TY - CONF A1 - Grandel, Jonas T1 - Fine-tuning universal interatomic potentials for phonon properties without catastrophic forgetting N2 - Accurate phonon predictions are essential for evaluating material stability and thermal behavior. Traditional DFT-based methods are computationally intensive, driving interest in faster, machine-learning-based alternatives. In this work, we fine-tune the machine learning interatomic potential MACE-MP-0b3 (https://arxiv.org/abs/2401.00096) to improve the prediction of harmonic phonons and thermal properties. A key challenge is the need for highly accurate force calculations. While fine-tuning can enhance phonon accuracy, it may reduce generalizability to other properties. Despite this, our study shows that fine-tuned models can accurately predict phonon properties (including renormalization of imaginary phonons) at the same time as volume-dependent properties like the bulk modulus. We fine-tune the base model using small sets of rattled structures and introduce a novel fine-tuning method, benchmarking it against existing techniques. These results suggest that refined MACE-based universal potentials are a promising path for efficient and accurate phonon modeling. All implementations are included in the equitrain training code (https://github.com/BAMeScience/equitrain). T2 - Psi-k Konferenz CY - Lausanne, France DA - 25.08.2025 KW - Machine Learning KW - MACE KW - Phonon KW - Thermal properites PY - 2025 AN - OPUS4-64010 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Walterbos, Luc T1 - Double trouble: exploring the chemical landscape of halide double perovskites N2 - Halide Double Perovskites (HDPs) are an emerging class of materials with chemical formula A2BB’X6 with possible applications in photovoltaics, X-ray detection, sensing, photocatalysis and spintronics.. However, with more than 40,000 potential HDP compositions, much of the chemical landscape remains unexplored. We have generated a database of spin-polarized, hybrid functional (HSE06) electronic structure data of all HPDs with A=Cs that are predicted to be stable based on a tolerance-factor analysis. Our high-throughput workflow also consists or a chemical bonding and orbital projection analysis based on LOBSTER (ww.cohp.de), leading to a comprehensivedatabase of electronic, magnetic and chemical bonding properties of >2700 HDP compositions, which can serve as a starting point for material design and discovery via interpretable machine learning techniques, which we use to identify unexpected trends and relations in the chemical landscape. T2 - Psi-k 2025 CY - Lausanne, Swiss DA - 25.08.2025 KW - Materials design KW - Halide perovskite KW - Halide double perovskite KW - High-throughput KW - Hybrid functional PY - 2025 AN - OPUS4-64009 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Rhode, Michael T1 - Component-test for determination of welding residual stresses and their effect on stress relief cracking in thick-walled welds N2 - Controlling the residual stress level during welding of creep-resistant Cr-Mo-V steels is crucial to avoid so called stress relief cracking (SRC) during post weld heat treatment (PWHT) of large-scale components. In the present study, a laboratory scale test specimen (slotted sample with 400 mm width, 400 mm length and 25 mm thickness) was used to simulate thick-walled component welds made of 13CrMoV9-10. The aim was to identify the level and distribution of residual stresses to evaluate the suitability of the specimen for laboratory based SRC testing. High restraint was ensured by the specimen geometry with a narrow welding gap in the center. This gap was filled by multi-layer submerged arc welding. Two specimens were welded with identical parameters and compared in the as-welded state and after PWHT (705 °C for 10 h). Neutron diffraction was used to determine the residual stresses in the weld metal, the heat-affected zone (HAZ) and the base material at different depths longitudinal, transverse, and normal to the welding direction. The experiments were performed on the former instrument E3 of the research reactor BER II of Helmholtz-Zentrum Berlin (HZB), Germany. Complementarily, laboratory X-ray diffraction was applied to characterize the surface residual stresses. In the welded condition, especially in the weld metal and the adjacent HAZ, the longitudinal residual stresses reached values of up to 1,000 MPa to 1,200 MPa due to the increasing strength and hardness of the CrMoV-material during welding. The conducted welding experiments revealed that way higher residual stresses in the welded joint have to anticipated before the PWHT is performed than it was expected in advance. This demonstrated the necessity of suitable component-like welding tests as they must ensure realistic mechanical stiffness (hindered shrinkage of welding joint by slotted self-restraint sample) and heat dissipation conditions (definition of minimum welding joint thickness vs. welding process-specific heat input). T2 - FEMS Euromat 2025 - 18th European Congress and Exhibition on Advanced Materials and Processes CY - Granada, Spain DA - 15.09.2025 KW - Component test KW - Submerged arc welding KW - Post weld heat treatment KW - Residual stresses KW - Neutron diffraction PY - 2025 AN - OPUS4-64161 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Ryll, Tom William T1 - In-situ analysis of nucleation processes – case study: calciumsulfate N2 - In this project we investigate nucleation pathways by utilizing synchrotron-XRD and running a case-study on calcium sulfate and its polymorphs. To accomplish this, we developed a modular automation setup for reactions in solution to run synthesis and control reaction conditions. So far we successfully characterized the recycling process of gypsum (CaSO4*2H2O) and are now investigating the formation of anhydrite (CaSO4*0H2O) as well as possible applications for the automation setup and analysis. T2 - SALSA Make & Measure 2025 CY - Berlin, Germany DA - 10.09.2025 KW - Recycling KW - Gypsum KW - Synchrotron-X-ray-diffraction KW - Raman-spectroscopy KW - Automation PY - 2025 AN - OPUS4-64135 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Melzer, Michael T1 - The temperature DCC exposed N2 - The DAkkS-accredited calibration laboratory of the German Federal Institute for Materials Research and Testing (BAM) has established valid XML digital calibration certificates (DCCs) for calibrations of resistance thermometers within the scope of its accreditation. Hence, all necessary information according to ISO/IEC 17025 and the DKD-R 5-1 calibration rule is provided in a machine-readable and machine-interpretable form. Furthermore, we actively participate in the definition of general and community-specific good practice requirements for the DCC of temperature quantities as technical specifications, hosted by the German Calibration Service (DKD). In this contribution the entire XML source code of a DCC from a Pt 100 thermometer calibration will be exposed and discussed. The DCC was automatically generated using a self-implemented middleware that is compiling the metadata (i.e. customer-, order-, item- and method data) and combines it with the measured calibration data and influence conditions into a process- and lab-specific DCC template. Since it was issued as an accredited calibration certificate, the validated and authorized DCC is also equipped with the novel digital accreditation symbol to form an `eAttestation´. This advanced electronic seal with a qualified certificate was recently piloted with the German national accreditation body (DAkkS), and, after successful validation by the receiver, verifies the active accreditation status of the issuing body at the time of sealing (authorization). As it also provides all other functionalities of an electronic seal, (i.e. data integrity and authenticity), it can fully replace a digital signature on accredited DCCs. The presented temperature DCC architecture fully complies to the latest good practice definitions of the DKD and thus represents a level 4 DCC according to the utility model for machine interpretability of DCCs. This also includes basic and quantity-specific refType definitions that are linked to an online refType repository to harmonize these key semantic providing elements across other DCC-issuing laboratories. The paper and also its conference poster will not represent a general introduction and motivation for the DCC itself. It rather addresses more detailed aspects of good practice, especially for DCCs from temperature quantity calibrations and may stimulate in-depth discussions between DCC experts from the providing, utilizing and accrediting points of view. The work was performed within the national QI-Digital initiative of the German Federal Ministry for Economic Affairs and Climate Action, T2 - Global Industrie CY - Lyon, France DA - 11.03.2025 KW - Calibration KW - Digital Calibration Certificate KW - E-Attestation KW - Digital Metrology KW - QI-Digital PY - 2024 AN - OPUS4-64177 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Reinsch, Stefan T1 - Robot-assisted compositional screening in the System Na2O-Al2O3-B2O3-SiO2 N2 - The system Na2OB2O3SiO2 (NBS) is the basis of many industrial glass applications and therefore one of the most studied systems at all. Glass formation is possible over a wide compositional range, but the system also contains ranges of pronounced phase separation and crystallization tendency. Even small addition of Al2O3can change this behavior essentially. As the Na2OAl2O3B2O3SiO2 (NABS) system is also known as the basis for glasses in strength-relevant applications, the behavior during the transition from the NBS system to the NABS system is of interest. Therefore, some small step melt series in these systems were studied using the robotic glass melting system at the Federal Institute for Materials Research and Testing (BAM, Division Glasses). For these series the small step changes of glass transition temperature, crystallization behavior as well as glass density were studied. Additionally, experimental data were compared with their modeled counterparts. T2 - 98. Glastechnische Tagung CY - Goslar, Germany DA - 26.05.2025 KW - Sodium alumino boro silicate glasses KW - Glass transition temperature KW - Density KW - Robotic melting PY - 2025 AN - OPUS4-64076 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Evans, Alexander T1 - AGIL Project - Microstructure development in additively manufactured metallic components: from powder to mechanical failure N2 - Overview of the concept of the AGIL Project, work packages and Prior published work from BAM on the subject T2 - Challenges in Additive Manufacturing: Innovative Materials and Quality Control CY - BAM, Berlin-Adlershof, Germany DA - 12.09.2018 KW - AGIL KW - Additive manufacturing PY - 2018 AN - OPUS4-46100 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schmidt, Jonathan T1 - Near-real-time in-situ powder bed anomaly detection using machine learning algorithms for high-resolution image analysis in PBF-LB/M N2 - In-situ captured visual images of the laser powder bed fusion process (PBF-LB/M) provide valuable insights into process dynamics. Automatic analysis of after-recoating images using machine learning algorithms enables the detection of process deviations to reduce scrap production. However, current industrial monitoring systems for PBF-LB/M are limited by low image resolution. While higher resolutions enable the system’s ability to capture smaller features, they increase storage and computational demand. Edge devices offer a solution by enabling near-real-time, on-premises image analysis within the machine and company network. In this study, high-resolution after-recoating images, captured with a spatial resolution of 17 µm/pixel and an image size of 9344 x 7000 pixels, were processed on an Nvidia Jetson Orin NX16 edge device. The images were downscaled, and anomaly detection algorithms were used to identify regions of interest for segmentation and classification at full resolution. To address computational constraints, state-of-the-art anomaly detection algorithms were evaluated and an appropriate downscaling factor for the on-edge implementation was determined. The EfficientAD algorithm achieved promising results, detecting anomalies within an inference time of less than 10 seconds. The presented framework enables anomaly detection with a maximum delay of one layer. This lays the foundation for the future development of near-real-time intervention in the PBF-LB/M process. T2 - ISAM 2025 – 6th International Symposium on Additive Manufacturing CY - Dresden, Germany DA - 21.05.2025 KW - Additive manufacturing KW - Image processing KW - In-situ monitoring KW - Powder bed fusion PY - 2025 AN - OPUS4-63231 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Selleng, Christian T1 - Effect of 90°C thermal treatment on Ultra-High Performance Concrete N2 - Ultra High Performance Concrete (UHPC) is characterized by high strength and high durability. This is achieved by an optimized grain size distribution, especially within fine grains, and addition of superplasticizer, which allow the reduction of the water/cement ratio in the cement paste and thereby the increase of the density of UHPC. Thermal treatment, i.e. curing at elevated temperature and pressure, contributes to a further increase of compressive strength. The aim of the presented study was to analyze the effect of thermal treatment at 90 ◦C and atmospheric pressure on UHPC samples. Varying factors were the age of the samples when heat treatment started (initial storage time), the duration of heat treatment and the type of heat treatment. It was applied in three ways: 1. treated without any protection, 2. sealed in plastic foil and 3. treated in hot water. Afterwards the samples were analyzed with respect to their mechanical properties and their phase composition. Furthermore, the weight (water absorption) of the samples was observed over 28 days and was correlated with the strength test results. The development of strength depends on the combination of initial storage time and the duration of heat treatment and is also influenced by the type of thermal treatment. The highest compressive strengths have been observed by implementing the hot water treatment. Thereby the weight of the samples increase due to additional absorbed water. This enables an increased hydration of cement clinker inducing a higher strength. T2 - GeoBerlin 2015: Dynamic Earth - from Alfred Wegener to today and beyond CY - Berlin, FU Berlin DA - 04.10.2015 PY - 2015 AN - OPUS4-34504 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Redmer, Bernhard A1 - Weise, Frank A1 - Ewert, Uwe A1 - Patitz, G. T1 - Kombinierter Einsatz zerstörungsfreier Prüfverfahren zur Bauzustandsanalyse antiker Baudenkmäler im Pergamonmuseum Berlin N2 - Zur Planung und Durchführung umfangreicher Sanierungs- und Umbaumaßnahmen im Pergamon-Museum Berlin bestand die Erfordernis einer Bauzustandsanalyse an antiken Baudenkmälern. Bestandsunterlagen waren unvollständig vorhanden bzw. fehlten. Hieraus ergab sich die Notwendigkeit des kombinierten Einsatzes zerstörungsfreier Prüftechnik. T2 - Jahrestagung Zerstörungsfreie Materialprüfung 2004 CY - Salzburg, Austria DA - 17.05.2004 KW - Baudenkmal KW - Bauzustandsanalyse KW - Radar KW - Radiografie KW - Videoskopie KW - Zerstörungsfreie Prüfung PY - 2004 AN - OPUS4-35531 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Voigt, Marieke T1 - Thermally treated UHPC: a durability study N2 - Ultra high performance concrete (UHPC) is known for its high compressive strength of more than 150 MPa and its high durability. Thermal treatment at 90°C can accelerate the strength development so that the 28-days-strength can be achieved immediately after the treatment and an additional increase up to 30 % in some cases. The reason for the strength development is an accelerated hydration of the clinker minerals and an intensified pozzolanic reaction leading to a denser microstructure. In previous research inhomogeneities in form of a zonation after unprotected thermal treatment were observed and analysed in respect to changes in the microstructure. This zonation is defined by a different microstructure in the core compared to the outer zone in the matter of porosity, mineral phase composition and a significant change in the potassium and sulphur concentration of the zones is measurable. To isolate different transport mechanisms responsible for these element distributions UHPC samples were thermally treated at 90 °C and the microstructure was investigated under dry conditions and after immersion in water to investigate the influence of dehydration during and rehydration after the thermal treatment on the microstructure. Through durability testing via water absorption, water vapour diffusion, permeability testing and sulfuric acid resistance transport mechanisms like diffusion, migration, capillary suction are under investigation in correlation with the microstructure analysis. For the microstructure analysis measurements with µXRF, mercury intrusion porosity, XRD and SEM were conducted. T2 - HiPerMat 2020 CY - Kassel, Germany DA - 11.03.2020 KW - UHPC KW - Thermal treatment KW - Zonation KW - Transport mechanism KW - Durability PY - 2020 AN - OPUS4-52372 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kilinc, Sefine T1 - Grinding method and oxidative aging of tire wear microplastics affect the fitness of the nematode C. elegans N2 - This study gives a first insight in the toxicological relevance of tire wear MP on soil invertebrates. Both grinding technique and aging method had an effect on the results of the particle size distribution, particle properties and toxicity tests. This outcome highlights the importance of oxidative and mechanical aging of tire wear when investigating effects on soil biota. In particular the demonstrated differences due to grinding method of the pristine material questions scientific practice in common toxicity tests. It is essential to implement realistic refernce material as well as standardized aging and handling procedures. T2 - Tire Emissions Research Conference 2024 CY - Munich, Germany DA - 04.12.2024 KW - Nematode C. elegans KW - Oxidative aging KW - Tire wear KW - Microplastics PY - 2024 AN - OPUS4-62361 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Rübner, Katrin T1 - Porenstruktur von Beton mit Recyclingzuschlägen N2 - Recyclingzuschläge (rezyklierte Gesteinskörnungen, Betonsplitt) werden großtechnisch aus dem Material, das beim Abbruch von Betonbauwerken anfällt, hergestellt. Sie bestehen zu mehr als 90% aus Altbeton. Die Wiederverwendung dieser Materialien zur Herstellung von neuen hochwertigen Beton erfordert umfangreiche Kenntnisse über ihre betontechnologischen und chemisch-physikalischen Eigenschaften. Zwei unterschiedliche Recyclingzuschläge und die damit hergestellten Betone wurden im Vergleich zu einem Referenzbeton mit natürlichen Zuschlägen gleicher Sieblinie untersucht. T2 - Tag der offenen Tür der BAM CY - Berlin, Germany DA - 19.06.2004 PY - 2004 AN - OPUS4-11432 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Rübner, Katrin T1 - Mikrostruktur von hochfestem Beton N2 - Hochfeste Betone werden durch die Zugabe puzzolanischer Zusatzstoffe (Microsilica, Flugasche) und die Reduzierung des Wasser-Zement-Wertes bei gleichzeitiger Verwendung eines Fließmittels hergestellt. Diese Modifizierungen des Betons beeinflußen die Zusammensetzung und die Mikrostruktur seiner Mörtelmatrix. T2 - Tag der offenen Tür der BAM CY - Berlin, Germany DA - 19.06.2004 PY - 2004 AN - OPUS4-11431 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Ramge, Peter T1 - Einflüsse der Mischungszusammensetzung auf die Porenstruktur von Instandsetzungsmörteln N2 - Untersucht wurde der Einfluss der Applikationsart (konventionelle und gespritzte Herstellung, Wasserlagerung bis zur Prüfung), der Einfluss von Fasern (konventionelle Herstellung, Wasserlagerung bis zur Prüfung) und der Einfluss von Schwindreduzierern (konventionelle Herstellung, Luftlagerung bis zur Prüfung). T2 - XV. Workshop über die Charakterisierung von feinteiligen und porösen Festkörpern (Porotec-Workshop) CY - Bad Soden, Germany DA - 16.11.2010 PY - 2010 AN - OPUS4-22634 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Weise, Frank T1 - Influence of aggregate size on the damage potential of alkal-silica-reaction N2 - The poster shows new results on Alkali-Silica-Reaction (a damage mechanism of concrete). The influence of the aggregate size in the sand fraction is investigated, revealing that different types of aggregate behave in a different way. T2 - 15th International Conference of Alkali Aggregate Reaction in Concrete (ICAAR 2016) CY - Sao Paulo, Brazil DA - 03.07.2016 KW - Alkali-silica-reaction KW - Building materials KW - Concrete KW - Durability PY - 2016 AN - OPUS4-36951 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Rübner, Katrin T1 - Use of municipal solid waste incinerator bottom ash as aggregate concrete N2 - Modern municipal solid waste incinerator plants produce bottom ashes, which are used in building industry, especially as base course in road constructions. Because of a highly sophisticated reprocessing technique, the ashes Show a relatively stable composition, comparatively well defined properties and environmentally relevant Parameters below legal Limits. Due to its chemical and mineralogical characteristics, the bottom ash can in principle be used as Aggregate in the production of normal strength concrete. However, if the ash contains concrete damaging components Recycling becomes problematic. To assess the use of municipal solid waste incinerator bottom ash (MSWI bottom ash) as Aggregate in concrete, different additionally treated ashes were chemical and physical characterised. Furthermore, concrete specimens with bottom ash as aggregates were produced and their Engineering properties were studied. T2 - EGU 2007 European Geosciences Union General Assembly 2007, Symposium Energy, Resources and the Environment ERE8 "Aggregates - the most widely used geological material" CY - Vienna, Austria DA - 15.04.2007 PY - 2007 AN - OPUS4-18949 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Herbst, Tristan T1 - Nachhaltiges Bauen mit Beton - Einsatz sekundärer Gesteinskörnungen N2 - Im Hinblick auf eine nachhaltige Entwicklung sollen nach dem KrW/AbfG der Rohstoffeintrag und der Abfallaustrag in den Lebensphasen eines Bauwerks durch weitgehende Verwertung von Sekundärrohstoffen (Reststoffen) möglichst gering gehalten werden. Ein Einsatz von Reststoffen wie Hausmüllverbrennungsaschen (MV-Aschen) im Betonbau kann potenziell einen wesentlichen Beitrag zur nachhaltigen Entwicklung leisten. T2 - 17. IBAUSIL CY - Weimar, Germany DA - 23.09.2009 PY - 2009 AN - OPUS4-19731 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Maultzsch, Matthias A1 - Kühne, Hans-Carsten T1 - Entwicklung von Betonen mit geringer Festigkeit für die Beurteilung von Instandsetzungssystemen im Wasserbau N2 - Die Regelwerke (RL SIB, ZTV-ING) setzen für die Instandsetzung mit Betoninstandsetzungssystemen vergleichsweise hochwertige Betonuntergründe voraus. Speziell bei älterenWasserbauwerken sind oftmals nur geringerfeste Betonuntergründe vorhanden für die es bis jetzt keine geeigneten und geprüften Instandsetzungssysteme gab. Grundlage für die Entwicklung solcher Systeme sind entsprechende Referenzbetone als Untergrundbeton für die Verbundkörperprüfung. T2 - Wissenschaftsrat CY - Berlin, Germany DA - 17.01.2006 PY - 2006 AN - OPUS4-12028 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kühne, Hans-Carsten T1 - Abschätzung der Druckfestigkeit von hochfestem Beton mit dem Rückprallhammer N2 - Ziel der Untersuchungen war es, herauszufinden ob die Druckfestigkeit hochfester Betone zerstörungsfrei mit dem Rückprallhammer PROCEQEQUOSCHMIDT durch Ermittlung des klassischen Rückprallwerts R in Kombination, mit einem aus der Untersuchung von Metallen bekannten neuen Messwert L mit ausreichender Sicherheit beschrieben werden kann. T2 - Wissenschaftsrat CY - Berlin, Germany DA - 17.02.2006 PY - 2006 AN - OPUS4-12029 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Rübner, Katrin T1 - Charakterisierung der Porenstruktur von ultrahochfestem Beton N2 - Ultrahochfeste Betone (UHPC) sind durch Druckfestigkeiten > 150 MPa und eine besonders hohe Dauerhaftigkeit gekennzeichnet. Ihre Herstellung gelingt durch die Optimierung der Mischungszusammensetzung, des Mischprozesses und der Nachbehandlung. Maßnahmen dazu bestehen in der Verwendung feinstgemahlener Zemente, puzzolanischer und inerter Feinststoffe, dem Einsatz gezielt ausgewählter grober und feiner Gesteinskörnungen, der Reduktion des Wasser/Bindemittel-Wertes bei Zugabe von Fließmitteln auf Polycarboxylat-Basis sowie einer Wärmebehandlung der Betone. Das Ziel dabei ist es, eine möglichst hohe Packungsdichte in der Bindemittelmatrix bei Ausbildung einer sehr gleichmäßigen und extrem dichten Gefügestruktur mit einem hohen Anteil an Calciumsilicathydrat-Phasen zu erreichen. Deshalb sind Untersuchungen zur Porosität und Porenstruktur ein wichtiger Bestandteil zur Materialcharakterisierung im Rahmen der Mischungsoptimierung. Die Ergebnisse der Mikrostrukturuntersuchungen werden im Vergleich zu denen an einem hochfesten Beton und einem Normalbeton betrachtet. T2 - XIII. Workshop über die Charakterisierung von feinteiligen und porösen Festkörpern CY - Bad Soden, Germany DA - 14.11.2006 PY - 2006 AN - OPUS4-14010 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Osterhus, Lennart T1 - Kieselsäurehaltiger Filterrückstand aus industrieller Abwasserbehandlung für den Einsatz als hydraulisches Bindemittel N2 - - 5.000 bis 10.000 t wasserhaltiger Filterrückstand (FR) entstehen jährlich pro Produzent bei der Neutralisation der Abwässer aus der Silicon- oder Kieselsäureherstellung - Anfall als fester, feuchter, schollenartiger Filterkuchen - Verwertung heute: Deponierung, Tagebauverfüllung -> ungenutzte Sekundärrohstoffquelle - Untersuchung der Einsatzmöglichkeiten der aufbereiteten Filterrückstände zur Eigenschaftsverbesserung zementgebundener Baustoffe analog der wohlbekannten Anwendung von hochdisperser Kieselsäure und Silicastaub T2 - GDCh-Tagung Bauchemie CY - Hamburg, Germany DA - 06.10.2011 PY - 2011 AN - OPUS4-24819 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Herbst, Tristan T1 - Integrated and holistic suitability assessment of recycling options for masonry rubble N2 - Behandelt den Bausektor und die Verarbeitsungsqualität T2 - European Geosciences Union (EGU) General Assembly 2012 CY - Vienna, Austria DA - 22.04.2012 PY - 2012 AN - OPUS4-25868 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Herbst, Tristan T1 - Verwertung kieselsäurehaltiger Filterrückstände in mineralischen Baustoffen N2 - - jährlicher Anfall von 5.000 bzw. 10.000 Tonnen wasserhaltiger Filterrückstände (FR) pro Produzent bei der Abwasser-Neutralisation aus der Kieselsäure- bzw. Chlorsilanherstellung (FR1, FR2) - heute: Deponierung, Tagebauverfüllung - ungenutzte Sekundärrohstoffquelle - Untersuchung möglicher Anwendungsbereiche für FR T2 - GDCh Tagung Bauchemie CY - Dübendorf, Switzerland DA - 11.10.2012 PY - 2012 AN - OPUS4-26673 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Makris, Ruben T1 - Crack Luminescence as innovative method for detection of fatigue damage N2 - Conventional methods of crack detection only provide a snapshot of the fatigue evolution at a specific location and in the moment of examination. The crack luminescence method realizes a clear visibility of the occurring cracks in loaded components during ongoing operation. Several different experiments show that due to the sensitive coating even the early stage of the crack formation can be detected what makes the crack luminescence helpful to determine the incipient crack opening behavior depending on load alternation. Due to the emitting of light under UV-radiation the crack gets clearly visible what makes continuous monitoring and automated crack detection possible. This can reduce costs and time needed for maintenance and inspection. T2 - Sensor +Test 2017 CY - Nuremberg, Germany DA - 30.05.2017 KW - Fatigue damage KW - Crack KW - Luminescence KW - Detection PY - 2017 AN - OPUS4-41839 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kruschwitz, Sabine T1 - Junior Research Group Materials Characterization and Informatics for Sustainability in Civil Engeneering (CE) N2 - Vorstellung der Themen der Nachwuchsgruppe "Materialcharakterisierung und -informatik für die Nachhaltigkeit im Bauwesen" von Prof. Sabine Kruschwitz (TU Berlin und BAM) T2 - Themenkonferenz Nachhaltiges Bauen CY - Berlin, Germany DA - 08.12.2022 KW - Recycling KW - NMR KW - Materialcharakterisierung KW - Data Science PY - 2022 AN - OPUS4-56648 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hirsch, T. T1 - Impact of autoclaving on the phase assemblage of Portland cement: Experiment and thermodynamic modelling N2 - Even after autoclaving for 2 weeks in the temperature range of 120 to 200 °C, CEM I paste with a water-to-cement ratio of 0.5 still contains some low-crystalline C-S-H. The conversion of low-crystalline C-S-H to crystalline is faster with increasing temperature. The observed low-crystalline and crystalline C-S-H phases (reinhardbraunsite, jaffeite) indicate that the samples have not reached equilibrium yet under these experimental conditions. However, there is a good agreement between experiment and thermodynamic modelling for the other solids indicating that the used datasets are suitable for this application. T2 - 16th International Congress on the Chemistry of cement 2023 - ICCC2023 CY - Bangkok, Thailand DA - 18.09.2023 KW - Zement KW - Thermodynamik KW - Phasenzusammensetzung KW - Mineralogie KW - Modellierung PY - 2023 UR - https://iccc2023.org AN - OPUS4-58967 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Falkenhagen, Jana T1 - Error margins in the Determination of Molar Mass and Oligomer Content of Polymers N2 - Size exclusion chromatography (SEC) is still the method of choice for determining the molar mass and molar mass distribution of macromolecules. It is a liquid chromatographic technique that separates molecules based on their size, respectively their hydrodynamic volume using a porous stationary phase that allows smaller molecules to pass through the pores while excluding larger molecules. The chromatogram from the size separation can be calibrated using polymers of known molar mass resulting in a relative molar mass distribution curve. From this distribution curve molar mass averages and the oligomer content (percentage of peak area smaller than 1000 g/mol and 500 g/mol) of polymers can be derived. The determination of oligomer content is important, because it is often used in regulatory contexts as a measure of small, mobile and potentially more toxic parts of the polymer. Polymer regulations are of increasing political and social importance. Regulations often set very narrow limits. SEC has rather large error margins of 10-20% for the molar mass determination performed in different laboratories or on different instruments. These variances are well known to all experts and users and have been investigated in several round robin tests in the past. These resulted in DIN and ISO standards which, in our opinion, no longer meet today's requirements. As far as we know, the margins of error in determining oligomer content have not yet been investigated. It is expected that the variation will be rather high. This is because it depends on many factors related to the experimental conditions (column sets used, solvent, temperatures, sample preparation) on the one hand, and the data evaluation mechanisms (choice of baseline and peak limits) on the other. In order to actually measure the error margins and to support this with actual data a round robin test has been performed from June to November 2024 with approx. 40 participating laboratories. Three different solvents were selected, namely THF, DMAc or DMF and water. The samples were selected together with all the experts, taking into account a wide range of practical aspects far from narrowly distributed standards: e.g higher distribution range, reduced solubility, included side components, copolymers and dispersions with gel content. In this contribution we will present the detailed concept of this round robin test and first results. T2 - SETAC Europe 35th Annual Meeting CY - Vienna, Austria DA - 11.05.2025 KW - Size exclusion chromatography KW - REACH KW - Polymers KW - Round Robin Tests PY - 2025 AN - OPUS4-63307 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Falkenhagen, Jana T1 - Limitations of SEC: Strategies for Improved Regulatory Polymer Analysis N2 - Polymers, composed of repeating units called monomers, exhibit a diverse range of properties, with molecular weight distribution (MWD) being particularly important for regulatory risk assessments. Size exclusion chromatography (SEC), or gel permeation chromatography (GPC), is the primary technique for MWD characterization, as detailed in OECD guidelines 118 and 119, along with DIN and ISO standards. However, SEC faces significant shortcomings that complicate the accurate determination of MWD and oligomer content. These limitations include the insolubility of certain polymers, crosslinking, and ultra-high molecular weight characteristics, which can exceed SEC's separation capabilities. The presence of salts or modifiers can further interfere with oligomer content determination, and the availability of appropriate SEC columns and calibration standards limits comparability across laboratories. To enhance SEC's reliability and applicability within regulatory frameworks, innovative methods and strategies are essential. Proposed solutions involve new sample preparation techniques, advanced data interpretation methods, and the establishment of standardized methodologies to promote harmonization. This is especially crucial in light of the expected Polymer REACh (PREACh) legislation, which aims to regulate polymer registration and risk assessment within the European market. Given the anticipated complexity of the registration process, which requires extensive data generation, proactive strategies are needed to address SEC's challenges. Currently, there are no viable alternatives for oligomer content determination, and the unique properties of polymers often necessitate tailored analytical approaches. Without new methodologies and guidelines, the polymer registration process could become burdensome and costly, jeopardizing important products and markets in the EU. Key areas for improvement include extending existing norms to cover a broader range of solvents, addressing high error margins in oligomer content determination, establishing harmonized approaches for dealing with side components, and providing clarity on measuring partially soluble polymers. In conclusion, addressing SEC's limitations through the development of comprehensive guidelines and harmonization is critical for ensuring accurate and efficient polymer analysis, ultimately facilitating smoother registration processes. T2 - SETAC Europe 35th Annual Meeting CY - Vienna, Austria DA - 11.05.2025 KW - Size exclusion chromatography KW - Polymers KW - REACH PY - 2025 AN - OPUS4-63309 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Epperlein, Nadja T1 - Influence of femtosecond laser produced nanostructures on biofilm growth on steel N2 - Large area periodic surface structures were generated on steel surfaces using 30-fs laser pulses at 790 nm wavelength. Two types of steel exhibiting a different corrosion resistance were used, i.e. a plain structural steel (corrodible) and a stainless steel (resistant to corrosion). Homogeneous fields of laser-induced periodic surface structures (LIPSS) were realized utilizing laser fluences close to the ablation threshold while scanning the sample under the focused laser beam in a multi-pulse regime. The nanostructures were characterized with optical and scanning electron microscopy. For each type of steel, more than ten dentical samples were laser-processed. These samples were subjected to microbial adhesion tests, investigating bacterial adhesion behavior on the laser structures in comparison to polished reference surfaces. Short term experiments (<24h) were carried out to determine initial biofilm development. E. coli as a typical bacterium representing pathogenic bacteria and Shewanella putrefaciens as metal corrosive bacterium were used for biofilm development analyses. Bacterial cell adhesion was determined microscopically after DAPI cell staining (DNA staining). Comparison of the coverage areas between nanostructured and polished surfaces revealed differences in cell adhesion behavior and biofilm structure. T2 - E-MRS 2016 Spring Meeting, Symposium C: "Laser-material interactions for tailoring future applications" CY - Lille, France DA - 02.05.2016 KW - Laser-induced periodic surface structures (LIPSS) KW - Femtosecond laser ablation KW - Biofilms KW - Steel PY - 2016 AN - OPUS4-36045 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Stroj, S. T1 - Laser-generated high wetting contrast surfaces for microbiological applications N2 - We demonstrate a 2D platform based on high contrast wetting patterns suitable for miniaturized microbiological assays. In principal, superhydrophilic spots are surrounded by a superhydrophobic surface area. The special structure of the superhydrophilic functional surface ensures that liquids, e.g. bacterial suspensions or biocide solutions, spread immediately and evenly on this surface without passing the wetting boundary. This feature allows a homogenous distribution of bacteria or chemical substances on well defined lateral dimensions. The superhydrophilic spots may also serve as substrate for bacterial biofilms. Due to the high wetting contrast and the fabrication process, it is possible to minimize the test areas as well as their distance to each other. We demonstrate the fabrication process of the high wetting contrast platform and also present a microbiological assay as an application example. Advantages of this platform are the use of low volumes and its potential of automated analysis. T2 - Biointerfaces International Conference CY - Zürich, Austria DA - 14.08.2018 KW - Biofilm KW - Bacterial growth KW - Laser structuring KW - Superhydrophobic surface KW - Superhydrophilic surface PY - 2018 AN - OPUS4-45863 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Zekhnini, Khalid T1 - Corrosion at metallic offshore constructions – Bundesanstalt für Materialforschung und -prüfung (BAM) N2 - In the maritime context of offshore operation, corrosion, in combination with the materials used, poses a particular challenge to ensure safe operation over long indefinite periods and to minimise susceptibility to failure. Until today, only a few corrosion protection systems have proven themselves for the interaction of efficiency, installation, and maintenance in the offshore sector. In addition, available corrosion test methods sometimes have major deficits about conclusions of the durability. Therefore, there is more research and development needed. The flagship project H2Mare of the Federal Ministry of Education and Research aims to enable the production of green hydrogen and PtX products at high seas. Research is being driven forward by the partners in four individual projects, where BAM is involved in two. In PtX-Wind, major kinds of corrosion attacks at offshore constructions are characterized and investigated, and suitable corrosion protection measures determined. In TransferWind, attention focusses on transferring scientific results into standardization. This poster at the H2Mare Conference 2023 presents an overview of the investigation methods and contribution of the department “Corrosion and Corrosion Protection”. T2 - H2Mare Conference 2023 CY - Frankfurt/Main, Germany DA - 12.06.2023 KW - Atmospheric Corrosion KW - Sea Water KW - Corrosion Testing KW - Offshore KW - Laboratory Container KW - Corrosion protecting system PY - 2023 AN - OPUS4-57838 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - von Rüden, H. T1 - Röntgen-Computertomographie (CT) für die Kulturguterhaltung N2 - Als bildgebendes und zerstörungsfreies Verfahren eignet sich die Röntgen-Computertomographie (CT) insbesondere bei der Untersuchung von Kunst- und Kulturgütern. Die für Werkstoffprüfung und Materialanalyse konzipierten CT-Anlagen bieten dank hoher Röntgenleistung die Möglichkeit zusätzlich zu Holz, Keramiken und Kunststoffen auch stark schwächende Materialien, wie bspw. Metalle, zu durchdringen. Für eine hohe räumliche Auflösung im unteren Mikrometerbereich (2-200µm) sorgen entsprechend ausgelegte CT-Anlagen. In der Bundesanstalt für Materialforschung und -prüfung (BAM) stehen mehrere solcher CT-Anlagen für unterschiedliche Fragestellungen sowie Probengrößen und - materialien zur Verfügung. Einige Beispiele aus den vergangenen Arbeiten der BAM veranschaulichen das große Potential dieser Untersuchungsmethode. Da bei einer CT-Messung in der Regel das gesamte Untersuchungsobjekt erfasst und in ein digitales Volumenmodell überführt wird, eröffnet sich für Archäologen und Restoratoren die Möglichkeit Untersuchungen hinsichtlich Materialzusammensetzung, Erhaltungszustand und Herstellungstechnik am virtuellen Objekt vorzunehmen, ohne die Originalsubstanz zu beeinträchtigen. Gegenüber der klassischen Radiografie, bei der nur eine zweidimensionale Abbildung erreicht wird, bietet die CT-Untersuchung die Möglichkeit innenliegende Strukturen dreidimensional zu erfassen. Die notwendige Bestimmung der Objektoberfläche erlaubt zudem die Erstellung eines Oberflächenmodells des untersuchten Gegenstandes. Damit lassen sich unter anderem mechanische Simulationen (Belastung, Durchbiegung, Durchströmung) durchführen. Der erzeugte Datensatz kann somit auch zur Herstellung eines Replikats im 3D-Druckverfahren genutzt werden. Anhand der Untersuchung der Mandoline von Smorsone wird gezeigt, wie eine CT-Messung durchgeführt wird und wie in dem anschließend rekonstruierten 3D-Datensatz mittels Koordinatenmesstechnik Maße (Abstände, Wandstärken, Winkel) exakt ermittelt werden können. T2 - Jahrestagung der Gesellschaft für Musikforschung CY - Berlin, Germany DA - 28.09.2022 KW - Mikro-CT KW - Bildverarbeitung KW - Holz KW - Bronze KW - ZfP PY - 2022 AN - OPUS4-56412 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Ulbricht, Alexander T1 - Do Microbes like Additively Manufactured Aluminium? First Details of a Corrosion Test using Sulphate-Reducing Bacteria N2 - Additively manufactured metals become relevant for industrial application. Although many studies on wet corrosion of these metals have been conducted, to the authors knowledge no study seems to contain microbiological corrosion (MIC). In the presented study an experiment was conducted on PBF-LB/AlSi10Mg to test this material's susceptibility for MIC. The tested specimen were analysed using Computed Tomography before and after the MIC experiment to enable a detailed characterisation the damage on the specimens' global and local level. A global reduction of material was observed. In addition, localised damage along process inherent features of the materials microstructure was observed. T2 - Beiratssitzung TF Umwelt CY - Berlin, Germany DA - 17.03.2025 KW - Computed Tomography KW - Additive Manufacturing KW - Biocorrosion KW - Sulphate-reducing Bacteria KW - Microbially influenced corrosion PY - 2025 AN - OPUS4-62772 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Merz, Benjamin T1 - Precise Position Detection for Repair of Gas Turbine Blades using PBF-LB/M N2 - Additive manufacturing (AM) technologies are becoming increasingly important, not only for the manufacture of parts, but also as repair technology that complement existing production technologies. Powder bed fusion of metals by laser beam (PBF-LB/M) combines the freedom in design with high achievable accuracy, making it ideal as a repair approach. However, there are still challenges in adapting process for repair applications. When mounting parts inside PBF-LB/M machines, their real position within the build volume is unknown. One goal of a repair process is to minimize the offset between the base component and the additively manufactured structure to reduce additional rework. For a minimum offset between component and additively manufactured structure, the actual position of the component has to be identified with high precision within the machine coordinate system (MCS). In this work a process setup is presented that allows the actual position of a gas turbine blade to be detected inside a PBF-LB/M machine. A high resolution camera with 65 megapixel is used for this purpose. The presented setup is implemented on a SLM 280 HL PBF-LB/M machine. In addition to the setup, a novel repair workflow using PBF-LB/M is presented. The developed setup and workflow consider inaccuracies in the component and camera mounting, as well as process inaccuracies. This includes keystone distortion correction by homography. The machine setup and workflow are used to repair a real gas turbine blade. Subsequently the offset between the turbine blade and the additivley manufactured structure is validated by 3D scanning the repaired part. The maximum offset is 160 µm. The presented approach can be extended to other geometries and PBF-LB/M machine manufacturers. The high-resolution camera approach is platform independent, which facilates the market penetration of PBF-LB/M repair processes. T2 - International Symposium Additive Manufacturing 2023 (ISAM 2023) CY - Dresden, Germany DA - 30.11.2023 KW - additive manufacturing KW - powder bed fusion of metals utilizing a laser beam KW - PBF-LB/M KW - hybrid repair KW - position detection KW - high-resolution camera PY - 2023 AN - OPUS4-59193 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Waske, Anja T1 - A unique authenticator for additively manufactured parts derived from 3D microstructural information N2 - Additive manufacturing (AM) is rapidly emerging from rapid prototyping to industrial production [1]. Thus, providing AM parts with a tagging feature that allows identification, like a fingerprint, can be crucial for logistics, certification, and anti-counterfeiting purposes since nearly any geometry can be produced by AM with stolen data or reverse engineering of an original product. However, the mechanical and functional properties of the replicated part may not be identical to the original ones and pose a safety risk [2]. Several methods are already available, which range from encasing a detector to leveraging the stochastic defects of AM parts for the identification, authentication, and traceability of AM components. The most prevailing solution consists of local process manipulation, such as printing a quick response (QR) code [3] or a set of blind holes on the surface of the internal cavity of hollow components. Local manipulation of components may alter the properties. The external tagging features can be altered or even removed by post-processing treatments. Integrating electronic systems [4] in AM parts can be used to identify and authenticate components with complex or customized geometries. However, metal-based AM, especially in powder bed fusion (PBF-LB/M) techniques, has a strong shielding effect that interferes with the communication between the reader and the transponder. Our work suggests a methodology for the identification, authentication, and traceability of AM components using microstructural features in AM components. We will show a workflow that includes analysing 3D micro computed tomography data and selecting a set number of voids that fulfil the identification criteria. We will show the results this workflow produces for a series of 20 Al-based cuboid samples with identical processing parameters and discuss their prospects and limitations. The workflow can help to establish a non-tamperable connection between an additively manufactured part and its digital data and hence link the physical and the digital world. T2 - MSE Konferenz CY - Darmstadt, Germany DA - 24.09.2024 KW - Additive Manufacturing KW - Fingerprint KW - Computed tomography PY - 2024 AN - OPUS4-62288 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Seifert, Lando T1 - Das Meerwasserlabor am Eidersperrwerk N2 - Das Meerwasserlabor (Laborcontainer) ist eine Remote-fähiges Elektrochemie-Labor mit entfeuchtungsfähiger Klimatisierung in dem eine Vielfalt an experimentellen Möglichkeiten besteht. Das Alleinstellungsmerkmal ist der Meerwasser-Bypass, durch den eine Besiedlung und Erhalt von Salzwasser- bzw. Brackwasserbewuchs (Bakterien, Algen, Tiere, Pilze, etc.) möglich ist. Der jährliche Verlauf der Meeresumwelt wird dadurch abgebildet. T2 - Leitprojekt H2Mare Verbundtreffen PtX-Wind & TransferWind CY - Frankfurt am Main, Germany DA - 05.12.2024 KW - Offshore Corrosion KW - Marine Corrosion KW - Corrosion KW - Green Hydrogen PY - 2024 AN - OPUS4-62054 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Fayet, G. T1 - First models to predict thermal decomposition properties of possible self-reactive substances based on industrial datasets N2 - Self-reactive substances are unstable chemical substances which can easily decompose and may lead to explosion. For this reason, their thermal stability properties are required within regulatory frameworks related to chemicals in order to assess their hazardous properties. Due to the fast development and availability of computers, predictive approaches like QSPR models are increasingly used in the evaluation process of hazardous substances complementary to experiments. In that context, the HAZPRED project (2015-2018) aimed to develop QSPR models to predict physical hazards of substances to fill the lack of knowledge on these hazardous substances quickly. An experimental campaign, based on 50 samples provided by Industrial producers, was carried out on potential self-reactive substances, for which no QSPR model already existed. Their heats of decomposition were characterized using differential scanning calorimetry in homogeneous experimental conditions. QSPR models were derived using the GA-MLR method (using a genetic algorithm and multi-linear regressions) using molecular descriptors calculated by Dragon software based on both 3D molecular structures from density functional theory (DFT) optimizations, to access three-dimensional descriptors, and SMILES codes, favoring the access to simpler models, requiring no preliminary quantum chemical calculations. All models respected the OECD validation guidelines for regulatory acceptability of QSPR models. They were tested by internal and external validation tests and their applicability domains were defined and analyzed. If improved models should be expected with larger database (and a better ratio between size and chemical diversity), these first models already represent a screening tool capable to access early reactive hazards. T2 - 19th International Workshop on Quantitative Structure-Activity Relationships in Environmental and Health Sciences CY - Online meeting DA - 07.06.2021 KW - QSPR KW - Self-reactive substances KW - Thermal decomposition PY - 2021 AN - OPUS4-53178 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Oster, Simon T1 - Multispectral in-situ monitoring of a L-PBF manufacturing process using three thermographic camera systems N2 - The manufacturing of metal parts for the use in safety-relevant applications by Laser Powder Bed Fusion (L-PBF) demands a quality assurance of both part and process. Thermography is a nondestructive testing method that allows the in-situ determination of the thermal history of the produced part which is connected to the mechanical properties and the formation of defects [1]. A wide range of commercial thermographic camera systems working in different spectral ranges is available on the market. The understanding of the applicability of these cameras for qualitative and quantitative in-situ measurements in L-PBF is of vital importance [2]. In this study, the building process of a cylindrical specimen (Inconel 718) is monitored by three camera systems simultaniously. These camera systems are sensitive in various spectral bandwidths providing information in different temperature ranges. The performance of each camera system is explored in the context of the extraction of image features for the detection of defects. It is shown that the high temporal and thermal process dynamics are limiting factors on this matter. The combination of different spectral camera systems promises the potential of an improved defect detection by data fusion. T2 - LASER SYMPOSIUM & ISAM 2021 CY - Online meeting DA - 07.12.2021 KW - Laser Powder Bed Fusion KW - Thermography KW - In-situ Monitoring KW - Defect detection PY - 2021 AN - OPUS4-54141 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Taparli, Ugur Alp T1 - Time- and space-resolved in situ LIBS measurements of chemical compositions during TIG-welding N2 - An in situ monitoring of chemical compositions in the weld pool and the heat affected zone (HAZ) can enable the control of the welding process through the regulation of the welding parameters, and thus can prevent possible weld defects. The most critical parameter for hot cracking -from a metallurgical point of view- is the chemical composition of the weld pool. Chemical composition can be measured and quantified during the welding process with the LIBS technique having the appropriate calibration measurements. T2 - ICWAM 2017 CY - Metz, France DA - 17.05.2017 KW - Chemical compositions KW - TIG-welding KW - In situ measurement KW - LIBS PY - 2017 AN - OPUS4-40313 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schmitt, Johannes T1 - Data acquisition system for single particle inductively coupled plasma mass spectrometry (spICP-MS) with nanosecond time resolution N2 - This study presents our data acquisition system prototype for single particle inductively coupled plasma mass spectrometry (spICP-MS) with nanosecond time resolution (nanoDAQ) and a matching data processing approach for time-resolved data in the nanosecond range. The system continuously samples the secondary electron multiplier (SEM) detector signal with a dwell time of approximately 2 ns and enables detection of gold nanoparticles (AuNP) as small as 7.5 nm with a commercial single quadrupole ICP-MS instrument. [1] Analysis of acquired transient data is based on the temporal distance between detector events and a derived ion event density. It was shown that the inverse logarithm of the distance between detector events is proportional to particle size. Also, the number of detector events per particle can be used to calibrate and determine the particle number concentration (PNC) of a nanoparticle dispersion. Particle-by-particle-based analysis of ion event density and other parameters derived from nanosecond time resolution show promising results. High data acquisition frequency of the systems allows recording of a statistically significant number of data points in 60 s or less, which leaves only the sample uptake and rinsing steps as remaining factors for limiting the total measurement time. T2 - 20th European Winter Conference on Plasma Spectrochemistry CY - Berlin, Germany DA - 02.03.2025 KW - ICP-MS KW - Instrumentation KW - Nano KW - Nanoparticle Characterization PY - 2025 AN - OPUS4-63599 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Rhode, Michael T1 - Component test for the assessment of hydrogen assisted cracking susceptibility of thick-walled submerged arc welded offshore steels N2 - Offshore wind turbines (OWT) are a key factor of the sustainable energy generation of tomorrow. The continuously increasing installation depths and weight of the OWTs require suitable foundation concepts like monopiles or tripods. Typically, mild steels like the S420ML are used with plate thicknesses up to several hundreds of mm causing high restraints in the weld joints. Due to the large plate thickness, submerged arc welding (SAW) with multiple wires is the state-of-the-art welding procedure. As a result of the very high stiffness of the construction, a certain susceptibility for time-delayed hydrogen-assisted cracking (HAC) may occur. The evaluation of crack susceptibility is very complex due to the component size and stiffness of real offshore structures. For this purpose, a near-component test geometry was developed to transfer the real stiffness conditions to laboratory (i.e., workshop) scale. The investigated mock-up, weighing 350 kg, comprised heavy plates (thickness 50 mm, seam length 1,000 m) joined by a 22-pass submerged arc weld. Additional stiffeners simulated the effect of high restraint or shrinkage restraint of the weld. Extreme scenarios of hydrogen absorption during welding were simulated via the use of welding fluxes in dry (HD < 5 ml/100g Fe) and moisture condition (HD > 15 ml/100g Fe). The residual stresses were determined by a robot X-ray diffractometer. Areas of critical tensile residual stress (at the level of the yield strength) were found in the weld metal and heat affected zone. To identify possible delayed cracking, the welds were tested by phased array ultrasonic testing (PAUT) after 48 h. Summarized, no significant occurrence of HAC was detected, indicating the high crack resistance of the welded joint, i.e., a suitable combination of base material, welding consumable and welding parameters. T2 - AJP 2023: 3rd International Conference on Advanced Joining Processes 2023 CY - Braga, Portugal DA - 19.10.2023 KW - Hydrogen assisted cracking KW - Submerged arc welding KW - Component test KW - NDT KW - Waiting time PY - 2023 AN - OPUS4-58672 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Agasty, Amit T1 - A Preliminary Study on the Scaling of RC Structures under Blasting Loading N2 - Current capabilities for full-scale field blast testing are highly resource intensive. Reliable small-scale experiments are an effective alternative. Characterization of the dynamic response and damage of RC elements to scaled blast loads was investigated in scaled-down field experiments. Spatially resolved information on the dynamic structural response to blast loading was obtained using distributed fiber optic acoustic sensing (DAS), acceleration sensors as well as piezoelectric pressure sensors. T2 - 46. Informationstagung Sprengtechnik CY - Siegen, Germany DA - 25.04.2025 KW - Explosives KW - Blast and scaling effects KW - Concrete PY - 2025 AN - OPUS4-62994 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Ryll, Tom William T1 - Researching automation of gypsum recycling N2 - This poster illustrates the recent work on a setup for automated in-situ analysis of gypsum recycling processes. Analysis in synchrotron X-rays, Raman- and UV-vis spectroscopy are made possible with this compact and mobile setup. First results from Raman spectroscopy on the conversion of gypsum to bassanite in hypersaline solutions are presented and future plans on optimization are formulated. T2 - ANAKON 2025 CY - Leipzig, Germany DA - 10.03.2025 KW - Recycling KW - Automation KW - Synchrotron-X-ray-diffraction KW - Raman-spectroscopy KW - Gypsum PY - 2025 AN - OPUS4-62706 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Ryll, Tom William T1 - Researching automation of gypsum recycling N2 - This poster illustrates first successful experiments of recycling gypsum in hypersaline solutions with quantification via Raman-spectroscopy. To furhter enhancements include an automation setup, that was developed to gain in-situ measurements and open a pathway for batch-conversions and upscaling. T2 - BESSY@HZB User Meeting CY - Berlin, Germany DA - 12.12.2024 KW - Recycling KW - Gypsum KW - Raman-spectroscopy KW - Automation PY - 2024 AN - OPUS4-62292 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Stawski, Tomasz T1 - Processing of calcium sulfate in brines N2 - Calcium sulfate hemihydrate (CaSO4·0.5H2O), also known as bassanite or "plaster of Paris", serves as a precursor for the production of gypsum (dihydrate, CaSO4·2H2O), widely used in construction. Currently, ~200 MT of calcium sulfate are consumed annually. Bassanite is obtained from gypsum through a solid-state thermal treatment in kilns at temperature ranging from 150 °C to 200 °C. We introduce a more efficient and sustainable method (T < 100 ºC) that enables the direct, rapid, and reversible conversion of gypsum to bassanite using reusable high salinity aqueous solutions (brines with c[NaCl] > 4 M). These transformations are controlled by the properties of the solution, offering extensive opportunities for precise manipulation of crystal formation and recycling of gypsum waste. T2 - BESSY User Meeting 2024 CY - Berlin, Germany DA - 12.12.2024 KW - Gypsum PY - 2024 AN - OPUS4-62095 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Tielemann, Christopher T1 - Oriented Surface Crystallization N2 - Up to now, oriented surface crystallization phenomena are discussed controversially, and related studies are restricted to few glasses. For silicate glasses we found a good correlation between the calculated surface energy of crystal faces and oriented surface nucleation. Surface energies were estimated assuming that crystal surfaces resemble minimum energy crack paths along the given crystal plane. This concept was successfully applied by Rouxel in calculating fracture surface energies of glasses. Several oriented nucleation phenomena can be herby explained assuming that high energy crystal surfaces tend to be wetted by the melt. This would minimize the total interfacial energy of the nucleus. Furthermore, we will discuss the evolution of the microstructure and its effect on the preferred crystal orientation. T2 - 26th International Congress on Glass CY - Berlin, Germany DA - 03.07.2022 KW - Glass KW - Surface energy KW - Crystal orientation PY - 2022 AN - OPUS4-56074 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Waurischk, Tina A1 - Reinsch, Stefan A1 - Müller, Ralf A1 - Chen, Y.-F. A1 - Contreras Jaimes, A. T1 - Datengetriebener Workflow für die beschleunigte Entwicklung von Glas (GlasDigital) N2 - Das Projekt GlasDigital wurde im allgemeinen vorgestellt, sowie die einzelnen Zwischenstände der verschiedenen Arbeitspakete aller Projektpartner präsentiert. Die allgemeine Porjektvorstellung ist auf deutsch. Die Zwischenstände der Arbeitsinhalte sind auf englisch. T2 - PMD Vollversammlung CY - Berlin, Germany DA - 03.11.2022 KW - Oxidglas KW - Robotische Glasschmelzanlage KW - ML KW - Ontologie KW - Digitaler Zwilling KW - Bildanalyse PY - 2022 AN - OPUS4-56491 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Waurischk, Tina T1 - Data-driven Workflow for Accelerated Glass Development (GlasDigital) N2 - As part of a joint project involving the Fraunhofer Institute for Silicate Research (ISC), the Friedrich Schiller University of Jena, the Clausthal University of Technology and the Federal Institute for Materials Research and Testing (BAM), digital tools are to be created for the development of new types of glass materials. Current processes for the production of glasses with improved properties are usually very cost- and energy-intensive due to the low degree of automation and are subject to long development cycles. The use of robotic synthesis processes in combination with self-learning machines is intended to overcome these problems in the long term. The development of new types of glass can then not only be accelerated considerably, but also be achieved with much less effort. In this talk, data generation via a robotic high-throughput glass melting system is presented, which should be the experimental basis for the ontology developed within the project GlasDigital. T2 - Materials Science and Engineering Congress (MSE 2022) CY - Darmstadt, Germany DA - 27.09.2022 KW - Oxidglas KW - Robotische Glasschmelzanlage PY - 2022 AN - OPUS4-56489 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - May, Anastasia T1 - Thermomechanochemical Synthesis of Pimelic Acid Cocrystals N2 - Milling temperature is a critical factor in mechanochemistry, affecting the kinetics and outcomes of reactions. In the context of cocrystallization, the influence of milling temperature on the process has been investigated for cocrystal systems pyrazinamide:pimelic acid (PZA:PA) and 4,4'-bipyridine:pimelic acid (BPY:PA). By means of temperature-controlled milling, stabilization of metastable polymorph of PZA:PA was achieved, thereby decelerating the aging process of the polymorph. This was accomplished through controlled heated milling of PZA and PA. Furthermore, we have successfully synthesized all three BPY:PA polymorphs by mechanochemistry involving controlled cooled and heated milling. In previous studies, only the most stable polymorph was obtained by mechanochemistry. T2 - 10th European Crystallography School CY - Ohrid, North Macedonia DA - 23.06.2025 KW - Mechanochemistry KW - Cocrystal PY - 2025 AN - OPUS4-63797 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Moss, Caitlin T1 - Mechanochemistry as a Green Synthetic Route N2 - Mechanochemistry has emerged as a transformative approach in sustainable chemistry, offering a solvent-free and energy-efficient pathway for chemical synthesis. By utilizing mechanical force—typically through ball milling, grinding, or other shear-driven methods, reactions can proceed without the extensive use of harmful solvents, reducing waste and environmental impact. This poster explores the principles, methodologies, and applications of mechanochemistry in developing greener synthetic routes, with a focus on pharmaceutical and materials science applications. Key advantages, including reduced reaction times, enhanced selectivity, and improved atom economy, will be highlighted alongside challenges such as scalability. By presenting mechanochemistry as a frontier technology at the intersection of chemistry, materials science, and environmental stewardship, this work invites dialogue among students and academics about its future in sustainable innovation. T2 - Furture WINS 2024 CY - Berlin, Germany DA - 21.11.2024 KW - Mechanochemistry KW - Green chemistry PY - 2024 AN - OPUS4-62123 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Casali, Lucia T1 - Kinetics of the mechanically induced ibuprofen-nicotinamide co-crystal formation by in-situ X-ray diffraction N2 - Mechanochemistry offers sustainable synthesis for pharmaceuticals, though scaling remains challenging. By combining time-resolved in situ X-ray diffraction with kinetic modeling on the mechanosynthesis of the co-crystal ibuprofen-nicotinamide, we identified the reaction-driving factors. This deeper insight opens the way for a scale-up of mechanochemistry in the pharmaceutical industry. T2 - BESSY User meeting CY - Berlin, Germany DA - 11.12.2024 KW - Mechanochemistry KW - Kinetics KW - In-situ monitoring PY - 2024 AN - OPUS4-62193 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Stolar, Tomislav T1 - Waste to value: upcycling PET bottles into MOFs using mechanochemistry N2 - Single-use plastics are causing plastic pollution, and less than 10% of plastic waste gets recycled globally. Most of it ends up in landfills or gets incinerated in a highly unsustainable manner. Here, I will present a sustainable mechanochemical protocol for the chemical upcycling of waste polyethylene terephthalate (PET) bottles to porous UiO-66 metal-organic framework (MOF). We used in situ and ex situ characterization to gain a deep understanding of the underlying mechanochemical process leading to high crystallinity and -porosity UiO-66. Our results show the potential of mechanochemistry for the sustainable production of high-quality value-added materials such as UiO-66 from waste PET bottles. T2 - 2024 Green Chemistry Gordon Research Conference CY - Barcelona, Spain DA - 31.07.2024 KW - Mechanochemistry KW - Plastic recycling KW - Circular economy PY - 2024 AN - OPUS4-62107 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Duffner, Eric A1 - Mair, Georg W. T1 - Lebensdauerabschätzung von Composite-Druckgefäßen / COD-AGE N2 - Angewendete Messverfahren im Themenfeldprojekt "Lebensdauerabschätzung von Composite-Druckgefäßen" / COD-AGE T2 - Beirat TF Material CY - BAM Berlin, Germany DA - 26.04.2018 KW - Lebensdauerabschätzung KW - Composite-Druckgefäße KW - Degradation PY - 2018 AN - OPUS4-44898 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Epple, Niklas T1 - Monitoring of Concrete with Embedded Ultrasound Sensors, Coda Waves and a Novel Measurement Device N2 - Using embedded ultrasound (US) sensors in civil engineering structures and Coda Wave Interferometry (CWI), DFG research group CoDA aims for developing methods of concrete damage assessment by combination of Micro and macro scale simulations and experiments. BAMs goal within the project is the provision of small and durable measurement equipment on the one hand, and the investigation of damage sensitive parameters and development of an imaging algorithm on the other hand. In this study we focus on the development of the measurement system and the influence of temperature variations on the measurements. T2 - Summer School DFG FOR CoDA CY - Berchtesgaden, Germany DA - 27.09.2020 KW - Ultrasound KW - Coda Wave Interferometry KW - Structural Health Monitoring PY - 2020 AN - OPUS4-51382 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Fabry, Çağtay T1 - Prozessregelung: MSG-Engspaltschweißen (IGF-Nr. 17.923N) N2 - Übersichtposter zu IGF-Vorhaben 17.923N "Sensorgestütztes MSG-Engspaltschweißen von Feinkornstählen mit modifizierter Prozessführung im Dickblechbereich" (DVS-Nr. 03.111) T2 - Fachbereichspräsentation 9.3 CY - Berlin, Germany DA - 01.03.2018 KW - MSG-Engspaltschweißen KW - Adaptives Schweißen KW - Lichtbogensensorik KW - Füllgradregelung PY - 2018 AN - OPUS4-44361 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Fabry, Çağtay T1 - Digitalisierung: iLap – Adaptive Prozesse für die vernetzte Produktion N2 - Übersichtposter zu TP 2.3: "Adaptive Lichtbogenschweißprozesse" des BMBF WKP Verbundprojekts iLap T2 - Fachbereichspräsentation 9.3 CY - Berlin, Germany DA - 01.03.2018 KW - Digitalisierung KW - Schweißdatenmanagement KW - Vernetzte Produktion KW - Prozessregelung KW - Adaptives Schweißen PY - 2018 AN - OPUS4-44359 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schmalz, Alina T1 - Framework Materials for the Electrocatalytic Reduction of Nitrate to Ammonia N2 - The electrocatalytic reduction of nitrate to ammonia offers a sustainable alternative to the energy-intensive Haber-Bosch process while simultaneously addressing the pressing issue of nitrate pollution in water sources. Developing efficient catalysts for this reaction is therefore vital for both environmental remediation and green ammonia production. Framework materials such as metal-organic frameworks (MOFs) or metalated covalent organic frameworks (COFs) present an emerging class of electrocatalytic materials due to their high surface area, tunable porosity, and structural modularity. Their ability to incorporate diverse metal centers and functional groups makes them promising candidates for selective and efficient nitrate reduction. In order to change and improve catalytic properties, different synthesis strategies can be pursued, such as metal alloying, doping or calcination. To fully understand and optimize these materials, advanced characterization techniques are essential to correlate structural features with catalytic performance, alongside in-situ methods for real-time mechanistic insights. T2 - 10th European Crystallography School CY - Ohrid, North Macedonia DA - 23.06.2025 KW - Electrocatalysis KW - Electrochemistry KW - Framework Materials KW - Ammonia Synthesis KW - Nitrate Reduction PY - 2025 AN - OPUS4-63846 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Ruehle, Bastian T1 - Nano- and Advanced Materials Synthesis in a Self-Driving Lab (SDL) N2 - Nano- and advanced materials have been recognized as a key enabling technology of the 21st century, due to their high potential of driving innovations in new clean energy technologies, sustainable manufacturing by substitution of critical raw materials and replacement of hazardous substances, breakthroughs in energy conversion and storage, improvement of the environmental performance of products and processes, and facilitation of circularity. Consequently, improving tools that enhance the development and optimization cycle of nano- and advanced materials is crucial. In this contribution, we present our Self-Driving Lab (SDL) for Nano and Advanced Materials [1], that integrates robotics for batched autonomous synthesis – from molecular precursors to fully purified nanomaterials – with automated characterization and data analysis, for a complete and reliable nanomaterial synthesis workflow. 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. The system also exhibits high modularity and adaptability in terms of reaction scales and incorporates in-line characterization measurement of hydrodynamic diameter, zeta potential, and optical properties (absorbance, fluorescence) of the nanomaterials. We discuss the excellent reproducibility of the various materials synthesized on the platform in terms of particle size and size distribution, and the adaptability and modularity that allows access to a diverse set of nanomaterial classes. These features underscore the SDL’s potential as a transformative tool for advancing and accelerating the development of nano- and advanced materials, offering solutions for a sustainable and environmentally responsible future. T2 - Accelerate 2025 CY - Toronto, Canada DA - 11.08.2025 KW - Nanomaterials KW - Advanced Materials KW - Automation KW - SDL KW - MAP PY - 2025 AN - OPUS4-63935 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Alić Stolar, Jasna T1 - Harnessing mechanochemistry to combat PFAS contamination N2 - For over 70 years, the uncontrolled production, use, and disposal of per- and polyfluoroalkyl substances (PFAS) have led to widespread global contamination, necessitating the rapid development of innovative and efficient remediation technologies. State-of-the-art strategies rely on energy-intensive incineration, which releases greenhouse gases and smaller, volatile PFAS derivatives. Here, we present a fast, simple, and sustainable method for the complete degradation of PFAS leveraging mechanochemistry to break down the persistent carbon-fluorine bonds. Our findings indicate that liquid-assisted grinding conditions accelerate the degradation of perfluorooctanoic acid compared to neat grinding conditions, resulting in a significant reduction in energy consumption. Moreover, the fluoride released during the process binds to inorganic additives, allowing fluorine recovery as crystalline salts and preventing the formation of secondary toxic waste. The method has strong potential for scaling up and offers a green and viable solution for real-world application in PFAS decontamination. T2 - The International Symposium on Mechanochemistry (Mech’cheM 2025) CY - Montpellier, France DA - 04.06.2025 KW - Mechanochemistry KW - PFAS PY - 2025 AN - OPUS4-63956 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Alić Stolar, Jasna T1 - Harnessing mechanochemistry to tackle PFAS pollution N2 - We are currently facing one of the most serious environmental crises in human history – the widespread pollution caused by PFAS. PFAS stands for per- and polyfluoroalkyl substances, which are toxic, persistent, highly mobile, and bioaccumulative compounds, often referred to as 'forever chemicals'. For over 70 years, they have been used to make products resistant to water, heat, and stains, but the cost of damaging ecosystems and harming human health was revealed far too late. As of 2023, there were more than 23,000 confirmed PFAS contamination sites in Europe alone, with at least an equal number of presumptive contamination sites due to historical and current industrial activities.1 Public concern has pushed regulatory bodies to restrict the production of the most common PFAS, but with over 10,000 PFAS compounds and existing contamination, the problem remains largely unresolved. State-of-the-art remediation strategies rely on energy-intensive incineration, which releases greenhouse gases and smaller, volatile PFAS derivatives.2 Here, we present a fast, simple, and sustainable method for the complete degradation of PFAS, leveraging mechanochemistry3 to break down the persistent carbon-fluorine bonds. Our findings indicate that liquid-assisted grinding conditions accelerate the degradation of perfluorooctanoic acid compared to neat grinding conditions, resulting in a significant reduction in energy consumption. Moreover, the fluoride released during the process binds to inorganic additives, allowing fluorine recovery as crystalline salts and preventing the formation of secondary toxic waste. The method has strong potential for scaling up and offers a green and viable solution for real-world application in PFAS decontamination. T2 - Tag der Chemie CY - Berlin, Germany DA - 03.07.2025 KW - Mechanochemistry KW - Forever chemicals KW - Sustainability PY - 2025 AN - OPUS4-63972 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schmidt, Jonathan T1 - High-resolution in-situ image analysis in laser powder bed fusion N2 - Visual images captured - in-situ - in laser powder bed fusion (PBF-LB/M) provide valuable insights into process dynamics. This poster presents methods for analyzing high-resolution images with a spatial resolution of 17 µm/pixel and a size of 9344 × 7000 pixels. In the context of identifying microstructural anomalies, the relationship between the contrast values derived from the grey-level co-occurrence matrix (GLCM) of post-exposure images and ex situ measurements of surface roughness, porosity, and melt pool depth is illustrated. Furthermore, a workflow to detect process anomalies in post recoating images using an edge device is presented. T2 - BAM Advisory Council Meeting CY - Berlin, Germany DA - 25.06.2025 KW - Additive manufacturing KW - High resolution camera KW - Image processing KW - In situ monitoring KW - Powder bed fusion PY - 2025 AN - OPUS4-63990 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - George, Janine T1 - Automated bonding analysis based on crystal orbital Hamilton populations N2 - We created a workflow that fully automates bonding analysis using Crystal Orbital Hamilton Populations, which are bond-weighted densities of states. This enables understanding of crystalline material properties based on chemical bonding information. To facilitate data analysis and machine-learning research, our tools include automatic plots, automated text output, and output in machine-readable format. T2 - Sommersymposium des Fördervereins Chemieolympiade CY - Online meeting DA - 25.06.2022 KW - Bonding Analysis KW - Automation KW - DFT PY - 2022 AN - OPUS4-55409 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Ertural, Christina T1 - Vibe Check via Machine Learning: Testing the Prototype N2 - Vibrational properties play a key role in determining the stability and thermal conductivity behaviour of materials. The quasi- harmonic approximation gives insight into the phononic properties of a compound, but in the established way, i.e. density functional theory based methods, it takes many calculation steps and consumes a lot of resources to arrive at the desired results. Machine learning (ML) trained interatomic potentials (e.g. Gaussian approximation potential, GAP) pose an alternative to the traditional computation way of phonons. We develop a Python code based workflow which combines automation tools like atomate2 with ML to ease providing interactomic potentials for (quantum chemical) computations and databases. T2 - #RSCPoster Twitter conference 2023 CY - Online meeting DA - 28.02.2023 KW - Interatomic potentials KW - Machine learning KW - Phonons KW - Workflow PY - 2023 UR - https://twitter.com/cer5814012/status/1630547004462858240 AN - OPUS4-57059 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Naik, Aakash T1 - New descriptors for materials properties based on bonding indicators N2 - Includes a summary of the Ph.D. project that deals with generating a database populated with materials bonding properties and how we intend to gain deeper insights into material properties through this research. T2 - SALSA 2022 CY - Berlin, Germany DA - 15.09.2022 KW - Bonding analysis KW - Automation KW - Materials Informatics KW - Computational Chemistry PY - 2022 AN - OPUS4-56142 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - George, Janine T1 - A Quantum-Chemical Bonding Database for Solid-State Materials N2 - A deep insight into the chemistry and nature of individual chemical bonds is essential for understanding materials. Bonding analysis is expected to provide important features for large-scale data analysis and machine learning of material properties. Such information on chemical bonds can be calculated using the LOBSTER (www.cohp.de) software package, which post-processes data from modern density functional theory computations by projecting plane wave-based wave functions onto a local atomic orbital basis. We have performed bonding analysis on 1520 compounds (insulators and semiconductors) using a fully automated workflow combining the VASP and LOBSTER software packages. We then automatically evaluated the data with LobsterPy (https://github.com/jageo/lobsterpy) and provide results as a database. The projected densities of states and bonding indicators are benchmarked on VASP projections and available heuristics, respectively. Lastly, we illustrate the predictive power of bonding descriptors by constructing a machine-learning model for phononic properties, which shows an increase in prediction accuracies by 27 % (mean absolute errors) compared to a benchmark model differing only by not relying on any quantum-chemical bonding features. T2 - Sommersymposium des Fördervereins Chemieolympiade CY - Online meeting DA - 15.04.2023 KW - Automation KW - Chemical Bonds KW - DFT KW - Quantum Chemistry PY - 2023 AN - OPUS4-57310 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Naik, Aakash T1 - Building quantum chemical orbital based bonding descriptor database N2 - Motivation, methodology and and results of our quantum chemical bonding descriptors database presented in form of a Poster T2 - RSC Twitter Conference 2023 CY - Online meeting DA - 28.02.2023 KW - Bonding analysis KW - Automation KW - Materials Informatics KW - Computational Chemistry KW - Database PY - 2023 UR - https://twitter.com/NaikAak/status/1630400167080869893 UR - https://twitter.com/NaikAak/status/1630540436434558977 AN - OPUS4-57101 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Naik, Aakash A1 - Ertural, Christina A1 - Dhamrait, Nidal A1 - Benner, Philipp A1 - George, Janine T1 - A Quantum-Chemical Bonding Database for Solid-State Materials N2 - Understanding the chemistry and nature of individual chemical bonds is essential for materials design. Bonding analysis via the LOBSTER software package has provided valuable insights into the properties of materials for thermoelectric and catalysis applications. Thus, the data generated from bonding analysis becomes an invaluable asset that could be utilized as features in large-scale data analysis and machine learning of material properties. However, no systematic studies exist that conducted high-throughput materials simulations to curate and validate bonding data obtained from LOBSTER. Here we present an approach to constructing such a large database consisting of quantum-chemical bonding information. T2 - 16th International conference on materials chemistry (MC16) CY - Dublin, Ireland DA - 03.07.2023 KW - Bonding analysis KW - Automation KW - Materials Informatics KW - Computational Chemistry KW - Database PY - 2023 AN - OPUS4-57889 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bustamante, Joana A1 - Naik, Aakash A1 - Ueltzen, Katharina A1 - Ertural, Christina A1 - George, Janine T1 - Thermodynamic and Thermoelectric Properties of the Canfieldite, (Ag8SnS6 ), in the Quasi-Harmonic Approximation N2 - Argyrodite-type materials have lately sparked a lot of research interest due to their thermoelectric properties. One promising candidate is canfieldite (Ag8SnS6), which has a Pna21 orthorhombic crystal structure at room temperature (RT). Recently, Slade group found a new low-temperature (LT) phase transition of canfieldite at 120K. Therefore, we investigate structural, vibrational and thermodynamic properties of Ag8SnS6 at room- and low-temperature employing density-functional theory (DFT) and lattice dynamics computations. Thermal properties calculations were based on the quasi-harmonic approximation (QHA) as implemented in phonopy. We achieve good agreement with experiments. Lattice parameters were overestimated by 2%, and thermal properties such as the constant-pressure heat capacity Cp are very close to experimental measurements. Our simulations also reveal a possible new phase transition at around 312 K. Furthermore, we compared RT and LT Ag8SnS6 Grüneisen parameters with some argyrodites analogues, Ag8TS6 (T = Si, Ge, Ti and Sn), finding a relationship between the anharmonicity and low thermal conductivity. T2 - TDEP Summer School 2023 (TDEP2023: Finite-temperature and anharmonic response properties of solids in theory and practice) CY - Linköping, Sweden DA - 20.08.2023 KW - Thermoelectric materials KW - DFT KW - QHA KW - Grüneisen parameter PY - 2023 AN - OPUS4-58147 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Naik, Aakash T1 - Material property predictions by incorporating quantum chemical bonding information N2 - Interactions between constituent atoms in crystalline materials have been shown to influence the properties of materials, such as elasticity, ionic and thermal conductivity, etc.[1–3] These interactions between constituent atoms, often quantified as bond strengths, can be extracted from crystalline materials using density-based[4], energy-based[5], and orbital-based methods. LOBSTER[6] is a software that relies on the orbital-based method to extract such bonding information by projecting the plane wave-based wave functions of modern density functional theory computations (DFT) onto a local atomic orbital basis. To garner a better understanding of how this bonding information relates to material properties on a larger scale, machine learning seems an obvious choice. However, for such data-driven studies, large quantities of data that are systematically generated, validated, and post-processed (feature engineering) in a form suitable for input in state-of-the-art ML models are often needed.[7] Here, we first present a workflow implemented in atomate2[8] that can generate such bonding-related data using the LOBSTER program with minimal user input and a post-processing tool, LobsterPy[9], which can summarize and engineer features that could be directly used as input for ML studies. Lastly, we demonstrate the utility of these newly generated features by building a simple machine-learned model to predict harmonic phonon properties using the bonding dataset[10] generated by us for 1500 materials. We find a clear correlation between the bonding information and the phonon property. T2 - STC 2024 CY - Braunschweig, Germany DA - 02.09.2024 KW - Bonding analysis KW - Machine learning KW - Feature engineering PY - 2024 AN - OPUS4-61130 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Ertural, Christina T1 - Phonon-accurate machine-learning potentials from automated workflows N2 - Data-driven materials design aims to predict and optimize material properties, such as stability and thermal conductivity, which are influenced by vibrational behavior. Approaches like DFT are computationally demanding and have limitations for phonon calculations. Machine learning-driven interatomic potentials (MLIP), like the Gaussian approximation potential (GAP), offer a more efficient alternative.1–8 We developed a Python workflow to automate MLIP generation using the Materials Project database.9 DFT computations, MLIP fitting and benchmark steps are automated.10,11 This approach accelerates phonon calculations and supports testing different data generation strategies and hyperparameters, and further validation12 is planned. Our goal is to provide open-source code and share these potentials. T2 - Faraday Discussions: Data-driven discovery in the chemical sciences CY - Oxford, UK DA - 10.09.2024 KW - Interatomic potentials KW - Machine learning KW - Phonons KW - Thermoelectrics PY - 2024 AN - OPUS4-61061 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Naik, Aakash T1 - Enhancing material property predictions using quantum chemical bonding descriptors N2 - The properties of crystalline materials, such as elasticity, ionic conductivity, and thermal conductivity, are influenced by interactions between their constituent atoms.[1–3] These interactions, which are often quantified in terms of bond strength, can be extracted from crystalline materials using density-based[4], energy-based[5] and orbital-based methods. LOBSTER[6] is a software that relies on the orbital-based method to extract such bonding information by projecting the plane wave-based wave functions of modern density functional theory computations (DFT) onto a local atomic orbital basis. To garner a better understanding of how this bonding information relates to material properties on a larger scale, machine learning seems an obvious choice. However, for such data-driven studies, large quantities of data need to be systematically generated, validated, and post-processed (e.g., by feature engineering), as they can only then be used as input for state-of-the-art ML models. We have, therefore, previously developed workflows for high-throughput bonding analysis[7]. In this work, we use the results[8] from high-throughput LOBSTER calculations using our workflows to generate bonding-based features. To extract such features from the LOBSTER computations, we use our package LobsterPy.[9] The importance of these features is then tested by employing them in several state-of-the-art ML algorithms and architectures to predict the mechanical and vibrational properties of crystalline materials. We show that including these bonding-based features alongside typical composition and structure-based features helps enhance the model’s predictive accuracy. T2 - 18th German Conference on Cheminformatics CY - Bad Soden am Taunus, Germany DA - 03.11.2024 KW - Bonding analysis KW - Machine learning KW - Materials Descriptors PY - 2024 AN - OPUS4-62217 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Ueltzen, Katharina T1 - Unveiling the potential of the Kanamori-Goodenough-Anderson rules for magnetic property prediction N2 - Recently, machine learning of magnetic properties of transition metal compounds has attracted large interest due to environmental and availability issues of rare-earth-based functional magnetic materials. Surprisingly, bond-angle-derived features were not found to be relevant for magnetic structure prediction in previous studies using DFT-computed labels. This contrasts with a well-known magnetism heuristic, the Kanamori-Goodenough-Anderson (KGA) rules of superexchange. We review magnetic interaction trends within the MAGNDATA database of experimentally determined magnetic structures. Observed trends follow the KGA rules „of thumb“ and exceptions can be rationalized. We introduce a new, informative label for predicting magnetic structures that can be extended to magnetic sites and structures of arbitrary complexity. Bond-angle-derived features are found to be highly relevant for magnetic structure prediction. T2 - Faraday Discussion: Data-driven discovery in the chemical sciences CY - Oxford, UK DA - 10.09.2024 KW - Magnetism KW - High-throughput analysis KW - Machine learning KW - Transition metal compounds PY - 2024 AN - OPUS4-62250 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Ueltzen, Katharina T1 - Revisiting the Kanamori-Goodenough-Anderson rules for magnetic property prediction N2 - Recently, machine learning of magnetic properties of transition metal compounds has attracted large interest due to environmental and availability issues of rare-earth-based functional magnetic materials. Surprisingly, bond-angle-derived features were not found to be relevant for magnetic structure prediction in previous studies using DFT-computed labels. This contrasts with a well-known magnetism heuristic, the Kanamori-Goodenough-Anderson (KGA) rules of superexchange. We review magnetic interaction trends within the MAGNDATA database of experimentally determined magnetic structures. Observed trends follow the KGA rules „of thumb“ and exceptions can be rationalized. We introduce a new, informative label for predicting magnetic structures that can be extended to magnetic sites and structures of arbitrary complexity. Bond-angle-derived features are found to be highly relevant for magnetic structure prediction. T2 - 60th Symposium on Theoretical Chemistry (STC 2024) CY - Braunschweig, Germany DA - 02.09.2024 KW - Magnetism KW - High-throughput analysis KW - Machine learning KW - Transition metal compounds PY - 2024 AN - OPUS4-62249 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Benner, Philipp A1 - Grandel, Jonas T1 - A shortcut towards phonon predictions N2 - Phonon calculations with ab-initio methods are computationally expensive. The use of universal machine learning models reduces the cost, but raises concerns about prediction quality. Fine-tuning with only a few structures, improves predictions of phonons, thermal properties and especially diffusive thermal conductivity, while reducing computational cost by a factor of 10 in average compared to DFT methods. T2 - DPG Frühjahrstagung CY - Regensburg, Germany DA - 16.03.2025 KW - Machine Learning KW - MACE KW - Phonons PY - 2025 AN - OPUS4-62770 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Weltschev, Margit T1 - Comparison of the environmental stress cracking behaviour of polyethylene and polyethylene terephthalate as materials for dangerous goods packagings N2 - The chemical industry has expressed great interest in using polyethylene terephthalate (PET) as material for packagings for the transport of dangerous goods. Due to the high strength and stiffness of PET, the wall thickness and weight of packagings can be reduced. This is a relevant cost factor. PET is a semi-crystalline thermoplast which is produced by polycondensation of terephthalic acid and ethylene glycol. According to the European dangerous goods regulations RID and ADR, samples of PET design types of packagings for dangerous goods must be pre-stored with the original filling good for six months at 23°C, before the design type tests can be carried out. For packagings made of polyethylene (PE) tests to prove the stress cracking resistance by using laboratory methods are possible to reduce time and costs. Therefore, standard liquids, simulating the different types of damaging effects on PE are defined in RID and ADR. However, there is no information and research available about the damaging mechanisms on PET in comparison to PE, especially regarding to stress cracking resistance and test methods. The aim of this work is to compare the stress cracking resistance of PE and PET with the Full Notch Creep Test (FNCT), which was developed by chemical industry and is described in the standards EN ISO 16101 and EN 15507. It was investigated whether testing specimens made of PE and PET with a full coplanar notch around the middle of the specimens show weakening after the impact of a tensile force in a wetting solution (Lutensol® FSA 10) at 50°C in a test device on the basis of the FNCT. The test results confirmed the suitability of the method for eight PE grades. Unfortunately, this method couldn’t be used for PET because the specimens broke during notching. In addition the molding of the sheets and the following temper process for twelve hours are very time-consuming, and the specimens broke during notching due to the high brittleness of PET. Another possibility to provide evidence of stress cracking resistance of PE packagings is laid down in BAM’s Dangerous Goods Rule BAM-GGR 015. This test was carried out with PE and PET bottles to compare both materials. Therefore 1l test bottles were filled with a 5% wetting solution and mounted with a clamping tool for 28 days at 40°C. Tensile test specimens were cut out afterwards from the middle of the bottles in the deformed areas. Tensile strength and breaking elongation of PE specimens were determined in comparison to the PET specimens. The tensile properties of the PET specimens couldn’t be determined due to the strength and the stiffness of the material. In conclusion the only way to provide information about the stress cracking resistance of PET was to perform stacking tests. 1l bottles made of PE and PET were filled with a 5% wetting solution and stored with a stacking load for 28 days at 40°C according to EN ISO 16495. Design types of PE and PET both passed the stacking tests. T2 - EUROCORR 2016 CY - Montpellier, France DA - 11.09.2016 KW - polyethylene terephthalate KW - stress cracking resistance KW - test methods KW - dangerous goods packagings PY - 2016 AN - OPUS4-37448 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Weltschev, Margit T1 - Suitable test method for the determination of the environmental stress cracking behaviour of polyethylene terephthalate as material for dangerous goods packagings N2 - The chemical industry has expressed great interest in using polyethylene terephthalate (PET) as material for packagings for the transport of dangerous goods. Due to the high strength and stiffness of PET, the wall thickness and weight of packagings can be reduced. The aim of this work was to find a laboratory test method for the determination of the stress cracking resistance of PET. One test method is the Full Notch Creep Test (FNCT), which was developed for polyethylene (PE) and is described in the standards EN ISO 13274 and EN 15507. It was investigated whether testing specimens made of PET with a full coplanar notch around the middle of the specimens show weakening after the impact of a tensile force in a wetting solution at 50°C. Unfortunately, this method couldn’t be used for PET because the specimens broke during notching due to the high brittleness of PET. The molding of the sheets and the following temper process for twelve hours are very time-consuming, Another possibility is laid down in BAM’s Dangerous Goods Rule BAM-GGR 015. This test was carried out with 1l PET bottles, which were filled with a 5% wetting solution and mounted with a clamping tool for 28 days at 40°C. Tensile test specimens were cut out afterwards from the middle of the bottles in the deformed areas. The tensile properties of the PET specimens couldn’t be determined due to the hardness of the material. In conclusion, the only way to provide information about the stress cracking resistance of PET was to perform stacking tests with PET design types of packagings. 1l bottles made of PET were filled with a 5% wetting solution and stored with a stacking load for 28 days at 40°C according to EN ISO 16495. The test bottles of PET passed the stacking tests. T2 - Fifth International Symposium Frontiers in Polymer Science CY - Seville, Spain DA - 17.05.2017 KW - Polyethylene terephthalate KW - Stress cracking resistance KW - Laboratory method KW - Dangerous goods packaging PY - 2017 AN - OPUS4-40438 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Neumann, Patrick P. T1 - Outdoor Gas Plume Reconstructions: A Field Study with Aerial Tomography N2 - This paper outlines significant advancements in our previously developed aerial gas tomography system, now optimized to reconstruct 2D tomographic slices of gas plumes with enhanced precision in outdoor environments. The core of our system is an aerial robot equipped with a custom-built 3-axis aerial gimbal, a Tunable Diode Laser Absorption Spectroscopy (TDLAS) sensor for CH4 measurements, a laser rangefinder, and a wide-angle camera, combined with a state-of-the-art gas tomography algorithm. In real-world experiments, we sent the aerial robot along gate-shaped flight patterns over a semi-controlled environment with a static-like gas plume, providing a welldefined ground truth for system evaluation. The reconstructed cross-sectional 2D images closely matched the known ground truth concentration, confirming the system’s high accuracy and reliability. The demonstrated system’s capabilities open doors for potential applications in environmental monitoring and industrial safety, though further testing is planned to ascertain the system’s operational boundaries fully. T2 - 20th International Symposium on Olfaction and Electronic Nose CY - Grapevine, Texas, USA DA - 12.05.2024 KW - Aerial Robot KW - TDLAS KW - Gas Tomography KW - Plume PY - 2024 AN - OPUS4-60108 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Lehmusto, Juho T1 - Initial oxidation of the refractory high-entropy superalloy AlMo0.5NbTa0.5TiZr N2 - In contrast to traditional alloys, which are typically based on a single dominant element, high-entropy alloys (HEAs) consist of five or more principal elements in roughly equal proportions. These complex alloys often exhibit superior characteristics compared to conventional alloys, including enhanced strength and hardness, exceptional wear resistance, high structural stability, and strong resistance to oxidation. Despite these promising characteristics, the vast compositional space of HEAs means that only a limited number have been thoroughly investigated for their mechanical and chemical behavior. One notable example is the refractory high-entropy superalloy AlMo0.5NbTa0.5TiZr, which represents a newly emerging class of materials. This alloy features a nanoscale microstructure composed of B2 and bcc phases, resulting in compressive strength at elevated temperatures that surpasses that of conventional Ni-based superalloys. Such performance offers potential benefits for improving turbine efficiency in aerospace and energy generation applications. However, the alloy’s microstructure is known to be sensitive to annealing. Specifically, its mechanical properties deteriorate when intragranular hexagonal Al-Zr-based intermetallic compounds form, likely due to issues with phase stability. On the other hand, the inclusion of Al has been shown to enhance oxidation resistance. Nevertheless, HEAs are also known to develop pronounced internal aging zones caused by diffusion during oxidation processes. These findings indicate a need for further investigation into the thermodynamic stability of this alloy. In addition, its oxidation behavior—both at the surface and within the material—remains incompletely understood. This ongoing research explores the oxidation behavior of the AlMo0.5NbTa0.5TiZr alloy at temperatures ranging from 800 °C to 1000 °C. The influence of water vapor on the oxidation process is also examined. Ultimately, the goal is to integrate insights into the alloy’s structural, mechanical, and chemical characteristics at high temperatures. T2 - Gordon Research Conference - High Temperature Corrosion CY - New London, United States DA - 16.07.2023 KW - High-Entropy superalloy KW - Phase stability KW - Microstructural evolution KW - Oxidation behavior KW - High-Temperature Performance PY - 2023 AN - OPUS4-63851 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Erdmann, Maren T1 - Mechanical characterization of high-density polyethylene in contact with diesel and biodiesel fuels N2 - Renewable resources become more and more relevant to maintain energy demands for an increasing global population. Biosynthetic fuels like biodiesel might replace conventional petrochemical fuels, such as diesel. However, more research is needed to characterize the interaction between the different fuels and polymeric materials widely used in the fuel infrastructure as well as for automotive parts. Especially changes in the structural properties and mechanical behavior of the polyethylene (PE-HD) have to be addressed. The presented work comprises the direct interaction of high density polyethylene (PE-HD) with diesel and biodiesel, resulting in swelling and plasticization. Also long-term degradation phenomena will be discussed. The chosen PE-HD types are typical thermoplastic resins for container and storage tank applications. The impact of diesel and biodiesel in PE-HD is investigated by changes in the mechanical properties with emphasis on the Charpy impact strength. Furthermore, structural and dynamic influences on the polymeric material induced by diesel and biodiesel are proven in Dynamic Mechanical Analysis (DMA). Both methods, Charpy impact strength and DMA, reveal softening effects due to the migration of diesel and biodiesel into the amorphous regions of PE-HD. Since biodiesel is more prone to oxidative degradation compared to diesel, the fuel/air/polymer-interaction is studied for partly immersed tensile test specimens. Main focus of the evaluation is the co-oxidation. Here, the accelerated deterioration of PE caused by the sorption of the facile oxidation of biodiesel into the solid polymer might be a major degradation mechanism in this context. T2 - POLYDAYS 2016 CY - Potsdam, Germany DA - 28.09.2016 KW - PE-HD KW - Diesel KW - Biodiesel KW - Oxidation PY - 2016 AN - OPUS4-37677 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Roveda, Ilaria T1 - Effect of heat treatment on the microstructure, residual stress state and fatigue properties of PBF-LB/M AlSi10Mg N2 - Al-Si alloys produced by Laser Powder Bed Fusion (PBF-LB/M) techniques allow the fabrication of lightweight free-shape components. Due to the extremely heterogeneous cooling and heating, PBF-LB/M induces high magnitude residual stress (RS) and a fine Si microstructure. As the RS can be deleterious to the fatigue resistance of engineering components, great efforts are focused on understanding their evolution before and after post-process heat treatments (HT). T2 - Alloys for Additive Manufacturing Symposium 2022 (AAMS22) CY - Munich, Germany DA - 12.09.2022 KW - Neutron diffraction KW - X-ray diffraction KW - Crack propagation PY - 2022 AN - OPUS4-55871 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Roveda, Ilaria T1 - Investigation of residual stresses and microstructure effects on the fatigue behaviour of a L-PBF AlSi10Mg alloy N2 - Al-Si alloys produced by Laser Powder Bed Fusion (L-PBF) techniques allow the fabrication of lightweight free-shape components. Due to the high cooling rates occurring during the building process, L-PBF AlSi10Mg alloys exhibit an ultra-fine microstructure that leads to superior mechanical properties in the as-built condition compared to conventional cast Al-Si materials. Nevertheless, L-PBF processing induces high thermal gradients, leading to deleterious residual stress. In order to relax detrimental residual stress and to increase the ductility, post-processing stress relief treatments are performed. The objective of the contribution is to investigate, under different heat treatment condition, the evolution of microstructure and residual stresses in view of optimizing the fatigue performance of the alloy. To this purpose various heat treatments in a range of temperatures between 265°C and 300°C for a duration between 15 minutes and 2 hours are performed. T2 - Fatigue Design 2021 CY - Senlis, France DA - 17.11.2021 KW - AlSi10Mg KW - Additive manufacturing KW - L-PBF KW - Residual stress KW - Heat treatment PY - 2021 AN - OPUS4-53794 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Stolar, Tomislav T1 - Mechanochemical Conversion Of Polyethylene Terephthalate Into Valuable Metal-organic Frameworks N2 - Single-use plastics are causing plastic pollution, and less than 10% of plastic waste is recycled globally. Here, we present a sustainable mechanochemical protocol for converting post-consumer polyethylene terephthalate (PET) textile and bottles into the porous metal-organic framework (MOF) UiO-66. We used time-resolved in situ synchrotron powder X-ray diffraction and Raman spectroscopy to monitor the depolymerization of PET during ball milling with sodium and potassium hydroxide and water as a liquid additive. For synthesizing UiO-66, we focused on the better performing sodium hydroxide and optimized two distinct synthetic routes to produce high-quality UiO-66. Our results demonstrate the potential of mechanochemistry to enable more circular MOF synthesis using post-consumer PET waste. T2 - International Conference on Sustainable Chemistry for Net Zero CY - St. Andrews, United Kingdom DA - 10.06.2025 KW - Mechanochemistry KW - Plastic recycling KW - Circular economy PY - 2025 AN - OPUS4-63944 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schilling, Markus T1 - Failure of PE-HD induced by liquid media (ESC) N2 - As the well-known damage mechanisms slow crack growth (SCG) and environmental stress cracking (ESC) are the major causes for possible failure of polyolefin-based materials, especially for PE-HD, they are highly relevant and need to be considered thoroughly. Furthermore, due to slight but perceptible differences in damaging effect, a differentiation between SCG and ESC is expedient. SCG appears in “inert” or “neutral” media without a decisive influence of the surrounding medium whereas ESC occurs in “active” media, which influence the failure behavior and time to failure crucially. To characterize the inherent resistance of the material against those damage mechanisms, the well-established Full-Notch Creep Test (FNCT) is used. In this study, the FNCT – usually applied according to ISO 16770 [3] using a few universal model liquid media and mainly for pipe materials – is extended by investigations with appropriate parameters of selected relevant PE-HD container materials also in real media, such as the topical fuels diesel and biodiesel. The investigations were performed using a novel FNCT-device with 12 individual sub-stations, each equipped with individual electronic stress and temperature control and continuous online monitoring of the specimen elongation. Especially, mechanical stress and temperature were varied systematically during FNCT and time to failure values, time-dependent elongation data as well as detailed fracture surface analysis by laser scanning microscopy (LSM) were combined for the first time (Fig. 1). Particularly, the fracture surface analysis provides a sound basis to characterize failure behavior, mainly regarding the balance between brittle crack propagation and ductile deformation. Therefore, fracture surface analysis is an essential tool for a decent assessment of SCG and ESC by FNCT measurements. T2 - 17th International Conference on Deformation, Yield and Fracture of Polymers (DYFP) CY - Kerkrade, The Netherlands DA - 25.03.2018 KW - Environmental stress cracking (ESC) KW - PE-HD KW - Full Notch Creep Test (FNCT) KW - Imaging techniques KW - Brittle / ductile fracture behavior KW - Crack propagation analysis PY - 2018 AN - OPUS4-44617 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Gugin, Nikita T1 - Optimizing the Green Synthesis of ZIF-8 by Reactive Extrusion Using In Situ Raman Spectroscopy N2 - ZIF-8 is a prominent member of the zeolitic imidazolate frameworks (ZIFs) subfamily of MOFs which possesses high thermal, chemical, and mechanical stabilities. Different routes have been explored to achieve the large-scale production of ZIF-8. However, these synthetic procedures are often inconsistent with the principles of sustainable chemical manufacturing. Aimed at developing scalable and greener production of ZIF-8, we adapted our previously reported in-batch „mix and wait“ synthesis[2] to continuous extrusion. To optimize the process, in-situ Raman spectroscopy was applied. Finally, we developed a simple and comprehensive approach to evaluating the environmental friendliness and scalability of MOF syntheses in view of their large-scale production. The synthesis of ZIF-8 was performed using a twin-screw extruder ZE 12 HMI equipped with an automatic volumetric feeder ZD 12B (Three-Tec GmbH, Switzerland) and peristaltic pump BT-L (Lead Fluid, China). The process was monitored in six different zones using a Raman RXN1TM analyzer (Kaiser Optical Systems, France) with a non-contact probe head. PMMA screw-in parts, which are transparent to Raman laser radiation, were specially manufactured to provide the laser focus within the barrel. PXRD, TGA, N2 adsorption measurements, and SEM were used as complementary techniques to characterize the extrudates. The batch ‘mix and wait’ synthesis of ZIF-8, consisting of bringing solid basic zinc carbonate and 2-methylimidazole in contact in a closed vial, was successfully adapted to reactive extrusion. The crystalline ZIF-8 continuously forms in the extruder under the mixing of solid reagents in the presence of a catalytic amounts of H2O or EtOH. The temperature, type of liquid, feeding rate, and excess of linker were optimized using in situ Raman spectroscopy. Pure and highly crystalline ZIF-8 was isolated at 40 °C by adding a catalytic amount of EtOH and a linker excess of 25%. The resulting material has excellent porosity with the BET surface area slightly exceeding that of the reference Basolite® Z1200 (1816 vs. 1734 m2 g–1). The reaction could yield ~ 3 kg d–1 assuming a continuous operation, with a space-time yield of ca. 67,000 kg m–3 d–1. The present method was compared to the published pathways based on Green Chemistry principles and proved to have the highest potential for large-scale production of ZIF-8. T2 - 5th European Conference on Metal Organic Frameworks and Porous Polymers (EuroMOF2023) CY - Granada, Spain DA - 24.09.2023 KW - In situ Raman KW - Reactive extrusion KW - Green chemistry KW - Mechanochemistry KW - MOFs KW - Large-scale synthesis PY - 2023 AN - OPUS4-58950 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Gugin, Nikita A1 - Schwab, Alexander T1 - Reactive extrusion of a model BSA@ZIF-8 biocomposite: a scalable, continuous and sustainable approach N2 - Metal-organic framework-based biocomposites (MOF-biocomposites) are promising materials for biosensing, biocatalysis, and delivery of biopharmaceuticals. One of the most studied MOFs for bioapplications is ZIF-8 (zeolitic imidazolate framework 8) due to its high surface area, high thermal and chemical stability, and low cytotoxicity. The conventional synthesis of ZIF-8-biocomposites called biomimetic mineralization includes mixing selected biomolecules 2-methylimidazole, and soluble Zn2+ source in water. Despite the high efficiency of the method, it does not allow for large-scale production and is restricted to hydrophilic biomolecules. Aimed at developing a scalable and versatile approach, we adapted our recently-reported ZIF-8 reactive extrusion for biocomposite production. We selected bovine serum albumin (BSA) as an inexpensive model biomacromolecule for the preparation of biocomposites. The synthesis of BSA@ZIF-8 was performed using a twin-screw extruder ZE 12 HMI (Three-Tec Gmbh) at a mild temperature of 40 °C. Automatic volumetric feeder ZD 12B (Three-Tec GmbH) was used to supply the reagent mixture consisting of 2-methylimidazole, zinc source, and BSA. To initiate the reaction, a catalytic amount of EtOH was added using a peristaltic pump BT-L (Lead Fluid, China). Powder X-Ray diffraction (PXRD), thermogravimetric analysis (TGA), FTIR, and N2 adsorption were used to characterize the extrudates. Highly crystalline and pure BSA@ZIF-8 with different BSA loadings was isolated after washing the extrudate with EtOH and sodium dodecyl sulfate. The EtOH feeding rate was optimized by following the protein encapsulation efficiency at a BSA mass fraction of 10%. A continuous extruder operation under optimized conditions showed good reproducibility and capability of producing biocomposites on the kilograms scale. These results provide highly valuable information for cheap and large-scale production of ZIF-8-based biocomposites. Due to the lack of restrictions on molecule size and solubility, our proof-of-concept study may significantly expand the selection of biomolecules for immobilization in ZIF-8, making the method applicable to various functional applications T2 - Tag der Chemie 2023 CY - Berlin, Germany DA - 05.07.2023 KW - Biocomposite KW - MOFs KW - Reactive extrusion KW - Zeolitic imidazolate framework PY - 2023 AN - OPUS4-58949 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Gugin, Nikita T1 - Mixing Reactions Enable Green Synthesis of ZIF-8 at Large Scale: Batch and Continuous Modes N2 - We report the scale-up of a batch solid synthesis of zeolitic imidazolate framework-8 (ZIF-8) for reactive extrusion. The crystalline product forms in the extruder directly under the mixture of solid 2-methylimidazole and basic zinc carbonate in the presence of a catalytic amount of liquid. The process parameters such as temperature, liquid type, feeding rate, and linker excess were optimized using the setup specifically designed for in situ Raman spectroscopy. Highly crystalline ZIF-8 with a Brunauer–Emmett–Teller (BET) surface area of 1816 m2 g–1 was quantitatively prepared at mild temperature using a catalytic amount of ethanol and a small excess of the linker. Finally, we developed a simple and comprehensive approach to evaluating the environmental friendliness and scalability of metal–organic framework (MOF) syntheses in view of their large-scale production. T2 - 2023 #RSCPoster Twitter Conference CY - Online meeting DA - 28.02.2023 KW - MOFs KW - Green chemistry KW - Reactive extrusion KW - Large-scale production KW - Mechanochemistry KW - Zeolitic imidazolate framework PY - 2023 UR - https://twitter.com/NikitaGugin/status/1630538555675099139 AN - OPUS4-58951 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Gugin, Nikita T1 - Advancing Industrial Mechanochemistry: Real-Time Insights for Sustainable, Solvent-Free Manufacturing 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 thereactiveextrusion process, promoting its perception as an industrially feasible green alternative to traditional solventbased syntheses. T2 - #RSCPoster 2025 CY - Online meeting DA - 04.03.2025 KW - Mechanochemistry PY - 2025 AN - OPUS4-63803 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Gugin, Nikita T1 - Advancing Industrial Mechanochemistry: Real-Time Insights for Sustainable, Solvent-Free Manufacturing N2 - Reactive extrusion has emerged as a continuous approach for conducting mechanochemical reactions on a large scale. However, the use of this method under industrial conditions is hindered by limited understanding. In this study, we unveil the black box of reactive extrusion by employing energy-dispersive X-ray diffraction (EDXRD) to collect time- and spatially resolved in situ data. Our findings demonstrate the EDXRD method’s applicability to a range of chemical transformations and conditions associated with reactive extrusion. T2 - Chemie-Kolloquium & IfC Science Day CY - Berlin, Germany DA - 22.01.2025 KW - Mechanochemistry PY - 2025 AN - OPUS4-63801 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Meyerdierks, M. A1 - Schreiber, V. A1 - Böhne, Ch. A1 - Jüttner, S. A1 - Meschut, G. A1 - Rethmeier, Michael T1 - Validierung von Methoden zur Vermeidung von Liquid Metal Embrittlement an realitätsnahen Prinzipbauteilen (IGF 21483 BG / P 1488) N2 - Ziel des Forschungsprojekts ist es, eine Korrelation zwischen Gleeble-Heißzug-Prüfverfahren und Widerstandspunktschweiß-basierten Prüfverfahren herzustellen. Es soll die Effektivität von Methoden zu Vermeidung von Liquid Metal Embrittlement an realitätsnahen Prinzipbauteilen bewertet werden. Weiterhin soll Kenntnis über Auswirkungen von LME Rissen auf das Tragverhalten von realitätsnahen Prinzipbauteilen gewonnen werden. T2 - 30. Schweißtechnische Fachtagung CY - Barleben, Germany DA - 07.10.2021 KW - Liquid Metal Embrittlement KW - Gleeble KW - Heißzug KW - Widerstandpunktschweißen KW - Flüssigmetallversprödung PY - 2021 AN - OPUS4-54061 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Sternbaek, L. T1 - Macrophage-uptake of sialic acid-targeted molecularly imprinted polymers (SA-MIPs) N2 - Sialic acid (SA) is a cell surface glycan, which has a strong role in many cell activities including differentiation, proliferation, and the immune response. The amount of SA has been found to be correlated with cancer, with an upregulation on more aggressive cancers. Therefore, there is great interest in developing methods for detection of SA on cancer cells. We are screening SA on cancer cell lines by using fluorescent molecularly imprinted polymers, SA-MIPs.Macrophages, which evolve from mono-cytes, are well known for their extraordinary ability to phagocytose foreign objects. This could lead to the hypothesis that the SA-MIPs can be recognized by macrophages as foreign object; thus leading to internalization and potential degradation. We have discovered that SA-MIPs can be detected after incubation with the RAW macrophage cells, with increasing fluorescence over time. The microscopy analysis shows that the RAW cells ingest the SA-MIP particles. This information is important when planning to use SA-MIPs in future in vivo applications. T2 - The 69th Annual Conference of the Nordic Microscopy Society, 2018 CY - Lyngby, Denmark DA - 25.06.2018 KW - Sialic acid KW - MIPs KW - Macrophages PY - 2018 AN - OPUS4-45422 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kimani, Martha Wamaitha T1 - Fluorescent core/shell molecularly-imprinted nanoparticles for staining sialic acid (SA) residues on tumor cells N2 - Cancer is a leading cause of death worldwide, and its early detection and resultant treatment contributes significantly to patient recovery and survival. Detection is currently based on magnetic resonance imaging and computed tomography, methods that are expensive, while processing of the results is time consuming. There is a need for low-cost cancer-detection techniques that give conclusive results in the shortest time possible. Molecularly imprinted polymers (MIPs) targeting tumor markers on cancerous cells may provide a cheaper solution for cancer detection. Thin MIP layers immobilized on particle platforms are known to give faster response times and increased selectivity in comparison to bulk MIPs. It has been reported that a fluorescent monomer can be incorporated into the MIP layer, allowing for faster detection of the target group, thus significantly shortening the turn-around time for biopsies. Changes in sialylation patterns of cell surface glycoproteins indicate malignancy. Here, we present the development of MIPs that target sialic acid-terminated glycoproteins (SA MIPs), prepared as a thin layer on a silica nanoparticle platform. A fluorescent monomer is incorporated into the MIP layer, and upon binding of the target group to the specific binding pockets in the MIP, the fluorescence signal is enhanced. Transmission electron microscopy (TEM) and scanning electron microscopy (SEM) are used for structural characterization. To validate the specificity, fluorescence changes of MIPs in the presence and absence of template are compared to their corresponding non-imprinted polymer particles (NIP). Initial binding experiments with tumor cells using fluorescence microscopy demonstrate that the presented technique shows promise as a cheaper alternative to current detection methods, while allowing for relatively shorter analysis of biopsy results. T2 - MIP 2018 CY - Hebrew University Jerusalem, Belgium House, Israel DA - 24.07.2018 KW - Sialic acid KW - MIPs KW - Fluorescence PY - 2018 AN - OPUS4-45419 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Prabhakara, Prathik T1 - Ein synergistischer Ansatz zur Charakterisierung anisotroper Materialien mit Hilfe von Ultraschall und Mikrostrukturanalyse N2 - Es wird eine Studie zur Charakterisierung eines anisotropen Stahls vorgestellt, bei der Ultraschalluntersuchungen mit Mikrostrukturanalysen verbunden werden. Das Material weist hohe Festigkeit und Korrosionsbeständigkeit auf, zugleich ist mit anisotropen Eigenschaften die mechanischen und betrieblichen Eigenschaften beeinflussen zu rechnen. Vorläufige Ergebnisse lassen vermuten, dass weitere Untersuchungen notwendig sind, um die Fähigkeiten und Grenzen des Materials genau zu bestimmen. Es wird ein systematischer Ansatz mit Array- Prüfköpfen, Time-of-Flight Diffraction (TOFD) Technik und mikrostrukturellen Untersuchungen angewendet, um die Wechselwirkung zwischen Anisotropie und Mikrostruktur des Stahls zu analysieren. Ultraschallprüfungen mit der TOFD-Technik und in Tauchtechnik liefern Einblicke in das anisotrope Verhalten des Werkstoffes, einschließlich entsprechenden Kornorientierung, Dämpfung und Schallgeschwindigkeitsvariation. Diese Messungen führen in Verbindung mit mikrostrukturellen Analysen zu einem tieferen Verständnis des Materialverhaltens. Unser Hauptziel ist es, ein Framework zu erstellen, welches die Ultraschallantwort anisotroper Materialien mit ihren mikroskopischen Struktureigenschaften verbindet. Die vorgestellte Methodik ermöglicht eine zerstörungsfreie und zügige Bewertung der Materialintegrität, was besonders bei der Anwendung von Hochleistungsmaterialien relevant ist. Durch diesen integrativen Ansatz werden verschiedener Charakterisierungsmethoden kombiniert, um ein umfassenderes Materialverständnis zu erreichen. T2 - DGZfP-Jahrestagung 2024 CY - Osnabrück, Germany DA - 06.05.2024 KW - Ultrasonic Testing KW - Time-offlight Diffraction (TOFD) KW - Microstructure Analysis KW - Non-Destructive Testing PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-600122 UR - https://www.ndt.net/?id=29535 AN - OPUS4-60012 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Eggert, Lara T1 - Offshore-Reparaturbeschichtungen mit Chloridvorbelastung N2 - Bei maritimen Reparaturbeschichtungen ist eine chloridfreie Oberfläche nicht immer zu gewährleisten. Zur Untersuchung des Einflusses chloridhaltiger Verunreinigungen auf die Schutzwirkung maritimer Epoxid-Reparaturbeschichtungen wurden gestrahlte Stahlproben (Sa 2½) mit künstlichem Meerwasser besprüht. So entstanden drei Verunreinigungszustände: sauber (C0), leicht verunreinigt (C1) und stark verunreinigt (C2). Zwei Beschichtungen (A1 und A2) wurden appliziert und durch Ritzen und Impact-Schäden zusätzlich beansprucht. T2 - H2Mare-Abschlusskonferenz CY - Rostock, Germany DA - 23.09.2025 KW - Reperaturbeschichtung KW - Maritime Korrosion KW - Wechselzyklustest PY - 2025 AN - OPUS4-64235 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Reuter, T. T1 - Measurement-based Detector Characteristics for Digital Twins in aRTist 2 N2 - Various software products for the simulation of industrial X-ray radiography have been developed in recent years (e.g., aRTist 2, CIVA CT, Scorpius XLab, SimCT, Wilcore) and their application potential has been shown in numerous works. However, full systematic approaches to characterise a specific CT system for these simulation software products to obtain a truthful digital twin are still missing. In this contribution, we want to present two approaches to obtain realistic grey values in X-ray projections in aRTist 2 simulations based on measured projections. In aRTist 2, the displayed grey value of a pixel is based on the energy density incident on that pixel. The energy density is calculated based on the X-ray tube spectrum, the attenuation between source and detector as well as an energy-dependent sensitivity curve of the detector. The first approach presented in this contribution uses the sensitivity curve as a free modelling parameter. We measured the signal response at different thicknesses of Al EN-AW6082 at different tube voltages (i.e., different tube spectra). We then regarded the grey values displayed by these projections as a data regression respectively an optimisation problem and obtained the sensitivity curve that is best able to reproduce the measured behaviour in aRTist 2. The resulting sensitivity curve does not necessarily hold physical meaning but is able to simulate the real system behaviour in the simulation software. The second approach presented in this contribution is to estimate the sensitivity curve based on assumptions about the characteristics of the scintillation detector (e.g., scintillator material, scintillator thickness and signal processing characteristics). For this approach, a linear response function (linear relationship between the deposited energy per pixel and the resulting grey value) is assumed. If the detector characteristics, which affect the simulated deposited energy, are properly modelled, the slope and offset of the response function to match the measured grey values should be the same for different tube spectra. As the offset is constant and given by the grey values measured at no incident radiation, the slope is the remaining parameter to evaluate the success of the detector modelling. We therefore adapted the detector characteristics by changing the detector setup until the slope was nearly the same for all measured tube spectra. We are aware that the resulting parameters of the scintillator material and thickness might not be the real ones, but with those modelling parameters we are able to simulate realistic grey values in aRTist 2. Both of those approaches could potentially be a step forward to a full systematic approach for a digital twin of a real CT system in aRTist 2. T2 - 20th World Conference on Non-Destructive Testing (WCNDT 2024) CY - Incheon, South Korea DA - 27.05.2024 KW - Computed Tomography KW - Digital Twin KW - Simulation PY - 2024 AN - OPUS4-61776 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Feiler, Torvid A1 - Bhattacharya, Biswajit T1 - Mechanically flexible crystals: materials for new generation of responsive materials N2 - Based on the nature of the deformation, molecular crystals can be defined as being plastically (irreversible) or elastically (reversible)bendable. The mechanical response of crystals is thereby directly related to they structure.The structural elements required for a specific mechanical behavior are known, so that compounds with these properties can be synthesized by applying the rules of crystal engineering. T2 - Berlin Science Week CY - Berlin, Germany DA - 01.11.2021 KW - Flexible crystals PY - 2021 AN - OPUS4-53907 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Braun, U. T1 - Detection of plastics in soil N2 - Soil acts as a final sink for pollutants. Microplastics from different sources such as plastic mulching, littering, compost, sewage sludge, sedimentary deposition, and tyre abrasion are expected to be found in soil. However, representative and comprehensive information is missing on the sources, transport, and fate. Therefore, a reliable analysis method for microplastics in soils needs to be developed. The presented work describes the development of a procedure for microplastics analysis in soils. A representative sampling based on the on-site conditions and a sample preparation method was established and comprised of a drying step, the separation of microplastic particles > 1 mm, and a density separation for particles < 1 mm. The detection of the large microplastic particles (> 1 mm) was conducted with Attenuated Total Reflection - Fourier Transform infrared Spectroscopy (ATR-FTIR) , while Thermal Extraction Desorption - Gas Chromatography / Mass Spectrometry (TED-GC/MS) was applied for particles < 1 mm, gaining information on the type of polymer and mass fraction. Based on the established method, 14 environmental soil samples ? with different exposure of microplastics from agriculture, industrial sites, roads, and floods were investigated. Due to the arbitrary microplastic particle distribution among the samples for large microplastics, it was reasoned that the found particles were unrepresentative. In contrast, microplastic particles < 1 mm were discovered in a high mass in soil samples exposed to plastic mulching or fertilization with sewage sludge or compost (0 – 115 mg/kg). On average, microplastic contents detected in soil samples taken from a construction site and an inner-city lake were higher (13 – 238 mg/kg). As expected, microplastic content in soil sampled in proximity to roads was more pronounced in the upper soil layers. In contrast, very remote sampling sites, expectably uncontaminated, did not lead to the detection of microplastic regarding to thermoanalytical detection method. In a proof of concept experiment several in vivo and in vitro ecotoxicological tests were applied to evaluate the effect of microplastics (tyre abrasion, polystyrene containing hexabromocyclododecane) in natural soils. In summary, while no effects of the examined probes could be detected on higher levels of biological organization after exposures to earthworm E. andrei, significant changes in several oxidative stress related biomarkers were observed. T2 - SETAC Europe 2022 CY - Kopenhagen, Denmark DA - 15.05.2022 KW - Microplastic KW - TED-GC/MS KW - Soil PY - 2022 AN - OPUS4-55872 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Dittmann, Daniel T1 - Aktivkohle-Charakterisierung als weiterer Schlüssel für das Verständnis der Spurenstoffadsorption in der 4. Reinigungsstufe N2 - Aktivkohle ≠ Aktivkohle, Adäquate Materialcharakterisierung - Voraussetzung für Adsorptionsprognosen und Wasserspezifische Auswahl von Aktivkohleprodukten. Ausblick: Publikationen zu Aktivkohlecharakterisierung und Adsorptionsprognose in Vorbereitung T2 - Wasser 2021 - Jahrestagung der Wasserchemischen Gesellschaft CY - Online meeting DA - 10.05.2021 KW - Aktivkohle KW - Thermogravimetrie KW - Zersetzungsgasanalyse KW - Proximatanalyse PY - 2021 AN - OPUS4-52742 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Linberg, Kevin T1 - Tipping the Energy Scales to Control Mechanochemical Polymorphism N2 - Control of ball milling conversions is required before the full potential of mechanochemical processing can be realized. It is well known that many parameters affect the outcome of mechanochemical polymorphism, but the energy of ball milling itself is often overlooked. We show here how this parameter alone can exert a significant influence on the polymorphic outcome of ball mill grinding by allowing the selective isolation of two polymorphic forms in their pure form under the same grinding conditions. Furthermore, we show how apparent mechanochemical equilibria can be deceptive. Our results clearly demonstrate the need for careful design and interpretation of ball milling experiments beyond current thinking. T2 - SALSA make and measure CY - Online meeting DA - 16.09.2021 KW - Mechanochemistry KW - Energy KW - Polymorph KW - Cocrystal PY - 2021 AN - OPUS4-53293 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Feiler, Torvid T1 - Polymorphic tuning of a flexible organic crystal optical waveguide N2 - Crystalline molecular materials are usually brittle and are prone to break upon external mechanical force. This fragility poses challenges for their application in next-generation technologies, including sensors, synthetic tissues, and advanced opto-electronics. The recent discovery of mechanical flexibility in single crystals of molecular materials has solved this problem and enable the design of smart flexible device technologies. Mechanical flexibility of organic crystals can be tuned by altering the weak interactions in the crystal structure, for examples through polymorphism. Here we report 4-bromo-6-[(6-chlorolpyridin-2-ylimino)methyl]phenol (BCMPMP) as a promising candidate for future waveguide technologies. It turns out that BCMPMP has two different polymorphs with distinct optical and mechanical properties. Form I shows brittle behavior under mechanical stress and exhibits very weak emission at 605 nm (λex = 425 nm) together with a low fluorescence quantum yield (Φ = 0.4 %).In contrast, Form II has a large plastic (irreversible bending) regime and a bright emission at 585 nm (λex = 425 nm; Φ = 8.7 %). Making use of favorable mechanical fexiblity and optical properties, form II was explored as a bendable optical waveguide. Light was successfully propagated through a straight-shaped and mechanically deformed BCMPMP crystal. Depending on the light source, active or passive waveguiding could be achieved. So BCMPMP can also be used as a flexible wavelength filter. T2 - Congress of the International Union of Crystallography - IUCr 2021 CY - Online meeting DA - 14.08.2021 KW - Flexible crystals KW - Polymorphism KW - Waveguide PY - 2021 AN - OPUS4-53906 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -