TY - JOUR
A1 - Li, Guiping
A1 - Liu, Ye
A1 - Schultz, Thorsten
A1 - Exner, Moritz
A1 - Muydinov, Ruslan
A1 - Wang, Hui
A1 - Scheurell, Kerstin
A1 - Huang, Jieyang
A1 - Szymoniak, Paulina
A1 - Pinna, Nicola
A1 - Koch, Norbert
A1 - Adelhelm, Philipp
A1 - Bojdys, Michael J.
T1 - One‐Pot Synthesis of High‐Capacity Sulfur Cathodes via In‐Situ Polymerization of a Porous Imine‐Based Polymer
JF - Angewandte Chemie International Edition
N2 - AbstractLithium‐ion batteries, essential for electronics and electric vehicles, predominantly use cathodes made from critical materials like cobalt. Sulfur‐based cathodes, offering a high theoretical capacity of 1675 mAh g−1 and environmental advantages due to sulfur's abundance and lower toxicity, present a more sustainable alternative. However, state‐of‐the‐art sulfur‐based electrodes do not reach the theoretical capacities, mainly because conventional electrode production relies on mixing of components into weakly coordinated slurries. Consequently, sulfur‘s mobility leads to battery degradation—an effect known as the “sulfur‐shuttle”. This study introduces a solution by developing a microporous, covalently‐bonded, imine‐based polymer network grown in situ around sulfur particles on the current collector. The polymer network (i) enables selective transport of electrolyte and Li‐ions through pores of defined size, and (ii) acts as a robust host to retain the active component of the electrode (sulfur species). The resulting cathode has superior rate performance from 0.1 C (1360 mAh g−1) to 3 C (807 mAh g−1). Demonstrating a high‐performance, sustainable sulfur cathode produced via a simple one‐pot process, our research underlines the potential of microporous polymers in addressing sulfur diffusion issues, paving the way for sulfur electrodes as viable alternatives to traditional metal‐based cathodes.
KW - In-situ polymerization
KW - Sulfur cathodes
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-604215
DO - https://doi.org/10.1002/anie.202400382
SN - 1433-7851
SP - 1
EP - 11
PB - Wiley VHC-Verlag
AN - OPUS4-60421
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Pallasch, Sebastian M.
A1 - Bhosale, Manik
A1 - Smales, Glen J.
A1 - Schmidt, Caroline
A1 - Riedel, Sibylle
A1 - Zhao-Karger, Zhirong
A1 - Esser, Birgit
A1 - Dumele, Oliver
T1 - Porous Azatruxene Covalent Organic Frameworks for Anion Insertion in Battery Cells
N2 - Covalent organic frameworks (COFs) containing well-defined redox-active groups have become competitive materials for next-generation batteries. Although high potentials and rate performance can be expected, only a few examples of p-type COFs have been reported for charge storage to date with even fewer examples on the use of COFs in multivalent ion batteries. Herein, we report the synthesis of a p-type highly porous and crystalline azatruxene-based COF and its application as a positive electrode material in Li- and Mg-based batteries. When this material is used in Li-based half cells as a COF/carbon nanotube (CNT) electrode, a discharge potential of 3.9 V is obtained with discharge capacities of up to 70 mAh g−1 at a 2 C rate. In Mg batteries using a tetrakis(hexafluoroisopropyloxy)borate electrolyte, cycling proceeds with an averge discharge voltage of 2.9 V. Even at a fast current rate of 5 C, the capacity retention amounts to 84% over 1000 cycles.
KW - COFs
PY - 2024
DO - https://doi.org/10.1021/jacs.4c04044
VL - 146
IS - 25
SP - 17318
EP - 17324
PB - Journal of the American Chemical Society
AN - OPUS4-60419
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Glazyrin, Konstantin
A1 - Spektor, Kristina
A1 - Bykov, Maxim
A1 - Dong, Weiwei
A1 - Yu, Ji‐Hun Yu
A1 - Yang, Sangsun Yang
A1 - Lee, Jai‐Sung Lee
A1 - Divinski, Sergiy V.
A1 - Hanfland, Michael
A1 - Yusenko, Kirill V.
T1 - High‐Entropy Alloys and Their Affinity with Hydrogen: From Cantor to Platinum Group Elements Alloys
JF - Advanced Science
N2 - AbstractProperties of high‐entropy alloys are currently in the spotlight due to their promising applications. One of the least investigated aspects is the affinity of these alloys to hydrogen, its diffusion, and reactions. In this study, high pressure is applied at ambient temperature and stress‐induced diffusion of hydrogen is investigated into the structure of high‐entropy alloys (HEA) including the famous Cantor alloy as well as less known, but nevertheless important platinum group (PGM) alloys. By applying X‐ray diffraction to samples loaded into diamond anvil cells, a comparative investigation of transition element incorporating HEA alloys in Ne and H2 pressure‐transmitting media is performed at ambient temperature. Even under stresses far exceeding conventional industrial processes, both Cantor and PGM alloys show exceptional resistance to hydride formation, on par with widely used industrial grade Cu–Be alloys. The observations inspire optimism for practical HEA applications in hydrogen‐relevant industry and technology (e.g., coatings, etc), particularly those related to transport and storage.
KW - XRD
KW - HIgh entropy,
KW - Cantor
KW - Alloys
KW - Synchrotron
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-604170
DO - https://doi.org/10.1002/advs.202401741
SP - 1
EP - 8
PB - Wiley VHC-Verlag
AN - OPUS4-60417
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Dudziak, Mateusz
A1 - Bhatia, Riya
A1 - Dey, R.
A1 - Falkenhagen, Jana
A1 - Ullrich, M. S.
A1 - Thomsen, C.
A1 - Schartel, Bernhard
T1 - Wastewater phosphorus enriched algae as a sustainable flame retardant in polylactide
JF - Polymer Degradation and Stability
N2 - Revolutionizing our polymer industry for adaption to a sustainable carbon circular economy has become one of today’s most demanding challenges. Exploiting renewable resources to replace fossil-fuel—based plastics with biopolymers such as poly(lactic acid) (PLA) is inevitable while using waste streams as a raw material resource at least is promising. When it comes to using PLA as technical polymer, its high flammability must be addressed by flame retardants compatible with the thermoplastic processing of PLA and its compostability. This study proposes microalgae enriched with phosphorus from wastewater (P-Algae) as an elegant way towards a kind of sustainable organophosphorus flame retardant. The concept is demonstrated by investigating the processing, pyrolysis, flammability, and fire behavior of PLA/P-Algae, while varying the P-Algae content and comparing P-Algae with four alternative bio-fillers (phosphorylated lignin, biochar, thermally treated sewage sludge, and metal phytate) with different P-contents as meaningful benchmarks.
KW - PLA
KW - Flame Retardancy
KW - Phosphorylated Algae
KW - Wastewater flame retardants
KW - Zink phytate
KW - Phosphorylated lignin
KW - Thermally treated sludge
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-604150
DO - https://doi.org/10.1016/j.polymdegradstab.2024.110885
SN - 1873-2321
SN - 0141-3910
VL - 227
SP - 1
EP - 11
PB - Elsevier Ltd.
AN - OPUS4-60415
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Zorn, R.
A1 - Szymoniak, Paulina
A1 - Kolmangadi, Mohamed Aejaz
A1 - Malpass-Evans, R.
A1 - McKeown, N.
A1 - Jalarvo, N.
A1 - Tyagi, M.
A1 - Böhning, Martin
A1 - Schönhals, Andreas
T1 - Microscopic molecular mobility of high-performance polymers of intrinsic microporosity revealed by neutron scattering – bend fluctuations and signature of methyl group rotation
JF - Soft Matter
N2 - Polymers of intrinsic microporosity exhibit a combination of high gas permeability and reasonable permselectivity, which makes them attractive candidates for gas separation membrane materials. The diffusional selective gas transport properties are connected to the molecular mobility of these polymers in the condensed state. Incoherent quasielastic neutron scattering was carried out on two polymers of intrinsic microporosity, PIM-EA-TB(CH3) and its demethylated counterpart PIM-EA-TB(H2), which have high Brunauer–Emmett–Teller surface area values of 1030 m2 g-1 and 836 m2 g-1, respectively. As these two polymers only differ in the presence of two methyl groups at the ethanoanthracene unit, the effect of methyl group rotation can be investigated solely. To cover a broad dynamic range, neutron time-of-flight was combined with neutron backscattering. The demethylated PIM-EA-TB(H2) exhibits a relaxation process with a weak intensity at short times. As the backbone is rigid and stiff this process was assigned to bendand-flex fluctuations. This process was also observed for the PIM-EA-TB(CH3). A further relaxation process is found for PIM-EA-TB(CH3), which is the methyl group rotation. It was analyzed by a jump-diffusion in a three-fold potential considering also the fact that only a fraction of the present hydrogens in PIM-EATB(CH3) participate in the methyl group rotation. This analysis can quantitatively describe the q dependence of the elastic incoherent structure factor. Furthermore, a relaxation time for the methyl group rotation can be extracted. A high activation energy of 35 kJ mol-1 was deduced. This high activation energy evidences a strong hindrance of the methyl group rotation in the bridged PIM-EA-TB(CH3) structure.
KW - Polymers of Intrinsic Microporosity
KW - Neutron Scattering
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-604114
DO - https://doi.org/10.1039/d4sm00520a
SP - 1
EP - 11
PB - RSC
AN - OPUS4-60411
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Das, Prasenjit
A1 - Chakraborty, Gouri
A1 - Friese, Nico
A1 - Roeser, Jérôme
A1 - Prinz, Carsten
A1 - Emmerling, Franziska
A1 - Schmidt, Johannes
A1 - Thomas, Arne
T1 - Heteropolyaromatic Covalent Organic Frameworks via One-Pot Multicomponent Reactions
JF - Journal of the American Chemical Society
N2 - Multicomponent reactions (MCRs) offer a platform to create different chemical structures and linkages for highly stable covalent organic frameworks (COFs). As an illustrative example, the multicomponent Povarov reaction generates 2,4-phenylquinoline from aldehydes and amines in the presence of electron-rich alkenes. In this study, we introduce a new domino reaction to generate unprecedented 2,3-phenylquinoline COFs in the presence of epoxystyrene. This work thus presents, for the first time, structural isomeric COFs produced by multicomponent domino and Povarov reactions. Furthermore, 2,3-phenylquinolines can undergo a Scholl reaction to form extended aromatic linkages. With this approach, we synthesize two thermally and chemically stable MCR-COFs and two heteropolyaromatic COFs using both domino and in situ domino and Scholl reactions. The structure and properties of these COFs are compared with the corresponding 2,4-phenylquinoline-linked COF and imine-COF, and their activity toward benzene and cyclohexane sorption and separation is investigated. The position of the pendant phenyl groups within the COF pore plays a crucial role in facilitating the industrially important sorption and separation of benzene over cyclohexane. This study opens a new avenue to construct heteropolyaromatic COFs via MCR reactions.
KW - COF
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-604038
DO - https://doi.org/10.1021/jacs.4c02551
SP - 1
EP - 9
PB - American Chemical Society (ACS)
AN - OPUS4-60403
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Cakir, Cafer Tufan
A1 - Bogoclu, Can
A1 - Emmerling, Franziska
A1 - Streli, Christina
A1 - Guilherme Buzanich, Ana
A1 - Radtke, Martin
T1 - Machine learning for efficient grazing-exit x-ray absorption near edge structure spectroscopy analysis: Bayesian optimization approach
JF - Machine Learning: Science and Technology
N2 - In materials science, traditional techniques for analyzing layered structures are essential for obtaining information about local structure, electronic properties and chemical states. While valuable, these methods often require high vacuum environments and have limited depth profiling capabilities. The grazing exit x-ray absorption near-edge structure (GE-XANES) technique addresses these limitations by providing depth-resolved insight at ambient conditions, facilitating in situ material analysis without special sample preparation. However, GE-XANES is limited by long data acquisition times, which hinders its practicality for various applications. To overcome this, we have incorporated Bayesian optimization (BO) into the GE-XANES data acquisition process. This innovative approach potentially reduces measurement time by a factor of 50. We have used a standard GE-XANES experiment, which serve as reference, to validate the effectiveness and accuracy of the BO-informed experimental setup. Our results show that this optimized approach maintains data quality while significantly improving efficiency, making GE-XANES more accessible to a wider range of materials science applications.
KW - Machine Learning
KW - GE-XANES
KW - Bayesian Optimization
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-603955
DO - https://doi.org/10.1088/2632-2153/ad4253
VL - 5
IS - 2
SP - 1
EP - 12
PB - IOP Publishing
AN - OPUS4-60395
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Nicolicea, Alberto
A1 - Oliveros-Mata, E.
A1 - Makarov, D.
A1 - Melzer, Michael
A1 - Pelkner, Matthias
A1 - Zabila, Y.
T1 - Flexible anisotropic magnetoresistive sensors for novel magnetic flux leakage testing capabilities
JF - NDT&E international
N2 - Rigid magnetic field sensors such as anisot Hall sensors have been used for years and have become industry standard for electromagnetic non-destructive testing (NDT). Recent technological developments in the field of flexible electronics allow for the fabrication of reshapeable magnetic field sensors on flexible substrates via thin-film deposition or printing. The magnetic properties of these sensors have comparable characteristics to industry-standard rigid magnetic field sensors, with the added ability of adapting to the surface of complex components and scanning in contact with the sample surface. This improves defect detectability and magnetic signal strength by minimizing the scanning lift-off (LO) distance. In this article flexible AMR sensors mounted on a rotative mechanical holder were used to scan a semi-circular ferromagnetic sample with 3 reference defects via magnetic flux leakage (MFL) testing, thus demonstrating the applicability of this type of sensors for the scanning of curved samples. In order to benchmark the performance of these sensors in comparison to industry standard rigid magnetic field sensors, a ferromagnetic sample with 10 reference defects of different depths was scanned employing flexible AMR and rigid GMR sensors. Defects with depths ranging from 110 μm up to 2240 μm were detected with an signal-tonoise ratio (SNR) of 2.7 up to 27.9 (for flexible AMR sensors) and 6.2 up to 72.3 (for rigid GMR sensors), respectively. A 2D magnetometer mapping of the sample with a spatial scanning step of 10 × 50 μm2 (flexible AMR) and 16 × 100 μm2 (rigid GMR) was obtained. The results show that this type of sensor can be used for high-resolution and high-detail mapping of defects on the surface of planar and non-planar ferromagnetic samples since the scanning lift-off distance is equal to the substrate thickness of 20 μm for in-contact scanning. The SNR comparison between flexible and rigid sensors shows that the performance of the flexible AMR sensors employed is not very far behind the performance of the rigid GMR sensors used.
KW - Flexible magnetic field sensors
KW - Non-destructive testing
KW - Magnetic flux leakage
KW - Thin film sensor fabrication
KW - Defect detection
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-603931
DO - https://doi.org/10.1016/j.ndteint.2024.103160
VL - 146
SP - 1
EP - 15
PB - Elsevier Ltd.
AN - OPUS4-60393
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Häßler, Dustin
A1 - Mund, Maximilian
A1 - Daus, Lars-Hendrik
A1 - Hothan, Sascha
A1 - Schaumann, Peter
A1 - Schartel, Bernhard
T1 - Durability of intumescent coatings and recommendations for test concepts for a working life of more than 10 years
JF - Fire Safety Journal
N2 - It is an essential requirement for all building products to ensure durability of their fire safety. Throughout the working life of products, intumescent coatings are aged by certain climatic factors. To predict a lifetime of several years, generally the behaviour of the intumescent coating is extrapolated based on accelerated artificial ageing. The established German and European procedures to assess the durability assume a working life of at least 10 years. For a longer period, additional evidence is required; yet the procedure and the specifications to justify this are not described. In addition to addressing this formal lack, from a scientific point of view it is necessary to investigate the degradation of intumescent coatings in detail and to propose a reliable test concept to assess durability for more than 10 years. This paper summarises the existing knowledge about the ageing of intumescent coatings. The results of various demanding weathering approaches are presented for two intumescent coatings tested in a joint research project. Moreover, formulations with a reduced amount of functionally relevant components were analysed to gain insight into the associated effects. Derived from these research results and knowledge, recommendations are proposed to assess the durability of intumescent coatings for more than 10 years based on a combination of verifications.
KW - Ageing
KW - Fire protection
KW - Intumescent coating
KW - Steel construction
KW - Working life
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-603852
DO - https://doi.org/10.1016/j.firesaf.2024.104173
SN - 0379-7112
VL - 146
SP - 1
EP - 10
PB - Elsevier B.V.
AN - OPUS4-60385
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - da Costa, P. F. G. M.
A1 - Merízio, L. G.
A1 - Wolff, N.
A1 - Terraschke, H.
A1 - de Camargo, A. S. S.
T1 - Real-time monitoring of CdTe quantum dots growth in aqueous solution
JF - Scientific Reports
N2 - Quantum dots (QDs) are remarkable semiconductor nanoparticles, whose optical properties are strongly size-dependent. Therefore, the real-time monitoring of crystal growth pathway during synthesis gives an excellent opportunity to a smart design of the QDs luminescence. In this work, we present a new approach for monitoring the formation of QDs in aqueous solution up to 90 °C, through in situ luminescence analysis, using CdTe as a model system. This technique allows a detailed examination of the evolution of their light emission. In contrast to in situ absorbance analysis, the in situ luminescence measurements in reflection geometry are particularly advantageous once they are not hindered by the concentration increase of the colloidal suspension. The synthesized particles were additionally characterized using X-ray diffraction analysis, transition electron microscopy, UV-Vis absorption and infrared spectroscopy. The infrared spectra showed that 3-mercaptopropionic acid (MPA)-based thiols are covalently bound on the surface of QDs and microscopy revealed the formation of CdS. Setting a total of 3 h of reaction time, for instance, the QDs synthesized at 70, 80 and 90 °C exhibit emission maxima centered at 550, 600 and 655 nm. The in situ monitoring approach opens doors for a more precise achievement of the desired emission wavelength of QDs.
KW - CdTe quantum dots
KW - In situ synthesis
KW - Real time growth control
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-603596
DO - https://doi.org/10.1038/s41598-024-57810-8
VL - 14
IS - 1
SP - 1
EP - 11
PB - Springer Science and Business Media LLC
AN - OPUS4-60359
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Galleani, Gustavo
A1 - Lodi, Thiago A.
A1 - Conner, Robin L.
A1 - Jacobsohn, Luiz G.
A1 - de Camargo, Andrea S.S.
T1 - Photoluminescence and X-ray induced scintillation in Gd3+-Tb3+ co-doped fluoride-phosphate glasses, and derived glass-ceramics containing NaGdF4 nanocrystals
JF - Optical Materials: X
N2 - The glass system (50NaPO3–20BaF2–10CaF2–20GdF3)-xTbCl3 with x = 0.3, 1, 3, 5, and 10 wt % was investigated. We successfully produced transparent glass ceramic (GC) scintillators with x = 1 through a melt-quenching process followed by thermal treatment. The luminescence and crystallization characteristics of these materials were thoroughly examined using various analytical methods. The nanocrystallization of Tb3+-doped Na5Gd9F32 within the doped fluoride-phosphate glasses resulted in enhanced photoluminescence (PL) and radioluminescence (RL) of the Tb3+ ions. The GC exhibited an internal PL quantum yield of 33 % and the integrated RL intensity across the UV-visible range was 36 % of that reported for the commercial BGO powder scintillator. This research showcases that Tb-doped fluoridephosphate GCs containing nanocrystalline Na5Gd9F32 have the potential to serve as efficient scintillators while having lower melting temperature compared to traditional silicate and germanate glasses.
KW - Glass scintillator
KW - Fluoride phosphate glasses
KW - Gd3+
KW - Tb3+
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-603588
DO - https://doi.org/10.1016/j.omx.2023.100288
VL - 21
SP - 1
EP - 9
PB - Elsevier B.V.
AN - OPUS4-60358
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Zhang, Fengchan
A1 - Oiticica, Pedro Ramon Almeida
A1 - Abad-Arredondo, Jaime
A1 - Arai, Marylyn Setsuko
A1 - Oliveira, Osvaldo N.
A1 - Jaque, Daniel
A1 - Fernandez Dominguez, Antonio I.
A1 - de Camargo, Andrea Simone Stucchi
A1 - Haro-González, Patricia
T1 - Brownian Motion Governs the Plasmonic Enhancement of Colloidal Upconverting Nanoparticles
JF - Nano Letters
N2 - Upconverting nanoparticles are essential in modern photonics due to their ability to convert infrared light to visible light. Despite their significance, they exhibit limited brightness, a key drawback that can be addressed by combining them with plasmonic nanoparticles. Plasmon-enhanced upconversion has been widely demonstrated in dry environments, where upconverting nanoparticles are immobilized, but constitutes a challenge in liquid media where Brownian motion competes against immobilization.
This study employs optical tweezers for the three-dimensional manipulation of an individual upconverting nanoparticle, enabling the exploration of plasmon-enhanced upconversion luminescence in water. Contrary to expectation, experiments reveal a long-range (micrometer scale) and moderate (20%) enhancement in upconversion luminescence due to the plasmonic resonances of gold nanostructures. Comparison between experiments and numerical simulations evidences the key role of Brownian motion. It is demonstrated how the three-dimensional Brownian fluctuations of the upconverting nanoparticle lead to an “average effect” that explains the magnitude and spatial extension of luminescence enhancement.
KW - Upconversion
KW - Plasmon enhancement
KW - Optical tweezers
KW - Brownian motion
KW - Nanoparticles
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-603551
DO - https://doi.org/10.1021/acs.nanolett.4c00379
VL - 24
IS - 12
SP - 3785
EP - 3792
PB - American Chemical Society (ACS)
AN - OPUS4-60355
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Tatzel, Michael
A1 - Oelze, Marcus
A1 - Frick, Daniel A.
A1 - Di Rocco, Tommaso
A1 - Liesegang, Moritz
A1 - Stuff, Maria
A1 - Wiedenbeck, Michael
T1 - Silicon and oxygen isotope fractionation in a silicified carbonate rock
JF - Chemical Geology
N2 - Silicon isotope fractionation during silicification is poorly understood and impedes our ability to decipher paleoenvironmental conditions from Si isotopes in ancient cherts. To investigate isotope fractionation during silica-for-carbonate replacement we analyzed the microscale Si and O isotope composition in different silica phases in a silicified zebra dolostone as well as their bulk δ18O and Δ’17O compositions. The subsequent replacement of carbonate layers is mimicked by decreasing δ18O and δ30Si. The textural relationship and magnitude of Si and O isotope fractionation is best explained by near-quantitative silica precipitation in an open system with finite Si. A Rayleigh model for silicification suggests positive Ɛ30/28Si during silicification, conforming with predictions for isotope distribution at chemical equilibrium from ab-initio models. Application of the modelled Ɛ30Si-T relationship yields silicification temperatures of approx. 50°C. To reconcile the δ18Ochert composition with these temperatures, the δ18O of the fluid must have been between -2.5 and -4 ‰, compositions for which the quartz phases fall close to the oxygen equilibrium fractionation line in three-isotope space. Diagenetic silica replacement appears to occur in O and Si isotopic equilibrium allowing reconstructions of temperatures of silicification from Si isotopes and derive the δ18O composition of the fluid – a highly desired value needed for accurate reconstructions of the temperature- and δ18O histories of the oceans.
KW - Silicon isotopes
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-603430
DO - https://doi.org/10.1016/j.chemgeo.2024.122120
SN - 0009-2541
VL - 658
SP - 1
EP - 13
PB - Elsevier B.V.
AN - OPUS4-60343
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Bulling, Jannis
A1 - Jurgelucks, B.
A1 - Prager, Jens
A1 - Walther, A.
T1 - Experimental validation of an inverse method for defect reconstruction in a two-dimensional waveguide model
JF - The Journal of the Acoustical Society of America
N2 - Defect reconstruction is essential in non-destructive testing and structural health monitoring with guided ultrasonic waves. This paper presents an algorithm for reconstructing notches in steel plates, which can be seen as artificial defects representing cracks by comparing measured results with those from a simulation model. The model contains a parameterized notch, and its geometrical parameters are to be reconstructed. While the algorithm is formulated and presented in a general notation, a special case of guided wave propagation is used to investigate one of the simplest possible simulation models that discretizes only the cross section of the steel plate. An efficient simulation model of the plate cross section is obtained by the semi-analytical scaled boundary finite element method. The reconstruction algorithm applied is gradient-based, and algorithmic differentiation calculates the gradient. The dedicated experimental setup excites nearly plane wave fronts propagating orthogonal to the notch. A scanning laser Doppler vibrometer records the velocity field at certain points on the plate surface as input to the reconstruction algorithm. Using two plates with notches of different depths, it is demonstrated that accurate geometry reconstruction is possible.
KW - Ultrasound
KW - Waveguides
KW - Symbolic computation
KW - Optimization problems
PY - 2024
DO - https://doi.org/10.1121/10.0025469
SN - 0001-4966
VL - 155
IS - 6
SP - 3794
EP - 3806
PB - Acoustical Society of America (ASA)
AN - OPUS4-60325
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Campari, Alessandro
A1 - Konert, Florian
A1 - Sobol, Oded
A1 - Alvaro, Antonio
T1 - A comparison of vintage and modern X65 pipeline steel using hollow specimen technique for in-situ hydrogen testing
JF - Engineering Failure Analysis
N2 - The transition toward a hydrogen-based economy requires a widespread transport and distribution network, and repurposed natural gas pipelines are a viable option. An assessment of the hydrogen-induced degradation of pipeline steels is needed to inject H2 gas into the existing infrastructure safely. The conservative and standardized method consists of in-situ tensile tests in an autoclave filled with high-pressure hydrogen gas. A proposed alternative method involves
using a hollow specimen as containment volume and applying the gas pressure in the inner cavity.
This technique has lower costs and shorter test preparation time but is not standardized yet. This study aims to evaluate and compare the tensile properties of API 5L X65 pipeline steel in two states: vintage and modern. The influence of the surface roughness is investigated through parallel tests with drilled and reamed specimens. Hydrogen tests are compared with reference tests in an inert environment. A significant hydrogen-induced decrease in tensile properties is observed, and no significant difference between vintage and modern X65 can be drawn. The reduction in tensile properties is more significant in specimens with higher inner surface roughness. The evaluation of surface conditions appears crucial when assessing the HE susceptibility of hydrogen transport and storage equipment.
KW - Hydrogen embrittlement
KW - Hollow specimen technique
KW - Pipeline steel
KW - SSRT
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-603013
DO - https://doi.org/10.1016/j.engfailanal.2024.108530
VL - 163
SP - 1
EP - 15
PB - Elsevier Ltd.
AN - OPUS4-60301
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Pereira, Raíssa Monteiro
A1 - Lohbauer, Ulrich
A1 - Schulbert, Christian
A1 - Göken, Mathias
A1 - Wurmshuber, Michael
A1 - Campos, Tiago Bastos Moreira
A1 - Thim, Gilmar Patrocínio
A1 - Mieller, Björn
A1 - Belli, Renan
T1 - Instantiations of Multiscale Kinship in Pressing‐Defect Distributions in Yttria‐Stabilized Zirconias by Powder Partitioning
JF - Advanced Engineering Materials
N2 - Modern dry pressing of ceramic powders using spray‐dried granulates cannot avoid the occurrence of defects related to persisting inter‐ and intra‐granulate interstitial voids. These constitute the parent defect size population limiting the application of polycrystalline ceramics in high‐stress conditions. The mitigation of such defects could widen the range of application in technical and biomedical engineering, reduce the safety range for design, and extend the lifetime of components. Herein, the Weibull size‐effect on strength in size‐partitioned Yttria‐stabilized zirconias (YSZ) feedstocks is used to explore the viability of changing the density distribution of granulate sizes as an effective strategy to obtain a denser particle packing that could reduce the size distribution of strength‐limiting pressing defects. In a direct assessment of critical defect size using multiscale strength testing with a dataset of ≈1300 values, the success of such an approach in increasing the strength reliability for small volume components is demonstrated, along with its ultimate failure in altering the defect size distribution in sintered YSZ ceramics across several length scales. Finally, it is shown that granule morphology (spherical or dimpled) fails to affect the defect density and size distribution in YSZ ceramics.
KW - Zirconia
KW - Strength
KW - Toughness
KW - Weibull distribution
KW - Defect population
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-602697
DO - https://doi.org/10.1002/adem.202400139
SN - 1438-1656
SP - 1
EP - 17
PB - Wiley VHC-Verlag
AN - OPUS4-60269
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Gadelmeier, C.
A1 - Agudo Jacome, Leonardo
A1 - Suarez Ocano, Patricia
A1 - Glatzel, U.
T1 - Effect of stacking fault energy (SFE) of single crystal, equiatomic CrCoNi and Cantor alloy on creep resistance
JF - Material Science & Engineerin A
N2 - Compared to mechanisms like solid solution strengthening, the stacking fault energy (SFE) should be considered as a further factor that influences the material properties. The effect of SFE of alloys or individual elements on strength and resistance can vary considerably. In the high-temperature regime above 700 ◦C, there are still significant gaps in the knowledge about the effect of the SFE on the mechanical properties of single-phase alloys. The effect of SFE on creep resistance of two face-entered cubic equiatomic medium and high entropy alloys, CrCoNi and CrMnFeCoNi, respectively, is evaluated to fill parts of these gaps. Using the Bridgman solidification process, the alloys were produced as single crystals and crept under vacuum at 700 ◦C up to 1100 ◦C. This work shows a significant impact of the lower SFE of CrCoNi on the creep behavior compared to the results of previous investigations of CrMnFeCoNi. The creep resistance of the former is higher over the complete temperature range. At very high temperatures, the strengthening effect of the stacking faults is significantly present. The formation of tetragonal stacking faults and extended dislocation nodes can be identified as the reason for this effect.
KW - Medium entropy alloy
KW - MEA
KW - HEA
KW - Single crystal
KW - CrCoNi
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-602620
DO - https://doi.org/10.1016/j.msea.2024.146779
SN - 0921-5093
VL - A 908
SP - 1
EP - 9
PB - Elsevier B.V.
AN - OPUS4-60262
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Mohr, Gunther
A1 - Chaudry, Mohsin Ali
A1 - Scheuschner, Nils
A1 - Blasón González, Sergio
A1 - Madia, Mauro
A1 - Hilgenberg, Kai
T1 - Thermal history transfer from complex components to representative test specimens in laser powder bed fusion
JF - Progress in Additive Manufacturing
N2 - Additively manufactured components are characterized by heterogeneous mechanical properties due to variations of the microstructure, flaws and residual stresses resulting from the inhomogeneous fabrication process. The large number of influencing factors poses a further challenge in understanding the correlation between material properties, process parameters and component geometry. Therefore, the qualification of components based on witness specimens produced within the same job is questionable. This work aims to present a new strategy for the characterization of PBF-LB/M components based on representative specimens. The key assumption is the feasibility of a transfer of the thermal history from a component to a specimen. It is assumed that similar material properties are determined for components and specimens produced adopting a similar thermal history. After the definition of a region of interest in the component, a combination of thermal analyses by means of finite elements and in-situ experimental determination of the thermal history through infrared thermography is used to produce test coupons with a similar thermal history. The effectiveness of the procedure is demonstrated on a pressure vessel for applications in the chemical industry.
KW - Additive manufacturing
KW - Heat accumulation
KW - Thermal history
KW - In situ monitoring
KW - Process simulation
KW - Representative specimens
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-602651
DO - https://doi.org/10.1007/s40964-024-00689-8
SN - 2363-9512
SP - 1
EP - 16
PB - Springer
AN - OPUS4-60265
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Lapenna, Michela
A1 - Tsamos, Athanasios
A1 - Faglioni, Francesco
A1 - Fioresi, Rita
A1 - Zanchetta, Ferdinando
A1 - Bruno, Giovanni
T1 - Geometric deep learning for enhanced quantitative analysis of microstructures in X-ray computed tomography data
JF - Discover Applied Sciences
N2 - Quantitative microstructural analysis of XCT 3D images is key for quality assurance of materials and components. In this paper we implement a Graph Convolutional Neural Network (GCNN) architecture to segment a complex Al-Si Metal Matrix composite XCT volume (3D image). We train the model on a synthetic dataset and we assess its performance on both synthetic and experimental, manually-labeled, datasets. Our simple GCNN shows a comparable performance, measured via the Dice score, to more standard machine learning methods, but uses a greatly reduced number of parameters (less than 1/10 of parameters), features low training time, and needs little hardware resources. Our GCNN thus achieves a cost-effective reliable segmentation.
KW - Geometric deep learning
KW - Segmentation
KW - Microstructure
KW - X-ray computed tomography
KW - Al–Si metal matrix composites
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-602517
DO - https://doi.org/10.1007/s42452-024-05985-0
SN - 3004-9261
VL - 6
IS - 6
SP - 1
EP - 9
AN - OPUS4-60251
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Proll, Günther
A1 - Seidel, Michael
A1 - Schneider, Rudolf
T1 - Moderne bioanalytische Methoden für die schnelle Quantifizierung von Mikroschadstoffen und Pathogenen in Wasser
JF - Mitteilungen der Fachgruppe Umweltchemie und Ökotoxikologie der Gesellschaft Deutscher Chemiker
N2 - Analytische Methoden für die Quantifizierung von Mikroschadstoffen (Synonym für Spurenstoffe) und Pathogenen im Wasser sind eine Grundvoraussetzung für die Umsetzung des Ziels Nr. 6 für Nachhaltige Entwicklung der UN, weltweit sauberes Wasser zur Verfügung zu stellen. Dafür sind schnelle, einfach zu bedienende und kostengünstige Überwachungssysteme notwendig. Antikörperbasierte Biosensoren haben das Potential, z.B. die Eliminationsleistung bezüglich kleiner organischer Moleküle durch die vierte Reinigungsstufe von Kläranlagen vor Ort zu überwachen. Darüber hinaus kommt modernen bioanalytischen Verfahren bei der Quantifizierung von Pathogenen eine immer wichtigere Rolle zu. Neben einer Bestandsaufnahme zu diesen Themen ist es das Ziel dieses Beitrags, die Anwendungsbarrieren von Biosensoren für die Wasseranalytik von Mikroschadstoffen abbauen zu helfen und die Vorzüge moderner bioanalytischer Methoden für die Quantifizierung von Pathogenen aufzuzeigen.
KW - Biosensoren
KW - Antikörper
KW - Abwasser
PY - 2024
SN - 1618-3258
VL - 30
IS - 2
SP - 66
EP - 70
PB - GDCh
CY - Weinheim
AN - OPUS4-60233
LA - deu
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Braymer, Joseph J.
A1 - Stehling, Oliver
A1 - Stümpfig, Martin
A1 - Rösser, Ralf
A1 - Spantgar, Farah
A1 - Blinn, Catharina M.
A1 - Mühlenhoff, Ulrich
A1 - Pierik, Antonio J.
A1 - Lill, Roland
T1 - Requirements for the biogenesis of [2Fe-2S] proteins in the human and yeast cytosol
JF - Proceedings of the National Academy of Sciences
N2 - The biogenesis of iron–sulfur (Fe/S) proteins entails the synthesis and trafficking of Fe/S clusters, followed by their insertion into target apoproteins. In eukaryotes, the multiple steps of biogenesis are accomplished by complex protein machineries in both mitochondria and cytosol. The underlying biochemical pathways have been elucidated over the past decades, yet the mechanisms of cytosolic [2Fe-2S] protein assembly have remained ill-defined. Similarly, the precise site of glutathione (GSH) requirement in cytosolic and nuclear Fe/S protein biogenesis is unclear, as is the molecular role of the GSH-dependent cytosolic monothiol glutaredoxins (cGrxs). Here, we investigated these questions in human and yeast cells by various in vivo approaches. [2Fe-2S] cluster assembly of cytosolic target apoproteins required the mitochondrial ISC machinery, the mitochondrial transporter Atm1/ABCB7 and GSH, yet occurred independently of both the CIA system and cGrxs. This mechanism was strikingly different from the ISC-, Atm1/ABCB7-, GSH-, and CIA-dependent assembly of cytosolic–nuclear [4Fe-4S] proteins. One notable exception to this cytosolic [2Fe-2S] protein maturation pathway defined here was yeast Apd1 which used the CIA system via binding to the CIA targeting complex through its C-terminal tryptophan. cGrxs, although attributed as [2Fe-2S] cluster chaperones or trafficking proteins, were not essential in vivo for delivering [2Fe-2S] clusters to either CIA components or target apoproteins. Finally, the most critical GSH requirement was assigned to Atm1-dependent export, i.e. a step before GSH-dependent cGrxs function. Our findings extend the general model of eukaryotic Fe/S protein biogenesis by adding the molecular requirements for cytosolic [2Fe-2S] protein maturation.
KW - Biokorrosion
KW - Hydrogenasen
KW - Microbially Induced Corrosion
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-602328
DO - https://doi.org/10.1073/pnas.2400740121
VL - 121
IS - 21
SP - 1
EP - 12
PB - Proceedings of the National Academy of Sciences
CY - Washington D.C.
AN - OPUS4-60232
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Gregório, Bruno J.R.
A1 - Ramos, Inês I.
A1 - Marques, Sara S.
A1 - Barreiros, Luísa
A1 - Magalhães, Luís M.
A1 - Schneider, Rudolf
A1 - Segundo, Marcela A.
T1 - Microcarrier-based fluorescent yeast estrogen screen assay for fast determination of endocrine disrupting compounds
JF - Talanta
N2 - The presence of endocrine-disrupting compounds (EDCs) in water poses a significant threat to human and animal health, as recognized by regulatory agencies throughout the world. The Yeast Estrogen Screen (YES) assay is an excellent method to evaluate the presence of these compounds in water due to its simplicity and capacity to assess the bioaccessible forms/fractions of these compounds. In the presence of a compound with estrogenic activity, Saccharomyces cerevisiae cells, containing a lacZ reporter gene encoding the enzyme β-galactosidase, are induced, the enzyme is synthesised, and released to the extracellular medium. In this work, a YES-based approach encompassing the use of a lacZ reporter gene modified strain of S. cerevisiae, microcarriers as solid support, and a fluorescent substrate, fluorescein di-β-D-galactopyranoside, is proposed, allowing for the assessment of EDCs’ presence after only 2 h of incubation. The proposed method provided an EC50 of 0.17 ± 0.03 nM and an LLOQ of 0.03 nM, expressed as 17β-estradiol. The assessment of different EDCs provided EC50 values between 0.16 and 1.2 × 103 nM. After application to wastewaters, similar results were obtained for EDCs screening, much faster, compared to the conventional 45 h spectrophotometric procedure using a commercial kit, showing potential for onsite high-throughput screening of environmental contamination.
KW - Biosensoren
KW - YES assay
KW - Endokrine Disruptoren
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-602315
DO - https://doi.org/10.1016/j.talanta.2024.125665
VL - 271
SP - 1
EP - 7
PB - Elsevier B.V.
CY - Amsterdam
AN - OPUS4-60231
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Guigues, Nathalie
A1 - Uysal, Emrah
A1 - Raveau, Sandrine
A1 - Magar, Jérémie
A1 - Billon, Gabriel
A1 - Kahiluoto, Joonas
A1 - Schneider, Rudolf
A1 - Liv, Lokman
A1 - Gençtürk Tosun, Serap
A1 - Canteau, Gaëlle
A1 - Lalere, Béatrice
T1 - Insights on the validation of alternative tools for water quality monitoring: the case of on-site test kits, portable devices and continuous measuring devices
JF - Accreditation and Quality Assurance
N2 - Alternative Tools (AT) such as on-site test kits, on-site portable devices and continuous measuring devices, are useful to improve water quality assessment under EU directives, and water treatment processes, thus contributing to improving water management, as well as get insights on the dynamic of pollutants within water bodies. Although these tools have clear advantages (e.g. fast response allowing for real-time monitoring, ease-of-use, lower cost), they are perceived as less reliable than conventional analytical methods. Their alternative nature, innovative status, and non-standard operation mode require specific validation strategies that differ significantly from those of conventional analytical methods. Nevertheless, the validation of ATs, especially on-site test kits, portable devices and continuous measuring devices for water quality monitoring is crucial to support their acceptance, promote their use and make their application sustainable. In this paper, a validation procedure in 4 steps is proposed: (1) Comprehensive description of the AT; (2) Assessment of intrinsic metrological performance and operational factors within a single laboratory; (3) Assessment of inter-laboratory performances through an inter-laboratory comparison and, (4) Demonstration of the equivalence of results between the AT and a reference method. This paper discusses each step of the validation procedure, and examples to illustrate critical issues are provided.
KW - Biosensoren
KW - Schnelltests
KW - Validierung
PY - 2024
DO - https://doi.org/10.1007/s00769-023-01570-x
SN - 0949-1775
VL - 29
IS - 7
SP - 163
EP - 173
PB - Springer Science and Business Media LLC
CY - Berlin
AN - OPUS4-60230
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Bosc-Bierne, Gaby
A1 - Ewald, Shireen
A1 - Kreuzer, Oliver J.
A1 - Weller, Michael G.
T1 - Efficient Quality Control of Peptide Pools by UHPLC and Simultaneous UV and HRMS Detection
JF - Separations
N2 - Peptide pools consist of short amino acid sequences and have proven to be versatile tools in various research areas in immunology and clinical applications. They are commercially available in many different compositions and variants. However, unlike other reagents that consist of only one or a few compounds, peptide pools are highly complex products which makes their quality control a major challenge. Quantitative peptide analysis usually requires sophisticated methods, in most cases isotope-labeled standards and reference materials. Usually, this would be prohibitively laborious and expensive. Therefore, an approach is needed to provide a practical and feasible method for quality control of peptide pools. With insufficient quality control, the use of such products could lead to incorrect experimental results, worsening the well-known reproducibility crisis in the biomedical sciences. Here we propose the use of ultra-high performance liquid chromatography (UHPLC) with two detectors, a standard UV detector at 214 nm for quantitative analysis and a high-resolution mass spectrometer (HRMS) for identity confirmation. To be cost-efficient and fast, quantification and identification are performed in one chromatographic run. An optimized protocol is shown, and different peak integration methods are compared and discussed. This work was performed using a peptide pool known as CEF advanced, which consists of 32 peptides derived from cytomegalovirus (CMV), Epstein–Barr virus (EBV) and influenza virus, ranging from 8 to 12 amino acids in length.
N2 - Peptidpools bestehen aus kurzen Aminosäuresequenzen und haben sich als vielseitige Werkzeuge in verschiedenen Forschungsbereichen der Immunologie und bei klinischen Anwendungen erwiesen. Sie sind in vielen verschiedenen Zusammensetzungen und Varianten im Handel erhältlich. Im Gegensatz zu anderen Reagenzien, die nur aus einer oder wenigen Verbindungen bestehen, sind Peptidpools jedoch hochkomplexe Produkte, was ihre Qualitätskontrolle zu einer großen Herausforderung macht. Die quantitative Peptidanalyse erfordert in der Regel ausgefeilte Methoden, in den meisten Fällen isotopenmarkierte Standards und Referenzmaterialien. Dies ist in der Regel sehr aufwändig und teuer. Daher wird ein Ansatz benötigt, der eine praktische und praktikable Methode zur Qualitätskontrolle von Peptidpools bietet. Bei unzureichender Qualitätskontrolle könnte die Verwendung solcher Produkte zu falschen Versuchsergebnissen führen, was das bekannte Problem der Reproduzierbarkeit in den biomedizinischen Wissenschaften noch verschärfen würde. Hier schlagen wir die Verwendung der Ultrahochleistungs-Flüssigkeitschromatographie (UHPLC) mit zwei Detektoren vor, einem Standard-UV-Detektor bei 214 nm für die quantitative Analyse und einem hochauflösenden Massenspektrometer (HRMS) für die Identitätsbestätigung. Um kosteneffizient und schnell zu sein, werden Quantifizierung und Identifizierung in einem einzigen chromatographischen Lauf durchgeführt. Es wird ein optimiertes Protokoll gezeigt, und es werden verschiedene Peak-Integrationsmethoden verglichen und diskutiert. Für diese Arbeit wurde ein Peptidpool verwendet, der als CEF advanced bekannt ist und aus 32 Peptiden besteht, die vom Cytomegalovirus (CMV), Epstein-Barr-Virus (EBV) und Influenzavirus stammen und zwischen 8 und 12 Aminosäuren lang sind.
KW - Synthetic peptides
KW - Quality control
KW - Impurites
KW - Byproducts
KW - Degradation
KW - Mass spectrometry
KW - Orbitrap
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-602299
DO - https://doi.org/10.3390/separations11050156
VL - 11
IS - 5
SP - 1
EP - 18
PB - MDPI AG
CY - Basle, Switzerland
AN - OPUS4-60229
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Schmidt, Stephan
A1 - Hoffmann, Holger
A1 - Garbe, Leif-Alexander
A1 - Harrer, Andrea
A1 - Steiner, Markus
A1 - Himly, Martin
A1 - Schneider, Rudolf
T1 - Re-assessment of monoclonal antibodies against diclofenac for their application in the analysis of environmental waters
JF - Analytical Methods
N2 - The non-steroidal anti-inflammatory drug (NSAID) diclofenac (DCF) is an important environmental contaminant occurring in surface waters all over the world, because, after excretion, it is not adequately removed from wastewater in sewage treatment plants. To be able to monitor this pollutant, highly efficient analytical methods are needed, including immunoassays. In a medical research project, monoclonal antibodies against diclofenac and its metabolites had been produced. Based on this monoclonal anti-DCF antibody, a new indirect competitive enzyme-linked immunosorbent assay (ELISA) was developed and applied for environmental samples. The introduction of a spacer between diclofenac and the carrier protein in the coating conjugate led to higher sensitivity. With a test midpoint of 3 mg L−1 and a measurement range of 1–30 mg L−1, the system is not sensitive enough for direct analysis of surface water. However, this assay is quite robust against matrix influences and can be used for wastewater. Without adjustment of the calibration, organic solvents up to 5%, natural organic matter (NOM) up to 10 mg L−1, humic acids up to 2.5 mg L−1, and salt concentrations up to 6 g L−1 NaCl and 75 mg L−1 CaCl2 are tolerated. The antibody is also stable in a pH range from 3 to 12. Cross-reactivity (CR) of 1% or less was determined for the metabolites 40-hydroxydiclofenac (40-OH-DCF), 5-hydroxydiclofenac (5-OH-DCF), DCF lactam, and other NSAIDs. Relevant cross-reactivity occurred only with an amide derivative of DCF, 6-aminohexanoic acid (DCF-Ahx), aceclofenac (ACF) and DCF methyl ester (DCF-Me) with 150%, 61% and 44%, respectively. These substances, however, have not been found in samples. Only DCF-acyl glucuronide with a cross-reactivity of 57% is of some relevance. For the first time, photodegradation products were tested for cross-reactivity. With the ELISA based on this antibody, water samples were analysed. In sewage treatment plant effluents, concentrations in the range of 1.9–5.2 mg L−1 were determined directly, with recoveries compared to HPLC-MS/MS averaging 136%.
Concentrations in lakes ranged from 3 to 4.4 ng L−1 and were, after pre-concentration, determined with an average recovery of 100%
KW - Antikörper
KW - Immunoassay
KW - Wasser
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-602280
DO - https://doi.org/10.1039/d3ay01333b
VL - 16
IS - 21
SP - 3349
EP - 3363
PB - Royal Society of Chemistry (RSC)
CY - London
AN - OPUS4-60228
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Scholtz, Lena
A1 - Eckert, J. G.
A1 - Graf, Rebecca T.
A1 - Kunst, A.
A1 - Wegner, Karl David
A1 - Bigall, N. C.
A1 - Resch-Genger, Ute
T1 - Correlating semiconductor nanoparticle architecture and applicability for the controlled encoding of luminescent polymer microparticles
JF - Scientific Reports
N2 - Luminophore stained micro- and nanobeads made from organic polymers like polystyrene (PS) are broadly used in the life and material sciences as luminescent reporters, for bead-based assays, sensor arrays, printable barcodes, security inks, and the calibration of fluorescence microscopes and flow cytometers. Initially mostly prepared with organic dyes, meanwhile luminescent core/shell nanoparticles (NPs) like spherical semiconductor quantum dots (QDs) are increasingly employed for bead encoding. This is related to their narrower emission spectra, tuneability of emission color, broad wavelength excitability, and better photostability. However, correlations between particle architecture, morphology, and photoluminescence (PL) of the luminescent nanocrystals used for encoding and the optical properties of the NP-stained beads have been rarely explored. This encouraged us to perform a screening study on the incorporation of different types of luminescent core/shell semiconductor nanocrystals into polymer microparticles (PMPs) by a radical-induced polymerization reaction. Nanocrystals explored include CdSe/CdS QDs of varying CdS shell thickness, a CdSe/ZnS core/shell QD, CdSe/CdS quantum rods (QRs), and CdSe/CdS nanoplatelets (NPLs).
Thereby, we focused on the applicability of these NPs for the polymerization synthesis approach used and quantified the preservation of the initial NP luminescence. The spectroscopic characterization of the resulting PMPs revealed the successful staining of the PMPs with luminescent CdSe/CdS QDs and CdSe/CdS NPLs. In contrast, usage of CdSe/CdS QRs and CdSe QDs with a ZnS shell did not yield luminescent PMPs. The results of this study provide new insights into structure–property relationships between NP stained PMPs and the initial luminescent NPs applied for staining and underline the importance of such studies for the performance optimization of NP-stained beads.
KW - Quantitative spectroscopy
KW - Energy transfer
KW - Synthesis
KW - Surface chemistry
KW - Semiconductor quantum dot
KW - Luminescence
KW - Nano
KW - Particle
KW - Quantum yield
KW - Lifetime
KW - Quality assurance
KW - Polymer particle
KW - Quantum rod
KW - Nanoplatelet
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-602206
DO - https://doi.org/10.1038/s41598-024-62591-1
VL - 14
SP - 1
EP - 16
AN - OPUS4-60220
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Reiber, T.
A1 - Hübner, Oskar
A1 - Dose, C.
A1 - Yushchenko, D. A.
A1 - Resch-Genger, Ute
T1 - Fluorophore multimerization on a PEG backbone as a concept for signal amplification and lifetime modulation
JF - Scientific Reports
N2 - Fluorescent labels have strongly contributed to many advancements in bioanalysis, molecular biology, molecular imaging, and medical diagnostics. Despite a large toolbox of molecular and nanoscale fluorophores to choose from, there is still a need for brighter labels, e.g., for flow cytometry and fluorescence microscopy, that are preferably of molecular nature. This requires versatile concepts for fluorophore multimerization, which involves the shielding of dyes from other chromophores and possible quenchers in their neighborhood. In addition, to increase the number of readout parameters for fluorescence microscopy and eventually also flow cytometry, control and tuning of the labels’ fluorescence lifetimes is desired. Searching for bright multi-chromophoric or multimeric labels, we developed PEGylated dyes bearing functional groups for their bioconjugation and explored their spectroscopic properties and photostability in comparison to those of the respective monomeric dyes for two exemplarily chosen fluorophores excitable at 488 nm. Subsequently, these dyes were conjugated with anti-CD4 and anti-CD8 immunoglobulins to obtain fluorescent conjugates suitable for the labeling of cells and beads. Finally, the suitability of these novel labels for fluorescence lifetime imaging and target discrimination based upon lifetime measurements was assessed. Based upon the results of our spectroscopic studies including measurements of fluorescence quantum yields (QY) and fluorescence decay kinetics we could demonstrate the absence of significant dye-dye interactions and self-quenching in these multimeric labels. Moreover, in a first fluorescence lifetime imaging (FLIM) study, we could show the future potential of this multimerization concept for lifetime discrimination and multiplexing.
KW - Imaging
KW - Quantum yield
KW - Quality assurance
KW - Antibody
KW - Conjugate
KW - Cell
KW - FLIM
KW - PEG
KW - Flow cytometry
KW - Lifetime
KW - Energy transfer
KW - Quantitative spectroscopy
KW - Nano
KW - Particle
KW - Fluorescence
KW - Dye
KW - Amplification
KW - Microscopy
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-602197
DO - https://doi.org/10.1038/s41598-024-62548-4
VL - 14
IS - 1
SP - 1
EP - 11
AN - OPUS4-60219
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Chierici, Andrea
A1 - Cancemi, Salvatore Angelo
A1 - Niederleithinger, Ernst
A1 - Lo Frano, Rosa
T1 - Enhanced radioactive waste drum monitoring: A sensorized LoRa-based network for identification and integrity assessment
JF - Nuclear Engineering and Design
N2 - A reliable monitoring and oversight system is essential to guarantee the safe operation and eventual closure of radioactive waste disposal facilities. With recent technological advancements, there is now the capability to deploy distributed wireless sensor networks that are cost-effective and low in power consumption. Such networks are versatile, finding applications in several civil, environmental, and industrial sectors. This work presents a novel system and method for identifying and continuously monitoring the integrity of stored radioactive waste packages. The proposed approach, developed by the University of Pisa in the context of the H2020 European Project PREDIS, employs a network of wireless node devices, provided with solid-state micro-power radiation detectors tasked with the measurement of gamma-rays and thermal neutrons coming from within cemented waste drums. Collected data are automatically transmitted across the storage site via Long Range radio technology and forwarded to cloud-based or offline platforms, allowing for further visualization, data processing, and safe storage. The system highlights the feasibility of autonomously and passively gathering data from radioactive waste drums over extended distances (more than 250 m in non-line-of-sight conditions), decreasing the reliance
on portable or automated scanning mechanisms. In line with its capability for autonomous, long-range data collection, the system satisfies the requirement for structural integrity, containment, and confinement of packaging throughout both interim and long-term disposal of radioactive wastes, thereby playing a key role in reinforcing the safe management of radioactive waste.
KW - Radioactive waste
KW - Integrity monitoring
KW - Radiation sensors
KW - Cloud storage
KW - LoRaWAN
PY - 2024
DO - https://doi.org/10.1016/j.nucengdes.2024.113231
SN - 0029-5493
VL - 424
SP - 1
EP - 12
PB - Elsevier B.V.
AN - OPUS4-60217
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Albakri, Bashar
A1 - Turski Silva Diniz, Analice
A1 - Benner, Philipp
A1 - Muth, Thilo
A1 - Nakajima, Shinichi
A1 - Favaro, Marco
A1 - Kister, Alexander
ED - Hillman, Robert
T1 - Machine learning-assisted equivalent circuit identification for dielectric spectroscopy of polymers
JF - Electrochimica Acta
N2 - Polymers have become indispensable across fields of application, and understanding their structure–property relationships and dynamic behaviour is essential for performance optimization. Polymer membranes, particularly ion exchange membranes, play a crucial role in renewable energy conversion technologies, fuel cells, solar energy conversion, and energy storage. In this context, broadband dielectric spectroscopy (BDS) offers a powerful, non-destructive approach to investigate the electrical response and relaxation dynamics of polymers. These properties are investigated by parametrizing the system’s impedance response in terms of a network of circuit elements, i.e. the electrical equivalent circuit (EEC), whose impedance resembles the one of the system under investigation. However, the determination of the EEC from BDS data is challenging due to system complexity, interdependencies of circuit elements, and researcher biases. In this work, we propose a novel approach that incorporates a convolutional neural network (CNN) model to predict the EEC topology. By reducing user bias and enhancing data analysis, this approach aims to make BDS accessible to both experienced users and those with limited expertise. We show that the combination of machine learning and BDS provides valuable insights into the dynamic behaviour of polymer membranes, thus facilitating the design and characterization of tailored polymers for various applications. We also show that our model outperforms state-of-the-art machine learning methods with a top-5 accuracy of around 80% for predicting the circuit topology and a parameter fitting error as low as 0.05%.
KW - Polymer membranes
KW - Electrochemical impedance spectroscopy
KW - Broadband dielectric spectroscopy
KW - Deep learning
KW - Machine learning
KW - Equivalent circuit
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-602138
DO - https://doi.org/10.1016/j.electacta.2024.144474
VL - 496
SP - 1
EP - 13
PB - Elsevier Ltd.
AN - OPUS4-60213
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Dace, Elina
A1 - Cascavilla, Alessandro
A1 - Bianchi, Marco
A1 - Chioatto, Elisa
A1 - Zecca, Emy
A1 - Ladu, Luana
A1 - Yilan, Gülsah
T1 - Barriers to transitioning to a circular bio-based economy: Findings from an industrial perspective
JF - Journal of Sustainable Production and Consumption
N2 - The transition from a linear fossil-based to a circular bio-based economy represents an opportunity and a suitable pathway for achieving several sustainable development goals. However, the transition is a complex process since it requires transformative policies, purposeful innovation, access to finance, risk-taking capacity as well as new and sustainable business models and markets. Accordingly, the first step in this transition process is the identification of barriers that are hampering the transition to a sustainable circular bio-based economy. With this motivation in mind, this study reviews grey literature to identify barriers focusing on four critical sectors facing major challenges within the current linear economy and requiring a sustainable transition most urgently: construction, chemicals, plastics, and textile sectors. Employing an adapted STEEP methodology (Social, Technological, Economical, Environmental, Political), a total of 193 different barriers have been identified and clustered under six categories: cultural, technical, economic, environmental, governance, and structural. Regardless of the sector, cultural and structural barriers are identified as the most prominent; the lack of incentives for consumer behaviour change and lack of stakeholder collaboration were the most cited barriers among the literature records. From a value chain perspective, most of the barriers are related to the material processing and product manufacturing stage. Finally, potential solutions, extracted from the grey literature, are proposed to fill the gaps and overcome the identified barriers. Many of the identified barriers are common across the four investigated sectors, indicating the solutions or measures can be applicable in a wider perspective to promote the transition in the right direction.
KW - Circular Bio-based Economy
KW - Barriers
KW - Sustainability
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-602062
DO - https://doi.org/10.1016/j.spc.2024.05.029
VL - 48
SP - 407
EP - 418
PB - Elsevier Ltd.
AN - OPUS4-60206
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Pavasarytė, Lina
A1 - Azevedo do Nascimento, Allana
A1 - Cysne Barbosa, Ana Paula
A1 - Trappe, Volker
A1 - Melo, Daniel
T1 - Effects of particle size and particle concentration of poly (ethylene-co-methacrylic acid) on properties of epoxy resin
JF - Journal of Applied Polymer Sciene
N2 - Self-healing polymers have been developed to improve durability and reduce costs associated with maintenance during service. The addition of thermoplastics to thermosets to produce mendable polymers appears as a promising selfhealing technique. In this study, poly (ethylene-co-methacrylic acid) (EMAA) was added to epoxy resin and the effects of EMAA addition on epoxy properties were evaluated. Specimens with two different contents of thermoplastic and particles sizes were manufactured. A two-level full factorial experimental design was used to evaluate the effect of particle size and particle content on properties of epoxy modified with addition of EMAA. Tensile tests and dynamic mechanical analysis (DMA) were used and the evaluated responses were tensile strength, modulus of elasticity, and glass transition temperature (Tg). X-ray computed tomography (XCT) was used to investigate particle size and concentration after manufacturing. It was found that the particle concentration has greater effects on stress–strain behavior of epoxy while Tg was not significantly affected by neither of the analyzed entrance variables.
KW - Fracture
KW - Self-healing
KW - Epoxy
KW - Thermoplastic
PY - 2024
DO - https://doi.org/10.1002/app.55677
SN - 0021-8995
SP - 1
EP - 14
PB - Wiley online library
AN - OPUS4-60205
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Voss, Heike
A1 - Knigge, Xenia
A1 - Knapic, D.
A1 - Weise, Matthias
A1 - Sahre, Mario
A1 - Hertwig, Andreas
A1 - Sacco, A.
A1 - Rossi, A. M.
A1 - Radnik, Jörg
A1 - Müller, Kai
A1 - Wasmuth, Karsten
A1 - Krüger, Jörg
A1 - Hassel, A. W.
A1 - Hodoroaba, Vasile-Dan
A1 - Bonse, Jörn
T1 - Picosecond laser processing of hierarchical micro–nanostructures on titanium alloy upon pre- and postanodization: morphological, structural, and chemical effects
JF - Physica Status Solidi A
N2 - Recent publications indicate that the order of electrochemical anodization (before or after the laser processing step) plays an important role for the response of bone-forming osteoblasts—an effect that can be utilized for improving permanent dental or removable bone implants. For exploring these different surface functionalities, multimethod morphological, structural, and chemical characterizations are performed in combination with electrochemical pre- and postanodization for two different characteristic microspikes covered by nanometric laser-induced periodic surface structures on Ti–6Al–4V upon irradiation with near-infrared ps-laser pulses (1030 nm wavelength, ≈1 ps pulse duration, 67 and 80 kHz pulse repetition frequency) at two distinct sets of laser fluence and beam scanning parameters. This work involves morphological and topographical investigations by scanning electron microscopy and white light interference microscopy, structural material examinations via X-ray diffraction, and micro-Raman spectroscopy, as well as near-surface chemical analyses by X-ray photoelectron spectroscopy and hard X-ray photoelectron spectroscopy. The results allow to qualify the mean laser ablation depth, assess the spike geometry and surface roughness parameters, and provide new detailed insights into the near-surface oxidation that may affect the different cell growth behavior for pre- or postanodized medical implants.
T2 - 2023 E-MRS Spring Meeting, Symposium L "Making light matter: lasers in material sciences and photonics"
CY - Strasbourg, France
DA - 29.05.2023
KW - Hierarchical micro-nanostructures
KW - Laser-induced periodic surface structures (LIPSS)
KW - Ultrashort laser pulses
KW - Ti-6Al-4V alloy
KW - X-ray photoelectron spectroscopy
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-601962
DO - https://doi.org/10.1002/pssa.202300920
SN - 1862-6319
SP - 1
EP - 11
PB - Wiley-VCH GmbH
CY - Weinheim
AN - OPUS4-60196
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Tabaka, Weronika
A1 - Meinel, Dietmar
A1 - Schartel, Bernhard
T1 - Sacrifice Few to Save Many: Fire Protective Interlayers in Carbon- Fiber-Reinforced Laminates
JF - ACS Omega
N2 - The fire protection of carbon-fiber-reinforced polymer (CFRP) laminates often relies on flame-retardant coatings, but in some applications, their efficacy may diminish upon direct fire exposure due to rapid pyrolysis. This study introduces an innovative approach by integrating protective interlayers within the laminate structure to enhance the fire resistance. Various materials, including ceramic composite WHIPOX, titanium foil, poly(etherimide) (PEI) foil, basalt fibers, rubber mat, and hemp fibers, were selected as protective interlayers. These interlayers were strategically placed within the laminate layout to form a sacrificial barrier, safeguarding the integrity of the composite. Bench-scale fire resistance tests were conducted, where fire (180 kW/m2) was applied directly to the one side of the specimen by a burner while a compressive load was applied at the same time. Results indicate significant prolongation of time to failure for CFRP laminates with protective interlayers, which is up to 10 times longer. This innovative approach represents a potential advance in fire protection strategies for CFRP laminates, offering improved resilience against fire-induced structural failure.
KW - Composites in fire
KW - Fire resistance
KW - Fire retardant interlayers
KW - Laminate design
KW - Carbon fibre reinforced
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-601943
DO - https://doi.org/10.1021/acsomega.4c01408
SN - 2470-1343
VL - 9
IS - 22
SP - 23703
EP - 23712
PB - ACS
AN - OPUS4-60194
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Ladu, Luana
A1 - Koch, Claudia
A1 - Asna Ashari, Parsa
A1 - Blind, K.
A1 - Castka, P.
T1 - Technology adoption and digital maturity in the conformity assessment industry: Empirical evidence from an international study
JF - Global status and trends in Digital Transformation and Conformity Assessment
N2 - Technological innovation and digitalization are transforming industries and organizations worldwide. Digital Maturity Models often serve as a reference point to monitor the digitalization progression through prescribed stages. Yet, little is still understood about (i) how a digital maturity model should be designed and deployed in a specific industry setting and (ii) the association between digital maturity and technology adoption. Building on extant literature and extensive interviews with industry experts, we first develop a digital maturity model in the context of the conformity assessment industry (a globally regulated industry responsible for assessing compliance of organizations with standards and regulations). Second, we implement the model and conduct a survey across 1447 organizations in 15 countries. Our findings reveal that the digital transformation journey of the industry progresses along five stages of maturity (with most organizations in the early/ intermediate stages of digital maturity) with distinctive patterns of technical and managerial practices across all stages. Adoption of technologies is (unsurprisingly) associated with higher digital maturity levels - albeit that association does not hold for complex technologies (such as Blockchain) and is impacted by country specifics (measured by the Digital Skills Gap Index). Our study provides insights into digital maturity and the adoption of technologies in an institutional environment that is highly regulated and conservative, in which high integrity of service provision is primary, and digitalization is a secondary focus of organizations.
KW - Digital Maturity
KW - Standardisation
KW - Digital Maturity Scores
KW - Technology Adoption
KW - Digital Technologies
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-601930
DO - https://doi.org/10.1016/j.techsoc.2024.102564
VL - 77
SP - 1
EP - 12
PB - Elsevier Ltd.
AN - OPUS4-60193
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Junge, Florian
A1 - Wittwer, Philipp
A1 - Sommerfeld, Thomas
A1 - Gehrenkemper, Lennart
A1 - Zoister, Christian
A1 - Nickl, Philip
A1 - Koch, Matthias
A1 - Meermann, Björn
A1 - Haag, Rainer
T1 - Adsorber Charge Dominates over Hydrophobic or Fluorophilic Functionalization in Influencing Adsorption of PFCA onto Polystyrene Resins
JF - Advanced Materials Interfaces
N2 - A systematic series of industrial-relevant polystyrene-based anion exchange resins that are functionalized with hydro- or fluorocarbon chains are compared regarding their adsorption behavior toward perfluorocarboxylic acids (PFCA) in respect to their charge, chain length, and type of chain. The results clearly show the dominance of electrostatic interactions in the adsorption process as uncharged adsorber materials showed no adsorption at all. In contrast, the charged adsorber materials showed in general a PFCA removal of 80% to 30% over the experiment depending on effluent fraction.
Unexpectedly, for perfluorobutanoic acid (PFBA) the highest removal rate is found with consistently >90%. Despite observing significant benefits in the adsorption of PFCA for fluoroalkylated adsorbers in comparison to their non-fluorinated counterparts, this effect of fluoroalkylation is comparatively small and can not be clearly attributed to fluorophilic interactions between the fluoroalkyl chains. These findings help clarifying that the introduction of fluorocarbon moieties in adsorber materials is not necessary in order to remove fluorocarbon molecules from the environment.
KW - PFAS
KW - Remediation
KW - Adsorption
KW - Fluorophilic interactions
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-601883
DO - https://doi.org/10.1002/admi.202400199
SN - 2196-7350
SP - 1
EP - 10
PB - John Wiley & Sons
CY - Hoboken, New Jersey, USA
AN - OPUS4-60188
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Schilling, Markus
A1 - Niebergall, Ute
A1 - Marschall, Niklas
A1 - Meinel, Dietmar
A1 - Böhning, Martin
T1 - Relation of craze to crack length during slow crack growth phenomena in high‐density polyethylene
JF - Polymer Engineering & Science
N2 - The craze‐crack mechanism occurring in high‐density polyethylene (HDPE) causing slow crack growth and environmental stress cracking is investigated in detail with respect to the relation of crack length and the related craze zone. This is essential for the understanding of the resulting features of the formed fracture surface and their interpretation in the context of the transition from crack propagation to ductile shear deformation. It turns out that an already formed craze zone does not inevitably result in formation of a propagating crack, but could also undergo ductile failure. For the examination, the full notch creep test (FNCT) was employed with a subsequent advanced fracture surface analysis that was performed using various imaging techniques: light microscopy, laser scanning microscopy, scanning electron microscopy, and X‐ray micro computed tomography scan. FNCT specimens were progressively damaged for increasing durations under standard test conditions applying Arkopal, the standard surfactant solution, and biodiesel as test media were used to analyze the stepwise growth of cracks and crazes. From considerations based on well‐established fracture mechanics approaches, a theoretical correlation between the length of the actual crack and the length of the preceding craze zone was established that could be evidenced and affirmed by FNCT fracture surface analysis. Moreover, the yield strength of a HDPE material exposed to a certain medium as detected by a classic tensile test was found to be the crucial value of true stress to induce the transition from crack propagation due to the craze‐crack mechanism to shear deformation during FNCT measurements.
Highlights
- Progress of crack formation in high‐density polyethylene is analyzed by different imaging techniques
- Determined growth rates depend on distinction between craze zone and crack
- The ratio of the present crack to the anteceding craze zone is validated theoretically
- The transition from crack propagation to ductile shear deformation is identified
- An already formed craze zone may still fail by ductile mechanisms
KW - Craze-crack mechanism
KW - Environmental stress cracking (ESC)
KW - Full notch creep test (FNCT)
KW - Laser scanning microscopy (LSM)
KW - Slow crack growth (SCG)
KW - X-ray computed tomography (CT)
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-601831
DO - https://doi.org/10.1002/pen.26698
SN - 1548-2634
VL - 64
IS - 6
SP - 2387
EP - 2403
PB - Wiley
AN - OPUS4-60183
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Bordeenithikasem, Punnathat
A1 - Carpenter, Kalind C.
A1 - Hofmann, Douglas C.
A1 - White, Victor E.
A1 - Yee, Karl Y.
A1 - Rizzardi, Quentin
A1 - Maher, Jacob
A1 - Maaß, Robert
T1 - Miniaturized bulk metallic glass gripping structures for robotic mobility platforms
JF - Acta Astronautica
N2 - Advancements in bulk metallic glass thermoplastic forming unleash the potential to fabricate microscale metallic features with unparalleled precision and durability, i.e. microspine gripping structures for mobility platforms on planetary or in-space robots. Four designs of grippers were fabricated and rigorously tested. Coefficient of friction on four test surfaces were measured and compared to SiC paper and Velcro. The hardness and elasticity of the bulk metallic glasses make them a game-changer in the field, offering a superior alternative to conventional nonmetallic grippers.
KW - Bulk metallic glasses
KW - Thermoplastic forming
KW - Mobility
KW - Microspine
PY - 2024
DO - https://doi.org/10.1016/j.actaastro.2024.03.040
SN - 0094-5765
VL - 219
SP - 399
EP - 407
PB - Elsevier Ltd.
CY - Amsterdam, Niederlande
AN - OPUS4-60182
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Dzugan, J.
A1 - Lucon, E.
A1 - Koukolikova, M.
A1 - Li, Y.
A1 - Rzepa, S.
A1 - Yasin, M.S.
A1 - Shao, S.
A1 - Shamsaei, N.
A1 - Seifi, M.
A1 - Lodeiro, M.
A1 - Lefebvre, F.
A1 - Mayer, U.
A1 - Olbricht, J.
A1 - Houska, M.
A1 - Mentl, V.
A1 - You, Z.
T1 - ASTM interlaboratory study on tensile testing of AM deposited and wrought steel using miniature specimens
JF - Theoretical and Applied Fracture Mechanics
N2 - An interlaboratory study, involving eigth international laboratories and coordinated by COMTES FHT (Czech Republic), was conducted to validate tensile measurements obtained using miniature specimens on additively manufactured (AM) components and artifacts. In addition to AM 316L stainless steel (316L SS), a wrought highstrength steel (34CrNiMo6V, equivalent to AISI 4340) was also used. Based on the results, a precision statement in accordance with ASTM E691 standard practice was developed, intended for inclusion in a proposed annex to the ASTM E8/E8M tension testing method. The primary outcomes of the study highlighted the agreement between yield and tensile strength measured from miniature and standard-sized tensile specimens. Furthermore, most tensile properties exhibited similar standard deviations, offering users insight into the efficacy of miniature specimen applications.
KW - 316L stainless steel
KW - Additive manufacturing
KW - High-strength steel
KW - Miniature specimens
KW - Tensile tests
PY - 2024
DO - https://doi.org/10.1016/j.tafmec.2024.104410
SN - 0167-8442
VL - 131
SP - 1
EP - 13
PB - Elsevier B.V.
AN - OPUS4-60180
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Epping, Ruben
A1 - Lisec, Jan
A1 - Koch, Matthias
T1 - Changes in Black Truffle (Tuber melanosporum) Aroma during Storage under Different Conditions
JF - Journal of Fungi
N2 - The enticing aroma of truffles is a key factor for their culinary value. Although all truffle species tend to be pricy, the most intensely aromatic species are the most sought after. Research into the aroma of truffles encompasses various disciplines including chemistry, biology, and sensory science. This study focusses on the chemical composition of the aroma of black truffles (Tuber melanosporum) and the changes occurring under different storage conditions. For this, truffle samples were stored under different treatments, at different temperatures, and measured over a total storage time of 12 days. Measurements of the truffle aroma profiles were taken with SPME/GC–MS at regular intervals. To handle the ample data collected, a systematic approach utilizing multivariate data analysis techniques was taken. This approach led to a vast amount of data which we made publicly available for future exploration. Results reveal the complexity of aroma changes, with 695 compounds identified, highlighting the need for a comprehensive understanding. Principal component analyses offer initial insights into truffle composition, while individual compounds may serve as markers for age (formic acid, 1-methylpropyl ester), freshness (2-Methyl-1-propanal; 1-(methylthio)-propane), freezing (tetrahydrofuran), salt treatment (1-chloropentane), or heat exposure (4-hydroxy-3-methyl-2-butanone). This research suggests that heat treatment or salt contact significantly affects truffle aroma, while freezing and cutting have less pronounced effects in comparison. The enrichment of compounds showing significant changes during storage was investigated with a metabolomic pathway analysis. The involvement of some of the enriched compounds on the pyruvate/glycolysis and sulfur pathways was shown.
KW - Mass Spectrometry
KW - Metabolomics
KW - Tuber melanosporum
KW - Truffle Aroma
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-601731
DO - https://doi.org/10.3390/jof10050354
VL - 10
IS - 5
SP - 1
EP - 22
PB - MDPI
AN - OPUS4-60173
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Salari, Farid
A1 - Zocca, Andrea
A1 - Bosetti, Paolo
A1 - Hlaváček, Petr
A1 - Italiano, Antonino
A1 - Gobbin, Filippo
A1 - Colombo, Paolo
A1 - Kühne, Hans-Carsten
A1 - Sglavo, Vincenzo M.
T1 - Powder-bed 3D printing by selective activation of magnesium phosphate cement: Determining significant processing parameters and their effect on mechanical strength
JF - Open Ceramics
N2 - The present work addresses powder bed binder jetting additive manufacturing by selective magnesium phosphate cement activation. Despite the potential of this technology to aid the digitalization of the construction industry, the effect of processing parameters on the mechanical performance of printed materials has not yet been studied to generate a guideline for the further development of the technology. Statistical methodologies were used to screen the effect of four printing process parameters (printing speed, layer thickness, raster angle, and build direction on flexural and compressive strength). As the exploited technology works with constant fluid pressure, the physical interpretation of the effect of each factor can be considered taking into account the interactions between the binder materials in the powder bed. Analysis of variance (ANOVA) indicated that printing speed and layer thickness significantly affect mechanical performances. Furthermore, the layout of samples for the printing process is preferable to be parallel the printhead movement. An anisotropic behavior was observed, and the samples subjected to compressive forces parallel to the layer plane possessed lower strength values. This effect can be interpreted as a result of a weak area of low density in between layers, leading to a pronounced delamination under compression. Even though the strength of the printed material is not suitable for a structural concrete, it can be marginally improved by design of experiment and optimized for non-structural applications, such as for porous artificial stone. Design of experiment coupled with ANOVA methods can be used in the future to support the development of novel material mixtures, thus expanding the fields of application of this novel additive manufacturing technology.
KW - Concrete 3D-printing
KW - Particle-bed binder jetting
KW - Design of experiment
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-601654
DO - https://doi.org/10.1016/j.oceram.2024.100609
VL - 18
SP - 1
EP - 11
PB - Elsevier B.V.
AN - OPUS4-60165
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Stargardt, Patrick
A1 - Bresch, Sophie
A1 - Falkenberg, Rainer
A1 - Mieller, Björn
T1 - Effect of Reaction Layers on Internal Stresses in Co‐Fired Multilayers of Calcium Manganate and Calcium Cobaltite
JF - physica status solidi (a)
N2 - A widespread recovery of waste heat requires a cost‐effective production of thermoelectric generators. Thermoelectric oxides are predestined for use at high temperatures. For manufacturing reasons, a multilayer generator design will be easily scalable and cost‐effective. To evaluate the potential of ceramic multilayer technology for that purpose, a multilayer of the promising thermoelectric oxides calcium cobaltite (Ca3Co4O9), calcium manganate (CMO, CaMnO3), and glass–ceramic insulation layers is fabricated. Cracks and reaction layers at the interfaces are observed in the microstructure. The compositions of these reaction layers are identified by energy‐dispersive X‐ray spectroscopy and X‐ray diffraction. Mechanical and thermal properties of all layers are compiled from literature or determined by purposeful sample preparation and testing. Based on this data set, the internal stresses in the multilayer after co‐firing are calculated numerically. It is shown that tensile stresses in the range of 50 MPa occur in the CMO layers. The reaction layers have only a minor influence on the level of these residual stresses. Herein, it is proven that the material system is basically suitable for multilayer generator production, but that the co‐firing process and the layer structure must be adapted to improve densification and reduce the tensile stresses in the CMO.
KW - Ceramic multilayers
KW - Co-firings
KW - Internal stresses
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-601626
DO - https://doi.org/10.1002/pssa.202300956
SP - 1
EP - 9
PB - Wiley VHC-Verlag
AN - OPUS4-60162
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Bauer, L.J.
A1 - Wieder, Frank
A1 - Truong, V.
A1 - Förste, F.
A1 - Wagener, Y.
A1 - Jonas, A.
A1 - Praetz, S:
A1 - Schlesiger, C.
A1 - Kupsch, Andreas
A1 - Müller, B.R.
A1 - Kanngießer, B.
A1 - Zaslansky, P.
A1 - Mantouvalou, I.
T1 - Absorption Correction for 3D Elemental Distributions of Dental Composite Materials Using Laboratory Confocal Micro-X-ray Fluorescence Spectroscopy
JF - Analytical Chemistry
N2 - Confocal micro-X-ray fluorescence (micro-XRF) spectroscopy facilitates three-dimensional (3D) elemental imaging of heterogeneous samples in the micrometer range. Laboratory setups using X-ray tube excitation render the method accessible for diverse research fields but interpretation of results and quantification remain challenging. The attenuation of X-rays in composites depends on the photon energy as well as on the composition and density of the material. For confocal micro-XRF, attenuation severely impacts elemental distribution information, as the signal from deeper layers is distorted by superficial layers. Absorption correction and quantification of fluorescence measurements in heterogeneous composite samples have so far not been reported. Here, an absorption correction approach for confocal micro-XRF combining density information from microcomputed tomography (micro-CT) data with laboratory X-ray absorption spectroscopy (XAS) and synchrotron transmission measurements is presented. The energy dependency of the probing volume is considered during the correction. The methodology is demonstrated on a model composite sample consisting of a bovine tooth with a clinically used restoration material.
KW - Micro X-ray fluorescence spectroscopy
KW - Dental composite materials
KW - Computed tomography
KW - Absorption correction
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-601630
DO - https://doi.org/10.1021/acs.analchem.4c00116
SN - 0003-2700
SN - 1520-6882
VL - 96
IS - 21
SP - 8441
EP - 8449
PB - American Chemical Society Publications
CY - Washington, DC
AN - OPUS4-60163
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - López-Iglesias, C.
A1 - Markovina, A.
A1 - Nirmalananthan-Budau, N.
A1 - Resch-Genger, Ute
A1 - Klinger, D.
T1 - Optically monitoring the microenvironment of a hydrophobic cargo in amphiphilic nanogels: influence of network composition on loading and release
JF - Nanoscale
N2 - Amphiphilic nanogels (ANGs) are promising carriers for hydrophobic cargos such as drugs, dyes, and catalysts.
Loading content and release kinetics of these compounds are controlled by type and number of hydrophobic groups in the amphiphilic copolymer network. Thus, understanding the interactions between cargo and colloidal carrier is mandatory for a tailor-made and cargo-specific ANG design. To systematically explore the influence of the network composition on these interactions, we prepared a set of ANGs of different amphiphilicity and loaded these ANGs with varying concentrations of the solvatochromic dye Nile Red (NR). Here, NR acts as a hydrophobic model cargo to optically probe the polarity of its microenvironment. Analysis of the NR emission spectra as well as measurements of the fluorescence quantum yields and decay kinetics revealed a decrease in the polarity of the NR microenvironment with increasing hydrophobicity of the hydrophobic groups in the ANG network and dye–dye interactions at higher loading concentrations. At low NR concentrations, the hydrophobic cargo NR is encapsulated in the hydrophobic domains. Increasing NR concentrations resulted in probe molecules located in a more hydrophilic environment, i.e., at the nanodomain border, and favored dye–dye interactions and NR aggregation.
These results correlate well with release experiments, indicating first NR release from more hydrophilic network locations. Overall, our findings demonstrate the importance to understand carrier–drug interactions for efficient loading and controlled release profiles in amphiphilic nanogels.
KW - Particle
KW - Energy transfer
KW - Limit of detection
KW - Polymer
KW - Luminescence
KW - Quantitative spectroscopy
KW - Nano
KW - Quantum yield
KW - Lifetime
KW - Quality assurance
KW - Dye
KW - Probe
KW - Sensor
KW - Nile Red
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-601603
DO - https://doi.org/10.1039/d4nr00051j
SN - 2040-3364
IS - 16
SP - 9525
EP - 9535
PB - The Royal Society of Chemistry
AN - OPUS4-60160
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Kianinejad, Kaveh
A1 - Darvishi Kamachali, Reza
A1 - Khedkar, Abhinav
A1 - Manzoni, Anna
A1 - Agudo Jácome, Leonardo
A1 - Schriever, Sina
A1 - Saliwan Neumann, romeo
A1 - Megahed, Sandra
A1 - Heinze, Christoph
A1 - Kamrani, Sepideh
A1 - Fedelich, Bernard
T1 - Creep anisotropy of additively manufactured Inconel-738LC: Combined experiments and microstructure-based modeling
JF - Materials Science and Engineering: A
N2 - The current lack of quantitative knowledge on processing-microstructure–property relationships is one of the major bottlenecks in today’s rapidly expanding field of additive manufacturing. This is centrally rooted in the nature of the processing, leading to complex microstructural features. Experimentally-guided modeling can offer reliable solutions for the safe application of additively manufactured materials. In this work, we combine a set of systematic experiments and modeling to address creep anisotropy and its correlation with microstructural characteristics in laser-based powder bed fusion (PBF-LB/M) additively manufactured Inconel-738LC (IN738LC). Three sample orientations (with the tensile axis parallel, perpendicular, and 45° tilted, relative to the building direction) are crept at 850 °C, accompanied by electron backscatter secondary diffraction (EBSD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM) investigations. A crystal plasticity (CP) model for Ni-base superalloys, capable of modeling different types of slip systems, is developed and combined with various polycrystalline representative volume elements (RVEs) built on the experimental measurements. Besides our experiments, we verify our modeling framework on electron beam powder bed fusion (PBF-EB/M) additively manufactured Inconel-738LC. The results of our simulations show that while the crystallographic texture alone cannot explain the observed creep anisotropy, the superlattice extrinsic stacking faults (SESF) and related microtwinning slip systems play major roles as active deformation mechanisms. We confirm this using TEM investigations, revealing evidence of SESFs in crept specimens. We also show that the elongated grain morphology can result in higher creep rates, especially in the specimens with a tilted tensile axis.
KW - Additive manufactured Ni-base superalloys
KW - Creep
KW - Crystal plasticity
KW - Superlattice extrinsic stacking faults
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-601576
DO - https://doi.org/10.1016/j.msea.2024.146690
SN - 0921-5093
VL - 907
SP - 1
EP - 16
PB - Elsevier B.V.
AN - OPUS4-60157
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Barkeshli, Mandana
A1 - Stephan, Ina
A1 - Shevchuk, Ivan
A1 - Soltani, Mojtaba
T1 - Characteristics of Sizing Materials Used in Persian Medieval Manuscripts: Physical, Optical, Spectral Imaging, and Fungicidal Properties
JF - Studies in Conservation
N2 - In this study, we investigated the diverse range of materials used for sizing in Iranian paper manuscripts during the Timurid (fifteenth century) to Safavid (sixteenth century) and Qajar (nineteenth century) periods. Our approach combined historical analysis with scientific examination of reconstructed sizings. We reconstructed 15 sizing materials based on identified Persian historical recipes and analysed their physical, optical, and spectral characteristics. Additionally, we assessed their behaviour against the mould fungus Aspergillus flavus. The results revealed distinctive properties for each sizing material, shedding light on their potential applications in paper preservation. Furthermore, our investigation demonstrated variations in hygroscopicity, thickness, grammage, and ash content post-sizing. The sizing materials also exhibited different effects on paper reflectance properties. Additionally, our study revealed insights into the impact of sizing on burnished papers, indicating that the mechanical process of burnishing did not significantly alter the chemical composition or spectral properties of the paper, with only minor changes in brightness observed in specific cases. All tested sizing materials supported varying levels of mould growth, indicating potential implications for paper conservation. Our findings provide valuable insights into the historical practices of Iranian paper sizing and offer practical considerations for the preservation of paper manuscripts.
KW - Paper sizings
KW - Persian historical recipes
KW - Physical and optical characteristics
KW - Fungicidal property
KW - Spectral imaging
PY - 2024
DO - https://doi.org/10.1080/00393630.2024.2342647
SP - 1
EP - 18
PB - Informa UK Limited
AN - OPUS4-60159
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Vogel, K.
A1 - Sieg, T.
A1 - Veh, G.
A1 - Fiedler, B.
A1 - Moran, T.
A1 - Peter, M.
A1 - Rottler, E.
A1 - Bronstert, A.
T1 - Natural Hazards in a Changing World: Methods for Analyzing Trends and Non‐Linear Changes
JF - Earth's Future
N2 - Estimating the frequency and magnitude of natural hazards largely hinges on stationary models, which do not account for changes in the climatological, hydrological, and geophysical baseline conditions. Using five diverse case studies encompassing various natural hazard types, we present advanced statistical and machine learning methods to analyze and model transient states from long‐term inventory data. A novel storminess metric reveals increasing European winter windstorm severity from 1950 to 2010. Non‐stationary extreme value models quantify trends, seasonal shifts, and regional differences in extreme precipitation for Germany between 1941 and 2021. Utilizing quantile sampling and empirical mode decomposition on 148 years of daily weather and discharge data in the European Alps, we assess the impacts of changing snow cover, precipitation, and anthropogenic river network modifications on river runoff. Moreover, a probabilistic framework estimates return periods of glacier lake outburst floods in the Himalayas, demonstrating large differences in 100‐year flood levels. Utilizing a Bayesian change point algorithm, we track the onset of increased seismicity in the southern central United States and find correlation with wastewater injections into deep wells. In conclusion, data science reveals transient states for very different natural hazard types, characterized by diverse forms of change, ranging from gradual trends to sudden change points and from altered seasonality to overall intensity variations. In synergy with the physical understanding of Earth science, we gain important new insights into the dynamics of the studied hazards and their possible mechanisms.
KW - Natural hazards
KW - Time dependent modeling
KW - Transient state
KW - Data science
KW - Climate change
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-601540
DO - https://doi.org/10.1029/2023EF003553
VL - 12
IS - 5
SP - 1
EP - 29
PB - American Geophysical Union (AGU)
AN - OPUS4-60154
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Becker, Tina
A1 - Stark, T.
A1 - Arduini, M.
A1 - Manara, J.
A1 - Altenburg, Simon
T1 - Knowing the spectral directional emissivity of 316L and AlSi10Mg PBF-LB/M surfaces: Gamechanger for quantitative in situ monitoring
JF - Progress in additive manufacturing
N2 - For a deep process understanding of the laser powder bed fusion process (PBF-LB/M), recording of the occurring surface temperatures is of utmost interest and would help to pave the way for reliable process monitoring and quality assurance. A notable number of approaches for in-process monitoring of the PBF-LB/M process focus on the monitoring of thermal process signatures. However, due to the elaborate calibration effort and the lack of knowledge about the occurring spectral directional emissivity, only a few approaches attempt to measure real temperatures. In this study, to gain initial insights into occurring in the PBF-LB/M process, measurements on PBF-LB/M specimens and metal powder specimens were performed for higher temperatures up to T = 1290 °C by means of the emissivity measurement apparatus (EMMA) of the Center for Applied Energy Research (CAE, Wuerzburg, Germany). Also, measurements at ambient temperatures were performed with a suitable measurement setup. Two different materials—stainless steel 316L and aluminum AlSi10Mg—were examined. The investigated wavelength λ ranges from the visible range (λ-VIS= 0.40–0.75 µm) up to the infrared, λ = 20 µm. The influence of the following factors were investigated: azimuth angle φ, specimen temperature TS, surface texture as for PBF-LB/M surfaces with different scan angles α, and powder surfaces with different layer thicknesses t.
T2 - Rapid.Tech 3D 2024
CY - Erfurt, Germany
DA - 14.05.2024
KW - PBF-LB/M
KW - In situ monitoring
KW - Emissivity
KW - Additive manufacturing
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-601471
DO - https://doi.org/10.1007/s40964-024-00665-2
SN - 2363-9520
SP - 1
EP - 10
PB - Springer
CY - Cham, Switzerland
AN - OPUS4-60147
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Groschke, Matthias
A1 - Becker, Roland
T1 - Comparison of carrier gases for the separation and quantification of mineral oil hydrocarbon (MOH) fractions using online coupled high performance liquid chromatography-gas chromatography-flame ionisation detection
JF - Journal of chromatography A
N2 - On-line coupled high performance liquid chromatography-gas chromatography-flame ionisation detection (HPLC-GC-FID) was used to compare the effect of hydrogen, helium and nitrogen as carrier gases on the chromatographic characteristics for the quantification of mineral oil hydrocarbon (MOH) traces in food related matrices. After optimisation of chromatographic parameters nitrogen carrier gas exhibited characteristics equivalent to hydrogen and helium regarding requirements set by current guidelines and standardisation such as linear range, quantification limit and carry over. Though nitrogen expectedly led to greater peak widths, all required separations of standard compounds were sufficient and humps of saturated mineral oil hydrocarbons (MOSH) and aromatic mineral oil hydrocarbons (MOAH) were appropriate to enable quantitation similar to situations where hydrogen or helium had been used. Slightly increased peak widths of individual hump components did not affect shapes and widths of the MOSH and MOAH humps were not significantly affected by the use of nitrogen as carrier gas. Notably, nitrogen carrier gas led to less solvent peak tailing and smaller baseline offset. Overall, nitrogen may be regarded as viable alternative to hydrogen or helium and may even extend the range of quantifiable compounds to highly volatile hydrocarbon eluting directly after the solvent peak.
KW - Mineral oil hydrocarobons
KW - Food
KW - Liquid chromatography
KW - Gas chromatography
KW - MOSH/MOAH
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-601450
DO - https://doi.org/10.1016/j.chroma.2024.464946
SN - 0021-9673
VL - 1726
SP - 1
EP - 7
PB - Elsevier
CY - New York, NY
AN - OPUS4-60145
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Nag, Sayak
A1 - Emmerling, Franziska
A1 - Tothadi, Srinu
A1 - Bhattacharya, Biswajit
A1 - Ghosh, Soumyajit
T1 - Distinct photomechanical responses of two new 1,3-dimethylbarbituric acid derivative crystals
JF - CrystEngComm
N2 - We demonstrate two distinct photomechanical responses (i.e. photomechanical bending and photosalient bursting) of two new 1,3-dimethylbarbituric acid derivative crystals based on tailoring their substituents and the modulation of their spacers.
KW - Crystal engineering
KW - Fexible crystals
PY - 2024
DO - https://doi.org/10.1039/D4CE00233D
SP - 1
EP - 12
PB - Royal Society of Chemistry (RSC)
AN - OPUS4-60141
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Kunkel, Benny
A1 - Seeburg, Dominik
A1 - Kabelitz, Anke
A1 - Witte, Steffen
A1 - Gutmann, Torsten
A1 - Breitzke, Hergen
A1 - Buntkowsky, Gerd
A1 - Guilherme Buzanich, Ana
A1 - Wohlrab, Sebastian
T1 - Highly productive V/Zn-SiO2 catalysts for the selective oxidation of methane
JF - Catalysis Today
N2 - The production of formaldehyde on industrial scale requires huge amounts of energy due to the involvement of reforming processes in combination with the demand in the megaton scale. Hence, a direct route for the transformation of (bio)methane to formaldehyde would decrease costs and puts less pressure on the environment. Herein, we report on the use of zinc modified silicas as possible support materials for vanadium catalysts and the resulting consequences for the performance in the selective oxidation of methane to formaldehyde. After optimization of the Zn content and reaction conditions, a remarkably high space-time yield of 12.4 kgCH2O⋅kgcat − 1 ⋅h− 1 was achieved. As a result of the extensive characterization by means of UV–vis, Raman, XANES and NMR spectroscopy it was found that vanadium is in the vicinity of highly dispersed zinc atoms which promote the formation of active vanadium species as supposed by theoretical calculations. This work presents a further step of catalyst development towards direct industrial methane conversion which may help to overcome current limitations in the future.
KW - Catalysis
KW - XANES
KW - Selective oxidation
PY - 2024
DO - https://doi.org/10.1016/j.cattod.2024.114643
SN - 0920-5861
VL - 432
SP - 1
EP - 13
PB - Elsevier B.V.
AN - OPUS4-60137
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Grundmann, Jana
A1 - Bodermann, Bernd
A1 - Ermilova, Elena
A1 - Weise, Matthias
A1 - Hertwig, Andreas
A1 - Klapetek, Petr
A1 - Rafighdoost, Jila
A1 - Pereira, Silvania F.
T1 - Optical and tactile measurements on SiC sample defects
JF - Journal of Sensors and Sensor Systems
N2 - Abstract. In power electronics, compound semiconductors with large bandgaps, like silicon carbide (SiC), are increasingly being used as material instead of silicon. They have a lot of advantages over silicon but are also intolerant of nanoscale material defects, so that a defect inspection with high accuracy is needed. The different defect types on SiC samples are measured with various measurement methods, including optical and tactile methods. The defect types investigated include carrots, particles, polytype inclusions and threading dislocations, and they are analysed with imaging ellipsometry, coherent Fourier scatterometry (CFS), white light interference microscopy (WLIM) and atomic force microscopy (AFM). These different measurement methods are used to investigate which method is most sensitive for which type of defect to be able to use the measurement methods more effectively. It is important to be able to identify the defects to classify them as critical or non-critical for the functionality of the end product. Once these investigations have been completed, the measurement systems can be optimally distributed to the relevant defects in further work to realize a hybrid analysis of the defects. In addition to the identification and classification of defects, such a future hybrid analysis could also include characterizations, e.g. further evaluation of ellipsometric data by using numerical simulations.
KW - Compound semiconductors
KW - Hybrid metrology
KW - Material defects
KW - Spectroscopic Ellipsometry
KW - Scanning Probe Microscopy
KW - White-light Interference Microscopy
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-601220
DO - https://doi.org/10.5194/jsss-13-109-2024
SN - 2194-878X
VL - 13
IS - 1
SP - 109
EP - 121
PB - Copernicus GmbH
AN - OPUS4-60122
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Poka, Konstantin
A1 - Ali, Sozol
A1 - Saeed, Waleed
A1 - Merz, Benjamin
A1 - Epperlein, Martin
A1 - Hilgenberg, Kai
T1 - Design and implementation of a machine log for PBF-LB/M on basis of IoT communication architectures and an ETL pipeline
JF - Progress in Additive Manufacturing
N2 - AbstractPowder Bed Fusion with Laser Beam of Metals (PBF-LB/M) has gained more industrial relevance and already demonstrated applications at a small series scale. However, its widespread adoption in various use cases faces challenges due to the absence of interfaces to established Manufacturing Execution Systems (MES) that support customers in the predominantly data-driven quality assurance. Current state-of-the-art PBF-LB/M machines utilize communication architectures, such as OPC Unified Architecture (OPC UA), Message Queuing Telemetry Transport (MQTT) and Representational State Transfer Application Programming Interface (REST API). In the context of the Reference Architecture Model Industry 4.0 (RAMI 4.0) and the Internet of Things (IoT), the assets, particularly the physical PBF-LB/M machines, already have an integration layer implemented to communicate data such as process states or sensor values. Missing is an MES component acting as a communication and information layer. To address this gap, the proposed Extract Transform Load (ETL) pipeline aims to extract relevant data from the fabrication of each build cycle down to the level of scan vectors and additionally to register process signals. The suggested data schema for archiving each build cycle adheres to all terms defined by ISO/TC 261—Additive Manufacturing (AM). In relation to the measurement frequency, all data are reorganized into entities, such as the AM machine, build cycle, part, layer, and scan vector. These scan vectors are stored in a runtime-independent format, including all metadata, to be valid and traceable. The resulting machine log represents a comprehensive documentation of each build cycle, enabling data-driven quality assurance at process level.
KW - FAIR data
KW - Data-driven quality assurance
KW - Laser powder bed fusion
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-601256
DO - https://doi.org/10.1007/s40964-024-00660-7
SN - 2363-9512
SP - 1
EP - 12
PB - Springer Science and Business Media LLC
AN - OPUS4-60125
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - He, Zhiming
A1 - Dechesne, Arnaud
A1 - Schreiber, Frank
A1 - Zhu, Yong-Guan
A1 - Larsson, Joakim
A1 - Smets, Barth
T1 - Understanding Stimulation of Conjugal Gene Transfer by Nonantibiotic Compounds: How Far Are We?
JF - Environmental Science & Technology
N2 - A myriad of nonantibiotic compounds is released into the environment, some of which may contribute to the dissemination of antimicrobial resistance by stimulating conjugation. Here, we analyzed a collection of studies to (i) identify patterns of transfer stimulation across groups and concentrations of chemicals, (ii) evaluate the strength of evidence for the proposed mechanisms behind conjugal stimulation, and (iii) examine the plausibility of alternative mechanisms. We show that stimulatory nonantibiotic compounds act at concentrations from 1/1000 to 1/10 of the minimal inhibitory concentration for the donor strain but that stimulation is always modest (less than 8-fold). The main proposed mechanisms for stimulation via the reactive oxygen species/SOS cascade and/or an increase in cell membrane permeability are not unequivocally supported by the literature. However, we identify the reactive oxygen species/SOS cascade as the most likely mechanism. This remains to be confirmed by firm molecular evidence. Such evidence and more standardized and high-throughput conjugation assays are needed to create technologies and solutions to limit the stimulation of conjugal gene transfer and contribute to mitigating global antibiotic resistance.
KW - Antibiotic resistance
KW - Horizontal gene transfer
KW - Conjugation
KW - Chemicals
PY - 2024
DO - https://doi.org/10.1021/acs.est.3c06060
SP - 1
EP - 14
PB - ACS Publications
AN - OPUS4-60105
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Schlögl, Johanna
A1 - Goldammer, Ole
A1 - Bader, Julia
A1 - Emmerling, Franziska
A1 - Riedel, Sebastian
T1 - Introducing AFS ([Al(SO3F)3]x) – a thermally stable, readily available, and catalytically active solid Lewis superacid
JF - Chemical Science
N2 - This paper introduces the thermally stable, solid Lewis superacid aluminium tris(fluorosulfate) (AFS), that is easy-to-synthesize from commercially available starting materials. Its applicability, e.g. in catalytic C–F bond activations, is shown.
KW - Lewis Acid
KW - C-F activation
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-601001
DO - https://doi.org/10.1039/D4SC01753F
SN - 2041-6520
SP - 1
EP - 7
PB - Royal Society of Chemistry (RSC)
AN - OPUS4-60100
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Fiedler, Saskia
A1 - Frenzel, Florian
A1 - Würth, Christian
A1 - Tavernaro, Isabella
A1 - Grüne, M.
A1 - Schweizer, S.
A1 - Engel, A.
A1 - Resch-Genger, Ute
T1 - Interlaboratory Comparison on Absolute Photoluminescence Quantum Yield Measurements of Solid Light Converting Phosphors with Three Commercial Integrating Sphere Setups
JF - American Chemical Society
N2 - Scattering luminescent materials dispersed in liquid and solid matrices and luminescent powders are increasingly relevant for fundamental research and industry. Examples are luminescent nano- and microparticles and phosphors of different compositions in various matrices or incorporated into ceramics with applications in energy conversion, solid-state lighting, medical diagnostics, and security barcoding. The key parameter to characterize the performance of these materials is the photoluminescence/fluorescence quantum yield (Φf), i.e., the number of emitted photons per number of absorbed photons. To identify and quantify the sources of uncertainty of absolute measurements of Φf of scattering samples, the first interlaboratory comparison (ILC) of three laboratories from academia and industry was performed by following identical measurement protocols. Thereby, two types ofcommercial stand-alone integrating sphere setups with different illumination and detection geometries were utilized for measuring the Φf of transparent and scattering dye solutions and solid phosphors, namely, YAG:Ce optoceramics of varying surface roughness, used as converter materials for blue light emitting diodes. Special emphasis was dedicated to the influence of the measurement geometry, the optical properties of the blank utilized to determine the number of photons of the incident excitation light absorbed by the sample, and the sample-specific surface roughness. While the Φf values of the liquid samples matched between instruments, Φf measurements of the optoceramics with different blanks revealed substantial differences. The ILC results underline the importance of the measurement geometry, sample position, and blank for reliable Φf data of scattering the YAG:Ce optoceramics, with the blank’s optical properties accounting for uncertainties exceeding 20%.
KW - Nano
KW - Fluorescence
KW - Reference material
KW - Luminescence
KW - Quantitative spectroscopy
KW - Particle
KW - Quantum yield
KW - Quality assurance
KW - Phosphor
KW - Converter material
KW - Lifetime
KW - Interlaboratory comparison
KW - Method
KW - Uncertainty
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-600945
DO - https://doi.org/10.1021/acs.analchem.4c00372
SN - 0003-2700
SP - 6730
EP - 6737
PB - ACS Publications
AN - OPUS4-60094
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Hartwig, Philipp
A1 - Bakir, Nasim
A1 - Gumenyuk, Andrey
A1 - Scheunemann, Lisa
A1 - Schröder, Jörg
A1 - Rethmeier, Michael
T1 - A Physically Motivated Heat Source Model for Laser Beam Welding
JF - Metals
N2 - In this contribution, we present a physically motivated heat source model for the numerical modeling of laser beam welding processes. Since the calibration of existing heat source models, such as the conic or Goldak model, is difficult, the representation of the heat source using so-called Lamé curves has been established, relying on prior Computational Fluid Dynamics (CFD) simulations.
Lamé curves, which describe the melting isotherm, are used in a subsequent finite-element (FE) simulation to define a moving Dirichlet boundary condition, which prescribes a constant temperature in the melt pool. As an alternative to this approach, we developed a physically motivated heat source model, which prescribes the heat input as a body load directly. The new model also relies on prior CFD simulations to identify the melting isotherm. We demonstrate numerical results of the new heat source model on boundary-value problems from the field of laser beam welding and compare it with the prior CFD simulation and the results of the Lamé curve model and experimental data.
KW - Welding simulation
KW - Heat source models
KW - Laser beam welding
KW - Thermal analysis
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-600899
DO - https://doi.org/10.3390/met14040430
VL - 14
IS - 4
SP - 1
EP - 26
PB - MDPI
CY - Basel
AN - OPUS4-60089
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Maulas, Kryzzyl M.
A1 - Paredes, Charla S.
A1 - Tabelin, Carlito Baltazar
A1 - Jose, Mark Anthony
A1 - Opiso, Einstine M.
A1 - Arima, Takahiko
A1 - Park, Ilhwan
A1 - Mufalo, Walubita
A1 - Ito, Mayumi
A1 - Igarashi, Toshifumi
A1 - Phengsaart, Theerayut
A1 - Villas, Edrhea
A1 - Dagondon, Sheila L.
A1 - Metillo, Ephrime B.
A1 - Uy, Mylene M.
A1 - Manua, Al James A.
A1 - Villacorte-Tabelin, Mylah
T1 - Isolation and Characterization of Indigenous Ureolytic Bacteria from Mindanao, Philippines: Prospects for Microbially Induced Carbonate Precipitation (MICP)
JF - Minerals
N2 - Microbially induced carbonate precipitation (MICP), a widespread phenomenon in nature, is gaining attention as a low-carbon alternative to ordinary Portland cement (OPC) in geotechnical engineering and the construction industry for sustainable development. In the Philippines, however, very few works have been conducted to isolate and identify indigenous, urease-producing (ureolytic) bacteria suitable for MICP. In this study, we isolated seven, ureolytic and potentially useful bacteria for MICP from marine sediments in Iligan City. DNA barcoding using 16s rDNA identified six of them as Pseudomonas stutzeri, Pseudomonas pseudoalcaligenes, Bacillus paralicheniformis, Bacillus altitudinis, Bacillus aryabhattai, and Stutzerimonas stutzeri but the seventh was not identified since it was a bacterial consortium. Bio-cementation assay experiments showed negligible precipitation in the control (without bacteria) at pH 7, 8, and 9. However, precipitates were formed in all seven bacterial isolates, especially between pH 7 and 8 (0.7–4 g). Among the six identified bacterial species, more extensive precipitation (2.3–4 g) and higher final pH were observed in S. stutzeri, and B. aryabhattai, which indicate better urease production and decomposition, higher CO2 generation, and more favorable CaCO3 formation. Characterization of the precipitates by scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM-EDS) and attenuated total reflectance Fourier transform spectroscopy (ATR-FTIR) confirmed the formation of three carbonate minerals: calcite, aragonite, and vaterite. Based on these results, all six identified indigenous, ureolytic bacterial species from Iligan City are suitable for MICP provided that the pH is controlled between 7 and 8. To the best of our knowledge, this is the first report of the urease-producing ability and potential for MICP of P. stutzeri, P. pseudoalcaligenes, S. stutzeri, and B. aryabhattai.
KW - Calcium carbonate
KW - Microbially induced carbonate precipitation (MICP)
KW - Ureolytic bacteria
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-600888
DO - https://doi.org/10.3390/min14040339
VL - 14
IS - 4
SP - 1
EP - 15
PB - MDPI
AN - OPUS4-60088
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Kingsbery, P.
A1 - Manzoni, Anna M.
A1 - Suarez Ocaño, Patricia
A1 - Többens, D. M.
A1 - Stephan‐Scherb, C.
T1 - High‐temperature KCl‐induced corrosion of high Cr and Ni alloys investigated by in‐situ diffraction
JF - Materials and Corrosion
N2 - High‐temperature KCl‐induced corrosion in laboratory air was observed in situ utilizing X‐ray diffraction. High Cr‐containing model alloys (Fe‐13Cr, Fe‐18Cr‐12Ni, and Fe‐25Cr‐20Ni) were coated with KCl and exposed to dry air at 560°C. KCl‐free alloys were studied in the equivalent atmosphere as a reference. After exposure to KCl‐free environments, all alloys showed the formation of very thin oxide layers, indicating good corrosion resistance. In contrast, KCl‐bearing alloys showed distinct damage after exposure.
KW - Corrosion
KW - In-situ diffraction
KW - High-temperature corrosion
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-600831
DO - https://doi.org/10.1002/maco.202314224
SN - 0947-5117
SP - 1
EP - 10
PB - Wiley VHC-Verlag
AN - OPUS4-60083
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Li, Z.
A1 - Raab, A.
A1 - Kolmangadi, Mohamed Aejaz
A1 - Busch, M.
A1 - Grunwald, M.
A1 - Demel, F.
A1 - Bertram, F.
A1 - Kityk, A. V.
A1 - Schönhals, Andreas
A1 - Laschat, S.
A1 - Huber, P.
T1 - Self-Assembly of Ionic Superdiscs in Nanopores
JF - ACS Nano
N2 - Discotic ionic liquid crystals (DILCs) consist of self-assembled superdiscs of cations and anions that spontaneously stack in linear columns with high one-dimensional ionic and electronic charge mobility, making them prominent model systems for functional soft matter. Compared to classical nonionic discotic liquid crystals, many liquid crystalline structures with a combination of electronic and ionic conductivity have been reported, which are of interest for separation membranes, artificial ion/proton conducting membranes, and optoelectronics. Unfortunately, a homogeneous alignment of the DILCs on the macroscale is often not achievable, which significantly limits the applicability of DILCs. Infiltration into nanoporous solid scaffolds can, in principle, overcome this drawback. However, due to the experimental challenges to scrutinize liquid crystalline order in extreme spatial confinement, little is known about the structures of DILCs in nanopores. Here, we present temperaturedependent high-resolution optical birefringence measurement and 3D reciprocal space mapping based on synchrotron X-ray scattering to investigate the thermotropic phase behavior of dopamine-based ionic liquid crystals confined in cylindrical channels of 180 nm diameter in macroscopic anodic aluminum oxide membranes. As a function of the membranes’ hydrophilicity and thus the molecular anchoring to the pore walls (edge-on or face-on) and the variation of the hydrophilic−hydrophobic balance between the aromatic cores and the alkyl side chain motifs of the superdiscs by tailored chemical synthesis, we find a particularly rich phase behavior, which is not present in the bulk state. It is governed by a complex interplay of liquid crystalline elastic energies (bending and splay deformations), polar interactions, and pure geometric confinement and includes textural transitions between radial and axial alignment of the columns with respect to the long nanochannel axis. Furthermore, confinement-induced continuous order formation is observed in contrast to discontinuous first-order phase transitions, which can be quantitatively described by Landau-de Gennes free energy models for liquid crystalline order transitions in confinement. Our observations suggest that the infiltration of DILCs into nanoporous solids allows tailoring their nanoscale texture and ion channel formation and thus their electrical and optical functionalities over an even wider range than in the bulk state in a homogeneous manner on the centimeter scale as controlled by the monolithic nanoporous scaffolds.
KW - Ionic Liquid Crystals
KW - Nanopropous materials
KW - Landau de-Gennes analysis
KW - X-ray scattering
KW - Optical birefringence
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-600797
DO - https://doi.org/10.1021/acsnano.4c01062
SN - 1936-0851
VL - 18
IS - 22
SP - 14414
EP - 14426
PB - ACS
AN - OPUS4-60079
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Silvestro, L.
A1 - Ruviaro, A. S.
A1 - Lima, G.
A1 - Durlo Tambara, Luis Urbano
A1 - Feys, D.
A1 - Kirchheim, A. P.
T1 - Rotational rheometry test of Portland cement-based materials - A systematic literature review
JF - Construction and Building Materials
N2 - This study systematically reviews 62 papers on the use of rotational rheometry to assess the fresh state behavior of Portland cement-based materials. The research highlights the wide variation in test methods and aims to provide a comprehensive overview. Findings reveal that 50.0% of studies employed vane geometry, despite its limitations in providing transformation equations. Regarding dynamic shearing tests, 67.0% followed a consensus using a pre-shearing step and a step-wise routine with stabilization times ≥ 10 s. While the Bingham model is commonly used, the study emphasizes the importance of considering shear-thinning behavior in cementitious materials. Models like Herschel-Bulkley and modified Bingham may be more appropriate. This review offers insights into testing conditions for rotational rheometry of cementitious materials, serving as a foundation for future research in the field.
KW - Review
KW - Rheology
KW - Rheometry
KW - Rotational
KW - Cement
PY - 2024
DO - https://doi.org/10.1016/j.conbuildmat.2024.136667
SN - 0950-0618
VL - 432
SP - 1
EP - 14
PB - Elsevier Ltd.
CY - Amsterdam
AN - OPUS4-60075
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Rhode, Michael
A1 - Mente, Tobias
A1 - Kannengiesser, Thomas
T1 - Parameters and challenges for reliable hydrogen determination in welded joints by carrier gas hot extraction
JF - The Paton Welding Journal
N2 - For the hydrogen-based energy economy of tomorrow, the construction of the necessary infrastructure will play a central role. Most materials used to date, such as welded steels, can be prone to hydrogen embrittlement under certain conditions. This includes the classic delayed cold cracking during welding as well as degradation phenomena during service of components in hydrogen-containing environment. For the evaluation of any hydrogen effect, for example, on the mechanical properties of a welded metallic material, the hydrogen content must be precisely determined. In the case of weld seams, the carrier gas hot extraction (CGHE) according to ISO 3690 is meanwhile state-of-the-art. CGHE is based on accelerated hydrogen degassing due to the thermal activation of hydrogen at elevated temperatures. In addition to the quantification of hydrogen, thermal desorption analysis (TDA) with varying heating rates can be used to determine and evaluate the hydrogen trapping at microstructural defects in the material. For both techniques, experimental and metrological influences must be considered, which have a major effect on the result. For example, ISO 3690 suggests different sample geometries and minimum extraction times for CGHE. This study summarizes the results and experiences of numerous investigations at the Federal Institute for Materials Research and Testing (BAM) with different sample temperatures and geometries (ISO 3690 type B and cylindrical TDA samples) regarding the influence of the sample surface (polished/welded), measurement accuracy depending on the sample volume and the insufficient monitoring of the effect of PI control on the extraction temperature. A deviating extraction temperature from the target temperature can significantly falsify the measurement results. Based on the results, methods are shown which allow the desired extraction temperature to be reached quickly without physically interfering with the measuring equipment. This serves to significantly improve the reliability of the hydrogen measurement through increased signal stability and accelerated hydrogen desorption. In general, an independent temperature measurement with dummy samples is recommended for the heating procedure of choice to exclude possible undesired temperature influences before the measurement. The methods described can be transferred directly to industrial applications
KW - Welding
KW - Hydrogen measurement
KW - ISO 3690
KW - Carrier gas hot extraction
PY - 2024
DO - https://doi.org/10.37434/tpwj2024.04.01
SN - 0957-798X
VL - 4
SP - 3
EP - 10
PB - International Association Welding
AN - OPUS4-60071
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - You, Yi
A1 - Danischewski, Julia
A1 - Molnar, Brian
A1 - Riedel, Jens
A1 - Shelley, Jacob
T1 - Manipulation of Gaseous Ions with Acoustic Fields at Atmospheric Pressure
JF - Journal of the American Chemical Society
N2 - The ability to controllably move gaseous ions is an essential aspect of ion-based spectrometry (e.g., mass spectrometry and ion mobility spectrometry) as well as materials processing. At higher pressures, ion motion is largely governed by diffusion and multiple collisions with neutral gas molecules. Thus, high-pressure ion optics based on electrostatics require large fields, radio frequency drives, complicated geometries, and/or partially transmissive grids that become contaminated. Here, we demonstrate that low-power standing acoustic waves can be used to guide, block, focus, and separate beams of ions akin to electrostatic ion optics. Ions preferentially travel through the static-pressure regions (“nodes”) while neutral gas does not appear to be impacted by the acoustic field structure and continues along a straight trajectory. This acoustic ion manipulation (AIM) approach has broad implications for ion manipulation techniques at high pressure, while expanding our fundamental understanding of the behavior of ions in gases.
KW - Ion mobility spectrometry
KW - Acoustic
KW - Mass spectrometry
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-600704
DO - https://doi.org/10.1021/jacs.4c01224
SP - 1
EP - 6
PB - ACS Publications
AN - OPUS4-60070
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Fareed, Adnan
A1 - Rosalie, Julian M.
A1 - Kar, Satyakam
A1 - Fähler, Sebastian
A1 - Maaß, Robert
T1 - Small-scale functional fatigue of a Ni-Mn-Ga Heusler alloy
JF - Acta Materialia
N2 - Functional fatigue of shape-memory alloys is a considerable threat to the reliable service of actuation devices. Here, we demonstrate the essentially degradation-free cyclic phase-transformation behavior of Ni-Mn-Ga microcrystals up to one million stress-driven superelastic cycles. Cyclic dissipation amounts to about 1/5 of the bulk counterpart and remains unaffected during cycling, even after the introduction of dislocation structures via plastic straining. Plastic yielding and the transformation stress largely exceed the known bulk values. However, the transformation-stress is found to depend on plastic pre-straining, which suggests that the size-affected transformation stress is sensitive to the initial defect structure and that it can be tuned by a targeted introduction of dislocations. These findings demonstrate the high suitability of Ni-Mn-Ga as a robust shape-memory alloy in small-scale functional device engineering.
KW - Superelasticity
KW - Shape-memory alloys
KW - Functional fatigue
KW - Ni-Mn-Ga
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-600695
DO - https://doi.org/10.1016/j.actamat.2024.119988
VL - 274
SP - 1
EP - 10
PB - Elsevier B.V.
AN - OPUS4-60069
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Neumann, Christian
A1 - Thore, Johannes
A1 - Clozel, Mélanie
A1 - Günster, Jens
A1 - Wilbig, Janka
A1 - Meyer, Andreas
T1 - Additive manufacturing of metallic glass from powder in space
JF - npj Microgravity
N2 - Additive manufacturing of metals – and in particular building with laser-based powder bed fusion – is highly flexible and allows high-resolution features and feedstock savings. Meanwhile, though space stations in low Earth orbit are established, a set of visits to the Moon have been performed, and humankind can send out rovers to explore Venus and Mars, none of these milestone missions is equipped with technology to manufacture functional metallic parts or tools in space. In order to advance space exploration to long-term missions beyond low Earth orbit, it will be crucial to develop and employ technology for in-space manufacturing (ISM) and in-situ resource utilisation (ISRU). To use the advantages of laser-based powder bed fusion in these endeavours, the challenge of powder handling in microgravity must be met. Here we present a device capable of building parts using metallic powders in microgravity. This was proven on several sounding rocket flights, on which occasions Zr-based metallic glass parts produced by additive manufacturing in space were built. The findings of this work demonstrate that building parts using powder feedstock, which is more compact to transport into space than wire, is possible in microgravity environments. This thus significantly advances ISRU and ISM and paves the way for future tests in prolonged microgravity settings.
KW - Metallic Glass
KW - Additive Manufacturing
KW - Space
PY - 2023
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-600667
DO - https://doi.org/10.1038/s41526-023-00327-7
VL - 9
SP - 1
EP - 9
PB - Springer Nature
AN - OPUS4-60066
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Goller, Sebastian M.
A1 - Schartel, Bernhard
A1 - Krüger, Simone
T1 - Phosphorus features halogen –calcium hypophosphite replaces antimony trioxide, reduces smoke, and improves flame retardancy
JF - Thermochimica Acta
N2 - Replacing antimony trioxide (ATO) in flame retardant formulations is an urgent task due to its toxicity. There are indications that calcium hypophosphite (CaP) may be a promising replacement. This study investigates the decomposition, fire behavior, and smoke release of brominated flame-retarded acrylonitrile butadiene styrene (ABS) under various fire scenarios like ignition, developing fire and smoldering, while replacing ATO with CaP and CaP/talc. Adding 4 wt.-% of talc to CaP formulations showed beneficial effects on flammability due to changes in the viscosity and barrier properties. Synergism between 8 wt.-% talc and CaP improved the protective layer in the developing fire scenario, resulting in a ∼60 % decrease in the peak of heat release rate and reduction of ∼21 % in total smoke production (ref. ABS+Br+ATO). With a conventional index of toxicity (CIT) of below 0.75, ABS+Br+CaP passes the highest requirements according to EN 45545-2. Overall, the CaP/talc materials improve flame retardancy, show less smoke emission under forced flaming conditions, and prevent chronic intoxication and environmental pollution through smoke particles contaminated with antimony.
KW - Smoke
KW - Flame retardancy
KW - Acrylonitrile butadiene styrene
KW - Calcium hypophosphite
KW - Antimony trioxide
PY - 2024
DO - https://doi.org/10.1016/j.tca.2024.179764
SN - 0040-6031
VL - 737
SP - 1
EP - 9
PB - Elsevier Ltd.
AN - OPUS4-60063
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Silbernagl, Dorothee
A1 - Szymoniak, Paulina
A1 - Tavasolyzadeh, Zeynab
A1 - Sturm, Heinz
A1 - Topolniak, Ievgeniia
T1 - Multiphoton Lithography of Interpenetrating Polymer Networks for Tailored Microstructure Thermal and Micromechanical Properties
JF - Small
N2 - Multiphoton lithography (MPL), an emerging truly 3D microfabrication technique, exhibits substantial potential in biomedical applications, including drug delivery and tissue engineering. Fabricated micro-objects are often expected to undergo shape morphing or bending of the entire structure or its parts. Furthermore, ensuring precise property tuning is detrimental to the realization of the functionality of MPL microstructures. Herein, novel MPL materials based on interpenetrating polymer networks (IPNs) are presented that effectively combine the advantages of acrylate and epoxy systems. IPNs with varying component ratios are investigated for their microfabrication performance and structural integrity with respect to thermal and micromechanical properties. A variety of high-resolution techniques is applied to comprehensively evaluate IPN properties at the bulk, micron, and segmental levels. This study shows that the MPL laser scanning velocity and power, photoinitiator content, and multi-step exposure can be used to tune the morphology and properties of the IPN. As a result, a library of 3D MPL IPN microstructures with high 3D structural stability and tailored thermal and micromechanical properties is achieved. New IPN microstructures with Young’s moduli of 3–4 MPa demonstrate high-to-fully elastic responses to deformations, making them promising for applications in morphable microsystems, soft micro-robotics, and cell engineering.
KW - Interpenetrating polymer network
KW - Multiphoton lithography
KW - Atomic force microscopy
KW - Intermodulation AFM
KW - Fast scanning calorimetry
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-600593
DO - https://doi.org/10.1002/smll.202310580
SN - 1613-6810
SP - 1
EP - 12
PB - Wiley VHC-Verlag
AN - OPUS4-60059
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Elert, Anna Maria
A1 - Chen, Yong-Cin
A1 - Smales, Glen J.
A1 - Topolniak, Ievgeniia
A1 - Sturm, Heinz
A1 - Schönhals, Andreas
A1 - Szymoniak, Paulina
T1 - Effects of the charge density of nanopapers based on carboxymethylated cellulose nanofibrils investigated by complementary techniques
JF - ACS Omega
N2 - Cellulose nanofibrils (CNFs) with different charge densities were prepared and investigated by a combination of different complementary techniques sensitive to the structure and molecular dynamics of the system. The morphology of the materials was investigated by scanning electron microscopy (SEM) and X-ray scattering (SAXS/WAXS). The latter measurements were quantitatively analyzed yielding to molecular parameters in dependence of the charge density like the diameter of the fibrils, the distance between the fibrils, and the dimension of bundles of nanofibrils, including pores. The influence of water on the properties and the charge density is studied by thermogravimetric analysis (TGA), differential scanning calorimetry (DSC) and broadband dielectric spectroscopy. The TGA measurements reveal two mass loss processes. The one at lower temperatures was related to the loss of water, and the second process at higher temperatures was related to the chemical decomposition. The resulting char yield could be correlated to the distance between the microfibrils. The DSC investigation for hydrated CNFs revealed three glass transitions due to the cellulose segments surrounded by water molecules in different states. In the second heating scan, only one broad glass transition is observed. The dielectric spectra reveal two relaxation processes. At low temperatures or higher frequencies, the β-relaxation is observed, which is assigned to localized fluctuation of the glycosidic linkage. At higher temperatures and lower frequencies, the α-relaxation takes places. This relaxation is due to cooperative fluctuations in the cellulose segments. Both processes were quantitatively analyzed. The obtained parameters such as the relaxation rates were related to both the morphological data, the charge density, and the content of water for the first time.
KW - Cellulose nanofibrils
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-600528
DO - https://doi.org/https://doi.org/10.1021/acsomega.4c00255
SN - 2470-1343
VL - 9
SP - 20152
EP - 20166
PB - ACS
AN - OPUS4-60052
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Hoffmann, Moritz
A1 - Stawarczyk, Bogna
A1 - Günster, Jens
A1 - Zocca, Andrea
T1 - Influence of additives and binder on the physical properties of dental silicate glass-ceramic feedstock for additive manufacturing
JF - Journal of the Mechanical Behavior of Biomedical Materials
N2 - Objectives
The aim of the study was to investigate the impact of organic additives (binder, plasticizer, and the cross-linking ink) in the formulation of water-based feedstocks on the properties of a dental feldspathic glass-ceramic material developed for the slurry-based additive manufacturing technology “LSD-print.”
Material and methods
Three water-based feldspathic feedstocks were produced to study the effects of polyvinyl alcohol (AC1) and poly (sodium 4-styrenesulfonate) (AC2) as binder systems. A feedstock without organic additives was tested as the control group (CG). Disc-shaped (n = 15) and bar (n = 7) specimens were slip-cast and characterized in the green and fired states. In the green state, density and flexural strength were measured. In the fired state, density, shrinkage, flexural strength (FS), Weibull modulus, fracture toughness (KIC), Martens parameters, and microstructure were analyzed. Disc-shaped and bar specimens were also cut from commercially available CAD/CAM blocks and used as a target reference (TR) for the fired state.
Results
In the green state, CG showed the highest bulk density but the lowest FS, while the highest FS in the green state was achieved with the addition of a cross-linking ink. After firing, no significant differences in density and a similar microstructure were observed for all slip-cast groups, indicating that almost complete densification could be achieved. The CAD/CAM specimens showed the highest mean FS, Weibull modulus, and KIC, with significant differences between some of the slip-cast groups.
Significance
These results suggest that the investigated feedstocks are promising candidates for the slurry-based additive manufacturing of restorations meeting the class 1a requirements according to DIN EN ISO 6871:2019–01.
KW - Firing
KW - 3D-printing
KW - Silicate glass-ceramics
KW - Debinding
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-600516
DO - https://doi.org/10.1016/j.jmbbm.2024.106563
SN - 1751-6161
VL - 155
SP - 1
EP - 12
PB - Elsevier B.V.
AN - OPUS4-60051
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Schröpfer, Dirk
A1 - Witte, Julien
A1 - Kromm, Arne
A1 - Kannengießer, Thomas
T1 - Stresses in repair welding of high-strength steels—part 2: heat control and stress optimization
JF - Welding in the World
N2 - In welding of high-strength steels, e.g. for foundations and erection structures of wind energy plants, unacceptable defects can occasionally be found in the weld area, which should be removed by thermal gouging and subsequent re-welding. High shrinkage restraint of repair welds may lead to crack formation and component failure, predominantly in interaction with degraded microstructures and mechanical properties due to repair cycles. This study aims for elaboration of recommendations for repair concepts appropriate to the stresses and materials involved to avoid cold cracking, damage and expensive reworking. In part 1 [1] of this study, systematic investigations of influences of shrinkage restraint on residual stresses and cold cracking risk during repair welding of two high-strength steels S500MLO for offshore application and S960QL for mobile crane structures were focussed. In this part 2, the microstructure, particularly hardness, and residual stresses due to gouging and influences of heat control parameters in repair welding are analysed. A clear reduction in residual stress after gouging can be observed, especially for the specimens with restrained transverse shrinkage. Gouging to a depth of approx. 2/3 of the seam height does not lead to a complete relaxation of the observed reaction forces. Particularly for the higher strength steel S960QL, there are pronounced areas influenced by the gouging process in which a degradation of the microstructure and properties should be assumed. Overall, the repair welds show a significant increase in the width of the weld and HAZ compared to the original weld, especially in the case of S960QL/G89. The repair welds show higher welding-induced stresses than the original welds, especially in the areas of the HAZ and the base metal close to the weld seam. This behaviour can be attributed overall to increased restraint conditions due to the remaining root weld or shorter gouge grooves. In good agreement with earlier investigations, the residual stresses transverse to the weld can be significantly reduced by upwardly limited working or interpass temperatures, and the reaction stresses resulting from high restraint conditions can be effectively counteracted. The influence of the heat input on the stress formation is low compared to the interpass temperature for both test materials.
KW - Repair-welding
KW - Wind Energy
KW - High-strength steels
KW - Cold cracking
KW - Residual stresses
KW - Offshore steels
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-600259
DO - https://doi.org/10.1007/s40194-024-01731-7
SN - 0043-2288
SP - 1
EP - 15
PB - Springer Nature
AN - OPUS4-60025
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Feng, Wen
A1 - Gemming, Thomas
A1 - Giebeler, Lars
A1 - Qu, Jiang
A1 - Weinel, Kristina
A1 - Agudo Jácome, Leonardo
A1 - Büchner, Bernd
A1 - González-Martínez, Ignacio
T1 - Influence of magnetic field on electron beam-induced Coulomb explosion of gold microparticles in transmission electron microscopy
JF - Ultramicroscopy
N2 - In this work we instigated the fragmentation of Au microparticles supported on a thin amorphous carbon film by irradiating them with a gradually convergent electron beam inside the Transmission Electron Microscope. This phenomenon has been generically labeled as “electron beam-induced fragmentation” or EBIF and its physical origin remains contested. On the one hand, EBIF has been primarily characterized as a consequence of beam-induced heating. On the other, EBIF has been attributed to beam-induced charging eventually leading to Coulomb explosion. To test the feasibility of the charging framework for EBIF, we instigated the fragmentation of Au particles under two different experimental conditions. First, with the magnetic objective lens of the microscope operating at full capacity, i.e. background magnetic field B = 2 T, and with the magnetic objective lens switched off (Lorenz mode), i.e. B = 0 T. We observe that the presence or absence of the magnetic field noticeably affects the critical current density at which EBIF occurs. This strongly suggests that magnetic field effects play a crucial role in instigating EBIF on the microparticles. The dependence of the value of the critical current density on the absence or presence of an ambient magnetic field cannot be accounted for by the beam-induced heating model. Consequently, this work presents robust experimental evidence suggesting that Coulomb explosion driven by electrostatic charging is the root cause of EBIF.
KW - Electron beam-induced fragmentation
KW - Coulomb explosion
KW - X-ray diffraction
KW - Lorenz transmission electron microscopy
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-600247
DO - https://doi.org/10.1016/j.ultramic.2024.113978
SN - 0304-3991
VL - 262
SP - 1
EP - 8
PB - Elsevier B.V.
CY - Amsterdam
AN - OPUS4-60024
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Feng, W.
A1 - Gemming, T.
A1 - Giebeler, L.
A1 - Qu, J.
A1 - Weinel, Kristina
A1 - Agudo Jácome, Leonardo
A1 - Büchner, B.
A1 - Gonzalez-Martinez, I.
T1 - Influence of magnetic field on electron beam-induced Coulomb explosion of gold microparticles in transmission electron microscopy
JF - Ultramicroscopy
N2 - In this work we instigated the fragmentation of Au microparticles supported on a thin amorphous carbon film by irradiating them with a gradually convergent electron beam inside the Transmission Electron Microscope. This phenomenon has been generically labeled as ‘‘electron beam-induced fragmentation’’ or EBIF and its physical origin remains contested. On the one hand, EBIF has been primarily characterized as a consequence of beam-induced heating. On the other, EBIF has been attributed to beam-induced charging eventually leading to Coulomb explosion. To test the feasibility of the charging framework for EBIF, we instigated the fragmentation of Au particles under two different experimental conditions. First, with the magnetic objective lens of the microscope operating at full capacity, i.e. background magnetic field 𝐵 = 2 T, and with the magnetic objective lens switched off (Lorenz mode), i.e. 𝐵 = 0 T. We observe that the presence or absence of the magnetic field noticeably affects the critical current density at which EBIF occurs. This strongly suggests that magnetic field effects play a crucial role in instigating EBIF on the microparticles. The dependence of the value of the critical current density on the absence or presence of an ambient magnetic field cannot be accounted for by the beam-induced heating model. Consequently, this work presents robust experimental evidence suggesting that Coulomb explosion driven by electrostatic charging is the root cause of EBIF.
KW - Electron beam-induced fragmentation
KW - Coulomb explosion
KW - X-ray diffraction
KW - Lorenz transmission electron microscopy
KW - Electron beam-induced charging
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-600170
DO - https://doi.org/10.1016/j.ultramic.2024.113978
VL - 262
SP - 1
EP - 8
PB - Elsevier B.V.
AN - OPUS4-60017
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Herter, Sven-Oliver
A1 - Koch, Matthias
A1 - Haase, Hajo
T1 - First Synthesis of Ergotamine-13CD3 and Ergotaminine-13CD3 from Unlabeled Ergotamine
JF - Toxins: Detection, Control and Contamination of Mycotoxins (Volume II)
N2 - Ergot alkaloids (EAs) formed by Claviceps fungi are one of the most common food contaminants worldwide, affecting cereals such as rye, wheat, and barley. To accurately determine the level of contamination and to monitor EAs maximum levels set by the European Union, the six most common EAs (so-called priority EAs) and their corresponding epimers are quantified using high-performance liquid chromatography coupled with tandem mass spectrometry (HPLC-MS/MS). The quantification of EAs in complex food matrices without appropriate internal tandards is challenging but currently carried out in the standard method EN 7425:2021 due to their commercial unavailability. To address the need for isotopically labeled EAs, we focus on two semi-synthetic approaches for the synthesis of these reference standards. Therefore, we investigate the feasibility of the N6-demethylation of native ergotamine to yield norergotamine, which can subsequently be remethylated with an isotopically labeled methylating reagent, such as iodomethane (13CD3-I), to yield isotopically labeled ergotamine and its C8-epimer ergotaminine. Testing the isotopically labeled ergotamine/-inine against native ergotamine/-inine with HPLC coupled to high-resolution HR-MS/MS proved the structure of ergotamine-13CD3 and ergotaminine-13CD3. Thus, for the first time, we can describe their synthesis from unlabeled, native ergotamine. Furthermore, this approach is promising as a universal way to synthesize other isotopically labeled EAs.
KW - Reference Material
KW - HPLC-MS/MS
KW - Mycotoxins
KW - Standards
KW - Organic Synthesis
KW - Isotope
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-600167
DO - https://doi.org/10.3390/toxins16040199
VL - 16
IS - 4
SP - 1
EP - 12
PB - MDPI
AN - OPUS4-60016
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Imbert, E.
A1 - Ladu, Luana
T1 - Editorial - Metrics for sustainable chemistry
JF - Current opinion in green and sustainable chemistry
N2 - This special issue addresses the current need to enhance the
conceptual and empirical implementation of sustainability assessment
methodologies and related metrics within the GSC (Green and Sustainable Chemistry), collecting 7 papers.
KW - Green and sustainable chemistry (GSC)
KW - Special issue
KW - Sustainability assessment methodologies
PY - 2023
DO - https://doi.org/10.1016/j.cogsc.2023.100844
SN - 2452-2236
VL - 43
SP - 1
EP - 3
PB - Elsevier
CY - Amsterdam
AN - OPUS4-59990
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Kricheldorf, H.
A1 - Weidner, Steffen
A1 - Scheliga, F.
T1 - Polycondensation of poly(L-lactide) alkyl esters combined with disproportionation and symproportionation of the chain lengths
JF - Journal of Polymer Science A: Polymer Chemistry
N2 - Ring-opening polymerizations (ROPs) of l-lactide (LA) were performed with ethyl l-lactate or 11-bromoundecanol as initiators (In) and tin(II) ethyl hexanoate (SnOct2) as catalyst (Cat) using four different LA/In ratios (20/1, 40/1, 60/1, and 100/1). One series of ROPs was conducted in bulk at 120 °C, yielding PLAs with low dispersities (Ð ~ 1.2–1.4), and a second series was conducted in bulk at 160 °C, yielding higher dispersities (Ð ~ 1.3–1.9). Samples from both series were annealed for 1 or 14 days at 140 °C in the presence of SnOct2. Both polycondensation and disproportionation reactions occurred, so that all four samples tended to form the same type of molar mass distribution below 10,000 Da, regardless of their initially different number average molar masses (Mn). Both initiators gave nearly identical results. The thermodynamic control of all reversible transesterification processes favored the formation of crystallites composed of chains with a Mn around 3500–3700, corresponding to a crystal thickness of 10–13 nm.
KW - Polylactide
KW - MALDI-TOF MS
KW - Crystalinity
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-600081
DO - https://doi.org/10.1002/pol.20240118
SN - 2642-4150
SP - 1
EP - 12
PB - Wiley
AN - OPUS4-60008
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Völker, Tobias
A1 - Gottlieb, Cassian
A1 - Kapteina, Gesa
A1 - Wilsch, Gerd
A1 - Millar, Steven
A1 - Reichling, Kenji
T1 - Neues DGZfP-Merkblatt B14: Quantifizierung von Chlorid in Beton mittels LIBS
JF - Beton- und Stahlbetonbau
N2 - Bei der Erhaltung von Stahlbetonbauwerken ist der Chloridgehalt im Beton ein wichtiger Parameter zur Festlegung geeigneter Instandsetzungsmaßnahmen. Die bisher etablierten Verfahren basieren auf der nasschemischen Analyse einer Probe, Bohrmehl oder aufgemahlener Segmente eines Bohrkerns. Das Verfahren liefert einen Chloridgehalt je Tiefensegment, was mit einer starken Homogenisierung der Probe einhergeht, wodurch detaillierte Informationen zu Chloridunterschieden im Millimeterbereich verloren gehen. Eine alternative Methode ist die laserinduzierte Plasmaspektroskopie (LIBS), die nicht nur die quantitative ortsaufgelöste Bestimmung des Chloridgehalts im Bezug zur Zementmasse ermöglicht, sondern auch simultan detaillierte Informationen über die Verteilung vieler anderer chemischer Elemente liefert. Die räumliche Auflösung liegt in der Regel im Bereich von einigen Millimetern, kann aber bei Bedarf auf 0,1 mm oder weniger erhöht werden. Das neue Merkblatt B14 „Quantifizierung von Chlorid in Beton mit der laserinduzierten Plasmaspektroskopie (LIBS)“ der Deutschen Gesellschaft für Zerstörungsfreie Prüfungen (DGZfP) regelt und vereinheitlicht erstmals die zuverlässige und reproduzierbare Ermittlung des Chloridgehalts mit LIBS. In diesem Beitrag wird das Merkblatt vorgestellt und anhand praktischer Anwendungsbeispiele das Potenzial von LIBS für Fragestellungen in der Betonerhaltung verdeutlicht.
KW - LIBS
KW - Chlor
KW - Chlorid
KW - Beton
KW - Bauwerksdiagnostik
PY - 2024
DO - https://doi.org/10.1002/best.202400014
SP - 1
EP - 7
AN - OPUS4-60005
LA - deu
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Neumann, Martin
A1 - Gröke, Carsten
A1 - Wille, Frank
T1 - BAM-GGR 016 - Auf dem aktuelle Stand
JF - Gefahrgut
N2 - Die BAM-GGR 016 zur Anerkennung und Überwachung von Managementsystemen für nicht zulassungspflichtige Verssandstücke für radioaktive Stoffe wurde kürzliche erstmals revidiert.
KW - BAM-GGR 016
KW - Überwachung
KW - Anerkennung
KW - Radioaktive Stoffe
PY - 2024
SN - 0944-6117
IS - 5
SP - 11
EP - 13
PB - Verlag Heinrich Vogel
CY - München
AN - OPUS4-59998
LA - deu
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Bäßler, Ralph
A1 - Amela Keserović, Amela
A1 - Sobetzki, Joana
A1 - Sarmiento Klapper, Helmuth
A1 - Dimper, Matthias
T1 - Geeignete Werkstoffe für Geothermieanwendungen (2)
JF - Galvanotechnik
N2 - Durch Auslagerungs- und elektrochemische Tests im Labor kann das Korrosionsverhalten verschiedener metallener Werkstoffe beurteilt werden. Aus den Versuchsergebnissen, die in verschiedenen synthetischen Geothermalwässern im Labor erzielt wurden, lassen sich die folgenden Schlussfolgerungen ziehen:
• Die Anfälligkeit für Spaltkorrosion wurde als wichtigster Aspekt für die Werkstoffqualifizierung ermittelt.
• Der niedriglegierte Stahl 25CrMo4 zeigte bei niedrigem Salzgehalt in MB-Geothermalwasser eine gleichmäßige Korrosion unterhalb der akzeptierten Schwelle von 0,3 mm/Jahr. Daher kann er als geeignet für geothermische Bedingungen mit niedrigem Salzgehalt angesehen werden, wie sie für MB getestet wurden. Es besteht keine Notwendigkeit, auf höherlegierte (teurere) Werkstoffe auszuweichen. Ein niedrigerer pH-Wert (wie bei LHD) führt zu Korrosionsraten oberhalb der akzeptablen Grenzwerte, so dass die niedriglegierten Werkstoffe nicht für Flüssigkeiten mit niedrigem pH-Wert geeignet sind.
• Stark salzhaltige Geothermalwässer erfordern höherlegierte Werkstoffe, da die Korrosionsrate von niedriglegiertem Stahl zu hoch ist.
• Der Duplexstahl X2CrNiMo22-5-3 und der Superduplexstahl X2CrNiMoCuWN25-7-4 wurden aufgrund ihrer kritischen Anfälligkeit für örtliche Korrosion in Form von Loch- und Spaltkorrosion unter Betriebsbedingungen nicht als geeignet für geothermische Anwendungen in Geothermalwässern mit einer mit NDB und ORG vergleichbaren Zusammensetzung angesehen.
• Der superaustenitische Stahl X1CrNiMoCu32-28-7 eignet sich für ORG und salzarme Wässer. In NDB-Geothermalwasser wurde er bei 100 °C als geeignet angesehen. Jedoch schränkt seine Anfälligkeit für Spaltkorrosion seine Anwendbarkeit ein. Neben seiner guten Korrosionsbeständigkeit ist sein Repassivierungsverhalten für seine begrenzte Anwendbarkeit in Geothermalwässern mit niedrigem pH-Wert verantwortlich.
• Die Nickelbasislegierung NiCr23Mo16Al wurde als geeignet erachtet und stellt eine sichere Option für den Einsatz in geothermischen Anlagen dar, selbst wenn mit stark salzhaltigem Geothermalwasser gearbeitet wird.
KW - Geothermie
KW - Korrosion
KW - Legierungen
KW - Anlagensicherheit
PY - 2024
SN - 0016-4232
VL - 2024
IS - 3
SP - 370
EP - 374
PB - Eugen G. Leuze Verlag
CY - Bad Saulgau
AN - OPUS4-59997
LA - deu
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Bäßler, Ralph
A1 - Amela Keserović, Amela
A1 - Sobetzki, Joana
A1 - Sarmiento Klapper, Helmuth
A1 - Dimper, Matthias
T1 - Geeignete Werkstoffe für Geothermieanwendungen (1)
JF - Galvanotechnik
N2 - Durch Auslagerungs- und elektrochemische Tests im Labor kann das Korrosionsverhalten verschiedener metallener Werkstoffe beurteilt werden. Aus den Versuchsergebnissen, die in verschiedenen synthetischen Geothermalwässern im Labor erzielt wurden, lassen sich die folgenden Schlussfolgerungen ziehen:
• Die Anfälligkeit für Spaltkorrosion wurde als wichtigster Aspekt für die Werkstoffqualifizierung ermittelt.
• Der niedriglegierte Stahl 25CrMo4 zeigte bei niedrigem Salzgehalt in MB-Geothermalwasser eine gleichmäßige Korrosion unterhalb der akzeptierten Schwelle von 0,3 mm/Jahr. Daher kann er als geeignet für geothermische Bedingungen mit niedrigem Salzgehalt angesehen werden, wie sie für MB getestet wurden. Es besteht keine Notwendigkeit, auf höherlegierte (teurere) Werkstoffe auszuweichen. Ein niedrigerer pH-Wert (wie bei LHD) führt zu Korrosionsraten oberhalb der akzeptablen Grenzwerte, so dass die niedriglegierten Werkstoffe nicht für Flüssigkeiten mit niedrigem pH-Wert geeignet sind.
• Stark salzhaltige Geothermalwässer erfordern höherlegierte Werkstoffe, da die Korrosionsrate von niedriglegiertem Stahl zu hoch ist.
• Der Duplexstahl X2CrNiMo22-5-3 und der Superduplexstahl X2CrNiMoCuWN25-7-4 wurden aufgrund ihrer kritischen Anfälligkeit für örtliche Korrosion in Form von Loch- und Spaltkorrosion unter Betriebsbedingungen nicht als geeignet für geothermische Anwendungen in Geothermalwässern mit einer mit NDB und ORG vergleichbaren Zusammensetzung angesehen.
• Der superaustenitische Stahl X1CrNiMoCu32-28-7 eignet sich für ORG und salzarme Wässer. In NDB-Geothermalwasser wurde er bei 100 °C als geeignet angesehen. Jedoch schränkt seine Anfälligkeit für Spaltkorrosion seine Anwendbarkeit ein. Neben seiner guten Korrosionsbeständigkeit ist sein Repassivierungsverhalten für seine begrenzte Anwendbarkeit in Geothermalwässern mit niedrigem pH-Wert verantwortlich.
• Die Nickelbasislegierung NiCr23Mo16Al wurde als geeignet erachtet und stellt eine sichere Option für den Einsatz in geothermischen Anlagen dar, selbst wenn mit stark salzhaltigem Geothermalwasser gearbeitet wird.
KW - Geothermie
KW - Korrosion
KW - Legierungen
KW - Anlagensicherheit
PY - 2024
SN - 0016-4232
VL - 2024
IS - 2
SP - 240
EP - 243
PB - Eugen G. Leuze Verlag
CY - Bad Saulgau
AN - OPUS4-59996
LA - deu
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Eberwein, Robert
A1 - Hajhariri, Aliasghar
A1 - Davide, Camplese
A1 - Giordano, Emrys Scarponi
A1 - Valerio, Cozzani
A1 - Frank, Otremba
T1 - Experimental investigation on the behavior of thermal super insulation materials for cryogenic storage tanks in fire incidents
JF - Process Safety and Environmental Protection
N2 - The number of vehicles using or transporting cryogenic fuels such as Liquefied Hydrogen (LH2) or Liquefied Natural Gas (LNG) increases fast in the land transportation sector. Does this also entail new risks? The storage of cryogenic fuels requires tanks with Thermal Super Insulations (TSI) to keep the fluid cold and limit the formation of boil-off gas. TSI has proven itself in some applications since the middle of the 20th century, but in the land transport sector they are still quite new, where accidents involving fires, collisions, and their combination are to be expected. This work focuses on investigating the behavior of different types of TSI while exposed to a heat source representing a fire. To this aim, a High-Temperature Thermal Vacuum Chamber (HTTVC) was applied, which allows the thermal loading of a thermal insulation material in a vacuum and measuring the heat flow transported through the TSI in parallel. In this study, the results of 6 samples are presented regarding 3 types of MLI, rock wool, perlites, and microspheres. The thermal exposure caused different effects on the samples. In practice, this can be connected to the rapid release of flammable gases as well as to a Boiling Liquid Expanding Vapour Explosion (BLEVE). These results are relevant for reducing the risks to people and infrastructures in the progressive establishment of tanks for cryogenic fluids in our industry and society. The data presented in the study can be used to improve the design of tanks and TSIs, the assessment of accident scenarios, and the development of measures for first responders.
KW - Liquefied hydrogen
KW - Liquefied natural gas
KW - Tanks
KW - Fire
KW - Insulation
KW - MLI
KW - Perlite
KW - Rock wool
KW - Microspheres
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-599947
DO - https://doi.org/10.1016/j.psep.2024.04.131
SN - 0957-5820
VL - 187
SP - 240
EP - 248
PB - Elsevier
AN - OPUS4-59994
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Henning, Ricky
A1 - Sturm, Patrick
A1 - Keßler, S.
A1 - Gluth, Gregor
ED - Lothenbach, B.
ED - Wieland, E.
ED - Altmaier, M.
T1 - Influence of salt aggregate on the degradation of hybrid alkaline cement (HAC) concretes in magnesium chloride-rich saline solution simulating evaporite rock
JF - Applied Geochemistry
N2 - Concretes produced from salt aggregate and hybrid alkaline cements, an alkali-activated slag/fly ash blend, or a Portland cement were exposed to a magnesium chloride-rich saline solution ([Mg2+] = 3.6 m, [Cl−] = 8.3 m), representing a solution formed after contact of surface water with evaporite rock (rock salt) in a nuclear waste repository. The hydration and deterioration of the concretes were studied with X-ray diffraction, thermogravimetric analysis, pH mapping and permeability measurements. The results show that calcium silicate hydrate (C-S-H) or sodium-substituted calcium aluminium silicate hydrate (C-N-A-S-H) and Friedel's salt were the major reaction products in the concretes prior to exposure to the saline solution. During exposure to the saline solution, increasing amounts of C-S-H/C-N-A-S-H dissolved, and gypsum and a secondary AFm phase formed. The durability of the concretes improved with increasing amounts of Portland clinker in the cements, due to the associated differences in permeability and chemical resistance. Nevertheless, a massive increase of permeability occurred for all concretes, likely caused by crack formation due to the formation of gypsum from anhydrite in the salt aggregate. Thus, the behavior of the concretes differed from, and was more complex than, the behavior of plain cement pastes.
T2 - Joint 6th International Workshop on Mechanisms and Modelling of Waste/Cement Interactions (JCCW 2023)
CY - Prague, Czech Republic
DA - 20.11.2023
KW - Nuclear waste repository
KW - Evaporite rock
KW - Magnesium chloride brine
KW - Concrete
KW - Hybrid alkaline cement
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-599928
DO - https://doi.org/10.1016/j.apgeochem.2024.106027
SN - 0883-2927
SN - 1872-9134
VL - 168
SP - 1
EP - 14
PB - Elsevier
AN - OPUS4-59992
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Gottinger, A.
A1 - Ladu, Luana
A1 - Blind, K.
T1 - Standardization in the context of science and regulation: An analysis of the Bioeconomy
JF - Environmental Science and Policy
N2 - Standards play a crucial role in the transition to more sustainable production and consumption models by promoting the development of new markets for innovative products. In the case of the bioeconomy, standards are particularly relevant to ensure the sustainability of products and processes. Hence, standards represent an essential strategic tool to foster sustainable development. Furthermore, the standard-setting process brings together different stakeholders, which encourages research and the transfer of knowledge to industrial practice. In particular, scientific publications assist the standardisation process by providing scientific evidence. This study investigates the role of science and regulation in the bioeconomy standardisation process. It first provides a general analysis of bioeconomy-related standards, followed by an analysis of the regulations and publications referenced in the standards. Our analysis discloses a strong use of scientific knowledge in the bioeconomy standardisation process and demonstrates the readiness to integrate novel academic findings into revised versions of the standards. In addition, it reveals that the interaction between science and regulation is an important driver for standardisation activities around the bioeconomy, needed to support sustainable transitions.
KW - Bioeconomy
KW - Standardisation
KW - Knowledge Use
KW - Socio-technical Transition
PY - 2023
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-599899
DO - https://doi.org/10.1016/j.envsci.2023.06.013
VL - 147
SP - 188
EP - 200
PB - Elsevier
AN - OPUS4-59989
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Vogel, Christian
A1 - Scholz, Philipp
A1 - Kalbe, Ute
A1 - Caliebe, W.
A1 - Tayal, A.
A1 - Vasala, S. J.
A1 - Simon, Franz-Georg
T1 - Speciation of antimony and vanadium in municipal solid waste incineration ashes analyzed by XANES spectroscopy
JF - Journal of Material Cycles and Waste Management
N2 - The use of ashes from municipal solid waste incineration as secondary building materials is an important pillar for the circular economy in Germany. However, leaching of potential toxic elements from these materials must be at environmentally acceptable levels. Normally, a three-month ageing period immobilizes most hazardous heavy metals, but antimony (Sb) and vanadium (V) showed previously unusual leaching. In order to clarify the mechanisms, we analyzed the Sb and V species in various bottom and fly ashes from municipal waste incineration by XANES spectroscopy. Antimony oxidizes from Sb(+ III) species used as flame retardants in plastics to Sb(+ V) compounds during waste incineration. However, owing to the similarity of different Sb(+ V) compound in the Sb K- and L-edge XANES spectra, it was not possible to accurately identify an exact Sb(+ V) species. Moreover, V is mainly present as oxidation state + V compound in the analyzed ashes. However, the coarse and magnetic fraction of the bottom ashes contain larger amounts of V(+ III) and V(+ IV) compounds which might enter the waste incineration from vanadium carbide containing steel tools. Thus, Sb and V could be critical potential toxic elements in secondary building materials and long-term monitoring of the release should be taken into account in the future.
KW - Müllverbrennung
KW - XANES spectroscopy
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-599841
DO - https://doi.org/10.1007/s10163-024-01954-2
SN - 1438-4957
SP - 1
EP - 7
PB - Springer Science and Business Media LLC
AN - OPUS4-59984
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Bayerlein, Bernd
A1 - Schilling, Markus
A1 - von Hartrott, Philipp
A1 - Waitelonis, Jörg
T1 - Semantic integration of diverse data in materials science: Assessing Orowan strengthening
JF - Scientific Data
N2 - AbstractThis study applies Semantic Web technologies to advance Materials Science and Engineering (MSE) through the integration of diverse datasets. Focusing on a 2000 series age-hardenable aluminum alloy, we correlate mechanical and microstructural properties derived from tensile tests and dark-field transmission electron microscopy across varied aging times. An expandable knowledge graph, constructed using the Tensile Test and Precipitate Geometry Ontologies aligned with the PMD Core Ontology, facilitates this integration. This approach adheres to FAIR principles and enables sophisticated analysis via SPARQL queries, revealing correlations consistent with the Orowan mechanism. The study highlights the potential of semantic data integration in MSE, offering a new approach for data-centric research and enhanced analytical capabilities.
KW - Semantic Interoperability
KW - Knowledge Graph
KW - Orowan Mechanism
KW - Aluminum Alloy Aging
KW - Ontology
KW - Semantic Data Integration
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-599780
DO - https://doi.org/10.1038/s41597-024-03169-4
VL - 11
IS - 1
SP - 1
EP - 12
PB - Springer Science and Business Media LLC
AN - OPUS4-59978
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Reveron, H.
A1 - Serrano-Munoz, Itziar
A1 - Kupsch, Andreas
A1 - Müller, B.R.
A1 - Chevalier, J.
A1 - Bruno, Giovanni
T1 - Transformation-induced plasticity in zirconia during tensile loading: A combined microscopy and synchrotron X-ray refraction study
JF - Materials Letters
N2 - The stress-induced tetragonal to monoclinic (t-m) zirconia phase transformation can provide a certain degree of plasticity to Ceria-stabilized (Ce-TZP) zirconia-based composites. Characterizing and monitoring this phase transition on a millimeter-size range, within the bulk and in-situ remains a challenge. In this work, the mechanical behavior of Ce-TZP based composite was studied in tension, combining microscopy and synchrotron Xray refraction techniques. In contrast with microscopy methods, which only provide surface information, X-ray refraction radiography (SXRR) allowed the visualization of all the transformation bands, over the entire length and thickness of tested specimens, opening up new avenues for in-situ stress-induced t-m transformation studies.
KW - Zirconia
KW - Ceria
KW - Composite
KW - Phase transformation
KW - Plasticity
KW - Synchrotron X-ray refraction
PY - 2024
DO - https://doi.org/10.1016/j.matlet.2024.136445
SN - 0167-577X
SN - 1873-4979
VL - 366
SP - 1
EP - 4
PB - Elsevier Ltd.
CY - Amsterdam
AN - OPUS4-59977
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Scholz, Philipp
A1 - Falkenhagen, Jana
A1 - Wachtendorf, Volker
A1 - Brüll, Robert
A1 - Simon, Franz-Georg
T1 - Investigation on the Durability of a Polypropylene Geotextile under Artificial Aging Scenarios
JF - Sustainability
N2 - Geosynthetics are widely used in various civil engineering applications, such as geotextiles in coastal protection, and display a sustainable alternative to natural mineral materials. However, the full benefits of using geosynthetics can only be gained with a long service lifetime of the products. With the use of added stabilizers to the polymers, service lifetimes can be achieved in the range of 100 years. Therefore, accelerated aging methods are needed for the assessment of the long-term performance of geotextiles. In the present study, the behavior of geosynthetic materials made of polypropylene was investigated under artificial aging conditions involving elevated temperatures ranging from 30 to 80 °C, increased oxygen pressures ranging from 10 to 50 bar in water-filled autoclaves, and UV irradiation under atmospheric conditions. ATR-IR spectroscopy was employed to detect the increase in the carbonyl index over various aging durations, indicating the oxidative degradation of the geotextile. The most pronounced increase was observed in the case of aging through UV irradiation, followed by thermal aging. Elevated pressure, on the other hand, had a lower impact on oxidation. High-temperature size exclusion chromatography was utilized to follow the reduction in molar mass under different degradation conditions, and the results were consistent with those obtained from ATR-IR spectroscopy. In polyolefins such as polypropylene, Hindered Amine Stabilizers (HAS) are used to suppress oxidation caused by UV radiation. The quantitative analysis of HAS was carried out using a UV/Vis method and HPLC. The degradation of UV stabilizers during the aging of geotextiles is responsible for the oxidation and the reduction in the molar mass of polypropylene. From the results, it can be concluded that applications of PP geotextile without soil or sand cover might cause the risk of the formation of microplastic particles. Material selection, design, and maintenance of the construction must follow best practices, including the system’s removal or replacement at end-of-life. Otherwise, a sustainable use of geotextiles in civil engineering is not possible.
KW - Geotextiles
KW - Microplastic
KW - Size exclusion chromatography
KW - Accelerated aging
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-599739
DO - https://doi.org/10.3390/su16093559
SN - 2071-1050
VL - 16
IS - 9
SP - 1
EP - 15
PB - MDPI AG
CY - Basel
AN - OPUS4-59973
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Barzegar, M.
A1 - Lugovtsova, Yevgeniya
A1 - Bulling, Jannis
A1 - Mishurova, Tatiana
A1 - Pasadas, Dario J.
A1 - Ribeiro, Artur L.
A1 - Ramos, Helena G.
T1 - Adhesive Porosity Analysis of Composite Adhesive Joints Using Ultrasonic Guided Waves
JF - IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control
N2 - Adhesively bonded composite joints can develop voids and porosity during fabrication, leading to stress concentration and a reduced load-carrying capacity. Hence, adhesive porosity analysis during the fabrication is crucial to ensure the required quality and reliability. Ultrasonic-guided wave (UGW)-based techniques without advanced signal processing often provide low-resolution imaging and can be ineffective for detecting small-size defects. This article proposes a damage imaging process for adhesive porosity analysis of bonded composite plates using UGWs measured by scanning laser Doppler vibrometer (LDV). To implement this approach, a piezoelectric transducer is mounted on the composite joint specimen to generate UGWs, which are measured over a densely sampled area. The signals obtained from the scan are processed using the proposed signal processing in different domains. Through the utilization of filter banks in frequency and wavenumber domains, along with the root-mean-square calculation of filtered signals, damage images of the adhesive region are obtained. It has been observed that different filters provide information related to different void sizes. Combining all the images reconstructed by filters, a final image is obtained which contains damages of various sizes. The images obtained by the proposed method are verified by radiography results and the porosity analysis is presented. The results indicate that the proposed methodology can detect the pores with the smallest detectable pore area of 2.41 mm^2, corresponding to a radius of 0.88 mm, with an overall tendency to overestimate the pore size by an average of 11%.
KW - Adhesives
KW - Damage imaging
KW - Nondestructive testing (NDT)
KW - Porosity analysis
KW - Signal processing
KW - Ultrasonic guided waves (UGWs)
PY - 2024
DO - https://doi.org/10.1109/TUFFC.2024.3371671
VL - 71
IS - 4
SP - 485
EP - 495
PB - Institute of Electrical and Electronics Engineers (IEEE)
AN - OPUS4-59970
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Adwani, D.
A1 - Pipintakos, G.
A1 - Mirwald, J.
A1 - Wang, Y.
A1 - Hajj, R.
A1 - Guo, M.
A1 - Liang, M.
A1 - Jing, R.
A1 - Varveri, A.
A1 - Zhang, Y.
A1 - Pei, K.
A1 - Xu, X.
A1 - Leng, Z.
A1 - Li, D.
A1 - Villamil, W.
A1 - Caro, S.
A1 - Chailleux, E.
A1 - Cantot, J.
A1 - Weigel, Sandra
A1 - Škulteckė, J.
A1 - Tarsi, G.
A1 - Margaritis, A.
A1 - Wang, H.
A1 - Hu, Y.
A1 - Airey, G.
A1 - Sreeram, A.
A1 - Bhasin, A.
T1 - Examining the efficacy of promising antioxidants to mitigate asphalt binder oxidation: Insights from a worldwide interlaboratory investigation
JF - International journal of pavement engineering
N2 - Oxidative aging induces significant stiffening of asphalt binders that leads to a pronounced reduction in the overall durability of asphalt pavements. The strategic implementation of antioxidant additives provides a potential solution to alleviate this issue. This work presents results from the second phase of the global consortium for antioxidants research aimed at investigating the effectiveness of potential antioxidants in increasing the durability of asphalt binders. Sixteen laboratories around the world participated in this effort and a total of 28 binders from diverse geographical regions were tested. Two promising antioxidants, namely zinc diethyldithiocarbamate (ZDC) and kraft lignin were evaluated in this phase and blended with the binders at specific proportions. Subsequently, a comprehensive investigation was conducted to assess rheological characteristics and chemical properties of the various blends, utilising Dynamic Shear Rheometer (DSR) measurements and Fourier Transform Infrared (FTIR) Spectroscopy. The findings indicate that additives such as ZDC hold considerable promise as an effective antioxidant, particularly when considering a wide diversity of binders. In general, its incorporation does not compromise the rutting performance of the binders and significantly improves fatigue performance. Therefore, research efforts should be focused on exploring additional facets to assess its practical applicability in field.
KW - Asphalt oxidation
KW - Binder aging
KW - Antioxidant additives
KW - Binder rheology
KW - Binder chemistry
KW - Bitumen und bitumenhaltige Bindemittel
KW - FTIR-Spektroskopie
KW - Anwendungsmöglichkeiten
KW - Vergleichsuntersuchung
KW - Arbeitsanleitung
KW - Präzision
PY - 2024
DO - https://doi.org/10.1080/10298436.2024.2332363
SN - 1477-268X
VL - 25
IS - 1
SP - 1
EP - 15
PB - Taylor & Francis
CY - London
AN - OPUS4-59957
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Isleyen, Alper
A1 - Can, Suleyman Z.
A1 - Cankur, Oktay
A1 - Tunc, Murat
A1 - Vogl, Jochen
A1 - Koenig, Maren
A1 - Horvat, Milena
A1 - Jacimovic, Radojko
A1 - Zuliani, Tea
A1 - Fajon, Vesna
A1 - Jotanovic, Aida
A1 - Gaževic, Luka
A1 - Milosevic, Milena
A1 - Ochsenkuehn–Petropoulou, Maria
A1 - Tsopelas, Fotis
A1 - Lymberopoulou, Theopisti
A1 - Tsakanika, Lamprini-Areti
A1 - Serifi, Olga
A1 - Ochsenkuehn, Klaus M.
A1 - Bulska, Ewa
A1 - Tomiak, Anna
A1 - Kurek, Eliza
A1 - Cakılbahçe, Zehra
A1 - Aktas, Gokhan
A1 - Altuntas, Hatice
A1 - Basaran, Elif
A1 - Kısacık, Barıs
A1 - Gumus, Zeynep
T1 - Certification of the total element mass fractions in UME EnvCRM 03 soil sample via a joint research project
JF - Accreditation and Quality Assurance
N2 - Soil certified reference material (CRM), UME EnvCRM 03 was produced by a collaborative approach among national metrology institutes, designated institutes and university research laboratories within the scope of the EMPIR project: Matrix Reference Materials for Environmental Analysis. This paper presents the sampling and processing methodology, homogeneity, stability, characterization campaign, the assignment of property values and their associated uncertainties in compliance with ISO 17034:2016. The material processing methodology involves blending a natural soil sample with a contaminated soil sample obtained by spiking elemental solutions for 8 elements (Cd, Co, Cu, Hg, Ni, Pb, Sb and Zn) to reach the level of warning risk monitoring values specified for metals and metalloids of soils in Europe. Comparative homogeneity and stability test data were obtained by two different institutes, ensuring the reliability and back up of the data. The certified values and associated expanded uncertainties for the total mass fractions of thirteen elements (As, Cd, Co, Cr, Cu, Fe, Hg, Mn, Ni, Pb, Sb, V and Zn) are established. The developed CRM can be used for the development and validation of measurement procedures for the determination of the total mass fractions of elements in soil and also for quality control/assurance purposes. The developed CRM is the first example of a soil material originating from Türkiye.
KW - Total element content
KW - Soil
KW - CRM
KW - Certification
KW - Environmental pollution monitoring
PY - 2024
DO - https://doi.org/10.1007/s00769-024-01597-8
SN - 1432-0517
SP - 1
EP - 9
PB - Springer Science and Business Media LLC
AN - OPUS4-59954
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Camplese, Davide
A1 - Scarponi, Giordano Emrys
A1 - Chianese, Carmela
A1 - Hajhariri, Aliasghar
A1 - Eberwein, Robert
A1 - Otremba, Frank
A1 - Cozzani, Valerio
T1 - Modeling the performance of multilayer insulation in cryogenic tanks undergoing external fire scenarios
JF - Process Safety and Environmental Protection
N2 - Multilayer Insulation (MLI) is frequently used in vacuum conditions for the thermal insulation of cryogenic storage tanks. The severe consequences of the degradation of such materials in engulfing fire scenarios were recently evidenced by several large-scale experimental tests. In the present study, an innovative modelling approach was developed to assess the performance of heat transfer in polyester-based MLI materials for cryogenic applications under fire conditions. A specific layer-by-layer approach was integrated with an apparent kinetic thermal degradation model based on thermogravimetric analysis results. The modeling results provided a realistic simulation of the experimental data obtained by High-Temperature Thermal Vacuum Chamber tests reproducing fire exposure conditions. The model was then applied to assess the behavior of MLI systems for liquid hydrogen tanks in realistic fire scenarios. The results show that in intense fire scenarios degradation occurs rapidly, compromising the thermal insulation performances of the system within a few minutes.
KW - Multilayer Insulation
KW - Cryogenic Vessels
KW - Liquefied Hydrogen
KW - Liquefied Natural Gas
KW - Safety
KW - Fire
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-599418
DO - https://doi.org/10.1016/j.psep.2024.04.061
SN - 0957-5820
VL - 186
SP - 1169
EP - 1182
PB - Elsevier B.V.
AN - OPUS4-59941
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Chen, Z.
A1 - Perez, J. P. H.
A1 - Smales, Glen Jacob
A1 - Blukis, R.
A1 - Pauw, Brian Richard
A1 - Stammeier, J. A.
A1 - Radnik, Jörg
A1 - Smith, A. J.
A1 - Benning, L. G.
T1 - Impact of organic phosphates on the structure and composition of short-range ordered iron nanophases
JF - Nanoscale advances
N2 - Organic phosphates (OP) are important nutrient components for living cells in natural environments, where they readily interact with ubiquitous iron phases such as hydrous ferric oxide, ferrihydrite (FHY). FHY partakes in many key bio(geo)chemical reactions including iron-mediated carbon storage in soils, or iron-storage in living organisms. However, it is still unknown how OP affects the formation, structure and properties of FHY. Here, we document how β-glycerophosphate (GP), a model OP ligand, affects the structure and properties of GP–FHY nanoparticles synthesized by coprecipitation at variable nominal molar P/Fe ratios (0.01 to 0.5). All GP–FHY precipitates were characterized by a maximum solid P/Fe ratio of 0.22, irrespective of the nominal P/Fe ratio. With increasing nominal P/Fe ratio, the specific surface area of the GP–FHY precipitates decreased sharply from 290 to 3 m2 g−1, accompanied by the collapse of their pore structure. The Fe–P local bonding environment gradually transitioned from a bidentate binuclear geometry at low P/Fe ratios to monodentate mononuclear geometry at high P/Fe ratios. This transition was accompanied by a decrease in coordination number of edge-sharing Fe polyhedra, and the loss of the corner-sharing Fe polyhedra. We show that Fe(III) polymerization is impeded by GP, and that the GP–FHY structure is highly dependent on the P/Fe ratio. We discuss the role that natural OP-bearing Fe(III) nanophases have in biogeochemical reactions between Fe–P and C species in aquatic systems.
KW - Organic phosphates
KW - Iron nanophases
KW - Scattering
KW - Diffraction
KW - Nanomaterials
KW - Coprecipitation
KW - Carbon storage
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-599399
DO - https://doi.org/10.1039/d3na01045g
SN - 2516-0230
SP - 1
EP - 13
PB - Royal Society of Chemistry (RSC)
CY - Cambridge
AN - OPUS4-59939
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Gluth, Gregor
A1 - Mundra, Shishir
A1 - Henning, Ricky
T1 - Chloride binding by layered double hydroxides (LDH/AFm phases) and alkali-activated slag pastes: an experimental study by RILEM TC 283-CAM
JF - Materials and Structures
N2 - Chloride binding by the hydrate phases of cementitious materials influences the rate of chloride ingress into these materials and, thus, the time at which chloride reaches the steel reinforcement in concrete structures. Chloride binding isotherms of individual hydrate phases would be required to model chloride ingress but are only scarcely available and partly conflicting. The present study by RILEM TC 283-CAM ‘Chloride transport in alkali-activated materials’ significantly extends the available database and resolves some of the apparent contradictions by determining the chloride binding isotherms of layered double hydroxides (LDH), including AFm phases (monosulfate, strätlingite, hydrotalcite, and meixnerite), and of alkali-activated slags (AAS) produced with four different activators (Na2SiO3, Na2O·1.87SiO2, Na2CO3, and Na2SO4), in NaOH/NaCl solutions at various liquid/solid ratios. Selected solids after chloride binding were analysed by X-ray diffraction, and thermodynamic modelling was applied to simulate the phase changes occurring during chloride binding by the AFm phases. The results of the present study show that the chloride binding isotherms of LDH/AFm phases depend strongly on the liquid/solid ratio during the experiments. This is attributed to kinetic restrictions, which are, however, currently poorly understood. Chloride binding by AAS pastes is only moderately influenced by the employed activator. A steep increase of the chloride binding by AAS occurs at free chloride concentrations above approx. 1.0 M, which is possibly related to chloride binding by the C–(N–)A–S–H gel in the AAS.
KW - Chloride binding
KW - Sorption isotherm
KW - Layered double hydroxide
KW - AFm phase
KW - Alkali-activated materials
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-599370
DO - https://doi.org/10.1617/s11527-024-02311-3
SN - 1359-5997
SN - 1871-6873
VL - 57
IS - 4
SP - 1
EP - 17
PB - Springer Nature
AN - OPUS4-59937
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Sonntag, Nadja
A1 - Piesker, Benjamin
A1 - Ávila Calderón, Luis Alexander
A1 - Mohr, Gunther
A1 - Rehmer, Birgit
A1 - Agudo Jácome, Leonardo
A1 - Hilgenberg, Kai
A1 - Evans, Alexander
A1 - Skrotzki, Birgit
T1 - Tensile and Low‐Cycle Fatigue Behavior of Laser Powder Bed Fused Inconel 718 at Room and High Temperature
JF - Advanced Engineering Materials
N2 - This study investigates the room‐ and high‐temperature (650 °C) tensile and low‐cycle‐fatigue behavior of Inconel 718 produced by laser powder bed fusion (PBF‐LB/M) with a four‐step heat treatment and compares the results to the conventional wrought material. The microstructure after heat treatment is characterized on different length scales. Compared to the wrought variant, the elastic and yield properties are comparable at both test temperatures while tensile strength, ductility, and strain hardening capacity are lower. The fatigue life of the PBF‐LB/M variant at room temperature is slightly lower than that of the wrought material, while at 650 °C, it is vice versa. The cyclic stress response for both material variants is characterized by cyclic softening, which is more pronounced at the higher test temperature. High strain amplitudes (≥0.7%) at room temperature and especially a high testing temperature result in the formation of multiple secondary cracks at the transitions of regions comprising predominantly elongated grain morphology and columns of stacked grains with ripple patterns in the PBF‐LB/M material. This observation and pronounced crack branching and deflection indicate that the cracks are controlled by sharp micromechanical gradients and local crystallite clusters.
KW - Additive manufacturing
KW - Fatigue damage
KW - Heat treatment
KW - Inconel 718
KW - Laser powder bed fusion
KW - Low-cycle fatigue
KW - Tensile strength
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-599316
DO - https://doi.org/10.1002/adem.202302122
SN - 1527-2648
SP - 1
EP - 17
PB - Wiley
AN - OPUS4-59931
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Temgoua, Ranil C.T.
A1 - Dontsi, Fabiola T.
A1 - Lebègue, Estelle
A1 - Thobie-Gautier, Christine
A1 - Tonlé, Ignas K.
A1 - Boujtita, Mohammed
T1 - Understanding the behavior of phenylurazole-tyrosine-click electrochemical reaction using hybrid electroanalytical techniques
JF - Journal of Pharmaceutical and Biomedical Analysis
N2 - In this work, the electrochemical behavior of 4-phenylurazole (Ph-Ur) was studied and the latter was used as a molecular anchor for the electrochemical bioconjugation of tyrosine (Y). Cyclic voltammetry (CV) and controlled potential coulometry (CPC) allowed the in-situ generation of the PTAD (4-phenyl-3 H-1,2,4-triazole-3,5(4 H)-dione) species from phenylurazole on demand for tyrosine electrolabeling. The chemoselectivity of the reaction was studied with another amino acid (lysine, Lys) and no changes in Lys were observed. To evaluate the performance of tyrosine electrolabeling, coulometric analyses at controlled potentials were performed on solutions of phenylurazole and the phenylurazole-tyrosine mixture in different proportions (2:1, 1:1, and 1:2). The electrolysis of the phenylurazole-tyrosine mixture in the ratio (1:2) produced a charge of 2.07 C, very close to the theoretical value (1.93 C), with high reaction kinetics, a result obtained here for the first time. The products obtained were identified and characterized by liquid chromatography coupled to high-resolution electrospray ionization mass spectrometry (LC-HRMS and LC- HRMS2). Two products were formed from the click reactions, one of which was the majority. Another part of this work was to study the electrochemical degradation of the molecular anchor 4-phenylazole (Ph-Ur). Four stable degradation products of phenylurazole were identified (C7H9N2O, C6H8N, C6H8NO, C14H13N4O2) based on chromatographic profiles and mass spectrometry results. The charge generated during the electrolysis of phenylurazole (two-electron process) (2.85 C) is inconsistent with the theoretical or calculated charge (1.93 C), indicating that secondary/parasitic reactions occurred during the electrolysis of the latter. In conclusion, the electrochemically promoted click phenylurazole-tyrosine reactions give rise to click products with high reaction kinetics and yields in the (1:2) phenylurazole-tyrosine ratios, and the presence of side reactions is likely to affect the yield of the click phenylurazole-tyrosine reaction.
KW - Clinical Biochemistry
KW - Spectroscopy
KW - Drug Discovery
KW - Pharmaceutical Science
KW - Analytical Chemistry
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-599267
DO - https://doi.org/10.1016/j.jpba.2024.116147
VL - 245
SP - 1
EP - 8
PB - Elsevier BV
AN - OPUS4-59926
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Leonhardt, Robert
A1 - Böttcher, Nils
A1 - Dayani, Shahab
A1 - Rieck, Arielle
A1 - Markötter, Henning
A1 - Schmidt, Anita
A1 - Kowal, Julia
A1 - Tichter, Tim
A1 - Krug von Nidda, Jonas
T1 - Exploring the electrochemical and physical stability of lithium-ion cells exposed to liquid nitrogen
JF - Journal of Energy Storage
N2 - The transport and storage of lithium-ion (Li-ion) batteries — damaged or in an undefined state — is a major safety concern for regulatory institutions, transportation companies, and manufacturers. Since (electro)chemical reactivity is exponentially temperature-dependent, cooling such batteries is an obvious measure for increasing their safety.
The present study explores the effect of cryogenic freezing on the electrochemical and physical stability of Li-ion cells. For this purpose, three different types of cells were repeatedly exposed to liquid nitrogen (LN2).
Before and after each cooling cycle, electrical and electrochemical measurements were conducted to assess the impact of the individual freezing steps. While the electrochemical behavior of the cells did not change significantly upon exposure to LN2 , it became apparent that a non-negligible number of cells suffered from physical changes (swelling) and functional failures. The latter defect was found to be caused by the current interrupt device of the cylindrical cells. This safety mechanism is triggered by the overpressure of expanding nitrogen which enters the cells at cryogenic temperatures.
This study underlines that the widely accepted reversibility of LN2 -cooling on a material scale does not allow for a direct extrapolation toward the physical integrity of full cells. Since nitrogen enters the cell at cryogenic temperatures and expands upon rethermalization, it can cause an internal overpressure. This can, in turn, lead to mechanical damage to the cell. Consequently, a more appropriate temperature condition — less extreme than direct LN2 exposure — needs to be found
KW - Lithium-ion battery
KW - LN2 cooling
KW - Battery characterization
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-599248
DO - https://doi.org/10.1016/j.est.2024.111650
VL - 89
SP - 1
EP - 7
PB - Elsevier B.V.
AN - OPUS4-59924
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Heyn, A.
A1 - Meist, M.
A1 - Michael, O.
A1 - Babutzka, M.
A1 - Valet, Svenja
A1 - Ebell, Gino
T1 - Electrochemical characterization of surfaces of galvanized steels under different exposure conditions using gel electrolytes
JF - Materials and Corrosion
N2 - The corrosion behavior of galvanized steels and zinc components under atmospheric exposure depends mostly on the corrosion product‐based cover layer formation under the prevailing conditions. The use of agar‐based gel electrolytes makes it possible to use electrochemical methods to obtain a characteristic value from these cover layers that describe their current and future protective capacity. It is shown here that different states of galvanized steel can be distinguished very well under laboratory conditions and that this method is also suitable for use under practical conditions. Based on the characteristic values and assuming future time of wetness, it is very easy to draw up a forecast for the future corrosion rate, which provides plausible values.
KW - Materials Chemistry
KW - Metals and Alloys
KW - Surfaces, Coatings and Films
KW - Mechanical Engineering
KW - Mechanics of Materials
KW - Environmental Chemistry
KW - Corrosion
KW - Znc
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-599234
DO - https://doi.org/10.1002/maco.202414389
SP - 1
EP - 16
PB - Wiley VHC-Verlag
AN - OPUS4-59923
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Lu, J.
A1 - Zhang, S.
A1 - Yao, J.
A1 - Guo, Z.
A1 - Osenberg, M.
A1 - Hilger, A.
A1 - Markötter, Henning
A1 - Wilde, F.
A1 - Manke, I.
A1 - Zhang, X.
A1 - Sun, F.
A1 - Cui, G.
T1 - Synergistic Effect of CO2 in Accelerating the Galvanic Corrosion of Lithium/Sodium Anodes in Alkali Metal−Carbon Dioxide Batteries
JF - ACS Nano
N2 - Rechargeable alkali metal−CO2 batteries, which combine high theoretical energy density and environmentally friendly CO2 fixation ability, have attracted worldwide attention. Unfortunately, their electrochemical performances are usually inferior for practical applications. Aiming to reveal the underlying causes, a combinatorial usage of advanced nondestructive and postmortem characterization tools is used to intensively study the failure mechanisms of Li/Na−CO2 batteries. It is found that a porous interphase layer is formed between the separator and the Li/Na anode during the overvoltage rising and battery performance decaying process. A series of control experiments are designed to identify the underlying mechanisms dictating the observed morphological evolution of Li/Na anodes, and it is found that the CO2 synergist facilitates Li/Na chemical corrosion, the process of which is further promoted by the unwanted galvanic corrosion and the electrochemical cycling conditions. A detailed compositional analysis reveals that the as-formed interphase layers under different conditions are similar in species, with the main differences being their inconsistent quantity. Theoretical calculation results not only suggest an inherent intermolecular affinity between the CO2 and the electrolyte solvent but also provide the most thermodynamically favored CO2 reaction pathways. Based on these results, important implications for the further development of rechargeable alkali metal−CO2 batteries are discussed. The current discoveries not only fundamentally enrich our knowledge of the failure mechanisms of rechargeable alkali metal−CO2 batteries but also provide mechanistic directions for protecting metal anodes to build high-reversible alkali metal−CO2 batteries.
KW - Alkali metal batteries
KW - Synchrotron X-ray computed tomography
KW - Lithium/sodium−carbon dioxide batteries
KW - Battery failure mechanisms
KW - Alkali metal anodes
PY - 2024
DO - https://doi.org/10.1021/acsnano.4c02329
SP - 1
EP - 16
AN - OPUS4-59922
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Tambara, R. F.
A1 - Durlo Tambara, Luis Urbano
A1 - Venquiaruto, S. D.
A1 - Pereira da Costa, F. B.
T1 - Evaluation of the mechanical performance and capillary absorption of concretes with incorporation of crystallizing admixtures and subjected to damage at early ages
T1 - Avaliação do desempenho mecânico e absorção capilar de concretos com incorporação de aditivos cristalizante submetidos a danos nas primeiras idades
JF - Matéria (Rio J.)
N2 - This study assessed the self-healing phenomenon in the mechanical properties and capillary absorption of structural concretes. Two crystalline powder additives were evaluated, dosed according to the manufacturers’ recommendations. Crystalline additives increase the density of the C-S-H gel and form insoluble crystals, effectively blocking fissures. Three concrete mixes were produced: a reference mix, additive-X with 0.8%, and additive-Y with 2.0%, relative to the mass of cement. 75% of the rupture load was applied at 3- and 14-days to induce microfissures for comparison with the reference mix. Subsequently, self-healing was assessed at 28- and 76-days. The property of axial compressive strength was determined at 28-days, revealing that crystalline additives contributed to an average increase of 12% in this property. While the age of loading did not significantly impact axial compressive strength, there were significant variations among the types of additives studied, as indicated by ANOVA. Water absorption properties through capillarity were evaluated at 28- and 76-days, showing an average reduction of 42% in water absorption due to the use of crystalline additives. In conclusion, the inclusion of crystalline additives positively contributed to the self-healing of the studied concretes, suggesting a partial recovery of microfissures.
N2 - Esta pesquisa avaliou o fenômeno de autocicatrização nas propriedades mecânicas e absorção capilar de concretos estruturais. Foram avaliados dois aditivos cristalizantes em pó, dosados de acordo com o teor recomendado pelos fabricantes. Aditivos cristalizantes aumentam a densidade do gel C-S-H e formam cristais insolúveis, bloqueando fissuras. Três traços de concreto foram produzidos: referência, aditivo-X com 0,8% e aditivo-Y com 2,0% em relação a massa do cimento. Aplicou-se 75% da carga de ruptura aos 3- e 14-dias para gerar microfissuras e comparar com a referência. Posteriormente, a autocicatrização foi avaliada aos 28- e 76-dias. A propriedade de resistência à compressão axial foi determinada aos 28-dias, revelando que os aditivos cristalizantes contribuíram para um aumento médio de 12% desta propriedade. A idade do carregamento dos concretos não apresentou um impacto significativo na resistência à compressão axial, mas apontou resultados significativos entre os tipos de aditivos estudados, conforme ANOVA. As propriedades de absorção de água por capilaridade foram avaliadas aos 28- e 76-dias, indicando uma redução de absorção de água média de 42% devido ao uso dos aditivos cristalizantes. Em conclusão, a incorporação dos aditivos cristalizantes contribuiu de maneira positiva para a autocicatrização dos concretos estudados, indicando uma recuperação parcial das microfissuras.
KW - Self-healing
KW - Crystalline admixture
KW - Concrete
KW - Cracks
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-599140
DO - https://doi.org/10.1590/1517-7076-RMAT-2023-0355
SN - 1517-7076
VL - 29
IS - 1
SP - 1
EP - 20
CY - Rio de Janeiro
AN - OPUS4-59914
LA - por
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Seifert, Lando
A1 - Grunewald, Andreas
A1 - Müller, Thoralf
A1 - Ebell, Gino
T1 - Stress corrosion tests for prestressing steels—Part 1: The influence of surface condition and test solution composition on hydrogen charging
JF - Materials and Corrosion
N2 - Tests for assessing prestressing steels' susceptibility to hydrogen‐induced stress corrosion cracking are essential for approvals, in‐house monitoring, and third‐party material testing. According to ISO 15630‐3, the time to brittle fracture by constant load under corrosive conditions in thiocyanate test solutions (A or B) at 50°C is measured. In the literature, a high scattering in stress corrosion tests is reported, which questions the integrity of the test procedure. This paper shows the results of studies about the influence of solution composition on hydrogen charging in electrochemical and permeation measurements. Electrochemical experiments show that polished steel surfaces without common drawing layers have more consistent free corrosion currents, polarization resistances, and B‐values in solution A with low scattering compared to the solution B experiments. The influence of temperature at 50°C and an ambient temperature of 22°C was also tested.
KW - Drawing layers
KW - Hydrogen‐induced stress corrosion cracking
KW - Permeation measurements
KW - Prestressing steels
KW - Stress corrosion tests
KW - Surface conditions
KW - Test solutions
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-598738
DO - https://doi.org/10.1002/maco.202313948
SP - 1
EP - 13
PB - Wiley‐VCH GmbH
AN - OPUS4-59873
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - You, Zengchao
A1 - Winckelmann, Alexander
A1 - Vogl, Jochen
A1 - Recknagel, Sebastian
A1 - Abad Andrade, Carlos Enrique
T1 - Determination of calcium, iron, and selenium in human serum by isotope dilution analysis using nitrogen microwave inductively coupled atmospheric pressure plasma mass spectrometry (MICAP-MS)
JF - Analytical and bioanalytical chemistry
N2 - In this study, we demonstrate the applicability of nitrogen microwave inductively coupled atmospheric pressure mass spectrometry (MICAP-MS) for Ca, Fe, and Se quantification in human serum using isotope dilution (ID) analysis. The matrix tolerance of MICAP-MS in Na matrix was investigated, uncovering that high Na levels can suppress the signal intensity. This suppression is likely due to the plasma loading and the space charge effect. Moreover, 40Ca and 44Ca isotopic fractionation was noted at elevated Na concentration. Nine certified serum samples were analyzed using both external calibration and ID analysis. Overestimation of Cr, Zn, As, and Se was found in the results of external calibration, which might be resulted from C-induced polyatomic interference and signal enhancement, respectively. Further investigations performed with methanol showed a similar enhancement effect for Zn, As, and Se, potentially supporting this assumption. The mass concentrations determined with ID analysis show metrological compatibility with the reference values, indicating that MICAP-MS combined with ID analysis can be a promising method for precise Ca, Fe, and Se determination. Moreover, this combination reduces the influences of matrix effects, broadening the applicability of MICAP-MS for samples with complex matrix.
KW - Selenium
KW - Nitrogen microwave inductively coupled atmospheric pressure mass spectrometry
KW - Isotope dilution
KW - Human serum
KW - Calcium
KW - Iron
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-598664
DO - https://doi.org/10.1007/s00216-024-05274-0
SN - 1618-2642
SP - 1
EP - 9
PB - Springer
CY - Berlin
AN - OPUS4-59866
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Völker, Tobias
A1 - Gornushkin, Igor B.
T1 - Mass and mole fractions in calibration-free LIBS
JF - Journal of Analytical Atomic Spectrometry
N2 - This technical note highlights the fact that CF-LIBS algorithms work in mole fractions, while results of spectrochemical analysis are usually reported in mass fractions or mass percent. Ignoring this difference and not converting mole fractions to mass fractions can lead to errors in reported concentrations determined by the CF-LIBS method and inadequate comparison of these concentrations with certified concentrations. Here, the key points of the CF-LIBS algorithm are reproduced and the formulae for converting a mole fraction to a mass fraction and vice versa are given. Several numerical examples are also given, which show that the greater the difference between the molar mass of an individual element in a sample and the average molar mass, the greater the discrepancy between the mole and mass fractions.
KW - Spectroscopy
KW - Analytical Chemistry
KW - LIBS
KW - Calibration
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-598611
DO - https://doi.org/10.1039/d4ja00028e
SN - 0267-9477
VL - 39
IS - 4
SP - 1030
EP - 1032
PB - Royal Society of Chemistry (RSC)
AN - OPUS4-59861
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -