TY - CONF A1 - Siebler, Daniel A1 - Hohberg, Michaela A1 - Rohwetter, Philipp A1 - Brusenbach, R. A1 - Plath, R. ED - Kalinowski, H.J. ED - Fabris, J.L. ED - Bock, W.J. T1 - Elastomeric fluorescent POF for partial discharge detection - recent progress N2 - We present recent progress in our development of fibre-optic sensors for the detection of partial discharge (PD) in silicone cable accessories, based on detecting related low-level optical emission. We experimentally show that the sensitive optical detection of PD can dramatically enhance the performance of conventional electrical PD measurement in electromagnetically noisy environments, and that it can yield high sensitivity and specificity even when no synchronous electrical PD measurement is conducted. This is demonstrated using a real-scale model of a high voltage cable accessory with a surface-attached conventional thermoplastic fluorescent polymer optical fibre (F-POF) sensor. In order to increase light collection efficiency, as a prerequisite for a commercially competitive implementation using cost-efficient detectors, sensing fibres will have to be integrated into the silicone rubber insulation, close to the potential origin of PD-induced damage. This is the rationale for our efforts to develop elastomeric fluorescent sensing fibres, tailored to the requirements of the application. We discuss specific challenges to be tackled and report on the successful implementation of all-silicone rubber fluorescent POF, to our best knowledge for the first time. © (2015) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only. T2 - OFS2015 - 24rd International conference on optical fibre sensors CY - Curitiba, Brazil DA - 28.09.2015 KW - Elastomeric polymer optical fibre KW - Fluorescent POF KW - High voltage KW - Cable monitoring KW - Partial discharge KW - Silicone rubber KW - Cable accessories PY - 2015 SN - 9781628418392 DO - https://doi.org/10.1117/12.2194875 SN - 0277-786X N1 - Serientitel: Proceedings of SPIE – Series title: Proceedings of SPIE VL - 9634 SP - 96343W-1 EP - 96343W-4 AN - OPUS4-34539 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Stengel, Dominik A1 - Peil, U. ED - Ruscheweyh, H. ED - Krafczyk, M. T1 - Zur Bemessung von Freileitungsgittermasten auf Wind auf Leiterseile nach der Freileitungsnorm DIN EN 50341-3-4: 2011 N2 - Der folgende Beitrag befasst sich mit der analytischen Herleitung eines sog. Spannweitenfaktors zur Berücksichtigung der Korrelation der Windeinwirkung auf weitgespannte Freileitungsseile. Insbesondere zur Abschätzung der Windlast auf Maste trägt dieser Lastfall maßgebend zur Bemessung bei. Mithilfe von Naturmessungen und Simulationen werden zugrunde gelegte Annahmen überprüft und validiert. Die Ergebnisse werden schließlich anhand der einschlägigen Regelwerke verglichen und bewertet. N2 - The following paper addresses an analytical derivation of a so-called span reduction factor considering the correlation of wind acting on wide spanning overhead transmission line conductors. This load case contributes significantly to the estimation of the total wind load on the towers in particular. With the aid of full scale measurements as well as simulations, the underlying assumptions are reviewed and validated. Finally the results are compared and evaluated with applicable standards. T2 - 14. Dreiländertagung D-A-CH 2015 - Windingenieurtechnik - Vom Bauteilnachweis bis zum Stadtklima CY - Braunschweig, Germany DA - 05.10.2015 PY - 2015 SN - 3-928909-13-4 N1 - Serientitel: WtG-Berichte – Series title: WtG-Berichte IS - 14 SP - 109 EP - 119 AN - OPUS4-34543 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Maierhofer, Christiane A1 - Röllig, Mathias A1 - Steinfurth, Henrik A1 - Meinhardt, J. A1 - Arnold, T. T1 - Untersuchung sicherheitsrelevanter Ablösungen von Fassadenelementen mit aktiver Thermografie N2 - Die Bewertung des Zustandes und der Haftung von Putz und Fassadenelementen auf den darunterliegenden Bauwerksstrukturen ist eine häufig auftretende Fragestellung bei der Erhaltung und Instandsetzung von Bauwerken und Baudenkmälern. Hier müssen nicht nur wirtschaftliche und denkmalpflegerische, sondern auch sicherheitsrelevante Aspekte berücksichtigt werden. Fehlstellen und Ablösungen können, auch wiederholend, mit hoher Nachweisempfindlichkeit mit aktiven Thermografieverfahren geortet und unter bestimmten Voraussetzungen quantitativ bewertet werden. Dazu wird der zu untersuchende Bereich zunächst kurzzeitig (mehrere Minuten lang) erwärmt und anschließend die Abkühlung mit einer Infrarotkamera aufgezeichnet. Systematische Untersuchungen an Probekörpern mit einer Vielzahl unterschiedlicher Fehlstellen unterhalb von Kalkputz, Fliesen und Klinkerriemchen zeigen, dass die Fehlstellen sowohl mittels künstlicher Erwärmung durch einen Infrarotstrahler als auch mittels natürlicher Erwärmung durch die Sonne detektiert und charakterisiert werden können. --------------------------------------------------------------------------------------------------------------------------------------- The evaluation of condition and adhesion of plaster and façade elements to the underlying building structure is a common issue in the maintenance and repair of buildings and monuments. Here not only economic and preservation, but also safety relevant aspects have to be considered. Voids and delaminations can be detected repeatedly with high sensitivity using active thermography methods. Under certain conditions, also a quantitative evaluation is possible. The area under investigation has to be heated up for a short time (up to several minutes). Subsequently, the cooling down is recorded using an infrared camera. Systematic studies on test specimens with a variety of defects below lime plaster, tiles and brick tiles show that the defects can be detected and even characterized both by means of artificial heating using an infrared heater, as well as by natural solar heating. KW - Zerstörungsfreie Prüfung KW - Aktive Thermografie KW - Sonnenerwärmung KW - Fassade KW - Putz KW - Klinkerriemchen KW - Fliese KW - Fehlstelle KW - Ablösung KW - Non-destructive testing KW - Active thermography KW - Heating using solar radiation KW - Facade KW - Plaster KW - Brick tile KW - Tile KW - Void KW - Delamination KW - Bauwerkserhaltung/Sanierung KW - Maintenance and Repair KW - Neue Verfahren/Versuchstechnik KW - New Processes/Experimental Techniques KW - Qualitätssicherung KW - Quality assurement PY - 2015 DO - https://doi.org/10.1002/bate.201500050 SN - 0932-8351 SN - 1437-0999 SN - 0005-6820 SN - 0341-1052 SN - 0932-6359 VL - 92 IS - 10 SP - 1 EP - 6 PB - Ernst & Sohn CY - Berlin AN - OPUS4-34527 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hohberg, Michaela A1 - Siebler, Daniel A1 - Rohwetter, Philipp T1 - Production process and characterization of sensitized all elastomeric POF N2 - We present the production process and characterization of a fluorescent functionalized elastomeric polymer optical fiber (E-POF) consisting of a covalently linked interface between fiber core and fiber cladding. This all silicone rubber E-POF shows increased temperature stability and can be used for sensing applications. Due to the sophisticated production process surface roughness of the interface of fiber core - fiber cladding are even lower than of the thermoplastic tubing template. Total fiber lengths can be extended by a "chemical splicing" technique, allowing individual tailoring of fibers while maintaining sufficient elasticity under applied mechanical stress. T2 - POF 2015 - 24th International conference on plastic optical fibers CY - Nuremberg, Germany DA - 22.09.2015 KW - Polymer optical fiber KW - Elastomer KW - Silicone rubber KW - Fluorescence KW - Thermally stable POF KW - Sensitized POF KW - Chemical splicing PY - 2015 SP - 91 EP - 94 AN - OPUS4-34532 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Petrov, Sergej A1 - Neumann, Patrick P. A1 - Werner, Klaus-Dieter A1 - Lazik, D. A1 - Bartholmai, Matthias T1 - Concept for investigating mechanical impacts on distributed subsurface gas monitoring N2 - A multifunctional sensor in line shape was developed and introduced in previous work for measuring of gas concentrations, temperature change, and strain. A current field study focuses on a spatially distributed monitoring of subsurface CO2 gas storage sites in near real time. Mechanical impacts, e.g., caused by construction work, denudation, and seismic activity, can affect the integrity of underground gas storage sites. Thermal or moisture impacts, e.g., caused by weather conditions, can influence the gas distribution behavior. In this paper, we briefly describe the setup of a CO2 injection soil test field. This setup contains actuating elements for the investigation of mechanical and thermal impacts on distributed subsurface gas monitoring. A concept is given for evaluating these impacts and first experimental results are presented. T2 - 32nd Danubia-Adria Symposium on advances in experimental mechanics CY - Starý Smokovec, Slovakia DA - 22.09.2015 PY - 2015 DO - https://doi.org/10.1016/j.matpr.2016.03.060 SN - 2214-7853 VL - 3 IS - 4 SP - 1124 EP - 1128 PB - Elsevier Science CY - Zilina AN - OPUS4-34489 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Neumann, Patrick P. A1 - Ebert, Sebastian A1 - Lazik, D. A1 - Bartholmai, Matthias T1 - Inverse calibration routine for linear soil gas sensors N2 - Gas sensors in linear form based on the measuring principle of gas selective permeability through a membrane were developed and introduced for the detection and quantification of gas concentrations. A current field study focuses on measuring CO2 concentrations for a spatially distributed monitoring of subsurface CO2 gas storage sites in near real time. A 400 m(2) test site and a corresponding laboratory system were built up to characterize, validate, and optimize the sensor. A calibration routine was developed, which can be applied subsequently to underground installation. First measurement results indicate the potential of the method. T2 - 32nd Danubia-Adria Symposium on advances in experimental mechanics CY - Starý Smokovec, Slovakia DA - 22.09.2015 PY - 2015 SN - 978-80-554-1094-4 DO - https://doi.org/10.1016/j.matpr.2016.03.051 SP - 68 EP - 69 CY - Zilina AN - OPUS4-34491 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Selleng, Christian A1 - Fontana, Patrick A1 - Meng, Birgit T1 - Thermal treatment of ultra-high performance concrete N2 - Ultra-high performance concrete (UHPC) is characterized by outstanding compressive strength of more than 150 MPa, double of normal concrete. Furthermore UHPC has a very dense structure which leads to an extremely low permeability for fluids resulting in with a very high durability. Further structural improvement can be achieved with thermal treatment of UHPC. Recent studies have shown that an increase in compressive strength of more than 50% is possible. Nevertheless, the accurate conditions for an optimal thermal treatment are still not determined. A multitude of parameters can be varied: Temperature, pressure, water saturation, duration of the process steps. Primary object of this study is the optimization of the conditions for thermal treatment focused to the treatment duration at a defined temperature and pressure (185°C / 1,1MPa). Therefore, the thermally treated UHPC samples are analysed by mean of mechanical properties and phase composition. The development of phases and strength at higher temperature differs fundamentally from other cementitious systems (like normal concrete or autoclaved aerated concrete), although the chemical composition is similar. Because of the very dense structure and the low water/cement ratio the availability of water is low. This influences the hydration process. As a consequence tobermorite is absent in thermal treated UHPC in contrast to thermally treated normal concrete or predictions based on thermodynamic modelling. T2 - GeoBerlin 2015: Dynamic Earth - from Alfred Wegener to today and beyond CY - Berlin, FU Berlin DA - 04.10.2015 PY - 2015 AN - OPUS4-34503 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Selleng, Christian A1 - Gröger, K. A1 - Fontana, Patrick A1 - Meng, Birgit A1 - Altenberger, U. T1 - Effect of 90°C thermal treatment on Ultra-High Performance Concrete N2 - Ultra High Performance Concrete (UHPC) is characterized by high strength and high durability. This is achieved by an optimized grain size distribution, especially within fine grains, and addition of superplasticizer, which allow the reduction of the water/cement ratio in the cement paste and thereby the increase of the density of UHPC. Thermal treatment, i.e. curing at elevated temperature and pressure, contributes to a further increase of compressive strength. The aim of the presented study was to analyze the effect of thermal treatment at 90 ◦C and atmospheric pressure on UHPC samples. Varying factors were the age of the samples when heat treatment started (initial storage time), the duration of heat treatment and the type of heat treatment. It was applied in three ways: 1. treated without any protection, 2. sealed in plastic foil and 3. treated in hot water. Afterwards the samples were analyzed with respect to their mechanical properties and their phase composition. Furthermore, the weight (water absorption) of the samples was observed over 28 days and was correlated with the strength test results. The development of strength depends on the combination of initial storage time and the duration of heat treatment and is also influenced by the type of thermal treatment. The highest compressive strengths have been observed by implementing the hot water treatment. Thereby the weight of the samples increase due to additional absorbed water. This enables an increased hydration of cement clinker inducing a higher strength. T2 - GeoBerlin 2015: Dynamic Earth - from Alfred Wegener to today and beyond CY - Berlin, FU Berlin DA - 04.10.2015 PY - 2015 AN - OPUS4-34504 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schnell, A. A1 - Rübner, Katrin A1 - Ludwig, H.-M. ED - Ludwig, H.-M. T1 - Herstellung von Leichtgranulaten aus mineralischen Reststoffen für die Anwendung in Leichtbetonen und Mörteln N2 - Bei mineralischen Bauabfällen und industriellen Reststoffen sind mit zu Heterogenität und Feinheit der Materialien auch die größten Verwertungsdefizite zu verzeichnen. Mangels geeigneter Trenn- und Sortierverfahren stellt eine stoffliche Verwertung im Prozess "Aufbaukörnungen" insbesondere für die feinen Fraktionen Alternative dar. Die Eignung von Mauerwerkbruch mit unterschiedlichen Zusammensetzungen für die Herstellung von Aufbaukörnungen wurde nachgewiesen. Testreihen im Labor und unter Praxisbedingungen in einem Betonwerk zeigen, dass die Eigenschaften von Leichtbetonen mit Aufbaukörnungen als leichte Gesteinskörnung mit denen herkömmlicher Leichtbetone hervorragend vergleichbar sind. Im Rahmen eines aktuellen Forschungsprojekts werden die Eignungsuntersuchungen von thermisch porosierten Leichtgranulaten für den Einsatz in Leichtbetonen -mörteln vertieft. Unter Einsatz der Leichtgranulate sollen Sonderbetone zur Herstellung von Leichtbetonelementen konzipiert werden. In Restauriermörteln und Steinersatzmassen für die Denkmalpflege sollen hingegen insbesondere die fein Leichtgranulate mit Korngrößen < 2 mm eingesetzt. werden. T2 - 19. Ibausil - Internationale Baustofftagung CY - Weimar, Germany DA - 16.09.2015 KW - Leichtgranulat KW - Mauerwerkbruch KW - Mineralischer Reststoff KW - Leichtbeton KW - Restauriermörtel PY - 2015 SN - 978-3-00-050225-5 VL - 2 SP - 2-259 EP - 2-266 AN - OPUS4-34877 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Adolphs, Jürgen A1 - Rübner, Katrin A1 - Schnell, A. A1 - Prinz, Carsten A1 - Peplinski, Burkhard A1 - Hempel, S. ED - Ludwig, H.-M. T1 - Porenstruktur hydrothermal erhärteter Granulate aus Mauerwerkbruch N2 - Die Herstellung hydrothermal erhärteter Granulate ist eine Möglichkeit zur Wiederverwertung von ziegelhaltigem Mauerwerkbruch, der derzeit aufgrund der heterogenen Zusammensetzung und hoher Feinanteile ein besonders hohes Verwertungsdefizit aufweist. Dabei ist die hydrothermale Erhärtung in einem Autoklav bei 200 °C und 1.6 MPa in gesättigter Wasserdampfatmosphäre eine Alternative mit geringerem Energieverbrauch im Vergleich zur thermischen Herstellung von Leichtgranulaten aus mineralischen Abfällen (Blähgranulate) oder Tonen und Schiefer (kommerzieller Blähton bzw. Blähschiefer), die bei Temperaturen von 1200-1300 °C im Drehrohrofen erfolgt. Die Festigkeit der Hydrothermalgranulate entwickelt sich bei diesem Prozess durch die Ausbildung von Calciumsilicathydrat-Phasen (CSH), die durch die Reaktion zwischen Quarzpartikeln und hydratisiertem Kalk entstehen. Die so erzeugten Hydrothermalgranulate haben Rohdichten zwischen 1500 kg/m3 und 2000 kg/m3. Damit und auch durch andere Eigenschaften unterscheiden sie sich von den thermisch erhärteten Blähgranulaten bzw. Blähtonen. Ursache dafür ist letztendlich eine sehr unterschiedliche Gefüge- und Porenstruktur. Im vorliegenden Beitrag wird hauptsächlich über die Ergebnisse der Mikrostrukturuntersuchungen an Hydrothermalgranulaten zusammen mit ihren technologischen Eigenschaften, wie Kornfestigkeit, Rohdichte und Wasseraufnahme, berichtet. T2 - 19. Ibausil - Internationale Baustofftagung CY - Weimar, Germany DA - 16.09.2015 KW - Leichtgranulat KW - Mauerwerkbruch KW - Hydrothermale Herstellung KW - Mikrostruktur KW - Porenstruktur PY - 2015 SN - 978-3-00-050225-5 VL - 2 SP - 2-291 EP - 2-298 AN - OPUS4-34878 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Sturm, Patrick A1 - Gluth, Gregor A1 - Brouwers, H.J.H. A1 - Kühne, Hans-Carsten ED - Ludwig, H.-M. T1 - Structural investigations on one-part geopolymers with different chemical composition N2 - Geopolymers are promising alkali activated materials with a wide range of possible applications like heat-resistant coatings and adhesives or concretes with lower C02 emissions than conventional Portland cement-based systems. Conventional ("two-part") geopolymers are synthesized by an activation of aluminosilicate feedstocks like metakaolin or blast furnace slags with highly alkaline solutions like sodium hydroxide solutions and/or water glass solutions. A more recent approach are so called one-part geopolymers, where the alkaline activator is provided in solid form, so that only water has to be added to initiate the geopolymerisation reaction. The handling of alkaline solutions is avoided, which possesses several advantages compared to conventional geopolymers, in particular regarding safety and health issues, and, thus, it improves economic and social acceptance of these binders. However, the new formulations are less exhaustively studied and the knowledge about conventional geopolymers cannot simply be transferred to this new class of binders. T2 - 19. Ibausil - Internationale Baustofftagung CY - Weimar, Germany DA - 16.09.2015 KW - Geopolymers KW - One-part mix PY - 2015 SN - 978-3-00-050225-5 VL - 2 SP - P1.77, 2-857 - 2-864 AN - OPUS4-34880 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Pfeffer, D. A1 - Scholz, Christian A1 - Belly, C. A1 - Wäsche, Rolf A1 - Schlaak, H.F. A1 - Pott, P.P. T1 - Influence of the actuation waveform on the performance of piezoelectric stick-slip actuators N2 - Performance and efficiency of piezo-electric stick-slip actuators are dependent on the waveform of the electrical actuation of the piezo-stack. This paper compares between a conventional saw-tooth actuation with two waveforms that feature softer acceleration in order to minimize the duration of the slip-phase. It is shown that the proposed waveforms increase both maximum mechanical output power (by 43%) and overall efficiency (by 25%) of the examined actuator. T2 - IKMT 2015 - Innovative Klein- und Mikroantriebstechnik CY - Köln, Germany DA - 14.09.2015 PY - 2015 SN - 978-3-8007-4072-7 N1 - Serientitel: ETG-Fachbericht – Series title: ETG-Fachbericht VL - 146 SP - 100 EP - 104 AN - OPUS4-34883 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Woydt, Mathias A1 - Mohrbacher, H. T1 - Influence of stoichiometry and processing on the tribological profile of hardmetals based on niobium carbide (NbC) N2 - The tribological behavior under dry sliding of a Fe3Al-NbC composite prepared by pyro-metallurgical synthesis is compared to different SPS sintered NbC-based hardmetals bonded by cobalt or Fe3AI. The dry sliding wear resistance (0. 1-7 /10 m/s) of the present Fe3Al-NbC with -60 % NbC was close to those known ofNbC-based hard metals. No grain pull-outs or fragmentations of the NbC grains were seen in the wear tracks of the Fe3Al-NbC composite, as a metallurgical interphase was formed between matrix and NbC grains. The physical prope1ties of melt grown NbC match those known from powder metallurgically sintered NbC using powders converted from Nb205. T2 - International conference on powder metallurgy & particulate materials 2015 CY - San Diego, USA DA - 17.05.2015 PY - 2015 SN - 978-1-943694-01-3 SP - 08-83 EP - 08-91 CY - Princeton, NJ, USA AN - OPUS4-34884 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Rosenthal, Martina A1 - Müller, Christina A1 - Kanzler, Daniel T1 - Webseiten zum 6th European-American workshop on reliability of NDE N2 - Website for 6th European-American Workshop on Reliability of NDE in Munich, 26-29 July 2015 T2 - 6th European-American Workshop on Reliability of NDE CY - Minneapolis, MN, USA DA - 26.07.2015 PY - 2015 UR - http://www.nde-reliability.com UR - http://www.pod-tutorial.nde-reliability.com SP - 1 EP - 12 AN - OPUS4-34919 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Mitzscherling, Steffen A1 - Cui, Q. A1 - Koopman, W. A1 - Bargheer, M. T1 - Dielectric function of two-phase colloid-polymer nanocomposite N2 - The plasmon resonance of metal nanoparticles determines their optical response in the visible spectral range. Many details such as the electronic properties of gold near the particle surface and the local environment of the particles influence the spectra. We show how the cheap but highly precise fabrication of composite nanolayers by spin-assisted layer-by-layer deposition of polyelectrolytes can be used to investigate the spectral response of gold nanospheres (GNS) and gold nanorods (GNR) in a self-consistent way, using the established Maxwell–Garnett effective medium (MGEM) theory beyond the limit of homogeneous media. We show that the dielectric function of gold nanoparticles differs from the bulk value and experimentally characterize the shape and the surrounding of the particles thoroughly by SEM, AFM and ellipsometry. Averaging the dielectric functions of the layered surrounding by an appropriate weighting with the electric field intensity yields excellent agreement for the spectra of several nanoparticles and nanorods with various cover-layer thicknesses. PY - 2015 DO - https://doi.org/10.1039/c5cp04326c SN - 1463-9076 SN - 1463-9084 VL - 17 IS - 44 SP - 29465 EP - 29474 PB - The Royal Soc. of Chemistry CY - Cambridge AN - OPUS4-34920 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Harsha, A.P. A1 - Wäsche, Rolf A1 - Hartelt, Manfred T1 - Friction and wear studies of polyetherimide composites under oscillating sliding condition against steel cylinder N2 - Tribological properties of neat polyetherimide (PEI), glass, carbon fiber, and solid lubricants filled PEI composites are presented in this article. The aim of this study was to investigate the friction and wear properties of these composites under dry oscillating sliding condition at room temperature (RT) as well as at elevated temperature (120 °C). The polymer specimens were made to oscillate against steel cylinder as a counterpart. The friction and wear properties of PEI and composites were strongly influenced by the temperature. Incorporation of carbon fiber in the PEI matrix has increased the wear rate at RT, while at elevated temperature this trend was opposite. Abrasive action of carbon fibers has severely damaged the counterpart and resulted in accelerated wear of the composite at RT. Solid lubricants filled (PTFE, MoS2, graphite) along with glass fiber is beneficial in improving the friction and wear performance of the PEI composite at RT, whereas at elevated temperature wear performance was deteriorated. Tribological performance of neat PEI and glass fiber composite was similar with each other at RT. Scanning electron micrographs and optical micrographs of the worn polymer specimens and the steel cylinders was used to study the possible wear mechanisms. The present test results were also compared with data available on the reciprocating wear of PEI and composites in the literature and trends have been reported. PY - 2015 DO - https://doi.org/10.1002/pc.23559 SN - 0272-8397 SN - 1548-0569 VL - 38 IS - 1 SP - 48 EP - 60 PB - Society of Plastics Engineers CY - Manchester, NH AN - OPUS4-34921 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Müller, P. A1 - Mielke, Johannes A1 - Hodoroaba, Vasile-Dan A1 - Kägi, R. A1 - Ryner, M. T1 - Assessment of different electron microscopy techniques for particle size quantification of potential nanomaterials N2 - While nano-scaled intermediate and consumer products are omnipresent in many industries, one challenge consists in the development of methods that reliably identify, characterize and quantify nanomaterials both as a substance and in various matrices. For product registration purposes, the European Commission proposed a definition for nanomaterial which requires a quantitative size determination of the primary particles in a sample down to sizes of 1 nm. According to a material is defined as nano if 50% of the primary particles are observed to comprise a smallest dimension <100 nm. The NanoDefine project was set up to develop and validate a robust, readily implementable and cost-effective measurement approach to obtain a quantitative particle size distribution and to distinguish between nano and non-nano materials according to the definition Among the available particle sizing techniques, electron microscopy was found to be one option meeting most of the requirements of the regulation. However, the use of electron microscopy for particle sizing is often limited by cost per sample, availability in industry, particle agglomeration/aggregation, extremely broad size distributions, 2D materials and operator bias in case of manual evaluation. PY - 2015 DO - https://doi.org/10.1017/S1431927615012799 SN - 1431-9276 SN - 1435-8115 VL - 21 IS - Suppl. 3 SP - Paper 1200, 2403 EP - 2404 PB - Cambridge University Press CY - New York, NY AN - OPUS4-34922 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Mielke, Johannes A1 - Rades, Steffi A1 - Ortel, Erik A1 - Salge, T. A1 - Hodoroaba, Vasile-Dan T1 - Improved spatial resolution of EDX/SEM for the elemental analysis of nanoparticles N2 - The interest in nanoparticles remains at a high level in fundamental research since many years and increasingly, nanoparticles are incorporated into consumer products to enhance their performance. Consequently, the accurate and rapid characterization of nanoparticles is more and more demanded. Electron microscopy (SEM, TSEM and TEM) is one of the few techniques which are able to image individual nanoparticles. It was demonstrated recently that the transmission electron microscopy at a SEM can successfully be applied as a standard method to characterize accurately the size (distribution) and shape of nanoparticles down to less than 10 nm. PY - 2015 DO - https://doi.org/10.1017/S1431927615009344 SN - 1431-9276 SN - 1435-8115 VL - 21 IS - Suppl. 3 SP - Paper 0855, 1713 EP - 1714 PB - Cambridge University Press CY - New York, NY AN - OPUS4-34923 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Pfennig, Anja A1 - Schiz, J. A1 - Kranzmann, Axel ED - Jha, A. ED - Wang, C. ED - Neelameggham, N.R. ED - Guillen, D.P. ED - Li, L. ED - Belt, C.K. ED - Kirchain, R. ED - Spangenberger, J.S. ED - Johnson, F. ED - Gomes, A.J. ED - Pandey, A. ED - Hosemann, P. T1 - The role of austenitizing routines of pipe steels during CCS N2 - Properties of pipe steels for CCS technology require resistance against the corrosive environment of a potential CCS-site (heat, pressure, salinity of the aquifer, CO2-partial pressure). The influence of austenitizing in heat treatment routines of two different injection pipe steels (1.4034, X46Cr13 and 1.4021, X20Cr13) was evaluated. Steel coupons were austenitized at different temperatures (900 – 1050 °C) for different lengths of time (30–90 min) before quenching and annealing prior to long term corrosion experiments (60°C, 100 bar, artificial brine close to a CCS-site in the Northern German Basin, Germany). In general, fewer pits are found on X46Cr13. Comparing steels with 13% chromium each the higher carbon content of X46Cr13 (0.46% C) results in a lower number of pits compared to X20Cr13 (0.20% C). It is found that neither the carbon content of the steels nor austenitizing temperature has much influence, but local corrosion behaviour is most susceptible towards austenitizing time KW - Corrosion KW - CCS KW - Carbon storage KW - Aquifer KW - Austenitizing PY - 2015 SN - 978-1-119-08240-8 DO - https://doi.org/10.1002/9781119093220.ch15 SP - 131 EP - 137 PB - Wiley AN - OPUS4-34924 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Baier, Jennifa A1 - Beck, Uwe A1 - Hidde, Gundula A1 - Hielscher, Stefan A1 - Lange, Thorid A1 - Mix, Renate T1 - Plasmagestützte Oberflächenfunktionalisierung von Polypropylen (PP) N2 - Polypropylen (PP) ist als Niedrigenergie-Polymer ohne nass- und plasmachemische Vorbehandlung weder haftfest zu beschichten noch verbundfest zu kleben. Typische Haft- bzw. Klebfestigkeiten liegen für die unbehandelte Polymeroberfläche bei maximal 0,5 MPa. Hinzu kommt, dass bei der Bestimmung von Haft- und Klebfestigkeiten der unmodifizierten Oberfläche mit großen Streuungen zu rechnen ist, die bezogen auf die Spannweite durchaus einem Faktor 5 entsprechen können. Generell besteht bei Prüfung der Haftfestigkeit mittels Stirnabzugsversuch und bei der Prüfung der Klebfestigkeit die Notwendigkeit eines statistisch validierten Herangehens. Hierzu sind zeitaufwändige Ein-Proben-Klebungen und -Prüfungen nur eingeschränkt geeignet. Zudem ist, insbesondere für geringe Haft- bzw. Klebfestigkeiten, ein querkraftfreies Prüfen Grundvoraussetzung. Im vorliegenden Beitrag werden verschiedenartige plasmagestützte Oberflächenfunktionalisierungen von PP sowie das Mehr-Proben-Konzept zur Klebung/Prüfung von bis zu acht Proben vorgestellt. Dazu werden ein BAM-Funktionsmuster einer Mehr-Proben-Kleb-Vorrichtung und eine kommerzielle analytische Zentrifuge zum Prüfen verwendet. T2 - 24. Workshop des Anwenderkreises Atmosphärendruckplasma "Haftung durch Oberflächenfunktionalisierung" CY - Erfurt, Germany DA - 11.11.2015 KW - Plasmamodifizierung KW - Polypropylen KW - Haftfestigkeit KW - Klebfestigkeit KW - Mehr-Proben-Kleben/-Prüfen PY - 2015 SP - 1 EP - 6 PB - Anwenderkreis Atmosphärendruckplasma CY - Jena AN - OPUS4-34838 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Auersch, Lutz A1 - Said, Samir T1 - Methods and phenomena of single and coupled floor vibrations - Measurements in apartment and office buildings N2 - A survey of the phenomena and methods for floor vibrations is presented. Experimental results of floor vibrations are shown for many floors in six different buildings. The signals have been evaluated for waves and modes by simple procedures. General rules have been established between the material and the area of a specific floor, and its local eigenfrequency. The damping values of the floor vibrations have been found between D = 1 and 10 % where somewhat higher values have been measured for wooden floors, and a weak correlation with the eigenfrequency has been established. The velocities of bending waves propagating in a storey and the attenuation with distance in the building have been analysed. A considerable transfer of vibration from one room to far away parts of the building has been found in the studied buildings with concrete and wooden floors. An example building has been analysed for modes of coupled floor bays. The strong coupling of similar neighbouring floor bays would yield a wide band of global resonance frequencies. The measured wooden floor exhibits a weak coupling of the neighbouring floor bays and a narrower band of eigenfrequencies. A special method has been tested with the impulse measurements to estimate the coupled eigenmodes in presence of the high damping. From the ambient measurement, a low-frequency vibration mode has been detected which includes the vibration of the whole building and the soil. The coupling of floors to other floors and the whole building is an important phenomenon of structural dynamics which should be observed for the prediction of vibration due to internal and external sources. PY - 2015 SN - 1351-010X VL - 22 IS - 2 SP - 81 EP - 108 PB - Multi-Science Publ. Co. CY - Brentwood AN - OPUS4-34839 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Schempp, P. A1 - Rethmeier, Michael T1 - Understanding grain refinement in aluminium welding N2 - Grain refinement is an important opportunity to improve mechanical properties of fusion welds and the weldability (susceptibility to solidification cracking) of the base metal. In this study, grain refinement was achieved in aluminium welds through additions of grain refiner to the weld metal. Increasing grain refiner additions led to a decrease of the weld metal mean grain size (down to −86 %). The grain refinement efficiency was the highest in commercial pure Al (Alloy 1050A, Al 99.5), followed by Alloy 6082 (Al Si1MgMn) and Alloy 5083 (Al Mg4.5Mn0.7). To investigate this clear influence of alloy content on grain size, the undercooling parameters P and Q were calculated. Temperature measurements revealed that solidification parameters such as solidification growth rate or cooling rate vary significantly along the solidification front, dependent upon torch speed and alloy. On the basis of this comparison, an analytical approach was used to model the columnar to equiaxed transition (CET). Moreover, wavelength dispersive X-ray spectroscopy (WDS) and transmission electron microscopy (TEM) analyses revealed particles rich in Ti and B that are probably TiB2 particles coated by Al3Ti nucleating Al grains during solidification. Also, Ti/B contents needed in commercial filler wires to allow optimum weld metal grain refinement were calculated dependent upon base alloy and welding process. PY - 2015 DO - https://doi.org/10.1007/s40194-015-0251-2 SN - 0043-2288 SN - 1878-6669 VL - 59 IS - 6 SP - 767 EP - 784 PB - Springer CY - Oxford AN - OPUS4-34840 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Polami, S.M. A1 - Häfele, P. A1 - Rethmeier, Michael A1 - Schmid, A. T1 - Study on fatigue behavior of dissimilar materials and different methods of friction-welded joints for drive pinion in trucks N2 - This work addresses the fatigue strength of friction-welded joints for the drive pinion in heavy-duty trucks. Three different friction welding (FW) variants were tested for the joint between the pinion and the bevel of the shaft: (1) conventional FW using series materials, (2) conventional FW from dissimilar materials for every part, and (3) dissimilar joints by applying joint-site structure of FW. Each joint variant was compared to the series production part using a 4-point bending test. Results showed that the higher strength material slightly improved the fatigue strength of the conventional friction-welded joints. Despite the light weight of the component joined structurally at the site, the joint revealed a lower endurance limit compared to other variants. However, there has been little discussion on the weld zone position. The applied equivalent stresses on the weld zone of the joint-site structure are less similar to the position for the conventional FW. Characterization of the failure explains the extraordinary behaviors in relation to S-N curves. PY - 2015 DO - https://doi.org/10.1007/s40194-015-0258-8 SN - 0043-2288 SN - 1878-6669 VL - 59 IS - 6 SP - 917 EP - 926 PB - Springer CY - Oxford AN - OPUS4-34841 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Woydt, Mathias A1 - Mohrbacher, H. T1 - The background for the use of hardmetals and MMCs based on niobium carbide (NbC) as cutting tools and for wear resistant tribosystems N2 - In this present study, the mechanical properties (strength, hardness, moduli) and the dry sliding properties of stoichiometric and sub-stoichiometric NbC were compared. Microhardness and elastic properties of NbC depend from the C/Nb ratio, because the binary phase diagram Nb-C shows a region of homogeneity of NbCx of 0,72≤ x ≤1.0. At RT, hard metals of stoichiometric NbC have an elastic modulus E of ~440 GPa, those of substochiometric NbC0,88 an E of 405 GPa. The hot hardness of sub-stoichiometric NbC is above 600°C higher than of WC. The dry sliding wear resistance (0,1-7/10 m/s) of the present Fe3Al-NbC0,94 with ~61 vol.-% NbC as hard phase was close to those known of NbC-based hard metals. No grain pull-outs or fragmentations of the NbC grains were seen in the wear tracks of the Fe3Al-NbC composite (MMC), as a metallurgical interphase was formed between matrix and NbC grains. Stoichiometric and sub-stoichiometric niobium carbides have at RT and 400°C under dry sliding a prone intrinsic wear resistance more or less independent from sliding speed, either as hardmetal or as hard phase in metal matrix composite, associated with an exceptional high load carrying capacity. T2 - 3rd International Conference on Stone and Concrete Machining (ICSCM) CY - Bochum, Germany DA - 02.11.2015 KW - NbC KW - Niobium carbide KW - Cobalt KW - Fe3Al KW - Hardmetals KW - Metal matrix composite KW - Wear resistance KW - Cutting KW - Milling PY - 2015 SN - 978-3-943063-20-2 SP - 199 EP - 207 PB - Ruhr-Universität Bochum CY - Bochum AN - OPUS4-34846 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Fischer, Franziska A1 - Joester, Maike A1 - Rademann, K. A1 - Emmerling, Franziska T1 - Survival of the fittest: competitive co-crystal reactions in the ball mill N2 - The driving forces triggering the formation of co-crystals under milling conditions were investigated by using a set of multicomponent competitive milling reactions. In these reactions, different active pharmaceutical ingredients were ground together with a further compound acting as coformer. The study was based on new co-crystals including the coformer anthranilic acid. The results of the competitive milling reactions indicate that the formation of co-crystals driven by intermolecular recognition are influenced and inhibited by kinetic aspects including the formation of intermediates and the stability of the reactants. PY - 2015 DO - https://doi.org/10.1002/chem.201500925 SN - 0947-6539 SN - 1521-3765 VL - 21 IS - 42 SP - 14969 EP - 14974 PB - Wiley-VCH Verl. CY - Weinheim AN - OPUS4-34861 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Weise, Frank A1 - Voland, Katja A1 - Meng, Birgit ED - Ludwig, H.-M. T1 - AKR unter kombinierten Einwirkungen - Rissbildungs- und Transportmechanismen N2 - ln den letzten Jahren sind im deutschen Bundesautobahnnetz verstärkt Schäden an Betonfahrbahndecken aufgetreten, die mit einer Alkali-Kieselsäure-Reaktion (AKR) in Verbindung gebracht werden. Die damit einhergehende oft drastische Reduzierung der Nutzungsdauer der Betonfahrbahndecke führte zu einer starken Intensivierung der Forschung auf diesem Gebiet. Zentraler Forschungsgegenstand war bisher neben der Suche nach geeigneten präventiven betontechnologischen Maßnahmen vor allem die Entwicklung performanceorientierter Prüfverfahren zur AKR-Prävention. Dabei wurden insbesondere die klimatischen Einwirkungen auf die Betonfahrbahndecke und der externe Alkalieintrag zeitraffend simuliert. Die zusätzlich interagierenden mechanischen Einwirkungen aus dem Verkehr fanden bisher keine Berücksichtigung. Vor diesem Hintergrund verfolgt die 2011 eingerichtete und 2015 um weitere drei Jahre verlängerte DFG-Forschergruppe 1498 u. a. das Ziel, den Einfluss einer mechanisch induzierten Vorschädigung (Ermüdungsbeanspruchung) auf den AKR-Schädigungsprozess zu klären. Die hierfür erforderliche Beschreibung der vielfältigen interagierenden Schädigungs- und Transportprozesse erfordert eine enge Verknüpfung von Experimenten mit einer mehrskaligen Modellierung. Die experimentelle Basis bildet die mechanische Vorschädigung (Ermüdung) großformatiger Balken aus einem Fahrbahndeckenbeton mit einem erhöhten AKR-Schädigungspotenzial. Aus diesen Balken werden nach der Ermüdungsbeanspruchung kleinformatige Probekörper gewonnen, an denen die Auswirkungen der mechanischen Vorschädigung auf das Betongefüge und die interagierenden Transport- und Schädigungsprozesse analysiert werden. Das Teilprojekt der SAM hat in diesem Kontext die Aufgabe, ganzheitlich die Rissbildungsprozesse und den interagierenden Eintrag bzw. Auslaugung der Alkalien von der mechanisch induzierten Vorschädigung bis zum AKR-Schädigungsprozess in enger Abstimmung mit den Forschungspartnern zu untersuchen. Den Schwerpunkt dieses Beitrags bildet die Charakterisierung der Rissbildungsprozesse durch die mechanische Vorschädigung und ihrer Auswirkungen auf die interagierenden Transportprozesse. Das schließt die Vorstellung der hierfür angewandten innovative Prüftechniken und Prüfmethodologien ein. T2 - 19. Ibausil - Internationale Baustofftagung CY - Weimar, Germany DA - 16.09.2015 KW - Betonfahrdecke KW - Ermüdung KW - Transportprozess KW - Ultraschall KW - Schallemissionsanalyse KW - Computertomografie KW - Laser-induced breakldown spectroscopy PY - 2015 SN - 978-3-00-050225-5 VL - 1 SP - 1 - 1461 EP - 1 - 1471 AN - OPUS4-34864 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Barthel, Maria A1 - Peplinski, Burkhard A1 - Rübner, Katrin ED - Ludwig, H.-M. T1 - Synthese hydraulischer Phasen in Papierasche und Braunkohlenflugasche durch hydrothermale Behandlung N2 - Reststoffe aus industriellen Filter- und Verbrennungsprozessen, die in ihren Hauptbestandteilen aus Si02- und CaO-reichen Mineralphasen bestehen, besitzen das Potential hydraulische Eigenschaften auszubilden. Das bedeutet, dass sie in Anwesenheit von Wasser oder alkalischen Lösungen festigkeitsbildende Phasen entwickeln. Oft bedarf es zunächst einer Aufbereitung um die hydraulischen Mineralphasen zu aktivieren. Hydraulische Phasen sind z.B. die Calciumsilikate Alit (C3S) und Belit (C2S). Sie unterscheiden sich vorrangig durch ihr Ca/Si-Verhältnis. Im Allgemeinen hydratisiert Belit langsamer als Alit und das Hydratationsprodukt weist nach 28 Tagen eine geringere Festigkeit auf. Zur Herstellung von Belit wird weniger Calciumoxid benötigt als zur Herstellung von Alit. Daher muss weniger CaC03 kalziniert werden und der C02-Ausstoß bei der Produktion verringert sich. Zur Synthese von hydraulisch aktivem Belit kann eine hydrothermale Aufbereitung dienen. Verschiedene Autoren nutzten diese Behandlung zur Aktivierung verschiedener Reststoffe, wobei sich CaO-reiche Asche aus der Energieerzeugung (z.B. Braunkohlenflugasche) als sehr geeignet erwies, Papierasche (PA) aus dem Papierrecyling besitzt ebenfalls einen hohen CaO-Gehalt und ist Bestandteil der aktuellen Bindemittelforschung auf Reststoffbasis. Die Untersuchung einer hydrothermalen Aktivierung fehlt bisher. Dieser Artikel soll einen Beitrag zur Klärung der folgenden Fragen leisten: Eignet sich Papierasche zur Belitsynthese durch hydrothermale Behandlung? Wie entwickeln sich die Mineralphasen im Vergleich zur Braunkohlenflugasche? T2 - 19. Ibausil - Internationale Baustofftagung CY - Weimar, Germany DA - 16.09.2015 KW - Reststoffe KW - Papierasche KW - Braunkohlenflugasche KW - Bindemittel KW - XRD PY - 2015 SN - 978-3-00-050225-5 VL - 1 SP - 1-1011 EP - 1-1018 AN - OPUS4-34870 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Vogler, Nico A1 - Barthel, Maria A1 - Leinitz, Sarah A1 - Kühne, Hans-Carsten ED - Ludwig, H.-M. T1 - Nachweis der Funktionalität von modifizierten Betonpflastersteinen N2 - In urbanen Zentren schreitet die Versiegelung von Oberflächen voran. Ursache ist die stetige Zunahme moderner Infrastruktur. Straßen und Plätze heizen sich stärker auf und begünstigen die Entstehung von Hitzeinseln (Urban Heat Island Effect). Dies wirkt sich zunehmend negativ auf die Lebensqualität innerhalb dieser Städte aus. Einen möglichen Lösungsansatz zur Abschwächung dieses Effekts bietet die Entwicklung von Betonpflastersteinen mit erweiterten Leistungsmerkmalen. Der Einsatz von wasserspeichernden Materialien kann zur Verringerung der Oberflächentemperatur durch Ausnutzung von Verdunstungskälte einen Beitrag leisten. Die speziellen Anforderungen an die Pflastersteine bedürfen genauerer Untersuchungen, wobei diese über den Umfang der Standardprüfungen hinausgehen und eine entsprechende Anpassung der Messtechnik zum Nachweis der Wirksamkeit erforderlich machen. Da die selbstkühlenden Pflastersteine nach dem Prinzip der Verdunstung arbeiten, ist sowohl die Fähigkeit der Speicherung als auch die Fähigkeit zur kontinuierlichen Abgabe von Wasser nachzuweisen. Der kühlende Effekt in Bezug auf Oberfläche und Umgebung steht dabei im Vordergrund. Des Weiteren sind Untersuchungen unter verschiedenen klimatischen Bedingungen sowohl unter Laborbedingungen als auch im Freifeldversuch durchzuführen. Die Prüfung der Druckfestigkeit und der kapillaren Wasseraufnahme und des sind ebenfalls Bestandteil der umfangreichen Untersuchungen. Durch den Einsatz von thermischer Messtechnik sowie mechanischer Prüfungen und Untersuchungen zur Dauerhaftigkeit ist es möglich eine Charakterisierung der Pflastersteine vorzunehmen und deren prinzipielle Funktionalität nachzuweisen. In diesem Beitrag werden die verschiedenen Möglichkeiten und die daraus resultierenden Ergebnisse vorgestellt und so Schlüsse zur Funktion und Anwendbarkeit von derartig modifizierten Betonpflastersteinen gezogen. T2 - 19. Ibausil - Internationale Baustofftagung CY - Weimar, Germany DA - 16.09.2015 KW - Modifizierte Betonpflastersteine KW - Dauerhaftigkeit KW - Temperaturverhalten PY - 2015 SN - 978-3-00-050225-5 VL - 24-01 SP - 1-1331 EP - 1-1338 AN - OPUS4-34871 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Lehmann, C. A1 - Meng, Birgit A1 - Nemecek, J. ED - Ludwig, H.-M. T1 - Investigations on the process of autoclaving ultra-high performance concrete (UHPC) N2 - Concrete technology results more and more in the development of materiale with enhanced properties, such as high strength, higher durability and increased ecological compatibility. One exceptional example is Ultra-High Performance Concrete (UHPC). Its advantages are very high compressive strength and an improved durability, caused by their dense micro structure. Curing under water vapor Saturation pressure (autoclaving) can improve these properties by affecting the micro structure and better the mechanical properties of UHPC. Autoclaving leads to an enhanced cement hydration and accelerated reaction rate of supplementary cementitious materials (SCM) and mineral additions, Used at the production of aerated autoclaved concrete (AAC) and sand-lime bricks, the process of autoclaving is well known, especially in highly porous Systems. One well known requirement to autoclave effectively is a porosity of at least 10%. There is no sufficient heat transfer and also not enough water available if the porosity is lower, Nevertheless, autoclaving also works in the dense structure of UHPC with porosities lower than 2%, as former investigations have shown. There is only a visible difference between the outer parts of the samples compared to their core. Investigations on the chemistry, the micro structure as well as the mechanical properties where performed to find an explanation to this effect and to explain the functionality of autoclaving UHPC in spite of the low porosity. T2 - 19. Ibausil - Internationale Baustofftagung CY - Weimar, Germany DA - 16.09.2015 PY - 2015 SN - 978-3-00-050225-5 VL - 2 SP - P2.15, 2-1039 EP - 2-1044 AN - OPUS4-34872 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Rübner, Katrin A1 - Schnell, A. A1 - Peplinski, Burkhard A1 - Zimathies, Annett A1 - Hempel, S. ED - Ludwig, H.-M. T1 - Mikrostrukturelle und mineralogische Eigenschaften leichter Gesteinskörnungen aus Mauerwerkbruch N2 - Poröse RC-Leichtgranulate mit Rohdichten zwischen 600 kg/m³ und 1400 kg/m³ können nach einem mehrstufigen mechanischen Prozess durch thermische Erhärtung bei 1180 °C aus ziegelhaitigern Mauerwerkbruch hergestellt werden. Diese Granulate erfüllen die Anforderungen an leichte Gesteinskörnungen nach DIN EN 13055 und es lassen sich damit Leichtbetone nach DIN EN 206-1/DIN 1045-2 herstellen. Ihre Festigkeits- und Dauerhaftigkeitseigenschatten sind mit denen herkömmlicher Leichtbetone mit Blähtonkörnungen sehr gut vergleichbar. Das ist das Fazit aus dem in den letzten Jahren durchgeführten Verbundforschungsvorhaben "Aufbaukörnungen". Um jedoch die Granulatentstehung bzw. den Vorgang der Porosierung besser verstehen, den Herstellungsprozess optimieren und die Eigenschaften der Granulate maßschneidern zu können, wurden zusätzlich zu den makroskopischen Charakteristika, wie beispielsweise Porosität und Wasseraufnahme, die chemisch-mineralogischen und mikrostrukturellen Eigenschaften der Leichtgranulate untersucht. Dazu dienten Analysen mittels ICP-Emissionsspektrometrie, Röntgenpulverdiffraktometrie, Quecksilberporosimetrie und mikroskopischen Verfahren. Im Beitrag wird über die Ergebnisse der Gefüge- und Porenstrukturuntersuchungen an Leichtgranulaten im Vergleich zu herkömmlichem Blähton berichtet. T2 - 19. Ibausil - Internationale Baustofftagung CY - Weimar, Germany DA - 16.09.2015 KW - Leichte Gesteinskörnungen KW - Mauerwerkbruch KW - Mikrostruktur KW - Porenstruktur PY - 2015 SN - 978-3-00-050225-5 VL - 2 IS - P3.14 SP - 2-1329 EP - 2-1336 AN - OPUS4-34873 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Leinitz, Sarah A1 - Rübner, Katrin A1 - Berger-Tomajer, V. A1 - Chronz, M. A1 - Schnell, A. ED - Ludwig, H.-M. T1 - Einsatz von RC-Leichtgranulaten für Mörtel in der Denkmalpflege N2 - Das Forschungsprojekt "RC-Leichtgranulate" umfasst die Optimierung des Herstellungsprozesses von Leichtgranulaten aus heterogenen und teilweise feinkörnigen Bau- und Abbruchabfällen und Applikationsuntersuchungen dieser Granulate. Aufgrund der großen Verwertungsdefizite von Mauerwerkbruch im Vergleich zu Betonbruch, wird das Hauptaugenmerk auf den Einsatz von Mauerwerkbruch als Ausgangsmaterial für die Leichtgranulate gelegt. Dabei wird das Rohstoffpotential des Mauerwerkbruchs genutzt, das heißt die chemisch-mineralogische Zusammensetzung des Ausgangsmaterials ist von entscheidender Bedeutung. Die Produktion der Leichtgranulate erfolgt durch einen mehrstufigen Herstellungsprozess mit abschließender thermischer Erhärtung. Die Leichtgranulate sollen sowohl im Beton als auch in Spezialmörteln in der Denkmalpflege Anwendung finden. Der vorliegende Beitrag beschäftigt sich mit dem Einsatz von RC-Leichtgranulaten mit Korngrößen kleiner als 2 mm in Restauriermörteln und Steinersatzmassen. In einem ersten Schritt wird eine für Restauriermörtel entwickelte Basismischung mit Natursand im Hinblick auf den Einsatz leichter Gesteinskörnungen modifiziert. Ziel ist es, einen gut verarbeitbaren Leichtmörtel herzustellen, der aber Ähnliche Festigkeiten wie die Basismischung erreicht. Die Anforderungen an die Mörtel, die Mischungszusammensetzungen und die Ergebnisse aus den Frisch- und Festmörtelprüfungen werden vorgestellt. T2 - 19. Ibausil - Internationale Baustofftagung CY - Weimar, Germany DA - 16.09.2015 KW - Leichtgranulat KW - Recycling KW - Restauriermörtel KW - Denkmalpflege PY - 2015 SN - 978-3-00-050225-5 VL - 2 SP - 30-06, 2-141 EP - 2-148 AN - OPUS4-34875 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Ünal, Murat A1 - Hüsken, Götz A1 - Kühne, Hans-Carsten ED - Ludwig, H.-M. T1 - Entwicklung eines PCC-Leichtmörtels zur Instandsetzung einer denkmalgeschützten Sichtbetonfassade N2 - Der Schutz und Erhalt der Originalsubstanz stehen im Mittelpunkt jeglicher denkmalpflegerischer Instandhaltungsmaßnahmen. Das äußere Erscheinungsbild spielt hierbei - im Gegensatz zur klassischen Betoninstandsetzung - eine größere Rolle. Nichtsdestotrotz dürfen die technischen Belange auch hier nicht außer Acht gelassen werden. Die Ermittlung des Ist- und Sollzustands stellt die Grundlage einer dauerhaften Instandsetzung dar. Der vorliegende Beitrag zeigt Schäden und Schadensursachen an einem denkmalgeschützten Gebäude in Leichtbetonbauweise auf. Das Bauwerk wurde hinsichtlich seines Schädigungsgrads, -umfangs und der maßgeblichen Schadensursachen untersucht. Im Rahmen dieser Untersuchungen wurden gehäuft Risse, Abplatzungen und Bewehrungskorrosion festgestellt. Die durch eine Brettschalung strukturierte Sichtbetonfassade soll im Zuge der Instandsetzungsmaßnahme möglichst originalgetreu wiederhergestellt werden. Bei der Auswahl von geeigneten Instandsetzungsmethoden und -produkten konnte aufgrund fehlender Normen und Richtlinien für die Instandsetzung von denkmalgeschützten Leichtbetonbauten nicht auf bereits existierende Produkte und Methoden zurückgegriffen werden. Daher wurde in Anlehnung an die Richtlinie "Schutz und Instandsetzung von Betonbauteilen" (RL SIB) des DAfStB eine polymermodifizierte Betonergänzungsmasse mit leichter Gesteinskörnung entwickelt. Ausgehend von der Hauptschadensursache, der karbonatisierungsinduzierten Bewehrungskorrosion, wurden erforderliche Eigenschaften der Betonergänzungsmasse in enger Absprache mit der zuständigen Denkmalschutzbehörde und dem involvierten Fachplaner abgestimmt. Neben den grundlegenden mechanischen Eigenschaften spielen in diesem Anwendungsfall spezielle Eigenschaften wie z.B. farbliehe Anpassung der Betonergänzungsmasse, Möglichkeit der Oberflächenstrukturierung, Zeitfenster der Verarbeitbarkeit sowie die Modellierbarkeit eine wichtige Rolle. Der entwickelte PCC-Leichtmörtel berücksichtigt dabei auch den Einfluss einer geringen Schwind- und Quellneigung der Betonergänzungsmasse um Delaminierung infolge unterschiedlicher Längenänderungen zu vermeiden und somit eine dauerhafte Instandsetzung zu gewährleisten. Weiterhin wurde das Verbundverhalten des entwickelten PCCL Leichtmörtels für unterschiedliche Schichtaufbauten untersucht. T2 - 19. Ibausil - Internationale Baustofftagung CY - Weimar, Germany DA - 16.09.2015 KW - Concrete-glazing KW - Dalles de verres KW - Cathodic corrosion protection KW - Heritage KW - Restoration KW - Maintenance PY - 2015 SN - 978-3-00-050225-5 VL - 2 SP - 30-04, 2-125 - 2-132 AN - OPUS4-34876 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Neumann, Patrick P. A1 - Bartholmai, Matthias A1 - Lazik, D. T1 - Near real-time reconstruction of 2D soil gas distribution from a regular network of linear gas sensors N2 - A monitoring method is introduced that creates, in near real-time, two-dimensional (2D) maps of the soil gas distribution. The method combines linear gas sensing technology for in-situ monitoring of gases in soil with the mapping capabilities of Computed Tomography (CT) to reconstruct spatial and temporal resolved gas distribution maps. A weighted iterative algebraic reconstruction method based on Maximum Likelihood with Expectation Maximization (MLEM) in combination with a source-by-source reconstruction approach is introduced that works with a sparse setup of orthogonally-aligned linear gas sensors. The reconstruction method successfully reduces artifact production, especially when multiple gas sources are present, allowing the discrimination between true and non-existing so-called ghost source locations. A first experimental test indicates the high potential of the proposed method for, e.g., rapid gas leak localization. T2 - IEEE Sensors 2015 CY - Busan, South Korea DA - 01.11.2015 KW - Distributed linear sensor KW - Membrane-based gas sensing KW - Subsurface monitoring KW - Gas storage areas KW - Computed tomography PY - 2015 SN - 978-1-4799-8202-8 SN - 1930-0395 SP - 1550 EP - 1553 PB - IEEE AN - OPUS4-34849 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kluge, Martin A1 - Kreißig, Michael A1 - Liebner, Christian A1 - Spoormaker, T. T1 - Identifizierung von sicherheitstechnisch gefährlichen Bedingungen für schlagartige Kompressionsvorgänge chemisch instabiler Gase im industriellen Maßstab N2 - Tetrafluorethen wird von der Polymerindustrie seit Jahrzenten als monomeres Ausgangsmaterial sowohl für die Herstellung von Polymeren (PTFE) als auch für Kopolymere (PCTFE) eingesetzt. Aufgrund seiner Eigenschaft als chemisch instabiles Gas kann TFE auch ohne Luftsauerstoff oder einen anderen Oxydator explosionsartig zerfallen. Nach der Initiierung des Zerfalls kann dieser unter bestimmten Bedingungen aufgrund des exothermen Reaktionsverhaltens sich selbstständig in Apparaten und Rohrleitungen ausbreiten. Dies geht aufgrund der freigesetzten Reaktionsenthalpie mit einem schlagartigen Anstieg von Druck und Temperatur einher, was zu erheblichen Belastungen der Materialien bis hin zum Versagen und Bruch und möglichen Folgeschäden einschließlich Personenschäden führen kann und in der Vergangenheit bereits mehrfach geführt hat. Besonders nach Wartungsarbeiten besteht die Gefahr, dass Teilabschnitte im Rohrleitungssystem mit TFE, Stickstoff oder Luft gefüllt sind mit Drücken in einem Bereich zwischen technischem Vakuum und atmosphärischem Druck wohingegen angrenzende Rohrabschnitte oder Behälter immer noch TFE bei Betriebsdrücken bis 32 bar enthalten können. Dabei sind die Abschnitte in der Praxis häufig durch Kugelhähne voneinander getrennt, die aufgrund ihrer Öffnungscharakteristik bereits bei geringen Betätigungswinkeln eine große Querschnittsfreigabe für die Strömung im Rohr ermöglichen. Dadurch können schlagartige Kompressionsvorgänge des Gases im Niederdruckbereich ermöglicht werden, die allein aufgrund der thermodynamischen Zustandsänderung zu einer erheblichen Temperaturerhöhung führen und im schlimmsten Fall zur Initiierung der Zerfallsreaktion führen können. Es wird erstmalig ein Versuchsaufbau im Industriemaßstab, der einer explosionsartigen Zerfallsreaktion von TFE standhalten kann. Zahlreiche Sicherheitskonzepte einschließlich diverser Berstscheibenkonfigurationen als auch zeitgesteuerte Schnellschlussventile wurden eingehend untersucht und bewertet, um die optimale Versuchskonfiguration für bestmögliche Reproduzierbarkeit festzulegen. Es fand eine systematische Untersuchung der schlagartigen Kompression der Systeme Luft/Luft, TFE/Luft, TFE/TFE und TFE/N2 statt. In der Hochdrucksektion wurden Drücke bis 30 bar realisiert und im Niederdrucksektor konnten Anfangsdrücke im Bereich weniger Millibar bis hin zu Atmosphärendruck eingestellt werden. Als Hauptergebnis wurde ein „Hazard diagram" erstellt, mit dessen Hilfe die Zündwahrscheinlichkeit in Abhängigkeit vom Hochdruck und Niederdruck abgeschätzt werden kann. Gefährliche Bedingungen in Rohrleitungen können dadurch auf einfachem Weg identifiziert werden. Als Referenzsystem zur Beurteilung der maximal erreichbaren nicht reaktiven Kompressionstemperaturen wurde Luft/Luft verwendet. Die damit ermittelten Daten dienten zur Bewertung von zusätzlichen exothermen Effekten, wie sie etwa bei Vorreaktion des TFE im Falle einer Dimerisierung auftreten können. Entgegen der ursprünglichen Annahme konnten die Systeme TFE/Stickstoff und TFE/TFE im verwendeten Aufbau nicht durch Kompressionsvorgänge gezündet werden. T2 - 12. Fachtagung Anlagen-, Arbeits- und Umweltsicherheit CY - Köthen, Germany DA - 05.11.2015 KW - Tetrafluoroethen KW - Zerfall KW - Selbstentzündung KW - Adiabate Kompression PY - 2015 SN - 978-3-86011-091-1 SP - 1 EP - 10 AN - OPUS4-34852 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Uhlmann, E. A1 - Rethmeier, Michael A1 - Graf, B. A1 - Kersting, R. A1 - Bergmann, A. T1 - Flexible manufacturing with an additive process chain design, production and surface finish N2 - The industrial demand for flexible and innovative manufacturing technologies is continuously increasing. These technologies have to be sustainable and resource-efficient, and have to allow the production of long-life capital goods. Consequently, the additive processes gain in importance as they offer an enormous potential of application, especially for the turbomachinery industry. In order to use additive manufacturing technologies in industrial applications, it is necessary to consider the complete process chain, including all necessary pre- and postprocessing. Although additive manufacturing is increasingly covered in scientific research, the linking between this technology and conventional industrial processes is rarely described. T2 - ASPE Spring topical meeting - Achieving precision tolerances in additive manufacturing CY - Raleigh, NC, USA DA - 26.04.2015 PY - 2015 SN - 978-1-887706-67-4 SP - Session I, 5 EP - 9 AN - OPUS4-34855 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Woydt, Mathias A1 - Mohrbacher, H. ED - Singh, D. ED - Salem, J. ED - Wang, J. ED - Kirihara, S. T1 - Hardmetals based on niobium carbide (NbC) versus casted NbC bearing MMCs N2 - Thc tribological behavior under dry sliding of a Fe3Al-NbC composite prepared by pyrometallurgical synthesis is compared to NbC-based hard metals bonded by cobalt or Fe3Al. The dry sliding wear resistance (0,1-7/10 m/s) of the present Fe3Al-NbC with 60% NbC was close to those known of NbC-based hard metals. No grain pull-outs or fragmentations of the NbC grains were seen in the wear tracks, as a metallurgical interphase was formed between matrix and NbC grains. T2 - 39th International conference on advanced ceramics and composites CY - Daytona Beach, FL, USA DA - 25.01.2015 PY - 2015 SN - 978-1-119-21128-0 SP - 87 EP - 92 PB - Wiley AN - OPUS4-34888 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Dhotel, A. A1 - Chen, Z. A1 - Sun, J. A1 - Youssef, B. A1 - Saiter, J.-M. A1 - Schönhals, Andreas A1 - Tan, L. A1 - Delbreilh, L. T1 - From monomers to self-assembled monolayers: the evolution of molecular mobility with structural confinements N2 - The effect of structural constriction on molecular mobility is investigated by broadband dielectric spectroscopy (BDS) within three types of molecular arrangements: monomers, oligomers and self-assembled monolayers (SAMs). While disordered monomers exhibit a variety of cooperative and local relaxation processes, the constrained nanodomains of oligomers and highly ordered structure of monolayers exhibit much hindered local molecular fluctuations. Particularly, in SAMs, motions of the silane headgroups are totally prevented whereas the polar endgroups forming the monolayer canopy show only one cooperative relaxation process. This latter molecular fluctuation is, for the first time, observed independently from other overlapping dielectric signals. Numerous electrostatic interactions among those dipolar endgroups are responsible for the strong cooperativity and heterogeneity of the canopy relaxation process. Our data analyses also revealed that the bulkiness of dipolar endgroups can disrupt the organization of the monolayer canopy thus increasing their ability to fluctuate as temperature is increased. PY - 2015 DO - https://doi.org/10.1039/c4sm01893a SN - 1744-683X VL - 11 IS - 4 SP - 719 EP - 731 PB - RSC Publ. CY - Cambridge AN - OPUS4-32378 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Braun, Ulrike A1 - Eisentraut, Paul A1 - Fuchs, S. A1 - Deglmann, P. T1 - Sulphurous additives for polystyrene: Influencing decomposition behavior in the condensed phase N2 - The thermal decomposition behaviour of polystyrene (PS) containing sulphur and phosphorus additives was investigated, using thermogravimetry coupled with Fourier transform infrared spectroscopy (TGA-FTIR). It was found that the additives influence the decomposition process of the polymer in the condensed phase, resulting in a decrease in styrene monomer formation and an increase in styrene oligmer derivatives. Via reference measurements with binary mixtures it was found that the presence of sulphur additives influences the radicalic decomposition process of PS. In combination with quantum chemical calculations it was concluded that this is due to the formation of radicals that abstract hydrogen from the polymer matrix at lower temperatures, disfavouring the radicalic decomposition pathway leading to styrene. KW - Degradation KW - Theory and modeling KW - Thermogravimetric analysis KW - Polystyrene PY - 2015 DO - https://doi.org/10.1002/APP.41665 SN - 0021-8995 SN - 1097-4628 VL - 132 IS - 12 SP - 41665, 1 EP - 13 PB - Wiley InterScience CY - Hoboken, NJ AN - OPUS4-32380 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Schymura, M. A1 - Stegemann, Robert A1 - Fischer, A. T1 - Crack propagation behavior of solution annealed austenitic high interstitial steels N2 - Austenitic stainless steels provide a beneficial combination of chemical and mechanical properties and have been used in a wide field of applications for over 100 years. Further improvement of the chemical and mechanical properties was achieved by alloying nitrogen. But the solubility of N within the melt is limited and can be increased in substituting Ni by Mn and melting under increased pressure. In order to avoid melting under pressure and decrease production costs, a part of N can also be substituted by C. This leads to austenitic high interstitial steels (AHIS). Within the solution annealed state strength and ductility of AHIS is comparable or even higher of those of AHNS and can be further improved by cold working. Unfortunately the endurance limit does not follow this trend as it is known from cold-worked austenitic CrNi steels. This is due to the differences of the slip behavior which is governed by the stacking fault energy as well as other near field effects. Construction components operating under cyclic loads over long periods of time cannot be considered being free of voids or even cracks. Thus the crack propagation behavior is of strong interest as well. This contribution presents the tensile, fatigue, crack propagation and fracture toughness properties of AHNS and AHIS in comparison to those of CrNi-steels. The differences are discussed in relation to microstructural characteristic as well as their alterations under cyclic loading. KW - Austenitic high interstitial steel KW - Fatigue KW - Stable crack propagation KW - Planar slip PY - 2015 DO - https://doi.org/10.1016/j.ijfatigue.2015.04.014 SN - 0142-1123 VL - 79 SP - 25 EP - 35 PB - Elsevier Ltd. CY - Oxford AN - OPUS4-32436 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Pelegrina, J.L. A1 - Yawny, A. A1 - Olbricht, Jürgen T1 - Comment on: "Isothermal nature of the B2-B19' martensitic transformation in a Ti-51.2 Ni (at.%) alloy" N2 - Fukuda et al. published a paper (Scripta Mater. 68 (2013) 984–987) in which they claimed to be able to determine the isothermal nature of the martensitic transformation in a Ti–Ni alloy. They analyzed the evolution of electrical resistance during isothermal holding stages and concluded that the variations were a consequence of the isothermal transition between austenite and martensite. In the following we will demonstrate that the discussed data do not allow the interpretation presented and that the isothermal nature is not proved. KW - Thermal activation KW - Titanium–nickel alloy KW - Shape memory alloy KW - Nucleation PY - 2015 DO - https://doi.org/10.1016/j.scriptamat.2014.10.009 SN - 1359-6462 SN - 1872-8456 VL - 98 SP - 68 EP - 70 PB - Elsevier Ltd. CY - Oxford AN - OPUS4-32401 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Gluth, Gregor A1 - Rickard, W. ED - Leonelli, C. ED - Romagnoli, M. T1 - Design and characterization of fly ash-based geopolymer concretes for a round-robin durability testing program N2 - Fly ash-based, ambient-cured geopolymer concretes for a round-robin durability testing program were designed and characterized. Optimum activator composition was determined based on the Chemical composition of the amorphous part of the fly ash. Fly ash content, water content, and grading curves of the aggregates were varied for the concretes. Characterization of the concretes involved flow diameter, air void content, density, compressive strength, and permeability. The workability of the concretes was notably sensitive to changes in the mix-design. The majority of strength development in the concretes occurred within the first 28 days of curing; concrete strengths reached up to 86 MPa after 56 days. Two concretes, both with sufficient workability, but significantly different grading curve, water content, strength and permeability were identified to be suitable for the round-robin testing program. T2 - Geopolymers 2015 - The route to eliminate waste and emissions in ceramic and cement manufacturing - Engineering conference international (ECI) CY - Hernstein, Austria DA - 24.05.2015 KW - Fly ash geopolymer concrete KW - Concrete properties KW - Permeability PY - 2015 SN - 978-1-326-37732-8 SP - 67 EP - 70 AN - OPUS4-33106 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Shirakawa, M.A. A1 - Zilles, R. A1 - Mocelin, A. A1 - Gaylarde, C.C. A1 - Gorbushina, Anna A1 - Heidrich, Gabriele A1 - Giudice, M.C. A1 - Del Negro, G.M.B. A1 - John, V.M. T1 - Microbial colonization affects the efficiency of photovoltaic panels in a tropical environment N2 - Sub-aerial biofilm (SAB) development on solar panels was studied in São Paulo. After 6, 12 and 18 months' exposure, photovoltaic panels were covered by increasing proportions of organic matter (42%, 53% and 58%, respectively). Fungi were an important component of these biofilms; very few phototrophs were found. Major microorganisms detected were melanised meristematic ascomycetes and pigmented bacterial genera Arthrobacter and Tetracoccus. While diverse algae, cyanobacteria and bacteria were identified in biofilms at 6 and 12 months, diversity at a later stage was reduced to that typical for SAB: the only fungal group detected in 18 month biofilm was the meristematic Dothideomycetes and the only phototrophs Ulothrix and Chlorella. Photovoltaic modules showed significant power reductions after 6, 12 (both 7%) and 18 (11%) months. The lack of difference in power reduction between 6 and 12 months reflects the dual nature of soiling, which can result from the deposition of particulates as well as from SAB fouling. Although 12-month old SAB demonstrated an almost 10-fold increase in fungal colonization and a higher organic content, the larger non-microbial particles (above 10 µm), which were important for efficiency reduction of lightly-biofilmed panels, were removed by high rainfall just before the 12-month sampling. KW - Sub-aerial biofilms KW - Energy production KW - Phototrophs KW - Fungi KW - Solar panels KW - Fouling KW - Biofilms KW - Photovoltaic module PY - 2015 DO - https://doi.org/10.1016/j.jenvman.2015.03.050 SN - 0301-4797 SN - 1095-8630 VL - 157 SP - 160 EP - 167 PB - Elsevier Ltd. CY - Amsterdam AN - OPUS4-33107 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Schlick-Hasper, Eva A1 - Bethke, John A1 - Jahnke, Wolfgang A1 - Drousch, Björn A1 - Goedecke, Thomas A1 - Kraume, M. T1 - Maximum gauge pressure in dangerous goods packagings under normal conditions of carriage - comparison of direct measurement and calculation N2 - The objective of this work was to determine the maximum gauge pressure in the vapour phase above the liquid in different design types of dangerous goods packagings under normal conditions of carriage. The design types investigated were steel and plastic packagings with a volume of approximately 6 l. Two different methods were applied. In method 1, the pressure inside the packaging filled with a certain filling substance (dichloromethane) was directly measured under simulated conditions of carriage (degree of filling: 90%; filling temperature: 15°C; temperature during storage: 31°C). The maximum measured gauge pressures were between 89 mbar for a light plastic jerrican and 336 mbar for a steel drum. In method 2, the gauge pressure was calculated. The consideration of a rigid packaging combined with the assumption of a vapour pressure of zero during filling and sealing can serve as a worst case scenario. The calculated gauge pressure is approximately 1061 mbar. This procedure leads to the highest safety factor and does not require any experimental investigations. For a more realistic approximation of the gauge pressure of a non-rigid packaging, a packaging-specific function of relative expansion can be used, which is determined by a hydraulic pressure test. The calculated values ranged from 105 to 347 mbar. Method 2 provides conservative results. No hazardous filling substance is needed, and it allows a prediction of gauge pressure for other temperatures, substances and filling degrees. Therefore, this method could serve as alternative to UN Model Regulations 6.1.5.5.4 (a). KW - Dangerous goods packagings KW - Gauge pressure KW - Overpressure KW - Relative expansion KW - Data loggers KW - Normal conditions of carriage KW - Gefahrgutverpackungen KW - Überdruck KW - Relative Ausdehnung KW - Datenlogger KW - Normale Beförderungsbedingungen PY - 2015 DO - https://doi.org/10.1002/pts.2111 SN - 0894-3214 VL - 28 IS - 5 SP - 437 EP - 460 PB - Wiley & Sons, Ltd. CY - Chichester, UK AN - OPUS4-33108 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Thater, Raphael A1 - Wiethop, P. A1 - Rethmeier, Michael T1 - Welding simulation in car body construction N2 - Laser remote welding is a dynamic and flexible joining technology which enables various new approaches in welding sequence and weld position planning. However, the challenge is to find the optimal set-up within this large parameter space. In this article, numerical welding simulation is used to deal with this challenge. For a car door, different welding sequences and weld positions were numerically analyzed and compared with respect to its welding distortion behavior. PY - 2015 DO - https://doi.org/10.1002/latj.201500009 SN - 1613-7728 SN - 1863-9119 VL - 12 IS - 2 SP - 33 EP - 37 PB - Wiley-VCH CY - Weinheim AN - OPUS4-33110 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Richter, U. A1 - Mischke, R. A1 - Röllig, Mathias A1 - Maierhofer, Christiane A1 - Eigenfeld, K. A1 - Arendholz, S. T1 - Porosity detection in high pressure die castings - Part 1 - Microscopic investigations of pores in HPD castings N2 - Ever larger high pressure die castings (HPDC) with ever thinner walls raise the issue of castings defects. Properties of components are often strongly influenced by inner porosity. In the case of high pressure die castings, shrinkage and gas porosity occur. Two possibilities of characterizing porosity – by microscopy and active thermography – are dealt with in two articles. In this article, the microscopic investigations are presented. In a second article, first the feasibility of thermographic detection will be discussed based on simulations and, thereafter, the experimental determination of porosity with active thermography will be described. KW - Die casting KW - Aluminium KW - Pores KW - Microscopy KW - Active thermography KW - NDT PY - 2015 SN - 0046-5933 IS - 1 SP - Beitrag 03, 1 EP - 10 PB - Gießerei-Verl. CY - Düsseldorf AN - OPUS4-33111 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Mohamed, Zeinab A1 - Friedrich, Jörg Florian A1 - Krüger, Simone A1 - Farouk, M. A1 - Moustapha, M.E. T1 - Plasma deposition of adhesion-promoting polymer layers onto polypropylene for subsequent covering with thick fire retardant coatings N2 - Melamine resins were used as 50-µm-thick fire retardant coatings for polypropylene (PP). Preceding deposition, low-pressure plasma polymer films of allyl alcohol were coated onto PP to improve the adhesion between PP and melamine resin coatings. The efficiency of such fire retardant coatings was confirmed by flame tests. The plasma-deposited polymer and the dip-coated melamine resin films were characterized by Fourier transform infrared-attenuated total reflectance spectroscopy and X-ray photoelectron spectroscopy (XPS). The adhesion of coatings was measured using a 90° peel test with a doubled-faced adhesive tape. To detect the locus of failure, the peeled layer surfaces were inspected using optical microscopy and XPS. Thermal properties of PP thick melamine resin-coated films were analyzed by thermogravimetric analysis. KW - Polymer KW - Plasma KW - Polypropylene KW - Fire retardant KW - Melamine precursors KW - Plasma polymerization KW - Allyl alcohol KW - Flame retardants KW - Curing PY - 2015 DO - https://doi.org/10.1080/01694243.2015.1033878 SN - 0169-4243 SN - 1568-5616 VL - 29 IS - 14 SP - 1522 EP - 1533 PB - VNU Science Press CY - Utrecht AN - OPUS4-33112 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Krug, Sonja A1 - Hohendorf, Stefan A1 - Redmer, Bernhard T1 - Radiographien in der Kunstbibliothek N2 - Im Rahmen des Basisprojektes »Sammlungserschließung« wurden im Oktober 2014 Radiographien von 14 Gemälden und zwei Schmuckrahmen aus der Sammlung Modebild – Lipperheidesche Kostümbibliothek (Kunstbibliothek, Staatliche Museen zu Berlin) erzeugt. Die Aufnahmen wurden von Anja Schönstedt, Bernhard Redmer und Stefan Hohendorf von der Bundesanstalt für Materialforschung und -prüfung (BAM, Fachbereich 8.3 Radiologische Verfahren) angefertigt und uns zur weiteren Bearbeitung bereitgestellt. PY - 2015 VL - 100 SP - 5 EP - 7 AN - OPUS4-33113 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Hoffmeister, H. A1 - Böllinghaus, Thomas T1 - Modeling the effects of dissolved hydrogen, temperature, pH, and global stress on stress corrosion cracking of a Cr-Ni model alloy in high-temperature water N2 - As an extension of recently presented stress corrosion cracking (SCC) models for pure nickel and iron in high-temperature water, the anodic path, hydrogen-assisted stress corrosion cracking of a model Cr-Ni alloy is presented, utilizing Alloy 600 (UNS 06600) mechanical properties. With the local anodic path corrosion as the crack initiation phase, the respective oxides precipitate while the crack tip solution acidify and establish local hydrogen ion reduction conditions. Depending on the applied global stress, local plastic straining then provides an active crack tip surface that transfers atomic hydrogen to the plastic zone ahead of the crack tip. Hydrogen-assisted crack propagation is then controlled by the calculated local hydrogen ion reduction charge and the plastic strain distribution ahead of the crack tip. The results show that for global stress levels close to the yield stress and at constant dissolved oxygen contents, the increasing dissolved hydrogen contents provide peak crack growth rates at hydrogen levels that decrease both with increasing temperatures and bulk pH. The peak crack growth rates also decrease with decreasing global stress as well as with increasing temperature and increasing bulk pH. The results are in accordance with published experimental investigations and operational experiences regarding the effects of dissolved hydrogen on stress corrosion rates in high-temperature waters of nuclear reactors. They are explained by the interaction between the electrochemical parameters of the respective reactions. KW - Chromium-nickel alloy KW - Dissolved hydrogen KW - High-temperature water KW - Stress corrosion cracking PY - 2015 DO - https://doi.org/10.5006/1443 SN - 0010-9312 SN - 1938-159X VL - 71 IS - 5 SP - 559 EP - 573 PB - National Association of Corrosion Engineers CY - Houston, Texas, USA AN - OPUS4-33114 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Völzke, Holger A1 - Liu, Y. T1 - Collaboration on aging management for extended storage of used fuel N2 - A Memorandum of Understanding (MOU) between the Federal Institute for Materials Research and Testing (BAM) and Argonne National Laboratory (Argonne) was signed in the fall of 2014. Its objectives are to promote cooperation among scientists and specialists at BAM and Argonne and establish a framework for collaboration in the field of advanced technologies associated with the back end of the nuclear fuel cycle. Collaborative activities involving the BAM and Argonne may be implemented through the promotion of joint research activities and scientific workshops and conferences; the exchange of technical information; and visits by scientists, specialists, and graduate, postgraduate, and Ph.D. students. The first Argonne/BAM workshop was held at Argonne in October 2014 to discuss aging management issues related to the long-term dry storage of spent fuel. Major topics for potential collaboration on the extended storage of spent nuclear fuel and its subsequent transportation were identified. T2 - IHLRWM 2015 - 15th International high-level radioactive waste management conference CY - Charleston, SC, USA DA - 12.04.2015 KW - Aging management KW - Fuel KW - Extended storage KW - Nuclear PY - 2015 SN - 978-0-89448-719-4 SP - 814 EP - 817 AN - OPUS4-33115 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Chang, Y.-J. A1 - Sproesser, G. A1 - Neugebauer, S. A1 - Wolf, K. A1 - Scheumann, R. A1 - Pittner, Andreas A1 - Rethmeier, Michael A1 - Finkbeiner, M. T1 - Environmental and social life cycle assessment of welding technologies N2 - Life Cycle Assessment (LCA) and Social Life Cycle Assessment (SLCA) are applied in evaluating possible social and environmental impacts of the state-of-art welding technologies, such as Manual Metal Arc Welding (MMAW), Manual Gas Metal Arc Welding (GMAW), Automatic GMAW and Automatic Laser-Arc Hybrid Welding (LAHW). The LCA results indicate that for 1 meter weld seam, MMAW consumes the largest amount of resources (like filler material and coating on electrodes) and energy, which contributes to comparatively higher environmental impacts in global warming potential, acidification, photochemical ozone creation potential and eutrophication than other chosen processes. With regard to social aspects, the health issues and fair salary are under survey to compare the relative potential risk on human health caused by fumes in different welding technologies, and to indicate the sufficiency of current salary of welders in Germany. The results reflect that the wage status of welders is still fair and sufficient. The manual processes bring much higher potential risk of welders’ health than the automatic processes, especially MMAW. KW - Fair salary KW - Human health KW - Life Cycle Assessment (LCA) KW - Social Life Cycle Assessment (SLCA) KW - Welding PY - 2015 DO - https://doi.org/10.1016/j.procir.2014.07.084 SN - 2212-8271 VL - 26 SP - 293 EP - 298 PB - Elsevier CY - Amsterdam [u.a.] AN - OPUS4-33036 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Bachmann, Marcel A1 - Avilov, Vjaceslav A1 - Gumenyuk, Andrey A1 - Rethmeier, Michael T1 - Magnets improve quality of high-power laser beam welding N2 - Welding is one of the most critical operations for the construction of reliable metal structures in everything from ships to reactor vessels. When welds fail, the entire structure often fails—so expectations on weld quality have never been higher. Any process that uses a localized heat source, such as welding, is likely to result in some distortion. The welding process of very thick metal components is not inherently stable and is barely controllable without external forces. KW - Laser beam welding KW - Hartmann effect KW - Electromagnetic weld control KW - Finite element simulation PY - 2015 UR - http://digital.industrial-lasers.com/industriallasers/20150304#pg1 SN - 1523-4266 SN - 0888-935X VL - 30/2 IS - March/April SP - 10 EP - 12 PB - Pennwell CY - Tulsa, Okla., USA AN - OPUS4-33037 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Przondziono, R. A1 - Timothy, J.J. A1 - Nguyen, M. A1 - Weise, Frank A1 - Breitenbücher, R. A1 - Meschke, G. A1 - Meng, Birgit T1 - Vorschädigungen in Beton infolge zyklischer Beanspruchungen und deren Auswirkung auf Transportprozesse im Hinblick auf eine schädigende AKR N2 - Auf Grundlage der Zielsetzung der Forschergruppe 1498 beschäftigt sich dieser Beitrag mit den Auswirkungen einer zyklischen mechanischen Belastung im Vierpunktbiegeversuch auf das Transportverhalten in Betongefüge. Hierzu wurde zunächst die Degradation des Mikrogefüges mittels Ultraschallmessungen sowie rissmikroskopischen Untersuchungen an Dünnschliffen charakterisiert. Mit dem Ziel der numerischen Modellbildung wurden Untersuchungen zum Wassereindringverhalten durchgeführt. Es wurden u. a. das Wassereindringverhalten über die Zeit und der Einfluss von Vorschädigungen experimentell geprüft. Basierend auf den gewonnenen Erkenntnissen zu den Einzelprozessen des Ionentransports in poröses Gefüge wurde ein mikromechanisches Mehrskalenmodell entwickelt, welches es ermöglicht, die Wirkung der Vorschädigung auf gekoppelte Feuchte- und Ionentransportprozesse vorherzusagen. Das Modell berücksichtigt die Topologie und räumliche Verteilung der Mikrorisse und deren Einfluss auf die Ionendiffusivität. Die numerische Simulation liefert bei anisotroper Verteilung der Mikrorisse eine erhöhte Alkali-Eindringtiefe. ---------------------------------------------------------------------------------------------------------------------------------- According to the goals of the research group 1498, this paper deals with the effects of cyclic flexural loading in a four-point bending test on the fluid transport processes within a concrete structure. Therefore, the degradation of the microstructure is characterized through ultrasonic wave measurements as well as microscopic crack analysis. In order to numerically model these processes, experiments on the penetration behavior of water into the concrete were carried out. The penetration behavior over time as well as the influence of degradation on the water transport were investigated. To predict the influence of concrete degradation on alkali diffusivity, a multi-scale continuum micromechanics model is incorporated into the numerical model, which accounts for the topology and the three-dimensional distribution of microcracks. As expected, the numerical simulation predicts larger alkali-penetration in pre-damaged concrete. Regarding the micro-crack distribution, an anisotropic distribution of micro-cracks tangential to the direction of the alkali and water flux increases their penetration depth. KW - Alkali-Kieselsäure-Reaktion KW - Baustoffe KW - Degradation KW - Ionentransport KW - Mikromechanik KW - Modellierung KW - Straßenbeton KW - Transportprozesse KW - Vorschädigung KW - zyklische Belastung KW - Korrosion KW - Versuche KW - Fahrbahn KW - Cyclic loading KW - Transport process KW - Schädigende AKR KW - ASR damage PY - 2015 DO - https://doi.org/10.1002/best.201400095 SN - 0005-9900 SN - 1437-1006 VL - 110 IS - 1 SP - 3 EP - 12 PB - Ernst CY - Berlin AN - OPUS4-33039 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Recknagel, Christoph A1 - Geburtig, Anja A1 - Wachtendorf, Volker T1 - Die Kunst der Fuge im Glasfassadenbau N2 - Ingenieurbauwerke wie Brücken, hoch beanspruchte Verkehrsflächen oder auch Hochhäuser und deren Bauwerksteile wie z.B. Hochhausfassaden werden aus technischen und ästhetischen Gründen durch Fugen in Einzelabschnitte unterteilt. Zur Sicherstellung der Gebrauchsfähigkeit und zum Schutz des Gesamtbauwerks, aber in zunehmendem Maße auch zur statisch-konstruktiven Anbindung der Bauwerksteile, werden diese Fugenspalte in aller Regel durch spezielle Fugenfüllsysteme verschlossen. Aufgrund der hohen Sicherheitsrelevanz bei Fugenfüllungen im Glasfassadenbau fordert das Baurecht auch bei diesen Bauprodukten als Voraussetzung für die baupraktische Verwendbarkeit neben dem Nachweis der Funktionsfähigkeit auch den Nachweis der Dauerhaftigkeit. Da die hierfür bekannten Nachweismethoden zur Dauerhaftigkeit keine allgemeine Zulassungsakzeptanz finden, kann das ästhetische, bauphysikalische und ökonomische Potential von modernen geklebten Ganzglasfassaden (sogenannte SSG-Fassaden) in der Baupraxis der Bundesrepublik Deutschland derzeit nicht ausgenutzt werden. Grund dafür sind die ungenügend erfassten und in den Bewertungsverfahren simulierten Wechselwirkungen derartiger Baukonstruktionen mit der Umwelt. In diesem Beitrag soll am Beispiel moderner Fugen im Glasfassadenbau (SSG-Fassaden) eine ganzheitliche gebrauchsbezogene Versuchsmethodik zur kontrollierten Ansprache der Funktionsfähigkeit und Dauerhaftigkeit von Fugensystemen unter realitätsnah und reproduzierbar simulierten Umwelteinwirkungen vorgestellt werden. Dazu werden die maßgebenden Umwelteinflüsse und die Quantifizierung der daraus folgenden Beanspruchungen auf derartige Fugensysteme dargestellt. Basierend darauf werden eine repräsentative Beanspruchungsfunktion zur Nachstellung der maßgebenden Umwelteinflüsse und Beanspruchungen auf das System Tragrahmen - Fugenfüllung- Glasscheibe sowie eine geeignete Probendimensionierung abgeleitet. In der Konsequenz werden die Erkenntnisse in den Aufbau einer neuartigen komplexen Versuchseinrichtung überführt. Funktionsprinzip und Leistungsparameter dieser Anlage zur Umweltsimulation werden vorgestellt. Die Möglichkeiten der Systemkennzeichnung werden vorgestellt. Erste Versuchsergebnisse zeigen das Potential der neuartigen Bewertungsmethodik auf, die Kunst der Fuge im Bauwesen gebrauchsorientiert weiter zu entwickeln. T2 - 44. Jahrestagung der GUS 2015 CY - Stutensee-Blankenloch, Germany DA - 25.03.2015 KW - Umweltsimulation KW - Dauerhaftigkeit KW - Funktionsverhalten KW - Neue Untersuchungsmethodik PY - 2015 SN - 978-3-9816286-4-7 SP - 125 EP - 139 AN - OPUS4-33040 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Heinrich, Thomas A1 - Traulsen, Christoph Hans-Henning A1 - Holzweber, Markus A1 - Richter, S. A1 - Kunz, V. A1 - Kastner, S.K. A1 - Krabbenborg, S.O. A1 - Huskens, J. A1 - Unger, Wolfgang A1 - Schalley, C.A. T1 - Coupled molecular switching processes in ordered mono- and multilayers of stimulus-responsive rotaxanes on gold surfaces N2 - Interfaces provide the structural basis for function as, for example, encountered in nature in the membrane-embedded photosystem or in technology in solar cells. Synthetic functional multilayers of molecules cooperating in a coupled manner can be fabricated on surfaces through layer-by-layer self-assembly. Ordered arrays of stimulus-responsive rotaxanes undergoing well-controlled axle shuttling are excellent candidates for coupled mechanical motion. Such stimulus-responsive surfaces may help integrate synthetic molecular machines in larger systems exhibiting even macroscopic effects or generating mechanical work from chemical energy through cooperative action. The present work demonstrates the successful deposition of ordered mono- and multilayers of chemically switchable rotaxanes on gold surfaces. Rotaxane mono- and multilayers are shown to reversibly switch in a coupled manner between two ordered states as revealed by linear dichroism effects in angle-resolved NEXAFS spectra. Such a concerted switching process is observed only when the surfaces are well packed, while less densely packed surfaces lacking lateral order do not exhibit such effects. KW - Molecular machine KW - Rotaxane KW - LBL growth KW - XPS KW - NEXAFS KW - SIMS PY - 2015 DO - https://doi.org/10.1021/ja512654d SN - 0002-7863 SN - 1520-5126 VL - 137 IS - 13 SP - 4382 EP - 4390 PB - American Chemical Society CY - Washington, DC, USA AN - OPUS4-33077 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Ebert-Spiegel, M. A1 - Goecke, S.-F. A1 - Rethmeier, Michael T1 - Possibilities for compensating a higher heat input, in particular by the torch offset relative to the top sheet at the fillet weld on a lap joint N2 - This paper deals with the use of an adaptive control system for compensating the variation in the gap height of a fillet welded lap joint. Gap bridging requires the input of additional filler material and is related to an increased energy input. Hence, the aim was a compensation of the effect of an increased heat input, in order to maintain the weld pool and excessive penetration, which can prevent consequently root reinforcement and burn-through. The findings achieved in this work show possibilities for a real-time controlled adjustments of the welding parameters in automated metal active gas (MAG) welding for compensating a higher heat input, in particular by means of the torch offset relative to the top sheet at the fillet weld on a lap joint. KW - MAG welding KW - Adaptive control KW - High strength steels KW - Gap KW - Energy input KW - Mathematical models PY - 2015 DO - https://doi.org/10.1007/s40194-015-0220-9 SN - 0043-2288 SN - 1878-6669 VL - 59 IS - 3 SP - 443 EP - 453 PB - Springer CY - Oxford AN - OPUS4-33079 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Tötzke, C. A1 - Manke, I. A1 - Gaiselmann, G. A1 - Bohner, J. A1 - Müller, Bernd R. A1 - Kupsch, Andreas A1 - Hentschel, Manfred P. A1 - Schmidt, V. A1 - Banhart, J. A1 - Lehnert, W. T1 - A dedicated compression device for high resolution X-ray tomography of compressed gas diffusion layers N2 - We present an experimental approach to study the three-dimensional microstructure of gas diffusion layer (GDL) materials under realistic compression conditions. A dedicated compression device was designed that allows for synchrotron-tomographic investigation of circular samples under well-defined compression conditions. The tomographic data provide the experimental basis for stochastic modeling of nonwoven GDL materials. A plain compression tool is used to study the fiber courses in the material at different compression stages. Transport relevant geometrical parameters, such as porosity, pore size, and tortuosity distributions, are exemplarily evaluated for a GDL sample in the uncompressed state and for a compression of 30 vol.%. To mimic the geometry of the flow-field, we employed a compression punch with an integrated channel-rib-profile. It turned out that the GDL material is homogeneously compressed under the ribs, however, much less compressed underneath the channel. GDL fibers extend far into the channel volume where they might interfere with the convective gas transport and the removal of liquid water from the cell. KW - PEM fuel cell KW - Gas diffusion layer (GDL) KW - Compression device KW - X-ray tomography KW - Synchrotron KW - Tortuosity PY - 2015 DO - https://doi.org/10.1063/1.4918291 SN - 0034-6748 SN - 1089-7623 VL - 86 IS - 4 SP - 043702-1 EP - 043702-6 PB - American Institute of Physics CY - Melville, NY, USA AN - OPUS4-33081 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Deresch, Andreas A1 - Bellon, Carsten A1 - Jaenisch, Gerd-Rüdiger A1 - Ewert, Uwe ED - Chimenti, D.E. ED - Bond, L.J. T1 - Fast model of electron transport for radiographic spectrum simulation N2 - Correctly modeling the continuous photon spectrum of X-ray tubes requires detailed knowledge of the probability distribution of electron properties at the time of X-ray photon creation, in particular electron energy, depth within the target, and direction of movement. Semi-analytical X-ray spectrum models frequently assume a very simplified or even uniform distribution of electron direction. In the case of thick targets and small deviations from normal incidence this is a useful approximation. For thin targets or large deviations from normal incidence the correct distribution of electron directions becomes more important. As calculation speed is an important aspect of semi-analytical models compared to Monte Carlo simulations, fast evaluation of the distribution of electron properties is highly desirable. The approach presented here numerically evaluates the evolution of a discrete probability distribution of electron properties due to single electron scatter interactions within a plane target. This allows capturing the important aspects of the electron distribution while achieving runtimes of a few seconds up to a minute on a standard office PC. T2 - 41st Annual review of progress in quantitative nondestructive evaluation CY - Boise, Idaho, USA DA - 20.07.2014 KW - Radiography KW - Spectrum KW - Modeling KW - Valildation PY - 2015 SN - 978-0-7354-1292-7 DO - https://doi.org/10.1063/1.4914656 N1 - Serientitel: AIP conference proceedings – Series title: AIP conference proceedings VL - 1650 SP - 579 EP - 585 PB - AIP Publishing AN - OPUS4-33082 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Jaenisch, Gerd-Rüdiger A1 - Deresch, Andreas A1 - Bellon, Carsten A1 - Schumm, A. A1 - Lucet-Sanchez, F. A1 - Guerin, P. ED - Chimenti, D.E. ED - Bond, L.J. T1 - Radiography benchmark 2014 N2 - The purpose of the 2014 WFNDEC RT benchmark study was to compare predictions of various models of radiographic techniques, in particular those that predict the contribution of scattered radiation. All calculations were carried out for homogenous materials and a mono-energetic X-ray point source in the energy range between 100 keV and 10 MeV. The calculations were to include the best physics approach available considering electron binding effects. Secondary effects like X-ray fluorescence and bremsstrahlung production were to be taken into account if possible. The problem to be considered had two parts. Part I examined the spectrum and the spatial distribution of radiation behind a single iron plate. Part II considered two equally sized plates, made of iron and aluminum respectively, only evaluating the spatial distribution. Here we present the results of above benchmark study, comparing them to MCNP as the assumed reference model. The possible origins of the observed deviations are discussed. T2 - 41st Annual review of progress in quantitative nondestructive evaluation CY - Boise, Idaho, USA DA - 20.07.2014 KW - Radiography KW - Spectrum KW - Modeling KW - Validation PY - 2015 SN - 978-0-7354-1292-7 DO - https://doi.org/10.1063/1.4914809 N1 - Serientitel: AIP conference proceedings – Series title: AIP conference proceedings VL - 1650 SP - 1834 EP - 1846 PB - AIP Publishing AN - OPUS4-33083 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Maierhofer, Christiane A1 - Krankenhagen, Rainer A1 - Myrach, Philipp A1 - Röllig, Mathias A1 - Mecke, R. A1 - Schiller, M. A1 - Seidl, T. A1 - Kalisch, U. A1 - Hennen, C. A1 - Meinhardt, J. A1 - Kersten, H. A1 - Groll, E.T. T1 - 3D-Kartierung von oberflächennahen Schäden an Bauwerken und Bauteilen N2 - Die messtechnische Erfassung von Bauwerkschäden ist eine wichtige Voraussetzung für die dreidimensionale und zeitaufgelöste Darstellung von möglicherweise sicherheitsrelevanten Veränderungen an Bauwerken, wie z. B. Verformungen, Verwindungen und Risswachstum. Ziel des vorgestellten Projektes war die Entwicklung eines Verfahrens zur effizienten und wiederholbaren 3D-Schadenkartierung an zum Teil empfindlichen Bauteiloberflächen. KW - 3D-Kartierung KW - Aktive Thermografie KW - Photogrammetrie KW - Trackingsystem KW - Risse PY - 2015 IS - März SP - 35 EP - 39 PB - Ernst & Sohn CY - Berlin AN - OPUS4-33084 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Hong, Shuxian A1 - Lai, W.-L. A1 - Helmerich, Rosemarie T1 - Experimental monitoring of chloride-induced reinforcement corrosion and chloride contamination in concrete with ground-penetrating radar N2 - In this article, we present a laboratory experiment to monitor the accelerated corrosion in concrete using ground-penetrating radar (GPR). Four concrete test specimens were cast with rebars of different size and placed at different depths. The lifetime decades of reinforcement corrosion process were accelerated into 18 days by using the impress current technique. The electrochemical corrosion process was periodically monitored with GPR. Two control specimens were also prepared to investigate the influence of chloride contamination on GPR signal. The measured data were analysed both in time and frequency domains. In time domain, the peak-to-peak amplitude of a wave reflected by a rebar was calculated to investigate the relationship between an increase in signal amplitude and the degree of corrosion. In frequency domain, the time–frequency representations of the signal were computed by using S-transform. The results show that reinforce corrosion increased the amplitude of reflected signal in time domain but did not change the peak frequency in frequency domain while chloride contamination attenuates the signal to smaller amplitude and lower peak frequency. Based on the results, a novel process is finally proposed for GPR-based corrosion detection. KW - Non-destructive KW - Reinforcement corrosion KW - GPR KW - Chloride KW - Moisture KW - S-transform PY - 2015 DO - https://doi.org/10.1080/15732479.2013.879321 SN - 1573-2479 VL - 11 IS - 1 SP - 15 EP - 26 PB - Taylor & Francis CY - London [u.a.] AN - OPUS4-33085 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Krietsch, Arne A1 - Scheid, Marc A1 - Schmidt, Martin A1 - Krause, U. T1 - Explosion behaviour of metallic nano powders N2 - This paper describes experiences and results of experiments with several metallic dusts within the nanometer range. The nano dusts (aluminium, iron, zinc, titanium and copper) were tested in a modified experimental setup for the test apparatus 20 L-sphere (also known as 20-L Siwek Chamber), that enables the test samples to be kept under inert atmospheric conditions nearly until ignition. This setup was already introduced in earlier papers by the authors. It was designed to allow the determination of safety characteristics of nano powders under most critical circumstances (e.g. minimisation of the influence of oxidation before the test itself). Furthermore the influence of passivation on explosion behaviour is investigated and additional tests with deposited dust were carried out to describe the burning behaviour of all dusts. For a better characterisation all samples were tested with a simultaneous thermal analysis (STA). To minimise the influence of oxidation all samples were handled at inert conditions until shortly before ignition or start of the test respectively. KW - Dust explosion KW - Nano powder KW - Ignition KW - Explosion protection PY - 2015 DO - https://doi.org/10.1016/j.jlp.2015.03.016 SN - 0950-4230 SN - 1873-3352 VL - 36 SP - 237 EP - 243 PB - Butterworth CY - Guildford, Surrey AN - OPUS4-33026 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Körner, Ursula T1 - Marktüberwachung an Druckgasflaschen zur Überprüfung der Wärmebehandlung N2 - Die ISO-Normen für Druckgasflaschen aus Aluminiumlegierungen erfordern in der Regel eine Wärmebehandlung nach dem Umformungsprozess. Eine solche Wärmebehandlung ist ein kostspieliger Teil bei der Herstellung. Wegen des zunehmenden internationalen Handelsaufkommens müssen Marktüberwachungsbehörden über einfache und zuverlässige Testverfahren zur Überprüfung der ordnungsgemäß durchgeführten Wärmebehandlung an Druckgasflaschen verfügen. In diesem Beitrag wird beispielhaft die unterschiedliche Leistungsfähigkeit der wärmebehandelten und der nicht-wärmebehandelten Gasflaschen gezeigt und verschiedene Verfahren auf ihre Eignung als einfach durchzuführende Stichprobenkontrolle untersucht. KW - Marktüberwachung KW - Gasflasche KW - Aluminium KW - Stichprobenprüfung KW - Wärmebehandlung KW - Berstversuch KW - Zugversuch KW - Härte KW - Ätzen PY - 2015 SN - 2191-0073 VL - 5 IS - 5 SP - 1 EP - 10 PB - Springer-VDI-Verl. CY - Düsseldorf AN - OPUS4-33027 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Winkelmann, Aimo A1 - Nolze, Gert T1 - Orientation mapping of non-centrosymmetric crystals T2 - RMS Electron backscatter diffraction meeting CY - Glasgow, UK DA - 30.03.2015 KW - EBSD KW - Cross-correlation KW - Non-centrosymmetry KW - Simulation PY - 2015 SP - 1 AN - OPUS4-33030 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Su, H. A1 - Wu, Chuan Song A1 - Bachmann, Marcel A1 - Rethmeier, Michael T1 - Numerical modeling for the effect of pin profiles on thermal and material flow characteristics in friction stir welding N2 - Understanding the influence of tool/pin shapes on the thermal and material flow behaviors in friction stir welding is of great significance for the optimal design of tool/pin based on a scientific principle. In this study, a numerical method based on computational fluid dynamics is employed to quantitatively analyze the thermo-physical phenomena in friction stir welding with two tools of different pin shapes (axisymmetrical conical tool and asymmetrical triflat tool). Through combining a steady state model with a transient state model, both the computation efficiency and accuracy are ensured. The boundary conditions of heat transfer and material flow are determined with considering a partial sticking/sliding contact condition at the tool–workpiece interface. The total heat generation, heat density and temperature distribution during the welding process with triflat tool are elucidated and compared with that of conical tool, and the material flow patterns and deformation regions of various pin orientations are illustrated in detail. It is found that the deformation zone caused by triflat tool is larger than that by conical tool, which is validated by the weld macrographs. The computed thermal cycles and peak temperature values at some locations are in good agreement with the experimentally measured ones. KW - Friction stir welding KW - Pin profile KW - Heat generation KW - Material flow KW - Modeling PY - 2015 DO - https://doi.org/10.1016/j.matdes.2015.04.012 SN - 0261-3069 SN - 0264-1275 VL - 77 SP - 114 EP - 125 PB - Elsevier Ltd. CY - Oxford AN - OPUS4-33031 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Auersch, Lutz T1 - Excitation of ground vibration due to the passage of trains over a track with trackbed irregularities and a varying support stiffness N2 - Train-induced ground vibration can be excited by wheel and track irregularities and by two kinds of irregularities of the soil, by geometric irregularities or by the spatially varying soil stiffness. For both types of irregularities, the effective track irregularity on top of the track is calculated in wavenumber domain and with wavenumber integrals. For a general multi-beam track model, the wavenumber integrals are solved numerically. The irregularities of the soil are filtered by the track when transferred from the bottom to the top of the track. The high-wavenumber irregularities are strongly reduced due to the bending stiffness of the track and the compliance of the support. In addition, soft track elements reduce directly the stiffness variation of the support. Therefore, the mitigation effect of elastic track elements for these excitation components seems to be important. For under-sleeper pads and slab tracks, calculation and measurements are presented including additional excitation components and the dynamic vehicle–track interaction, and the relevance of the excitation mechanisms is discussed based on the dynamic forces which are acting on the ground. Due to the restricted amplitudes, the parametric excitation by the stiffness variation seems to be less important than the geometric irregularities. The calculations yield the correct trends of the measurements and many details of the measured ballast, slab, and under-sleeper-pad tracks. KW - Varying track stiffness KW - Geometric trackbed irregularities KW - Multi-beam-on-support model KW - Elastic track elements KW - Parametric excitation PY - 2015 DO - https://doi.org/10.1080/00423114.2014.968173 SN - 0042-3114 VL - 53 IS - 1 SP - 1 EP - 29 PB - Taylor & Francis CY - Basingstoke, Hants. AN - OPUS4-33032 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Senoner, Mathias A1 - Maaßdorf, A. A1 - Rooch, Heidemarie A1 - Österle, Werner A1 - Malcher, M. A1 - Schmidt, M. A1 - Kollmer, F. A1 - Paul, D. A1 - Hodoroaba, Vasile-Dan A1 - Rades, Steffi A1 - Unger, Wolfgang T1 - Lateral resolution of nanoscaled images delivered by surface-analytical instruments: application of the BAM-L200 certified reference material and related ISO standards N2 - The certified reference material BAM-L200, a nanoscale stripe pattern for length calibration and specification of lateral resolution, is described. BAM-L200 is prepared from a cross-sectioned epitaxially grown layer stack of AlxGa1–xAs and InxGa1–xAs on a GaAs substrate. The surface of BAM-L200 provides a flat pattern with stripe widths ranging down to 1 nm. Calibration distances, grating periods and stripe widths have been certified by TEM with traceability to the length unit. The combination of gratings, isolated narrow stripes and sharp edges of wide stripes offers plenty of options for the determination of lateral resolution, sharpness and calibration of length scale at selected settings of imaging surface-analytical instruments. The feasibility of the reference material for an analysis of the lateral resolution is demonstrated in detail by evaluation of ToF-SIMS, AES and EDX images. Other applications developed in the community are summarized, too. BAM-L200 fully supports the implementation of the revised International Standard ISO 18516 (in preparation) which is based on knowledge outlined in the Technical Report ISO/TR 19319:2013. KW - AES KW - BAM-L200 KW - CRM KW - EDX KW - Imaging KW - Lateral resolution KW - Sharpness KW - Standardisation KW - STXM KW - ToF-SIMS KW - XPEEM KW - XPS KW - Certified reference material KW - Imaging surface analysis PY - 2015 DO - https://doi.org/10.1007/s00216-014-8135-7 SN - 1618-2642 SN - 1618-2650 VL - 407 IS - 11 SP - 3211 EP - 3217 PB - Springer CY - Berlin AN - OPUS4-33033 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Österle, Werner A1 - Dmitriev, A.I. A1 - Gradt, Thomas A1 - Häusler, Ines A1 - Hammouri, Basem A1 - Morales Guzman, Pablo Israel A1 - Wetzel, B. A1 - Yigit, D. A1 - Zhang, G. T1 - Exploring the beneficial role of tribofilms formed from an epoxy-based hybrid nanocomposite N2 - The composition and nanostructure of a beneficial tribofilm formed during sliding of a hybrid nanocomposite against steel were characterized comprehensively. A similar nanostructure was produced by high energy ball milling of the three identified tribofilm constituents: silica, hematite and graphite. By supplying powders to a pin-on-disc test it has been shown that neither silica, nor hematite, nor a mixture of both provide the low coefficient of friction (COF) observed for the hybrid composite. Only if graphite was blended with the oxides, the low COF was obtained. Thus, a film of finely dispersed stable inorganic wear products containing 15 vol% graphite provides low friction and wear in the considered case. KW - TEM KW - Nanocomposite KW - Tribofilm KW - Ball milling KW - Pin-on-disc test PY - 2015 DO - https://doi.org/10.1016/j.triboint.2015.03.006 SN - 0301-679X VL - 88 SP - 126 EP - 134 PB - Butterworth-Heinemann CY - Oxford AN - OPUS4-33035 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kromm, Arne A1 - Van der Mee, V. A1 - Kannengießer, Thomas A1 - Kalfsbeek, B. T1 - Properties and weldability of modified low transformation termperature filler wires N2 - Low transformation temperature (LTT) alloys allow to control residual stresses already during the welding process. Especially high-strength structural steel applications may benefit from the LTT effect as they are sensitive to residual stresses due to a limited ductility. Within this study, two modified LTT alloys were tested concerning their weldability under varying conditions. Beside the transformation behavior, basic material properties were determined from all weld metal. Hot cracking as well as cold cracking susceptibility was evaluated using specific tests. The materials' capability for residual stress control was characterized by online measurements of the occurring loads during double-sided multipass fillet welding in a special test facility. Varying heat control parameters were found to affect the stress buildup significantly. In the specific case, the results revealed that higher working temperatures may favor lower stress buildup despite the higher overall heat input. Local residual stress measurements using X-ray diffraction support this finding. KW - Weldability KW - Filler materials KW - Wire KW - Temperature KW - Transformation PY - 2015 DO - https://doi.org/10.1007/s40194-014-0215-y SN - 0043-2288 SN - 1878-6669 VL - 59 IS - 3 SP - 413 EP - 425 PB - Springer CY - Oxford AN - OPUS4-33066 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Drzymala, Sarah A1 - Weiz, S. A1 - Heinze, J. A1 - Marten, S. A1 - Prinz, Carsten A1 - Zimathies, Annett A1 - Garbe, L.-A. A1 - Koch, Matthias T1 - Automated solid-phase extraction coupled online with HPLC-FLD for the quantification of zearalenone in edible oil N2 - Established maximum levels for the mycotoxin zearalenone (ZEN) in edible oil require monitoring by reliable analytical methods. Therefore, an automated SPE-HPLC online system based on dynamic covalent hydrazine chemistry has been developed. The SPE step comprises a reversible hydrazone formation by ZEN and a hydrazine moiety covalently attached to a solid phase. Seven hydrazine materials with different properties regarding the resin backbone, pore size, particle size, specific surface area, and loading have been evaluated. As a result, a hydrazine-functionalized silica gel was chosen. The final automated online method was validated and applied to the analysis of three maize germ oil samples including a provisionally certified reference material. Important performance criteria for the recovery (70–120 %) and precision (RSDr <25 %) as set by the Commission Regulation EC 401/2006 were fulfilled: The mean recovery was 78 % and RSDr did not exceed 8 %. The results of the SPE-HPLC online method were further compared to results obtained by liquid&–liquid extraction with stable isotope dilution analysis LC-MS/MS and found to be in good agreement. The developed SPE-HPLC online system with fluorescence detection allows a reliable, accurate, and sensitive quantification (limit of quantification, 30 µg/kg) of ZEN in edible oils while significantly reducing the workload. To our knowledge, this is the first report on an automated SPE-HPLC method based on a covalent SPE approach. KW - Dynamic covalent hydrazine chemistry (DCHC) KW - Maize germ oil KW - Food KW - Mycotoxin KW - ZEA KW - Isomerisation KW - Occurrence KW - Edible oil KW - SIDA KW - LC-MS/MS KW - Quantification PY - 2015 DO - https://doi.org/10.1007/s00216-015-8541-5 SN - 1618-2642 SN - 1618-2650 VL - 407 IS - 12 SP - 3489 EP - 3497 PB - Springer CY - Berlin AN - OPUS4-33067 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schlick-Hasper, Eva A1 - Bethke, John A1 - Jahnke, Wolfgang A1 - Goedecke, Thomas A1 - Kraume, M. T1 - Normale Beförderungsbedingungen beim Gefahrguttransport im Frachtcontainer und ihr Einfluss auf den inneren Überdruck in Gefahrgutverpackungen N2 - Der innere Überdruck, der sich unter Beförderungsbedingungen im freien Dampfraum einer Gefahrgutverpackung bildet, die mit einer gefährlichen Flüssigkeit gefüllt ist, hängt von verschiedenen Faktoren ab: Den spezifischen Stoffeigenschaften des jeweiligen Füllguts, dem Füllgrad, der Nachgiebigkeit der Verpackungsbauart, der Befülltemperatur und der Temperatur bei Beförderungsbedingungen. Zu den normalen Beförderungsbedingungen von befüllten Gefahrgutverpackungen zählt der interkontinentale Transport in Frachtcontainern. Es werden die Ergebnisse einer Klimamessfahrt vorgestellt, die mit einem instrumentierten Frachtcontainer auf der Fahrt von Hamburg nach Singapur und zurück gewonnen wurden. Hierdurch lassen sich durchschnittliche und maximale Beförderungstemperaturen beim interkontinentalen Containertransport ermitteln. Es werden Modellgleichungen vorgestellt, mit denen sich für verschiedene Annahmen der sich einstellende Überdruck in einer Gefahrgutverpackung berechnen lässt. T2 - 44. Jahrestagung der GUS 2015 CY - Stutensee-Blankenloch, Germany DA - 25.03.2015 KW - Gefahrgutverpackungen KW - Frachtcontainer KW - Überdruck PY - 2015 SN - 978-3-9816286-4-7 SP - 179 EP - 193 AN - OPUS4-33072 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CHAP A1 - Jakubowski, Norbert A1 - Horsky, M. A1 - Roos, P.H. A1 - Vanhaecke, F. A1 - Prohaska, T. ED - Prohaska, T. ED - Irrgeher, J. ED - Zitek, A. ED - Jakubowski, Norbert T1 - Inductively coupled plasma mass spectrometry N2 - ICP-MS is based on the formation of (preferentially monovalent positively)charged atomic ions in an inductively coupled Ar plasma at almost 10 000 K. The ions formed are transferred from the plasma source at ambient pressure into a mass Separator operated at high vacuum via a set of cones. The ions are separate«! according to their mass/charge ratio in the mass Separator (quadrupole, magnetic sector field or time-of-flight mass Separator). In most cases, the ions are detected using a secondaiy electron multiplier; in some set-ups (also) a Faraday cup can be used. Single-collector (scanning mass spectrometer usually used for quantitative elemental analysis) or multicollector (static Operation of mass spectrometer for precise isotope ratio analysis) configurations can be found. PY - 2015 SN - 978-1-84973-392-2 SN - 978-1-84973-540-7 SN - 2044-253X N1 - Serientitel: New developments in mass spectrometry – Series title: New developments in mass spectrometry Vollständiges Belegexemplar liegt nur beim Autor vor! VL - 3 SP - Chapter 12, 208 EP - 318 CY - Cambridge, UK AN - OPUS4-33074 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Burkert, Andreas A1 - Lehmann, Jens T1 - KorroPad - ein Korrosionsschnelltest zur Bewertung der Passivschichtqualität N2 - Bei Einsatz und Verarbeitung nichtrostender Stähle ist die Ausbildung der Passivschicht eine der Kernfragen. Dabei stehen die Fragen, wann sich die Passivschicht ausreichend schützend ausgebildet hat ebenso im Raum, wie die Frage, wodurch sich die Passivschichtausbildung in einem Verarbeitungsprozess positiv beeinflussen lässt. Bislang übliche und bekannte Methoden (z.B. Salzsprühnebelprüfung, elektrochemische Prüfungen) können diese Fragen beantworten, stellen jedoch gerade für kleine und mittelständische Unternehmen eine nicht unerhebliche finanzielle Hürde dar, da für die Durchführung und Bewertung neben der Geräteausstattung entsprechende Spezialisten benötigt werden. Zudem sind diese Prüfungen zerstörend und dauern meist mehrere Stunden bis Tage. Für den Großteil der Anwender und Verarbeiter nichtrostender Stähle sind diese Randbedingungen unbefriedigend und eine Prüfung unter praktischen Gesichtspunkten damit nicht realisierbar. So wird in diesem Bereich vielfach auf betriebsinterne Erfahrungen und das riskante Prinzip Hoffnung gesetzt. KW - KorroPad KW - Korrosion KW - Nichtrostender Stahl KW - Prüfung PY - 2015 SN - 2191-0073 VL - 5 IS - 4 SP - 26 EP - 29 PB - Springer-VDI-Verl. CY - Düsseldorf AN - OPUS4-33063 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Mielentz, Frank A1 - Feller, Viktor A1 - Krause, Martin A1 - Orglmeister, R. T1 - Ultraschallprüfung von Betonbauteilen - laufzeitgesteuerte Gruppenstrahler mit Punktkontaktprüfköpfen N2 - In den letzten Jahren werden vermehrt trocken ankoppelbare Ultraschall-Punktkontaktprüfköpfe erfolgreich für Prüfaufgaben im Bauwesen angewendet. Oft werden mehrere Punktkontaktprüfköpfe in einem Gehäuse zu einer Strahlergruppe kombiniert, um die Schallbündelung zu verbessern oder um einzelne Prüfköpfe nacheinander als Sender und Empfänger zu betreiben und die Messsignale nach der Messung einer SAFT-Auswertung zuzuführen. Alternativ können die einzelnen Prüfköpfe einer solchen Gruppe laufzeitgesteuert angeregt und dadurch schon während der Messung das Prüfkopfschallfeld beeinflusst werden. Für diese Technik sind die Bezeichnungen laufzeitgesteuerte Ultraschall-Gruppenstrahler oder 'Phased Array' gebräuchlich. Mit den präsentierten Untersuchungen sollen die Anwendungsmöglichkeiten der Gruppenstrahlertechnik im Niederfrequenzbereich durch den Einsatz von Punktkontaktprüfköpfen verbessert werden. Dazu werden verschiedene Wellenarten eingesetzt und der Einfluss der Anordnung der Strahlerelemente im Array untersucht. KW - Ultra sonic testing KW - Concrete KW - Phased array KW - Point contact probes KW - Beton KW - Ultraschallprüfung KW - Laufzeitgesteuerte Gruppenstrahler KW - Punktkontaktprüfköpfe PY - 2015 UR - http://www.hanser-elibrary.com/doi/pdf/10.3139/120.110723 SN - 0025-5300 VL - 57 IS - 4 SP - 329 EP - 336 PB - Hanser CY - München AN - OPUS4-33064 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kaltenbach, A. A1 - Nordmann, J. A1 - Görlitz, V. A1 - Pape, C. A1 - Richter, Silke A1 - Kipphardt, Heinrich A1 - Kopp, G. A1 - Jährling, R. A1 - Rienitz, O. A1 - Güttler, B. T1 - Gravimetric preparation and characterization of primary reference solutions of molybdenum and rhodium N2 - Gravimetrically prepared mono-elemental reference solutions having a well-known mass fraction of approximately 1 g/kg (or a mass concentration of 1 g/L) define the very basis of virtually all measurements in inorganic analysis. Serving as the starting materials of all standard/calibration solutions, they link virtually all measurements of inorganic analytes (regardless of the method applied) to the purity of the solid materials (high-purity metals or salts) they were prepared from. In case these solid materials are characterized comprehensively with respect to their purity, this link also establishes direct metrological traceability to The International System of Units (SI). This, in turn, ensures the comparability of all results on the highest level achievable. Several national metrology institutes (NMIs) and designated institutes (DIs) have been working for nearly two decades in close cooperation with commercial producers on making an increasing number of traceable reference solutions available. Besides the comprehensive characterization of the solid starting materials, dissolving them both loss-free and completely under strict gravimetric control is a challenging problem in the case of several elements like molybdenum and rhodium. Within the framework of the European Metrology Research Programme (EMRP), in the Joint Research Project (JRP) called SIB09 Primary standards for challenging elements, reference solutions of molybdenum and rhodium were prepared directly from the respective metals with a relative expanded uncertainty associated with the mass fraction of Urel(w)<0.05 %. To achieve this, a microwave-assisted digestion procedure for Rh and a hotplate digestion procedure for Mo were developed along with highly accurate and precise inductively coupled plasma optical emission spectrometry (ICP OES) and multicollector inductively coupled plasma mass spectrometry (MC-ICP-MS) methods required to assist with the preparation and as dissemination tools. KW - Digestion KW - Rhodium KW - Molybdenum KW - Reference solution KW - Metrological traceability KW - ICP OES KW - MC-ICP-MS PY - 2015 DO - https://doi.org/10.1007/s00216-014-8395-2 SN - 1618-2642 SN - 1618-2650 VL - 407 IS - 11 SP - 3093 EP - 3102 PB - Springer CY - Berlin AN - OPUS4-33065 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Helmerich, Rosemarie A1 - Milmann, Boris A1 - Wöstmann, Jens T1 - Non-destructive detection of surface-bond defects in carbon composite-strengthened concrete structures N2 - For almost 15 years, carbon fibre-reinforced polymer (CFRP) plates and sheets have been used for strengthening and repair of civil engineering structures. CFRP plates were applied to upgrade structures for change in use or increasing traffic load. CFRP laminates have also been used to repair deteriorated structures such as multi-storey parking or bridges. The execution quality and condition of the strengthening measure in terms of bond integrity were neither monitored nor tested systematically. Inspectors eventually applied simple hammer knocking during regular main inspection for subjective noise distinction as a measure for eventual insufficient bond. This paper presents the feasibility and the limitations of low-frequency transversal ultrasonic waves with dry-coupling point-contact sensors for inspection and defect detection between CFRP laminate and concrete surfaces. The German Centre of Competence in Civil Engineering (DIBt) has initiated a national research project [Helmerich et al. (2012). Condition analysis of bonded CFRP-applications on concrete structures by means of non-destructive testing [in German: Zustandsuntersuchung von CFK-Klebeverstärkungen an Betonbauteilen mittels zerstörungsfreier Prüfung (ZfP)]. Final, internal project report], carried out at the Federal Institute for Materials Research and Testing (BAM), Germany. The aim of the project was to present a potential non-destructive testing method for bond defect detection as a measure for the durability of the strengthening system more than 10 years after application. KW - Concrete bridges KW - Strengthening KW - Non-destructive testing KW - Composite materials KW - Durability KW - Inspection PY - 2015 DO - https://doi.org/10.1080/15732479.2013.879322 SN - 1573-2479 VL - 11 IS - 1 SP - 3 EP - 14 PB - Taylor & Francis CY - London [u.a.] AN - OPUS4-33086 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Elordui-Zapatarietxe, S. A1 - Fettig, Ina A1 - Philipp, Rosemarie A1 - Gantois, F. A1 - Lalère, B. A1 - Swart, C. A1 - Petrov, P. A1 - Goenaga-Infante, H. A1 - Vanermen, G. A1 - Boom, G. A1 - Emteborg, H. T1 - Novel concepts for preparation of reference materials as whole water samples for priority substances at nanogram-per-liter level using model suspended particulate matter and humic acids N2 - One of the unresolved issues of the European Water Framework Directive is the unavailability of realistic water reference materials for the organic priority pollutants at low nanogram-per-liter concentrations. In the present study, three different types of ready-to-use water test materials were developed for polycyclic aromatic hydrocarbons (PAHs), polybrominated diphenyl ethers (PBDEs) and tributyltin (TBT) at nanogram-per-liter levels. The first type simulated the dissolved phase in the water and comprised of a solution of humic acids (HA) at 5 mg L-1 dissolved organic carbon (DOC) and a spike of the target compounds. The second type of water sample incorporated the particulate phase in water. To this end, model suspended particulate matter (SPM) with a realistic particle size was produced by jet milling soil and sediments containing known amounts of PAHs, PBDEs and TBT and added as slurry to mineral water. The most complex test materials mimicked 'whole water' consequently containing both phases, the model SPM and the HA solution with the target analytes strongly bound to the SPM. In this paper, the development of concepts, processing of the starting materials, characterisation of the HA and model SPMs as well as results for homogeneity and stability testing of the ready-to-use test materials are described in detail. KW - Slurry KW - PBDE KW - PAH KW - TBT KW - Reference materials KW - Suspended particulate matter KW - Whole water KW - Water Framework Directive PY - 2015 DO - https://doi.org/10.1007/s00216-014-8349-8 SN - 1618-2642 SN - 1618-2650 VL - 407 IS - 11 SP - 3055 EP - 3067 PB - Springer CY - Berlin AN - OPUS4-33087 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Bajer, Kamila A1 - Braun, Ulrike A1 - Hintersteiner, I. T1 - The memory effect in polyolefinic products: A tool for confirming the steam sterilization process N2 - DSC-Messungen von dampfsterilisierten medizinischen Produkten aus Polyolefinen zeigen beim ersten Heizvorgang als auffällige Besonderheit eine zusätzliche Stufe, bekannt als Temperpeak. Das Ziel dieser Untersuchungen ist, dieses Phänomen nachzuvollziehen und zu verstehen, um es als Nachweis für die Dampfsterilisation nutzen zu können. Dafür wurden PP- und PE-Proben unter verschiedenen Bedingungen dampfsterilisiert und im Ofen thermisch behandelt. Anschließend wurden die Proben mittels DSC untersucht und die Einflüsse der thermischen Behandlung und der mechanischen Beanspruchung analysiert. Um den Einfluss unterschiedlicher Materialspezifikationen zu prüfen, wurden zusätzlich verschiedene Referenzmaterialien (PE und PP) untersucht und GPC-Messungen durchgeführt. Des Weiteren wurde die Beständigkeit des Signals gegenüber der Zeit und der Temperatureinflüssen betrachtet. Die Untersuchungen zeigen, dass sich ein stabiler Memory-Effekt erzeugen lässt. KW - Memory effect KW - Steam sterilization KW - Polypropylene KW - Polyethylene KW - DSC PY - 2015 DO - https://doi.org/10.3139/120.110722 SN - 0025-5300 VL - 57 IS - 4 SP - 316 EP - 323 PB - Hanser CY - München AN - OPUS4-33104 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Bannick, Claus Gerhard A1 - Bierl, R. A1 - Braun, Ulrike A1 - Brand, K. A1 - Dümichen, Erik A1 - Jekel, M. A1 - Klein, S. A1 - Knepper, T.P. A1 - König, F. A1 - Miklos, D. A1 - Rechenberg, B. A1 - Steffens, I. T1 - Mikroplastik in der aquatischen Umwelt - Ein Beitrag zur aktuellen Diskussion in Deutschland N2 - Plastics are important materials in households and industry and therefore a crucial part of our everyday life. Since the beginning of the 1970s the occurrence of plastic particles in coastal waters has been explicitly described. Meanwhile, besides the marine environment, microplastics were also detected in other environmental media, biota and water management facilities. This work gives an overview of the occurrence and first known effects of microplastics in the environment. Furthermore, current scientific proceedings are considered and pending issues are discussed. In this regard it is of central importance to develop an environmentally comprehensive, harmonized scientific proceeding for miroplastics, which enables an evaluation of relevant material flows in adaption to necessary assessment concepts. N2 - Kunststoffe sind wichtige Werkstoffe und heutzutage aus Haushalt und Wirtschaft nicht mehr wegzudenken. Seit Anfang der 1970er-Jahre wird das Vorkommen von Kunststoffpartikeln in Küstengewässern beschrieben. Inzwischen ist Mikroplastik nicht nur im marinen Bereich, sondern auch in weiteren Umweltkompartimenten, Biota und technischen Einrichtungen der Wasserwirtschaft nachgewiesen worden, in dieser Arbeit wird ein Überblick über das Vorkommen von Mikroplastik in der aquatischen Umwelt und ersten bekannten Auswirkungen gegeben. Darüber hinaus werden die aktuellen Untersuchungsverfahren von Probenahme, Probenaufbereitung und Analytik betrachtet und offene fragen diskutiert. Zentral erscheint in diesem Zusammenhang die Entwicklung einer harmonisierten medienübergreifenden Untersuchungsmethodik, die eine Auswertung relevanter Stoffströme ermöglicht und auf notwendige Bewertungskonzepte abgestimmt ist. KW - Water management KW - Plastics KW - Microplastics KW - Environment KW - Analysis KW - Mikroplastik KW - Kunststoff KW - Wasserwirtschaft KW - Analytik KW - Umwelt PY - 2015 SN - 0083-6915 VL - 113 IS - 1 SP - 7 EP - 14 PB - Wiley-VCH Verl. CY - Weinheim AN - OPUS4-33105 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kolkoori, Sanjeevareddy A1 - Venkata, K.C. A1 - Balasubramaniam, Krishnan T1 - Quantitative simulation of ultrasonic time of flight diffraction technique in 2D geometries using Huygens-Fresnel diffraction model: Theory and experimental comparison N2 - This article presents an analytical approach for simulation of ultrasonic diffracted wave signals from cracks in two-dimensional geometries based on a novel Huygens–Fresnel Diffraction Model (HFDM). The model employs the frequency domain far-field displacement expressions derived by Miller and Pursey in 2D for a line source located on the free surface boundary of a semi-infinite elastic medium. At each frequency in the bandwidth of a pulsed excitation, the complex diffracted field is obtained by summation of displacements due to the unblocked virtual sources located in the section containing a vertical crack. The time-domain diffracted wave signal amplitudes in a general isotropic solid are obtained by standard Fast Fourier Transform (FFT) procedures. The wedge based finite aperture transducer refracted beam profiles were modelled by treating the finite dimension transducer as an array of line sources. The proposed model is able to evaluate back-wall signal amplitude and lateral wave signal amplitude, quantitatively. The model predicted range-dependent diffracted amplitudes from the edge of a bottom surface-breaking crack in the isotropic steel specimen were compared with Geometrical Theory of Diffraction (GTD) results. The good agreement confirms the validity of the HFDM method. The simulated ultrasonic time-of-flight diffraction (TOFD) A-scan signals for surface-breaking crack lengths 2 mm and 4 mm in a 10 mm thick aluminium specimen were compared quantitatively with the experimental results. Finally, important applications of HFDM method to the ultrasonic quantitative non-destructive evaluation are discussed. KW - Ultrasonic non-destructive evaluation KW - Time-of-flight diffraction (TOFD) KW - Huygens–Fresnel diffraction KW - Cracks KW - Virtual sources PY - 2015 DO - https://doi.org/10.1016/j.ultras.2014.08.016 SN - 0041-624x VL - 55 SP - 33 EP - 41 PB - Elsevier B.V. CY - Amsterdam AN - OPUS4-32240 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Gravenkamp, Hauke A1 - Birk, C. A1 - Van, J. T1 - Modeling ultrasonic waves in elastic waveguides of arbitrary cross-section embedded in infinite solid medium N2 - An approach is presented to model elastic waveguides of arbitrary cross-section coupled to infinite solid media. The formulation is based on the scaled boundary-finite element method. The surrounding medium is approximately accounted for by a dashpot boundary condition derived from the acoustic impedances of the infinite medium. It is discussed under which circumstances this approximation leads to sufficiently accurate results. Computational costs are very low, since the surrounding medium does not require discretization and the number of degrees of freedom on the cross-section is significantly reduced by utilizing higher-order spectral elements. KW - Guided waves KW - Scaled boundary finite element method KW - Leaky waves KW - Ultrasound PY - 2015 DO - https://doi.org/10.1016/j.compstruc.2014.11.007 SN - 0045-7949 SN - 0366-7138 VL - 149 SP - 61 EP - 71 PB - Pergamon Press CY - Oxford AN - OPUS4-32348 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Despinasse, Marie-Claire A1 - Krüger, Simone T1 - First developments of a new test to evaluate the fire behavior of photovoltaic modules on roofs N2 - A new test for photovoltaic (PV) modules exposed to an external fire source on roofs is proposed, and first results are presented. This is a simplification of the standards commonly in use for testing PV modules as roofing parts, roofing components or building components. Most of the tests required different fire scenarios and the use of burning brands such as wood cribs. In our study we proposed replacing wooden burning brands with a propane burner, the output of which is close to the one that can be observed in the burning of wooden cribs 500 g and 2 kg in size. The fire behavior was assessed by measuring smoke evolution, burning drips, flaming debris, and the time to burn-through of monocrystalline, polycrystalline and amorphous silicon panels. Two different configurations of the burner were tested, with the fire source on the top of the module or under the tilted module, respectively. The fire behavior of the modules was dependent on the burner output (16 to 46 kW), but also on the construction type of the panel (glass/glass or glass/plastic sheet) and on the position of the fire source (top or bottom). These preliminary tests for further development of the procedure yielded encouraging results for the evaluation of PV panels on roofs. KW - Fire test KW - Photovoltaics KW - Roofs KW - Temperature measurements KW - Fire behavior KW - Fire engineering KW - Burn-through PY - 2015 DO - https://doi.org/10.1016/j.firesaf.2014.11.011 SN - 0379-7112 VL - 71 SP - 49 EP - 57 PB - Elsevier Ltd. CY - Kidlington, Oxford AN - OPUS4-32160 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Rahammer, M. A1 - Myrach, Philipp A1 - Maierhofer, Christiane A1 - Busse, G. A1 - Kreutzbruck, M. T1 - Auflösungsgrenzen der Lockin-Thermografie zur Prüfung von Faserkunststoffverbunden N2 - Aktive Thermografie mit Lockin-Anregung ist ein zerstörungsfreies Prüfverfahren, das insbesondere auch die Prüfung von kohlenstofffaserverstärkten Kunststoffen ermöglicht. Um eine Standardisierung dieses Verfahrens voranzubringen, wurden im Rahmen eines Forschungsprojektes umfangreiche Untersuchungen zur Validierung des Verfahrens durchgeführt. Für die Anregungsmethoden optisch und Ultraschall wurden die wichtigsten Parameter systematisch untersucht. Auf der Auswertungsseite ist dies z.B. der Einfluss der spektralen Empfindlichkeit verschiedener Kamerasysteme. Für die Anregungen sind unter anderem die Einflüsse von Anregungsenergie und Ultraschallfrequenz untersucht worden. Auch Materialparameter, wie der Lagenaufbau bei CFK-Probekörpern, beeinflussen die Ergebnisse stark. T2 - 24. Stuttgarter Kunststoffkolloquium CY - Stuttgart, Germany DA - 25.02.2015 KW - Zerstörungsfreie Prüfung KW - Lockin-Thermografie KW - Faserkunststoffverbunde KW - Non-destructive testing KW - Lockin-Thermography KW - Fibre-reinforced plastics PY - 2015 SP - 1 EP - 7 AN - OPUS4-32876 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Hu, Wei-Hua A1 - Thöns, Sebastian A1 - Rohrmann, Rolf A1 - Said, Samir A1 - Rücker, Werner T1 - Vibration-based structural health monitoring of a wind turbine system. Part I: Resonance phenomenon N2 - This paper is focused on a resonance phenomenon of a wind turbine system in 5 MW class, on the basis of dynamic signals acquired continuously from the tubular tower under normal operational conditions during two years. Firstly, technique specifications of the wind turbine system are introduced and a finite element model is developed to characterize the structural dynamic properties. The following part describes the continuous dynamic monitoring system integrated with an automated operational modal analysis procedure using the poly-reference Least Squares Complex Frequency domain (p-LSCF) method. Subsequently, variations and mutual relationships of environmental/operational factors such as vibration amplitude, temperature, wind speed, rotation speed of blades, pitch angle and nacelle direction are also presented. Finally, significant resonance is observed due to the fundamental frequency of the tower matching with the harmonic frequency induced by the rotation of three blades. As the rotation speed of rotor approaches to 8 rpm, the vibration amplitude of the tower increases significantly and the corresponding damping value decreases. With the further rising wind velocity, the rotation speed of blades stops increasing and the input energy just contribute to accumulate the vibration amplitude of tower. Such observation indicates the Sommerfeld effect that aggravates the resonance phenomenon. A vibration control device is necessary to minimize the excessive structural responses. A companion paper will further discuss the environmental/operational effects on dynamic properties of the wind turbine system under the operational conditions. KW - Vibration KW - Structural health monitoring KW - Wind turbine KW - Automated operational modal analysis KW - Resonance KW - Sommerfeld effect PY - 2015 DO - https://doi.org/10.1016/j.engstruct.2014.12.034 SN - 0141-0296 VL - 89 SP - 260 EP - 272 PB - Elsevier Ltd. CY - Oxford AN - OPUS4-32878 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Hu, Wei-Hua A1 - Thöns, Sebastian A1 - Rohrmann, Rolf A1 - Said, Samir A1 - Rücker, Werner T1 - Vibration-based structural health monitoring of a wind turbine system. Part II: Environmental/operational effects on dynamic properties N2 - The second part of these companion papers mainly researches environmental/operational influences on structural dynamic properties under normal operational conditions during two years, in order to extract a statistical based damage-sensitive indicator for health monitoring of a wind turbine system. The correlation analyses between experimental identified frequencies, damping values as well as mode shapes and environmental/operational factors such as rotation speed of blades, wind speed, pitch angle, temperature and nacelle direction are presented. It is observed that the frequency estimates are influenced by the nacelle position, the activation of rotor, the rotation speed of blades and the wind speed as well as the temperature. Regarding to the damping estimates, they are mainly associated with variation of the aerodynamic damping due to the increasing wind speed. Besides, the resonance phenomenon is also observed in higher modes. The harmonic frequencies due to blades passing by tower are found and the corresponding damping value decreases. Moreover, the mode shapes in some modes are strongly affected by the position of the nacelle. Subsequently, two types of simulated damage including the reduction of stiffness in both the rotor blade and the tubular tower are successfully detected by applying the Principal Component Analysis (PCA) based methods to these temperature-sensitive frequency estimates. Comparison of change of the extracted health features indicates that they are more sensitive with the tower damage. KW - Vibration KW - Structural health monitoring KW - Wind turbine KW - Environmental/operational effects KW - Modal properties KW - Principal Component Analysis KW - Novelty analysis KW - Damage detection KW - Sommerfeld effect KW - Automated operational modal analysis KW - Resonance PY - 2015 DO - https://doi.org/10.1016/j.engstruct.2014.12.035 SN - 0141-0296 VL - 89 SP - 273 EP - 290 PB - Elsevier Ltd. CY - Oxford AN - OPUS4-32879 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Flohr, S. A1 - Brinker, U. A1 - Schramm, A. A1 - Kierdorf, U. A1 - Staude, Andreas A1 - Piek, J. A1 - Jantzen, D. A1 - Hauenstein, K. A1 - Orschiedt, J. T1 - Flint arrowhead embedded in a human humerus from the Bronze Age site in the Tollense valley, Germany - A high-resolution micro-CT study to distinguish antemortem from perimortem projectile trauma to bone N2 - The Bronze Age site in the Tollense valley, Germany, has yielded thousands of human and animal bones and a number of archaeological artifacts. Several of the human bones exhibit blunt and sharp force lesions, and the assemblage has been interpreted as representing victims of a large scale conflict. One of the earliest finds is a human humerus with an embedded flint arrowhead. Alleged signs of healing initially reported for this humerus based on clinical CT imaging were interpreted as evidence of an antemortem lesion. The present study, using micro-CT imaging, revealed that the arrowhead lesion in the humerus, contrary to the previous interpretation, shows no signs of healing. The structure previously assumed to represent a sclerotic margin around the wound canal was shown to actually represent compacted trabecular debris. Thus, our re-analysis of the specimen led to a re-classification of the arrow wound as a perimortem lesion. The findings of the present study demonstrate the value of micro-CT imaging as a non-destructive method for obtaining information on the nature of bone lesions and healing reactions critical for the reconstruction of interpersonal conflict scenarios in the past. KW - Arrow wound KW - Differential diagnosis KW - Prehistoric warfare KW - Antemortem and perimortem lesions KW - Trauma PY - 2015 DO - https://doi.org/10.1016/j.ijpp.2015.02.004 SN - 1879-9817 VL - 9 SP - 76 EP - 81 PB - Elsevier Inc. AN - OPUS4-32881 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Müller, M.E.H. A1 - Urban, K. A1 - Köppen, Robert A1 - Siegel, David A1 - Korn, U. A1 - Koch, Matthias T1 - Mycotoxins as antagonistic or supporting agents in the interaction between phytopathogenic Fusarium and Alternaria fungi N2 - The role of mycotoxins in the microbial competition in an ecosystem or on the same host plant is still unclear. Therefore, a laboratory study was conducted to evaluate the influence of mycotoxins on growth and mycotoxin production of Fusarium and Alternaria fungi. Fusarium culmorum Fc13, Fusarium graminearum Fg23 and two Alternaria tenuissima isolates (At18 and At220) were incubated on wheat kernels supplemented with alternariol (AOH), tetramic acid derivates (TeA), deoxynivalenol (DON) and zearalenone (ZEA) in an in vitro test system. Fungal biomass was quantified by determining ergosterol content. Three Fusarium toxins (DON, nivalenol and ZEA) and three Alternaria toxins (AOH, alternariol methyl ether (AME) and altenuene) were analysed by HPLC-MS/MS. If Alternaria strains grew in wheat kernels spiked with Fusarium mycotoxins, their growth rates were moderately increased, their AOH and AME production was enhanced and they were simultaneously capable of degrading the Fusarium mycotoxins DON and ZEA. In contrast, both Fusarium strains behaved quite differently. The growth rate of Fc13 was not distinctly influenced, while Fg23 increased its growth in wheat kernels spiked with AOH. TeA depressed the ergosterol content in Fc13 as well as in Fg23. The DON production of Fc13 was slightly depressed, whereas the ZEA production was significantly increased. In contrast, Fg23 restricted its ZEA production. Both Fusarium strains were not capable of degrading the Alternaria mycotoxin AOH. Mycotoxins might play an important role in the interfungal competitive processes. They influence growth rates and mycotoxin production of the antagonistic combatants. The observed effects between phytopathogenic Alternaria and Fusarium strains and their mycotoxins aid the understanding of the complexity of microbial competitive behaviour in natural environments. KW - Phytopathogen KW - Trichothecenes KW - Alternaria mycotoxins KW - Multi-mycotoxin analysis KW - Inter-fungal competition PY - 2015 DO - https://doi.org/10.3920/WMJ2014.1747 SN - 1875-0710 SN - 1875-0796 VL - 8 IS - 3 SP - 311 EP - 321 PB - Wageningen Academic Publishers CY - Wageningen AN - OPUS4-32849 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - McMahon, Dino Peter A1 - Fürst, M.A. A1 - Caspar, J. A1 - Theodorou, P. A1 - Brown, M.J.F. A1 - Paxton, R.J. T1 - A sting in the spit: widespread cross-infection of multiple RNA viruses across wild and managed bees N2 - 1.Declining populations of bee pollinators are a cause of concern, with major repercussions for biodiversity loss and food security. RNA viruses associated with honeybees represent a potential threat to other insect pollinators, but the extent of this threat is poorly understood. 2.This study aims to attain a detailed understanding of the current and ongoing risk of emerging infectious disease (EID) transmission between managed and wild pollinator species across a wide range of RNA viruses. 3.Within a structured large-scale national survey across 26 independent sites, we quantify the prevalence and pathogen loads of multiple RNA viruses in co-occurring managed honeybee (Apis mellifera) and wild bumblebee (Bombus spp.) populations. We then construct models that compare virus prevalence between wild and managed pollinators. 4.Multiple RNA viruses associated with honeybees are widespread in sympatric wild bumblebee populations. Virus prevalence in honeybees is a significant predictor of virus prevalence in bumblebees, but we remain cautious in speculating over the principle direction of pathogen transmission. We demonstrate species-specific differences in prevalence, indicating significant variation in disease susceptibility or tolerance. Pathogen loads within individual bumblebees may be high and in the case of at least one RNA virus, prevalence is higher in wild bumblebees than in managed honeybee populations. 5.Our findings indicate widespread transmission of RNA viruses between managed and wild bee pollinators, pointing to an interconnected network of potential disease pressures within and among pollinator species. In the context of the biodiversity crisis, our study emphasizes the importance of targeting a wide range of pathogens and defining host associations when considering potential drivers of population decline. KW - Apis KW - Bombus KW - Decline KW - Pathogen KW - Spillover PY - 2015 DO - https://doi.org/10.1111/1365-2656.12345 SN - 1365-2656 SN - 0021-8790 VL - 84 SP - 615 EP - 624 PB - Wiley-Blackwell CY - Oxford [u.a.] AN - OPUS4-32885 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Wollschläger, Nicole A1 - Österle, Werner A1 - Häusler, Ines A1 - Stewart, M. T1 - Ga+ implantation in a PZT film during focused ion beam micro-machining N2 - The objective of the present work was to study the impact of Focused Ion Beam (FIB) machining parameters on the thickness of the damaged layer within a thin film PZT. Therefore, different Ga+- ion doses and ion energies were applied to a standard PZT film (80/20 lead zirconium titanate) under two beam incidence angles (90° and 1°). The thicknesses of the corresponding Ga+-implanted layers were then determined by cross-sectional TEM in combination with energy dispersive spectroscopic (EDS) line-scans and correlated with polarisation hysteresis loops. The results show a decrease of Ga+-implanted layer thickness with decreasing inclination angle, whereas ion energy and ion dose could be correlated with gallium concentration in the implanted layers.. Under the most unfavorable conditions the depth of the affected zone was 26 nm, it was only 2 nm for the most favorable conditions. KW - PZT KW - Focused ion beam KW - Gallium implantation KW - Polarisation-electric field loop PY - 2015 DO - https://doi.org/10.1002/pssc.201400096 SN - 1610-1634 SN - 1862-6351 SN - 1610-1642 VL - 12 IS - 3 SP - 314 EP - 317 PB - Wiley-VCH CY - Berlin AN - OPUS4-32872 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Woydt, Mathias A1 - Mohrbacher, H. T1 - The use of niobium carbide (NbC) as cutting tools and for wear resistant tribosystems N2 - The tribological profile of alumina (99.7%) mated against rotating disks made in binder-less niobium carbide (NbC) and cobalt-bonded NbC were determined under unidirectional sliding tests (0.1 m/s to 8.0 m/s; 22 °C and 400 °C) as well as in oscillation tests (f = 20 Hz, Δx = 0.2 mm, 2/50/98% rel. humidity, n = 105/106 cycles) under unlubricated (dry) conditions. In addition, the microstructure and mechanical properties of binderless NbC and NbC bonded with 8% cobalt were determined as well. The reason for testing hot-pressed NbC was to avoid side effects generated by sintering additives and/or second phases. The tribological data obtained were benchmarked with different ceramics, cermets and thermally sprayed coatings. NbC and cobalt-bonded NbC exhibited low wear rates under dry sliding associated with high load carrying capacity. The tribological profile established revealed a strong position of NbC bearing materials under tribological considerations and for closed tribo-systems against traditional references, such as WC, Cr3C2 and (Ti,Mo)(C,N). KW - Sliding friction KW - Sliding wear KW - Ceramic KW - Oscillation KW - Coating KW - NbC KW - Niobium carbide KW - Hard metal KW - Cobalt PY - 2015 DO - https://doi.org/10.1016/j.ijrmhm.2014.07.002 SN - 0263-4368 SN - 0958-0611 VL - 49 SP - 212 EP - 218 PB - Elsevier AN - OPUS4-32896 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Dittrich, Matthias A1 - Schumacher, G. T1 - Evolution of crystallite size, lattice parameter and internal strain in Al precipitates during high energy ball milling of partly amorphous Al87Ni8La5 alloy T2 - 79. Jahrestagung der DPG und DPG-Frühjahrstagung CY - Berlin, Germany DA - 2015-03-15 PY - 2015 AN - OPUS4-32923 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Nehrig, Marko A1 - Wille, Frank A1 - Feldkamp, Martin A1 - Rolle, Annette T1 - Aspects of gas generation caused by residual water inside ILW packages N2 - Packages for intermediate level waste (ILW) often contain residual water besides the actual waste. The water either exists as obvious free water or it may be bound physically or chemically, e.g. as pore water. Water driven gas generation could occur by vaporisation and by radiolysis. Steam as the result of vaporisation causes an increasing pressure inside a package and can affect corrosion. Vaporisation and condensation processes itself change the thermal behaviour of the content especially during strongly unsteady thermal situations like accident fire situations. Radiolysis changes the chemical composition of the content which could cause an unexpected interaction, e.g. hydrogen embrittlement. Besides the pressure build-up the radiolysis of water generates hydrogen and oxygen, which can be highly flammable respectively explosive. The gas generation caused by vaporisation and radiolysis must be taken into account during the design and the safety assessment of a package. Pressure build-up, a changed thermal behaviour and content chemistry, and especially the risk of accumulation of combustible gases exceeding the limiting concentration for inflammability has to be considered in the safety assessment. Approaches to ensure the transportability of stored packages due to radiolysis will be discussed. T2 - RAMTRANS 2015 - 10th International conference on radioactive materials transport and storage CY - Oxford, UK DA - 19.05.2015 KW - Typ-B KW - ILW package KW - Gas generation KW - Radiolysis KW - Wet content PY - 2015 SP - 1 EP - 7 AN - OPUS4-33429 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CHAP A1 - Miccoli, Lorenzo A1 - Paganoni, S. A1 - Fontana, Patrick A1 - D'Ayala, D. ED - Jäger, W. T1 - Verpressanker für den Erdbebenschutz von Gebäuden aus Mauerwerk - experimentelle Untersuchungen des Verbundverhaltens N2 - Ziel der Untersuchungen war es, das Verhalten von Verpressankern zu analysieren, die üblicherweise zur Verstärkung der Eckverbindung von Mauerwerkswänden eingesetzt werden. Im Fokus der Untersuchungen stand die Leistungsfähigkeit der Ankersysteme mit Bezug auf die Versagensarten und auf dem Traglastvermögen der Anker bei Ankerauszug durch gleichförmige Zugbelastung, die als Vereinfachung für die dynamische Belastung durch ein Erdbeben aufgebracht wurde. Die hier dargestellten Untersuchungen und Ergebnisse stellen eine Zusammenfassung von Arbeiten dar, über die bereits in Beiträgen berichtet wurde, die zum einen die Prüfverfahren für verstärkte Eckverbindungen von Gebäuden aus Mauerwerk und zum anderen die Verbundfestigkeit von Verpressankern in Wänden aus verschiedenen Lehmbautechniken zum Inhalt hatten. Sie geben dennoch einen Überblick über die Hauptversagensmechanismen von Verpressankersystemen und erweitern den Wissensstand bezüglich der Prüfung von Ankersystemen für Ziegel- und Lehmsteinmauerwerk. Darüber hinaus wird eine Vorgehensweise vorgeschlagen, die es ermöglicht, die Traglast von Verpressankern auf Basis experimenteller Untersuchungen abzuschätzen. KW - Verpressanker KW - Ziegelmauerwerk KW - Lehmsteinmauerwerk KW - Verbundfestigkeit KW - Ankerauszugsversuche KW - Ankertraglast PY - 2015 SN - 978-3-433-03106-3 SN - 0170-4958 SP - Kap. III, 293 EP - 308 PB - Ernst & Sohn AN - OPUS4-33430 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Gappenach, C. A1 - Krauß, H.-J. A1 - Krüger, Jörg A1 - Offenhäuser, F. A1 - Pintaske, S. T1 - Auswahl Laserschutzprodukte - eine Handreichung N2 - Wer mit Laserstrahlung zu tun hat, sollte vor allem auf den Schutz seiner Augen achten, denn die Netzhaut ist eines der empfindlichsten Gewebe des menschlichen Körpers. Auch die Hornhaut des Auges kann durch Laserstrahlung gefährdet sein. Sie hat eine Dicke von nur etwa 0,5 mm. Der Schutz der Augen vor Laserstrahlung ist durch verschiedene Maßnahmen möglich. KW - Laserschutz KW - Schutzbrille KW - Justierbrille KW - Abschirmung KW - EN 207 KW - EN 208 KW - EN 12254 PY - 2015 SN - 1432-9778 VL - 3 SP - 40 EP - 45 PB - AT-Fachverl. CY - Fellbach AN - OPUS4-33431 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Seewald, J.S. A1 - Reeves, E.P. A1 - Bach, W. A1 - Saccocia, P.J. A1 - Craddock, P.R. A1 - Shanks III, W.C. A1 - Sylva, S.P. A1 - Pichler, T. A1 - Rosner, Martin A1 - Walsh, E. T1 - Submarine venting of magmatic volatiles in the Eastern Manus Basin, Papua New Guinea N2 - The SuSu Knolls and DESMOS hydrothermal fields are located in the back-arc extensional transform zone of the Eastern Manus Basin. In 2006, highly acidic and ΣSO4-rich vent fluids were collected at both sites and analyzed for the chemical and isotopic composition of major and trace species. Fluids exiting the seafloor have measured temperatures from 48 to 215 °C and are milky white in appearance due to precipitation of elemental S0. Vent fluid concentrations of Na, K, and Mg are depleted by as much as 30% relative to seawater, but have the same relative abundance. In contrast, the fluids are highly enriched in dissolved ΣCO2, Cl, SiO2(aq), Fe, and Al relative to seawater. Measured pH (25 °C) ranged from 0.95 to 1.87 and aqueous ΣSO4 ranged from 35 to 135 mmol/kg. The chemical and isotopic composition points to formation via subsurface mixing of seawater with a Na-, K-, Mg-, and Ca-free, volatile-rich magmatic fluid exsolved from subsurface magma bodies during a process analogous to subaerial fumarole discharge. Estimates of the magmatic end-member composition indicate a fluid phase where H2O > SO2 > CO2 ≈ Cl > F. The hydrogen and oxygen isotopic composition of H2O and carbon isotopic composition of ΣCO2 in the vent fluids strongly suggest a contribution of slab-derived H2O and CO2 to melts generated in the mantle beneath the Eastern Manus volcanic zone. Abundant magmatically-derived SO2 undergoes disproportionation during cooling in upflow zones and contributes abundant acidity, SO42-, and S0 to the venting fluids. Interaction of these highly acidic fluids with highly altered mineral assemblages in the upflow zone are responsible for extensive aqueous mobilization of SiO2(aq), Fe, and Al. Temporal variability in the speciation and abundance of aqueous S species between 1995 and 2006 at the DESMOS vent field suggests an increase in the relative abundance of SO2 in the magmatic end-member that has mixed with seawater in the subsurface. Results of this study constrain processes responsible for the formation of hot-spring fluids in magmatically active back-arc environments and the resulting chemical exchange between the lithosphere and water column. PY - 2015 DO - https://doi.org/10.1016/j.gca.2015.04.023 SN - 0016-7037 SN - 1872-9533 VL - 163 SP - 178 EP - 199 PB - Elsevier Science CY - New York, NY AN - OPUS4-33433 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Peplinski, Burkhard A1 - Adam, Christian A1 - Adamczyk, Burkart A1 - Müller, Ralf A1 - Michaelis, Matthias A1 - Krahl, T. A1 - Emmerling, Franziska T1 - Nanocrystalline and stacking-disordered beta-cristobalite AlPO4: the now deciphered main constituent of a municipal sewage sludge ash from a full-scale incineration facility N2 - For the first time evidence is provided that a nanocrystalline and stacking-disordered, chemically stabilized β-cristobalite form of AlPO4 occurs in a sewage sludge ash (SSA). This proof is based on a combined X-ray powder diffraction and X-ray fluorescence investigation of an SSA produced at a large-scale fluidized bed incineration facility serving a catching area with a population of 2 million. The structural and chemical characterization was carried out on 'as received' SSA samples as well as on solid residues remaining after leaching this SSA in sodium hydroxide solution. Thus, it was ascertained that the observed nanocrystalline and stacking-disordered cristobalite-like component belongs to the aluminum phosphate component of this SSA, rather than to its silicon dioxide component. In addition, a direct proof is presented that the chemically stabilized β-cristobalite form of AlPO4 does crystallize from X-ray amorphous precursors under conditions that mimic the huge heating rate and short retention time (just seconds at T ≈ 850°C), typical for fluidized bed incinerators. KW - Aluminum phosphate KW - Chemical stabilization of high-temperature forms KW - Cristobalite form KW - Stacking disorder KW - Incinerator ash KW - Sewage sludge ash PY - 2015 DO - https://doi.org/10.1017/S0885715614001213 SN - 0885-7156 VL - 30 IS - Supplement S 1 SP - S31 EP - S35 PB - JCPDS CY - Swarthmore, Pa. AN - OPUS4-33435 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Feldkamp, Martin A1 - Nehrig, Marko A1 - Bletzer, Claus Wilhelm A1 - Musolff, André A1 - Wille, Frank T1 - Combustion of wood encapsulated in steel sheets during fire test N2 - Packages for the transport of radioactive material are often equipped with impact limiters consisting of wood, encapsulated by Steel sheets. These impact limiters shall ensure the transport cask meets the IAEA safety requirements. After damage caused by the mechanical tests the package has to withstand a severe fire scenario. According to the regulations during and following the fire test, the specimen shall not be artificially cooled and any combustion of materials of the package shall be permitted to proceed naturally. Due to results of the French institute IRSN it was shown that after the fire test an additional energy supply from a pre-damaged impact limiter should be taken into account. The combustion or smouldering of wood was of interest. BAM started a first test phase to examine the issue of combustion for such kind of package components. The goal was to understand the phenomena under the consideration of relevant regulatory boundary conditions. Several metal buckets were filled with wood and equipped with thermocouples. The test specimens have been prepared with different damage arrangements to take the influence of the mechanical tests into account. This paper shows the experimental Setup and the conduction of the tests. The first test shows that pre-damaged metal encapsulations can lead to smouldering of the wood and with this to a Supplement energy release after the end of the 30 minute fire. The consequence could be, to consider additional thermal loads of wood filled impact limiters to filled the IAEA regulations, if the conditions of the tests are transferable to the safety analysis of the package design. T2 - RAMTRANS 2015 - 10th International conference on radioactive materials transport and storage CY - Oxford, UK DA - 19.05.2015 KW - Typ-B KW - Impact limiter KW - Shock absorber KW - Wood KW - Thermal test KW - Fire test PY - 2015 SP - 1 EP - 9 AN - OPUS4-33407 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Plarre, Rüdiger A1 - Busweiler, Sabine T1 - Antennen-Anomalie beim Hausbockkäfer Hylotrupes bajulus (Coleoptera: Cerambycidae) N2 - In 2012, the house Ianghorn beetle (Hylotrupes bajulus) breeding culture of the Federal Institute for Materials Research and Testing (BAM) in Berlin produced a female beetle with a unique malformed right antenna. Distal to the pedical, the flageilum was bifurcated into a Ionger branch with the typical 9 flageilomeres and a shorter branch with only 4 flageilomeres. The left antenna of the same animal was normally developed with 11 segments (scape, pedical and 9 flageiiomeres). The malformation is interpreted as "Bruchdreifachbildung" (triplication of structures after damage during metamorphosis). KW - Bruchdreifachbildung KW - Referenzorganismus KW - Zucht PY - 2015 SN - 0037-5942 VL - 51 SP - 55 EP - 58 PB - Goecke & Evers CY - Keltern AN - OPUS4-33408 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Plarre, Rüdiger T1 - Ein Streifzug durch die kulturelle Entomologie N2 - Etymologically, nature and culture are considered to be extreme opposites and the doctrines behind them-the natural sciences and the humanities-seldom overlap. However, at all times nature has influenced culture in many different ways. Cultural entomology describes these influences from the entomological side of view. Insects had and still have an enormous impact on all parts of the human intellectual life including language, literature, music, arts, philosophy, religion, and so on. Additionally, insects have changed the course of history more than once. The following overview presents well-known and less well-known examples of how insects influenced human work. Certainly, some insects like bees, flies and butterflies are more dominant than others in this respect, according to their economic importance, their overall synanthropic presence or simply their beauty. KW - Insekten KW - Kunst KW - Literatur KW - Geschichte KW - Sprache PY - 2015 SN - 0037-5942 VL - 51 SP - 59 EP - 94 PB - Goecke & Evers CY - Keltern AN - OPUS4-33409 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Salg, Steffen A1 - Malow, Marcus A1 - Michael-Schulz, Heike A1 - Gebauer, Marek T1 - Experimentelle und theoretische Untersuchung des Zersetzungsmechanismus deflagrationsfähiger Substanzen N2 - Dieser Beitrag beschreibt Untersuchungen zu Deflagrationen von Azodicarbonamid, welche erstmals in einem Vier-Liter-Autoklaven durchgeführt wurden. Zunächst wird die Reproduzierbarkeit der Messungen mit der neuen Apparatur überprüft. Anschließend wird ein Vergleich mit Messungen in einer offenen Apparatur hergestellt, welche zur Prüfung der Deflagrationsfähigkeit in VDI 2263-1 erläutert ist. Zur Beschreibung der deflagrativen Zersetzungen werden die Kenngrößen Induktionszeit, Deflagrationsgeschwindigkeit, maximaler Druck, maximale und mittlere Druck- und Tempe-raturanstiegsrate herangezogen. Zusätzlich werden in weiteren Versuchen die während einer Deflagration entstehende Gasmenge und die Gasentwicklungsrate bestimmt. Abschließend werden die Druck- und Gasentwicklungsraten miteinander verglichen. Aus den Arbeiten lässt sich folgern, dass der Vier-Liter-Autoklav zur Bestimmung und Beschreibung der Deflagrationsfähigkeit von Azodicarbonamid gut geeignet ist und im Vergleich zu Messungen in offenen Prüfanordnungen eine Reihe von Vorteilen bietet. T2 - 4. Magdeburger Brand- und Explosionsschutztag / 3. vfdb-Workshop Brandschutzforschung CY - Magdeburg, Germany DA - 26.03.2015 KW - Deflagration KW - Geschlossener Behälter KW - Autoklav KW - Gas- und Druckmengenmessung PY - 2015 UR - http://www.iaut.ovgu.de/iaut_media/MBE/4_+MBE+2015/Beitr%C3%A4ge+2015/Salg_Experimentelle+und+theoretische+Untersuchung+des+Zersetzungsmechanismus+deflagrationsf%E2%80%9Ehiger+Substanzen.pdf SN - 978-3-00-048960-0 SP - 1 EP - 13 AN - OPUS4-33411 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Salg, Steffen A1 - Malow, Marcus A1 - Morhenn, H. ED - Pierucci, S. ED - Klemes, J.J. T1 - Investigations of deflagration in a four-litre-autoclave under atmospheric and non-atmospheric conditons N2 - A four-litre-autoclave was used to perform deflagration tests in a closed vessel. The aim was to investigate the suitability of this autoclave and to evaluate different parameters influencing the deflagration. The validation of test results showed that the autoclave is suited for the performance of deflagration tests. In comparison to tests performed in an open system according to VDI 2263-1 the results are in good agreement. In the closed vessel same characteristics as in the open test were determined. In addition, pressure rise and rate of pressure rise have been determined and used to characterise deflagrations. The influence of sample weight, tube diameter, bulk density, initial pressure and temperature was investigated. Furthermore, the emerging gas amount and the rate of gas evolution were determined and compared with pressure curves. The use of a four-litre-autoclave for performing deflagration tests offers several advantages in comparison to an open test. T2 - ICheaP12 - International conference on chemical & process engineering CY - Milan, Italy DA - 19.05.2015 KW - Deflagration KW - Closed vessel KW - Autoclave KW - Reduced pressure PY - 2015 UR - http://www.aidic.it/cet/15/43/344.pdf SN - 978-88-95608-34-1 DO - https://doi.org/10.3303/CET1543344 SN - 2283-9216 N1 - Serientitel: Chemical engineering transactions (CEt) – Series title: Chemical engineering transactions (CEt) VL - 43 SP - 2059 EP - 2064 AN - OPUS4-33414 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -