TY - CONF A1 - Becker, Tina T1 - Emissivity – Gamechanger for quantitative in-situ monitoring N2 - For a deep process understanding of the laser powder bed fusion process (PBF-LB/M), recording of the occurring surface temperatures is of utmost interest and would help to pave the way for reliable process monitoring and quality assurance. A notable number of approaches for in-process monitoring of the PBF-LB/M process focus on the monitoring of thermal process signatures. However, due to the elaborate calibration effort and the lack of knowledge about the occurring spectral directional emissivity, only a few approaches attempt to measure real temperatures. In this study, to gain initial insights into occurring in the PBF-LB/M process, measurements on PBF-LB/M specimens and metal powder specimens were performed for higher temperatures up to T = 1290 °C by means of the emissivity measurement apparatus (EMMA) of the Center for Applied Energy Research (CAE, Wuerzburg, Germany). Also, measurements at ambient temperatures were performed with a suitable measurement setup. Two different materials—stainless steel 316L and aluminum AlSi10Mg—were examined. The investigated wavelength λ ranges from the visible range (λ-VIS = 0.40–0.75 µm) up to the infrared, λ = 20 µm. The influence of the following factors were investigated: azimuth angle φ, specimen temperature TS, surface texture as for PBF-LB/M surfaces with different scan angles α, and powder surfaces with different layer thicknesses t. T2 - Rapid.Tech 3D 2024 CY - Erfurt, Germany DA - 14.05.2024 KW - PBF-LB/M KW - In situ monitoring KW - Emissivity KW - Additive Manufacturing PY - 2024 AN - OPUS4-60148 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Breese, Philipp Peter A1 - Becker, Tina A1 - Oster, Simon A1 - Metz, C. A1 - Altenburg, Simon T1 - In-situ defect detection for laser powder bed fusion with active laser thermography N2 - Defects are still common in metal components built with Additive Manufacturing (AM). Process monitoring methods for laser powder bed fusion (PBF-LB/M) are used in industry, but relationships between monitoring data and defect formation are not fully understood yet. Additionally, defects and deformations may develop with a time delay to the laser energy input. Thus, currently, the component quality is only determinable after the finished process. Here, active laser thermography, a nondestructive testing method, is adapted to PBF-LB/M, using the defocused process laser as heat source. The testing can be performed layer by layer throughout the manufacturing process. We study our proposed testing method along experiments carried out on a custom research PBF-LB/M machine using infrared (IR) cameras. Our work enables a shift from post-process testing of components towards in-situ testing during the AM process. The actual component quality is evaluated in the process chamber and defects can be detected between layers. T2 - 2023 International Solid Freeform Fabrication Symposium CY - Austin, TX, USA DA - 14.08.2023 KW - Additive Manufacturing KW - Laser Powder Bed Fusion KW - Nondestructive Testing KW - Thermography KW - Defect Detection PY - 2023 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-606288 DO - https://doi.org/10.26153/tsw/51096 SP - 1978 EP - 1989 PB - University of Texas at Austin CY - Austin, TX, USA AN - OPUS4-60628 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Becker, Amadeus A1 - Schröpfer, Dirk A1 - Kromm, Arne A1 - Kannengießer, Thomas T1 - Determination of residual stress evolution during repair welding of high-strength steel components N2 - During the assembly of steel structures, unacceptable weld defects may be found. An economical solution is local thermal gouging of the affected areas and re-welding. Due to high shrinkage restraints of repair weld and sur- rounding structure, high global and local welding stresses superimpose, and may lead to cracking and component failure, especially in connection with the degraded microstructure and mechanical properties of high-strength steels during the repair process. Component-related investigations of high-strength steels (FOSTA P1311/ IGF20162N) focus on welding residual stress evolution during local thermal gouging and rewelding. In this study, repair welding of S500MLO (EN 10225) is carried out using in-situ digital image correlation (DIC) and ex- situ X-ray diffraction (XRD) to analyse strains and stresses. Self-restrained slit specimen geometries were identified representing defined rigidity conditions of repair welds of real components, which were quantified using the restraint intensity concept. The specimens were rewelded with constant welding heat control and parameters. Weld specimens exhibited significantly increased transverse residual stresses with higher transverse restraint intensities, in the weld metal, and in the heat affected zone. Transverse stresses along the weld seam decrease at the weld seam ends leading to different stress state during gouging and welding. XRD analysis of the longitudinal and transverse local residual stresses after cooling to RT showed a good comparability with global DIC analyses. KW - Repair-welding KW - High-strength steels KW - X-ray diffraction KW - Digital image correlation KW - Residual stresses PY - 2022 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-555672 DO - https://doi.org/10.1016/j.finmec.2022.100073 SN - 2666-3597 VL - 6 SP - 1 EP - 6 PB - Elsevier CY - Amsterdam AN - OPUS4-55567 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Becker, Roland T1 - Reference materials for microplastics in environmental matrices N2 - The pollution of marine, limnic and terrestrial environments with plastic waste and the potential impact especially on biota and humans has received increasing attention in recent years. Special focus is on particles smaller than 5 mm, the so-called microplastics. Consequently, possible regulations of emission and remediation efforts require sound information on the occurrence and fate of microplastics in the respective environmental compartments. Microplastics (MP) differ from classical organic pollutants in biota or the environment in that they do not consist of clearly defined low-molecular weight compounds but of polymer particulates with varying sizes and chemical compositions. This leads to specific challenges regarding the analytical techniques to be employed for their identification and quantification. Microplastics are defined as polymer particle in the size range between 1 µm and 5 mm and cover a wide range of polymers such as polyethylene, polypropylene, polystyrene and polyethylene terephthalate in variable geometric shapes. Properties relevant for environmental microplastics are polymer type, particle form and size distribution, surface morphology (aging status) and total mass fraction contained in a given sample. Polymer identification and particle size estimation using optical methods (IR and Raman spectroscopy) are time consuming and complicated by surface characteristics as a result of weathering, soiling, and microbial colonisation. Total mass fractions of MP in environmental samples can be determined by thermo-analytical methods. There are currently no standardised methods for sampling, sampling preparation, or detection of MP in environmental samples. So far, qualitative and quantitative investigations are done by research institutes and have not reached the routine laboratory community. The near future will see harmonisation efforts of MP mass fraction determination in environmental matrices by thermo-analytical procedures. The immediate need for reference materials during method development and comparison is outlined with regard to relevant matrix/polymer compositions, existing regulations and currently achievable detection limits. Examples for solid environmental matrix reference materials are discussed regarding the challenges encountered with matrices and polymer types as well as homogeneity testing and property value characterisation. T2 - BERM 2018 15th International Symposium on Biological and Environmental Reference Materials CY - Berlin, Germany DA - 23 September 2018 KW - Referenzmaterialien KW - Schwebstoffe KW - Sediment KW - Polymer PY - 2018 AN - OPUS4-46209 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Becker, Ben T1 - Zustandsüberwachung von Composite-Druckgefäßen mit faseroptischer Sensorik N2 - Einsatz der Faseroptik zur Zustandsüberwachung von Composite-Druckgefäßen. Aufbau, Integration, Messergebnisse. T2 - Follow-up Workshop on Statistical Safety Assessment of Composite Cylinders CY - Berlin, Germany DA - 05.10.2016 KW - Faseroptik KW - Zustandsüberwachung KW - Composite-Druckgefäße PY - 2016 AN - OPUS4-39088 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Becker, Amadeus T1 - Adequate repair concepts for high-strength steel weld joints considering design influences N2 - The sustainable and resource-efficient production of wind energy plants requires the use of modern high-strength fine-grain structural steels. This applies to both foundation and erection structures. During the assembly of steel structures, unacceptable defects can occasionally be found in the weld area. In most cases, the economical solution would be local thermal gouging of the affected areas and re-welding. Due to the high shrinkage restraint of the joint groove in the overall structure, the superposition of design and welding-induced residual stress can lead to crack formation and ultimately to component failure, particularly in interaction with the degradation of the microstructure and mechanical properties high-strength steels during the repair process. In this context, component-related investigations (FOSTA-P1311/IGF-Nr. 20162 N) focusing on welding residual stress evolution during local thermal gouging and rewelding of S500MLO and S960QL are carried out using in-situ digital image correlation (DIC) and ex-situ X-ray diffraction methods (XRD). Therefore, self-restrained specimens were systematically gouged and rewelded with defined welding heat control (heat input, working temperature) and parameters. By means of structural mechanics calculations, geometries of self-restrained specimens were identified, that represent defined rigidity conditions of repair welds of real components. It could be shown that with increasing restraint intensity significantly higher residual stresses occur in the weld metal and heat affected zone. Furthermore, it revealed that the transverse stresses along the weld seam decrease at the weld seam ends leading to different stress state during gouging and welding. XRD analysis of the local residual stresses after cooling to RT longitudinal and transverse to the weld direction showed a good comparability with global DIC analyses. T2 - Bachelor-, Master-, Doktoranden-Kolloquium der Otto-von-Guericke Universität Magdeburg CY - Magdeburg, Germany DA - 20.10.2021 KW - High-strength steels KW - Repair welding KW - X-ray diffraction KW - Digital image correlation PY - 2021 AN - OPUS4-53640 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Becker, Amadeus T1 - Beanspruchungsgerechte Reparatur beim Bauteilschweißen hochfester Feinkornbaustähle N2 - Eine nachhaltige und ressourceneffiziente Fertigung und Errichtung von Windenergieanlagen, sowohl auf See als auch an Land, erfordert zunehmend den Einsatz moderner hochfester Feinkornbaustähle. Werden nach dem Schweißen dieser hochfesten Konstruktionen unzulässige Defekte detektiert, sind nach geltenden Verarbeitungsrichtlinien die defekten Bereiche durch lokales Ausfugen und anschließendes Schweißen zu reparieren. Fehlende Informationen zu adäquaten Reparaturkonzepten in den Regelwerken bedingen oftmals eine unzureichende Berücksichtigung dabei auftretender zusätzlicher Beanspruchungen durch die erhöhte Schrumpfbehinderung der Ausfugenuten. Zusätzlich haben die ausführenden Betriebe vielfach kaum Kenntnis über die Degradation angrenzender Gefüge durch thermische Ausfugeprozesse und erneutes Schweißen, die in diesem Zusammenhang besonders bei den hochfesten Stählen als kritisch anzusehen sind. Das aktuelle Forschungsvorhaben der BAM (FOSTA P1311/IGF-Nr.20162N) fokussiert hierfür systematisch bauteilrelevante Untersuchungen zu den schweißbedingten Beanspruchungen und Gefügeveränderungen bei der Reparatur von hochfesten Schweißverbindungen. Wesentlich sind hierbei der Einfluss der Schrumpfbehinderung, der Wärmeführung beim Schweißen und Ausfugen sowie der Reparaturzyklenanzahl und die metallurgischen Aspekte bei den hochfesten Güten S500MLO für zukünftige Offshore-Anwendungen und S960QL für aktuelle Mobilkrananwendungen. Aufbauend auf einigen Studien zur schweißbedingten Beanspruchung hochfester Stähle zeigt der vorliegende Beitrag die Identifikation geeigneter Probengeometrien und Schweißdetails mittels numerischer und experimenteller Analysen. Dadurch wird die Übertragbarkeit der vorgestellten Schweißexperimente und Ergebnisse hinsichtlich der resultierenden Schweißeigenspannungen auf reale Reparaturfälle im Bereich des hochfesten Stahlbaus sichergestellt. Es zeigt sich in Übereinstimmung mit früheren Ergebnissen eine signifikante Erhöhung der Beanspruchungen an den variierten schlitzförmigen Prüfnähten. Das Eigenspannungsniveau sowohl im Schweißgut als auch in der WEZ korreliert mit dem Einspanngrad. Mit dem Ziel beanspruchungs- und werkstoffgerechte Reparaturkonzepte zu erarbeiten, sind zum einen geringere Wärmeinbringungen, besonders durch niedrige Zwischenlagentemperaturen und Einspannbedingungen anzustreben, um hohe Beanspruchungen und kritische Gefügedegradationen im Reparaturbereich zu vermeiden. Dies wird durch systematische Untersuchungen zum Ausfugen und Schweißen sowie letztlich dem Transfer von Verarbeitungsempfehlungen für die Anwender und Richtlinien erreicht. T2 - DVS Congress 2021 CY - Essen, Germany DA - 14.09.2021 KW - Eigenspannungen KW - Hochfest KW - Feinkornbaustahl KW - Reparatur KW - Schweißen PY - 2021 AN - OPUS4-53317 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Becker, Amadeus T1 - Consideration of design influences to provide adequate repair concepts for high-strength steel weld joints in offshore support structures N2 - The sustainable and resource-efficient production of offshore wind turbines requires the use of modern high-strength fine-grained structural steels (Martin and Schroeter, 2005). This applies to wind turbines in terms of increasing turbine sizes as well as to maintenance and installation vessels and equipment (Ummenhofer et al., 2013). Without the demanded high load-bearing capacities and boom lengths, the economic realization of these goals would be inconceivable. During the assembly of high-strength steel structures, unacceptable defects can occasionally be found in the weld area, although the welding process was executed in accordance with the specifications. In most cases, the economical solution would be local thermal gouging of the affected areas and re-welding. Corresponding standards hardly provide any information on adequate repair concepts, and there is no uniform scientific data on which to base such concepts. This applies particularly to the consideration and optimization of welding-induced stresses due to the high shrinkage hindrance of the gouging grooves and degradation of the adjacent microstructures by gouging and re-welding. The result, especially in the case of high-strength steel grades, are frequently recurring imperfections as well as a missing consideration of the additionally induced welding stresses in the design of the structure. In this context, at BAM component-relevant investigations focused on welding residual stress evolution and microstructural degradation during repair of weld joints due to local thermal gouging and re-welding are carried out within the scope of a FOSTA project (P1311, IGF 20162N). In this study, several relevant findings are discussed based on examples of structural engineering focusing on mechanical-technological properties and residual stresses, for instance found by (Schasse, 2017). Also experimental and numerical work as conducted by (Wongpanya, 2008) and weld tests under defined shrinkage restraint in special weld test-setups for research projects, e. g. FOSTA-P922 (Kannengiesser and Schroepfer, 2015) and P1011 (Kannengiesser and Schroepfer, 2017) have shown that an optimization of the welding-induced stresses of high-strength structural steels is specifically achievable by means of adapted heat control concepts (Schroepfer, 2017). The present research involves systematic investigations of influences of shrinkage restraint, the number of repair cycles and heat control during repair welding of the relatively new developed offshore-relevant high-strength steel S500MLO (EN 10225-1). For the quantification of the shrinkage restraint of weld joints, the concept of restraint intensity established by (Satho et al., 1973) was applied analogous to recent research, e. g. (Schwenk et al., 2008). By means of structural mechanics calculations, geometries of self-strained specimens were identified, that represent different defined rigidity conditions of repair welds of real components, cf. Fig. 1. It could be shown that with increasing weld joint restraint intensity significantly higher residual stresses in the weld metal and heat affected zone up to 80 % of the nominal yield strength occur, cf. Fig. 2. In relation to existing results, it has been shown that a safe repair of such welds can only be achieved by means of appropriate repair concepts and heat control taking the high welding stresses and special microstructures of high-strength steels into account. Finally, the aim of this research is to derive recommendations for repair concepts appropriate to the stresses and materials involved providing a basis for standards and guidelines, especially for SMEs, in order to avoid damage and, in most cases, expensive reworking and to improve the full utilization of the potential of high-strength steels. T2 - Wind Energy Science Conference 2021 CY - Online meeting DA - 25.05.2021 KW - High-strength structural steels KW - Welding KW - Repair KW - Residual stresses KW - Restraint PY - 2021 AN - OPUS4-53319 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Becker, Amadeus T1 - Konstruktive Einflüsse bei der beanspruchungsgerechten Reparatur geschweißter Bauteile aus hochfesten Feinkornbaustählen N2 - Bei der Montage von Stahlkonstruktionen kommt es trotz anforderungsgerechter schweißtechnischer Fertigung vereinzelt zur Detektion von unzulässigen Unregelmäßigkeiten im Schweißbereich. Die Verarbeitungsregelwerke empfehlen das lokale thermische Ausfugen betroffener Bereiche und erneutes Schweißen, geben aber aufgrund fehlender wissenschaftlich fundierter Untersuchungen kaum Informationen zu adäquaten Reparaturkonzepten. Dies betrifft insbesondere die Berücksichtigung und Optimierung resultierender schweißbedingter Beanspruchungen durch hohe Schrumpfbehinderungen der Ausfugenuten sowie der Gefügedegradation angrenzender Bereiche durch das Ausfugen und erneute Schweißen. Gerade bei hochfesten Stahlgüten ergeben sich dadurch häufig reduzierte mechanische Eigenschaften und zusätzliche schweißbedingte Beanspruchungen sowie erneut auftretende Nahtdefekte. Deshalb sind für das Forschungsvorhaben systematische bauteilrelevante Untersuchungen der schweißbedingten Beanspruchungen und Gefügeveränderungen reparierter Schweißnähte in Abhängigkeit von der Schrumpfbehinderung und Wärmeführung beim Schweißen und Ausfugen sowie von der Reparaturzyklenanzahl geplant, mit dem Ziel Empfehlungen für beanspruchungs- und werkstoffgerechte Reparaturkonzepte abzuleiten. Hierfür sind gerade Analysen an hochfesten Stahlgüten S500 für den Offshore-Bereich und S960QL für den Mobilkranbau interessant, die zur Errichtung und Fertigung hocheffizienter Konstruktionen wie Windenergieanlagen notwendig sind. Die Erkenntnisse bieten eine Grundlage für entsprechende Normen und Regelwerke. Damit können letztlich Schäden und zumeist teure Nacharbeiten verhindert und eine verbesserte Ausnutzung des hohen Festigkeitspotentials hochfester Stähle erreicht werden. Gerade auch KMU können mit Blick auf die Kosten für Fertigung, Schweißarbeit und Material von den Erkenntnissen beim Einsatz hochfester Stähle, die für eine effiziente Realisierung der Energiewende in Deutschland notwendig sind, profitieren. T2 - Bachelor-, Master-, Doktoranden-Kolloquium der Otto-von-Guericke Universität Magdeburg CY - Online meeting DA - 17.06.2021 KW - Eigenspannungen KW - Hochfest KW - Feinkornbaustahl KW - Reparatur KW - Schweißen PY - 2021 AN - OPUS4-53318 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Becker, Amadeus A1 - Schröpfer, Dirk A1 - Kannengießer, Thomas T1 - Beanspruchungsgerechte Reparatur beim Bauteilschweißen hochfester Feinkornbaustähle N2 - Eine nachhaltige und ressourceneffiziente Fertigung und Errichtung von Windenergieanlagen, sowohl auf See als auch an Land, erfordert zunehmend den Einsatz moderner hochfester Feinkornbaustähle. Werden nach dem Schweißen dieser hochfesten Konstruktionen unzulässige Defekte detektiert, sind nach geltenden Verarbeitungsrichtlinien die defekten Bereiche durch lokales Ausfugen und anschließendes Schweißen zu reparieren. Fehlende Informationen zu adäquaten Reparaturkonzepten in den Regelwerken bedingen oftmals eine unzureichende Berücksichtigung dabei auftretender zusätzlicher Beanspruchungen durch die erhöhte Schrumpfbehinderung der Ausfugenuten. Zusätzlich haben die ausführenden Betriebe vielfach kaum Kenntnis über die Degradation angrenzender Gefüge durch thermische Ausfugeprozesse und erneutes Schweißen, die in diesem Zusammenhang besonders bei den hochfesten Stählen als kritisch anzusehen sind. Das aktuelle Forschungsvorhaben der BAM (FOSTA P1311/IGF-Nr.20162N) fokussiert hierfür systematisch bauteilrelevante Untersuchungen zu den schweißbedingten Beanspruchungen und Gefügeveränderungen bei der Reparatur von hochfesten Schweißverbindungen. Wesentlich sind hierbei der Einfluss der Schrumpfbehinderung, der Wärmeführung beim Schweißen und Ausfugen sowie der Reparaturzyklenanzahl und die metallurgischen Aspekte bei den hochfesten Güten S500MLO für zukünftige Offshore-Anwendungen und S960QL für aktuelle Mobilkrananwendungen. Aufbauend auf einigen Studien zur schweißbedingten Beanspruchung hochfester Stähle zeigt der vorliegende Beitrag die Identifikation geeigneter Probengeometrien und Schweißdetails mittels numerischer und experimenteller Analysen. Dadurch wird die Übertragbarkeit der vorgestellten Schweißexperimente und Ergebnisse hinsichtlich der resultierenden Schweißeigenspannungen auf reale Reparaturfälle im Bereich des hochfesten Stahlbaus sichergestellt. Es zeigt sich in Übereinstimmung mit früheren Ergebnissen eine signifikante Erhöhung der Beanspruchungen an den variierten schlitzförmigen Prüfnähten. Das Eigenspannungsniveau sowohl im Schweißgut als auch in der WEZ korreliert mit dem Einspanngrad. Mit dem Ziel beanspruchungs- und werkstoffgerechte Reparaturkonzepte zu erarbeiten, sind zum einen geringere Wärmeinbringungen, besonders durch niedrige Zwischenlagentemperaturen und Einspannbedingungen anzustreben, um hohe Beanspruchungen und kritische Gefügedegradationen im Reparaturbereich zu vermeiden. Dies wird durch systematische Untersuchungen zum Ausfugen und Schweißen sowie letztlich dem Transfer von Verarbeitungsempfehlungen für die Anwender und Richtlinien erreicht. T2 - DVS Congress 2021 CY - Online meeting DA - 14.09.2021 KW - MAG-Schweißen KW - Reparatur KW - Eigenspannungen KW - Hochfester Stahl KW - Thermisches Ausfugen KW - Windenergie KW - Gefügedegradation PY - 2021 SN - 978-3-96144-146-4 VL - 371 SP - 285 EP - 292 PB - DVS Media GmbH CY - Düsseldorf AN - OPUS4-56666 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Ahiboz, D. A1 - Andresen, Elina A1 - Manley, P. A1 - Resch-Genger, Ute A1 - Würth, Christian A1 - Becker, C. T1 - Enhanced photon upconversion using erbium-doped nanoparticles interacting with silicon metasurfaces N2 - Photon upconversion (UC) using trivalent erbium (Er+3) doped crystals is a promising concept to harness near infrared photons of the solar spectrum which cannot be directly absorbed by silicon solar cells. However, their UC efficiency at low-intensity 1 sun illumination is not relevant on device level so far. Exploiting giant near-field enhancement effects on metasurfaces is an appealing approach to enable efficient UC at low irradiance conditions. Here, we report on more than 1000-fold enhanced photon UC of NaYF4:Er+3 nanoparticles interacting with the near-fields supported by a silicon metasurface under 1550 nm excitation. T2 - 48th Photovoltaic Specialists Conference (PVSC) CY - Online meeting DA - 20.06.2021 KW - Nano KW - Nanomaterial KW - Upconversion nanoparticle KW - Lanthanide KW - Photoluminescence KW - Quantum yield KW - Photophysics KW - Lifetime KW - Sensor KW - Excitation power density KW - Brightness KW - NIR KW - Mechanism KW - Modeling KW - Simulation KW - Energy transfer KW - Photonic crystal KW - Enhancement strategy PY - 2021 DO - https://doi.org/10.1109/pvsc43889.2021.9518495 SP - 1 EP - 3 PB - IEEE CY - Berlin AN - OPUS4-53786 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Huang, M.D. A1 - Becker-Ross, H. A1 - Okruss, M. A1 - Geisler, S. A1 - Florek, S. A1 - Richter, Silke A1 - Meckelburg, Angela T1 - Direct determination of fluorine in niobium oxide using slurry sampling electrothermal high-resolution continuum source molecular absorption spectrometry N2 - Aiming for a round-robin test, a new method for the direct determination of fluorine in niobium oxide has been developed. It is based on the use of high-resolution molecular absorption spectra of calcium mono-fluoride (CaF) generated in the graphite tube, combined with the slurry sampling technique. The absorption measurement was performed at the 606.44 nm CaF rotational line. By using graphite tubes with zirconium carbide (ZrC) modified platform, the molecular absorption sensitivity of CaF has been improved by a factor of 20, and no additional chemical modifier was necessary. Generally, non-spectral interferences were observed in the presence of HCl, H2SO4, and H3PO4. For HCl, additional spectral interference occurred due to an overlap of the absorption spectra of CaF and CaCl. However, due to the absence of these mentioned substances in the current material, such interferences do not exist for this application. The characteristic mass found for the CaF 606.44 nm line was 0.1 ng; the limit of detection was 5 mg fluorine per kg solid sample (3σ criterion). The results obtained by the method were within the range of certified values. Comparing to the classical method such as the pyrohydrolysis-photometric method, the developed new method showed clear advantages regarding sensitivity and specificity. The time requirement for one sample analysis was strongly shortened from several hours to only some minutes. KW - Continuum source molecular absorption spectrometry KW - Fluorine determination KW - Niobium oxide KW - Slurry sampling PY - 2014 DO - https://doi.org/10.1016/j.sab.2014.02.005 SN - 0584-8547 SN - 0038-6987 VL - 94-95 SP - 34 EP - 38 PB - Elsevier CY - Amsterdam AN - OPUS4-30655 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Ahiboz, D. A1 - Andresen, Elina A1 - Manley, P. A1 - Resch-Genger, Ute A1 - Würth, Christian A1 - Becker, C. T1 - Metasurface-Enhanced Photon Upconversion upon 1550 nm Excitation N2 - Photon upconversion upon 1550 nm excitation is of high relevance for applications in the third biological excitation window, for photovoltaics beyond current limitations, and enables appealing options in the field of glass Fiber telecommunications. Trivalent doped erbium ions (Er3+) are the material of choice for 1550 nm excited upconversion, however, they suffer from a low absorption cross-section and a low brightness. Therefore, the ability of Silicon metasurfaces to provide greatly enhanced electrical near-fields is employed to enable efficient photon upconversion even at low external Illumination conditions. Hexagonally shaped β-NaYF4:Er3+ nanoparticles are placed on large-area silicon metasurfaces designed to convert near-infrared (1550 nm) to visible light. More than 2400-fold enhanced photon upconversion luminescence is achieved by using this metasurface instead of a planar substrate. With the aid of optical simulations based on the finite-element method, this result is attributed to the coupling of the excitation source with metasurface resonances at appropriate incident angles. Analysis of the excitation power density dependence of upconversion luminescence and red-to-green-emission ratios enables the estimation of nanoscale near-field enhancement on the metasurface. The findings permit the significant reduction of required external excitation intensities for photon upconversion of 1550 nm light, opening perspectives in biophotonics, telecommunication, and photovoltaics. KW - Nano KW - Nanomaterial KW - Upconversion nanoparticle KW - Lanthanide KW - Photoluminescence KW - Quantum yield KW - Photophysics KW - Lifetime KW - Sensor KW - Excitation power density KW - Single particle KW - Brightness KW - NIR KW - Mechanism KW - Single enhancement KW - SWIR KW - Method PY - 2021 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-537193 DO - https://doi.org/10.1002/adom.202101285. SN - 2195-1071 VL - 9 IS - 24 SP - 2101285 PB - Wiley-VCH-GmbH AN - OPUS4-53719 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Becker, Roland A1 - Koch, Matthias A1 - Lehnik-Habrink, Petra A1 - Nehls, Irene T1 - Quantification of polychlorinated biphenyls in plastic granulates from the recycling of cables - Reference materials and interlaboratory comparison N2 - A procedure for the quantification of the PCB marker congeners 28, 52, 101, 138, 153, 180 in plastic waste form the recycling of cables in the range of content between 0.1 mg kg-1 and 20 mg kg-1 was validated. Representative reference materials for laboratory analyses were produced using granulates from different recycling processes. The method development included aspects of grinding, sieving, homogenising as well as the comparison of extraction methods and chromatographic conditions. The validated procedure foresees grinding of the technical sample to an upper particle size limit of 0.50 mm followed by extraction with an unpolar solvent such as n-hexane and gas chromatographic determination. LOD and LOQ for individual congeners ranged between 0.01 mg kg-1 and 0.08 mg kg-1. Electron capture detection (ECD) and mass selective detection (MS) were equivalent if chromatographic conditions were appropriately selected. The application of MS was advantageous in presence of significant amounts of interfering components which have been found in some cables. Three reference materials containing the marker congeners in the range of 0.1 mg kg-1–5 mg kg-1 were submitted to a final validation intercomparison with 23 selected field laboratories using the developed method. Relative reproducibility standard deviations varied between 15% and 33%. KW - PCB KW - Waste KW - Analysis KW - Method validation KW - Standardisation PY - 2006 DO - https://doi.org/10.1016/j.chemosphere.2006.02.035 SN - 0045-6535 SN - 0366-7111 VL - 65 IS - 9 SP - 1652 EP - 1659 PB - Elsevier Science CY - Kidlington, Oxford AN - OPUS4-14050 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - RPRT A1 - Becker, Roland A1 - Koch, Matthias A1 - Buge, Hans-Georg A1 - Nehls, Irene T1 - Entwicklung eines Referenzverfahrens zur Quantifizierung von polychlorierten Biphenylen (PCB) in Kunststoffgranulaten N2 - Im Rahmen eines vom Bundesministerium für Wirtschaft und Arbeit (BMWA) geförderten Projektes wird in Kooperation mit dem Verband deutscher Metallhändler (VDM) ein Verfahren zur Quantifizierung der PCB-Kongenere 28, 52, 101, 138, 153, 180 im Gehaltsbereich von 0,1 bis 20 mg in Kunststoffabfällen aus dem Altkabelrecycling entwickelt und validiert. Dazu werden repräsentative Referenzmaterialien für die Laboranalytik aus Granulaten verschiedener Kabelzerlegeprozesse hergestellt und charakterisiert. Die Methodenentwicklung umfasst mahl-, sieb- und schüttguttechnologische Aspekte sowie den Vergleich unterschiedlicher Extraktionsverfahren und chromatographischer Bedingungen. Das validierte Verfahren sieht die Mahlung der technischen Probe auf eine Kornobergrenze von 0,50 mm gefolgt von Extraktion mit einem unpolaren Lösungsmittel bei einer Einwaage von 4 g und gaschromatographischer Bestimmung vor. Die Bestimmungsgrenzen liegen zwischen 0,01 und 0,08 mg/kg. Bei sorgfältiger Wahl der chromatographischen Bedingungen sind Elektroneneinfang- und massenselektive Detektion (MS) gleichwertig. In Gegenwart größerer Mengen bestimmter Komponenten, die in einigen Kabeln enthalten sind, kann der Einsatz eines MS von Vorteil sein. Drei Referenzmaterialien mit Gehalten der genannten Kongenere zwischen 0,1 bis 5 mg/kg werden in einem abschließenden Ringversuch zur Validierung dieser Methode mit 23 ausgewählten Laboratorien eingesetzt. Dabei ergeben sich für die Quantifizierung dieser Kongenere relative Vergleichsstandardabweichungen zwischen 15 und 33 %. Das Verfahren wird in die europäische Normung (CEN 292 „Characterisation of Waste“) eingebracht. T3 - BAM Forschungsberichtreihe - 270 PY - 2005 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-1810 SN - 978-3-86509-320-5 SN - 0938-5533 VL - 270 SP - 1 EP - 107 PB - Wirtschaftsverlag NW CY - Bremerhaven AN - OPUS4-181 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Bayerl, C. A1 - Shahryari, M. A1 - Reiter, R. A1 - Proß, V. A1 - Lehmann, K. A1 - Kühl, A. A. A1 - Becker, Dorit A1 - Schulz, Andreas A1 - Infante Duarte, C. A1 - Taupitz, M. A1 - Geisel, D. A1 - Tzschätzsch, H. A1 - Saatz, Jessica A1 - Traub, Heike A1 - Asbach, P. T1 - Quantitative Analysis of Gadolinium Deposits in Liver Tissue of Patients After Single or Multiple Gadolinium-based Contrast Agent Application N2 - Gadolinium-based contrast agents (GBCAs) are widely used in magnetic resonance imaging. Concerns exist regarding gadolinium deposition and its potential histopathologic tissue alterations, especially after repeated administrations of linear, less stable GBCAs. This study aimed to quantify gadolinium mass fractions in liver specimens of subjects exposed to GBCAs in correlation with histopathologic features. In this study, mass fractions of gadolinium in human liver specimens from 25 subjects who underwent liver tumor resection surgery and had received GBCA (1 to 9 times over 4 years), were quantitatively analyzed using inductively coupled plasma–mass spectrometry (ICP-MS). Histomorphology was assessed based on the nonalcoholic fatty liver disease activity score (NAS). Our results suggest that after intravenous administration of GBCA, a small fraction of gadolinium is retained in the liver over a time period of at least several weeks. A relationship was observed between Gadolinium retention and the number of GBCA administrations, but not with the cumulative dose and the degree of fatty liver disease. KW - ICP-MS KW - Contrast agent KW - Gadolinium KW - Liver PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-646608 DO - https://doi.org/10.1097/RLI.0000000000001254 SN - 1536-0210 SP - 1 EP - 10 PB - Lippincott Williams & Wilkins CY - Philadelphia, Pa. AN - OPUS4-64660 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Becker, Roland A1 - Koch, Matthias A1 - Wachholz, Sigrid A1 - Win, Tin T1 - Quantification of total petrol hydrocarbons (TPH) in soil by IR-spectrometry and gas chromatography - conclusions from three proficiency testing rounds N2 - Due to the utilisation of 1,1,2-trichlorotrifluoroethane (CFE) as extraction solvent the IR-spectrometric determination of total petrol hydrocarbon (TPH) in soil according to ISO/TR 11046 has been replaced by gas chromatography/flame ionisation detection (GC/FID) after extraction with a halogen-free solvent according to ISO/DIS 16703:2001. The results obtained with both methods by field laboratories in three proficiency testing (PT) rounds are compared. The consensus means obtained with GC/FID are typically 10%-20% (ranging between 0% and 25%) higher than those found with IR-spectroscopy. On the contrary, coefficients of variation (CV) are roughly double in case of GC/FID and are briefly discussed against the background of the Horwitz equation. KW - Hydrocarbons KW - Soil KW - IR spectrometry KW - Gas chromatography KW - Interlaboratory comparison PY - 2002 DO - https://doi.org/10.1007/s00769-002-0476-9 SN - 0949-1775 SN - 1432-0517 VL - 7 IS - 7 SP - 286 EP - 289 PB - Springer CY - Berlin AN - OPUS4-1627 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Becker, Roland T1 - The role of matrix reference materials in the process of method validation - A case study: PCBs in cable coverings T2 - BERM 9 - 9th International Symposium on Biological and Environmental Reference Materials CY - Berlin, Germany DA - 2003-06-15 PY - 2003 AN - OPUS4-4793 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Traub, Heike A1 - Win, Tin A1 - Lück, Detlef A1 - Koch, Matthias A1 - Becker, Roland T1 - Evaluation and Development of Methods for the Analysis of Soils according to § 8 of the German Federal Soil Protection Act T2 - 7th International FZK/TNO Conference on Contaminated Soil ; 7th ConSoil 2000 CY - Leipzig, Germany DA - 2000-09-18 KW - Soil KW - Heavy metals KW - Cyanide KW - Chromium KW - Organic contaminants KW - Analytical methods KW - Standardization KW - National law PY - 2000 SN - 0-7277-2954-3 VL - 2 SP - 904 EP - 905 PB - Telford CY - London AN - OPUS4-876 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Würth, Christian A1 - Manley, P. A1 - Voigt, R. A1 - Ahiboz, D. A1 - Becker, C. A1 - Resch-Genger, Ute T1 - Metasurface Enhanced Sensitized Photon Upconversion: Toward Highly Efficient Low Power Upconversion Applications and Nanoscale E-Field Sensors N2 - Large-scale nanoimprinted metasurfaces based on silicon photonic crystal slabs were produced and coated with a NaYF4:Yb3+/Er3+ upconversion nanoparticle (UCNP) layer. UCNPs on these metasurfaces yield a more than 500-fold enhanced upconversion emission compared to UCNPs on planar surfaces. It is also demonstrated how the optical response of the UCNPs can be used to estimate the local field energy in the coating layer. Optical simulations using the finite element method validate the experimental results and the calculated spatial three-dimensional field Energy distribution helps us to understand the emission enhancement mechanism of the UCNPs closely attached to the metasurface. In addition, we analyzed the spectral shifts of the resonances for uncoated and coated metasurfaces and metasurfaces submerged in water to enable a prediction of the optimum layer thicknesses for different excitation wavelengths, paving the way to applications such as electromagnetic field sensors or bioassays. KW - Nanoparticles KW - Upconversion KW - Metasurface KW - Field sensor KW - Emission enhancement KW - Photonic crystal PY - 2020 DO - https://doi.org/10.1021/acs.nanolett.0c02548 VL - 20 IS - 9 SP - 6682 EP - 6689 PB - ACS Publications AN - OPUS4-51427 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Koch, Matthias A1 - Buge, Hans-Gerhard A1 - Becker, Roland A1 - Nehls, Irene T1 - Kalibrierstandard für die Mineralöl (MKW)-analytik mittels GC-FID KW - Kalibrierstand KW - Referenzmaterial KW - MKW KW - GC PY - 2005 SN - 0016-3538 VL - 49 IS - 11 SP - 207 PB - GIT-Verlag CY - Darmstadt AN - OPUS4-11601 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CHAP A1 - Becker, S. A1 - Lu, Z. A1 - Leinitz, Sarah A1 - Schmidt, Wolfram A1 - Stephan, D. A1 - von Klitzing, R. ED - Mechtcherine, V. ED - Khayat, K. ED - Secrieru, E. T1 - Particle Interactions in Silica Systems in Presence of Superplasticizer N2 - The flowability of cement paste is of great importance in today’s construction industry and is influenced by additives such as superplasticizers (SP). One type of SPs are polycarboxylate ether type SPs. These additives electrostatically bind with the negatively charged carboxylic groups at the backbone to the positively charged clinker phases. To model positively charged clinker phases with adsorbed SP, silicon Wafers are pre-coated with cationic polyethylenimine (PEI) and SP is adsorbed onto the coated surface (Si/PEI/SP). Two different polycarboxylate ether type (PCE) SP are compared – one for ready-mix concrete and one for precast concrete. In this preliminary study the interaction forces between Si/PEI/SP surface and a silica microsphere (colloidal probe) are investigated under mild physico-chemical conditions (pH *6, ion concentration <10−5 M) using Colloidal Probe Atomic Force Microscopy (CP-AFM). The interaction force between the model surfaces is attractive for low concentration of SP. The force changes from attractive to repulsive by increasing amount of SP. The force upon approach reveals a biexponential behavior. The exponential decay at large and short surface separations are attributed to electrostatic and steric interactions, respectively. The steric forces of the SP for ready-mix concrete show a steeper onset than the SP for precast concrete. The quantification of these interaction forces will be compared to rheological measurements of similar systems. Furthermore, the parameters will be changed to better approach the conditions in real systems, i.e. higher pH and ionic strength. This helps to understand how the forces on the nanoscale influence the macroscopic rheology. KW - Interfacial forces KW - Silica beads KW - Superplasticizer KW - AFM PY - 2019 SN - 978-3-030-22565-0 DO - https://doi.org/10.1007/978-3-030-22566-7 SN - 2211-0844 VL - 23 SP - 571 EP - 579 PB - Springer ET - 1 AN - OPUS4-49183 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Ji, Y. A1 - Becker, S. A1 - Lu, Z. A1 - Mezhov, Alexander A1 - von Klitzing, R. A1 - Schmidt, Wolfram A1 - Stephan, D. T1 - Effect of resting time on rheological properties of glass bead suspensions - Depletion and bridging force among particles N2 - The effect of resting time on the rheological properties of cement suspensions is generally explained by early formed structure and overconsumption of polycarboxylate superplasticizers (PCEs). In this paper, we propose that the influence of resting time on the rheological properties is closely related to size variation of non-absorbed PCE. To identify this, glass bead suspensions were prepared with various amounts of PCE and ionic solution, and their rheological properties were evaluated at various times. We found that the yield stress increases with time at higher PCE concentrations and higher ionic strength solutions. Adsorbed PCE during resting tends to bridge the particles rather than disperse them. In addition, it was found that hydrodynamic radius of PCE increased with resting time, and depletion forces resulting from non-absorbed PCE size changes correlate well with the increased yield stress. KW - Depletion force KW - Ionic stregth KW - PCE KW - Rheology KW - Resting time PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-587193 DO - https://doi.org/10.1111/jace.19469 SN - 0002-7820 SN - 1551-2916 VL - 107 IS - 1 SP - 624 EP - 639 PB - Wiley-Blackwell CY - Oxford AN - OPUS4-58719 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Piechotta, Christian A1 - Iznaguen, Hassan A1 - Traub, Heike A1 - Feldmann, Ines A1 - Köppen, Robert A1 - Witt, Angelika A1 - Jung, Christian A1 - Becker, Roland A1 - Oleszak, Katrin A1 - Bücker, Michael A1 - Urban, Klaus A1 - Reger, Christian A1 - Ostermann, Markus T1 - Bewitterungsszenarien im Vergleich – Veränderungen in der Oberflächenmorphologie von Polypropylen (PP) und Polystyrol (PS) unter dem Aspekt des Austrags von polybromierten Flammschutzmitteln N2 - Gegenstand der vorzustellenden Arbeiten ist die Prüfung der Umwelt-beständigkeit und -verträglichkeit von Materialien und Produkten hinsichtlich der Emission von potenziellen Schadstoffen in die Umwelt. Hierzu werden chemisch-physikalische Einflüsse (Bewitterung) und mikrobielle Beanspruchungen an Modellmaterialien evaluiert. So werden die Freisetzungsraten von Schadstoffen in Abhängigkeit der Beanspruchung beschrieben. Als Modellmaterialien kommen die Polymere Polystyrol (PS) und Polypropylen (PP) zum Einsatz. Synergistische Effekte der Bewitterungsparameter und der mikrobiologischen Beanspruchung sollen dabei ebenso betrachtet werden, wie die gezielte Alterung. Auch findet eine Beschreibung des Verhaltens der ausgetragenen Schadstoffe in den Umweltkompartimenten Boden oder Wasser statt. Hier sind mit Hilfe der zu entwickelnden Screening- und non-Target-Analyseverfahren die Transformation und der Metabolismus durch Mikroorganismen zu beschreiben. Aus den Ergebnissen sollen Korrelationen zwischen den künstlichen Alterungsverfahren und realen Szenarien abgeleitet werden. T2 - 47. Jahrestagung der GUS CY - Blankenloch-Stutensee, Germany DA - 21.03.2018 KW - Schadstoffaustrag KW - Umweltsimulation KW - Bewitterung PY - 2018 SN - 978-981-18507-2-7 VL - 47 SP - 115 EP - 128 AN - OPUS4-49802 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - RPRT A1 - Dorgerloh, Ute A1 - Becker, Roland A1 - Sauer, Andreas T1 - Report on the interlaboratory validation trial of DIN 38407-53 N2 - DIN 38407-53 "German standard methods for the examination of water, waste water and sludge — Jointly determinable substances (group F) — Part 53: Determination of TFA in water — Method using liquid chromatography and mass spectrometric detection (LC-MS/MS) after direct injection (F 53)" was prepared by working group NA 119 01 03 02 16 AK "LC-MS/MS-Verfahren" of the Technical Committee NA 119 01 03 AA "Wasseruntersuchung" in the DIN-Normenausschuss Wasserwesen (NAW). The DIN 38407-53 was technically finalized as Draft on 2024-02, further versions have been editorially revised only. The interlaboratory validation trial was carried out according to the rules set by ISO 7013. They allowed adopting validation data from a working group internal ring test if they are scientifically accepted and fulfil the requirements of ISO 7013. Twelve German and Swiss participants declared to have strictly followed the instructions given in draft DIN 38407-53. The intercomparison was organised and operated by the Federal Institute for Materials Research and Testing BAM in 2024. The performance characteristics for the quantification of TFA were evaluated in different water types and evaluated according to ISO 5725-2. KW - TFA Trifluoroacetic acid KW - Water analysis KW - LC MSMS PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-615066 DO - https://doi.org/10.26272/opus4-61506 SP - 1 EP - 18 PB - Bundesanstalt für Materialforschung und -prüfung (BAM) CY - Berlin AN - OPUS4-61506 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kindrachuk, Vitaliy A1 - Fedelich, Bernard A1 - Becker, M. ED - Beck, T. ED - Charkaluk, E. T1 - Constitutive modelling of viscoplastic deformation in single crystal nickel-basis superalloys subjected to cyclic and creep loadings at high-temperatures N2 - Gas turbines are widely used for a variety of purposes including power generation, compression or as jet engines in aircrafts. The critical components of a gas turbine are the high-pressure turbine blades which operate under severe conditions. These include thermo-mechanical loadings over temperatures ranging from room temperature up to 1100°C. While a large number of constitutive models for single crystals have been proposed, most applications are restricted to special loading scenarios, temperature range and deformation mechanisms. In particular, a number of models are focused on pure creep. Only a few papers consider application of both creep and fatigue. Applications of the constitutive models to long-term stress relaxation are even scarcer. The new model assumes deformation-induced softening and can properly reproduce the viscous behavior at different time scales. The model has been calibrated with the uniaxial tests at 800°C and 950°C in [001], [011] and [111] specimens of a nickel-basis superalloy. The predicted creep, short- and long-term relaxation and cyclic tests are in reasonable agreement with the experimental observations. T2 - Eighth International Conference on Low Cycle Fatigue (LCF8) CY - Dresden, Germany DA - 27.06.2017 KW - Constitutive law KW - Single crystal KW - Superalloy KW - Creep KW - Low cycle fatigue PY - 2017 SP - 371 EP - 376 PB - DVM e.V. CY - Berlin AN - OPUS4-40928 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Sanchez-Martin, Pedro A1 - Becker, Roland A1 - Toepel, J. A1 - Gorbushina, Anna T1 - An improved test for the evaluation of hydrocarbon degradation capacities of diesel-contaminating microorganisms N2 - The development of a test to evaluate the degradation of semi-volatile fuels as diesel by microorganisms is presented. This method is based on the principles described in the CEC-L-103 Standard procedure that is exclusively meant for testing the biodegradability of non-volatile lubricants. Therefore, significant modifications involve aseptic conditions for testing specific microorganisms and conducting the test in closed vessels avoiding evaporation losses, while fuel quantification using gas chromatography-flame ionization detection (GC-FID) is retained. It is suggested that the modified procedure should enable routine application for semi-volatile hydrocarbon-based fuels. GC-FID provides additionally valuable information on the alteration of fuel component patterns during biodegradation. The procedure was successfully tested using two bacteria (Pseudomonas aeruginosa and Sphingomonas sp.) and two yeasts (Moesziomyces sp. and Candida sp.) isolated from real diesel contamination cases. All tested microorganisms caused a significant degradation of diesel fuel achieving hydrocarbon degradation percentages ranging from 23% to 35%. Specific aspects on the test modification and prospects for further modification regarding targeted investigations in the field of fuel contamination by microorganisms are briefly discussed. KW - Biofouling KW - Bacteria KW - Fungi KW - CEC-L-103 KW - GC-FID KW - Reference organisms PY - 2018 DO - https://doi.org/10.1016/j.ibiod.2018.01.009 SN - 0964-8305 VL - 129 SP - 89 EP - 94 PB - Elsevier AN - OPUS4-44524 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Ahmed, A. A. A. A1 - Alegret, N. A1 - Almeida, B. A1 - Alvarez-Puebla, R. A1 - Andrews, A. M. A1 - Ballerini, L. A1 - Barrios-Capuchino, J. J. A1 - Becker, C. A1 - Blick, R. H. A1 - Bonakdar, S. A1 - Chakraborty, I. A1 - Chen, X. A1 - Cheon, J. A1 - Chilla, G. A1 - Conceicao, A. L. C. A1 - Delehanty, J. A1 - Dulle, M. A1 - Efros, A. L. A1 - Epple, M. A1 - Fedyk, M. A1 - Feliu, N. A1 - Feng, M. A1 - Fernandez-Chacon, R. A1 - Fernandez-Cuesta, I. A1 - Fertig, N. A1 - Förster, S. A1 - Garrido, J. A. A1 - George, M. A1 - Guse, A. H. A1 - Hampp, N. A1 - Harberts, J. A1 - Han, J. A1 - Heekeren, H. R. A1 - Hofmann, U. G. A1 - Holzapfel, M. A1 - Hosseinkazemi, H. A1 - Huang, Y. A1 - Huber, P. A1 - Hyeon, T. A1 - Ingebrandt, S. A1 - Ienca, M. A1 - Iske, A. A1 - Kang, Y. A1 - Kasieczka, G. A1 - Kim, D.-H. A1 - Kostarelos, K. A1 - Lee, J.-H. A1 - Lin, K.-W. A1 - Liu, S. A1 - Liu, X. A1 - Liu, Y. A1 - Lohr, C. A1 - Mailänder, V. A1 - Maffongelli, L. A1 - Megahed, S. A1 - Mews, A. A1 - Mutas, M. A1 - Nack, L. A1 - Nakatsuka, N. A1 - Oertner, T. G. A1 - Offenhäusser, A. A1 - Oheim, M. A1 - Otange, B. A1 - Otto, F. A1 - Patrono, E. A1 - Peng, B. A1 - Picchiotti, A. A1 - Pierini, F. A1 - Pötter-Nerger, M. A1 - Pozzi, M. A1 - Pralle, A. A1 - Prato, M. A1 - Qi, B. A1 - Ramos-Cabrer, P. A1 - Resch-Genger, Ute A1 - Ritter, N. A1 - Rittner, M. A1 - Roy, S. A1 - Santoro, F. A1 - Schuck, N. W. A1 - Schulz, F. A1 - Seker, E. A1 - Skiba, M. A1 - Sosniok, M. A1 - Stephan, H. A1 - Wang, R. A1 - Wang, T. A1 - Wegner, Karl David A1 - Weiss, P. S. A1 - Xu, M. A1 - Yang, C. A1 - Zargarin, S. S. A1 - Zeng, Y. A1 - Zhou, Y. A1 - Zhu, D. A1 - Zierold, R. A1 - Parak, W. J. T1 - Interfacing with the Brain: How Nanotechnology Can Contribute N2 - Interfacing artificial devices with the human brain is the central goal of neurotechnology. Yet, our imaginations are often limited by currently available paradigms and technologies. Suggestions for brain−machine interfaces have changed over time, along with the available technology. Mechanical levers and cable winches were used to move parts of the brain during the mechanical age. Sophisticated electronic wiring and remote control have arisen during the electronic age, ultimately leading to plug-and-play computer interfaces. Nonetheless, our brains are so complex that these visions, until recently, largely remained unreachable dreams. The general problem, thus far, is that most of our technology is mechanically and/or electrically engineered, whereas the brain is a living, dynamic entity. As a result, these worlds are difficult to interface with one another. Nanotechnology, which encompasses engineered solid-state objects and integrated circuits, excels at small length scales of single to a few hundred nanometers and, thus, matches the sizes of biomolecules, biomolecular assemblies, and parts of cells. Consequently, we envision nanomaterials and nanotools as opportunities to interface with the brain in alternative ways. Here, we review the existing literature on the use of nanotechnology in brain−machine interfaces and look forward in discussing perspectives and limitations based on the authors’ expertise across a range of complementary disciplines from neuroscience, engineering, physics, and chemistry to biology and medicine, computer science and mathematics, and social science and jurisprudence. We focus on nanotechnology but also include information from related fields when useful and complementary. KW - Nanoneuro interface KW - Brain-on-a-chip KW - Nanostructured interface KW - Electrode arrays KW - Neuro-implants KW - Advanced nanomaterials KW - Quality assurance PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-634893 DO - https://doi.org/10.1021/acsnano.4c10525 SN - 1936-086X VL - 19 IS - 11 SP - 10630 EP - 10717 PB - ACS Publications AN - OPUS4-63489 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CHAP A1 - Leinitz, Sarah A1 - Lu, Z. A1 - Becker, S. A1 - Stephan, D. A1 - von Klitzing, R. A1 - Schmidt, Wolfram ED - Mechtcherine, V. ED - Khayat, K. ED - Secrieru, E. T1 - Influence of different accelerators on the rheology and early hydration of cement paste N2 - Special applications like pumping, spraying or printing of concrete require the precise adjustment of very specific rheological properties at different time steps during the casting process. Superplasticizers such as polycarboxylate ethers (PCE) can be used to obtain the required flowability, which, possibly in combination with additional rheology modifying admixtures, generate the required specified consistency. However, after the application, the concrete should change the rheological properties immediately in order to avoid deformations at rest. Therefore, the use of accelerators can be effective. Accelerators influence the hydration of cementitious materials, and thus the rheological properties over the course of time and the setting. In this paper, the influence of different accelerators on the rheology and early hydration of cement paste as well as the interaction of accelerator and PCE are presented. Methods like rheometry, needle penetration tests and practical Tests like spread flow were applied. The used accelerators showed accelerating behavior on the cement pastes without and in the presence of PCE. At the same time an influence on the rheology could be observed. This effect was less in the mixes with PCE, especially at the highest water/cement ratio (w/c). KW - Rheology KW - Cement paste KW - Accelerator KW - Superplasticizer KW - Setting PY - 2019 SN - 978-3-030-22565-0 DO - https://doi.org/10.1007/978-3-030-22566-7 SN - 2211-0844 VL - 23 SP - 106 EP - 115 PB - Springer ET - 1 AN - OPUS4-49139 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CHAP A1 - Lu, Z. A1 - Becker, S. A1 - Leinitz, Sarah A1 - von Klitzing, R. A1 - Schmidt, Wolfram A1 - Stephan, D. ED - Mechtcherine, V. ED - Khayat, K. ED - Secrieru, E. T1 - Rheological properties of silica beads in the presence of different polymers and electrolyte N2 - Properties of interstitial liquid phase in cement paste, including the species and concentrations of polymers and ion etc., play an important role for the rheological properties of cementitious materials. In order to better understand their effect, an inert model substance, spherical silica beads (SBs) with defined surface and granulometry were used in the presence of electrolytes (CaCl2) and/or different polymers, including polycarboxylate superplasticizer (PCE) and polyethylene glycol (PEG). It was found the presence of Ca2+ greatly increases the viscosity and yield stress of silica beads paste (SBP), which is proportional to the [Ca2+]. For the effect of PCE, the addition of PCE is beneficial to the flowability of SBP, but a high dosage of PCE leads to a reversal effect. Furthermore, the yield stress firstly increases and then decreases with increasing [Ca2+] under the same dosage of PCE. The addition of PEG always increases the yield stress of SBP, regardless of the ion concentration and the presence or not of PCE. KW - Rheological properties KW - Ions KW - Superplasticizer KW - Silica beads PY - 2019 SN - 978-3-030-22565-0 SN - 978-3-030-22566-7 DO - https://doi.org/10.1007/978-3-030-22566-7_72 SN - 2211-0844 VL - 23 SP - 619 EP - 627 PB - Springer ET - 1 AN - OPUS4-49185 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Lu, Z. A1 - Becker, S. A1 - Leinitz, Sarah A1 - Schmidt, Wolfram A1 - von Klitzing, R. A1 - Stephan, D. T1 - Interaction of Different Charged Polymers with Potassium Ions and Their Effect on the Yield Stress of Highly Concentrated Glass Bead Suspensions N2 - The interaction of different charged polymers, namely anionic polycarboxylate superplasticizer (PCE) and neutral polyethylene glycol (PEG) with potassium ions, and their effect on the yield stress of highly concentrated glass bead suspension (GBS), were studied under different concentrations of potassium ions ([K+]). It was found that, compared to the neutral PEG, the negatively charged PCE can be adsorbed on glass beads (GB), and then decreases the yield stress of GBS. The increasing concentration of free polymer in the interstitial liquid phase with the increased polymer dosage leads to the higher yield stress of GBS, which may be caused by the higher Depletion force. In addition, this effect is also related to the charge density of the polymer and the [K+] in the solution. Along with the increase in [K+], the yield stress of GBS increases significantly with the addition of PCE, but this cannot be observed with PEG, which indicates that potassium ions can interact with negatively charged PCE instead of the neutral PEG. At last, the interparticle Forces between two single GB with adsorbed PCE in solutions containing [K+] and PCE were measured by colloidal probe atomic force microscopy to better understand the interaction of the charged polymer with counterions. KW - Yield stress KW - Free polymer KW - Charge density KW - Depletion force KW - Potassium ions PY - 2020 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-506015 DO - https://doi.org/10.3390/ma13071490 SN - 1996-1944 VL - 13 IS - 7 SP - 1490, 1 EP - 1490, 16 PB - MDPI AN - OPUS4-50601 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Redda, Zinnabu Tassew A1 - Prinz, Carsten A1 - Yimam, Abubeker A1 - Barz, Mirko A1 - Becker, Katharina A1 - Gizaw, Desta Getachew A1 - Laß-Seyoum, Asnakech T1 - Structural and textural characterization of Brassica carinata biochar to investigate its potential industrial applications N2 - Biochar, a low-cost, and carbon-rich product of the thermal decomposition of biomass under oxygen-limited conditions and at relatively low temperatures, has recently been identified as a promising porous material with a wide range of industrial applications. In the present study, a comprehensive analysis of proximate, ultimate, nutrient profile, structural, and textural properties of a biochar derived from two Ethiopian indigenous Brassica carinata cultivars was conducted. The characterization of the biochar was achieved by employing a variety of well-established methods, including proximate analysis (moisture, volatile matter, ash content, and fixed carbon), ultimate analysis (C, S, and O content), atomic oxygen to carbon ratio (O/C), morphological and elemental composition analysis through scanning electron microscopy coupled with energy-dispersive X-ray spectroscopy (SEM-EDS). Furthermore, a combination of mercury intrusion porosimetry (MIP), dynamic vapor sorption (DVS), and gas adsorption methods such as nitrogen and krypton gas adsorption, were used for an in-depth study of the porous structure. SEM morphological characterization showed that the biochar surfaces showed multiple pores of diverse sizes and shapes. EDS elemental composition analysis revealed that sodium, aluminium, and silicon were not detected, but potassium, calcium, magnesium, and iron were all present in noticeable amounts. Furthermore, ultimate analysis showed that the most prevalent elements were carbon (86 wt.%) and oxygen (10.41‒9.77 wt.%), while sulphur was present in negligible concentrations. MIP analysis demonstrated that the porosities of the biochars varied from 62.68 to 69.99 wt.%, with the Holetta-1 biochar showing the highest porosity. The superior porosity of Holetta-1, as confirmed via MIP analysis, yielded higher values for bulk volume (2.36 mL g− 1), skeletal volume (1.65 mL g− 1), and total intrusion volume (1.65 mL g− 1) compared to the Yellow Dodolla. The most frequent pore diameters were 172.46 μm for Yellow Dodolla and 111.42 μm for Holetta-1. The MIP log differential pore diameter distributions were observed to vary from 18 to 411 μm and 10 to 411 μm, respectively, for Yellow Dodolla and Holetta-1. Despite the biochars’ low specific surface areas (0.17–0.21 m² g⁻¹), krypton sorption was a suitable technique for its characterization compared to DVS and nitrogen sorption methods. In conclusion, the characterization studies confirmed that this carbon-rich porous material possesses unique and valuable properties, with these attributes position it as a promising alternative for diverse industrial applications, contributing to the development of a bio-based circular economy. KW - Morphological characterization KW - Mercury intrusion porosimetry KW - Gas adsorption PY - 2026 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-655325 DO - https://doi.org/10.1038/s41598-025-32063-1 SN - 2045-2322 VL - 16 IS - 1 SP - 1 EP - 19 PB - Springer Science and Business Media LLC AN - OPUS4-65532 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Lisec, Jan A1 - Recknagel, Sebastian A1 - Prinz, Carsten A1 - Vogel, Kristin A1 - Koch, Matthias A1 - Becker, Roland T1 - eCerto—versatile software for interlaboratory data evaluation and documentation during reference material production N2 - The statistical tool eCerto was developed for the evaluation of measurement data to assign property values and associated uncertainties of reference materials. The analysis is based on collaborative studies of expert laboratories and was implemented using the R software environment. Emphasis was put on comparability of eCerto with SoftCRM, a statistical tool based on the certification strategy of the former Community Bureau of Reference. Additionally, special attention was directed towards easy usability from data collection through processing, archiving, and reporting. While the effects of outlier removal can be flexibly explored, eCerto always retains the original data set and any manipulation such as outlier removal is (graphically and tabularly) documented adequately in the report. As a major reference materials producer, the Bundesanstalt für Materialforschung und -prüfung (BAM) developed and will maintain a tool to meet the needs of modern data processing, documentation requirements, and emerging fields of RM activity. The main features of eCerto are discussed using previously certified reference materials. KW - Reference material KW - Statistics KW - Software KW - Collaborative trial PY - 2023 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-591851 DO - https://doi.org/10.1007/s00216-023-05099-3 SP - 1 EP - 9 PB - Springer Science and Business Media LLC AN - OPUS4-59185 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Gerrits, Ruben A1 - Stepec, Biwen An A1 - Bäßler, Ralph A1 - Becker, Roland A1 - Dimper, Matthias A1 - Feldmann, Ines A1 - Goff, Kira L. A1 - Günster, Jens A1 - Hofmann, Andrea A1 - Hesse, René A1 - Kirstein, Sarah A1 - Klein, Ulrich A1 - Mauch, Tatjana A1 - Neumann-Schaal, Meina A1 - Özcan Sandikcioglu, Özlem A1 - Taylor, Nicole M. A1 - Schumacher, Julia A1 - Shen, Yin A1 - Strehlau, Heike A1 - Weise, Matthias A1 - Wolf, Jacqueline A1 - Yurkov, Andrey A1 - Gieg, Lisa M. A1 - Gorbushina, Anna T1 - A 30-year-old diesel tank: Fungal-dominated biofilms cause local corrosion of galvanised steel N2 - The increased use of biodiesel is expected to lead to more microbial corrosion, fouling and fuel degradation issues. In this context, we have analysed the metal, fuel and microbiology of a fouled diesel tank which had been in service for over 30 years. The fuel itself, a B7 biodiesel blend, was not degraded, and—although no free water phase was visible—contained a water content of ~60 ppm. The microbial community was dominated by the fungus Amorphotheca resinae, which formed thick, patchy biofilms on the tank bottom and walls. The tank sheets, composed of galvanised carbon steel, were locally corroded underneath the biofilms, up to a depth of a third of the sheet thickness. On the biofilm-free surfaces, Zn coatings could still be observed. Taken together, A. resinae was shown to thrive in these water-poor conditions, likely enhancing corrosion through the removal of the protective Zn coatings. KW - Fungal biofilms KW - Biodiesel degradation mechanisms PY - 2026 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-655014 DO - https://doi.org/10.1038/s41529-025-00731-2 SN - 2397-2106 VL - 10 IS - 1 SP - 1 EP - 14 PB - Springer Science and Business Media LLC AN - OPUS4-65501 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Sichler, Theresa Constanze A1 - Adam, Christian A1 - Becker, Roland A1 - Sauer, Andreas A1 - Ostermann, Markus A1 - Barjenbruch, M. T1 - Phosphorus determination in sewage sludge: comparison of different aqua regia digestion methods and ICP-OES, ICP-MS and photometric determination N2 - Phosphorus recycling from sewage sludge will be obligatory in Germany from 2029. Phosphorus content determination in sewage sludge is crucial to assess the prescribed recycling rates. Currently, German law regards sample preparation using aqua regia digestion in a microwave or under reflux conditions as well as instrumental phosphorus determination by ICP-OES, ICP-MS, or photometric determination with ammonium molybdate as equivalent. However, it is questionable whether these methods are indeed equivalent regarding phosphorus quantification in sludges near the limit of 20 g/kg for mandatory recycling. To answer this question, 15 sewage sludges of 11 different wastewater treatment plants were investigated with all permitted method (digestion and measurement) combinations. Moreover, one sewage sludge was also examined in an interlaboratory comparison (ILC) with 28 participants. This study shows that the above-mentioned methods differ in some cases significantly but across all method combinations and sludges, phosphorus recovery was between 80 and 121% after normalization to the grand mean (average of 15 sludges between 85 and 111%). The ILC and the examination of 15 sludges produced largely similar results. There is a tendency to higher phosphorus recovery after microwave digestion compared to reflux digestion and ICP-OES measurements determine higher phosphorus contents than ICP-MS and photometric phosphorus determination. As a result, the authors recommend ICP-OES determination of phosphorus in sewage sludge after microwave digestion. KW - Sewage sludge KW - ICP-OES KW - Phosphous recovery KW - ICP-MS KW - Photometric P determination KW - Interlaboratory comparison PY - 2022 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-558869 DO - https://doi.org/10.1186/s12302-022-00677-1 VL - 34 IS - 99 SP - 1 EP - 14 PB - Springer AN - OPUS4-55886 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Abad Andrade, Carlos Enrique A1 - Florek, S. A1 - Becker-Ross, H. A1 - Huang, M.-D. A1 - Lopez-Linares, F. A1 - Poirier, L. A1 - Jakubowski, Norbert A1 - Recknagel, Sebastian A1 - Panne, Ulrich T1 - Shake, shut, and go – A fast screening of sulfur in heavy crude oils by highresolution continuum source graphite furnace molecular absorption spectrometry via GeS molecule detection N2 - A fast and simple method for sulfur quantification in crude oils was developed by using high-resolution continuum source graphite furnace molecular absorption spectrometry (HR-CS-GFMAS). For this, heavy crude oil samples were prepared as microemulsion (shake) and injected into a graphite furnace (shut). Finally, the concentration of sulfur was determined by monitoring in situ the transient molecular spectrum of GeS at wavelength 295.205nm after adding a germanium solution as molecular forming agent (and go). Zirconium dioxide in the form of nanoparticles (45–55nm) was employed as a permanent modifier of the graphite furnace. Calibration was done with an aqueous solution standard of ammonium sulfate, and a characteristic mass (m0) of 7.5ng was achieved. The effectiveness of the proposed method was evaluated analizing, ten heavy crude oil samples with Sulfur amounts ranging between 0.3 and 4.5% as well as two NIST standard reference materials, 1620c and 1622e. Results were compared with those obtained by routine ICP-OES analysis, and no statistical relevant differences were found. KW - Heavy crude oil KW - Sulfur KW - HR-CS-MAS KW - Germanium sulfide KW - Microemulsion PY - 2019 DO - https://doi.org/10.1016/j.sab.2019.105671 SN - 0584-8547 VL - 160 SP - 105671 PB - Elsevier B.V. CY - Amsterdam, Netherlands AN - OPUS4-48747 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Becker, Roland T1 - Hinweis auf den Abbau von FCKW in kontaminiertem Grundwasser bis zur Difluoressigsäure (DFA) N2 - Ein Vergleich der Gehalte von Difluoressigsäure (DFA) und Trifluoressigsäure (TFA) in Regen- und Oberflächenwässern im Berliner Raum ergab ein TFA/DFA Verhältnis in Regenwasser von 10:1. Im Gegensatz dazu wies Grundwasser aus dem Einzugsbereich einer historischen Kontamination durch Fluorchlorkohlenwasserstoffe (FCKW) ein TFA/DFA-Verhältnis von 1:3 auf. Dies und die ungewöhnlich hohe DFA-Konzentration an dieser Stelle wird vor dem Hintergrund der beobachteten mikrobiellen Abbauprodukte des ursprünglichen eingetragenen FCKW 1,1,2-Trichlor-1,2,2-trifluorethan (R113) diskutiert. Eine mikrobielle Umwandlung des bekannten Abbauproduktes Chlortrifluorethylen (R1113) zur DFA wurde bislang nicht in Umweltkompartimenten beobachtet und wird hier auf Basis bekannter Stoffwechselwege vorgeschlagen. TFA wurde in Regenwasser, Oberflächenwasser und Grundwasser in vergleichbaren Größenordnungen von ca. 500 ng/L bestimmt. Im Gegensatz dazu wurde DFA in Grundwasserproben im Bereich der Schadstoffquelle der FCKW-Kontamination mit bis zu 2.000 ng/L nachgewiesen. Die Summe von TFA und DFA im Grundwasser korreliert nicht mit dem Eintrag aus Niederschlag und Oberflächenwasser. Darum liegt die Vermutung nahe, dass es für DFA andere Quellen als den direkten Eintrag oder den möglichen Abbauweg über TFA geben muss. DFA ist vermutlich ein Abbauprodukt von R1113. FCKWs, die im ersten Abbauschritt zu 1,1-Difluorethenen metabolisieren, stehen im Verdacht, in der Folge zu DFA zu hydrolysieren. Entscheidend scheint, dass bereits im Ausgangsprodukt ein CF2-Strukturelement enthalten ist, das dann zur Bildung von DFA führen kann. Somit würde aus dem ursprünglichen Eintrag des Kältemittels R113 über schrittweise Dechlorierung via 1,2-Dichlor-1,2,2-Trifluorethan (R123a) und R1113 die Bildung des beobachteten DFA folgen. Es ist also sinnvoll, DFA in die Diskussion zur Regulierung der Endprodukte des Abbaus fluorhaltiger Kälte- oder Lösungsmittel einzubeziehen. Die Ergebnisse wurden im Normausschuss Wasserwesen (NAW) des DIN vorgestellt und es soll ein Arbeitskreis gegründet werden, der ein Normverfahren zur Quantifizierung von TFA und DFA in Wasser erarbeitet. Interessierte Laboratorien sind herzlich eingeladen, die Normungsarbeit zu unterstützen. T2 - DEHEMA 21. Symposium Strategien zur Sanierung von Boden & Grundwasser 2019 CY - Frankfurt a.M., Germany DA - 25.11.2019 KW - Trifluoressigsäure KW - Difluoressigsäure KW - Grundwasser KW - Fluorchlorkohlenwasserstoffe PY - 2019 AN - OPUS4-49452 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Essmann, M. A1 - Becker, S. F. A1 - Witt, Julia A1 - Zhan, J. A1 - Chimeh, A. A1 - Korte, A. A1 - Zhong, J. A1 - Vogelgesang, R. A1 - Wittstock, G. A1 - Lienau, C. T1 - Vectorial near-field coupling N2 - The coherent exchange of optical near fields between two neighbouring dipoles plays an essential role in the optical properties, quantum dynamics and thus the function of many naturally occurring and artificial nanosystems. These interactions are challenging to quantify experimentally. They extend over only a few nanometres and depend sensitively on the detuning, dephasing and relative orientation (that is, the vectorial properties) of the coupled dipoles. Here, we introduce plasmonic nanofocusing spectroscopy to record coherent light scattering spectra with 5 nm spatial resolution from the apex of a conical gold nanotaper. The apex is excited solely by evanescent fields and coupled to plasmon resonances in a single gold nanorod. We resolve resonance energy shifts and line broadenings as a function of dipole distance and relative orientation. We demonstrate how These phenomena arise from mode couplings between different vectorial components of the interacting optical near fields, specifically from the coupling of the nanorod to both transverse and longitudinal polarizabilities of the taper apex. KW - Plasmon resonance KW - Coherent exchange KW - Optical near field KW - Plasmonic nanofocusing spectroscopy PY - 2019 DO - https://doi.org/10.1038/s41565-019-0441-y SN - 1748-3387 VL - 14 IS - 7 SP - 698 EP - 704 PB - Nature AN - OPUS4-48028 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Pelkner, Matthias A1 - Casperson, Ralf A1 - Pohl, Rainer A1 - Munzke, Dorit A1 - Becker, Ben T1 - Eddy current testing of composite pressure vessels N2 - The application of composite pressure vessels is of great interest due to tremendous weight saving. Nevertheless, ageing of CFRP (carbon fiber reinforced plastic) composites pressure vessels underlies complex interactions between metallic liner and composite and is not fully understood yet. One main challenge is the application of appropriate testing methods for detecting the influences of pressure cycles and creep behavior on the material. This contribution presents results achieved by using conventional eddy current testing (ET) and high frequency ET. Here, we could show that also conventional ET with low frequencies are useable to investigate pressure vessels of different material combinations like aluminum-CFRP and synthetics-CFRP. KW - CFRP KW - Eddy current KW - Ageing KW - Composite PY - 2019 DO - https://doi.org/10.3233/JAE-171044 VL - 59 IS - 4 SP - 1221 EP - 1226 PB - IOP Publ. Ltd. AN - OPUS4-47803 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Abad Andrade, Carlos Enrique A1 - Florek, S. A1 - Becker-Ross, H. A1 - Huang, M.-D. A1 - de Oliveira Guilherme Buzanich, Ana A1 - Radtke, Martin A1 - Lippitz, Andreas A1 - Hodoroaba, Vasile-Dan A1 - Schmid, Thomas A1 - Heinrich, Hans-Joachim A1 - Recknagel, Sebastian A1 - Jakubowski, Norbert A1 - Panne, Ulrich T1 - Zirconium permanent modifiers for graphite furnaces used in absorption spectrometry: understanding their structure and mechanism of action N2 - The mechanism of action of zirconium permanent modifiers on graphite surfaces was investigated in order to understand its influence on the analytical signal in atomic and molecular absorption spectrometry (AAS/MAS). For this, the molecule formation of CaF was studied, which is used for the indirect analytical determination of fluorine in high-resolution continuum source graphite furnace molecular absorption spectrometry (HR-CS-GFMAS). The kinetics of this reaction was established by monitoring its molecular spectrum at different atomisation temperatures. An Arrhenius plot showed a pseudo-first order reaction with respect to fluorine (n = 1). An intermediate state was isolated, and its structure was elucidated by spectroscopic methods: scanning electron microscopy with energy dispersive X-ray spectroscopy (SEMEDX), X-ray photoelectron spectroscopy (XPS), X-ray absorption spectroscopy (XANES and EXAFS), and Raman microspectroscopy. We propose here a mechanism, where ZrO2 acts as a heterogeneous catalyst: after a pyrolytic step, an intermediate state of ZrO(OCaF) is activated, and at higher temperatures, CaF(g) is released from the zirconium-coated graphite surface. No evidence of the formation of zirconium carbide was found. Consequently, as the CaF formation is catalysed by a heterogeneous catalyst, surface modifications with ZrO2 nanoparticles and ZrO xerogels were investigated in order to increase the surface area. Their influence was evaluated in the molecule formation of CaF, CaCl, CaBr, and CaI. Graphite furnace modification with zirconium oxide nanoparticles proves to be the best choice for fluorine analysis with a signal enhancement of more than eleven times with respect a non-coated graphite furnace. However, the influence of zirconium modifications in the analytical signals of Cl, and I is lower than the F signals or even negative in case of the Br. Understanding zirconium modifiers as heterogeneous catalysts offers a new perspective to AAS and MAS, and reveals the potential of surface analytical methods for development of improved permanent modifiers and graphite furnace coatings. KW - Zirconium KW - HR-CS-MAS KW - Graphite furnace KW - Nanoparticles KW - Xerogel KW - Calcium monofluoride KW - Absorption spectrometry PY - 2018 UR - https://pubs.rsc.org/en/content/articlelanding/2018/ja/c8ja00190a DO - https://doi.org/10.1039/C8JA00190A SN - 0267-9477 VL - 33 IS - 12 SP - 2034 EP - 2042 PB - Royal Society of Chemistry AN - OPUS4-46775 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - de Souza Machado, A. A. A1 - Lau, C. W. A1 - Kloas, W. A1 - Bergmann, J. A1 - Bachelier, J. B. A1 - Faltin, E. A1 - Becker, Roland A1 - Görlich, A. S. A1 - Rillig, M. C. T1 - Microplastics can change soil properties and affect plant performance N2 - Microplastics can affect biophysical properties of the soil. However, little is known about the cascade of events in fundamental levels of terrestrial ecosystems, i.e., starting with the changes in soil abiotic properties and propagating across the various components of soil−plant interactions, including soil microbial communities and plant traits. We investigated here the effects of six different microplastics (polyester fibers, polyamide beads, and four fragment types: polyethylene, polyester terephthalate, polypropylene, and polystyrene) on a broad suite of proxies for soil health and performance of spring onion (Allium fistulosum). Significant changes were observed in plant biomass, tissue elemental composition, root traits, and soil microbial activities. These plant and soil responses to microplastic exposure were used to propose a causal model for the mechanism of the effects. Impacts were dependent on particle type, i.e., microplastics with a shape similar to other natural soil particles elicited smaller differences from control. Changes in soil structure and water dynamics may explain the observed results in which polyester fibers and polyamide beads triggered the most pronounced impacts on plant traits and function. The findings reported here imply that the pervasive microplastic contamination in soil may have consequences for plant performance and thus for agroecosystems and terrestrial biodiversity. KW - Mikroplastik KW - Boden KW - Pflanzenwachstum PY - 2019 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-484181 DO - https://doi.org/10.1021/acs.est.9b01339 SN - 0013-936X SN - 1520-5851 VL - 53 IS - 10 SP - 6044 EP - 6052 PB - ACS AN - OPUS4-48418 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Becker, Roland A1 - Sauer, Andreas A1 - Bremser, Wolfram T1 - Fifteen years of proficiency testing of total petrol hydrocarbon determination in soil: a story of success N2 - The total petrol hydrocarbon (TPH) content in soil is determined by gas chromatographic separation and flame ionisation detection according to ISO 16703 in routine laboratories for about 20 years. The development of the interlaboratory variability observed with this analytical procedure over 15 years in a proficiency testing scheme conducted annually with more than 170 participants is evaluated in detail. A significant improvement of the reproducibility standard deviation among participants is observed over the years and attributed to an increasing familiarity with the procedure. Nevertheless, the determination of TPH in the environmentally relevant mass fraction range between 500 mg/kg and 10 000 mg/kg in soils or sediments is far from reaching the reproducibility standard deviations predicted by the Horwitz curve. It is seen that laboratories with sporadic participation tend to report higher bias, while a core group of laboratories participating on a regular basis arrived at reproducibility standard deviations below 20 %. Results from a given laboratory obtained on two different samples tend to be highly correlated in the same PT round indicating a sound repeatability. Expectedly, the within-laboratory correlation between results from consecutive rounds was considerably lower. However, results from consecutive rounds with a temporal distance of 1, 2 or 3 years revealed largely similar correlations which suggests that the within-laboratory reproducibility adjusts to a constant level at least after a period of 1 year. KW - Mineralölkohlenwasserstoffe KW - Boden KW - Ringversuch KW - Gaschromatographie KW - GC-FID KW - Eingnugsprüfung KW - Proficiency Testing PY - 2019 DO - https://doi.org/10.1007/s00769-019-01383-x SN - 0949-1775 SN - 1432-0517 VL - 24 IS - 4 SP - 289 EP - 296 PB - Springer AN - OPUS4-48419 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Dorgerloh, Ute A1 - Becker, Roland A1 - Kaiser, M. T1 - Evidence for the formation of difluoroacetic acid in chlorofluorocarbon-contaminated ground water N2 - The concentrations of difluoroacetic acid (DFA) and trifluoroacetic acid (TFA) in rainwater and surface water from Berlin, Germany resembled those reported for similar urban areas, and the TFA/DFA ratio in rainwater of 10:1 was in accordance with the literature. In contrast, nearby ground water historically contaminated with 1,1,2-trichloro-1,2,2-trifluoroethane (R113) displayed a TFA/DFA ratio of 1:3. This observation is discussed versus the inventory of microbial Degradation products present in this ground water along with the parent R113 itself. A microbial Transformation of chlorotrifluoroethylene (R1113) to DFA so far has not been reported for environmental media, and is suggested based on well-established mammalian metabolic pathways. KW - Fluoroacetic acid KW - DFA KW - TFA KW - Rainwater KW - Ground water KW - Degradation of refrigerants PY - 2019 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-475569 DO - https://doi.org/10.3390/molecules24061039 SN - 1420-3049 VL - 24 IS - 6 SP - 1039, 1 EP - 6 PB - MDPI CY - Basel AN - OPUS4-47556 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Rietsch, P. A1 - Witte, F. A1 - Sobottka, S. A1 - Germer, G. A1 - Becker, A. A1 - Güttler, Arne A1 - Sarkar, B. A1 - Paulus, B. A1 - Resch-Genger, Ute A1 - Eigler, S. T1 - Diaminodicyanoquinones: Fluorescent dyes with high dipole moments and electron-acceptor properties N2 - Fluorescent dyes are applied in various fields of research,includingsolarcellsandlight-emittingdevices,andas reporters for assays and bioimaging studies.Fluorescent dyes with an added high dipole moment pave the way to nonlinear optics and polarity sensitivity.Redox activity makes it possible to switch the moleculeQsphotophysical properties.Diaminodicyanoquinone derivatives possess high dipole moments,yet only lowfluorescence quantum yields,and have therefore been neglected as fluorescent dyes.Here we investigate the fluorescencepropertiesofdiaminodicyanoquinonesusingacombined theoretical and experimental approach and derive molecules with afluorescence quantum yield exceeding 90%. The diaminodicyanoquinone core moiety provides chemical versatility and can be integrated into novel molecular architectures with unique photophysical features. KW - Dipole moment KW - Fluorescence KW - Quantum yield KW - Quinones PY - 2019 DO - https://doi.org/10.1002/anie.201903204 SN - 1433-7851 SN - 1521-3773 VL - 58 IS - 24 SP - 8235 EP - 8239 PB - Wiley Online Libary CY - Weihnheim AN - OPUS4-48890 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - RPRT A1 - Becker, Wolfram A1 - Stanke, Jürgen T1 - Brandversuche an Stahlbetonfertigstützen - 2. und 3. Teil N2 - Teil 2: Im Auftrage des Deutschen Ausschusses für Stahlbeton wurden weitere Brandversuche an Stahlbetonfertigstützen ausgeführt. Die Versuchsausführung erfolgte nach DIN 4102 (Ausgabe November 1940). Die Übertragung der Versuchsergebnisse auf DIN 4102 ( Ausgabe September 1965) wurde diskutiert. Mit Hilfe der Versuche sollte erreicht werden, daß bei der Neuausgabe von DIN 4102, Blatt 4 zahlreiche weitere Stützenkonstruktionen, insbesondere Fertigteilstützen mit kleinem Querschnitt und hohem Bewehrungsanteil klassifiziert werden können. Die Notwendigkeit der Bewehrung eines als Feuerschutz angewandten Putzes sollte überprüft werden. Weiterhin sollte festgestellt werden, ob anstelle von Drahtgeflecht als Bewehrung einer als Feuerschutz angewendeten vergrößerten Betondeckung auch Baustahlgewebe verwendet werden kann. Es wurde festgestellt, daß als Feuerschutz von Stützen verwendeter Putz vorläufig auch weiterhin bewehrt sein muß, daß anstelle von Drahtgeflecht zur Bewehrung der Betondeckung auch Baustahlgewebe N 98 verwendet werden kann, daß sämtliche Stahlbetonstützen mindestens der Feuerwiderstandsklasse F 30 (feuerhemmend) angehören und sehr viele Stützenkonstruktionen auch in die Feuerwiderstandsklasse F 60 und höher eingereiht werden können, daß auch Stahlbetonstützen nach DIN 4225 mit einer Kantenlänge unter 20 cm mit hohem Bewehrungsanteil bei Anwendung besonderer Maßnahmen die Anforderungen, die an Stützen der Feuerwiderstandsklasse F 90 (feuerbeständig) gestellt werden, erfüllen. Teil 3: Im Auftrage des Deutschen Beton-Vereins e. V. wurden Brandversuche nach DIN 4102 an 12 Stahlbetonstützen ausgeführt. Hierbei sollte der Einfluß einer größeren Betondeckung der Stahleinlagen (3 cm) auf die Feuerwiderstandsfähigkeit von Stahlbetonstützen mit einem Querschnitt von 20 cm x 20 cm und 30 cm x 30 cm untersucht werden. Die Versuchsergebnisse wurden entscheidend von Betonabplatzungen, die zu einem vorzeitigen Freilegen der Längsbewehrung führten, beeinflußt. Die Ursache für das Auftreten der Betonabsprengungen, die von dem Alter, dem Feuchtigkeitsgehalt und der Betongüte der Stützen unabhängig waren, blieb unbekannt. Aus den Ergebnissen läßt sich daher lediglich folgern, daß Stahlbetonstützen mit einer Betondeckung der Stahleinlagen von mindestens 3 cm und einer Mindest-Betongüte von B 225 in die Feuerwiderstandsklasse F 90 bzw. F 120 eingereiht werden können, wenn ihre Mindestdicke 20 bzw. 30 cm, ihr Bewehrungsanteil Fe/Fb ≤ 3 bzw. 6 % beträgt und Betonabplatzungen nicht auftreten. KW - Brandversuch KW - Stahlbetonfertigstütze PY - 1970 SN - 978-3-433-00566-8 SN - 3-433-00566-4 SN - 0171-7197 VL - 215 SP - 1 EP - 96 PB - Ernst & Sohn CY - Berlin AN - OPUS4-62542 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kupke, Johannes A1 - Brombach, Julian A1 - Fang, Yuwen A1 - Wolf, Silver A. A1 - Thrukonda, Lakshmipriya A1 - Ghazisaeedi, Fereshteh A1 - Kuropka, Benno A1 - Hanke, Dennis A1 - Semmler, Torsten A1 - Nordholt, Niclas A1 - Schreiber, Frank A1 - Tedin, Karsten A1 - Lübke-Becker, Antina A1 - Steiner, Ulrich K. A1 - Fulde, Marcus T1 - Heteroresistance in Enterobacter cloacae complex caused by variation in transient gene amplification events N2 - Heteroresistance (HR) in bacteria describes a subpopulational phenomenon of antibiotic resistant cells of a generally susceptible population. Here, we investigated the molecular mechanisms and phenotypic characteristics underlying HR to ceftazidime (CAZ) in a clinical Enterobacter cloacae complex strain (ECC). We identified a plasmid-borne gene duplication-amplification (GDA) event of a region harbouring an ampC gene encoding a β-lactamase bla DHA-1 as the key determinant of HR. Individual colonies exhibited variations in the copy number of the genes resulting in resistance level variation which correlated with growth onset (lag times) and growth rates in the presence of CAZ. GDA copy number heterogeneity occurred within single resistant colonies, demonstrating heterogeneity of GDA on the single-cell level. The interdependence between GDA, lag time and antibiotic treatment and the strong plasticity underlying HR underlines the high risk for misdetection of antimicrobial HR and subsequent treatment failure. KW - Antimicrobial surfaces KW - Biocides KW - Antimicrobial resistance KW - Standardization PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-627057 DO - https://doi.org/10.1038/s44259-025-00082-7 VL - 3 IS - 1 SP - 1 EP - 14 PB - Springer AN - OPUS4-62705 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Mair, Georg W. A1 - Becker, Ben A1 - Duffner, Eric A1 - John, Sebastian T1 - Storage systems for CGH2- systematic improvement of RC&s composite storage systems for compressed hydrogen - systematic improvement of regulations for more attractive storage units N2 - Hydrogen is an attractive energy carrier that requires high effort for safe storage. For ensuring safety they have to undergo a challenging approval process. Relevant standards and regulations for composite cylinders used for the transport of for on-board storage of hydrogen are currently based on deterministic (e.g. ISO 11119-3) or semi-probabilistic (UN GTR No. 13) criteria. This paper analysis the properties of such methods in regards to the evaluation of load cycle strength. Their characteristics are compared with the probabilistic approach of the BAM. Based on Monte-Carlo simulations, the available design range (mean value and scatter of strength criteria) of current concepts were exemplarily estimated. The aspect of small sample sizes is analysed and discussed with respect to the evaluation procedures. T2 - 10th International Conference on Sustainable Energy and Environmental Protection CY - Bled, Slovenia DA - 27.06.2017 KW - Probabilistic KW - Hydrogen KW - Composite KW - Cylinder KW - Regulations KW - Load cycles KW - GTR 13 KW - ISO 11119 PY - 2017 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-416820 SN - 978-961-286-054-7 DO - https://doi.org/10.18690/978-961-286-054-7 SP - 1 EP - 10 PB - University of Maribor Press CY - Maribor, Slovenia AN - OPUS4-41682 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Chowdhary, S. A1 - Moschner, J. A1 - Mikolajczak, D. J. A1 - Becker, M. A1 - Thünemann, Andreas A1 - Kästner, Claudia A1 - Klemczak, D. A1 - Stegemann, A.-K. A1 - Böttcher, C. A1 - Metrangolo, P. A1 - Netz, R. R. A1 - Koksch, B. T1 - The Impact of Halogenated Phenylalanine Derivatives on NFGAIL Amyloid Formation N2 - The hexapeptide hIAPP22–27 (NFGAIL) is known as a crucial amyloid core sequence of the human islet amyloid polypeptide (hIAPP) whose aggregates can be used to better understand the wild‐type hIAPP′s toxicity to β‐cell death. In amyloid research, the role of hydrophobic and aromatic‐aromatic interactions as potential driving forces during the aggregation process is controversially discussed not only in case of NFGAIL, but also for amyloidogenic peptides in general. We have used halogenation of the aromatic residue as a strategy to modulate hydrophobic and aromatic‐aromatic interactions and prepared a library of NFGAIL variants containing fluorinated and iodinated phenylalanine analogues. We used thioflavin T staining, transmission electron microscopy (TEM) and small‐angle X‐ray scattering (SAXS) to study the impact of side‐chain halogenation on NFGAIL amyloid formation kinetics. Our data revealed a synergy between aggregation behavior and hydrophobicity of the phenylalanine residue. This study introduces systematic fluorination as a toolbox to further investigate the nature of the amyloid self‐assembly process. KW - Small-angle X-ray scattering KW - SAXS KW - Nanoparticle KW - Nanostructure KW - Peptide KW - Amyloid PY - 2020 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-518632 DO - https://doi.org/10.1002/cbic.202000373 VL - 21 IS - 24 SP - 3544 EP - 3554 PB - Wiley CY - Weinheim AN - OPUS4-51863 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Köppen, Robert A1 - Emmerling, Franziska A1 - Becker, Roland T1 - Decabromodiphenylethane N2 - Decabromo­diphenyl­ethane [systematic name: 1,1'-ethane-1,2-diylbis(penta­bromo­benzene)], C14H4Br10 (DBDPE), was crystallized from toluene. The mol­ecule shows crystallographic inversion symmetry. The C—Br distances are in the range 1.873 (7)–1.891 (6) Å; inter­molecular BrBr contacts contribute to the formation of ribbons. KW - Single-crystal X-ray study KW - T = 273 K KW - R factor = 0.043 KW - wR factor = 0.121 KW - Data-to-parameter ratio = 20.4 PY - 2007 DO - https://doi.org/10.1107/S1600536807000219 SN - 1600-5368 VL - 63 IS - 2 SP - o585 EP - o586 PB - Munksgaard CY - Copenhagen AN - OPUS4-14565 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Becker, Roland T1 - Querschnittsthema Referenzmaterialien: Planung Ringversuche N2 - Nach einer Erläuterung der international üblichen Definitionen von Referenzmaterialien und Matrix-Referenzmaterialien erfolgt eine Zusammenfassung der spezifischen Anforderungen bei Herstellung und Charakterisierung. Weiterhin werden die unterschiedlichen Anforderungen an die Durchführung von Ringversuchen im Sinne eines Methodenvergleiches, einer Eignungsprüfung von Laboratorien und der Zertifizierung von Matrix-Referenzmaterialien gegenübergestellt. Für den aktuell geplanten ersten Ringversuch zur Quantifizierung von Mikroplastik in Schwebstoffen mittels thermischer Verfahren werden die konkreten technischen Bedingungen zur Herstellung entsprechender Referenzmaterialien einschließlich der Homogenitätsprüfung ihrer Mikroplastikgehalte dargestellt. Die Besonderheiten des Ringversuches vor dem Hintergrund einer Normung der eingesetzten Verfahren werden diskutiert. T2 - Forschungsschwerpunkt „Plastik in der Umwelt – Quellen • Senken • Lösungsansätze“: 2. Workshop des Querschnittsthemas „Analytik und Referenzmaterialien“ CY - Augsburg, Germany DA - 4.7.2018 KW - Mikroplastik KW - Referenzmaterialien KW - Ringversuche KW - Thermische Verfahren KW - Schwebstoffe KW - Methodenvergleich PY - 2018 AN - OPUS4-45681 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -