TY - JOUR A1 - Liu, X. A1 - Michalchuk, Adam A1 - Bhattacharya, Biswajit A1 - Emmerling, Franziska A1 - Pulham, C. T1 - High-pressure reversibility in a plastically flexible coordination polymer crystal N2 - Single crystals which exhibit mechanical flexibility are promising materials for advanced technological applications. Before such materials can be used, a detailed understanding of the mechanisms of bending is needed. Using single crystal X-ray diffraction and microfocus Raman spectroscopy, we study in atomic detail the high-pressure response of the plastically flexible coordination polymer [Zn(μ-Cl)2(3,5-dichloropyridine)2]n (1). Contradictory to three-point bending, quasi-hydrostatic compression of (1) is completely reversible, even following compression to over 9 GPa. A structural phase transition is observed at ca. 5 GPa. DFT calculations show this transition to result from the pressure-induced softening of low-frequency vibrations. This phase transition is not observed during three-point-bending. Microfocus synchrotron X-ray diffraction revealed that bending yields significant mosaicity, as opposed to compression. Hence, our studies indicate of overall disparate mechanical responses of bulk flexibility and quasi-hydrostatic compression within the same crystal lattice. We suspect this to be a general feature of plastically bendable materials. KW - High pressure KW - Density functional theory KW - Mechanically flexible crystals PY - 2021 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-530360 DO - https://doi.org/10.1038/s41467-021-24165-x VL - 12 IS - 1 SP - 3871 AN - OPUS4-53036 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Christopher, I A1 - Michalchuk, Adam A1 - Pulham, C. A1 - Morrison, C. T1 - Towards Computational Screening for New Energetic Molecules: Calculation of Heat of Formation and Determination of Bond Strengths by Local Mode Analysis N2 - The reliable determination of gas-phase and solid-state heats of formation are important considerations in energetic materials research. Herein, the ability of PM7 to calculate the gas-phase heats of formation for CNHO-only and inorganic compounds has been critically evaluated, and for the former, comparisons drawn with isodesmic equations and Atom equivalence methods. Routes to obtain solid-state heats of formation for a range of singlecomponent molecular solids, salts, and co-crystals were also evaluated. Finally, local vibrational mode analysis has been used to calculate bond length/force constant curves for seven different chemical bonds occurring in CHNO-containing molecules, which allow for rapid identification of the weakest bond, opening up great potential to rationalise decomposition pathways. Both metrics are important tools in rationalising the design of new energetic materials through computational screening processes. KW - Energetic materials KW - Density functional theory PY - 2021 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-530371 DO - https://doi.org/10.3389/fchem.2021.726357 VL - 9 SP - 726357 AN - OPUS4-53037 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Müller, Ralf A1 - Behrens, Harald A1 - Ageo-Blanco, Boris A1 - Reinsch, Stefan A1 - Wirth, Thomas T1 - Foaming Species and Trapping Mechanisms in Barium Silicate Glass Sealants N2 - Barium silicate glass powders 4 h milled in CO2 and Ar and sintered in air are studied with microscopy, total carbon analysis, differential thermal Analysis (DTA), vacuum hot extraction mass spectroscopy (VHE-MS), Fourier-transformed infrared (FTIR) spectroscopy, X-ray photoelectron spectroscopy (XPS), and time-of-flight secondary-ion mass spectrometry (TOF-SIMS). Intensive foaming of powder compacts is evident, and VHE studies prove that foaming is predominantly caused by carbonaceous species for both milling gases. DTA Shows that the decomposition of BaCO3 particles mix-milled with glass powders occurs at similar temperatures as foaming of compacts. However, no carbonate at the glass surface could be detected by FTIR spectroscopy, XPS, and TOF-SIMS after heating to the temperature of sintering. Instead, CO2 molecules unable to rotate identified by FTIR spectroscopy after milling, probably trapped by mechanical dissolution into the glass bulk. Such a mechanism or microencapsulation in cracks and particle aggregates can explain the contribution of Ar to foaming after intense milling in Ar atmosphere. The amount of CO2 molecules and Ar, however, cannot fully explain the extent of foaming. Carbonates mechanically dissolved beneath the surface or encapsulated in cracks and micropores of particle aggregates are therefore probably the major foaming source. KW - Milling KW - Foaming KW - Glass powder KW - Sintering PY - 2021 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-531227 DO - https://doi.org/10.1002/adem.202100445 SN - 1438-1656 VL - 24 IS - 6 SP - 2100445-1 EP - 2100445-13 AN - OPUS4-53122 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Reichenauer, F. A1 - Wang, Cui A1 - Förster, C. A1 - Boden, P. A1 - Ugur, N. A1 - Báez-Cruz, R. A1 - Kalmbach, J. A1 - Carrella, L. M. A1 - Rentschler, E. A1 - Ramanan, C. A1 - Niedner-Schatteburg, G. A1 - Gerhards, M. A1 - Seitz, M. A1 - Resch-Genger, Ute A1 - Heinze, K. T1 - Strongly Red-Emissive Molecular Ruby [Cr(bpmp)2]3+ Surpasses [Ru(bpy)3]2+ N2 - Gaining chemical control over the thermodynamics and kinetics of photoexcited states is paramount to an efficient and sustainable utilization of photoactive transition metal complexes in a plethora of technologies. In contrast to energies of charge Transfer states described by spatially separated orbitals, the energies of spinflip states cannot straightforwardly be predicted as Pauli Repulsion and the nephelauxetic effect play key roles. Guided by multireference quantum chemical calculations, we report a novel highly luminescent spin-flip emitter with a quantum chemically predicted blue-shifted luminescence. The spin-flip emission band of the chromium complex [Cr(bpmp)2]3+ (bpmp = 2,6-bis(2-pyridylmethyl) pyridine) shifted to higher energy from ca. 780 nm observed for known highly emissive chromium(III) complexes to 709 nm. The photoluminescence quantum yields climb to 20%, and very long excited state lifetimes in the millisecond range are achieved at room temperature in acidic D2O solution. Partial ligand deuteration increases the quantum yield to 25%. The high excited state energy of [Cr(bpmp)2]3+ and its facile reduction to [Cr(bpmp)2]2+ result in a high excited state redox potential. The ligand’s methylene bridge acts as a Brønsted acid quenching the luminescence at high pH. Combined with a pH-insensitive chromium(III) emitter, ratiometric optical pH sensing is achieved with single wavelength excitation. The photophysical and Ground state properties (quantum yield, lifetime, redox potential, and acid/base) of this spin-flip complex incorporating an earth-abundant metal surpass those of the classical precious metal [Ru(α-diimine)3]2+ charge transfer complexes, which are commonly employed in optical sensing and photo(redox) catalysis, underlining the bright future of these molecular ruby analogues. KW - Fluorescence KW - Optical probe KW - Sensor KW - PH KW - Quantum yield KW - Quality assurance KW - Complex KW - Cr(III) KW - Lifetime KW - Ligand KW - Theory PY - 2021 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-530548 DO - https://doi.org/10.1021/jacs.1c05971 VL - 143 IS - 30 SP - 11843 EP - 11855 PB - ACS Publications AN - OPUS4-53054 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Srivastava, Priyanka A1 - Fürstenwerth, Paul Christian A1 - Witte, J. F. A1 - Resch-Genger, Ute T1 - Synthesis and spectroscopic characterization of a fluorescent phenanthrene-rhodamine dyad for ratiometric measurements of acid pH values N2 - We present the rational design, synthesis and spectroscopic characterization of a novel dual excitation, three color emitting, pH-responsive fluorescent probe consisting of two phenanthrene and one rhodamine B units linked by click chemistry. The rhodamine moiety, excitable at λEx = 315 nm and at λEx = 560 nm in its ring-opened form, provides the pH-responsive fluorophore, while the pH-insensitive phenanthrene, excited at λEx = 315 nm, serves as inert internal reference, The presence of two phenanthrene moieties enables a blue monomer and a blueish green excimer emission at 351 nm and 500 nm, respectively. Opening of the rhodamine B spirolactam ring at an acidic pH below 5.0 (pKa = 2.59 ± 0.04) switches on its emission at 580 nm. Simultaneously, the phenanthrene excimer emission decreases caused by a change in orientation of the phenanthrene units, while the monomer emission is barely affected. This sensor design enables ratiometric measurements in the low acidic pH range utilizing the intensity ratios of the rhodamine B and phenanthrene excimer emission at 580 nm and 500 nm. Alternatively, also the intensity ratios of the rhodamine B and the phenanthrene monomer emission could be exploited or the sum of the phenanthrene monomer and excimer fluorescence. To the best of our knowledge, this is the first report of ratiometric sensing utilizing such a versatile type of tricolor emissive dyad probe bearing phenanthrene moieties and showing phenanthrene monomer and excimer emission. KW - Fluorescence KW - Optical probe KW - Sensor KW - Dye KW - Rhodamine KW - Synthesis KW - Photophysics KW - PH KW - Quantum yield KW - Quality assurance KW - Mechanism KW - Chemodosimeter KW - Phenanthrene KW - Ratiometric KW - Dyad PY - 2021 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-530554 DO - https://doi.org/10.1039/d1nj01573g SN - 1144-0546 VL - 45 IS - 31 SP - 13755 EP - 13762 PB - Royal Society of Chemistry AN - OPUS4-53055 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Andresen, Elina A1 - Radunz, Sebastian A1 - Resch-Genger, Ute T1 - Novel PET-Operated Rosamine Sensor Dyes with Substitution Pattern-Tunable pKa Values and Temperature Sensitivity N2 - We present the synthesis and characterization of a family of regioisomerically pure pH-sensitive rosamine fluorophores consisting of xanthene fluorophore cores, which determine the dyes’ photophysical properties such as excitation/emission wavelength, fluorescence quantum yield, and fluorescence lifetime, and differently substituted phenol moieties. The hydroxyl substituent of the phenol moiety introduces a pH sensitivity of the dyes’ fluorescence exploiting a photoinduced electron transfer (PET), that leads to a protonation-induced switching ON of the rosamine emission. Rational tuning of the pKa value of the rosamine fluorescence between 4 to 9 is achieved by altering the substitution pattern and degree of bromination of the phenolic subunits. Additionally, a temperature sensitivity of the fluorescence quantum yield is introduced or suppressed based upon the degree of rigidity of the xanthene scaffold. KW - Fluorescence KW - Optical probe KW - Sensor KW - Dye KW - Rosamine KW - Synthesis KW - Photophysics KW - PH KW - Quantum yield KW - Quality assurancemechanism KW - temperature PY - 2021 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-530562 DO - https://doi.org/10.1039/d1nj02505h VL - 45 IS - 31 SP - 13934 EP - 13940 PB - Royal Society of Chemistry AN - OPUS4-53056 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Vogler, Nico A1 - Drabetzki, Philipp A1 - Lindemann, Mathias A1 - Kühne, Hans-Carsten T1 - Description of the concrete carbonation process with adjusted depth resolved