AIChe J. 68[3] (2022) e17539. https://doi.org/10.1002/aic.17539.

  • Poster
    7th International Conference on Population Balance Modelling (PBM 2022), 09.-11.05.2022, Lyon, Frankreich

Permalink: https://www.hzdr.de/publications/Publ-34615
Publ.-Id: 34615


The Influence Of Surface Cover And Bedrock Geology On The Snow Geochemistry – An Example From Northern Finland

Taivalkoski, A.; Pospiech, S.; Middleton, M.; Lahaye, Y.; Kinnunen, J.

The idea of using snow in mineral exploration is due to the needs of environmentally friendly sampling methods for the ecologically sensitive northern areas. Not only the environmental issues, but the low costs of sampling and relieving permission issues encourage researchers to find new methods for mineral exploration. Surface geochemical methods, including sampling plants, topsoil horizons and snow can be considered in the areas where machinery is not allowed. Moreover, surface geochemical methods can provide the information of metal ions derived from the deep-seated mineralization below. The advantages of snow sampling are low volume of sample material, (comparably) light sample material and sampling equipment and therefore the option for low impact sampling campaign by skies or snowshoes.
In the New Exploration Technologies (NEXT) project*, 165 snow samples together with 13 field duplicate snow samples for quality control, were collected in March-April winter 2019. The aim was to estimate with statistical methods the usage of snow as a sampling material for mineral exploration. The samples were collected on the Rajapalot Au-Co prospect in northern Finland, 60 km west from Rovaniemi, operated by Mawson Oy. Stratified random sampling method was used to calculate sampling locations with balanced number of points per soil type and geophysical parameter, but randomly distributedwithin the strata over the test area. The samples were analysed in the Research Laboratory of the Geological Survey of Finland using a Nu AttoM single collector inductively coupled plasma mass spectrometry (SC-ICPMS) and returned analytical results for 52 elements at ppt level.
Of the analysed elements Ba, Ca, Li, Mg, Mo, Rb, Sr and V passed the strict quality control and were used for the final data analysis. Prior to statistical methods, the geochemical data was transformed to log-ratio scores in order to ensure that results are independent of the selection of elements and to avoid spurious correlations (compositional data approach). The results indicate strong dependency of the snow element composition to the soil type, meaning that there is systematic shift of element pattern if the snow sample was taken above mineral soil or organic soil. Thus, the soil type should be included in models to predict (geological) features below the surface or interpretation of snow data should be performed separately for different soil types. The impact of subsurface features on the snow geochemistry could only be tested indirectly by using geophysical data as proxy for characteristics of the basement rock. Based on linear models, it seems that snow geochemistry could be used as a mapping tool for delineating the areas of major geological units. Given the selection of analytical available elements, snow sampling could serve as a proxy where to continue exploration with different methods rather than directly pointing out the mineralized zones.

Keywords: snow; exploration; geochemistry; statistics; compositional data

  • Lecture (Conference)
    Nordic Geological Winter Meeting, Reykjavik, 11.-13.05.2022, Reykjavik, Iceland

Permalink: https://www.hzdr.de/publications/Publ-34613
Publ.-Id: 34613


A Scalable 5,6-Qubit Grover's Quantum Search Algorithm

Vemula, D. R.; Konar, D.; Satheesan, S.; Cangi, A.

Recent studies have been spurred on by the promise of advanced quantum computing technology, which has led to the development of quantum computer simulations on classical hardware. Grover's quantum search algorithm is one of the well-known applications of quantum computing, enabling quantum computers to perform a database search (unsorted array) and quadratically outperform their classical counterparts in terms of time. Given the restricted access to database search for an oracle model (black-box), researchers have demonstrated various implementations of Grover's circuit for two to four qubits on various platforms. However, larger search spaces have not yet been explored. In this paper, a scalable Quantum Grover Search algorithm is introduced and implemented using 5-qubit and 6-qubit quantum circuits, along with a design pattern for ease of building an Oracle for a higher order of qubits. For our implementation, the probability of finding the correct entity is in the high nineties. The accuracy of the proposed 5-qubit and 6-qubit circuits is benchmarked against the state-of-the-art implementations for 3-qubit and 4-qubit. Furthermore, the reusability of the proposed quantum circuits using subroutines is also illustrated by the opportunity for large-scale implementation of quantum algorithms in the future.

Keywords: Quantum Computing; Grover’s search algorithm; IBM quantum computer; qubit

Permalink: https://www.hzdr.de/publications/Publ-34612
Publ.-Id: 34612


Combining a SIMS with AMS: Super-SIMS at DREAMS - Status of this challenging initiative

Rugel, G.

At the DREAMS (DREsden AMS) facility [1,2] we are implementing a so-called Super-SIMS (SIMS =
Secondary Ion Mass Spectrometry) device [3] for specialized applications. The system combines the spatial
resolution capability of a commercial SIMS (CAMECA IMS 7f-auto) with AMS capability, which should
suppress molecular isobars in the ion beam allowing for the quantification of elemental abundances down to
~ E-9 - E-12. This would be more than an order of magnitude improvement over traditional dynamic SIMS
(e.g. [4,5]). We aim to use this for the highly sensitive analysis of geological samples in the context of
resource technology.
In the present setup, high efficiency transmission in the low-energy ion optics segment remains a challenge,
as the beam needs to traverse two existing magnet chambers without deflection, where no steering or lens
elements are available over a flight distance of 4 m. We have now improved the low-energy injection just
after the ion beam exits the 7f-auto, upgrading the steerers directly after the SIMS and by adding a beam
intensity attenuator. This provides both more stable conditions for instrument tuning and simplifies transition
between measurements of the beam intensity in Faraday cups and the gas ionization chamber. Regarding the
measurement of C, N and O in silicon, we found that a simple Wien-filter using permanent magnets for the
primary Cs-sputter beam significantly reduces the background at the detector, as the 7f-auto uses a Cs₂ CO₃
source – rather than metallic Cs – for the generation of the primary positive Cs beam.
Once the remaining issues associated with ion beam-path are fully addressed, we will still need to tackle the
issue of establishing suitable, well characterized reference materials needed for our first suite of resource and
geoscience applications (e.g., halides in naturally occurring sulphide minerals). We present ongoing
developments and results, as well as plans for extending to other matrices and isotope systems.
[1] S. Akhmadaliev et al., NIMB 294 (2013) 5. [2] G. Rugel et al. NIMB 370 (2016) 94. [3] J. M. Anthony,
D. J. Donahue, A. J. T. Jull, MRS Proceedings 69 (1986) 311-316. [4] C. Maden, PhD thesis, ETH Zurich
2003. [5] S. Matteson, Mass Spectrom. Rev., 27 (2008) 470.

  • Invited lecture (Conferences) (Online presentation)
    National Workshop on "Chronological systematics and their applications in Earth Sciences", 19.-21.04.2022, New Delhi, India

Permalink: https://www.hzdr.de/publications/Publ-34610
Publ.-Id: 34610


Data Publication: Protein Enrichment by Foam Fractionation: Experiment and Modeling

Keshavarzi, B.; Krause, T.; Sikandar, S.; Schwarzenberger, K.; Eckert, K.; Ansorge-Schumacher, M.; Heitkam, S.

This work investigates the enrichment of bovine serum albumin (BSA) protein through foam fractionation. Here, we performed experiments using BSA and measured the recovery and grade of the extract. Additionally, an unsteady-state simulation of the protein foam fractionation process was carried out by numerically solving the liquid drainage equation in the foam. Thereby, the extracted liquid volume and protein concentration were calculated. Required quantities such as foam stability, interface coverage or bubble size distribution were measured in corresponding experiments and were fed into the model. The experiments showed that the foam coalescence accelerates the liquid drainage leading to dryer extract and higher protein enrichment. The modeling also reproduced the liquid recovery and extract concentration of the foam fractionation tests within a reasonable error range. The modeling solely relies on experimental inputs and does not require any tuning parameters. It can be further used for optimization or up-scaling of protein foam fractionation.

Keywords: Protein; foam fractionation; flotation; modeling; dynamic adsorption; surface equation of state; flow-on-bubble

Related publications

  • Reseach data in the HZDR data repository RODARE
    Publication date: 2022-05-10
    DOI: 10.14278/rodare.1557

Downloads:

Permalink: https://www.hzdr.de/publications/Publ-34609
Publ.-Id: 34609


Protein Enrichment by Foam Fractionation: Experiment and Modeling

Keshavarzi, B.; Krause, T.; Sikandar, S.; Schwarzenberger, K.; Eckert, K.; Ansorge-Schumacher, M.; Heitkam, S.

This work investigates the enrichment of bovine serum albumin (BSA) protein through foam fractionation. Here, we performed experiments using BSA and measured the recovery and grade of the extract. Additionally, an unsteady-state simulation of the protein foam fractionation process was carried out by numerically solving the liquid drainage equation in the foam. Thereby, the extracted liquid volume and protein concentration were calculated. Required quantities such as foam stability, interface coverage or bubble size distribution were measured in corresponding experiments and were fed into the model. The experiments showed that the foam coalescence accelerates the liquid drainage leading to dryer extract and higher protein enrichment. The modeling also reproduced the liquid recovery and extract concentration of the foam fractionation tests within a reasonable error range. The modeling solely relies on experimental inputs and does not require any tuning parameters. It can be further used for optimization or up-scaling of protein foam fractionation.

Keywords: Protein; foam fractionation; flotation; modeling; dynamic adsorption; surface equation of state; flow-on-bubble

Related publications

Downloads:

  • Secondary publication expected from 09.05.2023

Permalink: https://www.hzdr.de/publications/Publ-34606
Publ.-Id: 34606


Targeting CD10 on B-Cell Leukemia Using the Universal CAR T-Cell Platform (UniCAR)

Mitwasi, N.; Arndt, C.; Rodrigues Loureiro, L. R.; Kegler, A.; Fasslrinner, F.; Berndt, N.; Bergmann, R.; HoˇRejší, V.; Rössig, C.; Bachmann, M.; Feldmann, A.

Chimeric antigen receptor (CAR)-expressing T-cells are without a doubt a breakthrough therapy for hematological malignancies. Despite their success, clinical experience has revealed several challenges, which include relapse after targeting single antigens such as CD19 in the case of B-cell acute lymphoblastic leukemia (B-ALL), and the occurrence of side effects that could be severe in some cases. Therefore, it became clear that improved safety approaches, and targeting multiple antigens, should be considered to further improve CAR T-cell therapy for B-ALL. In this paper, we address both issues by investigating the use of CD10 as a therapeutic target for B-ALL with our switchable UniCAR system. The UniCAR platform is a modular platform that depends on the presence of two elements to function. These include UniCAR T-cells and the target modules (TMs), which cross-link the T-cells to their respective targets on tumor cells. The TMs function as keys that control the switchability of UniCAR T-cells. Here, we demonstrate that UniCAR T-cells, armed with anti-CD10 TM, can efficiently kill B-ALL cell lines, as well as patient-derived B-ALL blasts, thereby highlighting the exciting possibility for using CD10 as an emerging therapeutic target for B-cell malignancies.

Keywords: CD10; immunotherapy; CAR T-cells

  • Open Access Logo International Journal of Molecular Sciences 23(2022)9, 4920
    Online First (2022) DOI: 10.3390/ijms23094920

Downloads:

Permalink: https://www.hzdr.de/publications/Publ-34603
Publ.-Id: 34603


Teaching Workshop: Software Carpentry Workshop, Unix shell, Git, and Programming with Python

Zongru Doris Shao, R. H.

Teaching Software Carpentry Workshop

Keywords: Python; Git; Shell

  • Open Access Logo Lecture (others) (Online presentation)
    Software Carpentry Workshop, 16.-19.05.2022, University of Twente, online, Netherlands

Downloads:

Permalink: https://www.hzdr.de/publications/Publ-34602
Publ.-Id: 34602


Therapeutic potential of repetitive AC-magnetic treatments on iPSC-derived motoneurons from ALS patients to improve axonal regeneration

Kandhavivorn, W.

lecture seminar for Ph.D. candidates at Center for Radiopharmaceutical Tumor Research (ZRT), HZDR
es hat keine Inhaltsangabe dafür vorgelegen

  • Lecture (others) (Online presentation)
    Lecture Seminar for Ph.D. candidates at Center for Radiopharmaceutical Tumor Research (ZRT), HZDR, 25.04.2022, Dresden, Deutschland

Permalink: https://www.hzdr.de/publications/Publ-34600
Publ.-Id: 34600


The application of AC-magnetic stimulations on iPSC-derived motoneurons from ALS patients to improve axonal regeneration for therapeutic potential in neurodegeneration

Kandhavivorn, W.

lecture in EGBE 693 Research Seminar for Biomedical Engineering II for graduate students at the Department of Biomedical Engineering, Faculty of Engineering, Mahidol University Thailand
es hat keine Inhaltsangabe dafür vorgelegen

  • Lecture (Conference) (Online presentation)
    EGBE 693 Research Seminar for Biomedical Engineering II for graduate students, 18.01.2022, Nakhon Pathom, Thailand

Permalink: https://www.hzdr.de/publications/Publ-34599
Publ.-Id: 34599


Radiomics-based differentiation of lung disease models generated by polluted air based on X-ray computed tomography data

Szigeti, K.; Szabó, T.; Korom, C.; Ilona, C.; Horváth, I.; Veres, D. S.; Gyöngyi, Z.; Karlinger, K.; Bergmann, R.; Pócsik, M.; Budán, F.; Máthé, D.

Background: Lung diseases (resulting from air pollution) require a widely accessible method for risk estimation and arly diagnosis to ensure proper and responsive treatment. Radiomics-based fractal dimension analysis of X-ray computed tomography attenuation patterns in chest voxels of mice exposed to different air polluting agents was performed to model early stages of disease and establish differential diagnosis.
Methods: To model different types of air pollution, BALBc/ByJ mouse groups were exposed to cigarette smoke combined with ozone, sulphur dioxide gas and a control group was established. Two weeks after exposure, the frequency distributions of image voxel attenuation data were evaluated. Specific cut-off ranges were defined to group voxels by attenuation. Cut-off ranges were binarized and their spatial pattern was associated with calculated fractal dimension, then abstracted by the fractal dimension – cut-off range mathematical function. Nonparametric
Kruskal-Wallis (KW) and Mann–Whitney post hoc (MWph) tests were used.
Results: Each cut-off range versus fractal dimension function plot was found to contain two distinctive Gaussian curves. The ratios of the Gaussian curve parameters are considerably significant and are statistically distinguishable within the three exposure groups.
Conclusions: A new radiomics evaluation method was established based on analysis of the fractal dimension of chest X-ray computed tomography data segments. The specific attenuation patterns calculated utilizing our method may diagnose and monitor certain lung diseases, such as chronic obstructive pulmonary disease (COPD), asthma, tuberculosis or lung carcinomas.

Keywords: Fractal dimension; Radiomics; In vivo micro-CT; Air pollution; Lung disease

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Permalink: https://www.hzdr.de/publications/Publ-34597
Publ.-Id: 34597


Data: Temperature Driven Transformation of the Flexible Metal-Organic Framework DUT-8(Ni)

Ehrling, S.; Senkovska, I.; Efimova, A.; Bon, V.; Abylgazina, L.; Petkov, P.; Evans, J. D.; Elsherif, A. G. A.; Thomas Wharmby, M.; Roslova, M.; Huang, Z.; Tanaka, H.; Wagner, A.; Schmidt, P.; Kaskel, S.

These are the raw data of "Temperature Driven Transformation of the Flexible Metal-Organic Framework DUT-8(Ni)"  

DUT-8(Ni) metal-organic framework belongs to the family of flexible pillared layer materials. The desolvated framework can be obtained in the open pore form (op) or in the closed pore form (cp), depending on the crystal size regime. In the present work, we report on the behaviour of desolvated DUT-8(Ni) at elevated temperatures.
For both, op and cp variants, heating causes a structural transition, leading to an new, crystalline compound, containing two
interpenetrated networks. The state of the framework before transition (op vs. cp) influences the transition temperature: the small particles of the op phase transform at significantly lower temperature in comparison to the macroparticles of the cp phase, transforming close to the decomposition temperature. The new compound, confined closed pore phase (ccp), was characterized by powder X-ray diffraction and spectroscopic techniques, such as IR, EXAFS, and positron annihilation lifetime spectroscopy (PALS). Thermal effects of structural cp to ccp transitions were studied using differential scanning calorimetry (DSC), showing an overall exothermic effect of the process, involving bond breaking and reformation. Theoretical calculations reveal the energetics, driving the observed temperature induced phase transition.

Keywords: thermal response • interpenetrated MOF • thermal effect • phase transition • bond rearrangement

  • Reseach data in the HZDR data repository RODARE
    Publication date: 2022-04-29
    DOI: 10.14278/rodare.1549
    License: CC-BY-1.0

Downloads:

Permalink: https://www.hzdr.de/publications/Publ-34595
Publ.-Id: 34595


Data: Fully encapsulated and stable black phosphorus field-effect transistors

Arora, H.; Fekri, Z.; Vekariya, Y. N.; Chava, P.; Watanabe, K.; Taniguchi, T.; Helm, M.; Erbe, A.

Fabricated devices went through electrical characterization with 4200-SCS parameter analyzer located in greyroom and Agilent 4156C Parameter Analyzer equipped with a cool-down setup located in 613. The measured data was processed with origin software.

Keywords: two-dimensional semiconductors; black phosphorus; field-effect transistors; hexagonal boron nitride; encapsulation

  • Reseach data in the HZDR data repository RODARE
    Publication date: 2022-04-29
    DOI: 10.14278/rodare.1551
    License: CC-BY-4.0

Downloads:

Permalink: https://www.hzdr.de/publications/Publ-34592
Publ.-Id: 34592


Expanding the Range: AuCu Metal Aerogels from H2O and EtOH

Georgi, M.; Kresse, J.; Hiekel, K.; Hübner, R.; Eychmüller, A.

Due to their self-supporting and nanoparticulate structure, metal aerogels have emerged as excellent electrocatalysts, especially in the light of the shift to renewable energy cycles. While a large number of synthesis parameters have already been studied in depth, only superficial attention has been paid to the solvent. In order to investigate the influence of this parameter with respect to the gelation time, crystallinity, morphology, or porosity of metal gels, AuxCuy aerogels were prepared in water and ethanol. It was shown that although gelation in water leads to highly porous gels (60 m2g-1), a CuO phase forms during this process. The undesired oxide could be selectively removed using a post-washing step with formic acid. In contrast, the solvent change to EtOH led to a halving of the gelation time and the suppression of Cu oxidation. Thus, pure Cu aerogels were synthesized in addition to various bimetallic Au3X (X = Ni, Fe, Co) gels. The faster gelation, caused by the lower permittivity of EtOH, led to the formation of thicker gel strands, which resulted in a lower porosity of the AuxCuy aerogels. The advantage given by the solvent choice simplifies the preparation of metal aerogels and provides deeper knowledge about their gelation.

Keywords: metal; aerogel; gold; copper; ethanol; water; solvent; bimetallic; porous; one-step

Permalink: https://www.hzdr.de/publications/Publ-34591
Publ.-Id: 34591


(Data set) Optical study of RbV₃Sb₅: Multiple density-wave gaps and phonon anomalies

Wenzel, M.; Ortiz, B. R.; Wilson, S. D.; Dressel, M.; Tsirlin, A. A.; Uykur, E.

The folder contains the data set that the publication with the same name is based on. 

Origin file: 

  1. Reflectivity
  2. Optical conductivity
  3. Band resolved DFT calculation (band structure + optical conductivity)
  4. Comparison of DFT and experiment (interband transitions) above and below CDW transition
  5. Further data sets are available upon request
  • Reseach data in the HZDR data repository RODARE
    Publication date: 2022-04-28
    DOI: 10.14278/rodare.1545

Downloads:

Permalink: https://www.hzdr.de/publications/Publ-34588
Publ.-Id: 34588


On the prospects of magnetic-field-assisted electrodeposition of nano-structured ferromagnetic layers

Huang, M.; Skibinska, K.; Zabinski, P.; Wojnicki, M.; Wloch, G.; Eckert, K.; Mutschke, G.

Micro- and nano-structured ferromagnetic layers are attractive for super-hydrophobic and electrocatalytic applications and can be effectively synthesized using electrodeposition. Beside the use of capping agents, magnetic fields have recently been proven to promote the growth of mm-sized conical structures by alternatively generating a supportive local flow. Here we explore the prospects of using magnetic fields to support the growth of smaller, micro-/nano-sized conical structures. We first elaborate by numerical simulations how the local electrolyte flow and the related inhomogeneous mass transfer change with shrinking cone size. Related scaling laws are derived, and stronger viscous friction along with smaller concentration changes inside the diffusion layer are found to limit the support of the magnetic field. To enhance the structuring effect, pulsed electrodeposition and use of superconducting magnets are discussed. Second, systematic experiments on the template-free electrodeposition of nickel layers in magnetic fields of different orientations and intensities are performed. Regardless of the direction, strong fields are found to promote blunt-ended, shell-like structures. These results are finally discussed by the help of numerical simulations which additionally consider the global cell flow forced by the magnetic fields. Importantly, global flow is found to dominate compared to local flow. We therefore propose improved electrode geometries for future research to clarify the prospects of stronger magnetic fields.

Keywords: ferromagnetic metal electrodeposition; magnetic field; nano-structured catalyst; numerical simulation; micro MHD effect

Permalink: https://www.hzdr.de/publications/Publ-34582
Publ.-Id: 34582


Radiopharmazie des vergangenen Jahrzehnts

Steinbach, J.; Kopka, K.

Die Radiochemiker/Radiopharmazeuten des deutschsprachigen Raums sind im Verbund der AGRR – der „Arbeitsgemeinschaft Radiochemie und Radiopharmazie“ – innerhalb der Deutschen Gesellschaft für Nuklearmedizin organisiert. Die AGRR setzt sich vorrangig aus Kolleginnen und Kollegen der D-A-CH-Länder zusammen, sodass auf radiopharmazeutischer Seite eine Anbindung an die OGNMB und SGNM besteht. Sie pflegen dort – auch mit zahlreichen Mitgliedern aus der Industrie – während der jährlichen Arbeitstagungen einen intensiven Austausch, der über die Grenzen klassischer Vortragsveranstaltungen hinausgeht und so zu einer engen Vernetzung beiträgt. Neben klassisch-fachlichen Fragen bietet die AGRR eine Plattform zur Behandlung der vielen regulatorischen Probleme, die sowohl die pharmazeutischen als auch die Strahlenschutz-bezogenen Herausforderungen zur sicheren Versorgung der Nuklearmedizin mit anwendungsfertigen Radiopharmaka mit sich bringen.

Permalink: https://www.hzdr.de/publications/Publ-34581
Publ.-Id: 34581


New concepts for recovery of metals from wastes using biological means

Pollmann, K.; Lederer, F.; Schönberger, N.; Jain, R.; Chakankar, M. V.; Kutschke, S.

The development of new technologies, especially in the field of renewable energies, has led to an increase in the demand for essential metals in recent years. At the same time, the extraction of these metals is not always environmentally friendly. Toxic metals can pollute waters and enter the environment both during extraction and processing or through disposal. Therefore, new environmentally friendly technologies are needed that prevent their entry into the environment or efficiently contribute to the recovery and recycling of the elements. Biotechnology can contribute to this.
Such technologies exploit the natural ability of organisms, bio-components, and biomolecules to interact with metals. Furthermore, modern methods of molecular biology and synthetic biology enable the development of tailored biomolecules that interact with metal ions or surfaces. In this talk, some of these modern biotechnological concepts for metal extraction such as bioleaching, bioflotation, biosorption from various primary and secondary raw materials as well as for treatment of metal contaminated waste waters will be presented.

  • Lecture (Conference) (Online presentation)
    ACS Spring 2022, 20.-24.03.2022, San Diego, CA, USA

Permalink: https://www.hzdr.de/publications/Publ-34578
Publ.-Id: 34578


alpaka-group/alpaka: alpaka 0.9.0: The SYCL Complex

Bastrakov, S.; Bocci, A.; Di Pilato, A.; Ehrig, S.; Gruber, B. M.; Hübl, A.; Kelling, J.; Pantaleo, F.; Stephan, J.; Vyskocil, J.; Widera, R.; Worpitz, B.

The alpaka library is a header-only C++17 abstraction library for accelerator development. Its aim is to provide performance portability across accelerators through the abstraction (not hiding!) of the underlying levels of parallelism.

Keywords: CUDA; HPC; alpaka; OpenMP; HIP; C++; GPU; heterogeneous computing; performance portability; FPGA; SYCL

  • Software in external data repository
    Publication year 2022
    Programming language: C++
    System requirements: OS: Linux, Windows, or macOS Software requirements: C++17 compiler, Boost 1.74.0+, CMake 3.18+
    License: MPL-2.0 (Link to license text)
    Hosted on GitHub: Link to location
    DOI: 10.5281/zenodo.6475608

Permalink: https://www.hzdr.de/publications/Publ-34571
Publ.-Id: 34571


Differences in the critical dynamics underlying the human and fruit-fly connectome

Géza, Ó.; Gustavo, D.; Kelling, J.

Previous simulation studies on human connectomes suggested that critical dynamics emerge subcritically in the so-called Griffiths phases. Now we investigate this on the largest available brain network, the 21662 node fruit-fly connectome, using the Kuramoto synchronization model. As this graph is less heterogeneous, lacking modular structure and exhibiting high topological dimension, we expect a difference from the previous results. Indeed, the synchronization transition is mean-field-like, and the width of the transition region is larger than in random graphs, but much smaller than as for the KKI-18 human connectome. This demonstrates the effect of modular structure and dimension on the dynamics, providing a basis for better understanding the complex critical dynamics of humans.

Keywords: Critical phenomena; Dynamical phase transitions; Neuronal dynamics; Neuronal network activity; Nonequilibrium statistical mechanics; Synchronization transition

Permalink: https://www.hzdr.de/publications/Publ-34568
Publ.-Id: 34568


Development of a Copper-free Click-Radiolabeling for 99mTc-Tricarbonyl Complexes

Schlesinger, M.

Click chemistry, and in particular copper-free click reactions, have gained growing interest in the field of radiopharmaceutical sciences. The 99mTc-tricarbonyl moiety is an excellent precursor for radiolabelling of biomolecules. This master thesis aims at synthesizing two new chelators containing the 2,2’-dipicolylamine (DPA) moiety for 99mTc and investigating the copper-free strain-promoted cycloaddition for the Tc(CO)3-core. The first chelator was based on a tetrafluorophenyl ester and was successfully radiolabeled with [99mTc][Tc(CO)3(H2O)3]+ at 40°C with a a radiochemical conversion (RCC) of 89% after 20 min. The chelator was afforded in a radiochemical purity over 99% after separation using a cartridge. The subsequent conjugation of an amine-functionalized PSMA (prostate-specific membrane antigen) targeting motif was investigated, and the PSMA targeting 99mTc-complex was afforded with an RCC of 23% at 100°C after 150 min. Two other unknown side products were observed. Further in-depth studies are required to optimize the radiolabeling and to identify the formed side-products. For the SPAAC reaction, a 4,8-diazacyclononyne containing the DPA moiety was prepared via the Nicholas reaction. Radiolabeling at 100°C afforded the radiolabeled complex with an RCC of 89% after 30 min. The ensuing SPAAC reaction with an azide-functionalized PSMA motif was studied at three different temperatures. The PSMA targeting 99mTc-complex was afforded selectively at 100°C after 4 hours with an RCC of 89%. No side products were observed. Nonradioactive Re(CO)3-complexes were synthesized and characterized to confirm the 99mTc-complexes. Further modifications of the 4,8-diazacyclononyne could prospectively enable to carry out the radiolabeling under physiological conditions. Continuing in vitro and in vivo experiments are planned.

Keywords: technetium-99m; click reaction; strainpromoted; tricarbonyl complex

  • Master thesis
    Universität Leipzig, 2022
    Mentor: PD Dr. habil. Constantin Mamat
    122 Seiten

Permalink: https://www.hzdr.de/publications/Publ-34560
Publ.-Id: 34560


High-field magnetization studies and their analysis in RFe11Ti and RFe11TiH1 rare-earth intermetallics (an example: HoFe11TiHx, x = 0 and 1)

Kostyuchenko, N. V.; Tereshina, I. S.; Tereshina-Chitrova, E. A.; Skoursky, J.; Doerr, M.; Zvezdin, A. K.; Drulis, H.

We present experimental high-field magnetization studies for the single-crystalline ferrimagnetic RFeTi compounds at example of holmium-based hydride in order to evaluate, compare and analyze the crystal-field and exchange parameters. We predict theoretically the magnetization behavior of HoFe11Ti up to 80 T magnetic field for the first time. The results are compared with data for the parent compound HoFe11TiH1 and those with erbium and thulium (x = 0 and 1).

Permalink: https://www.hzdr.de/publications/Publ-34558
Publ.-Id: 34558


Fermi surface of a system with strong valence fluctuations: Evidence for a noninteger count of valence electrons in EuIr2Si2

Götze, K.; Bergk, B.; Ignatchik, O.; Polyakov, A.; Kraft, I.; Lorenz, V.; Rosner, H.; Förster, T.; Seiro, S.; Sheikin, I.; Wosnitza, J.; Geibel, C.

We present de Haas-van Alphen (dHvA) measurements on an Eu-based valence-fluctuating system. EuIr2Si2 exhibits a temperature-dependent, noninteger europium valence with Eu2.8+ at low temperatures. The comparison of experimental results from our magnetic-torque experiments in fields up to 32 T and density functional theory band-structure calculations with localized 4f electrons shows that the best agreement is reached for a Fermi surface based on a valence of Eu2.8+. The calculated quantum-oscillation frequencies for Eu3+ instead cannot explain all the experimentally observed frequencies. The effective masses, derived from the temperature dependence of the dHvA oscillation amplitudes, show not only a significant enhancement with masses up to 11 me (me being the free electron mass), but also a magnetic-field dependence of the heaviest mass. We attribute the formation of these heavy masses to strong correlation effects resulting from valence fluctuations of 4f electrons being strongly hybridized with conduction electrons. The increase of the heavy masses with magnetic field likely results from the onset of the expected field-induced valence crossover that enhances these valence fluctuations but does not alter the Fermi-surface topology in the field range studied.

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Permalink: https://www.hzdr.de/publications/Publ-34557
Publ.-Id: 34557


Collinear order in the spin-5/2 triangular-lattice antiferromagnet Na3Fe(PO4)2

Sebastian, S. J.; Islam, S. S.; Jain, A.; Yusuf, S. M.; Uhlarz, M.; Nath, R.

We set forth the structural and magnetic properties of the frustrated spin-5/2 triangle lattice antiferromagnet Na3Fe(PO4)2 examined via x-ray diffraction, magnetization, heat capacity, and neutron diffraction measurements on the polycrystalline sample. No structural distortion was detected from the temperature-dependent x-ray diffraction down to 12.5 K, except a systematic lattice contraction. The magnetic susceptibility at high temperatures agrees well with the high-temperature series expansion for a spin-5/2 isotropic triangular lattice antiferromagnet with an average exchange coupling of J/kB ≃ 1.8 K rather than a one-dimensional spin-5/2 chain model. This value of the exchange coupling is consistently reproduced by the saturation field of the pulse field magnetization data. It undergoes a magnetic long-range order at TN ≃ 10.4 K. Neutron diffraction experiments elucidate a collinear antiferromagnetic ordering below TN with the propagation vector k = (1, 0, 0). An intermediate value of frustration ratio ( f ≃ 3.6) reflects moderate frustration in the compound which is corroborated by a reduced ordered magnetic moment of ∼1.52μB at 1.6 K, compared to its classical value (5μB). Magnetic isotherms exhibit a change of slope envisaging a field induced spin-flop transition at HSF ≃ 3.2 T. The magnetic field vs temperature phase diagram clearly unfold three distinct phase regimes, reminiscent of a frustrated magnet with in-plane (XY-type) anisotropy.

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Permalink: https://www.hzdr.de/publications/Publ-34556
Publ.-Id: 34556


Top-down fabrication of silicon photonic structures for hosting single-photon emitters

Jagtap, N.; Hollenbach, M.; Fowley, C.; Berencen, Y.; Lee, W.; Astakhov, G.; Erbe, A.; Helm, M.

Silicon, the ubiquitous material for computer chips, has recently been shown to be instrumental for hosting sources of single-photons emitting in the strategic optical telecommunication O-band (1260-1360 nm)[1], the so-called G center. To increase the brightness and the photon extraction efficiency of single G center, the coupling of these centers into photonic structures is strong. This work presents a top-down approach avoiding the use of ion beam-based etching methods for fabricating high-quality defect-free photonic structures such as silicon nanopillars, which can host singlephoton emitters. This method builds upon a wet-chemical process known as metal-assisted chemical etching. We report the successful fabrication of two-dimensional arrays of vertically-directed waveguiding silicon nanopillars. We also show the etch chemistry dependence on the Si wafer resistivity along with its effect on the etch rate and the sidewall roughness of pillars for a variety of pillar diameters.
References:[1] M. Hollenbach, et al. Opt. Express 28,26111-26121

  • Open Access Logo Poster (Online presentation)
    virtual DPG-Frühjahrstagungen (DPG Spring Meetings) 2021, 27.-30.09.2021, Online, Germany

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Permalink: https://www.hzdr.de/publications/Publ-34549
Publ.-Id: 34549


Top down Fabrication of Silicon Photonic Structures by Metal Assisted Chemical Etching

Jagtap, N.

Silicon, the ubiquitous material for computer chips, has recently been shown to be instrumental for hosting sources of single-photons emitting in the strategic optical telecommunication O-band (1260-1360 nm)[1], the so-called G center. To increase the brightness and the photon extraction efficiency of single G center, the coupling of these centers into photonic structures is strong.
This work presents a top-down approach avoiding the use of ion beam-based etching methods for fabricating high-quality defect-free photonic structures such as silicon nanopillars, which can host single photon emitters. This method builds upon a wet-chemical process known as MACEtch. We report the successful fabrication of two-dimensional arrays of vertically directed wave guiding silicon nanopillars. The confocal microscopy after carbon ion implantation shows presence of ensembles of G centers.

  • Open Access Logo Lecture (Conference)
    NANONET Annual Workshop 2021, 21.-23.09.2021, Klingenberg, Germany

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Permalink: https://www.hzdr.de/publications/Publ-34548
Publ.-Id: 34548


Biohydrometallurgy in e-waste recycling

Lederer, F.

E-waste recycling starts to focus more on biological methods that are developed in only a few institutes. The Biotechnology devision at Helmholtz Institute Freiberg for Resource Technology focusses on three main research approaches called bioflotation, biosorption and bioleaching. All these techniques and examples out of litereature and the lab are shown in this lecture.

Keywords: biomolecules; bacteria; e-waste; siderophores; peptides

  • Invited lecture (Conferences) (Online presentation)
    Urban mining lectures, 25.3.2022, Vancouver, Canada

Permalink: https://www.hzdr.de/publications/Publ-34546
Publ.-Id: 34546


Syntetic Spectra Data used in publication "Differential evolution optimization of Rutherford back-scattering spectra"

Heller, R.; Meersschaut, J.; Claessens, N.; Merckling, C.; Klingner, N.

The zip-file contains all synthetic spectra as used for and  described in the publication "Differential evolution optimization of Rutherford back-scattering spectra" and all simulation input files for the code RUTHELDE presented therein. Naming according to the text in the paper. All files are in human readable ASCII format. The simulation input files can be best viewed with any kind of JSON file editor.

  • Reseach data in the HZDR data repository RODARE
    Publication date: 2022-04-14
    DOI: 10.14278/rodare.1541
    License: CC-BY-4.0

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Permalink: https://www.hzdr.de/publications/Publ-34545
Publ.-Id: 34545


Multi-Center Magnon Excitations Open the Entire Brillouin Zone to Terahertz Magnetometry of Quantum Magnets

Biesner, T.; Roh, S.; Razpopov, A.; Willwater, J.; Süllow, S.; Li, Y.; Zoch, K. M.; Medarde, M.; Nuss, J.; Gorbunov, D.; Scurschii, I.; Pustogow, A.; Brown, S. E.; Krellner, C.; Valenti, R.; Puphal, P.; Dressel, M.

Due to the small photon momentum, optical spectroscopy commonly probes magnetic excitations only at the center of the Brillouin zone; however, there are ways to override this restriction. In case of the distorted kagome quantum magnet Y-kapellasite, Y3Cu9(OH)19Cl8, under scrutiny here, the spin (magnon) density of states (SDOS) can be accessed over the entire Brillouin zone through three-center magnon excitations. This mechanism is aided by the three different magnetic sublattices and strong short-range correlations in the distorted kagome lattice. The results of THz time-domain experiments agree remarkably well with linear spin-wave theory (LSWT). Relaxing the conventional zone-center constraint of photons gives a new aspect to probe magnetism in matter.

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Permalink: https://www.hzdr.de/publications/Publ-34543
Publ.-Id: 34543


Commensurate helicoidal order in the triangular layered magnet Na2MnTeO6

Kurbakov, A. I.; Susloparova, A. E.; Pomjakushin, V. Y.; Skourski, Y.; Vavilova, E. L.; Vasilchikova, T. M.; Raganyan, G. V.; Vasiliev, A. N.

The trigonal layered quaternary tellurate Na2MnTeO6 has been studied by means of various techniques to clarify its magnetic properties. The crystal structure of this compound is based on the triangular arrangement of all cations in the parallel layers with the space group P31c. By using symmetry analysis of the magnetic neutron scattering data, we have found that the solution for the magnetic structure corresponds to the magnetic Shubnikov group R3´c´ (No. 167.4.1337). Mn4+ ions in an octahedral environment form a triangular network where all spins are directed from the center of each triangle. Overall magnetic structure in Na2MnTeO6 is commensurate 120° spin helix with propagation vector k = (1/3, 1/3, 1/3) in variance with planar spin structure in structurally equivalent Li2MnTeO6 with magnetic propagation vector k = (1/3, 1/3, 0). The magnetization measurements show that Na2MnTeO6 experiences an antiferromagnetic order at TN = 5.5 K. NMR, electron spin resonance, and thermodynamics experiments demonstrate the extended temperature region of 2D short-range correlations well above the ordering temperature.

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Permalink: https://www.hzdr.de/publications/Publ-34542
Publ.-Id: 34542


Alteration of Mitochondrial Integrity as Upstream Event in the Pathophysiology of SOD1-ALS

Günther, R.; Pal, A.; Williams, C.; Zimyanin, V. L.; Liehr, M.; von Neubeck, C.; Krause, M.; Parab, M. G.; Petri, S.; Kalmbach, N.; Marklund, S. L.; Sterneckert, J.; Munch Andersen, P.; Wegner, F.; Gilthorpe, J. D.; Hermann, A.

Little is known about the early pathogenic events by which mutant superoxide dismutase 1 (SOD1) causes amyotrophic lateral sclerosis (ALS). This lack of mechanistic understanding is a major barrier to the development and evaluation of efficient therapies. Although protein aggregation is known to be involved, it is not understood how mutant SOD1 causes degeneration of motoneurons (MNs). Previous research has relied heavily on the overexpression of mutant SOD1, but the clinical relevance of SOD1 overexpression models remains questionable. We used a human induced pluripotent stem cell (iPSC) model of spinal MNs and three different endogenous ALS-associated SOD1 mutations (D90Ahom, R115Ghet or A4Vhet) to investigate early cellular disturbances in MNs. Although enhanced misfolding and aggregation of SOD1 was induced by proteasome inhibition, Cells 2022, it was not affected by activation of the stress granule pathway. Interestingly, we identified loss of mitochondrial, but not lysosomal, integrity as the earliest common pathological phenotype, which preceded elevated levels of insoluble, aggregated SOD1. A super-elongated mitochondrial morphology with impaired inner mitochondrial membrane potential was a unifying feature in mutant SOD1 iPSC-derived MNs. Impaired mitochondrial integrity was most prominent in mutant D90Ahom MNs, whereas both soluble disordered and detergent-resistant misfolded SOD1 was more prominent in R115Ghet and A4Vhet mutant lines. Taking advantage of patient-specific models of SOD1-ALS in vitro, our data suggest that mitochondrial dysfunction is one of the first crucial steps in the pathogenic cascade that leads to SOD1-ALS and also highlights the need for individualized medical approaches for SOD1-ALS.

Permalink: https://www.hzdr.de/publications/Publ-34541
Publ.-Id: 34541


Hot Hydride Superconductivity Above 550 K

Grockowiak, A. D.; Ahart, M.; Helm, T.; Coniglio, W. A.; Kumar, R.; Glazyrin, K.; Garbarino, G.; Meng, Y.; Oliff, M.; Williams, V.; Ashcroft, N. W.; Hemley, R. J.; Somayazulu, M.; Tozer, S. W.

The search for room temperature superconductivity has accelerated in the last few years driven by experimentally accessible theoretical predictions that indicated alloying dense hydrogen with other elements could produce conventional superconductivity at high temperatures and pressures. These predictions helped inform the synthesis of simple binary hydrides that culminated in the discovery of the superhydride LaH10 with a superconducting transition temperature Tc of 260 K at 180 GPa. We have now successfully synthesized a metallic La-based superhydride with an initial Tc of 294 K. When subjected to subsequent thermal excursions that promoted a chemical reaction to a higher order system, the Tc onset was driven irreversibly to 556 K. X-ray characterization confirmed the formation of a distorted LaH10 based backbone that suggests the formation of ternary or quaternary compounds with substitution at the La and/or H sites. The results provide evidence for hot superconductivity, aligning with recent predictions for higher order hydrides under pressure.

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Permalink: https://www.hzdr.de/publications/Publ-34540
Publ.-Id: 34540


Data to "Application of a fluorescence anisotropy-based assay to quantify transglutaminase 2 activity in cell lysates"

Hauser, S.; Sommerfeld, P.; Wodtke, J.; Hauser, C.; Schlitterlau, P.; Pietzsch, J.; Löser, R.; Pietsch, M.; Wodtke, R.

Primärdaten zum FA-Assay, activity-based ELISA und ELISA

Keywords: activity-based protein profiling; cancer; ELISA; enzyme assay; transamidase activity

Related publications

  • Reseach data in the HZDR data repository RODARE
    Publication date: 2022-04-13
    DOI: 10.14278/rodare.1537

Downloads:

Permalink: https://www.hzdr.de/publications/Publ-34539
Publ.-Id: 34539


Data Publication: Tuning of Curie temperature in Mn5Ge3 films

Xie, Y.; Birowska, M.; Funk, S. H.; Fischer, A. I.; Schwarz, D.; Schulze, J.; Zeng, Y.-J.; Helm, M.; Zhou, S.; Prucnal, S.

This contains a set of data that were used to generate the figures and results in the manuscripts: Tuning of Curie temperature in Mn5Ge3 films (DOI: 10.1063/5.0066717).

The compressed folders “Curie temperature in Mn5Ge3 films ” contain below data:

  • RBS data
  • MH data
  • ZFC/FC data
  • XRD data

Related publications

  • Reseach data in the HZDR data repository RODARE
    Publication date: 2022-04-13
    DOI: 10.14278/rodare.1535

Downloads:

Permalink: https://www.hzdr.de/publications/Publ-34538
Publ.-Id: 34538


The European Particle Therapy Network (EPTN) consensus on the follow-up of adult patients with brain and skull base tumours treated with photon or proton irradiation

de Roeck, L.; van der Weide, H.; Eekers, D.; Kramer, M.; Alapetite, C.; Bromstrand, M.; Burnet, N.; Calugaru, V.; Coremans, I.; Di Perri, D.; Harrabi, S.; Innalfi, A.; Klaver, Y.; Langendijk, J.; Méndez Romero, A.; Paulsen, F.; Roelofs, E.; de Ruysscher, D.; Timmermann, B.; Vitek, P.; Weber, D.; Whitfield, G.; Witt Nyström, P.; Zindler, J.; Troost, E. G. C.; Lambrecht, M.

Purpose: Treatment-related toxicity after irradiation of brain tumours has been underreported in the lit-
erature. Furthermore, there is considerable heterogeneity on how and when toxicity is evaluated. The aim
of this European Particle Network (EPTN) collaborative project is to develop recommendations for uni-
form follow-up and toxicity scoring of adult brain tumour patients treated with radiotherapy.
Methods: A Delphi method-based consensus was reached among 24 international radiation-oncology
experts in the field of neuro-oncology concerning the toxicity endpoints, evaluation methods and time
points.
Results: In this paper, we present a basic framework for consistent toxicity scoring and follow-up, using
multiple levels of recommendation. Level I includes all recommendations that are considered minimum
of care, whereas level II and III are optional evaluations in the advanced clinical or research setting,
respectively. Per outcome domain, the clinical endpoints and evaluation methods per level are listed.
Where relevant, the organ at risk threshold doses for recommended referral to specific organ specialists
are defined.

Keywords: European Particle Therapy Network; Particle therapy; Follow-up; Toxicity; Brain tumour; Skull base tumour; Central nervous system

Permalink: https://www.hzdr.de/publications/Publ-34532
Publ.-Id: 34532


Subjective memory impairment in glioma patients with curative radiotherapy

Donix, M.; Seidlitz, A.; Buthut, M.; Löck, S.; Meissner, G.; Matthes, C.; Troost, E. G. C.; Baumann, M.; Raschke, F.; Linn, J.; Krause, M.

Background: Radiotherapy in patients with primary brain tumors may affect hippocampal structure and
cause dyscognitive side-effects.
Patients and methods: Using structural MRI and comprehensive neurocognitive evaluation, we investi-
gated associations between hippocampal structure and memory deficits in 15 patients with WHO grade
3 and grade 4 gliomas receiving standard radio(chemo)therapy.
Results: We did not find changes in hippocampal thickness or cognitive abilities three months after com-
pleting radiotherapy. However, subjective memory impairment was associated with symptoms of
depression, but not with objective memory performance, cortical thickness of the hippocampus or radi-
ation dose.
Conclusions: Irrespective of whether there is a bidirectional relationship between affective changes and
subjective cognitive dysfunction in these patients, depressive symptoms remain a target for intervention
to improve their quality of life. The results of our pilot study highlight that future assessment of side
effects of radiotherapy concerning memory should include assessments of depressive symptoms.

Keywords: radiotherapy; hippocampus; MRI; neurocognitive evaluation; subjective memory impairment

Permalink: https://www.hzdr.de/publications/Publ-34531
Publ.-Id: 34531


Development and functional characterization of a versatile radio-/immunotheranostic tool for prostate cancer management

Arndt, C.; Bergmann, R.; Striese, F.; Merkel, K.; Máthé, D.; Rodrigues Loureiro, L. R.; Mitwasi, N.; Kegler, A.; Fasslrinner, F.; González Soto, K. E.; Neuber, C.; Berndt, N.; Kovács, N.; Szöllősi, D.; Hegedűs, N.; Tóth, G.; Emmermann, J.-P.; Harikumar, K. B.; Kovacs, T.; Bachmann, M.; Feldmann, A.

Due to its overexpression on the surface of prostate cancer (PCa) cells, the prostate stem cell antigen (PSCA) is a potential target for PCa diagnosis and therapy. Here we describe the development and functional characterization of a novel IgG4-based anti-PSCA antibody (Ab) derivative (anti-PSCA IgG4-TM) that is conjugated with the chelator DOTAGA. The anti-PSCA IgG4-TM represents a multimodal immunotheranostic compound that can be used (i) as target module (TM) for UniCAR T cell-based immunotherapy, (ii) for diagnostic PET imaging, and (iii) targeted alpha therapy. Cross-linkage of UniCAR T cells and PSCA-positive tumor cells via the anti-PSCA IgG4-TM results in efficient tumor cell lysis both in vitro and in vivo. After radiolabeling with 64Cu2+ the anti-PSCA IgG4-TM was successfully applied for high contrast PET imaging. In a PCa mouse model, it showed specific accumulation in PSCA-expressing tumors, while no uptake in other organs was observed. Additionally, the DOTAGA-conjugated anti-PSCA IgG4-TM was radiolabeled with 225Ac3+ and applied for targeted alpha therapy. A single injection of the 225Ac-labeled anti-PSCA IgG4-TM was able to significantly control tumor growth in experimental mice. Overall, the novel anti-PSCA IgG4-TM represents an attractive first member of a novel group of radio-/immunotheranostics that allows diagnostic imaging, endoradiotherapy, and CAR T cell immunotherapy.

Keywords: prostate cancer; PSCA; PSMA; IgG4; CAR T cell; theranostics; Ac-225; Cu-64; (18)F-JK-PSMA-7

Permalink: https://www.hzdr.de/publications/Publ-34530
Publ.-Id: 34530


Mu2e-II: Muon to electron conversion with PIP-II Contributed paper for Snowmass

Byrum, K.; Corrodi, S.; Oksuzian, Y.; Winter, P.; Xia, L.; Edmonds, A. W. J.; Miller, J. P.; Mott, J.; Marciano, W. J.; Szafron, R.; Bonventre, R.; Brown, D. N.; Kolomensky, Y. G.; Ning, O.; Singh, V.; Prebys, E.; Borrel, L.; Echenard, B.; Hitlin, D. G.; Hu, C.; Lin, D. X.; Middleton, S.; Porter, F. C.; Zhang, L.; Zhu, R.-Y.; Ambrose, D.; Badgley, K.; Bernstein, R. H.; Boi, S.; Casey, B. C. K.; Culbertson, R.; Gaponenko, A.; Glass, H. D.; Glenzinski, D.; Goodenough, L.; Hocker, A.; Kargiantoulakis, M.; Kashikhin, V.; Kiburg, B.; Kutschke, R. K.; Murat, P. A.; Neuffer, D.; Pronskikh, V. S.; Pushka, D.; Rakness, G.; Strauss, T.; Yucel, M.; Bloise, C.; Diociaiuti, E.; Giovannella, S.; Happacher, F.; Miscetti, S.; Sarra, I.; Martini, M.; Ferrari, A.; Müller, S.; Rachamin, R.; Barlas-Yucel, E.; Artikov, A.; Atanov, N.; Davydov, Y. I.; Glagolev, V.; Vasilyev, I. I.; Brown, D. N.; Uesaka, Y.; Denisov, S. P.; Evdokimov, V.; Kozelov, A. V.; Popov, A. V.; Vasilyev, I. A.; Tassielli, G.; Teubner, T.; Chislett, R. T.; Hesketh, G. G.; Lancaster, M.; Campbell, M.; Ciampa, K.; Heller, K.; Messerly, B.; Cummings, M. A. C.; Calibbi, L.; Blazey, G. C.; Syphers, M. J.; Zutshi, V.; Kampa, C.; Mackenzie, M.; Di Falco, S.; Donati, S.; Gioiosa, A.; Giusti, V.; Morescalchi, L.; Pasciuto, D.; Pedreschi, E.; Spinella, F.; Hedges, M. T.; Jones, M.; You, Z. Y.; Zanetti, A. M.; Valetov, E. V.; Dukes, E. C.; Ehrlich, R.; Group, R. C.; Heeck, J.; Hung, P. Q.; Demers, S. M.; Pezzullo, G.; Lynch, K. R.; Popp, J. L.

An observation of Charged Lepton Flavor Violation (CLFV) would be unambiguous evidence for
physics beyond the Standard Model. The Mu2e and COMET experiments, under construction, are
designed to push the sensitivity to CLFV in the μ → e conversion process to unprecedented levels.
Whether conversion is observed or not, there is a strong case to be made for further improving
sensitivity, or for examining the process on additional target materials. Mu2e-II is a proposed
upgrade to Mu2e, with at least an additional order of magnitude in sensitivity to the conversion
rate over Mu2e. The approach and challenges for this proposal are summarized. Mu2e-II may be
regarded as the next logical step in a continued high-intensity muon program at FNAL

Keywords: CLFV; MU2E; FNAL; Snowmass

Permalink: https://www.hzdr.de/publications/Publ-34527
Publ.-Id: 34527


Data publication: Epitaxial lateral overgrowth of tin spheres driven and directly observed by helium ion microscopy

Klingner, N.; Heinig, K.-H.; Tucholski, D.; Möller, W.; Hübner, R.; Bischoff, L.; Hlawacek, G.; Facsko, S.

Raw data for the publication: "Epitaxial lateral overgrowth of tin spheres driven and directly observed by helium ion microscopy". It contains helium ion microscopy, transmission electron microscopy, scanning electron microscopy as well as gallium focused ion microscopy images and XPS data. It shows how the irradiation of tin spheres with keV He ions causes epitaxial lateral overgrowth.

Keywords: helium ion microscope; tin whisker growth; defect kinetics

  • Reseach data in the HZDR data repository RODARE
    Publication date: 2022-04-14
    DOI: 10.14278/rodare.1539
    License: CC-BY-4.0

Downloads:

Permalink: https://www.hzdr.de/publications/Publ-34526
Publ.-Id: 34526


Biogeographic Regionalization: Freshwater

Dias, M. S.; Oikonomou, A.; Su, G.

Defining the number and geographical borders of regions containing similar organisms and high levels of endemism can shed light on the evolution and distribution of life on Earth. We provide an historical overview of studies delineating the global biogeographical regions of freshwater organisms, mainly focusing on fish, to understand whether aquatic and terrestrial organisms share similar distribution patterns. Then, we provide a geographical and biological description giving special attention to major biogeographical fish patterns and taxa present in each of the considered regions.

Permalink: https://www.hzdr.de/publications/Publ-34522
Publ.-Id: 34522


Influence of surface roughness on the sorption of Cm(III) on crystalline-water interfaces

Demnitz, M.; Schymura, S.; Neumann, J.; Müller, K.; Schmidt, M.

Many countries plan to use deep geological repositories to dispose of their highly radioactive nuclear waste. Internationally, crystalline rock is a potential host rock because of its strong geotechnical stability, low permeability and low solubility. After a potential water ingress into a nuclear waste repository, radionuclides might be mobilized in aqueous solution. The topographical surface features affect the speciation and therefore retention potential of radionuclides on the host rock. Therefore, there is a need for using sophisticated techniques that allow to characterize the nanostructure of such crystalline rock with spatial resolution and the molecular speciation of the actinides thereon. As a representative for trivalent actinides, such as Am(III), Np(III), and Pu(III), we have chosen the actinide Cm(III). It possesses excellent luminescence properties, allowing us to determine Cm(III) sorption uptake and molecular speciation.

Our investigations focused on cleaved orthoclase (K-feldspar) single crystals and thin slices of different crystalline rocks stemming from the Grimsel test site (GTS) in Switzerland. Cleaved pieces of orthoclase or thin sections of the crystalline rocks were immersed in a sorption solution containing Cm(III). The experiments were undertaken at selected pH values (5.5, 6.9 and 7.3) and different inherent mineralogical complexity of the systems. Subsequently, we applied correlated spectroscopy to analyze the samples. Thus, we were able to correlate mineralogy, topography, and grain boundary effects with radionuclide speciation, allowing us to identify important radionuclide retention processes and parameters. [1, 2].

We observed that Cm(III) sorption uptake and speciation on orthoclase single crystals depends not exclusively on the mineral phase and the solution conditions, such as the pH, but also on the surface roughness. At pH 5.5 the sorption uptake differed between low and high surface roughness areas, while the speciation on both areas remained largely similar. Increasing the pH to 6.9 not only increased the overall sorption uptake, also the speciation between smoother and rougher surfaces differed. Using luminescence peak and lifetime analysis we could determine that the speciation is highly dependent on the availability on strong sorption sites. Based on our results we proposed a simple model for Cm(III) sorption on an orthoclase surface.

Further we compared the Cm(III) speciation on orthoclase singe crystals with orthoclase mineral grains on a thin section prepared from Grimsel specimen rock. The sorption was now influenced additionally by the presence of a heterogeneous surface, affecting the strength and form of surface sorbed Cm(III) species.

We conclude that in addition to mineral composition, surface roughness needs to be considered adequately by reactive transport models to describe interfacial speciation of contaminants and respective retention patterns for the safety assessments of nuclear waste repositories.

Acknowledgements:

This work has been developed in the frame of the iCross project. We gratefully acknowledge funding provided by the German Federal Ministry of Education and Research (BMBF, Grant 02NUK053) and the Helmholtz Association (Grant SO-093).

[1] Molodtsov et al. (2019): Sorption of Eu(III) on Eibenstock granite studied by µTRLFS: A novel spatially-resolved luminescence-spectroscopic technique – In: Scientific Reports, 9, Article Number 6287.

[2] Demnitz et al. (2021): Effects of surface roughness and mineralogy on the sorption of Cm(III) on crystalline rock– In: Journal of Hazardous Materials, Volume 423, Part A , 127006.

Keywords: luminescence; speciation; Cm; crystal; interface; crystalline; roughness; topography; microscopy; spatial

  • Open Access Logo Lecture (Conference) (Online presentation)
    28. Tagung der Fachsektion Hydrogeologie e. V. in der DGGV e.V., 23.-25.03.2022, Jena, Germany

Permalink: https://www.hzdr.de/publications/Publ-34518
Publ.-Id: 34518


Spatially resolved sorption of Cm(III) on crystalline rock: influence of surface roughness and mineralogy

Demnitz, M.; Molodtsov, K.; Schymura, S.; Schierz, A.; Müller, K.; Schmidt, M.

Many countries will use deep geological repositories to dispose of highly active nuclear waste. Crystalline rock is a potential host rock because of its strong geotechnical stability, low permeability and low solubility; however, its inherent mineralogy is heterogeneous, consisting of a wide set of minerals in varying amounts. Therefore, there is a need for using sophisticated techniques that allow spatial resolution to characterize the nanostructure of such crystalline rock surfaces and the speciation of the actinides therein. As a representative for trivalent actinides, such as Am(III), Np(III), and Pu(III), which are expected to be present due to the reducing conditions encountered in a deep geological repository, we have chosen the actinide Cm(III). Cm(III) possesses excellent luminescence properties, which allows us to not only examine the sorption uptake but also the speciation of Cm(III) on the surface.

We combined spatially resolved investigation techniques, such as vertical scanning interferometry, calibrated autoradiography, and Raman microscopy coupled to micro-focus time-resolved laser-induced luminescence spectroscopy (µTRLFS) (Molodtsov et al., 2019). Thus, we were able to correlate mineralogy, surface roughness, and grain boundary effects with radionuclide speciation, allowing us to identify important radionuclide retention processes and parameters.

Investigations focused on granite from Eibenstock (Germany) and migmatised gneiss from Bukov (Czech Republic). Cm(III) sorption on the rock's constituting minerals – primarily feldspar, mica and quartz – was analyzed quantitatively and qualitatively. We observed that Cm(III) sorption uptake and speciation depends not only on the mineral phase but also the surface roughness (Demnitz et al., 2021). An increasing surface roughness leads to higher sorption uptake and a stronger coordination of the sorbed Cm(III). On the same mineral grains sorption differed significantly depending if an area exhibits a low or high surface roughness. In the case that one mineral phase dominates the sorption process, sorption of Cm(III) on other mineral phases will only occur at strong binding sites, typically where surface roughness is high. Areas of feldspar and quartz with high surface roughness additionally showed the formation of sorption species with particularly high sorption strength that could either be interpreted as Cm(III) incorporation species or ternary complexes on the mineral surface (Demnitz et al., 2021).

We conclude that in addition to mineral composition, surface roughness needs to be adequately considered to describe interfacial speciation of contaminants and respective retention patterns for the safety assessments of nuclear waste repositories.

Demnitz, M., Molodtsov, K., Schymura, S., Schierz, A., Müller, K., Jankovsky, F., Havlova, V., Stumpf, T., and Schmidt, M.: Effects of surface roughness and mineralogy on the sorption of Cm(III) on crystalline rock, J. Hazard. Mater. Pt. A, 423, 127006, https://doi.org/10.1016/j.jhazmat.2021.127006, 2021.  

Molodtsov, K., Schymura, S., Rothe, J., Dardenne, K., and Schmidt, M.: Sorption of Eu(III) on Eibenstock granite studied by µTRLFS: A novel spatially-resolved luminescence-spectroscopic technique, Sci. Rep.-UK, 9, 6287, https://doi.org/10.1038/s41598-019-42664-2, 2019. 

Keywords: luminescence; speciation; Cm; host rock; interface; crystalline; roughness; topography; microscopy; spatial

  • Open Access Logo Lecture (Conference)
    Interdisciplinary research symposium On the safety of nuclear disposal practices 2021, 10.-12.11.2021, Berlin, Germany
    DOI: 10.5194/sand-1-145-2021

Permalink: https://www.hzdr.de/publications/Publ-34517
Publ.-Id: 34517


Influence of surface roughness on the sorption of Cm(III)

Demnitz, M.; Schymura, S.; Neumann, J.; Müller, K.; Schmidt, M.

INTRODUCTION

Many countries will use deep geological repositories to dispose of their highly radioactive nuclear waste. With an international perspective, crystalline rock is a potential host rock because of its strong geotechnical stability, low permeability and low solubility. However, its inherent mineralogy is heterogeneous, consisting of a wide set of minerals in varying amounts. Therefore, there is a need for using sophisticated techniques that allow to characterize the nanostructure of such crystalline rock surfaces with spatial resolution and the molecular speciation of the actinides thereon. As a representative for trivalent actinides, such as Am(III), Np(III), and Pu(III), which are expected to be present due to the reducing conditions encountered in a deep geological repository, we have chosen the actinide Cm(III). It possesses excellent luminescence properties, allowing us to determine sorption uptake and molecular speciation of Cm(III) on the surface.

DESCRIPTION OF THE WORK

Investigations focused on cleaved orthoclase (K-feldspar) single crystals as well as different crystalline rocks stemming from various regions in Europe. Cleaved pieces of orthoclase or thin sections of the crystalline rocks were immersed in a sorption solution containing [Cm(III)] = 5∙10-7 – 10-5 M. The experiments were undertaken at selected pH values (5.0 and 6.9) and different inherent mineralogical complexity of the systems. Subsequently, we applied correlated spectroscopy to analyze the samples. We combined vertical scanning interferometry, calibrated autoradiography, and Raman microscopy coupled to µTRLFS. Thus, we were able to correlate mineralogy, topography, and grain boundary effects with radionuclide speciation, allowing us to identify important radionuclide retention processes and parameters. For experimental details, see [1].

RESULTS AND DISCUSSION

We observed that Cm(III) sorption uptake and speciation depends not only on the mineral phase, but also the surface roughness. Already on single crystal orthoclase an increasing surface roughness leads to higher sorption uptake (see Fig. 1) and to a stronger coordination of the sorbed Cm(III).
Increasing the mineral complexity of the system further, we used thin sections of various crystalline rocks, consisting mainly of feldspar, quartz, and mica. We observed significant differences in sorption uptake on individual mineral phases as well as the resulting speciation. In case that one mineral phase dominates the sorption process, e.g. amphibole, sorption of Cm(III) on other mineral phases will only occur at strong binding sites, typically where surface roughness is high. Areas of feldspar and quartz with high surface roughness additionally showed the formation of sorption species with particularly high sorption strength that could either be interpreted as Cm(III) incorporation species or adsorbed ternary complexes on the mineral surface.[2]
At pH values of around 6.8 Cm(III) generally sorbs more weakly to the surface, while preferentially targeting mineral phases such as mica instead of feldspar or quartz. At a higher pH of 8.0 the sorption uptake on other mineral phases increases, with a general trend towards more strongly bound Cm(III) surface species.
We conclude that in addition to mineral composition, surface roughness needs to be considered adequately by reactive transport models to describe interfacial speciation of contaminants and respective retention patterns for the safety assessments of nuclear waste repositories.

Acknowledgements:
This work has been developed in the frame of the iCross project. We gratefully acknowledge funding provided by the German Federal Ministry of Education and Research (BMBF, Grant 02NUK053) and the Helmholtz Association (Grant SO-093).

REFERENCES

1. Molodtsov et al., “Sorption of Eu(III) on Eibenstock granite studied by µTRLFS: A novel spatially-resolved luminescence-spectroscopic technique” Scientific Reports, 9, Article Number 6287 (2019), https://doi.org/10.1038/s41598-019-42664-2.

2. Demnitz et al., “Effects of surface roughness and mineralogy on the sorption of Cm(III) on crystalline rock” Journal of Hazardous Materials, (2021), https://doi.org/10.1016/j.jhazmat.2021.127006.

Keywords: luminescence; speciation; Cm; crystal; interface; crystalline; roughness; topography; microscopy; spatial

  • Poster (Online presentation)
    TransRet2020 - Workshop on Processes Influencing Radionuclide Transport and Retention, 12.04.-13.10.2021, Karlsruhe, Germany

Permalink: https://www.hzdr.de/publications/Publ-34516
Publ.-Id: 34516


Machine Learning Collaboration-as-a-service at Helmholtz

Steinbach, P.; Hoffmann, H.; Tanveer, M.; Schmerler, S.; Starke, S.

Machine Learning (ML) based methods are proliferating in industry, society, science and physics in particular in the last years. Not only do ML tools allow inferences from experimental data, but also have shown to be an inroads to previously unreachable theoretical or experimental domains. In this presentation, I'll introduce Helmholtz AI as a funded networking activity within Helmholtz to support matter research in using ML for science. I'll dive into how and why the program is split into research and collaboration-as-a-service staff. If time allows, I'll discuss how we approach ML projects with scientists from a consulting point of view.

Keywords: machine learning; consulting; academia; science; services; Helmholtz AI

  • Open Access Logo Invited lecture (Conferences) (Online presentation)
    Seminar des ORIGINS Data Science Laboratory Munich, Einladung durch Lukas Heinrich, 08.04.2022, virtuell, Germany
    DOI: 10.6084/m9.figshare.19550815.v1

Permalink: https://www.hzdr.de/publications/Publ-34512
Publ.-Id: 34512


Effects of electrically conductive walls on turbulent magnetohydrodynamic flow in a continuous casting mold

Blishchik, A.; Glavinic, I.; Wondrak, T.; van Odyck, D.; Kenjereš, S.

In the present study, we have performed a series of numerical simulations of the turbulent liquid metal flow in a laboratory-scale setup of the continuous casting. The liquid metal flow was subjected to an external non-uniform magnetic field reproducing a realistic electromagnetic brake (EMBr) effect. The focus of this research was on the effects of the finite electrical conductivity of Hartmann walls on the flow and turbulence in the mold. To be able to simulate distributions of the electric potential and current in both the fluid and solid wall domains, we applied our recently developed and validated in-house conjugate MHD solver based on the open-source code OpenFOAM. The dynamic Large Eddy Simulation (LES) method was used to simulate the turbulent flow. The results obtained for the neutral (non-MHD) and MHD cases over a range of the imposed EMBr strengths – all for the perfectly electrically insulated walls – were compared with the available Ultrasound Doppler Velocimetry (UDV) measurements. A good agreement between simulations and experiments was obtained for all simulated cases. Next, we completed a series of simulations including a wide range of the finite electric conductivities (ranging from a weakly to perfectly conducting wall conditions) of the Hartmann walls for a fixed value of the imposed EMBr. The obtained results demonstrated a significant influence of the electric wall conductivities on the flow and turbulence reorganization. It is expected that here provided insights can be applicable for the new generation of the laboratory- and real-scale continuous casting setups.

Keywords: MHD; Magnetic field; Lorentz force; OpenFOAM; Electrically conducting walls; Dynamic LES; Continuous casting

Permalink: https://www.hzdr.de/publications/Publ-34511
Publ.-Id: 34511


Spatially-resolved sorption of Cm(III)/Eu(III) on heterogeneous crystalline rocks

Molodtsov, K.; Schymura, S.; Schierz, A.; Müller, K.; Stumpf, T.; Schmidt, M.

Many countries will use deep geological repositories (DGR) to store their heat generating high-level radioactive waste. Crystalline rock is one of the potential host rocks, but possesses high inherent mineralogical heterogeneity. Since the molecular retardation reactions of radionuclides at water-mineral interfaces depend mainly on the availability of reactive sites, heterogeneity is expected to play a major role for contaminant transport in a DGR. The fundamental understanding and transferrability of this heterogeneity into modeling different transport scenarios is of urgent need for a reliable safety assessment of a repository. Through correlation of spectroscopic information with spatial resolution we characterized the nanostructure of crystalline rock surfaces and the surface speciation of selected radionuclides, namely Eu(III) and Cm(III) thereon. We utilized vertical scanning interferometry, autoradiography, and Raman microscopy in combination with µTRLFS – microfocus time-resolved laser-induced fluorescence spectrsocopy.[1] Using these novel techniques the surface speciation of Eu(III) and Cm(III) can be qualified and quantified. Moreover, we were able to correlate mineralogy, topography, and grain boundary effects with radionuclide speciation, allowing us to draw conclusions about radionuclide retention mechanisms on mineral surfaces.
Our work focussed on granite from Eibenstock (Germany) and migmatised gneiss from the Bukov URL (Czech Republic). We characterized the sorption of Cm(III) and Eu(III) on feldspar, mica, quartz and accessory mineral areas on both rocks. [1-3] Using autoradiography and µTRLFS we linked the sorption uptake on the heterogeneous surface with the mineralogy and the surface roughness, showing that surface roughness within the same mineral phase has an impact not only on the amount of sorption uptake, but also the radionuclide surface speciation and thus bond strengths and reversibility.
Using µTRLFS we identified how the speciation correlates to mineral phases and surface roughness. A higher surface roughness induces more binding sites available to Eu(III) and Cm(III) resulting in strongly bound trivalent radionuclide surface complexes and a higher sorption uptake. On quartz and feldspar high surface roughness leads to ternary Cm(III) complex formation on the surface presumably with silicate and carbonate ions avaliable in solution.
In comparison to Eibenstock granite, Bukov gneiss inherently contained a greater number of accessory minerals. We observed that some of them seem to dominate the sorption process, lowering the sorption of Eu(III) on the major components feldspar and quartz in comparison to Eibenstock granite.[2] The leftover Cm(III)/Eu(III) sorb on stronger and preferential sorption sites, which are located in regions exhibiting a high surface roughness.[3] This could be clearly proven for Cm(III)/Eu(III) surface complexes being stronger on feldspar. With this work we demonstrated a successful upscaling approach to derive molecular understanding of radionuclide retention processes from the nm to the cm sacle.

References
[1] Molodtsov, Sorption of Eu(III) on Eibenstock granite studied by µTRLFS: A novel spatially-resolved luminescence-spectroscopic technique, Scientific Reports, 9, 6287 (2019).
[2] Molodtsov, A µTRLFS investigation on the sorption of Eu3+ on Bukov migmatised gneiss on the molecular level, Environmental Science & Technology, submitted.
[3] Demnitz, A spatially-resolved study on the sorption of Cm(III) on different crystalline rocks using surface investigation techniques, in preparation.

Keywords: luminescence; trlfs; surface; mineralogy; topography; interface; curium; europium; correlative; spectroscopy

  • Open Access Logo Lecture (Conference) (Online presentation)
    2. Tage der Standortauswahl, 11.-12.02.2021, Freiberg, Germany

Permalink: https://www.hzdr.de/publications/Publ-34509
Publ.-Id: 34509


Contemporary environment and historical legacy explain functional diversity of freshwater fishes in the world rivers

Su, G.; Tedesco, P. A.; Toussaint, A.; Villéger, S.; Brosse, S.

Aim
Regional taxonomic diversity (species richness) is strongly influenced by a joint effect of the current processes (habitat and energy availability) and historical legacies (past climate and geography), but it is still unclear how those historical and current environmental drivers have shaped the functional diversity of species assemblages.

Major taxa studied
Freshwater fish.

Location
Global.

Time period
1960s–2000s.

Methods
We combined the spatial occurrences over 2,400 river basins world-wide and the functional traits measured on 10,682 freshwater fish species to quantify the relative role of the habitat, climate and historical processes on the current global fish functional diversity. To avoid any correlation between taxonomic diversity and functional diversity, we controlled for differences in the number of species (species richness) between rivers. Functional diversity was considered through three complementary facets: functional richness, functional dispersion and functional identity.

Results
The habitat-related variables explained most of the gradient in functional richness, verifying the habitat size–diversity hypothesis. In contrast, the historical climate–geography legacies markedly imprinted the functional dispersion and functional identity patterns, leading to a balanced influence of the current and historical processes. Indeed, the distribution of morphological traits related to fish dispersal was explained largely by the glaciation events during the Quaternary, leading to strong latitudinal gradients.

Main conclusions
This study provides new insights into the role of historical and current environmental determinants on the functional structure of fish assemblages and strengthens the proposal that the independence of facets of functional diversity from the species richness makes them essential biodiversity variables to understand the structure of communities and their responses to global changes.

Related publications

  • Open Access Logo Global Ecology and Biogeography 31(2022)4, 700-713
    Online First (2022) DOI: 10.1111/geb.13455

Permalink: https://www.hzdr.de/publications/Publ-34508
Publ.-Id: 34508


FISHMORPH: A global database on morphological traits of freshwater fishes

Brosse, S.; Charpin, N.; Su, Guohuan; Toussaint, A.; Herrera-R, G. A.; Tedesco, P. A.; Villéger, S.

Motivation
Global freshwater fish biodiversity and the responses of fishes to global changes have been explored intensively using taxonomic data, whereas functional aspects remain understudied owing to the lack of knowledge for most species. To fill this gap, we compiled morphological traits related to locomotion and feeding for the world freshwater fish fauna based on pictures and scientific drawings available from the literature.

Main types of variables contained
The database includes 10 morphological traits measured on 8,342 freshwater fish species, covering 48.69% of the world freshwater fish fauna.

Spatial location and grain
Global.

Major taxa and level of measurement
The database considers ray-finned fishes (class Actinopterygii). Measurements were made at the species level.

Software format
.csv.

Main conclusion
The FISHMORPH database provides the most comprehensive database on fish morphological traits to date. It represents an essential source of information for ecologists and environmental managers seeking to consider morphological patterns of fish faunas throughout the globe, and for those interested in current and future impacts of human activities on the morphological structure of fish assemblages. Given the high threat status of freshwater environments and the biodiversity they host, we believe this database will be of great interest for future studies on freshwater ecology research and conservation.

Related publications

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  • Secondary publication expected from 17.09.2023

Permalink: https://www.hzdr.de/publications/Publ-34507
Publ.-Id: 34507


Spatially resolved sorption of Cm(III) on crystalline rock: influence of surface roughness and mineralogy

Demnitz, M.; Molodtsov, K.; Schymura, S.; Schierz, A.; Müller, K.; Schmidt, M.

Many countries will use deep geological repositories to dispose of their highly active nuclear waste. Crystalline rock is a potential host rock because of its high stability, heat resistance and low solubility. However, it possesses a high inherent mineralogical heterogeneity. Using sophisticated techniques that allow spatial resolution we characterized the nanostructure of such crystalline rock surfaces and the speciation of the actinide Cm(III) thereon.

Namely, we combined vertical scanning interferometry, calibrated autoradiography, and Raman microscopy coupled to µTRLFS (micro-focus time-resolved laser-induced spectroscopy).[1] Thus we were able to correlate mineralogy, topography, and grain boundary effects with radionuclide speciation, allowing us to identify important radionuclide retention processes and parameters.

Investigations focussed on granite from Eibenstock (Germany) and migmatised gneiss from Bukov (Czech Republic). Cm(III) sorption on the rock’s constituing minerals - primarily feldspar, mica and quartz - was analyzed quantitatively and qualitatively. We observed that Cm(III) sorption uptake and speciation depends not only on the mineral phase, but also the surface roughness. An increasing surface roughness leads to higher sorption uptake and a stronger coordination of the sorbed Cm(III). On the same mineral grains sorption differed significantly depending if an area exhibits a low or high surface roughness. In case that one mineral phase dominates the sorption process, sorption of Cm(III) on other mineral phases will only occur at strong binding sites, typically where surface roughness is high. Areas of feldspar and quartz with high surface roughness additionally showed the formation of sorption species with particularly high sorption strength that could either be interpreted as Cm(III) incorporation species or ternary complexes on the mineral surface.

We conclude that in addition to mineral composition, surface roughness needs to be considered adequately to describe interfacial speciation of contaminants and respective retention patterns for the safety assessments of nuclear waste repositories.

[1] Molodtsov, Schymura, Rothe, Dardenne & Schmidt (2019), Scientific Reports 9, 6287.

  • Open Access Logo Lecture (Conference) (Online presentation)
    Goldschmidt Virtual 2021, 08.07.2021, Lyon, France
    DOI: 10.7185/gold2021.3156

Permalink: https://www.hzdr.de/publications/Publ-34506
Publ.-Id: 34506


BIM - Biomedical Image analysis Models survey

Li, R.; Sharma, V.; Thangamani, S.; Yakimovich, A.

This is meta-analysis repository for the program code and meta-data collected on open-source biomedical image analysis models. This repository is maintained as a continuous survey of published open-source models. Code is aimed at obtaining statistical summary of the meta-data.

Keywords: open source; machine learning; bioimage analysis; deep learning

  • Software in external data repository
    Publication year 2022
    Programming language: Python
    System requirements: Python 3.9.7 seaborn 0.11.2 pandas 1.3.4 matplotlib 3.5.0
    License: MIT (Link to license text)
    Hosted on GitHub: Link to location

Permalink: https://www.hzdr.de/publications/Publ-34504
Publ.-Id: 34504


GUI Flow data

Döß, A.; Schubert, M.

- english version below -

Diese grafische Nutzeroberfläche in Form einer installirbaren standalone-Anwendung dient zur Visualisierung aus der Literatur bekannter experimenteller Datensätze und Strömungskarten für horizontal strömende Luft/Wasser-Systeme. Weiterhin sind Modelle und Strömungskarten aus der Literatur integriert, die für beliebige Stoffsysteme eine Vorhersage über die zu erwartenden Strömungsformen treffen. Zusätzlich erlauben Schnitstellen in Form von .txt-Dateien das Importieren eigener Datensätze, bzw. das Exportieren der visualisierten Inhalte.

Für die Richtigkeit der dargestellten Inhalte wird keine Haftung übernommen. Das Urheberrecht für die zugrundeliegenden Datensätze und Berechnungen liegt bei den Autoren der referenzierten Primärliteratur.

This graphical user interface in the form of an installable standalone application is used to visualize experimental data sets and flow maps known from the literature for horizontally flowing air/water systems. Furthermore, models and flow maps from the literature are integrated to predict the flow patterns for any fluid system. Additionally, data interfaces in the form of .txt files allow the import of own data sets, respectively the export of the visualized contents.

No liability is assumed for the correctness of the displayed contents. The copyright for the underlying data sets and calculations is held by the authors of the referenced primary literature.

Keywords: GUI; Interface; Flow data; flow regime maps; Strömungsdaten; Strömungskarten

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Permalink: https://www.hzdr.de/publications/Publ-34503
Publ.-Id: 34503


Sequencing meets machine learning to fight emerging pathogens: A preview

Yakimovich, A.

In searching for SARS-CoV variants-of-concern, pathogen sequencing is generating an impressive amount of data. However, beyond epidemiological use, these data contain cues fundamental to our understanding of pathogen evolution in the human population. Yet, to harness them, further development of computational methodology, such as machine learning, may be required. This preview discusses updates in machine learning to understand emerging pathogens.

Keywords: SARS-CoV2; machine learning; sequencing

Permalink: https://www.hzdr.de/publications/Publ-34497
Publ.-Id: 34497


A tandem segmentation-classification approach for the localization of morphological predictors of C. elegans lifespan and motility

Galimov, E.; Yakimovich, A.

C. elegans is an established model organism for studying genetic and drug effects on aging, many of which are conserved in humans. It is also an important model for basic research, and C. elegans pathologies is a new emerging field. Here we develop a proof-of-principal convolutional neural network-based platform to segment C. elegans and extract features that might be useful for lifespan prediction. We use a dataset of 734 worms tracked throughout their lifespan and classify worms into long-lived and short-lived. We designed WormNet - a convolutional neural network (CNN) to predict the worm lifespan class based on young adult images (day 1 – day 3 old adults) and showed that WormNet, as well as, InceptionV3 CNN can successfully classify lifespan. Based on U-Net architecture we develop HydraNet CNNs which allow segmenting worms accurately into anterior, mid-body and posterior parts. We combine HydraNet segmentation, WormNet prediction and the class activation map approach to determine the segments most important for lifespan classification. Such a tandem segmentation-classification approach shows the posterior part of the worm might be more important for classifying long-lived worms. Our approach can be useful for the acceleration of anti-aging drug discovery and for studying C. elegans pathologies.

Keywords: aging; deep learning; Caenorhabditis elegans; interpretable machine learning; convolutional neural networks

Related publications

Permalink: https://www.hzdr.de/publications/Publ-34496
Publ.-Id: 34496


Evaluation of raw data from THz source.

Gruber, T.

The radiation source ELBE (Electron Linac for beams with high Brilliance and low Emittance) at the Helmholtz Centre Dresden Rossendorf (HZDR) can produce several kinds of secondary radiations. THz radiation is one of them and can be used with a typical pulse frequency of 100 kHz as a stimulation source for elementary low-energy degrees of freedom in matter. It was used in the "Phase-resolved Higgs response in superconducting cuprates" publication (DOI: 10.1038/s41467-020-15613-1). The raw data for this publication can be accessed on RODARE (DOI: 10.14278/rodare.277) and will be used to reproduce the figures from the publication. This Jupyter notebook enables the user to handle the raw data from an TELBE THz experiment. To sample the whole THz wave the laser path length is modified by moving specific mirrors. The raw data contains for each mirror position a binary file storing the signal spectra and a folder with gray scaled tiff files storing the jitter timing. Parts of the code are parallelized and can run on multiple cores. The execution time on a single core is roughly 15 min after downloading and extracting a 20 GB zip file.

  • Software in the HZDR data repository RODARE
    Publication date: 2022-04-06
    DOI: 10.14278/rodare.1516
    License: MIT

Downloads:

Permalink: https://www.hzdr.de/publications/Publ-34492
Publ.-Id: 34492


Data publication: Caenorhabditis elegans microscopy dataset with lifespan, movement and segmentation annotations.

Galimov, E.; Pincus, Z.; Yakimovich, A.

The nematode Caenorhabditis elegans (C. elegans) is an established model for studying various interventions into the ageing process, which allowed to find numerous genes and drugs interfering with agein. This dataset of widefield time-lapse (days 1 to 3) micrographs of C. elegans was initially obtained in the Pincus lab (Pincus et al. 2011, Zhang et al. 2016). Here, the dataset was annotated for lifespan, movement and segmentation of C. elegans, and was employed for developing a machine learning framework (Yakimovich et al. 2021). All files are in 8-bit PNG format. Movement and lifespan annotations are provided using folder structure. Segmentation annotation is provided by the accompanying masks.

Keywords: C. elegans; Caenorhabditis elegans; lifespan; movement; segmentation; microscopy

Related publications

Permalink: https://www.hzdr.de/publications/Publ-34491
Publ.-Id: 34491


Review on zigzag air classifier

Kaas, A.; Mütze, T.; Peuker, U. A.

The zigzag (ZZ) classifier is a sorting and classification device with a wide range of applications (e.g. recycling, food industry [1, 2]). Due to the possible variation of geometry and process settings, the apparatus is used for various windows of operation regarding the specifications of the separation (e.g. cut sizes from 100 μm to several decimetres, compact and fluffy materials as well as foils). Since the ZZ-classifier gains more and more interest in recycling applications, it is discussed in this paper, regarding its design, mode of operation, influencing parameters and the research to date. Research on the ZZ-classifier has been going on for more than 50 years and can be divided into mainly experimental studies and modelling approaches.

Keywords: zigzag; classifier; separation; modelling; design

Permalink: https://www.hzdr.de/publications/Publ-34489
Publ.-Id: 34489


The RODARE Data Repository (InvenioRDM) and why we need a separate Metadata Catalogue

Knodel, O.

Presentations from the Workshop on Metadata Catalogues, which took place virtually via Zoom on the 4th April 2022. Rodare was presented to introduce a data publication repository in contrast to the metadata catalogues SciCAT and ICAT. A recording of the event can be found on the ExPaNDS website: https://expands.eu/presentations/

Keywords: Data Management; Metadata Catalogue; ExPaNDS

  • Open Access Logo Invited lecture (Conferences) (Online presentation)
    ExPaNDS Workshop on Metadata Catalogues, 04.04.2022, online, online

Downloads:

Permalink: https://www.hzdr.de/publications/Publ-34484
Publ.-Id: 34484


Novel Mixing Relations for Determining the Effective Thermal Conductivity of Open-Cell Foams

Nain Camacho Hernandez, J.; Link, G.; Schubert, M.; Hampel, U.

This paper proposes a new approach to relate the effective thermal conductivity of open-cell solid foams to their porosity. It is based on a recently published approach for estimating the dielectric permittivity of isotropic porous media. A comprehensive assessment was performed comparing the proposed mixing relation with published experimental data for thermal conductivity and with numerical data from state-of-the-art relations. The mixing relation for the estimation of thermal conductivities based on dodecahedrons as building blocks shows good agreement with experimental data over a wide range of porosity.

Keywords: open-cell foams; effective permittivity; thermal conductivity; platonic solids

Permalink: https://www.hzdr.de/publications/Publ-34483
Publ.-Id: 34483


Analysis of Low-Temperature Magnetotransport Properties of NbN Thin Films Grown by Atomic Layer Deposition

Vegesna, S. V.; Lanka, S. V.; Bürger, D.; Li, Z.; Linzen, S.; Schmidt, H.

Superconducting niobium nitride (NbN) films with nominal thicknesses of 4 nm, 5 nm, 7 nm, and 9 nm were grown on
sapphire substrates using atomic layer deposition (ALD). We observed probed Hall resistance (HR) (Rxy) in external out-ofplane magnetic fields up to 6 T and magnetore-sistance (MR) (Rxx) in external in-plane and out-of-plane magnetic fields up
to 6 T on NbN thin films in Van der Pauw geometry. We also observed that positive MR dominated. Our study focused on the
analysis of interaction and localisation effects on electronic disorder in NbN in the normal state in temperatures that ranged
from 50 K down to the superconducting transition temperature. By modelling the temperature and magnetic field
dependence of the MR data, we extracted the temperature-dependent Coulomb interaction constants, spin–orbit scattering
lengths, localisation lengths, and valley degeneracy factors. The MR model allowed us to distinguish between interaction
effects (positive MR) and localisation effects (negative MR) for in-plane and out-of-plane magnetic fields. We showed that
anisotropic dephasing scattering due to lattice non-idealities in NbN could be neglected in the ALD-grown NbN thin films.

Keywords: Atomic layer deposition; Coulomb interaction constant; Magnetoresistance; NbN thin films; Supercondutor; Valley degeneracy

Permalink: https://www.hzdr.de/publications/Publ-34481
Publ.-Id: 34481


Liquid Metal Alloy Ion Sources for FIB Applications in Nano – Technology

Bischoff, L.; Klingner, N.; Hlawacek, G.; Pablo Navarro, J.; Lenz, K.; Lindner, J.; Mazarov, P.; Pilz, W.; Meyer, F.

Focused Ion Beam (FIB) processing has been established as a well-suited and promising technique in R&D in nearly all fields of nanotechnology for patterning and prototyping on the μm-scale and below. Liquid Metal Alloy Ion Sources (LMAIS) represent an alternative to expand the FIB application fields beside all other source concepts. Here we present in the frame of two industrial related projects (ZIM) the development of different special LMAIS for FIB applications in nano–technology. So among others the alloys CoNd, CoNdB, AuGeB, AuGeBNi, AuSiCr, GaBiLi, CoDy, CuDy and AuSiDy are investigated and tested with regard to their use in modern mass separated FIB systems due to mass resolution, ion beam current of the certain ion species and the available spot size. The light ions like B, Li or Si dedicated for ion beam lithography systems. The transition metal elements Co, Fe and Ni are important for the modification and the adjustment of magnetic properties of nanomagnetic structures, presented in detail with a Co – FIB on a permalloy nanowire. Rare earth elements, especially Dy can tune the magnetic damping in nanometric dimensions. The latter is shown on magnonic stripe pattern of one mm² in size on a thin permalloy film made by a VELION FIB.

Keywords: Focused Ion Beam; Liquid Metal Alloy Ion Sources; nanomagnetic structures; magnetic damping

  • Lecture (Conference)
    Ion Beam Workshop 2022, 31.03.-01.04.2022, Jena, Germany

Permalink: https://www.hzdr.de/publications/Publ-34480
Publ.-Id: 34480


Technological assessments on recent developments in fine and coarse particle flotation systems

Ahmad, H.; Mehdi, S.; Hoang, D. H.; Hamid, K.; Boris, A.; Przemyslaw, B. K.

After more than a century applying flotation to the mining industry, two completely different strategies have been introduced for processing purposes. One is the classical approach viz. grinding ores to a certain extent (fine particles) and floating them via conventional mechanical and pneumatic cells i.e., Jameson, Imhoflot™ and Reflux™. This strategy continues because mines face declining cut-off grades, complex and poly-mineralized ores, and they are required to achieve an acceptable degree of mineral liberation. The other school of thought deals with coarse particle processes mainly owing to the low energy requirements, that includes SkimAir® flash, fluidized bed and HydroFloat™ cells. There is no study in the literature to comparatively present the recent developments of flotation apparatuses versus the conventional mechanical cells. To cover this knowledge gap in the literature, the present paper endeavors to critically evaluate these concepts from several points of view, including existing technological advancements, water and energy usage, kinetics, and circuit design. A brief introduction of advanced technologies, along with their applications is presented. The data from literature and case studies showed that the Jameson, Imhoflot™ and recently developed Reflux™ flotation cells can be very effective for recovering fine particles owing to their specific hydrodynamic designs, intensive energy dissipation rate and generation of micron-sized bubbles (100–700 μm). Very low (less than a few minutes) mean particle residence time, high gas-hold up (ca. 50–70 %), no agitation and high efficiency of particle-bubble collision were identified as their main advantages compared to traditional mechanical flotation cells. In addition to their common applications in cleaner stage, these cells were used in pre-flotation and scalping (producing final concentrate from the rougher feed) duties. Their main challenges were recognized as relatively unclear procedure on their scale up/down, optimization and simulation. The HydroFloat™ cell was indicated as a promising technology for recovering coarse particle fraction sizes by taking advantage of the fluidized-bed concept with plug-flow dispersion regime, high particle residence time, and limited cell turbulence. We finally concluded that fine particle flotation may remain as the main focus of re-processing tailings dams, while coarse particle treatment should be the focus of this century to reduce total energy consumptions.

Keywords: Pneumatic flotation cells; Slurry retention time; Technological development; Flotation kinetics; Micron-sized bubbles

Downloads:

  • Secondary publication expected from 22.03.2023

Permalink: https://www.hzdr.de/publications/Publ-34479
Publ.-Id: 34479


Teaching on Software Carpentry (Virtual) (2022-03-28-upr-online)

Shao, Z.

Teaching "Programming with Python" for the workshop.
Workshop recordings are available on .

Keywords: Python

  • Software in external data repository
    Publication year 2022
    Programming language: Python
    System requirements: Python, jupyter
    License: Creative Commons Attribution license (Link to license text)
    Hosted on https://github.com/zdshaoteach/2022-03-28-upr-online: Link to location

Permalink: https://www.hzdr.de/publications/Publ-34478
Publ.-Id: 34478


EZ publication: source code, profiling, analysis and simulation data

Steiniger, K.; Widera, R.; Young, J.

Data of the PIConGPU simulations as used in the publication: EZ: An Efficient, Charge Conserving Current Deposition Algorithm for Electromagnetic Particle-In-Cell Simulations

Data overview:

  • picongpu_source.zip: 
    • source code forked from the PIConGPU mainline version 0.7.0-dev
    • used input set `share/picongpu/examples/PaperThermal`
  • runs_charge_conservation.zip:
    • output including hdf5 dumps to validate charge conservation property for the PaperThermal setup (warm plasma)
  • runs_performance.zip:
    • simulation timings output for Spock CPU, Spock GPU and Summit GPU runs
  • runs_profiling.zip:
    • profile data for Spock GPU and Summit GPU runs
  • runs_singleParticleTest.zip:
    • output including hdf5 dumps to validate charge conservation property for the single particle test
  • analysis_scripts.zip: 
    • jupyter notebooks for setup and analysis of PaperThermal setup
    • python script to plot charge conservation from hdf5 simulation output over time
    • bash script for statistical analysis of performance runs

Keywords: EZ; charge conservation; current deposition; PIConGPU; particle-in-cell; profiling; CUDA; HIP; NVIDIA; AMD; Spock; Summit; HPC

  • Reseach data in the HZDR data repository RODARE
    Publication date: 2022-04-01
    DOI: 10.14278/rodare.1510
    License: CC-BY-4.0

Downloads:

Permalink: https://www.hzdr.de/publications/Publ-34475
Publ.-Id: 34475


Modeling Inhomogeneous Warm Dense Matter

Moldabekov, Z.

The results of the analysis of the accuracy of the commonly used ground-state exchange-correlation (XC) functionals (LDA, PBE, PBEsol, AM05, SCAN) at warm dense matter conditions are presented [1,2]. We considered both unpolarized and polarized electrons. The analysis is performed by comparing to the available path-integral quantum Monte-Carlo (QMC) data. The relative deviation of the total density from the reference data is reported for different XC functionals in the case of the inhomogeneous electron gas. As a key finding of our evaluation, we emphasize that the overall performance of the ground-state XC functionals worsens with increasing the wavenumber of density perturbation.
Finally, the non-linear static density response of electrons is investigated using KS-DFT approach [3]. The results are verified by comparing to the QMC data when thermal temperature is equal to the Fermi temperature. New results for partially and strongly degenerate electrons are presented.

REFERENCES

[1] Z. Moldabekov, T.Dornheim, M. Böhme, J. Vorberger, A. Cangi, The relevance of electronic perturbations in the warm dense electron gas. The Journal of Chemical Physics 155, 124116 (2021).
[2] Z. Moldabekov, T.Dornheim, J. Vorberger, A. Cangi, Benchmarking Exchange-Correlation Functionals in the Spin-Polarized Inhomogeneous Electron Gas under Warm Dense Conditions. Physical Review B, accepted for publication (2022), arXiv:2110.06708 .
[3] Z.Moldabekov, T. Dornheim, J. Vorberger, Density-Functional-Theory Perspective on the Non-Linear Response of Correlated Electrons Across Temperature Regimes, arXiv:2201.01623 (2022)

  • Open Access Logo Invited lecture (Conferences)
    Matter in Extreme Conditions: from MATerial science to Plasmas for Laboratory Astropohysics (MECMATPLA), 12.-19.03.2022, Montgenèvre, FRANCE

Permalink: https://www.hzdr.de/publications/Publ-34474
Publ.-Id: 34474


CTAB-Silica nanoparticle complexes - dynamic surface tension measurements and modeling

Javadi, A.; Jafarlou, A.; Eckert, K.; Miller, R.

The adsorption dynamics of silica nanoparticles (NP) and cetyltrimethylammonium bromide (CTAB) complexes is studied via dynamic surface properties characterization by the drop Profile Analysis Tensiometry (PAT). Considering the hypothesis that a nanoparticle with a certain number of attached surfactant molecules can be considered as a unified surface-active complex, the equilibrium surface tension for fixed CTAB/NP mixing ratios were considered to construct respective adsorption isotherms. The results can be well described by the Frumkin adsorption model. The fitting parameters of the Frumkin model for different mixing ratios demonstrate that complexes with higher mixing ratios occupy less space at the interface and show weaker interaction with each other.

Keywords: Surfactant-nanoparticle interactions; CTAB silica complexes; Diffusion kinetics controlled adsorption; Drop profile analysis tensiometry; Stokes-Einstein equation; Dynamic surface phenomena

Permalink: https://www.hzdr.de/publications/Publ-34472
Publ.-Id: 34472


Influence of Cell Opening Methods on Electrolyte Removal during Processing in Lithium-Ion Battery Recycling

Werner, D. M.; Mütze, T.; Peuker, U. A.

Lithium-Ion batteries (LIBs) are an important pillar for the sustainable transition of the mobility and energy storage sector. LIBs are complex devices for which waste management must incorporate different recycling technologies to produce high-quality secondary (raw) materials at high recycling efficiencies (RE). This contribution on LIB recycling investigated the influence of different pretreatment strategies on the subsequent processing. The experimental study combined different dismantling depths and depollution temperatures with subsequent crushing and thermal drying. Therein, the removal of organic solvent is quantified during liberation and separation. This allows to evaluate the safety of cell opening according to the initial depollution status. These process steps play a key role in the recycling of LIBs when using the low temperature route. Therefore, combinations of pretreatment and processing steps regarding technical and economic feasibility are discussed. Moreover, the process medium and equipment properties for a safe cell opening, the technical recycling efficiencies and their consequences on future industrial LIB waste management are pointed out.

Keywords: Lithium-ion battery; recycling; battery cells; processing; crushing; thermal drying; process routes

Permalink: https://www.hzdr.de/publications/Publ-34471
Publ.-Id: 34471


Data publication: Characterization of protein corona formation on nanoparticles via dynamic interfacial properties analysis: Bovine serum albumin - silica particle case study

Shourni, S.; Javadi, A.; Hosseinpour, N.; Bahramian, A.; Raoufi, M.

Dynamic surface tension and elasticity values of BSA proteins and silica nanoparticles, in separated and also mixed solutions, measured via drop profile analysis tensiometry.

Keywords: Protein corona on nanoparticle (PCN); Bovine serum albumin (BSA); SiO2 nanoparticles; Dynamic surface tension; Kinetics of adsorption; Interfacial elasticity; Drug delivery

Related publications

  • Reseach data in the HZDR data repository RODARE
    Publication date: 2022-04-04
    DOI: 10.14278/rodare.1512
    License: CC-BY-4.0

Downloads:

Permalink: https://www.hzdr.de/publications/Publ-34470
Publ.-Id: 34470


Isotopic cross sections of fragmentation residues produced by light projectiles on carbon near 400A MeV

Boillos, J. M.; Cortina-Gil, D.; Benlliure, J.; Rodríguez-Sánchez, J. L.; Alvarez-Pol, H.; Atar, L.; Aumann, T.; Avdeichikov, V. V.; Beceiro-Novo, S.; Bemmerer, D.; Bertulani, C. A.; Boretzky, K.; Borge, M. J. G.; Caamaño, M.; Caesar, C.; Casarejos, E.; Catford, W.; Cederkall, J.; Chartier, M.; Chulkov, L.; Cravo, E.; Crespo, R. N. P.; Dillmann, I.; Díaz Fernández, P.; Elekes, Z.; Enders, J.; Ershova, O.; Estrade, A.; Farinon, F.; Fraile, L. M.; Freer, M.; Galaviz Redondo, D.; Geissel, H.; Gernhäuser, R.; Golubev, P.; Göbel, K.; Hagdahl, J.; Heftrich, T.; Heil, M.; Heine, M.; Heinz, A.; Henriques, A.; Holl, M.; Hufnagel, A.; Ignatov, A.; Johansson, H. T.; Jonson, B.; Kahlbow, J.; Kalantar-Nayestanaki, N.; Kanungo, R.; Kelic-Heil, A.; Knyazev, A.; Kröll, T.; Kurz, N.; Labiche, M.; Langer, C.; Le Bleis, T.; Lemmon, R.; Lindberg, S.; Machado, J. F. D. C.; Marganiec, J.; Movsesyan, A.; Nacher, E.; Najafi, M. A.; Nilsson, T.; Nociforo, C.; Panin, V.; Paschalis, S.; Perea, A.; Petri, M.; Pietri, S.; Plag, R.; Reifarth, R.; Ribeiro, G.; Rigollet, C.; Rossi, D. M.; Röder, M.; Savran, D.; Scheit, H.; Simon, H.; Sorlin, O.; Syndikus, I. J.; Taylor, J. T.; Tengblad, O.; Thies, R.; Togano, Y.; Vandebrouck, M.; Velho, P. J. F.; Volkov, V.; Wagner, A.; Wamers, F.; Weick, H.; Wheldon, C.; Wilson, G. L.; Winfield, J. S.; Woods, P.; Yakorev, D.; Zhukov, M.; Zilges, A.; Zuber, K.

We measured 135 cross sections of residual nuclei produced in fragmentation reactions of 12C, 14N, and 13−16,20,22O projectiles impinging on a carbon target at kinetic energies of near 400A MeV, most of them for the first time, with the R 3B/LAND setup at the GSI facility in Darmstadt (Germany). The use of this state-of-the-art experimental setup in combination with the inverse kinematics technique gave the full identification in atomic and mass numbers of fragmentation residues with a high precision. The cross sections of these residues were determined with uncertainties below 20% for most of the cases. These data are compared to other previous measurements with stable isotopes and are also used to benchmark different model calculations.

Keywords: low and intermediate energy heavy-ion collisions; nuclear fragmentation; nuclear reactions; unstable nuclear induced reactions; nuclear physics

Permalink: https://www.hzdr.de/publications/Publ-34468
Publ.-Id: 34468


Probing charged lepton flavor violation with the Mu2e experiment

Müller, S.; Ferrari, A.; Knodel, O.; Rachamin, R.

Presentation a 2022 DPG spring meeting (section "Hadrons & Nuclei"), March 31, 2022

Keywords: MU2E; Charged Lepton Flavor Violation; DPG

  • Lecture (Conference) (Online presentation)
    DPG Spring meeting 2022, Section "Hadrons & Nuclei", 28.03.-01.04.2022, virtual, Germany

Permalink: https://www.hzdr.de/publications/Publ-34467
Publ.-Id: 34467


Electrical Conductivity of Iron under Earth-Core Conditions from Time-Dependent Density Functional Theory (APS)

Ramakrishna, K.; Lokamani, M.; Baczewski, A.; Vorberger, J.; Cangi, A.

Time-dependent density functional theory (TDDFT) enables calculating electronic transport properties in the warm dense matter (WDM) and is an alternative to present state-of-the-art approaches. In the real-time formalism of TDDFT (RT-TDDFT), the electrical conductivity is directly computed from the time evolution of the electronic current density and provides direct means to assess the validity of Ohm's law in WDM. Without relying on the methods of diagonalization, the method is computationally fast compared to linear-response TDDFT (LR-TDDFT). We present TDDFT calculations of the electrical conductivity in iron within the pressure and temperature ranges found in Earth's core and discuss the ramifications of using TDDFT for calculating the electrical conductivity in contrast to the Kubo-Greenwood (KG) formalism and dielectric models.

  • Lecture (Conference) (Online presentation)
    APS March meeting 2022 (Session: Matter at Extreme Conditions: Planetary Materials I), 14.03.2022, Chicago, USA

Permalink: https://www.hzdr.de/publications/Publ-34464
Publ.-Id: 34464


Tuning of Curie temperature in Mn5Ge3 films

Xie, Y.; Birowska, M.; Simon Funk, H.; Anita Fischer, I.; Schwarz, D.; Schulze, J.; Zeng, Y.-J.; Helm, M.; Zhou, S.; Prucnal, S.

We report a change in the structural and magnetic properties of epitaxial Mn5Ge3 on a Ge-on-Si (111) substrate by applying strain engineering through ms-range flash lamp annealing (FLA). X-ray diffraction results demonstrate that during FLA for 20 ms, the formation of nonmagnetic MnxGey secondary phases is suppressed, while the in-plane expansion of the lattice increases with increasing annealing temperature. Temperature-dependent magnetization results indicate that the Curie temperature of Mn5Ge3 rises from 287 K in the as-prepared sample to above 400 K after FLA, making Mn5Ge3 an attractive material for spintronics. Experimental results together with theoretical Monte Carlo simulations allow us to conclude that the expansion of the in-plane lattice causes the increase of the Curie temperature due to enhancement of the ferromagnetic interaction between Mn atoms.

Keywords: Strain engineering; flash lamp annealing (FLA); Curie temperature; ferromagnetic material; epitaxial film

Related publications

  • Open Access Logo Journal of Applied Physics 131(2022), 105102
    Online First (2022) DOI: 10.1063/5.0066717

Permalink: https://www.hzdr.de/publications/Publ-34461
Publ.-Id: 34461


Optimized activation for quantum-inspired self-supervised neural network based fully automated brain lesion segmentation

Konar, D.; Bhattacharyya, S.; Dey, S.; Panigrahi, B. K.

Due to the lack of appropriate tailoring of the inter-connection weights, the segmentation performance of the recently suggested Quantum-inspired Self-supervised Neural Network models suffers from the slow convergence problem. As a result, using quantum-inspired meta-heuristics in Quantum-Inspired Self-supervised Neural Network models improves their hyper-parameters and inter-connection weights. The goal of this paper is to propose an improved version of a Quantum-Inspired Self-supervised Neural Network (QIS-Net) model for brain lesion segmentation. The proposed Optimized Quantum-Inspired Self-supervised Neural Network (Opti-QISNet) model is based on the QIS-Net architecture, and its operations are used to get the best segmentation results. A Quantum-Inspired Optimized Multi-Level Sigmoidal (Opti-QSig) activation is the optimized activation function used in the described model. Three quantum-inspired meta-heuristics improve the Opti-QSig activation function, with fitness evaluated using Otsu’s multi-level thresholding. Experiments were carried out using brain MR images from the Cancer Imaging Archive (TCIA) in the Nature data repository. The results show that the proposed self-supervised Opti-QISNet model outperforms our recently established QIBDS Net and QIS-Net models in brain lesion segmentation, and it is a potential candidate to extensively supervised neural network based architectures (UNet and FCNNs).

Keywords: Quantum computing; U-Net; QIBDS Net; MR Images

Permalink: https://www.hzdr.de/publications/Publ-34460
Publ.-Id: 34460


Mu2e-II: Muon to electron conversion with PIP-II

Byrum, K.; Corrodi, S.; Oksuzian, Y.; Winter, P.; Xia, L.; Edmonds, A. W. J.; Miller, J. P.; Mott, J.; Marciano, W. J.; Szafron, R.; Bonventre, R.; Brown, D. N.; Kolomensky, Y. G.; Ning, O.; Singh, V.; Prebys, E.; Borrel, L.; Echenard, B.; Hitlin, D. G.; Hu, C.; Lin, D. X.; Middleton, S.; Porter, F. C.; Zhang, L.; Zhu, R.-Y.; Ambrose, D.; Badgley, K.; Bernstein, R. H.; Boi, S.; Casey, B. C. K.; Culbertson, R.; Gaponenko, A.; Glass, H. D.; Glenzinski, D.; Goodenough, L.; Hocker, A.; Kargiantoulakis, M.; Kashikhin, V.; Kiburg, B.; Kutschke, R. K.; Murat, P. A.; Neuffer, D.; Pronskikh, V. S.; Pushka, D.; Rakness, G.; Strauss, T.; Yucel, M.; Bloise, C.; Diociaiuti, E.; Giovannella, S.; Happacher, F.; Miscetti, S.; Sarra, I.; Martini, M.; Ferrari, A.; Müller, S.; Rachamin, R.; Barlas-Yucel, E.; Artikov, A.; Atanov, N.; Davydov, Y. I.; Glagolev, V.; Vasilyev, I. I.; Brown, D. N.; Uesaka, Y.; Denisov, S. P.; Evdokimov, V.; Kozelov, A. V.; Popov, A. V.; Vasilyev, I. A.; Tassielli, G.; Teubner, T.; Chislett, R. T.; Hesketh, G. G.; Lancaster, M.; Campbell, M.; Ciampa, K.; Heller, K.; Messerly, B.; Cummings, M. A. C.; Calibbi, L.; Blazey, G. C.; Syphers, M. J.; Zutshi, V.; Kampa, C.; Mackenzie, M.; Di Falco, S.; Donati, S.; Gioiosa, A.; Giusti, V.; Morescalchi, L.; Pasciuto, D.; Pedreschi, E.; Spinella, F.; Hedges, M. T.; Jones, M.; You, Z. Y.; Zanetti, A. M.; Valetov, E. V.; Dukes, E. C.; Ehrlich, R.; Group, R. C.; Heeck, J.; Hung, P. Q.; Demers, S. M.; Pezzullo, G.; Lynch, K. R.; Popp, J. L.

An observation of Charged Lepton Flavor Violation (CLFV) would be unambiguous evidence for
physics beyond the Standard Model. The Mu2e and COMET experiments, under construction, are
designed to push the sensitivity to CLFV in the μ → e conversion process to unprecedented levels.
Whether conversion is observed or not, there is a strong case to be made for further improving
sensitivity, or for examining the process on additional target materials. Mu2e-II is a proposed
upgrade to Mu2e, with at least an additional order of magnitude in sensitivity to the conversion
rate over Mu2e. The approach and challenges for this proposal are summarized. Mu2e-II may be
regarded as the next logical step in a continued high-intensity muon program at FNAL.

Keywords: Charged Lepton Flavor Violation; Muon to Electron conversion; Mu2e; FLUKA

  • Open Access Logo Contribution to proceedings
    Particle Physics Community Planning Exercise (SNOWMASS), 17.-26.07.2022, Seattle, USA
    DOI: 10.48550/arXiv.2203.07569

Permalink: https://www.hzdr.de/publications/Publ-34459
Publ.-Id: 34459


A user-friendly R Platform for Optimizing Mineral Processing

Ben Said, B.; Pereira, L.; Tolosana Delgado, R.; Rudolph, M.

An open-source and user-friendly platform for using design of experiments for optimizing mineral processing. No specific knowledge of programming languages is required for using the platform. Depending on the user needs, the platform suggests the optimal experimental strategy with a minimum number of runs required. Different types of experimental designs such as screening, full factorial and central composite designs are currently available. The R shiny app can be accessed via:  https://hifgeomet.shinyapps.io/Optimization_Tool/

Keywords: Design of experiments; Plant optimization; Mineral processing; Shiny R; Process Modelling

  • Software in the HZDR data repository RODARE
    Publication date: 2022-03-24
    DOI: 10.14278/rodare.1498
    License: CC-BY-1.0

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Permalink: https://www.hzdr.de/publications/Publ-34457
Publ.-Id: 34457


Developing Accelerator Mass Spectrometry Capabilities for Anthropogenic Radionuclide Analysis to Extend the Set of Oceanographic Tracers

Hain, K.; Martschini, M.; Gülce, F.; Honda, M.; Lachner, J.; Kern, M.; Pitters, J.; Quinto, F.; Sakaguchi, A.; Steier, P.; Wiederin, A.; Wieser, A.; Yokoyama, A.; Golser, R.

Recent major advances in Accelerator Mass Spectrometry (AMS) at the Vienna Environmental Research Accelerator (VERA) regarding detection efficiency and isobar suppression have opened possibilities for the analysis of additional long-lived radionuclides at ultra-low environmental concentrations. These radionuclides, including 233U, 135Cs, 99Tc, and 90Sr, will become important for oceanographic tracer application due to their generally conservative behavior in ocean water. In particular, the isotope ratios 233U/236U and 137Cs/135Cs have proven to be powerful fingerprints for emission source identification as they are not affected by elemental fractionation. Improved detection efficiencies allowed us to analyze all major long-lived actinides, i.e., 236U, 237Np, 239,240Pu, 241Am as well as the very rare 233U, in the same 10 L water samples of a depth profile from the northwest Pacific Ocean. For this purpose, a simplified and very flexible chemical purification procedure based on extraction chromatography (a single UTEVA® column) was implemented which can be extended by a DGA® column for Am purification. The procedure was validated with the reference materials IAEA-381/385. With the additional increase in ionization efficiency expected for the extraction of actinides as fluoride molecules from the AMS ion source, a further reduction of chemical processing may become possible. This method was successfully applied to an exemplary set of air filter samples. In order to determine the quantitative 237Np concentration reliably, a 236Np spike material is being developed in collaboration with the University of Tsukuba, Japan. Ion-Laser Interaction Mass Spectrometry (ILIAMS), a novel technique for the efficient suppression of stable isobaric background, has been developed at VERA and provides unprecedented detection sensitivity for the fission fragments 135Cs, 99Tc, and 90Sr. The corresponding setup is fully operational now and the isobar suppression factors of >105 achieved, in principle, allow for the detection of the mentioned radionuclides in the environment. Especially for 90Sr analysis, this new approach has already been validated for selected reference materials (e.g., IAEA-A-12) and is ready for application in oceanographic studies. We estimate that a sample volume of only (1–3) L ocean water is sufficient for 90Sr as well as for 135Cs analysis, respectively.

Permalink: https://www.hzdr.de/publications/Publ-34456
Publ.-Id: 34456


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