TY - JOUR A1 - Rodrigues, M. A1 - Schreiner, M. A1 - Mäder, M. A1 - Melcher, M. A1 - Guerra, M. A1 - Salomon, J. A1 - Radtke, Martin A1 - Alram, M. A1 - Schindel, N. T1 - The hoard of Becin - non-destructive analysis of the silver coins N2 - We report the results of an analytical investigation on 416 silver-copper coins stemming from the Ottoman Empire (end of 16th and beginning of 17th centuries), using synchrotron micro X-ray fluorescence analysis (SRXRF). In the past, analyses had already been conducted with energy dispersive X-ray fluorescence analysis (EDXRF), scanning electron microscopy with energy dispersive X-ray spectrometry (SEM/EDX) and proton induced X-ray emission spectroscopy (PIXE).With this combination of techniques it was possible to confirm the fineness of the coinage as well as to study the provenance of the alloy used for the coins. For the interpretation of the data statistical analysis (principal component analysis—PCA) has been performed. A definite local assignment was explored and significant clustering was obtained regarding the minor and trace elements composing the coin alloys. KW - SRXRF KW - Silber KW - Archaeometrie PY - 2010 DO - https://doi.org/10.1007/s00339-010-5627-y SN - 0947-8396 VL - 99 IS - 2 SP - 351 EP - 356 PB - Springer CY - Berlin AN - OPUS4-23170 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Rodrigues, M. A1 - Schreiner, M. A1 - Melcher, M. A1 - Guerra, M. A1 - Salomon, J. A1 - Radtke, Martin A1 - Alram, M. A1 - Schindel, N. T1 - Characterization of the silver coins of the Hoard of Becin by x-ray based methods N2 - Four hundred sixteen silver coins stemming from the Ottoman Empire (16th and 17th centuries) were analyzed in order to confirm the fineness of the coinage as well as to study the provenance of the alloy used for the coins. As most of the coins showed the typical green patina on their surfaces due to corrosion processes which have led to the depletion of copper in the near-surface domains of the silver coins in comparison to their core composition, small samples by cutting splinters from the coins had to be taken, embedded in synthetic resin and cross-sectioned in order to investigate the true-heart metal composition. The type of the alloy was investigated as well as if coins minted in different locations demonstrated homogeneous traits concerning the predominant impurities which could suggest a common ore. Several X-ray based techniques (µ-XRF, µ-SRXRF and µ-PIXE) could be applied in order to determine the silver contents as well as the minor and trace elements. Finally, SEM/EDX was applied in order to study the homogeneity/heterogeneity of the coins and the presence of surface enrichments. In general, the silver content of the analyzed specimen varies between 90% and 95%. These outcomes have not supported the historical interpretations, which predict that during the period studied a debasement of approximately 44% of the silver content of the coins should have occurred. KW - PIXE KW - SRXRF KW - SEM/EDX KW - Silver coins PY - 2011 DO - https://doi.org/10.1016/j.nimb.2011.04.068 SN - 0168-583X SN - 1872-9584 VL - 269 IS - 24 SP - 3041 EP - 3045 PB - Elsevier B.V. CY - Amsterdam AN - OPUS4-25289 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Rodrigues, M. A1 - Schreiner, M. A1 - Melcher, M. A1 - Guerra, M. A1 - Salomon, J. A1 - Radtke, Martin A1 - Alram, M. A1 - Schindel, N. T1 - Analysis of the hoard of Becin using X-ray-based techniques N2 - Four hundred and sixteen silver coins stemming from the Ottoman Empire (16th and 17th centuries) were analyzed to confirm the fineness of the coinage as well as to study the provenance of the alloy used for the coins. As most of the coins showed the typical green patina on their surfaces due to corrosion processes that have led to the depletion of copper in the near surface domains of the silver coins in comparison to their core composition, small samples had to be taken, embedded in synthetic resin, and cross sectioned to investigate the true-heart metal composition. µ-synchrotron micro X-ray fluorescence analysis and µ-proton-induced X-ray emission were applied to determine the silver contents as well as the minor and trace elements. The type of the alloy was investigated as well as if coins minted in different locations demonstrated homogeneous traits concerning the predominant impurities (Au and Bi), which could suggest a common ore. Finally, energy-dispersive microanalysis in a scanning electron microscope was applied to study the homogeneity/heterogeneity of the coins and the presence of surface enrichments and to explain differences between the µ-synchrotron micro X-ray fluorescence analysis and µ-proton-induced X-ray emission measurements concerning the main component. In general, the silver content of the analyzed specimen varies between 90 and 95%. These outcomes have not supported the historical interpretations, which predict that during the period studied, a debasement of approximately 44% of the silver content of the coins should have occurred. KW - SRXRF KW - Silber KW - BAMline PY - 2012 DO - https://doi.org/10.1002/xrs.2415 SN - 0049-8246 VL - 41 IS - 6 SP - 416 EP - 424 PB - Wiley CY - Chichester AN - OPUS4-27723 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Schoknecht, Ute A1 - Fürhapper, C. A1 - Gunschera, J. A1 - Härtner, H. A1 - Hill, R. A1 - Melcher, E. A1 - Schwarz, G. A1 - Spetmann, P. A1 - Wilken, U. A1 - Wittenzellner, J. A1 - Wobst, M. T1 - Bestimmung von Permethrin in Holz - Ergebnisse von Vergleichsanalysen N2 - Vergleichsanalysen zur Bestimmung von Permethrin aus Holz ergaben, dass sich sowohl Extraktion mit Methanol im Ultraschallverfahren als auch Soxhlet-Extraktion mit Ethylacetat gut eignen, um Permethrin aus behandeltem Holz zu lösen. Verschiedene andere Extraktionsverfahren führen zu Minderbefunden. Zur quantitativen Bestimmung von Permethrin können sowohl Hochdruckflüssigchromatographie als auch Gaschromatographie eingesetzt werden. KW - Permethrin KW - Holz KW - Extraktion KW - Gaschromatographie KW - Hochdruckflüssigchromatographie KW - Analyse PY - 2008 DO - https://doi.org/10.1007/s00107-007-0208-2 SN - 0018-3768 VL - 66 IS - 1 SP - 57 EP - 61 PB - Springer CY - Berlin AN - OPUS4-17167 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Schoknecht, Ute A1 - Bornkessel, C. A1 - Fürhapper, C. A1 - Gunschera, J. A1 - Härtner, H. A1 - Hill, R. A1 - Kochan, J. A1 - Melcher, E. A1 - Wilken, U. A1 - Wittenzellner, J. A1 - Wobst, M. T1 - Bestimmung des Wirkstoffes Fenoxycarb in Holz mittels Hochdruckflüssigchromatographie N2 - Fenoxycarb ist ein insektizider Wirkstoff, der wegen seiner hormonähnlichen Wirkung in sehr geringen Konzentrationen in Holzschutzmitteln eingesetzt werden kann. Das hat zur Folge, dass aus Extrakten von behandeltem Holz relativ geringe Fenoxycarb-Mengen vor dem Hintergrund ebenfalls extrahierter Holzinhaltsstoffe zu bestimmen sind. In Vergleichsanalysen verschiedener Laboratorien wurde gezeigt, dass Fenoxycarb durch Methanol mit hoher Ausbeute aus Holz extrahierbar ist und in den Extrakten durch Hochdruckflüssigchromatographie in Kopplung mit UV-Detektion bestimmt werden kann. Fenoxycarb-Konzentrationen im unteren Bereich der erforderlichen Einbringmengen können mit dem erprobten Verfahren nur nach zusätzlicher Probenaufarbeitung bestimmt werden. Bedingt durch schwer auswertbare Chromatogramme sind die Abweichungen der Ergebnisse zwischen verschiedenen Laboratorien relativ hoch. KW - Analyse KW - Biozid KW - Fenoxycarb KW - Holz KW - Hochdruckflüssigchromatographie PY - 2010 UR - http://www.springerlink.com/content/67kjwv763p3l72g9/fulltext.pdf DO - https://doi.org/10.1007/s00107-009-0387-0 SN - 0018-3768 VL - 68 IS - 4 SP - 469 EP - 474 PB - Springer CY - Berlin ; Heidelberg AN - OPUS4-20669 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Chi, Jinchun A1 - Zocca, Andrea A1 - Agea Blanco, Boris A1 - Melcher, J. A1 - Sparenberg, M. A1 - Günster, Jens T1 - 3D Printing of Self-Organizing Structural Elements for Advanced Functional Structures N2 - A shape evolution approach based on the thermally activated self-organization of 3D printed parts into minimal surface area structures is presented. With this strategy, the present communication opposes currently established additive manufacturing strategies aiming to stipulate each individual volumetric element (voxel) of a part. Instead, a 3D structure is roughly defined in a 3D printing process, with all its advantages, and an externally triggered self-organization allows the formation of structural elements with a definition greatly exceeding the volumetric resolution of the printing process. For enabling the self-organization of printed objects by viscous flow of material, functionally graded structures are printed as rigid frame and melting filler. This approach uniquely combines the freedom in design, provided by 3D printing, with the mathematical formulation of minimal surface structures and the knowledge of the physical potentials governing self-organization, to overcome the paradigm which strictly orrelates the geometrical definition of 3D printed parts to the volumetric resolution of the printing process. Moreover, a transient liquid phase allows local programming of functionalities, such as the alignment of functional particles, by means of electric or magnetic fields. KW - Additive Manufacturing KW - Self-Assembly KW - 3D-Printing KW - Polymeric Materials PY - 2018 DO - https://doi.org/10.1002/admt.201800003 SN - 2365-709X VL - 3 IS - 5 SP - 1800003-1 EP - 1800003-7 PB - Wiley-VCH CY - Weinheim AN - OPUS4-45714 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Schoknecht, Ute A1 - Drescher, P. A1 - Fischer, M. A1 - Fürhapper, C. A1 - Gunschera, J. A1 - Hill, R. A1 - Melcher, E. A1 - Wegner, R. A1 - Wilken, U. A1 - Wittenzellner, J. T1 - Suitability of analytical methods to determine tebuconazole, propiconazole and permethrin in aged wood samples N2 - The suitability of common analytical methods for the determination of active substances from wood preservatives in aged wood samples was investigated during an interlaboratory study. Permethrin, propiconazole and tebuconazole were quantified in 1.5 and 8 year-old wood samples by gas chromatography and liquid chromatography. Generally, the applied Methods yielded reliable results for these samples. However, wood components can coelute with propiconazole and tebuconazole during liquid chromatography. Optimization of separation might be required if UV detection is applied. KW - Wood samples KW - Biocides KW - Analytical methods PY - 2020 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-503959 DO - https://doi.org/10.1007/s00107-020-01496-y VL - 78 IS - 2 SP - 271 EP - 279 PB - Springer CY - Heidelberg AN - OPUS4-50395 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Zocca, Andrea A1 - Lüchtenborg, Jörg A1 - Mühler, T. A1 - Wilbig, Janka A1 - Mohr, Gunther A1 - Villatte, T. A1 - Léonard, Fabien A1 - Nolze, Gert A1 - Sparenberg, M. A1 - Melcher, J. A1 - Hilgenberg, Kai A1 - Günster, Jens T1 - Enabling the 3D Printing of Metal Components in μ-Gravity N2 - As humanity contemplates manned missions to Mars, strategies need to be developed for the design and operation of hospitable environments to safely work in space for years. The supply of spare parts for repair and replacement of lost equipment will be one key need, but in-space manufacturing remains the only option for a timely supply. With high flexibility in design and the ability to manufacture ready-to-use components directly from a computeraided model, additive manufacturing (AM) technologies appear extremely attractive. For the manufacturing of metal parts, laser-beam melting is the most widely used AM process. However, the handling of metal powders in the absence of gravity is one prerequisite for its successful application in space. A gas flow throughout the powder bed is successfully applied to compensate for missing gravitational forces in microgravity experiments. This so-called gas-flow-assisted powder deposition is based on a porous Building platform acting as a filter for the fixation of metal particles in a gas flow driven by a pressure difference maintained by a vacuum pump. KW - Additive manufacturing KW - µ-gravity KW - Laser beam melting KW - Parabolic flight KW - 3D printing PY - 2019 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-492190 DO - https://doi.org/10.1002/admt.201900506 SP - 1900506 PB - WILEY-VCH Verlag GmbH AN - OPUS4-49219 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -