TY - JOUR A1 - Wilke, M. A1 - Hahn, Oliver A1 - Woodland, A. B. A1 - Rickers, K. T1 - The oxidation state of iron determined by Fe K-edge XANES-application to iron gall ink in historical manuscripts N2 - Fe K-edge XANES measurements were performed to determine the oxidation state of iron in iron gall inks. These data are used to investigate the relationship between the Fe oxidation state and ink corrosion in historical manuscripts. The oxidation state is determined using the pre-edge based on a general variation trend that was derived from model compounds and validated here independently on a suite of samples with known oxidation state and Fe in octahedral coordination (i.e. similar to Fe in gall ink). As long as suitable references for the pure ferric and ferrous state of iron gall inks cannot be pointed out, the analysis of the pre-edge of the Fe K-edge represents the only way to acquire absolute values for the Fe oxidation state (Fe3+/Fetot) with spatial resolution for this usually non-crystalline compound. Fe3+/Fetot values for the ink samples vary between ca. 0.7 and 1.0. Spatially resolved analyses performed across ink strokes of various historical manuscripts as well as newly made samples did not reveal any systematic spatial dependence. On average, historical samples that were exposed to conservation treatments show a more oxidized state. However, the measurements demonstrate explicitly that the exposure to X-rays during the XANES acquisition affects the oxidation state of Fe in most iron gall inks. KW - Cultural heritage KW - Conservation science KW - Non-destructive testing KW - X-ray absorption spectroscopy PY - 2009 U6 - https://doi.org/10.1039/b904438h SN - 0267-9477 SN - 1364-5544 VL - 24 IS - - SP - 1364 EP - 1372 PB - Royal Society of Chemistry CY - London AN - OPUS4-19975 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Wilke, M. A1 - Hahn, Oliver A1 - Eggert, G. T1 - Corrosion of Cu on the surface of historic objects KW - Synchrotron infrared radiation KW - FTIR KW - Organic materials KW - Archaeometry KW - Cultural heritage PY - 2005 UR - http://www.helmholtz-berlin.de/media/media/oea/web/pr_webseite/druckschriften/berichte/bessy/annualreport2004.pdf#page=375 SN - 0179-4159 SP - 375 EP - 376 PB - Berliner Elektronenspeicherring-Gesellschaft für Synchrotronstrahlung CY - Berlin AN - OPUS4-7417 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Torge, Manfred A1 - Müller, Wolfgang A1 - Jann, Oliver A1 - Brödner, Doris A1 - Wilke, Olaf A1 - Pilz, M. T1 - Schadstoffbelastungen in Ausstellungsvitrinen und Simulation der Bedingungen im Labor T2 - 28. Jahrestagung der GUS CY - Pfinztal bei Karlsruhe, Deutschland DA - 1999-03-10 KW - Kulturguterhaltung KW - Umweltsimulation PY - 1999 SN - 3-9806167-3-8 SP - 16-1-16-14 CY - Pfinztal AN - OPUS4-3233 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Spallanzani, Roberta A1 - Koga, K. A1 - Cichy, S. A1 - Wiedenbeck, M. A1 - Schmidt, B. A1 - Oelze, Marcus A1 - Wilke, M. T1 - Lithium and boron difusivity and isotopic fractionation in hydrated rhyolitic melts N2 - Lithium and boron are trace components of magmas, released during exsolution of a gas phase during volcanic activity. In this study, we determine the difusivity and isotopic fractionation of Li and B in hydrous silicate melts. Two glasses were synthesized with the same rhyolitic composition (4.2 wt% water), having diferent Li and B contents; these were studied in difusion-couple experiments that were performed using an internally heated pressure vessel, operated at 300 MPa in the temperature range 700–1250 °C for durations from 0 s to 24 h. From this we determined activation energies for Li and B difusion of 57±4 kJ/mol and 152±15 kJ/mol with pre-exponential factors of 1.53 × 10–7 m2/s and 3.80× 10–8 m2 /s, respectively. Lithium isotopic fractionation during difusion gave β values between 0.15 and 0.20, whereas B showed no clear isotopic fractionation. Our Li difusivities and isotopic fractionation results difer somewhat from earlier published values, but overall confrm that Li difusivity increases with water content. Our results on B difusion show that similarly to Li, B mobility increases in the presence of water. By applying the Eyring relation, we confrm that B difusivity is limited by viscous fow in silicate melts. Our results on Li and B difusion present a new tool for understanding degassing-related processes, ofering a potential geospeedometer to measure volcanic ascent rates. KW - Hydrated silicate melts KW - Stable isotopes KW - Diffusion KW - Isotopic fractionation PY - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:b43-554496 VL - 177 IS - 8 SP - 1 EP - 17 PB - Springer AN - OPUS4-55449 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Sieber, M. J. A1 - Wilke, M. A1 - Appelt, O. A1 - Oelze, Marcus A1 - Koch-Müller, M. T1 - Melting relations of Ca–Mg carbonates and trace element signature of carbonate melts up to 9 GPa – A proxy for melting of carbonated mantle lithologies N2 - The most profound consequences of the presence of Ca–Mg carbonates (CaCO3–MgCO3) in the Earth’s upper mantle may be to lower the melting temperatures of the mantle and control the melt composition. Low-degree partial melting of a carbonate-bearing mantle produces CO2-rich, silica-poor melts compositionally imposed by the melting relations of carbonates. Thus, understanding the melting relations in the CaCO3–MgCO3 system facilitates the interpretation of natural carbonate-bearing silicate systems. We report the melting relations of the CaCO3–MgCO3 system and the partition coefficient of trace elements between carbonates and carbonate melt from experiments at high pressure (6 and 9 GPa) and temperature (1300–1800 ◦C) using a rocking multi-anvil press. In the absence of water, Ca–Mg carbonates are stable along geothermal gradients typical of subducting slabs. Ca–Mg carbonates (∼ Mg0.1–0.9Ca0.9–0.1CO3) partially melt beneath mid-ocean ridges and in plume settings. Ca–Mg carbonates melt incongruently, forming periclase crystals and carbonate melt between 4 and 9 GPa. Furthermore, we show that the rare earth element (REE) signature of Group-I kimberlites, namely strong REE fractionation and depletion of heavy REE relative to the primitive mantle, is resembled by carbonate melt in equilibrium with Ca-bearing magnesite and periclase at 6 and 9 GPa. This suggests that the dolomite–magnesite join of the CaCO3–MgCO3 system might be useful to approximate the REE signature of carbonate-rich melts parental to kimberlites. KW - High pressure experiments KW - Laser Ablation PY - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:b43-561197 SN - 0935-1221 VL - 34 IS - 5 SP - 411 EP - 424 PB - Copernicus Publications CY - Göttingen AN - OPUS4-56119 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Matoga, D. A1 - Roztocki, K. A1 - Wilke, Manuel A1 - Emmerling, Franziska A1 - Oszajca, M. A1 - Fitta, M. A1 - Bałanda, M. T1 - Crystalline bilayers unzipped and rezipped: solid-state reaction cycle of a metal–organic framework with triple rearrangement of intralayer bonds N2 - We present a series of remarkable structural transformations for a family of layered metal–organic frameworks (MOFs) in a three-step solid-state reaction cycle. The cycle represents new dynamic behavior of 2D coordination polymers and involves the sequence of reactions: {[Mn2(ina)4(H2O)2]·2EtOH}n (JUK-1) → {(NH4)2[Mn(ina)2(NCS)2]}n·xH2O (JUK-2) → {[Mn2(ina)2(Hina)2(NCS)2]}n (JUK-3) → JUK-1 (Hina = isonicotinic acid), each accompanied by rearrangement of intralayer coordination bonds and each induced by a different external stimulus. In situ investigation of the first step of the cycle by combined synchrotron X-ray diffraction and Raman spectroscopy reveals direct mechanochemical unzipping of JUK-1 bilayers to respective JUK-2 layers with reaction rates dependent on the milling conditions. In contrast, the reverse zipping of JUK-2 layers involves two steps and proceeds through a new MOF (JUK-3) whose structure was elucidated by powder X-ray diffraction. Magnetic measurements confirm conversions of manganese nodes in the reaction cycle. The findings indicate the possibility of developing coordination-based assemblies with large structural responses for use in smart stimuli-responsive systems and sensor technologies. KW - Mechanochemistry KW - In situ KW - XRD KW - MOF PY - 2017 UR - http://pubs.rsc.org/is/content/articlehtml/2017/ce/c7ce00655a U6 - https://doi.org/10.1039/C7CE00655A VL - 19 SP - 2987 EP - 2995 AN - OPUS4-41517 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Lucassen, F. A1 - Pritzkow, Wolfgang A1 - Rosner, M. A1 - Sepulveda, F. A1 - Vasquez, P. A1 - Wilke, H. A1 - Kasemann, S. A. T1 - The stable isotope composition of nitrogen and carbon and elemental contents in modern and fossil seabird guano from Northern Chile – Marine sources and diagenetic effects N2 - Seabird excrements (guano) have been preserved in the arid climate of Northern Chile since at least the Pliocene. The deposits of marine organic material in coastal areas potentially open a window into the present and past composition of the coastal ocean and its food web. We use the stable isotope composition of nitrogen and carbon as well as element contents to compare the principal prey of the birds, the Peruvian anchovy, with the composition of modern guano. We also investigate the impact of diagenetic changes on the isotopic composition and elemental contents of the pure ornithogenic sediments, starting with modern stratified deposits and extending to fossil guano. Where possible, 14C systematics is used for age information. The nitrogen and carbon isotopic composition of the marine prey (Peruvian anchovy) of the birds is complex as it shows strong systematic variations with latitude. The detailed study of a modern profile that represents a few years of guano deposition up to present reveals systematic changes in nitrogen and carbon isotopic composition towards heavier values that increase with age, i.e. depth. Only the uppermost, youngest layers of modern guano show compositional affinity to the prey of the birds. In the profile, the simultaneous loss of nitrogen and carbon occurs by degassing, and non-volatile elements like phosphorous and calcium are passively enriched in the residual guano. Fossil guano deposits are very low in nitrogen and low in carbon contents, and show very heavy nitrogen isotopic compositions. One result of the study is that the use of guano for tracing nitrogen and carbon isotopic and elemental composition in the marine food web of the birds is restricted to fresh material. Despite systematic changes during diagenesis, there is little promise to retrieve reliable values of marine nitrogen and carbon signatures from older guano. However, the changes in isotopic composition from primary marine nitrogen isotopic signatures towards very heavy values generate a compositionally unique material. These compositions trace the presence of guano in natural ecosystems and its use as fertilizer in present and past agriculture. KW - Isotope ratio KW - VPDB KW - Fishmeal KW - Elemental analyser KW - Vario EL III KW - Casein standard KW - ICP-OES KW - Accelerator mass spectrometry PY - 2017 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:b43-407911 SN - 1932-6203 VL - 12 IS - 6 SP - Article e0179440, 1 EP - 25 PB - PLOS CY - San Francisco, California, US AN - OPUS4-40791 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kaufmann, Jan Ole A1 - Brangsch, J. A1 - Kader, A. A1 - Saatz, Jessica A1 - Mangarova, D. B. A1 - Zacharias, M. A1 - Kempf, W. E. A1 - Schwaar, T. A1 - Wilke, Marco A1 - Adams, L. C. A1 - Möckel, J. A1 - Botnar, R. M. A1 - Taupitz, M. A1 - Mägdefessel, L. A1 - Traub, Heike A1 - Hamm, B. A1 - Weller, Michael G. A1 - Makowski, M. R. T1 - ADAMTS4-specific MR-probe to assess aortic aneurysms in vivo using synthetic peptide libraries N2 - The incidence of abdominal aortic aneurysms (AAAs) has substantially increased during the last 20 years and their rupture remains the third most common cause of sudden death in the cardiovascular field after myocardial infarction and stroke. The only established clinical parameter to assess AAAs is based on the aneurysm size. Novel biomarkers are needed to improve the assessment of the risk of rupture. ADAMTS4 (A Disintegrin And Metalloproteinase with ThromboSpondin motifs 4) is a strongly upregulated proteoglycan cleaving enzyme in the unstable course of AAAs. In the screening of a one-bead-one-compound library against ADAMTS4, a low-molecular-weight cyclic peptide is discovered with favorable properties for in vivo molecular magnetic resonance imaging applications. After identification and characterization, it’s potential is evaluated in an AAA mouse model. The ADAMTS4-specific probe enables the in vivo imaging-based prediction of aneurysm expansion and rupture. KW - Peptide KW - Peptide library KW - OBOC library KW - Combinatorial chemistry KW - Peptide aptamers KW - Binding molecule KW - Affinity KW - Synthetic peptides KW - Contrast agent KW - Magnetic resonance imaging KW - One-bead-one-compound library KW - On-chip screening KW - Lab-on-a-chip KW - MALDI-TOF MS KW - SPR KW - Surface plasmon resonance KW - Alanine scan KW - Fluorescence label KW - MST KW - Docking KW - Chelate PY - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:b43-560930 VL - 13 IS - 1 SP - 1 EP - 18 PB - Springer Nature Limited CY - Heidelberg AN - OPUS4-56093 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kanngießer, B. A1 - Hahn, Oliver A1 - Wilke, M. A1 - Nektat, B. A1 - Malzer, W. A1 - Erko, A. T1 - Investigation of oxidation and migration processes of inorganic compounds in ink-corroded manuscripts N2 - We studied the oxidation and migration processes of inorganic compounds in iron gall inks with a combination of micro X-ray fluorescence analysis (micro-XRF) and micro X-ray absorption near edge structure spectroscopy (micro-XANES). With elemental mapping by micro-XRF, the correlation of the minor elements in the ink to the major element Fe was investigated. Along concentration profiles of Fe, micro-XANES measurements were carried out in order to determine the oxidation state and the local environment. With the help of model inks, we could show that Cu is a further important element in the paper degradation process due to iron gall ink corrosion. KW - X-ray fluorescence analysis KW - X-ray absorption near edge structure spectroscopy KW - Archaeometry KW - Iron gall ink corrosion KW - Micro-XANES KW - Micro-XRF KW - Cultural heritage PY - 2004 U6 - https://doi.org/10.1016/j.sab.2004.07.013 SN - 0584-8547 SN - 0038-6987 VL - 59 IS - 10-11 SP - 1511 EP - 1516 PB - Elsevier CY - Amsterdam AN - OPUS4-4985 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kanngießer, B. A1 - Hahn, Oliver A1 - Wilke, M. A1 - Nekat, B. A1 - Malzer, W. A1 - Wolff, Timo A1 - Erko, A. T1 - X-ray fluorescence and X-ray absorption analysis of historical iron gall links T2 - Workshop: RICH - Research Infrastructures for Cultural Heritage CY - Trieste, Italy DA - 2005-12-12 PY - 2005 AN - OPUS4-10933 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -