TY - JOUR A1 - Rhode, Michael A1 - Schaupp, Thomas A1 - Münster, C. A1 - Mente, Tobias A1 - Kannengießer, Thomas A1 - Böllinghaus, Thomas T1 - Hydrogen determination in welded specimens by carrier gas hot extraction - a review on the main parameters and their effects on hydrogen measurement N2 - Carrier gas hot extraction (CGHE) is a commonly applied technique for determination of hydrogen in weld joints using a thermal conductivity detector (TCD) for hydrogen measurement. The CGHE is based on the accelerated hydrogen effusion due to thermal activation at elevated temperatures. The ISO 3690 standard suggests different specimen geometries as well as necessary minimum extraction time vs. temperature. They have the biggest influence on precise hydrogen determination. The present study summarizes the results and experience of numerous test runs with different specimen temperatures, geometries (ISO 3690 type B and small cylindrical samples), and factors that additionally influence hydrogen determination. They are namely specimen surface (polished/as-welded), limited TCD sensitivity vs. specimen volume, temperature measurement vs. effects of PI-furnace controller, as well as errors due to insufficient data assessment. Summarized, the temperature is the driving force of the CGHE. Two different methods are suggested to increase the heating rate up to the desired extraction temperature without changing the experimental equipment. Suggestions are made to improve the reliability of hydrogen determination depended on the hydrogen signal stability during extraction accompanied by Evaluation of the recorded data. Generally, independent temperature measurement with dummy specimens is useful for further data analysis, especially if this data is used for calculation of trapping kinetics by thermal desorption analysis (TDA). KW - Hydrogen KW - Carrier gas hot extraction KW - Experimental design KW - Thermal conductivity device PY - 2019 DO - https://doi.org/10.1007/s40194-018-0664-9 SN - 0043-2288 VL - 63 IS - 2 SP - 511 EP - 526 PB - Springer CY - Berlin, Heidelberg AN - OPUS4-47603 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Abou-Ras, D. A1 - Caballero, R. A1 - Fischer, C.-H. A1 - Kaufmann, C.A. A1 - Lauermann, I. A1 - Mainz, R. A1 - Mönig, H. A1 - Schöpke, A. A1 - Stephan, C. A1 - Streeck, C. A1 - Schorr, S. A1 - Eicke, A. A1 - Döbeli, M. A1 - Gade, B. A1 - Hinrichs, J. A1 - Nunney, T. A1 - Dijkstra, H. A1 - Hoffmann, V. A1 - Klemm, D. A1 - Efimova, V. A1 - Bergmaier, A. A1 - Dollinger, G. A1 - Wirth, Thomas A1 - Unger, Wolfgang A1 - Rockett, A.A. A1 - Perez-Rodriguez, A. A1 - Alvarez-Garcia, J. A1 - Izquierdo-Roca, V. A1 - Schmid, T. A1 - Choi, P.-P. A1 - Müller, M. A1 - Bertram, F. A1 - Christen, J. A1 - Khatri, H. A1 - Collins, R.W. A1 - Marsillac, S. A1 - Kötschau, I. T1 - Comprehensive comparison of various techniques for the analysis of elemental distributions in thin films N2 - The present work shows results on elemental distribution analyses in Cu(In,Ga)Se2 thin films for solar cells performed by use of wavelength-dispersive and energy-dispersive X-ray spectrometry (EDX) in a scanning electron microscope, EDX in a transmission electron microscope, X-ray photoelectron, angle-dependent soft X-ray emission, secondary ion-mass (SIMS), time-of-flight SIMS, sputtered neutral mass, glow-discharge optical emission and glow-discharge mass, Auger electron, and Rutherford backscattering spectrometry, by use of scanning Auger electron microscopy, Raman depth profiling, and Raman mapping, as well as by use of elastic recoil detection analysis, grazing-incidence X-ray and electron backscatter diffraction, and grazing-incidence X-ray fluorescence analysis. The Cu(In,Ga)Se2 thin films used for the present comparison were produced during the same identical deposition run and exhibit thicknesses of about 2 µm. The analysis techniques were compared with respect to their spatial and depth resolutions, measuring speeds, availabilities, and detection limits. KW - Elemental distributions KW - Comparison KW - Depth profiling KW - Chemical mapping KW - Thin films KW - Solar cells KW - Chalcopyrite-type KW - Cu(In,Ga)Se2 PY - 2011 DO - https://doi.org/10.1017/S1431927611000523 SN - 1431-9276 SN - 1435-8115 VL - 17 IS - 5 SP - 728 EP - 751 PB - Cambridge University Press CY - New York, NY AN - OPUS4-24506 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kim, K. J. A1 - Kim, A. S. A1 - Jang, J. S. A1 - Suh, J. K. A1 - Wirth, Thomas A1 - Hodoroaba, Vasile-Dan A1 - Unger, Wolfgang A1 - Araujo, J. R. A1 - Archanjo, B. S. A1 - Galhardo, C. E. A1 - Damasceno, J. A1 - Achete, C. A. A1 - Wang, H. A1 - Wang, M. A1 - Bennett, J. A1 - Simons, D. A1 - Kurokawa, A. A1 - Terauchi, S. A1 - Fujimoto, T. A1 - Streeck, C. A1 - Beckhoff, B. A1 - Spencer, S. A1 - Shard, A. T1 - Measurement of mole fractions of Cu, In, Ga and Se in Cu(In,Ga)Se2 films N2 - CCQM key comparison K-129 for the quantitative analysis of Cu(In,Ga)Se2 (CIGS) films has been performed by the Surface Analysis Working Group (SAWG) of the Consultative Committee for Amount of Substance (CCQM). The objective of this key comparison is to compare the equivalency of the National Metrology Institutes (NMIs) and Designated Institutes (DIs) for the measurement of mole fractions of Cu, In, Ga and Se in a thin CIGS film. The measurand of this key comparison is the average mole fractions of Cu, In, Ga and Se of a test CIGS alloy film in the unit of mole fraction (mol/mol). Mole fraction with the metrological unit of mol/mol can be practically converted to atomic fraction with the unit of at%. In this key comparison, a CIGS film with certified mole fractions was supplied as a reference specimen to determine the relative sensitivity factors (RSFs) of Cu, In, Ga and Se. The mole fractions of the reference specimen were certified by isotope dilution - inductively coupled plasma/mass spectrometry (ID-ICP/MS) and are traceable to the SI. A total number counting (TNC) method was recommended as a method to determine the signal intensities of the constituent elements acquired in the depth profiles by Secondary Ion Mass Spectrometry (SIMS), X-ray Photoelectron Spectroscopy (XPS) and Auger Electron Spectroscopy (AES). Seven NMIs and one DI participated in this key comparison. The mole fractions of the CIGS films were measured by depth profiling based-SIMS, AES and XPS. The mole fractions were also measured by non-destructive X-Ray Fluorescence (XRF) Analysis and Electron Probe Micro Analysis (EPMA) with Energy Dispersive X-ray Spectrometry (EDX). In this key comparison, the average degrees of equivalence uncertainties for Cu, In, Ga and Se are 0.0093 mol/mol, 0.0123 mol/mol, 0.0047 mol/mol and 0.0228 mol/mol, respectively. These values are much smaller than that of Fe in a Fe-Ni alloy film in CCQM K-67 (0.0330 mol/mol). This means that the quantification of multi-element alloy films is possible by depth profiling analysis using the TNC method. KW - CIGS KW - Key comparison KW - CCQM KW - SIMS KW - XPS KW - AES KW - XRF KW - EPMA PY - 2016 UR - http://iopscience.iop.org/article/10.1088/0026-1394/53/1A/08011 DO - https://doi.org/10.1088/0026-1394/53/1A/08011 SN - 0026-1394 SN - 1681-7575 VL - 53, Technical Supplement SP - Article 08011, 1 EP - 19 PB - IOP Publishing AN - OPUS4-38110 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kim, K.J. A1 - Jang, J. S. A1 - Kim, A. S. A1 - Suh, J.K. A1 - Chung, Y.-D. A1 - Hodoroaba, Vasile-Dan A1 - Wirth, Thomas A1 - Unger, Wolfgang A1 - Kang, H. J. A1 - Popov, O. A1 - Popov, I. A1 - Kuselman, I. A1 - Lee, Y. H. A1 - Sykes, D. E. A1 - Wang, M. A1 - Wang, H. A1 - Ogiwara, T. A1 - Nishio, M. A1 - Tanuma, S. A1 - Simons, D. A1 - Szakal, C. A1 - Osborn, W. A1 - Terauchi, S. A1 - Ito, M. A1 - Kurokawa, A. A1 - Fujiimoto, T. A1 - Jordaan, W. A1 - Jeong, C. S. A1 - Havelund, R. A1 - Spencer, S. A1 - Shard, A. A1 - Streeck, C. A1 - Beckhoff, B. A1 - Eicke, A. A1 - Terborg, R. T1 - CCQM pilot study P-140: Quantitative surface analysis of multi-element alloy films N2 - A pilot study for the quantitative surface analysis of multi-element alloy films has been performed by the Surface Analysis Working Group (SAWG) of the Consultative Committee for Amount of Substance (CCQM). The aim of this pilot study is to ensure the equivalency in the measurement capability of national metrology institutes for the quantification of multi-element alloy films. A Cu(In,Ga)Se2 (CIGS) film with non-uniform depth distribution was chosen as a representative multi-element alloy film. The atomic fractions of the reference and the test CIGS films were certified by isotope dilution - inductively coupled plasma/mass spectrometry. A total number counting (TNC) method was used as a method to determine the signal intensities of the constituent elements, which are compared with their certified atomic fractions. The atomic fractions of the CIGS films were measured by various methods, such as Secondary Ion Mass Spectrometry (SIMS), Auger Electron Spectroscopy (AES), X-ray Photoelectron Spectroscopy (XPS), X-Ray Fluorescence (XRF) analysis and Electron Probe Micro Analysis (EPMA) with Energy Dispersive X-ray Spectrometry (EDX). Fifteen laboratories from eight National Metrology Institutes (NMIs), one Designated Institute (DI) and six non-NMIs participated in this pilot study. Although the average atomic fractions of 18 data sets showed rather poor relative standard deviations of about 5.5 % to 6.8 %, they were greatly improved to about 1.5 % to 2.2 % by excluding 5 strongly deviating data sets from the average atomic fractions. In this pilot study, the average expanded uncertainties of SIMS, XPS, AES, XRF and EPMA were 3.84%, 3.68%, 3.81%, 2.88% and 2.90%, respectively. These values are much better than those in the key comparison K-67 for composition of a Fe-Ni alloy film. As a result, the quantification of CIGS films using the TNC method was found to be a good candidate as a subject for a CCQM key comparison. KW - CCQM KW - Pilot study KW - Surface analysis KW - Alloy films KW - CIGS PY - 2015 DO - https://doi.org/10.1088/0026-1394/52/1A/08017 SN - 0026-1394 SN - 1681-7575 VL - 52 IS - Technical Supplement SP - Article 08017 PB - Inst. of Physics Publ. CY - Bristol AN - OPUS4-35306 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kasper, J. A1 - Hermanns, M.I. A1 - Bantz, C. A1 - Koshkina, Olga A1 - Lang, Thomas A1 - Maskos, Michael A1 - Pohl, C. A1 - Unger, R. E. A1 - Kirkpatrick, C.J. T1 - Interactions of silica nanoparticles with lung epithelial cells and the association to flotillins N2 - Amorphous silica nanoparticles (aSNPs) gain increasing popularity for industrial and therapeutic claims. The lung with its surface area of 1006#8211;140 m² displays an ideal target for therapeutic approaches, but it represents also a serious area of attack for harmful nanomaterials. The exact nature of the cytotoxic effects of NPs is still unknown. Furthermore, cellular pathways and the destiny of internalized NPs are still poorly understood. Therefore, we examined the cytotoxicity (MTS, LDH) and inflammatory responses (IL-8) for different-sized aSNPs (30, 70, 300 nm) on our lung epithelial cells line NCI H441 and endothelial cell line ISO-HAS-1. Additionally, colocalization studies have been conducted via immunofluorescence staining for flotillin-1- and flotillin-2-bearing endocytic vesicles. Subsequently, the relevance of flotillins concerning the viability of aSNP-exposed epithelial cells has been evaluated using flotillin-1/2 depleted cells (siRNA). This study reveals the relevance of the nanoparticle size regarding cytotoxicity (MTS, LDH) and inflammatory responses (IL-8), whereat the smaller the size of the nanoparticle is, the more harmful are the effects. All different aSNP sizes have been incorporated in flotillin-1- and flotillin-2-labelled vesicles in lung epithelial and endothelial cells, which display a marker for late endosomal or lysosomal structures and appear to exhibit a clathrin- or caveolae-independent mode of endocytosis. Flotillin-depleted H441 showed a clearly decreased uptake of aSNPs. Additionally, the viability of aSNP-exposed cells was reduced in these cells. These findings indicate a contribution of flotillins in as yet unknown (clathrin or caveolae-independent) endocytosis mechanisms and (or) endosomal storage. KW - Silica nanoparticles KW - Alveolar-capillary barrier KW - Lung epithelial cells KW - Endothelial cells KW - Endocytosis KW - Flotillin-1 KW - Flotillin-2 KW - Cytotoxicity KW - Inflammatory response PY - 2012 UR - http://link.springer.com/content/pdf/10.1007%2Fs00204-012-0876-5 DO - https://doi.org/10.1007/s00204-012-0876-5 SN - 0340-5761 SN - 1432-0738 SP - 1 EP - 13(?) PB - Springer CY - Berlin ; Heidelberg [u.a.] AN - OPUS4-26195 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Belsey, N. A. A1 - Cant, D. J. H. A1 - Minelli, C. A1 - Araujo, J. R. A1 - Bock, B. A1 - Brüner, P. A1 - Castner, D. G. A1 - Ceccone, G. A1 - Counsell, J. D. P. A1 - Dietrich, Paul M. A1 - Engelhardt, M. H. A1 - Fearn, S. A1 - Galhardo, C. E. A1 - Kalbe, H. A1 - Kim, J. W. A1 - Lartundo-Rojas, L. A1 - Luftman, H. S. A1 - Nunney, T. S. A1 - Pseiner, J. A1 - Smith, E. F. A1 - Spampinato, V. A1 - Sturm, J. M. A1 - Thomas, A. G. A1 - Treacy, J. P. W. A1 - Veith, L. A1 - Wagstaffe, M. A1 - Wang, H. A1 - Wang, M. A1 - Wang, Y.-C. A1 - Werner, W. A1 - Yang, L. A1 - Shard, A. G. T1 - Versailles Project on Advanced Materials and Standards Interlaboratory Study on Measuring the Thickness and Chemistry of Nanoparticle Coatings Using XPS and LEIS N2 - We report the results of a Versailles Project on Advanced Materials and Standards (VAMAS) interlaboratory study on the measurement of the shell thickness and chemistry of nanoparticle coatings. Peptide-coated gold particles were supplied to laboratories in two forms: a colloidal suspension in pure water and particles dried onto a silicon wafer. Participants prepared and analyzed these samples using either X-ray photoelectron spectroscopy (XPS) or low energy ion scattering (LEIS). Careful data analysis revealed some significant sources of discrepancy, particularly for XPS. Degradation during transportation, storage, or sample preparation resulted in a variability in thickness of 53%. The calculation method chosen by XPS participants contributed a variability of 67%. However, variability of 12% was achieved for the samples deposited using a single method and by choosing photoelectron peaks that were not adversely affected by instrumental transmission effects. The study identified a need for more consistency in instrumental transmission functions and relative sensitivity factors since this contributed a variability of 33%. The results from the LEIS participants were more consistent, with variability of less than 10% in thickness, and this is mostly due to a common method of data analysis. The calculation was performed using a model developed for uniform, flat films, and some participants employed a correction factor to account for the sample geometry, which appears warranted based upon a simulation of LEIS data from one of the participants and comparison to the XPS results. KW - VAMAS KW - Interlaboratory Study KW - Nanoparticle coating KW - XPS KW - LEIS KW - shell thicknss and chemistry PY - 2016 UR - http://pubs.acs.org/doi/pdf/10.1021/acs.jpcc.6b06713 DO - https://doi.org/10.1021/acs.jpcc.6b06713 IS - 120 SP - 24070 EP - 24079 PB - ACS Publications AN - OPUS4-38428 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Richter, S. A1 - Traulsen, C. H.-H. A1 - Heinrich, Thomas A1 - Poppenberg, J. A1 - Leppich, C. A1 - Holzweber, Markus A1 - Unger, Wolfgang A1 - Schalley, C.A. T1 - Sequence-programmable multicomponent multilayers of nanometer-sized tetralactam macrocycles on gold surfaces N2 - Multicomponent multilayers have been deposited on gold surfaces by metal-ion-mediated layer-by-layer self-assembly of differently functionalized tetralactam macrocycles. The layer stack can be programmed with respect to the sequences of metal ions and macrocycles by the deposition sequence. KW - Organic layer KW - XPS KW - SIMS KW - NEXAFS PY - 2013 DO - https://doi.org/10.1021/jp405492v SN - 1932-7447 SN - 1089-5639 VL - 117 IS - 37 SP - 18980 EP - 18985 PB - Soc. CY - Washington, DC AN - OPUS4-32576 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Böllinghaus, Thomas A1 - Kannengießer, Thomas A1 - Jochum, C. A1 - Stiebe-Springer, I. T1 - Effect of filler material selection on stress strain build up and stress corrosion cracking resistance of welded supermartensitic stainless steel pipes T2 - Corrosion 2002 CY - Denver, CO, USA DA - 2002-04-07 KW - Supermartensitic stainless steel KW - Filler material KW - Orbital TIG welding KW - Duplex stainless steel KW - Hydrogen assisted cracking KW - Stress strain distribution KW - Shrinkage restraint KW - Formation water PY - 2002 SP - Paper 02061, 1 EP - 20 PB - NACE International CY - Houston, Tex. AN - OPUS4-1794 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Österle, Werner A1 - Deutsch, Cornelius A1 - Dörfel, Ilona A1 - Gradt, Thomas A1 - Häusler, Ines A1 - Orts-Gil, G. A1 - Prietzel, C. A1 - Schneider, Thomas T1 - Final outcome of a fundamental research project on tribofilms formed during automotive braking, Part 1: Experimental studies N2 - In order to obtain a better understanding of the role of tribofilms during automotive braking, their structures were investigated and the essential features identified. Next, different ingredient combinations were studied by preparing some model materials with simpler compositions than real tribofilms. A test method was developed for verifying the tribological properties of the model materials and for comparison with results obtained with numerical sliding simulations of such structures. Prerequisites of good brake Performance properties were identified. Although the coefficient of friction could be varied in a wide ränge, smooth sliding conditions could only be achieved with values smaller than 0.4. Tests with artificial third body powders turned out to be useful as screening method for the selection of raw materials for brake pad formulations. T2 - EuroBrake 2014 CY - Lille, France DA - 13.05.2014 KW - Tribofilm KW - Third body KW - Pad ingredients KW - Ball milling KW - Pin-on-disc test PY - 2014 SN - 978-0-9572076-4-6 SP - 1 EP - 8 PB - FISITA CY - London AN - OPUS4-35039 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Schröpfer, Dirk A1 - Kromm, Arne A1 - Lausch, Thomas A1 - Rhode, Michael A1 - Wimpory, R. C. A1 - Kannengießer, Thomas T1 - Influence of welding stresses on relief cracking during heat treatment of a creep-resistant 13CrMoV steel: Part III - Assessment of residual stresses from small-scale to real component welds N2 - For higher operational temperatures and pressures required in petrochemical plants, the modified 13CrMoV9-10 steel was developed providing high resistance against creep and compressed hydrogen. Extreme care during the welding procedure is necessary for this steel, attributed to low toughness, high strength in as-welded state, and increased susceptibility to stress relief cracking (SRC) during post-weld heat treatment (PWHT). Previous research of SRC in creep-resistant steels discussed mainly thermal and metallurgical factors. Few previous findings addressed the influences of welding procedure on crack formation during PWHT considering real-life manufacturing conditions. These investigations focus on effects of welding heat control on stresses during welding and subsequent PWHT operations close to realistic restraint and heat dissipation conditions using a special 3D testing facility, which was presented in parts I and II of this contribution. Part III addresses investigations on residual stress evolution affecting crack formation and discusses the transferability of results from large-scale testing to laboratory-scale. Experiments with test set-ups at different scales under diverse rigidity conditions and an assessment of the residual stresses of the weld-specimens using X-ray (surface near) and neutron diffraction analysis (bulk) were performed. This study aims to provide a way of investigating the SRC behaviour considering component-specific residual stresses via small-scale testing concepts instead of expensive weld mock-ups. KW - Welding KW - Creep-resistant steel KW - Residual stresses KW - Post-weld heat treatment KW - Stress relief cracking PY - 2021 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-524403 DO - https://doi.org/10.1007/s40194-021-01101-7 SN - 1878-6669 VL - 65 SP - 1671 EP - 1685 PB - Springer CY - Berlin AN - OPUS4-52440 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Seah, M.P. A1 - Spencer, S.J. A1 - Bensebaa, F. A1 - Vickridge, I. A1 - Danzebrink, H. A1 - Krumrey, M. A1 - Gross, Thomas A1 - Österle, Werner A1 - Wendler, E. A1 - Rheinländer, B. A1 - Azuma, Y. A1 - Kojima, I. A1 - Suzuki, N. A1 - Suzuki, M. A1 - Tanuma, S. A1 - Moon, D.W. A1 - Lee, H.J. A1 - Cho, H.M. A1 - Chen, H.Y. A1 - Wee, A. T. S. A1 - Osipowicz, T. A1 - Pan, J.S. A1 - Jordaan, W.A. A1 - Hauert, R. A1 - Klotz, U. A1 - van der Marel, C. A1 - Verheijen, M. A1 - Tamminga, Y. A1 - Jeynes, C. A1 - Bailey, P. A1 - Biswas, S. A1 - Falke, U. A1 - Nguyen, N.V. A1 - Chandler-Horowitz, D. A1 - Ehrstein, J.R. A1 - Muller, D. A1 - Dura, J.A. T1 - Critical review of the current status of thickness measurements for ultrathin SiO2 on Si - Part V: Results of a CCQM pilot study N2 - Results are reported from a pilot study under the Consultative Committee for Amount of Substance (CCQM) to compare measurements of and resolve any relevant measurement issues in, the amount of thermal SiO2 oxide on (100) and (111) orientation Si wafer substrates in the thickness range 1.5 - 8 nm. As a result of the invitation to participate in this activity, 45 sets of measurements have been made in different laboratories using 10 analytical methods: medium-energy ion scattering spectrometry (MEIS), nuclear reaction analysis (NRA), RBS, elastic backscattering spectrometry (EBS), XPS, SIMS, ellipsometry, grazing-incidence x-ray reflectrometry (GIXRR), neutron reflectometry and transmission electron microscopy (TEM). The measurements are made on separate sets of 10 carefully prepared samples, all of which have been characterised by a combination of ellipsometry and XPS using carefully established reference conditions and reference parameters. The results have been assessed against the National Physical Laboratory (NPL) data and all show excellent linearity. The remaining data sets correlate with the NPL data with average root-mean-square scatters of 0.15 nm, half being better than 0.1 nm and a few at or better than 0.05 nm. Each set of data allows a relative scaling constant and a zero thickness offset to be determined. Each method has an inherent zero thickness offset between 0 nm and 1 nm and it is these offsets, measured here for the first time, that have caused many problems in the past. There are three basic classes of offset: water and carbonadeous contamination equivalent to ~1 nm as seen by ellipsometry; adsorbed oxygen mainly from water at an equivalent thickness of 0.5 nm as seen by MEIS, NRA, RBS and possibly GIXRR; and no offset as seen by XPS using the Si 2p peaks. Each technique has a different uncertainty for the scaling constant and consistent results have been achieved. X-Ray photoelectron spectroscopy has large uncertainties for the scaling constant but a high precision and, critically, if used correctly, has zero offset. Thus, a combination of XPS and the other methods allows the XPS scaling constant to be determined with low uncertainty, traceable via the other methods. XPS laboratories returning results early were invited to test a new reference procedure. All showed very significant improvements. The reference attenuation lengths thus need scaling by 0.986 ± 0.009 (at an expansion factor of 2) deduced from the data for the other methods. Several other methods have small offsets and, to the extent that these can be shown to be constant or measurable, then these methods will also show low uncertainty. Recommendations are provided for parameters for XPS, MEIS, RBS and NRA to improve their accuracy. KW - Calibration KW - Ellipsometry KW - GIXRR KW - Interlaboratory study KW - MEIS KW - Neutron reflectometry KW - NRA KW - RBS KW - Silicon dioxide KW - SIMS KW - XPS PY - 2004 DO - https://doi.org/10.1002/sia.1909 SN - 0142-2421 SN - 1096-9918 VL - 36 IS - 9 SP - 1269 EP - 1303 PB - Wiley CY - Chichester AN - OPUS4-5549 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - RPRT A1 - Seah, M.P. A1 - Spencer, S.J. A1 - Bensebaa, F. A1 - Vickridge, I. A1 - Danzebrink, H. A1 - Krumrey, M. A1 - Gross, Thomas A1 - Österle, Werner A1 - Wendler, E. A1 - Rheinländer, B. A1 - Azuma, Y. A1 - Kojima, I. A1 - Suzuki, N. A1 - Suzuki, M. A1 - Tanuma, S. A1 - Moon, D.W. A1 - Lee, H.J. A1 - Cho, H.M. A1 - Chen, H.Y. A1 - Wee, A. T. S. A1 - Osipowicz, T. A1 - Pan, J.S. A1 - Jordaan, W.A. A1 - Hauert, R. A1 - Klotz, U. A1 - van der Marel, C. A1 - Verheijen, M. A1 - Tamminga, Y. A1 - Jeynes, C. A1 - Bailey, P. A1 - Biswas, S. A1 - Falke, U. A1 - Nguyen, N.V. A1 - Chandler-Horowitz, D. A1 - Ehrstein, J.R. A1 - Muller, D. A1 - Dura, J.A. T1 - Ultra-thin SiO2 on Si, Part V: Results of a CCQM Pilot Study of Thickness Measurements KW - SiO2 KW - Thin films KW - Thickness KW - XPS KW - Ellipsometry KW - TEM PY - 2003 SN - 1473-2734 SP - 57 pages AN - OPUS4-4118 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Koshkina, Olga A1 - Westmeier, D. A1 - Lang, Thomas A1 - Bantz, C. A1 - Hahlbrock, A. A1 - Würth, Christian A1 - Resch-Genger, Ute A1 - Braun, Ulrike A1 - Thiermann, Raphael A1 - Weise, C. A1 - Eravci, M. A1 - Mohr, B. A1 - Schlaad, H. A1 - Stauber, R. H. A1 - Docter, D. A1 - Bertin, Annabelle A1 - Maskos, M. T1 - Tuning the surface of nanoparticles: Impact of poly(2-ethyl-2-oxazoline) on protein adsorption in serum and cellular uptake N2 - Due to the adsorption of biomolecules, the control of the biodistribution of nanoparticles is still one of the major challenges of nanomedicine. Poly(2-ethyl-2-oxazoline) (PEtOx) for surface modification of nanoparticles is applied and both protein adsorption and cellular uptake of PEtOxylated nanoparticles versus nanoparticles coated with poly(ethylene glycol) (PEG) and non-coated positively and negatively charged nanoparticles are compared. Therefore, fluorescent poly(organosiloxane) nanoparticles of 15 nm radius are synthesized, which are used as a scaffold for surface modification in a grafting onto approach. With multi-angle dynamic light scattering, asymmetrical flow field-flow fractionation, gel electrophoresis, and liquid chromatography-mass spectrometry, it is demonstrated that protein adsorption on PEtOxylated nanoparticles is extremely low, similar as on PEGylated nanoparticles. Moreover, quantitative microscopy reveals that PEtOxylation significantly reduces the non-specific cellular uptake, particularly by macrophage-like cells. Collectively, studies demonstrate that PEtOx is a very effective alternative to PEG for stealth modification of the surface of nanoparticles. KW - Poloxazolines KW - Protein corona KW - Cellular uptake PY - 2016 DO - https://doi.org/10.1002/mabi.201600074 SN - 1616-5187 SN - 1616-5195 VL - 16 IS - 9 SP - 1287 EP - 1300 AN - OPUS4-37369 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Traulsen, C. H.-H. A1 - Kunz, V. A1 - Heinrich, Thomas A1 - Richter, S. A1 - Holzweber, Markus A1 - Schulz, A. A1 - von Krbek, L. K. S. A1 - Scheuschner, U. T. J. A1 - Poppenberg, J. A1 - Unger, Wolfgang A1 - Schalley, C. A. T1 - Synthesis and coordinative layer-by-layer deposition of pyridine-functionalized gold nanoparticles and tetralactam macrocycles on silicon substrates N2 - Coordination chemistry was applied to deposit pyridine-functionalized gold nanoparticles on silicon substrates. The particles were synthesized through the Brust/Schiffrin route with a subsequent ligand exchange reaction yielding well-defined particles of two different sizes. Multilayer deposition was carried out on a pyridine-terminated SAM, anchored on a hydroxyl-terminated silicon surface. Analogously, Hunter/Vögtle-type tetralactam macrocycle multilayers were deposited as well as mixed layers containing both either in an alternating sequence or as a macrocycle multilayer with a terminating nanoparticle layer. These composite layers were examined with respect to their ability to bind squaraine axles in the macrocycle cavities. The amount of guest bound is higher for the composite layer with alternating macrocycles and nanoparticles. KW - Layer-by-layer deposition KW - Functionalized Au nanoparticles KW - SEM KW - TEM KW - DLS KW - XPS KW - NEXAFS KW - ToF-SIMS KW - IR KW - UV-vis PY - 2013 DO - https://doi.org/10.1021/la403222x SN - 0743-7463 SN - 1520-5827 VL - 29 IS - 46 SP - 14284 EP - 14292 PB - American Chemical Society CY - Washington, DC AN - OPUS4-29699 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Reinecke, E.-A. A1 - Hübert, Thomas A1 - Tkatschenko, I. A1 - Kessler, A. A1 - Kuznetsov, M. A1 - Wilkins, M. A1 - Hedley, D. A1 - Azkarate, I. A1 - Proust, C. A1 - Acosta-Iborra, B. A1 - Gavrikov, B. A1 - De Bruijn, P.C.J. A1 - Marangon, A. A1 - Teodorczyk, A. A1 - Grafwallner, A. T1 - Integration of experimental facilities: a joint effort for establishing a common knowledge base in experimental work on hydrogen safety N2 - In the area of hydrogen safety, research facilities are essential for the experimental investigation of relevant phenomena, for testing devices and safety concepts, as well as for the generation of validation data for the various numerical codes and models. Within the framework of the European HySafe Network of Excellence (NoE), the 'Integration of Experimental Facilities (IEF)' activity has provided basic support for joint experimental work. Even beyond the funding period of the HySafe NoE in the 6th Framework Program, IEF represents a long-lasting effort for the sustainable integration of experimental research capacities and expertise of the partners from different research fields. In order to achieve a high standard in the quality of experimental data provided by the partners, emphasis was put on the know-how transfer between the partners. On the one hand, documentation on the experimental capacities was prepared and analyzed. On the other hand, a wiki-based communication platform was established, supported by biannual workshops covering topics ranging from measurement technologies to safety issues. Based on the partners' contributions, a working document was created on best practice including the joint experimental knowledge of all partners with regard to experimental set-ups and instrumentation. The paper gives an overview of the IEF partners and the network activities over the last five years. KW - Hydrogen safety KW - Experiments PY - 2011 DO - https://doi.org/10.1016/j.ijhydene.2010.04.162 SN - 0360-3199 VL - 36 IS - 3 SP - 2700 EP - 2710 PB - Elsevier CY - Oxford AN - OPUS4-23257 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Reinecke, E.-A. A1 - Hübert, Thomas A1 - Tkatschenko, I. A1 - Kessler, A. A1 - Kuznetsov, M. A1 - Wilkins, B. A. A1 - Hedley, D. A1 - Azkarate, I. A1 - Proust, C. A1 - Acosta-Iborra, B. A1 - Gavrikov, A. A1 - De Bruijn, P.C.J. A1 - Marangon, A. A1 - Teodorczyk, A. A1 - Grafwallner, F. T1 - Integration of experimental facilities: a joint effort for establishing a common knowledge base in experimental work on hydrogen safety T2 - 3rd International conference on hydrogen safety CY - Ajaccio, Corsica, France DA - 2009-09-16 PY - 2009 IS - ID 204 SP - 1 EP - 16 AN - OPUS4-20254 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bhuyan, Md Delwar Hossain A1 - Döhler, M. A1 - Lecieux, Y. A1 - Lupi, C. A1 - Thomas, J.-C. A1 - Schoefs, F. A1 - Hille, Falk A1 - Mevel, L. T1 - Statistical subspace based damage localization on Saint-Nazaire bridge mock-up N2 - The subject of damage localization is an important issue for Structural Health Monitoring (SHM) particularly in mechanical or civil structures under ambient excitation. In this paper, the statistical subspacebased damage localization method has been applied on a benchmark application, namely a 1/200 scale model of the Saint-Nazaire Bridge, which is a cable-stayed bridge located on the Loire River near the river’s mouth. The employed damage localization method combines data-driven features with physical parameter information from a finite element model in statistical tests, avoiding typical ill-conditioning problems of FE model updating. Damage is introduced in the mockup for cable failures on some of the 72 cables. The purpose of the experiment is to assess the capability of damage assessment methods to find a cable failure. T2 - 8. International Operational Modal Analysis Conference CY - Kopenhagen, Denmark DA - 12. Mai 2019 KW - Damage localization KW - Cable-stayed bridge KW - Cable failure KW - Structural health monitoring PY - 2019 SP - 1 EP - 9 AN - OPUS4-48183 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Bantz, C. A1 - Koshkina, Olga A1 - Lang, Thomas A1 - Galla, H.-J. A1 - Kirkpatrick, C.J. A1 - Stauber, R.H. A1 - Maskos, M. T1 - The surface properties of nanoparticles determine the agglomeration state and the size of the particles under physiological conditions N2 - Due to the recent widespread application of nanomaterials to biological systems, a careful consideration of their physiological impact is required. This demands an understanding of the complex processes at the bio–nano interface. Therefore, a comprehensive and accurate characterization of the material under physiological conditions is crucial to correlate the observed biological impact with defined colloidal properties. As promising candidates for biomedical applications, two SiO2-based nanomaterial systems were chosen for extensive size characterization to investigate the agglomeration behavior under physiological conditions. To combine the benefits of different characterization techniques and to compensate for their respective drawbacks, transmission electron microscopy, dynamic light scattering and asymmetric flow field-flow fractionation were applied. The investigated particle systems were (i) negatively charged silica particles and (ii) poly(organosiloxane) particles offering variable surface modification opportunities (positively charged, polymer coated). It is shown that the surface properties primarily determine the agglomeration state of the particles and therefore their effective size, especially under physiological conditions. Thus, the biological identity of a nanomaterial is clearly influenced by differentiating surface properties. KW - Nanomaterial characterization KW - Physiological conditions KW - Surface properties KW - Silica nanoparticles KW - Siloxane nanoparticles KW - Nanoparticles KW - Colloids KW - Silica KW - Polyorganosiloxane KW - Siloxane KW - Characterization KW - Transmission electron microscopy KW - TEM KW - Cryo-TEM KW - Asymetrical flow field-flow fractionation KW - AF-FFF KW - Field-flow fractionation KW - FFF KW - Dynamic light scattering KW - DLS KW - PCS PY - 2014 DO - https://doi.org/10.3762/bjnano.5.188 SN - 2190-4286 VL - 5 SP - 1774 EP - 1786 CY - Frankfurt, M. AN - OPUS4-32575 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Kannengießer, Thomas A1 - Mc Inerney, T. A1 - Florian, Wolfgang A1 - Böllinghaus, Thomas A1 - Cross, C.E. ED - Cerjak, H. T1 - The influence of local weld deformation on hot cracking susceptibility T2 - 6th International Seminar on the Numerical Analysis of Weldability CY - Seggauberg, Austria DA - 2001-10-01 PY - 2002 SN - 1-902653-56-4 N1 - Serientitel: Books of IOM3 – Series title: Books of IOM3 IS - 784 SP - 803 EP - 818 PB - Maney CY - London AN - OPUS4-1793 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Pettersson, C.O. A1 - Böllinghaus, Thomas A1 - Kannengießer, Thomas T1 - Corrosion testing of welds, a review of methods KW - Austenitic stainless steels KW - Carbon steels KW - Corrosion KW - Corrosion tests KW - Crevice corrosion KW - Duplex stainless steels KW - Fatigue strength KW - Galvanic corrosion KW - Intergranular corrosion KW - Low alloy steels KW - Mechanical properties KW - Nickel alloys KW - Pitting corrosion KW - Stress corrosion KW - Stainless steels KW - Steels KW - Unalloyed steels KW - Welded joints KW - Weld metal PY - 2007 SN - 0043-2288 SN - 1878-6669 VL - 51 IS - 7/8 SP - 79 EP - 106 PB - Springer CY - Oxford AN - OPUS4-15727 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Hinze, A. A1 - Klages, C.-P. A1 - Zänker, A. A1 - Thomas, M. A1 - Wirth, Thomas A1 - Unger, Wolfgang T1 - ToF-SIMS imaging of DBD-plasma-printed microspots on BOPP substrates N2 - Imaging ToF-SIMS has been applied to characterize the surface chemistry variations across small areas produced by a DBD-type plasma printing technique on a BOPP substrate using pure nitrogen and a nitrogen-hydrogen gas mixture. CH4N+ and CNO- secondary ions are detected with high yields remote from the discharge region. They are discussed to be due to surface modifications of the substrate by metastable gas-phase species. On the other hand, surface species exist that are preferentially formed by reactions of the substrate with short-lived species which are only present close to the plasma discharge region. A C3H8O+ secondary fragment ion is assumed to be a key fragment of such a surface species. KW - ToF-SIMS KW - Plasma KW - Polymer KW - Dielectric barrier discharges (DBD) KW - Plasma printing KW - Polymer modification KW - Surface modification KW - Time-of-flight secondary-ion mass spectroscopy (ToF-SIMS) imaging PY - 2008 DO - https://doi.org/10.1002/ppap.200700138 SN - 1612-8850 SN - 1612-8869 VL - 5 IS - 5 SP - 460 EP - 470 PB - Wiley-VCH Verl. CY - Weinheim AN - OPUS4-19342 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Funk, C. A1 - Dietrich, Paul A1 - Gross, Thomas A1 - Min, Hyegeun A1 - Unger, Wolfgang A1 - Weigel, W. T1 - Epoxy-functionalized surfaces for microarray applications: surface chemical analysis and fluorescence labeling of surface species N2 - Methods for characterization of epoxy-functionalized substrates used for microarray applications, prepared by silanization with 3-glycidoxypropyltrimethoxysilane, have been developed. Contact angle measurements, X-ray photoelectron spectroscopy, time of flight secondary ion mass spectrometry and fluorescence based methods have been applied to investigate these epoxy-functionalized microarray substrates. The surface density of epoxy-functionalized glass slides was investigated by fluorescence labeling of surface species utilizing Rhodamine 110 as fluorescence probe. KW - Epoxy silane KW - Microarrays KW - Fluorescence KW - XPS KW - ToF-SIMS KW - Surface analysis PY - 2012 DO - https://doi.org/10.1002/sia.3856 SN - 0142-2421 SN - 1096-9918 VL - 44 IS - 8 SP - 890 EP - 894 PB - Wiley CY - Chichester AN - OPUS4-26342 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Koshkina, Olga A1 - Bantz, C. A1 - Würth, Christian A1 - Lang, Thomas A1 - Resch-Genger, Ute A1 - Maskos, Michael T1 - Fluorophore-labeled siloxane-based nanoparticles for biomedical applications N2 - We present the synthesis and characterization of multifunctional fluorophore-labeled poly(organosiloxane) nanoparticles with core-shell architecture, where the fluorescent dye is incorporated into the core. Grafting of heterobifunctional poly(ethylene oxide) (PEO) onto the particle surface leads to water-soluble biocompatible nanoparticles. Two different strategies have been used for the synthesis: The encapsulation of dye-labeled monomers during the polycondensation with additional PEO coating and subsequent dye labeling by covalent attachment of the fluorescent dye rhodamine B to the (chloromethylphenyl)siloxane groups in the core after polymerization and grafting of PEO onto the surface. Comparison of the fluorescence quantum yields of the nanoparticles before and after PEO coating show a decrease in quantum yield after PEO coating. KW - Biocompatibility KW - Core-shell KW - Fluorescence KW - Fluorescence quantum yield KW - Nanoparticles KW - PEO PY - 2011 DO - https://doi.org/10.1002/masy.201100041 SN - 1022-1360 SN - 0258-0322 SN - 1521-3900 VL - 309/310 IS - 1 SP - 141 EP - 146 PB - Wiley-VCH Verl. CY - Weinheim AN - OPUS4-25143 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Debatin, F. A1 - Behrens, K. A1 - Weber, J. A1 - Baburin, I. A. A1 - Thomas, A. A1 - Schmidt, J. A1 - Senkovska, I. A1 - Kaskel, S. A1 - Kelling, A. A1 - Hedin, N. A1 - Bacsik, Z. A1 - Leoni, S. A1 - Seifert, G. A1 - Jäger, Christian A1 - Günter, C. A1 - Schilde, U. A1 - Friedrich, A. A1 - Holdt, H.-J. T1 - An isoreticular family of microporous metal-organic frameworks based on zinc and 2-substituted imidazolate-4-amide-5-imidate: syntheses, structures and properties N2 - We report on a new series of isoreticular frameworks based on zinc and 2-substituted imidazolate-4-amide-5-imidate (IFP-1–4, IFP=imidazolate framework Potsdam) that form one-dimensional, microporous hexagonal channels. Varying R in the 2-substitued linker (R=Me (IFP-1), Cl (IFP-2), Br (IFP-3), Et (IFP-4)) allowed the channel diameter (4.0–1.7 Å), the polarisability and functionality of the channel walls to be tuned. Frameworks IFP-2, IFP-3 and IFP-4 are isostructural to previously reported IFP-1. The structures of IFP-2 and IFP-3 were solved by X-ray crystallographic analyses. The structure of IFP-4 was determined by a combination of PXRD and structure modelling and was confirmed by IR spectroscopy and 1H MAS and 13C CP-MAS NMR spectroscopy. All IFPs showed high thermal stability (345–400°C); IFP-1 and IFP-4 were stable in boiling water for 7 d. A detailed porosity analysis was performed on the basis of adsorption measurements by using various gases. The potential of the materials to undergo specific interactions with CO2 was investigated by measuring the isosteric heats of adsorption. The capacity to adsorb CH4 (at 298 K), CO2 (at 298 K) and H2 (at 77 K) at high pressure were also investigated. In situ IR spectroscopy showed that CO2 is physisorbed on IFP-1–4 under dry conditions and that both CO2 and H2O are physisorbed on IFP-1 under moist conditions. KW - Adsorption KW - Metal-organic frameworks KW - Microporous materials KW - N,O ligands KW - Zinc PY - 2012 DO - https://doi.org/10.1002/chem.201200889 SN - 0947-6539 SN - 1521-3765 VL - 18 IS - 37 SP - 11630 EP - 11640 PB - Wiley-VCH Verl. CY - Weinheim AN - OPUS4-27725 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - RPRT A1 - Kromm, Arne A1 - Kannengießer, Thomas A1 - Gibmeier, J. A1 - Genzel, C. A1 - Mee, V. van der T1 - Determination of Residual Stresses in Low Transformation Temperature (LTT-) Weld Metals using X-ray and High Energy Synchrotron Radiation KW - Filler material KW - Low transformation temperature KW - Synchrotron radiation KW - Phase specific residual stresses KW - Energy dispersive diffraction PY - 2007 IS - II-1658r1-07 SP - 1 EP - 17 PB - International Institute of Welding CY - Paris AN - OPUS4-15716 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Lisy, M.-R. A1 - Goermar, A. A1 - Thomas, C. A1 - Pauli, Jutta A1 - Resch-Genger, Ute A1 - Kaiser, W.A. A1 - Hilger, I. T1 - In Vivo Near-infrared Fluorescence Imaging of Carcinoembryonic Antigen-expressing Tumor Cells in Mice N2 - Purpose: To prospectively depict carcinoembryonic antigen (CEA)-expressing tumors in mice with a high-affinity probe consisting of a near-infrared (NIR) fluorochrome and the clinically used anti-CEA antibody fragment arcitumomab. Materials and Methods: This study was approved by the regional animal committee. By coupling a NIR fluorescent (NIRF) cyanine dye (DY-676) to a specific antibody fragment directed against CEA (arcitumomab) and a nonspecific IgG Fab fragment, a bio-optical high-affinity fluorescent probe (anti-CEA–DY-676) and a low-affinity fluorescent probe (FabIgG–DY-676) were designed. The dye-to-protein ratios were determined, and both probes were tested for NIRF imaging in vitro on CEA-expressing LS-174T human colonic adenocarcinoma cells and CEA-nonexpressing A-375 human melanoma cells by using a bio-optical NIR small-animal imager. In vivo data of xenografted LS-174T and A-375 tumors in mice (n = 10) were recorded and statistically analyzed (Student t test). Results: The dye-to-protein ratios were determined as 3.0–3.5 for both probes. In vitro experiments revealed the specific binding of the anti-CEA–DY-676 probe on CEA-expressing cells as compared with CEA-nonexpressing cells; the FabIgG–DY-676 probe showed a markedly lower binding affinity to cells. In vivo LS-174T tumors xenografted in all mice could be significantly distinguished from A-375 tumors with application of the anti-CEA–DY-676 but not with that of the FabIgG–DY-676 at different times (2–24 hours, P < .005) after intravenous injection of the probes. Semiquantitative analysis revealed maximal fluorescence signals of anti-CEA–DY-676 to CEA-expressing tumors about 8 hours after injection. Conclusion: Findings of this study indicate the potential use of the high-affinity probe anti-CEA–DY-676 for specific NIRF imaging in in vivo tumor diagnosis. KW - Fluorescence spectroscopy KW - NIR fluorescent dye KW - NIRF imaging KW - Antibogy fragment arcitumomab KW - Carcinoembryonic antigen PY - 2008 DO - https://doi.org/10.1148/radiol.2472070123 SN - 0033-8419 SN - 1527-1315 VL - 247 IS - 3 SP - 779 EP - 787 PB - Radiological Society of North America CY - Oak Brook, Ill. AN - OPUS4-17629 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kromm, Arne A1 - Kannengießer, Thomas A1 - Gibmeier, J. A1 - Genzel, C. A1 - Van der Mee, V. T1 - Determination of residual stresses in low transformation temperature (LTT -) welds metals using X-rayand high energy synchrotron radiation N2 - Crack and fatigue resistance are relevant evaluation criteria for welded joints and are decreased by tensile residual stresses resulting from the welding and cooling process, while compressive residual stresses can have a positive influence on the characteristics mentioned. In order to generate compressive residual stresses, a set of post weld treatment procedures is available, like shot peening, hammering, etc. These procedures have the disadvantage that they are time and cost extensive and have to be applied after welding. As another point, such technologies can only produce compressive stresses at the top surface, i.e. can only contribute to the reduction of the risk of cracks initiated at the surface, like fatigue cracks. A chance to generate compressive stresses over the complete weld joint during the welding procedure is offered by the so-called Low Transformation Temperature (LTT -) filler wires. Compared to conventional wires, these materials show lower phase transformation temperatures, which can work against coolingrelated tensile stresses, resulting from respective shrinkage restraint. In consequence, distinct compressive residual stresses can be observed within the weld and adjacent areas. The strength of these fillers makes them potentially applicable to high-strength steel welding. Welds produced with different LTT – filler wires have shown different levels and distributions of the resulting residual stresses depending on the specific transformation temperature. The transformation temperatures are determined by temperature measurement. Classical X-ray diffraction as well as diffraction methods using high energy synchrotron radiation have been used for residual stress analysis. By means of high energy synchrotron diffraction in reflection mode residual stress depth gradients can be determined nondestructively. The phase selective nature of the diffraction measurements enables the simultaneous determination of the phase specific residual stresses of all contributing crystalline phases within one experiment. The application of white beam diffraction implies recording of a multitude of diffraction lines within the energy range of the provided energy spectrum of the white beam. By this means phase specific residual stress depth distributions up to distances of 150 ìm below the surface can be analysed for steel using the energy dispersive set-up of the HMI-beamline EDDI at the Bessy site, Berlin, providing an energy range between 20-150 keV. As a side effect quantitative phase analysis can be carried out using white energy dispersive diffraction e.g. the determination of the content of retained austenite in the weld. KW - Filler materials KW - Low temperature KW - Reference lists KW - Residual stresses KW - Temperature KW - Transformation KW - Synchrotron radiation KW - Phase specific residual stresses KW - Energy dispersive diffraction PY - 2009 SN - 0043-2288 SN - 1878-6669 VL - 53 IS - 1/2 SP - 3 EP - 16 PB - Springer CY - Oxford AN - OPUS4-19214 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Behnke, Thomas A1 - Mathejczyk, J.E. A1 - Brehm, Robert A1 - Würth, Christian A1 - Gomes, F.R. A1 - Dullin, C. A1 - Napp, J. A1 - Alves, F. A1 - Resch-Genger, Ute T1 - Target-specific nanoparticles containing a broad band emissive NIR dye for the sensitive detection and characterization of tumor development N2 - Current optical probes including engineered nanoparticles (NPs) are constructed from near infrared (NIR)-emissive organic dyes with narrow absorption and emission bands and small Stokes shifts prone to aggregation-induced self-quenching. Here, we present the new asymmetric cyanine Itrybe with broad, almost environment-insensitive absorption and emission bands in the diagnostic window, offering a unique flexibility of the choice of excitation and detection wavelengths compared to common NIR dyes. This strongly emissive dye was spectroscopically studied in different solvents and encapsulated into differently sized (15, 25, 100 nm) amino-modified polystyrene NPs (PSNPs) via a one-step staining procedure. As proof-of-concept for its potential for pre-/clinical imaging applications, Itrybe-loaded NPs were surface-functionalized with polyethylene glycol (PEG) and the tumor-targeting antibody Herceptin and their binding specificity to the tumor-specific biomarker HER2 was systematically assessed. Itrybe-loaded NPs display strong fluorescence signals in vitro and in vivo and Herceptin-conjugated NPs bind specifically to HER2 as demonstrated in immunoassays as well as on tumor cells and sections from mouse tumor xenografts in vitro. This demonstrates that our design strategy exploiting broad band-absorbing and -emitting dyes yields versatile and bright NIR probes with a high potential for e.g. the sensitive detection and characterization of tumor development and progression. KW - Nanoparticle KW - Fluorescence KW - In vitro test KW - In vivo test KW - Surface modification KW - Cytotoxicity PY - 2013 DO - https://doi.org/10.1016/j.biomaterials.2012.09.028 SN - 0142-9612 VL - 34 IS - 1 SP - 160 EP - 170 PB - Elsevier CY - Oxford AN - OPUS4-26877 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Witte, Julien A1 - Schröpfer, Dirk A1 - Hamacher, M. A1 - Michels, H. A1 - Hamm, C. A1 - Appelt, M. A1 - Börner, Andreas A1 - Kannengießer, Thomas T1 - Tool development for hybrid finishing milling of iron aluminides N2 - The importance of high-temperature materials made of iron aluminides (FeAl) has been increasing in light weight applications, e.g., airplane turbines, due to the high material’s specific strength. However, the highly economic production by means of permanent mold casting involves special microstructures for Fe26Al4Mo0.5Ti1B alloy components leading to difficult machinability for subsequent finishing milling and low surface qualities. Major effects of tool and machining parameter variation incorporating ultrasonic assistance on the milling process and surface integrity are shown. Loads for tool and component surface are significantly adjustable to enable an economic process chain regarding the surface integrity of safety-relevant components. KW - Ultrasonic-assisted milling KW - Iron aluminide KW - Surface integrity KW - Tool wear PY - 2022 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-566294 DO - https://doi.org/10.1016/j.procir.2022.03.123 SN - 2212-8271 VL - 108 SP - 793 EP - 798 PB - Elsevier B.V. AN - OPUS4-56629 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Gollnow, C. A1 - Griesche, Axel A1 - Weidemann, Jens A1 - Kannengießer, Thomas T1 - Influence of external loads on a characteristic angle between grains and solidus line as an indicator for hot cracking susceptibility during GTA welding N2 - A long list of criteria determining the hot cracking susceptibility already exists. A main influence on solidification cracking can result from the design of the welded construction, i.e. from the influence of external loads. Using the Controlled Tensile Weldability (CTW) test, an external load hot cracking test, the influence of constant pre-load and different extension rates on the solidification cracking behavior of GTA (Gas Tungsten Arc) welds in an austenitic (AISI 309) and a ferritic (AISI 441) steel were investigated. Compared to specimens welded allowing free shrinkage and welded with an applied constant tensile pre-load, the specimens welded during the application of increasing tensile load show solidification cracks. In the weld seams, a characteristic angle α between the predominantly columnar grains and the fusion line can be observed. Specimens showing solidification cracks show a significantly larger angle α compared to the crack-free specimens. Based on these observations, the characteristic angle α is proposed as a new hot cracking criterion. KW - Hot cracking KW - External load test KW - Component design KW - Crack criterion KW - Grain growth PY - 2017 DO - https://doi.org/10.1016/j.jmatprotec.2016.08.013 VL - 239 SP - 172 EP - 177 PB - Elsevier AN - OPUS4-37278 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kannengießer, Thomas A1 - Kromm, Arne A1 - Rethmeier, Michael A1 - Gibmeier, J. A1 - Genzel, C. T1 - Residual stresses and in-situ measurement of phase transformation in low transformation temperature (LTT) welding materials PY - 2009 SN - 1097-0002 SN - 0069-8490 SN - 0376-0308 VL - 52 SP - 755 EP - 762 CY - Newtown Square, Pa., USA AN - OPUS4-19817 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Unger, Wolfgang A1 - Schwarz, F. A1 - Heinrich, Thomas A1 - Kaufmann, J. O. A1 - Lippitz, Andreas A1 - Puttreddy, R. A1 - Rissanen, K. A1 - Schalley, C. A. T1 - Photocontrolled on-surface pseudorotaxane formation with well-ordered macrocycle multilayers N2 - The photoinduced pseudorotaxane formation between a photoresponsive axle and a tetralactam macrocycle was investigated in solution and on glass surfaces with immobilized multilayers of macrocycles. In the course of this reaction, a novel photoswitchable binding station with azobenzene as the photoswitchable unit and diketopiperazine as the binding station was synthesized and studied by NMR and UV/Vis spectroscopy. Glass surfaces have been functionalized with pyridine-terminated SAMs and subsequently withmultilayers of macrocycles through layer-by-layer self assembly. A preferred orientation of the macrocycles could be confirmed by NEXAFS spectroscopy. The photocontrolled Deposition of the axle into the surface-bound macrocycle-multilayers was monitored by UV/Vis spectroscopy and led to an increase of the molecular order, as indicated by more substantial linear dichroism effects in angle-resolved NEXAFS spectra. KW - Well-ordered macrocycle multilayers KW - XPS KW - NEXAFS PY - 2016 DO - https://doi.org/10.1002/chem.201603156 SN - 0947-6539 SN - 1521-3765 VL - 22 IS - 40 SP - 14383 EP - 14389 PB - Wiley-VCH Verlag GmbH & Co. KGaA CY - Weinheim AN - OPUS4-38270 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Schmid, Thomas A1 - Jungnickel, R. A1 - Neuhaus, B. A1 - Riedel, Jens A1 - Kneipp, Janina A1 - Lüter, C. T1 - Raman spectroscopy as a tool for the collection management of microscope slides N2 - Throughout the history of preparation of biological samples for microscopy the choice of the mounting medium was sometimes dictated merely by availability of the used media. Thus, a plethora of resins and other organic polymers as well as complex mixtures are found to serve as mounting agents in microscope slide collections of museums of natural history, impeding the work for both curators and conservators. Dramatically, in some cases the used mounting media can already be observed to have undergone crystallization and other decomposition processes within few years of mounting demanding immediate action in restoring as well as an imminent precaution in conservation. Therefore, an unambiguous chemical identification of the used agent as well as its current aging stage is of great interest for the biologist community. The technical demands on the analytical approach to obtain this information can be straightforwardly identified. Any used technique has to be non-destructive, yield in molecular information allowing for a chemical identification of the used mounting agents and allow for a spatially well-defined interrogation in a thin sample slice, typically through a transparent cover slip. In this contribution we present a thorough study of the applicability of Raman spectroscopy for the described task. The obtained results clearly demonstrate the successful feasibility of the chosen method for a) a clear distinction between different media, b) the elucidation of the chemical composition of a multicomponent medium and c) an unambiguous identification of real unknown samples by a distinct assignment to a previously recorded spectral library. This library database was built up by recording pure mounting agents and will be provided to the general public. In combination with a Raman spectrometer, it can be an invaluable tool for future curation and conservation endeavors devoted to microscope slide collections at natural history museums. KW - Taxonomy KW - Mounting medium KW - Coverslip seal PY - 2016 DO - https://doi.org/10.1016/j.jcz.2016.07.002 SN - 0044-5231 VL - 265 SP - 178 EP - 190 PB - Elsevier AN - OPUS4-38210 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Pelkner, Matthias A1 - Pohl, Rainer A1 - Erthner, Thomas A1 - Kreutzbruck, Marc A1 - Commandeur, C. T1 - Detection of hidden defects in thin steel plates using GMR sensor arrays N2 - At BAM, the Federal Institute for Materials Research and Testing, a group of scientists develops NDT-applications based on GMR sensor technology. In particular, the knowledge gained in the field of automated testing systems based on the magnetic flux leakage (MFL) were combined with GMR sensors to achieve high resolution testing of ferromagnetic materials. In cooperation with Europe's second largest steel producer, Tata Steel Europe, BAM is working on solutions for the detection of small inhomogeneities in thin steel plates. The objective is to incorporate an automated testing facility in a production line. Before setting up an automated testing system, a feasibility study was carried out in order to verify the ability of GMR-MFL-testing and eddy current testing (ET) for the detection of hidden defects in thin steel plates. For this purpose, Tata Steel Europe fabricated in a first step test samples of 0.2 mm thick steel plates in which defects of different depth (5 – 60 µm) were introduced. Only in case of GMR-MFL-testing, we were able to detect parts of the hidden defects trustworthily with a SNR better than 10 dB. The lift off between sensor and surface was 250 ìm. On this basis, we investigated different testing scenarios including velocity tests and different lift offs. The achieved results for this special testing problem were presented leading to a practical example for GMR-based testing and paving the way to an automated testing system in a production line. T2 - ECNDT 2014 - 11th European conference on non-destructive testing CY - Prague, Czech Republic DA - 2014-10-06 KW - Magnetic flux leakage KW - GMR KW - Hidden defects PY - 2014 UR - http://www.ndt.net/events/ECNDT2014/app/content/Paper/286_Pelkner.pdf SN - 978-80-214-5018-9 SP - 1 EP - 7(?) AN - OPUS4-32234 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Pelkner, Matthias A1 - Commandeur, C. A1 - Erthner, Thomas A1 - Kreutzbruck, Marc A1 - Pohl, Rainer T1 - Detektion verdeckter Defekte in dünnen Stahlblechen mit GMR-Sensoren N2 - Seit einigen Jahren beschäftigt sich eine Gruppe der BAM mit der Entwicklung angepasster GMR-Sensorik (giant magneto resistance, Riesenmagnetwiderstand) für spezielle ZfP-Probleme. Hierbei wurden reichhaltige Erfahrungen auf dem Gebiet der automatisierten Streuflussprüfung mit GMR-Sensoren gesammelt (DACH-Tagung 2012, Graz). Die an der BAM gewonnenen Erkenntnisse veranlassten Europas zweitgrößten Stahlhersteller, Tata Steel Europe, mit der BAM eine Lösung für ein spezielles Prüfproblem zu finden. Ziel ist es, dünne Bleche im Fertigungsprozess auf kleinste Inhomogenitäten automatisiert zu prüfen. In einem ersten Schritt wurden durch die Tata Steel Europe 0,2 Millimeter starke Testbleche hergestellt, in die Fehler von 5-60 Mikrometern Tiefe eingebracht wurden. Anschließend wurden von der BAM vergleichende Prüfungen mit Wirbelstrom und GMR-Streufluss durchgeführt. Nur mit letzterer Methode gelang es, einen Teil der verdeckten Testfehler sicher zu detektieren. In einem zweiten Schritt wurden verschiedene Untersuchungen zur Praxistauglichkeit der Sensorik (Prüfgeschwindigkeit; Sensorabstand etc.) durchgeführt. Die Ergebnisse der verschiedenen Untersuchungen und ein möglicher Weg zum praktischen Einsatz der Sensorik werden vorgestellt. T2 - DGZfP-Jahrestagung 2014 CY - Potsdam, Germany DA - 2014-05-26 KW - GMR KW - Streufluss KW - Zerstörungsfreie Prüfung PY - 2014 UR - http://jt2014.dgzfp.de/portals/jt2014/BB/mo3b2.pdf SN - 978-3-940283-61-0 IS - DGZfP-BB 148 SP - Mo.3.B.2, 1 EP - 10 AN - OPUS4-32229 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Pohl, Rainer A1 - Commandeur, C. A1 - Erthner, Thomas A1 - Kreutzbruck, M. A1 - Pelkner, Matthias T1 - GMR-Streufluss-Prüfsystem zur Detektion verdeckter Fehler in Feinblechen N2 - BAM und TATA Steel untersuchen gemeinsam, ob sich die Prüfung von ferritischen Feinblechen mit einer Stärke von etwa 0,2 mm während der Fertigung durch den Einsatz von GMR-Sensorik verbessern lässt. Hierzu wurde eine Vorstudie an Feinblechen mit eingebrachten Mikronuten durchgeführt. Diese Nuten variieren in ihrer Tiefe zwischen 5 μm und 60 μm und wurden verdeckt mit ZfP-angepassten GMR-Sensorarrays geprüft. Die Ergebnisse der Vorstudie zeigten, dass bei verdeckter Prüfung schon kleinste Defekte mit einer Tiefe von 10 μm - gleichbedeutend mit einer Restwanddicke von 90 % – mit einem SNR > 6 dB detektiert werden konnten, wobei der Abstand der Prüfsonde zur Oberfläche bis zu 500 μm betrug. Zudem wurden in der Vorstudie Untersuchungen zur Prüfgeschwindigkeit und Praxistauglichkeit durchgeführt. Basierend auf den hier gewonnenen Ergebnissen wird ein erster Demonstrator für eine zuverlässige Prüfung eines Teilbereiches von 50 mm des Feinbleches innerhalb einer Produktionslinie aufgebaut. Zum Einsatz kommen Prüfsonden mit jeweils 24 GMR-Sensorelementen. Hierbei wird das Ziel einer umfassenden Prüfung des Feinblechs über die gesamte Breite von 1200 mm angestrebt. Eine besondere Herausforderung stellt dabei die hohe Anzahl von mehr als 1000 Sensorelementen dar. Das hierfür entwickelte Prüfkonzept umfasst neben einer angepassten Erzeugung des Magnetfeldes die Entwicklung einer geeigneten schnellen und sicheren Elektronik für die neuen Mehrkanalprüfköpfe. Neben der Vorstellung des Prüfkonzeptes und seiner Eigenschaften vergleichen wir die erzielten Prüfergebnisse an verschiedenen Vergleichsfehlern mit denen der Vorstudie. T2 - DACH-Jahrestagung 2015 CY - Salzburg, Austria DA - 11.05.2015 KW - Streuflussprüfung KW - GMR PY - 2015 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-343354 SN - 978-3-940283-68-9 IS - DGZfP BB 152 SP - Mi.2.B.3, 1 EP - 9 AN - OPUS4-34335 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Koshkina, Olga A1 - Lang, Thomas A1 - Thiermann, R. A1 - Docter, D. A1 - Stauber, R.H. A1 - Secker, C. A1 - Schlaad, H. A1 - Weidner, Steffen A1 - Mohr, B. A1 - Maskos, M. A1 - Bertin, Annabelle T1 - Temperature-triggered protein adsorption on polymer-coated nanoparticles in serum N2 - The protein corona, which forms on the nanoparticle's surface in most biological media, determines the nanoparticle’s physicochemical characteristics. The formation of the protein corona has a significant impact on the biodistribution and clearance of nanoparticles in vivo. Therefore, the ability to influence the formation of the protein corona is essential to most biomedical applications, including drug delivery and imaging. In this study, we investigate the protein adsorption on nanoparticles with a hydrodynamic radius of 30 nm and a coating of thermoresponsive poly(2-isopropyl-2-oxazoline) in serum. Using multiangle dynamic light scattering (DLS) we demonstrate that heating of the nanoparticles above their phase separation temperature induces the formation of agglomerates, with a hydrodynamic radius of 1 µm. In serum, noticeably stronger agglomeration occurs at lower temperatures compared to serum-free conditions. Cryogenic transmission electron microscopy (cryo-TEM) revealed a high packing density of agglomerates when serum was not present. In contrast, in the presence of serum, agglomerated nanoparticles were loosely packed, indicating that proteins are intercalated between them. Moreover, an increase in protein content is observed upon heating, confirming that protein adsorption is induced by the alteration of the surface during phase separation. After cooling and switching the surface back, most of the agglomerates were dissolved and the main fraction returned to the original size of approximately 30 nm as shown by asymmetrical flow-field flow fractionation (AF-FFF) and DLS. Furthermore, the amounts of adsorbed proteins are similar before and after heating the nanoparticles to above their phase-separation temperature. Overall, our results demonstrate that the thermoresponsivity of the polymer coating enables turning the corona formation on nanoparticles on and off in situ. As the local heating of body areas can be easily done in vivo, the thermoresponsive coating could potentially be used to induce the agglomeration of nanoparticles and proteins and the accumulation of nanoparticles in a targeted body region. PY - 2015 DO - https://doi.org/10.1021/acs.langmuir.5b00537 SN - 0743-7463 SN - 1520-5827 VL - 31 IS - 32 SP - 8873 EP - 8881 PB - American Chemical Society CY - Washington, DC AN - OPUS4-34163 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Schwarz, F. A1 - Heinrich, Thomas A1 - Lippitz, Andreas A1 - Unger, Wolfgang A1 - Schalley, C. T1 - A photoswitchable rotaxane operating in monolayers on solid support N2 - A novel photoswitchable rotaxane was synthesised and its switching behaviour in solution was analysed with NMR and UV-Vis. A monolayer of rotaxanes was deposited on glass surfaces and the on-surface photoswitching was investigated. Angle-resolved NEXAFS spectra revealed a preferential orientation that reversibly changes upon switching. KW - XPS KW - NEXAFS KW - Photoswitchable rotaxane KW - Self assembly PY - 2016 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-386814 DO - https://doi.org/10.1039/c6cc08586e SN - 0022-4936 SN - 1364-548X SN - 0009-241x SN - 1359-7345 VL - 52 IS - 100 SP - 14458 EP - 14461 PB - Royal Society of Chemistry (RSC) AN - OPUS4-38681 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CHAP A1 - Kannengießer, Thomas A1 - Cross, C. E. A1 - Schobbert, H. ED - Düsseldorf, DVS T1 - Prüfung der Kalt- und Heißrisssicherheit gefügter Bauteile N2 - Kaltrisssicherheit, Kaltrissprüfverfahren nach DIN EN ISO 17642, TEKKEN-Test, CTS-Test, Implant-Test, Untersuchungen zur Kaltrisssicherheit hochfester Feinkornbaustähle, Heißrisssicherheit, MVT-Test, Einfluss des Einspannbedingungen auf die Heißrissbildung von Aluminiumlegierungen KW - Kaltrisssicherheit KW - Heißrisssicherheit KW - TEKKEN-Test KW - MVT-Test PY - 2006 SN - 0935-0292 VL - 2006 SP - 142 EP - 150 PB - DVS Verlag CY - Düsseldorf AN - OPUS4-39035 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Gollnow, C. A1 - Kannengießer, Thomas ED - Böllinghaus, Thomas ED - Lippold, J. E. ED - Cross, C. E. T1 - Consideration of welding-specific component design on solidification crack initiation N2 - A commonly used way of minimizing the occurrence of hot cracks, especially solidification cracks during component welding, is mainly to analyse and vary process parameters such as welding speed and consequently the heat input. Metallurgy and component design are however hardly ever considered due to special production requirements and therefore, restricted flexibility in material selection and design. Such conditions, especially crack-critical welding positions are given by slot-welds or welds near pre-deformed areas, for instance bending edges. Hence, it follows that increased local and global residual component stress caused cracking on reaching a solidification crack critical level, which is characterised by solidification crack initiation. T2 - 4th International Workshop Cracking Phenomena in Welds CY - BAM, Berlin, Germany DA - 02.04.2014 KW - solidification cracks PY - 2016 SN - 978-3-319-28432-3 DO - https://doi.org/10.1007/978-3-319-28434-7_6 SP - 101 EP - 117 PB - Springer International Publishing CY - Cham, Switzerland AN - OPUS4-36567 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Münster, C. A1 - Mente, Tobias A1 - Rhode, Michael A1 - Böllinghaus, Thomas ED - Sommitsch, C. ED - Enzinger, N. ED - Mayr, P. T1 - Modelling of hydrogen diffusion in power station steels and influence of experimental conditions on the determination of diffusion coefficients N2 - In the field of modelling hydrogen assisted cracking (HAC) phenomenon, hydrogen diffusivity is an important input parameter for numerical simulation. In terms of hydrogen diffusion coefficients, they have great impact on realistic assessment of the evolution of possible crack critical hydrogen concentrations. In addition, the chemical compositions of steels can have a strong effect on hydrogen diffusion. Unfortunately, literature provides a wide range of available hydrogen diffusion coefficients even for similar microstructures and equal temperatures. The scattering of the data can lead to significant deviations in the results of simulating the evolving hydrogen concentrations due to hydrogen uptake (by fabrication or service). Thus, the application of such data to crack-models or for component life tie predictions can be realized up to the present only by considering envelope curves of such value, corresponding to a work or bench case scenario, respectively. For improved reliability of numerical simulaitons, it is necessary to minimize the mentioned deviation of these data. Hence, this work focuses on the validation of hydrogen diffusion coefficients obtained from permeation experiments at room temperature. Two baintic steels with different alloying concepts were investigated, the creep-resistant 7CrMoVTiB10-10 and the reactor pressure vessel grade 20MnMoNi4-5. A numerical model is presented for simulation of the corresponding hydrogen diffusion during permeation experiments using the finite element software ANSYS. Three different diffusion coefficients (obtained from different common calculation methods) are considered and compared to numerical results. The vases of thes calculation methods are permeation transients which are a direct measure for hydrogen. The results of the simulated hydrogen diffusion coefficients show that only one procedure for calculation of diffusion coefficitnes is suitable in comparision to the experimental values. Thus, it is suggested to use this method for analysis of experimental results in case of hydrogen diffusion during permeation experiments. Furthermore, this work supplies validated values for the hydrogen diffusion coefficients of both steel grades. KW - Hydrogen KW - Diffusion Coefficient KW - Numerical Simulation KW - Permeation KW - Creep-resistant Steel KW - Pressure Vessel Steel PY - 2016 SN - 978-3-85125-490-7 SN - 2410-0544 SP - 435 EP - 457 PB - Technische Universität Graz CY - Graz AN - OPUS4-38917 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Streeck, C. A1 - Wirth, Thomas A1 - Unger, Wolfgang A1 - Beckhoff, B. T1 - Qualifying calibration samples for advanced thin film materials characterisation N2 - In this article the question of the certification of calibration samples for the characterisation of advanced thin film materials is addressed within the framework of reliable process control or quality management purposes. Reference measurement techniques can be used in order to address the gap in appropriate certified reference materials (CRMs) for thin film analyses. They allow for qualifying out-of-production samples originating from an operating production line as calibration samples. As a template for this procedure, CIGS [Cu(In,Ga)Se2] layers, that are absorber layers for high efficiency thin-film solar cells, have been used for establishing and validating reference-free X-ray fluorescence (XRF) analysis and Auger-electron spectroscopy (AES) as reference measurement techniques. The focus was on determining the average mole fractions in the CIGS layers obtaining results traceable to the SI unit system. Reference-free XRF is physically traceable and is based upon radiometrically calibrated instrumentation and knowledge of atomic fundamental data. Sputter-assisted AES can be established as a chemically traceable method after careful calibration using a certified reference material (CRM) based on a total number counting method. KW - CIGS KW - X-ray fluorescence (XRF) KW - Auger-electron spectroscopy (AES) PY - 2018 UR - https://www.spectroscopyeurope.com/article/qualifying-calibration-samples-advanced-thin-film-materials-characterisation VL - 30 IS - 1 SP - 11 EP - 14 PB - John Wiley & Sons Ltd CY - Chichester, West Sussex PO19 8SQ, UK AN - OPUS4-44260 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bhuyan, Md Delwar Hossain A1 - Döhler, M. A1 - Lecieux, Y. A1 - Lupi, C. A1 - Thomas, J. A1 - Schoefs, F. A1 - Hille, Falk A1 - Mevel, L. T1 - Statistical Subspace-based Damage Localization on Saint-Nazaire Bridge Mock-Up N2 - The subject of damage localization is an important issue for Structural Health Monitoring (SHM) particularly in mechanical or civil structures under ambient excitation. In this paper, the statistical subspacebased damage localization method has been applied on a benchmark application, namely a 1/200 scale model of the Saint-Nazaire Bridge, which is a cable-stayed bridge located on the Loire River near the river’s mouth. The employed damage localization method combines data-driven features with physical parameter information from a finite element model in statistical tests, avoiding typical ill-conditioning problems of FE model updating. Damage is introduced in the mockup for cable failures on some of the 72 cables. The purpose of the experiment is to assess the capability of damage assessment methods to find a cable failure. T2 - International Operational Modal Analysis Conference CY - Copenhagen, Danmark DA - 13.05.2019 KW - Structural health monitoring KW - Damage localization KW - Cable-stayed bridge KW - Cable failure PY - 2019 SP - 1 EP - 9 AN - OPUS4-48243 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Faghani, A. A1 - Gholami, M. F. A1 - Trunk, M. A1 - Müller, J. A1 - Pachfule, P. A1 - Vogl, S. A1 - Donskyi, Ievgen A1 - Li, M. A1 - Nickl, Philip A1 - Shao, J. A1 - Huang, M. R. S. A1 - Unger, Wolfgang A1 - Arenal, R. A1 - Koch, C. T. A1 - Paulus, B. A1 - Rabe, J. P. A1 - Thomas, A. A1 - Haag, R. A1 - Adeli, M. T1 - Metal-Assisted and Solvent-Mediated Synthesis of Two-Dimensional Triazine Structures on Gram Scale N2 - Covalent triazine frameworks are an emerging material class that have shown promising performance for a range of applications. In this work, we report on a metal-assisted and solvent-mediated reaction between calcium carbide and cyanuric chloride, as cheap and commercially available precursors, to synthesize two-dimensional triazine structures (2DTSs). The reaction between the solvent, dimethylformamide, and cyanuric chloride was promoted by calcium carbide and resulted in dimethylamino-s-triazine intermediates, which in turn undergo nucleophilic substitutions. This reaction was directed into two dimensions by calcium ions derived from calcium carbide and induced the formation of 2DTSs. The role of calcium ions to direct the two-dimensionality of the final structure was simulated using DFT and further proven by synthesizing molecular intermediates. The water content of the reaction medium was found to be a crucial factor that affected the structure of the products dramatically. While 2DTSs were obtained under anhydrous conditions, a mixture of graphitic material/2DTSs or only graphitic material (GM) was obtained in aqueous solutions. Due to the straightforward and gram-scale synthesis of 2DTSs, as well as their photothermal and photodynamic properties, they are promising materials for a wide range of future applications, including bacteria and virus incapacitation. KW - XPS KW - Triazine KW - 2D PY - 2020 DO - https://doi.org/10.1021/jacs.0c02399 VL - 142 IS - 30 SP - 12976 EP - 12986 PB - ACS American Chemical Society AN - OPUS4-51203 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Markus, M. A. A1 - Napp, J. A1 - Behnke, Thomas A1 - Mitkovski, M. A1 - Monecke, S. A1 - Dullin, C. A1 - Kilfeather, S. A1 - Dressel, R. A1 - Resch-Genger, Ute A1 - Alves, F. T1 - Tracking of inhaled near-infrared fluorescent nanoparticles in lungs of SKH-1 mice with allergic airway inflammation N2 - Molecular imaging of inflammatory lung diseases, such as asthma, has been limited to date. The recruitment of innate immune cells to the airways is central to the inflammation process. This study exploits these cells for imaging purposes within the lung, using inhaled polystyrene nanoparticles loaded with the near-infrared fluorescence dye Itrybe (Itrybe-NPs). By means of in vivo and ex vivo fluorescence reflectance imaging of an ovalbumin-based allergic airway inflammation (AAI) model in hairless SKH-1 mice, we show that subsequent to intranasal application of Itrybe-NPs, AAI lungs display fluorescence intensities significantly higher than those in lungs of control mice for at least 24 h. Ex vivo immunofluorescence analysis of lung tissue demonstrates the uptake of Itrybe-NPs predominantly by CD68+CD11c+ECF-L+MHCIIlow cells, identifying them as alveolar M2 macrophages in the peribronchial and alveolar areas. The in vivo results were validated by confocal microscopy, overlapping tile analysis, and flow cytometry, showing an amount of Itrybe-NP-containing macrophages in lungs of AAI mice significantly larger than that in controls. A small percentage of NP-containing cells were identified as dendritic cells. Flow cytometry of tracheobronchial lymph nodes showed that Itrybe-NPs were negligible in lung draining lymph nodes 24 h after inhalation. This imaging approach may advance preclinical monitoring of AAI in vivo over time and aid the investigation of the role that macrophages play during lung inflammation. Furthermore, it allows for tracking of inhaled nanoparticles and can hence be utilized for studies of the fate of potential new nanotherapeutics. KW - Itrybe nanoparticles KW - In vivo near-infrared fluorescence imaging KW - Allergic airway inflammation KW - Cell tracking KW - Alveolar macrophages PY - 2015 DO - https://doi.org/10.1021/acsnano.5b04026 SN - 1936-0851 VL - 9 IS - 12 SP - 11642 EP - 11657 PB - ACS Publ. CY - Washington, DC, USA AN - OPUS4-35302 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Lippold, J. C. A1 - Böllinghaus, Thomas A1 - Richardson, I. T1 - Welding in the world - Update 2018 N2 - In 2018, the Journal "Welding in the World" published 6 issues that contained 120 papers and over 1300 pages of fundamental and applied research associated with materials joining and allied technologies. KW - Journal KW - Editorial Board KW - Year in Review PY - 2019 DO - https://doi.org/10.1007/s40194-018-00695-9 SN - 0043-2288 SN - 1878-6669 VL - 63 IS - 1 SP - 1 PB - Springer CY - Berlin AN - OPUS4-50064 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Heinrich, Thomas A1 - Darlatt, Erik A1 - Lippitz, Andreas A1 - Müller, S. A1 - Schalley, C. A1 - Unger, Wolfgang T1 - Systematic XP and NEXAFS spectroscopy studies of (ter-)pyridineterminated self-assembled monolayers and their addressability for functional molecules N2 - The chemical composition of surfaces functionalized with self-assembled monolayers (SAMs) is an important parameter that determines their performance in a broad range of applications, from immobilizing molecular machines to initiation and growth control of MOFs (Metal-Organic Frameworks). In this article, a critical Survey of XPS (X-ray photoelectron spectroscopy) and NEXAFS (near edge X-ray absorption fine structure) spectroscopy data for pyridine-functionalized monolayers on gold surfaces is presented to compile correlations that have been indiscernible before. Monolayers with aromatic backbones are compared to monolayers with aliphatic backbones. Monolayers with pyridine end-groups are compared to mixed monolayers formed terpyridine-functionalized by molecules end-groups and non-functionalized molecules. Thiol-oxidation during ageing of the SAMs in air is addressed. And finally, the addressability of the SAMs for the deposition of metal-ions and organic molecules is investigated and compared. This work consequently delivers a comprehensive set of spectroscopic data of (ter-)pyridine-terminated SAMs and their performance as template for the preparation of functional multilayers of macrocycles exhibiting a preferential orientation. KW - (ter-)pyridineterminated self-assembled monolayer KW - X-ray Photoelectron Spectroscopy (XPS) KW - NEXAFS PY - 2019 DO - https://doi.org/10.1016/j.elspec.2019.03.011 VL - 233 SP - 28 EP - 37 PB - Elsevier B.V. AN - OPUS4-48018 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Berthold, J. A1 - Vrana, J. A1 - Heckel, Thomas A1 - Kanzler, D. A1 - Jatzlau, P. A1 - Große, C. T1 - Modellgestützte Bestimmung der Auffindwahrscheinlichkeit (POD) von Reflektoren bei der Ultraschallprüfung großer Schmiedeteile N2 - Bruchmechanische Untersuchungen werden zur Vorhersage der Lebensdauer und der Wartungszyklen benutzt. Dabei wird davon ausgegangen, dass auch Objekte ohne detektierte Anzeigen Materialfehler mit einer Reflektivität kleiner der Nachweisgrenze aufweisen können. Keine detektierte Anzeige bedeutet daher für Bauteilauslegung, dass sie eine konservative Annahme machen müssen: es wird angenommen, dass das Bauteil Materialfehler in Größe der Nachweisgrenze enthält. Dies macht die Nachweisgrenze zu dem die Lebensdauer limitierenden Faktor. Bei probabilistischen Methoden wird zusätzliches Wissen, wie Zuverlässigkeit und Fehlerauffindwahrscheinlichkeiten bei der zerstörungsfreien Prüfung mit in die Berechnung einbezogen, um zu konservative Annahmen zu vermeiden. Ziel ist es eine Model-Assisted-POD aufzubauen mit der die reale volumetrische Ultraschallprüfung großer Schmiedeteile nachgebildet werden kann. Die resultierende POD soll im Weiteren in bruchmechanischen Betrachtungen Verwendung finden. In vorangegangenen Arbeiten [Preißel2015] wurde dazu der Einfluss des Prüfrasters nach der DGZfP-Richtlinie US 07:2014 auf die Fehlerauffindwahrscheinlichkeit (parametrisch) simulativ betrachtet und die Simulationstechnik experimentell validiert. In diesem Paper werden die Ergebnisse von Preißel überprüft und um eine Prüfraster-Summen-POD, die das Szenario der realen Bauteilprüfung beschreibt, erweitert. Zudem wird eine experimentell validierte, simulative, nicht-parametrische POD für schrägliegende Defekte aufgebaut. Schließlich werden erste Untersuchungen zur Defektmorphologie vorgestellt. Diese Arbeit ist im Rahmen eines Studenten-Stipendiums der DGZfP entstanden. T2 - DGZfP DACH Tagung 2019 CY - Friedrichshafen, Germany DA - 27.05.2019 KW - Schmiedeteile KW - POD KW - Ultraschall KW - Zerstörungsfreie Prüfung PY - 2019 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-496796 UR - http://www.ndt.net/?id=24529 VL - 24 IS - 8 SP - 1 EP - 12 PB - NDT.net CY - Kirchwald AN - OPUS4-49679 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Trela, C. A1 - Kind, Thomas A1 - Günther, Martin T1 - Ground penetrating radar in reflection vs transmission mode for void detection in concrete structures N2 - The concreting of prefabricated concrete structures can lead to insufficient bonding or even to remaining cavities. Honeycombs (aggregate clusters without cement) represent potential weakening of the structure and need to be detected non-destructively. In our study we tested the capability of ground penetrating radar (GPR)techniques for this purpose. We applied GPR in reflection mode and zero-offset profiling (ZOP) Transmission mode on a precast concrete twin wall with built-in honeycombs. GPR measurements were performed as twochannel measurement with ground coupled antennas with centre frequencies of 1.5 GHz and 2.6 GHz mounted to an automated scanner system. Our findings show that ZOP transmission measurements are a more efficient method to detect voids in reinforced concrete structures compared to reflection mode measurements. This holds for both the effort needed for the measurement and the evaluation as well as the validity of the data. Honeycombs (basically representing voids) are usually characterized by strongly reduced amplitudes and earlier arrivals of the transmitted wave. T2 - NDT-CE 2015 - International symposium non-destructive testing in civil engineering CY - Berlin, Germany DA - 15.09.2015 KW - Ground penetrating radar KW - Reflection KW - Transmission KW - Reinforced concrete KW - Prefabricated wall KW - Void detection PY - 2015 SN - 1435-4934 SP - 324 EP - 344 PB - Technische Universität Berlin / Bundesanstalt für Materialforschung und -prüfung CY - Berlin, Germany AN - OPUS4-40006 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CHAP A1 - Rhode, Michael A1 - Münster, C. A1 - Mente, Tobias A1 - Böllinghaus, Thomas ED - Somerday, B.P. ED - Sofronis, P. T1 - Influence of experimental conditions and calculation method on hydrogen diffusion coefficient evaluation at elevated temperatures N2 - Literature provides a wide range of hydrogen diffusion coefficients for low alloyed steels used in power plants. In fact, experimental boundary conditions and calculation methods have influence on the determination of these coefficients. The diffusion and trapping behavior in creep-resistant steel 7CrMoVTiB10-10 has been studied. Based on experimental carrier gas hot extraction (CGHE) data, a numerical model has been developed to describe the hydrogen transport and respective hydrogen distribution at elevated temperatures. The numerical results suggest that common calculation methods for diffusion coefficients are limited for experimental data analysis. The sample preparation time before CGHE experiment influences the determined diffusion coefficients with the consequence that non-homogeneous hydrogen concentration profiles have to be considered in the simulations. KW - Temperature effect KW - Hydrogen diffusion KW - Creep-resistant steel KW - Hydrogen assisted cracking KW - Carrier gas hot extraction PY - 2017 SN - 978-0-7918-6138-7 DO - https://doi.org/10.1115/1.861387_ch56 SP - 495 EP - 503 PB - ASME CY - New York, USA ET - 1 AN - OPUS4-42502 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Dariz, P. A1 - Jakob, C. A1 - Ectors, D. A1 - Neubauer, J. A1 - Schmid, Thomas T1 - Measuring the Burning Temperatures of Anhydrite Micrograins in a High-Fired Medieval Gypsum Mortar N2 - Typical feature of high-fired medieval gypsum mortars is a compact microstructure of squat gypsum crystals containing firing products as remains of the calcination process. So far, the burning history of the binder is estimated based on morphological characteristics of the latter. A novel Raman microspectroscopy approach provides access to the calcination temperatures of individual anhydrite grains based on quantifiable spectroscopic changes appearing due to gradual variations of crystallinity, as independently confirmed by X-ray diffraction analysis of anhydrites synthesised at temperatures between 500°C and 900°C. The approach was successfully applied to the high-fired gypsum mortar of a South Tyrolean stucco sculpture of a pieta dated around 1420. Microparticles of burned anhydrite II with firing temperatures scattered around 650°C and clusters of thermally damaged natural anhydrite II crystals from the raw material were identified and imaged. KW - Analytical methods KW - Gypsum technology KW - High-fired gypsum mortar KW - Raman microspectroscopy KW - Thermal anhydrite PY - 2017 DO - https://doi.org/10.1002/slct.201701260 VL - 2 IS - 28 SP - 9153 EP - 9156 PB - Wiley VCH Verlag AN - OPUS4-42458 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schwenk, C. A1 - Kannengießer, Thomas A1 - Rethmeier, Michael T1 - Restraint conditions and welding resiudal stresses in self-restrained cold cracking test N2 - In the last decade, high-strength fine grained steels and welding consumables have gained a strong raise of application ranging from mobile cranes to bridge constructions. However, the cracking susceptibility of these steels increases significantly in correspondence with the achieved improvements in yield strength and the loss in plastic deformation reserves. In order to determine this behavior a series of different standardized cold cracking tests has been developed. One remaining major problem of these tests is the uncertainty about the quantitative intensity of the restraint conditions as well as the corresponding welding residual stresses. Consequently, the comparison of different tests and welding conditions as well as the transferability of the results onto real parts is difficult at best. The main topic of this paper is the analysis of the restraint conditions and their link with the welding induced residual stresses. The importance of the given standardized selfrestrained tests and first results about the transferability of results onto real parts are discussed. The influence of the test specimen geometry on the restraint conditions of the test is investigated for a selected test with numerical Simulation using commercial FEA software. Additionally, the residual stresses caused by the welding process are measured and linked with the restraint conditions which are defined mainly by the geometry parameters. Finally the transferability of the selected cold cracking test results is validated experimentally. The test results of a multilayer weld on high-strength fine grained steel of real size weldments are investigated. For these experiments a 16 MN large scale testing facility is used which is capable of applying the high reaction forces and clamping conditions found at large scale demonstrator parts. The results show the importance of the quantitative knowledge of the restraint conditions and the welding residual stresses on the cold cracking resistance. T2 - 8th International Conference on Trends in Welding Research CY - Pine Mountain, USA DA - 01.06.2008 KW - Cold Cracking Test KW - Intensity of Restraint PY - 2008 DO - https://doi.org/10.1361/cp2008twr766 SP - 766 EP - 771 PB - ASM international AN - OPUS4-47623 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kraffert, K. A1 - Karg, M. A1 - Schmack, R. A1 - Clavel, G. A1 - Boissiere, C. A1 - Wirth,, Thomas A1 - Pinna, N. A1 - Kraehnert, R. T1 - Stabilization of Mesoporous Iron Oxide Films against Sintering and Phase Transformations via Atomic Layer Deposition of Alumina and Silica N2 - The stabilization of crystal phases and nanostructured morphologies is an essential topic in application-driven design of mesoporous materials. Many applications, e.g. catalysis, require high temperature and humidity. Typical metal oxides transform under such conditions from a metastable, low crystal-line material into a thermodynamically more favorable form, i.e. from ferrihy-drite into hematite in the case of iron oxide. The harsh conditions induce also a growth of the crystallites constituting pore walls, which results in sintering and finally collapse of the porous network. Herein, a new method to stabi-lize mesoporous templated metal oxides against sintering and pore collapse is reported. The method employs atomic layer deposition (ALD) to coat the internal mesopore surface with thin layers of either alumina or silica. The authors demonstrate that silica exerts a very strong influence: It shifts hematite formation from 400 to 600 °C and sintering of hematite from 600 to 900 °C. Differences between the stabilization via alumina and silica are rationalized by a different interaction strength between the ALD material and the ferrihydrite film. The presented approach allows to stabilize mesoporous thin films that require a high crystallization temperature, with submonolayer quantity of an ALD material, and to apply mesoporous materials for high temperature applications. KW - Mesoporous oxides KW - Atomic layer deposition KW - Stabilization PY - 2018 DO - https://doi.org/10.1002/admi.201800360 VL - 5 IS - 14 SP - 1800360-1 EP - 1800360-9 PB - Wiley-VCH AN - OPUS4-47869 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Drexler, A.-K. A1 - Konert, Florian A1 - Nietzke, Jonathan A1 - Hodžić, E. A1 - Pastore, S. A1 - Domitner, J. A1 - Rhode, Michael A1 - Sommitsch, C. A1 - Böllinghaus, Thomas T1 - Effect of Tensile Loading and Temperature on the Hydrogen Solubility of Steels at High Gas Pressure N2 - The hydrogen solubility in ferritic and martensitic steels is affected by hydrostatic stress, pressure, and temperature. In general, compressive stresses decrease but tensile stresses increase the hydrogen solubility. This important aspect must be considered when qualifying materials for high‐pressure hydrogen applications (e.g., for pipelines or tanks) by using autoclave systems. In this work, a pressure equivalent for compensating the effect of compressive stresses on the hydrogen solubility inside of closed autoclaves is proposed to achieve solubilities that are equivalent to those in pipelines and tanks subjected to tensile stresses. Moreover, it is shown that the temperature effect becomes critical at low temperatures (e.g., under cryogenic conditions for storing liquid hydrogen). Trapping of hydrogen in the microstructure can increase the hydrogen solubility with decreasing temperature, having a solubility minimum at about room temperature. To demonstrate this effect, the generalized law of the hydrogen solubility is parameterized for different steels using measured contents of gaseous hydrogen. The constant parameter sets are verified and critically discussed with respect to the high‐pressure hydrogen experiments. KW - Hydrogen KW - Solubility KW - Temperature KW - Tensile loading KW - Analytical calculation PY - 2023 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-586701 DO - https://doi.org/10.1002/srin.202300493 SN - 1611-3683 SP - 1 EP - 9 PB - Wiley AN - OPUS4-58670 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Witte, Julien A1 - Schröpfer, Dirk A1 - Börner, Andreas A1 - Kannengießer, Thomas A1 - Michels, H. A1 - Hamm, C. A1 - Appelt, M. A1 - Hamacher, M. T1 - Ultraschallunterstütztes Fräsen zur Reduzierung der Belastung auf Werkzeug und Bauteiloberfläche von Eisenaluminid-Bauteilen N2 - Intermetallische Werkstoffe werden für Hochtemperaturanwendungen immer wichtiger. Insbesondere Aluminide mit hohen spezifischen Festigkeiten haben ein großes Potenzial für Leichtbauanwendungen, z. B. werden Titanaluminide bereits in Flugzeugturbinen eingesetzt. Ökonomische und ökologische Aspekte sind die treibende Kraft zur Substitution konventioneller Legierungen, z. B. Nickelbasislegierungen, die eine wesentlich höhere Kostenintensität und ein höheres Gewichts-Festigkeits-Verhältnis aufweisen. Insbesondere Eisenaluminide (FeAl) sind aufgrund guter mechanischer Eigenschaften und der guten Verfügbarkeit der wichtigsten Hauptlegierungselemente attraktiv. Speziell entwickelte FeAl-Legierungskonzepte ermöglichen eine wirtschaftliche Produktion im Kokillenguss, bei der die Erstarrung der Schmelze spezielle komplexe Gefüge ermöglicht, um die hohen thermischen und mechanischen Eigenschaften durch eine hohe Anzahl von harten Ausscheidungen entlang der Korngrenzen zu erreichen. Zu diesen Eigenschaften gehört aber auch, dass notwendige Bearbeitungsschritte, wie das Schlichtfräsen, zur Erzielung komplexer Endkonturen, zu vorzeitigem Werkzeugverschleiß und geringen Oberflächengüten führen. Für das finale FeAl-Bauteil ist eine hohe Oberflächenintegrität insbesondere in sicherheitsrelevanten Anwendungen in der Luftfahrt oder im Energiebereich erforderlich. Aus diesem Grund konzentriert sich die vorliegende Untersuchung auf die Mechanismen und die Minimierung des Werkzeugverschleißes und die Auswirkungen auf die Oberfläche eines in Kokille vergossenen FeAl-Bauteils. Neben den Optimierungen des Fräsprozesses und der Werkzeugparameter (Geometrie, Material) wird ein modernes hybrides Bearbeitungsverfahren, das ultra-schallunterstützte Fräsen (USAM), eingesetzt, bei dem eine Überlagerung mit einer hochfrequenten Schwingung des rotierenden Werkzeugs erzeugt wird. Analysen der Kräfte und Temperaturen im Fräsprozess, der Verschleißerscheinungen am Werkzeug und der Oberflächenintegrität zeigen positive Auswirkungen durch USAM. Darüber hinaus wird eine valide Grundlage für die Optimierung des Werkzeugs und des Fräsprozesses geschaffen, um eine hohe Oberflächenintegrität (z. B. Verringerung von Zugeigenspannungen und Defekten) und eine längere Werkzeuglebensdauer zu gewährleisten, die zukünftig eine wirtschaftliche Herstellung von FeAl-Bauteilen ermöglicht. T2 - 5. Symposium Materialtechnik CY - Clausthal-Zellerfeld, Germany DA - 23.02.2023 KW - Eisenaluminid KW - Ultraschallunterstütztes Fräsen KW - Werkzeugverschleiß KW - Oberflächenintegrität PY - 2023 VL - 12 SP - 738 EP - 748 PB - Shaker Verlag CY - Düren AN - OPUS4-59219 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Stephan, Ina A1 - Dimke, Thomas A1 - Guterman, R. A1 - Smith, C. A. A1 - Cataldo, V. A. T1 - Antibacterial and degradable thioimidazolium poly(ionic liquid) N2 - New antibacterial agents are urgently required to fight the emergence of antibiotic-resistant bacteria. We recently synthesized the first thioimidazolium ionene, which has antibacterial properties and can degrade in various media. This dual functionality is crucial in order to limit the environmental impact of these biocides. We have found that our polymer is stronger than benzalkonium chloride (BAC) against Pseudomonas aeruginosa and also readily degrades in the presence of base, while remaining stable in acidic environments. These results highlight a new emerging class of antibacterial degradable polymers. KW - Ionic liquid KW - Antibacterial polymer KW - Amphiphilic polymer KW - Thioimidazolium KW - Degradable polymer KW - Polyioinic liquid PY - 2020 DO - https://doi.org/10.1021/acssuschemeng.0c02666 VL - 8 IS - 22 SP - 8419 EP - 8424 PB - ACS Publications AN - OPUS4-50982 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Reed, B. P. A1 - Cant, D.J.H. A1 - Spencer, S.J. A1 - Carmona-Carmona, A. J. A1 - Bushell, A. A1 - Herrara-Gómez, A. A1 - Kurokawa, A. A1 - Thissen, A. A1 - Thomas, A.G. A1 - Britton, A.J. A1 - Bernasik, A. A1 - Fuchs, A. A1 - Baddorf, A.P. A1 - Bock, B. A1 - Thellacker, B. A1 - Cheng, B. A1 - Castner, D.G. A1 - Morgan, D.J. A1 - Valley, D. A1 - Willneff, E.A. A1 - Smith, E.P. A1 - Nolot, E. A1 - Xie, F. A1 - Zorn, G. A1 - Smith, G.C. A1 - Yasukufu, H. A1 - Fenton, J.L. A1 - Chen, J. A1 - Counsell, J.D.P. A1 - Radnik, Jörg A1 - Gaskell, K.J. A1 - Artyushkova, K. A1 - Yang, L. A1 - Zhang, L. A1 - Eguchi, M. A1 - Walker, M. A1 - Hajdyla, M. A1 - Marzec, M.M. A1 - Linford, M.R. A1 - Kubota, N. A1 - Cortazar-Martinez, O. A1 - Dietrich, P. A1 - Satoh, R. A1 - Schroeder, S.L.M. A1 - Avval, T.G. A1 - Nagatomi, T. A1 - Fernandez, V. A1 - Lake, W. A1 - Azuma, Y. A1 - Yoshikawa, Y. A1 - Compean-Gonzalez, C.L. A1 - Ceccone, G. A1 - Shard, A.G. T1 - ERRATUM: “Versailles project on advanced materials and standards interlaboratory study on intensity calibration for x-ray photoelectron spectroscopy instruments using low-density polyethylene” [J. Vac. Sci. Technol. A 38, 063208 (2020)] N2 - The lead authors failed to name two collaborators as co-authors. The authors listed should include: Miss Claudia L. Compean-Gonzalez (ORCID: 0000-0002-2367-8450) and Dr. Giacomo Ceccone (ORCID: 0000-0003-4637-0771). These co-authors participated in VAMAS project A27, provided data that were analyzed and presented in this publication (and supporting information), and reviewed the manuscript before submission. KW - X-ray photoelectron spectroscopy KW - Transmission function KW - Low-density polyethylene PY - 2021 DO - https://doi.org/10.1116/6.0000907 VL - 39 IS - 2 SP - 027001 PB - American Vacuum Society AN - OPUS4-52380 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Eschlböck-Fuchs, S. A1 - Huber, N. A1 - Ahamer, C. M. A1 - Hechenberger, J. G. A1 - Kolmhofer, P. J. A1 - Heitz, J. A1 - Rössler, R. A1 - Demidov, Alexander A1 - Schmid, Thomas A1 - Gornushkin, Igor B. A1 - Panne, Ulrich A1 - Pedarnig, J. D. T1 - Application of laser-induced breakdown spectroscopy for the analysis of slags in industrial steel production N2 - Laser-induced breakdown spectroscopy (LIBS) is a fast and versatile technique for (semi) quantitative element analysis of solids, liquids, gases, and particulate matter. The LIBS method is used for optical sensing in various branches of industrial production. In the contribution we review some of our recent results on LIBS analysis of slags from secondary metallurgy in industrial steel making. Major oxides in steel slags are measured at-line and after homogenization using a calibration-free (CF) method. Two approaches for CF analysis based on the Boltzmann plot method and on the calculation of synthetic spectra are compared for the analysis of quaternary oxides. We also present the research in cooperation with our industrial partners in the process-analytical chemistry network PAC. T2 - 11. Kolloquium Arbeitskreis Prozessanalytik CY - Vienna, Austria DA - 30.11.2015 KW - Laser-induced breakdown spectroscopy (LIBS) KW - Process analytical technology KW - Steel slag PY - 2015 PB - Plandruck+ Gesellschaft m.b.H. CY - Wien AN - OPUS4-39005 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Arnold, M. A1 - Katzmann, J. A1 - Naik, Aakash Ashok A1 - Görne, A. L. A1 - Härtling, Thomas A1 - George, Janine A1 - Schuster, C. T1 - Investigations on electron beam irradiated rare-earth doped SrF2 for application as low fading dosimeter material: Evidence for and DFT simulation of a radiation-induced phase N2 - A recent approach to measure electron radiation doses in the kGy range is the use of phosphors with an irradiation dose-dependent luminescence decay time. However, the applicability of the previously investigated material NaYF4:Yb3+,Er3+ is limited as it shows pronounced fading. Therefore, in this work, a modified SrF2 synthesis is presented that results in SrF2 nanoparticles codoped with Yb and either Er, Hm, or Tm. To assess their suitability as dosimeter material, dose response, as well as its degree of fading over 50 up to 140 days after irradiation were measured. Fading rates as small as 5% in SrF2:Er,Yb and 4% in SrF2:Ho,Yb were derived, which are comparable to established dosimeter materials. A combination of spectroscopy, diffraction and DFT calculations was used to elucidate the effect of irradiation, pointing towards the formation of a secondary phase of Yb2+ that we predict could be Yb2OF2. This irreversible formation of a secondary phase is considered to be the explanation for the low fading behavior in SrF2-based phosphors compared to NaYF4:Yb, Er, a highly attractive feature for electron beam dosimetry. KW - DFT KW - Structure prediction PY - 2022 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-554115 DO - https://doi.org/10.1039/D2TC01773C SN - 2050-7526 VL - 10 IS - 32 SP - 11579 EP - 11587 PB - RSC CY - London AN - OPUS4-55411 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Roesch, Philipp A1 - Vogel, Christian A1 - Wittwer, Philipp A1 - Huthwelker, T. A1 - Borca, C. A1 - Sommerfeld, Thomas A1 - Kluge, Stephanie A1 - Piechotta, Christian A1 - Kalbe, Ute A1 - Simon, Franz-Georg T1 - Taking a Look at the Surface: µ-XRF Mapping and Fluorine K-edge µ-XANES Spectroscopy of Organofluorinated Compounds in Environmental Samples and Consumer Products N2 - For the first time, µ-X-ray fluorescence (µ-XRF) mapping combined with fluorine K-edge µ-X-ray absorption near-edge structure (µ-XANES) spectroscopy was applied to depict per- and polyfluoroalkyl substances (PFAS) contamination and inorganic fluoride in samples concentrations down to 100 µg/kg fluoride. To demonstrate the matrix tolerance of the method, several PFAS contaminated soil and sludge samples as well as selected consumer product samples (textiles, food contact paper and permanent baking sheet) were investigated. µ-XRF mapping allows for a unique element-specific visualisation at the sample surface and enables localisation of fluorine containing compounds to a depth of 1 µm. Manually selected fluorine rich spots were subsequently analysed via fluorine K-edge µ-XANES spectroscopy. To support spectral interpretation with respect to inorganic and organic chemical distribution and compound class determination, linear combination (LC) fitting was applied to all recorded µ-XANES spectra. Complementarily, solvent extracts of all samples were target-analysed via LC-MS/MS spectrometry. The detected PFAS sum values range from 20 to 1136 µg/kg dry weight (dw). All environmentally exposed samples revealed higher concentration of PFAS with a chain length >C8 (e.g. 580 µg/kg dw PFOS for Soil1), whereas the consumer product samples showed a more uniform distribution with regard to chain lengths from C4 to C8. Independent from quantified PFAS amounts via target analysis, µ-XRF mapping combined with µ-XANES spectroscopy was successfully applied to detect both point-specific concentration maxima and evenly distributed surface coatings of fluorinated organic contaminants in the corresponding samples. KW - PFAS KW - XRF KW - LC-MS/MS KW - XANES KW - Fluoride KW - Soil PY - 2023 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-576109 DO - https://doi.org/10.1039/D3EM00107E SN - 2050-7887 SP - 1 EP - 12 PB - Royal Society of Chemistry AN - OPUS4-57610 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Vogel, Christian A1 - Roesch, Philipp A1 - Wittwer, Philipp A1 - Piechotta, Christian A1 - Lisec, Jan A1 - Sommerfeld, Thomas A1 - Kluge, Stephanie A1 - Herzel, Hannes A1 - Huthwelker, T. A1 - Borca, C. A1 - Simon, Franz-Georg T1 - Levels of per- and polyfluoroalkyl substances (PFAS) in various wastewater-derived fertilizers – analytical investigations from different perspectives N2 - Solid wastewater-based fertilizers were screened for per- and polyfluoroalkyl substances (PFAS) by the extractable organic fluorine (EOF) sum parameter method. The EOF values for ten sewage sludges from Germany and Switzerland range from 154 to 7209 mg kg−1. For thermal treated sewage sludge and struvite the EOF were lower with values up to 121 mg kg−1. Moreover, the application of PFAS targeted and suspect screening analysis of selected sewage sludge samples showed that only a small part of the EOF sum parameter values can be explained by the usually screened legacy PFAS. The hitherto unknown part of EOF sum parameter contains also fluorinated pesticides, pharmaceutical and aromatic compounds. Because these partly fluorinated compounds can degrade to (ultra-)short PFAS in wastewater treatment plants they should be considered as significant sources of organic fluorine in the environment. The combined results of sum parameter analysis and suspect screening reveal the need to update current regulations, such as the German fertilizer ordinance, to focus not solely on a few selected PFAS such as perfluorooctane sulfonic acid (PFOS) and perfluorooctanoic acid (PFOA) but consider an additional sum parameter approach as a more holistic alternative. Moreover, diffusion gradient in thin-films (DGT) passive samplers were utilized as an alternative simplified extraction method for PFAS in solid wastewater-based fertilizers and subsequently quantified via combustion ion chromatography. However, the DGT method was less sensitive and only comparable to the EOF values of the fertilizers in samples with >150 mg kg−1, because of different diffusion properties for various PFAS, but also kinetic exchange limitations. KW - Combustion Ion Chromatography KW - Per- and Polyfluoroalkyl substances (PFAS) KW - Sewage sludge KW - Fertilizer PY - 2023 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-583429 DO - https://doi.org/10.1039/d3va00178d VL - 2 IS - 10 SP - 1436 EP - 1445 PB - Royal Society of Chemistry (RSC) AN - OPUS4-58342 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Baytekin, H.T. A1 - Baytekin, B. A1 - Schulz, a. A1 - Springer, A. A1 - Gross, Thomas A1 - Unger, Wolfgang A1 - Artamonova, M. A1 - Schlecht, S. A1 - Lentz, D. A1 - Schalley, C.A. T1 - Metallo-supramolecular nanospheres via hierarchical self-assembly N2 - A novel coordination oligo/polymer is synthesized by metal-directed self-assembly from equimolar amounts of the (dppp)M(OTf)2 precursor complexes (dppp = bis-(diphenylphosphino)-propane, OTf = triflate; M = PdII or M = PtII) and banana-shaped bidentate dipyridyl ligands. The assemblies were characterized by ESI mass spectrometry and NMR spectroscopy. The analysis of the cloudy suspension prepared by dissolving the coordination polymer in aqueous methanol solutions indicates nanosized spherical objects to form. Evidence for vesicle formation from these metallo-supramolecular oligomers comes from (cryogenic) transmission electron microscopy (TEM, cryo-TEM). Atomic force microscopy revealed stable nanospheres on hydrophilic mica and monolayer formation on hydrophobic highly oriented pyrolitic graphite (HOPG) substrates. On mica, also torus-shaped object were observed, which are rationalized by vesicles that opened during the drying procedure and released the internal solvent. Elemental analysis of the nanoassemblies by X-ray photoelectron spectroscopy (XPS) indicates uncoordinated and coordinated pyridines in the coordination polymers that form the nanospheres. Various control experiments using different metal centers and modified ligands support the conclusions. KW - Self-assembly KW - Metallo-supramolecular chemistry KW - Coordination polymers KW - Vesicles KW - Electron microscopy KW - Nano-materials PY - 2009 DO - https://doi.org/10.1021/cm900642p SN - 0897-4756 SN - 1520-5002 VL - 21 IS - 13 SP - 2980 EP - 2992 PB - American Chemical Society CY - Washington, DC AN - OPUS4-19638 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Welzel, F. A1 - Grunewald, Thomas A1 - Beyer, M. A1 - Grätz, Rainer A1 - Klages, C.-P. T1 - Mechanisch erzeugte Reib- und Schlagfunken im Vergleich T2 - 12. Kolloquium zu Fragen der chemischen und physikalischen Sicherheitstechnik CY - Berlin, Deutschland DA - 2010-06-15 PY - 2010 SN - 978-3-9813550-1-7 SN - 0938-5533 SP - 32 EP - 36 PB - BAM Bundesanstalt für Materialforschung und -prüfung CY - Berlin AN - OPUS4-21266 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Drexler, A A1 - Konert, Florian A1 - Sobol, Oded A1 - Rhode, Michael A1 - Domitner, J A1 - Sommitsch, C A1 - Boellinghaus, Thomas T1 - Enhanced gaseous hydrogen solubility in ferritic and martensitic steels at low temperatures N2 - Metals that are exposed to high pressure hydrogen gas may undergo detrimental failure by embrittlement. Understanding the mechanisms and driving forces of hydrogen absorption on the surface of metals is crucial for avoiding hydrogen embrittlement. In this study, the effect of stress-enhanced gaseous hydrogen uptake in bulk metals is investigated in detail. For that purpose, a generalized form of Sievert's law is derived from thermodynamic potentials considering the effect of microstructural trapping sites and multiaxial stresses. This new equation is parametrized and verified using experimental data for carbon steels, which were charged under gaseous hydrogen atmosphere at pressures up to 1000 bar. The role of microstructural trapping sites on the parameter identification is critically discussed. KW - Hydrogen KW - Thermodynamic modelling KW - Pressure-dependent solubility KW - Steel KW - Trapping PY - 2022 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-559307 DO - https://doi.org/10.1016/j.ijhydene.2022.09.109 SN - 0360-3199 VL - 47 IS - 93 SP - 39639 EP - 39653 PB - Elsevier Ltd. AN - OPUS4-55930 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Heinrich, Thomas A1 - Traulsen, Christoph Hans-Henning A1 - Darlatt, Erik A1 - Richter, S. A1 - Poppenberg, J. A1 - Traulsen, N.L. A1 - Linder, I. A1 - Lippitz, Andreas A1 - Dietrich, Paul A1 - Dib, B. A1 - Unger, Wolfgang A1 - Schalley, C.A. T1 - The versatility of 'Click' reactions at surfaces: Molecular recognition at interfaces N2 - In order to investigate molecular recognition on surfaces, an azide-functionalized monolayer was deposited on gold. The monolayer was characterized by X-ray photoelectron spectroscopy (XPS) and angle-resolved near-edge X-ray absorption fine structure (NEXAFS) experiments and the decomposition of the azide upon irradiation with X-ray beams was investigated. Subsequently, various alkyne-functionalized host and guest molecules were attached to the azide by 1,3-dipolar cycloaddition. These modified surfaces and their host–guest chemistry were analysed by XPS and angle-resolved NEXAFS. The reversibility of guest binding was shown for one example as a proof of principle. KW - 'Click' reaction KW - Azide-terminated surfaces KW - SAMs KW - Host guest molecules KW - Molecular recognition at interfaces PY - 2014 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-306463 DO - https://doi.org/10.1039/C4RA01730G SN - 2046-2069 VL - 4 IS - 34 SP - 17694 EP - 17702 PB - RSC Publishing CY - London AN - OPUS4-30646 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Girard-Lauriault, Pierre-Luc A1 - Ruiz, J.-C. A1 - Gross, Thomas A1 - Wertheimer, M. R. A1 - Unger, Wolfgang T1 - Ultra-shallow chemical characterization of organic thin films deposited by plasma and vacuum-ultraviolet, using angle- and excitation energy-resolved XPS N2 - Nitrogen (N)-rich organic thin films were deposited using both low-pressure plasma- and vacuum-ultraviolet-based techniques, from mixtures of ammonia (NH3) and ethylene (C2H4). These films were investigated using angle-resolved and excitation energy resolved X-ray photoelectron spectroscopy (ARXPS and ERXPS, respectively) in order to determine their sub-surface chemical profiles. These two techniques enable one to tune the “XPS 95%” information depth, z 95%, by varying either the angle or the excitation energy. Using a combination of both techniques, z 95% can be varied continuously from 0.7 to 11 nm. The surface-near chemistry is investigated using both high-resolution C 1s spectra and elemental concentrations derived from elemental peak intensities. Results show that while laboratory XPS, and even ARXPS, suggest homogenous surface chemistries, the novel combination of ARXPS and ERXPS points to the existence of a compositional profile in the extreme outer surface layer. Our conclusions are supported by simulations using SESSA software. KW - Plasma polymers KW - Vacuum ultraviolet photopolymers KW - Synchrotron XPS KW - Depth profile PY - 2011 DO - https://doi.org/10.1007/s11090-011-9306-3 SN - 0272-4324 VL - 31 IS - 4 SP - 535 EP - 550 PB - Plenum Publ. Corp. CY - New York, NY, USA AN - OPUS4-23993 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Heinrich, Thomas A1 - Traulsen, Christoph Hans-Henning A1 - Holzweber, Markus A1 - Richter, S. A1 - Kunz, V. A1 - Kastner, S.K. A1 - Krabbenborg, S.O. A1 - Huskens, J. A1 - Unger, Wolfgang A1 - Schalley, C.A. T1 - Coupled molecular switching processes in ordered mono- and multilayers of stimulus-responsive rotaxanes on gold surfaces N2 - Interfaces provide the structural basis for function as, for example, encountered in nature in the membrane-embedded photosystem or in technology in solar cells. Synthetic functional multilayers of molecules cooperating in a coupled manner can be fabricated on surfaces through layer-by-layer self-assembly. Ordered arrays of stimulus-responsive rotaxanes undergoing well-controlled axle shuttling are excellent candidates for coupled mechanical motion. Such stimulus-responsive surfaces may help integrate synthetic molecular machines in larger systems exhibiting even macroscopic effects or generating mechanical work from chemical energy through cooperative action. The present work demonstrates the successful deposition of ordered mono- and multilayers of chemically switchable rotaxanes on gold surfaces. Rotaxane mono- and multilayers are shown to reversibly switch in a coupled manner between two ordered states as revealed by linear dichroism effects in angle-resolved NEXAFS spectra. Such a concerted switching process is observed only when the surfaces are well packed, while less densely packed surfaces lacking lateral order do not exhibit such effects. KW - Molecular machine KW - Rotaxane KW - LBL growth KW - XPS KW - NEXAFS KW - SIMS PY - 2015 DO - https://doi.org/10.1021/ja512654d SN - 0002-7863 SN - 1520-5126 VL - 137 IS - 13 SP - 4382 EP - 4390 PB - American Chemical Society CY - Washington, DC, USA AN - OPUS4-33077 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Rodrigues, A.C.P. A1 - Österle, Werner A1 - Gradt, Thomas A1 - Azevedo, César Roberto de Farias T1 - Impact of copper nanoparticles on tribofilm formation determined by pin-on-disc tests with powder supply: Addition of artificial third body consisting of Fe3O4, Cu and graphite N2 - Copper, magnetite and graphite particles were mixed in order to observe their impact on the coefficient of friction (CoF) during pin-on-disc tests and on the tribofilm formation after testing. Pure magnetite powder provided a value of CoF of 0.4. Magnetite-copper mixtures tested at 400 °C revealed lower CoF values (~0.4) than those at room temperature (~0.6). Magnetite-graphite and magnetite-graphite-copper mixtures presented lower CoF values (~0.3). All systems formed a magnetite-based tribofilm and patches of metallic copper were found on the tribosurfaces of the mixtures containing copper. Carbon layers and graphite nanoinclusions were observed in the graphite mixtures. The incorporation of zirconia particles, a by-product of ball milling mixing, prevented the selective transfer of graphite and copper to the tribosurfaces of some of the samples. KW - Brake pad materials KW - Sliding friction KW - Transfer layer KW - Surface analysis KW - Model friction tests PY - 2017 DO - https://doi.org/10.1016/j.triboint.2017.02.014 SN - 0301-679X VL - 110 SP - 103 EP - 112 PB - Elsevier Ltd. CY - Amsterdam AN - OPUS4-40104 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Gers-Panther, C.F. A1 - Fischer, H. A1 - Nordmann, J. A1 - Seiler, T. A1 - Behnke, Thomas A1 - Würth, Christian A1 - Frank, W. A1 - Resch-Genger, Ute A1 - Müller, T.J.J. T1 - Four- and Five-Component Syntheses and Photophysical Properties of Emission Solvatochromic 3‑Aminovinylquinoxalines N2 - 3-Aminovinylquinoxalines are readily accessible from (hetero)aryl glyoxylic acids or heterocyclic π-nucleophiles by consecutive four- and fivecomponent syntheses in the sense of an activation-alkynylation-cyclocondensation-addition sequence or glyoxylation-alkynylation-cyclocondensation-addition sequence in good yields. The title compounds are highly fluorescent with pronounced emission solvatochromicity and protochromic fluorescence quenching. Time-resolved fluorescence spectroscopy furnishes radiative and nonradiative fluorescence decay rates in various solvent polarities. The electronic structure is corroborated by DFT and TD-DFT calculations rationalizing the observed spectroscopic effects. KW - Dye KW - Syntheseis KW - Spectroscopy PY - 2016 DO - https://doi.org/10.1021/acs.joc.6b02581 SN - 0022-3263 VL - 82 SP - 567 EP - 578 PB - ACS Publications AN - OPUS4-39211 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Reed, B. P. A1 - Cant, D.J.H. A1 - Spencer, J. A1 - Carmona-Carmona, A. J. A1 - Bushell, A. A1 - Herrara-Gómez, A. A1 - Kurokawa, A. A1 - Thissen, A. A1 - Thomas, A.G. A1 - Britton, A.J. A1 - Bernasik, A. A1 - Fuchs, A. A1 - Baddorf, A. P. A1 - Bock, B. A1 - Thellacker, B. A1 - Cheng, B. A1 - Castner, D.G. A1 - Morgan, D.J. A1 - Valley, D. A1 - Willneff, E.A. A1 - Smith, E.F. A1 - Nolot, E. A1 - Xie, F. A1 - Zorn, G. A1 - Smith, G.C. A1 - Yasukufu, H. A1 - Fenton, J. L. A1 - Chen, J. A1 - Counsell, J..D.P. A1 - Radnik, Jörg A1 - Gaskell, K.J. A1 - Artyushkova, K. A1 - Yang, L. A1 - Zhang, L. A1 - Eguchi, M. A1 - Walker, M. A1 - Hajdyla, M. A1 - Marzec, M.M. A1 - Linford, M.R. A1 - Kubota, N. A1 - Cartazar-Martínez, O. A1 - Dietrich, P. A1 - Satoh, R. A1 - Schroeder, S.L.M. A1 - Avval, T.G. A1 - Nagatomi, T. A1 - Fernandez, V. A1 - Lake, W. A1 - Azuma, Y. A1 - Yoshikawa, Y. A1 - Shard, A.G. T1 - Versailles Project on Advanced Materials and Standards interlaboratory study on intensity calibration for x-ray photoelectron spectroscopy instruments using low-density polyethylene N2 - We report the results of a Versailles Project on Advanced Materials and Standards interlaboratory study on the intensity scale calibration of x-ray photoelectron spectrometers using low-density polyethylene (LDPE) as an alternative material to gold, silver, and copper. An improved set of LDPE reference spectra, corrected for different instrument geometries using a quartz-monochromated Al Kα x-ray source, was developed using data provided by participants in this study. Using these new reference spectra, a transmission function was calculated for each dataset that participants provided. When compared to a similar calibration procedure using the NPL reference spectra for gold, the LDPE intensity calibration method achieves an absolute offset of ∼3.0% and a systematic deviation of ±6.5% on average across all participants. For spectra recorded at high pass energies (≥90 eV), values of absolute offset and systematic deviation are ∼5.8% and ±5.7%, respectively, whereas for spectra collected at lower pass energies (<90 eV), values of absolute offset and systematic deviation are ∼4.9% and ±8.8%, respectively; low pass energy spectra perform worse than the global average, in terms of systematic deviations, due to diminished count rates and signal-to-noise ratio. Differences in absolute offset are attributed to the surface roughness of the LDPE induced by sample preparation. We further assess the usability of LDPE as a secondary reference material and comment on its performance in the presence of issues such as variable dark noise, x-ray warm up times, inaccuracy at low count rates, and underlying spectrometer problems. In response to participant feedback and the results of the study, we provide an updated LDPE intensity calibration protocol to address the issues highlighted in the interlaboratory study. We also comment on the lack of implementation of a consistent and traceable intensity calibration method across the community of x-ray photoelectron spectroscopy (XPS) users and, therefore, propose a route to achieving this with the assistance of instrument manufacturers, metrology laboratories, and experts leading to an international standard for XPS intensity scale calibration. KW - X-ray photoelectron spectroscopy KW - Transmission function KW - Intensity scale calibration KW - Reference spectra KW - Low-density polyethylene (LDPE) PY - 2020 DO - https://doi.org/10.1116/6.0000577 VL - 38 IS - 6 SP - 063208 AN - OPUS4-51655 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Füllenbach, L.C. A1 - Perez, J. P. H. A1 - Freeman, H.M. A1 - Thomas, A.N. A1 - Mayanna, S. A1 - Parker, J. E. A1 - Göttlicher, J. A1 - Steininger, R. A1 - Radnik, Jörg A1 - Benning, L.G. A1 - Oelkers, E.H. T1 - Nanoanalytical Identification of Siderite Dissolution-Coupled Pb Removal Mechanisms from Oxic and Anoxic Aqueous Solutions N2 - Lead(II) is a toxic pollutant often found in metalcontaminated soils and wastewaters. In acidic aqueous environments, Pb(II) is highly mobile. Chemical treatment strategies of such systems therefore often include neutralization agents and metal sorbents. Since metal solubility and the retention potential of sorbents depend on the redox state of the aqueous system, we tested the efficiency of the naturally occurring redox-sensitive ferrous iron carbonate mineral siderite to remove Pb(II) from acidic aqueous solutions in batch experiments under oxic and anoxic conditions over a total of 1008 h. Siderite dissolution led to an increase in reactive solution pH from 3 to 5.3 and 6.9, while 90 and 100% of the initial aqueous Pb(II) (0.48 × 10−3 mol kg−1) were removed from the oxic and anoxic systems, respectively. Scanning and transmission electron microscopy, combined with X-ray absorption and photoelectron spectroscopy, indicated that under oxic conditions, Pb(II) was consumed by cerussite precipitation and inner-sphere surface complexation to secondary goethite. Under anoxic conditions, Pb(II) was removed by the rapid precipitation of cerussite. This efficient siderite dissolution-coupled sequestration of Pb(II) into more stable solid phases demonstrates this potential method for contaminated water Treatment regardless of the redox environment. KW - Siderite KW - X-ray absorption spectroscopy KW - X-ray photoelectron spectroscopy KW - Wastewater treatment PY - 2020 DO - https://doi.org/10.1021/acsearthspacechem.0c00180 VL - 4 IS - 11 SP - 1966 EP - 1977 PB - ACS Publication AN - OPUS4-51961 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -