TY - JOUR A1 - Ladu, Luana A1 - Matovic, Nikola A1 - Imbert, Enrica A1 - Encino-Munoz, Ana T1 - How to measure the robustness and effectiveness of certification schemes and labels in ensuring the sustainability of bio-based products N2 - The rapid proliferation of sustainability certification schemes and labels (CSLs) reflects the rising demand for sustainable products, although the robustness and effectiveness of these certification systems have been increasingly questioned. While CSLs aim to mitigate environmental and socio-economic risks and support responsible market practices, current monitoring systems of CSLs often lack coherence, transparency, and methodological robustness. This study addresses this gap by proposing a conceptual monitoring framework specifically tailored to the bioeconomy, addressing the complexity of global bio-based value chains. Developed through a systematic literature review, a comparative analysis of 26 academic studies and 19 monitoring tools, and stakeholder engagement via interviews and co-creation workshops, the framework introduces a multidimensional structure for evaluating CSLs across three core functions: (I) Building Trust and Transparency, (II) Protecting Sustainability Areas of Concern, and (III) Driving Continuous Improvement. A pilot benchmarking exercise using the Global Organic Textile Standard (GOTS) demonstrates the framework’s applicability and diagnostic value, revealing both strong alignment in some areas and performance gaps in others—particularly in the economic and circularity dimensions. The framework is designed as a dynamic and modular tool, suitable for use by policymakers, scheme owners, businesses, and consumers. It holds potential to harmonize evaluation practices, guide co-regulatory policy integration, and foster more transparent and credible sustainability certification systems in the bioeconomy meta-sector. KW - Monitoring System KW - Sustainability Certification Schemes KW - Labels KW - Standards KW - Bioeconomy PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-640000 DO - https://doi.org/10.1016/j.jenvman.2025.126240 SN - 1095-8630 VL - 390 SP - 1 EP - 14 PB - Elsevier Ltd. AN - OPUS4-64000 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Agasty, Amit A1 - Costard, Rene A1 - Kadoke, Daniel A1 - Kind, Thomas A1 - Hicke, Konstantin A1 - Hüsken, Götz T1 - A comprehensive experimental assessment of reinforced concrete walls under blast: In situ monitoring of loading, dynamic response and damage with NDT methods and embedded sensors N2 - A safety or security related assessment of explosions, accidental and intentional scenarios alike, often necessitate performance of resource intensive replication tests. For an efficient assessment without performing full scale blast tests, e.g., supported by numerical simulations, detailed knowledge is necessary to predict the blast loading from a given charge configuration, the resulting dynamic response of the structure under investigation as well as the resulting damage. Validation of numerical simulation requires the spatially resolved acquisition of all these parameters in real time. In this paper we present a set of measurement techniques and discuss their suitability for monitoring reinforced concrete (RC) walls under blast loading. Different blast-loading scenarios were realized by varying the charge weight and the standoff distance. The dynamic loading of the wall was characterized with pressure sensors complemented by numerical simulations using the APOLLO Blastsimulator and ConWep. High speed digital image correlation (DIC) was implemented in combination with multiple acceleration sensors to observe the dynamic deflection of the walls during the loading and to determine the residual deformation after the loading had ceased. In addition, one test specimen was instrumented with fiber optic sensor cables. These fiber optic sensors were used for distributed acoustic sensing (DAS) delivering information on dynamics of compression and tension cycles from within the structure. Additionally, the local damage pattern emerging during the series of blasts was determined via distributed fiber optic strain sensing (DSS) to enable the characterization of visual and non-visual damage to the structure. The obtained information was compared to results by an ultrasound structure-scanner. KW - Blast testing KW - Reinforced concrete KW - NDT methods KW - Fiber optic sensing KW - DIC KW - Numerical simulations KW - APOLLO Blastsimulator PY - 2025 DO - https://doi.org/10.1177/20414196251353795 SN - 2041-4196 SP - 1 EP - 31 PB - Sage Publications AN - OPUS4-63832 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kossatz, Philipp A1 - Mezhov, Alexander A1 - Andresen, Elina A1 - Prinz, Carsten A1 - Schmidt, Wolfram A1 - Resch-Genger, Ute T1 - Assessing the Applicability of Lanthanide-Based Upconverting Nanoparticles for Optically Monitoring Cement Hydration and Tagging Building Materials N2 - Chemically stable, lanthanide-based photon upconversion micro- and nanoparticles (UCNPs) with their characteristic multicolor emission bands in the ultraviolet (UV), visible (vis), near-infrared (NIR), and short-wave infrared (SWIR) arepromising optical reporters and barcoding tags. To assess the applicability of UCNPs for the monitoring of early stage cement hydration processes and as authentication tags for cementitious materials, we screened the evolution of the luminescence of Selfmade core-only NaYF4:Yb,Er UCNPs and commercial μm-sized Y2O2S:Yb,Er particles during the first stages of cement hydration, which largely determines the future properties of the hardened material. Parameters explored from the UCNP side included particle size, morphology, surface chemistry or coating, luminescence properties, and concentration in different cement mixtures. From the cement side, the influence of the mineral composition of the cement matrix was representatively examined for ordinary Portland cement (OPC) and its constituents tricalcium aluminate (C3A), tricalcium silicate (C3S), and gypsum at different water to cement ratios. Based on reflection and luminescence measurements, enabling online monitoring, which were complemented by XRD and isothermal heat-flow calorimetric measurements to determine whether the incorporation of these particles could impair cement hydration processes, well suited lanthanide particle reporters could be identified as well as application conditions. In addition, thereby the reporter influence on cement hydration kinetics could be minimized while still preserving a high level of information content. The best performance for the luminescence probing of changes during early stage cement hydration processes was observed for 25 nm-sized oleate (OA)-coated UCNPs added in a concentration of 0.1 wt %. Higher UCNP amounts of 1.0 wt % delayed cement hydration processes size- and surface coatingspecifically in the first 24 h. Subsequent luminescence stability screening studies performed over a period of about one year support the applicability of UCNPs as optical authentication tags for construction materials. KW - Quality assurance KW - Fluorescence KW - Nano KW - Particle KW - Synthesis KW - Quantum yield KW - NIR KW - Mechanism KW - Characterization KW - XRD KW - Calorimetry KW - Advanced material KW - Cement KW - Monitoring KW - Surface KW - Size KW - Lifetime KW - Barcode KW - Lanthanide KW - Upconversion KW - Encoding KW - Method PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-638318 DO - https://doi.org/10.1021/acsomega.5c02236 SN - 2470-1343 VL - 10 IS - 29 SP - 31587 EP - 31599 PB - ACS Publications CY - Washington, DC AN - OPUS4-63831 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Wetzel, Annica A1 - Hans, Ann-Kathrin A1 - von der Au, Marcus A1 - Brand, Izabella A1 - Wittstock, Gunther A1 - Özcan Sandikcioglu, Özlem A1 - Witt, Julia T1 - Long-term corrosion studies of CrCoNi and CrMnFeCoNi in sulfuric acid N2 - This study investigates the long-term corrosion behavior of CrCoNi and CrMnFeCoNi MPEAs over 28 d in 1 M H2SO4. Corrosion progression and passive film evolution were analyzed using open circuit potential measurements, electrochemical impedance spectroscopy, X-ray photoelectron spectroscopy, and scanning electron microscopy. Unlike short-term polarization tests, where CrCoNi exhibited intergranular corrosion, long-term immersion resulted in a stable, Cr-rich passive oxide layer. In contrast, CrMnFeCoNi formed a porous mixed oxide layer, increasing its susceptibility to degradation and revealing a distinct corrosion mechanism. X-ray photoelectron spectroscopy tracking at weekly intervals showed that prolonged immersion led to the transformation of sulfide/sulfite species into a sulfate-containing surface film. This effect was only detectable in long-term corrosion studies. These findings provide new insights into the time-dependent degradation mechanisms of MPEAs and demonstrate that corrosion mechanisms differ significantly from short-term polarization tests. This highlights the need for long-term studies to properly assess material stability in practical applications. KW - Long-term corrosion KW - Multi-principal element alloys (MPEAs) KW - X-ray photoelectron spectroscopy (XPS) PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-636895 DO - https://doi.org/10.1038/s41529-025-00637-z SN - 2397-2106 VL - 9 IS - 1 SP - 1 EP - 13 PB - Springer Science and Business Media LLC AN - OPUS4-63689 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Horton, Matthew K. A1 - Huck, Patrick A1 - Yang, Ruo Xi A1 - Munro, Jason M. A1 - Dwaraknath, Shyam A1 - Ganose, Alex M. A1 - Kingsbury, Ryan S. A1 - Wen, Mingjian A1 - Shen, Jimmy X. A1 - Mathis, Tyler S. A1 - Kaplan, Aaron D. A1 - Berket, Karlo A1 - Riebesell, Janosh A1 - George, Janine A1 - Rosen, Andrew S. A1 - Spotte-Smith, Evan W. C. A1 - McDermott, Matthew J. A1 - Cohen, Orion A. A1 - Dunn, Alex A1 - Kuner, Matthew C. A1 - Rignanese, Gian-Marco A1 - Petretto, Guido A1 - Waroquiers, David A1 - Griffin, Sinead M. A1 - Neaton, Jeffrey B. A1 - Chrzan, Daryl C. A1 - Asta, Mark A1 - Hautier, Geoffroy A1 - Cholia, Shreyas A1 - Ceder, Gerbrand A1 - Ong, Shyue Ping A1 - Jain, Anubhav A1 - Persson, Kristin A. T1 - Accelerated data-driven materials science with the Materials Project N2 - The Materials Project was launched formally in 2011 to drive materials discovery forwards through high-throughput computation and open data. More than a decade later, the Materials Project has become an indispensable tool used by more than 600,000 materials researchers around the world. This Perspective describes how the Materials Project, as a data platform and a software ecosystem, has helped to shape research in data-driven materials science. We cover how sustainable software and computational Methods have accelerated materials design while becoming more open source and collaborative in nature. Next, we present cases where the Materials Project was used to understand and discover functional materials. We then describe our eforts to meet the needs of an expanding user base, through technical infrastructure updates ranging from data architecture and cloud resources to interactive web applications. Finally, we discuss opportunities to better aid the research community, with the vision that more accessible and easy-to-understand materials data will result in democratized materials knowledge and an increasingly collaborative community. KW - Databases KW - Materials Informatics KW - Materials Design KW - Automation KW - Workflows KW - Accelerated Discovery PY - 2025 DO - https://doi.org/10.1038/s41563-025-02272-0 SN - 1476-1122 SP - 1 EP - 11 PB - Springer Science and Business Media LLC AN - OPUS4-63616 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Peters, Simon A1 - Pittrich, Tim A1 - Stelzner, Ludwig A1 - Weise, Frank A1 - Meschke, Günther T1 - Concretes containing blended-cements with reduced carbon-dioxide emissions: A chemo-thermo-hygro-mechanical model for elevated temperatures N2 - A comprehensive analysis aimed at understanding and assessing the high-temperature behavior of concretes containing blended cements (CEM III/A, CEM II/B-Q, and CEM IV), characterized by low carbon-dioxide emissions (during clinker’s production) is necessary to reliably model the damage in the concrete, thermal spalling included. To this purpose, a numerical chemo-thermo-hygro-mechanical model is formulated, to investigate – among other phenomena – heat transmission and pore pressure for different aggregate types. Based on an available hydration model, a dehydration model is established to numerically investigate the evolution of dehydration and porosity at elevated temperatures. Based on the properties of concrete and cement constituents on multiple scales, an analytical homogenization process is proposed to predict the thermal conductivity of the concrete. This process is later validated and implemented into a macroscopic modeling framework. Chemo-thermo-hygro-mechanical analyses show that the dehydration characteristics of blended low carbon-dioxide release cements may increase pore pressure in the concrete by up to 13% compared to the concrete containing ordinary Portland cement. In addition, aggregates exhibiting high thermal conductivity may contribute to a further increase (even more than 35%) in pore pressure compared to aggregates with low thermal conductivity. Last but not least, the proposed model provides the basis for the reduction of the number of the parameters commonly required in the chemo-thermo-hygro-mechanical modeling of cementitious materials. KW - Concrete at high temperature KW - Dehydration KW - Multiscale modeling KW - Thermal conductivity KW - Chemo-hygro-thermal analysis KW - Micromechanics PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-635894 DO - https://doi.org/10.1016/j.cemconcomp.2025.106163 SN - 0958-9465 VL - 163 SP - 1 EP - 17 PB - Elsevier CY - Amsterdam AN - OPUS4-63589 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Ikeda, Yuki A1 - Wallis, Theophilus A1 - Maaß, Robert A1 - Darvishi Kamachali, Reza T1 - Thermodynamics of grain boundary segregation transition and their relevance for liquid metal embrittlement in Fe-Zn system N2 - Grain boundaries (GBs) are common sites of failure in polycrystalline materials. Recently, a massive Zn segregation transition at Fe GBs was discovered and shown to act as a potent precursor of liquid metal embrittlement (LME) in the Fe-Zn system (Kamachali et al., Scripta Materialia 238 (2024) 115758). In this study, we elaborate on how temperature, GB type and the chemo-structurally coupled phase decomposition at the GB impact this segregation transition. CALPHAD and atomistic simulation data were utilized as inputs to conduct quantitative density-based thermodynamic modeling and phase-field simulations across various GBs, alloy compositions, and temperatures. We reveal that once the segregation transition becomes possible, the GB structural variation stabilizes spinodally formed Zn-rich phases within the GB region, with a higher tendency in disordered GBs. GB phase diagrams were constructed to identify and analyze the range of critical temperatures and alloy compositions associated with the segregation transition. The phase diagrams reveal that the miscibility gap for more disordered GB expands and, although the segregation transition is inevitable and occurs for all GBs, the barrier to triggering it is lower for more disordered GBs. Based on our thermodynamic analyses, potential processing modifications and GB engineering strategies for mitigating segregation-induced LME are thoroughly discussed. KW - Thermodynamics KW - Phase-Field Modelling KW - Steels PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-634145 DO - https://doi.org/10.1016/j.actamat.2025.121134 SN - 1359-6454 VL - 296 SP - 1 EP - 11 PB - Elsevier BV AN - OPUS4-63414 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Ciornii, Dmitri A1 - Hodoroaba, Vasile-Dan A1 - Wachtendorf, Volker A1 - Fengler, Petra A1 - Altmann, Korinna T1 - Interlaboratory Comparison Reveals State of the Art in Microplastic Detection and Quantification Methods N2 - In this study, we investigate the current accuracy of widely used microplastic (MP) detection methods through an interlaboratory comparison (ILC) involving ISO-approved techniques. The ILC was organized under the prestandardization platform of VAMAS (Versailles Project on Advanced Materials and Standards) and gathered a large number (84) of analytical laboratories across the globe. The aim of this ILC was (i) to test and to compare two thermo-analytical and three spectroscopical methods with respect to their suitability to identify and quantify microplastics in a water-soluble matrix and (ii) to test the suitability of the microplastic test materials to be used in ILCs. Two reference materials (RMs), polyethylene terephthalate (PET) and polyethylene (PE) as powders with rough size ranges between 10 and 200 μm, were used to press tablets for the ILC. The following parameters had to be assessed: polymer identity, mass fraction, particle number concentration, and particle size distribution. The reproducibility, SR, in thermo-analytical experiments ranged from 62%−117% (for PE) and 45.9%−62% (for PET). In spectroscopical experiments, the SR varied between 121% and 129% (for PE) and 64% and 70% (for PET). Tablet dissolution turned out to be a very challenging step and should be optimized. Based on the knowledge gained, development of guidance for improved tablet filtration is in progress. Further, in this study, we discuss the main sources of uncertainties that need to be considered and minimized for preparation of standardized protocols for future measurements with higher accuracy. KW - Microplastics KW - Interlaboratory comparison KW - PlasticsFatE KW - PET KW - PE KW - Reference materials KW - VAMAS KW - Thermo-analytical methods KW - Spectroscopical methods PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-630462 DO - https://doi.org/10.1021/acs.analchem.4c05403 SN - 1520-6882 VL - 97 SP - 8719 EP - 8728 PB - ACS Publications AN - OPUS4-63046 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Gupta, Kanhaiya A1 - Poka, Konstantin A1 - Ulbricht, Alexander A1 - Waske, Anja T1 - Identification and authentication of additively manufactured components using their microstructural fingerprint N2 - In the field of additive manufacturing, the ability to uniquely identify and authenticate parts is crucial for certification, logistics, and anti-counterfeiting efforts. This study introduces a novel methodology that leverages the intrinsic microstructural features of additively manufactured components for their identification, authentication, and traceability. Unlike traditional tagging methods, such as embedding QR codes on the surface or within the volume of parts, this approach requires no alteration to the printing process, as it utilizes naturally occurring microstructural characteristics. The proposed workflow involves the analysis of 3D micro-computed tomography data to identify specific voids that meet predefined identification criteria. This method is demonstrated on a batch of 24 parts manufactured with identical process parameters, proving capable of achieving unambiguous identification and authentication. By establishing a tamper-proof link between the physical part and its digital counterpart, this methodology effectively bridges the physical and digital realms. This not only enhances the traceability of additively manufactured parts but also provides a robust tool for integrating digital materials, parts databases, and product passports with their physical counterparts. KW - Authentication KW - Additive manufacturing KW - X-ray Computed Tomography KW - Digital fingerprint KW - Unique identification PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-630356 DO - https://doi.org/10.1016/j.matdes.2025.113986 SN - 1873-4197 VL - 254 SP - 1 EP - 12 PB - Elsevier Ltd. CY - Amsterdam AN - OPUS4-63035 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Lu, Xin A1 - Hicke, Konstantin T1 - Error suppression in wavelength scanning coherent optical time domain reflectometry by polarization diversity detection N2 - Wavelength scanning coherent optical time domain reflectometry (WS-COTDR) is a popular distributed fiber sensing technique that quantifies environmental changes based on the frequency shift of Rayleigh reflection spectra which are usually obtained by cross correlation. This method can cause large errors due to the spikes in the spectrum caused by the random interference of the Rayleigh backscattered light and the uncorrelated section in the reflection spectrum. Polarization diversity detection is applied to suppress this type of error. Two orthogonally polarized components of the Rayleigh backscattered light are detected in a single sensing system and processed separately by cross correlation. The correlation spectra of the two polarizations are averaged to determine the frequency shift, effectively mitigating the large error. Meanwhile, the polarization dependence helps avoid the large errors caused by Fresnel reflection and restrain null sensitivity positions, where the frequency shift is difficult to be determined due to the similarity of the spectra. The sensing performance improvement is experimentally validated, and the proposed system is tested in the field to monitor traffic along a busy street in Berlin, demonstrating its functionality and feasibility in practice. KW - Traffic monitoring KW - Coherent optical time domain reflectometry KW - Distributed fiber sensing KW - Polarization diversity detection KW - Optical fiber sensing PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-630320 DO - https://doi.org/10.1016/j.measurement.2025.117733 SN - 1873-412X VL - 253 SP - 1 EP - 11 PB - Elsevier Ltd. AN - OPUS4-63032 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Vega Puga, E. A1 - Wachtendorf, Volker A1 - Kömmling, Anja A1 - Brendelberger, S. A1 - Jaunich, Matthias A1 - Sattler, C. T1 - Lifetime prediction and degradation assessment of FKM and FFKM O-rings under high temperature thermo-oxidative ageing N2 - To support the development of solar reactor technologies for hydrogen production, this study investigates the thermo-oxidative degradation mechanisms of fluorinated elastomers and predicts their lifetimes at high temperatures (200–300 ◦C) consistent with the application requirements. An accelerated ageing programme is conducted with FKM and FFKM O-rings and flat samples for up to 21 days. Optical microscopy is used to analyse the exposed seals’ morphological changes, while IR microscopy is utilised to investigate the underlying chemical degradation mechanisms of both elastomers. Findings suggest that FKM’s degradation arises from dehydrofluorination of the polymer, followed by chain scission and backbone cleavage as a result of the oxidation of newly formed C=C double bonds. FFKM’s degradation is primarily associated with chain scission, but there is also indication that post-curing processes may occur during material ageing. Furthermore, hardness, equilibrium compression set (CS), continuous compression stress relaxation (CSR) and leakage rate tests are used to evaluate changes in the mechanical properties and sealing performance of the elastomers. Equilibrium CS data is extrapolated using time-temperature shifts (TTS) and used to derive an end-of-life criterion of 75 % equilibrium CS, which correlates to leakage rates higher than a predetermined threshold. Service lifetime predictions of FKM and FFKM O-rings at several temperatures are performed and a seal operating temperature of 200 ◦C is suggested, which ensures reasonable O-ring replacement intervals of more than half a year in the solar reactor for both considered materials. KW - Fluoroelastomer KW - Perfluoroelastomer KW - Thermo-oxidative ageing KW - Lifetime prediction KW - Compression set PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-630112 DO - https://doi.org/10.1016/j.polymertesting.2025.108820 SN - 1873-2348 VL - 147 SP - 1 EP - 17 PB - Elsevier BV CY - Amsterdam AN - OPUS4-63011 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Richter, Matthias A1 - Schühle, Florian T1 - Experimental determination of 7-day uptake rates for diffusive sampling of 86 volatile and semi-volatile organic compounds relevant for indoor air monitoring and investigation on their sensitivity to exposure time and indoor climate N2 - This study aimed to experimentally determine uptake rates for 86 indoor relevant volatile and semi-volatile organic compounds (VOC, SVOC) for the passive sampler type Perkin Elmer/Markes™ with Tenax® TA as sorbent, which was used in the German Environmental Survey on Health (GerES VI) carried out by the German Environmental Agency (UBA) in the years 2023-2024. For this purpose, single reference gas atmospheres of 76 pure VOCs (liquid at room temperature) and a group of 10 SVOCs and VOCs (solid at room temperature) were generated using two generation procedures. By exposing the samplers to individual components, it was ruled out that interactions in a mixture have a influence on the uptake rate. Another aspect was to precisely describe the methodology and the resulting uncertainties, as there are gaps in the literature in this regard. The selection of the compounds was based on the findings of the preceding GerES V study for which data was missing or needed to be verified. In each experiment, a number of six passive samplers was exposed to the test gas atmospheres in dynamically operated exposure chambers for seven days. The sensitivity of the uptake rates of a group of 10 selected VOCs to variations in exposure time, ambient temperature, and air humidity in a multi-component reference gas atmosphere was investigated. Here, a decrease in the uptake rate with the exposure time could be observed stabilising from the fifth day of exposure onwards. A significant effect of temperature and humidity on the uptake rate was not apparent. The determined uptake rates exhibit uncertainties of < 20 % for 71 substances, and < 10 % for 51 substances which are also in good agreement with the literature, if already published elsewhere. The quantity of investigated substances, the detailed description of the methodology used to determine the uptake rates complemented by the respective uncertainties, as well as the compilation of comparative data, contribute to a better assessment of the quality and relevance of such data, which had not been published before. KW - Indoor air quality KW - Volatile organic compounds KW - Uptake rates KW - Passive sampling KW - Tenax TA PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-629913 DO - https://doi.org/10.1016/j.indenv.2025.100095 VL - 2 IS - 2 SP - 1 EP - 11 PB - Elsevier AN - OPUS4-62991 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Bubel, Martin A1 - Schmid, Jochen A1 - Carmesin, Maximilian A1 - Kozachynskyi, Volodymyr A1 - Esche, Erik A1 - Bortz, Michael T1 - Cubature-based uncertainty estimation for nonlinear regression models N2 - Models are commonly utilized in chemical engineering to simulate real-world processes and phenomena. Given their role in guiding decision-making, accurately quantifying the uncertainty of these models is essential. Typically, these models are calibrated using experimental data that contain measurement errors, leading to uncertainty in the fitted model parameters. Current methods for estimating the prediction uncertainty of nonlinear regression models are often either computationally intensive or biased. In this study, we use sparse cubature formulas to estimate the prediction uncertainty of nonlinear regression models. Our findings indicate that this method provides a favorable balance between accuracy and computational efficiency, making it suitable for application in chemical engineering. We validate the performance of our proposed method through various regression case studies, including both theoretical toy models and practical models from chemical engineering. KW - Nonlinear models KW - Model uncertainty KW - Parameter estimation PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-628008 DO - https://doi.org/10.1016/j.compchemeng.2025.109035 SN - 1873-4375 VL - 197 SP - 1 EP - 23 PB - Elsevier Ltd. AN - OPUS4-62800 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Zaki, Mohammad A1 - Prinz, Carsten A1 - Ruehle, Bastian T1 - A Self-Driving Lab for Nano- and Advanced Materials Synthesis N2 - The recent emergence of self-driving laboratories (SDL) and material acceleration platforms (MAPs) demonstrates the ability of these systems to change the way chemistry and material syntheses will be performed in the future. Especially in conjunction with nano- and advanced materials which are generally recognized for their great potential in solving current material science challenges, such systems can make disrupting contributions. Here, we describe in detail MINERVA, an SDL specifically built and designed for the synthesis, purification, and in line characterization of nano- and advanced materials. By fully automating these three process steps for seven different materials from five representative, completely different classes of nano- and advanced materials (metal, metal oxide, silica, metal organic framework, and core–shell particles) that follow different reaction mechanisms, we demonstrate the great versatility and flexibility of the platform. We further study the reproducibility and particle size distributions of these seven representative materials in depth and show the excellent performance of the platform when synthesizing these material classes. Lastly, we discuss the design considerations as well as the hardware and software components that went into building the platform and make all of the components publicly available. KW - Self-driving laboratories KW - Materials acceleration platforms KW - Nanomaterials KW - Advanced materials KW - Automation KW - Robotics KW - In-line characterization PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-627361 DO - https://doi.org/10.1021/acsnano.4c17504 SN - 1936-086X VL - 19 IS - 9 SP - 9029 EP - 9041 PB - ACS Publications CY - Washington, DC AN - OPUS4-62736 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Gödde, Markus A1 - Clemens, Jörg A1 - Malow, Marcus T1 - Screening Procedures for Self-Reactive Substances, Differential Scanning Calorimetry-Onset and Heat-Flux Criteria N2 - We present a newscreening procedure for the determination of the thermal stability of potential candidates for the class of self-reactive substances. For the classification of self-reactive substances, elaborate testing is necessary to determine the applicable type, according to the regulations. Annex 6 of the UNManual of Tests and Criteria permits that the classification procedure for self-reactive substances may be omitted, if the estimated self accelerating decomposition temperature (SADT) is greater than 75 °C for a 50 kg package using an appropriate calorimetric technique, but no technique is described. Based on stationary theories of thermal explosion, we developed a screening approach using differential scanning calorimetry (DSC) onset and heat-flux criteria, respectively, at relevant temperatures. The proposed approach is validated with experimental data. KW - Self-reactive substances KW - Classification KW - Differential scanning calorimetry KW - Self accelerating decomposition temperature KW - Screening-procedures PY - 2025 DO - https://doi.org/10.1002/ceat.12006 SN - 1521-4125 SP - 1 EP - 9 PB - Wiley-VCH GmbH AN - OPUS4-62678 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Devi, Sarita A1 - Riedel, Soraya A1 - Döring, Sarah A1 - Hiller, Lukas A1 - Kaliyaraj Selva Kumar, Archana A1 - Flemig, Sabine A1 - Singh, Chandan A1 - Konthur, Zoltán A1 - Hodoroaba, Vasile-Dan A1 - Schneider, Rudolf T1 - Antibodies Functionalized Magnetic Fe-Metal-Organic Framework Based Biosensor for Electrochemical Detection of Tetanus Neurotoxin N2 - This work presents a metal-organic framework (MOF)-integrated microfluidic flow-cell (MFC) based immunodetection of the tetanus toxoid (TT) using electrochemical technique for the first time. The magnetic property of Fe-MOF helped to hold them on the working electrode at detection zone of MFC surpassing the requirement of additional conjugation chemistry, whereas the conductive property was utilized to observe the change in signal efficiency in the presence of TT. The one-pot hydrothermal synthesis of a magnetic and conductive iron-based MOF (Fe-MOF) was performed using the Fe3 +/Fe2+ precursors as 1.2/1 mmol and dual ligands, i.e., tetrahydroxy-1,4-benzoquinone and 2-aminobenzene-1,4-dicarboxylic acid. The Fe-MOF was conjugated with L-phenylalanine (Fe-MOF/Phe) to increase its electric conductivity owing to the enhanced electron flow rate. The human monoclonal antibody SA13 against TT (anti-TT mAb) was conjugated on the Fe-MOF/Phe surface with the help of ethylenediamine (Fe-MOF/Phe/EDA/anti-TT mAb). The binding affinity of Fe-MOF/Phe/EDA/anti-TT mAb for the TT antigen was evaluated using cyclic voltammetry technique. The limit of detection of the Fe-MOF/Phe/EDA/anti-TT mAb-based biosensor for TT was 9.4 ng/ml in spiked buffer. This study shows the applicability of these Fe-MOFs in the detection of various other microbial toxins or other biomolecules. KW - Antikörper KW - Elektrochemischer Immunoassay KW - Molecular Organic Framework (MOF) KW - Microfluidics KW - Rekombinant PY - 2025 DO - https://doi.org/10.1016/j.snb.2025.137381 SN - 0925-4005 VL - 431 SP - 1 EP - 12 PB - Elsevier B.V. CY - Amsterdam AN - OPUS4-62673 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Popiela, Bartosz A1 - Günzel, Stephan A1 - Schukar, Marcus A1 - Mair, Georg W. A1 - Krebber, Katerina A1 - Seidlitz, Holger T1 - Impact of internal pressure control during manufacturing on residual stresses and safety performance of type 4 pressure vessels N2 - Composite pressure vessels are commonly manufactured using the wet filament winding process, where various process parameters can influence the performance of the finished component. In this study two designs of wet filament wound 6.8-liter type 4 composite pressure vessels were manufactured. Both differ only by the internal pressure used during the filament winding, which primarily influences the residual stress state in the composite structure. An extensive experimental study was carried out, including 10 slow burst tests and strain measurements with fiber optic sensors. Significant differences can be observed in the performance of the two designs even though the used stacking sequence, materials and other manufacturing parameters are the same for both designs. A discussion of the differences in the behavior of both cylinder types is provided, including the strain distribution in slow burst tests and failure mechanism. KW - Residual stresses KW - Slow burst tests KW - Filament winding KW - Type 4 composite pressure vessels KW - Hydrogen PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-626663 DO - https://doi.org/10.1016/j.jcomc.2025.100581 SN - 2666-6820 VL - 17 SP - 1 EP - 9 PB - Elsevier B.V. CY - Amsterdam, Netherlands AN - OPUS4-62666 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Farhan, Muhammad A1 - Schneider, Ronald A1 - Thöns, Sebastian A1 - Gündel, M. T1 - Probabilistic cost modeling as a basis for optimizing inspection and maintenance of turbine support structures in offshore wind farms N2 - The operational management of offshore wind farms includes inspection and maintenance (I&M) of the wind turbine support structures. These activities are complex and influenced by numerous uncertain factors that affect their costs. The uncertainty in the I&M costs should be considered in decision value analyses performed to optimize I&M strategies for the turbine support structures. In this paper, we formulate a probabilistic parametric model to describe I&M costs for the common case in which a wind farm is serviced and maintained using a workboat-based strategy. The model is developed based on (a) interviews with a wind farm operator, engineering consultants, and operation and maintenance engineers, as well as (b) scientific literature. Our methodology involves deriving the probabilistic models of the cost model parameters based on intervals representing a subjective expert opinion on the foreseeable ranges of the parameter values. The probabilistic cost model is applied to evaluate the total I&M costs, and a sensitivity analysis is conducted to identify the main cost drivers. The model can be utilized to optimize I&M strategies at the component, structural system, and wind farm level. To illustrate its potential use, we apply it in a numerical study in which we optimize I&M strategies at the structural system level and identify and demonstrate a simplified approach of capturing uncertain I&M costs in the optimization. The simplified approach is generalized and made available for maintenance cost optimization of offshore wind turbine structures. KW - Inspection KW - Maintenance KW - Turbine support structures KW - Offshore wind KW - Costs PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-626144 DO - https://doi.org/10.5194/wes-10-461-2025 SN - 2366-7443 SN - 2366-7451 VL - 10 IS - 2 SP - 461 EP - 481 PB - Copernicus Publications CY - Göttingen AN - OPUS4-62614 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Meng, Xiangmeng A1 - Bachmann, Marcel A1 - Yang, Fan A1 - Rethmeier, Michael T1 - Toward prediction and insight of porosity formation in laser welding: A physics-informed deep learning framework N2 - The laser welding process is an important manufacturing technology for metallic materials. However, its application is often hindered by the occurrence of porosity defects. By far, an accurate prediction of the porosity defects and an insight into its formation mechanism are still challenging due to the highly nonlinear physics involved. In this paper, we propose a physics-informed deep learning (PIDL) framework by utilizing mechanistic modeling and experimental data to predict the porosity level during laser beam welding of aluminum alloys. With a proper selection of the physical variables (features) concerning the solidification, liquid metal flow, keyhole stability, and weld pool geometry, the PIDL model shows great superiority in predicting the porosity ratio, with a reduction of mean square error by 41 %, in comparison with the conventional DL model trained with welding parameters. Furthermore, the selected variables are fused into dimensionless features with explicit physical meanings to improve the interpretability and extendibility of the PIDL model. Based on a well-trained PIDL model, the hierarchical importance of the physical variables/procedures on the porosity formation is for the first time revealed with the help of the Shapley Additive Explanations analysis. The keyhole ratio is identified as the most influential factor in the porosity formation, followed by the downward flow-driven drag force, which offers a valuable guideline for process optimization and porosity minimization. KW - Laser beam welding KW - Physics-informed deep learning KW - Porosity prediction KW - Feature fusion KW - Hierarchical importance PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-624708 DO - https://doi.org/10.1016/j.actamat.2025.120740 VL - 286 SP - 1 EP - 13 PB - Elsevier B.V. AN - OPUS4-62470 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Konert, Florian A1 - Nietzke, Jonathan A1 - Grimault de Freitas, Tomás A1 - Rhode, Michael A1 - Sobol, Oded A1 - Böllinghaus, Thomas T1 - Investigation of resistance to gaseous hydrogen of a longitudinal weld seam in a X65 pipeline using the hollow specimen technique N2 - The constantly increasing demand for renewable energy sources leads to the necessity of transporting large amounts of hydrogen. Since pipelines enable a cost-effective way for the distribution of gaseous hydrogen, the interaction of hydrogen and the pipeline materials must be carefully investigated as hydrogen can cause a degradation of the mechanical properties under certain conditions. Especially welds, which are assumed to be more susceptible to the degradation enhanced by hydrogen, are of great interest. The aim of this study is to investigate the effect of gaseous hydrogen on the mechanical properties of an X65 pipeline, and the longitudinal submerged arc welding (SAW) welded joint. The tests are conducted using the hollow specimen technique on two types of specimens: one extracted from the base material (BM) and the other extracted as a cross-weld (CW) specimen consisting of BM and weld seam. The specimens are charged in situ under a pressure of 60 bar and tested using slow strain rate (SSR) tensile tests with a nominal strain rate of 10−5 s−1. The properties obtained of specimens tested in hydrogen atmosphere are compared to the properties of comparable specimen in inert argon atmosphere as a reference. The performed tests showed a decrease of the reduction of area (RA) from 72% in inert atmosphere to 52% in hydrogen atmosphere for the CW specimen and a decrease from 73% in inert atmosphere to 51% for the BM. Metallographic analyses showed the crack initiation between fine-grained heat-affected zone (FGHAZ) and BM for the specimens tested in hydrogen atmosphere as well as for the reference specimens. This leads to the conclusion that the location of the crack initiation does not change due to the presence of gaseous hydrogen. KW - Hydrogen KW - Hollow specimen technique KW - Pipeline KW - SSRT KW - Hydrogen embrittlement KW - Cross-weld specimen PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-624658 DO - https://doi.org/10.1007/s40194-025-01953-3 SN - 0043-2288 SN - 1878-6669 VL - 69 IS - 3 SP - 861 EP - 870 PB - Springer CY - Berlin AN - OPUS4-62465 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Wiehle, Philipp A1 - Härder, Michelle A1 - Strangfeld, Christoph T1 - Quantification of moisture content in earth block masonry under natural climatic conditions N2 - The aim of this study is to accurately predict the moisture content in earth block masonry exposed to natural climatic conditions, which is a key factor in assessing its load-bearing capacity. Nuclear magnetic resonance relaxometry and humidity sensor measurements were carried out to quantify the moisture content. In addition, a customised test setup was developed to determine the capillary water absorption of earth blocks. This approach takes into account the deceleration of water absorption due to the swelling of clay minerals and organic additives, which leads to realistic transport coefficients in the hygroscopic range. This allows the moisture content of earth block masonry to be predicted accurately. With regard to the moisture behaviour of typical exterior wall constructions in living spaces, it was found that the equilibrium moisture content in earth block masonry is always lower than 65 % relative humidity, which corresponds to the permissible limit of the recently published German design standard for load-bearing earth block masonry. KW - Earth block masonry KW - NMR relaxometry KW - Hygrothermal simulation KW - Load-bearing capacity KW - Moisture content KW - Embedded humidity sensors PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-623518 DO - https://doi.org/10.1016/j.conbuildmat.2024.139513 VL - 459 SP - 1 EP - 10 PB - Elsevier Ltd. AN - OPUS4-62351 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Bernardy, Christopher A1 - Habib, Abdel Karim A1 - Kluge, Martin A1 - Schalau, Bernd A1 - Kant, Hanjo A1 - Schulze, Marcel A1 - Orchini, Alessandro T1 - Large-scale investigations of the thermal radiation of hydrogen jet flames N2 - For industrial applications dealing with hydrogen, the definition of safety distances and the assessment of possible hazards emanating from releases is mandatory. Since hydrogen is usually stored and transported under pressure, one scenario to be considered is the momentum driven release of hydrogen from a leakage with subsequent ignition. In this scenario, the emitted heat radiation from the resulting jet flame to the surroundings has to be determined to define adequate safety distances. For hydrocarbon flames, different jet flame models are available to assess the hazards resulting from an ignited jet release. Since hydrogen flames differ from hydrocarbon flames in their combustion behavior, it has to be checked if these models are also applicable for hydrogen. To evaluate the accuracy of these models for hydrogen jet flames, tests with a horizontal outlet at large-scale are carried out at the BAM Test Site for Technical Safety (BAM-TTS). Herein, the flame geometry and the heat radiation at defined locations in the surroundings are recorded for varying release parameters such as release pressure (currently up to max. 250 bar), mass flow (up to max. 0.175 kg/s) at an outlet diameter of 30 mm (with an upstream nozzle of 7.7 mm). The challenge here is the characterization of the flame geometry in an open environment and its impact on the thermal radiation. Existing heat radiation data from the literature are mostly based on unsteady outflow conditions. For a better comparability with the steady state jet flame models, the experiments presented here are focused on ensuring a constant mass flow over the release duration (currently 120 s) to obtain a stationary jet flame. In addition, stationary outflow tests with hydrocarbons (methane) were also carried out, which are intended to serve as reference tests for checking flame models based on hydrocarbon data. The comparison of the flame geometry shows that hydrogen jet flames with the same outlet mass flow have a greater flame length (average deviation of 15 %) but a smaller flame diameter than methane jet flames (average deviation of 17 %). Conclusions regarding thermal radiation show that the proportion of total combustion energy emitted as thermal radiation is lower for hydrogen (x_rad= 0.04–0.09) than for methane (x_rad = 0.06–0.1). A comparison of the surface emissive power (SEP) of the jet flame shows a SEP range of 7 kW/m2-15 kW/m2 for hydrogen and 3 kW/m2 - 9,5 kW/m2 for methane. KW - Hydrogen KW - Release KW - Thermal radiation KW - Jet flame KW - Radiant heat fraction PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-622891 DO - https://doi.org/10.1016/j.jlp.2024.105491 SN - 1873-3352 VL - 94 SP - 1 EP - 6 PB - Elsevier B.V. AN - OPUS4-62289 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 - Schumacher, Julia T1 - CRISPR-Cas9 in der Materialforschung - Den gesteinsbesiedelnden Pilzen auf der Spur T1 - CRISPR-Cas9 in materials research - On the trail of rock-inhabiting fungi N2 - Das mikroskopische Leben auf exponierten Oberflächen ist genügsam und kooperativ. Gesteinsbesiedelnde schwarze Pilze, Grünalgen und Cyanobakterien unterstützen einander in der Eroberung von Felsen, Mauern, Denkmälern, Dächern, Fassaden und Sonnenkollektoren. Bedeutend sind die schwarzen Pilze als Gesteinszerstörer und Biofilmbildner. Ihre massiven Zellwände und ihr langsames Wachstum machen sie stresstolerant und fordern zugleich die experimentelle Forschung heraus. In der Materialforschung können Biofilme erwünscht oder unerwünscht sein. Biofilme auf Fassaden können das Innenstadtklima positiv beeinflussen, während sie auf einem Marmordenkmal unwillkommen sind. Ohne tieferes Verständnis der angepassten Mikroben ist weder ihre Bekämpfung noch ihre gezielte Förderung auf Materialien möglich. Hier treffen sich Genetik und Materialforschung: Die CRISPR-Cas9-Technologie ermöglicht es, die Genome der Pilze für funktionale Analysen zu editieren, um die Mechanismen der Materialbesiedlung und Materialschädigung zu entschlüsseln. N2 - Rock-inhabiting black fungi are adapted to the harsh life on rocks in deserts and release minerals from the rocks. The same adaptations enable these fungi to colonize man-made surfaces such as monuments, building facades and solar systems. Black fungi are often associated with phototrophic microorganisms. The slow growth and the melanized cell walls, which protect the fungi from extreme environmental infuences, render molecular biological and genetic engineering methods diffcult, which is why little is known about the biology of these fungi. Knufa petricola was selected to understand the processes of material colonization and damage with the help of adapted methods such as CRISPR-Cas9-mediated genome editing. KW - Knufia petricola KW - Schwarze Pilze KW - Bioflme KW - Genomeditierung KW - Pigmente KW - Multiplexing KW - Resistenzkassette KW - Transformanten KW - Knufia petricola KW - Black fungi KW - Biofilms KW - Pigments KW - Genome editing KW - Multiplexing KW - Resistance cassette KW - Transformants PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-620500 DO - https://doi.org/10.11576/biuz-7595 SN - 0045-205X SN - 1521-415X N1 - Volltext (PDF) in deutsch und englisch - Full text (PDF) in German and English VL - 54 SP - 41 EP - 50 PB - Verband Biologie, Biowissenschaften und Biomedizin in Deutschland (VBiO) CY - München AN - OPUS4-62050 LA - mul AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Tobias, Charlie A1 - Gehrenkemper, Lennart A1 - Bernstein, Thomas A1 - Schlau, Sven A1 - Simon, Fabian A1 - Röllig, Mathias A1 - Meermann, Björn A1 - von der Au, Marcus T1 - Development of a fully automated slurry sampling introduction system for GF-AAS and its application for the determination of cadmium in different matrices N2 - element analysis, offering high sensitivity and precision. However, its effectiveness is limited by sample preparation challenges for solid samples like soils and microplastics. Traditional methods include sample preparation, such as digestion, which is time-consuming and involves reagents, like acids, contributing to measurement uncertainty and higher carbon footprints. Slurry sampling allows direct analysis of suspensions, offering a more efficient alternative. However, maintaining suspension stability is challenging, requiring robust autosampler systems to streamline the process and enhance analytical performance. Results: We present a novel autosampler extension for slurry sample introduction into GF-AAS. This system ensures suspension stability with a stirring device and closed vessels to prevent evaporation and contamination, incorporating a cooling unit to reduce solvent and analyte losses. It installs and removes in minutes without additional connections. Validation with cadmium analysis in BAM-U110 (Soil) and BAM-H010 (ABS) showed high reliability. For BAM-U110 (Soil), we achieved recovery rates of 94 % ± 13 % in water suspension. The recovery rate for BAM-H010 (ABS) was 104 % ±11 % in acetonitrile suspension. These results demonstrate the system’s robustness, versatility, and accuracy for different matrices. Significance: The autosampler extension helps solve key problems in trace element analysis of solid samples, making the process faster and more accurate. It works well with complex materials, making it useful for areas like microplastic or nanoparticle analysis. This improvement also helps meet regulations for monitoring environ mental and polymer samples, offering a reliable and flexible tool for high-throughput analysis with fewer errors. KW - Slurry AAS KW - Soil KW - Cd PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-618531 DO - https://doi.org/10.1016/j.aca.2024.343460 SN - 0003-2670 VL - 1335 SP - 1 EP - 7 PB - Elsevier BV AN - OPUS4-61853 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kalbe, Ute A1 - Piechotta, Christian A1 - Bandow, Nicole T1 - Comparing PFAS analysis in batch leaching and column leaching tests N2 - Laboratory leaching tests are tools to assess the mobility of environmental contaminants released from granular materials. Comparative leaching tests were performed using four PFAS-contaminated soils whose concentration patterns of 10 selected perfluoroalkyl and polyfluoroalkyl substances (PFAS) differed due to the two types of contamination sources. This study aimed to evaluate the equivalence of two usual laboratory-scale leaching test procedures, batch and column percolation tests, at liquid-to-solid ratios (L/S) of 2 l/kg, which is the current practice within the German assessment framework, and 10 l/kg (relevant for some EU regulations such as the landfill directive). The differences between the replicates of leaching tests investigating PFAS were smaller for column percolation tests than for batch tests, probably mainly due to the greater sample size and the better representativeness of the sample portion analyzed. It was observed that batch tests overestimate the release of shorter-chain PFAS, whereby the effect was greater with carboxylic than with sulfonic acids. Currently, the limits of detection of analyses given by the DIN standard with regard to PFCA and PFSA in soils are partly not sufficient to detect very low contents, whereas the detection of selected PFCA and PFSA in eluates is more sensitive, in accordance with the available standards. This results in limitations when calculating mass balances. KW - PFAS KW - Leaching KW - Column percolation test KW - Batch test KW - Soil PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-618187 DO - https://doi.org/10.1007/s11356-024-35510-0 SN - 1614-7499 VL - 31 IS - 57 SP - 65233 EP - 65251 PB - Springer Science and Business Media LLC AN - OPUS4-61818 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Hirahara, Kenta A1 - Bonse, Jörn A1 - Krüger, Jörg A1 - Weise, Matthias A1 - Ermilova, Elena A1 - Schusterbauer, Robert A1 - Unterreiner, Andreas-Neil A1 - Hertwig, Andreas T1 - A multi-method study of femtosecond laser modification and ablation of amorphous hydrogenated carbon coatings N2 - e present a study on femtosecond laser treatment of amorphous hydrogen-containing carbon coatings (a-C:H). The coatings were deposited on silicon wafers by a plasma-assisted chemical vapour deposition (PA-CVD), resulting in two different types of material with distinct properties (referred to as “absorbing” and “semi-transparent” coatings in the following). The samples were laser-treated with single fs-laser pulses (800 nm center wavelength, 35 fs pulse duration) in the ablative regime. Through a multi-method approach using topometry, Raman spectroscopy, and spectroscopic imaging ellipsometry, we can identify zones and thresholds of diferent fuence dependent efects and have access to the local dielectric function. The two coating materials react signifcantly diferent upon laser treatment. We determined the (non-ablative) modifcation threshold fuence for the absorbing coating as 3.6 × 10−2 Jcm−2 and its ablation threshold as 0.22 Jcm−2. The semi-transparent coating does not show such a low-fuence modifcation but exhibits a characteristic interference-based intra-flm ablation mechanism with two distinguishable ablation thresholds at 0.25 and 0.28 Jcm−2, respectively. The combination of tailored layer materials and correlative imaging spectroscopic methods delivers new insights into the behaviour of materials when treated with ultrashort-pulse laser radiation KW - Amorphous Hydrogenated Carbon Coatings KW - Correlative Imaging Measurement Techniques KW - Hybrid Metrology KW - Imaging Spectroscopy KW - Spectroscopic Ellipsometry KW - Ultra-short Pulse Laser Materials Processing PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-617829 DO - https://doi.org/10.1007/s00339-024-07980-z VL - 130 IS - 12 SP - 1 EP - 17 PB - Springer Science and Business Media LLC AN - OPUS4-61782 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Nordholt, Niclas A1 - Sobisch, Lydia-Yasmin A1 - Gödt, Annett A1 - Lewerenz, Dominique A1 - Schreiber, Frank T1 - Heterogeneous survival upon disinfection underlies evolution of increased tolerance N2 - Disinfection is important to limit the spread of infections, but failure of disinfection may foster the evolution of antimicrobial resistance in bacteria. Persisters are phenotypically tolerant subpopulations that survive toxic stress longer than susceptible cells, leading to failure in treatments with antimicrobials and facilitating resistance evolution. To date, little is known about persistence in the context of disinfectants. The aim of this study was to investigate the influence of persisters on disinfection and to determine the consequences of disinfectant persistence for the evolution of increased tolerance to disinfectants. Disinfection kinetics with high temporal resolution were recorded for Escherichia coli exposed to the following six disinfectants: hydrogen peroxide (H2O2), glutaraldehyde (GTA), chlorhexidine (CHX), benzalkonium chloride (BAC), didecyldimethylammonium chloride (DDAC), and isopropanol (ISO). A mathematical model was used to infer the presence of persisters from the time–kill data. Time–kill kinetics for BAC, DDAC, and ISO were indicative of persisters, whereas no or weak evidence was found for H2O2, GTA, and CHX. When subjected to comparative experimental evolution under recurring disinfection, E. coli evolved increased tolerance to substances for which persisters were predicted (BAC and ISO), whereas adaptation failed for substances in which no persisters were predicted (GTA and CHX), causing extinction of exposed populations. Our findings have implications for the risk of disinfection failure, highlighting a potential link between persistence to disinfectants and the ability to evolve disinfectant survival mechanisms. IMPORTANCE: Disinfection is key to control the spread of infections. But the application of disinfectants bears the risk to promote the evolution of reduced susceptibility to antimicrobials if bacteria survive the treatment. The ability of individual bacteria to survive disinfection can display considerable heterogeneity within isogenic populations and may be facilitated by tolerant persister subpopulations. Using time–kill kinetics and interpreting the data within a mathematical framework, we quantify heterogeneity and persistence in Escherichia coli when exposed to six different disinfectants. We find that the level of persistence, and with this the risk for disinfection failure, depends on the disinfectant. Importantly, evolution experiments under recurrent disinfection provide evidence that links the presence of persisters to the ability to evolve reduced susceptibility to disinfectants. This study emphasizes the impact of heterogeneity within bacterial populations on disinfection outcomes and the potential consequences for the evolution of antimicrobial resistances. KW - Antimicrobial resistance KW - Bacteria KW - Standardization KW - Biocides PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-615566 DO - https://doi.org/10.1128/spectrum.03276-22 SN - 2165-0497 VL - 12 IS - 12 SP - 1 EP - 11 PB - American Society for Microbiology CY - Birmingham, Ala. AN - OPUS4-61556 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Andrés Arcones, Daniel A1 - Weiser, M. A1 - Koutsourelakis, P.-S. A1 - Unger, Jörg F. T1 - Model bias identification for Bayesian calibration of stochastic digital twins of bridges N2 - Simulation-based digital twins must provide accurate, robust, and reliable digital representations of their physical counterparts. Therefore, quantifying the uncertainty in their predictions plays a key role in making better-informed decisions that impact the actual system. The update of the simulation model based on data must then be carefully implemented. When applied to complex structures such as bridges, discrepancies between the computational model and the real system appear as model bias, which hinders the trustworthiness of the digital twin and increases its uncertainty. Classical Bayesian updating approaches aimed at inferring the model parameters often fail to compensate for such model bias, leading to overconfident and unreliable predictions. In this paper, two alternative model bias identification approaches are evaluated in the context of their applicability to digital twins of bridges. A modularized version of Kennedy and O'Hagan's approach and another one based on Orthogonal Gaussian Processes are compared with the classical Bayesian inference framework in a set of representative benchmarks. Additionally, two novel extensions are proposed for these models: the inclusion of noise-aware kernels and the introduction of additional variables not present in the computational model through the bias term. The integration of these approaches into the digital twin corrects the predictions, quantifies their uncertainty, estimates noise from unknown physical sources of error, and provides further insight into the system by including additional pre-existing information without modifying the computational model. KW - Gaussian process KW - KOH KW - Bayesian updating KW - Digital twins KW - Uncertainty quantification PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-615519 DO - https://doi.org/10.1002/asmb.2897 SN - 1526-4025 N1 - This work was supported by “C07 - Data driven model adaptation for identifying stochastic digital twins of bridges” from the Priority Program (SPP) 2388/1 “Hundred plus” of the German Research Foundation (Deutsche Forschungsgemeinschaft, DFG) - Project number 501811638. VL - 417 IS - 3 SP - 1 EP - 26 PB - Wiley CY - Chichester AN - OPUS4-61551 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Gugin, Nikita A1 - Yusenko, Kirill A1 - King, Andrew A1 - Meyer, Klas A1 - Al-Sabbagh, Dominik A1 - Villajos Collado, José Antonio A1 - Emmerling, Franziska T1 - Lighting up industrial mechanochemistry: Real-time in situ monitoring of reactive extrusion using energy-dispersive X-ray diffraction N2 - Mechanochemistry is an environmentally friendly synthetic approach that enables the sustainable production of a wide range of chemicals while reducing or eliminating the need for solvents. Reactive extrusion aims to move mechanochemistry from its conventional gram-scale batch reactions, typically performed in laboratory ball mills, to a continuous, large-scale process. Meeting this challenge requires in situ monitoring techniques to gain insights into reactive extrusion and its underlying processes. While the effectiveness of in situ Raman spectroscopy in providing molecular-level information has been demonstrated, our study uses energy-dispersive X-ray diffraction to monitor reactive extrusion in real time at the crystalline level. Our results provide previously unavailable control over the reactive extrusion process, promoting its perception as an industrially feasible green alternative to traditional solvent-based syntheses. KW - Mechanochemistry KW - Reactive extrusion KW - Green chemistry KW - In situ studies KW - Time-resolved in situ KW - TRIS KW - Synchrotron radiation KW - Scalable synthesis KW - Solid-state reactions KW - Reaction mechanisms PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-613969 DO - https://doi.org/10.1016/j.chempr.2024.07.033 VL - 10 IS - 11 SP - 1 EP - 16 PB - Elsevier B.V. AN - OPUS4-61396 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Vogel, Christian A1 - Roesch, Philipp A1 - Wittwer, Philipp A1 - Sommerfeld, Thomas A1 - Riedel, Maren A1 - Leube, Peter A1 - Kalbe, Ute A1 - Schoknecht, Ute A1 - Simon, Franz-Georg T1 - Per- and Polyfluoroalkyl Substances (PFAS) in Ski Waxes and Snow from Cross-Country Skiing in Germany - Comparative study of Sum Parameter and Target Analysis N2 - Per- and polyfluoroalkyl substances (PFAS) are often environmentally exposed via discharge through human consumer products, such as ski waxes. In our study we analyzed various ski waxes from the 1980s and 2020s, to determine both the sum parameter values total fluorine (TF), extractable organically bound fluorine (EOF), hydrolysable organically bound fluorine (HOF) as well as targeted PFAS analysis. This showed that modern high-performance waxes contain up to 6 % TF, but also PFAS-free labelled ski waxes contain traces of PFAS with EOF/HOF values in the low mg kg-1 range. With the ban of all fluorine-based waxes with the start of the 2023/2024 winter season this will probably change soon. Moreover, we applied our analysis methods to snow samples from a frequently used cross country ski trail (Kammloipe) in the Ore Mountain region in Germany, assessing the potential PFAS entry/discharge through ski waxes. Melted snow samples from different spots were analyzed by the adsorbable organically bound fluorine (AOF) sum parameter and PFAS target analysis and confirmed the abrasion of the ski waxes into the snow. Moreover, on a PFAS hotspot also soil samples were analyzed, which indicate that PFAS from the ski waxes adsorb after snow melting into the soil. KW - Combustion Ion Chromatography KW - Per- and Polyfluoroalkyl substances (PFAS) KW - Consumer Products PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-612760 DO - https://doi.org/10.1016/j.hazadv.2024.100484 VL - 16 SP - 1 EP - 5 PB - Elsevier B.V. AN - OPUS4-61276 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Böttcher, Nils A1 - Dayani, Shahabeddin A1 - Markötter, Henning A1 - Schmidt, Anita A1 - Kowal, J. A1 - Lu, Y. A1 - Krug von Nidda, Jonas A1 - Bruno, Giovanni T1 - Visualization of stepwise electrode decomposition in a nail penetrated commercial lithium-ion cell using low-temperature synchrotron X-ray computed tomography N2 - The transition towards zero carbon emissions in power generation hinges on the integration of efficient electrical energy storage systems, with lithium-ion batteries (LIBs) positioned as a pivotal technology. While generally safe, deviations in their operational guidelines due to manufacturing defects or misuse can lead to critical safety concerns, notably thermal runaway (TR) events. Internal short circuits (ISCs) are primary initiators of TR within LIBs. For abuse testing, ISCs are often triggered by nail penetration. This study explores the morphological changes and mechanisms underlying ISC-induced TR in LIBs using operando synchrotron X-ray computed tomography (SXCT) at subzero temperatures. A novel cryogenic setup was developed to control a stepwise temperature increase in the damaged sample while monitoring electrochemical characteristics and simultaneously enabling acquisition of high-resolution SXCT images. The findings reveal that conducting nail penetration at minus 80°C prevents immediate TR, enabling detailed analysis of subsequent structural and electrochemical behavior during controlled thawing. Thus, the initiation of TR processes at localized ISC sites has been observed, evidenced by voltage fluctuations and morphological changes, such as cathode material cracking and decomposition. These results underscore the importance of temperature control in mitigating TR risks and provide critical insights into the internal dynamics of LIBs under abusive conditions. The developed cryogenic SXCT methodology offers a powerful tool for non-destructive, high-resolution investigation of battery failure mechanisms, contributing to the enhancement of LIB safety. KW - Tomography KW - X-ray imaging KW - Lithium-ion battery PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-611327 DO - https://doi.org/10.1016/j.jpowsour.2024.235472 VL - 623 SP - 1 EP - 10 PB - Elsevier CY - New York, NY AN - OPUS4-61132 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Lorenzoni, Renata A1 - Cunningham, Patrick A1 - Fritsch, Tobias A1 - Schmidt, Wolfram A1 - Kruschwitz, Sabine A1 - Bruno, Giovanni T1 - Microstructure analysis of cement‑biochar composites N2 - The use of biochar as a concrete constituent has been proposed to reduce the massive carbon footprint of concrete. Due to the low density and complex porosity of biochar, microstructural analysis of Portland cement-biochar composites is challenging. This causes challenges to the improvement of the micro-scale understanding of biochar composite behavior. This work advances the microstructural understanding of Portland cement composites with 0, 5, and 25 volume percent (vol%) of cement replaced with wood biochar by applying common characterization techniques of mercury intrusion porosimetry (MIP), gas sorption, scanning electron microscopy, and isothermal heat flow calorimetry (HFC) in conjunction with 1H nuclear magnetic resonance (NMR) and micro-X-ray computed tomography (XCT) analysis techniques. The combination of these techniques allows a multi-scale investigation of the effect of biochar on the microstructure of cement paste. NMR and XCT techniques allow the observation and quantification of the pore space. HFC and MIP confirmed that biochar absorbs moisture and reduces the effective water-cement ratio. Gas sorption, MIP, and NMR shows that 5 vol% replacement does not significantly affect the gel and capillary pore structures. Results from XCT (supported by MIP and NMR) show that biochar can reduce the formation of larger pores. Importantly, XCT results suggest that biochar can act as a flaw in the microstructure which could explain reductions in the mechanical properties. Overall, the mechanical properties already analyzed in the literature are consistent with the microstructural changes observed, and these results highlight the need to carefully tailor the volume fraction of biochar to control its effect on the paste microstructure. KW - Cementitious materials KW - Biochar KW - Microstructure KW - Porosity KW - Pore size distribution PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-610900 DO - https://doi.org/10.1617/s11527-024-02452-5 VL - 57 SP - 16 EP - 175 PB - Springer AN - OPUS4-61090 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Durlo Tambara, Luís Urbano A1 - Hirsch, A. A1 - Dehn, F. A1 - Gluth, Gregor T1 - Carbonation resistance of alkali-activated GGBFS/calcined clay concrete under natural and accelerated conditions N2 - The carbonation resistance of alkali-activated materials (AAMs) is a crucial parameter for their applicability in concrete construction, yet the parameters influencing it are insufficiently understood to date. In the present study, the carbonation resistance of alkali-activated concretes with varying fractions of ground granulated blast furnace slag (GGBFS) and calcined clay (i.e., high, intermediate, and low Ca contents) were assessed under natural and accelerated conditions. Corresponding hardened AAM pastes were studied using X-ray diffraction, thermogravimetry, Raman microscopy, and mercury intrusion porosimetry. The carbonation resistance of the concretes at natural CO2 concentration depended principally on their water/(CaO + MgOeq + Na2Oeq + K2Oeq) ratio. The remaining variability for similar ratios was caused by differences between the pore structures of the AAMs. For concrete with favorable water/(CaO + MgOeq + Na2Oeq + K2Oeq) ratio and pore structure, the carbonation resistance was comparable to that of Portland cement concrete. The relationship between carbonation coefficients obtained under accelerated and natural conditions differed for concretes with high and low fractions of calcined clay, indicating that accelerated carbonation testing is less suitable to study the carbonation of low-Ca AAMs. KW - Alkali-activated materials KW - Carbonation KW - Calcined clay PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-610747 DO - https://doi.org/10.1016/j.conbuildmat.2024.138351 SN - 1879-0526 VL - 449 SP - 1 EP - 14 PB - Elsevier CY - Amsterdam AN - OPUS4-61074 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Grimault de Freitas, Tomás A1 - Konert, Florian A1 - Nietzke, Jonathan A1 - Krzysch, Zephanja A1 - Böllinghaus, Thomas A1 - Michler, Thorsten A1 - Wackermann, Ken A1 - Oesterlin, Heiner A1 - Tlili, Mohamed A1 - Ruchti, Peter A1 - Beitelschmidt, Denise A1 - Elsen-Humberg, Stephan A1 - Koenigs, Timo A1 - Systermans, Thomas A1 - Sobol, Oded T1 - Tensile testing in high-pressure gaseous hydrogen using the hollow specimen method N2 - Metallic materials, predominantly steels, are the most common structural materials in the various components along the hydrogen supply chain. Ensuring their sustainable and safe use in hydrogen technologies is a key factor in the ramp-up of the hydrogen economy. This requires extensive materials qualification, however, most of the accepted; and standardized test methods for determining the influence of gaseous hydrogen on metallic materials describe complex and costly procedures that are only available to a very limited extent worldwide. The hollow specimen technique is a simple, rapid, and economical method designed to overcome the limitations of the current methods for the qualification of metallic materials under high-pressure hydrogen gas. However, this technique is not yet standardized. The TransHyDE-H2Hohlzug project is presented in this article, along with the main steps required to optimize the hollow specimen technique. This includes closing knowledge gaps related to the specimen geometry, surface quality, and gas purity in dedicated working packages, thus contributing to a comprehensive standardization of the technique for tests in high-pressure hydrogen gas. KW - High-pressure Gaseous Hydrogen KW - Hydrogen Embrittlement KW - Tensile Testing KW - Hollow Specimen Technique PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-610557 DO - https://doi.org/10.1557/s43577-024-00776-9 VL - 49 SP - 1 EP - 9 PB - Springer Nature AN - OPUS4-61055 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Wen, Keqing A1 - Gorbushina, Anna A1 - Schwibbert, Karin A1 - Bell, Jérémy T1 - Microfluidic platform with precisely controlled hydrodynamic parameters and integrated features for generation of microvortices to accurately form and monitor biofilms in flow N2 - Microorganisms often live in habitats characterized by fluid flow, and their adhesion to surfaces in industrial systems or clinical settings may lead to pipe clogging, microbially influenced corrosion, material deterioration, food spoilage, infections, and human illness. Here, a novel microfluidic platform was developed to investigate biofilm formation under precisely controlled (i) cell concentration, (ii) temperature, and (iii) flow conditions. The developed platform central unit is a single-channel microfluidic flow cell designed to ensure ultrahomogeneous flow and condition in its central area, where features, e.g., with trapping properties, can be incorporated. In comparison to static and macroflow chamber assays for biofilm studies, microfluidic chips allow in situ monitoring of biofilm formation under various flow regimes and have better environment control and smaller sample requirements. Flow simulations and experiments with fluorescent particles were used to simulate bacteria flow in the platform cell for calculating flow velocity and direction at the microscale level. The combination of flow analysis and fluorescent strain injection in the cell showed that microtraps placed at the center of the channel were efficient in capturing bacteria at determined positions and to study how flow conditions, especially microvortices, can affect biofilm formation. The microfluidic platform exhibited improved performances in terms of homogeneity and robustness for in vitro biofilm formation. We anticipate the presented platform to be suitable for broad, versatile, and high-throughput biofilm studies at the microscale level. KW - Topographical pattern KW - E. coli KW - Fluorescence KW - Bacteria trapping KW - Particle velocimetry PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-610450 DO - https://doi.org/10.1021/acsbiomaterials.4c00101 SN - 2373-9878 VL - 10 IS - 7 SP - 4626 EP - 4634 PB - ACS Publ. CY - Washington, DC AN - OPUS4-61045 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Paul, Andrea A1 - Liestmann, Zoe A1 - Zaenker, Steffen A1 - Vogel, Kristin A1 - Broszies, Tanja A1 - Ostermann, Markus T1 - How reliable is the X‐ray fluorescence‐based differentiation between glass wool and rock wool and the age classification of rock wool? N2 - AbstractA prerequisite for the recycling of mineral wool is information about the type of material, that is, whether it is glass wool or rock wool. As mineral wool produced before the year 2000 can be potentially carcinogenic, it is furthermore important to distinguish between “old” and “new” wool when handling the material. Based on VDI 3492, it is possible to determine the material and, in the case of rock wool, the age by analyzing the mass fractions of eight oxides, which are the main components of mineral wool. This study presents the X‐ray fluorescence (XRF) analyses of 141 man‐made mineral fibers collected in Germany. Only in a few cases it was not possible to clearly assign the material type. In contrast, the identification of “old” and “new” rock wool posed a challenge as there were many borderline samples. Based on the available data, a chemometric model was developed that can classify “old” and “new” RW with a sensitivity of 93% and 89% and with a specificity of 100% in both cases. However, care must be taken when oxide contents are close to the specification limits. The reason for this mainly lies in the overlapping intervals of key oxides as suggested by VDI 3492, and, to a lesser extent, in the uncertainties typically occurring in the XRF‐based analysis of oxides. With this study, a comprehensive collection and evaluation of XRF data on mineral wool is made available, which can serve as a reference database for future users. KW - Mineral wool KW - RFA KW - Multivariate data analysis KW - VDI 3492 PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-610285 DO - https://doi.org/10.1002/xrs.3451 SN - 1097-4539 SP - 1 EP - 11 PB - Wiley CY - New York, NY AN - OPUS4-61028 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Grohmann, Maria A1 - Niederleithinger, Ernst A1 - Büttner, Christoph A1 - Buske, Stefan T1 - Application of iterative elastic reverse time migration to shear horizontal ultrasonic echo data obtained at a concrete step specimen N2 - The ultrasonic echo technique is broadly applied in non‐destructive testing (NDT) of concrete structures involving tasks such as measuring thickness, determining geometry and locating built‐in elements. To address the challenge of enhancing ultrasonic imaging for complex concrete constructions, we adapted a seismic imaging algorithm – reverse time migration (RTM) – for NDT in civil engineering. Unlike the traditionally applied synthetic aperture focusing technique (SAFT), RTM takes into account the full wavefield including primary and reflected arrivals as well as multiples. This capability enables RTM to effectively handle all wave phenomena, unlimited by changes in velocity and reflector inclinations. This paper concentrates on applying and evaluating a two‐dimensional elastic RTM algorithm that specifically addresses horizontally polarized shear (SH) waves only, as these are predominantly used in ultrasonic NDT of concrete structures. The elastic SH RTM algorithm was deployed for imaging real ultrasonic echo SH‐wave data obtained at a concrete specimen exhibiting a complex back wall geometry and containing four tendon ducts. As these features are frequently encountered in practical NDT scenarios, their precise imaging holds significant importance. By applying the elastic SH RTM algorithm, we successfully reproduced nearly all reflectors within the concrete specimen. In particular, we were capable of accurately reconstructing all vertically oriented reflectors as well as the circular cross sections of three tendon ducts, which was not achievable with traditional SAFT imaging. These findings demonstrate that elastic SH RTM holds the ability to considerably improve the imaging of complex concrete geometries, marking a crucial advancement for accurate, high‐quality ultrasonic NDT in civil engineering. KW - Engineering KW - Finite-Difference Time Domain KW - Non-Destructive KW - Seismic KW - Migration KW - Ultrasonic-Echo Technique PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-608744 DO - https://doi.org/10.1002/nsg.12318 SN - 1569-4445 VL - 2024 SP - 1 EP - 22 PB - Wiley AN - OPUS4-60874 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Schilling, Markus A1 - Marschall, Niklas A1 - Niebergall, Ute A1 - Wachtendorf, Volker A1 - Böhning, Martin T1 - Characteristics of environmental stress cracking of PE-HD induced by biodiesel and diesel fuels N2 - In the context of the increasing effect of carbon dioxide emissions on the global climate biodiesel produced from renewable sources has emerged as a promising contender replacing fossil fuels, especially in long-range transport vehicles, using existing engines and infrastructure. High-density polyethylene is one of the prevailing materials for pipe and container applications for storage and transport of such fuels, both, from fossil and renewable resources. The contact with the respective fuels raises questions concerning material compatibility as biodiesel exhibits significant differences compared to conventional diesel fuel affecting its sorption and plasticization behavior in polyethylene. In this study, its behavior with respect to environmental stress cracking, considered one of the most frequent damage mechanisms leading to failure of polymer parts and packaging, was evaluated using the well-established Full Notch Creep Test. This approach allows for a detailed fracture surface analysis using imaging techniques, such as optical and laser scanning microscopy, as well as infrared spectroscopy. Comparing the environmental stress cracking behavior in standard surfactant solutions with that in biodiesel and diesel, respective crack propagation rates, showing different levels of acceleration, were determined and details of the underlying mechanisms could be revealed. Furthermore, the specific infrared absorption of the biodiesel’s ester functionality allows its semi-quantitative determination on the fracture surface of the tested specimens after failure. Thus, a preferred uptake of sorptive fluids in the fracture zone due to local morphological changes of the polyethylene could be directly evidenced by infrared spectroscopy. KW - Environmental stress cracking (ESC) KW - Full notch creep test (FNCT) KW - Confocal laser scanning microscopy (LSM) KW - Biodiesel KW - Diesel PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-608591 DO - https://doi.org/10.1016/j.polymertesting.2024.108547 SN - 0142-9418 VL - 138 SP - 1 EP - 16 PB - Elsevier Ltd. AN - OPUS4-60859 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Schröder, Jakob A1 - Fritsch, Tobias A1 - Luzin, Vladimir A1 - Ferrari, Bruno A1 - Simón-Muzás, Juan A1 - Evans, Alexander A1 - Bruno, Giovanni T1 - Impact of scan strategy on principal stresses in laser powder bed fusion N2 - Additive manufacturing techniques, such as laser powder bed fusion (PBF-LB), are well known for their exceptional freedom in part design. However, these techniques are also characterized by the development of large thermal gradients during production and thus residual stress (RS) formation in produced parts. In this context, neutron diffraction enables the non-destructive characterization of the bulk RS distribution. By control of the thermal gradients in the powder-bed plane by scan strategy variation we study the impact of in-process scan strategy variations on the microstructure and the three-dimensional distribution of RS. Microstructural analysis by means of electron backscatter diffraction reveals sharp microstructure transitions at the interfaces ranging from 100-200 µm. The components of the RS tensor are determined by means of neutron diffraction and the principal stress directions and magnitudes are determined by eigenvalue decomposition. We find that the distribution of RS in the powder-bed plane corresponds to the underlying scan strategy. When the alternating scan vectors align with the x- and y sample coordinate axes, the principal stress directions co-align. In the present geometry, nearly transverse isotropic stress states develop when the scan vectors are either aligned 45° between x and y or continuously rotated by 67° between each layer. KW - Additive Manufacturing KW - Laser Powder Bed Fusion KW - Electron Backscatter Diffraction KW - Neutron Diffraction KW - Residual Stress KW - Principal Stress PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-607910 DO - https://doi.org/10.1016/j.matdes.2024.113171 SN - 0264-1275 VL - 244 SP - 1 EP - 10 PB - Elsevier Ltd. AN - OPUS4-60791 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Mieller, Björn A1 - Hassine, Sahar Ben A1 - Töpfer, Jörg A1 - Priese, Christoph A1 - Bochmann, Arne A1 - Capraro, Beate A1 - Stark, Sebastian A1 - Partsch, Uwe A1 - Fresemann, Carina T1 - Ontology‐based Data Acquisition, Refinement, and Utilization in the Development of a Multilayer Ferrite Inductor N2 - A key aspect in the development of multilayer inductors is the magnetic permeability of the ferrite layers. Here, the effects of different processing steps on the permeability of a NiCuZn ferrite is investigated. Dry pressed, tape cast, and co‐fired multilayer samples are analyzed. An automated data pipeline is applied to structure the acquired experimental data according to a domain ontology based on PMDco (Platform MaterialDigital core ontology). Example queries to the ontology show how the determined process‐property correlations are accessible to non‐experts and thus how suitable data for component design can be identified. It is demonstrated how the inductance of co‐fired multilayer inductors is reliably predicted by simulations if the appropriate input data corresponding to the manufacturing process is used.This article is protected by copyright. All rights reserved. KW - Ontology KW - Ceramic multilayer KW - Data pipeline PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-605483 DO - https://doi.org/10.1002/adem.202401042 SN - 1527-2648 SP - 1 EP - 11 PB - Wiley-VCH CY - Weinheim AN - OPUS4-60548 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Simon, Patrick A1 - Schneider, Ronald A1 - Baeßler, Matthias A1 - Morgenthal, Guido ED - Cha, Young-Jin T1 - A Bayesian Probabilistic Framework for Building Models for Structural Health Monitoring of Structures Subject to Environmental Variability N2 - Managing aging engineering structures requires damage identification, capacity reassessment, and prediction of remaining service life. Data from structural health monitoring (SHM) systems can be utilized to detect and characterize potential damage. However, environmental and operational variations impair the identification of damages from SHM data. Motivated by this, we introduce a Bayesian probabilistic framework for building models and identifying damage in monitored structures subject to environmental variability. The novelty of our work lies (a) in explicitly considering the effect of environmental influences and potential structural damages in the modeling to enable more accurate damage identification and (b) in proposing a methodological workflow for model‐based structural health monitoring that leverages model class selection for model building and damage identification. The framework is applied to a progressively damaged reinforced concrete beam subject to temperature variations in a climate chamber. Based on deflections and inclinations measured during diagnostic load tests of the undamaged structure, the most appropriate modeling approach for describing the temperature‐dependent behavior of the undamaged beam is identified. In the damaged state, damage is characterized based on the identified model parameters. The location and extent of the identified damage are consistent with the cracks observed in the laboratory. A numerical study with synthetic data is used to validate the parameter identification. The known true parameters lie within the 90% highest density intervals of the posterior distributions of the model parameters, suggesting that this approach is reliable for parameter identification. Our results indicate that the proposed framework can answer the question of damage identification under environmental variations. These findings show a way forward in integrating SHM data into the management of infrastructures. KW - Verkehrsinfrastukturen KW - SHM KW - Model Updating KW - Environmental and Operational Variability KW - Damage Identification KW - Model Building PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-605027 DO - https://doi.org/10.1155/2024/4204316 SN - 1545-2255 VL - 2024 IS - 1 SP - 1 EP - 23 PB - Wiley AN - OPUS4-60502 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Sänger, Johanna C. A1 - Riechers, Birte A1 - Pauw, Brian Richard A1 - Maaß, Robert A1 - Günster, Jens T1 - Microplastic response of 2PP‐printed ceramics N2 - AbstractTwo‐photon polymerization (2PP) additive manufacturing (AM) utilizes feedstocks of ceramic nanoparticles of a few nanometers in diameter, enabling the fabrication of highly accurate technical ceramic design with structural details as small as 500 nm. The performance of these materials is expected to differ from conventional AM ceramics, as nanoparticles and three‐dimensional printing at high resolution introduce new microstructural aspects. This study applies 2PP‐AM of yttria‐stabilized zirconia to investigate the mechanical response behavior under compressive load, probing the influence of smallest structural units induced by the line packing during the printing process, design of sintered microblocks, and sintering temperature and thereby microstructure. We find a dissipative mechanical response enhanced by sintering at lower temperatures than conventional. The pursued 2PP‐AM approach yields a microstructured material with an increased number of grain boundaries that proposedly play a major role in facilitating energy dissipation within the here printed ceramic material. This microplastic response is further triggered by the filigree structures induced by hollow line packing at the order of the critical defect size of ceramics. Together, these unique aspects made accessible by the 2PP‐AM approach contribute to a heterogeneous nano‐ and microstructure, and hint toward opportunities for tailoring the mechanical response in future ceramic applications. KW - Manufacturing KW - Mechanical properties KW - Microstructure KW - Plasticity KW - Zirconia: yttria stabilized PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-605176 DO - https://doi.org/10.1111/jace.19849 SN - 1551-2916 VL - 107 IS - 10 SP - 6636 EP - 6645 PB - Wiley CY - Oxford AN - OPUS4-60517 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Dudziak, Mateusz A1 - Bhatia, Riya A1 - Dey, R. A1 - Falkenhagen, Jana A1 - Ullrich, M. S. A1 - Thomsen, C. A1 - Schartel, Bernhard T1 - Wastewater phosphorus enriched algae as a sustainable flame retardant in polylactide N2 - Revolutionizing our polymer industry for adaption to a sustainable carbon circular economy has become one of today’s most demanding challenges. Exploiting renewable resources to replace fossil-fuel—based plastics with biopolymers such as poly(lactic acid) (PLA) is inevitable while using waste streams as a raw material resource at least is promising. When it comes to using PLA as technical polymer, its high flammability must be addressed by flame retardants compatible with the thermoplastic processing of PLA and its compostability. This study proposes microalgae enriched with phosphorus from wastewater (P-Algae) as an elegant way towards a kind of sustainable organophosphorus flame retardant. The concept is demonstrated by investigating the processing, pyrolysis, flammability, and fire behavior of PLA/P-Algae, while varying the P-Algae content and comparing P-Algae with four alternative bio-fillers (phosphorylated lignin, biochar, thermally treated sewage sludge, and metal phytate) with different P-contents as meaningful benchmarks. KW - PLA KW - Flame Retardancy KW - Phosphorylated Algae KW - Wastewater flame retardants KW - Zink phytate KW - Phosphorylated lignin KW - Thermally treated sludge PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-604150 DO - https://doi.org/10.1016/j.polymdegradstab.2024.110885 SN - 1873-2321 SN - 0141-3910 VL - 227 SP - 1 EP - 11 PB - Elsevier Ltd. AN - OPUS4-60415 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Häßler, Dustin A1 - Mund, Maximilian A1 - Daus, Lars-Hendrik A1 - Hothan, Sascha A1 - Schaumann, Peter A1 - Schartel, Bernhard T1 - Durability of intumescent coatings and recommendations for test concepts for a working life of more than 10 years N2 - It is an essential requirement for all building products to ensure durability of their fire safety. Throughout the working life of products, intumescent coatings are aged by certain climatic factors. To predict a lifetime of several years, generally the behaviour of the intumescent coating is extrapolated based on accelerated artificial ageing. The established German and European procedures to assess the durability assume a working life of at least 10 years. For a longer period, additional evidence is required; yet the procedure and the specifications to justify this are not described. In addition to addressing this formal lack, from a scientific point of view it is necessary to investigate the degradation of intumescent coatings in detail and to propose a reliable test concept to assess durability for more than 10 years. This paper summarises the existing knowledge about the ageing of intumescent coatings. The results of various demanding weathering approaches are presented for two intumescent coatings tested in a joint research project. Moreover, formulations with a reduced amount of functionally relevant components were analysed to gain insight into the associated effects. Derived from these research results and knowledge, recommendations are proposed to assess the durability of intumescent coatings for more than 10 years based on a combination of verifications. KW - Ageing KW - Fire protection KW - Intumescent coating KW - Steel construction KW - Working life PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-603852 DO - https://doi.org/10.1016/j.firesaf.2024.104173 SN - 0379-7112 VL - 146 SP - 1 EP - 10 PB - Elsevier B.V. AN - OPUS4-60385 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Pavasarytė, Lina A1 - Azevedo do Nascimento, Allana A1 - Cysne Barbosa, Ana Paula A1 - Trappe, Volker A1 - Melo, Daniel T1 - Effects of particle size and particle concentration of poly (ethylene-co-methacrylic acid) on properties of epoxy resin N2 - Self-healing polymers have been developed to improve durability and reduce costs associated with maintenance during service. The addition of thermoplastics to thermosets to produce mendable polymers appears as a promising selfhealing technique. In this study, poly (ethylene-co-methacrylic acid) (EMAA) was added to epoxy resin and the effects of EMAA addition on epoxy properties were evaluated. Specimens with two different contents of thermoplastic and particles sizes were manufactured. A two-level full factorial experimental design was used to evaluate the effect of particle size and particle content on properties of epoxy modified with addition of EMAA. Tensile tests and dynamic mechanical analysis (DMA) were used and the evaluated responses were tensile strength, modulus of elasticity, and glass transition temperature (Tg). X-ray computed tomography (XCT) was used to investigate particle size and concentration after manufacturing. It was found that the particle concentration has greater effects on stress–strain behavior of epoxy while Tg was not significantly affected by neither of the analyzed entrance variables. KW - Fracture KW - Self-healing KW - Epoxy KW - Thermoplastic PY - 2024 DO - https://doi.org/10.1002/app.55677 SN - 0021-8995 SP - 1 EP - 14 PB - Wiley online library AN - OPUS4-60205 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Ladu, Luana A1 - Koch, Claudia A1 - Asna Ashari, Parsa A1 - Blind, K. A1 - Castka, P. T1 - Technology adoption and digital maturity in the conformity assessment industry: Empirical evidence from an international study N2 - Technological innovation and digitalization are transforming industries and organizations worldwide. Digital Maturity Models often serve as a reference point to monitor the digitalization progression through prescribed stages. Yet, little is still understood about (i) how a digital maturity model should be designed and deployed in a specific industry setting and (ii) the association between digital maturity and technology adoption. Building on extant literature and extensive interviews with industry experts, we first develop a digital maturity model in the context of the conformity assessment industry (a globally regulated industry responsible for assessing compliance of organizations with standards and regulations). Second, we implement the model and conduct a survey across 1447 organizations in 15 countries. Our findings reveal that the digital transformation journey of the industry progresses along five stages of maturity (with most organizations in the early/ intermediate stages of digital maturity) with distinctive patterns of technical and managerial practices across all stages. Adoption of technologies is (unsurprisingly) associated with higher digital maturity levels - albeit that association does not hold for complex technologies (such as Blockchain) and is impacted by country specifics (measured by the Digital Skills Gap Index). Our study provides insights into digital maturity and the adoption of technologies in an institutional environment that is highly regulated and conservative, in which high integrity of service provision is primary, and digitalization is a secondary focus of organizations. KW - Digital Maturity KW - Standardisation KW - Digital Maturity Scores KW - Technology Adoption KW - Digital Technologies PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-601930 DO - https://doi.org/10.1016/j.techsoc.2024.102564 SN - 0160-791X VL - 77 SP - 1 EP - 12 PB - Elsevier Ltd. AN - OPUS4-60193 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Junge, Florian A1 - Wittwer, Philipp A1 - Sommerfeld, Thomas A1 - Gehrenkemper, Lennart A1 - Zoister, Christian A1 - Nickl, Philip A1 - Koch, Matthias A1 - Meermann, Björn A1 - Haag, Rainer T1 - Adsorber Charge Dominates over Hydrophobic or Fluorophilic Functionalization in Influencing Adsorption of PFCA onto Polystyrene Resins N2 - A systematic series of industrial-relevant polystyrene-based anion exchange resins that are functionalized with hydro- or fluorocarbon chains are compared regarding their adsorption behavior toward perfluorocarboxylic acids (PFCA) in respect to their charge, chain length, and type of chain. The results clearly show the dominance of electrostatic interactions in the adsorption process as uncharged adsorber materials showed no adsorption at all. In contrast, the charged adsorber materials showed in general a PFCA removal of 80% to 30% over the experiment depending on effluent fraction. Unexpectedly, for perfluorobutanoic acid (PFBA) the highest removal rate is found with consistently >90%. Despite observing significant benefits in the adsorption of PFCA for fluoroalkylated adsorbers in comparison to their non-fluorinated counterparts, this effect of fluoroalkylation is comparatively small and can not be clearly attributed to fluorophilic interactions between the fluoroalkyl chains. These findings help clarifying that the introduction of fluorocarbon moieties in adsorber materials is not necessary in order to remove fluorocarbon molecules from the environment. KW - PFAS KW - Remediation KW - Adsorption KW - Fluorophilic interactions PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-601883 DO - https://doi.org/10.1002/admi.202400199 SN - 2196-7350 SP - 1 EP - 10 PB - John Wiley & Sons CY - Hoboken, New Jersey, USA AN - OPUS4-60188 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Silbernagl, Dorothee A1 - Szymoniak, Paulina A1 - Tavasolyzadeh, Zeynab A1 - Sturm, Heinz A1 - Topolniak, Ievgeniia T1 - Multiphoton lithography of interpenetrating polymer networks for tailored microstructure thermal and micromechanical properties N2 - Multiphoton lithography (MPL), an emerging truly 3D microfabrication technique, exhibits substantial potential in biomedical applications, including drug delivery and tissue engineering. Fabricated micro-objects are often expected to undergo shape morphing or bending of the entire structure or its parts. Furthermore, ensuring precise property tuning is detrimental to the realization of the functionality of MPL microstructures. Herein, novel MPL materials based on interpenetrating polymer networks (IPNs) are presented that effectively combine the advantages of acrylate and epoxy systems. IPNs with varying component ratios are investigated for their microfabrication performance and structural integrity with respect to thermal and micromechanical properties. A variety of high-resolution techniques is applied to comprehensively evaluate IPN properties at the bulk, micron, and segmental levels. This study shows that the MPL laser scanning velocity and power, photoinitiator content, and multi-step exposure can be used to tune the morphology and properties of the IPN. As a result, a library of 3D MPL IPN microstructures with high 3D structural stability and tailored thermal and micromechanical properties is achieved. New IPN microstructures with Young’s moduli of 3–4 MPa demonstrate high-to-fully elastic responses to deformations, making them promising for applications in morphable microsystems, soft micro-robotics, and cell engineering. KW - Interpenetrating polymer network KW - Multiphoton lithography KW - Atomic force microscopy KW - Intermodulation AFM KW - Fast scanning calorimetry PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-600593 DO - https://doi.org/10.1002/smll.202310580 SN - 1613-6810 SP - 1 EP - 12 PB - Wiley-VCH CY - Weinheim AN - OPUS4-60059 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Henning, Ricky A1 - Sturm, Patrick A1 - Keßler, S. A1 - Gluth, Gregor ED - Lothenbach, B. ED - Wieland, E. ED - Altmaier, M. T1 - Influence of salt aggregate on the degradation of hybrid alkaline cement (HAC) concretes in magnesium chloride-rich saline solution simulating evaporite rock N2 - Concretes produced from salt aggregate and hybrid alkaline cements, an alkali-activated slag/fly ash blend, or a Portland cement were exposed to a magnesium chloride-rich saline solution ([Mg2+] = 3.6 m, [Cl−] = 8.3 m), representing a solution formed after contact of surface water with evaporite rock (rock salt) in a nuclear waste repository. The hydration and deterioration of the concretes were studied with X-ray diffraction, thermogravimetric analysis, pH mapping and permeability measurements. The results show that calcium silicate hydrate (C-S-H) or sodium-substituted calcium aluminium silicate hydrate (C-N-A-S-H) and Friedel's salt were the major reaction products in the concretes prior to exposure to the saline solution. During exposure to the saline solution, increasing amounts of C-S-H/C-N-A-S-H dissolved, and gypsum and a secondary AFm phase formed. The durability of the concretes improved with increasing amounts of Portland clinker in the cements, due to the associated differences in permeability and chemical resistance. Nevertheless, a massive increase of permeability occurred for all concretes, likely caused by crack formation due to the formation of gypsum from anhydrite in the salt aggregate. Thus, the behavior of the concretes differed from, and was more complex than, the behavior of plain cement pastes. T2 - Joint 6th International Workshop on Mechanisms and Modelling of Waste/Cement Interactions (JCCW 2023) CY - Prague, Czech Republic DA - 20.11.2023 KW - Nuclear waste repository KW - Evaporite rock KW - Magnesium chloride brine KW - Concrete KW - Hybrid alkaline cement PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-599928 DO - https://doi.org/10.1016/j.apgeochem.2024.106027 SN - 0883-2927 SN - 1872-9134 VL - 168 SP - 1 EP - 14 PB - Elsevier AN - OPUS4-59992 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -