TY - JOUR A1 - Simon, Fabian A1 - von der Au, Marcus A1 - Gehrenkemper, Lennart A1 - Meermann, Björn T1 - An optimized method for PFAS analysis using HR–CS–GFMAS via GaF detection N2 - The analysis of per- and polyfluoroalkyl substances (PFAS) via sum parameters like extractable organic fluorine (EOF) in combination with high resolution-continuum source-graphite furnace molecular absorption spectrometry (HR–CS–GFMAS) is highly promising regarding fluorine sensitivity and selectivity. However, the HR–CS–GFMAS method includes several drying and heating steps which can lead to losses of volatile PFAS before the molecular formation step using e.g., GaF formation. Hence, the method leads to a strong discrimination of PFAS within the EOF depending on their physical/chemical properties and is therefore associated with reduced accuracy. To reduce this discrepancy and to indicate realistic PFAS pollution values, an optimization of the HR–CS–GFMAS method for PFAS analysis is needed. Hence, we determined fluorine response factors of several PFAS with different physical/chemical properties upon application of systematic optimization steps. We could therefore improve the method's sensitivity for PFAS analysis using a modifier drying pre-treatment step followed by a sequential injection of sample solutions. The highest improvement in sensitivity of volatile PFAS was shown upon addition of a Mg modifier during drying pre-treatment. Thereby, during optimization the relative standard deviation of fluorine response factors could be reduced from 55 % (initial method) to 27 % (optimized method) leading to a more accurate determination of organofluorine sum parameters. The method provides an instrumental LOD and LOQ of β(F) 1.71 μg/L and 5.13 μg/L, respectively. Further validation aimed to investigate several matrix effects with respect to water matrices. Here, substance-specific behavior was observed. For example, perfluorooctanoic acid (PFOA) which was used as calibrator, showed signal suppressions upon high chloride concentrations (>50 mg/L). Hence, a thorough separation of Cl from analytes during sample preparation is needed for accurate sum parameter analysis. KW - PFAS KW - GF-AAS KW - Method optimization PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-610522 DO - https://doi.org/10.1016/j.talanta.2024.126811 VL - 281 SP - 1 EP - 11 PB - Elsevier B.V. AN - OPUS4-61052 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Lu, Xin A1 - Krebber, Katerina T1 - Suppression of Rayleigh fading induced errors in φOTDR by different pulse widths for improving the reliability of civil infrastructure monitoring N2 - Rayleigh fading is a widely observed phenomenon in the many fields, such as wireless communication and optical imaging. It is also the main factor limiting the performance of the phase-sensitive optical time domain reflectometry (φOTDR). The low SNR at the fading points results in a large measurement error, severely affecting the reliability of civil infrastructure monitoring. The proposed method involves changing the pulse width during measurements to suppress the impact of fading. Experimental result shows that the number of fading points is greatly reduced by ∼ 96 % and the measurement error is reduced by more than 5 times. Unlike existing methods, this approach requires no hardware modifications, making it applicable to almost all current phase-based φOTDR systems. The versatility and effectiveness of this method make it an excellent candidate for infrastructure monitoring and related fields. KW - Distributed fiber sensing KW - Optical fiber sensing KW - Phase-sensitive optical time domain reflectometry KW - Infrastructure monitoring KW - Rayleigh fading PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-614208 DO - https://doi.org/10.1016/j.optlastec.2024.111927 SN - 1879-2545 VL - 181 SP - 1 EP - 9 PB - Elsevier Ltd. AN - OPUS4-61420 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Řepka, Jakub A1 - Vlach, Tomáš A1 - Hájek, Jakub A1 - Fürst, Richard A1 - Hájek, Petr T1 - Flexural behavior of hollow HPC beams with cross-wound CFRP shear reinforcement N2 - This article presents cross-wound carbon fiber-reinforced polymer (CFRP) shear reinforcement of hollow high-performance concrete (HPC) beams. A removable mold used to form the core of the hollow elements was utilized for reinforcement positioning. Basalt fiber-reinforced polymer (BFRP) tensile reinforcement was attached to the removable mold by spacers, and the CFRP shear reinforcement was cross-wound around the BFRP bars from carbon rovings oriented at ± 45° from the longitudinal axis. The flexural, and shear performance of the hollow HPC structural beams was evaluated. To set a comparison, specimens without any shear reinforcement and specimens made of HPC with 80 kg/m3 of dispersed short steel fibers were tested alongside them. The shear capacity of the specimens with CFRP reinforcement evaluated in a three-point bending test was up to 73 % higher compared to those with dispersed steel fibers. The cross-wound CFRP reinforcement also complemented the BFRP tensile reinforcement, as for specimens that failed in tension, the ones with CFRP reinforcement achieved 25 % higher ultimate flexural strength compared to those with dispersed steel fibers. The inclined CFRP mesh affected the orientation of the critical shear crack resulting in higher shear capacity at a longer shear span. Direct effect of the longitudinal reinforcement ratio on the shear capacity was observed. KW - Hollow beam KW - Cross-wound reinforcement KW - Shear capacity KW - Carbon FRP (CFRP) KW - Basalt FRP (BFRP) KW - High-performance concrete (HPC) PY - 2025 DO - https://doi.org/10.1016/j.engstruct.2024.119055 VL - 322 SP - 1 EP - 10 PB - Elsevier B.V. AN - OPUS4-61262 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Krone, David A1 - Esche, Erik A1 - Skiborowski, Mirko A1 - Repke, Jens-Uwe T1 - Optimization-based process synthesis by phenomena-based building blocks and an MINLP framework featuring structural screening N2 - An existing approach for optimization-based process synthesis with abstracted phenomena-based building blocks (PBB) is extended by implementing it into a novel MINLP framework with structural screening. Consistency across the multilayer MINLP framework is guaranteed by creating a MathML/XML data model and subsequently exporting the code to the different program parts. The novel framework focuses both on fidelity by implementing thermodynamically sound models and on generality by employing a state-space superstructure that spans a large search space. In order to retain tractability, we insert a structural screening layer which prescreens based on binary decision variables of the superstructure by graph- and rule-based analyses, penalizing non-physical instances without solution of the underlying MINLP. The MINLP framework is successfully applied on two challenging synthesis tasks to determine the separation of the feed streams of benzene and toluene, as well as of n-pentane, n-hexane, and n-heptane utilizing superstructures with two, respectively four PBB. KW - Process synthesis KW - Superstructure optimization KW - Distillation KW - Mathematical programming KW - Structural screening PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-621955 DO - https://doi.org/10.1016/j.compchemeng.2024.108955 VL - 194 SP - 1 EP - 19 PB - Elsevier Ltd. AN - OPUS4-62195 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Wilrich, Cordula A1 - Wilrich, Thomas T1 - Explosion bei Tankinstandhaltung N2 - Bei Instandhaltungsarbeiten an einem Tank kam es – ohne Personenschaden – zu einer Explosion. Da als Ursache nur solche aus dem Obhuts- und Gefahrenbereich des mit der Instandhaltung beauftragten Dienstleisters und seines Subunternehmers in Frage kamen, mussten diese sich im Zuge einer Beweislastumkehr entlasten, d.h. sie mussten aufzeigen, dass sie nicht pflichtwidrig gehandelt haben. Das gelang ihnen nicht und das Gericht ging zur Begründung auch detailliert auf Technische Regeln zur Betriebssicherheit ein (was in Urteilsbegründungen eher selten vorkommt). Die Gefährdungsbeurteilung spielte dahingegen in der Urteilsbegründung keine Rolle. Dies zeigt wie unterschiedlich Juristen und Arbeitsschützer denken: Zur Klärung einer möglichen Haftung sind die Pflichtverletzung und der Kausalzusammenhang relevant, während für den Arbeitsschutz die Prävention im Vordergrund steht – vor allem die Gefährdungsbeurteilung und die daraus abgeleiteten Schutzmaßnahmen. KW - Arbeitsschutz KW - Technische Regeln für Betriebssicherheit KW - TRBS KW - Instandhaltung KW - Explosion KW - Tank PY - 2025 DO - https://doi.org/10.37307/j.2199-7349.2025.01.09 IS - 1 SP - 32 EP - 37 PB - Erich Schmidt Verlag (ESV) CY - Berlin AN - OPUS4-62380 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kärcher, Victor A1 - Reiker, Tobias A1 - da Costa, Pedro F.G.M. A1 - de Camargo, Andrea S.S. A1 - Zacharias, Helmut T1 - Quantum control in size selected semiconductor quantum dot thin films N2 - We introduce a novel technique for coherent control that employs resonant internally generated fields in CdTe quantum dot (QD) thin films at the L-point. The bulk band gap of CdTe at the L-point amounts to 3.6 eV, with the transition marked by strong Coulomb coupling. Third harmonic generation (λ3 = 343 nm, hν = 3.61 eV) for a fundamental wavelength of λ 1 = 1,030 nm is used to control quantum interference of three-photon resonant paths between the valence and conduction bands. Different thicknesses of the CdTe QDs are used to manipulate the phase relationship between the external fundamental and the internally generated third harmonic, resulting in either suppression or strong enhancement of the resonant third harmonic, while the nonresonant components remain nearly constant. This development could pave the way for new quantum interference–based applications in ultrafast switching of nanophotonic devices. KW - Nonlinear nanophotonics KW - Quantum interference KW - Third harmonic KW - Coherent control KW - Thin films KW - Quantum dots PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-625859 DO - https://doi.org/10.1515/nanoph-2024-0529 VL - 14 IS - 2 SP - 229 EP - 239 PB - Walter de Gruyter GmbH AN - OPUS4-62585 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Arai, Marylyn Setsuko A1 - Ravaro, Leandro Piaggi A1 - Brambilla, Gabriel A1 - Maia, Lauro June Queiroz A1 - Reza Dousti, Mohammad A1 - de Camargo, Andrea Simone Stucchi T1 - Upconverting Nanoparticles and Cu(I) Complex-Based Platform for Oxygen Sensing, Thermometry, and Emission Color Tuning N2 - Multifunctional nanoplatforms combine different material properties to meet a wide range of applications, allowing highly customizable systems. In this rapidly advancing research field, we introduce a multifunctional nanomaterial based on the synergy between Tm3+-doped upconverting nanoparticles (UCNPs) and a Cu(I) complex (CuCom). This material is designed for oxygen sensing, optical thermometry, and emission color tuning. In various concentrations, the CuCom complex was electrostatically integrated into a mesoporous silica shell surrounding the core UCNPs (UCNP@mSiO2). The optimized system, UCNP@mSiO2@CuCom-10, was evaluated for different applications. Due to the spectral overlap between the CuCom absorption and the nanoparticles emission, excitation at 980 nm allows most of the UV-blue emission output from the UCNPs to be transferred to the CuCom via luminescent resonance energy transfer (LRET), producing red emission from the molecule. The remaining Tm3+ emission enables optical thermometry, while CuCom’s sensitivity to molecular oxygen supports its application in gas sensing. In upconversion mode, the nanoplatform achieved a Stern−Volmer constant for O2 sensing of 1.64 and demonstrated thermometric relative sensitivities of 0.9% and 1% K−1 at room temperature, with a linear response from 193 to 373 K. Additionally, the emission color of UCNP@mSiO2@CuCom-10 can be tuned from blue to white and yellow, by varying the excitation and temperature, adding further functionality to the system. This multifunctional platform suggests promising applications in biology, medicine, and environmental monitoring. KW - M KW - O2 sensing KW - Upconversion KW - Luminescence resonance energy transfer (LRET) KW - Optical thermometry KW - Mesoporous silica shell PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-625869 SN - 2574-0970 DO - https://doi.org/10.1021/acsanm.4c06351 VL - 8 SP - 854 EP - 862 PB - American Chemical Society (ACS) AN - OPUS4-62586 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Veh, Georg A1 - Wang, Björn G. A1 - Zirzow, Anika A1 - Schmidt, Christoph A1 - Lützow, Natalie A1 - Steppat, Frederic A1 - Zhang, Guoqing A1 - Vogel, Kristin A1 - Geertsema, Marten A1 - Clague, John J. A1 - Korup, Oliver T1 - Progressively smaller glacier lake outburst floods despite worldwide growth in lake area N2 - Glacier lake outburst floods (GLOFs) may originate from larger lakes as these continue to grow with ongoing glacier retreat; however, this perception remains poorly supported in available GLOF databases. Here we mapped the areas of 1,686 glacier lakes, just before they drained, across 13 glaciated mountain regions outside polar regions and examined the trends in pre-GLOF lake areas between 1990 and 2023. We found that pre-GLOF lake areas barely changed, or even decreased, regionally through time, even as the total lake area, and thus hazard potential, grew overall. This counterintuitive finding reflects limits to growing GLOF magnitudes, such as the decoupling of lakes and parent glaciers, the development of wide, low-gradient outlets or human management. Across all regions, pre-GLOF lake areas depend on a few ice-dammed lakes, which have produced ten times more reported outbursts and ten times larger outbursts than moraineand bedrock-dammed lakes. The latter two dam types will continue to impound growing amounts of meltwater, thereby accounting for most of the overall GLOF hazard potential, while ice-dammed lakes will shrink with deglaciation. As these lake types will evolve differently in the twenty-first century, we call for customized simulations of GLOF outflows and impacts, given the growing exposure of critical infrastructure. KW - Climate change KW - Bayesian hierachical modelling KW - Outbursts flood PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-625709 DO - https://doi.org/10.1038/s44221-025-00388-w SN - 2731-6084 SP - 1 EP - 25 AN - OPUS4-62570 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Franz, Mathias A1 - Armitage, Sophie A.O. A1 - McMahon, Dino Peter A1 - Subasi, Bengisu S. A1 - Rafaluk, Charlotte T1 - Trade-offs in virulence evolution: a Hierarchy-of-Hypotheses approach N2 - Understanding the evolution of virulence, that is, the harm pathogens cause their hosts, has major and wide-spread repercussions. A central concept of virulence evolution is the so-called ‘trade-off hypothesis’, a seemingly straightforward relationship between virulence and transmission. However, substantial ambiguity in terminology related to this hypothesis threatens progress in the field. To address this, we apply a Hierarchy-of-Hypotheses approach to provide structured, visual representations of ideas linked to this hypothesis. We illustrate that the trade-off hypothesis is a complex set of many different hypotheses and trade-offs, and we clarify ambiguities and biases in commonly used terminology in the literature. Thereby, we hope to facilitate a more precise understanding of what the trade-off hypothesis means, enabling more targeted and precise hypothesis testing. KW - Pathogen virulence KW - Trade-off KW - Trade-off hypothesis KW - Virulence evolution PY - 2025 DO - https://doi.org/10.1016/j.pt.2025.01.006 SN - 1471-5007 VL - 41 IS - 3 SP - 188 EP - 195 PB - Elsevier Ltd. AN - OPUS4-62620 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Duarte, Larissa A1 - Madia, Mauro A1 - Kanna, Naveen A1 - Bär, Jürgen ED - Ricoeur, Andreas T1 - Anwendung der zyklischen R-Kurven-Analyse zur Abschätzung des Kitagawa-Takahashi-Diagramms N2 - Die ausgeprägte Langzeitfestigkeit eines Werkstoffes entspricht der maximalen Spannung, unterhalb derer alle ursprünglich wachstumsfähigen Mikrorisse arretieren. Für fehlerbehaftete Werkstoffe stellt das Kitagawa-Takahashi (KT)-Diagramm die Abhängigkeit der ausgeprägten Langzeitfestigkeit von der Defektgröße dar. Das KT-Diagramm kann mit großem Aufwand experimentell bestimmt oder durch verschiedene Modelle abgeschätzt werden. Solche Ansätze ergeben oft nichtkonservative Prognosen und berücksichtigen weder den Aufbau der Rissschließeffekte noch lokale Spannungen. In dieser Arbeit wird ein Kurzrissmodell auf Grundlage der zyklischen R-Kurve und des Rissarrestphänomens zur Abschätzung des KT-Diagramms vorgestellt. Die Abschätzungen werden mit experimentellen Daten validiert, die mit gekerbten Proben nach dem Treppenstufenverfahren ermittelt wurden. T2 - 57. Tagung des DVM-Arbeitskreises Bruchmechanik und Bauteilsicherheit CY - Köln, Germany DA - 18.02.2025 KW - Langzeitfestigkeit KW - KT-Diagramm KW - zyklische R-Kurven-Analyse PY - 2025 DO - https://doi.org/10.48447/BR-2025-512 VL - 257 SP - 93 EP - 104 PB - Deutscher Verband für Materialforschung und -prüfung e.V. CY - Berlin, Deutschland AN - OPUS4-62603 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CHAP A1 - Casperson, Ralf A1 - Leinenbach, F. A1 - Martin, J. ED - Meyendorf, N. ED - Ida, N. ED - Singh, R. ED - Vrana, J. T1 - DICONDE: Enabling FAIR Data and Communication in NDE 4.0 N2 - For the digital transformation and the integration of NDE into the Industry 4.0, standardized data formats and communication interfaces are mandatory. The Standard Practice for Digital Imaging and Communication in Nondestructive Evaluation (DICONDE), based on Digital Imaging and Communication in Medicine (DICOM), offers both a standardized data format and standardized communication interfaces. Furthermore, DICONDE meets the requirements of the EU Data Act by supporting the FAIR data principle (findable, accessible, interoperable, and reusable data). DICONDE standards are available for radiography including computed tomography, ultrasonic, and eddy current testing. Standards for thermography and secondary capture are under development. The basic concept of DICONDE, storage of eddy current and ultrasonic raw data, and the use case of railway rail inspection at the AIFRI project are discussed in detail. KW - Data format KW - Data communication KW - FAIR data KW - NDE 4.0 KW - Industry 4.0 KW - EU Data Act KW - DICONDE PY - 2025 SN - 978-3-030-48200-8 DO - https://doi.org/10.1007/978-3-030-48200-8 SP - 1 EP - 20 PB - Springer Nature CY - Heidelberg ET - 2 AN - OPUS4-62657 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Valentini, Martino A1 - De Almeida, Olivier A1 - Kakkonen, Markus A1 - Kalinka, Gerhard A1 - Dorigato, Andrea A1 - Kallio, Pasi A1 - Fredi, Giulia T1 - Effect of fiber surface state on the thermomechanical and interfacial properties of in situ polymerized polyamide 6/basalt fiber composites N2 - This study investigates the thermomechanical properties and interfacial adhesion of novel in-situ polymerized anionic polyamide 6 (aPA6) composites reinforced with basalt fibers (BF). The impact of different BF surface states - as-received (BFa), ethanol-washed (BFw), and thermally desized (BFu) on composite performance is examined through a comprehensive approach. For the first time, anionic PA6/BF composites with very low residual monomer content were successfully produced via thermoplastic resin transfer molding (tRTM). The PA6/BFw composites exhibited the highest interlaminar/interfacial shear strength in short beam shear test (52 ±8 MPa) and fiber push out test (34 ± 11 MPa) tests. Fiber microdebonding test, performed only on PA6/BFw, yielded a low interfacial shear strength (12 ± 4 MPa), which was attributed to droplet porosity resulting from concurrent polymerization and crystallization. Thermal desizing significantly deteriorated interfacial strength (19.6 ± 1.2 MPa in short beam shear test). This multi-technique characterization provides insights into optimizing the fiber–matrix adhesion in these advanced thermoplastic composites. KW - Anionic Polyamide 6 KW - Reactive thermoplastics KW - Basalt fibers KW - Microdebonding KW - Fiber push out KW - Short beam shear test PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-623596 DO - https://doi.org/10.1016/j.compositesa.2024.108681 SN - 1878-5840 VL - 190 SP - 1 EP - 15 PB - Elsevier Ltd. CY - Niederlande AN - OPUS4-62359 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kozachynskyi, Volodymyr A1 - Hoffmann, Christian A1 - Esche, Erik T1 - Why fixing alpha in the NRTL model might be a bad idea – Identifiability analysis of binary vapor-liquid equilibria N2 - New vapor-liquid equilibrium (VLE) data are continuously being measured and new parameter values, e.g., for the nonrandom two-liquid (NRTL) model are estimated and published. The parameter α, the nonrandomness parameter of NRTL, is often not estimated but is heuristically fixed to a constant value based on the involved components. This can be seen as a manual application of a (subset selection) regularization method. In this work, the practical parameter identifiability of the NRTL model for describing the VLE is analyzed. It is shown that fixing α is not always a good decision and sometimes leads to worse prediction properties of the final parameter estimates. Popular regularization techniques are compared and Generalized Orthogonalization is proposed as an alternative to this heuristic. In addition, the sequential Optimal Experimental Design and Parameter Estimation (sOED-PE) method is applied to study the influence of the regularization methods on the performance of the sOED-PE loop. KW - NRTL KW - VLE KW - Nonlinear programming KW - Model-based optimal experimental design PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-623605 DO - https://doi.org/10.1016/j.ces.2024.121122 VL - 305 SP - 1 EP - 18 PB - Elsevier Ltd. AN - OPUS4-62360 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Cunningham, Patrick A1 - Wang, L. A1 - Kane, S. A1 - Kim, A. A1 - Jenkins, B. M. A1 - Miller, S. A. T1 - Lifecycle implications and mechanical properties of carbonated biomass ashes as carbon-storing supplementary cementitious materials N2 - Methods to sequester and store atmospheric CO2 are critical to combat climate change. Alkaline-rich bioashes are potential carbon fixing materials. This work investigates potential co-benefits from mineralizing carbon in biomass ashes and partially replacing high embodied greenhouse gas (GHG) Portland cement (PC) in cement-based materials with these ashes. Specifically, rice hull ash (RHA), wheat straw ash (WSA), and sugarcane bagasse ash (SBA) were treated to mineralize carbon, and their experimental carbon content was compared to modeled potential carbonation. To understand changes in the cement-based storage materials, mortars made with CO2-treated WSA and RHA were experimentally compared to PC-only mortars and mortars made with ashes without prior CO2 treatment. Life cycle assessment methodology was applied to understand potential reductions in GHG emissions. The modeled carbonation was ∼18 g-CO2/kg-RHA and ∼180 g-CO2/kg-WSA. Ashes oxidized at 500 °C had the largest measured carbon content (5.4 g-carbon/kg-RHA and 35.3 g-carbon/kg-WSA). This carbon appeared to be predominantly residual from the biomass. Isothermal calorimetry showed RHA-PC pastes had similar heat of hydration to PC-pastes, while WSA-PC pastes exhibited an early (at ∼1.5 min) endothermic dip. Mortars with 5 % and 15 % RHA replacement had 1–12 % higher compressive strength at 28 days than PC-only mortars, and milled WSA mortars with 5 % replacement had 3 % higher strength. A loss in strength was noted for the milled 15 % WSA, the CO2-treated 5 %, and the 15 % WSA mortars. Modeled reductions in GHG emissions from CO2-treated ashes were, however, marginal (<1 %) relative to the untreated ashes. KW - CO2 sequestration KW - CO2 storage KW - Biomass ash KW - Supplementary cementitious materials KW - Concrete PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-626959 DO - https://doi.org/10.1016/j.biombioe.2025.107772 SN - 1873-2909 VL - 197 SP - 1 EP - 13 PB - Elsevier CY - Amsterdam AN - OPUS4-62695 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Asante, Bright T1 - Optimized mix design and fire resistance of geopolymer recycled aggregate concrete under elevated temperatures N2 - This study investigates the performance of fly ash-based geopolymer recycled aggregate concrete (GRAC) as a sustainable alternative to Ordinary Portland Cement (OPC) concrete, focusing on its compressive strength and behavior under high-temperature exposure (150 ◦C, 300 ◦C, 600 ◦C, and 900 ◦C). The research emphasizes the use of 100 % recycled concrete aggregates as a replacement for natural aggregates, with samples cured at ambient conditions and at 60 ◦C in an oven. Key factors, including water content and curing conditions, were evaluated to determine their influence on compressive strength and thermal stability. Results indicate that water content is the primary factor governing compressive strength, while recycled aggregates contribute to a secondary but notable effect. GRAC maintained up to 65 % of its initial strength after exposure to 600 ◦C, though strength degradation and severe cracking occurred at 900 ◦C. Oven-cured samples showed fewer surface cracks but experienced slightly higher mass loss than room-cured coun-terparts. This study highlights the potential of GRAC as an environmentally friendly material capable of withstanding moderate thermal conditions, providing significant contributions to green construction practices and the reuse of construction and demolition waste. KW - Geopolymer KW - Recycled aggregate concrete KW - Elevated temperature PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-627071 DO - https://doi.org/10.1016/j.cscm.2025.e04401 SN - 2214-5095 VL - 22 SP - 1 EP - 17 PB - Elsevier Ltd. AN - OPUS4-62707 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CHAP A1 - Vogel, Christian A1 - Slee, D. ED - Naidu, R. T1 - Chapter 5 Analytical techniques for Per- and Polyfluoroalkyl substances (PFAS) N2 - Per- and polyfluoroalkyl substances (PFAS) are a group of various anthropogenic organic products, in which the hydrogen atoms on the carbon skeleton of at least one carbon atom have been completely replaced by fluorine atoms. Because this group contains more than 7 million compounds, they can have very different properties. PFAS analysis in environmental samples is currently mainly utilized by liquid chromatography-tandem mass spectrometry (LC-MS/MS) and related techniques as well as gas chromatography-mass spectrometry (GC-MS) to conduct target analysis. However, to get a better overview of the amount of “total” amount of PFAS, sum parameter methods like total oxidizable precursor assay (TOPA), absorbable organic fluorine (AOF), and extractable organic fluorine (EOF) are in development. Additionally, for research purposes, several spectroscopical methods like X-ray photoelectron spectroscopy (XPS), fluorine K-edge X-ray absorption near-edge structure (XANES) spectroscopy, particular induced gamma-ray emission (PIGE) spectroscopy as well as19 F nuclear magnetic resonance (NMR), infrared, and Raman spectroscopy are available. Therefore, an overview is given on currently available analytical techniques for PFAS in environmental samples and their application possibilities discussed for different kinds of PFAS subgroups. KW - Per- and polyfluoroalkyl substances (PFAS) KW - Analytics KW - Liquid chromatography - mass spectrometry (GC-MS) KW - Sum parameter PY - 2025 DO - https://doi.org/10.1515/9783110796797-005 SP - 143 EP - 168 PB - De Gruyter AN - OPUS4-62662 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Dolai, Malay A1 - Saha, Urmila A1 - Goswami, Juli Nanda A1 - Bhattacharya, Biswajit A1 - Emmerling, Franziska A1 - Ifseisi, Ahmad A. A1 - Biswas, Surajit ED - Bhattacharya, Biswajit T1 - Nickel(II)-mediated in situ complex formation with unexpected ligand transformations: crystal structures, DFT calculations, and catalytic activity in CO2 fixation reactions N2 - Two transformed ligands, namely 1,3,5-triazapentadienato(imidoylamidinato) and N-(methoxy(pyrimidin-2-yl)(pyrimidine-2-carboxamido)methyl)pyrimidine-2-carboxamide, are reported here as the first products derived from 2-cyano pyridine/pyrimidine, respectively, under nickel metal mediation in the presence of hydroxylamine hydrochloride in situ. Two different nickel-coordinated complexes (1 and 2) were formed. Single crystal X-ray diffraction revealed that complex 1 is a mononuclear complex with tetra-coordinated square planar geometry, whereas complex 2 is a dinuclear complex with hexa-coordinated distorted octahedral geometry. The synthetic pathways of both transformed ligands are explained with the support of energy calculations of different states via density functional theory (DFT) calculations. The catalytic addition reactions of epoxides and carbon dioxide efficiently produce organic cyclic carbonates in the presence of complexes 1–2, attributed to the presence of Lewis acidic nickel and Lewis basic centers, such as free amine, imine, methoxy, or nitrogen in complexes 1 and 2. Under mild reaction conditions (1 atm CO2 pressure and 60 °C temperature), different types of epoxides (exocyclic, endocyclic, and aromatic epoxides) yield high levels of respective cyclic carbonates in the presence of both complexes 1–2 as catalysts, with tert-butylammonium bromide (TBAB) acting as a co-catalyst. The high turnover number (TON) and turnover frequency (TOF) of these catalytic reactions clearly indicate the efficacy of the two catalysts. KW - Catalytic activity in CO2 fixation reactions DFT calculations KW - Nickel(II)-complex KW - In situ complex formation KW - Crystal Structure PY - 2025 DO - https://doi.org/10.1039/d4nj01801j SN - 1369-9261 VL - 49 IS - 11 SP - 4451 EP - 4463 PB - Royal Society of Chemistry (RSC) AN - OPUS4-62782 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - McNeil, Sue A1 - Adey, Bryan A1 - Anastasopoulos, Panagiotis Ch. A1 - Chu, James C. A1 - Derrible, Sybil A1 - Durango-Cohen, Pablo A1 - Francis, Royce A1 - Kruschwitz, Sabine A1 - Labi, Samuel A1 - Li, Joshua A1 - Manuel, Lance A1 - Cunha Marques, Rui A1 - Reilly, Allison A1 - Tesfamariam, Solomon A1 - Sanford, Kristen L. T1 - Journal of Infrastructure Systems: Thirty Years and an Opportunity to Refocus N2 - The editorial reflects on the 30-year journey of the Journal of Infrastructure Systems, highlighting its evolution, interdisciplinary mission, and contributions to the field of civil infrastructure. It traces the journal's history, including the introduction of new paper formats, awards, and its commitment to engaging early-career professionals. Looking forward, the journal emphasizes its focus on complex, system-level challenges, encouraging submissions that integrate engineering with data-driven, cross-disciplinary approaches, particularly in areas like smart infrastructure, climate resilience, and sustainability. The editorial concludes with gratitude to contributors and a call for continued collaboration to advance the understanding and management of infrastructure systems. KW - Maintenance KW - Infrastructure systen KW - Transportation KW - Repair KW - Climate resilience KW - Refurbishment PY - 2025 DO - https://doi.org/10.1061/JITSE4.ISENG-2690 VL - 31 IS - 1 SP - 1 EP - 2 PB - American Society of Civil Engineers (ASCE) AN - OPUS4-62773 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Spindlegger, Anna A1 - Slotyuk, Lyubov A1 - Jandric, Aleksander A1 - De Souza, Ricardo Gabbay A1 - Prenner, Stefanie A1 - Part, Florian T1 - Environmental performance of second-life lithium-ion batteries repurposed from electric vehicles for household storage systems N2 - Repurposing lithium-ion batteries has proven to be a promising solution to address the rising number of end-of-life batteries that can be used for second-life energy storage systems and thus extend their service life. While previous research has provided valuable insights into the environmental benefits of battery repurposing, there is still a need to examine the repurposing process more thoroughly, in order to make well-informed decisions on the implementation of second-life battery storage systems. Therefore, this study examines the influence of different repurposing strategies on the environmental performance of second-life battery energy storage systems. A life cycle assessment was conducted, analysing four repurposing cases relating to the exchange of components, namely i) new battery management system and module casing (Base case), ii) new battery management system and reuse of module casing (Case 1), iii) new module casing and reuse of battery management system (Case 2) and iv) reuse of module casing and battery management system (Case 3). These impacts were compared to a storage system with new batteries, to determine the potential environmental benefits and identify the most suitable repurposing strategy. Our findings demonstrate significant environmental benefits of second-life battery energy storage systems across various impact categories and repurposing cases. The Base case and Case 1 resulted in environmental benefits across all impact categories. The highest benefits were observed for metal depletion with savings of 58 % and 61 %, respectively. Increased savings were obtained for Case 2 and Case 3. However, environmental drawbacks were identified for freshwater and marine ecotoxicity. In particular, Case 2 resulted in the highest drawbacks of -22 % and -16 %, respectively. These can be attributed to the allocation procedure, particularly affecting the recycling credits of battery management system recycling. The full allocation of end-of-life impacts and consequently the recycling credits to the second-life battery has not only led to a substantial increase in overall savings, but also resulted in impact categories that originally had disadvantages becoming those with the highest environmental savings. This study demonstrates the importance of carefully selecting repurposing strategies for second-life energy storage systems to maximize their environmental benefits and avoid drawbacks. Additionally, the results highlight the substantial influence of allocation procedures on overall environmental impacts, underscoring the need for clearer methodological guidance on addressing the multifunctionality of repurposed batteries. KW - Life cycle assessment KW - Repurposing KW - Second-life battery KW - Lithium-ion battery KW - Battery energy storage system KW - Circular economy PY - 2025 DO - https://doi.org/10.1016/j.spc.2025.01.003 SN - 2352-5509 VL - 54 SP - 227 EP - 240 PB - Elsevier CY - Amsterdam AN - OPUS4-62940 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Dorszewski, C. A1 - Dieckmann, J. A1 - Balaresque, N. A1 - Krankenhagen, Rainer A1 - von Freyberg, A. A1 - Fischer, A. T1 - Corrigendum: Weather-dependency of the thermographic flow visualization of the laminar-turbulent transition on wind turbines (2024 Meas. Sci. Technol. 35 095301) N2 - The authors have received additional information from material experts regarding some assumptions made in the article in section 2.2 concerning the heat transfer. Based on the resulting discussion, the corrigendum aims to complement, contextualize and emphasize certain points of the article. PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-630226 DO - https://doi.org/10.1088/1361-6501/adc14b SN - 1361-6501 N1 - Das Corrigendum ergab sich als Ergebnis einer fachlichen Diskussion unter Beteiligung der BAM über Mängel des Artikels. Bei der Erstellung der ursprünglichen Publikation war die BAM nicht involviert. - The corrigendum resulted from a technical discussion involving BAM regarding deficiencies in the article. BAM was not involved in the preparation of the original publication. VL - 36 SP - 1 EP - 2 PB - IOP Science CY - Bristol AN - OPUS4-63022 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Paul, Nathalie A1 - Kister, Alexander A1 - Schnellhardt, Thorben A1 - Fetz, Maximilian A1 - Hecker, Dirk A1 - Wirtz, Tim ED - Meo, Rosa ED - Silvestri, Fabrizio T1 - Reinforcement Learning for Segmented Manufacturing N2 - The manufacturing of large components is, in comparison to small components, cost intensive. This is due to the sheer size of the components and the limited scalability in number of produced items. To take advantage of the effects of small component production we segment the large components into smaller parts and schedule the production of these parts on regular-sized machine tools. We propose to apply and adapt recent developments in reinforcement learning in combination with heuristics to efficiently solve the resulting segmentation and assignment problem. In particular, we solve the assignment problem up to a factor of 8 faster and only a few percentages less accurate than a classic solver from operations research. T2 - European Conference on Machine Learning and Principles and Practice of Knowledge Discovery in Databases 2023 CY - Turin, Italy DA - 18.09.2023 KW - Reinforcement Learning KW - Assignment Problem KW - Large component manufacturing PY - 2025 DO - https://doi.org/10.1007/978-3-031-74640-6_38 VL - 1 IS - 1 SP - 470 EP - 485 PB - Springer Cham AN - OPUS4-63031 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Reigl, Selina A1 - Van Driessche, Alexander A1 - Stawski, Tomasz A1 - Koltzenburg, Sebastian A1 - Kunz, Werner A1 - Kellermeier, Matthias T1 - Sustainable Pathways for the Synthesis of Calcium Sulfate Hemihydrate N2 - Calcium sulfate, and especially its hemihydrate form (bassanite), is crucial in the construction industry, primarily used as a hydraulic binder in cements, mortars, and wallboards. Because of the rapid transformation of bassanite into thermodynamically stable gypsum (calcium sulfate dihydrate) upon contact with water, natural deposits are scarce, rendering it one of the most extensively produced inorganic materials worldwide. Currently, bassanite is derived from mined or waste gypsum through a thermal dehydration process, which is energy-intensive and costly. As sustainability has become a key target for industrial processes and products, a series of studies aiming to increase the energy efficiency and reduce the carbon footprint of bassanite production was published recently. Two primary approaches are pursued: conversion of gypsum and direct precipitation of bassanite from solution. In both cases, organic solvents, (specific) additives and/or elevated temperatures have been used to control the activity/availability of water in the reaction medium and thus direct phase selection towards bassanite. This review offers a comprehensive overview of alternative bassanite production methods, critically examining their benefits, potential downsides, and overall impact on the sustainability of industrial-scale use. KW - Calcium sulfate KW - Gypsum KW - Bassanite KW - Recycling PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-630657 DO - https://doi.org/10.1002/anie.202415161 SN - 1521-3773 SP - 1 EP - 20 PB - Wiley VHC-Verlag AN - OPUS4-63065 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Zöllner, Moritz T. A1 - Dariz, Petra A1 - Riedel, Jens A1 - Schmid, Thomas T1 - Dolomite and Mg Calcite as Mineral Thermometers in Mortar Binders. A High Resolution Raman Spectroscopic Study N2 - This paper suggests the use of high‐resolution Raman scattering bands of MgCa carbonates as posteriori thermometer minerals in archaeometric studies. Therefore, the thermal behavior of two dolomite samples and the hydration and carbonation reaction in air of the decomposition products were investigated by Raman microspectroscopy. The increase in the calcination temperature resulted in the formation of – Raman silent MgO and – inert Mg calcite at 700°C–750°C. In contrast, the decarbonation, hydration, and recarbonation of sample material exposed to 750°C–900°C in a muffle furnace led to the appearance of Mg‐free calcite. High spectral resolution Raman spectroscopy enabled a spectral distinction between these two groups due to differences in the band parameters (peak position, bandwidth) of the vibrational (v1, v4, L) modes of calcite. In combination with Raman microspectroscopic mapping, this spectral information represents a new approach for the estimation of burning temperatures of medieval high‐fired gypsum mortars via natural dolomite impurities. Thus, the results of this work highlight the importance and potential of Raman microspectroscopy as a thermometric tool for elucidating the thermal history of anthropogenic fired materials, with potential applications for archaeometry and art technology, as well as for quality controls in the frame of the production of mineral mortar binders and ceramics or bricks, respectively. KW - Mineral thermometry KW - Raman spectroscopy KW - Dolomite KW - High-fired gypsum mortar PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-630270 DO - https://doi.org/10.1002/jrs.6810 SN - 1097-4555 SP - 1 EP - 13 PB - Wiley AN - OPUS4-63027 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Liehr, Alexander A1 - Dingel, Kristina A1 - Kottke, Daniel A1 - Degener, Sebastian A1 - Meier, David A1 - Sick, Bernhard A1 - Niendorf, Thomas T1 - Data selection strategies for minimizing measurement time in materials characterization N2 - Every new material needs to be assessed and qualified for an envisaged application. A steadily increasing number of new alloys, designed to address challenges in terms of reliability and sustainability, poses significant demands on well-known analysis methods in terms of their efficiency, e.g., in X-ray diffraction analysis. Particularly in laboratory measurements, where the intensities in diffraction experiments tend to be low, a possibility to adapt the exposure time to the prevailing boundary conditions, i.e., the investigated microstructure, is seen to be a very effective approach. The counting time is decisive for, e.g., complex texture, phase, and residual stress measurements. Traditionally, more measurement points and, thus, longer data collection times lead to more accurate information. Here, too short counting times result in poor signal-to-background ratios and dominant signal noise, respectively, rendering subsequent evaluation more difficult or even impossible. Then, it is necessary to repeat experiments with adjusted, usually significantly longer counting time. To prevent redundant measurements, it is state-of-the-art to always consider the entire measurement range, regardless of whether the investigated points are relevant and contribute to the subsequent materials characterization, respectively. Obviously, this kind of approach is extremely time-consuming and, eventually, not efficient. The present study highlights that specific selection strategies, taking into account the prevailing microstructure of the alloy in focus, can decrease counting times in X-ray energy dispersive diffraction experiments without any detrimental effect on data quality for the subsequent analysis. All relevant data, including the code, are carefully assessed and will be the basis for a widely adapted strategy enabling efficient measurements not only in lab environments but also in large-scale facilities. KW - Materials characterization KW - Machine learning KW - X-ray diffraction KW - Measurement optimization PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-630831 DO - https://doi.org/10.1038/s41598-025-96221-1 SN - 2045-2322 VL - 15 IS - 1 SP - 1 EP - 12 PB - Springer Science and Business Media LLC AN - OPUS4-63083 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Strauß, Lea A1 - Duarte, Larissa A1 - Kruse, Julius A1 - Madia, Mauro A1 - Löwisch, Günther T1 - An equivalent stress approach for predicting fatigue behavior of additively manufactured AlSi10Mg N2 - Laser-based powder bed fusion (PBF-LB) is an advanced additive manufacturing technique renowned for its precision and capability to fabricate complex metal components. However, the high thermal gradients and rapid cooling rates intrinsic to this process introduce significant process-induced effects, such as inhomogeneities, surface roughness, anisotropy, and residual stress, all of which critically influence the fatigue behavior of the produced parts. This study investigates the fatigue performance of AlSi10Mg samples produced by PBF-LB, examining the impact of varying surface conditions, geometries, and residual stress levels. Fatigue-life prediction models are formulated based on nominal stress amplitude, residual stress, form factor, crack-initiating inhomogeneity, and surface roughness, with smooth samples serving as a baseline reference. The study presents two empirical models for predicting fatigue life and fatigue strength using S–N curves and the Kitagawa–Takahashi diagram with the El Haddad approach, derived from comprehensive experimental data, including finite element modeling, fatigue-life measurements, surface roughness evaluations, and residual stress analysis. KW - AlSi10Mg KW - Kitagawa–Takahashi diagram KW - El Haddad KW - Equivalent stress KW - Fatigue-life prediction KW - PBF-LB/M PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-625176 DO - https://doi.org/10.1007/s40964-025-00974-0 SP - 1 EP - 16 PB - Springer Science and Business Media LLC AN - OPUS4-62517 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CHAP A1 - Loose, Florian ED - Thiel, S. ED - Thomé-Kozmiensky, E. ED - Quicker, P. ED - Gosten, A. ED - Stengler, E. T1 - Carbonfaserhaltige Reststoffe als Sekundärrohstoff – Einsatz in der Pyrometallurgie N2 - Für die Bewältigung der Herausforderungen des 21. Jahrhunderts, insbesondere des Klimawandel ist der Leichtbau eine Schlüsseltechnologie. Leichtbau trägt zur Reduzierung von CO2-Emissionen bei, verbessert die Ressourceneffizienz und unterstützt die Mobilitätswende. Insbesondere Carbonfasern (CF) und carbonfaserverstärkte Kunststoffe (CFK) spielen eine zentrale Rolle in verschiedenen Industriezweigen wie Luftfahrt, Windkraft und Elektromobilität. Mit der steigenden Nachfrage wachsen auch die Reststoffströme von CF, deren Recycling entscheidend für die Umweltverträglichkeit und die Kreislaufwirtschaft ist. Die Schwierigkeit des CF-Recyclings bestehen darin, die CF von der Kunststoffmatrix zu trennen, um hochwertige Recyclingmaterialien zu gewinnen. Verfahren wie Solvolyse und Pyrolyse werden genutzt, wobei überwiegend die Pyrolyse umgesetzt wird. Der Prozess zur Gewinnung von Recycling-Carbonfasern (rCF) hat jedoch auch Nachteile, da die Faserlängen und -qualitäten durch Recyclingprozesse beeinträchtigt werden können. Sicherheitsaspekte sind ebenfalls wichtig, da CF Bruchstücke potenziell gesundheitsschädlich sein können. Zur Behandlung von CF-Abfallströmen müssen Verfahren entwickelt werden, die eine sichere Verwertung ermöglichen, da Deponierung aufgrund der Kunststoffmatrix nicht möglich ist. Großversuche haben gezeigt, dass die thermische Verwertung von CF in Müllverbrennungsanlagen unvollständig ist, was auf die chemische Struktur von CF zurückzuführen ist. Die pyrometallurgische Nutzung von CF wird als vielversprechender Ansatz betrachtet. Hierbei können CF in diesen Hochtemperaturprozessen chemisch so genutzt werden, dass ihre Umwandlung verbessert und gleichzeitig die Bildung gesundheitsschädlicher Fragmente minimiert ist. In diesem Zusammenhang sind Studien zur Reaktivität von CF in solchen Prozessen wichtig, um die Effizienz und Sicherheit der Verfahren zu überprüfen. Zusammenfassend lässt sich sagen, dass die sichere und effiziente Nutzung von CF-Abfällen nicht nur zur Kreislaufwirtschaft beiträgt, sondern auch die Dekarbonisierung der Stahlindustrie vorantreibt. Es ist entscheidend, geeignete Prozesse zu entwickeln, um die Umwelt und die Gesundheit der Arbeiter zu schützen und gleichzeitig die Wertschöpfung aus CF-Reststoffen zu erhalten. KW - Leichtbau KW - Carbonfasern KW - Recycling KW - Secondary Resource KW - Pyrometallurgy PY - 2025 SN - 978-3-911006-85-9 VL - 2 SP - 527 EP - 540 PB - Thomé-Kozmiensky Verlag CY - Neuruppin AN - OPUS4-62463 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Omar, Hassan A1 - Ahmadi, Shayan A1 - Szymoniak, Paulina A1 - Schönhals, Andreas T1 - Molecular Mobility of Thin Films of Poly (bisphenol-A carbonate) Capped and with one Free Surface: From Bulk-like Samples down to the Adsorbed Layer N2 - The molecular mobility of thin films of poly(bisphenol A carbonate) (PBAC) was systematically investigated using broadband dielectric spectroscopy, employing two distinct electrode configurations. First, films were prepared in a capped geometry between aluminum electrodes employing a crossed electrode capacitor (CEC) configuration, down to film thicknesses of 40 nm. The Vogel temperature, derived from the temperature dependence of relaxation rate of the α-relaxation, increases with decreasing film thickness characterized by an onset thickness. The onset thickness depends on the annealing conditions, with less intense annealing yielding a lower onset thickness. Additionally, a broadening of the β-relaxation peak was observed with decreasing thickness, attributed to the interaction of phenyl groups with thermally evaporated aluminum, resulting in a shift of certain relaxation modes to higher temperatures relative to the bulk material. A novel phenomenon, termed the slow Arrhenius process (SAP), was also identified in proximity to the α-relaxation temperature. For films with thicknesses below 40 nm, nanostructured electrodes (NSE) were utilized, incorporating nanostructured silica spacers to establish a free surface with air. This free surface causes an enhancement in the molecular mobility for the 40 nm sample, preserving the β-relaxation as a distinct peak. The α-relaxation was detectable in the dielectric loss down to 18 nm, shifting to higher temperatures as film thickness is decreased. Notably, the onset thickness for the increase in Vogel temperature was lower in the NSE configuration compared to the CEC setup, attributed to the presence of the polymer-air interface. KW - Thin polymer films PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-623422 DO - https://doi.org/10.1039/d4sm01238k SN - 1744-6848 VL - 21 IS - 2 SP - 241 EP - 254 PB - RSC AN - OPUS4-62342 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Liao, Chun-Man ED - Zhang, Jian T1 - Modal and Wave Propagation Analysis of Vibration Tests on a Laboratory Building Model Before and After Damage N2 - Weakened structural stiffness is often a consequence of building damage, particularly after severe events such as earthquakes, where compromised structural performance can pose significant risks. To prevent immediate structural failure, an early warning system is essential, which requires inspection of local components. This research aims to achieve that by exploring the wave propagation analysis method, specifically seismic interferometry. Previous studies have applied this method to building structures, treating them as homogeneous layers of grouped floors. By analyzing the wave travel time along the height of these layers, the fundamental period of the building was estimated. However, this approach did not account for local damage or the variability of structural components, similar to the limitations of vibration‐based damage detection methods, which mainly identify global changes. Thus, the goal of this paper is to improve structural health monitoring by examining the sensitivity of wave screening, bridging the gap between nondestructive testing and vibration‐based damage detection. A half‐scale, seven‐story building model, characterized by vertical stiffness irregularity and transverse plan asymmetry, was tested in a laboratory setting. Two vertical sensor arrays were placed near corner columns of different sizes, representing both strong and weak structural areas. These arrays recorded floor accelerations in three directions. The study confirmed the effectiveness of wave propagation analysis for detecting damage along the sensor arrays before and after the earthquake. A transmissibility damage indicator was used to correlate changes in wave velocity, providing a quantitative assessment of damage levels along the wave propagation path. KW - Damage location KW - Laboratory test KW - Soft story KW - Stifness irregular structure KW - Structural health monitoring PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-624931 DO - https://doi.org/10.1155/stc/3453150 SN - 1545-2263 VL - 2025 IS - 1 SP - 1 EP - 17 PB - John Wiley & Sons Ltd. AN - OPUS4-62493 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Nagel, Thomas A1 - Rühaak, Wolfram A1 - Amann, Florian A1 - Bracke, Guido A1 - Buske, Stefan A1 - Kowalski, Julia A1 - Reiche, Sönke A1 - Schäfer, Thorsten A1 - Scheytt, Traugott A1 - Stumpf, Thorsten A1 - Völzke, Holger A1 - Wellmann, Florian A1 - Kolditz, Olaf T1 - Deep geological disposal - Editorial to the topical collection N2 - The subsurface geological environment, historically a key source of fossil and mineral resources, has seen a significant broadening of its potential applications in recent years, with increasing emphasis on its use for energy production and storage. A critical factor in utilizing subsurface space is ensuring the sustainability of management practices, with particular attention to the potential environmental impacts that may result. The current Topical Collection on Deep Geological Disposal places greater emphasis on the geotechnical aspects of geological disposal, with a particular focus on the safe isolation of hazardous materials, including radioactive waste. The Topical Collection on Deep Geological Disposal covers both experimental (laboratory and in-situ) and theoretical studies of various geotechnical applications, such as geological disposal of radioactive or other materials, e.g. coal-based solid waste, carbon dioxide sequestration in fractured reservoirs, and brine solutions, but also aspects of uranium mining. The articles in the Topical Collections are arranged under the following headings: – Fundamental studies – Experimental studies – Numerical studies KW - Disposal KW - Radioactive Waste KW - Geology PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-624955 DO - https://doi.org/10.1007/s12665-024-12075-2 SN - 1866-6299 VL - 84 IS - 3 SP - 1 EP - 6 PB - Springer Nature AN - OPUS4-62495 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Fürst, Richard A1 - Häßler, Dustin A1 - Stelzner, Ludwig A1 - Hothan, Sascha T1 - Fire resistance of existing steel structures with aged intumescent coating based on an in situ test method N2 - Intumescent coatings are commonly used in civil engineering to increase the fire resistance of steel structures. Exposed to fire, the intumescent coating reacts and forms a thermal protective char around the steel member. Thus, the heating of the steel is significantly slowed down and the fire resistance can be improved. Information regarding the scope of application and the durability of intumescent coatings are given in national approvals or European Technical Assessment documents. Due to the environmental conditions, intumescent coatings are subjected to ageing effects, which can reduce the durability and their thermal protection performance. To predict the durability for several years, during the approval procedure the behaviour of intumescent coatings is predominantly extrapolated based on accelerated artificial ageing. The established German and European assessment procedures to test and assess durability assume a working life of at least 10 years. Additional evidence may be required for longer periods. However, at present there is no method of verifying the thermal performance of existing structural members on site. For this reason, BAM is conducting the research project "INSIST" [1] to develop a minimally invasive in situ test method to determine the fire resistance of existing steel structures with applied intumescent coating. The investigation includes the development of a mobile prototype furnace. The paper describes the test setup, the developed prototype furnace, and the results of the performed test programme on uncoated and coated steel specimens. Based on this, recommendations for the test procedure are given. KW - In situ testing KW - Fire resistance KW - Intumescent coating KW - Steel KW - Thermal protection KW - Durability PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-629533 DO - https://doi.org/10.1016/j.firesaf.2025.104380 VL - 153 SP - 1 EP - 12 PB - Elsevier Ltd. AN - OPUS4-62953 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Ferrier, Emmanuel A1 - Michel, Laurent A1 - Thiele, Marc A1 - Mercier, Julien T1 - Strain-rate effect on the bond strength of external bonded reinforced carbon fiber-reinforced polymer for concrete structure N2 - The aim of the presented study is to investigate the dynamic loading strength of an external bonded fiber-reinforced polymers (FRP) system under seismic loading. 16 bonded FRP samples under different loading speeds ranging as 0.0000167–0.8 m /s were examined to determine the characteristics of the FRP bond strength on the concrete. The mechanical tests involved measuring the concrete/FRP shear properties using a double-lap shear test. Sixteen concrete specimens were cast, strengthened and surface preparation, instrumented, and driven to failure in the LMC laboratory and the BAM laboratory (Germany). Dynamic loading increased the bonded strength mainly because of an increase in the concrete tensile strength. Experimental data are then analysed and competed with the equation given by the new European standard that develop the design of external bonded FRP. The characteristic properties and bonded strength obtained by design equation were compared. Based on the results design equation are modified. KW - EBR strengthening system KW - Desing bond strength KW - Durability PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-625354 DO - https://doi.org/10.1016/j.conbuildmat.2025.140216 SN - 1879-0526 VL - 466 SP - 1 EP - 14 PB - Elsevier Ltd. AN - OPUS4-62535 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Pirskawetz, Stephan A1 - Zaripova, Gulshat A1 - Brinkmann, Nienke A1 - Gebraad, Lars A1 - Boehm, Christian A1 - Trattnig, Horst T1 - Simulation der Schallemissionen von Spanndrahtbrüchen N2 - In den 1950er Jahren setzte sich die Spannbetonbauweise für Brücken mit größeren Spannweiten durch. Heute existieren im deutschen Bundesfernstraßennetz ca. 21.000 Spannbetonbrücken. Die mangelnde Erfahrung in der Anfangszeit dieser Bauweise stellt uns heute vor Probleme hinsichtlich einer Kombination aus Korrosion und Ermüdung der Spannglieder. Hauptursachen sind Spannungsrisskorrosion, deutlich gewachsene Verkehrslasten sowie ungenügende Annahmen zu Temperaturlasten. Insbesondere Spanndrahtbrüche infolge Spannungsrisskorrosion können zu einem Strukturversagen ohne Ankündigung führen. Spannstähle mit einer starken Gefährdung für Spannungsrisskorrosion wurden in der Bundesrepublik bis 1965, in der ehemaligen DDR bis Ende der 1980er Jahre verbaut. Um katastrophale Schadensfälle zu verhindern, müssen Bauwerke unter Verdacht auf Spannungsrisskorrosion in Kombination mit unzureichendem Ankündigungsverhalten überwacht werden. Derzeit ist die Schallemissionsanalyse die einzige zuverlässige und ökonomisch vertretbare Überwachungsmethode. Damit kann der sichere Betrieb der Bauwerke über die verbleibende Nutzungsdauer gewährleistet werden. Die DGZfP-Richtlinie SE05 “Detektion von Spanndrahtbrüchen mit Schallemissionsanalyse” beschreibt detailliert Planung, Installation und Betrieb solcher Monitoringsysteme. Im Projekt SimAS “Digitaler Zwilling zur Simulation der Ausbreitung akustischer Wellen in Spannbetonelementen” werden die Grundlagen für eine Optimierung der Monitoringsysteme auf Basis der Schallemissionsanalyse gelegt. Eine akustische Simulation der Struktur und deren Fusion mit Messdaten unterstützt sowohl die vorbereitenden akustischen Analysen der Brücken als auch die Planung der Monitoringsysteme und die Drahtbrucherkennung T2 - SCHALL 25 – Schallemissionsanalyse und Zustandsüberwachung mit geführten Wellen CY - Dresden, Germany DA - 27.03.2025 KW - Acoustic Emission KW - Simulation KW - Schallemission KW - Spannbetonbrücke KW - Spanndrahtbruch KW - Digitaler akustischer Zwilling KW - Spannungsrisskorrosion KW - Schallemissionsanalyse KW - Schallausbreitung PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-628347 DO - https://doi.org/10.58286/30964 VL - 4 SP - 1 EP - 6 PB - Deutsche Gesellschaft für Zerstörungsfreie Prüfung AN - OPUS4-62834 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Weise, Frank A1 - Stelzner, Ludwig A1 - Recknagel, Christoph A1 - Pittrich, Tim A1 - Neugum, Tim A1 - Hering, Marcus A1 - Fiedler, Georg A1 - Thiele, Marc A1 - Simon, Patrick A1 - Maack, Stefan T1 - 63. DAfStb-Forschungskolloquium in der BAM - Themenblock 5: Bauteile und Bauwerke N2 - Ein weiterer Fokus des 63. DAfStb-Forschungskolloquiums (Tagungsband: DOI 10.26272/opus4-61338) lag auf den Bauteil- und Bauwerksuntersuchungen. Insbesondere wurde hier ein Einblick in die Forschungsaktivitäten in den BAM-Themenfeldern „Infrastruktur“ und „Energie“ gegeben. Thematisch wird dabei der Bogen von der Dauerhaftigkeit von Betonfahrbahndecken über die Extrembeanspruchung von Bauteilen und Bauwerken mittels Brand und Impact bis zum Bauwerksmonitoring und der Zustandsanalyse von Bestandsbauwerken gespannt. T2 - 11. Jahrestagung des DAfStb mit 63. Forschungskolloquium der BAM Green Intelligent Building CY - Berlin, Germany DA - 16.10.2024 KW - Dauerhaftigkeit von Betonfahrbahndecken KW - Alkali-Kieselsäurereaktion KW - Brand Impact KW - Bauwerksmonitoring PY - 2025 SN - 0005-9846 VL - 75 IS - 4 SP - 138 EP - 140 PB - concrete content UG CY - Schermbeck AN - OPUS4-63071 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Strangfeld, Christoph A1 - Müller-Vahl, H. F. A1 - Nayeri, C. N. A1 - Paschereit, C. O. A1 - Greenblatt, D. T1 - Airfoil synchronous surging and pitching N2 - Combined surging and pitching of an airfoil at the identical frequency (i.e. synchronously), at four different phase differences, was investigated theoretically and experimentally. The most general unsteady theoretical formulation was adopted to calculate the lift coefficient, and then extended to explicitly compute the unsteady bound vortex sheet. This was used for comparison with experiments and facilitated the computation of both Joukowsky and impulsive-pressure lift contributions. Experiments were performed using a symmetric 18 % thick airfoil in an unsteady wind tunnel at an average Reynolds number of 3.0*10^5 , with a free-stream oscillation amplitude of 51 %, an angle-of-attack range of 2° +- 2° and a reduced frequency of 0.097. In general, excellent correspondence was observed between theory and experiment, representing the first direct experimental validation of the general theory. It was shown, both theoretically and experimentally, that the lift coefficient was not accurately represented by independent superposition of surging and pitching effects, due to variations in the instantaneous effective reduced frequency not accounted for during pure pitching. Deviations from theory, observed at angle-of-attack phase leads of 90° and 180°, were attributed to bursting of separation bubbles during the early stages of the acceleration phase. The largest deviations occurred when the impulsive-pressure lift contribution was small relative to the Joukowsky contribution, because the latter was most affected by bubble bursting. Bubble bursting resulted in large form-drag oscillations that occurred at identical phase angles within the oscillation cycle, irrespective of the phase difference between surging and pitching, as well as in the absence of pitching. KW - Unsteady aerodynamics KW - Dynamic stall KW - Separation bubble KW - Bubble bursting PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-630068 DO - https://doi.org/10.1017/jfm.2025.220 SN - 1469-7645 VL - 1009 SP - 1 EP - 33 PB - Cambridge University Press (CUP) AN - OPUS4-63006 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Rosenbusch, Sjard Mathis A1 - Diercks, Philipp A1 - Kindrachuk, Vitaliy A1 - Unger, Jörg F. T1 - Integrating custom constitutive models into FEniCSx: A versatile approach and case studies N2 - The development and integration of user-defined constitutive relationships into finite element (FE) tools using standardized interfaces play a pivotal role in advancing the capabilities of FE solvers for structural mechanics applications. While commercial FE solvers like Abaqus and Ansys have designed their interfaces to provide custom stresses, tangents, and updated history variables, the open-source solver FEniCSx remains efficient only when the constitutive update has an analytical representation. This restricts the application of FEniCSx for non-linear structural mechanics. Since FEniCSx has become a powerful and popular open-source tool for solving partial differential equations, particularly due to its automatic computation of Hessians, we aim to develop a generalized interface to enhance its capability for constitutive modeling. This approach will address complex constitutive equations that require iterative solutions at the quadrature point level. Specific implementation challenges, such as using return-mapping procedures, can then be managed commonly. The provided interface for custom constitutive models offers a versatile way to implement them in various languages, including C++, Python, Rust, and Fortran. Finally, with UMATs for viscoplastic models as an example, we demonstrate how existing user subroutines can be incorporated into the interface and utilized within the FEniCSx framework. KW - Finite element method KW - Constitutive models KW - FEniCSx KW - UMAT KW - Rust KW - Python KW - C++ PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-630439 DO - https://doi.org/10.1016/j.advengsoft.2025.103922 SN - 0965-9978 VL - 206 SP - 1 EP - 11 PB - Elsevier CY - Amsterdam AN - OPUS4-63043 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Schwettmann-Lui, Kim A1 - Nytus, Nina A1 - Weigel, Sandra A1 - Radenberg, Martin A1 - Stephan, Dietmar T1 - Effect of multiple-repeated aging and rejuvenation processes on bitumen properties evaluated with physical and chemical tests and multivariate analysis methods N2 - This paper presents laboratory experiments on repeated bitumen aging and rejuvenation processes to assess multiple reuse feasibility. Three 50/70 penetration-graded bitumen samples were reused with four different rejuvenators without adding virgin binder. The experiments continued until significant material changes, such as inhomogeneities and increased stickiness, prevented reliable characterization. After each rejuvenation and aging process, physical and chemical properties were analyzed, resulting in a comprehensive dataset. Results indicate that the reuse of pure rejuvenators, without incorporating virgin binder, is limited. Cyclic reuse depends heavily on the rejuvenator and its interaction with the binder. Of the four rejuvenators tested, two bio-based products enabled the maximum reuse of four cycles. Therefore, the rejuvenators used in this project are more suitable as additives to improve the physical properties of the bitumen for reuse rather than as substitutes for the binder. The datasets were further evaluated using multivariate analysis methods to construct statistical models for two use cases: In the first use case, the samples are classified by their aging condition. In the second use case, the samples are differentiated according to the rejuvenators. The models were successfully validated, providing a promising framework for the classification of unknown bitumen samples for reuse. KW - Bitumen KW - Aging KW - Rejuvenation KW - Multiple recycling KW - DSR measurements KW - Reuse KW - FTIR spectroscopy KW - Multivariate analysis methods PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-627563 DO - https://doi.org/10.1016/j.conbuildmat.2025.140734 SN - 1879-0526 VL - 472 SP - 1 EP - 16 PB - Elsevier Ltd. AN - OPUS4-62756 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Herrmann, Ralf A1 - Hille, Falk A1 - Munsch, Sarah Mandy A1 - Telong, Melissa A1 - Unger, Jörg F. A1 - Andrés Arcones, Daniel A1 - Pirskawetz, Stephan T1 - 63. DAfStb-Forschungskolloquium in der BAM - Themenblock 4: Digitalisierung im Bauwesen N2 - Die Digitalisierung hat sich in vielen Bereichen des Bauwesens durchgesetzt. So sind Planung und Entwurf selbst kleinerer Bauvorhaben heute vollständig digitalisiert. Auch das Monitoring von Bestandsbauwerken ist ohne digitale Datenerfassung, -verarbeitung und -speicherung nicht denkbar. Trotzdem sind Fragen hinsichtlich der strukturierten Speicherung und künftigen Nutzung von Daten noch offen. Einige Aspekte der Digitalisierung wurden im Rahmen des 63. DAfStb-Forschungskolloquiums (Tagungsband: DOI 10.26272/opus4-61338) in Vorträgen und Veröffentlichungen aufgegriffen und werden im Folgenden zusammengefasst. T2 - 11. Jahrestagung des DAfStb mit 63. Forschungskolloquium der BAM Green Intelligent Building CY - Berlin, Germany DA - 16.10.2024 KW - Digitalisierung KW - Infrastruktur KW - Structural Health Monitoring KW - Digitaler Zwilling PY - 2025 SN - 0005-9846 VL - 75 IS - 4 SP - 136 EP - 138 PB - concrete content UG CY - Schermbeck AN - OPUS4-63070 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Rogge, Andreas A1 - Meng, Birgit A1 - Kühne, Hans-Carsten T1 - 63. DAfStb-Forschungskolloquium in der BAM - Green Intelligent Building N2 - Das jährlich im Herbst an wechselnden Forschungsstandorten stattfindende DAfStb-Forschungskolloquium wurde im Jahr 2024 von der BAM Bundesanstalt für Materialforschung und -prüfung in Berlin ausgerichtet. Unter der Überschrift „Green Intelligent Building“ referierten rd. 35 Vortragende in fünf Sitzungen unterschiedlicher Thematik über verschiedene betonbezogene Forschungsschwerpunkte in der BAM. Anhand der überwiegend von Doktoranden und Post-Docs dargebotenen Vorträge konnten sich die Teilnehmerinnen und Teilnehmer ein aktuelles Bild von der Qualität der wissenschaftlichen Arbeit und der hervorragenden Forschungsmöglichkeiten in der BAM machen. Durch die Vernetzung unterschiedlich ausgerichteter Fachbereiche innerhalb der BAM werden Synergie-Effekte genutzt. Analytische, baustoffliche, konstruktive, umweltorientierte und auf die Verfahrensentwicklung ausgerichtete Bereiche der BAM forschen gemeinsam zum Thema Stahlbetonbau. Es folgen ausführliche Zusammenfassungen der Tagungsinhalte. T2 - 11. Jahrestagung des DAfStb mit 63. Forschungskolloquium der BAM Green Intelligent Building CY - Berlin, Germany DA - 16.10.2024 KW - Bauteile KW - Bauwerke KW - Beton KW - Chemie der Bindemittel KW - Digitalisierung im Bauwesen KW - Green Intelligent Building KW - Innovative Technologien KW - Klimafreundliche Bindemittel KW - Ressourcenschonung PY - 2025 SN - 0005-9846 VL - 75 IS - 4 SP - 128 EP - 129 PB - concrete content UG CY - Schermbeck AN - OPUS4-63109 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Stawski, Tomasz M. A1 - Salvalaglio, Matteo A1 - Wallace, Adam F. A1 - De Yoreo, James J. T1 - The Birth of Minerals: From Single Step to Multiple Step Mechanisms N2 - Mineral formation from ions in aqueous solutions begins with complex initial stages, where amorphous and liquid-like precursors play pivotal roles before crystalline growth occurs. Both classical and non-classical nucleation and growth theories, introduced in previous chapters, offer explanations, each with their own strengths and limitations, for the complex intermediate phases observed in experimental research. Analytical techniques play a critical role in detecting and characterizing precursor phases, offering valuable insights into nucleation and growth mechanisms across various temporal and spatial scales. Molecular dynamics and modelling provide in-depth perspectives on these phases, allowing for a closer examination of their nucleation and growth mechanisms at the molecular level, and revealing the intricate processes that govern their behaviour. KW - Crystallisation KW - Nucleation KW - Synchrotron KW - Thermodynamics KW - Minerals PY - 2025 DO - https://doi.org/10.2138/gselements.21.1.25 SN - 1811-5217 VL - 21 IS - 1 SP - 25 EP - 32 PB - Mineralogical Society of America AN - OPUS4-62841 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Capitain, C. A1 - Schüßler, M. A1 - Bugsel, B. A1 - Zweigle, J. A1 - Vogel, Christian A1 - Leube, Peter A1 - Zwiener, C. T1 - Implementation of matrix-matched semiquantification of PFAS in AFFF-contaminated soil N2 - This study presents a novel semiquantification approach for nontarget screening (NTS), combining matrix-matched calibration and ionization class-specific average calibration curves (ACCs) to address the lack of analytical reference standards for most per- and polyfluoroalkyl substances (PFAS). Ionization class-specific ACCs for carboxylic and sulfonic acids, sulfonamides, and cationic PFAS result in high accuracy, with median absolute accuracy quotients below 2.27×. The approach was applied to soil impacted by aqueous film-forming foam (AFFF) contamination. A total of 96 tentatively identified PFAS were semiquantified in addition to 28 quantified compounds based on available standards. Semiquantified concentrations exceeded those of target analytes, demonstrating the critical role of this method in capturing broader PFAS contamination. In this case, validation against extractable organofluorine (EOF) showed a 102% closed mass balance. The innovative approach not only enables comprehensive PFAS contamination assessment in complex matrices but also expands the scope of the NTS for environmental monitoring, remediation, and risk assessment of AFFF-contaminated sites. KW - Per- and polyfluoroalkyl substances (PFAS) KW - Contaminated soil KW - Non-targeted analysis KW - Combustion ion chromatography PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-629445 DO - https://doi.org/10.1021/acs.est.4c14255 SN - 1520-5851 VL - 59 IS - 14 SP - 7338 EP - 7347 PB - American Chemical Society (ACS) CY - Columbus, Ohio AN - OPUS4-62944 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - McGonigle, Rebecca A1 - Glasgow, Jodie A1 - Houston, Catriona A1 - Cameron, Iain A1 - Homann, Christian A1 - Black, Dominic J. A1 - Pal, Robert A1 - MacKenzie, Lewis E. ED - MacKenzie, Lewis E. T1 - Autoclave reactor synthesis of upconversion nanoparticles, unreported variables, and safety considerations N2 - Autoclave reactors are widely used across chemical and biological sciences, including for the synthesis of upconversion nanoparticles (UCNPs) and other nanomaterials. Yet, the details of how autoclave reactors are used in such synthesis are rarely reported in the literature, leaving several key synthesis variables widely unreported and thereby hampering experimental reproducibility. In this perspective, we discuss the safety considerations of autoclave reactors and note that autoclaves should only be used if they are (a) purchased from reputable suppliers/manufacturers and (b) have been certified compliant with relevant safety standards. Ultimately, using unsuitable autoclave equipment can pose a severe physical hazard and may breach legal safety requirements. In addition, we highlight several parameters in autoclave synthesis that should be reported as standard to maximise the reproducibility of autoclave synthesis experiments across materials and chemistry research. We encourage users of autoclave synthesis vessels to: (1) adopt high-safety autoclaves and (2) report the many experimental variables involved to enhance experimental reproducibility. KW - Reference material KW - Nano KW - Particle KW - Shell KW - Fluorescence KW - Lifetime KW - Decay kinetics KW - Synthesis KW - Quality assurance KW - Method KW - Energy transfer KW - Upconversion KW - Autoclave synthesis KW - Data comparability PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-625672 DO - https://doi.org/10.1038/s42004-025-01415-3 VL - 8 IS - 1 SP - 1 EP - 7 PB - Springer Science and Business Media LLC AN - OPUS4-62567 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Poka, Konstantin A1 - Ali, Sozol A1 - Saeed, Waleed A1 - Merz, Benjamin A1 - Epperlein, Martin A1 - Hilgenberg, Kai T1 - Quality assurance via a cyber physical system of a PBF-LB/M machine N2 - Powder Bed Fusion with Laser Beam of Metals (PBF-LB/M) faces challenges in reproducibility and quality assurance, even for widely applied alloys like AlSi10Mg. This work introduces a digital provenance framework for PBF-LB/M, showcased through the EOS M 300–4 multi-laser machine. An Extract, Transform, Load (ETL) pipeline autonomously captures machine data, including scan vectors as well as process signals, and organizes them into a Digital Shadow (DS). The DS is further extended by external data sources, such as Melt Pool Monitoring (MPM), to enable comprehensive analysis and root cause identification. This approach ensures continuous data representation and facilitates the development of new quality metrics. Moreover, the framework enhances quality assurance and traceability, supports compliance with industry standards, and improves productivity. It also enables more precise cost calculations and predictive maintenance. By addressing these challenges, the framework is essential for advancing PBF-LB/M in industrial applications, achieving greater consistency and scalability in production. KW - PBF-LB/M KW - Data driven quality assurance KW - Data engineering KW - Digital shadow PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-625187 DO - https://doi.org/10.1007/s40964-025-00978-w SN - 2363-9520 VL - 10 IS - 3 SP - 1771 EP - 1783 PB - Springer Science and Business Media LLC AN - OPUS4-62518 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Schackmann, Oliver A1 - Márquez Reyes, Octavio A. A1 - Memmolo, Vittorio A1 - Lozano, Daniel A1 - Prager, Jens A1 - Moll, Jochen A1 - Kraemer, Peter T1 - Machine learning strategies with ensemble voting for ultrasonic damage detection in composite structures under varying temperature or load conditions N2 - In recent years, the development of machine learning (ML) techniques has led to significant progress in the field of structural health monitoring with ultrasonic-guided waves. However, a number of challenges still need to be resolved for reliable operation in realistic settings. In this work, we consider the complex problem of experimental damage detection under varying temperature or load conditions where damage locations are not included in the training set. The ML techniques proposed here include supervised and unsupervised methods originally developed for image and time series classification combined with ensemble voting. A performance demonstration of the ML techniques is presented using benchmark datasets from the open-guided waves platform. The unsupervised approach is then applied to a new dataset from an experimental campaign carried out on a composite over-wrapped pressure vessel used for hydrogen storage with real defects. Results show that ensemble voting enables the effective combination of the predictions of multiple transducer pairs, even with a limited number of strong individual classifiers. When applied to unsupervised learning, this returns high accuracy also when real damage over the structure is considered. KW - Structural-Health-Monitoring KW - Ultrasonic guided waves PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-631571 DO - https://doi.org/10.1177/14759217251333066 SN - 1741-3168 SP - 1 EP - 19 PB - Sage Publications AN - OPUS4-63157 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Hendricks, A. A1 - Phillips, T. K. A1 - Engl, T. A1 - Plarre, Rudy A1 - Martinson, V. G. T1 - The bacterial microbiome in spider beetles and deathwatch beetles N2 - The beetle family Ptinidae contains a number of economically important pests, such as the cigarette beetle Lasioderma serricorne, the drugstore beetle Stegobium paniceum, and the diverse spider beetles. Many of these species are stored product pests, which target a diverse range of food sources, from dried tobacco to books made with organic materials. Despite the threat that the 2,200 species of Ptinidae beetles pose, fewer than 50 have been surveyed for microbial symbionts, and only a handful have been screened using contemporary genomic methods. In this study, we screen 116 individual specimens that cover most subfamilies of Ptinidae, with outgroup beetles from closely related families Dermestidae, Endecatomidae, and Bostrichidae. We used 16S ribosomal RNA gene amplicon data to characterize the bacterial microbiomes of these specimens. The majority of these species had never been screened for microbes. We found that, unlike in their sister family, Bostrichidae, that has two mutualistic bacteria seen in most species, there are no consistent bacterial members of ptinid microbiomes. For specimens which had Wolbachia infections, we did additional screening using multilocus sequence typing and showed that our populations have different strains of Wolbachia than noted in previous publications. KW - Sodalis KW - Ptinidae KW - Anobiidae KW - Bostrichidae KW - Dermestidae KW - Bostrichoidea KW - Wolbachia PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-631564 DO - https://doi.org/10.1128/spectrum.01981-24 SN - 2165-0497 VL - 13 IS - 5 SP - 1 EP - 14 AN - OPUS4-63156 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 - Jafari, Abbas A1 - Vlachas, K. A1 - Chatzi, E. A1 - Unger, Jörg F. T1 - A Bayesian framework for constitutive model identification via use of full field measurements, with application to heterogeneous materials N2 - In this paper, we present a Bayesian framework for the identification of the parameters of nonlinear constitutive material laws using full-field displacement measurements. The concept of force-based Finite Element Model Updating (FEMU-F) is employed, which relies on the availability of measurable quantities such as displacements and external forces. The proposed approach particularly unfolds the advantage of FEMU-F, as opposed to the conventional FEMU, by directly incorporating information from full-field measured displacements into the model. This feature is well-suited for heterogeneous materials with softening, where the localization zone depends on the random microstructure. Besides, to account for uncertainties in the measured displacements, we treat displacements as additional unknown variables to be identified, alongside the constitutive parameters. A variational Bayesian scheme is then employed to identify these unknowns via approximate posteriors under the assumption of multivariate normal distributions. An optimization problem is then formulated and solved iteratively, aiming to minimize the discrepancy between true and approximate posteriors. The benefit of the proposed approach lies in the stochastic nature of the formulation, which allows to tackle uncertainties related to model parameters and measurement noise. We verify the efficacy of our proposed framework on two simulated examples using gradient damage model with a path-dependent nonlinear constitutive law. Based on a nonlocal equivalent strain norm, this constitutive model can simulate a localized damage zone representing softening and cracking. The first example illustrates an application of the FEMU-F approach to cracked structures including sensitivity studies related to measurement noise and parameters of the prior distributions. In this example, the variational Bayesian solver demonstrates a sizable advantage in terms of computational efficiency compared to a traditional least-square optimizer. The second example demonstrates a sub-domain analysis to tackle challenges associated with limited domain knowledge such as uncertain boundary conditions. KW - Constitutive model identification KW - Full-field measurements KW - Variational Bayes KW - Force-based finite element model updating KW - FEMU-F PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-615476 DO - https://doi.org/10.1016/j.cma.2024.117489 SN - 1879-2138 VL - 433 IS - Part A SP - 1 EP - 32 PB - Elsevier B.V. AN - OPUS4-61547 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Chen‑Wiegart, Yu‑chen Karen A1 - Huber, Norbert A1 - Yager, Kevin G. T1 - Machine learning approaches for intentional materials engineering N2 - The development of nanoporous metals and metallic composites through dealloying processes presents significant opportunities in materials engineering. However, designing multicomponent precursor alloys and establishing corresponding processing methods that yield predictable compositions and nanostructures remain a complex challenge. This article explores how machine learning (ML)-augmented computational and experimental methodologies can tackle these challenges by predicting precursor alloy compositions, final nanoporous structures, and mechanical properties, while integrating ML-enabled autonomous experimentation for material design and quantification. We highlight recent advancements in applying ML to nanostructured materials design via dealloying and discuss how techniques from other nanomaterial designs can be adapted for improved control over morphological and compositional outcomes in nanoporous and nanocomposite materials. Furthermore, we explore the role of ML in autonomous synchrotron x-ray experimentation, enabling real-time feedback between modeling and experimental setups. ML-driven approaches to microstructure characterization and mechanical property prediction are also examined, with a focus on modeling and advanced imaging techniques such as three-dimensional nanotomography. Finally, this article outlines future directions for ML-enhanced materials science, emphasizing the exploration of high-dimensional parameter spaces and the incorporation of materials kinetics into processing and property evaluation, ultimately advancing the design of nanoporous structures and materials science. KW - Artificial intelligence KW - Autonomous KW - Nanostructure KW - X-ray tomography KW - Mechanical properties PY - 2025 DO - https://doi.org/10.1557/s43577-025-00908-9 SN - 1938-1425 VL - 50 IS - 5 SP - 1 EP - 12 PB - Springer Nature CY - London AN - OPUS4-63160 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Thibaux, Philippe A1 - Thiele, Marc A1 - Van Wittenberghe, Jeroen A1 - Baeßler, Matthias T1 - Comparison of resonance and hydraulic testing on large scale fatigue tests of welded tubular joints for offshore wind turbine foundations N2 - Jackets structures as foundations for offshore wind energy converters are efficient solutions. But these structures require the welding of a large number of joints. The design of the Jacket structures is typically driven by fatigue. Therefore, consequently the fatigue strength of the joints is a primary parameter for an optimized design. The present paper investigates if tubular joints produced by manual welding using the current techniques have an improved performance compared to the relevant standards that are applied for the design of the foundations. To investigate this, 4 full-scale tests in geometry representative of a structure were performed, 2 using a resonance method and 2 using a three-point bending method with hydraulic actuators. The results are similar, with cracks initiated early and extending extensively before failure. The results are very close to the current T-curve from DNV RP-C203 applied for tubular joints. KW - Fatigue KW - Tubular joints KW - Resonance testing KW - Steel welds PY - 2025 DO - https://doi.org/10.1016/j.ijfatigue.2024.108797 SN - 0142-1123 VL - 193 SP - 1 EP - 16 PB - Elsevier Ltd. AN - OPUS4-62373 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Schneider, Ronald A1 - Simon, Patrick A1 - Herrmann, Ralf A1 - Hille, Falk A1 - Baeßler, Matthias T1 - Bestandteile Digitaler Zwillinge im Erhaltungsmanagement von Verkehrsbrücken T1 - Components of digital twins in the operation and maintenance management of traffic bridges N2 - Digitale Zwillinge werden zukünftig ein integraler Bestandteil des Erhaltungsmanagements von Verkehrsbrücken sein. In diesem Beitrag wird argumentiert, dass sie nicht nur als digitale Abbilder physikalischer Bauwerke verstanden werden sollten, sondern als eine umfassende digitale Methode, die durch die Integration von Datenerfassung, Erhaltungsmaßnahmen, Datenmanagement, Bauwerksbewertung und Entscheidungsunterstützung die Bauwerksüberwachung und ‐erhaltung verbessert. In diesem Zusammenhang wird betont, dass der Übergang von der reaktiven zur prädiktiven Erhaltung durch den Einsatz von Digitalen Zwillingen nur dann realisierbar ist, wenn neben den erforderlichen diagnostischen und prognostischen Zustandsanalysen auch Methoden zur Optimierung von Entscheidungen über Datenerfassung und Erhaltungsmaßnahmen implementiert werden. Zur Veranschaulichung der Diskussion werden in diesem Beitrag exemplarisch zwei Bestandteile eines Digitalen Zwillings für das Erhaltungsmanagement von Verkehrsbrücken am Beispiel einer Eisenbahnbrücke demonstriert. Dabei wird zum einen gezeigt, wie Monitoringdaten mittels eines Datenmanagementsystems strukturiert verwaltet und für angeknüpfte Analysen bereitgestellt werden. Zum anderen erfolgt im Rahmen einer bauwerksspezifischen Einwirkungsermittlung eine Zugidentifikation anhand von gemessenen Schwellenschwingungen. N2 - Digital twins will become an integral part of the operation and maintenance management of traffic bridges in the future. This paper argues that they should not only be understood as digital representations of physical structures but as a digital methodology that enhances the operation and maintenance of bridges through the integration of data collection, maintenance actions, data management, structural assessment, and decision support. In this context, it is emphasized that the transition from reactive to predictive maintenance using digital twins can only be achieved if, in addition to the necessary diagnostic and prognostic condition analyses, methods for optimizing decisions on data collection and maintenance actions are also implemented. To illustrate this discussion, two key components of a digital twin for the operation and maintenance management of traffic bridges are demonstrated using a railway bridge as an example. First, it is shown how monitoring data can be systematically managed and made available for subsequent analyses through a data management system. Second, train identification based on measured sleeper vibrations is conducted as part of an object-specific load assessment. KW - Digitale Zwillinge KW - Erhaltung KW - Inspektion KW - Monitoring KW - Brücken PY - 2025 DO - https://doi.org/10.1002/bate.202400101 SN - 1437-0999 SP - 1 EP - 11 PB - Ernst & Sohn CY - Berlin AN - OPUS4-62837 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Pfennig, A. A1 - Simkin, Roman T1 - Identifying the initial corrosion fatigue failure based on dropping electrochemical potential N2 - The corrosion fatigue of duplex stainless-steel X2CrNiMoN22-5-3 can be determined by purely alternating axial cyclic load to failure using hour-glass shaped specimens. The experimental setup comprises a corrosion chamber allowing for the circulation of an aquifer electrolyte heated to 369 K simulating a carbon capture and storage as well as geothermal power plant environment. During engineering of a carbon storage site or geothermal power plant, it may be crucial to determine the failure onset of a component beforehand. Therefore, an algorithm with 93.3% reliability was established based on splitting the measured potential values into ten time series with a capacity of ten values. The failure of corrosion fatigue specimens in a geothermal environment correlates to the drop of the curves of the electrochemical potential which is measured simultaneously within the corrosion chamber. Crack initiation was, therefore, successfully derived from the electrochemical potential. KW - Corrosion fatigue KW - Surface corrosion KW - CO2 KW - Crack initiation KW - Geothermal energy production PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-629310 DO - https://doi.org/10.3390/app15010403 SN - 2076-3417 VL - 15 IS - 1 SP - 1 EP - 15 PB - MDPI CY - Basel AN - OPUS4-62931 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kumar, Sumit A1 - Swaminathan, Srinivasan A1 - Hesse, Rene A1 - Goldbeck, Hennig A1 - Ding, Wenjin A1 - Bonk, Alexander A1 - Bauer, Thomas T1 - Understanding the effect of oxide ions on Solar Salt chemistry and corrosion mechanism of 316L stainless steel at 600 °C N2 - Solar Salt (60 wt% NaNO3, 40 wt% KNO3), used in Concentrated Solar Power (CSP) Thermal Energy Storage (TES) technology, can decompose into various products at elevated temperatures, with oxide ions being one of the known corrosive byproducts. The study mimics Solar Salt aging by intentionally adding sodium peroxide (Na2O2) and sodium oxide (Na2O) at concentrations of 0.005–0.33 wt% to investigate their role in the corrosion of austenitic stainless steel at 600 °C in typical operating conditions. Salt chemistry (nitrite, nitrate, oxide ions, and metal cations) was analyzed every 24 h, and steel corrosion after 168 h was assessed by weight change, corrosion rate, phase analysis, and cross-sectional morphology. Results reveal that at or above 0.135 wt% added Na2O2/Na2O leads to a quasi-steady-state equilibrium of oxide ions in the salt. Interestingly, at these concentrations, the presence of steel further decreases oxide ion concentration. Furthermore, above 0.135 wt%, the corrosion rate increases significantly, along with increased spallation, porosity and disintegration of the corrosion layer, forming a non-protective layer. This study highlights the critical role of oxide ions in the corrosion process. KW - Solar Salt KW - High temperature corrosion KW - Thermal Energy Storage KW - Alkali oxides KW - Austenitic stainless steel PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-628463 DO - https://doi.org/10.1016/j.corsci.2025.112849 SN - 1879-0496 VL - 249 SP - 1 EP - 17 PB - Elsevier Ltd. AN - OPUS4-62846 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -