TY - RPRT A1 - Kühn, B. A1 - Lukic, M. A1 - Nussbaumer, A. A1 - Günther, H.P. A1 - Helmerich, Rosemarie A1 - Herion, S. A1 - Kolstein, M.H. A1 - Walbridge, S. A1 - Androic, B. A1 - Dijkstra, O. A1 - Bucak, Ö. A1 - Sedlacek, G. A1 - Bijlaard, F. A1 - Géradin, M. A1 - Pinto, A. A1 - Dimova, S. T1 - Assessment of existing steel structures - Recommendations for estimation of remaining fatigue life KW - Assessment KW - Existing steel structures PY - 2008 SN - 1018-5593 SP - 1 EP - 108 PB - Office for Official Publications of the European Communities CY - Luxembourg AN - OPUS4-17556 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Klobes, Peter A1 - Minor, D. B. A1 - Röhl-Kuhn, B. A1 - Zimathies, Annett A1 - Prinz, C. A1 - Leigh, S. D. A1 - Heckert, N. A. A1 - MacDonald, B. S. T1 - Porosimetrie-Standard NIST SRM 1917 / CRM BAM-P 127 - Das erste von NIST und BAM gemeinsam zertifizierte Referenzmaterial T2 - 6. Workshop über die Charakterisierung von Feinteiligen und Porösen Festkörpern CY - Bad Soden, Deutschland DA - 2002-11-14 PY - 2002 CY - Bad Soden AN - OPUS4-1500 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Friedrich, Jörg Florian A1 - Kühn, Gerhard A1 - Schulz, Ulrich A1 - Jansen, Kirsten A1 - Möller, B. A1 - Fischer, S. T1 - Fluorination of Polymer Surfaces PY - 2002 SN - 0947-076X SN - 1522-2454 VL - 14 IS - 5 SP - 285 EP - 290 PB - Wiley-VCH Verl. CY - Weinheim AN - OPUS4-1466 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Friedrich, Jörg Florian A1 - Kühn, Gerhard A1 - Schulz, Ulrich A1 - Jansen, Kirsten A1 - Bertus, Angela A1 - Fischer, S. A1 - Möller, B. T1 - Characterization of fluorinated polyethylene surfaces N2 - Polyethylene foils, used as greenhouse foils stabilized with various types of sterically hindered amine light stabilizers (HALS), showed an extraordinary prolonged lifetime on exposure to natural or artificial weathering if a gas-phase fluorination under low-pressure conditions was applied. The fluorination was performed using F2/N2 mixtures and provided ca. 50 F/100 C (fluorination degree ap25%). The lifetimes of fluorinated PE foils on exposure to artificial or natural weathering were increased at least by a factor of 2-4 as measured in terms of tensile strength and elongation at break. KW - Gas phase fluorination of PE KW - Fluorination kinetics KW - Weathering PY - 2003 DO - https://doi.org/10.1163/156856103322113832 SN - 0169-4243 SN - 1568-5616 VL - 17 IS - 8 SP - 1127 EP - 1143 PB - VNU Science Press CY - Utrecht AN - OPUS4-2707 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Darlatt, Erik A1 - Traulsen, C.H.-H. A1 - Poppenberg, J. A1 - Richter, S. A1 - Kühn, Julius A1 - Schalley, C.A. A1 - Unger, Wolfgang T1 - Evidence of click and coordination reactions on a self-assembled monolayer by synchrotron radiation based XPS and NEXAFS N2 - An ethynylterpyridine was 'clicked' to an azide-terminated self-assembled monolayer on gold and characterized by synchrotron radiation based surface analysis as NEXAFS and XPS. The detection of azide and terpyridine signatures confirmed a partial click reaction at room temperature. The absence of the azides after reaction at 50 °C indicates an almost complete conversion. For the latter case successful Pd(II) coordination has been proven. The Au–S interface of the SAMs has been characterized by S 1s and S 2p XPS. KW - Synchrotron radiation XPS KW - NEXAFS spectroscopy KW - Surface click chemistry KW - Self-assembled monolayer KW - HAXPES KW - XANES PY - 2012 DO - https://doi.org/10.1016/j.elspec.2012.02.004 SN - 0368-2048 SN - 1873-2526 VL - 185 IS - 3-4 SP - 85 EP - 89 PB - Elsevier CY - Amsterdam AN - OPUS4-25596 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Linke, S. A1 - Kühn, Julius A1 - Nörthemann, K. A1 - Unger, Wolfgang A1 - Moritz, W. T1 - Sensor high throughput screening using photocurrent measurements in silicon N2 - A new high throughput screening method to characterise alloys used as gate metal of Metal/solid Electrolyte/Insulator/Semiconductor (MEIS) gas-sensors was developed. Samples with continuous gradients in alloy concentration for the system Pd1-x-yNiyCoy were analysed regarding H2 sensitivity. First results showed reduced poisoning effects of H2S for Ni concentrations between 4-11 at-% in Pd. T2 - Eurosensors XXVI CY - Kraków, Poland DA - 2012-09-09 KW - LAPS KW - Ternary alloy KW - MEIS sensor KW - H2 sensor KW - High throughput screening PY - 2012 DO - https://doi.org/10.1016/j.proeng.2012.09.366 SN - 1877-7058 VL - 47 SP - 1195 EP - 1198 PB - Elsevier CY - Amsterdam [u.a.] AN - OPUS4-27926 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Darlatt, Erik A1 - Nefedov, A. A1 - Traulsen, C.H.-H. A1 - Poppenberg, J. A1 - Richter, S. A1 - Dietrich, Paul A1 - Lippitz, Andreas A1 - Illgen, René A1 - Kühn, Julius A1 - Schalley, C.A. A1 - Wöll, Ch. A1 - Unger, Wolfgang T1 - Interperetation of experimental N K NEXAFS of azide, 1,2,3-triazole and terpyridyl groups by DFT spectrum simulations N2 - Experimental N K-edge NEXAFS data of surface immobilized azide, 1,2,3-triazole and terpyridyl groups are interpreted with the help of DFT spectrum simulations. Assignments of π* resonances in experimental N K-edge NEXAFS spectra to nitrogen atoms within these functional groups have been made. The azide was immobilized on gold as the head group of a thiol SAM, 1,2,3-triazole was formed on this SAM by click reaction and terpyridyl groups were introduced as substituents of the acetylene used for the click reaction. For azide-terminated molecules, DFT spectrum simulations are found to be useful to find measurement conditions delivering experimental N K-edge NEXAFS data with negligible X-ray damage. The 1,2,3-triazole group is found to be rather stable under X-ray irradiation. KW - N K-edge NEXAFS KW - XANES KW - Surface click chemistry KW - Density functional theory KW - Azide KW - 1,2,3-Triazole PY - 2012 DO - https://doi.org/10.1016/j.elspec.2012.09.008 SN - 0368-2048 SN - 1873-2526 VL - 185 IS - 12 SP - 621 EP - 624 PB - Elsevier CY - Amsterdam AN - OPUS4-27774 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kühn, B. A1 - Helmerich, Rosemarie A1 - Nussbaumer, A. A1 - Günther, H.-P. A1 - Herion, S. T1 - Beurteilung bestehender Stahltragwerke: Empfehlungen zur Abschätzung der Restnutzungsdauer N2 - Die zunehmende Bedeutung der Nachhaltigkeit im Bauwesen wird in Zukunft das Bauen im Bestand gegenüber Neubauten in den Vordergrund rücken. Dies gilt auch für den Brückenbau, wo das Qualitätsmanagement seit langem Brücken von ihrem Entstehungsgang über den Betrieb bis in die Entsorgung begleitet. Die starke Vergrößerung der Frachtvolumina für Straße und Schiene und die zunehmende Überalterung des Brückenbestandes fragen danach, ob die bestehenden Brücken für die veränderten Betriebsbedingungen noch geeignet sind und wie sie und ob sie dafür instandgesetzt werden könnten. Für die erforderlichen Instandhaltungs- und Instandsetzungsmaßnahmen oder einen eventuellen Ersatz durch einen Neubau ist aber die Frage der Restnutzungsdauer von entscheidender Bedeutung. Es ist daher nicht von ungefähr, dass sich Baulast-träger auf nationaler und internationaler Ebene frühzeitig zusammengetan haben, um nach geeigneten Methoden der Bestimmung der Sicherheit und Restnutzungsdauer bestehender Brücken zu forschen. Auch die internationalen technisch-wissenschaftlichen Verbände wie EKS und fib sowie die Standard-Organisationen ISO und CEN sind der Frage eines internationalen Austauschs und der Vereinheitlichung der Methoden nachgegangen. Für Stahlbrücken hat insbesondere das technische Komitee6 - Ermüdung - der EKS Anregungen aufgegriffen, aus den verschiedenen nationalen Erfahrungen und dem vorhandenen Wissen technische Empfehlungen für die Beurteilung bestehender Stahlbrücken zu entwickeln [1], die sich als Grundlage für die von CEN/TC 250 - das CEN-Komitee für die Bearbeitung der Eurocode - geplante Erweiterung der Eurocode zur Instandhaltung und Instandsetzung des Brückenbestandes eignen. Das Ergebnis ist ein technisch-wissenschaftlicher Bericht, der im Rahmen der Zusammenarbeit der europäischen Kommission (DG-Research - Joint Research Centre JRC) mit der EKS als Basispapier für eine zukünftige Eurocode-Erweiterung veröffentlicht wurde und schon jetzt als Empfehlung für eine Vorgehensweise nach dem Stand der Technik verwendet werden kann. Der vorliegende Beitrag behandelt die Grundzüge dieses Berichtes [1], der vom e-bookshop der Kommission kostenfrei herunter geladen werden kann. PY - 2008 DO - https://doi.org/10.1002/stab.200810072 SN - 0038-9145 SN - 1437-1049 SN - 0932-6375 VL - 77 IS - 8 SP - 595 EP - 607 PB - Ernst CY - Berlin AN - OPUS4-17893 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kühn, Julius A1 - Hodoroaba, Vasile-Dan A1 - Linke, S. A1 - Moritz, W. A1 - Unger, Wolfgang T1 - Characterization of Pd-Ni-Co alloy thin films by ED-EPMA with application of the STRATAGEM software N2 - Ternary thin film alloys based on Pd, Ni and Co on silicon wafers have been characterized in order to determine elemental composition and thickness. A broad variety of alloy compositions was obtained on one and the same substrate by magnetron dc-co-sputter deposition. Energy-dispersive electron probe X-ray microanalysis of these 'multi' alloy composition samples is performed in a non-destructive, precise and, if optimized, also in a time-saving way. The local thickness of the layers under study was in between 50 nm and 250 nm. Pure element bulk materials have been employed as reference specimens. The results attained in this study are compared to those obtained by other analytical methods as Auger electron spectroscopy and X-ray photo electron spectroscopy. KW - Ternary alloys KW - Film thickness KW - Elemental composition KW - Quantification KW - K-values KW - ED-EPMA KW - STRATAGEM PY - 2012 DO - https://doi.org/10.1002/sia.4974 SN - 0142-2421 SN - 1096-9918 VL - 44 IS - 11-12 SP - 1456 EP - 1458 PB - Wiley CY - Chichester AN - OPUS4-27273 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Schoetz, U. A1 - Deliolanis, N.C. A1 - Ng, D. A1 - Pauli, Jutta A1 - Resch-Genger, Ute A1 - Kühn, E. A1 - Heuer, S. A1 - Beisker, W. A1 - Köster, R.W. A1 - Zitzelsberger, H. A1 - Caldwell, R.B. T1 - Usefulness of a Darwinian system in a biotechnological application: evolution of optical window fluorescent protein variants under selective pressure N2 - With rare exceptions, natural evolution is an extremely slow process. One particularly striking exception in the case of protein evolution is in the natural production of antibodies. Developing B cells activate and diversify their immunoglobulin (Ig) genes by recombination, gene conversion (GC) and somatic hypermutation (SHM). Iterative cycles of hypermutation and selection continue until antibodies of high antigen binding specificity emerge (affinity maturation). The avian B cell line DT40, a cell line which is highly amenable to genetic manipulation and exhibits a high rate of targeted integration, utilizes both GC and SHM. Targeting the DT40's diversification machinery onto transgenes of interest inserted into the Ig loci and coupling selective pressure based on the desired outcome mimics evolution. Here we further demonstrate the usefulness of this platform technology by selectively pressuring a large shift in the spectral properties of the fluorescent protein eqFP615 into the highly stable and advanced optical imaging expediting fluorescent protein Amrose. The method is advantageous as it is time and cost effective and no prior knowledge of the outcome protein's structure is necessary. Amrose was evolved to have high excitation at 633 nm and excitation/emission into the far-red, which is optimal for whole-body and deep tissue imaging as we demonstrate in the zebrafish and mouse model. KW - Fluorescent protein KW - Quantum yield PY - 2014 DO - https://doi.org/10.1371/journal.pone.0107069 SN - 1932-6203 VL - 9 IS - 9 SP - e107069-1 EP - e107069-12 PB - PubMed Central AN - OPUS4-31976 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Tamberg, D. A1 - Thiele, D. A1 - Brodda, B. G. A1 - Lammertz, H. A1 - Coerdt, W. A1 - Mainka, E. A1 - Görgenyi, T. A1 - Stütz, A. A1 - Aigner, H. A1 - Deron, S. A1 - Kuhn, E. T1 - Evaluation of an interlaboratory comparison of the chemical assay of U, Th oxide coated particles PY - 1981 SN - 92-0-179081-3 N1 - Serientitel: IAEA safeguards – Series title: IAEA safeguards IS - 3 SP - 1 EP - 38 PB - IAEA CY - Wien AN - OPUS4-33362 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kuner, Maximilian A1 - Kühn, S. A1 - Haase, H. A1 - Meyer, Klas A1 - Koch, Matthias T1 - Cleaving Ergot Alkaloids by Hydrazinolysis - A Promising Approach for a Sum Parameter Screening Method N2 - Ergot alkaloids are mycotoxins formed by fungi of the Claviceps genus, which are some of the most common contaminants of food and feed worldwide. These toxins are a structurally heterogeneous group of compounds, sharing an ergoline backbone. Six structures and their corresponding stereoisomers are typically quantified by either HPLC-FLD or HPLC-MS/MS and the values subsequently summed up to determine the total ergot alkaloid content. For the development of a screening method targeting all ergot alkaloids simultaneously, the alkaloids need to be transferred to one homogeneous structure: a lysergic acid derivative. In this study, two promising cleaving methods—acidic esterification and hydrazinolysis—are compared, using dihydroergocristine as a model compound. While the acidic esterification proved to be unsuitable, due to long reaction times and oxidation sensitivity, hydrazinolysis reached a quantitative yield in 40-60 min. Parallel workup of several samples is possible. An increasing effect on the reaction rate by the addition of ammonium iodide was demonstrated. Application of hydrazinolysis to a major ergot alkaloid mix solution showed that all ergopeptines were cleaved, but ergometrine/-inine was barely affected. Still, hydrazinolysis is a suitable tool for the development of a sum parameter screening method for ergot alkaloids in food and feed. KW - Ergot alkaloids KW - Sum parameter method KW - Hydrazinolysis KW - Esterification PY - 2021 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-527508 DO - https://doi.org/10.3390/toxins13050342 VL - 13 IS - 5 SP - 342 PB - MDPI CY - Basel, Switzerland AN - OPUS4-52750 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Henkel, S. A1 - Weidner, A. A1 - Biermann, H. A1 - Kühn, Hans-Joachim A1 - Rehmer, Birgit A1 - Sonntag, Nadja T1 - LCF behavior and microstructure of alpha-brass CuZn30 under uniaxial, planar-biaxial and tension-torsion loading conditions N2 - The low-cycle fatigue behavior of cc-brass CuZn30 was irtvestigated in uniaxial (tension-compression and torional) and biaxial tests under total strain control at room temperature. Planar-biaxial fatigue tests were carried out on a servohydraulic tension-compression testing machine with and without phase shift using a cruciform specimen geometry with fixed principal stress axes. In phase and out of phase tensiontorsion tests were performed using tube shape specimens on a servohydraulic tensiontorsion testing machine. Microstructural investigations were performed by transmission electron microscopy as well as by scanning electron microscope. For all proportional load cases the equivalent strain amplitude based on a maximum shear strain energy criterion results in a similar hardening behavior and in fatigue life times within a scatter band of three. Out of phase loading results in additional cyclic hardening and reduced life time. Planar glide structures were observed in all tested cases as well as areas of pronounced strain localization in the torsional load cases. No evidence of transition to wavy glide behavior was observed. T2 - ICMFF10 - 10. International conference Multiaxial fatigue and fracture CY - Kyoto, Japan DA - 03.06.2013 KW - Fatigue biaxial PY - 2013 SP - 1 EP - 8 AN - OPUS4-32877 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Loveday, M.S. A1 - Bicego, V. A1 - Hähner, P. A1 - Klingelhöffer, Hellmuth A1 - Kühn, Hans-Joachim A1 - Roebuck, B. T1 - Analysis of a European TMF inter-comparison exercise N2 - A major international inter-comparison exercise on strain-controlled thermo-mechanical fatigue (TMF) has been undertaken to validate a new European Code of Practice for TMF Testing and to provide underpinning information for an ISO Standard. This paper focuses on (a) distribution of samples of Nimonic 90, (b) the establishment of a protocol for testing and reporting results, and (c) the analysis of the results. Participants in the inter-comparison exercise comprised eight inner-circle partners who primarily used test pieces which were all manufactured at the same workshop, albeit of three different test piece geometries, and ten outer-circle participants who manufactured their own test pieces, of their own in-house geometry. Each participant undertook three repeat in-phase (IP) tests and three repeat out-of-phase (OP) tests. The tests were conducted at temperatures cycling between 400 °C and 850 °C, with a strain range selected to give a failure life of approximately 1000 cycles, resulting in a stress range of up to ~1000 MPa. The testing conditions were chosen following a preliminary evaluation of critical testing parameters. Results from solid circular and solid flat test piece geometries, together with hollow tubular test pieces have been compared. The influence of temperature measurement using different types of temperature sensors has also been investigated. In-house repeatability has been assessed, together with inter-laboratory reproducibility. The results have been correlated with modulus and thermal expansion data for individual tests. Initially, the largest contribution to scatter in the results was attributed to human errors in reporting the results, compounded by computer assisted ‘cut-and-paste’ errors. Once these obvious discrepancies had been corrected, it was possible to use the data sets to point to some recommendations regarding testing procedures that can be incorporated into the Code of Testing Practice [Hähner P et al. Code of practice for thermo-mechanical fatigue testing – TMF-Standard-Work Package 6 Report, September 2005] and provide technical underpinning for the ISO Standard. The results and the procedures used for analysis are presented. KW - Thermomechanical KW - Fatigue KW - Test methods KW - Analysis KW - Nickel-base superalloys PY - 2008 DO - https://doi.org/10.1016/j.ijfatigue.2007.01.059 SN - 0142-1123 VL - 30 IS - 2 SP - 382 EP - 390 PB - Elsevier CY - Oxford AN - OPUS4-17535 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -