TY - JOUR A1 - Kiefer, P. A1 - Deubener, J. A1 - Müller, Ralf A1 - Behrens, H. T1 - Statistical analysis of propagation rates of indentation-induced radial cracks N2 - Due to the stochastic nature of crack nucleation by Vickers indentation, a statistical analysis of propagation rates of 185 radial cracks was performed. Crack growth was observed directly using a video camera with high Image acquisition rate. It is found that propagation rates are controlled by the environmental reactions at the crack-tip shortly after their initiation (< 1 s). Calibration of the stress intensity KI showed that the residual stress factor χ and the exponent n of the equation KI==χPc−n (with P==load and c==crack length) are broadly distributed among the 185 analyzed cracks, ranging from 10−16 to 104 and from 0.1 to 5, respectively. For the most frequent crack, the equation KI==0.052Pc−1.47 holds. The results show that correlations of indentation-induced crack length to stress intensity necessitate the use of statistical significant data that are calibrated by the environmental reactions at the crack-tip. KW - Stress intensity factor KW - Vickers indentation KW - Subcritical crack growth KW - Soda-lime-silica glass PY - 2019 DO - https://doi.org/10.1016/j.jnoncrysol.2019.119739 VL - 527 SP - 119739 PB - Elsevier B.V. AN - OPUS4-50393 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Müller, I. A1 - Moll, J. A1 - Kexel, C. A1 - Schubert, L. A1 - Tschöke, K. A1 - Prager, Jens A1 - Lugovtsova, Yevgeniya A1 - Bach, M. A1 - Vogt, T. T1 - SHM using Guided Waves – Recent Activities and Advances in Germany N2 - Issues that prevent Structural Health Monitoring (SHM) based on Guided Waves (GW) from being a part of today’s monitoring solutions in industry are not all obvious to the scientific community. To uncover and overcome these issues, scientists working on SHM and GW problems joined in an expert committee under the patronage of the German Society for Non-Destructive Testing. An initiated online survey among more than 700 experts and users reveals the hurdles hindering the practical application of GWbased SHM. Firstly, methods for proof of reliability of SHM approaches are missing. Secondly, detailed understanding of phenomenological described wave-damage interactions is needed. Additionally, there are significant unsolved implementation issues and unsolved problems of signal processing including handling of environmental influences. To enable substantial proof of reliability without unaffordable experimental effort also efficient simulation tools including realistic damage interaction are needed, enabling the joint use of experimental and simulated data to predict the capabilities of the Monitoring system. Considering these issues, the committee focusses on simulation, signal processing, as well as probability of detection and standardization. In the presented work, recent activities of the expert committee starting with survey results are summarized. An open access data basis of life-like measurements is presented to allow testing and comparison of signal processing and simulation algorithms. Finally, a strategy for efficient proof of reliability increasing the acceptance of SHM in industry and for successful Integration of SHM into real-world engineering structures is proposed. T2 - The 12th International Workshop on Structural Health Monitoring (IWSHM) CY - Stanford, California, USA DA - 10.09.2019 KW - Structural Health Monitoring KW - Ultrasonic Guided Waves KW - Non-Destructive Testing KW - Survey KW - Probability of Detection KW - Reliability PY - 2019 SP - 1 EP - 10 AN - OPUS4-49232 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Liens, A. A1 - Reveron, H. A1 - Douillard, T. A1 - Blanchard, N. A1 - Lughi, V. A1 - Sergo, V. A1 - Laquai, René A1 - Müller, Bernd R. A1 - Bruno, Giovanni A1 - Schomer, S. A1 - Fürderer, T. A1 - Adolfsson, E. A1 - Courtois, N. A1 - Swain, M. A1 - Chevalier, J. T1 - Phase transformation induces plasticity with negligible damage in ceria-stabilized zirconia-based ceramics N2 - Ceramics and their composites are in general brittle materials because they are predominantly made up of ionic and covalent bonds that avoid dislocation motion at room temperature. However, a remarkable ductile behavior has been observed on newly developed 11 mol.% ceria-stabilized zirconia (11Ce-TZP) composite containing fine alumina (8 vol.% Al2O3) and elongated strontium hexa-aluminate (8 vol.% SrAl12O19) grains. The as-synthesized composite also has shown full resistance to Low Temperature Degradation (LTD), relatively high strength and exceptionally high Weibull modulus, allowing its use in a broader range of biomedical applications. In this study, to deepen the understanding of plastic deformation in Ce-TZP based composites that could soon be used for manufacturing dental implants, different mechanical tests were applied on the material, followed by complete microstructural characterization. Distinct from pure Ce-TZP material or other zirconia-based ceramics developed in the past, the material here studied can be permanently strained without affecting the Young modulus, indicating that the ductile response of tested samples cannot be associated to damage occurrence. This ductility is related to the stress-induced tetragonal to monoclinic (t-m) zirconia phase transformation, analogue to Transformation-Induced Plasticity (TRIP) steels, where retained austenite is transformed to martensite. The aim of this study is to corroborate if the observed plasticity can be associated exclusively to the zirconia t-m phase transformation, or also to microcraking induced by the transformation. The t-m transformed-zones produced after bending and biaxial tests were examined by X-ray refraction and SEM/TEM coupled with Raman. The results revealed that the observed elastic-plastic behavior occurs without extensive microcracking, confirming a purely elastic-plastic behavior driven by the phase transformation (absence of damage). KW - Zirconia KW - Ceria KW - Ceramic matrix composite KW - Plasticity KW - Phase transformation KW - X-Ray Refraction PY - 2020 UR - http://www.sciencedirect.com/science/article/pii/S1359645419307177 DO - https://doi.org/10.1016/j.actamat.2019.10.046 SN - 1359-6454 VL - 183 SP - 261 EP - 273 PB - Elsevier Ltd. AN - OPUS4-49740 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Laquai, René A1 - Müller, Bernd R. A1 - Kasperovich, G. A1 - Requena, G. A1 - Haubrich, J. A1 - Bruno, Giovanni T1 - Classification of defect types in SLM Ti-6Al-V4 by X-ray refraction topography N2 - Porosity in additively manufactured materials, such as laser powder bed fusion Ti-Al6-V4, can play an important role in their mechanical performance. Not only the total porosity but also the shape/morphology of the individual pores need to be considered. Therefore, it is necessary to determine the distributions of different defect types (especially fusing defects and keyhole pores) and their dependence on process parameters. We show that synchrotron X-ray refraction radiography allows analysis of large samples (up to several millimeters) without compromising the detectability of submicrometer defects. Correspondingly, a classification tool is introduced that is able to quantitatively distinguish defects such as keyhole pores and binding defects with a confidence level of 94 %, even when the shape cannot be discerned because of limited spatial resolution. KW - Additive manufacturing KW - Selective laser melting KW - X-ray refraction KW - Microscopy KW - Porosity KW - X-ray computed tomography KW - BAMline KW - Synchrotron Radiation PY - 2020 DO - https://doi.org/10.1520/MPC20190080 SN - 2379-1365 VL - 9 IS - 1 SP - 82 EP - 93 PB - ASTM International CY - West Conshohocken, PA AN - OPUS4-50470 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Cant, D. J. H. A1 - Minelli, C. A1 - Sparnacci, K. A1 - Müller, Anja A1 - Kalbe, H. A1 - Stoger-Pollach, M. A1 - Unger, Wolfgang A1 - Werner, W. S. M. A1 - Shard, A. G. T1 - Surface-Energy Control and Characterization of Nanoparticle Coatings N2 - Accurate and reproducible measurement of the structure and properties of high-value nanoparticles is extremely important for their commercialization. A significant proportion of engineered nanoparticle systems consist of some form of nominally core-shell structure, whether by design or unintentionally. Often, these do not form an ideal core-shell structure, with typical deviations including polydispersity of the core or shell, uneven or incomplete shells, noncentral cores, and others. Such systems may be created with or without intent, and in either case an understanding of the conditions for formation of such particles is desirable. Precise determination of the structure, composition, size, and shell thickness of such particles can prove challenging without the use of a suitable range of characterization techniques. Here, the authors present two such polymer core-shell nanoparticle systems, consisting of polytetrafluoroethylene cores coated with a range of thicknesses of either polymethylmethacrylate or polystyrene. By consideration of surface energy, it is shown that these particles are expected to possess distinctly differing coating structures, with the polystyrene coating being incomplete. A comprehensive characterization of these systems is demonstrated, using a selection of complementary techniques including scanning electron microscopy, scanning transmission electron microscopy, thermogravimetric analysis, dynamic light scattering, differential centrifugal sedimentation, and X-ray photoelectron spectroscopy. By combining the results provided by these techniques, it is possible to achieve superior characterization and understanding of the particle structure than could be obtained by considering results separately. KW - Nanoparticles KW - Core-shell KW - XPS KW - Size KW - Thickness KW - Damage PY - 2020 DO - https://doi.org/10.1021/acs.jpcc.0c02161 VL - 124 IS - 20 SP - 11200 EP - 11211 PB - ACS CY - Washington DC AN - OPUS4-50899 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Laquai, René A1 - Müller, Bernd R. A1 - Kasperovich, G. A1 - Haubrich, J. A1 - Requena, G. A1 - Bruno, Giovanni T1 - X-ray refraction distinguishes unprocessed powder from empty pores in selective laser melting Ti-6Al-4V N2 - For the first time, X-ray refraction techniques are proven for the identification of void formation in Ti-6Al-4V parts produced by selective laser melting. The topology and volume fraction of pores are measured in samples produced with different laser energy density. Unique X-ray refraction methods identify different kinds of defects, characteristic to the regions below and above the Optimum laser energy density, namely unprocessed powder (unmolten powder particles, balling effect, and Fusion defects) from empty keyhole pores. Furthermore, it is possible to detect small inhomogeneities (voids or cracks) with sizes below the spatial resolution of optical microscopy and X-ray computed tomography. KW - Additive manufacturing KW - X-ray refraction KW - Microscopy KW - X-ray computed tomography KW - Porosity PY - 2018 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-434041 DO - https://doi.org/10.1080/21663831.2017.1409288 SN - 2166-3831 VL - 6 IS - 2 SP - 130 EP - 135 PB - Taylor & Francis Group CY - London, UK AN - OPUS4-43404 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Laquai, René A1 - Müller, Bernd R. A1 - Schneider, J. A1 - Kupsch, Andreas A1 - Bruno, Giovanni T1 - Using SXRR to Probe the Nature of Discontinuities in SLM Additive Manufactured Inconel 718 Specimens N2 - The utilization of additive manufacturing (AM) to fabricate robust structural components relies on understanding the nature of internal anomalies or discontinuities, which can compromise the structural integrity. While some discontinuities in AM microstructures stem from similar mechanisms as observed in more traditional processes such as casting, others are unique to the AM process. Discontinuities in AM are challenging to detect, due to their submicron size and orientation dependency. Toward the goal of improving structural integrity, minimizing discontinuities in an AM build requires an understanding of the mechanisms of formation to mitigate their occurrence. This study utilizes various techniques to evaluate the shape, size, nature and distribution of discontinuities in AM Inconel 718, in a non-hot isostatic pressed (HIPed) as-built, non-HIPed and direct age, and HIPed with two step age samples. Non-destructive synchrotron radiation refraction and transmission radiography (SXRR) provides additional information beyond that obtained with destructive optical microscopy. SXRR was able to distinguish between voids, cracks and lack of melt in, due to its sensitivity to the orientation of the discontinuity. KW - Additive manufacturing KW - X-ray refraction radiography KW - INCONEL 718 KW - Selective laser melting PY - 2020 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-509836 DO - https://doi.org/10.1007/s11661-020-05847-5 SN - 1543-1940 VL - 51 IS - 8 SP - 4146 EP - 4157 PB - Springer AN - OPUS4-50983 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Cant, D. J. H. A1 - Müller, Anja A1 - Clifford, C. A. A1 - Unger, Wolfgang A1 - Shard, A. G. T1 - Summary of ISO/TC 201 Technical Report 23173—Surface chemical analysis—Electron spectroscopies—Measurement of the thickness and composition of nanoparticle coatings N2 - ISO Technical Report 23173 describes methods by which electron spectroscopies, including X-ray photoelectron spectroscopy (XPS), Auger electron spectroscopy (AES) and synchrotron techniques, can be employed to calculate the Coating thicknesses and compositions of nanoparticles. The document has been developed to review and outline the current state-of-the-art for such measurements. Such analyses of core–shell nanoparticles are common within the literature, however the methods employed are varied; the relative advantages and disadvantages of These methods, and the optimal usage of each may not be clear to the general analyst. ISO Technical Report 23173 aims to clarify the methods that are available, describe them in clear terms, exhibit examples of their use, and highlight potential issues users may face. The information provided should allow analysts of electron spectroscopy data to make clear choices regarding the appropriate analysis of electron spectroscopy data from coated nanoparticle systems and provide a basis for understanding and comparing results from different methods and systems. KW - Electron spectroscopy KW - Core-shell KW - Nanoparticles KW - ISO 23173 KW - XPS KW - Thickness KW - Composition PY - 2021 DO - https://doi.org/10.1002/sia.6987 SN - 0142-2421 VL - 53 IS - 10 SP - 893 EP - 899 PB - John Wiley & Sons Ltd AN - OPUS4-52976 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Brüngel, R. A1 - Rückert, J. A1 - Müller, P. A1 - Babick, F. A1 - Friedrich, C. M. A1 - Ghanem, A. A1 - Hodoroaba, Vasile-Dan A1 - Mech, A. A1 - Weigel, S. A1 - Wohlleben, W. A1 - Rauscher, H. T1 - NanoDefiner Framework and e-Tool Revisited According to the European Commission’s Nanomaterial Definition 2022/C 229/01 N2 - The new recommended definition of a nanomaterial, 2022/C 229/01, adopted by the European Commission in 2022, will have a considerable impact on European Union legislation addressing chemicals, and therefore tools to implement this new definition are urgently needed. The updated NanoDefiner framework and its e-tool implementation presented here are such instruments, which help stakeholders to find out in a straightforward way whether a material is a nanomaterial or not. They are two major outcomes of the NanoDefine project, which is explicitly referred to in the new definition. This work revisits the framework and e-tool, and elaborates necessary adjustments to make these outcomes applicable for the updated recommendation. A broad set of case studies on representative materials confirms the validity of these adjustments. To further foster the sustainability and applicability of the framework and e-tool, measures for the FAIRification of expert knowledge within the e-tool’s knowledge base are elaborated as well. The updated framework and e-tool are now ready to be used in line with the updated recommendation. The presented approach may serve as an example for reviewing existing guidance and tools developed for the previous definition 2011/696/EU, particularly those adopting NanoDefine project outcomes. KW - Nanomaterial definition KW - Nanomaterial categorisation KW - Nanomaterial regulation KW - Nanomaterial legislation KW - Decision support KW - FAIRification PY - 2023 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-571618 DO - https://doi.org/10.3390/nano13060990 SN - 2079-4991 VL - 13 IS - 6 - Special Issue "Identification and Quantification of Nanomaterials" SP - 1 EP - 16 PB - MDPI CY - Basel, CH AN - OPUS4-57161 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Baer, D. R. A1 - Cant, D. J. H. A1 - Castner, D. G. A1 - Ceccone, G. A1 - Engelhard, M. H. A1 - Karakoti, A. S. A1 - Müller, Anja ED - Hodoroaba, Vasile-Dan ED - Unger, Wolfgang ED - Shard, A. G. T1 - Preparation of nanoparticles for surface analysis N2 - A variety of methods used to prepare nano-objects for surface analysis are described along with information about when they might be best applied. Intrinsic properties of NPs which complicate their characterization and need to be considered when planning for surface or other analyses of NPs are identified, including challenges associated with reproducible synthesis and functionalization of the particles as well as their dynamic nature. The relevant information about the sample preparation processes, along with analysis details and data that need to be added to the collection of material provenance information is identified. Examples of protocols that have been successfully used for preparation of nano-objects for surface analysis are included in an annex. KW - Sample preparation KW - Nanoparticles KW - Surface chemistry KW - XPS KW - Dynamic behavior KW - Nano-object KW - Surface analysis PY - 2020 SN - 978-0-12-814182-3 DO - https://doi.org/10.1016/B978-0-12-814182-3.00018-3 SP - 295 EP - 347 PB - Elsevier CY - Amsterdam AN - OPUS4-50186 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Bramke, K. A1 - Müller, U. A1 - McMahon, Dino Peter A1 - Rolff, J. T1 - Exposure of Larvae of the Solitary Bee Osmia bicornis to the Honey Bee Pathogen Nosema ceranae Aects Life History N2 - Wild bees are important pollinators of wild plants and agricultural crops and they are threatened by several environmental stressors including emerging pathogens. Honey bees have been suggested as a potential source of pathogen spillover. One prevalent pathogen that has recently emerged as a honey bee disease is the microsporidian Nosema ceranae. While the impacts of N. ceranae in honey bees are well documented, virtually nothing is known about its effects in solitary wild bees. The solitary mason bee Osmia bicornis is a common pollinator in orchards and amenable to Commercial management. Here, we experimentally exposed larvae of O. bicornis to food contaminated with N. ceranae and document spore presence during larval development. We measured mortality, growth parameters, and timing of pupation in a semi-field experiment. Hatched individuals were assessed for physiological state including fat body mass, wing muscle mass, and body size. We recorded higher mortality in the viable-spore-exposed group but could only detect a low number of Spores among the individuals of this treatment. Viable-spore-treated individuals with higher head capsule width had a delayed pupation start. No impact on the physiological status could be detected in hatched imagines. Although we did not find overt evidence of O. bicornis infection, our findings indicate that exposure of larvae to viable N. ceranae spores could affect bee development. KW - Bee diseases KW - Wild bees KW - Nosema ceranae KW - Osmia bicornis KW - Pathogen transmission KW - Solitary bees KW - Bee health PY - 2019 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-496497 DO - https://doi.org/10.3390/insects10110380 VL - 10 IS - 11 SP - 380 PB - MDPI AN - OPUS4-49649 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Balzer, R. A1 - Behrens, H. A1 - Schuth, S. A1 - Waurischk, Tina A1 - Reinsch, Stefan A1 - Müller, Ralf A1 - Fechtelkord, M. A1 - Deubener, J. T1 - The influence of H2O and SiO2 on the structure of silicoborate glasses N2 - To understand the impact of dissolved water on structure and properties, four boron-rich glasses of molar compositions 15-x Na2O x CaO 15 SiO2 70 B2O3 (with x=0, 7.5, 10) and 10 Na2O 15 SiO2 75 B2O3 were prepared and subsequently hydrated (up to 8 wt% H2O). Density measurements show a non-linear trend upon hydration implying large structural changes in particular at water contents<2 wt%. Near-infrared spectroscopy shows hydroxyl groups are the dominant species in all glasses upon the entire range of water content. Molecular H2O is detectable only at total water contents>2 wt%. 11B MAS NMR spectra show that the abundance of BO4 species is mainly controlled by ratio of (Na2O+CaO)/B2O3 while incorporation of water plays a minor role. Compared to borate glasses, the efficiency of formation of BO4 tetrahedra is favored by crosslinking of the network by SiO4-units. The glass transition temperatures, determined by differential thermal analysis, decreases continuously with water content due to breakage of B-O-B bonds by hydrolysis. However, compared to Silicates and aluminosilicates, the effect of dissolved water is less pronounced which can be explained by weaker B-O-B bonds in comparison to Si-O-Si bonds. KW - High pressure KW - Water speciation KW - Silicoborate glasses KW - Infrared spectroscopy KW - NMR spectroscopy PY - 2019 DO - https://doi.org/10.1016/j.jnoncrysol.2019.05.030 VL - 519 SP - 38 EP - 51 PB - Elsevier B.V. AN - OPUS4-48748 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kiefer, P. A1 - Balzer, R. A1 - Deubener, J. A1 - Behrens, H. A1 - Waurischk, Tina A1 - Reinsch, Stefan A1 - Müller, Ralf T1 - Density, elastic constants and indentation hardness of hydrous soda-lime silica glasses N2 - The effect of structural water on density, elastic constants and microhardness of water-bearing soda-lime-silica glasses of up to 21.5 mol% total water is studied. It is found that the Poisson ratio and the water content are positively correlated, while density and the elastic moduli decrease with increasing water content. Vickers hardness decreases by approximately 27% from the dry to the most hydrous glass. For water fractions <3 mol%, the dependencies are non-linear reflecting the non-linear change in the concentrations of OH and H2O molecules dissolved, whereas for water fractions >3 mol% linear dependencies are found. To distinguish the effect of structural water and environmental water, indentations were performed in toluene, nitrogen gas and air. Timedependent softening was evident for testing dry glasses in humid atmospheres as well as for tests of hydrous glasses in dry atmospheres. This indicates that the response times of dissolved water species are effectively equal in both scenarios. KW - Elastic constants KW - Soda-lime-silica KW - Glass KW - Water content KW - Microhardness PY - 2019 DO - https://doi.org/10.1016/j.jnoncrysol.2019.119480 SN - 0022-3093 SN - 1873-4812 VL - 521 SP - 119480 PB - Elsevier B.V. AN - OPUS4-48758 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 - Reveron, H. A1 - Serrano-Munoz, Itziar A1 - Kupsch, Andreas A1 - Müller, Bernd R. A1 - Chevalier, J. A1 - Bruno, Giovanni T1 - Transformation-induced plasticity in zirconia during tensile loading: A combined microscopy and synchrotron X-ray refraction study N2 - The stress-induced tetragonal to monoclinic (t-m) zirconia phase transformation can provide a certain degree of plasticity to Ceria-stabilized (Ce-TZP) zirconia-based composites. Characterizing and monitoring this phase transition on a millimeter-size range, within the bulk and in-situ remains a challenge. In this work, the mechanical behavior of Ce-TZP based composite was studied in tension, combining microscopy and synchrotron Xray refraction techniques. In contrast with microscopy methods, which only provide surface information, X-ray refraction radiography (SXRR) allowed the visualization of all the transformation bands, over the entire length and thickness of tested specimens, opening up new avenues for in-situ stress-induced t-m transformation studies. KW - Zirconia KW - Ceria KW - Composite KW - Phase transformation KW - Plasticity KW - Synchrotron X-ray refraction PY - 2024 DO - https://doi.org/10.1016/j.matlet.2024.136445 SN - 0167-577X SN - 1873-4979 VL - 366 SP - 1 EP - 4 PB - Elsevier Ltd. CY - Amsterdam AN - OPUS4-59977 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Nellesen, J. A1 - Laquai, René A1 - Müller, Bernd R. A1 - Kupsch, Andreas A1 - Hentschel, M. P. A1 - Anar, N. B. A1 - Soppa, E. A1 - Tillmann, W. A1 - Bruno, Giovanni T1 - In situ analysis of damage evolution in an Al/Al2O3 MMC under tensile load by synchrotron X-ray refraction imaging N2 - The in situ analysis of the damage evolution in a metal Matrix composite (MMC) using synchrotron X-ray refraction radiography (SXRR) is presented. The investigated material is an Al alloy (6061)/10 vol% Al2O3 MMC after T6 heat treatment. In an interrupted tensile test the gauge section of dog bone-shaped specimens is imaged in different states of tensile loading. On the basis of the SXRR images, the relative change of the specific surface (proportional to the amount of damage) in the course of tensile loading was analyzed. It could be shown that the damage can be detected by SXRR already at a stage of tensile loading, in which no Observation of damage is possible with radiographic absorption-based imaging methods. Moreover, the quantitative analysis of the SXRR images reveals that the amount of damage increases homogeneously by an average of 25% with respect to the Initial state. To corroborate the experimental findings, the damage distribution was imaged in 3D after the final tensile loading by synchrotron X-ray refraction computed tomography (SXRCT) and absorption-based synchrotron X-ray computed tomography (SXCT). It could be evidenced that defects and damages cause pronounced indications in the SXRCT images. KW - Composite materials KW - Defects KW - Micro analysis PY - 2018 DO - https://doi.org/10.1007/s10853-017-1957-x SN - 0022-2461 SN - 1573-4803 VL - 53 IS - 8 SP - 6021 EP - 6032 PB - Springer US AN - OPUS4-44241 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Müller, Bernd R. A1 - Kupsch, Andreas A1 - Laquai, René A1 - Nellesen, J. A1 - Tillmann, W. A1 - Kasperovich, G. A1 - Bruno, Giovanni T1 - Microstructure characterisation of advanced materials via 2D and 3D X-ray refraction techniques N2 - 3D imaging techniques have an enormous potential to understand the microstructure, its evolution, and its link to mechanical, thermal, and transport properties. In this conference paper we report the use of a powerful, yet not so wide-spread, set of X-ray techniques based on refraction effects. X-ray refraction allows determining internal specific surface (surface per unit volume) in a non-destructive fashion, position and orientation sensitive, and with a nanometric detectability. We demonstrate showcases of ceramics and composite materials, where microstructural parameters could be achieved in a way unrivalled even by high-resolution techniques such as electron microscopy or computed tomography. We present in situ analysis of the damage evolution in an Al/Al2O3 metal matrix composite during tensile load and the identification of void formation (different kinds of defects, particularly unsintered powder hidden in pores, and small inhomogeneity’s like cracks) in Ti64 parts produced by selective laser melting using synchrotron X-ray refraction radiography and tomography. T2 - THERMEC 2018: 10TH international conference on processing and manufacturing of advanced materials CY - Paris, France DA - 08.07.2018 KW - Additive manufacturing (AM) KW - Creep KW - Damage evolution KW - Synchrotron X-ray refraction radiography KW - Metal matrix composites PY - 2018 UR - https://www.scientific.net/MSF.941.2401 SN - 978-3-0357-1208-7 DO - https://doi.org/10.4028/www.scientific.net/MSF.941.2401 SN - 1662-9752 SN - 0255-5476 VL - 941 SP - 2401 EP - 2406 PB - Trans Tech Publications CY - Switzerland AN - OPUS4-47148 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Müller, Christina A1 - Bertovic, Marija A1 - Holstein, R. A1 - Kanzler, Daniel A1 - Pitkänen, J. A1 - Ronneteg, U. A1 - Heckel, Thomas T1 - A plenary view on the vigour of our NDE reliability models N2 - Using the Modular Reliability Model the three different main influencing elements, i.e. intrinsic capability (IC), application parameters (AP) and the human factors (HF), are, in the first instance, investigated separately. The intrinsic capability stands for the pure physical-technological process of the signal detection caused by the waves or the rays from a material defect in the presence of noise (driven by the material and the devices). This intrinsic capability is the upper bound of the possible reliability. Already when measuring this intrinsic capability for thick walled components the original one-parameter POD must be extended to a multiparameter POD, where, in addition to the defect size, a number of additional physical parameters, such as the grain size distribution (or attenuation), defect depth, and angle or surface roughness, must be considered. For real life cycle assessments it is necessary to evaluate the signal response from real defects. The industrial application factors, e.g. coupling conditions, limited accessibility, heat and environmental vibrations, diminish the reliability. The amount of reduction can be determined quantitatively, if the underlying conditions are controlled. In case they are not controlled it is necessary to count for a fluctuation in the reliability in the field anyway. The third group of important influencing factors are the human factors, which do not only cover the individual performance capability of the inspectors but also the design of the working place,the procedure, the teamwork quality, interaction with systems, the organization, and finally, the relationship between the companies involved in the inspection process and to which extend the responsible parties are aware of it. When comparing an “ideal inspection” with a “real inspection” it is worth while to look how the existing practices, rules and standards support reliable testing and where the “delta” is. In the context of vigor, with respect to the industrial end user, it needs to be shown how the level of reliability of NDE, influenced by the different factors, has an impact on acceptance or rejection of safety critical parts. T2 - 5th European-American workshop on reliability of NDE CY - Berlin, Germany DA - 07.10.2013 PY - 2013 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-312658 SN - 978-3-940283-53-5 IS - DGZfP-BB 144 SP - Lecture 2, 1 EP - 18 PB - Deutsche Gesellschaft für Zerstörungsfreie Prüfung (DGZfP) CY - Berlin AN - OPUS4-31265 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Laquai, René A1 - Müller, Bernd R. A1 - Nellesen, J. A1 - Hentschel, M.P. A1 - Kupsch, Andreas A1 - Tillmann, W. T1 - Synchrotron-Refraktion mit in-situ Zugbelastung zur Charakterisierung der Schadensentwicklung in Metall-Matrix- Kompositen N2 - Die Synchrotron-Refraktions-Topographie basiert auf der Brechung von Röntgenstrahlung an den Grenzflächen zwischen Materialien mit unterschiedlichem Brechungsindex. Refraktionseffekte verändern die Ausbreitungsrichtung der Röntgenstrahlung, welche mit Hilfe der Methode des Analyser-Based Imaging analysiert wird. Dabei wird ein Silizium-Einkristall im Strahlengang zwischen Probe und Detektor platziert. Dieser Analysator-Kristall filtert, innerhalb seiner Streuebene, die Röntgenstrahlung gemäß ihrer Ausbreitungsrichtung. Durch das Rastern verschiedener Winkelpositionen des Analysator-Kristalls erhält man das Winkelspektrum der von der Probe gebrochenen Strahlung. Aus dieser Rocking Curve lässt sich die spezifische innere Oberfläche der Probe bestimmen. Diese Information wird über einen 2D-Detektor mit einer nominellen Pixelgröße von 3,6 μm gewonnen. Die Installation einer Zugprüfmaschine ermöglicht es die Proben in verschiedenen Lastzuständen insitu zu untersuchen. Damit ist es möglich die spezifische innere Oberfläche in Abhängigkeit der Last darzustellen und so Schädigungsmechanismen abzuleiten. Der Vorteil bei der Ausnutzung des Refraktionseffekts gegenüber der einfachen Durchstrahlung ist die höhere Sensitivität gegenüber Defekten mit geringem Volumen aber großer Oberfläche. Somit werden auch Mikrorisse und, speziell bei Kompositen, die Enthaftung zwischen Matrix und Verstärkung (Partikel, Fasern) erfasst. In dieser Studie wurden Metall-Matrix-Komposite bestehend aus einer Aluminium-Matrix verstärkt mit Aluminiumoxid-Partikeln untersucht. Hierzu wurden knochenförmige Zugproben präpariert, deren Messlänge einen rechteckigen Querschnitt von 1,7 mm × 1,3 mm aufwies. Die Proben wurden einem Zugversuch unterzogen, welcher in Intervallen unterbrochen wurde. Bei jeder Unterbrechung wurde unter quasi-statischer Last die Rocking Curve gemessen und ein Radiogramm der spezifischen inneren Oberflächen berechnet. Dabei konnte ab dem Erreichen einer Last von ca. 600 N ein Anstieg der spezifischen inneren Oberfläche beobachtet werden. Demgegenüber zeigen die zum Vergleich durchgeführten Durchstrahlungsaufnahmen keinerlei Defekte. Daher belegt diese Untersuchung das Potential der Refraktion-Topographie zur frühzeitigen Erkennung von Schädigungen mit hoher Empfindlichkeit. T2 - DGZfP Jahrestagung 2017 CY - Koblenz, Germany DA - 22.05.2017 KW - Metall-Matrix-Komposite KW - Schadensentwicklung KW - Röntgen-Refraktions-Radiographie KW - In-situ Zugbelastung PY - 2017 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-405794 SN - 978-3-940283-85-6 SP - 1 EP - 7 PB - DGZfP AN - OPUS4-40579 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kanzler, Daniel A1 - Müller, Christina A1 - Pitkänen, J. T1 - Konzept für den Einsatz der Bayes'schen Statistik: In der Zuverlässigkeitsbestimmung von zerstörungsfreien Diagnosesystemen - Das Problem zu kleiner experimenteller Datenmengen N2 - Die statistische Qualitätskennzahl 'Probability of Detection (POD)' hängt von der Anzahl der zugrunde liegenden, brauchbaren Ergebnisse ab. Ist die Datenmenge niedrig, so ist auch die Aussage der POD eher beschränkt. Dennoch heißt eine große Zahl von Daten, nicht gleichzeitig, dass die POD für den realen Einsatz in der Produktion genügt. Es muss unterschieden werden, auf welcher Basis – unter welchen konkreten Bedingungen - die Daten erhoben wurden. Als wichtigste Ergebnisse zählen die Messergebnisse aus der Produktion der später verwendeten Prüfobjekte für den konkreten Einsatz. Noch bevor die zerstörungsfreien Prüfmethoden zuverlässig in der Produktion eingesetzt wurde, muss jedoch nachgewiesen werden, dass die real vorkommenden Fehler gefunden werden können. Das bedeutet, zu einem Zeitpunkt, an dem noch nicht ausreichend Daten vorhanden sind. Während für die realistische Prüfung die notwendige Anzahl der verschiedenen Fehler meist nicht erreicht wird, so fehlen bei der Bewertung der künstlichen Fehler wichtige Parameter und Einflussgrößen. Es muss somit eine Zwischenlösung gesucht werden, in der die Informationen von beiden Prüfungen kombiniert werden. Mit der Bayes’schen Statistik ermöglicht die Mathematik diese Informationen miteinander zu kombinieren und somit beide Informationen mit in die Bewertung einfließen zu lassen. Praktisch angewandt und erprobt wird die Vorgehensweise gemeinsam mit der Firma POSIVA, die sich mit dem Bau eines Endlagers für hoch-radioaktiven Abfall in Finnland beschäftigt. Hier wird als eine der technischen Barrieren ein Kupferbehälter für die Aufbewahrung der verbrauchten Brennstäbe genutzt. Dieser Kupferbehälter wird mit mehreren zerstörungsfreien Prüfmethoden geprüft. Anhand von Radiographiedaten wird gezeigt, dass die Aussagekraft der realistischen Fehlerdaten mit Hilfe der künstlichen Referenzfehlerdaten untermauert werden kann. T2 - DGZfP-Jahrestagung 2011 CY - Bremen, Germany DA - 30.05.2011 KW - Bayes'sche Statistik KW - POD KW - Fehlende Datenmenge PY - 2011 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-251598 SN - 978-3-940283-33-7 IS - DGZfP-BB 127 (Mi.3.C.3) SP - 1 EP - 9 PB - Deutsche Gesellschaft für Zerstörungsfreie Prüfung (DGZfP) AN - OPUS4-25159 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bertovic, Marija A1 - Müller, Christina A1 - Kanzler, Daniel A1 - Fahlbruch, B. A1 - Pitkänen, J. A1 - Ronneteg, U. T1 - 'Human factors' bei der Datenauswertung der zerstörungsfreien Prüfung am Beispiel der nuklearen Endlagerung N2 - Für eine ganzheitliche Betrachtung der Sicherheit bei der zerstörungsfreien Prüfung (ZfP) ist es unvermeidlich neben der Technik auch den Prüfer und die Prüforganisation einzubeziehen. Die Prüfung der Unversehrtheit von Endlagerbehältern ist eine eine sicherheitstechnisch wichtige Anwendung. Die Betreiber der geplanten finnischen und schwedischen Endlager, Posiva und SKB, kapseln den radioaktiven Abfall in Kupferkanistern ein und deponieren die Kanister dann in Felsgestein in einer Tiefe von ca. 500m. Die Kanister bestehen aus einem zylinderförmigen Kupfermantel mit einem Deckel und einem Boden, die zusammen die Außenumhüllung ergeben sowie einer Gusseisenmatrix für die Brennstäbe. Alle Komponenten werden auf ihre Dichtheit bzw. strukturelle Unversehrtheit mittels zerstörungsfreier Prüfmethoden geprüft, um sicher zu stellen, dass im Material und in den Schweißnähten keine kritischen Defekte vorhanden sind, die zu Freisetzungen in die Umgebung führen könnten. Vier ZfP Methoden (Ultraschall-, Wirbelstrom- und radiographische Prüfung, und die visuelle Prüfung anhand einer Kamera) werden mechanisiert durchgeführt, die gewonnenen Daten werden von qualifizierten Fachleuten ausgewertet und bieten so die Möglichkeit, dass Fehler entstehen. Das 'Human Factor'- Untersuchungskonzept besteht aus der Identifizierung potenzieller menschlicher Fehler, deren Ursachen und Präventionsmethoden. Mit Hilfe einer abgewandelten FMEA (Failure Modes and Effects Analysis) wurden mögliche Risiken identifiziert, die die Wahrscheinlichkeit für das Auftreten menschlicher Fehler bei der Datenauswertung erhöhen. Einige dieser Risiken sind beispielsweise Verantwortungsdiffusion beim 4-Augen-Prinzip, Übervertrauen in die Technik bei der automatischen Identifikation von Defekten sowie der Aufmerksamkeitsverlust bei dynamischer Bildbetrachtung. Deren Wirkung wird derzeit experimentell überprüft, um Ansatzpunkte für Optimierungen zu ermitteln und damit die Gesamtzuverlässigkeit des Systems zu verbessern. T2 - DGZfP-Jahrestagung 2011 CY - Bremen, Germany DA - 30.05.2011 KW - Human factors KW - UT KW - ET KW - ZfP KW - Nukleare Endlagerung PY - 2011 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-251584 UR - http://jt2011.dgzfp.de/Portals/jt2011/BB/p42-ku~1.pdf SN - 978-3-940283-33-7 IS - DGZfP-BB 127 (P 42) SP - 1 EP - 2 PB - Deutsche Gesellschaft für Zerstörungsfreie Prüfung (DGZfP) AN - OPUS4-25158 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Waurischk, Tina A1 - Deubener, J. A1 - Müller, Ralf T1 - Internal friction and energy dissipation during fracture in silicate glasses N2 - To obtain a deeper insight into the nature of energy dissipation during fracture, the internal friction of 13 borosilicate, aluminosilicate, soda-lime, and lead-containing glasses, for which inert crack growth data are known, was measured using dynamic mechanical thermal analysis. For asymmetrically bent glass beams, the loss tangent, tan δ, was determined between 0.2 and 50 Hz at temperatures between 273 K and the glass transition temperature, Tg. It was found that the area under the tan δ vs T·Tg−1 curve correlates with the crack growth exponent, n, in the empirical v = v0·KIn relation between crack growth velocity, v, and stress intensity, KI, which indicates that n correlates with the degree of energy dissipation of sub-Tg relaxation phenomena. KW - Glass KW - Internal friction KW - Crack growth PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-651371 DO - https://doi.org/10.1063/5.0255432 SN - 0021-9606 VL - 162 IS - 19 SP - 1 EP - 9 PB - AIP Publishing AN - OPUS4-65137 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Pan, Z. A1 - Waurischk, Tina A1 - Duval, A. A1 - Müller, Ralf A1 - Deubener, J. A1 - Krishnan, N. M. A. A1 - Wondraczek, K. A1 - Wondraczek, L. T1 - Precise Real‐Time Measurement of Liquid Viscosity Using Digital Video Data N2 - Quantitative knowledge of liquid viscosity is of fundamental importance in many areas of materials synthesis and processing. However, the determination of viscosity often relies on specialized experimental equipment, offline experimentation, or invasive procedures, in particular when required in extreme conditions such as at high temperature, high pressure, and in confined or corrosive environments. Here, this study proposes and validates a fast and simple method that mimics the intuitive perception of liquid flow within a quantitative framework. For this, this study employs digital video observation to derive quantitative values of the shear viscosity of liquids, with high precision and rapid acquisition rates. The technique involves capturing liquid dynamics after minor mechanical stimulation. Processed imaging data are indexed by similarity and referenced to a digital database generated with a finite element model, from which values of viscosity are obtained in line. The approach is tested on water at room temperature and on a high‐temperature glass melt. Covering a viscosity range of four orders of magnitude, both yield convincing agreement with tabulated reference data at low computational cost. KW - Glass KW - Liquid Viscosity KW - Digital Video Data KW - Finite Element Method PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-651363 DO - https://doi.org/10.1002/aisy.202500297 SN - 2640-4567 VL - 7 IS - 12 SP - 1 EP - 12 PB - Wiley VHC-Verlag AN - OPUS4-65136 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Brücher, M. A1 - von Bohlen, A. A1 - Jacob, P. A1 - Franzke, J. A1 - Radtke, Martin A1 - Reinholz, Uwe A1 - Müller, Bernd R. A1 - Scharf, Oliver A1 - Hergenröder, R. T1 - The charge of solid-liquid interfaces measured by X-ray standing waves and streaming current N2 - Measurements of ion distributions at a charged solid–liquid interface using X-ray standing waves (XSW) are presented. High energy synchrotron radiation (17.48 keV) is used to produce an XSW pattern inside a thin water film on a silicon wafer. The liquid phase is an aqueous solution containing Br and Rb ions. The surface charge is adjusted by titration. Measurements are performed over a pH range from 2.2–9, using the native Si oxide layer and functional (amine) groups as surface charge. The Debye length, indicating the extension of the diffuse layer, could be measured with values varying between 1–4 nm. For functionalized wafers, the pH dependent change from attraction to repulsion of an ion species could be detected, indicating the isoelectric point. In combination with the measurement of the streaming current, the surface charge of the sample could be quantified. KW - Interfacial charge KW - Solid/liquid interfaces KW - Surface analysis KW - Surface functionalization KW - X-ray spectrometry KW - X-ray KW - Standing waves KW - XSW KW - Streaming current KW - Synchrotron radiation PY - 2010 DO - https://doi.org/10.1002/cphc.201000166 SN - 1439-4235 SN - 1439-7641 VL - 11 IS - 10 SP - 2118 EP - 2123 PB - Wiley-VCH Verl. CY - Weinheim AN - OPUS4-22057 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Zoёga, Andreas A1 - Kurz, J. H. A1 - Oelschlägel, T. A1 - Rohrschneider, A. A1 - Müller, Christina A1 - Pavlovic, Mato A1 - Hintze, H. A1 - Kanzler, D. T1 - Investigations to introduce the probability of detection method for ultrasonic inspection of hollow axles at Deutsche Bahn N2 - Currently at Deutsche Bahn (DB) ultrasonic inspections in maintenance procedures for wheelset axles with a bore hole are, to the greatest possible extent, carried out using automated ultrasonic inspection system. Although the acceptance levels are in accordance with DIN 27201 part 7, the testing results have shown in recent years that in the case of true indications, the effective defect sizes were far below the level of acceptance. Due to this experience it can be assumed that the automated ultrasonic inspection systems are testing substantially more sensitively than required. This increased sensitivity leads to an increase in false indications, generally resulting in the unnecessary demounting of wheelsets. In Research cooperation between Federal Institute for Materials Research and Testing (BAM) and DB the effective flaw detection sensitivity of existing automated ultrasonic inspection system will be determined and the true/false indication ratio optimised. Through systematic investigations with the Probability of Detection method on the existing automated ultrasonic inspection system the results could be directly applied to the optimisation of existing ultrasonic inspections of wheelset axles with a bore hole in maintenance procedures and the level of reliability can be considerably increased. T2 - 19th World Conference on Non-Destructive Testing CY - München, Germany DA - 13.06.2016 KW - NDT KW - Reliability KW - POD KW - Railway KW - Axles KW - UT PY - 2016 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-375813 UR - http://www.ndt.net/article/wcndt2016/papers/we2g4.pdf SP - id 19515, 1 EP - 8 AN - OPUS4-37581 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Buckle, T. A1 - van der Wal, S. A1 - van Malderen, S. A1 - Müller, Larissa A1 - Kuil, J. A1 - van Unen, V. A1 - Peters, R. A1 - van Bemmel, M. A1 - McDonnell, L. A1 - Velders, A. A1 - Koning, F. A1 - Vanhaeke, F. A1 - van Leeuwen, F. T1 - Hybrid imaging labels: providing the link between mass spectrometry-based molecular pathology and theranostics N2 - Development of theranostic concepts that include inductively coupled plasma mass spectrometry (ICP-MS) and laser ablation ICP-MS (LA-ICP-MS) imaging can be hindered by the lack of a direct comparison to more standardly used methods for in vitro and in vivo evaluation; e.g. fluorescence or nuclear medicine. In this study a bimodal (or rather, hybrid) tracer that contains both a fluorescent dye and a chelate was used to evaluate the existence of a direct link between mass spectrometry (MS) and in vitro and in vivo molecular imaging findings using fluorescence and radioisotopes. At the same time, the hybrid label was used to determine whether the use of a single isotope label would allow for MS-based diagnostics. KW - Imaging KW - Laser Ablation ICP-MS KW - Diagnostics PY - 2017 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-396813 DO - https://doi.org/10.7150/thno.17484 VL - 7 IS - 3 SP - 624 EP - 633 PB - IvySpring AN - OPUS4-39681 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Bennet, Francesca A1 - Müller, Anja A1 - Radnik, Jörg A1 - Hachenberger, Y. A1 - Jungnickel, H. A1 - Laue, P. A1 - Luch, A. A1 - Tentschert, J. T1 - Preparation of Nanoparticles for ToF-SIMS and XPS Analysis N2 - Nanoparticles have gained increasing attention in recent years due to their potential and application in different fields including medicine, cosmetics, chemistry, and their potential to enable advanced materials. To effectively understand and regulate the physico-chemical properties and potential adverse effects of nanoparticles, validated measurement procedures for the various properties of nanoparticles need to be developed. While procedures for measuring nanoparticle size and size Distribution are already established, standardized methods for analysis of their surface chemistry are not yet in place, although the influence of the surface chemistry on nanoparticle properties is undisputed. In particular, storage and preparation of nanoparticles for surface analysis strongly influences the analytical results from various methods, and in order to obtain consistent results, sample preparation must be both optimized and standardized. In this contribution, we present, in detail, some standard procedures for preparing nanoparticles for surface analytics. In principle, nanoparticles can be deposited on a suitable substrate from suspension or as a powder. Silicon (Si) Wafers are commonly used as substrate, however, their cleaning is critical to the process. For sample preparation from suspension, we will discuss drop-casting and spin-coating, where not only the cleanliness of the substrate and purity of the suspension but also its concentration play important roles for the success of the preparation methodology. For nanoparticles with sensitive ligand shells or coatings, deposition as powders is more suitable, although this method requires particular care in fixing the sample. KW - Titania nanoparticles KW - X-ray photoelectron spectroscopy KW - Secondary ion mass spectrometry KW - Surface chemisttry PY - 2020 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-520103 UR - https://www.jove.com/video/61758 DO - https://doi.org/10.3791/61758 VL - 163 SP - e61758 AN - OPUS4-52010 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kanzler, Daniel A1 - Müller, Christina A1 - Pitkänen, J. A1 - Ewert, Uwe T1 - Bayesian approach for the evaluation of the reliability of non-destructive testing methods: combination of data from artificial and real defects N2 - The Probability of Detection (POD) is used to evaluate the detectability of non-destructive testing (NDT) systems. The POD is highly dependent on the amount of available data. The Bayesian approach provides a solution to compute POD-curves in case of a small amount of real defects without losing the necessary information. The result contains the needed information for the computation of POD-curves for real defects with an acceptable amount of information, even for sparse amount of data. In this paper is shown limitations of the Bayesian approach and how it can be applied to NDT. The Bayesian approach is applied in this case to the evaluation of radiographic testing. Bayesian approach is applied to determine POD-curves for the inspection techniques of nuclear fuel disposal canisters. The reason for using Bayesian approach is the high safety demands and also the low amount of real defects due to the high quality of the reliable production techniques. T2 - 18th WCNDT - World conference on nondestructive testing CY - Durban, South Africa DA - 16.04.2012 KW - Reliability KW - Probability of Detection KW - Real defect testing KW - Bayesian statistics KW - Radiographic testing PY - 2012 SN - 978-0-620-52872-6 SP - 1 EP - 6 (Paper 196) AN - OPUS4-27582 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Wolff, M. A1 - Wonneberger, R. A1 - Freiberg, K.E. A1 - Hertwig, Andreas A1 - Bonse, Jörn A1 - Giebeler, L. A1 - Koitzsch, A. A1 - Kunz, C. A1 - Weber, H. A1 - Hufenbach, J.K. A1 - Müller, F.A. A1 - Gräf, S. T1 - Formation of laser-induced periodic surface structures on Zr-based bulk metallic glasses with different chemical composition N2 - Bulk metallic glasses (BMG) are amorphous metal alloys known for their unique physical and mechanical properties. In the present study, the formation of femtosecond (fs) laser-induced periodic surface structures (LIPSS) on the Zr-based BMGs Zr46Cu46Al8, Zr61Cu25Al12Ti2, Zr52.5Cu17.9Al10Ni14.6Ti5 (Vit105) and Zr57Cu15.4Al10Ni12.6Nb5 (Vit106) was investigated as a function of their different chemical composition. For this purpose, LIPSS were generated on the sample surfaces in an air environment by fs-laser irradiation (λ = 1025 nm, τ = 300 fs, frep = 100 kHz). The surface topography was characterized by scanning electron microscopy and atomic force microscopy. Moreover, the impact of LIPSS formation on the structure and chemical surface composition was analyzed before and after fs-laser irradiation by X-ray diffraction and X-ray photoelectron spectroscopy as well as by transmission electron microscopy in combination with energy dispersive X-ray spectroscopy. Despite the different chemical composition of the investigated BMGs, the fs-laser irradiation resulted in almost similar properties of the generated LIPSS patterns. In the case of Zr61Cu25Al12Ti2, Vit105 and Vit106, the surface analysis revealed the preservation of the amorphous state of the materials during fs-laser irradiation. The study demonstrated the presence of a native oxide layer on all pristine BMGs. In addition, fs-laser irradiation results in the formation of laser-induced oxide layers of larger thickness consisting of an amorphous ZrAlCu-oxide. The precise laser-structuring of BMG surfaces on the nanoscale provides a versatile alternative to thermoplastic forming of BMG surfaces and is of particular interest for the engineering of functional material surfaces. KW - Bulk metallic glasses KW - Femtosecond laser KW - Laser-induced periodic surface structures (LIPSS) KW - Chemical analysis KW - Oxidation PY - 2023 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-581799 DO - https://doi.org/10.1016/j.surfin.2023.103305 SN - 2468-0230 VL - 42 SP - 1 EP - 11 PB - Elsevier B.V. AN - OPUS4-58179 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Stephan, H. A1 - Walther, M. A1 - Fähnemann, S. A1 - Ceroni, P. A1 - Molloy, J.K. A1 - Bergamini, G. A1 - Heisig, F. A1 - Müller, C.E. A1 - Kraus, Werner A1 - Comba, P. T1 - Bispidines for dual imaging N2 - The efficient transformation of the hexadentate bispidinol 1 into carbamate derivatives yields functional bispidines enabling convenient functionalization for targeted imaging. The BODIPY-substituted bispidine 3 combines a coordination site for metal ions, such as radioactive 64CuII, with a fluorescent unit. Product 3 was thoroughly characterized by standard analytical methods, single crystal X-ray diffraction, radiolabeling, and photophysical analysis. The luminescence of ligand 3 was found to be strongly dependent on metal ion coordination: CuII quenches the BODIPY fluorescence, whereas NiII and ZnII ions do not affect it. It follows that, in imaging applications with the positron emitter 64CuII, residues of its origin from enriched 64Ni and the decay products 64NiII and 64ZnII, efficiently restore the fluorescence of the ligand. This allows for monitoring of the emitted radiation as well as the fluorescence signal. The stability of the 64CuII–3 complex is investigated by transmetalation experiments with ZnII and NiII, using fluorescence and radioactivity detection, and the results confirm the high stability of 64CuII–3. In addition, metal complexes of ligand 3 with the lanthanide ions TbIII, EuIII, and NdIII are shown to exhibit emission of the BODIPY ligand and the lanthanide ion, thus enabling dual emission detection. KW - Bispidines KW - Chelates KW - Imaging agents KW - Lanthanides KW - Radiolabeling KW - Nuclear medical application KW - Radioactive labelling KW - SPECT PY - 2014 DO - https://doi.org/10.1002/chem.201404086 SN - 0947-6539 SN - 1521-3765 VL - 20 IS - 51 SP - 17011 EP - 17018 PB - Wiley-VCH Verl. CY - Weinheim AN - OPUS4-32320 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Meyer, Klas A1 - Ruiken, J.-P. A1 - Illner, M. A1 - Paul, Andrea A1 - Müller, D. A1 - Esche, E. A1 - Wozny, G. A1 - Maiwald, Michael T1 - Process spectroscopy in microemulsions - setup and multi-spectral approach for reaction monitoring of a homogeneous hydroformylation process N2 - Reaction monitoring in disperse systems, such as emulsions, is of significant technical importance in various disciplines like biotechnological engineering, chemical industry, food science, and a growing number other technical fields. These systems pose several challenges when it comes to process analytics, such as heterogeneity of mixtures, changes in optical behavior, and low optical activity. Concerning this, online nuclear magnetic resonance (NMR) spectroscopy is a powerful technique for process monitoring in complex reaction mixtures due to its unique direct comparison abilities, while at the same time being non-invasive and independent of optical properties of the sample. In this study the applicability of online-spectroscopic methods on the homogeneously catalyzed hydroformylation system of 1-dodecene to tridecanal is investigated, which is operated in a mini-plant scale at Technische Universität Berlin. The design of a laboratory setup for process-like calibration experiments is presented, including a 500 MHz online NMR spectrometer, a benchtop NMR device with 43 MHz proton frequency as well as two Raman probes and a flow cell assembly for an ultraviolet and visible light (UV/VIS) spectrometer. Results of high-resolution online NMR spectroscopy are shown and technical as well as process-specific problems observed during the measurements are discussed. KW - Online-spectroscopy KW - Quantitative NMR spectroscopy KW - Process analytical technology KW - Microemulsions PY - 2017 DO - https://doi.org/10.1088/1361-6501/aa54f3 SN - 0957-0233 SN - 1361-6501 VL - 28 IS - 3 SP - 035501-1 EP - 035501-11 PB - IOP Publishing Ltd. AN - OPUS4-39091 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Meyer, Klas A1 - Ruiken, J.-P. A1 - Illner, M. A1 - Müller, D. A1 - Esche, E. A1 - Paul, Andrea A1 - Wozny, G. A1 - Maiwald, Michael T1 - Online spectroscopy in microemulsions – A process analytical approach for hydroformylation miniplant I – Experimental setup and NMR reaction monitoring N2 - Hydroformylation represents an important homogeneous catalyzed process, which is widely used within chemical industry. Usually applied with simple alkenes like Propene and Butene aldehydes obtained from alkenes >C6 are relevant intermediates in production of plasticizers, surfactants and polymers. Today the active catalyst species is often based on valuable Rhodium complexes in aqueous solution. This implies the problem of limited water solubility of the reactands, which is acceptable for short chain lengths, but states a problem in case of higher alkenes. Along with that efficient separation and recycling of the catalyst becomes more complicated. There are different approaches tackling this problem, e.g., by using of salt formation in the BASF process or downstream distillation within the Shell process T2 - 11. Kolloquium Arbeitskreis Prozessanalytik CY - Wien, Austria DA - 30.11.2015 KW - Prozessanalytik KW - Process analytical technology KW - Emuslions KW - Hydroformylation KW - Online NMR spectroscopy KW - Reaction monitoring PY - 2015 SP - 51 EP - 51 PB - Bundesanstalt für Materialforschung und -prüfung (BAM) CY - Berlin AN - OPUS4-38845 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Paul, Andrea A1 - Ruiken, J.-P. A1 - Meyer, Klas A1 - Westad, Frank A1 - Illner, M. A1 - Müller, D. A1 - Wozny, G. A1 - Maiwald, Michael T1 - Online spectroscopy in microemulsions – A process analytical approach for hydroformylation miniplant II - Calibration and prediction by Raman spectra N2 - The Collaborative Research Center InPROMPT aims to establish a novel process concept for the hydroformylation of long-chained olefins, using a rhodium complex as catalyst in the presence of syngas. Recently, the hydroformylation in micro-emulsions, which allows for the efficient recycling of the expensive rhodium catalyst, was found to be feasible. However, the temperature and concentration sensitive multi-phase system demands a continuous observation of the reaction to achieve an operational and economically feasible plant operation. For that purpose, we tested the potential of both NMR and Raman spectroscopy for process control assistance. The lab-scale experiments were supported by sampling for off-line GC-analysis as reference analytics. The results of the NMR experiments will be part of another contribution. T2 - 11. Kolloquium Arbeitskreis Prozessanalytik CY - Wien, Austria DA - 30.11.2015 KW - Prozessanalytik KW - Process analytical technology KW - Prozess-Spektroskopie KW - Emulsions KW - Hydroformylation KW - Reaction monitoring KW - Raman spectroscopy PY - 2015 SP - 66 EP - 67 PB - Bundesanstalt für Materialforschung und -prüfung (BAM) CY - Berlin AN - OPUS4-38846 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Gardei, André A1 - Garcia, O. A1 - Riedl, Martin A1 - Vanhellemond, I. A1 - Suput, J.S. A1 - Santarelli, M.-L. A1 - Rodríguez-Maribona, I. A1 - Müller, Urs ED - Jadwiga W. Lukaszewicz, ED - Piotr Niemcewicz, T1 - Performance and durability of a new antigraffiti system for cultural heritage - the EC project GRAFFITAGE T2 - 11th International Congress on Deterioration and Conservation of Stone CY - Torun, Poland DA - 2008-09-15 KW - Cultural heritage KW - Antigraffiti system KW - Sandstone KW - Limestone KW - Brick KW - Monument KW - Cleaning KW - Historische Baustoffe PY - 2008 SN - 978-83-231-2237-1 VL - II SP - 889 EP - 897 PB - Nicolaus Copernicus University Press CY - Torun, Poland AN - OPUS4-18844 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Debatin, F. A1 - Thomas, A. A1 - Kelling, A. A1 - Hedin, N. A1 - Bacsik, Z. A1 - Senkovska, I. A1 - Kaskel, S. A1 - Junginger, M. A1 - Müller, H. A1 - Schilde, U. A1 - Jäger, Christian A1 - Friedrich, A. A1 - Holdt, H.-J. T1 - In situ synthesis of an imidazolate-4-amide-5-imidate ligand and formation of a microporous zinc-organic framework with H2-and CO2-storage ability KW - Metal-organic framework KW - Synthesis KW - XRD KW - FTIR KW - NMR KW - Gas sorption KW - Microporous materials KW - N,O ligands KW - Solvothermal synthesis PY - 2010 DO - https://doi.org/10.1002/anie.200906188 SN - 1433-7851 SN - 1521-3773 SN - 0570-0833 VL - 49 IS - 7 SP - 1258 EP - 1262 PB - Wiley-VCH CY - Weinheim AN - OPUS4-21132 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Schmelzer, J.W.P. A1 - Potapov, O. V. A1 - Fokin, V. M. A1 - Müller, Ralf A1 - Reinsch, Stefan T1 - The effect of elastic stress and relaxation on crystal nucleation in lithium disilicate glass N2 - In the framework of a general theoretical approach recently developed, the effect of elastic stresses on the rate of nucleation of crystallites of critical sizes in the process of crystallization of lithium disilicate glasses is studied. Hereby both the evolution of elastic stresses – due to changes in the specific volume of the crystallizing system (i.e., differences in the densities of the melt and the crystal) – and their relaxation – connected with viscous flow – are taken into consideration. If the classical theory of nucleation is employed for the determination of the nucleation rates (modified by taking into account elastic stresses), elastic stresses may lead, for the system under consideration, to a decrease of the nucleation rate by up to two orders of magnitude. As shown, the theory allows an at least qualitatively correct incorporation of the effect of elastic stresses and stress relaxation into the description of nucleation phenomena in glass-forming melts. PY - 2004 DO - https://doi.org/10.1016/j.jnoncrysol.2003.10.002 SN - 0022-3093 VL - 333 IS - 2 SP - 150 EP - 160 PB - North-Holland Publ. Co. CY - Amsterdam AN - OPUS4-6236 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Müller, J.-P. T1 - Plasmagestützte Herstellung von Magnetit-Schichten T2 - 9. Bundesdeutsche Fachtagung Plasmatechnologie CY - Stuttgart, Germany DA - 1999-03-03 PY - 1999 AN - OPUS4-6228 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Güttler, B. A1 - Schiel, D. A1 - Danzebrink, H. A1 - Unger, Wolfgang A1 - Gross, Thomas A1 - Lippitz, Andreas A1 - Müller, J.-P. T1 - Physical and Chemical Characterization of Thermal and Native Siliconoxide layers on Silicon T2 - Symposium "Reference Materials for Technologies in the New Millenium" CY - Berlin, BAM, Germany DA - 2000-05-22 PY - 2000 SP - 1(?) EP - 7(?) AN - OPUS4-6924 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - RPRT A1 - Gaal, Mate A1 - Bertovic, Marija A1 - Müller, Christina A1 - Zickler, S. A1 - Fahlbruch, B. A1 - Spokoiny, V. A1 - Schombach, D. A1 - Just, Tilman A1 - Cramer, H.-J. T1 - Untersuchungen zum Einfluss menschlicher Faktoren auf das Ergebnis von zerstörungsfreien Prüfungen, Möglichkeiten zur Minimierung dieses Einflusses und Bewertung der Prüfergebnisse KW - Menschliche Faktoren KW - ZfP KW - Manuelle Ultraschallprüfung KW - WkP KW - KKW PY - 2009 IS - BfS-Projekt SR 2514 / Endbericht SP - 1 EP - 79 CY - Salzgitter AN - OPUS4-26081 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Müller, Renate A1 - Rudolphi, Reinald A1 - Kasper, F.-J. T1 - Fensteranschlüsse. Numerische Untersuchungen zum wärmeschutztechnischen Verhalten PY - 1990 SN - 0017-1107 VL - 43 IS - 11 SP - 4, 36 EP - 45 PB - Gentner CY - Stuttgart AN - OPUS4-1256 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Müller, Renate A1 - Rudolphi, Reinald A1 - Kasper, F.-J. A1 - Wagner, Armin T1 - The Thermal Transmittance of Windows PY - 1983 SN - 0306-9931 VL - 11 IS - 5 SP - 292 EP - 297 PB - Centre Scientifique et Technique du Bâtiment CY - Paris AN - OPUS4-1242 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Müller, Renate A1 - Rudolphi, Reinald A1 - Kasper, F.J. A1 - Wagner, Armin T1 - Zum wärmeschutztechnischen Verhalten des Anschlußbereiches Fenster-Wand PY - 1984 SN - 0016-9277 VL - 105 IS - 4 SP - 169-170 und 223-227 PB - Oldenbourg CY - München AN - OPUS4-1244 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Müller, Renate A1 - Rudolphi, Reinald A1 - Kasper, F.-J. A1 - Wagner, Armin T1 - Rechnerische Simulation von Versuchen am Beispiel des Wärmeschutzes von Fensterkonstruktionen PY - 1986 SN - 0025-5300 VL - 28 IS - 4 SP - 107 EP - 108 PB - Carl Hanser Verlag CY - München AN - OPUS4-1249 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Müller, Renate A1 - Rudolphi, Reinald A1 - Kasper, F.-J. T1 - Numerische Untersuchungen zum Tauwasserrisiko von Mauerwerksaußenwinkeln und Ecken in Gebäuden (Teil 1) PY - 1988 SN - 0343-3560 VL - 17 IS - 3 SP - Titelblatt und S. 43 EP - 52 PB - Thiekötter CY - Münster AN - OPUS4-1250 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Müller, Renate A1 - Rudolphi, Reinald A1 - Kasper, F.-J. T1 - Numerische Untersuchungen zum Tauwasserrisiko von Mauerwerksaußenwinkeln und Ecken in Gebäuden (Teil 2) PY - 1988 SN - 0343-3560 VL - 17 IS - 4 SP - 53 EP - 59 PB - Thiekötter CY - Münster AN - OPUS4-1251 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Herrmann, Ralf A1 - Hille, Falk A1 - Said, Samir A1 - Sterthaus, Jens A1 - Müller, Karsten A1 - Quercetti, Thomas A1 - Wille, Frank A1 - Paffenholz, J.