thermogravimetric analysis N2 - The thermal gravimetric analysis (TG) is a common method for the examination of the carbonation progress of cement-based materials. Unfortunately, the thermal properties of some components complicate the evaluation of TG results. Various hydrate phases, like ettringite (AFt), C-S-H and AFm decompose almost simultaneously in the temperature range up to 200 °C. Additionally, physical bound water is released in the same temperature range. In the temperature range between 450 °C and 600 °C the decomposition of calcium hydroxide and amorphous or weakly bound carbonates takes place simultaneously. Carbonates, like calcite, from limestone powder or other additives may be already contained in the noncarbonated sample material. For this research an attempt was made to minimise the influence of these effects. Therefore, differential curves from DTG-results of non-carbonated areas and areas with various states of carbonation of the same sample material were calculated and evaluated. Concretes based on three different types of cement were produced and stored under accelerated carbonation conditions (1 % CO2 in air). The required sample material was obtained by cutting slices from various depth of previously CO2-treated specimen and subsequent grinding. During the sample preparation, a special attention was paid that no additional carbonation processes took place. As reference method for the determination of the carbonation depth the sprayed application of phenolphthalein solution was carried out. Microscopic analysis where examined to confirm the assumptions made previously. Furthermore, the observed effect of encapsulation of calcium hydroxide by carbonates caused by the accelerated carbonation conditions was examined more closely. KW - Microscopy KW - Accelerated carbonation KW - Carbonation behaviour KW - Concrete KW - Thermal Analysis PY - 2021 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-530571 DO - https://doi.org/10.1007/s10973-021-10966-1 VL - 147 IS - 11 SP - 1 EP - 14 PB - Springer AN - OPUS4-53057 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Przyklenk, A. A1 - Balsamo, A. A1 - O'Connor, D. A1 - Evans, Alexander A1 - Yandayan, T. A1 - Akgöz, S. A1 - Flys, O. A1 - Zeleny, V. A1 - Czułek, D. A1 - Meli, F. A1 - Ragusa, C. A1 - Bosse, H. T1 - New European Metrology Network for advanced manufacturing N2 - Advanced manufacturing has been identified as one of the key enabling technologies with applications in multiple industries. The growing importance of advanced manufacturing is reflected by an increased number of publications on this topic in recent years. Advanced manufacturing requires new and enhanced metrology methods to assure the quality of manufacturing processes and the resulting products. However, a high-level coordination of the metrology community is currently absent in this field and consequently this limits the impact of metrology developments on advanced manufacturing. In this article we introduce the new European Metrology Network (EMN) for Advanced Manufacturing within EURAMET, the European Association of National Metrology Institutes (NMIs). The EMN is intended to be operated sustainably by NMIs and Designated Institutes in close cooperation with Stakeholders interested in advanced manufacturing. The objectives of the EMN are to set up a permanent stakeholder dialogue, to develop a Strategic Research Agenda for the metrology input required for advanced manufacturing technologies, to create and maintain a knowledge sharing programme and to implement a web-based service desk for stakeholders. The EMN development is supported by a Joint Network Project within the European Metrology Programme for Innovation and Research. KW - Stakeholder KW - Advanced manufacturing KW - Metrology KW - European Metrology Networks (EMNs) KW - Strategic Research Agenda (SRA), PY - 2021 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-530618 DO - https://doi.org/10.1088/1361-6501/ac0d25 VL - 32 IS - 11 SP - 111001 PB - IOP Publishing AN - OPUS4-53061 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Nelson, G. A1 - Boehm, U. A1 - Bagley, S. A1 - Bajcsy, P. A1 - Bischof, J. A1 - Brown, C. M. A1 - Dauphin, A. A1 - Dobbie, I. M. A1 - Eriksson, J. E. A1 - Faklaris, O. A1 - Fernandez-Rodriguez, J. A1 - Ferrand, A. A1 - Gelman, L, A1 - Gheisari, A. A1 - Hartmann, H. A1 - Kukat, C. A1 - Laude, A. A1 - Mitkovski, M. A1 - Munck, S. A1 - North, A. J. A1 - Rasse, T. A1 - Resch-Genger, Ute A1 - Schuetz, L. C. A1 - Seitz, A. A1 - Strambio-De-Castillia, C. A1 - Swedlow, J. R. A1 - Alexopoulos, I. A1 - Aumayr, K. A1 - Avilov, S. A1 - Bakker, G.-J. A1 - Bammann, R. R. A1 - Bassi, A. A1 - Beckert, H. A1 - Beer, S. A1 - Belyaev, Y. A1 - Bierwagen, J. A1 - Birngruber, K. A. A1 - Bosch, M. A1 - Breitlow, J. A1 - Cameron, L. A. A1 - Chalfoun, J. A1 - Chambers, J. J. A1 - Chen, C.-L. A1 - Conde-Sousa, E. A1 - Corbett, A. D. A1 - Cordelieres, F. P. A1 - Del Nery, E. A1 - Dietzel, R. A1 - Eismann, F. A1 - Fazeli, E. A1 - Felscher, A. A1 - Fried, H. A1 - Gaudreault, N. A1 - Goh, W. I. A1 - Guilbert, T. A1 - Hadleigh, R. A1 - Hemmerich, P. A1 - Holst, G. A. A1 - Itano, M. S. A1 - Jaffe, C. B. A1 - Jambor, H. K. A1 - Jarvis, S. C. A1 - Keppler, A. A1 - Kirchenbuechler, D. A1 - Kirchner, M. A1 - Kobayashi, N. A1 - Krens, G. A1 - Kunis, S. A1 - Lacoste, J. A1 - Marcello, M. A1 - Martins, G. G. A1 - Metcalf, D. J. A1 - Mitchell, C. A. A1 - Moore, J. A1 - Mueller, T. A1 - Nelson, M. S. A1 - Ogg, S. A1 - Onami, S. A1 - Palmer, A. L. A1 - Paul-Gilloteaux, P. A1 - Pimentel, J. A. A1 - Plantard, L. A1 - Podder, S. A1 - Rexhepaj, E. A1 - Royon, A. A1 - Saari, M. A. A1 - Schapman, D. A1 - Schoonderwoert, V. A1 - Schroth-Diez, B. A1 - Schwartz, S. A1 - Shaw, M. A1 - Spitaler, M. A1 - Stoeckl, M. T. A1 - Sudar, D. A1 - Teillon, J. A1 - Terjung, S. A1 - Thuenauer, R. A1 - Wilms, C. D. A1 - Wright, G. D. A1 - Nitschke, R. T1 - QUAREP-LiMi: A community-driven initiative to establish guidelines for quality assessment and reproducibility for instruments and images in light microscopy N2 - A modern day light microscope has evolved from a tool devoted to making primarily empirical observations to what is now a sophisticated, quantitative device that is an integral part of both physical and life science research. Nowadays, microscopes are found in nearly every experimental laboratory. However, despite their prevalent use in capturing and quantifying scientific phenomena, neither a thorough understanding of the principles underlying quantitative imaging techniques nor appropriate knowledge of how to calibrate, operate and maintain microscopes can be taken for granted. This is clearly demonstrated by the well-documented and widespread difficulties that are routinely encountered in evaluating acquired data and reproducing scientific experiments. Indeed, studies have shown that more than 70% of researchers have tried and failed to repeat another scientist’s experiments, while more than half have even failed to reproduce their own experiments1. One factor behind the reproducibility crisis of experiments published in scientific journals is the frequent underreporting of imaging methods caused by a lack of awareness and/or a lack of knowledge of the applied technique2,3. Whereas quality control procedures for some methods used in biomedical research, such as genomics (e.g., DNA sequencing, RNA-seq) or cytometry, have been introduced (e.g. ENCODE4), this issue has not been tackled for optical microscopy instrumentation and images. Although many calibration standards and protocols have been published, there is a lack of awareness and agreement on common Standards and guidelines for quality assessment and reproducibility5. In April 2020, the QUality Assessment and REProducibility for instruments and images in Light Microscopy (QUAREP-LiMi) initiative6 was formed. This initiative comprises imaging scientists from academia and industry who share a common interest in achieving a better understanding of the performance and limitations of microscopes and improved quality control (QC) in light microscopy. The ultimate goal of the QUAREP-LiMi initiative is to establish a set of common QC standards, guidelines, metadata models7,8, and tools9,10, including detailed protocols, with the ultimate aim of improving reproducible advances in scientific research. This White Paper 1) summarizes the major obstacles identified in the field that motivated the launch of the QUAREP-LiMi initiative; 2) identifies the urgent need to address these obstacles in a grassroots manner, through a community of Stakeholders including, researchers, imaging scientists11, bioimage analysts, bioimage informatics developers, corporate partners, Funding agencies, standards organizations, scientific publishers, and observers of such; 3) outlines the current actions of the QUAREPLiMi initiative, and 4) proposes future steps that can be taken to improve the dissemination and acceptance of the proposed guidelines to manage QC. To summarize, the principal goal of the QUAREP-LiMi initiative is to improve the overall quality and reproducibility of light microscope image data by introducing broadly accepted standard practices and accurately captured image data metrics. KW - Fluorescence KW - Microscopy KW - Quality assurance KW - Comparability KW - Imaging KW - Standards KW - Reference materials KW - Reliability KW - Data KW - Reference data KW - Biology KW - Medicine KW - Life science PY - 2021 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-530629 DO - https://doi.org/10.1111/jmi.13041 SN - 1365-2818 VL - 284 IS - 1 SP - 56 EP - 73 PB - Wiley-Blackwell CY - Oxford AN - OPUS4-53062 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Diener, S. A1 - Zocca, Andrea A1 - Günster, Jens T1 - Literature review: Methods for achieving high powder bed densities in ceramic powder bed based additive manufacturing N2 - In additive manufacturing the powder bed based processes binder jetting and powder bed fusion are increasingly used also for the production of ceramics. Final part properties depend to a high percentage on the powder bed density. Therefore, the aim is to use the best combination of powder deposition method and powder which leads to a high packing of the particles. The influence of flowability, powder properties and deposition process on the powder bed density is discussed and the different deposition processes including slurry-based ones are reviewed. It turns out that powder bed density reached by slurry-based layer deposition exceeds conventional powder deposition, however, layer drying and depowdering are extra steps or more time-consuming for the slurry route. Depending on the material properties needed the most suitable process for the part has to be selected. KW - Additive Manufacturing KW - Powder-based processes KW - Powder bed density PY - 2021 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-534992 DO - https://doi.org/10.1016/j.oceram.2021.100191 VL - 8 SP - 100191 PB - Elsevier Ltd. AN - OPUS4-53499 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Gernhard, M. A1 - Rautenberg, Max A1 - Hörner, G. A1 - Weber, B. A1 - Emmerling, Franziska A1 - Roth, C. T1 - Mechanochemical Synthesis as a Greener Way to ProduceIron-based Oxygen Reduction Catalysts N2 - Iron-based catalysts have been reported manifold and studied as platinum group metal (PGM) free alternatives for the catalysis of the oxygen reduction reaction (ORR). However, their sustainable preparation by greener synthesis approaches is usually not discussed. In this work, we propose a new method for the sustainable preparation of such catalysts by using a mechanochemical approach, with no solvents and non-toxic chemicals. The materials obtained from low temperature carbonization (700 °C) exhibit considerable and stable catalytic performance for ORR in alkaline medium. A catalyst obtained from iron hydroxide, tryptophan, dicyandiamide, and ammonium nitrate shows the best electrocatalytic Performance with an overpotential of 921 mV vs. RHE at 0.1 mA/cm2 and an electron transfer number of 3.4. KW - PGM-free catalyst KW - Oxygen Reduction Reaction KW - AEMFC KW - Mössbauer Spectroscopy KW - Sustainable Synthesis PY - 2021 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-535326 DO - https://doi.org/10.1002/zaac.202100194 VL - 647 IS - 22 SP - 2080 EP - 2087 PB - Weinheim-VCH GmbH AN - OPUS4-53532 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kupsch, Andreas A1 - Laquai, René A1 - Müller, Bernd R. A1 - Paciornik, S. A1 - Horvath, J. A1 - Tushtev, K. A1 - Rezwan, K. A1 - Bruno, Giovanni T1 - Evolution of Damage in All-Oxide Ceramic Matrix Composite After Cyclic Loading N2 - While structural ceramics usually display a brittle mechanical behavior, their composites may show nonlinearities, mostly due to microcracking. Herein, the stiffness evolution of a sandwich-like laminate of an Al2O3 15%vol. ZrO2 matrix reinforced with Nextel 610 fibers is studied as a function of number of cycles N in tension. The stiffness of the composite degrades with increasing N, indicating microcracking. However, synchrotron X-ray refraction radiography shows that the internal specific surface of such cracks varies differently. A modeling strategy is developed for the calculation of the equivalent stiffness of mixtures (first the matrix and then the sandwich), based on the Voigt and Reuß schemes. The Bruno–Kachanov model is then used to estimate the initial microcrack density in the matrix (due to the thermal expansion mismatch) and the amount of microcracking increase upon cyclic loading. The stiffness in the composite degrades dramatically already after 20 000 cycles but then remains nearly constant. The combination of mechanical testing, quantitative imaging analysis, and modeling provides insights into the damage mechanisms acting: microcrack propagation is more active than microcrack initiation upon cyclic loading, but the second also occurs. This scenario is similar but not equal to previous results on porous and microcracked ceramics. KW - Ceramic matrix composites KW - Homogenization schemes KW - Microcracking KW - Nonlinear behavior KW - Synchrotron X-ray refraction radiography PY - 2021 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-534541 DO - https://doi.org/10.1002/adem.202100763 SN - 1527-2648 SN - 1438-1656 VL - 24 IS - 6 SP - 2100763 -1 EP - 2100763 -13 PB - VCH GmbH CY - Weinheim AN - OPUS4-53454 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Marklein, B. A1 - Jenning, M. A1 - Konthur, Zoltán A1 - Häupl, T. A1 - Welzel, F. A1 - Nonhoff, U. A1 - Krobitsch, S. A1 - Mulder, D. M. A1 - Koenders, M. I. A1 - Joshua, V. A1 - Cope, A. P. A1 - Shlomchik, M. J. A1 - Anders, H.-J. A1 - Burmester, G. R. A1 - Hensvold, A. A1 - Catrina, A. I. A1 - Rönnelid, J. A1 - Steiner, G. A1 - Skriner, K. T1 - The citrullinated/native index of autoantibodies against hnRNP-DL predicts an individual "window of treatment success" in RA patients N2 - Background: There is a need for biomarker to identify patients “at risk” for rheumatoid arthritis (risk-RA) and to better predict the therapeutic response and in this study we tested the hypothesis that novel native and citrullinated heterogeneous nuclear ribonucleoprotein (hnRNP)-DL autoantibodies could be possible biomarkers. Methods: Using protein macroarray and ELISA, epitope recognition against hnRNP-DL was analysed in sera from different developed RA disease and diagnosed SLE patients. Toll-like receptor (TLR) 7/9 and myeloid Differentiation primary response gene 88 (MyD88)-dependency were studied in sera from murine disease models. HnRNP-DL expression in cultivated cells and synovial tissue was analysed by indirect immunofluorescence, immunoblot and immunohistochemistry. KW - Citrullinated KW - Rheumatoid arthritis KW - Protein-modification KW - Autoantibodies KW - Antigens PY - 2021 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-533682 DO - https://doi.org/10.1186/s13075-021-02603-x SN - 1478-6362 VL - 23 SP - 1 EP - 16 PB - BioMed Central CY - London AN - OPUS4-53368 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Fritsch, Tobias A1 - Farahbod-Sternahl, L. A1 - Serrano Munoz, Itziar A1 - Léonard, F. A1 - Haberland, C. A1 - Bruno, Giovanni T1 - 3D Computed Tomography Quantifies the Dependence of Bulk Porosity, Surface Roughness, and Re-Entrant Features on Build Angle in Additively Manufactured IN625 Lattice Struts N2 - Layer-by-layer additive manufacturing (AM) by means of laser-powder bed Fusion (L-PBF) offers many prospects regarding the design of lattice structures used, for example, in gas turbines. However, defects such as bulk porosity, Surface roughness, and re-entrant features are exacerbated in nonvertical structures, such as tilted struts. The characterization and quantification of these kinds of defects are essential for the correct estimation of fracture and fatigue properties. Herein, cylindrical struts fabricated by L-PBF are investigated by means of X-ray computed tomography (XCT), with the aim of casting light on the dependence of the three kinds of defects (bulk porosity, surface roughness, and re-entrant features) on the build angle. Innovative analysis methods are proposed to correlate shape and position of pores, to determine the angular-resolved Surface roughness, and to quantify the amount of re-entrant surface features, q. A meshing of the XCT surface enables the correlation of q with the classical Surface roughness Pa. This analysis leads to the conclusion that there is a linear correlation between q and Pa. However, it is conjectured that there must be a threshold of surface roughness, below which no re-entrant features can be build. KW - Additive manufacturing KW - Laser powder bed fusion KW - Computed tomography KW - Surface roughness analysis KW - Re-entrant surface feature PY - 2021 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-534728 DO - https://doi.org/10.1002/adem.202100689 IS - 2100689 SP - 1 EP - 8 PB - Wiley-VCH Verlag AN - OPUS4-53472 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kardjilov, N A1 - Manke, I A1 - Hilger, A A1 - Arlt, T A1 - Bradbury, R A1 - Markötter, Henning A1 - Woracek, R A1 - Strobel, M A1 - Treimer, W A1 - Banhart, J T1 - The Neutron Imaging Instrument CONRAD — Post‐Operational Review N2 - The neutron imaging instrument CONRAD was operated as a part of the user program of the research reactor BER‐II at Helmholtz‐Zentrum Berlin (HZB) from 2005 to 2020. The Instrument was designed to use the neutron flux from the cold source of the reactor, transported by a curved neutron guide. The pure cold neutron spectrum provided a great advantage in the use of different neutron optical components such as focusing lenses and guides, solid‐state polarizers, Monochromators and phase gratings. The flexible setup of the instrument allowed for implementation of new methods including wavelength‐selective, dark‐field, phase‐contrast and imaging with polarized neutrons. In summary, these developments helped to attract a large number of scientists and industrial customers, who were introduced to neutron imaging and subsequently contributed to the Expansion of the neutron imaging community. KW - Neutron imaging KW - Neutron scattering KW - Neutron instrument KW - Tomography PY - 2021 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-534190 DO - https://doi.org/10.3390/ jimaging7010011 VL - 7 IS - 11 SP - 7010011 PB - MDPI AN - OPUS4-53419 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Pauzon, C. A1 - Mishurova, Tatiana A1 - Evsevleev, Sergei A1 - Dubiez-Le Goff, S. A1 - Murugesan, S. A1 - Bruno, Giovanni A1 - Hryha, E. T1 - Residual stresses and porosity in Ti-6Al-4V produced by laser powder bed fusion as a function of process atmosphere and component design N2 - The influence of the process gas, laser scan speed, and sample thickness on the build-up of residual stresses and porosity in Ti-6Al-4V produced by laser powder bed fusion was studied. Pure argon and helium, as well as a mixture of those (30% helium), were employed to establish process atmospheres with a low residual Oxygen content of 100 ppm O2. The results highlight that the subsurface residual stresses measured by X-ray diffraction were significantly lower in the thin samples (220 MPa) than in the cuboid samples (645 MPa). This difference was attributed to the shorter laser vector length, resulting in heat accumulation and thus in-situ stress relief. The addition of helium to the process gas did not introduce additional subsurface residual stresses in the simple geometries, even for the increased scanning speed. Finally, larger deflection was found in the cantilever built under helium (after removal from the baseplate), than in those produced under argon and an argon-helium mixture. This result demonstrates that complex designs involving large scanned areas could be subjected to higher residual stress when manufactured under helium due to the gas’s high thermal conductivity, heat capacity, and thermal diffusivity. KW - Additive manufacturing KW - Ti-6Al-4V KW - Residual stress KW - Process atmosphere KW - Helium PY - 2021 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-534209 DO - https://doi.org/10.1016/j.addma.2021.102340 VL - 47 SP - 2340 PB - Elsevier B.V. AN - OPUS4-53420 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Haeckel, A. A1 - Ascher, Lena A1 - Beindorff, N. A1 - Prasad, S. A1 - Garczynska, K. A1 - Guo, J. A1 - Schellenberger, E. T1 - Long‑circulating XTEN864‑annexin A5 fusion protein for phosphatidylserine‑related therapeutic applications N2 - Annexin A5 (anxA5) is a marker for apoptosis, but has also therapeutic potential in cardiovascular diseases, cancer, and, due to apoptotic mimicry, against dangerous viruses, which is limited by the short blood circulation. An 864-amino-acid XTEN polypeptide was fused to anxA5. XTEN864-anxA5 was expressed in Escherichia coli and purified using XTEN as tag. XTEN864-anxA5 was coupled with DTPA and indium-111. After intravenous or subcutaneous injection of 111In-XTEN864-anxA5, mouse blood samples were collected for blood half-life determination and organ samples for biodistribution using a gamma counter. XTEN864-anxA5 was labeled with 6S-IDCC to confirm binding to apoptotic cells using flow cytometry. To demonstrate targeting of atherosclerotic plaques, XTEN864-anxA5 was labeled with MeCAT(Ho) and administered intravenously to atherosclerotic ApoE−/−mice. MeCAT(Ho)-XTEN864-anxA5 was detected together with MeCAT(Tm)-MAC-2 macrophage antibodies by imaging mass cytometry (CyTOF) of aortic root sections. The ability of anxA5 to bind apoptotic cells was not affected by XTEN864. The blood half-life of XTEN864-anxA5 was 13 h in mice after IV injection, markedly longer than the 7-min half-life of anxA5. 96 h after injection, highest amounts of XTEN864-anxA5 were found in liver, spleen, and kidney. XTEN864-anxA5 was found to target the adventitia adjacent to atherosclerotic plaques. XTEN864-anxA5 is a long-circulating fusion protein that can be efficiently produced in E. coli and potentially circulates in humans for several days, making it a promising therapeutic drug. KW - Programmed cell death KW - LA/ICP-MS Imaging KW - Medicinal application PY - 2021 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-533811 DO - https://doi.org/10.1007/s10495-021-01686-w VL - 26 IS - 9-10 SP - 534 EP - 547 PB - Springer AN - OPUS4-53381 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Schwabe, M. A1 - Griep, S. A1 - Schmidtberg, H. A1 - Plarre, Rüdiger A1 - Goesmann, A. A1 - Vilcinskas, A. A1 - Vogel, H. A1 - Brinkrolf, K. T1 - Next-Generation Sequencing Analysis of the Tineola bisselliella Larval Gut Transcriptome Reveals Candidate Enzymes for Keratin Digestion N2 - The clothes moth Tineola bisselliella is one of a few insects that can digest keratin, leading to the destruction of clothing, textiles and artwork. The mechanism of keratin digestion is not yet fully understood, partly reflecting the lack of publicly available genomic and transcriptomic data. Here we present a high-quality gut transcriptome of T. bisselliella generated from larvae reared on keratin-rich and keratin-free diets. The overall transcriptome consists of 428,221 contigs that were functionally annotated and screened for candidate enzymes involved in keratin utilization. As a mechanism for keratin digestion, we identified cysteine synthases, cystathionine β-synthases and cystathionine γ-lyases. These enzymes release hydrogen sulfite, which may reduce the disulfide bonds in keratin. The dataset also included 27 differentially expressed contigs with trypsin domains, among which 20 were associated with keratin feeding. Finally, we identified seven collagenases that were upregulated on the keratin-rich diet. In addition to this enzymatic repertoire potentially involved in breaking down keratin, our analysis of poly(A)-enriched and poly(A)-depleted transcripts suggested that T. bisselliella larvae possess an unstable intestinal microbiome that may nevertheless contribute to keratin digestion KW - Insect biotechnology KW - Gene expression KW - RNA-Sequencing KW - Transcriptomics KW - Tineola bisselliella KW - Keratin PY - 2021 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-529902 DO - https://doi.org/10.3390/genes12081113 VL - 12 IS - 8 SP - 1113 PB - MDPI AN - OPUS4-52990 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Völker, Christoph A1 - Firdous, R. A1 - Kruschwitz, Sabine A1 - Stephan, D. T1 - Sequential learning to accelerate discovery of alkali-activated binders N2 - Alkali-activated binders (AAB) can provide a clean alternative to conventional cement in terms of CO2 emissions. However, as yet there are no sufficiently accurate material models to effectively predict the AAB properties, thus making optimal mix design highly costly and reducing the attractiveness of such binders. This work adopts sequential learning (SL) in high-dimensional material spaces (consisting of composition and processing data) to find AABs that exhibit desired properties. The SL approach combines machine learning models and feedback from real experiments. For this purpose, 131 data points were collected from different publications. The data sources are described in detail, and the differences between the binders are discussed. The sought-after target property is the compressive strength of the binders after 28 days. The success is benchmarked in terms of the number of experiments required to find materials with the desired strength. The influence of some constraints was systematically analyzed, e.g., the possibility to parallelize the experiments, the influence of the chosen algorithm and the size of the training data set. The results show the advantage of SL, i.e., the amount of data required can potentially be reduced by at least one order of magnitude compared to traditional machine learning models, while at the same time exploiting highly complex information. This brings applications in laboratory practice within reach. KW - Alkali-activated binders KW - Machine learning KW - Sequential learning KW - Materials by design KW - Materials informatics PY - 2021 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-531376 DO - https://doi.org/10.1007/s10853-021-06324-z SN - 0022-2461 SN - 1573-4803 VL - 56 SP - 15859 EP - 15881 PB - Springer CY - Dordrecht AN - OPUS4-53137 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Reichelt, Manuel A1 - Cappella, Brunero T1 - Micro- and nanowear of self-mated steel generated and studied with an AFM at the single asperity level N2 - We show for the first time tribotests performed with self-mated 100Cr6 steel, taking advantage of an AFM, employed as a tribometer for the tribotests as well as for the inspection of wear of both tribopartners. Emphasis is put on the morphology of the scars, on wear particles, and on wear of the “colloidal” particles glued on the AFM cantilever. Measurements demonstrate the possibility of characterizing single asperity events leading to very small wear. We highlight several phenomena, which are elementary key constituents of tribological processes. Such phenomena, probably occurring also at the macroscale, can be detected, identified, and characterized with high spatial and time resolution only at the nanoscale, thus giving insight into conditions and causes of their emergence. KW - Nanowear KW - Atomic force microscope KW - 100Cr6 (AISI 52100) steel KW - Wear particles KW - Single asperity contact KW - Particle transfer KW - Zero wear PY - 2021 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-531389 DO - https://doi.org/10.3389/fmech.2021.722434 SN - 2297-3079 VL - 7 SP - 1 EP - 16 PB - Frontiers Media CY - Lausanne AN - OPUS4-53138 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Mirtsch, Mona A1 - Blind, K. A1 - Koch, Claudia A1 - Dudek, Gabriele T1 - Information security management in ICT and non-ICT sector companies: A preventive innovation perspective N2 - Despite the growing dependence of companies on information technology and the increasingly negative impact of security incidents worldwide, there is little research on the management of information security at the company level. This paper seeks to expand knowledge on the implementation of an information security management system based on the widely used international standard ISO/IEC 27001. We present motives, experienced impacts, and obstacles related to ISO/IEC 27001 implementation using data from a survey of 125 ISO/IEC 27001 certified companies in Germany. Since adoption rates vary between ICT and non-ICT sector companies, we highlight sector-related variations. We classify the adoption of this standard as a preventive organizational innovation and apply Structural Equation Modeling to unearth explanations for the comparatively low adoption of this management system standard among companies outside the ICT sector. We, therefore, derive recommendations for policymakers, standardization, and certification bodies to foster its diffusion. KW - Information Security KW - ISO/IEC 27001 KW - Management system standard KW - Certification KW - Information security management system (ISMS) KW - Preventive Innovation KW - Resource-based-view KW - Institutional theory PY - 2021 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-531037 DO - https://doi.org/10.1016/j.cose.2021.102383 SN - 0167-4048 VL - 109 IS - 10 SP - 1 EP - 23 PB - Elsevier Ltd. AN - OPUS4-53103 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Magkos, Sotirios A1 - Kupsch, Andreas A1 - Bruno, Giovanni T1 - Suppression of Cone-Beam Artefacts with Direct Iterative Reconstruction Computed Tomography Trajectories (DIRECTT) N2 - The reconstruction of cone-beam computed tomography data using filtered back-projection algorithms unavoidably results in severe artefacts. We describe how the Direct Iterative Reconstruction of Computed Tomography Trajectories (DIRECTT) algorithm can be combined with a model of the artefacts for the reconstruction of such data. The implementation of DIRECTT results in reconstructed volumes of superior quality compared to the conventional algorithms. KW - DIRECTT KW - Iterative method KW - Signal processing KW - X-ray imaging KW - Computed tomography PY - 2021 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-531085 DO - https://doi.org/10.3390/jimaging7080147 SN - 2313-433X) VL - 7 IS - 8 SP - 147 - 1 EP - 147 -9 PB - MDPI CY - Basel, Switzerland AN - OPUS4-53108 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Khrapov, D. A1 - Kozadayeva, M. A1 - Manabaev, K. A1 - Panin, A. A1 - Sjöström, W. A1 - Koptyug, A. A1 - Mishurova, Tatiana A1 - Evsevleev, Sergei A1 - Meinel, Dietmar A1 - Bruno, Giovanni A1 - Cheneler, D. A1 - Surmenev, R. A1 - Surmeneva, M. T1 - Different approaches for manufacturing Ti-6Al-4V alloy with triply periodic minimal surface sheet-based structures by electron beam melting N2 - Targeting biomedical applications, Triply Periodic Minimal Surface (TPMS) gyroid sheet-based structures were successfully manufactured for the first time by Electron Beam Melting in two different production Themes, i.e., inputting a zero (Wafer Theme) and a 200 µm (Melt Theme) wall thickness. Initial assumption was that in both cases, EBM manufacturing should yield the structures with similar mechanical properties as in a Wafer-mode, as wall thickness is determined by the minimal beam spot size of ca 200 µm. Their surface morphology, geometry, and mechanical properties were investigated by means of electron microscopy (SEM), X-ray Computed Tomography (XCT), and uniaxial tests (both compression and tension). Application of different manufacturing Themes resulted in specimens with different wall thicknesses while quasi-elastic gradients for different Themes was found to be of 1.5 GPa, similar to the elastic modulus of human cortical bone tissue. The specific energy absorption at 50% strain was also similar for the two types of structures. Finite element simulations were also conducted to qualitatively analyze the deformation process and the stress distribution under mechanical load. Simulations demonstrated that in the elastic regime wall, regions oriented parallel to the load are primarily affected by deformation. We could conclude that gyroids manufactured in Wafer and Melt Themes are equally effective in mimicking mechanical properties of the bones. KW - Electron beam melting KW - Scaffold KW - Lightweight structures KW - Computed tomography PY - 2021 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-531595 DO - https://doi.org/10.3390/ma14174912 SN - 1996-1944 VL - 14 IS - 17 SP - 1 EP - 21 PB - MDPI CY - Basel AN - OPUS4-53159 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Feiler, Torvid A1 - Bhattacharya, Biswajit A1 - Michalchuk, Adam A1 - Rhim, S.-Y. A1 - Schöder, V. A1 - List-Kratochvil, E. A1 - Emmerling, Franziska T1 - Tuning the mechanical flexibility of organic molecular crystals by polymorphism for flexible optical waveguides N2 - The ability to selectively tune the optical and the mechanical properties of organic molecular crystals offers a promising approach towards developing flexible optical devices. These functional properties are sensitive to crystallographic packing features and are hence expected to vary with polymorphic modification. Using as a model system the photoluminescent material 4-bromo-6-[(6-chloropyridin-2-ylimino)methyl]phenol (CPMBP), we herein demonstrate the simultaneous tuning of mechanical flexibility and photoluminescence properties via polymorphism. Two new polymorphic forms of CPMBP were obtained from a solution and fully characterised using a combination of experiments and density functional theory simulations. These polymorphic forms exhibit remarkably distinct mechanical properties and an order of magnitude difference in photoluminescence quantum yield. The mechanically plastic form has a higher quantum yield than the brittle polymorphic form. However, their photoluminescence emission profile is largely unaffected by the observed polymorphism, thereby demonstrating that the optical properties and bulk mechanical properties can in principle be tuned independently. By distinguishing between active (involving absorption and emission) and passive (involving no absorption) light propagation, the waveguiding properties of the plastic form of CPMBP (form II) were explored using the straight and bent crystals to highlight the potential applications of CPMBP in designing flexible optical devices. Our results demonstrated that polymorph engineering would be a promising avenue to achieve concurrent modulation of the optical and mechanical properties of photoluminescent molecular crystals for next-generation flexible optical device applications. KW - Mechanochemistry KW - Flexible PY - 2021 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-532075 DO - https://doi.org/10.1039/d1ce00642h VL - 23 IS - 34 SP - 5815 EP - 5825 PB - Royal Society of Chemistry CY - London AN - OPUS4-53207 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Quiroz, J. A1 - de Oliveira, P. F. M. A1 - Shetty, S. A1 - Oropeza, F. A1 - Peña O’Shea, V. A1 - Rodrigues, L. A1 - Rodrigues, M. A1 - Torresi, R. A1 - Emmerling, Franziska A1 - Camargo, P. T1 - Bringing earth-abundant plasmonic catalysis to light: Gram-scale mechanochemical synthesis and tuning of activity by dual excitation of antenna and reactor sites N2 - The localized surface plasmon resonance (LSPR) excitation in plasmonic nanoparticles (NPs) in the visible and near-infrared ranges is currently at the forefront of improving photocatalytic performances via plasmonic photocatalysis. One bottleneck of this field is that the NPs that often display the best optical properties in the visible and near-infrared ranges are based on expensive noble metals such as silver (Ag) and gold (Au). While earth-abundant plasmonic materials have been proposed together with catalytic metals in antenna–reactor systems, their performances remain limited by their optical properties. Importantly, the synthesis of plasmonic photocatalysts remains challenging in terms of scalability while often requiring several steps, high temperatures, and special conditions. Herein, we address these challenges by developing a one-pot, gram-scale, room-temperature synthesis of earth-abundant plasmonic photocatalysts while improving their activities beyond what has been dictated by the LSPR excitation of the plasmonic component. We describe the mechanochemical synthesis of earth-abundant plasmonic photocatalysts by using MoO3 (antenna) and Au (reactor) NPs as a proof-of-concept example and demonstrate that the dual plasmonic excitation of antenna and reactor sites enables the tuning of plasmonic photocatalytic performances toward the reductive coupling of nitrobenzene to azobenzene as a model reaction. In addition to providing a pathway to the facile and gram-scale synthesis of plasmonic photocatalysts, the results reported herein may open pathways to improved activities in plasmonic catalysis. KW - MoO3 KW - Au nanoparticles KW - Localized surface plasmon resonance KW - Plasmonic photocatalysis KW - Nitrobenzene reduction PY - 2021 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-532089 DO - https://doi.org/10.1021/acssuschemeng.1c02063 VL - 9 IS - 29 SP - 9750 EP - 9760 PB - American Chemical Society CY - Washington, DC AN - OPUS4-53208 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Schoknecht, Ute A1 - Mathies, Helena A1 - Lisec, Jan T1 - Leaching and transformation of film preservatives in paints induced by combined exposure to ultraviolet radiation and water contact under controlled laboratory conditions N2 - Stormwater from urban areas can transport biocidally active substances and related transformation products from buildings into the environment. The occurrence of these substances in urban runoff depends on the availability of water, and on ultraviolet radiation exposure that causes photolytic reactions. In a systematic laboratory study, painted test specimens were exposed to either ultraviolet radiation, water contact, or a combination of both. Leaching of the biocidally active substances carbendazim, diuron, octylisothiazolinone, terbutryn, and selected transformation products of terbutryn and diuron were observed under various exposure conditions. Remaining concentrations of these substances in the paint were quantified. It was demonstrated that the distribution of active substances and transformation products in eluates and in the coatings themselves differs with exposure conditions. Strategies for environmental monitoring of biocide emissions need to consider the most relevant transformation products. However, environmental concentrations of biocidally active substances and transformation products depend on earlier exposure conditions. As a consequence, monitoring data cannot describe emission processes and predict expected leaching of biocidally active substances from buildings if the data are collected only occasionally. KW - Substance release KW - Construction products KW - Biocides KW - Transformation KW - UV radiation KW - Water contact PY - 2021 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-532114 DO - https://doi.org/10.3390/w13172390 SN - 2073-4441 VL - 13 IS - 17 SP - 1 EP - 16 PB - MDPI CY - Basel AN - OPUS4-53211 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Artinov, Antoni A1 - Meng, Xiangmeng A1 - Bachmann, Marcel A1 - Rethmeier, Michael T1 - Numerical analysis of the partial penetration high power laser beam welding of thick sheets at high process speeds N2 - The present work is devoted to the numerical analysis of the high-power laser beam welding of thick sheets at different welding speeds. A three-dimensional transient multi-physics numerical model is developed, allowing for the prediction of the keyhole geometry and the final penetration depth. Two ray tracing algorithms are implemented and compared, namely a standard ray tracing approach and an approach using a virtual mesh refinement for a more accurate calculation of the reflection points. Both algorithms are found to provide sufficient accuracy for the prediction of the keyhole depth during laser beam welding with process speeds of up to 1.5 m/min. However, with the standard algorithm, the penetration depth is underestimated by the model for a process speed of 2.5 m/min due to a trapping effect of the laser energy in the top region. In contrast, the virtually refined ray tracing approach results in high accuracy results for process speeds of both 1.5 m/min and 2.5 m/min. A detailed study on the trapping effect is provided, accompanied by a benchmark including a predefined keyhole geometry with typical characteristics for the high-power laser beam welding of thick plates at high process speed, such as deep keyhole, inclined front keyhole wall, and a hump. KW - High-power laser beam welding KW - High process speeds KW - Deep penetration KW - Numerical modeling KW - Ray tracing PY - 2021 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-532170 DO - https://doi.org/10.3390/met11081319 SN - 2075-4701 VL - 11 IS - 8 SP - 1 EP - 16 PB - MDPI CY - Basel AN - OPUS4-53217 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Munir, R. A1 - Lisec, Jan A1 - Jaeger, Carsten A1 - Zaidi, N. T1 - Abundance, fatty acid composition and saturation index of neutral lipids in colorectal cancer cell lines N2 - Lipid droplets, the dynamic organelles that store Triglycerides (TG) and cholesterol esters (CE), are highly accumulated in colon cancer cells. This work studies the TG and CE subspecies profile in colon carcinoma cell lines, SW480 derived from primary tumor, and SW620 derived from a metastasis of the same tumor. It was previously reported that the total TG and CE content is dramatically higher in SW620 cells; however, TG and CE subspecies profile has not been investigated in detail. The work presented here confirms that the total TG and CE Content is significantly higher in the SW620 cells. Moreover, the fatty acid (FA) composition of TG is significantly altered in the SW620 cells, with significant decrease in the abundance of saturated triglycerides. This resulted in a significantly decreased TG saturation index in the SW620 cells. The saturation index of CE was also significantly decreased in the SW620 cells. KW - Mass Spectroscopy KW - Metabolomics KW - Cancer PY - 2021 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-533504 DO - https://doi.org/10.18388/abp.2020_5465 VL - 68 IS - 1 SP - 1 EP - 4 PB - ABP Acta Biochimica Polonica AN - OPUS4-53350 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Lisec, Jan A1 - Kobelt, D. A1 - Walther, W. A1 - Mokrizkij, M. A1 - Grötzinger, C. A1 - Jaeger, Carsten A1 - Baum, K. A1 - Simon, M. A1 - Wolf, J. A1 - Beindorf, N. A1 - Brenner, W. A1 - Stein, U. T1 - Systematic Identification of MACC1-Driven Metabolic Networks in Colorectal Cancer N2 - MACC1 is a prognostic and predictive metastasis biomarker for more than 20 solid Cancer entities. However, its role in cancer metabolism is not sufficiently explored. Here, we report on how MACC1 impacts the use of glucose, glutamine, lactate, pyruvate and fatty acids and show the comprehensive analysis of MACC1-driven metabolic networks. We analyzed concentrationdependent changes in nutrient use, nutrient depletion, metabolic tracing employing 13C-labeled substrates, and in vivo studies. We found that MACC1 permits numerous effects on cancer metabolism. Most of those effects increased nutrient uptake. Furthermore, MACC1 alters metabolic pathways by affecting metabolite production or turnover from metabolic substrates. MACC1 supports use of glucose, glutamine and pyruvate via their increased depletion or altered distribution within metabolic pathways. In summary, we demonstrate that MACC1 is an important regulator of metabolism in cancer cells. KW - Mass Spectroscopy KW - Metabolomics KW - Cancer PY - 2021 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-533526 DO - https://doi.org/10.3390/cancers13050978 VL - 13 IS - 5 SP - 1 EP - 22 PB - MDPI Journal Cancers AN - OPUS4-53352 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Adamus, A. A1 - Ali, I. A1 - Vasileiadis, V. A1 - Al-Hileh, L. A1 - Lisec, Jan A1 - Frank, M. A1 - Seitz, G. A1 - Engel, N. T1 - Vincetoxicum arnottianum modulates motility features and metastatic marker expression in pediatric rhabdomyosarcoma by stabilizing the actin cytoskeleton N2 - Background: Prevention of metastatic invasion is one of the main challenges in the treatment of alveolar rhabdomyosarcoma. Still the therapeutic options are limited. Therefore, an anti-tumor screening was initiated focusing on the anti-metastatic and anti-invasion properties of selected medicinal plant extracts and phytoestrogens, already known to be effective in the prevention and treatment of different cancer entities. Methods: Treatment effects were first evaluated by cell viability, migration, invasion, and colony forming assays on the alveolar rhabdomyosarcoma cell line RH-30 in comparison with healthy primary cells. Results: Initial anti-tumor screenings of all substances analyzed in this study, identified the plant extract of Vincetoxicum arnottianum (VSM) as the most promising candidate, harboring the highest anti-metastatic potential. Those significant anti-motility properties were proven by a reduced ability for migration (60%), invasion (99%) and colony formation (61%) under 48 h exposure to 25 μg/ml VSM. The restricted motility features were due to an induction of the stabilization of the cytoskeleton – actin fibers were 2.5-fold longer and were spanning the entire cell. Decreased proliferation (PCNA, AMT, GCSH) and altered metastasis (e. g. SGPL1, CXCR4, stathmin) marker expression on transcript and protein level confirmed the significant lowered tumorigenicity under VSM treatment. Finally, significant alterations in the cell metabolism were detected for 25 metabolites, with levels of uracil, N-acetyl serine and propanoyl phosphate harboring the greatest alterations. Compared to the conventional therapy with cisplatin, VSM treated cells demonstrated a similar metabolic shutdown of the primary cell metabolism. Primary control cells were not affected by the VSM treatment. Conclusions: This study revealed the VSM root extract as a potential, new migrastatic drug candidate for the putative treatment of pediatric alveolar rhabdomyosarcoma with actin filament stabilizing properties and accompanied by a marginal effect on the vitality of primary cells. KW - Mass Spectroscopy KW - Metabolomics KW - Cancer PY - 2021 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-533530 DO - https://doi.org/10.1186/s12906-021-03299-x VL - 21 IS - 1 PB - Springer Nature AN - OPUS4-53353 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Klewe, Tim A1 - Strangfeld, Christoph A1 - Ritzer, Tobias A1 - Kruschwitz, Sabine T1 - Combining Signal Features of Ground-Penetrating Radar to Classify Moisture Damage in Layered Building Floors N2 - To date, the destructive extraction and analysis of drilling cores is the main possibility to obtain depth information about damaging water ingress in building floors. The time- and costintensive procedure constitutes an additional burden for building insurances that already list piped water damage as their largest item. With its high sensitivity for water, a ground-penetrating radar (GPR) could provide important support to approach this problem in a non-destructive way. In this research, we study the influence of moisture damage on GPR signals at different floor constructions. For this purpose, a modular specimen with interchangeable layers is developed to vary the screed and insulation material, as well as the respective layer thickness. The obtained data set is then used to investigate suitable signal features to classify three scenarios: dry, damaged insulation, and damaged screed. It was found that analyzing statistical distributions of A-scan features inside one B-scan allows for accurate classification on unknown floor constructions. Combining the features with multivariate data analysis and machine learning was the key to achieve satisfying results. The developed method provides a basis for upcoming validations on real damage cases. KW - Radar KW - Material Moisture KW - Non-destructive testing KW - Signal Features KW - Civil Engineering KW - Machine Learning PY - 2021 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-533606 DO - https://doi.org/10.3390/app11198820 VL - 11 IS - 19 SP - 8820 PB - MDPI AN - OPUS4-53360 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Seher, Julia A1 - Fröba, M. T1 - Shape matters: The effect of particle morphology on the fast-charging performance of LiFePO4/C nanoparticle composite electrodes N2 - For the successful use of lithium-ion batteries in automotive applications, reliable availability of high storage capacity and very short recharging times are essential. In order to develop the perfect battery for a certain application, structure–property relationships of each active material must be fully understood. LiFePO4 is of great interest due to its fast-charging capability and high stability regarding its thermal resistance and chemical reactivity. The anisotropic lithium-ion diffusion through the LiFePO4 crystal structure indicates a strong dependence of the electrochemical performance of a nanostructured active material on particle morphology. In this paper, the relationship of the particle morphology and fast-charging capability of LiFePO4/C core/shell nanoparticles in half-cells was studied. For this purpose, a new multistep synthesis strategy was developed. It involves the combination of a solvothermal synthesis followed by an in situ polymer coating and thermal calcination step. Monodisperse rodlike LiFePO4 nanoparticles with comparable elongation along the b-axis (30–50 nm) and a varying aspect ratio c/a (2.4–6.9) were obtained. A strong correlation of the fast-charging capability with the aspect ratio c/a was observed. When using LiFePO4 nanoparticles with the smallest aspect ratio c/a, the best electrochemical performance was received regarding the specific capacity at high C-rates and the cycling stability. A reduction of the aspect ratio c/a by 30% (3.6 to 2.4) was found to enhance the charge capacity at 10 C up to an order of magnitude (7.4–73 mA h·g–1). KW - LiFePO4 KW - Schnellladung KW - Nanoparticles KW - Carbon KW - Chemical synthesis KW - Electrochemical cells KW - Materials PY - 2021 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-533004 DO - https://doi.org/10.1021/acsomega.1c03432 SN - 2470-1343 VL - 6 IS - 37 SP - 24062 EP - 24069 PB - American Chemical Society CY - Washington, DC AN - OPUS4-53300 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Schröpfer, Dirk A1 - Scharf-Wildenhain, R. A1 - Hälsig, A. A1 - Wandtke, Karsten A1 - Kromm, Arne A1 - Kannengießer, Thomas T1 - Process-related influences and correlations in wire arc additive manufacturing of high-strength steels N2 - High-strength fine-grained structural steels have great potential for weight-optimized, efficient structures in many modern steel applications. Further advances in efficiency can be achieved through additive manufacturing and bionic design. Commercial high-strength filler materials for wire arc additive manufacturing (WAAM) are already provided by the consumable producers. Today, application would be strictly limited due to absence of quantitative findings or any guidelines for the industry regarding welding-related stresses and component safety during manufacturing and service. Hence, process- and material-related influences and design-related restraint conditions associated with formation of residual stresses and cold cracking risk are investigated. The aim is the accessibility of special WAAM self-restraining cold cracking tests and easy applicable processing recommendations, enabling an economical, fit-for-purpose and crack-safe WAAM of high-strength steels. This first study focuses on determination of interactions between WAAM process parameters, resulting layer geometry, microstructure and residual stresses, analyzed via X-ray diffraction. Defined reference specimens are automated welded using a special WAAM solid wire (yield strength >820 MPa). Geometric properties can be specifically adjusted by wire feed and welding speed, but cannot be varied arbitrarily, since a high heat input causes local overheating, inadmissible changes of microstructure and mechanical properties, defects and comparable high tensile residual stresses. T2 - 22. Werkstofftechnischen Kolloquium der TU Chemnitz CY - Online meeting DA - 24.03.2021 KW - Residual stresses KW - Additive Manufacturing KW - High-strength steel PY - 2021 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-533300 DO - https://doi.org/10.1088/1757-899X/1147/1/012002 VL - 1147 SP - 012002 PB - IOP Publishing Ltd AN - OPUS4-53330 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Wittmar, J. A1 - Ohle, Corina A1 - Kunte, Hans-Jörg A1 - Brand, I. T1 - Effect of Ectoine on the Conformation and Hybridization of dsDNA in Monolayer Films: A Spectroelectrochemical Study N2 - Lack of long-time stability of dsDNA-based supramolecular assemblies is an important issue that hinders their applications. In this work, 20 base pairs long dsDNA fragments [(dCdG)20 65%] composed of 65% dCdG and 35% dAdT nucleotides were tethered via a thiol to the surface of a gold electrode. The selfassembled (dCdG)20 -65% monolayer was immersed in solutions containing ectoine, a compatible solute. Electrochemical results showed that these monolayers were stable for one month. In situ IR spectroscopy indicated that ectoine interacts weakly with the phosphate-ribose backbone, dehydrating the phosphate groups and stabilizing the A-DNA conformation. This structural reorganization led to a reorientation of nucleic acid base pairs and a local disruption of the double-helix structure. However, the conformation and orientation of the dsDNA fragment was stable in the KW - Ectoine KW - dsDAN monolayer KW - A-DNA conformation PY - 2021 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-533346 DO - https://doi.org/10.1002/celc.202100816 SN - 2196-0216 VL - 8 IS - 20 SP - 3844 EP - 3854 PB - Wiley-VCH GmbH AN - OPUS4-53334 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Friedrich, Sebastian A1 - Cappella, Brunero T1 - Friction and mechanical properties of AFM-scan-induced ripples in polymer films N2 - In the present paper, friction and mechanical properties of AFM-Scan-Induced ripple structures on films of polystyrene and poly-n-(butyl methacrylate) are investigated. Force volume measurements allow a quantitative analysis of the elastic moduli with nanometer resolution, showing a contrast in mechanical response between bundles and troughs. Additionally, analysis of the lateral cantilever deflection shows a clear correlation between friction and the sample topography. Those results support the theory of crack propagation and the formation of voids as a mechanism responsible for the formation of ripples. This paper also shows the limits of the presented measuring methods for soft, compliant, and small structures. KW - AFM KW - Polymer KW - Ripples KW - Mechanical properties KW - Friction PY - 2021 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-532772 DO - https://doi.org/10.3389/fmech.2021.672898 SN - 2297-3079 VL - 7 SP - 1 EP - 8 PB - Frontiers Media CY - Lausanne AN - OPUS4-53277 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Serrano Munoz, Itziar A1 - Evans, Alexander A1 - Mishurova, Tatiana A1 - Sprengel, Maximilian A1 - Pirling, T. A1 - Kromm, Arne A1 - Bruno, Giovanni T1 - The importance of subsurface residual stress in laser powder bed fusion IN718 N2 - The residual stress (RS) in laser powder bed fusion (LPBF) IN718 alloy samples produced using a 67°-rotation scan strategy is investigated via laboratory X-ray diffraction (XRD) and neutron diffraction (ND). The location dependence of the strain-free (d₀) lattice spacing in ND is evaluated using a grid array of coupons extracted from the far-edge of the investigated specimen. No compositional spatial variation is observed in the grid array. The calculated RS fields show considerable non-uniformity, significant stress gradients in the region from 0.6 to 2 mm below the surface, as well as subsurface maxima that cannot be accounted for via XRD. It is concluded that failure to determine such maxima would hamper a quantitative determination of RS fields by means of the stress balance method. KW - Laser powder bed fusion KW - Neutron and X-ray diffraction KW - Residual stress analysis KW - Strain-free lattice references KW - Stress balance PY - 2021 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-532707 DO - https://doi.org/10.1002/adem.202100895 SN - 1615-7508 SN - 1527-2648 VL - 24 IS - 6 SP - 1 EP - 7 PB - Wiley-VCH CY - Weinheim AN - OPUS4-53270 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 - Trogadas, P. A1 - Cho, J. I. S. A1 - Rasha, L. A1 - Lu, X. A1 - Kardjilov, N. A1 - Markötter, Henning A1 - Manke, I. A1 - Shearing, P. R. A1 - Brett, D. J. L. A1 - Coppens, M. O. T1 - A nature-inspired solution for water management in flow fields for electrochemical devices N2 - A systematic, nature-inspired chemical engineering approach is employed to solve the issue of flooding in electrochemical devices. The mechanism of passive water transport utilized by lizards living in arid environments is leveraged to design flow-fields with a microchannel structure on their surface, through which capillary pressure rapidly removes the water generated in the electrochemical device. This water management strategy is implemented in proton exchange membrane fuel cells (PEMFCs) with a lunginspired flow-field, which ensures uniform distribution of reactants across the catalyst layer. Jointly, this nature-inspired approach results in flood-free, stable operation at 100% RH and a B60% increase in current (B1.9 A cm-2) and peak power density (B650 mW cm−2) compared to current PEMFCs with a flood-prone, serpentine flow-field (B0.8 A cm-2 and 280 mW cm-2, respectively). This significant advance allows for PEMFC operation at fully humidified conditions. KW - Neutron imaging KW - X-ray tomography KW - Fuel cell PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-596662 DO - https://doi.org/10.1039/d3ee03666a VL - 17 SP - 2007 EP - 2017 PB - Royal Society of Chemistry (RSC) AN - OPUS4-59666 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kapoor, M. A1 - Overgaard Christensen, Ch. A1 - Wittrup Schmidt, J. A1 - Dalsgaard Sørensen, J. A1 - Thöns, Sebastian T1 - Decision analytic approach for the reclassification of concrete bridges by using elastic limit information from proof loading N2 - Reclassification of bridges, i.e., a change in load rating, using reliability-based methods and a direct update with proof load information has been presented by many authors. However, bridge reclassification has hardly been studied from a decision analytic perspective, i.e., with quantification of the risks and benefits of different classification choices, and the expected benefit gain from proof loading. We derive, explain and exemplify a decision analytic approach for bridge reclassification along with models for (1) elastic and ultimate capacity and their adaptation with proof load information, (2) proof load information with classification outcomes accounting for target reliabilities and, (3) utilities including socio-economic benefits from reclassification. The approach and models are exemplified with a case study based on reclassification of bridges with a low existing classification. Decision rules, for practical use by a highway authority to find the optimal classification, are identified and documented based on: (1) the measurement of the capacity at elastic limit by proof loading, (2) the bridge reclassification benefits, and, (3) the required annual reliability level. From a Value of Information analysis, it is concluded that the proof load information is highly valuable for reclassification in cases of high socio-economic benefits and high reliability requirements. KW - Proof loading KW - Structural reliability KW - Value of information KW - Decision analysis PY - 2023 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-596845 DO - https://doi.org/10.1016/j.ress.2022.109049 SN - 0951-8320/ VL - 232 SP - 1 EP - 16 PB - Elsevier Ltd. AN - OPUS4-59684 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kricheldorf, H. A1 - Weidner, Steffen A1 - Meyer, A. T1 - Syntheses of Polyglycolide via Polycondensation: A Reinvestigation N2 - The Na salt of chloroacetic acid is condensed in suspension. Furthermore,glycolic acid is condensed in bulk or in concentrated solution by means of SnCl2 or 4-toluene sulfonic acid (TSA) as catalysts. The temperatures are varied from 160 to 200°C and the time from 1 to 5 days. Low molar mass cyclic poly(glycolic acid) (PGA) is detected by means of matrix-assisted laser desorption ionization time-of-flight (MALDI TOF) mass spectrometry in most PGAs. A predominance of certain cycles having an even number of repeat units is observed suggesting a thermodynamically favored formation of extended-ring crystals. Extremely high melting temperatures (up to 237.5°C)and high melting enthalpies are found for polycondensations with TSA in 1,2-dichlorobenzene. KW - MALDI TOF MS KW - Polycondensation KW - Polyglycolide KW - Cyclization PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-596856 DO - https://doi.org/10.1002/macp.202300397 IS - 2300397 SP - 1 EP - 7 PB - Wiley VHC-Verlag AN - OPUS4-59685 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Nxumalo, T. A1 - Akhdhar, A. A1 - Mueller, V. A1 - Simon, Fabian A1 - von der Au, Marcus A1 - Cossmer, Antje A1 - Pfeifer, Jens A1 - Krupp, E. A1 - Meermann, Björn A1 - Kindness, A. A1 - Feldmann, J. T1 - EOF and target PFAS analysis in surface waters affected by sewage treatment effluents in Berlin, Germany N2 - Per- and polyfuoroalkyl substances (PFAS) are emerging organic pollutants and can occur in surface and groundwater. To identify the degree of pollution in surface water with PFAS, often targeted HPLC–ESI–MS/MS has been employed in which commonly 30–40 compounds are analyzed. However, other PFAS and organofuorines remain undetected. We sampled surface water of the river Spree and the Teltow Canal in Berlin, Germany, which are afected by the efuent discharge of wastewater treatment plants. Here, we employed high-resolution continuum source graphite furnace molecular absorption spectrometry (HR-CS-GFMAS) for measuring extractable organofuorines (EOF) and compared in a mass balance approach the total fuorine to the identifed and quantifed PFAS from the targeted analysis. The analysis highlights that the EOF are in the range expected for an urban river system (Winchell et al. in Sci Total Environ 774, 2021). However, downstream of an efuent discharge, the EOF increased by one order of magnitude, e.g., 40.3 to 574 ng F L−1, along the Teltow Canal. From our target analytes, mostly short-chained perfuorinated carboxylic acids and sulfonates occur in the water, which however makes up less than 10% of the EOF. The increase in EOF in the Teltow Canal correlates well with the increase of perfuorohexanoic acid (PFHxA), indicating that PFHxA is characteristic for the discharged EOF but not responsible for the increase. Hence, it points to PFHxA precursor discharge. The study highlights that EOF screening using HR-CS-GFMAS is necessary to identify the full scale of pollution with regard to PFAS and other organofuorines such as pharmaceutical compounds from the efuent of WWTPs. KW - PFAS KW - WWTP KW - GF-MAS PY - 2023 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-580341 DO - https://doi.org/10.1007/s00216-022-04500-x VL - 415 SP - 1195 EP - 1204 PB - Springer AN - OPUS4-58034 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Hendriks, L. A1 - Brunjes, R. A1 - Taskula, S. A1 - Kocic, J. A1 - Hattendorf, B. A1 - Bland, G. A1 - Lowry, G. A1 - Bolea-Fernandez, E. A1 - Vanhaecke, F. A1 - Wang, J. A1 - Baalousha, M. A1 - von der Au, Marcus A1 - Meermann, Björn A1 - Holbrook, T. A1 - Wagner, S. A1 - Harycki, S. A1 - Gundlach-Graham, A. A1 - von der Kammer, F. T1 - Results of an interlaboratory comparison for characterization of Pt nanoparticles using single-particle ICP-TOFMS N2 - This study describes an interlaboratory comparison (ILC) among nine (9) laboratories to evaluate and validate the standard operation procedure (SOP) for single-particle (sp) ICP-TOFMS developed within the context of the Horizon 2020 project ACEnano. The ILC was based on the characterization of two different Pt nanoparticle (NP) suspensions in terms of particle mass, particle number concentration, and isotopic composition. The two Pt NP suspensions were measured using icpTOF instruments (TOFWERK AG, Switzerland). Two Pt NP samples were characterized and mass equivalent spherical sizes (MESSs) of 40.4 ± 7 nm and 58.8 ± 8 nm were obtained, respectively. MESSs showed <16% relative standard deviation (RSD) among all participating labs and <4% RSD after exclusion of the two outliers. A good agreement was achieved between the different participating laboratories regarding particle mass, but the particle number concentration results were more scattered, with <53% RSD among all laboratories, which is consistent with results from previous ILC studies conducted using ICP-MS instrumentation equipped with a sequential mass spectrometer. Additionally, the capabilities of sp-ICP-TOFMS to determine masses on a particle basis are discussed with respect to the potential for particle density determination. Finally, because quasi-simultaneous multi-isotope and multielement determinations are a strength of ICP-TOFMS instrumentation, the precision and trueness of isotope ratio determinations were assessed. The average of 1000 measured particles yielded a precision of below ±1% for intensity ratios of the most abundant Pt isotopes, i.e. 194Pt and 195Pt, while the accuracy of isotope ratios with the lower abundant isotopes was limited by counting statistics. KW - ILC KW - spICP-MS KW - PtNP KW - Nanopartikel PY - 2023 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-580353 DO - https://doi.org/10.1039/d3nr00435j SN - 2040-3364 VL - 15 IS - 26 SP - 11268 EP - 11279 PB - Royal Society of Chemistry (RSC) AN - OPUS4-58035 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Solberg, S. B. B. A1 - Zimmermann, P. A1 - Wilhelmsen, Ø. A1 - Bock, Robert A1 - Burheim, O. S. T1 - Analytical treatment of ion-exchange permselectivity and transport number measurements for high accuracy N2 - We analyse electromotive force measurements of concentration cells using non-equilibrium thermodynamics, and determine the transference coefficients of ion-exchange membranes in aqueous KCl solutions. By taking advantage of the analytical expression for the permselectivity, we extract transport coefficients with high accuracy. The transport number of K+ and the transference coefficient of water in the Selemion CMVN cationexchange membrane are found to be 100𝑡K+ = 99.59 ± 0.56 and 𝑡𝑤 = 3.69 ± 0.40 respectively, while for the Selemion AMVN anion-exchange membrane they are 100𝑡Cl− = 100.21 ± 0.37 and 𝑡𝑤 = −3.75 ± 0.27. These results suggest that the membranes are perfectly selective to the target ion, and that each ion carries 3-4 water molecules through the membrane, which reduces the membrane permselectivity. In these concentration cells, the electrical potential contribution of the membrane alone was more easily isolated with bare Ag/AgCl electrodes without reference solutions and liquid junction plugs. Additionally, we find a large contribution to the measured concentration cell voltage from concentration gradients across the porous plug of the reference electrode, which cannot be explained by Henderson’s equation alone. For most of the concentration range, the transport number of the porous plug is determined to be 100𝑡K+ = 49.43 ± 0.78 with negligible water transport, similar to literature values for bulk electrolyte. In dilute electrolyte solutions with concentrations below 0.1 mol kg−1, the plug shows anomalous behaviour consistent with an increase in K+ selectivity and water co-transport. KW - Ion-exchange membranes KW - Electrodialysis KW - Non-equilibrium thermodynamics KW - Electroosmosis KW - Transport number PY - 2023 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-580654 DO - https://doi.org/10.1016/j.memsci.2023.121904 SN - 1873-3123 VL - 2023 IS - 685 PB - Elsevier CY - New York, NY [u.a.] AN - OPUS4-58065 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - El-Sari, B. A1 - Biegler, M. A1 - Rethmeier, Michael T1 - Investigation of the LME Susceptibility of Dual Phase Steel with Different Zinc Coatings N2 - The application of anti-corrosion coated, high-strength steels in the automotive industry has increased in recent years. In combination with various zinc-based surface coatings, liquid metal embrittlement cracking can be observed in some of these materials. A high-quality, crack-free spot-welded joint is essential to realize the lightweight potential of the materials. In this work, the LME susceptibility of different coatings, which will be determined by the crack length and the occurrence rate, will be investigated using a welding under external load setup. The uncoated specimens did not show any LME. EG, GI and GA showed significantly less LME than ZM coatings. The latter coatings showed much larger crack lengths than the EG, GI and GA coatings. Furthermore, two mechanisms regarding the LME occurrence rate were observed: the occurrence of LME in zinc–magnesium coatings was theorized to be driven by the material properties of the coatings, whereas the occurrence of LME at EG, GI and GA samples was forced mainly by the application of the external tensile load. In the experimental setup of this work, the materials were exposed to unusually high mechanical loads (up to 80% of their yield strength) to evoke LME cracks. KW - Widerstandspunktschweißen KW - Hochfester Stahl KW - Liquid Metal Embrittlement KW - Flüssigmetallinduzierte Rissbildung KW - Zink KW - AHSS PY - 2023 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-580428 DO - https://doi.org/10.3390/met13050890 VL - 13 IS - 5 SP - 1 EP - 11 PB - MDPI AN - OPUS4-58042 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Lu, Xin A1 - Thomas, P. T1 - Phase Error Evaluation via Differentiation and Cross-Multiplication Demodulation in Phase-Sensitive Optical Time-Domain Reflectometry N2 - Phase-sensitive optical time-domain reflectometry (jOTDR) is a technology for distributed vibration sensing, where vibration amplitudes are determined by recovering the phase of the backscattered light. Measurement noise induces phase errors, which degrades sensing performance. The phase errors, using a differentiation and cross-multiplication (DCM) algorithm, are investigated theoretically and experimentally in a jOTDR system based on a phase retrieval configuration consisting of an imbalanced Mach–Zehnder interferometer (IMZI) and a 3 x 3 coupler. Analysis shows that phase error is highly dependent on the AC component of the obtained signal, essentially being inversely proportional to the product of the power of the light backscattered from two locations. An analytical expression was derived to estimate the phase error and was confirmed by experiment. When applied to the same measurement data, the error is found to be slightly smaller than that obtained using in-phase/quadrature (I/Q) demodulation. The error, however, increases for longer measurement times. KW - Distributed fiber sensing KW - Phase-sensitive optical time-domain reflectometry KW - Phase error PY - 2023 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-580501 UR - https://www.mdpi.com/2304-6732/10/5/514 DO - https://doi.org/10.3390/photonics10050514 SN - 2304-6732 VL - 10 IS - 5 SP - 1 EP - 14 PB - MDPI CY - Basel AN - OPUS4-58050 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Mouiya, M. A1 - Martynyuk, M. A1 - Kupsch, Andreas A1 - Laquai, R. A1 - Müller, Bernd R. A1 - Doyen, N.T. A1 - Tamraoui, Y. A1 - Serrano Munoz, Itziar A1 - Huger, M. A1 - Kachanov, M. A1 - Bruno, Giovanni T1 - The stress–strain behavior of refractory microcracked aluminum titanate: The effect of zigzag microcracks and its modeling N2 - The stress–strain behavior of ceramics, such as aluminum titanate, has certain features that are unusual for brittle materials—in particular, a substantial nonlinearity under uniaxial tension, and load–unload hysteresis caused by the sharp increase of the incremental stiffness at the beginning of unloading. These features are observed experimentally and are attributed to microcracking. Here we compare different degrees of stress–strain nonlinearity of aluminum titanate materials and quantitatively model them. We use advanced mechanical testing to observe the mechanical response at room and high temperature; electron microscopy, and X-ray refraction radiography to observe the microstructural changes. Experiments show that two types of microcracks can be distinguished: (i) microcracks induced by cooling from the sintering temperature (due to heterogeneity and anisotropy of thermal expansion), with typical sizes of the order of grain size, and (ii) much larger microcracks generated by the mechanical loading. The two microcrack types produce different effects on the stress–strain curves. Such microcracks and the features of the stress–strain behavior depend on the density of the cooling-induced microcracks and on the distribution of grain sizes. They are modeled analytically and numerically. KW - Hystersis KW - Nonlinear stress-strain curve KW - Refractory KW - Stiffness KW - X-ray refraction PY - 2023 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-580517 DO - https://doi.org/10.1111/jace.19325 SN - 1551-2916 VL - 106 SP - 6995 EP - 7008 PB - Wiley-Blackwell CY - Oxford [u.a.] AN - OPUS4-58051 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Weidner, Steffen A1 - Meyer, A. A1 - Kricheldorf, H. T1 - Cyclic polyglycolides via ring-expansion polymerization with cyclic tin catalysts N2 - Glycolide was polymerized in bulk with two cyclic catalysts − 2,2-dibutyl-2-stanna-1,3-dithiolane (DSTL) and 2-stanna-1,3-dioxa-4,5,6,7-dibenzepane (SnBiph). The monomer/initiator ratio, temperature (140 – 180 °C) and time (1–––4 days) were varied. The MALDI TOF mass spectra exclusively displayed peaks of cyclic polyglycolide (PGA) and revealed an unusual “saw-tooth pattern” in the mass range below m/z 2 500 suggesting formation of extended ring crystallites. The DSC measurements indicated increasing crystallinity with higher temperature and longer time, and after annealing for 4 d at 160 °C a hitherto unknown and unexpected glass transition was found in the temperature range of 170–185 °C. Linear PGAs prepared by means of metal alkoxides under identical conditions did not show the afore-mentioned features of the cyclic PGAs, neither in the mass spectra nor in the DSC measurements. All PGAs were also characterized by SAXS measurements, which revealed relatively small L-values suggesting formation of thin crystallites in all cases with little influence of the reaction conditions. KW - Polyglycolide KW - MALDI-TOF MS KW - Ring-expansion polymerization KW - Crystals PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-595541 DO - https://doi.org/10.1016/j.eurpolymj.2024.112811 SN - 0014-3057 VL - 207 SP - 1 EP - 9 PB - Elsevier Ltd. AN - OPUS4-59554 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Pfennig, Anja A1 - Wolf, Marcus A1 - Kranzmann, Axel T1 - Corrosion and corrosion fatigue of steels in downhole CCS environment - A summary N2 - Static immersion tests of potential injection pipe steels 42CrMo4, X20Cr13, X46Cr13, X35CrMo4, and X5CrNiCuNb16-4 at T = 60 °C and ambient pressure, as well as p = 100 bar were performed for 700–8000 h in a CO₂-saturated synthetic aquifer environment similar to CCS sites in the Northern German Basin (NGB). Corrosion rates at 100 bar are generally lower than at ambient pressure. The main corrosion products are FeCO₃ and FeOOH with surface and local corrosion phenomena directly related to the alloy composition and microstructure. The appropriate heat treatment enhances corrosion resistance. The lifetime reduction of X46Cr13, X5CrNiCuNb16-4, and duplex stainless steel X2CrNiMoN22-5-3 in a CCS environment is demonstrated in the in situ corrosion fatigue CF experiments (axial push-pull and rotation bending load, 60 °C, brine: Stuttgart Aquifer and NGB, flowing CO₂: 30 L/h, +/- applied potential). Insulating the test setup is necessary to gain reliable data. S-N plots, micrographic-, phase-, fractographic-, and surface analysis prove that the life expectancy of X2CrNiMoN22-5-3 in the axial cyclic load to failure is clearly related to the surface finish, applied stress amplitude, and stress mode. The horizontal grain attack within corrosion pit cavities, multiple fatigue cracks, and preferable deterioration of austenitic phase mainly cause fatigue failure. The CF life range increases significantly when a protective potential is applied. KW - Steel KW - High alloyed steel KW - Corrosion KW - Corrosion fatigue KW - Carbon capture and storage PY - 2021 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-531391 DO - https://doi.org/10.3390/pr9040594 SN - 2227-9717 VL - 9 IS - 4 SP - 1 EP - 33 PB - MDPI CY - Basel AN - OPUS4-53139 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Tokarski, T. A1 - Nolze, Gert A1 - Winkelmann, A. A1 - Rychlowski, L. A1 - Bala, P. A1 - Cios, G. T1 - Transmission Kikuchi diffraction: The impact of the signal-to-noise ratio N2 - Signal optimization for transmission Kikuchi diffraction (TKD) measurements in the scanning electron microscope is investigated by a comparison of different sample holder designs. An optimized design is presented, which uses a metal shield to efficiently trap the electron beam after transmission through the sample. For comparison, a second holder configuration allows a significant number of the transmitted electrons to scatter back from the surface of the sample holder onto the diffraction camera screen. It is shown that the secondary interaction with the sample holder leads to a significant increase in the background level, as well as to additional noise in the final Kikuchi diffraction signal. The clean TKD signal of the optimized holder design with reduced background scattering makes it possible to use small signal changes in the range of 2% of the camera full dynamic range. As is shown by an analysis of the power spectrum, the signal-to-noise ratio in the processed Kikuchi diffraction patterns is improved by an order of magnitude. As a result, the optimized design allows an increase in pattern signal to noise ratio which may lead to increase in measurement speed and indexing reliability. KW - EBSD KW - SEM KW - Transmission Kikuchi diffraction KW - Sample holder PY - 2021 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-531743 DO - https://doi.org/10.1016/j.ultramic.2021.113372 SN - 0304-3991 SN - 1879-2723 VL - 230 SP - 1 EP - 8 PB - Elsevier CY - Amsterdam AN - OPUS4-53174 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -