TY - CONF A1 - Kotschate, Daniel A1 - Gohlke, Dirk A1 - Dobrovolskij, P. A1 - Vrana, J. A1 - Heckel, Thomas T1 - Herausforderungen bei der Prüfung von Schmiedeteilen durch Vorsatzkeile für Longitudinalwellenprüfköpfe N2 - Trotz moderner Sensortechnologien und Rekonstruktionsmethoden, findet die manuelle und automatisierte Ultraschallprüfung durch konventionelle Senkrecht- und Winkelprüfköpfe vielfach industriellen Einsatz. Um einen flexiblen Prüfeinsatz und die Prüfbarkeit von einfachen sowie komplexen Geometrien zu gewährleisten, werden dort oftmals Vorlaufkeile für die Winkelprüfung mit Longitudinalwellen angewendet um eine Anzeigenschräglage und deren Reflektivität auszugleichen bzw. zu verbessern. Durch den unterschiedlichen Aufbau, im Vergleich zu integrierten Scherwellen-Winkelprüfköpfen, können jedoch während der Prüfung Fehlanzeigen generiert werden. Diese fehlerhaften Anzeigen beruhen auf Mehrfachreflexionen und Wellenumwandlungen innerhalb des Vorlaufkeils, aufgrund der Geometrie und können im Feld nur bedingt von realen Anzeigen unterschieden werden. Dieser Beitrag zeigt die geometrische Betrachtung bei der Verwendung von Vorlaufkeilen und wurde experimentell durch die Bestimmung der Richtcharakteristik und dem Einsatz von elektrodynamischen Sonden validiert. Des Weiteren ermöglichen die so gewonnenen Abhängigkeiten einen vom Keilwinkel abhängigen Verstärkungsausgleich und somit eine korrekte Größenbestimmung durch einen geeigneten Vergleichsfehler. T2 - DACH-Jahrestagung 2019 CY - Friedrichshafen, Germany DA - 27.05.2019 KW - Richtcharakteristik KW - Vorlaufkeile KW - Mehrfachreflexion PY - 2019 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-480999 VL - 2019 SP - 1 EP - 7 PB - DGZfP Deutsche Gesellschaft für Zerstörungsfreie Prüfung AN - OPUS4-48099 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Schaepe, Kaija A1 - Jungnickel, H. A1 - Heinrich, Thomas A1 - Tentschert, J. A1 - Luch, A. A1 - Unger, Wolfgang ED - Hodoroaba, Vasile-Dan ED - Unger, Wolfgang ED - Shard, A. G. T1 - Secondary ion mass spectrometry N2 - This chapter provides an introduction in secondary ion mass spectrometry as one of the leading surface chemical analysis and imaging techniques with molecular specificity in the field of material sciences. The physical basics of the technique are explained along with a description of the typical instrumental setups and their modes of operation. The application paragraph specifically focuses on nanoparticle analysis by SIMS in terms of surface spectrometry, imaging, analysis in organic and complex media, and depth profiling. A review of the existing literature is provided, and selected studies are showcased. Limitations and pitfalls as well as current technical developments of SIMS application in nanoparticle surface chemical analysis are equally discussed. KW - Time-of-flight secondary ion mass spectrometry KW - Surface chemical analysis KW - Imaging KW - Nanomaterials KW - Nanoparticles KW - Core-shell PY - 2020 SN - 978-0-12-814182-3 DO - https://doi.org/10.1016/B978-0-12-814182-3.00025-0 SP - 481 EP - 509 PB - Elsevier CY - Amsterdam AN - OPUS4-50187 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Perez, Jeffey Paulo H. A1 - Tobler, Dominique J. A1 - Thomas, Andrew N. A1 - Freeman, Helen M. A1 - Dideriksen, Knud A1 - Radnik, Jörg A1 - Benning, Liane G. T1 - Adsorption and reduction of arsenate during the Fe2+-induced transformation of ferrihydrite N2 - Iron (oxyhydr)oxides play an important role in controlling the mobility and toxicity of arsenic (As) in contaminated soils and groundwaters. However, dynamic subsurface geochemical conditions can potentially impact As sequestration since this is highly dependent on the dominant iron mineral phases present and the pathways through which they form. In this study, we investigated the Fe2+-induced transformation of As(V)-bearing ferrihydrite (As-FH) to more crystalline phases under relevant anoxic subsurface conditions. Specifically, we examined the influence of varying Fe2+(aq)/Fe(III)solid¬ ratios on the behavior and speciation of the mineral-bound As species during the mineralogical transformation of As-FH at pH 6.5 for 24 h. At lower Fe2+(aq)/Fe(III)solid¬ ratios (0.5 to 1), goethite, green rust sulfate (GR¬SO4) and lepidocrocite formed within the first 2 hours of the reaction, but only goethite and some unreacted FH remained after 24 h. At Fe2+(aq)/Fe(III)solid¬ ratio = 2, GRSO4 remained stable throughout the 24 h reaction, alongside goethite and unreacted FH. Despite >82% of the As-FH being transformed to goethite  GRSO4 in these reactions, no significant As release (>99.9% removal) was observed. However, while As remained mineral-bound, partial oxidation of the initially added As(V) was reduced to As(III), most likely, by the goethite-Fe2+(aq) redox couple. The extent of As(V) reduction increased from ~40% to ~50%, as the Fe2+(aq)/Fe(III)solid¬ ratio increased from 0.5 to 2. Overall, these results provide important insights into transformation pathways of iron (oxyhydr)oxide minerals in As contaminated, anoxic soils and sediments, and also demonstrate the great impact these can have on As oxidation state and, hence, toxicity and mobility in these environments. KW - Ferrihydrite KW - Mineral tranformation KW - XPS KW - Green rust KW - Goethite KW - XAS PY - 2019 DO - https://doi.org/10.1021/acsearthspacechem.9b00031 SN - 2472-3452 VL - 3 IS - 6 SP - 884 EP - 894 PB - ACS AN - OPUS4-48436 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Yadav, Anur A1 - Iost, R. M. A1 - Neubert, T. J. A1 - Baylan, S. A1 - Schmid, Thomas A1 - Balasubramanian, Kannan T1 - Selective electrochemical functionalization of the graphene edge N2 - We present a versatile and simple method using electrochemistry for the exclusive functionalization of the edge of a graphene monolayer with metal nanoparticles or polymeric amino groups. The attachment of metal nanoparticles allows us to exploit surface-enhanced Raman scattering to characterize the chemistry of both the pristine and the functionalized graphene edge. For the pristine patterned graphene edge, we observe the typical edge-related modes, while for the functionalized graphene edge we identify the chemical structure of the functional layer by vibrational fingerprinting. The ability to obtain single selectively functionalized graphene edges routinely on an insulating substrate opens an avenue for exploring the effect of edge chemistry on graphene properties systematically. KW - Graphene KW - Nanoparticles KW - Nanosciences KW - Surface-enhanced Raman scattering KW - Atomic force microscopy PY - 2019 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-474357 DO - https://doi.org/10.1039/C8SC04083D SN - 2041-6520 VL - 10 IS - 3 SP - 936 EP - 942 PB - Royal Society of Chemistry AN - OPUS4-47435 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Sprengel, Maximilian A1 - Ulbricht, Alexander A1 - Evans, Alexander A1 - Kromm, Arne A1 - Sommer, Konstantin A1 - Werner, Tiago A1 - Kelleher, J. A1 - Bruno, Giovanni A1 - Kannengießer, Thomas T1 - Towards the optimization of post-laser powder bed fusion stress-relieve treatments of stainless steel 316L N2 - This study reports on the stress relaxation potential of stress-relieving heat treatments for laser powder bed fused 316L. The residual stress is monitored non-destructively using neutron diffraction before and after the heat treatment. Moreover, the evolution of the microstructure is analysed using scanning electron microscopy. The results show, that a strong relaxation of the residual stress is obtained when applying a heat treatment temperature at 900°C. However, the loss of the cellular substructure needs to be considered when applying this heat treatment strategy. KW - Residual stress KW - Additive manufacturing KW - Neutron diffraction KW - Projekt AGIL - Alterung additiv gefertigter metallischer Materialien und Komponenten PY - 2021 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-536045 DO - https://doi.org/10.1007/s11661-021-06472-6 SN - 1543-1940 VL - 52 IS - 12 SP - 5342 EP - 5356 PB - Springer CY - Boston AN - OPUS4-53604 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Rades, Steffi A1 - Borghetti, P. A1 - Ortel, Erik A1 - Wirth, Thomas A1 - Blanco, M. A1 - Gómez, E. A1 - Martinez, A. A1 - Jupille, J. A1 - Martra, G. A1 - Hodoroaba, Vasile-Dan T1 - Control of functionalization of supports for subsequent assembly of titania nanoparticle films N2 - For self‐assembling of TiO2 nanoparticles in multiple layers by layer‐by‐layer deposition to be applied to TiO2 thin films with defined and homogeneous thickness for large‐scale applications, the proper functionalization of substrate surface is a prerequisite to guarantee sufficient adhesion. The substrates selected and tested in the present paper were conductive, fluorine‐doped tin oxide (FTO) glass, nonconductive silica glass, and titanium alloy. The current study focusses on the analytical control of the stepwise functionalization of the substrates with 3‐aminopropyltriethoxysilane and glutaraldehyde (GA) for both the FTO glass and silica glass and with 3‐aminepropyl phosphonic acid and GA for Ti alloy. The analyses have been conducted by means of surface sensitive methods, X‐ray photoelectron spectroscopy, Auger electron spectroscopy, and time‐of‐flight secondary ions mass spectrometry. Chemical composition of surface of functionalized substrates shows differences in the degree and type of modification in dependence on substrate. It could be demonstrated that the best functionalized substrates were the conductive FTO glasses. The analysis of the functionalized Ti substrates has revealed that the surface coverage with 3‐aminepropyl phosphonic acid and GA molecules is an inhomogeneous one, and further optimization of the two‐step functionalization on the Ti alloy substrate is necessary. KW - Nanoparticles KW - Surface functionalization KW - TiO2 KW - SEM/EDX KW - Auger Electron Spectroscopy KW - ToF-SIMS KW - Thin films PY - 2018 DO - https://doi.org/10.1002/sia.6398 SN - 0142-2421 SN - 1096-9918 VL - 50 IS - 11 SP - 1200 EP - 1206 PB - John Wiley & Sons, Ltd. AN - OPUS4-46406 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Schäfer, N. A1 - Chahine, G. A. A1 - Wilkinson, A. J. A1 - Schmid, Thomas A1 - Rissom, T. A1 - Schülli, T. U. A1 - Abou-Ras, D. T1 - Microstrain distributions in polycrystalline thin films measured by X-ray microdiffraction N2 - Microstrain distributions were acquired in functional thin films by high-resolution X-ray microdiffraction measurements, using polycrystalline CuInSe2 thin films as a model system. This technique not only provides spatial resolutions at the submicrometre scale but also allows for analysis of thin films buried within a complete solar-cell stack. The microstrain values within individual CuInSe2 grains were determined to be of the order of 10^-4. These values confirmed corresponding microstrain distribution maps obtained on the same CuInSe2 layer by electron backscatter diffraction and Raman microspectroscopy. KW - Microstrain distribution KW - X-ray microdiffraction KW - Polycrystalline thin films KW - Raman microscopy PY - 2016 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-366592 DO - https://doi.org/10.1107/S1600576716003204 SN - 1600-5767 VL - 49 SP - 632 EP - 635 AN - OPUS4-36659 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Müller, Christina A1 - Bertovic, Marija A1 - Holstein, R. A1 - Kanzler, Daniel A1 - Pitkänen, J. A1 - Ronneteg, U. A1 - Heckel, Thomas T1 - A plenary view on the vigour of our NDE reliability models N2 - Using the Modular Reliability Model the three different main influencing elements, i.e. intrinsic capability (IC), application parameters (AP) and the human factors (HF), are, in the first instance, investigated separately. The intrinsic capability stands for the pure physical-technological process of the signal detection caused by the waves or the rays from a material defect in the presence of noise (driven by the material and the devices). This intrinsic capability is the upper bound of the possible reliability. Already when measuring this intrinsic capability for thick walled components the original one-parameter POD must be extended to a multiparameter POD, where, in addition to the defect size, a number of additional physical parameters, such as the grain size distribution (or attenuation), defect depth, and angle or surface roughness, must be considered. For real life cycle assessments it is necessary to evaluate the signal response from real defects. The industrial application factors, e.g. coupling conditions, limited accessibility, heat and environmental vibrations, diminish the reliability. The amount of reduction can be determined quantitatively, if the underlying conditions are controlled. In case they are not controlled it is necessary to count for a fluctuation in the reliability in the field anyway. The third group of important influencing factors are the human factors, which do not only cover the individual performance capability of the inspectors but also the design of the working place,the procedure, the teamwork quality, interaction with systems, the organization, and finally, the relationship between the companies involved in the inspection process and to which extend the responsible parties are aware of it. When comparing an “ideal inspection” with a “real inspection” it is worth while to look how the existing practices, rules and standards support reliable testing and where the “delta” is. In the context of vigor, with respect to the industrial end user, it needs to be shown how the level of reliability of NDE, influenced by the different factors, has an impact on acceptance or rejection of safety critical parts. T2 - 5th European-American workshop on reliability of NDE CY - Berlin, Germany DA - 07.10.2013 PY - 2013 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-312658 SN - 978-3-940283-53-5 IS - DGZfP-BB 144 SP - Lecture 2, 1 EP - 18 PB - Deutsche Gesellschaft für Zerstörungsfreie Prüfung (DGZfP) CY - Berlin AN - OPUS4-31265 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Taffe, Alexander A1 - Kind, Thomas A1 - Stoppel, Markus A1 - Kurz, J. H. T1 - OSSCAR-Bauwerkscanner: Automatisierte Datenaufnahme von Radar, Ultraschall und Wirbelstrom an Spannbetonbauteilen mit bildgebender Darstellung der inneren Konstruktion N2 - Bereits seit vielen Jahren stehen Anwendern der zerstörungsfreien Prüfung im Bauwesen (ZfPBau) zuverlässige Geräte für Radar-, Wirbelstrom- und Ultraschallmessungen an Betonbauteilen zur Verfügung. Doch erst die Kombination dieser drei Verfahren an einer Messfläche erlaubt den maximalen Informationsgewinn über die innere Konstruktion von Stahlbeton- und Spannbetonbauteilen. Mit dem OSSCAR-Bauwerkscanner wurden diese drei Verfahren erstmals zur kombinierten und automatisierten Datenaufnahme an einem Scannerrahmen und unter einer Software vereint. Die Ergebnisse werden bildgebend in frei wählbaren Schnitten dargestellt, was eine Rekonstruktion von Bauteilen erlaubt, für die keine Planunterlagen vorliegen. T2 - DGZfP-Jahrestagung 2011 CY - Bremen, Germany DA - 30.05.2011 KW - Zerstörungsfreie Prüfung im Bauwesen KW - Bauwerkscanner KW - Brückenprüfung KW - Ultraschall KW - Radar KW - Wirbelstrom KW - Kombination PY - 2011 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-253767 SN - 978-3-940283-33-7 IS - DGZfP-BB 127 (Mi.3.B.1) SP - 1 EP - 8 PB - Deutsche Gesellschaft für Zerstörungsfreie Prüfung (DGZfP) AN - OPUS4-25376 LA - deu 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 - 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 - JOUR A1 - Hübert, Thomas A1 - Tiebe, Carlo A1 - Detjens, Marc A1 - Majewski, J. T1 - On-site calibration system for trace humidity sensors N2 - A portable device for calibration of trace humidity sensors and an adopted calibration procedure have been developed. The calibration device is based on humidity generation by permeating water through polymeric membrane tubes. Water vapour transmission rates for various polymers were experimentally determined in order to select the most suitable polymeric material. The developed trace humidity generator consists of a gas-flow polymeric hose immersed in a water reservoir thermostated by a sensorcontrolled heater. Mole fractions of water vapour between 1 µmol/ molˉ¹ and 350 µmol/molˉ¹ (equivalent to frost-point temperatures from -76 °C to -31 °C) were generated by varying either the operating temperature or gas flow. The operating temperature can be varied from 20 °C to 60 °C and kept stable within 0.1 K. Uncertainty analysis indicated that the trace humidity generator produces gas flows of constant humidity amounts with a relative expanded uncertainty less than 3.4% (k = 2) of the generated value. KW - Polymeric tubes KW - Measurements KW - Trace Humidity KW - Sensor calibration KW - Water vapour permeation PY - 2016 DO - https://doi.org/10.1016/j.measurement.2016.05.013 SN - 0263-2241 VL - 91 IS - 9 SP - 251 EP - 257 PB - Elsevier Ltd. AN - OPUS4-36762 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Holst, N. A1 - Khakpour, Thomas A1 - Holtappels, Kai A1 - Steinbach, J. T1 - Ignition behavior of methane-oxygen mixtures at elevated conditions N2 - Self-ignition behavior of mixtures of methane and oxygen was investigated in a temperature range from 600 to 800°C. Variations of mixture composition, inert gas content, temperature and filling rate of the ignition autoclave were carried out in order to establish process boundaries for high temperature partial oxidation processes. The tests show that considerably high methane contents are needed to avoid an ignition. Heating-up tests show that ignition is possible at surprisingly low temperatures. This can be attributed to pre-ignition reactions that produce more instable intermediates. T2 - 2011 AIChE Spring meeting & 7th global congress on process safety CY - Chicago, IL, USA DA - 13.03.2011 KW - Safety KW - Explosion KW - Self-ignition KW - Methane KW - Partial oxidation PY - 2011 SN - 978-0-8169-1067-10 IS - Topical 1 / #13 / 13h SP - 1 EP - 10 CY - New York, NY, USA AN - OPUS4-23626 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Scharf-Wildenhain, R. A1 - Engelking, Lorenz A1 - Hälsig, A. A1 - Schröpfer, Dirk A1 - Kannengießer, Thomas A1 - Hensel, J. T1 - Influence of build‑up height on residual stresses in additive repair and modification using DED‑Arc with high‑strength filler metals N2 - Directed energy deposition (DED)-Arc is suitable for the hybrid additive manufacturing, modification and repair of large metal components with high deposition rates. Residual stresses and distortion are of central importance when characterizing the manufactured components and the sensitive transition area between additive manufactured (AM) component and semifinished product. Residual stresses caused by the thermal cycles during the manufacturing process can impair the mechanical properties of the manufactured parts and can lead to component failure, especially for high-strength steels. Therefore, understanding and controlling residual stresses, when combining different base and feedstock materials, is critical to improve the quality and efficiency of the hybrid DED-Arc process. This article deals with the influence of the build-up height on the residual stress distribution of additively manufactured components with a selected base and feedstock material from commercial high-strength steels. Using a robot-assisted DED-system and a controlled short arc, AM welding experiments were carried out with close to the application parameters at working temperature (200 °C) and heat input (650 kJ/m). Five hybrid AM specimens (AM wall on upright structural steel plate) were produced using a one bead per layer strategy and selected AM-wall heights between 15 and 300 mm. The influence of the AM build height on the longitudinal residual stress in the whole hybrid AM specimen (in welding direction) was analyzed and discussed. All experiments exhibit comparable stress distributions in the area of the substrate plate up to the heat-affected zone (HAZ) and the transition zone, regardless of the building height. The height significantly influences the residual stress distribution of the deposited AM-component. Tensile residual stresses with a maximum range between 300and 400 MPa were always found in the last approx. 18 component layers (upper 40 mm). This is due to restraint of the shrinking of the top layers by the layers below. The lower layers show homogeneous residual stress distributions characterized by low compressive stresses due to the process-related tempering during the deposition of each layer on top of each other. As a result, the significant difference between the various AM build-up heights of the hybrid AM specimens is the extent (or height) of this tempered zone with low compressive stresses. These correlations contribute to the understanding of residual stress development with increasing structure height or ratio of component heights of substrate semi-finished product and AM component in hybrid additive manufacturing. T2 - 78th IIW Annual Assembly and International Conference CY - Genoa, Italy DA - 22.06.2025 KW - DED-Arc KW - Residual stress KW - Heat control PY - 2026 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-656793 DO - https://doi.org/10.1007/s40194-026-02417-y SN - 1878-6669 SP - 1 EP - 12 PB - Spriner AN - OPUS4-65679 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Diersch, Norman A1 - Kind, Thomas A1 - Taffe, Alexander A1 - Kurz, J.H. T1 - Untersuchung vorgespannter Brückenplatten unter Verkehr mit zerstörungsfreien Prüfverfahren N2 - Der Untersuchung von vorgespannten Brückenplatten bzw. Fahrbahnplatten kommt angesichts ihrer direkten Belastung durch Verkehr und der Gefahr durch Tausalzeintrag infolge von Schäden an der Abdichtung eine tragende Rolle bei der Planung von Instandsetzungsarbeiten zu. Da diese Bauteile direkt befahren werden, ist der Einsatz zerstörungsfreier Prüfverfahren (ZfPBau-Verfahren) sinnvoll, wobei deren Anwendung nur einen begrenzten Eingriff in den Verkehr verursachen sollte. In diesem Beitrag werden neben dem großflächigen Einsatz von Radar von der Brückenoberseite aus, d. h. durch den Fahrbahnbelag hindurch, Detailuntersuchungen von der Brückenunterseite mithilfe von Bauwerkscannern beschrieben. Diese Scanner verwenden sowohl Radar als auch Ultraschall mit ihren komplementären Verfahrenseigenschaften, wobei deren Möglichkeiten und Grenzen aufgezeigt werden. Abschließend wird eine Strategie zur Kombination von ZfPBau-Verfahren sowie deren gezielter großflächiger Einsatz in Abgrenzung zu kleinflächigen Detailuntersuchungen beschrieben. N2 - The investigations of pre-stressed bridge decks and carriageway slabs, considering their direct exposure to traffic and threat of ingress of de-icing salt as a result of damage of the seal, plays a major role in the planning of repair work. Since these building elements are driven directly, the usage of non-destructive testing (NDT methods) is useful where the application should cause only a limited intervention into traffic. In this paper, in addition to the large-scale measurements with radar from the outer side of the bridge, which is through the road surface, detailed studies of the bridge base with the help of on-site scanners are described. These scanners use radar and ultrasonic with their complementary properties. The possibilities and limitations are discussed here. Finally, a strategy for combining NDT methods and their specific large-scale applications in a distinction to small-scale detailed studies is described. KW - Bauwerksüberwachung KW - Brücken KW - Messsysteme KW - Praxis KW - Lebensdauer KW - OSSCAR KW - Radar KW - Ultraschall KW - Korrosion KW - Brückenbau KW - Bauwerkserhaltung/Sanierung PY - 2014 DO - https://doi.org/10.1002/best.201400010 SN - 0005-9900 SN - 1437-1006 VL - 109 IS - 7 SP - 444 EP - 452 PB - Ernst & Sohn CY - Berlin AN - OPUS4-33016 LA - deu 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 - JOUR A1 - Debatin, F. A1 - Thomas, A. A1 - Kelling, A. A1 - Hedin, N. A1 - Bacsik, Z. A1 - Senkovska, I. A1 - Kaskel, S. A1 - Junginger, M. A1 - Müller, H. A1 - Schilde, U. A1 - Jäger, Christian A1 - Friedrich, A. A1 - Holdt, H.-J. T1 - In situ synthesis of an imidazolate-4-amide-5-imidate ligand and formation of a microporous zinc-organic framework with H2-and CO2-storage ability KW - Metal-organic framework KW - Synthesis KW - XRD KW - FTIR KW - NMR KW - Gas sorption KW - Microporous materials KW - N,O ligands KW - Solvothermal synthesis PY - 2010 DO - https://doi.org/10.1002/anie.200906188 SN - 1433-7851 SN - 1521-3773 SN - 0570-0833 VL - 49 IS - 7 SP - 1258 EP - 1262 PB - Wiley-VCH CY - Weinheim AN - OPUS4-21132 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Taffe, Alexander A1 - Kind, Thomas A1 - Stoppel, Markus A1 - Kurz, J.H. ED - Gieler-Breßmer, S. T1 - Zuverlässige Bewehrungsortung: Vom klassischen Handgerät zum automatisierten Bauwerkscanner T2 - 8. Symposium "Kathodischer Korrosionsschutz von Stahlbetonbauwerken" CY - Ostfildern, Deutschland DA - 2010-11-18 KW - Zerstörungsfreie Prüfung im Bauwesen KW - Kathodischer Korrsoionsschutz KW - Ortung von Bewehrung KW - Wirbelstrom KW - Radar KW - Ultraschallecho PY - 2010 SN - 3-924813-88-4 SP - 21 EP - 33 AN - OPUS4-22547 LA - deu 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 - JOUR A1 - Seah, M.P. A1 - Unger, Wolfgang A1 - Wang, H. A1 - Jordaan, W. A1 - Gross, Thomas A1 - Dura, J.A. A1 - Moon, D.W. A1 - Totarong, P. A1 - Krumrey, M. A1 - Hauert, R. A1 - Zhiqiang, M. T1 - Ultra-thin SiO2 on Si IX: absolute measurements of the amount of silicon oxide as a thickness of SiO2 on Si N2 - Results from a study conducted between National Metrology Institutes (NMIs) for the measurements of the absolute thicknesses of ultra-thin layers of SiO2 on Si are reported. These results are from a key comparison and associated pilot study under the auspices of the Consultative Committee for Amount of Substance. ´Amount of substance´ may be expressed in many ways, and here the measurand is the thickness of the silicon oxide layers with nominal thicknesses in the range 1.5-8 nm on Si substrates, expressed as the thickness of SiO2. Separate samples were provided to each institute in containers that limited the carbonaceous contamination to approximately < 0.3 nm. The SiO2 samples were of ultra-thin on (100) and (111) orientated wafers of Si. The measurements from the laboratories which participated in the study were conducted using ellipsometry, neutron reflectivity, X-ray photoelectron spectroscopy or X-ray reflectivity, guided by the protocol developed in an earlier pilot study. A very minor correction was made in the different samples that each laboratory received. Where appropriate, method offset values attributed to the effects of contaminations, from the earlier pilot study, were subtracted. Values for the key comparison reference values (agreed best values from a Consultative Committee study) and their associated uncertainties for these samples are then made from the weighted means and the expanded weighted standard deviations of the means of these data. These results show a dramatic improvement on previous comparisons, leading to 95% uncertainties in the range 0.09-0.27 nm, equivalent to 0.4-1.0 monolayers over the 1.5-8.0 nm nominal thickness range studied. If the sample-to-sample uncertainty is reduced from its maximum estimate to the most likely value, these uncertainties reduce to 0.05-0.25 nm or ~1.4% relative standard uncertainties. The best results achieve ~1% relative standard uncertainty. It is concluded that XPS has now been made fully traceable to the SI, for ultra-thin thermal SiO2 on Si layers, by calibration using wavelength methods in an approach that may be extended to other material systems. KW - Attenuation length KW - Calibration KW - Silicon dioxide KW - Thickness KW - Ultra-thin oxide PY - 2009 DO - https://doi.org/10.1002/sia.3045 SN - 0142-2421 SN - 1096-9918 VL - 41 IS - 5 SP - 430 EP - 439 PB - Wiley CY - Chichester AN - OPUS4-19246 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Taffe, Alexander A1 - Kind, Thomas A1 - Stoppel, Markus A1 - Kurz, J.H. T1 - Bauwerkscanner zur automatisierten und kombinierten Anwendung zerstörungsfreier Prüfverfahren im Bauwesen N2 - Bereits seit vielen Jahren stehen Anwendern der zerstörungsfreien Prüfung im Bauwesen (ZfPBau) zuverlässige Geräte zur Untersuchung von Betonbauteilen zur Verfügung. Viele dieser Geräte zeichnen eine Messgröße in Bezug zum Messort auf und sind je nach Ausstattung in der Lage, die Ergebnisse in einem Koordinatensystem darzustellen. Doch erst die Kombination verschiedener ZfPBau-Verfahren an einer Messfläche erlaubt den maximalen Informationsgewinn über die innere Konstruktion von Stahlbeton- und Spannbetonbauteilen. In dem Beitrag wird ein Bauwerkscanner zur automatisierten und kombinierten Datenaufnahme beschrieben, der erstmals die Kombination von Radar, Ultraschall und Wirbelstrom mit Datenausgabe in einem einheitlichen Koordinatensystem ermöglicht. Dieser Scanner ist im Gegensatz zu früheren Systemen technikerbasiert und erlaubt im Bedarfsfall eine spätere detaillierte Auswertung durch ZfP-Spezialisten. Die Ergebnisse werden bildgebend in frei wählbaren Schnitten dargestellt, was bereits kurze Zeit nach der Messung auf der Baustelle möglich ist. Am Beispiel eines Brückenträgers wird gezeigt, wie der tatsächliche Spanngliedverlauf aus Messdaten ermittelt wird und dem angenommenen Verlauf gemäß Bestandsplan gegenübergestellt wird. Damit kann künftig eine Überprüfung von Bestandsplänen durchgeführt werden. Darüber hinaus könnten nicht vorhandene Bestandspläne rekonstruiert werden. Des Weiteren wird am gleichen Brückenträger gezeigt, wie sich ein echter Verpressfehler und im Unterschied dazu ein Luftspalt in einem Hüllrohr in Messdaten abbilden. An dem Beispiel wird deutlich, wie Ultraschallergebnisse in Kombination mit Phasenauswertung zur Formulierung von Verdachtsstellen für Verpressfehler eingesetzt werden können und welche Maßnahmen zur Verifizierung getroffen werden müssen. KW - Zerstörungsfreie Prüfung im Bauwesen KW - Bauen im Bestand KW - Brückenprüfung KW - Spanndrahtbruch KW - Remanenzmagnetismus KW - Automatisierung PY - 2011 DO - https://doi.org/10.1002/best.201100004 SN - 0005-9900 SN - 1437-1006 VL - 106 IS - 4 SP - 267 EP - 276 PB - Ernst CY - Berlin AN - OPUS4-23757 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Güttler, B. A1 - Schiel, D. A1 - Danzebrink, H. A1 - Unger, Wolfgang A1 - Gross, Thomas A1 - Lippitz, Andreas A1 - Müller, J.-P. T1 - Physical and Chemical Characterization of Thermal and Native Siliconoxide layers on Silicon T2 - Symposium "Reference Materials for Technologies in the New Millenium" CY - Berlin, BAM, Germany DA - 2000-05-22 PY - 2000 SP - 1(?) EP - 7(?) AN - OPUS4-6924 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - 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 - CONF A1 - Herrmann, Ralf A1 - Hille, Falk A1 - Said, Samir A1 - Sterthaus, Jens A1 - Müller, Karsten A1 - Quercetti, Thomas A1 - Wille, Frank A1 - Paffenholz, J.-A. A1 - Baeßler, Matthias ED - Papadrakakis, M. ED - Fragiadakis, M. ED - Papadimitriou, C. T1 - Implementing a Structural Health Monitoring system using digital models of the BAM large drop test facility in Horstwalde N2 - At the Bundesanstalt für Materialforschung und -prüfung (BAM) full scale specimens for nuclear transport and storage containers (casks) are tested for their structural integrity in a series of drop tests on the Test Site Technical Safety in Horstwalde, 50 km south of Berlin. These drop tests cause a major stress not only on the casks, but also on the steel tower structure of the test facility, itself. The load pattern makes the structure very interesting for detailed investigation. The focus of the monitoring lies on the bolted joints of the flange connections that are a typical connection for cylindrical elements if welding is technical or economical unfavorable. The definition of the monitoring takes was done by investigating the existing documents and inspection results accompanied by building an initial digital representation of the structure, consisting of two finite element (FE) models and a geometrical 3D point cloud representation. As a first step the structures behavior during static and dynamic loading was analyzed using measurement data and an updated numerical FE Model. The idea behind is to use models for a digital planning and operation/evaluation of the structural health monitoring. A static FE simulation and a dynamic FE simulation are generated, to investigate how the structure behaves under the load conditions. T2 - XI International Conference on Structural Dynamics (EuroDyn 2020) CY - Online meeting DA - 23.11.2020 KW - Structural Health Monitoring KW - Drop Tests KW - System Identification KW - Digital Models KW - BIM PY - 2020 UR - https://generalconferencefiles.s3-eu-west-1.amazonaws.com/eurodyn_2020_ebook_procedings_vol1.pdf SN - 978-618-85072-0-3 VL - 1 SP - 1293 EP - 1304 PB - Institute of Structural Analysis and Antiseismic Research CY - Athen AN - OPUS4-51592 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Witke, Klaus A1 - Klaffke, Dieter A1 - Schneider, Thomas A1 - Schreckenbach, J.P. T1 - Laser-damaging as a useful tool for materials characterization by Raman microscopy KW - Raman-Mikroskopie KW - Raman-Laser KW - Laserstrahlbearbeitung PY - 1999 SN - 0169-4332 SN - 1873-5584 VL - 151 IS - 1-2 SP - 33 EP - 39 PB - North-Holland CY - Amsterdam AN - OPUS4-709 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Schneider, Ralf A1 - Weigert, Florian A1 - Lesnyak, V. A1 - Leubner, S. A1 - Lorenz, T. A1 - Behnke, Thomas A1 - Dubavik, A. A1 - Joswig, J.-O. A1 - Resch-Genger, Ute A1 - Gaponik, N. A1 - Eychmüller, A. ED - Resch-Genger, Ute ED - Schneider, Ralf T1 - pH and concentration dependence of the optical properties of thiol-capped CdTe nanocrystals in water and D2O N2 - The optical properties of semiconductor nanocrystals (SC NCs) are largely controlled by their size and surface chemistry, i.e., the chemical composition and thickness of inorganic passivation shells and the chemical nature and number of surface ligands as well as the strength of their bonds to surface atoms. The latter is particularly important for CdTe NCs, which – together with alloyed CdₓHg₁₋ₓTe – are the only SC NCs that can be prepared in water in high quality without the need for an additional inorganic passivation shell. Aiming at a better understanding of the role of stabilizing ligands for the control of the application-relevant fluorescence features of SC NCs, we assessed the influence of two of the most commonly used monodentate thiol ligands, thioglycolic acid (TGA) and mercaptopropionic acid (MPA), on the colloidal stability, photoluminescence (PL) quantum yield (QY), and PL decay behavior of a set of CdTe NC colloids. As an indirect measure for the strength of the coordinative bond of the ligands to SC NC surface atoms, the influence of the pH (pD) and the concentration on the PL properties of these colloids was examined in water and D₂O and compared to the results from previous dilution studies with a set of thiol-capped Cd₁₋ₓHgₓTe SC NCs in D₂O. As a prerequisite for these studies, the number of surface ligands was determined photometrically at different steps of purification after SC NC synthesis with Ellman’s test. Our results demonstrate ligand control of the pH-dependent PL of these SC NCs, with MPA-stabilized CdTe NCs being less prone to luminescence quenching than TGA-capped ones. For both types of CdTe colloids, ligand desorption is more pronounced in H₂O compared to D₂O, underlining also the role of hydrogen bonding and solvent molecules. KW - Quantum dots KW - Fluorescence KW - Ligand analysis KW - Nano particles PY - 2016 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-371253 DO - https://doi.org/10.1039/c6cp03123d VL - 18 IS - 28 SP - 19083 EP - 19092 PB - RSC CY - Cambridge AN - OPUS4-37125 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Sichler, Theresa Constanze A1 - Adam, Christian A1 - Barjenbruch, M. A1 - Montag, D. A1 - Mauch, Tatjana A1 - Sommerfeld, Thomas A1 - Ehm, J.H. T1 - Variation of the element composition of municipal sewage sludges in the context of new regulations on phosphorus recovery in Germany N2 - Phosphorus (P) recovery is obligatory for all sewage sludges with more than 20 g P/kg dry matter (DM) from 2029 in Germany. Nine wastewater treatment plants (WWTPs) were chosen to investigate variations of phosphorus contents and other parameters in sewage sludge over the year. Monthly sewage sludge samples from each WWTP were analyzed for phosphorus and other matrix elements (C, N, H, Ca, Fe, Al, etc.), for several trace elements (As, Cr, Mo, Ni, Pb, Sn) and loss of ignition. Among the nine WWTPs, there are four which have phosphorus contents both above and below the recovery limit of 20 g/kg DM along the year. Considering the average phosphorus content over the year, only one of them is below the limit. Compared to other matrix elements and parameters, phosphorus fuctuations are low with an average of 7% over all nine WWTPs. In total, only hydrogen and carbon are more constant in the sludge. In several WWTPs with chemical phosphorus elimination, phosphorus fuctuations showed similar courses like iron and/or aluminum. WWTPs with chamber flter presses rather showed dilution efects of calcium dosage. As result of this study, monthly phosphorus measurement is highly recommended to determine whether a WWTP is below the 20 g/kg DM limit. KW - Sewage sludge KW - Phosphorus recovery KW - Wastewater KW - Phosphorus elimination PY - 2022 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-557499 DO - https://doi.org/10.1186/s12302-022-00658-4 SN - 2190-4707 VL - 34 IS - 1 SP - 1 EP - 12 PB - Springer Nature CY - Berlin AN - OPUS4-55749 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 - Hodoroaba, Vasile-Dan A1 - Wirth, Thomas A1 - Terborg, R. A1 - Kim, K.J. A1 - Unger, Wolfgang T1 - Measurement of atomic fractions in Cu(In,Ga)Se2 films by Auger Electron Spectroscopy (AES) and Energy Dispersive Electron Probe Microanalysis (ED-EPMA) N2 - A pilot study (PS) has been performed under the Consultative Committee for Amount of Substance (CCQM) / Surface Analysis Working Group (SAWG) with the objective to compare the atomic fractions of Cu, In, Ga and Se in CIGS alloy films. Four polycrystalline CIGS films with different atomic fractions were fabricated by variation of the relative atomic fraction of Ga on 100 mm x 100 mm soda-lime glass (SLG) substrates. Similar to real solar cells the atomic fractions of the four elements (Cu, In, Ga, Se) are not homogeneous with depth. For the analysis of the CIGS layers of about 2 μm thickness depth profiling with surface analysis techniques such as XPS, AES and SIMS was recommended. A CIGS alloy reference sample with atomic fractions certified by isotope dilution ICP-MS at KRISS has been also put at disposal by the coordinator of the comparison. The certified values were close to the atomic fractions of the samples to be analyzed. Hence, the atomic fractions of Cu, In, Ga and Se in the CIGS films could be determined by the relative sensitivity factors (RSF) derived from the reference CIGS film. The total ion intensities of the constituent elements were obtained by the total number counting (TNC) method. KW - Interlaboratory comparison KW - Auger Electron Spectroscopy (AES) KW - EDX KW - EPMA KW - CIGS KW - CCQM PY - 2014 DO - https://doi.org/10.1017/S1431927614003730 SN - 1431-9276 SN - 1435-8115 VL - 20 IS - Suppl. S 3 SP - 402 EP - 403 PB - Cambridge University Press CY - New York, NY AN - OPUS4-31339 LA - eng 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 - Böllinghaus, 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 - CONF A1 - Kind, Thomas A1 - Kurz, J.H. A1 - Taffe, Alexander A1 - Wöstmann, Jens T1 - Ortung und Unterscheidung von Querspanngliedern hinter schlaffer Bewehrung mit dem Radarverfahren in einer Fahrbahnplatte N2 - Anhand eines erfolgreichen Messeinsatzes an einer Spannbetonbrücke, deren Querspannglieder zuverlässig lokalisiert und nachfolgend instandgesetzt werden sollen, wird die Vorgehensweise der Radarmessung mit zwei verschiedenen Polarisationsrichtungen der Antenne zur Unterscheidung von unterschiedlichen Arten der Bewehrungen ausführlich erklärt. Das Radarverfahren eignet sich sehr gut für die zerstörungsfreie Ortung von Bewehrung in Stahlbetonbauwerken. Insbesondere lässt sich mit dem Verfahren vorgespannte Bewehrung bis in einer Tiefe von ca. 30 cm und bei einem normalen Bewehrungsgrad (Maschenweite >10 cm) der schlaffen Bewehrung zuverlässig auffinden. Seit einigen Jahren wird das Radarverfahren erfolgreich im Vorfeld einer schadensfreien Kernbohrung im Rahmen von Ertüchtigungsmaßnahmen von Stahlbetonbrücken mit externen Spanngliedern angewendet. Aufgrund der Lage und dem Verlauf der vorgespannten Bewehrung in Hohlkastenseitenwänden und Plattenbalken kann eine vorgespannte Bewehrung von schlaffer Bewehrung in diesen Bauwerken sehr gut unterschieden werden. Diese Unterscheidungsmerkmale lassen sich aber bei Querspanngliedern in einer Fahrbahnplatte nur selten anwenden, da häufig die Überdeckung und der Abstand der schlaffen Bewehrung und der Querspannglieder ähnlich sind. In diesem Beitrag wird beschrieben, wie der gezielte Einsatz verschiedener Polarisationsrichtungen der Antenne zu einer zuverlässigen Unterscheidung von schlaffer Bewehrung und Spanngliedern beiträgt und damit zu einer verbesserten bildgebenden Darstellung der inneren Konstruktion der Fahrbahnplatte führt. T2 - DGZfP-Jahrestagung 2013 CY - Dresden, Germany DA - 06.05.2013 KW - Bauwesen KW - Zerstörungsfreie Prüfung PY - 2013 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-294454 SN - 978-3-940283-49-8 IS - DGZfP-BB 141 (Mi.1.B.3) SP - 1 EP - 9 PB - Deutsche Gesellschaft für zerstörungsfreie Prüfung e.V. (DGZfP) AN - OPUS4-29445 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Tuaev, X. A1 - Paraknowitsch, J.P. A1 - Illgen, René A1 - Thomas, A. A1 - Strasser, P. T1 - Nitrogen-doped coatings on carbon nanotubes and their stabilizing effect on Pt nanoparticles N2 - A homogeneous coating of nitrogen-doped carbon on carbon nanotubes is performed using ionic liquids. The N-doped material is employed as a support for nanoparticles. Electrochemical degradation behavior is monitored in situ and compared to an unmodified material. The strongly enhanced stability is explained on the basis of a Pt–nitrogen interaction. PY - 2012 DO - https://doi.org/10.1039/c2cp40760d SN - 1463-9076 SN - 1463-9084 VL - 14 IS - 18 SP - 6444 EP - 6447 PB - The Royal Soc. of Chemistry CY - Cambridge AN - OPUS4-25787 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -