TY - CHAP A1 - Bonse, Jörn A1 - Kirner, Sabrina V. A1 - Krüger, Jörg ED - Sugioka, K. T1 - Laser-induced periodic surface structures (LIPSS) N2 - Laser-induced periodic surface structures (LIPSS) are a universal phenomenon and can be generated on almost any material by irradiation with linearly polarized radiation. This chapter reviews the current state in the field of LIPSS, which are formed in a “self-ordered” way and are often accompanying materials processing applications. LIPSS can be produced in a single-stage process and enable surface nanostructuring and, in turn, adaption of optical, mechanical, and chemical surface properties. Typically, they feature a structural size ranging from several micrometers down to less than 100 nm and show a clear correlation with the polarization direction of the light used for their generation. Various types of LIPSS are classified, relevant control parameters are identified, and their material-specific formation mechanisms are analyzed for different types of inorganic solids, i.e., metals, semiconductors, and dielectrics. Finally, technological applications featuring surface functionalization in the fields of optics, fluidics, medicine, and tribology are discussed. KW - Laser-induced periodic surface structures (LIPSS) KW - Laser ablation KW - Femtosecond laser KW - Nanostructures KW - Microstructures PY - 2020 SN - 978-3-319-69537-2 DO - https://doi.org/10.1007/978-3-319-69537-2_17-1 SP - 1 EP - 59 PB - Springer Nature CY - Cham, Switzerland ET - 1 AN - OPUS4-51332 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wetzel, Annica A1 - Özcan Sandikcioglu, Özlem A1 - Witt, Julia A1 - Rhode, Michael T1 - Local corrosion properties of high/medium entropy alloys in aqueous environments N2 - High and medium entropy alloys gained increasing academic and industrial interest as novel materials for engineering applications. This project is aiming to clarify and compare the general and local corrosion properties of high entropy alloy CrMnFeCoNi and medium entropy alloy CrCoNi in different aqueous environments. The focus lies on the local corrosion processes that result either from microstructural imperfections (inclusions, defects at grain boundaries etc.) in the base material or processing related changes in the microstructure and/or local composition. The corrosion behavior of the alloys was monitored via potentiodynamic polarization experiments and the local corrosion characteristics were further investigated by means of scanning electrochemical microscopy (SECM). Their passivation behavior was analyzed in three different electrolyte systems (NaCl, H2SO4 and NaClO4; c = 0.1M). The characterization of the surface morphology and composition of the passive film was performed by means of atomic force microscopy (AFM), scanning electron microscopy coupled with energy dispersive X-Ray spectroscopy (SEM/EDX) and X-Ray photoelectron spectroscopy (XPS), respectively. Considering long term corrosion effects, electrochemical work was supported with immersion tests and the analysis of corrosion products by SEM/EDX and XPS depth-profiling. Our results indicate that the medium entropy alloy CrCoNi has a significantly higher corrosion resistance in comparison to the high entropy alloy CrMnFeCoNi. The presentation will summarize some of our results on the mechanistical aspects of the observed high corrosion resistance. T2 - EUROCORR 2020 CY - Online meeting DA - 07.09.2020 KW - High Entropy Alloys KW - Corrosion KW - Medium Entropy Alloys KW - Atomic Forc Microscopy KW - Scanning Kelvin Probe Force Microscopy KW - Potentiodynamic Polarization PY - 2020 AN - OPUS4-53787 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Radtke, Martin A1 - Rakotondrajoa, A. T1 - Machine learning based quantification of synchrotron radiation-induced X-ray fluorescence measurements - a case study N2 - In this work, we describe the use of artificial neural networks for the quantification of X-ray fluorescence measurements. The training data were generated using Monte Carlo simulation, which avoided the use of adapted reference materials. The extension of the available data set by means of an ANN to generate additional data was demonstrated. Particular emphasis was put on the comparability of simulated and experimental data and how the influence of deviations can be reduced. The search for the optimal hyperparameter, manual and automatic, is also described. For the presented case, we were able to train a network with a mean absolute error of 0.1 weight percent for the synthetic data and 0.7 weight percent for a set of experimental data obtained with certified reference materials. KW - Machine learning KW - BAMline KW - XRF KW - Synchrotron KW - Neural network PY - 2020 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-519008 DO - https://doi.org/10.1088/2632-2153/abc9fb SP - 1 EP - 16 PB - IOP Publishing AN - OPUS4-51900 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Radtke, Martin T1 - Machine learning: examples from BAMline N2 - Various applications for artificial intelligence in the context of spectroscopy will be presented. in particular, examples from BAMline will be presented. After a short introduction to synchrotron radiation, artificial intelligence algorithms for the quantification of X-ray fluorescence measurement are discussed. In the second example, information retrieval by natural language processing is discussed. T2 - Analytical Academy CY - Online meeting DA - 02.06.2020 KW - Machine learning KW - BAMline KW - XRF KW - Synchrotron PY - 2020 AN - OPUS4-51898 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Pauw, Brian Richard A1 - Breßler, Ingo T1 - McSAS for SAS analysis: Usage, Benefits and Potential Pitfalls N2 - This talk introduces McSAS, code for analysis of scattering patterns to extract particle size distributions. It highlights how it works, how it should be used, and when it may (not) be applied T2 - Better with Scattering workshop 2020 CY - BAM, Berlin, Germany DA - 16.03.2020 KW - Small angle scattering KW - Software KW - Analysis PY - 2020 AN - OPUS4-51019 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Fortini, Renata A1 - Meyer-Plath, A. A1 - Kehren, D. A1 - Gernert, U. A1 - Agudo Jácome, Leonardo A1 - Sturm, Heinz T1 - Measurement of flexural rigidity of multi-walled carbon nanotubes by Dynamic Scanning Electron Microscopy N2 - In this work the flexural rigidity of individual large diameter multi-walled carbon nanotubes (MWCNTs) was investigated. The bending modulus were obtained by detecting the resonance frequencies of mechanically excited cantilevered carbon nanotubes using the so-called dynamic scanning electron microscopy technique, and applying the Euler–Bernoulli beam theory. For the nanotubes studied, we determined a modulus of up to 160 GPa. This agrees with values reported by other authors for MWCNTs produced by catalytic chemical vapor deposition, however, it is 6-8 times smaller than values reported for single and multi-walled carbon nanotubes produced by arc-discharge synthesis. Toxicological studies with carbon nanotubes have been showing that inhaled airborne nanofibers that reach the deep airways of the respiratory system may lead to serious, asbestos-like lung diseases. These studies suggested that their toxicity critically depends on the fiber flexural rigidity, with high rigidity causing cell lesions. To complement the correlation between observed toxicological effects and fiber rigidities, reliable and routinely applicable measurement techniques for the flexural rigidity of nanofibers are required. KW - Flexural rigidity KW - Bending modulus KW - Resonance frequency KW - Carbon nanotubes KW - Fiber toxicology PY - 2020 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-514190 DO - https://doi.org/10.3390/fib8050031 SN - 2079-6439 VL - 8 IS - 5 SP - 31 PB - MDPI AN - OPUS4-51419 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bäßler, Ralph A1 - Keserović, Amela A1 - Beck, Joana A1 - Sarmiento Klapper, Helmut A1 - Boduch, A. A1 - Dimper, Matthias A1 - Stoljarova, A. A1 - Faes, W. A1 - Zimmer, S. T1 - Metallic Materials for Geothermal Applications N2 - The aim of the work presented was the evaluation of corrosion resistance of various materials in geothermal Waters as a base to create a catalogue of suitable materials for applications in (not only) German geothermal power plants. Users shall be enabled to have a basis for designing such facilities. High alloyed corrosion resistant alloys are suitable and do not cause copper or lead deposition. They shall be chosen for future design of the piping system, either in massive or in cladded form, if crevices formation with non-metallic materials can be prevented! T2 - IFPEN-Workshop: Corrosion in Low-Carbon Energies CY - Online meeting DA - 03.11.2020 KW - Geothermal KW - Corrosion KW - Saline brine PY - 2020 AN - OPUS4-51511 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Altmann, Korinna A1 - Scheid, C. A1 - Steinmetz, H. A1 - Bannick, C.-G. A1 - Abusafia, A. A1 - Dittmer, U. A1 - Braun, Ulrike T1 - Microplastic occurrence in urban sewage systems: Identification of sources for pathways into the environment N2 - All over the world, microplastic (MP) particles (particle size: 1 - 1.000 µm) are found in water, soil, air, biota and even food products. But plenty of these discussed findings are based on a very low number of real datasets, which are extrapolated to general projections. Furthermore, most data are not comparable because the strategies for sampling, sample preparation and detection methods are not harmonised/ or standardised. This would require extensive proficiancy tests. Because of the ubiquity presence and the unclear risks, which might arise from those particles, various political and environmental organisations (i.e. OECD, UNEP, WHO) identify the reduction of plastic entry in the environment as a key challenge for now and the future. This challenge includes the identification of relevant entry pathways but also the demand of harmonised, meaningful and reliable analytical procedures. Regarding this task within the last few years, a fast practical solution for MP analysis has been developed, which includes the steps of representative sampling, adequate sample preparation and fast detection. Sampling is done by fractional filtration over sieves with mesh sizes of 500, 100, 50 and 5 µm [1]. The received samples are measured by ThermoExtraction/Desorption-Gas Chromatography-Mass Spectrometry (TED-GC-MS) [1,2]. for the most abundant polymers used in practice, which are polyethylene (PE), polypropylene (PP), polystyrene (PS), polyethylene terephthalate (PET), polyamide (PA) and acrylate as well as styrene-butadiene-rubber (SBR), a main component of tires. The present presentation will give first-time insight in a comprehensive dataset of microplastic analysis for an exemplary urban sewage system. MP mass contents of different waters at several days, such as greywater, stormwater retention tank, influent and effluent of a wastewater treatment plant (WWTP) within an urban sewage system in Germany are determined. Furthermore, the mass of the polymers found in dry weather and rain weather flow are compared. The use of these large datasets allows first expressive conclusions regarding the contribution of urban sewage system to the MP entry sources in the environments. We found PP and PS in all different waters. Furthermore, there is SBR in influent and also in effluent of the WWTP. Surprisingly, we could also detect hugh amounts of PE in the effluent of the WWTP. T2 - SETAC Europe 2020 CY - Online meeting DA - 03.05.2020 KW - Microplastic analysis KW - TED-GC/MS KW - Microplastic particles KW - Microplastic mass contents PY - 2020 AN - OPUS4-50795 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bennet, Francesca A1 - Hodoroaba, Vasile-Dan A1 - Burr, L. A1 - Schmid, D. T1 - Microprinting and SEM analysis for quantitative evaluation of nanoparticles in solution N2 - Nanoparticle suspensions were microprinted onto TEM grids for subsequent analysis by SEM/TSEM and evaluation of particle numbers using Image J software. Various nanoparticle types, concentrations and printing conditions (temperature, rel. humidity) were evaluated in order to determine the optimal conditions for producing a uniform distribution of particles on the substrate and eliminating the coffee ring effect. T2 - H2020 ACEnano Project Meeting CY - Amsterdam, Netherlands DA - 04.03.2020 KW - Nanoparticle KW - Imaging KW - Microprinting KW - Homogeneous deposition PY - 2020 AN - OPUS4-50584 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Falkenhagen, Jana A1 - Epping, Ruben T1 - Microstructure characterization of oligomers by analysis of UPLC / ESI-TOF-MS reconstructed ion chromatograms N2 - It is a well-known story that copolymers beside their molar mass distribution (MMD) can exhibit a functionality type distribution (FTD), a copolymer composition distribution (CCD), a monomer sequence distribution (MSD) and additionally different topologies within one sample. Small, often isobaric heterogeneities in topology or microstructure can usually not be simply separated chromatographically or distinguished by any common detector. Nowadays a wide range of different analytical separation techniques and multi-detection possibilities are available. The challenge consists in a clever combination of these techniques with a specific approach of data analysis. In this presentation different liquid chromatographic separation modes were combined with Electrospray Time-of-Flight mass spectrometry. The online coupling allows the analysis of reconstructed ion chromatograms (RIC) of each degree of polymerization. While a complete separation often cannot be achieved, the derived retention times and peak widths lead to information on the existence and dispersity of heterogeneities in microstructure or topology, that are otherwise inaccessible This method is suitable to detect small differences in e. g. branching, topology, monomer sequence or tacticity and could potentially be used in production control of oligomeric products or other routinely done analyses to quickly indicate deviations from set parameters. Based on a variety of examples e.g. the topology elucidation of branched EO-PO copolymers, the possibilities and limitations of this approach were demonstrated. T2 - Analyticon 2020 CY - Online meeting DA - 05.11.2020 KW - Microstructure KW - Copolymer KW - LC-MS PY - 2020 AN - OPUS4-51540 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -