Publications Repository - Helmholtz-Zentrum Dresden-Rossendorf

"Online First" included
Approved and published publications
Only approved publications

39109 Publications

Using Frontier for CAAR Plasma-In-Cell (PIC) on GPU application

Steiniger, K.; Debus, A.; Chandrasekaran, S.

Presentation of PIConGPU at DOE Booth at Supercomputing 2022

Keywords: PIConGPU; particle-in-cell; laser plasma accelerators

  • Poster
    The International Conference for High Performance Computing, Networking, Storage, and Analysis, 13.-18.11.2022, Dallas, Texas, United States of America

Publ.-Id: 35912

Development of a new quantum trajectory molecular dynamics framework

Svensson, P.; Campbell, T.; Graziani, F.; Moldabekov, Z.; Lyu, N.; Richardson, S.; Vinko, S. M.; Gregori, G.

An extension to the wave packet description of quantum plasmas is presented, where the wave packet can be elongated in arbitrary directions. A generalised Ewald summation is constructed for the wave packet models accounting for long-range Coulomb interactions and fermionic effects are approximated by purpose-built Pauli potentials, self-consistent with the wave packets used. We demonstrate its numerical implementation with good parallel support and close to linear scaling in particle number, used for comparisons with the more common wave packet employing isotropic states. Ground state and thermal properties are compared between the models with differences occurring primarily in the electronic subsystem. Especially, the electrical conductivity of dense hydrogen is investigated where a 15% increase in DC conductivity can be seen in our wave packet model compared to other models.

Keywords: wave packet molecular dynamics; warm dense matter; Pauli potential

Publ.-Id: 35911

Optimizing laser plasma acceleration performance for proton beams beyond the 100 MeV frontier

Ziegler, T.; Assenbaum, S.; Bernert, C.; Brack, F.-E.; Cowan, T.; Dover, N. P.; Garten, M.; Gaus, L.; Göthel, I.; Kiriyama, H.; Kluge, T.; Kon, A.; Kraft, S.; Kroll, F.; Metzkes-Ng, J.; Nishuichi, M.; Reimold, M.; Rehwald, M.; Schlenvoigt, H.-P.; Umlandt, M. E. P.; Schramm, U.; Vescovi Pinochet, M. A.; Zeil, K.

Exploiting the strong electromagnetic fields that can be supported by a laser driven compact plasma accelerator enables generation of short, high-intensity pulses of high energy ions with special beam properties. The maturation of such laser driven ion accelerators from physics experiments to turn-key sources for applications will rely on breakthroughs in both, generated beam parameters (kinetic energy, flux), as well as increased scrutiny on reproducibility, robustness, and scalability to high repetition rate.
Recent developments at the high-power laser facility DRACO-PW enabled the production of polychromatic proton beams with unprecedented stability [1]. This facilitated the first in vivo radiobiological study using a laser-driven proton source [2]. For many related advanced applications, the ability to generate proton beams with energies beyond the 100 MeV frontier at a repetition rate and in a controllable way is essential and the subject of ongoing research.
Latest experimental studies concentrated on pre-expanded plastic foil target undergoing relativistically induced transparency using linearly polarized laser pulses with peak intensities beyond 1021 W/cm2. A complex suite of particle and optical diagnostics allowed characterization of spatial and spectral proton beam parameters and the stability of this regime for best acceleration performance exceeding 100 MeV cut-off energies. Combined hydrodynamic and 3D particle-in-cell simulations helped to identify the most promising target parameter range matched to the carefully measured prevailing laser contrast conditions.

  • Invited lecture (Conferences)
    Garchinger Maier-Leibnitz Kolloquium, 15.12.2022, Garching, Deutschland

Publ.-Id: 35910

Alternating Screening And Higher Harmonics In Complex Plasmas

Moldabekov, Z.

Modeling properties of strongly correlated many-particle systems are of both fundamental and practical importance. At the same time, generating and probing these properties is challenging. To this end, laboratory model systems play a central role in studying correlated many-particle phenomena. In this presentation, we focus on a specific laboratory model system – dusty plasmas – to model collective particle behavior under controlled conditions. Thereby, we push the frontier of dusty plasma physics by predicting the generation of high harmonics in dusty plasmas with alternating screening length [1]. We found a simple phenomenological expression for the dispersion relation of higher harmonics. Moreover, it is shown that the periodically alternating screening causes a self-conjugate state with negative refraction. As the application, we speculate that our findings can serve as a test bed for studying the fundamental physics of a self-conjugate state with negative refraction in strongly correlated systems on the kinetic level.

[1] Z. A. Moldabekov et al., Phys. Rev. Research 3, 043187 (2021)

Keywords: strongly correlated many-particle systems; plasma physics; generation of high harmonics

  • Invited lecture (Conferences) (Online presentation)
    6th Asia Pacific Conference on Plasma Physics, 09.-14.10.2022, virtual, virtual

Publ.-Id: 35909

Quantum linear and non-linear density response of electrons

Moldabekov, Z.

Warm dense matter is the state of matter naturally appearing in interiors of planets and stars. In laboratory warm dense matter is generated by laser heating and shock compression. Warm dense matter is also important as a transient state on the way to ignition in inertial confinement fusion experiments. Density response properties are important for the understanding process in warm dense matter for computation of optical and transport characteristics. In this presentation, I will discuss the theoretical foundations of the linear and non-linear density response theory for warm dense matter. Going beyond theoretical formulations, the calculations based on the KS-DFT method will be presented.

Keywords: warm dense matter; non-linear response; exchange-correlation kernel

  • Invited lecture (Conferences)
    10th International Symposium "Optics & its applications", 05.-10.12.2022, Cali, Colombia

Publ.-Id: 35907

Material Specific Exchange-Correlation Kernel for WDM

Moldabekov, Z.

We developed a new method that allows one to compute material specific static exchange-correlation kernel across temperature regimes using standard DFT codes and for any XC functional available in Libxc [1]. In this presentation we show the results of the static exchange-correlation kernel analysis from computations using various XC functionals for dense electron gas and warm dense hydrogen. By comparing the data to the exact QMC results, we are able to understand the effect of thermal excitations and density inhomogeneity on the exchange-correlation kernel. Moreover, we discuss the results of the analysis of the accuracy of the commonly used exchange-correlation (XC) functionals for warm dense matter simulations [2-4]. The analysis is performed by comparing highly accurate path-integral quantum Monte-Carlo (QMC) data with KS-DFT results. Finally, a new methodology for the investigation of the non-linear static density response of WDM based on the KS-DFT method is presented [5].

[1] Zhandos A. Moldabekov, Maximilian Böhme, Jan Vorberger, David Blaschke, Tobias Dornheim, arXiv:2209.00928 (2022).
[2] Z. Moldabekov, T.Dornheim, M. Böhme, J. Vorberger, A. Cangi, The Journal of Chemical Physics 155, 124116 (2021).
[3] Z. Moldabekov, T.Dornheim, J. Vorberger, A. Cangi, Phys. Rev. B 105, 035134 (2022).
[4] Z. A. Moldabekov, T. Dornheim, G. Gregori, F. Graziani, M. Bonitz, A. Cangi, SciPost Phys. 12, 062 (2022).
[5] Z.Moldabekov, J. Vorberger, T. Dornheim, Journal of Chemical Theory and Computation 18, 2900–2912 (2022).

Keywords: warm dense matter; hybrid functionals; KS-DFT; exchange-correlation kernel

  • Lecture (Conference)
    10 th Workshop on High Pressure, Planetary and Plasma Physics (10HP4), 28.-29.09.2022, Brussels, Belgium

Publ.-Id: 35906

Ab Initio Static Exchange–Correlation Kernel From DFT

Moldabekov, Z.

The KS-DFT is the standard method to model the electronic structure due to its accuracy and computational efficiency. The reduction in computation cost compared to other ab initio methods is due to a formally exact mapping onto an effective single-electron problem. DFT calculations of a various material properties require as input the so-called exchange—correlation (XC) kernel. Yet, little is known about the actual kernel of real materials, and hitherto no reliable universal way to compute it has been known. In this work, we present a new methodology to compute the static XC-kernel of any material; which needs no external input apart from the usual XC-functional. The application of the method is demostrated for the uniform electron gas and hydrogen. Moreover, we consider both ambient conditions and the warm-dense matter (WDM) parameters. In addition, our analysis of the static XC-kernel gives us valuable new insights into the construction of the XC-functionals for the application at WDM regime.

  • Lecture (Conference)
    Multiscale Modeling of Matter under Extreme Conditions, 11.-16.09.2022, Görlitz, Germany

Publ.-Id: 35905

Analyzing XC functionals for electronic structure calculations at WDM parameters

Moldabekov, Z.; Dornheim, T.; Cangi, A.; Böhme, M.; Vorberger, J.

In this presentation we discuss the results of the analysis of the accuracy of the commonly used exchange-correlation (XC) functionals for warm dense matter simulation [1,2]. The analysis is performed by comparing the path-integral quantum Monte-Carlo (QMC) data with KS-DFT results. 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. Furthermore, a new methodology for the investigation of the non-linear static density response WDM based on KS-DFT method is presented [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. Finally, we present the results of the analysis of the electronic local field correction as computed using various XC functionals. By comparing the data to the exact QMC results, we are able to understand the effect of the thermal excitations on XC functional.

[1] Z. Moldabekov, T.Dornheim, M. Böhme, J. Vorberger, A. Cangi, The Journal of Chemical Physics 155, 124116 (2021).
[2] Z. Moldabekov, T.Dornheim, J. Vorberger, A. Cangi, Phys. Rev. B 105, 035134 (2022).
[3] Z.Moldabekov, T. Dornheim, J. Vorberger, Journal of Chemical Theory and Computation (2022).

Keywords: warm dense matter; exchange-correlation functionals; KS-DFT

  • Lecture (Conference)
    Strongly Coupled Coulomb Systems (SCCS), 24.-29.07.2022, Goerlitz, Germany

Publ.-Id: 35904

QED.jl - Strong-field particle physics code

Hernandez Acosta, U.; Steiniger, K.; Jungnickel, T.; Bussmann, M.

The collision of relativistic electron beams with highly intense, highly energetic and
short-pulsed light will give deep insights into the interactions of electromagnetic fields
and matter at extreme scales. Experimentally, those collisions might be addressed
at upcoming projects like HIBEF 2.0 at the EuropeanXFEL, SYLOS at ELI-ALPS or
LCLS-II at SLAC, to name a few. The precise theoretical description of such collision
experiments is very challenging and not fully covered by the currently available tools,
known from particle physics. We develop the open-source software library QED.jl,
which targets those gaps by
Modelling of (non-linear) Quantum Processes
providing new developments of
pair production
state-of-the-art modelling tools w.r.t.
inelastic scattering
and annihilation
strong-field physics. This includes

  • Modelling of particle physics
processes: calculation of Matrix
element and cross section
  • Monte-Carlo event generation:
Parallelised drawing of samples
from multivariate distributions,
  • Multivariate integration:
Algorithms for highly oscillatory
problems and Monte-Carlo
integration for Total cross sections
Monte-Carlo Event-Generator
Large-Scale Simulation
QED.jl is written in the Julia
Laser-Matter Collision Experiments
programming language, which
opens up the usage of modern
language features like just-in-time compilation, multiple-dispatch and meta-
programming to attain efficiency in execution time, where the code is still easy to use
and develop. Consequently, based on the computational demanding tasks given by
the physics use case, necessary advances w.r.t. distributed computing are planed to
be developed using Julia:
  • Task scheduling using directed acyclic graphs:
Generation of compute graphs from specific physical models, and optimisation of
the evaluation of such graphs in parallel,
  • Code injection:
Extension of Julia compile workflow by injecting problem specific C++ code,
  • Hardware-agnostic parallelisation:
Kernel abstractions in Julia, e.g. by using ALPAKA

Keywords: SFQED; QED.jl

  • Poster
    Big data analytical methods for complex systems, 06.-07.10.2022, Wroclaw, Polska

Publ.-Id: 35903

Excitations of an Inhomogeneous Electronic System: From Ambient Conditions to Warm Dense Matter

Moldabekov, Z.

Warm dense matter (WDM) is the state of matter at high pressures and temperatures. WDM is
relevant both for practical applications and for fundamental science. The practical significance is
due to the generation of the WDM state in experiments on nuclear fusion and the creation of new
materials under extreme conditions. From the point of view of fundamental science, the relevance
of WDM is due to the extreme conditions in the interiors of planets and stars.
Many questions regarding the interplay of quantum degeneracy, thermal excitations, and strong
correlations effects in WDM remain open. To solve this problem, we use an externally perturbed
WDM to investigate how electronic structure and excitations are affected by thermal excitations
and density inhomogeneities. The results are reported in our recent articles [1-4], where we
presented: a study of the quality of various exchange-correlation functionals in the KS-DFT method
[1,2]; the change in electronic excitations due to strong inhomogeneity and thermal effects [3]; and
a new KS-DFT based methodology for the investigation of the non-linear response of electrons
across temperature regimes relevant for WDM [4].

[1] Z. Moldabekov, T. Dornheim, M. Boehme, J. Vorberger, A. Cangi, J. Chem.Phys. 155 (2021)
[2] Z. Moldabekov, T. Dornheim, J. Vorberger, A. Cangi, Phys. Rev. B 105 (2022) 035134.
[3] Z. Moldabekov, T. Dornheim, A. Cangi, Sci. Rep. 12 (2022) 1093.
[4] Z. Moldabekov, J. Vorberger, T. Dornheim, J. Chem. Theory Comput. 18 (2022) 2900

Keywords: warm dense matter; extreme conditions; non-linear response

  • Invited lecture (Conferences)
    UWr-HZDR-CASUS International Conference on Advanced Systems Research CASUSCON, 11.-15.07.2022, Wrocław, Poland

Publ.-Id: 35902

Inhomogeneous electron gas under warm dense conditions

Moldabekov, Z.; Dornheim, T.; Vorberger, J.

Warm dense matter (WDM) is a state of matter with parameters between solids and
dense plasmas. WDM is characterized by the relevance of quantum degeneracy, thermal
excitations, and strong correlations. Many questions regarding the interplay of these
effects in WDM remain open. In this paper, we use an externally perturbed electron gas
to investigate how electronic structure and excitations are affected by thermal excitations
and density inhomogeneities. The results are reported in our recent articles [1-4]. We
present a study of the quality of various exchange-correlation functionals in the KS-DFT
method [1,2]. In addition, we show how electronic excitations change due to strong
inhomogeneity and thermal effects [3]. Based, on these results, we present a new KS-DFT
based methodology for the investigation of the non-linear response of electrons across
temperature regimes relevant for WDM [4].

[1] Z. Moldabekov, T.Dornheim, M. Boehme, J. Vorberger, A. Cangi, The Journal of Chem-
ical Physics 155, 124116 (2021).
[2] Z. Moldabekov, T.Dornheim, J. Vorberger, A. Cangi, Phys. Rev. B 105, 035134 (2022).
[3] Z. Moldabekov, T.Dornheim, A. Cangi, Scientific Reports 12, 1093 (2022)
[4] Z.Moldabekov, J. Vorberger, T. Dornheim, Journal of Chemical Theory and Computation,
accepted for publication (2022); arXiv:2201.01623.

Keywords: warm dense matter; exchange-correlation functionals; non-linear response

  • Lecture (Conference)
    The 13th International Conference on High Energy Density Laboratory Astrophysics HEDLA 2022, 23.-27.05.2022, Lisbon, Portugal

Publ.-Id: 35901

Accompanying the hybrid LPWFA experiment campaign with a computer simulation campaign: What we model, what we learn, and where we need to become better

Steiniger, K.; Pausch, R.; Bastrakov, S.; Chang, Y.-Y.; Couperus Cabadağ, J. P.; Irman, A.; Köhler, A.; Kurz, T.; Schöbel, S.; Widera, R.; Schramm, U.; Zarini, O.; Debus, A.; Bussmann, M.; Heinemann, T.; Assmann, R. W.; Martinez De La Ossa, A.; Hidding, B.; Gilljohann, M. F.; Ding, H.; Götzfried, J.; Schindler, S.; Döpp, A.; Karsch, S.; Kononenko, O.; Raj, G.; Corde, S.

The Hybrid Collaboration, a joint undertaking by HZDR, DESY, University of Strathclyde, LMU, and LOA, performed hybrid LPWFA experiments which utilize electron bunches from a laser wakefield accelerator (LWFA) as drivers of a plasma wakefield stage (PWFA) to demonstrate the feasibility of compact PWFAs serving as a test bed for the efficient investigation and optimization of PWFAs and their development into brightness boosters. To better understand the microscopic, nonlinear dynamic of these accelerators, the experiments were accompanied by 3D3V particle-in-cell simulations using PIConGPU.

Here, we present insights into the dynamics of the hybrid LPWFA that we gained from start-to-end simulations of the experimental setup at HZDR.
These regard electron injections due to hydrodynamic shocks, beam self-modulation and breakup, and cavity elongation - all backed-up by synthetic diagnostics that allow direct comparison with experimental measurements.
We discuss our approach to model these synthetic diagnostics directly within the PIConGPU simulation as well as modelling certain aspects of the experimental setup, such as the drive laser. Continuing this, the talk highlights a few recent technical advances in PIConGPU that enable better modelling of the micro-physics, experiment conditions, or signals of experiment diagnostics.

Keywords: laser; plasma; laser wakefield acceleration; LPWFA; particle-in-cell; PIConGPU; digital twin

  • Open Access Logo Invited lecture (Conferences)
    Advanced Accelerator Concepts Workshop, 06.-11.11.2022, Hauppauge, New York, United States of America


Publ.-Id: 35900

Assessing the accuracy of hybrid exchange-correlation functionals for the density response of warm dense electrons

Moldabekov, Z.; Lokamani, M.; Vorberger, J.; Cangi, A.; Dornheim, T.

We assess the accuracy of common hybrid exchange-correlation (XC) functionals (PBE0, PBE0-1/3, HSE06, HSE03, and B3LYP) within Kohn-Sham density functional theory (KS-DFT) for the harmonically perturbed electron gas at parameters relevant for the challenging conditions of warm dense matter. Generated by laser-induced compression and heating in the laboratory, warm dense matter is a state of matter that also occurs in white dwarfs and planetary interiors. We consider both weak and strong degrees of density inhomogeneity induced by the external field at various wavenumbers. We perform an error analysis by comparing to exact quantum Monte-Carlo results. In the case of a weak perturbation, we report the static linear density response function and the static XC kernel at a metallic density for both the degenerate ground-state limit and for partial degeneracy at the electronic Fermi temperature. Overall, we observe an improvement in the density response for partial degeneracy when the PBE0, PBE0-1/3, HSE06, and HSE03 functionals are used compared to the previously reported results for the PBE, PBEsol, LDA, AM05, and SCAN functionals; B3LYP, on the other hand, does not perform well for the considered system. Together with the reduction of self-interaction errors, this seems to be the rationale behind the relative success of the HSE03 functional for the description of the experimental data on aluminum and liquid ammonia at WDM conditions.

Keywords: warm dense matter; hybrid functionals; Hartree-Fock

Publ.-Id: 35898

Non-empirical mixing coefficient for hybrid XC functionals from analysis of the XC kernel

Moldabekov, Z.; Lokamani, M.; Vorberger, J.; Cangi, A.; Dornheim, T.

We present an analysis of the static exchange-correlation (XC) kernel computed from hybrid functionals with a single mixing coefficient such as PBE0 and PBE0-1/3. We break down the hybrid XC kernels into the exchange and correlation parts using the Hartree-Fock functional, the exchange-only PBE, and the correlation-only PBE. This decomposition is combined with exact data for the static XC kernel of the uniform electron gas and an Airy gas model within a subsystem functional approach. This gives us a tool for the nonempirical choice of the mixing coefficient at ambient and extreme conditions. Our analysis provides physical insights into the effect of the variation of the mixing coefficient in hybrid functionals, which is of immense practical value. The presented approach is general and can be used for other type of functionals like screened hybrids.

Keywords: warm dense matter; hybrid functionals; Hartree-Fock

Publ.-Id: 35897

Materials Research in High Magnetic Fields

Wosnitza, J.

Für diesen Vortrag hat keine Kurzfassung vorgelegen.

  • Invited lecture (Conferences)
    UWr-CASUS-HZDR International Conference (CASUSCON) on Advanced Systems Research, 11.-15.07.2022, Wroclaw, Polen

Publ.-Id: 35896

Research and technology at the Dresden High Magnetic Field Laboratory (HLD)

Herrmannsdörfer, T.

The Dresden High Magnetic Field Laboratory (Hochfeld-Magnetlabor Dresden, HLD) is a user facility for experiments at extreme sample conditions and an institute of the HZDR as well. The HLD provides access to magnets and measurement equipment that allows for experiments up to the feasibility limits of the magnetic-field scale. In particular, research on quantum condensed matter with novel electronic or magnetic properties is the central research area at HLD. As a central task, the HLD develops and operates world-class pulsed high-field magnets to make them available for excellent research by external and in-house users. It is the only installation in Germany and one of the four large user facilities in Europe which operate high-field magnets in combination with advanced measurement techniques; the other partner facilities are located in Grenoble, Nijmegen and Toulouse. The close cooperation between these high-field laboratories has been formalized by the foundation of the European Magnetic Field Laboratory (EMFL). Via a peer-reviewed proposal system, centrally managed by EMFL, the HLD provides leading-edge and in part unique experimental capabilities allowing for high-resolution measurement techniques for materials research in state-of-the-art pulsed magnets reaching top-level field strengths. All these experimental techniques are available over a broad temperature range too, most even down to millikelvin temperatures. The combination of infrared radiation produced by free-electron lasers of the neighboring superconducting electron accelerator ELBE with pulsed-field magnets is world unique. At HLD, a technology-development program for nondestructive pulsed magnets and pulsed power supplies is being carried out allowing to provide the highest possible fields for internal and external users. Various types of pulsed magnets have been designed and are in operation with recently realized dual-coil systems reaching magnetic fields of 85 and 95 T, available for users. Furthermore, a development program for pulsed-power supplies providing electrical currents of several 100 kA as well as electrical power of several GW is in work. These technological activities which make also use of modern simulation methods are under way for realizing a dedicated power supply at the European XFEL (HIBEF project) and for industrial applications, e.g. for electromagnetic pulse forming, joining, and welding as well as for medical engineering and hydrogen liquefaction. In cooperation with industrial and EMFL partners, the HLD will develop a new generation of all-superconducting high-field coils.

  • Invited lecture (Conferences)
    Workshop “Transfer to Industry” - COST Action MAGNETOFON - Ultrafast opto-magneto-electronics for non-dissipative information technology, 07.06.2022, Dresden, Deutschland

Publ.-Id: 35895

Wie kann man Selten Erd Elemente nachhaltiger (zurück)gewinnen?

Daumann, L.; Lederer, F.

Gemeinsamer Beitrag in der Umweltzeitung zu biologischen Wegen der nachhaltigen Rückgewinnung von Selten Erd Elementen.

Keywords: Lanmodulin; Peptide; Biokollektoren

  • Umweltzeitung 30(2023), 12-13
    ISSN: 0948-1370 H 13873F

Publ.-Id: 35894

Biomolecular Toolbox for Resource Recovery

Lederer, F.

Presentation of the biomolecular toolbox of the biotechnology department and the BioKollekt research.

Keywords: Peptides; Biotensides; Siderophores; Organic acids; resource recovery

  • Lecture (others)
    2nd Workshop of the topic RESOURCE AND ENERGY EFFICIENCY, 07.-08.12.2022, Dresden, Deutschland

Publ.-Id: 35893

Why system and multi-disciplinarity thinking is key to circularity

Lederer, F.; Dirlich, S.; Pereira, T.; Mütze, T.; Raatz, S.; Gutzmer, J.

Presentation of research approaches at HIF towards a circular economy

Keywords: circular economy; recycling; battery recycling; biobased recycling tools

  • Invited lecture (Conferences)
    1st Continental Automotive Sustainability Conference, 20.10.2022, Wiesbaden, Deutschland

Publ.-Id: 35892

Added value from residues: Potential and relevance of a circular economy

Lederer, F.

Presentation of circular economy approaches at HIF

Keywords: circular economy; sustainability; recycling; biobased recycling tools

  • Invited lecture (Conferences)
    4. Sächsisch-Polnischer Innovationstag, 15.-16.09.2022, Wroclaw, Polen

Publ.-Id: 35891

ENERGY TRANSITION Towards a more sustinable energy supply

Lederer, F.; Dirlich, S.

Nachhaltigkeit und Natur: Der Fokus des Clusters liegt auf der Frage, wie eine Transition hin zu einer klimafreundlichen Energieversorgung nachhaltig gelingen kann, da diese zwar CO2-Neutralität garantiert, dabei aber auf Ressourcen - wie beispielsweise seltene Erden - angewiesen ist, die selbst wiederum unter fraglichen Bedingungen abgebaut werden und dabei andere bedenkliche Abhängigkeitsverhältnisse entstehen lassen. Wir möchten die Frage aufgreifen, wie mit dem Dilemma umgegangen werden kann, dass endliche natürliche Ressourcen mit einem prinzipiell unendlichen Wachstumsstreben einer profitorientierten Wirtschaft konfrontiert sind. Mit anderen Worten:Wie können wir dem Klimawandel begegnen und den Übergang zu einer klimaneutralen Wirtschaft meistern, ohne auf die Ausbeutung von Menschen und
Raubbau an der Natur zurückgreifen zu müssen?

Keywords: Circular economy; energy transition; rare earth elements; club of rome; Biorecycling

  • Invited lecture (Conferences) (Online presentation)
    Deutsch-baltische Konferenz, 27.-30.10.2022, Riga, Lettland

Publ.-Id: 35890

Transient Laser-Induced Breakdown of Dielectrics in Ultrarelativistic Laser-Solid Interactions

Bernert, C.; Assenbaum, S.; Bock, S.; Brack, F.-E.; Cowan, T.; Curry, C. B.; Garten, M.; Gaus, L.; Gauthier, M.; Gebhardt, R.; GöDe, S.; Glenzer, S. H.; Helbig, U.; Kluge, T.; Kraft, S.; Kroll, F.; Obst-Huebl, L.; Püschel, T.; Rehwald, M.; Schlenvoigt, H.-P.; Schoenwaelder, C.; Schramm, U.; Treffert, F.; Vescovi Pinochet, M. A.; Ziegler, T.; Zeil, K.

For high-intensity laser-solid interactions, the absolute density and surface density gradients of the target at the arrival of the ultra-relativistic laser peak are critical parameters. Accurate modeling of the leading edge-driven target pre-expansion is desired to strengthen the predictive power of associated computer simulations. The transition from an initial solid state to a plasma state, i.e., the breakdown of the solid, defines the starting point of the subsequent target pre-expansion. In this work, we report on the time-resolved observation of transient laser-induced breakdown (LIB) during the leading edge of high-intensity petawatt-class laser pulses with peak intensities of up to 5.7 × 10^21 W/cm^2 in interaction with dielectric cryogenic hydrogen jet targets. LIB occurs much earlier than what is typically expected following the concept of barrier suppression ionization. The observation is explained by comparing a characterization study of target
specific LIB thresholds with laser contrast measurements. The results demonstrate the relevance of the laser pulse duration dependence of LIB for high-intensity laser-solid interactions. We provide an effective approach to determine the onset of LIB and thereby the starting point of target pre-expansion in other laser-target systems.

Keywords: High intensity laser-plasma interactions; High-energy-density plasmas; Laser driven ion acceleration; Laser-plasma interactions; Plasma production and heating by laser beams; Femtosecond laser irradiation; Laser ablation; Optical plasma measurements; Photoionization; Ultrafast femtosecond pump probe

Publ.-Id: 35889

Characterization of Phage Display Derived Phage Clones and Peptides for the Recovery of Valuable Metal Ions from Low Concentrated Water Streams

Matys, S.; Schönberger, N.; Boelens, P.; Lederer, F.; Pollmann, K.

The long-term safeguarding of material resources is one of the current major economic challenges facing all industrialized nations. In particular, industrially relevant chemical elements, which are required for increasingly complex high technologies, are subject to a high supply risk [1]. For the Member States of the European Union, the Commission already compiled a list of supply-critical materials and an action plan for the implementation of a circular economy several years ago [2]. Low-resource countries such as Germany must focus more and more on the development of secondary raw material sources, effective recycling and new, environmentally friendly extraction methods. Biomolecules with metal-binding properties, especially short peptides, are particularly interesting in this respect, as they bind with high affinity and selectively, even at low concentrations [3]. We have used the commercially available bacteriophage libraries Ph.D.C7C and Ph.D.12 (New England Biolabs, Inc.) to isolate and identify specific binding peptides for several metal ions with different experimental set-ups. Here, we show how the specifically binding phage clones and isolated peptide motifs for nickel, cobalt, and gallium from Phage Surface Display (PSD) were characterized in terms of binding strength and complexation stoichiometry. For example, to specify the binding behavior, adsorption isotherms of two specifically binding phage clones - with the peptide motif CNAKHHPRC for nickel and CTQMLGQLC for cobalt - were determined on metal-loaded NTA agarose beads and compared with wild-type phage. Using different mathematical models, remarkable differences in the binding behavior of these three phage clones were found [4]. Thus, it was successfully demonstrated that the specific binding of these phage clones to chemically similar elements, such as cobalt and nickel can be verified by kinetic data. To corroborate these results, isothermal titration calorimetry studies were performed on pure synthetic peptides. The thermodynamic data also showed different binding properties for both ions. The applicability of this methodological approach was demonstrated in binding experiments with wastewater from the semiconductor industry. Selectively gallium-binding peptides have been shown to retain their binding ability after immobilization on polystyrene beads and are suitable for selective purification of complexly composed waters [5]. Our studies conducted so far indicate that PSD is generally a very suitable tool for the identification of specific binding peptides for metals in ionic form. Therefore, PSD can be considered as a platform to develop a green technology for the recovery of strategically important metals.

Keywords: phage surface display; metal recovery; peptides; adsorption isotherms; Isothermal Titration Calorimetry

  • Lecture (Conference)
    International Conference on Metal-Binding Peptides: Methodologies and Applications, 05.-08.07.2022, Nancy, Frankreich

Publ.-Id: 35888

Identification, characterization and optimization of lanthanide ion binding peptides for the recovery of rare earth elements

Claus, G.; Lederer, F.; Boelens, P.; Drobot, B.

Lanthanides are indispensable in times of modern technology and of extremely high relevance for the future due to their special properties. They provide essential components for high tech products and are used in environmental technology and the green tech industry, which focuses on sustainable products. The growing demand for these valuable metals and the existing high supply risk at the same time, as well as climate and environmental protection policies, are increasingly driving the search for alternative lanthanide extraction solutions. Therefore, a central issue is the recycling of lanthanides from end-of-life products as well as wastewater from agriculture, industry, hospitals and mining, for example. However, efficient recovery currently appears difficult to impossible, as their separation is associated with high costs – not least because of their chemically and physically very similar properties and their relatively low concentration in the product material and waste streams. For these reasons, there is intensive research into new recycling processes to enable a cost effective and environmentally friendly separation of these metals from electronic waste and wastewater, as well as conservation of and independence from primary resources.
Biocollectors and biohybrid separation platforms are promising novel recycling approaches, which are developed in our team of the Helmholtz Institute Freiberg for Resource Technology and the Institute for Resource Ecology of the Helmholtz-Zentrum Dresden-Rossendorf. The new approaches are composed of an appropriate carrier material and target specific peptides immobilized on it and are intended to extract the critical metals from electronic scrap, process waste streams or primary raw material mixtures in this way (Figure 1).
Phage surface display technology was applied for the identification and enrichment of those peptides that show an affinity for europium ions. In a competitive binding experiment, the selected peptide motifs were further reduced and non-specific sequences were discarded. The resulting best europium binding peptide variants were characterized by time-resolved laser fluorescence spectroscopy with respect to their affinity for europium ions and, if necessary, are optimized by site-directed mutagenesis. The four EF-hand peptides from the protein calmodulin will serve as a reference system.

Keywords: Phage surface display; biopanning; lanthanides; europium; specific peptides; biohybrid separation; REE recovery

  • Lecture (Conference)
    International Conference on Metal-Binding Peptides: Methodologies and Applications, 05.-08.07.2022, Nancy, Frankreich

Publ.-Id: 35887

BioKollekt – A novel peptide-based separation platform for electronic scrap

Lederer, F.; Claus, G.; Matys, S.; Boelens, P.

Circular economy, growing electronic waste piles and resource scarcity request for efficient ways for the recycling of electronic scrap. There are numerous recycling strategies known for precious metals. However, the recycling rates for a majority of elements are still low. The main reason for the lack of feasible recycling methods are the low costs for primary resources on the market. Other reasons are the high diversity and mostly low concentrations of valuable elements in electronic devices. Until now, biological recycling tools are not applied for resource recovery even though they could help to solve numerous challenges. Biological tools provide various potential recycling techniques, such as surface binding, mineral dissolving, transformation and metal complexation [1]. Using highly selective biomolecules like peptides delivers material selectivity in a complex mixture. Peptides are biodegradable, can be produced in high amounts chemically or biologically and are more robust compared to larger biomolecules [2].
The BioKollekt group develops a novel, peptide-based separation platform for certain elements that are part of electronic scrap (Fig.1). The peptides were identified using phage surface display (PSD). Target materials for motif identification were particles of the rare earth containing lamp phosphor powders LaPO4:Ce,Tb (LAP) and CeMgAl11O19:Tb (CAT). The peptides RCQYPLCS and ETKKCTTGPCKVVT were identified as selectively binding to LAP and CAT respectively [2, 3]. In the BioKollekt approach, these peptides are used to functionalize carrier materials such as magnetic carriers. Based on these functionalized carrier materials, appropriate e-waste particle separation processes were designed [4]. The major goal of our research is the development of an eco-friendly, efficient and sustainable recycling process for metals in electrical devices. Peptides, as relatively robust biomolecules with a giant variety of possible binding motifs, are the perfect key to interact with target metals. In this biogenic approach, we combine the target metal binding characteristics of the peptides with the separation process-supporting characteristic of the carrier. As a positive side effect, the design of the biocollector addresses its own reusability. That makes the process more sustainable in respect to resources and the positive impact on the ecological footprint of the recycled product, as well as more efficient in respect to costs and effort.

Keywords: circular economy; electronic waste; phage surface display; biocollector; magnetic separation

  • Lecture (Conference)
    International conference on Metal-binding peptides, 05.-08.07.2022, Nancy, Frankreich

Publ.-Id: 35886

"Elektroschrott-Recycling mit Viren" im ZDF Leschs Kosmos Beitrag "Der Schatz in der Mülltonne"

Lederer, F.; Boelens, P.; Vogel, M.; Bobeth, C.; Kießlich, T.; Bloß, C.; Wei, T.-S.; Drobot, B.

Im Leschs Kosmos Beitrag "Der Schatz in der Mülltonne" wurde der Einsatz von Biokollektoren der Nachwuchsforschergruppe BioKollekt filmisch dokumentiert. Ein Team von Wissenschaftlern des HIF, des IRE und des VKTA zeigten dabei die verschiedenen Schritte vom Phage Surface Display, über die Funktionalisierung von magnetischen Kügelchen bis zur Abtrennung des Lampenpulvers und dessen Nachweis über TRLFS. Arbeitsschritte, welche aufgrund der Größe der Materialien filmisch nicht passend dargestellt werden konnten, wurden durch einen Graphiker im Leschs Kosmos Team animiert.

Keywords: Bakteriophagen; Bioangeln; Lampenpulver; Next Generation Sequencing; Bioinformatik; High Gradient Magnetic Separator; TRLFS

  • Open Access Logo Communication & Media Relations
    Leschs Kosmos Fernsehdokumentationsbeitrag 06.09.2022


Publ.-Id: 35885

Wie Biologie beim Recycling hilft

Lederer, F.

Neuste biotechnologische Methoden nutzen Biolaugung, Biosorption und Bioflotation, um die eher klassisch ausgerichteten Industriezweige Bergbau und
Mülltrennung zu ergänzen. In der Abteilung Biotechnologie am Helmholtz Institut Freiberg für Ressourcentechnologie werden durch die Kombination von
Biotechnologie mit verschiedenen klassischen Wissenschaften neue Lösungen für bisher ungelöste Probleme und neue Abfallströme gefunden.

Keywords: Biologie; Recycling; Elektroschrott

  • Lecture (others)
    Tag der Wissenschaft, 29.06.2022, Radebeul, Deutschland

Publ.-Id: 35884

aflow++: a C++ framework for autonomous materials design

Oses, C.; Esters, M.; Hicks, D.; Divilov, S.; Eckert, H.; Friedrich, R.; Mehl, M. J.; Smolyanyuk, A.; Campilongo, X.; van Dewalle, A.; Schroers, J.; Kusne, A. G.; Takeuchi, I.; Zurek, E.; Buongiorno Nardelli, M.; Fornari, M.; Lederer, Y.; Levy, O.; Toher, C.; Curtarolo, S.

The realization of novel technological opportunities given by computational and autonomous materials design requires efficient and effective frameworks. For more than two decades, aflow++ (Automatic-Flow Framework for Materials Discovery) has provided an interconnected collection of algorithms and workflows to address this challenge. This article contains an overview of the software and some of its most heavily-used functionalities, including algorithmic details, standards, and examples. Key thrusts are highlighted: the calculation of structural, electronic, thermodynamic, and thermomechanical properties in addition to the modeling of complex materials, such as high-entropy ceramics and bulk metallic glasses. The aflow++ software prioritizes interoperability, minimizing the number of independent parameters and tolerances. It ensures consistency of results across property sets — facilitating machine learning studies. The software also features various validation schemes, offering real-time quality assurance for data generated in a high-throughput fashion. Altogether, these considerations contribute to the development of large and reliable materials databases that can ultimately deliver future materials systems.

Related publications


Publ.-Id: 35881 a web ecosystem of databases, software and tools

Esters, M.; Oses, C.; Divilov, S.; Eckert, H.; Friedrich, R.; Hicks, D.; Mehl, M. J.; Rose, F.; Smolyanyuk, A.; Calzolari, A.; Campilongo, X.; Toher, C.; Curtarolo, S.

To enable materials databases supporting computational and experimental research, it is critical to develop platforms that both facilitate access to the data and provide the tools used to generate/analyze it — all while considering the diversity of users’ experience levels and usage needs. The recently formulated FAIR principles (Findable, Accessible, Interoperable, and Reusable) establish a common framework to aid these efforts. This article describes, a web ecosystem developed to provide FAIR-compliant access to the AFLOW databases. Graphical and programmatic retrieval methods are offered, ensuring accessibility for all experience levels and data needs. goes beyond data-access by providing applications to important features of the AFLOW software [1], assisting users in their own calculations without the need to install the entire high-throughput framework. Outreach commitments to provide AFLOW tutorials and materials science education to a global and diverse audiences will also be presented.

Related publications


Publ.-Id: 35880

Data-Driven Research for the Discovery of Novel Two-Dimensional Materials

Friedrich, R.

Data-Driven Research for the Discovery of Novel Two-Dimensional Materials

Related publications

  • Invited lecture (Conferences)
    DFG CRC 1415 Young Investigator Symposium, 21.11.2022, Dresden, Deutschland

Publ.-Id: 35879

Data-Driven Design of Two-Dimensional Non-van der Waals Systems and Ionic Materials

Friedrich, R.

Data-Driven Design of Two-Dimensional Non-van der Waals Systems and Ionic Materials

Related publications

  • Invited lecture (Conferences)
    Seminar Theoretische Chemie TU Dresden, 19.04.2022, Dresden, Deutschland

Publ.-Id: 35878

Data-Driven Design of Two-Dimensional Non-van der Waals Materials and Cation Exchange in CdSe Nanoplatelets

Friedrich, R.; Ghorbani Asl, M.; Curtarolo, S.; Shamraienko, V.; Subakti, S.; Lubk, A.; Eychmüller, A.; Krasheninnikov, A.

Data-Driven Design of Two-Dimensional Non-van der Waals Materials and Cation Exchange in CdSe Nanoplatelets

Related publications

  • Poster
    Retreat of the DFG CRC1415, 15.06.2022, Lichtenwalde, Deutschland

Publ.-Id: 35877

Data-Driven Design of Two-Dimensional Non-van der Waals Materials

Friedrich, R.; Ghorbani-Asl, M.; Curtarolo, S.; Krasheninnikov, A. V.

Two-dimensional (2D) materials are traditionally associated with the sheets forming bulk layered compounds bonded by weak van der Waals (vdW) forces. The unexpected experimental realization of non-vdW 2D compounds, for which previously developed descriptors are not applicable, opened up a new direction in the research on 2D systems [1]. Here, we present our recent data-driven search for representatives of this novel materials class [2]. By screening the AFLOW database according to structural prototype information, 28 potentially synthesizable candidates are outlined. The oxidation state of the surface cations is found to regulate the exfoliation energy with low oxidation numbers giving rise to weak bonding – thus providing an enabling descriptor to obtain novel 2D materials. The candidates showcase a versatile spectrum of appealing electronic, optical and magnetic properties.

[1] A. Puthirath Balan et al., Nat. Nanotechnol. 13, 602 (2018).

[2] R. Friedrich et al., Nano Lett. 22, 989 (2022).

Related publications

  • Poster
    Psi-k Conference, 23.08.2022, Lausanne, Schweiz

Publ.-Id: 35875

Bioionflotation: Biotechnical approach for metal recovery from low concentrated waters

Chakankar, M. V.; Pollmann, K.; Rudolph, M.

Ion flotation is a well-known process for the separation or removal of metal ions at a low concentra-tion from aqueous solutions. The use of various flotation agents is well documented, yet there is a high demand for new flotation agents. The new ion flotation agents need to be highly selective, effi-cient, and environmentally friendly. Microbial biosurfactants with high surface activity and metal complexation ability are molecules of interest in this regard. The use of these biomolecules as flota-tion reagents in the ion flotation process can be termed as ‘bioionflotation’. This biotechnological approach for metal recovery from low concentrated waters is still dawning and more research is required to improve the selectivity and process efficiency. This study investigated the separation of gallium (Ga) from aqueous solutions using rhamnolipid biosurfactant as the flotation reagent. The systematic study showed the influence of metal ions on surface activity and foaming properties of the biosurfactant. Further effects of various operating parameters on the metal recovery and selec-tivity were studied. The flotation results of the mixed metal solutions (containing Ga and As at 1 mM concentration), showed nearly 60% and 3.5% of Ga and As recovery, respectively, at 0.85 mM rhamnolipid concentration at pH 6 and air flow rate of 40 ml/min. Further, the selectivity index for Ga over As was 17.2 for the studied system. These results provide insights on the parameters influ-encing the properties of flotation collectors and provide the basis for the development of the bioion-flotation process for effective and selective separation of metal ions from low concentrated waters. These results also indicate the role of biosurfactants as a promising green flotation reagent.

Keywords: biosurfactant; flotation reagent; gallium; rhamnolipid; ion flotation

  • Lecture (Conference)
    The 24th International Biohydrometallurgy Symposium 2022, 20.-23.11.2022, Perth, Australia

Publ.-Id: 35874

Data-Driven Design of Two-Dimensional Non-van der Waals Materials

Friedrich, R.; Ghorbani-Asl, M.; Curtarolo, S.; Krasheninnikov, A. V.

Two-dimensional (2D) materials are traditionally associated with the
sheets forming bulk layered compounds bonded by weak van der Waals
(vdW) forces. The weak inter-layer interaction leads to a natural structural
separation of the 2D subunits in the crystals, giving rise to the
possibility of mechanical and liquid-phase exfoliation as well as enabling
the formulation of exfoliability descriptors.
The unexpected experimental realization of non-vdW 2D compounds,
for which the previously formulated descriptors are not
applicable, opened up a new direction in the research on 2D systems
[1]. Here, we present our recent data-driven search for representatives
of this novel materials class [2]. By screening the AFLOW database
according to structural prototypes, 28 potentially synthesizable candidates
are outlined. The oxidation state of the surface cations is
found to regulate the exfoliation energy with low oxidation numbers
giving rise to weak bonding — thus providing an enabling descriptor
to obtain novel 2D materials. The candidates showcase a diverse
spectrum of appealing electronic, optical and magnetic features.
[1] A. Puthirath Balan et al., Nat. Nanotechnol. 13, 602 (2018).
[2] R. Friedrich et al., Nano Lett. 22, 989 (2022).

Related publications

  • Lecture (Conference)
    DPG Frühjahrestagung, 08.09.2022, Regensburg, Deutschland

Publ.-Id: 35873

Automated Enthalpy Corrections for Materials Design of Ionic Systems: AFLOW-CCE

Friedrich, R.; Esters, M.; Oses, C.; Ki, S.; Brenner, M. J.; Hicks, D.; Mehl, M. J.; Toher, C.; Curtarolo, S.

Materials databases such as AFLOW [1] leverage ab initio calculations
for autonomous materials design. The predictive power critically relies
on accurate formation enthalpies — quantifying the thermodynamic
stability of a system. For ionic materials such as oxides and nitrides,
standard DFT leads to errors of several hundred meV/atom [2,3].
We have recently developed the "coordination corrected enthalpies"
(CCE) method yielding highly accurate room temperature formation
enthalpies with mean absolute errors down to 27 meV/atom [3]. Here,
we introduce AFLOW-CCE [4] — our implementation of CCE into
the AFLOW framework. It provides a tool where users can input
a structure file and receive the CCE corrections, or even the CCE
formation enthalpies if pre-calculated LDA, PBE or SCAN values are
provided. The implementation features a command line tool, a web
interface, and a Python environment.
[1] S. Curtarolo et al., Comput. Mater. Sci. 58, 218 (2012).
[2] V. Stevanović et al., Phys. Rev. B 85, 115104 (2012).
[3] R. Friedrich et al., npj Comput. Mater. 5, 59 (2019).
[4] R. Friedrich et al., Phys. Rev. Mater. 5, 043803 (2021).

Related publications

  • Lecture (Conference)
    DPG Frühjahrestagung, 06.09.2022, Regensburg, Deutschland

Publ.-Id: 35872

Data-Driven Design of Two-Dimensional Non-van der Waals Materials

Friedrich, R.

Two-dimensional (2D) materials are traditionally associated with the sheets forming
bulk layered compounds bonded by weak van der Waals (vdW) forces with graphene
derived from bulk graphite being the most prominent example. The weak inter-layer
interaction leads to a natural structural separation of the 2D subunits in the crystals,
giving rise to the possibility of mechanical and liquid-phase exfoliation. The anisotropic
interaction also provided suitable structural criteria for the computational search for
such traditional 2D materials which predicted about 2000 exfoliable compounds [1].
However, the unexpected experimental realization of atomically thin sheets from
non-vdW bonded compounds, for which the previously formulated descriptors are
not applicable, recently opened up a new direction in the research on 2D materials
[2]. These non-vdW 2D compounds exhibit qualitatively new features due to the
unsaturated bonds at their surfaces. Here, we present our recent data-driven search
for representatives of this novel materials class [3]. By screening the AFLOW
database according to structural prototype information 28 new, potentially
synthesizable candidates are outlined. The oxidation state of the surface cations is
found to regulate the exfoliation energy with low oxidation numbers giving rise to
weak bonding – thus providing an enabling descriptor to obtain novel 2D materials.
The candidates showcase a versatile spectrum of appealing electronic, optical and
magnetic properties suggesting in particular spintronic applications.
[1] N. Mounet et al., Nat. Nanotechnol. 13, 246 (2018).
[2] A. Puthirath Balan et al., Nat. Nanotechnol. 13, 602 (2018).
[3] R. Friedrich et al. Nano Lett. 22, 989 (2022).

Related publications

  • Invited lecture (Conferences)
    CECAM Workshop Virtual Materials Design, 18.07.2022, Karlsruhe, Deutschland

Publ.-Id: 35871

Data-Driven Design of Two-Dimensional Non-van der Waals Materials

Friedrich, R.

Two-dimensional (2D) materials are traditionally associated with the sheets forming bulk layered
compounds bonded by weak van der Waals (vdW) forces with graphene derived from bulk
graphite being the most prominent example. The weak inter-layer interaction leads to a natural
structural separation of the 2D subunits in the crystals, giving rise to the possibility of mechanical
and liquid-phase exfoliation. The anisotropic interaction also provided suitable structural criteria
for the computational search for such traditional 2D materials which predicted about 2000
exfoliable compounds [1].
However, the unexpected experimental realization of atomically thin sheets from non-vdW
bonded compounds, for which the previously formulated descriptors are not applicable, recently
opened up a new direction in the research on 2D materials [2]. These non-vdW 2D compounds
exhibit qualitatively new features due to the unsaturated bonds at their surfaces. Here, we present
our recent data-driven search for representatives of this novel materials class [3]. By screening
the AFLOW database according to structural prototype information 28 new, potentially
synthesizable candidates are outlined. The oxidation state of the surface cations is found to
regulate the exfoliation energy with low oxidation numbers giving rise to weak bonding – thus
providing an enabling descriptor to obtain novel 2D materials. The candidates showcase a
versatile spectrum of appealing electronic, optical and magnetic properties suggesting in
particular spintronic applications.
[1] N. Mounet et al., Nat. Nanotechnol. 13, 246 (2018).
[2] A. Puthirath Balan et al., Nat. Nanotechnol. 13, 602 (2018).
[3] R. Friedrich et al., Nano Lett. 22, 989 (2022).
The authors thank the HZDR Computing Center, HLRS, Stuttgart, Germany, and TU Dresden
Cluster “Taurus” for generous grants of CPU time. R.F. acknowledges support from the
Alexander von Humboldt foundation under the Feodor Lynen research fellowship. A.V.K. thanks
the German Research Foundation (DFG) for the support through Project KR 4866/2-1 and the
collaborative research center “Chemistry of Synthetic 2D Materials” SFB-1415-417590517.

Related publications

  • Invited lecture (Conferences)
    CASUSCON, 13.07.2022, Breslau, Polen

Publ.-Id: 35870

Assessing fundamental parameters of magnetic properties of actinide containing samples

Fichter, S.; Gericke, R.; Duckworth, T.; Hong, B.; März, J.; Patzschke, M.; Schmidt, M.; Stumpf, T.; Kaden, P.

A study of acinide amidinate complexes is presented with an emphasis on magnetic properties. Main method is paramagnetic NMR spectroscopy highlighting pseudo-contact shifts and minor Fermi contact contributions to the observed NMR chemical shifts. As an outlook EPR spectroscopy and upcoming SQUID magnetometry is advertised.

Keywords: actinides; magnetic properties; NMR; EPR; SQUID; PCS; FCS; amidinate

  • Poster
    Actinides revisited 2022, 21.-23.09.2022, Dresden, Deutschland

Publ.-Id: 35869

Resource recovery: Innovative approaches with biomolecules

Lederer, F.

The Biotechnology Division at HIF uses diverse biomolecules for their application in resource recovery. This talk gives an overview on running projects and available biomolecules.

Keywords: peptides; organic acids; biotensides; siderophores

  • Invited lecture (Conferences) (Online presentation)
    Biokolloquium, 26.04.2022, Jena, Deutschland

Publ.-Id: 35868

Dynamic Gas Injection

Herrmann-Heber, R.; Reinecke, S.; Meier, M.; Hampel, U.

The previous investigations showed that the pulsed aeration leads to higher oxygen mass transfer rates in specific cases. In narrow aeration columns positive effects could be shown for higher pulsation frequencies whereas in the DN900 column these effects were only pre-sent for higher flow rates in low frequencies. Investigations of bubble size distributions showed that the bubble size is not the only factor leading to increased oxygen mass transfer rates and that the positive effects depend on the geometry and the liquid flow behavior in the reactor. Further experiments therefore are focused on fundamental investigation the liquid flow behavior during pulsed aeration. A new experimental setup was constructed to study these hydrodynamic effects in 2D to enable a better understand of the underlying effects.

Keywords: Dynamic aeration; wastewater treatment; gas injection; pulsation

  • Article, self-published (no contribution to HZDR-Annual report)
    Forschungszentrum Rossendorf 2022
    40 Seiten
    ISSN: 2191-8708, eISSN: 2191-8716


Publ.-Id: 35866

Choosing the right molar activity of an 123I-labeled irreversible inhibitor of transglutaminase 2 for quantitative expression profiling in tissues

Donat, C.; Laube, M.; Kopka, K.; Pietzsch, H.-J.; Pietzsch, J.; Löser, R.; Wodtke, R.


The Ca2+-dependent transamidase activity of transglutaminase 2 (TGase2) is tightly regulated in healthy cells but can be utilized by various cancer cells to support their survival and progression. Therefore, molecules targeting this enzyme are promising candidates for the functional characterization of TGase2 in tumors. Recently, we developed an 18F-labeled irreversible inhibitor and highlighted its potential as radiometric tool for the in vitro characterization of TGase2. Herein, we report on the kinetic characterization of a 123I-labeled Nε-acryloyllysine, [123I]1, and its use for quantifying the functional expression of TGase2 in tissues
[123I]1 was synthesized as recently presented [1]. The inhibitory potency of [123I]1 by means of its kinact/KI value was determined by a radio-TLC method using recombinant human TGase2. In vitro autoradiography was performed with fresh-frozen sections (12 µm) of several organs (heart, kidney, liver, spleen, and muscle), extracted from healthy NMRI nude mice. Binding experiments with [123I]1 were conducted at 0.7 MBq/mL in MOPS buffer at pH 7.4 containing 3 mM CaCl2 and 5 mM DTT. Non-specific binding was assessed in the presence of the TGase2 inhibitor Z006. Different molar activities (Am) were adjusted by the addition of compound 1.
[123I]1 was reliably obtained in high (radio)chemical purities of >99% and radiochemical yields of 79±6% (n=8). The Am was determined to be >6 TBq/µmol and the kinact/KI value to be 10,200 M-1s-1 (±1,000). Association (Figure 1) of n.c.a. [123I]1 at 37°C over 4 h to tissue sections furnished a high binding capacity and excellent ratios of total binding (TB) to non-specific binding (NSB). However, assessment of the quantitative TGase2 expression is limited as the inhibition rate at n.c.a. level is too low to achieve complete radioligand binding. Therefore, Am values of 70, 14, 7, and 1 GBq/µmol were adjusted to increase the association rates. A value of 7 GBq/µmol appeared to be optimal based on the extent of binding and the TB/NSB ratios. Higher Am values of 70 and 14 GBq/µmol still led to incomplete reaction and thus a lower apparent TGase2 concentration. In contrast, a Am value of 1 GBq/µmol resulted in extensive self-block, as indicated by an increased NSB (Figure 1). The highest TGase2 concentration has been observed in the heart and was lowest in muscle, with values of 1.3 and 0.2 pmol/mm3, respectively. Dissociation of [123I]1 under similar conditions proved the irreversible binding to TGase2 as only a minimal amount (<10%) of total bound radioligand dissociates over 4 h.
A detailed in vitro and ex vivo evaluation of the TGase2-inhibitor [123I]1 proved its applicability as radiometric tool for quantifying the functional expression of that enzyme. The observed low reaction rate of [123I]1 at high Am values was compensated by standard addition which might also have implications for the in vivo application of this compound.
The authors thank ROTOP Radiopharmacy for continuously providing [123I]iodide. Financial support by European Regional Development Fund (EFRE) for ML, HJP and RW is gratefully acknowledged.
[1] Laube et al, Nucl. Med. Biol., 2021, 96–97S, S79-S80,

  • Poster
    International Symposium of Radiopharmaceutical Sciences, 29.05.-02.06.2022, Nantes, Frankreich

Publ.-Id: 35865

The Impact of Nε-Acryloyllysine Piperazides on the Conformational Dynamics of Transglutaminase 2

Heerwig, A.; Kick, A.; Sommerfeld, P.; Eimermacher, S.; Hartung, F.; Laube, M.; Fischer, D.; Pietzsch, H.-J.; Pietzsch, J.; Löser, R.; Mertig, M.; Pietsch, M.; Wodtke, R.

In addition to classic functions of proteins such as acting as biocatalyst or binding partner, the conformational states of proteins and their remodeling upon stimulation needs to be considered. A prominent example that undergoes comprehensive conformational remodeling, is transglutaminase 2 (TGase 2), whose distinct conformational states are closely related to particular functions. Its involvement in various pathophysiological processes, including fibrosis and cancer, motivates the development of theranostic agents, particularly based on inhibitors that are directed towards the transamidase activity. In this context, the ability of such inhibitors to control the conformational dynamics of TGase 2 emerges as an important parameter, and methods to assess this property are in great demand. Herein, we describe the application of the switchSENSE® principle to detect conformational changes caused by three irreversibly binding Nε-acryloyllysine piperazides, which are suitable radiotracers candidates of TGase 2. The switchSENSE® technique is based on DNA levers actuated by alternating electric fields. These levers are immobilized on gold electrodes with one end, and at the other, distal end of the lever, the TGase 2 is covalently bound. A novel computational method is introduced for describing the resulting lever motion to quantify the extent of stimulated conformational TGase 2 changes. Moreover, as a complementary biophysical method, native polyacrylamide gel electrophoresis was performed under similar conditions to validate the results. Both methods prove the occurrence of an irreversible shift in the conformational equilibrium of TGase 2, caused by the binding of the three studied Nε-acryloyllysine piperazides.

Keywords: transamidase inhibitor; DNA nanolever; binding kinetics; conformational change

Publ.-Id: 35864

Strategies to Reduce Kidney Uptake of Radiolabeled Biomolecules

Wodtke, R.

Peptide receptor radionuclide therapy (PRRT) or radioligand therapy (RLT) represent valuable nuclear medical approaches for the treatment of tumors. It can lead to an unparalleled therapeutic success with [177Lu]Lu-DOTA-TATE1 and [177Lu]Lu-PSMA-6172 being the most striking examples, which were recently approved as Lutathera and Pluvicto, respectively. Besides stimulating the search for further targeted radiopharmaceuticals,3 there are ongoing efforts for optimizing PRRT and RLT apart from the tumor targeting itself. A non-negligible aspect for PRRT and RLT is radiation induced toxicity to healthy tissue, in particular bone marrow and kidneys but also other organs such as salivary glands in case of RLT with [177Lu]Lu-PSMA-617,4,5,6 that also limits the height of the applied activity amount. Due to the high hydrophilicity of somatostatin and PSMA ligands, their primary route of excretion proceeds via the kidney into the urine. This can be accompanied by a significant receptor-mediated reabsorption of the radiopharmaceuticals into the proximal tubular cells followed by lysosomal degradation, which ultimately result in a prolonged retention of the radiolabel and thus, a high dose exposure to the kidneys.7,8 Several nephroprotective strategies are pursued to reduce the tubular reabsorption during PRRT or RLT either by modifying the radiopharmaceutical itself or by co-injection of blocking substances.4,7 The talk will give an overview about the different strategies for reducing the renal uptake with a special emphasis on the targeting of renal brush border enzymes by the introduction of cleavable peptide linkers into targeted radiopharmaceuticals.


1. Strosberg et al. Phase 3 trial of 177Lu-Dotatate for midgut neuroendocrine tumors. N. Engl. J. Med. 2017, 376, 125-135.
2. Sartor et al. Lutetium-177-PSMA-617 for metastatic castration-resistant prostate cancer. N. Engl. J. Med. 2021, 385, 1091-1103.
3. Nicolas et al. New Developments in peptide receptor radionuclide therapy. J. Nucl. Med. 2019, 60, 167-171.
4. Geenen et al. Overcoming nephrotoxicity in peptide receptor radionuclide therapy using [177Lu]Lu-DOTA-TATE for the treatment of neuroendocrine tumours. Nucl. Med. Biol. 2021, 102-103, 1-11.
5. Gallyamov et al. Renal outcomes of radioligand therapy: experience of 177lutetium-prostate-specific membrane antigen therapy in metastatic castrate-resistant prostate cancer. 2020, 13, 1049-1055.
6. Kratochwil et al. EANM procedure guidelines for radionuclide therapy with 177Lu-labelled PSMA ligands (177-PSMA-RLT). 2019, 46, 2536-2544.
7. Vegt et al. Renal toxicity of radiolabeled peptides and antibody fragments: Mechanisms, impact on radionuclide therapy, and strategies for prevention. J. Nucl. Med. 2010, 51, 1049-1058.
8. Vegt et al. Renal uptake of different radiolabelled peptides is mediated by megalin: SPECT and biodistribution studies in megalin-deficient mice. Eur. J. Nucl. Med. Mol. Imaging 2011, 38, 623-632.

  • Invited lecture (Conferences)
    35th Annual Congress of the European Association of Nuclear Medicine (EANM), 15.-19.10.2022, Barcelona, Spanien

Publ.-Id: 35863

Implications of albumin binding for targeted radiopharmaceuticals

Wodtke, R.

Besides optimizing the vector molecule for its interaction toward the respective target protein, a modern tool in the field of radiopharmaceutical cancer therapy is the introduction of albumin-binding moieties to modulate the pharmacokinetic properties [1]. Basically, the approach aims at increasing the time-integral uptake of radioactivity in the tumor, which consequently increases the total radiation dose delivered to the tumor and thus, might improve the therapeutic outcome. In contrast, binding to albumin goes along with a prolonged blood circulation time and thus, a higher radiation dose to healthy tissues, in particular the red bone marrow. Vector molecules of various targets, including folate receptor, prostate specific membrane antigen (PSMA), and fibroblast activation protein (FAP), were equipped with albumin-binding moieties and promising preclinical studies were reported. However, the actual implications of binding to albumin appear less or even erroneously understood. In this context, the protracted tumor uptake is an important aspect, which originates from lowering the unbound fraction of the radioligand in the blood. Moreover, considering the free drug hypothesis [2], the usually observed gain in tumor uptake requires another tumor uptake mechanism of the albumin-bound radioligand to be operational and is not a result of the prolonged blood circulation time.
Based on our own data to albumin-binding radioligands of the somatostatin receptor subtype 2 (SST2) [3], the talk will give insight into the pharmacokinetic implications of albumin binding with a special focus on the relation of the binding affinity to albumin and the resulting biodistribution of the radioligand, which is also of importance for the radiation-induced toxicity to healthy tissues.


1. Brandt M et al.: Nucl. Med. Biol. 2019, 70: 46–52.
2. Smith D A, Di L, Kerns E H: Nat. Rev. Drug Discov. 2010, 9(12): 929–939.
3. Brandt F et al.: J. Med. Chem. 2022, 65(1): 710–733.

  • Invited lecture (Conferences)
    DPhG Annual Meeting 2022 ∙ “From Behring to Biotechnology – moving Pharmaceutical Sciences towards One Health”, 13.-16.09.2022, Marbug, Deutschland

Publ.-Id: 35862

Particle yield calculations for different target designs at Mu2e-II

Müller, S.

This publication contains configuration files for simulations using the FLUKA2021 radiation transport package for mu- and pi- yields for different production target designs for a possible Mu2e-II experiment at FNAL, US.

Keywords: FLUKA; MU2E-II


Publ.-Id: 35861

Experimentos em campos magnéticos pulsados: uma ferramenta poderosa para estudar materiais multicalóricos

Salazar Mejia, C.

As instalações de campo pulsado são conhecidas pelos altos campos magnéticos que podem produzir (até 100 Tesla). Por outro lado, para aplicações em refrigeração magnética, os campos magnéticos de até 2 T entram em questão. Portanto, a realização de experimentos com campos magnéticos pulsados para estudar materiais multicalóricos parece ser, pelo menos à primeira vista, supérfluo. No Dresden High Magnetic Field Laboratory, desenvolvemos a técnica para medir diretamente a variação de temperatura da amostra sob campos aplicados que podem ir além de 50 T. A curta duração do pulso (normalmente entre 10 a alguns 100 ms) proporciona boas condições adiabáticas durante o experimento permitindo a medição direta da variação adiabática de temperatura de um material, ΔTad, sem qualquer perda de calor. Além de medir o ΔTad de nossas amostras, mostramos que os campos magnéticos pulsados são uma ferramenta poderosa para estudar e caracterizar materiais multicalóricos. O regime de campos altos permite determinar, por exemplo, o valor de saturação do efeito magnetocalórico e sua máxima extensão em temperature ou podemos induzir a transição do material em uma ampla faixa de temperatura. Efeitos irreversíveis devido à histerese, dinâmica de transição ou a dependência do protocolo de medição do efeito magnetocalórico são geralmente estudados em detalhes em nossas medições. Além disso, a possibilidade de combinar diferentes técnicas e medir simultaneamente a magnetostricção, magnetização e variações de temperatura de uma amostra dá uma visão completa das propriedades do material. Em minha palestra, apresentarei a técnica para determinar diretament o efeito magnetocalórico em campos magnéticos pulsados e mostrarei alguns exemplos de ligas de Heusler.

  • Invited lecture (Conferences) (Online presentation)
    Workshop Brasileiro em Efeitos i-Calóricos, 30.-31.03.2022, online, Brazilia

Publ.-Id: 35860

The Use of Magnetic Shape Memory Alloys in Multicaloric Refrigeration Cycles

Gottschall, T.

Symposium FM
State-of-the-art Research and Applications of Shape Memory Alloys

  • Invited lecture (Conferences)
    Cimtec Congress 2022 - 9th Forum on New Materials, 25.-29.06.2022, Perugia, Italien

Publ.-Id: 35859

Magnetocaloric materials in high fields: room temperature towards cryogenic applications

Gottschall, T.

Virtual conference contribution by invitation

  • Invited lecture (Conferences) (Online presentation)
    IMRC 2022 - International Materials Research Congress, 17.08.2022, Cancun, Mexico

Publ.-Id: 35858

Study on multicaloric Heusler alloys in pulsed magnetic fields

Gottschall, T.

No short version available

  • Invited lecture (Conferences)
    Calorics 2022, 12.-14.09.2022, Cambridge, United Kingdom

Publ.-Id: 35857

Magnetische Kühlung: Von Raumtemperatur- hin zu kryogenen Anwendungen

Gottschall, T.

Zu diesem eingeladenen Vortrag auf der Calorics 2022 (Kälte-Klima-Tag 2022) in Wien
lag keine Kurzfassung vor.

  • Invited lecture (Conferences)
    Kälte-Klima-Tag 2022, 06.10.2022, Wien, Österreich

Publ.-Id: 35856

Dataset for neutronics benchmark of NuScale-like core

Fridman, E.

This data set supplements the neutronics benchmark of the NuScale-like core. The data set includes spreadsheets with material compositions and the reference Serpent Monte Carlo solution

Keywords: NuScale; SMR; benchmark; Serpent; Monte Carlo


Publ.-Id: 35855

Advanced characterization of materials in pulsed magnetic fields

Gottschall, T.

The multicaloric effect is described by a temperature or entropy change of a material triggered by external stimuli applied or removed simultaneously or sequentially. The prerequisite for this is a material exhibiting multiple ferroic states. However, direct measurements of the effect are rarely reported. Now, for this reason, we built a measurement device allowing to determine the adiabatic temperature change in pulsed magnetic fields and, simultaneously, under the influence of a uniaxial load. We selected the all-d-metal Heusler alloy Ni–Mn–Ti–Co for our first test because of its enhanced mechanical properties and enormous magneto- and elastocaloric effects. Ni–Mn–Ti–Co was exposed to pulsed magnetic fields up to 10 T and uniaxial stresses up to 80 MPa, and the corresponding adiabatic temperature changes were measured. With our new experimental tool, we are able to better understand multicaloric materials and determine their cross-coupling responses to different stimuli.

  • Invited lecture (Conferences)
    HI-Entropy final project meeting / Pre-Kick-off Meeting HyLICAL, 29.11.2022, Oslo, Norwegen

Publ.-Id: 35852

Stabilization mechanism of molecular orbital crystals in IrTe2

Ritschel, T.; Stahl, Q.; Kusch, M.; Trinckauf, J.; Garbarino, G.; Svitlyk, V.; Mezouar, M.; Yang, J.; Cheong, S.-W.; Geck, J.

Doped IrTe2 is considered a platform for topological superconductivity and therefore receives currently a lot of interest. In addition, the superconductivity in these materials exists in close vicinity to electronic order and the formation of molecular orbital crystals, which we explore here by means of high-pressure single crystal x-ray diffraction in combination with density functional theory. Our crystallographic refinements provide detailed information about the structural evolution as a function of applied pressure up to 42 GPa. Using this structural information for density functional theory calculations, we show that the local multicenter bonding in IrTe2 is driven by changes in the Ir-Te-Ir bond angle. When the electronic order sets in, this bond angle decreases drastically, leading to a stabilization of a multicenter molecular orbital bond. This unusual local mechanism of bond formation in an itinerant material provides a natural explanation for the different electronic orders in IrTe2. It further illustrates the strong coupling of the electrons with the lattice and is most likely relevant for the superconductivity in this material.

Publ.-Id: 35850

Hyperspectral Unmixing using Convolutional Autoencoder for Metal Detection in Lithium-Ion Battery Recycling Applications

Chouhan, S.; Rasti, B.; Ghamisi, P.; Lorenz, S.; Fuchs, M.; Gloaguen, R.

Recent advancements in hyperspectral imaging systems have opened up possibilities for identifying and distinguishing materials based on their spectral characteristics, as every material has its unique spectral signature. In our work, we present a novel approach for detecting and distinguishing copper and aluminum foils present in shredded lithium-ion batteries (LIBs) using convolutional autoencoder for hyperspectral unmixing. In hyperspectral applications, unmixing is a key procedure for estimating spectral signatures of pure materials (endmembers) as well as the corresponding fractional spatial extent (abundances) of endmembers in mixed pixels of hyperspectral images (HSIs). We perform hyperspectral unmixing on a real hyperspectral dataset using a convolutional autoencoder with sparse regularization. We evaluate the performance of the autoencoder framework using VNIR (visible and near-infrared) HSI data acquired with the Specim FX10 hyperspectral sensor. Our experimental unmixing results demonstrate that convolutional autoencoder showed a significant improvement in unmixing performance compared with competing unmixing methods. To the best of our knowledge, this work is the first to implement hyperspectral unmixing using autoencoder in LIB recycling, which is highly significant for automated sorting of valuable metals in LIB recycling industrial applications.

  • Contribution to proceedings
    Workshop on Hyperspectral Image and Signal Processing : Evolution in Remote Sensing, 13.-16.09.2022, Roma, Italia
    2022 12th Workshop on Hyperspectral Imaging and Signal Processing: Evolution in Remote Sensing (WHISPERS): IEEE Xplore
  • Lecture (Conference)
    Workshop on Hyperspectral Imaging and Signal Processing: Evolution in Remote Sensing (WHISPERS), 13.-16.06.2022, Roma, Italia

Publ.-Id: 35849

Developing an autonomous, task-distributed drone network for the mapping of remote and isolated targets

Lorenz, S.; Booysen, R.; Madriz Diaz, Y. C.; Thiele, S. T.; Kirsch, M.; Gloaguen, R.

Uncrewed aerial vehicles (UAVs), also referred to as drones, have become a major developing branch in the field of autonomous vehicles. Lightweight, flexible, and inexpensive, UAVs can offer individual solutions for a wide range of applications. Important assets are the fast turnaround times and high customizability of UAV platforms and their respective payloads. This targeted and adapted surveying allows us to map chemical and physical properties of complex or even inaccessible terrains. Regulatory and technical barriers, however, limit the product of take-off weight and endurance for civil and research use. Common compromises are light-weight systems with high ground coverage and small payloads (e.g., small, fixed-wing drones), and heavy-duty UAV (e.g., multi-copters) with shorter flight times. The latter in turn provide the opportunity to deploy heavier, highly technological equipment to gather more information on the depicted scene.
This trade-off causes a dilemma, in particular for drone-borne material mapping with spectral imaging sensors. Light-weight systems can achieve sufficient aerial coverage within a reasonable time, however, light-weight cameras are mostly limited to uncooled systems covering the visible and near-infrared range of the electromagnetic spectrum. Such sensors allow characterization only for a limited number of materials with often low confidence. The lack of subsurface information acquired with these sensors further limits the provided data value, especially in regions with extensive vegetation or soil coverage.
Systems analyzing subsurface geophysical properties or providing enhanced spectroscopic information (e.g., by extending the detection range towards longer wavelengths) are often heavier and/or require adapted drone design and flight planning. Using such systems to cover a full prospect area at the required detail is tedious. Slow flight speeds, repeated battery changes, and a tremendous amount of data to process cause often intolerable delays. Short turnaround times, however, are key in the respective application fields, as either environmental conditions or the mission itself may offer a limited time-window for data acquisition and initial result delivery. This is a major hurdle for many potential UAV applications such as greenfield mineral exploration, search & rescue, or leak/pollution detection, where targets of interest are often remote, small-scaled and of unknown exact location.
We present an innovative concept capable of performing rapid and reliable target characterization via a domain approach. The core idea is the development of a task-distributed drone network, combining the strengths of light-weight and heavy-duty systems. As high-detail data is only acquired where it matters, long flight-times and large volumes of superfluous data can be avoided from the start. This also reduces processing time, computational requirements, as well as the impact of the survey on the environment. As a first step, we demonstrate the challenges and opportunities provided by such multi-modal, drone-based mapping in the framework of mineral exploration. In several case studies, we also showcase the added value of integrating surface (spectral imaging) and subsurface (geophysical) data for better target characterization and give an outlook on autonomous and multi-drone data acquisition for a targeted and more efficient characterization.

  • Poster (Online presentation)
    Workshop on Hyperspectral Image and Signal Processing : Evolution in Remote Sensing (WHISPERS), 13.-16.09.2022, Roma, Italia

Publ.-Id: 35848

Drones for Remote and Autonomous Multi-sensor Mapping in Mineral Exploration

Lorenz, S.; Madriz Diaz, Y. C.; Booysen, R.; Thiele, S. T.; Kirsch, M.; Gloaguen, R.

Uncrewed aerial vehicles (UAVs), also known as drones, have become an important branch of development in the field of innovative exploration technology. Short turnaround times, the highly adaptable nature of drone platforms, and the growing variety of sensors that can be deployed are driving increased interest in implementing drone-based mapping into mineral exploration workflows. Drone-based adaptation of technologies previously applied in airborne or ground-based campaigns now enables rapid mapping of geologic targets in unprecedented detail. The ability to objectively map topography and surface mineral composition using imaging sensors (including RGB, multi- and hyperspectral cameras) and subsurface physical properties using geophysical sensors such as magnetics and radiometrics has shown to add impressive value to conventional mapping workflows.
Regulatory and technical barriers, however, often force a difficult trade-off between sensor payload and flight time on drone-based surveys. In an applicational field, where short turnaround times are key and targets of interest are remote and difficult to access, this often results in the use of light-weight sensors and single-sensor acquisitions.
In this contribution, we demonstrate the challenges and opportunities provided by multi-modal drone-based data in the framework of mineral exploration. In several case studies, we showcase the added value of integrating surface (spectral imaging) and subsurface (geophysical) data for better target characterization. We finally give an outlook on autonomous and multi-drone data acquisition for a targeted and more efficient characterization.

  • Lecture (Conference) (Online presentation)
    SEG 2022 - Minerals for our future, 27.-30.08.2022, Denver, USA

Publ.-Id: 35847

Multi-sensor drones for resource characterization

Lorenz, S.; Booysen, R.; Thiele, S. T.; Madriz Diaz, Y. C.; Kirsch, M.; Gloaguen, R.

Conventional geological mapping is limited by survey size, access, complex target geometries and public acceptance. We develop drone-based mapping platforms to mitigate these challenges.
Drones provide unique platforms for lightweight sensors, allowing:

  • Rapid deployment and objective data collection
  • Accurate 3D reconstruction using photogrammetry or Lidar sensors
  • Large coverage at high spatial (or temporal) resolution
  • Safe and practical access to complex relief (e.g., cliffs, mines)
  • Mapping of the surface and subsurface
  • Poster
    74. BHT - FREIBERGER UNIVERSITÄTSFORUM, 09.06.2022, Freiberg, Deutschland

Publ.-Id: 35846

From Drones to Hyperclouds - Trends in non-invasive and efficient exploration technologies

Lorenz, S.

The talk gives an insight into the current trends in non-invasive and efficient exploration technologies, showcasing actual ongoing research examples on drone-based mapping, hyperspectral imaging, outcrop-sensing and drill core analysis.

  • Invited lecture (Conferences) (Online presentation)
    RSES Student Conference 2022, 05.05.2022, Canberra, Australia

Publ.-Id: 35845

Joint recovery of graphite and lithium metal oxides from spent Li-ion batteries by froth flotation

Salces, A. M.; Rudolph, M.; Vanderbruggen, A.

Spent lithium-ion batteries (LIBs) contain critical raw materials that needs to be recirculated in the battery supply chain. In this work, the joint recovery of cathode and anode materials by froth flotation is proposed. Flotation is a water-intensive process, additionally, the water quality affects the flotation efficiency. In prospect of water-saving strategy, the process water characteristic and the effect of process water recirculation are also investigated. In this work, a pyrolyzed black mass(< 100 μm) is used, containing 43.8% C, 2.5% Li, and 39.4% Co, Ni and Mn as metal oxide. After flotation, a graphite recovery of 95% in the O/F product and a metal recovery of 80% in U/F product are achieved. The process water characterization reveals accumulation of Li ions to a potential value, up to 2600 mg/L.

Keywords: Froth flotation; Black mass; Lithium metal oxide; Anode graphite; Lithium-ion batteries; Recycling

  • Poster
    Helmholtz Energy Young Scientists Workshop 2022, 30.-31.05.2022, Maintal, Germany

Publ.-Id: 35844

Lithium-ion battery recycling: Recovery of lithium from process water through ion exchange

Salces, A. M.; Kelly, N.; Vanderbruggen, A.; Rudolph, M.

In Europe, an era of battery recycling is shaping new industries as spent lithium-ion batteries (LIBs) are considered, in addition to mining, as a potential source of battery raw materials with high prospect of environmental and economic incentives. Several recycling routes are being proposed combining hydrometallurgy and pyrometallurgy techniques and with emphasis on the mechanical pre-treatment (i.e., sorting, shredding, sieving) to pre-concentrate the LIBs component into a coarse metal fraction (Fe/plastics, Al, and Cu rich) and a fine electrode powder fraction (graphite and cathode active material - CAM). During LIB recycling, particularly in wet operations, specific LIB components such as Li and F easily dissolve into the water which results to material losses. For instance, immersion of an INR18650 battery in 1L water yielded a 100 mg/L Li and 140 mg/L F concentration. Moreover, the implementation of thermal treatment to liberate the electrode powder from the metal foils causes a carbothermic reduction of CAMs creating a more soluble Li compound that can be recovered by water leaching. Recently, froth flotation of pyrolyzed black mass aiming to separate graphite and CAM revealed a rather high concentration of Li in process water of 1,000 mg/L representing a 45% Li dissolution. A concentration of 2,600 mg/L Li was also reached during water recirculation in the flotation experiment. Hence, this work aims at the recovery of lithium from process water of battery recycling processes through the ion-exchange processes. Using commercial IX resins, the preliminary result shows a recovery of ~80% Li from flotation process water can be achieved after 15-min contact time. Precipitation experiments were also performed which produced a ~94-99% purity Li2CO3 powder.

Keywords: batteryrecycling; ionexchange; Lithium; flotationprocesswater; waterrecirculation

  • Lecture (Conference)
    International Battery Production Conference 2023, 07.-08.11.2022, Braunschweig, Germany

Publ.-Id: 35843

Hyperspectral outcrop characterization for structural mapping

Thiele, S. T.; Kirsch, M.; Lorenz, S.; Gloaguen, R.

Digital outcrop models have become a powerful tool for detailed structural mapping (Bemis et al., 2014), as they allow geological exposures to be characterized in unprecedented detail while simultaneously mitigating access limitations that hinder conventional mapping approaches. In this contribution we present an emerging workflow that fuses digital outcrop data with high resolution ground- and UAV- based hyperspectral imaging products to better discriminate key lithological units (marker horizons) and alteration trends (Lorenz et al., 2018; Kirsch et al., 2019). In some settings, hyperspectral data allows key mineral abundances to be mapped directly to create qualitative mineral maps (e.g., Thiele et al., 2022), however for structural mapping purposes the identification of distinctive marker horizons can be sufficient (e.g., Thiele et al., 2021). We illustrate this workflow with several examples from the Iberian Pyrite Belt (Spain), where the hyperspectral data helped constrain the geometry of deformed volcanic units hosting massive sulphide mineralization. Finally, a preliminary approach for combining (hyperspectral) digital outcrop data and 3-D interpolation algorithms to derive 3-D structural models of open-pit mines is discussed.

Acknowledgements: This work was supported by the European Union’s Horizon 2020 research and innovation programme under grant agreement No. 776487.

Bemis, S.P., Micklethwaite, S., Turner, S., James, M.R., Akciz, S., Thiele, S.T., & Ali Bangash, H. (2014): Ground-Based and UAV-Based Photogrammetry: A Multi-Scale, High-Resolution Mapping Tool for Structural Geology and Paleoseismology. Journal of Structural Geology 69 163–78.
Kirsch, M., Lorenz, S., Zimmermann, R., Andreani, L., Tusa, L., Pospiech, S., Jackisch, R., et al. (2019): Hyperspectral Outcrop Models for Palaeoseismic Studies. The Photogrammetric Record 34, no. 168 385–407.
Lorenz, S., Salehi, S., Kirsch, M., Zimmermann, R., Unger, G., Sørensen, E.V., & Gloaguen, R. (2018): Radiometric Correction and 3D Integration of Long-Range Ground-Based Hyperspectral Imagery for Mineral Exploration of Vertical Outcrops. Remote Sensing 10, no. 2:176.
Thiele, S.T., Lorenz, S., Kirsch, M., Acosta, I.C.C., Tusa, L., Hermann, E., Möckel, R., & Gloaguen, R. (2021): Multi-Scale, Multi-Sensor Data Integration for Automated 3-D Geological Mapping Using Hylite. Ore Geology Reviews 136.
Thiele, S.T., Bnoulkacem, Z., Lorenz, S., Bordenave, A., Menegoni, N., Madriz, Y., Dujoncquoy, E., Gloaguen, R., & Kenter, J. (2022): Mineralogical Mapping with Accurately Corrected Shortwave Infrared Hyperspectral Data Acquired Obliquely from UAVs. Remote Sensing 14, no. 1

  • Invited lecture (Conferences)
    European Society for Deformation Mechanisms, Rheology and Tectonics, 04.-07.07.2022, Catania, Italy

Publ.-Id: 35842

Hyperspectral mineral mapping with UAVs: challenges and opportunities for minerals exploration

Thiele, S. T.; Lorenz, S.; Booysen, R.; Madriz Diaz, Y. C.; Kirsch, M.; Gloaguen, R.

Uncrewed aerial vehicles (UAVs) have rapidly become integrated into the mining lifecycle, with applications in exploration, production and post-mining management. Although mostly used for photogrammetric surveying, a variety of additional sensors are increasingly being deployed. Of particular relevance to mineral exploration, these include geophysical instruments (e.g., magnetometers, radiometers) and imaging spectrometers (e.g., multi- and hyperspectral cameras), that can be deployed to rapidly and accurately map structure, lithology and alteration. Hyperspectral sensors are especially sensitive to subtle mineralogical changes that can guide exploration and mining operations, albeit in well exposed areas (e.g., cliffs, open-pit workings, mountains or coastal outcrops). In this contribution, we present an overview of our current workflow for collecting and correcting UAV hyperspectral data for geological applications, and outline some of the important caveats and challenges when deriving geometrically and spectrally corrected data in topographically complex environments. We emphasise the importance of three dimensional topographic data, collected using photogrammetric techniques, and highlight the potential of combined digital outcrop and hyperspectral remote sensing workflows. An open-source implementation of this workflow (hylite) is introduced, and current challenges identified. Specifically, we highlight the need for rapid, robust and easy to use tools for processing data in the field, to facilitate QAQC and optimised survey planning and targeting. Finally, we present several case studies that apply hyperspectral UAV data to advance exploration for primary and secondary raw materials.

  • Invited lecture (Conferences)
    SEG 2022 Conference: Minerals For Our Future, 27.-30.08.2022, Denver, United States of America

Publ.-Id: 35841

Remote Capture and Quantification of Diagenetic Products: An Outcrop Example from the Lower Jurassic in Morocco

Dujoncquoy, E.; Kenter, J.; Thiele, S. T.; Bourillot, R.; Champagne, J.; Ransinangu, A.; Grellier, J.; Bordenave, A.; Gloaguen, R.

Diagenetic modification of carbonate depositional systems is a dominant process changing their pore systems away from primary texture and responsible for their challenging multi-modal and multi-scale behavior. It is these pore system characteristics that control dynamic behavior across many scales from plug – to log – to reservoir scale. One common diagenetic product in many Middle East reservoirs is dolomite and is invoked to be associated with improved storage and excess permeability. Despite these observations, reliable spatial models of dolomite distribution are rare, especially at field or seismic scale. This paper documents how the dolomite distribution across an outcrop in Morocco was captured and validated using high resolution 3D photogrammetry combined with hyperspectral acquisition. It suggested that these, “remote” attributes can be combined and not only provide spatial rules but also point to scenarios for reconstruction of timing and process of dolomitization.

  • Contribution to proceedings
    Eighth EAGE Arabian Plate Core Workshop, 28.-30.11.2022, Dhahran, Saudi Arabia
    DOI: 10.3997/2214-4609.2022627018

Publ.-Id: 35838

Unravelling the Deformation of Paleoproterozoic Marbles and Zn-Pb Ore Bodies by Combining 3D-Photogeology and Hyperspectral Data (Black Angel Mine, Central West Greenland)

Guarnieri, P.; Thiele, S. T.; Baker, N.; Sørensen, E. V.; Kirsch, M.; Lorenz, S.; Rosa, D.; Unger, G.; Zimmermann, R.

The Black Angel Zn-Pb ore deposit is hosted in folded Paleoproterozoic marbles of the Mârmorilik Formation. It is exposed in the southern part of the steep and inaccessible alpine terrain of the Rinkian Orogen, in central West Greenland. Drill-core data integrated with 3D-photogeology and hyperspectral imagery of the rock face allow us to identify stratigraphic units and extract structural information that contains the geological setting of this important deposit. The integrated stratigraphy distinguishes chemical/mineralogical contrast within lithologies dominated by minerals that are difficult to distinguish with the naked eye, with a similar color of dolomitic and scapolite-rich marbles and calcitic, graphite-rich marbles. These results strengthen our understanding of the deformation style in the marbles and allow a subdivision between evaporite-carbonate platform facies and carbonate slope facies. Ore formation appears to have been mainly controlled by stratigraphy, with mineralizing fluids accumulating within permeable carbonate platform facies underneath carbonate slope facies and shales as cap rock. Later, folding and shearing were responsible for the remobilization and improvement of ore grades along the axial planes of shear folds. The contact between dolomitic scapolite-rich and calcitic graphite-rich marbles probably represents a direct stratigraphic marker, recognizable in the drill-cores, to be addressed for further 3D-modeling and exploration in this area.

Publ.-Id: 35837

Making space for magma fingers and sheet intrusions: the importance of intrusion tip velocities

Köpping, J.; Cruden, A. R.; Magee, C.; Thiele, S. T.; Slim, A.; Bunger, A.

Magma transport through the Earth’s crust is commonly described to occur through interconnected planar sheet intrusions such as dykes and sills, which form so called magma plumbing systems. Elongate intrusion geometries (i.e., magma fingers and segments), hereafter referred to as elements, may form during magma transport due to viscous and/or elastic instabilities at the propagating intrusion tip, and they are often observed at the outer margin of solidified sheet intrusions. Field observations, geophysical datasets, and analogue models further show that when elements grow in width, they can coalesce, indicating that planar sheet intrusions can form and grow by the amalgamation of individual elements. Previous studies suggest that the emplacement and growth of elements is accommodated by one dominating emplacement end-member process, namely: i) tensile-elastic fracturing, ii) shear failure, or iii) viscous deformation (e.g., host rock fluidisation). However, the interplay between individual end-member processes remains poorly understood. Here we present field observations of elongate magma fingers located at the SE margin of the Paleogene Shonkin Sag laccolith (Montana, USA) to assess how host rocks (Cretaceous Eagle Sandstone) deform to make space for the magma. We combine drone photogrammetry surveys with field mapping and microstructural analyses to describe and quantify host rock deformation in the vicinity of 37 magma fingers, and we conduct thermal modelling to further evaluate the conditions at which viscous deformation due to host rock fluidisation is feasible.

Our field observations show that all three proposed end-member processes accommodated the emplacement of magma fingers at the SE margin of the Shonkin Sag laccolith. Brittle deformation, shear failure, and folding of host rock mainly occurs in the compressional regime between two adjacent magma fingers, whereas host rock fluidisation and mobilisation is predominantly observed at the cross-sectional, lateral finger tips. Our photogrammetric analyses show that up to 40 % of the finger thickness is accommodated by elastic host rock uplift. Critically, this range of host rock deformation mechanisms is observed in one outcrop at metre scale, and in some cases associated with an individual magma finger. Thermal modelling of temperatures ahead of a propagating intrusion tip indicates that intrusion induced host rock fluidisation is only possible at low tip velocities of ≤ 10-5 m/s, which can vary depending on the emplacement depth, magma temperature, and the thermal diffusivity of the host rock.

Overall, we conclude that the emplacement of magma fingers at the outer margin of the Shonkin Sag laccolith was accommodated by a combination of elastic host rock uplift and both brittle and ductile host rock deformation. Based on our field observations and thermal modelling results, we suggest that intrusion tip velocities and the resulting strain rate are key parameters that control the dominating space-making mechanisms during magma emplacement. Due to the elongate geometry of elements and the resulting different strain rates at their lateral and frontal tips, we further propose that deformation mechanisms observed at lateral tips in cross sectional outcrops are likely decoupled from those at frontal tips such that they may not be equivalent.

Publ.-Id: 35836

Training data of a machine learning modeling framework for the air quality forecasts in the Pacific Northwest, USA.

Fan, K.; Dhammapala, R.; Harrington, K.; Lamb, B.; Lee, Y. H.

These files are the training data of a machine learning modeling framework for the air quality forecasts in the Pacific Northwest (PNW), USA. contains the AQS observations data of O3. contains the AQS data of PM2.5 using federal reference methods (FRM). contains the AQS data of PM2.5 using “FRM-like” methods. contains the archived WRF data for the AQS sites in the PNW.


Publ.-Id: 35834

Data publication: Improved calculations of mean ionization states with an average-atom model

Callow, T. J.
Researcher: Kraisler, Eli; Supervisor: Cangi, Attila

Data for our paper "Improved calculations of mean ionization states with an average-atom model" (arXiv)

For details about the data, please see the README file after unpacking the folder, and this GitHub repository.


Publ.-Id: 35832

CdSexS1−x Alloyed Nanoplatelets with Continuously Tunable Blue-Green Emission

Antanovich, A.; Yang, L.; Erwin, S. C.; Martín-García, B.; Hübner, R.; Steinbach, C.; Schwarz, D.; Gaponik, N.; Lesnyak, V.

Cadmium chalcogenide nanoplatelets (NPLs) are established as promising materials for a wide variety of optoelectronic applications due to their properties surpassing in many aspects their counterpart nanocrystals (NCs) with other shapes. Most of these features arise from strong quantum confinement in the direction of thickness which can be tuned with precision down to one monolayer. However, atomic smoothness of their basal planes and hence the ability to change the NPL thickness only in discrete steps prevent precise tuning of absorption and photoluminescence spectra unlike in the case of quantum dots. Preparation of alloyed NCs provides a potential solution to this problem, but it is complicated by the different reactivities of chalcogenide sources, which becomes even more restrictive in the case of NPLs because they are more sensitive to alterations of reaction conditions. In this work, we overcome this obstacle by employing highly reactive stearoyl sulfide and selenide as chalcogen sources, which enable straightforward variation of the NPL composition and thickness by changing the ratio of chalcogen precursors and reaction temperature, respectively. Alloyed CdSexS1−x NPLs
obtained exhibit tunable absorption and photoluminescence bands covering the blue-green region from 380 to 520 nm with bright band-edge emission and quantum yields of ∼30−50% due to their relatively small lateral size enabled by a much finer control of the lateral growth.

Related publications

Publ.-Id: 35829

Data to NEP paper

Wodtke, R.

Substratumsatzkurven NEP und PET Daten


Publ.-Id: 35827

FAP directed target modules are suitable for imaging and targeted radionuclide therapy of FAP-expressing solid tumours and their microenvironment

Neuber, C.; Rodrigues Loureiro, L. R.; Hoffmann, L.; Kubeil, M.; Arndt, C.; Mitwasi, N.; Kegler, A.; Bergmann, R.; Feldmann, A.; Bachmann, M.

Fibroblast activation protein (FAP), mainly expressed by cancer-associated fibroblasts (CAFs) in the tumour stroma, promotes tumour growth, metastasis, and immunosuppression and, therefore, has been studied as a target for cancer diagnosis and treatment. With regard to immunotherapy, the innovative modular universal CAR (UniCAR) platform developed by our group is one of the most promising approach due to the reduced risk for e.g. on-target/off-tumour toxicities and cytokine release syndrome. Thereby, chimeric antigen receptor (CAR) T-cells (UniCAR T cells) are exclusively activated in the presence of a target module (TM) that specifically establishes the crosslinking between target cells and UniCAR T-cells. FAP specific TMs are hypothesized to be not only immunotherapeutics with increased safety but in addition to be suitable as radionuclide-based theranostic agents.
For that, low molecular weight TMs that are rapidly eliminated allowing a specific and recurrent on/off switch of UniCAR T-cell activity via TM dosing were developed by fusion of the single-chain variable fragment (scFv) of an anti-human FAP mAb to the peptide epitope E5B9 that is recognized by the UniCAR T-cells. To ease the clinical TM administration at later stages of tumour therapy and for targeted radionuclide therapy, however, TMs with extended half-life may be advantageous. Therefore, anti-FAP TMs based on the human IgG4 Fc-domain, including a mutated version, were created. All TMs were tested (i) in vitro based on naturally and artificially overexpressing 2D and 3D models and (ii) in vivo by positron emission tomography (PET) and single-photon emission tomography (SPECT) in NMRI nude mice bearing both mock transfected and FAP overexpressing HT1080 tumor xenografts.
In vitro, all TMs were proven to specifically redirect UniCAR T-cells to FAP-expressing target cells. Moreover, FAP specific TMs could be conjugated to different chelators, e.g. Bispidines, NODAGA, and CHX-A-DTPA and, afterwards, radiolabelled with either Copper-64 or Lutetium-177. PET imaging with 64Cu radiolabelled anti-FAP IgG4 TMs revealed an excellent FAP specific tracer enrichment at the tumour site already 6h p.i. After 24 to 48h p.i. tumor SUVmean increased up to 20 with almost no background. SPECT imaging with 177Lu radiolabelled anti-FAP IgG4 TMs confirmed the high FAP-dependent tumour uptake and, thereby, offers possibility for targeted radionuclide therapy.
In conclusion, we designed novel FAP specific TMs with different molecular weight that can be used for immunotherapeutic approaches using UniCAR T-cells, diagnostic imaging, and targeted radionuclide therapy and, thereby, have the potential to improve cancer treatment allowing an individualized treatment of cancer patients with increased clinical safety.

Keywords: FAP; immunotherapy; PET imaging; SPECT imaging; targeted radionuclide therapy

  • Lecture (Conference)
    MoBi 2022, 15.-16.09.2022, Leipzig, Deutschland

Publ.-Id: 35826

Au4Mn: A localized ferromagnet with strong spin-orbit coupling, long-range ferromagnetic exchange, and high Curie temperature

He, Y.; Gersci, Z.; Zhang, R.; Kang, Y.; Skourski, Y.; Prendeville, L.; Larmour, O.; Besbas, J.; Felser, C.; Stamenov, P.; Coey, J. M. D.

Metallic Mn-based alloys with a nearest-neighbor Mn-Mn distance greater than 0.4 nm exhibit large, welllocalized magnetic moments. Here we investigate the magnetism of tetragonal Au4Mn with a Curie temperature of 385 K, where manganese has a spin moment of 4.1 μB and its orbital moment is quenched. Since 80% of the atoms are gold, the spin-orbit interaction is strong and Au4Mn exhibits uniaxial magnetocrystalline anisotropy with surface maze domains at room temperature. The magnetic hardness parameter of 1.0 is sufficient to maintain the magnetization along the c axis for a sample of any shape. Au also reduces the spin moment of Mn through 5d-3d orbital hybridization. An induced moment of 0.05 μB was found on Au under a pulsed field of 40 T. Density functional theory calculations indicate that the Mn-Mn exchange is mediated by spin-polarized gold 5d and 6p electrons. The distance dependence shows that it is ferromagnetic or zero for the first ten shells of Mn neighbors out to 1.041 nm (64 atoms), and very weak and oscillatory thereafter.


Publ.-Id: 35825

Cost effective production of siderophores by genetic manipulation for metal recovery

Singh, S.; Pollmann, K.; Schlömann, M.; Jain, R.

Secondary metabolites such as siderophores produced by microorganisms and plants bind not only Fe3+ but also commercially important elements such as Ga3+, Ge4+ and Ti4+. As numerous complexation studies suggest, siderophores are potential candidates for sustainable and environmentally friendly metal recovery technologies. However, the native and heterologous production of these siderophores is limited for many reasons, including iron inhibition, highly regulated production, the tendency to recycle siderophores and the simultaneous production of different siderophores. The most studied siderophore for metal recovery is desferrioxamine B, but since it is only produced chemically, its industrial application is limited. To solve this problem, we decided to use biological production in a natural host. In this project, we conducted experiments to optimise the media for the production of desferrioxamine B in a native host, Streptomyces pilosus, using minimal media and complex media. Streptomyces pilosus grows filamentous and therefore forms clusters mainly in minimal media, which poses a challenge for effective media optimisation. Initially, efforts were made to achieve homogeneous growth of Streptomyces pilosus, especially in minimal media without iron for desferrioxamine B production. When the growth of S. pilosus was switched from cluster to homogeneous growth, a phenotypic switch in siderophore production was observed. These studies will help to understand desferrioxamine B production in its native host. Furthermore, we look forward to optimize production of desferrioxamine in native host-Streptomyces pilosus.

  • Open Access Logo Poster
    Emerging applications of microbes (2nd Edition), 07.-08.12.2022, Leuven, Belgium


Publ.-Id: 35824

Localizing Mineral Dissolution Rate Spectra

Winardhi, C. W.; Da Assuncao Godinho, J. R.; Gutzmer, J.

Mineral dissolution is a dynamic process that involves reacting a surface with a fluid. Therefore, the kinetics of dissolution depends not only on the solution and the environment (concentration and temperature) but also on the mineral properties (reactive surface area, orientation and geometry). Several studies show that the dissolution rate is not a constant value but a spectra that depends on the reactivity of the different types of surface features. However, available experimental evidence comes either from observations from single surface (e.g. view from top) or from flow through in situ studies (where flow affects the observation). In this work the dissolution behavior of galena particles in deep eutectic solvent (DES) is shown using X-Ray Computed Tomography (CT). Two cases were evaluated: 1) only one surface of the particle was reactive and 2) the particle reacts from 5 different directions. The particle was leached in a stirred batch reactor to avoid the effect of directional flow. These are the first result showing the effect of large scale particle geometry in the dissolution rate spectra, which was used to developed a code to localize micron-scale evolution of the surface of a particle based on neighborhood of each point of the surface.

Keywords: X-Ray Computed Tomography; Mineral dissolution; Rate Spectra

  • Lecture (Conference) (Online presentation)
    Goldschmidt 2022, 07.-17.07.2022, Hybrid, Hawaii, Hybrid, USA

Publ.-Id: 35822

Standardized workflow to measure mineralogical composition and 3D geometry of particles

Gupta, S.; Da Assuncao Godinho, J. R.; Gotkowski, K.; Isensee, F.

Precise measurements of the mineralogical composition and 3D geometry of particles in mineral samples unlock the ability to systematically optimize ore processing procedures and thus paves the way for more efficient industrial ore processing and recycling of complex composite materials such as electronic waste. X-ray Computed tomography (CT) is a widely used method to acquire 3D images of such samples but so far lacks standardized methods to enable their interpretation. Here we introduce a new workflow to standardize the measurement of the 3D geometrical and mineralogical properties of particles. Importantly, our method is able to correct biases arising from partial volume imaging artefacts.

Specifically, our method consists of a combination of a deep neural algorithm known as nnU-Net [1], a state-of-the-art ready to use framework for segmentation of particles in the CT images, and MSPaCMAn [2], an automated method to extract precise mineralogical and geometrical properties on the particle level. We demonstrate that our method can be used out of the box to produce the particle segmentations independent of user biasness. These segmented images are used to calculate the 3D spatial properties of the particles including the mineralogical composition, surface liberation and a comprehensive list of geometrical properties. Results are validated using reference samples of known compositions. The proposed workflow is the first to enable a precise, unbiased and standardized semi-automated 3D analysis of particles using CT. The more comprehensive and standardized characterization is critical for the use of 3D particle properties in advanced ore processing techniques. Moreover, these 3D properties can be applied in the field of sedimentology for example to study the sediment transport and deposition.

Keywords: nnU-Net; MSPaCMAn; X-ray Computed Tomography; 3D characterisation

  • Lecture (Conference)
    Geoanalyses, 06.-12.08.2022, Freiberg, Germany

Publ.-Id: 35821

Standardized workflow to measure mineralogical composition, liberation and 3D geometry of particles using micro x-ray CT

Gupta, S.; Da Assuncao Godinho, J. R.; Gotkowski, K.; Isensee, F.

Mineralogical and 3D geometrical properties of particles affect their intrinsic separation behaviour. Artefacts from x-ray computed tomography (CT) images hinder the interpretation to determine the mineralogical and 3D geometrical information of the particles. Here we introduce a new workflow, a combination of a deep neural algorithm known as nnU-Net [1] and MSPaCMAn [2]. The workflow accounts for the partial volume artefacts in CT images. The 3D properties and the mineralogical composition of the particles are derived from the mask of the particles and individual particle histograms. The new workflow will unlock the ability to standardize and automate the mineral phase classification and quantification, determining liberation and calculation of 3D properties of the particles. This will pave the way to optimize the separation processes by finding the link between 3D properties, mineralogy and intrinsic separation properties at the particle level.

Keywords: X-ray Computed Tomography; 3D particle characterisation; Particle technology; MSPaCMAn; nnU-net

  • Lecture (Conference)
    Process Mineralogy, 02.-04.11.2022, Sitges, Spain

Publ.-Id: 35820

Use cases and tools in HMC Hub Energy

Süß, W.; Schweikert, J.; Stucky, K.-U.; Koubaa, M. A.; Steinmeier, L.; Ballani, F.

Five Helmholtz Centers are participating in the Research Field Energy, three of them are directly contributing to Hub Energy. To be well prepared for their supporting tasks in establishing a FAIR data ecosystem within the energy research community at Helmholtz, the team members of Hub Energy study relevant use cases and develop software tools in close cooperation with FAIR Data Commons. This poster presents four examples for this work: A photovoltaic system requires ontology development and data models based on standards like IEC 61850 or SensorML as well as on FAIR Digital Objects (FDO). In another use case, RO-Crates are automatically generated for data of the KIT Campus North energy and water consumption. The aim is to study methods for a detailed metadata desciption in data publication processes. In the field of software development, an FDO browser offers cascading search for metadata and application data entities and a metadata editor supports users in creating and editing schemas and instances as well. The presented activities foster close contact between Hub Energy and Helmholtz energy researchers and, thus, essentially support the formation of a FAIR energy data management. Use cases feed technical details into the Hub's energy knowledge pool and they are also a nearly perfect training programme for the Hub personnel. In doing the presented software development work, deep insights into energy data landscapes and an improved sense for user requirements are induced, even if in the end more elaborated and harmonized solutions from FAIR Data Commons may be adopted.

Keywords: FAIR Digital Objects; Photovoltaics Ontology; RO-Crates

  • Open Access Logo Poster (Online presentation)
    Helmholtz Metadata Collaboration - Conference 2022, 05.-06.10.2022, Kiel, Deutschland
    DOI: 10.5281/zenodo.7180896

Publ.-Id: 35819

Parallel Algorithm for Connected-Component Analysis using CUDA

Windisch, D.; Kaever, C.; Juckeland, G.; Bieberle, A.

Connected-component analysis (CCA) is a central part of many image processing applications. To process image data at ever increasing image resolutions and frame rates, parallel CCA 2
algorithms are essential. Such algorithms targeting GPUs typically store the extracted features in arrays large enough to potentially hold the maximum possible number of objects for the given image size. Transferring these large arrays to the host requires large portions of the overall execution time. Therefore, we propose an algorithm which uses a CUDA kernel to merge trees of connected component feature structs. During the tree merging, various connected-component properties, such as total area, centroid and bounding box, are extracted and accumulated. The tree structure then enables us to only transfer features of valid objects to the host for further processing or storing. Our benchmarks show that this implementation drastically reduces memory transfer volume for processing results on the host whilst maintaining similar performance to state-of-the-art CCA algorithms.

Keywords: connected-component analysis; image stream processing; parallel computing; CUDA

Publ.-Id: 35817

Antiskyrmions and their electrical footprint in crystalline mesoscale structures of Mn1.4PtSn

Winter, M.; Trindade Goncalves, F. J.; Soldatov, I.; He, Y.; Zuniga Cespedes, B. E.; Milde, P.; Lenz, K.; Hamann, S.; Uhlarz, M.; Vir, P.; König, M.; Moll, P. J. W.; Schlitz, R.; Goennenwein, S. T. B.; Eng, L. M.; Schäfer, R.; Wosnitza, J.; Felser, C.; Gayles, J.; Helm, T.

Skyrmionic materials hold the potential for future information technologies, such as racetrack memories. Key to that advancement are systems that exhibit high tunability and scalability, with stored information being easy to read and write by means of all-electrical techniques. Topological magnetic excitations such as skyrmions and antiskyrmions, give rise to a characteristic topological Hall effect. However, the electrical detection of antiskyrmions, in both thin films and bulk samples has been challenging to date. Here, we apply magneto-optical microscopy combined with electrical transport to explore the antiskyrmion phase as it emerges in crystalline mesoscale structures of the Heusler magnet Mn1.4PtSn. We reveal the Hall signature of antiskyrmions in line with our theoretical model, comprising anomalous and topological components. We examine its dependence on the vertical device thickness, field orientation, and temperature. Our atomistic simulations and experimental anisotropy studies demonstrate the link between antiskyrmions and a complex magnetism that consists of competing ferromagnetic, antiferromagnetic, and chiral exchange interactions, not captured by micromagnetic simulations.

Related publications


Publ.-Id: 35816

Investigation of aerosol particle separation by a rising bubble

Maestri, R.; Hampel, U.; Lecrivain, G.

The separation of aerosol particles by a moving gas-liquid fluidic interface is central to a wide variety of industrial and natural applications, among which stand out air purification systems and precipitation scavenging. The particle size significantly affects the separation rate. The diffusion of particles in the nanometer range is largely dominated by molecular diffusion. In this regime, predictive models accurately estimate the separation rates. Model inaccuracy increases, however, significantly when the particle size ranges from 0.1 μm to 2.5 μm. In this impaction-dominated regime, the complex interplay between the flow dynamics on both sides of the fluidic interface and the particle inertia makes it difficult to develop suitable models.
In this work, the preliminary work on the the bubble shape and the numerical simulation is presented, besides indication of relevant investigations in the particle separation on rising bubbles.

Keywords: Particle separation; Taylor bubble; CFD; Experimental fluid dynamics

  • Poster
    1st CORAERO PhD School, 07.-09.11.2022, München, Deutschland

Publ.-Id: 35815

The Heisenberg-Wigner formalism for transverse fields

Kohlfürst, C.

We discuss the Heisenberg-Wigner phase-space formalism in quantum electrodynamics as well as scalar quantum electrodynamics with respect to transverse fields. In regard to the special characteristics of such field types we derive modified transport equations such that particle momenta perpendicular to the propagation direction of the waves show up as external parameters only. In case of spatially oscillating fields we further demonstrate how to transform momentum derivative operators of infinite order into simple coupling terms.

Keywords: Strong-Field Quantum Electrodynamics; Electron-Positron Pair Production

Publ.-Id: 35814

Quantum-Accurate Multiscale Modeling of Shock Hugoniots, Ramp Compression Paths, Structural and Magnetic Phase Transitions, and Transport Properties in Highly Compressed Metals

Wood, M.; Nikolov, S.; Rohskopf, A.; Desjarlais, M.; Cangi, A.; Tranchida, J.

Fully characterizing high energy density (HED) phenomena using pulsed power facilities (Z machine) and coherent light sources is possible only with complementary numerical modeling for design, diagnostic development, and data interpretation. The exercise of creating numerical tests, that match experimental conditions, builds critical insight that is crucial for the development of a strong fundamental understanding of the physics behind HED phenomena and for the design of next generation pulsed power facilities. The persistence of electron correlation in HED materials arising from Coulomb interactions and the Pauli exclusion principle is one of the greatest challenges for accurate numerical modeling and has hitherto impeded our ability to model HED phenomena across multiple length and time scales at sufficient accuracy. An exemplar is a ferromagnetic material like iron, while familiar and widely used, we lack a simulation capability to characterize the interplay of structure and magnetic effects that govern material strength, kinetics of phase transitions and other transport properties. Herein we construct and demonstrate the Molecular-Spin Dynamics (MSD) simulation capability for iron from ambient to earth core conditions, all software advances are open source and presently available for broad usage. These methods are multi-scale in nature, direct comparisons between high fidelity density functional theory (DFT) and linear-scaling MSD simulations is done throughout this work, with advancements made to MSD allowing for electronic structure changes being reflected in classical dynamics. Main takeaways for the project include insight into the role of magnetic spins on mechanical properties and thermal conductivity, development of accurate interatomic potentials paired with spin Hamiltonians, and characterization of the high pressure melt boundary that is of critical importance to planetary modeling efforts.

Keywords: Materials science; Phase transitions; Density functional theory; Molecular dynamics; Machine learning

  • Open Access Logo Contribution to external collection
    in: U.S. Department of Energy Office of Scientific and Technical Information, Technical Reports, United States: U.S. Department of Energy Office, 2022
    DOI: 10.2172/1898251

Publ.-Id: 35812

A comparative study on heterogeneity of clay rocks using pore‐scale diffusion simulations and experiments

Yuan, T.; Yang, Y.; Ait-Mouheb, N.; Deissmann, G.; Fischer, C.; Stumpf, T.; Bosbach, D.

Accurate modeling and simulation of radionuclide migration in clay rocks such as the Opalinus Clay play a key role in the safety assessment of deep geological repositories for nuclear wastes. At the continuum scale, the representative elementary volume (REV) is a fundamental constraint to quantify the effective diffusivity, which is a key parameter in reactive transport (RT) models. Therefore, an accurate estimation of the REV is essential for a meaningful continuum-scale RT simulation in heterogeneous clay rocks. This study presents a comprehensive analysis of the heterogeneities of porosity and effective diffusivity in clay rocks by using the classical sampling theory and pore-scale simulations. First, in this study, the two-dimensional representative elementary area (REA) is correlated with the REV for porosity via a characteristic length. Next, it is shown that the REV for diffusivity is larger than the REV for porosity. Moreover, these two REVs can be correlated using Archie’s law. In such a way, the REV for diffusivity can be determined by the developed correlations through analyzing two-dimensional microstructures, thus significantly reducing the computational cost. Finally, the applicability of our approach for clay rocks is validated by experimental data on the diffusion of tritiated water in the heterogeneous sandy facies of Opalinus Clay. From both the experimental data and the modeling prediction, the REV for diffusivity in the sandy facies of Opalinus Clay is in the order of cubic centimeters. This study provides critical insights into the diffusion in heterogeneous clay rocks towards an enhanced predictability of radionuclide migration.

  • Open Access Logo Journal of Geophysical Research - Solid Earth 127(2022), e2022JB025428
    Online First (2022) DOI: 10.1029/2022JB025428

Publ.-Id: 35811

Total Bound Nitrogen Analysis for the Quantification of Immobilized Peptides on Dynabeads

Boelens, P.; Schöne, S.; Weiß, S.; Lederer, F.

According to the most recent listing reported by the European Commission, rare-earth elements (REEs) are the critical raw materials with the highest supply risk, whereas their recycling rates remain very low in the European Union [1]. End-of-life fluorescent lamps are a promising secondary source of REEs, but their recycling requires innovative separation processes [2,3]. By using phage surface display, Lederer and co-workers identified selectively surface-binding peptides that specifically bind to fluorescent lamp phosphors [4]. In a following study, Schrader et al. immobilized these peptides on coated well plates to investigate their binding to various REE phosphors [5]. The immobilization was facilitated by an activation with benzotriazole-1-yl-oxytripyrrolidinophosphonium-hexafluorophosphate (PyBOP) in the aprotic solvent N-Methyl-2-pyrrolidone (NMP) in the presence of the sterically hindered base diisopropylethylamine (DiPEA), a coupling reaction commonly used for chemical peptide synthesis. Recently, we investigated the immobilization method presented by Schrader et al. for the functionalization of Dynabeads [6]. Dynabeads are highly spherical and monodisperse composite magnetic beads, consisting of superparamagnetic iron oxide nanoparticles dispersed in a polystyrene matrix. They are commercially available with various surface coatings. The functionalization of amine coated Dynabeads with phosphor binding peptides, immobilized with the coupling reaction described above, did not change the Dynabeads’ zeta potential and had no significant effect on the interaction with REE phosphors [6]. On the other hand, we found that the immobilization onto carboxylic acid coated Dynabeads changed the Dynabeads’ zeta potential and isoelectric point.
We also observed that this immobilization had a detrimental effect on the interaction of the beads with the targeted phosphor particles and suggested that this may be an indication of polymerization of the peptides on the Dynabeads’ surfaces. In this work, we present a quantitative analysis of the total bound nitrogen (TNb) for the quantification of the immobilized peptides on the Dynabeads.

1. European Commission, Study on the EU’s list of Critical Raw Materials - Final Report (2020).
2. Patil, A.B., Paetzel, V., Struis, R.P.W.J., Ludwig, C. Separations 9 (2022),
3. Binnemans, K., Jones, P. Journal of Rare Earths 32, 195-200 (2014),
4. Lederer, F., Curtis, S., Bachmann, S., Dunbar, S., MacGillivray, R. Biotechnol. Bioeng. 114, (2016),
5. Schrader, M., Bobeth, C., Lederer, F. ACS Omega XXXX, (2021),
6. Boelens, P., Bobeth, C., Hinman, N., Weiss, S., Zhou, S., Vogel, M., Drobot, B., Azzam, S.S.A., Pollmann, K., Lederer, F. J. Magn. Magn. Mater. 169956 (2022),

  • Contribution to proceedings
    36th European Peptide Symposium, 28.08.-02.09.2022, Sitges, Spain
    Proceedings of the 36th European and the 12th International Peptide Symposium, 979-8-9872140-0-8
    DOI: 10.17952/36EPS.2022.130

Publ.-Id: 35810

Label-efficient Machine Learning for Diagnosing Urinary Tract Infection (UTI) in Urine Microscopy

De, T.; Liou, N.; Horsley, H.; Yakimovich, A.

Urinary tract infections (UTI) belong to the most common clinically relevant bacterial infections. 1 in 3 women worldwide will have at least one UTI by 24 years of age and 40 - 50% of women will experience one UTI during their lifetime with 44% experiencing recurrences. In this project, using a clinical dataset of brightfield microscopy of patients’ urine with few annotated samples,
we aim to develop a diagnostic phenotype quantification workflow using label-efficient machine learning (ML) approaches. There are several challenges to the clinical dataset at hand. Firstly, in the absence of specific labeling for phenotype-relevant objects in the micrographs ground truth is ambiguous. Secondly, obtaining manual annotations is laborious and requires highly-skilled annotators. Thirdly, the variation in scale and shape of a particular type of phenotype-relevant object is challenging for instance segmentation.

Keywords: urinary tract infection; clinical dataset; microscopy; label-efficient machine learning; ambiguous ground truth; phenotype quantification

  • Poster
    IDESSAI 2022, 29.08.2022, Saarland, Germany
  • Poster
    Big data analytical methods for complex systems, 06.10.2022, Wroclaw, Poland

Publ.-Id: 35808

Towards digital twins of distillation columns

Wiedemann, P.

Distillation is the most frequently used thermal separation process and accounts for a remarkable share of the global energy consumption. Therefore, design of distillation columns needs to target highly efficient operation. The present contribution describes current achievements of modeling and predicting the complex two-phase flow in tray columns, which strongly affects the heat and mass transfer processes and thus the separation efficiency. The strategy for creating a digital twin is based on combining a morphology adaptive multifield two-fluid model with reasonable abstraction of the vapor injection through fixed and push valves. Validation is carried out against experimental data of threedimensional phase distribution around single valves. In a second stage a pre-processing tool was developed to automatically set up simulation cases for industrial-scale applications. The simulations will be compared against phase fraction and velocity measurements of a conductivity sensor array that was applied in a large-scale column mockup.

Keywords: distillation; CFD; digital twin

  • Invited lecture (Conferences)
    2nd Workshop of the topic RESOURCE AND ENERGY EFFICIENCY, 07.-08.12.2022, Dresden, Deutschland

Publ.-Id: 35807

Data 4 paper: 3D quantitative mineral characterization of particles using X-ray computed tomography

Da Assuncao Godinho, J. R.

Grey-scale data for the two particulate samples: AllSizes (every particles <1 mm) and >710 (particle sizes 0.71-1 mm).

710 Grey is 16 bit

AllSizes Grey is 8bit

AllSizes Particles is binary

Keywords: X-ray computed tomography; mineralogy; MSPaCMAn; Quantification; Classification; 3d image


Publ.-Id: 35806

3D particle characterization. Can we do it and are we ready for it?

Da Assuncao Godinho, J. R.

Several ore materials were characterized by 2D mineral liberation analysis (MLA), by X-ray computed tomography (CT) and by other standard bulk techniques like X-ray diffraction (XRD) and laser scattering. A comparison of the different properties show that particle properties measured with CT were often different from the other techniques. This is interpreted not as a failure of CT but as a natural consequence of it’s strengths and limitations relative to the other techniques. This raises important questions, how can CT be validated relative to standardized techniques in order to be more broadly applied for particle characterization? Which 3D properties from CT can we trust? And how can those 3D properties be used to new discoveries in process mineralogy? These questions will be answered in light of specific case studies analysed using a new automated and standardized workflow for 3D particle analysis.

  • Lecture (Conference)
    Process Mineralogy 2022, 31.10.-04.11.2022, Barcelona, Spain

Publ.-Id: 35804

HapkeCNN: Blind Nonlinear Unmixing for Intimate Mixtures Using Hapke Model and Convolutional Neural Network

Rasti, B.; Koirala, B.; Scheunders, P.

This article proposes a blind nonlinear unmixing technique for intimate mixtures using the Hapke model and convolutional neural networks (HapkeCNN). We use the Hapke model and a fully convolutional encoder–decoder deep network for the nonlinear unmixing. Additionally, we propose a novel loss function that includes three terms; 1) a quadratic term based on the Hapke model, that captures the nonlinearity; 2) the reconstruction error of the reflectances, to ensure the fidelity of the reconstructed reflectance; and 3) a minimum volume total variation (TV) term that exploits the geometrical information to estimate the endmembers in the absence of pure pixels in the hyperspectral data. The proposed method is evaluated using two simulated and two real datasets. We compare the results of endmember and abundance estimation with a number of nonlinear, and projection-based linear unmixing techniques. The experimental results confirm that HapkeCNN considerably outperforms the state-of-the-art nonlinear approaches. The proposed method was implemented in Python (3.9) using PyTorch as the platform for the deep network and is available at: .

Publ.-Id: 35797

Multiphase flow imaging for process engineering

Hampel, U.

Multiphase flows are to be found in many production processes in the process industry. Examples are bubble column reactors, distillation columns, fluidized beds and many more. Measuring process parameters in such systems is very difficult because most sensors are disturbed in their fundamental measuring principles by the presence of particles and interfaces. Especially in fundamental fluid mechanics science, there is a growing need for imaging techniques for studying multiphase flows. There, the derivation of so-called CFD-grade data from fluid dynamics experiments requires imaging techniques with high spatial resolution, non-intrusiveness and ability to deal with the opacity of multiphase mixtures, walls and inserts in process vessels and their mock-ups. The presentation will give an overview of the state of the art of selected tomographic imaging techniques and discuss their application in solving process engineering problems.

Keywords: multiphase flow; imaging techniques; computed tomography; process engineering

  • Lecture (others)
    University of Kuopio Tomography Seminar, 20.12.2022, Kuopio, Finnland

Publ.-Id: 35795

Bioleaching of valuable and hazardous metal(loid)s from sulfidic mine waste by halophilic sulfur-oxidizing bacteria: a novel bioleaching approach

Opara, C. B.; Kutschke, S.; Pollmann, K.

Mine waste is a large waste stream and typically contains significant amounts of metal(loid)s, which can pose environmental risks, especially when poorly managed. Reprocessing of mine waste can offer both economic and environmental benefits by contributing to the ever-growing global demands for valuable metals, as well as reducing the environmental risks associated with mine waste. Bioleaching is a global biotechnology that exploits the abilities of some microorganisms to catalyze the oxidative dissolution of sulfidic minerals, thereby expediting the extraction of metal(loid)s. Chemolithoautotrophic acidophilic microorganisms have been the focus of bioleaching studies for many decades and can effectively catalyze the solubilization of metals from ores or waste materials. However, bioleaching with acidophilic organisms is performed at low pH (pH ≤ 2), which could lead to the acidification of the environment. In addition, the tolerance of many acidophilic microorganisms to high chloride concentrations is limited, therefore freshwater is mainly used. There is a growing interest in the use of seawater for leaching purposes, especially in regions with less access to fresh water. Hence, this study investigated the bioleaching potentials of four halophilic (marine), moderately-halophilic sulfur-oxidizing bacteria: Thiomicrospira cyclica, Thiohalobacter thiocyanaticus, Thioclava electrotropha and Thioclava pacifica in shake flasks at room temperature. Results revealed T. electrotropha and T. pacifica as the most promising for bioleaching. In comparison to an acidophilic consortium which leached 95% Co, 0% Pb, 85% Zn, 80% As, 100% Cd, and 55% Mn from a sulfidic mine waste rock sample from the Neves Corvo mine Portugal, a pure cultures of T. electrotropha and T. pacifica solubilized 30-40% Co, and 10-20% Cu, Zn, K, Cd, Mn and Ag at a higher pH (pH ≥ 4) and high chloride concentration. Though still requiring process optimization, this new biotechnology seems promising and offers remarkable benefits such as preventing extreme acidification of the environment while also being applicable in seawater.

Keywords: bioleaching; marine sulfur-oxidising bacteria; mine waste rock; seawater

  • Lecture (Conference)
    The 24th International Biohydrometallurgy Symposium, 20.-23.11.2022, Perth, Australia

Publ.-Id: 35790

Interesting halophilic sulfur-oxidising bacteria with bioleaching potential: Implications for pollutant mobilisation from mine waste

Opara, C. B.; Kamariah, N.; Spooren, J.; Pollmann, K.; Kutschke, S.

For many years, research on microbial-dissolution of metals from ores or waste materials mainly focused on the study of acidophilic organisms. However, most acidophilic bioleaching microorganisms have limited tolerance to high chloride concentrations, thereby requiring fresh water for bioleaching operations. There is a growing interest in the use of seawater for leaching purposes, especially in regions with less access to fresh water. Consequently, there is a need to find halophilic organisms with bioleaching potentials. This study investigated the bioleaching potentials of four moderately halophilic sulfur-oxidising bacteria: Thiomicrospira cyclica, Thiohalobacter thiocyanaticus, Thioclava electrotropha and Thioclava pacifica. Results revealed T. electrotropha and T. pacifica as the most promising for bioleaching. Pure cultures of the two Thioclava strains liberated about 30% Co, and between 8-17% Cu, Pb, Zn, K, Cd, and Mn from a mine waste rock sample from the Neves Corvo mine, Portugal. Microwave roasting of the waste rock at 400 and 500 °C improved the bioleaching efficiency of T. electrotropha for Pb (13.7 to 45.7%), Ag (5.3 to 36%) and In (0 to 27.4%). Mineralogical analysis of the bioleached residues using SEM/MLA-GXMAP showed no major difference in the mineral compositions before and after bioleaching by the Thioclava spp. Generally, the bioleaching rates of the Thioclava spp. are quite low compared to that of the conventional acidophilic bioleaching bacteria. Nevertheless, their ability to liberate potential pollutants (metal(loid)s) into solution from mine waste raises environmental concerns. This is due to their relevance in the biogeochemistry of mine waste dumps, as similar neutrophile halophilic sulfur-oxidising organisms (e.g. Halothiobacillus spp.) have been isolated from mine wastes. On the other hand, the use of competent halophilic microorganisms could be the future of bioleaching due to their high tolerance to Cl- ions and their potential to catalyse mineral dissolution in seawater media, instead of fresh water.

Keywords: bioleaching; halophilic sulfur-oxidising bacteria; mine waste rock; pollutant mobilisation; Thiomicrospira cyclica; Thiohalobacter thiocyanaticus; Thioclava electrotropha; Thioclava pacifica

Publ.-Id: 35788

Machine learning in biomedical images to study infection and disease

Yakimovich, A.

Recent advances in Machine Learning (ML) and Deep Learning (DL) are revolutionizing our abilities to analyze biomedical images and deepen our understanding of infection and disease. Among other host-pathogen interactions may be readily deciphered from microscopy data using convolutional neural networks (CNN). ML/DL algorithms may allow unambiguous scoring of virus-infected and uninfected cells in absence of specific labeling. Furthermore, accompanied by interpretability approaches, the ability of CNNs to learn representations, without explicit feature engineering, may allow uncovering yet unknown phenotypes in microscopy. One such example is our recent tandem segmentation-classification algorithm aimed to uncover morphological markers of Caenorhabditis elegans lifespan and motility. Taken together these novel approaches may facilitate novel discoveries in Infection and Disease Biology.

Keywords: deep learning; machine learning; bioimage analysis; host-pathogen interactions

  • Lecture (others)
    Big data analytical methods for complex systems, 06.-07.10.2022, Wroclaw, Poland
  • Lecture (others)
    CASUSCON, 11.-15.07.2022, Wroclaw, Poland
  • Lecture (others)
    Professor James Malone-Lee Christmas Lectures, 15.12.2022, Royal Free Hospital Campus, UCL, United Kingdom


Publ.-Id: 35787

AI and the Infectious Medicine of COVID-19

Vardan, A.; Anthony, P.; Yakimovich, A.

Coinciding with the global pandemic of SARS-CoV-2 and the resulting global public health crisis caused by COVID-19, artificial intelligence methods started playing an ever more important role in Infectious Medicine. On one hand this was a result of a continuous digital transformation of Infectious Medicine—a trend started decades ago. On the other hand, the pandemic catalyzed the adoption of artificial intelligence and other digital and quantitative techniques by Infectious Medicine. In this chapter we review recent works touching upon aspects of COVID-19 patient journey and how it interconnects with big data and artificial intelligence. These include early and clinical research, epidemiology and detection, diagnostics, clinical care and decision support, as well as long-term care and prevention. We cross-compare the published works and assess their maturity. Finally, we provide a conclusion on the state of artificial intelligence in the Infectious Medicine of COVID-19 and attempt a future perspective.

Keywords: SARS-CoV-2; Machine learning; Deep learning; Patient journey; Sequence; Biomedical image; Diagnostics

  • Book chapter
    Lidströmer, N., Eldar, Y.C.: Artificial Intelligence in Covid-19, Cham: Springer, 2022, 978-3-031-08505-5, 157-168
    DOI: 10.1007/978-3-031-08506-2_6

Publ.-Id: 35786

Modelling microstructures with flexible Laguerre Mosaics

Tolosana Delgado, R.; Avalos-Sotomayor, S.; van den Boogaart, K. G.; Frenzel, M.; Ortiz, J. M.; Pereira, L.; Riquelme, A.

Particle-based process models offer a promising avenue towards greater predictability in geometallurgy, i.e., the ability to predict the outcomes of specific mineral processing routes from the mineralogical and microstructural ore characteristics. While the particle-based prediction of separation processes is already possible with acceptable levels of accuracy, the ability to predict the outcomes of comminution processes is currently limited to particle size distributions. Expanding comminution modelling tools to include particle microstructures would enable the full particle-based modelling of mineral processing flowsheets. As a step towards the inclusion of microstructure in comminution modelling, Laguerre tessellations are proposed to represent both the microstructure and the successive comminution steps. In contrast to the PARGEN library of simulated particles, our goal is to provide a low-parametric, dynamic, and efficient generator of parent and progeny material to inform forward and backward modelling efforts.

The idea is to follow a hierarchical decision structure in the simulation procedure. We first define an intensity field in 3D for the occurrence cell nuclei, which are then realised by a marked Poisson process. The first mark corresponds to realisations of a multinomial variable, and defines the mineral of each potential cell. Conditional on the mineral, the second mark follows a normal distribution, defining the weight of each cell, related to its size. A communition step is defined by a Voronoi mosaic, with a (t+1)-step exhibiting a higher intensity of its Poisson process than the previous t-step. To model preferential breakage, we inhibit some of the potential breakage surfaces with a probability depending on the weighted average hardness and the cleavage quality of the minerals that each surface cuts. Two consecutive comminution steps generate the corresponding parent and progeny particles, Each independently cut by a random plane to generate the equivalent of a 2D SEM-based automated mineralogy dataset.

  • Poster
    21st Annual Conference of the International Association for Mathematical Geosciences, 29.08.-03.09.2022, Nancy, Frankreich
  • Poster
    21st Annual Conference of the International Association for Mathematical Geosciences, 29.08.-03.09.2022, Nancy, Frankreich

Publ.-Id: 35785

A weak-labelling and deep learning approach for in-focus object segmentation in 3D widefield microscopy

Li, R.; Kudryashev, M.; Yakimovich, A.

Three-dimensional information is crucial to our understanding of biological phenomena. The vast majority of biological microscopy specimens are inherently three-dimensional. However, conventional light microscopy is largely geared towards 2D images, while 3D microscopy and image reconstruction remain feasible only with specialized equipment and techniques. Inspired by the working principles of one such technique - confocal microscopy, we propose a novel approach to 3D widefield microscopy reconstruction through semantic segmentation of in-focus and out-of-focus pixels. For this, we explore a number of rule-based algorithms commonly used for software-based autofocusing and apply them to a dataset of widefield focal stacks. We propose a computation scheme allowing the calculation of lateral focus score maps of the slices of each stack using these algorithms. Furthermore, we identify algorithms preferable for obtaining such maps. Finally, to ensure the practicality of our approach, we propose a surrogate model based on a deep neural network, capable of segmenting in-focus pixels from the out-of-focus background in a fast and reliable fashion. The deep-neural-network-based approach allows a major speedup for data processing making it usable for online data processing.

Keywords: weak-labeling; deep neural network; widefield microscopy; surrogate model

  • Poster
    6th International Symposium on Image-based Systems Biology, 08.-09.09.2022, Jena, Germany

Publ.-Id: 35783

Translating widefield microscopy images into the 3D using neural networks

Li, R.; Kudryashev, M.; Yakimovich, A.

Understanding the 3D structure of biological entities is crucial for gaining mechanistic biomedical knowledge. A confocal light microscope is a well-established tool used to obtain 3D data from biological specimens. Yet, it comes with the drawbacks of high equipment prices and heavy human labor. In this project, we introduce a 3D focal stacking solution using deep neural networks (DNN). Instead of restoring 3D models from confocal microscopes, our model produces in-focus images by inputting widefield microscope images, which may be obtained with significantly simpler equipment. This enables the translation from widefield microscope images into the 3D model by segmenting the in-focus pixels, allowing the image of 3D biological specimens in vivo.

Keywords: 3D microscopy; machine learning

  • Poster
    6th International Symposium "Image-based Systems Biology, 08.-09.09.2022, Jena, Germany

Publ.-Id: 35782

Phenix EOL natural convection test: Serpent/DYN3D/ATHLET I/O data

Fridman, E.; Nikitin, E.; Ponomarev, A.

  1. The dataset contains DYN3D/ATHLET input data used for modeling Phenix End-Of-Life natural convection test. 
  2. The dataset also contains Serpent inputs used to produce XS data for DYN3D


Publ.-Id: 35779

In-situ measurements of dendrite tip shape selection in a metallic alloy

Neumann-Heyme, H.; Shevchenko, N.; Grenzer, J.; Eckert, K.; Beckermann, C.; Eckert, S.

The size and shape of the primary dendrite tips determine the principal length scale of the microstructure evolving during solidification of alloys. In-situ X-ray measurements of the tip shape in metals have been unsuccessful so far due to insufficient spatial resolution or high image noise. To overcome these limitations, high-resolution synchrotron radiography and advanced image processing techniques are applied to a thin sample of a solidifying Ga-35wt.%In alloy. Quantitative in-situ measurements are performed of the growth of dendrite tips during the fast initial transient and the subsequent steady growth period, with tip velocities ranging over almost two orders of magnitude. The value of the dendrite tip shape selection parameter is found to be σ^*=0.0768, which suggests an interface energy anisotropy of ε_4=0.015 for the present Ga-In alloy. The non-axisymmetric dendrite tip shape amplitude coefficient is measured to be A_4≈0.004, which is in excellent agreement with the universal value previously established for dendrites.

Keywords: dendritic solidification; x-ray imaging


Publ.-Id: 35778

Historical geocoding assistant

Mertel, A.; Zbíral, D.; Stachoň, Z.; Hořínková, H.

The growing use of geographic information systems (GIS) and geographical analyses in different areas of the digital humanities highlights the need for geocoding, i.e. assigning geographic coordinates to records in a dataset. Such spatially-referenced datasets are a precondition for any spatial analysis and visualization. While GIS in general is a dynamically evolving branch of software development, there is a need for specialized applications which would assist researchers in geocoding datasets in history, archaeology, and the digital humanities. Therefore, we developed the “Historical Geocoding Assistant”, an open-source web tool that meets the specific needs of historical research and brings a solution to geocoding historical data in a convenient, fast, and reliable way.

Keywords: geocoding; geohumanities

Publ.-Id: 35775

Pages: [1.] [2.] [3.] [4.] [5.] [6.] [7.] [8.] [9.] [10.] [11.] [12.] [13.] [14.] [15.] [16.] [17.] [18.] [19.] [20.] [21.] [22.] [23.] [24.] [25.] [26.] [27.] [28.] [29.] [30.] [31.] [32.] [33.] [34.] [35.] [36.] [37.] [38.] [39.] [40.] [41.] [42.] [43.] [44.] [45.] [46.] [47.] [48.] [49.] [50.] [51.] [52.] [53.] [54.] [55.] [56.] [57.] [58.] [59.] [60.] [61.] [62.] [63.] [64.] [65.] [66.] [67.] [68.] [69.] [70.] [71.] [72.] [73.] [74.] [75.] [76.] [77.] [78.] [79.] [80.] [81.] [82.] [83.] [84.] [85.] [86.] [87.] [88.] [89.] [90.] [91.] [92.] [93.] [94.] [95.] [96.] [97.] [98.] [99.] [100.] [101.] [102.] [103.] [104.] [105.] [106.] [107.] [108.] [109.] [110.] [111.] [112.] [113.] [114.] [115.] [116.] [117.] [118.] [119.] [120.] [121.] [122.] [123.] [124.] [125.] [126.] [127.] [128.] [129.] [130.] [131.] [132.] [133.] [134.] [135.] [136.] [137.] [138.] [139.] [140.] [141.] [142.] [143.] [144.] [145.] [146.] [147.] [148.] [149.] [150.] [151.] [152.] [153.] [154.] [155.] [156.] [157.] [158.] [159.] [160.] [161.] [162.] [163.] [164.] [165.] [166.] [167.] [168.] [169.] [170.] [171.] [172.] [173.] [174.] [175.] [176.] [177.] [178.] [179.] [180.] [181.] [182.] [183.] [184.] [185.] [186.] [187.] [188.] [189.] [190.] [191.] [192.] [193.] [194.] [195.] [196.] [197.] [198.] [199.] [200.] [201.] [202.] [203.] [204.] [205.] [206.] [207.] [208.] [209.] [210.] [211.] [212.] [213.] [214.] [215.] [216.] [217.] [218.] [219.] [220.] [221.] [222.] [223.] [224.] [225.] [226.] [227.] [228.] [229.] [230.] [231.] [232.] [233.] [234.] [235.] [236.] [237.] [238.] [239.] [240.] [241.] [242.] [243.] [244.] [245.] [246.] [247.] [248.] [249.] [250.] [251.] [252.] [253.] [254.] [255.] [256.] [257.] [258.] [259.] [260.] [261.] [262.] [263.] [264.] [265.] [266.] [267.] [268.] [269.] [270.] [271.] [272.] [273.] [274.] [275.] [276.] [277.] [278.] [279.] [280.] [281.] [282.] [283.] [284.] [285.] [286.] [287.] [288.] [289.] [290.] [291.] [292.] [293.] [294.] [295.] [296.] [297.] [298.] [299.] [300.] [301.] [302.] [303.] [304.] [305.] [306.] [307.] [308.] [309.] [310.] [311.] [312.] [313.] [314.] [315.] [316.] [317.] [318.] [319.] [320.] [321.] [322.] [323.] [324.] [325.] [326.] [327.] [328.]