-A. A1 - Baeßler, Matthias ED - Papadrakakis, M. ED - Fragiadakis, M. ED - Papadimitriou, C. T1 - Implementing a Structural Health Monitoring system using digital models of the BAM large drop test facility in Horstwalde N2 - At the Bundesanstalt für Materialforschung und -prüfung (BAM) full scale specimens for nuclear transport and storage containers (casks) are tested for their structural integrity in a series of drop tests on the Test Site Technical Safety in Horstwalde, 50 km south of Berlin. These drop tests cause a major stress not only on the casks, but also on the steel tower structure of the test facility, itself. The load pattern makes the structure very interesting for detailed investigation. The focus of the monitoring lies on the bolted joints of the flange connections that are a typical connection for cylindrical elements if welding is technical or economical unfavorable. The definition of the monitoring takes was done by investigating the existing documents and inspection results accompanied by building an initial digital representation of the structure, consisting of two finite element (FE) models and a geometrical 3D point cloud representation. As a first step the structures behavior during static and dynamic loading was analyzed using measurement data and an updated numerical FE Model. The idea behind is to use models for a digital planning and operation/evaluation of the structural health monitoring. A static FE simulation and a dynamic FE simulation are generated, to investigate how the structure behaves under the load conditions. T2 - XI International Conference on Structural Dynamics (EuroDyn 2020) CY - Online meeting DA - 23.11.2020 KW - Structural Health Monitoring KW - Drop Tests KW - System Identification KW - Digital Models KW - BIM PY - 2020 UR - https://generalconferencefiles.s3-eu-west-1.amazonaws.com/eurodyn_2020_ebook_procedings_vol1.pdf SN - 978-618-85072-0-3 VL - 1 SP - 1293 EP - 1304 PB - Institute of Structural Analysis and Antiseismic Research CY - Athen AN - OPUS4-51592 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Ast, S. A1 - Fischer, Tobias A1 - Müller, H. A1 - Mickler, W. A1 - Schwichtenberg, M. A1 - Rurack, Knut A1 - Holdt, H.-J. T1 - Integration of the 1,2,3-triazole 'click' motif as a potent signalling element in metal ion responsive fluorescent probes N2 - In a systematic approach we synthesized a new series of fluorescent probes incorporating donor–acceptor (D-A) substituted 1,2,3-triazoles as conjugative π-linkers between the alkali metal ion receptor N-phenylaza-[18]crown-6 and different fluorophoric groups with different electron-acceptor properties (4-naphthalimide, meso-phenyl-BODIPY and 9-anthracene) and investigated their performance in organic and aqueous environments (physiological conditions). In the charge-transfer (CT) type probes 1, 2 and 7, the fluorescence is almost completely quenched by intramolecular CT (ICT) processes involving charge-separated states. In the presence of Na+ and K+ ICT is interrupted, which resulted in a lighting-up of the fluorescence in acetonitrile. Among the investigated fluoroionophores, compound 7, which contains a 9-anthracenyl moiety as the electron-accepting fluorophore, is the only probe which retains light-up features in water and works as a highly K+/Na+-selective probe under simulated physiological conditions. Virtually decoupled BODIPY-based 6 and photoinduced electron transfer (PET) type probes 3–5, where the 10-substituted anthracen-9-yl fluorophores are connected to the 1,2,3-triazole through a methylene spacer, show strong ion-induced fluorescence enhancement in acetonitrile, but not under physiological conditions. Electrochemical studies and theoretical calculations were used to assess and support the underlying mechanisms for the new ICT and PET 1,2,3-triazole fluoroionophores. KW - Charge transfer KW - Click chemistry KW - Electron transfer KW - Fluorescent probes KW - Metal ions PY - 2013 DO - https://doi.org/10.1002/chem.201201575 SN - 0947-6539 SN - 1521-3765 VL - 19 IS - 9 SP - 2990 EP - 3005 PB - Wiley-VCH Verl. CY - Weinheim AN - OPUS4-27742 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Bauer, L.J. A1 - Wieder, Frank A1 - Truong, V. A1 - Förste, F. A1 - Wagener, Y. A1 - Jonas, A. A1 - Praetz, S: A1 - Schlesiger, C. A1 - Kupsch, Andreas A1 - Müller, Bernd R. A1 - Kanngießer, B. A1 - Zaslansky, P. A1 - Mantouvalou, I. T1 - Absorption Correction for 3D Elemental Distributions of Dental Composite Materials Using Laboratory Confocal Micro-X-ray Fluorescence Spectroscopy N2 - Confocal micro-X-ray fluorescence (micro-XRF) spectroscopy facilitates three-dimensional (3D) elemental imaging of heterogeneous samples in the micrometer range. Laboratory setups using X-ray tube excitation render the method accessible for diverse research fields but interpretation of results and quantification remain challenging. The attenuation of X-rays in composites depends on the photon energy as well as on the composition and density of the material. For confocal micro-XRF, attenuation severely impacts elemental distribution information, as the signal from deeper layers is distorted by superficial layers. Absorption correction and quantification of fluorescence measurements in heterogeneous composite samples have so far not been reported. Here, an absorption correction approach for confocal micro-XRF combining density information from microcomputed tomography (micro-CT) data with laboratory X-ray absorption spectroscopy (XAS) and synchrotron transmission measurements is presented. The energy dependency of the probing volume is considered during the correction. The methodology is demonstrated on a model composite sample consisting of a bovine tooth with a clinically used restoration material. KW - Micro X-ray fluorescence spectroscopy KW - Dental composite materials KW - Computed tomography KW - Absorption correction PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-601630 DO - https://doi.org/10.1021/acs.analchem.4c00116 SN - 0003-2700 SN - 1520-6882 VL - 96 IS - 21 SP - 8441 EP - 8449 PB - American Chemical Society Publications CY - Washington, DC AN - OPUS4-60163 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Mühler, T. A1 - Helsch, G. A1 - Heinrich, J.G. A1 - Yao, Dongxu A1 - Gräf, S. A1 - Müller, F.A. A1 - Günster, Jens T1 - Strategies for the selective volume sintering of ceramics N2 - The present study is dealing with the basic physics for a novel way to generate a free-formed ceramic body, not like common layer by layer, but directly by Selective Volume Sintering (SVS) in a compact block of ceramic powder. To penetrate with laser light into the volume of a ceramic powder compact it is necessary to investigate the light scattering properties of ceramic powders. Compared with polymers and metals, ceramic materials are unique as they offer a wide optical window of transparency. The optical window typically ranges from below 0.3 up to 5 µm wave length. In the present study thin layers of quartz glass (SiO2) particles have been prepared. As a function of layer thickness and the particle size, transmission and reflection spectra in a wave length range between 0.5 and 2.5 µm have been recorded. Depending on the respective particle size and by choosing a proper relation between particle size and wave length of the incident laser radiation, it is found that light can penetrate a powder compact up to a depth of a few millimeters. With an adjustment of the light absorption properties of the compact the initiation of sintering in the volume of the compact is possible. KW - Additive Manufacturing PY - 2014 DO - https://doi.org/10.1557/jmr.2014.174 SN - 0884-2914 VL - 29 IS - 17 SP - 2095 EP - 2099 PB - Materials Research Society CY - Warrendale, Pa. AN - OPUS4-32544 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Wirth, Cynthia A1 - Müller, Ralf A1 - Günster, Jens A1 - Mühler, T. A1 - Görke, R. A1 - Heinrich, J.G. T1 - Submicrometer silica spheres generated by laser fuming N2 - The production of agglomerate-free SiO2 particles exhibiting a monomodal distribution of particle sizes of around 300 nm by means of direct laser fuming of micrometric SiO2 powders has been successfully demonstrated. With a 12 kW cw CO2 laser system, a production rate of up to 1 kilogram powder per hour was achieved. Almost ideal spherical amorphous SiO2 particles in a broad particle size distribution between 10 nm and several 100 nm (d50 ≈ 300 nm) were synthesized. Several observations suggest weak agglomeration forces between the particles. A temperature reduction of 200 °C for sintering powder compacts was observed. KW - Laser KW - SiO2 KW - Nanopowder PY - 2013 DO - https://doi.org/10.4416/JCST2012-00033 SN - 2190-9385 N1 - Geburtsname von Wirth, Cynthia: Gomes, C. M. - Birth name of Wirth, Cynthia: Gomes, C. M. VL - 4 IS - 1 SP - 11 EP - 18 PB - Göller CY - Baden-Baden AN - OPUS4-31423 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Maul, Ronald A1 - Müller, C. A1 - Rieß, Stephanie A1 - Koch, Matthias A1 - Methner, F.-J. A1 - Nehls, Irene T1 - Germination induces the glucosylation of the Fusarium mycotoxin deoxynivalenol in various grains N2 - In food, the mycotoxin deoxynivalenol (DON) often occurs in conjunction with its 3-β-D-glucopyranoside (D3G). The transformation of DON to D3G through glucosylation is catalysed by plant enzymes, however, the exact circumstances are not well understood. In order to investigate the role of enzymatic glucosylation in germinating grains, DON treated kernels were steeped and germinated under laboratory conditions. Furthermore, the effect of malting on the DON content of the contaminated barley was investigated. In all cases, DON and its derivatives were quantified by HPLC-MS/MS before, during and after the experiments. Amongst the six tested cereals; wheat, rye, barley, spelt, and millet transformed DON to D3G during germination whilst the oats were inactive. For wheat, barley, and spelt the initial DON content was reduced by 50%, with the loss being almost entirely accounted for by D3G formation. As D3G might be cleaved during digestion, the elevated D3G concentration may obscure the toxicologically relevant DON content in processed food and beer. The germination process has a major influence on the 'masking' of DON, leading to high quantities of D3G that may be missed in common mycotoxin analyses. KW - Mycotoxins KW - Masked mycotoxins KW - Deoxynivalenol (DON) KW - DON-3-glucoside KW - Acetyl-DON KW - Germination KW - Malting PY - 2012 DO - https://doi.org/10.1016/j.foodchem.2011.08.077 SN - 0308-8146 VL - 131 IS - 1 SP - 274 EP - 279 PB - Elsevier CY - Amsterdam [u.a.] ; Jena AN - OPUS4-25732 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -