TY - JOUR A1 - Portarapillo, Maria A1 - Di Benedetto, Almerinda A1 - Spitzer, Stefan T1 - Turbulence effect on the determination of powders safety characteristics — A review on the experimental findings and simulation approaches N2 - Safety characteristics are widely used in the process industry to design facilities in a safe way. For powders, they are normally investigated under turbulent conditions inside a spherical test vessel, the so called 20L-sphere, to disperse the dust in air. This has been the target of many researchers to either investigate the turbulence that is present during the standardized test conditions, to compare it to quiescent conditions or to manipulate it for the comparison to other conditions. The approaches have been numerous and while the focus used to be on obtaining different experimental results it has shifted more and more to different kinds of simulations. This review gives an overview about different simulation approaches and how they can be compared. It is also an overview over the experimental findings and compares it to data obtained for three different dusts while changing the pre-ignition turbulence level in a very fine way. KW - Explosion protection KW - Dusts KW - Pressure rise KW - Ignition PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-625216 DO - https://doi.org/10.1016/j.powtec.2025.120694 SN - 1873-328X VL - 454 SP - 1 EP - 19 PB - Elsevier B.V. AN - OPUS4-62521 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Guo, Y. A1 - Lippitz, Andreas A1 - Saftien, P. A1 - Unger, Wolfgang A1 - Kemnitz, E. T1 - Tuning the surface properties of novel ternary iron(III) fluoride-based catalysts using the template effect of the matrix N2 - Sol–gel prepared ternary FeF3–MgF2 materials have become promising heterogeneous catalysts due to their porosity and surface Lewis/Brønsted acidity (bi-acidity). Despite the good catalytic performance, nanoscopic characterisations of this type of material are still missing and the key factors controlling the surface properties have not yet been identified, impeding both a better understanding and further development of ternary fluoride catalysts. In this study, we characterised the interaction between the bi-acidic component (FeF3) and the matrix (MgF2) on the nano-scale. For the first time, the formation pathway of FeF3–MgF2 was profiled and the template effect of MgF2 during the synthesis process was discovered. Based on these new insights two novel materials, FeF3–CaF2 and FeF3–SrF2, were established, revealing that with decreasing the atomic numbers (from Sr to Mg), the ternary fluorides exhibited increasing surface acidity and surface area but decreasing pore size. These systematic changes gave rise to a panel of catalysts with tuneable surface and bulk properties either by changing the matrix alkaline earth metal fluoride or by adjusting their ratios to Fe or both. The template effect of the alkaline earth metal fluoride matrix was identified as the most probable key factor determining the surface properties and further influencing the catalytic performance in ternary fluoride based catalysts, and paves the way to targeted design of next-generation catalysts with tunable properties. KW - Catalysis KW - Surface analysis KW - XPS PY - 2015 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-327410 DO - https://doi.org/10.1039/c4dt03229b SN - 1477-9226 SN - 1477-9234 SN - 1364-5447 VL - 44 IS - 11 SP - 5076 EP - 5085 PB - RSC CY - Cambridge AN - OPUS4-32741 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Feiler, Torvid A1 - Bhattacharya, Biswajit A1 - Michalchuk, Adam A1 - Rhim, S.-Y. A1 - Schöder, V. A1 - List-Kratochvil, E. A1 - Emmerling, Franziska T1 - Tuning the mechanical flexibility of organic molecular crystals by polymorphism for flexible optical waveguides N2 - The ability to selectively tune the optical and the mechanical properties of organic molecular crystals offers a promising approach towards developing flexible optical devices. These functional properties are sensitive to crystallographic packing features and are hence expected to vary with polymorphic modification. Using as a model system the photoluminescent material 4-bromo-6-[(6-chloropyridin-2-ylimino)methyl]phenol (CPMBP), we herein demonstrate the simultaneous tuning of mechanical flexibility and photoluminescence properties via polymorphism. Two new polymorphic forms of CPMBP were obtained from a solution and fully characterised using a combination of experiments and density functional theory simulations. These polymorphic forms exhibit remarkably distinct mechanical properties and an order of magnitude difference in photoluminescence quantum yield. The mechanically plastic form has a higher quantum yield than the brittle polymorphic form. However, their photoluminescence emission profile is largely unaffected by the observed polymorphism, thereby demonstrating that the optical properties and bulk mechanical properties can in principle be tuned independently. By distinguishing between active (involving absorption and emission) and passive (involving no absorption) light propagation, the waveguiding properties of the plastic form of CPMBP (form II) were explored using the straight and bent crystals to highlight the potential applications of CPMBP in designing flexible optical devices. Our results demonstrated that polymorph engineering would be a promising avenue to achieve concurrent modulation of the optical and mechanical properties of photoluminescent molecular crystals for next-generation flexible optical device applications. KW - Mechanochemistry KW - Flexible PY - 2021 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-532075 DO - https://doi.org/10.1039/d1ce00642h VL - 23 IS - 34 SP - 5815 EP - 5825 PB - Royal Society of Chemistry CY - London AN - OPUS4-53207 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Taparli, Ugur Alp A1 - Kannengießer, Thomas A1 - Griesche, Axel T1 - Tungsten inert gas bead-on-plate weld chemical composition analysis by laser-induced breakdown spectroscopy N2 - Chemical compositions of a weld can be varying locally as a result of the welding process. These local variations can be due to the vaporization of individual alloying elements. In this work, tungsten inert gas (TIG) bead-on-plate stainless steel welds of EN grade 1.4404 and 1.4435 were investigated using laser-induced breakdown spectroscopy (LIBS) on the completed welds. This study aims to reveal the welding parameters’ influence on the resulting local chemical compositions of the stainless steel welds. We demonstrated Mn vaporize before Cr due to its lower latent enthalpy of vaporization. Hence, Mn accumulates on the heat-affected zone (HAZ) both sides across the weld bead by being swept away through the circulation flow of the welding plasma. Additionally, increasing the heat input tends to enhance the accumulated Mn content on the HAZ as well as increasing the shielding gas flow rate. The results are in good agreement with the literature and proved that LIBS is an effective method to inspect completed welds. T2 - Symposium on Materials and Joining Technology CY - Magdeburg, Germany DA - 07.09.2020 KW - LIBS TIG welding KW - Austenitic stainless steels KW - Chemical composition KW - In situ measurement PY - 2020 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-511595 DO - https://doi.org/10.1088/1757-899X/882/1/012023 SN - 1757-8981 SN - 1757-899X VL - 882 IS - 012023 SP - 1 EP - 8 PB - IOP Publishing CY - Bristol AN - OPUS4-51159 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Bhuckory, S. A1 - Wegner, Karl David A1 - Qiu, X. A1 - Wu, Y.T. A1 - Jennings, T. L. A1 - Incamps, A. A1 - Hildebrandt, N. T1 - Triplexed CEA-NSE-PSA Immunoassay Using Time-Gated Terbium-to-Quantum Dot FRET N2 - Time-gated Förster resonance energy transfer (TG-FRET) between Tb complexes and luminescent semiconductor quantum dots (QDs) provides highly advantageous photophysical properties for multiplexed biosensing. Multiplexed Tb-to-QD FRET immunoassays possess a large potential for in vitro diagnostics, but their performance is often insufficient for their application under clinical conditions. Here, we developed a homogeneous TG-FRET immunoassay for the quantification of carcinoembryonic antigen (CEA), neuron-specific enolase (NSE), and prostatespecific antigen (PSA) from a single serum sample by multiplexed Tb-to-QD FRET. Tb–IgG antibody donor conjugates were combined with compact QD-F(ab’)2 antibody acceptor conjugates with three different QDs emitting at 605, 650, and 705 nm. Upon antibody–antigen–antibody Sandwich complex formation, the QD acceptors were sensitized via FRET from Tb, and the FRET ratios of QD and Tb TG luminescence intensities increased specifically with increasing antigen concentrations. Although limits of detection (LoDs: 3.6 ng/mL CEA, 3.5 ng/mL NSE, and 0.3 ng/mL PSA) for the triplexed assay were slightly higher compared to the single-antigen assays, they were still in a clinically relevant concentration range and could be quantified in 50 μL serum samples on a B·R·A·H·M·S KRYPTOR Compact PLUS clinical immunoassay plate reader. The simultaneous quantification of CEA, NSE, and PSA at different concentrations from the same serum sample demonstrated actual multiplexing Tb-to-QD FRET immunoassays and the potential of this technology for translation into clinical diagnostics. KW - Lanthanides KW - Nanoparticles KW - Biosensing KW - Multiplexing KW - FRET KW - Fluorescence KW - PSA KW - NSE KW - CEA PY - 2020 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-512290 DO - https://doi.org/10.3390/molecules25163679 VL - 25 IS - 16 SP - 3679 PB - MDPI AN - OPUS4-51229 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Gharaati, S. A1 - Wang, Cui A1 - Förster, C. A1 - Weigert, Florian A1 - Resch-Genger, Ute A1 - Heinze, K. T1 - Triplet–Triplet Annihilation Upconversion in a MOF with AcceptorFilled Channels N2 - In summary, we report a highly modular solid TTA-UC system comprising of a crystalline, thermally stable PCN222(Pd) MOF with CA-coated MOF channels and with a DPA annihilator embedded in a solution-like environment in the MOF channels. This solid material displays blue upconverted delayed emission with a luminescence lifetime of 373 us, a threshold value of 329 mW*cm-2 and a triplet–triplet energy transfer efficiency of 82%. This optical application adds another facet to the versatile chemistry of PCN-222 MOFs. The design concept is also applicable to other TTA-UC pairs and enables tuning of the UCL color, for example, by replacing DPA with other dyes as exemplarily shown for 2,5,8,11-tetra-tert-butyl-perylene, that yields UCL at 450 nm. Current work aims to reduce the oxygen sensitivity and to increase the retention of the trapped annihilators in organic environments, for example, by tuning the chain length of the carboxylic acid and by coating the MOF surface. In addition, the TTA-UC efficiency will be further enhanced by reducing the reabsorption of the UC emission caused by Pd(TCPP) and by optimizing the sensitizer/annihilator interface. KW - Porphyrin KW - Method KW - MOF KW - Fluorescence KW - Dye KW - Sensor KW - Oxygen sensitive KW - Single molecule KW - DPA KW - Lifetime KW - Upconverstion KW - Quantum yield KW - Triplet-triplet annihilation KW - Sensitization KW - Energy transfer KW - NMR PY - 2019 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-500580 DO - https://doi.org/10.1002/chem.201904945 VL - 26 IS - 5 SP - 1003 EP - 1007 PB - Wiley-VCH Verlag CY - Weinheim AN - OPUS4-50058 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Wurster, S. A1 - Ladu, Luana T1 - Triple-C: A Tridimensional Sustainability-Oriented Indicator for Assessing Product Circularity in Public Procurement N2 - Various microlevel circular economy indicators for assessing sustainability and, partly, additional sustainability characteristics have been developed, but an integrated solution considering the environmental, social, and economic pillars remains a research gap. Method: Based on a multimethod approach, including surveys and the analysis of existing sustainability assessment methodologies and standards, this paper proposes a concept for a multidimensional circular economy indicator tailored to public procurers. It relies on attractive existing building blocks including: the ecological scarcity method, European and international sustainability standards and indicators,and the STAR-ProBio-IAT concept. Results: This article presents the concept of the composite indicator Triple-C, consisting of 20 elements and aimed at facilitating sustainable circular public procurement. It is intended to be incorporated into software that facilitates sustainable product decisions among public procurers in Germany. Conclusions: We propose a generic indicator concept covering all three (environmental, social, and economic) sustainability pillars. More research and additional standards are needed to develop the Triple-C concept further into product-specific applications. KW - Circular economy KW - Sustainability assessment KW - Circularity KW - Ecological scarcity method KW - Life-cycle assessment KW - LCA KW - Life-cycle costing KW - LCC KW - Social sustainability KW - Indicators PY - 2022 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-564115 DO - https://doi.org/10.3390/su142113936 VL - 14 IS - 21 SP - 1 EP - 23 PB - MDPI CY - Berlin AN - OPUS4-56411 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Scholtz, G. A1 - Staude, Andreas A1 - Dunlop, J.A. T1 - Trilobite compound eyes with crystalline cones and rhabdoms show mandibulate affinities N2 - Most knowledge about the structure, function, and evolution of early compound eyes is based on investigations in trilobites. However, these studies dealt mainly with the cuticular lenses and little was known about internal anatomy. Only recently some data on crystalline cones and retinula cells were reported for a Cambrian trilobite species. Here, we describe internal eye structures of two other trilobite genera. The Ordovician Asaphus sp. reveals preserved crystalline cones situated underneath the cuticular lenses. The same is true for the Devonian species Archegonus (Waribole) warsteinensis, which in addition shows the fine structure of the rhabdom in the retinula cells. These results suggest that an apposition eye with a crystalline cone is ancestral for Trilobita. The overall similarity of trilobite eyes to those of myriapods, crustaceans, and hexapods corroborates views of a phylogenetic position of trilobites in the stem lineage of Mandibulata. KW - Trilobite compound eyes KW - Computed Tomography PY - 2019 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-510784 DO - https://doi.org/10.1038/s41467-019-10459-8 SN - 2041-1723 VL - 10 SP - 2503 PB - Nature AN - OPUS4-51078 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Staude, Andreas A1 - Scholtz, G. A1 - Dunlop, J. A. T1 - Trilobite compound eyes with crystalline cones and rhabdoms show mandibulate affinities N2 - Most knowledge about the structure, function, and evolution of early compound eyes is based on investigations in trilobites. However, these studies dealt mainly with the cuticular lenses and little was known about internal anatomy. Only recently some data on crystalline cones and retinula cells were reported for a Cambrian trilobite species. Here, we describe internal eye structures of two other trilobite genera. The Ordovician Asaphus sp. reveals preserved crystalline cones situated underneath the cuticular lenses. The same is true for the Devonian species Archegonus (Waribole) warsteinensis, which in addition shows the fine structure of the rhabdom in the retinula cells. These results suggest that an apposition eye with a crystalline cone is ancestral for Trilobita. The overall similarity of trilobite eyes to those of myriapods, crustaceans, and hexapods corroborates views of a phylogenetic position of trilobites in the stem lineage of Mandibulata. KW - Coputed tomography KW - Crystalline cones PY - 2019 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-483889 DO - https://doi.org/10.1038/s41467-019-10459-8 SN - 2041-1723 VL - 10 SP - 2503, 1 EP - 7 PB - Nature AN - OPUS4-48388 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kirner, Sabrina V. A1 - Slachciak, Nadine A1 - Elert, Anna Maria A1 - Griepentrog, Michael A1 - Fischer, Daniel A1 - Hertwig, Andreas A1 - Sahre, Mario A1 - Dörfel, Ilona A1 - Sturm, Heinz A1 - Pentzien, Simone A1 - Koter, Robert A1 - Spaltmann, Dirk A1 - Krüger, Jörg A1 - Bonse, Jörn T1 - Tribological performance of titanium samples oxidized by fs-laser radiation, thermal heating, or electrochemical anodization N2 - Commercial grade-1 titanium samples (Ti, 99.6%) were treated using three alternative methods, (i) femtosecond laser processing, (ii) thermal heat treatment, and (iii) electrochemical anodization, respectively, resulting in the formation of differently conditioned superficial titanium oxide layers. The laser processing (i) was carried out by a Ti:sapphire laser (pulse duration 30 fs, central wavelength 790 nm, pulse repetition rate 1 kHz) in a regime of generating laser-induced periodic surface structures (LIPSS). The experimental conditions (laser fluence, spatial spot overlap) were optimized in a sample-scanning setup for the processing of several square-millimeters large surface areas covered homogeneously by these nanostructures. The differently oxidized titanium surfaces were characterized by optical microscopy, micro Raman spectroscopy, variable angle spectroscopic ellipsometry, and instrumented indentation testing. The tribological performance was characterized in the regime of mixed friction by reciprocating sliding tests against a sphere of hardened steel in fully formulated engine oil as lubricant. The specific tribological performance of the differently treated surfaces is discussed with respect to possible physical and chemical mechanisms. KW - Femtosecond laser KW - Titanium KW - Oxidation KW - Friction PY - 2018 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-445609 DO - https://doi.org/10.1007/s00339-018-1745-8 SN - 0947-8396 SN - 1432-0630 VL - 124 IS - 4 SP - 326, 1 EP - 10 PB - Springer-Verlag AN - OPUS4-44560 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Gradt, Thomas A1 - Schneider, Thomas T1 - Tribological performance of MoS2 coatings in various environments N2 - Molybdenum disulfide (MoS₂) is a well-known solid lubricant for tribosystems running in vacuum or dry gases. Problems arise due to its sensitivity to humidity, which is a drawback for its application under ambient conditions. However, by using a physical vapor deposition (PVD) process, deposition parameters can be optimized not only to gain a coatings structure with favorable frictional properties but also to minimize the sensitivity to attack by water molecules. Therefore, an improved tribological behavior even under moist conditions can be achieved. MoS₂coatings are also candidates for being applied at cryogenic temperatures. They already have proven their suitability, e.g., for sliding support elements between superconducting magnets of the nuclear fusion-experiment Wendelstein 7-X. However, these coatings were exclusively produced for this particular application and the utilization for more common tribosystems may be precluded due to cost considerations. In view of a wider range of applications, pure and Cr containing PVD-MoS₂ coatings with an optimized structure were tested under varying environments including hydrogen gas and cryogenic temperatures. Results of the most promising variant are presented in this paper. KW - Solid lubrication KW - MoS2 KW - Extreme environments KW - Hydrogen KW - Cryogenic einvironment PY - 2016 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-381460 DO - https://doi.org/10.3390/lubricants4030032 SN - 2075-4442 VL - 32 IS - 4 PB - MPPI AG CY - Basel, Switzerland AN - OPUS4-38146 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Pirker, F. A1 - Toth, I. A1 - Cihak-Bayr, U. A1 - Grundtner, R. A1 - Vernes, A. A1 - Benedicto, J. A1 - Spaltmann, Dirk A1 - Gradt, Thomas A1 - Alberdi, A. A1 - Alonso, I. A1 - Bayón, R. A1 - Igartua, A. A1 - García, Á. A1 - Pagano, F. A1 - Bravo, I. A1 - Kogia, M. A1 - Dykeman, D. A1 - Liedtke, S. A1 - Minami, I. A1 - Nyberg, E. A1 - Soivio, K. A1 - Ronkainen, H. A1 - Majaniemi, S. A1 - Heino, V. A1 - Gkagkas, K. A1 - Mont, L. A1 - Amigorena, I. T1 - Tribological characterisation services for materials - i-TRIBOMAT N2 - Um den Entwicklungsprozess von neuen Komponenten zu beschleunigen, ist die Vorrausage der Eigenschaften der eingesetzten Werkstoffe im Betrieb der Komponenten von enormer Bedeutung. Um neue Werkstoffe hinsichtlich Ihrer Performance (in einer Komponente) bewerten zu können, ist deshalb die Entwicklung neuer innovativer Methoden notwendig. Diese Methoden können auch unter dem Begriff „lab-to-field“ oder „materials“ – up-scaling zusammengefasst werden. D. h. Werkstoffe werden im Labor charakterisiert, und deren Eigenschaften mittels z.B. Simulation auf die Komponentenperformance hochskaliert (upscaling). i-TRIBOMAT ist ein EU gefördertes Projekt (H2020, GA Nr. 814494) mit dem Ziel ein Open Innovation Test Bed für tribologische Werkstoffcharakterisierung aufzubauen und entsprechende Services von der tribologischen Charakterisierung neuer Werkstoffe bis hin zu Simulationsmodellen zur Vorrausage der Perfomance von Komponenten der Industrie anzubieten. Durch die Bündelung von Knowhow und Infrastruktur zu Charakterisierung sowie den Aufbau einer digitalen Plattform, wird i-TRIBOMAT das weltgrößte Open Innovation Test Bed für tribologische Werkstoffcharakterisierung. N2 - The prediction of the properties of the materials used in the operation of components is of enormous importance, in order to accelerate the development process of new components. To evaluate new materials in terms of their performance (in a component), the development of new innovative methods is necessary. These methods can also be summarized under the term lab-to-field or materials – upscaling, meaning materials being characterised in a laboratory and their properties being upscaled to the component performance by means of e.g. simulation. i-TRIBOMAT is a EU funded project (H2020, GA Nr. 814494) aiming at building an Open Innovation Test Bed for tribological material characterization and offering corresponding services from tribological characterization of new materials to simulation models for predicting the performance of industrial components. By bundling the infrastructure, know-how for characterization and building a digital platform, i-TRIBOMAT becomes the world’s largest open innovation test bed for tribological material characterization. T2 - 22nd International Colloquium Tribology CY - Esslingen, Germany DA - 28.01.2020 KW - Tribologie KW - Lab-to-field up-scaling KW - Werkstoffdatenbank KW - Geteilte Infrastruktur KW - Tribo-Analytik KW - Intelligente tribologische Werkstoffcharakterisierung KW - Lab-to-field upscaling KW - Tribology KW - Intelligent tribological material characterization KW - Materials database KW - Shared infrastruture KW - Tribo-analytics PY - 2020 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-576762 DO - https://doi.org/10.30419/TuS-2020-0026 SN - 0724-3472 SN - 2941-0908 VL - 67 IS - 5-6 SP - 35 EP - 50 PB - Expert CY - Tübingen AN - OPUS4-57676 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Michalchuk, Adam A1 - Boldyreva, E. A1 - Belenguer, A. M. A1 - Emmerling, Franziska A1 - Boldyrev, V. V. T1 - Tribochemistry, mechanical alloying, mechanochemistry: what is in a name? N2 - Over the decades, the application of mechanical force to influence chemical reactions has been called by various names: mechanochemistry, tribochemistry, mechanical alloying, to name but a few. The evolution of these terms has largely mirrored the understanding of the field. But what is meant by these terms, why have they evolved, and does it really matter how a process is called? Which parameters should be defined to describe unambiguously the experimental conditions such that others can reproduce the results, or to allow a meaningful comparison between processes explored under different conditions? Can the information on the process be encoded in a clear, concise, and self-explanatory way? We address these questions in this Opinion contribution, which we hope will spark timely and constructive discussion across the international mechanochemistry community. KW - Mechanochemistry KW - Tribochemistry KW - Mechanical alloying KW - Tribology KW - Mechanical activation KW - Nomenclature KW - Mechanochemical pictographs PY - 2021 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-523291 DO - https://doi.org/10.3389/fchem.2021.685789 SN - 2296-2646 VL - 9 SP - 1 EP - 29 PB - Frontiers Media CY - Lausanne AN - OPUS4-52329 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Sprengel, Maximilian A1 - Mohr, Gunther A1 - Altenburg, Simon A1 - Evans, Alexander A1 - Serrano-Munoz, Itziar A1 - Kromm, Arne A1 - Pirling, T. A1 - Bruno, Giovanni A1 - Kannengießer, Thomas T1 - Triaxial Residual Stress in Laser Powder Bed Fused 316L: Effects of Interlayer Time and Scanning Velocity N2 - The triaxial distribution of the residual stress in laser powder bed fused austenitic steel 316L was determined by X-ray and neutron diffraction. The residual stress analysis results were linked to the thermal history of the specimens, which were manufactured with varying inter-layer-times and scanning velocities. A clear link between the in-process temperature of the specimens and the residual stress was found, based on in-situ monitoring data. KW - Stainless Steel KW - AGIL KW - Residual Stress KW - X-ray and Neutron Diffraction KW - Additive Manufacturing PY - 2022 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-542620 DO - https://doi.org/10.1002/adem.202101330 SP - 1 EP - 13 PB - Wiley-VCH GmbH AN - OPUS4-54262 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Recknagel, Sebastian A1 - Bresch, Harald A1 - Kipphardt, Heinrich A1 - Resch-Genger, Ute A1 - Koch, Matthias A1 - Rosner, M. T1 - Trends in selected fields of reference material production N2 - For more than 110 years, BAM has been producing reference materials for a wide range of application fields. With the development of new analytical methods and new applications as well as continuously emerging more stringent requirements of laboratory accreditation with regard to quality control and metrological traceability, the demand and requirements for reference materials are increasing. This trend article gives an overview of general developments in the field of reference materials as well as developments in selected fields of application in which BAM is active. This includes inorganic and metal analysis, gas analysis, food and consumer products, and geological samples. In addition to these more traditional fields of application, developments in the areas of optical spectroscopy, particulary fluorescence methods, and nanomaterials are considered. T2 - 150 years BAM: Science with impact CY - Berlin, Germany DA - 01.01.2021 KW - Reference material KW - ISO REMCO KW - Gas analysis KW - Food KW - Nanomaterials KW - Fluorescence PY - 2022 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-548407 DO - https://doi.org/10.1007/s00216-022-03996-7 SN - 1618-2642 SN - 1618-2650 VL - 414 IS - Topical collection: Analytical methods and applications in the materials and life sciences SP - 4281 EP - 4289 PB - Springer CY - Berlin AN - OPUS4-54840 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Rhode, Michael A1 - Nietzke, Jonathan A1 - Mente, Tobias T1 - Trapping and diffusion in high-pressure hydrogen charged CoCrFeMnNi high entropy alloy compared to austenitic steel 316L N2 - High entropy alloys (HEAs) have attracted considerable research attention as potential substitute materials for austenitic steels in high-pressure hydrogen environments. The corresponding hydrogen absorption, diffusion and trapping has received less scientific attention. Therefore, the CoCrFeMnNi-HEA was investigated and compared to an austenitic steel AISI 316L. Both were subjected to high-pressure hydrogen charging at 200 bar and 1000 bar. Thermal Desorption Analysis (TDA) was used to clarify the specific desorption behavior and hydrogen trapping. For this purpose, the underlying TDA spectra were analyzed in terms of a reasonable peak deconvolution into a defined number of peaks and the activation energies for the respective and predominant hydrogen trapping sites were then calculated. Both materials show comparable hydrogen diffusivity. However, there were significant differences in the absorbed hydrogen concentrations at both charging pressures. The calculated activation energies suggest strong hydrogen trapping in the CoCrFeMnNi-HEA. KW - High-entropy alloy KW - Hydrogen diffusion KW - Trapping KW - High-pressure charging KW - Thermal desorption analysis PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-611901 DO - https://doi.org/10.1016/j.ijhydene.2024.09.393 SN - 0360-3199 VL - 89 IS - 89 SP - 772 EP - 782 PB - Elsevier B.V. CY - Amsterdam, Netherlands AN - OPUS4-61190 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kraus, David A1 - Trappe, Volker T1 - Transverse damage in glass fiber reinforced polymer under thermo-mechanical loading N2 - In this study, the thermomechanical damage behavior of a glass fiber reinforced polymer material is investigated. The coefficients of thermal expansion of the composite as well as the matrix are measured in a wide temperature range. Quasi-static experiments with neat resin, unidirectional and multidirectional laminates are performed as well as fatigue experiments in a temperature range from 213 K to 343 K. This study focusses on the matrix damage due to fiber-parallel loading. A correlation between matrix effort, the dilatational strain energy of the matrix and the damage state of the specimen is demonstrated. It is shown that a fatigue life assessment can be performed with the aid of a temperature-independent master fatigue curve. KW - Composite KW - Glass fiber reinforced polymer KW - Thermo-mechanics KW - Fatigue KW - Damage KW - Temperature PY - 2021 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-527462 DO - https://doi.org/10.1016/j.jcomc.2021.100147 SN - 2666-6820 VL - 5 SP - 100147 PB - Elsevier B.V. AN - OPUS4-52746 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Liepold, Philipp A1 - Kromm, Arne A1 - Kannengießer, Thomas T1 - Transvarestraint testing of high-strength steel filler metal N2 - High-strength steel welds are typically not known to be susceptible to Solidification Cracking (SC). However, modern light-weight constructions may force welding in highly restrained conditions, which are known to increase the probability of Solidification Crack (SC) emergence. In this article, the Modified Varestraint-Transvarestraint (MVT) test was used to evaluate the hot cracking susceptibility of welds made from high-strength, low-alloyed filler material. The materials tested include solid wires and a metal-cored wire. All wires are typically used in the Gas Metal Arc Welding (GMAW) process. Susceptibility to SC was measured over a wide range of welding parameters and bending speeds. Results show little affinity of the tested materials to SC. However, crack length increases in most cases with arc energy ( U ∙ I∕welding speed ) and welding speed. The length of the longest crack in one test specimen follows a similar trend until high welding speeds, where stagnation of crack length with changing arc energy was observed. KW - MVT KW - Varestraint KW - Transvarestraint KW - Solidification cracking KW - High-strength steel PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-630084 DO - https://doi.org/10.1007/s40194-025-02042-1 SN - 1878-6669 VL - 2025 SP - 1 EP - 12 PB - Springer CY - Berlin ; Heidelberg AN - OPUS4-63008 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Wetzel, Annica A1 - Morell, Daniel A1 - von der Au, Marcus A1 - Wittstock, Gunther A1 - Özcan Sandikcioglu, Özlem A1 - Witt, Julia T1 - Transpassive Metal Dissolution vs. Oxygen Evolution Reaction: Implication for Alloy Stability and Electrocatalysis T1 - Transpassive Metallauflösung vs. Sauerstoffentwicklung: Auswirkungen auf Legierungsstabilität und Elektrokatalyse N2 - Multi-principal element alloys (MPEAs) are gaining interest in corrosion and electrocatalysis research due to their electrochemical stability across a broad pH range and the design flexibility they offer. Using the equimolar CrCoNi alloy, we observe significant metal dissolution in a corrosive electrolyte (0.1 M NaCl, pH 2) concurrently with the oxygen evolution reaction (OER) in the transpassive region despite the absence of hysteresis in polarization curves or other obvious corrosion indicators. We present a characterization scheme to delineate the contribution of OER and alloy dissolution, using scanning electrochemical microscopy (SECM) for OER-onset detection, and quantitative chemical analysis with inductively coupled-mass spectrometry (ICP-MS) and ultraviolet visible light (UV-Vis) spectroscopy to elucidate metal dissolution processes. In-situ electrochemical atomic force microscopy (EC-AFM) revealed that the transpassive metal dissolution on CrCoNi is dominated by intergranular corrosion. These results have significant implications for the stability of MPEAs in corrosion systems, emphasizing the necessity of analytically determining metal ions released from MPEA electrodes into the electrolyte when evaluating Faradaic efficiencies of OER catalysts. The release of transition metal ions not only reduces the Faradaic efficiency of electrolyzers but may also cause poisoning and degradation of membranes in electrochemical reactors. N2 - Multi-Hauptelement-Legierungen (MPEAs) gewinnen in der Korrosions- und Elektrokatalyseforschung aufgrund ihrer elektrochemischen Stabilität über einen breiten pH-Bereich und der Vielfalt der möglichen chemischen Zusammensetzungen zunehmend an Interesse. In unseren Untersuchungen mit der äquimolaren CrCoNi-Legierung in einem sauren Elektrolyten (0.1 M NaCl, pH 2) beobachteten wir eine signifikante Metallauflösung, die mit der Sauerstoffentwicklungsreaktion (OER) im transpassiven Bereich einhergeht, obwohl in zyklischen Polarisationskurven keine Hysterese auftrat oder andere offensichtliche Korrosionsindikatoren vorlagen. In diesem Artikel wird ein Charakterisierungskonzept eingeführt, dass die Beiträge der OER und der Legierungsauflösung differenziert. Hierfür kommt die elektrochemische Rastermikroskopie (SECM) zum Nachweis des Beginns der OER und die quantitative chemische Analyse mit induktiv gekoppelter Massenspektrometrie (ICP-MS) und UV/Vis-Spektrometrie zur Aufklärung der Metallauflösungsprozesse zum Einsatz. Die elektrochemische In situ-Atomkraftmikroskopie (EC-AFM) zeigte, dass die intergranulare Korrosion der dominierende Mechanismus der transpassive Metallauflösung von CrCoNi ist. Diese Ergebnisse besitzen erhebliche Auswirkungen für die Beurteilung der Stabilität von MPEAs in Korrosionssystemen und der Stromausbeute von OER-Katalysatoren auf der Basis von MPEAs. Die Daten unterstreichen die Notwendigkeit der analytischen Bestimmung von Metallionen, die von MPEA-Elektroden freigesetzt werden. Die Freisetzung von Übergangsmetallionen verringert nicht nur die Stromausbeute von Elektrolyseuren, sondern kann zu einer Schädigung von Membranen in elektrochemischen Reaktoren führen. KW - Transpassive dissolution KW - Corrosion KW - Multi-prinicpal element alloys (MPEAs) KW - Passivation PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-597045 DO - https://doi.org/10.1002/anie.202317058 SP - 1 EP - 8 PB - Wiley VHC-Verlag AN - OPUS4-59704 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Wetzel, Annica A1 - Morell, Daniel A1 - von der Au, Marcus A1 - Witt, Julia A1 - Özcan Sandikcioglu, Özlem T1 - Transpassive Behavior of Equimolar CrMnFeCoNi and CrCoNi Multi‐Principal Element Alloys in an Alkaline NaCl Electrolyte N2 - AbstractWe investigated the corrosion properties and transpassive behavior of CrMnFeCoNi and CrCoNi multi‐principal element alloys (MPEAs) in a 0.1 M NaCl electrolyte at pH 12. By using SECM‐based tip substrate voltammetry (TSV) in combination with the chemical analysis of the electrolyte, we were able to differentiate between anodic metal dissolution and oxygen evolution in the transpassive range. Our investigations have shown that CrCoNi has a significantly higher corrosion resistance compared to CrMnFeCoNi. In the studied alkaline environment, a transpassive oxide film is formed on the surface of CrCoNi during secondary passivation. This transpassive oxide film appears to play a significant role in oxygen evolution, as the increase in TSV currents at the microelectrode coincides with the corresponding current density plateau of the voltametric current trace. The formation of the transpassive oxide film was not observed in previous studies conducted in acidic environments. Moreover, the alkaline electrolyte induced a positive hysteresis and mild pitting corrosion, in addition to intergranular corrosion, which was the sole corrosion process observed at acidic pH levels. These findings enhance the understanding of the processes governing the transpassivity of CrMnFeCoNi and CrCoNi MPEAs in alkaline environments and have potential implications for the development of application‐tailored corrosion‐resistant MPEAs. KW - Multi-principal element alloys KW - MPEA KW - Corrosion KW - Oxygen evolution reaction KW - Transpassive region PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-611594 DO - https://doi.org/10.1002/celc.202400346 SN - 2196-0216 SP - 1 EP - 9 PB - Wiley AN - OPUS4-61159 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Tokarski, T. A1 - Nolze, Gert A1 - Winkelmann, A. A1 - Rychlowski, L. A1 - Bala, P. A1 - Cios, G. T1 - Transmission Kikuchi diffraction: The impact of the signal-to-noise ratio N2 - Signal optimization for transmission Kikuchi diffraction (TKD) measurements in the scanning electron microscope is investigated by a comparison of different sample holder designs. An optimized design is presented, which uses a metal shield to efficiently trap the electron beam after transmission through the sample. For comparison, a second holder configuration allows a significant number of the transmitted electrons to scatter back from the surface of the sample holder onto the diffraction camera screen. It is shown that the secondary interaction with the sample holder leads to a significant increase in the background level, as well as to additional noise in the final Kikuchi diffraction signal. The clean TKD signal of the optimized holder design with reduced background scattering makes it possible to use small signal changes in the range of 2% of the camera full dynamic range. As is shown by an analysis of the power spectrum, the signal-to-noise ratio in the processed Kikuchi diffraction patterns is improved by an order of magnitude. As a result, the optimized design allows an increase in pattern signal to noise ratio which may lead to increase in measurement speed and indexing reliability. KW - EBSD KW - SEM KW - Transmission Kikuchi diffraction KW - Sample holder PY - 2021 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-531743 DO - https://doi.org/10.1016/j.ultramic.2021.113372 SN - 0304-3991 SN - 1879-2723 VL - 230 SP - 1 EP - 8 PB - Elsevier CY - Amsterdam AN - OPUS4-53174 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kotthoff, Lisa A1 - Keller, Julia A1 - Lörchner, Dominique A1 - Mekonnen, Tessema F. A1 - Koch, Matthias T1 - Transformation products of organic contaminants and residues - Overview of current simulation methods N2 - The formation of transformation products (TPs) from contaminants and residues is becoming an increasing focus of scientific community. All organic compounds can form different TPs, thus demonstrating the complexity and interdisciplinarity of this topic. The properties of TPs could stand in relation to the unchanged substance or be more harmful and persistent. To get important information about the generated TPs, methods are needed to simulate natural and manmade transformation processes. Current tools are based on metabolism studies, photochemical methods, electrochemical methods, and Fenton's reagent. Finally, most transformation processes are based on redox reactions. This review aims to compare these methods for structurally different compounds. The groups of pesticides, pharmaceuticals, brominated flame retardants, and mycotoxins were selected as important residues/contaminants relating to their worldwide occurrence and impact to health, food, and environmental safety issues. Thus, there is an increasing need for investigation of transformation processes and identification of TPs by fast and reliable methods. KW - Transformation product KW - Electrochemistry KW - Photochemistry KW - Fenton’s reagent PY - 2019 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-474108 DO - https://doi.org/10.3390/molecules24040753 SN - 1420-3049 VL - 24 IS - 4 SP - 753, 1 EP - 23 PB - MDPI CY - Basel AN - OPUS4-47410 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Weidner, Steffen A1 - Meyer, A. A1 - Kricheldorf, H. T1 - Transformation of poly(L-lactide) crystals composed of linear chains into crystals composed of cycles N2 - A poly(L-lactide) with a trifluoroethyl ester end group and an average degree of polymerization (DP) of 50 was synthesized by ROP of L-lactide initiated with trifluoroethanol. Small-angle X-ray scattering (SAXS) in combination with differential scanning calorimetry (DSC) measurements revealed an average crystal thickness of 13 nm, corresponding to 45 repeat units. This suggests that most crystallites were formed by extended PLA chains, and both flat surfaces were covered by CF3 groups. The crystalline PLAs were annealed at 140 or 160 °C in the presence of two catalysts: tin(II) 2-ethylhexanoate, (SnOct2) or dibutyltin bis(pentafluorophenoxide) (BuSnPhF). The chemical reactions, such as polycondensation and cyclization, proceeded in the solid state and were monitored by matrix-assisted laser desorption/ionization time-offlight (MALDI TOF) mass spectrometry and gel permeation chromatography (GPC) measurements. Under optimal conditions a large fraction of linear chains was transformed into crystallites composed of extended cycles. Additionally, MALDI TOF MS analysis of GPC fractions from samples annealed for 28 or 42 days detected chain elongation of the linear species up to a factor of 20. KW - Polylactide KW - MALDI-TOF MS KW - Crystalinity KW - Transesterification PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-597250 DO - https://doi.org/10.1039/D3PY01370G SN - 1759-9954 VL - 15 IS - 12 SP - 1173 EP - 1181 PB - Royal Society for Chemistry AN - OPUS4-59725 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Orf, I. A1 - Tenenboim, H. A1 - Omranian, N. A1 - Nikoloski, Z. A1 - Fernie, A. R. A1 - Lisec, Jan A1 - Brotman, Y. A1 - Bromke, M. A. T1 - Transcriptomic and Metabolomic Analysis of a Pseudomonas-Resistant versus a Susceptible Arabidopsis Accession N2 - Accessions of one plant species may show significantly different levels of susceptibility to stresses. The Arabidopsis thaliana accessions Col-0 and C24 differ significantly in their resistance to the pathogen Pseudomonas syringae pv. tomato (Pst). To help unravel the underlying mechanisms contributing to this naturally occurring variance in resistance to Pst, we analyzed changes in transcripts and compounds from primary and secondary metabolism of Col-0 and C24 at different time points after infection with Pst. Our results show that the differences in the resistance of Col-0 and C24 mainly involve mechanisms of salicylic-acid-dependent systemic acquired resistance, while responses of jasmonic-acid-dependent mechanisms are shared between the two accessions. In addition, arginine metabolism and differential activity of the biosynthesis pathways of aliphatic glucosinolates and indole glucosinolates may also contribute to the resistance. Thus, this study highlights the difference in the defense response strategies utilized by different genotypes. KW - Mass Spectrometry KW - Arabidopsis KW - Resistance PY - 2022 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-559549 DO - https://doi.org/10.3390/ijms232012087 VL - 23 IS - 20 SP - 1 EP - 27 PB - MDPI AN - OPUS4-55954 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Wurzler, Nina A1 - Schütter, J. D. A1 - Wagner, R. A1 - Dimper, M. A1 - Lützenkirchen-Hecht, D. A1 - Özcan Sandikcioglu, Özlem T1 - Trained to corrode: Cultivation in the presence of Fe(III) increases the electrochemical activity of iron reducing bacteria – An in situ electrochemical XANES study N2 - This paper reports results from in situ electrochemical X-ray absorption near-edge spectroscopy (XANES) studies of the corrosion processes on model thin iron films in the presence of iron reducing bacteria Shewanella putrefaciens. Here we investigate the electrochemical activity of two cultures grown in the presence and absence of Fe(III) citrate in the culture medium. The XANES spectra and the OCP data of the Fe sample incubated with the culture grown in absence of Fe(III) did not show any significant changes during twenty hours of monitoring. In the case of the culture grown in Fe(III) containing medium, an accelerated dissolution of the iron film was observed together with the formation of a mixed Fe(II)-Fe(III) hydroxide surface layer. The open circuit potential (OCP) steadily approached the free corrosion potential of iron in neutral chloride containing electrolytes, indicating a continuous dissolution process without passivation. KW - Microbiologically influenced corrosion KW - XANES KW - Electrochemistry KW - Iron reducing bacteria PY - 2020 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-505732 DO - https://doi.org/10.1016/j.elecom.2020.106673 VL - 112 SP - 106673 PB - Elsevier B.V. AN - OPUS4-50573 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Fadda, Marta A1 - Sacco, Alessio A1 - Altmann, Korinna A1 - Ciornii, Dmitri A1 - Milczewski, Frank A1 - Bañares, Miguel A. A1 - Portela, Raquel A1 - Giovannozzi, Andrea Mario A1 - Rossi, Andrea Mario T1 - Tracking nanoplastics in drinking water: a new frontier with the combination of dielectrophoresis and Raman spectroscopy N2 - Detection of micro- (MPs) and nanoplastics (NPs) in food and environmental matrices has been gaining relevance due to their potential toxicological effects on human health. While MPs have been detected in a wide range of complex matrices, suitable methods for the characterization and chemical identification of NPs are still lacking, primarily due to significant methodological challenges associated with their nano-specific physiochemical properties, including size distribution (1 nm – 1 µm), dynamic surface chemical changes, and carbon-based composition, which complicate their detection compared to engineered nanomaterials. To overcome the traditional limitations of spectroscopic techniques in terms of spatial resolution and sensitivity at the sub-micrometer level, a novel label-free methodology is presented for specifically identifying the chemical composition of NPs directly in suspension by combining Raman spectroscopy with dielectrophoresis (DEP). Using a custom-built device, small volumes of NPs are injected into a dielectrophoretic cell and locally trapped by DEP forces to fill the Raman confocal volume, facilitating their detection and identification, and providing high signal-to-noise ratio Raman spectra for more reliable analysis. This approach was successfully applied to both Milli-Q water and a commercial brand of drinking water, enabling the rapid identification of various types of NPs with different sizes and polymer compositions at concentrations as low as 20 µg/mL. These included certified reference polystyrene beads ranging from 800 to 60 nm in diameter, as well as polydisperse NPs, more representative of real samples in terms of size distribution and polymer type, such as polyethylene (450 nm), polypropylene (180 nm), and polyethylene terephthalate (100 nm). Moreover, the chemical fingerprint of each NPs was thoroughly investigated and compared with the corresponding bulk polymers, highlighting possible changes in the Raman bands due to surface oxidation or nanometer-scale effect. Therefore, this innovative method can be considered a valuable approach for addressing gaps in the detection and identification of NPs, as well as for monitoring their dynamic phisiochemical changes in real matrices. KW - Nanoplastics KW - Water contaminants KW - Raman microspectroscopy KW - Dielectrophoresis PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-633658 DO - https://doi.org/10.1186/s43591-025-00131-y SN - 2662-4966 VL - 5 IS - 1 SP - 1 EP - 11 PB - Springer Science and Business Media LLC AN - OPUS4-63365 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Pech, S. A1 - Rehberg, M. A1 - Janke, R. A1 - Benndorf, D. A1 - Genzel, Y. A1 - Muth, Thilo A1 - Sickmann, A. A1 - Rapp, E. A1 - Reichl, U. T1 - Tracking changes in adaptation to suspension growth for MDCK cells: cell growth correlates with levels of metabolites, enzymes and proteins N2 - Adaptations of animal cells to growth in suspension culture concern in particular viral vaccine production, where very specific aspects of virus-host cell interaction need to be taken into account to achieve high cell specific yields and overall process productivity. So far, the complexity of alterations on the metabolism, enzyme, and proteome level required for adaptation is only poorly understood. In this study, for the first time, we combined several complex analytical approaches with the aim to track cellular changes on different levels and to unravel interconnections and correlations. Therefore, a Madin-Darby canine kidney (MDCK) suspension cell line, adapted earlier to growth in suspension, was cultivated in a 1-L bioreactor. Cell concentrations and cell volumes, extracellular metabolite concentrations, and intracellular enzyme activities were determined. The experimental data set was used as the input for a segregated growth model that was already applied to describe the growth dynamics of the parental adherent cell line. In addition, the cellular proteome was analyzed by liquid chromatography coupled to tandem mass spectrometry using a label-free protein quantification method to unravel altered cellular processes for the suspension and the adherent cell line. Four regulatory mechanisms were identified as a response of the adaptation of adherent MDCK cells to growth in suspension. These regulatory mechanisms were linked to the proteins caveolin, cadherin-1, and pirin. Combining cell, metabolite, enzyme, and protein measurements with mathematical modeling generated a more holistic view on cellular processes involved in the adaptation of an adherent cell line to suspension growth. KW - MDCK cell KW - Proteome KW - Metabolism KW - Enzyme activity KW - Suspension growth PY - 2021 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-522070 DO - https://doi.org/10.1007/s00253-021-11150-z VL - 105 IS - 5 SP - 1861 EP - 1874 PB - Springer AN - OPUS4-52207 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Wonneberger, R. A1 - Gräf, S. A1 - Bonse, Jörn A1 - Wisniewski, W. A1 - Freiberg, K. A1 - Hafermann, M. A1 - Ronning, C. A1 - Müller, F. A. A1 - Undisz, A. T1 - Tracing the Formation of Femtosecond Laser-Induced Periodic Surface Structures (LIPSS) by Implanted Markers N2 - The generation of laser-induced periodic surface structures (LIPSS) using femtosecond lasers facilitates the engineering of material surfaces with tailored functional properties. Numerous aspects of their complex formation process are still under debate, despite intensive theoretical and experimental research in recent decades. This particularly concerns the challenge of verifying approaches based on electromagnetic effects or hydrodynamic processes by experiment. In the present study, a marker experiment is designed to conclude on the formation of LIPSS. Well-defined concentration depth profiles of 55Mn+- and 14N+-ions were generated below the polished surface of a cast Mn- and Si-free stainless steel AISI 316L using ion implantation. Before and after LIPSS generation, marker concentration depth profiles and the sample microstructure were evaluated by using transmission electron microscopy techniques. It is shown that LIPSS predominantly formed by material removal through locally varying ablation. Local melting and resolidification with the redistribution of the material occurred to a lesser extent. The experimental design gives quantitative access to the modulation depth with a nanometer resolution and is a promising approach for broader studies of the interactions of laser beams and material surfaces. Tracing LIPSS formation enables to unambiguously identify governing aspects, consequently guiding the path to improved processing regarding reproducibility, periodicity, and alignment. KW - Laser-induced periodic surface structures (LIPSS) KW - Femtosecond laser processing KW - Ion implantation KW - Transmission Electron Microscopy (TEM) KW - Stainless steel PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-623990 DO - https://doi.org/10.1021/acsami.4c14777 SN - 1944-8244 (Print) SN - 1944-8252 (Online) VL - 17 IS - 1 SP - 2462 EP - 2468 PB - ACS Publications AN - OPUS4-62399 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Plouffe, A. A1 - Lee, R. G. A1 - Byrne, K. A1 - Kjarsgaard, I. M. A1 - Petts, D. C. A1 - Wilton, D.H.C. A1 - Ferbey, T. A1 - Oelze, Marcus T1 - Tracing Detrital Epidote Derived from Alteration Halos to Porphyry Cu Deposits in Glaciated Terrains: The Search for Covered Mineralization N2 - Distal alteration related to porphyry Cu mineralization is typically characterized by an abundance of green minerals, such as epidote, tremolite, and chlorite, within the propylitic and sodic-calcic alteration zones and extends far outside (>1 km) the mineralized zone(s). Glacial erosion and dispersal derived from rocks affected by propylitic and sodic-calcic alteration have resulted in the development of extensive dispersal trains of epidote in till (glacial sediment) that can reach 8 to 330 km2 as observed at four porphyry Cu study sites in the Quesnel terrane of south-central British Columbia: Highland Valley Copper, Gibraltar, Mount Polley, and Woodjam deposits. At each of these sites, epidote is more abundant in heavy mineral concentrates of till collected directly over and down-ice from mineralization and associated alteration. Epidote grains in till with >0.6 ppm Sb and >8 ppm As (as determined by laser ablation-inductively coupled plasma-mass spectrometry) are attributed to a porphyry alteration provenance. There is a greater abundance of epidote grains with high concentrations of trace elements (>12 ppm Cu, >2,700 ppm Mn, >7 ppm Zn, and >37 ppm Pb) in each porphyry district com� pared to background regions. This trace element signature recorded in till epidote grains is heterogeneously distributed in these districts and is interpreted to reflect varying degrees of metal enrichment from a porphyry fluid source. Tracing the source of the epidote in the till (i.e., geochemically tying it to porphyry-related propy� litic and/or sodic-calcic alteration), coupled with porphyry vectoring tools in bedrock, will aid in the detection of concealed porphyry Cu mineralization in glaciated terrains. KW - Indicator minerals KW - Porphyry Cu deposits KW - Epidote KW - Glaciated terrains KW - Propylitic alteration PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-635209 DO - https://doi.org/10.5382/econgeo.5049 SN - 1554-0774 VL - 119 IS - 2 SP - 305 EP - 329 PB - Society of Economic Geologists, Inc. AN - OPUS4-63520 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Bayat, Mehmet Emin A1 - Kipphardt, Heinrich A1 - Tiebe, Carlo A1 - Tuma, Dirk A1 - Engelhard, Carsten T1 - Trace-Level Ammonia–Water Interactions in Hydrogen: Challenges in Gas Purity Analysis Using Optical-Feedback Cavity-Enhanced Absorption Spectroscopy (OF-CEAS) N2 - Ammonia is a critical impurity in hydrogen fuel due to its irreversible poisoning effect on proton exchange membrane fuel cells. Therefore, international standards (e.g., ISO 14687) set a stringent threshold of 100 nmol/mol. Furthermore, with the growing potential use of ammonia as a hydrogen carrier, its accurate quantification is becoming increasingly important. However, the presence of trace humidity poses analytical challenges, as ammonia may interact with water or interfaces, thereby affecting its detectability. Therefore, the goal of this work is to enable accurate trace ammonia quantification for hydrogen purity measurements through fundamental studies of the methodological challenges. Here, low-pressure sampling (ultra)long-path Optical-Feedback Cavity-Enhanced Absorption Spectroscopy (OF-CEAS) was applied with an effective optical path length of approximately 6.17 km. We studied three average amounts of ammonia: (38.2 ± 0.8) nmol/mol, (74.8 ± 0.7) nmol/mol, and (112.1 ± 1.2) nmol/mol. Furthermore, these amounts were investigated at trace-humidity levels ranging from 0.8 to 8.5 ppmV. We observed a systematic, nonlinear, and humidity-dependent positive measurement bias of up to + (1.0 ± 0.2) nmol/mol at the maximum investigated trace-humidity volume fraction of 8.5 ppmV. This bias was not caused by spectral interference but rather by water-induced accumulation of ammonia within the optical cavity. Moreover, time-resolved measurements in the presence of trace ammonia showed that water desorption follows first-order kinetics, whereas water adsorption followed mixed-order kinetics with an apparent reaction order of 1.57 ± 0.03. Distinct hydration states of surface-bound ammonia were identified, whereas under dry conditions and with increasing amounts of ammonia, enhanced surface adhesion through intermolecular clustering was observed. In addition, the presence of ammonium species within the sorption layer was indirectly confirmed by our experiments. In conclusion, we provide a deeper insight into trace-level ammonia–water interactions and establish a framework for optimizing methodologies, particularly for (ultra)long-path optical gas measurement systems. KW - Ammonia KW - Hydrogen KW - OF-CEAS KW - Humidity KW - Surface Interactions KW - Adsorption PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-643627 DO - https://doi.org/10.1021/acsmeasuresciau.5c00105 SN - 2694-250X SP - 1 EP - 15 PB - American Chemical Society (ACS) AN - OPUS4-64362 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Sittner, Jonathan A1 - Götze, Jens A1 - Müller, Axel A1 - Renno, Axel D. A1 - Ziegenrücker, René A1 - Pan, Yuanming T1 - Trace element analysis and luminescence behavior of quartz in pegmatites of the Tørdal Region, Norway N2 - This publication presents a study on the mineral chemistry and luminescence properties of quartz samples from pegmatites of the Tørdal region in Norway. A total of 12 samples were analyzed using Secondary Ion Mass Spectrometry (SIMS), Electron Paramagnetic Resonance Spectroscopy (EPR), and Cathodoluminescence (CL) to gain insights into their trace element concentration and distribution as well as their luminescence behavior. The samples are characterized by different Cl emissions at 450 nm, 500 nm 650 nm and an additional shoulder at 390 nm, which is only partially visible due to the absorption of the glass optics. Of these luminescence bands, the 500 nm band is the most dominant in most samples and it is characterized by an initial blue-green luminescence, which is not stable under electron irradiation. Moreover, it is characterized by a heterogeneous distribution within the samples. This luminescence can be mostly assigned to [AlO4/M+]0 defects, with charge compensation mostly achieved by Li+. Analyses by EPR spectroscopy prove the dominance of structurally bound Al, Li, and Ti ions in the investigated samples. Further analyses using SIMS mapping demonstrate that Na and K are mainly bound to micro fractures or inclusions, suggesting a limited role in the compensation of the luminescence centers. Additionally, the SIMS mappings show that some samples contain Al-rich clusters of 10 to 20 µm in diameter, whereas other trace elements are characterized by a homogeneous distribution. These clusters correspond to bright luminescence areas in size and shape and could potentially indicate H+ compensated [AlO4/M+]0 defects. KW - Quartz KW - Trace elements KW - SIMS KW - Cathodoluminescence KW - EPR KW - Tørdal KW - Pegmatite PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-612529 DO - https://doi.org/10.1016/j.chemgeo.2024.122427 VL - 670 SP - 1 EP - 15 PB - Elsevier BV AN - OPUS4-61252 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Dariz, P. A1 - Schmid, Thomas T1 - Trace compounds in Early Medieval Egyptian blue carry information on provenance, manufacture, application, and ageing N2 - Only a few scientific evidences for the use of Egyptian blue in Early Medieval wall paintings in Central and Southern Europe have been reported so far. The monochrome blue fragment discussed here belongs to the second church building of St. Peter above Gratsch (South Tyrol, Northern Italy, fifth/ sixth century A.D.). Beyond cuprorivaite and carbon black (underpainting), 26 accessory minerals down to trace levels were detected by means of Raman microspectroscopy, providing unprecedented insights into the raw materials blend and conversion reactions during preparation, application, and ageing of the pigment. In conjunction with archaeological evidences for the manufacture of Egyptian blue in Cumae and Liternum and the concordant statements of the antique Roman writers Vitruvius and Pliny the Elder, natural impurities of the quartz sand speak for a pigment produced at the northern Phlegrean Fields (Campania, Southern Italy). Chalcocite (and chalcopyrite) suggest the use of a sulphidic copper ore, and water-insoluble salts a mixed-alkaline flux in the form of plant ash. Not fully reacted quartz crystals partly intergrown with cuprorivaite and only minimal traces of silicate glass portend solid-state reactions predominating the chemical reactions during synthesis, while the melting of the raw materials into glass most likely played a negligible role. KW - Egyptian blue KW - Raman microspectroscopy KW - Spectoscopic imaging KW - Cuprorivaite KW - Amorphous carbon PY - 2021 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-537591 DO - https://doi.org/10.1038/s41598-021-90759-6 VL - 11 SP - 1 EP - 12 PB - Nature Portfolio AN - OPUS4-53759 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Keller, Julia A1 - Borzekowski, Antje A1 - Haase, H. A1 - Menzel, R. A1 - Rueß, L. A1 - Koch, Matthias T1 - Toxicity assay for citrinin, zearalenone and zearalenone-14-sulfate using the nematode Caenorhabditis elegans as model organism N2 - To keep pace with the rising number of detected mycotoxins, there is a growing need for fast and reliable toxicity tests to assess the potential threat to food safety. Toxicity tests with the bacterial-feeding nematode Caenorhabditis elegans as model organism are well established. In this study the C. elegans wildtype strain N2 (var. Bristol) was used to investigate the toxic effects of the food-relevant mycotoxins citrinin (CIT) and zearalenone-14-sulfate (ZEA-14-S) and zearalenone (ZEA) on different life cycle parameters including reproduction, thermal and oxidative stress resistance and lifespan. The metabolization of the mycotoxins by the nematodes in vivo was investigated using HPLC-MS/MS. ZEA was metabolized in vivo to the reduced isomers α-zearalenol (α-ZEL) and β-ZEL. ZEA 14-S was reduced to α-/β-ZEL 14-sulfate and CIT was metabolized to mono-hydroxylated CIT. All mycotoxins tested led to a significant decrease in the number of nematode offspring produced. ZEA and CIT displayed negative effects on stress tolerance levels and for CIT an additional shortening of the mean lifespan was observed. In the case of ZEA-14-S, however, the mean lifespan was prolonged. The presented study shows the applicability of C. elegans for toxicity testing of emerging food mycotoxins for the purpose of assigning potential health threats. KW - Mycotoxins KW - Metabolization KW - Toxicity testing KW - Biotests PY - 2018 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-455772 DO - https://doi.org/10.3390/toxins10070284 VL - 10 IS - 7 SP - 284, 1 EP - 12 PB - MDPI AN - OPUS4-45577 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kieserling, Helena A1 - Sieg, Holger A1 - Heilscher, Jasmin A1 - Drusch, Stephan A1 - Braeuning, Albert A1 - Thünemann, Andreas A1 - Rohn, Sascha T1 - Towards Understanding Particle-Protein Complexes: Physicochemical, Structural, and Cellbiological Characterization of β-Lactoglobulin Interactions with Silica, Polylactic Acid, and Polyethylene Terephthalate Nanoparticles N2 - Nanoplastic particles and their additives are increasingly present in the food chain, interacting with biomacromolecules with not yet known consequences. A protein corona forms around the particles in these usually complex matrices, primarily with a first contact at surface-active proteins. However, systematic studies on the interactions between the particles and proteins –especially regarding protein affinity and structural changes due to surface properties like polarity – are limited. It is also unclear whether the protein corona can "mask" the particles, mimic protein properties, and induce cytotoxic effects when internalized by mammalian cells. This study aimed at investigating the physicochemical properties of model particle-protein complexes, the structural changes of adsorbed proteins, and their effects on Caco-2 cells. Whey protein β-lactoglobulin (β-Lg) was used as a well-characterized model protein and studied in a mixture with nanoparticles of varying polarity, specifically silica, polylactic acid (PLA), and polyethylene terephthalate (PET). The physicochemical analyses included measurements of the hydrodynamic diameter and the zeta potential, while the protein conformational changes were analyzed using Fourier-transform-infrared spectroscopy (FTIR) and intrinsic fluorescence. Cellular uptake in Caco-2 cells was assessed through flow cytometry, cell viability was measured using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium-bromide (MTT) assay, and cellular impedance was analyzed with xCELLigence® technology. The results indicated that β-Lg had the highest affinity for hydrophilic silica particles, forming silica-β-Lg complexes and large aggregates through electrostatic interactions. The affinity decreased for PLA and was lowest for hydrophobic PET, which formed smaller complexes. Adsorption onto silica caused partial unfolding and refolding of β-Lg. The silica-β-Lg complexes were internalized by Caco-2 cells, impairing cell proliferation. In contrast, PLA- and PET-protein complexes were not internalized, though PLA complexes slightly reduced cell viability. This study enhances our understanding of protein adsorption on nanoparticles and its potential biological effects. KW - Nanoplastics KW - Microplastics KW - Reference materials KW - Scattering KW - DLS PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-630093 DO - https://doi.org/10.1016/j.colsurfb.2025.114702 SN - 1873-4367 VL - 253 SP - 1 EP - 12 PB - Elsevier BV CY - Amsterdam AN - OPUS4-63009 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Jaeger, Carsten A1 - Lisec, Jan T1 - Towards Unbiased Evaluation of Ionization Performance in LC-HRMS Metabolomics Method Development N2 - As metabolomics increasingly finds its way from basic science into applied and regulatory environments, analytical demands on nontargeted mass spectrometric detection methods continue to rise. In addition to improved chemical comprehensiveness, current developments aim at enhanced robustness and repeatability to allow long-term, inter-study, and meta-analyses. Comprehensive metabolomics relies on electrospray ionization (ESI) as the most versatile ionization technique, and recent liquid chromatography-high resolution mass spectrometry (LC-HRMS) instrumentation continues to overcome technical limitations that have hindered the adoption of ESI for applications in the past. Still, developing and standardizing nontargeted ESI methods and instrumental setups remains costly in terms of time and required chemicals, as large panels of metabolite standards are needed to reflect biochemical diversity. In this paper, we investigated in how far a nontargeted pilot experiment, consisting only of a few measurements of a test sample dilution series and comprehensive statistical analysis, can replace conventional targeted evaluation procedures. To examine this potential, two instrumental ESI ion source setups were compared, reflecting a common scenario in practical method development. Two types of feature evaluations were performed, (a) summary statistics solely involving feature intensity values, and (b) analyses additionally including chemical interpretation. Results were compared in detail to a targeted evaluation of a large metabolite standard panel. We reflect on the advantages and shortcomings of both strategies in the context of current harmonization initiatives in the metabolomics field. KW - Mass Spectrometry KW - Non-targeted analysis KW - Method development PY - 2022 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-548065 DO - https://doi.org/10.3390/metabo12050426 VL - 12 IS - 5 SP - 1 EP - 13 PB - MDPI AN - OPUS4-54806 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Sprengel, Maximilian A1 - Ulbricht, Alexander A1 - Evans, Alexander A1 - Kromm, Arne A1 - Sommer, Konstantin A1 - Werner, Tiago A1 - Kelleher, J. A1 - Bruno, Giovanni A1 - Kannengießer, Thomas T1 - Towards the optimization of post-laser powder bed fusion stress-relieve treatments of stainless steel 316L N2 - This study reports on the stress relaxation potential of stress-relieving heat treatments for laser powder bed fused 316L. The residual stress is monitored non-destructively using neutron diffraction before and after the heat treatment. Moreover, the evolution of the microstructure is analysed using scanning electron microscopy. The results show, that a strong relaxation of the residual stress is obtained when applying a heat treatment temperature at 900°C. However, the loss of the cellular substructure needs to be considered when applying this heat treatment strategy. KW - Residual stress KW - Additive manufacturing KW - Neutron diffraction KW - Projekt AGIL - Alterung additiv gefertigter metallischer Materialien und Komponenten PY - 2021 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-536045 DO - https://doi.org/10.1007/s11661-021-06472-6 SN - 1543-1940 VL - 52 IS - 12 SP - 5342 EP - 5356 PB - Springer CY - Boston AN - OPUS4-53604 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Semenova, Aleksandra A1 - Spitzer Sra, Stefan H. A1 - Dvorakova, Barbora A1 - Askar, Enis A1 - Funnemann, Patrick A1 - Hermanns, Roy T.E. A1 - Jankuj, Vojtech A1 - Vignes, Alexis A1 - Kuracina, Richard A1 - Szabova, Zuzana A1 - Norman, Frederik A1 - Gabel, Dieter A1 - Danzi, Enrico A1 - Makarova, Ekaterina A1 - Lorenzon, Ivan A1 - Toman, Adrian A1 - Adamus, Wojciech A1 - Hessels, Conrad T1 - Towards standardized safety protocols for iron-based energy carriers: International alignment through round robin testing on safety characteristics N2 - Background Iron powder appears to be a promising solution for long-term energy storage and (inter-) continental transport, as it is safe to store and does not require energy to maintain its state, unlike, for instance, liquefied hydrogen. However, while the fundamental research is well underway, large-scale implementation is still in its early stages, with a growing number of promising demonstrators emerging. Methods This article contributes to the large-scale implementation of iron as an energy carrier by presenting a round-robin test of four iron powders currently used in research and larger-scale demonstrators. These powders were tested on their safety characteristics in the standard 20 L apparatus across eight European countries. Results The resulting data are intended to support future standardization efforts using different iron samples as standardized fuel. All tested powders were classified either as non-explosible or as belonging to the category of marginally explosible dusts (Class 1). This provides a clear picture of the level of explosion protection measures that need to be considered for the safe use of iron powders in energy carrier applications. Conclusions Along with that, the study detected variations in the results and pointed to shortcomings in the current standards that may cause such discrepancies. These findings emphasize the importance of improving testing procedures to support standardization and ensure the safe use of iron powder as an energy carrier using an a-priori-approach rather than subsequent testing. KW - Explosion protection KW - Energy carrier KW - Safety characteristics PY - 2026 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-655761 DO - https://doi.org/10.12688/openreseurope.22839.1 SN - 2732-5121 VL - 6 SP - 1 EP - 20 PB - F1000 Research Ltd AN - OPUS4-65576 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Karapanagiotis, Christos A1 - Heimann, Jan A1 - Duffner, Eric A1 - Charmi, Amir A1 - Schukar, Marcus A1 - Hashemi, Seyedreza A1 - Prager, Jens T1 - Towards predictive maintenance of hydrogen pressure vessels based on multi-sensor data fusion and digital twin modeling N2 - Hydrogen pressure vessels are among the most essential components for reliable hydrogen technology. Under current regulations, a mostly conservative strategy is employed, restricting the usage time of hydrogen pressure vessels without providing information on the real remaining lifetime. During the service life, pressure vessels are inspected periodically. However, no established method that can provide continuous monitoring or information on the remaining safe service life of the vessel. In this paper, we propose a sensor network for Structural Health Monitoring (SHM) of hydrogen pressure vessels where data from all sensors are collected and centrally evaluated. Specifically, we integrate three different SHM sensing technologies namely Guided Wave ultrasonics (GW), Acoustic Emission testing (AT), and distributed Fiber Optic Sensing (FOS). This integrated approach offers significantly more information and could therefore enable a transition from costly and time-consuming periodic inspections to more efficient and modern predictive maintenance strategies, including Artificial Intelligence (AI)-based evaluation. This does not only have a positive effect on the operational costs but enhances safety through early identification of critical conditions in the overall system in real-time. We demonstrate an experimental set-up of a lifetime test where a Type IV Composite Overwrapped Pressure Vessel (COPV) is investigated under cyclic loading instrumented with AT, FOS, and GW methods. We acquired data from the sensor network until the pressure vessel failed due to material degradation. The data collected using the three different SHM sensor technologies is planned to be evaluated individually, using data fusion, and AI. In the future, we aim to integrate the measurement setup into a hydrogen refueling station with the data stream implemented into a digital signal processing chain and a digital twin. T2 - 11th European Workshop on Structural Health Monitoring CY - Potsdam, Germany DA - 10.06.2024 KW - Acoustic emission KW - Ultrasonic guided waves KW - Fiber optic sensors KW - Hydrogen KW - Pressure vessels KW - Structural health monitoring KW - Machine learning PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-602764 UR - https://www.ndt.net/search/docs.php3?id=29702 SP - 1 EP - 8 PB - NDT.net AN - OPUS4-60276 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Karapanagiotis, Christos A1 - Heimann, Jan A1 - Duffner, Eric A1 - Charmi, Amir A1 - Schukar, Marcus A1 - Hashemi, Seyedreza A1 - Prager, Jens T1 - Towards predictive maintenance of hydrogen pressure vessels based on multi-sensor data N2 - In this paper, we report on a sensor network for structural health monitoring (SHM) of Type IV composite overwrapped pressure vessels (COPVs) designed for hydrogen storage. The sensor network consists of three different SHM sensing technologies: ultrasonic guided waves (GW), acoustic emission (AE) testing, and distributed fiber optic sensors (DFOS). We present an experimental setup for a lifetime test, where a COPV is subjected to cyclic loading. Data from all sensors are collected and centrally evaluated. The COPV failed after approximately 60,000 load cycles, and the sensor network proved capable of detecting and localizing the damage even before the failure of the COPV. This multi-sensor approach offers significantly more channels of information and could therefore enable a transition from costly and time-consuming periodic inspections to more efficient and modern predictive maintenance strategies, including artificial intelligence (AI)-based evaluation. This not only has a positive effect on operational c KW - Ffiber optic sensors KW - Acoustic emission KW - Guided waves KW - Hydrogen KW - Digital twin KW - Structural health monitoring PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-618948 DO - https://doi.org/10.58286/30513 SP - 1 EP - 8 PB - NDT.net AN - OPUS4-61894 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Küttenbaum, Stefan A1 - Braml, T. A1 - Taffe, A. A1 - Maack, Stefan ED - Li, J. ED - Spanos, D. ED - Chen, J. B. ED - Peng, Y. B. T1 - Towards NDT-supported decisions on the reliability of existing bridges N2 - A major advantage in the reassessment of existing structures is the possibility of including measured data that describe the actual properties and the current condition of the structure to be reassessed. Currently, the incorporation of such measured information is mostly unregulated. However, the use of measurement results is vitally important, since a measured data-based improvement of the computation models level of approximation can lead at least to more meaningful results, possibly to extended remaining life times of the structure and in the best case to a saving of resources. Conversely, not appreciating well measurable and relevant information can be equated with a waste of resources. In this paper, a concept for the comparable use of non-destructively measured data as basic variables in probabilistic reliability assessments is outlined and examined using a typical prestressed concrete road bridge as a case-study. An essential requirement is the calculation of measurement uncertainties in order to evaluate the quality of the measurement results comparably. In conclusion, the example of ultrasonic and radar measurement data is used to demonstrate the effects that the incorporation of the measured information has on the reliability of the structure. T2 - 13th International Conference on Structural Safety and Reliability (ICOSSAR 2021-2022) CY - Online meeting DA - 13.09.2022 KW - Measurement uncertainty KW - Reliability assessment KW - Existing structures KW - Concrete Bridge KW - Non-Destructive Testing (NDT) PY - 2023 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-583013 SP - 1 EP - 10 AN - OPUS4-58301 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kislenko, Evgeniia A1 - Incel, A. A1 - Gawlitza, Kornelia A1 - Sellergren, B. A1 - Rurack, Knut T1 - Towards molecularly imprinted polymers that respond to and capture phosphorylated tyrosine epitopes using fluorescent bis-urea and bis-imidazolium receptors N2 - Early detection of cancer is essential for successful treatment and improvement in patient prognosis. Deregulation of post-translational modifications (PTMs) of proteins, especially phosphorylation, is present in many types of cancer. Therefore, the development of materials for the rapid sensing of low abundant phosphorylated peptides in biological samples can be of great therapeutic value. In this work, we have synthesised fluorescent molecularly imprinted polymers (fMIPs) for the detection of the phosphorylated tyrosine epitope of ZAP70, a cancer biomarker. The polymers were grafted as nanometer-thin shells from functionalised submicron-sized silica particles using a reversible addition-fragmentation chain-transfer (RAFT) polymerisation. Employing the combination of fluorescent urea and intrinsically cationic bis-imidazolium receptor cross-linkers, we have developed fluorescent sensory particles, showing an imprinting factor (IF) of 5.0. The imprinted polymer can successfully distinguish between phosphorylated and non-phosphorylated tripeptides, reaching lower micromolar sensitivity in organic solvents and specifically capture unprotected peptide complements in a neutral buffer. Additionally, we have shown the importance of assessing the influence of counterions present in the MIP system on the imprinting process and final material performance. The potential drawbacks of using epitopes with protective groups, which can co-imprint with targeted functionality, are also discussed. KW - Functional monomers KW - Molecularly imprinted polymers KW - Phosphorylated peptides KW - Fluorescence KW - Core-shell particles PY - 2023 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-588089 DO - https://doi.org/10.1039/d3tb01474f SN - 2050-750X SP - 1 EP - 10 PB - Royal Society of Chemistry CY - Cambridge AN - OPUS4-58808 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Schnur, C. A1 - Goodarzi, P. A1 - Lugovtsova, Yevgeniya A1 - Bulling, Jannis A1 - Prager, Jens A1 - Tschöke, K. A1 - Moll, J. A1 - Schütze, A. A1 - Schneider, T. T1 - Towards interpretable machine learning for automated damage detection based on ultrasonic guided waves N2 - Data-driven analysis for damage assessment has a large potential in structural health monitoring (SHM) systems, where sensors are permanently attached to the structure, enabling continuous and frequent measurements. In this contribution, we propose a machine learning (ML) approach for automated damage detection, based on an ML toolbox for industrial condition monitoring. The toolbox combines multiple complementary algorithms for feature extraction and selection and automatically chooses the best combination of methods for the dataset at hand. Here, this toolbox is applied to a guided wave-based SHM dataset for varying temperatures and damage locations, which is freely available on the Open Guided Waves platform. A classification rate of 96.2% is achieved, demonstrating reliable and automated damage detection. Moreover, the ability of the ML model to identify a damaged structure at untrained damage locations and temperatures is demonstrated. KW - Composite structures KW - Structural health monitoring KW - Carbon fibre-reinforced plastic KW - Interpretable machine learning KW - Automotive industry PY - 2022 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-542060 DO - https://doi.org/10.3390/s22010406 SN - 1424-8220 VL - 22 IS - 1 SP - 1 EP - 19 PB - MDPI CY - Basel AN - OPUS4-54206 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Rütters, H. A1 - Fischer, S. A1 - Le, Quynh Hoa A1 - Bettge, Dirk A1 - Bäßler, Ralph A1 - Maßmann, J. A1 - Ostertag-Henning, C. A1 - Wolf, J. L. A1 - Pumpa, M. A1 - Lubenau, U. A1 - Knauer, S. A1 - Jaeger, P. A1 - Neumann, A. A1 - Svensson, K. A1 - Pöllmann, H. A1 - Lempp, C. A1 - Menezes, F. F. A1 - Hagemann, B. T1 - Towards defining reasonable minimum composition thresholds – Impacts of variable CO2 stream compositions on transport, injection and storage N2 - To set up recommendations on how to define “reasonable minimum composition thresholds” for CO2 streams to access CO2 pipeline networks, we investigated potential impacts of CO2 streams with different and temporally variable compositions and mass flow rates along the CCS chain. All investigations were based on a generic “CCS cluster scenario” in which CO2 streams captured from a spatial cluster of eleven emitters (seven fossil-fired power plants, two cement plants, one refinery and one steel mill) are collected in a regional pipeline network. The resulting CO2 stream (19.78 Mio t impure CO2 per year) is transported in a trunk line (onshore and offshore) and injected into five generic replicate storage structures (Buntsandstein saline aquifers) offshore. Experimental investigations and modeling of selected impacts revealed beneficial as well as adverse impacts of different impurities and their combinations. Overall, no fundamental technical obstacles for transporting, injecting and storing CO2 streams of the considered variable compositions and mass flow rates were observed. We recommend to define minimum composition thresholds for each specific CCS project through limiting i) the overall CO2 content, ii) maximum contents of relevant impurities or elements, iii) acceptable variability of concentrations of critical impurities, and defining impurity combinations to be avoided. KW - Impurities KW - CO2 quality KW - Pipeline network KW - Whole-chain CCS scenario KW - Recommendations PY - 2022 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-543004 DO - https://doi.org/10.1016/j.ijggc.2022.103589 SN - 1750-5836 VL - 114 SP - 1 EP - 14 PB - Elsevier CY - New York, NY AN - OPUS4-54300 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Christopher, I A1 - Michalchuk, Adam A1 - Pulham, C. A1 - Morrison, C. T1 - Towards Computational Screening for New Energetic Molecules: Calculation of Heat of Formation and Determination of Bond Strengths by Local Mode Analysis N2 - The reliable determination of gas-phase and solid-state heats of formation are important considerations in energetic materials research. Herein, the ability of PM7 to calculate the gas-phase heats of formation for CNHO-only and inorganic compounds has been critically evaluated, and for the former, comparisons drawn with isodesmic equations and Atom equivalence methods. Routes to obtain solid-state heats of formation for a range of singlecomponent molecular solids, salts, and co-crystals were also evaluated. Finally, local vibrational mode analysis has been used to calculate bond length/force constant curves for seven different chemical bonds occurring in CHNO-containing molecules, which allow for rapid identification of the weakest bond, opening up great potential to rationalise decomposition pathways. Both metrics are important tools in rationalising the design of new energetic materials through computational screening processes. KW - Energetic materials KW - Density functional theory PY - 2021 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-530371 DO - https://doi.org/10.3389/fchem.2021.726357 VL - 9 SP - 726357 AN - OPUS4-53037 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Wolf, J. A1 - Stawski, Tomasz A1 - Smales, Glen Jacob A1 - Thünemann, Andreas A1 - Emmerling, Franziska T1 - Towards automation of the polyol process for the synthesis of silver nanoparticles N2 - Metal nanoparticles have a substantial impact across diferent felds of science, such as photochemistry, energy conversion, and medicine. Among the commonly used nanoparticles, silver nanoparticles are of special interest due to their antibacterial properties and applications in sensing and catalysis. However, many of the methods used to synthesize silver nanoparticles often do not result in well-defned products, the main obstacles being high polydispersity or a lack of particle size tunability. We describe an automated approach to on-demand synthesis of adjustable particles with mean radii of 3 and 5 nm using the polyol route. The polyol process is a promising route for silver nanoparticles e.g., to be used as reference materials. We characterised the as-synthesized nanoparticles using small-angle X-ray scattering, dynamic light scattering and further methods, showing that automated synthesis can yield colloids with reproducible and tuneable properties. KW - Sillver KW - Nanoparticles KW - Automated synthesis KW - Chemputer KW - Scattering KW - SAXS PY - 2022 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-546803 DO - https://doi.org/10.1038/s41598-022-09774-w VL - 12 IS - 1 SP - 1 EP - 9 PB - Nature Springer AN - OPUS4-54680 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Vogel, Amelie A1 - Tentschert, Jutta A1 - Pieters, Raymond A1 - Bennet, Francesca A1 - Dirven, Hubert A1 - van den Berg, Annemijne A1 - Lenssen, Esther A1 - Rietdijk, Maartje A1 - Broßell, Dirk A1 - Haase, Andrea T1 - Towards a risk assessment framework for micro- and nanoplastic particles for human health N2 - Background Human exposure to micro- and nanoplastic particles (MNPs) is inevitable but human health risk assessment remains challenging for several reasons. MNPs are complex mixtures of particles derived from different polymer types, which may contain plenty of additives and/or contaminants. MNPs cover broad size distributions and often have irregular shapes and morphologies. Moreover, several of their properties change over time due to aging/ weathering. Case-by-case assessment of each MNP type does not seem feasible, more straightforward methodologies are needed. However, conceptual approaches for human health risk assessment are rare, reliable methods for exposure and hazard assessment are largely missing, and meaningful data is scarce. Methods Here we reviewed the state-of-the-art concerning risk assessment of chemicals with a specific focus on polymers as well as on (nano-)particles and fibres. For this purpose, we broadly screened relevant knowledge including guidance documents, standards, scientific publications, publicly available reports. We identified several suitable concepts such as: (i) polymers of low concern (PLC), (ii) poorly soluble low toxicity particles (PSLT) and (iii) fibre pathogenicity paradigm (FPP). We also aimed to identify promising methods, which may serve as a reasonable starting point for a test strategy. Results and conclusion Here, we propose a state-of-the-art modular risk assessment framework for MNPs, focusing primarily on inhalation as a key exposure route for humans that combines several integrated approaches to testing and assessment (IATAs). The framework starts with basic physicochemical characterisation (step 1), followed by assessing the potential for inhalative exposure (step 2) and includes several modules for toxicological assessment (step 3). We provide guidance on how to apply the framework and suggest suitable methods for characterization of physicochemical properties, exposure and hazard assessment. We put special emphasis on new approach methodologies (NAMs) and included grouping, where adequate. The framework has been improved in several iterative cycles by taking into account expert feedback and is currently being tested in several case studies. Overall, it can be regarded as an important step forward to tackle human health risk assessment. KW - Microplastics KW - Nanoplastics KW - Human health KW - Risk assessment KW - Integrated approaches to testing and assessment (IATAs) KW - Polymers of low concern (PLC) KW - Poorly soluble low toxicity particles (PSLT) PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-623790 DO - https://doi.org/10.1186/s12989-024-00602-9 SN - 1743-8977 VL - 21 IS - 1 SP - 1 EP - 21 PB - Springer Science and Business Media LLC AN - OPUS4-62379 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - John, Elisabeth A1 - Weise, Matthias A1 - Radnik, Jörg A1 - Stockmann, Jörg Manfred A1 - Lange, Thorid A1 - Sahre, Mario A1 - Hodoroaba, Vasile-Dan T1 - Towards a New Reference Material—Analytical Challenges in Examining High-Entropy Alloy Thin Films N2 - A new high-entropy alloy (HEA) consisting of titanium, chromium, manganese, iron, and nickel was deposited as a thin-film on silicon substrates using magnetron sputtering from a novel segmented target composed of metal stripes. This material was explored with the goal to create a new reference material for surface analysis and evaluation of complex composite materials. The film's morphology was initially characterized by scanning electron microscopy (SEM), followed by crystallographic analysis using X-ray diffraction (XRD) and selected area electron diffraction (SAED). The two-dimensional compositional homogeneity was assessed using a combination of scanning and transmission electron microscopy (TEM) with energy-dispersive spectroscopy (EDS), X-ray fluorescence (XRF), time-of-flight secondary ion mass spectrometry (ToF-SIMS), and X-ray photoelectron spectroscopy (XPS). The in-depth chemical composition was further analysed using ToF-SIMS and Auger electron spectroscopy (AES). Our findings demonstrate that it is possible to produce thin HEA films with a homogeneous in-depth composition from a segmented target. Notably, despite the fixed composition of the target, we were able to vary the HEA's composition by exploiting inhomogeneities within the magnetrons sputter plasma. Additionally, we successfully created HEA films with significant compositional gradients. T2 - ECASIA CY - Gothenburg, Sweden DA - 10.06.2024 KW - Reference material KW - High-entropy alloy KW - Thin-films PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-625777 DO - https://doi.org/10.1002/sia.7387 SN - 1096-9918 SP - 1 EP - 8 PB - Wiley AN - OPUS4-62577 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Grimmer, Christoph A1 - Richter, Matthias A1 - Neuhaus, T. A1 - Prinz, Carsten A1 - Strzelczyk, Rebecca Skadi A1 - Colakoglu, Irem A1 - Horn, Wolfgang T1 - Towards a multi-VOC emission reference material with temporally constant emission profile for QA/QC of materials emission testing procedures N2 - Emission reference materials (ERMs) are sought after to further control and improve indoor air quality. The impregnation of porous materials with volatile organic compounds (VOCs) is a promising approach to produce ERMs. Different VOCs were used to impregnate various porous materials (mainly zeolites, activated carbons and a metal organic framework). The influence of different methodological parameters and material properties were studied to optimize the impregnation procedure and to find the best material/VOC combination. The impregnation procedure remains quite irreproducible, nevertheless, very good ERM candidates were identified. Two materials (zeolite 4 and AC 1 impregnated with n-hexadecane) showed a very stable emission over 14 days (<10 % change). Another material (AC 1 impregnated with toluene) showed a declining emission profile but with a very good in-batch reproducibility and a storage stability of up to 12 months. KW - Emission reference material KW - Porous materials KW - Indoor air quality KW - Emission test chamber KW - CO2 assisted impregnation KW - EN 16516 PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-612238 DO - https://doi.org/10.1016/j.chemosphere.2024.143437 SN - 1879-1298 VL - 366 SP - 1 EP - 8 PB - Elsevier AN - OPUS4-61223 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Zerbst, Uwe A1 - Madia, Mauro A1 - Bruno, Giovanni A1 - Hilgenberg, Kai T1 - Towards a Methodology for Component Design of Metallic AM Parts Subjected to Cyclic Loading N2 - The safe fatigue design of metallic components fabricated by additive manufacturing (AM) is still a largely unsolved problem. This is primarily due to (a) a significant inhomogeneity of the material properties across the component; (b) defects such as porosity and lack of fusion as well as pronounced surface roughness of the asuilt components; and (c) residual stresses, which are very often present in the as‐built parts and need to be removed by post‐fabrication treatments. Such morphological and microstructural features are very different than in conventionally manufactured parts and play a much bigger role in determining the fatigue life. The above problems require specific solutions with respect to the identification of the critical (failure) sites in AM fabricated components. Moreover, the generation of representative test specimens characterized by similar temperature cycles needs to be guaranteed if one wants to reproducibly identify the critical sites and establish fatigue assessment methods taking into account the effect of defects on crack initiation and early propagation. The latter requires fracture mechanics‐based approaches which, unlike common methodologies, cover the specific characteristics of so‐called short fatigue cracks. This paper provides a discussion of all these aspects with special focus on components manufactured by laser powder bed fusion (L‐PBF). It shows how to adapt existing solutions, identifies fields where there are still gaps, and discusses proposals for potential improvement of the damage tolerance design of L‐PBF components KW - L‐PBF KW - Fatigue KW - Fracture KW - Defects PY - 2021 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-525822 DO - https://doi.org/10.3390/met11050709 VL - 11 IS - 5 SP - 709 PB - MDPI CY - Basel AN - OPUS4-52582 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Bennet, Francesca A1 - Burr, L. A1 - Schmid, D. A1 - Hodoroaba, Vasile-Dan T1 - Towards a method for quantitative evaluation of nanoparticle from suspensions via microarray printing and SEM analysis N2 - As part of the development of a library of accurate and efficient methods for measurement of nanoparticle properties, we develop and optimize a method for the efficient analysis of nanoparticle size distribution from suspensions via microprinting and digital analysis of electron microscopy (SEM and TEM) images, with the ultimate aim of automated quantitative concentration analysis (calculated from drop volume). A series of different nanoparticle suspensions (gold, latex, and SiO2 in varying sizes and concentrations) were printed onto TEM grids in a 4 x 4 array in the concentration range 7x10^8 to 1x10^11 nanoparticles/mL and imaged with SEM. Concentrations and printing conditions (temperature, relative humidity) were varied in order to minimize the coffee-ring effect. KW - Nanoparticles KW - Particle size distribution KW - Electron microscopy KW - Microarray printing KW - Sample preparation KW - Nanoparticle concentration PY - 2021 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-528455 DO - https://doi.org/10.1088/1742-6596/1953/1/012002 VL - 1953 SP - 012002 PB - IOP Publishing AN - OPUS4-52845 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Zocca, Andrea A1 - Günster, Jens T1 - Towards a debinding-free additive manufacturing of ceramics: A development perspective of water-based LSD and LIS technologies N2 - Ceramic additive manufacturing (AM) requires a complex process chain with various post-processing steps that require expensive machines and special expertise. The key to further market penetration is AM that makes it possible to integrate into an already established ceramic process chain. Most successful AM technologies for ceramics are, however, based on processes that initially have been developed for polymeric materials. For ceramics AM, polymers or precursors are loaded with ceramic particles. This strategy facilitates the entry into AM, however the introduction of organic additives into the ceramic process chain represents a considerable technological challenge to ultimately obtain a ceramic component after additive shaping. In the present communication, two technologies based on ceramic suspensions will be introduced, the “layerwise slurry deposition” (LSD) and “laser induced slip casting” (LIS) technology. Both technologies take advantage of the high packing densities reached by conventional slip casting and moreover enable the processing of fines, even nanoparticles. KW - Additive Manufacturing KW - Ceramic KW - Water-based KW - Debinding KW - Slurry PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-605531 DO - https://doi.org/10.1016/j.oceram.2024.100632 SN - 2666-5395 VL - 19 SP - 1 EP - 13 PB - Elsevier B.V. AN - OPUS4-60553 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Hülagü, Deniz A1 - Tobias, Charlie A1 - Dao, Radek A1 - Komarov, Pavel A1 - Rurack, Knut A1 - Hodoroaba, Vasile-Dan T1 - Towards 3D determination of the surface roughness of core–shell microparticles as a routine quality control procedure by scanning electron microscopy N2 - AbstractRecently, we have developed an algorithm to quantitatively evaluate the roughness of spherical microparticles using scanning electron microscopy (SEM) images. The algorithm calculates the root-mean-squared profile roughness (RMS-RQ) of a single particle by analyzing the particle’s boundary. The information extracted from a single SEM image yields however only two-dimensional (2D) profile roughness data from the horizontal plane of a particle. The present study offers a practical procedure and the necessary software tools to gain quasi three-dimensional (3D) information from 2D particle contours recorded at different particle inclinations by tilting the sample (stage). This new approach was tested on a set of polystyrene core-iron oxide shell-silica shell particles as few micrometer-sized beads with different (tailored) surface roughness, providing the proof of principle that validates the applicability of the proposed method. SEM images of these particles were analyzed by the latest version of the developed algorithm, which allows to determine the analysis of particles in terms of roughness both within a batch and across the batches as a routine quality control procedure. A separate set of particles has been analyzed by atomic force microscopy (AFM) as a powerful complementary surface analysis technique integrated into SEM, and the roughness results have been compared. KW - Core–shell particles KW - Image analysis KW - Roughness KW - Scanning electron microscopy KW - Atomic force microscopy KW - Tilting KW - Batch analysis PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-607590 DO - https://doi.org/10.1038/s41598-024-68797-7 SN - 2045-2322 VL - 14 IS - 1 SP - 1 EP - 13 PB - Springer Science and Business Media LLC AN - OPUS4-60759 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Caianiello, Carlo A1 - Tichter, Tim A1 - Arenas, Luis F. A1 - Wilhelm, René T1 - Toward Symmetric Organic Aqueous Flow Batteries: Triarylamine‐Based Bipolar Molecules and Their Characterization via an Extended Koutecký–Levich Analysis N2 - Symmetric organic flow batteries (SOFBs) can potentially address membrane crossover problems by employing bipolar redox‐active organic molecules (BROMs). Herein, a triarylamine (TAA) skeleton was chosen as a posolyte moiety for a new class of bipolar molecules for pH‐neutral aqueous flow batteries (FBs). Pyridinium and viologen derivatives were tethered to the posolyte moiety, and the new compounds were characterized. Cyclic voltammetry revealed that only viologen with a highly hydrophilic substituent, connected to the TAA moiety via a Zincke reaction, could be reversibly reduced. Varying the supporting electrolyte concentration on the selected derivative revealed water solubility as a challenge for further development. The selected derivative, MeO‐TPA‐Vi‐DMAE, was subjected to hydrodynamic voltammetry, and a modified Koutecký–Levich analysis was developed to investigate the observed potential‐dependent currents at the hydrodynamically dominated region, which are often seen with redox‐active organic molecules. This model discarded a purely Ohmic effect, showing a useful Levich slope at a certain overpotential before the onset of a secondary reaction. TAA‐based BROMs hold promise for pH‐neutral aqueous SOFBs, and the results will guide the design of new derivatives. The three‐term Koutecký–Levich relation here introduced will be useful not only to develop BROM‐based FBs but will most likely appeal to a much broader audience. KW - Redox Flow Batteries KW - Koutecký-Levich Analysis KW - Rotating Disc Electrode KW - Redox-active Bipolar Molecules KW - Electrode Kinetics PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-631476 DO - https://doi.org/10.1002/chem.202500815 SN - 1521-3765 SP - 1 EP - 15 PB - Wiley VHC-Verlag AN - OPUS4-63147 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Meng, Xiangmeng A1 - Bachmann, Marcel A1 - Yang, Fan A1 - Rethmeier, Michael T1 - Toward prediction and insight of porosity formation in laser welding: A physics-informed deep learning framework N2 - The laser welding process is an important manufacturing technology for metallic materials. However, its application is often hindered by the occurrence of porosity defects. By far, an accurate prediction of the porosity defects and an insight into its formation mechanism are still challenging due to the highly nonlinear physics involved. In this paper, we propose a physics-informed deep learning (PIDL) framework by utilizing mechanistic modeling and experimental data to predict the porosity level during laser beam welding of aluminum alloys. With a proper selection of the physical variables (features) concerning the solidification, liquid metal flow, keyhole stability, and weld pool geometry, the PIDL model shows great superiority in predicting the porosity ratio, with a reduction of mean square error by 41 %, in comparison with the conventional DL model trained with welding parameters. Furthermore, the selected variables are fused into dimensionless features with explicit physical meanings to improve the interpretability and extendibility of the PIDL model. Based on a well-trained PIDL model, the hierarchical importance of the physical variables/procedures on the porosity formation is for the first time revealed with the help of the Shapley Additive Explanations analysis. The keyhole ratio is identified as the most influential factor in the porosity formation, followed by the downward flow-driven drag force, which offers a valuable guideline for process optimization and porosity minimization. KW - Laser beam welding KW - Physics-informed deep learning KW - Porosity prediction KW - Feature fusion KW - Hierarchical importance PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-624708 DO - https://doi.org/10.1016/j.actamat.2025.120740 VL - 286 SP - 1 EP - 13 PB - Elsevier B.V. AN - OPUS4-62470 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Krahl, T. A1 - Beer, F. A1 - Relling, A. A1 - Gawlitza, Kornelia A1 - Rurack, Knut A1 - Kemnitz, E. T1 - Toward Luminescent Composites by Phase Transfer of SrF2 :Eu3+ Nanoparticles Capped with Hydrophobic Antenna Ligands N2 - Transparent dispersions of hydrophobic SrF2 :Eu3+ nanoparticles in cyclohexane with up to 20% europium were obtained by fluorolytic sol-gel synthesis followed by Phase transfer into cyclohexane through capping with sodium dodecylbenzenesulfonate (SDBS). The particles were characterized by TEM, XRD and DLS as spherical objects with a diameter between 6 and 11 nm in dry state. 1H-13CP MAS NMR experiments revealed the binding of the anionic sulfonate head group to the particle surface. The particles show bright red luminescence upon excitation of the aromatic capping agents, acting as antennas for an Energy transfer from the benzenesulfonate unit to the Eu3+ centers in the particles. This synthesis method overcomes the current obstacle of the fluorolytic sol-gel synthesis that transparent dispersions can be obtained directly only in hydrophilic solvents. To demonstrate the potential of such hydrophobized alkaline-earth fluoride particles, transparent luminescent organic-inorganic composites with 10% SrF2 :Eu3+ embedded into polyTEGDMA, polyBMA, poly-BDDMA and polyD3MA, respectively, were prepared, endowing the polymers with the luminescence features of the nanoparticles. KW - Nanoparticles KW - Fluorides KW - Sol-gel process KW - Organic-inorganic hybrid composites PY - 2020 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-508668 DO - https://doi.org/10.1002/cnma.202000058 SP - 1 EP - 11 PB - Wiley AN - OPUS4-50866 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Climent Terol, Estela A1 - Wan, Wei A1 - Rurack, Knut T1 - Toward Label-Free Optical Multiplexing of Analytes in Indicator Release Lateral Flow Assays via Detection Zones Containing Tailored Capture Materials N2 - The use of macromolecules and materials immobilized in the detection zone of test strips for indicator capture and focusing in label-free lateral flow assays (LFAs) is described, with emphasis on its future use in low number multiplexing. Several materials such as polyelectrolytes, functionalized mesoporous silica micro- and nanoparticles, chemically modified cellulose or glass fibre (GF) membranes and molecularly imprinted polymer gels coated onto membranes were studied in model assays, before the most promising materials were combined with antibody-gated indicator delivering (gAID) sensor materials. Cellulose, nitrocellulose and GF membranes were used as supports and highly fluorescent dyes of different charge states as model indicators. Combination of the best performing capture materials with gAID systems made it possible to distinctly increase the sensitivity and reduce the measurement uncertainty in the LFA testing of pentaerythritol tetranitrate (PETN) in aqueous samples. In addition, dual-plexing of PETN and 2,4,6-trinitrotoluene (TNT) was realized on a single test strip containing two dedicated capture zones. KW - Rapid tests KW - Vor-Ort-Analytik KW - Multiplexing KW - Teststreifen KW - Molecularly imprinted polymers PY - 2022 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-557873 DO - https://doi.org/10.1002/anse.202100062 VL - 2 IS - 4 SP - 1 EP - 10 PB - Wiley-VCH CY - Weinheim AN - OPUS4-55787 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Karapanagiotis, Christos A1 - Schukar, Marcus A1 - Breithaupt, Mathias A1 - Hicke, Konstantin T1 - Toward a Digital Twin of Hydrogen Pressure Vessels Enabled by Distributed Fiber Optic Sensors N2 - We present a digital replica of a hydrogen pressure vessel enabled by distributed fiber optic sensors (DFOS). This digital replica dynamically displays and updates the vessel’s structural condition by calculating strain residuals defined as the difference between the measured DFOS strain and the expected strain based on pressure data. As an example, we show the ability of the DFOS to detect and localize damage caused by drilling six holes into the vessel’s body. This digital replica represents a foundational step toward a fully integrated digital twin for predictive maintenance and remaining lifetime prognosis. T2 - Sensor and Measurement Science International (SMSI) 2025 CY - Nuremberg, Germany DA - 06.05.2025 KW - fiber optic sensors KW - digital twin KW - structural health monitoring KW - hydrogen KW - machine learning PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-633885 UR - https://www.ama-science.org/proceedings/details/5962 SN - 978-3-910600-06-5 DO - https://doi.org/10.5162/SMSI2025/C6.1 SP - 165 EP - 166 PB - AMA Service GmbH CY - Wunstorf AN - OPUS4-63388 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Beygi Nasrabadi, Hossein A1 - Hanke, T. A1 - Weber, M. A1 - Eisenbart, M. A1 - Bauer, F. A1 - Meissner, R. A1 - Dziwis, G. A1 - Tikana, L. A1 - Chen, Yue A1 - Skrotzki, Birgit T1 - Toward a digital materials mechanical testing lab N2 - To accelerate the growth of Industry 4.0 technologies, the digitalization of mechanical testing laboratories as one of the main data-driven units of materials processing industries is introduced in this paper. The digital lab infrastructure consists of highly detailed and standard-compliant materials testing knowledge graphs for a wide range of mechanical testing processes, as well as some tools that enable the efficient ontology development and conversion of heterogeneous materials’ mechanical testing data to the machine-readable data of uniform and standardized structures. As a basis for designing such a digital lab, the mechanical testing ontology (MTO) was developed based on the ISO 23718 and ISO/IEC 21838-2 standards for the semantic representation of the mechanical testing experiments, quantities, artifacts, and report data. The trial digitalization of materials mechanical testing lab was successfully performed by utilizing the developed tools and knowledge graph of processes for converting the various experimental test data of heterogeneous structures, languages, and formats to standardized Resource Description Framework (RDF) data formats. The concepts of data storage and data sharing in data spaces were also introduced and SPARQL queries were utilized to evaluate how the introduced approach can result in the data retrieval and response to the competency questions. The proposed digital materials mechanical testing lab approach allows the industries to access lots of trustworthy and traceable mechanical testing data of other academic and industrial organizations, and subsequently organize various data-driven research for their faster and cheaper product development leading to a higher performance of products in engineering and ecological aspects. KW - General Engineering KW - General Computer Science PY - 2023 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-582698 DO - https://doi.org/10.1016/j.compind.2023.104016 SN - 0166-3615 VL - 153 SP - 1 EP - 15 PB - Elsevier B.V. AN - OPUS4-58269 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kruschwitz, Sabine A1 - Halisch, M. A1 - Dlugosch, R. A1 - Prinz, Carsten T1 - Toward a better understanding of low-frequency electrical relaxation - An enhanced pore space characterization N2 - Relaxation phenomena observed in the electrical low-frequency range (approximately 1 mHz-10 kHz) of natural porous media like sandstones is often assumed to be directly related to the dominant (modal) pore throat sizes measured, for instance, with mercury intrusion porosimetry. Attempts to establish a universally valid relationship between pore size and peak Spectral Induced Polarization (SIP) relaxation time have failed, considering sandstones from very different origins and featuring great variations in textural and chemical compositions as well as in geometrical pore space properties. In addition working with characteristic relaxation times determined in Cole-Cole or Debye decomposition fits to build the relationship have not been successful. In particular, samples with narrow pore throats are often characterized by long SIP relaxation times corresponding to long “characteristic length scales” in these media, assuming that the diffusion coefficients along the electrical double layer were constant. Based on these observations, three different types of SIP relaxation can be distinguished. We present a new way of assessing complex pore spaces of very different sandstones in a multi-methodical approach to combine the benefits of mercury intrusion porosimetry, micro-computed tomography, and nuclear magnetic resonance. In this way, we achieve much deeper insight into the pore space due to the different resolutions and sensitivities of the applied methods to both pore constrictions (throats) and wide pores (pore bodies). We experimentally quantify pore aspect ratios and volume distributions within the two pore regions. We clearly observe systematic differences between three SIP relaxation types identified previously and can attribute the SIP peak relaxation times to measured characteristic length scales within our materials. We highlight selected results for a total of nine sandstones. It seems that SIP relaxation behavior depends on the size difference of the narrow pore throats to the wide pore bodies, which increases from SIP Type 1 to Type 3. KW - µ-CT KW - Spectral induced polarization KW - Nuclear magnetic resonance KW - Pore space PY - 2020 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-509763 DO - https://doi.org/10.1190/GEO2019-0074.1 SN - 0016-8033 VL - 85 IS - 4 SP - MR257 EP - MR270 PB - Society of Exploration Geophysicists AN - OPUS4-50976 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Lecompagnon, Julien A1 - Rooch, Ludwig A1 - Hassenstein, Christian A1 - Ziegler, Mathias ED - Sakagami, T. ED - Inoue, H. T1 - Total Focusing in the Virtual Wave Domain: 3D Defect Reconstruction Using Spatially Structured Laser Heating N2 - Classical active thermographic testing of industrial goods has mostly been limited to generating 2D defect maps. While for surface or near-surface defect detection, this is a desired result, for deeply buried defects, a 3D reconstruction of the defect geometry is coveted. This general trend can also be well observed in widely used NDT methods (radiography, ultrasonic testing), where the progression from 2D to 3D reconstruction methods has already made profound progress (CT, UT phased array transducers). Achieving a fully 3D defect reconstruction in active thermographic testing suffers from the diffusive nature of thermal processes. One possible solution to deal with thermal diffusion is the application of the virtual-wave concept, which, by solving an inverse problem, allows the diffusiveness to be extracted from the thermographic data in the post-processing stage. What is left follows propagating-wave physics, enabling the usage of well-known algorithms from ultrasonic testing. In this work, we present our progress in the 3D reconstruction of deeply buried defects using spatially structured laser heating in conjunction with applying the well-known total focusing method (TFM) in the virtual-wave domain. T2 - 18th International Workshop on Advanced Infrared Technology and Applications (AITA 2025) CY - Kobe, Japan DA - 15.09.2025 KW - Non-destructive testing KW - Virtual wave concept KW - Laser thermography KW - Thermal thomography PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-641463 DO - https://doi.org/10.3390/proceedings2025129054 VL - 129 IS - 1 SP - 1 EP - 5 PB - MDPI CY - Basel AN - OPUS4-64146 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Van Tran, K. A1 - Woracek, R. A1 - Kardjilov, N. A1 - Markötter, Henning A1 - Abou-Ras, D. A1 - Puplampu, S. A1 - Förster, C. A1 - Penumadu, D. A1 - Dahlberg, C. F. O. A1 - Banhart, J. A1 - Manke, I. T1 - Torsion of a rectangular bar: Complex phase distribution in 304L steel revealed by neutron tomography N2 - Metastable austenitic stainless steel (304L) samples with a rectangular cross-section were plastically deformed in torsion during which they experienced multiaxial stresses that led to a complex martensitic phase distribution owing to the transformation induced plasticity effect. A three-dimensional characterization of the phase distributions in these cm-sized samples was carried out by wavelength-selective neutron tomography. It was found that quantitatively correct results are obtained as long as the samples do not exhibit any considerable preferential grain orientation. Optical microscopy, electron backscatter diffraction, and finite element modeling were used to verify and explain the results obtained by neutron tomography. Altogether, neutron tomography was shown to extend the range of microstructure characterization methods towards the meso- and macroscale. KW - Neutron tomography KW - Phase distribution KW - Rectangular cross-section KW - Torsion KW - Geometrical effect PY - 2022 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-561649 DO - https://doi.org/10.1016/j.matdes.2022.111037 SN - 0264-1275 VL - 222 SP - 111037 PB - Elsevier Ltd. AN - OPUS4-56164 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Tran, K. V. A1 - Woracek, R. A1 - Kardjilov, N. A1 - Markötter, Henning A1 - Abou-Ras, D. A1 - Puplampu, S. A1 - Förster, C. A1 - Penumadu, D. A1 - Dahlberg, C. F. O. A1 - Banhart, J. A1 - Manke, I. T1 - Torsion of a rectangular bar: Complex phase distribution in 304L steel revealed by neutron tomography N2 - Metastable austenitic stainless steel (304L) samples with a rectangular cross-section were plastically deformed in torsion during which they experienced multiaxial stresses that led to a complex martensitic phase distribution owing to the transformation induced plasticity effect. A three-dimensional characterization of the phase distributions in these cm-sized samples was carried out by wavelength-selective neutron tomography. It was found that quantitatively correct results are obtained as long as the samples do not exhibit any considerable preferential grain orientation. Optical microscopy, electron backscatter diffraction, and finite element modeling were used to verify and explain the results obtained by neutron tomography. Altogether, neutron tomography was shown to extend the range of microstructure characterization methods towards the meso- and macroscale. KW - Neutron tomography KW - Phase distribution KW - Rectangular cross-section KW - Torsion KW - Geometrical effect PY - 2022 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-569101 DO - https://doi.org/10.1016/j.matdes.2022.111037 VL - 222 SP - 1 EP - 13 PB - Elsevier Ltd. AN - OPUS4-56910 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Witte, Julien A1 - Schröpfer, Dirk A1 - Hamacher, M. A1 - Michels, H. A1 - Hamm, C. A1 - Appelt, M. A1 - Börner, Andreas A1 - Kannengießer, Thomas T1 - Tool development for hybrid finishing milling of iron aluminides N2 - The importance of high-temperature materials made of iron aluminides (FeAl) has been increasing in light weight applications, e.g., airplane turbines, due to the high material’s specific strength. However, the highly economic production by means of permanent mold casting involves special microstructures for Fe26Al4Mo0.5Ti1B alloy components leading to difficult machinability for subsequent finishing milling and low surface qualities. Major effects of tool and machining parameter variation incorporating ultrasonic assistance on the milling process and surface integrity are shown. Loads for tool and component surface are significantly adjustable to enable an economic process chain regarding the surface integrity of safety-relevant components. KW - Ultrasonic-assisted milling KW - Iron aluminide KW - Surface integrity KW - Tool wear PY - 2022 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-566294 DO - https://doi.org/10.1016/j.procir.2022.03.123 SN - 2212-8271 VL - 108 SP - 793 EP - 798 PB - Elsevier B.V. AN - OPUS4-56629 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Dudziak, Mateusz A1 - Dural, Esra A1 - Dey, R. A1 - Ullrich, M. S. A1 - Huth, Christian A1 - Thomson, C. A1 - Schartel, Bernhard T1 - Together We Can: Synergistic Flame Retardancy by Melamine Polyphosphate and Phosphorylated Microalgae in Polylactide Biocomposites N2 - A strategy for enhancing the sustainable flame retardancy of polylactide (PLA) composites by partially replacing melamine polyphosphate (MPP), a commercial flame retardant proposed for PLA, with wastewater polyphosphate-enriched microalgae (P-Algae) has been explored. The incorporation of P-Algae at a 1:1 ratio with MPP leads to a notable synergistic effect, surpassing the expected additive behavior of the individual components. Comprehensive characterization encompassing thermogravimetric analysis coupled with FTIR, pyrolysis combustion flow calorimeter (PCFC), cone calorimeter, oxygen index (LOI), UL-94 tests, and rheological measurements—demonstrates that the presence of this biomaterial can significantly enhance flame retardant performance. Replacing 50% of MPP with P-Algae in PLA resulted in a 17% reduction in peak heat release rate (pHRR) and maintained a V-0 rating in UL-94 testing. The use of P-Algae does not compromise the flame retardancy of PLA but rather contributes positively, offering a promising path toward more sustainable flame-retardant systems. By leveraging naturally derived biomass, this approach aligns with the growing demand for novel eco-friendly technologies in polymer engineering. Insights into an innovative renewable additive as a functional and effective component in flame-retardant biocomposites have been achieved. KW - Flame retardancy KW - Melamine polyphosphate KW - Phosphorus- enriched microalgae KW - Polylactide PLA KW - Synergism PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-640539 DO - https://doi.org/10.1002/pat.70350 SN - 1099-1581 SN - 1042-7147 VL - 36 IS - 9 SP - e70350 PB - John Wiley & Sons Ltd. AN - OPUS4-64053 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Scharek, Vera M. A1 - Pfeifer, Jens A1 - Vogl, Jochen A1 - Traub, Heike A1 - Meermann, Björn T1 - Tin fractionation analysis in sediment samples via on-line ID ETV/ICP-MS N2 - We report a quantification approach for directly determining total tin and tin-based pollutants/species in sediments via electrothermal vaporization/inductively coupled plasma-mass spectrometry (ETV/ICP-MS) utilizing an on-line isotope dilution mass spectrometry (IDMS) approach. The method was developed and validated using an estuarine sediment reference material (BCR-277R), yielding a recovery of 106%. A relative standard deviation (RSD) of 14%, comparable to published data using a similar method, was obtained. A limit of quantification (LOQ) was estimated at 0.008 mg Sn kg−1 and sufficient for quantifying the total tin mass fraction of surface sediments along the tidal River Elbe course. Hereby, a decrease towards the river mouth, presumably due to dilution effects by less polluted marine sediment, was observed. Besides total tin, monitoring of organotin compounds (OTCs)/species is of interest in sediments due to their toxic effects on aquatic life. The method’s capability was extended by separating an OTC fraction in a sediment certified reference material (CRM) through the ETV temperature program. While spiking experiments with OTC standards confirmed the assignment, only a small fraction of the total certified OTC amount (3%), likely due to matrix effects, was recovered. However, applying the method to real-world samples, OTCs were detectable along the River Elbe course. By this, we demonstrated the potential of our method as a complementary fast-screening approach to species-specific analysis procedures. KW - ETV KW - Sn-Speciation KW - Sediment PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-640137 DO - https://doi.org/10.1007/s00216-025-06064-y SN - 1618-2642 SP - 1 EP - 10 PB - Springer Science and Business Media LLC AN - OPUS4-64013 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Griesche, Axel A1 - Pfretzschner, B. A1 - Taparli, Ugur Alp A1 - Kardjilov, N. T1 - Time-Resolved Neutron Bragg-Edge Imaging: A Case Study by Observing Martensitic Phase Formation in Low Temperature Transformation (LTT) Steel during GTAW N2 - Polychromatic and wavelength-selective neutron transmission radiography were applied during bead-on-plate welding on 5 mm thick sheets on the face side of martensitic low transformation temperature (LTT) steel plates using gas tungsten arc welding (GTAW). The in situ visualization of austenitization upon welding and subsequent α’-martensite formation during cooling could be achieved with a temporal resolution of 2 s for monochromatic imaging using a single neutron wavelength and of 0.5 s for polychromatic imaging using the full spectrum of the beam (white beam). The spatial resolution achieved in the experiments was approximately 200 µm. The transmitted monochromatic neutron beam intensity at a wavelength of λ = 0.395 nm was significantly reduced during cooling below the martensitic start temperature Ms since the emerging martensitic phase has a ~10% higher attenuation coefficient than the austenitic phase. Neutron imaging was significantly influenced by coherent neutron scattering caused by the thermal motion of the crystal lattice (Debye–Waller factor), resulting in a reduction in the neutron transmission by approx. 15% for monochromatic and by approx. 4% for polychromatic imaging. KW - Austenite-to-martensite transformation KW - Neutron radiography KW - Bragg-edge imaging KW - Gas tungsten arc welding (GTAW) KW - Debye–Waller factor KW - Low transformation temperature (LTT) steel PY - 2021 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-538016 DO - https://doi.org/10.3390/app112210886 VL - 11 IS - 22 SP - 10886 PB - MDPI CY - Basel AN - OPUS4-53801 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Griesche, Axel A1 - Pfretzschner, Beate A1 - Taparli, Ugur Alp A1 - Kardjilov, N. T1 - Time-Resolved Neutron Bragg-Edge Imaging: A Case Study by Observing Martensitic Phase Formation in Low Temperature Transformation (LTT) Steel during GTAW N2 - Polychromatic and wavelength-selective neutron transmission radiography were applied during bead-on-plate welding on 5 mm thick sheets on the face side of martensitic low transformation temperature (LTT) steel plates using gas tungsten arc welding (GTAW). The in situ visualization of austenitization upon welding and subsequent α’-martensite formation during cooling could be achieved with a temporal resolution of 2 s for monochromatic imaging using a single neutron wavelength and of 0.5 s for polychromatic imaging using the full spectrum of the beam (white beam). The spatial resolution achieved in the experiments was approximately 200 µm. The transmitted monochromatic neutron beam intensity at a wavelength of λ = 0.395 nm was significantly reduced during cooling below the martensitic start temperature M s since the emerging martensitic phase has a ~10% higher attenuation coefficient than the austenitic phase. Neutron imaging was significantly influenced by coherent neutron scattering caused by the thermal motion of the crystal lattice (Debye–Waller factor), resulting in a reduction in the neutron transmission by approx. 15% for monochromatic and by approx. 4% for polychromatic imaging. KW - Neutron radiography KW - Debye–Waller factor KW - Austenite-to-martensite transformation KW - Low transformation temperature (LTT) steel KW - Bragg-edge imaging KW - Gas tungsten arc welding (GTAW) PY - 2021 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-559077 DO - https://doi.org/10.3390/app112210886 VL - 11 IS - 22 PB - MDPI AN - OPUS4-55907 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kabelitz, Anke A1 - de Oliveira Guilherme Buzanich, Ana A1 - Joester, Maike A1 - Reinholz, Uwe A1 - Radtke, Martin A1 - Bienert, Ralf A1 - Schulz, K. A1 - Schmack, R. A1 - Kraehnert, R. A1 - Emmerling, Franziska T1 - Time-resolved in situ studies on the formation mechanism of iron oxide nanoparticles using combined fast-XANES and SAXS N2 - The reaction of iron chlorides with an alkaline reagent is one of the most prominent methods for the synthesis of iron oxide nanoparticles. We studied the particle formation mechanism using triethanolamine as reactant and stabilizing agent. In situ fast-X-ray absorption near edge spectroscopy and small-angle X-ray scattering provide information on the oxidation state and the structural information at the same time. In situ data were complemented by ex situ transmission electron microscopy, wide-angle X-ray scattering and Raman analysis of the formed nanoparticles. The formation of maghemite nanoparticles (γ-Fe2O3) from ferric and ferrous chloride was investigated. Prior to the formation of these nanoparticles, the formation and conversion of intermediate phases (akaganeite, iron(II, III) hydroxides) was observed which undergoes a morphological and structural collapse. The thus formed small magnetite nanoparticles (Fe3O4) grow further and convert to maghemite with increasing reaction time. KW - oxidation state KW - structural information KW - maghemite PY - 2015 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-351376 DO - https://doi.org/10.1039/C5CE01585E SN - 1466-8033 VL - 17 IS - 44 SP - 8463 EP - 8470 CY - London, UK AN - OPUS4-35137 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Karapanagiotis, Christos A1 - Wosniok, Aleksander A1 - Hicke, Konstantin A1 - Krebber, Katerina T1 - Time-Efficient Convolutional Neural Network-Assisted Brillouin Optical Frequency Domain Analysis N2 - To our knowledge, this is the first report on a machine-learning-assisted Brillouin optical frequency domain analysis (BOFDA) for time-efficient temperature measurements. We propose a convolutional neural network (CNN)-based signal post-processing method that, compared to the conventional Lorentzian curve fitting approach, facilitates temperature extraction. Due to its robustness against noise, it can enhance the performance of the system. The CNN-assisted BOFDA is expected to shorten the measurement time by more than nine times and open the way for applications, where faster monitoring is essential. KW - Fiber-optic sensors KW - Machine learning KW - Temperature and strain monitoring KW - Brillouin distributed sensing PY - 2021 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-524631 DO - https://doi.org/10.3390/s21082724 VL - 21 IS - 8 SP - 2724 PB - MDPI AN - OPUS4-52463 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Örnek, C. A1 - Léonard, Fabien A1 - McDonald, S. A1 - Prajapati, A A1 - Withers, P. J. A1 - Engelberg, D. T1 - Time-dependent in situ measurement of atmospheric corrosion rates of duplex stainless steel wires N2 - Corrosion rates of strained grade UNS S32202 (2202) and UNS S32205 (2205) duplex stainless steel wires have been measured, in situ, using time-lapse X-ray computed tomography. Exposures to chloride-containing (MgCl2) atmospheric environments at 50 °C (12–15 M Cl− and pH ~5) with different mechanical elastic and elastic/plastic loads were carried out over a period of 21 months. The corrosion rates for grade 2202 increased over time, showing selective dissolution with shallow corrosion sites, coalescing along the surface of the wire. Corrosion rates of grade 2205 decreased over time, showing both selective and pitting corrosion with more localised attack, growing preferentially in depth. The nucleation of stress corrosion cracking was observed in both wires. KW - X-ray computed tomography KW - Time-lapse X-ray computed tomography PY - 2018 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-444153 UR - https://www.nature.com/articles/s41529-018-0030-9 DO - https://doi.org/10.1038/s41529-018-0030-9 SN - 2397-2106 VL - 2 SP - Article 10, 1 EP - 15 PB - Nature CY - London AN - OPUS4-44415 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Peters, Stefan A1 - Kunkel, Benny A1 - Cakir, Cafer Tufan A1 - Kabelitz, Anke A1 - Witte, Steffen A1 - Bernstein, Thomas A1 - Bartling, Stephan A1 - Radtke, Martin A1 - Emmerling, Franziska A1 - Abdel-Mageed, Ali Mohamed A1 - Wohlrab, Sebastian A1 - de Oliveira Guilherme Buzanich, Ana T1 - Time-, space- and energy-resolved in situ characterization of catalysts by X-ray absorption spectroscopy N2 - A novel setup for dispersive X-ray absorption spectroscopy (XAS) with simultaneous resolution of space, time and energy for in situ characterization of solid materials is demonstrated. KW - Dispersive XAS KW - Catalysis KW - In situ KW - Structure analysis PY - 2023 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-584924 DO - https://doi.org/10.1039/d3cc03277a SN - 1359-7345 SP - 1 EP - 4 PB - Royal Society of Chemistry (RSC) AN - OPUS4-58492 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - de Oliveira Guilherme Buzanich, Ana A1 - Radtke, Martin A1 - Reinholz, Uwe A1 - Riesemeier, Heinrich A1 - Emmerling, Franziska T1 - Time- & spatial-resolved X-ray absorption fine structure (XAFS) spectroscopy in a single-shot – new analytical possibilities for in situ material characterization N2 - A new concept that comprises both time- and lateral-resolved X-ray absorption fine-structure information simultaneously in a single shot is presented. This uncomplicated set-up was tested at the BAMline at BESSY-II (Berlin, Germany). The primary broadband beam was generated by a double multilayer monochromator. The transmitted beam through the sample is diffracted by a convexly bent Si (111) crystal, producing a divergent beam. This, in turn, is collected by either an energy-sensitive area detector, the so-called color X-ray camera, or by an area-sensitive detector based on a CCD camera, in θ-2θ geometry. The first tests were performed with thin metal foils and some iron oxide mixtures. A time resolution of lower than 1 s together with a spatial resolution in one dimension of at least 50 µm is achieved. KW - Time resolution KW - Single-shot XAFS PY - 2016 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-370892 DO - https://doi.org/10.1107/S1600577516003969 SN - 1600-5775 IS - 23 SP - 769 EP - 776 PB - International Union of Crystallography CY - Chester, UK AN - OPUS4-37089 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Spranger, Holger A1 - Beckmann, Jörg A1 - Boehm, Rainer T1 - THz-ToF techniques for the detection of inherent discontinuities in dielectric materials based on a SAFT – and an optical layer reconstruction algorithm N2 - Electromagnetic waves with frequencies between 0.1 and 10 THz are described as THz-radiation (T-ray). The ability to penetrate dielectric materials makes T-rays attractive to reveal discontinuities in polymer and ceramic materials. THz-Time Domain Spectroscopy Systems (THz-TDS) are available on the market today which operates with THz-pulses transmitted and received by optically pumped semiconductor antennas. In THz-TDS the travelling time (ToF) and shape of the pulse is changed if it interacts with the dielectric material and its inherent discontinuities. A tomogram of the object under the test can be reconstructed from time of flight diffraction (ToFD) scans if a synthetic focusing aperture (SAFT) algorithm is applied. Otherwise, planar discontinuities like cracks in plastics or delaminated layers in composites can be abstracted as layers located at any angle in relation to the outer sample surface direction. A tomogram from the scanned sample can then be reconstructed in case the interactions of electromagnetic pulses with the existing inherent interfaces are detectable and a model is assumed which describes the device under the test as multilayer structure composed of thin layers with different dielectric properties. A short description of both the SAFT – and Optical Layer algorithm for the reconstruction of the inherent structure is initially given. Measurements on representative samples with a variety of artificially produced small and large scale. Reconstructed tomograms are presented to discuss and evaluate the benefits and limits of the two different reconstruction approaches. T2 - 19th World Conference on Non-Destructive Testing 2016 CY - Munich, Germany DA - 13.06.2016 KW - THz SAFT Optical layer reconstruction PY - 2016 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-365866 SN - 978-3-940283-78-8 VL - 158 SP - 1 EP - 10 AN - OPUS4-36586 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kömmling, Anja A1 - Grelle, Tobias A1 - Jaunich, Matthias A1 - Goral, Milan A1 - Wolff, Dietmar T1 - Three-dimensional thermal expansion of neat and irradiated (U)HMWPE materials at elevated temperatures N2 - The thermal expansion of polymeric parts can be an issue in many applications where the available space is limited, or exact dimensions of the part are required. For this study, a device was designed and built that allowed measuring the thermal expansion simultaneously in all three spatial directions on cubic samples with real-scale dimensions (78 mm edge length). The results are shown between 25 °C and 125 °C for two PE materials, one HMWPE and one tempered UHMWPE, for non-irradiated samples as well as cubes that have been irradiated with 100 and 400 kGy. The results measured with the new device were very similar to those measured with conventional thermo-mechanical analysis equipment and to literature data of UHMWPE. The HMWPE material shows a much larger thermal expansion coefficient in one direction compared to the other two directions during the first heating due to frozen stresses from the pressing step during material manufacturing. These stresses are mostly released by the expansion during the first heating, so that the expansion during the second heating is more uniform. The overall volumetric expansion is the same for both heating runs. By contrast, the tempered UHMWPE material shows no significant difference between first and second heating run, as the stresses from processing could already relax in the tempering step. The irradiation treatment does not affect the values significantly for the given test set-up. KW - Lupolen KW - Ultra high molecular weight polyethylene KW - GUR KW - Coefficient of thermal expansion KW - High temperature PY - 2022 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-563987 DO - https://doi.org/10.1016/j.polymertesting.2022.107841 SN - 0142-9418 VL - 117 SP - 1 EP - 8 PB - Elsevier Ltd. AN - OPUS4-56398 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Manke, I. A1 - Kardjilov, N. A1 - Schäfer, R. A1 - Hilger, A. A1 - Grothausmann, R. A1 - Strobl, M. A1 - Dawson, M. A1 - Grünzweig, C. A1 - Tötzke, C. A1 - David, C. A1 - Kupsch, Andreas A1 - Lange, Axel A1 - Hentschel, Manfred P. A1 - Banhart, J. T1 - Three-dimensional imaging of magnetic domains with neutron grating interferometry N2 - This paper gives a brief overview on3D imaging of magnetic domains with shearing grating neutron tomography. We investigated the three-dimensional distribution of magnetic domain walls in the bulk of a wedge-shaped FeSi single crystal. The width of the magnetic domains wasanalyzed at different locations within the crystal. Magnetic domains close to the tip of the wedge are much smaller than in the bulk. Furthermore, the three-dimensional shape of individual domains wasinvestigated. We discuss prospects and limitations of the applied measurement technique. KW - Neutron imaging KW - Tomography KW - Magnetic domains KW - Grating interferometry KW - Darkfield imaging KW - Shearing gratings KW - Talbot-Lau KW - Three-dimensional data quantification KW - Tomographic reconstruction PY - 2015 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-341919 DO - https://doi.org/10.1016/j.phpro.2015.07.057 SN - 1875-3892 VL - 69 SP - 404 EP - 412 PB - Elsevier B.V. CY - Amsterdam AN - OPUS4-34191 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - De la Hoz Alford, L. A1 - Pecanha de Souza, C. G. A1 - Paciornik, S. A1 - d` Almeida, J. R. M. A1 - Santos Leite, B. A1 - Avila, H. C. A1 - Léonard, F. A1 - Bruno, Giovanni T1 - Three-Dimensional Characterization of Polyurethane Foams Based on Biopolyols N2 - Two biopolyol-based foams derived from banana leaves (BL) or stems (BS) were produced, and their compression mechanical behavior and 3D microstructure were characterized. Traditional compression and in situ tests were performed during 3D image acquisition using X-ray microtomography. A methodology of image acquisition, processing, and analysis was developed to discriminate the foam cells and measure their numbers, volumes, and shapes along with the compression steps. The two foams had similar compression behaviors, but the average cell volume was five times larger for the BS foam than the BL foam. It was also shown that the number of cells increased with increasing compression while the average cell volume decreased. Cell shapes were elongated and did not change with compression. A possible explanation for these characteristics was proposed based on the possibility of cell collapse. The developed methodology will facilitate a broader study of biopolyol-based foams intending to verify the possibility of using these foams as green alternatives to the typical petrol-based foams. KW - Compression mechanical KW - Biopolyol KW - Banana KW - 3D microstructure KW - X-ray microtomography PY - 2023 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-571982 DO - https://doi.org/10.3390/ma16052118 SN - 1996-1944 VL - 16 IS - 5 SP - 1 EP - 12 PB - MDPI CY - Basel AN - OPUS4-57198 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kotschate, Daniel A1 - Gohlke, Dirk A1 - Heckel, Thomas T1 - Three dimensional examination of directivity pattern in immersion tank testing N2 - High resolution examination of safety-relevant parts in immersion tank testing with focussing probes is forming a main topic of modern non-destructive testing. For the usage of complex reconstruction methods and algorithms, an individual and detailed knowledge about the transmission behaviour of the used probes is essential, as this has a significant influence on the results of data reconstruction. Especially the knowledge about position and diameter of the focal point is needed to achieve the highest possible sensitivity. Through the individual position of the beam axis within the examined volume, a four dimensional metro logical determination of the acoustical pressure (x, y, z, t) is necessary. With the measured data it is possible to draw interferences about the sound field and acoustical pressure distribution. The presented work realized a method of automatic determination of the beam axis, the position of focal point and the focal diameter to support individual testing setups and transducer characterization. T2 - 7th International Symposium on NDT in Aerospace CY - Bremen, Germany DA - 16.11.2015 PY - 2015 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-339995 AN - OPUS4-33999 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Wagner, Jan A1 - Dudziak, Mateusz A1 - Falkenhagen, Jana A1 - Rockel, Daniel A1 - Reimann, H.-A A1 - Schartel, Bernhard T1 - This is the way: An evidence based route to phytic-acid–based flame retardant poly(lactide acid) N2 - A systematic sequence of materials was investigated to develop phytic-acid (Phyt)–based flame retarded poly (lactide acid) (PLA), while factoring in molecular weight (MW), crystallinity and mechanical properties. Synergistic approaches were developed based on combinations with lignin and expandable graphite (EG), as well as by applying different Phyt salts of melamine (Mel), piperazine (Pip), and arginine (Arg). Compounds were twin screw extruded, injection molded, hot pressed and investigated with thermal analysis, size exclusion chromatography, infrared spectroscopy, tensile testing, limited oxygen index (LOI), UL 94, cone calorimeter, and scanning electron microscope. 16.7 wt.% flame retardant (FR) slightly enhances crystallization while MW remains unchanged in PLA Phyt Arg and PLA Phyt Mel. LOI was improved to 43.7 vol.% for PLA Phyt Arg, UL 94 V0 achieved for PLA Phyt Pip. Cone calorimeter results show total heat evolved reduced by 14 %, maximum average rate of heat emission 43 % lower, and peak heat release rate reduced by 50 % for PLA Phyt Mel. Phyt Mel combined with EG increased the char yield of PLA to 20 wt.% and 15.5 wt.% at 600 and 900 ◦C, respectively. Phyt is exploited to enhance char yield, stabilize the intumescent char, and lower the apparent effective heat of combustion. The combination of Phyt Mel and EG was proposed as an efficient FR for PLA via an evidence based developing route. KW - Polylactide acid KW - Intumescent flame retardant KW - Phosphorous flame retardant KW - Phytic acid KW - Expandable graphite KW - Melamine PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-626395 DO - https://doi.org/10.1016/j.polymdegradstab.2025.111242 SN - 1873-2321 SN - 0141-3910 VL - 234 SP - 1 EP - 14 PB - Elsevier Ltd. AN - OPUS4-62639 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Valderrey, Virginia A1 - Gawlitza, Kornelia A1 - Rurack, Knut T1 - Thiourea- and Amino-Substituted Benzoxadiazole Dyes with Large Stokes Shifts as Red-Emitting Probe Monomers for Imprinted Polymer Layers Targeting Carboxylate-Containing Antibiotics N2 - Bifunctional fluorescent molecular oxoanion probes based on the benzoxadiazole (BD) chromophore are described which integrate a thiourea binding motif and a polymerizable 2-aminoethyl methacrylate unit in the 4,7-positions of the BD core. Concerted charge transfer in this electron donor-acceptor-donor architecture endows the dyes with strongly Stokes shifted (up to >250 nm) absorption and fluorescence. Binding of electron-rich carboxylate guests at the thiourea receptor leads to further analyte-induced red-shifts of the emission, shifting the fluorescence maximum of the complexes to ≥700 nm. Association constants for acetate are ranging from 1–5×105 M−1 in acetonitrile. Integration of one of the fluorescent probes through its polymerizable moiety into molecularly imprinted polymers (MIPs) grafted from the surface of submicron silica cores yielded fluorescent MIP-coated particle probes for the selective detection of antibiotics containing aliphatic carboxylate groups such as enoxacin (ENOX) at micromolar concentrations in highly polar solvents like acetonitrile. KW - Molecular imprinting KW - Anion recognition KW - Antibiotics KW - Benzoxadiazole dyes KW - Charge transfer KW - Fluorescence PY - 2022 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-545027 DO - https://doi.org/10.1002/chem.202104525 SN - 1521-3765 SP - 1 EP - 9 PB - Wiley-VCH AN - OPUS4-54502 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Silbernagl, Dorothee A1 - Sturm, Heinz A1 - Plajer, A. J. T1 - Thioanhydride/isothiocyanate/epoxide ring-opening terpolymerisation: sequence selective enchainment of monomer mixtures and switchable catalysis N2 - We report a new sequence selective terpolymerisation in which three monomers (butylene oxide (BO) A, PhNCS B and phtalic thioanhydride (PTA) C) are selectively enchained into an (ABA′C)n sequence. PTA/PhNCS/BO ring-opening terpolymerisation ROTERP can be coupled with CS2 ROTERP to generate tetrapolymers and with εDL ROP in switchable catalysis for blockpolymer synthesis. KW - Blockcopolymer KW - 1H-NMR KW - TGA KW - DSC KW - AFM PY - 2022 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-552339 DO - https://doi.org/10.1039/d2py00629d SP - 1 EP - 5 PB - Royal Society of Chemistry CY - Cambridge, UK AN - OPUS4-55233 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Yu, C.-H. A1 - Peng, R. L. A1 - Luzin, V. A1 - Sprengel, Maximilian A1 - Calmunger, M. A1 - Lundgren, J.-E. A1 - Brodin, H. A1 - Kromm, Arne A1 - Moverare, J. T1 - Thin-wall effects and anisotropic deformation mechanisms of an additively manufactured Ni-based superalloy N2 - Laser powder bed fusion (LPBF) of Ni-based superalloys shows great potential for high temperature applications, for example, as a burner repair application for gas turbines where the thin-walled structure is important. It motivates this work to investigate the evolution of microstructure and the anisotropic mechanical behavior when plate-like specimens are built with a thickness from 4 mm down to 1 mm. By performing texture analysis using neutron diffraction, a clear transition in fiber texture from <011> to <001> is indicated when the specimen becomes thinner. The residual stress shows no thickness dependence, and at the subsurface the residual stress reaches the same level as the yield strength. Due to the rough as-built surface, a roughness compensation method for mechanical properties of thin-walled structures is outlined and demonstrated. Tensile tests from room temperature up to 700 ◦C have been carried out. Anisotropic mechanical behavior is found at all temperatures, which is strongly related to the anisotropic texture evolution. Stronger texture evolution and grain rotations are discovered when the tensile loading is applied along the building direction. The mechanical behavior has been compared to a wrought material, where the high dislocation density and the subgrain structure of the LPBF material result in a higher yield strength. Combining the statistical texture analysis by neutron diffraction with mechanical testing, EBSD grain orientation mapping and the investigation of dislocation structures using transmission electron microscopy, this work illustrates the significance of texture for the thin-wall effect and anisotropic mechanical behavior of LPBF materials. KW - Hastelloy X KW - Hot tensile test KW - Crystallographic texture KW - Roughness KW - Residual stress KW - Dislocation density PY - 2020 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-518759 DO - https://doi.org/10.1016/j.addma.2020.101672 VL - 36 SP - 101672 PB - Elsevier B.V. AN - OPUS4-51875 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Lanzino, Maria Carolina A1 - Le, Long-Quan R. V. A1 - Wilbig, Janka A1 - Rheinheimer, Wolfgang A1 - Seidenstuecker, Michael A1 - Günster, Jens A1 - Killinger, Andreas T1 - Thin GB14 coatings on implants using HVSFS N2 - Enhancing osseointegration, the process by which medical implants securely bond to bone, is crucial for improving patient outcomes in orthopedics and dental surgery. Calcium alkali orthophosphates, with their superior bioactivity, resorbability, and chemical resemblance to bone minerals, have emerged as promising candidates for implant coatings. These materials offer improved solubility and lower melting points due to the substitution of calcium with potassium and sodium, along with the addition of magnesium oxide. This study investigates GB14 calcium alkali orthophosphate coatings applied via High Velocity Suspension Flame Spraying (HVSFS), a technique that enables precise control over coating properties. A porosity target of &gt;10% was set to promote bone growth, and we achieved porosities up to 13%, ensuring better cell penetration and stability at the implant-bone interface. Coatings were produced using different gas parameters and distances, with their microstructure and phase composition analyzed using scanning electron microscope (SEM), Vickers hardness testing and X-ray diffraction (XRD). Additionally, roughness and porosity were also assessed. Different coating’s microstructures were achieved by varying stand-off distance and gas parameters. Increasing stand-off distance while reducing gas stoichiometry enabled the production of calcium alkali orthophosphate coatings with fewer cracks, higher porosity and a hardness level comparable to that of state-of-the-art tricalcium phosphate (TCP) coatings. The sample with optimized properties in terms of achieved microstructure and topography was selected for in vitro testing using MG63 osteosarcoma cells to evaluate cell proliferation and adhesion. WST (I) assay, LDH assay, and live/dead staining confirmed the biocompatibility of the coatings, highlighting the potential of HVSFS to enhance osseointegration and outperform conventional methods in implantology. No relevant cytotoxicity could be shown and cells show a good proliferation over time. These results highlight thus the potential of HVSFS to produce thin, bioactive and resorbable coatings to enhance osseointegration. KW - Bio ceramics KW - Spray coating PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-623983 DO - https://doi.org/10.3389/fmats.2024.1522447 SN - 2296-8016 VL - 11 IS - 1522447 SP - 1 EP - 14 PB - Frontiers Media SA AN - OPUS4-62398 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Rhode, Michael A1 - Richter, Tim A1 - Mente, Tobias A1 - Mayr, P. A1 - Nitsche, A. T1 - Thickness and microstructure effect on hydrogen diffusion in creep‑resistant 9% Cr P92 steel and P91 weld metal N2 - Martensitic 9% Cr steels like P91 and P92 show susceptibility to delayed hydrogen assisted cracking depending on their microstructure. In that connection, effective hydrogen diffusion coefficients are used to assess the possible time-delay. Limited data on room temperature diffusion coefficients reported in literature vary widely by several orders of magnitude (mostly attributed to variation in microstructure). Especially P91 weld metal diffusion coefficients are rare so far. For that reason, electrochemical permeation experiments had been conducted using P92 base metal and P91 weld metal (in as-welded and heat-treated condition) with different thicknesses. From the results obtained, diffusion coefficients were calculated using to different methods, time-lag, and inflection point. Results show that, despite microstructural effects, the sample thickness must be considered as it influences the calculated diffusion coefficients. Finally, the comparison of calculated and measured hydrogen concentrations (determined by carrier gas hot extraction) enables the identification of realistic diffusion coefficients. KW - Creep-resistant steel KW - Diffusion KW - Hydrogen assisted cracking KW - Welding KW - Electrochemical permeation PY - 2021 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-540645 DO - https://doi.org/10.1007/s40194-021-01218-9 SN - 0043-2288 SP - 1 EP - 16 PB - Springer Nature Switzerland AG AN - OPUS4-54064 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Häusler, Ines A1 - Darvishi Kamachali, Reza A1 - Hetaba, W. A1 - Skrotzki, Birgit T1 - Thickening of T-1 Precipitates during Aging of a High Purity Al–4Cu–1Li–0.25Mn Alloy N2 - The age hardening response of a high-purity Al–4Cu–1Li–0.25Mn alloy (wt. %) during isothermal aging without and with an applied external load was investigated. Plate shaped nanometer size T1 (Al2CuLi) and θ′ (Al2Cu) hardening phases were formed. The precipitates were analyzed with respect to the development of their structure, size, number density, volume fraction and associated transformation strains by conducting transmission electron microscopy (TEM) and scanning transmission electron microscopy (STEM) studies in combination with geometrical Phase analysis (GPA). Special attention was paid to the thickening of T1 phase. Two elementary types of single-layer T1 precipitate, one with a Li-rich (Type 1) and another with an Al-rich (Defect Type 1) central layer, were identified. The results show that the Defect Type 1 structure can act as a precursor for the Type 1 structure. The thickening of T1 precipitates occurs by alternative stacking of These two elementary structures. The thickening mechanism was analyzed based on the magnitude of strain associated with the precipitation transformation normal to its habit plane. Long-term aging and aging under load resulted in thicker and structurally defected T1 precipitates. Several types of defected precipitates were characterized and discussed. For θ′ precipitates, a ledge mechanism of thickening was observed. Compared to the normal aging, an external load applied to the peak aged state leads to small variations in the average sizes and volume fractions of the precipitates. KW - Al-Cu-Li-alloy KW - Precipitation KW - T1 precipitate KW - Microstructure evolution KW - Thickening KW - Creep KW - Volume fraction KW - Number density KW - Strain difference PY - 2018 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-471207 DO - https://doi.org/10.3390/ma12010030 SN - 1996-1944 VL - 12 IS - 1 SP - 30, 1 EP - 23 PB - MDPI AN - OPUS4-47120 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Chaudhuri, Somsubhro A1 - Purayil, Sruthi Krishna Kunji A1 - Kruse, Julius A1 - Madia, Mauro A1 - Nielsen, Sören T1 - Thermography-Assisted Mechanical Testing of Cold-Spray (AM) Repair N2 - Cold Spray Additive Manufacturing (CSAM) is a solid-state process that is being increasingly used for structural repairs in aerospace and energy sectors. It enables the deposition of dense material at low temperatures by accelerating metal particles to supersonic velocities, thereby reducing thermal distortion. However, the structural integrity of CSAM repairs—particularly at the interface between the deposited layer and the substrate—remains a critical concern. Various post-treatments and characterization methods have been explored to optimize performance. While X-ray Computed Tomography (XCT) is effective for sub-surface inspection, it cannot be applied in situ during mechanical testing. Digital Image Correlation (DIC), a surface-based method, also lacks sub-surface sensitivity. To address this, Infrared Thermography (IRT) was employed alongside DIC during the tensile and fatigue testing of aluminum CSAM-repaired specimens. A cooled IRT camera operating at 200 FPS captured thermal data, with lock-in processing subsequently applied in post-processing. IRT successfully detected early interfacial damage and enabled the tracking of crack propagation, which was later confirmed through fracture surface analysis. This extended abstract presents findings from fatigue tests using IRT. T2 - 18th International Workshop on Advanced Infrared Technology and Applications (AITA 2025) CY - Kobe, Japan DA - 15.09.2025 KW - Thermography KW - Thermografie KW - Thermal stress analysis KW - Cold spray KW - Damage detection PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-642299 DO - https://doi.org/10.3390/proceedings2025129018 VL - 129 IS - 1 SP - 1 EP - 5 PB - MDPI CY - Basel AN - OPUS4-64229 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Krankenhagen, Rainer A1 - Röllig, Mathias A1 - Worzewski, Tamara A1 - Doroshtnasir, Manoucher T1 - Thermographic rotor blade inspection from larger distances – a promising tool for the maintenance of wind turbines N2 - The permanently increasing number of wind turbines requires suited inspection and monitoring methods to ensure liability and security. Concerning the inspection of ro-tor blades, only manual inspections are state of the art. Thermographic Testing (TT) has the potential to detect typical failures and damages on rotor blades. The paper presents some results of onsite measurements carried out as “passive thermogra-phy”, i.e. without a defined heating procedure. Due the totally contactless meas-urement principle, TT can be applied to rotating blades as well as to resting blades. Both methods will be compared with respect to their possible realization. T2 - WCNDT 2016 CY - Munich, Germany DA - 13.06.2016 KW - Wind turbine rotor blade KW - Thermographic inspection KW - Passive thermography KW - Nondestructive testing PY - 2016 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-366331 SN - 978-3-940283-78-8 SP - We.4.D.4., 1 EP - 8 AN - OPUS4-36633 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Lecompagnon, Julien A1 - Ahmadi, Samim A1 - Hirsch, Philipp Daniel A1 - Rupprecht, C. A1 - Ziegler, Mathias T1 - Thermographic detection of internal defects using 2D photothermal super resolution reconstruction with sequential laser heating N2 - Thermographic photothermal super resolution reconstruction enables the resolution of internal defects/inhomogeneities below the classical limit, which is governed by the diffusion properties of thermal wave propagation. Based on a combination of the application of special sampling strategies and a subsequent numerical optimization step in post-processing, thermographic super resolution has already proven to be superior to standard thermographic methods in the detection of one-dimensional defect/inhomogeneity structures. In our work, we report an extension of the capabilities of the method for efficient detection and resolution of defect cross sections with fully two-dimensional structured laser-based heating. The reconstruction is carried out using one of two different algorithms that are proposed within this work. Both algorithms utilize the combination of several coherent measurements using convex optimization and exploit the sparse nature of defects/inhomogeneities as is typical for most nondestructive testing scenarios. Finally, the performance of each algorithm is rated on reconstruction quality and algorithmic complexity. The presented experimental approach is based on repeated spatially structured heating by a high power laser. As a result, a two-dimensional sparse defect/inhomogeneity map can be obtained. In addition, the obtained results are compared with those of conventional thermographic inspection methods that make use of homogeneous illumination. Due to the sparse nature of the reconstructed defect/inhomogeneity map, this comparison is performed qualitatively. KW - Thermography KW - Super resolution KW - NDT KW - Inspection KW - Internal defects PY - 2022 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-548351 DO - https://doi.org/10.1063/5.0088102 SN - 1089-7550 VL - 131 IS - 18 SP - 1 EP - 12 PB - AIP Publishing AN - OPUS4-54835 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Unnikrishnakurup, Sreedhar A1 - Myrach, Philipp A1 - Polomski, Benjamin A1 - Le Claire, Elisabeth A1 - Vengara, N. A1 - Balasubramaniam, Krishnan A1 - Ziegler, Mathias T1 - Thermographic crack detection in hot steel surfaces N2 - The detection and characterization of surface cracks in steel specimens prior to damage is a technologically and economically highly significant task and is of utmost importance when it comes to safety-relevant structures. In steel production where steel billets at high temperatures have to be inspected while moving a number of well-established NDT methods cannot be applied. Laser thermography however is a promising candidate to serve as a fast, non-contact and remote tool in this case. We present a study that shows that the crack detection capabilities of laser thermography can be extended also to specimens at high temperature. A combination of inductive and laser heating allows to systematically study the contrast formation as well as the optimization of the important measurement parameters. The experiments are accompanied by FEM simulations that provide a better insight of the physical correlations and support the experimental developments. The aim of these studies is to develop a system with high inspection speed and detection performance to be in-line operated under the hostile environment of steel production lines. T2 - 19th World Conference on Non-Destructive Testing (WCNDT 2016) CY - Munich, Germany DA - 13.06.2016 KW - In-line Monitoring KW - Laser Infrared thermography KW - Cracks KW - Induction heating KW - Steel billets KW - FEM simulation PY - 2016 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-389161 UR - http://ndt.net/?id=19573 SN - 1435-4934 VL - 21 IS - 7 SP - 1 EP - 8 PB - NDT.net CY - Kirchwald AN - OPUS4-38916 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Ikeda, Yuki A1 - Wallis, Theophilus A1 - Maaß, Robert A1 - Darvishi Kamachali, Reza T1 - Thermodynamics of grain boundary segregation transition and their relevance for liquid metal embrittlement in Fe-Zn system N2 - Grain boundaries (GBs) are common sites of failure in polycrystalline materials. Recently, a massive Zn segregation transition at Fe GBs was discovered and shown to act as a potent precursor of liquid metal embrittlement (LME) in the Fe-Zn system (Kamachali et al., Scripta Materialia 238 (2024) 115758). In this study, we elaborate on how temperature, GB type and the chemo-structurally coupled phase decomposition at the GB impact this segregation transition. CALPHAD and atomistic simulation data were utilized as inputs to conduct quantitative density-based thermodynamic modeling and phase-field simulations across various GBs, alloy compositions, and temperatures. We reveal that once the segregation transition becomes possible, the GB structural variation stabilizes spinodally formed Zn-rich phases within the GB region, with a higher tendency in disordered GBs. GB phase diagrams were constructed to identify and analyze the range of critical temperatures and alloy compositions associated with the segregation transition. The phase diagrams reveal that the miscibility gap for more disordered GB expands and, although the segregation transition is inevitable and occurs for all GBs, the barrier to triggering it is lower for more disordered GBs. Based on our thermodynamic analyses, potential processing modifications and GB engineering strategies for mitigating segregation-induced LME are thoroughly discussed. KW - Thermodynamics KW - Phase-Field Modelling KW - Steels PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-634145 DO - https://doi.org/10.1016/j.actamat.2025.121134 SN - 1359-6454 VL - 296 SP - 1 EP - 11 PB - Elsevier BV AN - OPUS4-63414 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Herzel, Hannes A1 - Grevel, K.-D. A1 - Emmerling, Franziska A1 - Dachs, E. A1 - Benisek, A. A1 - Adam, Christian A1 - Majzlan, J. T1 - Thermodynamic properties of calcium alkali phosphates Ca(Na,K)PO4 N2 - Calcium alkali phosphates Ca(Na,K)PO4 are main constituents of bioceramics and thermochemically produced phosphorus fertilizers because of their bioavailability. Sparse thermodynamic data are available for the endmembers CaNaPO4 and CaKPO4. In this work, the missing data were determined for the low-temperature phase modifications of the endmembers CaNaPO4 and CaKPO4 and three intermediate Ca(Na,K)PO4 compositions. Standard enthalpy of formation ranges from - 2018.3 ± 2.2 kJ mol-1 to - 2030.5 ± 2.1 kJ mol-1 and standard entropy from 137.2 ± 1.0 J mol-1 K-1 to 148.6 ± 1.0 J mol-1 K-1 from sodium endmember b-CaNaPO4 to potassium endmember b0-CaKPO4. Thermodynamic functions are calculated up to 1400 K for endmembers and the sodium-rich intermediate phase b-Ca(Na0.93K0.07)PO4. Functions above 640 K are extrapolated because of the phase transition from low- to high-temperature phase. Impurities in the synthesized intermediate phases c-Ca(Na0.4K0.6)PO4 and c-Ca Na0.35K0.65)PO4 and one additional phase transition around 500 K impeded the determination of high-temperature thermodynamic functions. In general, data for phase transition temperatures agree with the previously reported phase diagrams. KW - Formation enthalpy KW - Heat capacity KW - Phase transformation KW - Bioceramics KW - Phosphorus fertilizer KW - Entropy PY - 2020 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-507640 DO - https://doi.org/10.1007/s10853-020-04615-5 VL - 55 SP - 8477 EP - 8490 PB - Springer AN - OPUS4-50764 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Schröder, Nina A1 - Rhode, Michael A1 - Kannengießer, Thomas T1 - Thermodynamic prediction of precipitations behaviour in HAZ of a gas metal arc welded S690QL with varying Ti and Nb content N2 - For a significant increase in the strength of high-strength fine-grained structural steels with a nominal yield strength ≥690 MPa, the addition of microalloying elements such as Nb and Ti is required. The standard specifications for the chemical composition of these steels (e.g., in EN 10025-6) often only give the manufacturer limit contents to achieve the defined properties. The effect of the alloying elements in the heat affected zone (HAZ) is sometimes completely contrary. This makes it difficult to adequately predict the batch dependency regarding weldability and the load-bearing behaviour of the welded joint. Three different micro-alloyed steels of the grade S690QL were produced on a laboratory scale, focusing on different Nb and Ti contents. To investigate the tempering effect, these were gas metal arc welded in three layers. In addition to metallographic investigations of individual HAZ areas, thermodynamic phase calculations were carried out using Thermo-Calc, following variations in the chemical composition. This provides an understanding of phase transformation, precipitation growth, and dissolution during welding as a function of temperature and cooling conditions. The results show a divergent metallurgical behaviour in the HAZ of the three different micro-alloyed steels. Thereby, the Ti micro-alloyed grade showed a strong softening of the HAZ in contrast to the Nb micro-alloyed grade. This can be attributed to a contrary precipitation behaviour during welding. KW - High-strength structural steel KW - Gas metal arc welding KW - HAZ-softening KW - Microalloying influences KW - Thermodynamic simulation PY - 2023 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-579988 DO - https://doi.org/10.1007/s40194-023-01550-2 SN - 0043-2288 SP - 1 EP - 10 PB - Springer AN - OPUS4-57998 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Lozano-Martín, D. A1 - Tuma, Dirk A1 - Kipphardt, Heinrich A1 - Khanipour, Peyman A1 - Chamorro, C. R. T1 - Thermodynamic characterization of the (H2 + C3H8) system significant for the hydrogen economy: Experimental (p, rho, T) determination and equation-of-state modelling N2 - For the gradual introduction of hydrogen in the energy market, the study of the properties of mixtures of hydrogen with typical components of natural gas (NG) and liquefied petroleum gas (LPG) is of great importance. This work aims to provide accurate experimental (p, rho, T) data for three hydrogen-propane mixtures with nominal compositions (amount of substance, mol/mol) of (0.95 H2 + 0.05 C3H8), (0.90 H2 + 0.10 C3H8), and (0.83 H2 + 0.17 C3H8), at temperatures of 250, 275, 300, 325, 350, and 375 K, and pressures up to 20 MPa. A single-sinker densimeter was used to determine the density of the mixtures. Experimental density data were compared to the densities calculated from two reference equations of state: the GERG-2008 and the AGA8-DC92. Relative deviations from the GERG-2008 EoS are systematically larger than those from the AGA8-DC92. They are within the ±0.5% band for the mixture with 5% of propane, but deviations are higher than 0.5% for the mixtures with 10% and 17% of propane, especially at low temperatures and high pressures. Finally, the sets of new experimental data have been processed by the application of two different statistical equations of state: the virial equation of state, through the second and third virial coefficients, B(T, x) and C(T, x), and the PC-SAFT equation of state. KW - Hydrogen-containing gas mixture KW - Density data KW - Equation of state KW - Virial coefficients PY - 2023 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-570056 DO - https://doi.org/10.1016/j.ijhydene.2022.11.170 SN - 0360-3199 VL - 48 IS - 23 SP - 8645 EP - 8667 PB - Elsevier B. V. CY - Amsterdam AN - OPUS4-57005 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Lozano-Martín, D. A1 - Pazoki, F. A1 - Kipphardt, Heinrich A1 - Khanipour, P. A1 - Tuma, Dirk A1 - Horillo, A. A1 - Chamorro, C. R. T1 - Thermodynamic (p, ρ, T) characterization of a reference high-calorific natural gas mixture when hydrogen is added up to 20 % (mol/mol) N2 - The injection of hydrogen into the natural-gas grid is an alternative during the process of a gradual decarbonization of the heat and power supply. When dealing with hydrogen-enriched natural gas mixtures, the performance of the reference equations of state habitually used for natural gas should be validated by using high-precision experimental thermophysical data from multicomponent reference mixtures prepared with the lowest possible uncertainty in composition. In this work, we present experimental density data for an 11-compound high-calorific (hydrogen-free) natural gas mixture and for two derived hydrogen-enriched natural gas mixtures prepared by adding (10 and 20) mol-% of hydrogen to the original standard natural gas mixture. The three mixtures were prepared gravimetrically according to ISO 6142–1 for maximum precision in their composition and thus qualify for reference materials. A single-sinker densimeter was used to determine the density of the mixtures from (250–350) K and up to 20 MPa. The experimental density results of this work have been compared to the densities calculated by three different reference equations of state for natural gas related mixtures: the AGA8-DC92 EoS, the GERG-2008 EoS, and an improved version of the GERG-2008 EoS. While relative deviations of the experimental density data for the hydrogen-free natural gas mixture are always within the claimed uncertainty of the three considered equations of state, larger deviations can be observed for the hydrogen-enriched natural gas mixtures from any of the three equations of state, especially for the lowest temperature and the highest pressures. KW - Hydrogen-enriched natural gas KW - Single-sinker densimeter KW - High-pressure density KW - Equations of state PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-604742 DO - https://doi.org/10.1016/j.ijhydene.2024.05.028 SN - 0360-3199 VL - 70 SP - 118 EP - 135 PB - Elsevier BV CY - Amsterdam AN - OPUS4-60474 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Leers, K. A1 - Arnold, U. A1 - Herzel, Hannes A1 - Adam, Christian A1 - Burkhardt, J. T1 - Thermochemically Treated Sewage Sludge Ash From Pilot-Scale Production as P-Fertilizer for Spring Wheat and Maize in Different Soil Conditions N2 - Background P-fertilizers made from sewage sludge ash (SSA) may be suitable substitutes for rock phosphate (RP)-based fertilizers and contribute to sustainable use of waste. In this context, the thermochemical AshDec treatment of SSA (TC-SSA) has been continuously improved and has emerged as a possible method to produce plant-available and low-pollutant P-fertilizers. Aim Evaluation of the P-fertilizer efficacy of TC-SSA produced in pilot trials in vegetation experiments with different plants, soils, and fertilizer doses. Methods TC-SSA was tested in pot experiments for spring wheat and maize on different soils and at two doses (0.2 and 0.4 g fertilizer P pot−1) and is compared to untreated SSA (USSA), RP, Struvite, triple superphosphate (TSP), and a control without P-fertilization (Zero P). Pot experiments are complemented by an analysis of fertilizer P-solubility. Results P-solubility of SSA with different extraction methods increased due to the thermochemical treatment, whereas the water-insoluble property remained. In contrast to RP or USSA, TC-SSA enriched calcium–acetate–lactate extractable soil P to the same extent as TSP. Plant biomass and P-uptake increased with TC-SSA compared to Zero P, RP, and USSA and were in most cases equal to TSP fertilization under different soil conditions. In contrast, the effects of RP and USSA varied among soils but, mostly, did not exceed plant biomass and P-uptake of the unfertilized control. Conclusion TC-SSA has an increased fertilizer efficacy compared to USSA and is an effective P-fertilizer for spring wheat and maize in different soil conditions. KW - Phosphorus KW - Fertilizer KW - Thermochemical KW - Maize PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-648251 DO - https://doi.org/10.1002/jpln.70035 SN - 1522-2624 VL - 189 IS - 1 SP - 81 EP - 93 PB - Wiley-VCH AN - OPUS4-64825 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Smol, M. A1 - Adam, Christian A1 - Kugler, Stefan T1 - Thermochemical Treatment of Sewage Sludge Ash (SSA)—Potential and Perspective in Poland N2 - Phosphorus (P) recovery from sewage sludge ash (SSA) is one of the most promising approaches of phosphate rock substitution in mineral fertilizers and might be a sustainable way to secure supply of this raw material in the future. In the current investigation, the process of thermochemical treatment of SSA was applied to SSA coming from selected mono-incineration plants of municipal sewage sludge in Poland (Cracow, Gdansk, Gdynia, Lodz, Kielce and Szczecin). The Polish SSA was thermochemically converted in the presence of sodium (Na) additives and a reducing agent (dried sewage sludge) to obtain secondary raw materials for the production of marketable P fertilizers. The process had a positive impact on the bioavailability of phosphorus and reduced the content of heavy metals in the obtained products. The P solubility in neutral Ammonium citrate, an indicator of its bioavailability, was significantly raised from 19.7–45.7% in the raw ashes and 76.5–100% in the thermochemically treated SSA. The content of nutrients in the recyclates was in the range of 15.7–19.2% P2O5, 10.8–14.2% CaO, 3.5–5.4% Na2O, 2.6–3.6% MgO and 0.9–1.3% K2O. The produced fertilizer raw materials meet the Polish norms for trace elements covered by the legislation: the content of lead was in the range 10.2–73.1 mg/kg, arsenic 4.8–22.7 mg/kg, Cadmium 0.9–2.8 mg/kg and mercury <0.05 mg/kg. Thus, these products could be potentially directly used for fertilizer production. This work also includes an analysis of the possibilities of using ashes for fertilizer purposes in Poland, based on the assumptions indicated in the adopted strategic and planning documents regarding waste management and fertilizer production. KW - Sewage Sludge Ashes KW - Critical raw materials KW - Phosphorus KW - Fertilizer KW - Sewage Sludge PY - 2020 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-514468 DO - https://doi.org/10.3390/en13205461 VL - 13 IS - 20 SP - 5461 AN - OPUS4-51446 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Schmalz, Alina A1 - Eby, Charles Gaston A1 - Moss, Caitlin A1 - Bhattacharya, Biswajit A1 - Emmerling, Franziska T1 - Thermally Robust 1D Cu(I) Phosphonate Coordination Polymer Exhibiting Enhanced Proton Conductivity via Humidity‐Driven Pathways N2 - The development of thermally stable solid-state proton conductors (SSPCs) is crucial for advancing energy-conversion devices such as proton-exchange membrane fuel cells (PEMFCs). In this work, we report the solvothermal synthesis and characterization of a novel, 1D Cu(I) coordination polymer, {Cu(ADP)0.5(BPY)}n (BAM-5), based on anthracenediylphosphonate (H2ADP) and 4,40 -bipyridine (BPY). Single-crystal X-ray diffraction revealed that BAM-5 crystallizes in the triclinic space group P1 and shows a 1D ladder structure connected by the H2ADP and organic BPY linkers, which is assembled into a 2D layer via O−H···O hydrogen bonding interactions between uncoordinated oxygen and the O−H of the phosphonate group. Thermogravimetric and dynamic water sorption analysis demonstrated exceptional thermal robustness of BAM-5 until 230°C and notable water affinity. Proton conductivity measurements found increasing proton conductive properties with increasing temperature and relative humidity.The latter is correlated with the material’s water uptake since the structure itself does not contain any permanent lattice water molecules. A maximum proton conductivity of 6.6 × 10−6 S cm−1 was found at 80°C and 98% RH. To the best of our knowledge, no dense, nonporous 1D coordination polymer without lattice or coordinated solvent molecules has shown comparable proton con� ductivity. The high activation energy suggests a combination of both, a Grotthuss-type proton hopping through the hydrogen� bonded framework, and a vehicular process, in which protons are carried along with absorbed water molecules. KW - Coordination polymers KW - Phosphonate ligand KW - Proton conduction KW - X-ray diffraction PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-651382 DO - https://doi.org/10.1002/zaac.202500187 SN - 0044-2313 SP - 1 EP - 8 PB - Wiley VHC-Verlag AN - OPUS4-65138 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Szczerba, Wojciech A1 - Schott, M. A1 - Riesemeier, Heinrich A1 - Thünemann, Andreas A1 - Kurth, D.G. T1 - Thermally induced structural rearrangement of the Fe(II) coordination geometry in metallo-supramolecular polyelectrolytes N2 - Rigid rod-type metallo-supramolecular coordination polyelectrolytes with Fe(II) centres (Fe-MEPEs) are produced via the self-assembly of the ditopic ligand 1,4-bis(2,2':6',2''-terpyridine-4'-yl)benzene (tpy-ph-tpy) and Fe(II) acetate. Fe-MEPEs exhibit remarkable electrochromic properties; they change colour from blue to transparent when an electric potential is applied. This electrochemical process is generally reversible. The blue colour in the ground state is a result of a metal-to-ligand charge transfer at the Fe(II) centre ion in a quasi-octahedral geometry. When annealed at temperatures above 100 °C, the blue colour turns into green and the formerly reversible electrochromic properties are lost, even after cooling down to room temperature. The thermally induced changes in the Fe(II) coordination sphere are investigated in situ during annealing of a solid Fe-MEPE using X-ray absorption fine structure (XAFS) spectroscopy. The study reveals that the thermally induced transition is not accompanied by a redox process at the Fe(II) centre. From the detailed analysis of the XAFS spectra, the changes are attributed to structural changes in the coordination sphere of the Fe(II) site. In the low temperature state, the Fe(II) ion rests in a quasi-octahedral coordination environment surrounded by six nitrogen atoms of the pyridine rings. The axial Fe–N bond length is 1.94 Å, while the equatorial bond length amounts to 1.98 Å. In the high temperature state, the FeN6-site exhibits a distortion with the axial Fe–N bonds being shortened to 1.88 Å and the equatorial Fe–N bonds being elongated to 2.01 Å. KW - Metallo-supramolecular polyelectrolytes KW - Electrochromism KW - XANES KW - EXAFS KW - Local structure KW - Thermal stability PY - 2014 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-317331 DO - https://doi.org/10.1039/c4cp01187b SN - 1463-9076 SN - 1463-9084 VL - 16 IS - 36 SP - 19694 EP - 19701 PB - The Royal Soc. of Chemistry CY - Cambridge AN - OPUS4-31733 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kovacevic, E. A1 - Strunskus, T. A1 - Santhosh, N. M. A1 - Zavasnik, Z. A1 - Unger, Wolfgang A1 - Sauvage, T. A1 - Ammar, M.-R. A1 - Cvelbar, U. A1 - Berndt, J. T1 - Thermal stability studies of plasma deposited hydrogenated carbon nitride nanostructures N2 - Thermally stable carbon nitride nanostructures have potential applications in surface coatings and automotive fields. In this work, hydrogenated nitrogen-rich carbon nitride nanoparticles have been synthesised via low-pressure low-power plasma vapour deposition technique from methane/Nitrogen gas mixture in a dry process. Thermal stability of the initially prepared hydrogenated carbon Nitride structures has been analysed by near-edge X-ray absorption fine-structure spectroscopy (NEXAFS, insitu), Raman spectroscopy, scanning and transmission electron microscopy and nuclear reaction Analysis (NRA). Thermal studies reveal the excellent stability of the material and nitrogen-rich characteristics (N/C ratio 0.5e0.2 ± 0.01). The obtained results suggest transformation of sp3-rich as-deposited carbon Nitride into sp2-carbon phase with more graphitic features upon thermal annealing. Such in-situ thermal studies of plasma deposited carbon nitrides confirm the conversion of sp3-rich phase to sp2-rich carbon phase at the critical temperature (about 450 K), without a huge loss in nitrogen content. The analysis revealed that the material is a stable plasma deposit after this critical temperature up to >1100 K. Additionally, super hydrophilic carbon nitride nanostructure transforms into a hydrophobic surface after thermal annealing. These thermally stable hydrophobic carbon nitride nanoparticles could be used as a promising material for the hydrophobic coatings for various applications, especially for harsh conditions. KW - Carbon nanoparticles KW - Hydrogenated nanostructures KW - Plasma deposition KW - NEXAFS KW - Thermal annealing PY - 2021 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-536163 DO - https://doi.org/10.1016/j.carbon.2021.08.008 SN - 0008-6223 VL - 184 SP - 82 EP - 90 PB - Elsevier Ltd. AN - OPUS4-53616 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Amano, Kofi Owusu Ansah A1 - Tschirschwitz, Rico A1 - Gimadieva, Elena A1 - Köhler, Florian A1 - Krause, Ulrich T1 - Thermal runaway and explosibility of the gas release from 18650 sodium-ion cells of NFM chemistry N2 - The present study investigates the thermal runaway behaviour and explosibility of the gas mixture released from sodium-ion batteries (SIBs). A total of 30 tests comprising two test series were performed using 18650 SIBs with a NaNi1/3Fe1/3Mn1/3O2 (NFM) chemistry. The cells of SOC level = 0 %, 25 %, 50 %, 75 % and 100 % were subjected to thermal abuse inside a 10 L pressurized reaction vessel. In test series 1, the tests were performed in an air atmosphere. In test series 2, an inert atmosphere was used. First, the total amount of gas released from the SIBs was calculated based on the temperature and pressure measured in the reaction vessel. Subsequently, a gas composition analysis was performed using a Fourier-transformed infrared (FTIR) spectrometer. This study revealed that the thermal runaway in SIBs could be categorized into four phases. At the onset of thermal runaway, the thermal runaway-induced explosion of the cells resulted in a rate of temperature rise ranging from 2 K/s to 70 K/s. The investigation further revealed a peak reaction temperature of 415 ◦C and a maximum pressure of 4 bar could be reached at thermal runaway in the 10 L vessel. The gas release of up to 5 ± 0.3 L (4 ± 0.2 L/Ah, 1.3 ± 0.1 L/Wh) from test series 1 and 2.4 ± 0.2 L (2 ± 0.1 L/Ah, 0.53 ± 0.04 L/Wh) from test series 2 showed a dependence on SOC and failure environment used. By applying Le Chatelier's mixing rule, the measured gas release from the air atmosphere showed a calculated lower explosion limit and upper explosion limit values of 4.8 % and 24 % in volume fraction, respectively. KW - Sodium-ion battery KW - Thermal runaway KW - Gas release KW - Gas explosion KW - Explosion limit PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-631782 DO - https://doi.org/10.1016/j.est.2025.116614 SN - 2352-152X VL - 122 SP - 1 EP - 16 PB - Elsevier Ltd. AN - OPUS4-63178 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Bernardy, Christopher A1 - Habib, Abdel Karim A1 - zur Nedden, Philipp Maximilian A1 - von Saldern, Jakob Georg Raimund A1 - Beuth, Jan Paul A1 - Orchini, Alessandro T1 - Thermal Radiation Of Inclined Large Scale Hydrogen Jet Flames N2 - In order to assess the thermal radiation emanating from hydrogen jet flames, experiments under real scale conditions were carried out at the Test Site Technical Safety of BAM. Herein, the behavior of inclined hydrogen jet flames was investigated. The aim of the work is to determine the Surface Emissive Power (SEP) and radiant heat fraction of these flames and to provide a reliable dataset for model evaluation purposes. Since the aforementioned values are not directly measurable, the incident heat radiation was measured at defined distances from the flame, as well as the flame’s shape and size. The required values were then derived from these measurements. The hydrogen releases ranged from 0.0125 kg/s to 0.175 kg/s with a 30 mm orifice. The mass flows were held constant during the releases, nevertheless a transient behavior of the flame could be observed since the experiments were carried out under open field conditions, with unsteady wind fields. In the literature, the flame lengths are often determined using visible light imaging, either by injecting coloring substances in the low light emitting hydrogen jet flame or by carrying out the measurements in darkness. In this work the jet flames were visualized using infrared (IR) and OH* imaging. The recorded flame shapes and resulting flame lengths are compared. Results from this showed that the flame lengths determined with OH* and IR recordings differ greatly. A flame length ratio lf OH*/lf IR in the range of 0.47–0.62 can be found. In addition, the SEP differ also in the range of 10 kW/m2–16 kW/m2 (IR) and 40 kW/m2–80 kW/m2 (OH*) for hydrogen jet flames due to differences in the determined flame surface. Conclusions regarding the determined xRAD values for IR and OH* result in approximately the same range of 0.031–0.043. T2 - 11th Iinternational conference on hydrogen safety 2025 CY - Seoul, Republic of Korea DA - 22.09.2025 KW - Hydrogen safety KW - Jet flames KW - Thermal radiation KW - Large scale experiment PY - 2026 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-655181 DO - https://doi.org/10.58895/hysafe.27 SN - 2943-5935 VL - 3 IS - 1 SP - 39 EP - 50 PB - Karlsruhe Institute of Technology Library AN - OPUS4-65518 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -