TY - CONF A1 - Polomski, Benjamin A1 - Myrach, Philipp A1 - Le Claire, Elisabeth A1 - Unnikrishnakurup, Sreedhar A1 - Vengara, N. A1 - Balasubramaniam, Krishnan A1 - Ziegler, Mathias T1 - Thermographic crack detection in hot steel surface N2 - The detection and characterization of surface cracks in steel specimens prior to damage is a technologically and economically highly significant task and is of utmost importance when it comes to safety-relevant structures. In steel production where steel billets at high temperatures have to be inspected while moving a number of well-established NDT methods cannot be applied. Laser thermography however is a promising candidate to serve as a fast, non-contact and remote tool in this case. We present a study that shows that the crack detection capabilities of laser thermography can be extended also to specimens at high temperature. A combination of inductive and laser heating allows to systematically study the contrast formation as well as the optimization of the important measurement parameters. The experiments are accompanied by FEM simulations that provide a better insight of the physical correlations and support the experimental developments. The aim of these studies is to develop a system with high inspection speed and detection performance to be in-line operated under the hostile environment of steel production lines. T2 - 19th World Conference on Non-destructive Testing (WCNDT) CY - Munich, Germany DA - 13.06.2016 KW - Laser thermography KW - Non-destructive testing KW - Induction heating PY - 2016 AN - OPUS4-36813 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Thiel, Erik A1 - Kreutzbruck, M. A1 - Ziegler, Mathias T1 - Spatial and temporal control of thermal waves by using DMDs for interference based crack detection N2 - Active Thermography is a well-established non-destructive testing method and used to detect cracks, voids or material inhomogeneities. It is based on applying thermal energy to a samples’ surface whereas inner defects alter the nonstationary heat flow. Conventional excitation of a sample is hereby done spatially, either planar (e.g. using a lamp) or local (e.g. using a focused laser) and temporally, either pulsed or periodical. In this work we combine a high power laser with a Digital Micromirror Device (DMD) allowing us to merge all degrees of freedom to a spatially and temporally controlled heat source. This enables us to exploit the possibilities of coherent thermal wave shaping. Exciting periodically while controlling at the same time phase and amplitude of the illumination source induces – via Absorption at the sample’s surface - a defined thermal wave propagation through a sample. That means thermal waves can be controlled almost like acoustical or optical waves. However, in contrast to optical or acoustical waves, thermal waves are highly damped due to the diffusive character of the thermal heat flow and therefore limited in penetration depth in relation to the achievable resolution. Nevertheless, the coherence length of thermal waves can be chosen in the mmrange for modulation frequencies below 10 Hz which is perfectly met by DMD technology. This approach gives us the opportunity to transfer known technologies from wave shaping techniques to thermography methods. We will present experiments on spatial and temporal wave shaping, demonstrating interference based crack detection. T2 - Photonics West 2016, OPTO, 9761 CY - San Francisco, CA, USA DA - 15.02.2016 KW - Active thermography KW - Thermal wave KW - Spatial light modulation KW - Crack detection KW - DMD KW - DMD coupled laser PY - 2016 DO - https://doi.org/10.1117/12.2210918 SN - 0277-786X VL - 9761 SP - 97610N-1 EP - 97610N-13 AN - OPUS4-35587 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Thiel, Erik A1 - Kreutzbruck, M. A1 - Ziegler, Mathias T1 - Laser-projected photothermal thermography using thermal wave field interference for subsurface defect characterization N2 - The coherent superposition of two anti-phased thermal wave fields creates a zone of destructive interference which is extremely sensitive to the presence of defects without any reference measurements. Combining a high power laser with a spatial light modulator allows modulating phase and amplitude of an illuminated surface that induces spatially and temporally controlled thermal wave fields. The position and depth of defects are reconstructed from analysis of the Amplitude and Phase of the resulting photothermal signal. The proposed concept is experimentally validated and supported by numerical modeling. KW - Thermal waves KW - Active thermography KW - DMD KW - Spatial light modulator KW - Subsurface defects PY - 2016 UR - http://scitation.aip.org/search?value1=laser+projected+photothermal&option1=all&option912=resultCategory&value912=ResearchPublicationContent&operator8=AND&option8=pub_serialIdent&value8=aip%2Fjournal%2Fapl&qs=true DO - https://doi.org/10.1063/1.4963139 SN - 0003-6951 VL - 109 IS - 12 SP - 123504-1 EP - 123504-4 PB - AIP Publishing CY - Melville, New York AN - OPUS4-37590 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Jonietz, Florian A1 - Myrach, Philipp A1 - Rethmeier, Michael A1 - Suwala, H. A1 - Ziegler, Mathias T1 - Laser Based Spot Weld Characterization N2 - Spot welding is one of the most important joining technologies, especially in the automotive industry. Hitherto,the quality of spot welded joints is tested mainly by random destructive tests. A nondestructive testing technique offers the benefit of cost reduction of the testing procedure and optimization of the fabrication process, because every joint could be examined. This would lead to a reduced number of spot welded joints, as redundancies could be avoided. In the procedure described here, the spot welded joint between two zinc-coated steel sheets (HX340LAD+Z100MB or HC340LA+ZE 50/50) is heated optically on one side. Laser radiation and flash light are used as heat sources. The melted zone, the so called “weld nugget” provides the mechanical stability of the connection, but also constitutes a thermal bridge between the sheets. Due to the better thermal contact, the spot welded joint reveals a thermal behavior different from the surrounding material, where the heat transfer between the two sheets is much lower. The difference in the transient thermal behavior is measured with time resolved thermography. Hence, the size of the thermal contact between the two sheets is determined, which is directly correlated to the size of the weld nugget, indicating the quality of the spot weld. The method performs well in transmission with laser radiation and flash light. With laser radiation, it works even in reflection geometry, thus offering the possibility of testing with just one-sided accessibility. By using heating with collimated laser radiation, not only contactfree, but also remote testing is feasible. A further convenience compared to similar thermographic approaches is the applicability on bare steel sheets without any optical coating for emissivity correction. For this purpose, a proper way of emissivity correction was established. T2 - 42ND ANNUAL REVIEW OF PROGRESS IN QUANTITATIVE NONDESTRUCTIVE EVALUATION: Incorporating the 6th European-American Workshop on Reliability of NDE CY - Minneapolis, Minnesota, USA DA - 26.07.2015 KW - Laser PY - 2016 SN - 978-0-7354-1353-5 DO - https://doi.org/10.1063/1.4940570 VL - 1706 SP - 100010-1 EP - 100010-8 PB - AIP Publishing AN - OPUS4-35367 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Thiel, Erik A1 - Studemund, Taarna A1 - Ziegler, Mathias T1 - The VCSEL-Array - a Novel High-Power Light Source for (Photo) Thermal Imaging N2 - Within the field of optically excited thermography, full-field thermal imaging is used to characterize materials, to determine thicknesses of layers or to find inhomogeneities such as voids or cracks. Classical light sources, such as flash lamps (impulse heating) or halogen lamps (modulated heating), are hereby specifically used. This has led to the different testing methods lock-in and flash thermography. The VCSEL array promises to merge these excitation methods. Vertical Cavity Surface Emitting Lasers (VCSELs) are laser diodes emitting light perpendicular to their surface. Due to the vertical structure they can be arranged in large arrays of many thousand individual lasers and still be controlled like ordinary diode lasers. Recently a high-power albeit very compact version of such a VCSEL-array became available which offers both the fast timing behavior of lasers and large illumination areas. Moreover, it allows a spatial and temporal control of the heating because individual parts of the VCSEL-array can be controlled arbitrarily in frequency, amplitude, and phase. Although the VCSEL-array has a high potential for a new range of applications, it is too early to proclaim them. As one out of very few labs, we already adopted to this new VCSEL technology and show a thorough characterization and first results obtained with a 2.4 kW device. Specifically, we will discuss - the linearity between control voltage and optical output - the minimal pulse duration - the maximal applicable modulation frequency - optical projection and its influence on the optical output - spatial control of the illumination and thermal wave shaping Our results indicate that a VCSEL-array can be used for conventional impulse (aka flash) thermography whereas pulse duration and power are instantaneously accessible compared to flash lamp excitation. In case of lock-in thermography, we can apply frequencies in excess of 200 Hz without a loss in amplitude or an after glowing of the source, making it attractive for photo thermal applications. Consequently, this means that the VCSEL-array is able to merge the two main excitation methods lock-in and impulse thermography. T2 - 57th Course on Photoacoustic & Photothermal Phenomena CY - Erice, Italy DA - 19.10.2016 KW - VCSEL KW - Thermal Wave KW - Active Thermography PY - 2016 AN - OPUS4-37952 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - de Oliveira Guilherme Buzanich, Ana A1 - Radtke, Martin A1 - Reinholz, Uwe A1 - Riesemeier, Heinrich A1 - Emmerling, Franziska T1 - Time- & spatial-resolved X-ray absorption fine structure (XAFS) spectroscopy in a single-shot – new analytical possibilities for in situ material characterization N2 - A new concept that comprises both time- and lateral-resolved X-ray absorption fine-structure information simultaneously in a single shot is presented. This uncomplicated set-up was tested at the BAMline at BESSY-II (Berlin, Germany). The primary broadband beam was generated by a double multilayer monochromator. The transmitted beam through the sample is diffracted by a convexly bent Si (111) crystal, producing a divergent beam. This, in turn, is collected by either an energy-sensitive area detector, the so-called color X-ray camera, or by an area-sensitive detector based on a CCD camera, in θ-2θ geometry. The first tests were performed with thin metal foils and some iron oxide mixtures. A time resolution of lower than 1 s together with a spatial resolution in one dimension of at least 50 µm is achieved. KW - Time resolution KW - Single-shot XAFS PY - 2016 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-370892 DO - https://doi.org/10.1107/S1600577516003969 SN - 1600-5775 IS - 23 SP - 769 EP - 776 PB - International Union of Crystallography CY - Chester, UK AN - OPUS4-37089 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Hachmöller, O. A1 - de Oliveira Guilherme Buzanich, Ana A1 - Aichler, M. A1 - Radtke, Martin A1 - Dietrich, D. A1 - Schwamborn, K. A1 - Lutz, L. A1 - Werner, M. A1 - Sperling, M. A1 - Walch, A. A1 - Karst, U. T1 - Elemental bioimaging and speciation analysis for the investigation of Wilsons disease using μXRF and XANES N2 - A liver biopsy specimen from a Wilson’s disease (WD) patient was analyzed by means of micro-X-ray fluorescence (mXRF) spectroscopy to determine the elemental distribution. First, bench-top mXRF was utilized for a coarse scan of the sample under laboratory conditions. The resulting distribution maps of copper and iron enabled the determination of a region of interest (ROI) for further analysis. In order to obtain more detailed elemental information, this ROI was analyzed by synchrotron radiation (SR)-based mXRF with a beam size of 4 mm offering a resolution at the cellular level. Distribution maps of additional elements to copper and iron like zinc and manganese were obtained due to a higher sensitivity of SR-mXRF. In addition to this, X-ray absorption near edge structure spectroscopy (XANES) was performed to identify the oxidation states of copper in WD. This speciation analysis indicated a mixture of copper(I) and copper(II) within the WD liver tissue. KW - progressive hepatolenticular degeneration KW - mXRF Micro-X-ray fluorescence spectroscopy KW - XANES X-ray absorption near edge structure spectroscopy PY - 2016 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-360811 DO - https://doi.org/10.1039/C6MT00001K SN - 1756-5901 SN - 1756-591X PB - Royal Society of Chemistry CY - Cambridge AN - OPUS4-36081 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Simon, Franz-Georg T1 - Evaluation of waste management processes using VDI guideline 3925 N2 - The standard is intended to offer participants in waste management planning such as authorities, decision makers and planners, including the critical public, the possibility to learn about evaluation methods as planning instruments and place them in the context of planning decisions. The standard should help those who use it to formulate transparent decisions for the application of particular waste treatment and recovery methods in the scope of integrated waste management, thus reaching a documented decision under consideration of the system boundaries and life cycle inventories of the respective methods. T2 - Waste Reduction and Recycling: Challenges and Trends for Source Separation in China and Germany CY - Shanghai, China DA - 07.06.2016 KW - Mass balance KW - Energy balance KW - Life cycle assessment KW - Eco efficiency analysis KW - Exergy PY - 2016 AN - OPUS4-36623 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Fritzsche, André A1 - Avilov, Vjaceslav A1 - Bachmann, Marcel A1 - Gumenyuk, Andrey A1 - Hilgenberg, Kai A1 - Rethmeier, Michael T1 - Laserstrahlschweißen dicker Stahlplatten mit elektromagnetischer Schmelzbadunterstützung N2 - - EM-Schmelzbadunterstützung auch auf ferromagnetische Werkstoffe übertragbar - Erfolgreiche Kompensation des hydrostatischen Drucks von bis zu 20 mm dicken Werkstücken aus Duplex- und Baustahl - Benötigte AC-Leistung ist geringer als bei austenitischem Stahl Ausweitung der Experimente: - Einsatz von Zusatzwerkstoff beim Schweißen mit Duplexstahl - Schweißen von praxisrelevanten Bauteilen - Verwendung anderer Werkstoffe (z.B. Rohrstahl X65) T2 - Assistentenseminar 2016 der Wissenschaftlichen Gesellschaft Fügetechnik e.V. im DVS CY - Hotel Bollmannsruh am Beetzsee, Brandenburg, Germany DA - 05.09.2016 KW - Laserstrahlschweißen KW - Dickblechanwendung KW - Ferromagnetischer Stahl KW - Schmelzbadunterstützung PY - 2016 AN - OPUS4-38386 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Fritzsche, André A1 - Avilov, Vjaceslav A1 - Gumenyuk, Andrey A1 - Hilgenberg, Kai A1 - Rethmeier, Michael T1 - High power laser beam welding of thick-walled ferromagnetic steels with electromagnetic weld pool support N2 - The paper describes an experimental investigation of high power laser beam welding with an electromagnetic weld pool support for up to 20 mm thick plates made of duplex steel (AISI 2205) and mild steel (S235JR). The results of the welding tests show a successful application of this technology at ferromagnetic metals. Irregular sagging was suppressed successfully. An ac-power of less than 2 kW at oscillation frequencies between 800 Hz and 1.7 kHz is necessary for a full compasation of the hydrostatic pressure. Thus, it was demonstrated that the electromagnetic weld pool support is not only limited to non-ferromagnetic metals like austenitic steels. For future studies with duplex steel, the use of filler material has to take into account with regard to the balance of the mixed austenitic and ferritic phases. T2 - LANE - 9 International Conference on Photonic Technologies CY - Fürth, Germany DA - 19.09.2016 KW - Laser beam welding KW - Thick-walled steel KW - Ferromagnetic steel KW - Weld pool support PY - 2016 AN - OPUS4-37772 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Bandow, Nicole A1 - Simon, Franz-Georg T1 - Significance of cadmium from artists' paints to agricultural soils and the food chain N2 - Background: An Annex XV restriction dossier for cadmium in artists’ paints was submitted by an EU member state to the European Chemicals Agency ECHA. By cleaning used brushes under the tap cadmium can enter the food chain via waste water treatment and subsequent agricultural application of the sewage sludge. It was estimated that 110 kg Cd per year is spread on agricultural land via this exposure route. Other sources of Cd amount to almost 120 tons per year. Results: The mobility of Cd from pigments was studied in a field-like scenario by leaching experiments using soil samples amended with sewage sludge and spiked with Cd pigments in percolation columns. The redox conditions were confirmed to be the decisive factor for the release of Cd. The release of Cd from artists’ paints was in most cases 1% or lower in the experiments performed. Conclusions: Application of sewage sludge containing Cd from artist paints does not increase the amount of Cd leached from this soils. Furthermore the quantity of Cd from artists’ paints calculated in the restriction dossier is negligible compared to other sources of Cd to agricultural soil. Therefore ECHA did not consider the proposed restriction to be the most appropriate EU wide measure to address the negligible level of risk. KW - REACH regulation KW - Sewage sludge KW - Fertilizer KW - Leaching test PY - 2016 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-358261 DO - https://doi.org/10.1186/s12302-016-0077-6 SN - 2190-4715 VL - 28 IS - 12 SP - 1 EP - 10 AN - OPUS4-35826 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Fabry, Çağtay A1 - Pittner, Andreas A1 - Rethmeier, Michael T1 - Data-based process monitoring and control in narrow-gap GMAW N2 - An experimental setup to integrate laser sensor into conventional GMAW setups via a unified control architecture is described. The setup is used to automate and monitor narrow-gap GMAW. A way to develop GMAW arc-sensors using artificial neural networks using the setup is shown. The control system is connected to a relational database to store various process measurements. The database can be accessed to filter previous weldments by numerous criteria which allows modelling of process parameter correlation among vast datasets. Such models can be used for process monitoring and control in future applications. T2 - IIW Commission I, IV, XII / SG 212 Intermediate Meeting CY - Genova, Italy DA - 07.03.2016 KW - Narrow gap GMAW KW - MSG-Engspaltschweißen KW - Artificial neural networks KW - Profile measurement KW - GMAW control KW - Arc-sensing KW - Künstliche neuronale Netze KW - Profilvermessung KW - MAG Prozesssteuerung KW - Lichtbogensensorik PY - 2016 AN - OPUS4-35535 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Fabry, Çağtay A1 - Pittner, Andreas A1 - Rethmeier, Michael T1 - Automatisierungs- und Regelkonzepte für das MSG-Engspaltschweißen N2 - Es wird ein Versuchsstand zum automatisierten MSG-Engspaltschweißen mit integrierter Lasersensorik zur Prozessteuerung und -überwachung vorgestellt. Die Funktion einer Lichtbogensensorik zur automatischen Steuerung der mechanischen Elektrodenauslenkung wird erläutert und verschiedene Anwendungsfälle an Beispielen demonstriert. Die zusätzliche Füllgradregelung beim Mehrlagenschweißen mit veränderlichem Nahtquerschnitt auf Basis der optischen Messtechnik wird zudem vorgestellt. T2 - WGF Assistentenseminar 2016 CY - Paewesin, Germany DA - 06.09.2016 KW - Künstliche neuronale Netze KW - Arc-sensing KW - Lichtbogensensorik KW - MAG Prozesssteuerung KW - MSG-Engspaltschweißen KW - Profilvermessung KW - Artificial neural networks KW - GMAW control KW - Narrow gap GMAW KW - Profile measurement PY - 2016 AN - OPUS4-38294 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Fabry, Çağtay A1 - Pittner, Andreas A1 - Rethmeier, Michael T1 - Data-based process monitoring and control in narrow-gap GMAW N2 - An experimental setup to integrate laser sensor into conventional GMAW setups via a unified control architecture is described. The setup is used to automate and monitor narrow-gap GMAW and control the electrode weaving motion as well as the resulting height of each weld layer. A way to develop GMAW arc-sensors using artificial neural networks using the setup is shown. The control system is connected to a relational database to store various process measurements. The database can be accessed to filter previous weldments by numerous criteria which allows modelling of process parameter correlation among vast datasets. Such models can be used for process monitoring and control in future applications. T2 - 69th IIW Annual Assembly CY - Melbourne, Australia DA - 10.07.2016 KW - Arc-sensing KW - Künstliche neuronale Netze KW - Artificial neural networks KW - GMAW control KW - Narrow gap GMAW KW - Profile measurement KW - Lichtbogensensorik KW - MAG Prozesssteuerung KW - MSG-Engspaltschweißen KW - Profilvermessung PY - 2016 AN - OPUS4-38291 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Birk, A. M. A1 - Otremba, Frank A1 - Gonzales, F. A1 - Prabhakaran, A. A1 - Borch, Jörg-Peter A1 - Bradley, I. A1 - Bisby, L. ED - de Rademaeker, E. ED - Schmelzer, P. T1 - Fire testing of total containment pressure vessels N2 - Full engulfment fire tests have been conducted on total containment pressure vessels filled to 50% and 98 % capacity with water. The tests included an unprotected tank and tanks with two different levels of thermal protection. Total containment in this context means there was no pressure relief device. The tests were conducted with 1/3rd linear scale rail tank cars similar to the DOT 111 tank cars used in North America. The 2.4 m3 model tanks were subjected to 100 % engulfing fires fuelled by liquid propane. The fire heat flux was approximately 80 % by radiation and 20 % by convection with a total heat flux to a cool surface of approximately 100 kW/m2. T2 - 15th International Symposium on loss prevention and safety promotion (loss 2016) CY - Freiburg, Germany DA - 05.06.2016 KW - fire testing KW - hazmat tanks KW - integrity PY - 2016 SN - 978-88-95608-39-6 DO - https://doi.org/10.3303/CET1648047 VL - 48 SP - 277 EP - 282 PB - AIDIC CY - Milano, Italy AN - OPUS4-36361 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Boehm, Rainer A1 - Heckel, Thomas A1 - Jacob, S. A1 - Spruch, W. T1 - Automatisierte Prüfung von Radsatzwellen im eingebauten Zustand N2 - Der einwandfreie Zustand der Radsätze von Schienenfahrzeugen ist von größter Bedeutung für den sicheren Betrieb. Die Radsatzwellen werden durch eine große Zahl von Lastwechseln individuell unterschiedlich beansprucht. Dabei spielen viele Einflüsse wie äußere statische und dynamische Lasten, innere Lasten aufgrund von Unwuchten und inneren Spannungen und Umweltbedingungen entscheidende Rollen. Eine regelmäßige Prüfung ist daher obligatorisch. BTD entwickelt im Rahmen eines MNPQ-Projektes in Kooperation mit der BAM eine Phased Array Technik zur automatisierten Prüfung von Radsatzwellen im eingebauten Zustand. Die schwierigen Ankoppelbedingungen aufgrund der begrenzten Zugänglichkeit, der komplexen Geometrie und möglicherweise vorhandener Farbschichten und Schmutz auf der Radsatzwelle stellen hierbei große Herausforderungen dar. Um diesen zu begegnen, werden neben optimierten Prüfköpfen, einer in die Wasservorlaufstrecke integrierten akustischen Linse und einer speziellen Ankoppeltechnik auch Signalverarbeitungsalgorithmen eingesetzt. Die Darstellung der Signalverarbeitung ist der Schwerpunkt dieses Beitrages. Mit Hilfe von Messdatensätzen präparierter Testwellen werden verschiedene Algorithmen erprobt und hinsichtlich der Stabilität, dem Verhalten bezüglich der Ankoppelschwankungen und veränderter Wellengeometrien und der Fähigkeit zur automatischen Unterscheidung von Fehler- und Formanzeigen bewertet. Letztlich wird die beste Lösung im entwickelten Prüfsystem eingesetzt. T2 - 9. Fachtagung ZfP im Eisenbahnwesen CY - Wittenberge, Germany DA - 15.03.2016 KW - Automatisierte Ultraschallprüfung KW - Radsatzwellen KW - Signalverarbeitung KW - Akustische Linse PY - 2016 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-370545 AN - OPUS4-37054 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Jakubowski, Norbert A1 - Müller, Larissa A1 - Traub, Heike A1 - Esteban-Fernández, Diego A1 - Panne, Ulrich A1 - Herrmann, Antje A1 - Schellenberger, E. A1 - Kneipp, Janina T1 - Bio- and immuno-imaging by use of laser ablation ICP-MS N2 - Imuno-histochemical staining (IHC) of cancer biomarker on tissue sections is one of the most important analytical techniques for cancer diagnosis although standardization and quality management is tedious and differ significantly from clinic to clinic. Combining established IHC staining strategies with modern quantitative methods would increase it`s potential. We used element mass spectrometry (ICP-MS) and a new ink-jet printed internal standardization approach in combination with IHC staining. The printing strategy was utilized to improve elemental image resolution and reproducibility of paraffin embedded breast cancer tissue sections in laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) after conventional IHC staining as a model system to investigate the new capabilities of this technique. T2 - Ringvorlesung Analytik, Humboldt Universität zu Berlin CY - Berlin, Germany DA - 10.06.2016 KW - Laser ablation KW - Bio-imaging KW - Immuno-assays PY - 2016 AN - OPUS4-36476 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Fittschen, U. A1 - de Oliveira Guilherme Buzanich, Ana A1 - Böttger, S. A1 - Rosenberg, D. A1 - Menzel, M. A1 - Jensen, W. A1 - Busker, M. A1 - Gotlib, Z. A1 - Radtke, Martin A1 - Riesemeier, Heinrich A1 - Wobrauschek, P. A1 - Streli, C. ED - de Oliveira Guilherme Buzanich, Ana T1 - A setup for synchrotron-radiation-induced total reflection X-ray fluorescence and X-ray absorption near-edge structure recently commissioned at BESSY II BAMline N2 - An automatic sample changer chamber for total reflection X-ray fluorescence (TXRF) and X-ray absorption near-edge structure (XANES) analysis in TXRF geometry was successfully set up at the BAMline at BESSY II. TXRF and TXRF-XANES are valuable tools for elemental determination and speciation, especially where sample amounts are limited (<1 mg) and concentrations are low (ng ml⁻¹ to μg ml⁻¹). TXRF requires a well defined geometry regarding the reflecting surface of a sample carrier and the synchrotron beam. The newly installed chamber allows for reliable sample positioning, remote sample changing and evacuation of the fluorescence beam path. The chamber was successfully used showing accurate determination of elemental amounts in the certified reference material NISTwater 1640. Low limits of detection of less than 100 fg absolute (10 pg ml⁻¹) for Ni were found. TXRF-XANES on different Re species was applied. An unknown species of Re was found to be Re in the +7 oxidation state. KW - TXRF KW - TXRF-XANES KW - Sample changer KW - BAMline KW - Re-XANES PY - 2016 DO - https://doi.org/10.1107/S1600577516001995 SN - 1600-5775 VL - 23 IS - 3 SP - 820 EP - 824 PB - International Union of Crystallography AN - OPUS4-38656 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wurzler, Nina A1 - de Oliveira Guilherme Buzanich, Ana A1 - Radtke, Martin A1 - Reinholz, Uwe A1 - Emmerling, Franziska A1 - Kunte, Hans-Jörg A1 - Özcan Sandikcioglu, Özlem T1 - Investigation of the mechanisms of microbially induced corrosion on Fe/steel surfaces N2 - The role of metal reducing bacteria (MRB) in corrosion is being controversially discussed in the literature. They can utilize metals including iron, uranium and manganese as well as many organic compounds as electron acceptors. The reduction of Fe(III) compounds to soluble Fe(II) species leads to the destruction of passive films on steel, resulting in acceleration of general and local corrosion processes. Recent research shows that the secretion of electron shuttles like riboflavins also contribute to the extracellular electron transfer (EET). The aim of this project is to understand the chemical and electrochemical interaction mechanisms of MRB with steel surfaces by means of combined in situ techniques. An electrochemical XANES (x-ray absorption near edge spectroscopy) cell has been designed to study the changes of passive film chemistry in the presence of biomolecules and MRB. Electrochemical quartz crystal microbalance (eQCM) is used for studying the kinetics of bacterial cell attachment and diffusion of biomolecules in model biofilms. In situ investigations are complemented by ex situ spectroscopic and microscopic analysis to investigate the biofilm structure, composition and cell viability. Via the combination of electrochemical methods with spectroscopic techniques and QCM we are able to follow biological processes and resulting degradation of steel surfaces in a non-destructive manner. The selection of model systems and a defined biological medium allows the identification of the effects of individual surface and environmental parameters. The fundamental understanding of bacterial attachment mechanisms and initial steps of biofilm formation will contribute to the development of new antifouling strategies. T2 - Electrochemistry 2016 CY - Goslar, Germany DA - 26.09.2016 KW - MIC KW - Microbiologically influenced corrosion KW - XANES KW - Electrochemistry PY - 2016 AN - OPUS4-38199 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kabelitz, Anke A1 - de Oliveira Guilherme Buzanich, Ana A1 - Reinholz, Uwe A1 - Radtke, Martin A1 - Bienert, Ralf A1 - Schulz, K. A1 - Kraehnert, R. A1 - Emmerling, Franziska T1 - Time-resolved studies on the formation of maghemite nanoparticles combining fast-XANES and SAXS N2 - Iron oxide nanoparticles find application in different areas like sensing, magnetic storage media, and biomedicine, due to their magnetic properties and environment-friendliness. In the present contribution, we report on the in situ investigation of an iron oxide nanoparticle synthesis by coupled X-ray absorption near-edge structure (XANES) and small-angle X-ray scattering (SAXS). The combination provides simultaneously information about the size of particles (SAXS) and on the oxidation state and the local structure of the iron atoms (XANES). The co-precipitation synthesis was exemplary studied, using a stabilization agent to decelerate the fast precipitation of the iron oxides. This allows to detect intermediates in situ. The measurements were performed using a custom-made acoustic levitator as sample holder. From the data, a mechanism was derived indicating different phases of particle Formation and oxidation state changes. T2 - The European Materials Research Society-Spring Meeting 2016 CY - Lille, France DA - 01.05.2016 KW - Iron oxide nanoparticles KW - SAXS KW - XANES KW - Time-resolved PY - 2016 AN - OPUS4-36351 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Hahn, Oliver A1 - Denker, A. A1 - Merchel, S. A1 - Radtke, Martin A1 - Reinholz, Uwe A1 - Wolff, T. ED - Armbruster, B. ED - Eilbracht, H. ED - Hahn, Oliver ED - Heinrich-Tamaska, O. T1 - Zerstörungsfreie Analyse von Metallartefakten - Eine Fallstudie N2 - Die naturwissenschaftliche Analyse historischer Materialen ermöglicht die Beantwortung kulturhistorischer Fragestellungen, die mit kunsthistorischen oder archäologischen Ansätzen allein nicht zu leisten sind. In dieser Studie wurden sechs römische Münzen mit unterschiedlich stark ausgeprägten Korrosionsschichten an unbehandelten und polierten Stellen mit vier zerstörungsfreien analytischen Methoden untersucht: Hoch- und Niederenergie Protonen Induzierter Röntgenemission (HE-/PIXE), Synchrotronstrahlungsinduzierte-Röntgenfluoreszenzanalyse (SY-RFA) und Mikro-Röntgenfluoreszenzanalyse (Mikro-RFA) mit einem mobilen Gerät. Aufgrund von Unterschieden in den Messbedingungen und dem Einfluss der Patina-Schichten auf diese ergaben sich nur für wenige Elemente Übereinstimmungen in den quantitativen Daten. Zur Validierung zukünftiger Messkampagnen mit verschiedenen Methoden sind daher Vergleichstudien unerlässlich. N2 - Investigations of physical properties and chemical composition of ancient materials generate important data for answering culture-historical questions that cannot be solved by art historical and archaeological methods alone. This contribution reports on the analysis of six Roman coins, with different degrees of corrosion layers in parts that were not handled or polished, using four non-destructive methods: low-energy particle-induced X-ray emission (PIXE, 2 MeV), high-energy PIXE (68 MeV), μ-X-ray fluorescence (XRF) spectrometry with a portable device and synchrotron-radiation induced XRF. Because of differences in the conditions needed for measurement and the influence of the layers of patina on these measurements, there were few elements where the quantitative data were in agreement. Thus comparative analyses are essential to validate future measurement projects using different methods. KW - Zerstörungsfreie Prüfung KW - Protoneninduzierte Röntgenemission KW - Röntgenfluoreszenzanalyse KW - Non-destructive testing KW - Particle-induced X-ray emission KW - X-ray fluorescence analysis PY - 2016 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-385702 SN - 978-3-9816751-5-3 VL - Berlin studies of the ancient world, Band 35 SP - 117 EP - 137 PB - Edition Topoi CY - Berlin AN - OPUS4-38570 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Vogel, Christian A1 - Rivard, C. A1 - Tanabe, I. A1 - Adam, Christian T1 - Microspectroscopy – promising techniques to characterize phosphorus in soil N2 - Phosphorus (P) is an essential element for all forms of life and is applied as fertilizer in agriculture. The P availability for plants may be highly dependent on the chemical state of P in fertilizers and soils; however, the nature of this dependence remains obscure due to the limitations of generally applied wet chemical and instrumental analytical approaches. This paper focuses on recently developed infrared, Raman, ultraviolet and X-ray microspectroscopic techniques for the characterization of P in soil. Microspectroscopic techniques have the advantage that discrete P phases can be distinguished and characterized even if their mass fractions are very low. However, only small volumes of soil can be analyzed by microspectroscopic methods hence a combination of macro- and microspectroscopic techniques is a promising concept. KW - Infrared KW - Microspectroscopy KW - Phosphorus KW - Raman KW - Soil KW - Ultraviolet KW - X-ray absorption near-edge structure (XANES) PY - 2016 DO - https://doi.org/10.1080/00103624.2016.1228942 SN - 0010-3624 SN - 1532-2416 VL - 47 IS - 18 SP - 2088 EP - 2102 AN - OPUS4-38341 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Steckenmesser, D. A1 - Vogel, Christian A1 - Steffens, D. T1 - P-Verfügbarkeit von Recyclingprodukten N2 - Die Pflanzenversuche der vorliegenden Arbeit zeigen sehr gut, dass das Pyrolyse Produkt der Firma Pyreg zwar in der kurzfristigen P-Verfügbarkeit nur mäßig abschnitt, dafür aber eine gute P-Nachlieferung aufweist. Dies kann maßgeblich auf die im Produkt vorliegenden P-Verbindungen zurückgeführt werden.Es zeigt sich weiterhin, dass durch eine Na2CO3-Gabe die kurzfristige Verfügbarkeit von eisengefällten Klärschlämmen verbessert werden kann, es aber keinen Einfluss auf die langfristige P-Nachlieferung hat. Das BAM-Verfahren mit Na2SO4 liefert ein Produkt, welches sowohl eine gute kurzfristige P-Verfügbarkeit, als auch eine gute langfristige P-Nachlieferung hat. Dies kann auf die dabei entstehende P-Form, CaNaPO4, zurückgeführt werden. Ferner zeigen die Experimente, dass auch schwerlösliche Phosphate mit N2-fixierendem Rotklee mobilisiert werden können. T2 - 128. VDLUFA-Kongress CY - Rostock, Germany DA - 13.09.2016 KW - Phosphor KW - Recycling KW - Düngemittel PY - 2016 SN - 978-3-941273-23-8 SP - 57 EP - 73 PB - VDLUFA-Verlag CY - Darmstadt AN - OPUS4-38906 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Adam, Christian A1 - Vogel, Christian A1 - Rivard, C. A1 - Wilken, V. A1 - Muskolus, A. T1 - Unravelling plant-availability of recovered P-fertilizers by pot experiments and P X-ray absorption near edge structure (XANES) spectroscopy N2 - Pot experiments are often performed to analyze the plant-availability of phosphorus (P) in P-fertilizers. However, these experiments do not determine the P compounds present in the soil which are responsible for the yield increase. In order to better understand the results of pot experiments we analyzed the soils by P K-edge X-ray absorption near-edge structure (XANES) spectroscopy to determine the P species and unravel transformation processes. We carried out pot experiments with maize testing different waste water derived recycling P-fertilizers on an acidic and a neutral soil. Soils samples before sowing and after harvest were collected and prepared for analysis. A combination of macro- and µ-XANES spectroscopy was used to determine the chemical state of the overall soil P and to identify P compounds in P-rich spots localized by micro-X-ray fluorescence (µ-XRF). P K-edge macro-XANES spectroscopy detected organic P and/or P sorbed onto organic matter or other substrates in the unfertilized and fertilized soils. In addition, µ-XRF mapping in combination with P K-edge µ-XANES spectroscopy evidenced that some P phases present in recycling P-fertilizers (magnesium phosphate and calcium sodium phosphate) react with co-fertilized ammonium nitrate and form highly plant-available ammonium phosphates in the soil. In opposite, apatites were not affected by the presence of ammonium. Thus, for a boost of the plant-availability of P in recycling P-fertilizers these fertilizers should be directly co-fertilized with nitrogen (N) sources that contain a high amount of ammonium instead of nitrate. Possibly, a specific preparation of NP-fertilizers by granulation of recycling P-fertilizers with ammonium compounds and a nitrification inhibitor could enhance the plant-availability of the produced fertilizer whereby they become more competitive to commercially available NP-fertilizers based on phosphate rock. T2 - IPW8 - International Phosphorus Workshop CY - Rostock, Germany DA - 12.09.2016 KW - Phosphorus fertilizer KW - XANES spectroscopy PY - 2016 AN - OPUS4-37376 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Steckenmesser, D. A1 - Vogel, Christian A1 - Adam, Christian A1 - Steffens, D. T1 - Effect of various thermochemical treatments on phosphorus speciation, solubility, and bioavailability of sewage sludge ashes and carbonizates N2 - Sewage sludge has one of the highest phosphorus (P) potentials of all waste materials. Therefore, P-recycling from sewage sludge could contribute to close the P-cycle. Recently, various processes for P-recovery have been developed, but most of them were not established in industrial scale due to their poor economic feasibility. In the present study, two common methods (low-temperature conversion at 400-500°C and thermochemical treatment at 950-1000°C were investigated and combined to produce highly bioavailable P-fertilizers from two different types of sewage sludge based on chemical phosphorus precipitation with FeCl2 and enhanced biological phosphorus removal. T2 - Ressourceneffizienz: von Modellpflanzen zu Nutzpflanzen und Agrarsystemen CY - Hohenheim, Germany DA - 28.09.2016 KW - Phosphorus recovery KW - Sewage sludge PY - 2016 AN - OPUS4-37685 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Baeßler, Matthias A1 - Hille, Falk A1 - Said, Samir ED - Baeßler, Matthias ED - Rogge, Andreas ED - Möller, Gerd ED - Schiefelbein, Norbert T1 - Bauwerksüberwachung von Brücken im Kontext saisonaler Einflüsse N2 - Anhand verschiedener Bespiele wird diskutiert, wie Temperaturbeanspruchungen in einer Bauwerksüberwachung sichtbar werden und wie sie zu bewerten sind. Insbesondere der Einfluss auf die Zustandsbewertung im Sinne der Standsicherheit stellt häufig eine große Schwierigkeit dar. Behelfsweise besteht eine grundlegende Möglichkeit darin, ein Tragwerk immer zu seiner schwächsten Phase, d.h. in der Regel im Sommer zu beurteilen. Wie aufgezeigt, können zudem statistische Verfahren geeignet sein, Tragfähigkeitsänderungen zu detektieren. Als wesentliche Zukunftsaufgaben werden verbesserte Detektionsalgorithmen und physikalisch begründete Modelle zum mechanischen Verhalten angesehen. Die Akzeptanz schwingungsbasierter Verfahren zur Detektion und Lokalisierung von Schäden in der praktischen Anwendung ist alleinig von der Fähigkeit abhängig, Einflüsse aus veränderlichen Umwelt- und Betriebsbedingungen, insbesondere aber die aus der Temperatur zu eliminieren. Da die in den letzten Jahren immer wichtiger werdenden stochastischen Verfahren zur Schadensde-tektion und -lokalisierung die (statistische) Charakteristik der Messdaten bereits implizit nutzen, sind hier Entwicklung, Anpassung und Anwendung statistischer Algorithmen zur Eliminierung der variierenden Umwelteinflüsse naheliegend. Auf der anderen Seite wird der saisonale Einfluss auf Bauwerksmessungen in sehr vielen Veröf-fentlichungen dargestellt und es werden häufig verdachtsweise begründete physikalische Zu-sammenhänge für das Verhalten aufgezeigt. Im Regelfall sind die Aussagen aber nicht experi-mentell überprüft und von eher allgemeiner Natur („Asphalt reagiert temperaturabhängig“). Ob-jektspezifische Zusammenhänge, beispielsweise über Versuch an Repräsentanten in der Klima-kammer ermittelt, könnten jedoch sehr hilfreich sein. T2 - Messen Im Bauwesen CY - BAM, Berlin, Germany DA - 08.11.2016 KW - Bauwerksüberwachung KW - SHM KW - Temperatureinfluss PY - 2016 SN - 978-3-9817853-6-4 VL - 2016 SP - 89 EP - 102 PB - Eigenverlag BAM AN - OPUS4-39354 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CHAP A1 - Baeßler, Matthias A1 - Cuéllar, Pablo A1 - Georgi, Steven A1 - Karabeliov, Krassimire A1 - Rücker, Werner A1 - Johnsen, Björn ED - Durstewitz, M. ED - Lange, B. T1 - „Neuland“ auf dem Meeresboden - Überwachungsverfahren und Bewertungsmodell für die Gründung von Offshore-Windenergieanlagen N2 - Offshore-Windenergie betritt Neuland, gerade bei der Gründung. Denn Windenergie auf See kann die Erfahrungen der gängigen Offshore-Konstruktionen der Öl- und Gasindustrie nur bedingt nutzen. Mehr als dort, versucht man bei der Offshore-Windenergie, die Gründungsabmessungen – insbesondere die Pfahllängen – soweit wie möglich zu reduzieren. Denn dies kann bei der hohen Anzahl der Windenergieanlagen erhebliche wirtschaftliche Vorteile bringen. Andererseits wird die Standsicherheit der Gründungen durch den viel höheren Anteil an zyklischen Lasten gegenüber den gängigen Offshore- Strukturen in schwer einschätzbarer Weise zusätzlich gefährdet. Da Offshore-Windenergieanlagen in Serienfertigung produziert werden, wirkt sich hier jeder systematische Fehler bei der Gründung dann gleich als Serienfehler auf eine Vielzahl von Anlagen aus. Überwachung ist also angesagt – und das richtige Maß bei der Pfahlgründung, der am meisten verwendete Fundamenttyp bei Windenergieanlagen. KW - Offshore Windkraftanlagen KW - Pfahlgründungen KW - Überwachungsverfahren PY - 2016 SN - 978-3-658-09782-0 SN - 978-3-658-09783-7 DO - https://doi.org/10.1007/978-3-658-09783-7 SP - 61 EP - 68 PB - Springer AN - OPUS4-39348 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CHAP A1 - Rücker, Werner A1 - Cuéllar, Pablo A1 - Georgi, Steven A1 - Karabeliov, Krassimire A1 - Baeßler, Matthias A1 - Johnsen, Björn ED - Durstewitz, M. ED - Lange, B. T1 - Schieflagen bitte vermeiden N2 - Vieles ist möglich, auch auf dem Meeresboden. Wind und Wellen rütteln gemeinsam an der Gründung, den Fundamenten der Offshore-Windenergieanlagen. Hinzu kommen die „ganz normale“ Strömung sowie die in der Nordsee besonders ausgeprägten Gezeiten von Ebbe und Flut. Zudem kann am Meeresboden Porenwasserüberdruck entstehen, der den Boden lockern und im schlimmsten Fall bei Monopiles die Stabilität der gesamten Anlage ändern kann. Selbst wenn ein solcher in den Meeresboden gerammter Pfahl bis zu 8 Meter Durchmesser hat. Über die Hälfte der geplanten Offshore-Anlagen in Nord- und Ostsee werden mit Ein-Pfahl-Gründungen geplant, über 40 % sollen als Mehrpfahl-Gründungen, zum Beispiel als Tripod, ausgeführt werden. Von daher verdienen Pfahlgründungen und ihre Belastungen besondere Aufmerksamkeit. Denn eines gilt es im Anlagenbetrieb unbedingt zu vermeiden: Eine drohende Schiefstellung der Anlage KW - Windenergie KW - Offshore KW - Pfahlgründungen PY - 2016 SN - 978-3-658-09782-0 DO - https://doi.org/10.1007/978-3-658-09783-7 SP - 53 EP - 59 AN - OPUS4-39344 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Zorn, Sebastian A1 - Unger, Jörg F. A1 - Schneider, Ronald ED - Silva Gomes, J. F. ED - Meguid, S. A. T1 - A probabilistic method for identification of vehicle loads and system parameters for reinforced concrete bridges N2 - Growth of vehicle traffic density can be observed in many countries all over the world. This accretion is caused by world-wide population growth on the one hand, but also by increasing freight volumes and, thus, freight transports on the streets on the other hand. This increased exposure becomes more and more of a problem for the civil infrastructure such as bridges. Many of these bridges are nowadays stressed to their limits by higher loads than they were originally designed for and/or operating times beyond the initially predicted life span. This raises questions about structural safety and lifetime prediction, of course, and therefore illustrates the need for accurate structural monitoring. Since the lifetime of bridge structures is primarily influenced by their traffic loading, an accurate identification of load configurations over the whole length of a structure is most desirable. In this paper, a method for vehicle load identification is proposed. It involves Bayesian Analysis and (quasi-)static importance functions in order to estimate vehicle positions, velocities and weights. The structure is modeled with finite elements in order to generate model predictions for different load configurations. The model predictions are compared to the actual measured data to identify the most probable loading configuration for that measurement. This involves the use of enhanced Monte Carlo simulations such as MCMC to reduce the computational effort. The measured data from different kinds of sensors can (and should) be combined for accuracy gain – in this case a combination of measured displacements and inclinations. Since the measurements take place over some time during the passage of the vehicle, these estimations are carried out for several time instants for which the estimation is carried out. The advantage of using Bayesian Updating Method is the embodied learning effect leading to an improvement of the estimation when adding new information in a new calculation step. Using the estimates for the loading conditions of a bridge structure as well as measurements of the structural responses, Bayesian analysis is again used in order to estimate localized structural parameters such as Young's modulus or Moments of Inertia in form of probability density functions yielding most probable values for the parameters. Considering the difficulties for load identification close to the support poles of the bridge and therefore for the proposed structural parameter identification procedure, it is clear that this problem is ill posed. Bayesian regularization methods also have proven to be very effective when handling ill posed problems. T2 - IRF2016 - Integrity Reliability Failure CY - Porto, Portugal DA - 24.07.2016 KW - Vehicle load identification KW - Structural health monitoring KW - Bayesian updating method PY - 2016 SN - 978-989-98832-4-6 VL - 2016 SP - PAPER REF: 6294-575 EP - 576 PB - INEGI-Instituto de Ciencia e Inovacao em Engenharia Mecanica e Gestao Industrial CY - Porto - Portugal AN - OPUS4-39833 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Baeßler, Matthias T1 - Vorstellung der Forschungsaktivitäten "Offshore" und TF-Projekt Lebewind N2 - Im Vortrag werden die Aktivitäten der BAM im Bereich Offshore Wind und schwerpunktmäßig im Bereich 7.2 dargestellt. Hierzu gehören die Forschungsaktivitäten insbesondere zu den Gründungen der Tragstrukturen. Übergreifend wird das TF Projekt Lebewind vorgestellt. T2 - BAM-IFAM Kolloquium Mikrobiell induzierte Korrosion im Stahlwasserbau CY - BAM, Berlin, Germany DA - 01.12.2016 KW - Offshore KW - Lebewind KW - Windenergie PY - 2016 AN - OPUS4-39350 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Baeßler, Matthias A1 - Said, Samir A1 - Hille, Falk T1 - The influence of varying temperature on measures of bridge health monitoring N2 - It is widely recognized that the dynamics of large civil structures, such as bridges or offshore structures, is significantly affected by temperature and other environmental influences. The most significant effect on the structural stiffness is due to temperature variations and especially due to the thermal gradients within the structures cross section. For civil engineering structures, changes in the dynamic response produced by varying environmental conditions can be equivalent or greater than the ones produced by damage. Therefore, handling the environmental effects has become a major research field for global Structural Health Monitoring. A number of methods and techniques have been developed for addressing this issue for different civil engineering application examples. An additional question is if temperature changes of stiffness correlate with a change in safety level of the structures bearing capacity which has to be discussed case dependent In our contribution we show the result of an extensive literature review on the matter of varying temperature, describing the characteristic effects on the structure as well as the various approaches to that issue, including the experiences our work group has gained in the last 20 years of SHM on civil engineering structure. T2 - Civil Structural Health Monitoring Workshop (CSHM-6) CY - Queen's University Belfast, UK DA - 26.05.2016 KW - Monitoring KW - Temperature KW - SHM PY - 2016 AN - OPUS4-39351 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Rütters, H. A1 - Stadler, S. A1 - Bäßler, Ralph A1 - Bettge, Dirk A1 - Jeschke, S. A1 - Kather, A. A1 - Lempp, C. A1 - Lubenau, U. A1 - Ostertag-Hennig, C. A1 - Schmitz, S. A1 - Schütz, S. A1 - Waldmann, S. T1 - Towards an optimization of the CO2 stream composition - A whole-chain approach N2 - CO2 streams captured from power stations or industrial plants may contain impurities that impact the consecutive steps of the CO2 capture and storage (CCS) chain. As the basis for an optimization of CO2 purity over the whole CCS chain, impacts of different impurities were investigated at key steps including studies on (i) corrosion of metallic materials in CO2 streams and brine, (ii) fluid and interfacial properties as a function of pressure, temperature and CO2 stream composition and their implications for CO2 transport, injection and geological storage, (iii) costs of different pipeline design options, (iv) geochemical alterations at typical reservoir conditions and their implications for geomechanical rock properties. Major findings are synthesized for two exemplary single source-single sink CCS chain scenarios involving CO2 stream compositions typical for pre-combustion capture and oxyfuel combustion. Recommendations for material selection for compression, transport and injection were derived for various CO2 stream compositions. To reliably control corrosion, a limitation of water contents to 50 ppmv is recommended for pipeline transportation of all CO2 streams. At geological storage conditions, the presence of either O2, NOx or SO2 only weakly affected fluid-mineral/rock interactions that still impacted geomechanical rock properties. KW - CCS KW - Impurities KW - Associated incidental substances KW - Pipeline design KW - Corrosion KW - Fluid-rock interactions PY - 2016 UR - http://www.sciencedirect.com/science/article/pii/S1750583616305047 DO - https://doi.org/10.1016/j.ijggc.2016.08.019 SN - 1750-5836 SN - 1878-0148 VL - 54 IS - 2 SP - 682 EP - 701 PB - Elsevier AN - OPUS4-38401 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Thiele, Marc A1 - Petryna, Y. A1 - Rogge, Andreas A1 - Baeßler, Matthias T1 - Experimental investigation of fatigue process in concrete under high-cycle loading N2 - Fatigue is of relevance not only for metals but also for concrete. The current knowledge about fatigue behaviour of concrete is, however, incomplete. This concerns especially the progress of fatigue which precedes the fatigue failure. Some macroscopic effects of this process are well known but the governing material changes behind them are still less studied. The focus of the present contribution lay on a systematic and comprehensive investigation of the fatigue process under cyclic compressive loading. The aim was to obtain a deeper insight and to provide a better understanding of the damage process in the material. Cylindrical specimens were tested with a number of cycles to failure between 106 and 107. Various methods of non-destructive and destructive testing were used to investigate macroscopic and microscopic changes in the material. One main result was that the changes in the macroscopic material behaviour could not be explained only by the development of micro cracks. The results indicated that the related changes in the fatigue behaviour originate rather from viscous processes in the cement stone, similar to the process of creep. A sound description of the possible processes was derived from the obtained experimental results which concerns material structure during fatigue loading. It has been shown that in case of isotropic material behaviour a stiffness reduction related to a scalar value could not capture the damage effect on the stress-strain relationship caused by fatigue. T2 - fib symposium 2016 CY - Cape Town, South Africa DA - 21.11.2016 KW - High-cycle KW - Fatigue KW - Concrete KW - Damage evolution PY - 2016 AN - OPUS4-38721 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Baeßler, Matthias A1 - Said, Samir A1 - Hille, Falk T1 - Bauwerksüberwachung von Brücken im Kontext saisonaler Einflüsse N2 - Im Übersichtsvortrag wird anhand verschiedener Bespiele dargestellt, wie Temperaturbeanspruchungen in einer Bauwerksüberwachung sichtbar werden und wie sie zu bewerten sind. Insbesondere der Einfluss auf die Zustandsbewertung im Sinne der Standsicherheit stellt häufig eine große Schwierigkeit dar. Behelfsweise besteht eine grundlegende Möglichkeit darin, ein Tragwerk immer zu seiner schwächsten Phase, d.h. in der Regel im Sommer zu beurteilen. Wie aufgezeigt, können zudem statistische Verfahren geeignet sein, Tragfähigkeitsänderungen zu detektieren. Als wesentliche Zukunftsaufgaben werden verbesserte Detektionsalgorithmen und physikalisch begründete Modelle zum mechanischen Verhalten angesehen. T2 - Tagung "Messen im Bauwesen" 2016 CY - BAM, Berlin, Germany DA - 04.11.2016 KW - Bauwerksüberwachung KW - Temperatur PY - 2016 AN - OPUS4-39353 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Baeßler, Matthias A1 - Jahnke, T. A1 - Kidane, M. T1 - Bemessung axial belasteter Offshore-Rammpfähle in der AWZ: Anforderungen, Erfahrungen und Empfehlungen N2 - Im Vortrag wird die regelhafte Bemessung axial belasteter Offshore-Rammpfähle in der Ausschließlichen Wirtschaftszone (AWZ) beschreiben. Hierbei werden die regulatorischen Grundlagen und spezifische technische und anwendungsspezifische Erfahrungen dargestellt. T2 - Offshore Tage CY - TU Berlin, Germany DA - 17.03.2016 KW - Offshore KW - Rammpfähle KW - Bemessung PY - 2016 AN - OPUS4-39352 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Baeßler, Matthias T1 - Bauteilprüfungen mit großen Kräften N2 - Darstellung der Prüfmöglichkeiten mit großen Kräften für Bauteile in der Abteilung 7 der BAM. T2 - 301. PTB-Seminar CY - Braunschweig, Germany DA - 17.10.2016 KW - Bauteilprüfungen KW - Großprüfmaschinen PY - 2016 AN - OPUS4-39349 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Vogel, Christian A1 - Krüger, Oliver A1 - Herzel, Hannes A1 - Amidani, L. A1 - Adam, Christian T1 - Chemical state of mercury and selenium in sewage sludge ash based P-fertilizers N2 - Phosphorus-fertilizers from secondary resources such as sewage sludge ash (SSA) will become more important in the future as they could substitute conventional fertilizers based on the nonrenewable resource phosphate rock. Thermochemical approaches were developed which remove heavy metals from SSA prior to its fertilizer application on farmlands. We analyzed the chemical state of mercury and selenium in SSA before and after thermochemical treatment under different conditions for P-fertilizer production by X-ray absorption near edge structure (XANES) spectroscopy. In some incineration plants the mercury loaded carbon adsorber from off-gas cleaning was collected together with the SSA for waste disposal. SSAs from those plants contained mercury mainly bound to carbon/organic material. The other SSAs contained inorganic mercury compounds which are most probably stabilized in the SSA matrix and were thus not evaporated during incineration. During thermochemical treatment, carbon-bound mercury was removed quantitatively. In contrast, a certain immobile fraction of inorganic mercury compounds remained in thermochemically treated SSA, which were not clearly identified. HgSe might be one of the inorganic compounds, which is supported by results of Se K-edge XANES spectroscopy. Furthermore, the chemical state of selenium in the SSAs was very sensitive to the conditions of the thermochemical treatment. KW - X-ray absorption near edge structure (XANES) spectroscopy KW - Phosphorus recovery KW - Sewage sludge ash KW - Mercury KW - Selenium KW - Mercury selenide (HgSe) PY - 2016 UR - http://dx.doi.org/10.1016/j.jhazmat.2016.03.079 DO - https://doi.org/10.1016/j.jhazmat.2016.03.079 VL - 313 SP - 179 EP - 184 PB - Elsevier B.V. CY - Amsterdam, Netherlands AN - OPUS4-35718 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Adam, Christian A1 - Herzel, Hannes A1 - Stemann, Jan A1 - Hermann, Ludwig A1 - Krüger, Oliver T1 - A thermochemical process for fertilizer production from sewage sludge ashes investigated from lab to industrial scale N2 - Sewage sludge ashes (SSA) contain up to 13% P and are thus promising raw materials for fertilizer production. However, SSAs also contain heavy metals and the main P-bearing mineral phases whitlockite and aluminium phosphate are poorly bioavailable. We developed and patented a process that produces fertilizers from SSA addressing the above mentioned challenges. SSA is thermo-chemically treated at ~950°C under reducing conditions (reductive: dry sewage sludge) in a rotary kiln together with an alkali compound such as sodium or potassium sulfate, hydroxide or carbonate. Some undesired trace elements such as As, Hg, Pb and Cd are evaporated and separated via off gas treatment system. The poorly soluble phosphates are transformed into calcium alkali phosphates (CaNaPO4 or CaKPO4) that are not water soluble but completely soluble in neutral ammonium citrate solution (NAC). Pot experiments showed that the fertilizer performance of the treated SSA containing calcium alkali phosphates as the single P-bearing mineral phase was comparable to the performance of triple superphosphate. The PNAC-solubility of fertilizer products correlated very well with the resulting contents of calcium alkali phosphates and the P-uptake of plants in pot experiments. The effect of the ratio alkali/P on the PNAC-solubility was investigated by crucible experiments and trial series with a medium scale rotary kiln using different SSAs and alkali phosphates. The effects of operational parameters such as the temperature and the retention time were investigated as well as concurring side reactions of the alkali compounds e.g. with SiO2 present in SSA. The alkali/P ratio must be roughly adjusted at 2 to achieve 100% PNAC-solubility for a common type of SSA. A demonstration trial with an output of 2 t recycling fertilizer was carried out in an industrial rotary kiln (product output 30 kg/h). The PNAC-solubility of the product varied between 60% and 80% during the 4 days campaign showing that the transformation of the mineral P-phases to calcium alkali phosphates was not complete. This was observed although the amount of Na2SO4 additive was dosed according to the results of the pre-investigations. Structure analysis by XRD showed that besides the target compound CaNaSO4 also some Ca3(PO4)2 remained in the SSA as well as some unreacted Na2SO4 additive. Obviously, the conditions in the industrial rotary kiln were not optimal for the process showing that some process aspects have to be reconsidered for the scale-up. T2 - IPW8 - 8th International Phosphorus Workshop CY - Rostock, Germany DA - 12.09.2016 KW - Sewage sludge ash KW - Thermochemical treatment KW - Phosphorus recovery PY - 2016 AN - OPUS4-37375 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Vogel, Christian A1 - Krüger, Oliver A1 - Adam, Christian T1 - Thermochemical treatment of sewage sludge ash with sodium additives under reducing conditions analyzed by thermogravimetry N2 - Phosphorus (P) for fertilizer use can be recovered from sewage sludge ash (SSA). To enhance the bioavailability of P and reduce the heavy metal content of SSA, it can be treated thermochemically with Na2CO3 or Na2SO4 at 950 °C in a rotary kiln using dry sewage sludge or lignite as reducing agent. These processes were investigated by thermogravimetry/differential thermal analysis coupled with gas analysis. Reducing conditions in this experimental setup were provided by 2 % hydrogen in the Ar carrier gas. During SSA + Na2CO3 treatment CO2, CO and water were detected in the off-gas. During SSA + Na2SO4 treatment SO2, some CO2 and water were detected. Heavy metal removal was more efficient for SSA + Na2CO3 compared to the sulfate variant. A SSA + Na2SO4 + lignite variant which also formed CO shifted the heavy metal removal to the results obtained with Na2CO3 which was obviously due to the additional reduction potential. However, Zn evaporation was not achieved with the Na2SO4 variants which were most probably due to immobilization as ZnS. KW - Phosphorus recovery KW - Thermochemical treatment KW - Sewage sludge ash KW - Reducing conditions KW - Heavy metal evaporation KW - FT-IR gas analysis PY - 2016 DO - https://doi.org/10.1007/s10973-015-5016-z SN - 1388-6150 SN - 1418-2874 SN - 0368-4466 SN - 1572-8943 VL - 123 IS - 2 SP - 1045 EP - 1051 PB - Springer CY - Dordrecht AN - OPUS4-34556 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schmidt, Wolfram A1 - Weba, Luciana A1 - Silbernagl, Dorothee A1 - Mota Gassó, Berta A1 - Höhne, Patrick A1 - Sturm, Heinz A1 - Pauli, Jutta A1 - Resch-Genger, Ute A1 - Steinborn, Gabriele ED - Khayat, Kamal Henry T1 - Influences of nano effects on the flow phenomena of self-compacting concrete N2 - Chemical admixtures like superplasticisers or stabilising agents are of ever increasing importance for modern concrete technology. They liberate the workability of concrete from its dependency on water content, and thus, open the gate towards innovative and future oriented concrete technologies such as selfcompacting concrete. Meanwhile admixtures have become common practice in concrete technology, but the understanding of these highly complex polymers in the entire concrete system lags far behind their application. Due to its complex time-dependent, multi-phase and multi-scale behaviour, flowable concrete systems are highly complicated and cannot be described comprehensively by simple models. It is therefore extremely challenging to identify the relevant parameters that predominantly control flow phenomena on different size scales, since these may occur on any scale between the nano scale (e.g. superplasticizer adsorption) and macro scale (e.g. grading of the aggregates). The present study discusses fundamental mechanisms at the interface between particle or hydrate surfaces and the fluid phase at a very early stage of concrete formation, and links these effects to macroscopic flow phenomena. Methods are discussed that appear promising interdisciplinary tools for enhancement of the understanding of the relevant interactions that are responsible for the macroscopic flow of flowable concrete. T2 - 8th International RILEM Symposium on Self-Compacting Concrete CY - Washington, D.C., USA DA - 15.05.2016 KW - Adsorption KW - Analytics KW - Hydration KW - Polycarboxylate ether KW - Rheology PY - 2016 SP - 245 EP - 254 AN - OPUS4-36882 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Fankhänel, J. A1 - Silbernagl, Dorothee A1 - Ghasem Zadeh Khorasani, Media A1 - Daum, B. A1 - Kempe, A. A1 - Sturm, Heinz A1 - Rolfes, R. T1 - Mechanical properties of Boehmite evaluated by Atomic Force Microscopy experiments and Molecular Dynamic Finite Element simulations N2 - Boehmite nanoparticles show great potential in improving mechanical properties of fiber reinforced polymers. In order to predict the properties of nanocomposites, knowledge about the material parameters of the constituent phases, including the boehmite particles, is crucial. In this study, the mechanical behavior of boehmite is investigated using Atomic Force Microscopy (AFM) experiments and Molecular Dynamic Finite Element Method (MDFEM) simulations. Young’s modulus of the perfect crystalline boehmite nanoparticles is derived from numerical AFM simulations. Results of AFM experiments on boehmite nanoparticles deviate significantly. Possible causes are identified by experiments on complementary types of boehmite, that is, geological and hydrothermally synthesized samples, and further simulations of imperfect crystals and combined boehmite/epoxy models. Under certain circumstances, the mechanical behavior of boehmite was found to be dominated by inelastic effects that are discussed in detail in the present work.The studies are substantiated with accompanying X-ray diffraction and Raman experiments. KW - AFM KW - MDFEM KW - Nanocomposite KW - Epoxy KW - X-ray diffraction KW - Raman spectroscopy KW - Young’s modulus KW - Slippage of weakly linked layers PY - 2016 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-384230 UR - https://www.hindawi.com/journals/jnm/2016/5017213/#B26 DO - https://doi.org/10.1155/2016/5017213 VL - 2016 IS - Article ID 5017213 SP - 1 EP - 13 PB - Hindawi Publishing Corporation AN - OPUS4-38423 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Ostermann, Markus A1 - Herzel, Hannes A1 - Kühn, A. A1 - Mory, D. A1 - Wedell, R. T1 - Prozessanalytik mit Online-RFA und Online-LIBS für die Regelung der Aufarbeitung von Klärschlammaschen T1 - Online Process Analytics with XRF and LIBS for the Control of the Recycling of Sewage Sludge Ashes N2 - Es wurde ein Online-Analysenverfahren zur Bestimmung von Elementgehalten in Klär-schlammaschen und deren Produkten aus einem thermochemischen Verfahren entwickelt. Durch das thermochemische Verfahren können Wertstoffe aus den Aschen wieder für die Kreislaufwirtschaft nutzbar gemacht und Schadstoffe sicher entfernt werden. Das Analysensystem ist eine Methodenkombination von Online-Laser induzierter Plasma Spektroskopie (LIBS) und Online-Röntgenfluoreszenzanalyse (RFA). Robustheit und modulare Bauweise des Verfahrens sind wichtige Anforderungen um auch für andere Anwendungen nutzbar zu sein. N2 - An online analysis method has been developed for the determination of element mass fractions in sewage sludge ashes and their products originating from a thermochemical process. Within this process resources from the sewage sludge ashes can be re-utilized for the recycling economy and pollutants can be removed. The applied analysis system is a method combination of Online-laser induced breakdown spectroscopy (LIBS) and online- X-ray fluorescence (XRF). Robustness and a modular construction are important demands for successful future applications. KW - Klärschlammasche KW - Phosphor KW - Prozessanalytik KW - Röntgenfluoreszenzanalyse KW - LIBS PY - 2016 DO - https://doi.org/10.1002/cite.201500186 SN - 1522-2640 VL - 88 IS - 6 SP - 786 EP - 792 PB - Wiley-VCH Verlag GmbH & Co. KGaA CY - Weinheim, Germany AN - OPUS4-36334 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Herzel, Hannes A1 - Krüger, Oliver A1 - Hermann, L. A1 - Adam, Christian T1 - Sewage sludge ash - A promising secondary phosphorus source for fertilizer production N2 - Sewage sludge incineration is extensively practiced in some European countries such as the Netherlands, Switzerland, Austria and Germany. A survey of German sewage sludge ash showed that the recovery potential is high, approx. 19,000 t of phosphorus per year. However, the survey also discovered that the bioavailability of phosphorus in the sewage sludge ash is poor and that more than half of the ashes cannot be used as fertilizers due to high heavy metal content. A new thermochemical process for sewage sludge ash treatment was developed that transforms the ash into marketable fertilizer products. Sewage sludge ash was thermochemically treated with sodium and potassium additives under reducing conditions, whereby the phosphate-bearing mineral phases were transformed into plant available phosphates. High P-bioavailability was achieved with a molar Na/P ratio > 1.75 in the starting materials. Sodium sulfate, carbonate and hydroxide performed comparably as additives for this calcination process. Potassium carbonate and -hydroxide have to be added in a molar K/P ratio > 2.5 to achieve comparable P-solubility. The findings of the laboratory scale investigations were confirmed by an industrial demonstration trial for an ash treatment with sodium sulfate. Simultaneously, the volatile transition metal arsenic (61% removal) as well as volatile heavy metals such as cadmium (80%), mercury (68%), lead (39%) and zinc (9%) were removed via the off-gas treatment system. The product of the demonstration trial is characterized by high bioavailability and a toxic trace element mass fraction below the limit values of the German fertilizer ordinance, thus fulfilling the quality parameters for a P-fertilizer. KW - Sewage sludge ash KW - Phosphorus recovery KW - Thermochemical treatment KW - Reducing conditions KW - Heavy metal evaporation KW - Bioavailability KW - Sodium sulfate PY - 2016 DO - https://doi.org/10.1016/j.scitotenv.2015.08.059 SN - 0048-9697 SN - 1879-1026 IS - 542 SP - 1136 EP - 1143 PB - Elsevier CY - Amsterdam AN - OPUS4-34165 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schönhals, Andreas A1 - Madkour, Sherif A1 - Yin, Huajie A1 - Szymoniak, Paulina T1 - Behavior of Ultra-Thin Films of Blends of Polystyrene/ Poly(vinyl methyl ether) by Nanosized Relaxation Spectroscopy N2 - In the course of miniaturizing modern technology down to the molecular scale, understanding the materials behavior has to be investigated and deviations from the bulk that might arises from confinement effects has to be understood. Here, a combination of nano-sized relaxation spectroscopies (Broadband dielectric spectroscopy (BDS) and Specific heat spectroscopy (SHS); employing AC nanochip calorimetry) were utilized to investigate the glassy dynamics of ultra-thin films of blends of Poly (vinyl methyl ether) (PVME) / Polystyrene (PS) 50:50 wt-%, which are miscible bulk (thicknesses: 8nm - 200nm, film thickness was controlled by ellipsometry, film topography by AFM). Both methods are sensitive to different probes; where SHS senses entropy fluctuations while BDS measures dipole fluctuations. For BDS measurements, a recently developed nano-structured electrode sample arrangement is employed; where ultra-thin films are spin-coated on an ultra-flat highly conductive silicon wafer, sandwiched between a wafer with nanostructured SiO2 nano-spacers with heights between 35 nm and 70 nm. The method was applied for film thicknesses up to 50 nm. For thicker films, the samples were prepared between crossed electrodes. It was proven that, for 50 nm films, both contact methods will lead to identical results. By measuring the dynamic Tg in dependence of the film thickness, SHS showed that the Tg of the whole film was strongly influenced by a nanometer-thick surface layer at the polymer/air interface due to a self-assembling process [1]. The dynamic Tg obtained from the SHS measurements decrease with decreasing film thickness, evidencing the importance of a mobile surface layer at the polymer/air interface for the glass transition of the whole film. Compared to the SHS results, the BDS measurements show a completely different behavior. At high temperatures, the temperature dependence of the relaxation times of the films follows that of bulk-like PS/PVME; obeying the VFT-law. With decreasing temperature, the temperature dependence deviates from the VFT to an Arrhenius law; where the apparent activation energy decreases with decreasing film thickness. This is the first example where confinement induced changes were observed by BDS for ultra-thin films. All results were analyzed in details in a comprehensive discussion. T2 - 9th International Conference on Broadband Dielectric Spectroscopy and its Applications CY - Pisa, Italy DA - 11.09.2016 KW - Ultra-Thin films KW - Broadband Dielectric Spectrscopy KW - Nanostructured Electrodes PY - 2016 AN - OPUS4-37387 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Adam, Christian A1 - Herzel, Hannes T1 - Recycling of nutrients from biomass ashes N2 - Recycling of nutrients from biomass ashes can safe natural recources and improve agricultural Efficiency. This was shown in the presentation for sewage sludge ashes, chicken manure ash and for sugar cane plants. T2 - 6° Enconto Brasileiro-Alemao para Producao Sustentavel no Cerrado CY - Goiania, Brazil DA - 19.09.2016 KW - Nutrient recovery PY - 2016 AN - OPUS4-37599 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Madkour, Sherif A1 - Szymoniak, Paulina A1 - Schönhals, Andreas T1 - Dielectric and thermal relaxation behavior of ultra-thin films of poly(vinyl methyl ether) – evidence of an adsorbed layer N2 - Despite the many controversial discussions about the nanometric confinement effect on the properties of ultra-thin films, much remain not understood and/or experimentally unproven. Here, a combination of Broadband Dielectric Spectroscopy (BDS) and Specific Heat Spectroscopy (SHS) employing AC nanochip calorimetry were utilized to investigate the glassy dynamics of ultra-thin films of a low MW Poly (vinyl methyl ether) (PVME) (thicknesses: 7 nm – 160 nm). For BDS measurements, a recently developed nano-structured electrode sample arrangement is employed; where ultra-thin films are spin-coated on an ultra-flat highly conductive silicon wafer, sandwiched between a wafer with nanostructured SiO2 nano-spacers with heights between 35 nm and 70 nm. For films with thicknesses up to 50 nm, BDS measurements showed two relaxation processes, which can be analyzed for these film thicknesses in details. The process located at higher frequencies coincidence in both, its position and temperature dependence, with the -relaxation of bulk PVME and is therefore assigned to the -relaxation of a bulk-like layer. The temperature dependence of the relaxation rate of this process in independent of film thickness. This is further confirmed by the SHS investigations, which superimpose in its temperature dependence with the BDS results; independent of film thickness. The second process is located at lower frequencies, where it shows a different temperature dependence and ascribed to the relaxation of polymer segments adsorbed at the substrate. The interaction of PVME with SiO2 was further confirmed by contact angle investigations. This adsorbed layer further undergoes a confinement effect that results in a lower Vogel temperature than that of the bulk-like layer. A detailed analysis of the dielectric strengths of both processes reveals that the thickness of the adsorbed layer decreases with increasing temperature, while that of the bulk-like layer increases. As a main conclusion, BDS showed that the glassy dynamics of the bulk-like and the adsorbed layer are thickness independent, which is in agreement with the SHS results. To our knowledge, this is the first probing of the segmental dynamics of an adsorbed layer in ultrathin films. T2 - 9th International Conference on Broadband Dielectric Spectroscopy and its Applications CY - Pisa, Italy DA - 11.09.2016 KW - Ultra-thin films KW - Broadband dielectric spectroscopy KW - Specific heat spectroscopy PY - 2016 AN - OPUS4-37528 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Madkour, Sherif A1 - Szymoniak, Paulina A1 - Schönhals, Andreas T1 - Evidence of a three-layred structure in ultrathin PVME and PVME-PS blend films by nanosized relaxation spectroscopy N2 - In the course of miniaturizing modern technology down to the molecular scale, much remain unknown about the materials behavior and the deviations from the bulk that might arises from confinement effects. Here, a combination of nano-sized relaxation spectroscopies (Broadband dielectric spectroscopy (BDS) and Specific heat spectroscopy (SHS); employing AC nanochip calorimetry) were utilized to investigate the glassy dynamics of ultra-thin films of Poly (vinyl methyl ether) (PVME) and of blends PVME / Polystyrene (PS) 50:50 wt-%,, which are miscible in bulk (thicknesses: ca. 8 nm – 160 nm, film thickness was controlled by ellipsometry, film topography by AFM). Both methods are sensitive to different probes; where SHS senses entropy fluctuations while BDS measures dipole fluctuations. For BDS measurements, a recently developed nano-structured electrode sample arrangement is employed, where ultra-thin films are spin-coated on an ultra-flat highly conductive silicon wafer, sandwiched between a wafer with nanostructured SiO2 nano-spacers with heights between 35 nm and 70 nm. For PVME films, two thickness independent processes were observed and interpreted to be the α-processes of a bulk-like layer and a process due to an absorbed layer to the substrate. This adsorbed layer further undergoes a confinement effect that results in the localization of the segmental dynamics, which results in an Arrhenius-like temperature dependence. A detailed analysis of the dielectric strengths of both processes reveals that the thickness of the adsorbed layer decreases with increasing temperature, while that of the bulk-like layer increases. For the blend system, by measuring the dynamic Tg in dependence of the film thickness, SHS showed that the Tg of the whole film was strongly influenced by a nanometer-thick surface layer at the polymer/air interface due to a self-assembling process. The dynamic Tg obtained from the SHS measurements decreased with decreasing film thickness. On the other hand, BDS measurements showed a completely different behavior. At high temperatures, the temperature dependence of the relaxation times of the films follows that of bulk-like PS/PVME; obeying the VFT-law. With decreasing temperature, the temperature dependence deviates from the VFT to an Arrhenius law; where the apparent activation energy decreases with decreasing film thickness. This is the first example where confinement induced changes were observed by BDS for ultra-thin films. All results were analyzed in detail in a comprehensive discussion. T2 - Polydays 2016 CY - Potsdam, Germany DA - 28.09.2016 KW - Ultra-Thin films PY - 2016 AN - OPUS4-38188 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Okkenhaug, G. A1 - Gebhardt, K.-A. G. A1 - Amstaetter, K. A1 - Bue, H. L. A1 - Herzel, Hannes A1 - Mariussen, E. A1 - Almås, Å. R. A1 - Cornelissen, G. A1 - Breedveld, G. D. A1 - Rasmussen, G. A1 - Mulder, J. T1 - Antimony (Sb) and lead (Pb) in contaminated shooting range soils: Sb and Pb mobility and immobilization by iron based sorbents, a field study N2 - Small-arm shooting ranges often receive a significant input of lead (Pb), copper (Cu) and antimony (Sb) from ammunition. The goal of the present study was to investigate the mobility, distribution and speciation of Pb and Sb pollution under field conditions in both untreated and sorbent-amended shooting range soil. Elevated Sb (19–349 μg L⁻¹) and Pb (7–1495 μg Pb L⁻¹) concentrations in the porewater of untreated soil over the four-year test period indicated a long-term Sb and Pb source to the adjacent environment in the absence of remedial measures. Mixing ferric oxyhydroxide powder (CFH-12) (2%) together with limestone (1%) into the soil resulted in an average decrease of Sb and Pb porewater concentrations of 66% and 97%, respectively. A similar reduction was achieved by adding 2% zerovalent iron (Fe°) to the soil. The remediation effect was stable over the four-year experimental period indicating no remobilization. Water- and 1 M NH₄NO₃-extractable levels of Sb and Pb in field soil samples indicated significant immobilization by both treatments (89–90% for Sb and 89–99% for Pb). Results from sequential extraction analysis indicate fixation of Sb and Pb in less accessible fractions like amorphous iron oxides or even more crystalline and residual mineral phases, respectively. This work shows that amendment with Fe-based sorbents can be an effective method to reduce the mobility of metals both in cationic and anionic form in polluted shooting range soil. KW - Shooting range soil KW - Antimony KW - Lead KW - Soil amendment KW - Porewater KW - Field test PY - 2016 DO - https://doi.org/10.1016/j.jhazmat.2016.01.005 SN - 0304-3894 VL - 307 SP - 336 EP - 343 PB - Elsevier Science CY - Amsterdam, Netherlands AN - OPUS4-36109 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Madkour, Sherif A1 - Szymoniak, Paulina A1 - Heidari, Mojdeh A1 - von Klitzing, Regine A1 - Schönhals, Andreas T1 - Evidence of a three-layered structure in ultra-thin PVME and PVME/PS blend films by nano-sized relaxation spectroscopy N2 - Despite the many controversial discussions about the nanometric confinement effect and the predictions of the three-layer model, much remain not understood and/or experimentally unproven. Here, a combination of Broadband Dielectric Spectroscopy (BDS), Specific Heat Spectroscopy (SHS), and ellipsometry was utilized to investigate the glassy dynamics of ultra-thin films of Poly (vinyl methyl ether) (PVME) and PVME/Polystyrene (PS) 50:50 wt-% miscible blend (thicknesses: 8nm - 200nm). For BDS measurements, a recently developed nano-structured sample arrangement; where ultra-thin films are spin-coated on an ultra-flat highly conductive silicon wafer and sandwiched between a wafer with nanostructured silica nano-spacers, was used. For PVME films, two processes were observed and interpreted to be the α-processes of a bulk-like layer and an absorbed layer to the substrate. BDS and SHS showed that glassy dynamics are bulk-like. However, for films lower than 15nm, BDS showed weakly slowed dynamics. For PVME/PS blend, by a self-assembling process, a nanometer-thin surface layer with a higher molecular mobility is formed at the polymer/air interface. By measuring the dynamic Tg in dependence on the film thickness, both BDS and SHS, showed that the Tg of the whole film was strongly influenced by that nanometer thick surface layer, with a lower Tg. T2 - 80. Jahrestagung der DPG und DPG-Frühjahrstagung CY - Regensburg DA - 06.03.2016 KW - Ultra-thin films PY - 2016 AN - OPUS4-35540 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Madkour, Sherif A1 - Szymoniak, Paulina A1 - Schönhals, Andreas T1 - Evidence of a Three-Layred Structure in Ultrathin PVME and PVME-PS Blend Films by Nanosized Relaxation Spectroscopy N2 - In the course of miniaturizing modern technology down to the molecular scale, much remain unknown about the materials behavior and the deviations from the bulk that might arises from confinement effects. Here, a combination of nano-sized relaxation spectroscopies (Broadband dielectric spectroscopy (BDS) and Specific heat spectroscopy (SHS); employing AC nanochip calorimetry) were utilized to investigate the glassy dynamics of ultra-thin films of Poly (vinyl methyl ether) (PVME) and of blends PVME / Polystyrene (PS) 50:50 wt-%,, which are miscible in bulk (thicknesses: ca. 8 nm – 160 nm, film thickness was controlled by ellipsometry, film topography by AFM). Both methods are sensitive to different probes; where SHS senses entropy fluctuations while BDS measures dipole fluctuations. For BDS measurements, a recently developed nano-structured electrode sample arrangement is employed, where ultra-thin films are spin-coated on an ultra-flat highly conductive silicon wafer, sandwiched between a wafer with nanostructured SiO2 nano-spacers with heights between 35 nm and 70 nm. For PVME films, two thickness independent processes were observed and interpreted to be the α-processes of a bulk-like layer and a process due to an absorbed layer to the substrate. This adsorbed layer further undergoes a confinement effect that results in the localization of the segmental dynamics, which results in an Arrhenius-like temperature dependence. A detailed analysis of the dielectric strengths of both processes reveals that the thickness of the adsorbed layer decreases with increasing temperature, while that of the bulk-like layer increases. For the blend system, by measuring the dynamic Tg in dependence of the film thickness, SHS showed that the Tg of the whole film was strongly influenced by a nanometer-thick surface layer at the polymer/air interface due to a self-assembling process. The dynamic Tg obtained from the SHS measurements decreased with decreasing film thickness. On the other hand, BDS measurements showed a completely different behavior. At high temperatures, the temperature dependence of the relaxation times of the films follows that of bulk-like PS/PVME; obeying the VFT-law. With decreasing temperature, the temperature dependence deviates from the VFT to an Arrhenius law; where the apparent activation energy decreases with decreasing film thickness. This is the first example where confinement induced changes were observed by BDS for ultra-thin films. All results were analyzed in detail in a comprehensive discussion. T2 - 14. Lähnwitzseminar on Calorimetry CY - Rostock-Warnemünde, Germany DA - 05.05.2016 KW - Ultra-Thin films PY - 2016 AN - OPUS4-36477 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wunderle, B. A1 - Onken, T. A1 - Heilmann, J. A1 - Silbernagl, Dorothee A1 - Arnold, J. A1 - Bieniek, T. A1 - Pufall, R. T1 - Reliability of sputtered thin aluminium films under accelerated stress testing by vibration loading and modeling N2 - Aluminium is still one of the most important contact metallisations for power electronic chips like MOSFETs or IGBTs. With a large difference in thermal expansion coefficients (CTEs) between aluminium and silicon and the temperatures generated in hot-spots during high power transients, these layers are prone to failure due to thermo-mechanical fatigue. Usually lifetime assessment is done by subjecting dedicated test specimens to standardised stress tests as e.g. active or passive thermal cycling. This paper proposes a novel method for accelerated stress testing and lifetime modelling of thin aluminium films in the high-cycle fatigue regime by isothermal mechanical loading. The proposed novel test method is suggested to complement or replace resource-demanding thermal cycling tests and allow simple in-situ monitoring of failure. T2 - 6th Electronic System-Integration Technology Conference (ESTC) CY - Grenoble, France DA - 13.09.2016 KW - Semiconductor device reliability KW - Thermal expansion KW - AFM KW - Vibrations KW - Nanoroughness KW - Accelerated stress testing KW - Active thermal cycling KW - Power electronic chips KW - Sputtered thin aluminium film KW - Thermomechanical fatigue PY - 2016 DO - https://doi.org/10.1109/ESTC.2016.7764458 SP - 1 EP - 14 PB - IEEE AN - OPUS4-43595 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Mieller, Björn A1 - Vogl, Jochen A1 - Noordmann, J. A1 - Kaltenbach, A. A1 - Rienitz, O. T1 - Preparation and characterization of primary magnesium mixtures for the ab initio calibration of absolute magnesium isotope ratio measurements N2 - We report an appropriate preparation of binary isotope calibration mixtures of the three stable isotopes of magnesium to be used in the ab initio calibration of multicollector mass spectrometers (ICPMS and TIMS). For each of the three possible combinations of binary mixtures ("24Mg" + "25Mg", "24Mg" + "26Mg", and "25Mg" + "26Mg"), three individual setups have been prepared under gravimetric control, each of them with an isotope ratio close to unity, and a total magnesium mass fraction close to 20 mg kg-1. The preparation was designed to occur via an intermediate dilution of a parent solution of a highly purified specimen of the isotopically enriched magnesium materials. For the application as calibration mixtures, a complete uncertainty budget was set up, and is presented and discussed in detail, including the aspects that went into the design of the dilution and mixing approach to minimize uncertainty. The principle parameters for the purpose of the later calibration of the mass spectrometers are the absolute masses of isotopically enriched magnesium materials in the primary calibration mixtures. For the first time relative expanded uncertainties U (k = 2) for these masses of ≤0.005% could be achieved for all mixtures. KW - Atomic weight KW - Magnesium KW - Isotope mixture KW - Purity PY - 2016 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-352564 DO - https://doi.org/10.1039/c5ja00284b SN - 0267-9477 SN - 1364-5544 N1 - Geburtsname von Mieller, Björn: Brandt, B. - Birth name of Mieller, Björn: Brandt, B. N1 - Corrigendum: Journal of analytical atomic spectrometry 34 (2019) 2340 VL - 31 IS - 1 SP - 179 EP - 196 PB - Royal Society of Chemistry CY - London AN - OPUS4-35256 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Vogl, Jochen A1 - Mieller, Björn A1 - Noordmann, J. A1 - Rienitz, O. A1 - Malinovskiy, D. T1 - Characterization of a series of absolute isotope reference materials for magnesium: ab initio calibration of the mass spectrometers, and determination of isotopic compositions and relative atomic weights N2 - For the first time, an ab initio calibration for absolute Mg isotope ratios was carried out, without making any a priori assumptions. All quantities influencing the calibration such as the purity of the enriched isotopes or liquid and solid densities were carefully analysed and their associated uncertainties were considered. A second unique aspect was the preparation of three sets of calibration solutions, which were applied to calibrate three multicollector ICPMS instruments by quantifying the correction factors for instrumental mass discrimination. Those fully calibrated mass spectrometers were then used to determine the absolute Mg isotope ratios in three candidate European Reference Materials (ERM)-AE143, -AE144 and -AE145, with ERM-AE143 becoming the new primary isotopic reference material for absolute isotope ratio and delta measurements. The isotope amount ratios of ERM-AE143 are n(25Mg)/n(24Mg) = 0.126590(20) mol/mol and n(26Mg)/n(24Mg) = 0.139362(43) mol/mol, with the resulting isotope amount fractions of x(24Mg) = 0.789920(46) mol/mol, x(25Mg) = 0.099996(14) mol/ mol and x(26Mg) = 0.110085(28) mol/mol and an atomic weight of Ar(Mg) = 24.305017(73); all uncertainties were stated for k = 2. This isotopic composition is identical within uncertainties to those stated on the NIST SRM 980 certificate. The candidate materials ERM-AE144 and -AE145 are isotopically lighter than ERM-AE143 by 1.6 ‰ and 1.3 ‰, respectively, concerning their n(26Mg)/n(24Mg) ratio. The relative combined standard uncertainties are ≤0.1 ‰ for the isotope ratio n(25Mg)/n(24Mg) and ≤0.15 ‰ for the isotope ratio n(26Mg)/ n(24Mg). In addition to characterizing the new isotopic reference materials, it was demonstrated that commonly used fractionation laws are invalid for correcting Mg isotope ratios in multicollector ICPMS as they result in a bias which is not covered by its associated uncertainty. Depending on their type, fractionation laws create a bias up to several per mil, with the exponential law showing the smallest bias between 0.1 ‰ and 0.7 ‰. KW - isotope reference material KW - absolute measurements KW - mass spectrometry KW - atomic weight KW - magnesium PY - 2016 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-370931 DO - https://doi.org/10.1039/C6JA00013D SN - 0267-9477 N1 - Geburtsname von Mieller, Björn: Brandt, B. - Birth name of Mieller, Björn: Brandt, B. VL - 31 IS - 7 SP - 1440 EP - 1458 PB - Royal Society of Chemistry CY - Cambridge, UK AN - OPUS4-37093 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Frasca, Daniele A1 - Schulze, Dietmar A1 - Wachtendorf, Volker A1 - Krafft, Bernd A1 - Rybak, Thomas A1 - Schartel, Bernhard T1 - Multilayer Graphene/Carbon Black/Chlorine Isobutyl Isoprene Rubber Nanocomposites N2 - High loadings of carbon black (CB) are usually used to achieve the properties demanded of rubber compounds. In recent years, distinct nanoparticles have been investigated to replace CB in whole or in part, in order to reduce the necessary filler content or to improve performance. Multilayer graphene (MLG) is a nanoparticle made of just 10 graphene sheets and has recently become commercially available for mass-product nanocomposites. Three phr (part for hundred rubbers) of MLG are added to chlorine isobutyl isoprene rubber (CIIR)/CB composites in order to replace part of the CB. The incorporation of just 3 phr MLG triples the Young’s modulus of CIIR; the same effect is obtained with 20 phr CB. The simultaneous presence of three MLG and CB also delivers remarkable properties, e.g. adding three MLG and 20 phr CB increased the hardness as much as adding 40 phr CB. A comprehensive study is presented, showing the influence on a variety of mechanical properties. The potential of the MLG/CB combination is illustrated to reduce the filler content or to boost performance, respectively. Apart from the remarkable mechanical properties, the CIIR/CB/MLG nanocomposites showed an increase in weathering resistance. KW - nanocomposites KW - rubber KW - multilayer graphene KW - carbon black PY - 2016 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-358569 DO - https://doi.org/10.3390/polym8030095 SN - 2073-4360 VL - 8 SP - 95 PB - MDPI CY - Basel, Switzerland AN - OPUS4-35856 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kühn, A. A1 - Wedell, R. A1 - Ostermann, Markus A1 - Adam, Christian A1 - Herzel, Hannes A1 - Mory, D. T1 - Analytische Verfahren zur On-Line-Bestimmung von Elemementkonzentrationen in Pulvern und Aschen N2 - Die Aufbereitung kommunaler Abwässer leistet einen wichtigen Beitrag zum Schutz der Umwelt und der Reinhaltung der Gewässer. Im Zuge der Abwasserreinigung entstehen deutschlandweit jährlich ca. 2,4 Millionen Tonnen Klärschlamm. Diese Massen stellen für die Anlagenbetreiber oft eine Herausforderung bei der Entsorgung dar. Es sind jedoch neben zahllosen Schadstoffen auch anorganische Wert- und Nährstoffe enthalten deren Nutzung zunehmend attraktiv wird. Ein essenzieller und in Lagerstätten begrenzt vorhandener Nährstoff ist Phosphor. Dieser ist in Klärschlämmen enthalten und erreicht in Klärschlammaschen Konzentrationen von bis zu 10 %. Eine Verwertung als Düngemittel in der Landwirtschaft ist jedoch nur für schadstoffarme Materiale mit guter Pflanzenverfügbarkeit der Nährstoffe zulässig. Für die Aufbereitung von Klärschlämmen und Schadstoffentfrachtung von Klärschlammaschen existieren verschiedene technologische Ansätze. Für jeden Prozess ist eine analytische Überwachung der Nährstoffwerte sowie der Schadstoffgrenzwerte erforderlich. Im Vortrag werden die Ergebnisse eines Projektes zur on-line Analytik thermisch aufbereiteter Klärschlammaschen vorgestellt. Es werden die Methoden der Röntgenfluoreszenz (RFA) und der Laserplasmaspektroskopie (LIBS) parallel angewendet und verglichen. T2 - 20th Leibniz-Conference of advanced Science - Recycling CY - Lichtenwalde, Sachsen, Germany DA - 19.05.2016 KW - Klärschlammasche KW - Elementanalytik KW - RFA KW - LIBS PY - 2016 AN - OPUS4-36426 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Schartel, Bernhard A1 - Perret, Birgit A1 - Dittrich, Bettina A1 - Ciesielski, M. A1 - Krämer, J. A1 - Müller, P. A1 - Altstädt, V. A1 - Zang, L. A1 - Döring, M. T1 - Flame retardancy of polymers: the role of specific reactions in the condensed phase N2 - Condensed-phase mechanisms play a major role in fire-retardant polymers. Generations of development have followed the concept of charring to improve fire properties. Whereas the principal reactions are believed to be known, the specific description for multicomponent systems is lacking, as is the picture across different systems. A two-step approach is proposed in general, and also presented in greater detail. The second step covers the specific reactions controlling charring, whereas the actual reactants are provided in the preceding step. This model consistently incorporates the variety of structure–property relationships reported. A comprehensive case study is presented on seven phosphorus flame retardants in two epoxy resins to breathe life into the two-step approach. KW - Charring KW - Epoxy KW - Flame retardancy KW - Pyrolysis KW - Thermogravimetric analysis (TGA) PY - 2016 DO - https://doi.org/10.1002/mame.201500250 SN - 1438-7492 SN - 1439-2054 VL - 301 IS - 1 SP - 9 EP - 35 PB - Wiley-VCH Verl. CY - Weinheim AN - OPUS4-35273 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Pappalardo, Salvatore A1 - Russo, Pietro A1 - Acierno, Domenico A1 - Rabe, Sebastian A1 - Schartel, Bernhard T1 - The synergistic effect of organically modified sepiolite in intumescent flame retardant polypropylene N2 - The pyrolysis, flammability and fire behavior of polypropylene (PP) containing an intumescent flame retardant and sepiolite nanoparticles were investigated by performing thermogravimetry, oxygen index (LOI), UL-94, and cone calorimeter tests. The combination of 0.5 wt% of premodified sepiolite (OSEP) with 12 wt% of a commercial intumescent flame retardant showed a clear synergy in LOI, UL-94 ranking and peak heat release rate. The ternary formulation achieved a V-0 classification and, consequently, allowed a reduction in the amount of flame retardant necessary to achieve this result. Whereas OSEP and pristine sepiolite nanoparticles (SEP) affect the performance in PP nanocomposites quite similarly, OSEP outperformed SEP in the combination with intumescent flame retardant. The cone calorimeter results and dynamic rheological measurements confirmed the synergistic effect between the nanofiller and the flame retardant resulting from the improved properties of the residual protective layer. KW - Polypropylene KW - Intumescent flame retardant KW - Sepiolite KW - Cone calorimetry KW - Low oxygen index PY - 2016 DO - https://doi.org/10.1016/j.eurpolymj.2016.01.041 SN - 0014-3057 VL - 76 SP - 196 EP - 207 PB - Elsevier AN - OPUS4-35854 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Müller, Patrick A1 - Schartel, Bernhard T1 - Melamine poly(metal phosphates) as flame retardant in epoxy resin: Performance, modes of action, and synergy N2 - Melamine poly(metal phosphates) (MPMeP) are halogen-free flame retardants commercialized under the brand Name Safire. Melamine poly(aluminum phosphate) (MPAlP), melamine poly(zinc phosphate) (MPZnP), and melamine poly(Magnesium phosphate) (MPMgP) were compared in an epoxy resin (EP). The thermal decomposition, flammability, burning behavior, and glass transition temperature were investigated using thermogravimetric analysis, pyrolysis combustion flow calorimeter, UL 94 testing, cone calorimeter, and differential scanning calorimetry. While the materials exhibited similarities in their pyrolysis, EP+MPZnP and EP+MPMgP showed better fire behavior than EP+MPAlP due to superior protective properties of the fire residues. Maintaining the 20 wt % loading, MPZnP was combined with various other flame retardants. A synergistic effect was evident for melamine polyphosphate (MPP), boehmite, and a derivative of 6H-Dibenzo[c,e][1,2]oxaphosphinine-6-oxide. The best overall performance was observed for EP+(MPZnP+MPP) because of the best protection effectiveness of the fire residue. EP +(MPZnP+MPP) achieved V1/V0 in UL 94, and an 80% reduction in the peak heat release rate. This study evaluates the efficiency of MPMeP in EP, alone and in combination with other flame retardants. MPMeP is a suitable flame retardant for epoxy resin, depending on its kind and synergists. KW - flame retardance KW - thermogravimetric analysis KW - thermosets PY - 2016 DO - https://doi.org/10.1002/APP.43549 SN - 0021-8995 SN - 1097-4628 VL - 133 IS - 24 SP - 43549 PB - Wiley AN - OPUS4-35855 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Hesse, J. A1 - Naghib-zadeh, H. A1 - Rabe, Torsten A1 - Töpfer, J. T1 - Integration of additive-free Ni–Cu–Zn ferrite layers into LTCC multilayer modules N2 - The sintering behavior of sub-micron Ni0.30Cu0.20Zn0.52Fe1.98O3.99 ferrite with and without Bi2O3 addition was studied. Ferrites with 0.5 wt% Bi2O3 exhibit enhanced shrinkage at T < 900 °C with significant grain growth. Additive-free ferrite powders also sinter to high density at 900 °C, however, grain growth is very limited. Both ferrites exhibit a permeability of µ = 400–450. Multilayers consisting of ferrite and low-k dielectric LTCC layers were prepared by co-firing at 900–915 °C. The shrinkage and thermal expansion characteristics of ferrite and LTCC tapes are similar. However, the permeability of integrated ferrite layers, made from ferrite tapes with Bi2O3 additive, significantly drops after co-firing with LTCC layers compared to separately fired monolithic ferrite multilayers. Contrarily, the permeability of integrated, Bi2O3-free ferrite layers, co-fired with dielectric tapes, is identical to that of monolithic ferrite multilayers. This finding is an important step toward ferrite integration into complex LTCC multilayer architectures. KW - LTCC KW - Ferrite integration KW - Multilayer KW - Sintering PY - 2016 DO - https://doi.org/10.1016/j.jeurceramsoc.2016.02.016 SN - 0955-2219 VL - 36 IS - 8 SP - 1931 EP - 1937 PB - Elsevier Ltd. CY - Oxford, UK AN - OPUS4-36001 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Resch-Genger, Ute A1 - Moser, Marko A1 - Kraft, Marco A1 - Würth, Christian A1 - Behnke, Thomas A1 - Falkenhagen, Jana A1 - Kaiser, Martin A1 - Muhr, V. A1 - Hirsch, T. T1 - Simple method for the quantification of PEG ligands and guidelines to the spectroscopic characterization of upconversion nanoparticles N2 - The surface modification of nanometer- and micrometer-sized particles with polyethylene glycol (PEG) ligands of varying length is a very common strategy to tune their hydrophilicity and biocompatibility, minimize unspecific interactions, improve biofunctionalization efficiencies, and enhance blood circulation times. Nevertheless, simple methods for the quantification of PEG ligands are rare. This is similarly true for the spectroscopic characterization of lanthanide-doped upconverting nanoparticles (UCNPs), novel near infrared (NIR)-excitable nonlinear fluorescence reporters for bioanalysis and theranostics, providing background-free multiple narrow emission bands in the visible and NIR, excellent photostability, and long luminescence lifetimes. We present here a simple method for the determination of the number of PEG ligands on nanomaterials and screening methods for the fast identification of nonradiative deaction pathways in UCNPs. T2 - SPIE Photonics West CY - San Francisco, CA, USA DA - 15.02.2016 KW - Optical assay KW - Fluorescence KW - Integrating sphere spectroscopy KW - Quantum yield KW - NIR KW - IR KW - Optical spectroscopy KW - Nanomaterials KW - Semiconducor nanocrystals KW - Upconversion nanocrystals KW - Surface analysis; KW - Ligand analysis PY - 2016 AN - OPUS4-35951 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Mieller, Björn T1 - Glass-ceramic composite multilayer structures - modeling of densification and shrinkage mismatch N2 - Low temperature co-fired ceramics (LTCC) are glass-ceramic composites that are processed by tape casting and multilayer technology to create multilayer circuit boards and electronic packages for high frequency applications, microsystems, and sensors. Pressure-assisted sintering (PAS) enables the densification of LTCC without lateral shrinkage, and thereby the manufacturing of miniaturized modules with minimal shrinkage tolerances. Co-firing of LTCC with other functional ceramics facilitates the implementation of innovative module concepts. The master sintering curve model is a useful tool to supplement the empirical optimization of such sintering processes. Two applications of the model are presented. Firstly, an algorithm is deduced that allows the simulation of shrinkage mismatch in a combined multilayer structure. Based on this simulation, an optimized process for the co-firing of LTCC and ferrite is derived. Secondly, the pressure-assisted sintering of LTCC is modeled. A comprehensive description of the densification behavior of LTCC during PAS is thereby possible. T2 - 14. Treffen des DGG-DKG Arbeitskreises "Glasig-kristalline Multifunktionswerkstoffe" CY - Berlin, Germany DA - 25.02.2016 KW - low temperature co-fired ceramics KW - master sintering curve KW - pressure-assisted sintering KW - multilayer PY - 2016 AN - OPUS4-35419 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Agudo Jácome, Leonardo T1 - Dislocation analysis in Ni-base superalloy single crystals N2 - The LEK94 is a Ni-base superalloy single crystal (SX) of the second generation, a materials class which is important for its high temperature creep resistance (>1000°C) in first stage blades of low-to-medium pressure gas turbines. Monocrystalline Ni-base superalloy SXs have a two-phase microstructure consisting of small cubes (' phase with the ordered L12 crystal structure, cube edge length: 500 nm), separated by thin channels (γ phase with fcc solid solution structure, channel width: 20 nm). The microstructural evolution during high temperature and low stress tensile creep has been thoroughly investigated previously, mainly for [001] loading, both in terms of dislocation activity (filling of γ channels, formation of dislocation networks, cutting of the γ’ phase) as well as phase coarsening (rafting, topological inversion). Other loading geometries have received less attention. The present work studies high temperature and low stress creep deformation of the superalloy LEK 94 at temperatures around 1000°C, where rafting occurs. Differences between loading under different uniaxial, biaxial and triaxial stress states are discussed. Stereo-microscopy and g∙b analysis in the scanning transmission electron microscopy mode (STEM) are combined for microstructural analysis. The focus is set on the role of dislocation interactions with the aging microstructure. Both development in STEM characterization methods, as well as the roles of phase coarsening, γ channel filling, microstructural heterogeneity and γ’ phase cutting are discussed. T2 - Eingeladener Vortrag CY - US Air Force Research Laboratories, Dayton, OH, USA DA - 19.07.2016 KW - Doslocation KW - Superalloy KW - Microscopy KW - Creep PY - 2016 AN - OPUS4-41945 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Frasca, Daniele A1 - Schulze, Dietmar A1 - Wachtendorf, Volker A1 - Morys, Michael A1 - Schartel, Bernhard T1 - Multilayer graphene/chlorine-isobutene-isoprene rubber nanocomposites: the effect of dispersion N2 - Multilayer graphene (MLG) is composed of approximately 10 sheets of graphene. It is a promising nanofiller just starting to become commercially available. The Dispersion of the nanofiller is essential to exploit the properties of the nanocomposites and is dependent on the preparation method. In this study, direct incorporation of 3 parts per hundred of rubber (phr) MLG into chlorine-isobutene- isoprene rubber (CIIR) on a two-roll mill did not result in substantial enhancement of the material properties. In contrast, by pre-mixing the MLG (3 phr) with CIIR using an ultrasonically assisted solution mixing procedure followed by two-roll milling, the properties (rheological, curing, and mechanical) were improved substantially compared with the MLG/CIIR nanocomposites mixed only on the mill. The Young’s moduli of the nanocomposites mixed in solution increased by 38%. The CIIR/MLG nanocomposites produced via solution showed superior durability against weathering exposure. KW - Multilayer graphene KW - Nanocomposite KW - Dispersion KW - Rubber PY - 2016 DO - https://doi.org/10.1002/pat.3740 SN - 1042-7147 SN - 1099-1581 VL - 27 IS - 7 SP - 872 EP - 881 PB - Wiley AN - OPUS4-36866 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Mieller, Björn A1 - Rabe, Torsten T1 - Hot-embossing of low temperature co-fired ceramics during pressure-assisted sintering N2 - A novel process to structure the surfaces of low temperature co-fired ceramics (LTCC) is presented. Lowered and raised structures are formed by hot-embossing with glass-like carbon molds during pressure-assisted sintering. Molding is driven by viscous flow of the LTCC glassy phase above the glass transition temperature. For accurate molding of embossments on the LTCC surface, proper filling of cavities in the glass-like carbon mold is necessary. Therefore, de-airing of the mold cavity has to be assured. Two strategies have been investigated: (i) hot-embossing at 850 °C after termination of LTCC shrinkage with de-airing through vent holes in the mold; and (ii) hot-embossing of open porous LTCC at 775 °C with dense molds, de-airing through pore channels in the LTCC, and subsequent densification by further heating to 850 °C. Circular embossments with 10 mm diameter were molded on a commercially available LTCC (Ceramtape GC, CeramTec GmbH, Marktredwitz, Germany). The sintered height was measured using optical profilometry. Image processing was used to evaluate porosity distributions in the sintered structures. The influence of embossing temperature on LTCC viscosity and mold filling behavior is discussed. Successful molding of 47 µm high raised grids and characters by hot embossing with 0.41 MPa at 775 °C and further heating to 850 °C under constant load is demonstrated. Thereby, the high potential of hot-embossing for precise structuring of LTCC surfaces is illustrated. T2 - 91. Jahrestagung der Deutschen Keramischen Gesellschaft CY - Freiberg DA - 07.03.2016 KW - Low temperature co-fired ceramics KW - Pressure-assisted sintering KW - Glass-like carbon KW - Structuring KW - Hot-embossing PY - 2016 N1 - Geburtsname von Mieller, Björn: Brandt, Björn Birth Name of Mieller, Björn: Brandt, Björn AN - OPUS4-35538 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Schartel, Bernhard A1 - Frasca, Daniele A1 - Schulze, Dietmar A1 - Wachtendorf, Volker A1 - Krafft, Bernd A1 - Morys, Michael A1 - Böhning, Martin A1 - Rybak, Thomas T1 - Multilayer graphene rubber nanocomposites N2 - Multilayer Graphene (MLG), a nanoparticle with a specific surface of BET = 250 m²/g and thus made of only approximately 10 graphene sheets, is proposed as a nanofiller for rubbers. When homogenously dispersed, it works at low loadings enabling the replacement of carbon black (CB), increase in efficiency, or reduction in filler concentration. Actually the appropriate preparation yielded nanocomposites in which just 3 phr are sufficient to significantly improve the rheological, curing and mechanical properties of different rubbers, as shown for Chlorine-Isobutylene-Isoprene Rubber (CIIR), Nitrile-Butadiene Rubber (NBR), Natural Rubber (NR), and Styrene-Butadiene Rubber (SBR). A mere 3 phr of MLG tripled the Young’s modulus of CIIR, an effect equivalent to 20 phr of carbon black. Similar equivalents are observed for MLG/CB mixtures. MLG reduces gas permeability, increases thermal and electrical conductivities, and retards fire behavior. The later shown by the reduction in heat release rate in the cone calorimeter. The higher the nanofiller concentration is (3 phr, 5 phr, and 10 phr was investigated), the greater the improvement in the properties of the nanocomposites. Moreover, the MLG nanocomposites improve stability of mechanical properties against weathering. An increase in UV-absorption as well as a pronounced radical scavenging are proposed and were proved experimentally. To sum up, MLG is interesting as a multifunctional nanofiller and seems to be quite ready for rubber development. T2 - TOP 2016, VIII International Conference on “Times of Polymers and Composites” CY - Naples, Italy DA - 19.06.2016 KW - Graphene KW - Nanocomposite KW - Rubber PY - 2016 SN - 978-0-7354-1390-0 DO - https://doi.org/10.1063/1.4949621 SN - 0094-243X SN - 1551-7616 VL - 1736 SP - 020046, 1 EP - 4 PB - AIP AN - OPUS4-36864 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Krüger, Simone A1 - Gluth, Gregor A1 - Watolla, Marie-Bernadette A1 - Morys, Michael A1 - Häßler, Dustin A1 - Schartel, Bernhard T1 - Neue Wege: Reaktive Brandschutzbeschichtungen für Extrembedingungen N2 - Wesentlich für das Sicherheitsniveau und damit die nachhaltige Wettbewerbsfähigkeit des Technologiestandortes Deutschland ist der Brandschutz in Industrieanlagen, in Gebäuden und im Transportwesen. Der vorbeugende bauliche Brandschutz hat u. a. das Ziel, die Brand- und Rauchausbreitung im Brandfall für eine gewisse Zeit zu behindern, damit die erforderlichen Lösch- und Rettungsarbeiten durchgeführt werden können. Dies geschieht u.a. durch Anforderungen an die Feuerwiderstandsfähigkeit brandbeanspruchter Bauteile. Der Feuerwiderstand eines Bauteils ist die Fähigkeit während eines angegebenen Zeitraums in einer genormten Feuerwiderstandsprüfung bezüglich mechanischer Stabilität und/oder thermischer Isolierung nicht zu versagen. Reaktive Brandschutzbeschichtungen erhöhen für viele Bauteile sehr effektiv den Feuerwiderstand. Die Beschichtungen und die Brandprüfungen müssen jedoch an die immer komplexeren Anwendungen und/oder extremeren Anforderungen angepasst und weiterentwickelt werden. Aktuelle Forschungsschwerpunkte liegen dabei in der Entwicklung neuer Materialien (z.B. Geopolymere, keramisierende Beschichtungen, silikonbasierte Beschichtungen) für extreme Brandszenarien (extreme Temperaturen, lange Beanspruchungszeiten) und in der Realisierung komplexer Funktionalitäten (komplexe Geometrien, bewegliche Komponenten) sowie in der Entwicklung neuer Testmethoden (Feuerwiderstand als bench-scale Tests, kostengünstiges Screening, Feuerwiderstand in extremen Brandszenarien). Die Entwicklung geht dabei weg von der präskriptiven Bewertung hin zur leistungsorientierten (performance-based) Bewertung in individuellen Brandszenarien oder von komplexen Bauteilen. Im Rahmen dieser Arbeit werden Lösungsansätze für die neuen Herausforderungen an die reaktiven Brandschutzsysteme unter Extrembedingungen und deren Testmöglichkeiten vorgestellt und diskutiert. Im Mittelpunkt stehen dabei neu entwickelte bench-scale Testmethoden zum Screening von neuen Beschichtungsmaterialien sowie zur Beurteilung spezieller bzw. materialspezifischer Aspekte des Feuerwiderstands unter Extrembedingungen. KW - Reaktive Brandschutzsysteme KW - Brandtest PY - 2016 DO - https://doi.org/10.1002/bate.201600032 SN - 0932-8351 SN - 1437-0999 VL - 93 IS - 8 SP - 531 EP - 542 PB - Ernst & Sohn Verlag CY - Berlin AN - OPUS4-37115 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Müller, Patrick A1 - Morys, Michael A1 - Sut, Aleksandra A1 - Jäger, Christian A1 - Illerhaus, Bernhard A1 - Schartel, Bernhard T1 - Melamine poly(zinc phosphate) as flame retardant in epoxy resin: Decomposition pathways, molecular mechanisms and morphology of fire residues N2 - Synergistic multicomponent systems containing melamine poly(metal phosphate)s have been recently proposed as flame retardants. This work focuses on the decomposition pathways, molecular mechanisms and morphology of the fire residues of epoxy resin (EP) flame retarded with melamine poly(zinc phosphate) (MPZnP) to explain the modes of action and synergistic effects with selected synergists (melamine polyphosphate (MPP) and AlO(OH), respectively). The total load of flame retardants was always 20 wt.%. The decomposition pathways were investigated in detail via thermogravimetric Analysis coupled with Fourier transform infrared spectroscopy. The fire residues were investigated via elemental analysis und solid-state nuclear magnetic resonance spectroscopy. The morphology of intumescent fire residues was investigated via micro-computed tomography and scanning electron microscopy. EP + (MPZnP + MPP) formed a highly voluminous residue that showed structural features of both EP + MPZnP and EP + MPP, resulting in a highly effective protection layer. EP + (MPZnP + AlO(OH)) preserved the entire quantity of phosphorus content during combustion due to the Formation of Zn₂P₂O₇ and AlPO₄. KW - Melamine poly(metal phosphate) KW - Flame retardancy KW - Epoxy resin KW - Solid-state NMR KW - Micro-computed tomography KW - Fire residue PY - 2016 DO - https://doi.org/10.1016/j.polymdegradstab.2016.06.023 SN - 0141-3910 VL - 130 SP - 307 EP - 319 PB - Elsevier AN - OPUS4-36863 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Scarfato, Paola A1 - Incarnato, L. A1 - Di Maio, L. A1 - Dittrich, Bettina A1 - Schartel, Bernhard T1 - Influence of a novel organo-silylated clay on the morphology, thermal and burning behavior of low density polyethylene composites N2 - The functionalization of a natural sodium montmorillonite (MMT) with (3-glycidyloxypropyl)trimethoxysilane by a silylation procedure is presented, and its use as nanofiller in the melt compounding of low density polyethylene (LDPE) nanocomposites. In particular, the effects on the thermal stability and flame retardant properties of melt compounded LDPE nanocomposites are analyzed, with and without magnesium hydroxide (MH) as an additional conventional flame retardant. The purpose was to investigate possible synergistic effects between the two inorganic fillers on fire behavior. The obtained organosilylated clay showed higher interlayer spacing than the original MMT and good thermal stability, higher than that of many commercial organoclays modified with alkylammonium salts. Its addition to LDPE allowed the production of hybrids with nanoscale dispersion of the filler, as demonstrated by X-ray diffraction. The simultaneous presence of MH, which strongly interacts with the nanoclay, hindered intercalation of the polymer chains between the clay galleries and clay layer exfoliation within the LDPE resin. The investigation of the thermal and burning behavior of the LDPE nanocomposites indicated that the organosilylated clay alone shows only a limited residual protection layer effect. In combination with MH the nanocomposites have a small adverse effect on the reaction to small flame as measured by the Oxygen index and UL 94 testing, and, surprisingly, no effect on the peak heat release rate in the cone calorimeter. The quality of the fire residue was lacking on the microscopic scale. The ternary LDPE/MH/ organoclay systems investigated did not open the door to reducing MH content in halogen-free flame retardant LDPE yet, but demand further research. KW - Nano structures KW - Polymer-matrix composites KW - High-temperature properties KW - Thermoplastic resin KW - Burning behavior KW - Fire retardancy PY - 2016 DO - https://doi.org/10.1016/j.compositesb.2016.05.053 SN - 1359-8368 VL - 98 SP - 444 EP - 452 PB - Elsevier AN - OPUS4-36865 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schartel, Bernhard A1 - Timme, Sebastian A1 - Hörold, Andreas A1 - Trappe, Volker A1 - Korzen, Manfred T1 - Composites in fire: Intermediate-scale testing of sandwich panels and shells N2 - Intermediate-scale testing is indispensable when investigating the fire resistance under simultaneous compressive load of components made of glass- and carbon-fibre-reinforced composites (GFRP and CFRP). BAM is successfully operating an intermediate-scale test stand, developed for a specimen size of 500 mm x 500 mm (1000 mm). The fire resistance in terms of fire stability of CFRP and GFRP sandwiches are investigated, e.g. at 20 % of their compressive failure load at room temperature. Times to failure increase by up to a factor of 4 due to intumescent coatings. For GFRP sandwiches, different core structures with and without additional flame retardants show an astonishing impact on time to failure. CFRP shell structures are investigated on the intermediate scale with and without stringer reinforcements, resulting in completely different mechanical failure behaviour in the ultimate load test as opposed to the fire resistance test. The stringers become the only load-carrying part, while the shell acts as a protective layer. Thus the design exploiting this self-protection potential, i.e. the residue of the front skin protecting the load-bearing structure, is highlighted as a most promising route to enhance the fire resistance of lightweight materials. T2 - Interflam 2016 CY - Egham, Surrey, UK DA - 04.06.2016 KW - composite KW - fire stability KW - fire resistance KW - sandwich panels KW - shells KW - intermediate-scale testing PY - 2016 SN - 978-0-9933933-2-7 SN - 978-0-9933933-3-4 VL - 2 SP - 1465 EP - 1470 PB - Interscience communications AN - OPUS4-36892 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Rabe, Sebastian A1 - Schartel, Bernhard T1 - Rapid mass calorimeter - High throughput fire performance screening N2 - Modern flame retardant polymeric materials often stand for multicomponent systems consisting of different ingredients. Using a variety of flame retardants, fillers, additives, synergists and adjuvants as well as applying different concentrations, particle size distributions, encapsulation, and so forth lead to a vast multidimensional matrix of possible formulations. Actual, comprehensive elucidations are no longer possible due to time, material and cost limitations. The task is dying for accelerated procedures, for high-throughput methods. Therefore we developed the Rapid Mass Calorimeter based on a Mass Loss Calorimeter with attached thermopile chimney and a linear motion unit for semi-automatic sample change. Together with the reduction in specimen size (2 cm x 2 cm), a saving of time around 70% and a saving of material of 96% is achieved not considering the strongly reduced calibration and maintenance efforts required for the Mass Loss Calorimeter. The correlations between the results of the Rapid Mass Calorimeter and the Cone Calorimeter as well as to the Oxygen Index and UL94 classification are described; the effects such as when reducing the specimen size are discussed. T2 - 27th Conference on Recent Advances in Flame Retardancy of Polymeric Materials, BCC CY - Stamford, Connecticut, USA DA - 22.05.2016 KW - Rapid mass calorimeter KW - Accelerated fire testing KW - Bench-scale fire testing PY - 2016 AN - OPUS4-36867 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schartel, Bernhard A1 - Frasca, Daniele A1 - Schulze, Dietmar A1 - Wachtendorf, Volker A1 - Krafft, Bernd A1 - Morys, Michael A1 - Böhning, Martin A1 - Rybak, Thomas T1 - Multilayer graphene rubber nanocomposites N2 - Multilayer Graphene (MLG), a nanoparticle with a specific surface of BET = 250 m2/g and thus made of only approximately 10 graphene sheets, is proposed as a nanofiller for rubbers. When homogenously dispersed, it works at low loadings enabling the replacement of carbon black (CB), increase in efficiency, or reduction in filler concentration. Actually the appropriate preparation yielded nanocomposites in which just 3 phr are sufficient to significantly improve the rheological, curing and mechanical properties of different rubbers, as shown for Chlorine-Isobutylene-Isoprene Rubber (CIIR), Nitrile-Butadiene Rubber (NBR), Natural Rubber (NR), and Styrene-Butadiene Rubber (SBR). A mere 3 phr of MLG tripled the Young’s modulus of CIIR, an effect equivalent to 20 phr of carbon black. Similar equivalents are observed for MLG/CB mixtures. MLG reduces gas permeability, increases thermal and electrical conductivities, and retards fire behavior. The later shown by the reduction in heat release rate in the cone calorimeter. The higher the nanofiller concentration is (3 phr, 5 phr, and 10 phr was investigated), the greater the improvement in the properties of the nanocomposites. Moreover, the MLG nanocomposites improve stability of mechanical properties against weathering. An increase in UV-absorption as well as a pronounced radical scavenging are proposed and were proved experimentally. To sum up, MLG is interesting as a multifunctional nanofiller and seems to be quite ready for rubber development. T2 - 8th Conference on Times of Polymers (TOP) & Composites CY - Ischia, Italy DA - 19.06.2016 KW - Graphene KW - Rubber KW - Nanocomposite PY - 2016 AN - OPUS4-36869 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Matzen, Melissa A1 - Kandola, B. A1 - Huth, Christian A1 - Schartel, Bernhard T1 - Controlled dripping of flame retarded thermoplastics N2 - Dripping and melt flow of the pyrolysing polymer melt can be both a benefit and a detriment during a fire. Well-adjusted melt flow and dripping are regularly beneficial to pass small-scale fire tests. Flame retardants often significantly change the melt viscosity of polymeric materials. The influence of certain flame retardants on the dripping behaviour of four commercial polymers is analysed based on experimental monitoring of the mass loss due to dripping, drop size and drop temperature as a function of the furnace temperature applied to a rod-shaped specimen. Investigating the thermal transition, thermal and thermo-oxidative decomposition, as well as the viscosity of the polymer and collected drops accomplish the work and connects dripping and melt flow with physical and chemical processes. Various flame retardant mechanisms affect the dripping behaviour in the UL 94 test. A changed viscosity and reduction in decomposition temperature also play a major role. T2 - 4th International Symposium on Flame-Retardant Materials & Technologies, ISFRMT 2016 CY - Changchun, China DA - 15.06.2016 KW - Dripping KW - Fire testing KW - Flame retardancy KW - Thermoplastics PY - 2016 AN - OPUS4-36868 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bresch, Sophie A1 - Mieller, Björn A1 - Rabe, Torsten T1 - Optimization of Solid-State-Reactions of Calcium Cobaltite Ca3Co4O9 N2 - Calcium cobaltite is a promising p-type oxide thermoelectric material for high temperature applications due to its high figure of merit between 600 °C and 900 °C in air. The solid-state-reaction is well known for large scale powder synthesis of functional materials. As a high temperature process, the powder synthesis consumes a lot of energy. In different studies, different synthesis conditions were used for the preparation of calcium cobaltite powder. This study showed that a higher energy input (elevated temperatures, longer dwell times, or repeated calcinations) during powder synthesis does not increase but decrease the Seebeck coefficient and the electrical conductivity. The same correlation was determined for the densification. As a higher energy input leads to a larger grain size and therefore to a reduced sinter activity, it can be concluded that the thermoelectric properties are correlated with the sinter activity of the powder. These results can be used to minimize the energy demand for the powder synthesis of Ca₃Co₄ O₉. T2 - 14th European Conference on Thermoelectrics CY - Lisbon, Portugal DA - 20.09.2016 KW - Thermoelectrics KW - Solid-State-Reaction KW - Calcium cobaltite PY - 2016 AN - OPUS4-37543 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Sut, Aleksandra A1 - Greiser, Sebastian A1 - Jäger, Christian A1 - Schartel, Bernhard T1 - Aluminium diethylphosphinate versus ammonium polyphosphate: A comprehensive comparison of the chemical interactions during pyrolysis in flame-retarded polyolefine/poly(phenylene oxide) N2 - A systematic comparison of chemical interactions and fire behaviour is presented for the thermoplas-tic elastomer (block copolymer styrene-ethylene-butadiene-styrene) (TPE-S)/diethyl- and methylvinylsiloxane (Si)/poly(phenylene oxide) (PPO), flame-retarded with aluminium diethylphosphinate (AlPi)and with ammonium polyphosphate (APP), respectively. TPE-S/APP/Si/PPO performed better in the conecalorimeter test (reduction in peak heat release rate from 2042 to 475 kW m−2), but TPE-S/AlPi/Si/PPO inthe flammability tests (oxygen index (OI) and UL 94). This difference was caused by the different modes ofaction of APP (more in the condensed phase) and AlPi (mainly in the gas phase). Thermogravimetry cou-pled with Fourier transform infrared spectroscopy (TG-FTIR) was used to analyse the mass loss and theevolved gas products, while a Linkam hot-stage cell to investigate the decomposition in the condensedphase. Moreover, a detailed analysis of the fire residues was done using solid-state NMR.13C MAS NMRshowed that both flame-retarded compositions form graphite-like amorphous carbonaceous char, orig-inating from PPO.31P MAS NMR and29Si MAS NMR delivered important information about interactionbetween phosphorus and the siloxane. For TPE-S/AlPi/Si/PPO aluminium phosphate and silicon dioxideoccurred, while also silicophosphate was produced in TPE-S/APP/Si/PPO. The direct comparison of two ofthe most prominent halogen-free flame retardants containing phosphorus delivered meaningful insightsinto the modes of action and molecular mechanisms controlling flame retardancy. KW - Aluminium diethylphosphinate KW - Ammonium polyphosphate KW - Flame retardancy KW - Solid-state NMR KW - SEBS PY - 2016 SN - 0040-6031 SN - 1872-762X VL - 640 SP - 74 EP - 84 PB - Elsevier AN - OPUS4-37802 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Moser, Marko A1 - Schneider, Ralf A1 - Behnke, Thomas A1 - Schneider, Thomas A1 - Falkenhagen, Jana A1 - Resch-Genger, Ute T1 - Ellman’s and aldrithiol assay as versatile and complementary tools for the quantification of thiol groups and ligands on nanomaterials N2 - Simple, fast, and versatile methods for the quantification of thiol groups are of considerable interest not only for protein analysis but also for the characterization of the surface chemistry of nanomaterials stabilized with thiol ligands or bearing thiol groups for the subsequent (bio-) functionalization via maleimide−thiol chemistry. Here, we compare two simple colorimetric assays, the widely used Ellman’s assay performed at alkaline pH and the aldrithiol assay executed at acidic and neutral pH, with respect to their potential for the quantification of thiol groups and thiol ligands on different types of nanoparticles like polystyrene nanoparticles, semiconductor nanocrystals (SC NC), and noble metal particles, and we derive criteria for their use. In order to assess the underlying reaction mechanisms and to obtain stoichiometry factors mandatory for reliable thiol quantification, both methods were studied photometrically and with electrospray ionization time-of-flight mass spectrometry (ESI-TOF-MS), thereby demonstrating the influence of different thiols on the reaction mechanism. Our results underline the suitability of both methods for the quantification of directly accessible thiol groups or ligands on the surface of 2D- and 3D-supports, here exemplarily polystyrene nanoparticles. Moreover, we could derive strategies for the use of these simple assays for the determination of masked (i.e., not directly accessible) thiol groups like disulfides such as lipoic acid and thiol stabilizing ligands coordinatively bound to Cd and/or Hg surface atoms of II/VI and ternary SC NC and to gold and silver nanoparticles. KW - Nanoparticles KW - Ligands KW - Ellman KW - Aldrithiol KW - Quantification PY - 2016 DO - https://doi.org/10.1021/acs.analchem.6b01798 SN - 0003-2700 SN - 1520-6882 VL - 88 IS - 17 SP - 8624 EP - 8631 PB - ACS Publications CY - Washington AN - OPUS4-37561 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Frasca, Daniele A1 - Schulze, Dietmar A1 - Böhning, Martin A1 - Krafft, Bernd A1 - Schartel, Bernhard T1 - Multilayer graphene chlorine isobutyl isoprene rubber nanocomposites: influence of the multilayer graphene concentration on physical and flame-retardant properties N2 - In recent years, different nanoparticles have been proposed and successfully introduced as nanofillers in rubber nanocomposites. In this study, multilayer graphene (MLG) is proposed as a nanoparticle that functions efficiently at low concentrations. MLG consists of just 10 or so graphene sheets. Chlorine isobutyl isoprene rubber (CIIR)/MLG nanocomposites with different MLG loadings were prepared using an ultrasonically assisted solution mixing procedure followed by two-roll milling. The incorporation of MLG provides a clear improvement in the rheological, mechanical, curing, and gas barrier properties of the nanocomposites. Adding only 3 phr ofMLGto CIIR increased the Young’s modulus by more than two times and reduced the permeability ofO2 andCO2 by 30%. Higher nanofiller concentrations yielded further improvement in the properties of the nanocomposites. Moreover, CIIR/MLG nanocomposites showed reduced flammability. KW - Graphene KW - Rubber KW - Nanocomposites KW - Flammability KW - Reinforcement PY - 2016 DO - https://doi.org/10.5254/rct.15.84838 SN - 0035-9475 VL - 89 IS - 2 SP - 316 EP - 334 AN - OPUS4-37595 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Falkenhagen, Jana T1 - Polymer characterisation by multidimensional techniques with focus on LC - MALDI/ESI-TOF-MS N2 - Since the first LC/ ESI-MS experiment of the Nobel prize winner John B. Fenn in 1984, the coupling of liquid chromatographic to mass spectrometric techniques gained a continuous rapid development. The lecture will give a general survey of different LC separation techniques as size exclusion chromatography (SEC), liquid adsorption chromatography (LAC), liquid chromatography at critical conditions (LCCC) and gradient elution liquid chromatography (GELC) combined with Matrix assisted Laser Desorption Ionization (MALDI) respectively Electrospray Ionization (ESI) Time of Flight (TOF) mass spectrometry. Often the deficiencies of stand-alone methods can be bridged. LC, blind to structural information needs mass spectrometry as one of the most powerful detectors able to give detailed information on e.g. the repeat units, functionalization or copolymer composition of the chromatographic separated constituents. A separation prior to MS reduces the polydispersity which is one of the reasons for failing of MS. Also problems with different ionization probabilities in complex mixtures can partly be overcame. On the basis of different examples on- and offline coupling principles will be compared and the pros and cons of both mass spectrometric techniques will be discussed. Recently, MALDI imaging techniques in coupling with chromatography have become interesting e.g. for visualization of copolymer composition. T2 - International Symposium GPC/SEC and Related Techniques CY - Amsterdam, The Netherlands DA - 26.09.2016 KW - Polymers KW - Liquid chromatography KW - MALDI-TOF-MS KW - ESI-TOF-MS PY - 2016 AN - OPUS4-37629 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schartel, Bernhard T1 - Tailored bench-scale fire testing in research and development N2 - Research and development of flame retarded polymeric materials generate a strong demand for bench-scale fire testing saving costs, time, and material. Hereby the good correlation to the fire tests mandatory for later products is the key challenge. Three examples are presented for tailored bench-scale fire test set-ups based on recent projects in my working group: - STT MuFu+: A bench-scale set-up was designed to investigate intumescent coatings protecting steel. An electric oven was modified, so that the standard time temperature curve is applied to a 75 mm x 75 mm coated steel plate. The plate is tested in a vertical position the temperature increase is measured at its back. A high temperature endoscope is used for online observation of the intumescence. Perfect fire residues are produced ready for further investigation. - Rapid Mass Calorimeter: A bench-scale set-up was designed to speed up cone calorimeter testing. Specimen size reduction and using a modified mass loss calorimeter deliver crucial reduction in time and material needed for screening materials. More than 70 different materials, polymers and flame retarded polymers, have been used to understand the meaning of the results and to check the correlation with cone calorimeter results. - Bench-scale Cable Testing Module: A bench-scale set-up was designed to screen cables with respect to their performance in the large scale test (EN 50399). A module is proposed replacing the cone heater and balance in the cone calorimeter. Thus the whole set-up of the cone calorimeter is used determining the heat release by means of oxygen consumption, whereas the novel cable module become cheap and easy. A good correlation to EN 50399 was observed indicating the module being an excellent screening tool for the development of flame retardant cables. The three examples show how close tailored bench-scale testing comes to simulate the performance in larger mandatory fire tests. Proper bench-scale approaches are used for reliable inexpensive assessment when screening novel materials and products. Acknowledgements Thanks go to Michael Morys, who has elaborated the STT MuFu+ in his PhD, and Sebastian Rabe, who has elaborated the Rapid Mass Calorimeter in his PhD. Thanks go to Corning Optical Communications (Emanuela Gallo and Waldemar Stöcklein) for the joint project developing the Bench-scale Cable Testing Module. Thanks go to Patrick Klack elaborating the cable module. T2 - 252nd ACS National Meeting Fall 2016 CY - Philadelphia, USA DA - 21.08.2016 KW - Bench-scale fire testing PY - 2016 AN - OPUS4-37377 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schartel, Bernhard A1 - Frasca, Daniele A1 - Schulze, Dietmar A1 - Krafft, Bernd A1 - Böhning, Martin A1 - Rybak, Thomas A1 - Wachtendorf, Volker T1 - Rubber / Multilayer graphene nanocomposites N2 - Rubbers are usually reinforced with a high content (> 40 phr) of carbon black (CB) and silica. In recent years several nanofillers have been proposed, including expanded graphite/graphene. Extremely low loading of nanoparticles can considerably improve the properties. In this contribution multilayer graphene (MLG) is investigated as efficient nanofiller for rubbers. MLG has a BET specific surface area of 250 m2/g. Compared to a single graphene sheet, the MLG used constitutes only approximately 10 graphene sheets. When homogenously dispersed, it works at low loadings enabling the replacement of CB, increase in efficiency, or reduction in filler concentration. Actually the appropriate preparation yielded nanocomposites in which just 3 phr are sufficient to significantly improve the rheological, curing and mechanical properties of different rubbers, as shown for Chlorine-Isobutylene-Isoprene Rubber (CIIR), Nitrile-Butadiene Rubber (NBR), Natural Rubber (NR), and Styrene-Butadiene Rubber (SBR). A mere 3 phr of MLG tripled the Young’s modulus of CIIR, an effect equivalent to 20 phr of carbon black. Similar equivalents are observed for MLG/CB mixtures. MLG reduces gas permeability, increases thermal and electrical conductivities, and retards fire behavior. The higher the nanofiller concentration is (3 phr, 5 phr, and 10 phr was investigated), the greater the improvement in the properties of the nanocomposites. Moreover, the MLG nanocomposites improve stability of mechanical properties against weathering. An increase in UV-absorption as well as a pronounced radical scavenging are proposed and were proved experimentally. To sum up, MLG is interesting as multifunctional nanofiller and seems to be quite ready for rubber development. T2 - 9th International Conference on Modification, Degradation and Stabilization of Polymers, MoDeSt 2016 CY - Cracow, Poland DA - 04.09.2016 KW - Graphene KW - Nanocomposites KW - Rubber KW - Reinforcement KW - Weathering stability PY - 2016 AN - OPUS4-37378 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Epping, Ruben A1 - Falkenhagen, Jana T1 - Characterization of statistical EO-PO copolymers containing different end groups by UPLC/ESI-MS N2 - Commercial statistical ethylene oxide (EO) and propylene oxide (PO) copolymers of different monomer compositions and different average molar masses were studied by liquid chromatography under critical conditions (LCCC). Theoretical predictions of the existence of a critical adsorption point (CPA) for statistical copolymers with a given chemical and sequence distribution, could be studied and confirmed. An improved way to determine these critical conditions in a copolymer, alongside the inevitable chemical composition distribution (CCD), with the aid of mass spectrometric detection is described. Shift of the critical eluent composition with the monomer composition of the polymers could be observed. Due to the relatively low average molecular weight, broad molecular weight distribution (MWD) and the presumed existence of different end group functionalities as well as sequence distribution, gradient separation only by CCD was not possible. Therefore isocratic separations at the CPA of definite CCD’s were applied. Although the various present distributions partly superimposed the separation process the goal of separation by end group functionality could still be achieved on the basis of the additional dimension of ESI-MS. The existence of HO-H besides the desired AllylO-H end group functionalities could be confirmed and their amount could be estimated. T2 - International Symposium GPC/SEC and Related Techniques CY - Amsterdam, The Netherlands DA - 26.09.2016 KW - Polymers KW - UPLC KW - ESI-TOF-MS PY - 2016 AN - OPUS4-37632 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Mieller, Björn A1 - Rangelov, V. A1 - Rabe, Torsten T1 - Advancements in pressure-assisted sintering technology for low temperature co-fired ceramics (LTCC) N2 - Steadily increasing demands on design and dimensional accuracy of ceramic multilayer modules, as well as the processing of new materials, require continuous improvements of manufacturing technology, especially thermal processes. The capabilities of pressure-assisted sintering (PAS) for the manufacturing of highly integrated low temperature co-fired ceramics (LTCC) multilayer have been considerably extended in the last years by procedural and device-related advancements. A lambda probe has been integrated in a sintering press prototype to monitor and control the process atmosphere. Thereby, the development of oxygen partial pressure during binder burnout of real modules can be observed. On the other hand, the oxygen partial pressure can be regulated during densification, for example to prevent diffusion of silver from circuit paths into the surrounding LTCC. Thin-film capable surfaces can be produced without post-processing by using setter plates made of glass-like carbon in an advanced PAS process under nitrogen. A newly developed advancement of this approach enables in-situ hot-embossing of LTCC during PAS by using structured glass-like carbon molds. The prototype press is further extended by a sensitive displacement transducer for monitoring the thickness shrinkage of real modules with an edge length of up to 8 inch. T2 - ICC6 CY - Dresden, Germany DA - 21.08.2016 KW - LTCC KW - Shrinkage measurement KW - Oxygen partial pressure KW - Hot-embossing PY - 2016 AN - OPUS4-37250 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schartel, Bernhard A1 - Timme, Sebastian A1 - Hörold, Andreas A1 - Trappe, Volker A1 - Korzen, Manfred T1 - Composites in fire: Intermediate-scale testing of sandwich panels and shells N2 - Intermediate-scale testing is indispensable when investigating the fire resistance under simultaneous compressive load of components made of glass- and carbon-fibre-reinforced composites (GFRP and CFRP). BAM is successfully operating an intermediate-scale test stand, developed for a specimen size of 500 mm x 500 mm (1000 mm). The fire resistance in terms of fire stability of CFRP and GFRP sandwiches are investigated, e.g. at 20 % of their compressive failure load at room temperature. Times to failure increase by up to a factor of 4 due to intumescent coatings. For GFRP sandwiches, different core structures with and without additional flame retardants show an astonishing impact on time to failure. CFRP shell structures are investigated on the intermediate scale with and without stringer reinforcements, resulting in completely different mechanical failure behaviour in the ultimate load test as opposed to the fire resistance test. The stringers become the only load-carrying part, while the shell acts as a protective layer. Thus the design exploiting this self-protection potential, i.e. the residue of the front skin protecting the load-bearing structure, is highlighted as a most promising route to enhance the fire resistance of lightweight materials. T2 - Interflam 2016, 14th International Interflam Conference CY - Egham, UK DA - 04.07.2016 KW - Composites KW - Carbon fibre KW - Shells KW - Sandwich panels KW - Fire resistance KW - Fire stabiliy KW - Stringer reinforced components PY - 2016 AN - OPUS4-36870 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Martins, Marta S. S. A1 - Slawik, T. A1 - Moritz, T. A1 - Schartel, Bernhard A1 - Magalhães, F. D. A1 - Pereira, C.M.C. T1 - Ceramic tapes as fire protective coatings for CFRP composites N2 - Ceramic tapes with different chemical compositions were produced by tape casting technology. Unlike the traditional solvent-based slurries, we have used eco-friendly water based formulations. These thin coatings were afterwards used as top layer on 6-layered carbon fibre epoxy composites as intended fire protective coatings. Tape C, containing cellulose fibres, has demonstrated to be the most effective coating regarding the fire reaction behaviour. These coatings are attractive in the sense that: Their composition can be more or less tailored, there are easily impregnated with epoxy resin, and they are extremely flexible, and can therefore be used in a wide range of applications. T2 - COST MP1105 Final Conference Innovations in Flame Retardancy of Textiles and Related Materials CY - Poznan, Poland DA - 27.04.2016 KW - Composites KW - Fire retardancy KW - Laminates KW - Carbon fibres PY - 2016 AN - OPUS4-36871 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Agudo Jácome, Leonardo A1 - Pöthkow, K. A1 - Paetsch, O. A1 - Hege, H.-C. T1 - 3D reconstruction, visualization and quantification of dislocations from TEM stereo-pairs N2 - A wide range of properties in crystalline materials is affected by the presence of dislocations, the carriers of plastic deformation. Dislocations can be thought of as filiform structures, characterized by geometrical factors such as their Burgers vector, slip plane, length per unit volume (dislocation density) and line direction. In technical materials such as functional and structural alloys, as well as in minerals, the understanding of bulk deformation driven by dislocation activity is of paramount importance, and thus also the techniques that allow its characterization. Since decades, diffraction contrast in the transmission electron microscope (TEM) is widely implemented to image and describe two-dimensional (2D) projections of dislocation substructures in thin foils [1]. Recently, the use of electron tomography was applied for the first time to fully reconstruct a 3D dislocation network in a GaN epilayer [2]. Although this latter technique has gained popularity, it usually requires an elaborate experimental setup, as well as sophisticated image post-processing methods for a successful reconstruction. Stereoscopic methods in the TEM also have traditionally allowed the three-dimensional (3D) observation of dislocations [e. g. 3]. For this purpose, the same region of a TEM foil is imaged using the same diffraction vector with two beam directions slightly tilted from each other. Subsequently, the pair of images is observed with help of stereo-viewers or 3D glasses. Based on this principle, a system based on a special hardware and software combination was developed for segmentation and analysis of stereomicroscopy data in biological research, and it was also used to analyze simple dislocation structures [4]. In the present contribution a simple software tool is introduced, which has been developed to reconstruct, visualize and quantify dislocation substructures in the thicker regions of electron-transparent foils. A special focus is set on the use of scanning (S)TEM for its implementation. As depicted in Figure 1, the tool is based on the separate tracing of dislocation line segments on both images of a stereo-pair. The points 1, 2 and 3 are marked on the images viewed by the left and right eyes (Figures 1a and b, respectively), showing an relative displacement Δx on the superimposed images in the anaglyph of Figure 1c. This Δx is given by the point’s depth Δh and by the stereo-angle ϑ, as shown in Figure 1d. By knowing the beam direction for the left and right images (BL and BR, respectively), ϑ can be determined, and hence also Δh. Once the depth information from all traced nodes is gained, a reconstruction is made (Figure 1e) where the line length can directly be read from the tool’s interface. The setup is merely geometrical and only needs the relative tilt between both images, the direction of the tilt axis and the image calibration, thus allowing asymmetrical tilts with respect to the foil normal. The foil thickness is measured directly from the endings of the dislocations on the bottom and top surfaces of the TEM foil, and is determined as t ~ 370 nm for the region in Figure 1. With t, the volume is in Figure 1e is also known, and the total dislocation density of the region is calculated as ρt = 44.4 x 1012 m∙m-3. It is clear from Figure 1 that in the Ni-base superalloy presented here, the dislocation substructures are highly localized towards the interface between the two phases of which the microstructure is composed, γ and γ’ (labeled in Figure 1a). The reconstructed model allows a separation of the dislocation densities within the γ and the γ’ phases and at their interface, which would be rather difficult by using common methods such as the one proposed by Ham [5]. Thus the partial dislocation densities are measured as ργ = 1.7 x 1012 m∙m-3, ργ’ = 2.7 x 1012 m∙m-3 and ργ/γ’ = 40.0 x 1012 m∙m-3. The tool also incorporates the knowledge of the crystallographic positions at the two tilts to enable plotting the line segment orientations. One can chose to display the resulting line directions as an interactive table; as an additional spherical spatial graph, where all lines extend from the center of a sphere; as a 2D plot of the spherical coordinates θ and φ; or as points plotted on a stereographic projection. Thus, a simple software tool has been developed that allows the reconstruction, visualization and quantification of foil thickness, localized dislocation densities (or other filiform substructures) and orientations based on only one stereo-pair T2 - Microscopy and Microanalysis 2016 CY - Columbus, OH, USA DA - 24.06.2016 KW - Dislocation KW - Diffraction contrast KW - 3D reconstruction KW - Stereoscopy KW - Scanning transmission electron microscopy PY - 2016 AN - OPUS4-39278 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Rabe, Torsten A1 - Mieller, Björn T1 - Drucksintern von hochintegrierten LTCC-Schichtverbunden - Möglichkeiten und Grenzen N2 - In der Keramikfertigung werden verschiedene druckunterstützte Sintertechnologien wie heißisostatisches Pressen, Gasdrucksintern und uniaxiales Heißpressen eingesetzt. Eine Variante des uniaxialen Heißpressens stellt das druckunterstützte Sintern von LTCC-Modulen dar. Es wird mit einem gegenüber dem klassischen Heißpressen deutlich reduzierten Druck von nur etwa 1 MPa operiert. Mit der Einführung der Drucksintertechnik wurde es möglich, großflächige, ebene LTCC-Schichtverbunde ohne laterale Schwindung dicht zu sintern und so eine kostengünstige Fertigung im Nutzen zu realisieren. Mit dem Trend zur Miniaturisierung und Funktionserweiterung von Schaltungsträgern sind Applikationskonzepte entwickelt worden, die eine Integration von Mikrowellen-, Kondensator-, Piezo- und Ferritmaterialien durch Co-Sinterung beinhalten. Kavitäten und Kanäle werden benötigt, um LTCC-Schichtverbunde auch in der Sensorik und Mikrofluidik einzusetzen. Die Umsetzung dieser Konzepte erfordert häufig diffizile Sinterprogramme mit temperaturgesteuerter Einstellung von uniaxialem Druck und Sauerstoffpartialdruck. Basierend auf den Ergebnissen zahlreicher F+E-Vorhaben werden Möglichkeiten und Grenzen der Drucksintertechnologie für die Herstellung dieser LTCC-Schichtverbunde illustriert. Vorgestellt wird ein weiterentwickeltes Drucksinteraggregat. Durch Integration von in-situ Schwindungsmessung sowie Mess- und Regeleinrichtungen für den Sauerstoffpartialdruck stehen erweiterte Möglichkeiten für die Optimierung des Drucksinterprozesses von LTCC-Schichtverbunden zur Verfügung. T2 - Symposium: "Keramische Mehrlagentechnik - Herstellverfahren und Anwendungen" CY - Erlangen, Germany DA - 30.11.2016 KW - Heißpressen KW - Sintern KW - Schichtverbunde PY - 2016 AN - OPUS4-38595 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Agudo Jácome, Leonardo T1 - Characterization of dislocation networks N2 - The presentation shows how the three-dimensional quantification of dislocations and their characteristic features, e.g. Burgers vector, line direction, dislocation density, is carried out at the transmission electron microscope in scanning mode (STEM) at Division 5.1 at BAM. Exemplarily, the methods are shown for Ni-base superalloy single crystals, for which a short introduction is given using further TEM techniques. Additional examples on low angle grain boundaries, nucleation of oxides at dislocations and interaction of dislocations and carbides are shown. The content of the presentation was addapted, aiming at scientists who work within the DFG Priority Programme 1713 "Strong coupling of thermo-chemical and thermo-mechanical states in applied materials". T2 - SPP 1713: Focus Group Meeting Experiments CY - Berlin, Germany DA - 27.06.2016 KW - Dislocation KW - Transmission electron microscopy KW - Three-dimensional (3D) characterization KW - Ni-base superalloy KW - Creep PY - 2016 AN - OPUS4-40278 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schartel, Bernhard A1 - Dittrich, Bettina A1 - Hofmann, D. A1 - Wartig, K.-A. A1 - Mülhaupt, R. T1 - Born in fire to kill fire – graphene in flame retardant nanocomposites N2 - Carbon black, multiwall carbon nanotubes, expanded graphite, multilayer graphene and graphene are compared comprehensively as flame retardants in nanocomposites to each other. Different polymer matrices are investigated as well as changing the concentration of the carbon fillers. Distinct combinations of graphene with conventional flame retardants are investigated. Phenomena and mechanisms are identified controlling the pyrolysis and fire behavior. The viscosity of the nanocomposites and their thermal conductivity as well are dramatically changed compared to the polymers influencing the time to ignition and flammability. During pyrolysis graphene functioned as inert filler and formed a residual protective layer reducing the peak heat release rate. The influence of graphene on the effectivity of various conventional halogen-free flame retardants depends strongly on their modes of action. The addition of a small amount of graphene to an intumescent flame retardant poly(propylene) led to an improvement in the cone calorimeter. The further increase of graphene content gained deceleration of swelling and a decrease of the final height of the intumescent layer. In combination with metal hydroxide, 1 wt% graphene closed the macroscopic surface structure and densified the microscopic structure of the fire residues tremendously. Due to this improved residue structure, metal hydroxides and graphene showed synergistic cooperation in terms of oxygen index and UL 94 classification (HB/V-1 to V-0). T2 - Rudolstädter Kunststoff-Tag CY - Rudolstadt, Germany DA - 12.10.2016 KW - Graphene KW - Nanocomposite KW - Flame retardant KW - Flammability KW - Pyrolysis PY - 2016 AN - OPUS4-38116 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - BOOK A1 - Schubert, Martina A1 - Schartel, Bernhard A1 - Lang, M. A1 - Yin, Huajie A1 - Dittrich, Bettina A1 - Heidemeyer, P. A1 - Bastian, Martin T1 - Wirkungsweise von halogenfreien Flammschutzmitteln in WPC N2 - Das Ziel des Forschungsvorhabens war die Untersuchung der Wirkungsweise von halogenfreien Flammschutzmitteln in WPC. Eine große Anzahl verschiedener Flammschutzmittel wurde hinsichtlich ihrer Wirkmechanismen umfassend untersucht, um ein Verständnis für die ablaufenden Prozesse zu entwickeln. Hierbei wurden verschiedene Brandtests eingesetzt, um die Materialien bezüglich verschiedener Applikationen (E&E, Transportwesen, Bauwesen) zu beleuchten. Die verschiedenen Untersuchungen liefern aber auch ein umfassendes Bild vom Brandverhalten in den verschiedenen Eigenschaften, wie Entflammbarkeit und Brandausbreitung. Die prinzipiellen Ansätze wurden anhand von verschiedenen Flammschutzmitteln beleuchtet, ihre Pyrolyse und ihre Performance in verschiedenen Brandtests gegenübergestellt. Bei der angestrebten geringen Zusatzmenge ist durch den Zusatz eines einzigen Flammschutzmittels keine zufriedenstellende Reduktion der Brandeigenschaften zu erwarten. Multikomponentensysteme zur Steigerung der Effizienz sind angezeigt. Einige prinzipielle Kombinationsmöglichkeiten wurden für alle Hauptflammschutzmittel durchgespielt. Die teilweise deutlichen Verbesserungen zeigen Wege zur erfolgreichen Produktentwicklung auf. So konnten bei den Spritzgießcompounds Eigenschaften erzielt werden, die eine UL 94 V0 Klassifizierung ermöglichen. Ein Einsatz der im Forschungsvorhaben hergestellten Compounds als Baustoff ist aufgrund des Brandverhaltens in den baustoffspezifischen Prüfungen nicht möglich. Hier sind weitere Flammschutz-Konzepte zu erproben. Gleitmittel nehmen bei den untersuchten Extrusionscompounds keinen Einfluss auf das Brandverhalten. Haftvermittler nehmen ebenfalls keinen signifikanten Einfluss auf das untersuchte Brandverhalten, können aber zu einer veränderten Verteilung der Füllstoffe und damit zur Ausbildung einer effektiveren Schutzschicht führen. Feinere Holzpartikel schneiden bei den Brandprüfungen besser ab als grobe Holzpartikel. Bei Einsatz von grobem Holz wird eine schlechtere Rückstandsstruktur ausgebildet, was das Brandverhalten negativ beeinflusst. Der Einsatz von vorbehandeltem Holz brachte nicht die erwartete Verbesserung. Die neu konzipierte Aufbereitungsanlage auf Basis des Planetwalzenextruders konnte erfolgreich in Betrieb genommen werden. Vergleichende Versuche mit dem Doppelschneckenextruder zeigten, dass der PWE-Aufbau eine gute Alternative zur etablierten DSE-Aufbereitung darstellt. Zusätzlich wurden an Compounds vielversprechender Flammschutzansätze weitere Materialprüfungen (Biegeversuch, Schlagversuch, Wasseraufnahme) durchgeführt, um den Einfluss der FSM auf die spezifischen Eigenschaften der WPC zu beleuchten. N2 - The objective of the research project was to investigate the effect of halogen-free flame retardants in WPC. A large number of different flame retardants was thoroughly examined regarding their effect mechanisms to develop an understanding for the processes taking place. Different fire tests were used to examine the materials with respect to the different applications (E&E, transportation, construction). Additionally, the different investigations provide a comprehensive picture of the fire behavior regarding the different properties, such as flammability and fire spread. The fundamental approaches were examined by means of different flame retardants and their pyrolysis and performance were compared in different fire tests. A satisfactory reduction of the fire properties by adding only one flame retardant cannot be expected with the intended low added amount. Multi-component systems to increase the efficiency are indicated. Some basic combination options were tried out for all main flame retardants. The partially considerable improvements illustrate ways for successful product development. This way, properties could be achieved in injection molding compounds, which allow for a UL 94 V0 classification. It is not possible to use the compounds introduced in the research project as building material due to the fire behavior in the building material specific tests. Further flame protection concepts need to be tested in this area. Slip agents do not have an influence on the fire behavior of the examined extrusion compounds. Adhesion promoters also do not have a significant influence on the examined fire behavior but can lead to a change in the distribution of the fillers and thus to the formation of a more effective protective layer. Finer wood particles performed better in the fire tests than coarse wood particles. When using coarse wood, an inferior residual structure is formed, which has an adverse effect on the fire behavior. The use of pretreated wood fibers did not bring the expected improvement. The newly conceived processing technique based on a planetary roller extruder (PRE) was successfully put into operation. Comparative tests with twin-screw extruders (TSE) showed that the PRE configuration is a good alternative to the established TSE processing. Additionally, further material testing (bending test, impact test, water absorption) was performed on promising flame retarded compounds to examine the influence of the fire retardants on the specific properties of the WPC. KW - Wood plastic composite KW - Halogen free KW - Flame retardancy PY - 2016 SN - 978-3-8440-4645-8 SN - 2364-754X SP - 1 EP - 88 PB - Shaker Verlag CY - Aachen AN - OPUS4-37482 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Agudo Jácome, Leonardo A1 - Pöthkow, K. A1 - Paetsch, O. A1 - Hege, H.-C. T1 - 3D Reconstruction, Visualization and Quantification of Dislocations from TEM Stereo-Pairs N2 - Dislocations, as carriers of plastic deformation, affect important properties in technical materials, e. g., plasticity. The realistic description of plastic deformation caused by dislocations demands the representative measurement of their features, e.g., line direction, slip plane, Burgers vector and density. Bulk deformation of structural and functional alloys requires reliable data from large regions. The filiform nature of dislocations interacting with complex microstructures additionally demands observation and analysis techniques that allow resolving the details of their interactions in space. The use of electron tomography for this purpose is bound to difficult and time consuming experimental setups, which are not always applicable to any material. In this contribution a new tool is presented, which enables the three-dimensional reconstruction, visualization and quantification of dislocation densities and directions from manual tracing of scanning transmission electron microscopy (STEM) stereo-pairs. Examples are shown from samples of a creep-deformed monocrystalline Ni-base superalloy. T2 - 3D Materials Science 2016 CY - St. Charles, Illinois, USA DA - 10.07.2016 KW - Dislocation KW - Scanning Transmission Electron Microscopy KW - 3D KW - Quantification KW - Superalloy PY - 2016 AN - OPUS4-42173 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Mieller, Björn A1 - Kuchenbecker, Petra A1 - Schulz, Bärbel A1 - Rabe, Torsten T1 - Heißprägen im Grünzustand und Sinterprägen - Zwei Verfahren zur Strukturierung keramischer Folien und Laminate N2 - Prägeverfahren bieten eine interessante Alternative zur Strukturierung keramischer Folien und Laminate. Im Gegensatz zur etablierten Stanz- oder Laserbearbeitung von Einzelfolien sind damit einerseits Strukturtiefen realisierbar, die nicht einem Vielfachen der Einzelfoliendicke entsprechen, andererseits können Strukturierungsgrade erzielt werden, bei denen perforierte Einzelfolien nicht mehr handhabbar sind. Heißprägen grüner Folien und Laminate erfolgt bei Temperaturen um 130 °C mit Metallstempeln. Die plastische Verformung erfolgt zeitabhängig. Dabei sind die Fließeigenschaften des polymeren Binders der Grünfolie maßgeblich für die Konturtreue der Prägung. Randeinzug und Gründichtegradienten um den Eindruck können zu Defekten im Sintergefüge führen. Je nach Sinterverfahren muss die Schwindung der geprägten Struktur berücksichtigt werden, eine Kombination dieses Verfahrens mit zero-shrinkage Techniken ist aber möglich. Sinterprägen stellt eine Erweiterung der Drucksintertechnologie für glaskeramische Komposite dar. Dabei wird ein Pressstempel aus glasartigem Kohlenstoff während des Brandes in die erweichte Glasphase des Komposits gedrückt. Die Abformung erfolgt durch viskosen Fluss der Glasphase. Mit Kenntnis des Dichte- und Viskositätsverlaufs des Werkstoffs kann das Verfahren so gestaltet werden, dass die Pressform konturtreu abgeformt wird. Mittels Sinterprägen lassen sich auch erhabene Strukturen realisieren, wobei diese häufig eine erhöhte Porosität aufweisen. T2 - Herbstsymposium 2016 | Keramische Mehrlagentechnik - Herstellverfahren und Anwendungen CY - Erlangen, Germany DA - 30.11.2016 KW - Folientechnik KW - Keramische Substrate KW - Low temperature co-fired ceramics (LTCC) PY - 2016 AN - OPUS4-38582 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Elert, Anna Maria A1 - Becker, Roland A1 - Dümichen, Erik A1 - Eisentraut, Paul A1 - Falkenhagen, Jana A1 - Sturm, Heinz A1 - Braun, Ulrike T1 - Comparison of methods used for microplastics detection N2 - The pollution of the environment with microplastics MP (particles < 5mm) is a problem of increasing concern.1 A consistent methodology that facilitates detection of MP is still missing. Here we present the data recorded by applying different MP identification methods to a soil fortified with known amounts of MP. T2 - MoDeSt Konferenz CY - Krakau, Poland DA - 4.09.2016 KW - Microplastics KW - Raman KW - FTIR KW - TED-GC-MS KW - GPC PY - 2016 AN - OPUS4-38161 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Schartel, Bernhard A1 - Wilkie, Charles A. A1 - Camino, Giovanni T1 - Recommendations on the scientific approach to polymer flame retardancy: Part 1—Scientific terms and methods N2 - The correct use of scientific terms, performing experiments accurately, and discussing data using unequivocal scientific concepts constitute the basis for good scientific practice. The significance and thus the quality of scientific communication rely on the proper use of terms and methods. It is the aim of this two-part article to support the community with recommendations for discussing the flame retardancy of polymers by addressing some of the most relevant points. The first article (part one of two) clarifies some scientific terms and, in some cases, such as for ‘‘pyrolysis,’’ ‘‘thermal decomposition,’’ and ‘‘fire resistance,’’ critically discusses their definitions in the field of fire science. Several comments are made on proper fire testing and thermal analysis, including some thoughts on uncertainty in fire testing. The proper use of distinct concepts in flame retardancy is discussed briefly in the subsequent second article (part two). This article tries to Balance imparting background on the subject with recommendations. It encourages to check scientific practice with respect to communication and applying methods. KW - Pyrolysis KW - Fire testing KW - Char KW - Flame retardant KW - Flammability KW - Fire property PY - 2016 DO - https://doi.org/10.1177/0734904116675881 SN - 0734-9041 SN - 1530-8049 VL - 34 IS - 6 SP - 447 EP - 467 PB - SAGE AN - OPUS4-38115 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -