TY - JOUR
A1 - Andreoli, A. F.
A1 - Fantin, Andrea
A1 - Kasatikov, S.
A1 - Bacurau, V. P.
A1 - Widom, M.
A1 - Gargarella, P.
A1 - Mazzer, E. M.
A1 - Woodcock, T. G.
A1 - Nielsch, K.
A1 - Coury, F. G.
T1 - The impact of chemical short-range order on the thermophysical properties of medium- and high-entropy alloys
N2 - The unusual behavior observed in the coefficient of thermal expansion and specific heat capacity of CrFeNi, CoCrNi, and CoCrFeNi medium/high-entropy alloys is commonly referred to as the K-state effect. It is shown to be independent of the Curie temperature, as demonstrated by temperature-dependent magnetic moment measurements. CoCrFeNi alloy is chosen for detailed characterization; potential reasons for the K-state effect such as texture, recrystallization, and second-phase precipitation are ruled out. An examination of the electronic structure indicates the formation of a pseudo-gap in the Density of States, which suggests a specific chemical interaction between Ni and Cr atoms upon alloying. Hybrid Monte Carlo/Molecular Dynamic (MC/MD) simulations indicate the presence of non-negligible chemical short-range order (CSRO). Local lattice distortions are shown to be negligible, although deviations around Cr and Ni elements from those expected in a fully disordered structure are experimentally observed by X-ray absorption spectroscopy. The determined bonding distances are in good agreement with MC/MD calculations. A mechanism is proposed to explain the anomalies and calorimetric experiments and their results are used to validate the mechanism.
KW - Mechanical Engineering
KW - Mechanics of Materials
KW - General Materials Science
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-595869
DO - https://doi.org/10.1016/j.matdes.2024.112724
SN - 0264-1275
VL - 238
SP - 1
EP - 15
PB - Elsevier B.V.
AN - OPUS4-59586
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Konert, Florian
A1 - Campari, Alessandro
A1 - Nietzke, Jonathan
A1 - Sobol, Oded
A1 - Paltrinieri, Nicola
A1 - Alvaro, Antonio
T1 - Evaluation of the tensile properties of X65 pipeline steel in compressed gaseous hydrogen using hollow specimens
N2 - Hydrogen has great potential on the path towards decarbonization of the energy and transport sectors and can mitigate the urgent issue of global warming. It can be sustainably produced through water electrolysis with potentially zero emissions, and efficiently used (e.g., in fuel cell systems). Despite its environmental advantages, hydrogen-metal interactions could result in the degradation of the mechanical properties of several structural materials. In order to determine the magnitude of the material degradation in relation to hydrogen exposure, extensive material testing is required. The standardized procedure for in-situ testing for the quantification of the impact of compressed gaseous hydrogen (CGH2) relies on the utilization of an autoclave around the tested specimen. Such test set-up is complex, expensive, time-consuming and requires special equipment, trained personnel, and strict safety procedures. A relatively recent method to circumvent these issues and provide affordable results consists of using hollow specimens, thus applying the hydrogen pressure inside rather than outside the specimen. It allows to reduce the volume of hydrogen by several orders of magnitude and to perform the tests more efficiently and in a safer manner. This study focuses on evaluating the tensile properties of X65 vintage pipeline steel tested in a high-pressure hydrogen environment using hollow specimens. Tests are performed in 6 MPa H2 and Ar at the nominal strain rate of 10−6 s−1 to evaluate the reduced area at fracture and the elongation loss. The effect of surface finishing on crack initiation and propagation is investigated by comparing two different manufacturing techniques. In this way, this study provides insights into the applicability of a novel, reliable, and safe testing method which can be used to assess the hydrogen-assisted ductility loss in metallic materials.
KW - Mechanical Engineering
KW - Hydrogen Embrittlement
KW - SSRT
KW - Hollow specimen
KW - Pipeline steel
KW - In-situ tensile test
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-595887
DO - https://doi.org/10.1016/j.prostr.2024.01.074
SN - 2452-3216
VL - 54
SP - 1
EP - 8
PB - Elsevier B.V.
AN - OPUS4-59588
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - El-Athman, Rukeia
A1 - Rädler, Jörg
A1 - Löhmann, Oliver
A1 - Ariza, Angela
A1 - Muth, Thilo
T1 - The BAM Data Store
N2 - As a partner in several NFDI consortia, the Bundesanstalt für Materialforschung und -prüfung (BAM, German federal institute for materials science and testing) contributes to research data standardization efforts in various domains of materials science and engineering (MSE). To implement a central research data management (RDM) infrastructure that meets the requirements of MSE groups at BAM, we initiated the Data Store pilot project in 2021. The resulting infrastructure should enable researchers to digitally document research processes and store related data in a standardized and interoperable manner. As a software solution, we chose openBIS, an open-source framework that is increasingly being used for RDM in MSE communities.
The pilot project was conducted for one year with five research groups across different organizational units and MSE disciplines. The main results are presented for the use case “nanoPlattform”. The group registered experimental steps and linked associated instruments and chemicals in the Data Store to ensure full traceability of data related to the synthesis of ~400 nanomaterials. The system also supported researchers in implementing RDM practices in their workflows, e.g., by automating data import and documentation and by integrating infrastructure for data analysis.
Based on the promising results of the pilot phase, we will roll out the Data Store as the central RDM infrastructure of BAM starting in 2023. We further aim to develop openBIS plugins, metadata standards, and RDM workflows to contribute to the openBIS community and to foster RDM in MSE.
T2 - 1st Conference on Research Data Infrastructure
DA - 12.09.2023
KW - Research Data Infrastructure
KW - Electronic Lab Notebook (ELN)
KW - openBIS
KW - Research Data Management
PY - 2023
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-596032
DO - https://doi.org/10.52825/CoRDI.v1i.229
VL - 1
SP - 1
EP - 5
AN - OPUS4-59603
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Lu, Xin
A1 - Hicke, Konstantin
A1 - Krebber, Katerina
T1 - Distributed acoustic sensing to monitor ground motion/movement at multi-frequency bands
N2 - A novel distributed acoustic sensing technique is proposed that exploits both phase and amplitude of the Rayleigh backscattered light to quantify the environmental variation. The system employs a wavelength-scanning laser and an imbalanced Mach-Zehnder interferometer to acquire the reflection spectra and the phase of the detected light, respectively. Fading-free and low-frequency measurements are realized via the crosscorrelation of the reflection spectra. The discrete crosscorrelation is used to circumvent the nonlinear frequency sweeping of the laser. Based on the phase of the backscattered light, it is possible to quantify fast environmental variations. The whole system requires no hardware modification of the existing system and its functionality is experimentally validated. The proposed system has the potential to monitor ground motion/movement at very low frequency band like subsidence around mining areas and at high frequency band like earthquakes and vibrations induced by avalanches.
KW - Distributed acoustic sensing
KW - DAS
KW - Distributed fiber optic sensing
KW - Ground motion detection
KW - Subsidence monitoring
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-596129
DO - https://doi.org/10.1109/JLT.2024.3358495
SP - 1
EP - 8
PB - Optical Society und IEEE Photonics Society
AN - OPUS4-59612
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Tang, Chi-Long
A1 - Seeger, Stefan
T1 - Measurement of sub-4 nm particle emission from FFF-3D printing with the TSI Nano Enhancer and the Airmodus Particle Size Magnifier
N2 - The emission of ultrafine particles from small desktop Fused Filament Fabrication (FFF) 3D printers has been frequently investigated in the past years. However, the vast majority of FFF emission and exposure studies have not considered the possible occurrence of particles below the typical detection limit of Condensation Particle Counters and could have systematically underestimated the total particle emission as well as the related exposure risks. Therefore, we comparatively measured particle number concentrations and size distributions of sub-4 nm particles with two commercially available diethylene glycol-based instruments – the TSI 3757 Nano Enhancer and the Airmodus A10 Particle Size Magnifier. Both instruments were evaluated for their suitability of measuring FFF-3D printing emissions in the sub-4 nm size range while operated as a particle counter or as a particle size spectrometer. For particle counting, both instruments match best when the Airmodus system was adjusted to a cut-off of 1.5 nm. For size spectroscopy, both instruments show limitations due to either the fast dynamics or rather low levels of particle emissions from FFF-3D printing in this range. The effects are discussed in detail in this article. The findings could be used to implement sub-4 nm particle measurement in future emission or exposure studies, but also for the development of standard test protocols for FFF-3D printing emissions.
KW - Air pollution
KW - Ultrafine particles
KW - Sub-4nm particles
KW - FFF-3D printing
KW - Emission testing
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-595952
DO - https://doi.org/10.1080/02786826.2024.2320430
SN - 0278-6826
VL - 58
IS - 6
SP - 644
EP - 656
PB - Taylor & Francis
CY - London
AN - OPUS4-59595
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - von Törne, Wipert Jannik
A1 - Steinhäuser, Lorin
A1 - Klyk-Seitz, Urszula-Anna
A1 - Piechotta, Christian
T1 - High-resolution mass spectrometric elucidation of electron ionization induced fragmentation pathways of methylated warfarin and selected hydroxylated species
N2 - The plant secondary metabolite families of coumarin and 4-hydroxy coumarin have a broad pharmacological spectrum ranging from antibacterial to anticancer properties. One prominent member of this substance class is the synthetic but naturally inspired anticoagulant drug and rodenticide warfarin (coumadin). A vast number of publications focus on the identification of warfarin and its major cytochrome P450-mediated phase I metabolites by liquid chromatography (LC) with mass spectrometry (MS) and tandem mass spectrometric (MS/MS) detection techniques. For the first time, electron ionization (EI) induced high-resolution quadrupole time-of-flight mass spectrometric (HR-qToF-MS) data of in-liner derivatized warfarin and selected hydroxylated species is provided in this study as an alternative to LC-MS/MS approaches. Furthermore, the characteristic fragments and fragmentation pathways of the analyzed methyl ethers are concluded. The obtained data of analytical standards, specific deuterated and 13C-labeled compounds prove inductive cleavage of the acyl or acetonyl side chain, methyl migration, and H-migration, along with consequential inductive cleavage as predominant fragmentation routes. Based on the HR-spectral data, commonalities and differences between the analyzed compounds and fragment groups were evaluated with future applicability in structure elucidation and spectra prediction of related compounds.
KW - High-resolution mass spectrometry
KW - Warfarin
KW - Hydroxy warfarin
KW - Fragmentation pathway
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-596025
DO - https://doi.org/10.1016/j.ijms.2024.117220
SN - 1387-3806
VL - 499
SP - 1
EP - 7
PB - Elsevier B.V.
AN - OPUS4-59602
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Wang, Zengquan
A1 - Riechers, Birte
A1 - Derlet, Peter M.
A1 - Maaß, Robert
T1 - Atomic cluster dynamics causes intermittent aging of metallic glasses
N2 - In the past two decades, numerous relaxation or physical aging experiments of metallic glasses have revealed signatures of intermittent atomic-scale processes. Revealed via intensity cross-correlations from coherent scattering using X-ray photon correlation spectroscopy (XPCS), the observed abrupt changes in the time-domain of atomic motion does not fit the picture of gradual slowing down of relaxation times and their origin continues to remain unclear. Using a binary Lennard-Jones model glass subjected to microsecond-long isotherms, we show here that temporally and spatially heterogeneous atomic-cluster activity at different length-scales drive the emergence of highly non-monotonous intensity cross-correlations. The simulated XPCS experiments reveal a variety of time-dependent intensity-cross correlations that, depending on both the structural evolution and the 𝑞-space sampling, give detailed insights into the possible structural origins of intermittent aging measured with XPCS.
KW - Metallic glasses
KW - Aging
KW - Molecular dynamics
KW - XPCS
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-595415
DO - https://doi.org/10.1016/j.actamat.2024.119730
SN - 1359-6454
VL - 267
SP - 1
EP - 9
PB - Elsevier B.V.
CY - Amsterdam, Niederlande
AN - OPUS4-59541
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - von Törne, Wipert Jannik
A1 - Klyk-Seitz, Urszula-Anna
A1 - Piechotta, Christian
T1 - Developing a GC-EI-MS/MS method for quantifying warfarin and five hydroxylated metabolites generated by the Fenton reaction
N2 - AbstractSince the 1950s, Warfarin has been used globally as both a prescription drug and a rodenticide. Research has shown that warfarin and other rodenticides are present in the environment and food chain. However, emerging contaminants are subject to degradation by biotic and abiotic processes and advanced oxidation processes. In some cases, detecting the parent compound may not be possible due to the formation of structurally changed species. This approach aims to identify hydroxylated transformation products of warfarin in a laboratory setting, even after the parent compound has undergone degradation. Therefore, the Fenton reaction is utilized to insert hydroxylation into the parent compound, warfarin, by hydroxyl and hydroperoxyl radicals generated by Fe2+/Fe3+ redox reaction with hydrogen peroxide. Using multiple reaction monitoring, a GC–MS/MS method, incorporating isotopically labeled reference compounds, is used to quantify the expected derivatized species. The analytes are derivatized using trimethyl-3-trifluoromethyl phenyl ammonium hydroxide, and the derivatization yield of warfarin is determined by using isotopically labeled reference compounds. The method has a linear working range of 30 to 1800 ng/mL, with detection limits ranging from 18.7 to 67.0 ng/mL. The analytes are enriched using a C18-SPE step, and the recovery for each compound is calculated. The Fenton reaction generates all preselected hydroxylated transformation products of warfarin. The method successfully identifies that 4′-Me-O-WAR forms preferentially under the specified experimental conditions. By further optimizing the SPE clean-up procedures, this GC–MS-based method will be suitable for detecting transformation products in more complex matrices, such as environmental water samples. Overall, this study provides a better understanding of warfarin’s degradation and offers a robust analytical tool for investigating its transformation products.
KW - Health, Toxicology and Mutagenesis
KW - Pollution
KW - Environmental Chemistry
KW - General Medicine
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-595737
DO - https://doi.org/10.1007/s11356-024-32133-3
SN - 0944-1344
VL - 31
SP - 16986
EP - 16994
PB - Springer Science and Business Media LLC
AN - OPUS4-59573
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Was, G.S.
A1 - Bahn, C.-B.
A1 - Busby, J.
A1 - Cui, B.
A1 - Farkas, D.
A1 - Gussev, M.
A1 - Rigen He, M.
A1 - Hesterberg, J.
A1 - Jiao, Z.
A1 - Johnson, D.
A1 - Kuang, W.
A1 - McMurtrey, M.
A1 - Robertson, I.
A1 - Sinjlawi, A.
A1 - Song, M.
A1 - Stephenson, K.
A1 - Sun, K.
A1 - Swaminathan, Srinivasan
A1 - Wang, M.
A1 - West, E.
T1 - How irradiation promotes intergranular stress corrosion crack initiation
N2 - Irradiation assisted stress corrosion cracking (IASCC) is a form of intergranular stress corrosion cracking that occurs in irradiated austenitic alloys. It requires an irradiated microstructure along with high temperature water and stress. The process is ubiquitous in that it occurs in a wide range of austenitic alloys and water chemistries, but only when the alloy is irradiated. Despite evidence of this degradation mode that dates back to the 1960s, the mechanism by which it occurs has remained elusive. Here, using high resolution electron backscattering detection to analyze local stress-strain states, high resolution transmission electron microscopy to identify grain boundary phases at crack tips, and decoupling the roles of stress and grain boundary oxidation, we are able to unfold the complexities of the phenomenon to reveal the mechanism by which IASCC occurs. The significance of the findings impacts the mechanical integrity of core components of both current and advanced nuclear reactor designs worldwide.
KW - Irradiation
KW - Stress corrosion cracking
KW - Grain boundaries
KW - Oxidation
KW - Austenitic alloys
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-595748
DO - https://doi.org/10.1016/j.pmatsci.2024.101255
SN - 0079-6425
VL - 143
SP - 1
EP - 15
PB - Elsevier
AN - OPUS4-59574
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Karapanagiotis, Christos
A1 - Schukar, Marcus
A1 - Krebber, Katerina
T1 - Verteilte faseroptische Sensoren zur Zustandsüberwachung von Verbundwerkstoff-Druckbehältern
T1 - Distributed fiber optic sensors for structural health monitoring of composite pressure vessels
N2 - In diesem Beitrag geben wir einen umfassenden Überblick über unsere Forschung auf dem Gebiet der verteilten faseroptischen Sensorik für die strukturelle Zustandsüberwachung von Wasserstoffdruckbehältern aus Verbundwerkstoffen. Insbesondere zeigen wir, wie die Integration von faseroptischen Sensoren in Druckbehälter aus Verbundwerkstoffen die Sicherheit erhöht und gleichzeitig die Wartungskosten senkt. Die geringe Größe von Lichtwellenleitern ermöglicht ihre Integration in Verbundwerkstoffstrukturen während des Herstellungsprozesses, wodurch eine kontinuierliche Überwachung sowie eine präzise Erkennung und Lokalisierung von Strukturschäden während des Betriebs der Druckbehälter ermöglicht wird. Wir erörtern auch das Potenzial modernster Signalverarbeitungsmethoden und des maschinellen Lernens für die Weiterentwicklung der vorausschauenden Instandhaltung. Die von uns vorgestellten Anwendungen von faseroptischen Sensoren zeigen, dass sie einen wichtigen Beitrag zur Energiewende hin zu erneuerbaren Energien leisten können.
KW - Verteilte faseroptische Sensoren
KW - Verbundwerkstoffe
KW - Wasserstoff-Druckbehälter
KW - Strukturüberwachung
KW - Maschinelles Lernen
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-596290
DO - https://doi.org/10.1515/teme-2023-0170
SN - 0171-8096
SP - 1
EP - 12
AN - OPUS4-59629
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 - Becker, Tina
A1 - Breese, Philipp Peter
A1 - Metz, Christian
A1 - Altenburg, Simon
T1 - In-situ monitoring for PBF-LB/M processes: Does multispectral optical tomography add value in recognizing process deviations?
N2 - Laser powder bed fusion of metallic components (PBF-LB/M) is gaining acceptance in industry. However, the high costs and lengthy qualification processes required for printed components create the need for more effective in-situ monitoring and testing methods. This article proposes multispectral Optical Tomography (OT) as a new approach for monitoring the PBF-LB/M process. Compared to other methods, OT is a low-cost process monitoring method that uses long-time exposure imaging to observe the build process. However, it lacks time resolution compared to expensive thermographic sensor systems. Monochromatic OT (1C-OT) is already commercially available and observes the building process layer-wise using a single wavelength window in the NIR range. Multispectral OT (nC-OT) utilizes a similar setup but can measure multiple wavelength ranges per location simultaneously. By comparing the classical 1C-OT and nC-OT approaches, this article examines the advantages of nC-OT (two channel OT and RGB-OT) in reducing the false positive rate for process deviations and approximating maximum temperatures for a better comparison between different build processes and materials. This could ultimately reduce costs and time for part qualification. The main goal of this contribution is to assess the advantages of nC-OT compared to 1C-OT for in-situ process monitoring of PBF-LB/M.
T2 - Nolamp 2023
CY - Turku, Finland
DA - 22.08.2023
KW - Thermography
KW - Process Monitoring
KW - Additive manufacturing
KW - BPF-LB/M
KW - In-situ
PY - 2023
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-592498
DO - https://doi.org/10.1088/1757-899X/1296/1/012008
VL - 1296
SP - 1
EP - 11
PB - IOP Publishing
CY - Bristol, UK
AN - OPUS4-59249
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Pech May, Nelson Wilbur
A1 - Tabasco-Novelo, Carolina
A1 - Quintana, Patricia
A1 - Rodriguez-Gattorno, Geonel
A1 - Alvarado-Gil, Juan J.
T1 - Evidence of a Thermal Diffusivity Gap in Sintered Li–Co–Sb–O Solid Solutions
N2 - In this work, the thermal properties of ternary Li₃ₓCo₇₋₄ₓSb₂₊ₓO₁₂ solid solutions are studied for different concentrations in the range 0 ≤ x ≤ 0.7. Samples are elaborated at four different sintering temperatures: 1100, 1150, 1200 and 1250 °C. The effect of increasing the content of Li⁺ and Sb⁵⁺, accompanied by the reduction of Co²⁺, on the thermal properties is studied. It is shown that a thermal diffusivity gap, which is more pronounced for low values of x, can be triggered at a certain threshold sintering temperature (around 1150 °C in this study). This effect is explained by the increase of contact area between adjacent grains. Nevertheless, this effect is found to be less pronounced in the thermal conductivity. Moreover, a new framework for heat diffusion in solids is presented that establishes that both the heat flux and the thermal energy (or heat) satisfy a diffusion equation and therefore highlights the importance of thermal diffusivity in transient heat conduction phenomena.
KW - General Chemical Engineering
KW - General Chemistry
PY - 2023
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-593248
DO - https://doi.org/10.1021/acsomega.2c07557
SN - 2470-1343
VL - 8
IS - 8
SP - 7808
EP - 7815
PB - American Chemical Society (ACS)
CY - Washington, DC
AN - OPUS4-59324
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Mrkwitschka, Paul
A1 - Rühle, Bastian
A1 - Kuchenbecker, Petra
A1 - Löhmann, Oliver
A1 - Lindemann, Franziska
A1 - Hodoroaba, Vasile-Dan
T1 - Embedding and cross-sectioning as a sample preparation procedure for accurate and representative size and shape measurement of nanopowders
N2 - Reliable measurement of the size of polydisperse, complex-shaped commercial nanopowders is a difficult but necessary task, e.g., for regulatory requirements and toxicity risk assessment. Suitable methods exist for the accurate characterization of the size of non-aggregated, stabilized, spherical and monodisperse nanoparticles. In contrast, industrial nanoscale powders usually require dedicated sample preparation procedures developed for the analysis method of choice. These nano-powders tend to agglomerate and/or aggregate, a behavior which in combination with an innate broad particle size distribution and irregular shape often significantly alters the achievable accuracy of the measured size parameters. The present study systematically tests two commercially available nanoscale powders using different sample preparation methods for correlative analysis by scanning electron microscopy, dynamic light scattering, Brunauer–Emmet–Teller method and differential mobility analysis. One focus was set on the sample preparation by embedding nanoparticles in carbon-based hot-mounting resin. Literature on this topic is scarce and the accuracy of the data extracted from cross sections of these particles is unclearly stated. In this paper systematic simulations on the deviation of the size parameters of well-defined series of nanoparticles with different shapes from the nominal value were carried out and the contributing factors are discussed.
KW - Nanopowder
KW - Electron microscopy
KW - Sample preparation
KW - Cross-sectioning
KW - Cerium oxide
KW - Zinc oxide
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-593289
DO - https://doi.org/10.1038/s41598-023-51094-0
SN - 2045-2322
VL - 14
SP - 1
EP - 10
PB - Springer Nature
CY - London
AN - OPUS4-59328
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Asna Ashari, Parsa
A1 - Oh, Hyochan
A1 - Koch, Claudia
T1 - Pathways to the hydrogen economy: A multidimensional analysis of the technological innovation systems of Germany and South Korea
N2 - The global trend towards decarbonization and the demand for energy security have put hydrogen energy into the spotlight of industry, politics, and societies. Numerous governments worldwide are adopting policies and strategies to facilitate the transition towards hydrogen-based economies. To assess the determinants of such transition, this study presents a comparative analysis of the technological innovation systems (TISs) for hydrogen technologies in Germany and South Korea, both recognized as global frontrunners in advancing and implementing hydrogen-based solutions. By providing a multidimensional assessment of pathways to the hydrogen economy, our analysis introduces two novel and crucial elements to the TIS analysis: (i) We integrate the concept of ‘quality infrastructure’ given the relevance of safety and quality assurance for technology adoption and social acceptance, and (ii) we emphasize the social perspective within the hydrogen TIS. To this end, we conducted 24 semi-structured expert interviews, applying qualitative open coding to analyze the data. Our results indicate that the hydrogen TISs in both countries have undergone significant developments across various dimensions. However, several barriers still hinder the further realization of a hydrogen economy. Based on our findings, we propose policy implications that can facilitate informed policy decisions for a successful hydrogen transition.
KW - Hydrogen economy
KW - Technological innovation system
KW - Quality infrastructure
KW - Multidimensional technology adoption
KW - Social acceptance
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-593312
DO - https://doi.org/10.1016/j.ijhydene.2023.08.286
IS - Volume 49, Part D
SP - 405
EP - 421
PB - Elsevier
AN - OPUS4-59331
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Fantin, Andrea
A1 - Lepore, G. O.
A1 - Widom, M.
A1 - Kasatikov, S.
A1 - Manzoni, Anna Maria
T1 - How Atomic Bonding Plays the Hardness Behavior in the Al–Co–Cr–Cu–Fe–Ni High Entropy Family
N2 - A systematic study on a face‐centered cubic‐based compositionally complex alloy system Al–Co–Cr–Cu–Fe–Ni in its single‐phase state is carried out, where a mother senary compound Al₈Co₁₇Cr₁₇Cu₈Fe₁₇Ni₃₃ and five of its suballoys, obtained by removing one element at a time, are investigated and exhaustively analyzed determining the contribution of each alloying element in the solid solution. The senary and the quinaries are compared using experimental techniques including X‐ray absorption spectroscopy, X‐ray diffraction, transmission electron microscopy, and first principles hybrid Monte Carlo/molecular dynamics simulations. Chemical short‐range order and bond length distances have been determined both at the experimental and computational level. Electronic structure and local atomic distortions up to 5.2 Å have been correlated to the microhardness values. A linear regression model connecting hardness with local lattice distortions is presented.
KW - High entropy alloys
KW - EXAFS
KW - Short-range order
KW - Microhardness
KW - Alloy design
KW - Transmission electron microscopy
KW - Lattice distortion
PY - 2023
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-593333
DO - https://doi.org/https://doi.org/10.1002/smsc.202300225
SN - 2688-4046
SP - 1
EP - 12
PB - Wiley
CY - Weinheim
AN - OPUS4-59333
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Klimek, André
A1 - Stelzner, Ludwig
A1 - Hothan, Sascha
A1 - Zehfuß, Jochen
T1 - Influence of thermal strain on concrete spalling
N2 - Understanding the susceptibility to spalling of concrete members in case of fire is important to evaluate the residual load-bearing capacity. The investigations of the spalling phenomenon of a concrete mixture using real scale members are necessary but expensive to carry out. Reducing the specimen size leads to an increase of boundary effects that can result in a reduced spalling or absence of spalling. In this study, fire tests were carried out on unrestrained, single-sided exposed, cuboid shaped specimens (0.6 m x 0.6 m x 0.29 m) as well as unrestrained and steel ring restrained cylindrical specimens (Ø = 0.47 m, h = 0.29 m), which induce different boundary conditions. These fire tests were carried out on two ordinary concrete mixtures. The two mixtures differ only in the type of aggregates (quartz gravel and basalt grit) and were used to investigate the influence of the thermal expansion of the aggregate on the spalling behaviour of the concrete. The results show a significant increase of
the spalling depth due to the restrained thermal expansion achieved by the applied steel rings. Additionally, the type of aggregate has a direct influence on the spalling behaviour of a concrete mixture. The reduction of the boundary effects by the steel rings recreate the test conditions in the centre of a large concrete member. Thus, this type of specimen is suitable to determine the susceptibility to spalling of a material (screening-tests) as preliminary investigations to full scale fire tests.
KW - Spalling
KW - Concrete
KW - Fire test
KW - Restraint
KW - Screening test
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-593350
DO - https://doi.org/10.1617/s11527-023-02274-x
VL - 57
SP - 1
EP - 14
PB - Springer
AN - OPUS4-59335
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Grohmann, Maria
A1 - Niederleithinger, Ernst
A1 - Maack, Stefan
A1 - Buske, Stefan
T1 - Application of iterative elastic SH reverse time migration to synthetic ultrasonic echo data
N2 - The ultrasonic echo technique is widely used in non-destructive testing (NDT) of concrete objects for thickness measurements, geometry determinations and localization of built-in components. To improve ultrasonic imaging of complex concrete structures, we transferred a seismic imaging technique, the Reverse Time Migration (RTM), to NDT in civil engineering. RTM, in contrast to the conventionally used synthetic aperture focusing technique (SAFT) algorithms, considers all wavefield types and thus, can handle complex wave propagations in any direction with no limit on velocity variations and reflector dip. In this paper, we focused on the development, application and evaluation of a two-dimensional elastic RTM algorithm considering horizontally polarized shear (SH) waves only. We applied the elastic SH RTM routine to synthetic ultrasonic echo SH-wave data generated with a concrete model incorporating several steps and circular cavities. As these features can often be found in real-world NDT use cases, their imaging is extremely important. By using elastic SH RTM, we were able to clearly reproduce almost all reflectors inside the concrete model including the vertical step edges and the cross sections of the cavities.We were also capable to show that more features could be mapped compared to SAFT, and that imaging of complex reflectors could be sharpened compared to elastic P-SV (compressional-vertically polarized shear) RTM. Our promising results illustrate that elastic SH RTM has the potential to significantly enhance the reconstruction of challenging concrete structures, representing an important step forward for precise, high-quality ultrasonic NDT in civil engineering.
KW - Ultrasonic echo technique
KW - Concrete structures
KW - Elastic reverse time migration
KW - Synthetic aperture focusing technique
KW - Horizontally polarized shear waves
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-591716
DO - https://doi.org/10.1007/s10921-023-01010-3
SN - 1573-4862
VL - 43
SP - 1
EP - 16
PB - Springer Science and Business Media
CY - Dordrecht
AN - OPUS4-59171
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Zuffa, Caterina
A1 - Cappuccino, Chiara
A1 - Casali, Lucia
A1 - Emmerling, Franziska
A1 - Maini, Lucia
T1 - Liquid reagents are not enough for liquid assisted grinding in the synthesis of (AgBr)(n-pica) n
N2 - This study investigates the mechanochemical reactions between AgBr 3-picolylamine and 4-picolylamine. The use of different stoichiometry ratios of the reagents allows [(AgBr)(n-pica)]n and [(AgBr)2(n-pica)]n to be obtained, and we report the new structures of [(AgBr)2(3-pica)]n and [(AgBr)2(4-pica)]n which are characterized by the presence of the following: (a) infinite inorganic chains, (b) silver atom coordinated only by bromide atoms and (c) argentophilic interactions. Furthermore, we studied the interconversion of [(AgBr)(n-pica)]n/[(AgBr)2(n-pica)]n by mechanochemical and thermal properties. The in situ experiments suggest that [(AgBr)(3-pica)]n is kinetically favoured while [(AgBr)2(3-pica)]n is converted into [(AgBr)(3-pica)]n only with a high excess of the ligand. Finally, the liquid nature of the ligands is not sufficient to assist the grinding process, and the complete reaction is observed with the addition of a small quantity of acetonitrile.
KW - Mechanochemistry
KW - Complex
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-594755
DO - https://doi.org/10.1039/d3cp04791a
SN - 1463-9076
SP - 1
EP - 10
PB - Royal Society of Chemistry (RSC)
AN - OPUS4-59475
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Schwarz, I.
A1 - Rieck, Arielle
A1 - Mehmood, Asad
A1 - Bublitz, R.
A1 - Bongers, L.
A1 - Weuster-Botz, D.
A1 - Fellinger, Tim-Patrick
T1 - PEM Electrolysis in a Stirred-Tank Bioreactor Enables Autotrophic Growth of Clostridium ragsdalei with CO2 and Electrons
N2 - Acetogenic bacteria produce CO2-based chemicals in aqueous media by hydrogenotrophic conversion of CO2, but CO is the preferred carbon and electron source. Consequently, coupling CO2 electrolysis with bacterial fermentation within an integrated bio-electrocatalytical system (BES) is promising, if CO2 reduction catalysts are available for the generation of CO in the complex biotic electrolyte. A standard stirred-tank bioreactor was coupled to a zero-gap PEM electrolysis cell for CO2 conversion, allowing voltage control and separation of the anode in one single cell. The cathodic CO2 reduction and the competing hydrogen evolution enabled in-situ feeding of C. ragsdalei with CO and H2. Proof-of-concept was demonstrated in first batch processes with continuous CO2 gassing, as autotrophic growth and acetate formation was observed in the stirred BES in a voltage range of −2.4 to −3.0 V. The setup is suitable also for other bioelectrocatalytic reactions. Increased currents and lower overvoltages are however required. Atomically-dispersed M−N−C catalysts show promise, if degradation throughout autoclaving can be omitted. The development of selective and autoclavable catalysts resistant to contamination and electrode design for the complex electrolyte will enable efficient bioelectrocatalytic power-to-X systems based on the introduced BES.
KW - Energy Conversion
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-594766
DO - https://doi.org/10.1002/celc.202300344
SN - 2196-0216
SP - 1
EP - 10
PB - Wiley VHC-Verlag
AN - OPUS4-59476
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -