TY - JOUR A1 - Neumann, Patrick P. A1 - Bartholmai, Matthias T1 - Real-time wind estimation on a micro unmanned aerial vehicle using its inertial measurement unit N2 - This paper presents an approach for a quadrocoper-based micro unmanned aerial vehicle (UAV) that estimates the wind vector (speed and direction) in real-time based on measurement data of its on-board sensors only. This method does not need any additional airspeed sensor or dedicated anemometer, and thus the micro UAV's valuable payload remains free for other sensors. Wind tunnel and field tests were used to evaluate the performance of the approach. In order to quantify its accuracy, experiments are presented where data was collected with an anemometer placed in an open field with the micro UAV in flight following a predefined trajectory around the anemometer and hovering at a defined position close to it. KW - Micro unmanned aerial vehicle (UAV) KW - Quadrocopter KW - Real-time KW - Inertial measurement unit (IMU) KW - Airspeed calibration KW - Wind estimation (speed and direction) PY - 2015 DO - https://doi.org/10.1016/j.sna.2015.09.036 SN - 0924-4247 VL - 235 SP - 300 EP - 310 PB - Elsevier Science CY - Amsterdam [u.a.] AN - OPUS4-34737 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Natsopoulou, M.E. A1 - McMahon, Dino Peter A1 - Paxton, R.J. T1 - Parasites modulate within-colony activity and accelerate the temporal polyethism schedule of a social insect, the honey bee N2 - Task allocation in social insect colonies is generally organised into an age-related division of labour, termed the temporal polyethism schedule, which may in part have evolved to reduce infection of the colony's brood by pests and pathogens. The temporal polyethism schedule is sensitive to colony perturbations that may lead to adaptive changes in task allocation, maintaining colony homeostasis. Though social insects can be infected by a range of parasites, little is known of how these parasites impact within-colony behaviour and the temporal polyethism schedule. We use honey bees (Apis mellifera) experimentally infected by two of their emerging pathogens, Deformed wing virus (DWV), which is relatively understudied concerning its behavioural impact on its host, and the exotic microsporidian Nosema ceranae. We examined parasite effects on host temporal polyethism and patterns of activity within the colony. We found that pathogens accelerated the temporal polyethism schedule, but without reducing host behavioural repertoire. Infected hosts exhibited increased hyperactivity, allocating more time to self-grooming and foraging-related tasks. The strength of behavioural alterations we observed was found to be pathogen specific; behavioural modifications were more pronounced in virus-treated hosts versus N. ceranae-treated hosts, with potential benefits for the colony in terms of reducing within-colony transmission. Investigating the effects of multiple pathogens on behavioural patterns of social insects could play a crucial role in understanding pathogen spread within a colony and their effects on colony social organisation. KW - Host KW - Pathogen KW - Multiple infection KW - Apis mellifera KW - Nosema ceranae KW - Deformed wing virus PY - 2016 DO - https://doi.org/10.1007/s00265-015-2019-5 SN - 0340-5443 SN - 1432-0762 VL - 70 IS - 7 SP - 1019 EP - 1031 PB - Springer CY - Berlin ; Heidelberg [u.a.] AN - OPUS4-34738 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Bäßler, Ralph A1 - Keserovic, Amela A1 - Sobetzki, Joana A1 - Sarmiento Klapper, Helmuth T1 - Materials evaluation for geothermal applications N2 - In order to provide basic information on corrosion resistance to the designers and users of geothermal plants different metallic materials including duplex and austenitic stainless steels as well as a nickel alloy have been evaluated in artificial geothermal fluids simulating the conditions in some locations with geothermal potential in Germany as well as two sites in Indonesia. By electrochemical and long-term exposure tests at 100 °C and 150 °C the suitability of low alloyed steel UNS G41300, stainless steels UNS S31603 UNS S31803, UNS S32760, super austenitic steel UNS N08031 and nickel based alloy UNS N06059 was investigated in these geothermal fluids, using critical potentials and corrosion rates. In high-saline environments the crevice corrosion turned out to be the determining mechanism. The nickel based alloy shows excellent corrosion resistance against pitting corrosion. Excluding its high cost, it is very good to be used in the construction of geothermal facilities having highly saline brines. Stainless and duplex steels exhibit a limited corrosion resistance concerning pitting and crevice corrosion. Therefore they are not suitable for highly saline brines. The super austenite UNS N08031 showed a temperature depending behavior. In non-saline environments the low-alloyed steel UNS G41300 (beside of the higher alloyed materials) could be employed as a constructional material for the geothermal power plant, as long as a sufficient wall thickness of the material is considered. KW - Geothermal KW - Corrosion KW - Crevice corrosion KW - Suitability PY - 2015 UR - http://www.jurnalteknologi.utm.my/index.php/jurnalteknologi/article/view/5164 SN - 2180-3722 VL - 75 IS - 7 SP - 7 EP - 14 PB - Penerbit UTM Press CY - Johor Bahru AN - OPUS4-34747 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Seuthe, T. A1 - Grehn, M. A1 - Mermillod-Blondin, A. A1 - Bonse, Jörn A1 - Eberstein, M. T1 - Requirements on glasses for femtosecond-laser based micro-structuring N2 - In this work, glasses with systematically varied compositions were manufactured and irradiated by single Ti:sapphire fs-laserpulses (800 nm, 120 fs), focused at the surface and into the bulk of the glass materials. The samples were tested for their ablation threshold fluence as well as for structural changes using µ-Raman-spectroscopy. Correlations between the glass composition, the material-ablation on the glass surface and the permanent changes of the refractive index inside the glass volume after the irradiation by fs-laser pulses were obtained. The results show, that the structural modifications found at the surface of the glasses and inside its volume are closely related. However, while the ablation threshold fluence of the glass surface primarily depends on the glass dissociation energy, the permanent refractive index change inside the volume is rather determined by its ability for absorbing the fs-laser pulses and the subsequent relaxation processes. The results of this work provide some guidance on how the glass composition can be varied in order to optimize the fs-laser induced modification of dielectrics. T2 - 11th International Conference on Ceramic Interconnect & Ceramic Microsystems Technologies CY - Dresden, Germany DA - 20.04.2015 PY - 2015 SN - 978-1-5108-0456-2 DO - https://doi.org/10.4071/CICMT-TA24 SP - 47 EP - 53 PB - Curran CY - Red Hook, NY, USA AN - OPUS4-34755 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Rauchegger, C. A1 - Bayley, S. A1 - Schröder, Volkmar A1 - Thévenin, D. T1 - Dispersion of heavy gases - experimental results and numerical simulations N2 - The hazardous potential of accidental heavy gas releases, especially those involving flammable and toxic gases, is widely known. In order to predict the area in which these gases are in hazardous concentrations, an estimation of the dispersion of these gases must be carried out. While the hazardous area for flammable heavy gases is determined by the lower flammability limit (ca. >1 vol%), the release of toxic heavy gases can result in a much larger hazardous area. Toxic gases, even in very low concentrations (ca. <3,000 ppm), have the potential to be highly damaging. State-of-the-art dispersion models, such as the VDI Guideline 3783, can be used to estimate the dispersion of heavy gases. However, VDI 3783 gives no method for the prediction of the height and width of a heavy gas cloud, which are both required for quantitative risk analysis as well as for a possible coupling of a Lagrangian particle model with the VDI 3783 heavy gas dispersion model. Therefore, further calculation methods were used to describe these dimensions and were evaluated against experimental studies of the length, width, and height of the heavy and neutral gas field. In addition to that the influence of the source height on the heavy gas dispersion was also examined KW - Process safety KW - Heavy gas KW - Numerical simulation KW - Explosion protection PY - 2015 DO - https://doi.org/10.1002/prs.11723 SN - 1066-8527 SN - 1547-5913 SN - 0278-4513 VL - 34 IS - 3 SP - 280 EP - 285 PB - Wiley InterScience CY - Hoboken, NJ AN - OPUS4-34756 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Simon, Franz-Georg A1 - Holm, Olaf ED - Ludwig, C. ED - Matasci, C. ED - Edelmann, X. T1 - Recovery of metals from waste, an example for the resource cycle N2 - Bottom ash from municipal solid waste incineration (MSWI) consists of eiemental metals in considerable amounts. The fine fraction < 4 mm additionally contains chemically bound metals (oxides, carbonates, Silicates). Separation prospects with techniques as in ore processing (flotation, density separation, bioleaching, hydrothermal solution) are discussed. During alteration after wet extraction mineral material with hydraulic properties form coatings on almost all particles of the bottom ash and complicate separation procedures. ln addition bottom ash from MSWI is a heterogeneaus material. For sufficient enrichment different concerted treatment steps seemed to be essential associated with an uncertainty of economic viability. The utilisation of metal compounds present in bottom ash as secondary raw material depends on the energy- and resource-efficiency of the enrichment processes. Therefore energy and material flow considerations are presented. KW - Recyclable material KW - Recycling technology KW - Waste management PY - 2015 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-347572 UR - http://infoscience.epfl.ch/record/213010 SN - 978-3-9521409-6-3 SP - 289 EP - 293 AN - OPUS4-34757 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Schmidt, Benita A1 - Pergantis, S. A. A1 - Esteban-Fernández, Diego A1 - Jakubowski, Norbert A1 - Günther, D. T1 - Investigation of a combined microdroplet generator and pneumatic nebulization system for rapid quantitative determination of metal-containing nanoparticles using ICP-MS N2 - In this work, a routinely applicable approach is presented to characterize metal NPs. Individual droplets generated from a microdroplet generator (MDG) were merged into an aerosol generated by a pneumatic nebulizer (PN) and introduced into an ICPMS. The MDG offers high transport efficiency of individual and discrete droplets and was therefore used to establish a calibration function for mass quantification of NPs which were introduced through the PN following the single particle procedure as described elsewhere. The major advantages of such a combined configuration include fast processing of large sample volumes, fast exchanges of different sample matrixes, and the calibration of the NP signal using traceable elemental standards, thus avoiding the need to use NP reference materials or other, not always thoroughly characterized, commercially available NPs. The transport efficiency of the sample introduction is calculated based on the fact that 100% of the calibrant reaches the plasma through the MDG, whereas for the PN a NP suspension containing a known number concentration is used. Alternatively, bulk analysis of the NP material allows transport efficiency determination without any additional information from reference NPs. With this method, we could determine the size of standard silver NPs at 60.4 ± 1.0 nm and 80.0 ± 1.4 nm, respectively, which agrees with the size ranges given by the supplier (60.8 ± 6.6 nm and 79.8 ± 5.4 nm). Furthermore, we were also able to determine the NPs number concentration of the sample (Ag/Au) with a deviation of 3.2% the expected value. KW - Nanoparticles KW - ICP-MS KW - Microdroplet generator PY - 2015 DO - https://doi.org/10.1021/acs.analchem.5b01604 SN - 0003-2700 SN - 1520-6882 VL - 87 IS - 17 SP - 8687 EP - 8694 PB - American Chemical Society CY - Washington, DC AN - OPUS4-34803 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - BOOK A1 - Czichos, Horst T1 - Was ist falsch am falschen Rembrandt? und wie hart ist Damaszener Stahl? Wie man Technik Kunst erforscht, prüft und erhält PY - 2002 SN - 3-87584-205-7 SP - 1 EP - 191 PB - Nicolaische Verlagsbuchhandlung GmbH CY - Berlin AN - OPUS4-34786 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Aichner, Bernhard A1 - Bussian, B. A1 - Lehnik-Habrink, Petra A1 - Hein, Sebastian T1 - Regionalized concentrations and fingerprints of polycyclic aromatic hydrocarbons (PAHs) in german forest soils N2 - Samples of 474 forest stands in Germany were analysed for concentrations of polycyclic aromatic hydrocarbons (PAHs) in three sampling depths. Enhanced concentrations were mainly found at spots relatively close to densely industrialized and urbanized regions and at some topographically elevated areas. Average enrichment factors between mineral soil and humic layer depend on humus type i.e. decrease from mull via moder to mor. Based on their compound-patterns, the observed samples could be assigned to three main clusters. For some parts of our study area a uniform assignment of samples to clusters over larger regions could be identified. For instance, samples taken at vicinity to brown-coal strip-mining districts are characterized by high relative abundances of low-molecular-weight PAHs. These results suggest that PAHs are more likely originated from local and regional emitters rather than from long-range transport and that specific source-regions can be identified based on PAH fingerprints. KW - Organic pollutants KW - PAHs KW - Soil KW - Emissions KW - Long-range transport KW - Enrichment factor KW - Humic layer KW - Mineral soils KW - O-horizon PY - 2015 DO - https://doi.org/10.1016/j.envpol.2015.03.026 SN - 0269-7491 SN - 0013-9327 SN - 1873-6424 VL - 203 SP - 31 EP - 39 PB - Elsevier Ltd. CY - New York, NY [u.a.] AN - OPUS4-34792 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Köppen, Robert T1 - Book review: Advanced mass spectrometry for food safety and quality N2 - Advanced Mass Spectrometry for Food Safety and Quality provides information on recent advancements made in mass spectrometry-based techniques and their applications in food safety and quality, also covering the major challenges associated with implementing these technologies for more effective identification of unknown compounds, food profiling, or candidate biomarker discovery. Recent advances in mass spectrometry technologies have uncovered tremendous opportunities for a range of food-related applications. However, the distinctive characteristics of food, such as the wide range of the different components and their extreme complexity present enormous challenges. This text brings together the most recent data on the topic, providing an important resource towards greater food safety and quality. • Presents critical applications for a sustainable, affordable and safe food supply • Covers emerging problems in food safety and quality with many specific examples. • Encompasses the characteristics, advantages, and limitations of mass spectrometry, and the current strategies in method development and validation • Provides the most recent data on the important topic of food safety and quality PY - 2015 DO - https://doi.org/10.1007/s00216-015-9060-0 SN - 1618-2642 SN - 1618-2650 VL - 407 IS - 28 SP - 8383 EP - 8384 PB - Springer CY - Berlin AN - OPUS4-34818 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Salg, Steffen A1 - Malow, Marcus A1 - Michael-Schulz, Heike T1 - Wie beeinflussen nicht-atmosphärische Bedingungen das Deflagrationsverhalten? N2 - Zur Bestimmung der Deflagrationsfähigkeit von energiereichen Stoffen/ Gemischen wurde zuletzt ein Vier-Liter-Autoklav vorgeschlagen, der im Vergleich zu den derzeit gängigen Prüfmethoden eine Reihe von Vorteilen bietet. In diesem Beitrag wird der Frage nachgegangen, wie nicht-atmosphärische Bedingungen das Deflagrationsverhalten beeinflussen. Zur Beantwortung dieser Frage wurden weitere Experimente im genannten Autoklaven und in einem kleineren Autoklaven durchgeführt. Im Wesentlichen lässt sich feststellen, dass der Druck im Probengefäß vor Versuchsbeginn, insbesondere reduzierter Ausgangsdruck < 1 bar Auswirkungen auf das Deflagrationsverhalten hat. Das Vorhandensein einer reinen Stickstoffatmosphäre hingegen, beeinflusst das Deflagrationsverhalten nicht. T2 - 12. Fachtagung Anlagen-, Arbeits- und Umweltsicherheit CY - Köthen, Germany DA - 05.11.2015 KW - Deflagration KW - Geschlossener Behälter KW - Autoklav KW - Nicht-atmosphärische Bedingungen PY - 2015 SN - 978-3-86011-091-1 SP - P12, 1 EP - 4 AN - OPUS4-34821 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - RPRT A1 - Brosig, Laura A1 - Horn, Wolfgang A1 - Pyza, Lars A1 - Jann, Oliver T1 - Ringversuch zur Einführung der Geruchsmessungen nach DIN ISO 16000-28 in die Bewertung von Bauprodukten N2 - Während in der Vergangenheit insbesondere die Entwicklung einer sensorischen Prüfmethode (in DIN ISO 16000-28 und VDI 4302-1 genormt und im AgBB-Schema verankert) für die Bewertung von Bauprodukten im Vordergrund der Betrachtungen stand, wurde im Rahmen der vom UBA initiierten Pilotphase mithilfe des Ringversuches erstmals die institutsübergreifende Anwendbarkeit dieser Verfahren untersucht. Ziel dabei war es, noch bestehende Schwierigkeiten im Umgang mit der Prüfmethode zu identifizieren und Empfehlungen für das weitere Vorgehen herauszuarbeiten. KW - Geruchsmessung KW - Empfundene Intensität KW - Hedonik KW - VOC KW - Bauprodukt PY - 2015 UR - http://www.umweltbundesamt.de/publikationen/ringversuch-zur-einfuehrung-der-geruchsmessungen SN - 1862-4804 VL - 88/2014 SP - UBA-FB 002049, EP - 1-141 CY - Dessau-Roßlau AN - OPUS4-34885 LA - deu 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 - 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 - 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 - 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 - 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 - 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 - CONF A1 - Knechtel, Sophie A1 - Schmidt, Simon A1 - Mishra, K. B. A1 - Wehrstedt, Klaus-Dieter T1 - Modellierung der Hauptbrandszenarien von flüssigem Wasserstoff (LH2) mittels CFD N2 - Die sichere Lagerung und der Transport von Flüssigwasserstoff (LH2) verlangen nach verlässlichen Abschätzungen möglicher Risiken durch Feuer oder Explosion. Aufgrund des breiten Explosionsbereichs (4 Vol.-% - 74 Vol.-%) reagiert Wasserstoff sehr schnell und produziert hohe Flammentemperaturen. Da Wasserstoffflammen ruß- bzw. farblos sind, ist Wärmestrahlung im Fernfeld kein Risikofaktor. Allerdings stellen die hohe lokale Wärmestrahlung und die nicht sichtbaren Flammen eine Gefahr für Menschen und Infrastruktur in der Nähe dar. Es ist daher notwendig die Gefahren von LH2-Feuern sorgfältig zu bewerten. Einerseits sind experimentelle Untersuchungen verschiedener Szenarien teuer, andererseits können sie teilweise auch praktisch nicht durchführbar sein. Numerische Simulationen dieser Szenarien können ein Ausweg aus diesem Problem sein. In der vorliegenden Arbeit wird ein solcher Ansatz genutzt, um große Brandszenarien mit LH2 mittels CFD (Computational Fluid Dynamics) zu modellieren und so die notwendigen Sicherheitsabstände abzuschätzen. Der Fokus liegt dabei auf der Simulation von Jet- und Pool-Feuerszenarien mit einem kommerziellen CFD-Code (Ansys CFX). Die benötigten geometrischen Modelle werden für Jet- und Pool-Feuer erstellt und mit den nötigen Randbedingungen implementiert. Wichtige Submodelle für chemische Reaktionen (Einschritt- und detaillierte Modelle), Verbrennung (Eddy-Dissipation- und Flamelet-Modell) und Strahlung (Discrete-Transfer-Modell) werden genutzt. Die maximal simulierten Flammentemperaturen liegen bei ~2100 K für Jet-Feuer und ~2300 K für Pool-Feuer. Um Aussagen zu thermischen Sicherheitsabständen zu treffen, wurden die Spezifischen Ausstrahlungen (SEP) ermittelt und anschließend entsprechende Positionsfaktoren gewählt, um verlässliche Sicherheitsabstände zu berechnen. Je nach Bedarf können CFD-Modelle sowohl für qualitative als auch für quantitative Risikobewertungen von LH2-Großbränden genutzt werden. T2 - 12. Fachtagung Anlagen-, Arbeits- und Umweltsicherheit CY - Köthen, Germany DA - 05.11.2015 KW - Flüssigwasserstoff KW - Großbrand KW - Poolfeuer KW - Jet-Feuer KW - CFD KW - Sicherheitsabstand PY - 2015 SN - 978-3-86011-091-1 SP - Paper P-11, 1 EP - 8 AN - OPUS4-34827 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Mehdianpour, Milad A1 - Waßmuth, Carl-Friedrich T1 - Minimalinvasive Materialuntersuchungen an seilabgespannten Rohrmasten zur Bauwerkserhaltung T1 - Minimally invasive material tests on guyed tubular masts N2 - Abgespannte Stahlrohrmaste zur Rundfunkübertragung wurden in den 1950er- und 60er-Jahren häufig mit Paralleldrahtbündeln errichtet. Diese Seile werden seit geraumer Zeit wegen Korrosionsschäden sukzessive gegen vollverschlossene Spiralseile ausgetauscht. Infolge der damit einhergehenden Veränderung der Steifigkeiten ist mit dem Austausch oft eine Neuberechnung erforderlich. Unter Berücksichtigung der aktuellen Normen können nicht immer alle Nachweise erfüllt werden, selbst wenn das Bauwerk weitgehend noch intakt erscheint. Rohrschaftsanierungen sind extrem aufwändig und können den wirtschaftlichen Totalschaden darstellen, d. h., dem Bauwerk droht Abriss und Neubau. Für die Sanierung des 231 m hohen abgespannten Stahlrohrmastes am Standort Berlin Scholzplatz wurden minimalinvasive Materialuntersuchungen vorgenommen, basierend auf In-situ- und Labortests. In den statistischen Auswertungen konnte belegt werden, dass gegenüber den Angaben der Bauwerksdokumentation höhere Festigkeiten vorlagen. Durch präzise Lastannahmen und für das Bauwerk optimierte Seilvorspannungen konnten aufwändige Verstärkungsmaßnahmen des Rohrschaftes vermieden werden. KW - Bauwerkserhaltung KW - Mast, abgespannter KW - Rohrmast KW - Antennenträger aus Stahl KW - Seile KW - Materialuntersuchung KW - Härtemessung KW - Zugversuch KW - Brinellhärte/Zugfestigkeit KW - Zugfestigkeit/Streckgrenze PY - 2016 UR - http://dx.doi.org/10.1002/bate.201500094 DO - https://doi.org/10.1002/bate.201500094 SN - 1437-0999 VL - 93 IS - 1 SP - 8 EP - 13 PB - Ernst & Sohn Verlag für Architektur und technische Wissenschaften GmbH & Co. KG CY - Berlin AN - OPUS4-35522 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Myrach, Philipp A1 - Maierhofer, Christiane A1 - Rahammer, M. A1 - Kreutzbruck, Marc T1 - Parameters in lock-in thermography of CFRP laminates N2 - Active thermography with lock-in excitation is a non-destructive testing method that is also feasible for testing of carbon fiber reinforced polymers (CFRP). For validating the method extensive investigations were done during a research project in order to advance a standardization process. The most important parameters of optical and ultrasonic excitation thermography were investigated. For example, the appropriate selection of spectral sensitivity of the used infrared camera systems is important for recording undisturbed thermal signals. Regarding excitation, influences of excitation power and ultrasonic frequency were studied. Furthermore, material parameters such as CFRP layup are known for strongly affecting the results of measurement. KW - Standardisierung KW - Lock-in thermography KW - Lock-in Thermografie KW - CFRP KW - CFK KW - optical excitation KW - ultrasonic excitation KW - Ultraschall KW - standardization PY - 2016 DO - https://doi.org/10.3139/120.110814 SN - 0025-5300 VL - 58 IS - 1 SP - 31 EP - 35 PB - Carl Hanser Verlag CY - München AN - OPUS4-35479 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Jonietz, Florian A1 - Myrach, Philipp A1 - Suwala, H. A1 - Ziegler, Mathias T1 - Examination of Spot Welded Joints with Active Thermography N2 - The method described here allows to determine the size of the thermal contact between two metal sheets joined by spot welding. This size is a measure for the size of the weld nugget, i.e. the zone melted during the welding process, and thus the quality of the welded joint. The method applies active thermography in transmission or reflection setup. Especially the reflection setup offers an attractive possibility for non-destructive testing when components can be accessed from one side only. The spot weld region is optically heated by laser or flash light radiation. The weld nugget provides the mechanical joint, but also constitutes a thermal bridge between the two welded sheets. The latter will be exploited in this method. The better thermal contact at the weld Nugget contrasts with the surrounding material, where the heat transfer between the two sheets is comparatively low. A major advantage of the described method is the applicability on sheets without any surface treatment. This is achieved by a proper normalization of the data, allowing for a correction of the varying surface emissivity. KW - Active thermography KW - Spot weld KW - Automotive industry PY - 2016 UR - http://link.springer.com/article/10.1007/s10921-015-0318-4?wt_mc=internal.event.1.SEM.ArticleAuthorIncrementalIssue DO - https://doi.org/10.1007/s10921-015-0318-4 VL - 35:1 SP - 1 EP - 14 PB - Springer CY - New York AN - OPUS4-35480 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Falkenberg, Rainer T1 - Simulation von Rißwachstum durch ein thermodynamisch konsistentes Phasenfeldmodell N2 - Durch ein thermodynamisch konsistentes Phasenfeldmodell kann die Rißinitiierung sowie das Rißwachstum in einem spröden Material mit Hilfe der Finite-Elemente-Methode simuliert werden. Ein diskreter scharfer Riß wird durch einen Regularisierungsansatz in ein Phasenfeld überführt, das einen kontinuierlichen Übergang zwischen Riß und Restmaterial abbildet. Modelle von C(T) - Bruchmechanikproben konnten unter monoton wachsender Belastung simuliert werden. Die Ergebnisse konnten mit analytischen Ergebnissen der linear-elastischen Bruchmechanik verglichen werden. Ablenkungen des Rißpfades konnten durch Modelle von gelochten Proben simuliert werden. An dem Modell eines Dreipunktbiegeversuchs konnte die Rißinitiierung demonstriert werden. Die Kenntnis und Modellierung eines vordefinierten Rißpfades ist bei Verwendung dieses Modells nicht erforderlich, was insbesondere zur Untersuchung von komplexen Rißpfaden von Vorteil sein kann. N2 - Crack initiation and propagation in a brittle material is modeled in the finite-element-framework by an extended thermodynamical phase field formulation. The sharp crack discontinuity is transferred into a degradation phase field by a regularisation that ensures a continous transition between crack and residual material. The model of a C(T)-specimen under monotonic increasing load was simulated. The results were compared with analytical results of linear-elastic fracture mechanics. Crack kinking was simulated on a specimen with holes. Crack initiation was studied one a model of a three-point bending specimen. The knowledge and modeling of a predefined crack path is not required with the application of this model and provides the ability to calculate complex crack topologies. T2 - 48. Tagung des DVM-Arbeitskreises Bruchmechanik und Bauteilsicherheit, Bruchmechanische Werkstoff- und Bauteilbewertung: Beanspruchungsanalyse, Prüfmethoden und Anwendungen CY - Freiburg im Breisgau; Germany DA - 16.02.2016 KW - Finite-Elemente-Methode KW - finite-element-method KW - Rißwachstum KW - Rißinitiierung KW - Phasenfeldmodell KW - Crack growth KW - crack initiation KW - phase field model PY - 2016 SN - 2366-4797 VL - DVM Bericht 248 SP - 41 EP - 50 CY - Berlin AN - OPUS4-35483 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Holm, Olaf A1 - Rein, A. A1 - Trapp, S. A1 - Popp-Hoffmann, S. A1 - Bittens, M. A1 - Leven, C. A1 - Dietrich, P. T1 - Comparison of phytoscreening and direct-push-based site investigation at a rural megasite contaminated with chlorinated ethenes N2 - The reliable characterization of subsurface contamination of spatially extended contaminated sites is a challenging task, especially with an unknown history of land use. Conventional technologies often fail due to temporal and financial constraints and thus hinder the redevelopment of abandoned areas in particular. Here we compare two site screening techniques that can be applied quickly at relatively low cost, namely Direct Push (DP)-based groundwater sampling and tree core sampling. The effectiveness of both methods is compared for a rural megasite contaminated with chlorinated hydrocarbons. Unexpected pollution hot spots could be identified using both of these methods, while tree coring even enabled the delineation of the contaminant plume flowing into an adjacent wetland inaccessible for DP units. Both methods showed a good agreement in revealing the spatial pattern of the contamination. The correlation between groundwater concentrations and equivalent concentrations in wood was linear and highly significant for trichloroethene. Correlation was less obvious for its metabolite cis-dichloroethene, but still significant. As outcome of our study we recommend tree coring and for initial screening in combination with a DP sampling to retrieve quantitative data on groundwater pollutants in order to assess the contamination situation of a non- or only partly investigated site. The subsequent placement of monitoring wells for long-term monitoring of contamination levels is recommended. A combination of methods would achieve more relevant information at comparable or possibly even lower efforts in comparison to a conventional site investigation. KW - non-invasive investigation KW - phytoscreening KW - direct-push KW - screening KW - trichloroethene KW - trichloroethylene KW - groundwater contamination KW - tree core sampling PY - 2015 UR - http://onlinelibrary.wiley.com/doi/10.1111/gwmr.12122/abstract DO - https://doi.org/10.1111/gwmr.12122 SN - 1745-6592 VL - 35 IS - 4 SP - 45 EP - 56 PB - Wiley Online Library AN - OPUS4-35595 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Dmitriev, A. I. A1 - Häusler, Ines A1 - Wetzel, B. A1 - Zhang, G. A1 - Österle, Werner T1 - Modeling of the stress-strain behavior of an epoxy-based nanocomposite filled with silica nanoparticles N2 - The method of movable cellular automata (MCA) was applied to simulate the stress-strain behavior of a nano composite consisting of an epoxy matrix and 6 vol. % silica nano particles. The size of the elements used for modelling was fixed at 10 nm, corresponding approximately to the diameter of the filler particles. Since not only the stress-strain response of the two constituents but also debonding of neighboring particles and granular flow was taken into account, plastic deformation as well as crack initiation and propagation could be simulated with the model. Modelling results were compared with tensile test results of both, pure epoxy as well as the epoxy-6 vol. % SiO2 composite. Since assuming bulk properties of the two constituents did not yield satisfactory results, slight modifications of the nanoparticle response functions and nanostructures were tested numerically. Finally, it was observed that only the assumption of slightly increased strength properties of the epoxy yielded good correlation between experimental and modelling results. This was attributed to an increased cross linking of the epoxy caused by the presence of silica nano particles. KW - Nanocomposite KW - Polymer matrix composite KW - Stress-strain behavior KW - Modeling KW - Computational mechanics PY - 2016 DO - https://doi.org/http://dx.doi.org/10.1016/j.matdes.2015.10.038 SN - 0264-1275 VL - 89 SP - 950 EP - 956 PB - Elsevier AN - OPUS4-35596 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Österle, Werner A1 - Dmitriev, A. I. A1 - Wetzel, B. A1 - Zhang, G. A1 - Häusler, Ines A1 - Jim, B.C. T1 - The role of carbon fibers and silica nanoparticles on friction and wear reduction of an advanced polymer matrix composite N2 - Excellent tribological properties of an advanced polymer matrix composite were obtained by a combination of micro- and nano-sized fillers. Surface features and the nanostructure of tribofilms were characterized by advanced microscopic techniques, and correlated with the macroscopic behavior in terms of wear rate and friction evolution. A model based on movable cellular automata was applied for obtaining a better understanding of the sliding behavior of the nanostructured tribofilms. The failure of the conventional composite without silica nanoparticles could be attributed to severe oxidational wear after degradation of an initially formed polymer transfer film. The hybrid composite preserves its antiwear and antifriction properties because flash temperatures at micron-sized carbon fibers, lead to polymer degradation and subsequent release of nanoparticles. It has been shown that the released particles are mixed with other wear products and form stable films at the disc surface thus preventing further severe oxidational wear. Furthermore, the released wear product also is embedding carbon fibers at the composite surface thus preventing fiber fragmentation and subsequent third body abrasion. With nanoscale modelling we were able to show that low friction and wear can be expected if the nanostructured silica films contain at least 10 vol.% of a soft ingredient. KW - Carbon fibers KW - Silica nanoparticles KW - Hybrid composite KW - Tribological properties KW - Tribofilm KW - Sliding simulation PY - 2016 DO - https://doi.org/10.1016/j.matdes.2015.12.175 SN - 0264-1275 VL - 93 SP - 474 EP - 484 PB - Elsevier AN - OPUS4-35598 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Ringleb, F. A1 - Eylers, K. A1 - Teubner, T. A1 - Boeck, T. A1 - Symietz, Christian A1 - Bonse, Jörn A1 - Andree, Stefan A1 - Krüger, Jörg A1 - Heidmann, B. A1 - Schmid, M. A1 - Lux-Steiner, M. T1 - Regularly arranged indium islands on glass/molybdenum substrates upon femtosecond laser and physical vapor deposition processing N2 - A bottom-up approach is presented for the production of arrays of indium islands on a molybdenum layer on glass, which can serve as micro-sized precursors for indium compounds such as copper-indium-gallium-diselenide used in photovoltaics. Femtosecond laser ablation of glass and a subsequent deposition of a molybdenum film or direct laser processing of the molybdenum film both allow the preferential nucleation and growth of indium islands at the predefined locations in a following indium-based physical vapor deposition (PVD) process. A proper choice of laser and deposition parameters ensures the controlled growth of indium islands exclusively at the laser ablated spots. Based on a statistical analysis, these results are compared to the non-structured molybdenum surface, leading to randomly grown indium islands after PVD. KW - Femtosecond laser KW - Physical vapor deposition KW - Indium KW - Molybdenum substrate KW - Microconcentrator solar cell PY - 2016 DO - https://doi.org/10.1063/1.4943794 SN - 0003-6951 VL - 108 IS - 11 SP - 111904-1 EP - 111904-4 AN - OPUS4-35602 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Barthel, Anne-Kathrin A1 - Wesch, Ch. A1 - Braun, Ulrike A1 - Klein, R. A1 - Paulus, M. T1 - No microplastics in benthic eelpout (Zoarces viviparus): An urgent need for spectroscopic analyses in microplastic detection N2 - Monitoring the ingestion of microplastics is challenging and suitable detection techniques are insufficiently used. Thus, misidentifying natural for synthetic microfibres cannot be avoided. As part of a framework to monitor the ingestion of microplastics in eelpout, this short report addresses the accurate identification of microfibres. We show that, following visual inspections, putatively synthetic microfibres are indeed of natural origin, as ascertained by spectrometric analyses. Consequently, we call for an inclusion of spectroscopic techniques in standardized microplastic monitoring schemes. KW - Monitoring KW - Ingestion KW - Misidentification KW - Microfibre KW - Spectroscopy PY - 2016 DO - https://doi.org/10.1016/j.envres.2016.03.017 SN - 0013-9351 VL - 148 SP - 36 EP - 38 PB - Elsevier AN - OPUS4-35603 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Lehmann, Jens A1 - Burkert, Andreas A1 - Mietz, Jürgen T1 - Investigations proofing the passive layer stability of stainless steels N2 - The presented investigations have proved the principal suitability of the KorroPad method to assess the passive layer stability of stainless steels. The electrochemical mode of action could be described in detail and limitations of the applicability have been demonstrated. The influence of different surface finishes has been investigated and verified by known methods for describing corrosion resistances. As a result, the increased corrosion susceptibility of two ground surfaces has been detected, but also the corrosion resistance of further surface finishes could be confirmed. KW - Stainless steel KW - KorroPad KW - Passive layer PY - 2016 DO - https://doi.org/10.1002/maco.201408202 VL - 1 IS - 67 SP - 84 EP - 91 PB - WILEY-VCH Verlag GmbH & Co. KGaA CY - Weinheim AN - OPUS4-35545 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Schmack, R. A1 - Eckhardt, B. A1 - Koch, G. A1 - Ortel, Erik A1 - Kraehnert, R. T1 - ZnO coatings with controlled pore size, crystallinity and electrical conductivity N2 - Zinc oxide is a wide bandgap semiconductor with unique optical, electrical and catalytic properties. Many of its practical applications rely on the materials pore structure, crystallinity and electrical conductivity. We report a synthesis method for ZnO films with ordered mesopore structure and tuneable crystallinity and electrical conductivity. The synthesis relies on dip-coating of solutions containing micelles of an amphiphilic block copolymer and complexes of Zn2+ ions with aliphatic ligands. A subsequent calcination at 400 °C removes the template and induces crystallization of the pore walls. The pore structure is controlled by the template polymer, whereas the aliphatic ligands control the crystallinity of the pore walls. Complexes with a higher thermal stability result in ZnO films with a higher content of residual carbon, smaller ZnO crystals and therefore lower electrical conductivity. The paper discusses the ability of different types of ligands to assist in the synthesis of mesoporous ZnO and relates the structure and thermal stability of the precursor complexes to the crystallinity and electrical conductivity of the zinc oxide. KW - conductivity KW - EISA KW - pore templating KW - pore size control KW - ligands KW - zinc oxide PY - 2016 DO - https://doi.org/10.5755/j01.ms.22.1.8634 SN - 1392–1320 VL - 22 IS - 1 SP - 74 EP - 81 PB - Kaunas University of Technology, Lithuania AN - OPUS4-35550 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - BOOK A1 - Hübert, Thomas A1 - Boon-Brett, L. A1 - Buttner, W. J. T1 - Sensors for Safety and Process Control in Hydrogen Technologies N2 - This book is on sensors which are regularly deployed in technologies and processes related to hydrogen production, storage, distribution, and use. Not all types of sensors are equally suitable for specific hydrogen applications. The information in this book is intended to help the reader understand the basics of sensors, sensing technologies, sensor applications, and to provide guidelines for choosing the right sensors and the use of them correctly. Correct deployment of appropriate sensors demands knowledge of the sensing principle and of the physical or chemical quantities being measured. Because of the properties of hydrogen, the potential for its vastly increased use in a future low-carbon economy and possible hazards associated with its use, special attention is paid to hydrogen sensors. This book will not focus on the details of the hydrogen technologies nor on the many safety-related aspects of these technologies. Many books are already available on these topics. Instead the detection principle of hydrogen sensors and other sensor types used, in the dynamic and rapidly developing field of hydrogen technologies, are treated in detail in this book. In the first chapter a brief overview is presented on basic hydrogen properties and particularly on those properties which are most relevant for safety and for sensing. To illustrate the extensive field of contemporary applications and the exciting possibilities for near future sensor applications, existing and emerging markets using large quantities of hydrogen are mentioned. The role of sensors as devices for monitoring and control of processes and as safety monitoring devices is outlined. The second chapter gives an introduction to sensing technology and provides the Reader with relevant information pertaining to sensor definitions and classification, sensor metrics, and performance arameters, in addition to background information on sensor preparation technologies and techniques. While there are many books available which provide more exhaustive information on each of these topics, e.g., the level of detail provided in this chapter is sufficient to appreciate the salient features of sensing and sensing Technology which are central to hydrogen safety and monitoring of relevant applications. Chapter 3 provides a comprehensive overview of emerging and commercially available hydrogen sensors, an explanation of their sensing principle, and important aspects of their performance. A comprehensive and up-to-date account of the theory (physical or chemical principles), design, and practical implementations of hydrogen sensors for use in hydrogen related applications is presented. Similar information on chemical sensors for other gases, such as oxygen and trace components, which are also highly important in hydrogen technologies because of potential hazards to human health, process safety or facility performance, is provided in Chapter 4. In Chapter 5 descriptions of physical sensors for temperature, pressure, gas flow, and fire indication, which are also germane for the safe use of hydrogen, are provided. Standards, codes, and regulatory documents, which provide practical advice and legislative requirements regarding sensor deployment and performance, are described in Chapter 6. This chapter also makes reference to the main procedures for sensor testing in gas Standards including precise analytical methods and reference methods. The chapter concludes with a discussion on sensor selection and some installation guidelines are provided. In Chapter 7 traditional and emerging processes and technologies involving hydrogen are described. The application of sensors in processes for the production of hydrogen, hydrogen storage, distribution, and the use of hydrogen in stationary and mobile fuel cells is discussed. Furthermore, the use of hydrogen as a coolant and chemical reagent (medium) in various processes is described. The exploitation of sensors for replacing traditional analytical instrumentation is also discussed. Finally supplementary information is provided on hydrogen properties, measuring quantities, and sensor parameters. KW - Hydrogen Technologies KW - Hydrogen Sensors KW - Gas Sensors, Safety KW - Process Control PY - 2016 SN - 978-1-4665-9654-2 SP - 1 EP - 414 PB - CRC Press Taylor & Francis Group CY - Boca Raton, Florida, USA AN - OPUS4-35507 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - RPRT A1 - Andrzejuk, W. A1 - Bau, A. A1 - Charoud-Got, J. A1 - de Vos, P. A1 - Emteborg, H. A1 - Lamberty, A. A1 - Linsinger, T. A1 - Oostra, A. A1 - Quetel, C. A1 - Roebben, G. A1 - Tresl, I. A1 - Hearn, R. A1 - Wood, S. A1 - Pritzkow, W. A1 - Vogl, Jochen T1 - Certification of the sulfur mass fraction in three commercial petrol materials - Certified reference materials ERM-EF211, ERM-EF212 and ERM-EF213 N2 - Three petrol reference materials were certified for their total sulfur content in support of Directive 2003/17/EC of the European Parliament and of the European Council, which stipulates that petrol with a maximum S content of 10 mg/kg must be available in all member states by 2009. Commercially available petrol was obtained and filled into borosilicate ampoules without further treatment. Homogeneity of the materials was tested and no heterogeneity was detected for two of the materials, whereas minor heterogeneity was observed for the third material. Stability of the materials was tested for 8-12 months at 60 °C and no degradation was observed. Characterisation was based on isotope-dilution mass spectrometry (IDMS) applied as primary method of measurement by three European metrology institutes and certified values were assigned using all results. The certified uncertainties include contributions of (potential) heterogeneity, potential degradation as well as characterisation. The final assigned values are: ERM-EF211: 48.8 ± 1.7 mg/kg ERM-EF212: 20.2 ± 1.1 mg/kg ERM-EF213: 9.1 ± 0.8 mg/kg The materials are available from IRMM (ERM-EF211), LGC (ERM-EF212) and BAM (ERMEF213) KW - Sulfur KW - Petrol KW - IDMS PY - 2007 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-355804 SN - 978-92-79-05370-2 SN - 1018-5593 SP - 1 EP - 37 PB - European Communities CY - Luxembourg AN - OPUS4-35580 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Feller, Viktor A1 - Orglmeister, R. A1 - Mielentz, Frank T1 - Entmischung von Quellsignalen aus mehrkanaligen Ultraschallmessungen an Beton N2 - Dieser Beitrag stellt die aktuellen Fortschritte der Ultraschallprüfung von Betonbauteilen basierend auf dem ICA-Verfahren vor. Das eingesetzte Verfahren wird bereits erfolgreich in anderen Bereichen der Ultraschallprüfung angewendet. Das große Potential dieser Methode liegt in der Möglichkeit, die sich überlagernden Reflexionen der Ultraschallsignale durch nur wenige Messungen in Echtzeit voneinander zu trennen und durch einfache Triangulation zu lokalisieren. Es wurden Experimente hinsichtlich der Eignung und praktischer Relevanz des JADE-Algorithmus durchgeführt. Die Untersuchungen erfolgten sowohl an Polyamid als auch an Betontestkörpern. Die Leistungsfähigkeit des JADE-Algorithmus bezüglich der Quellsignaltrennung wird anhand von mehrkanaligen Ultraschallmessungen gezeigt. Die extrahierten Komponenten enthalten Signalanteile, die mit den entsprechenden Echosignalen in der Messung korrelieren. Zukünftig wird das untersuchte Verfahren mit der Gruppenstrahlertechnik und einem geeigneten Sende-Empfangskonzept kombiniert, um so die Aussagesicherheit der zerstörungsfreien Untersuchungen zu erhöhen. KW - Blinde Quellentrennung KW - Unabhängigkeitsanalyse KW - JADE-Algorithmus KW - Ultraschall KW - Blind source separation (BSS) KW - Independent component analysis (ICA) KW - JADE algorithm KW - Ultrasound PY - 2015 DO - https://doi.org/10.1515/teme-2014-0045 SN - 0340-837X SN - 0178-2312 SN - 0171-8096 VL - 82 IS - 9 SP - 432 EP - 439 PB - Oldenbourg CY - München AN - OPUS4-34331 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Abali, B. E. A1 - Wu, Cheng-Chieh A1 - Müller, W.H. T1 - An energy-based method to determine material constants in nonlinear rheology with applications N2 - Many polymer-type materials show a rate-dependent and nonlinear rheological behavior. Such a response may be modeled by using a series of spring-dashpot systems. However, in order to cover different time scales the number of systems may become unreasonably large. A more appropriate treatment based on continuum mechanics will be presented herein. This approach uses representation theorems for deriving material equations and allows for a systematic increase in modeling complexity. Moreover, we propose an approach based on energy to determine thematerial parameters.This method results in a simple linear regression problemeven for highly nonlinearmaterial equations. Therefore, the inverse problem leads to a unique solution. The significance of the proposed method is that the stored and dissipated energies necessary for the procedure are measurable quantities. We apply the proposed method to a 'semi-solid' material and measure its material parameters by using a simple-shear rheometer. KW - Material equations KW - Constitutive relations KW - Nonlinear rheology KW - Simple-shear rheometer KW - Inverse analysis PY - 2016 DO - https://doi.org/10.1007/s00161-015-0472-z SN - 0935-1175 SN - 1432-0959 VL - 28 IS - 5 SP - 1221 EP - 1246 PB - Springer CY - Berlin AN - OPUS4-34333 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Schneider, Ronald A1 - Fischer, J. A1 - Bügler, M. A1 - Nowak, M. A1 - Thöns, S. A1 - Borrmann, A. A1 - Straub, D. T1 - Assessing and updating the reliability of concrete bridges subjected to spatial deterioration - principles and software implementation N2 - Inspection and maintenance of concrete bridges is a major cost factor in transportation infrastructure, and there is significant potential for using information gained during inspection to update predictive models of the performance and reliability of such structures. In this context, this paper presents an approach for assessing and updating the reliability of prestressed concrete bridges subjected to chloride-induced reinforcement corrosion. The system deterioration state is determined based on a Dynamic Bayesian Network (DBN) model that considers the spatial variability of the corrosion process. The overall system reliability is computed by means of a probabilistic structural model coupled with the deterioration model. Inspection data are included in the system reliability calculation through Bayesian updating on the basis of the DBN model. As proof of concept, a software prototype is developed to implement the method presented here. The software prototype is applied to a typical highway bridge and the influence of inspection information on the system deterioration state and the structural reliability is quantified taking into account the spatial correlation of the corrosion process. This work is a step towards developing a software tool that can be used by engineering practitioners to perform reliability assessments of ageing concrete bridges and update their reliability with inspection and monitoring data. KW - Structural reliability KW - Dynamic Bayesian Networks KW - Spatial deterioration KW - Inspection KW - Monitoring general KW - Analysis and design methods KW - Reinforcement KW - Corrosion KW - Prestressed concrete PY - 2015 DO - https://doi.org/10.1002/suco.201500014 SN - 1464-4177 VL - 16 IS - 3 SP - 356 EP - 365 PB - Ernst & Sohn CY - Berlin AN - OPUS4-34336 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Dümichen, Erik A1 - Barthel, Anne-Kathrin A1 - Braun, Ulrike A1 - Bannick, Claus Gerhard A1 - Brand, K. A1 - Jekel, M. A1 - Senz, R. T1 - Analysis of polyethylene microplastics in environmental samples, using a thermal decomposition method N2 - Small polymer particles with a diameter of less than 5 mm called microplastics find their way into the environment from polymer debris and industrial production. Therefore a method is needed to identify and quantify microplastics in various environmental samples to generate reliable concentration values. Such concentration values, i.e. quantitative results, are necessary for an assessment of microplastic in environmental media. This was achieved by thermal extraction in thermogravimetric analysis (TGA), connected to a solid-phase adsorber. These adsorbers were subsequently analysed by thermal desorption gas chromatography mass spectrometry (TDS-GC-MS). In comparison to other chromatographic methods, like pyrolyse gas chromatography mass spectrometry (Py-GC-MS), the relatively high sample masses in TGA (about 200 times higher than used in Py-GC-MS) analysed here enable the measurement of complex matrices that are not homogenous on a small scale. Through the characteristic decomposition products known for every kind of polymer it is possible to identify and even to quantify polymer particles in various matrices. Polyethylene (PE), one of the most important representatives for microplastics, was chosen as an example for identification and quantification. KW - Microplastic KW - Identification and quantification of polymers KW - Thermogravimetric analysis KW - Evolved gas analysis KW - Gas chromatography mass spectroscopy PY - 2015 DO - https://doi.org/10.1016/j.watres.2015.09.002 SN - 0043-1354 VL - 85 SP - 451 EP - 457 PB - Elsevier Ltd. CY - Amsterdam AN - OPUS4-34337 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Dümichen, Erik A1 - Braun, Ulrike A1 - Kraemer, R. A1 - Deglmann, P. A1 - Senz, R. T1 - Thermal extraction combined with thermal desorption: A powerful tool to investigate the thermo-oxidative degradation of polyamide 66 materials N2 - Using thermogravimetric analysis (TGA) with a solid-phase adsorber for thermal extraction, followed by subsequently analysing the adsorber with thermo-desorption gas chromatography mass spectrometry (TDS-GC–MS) enables measurement of polymer degradation under oxidizing atmosphere, and the identification of certain complex hydrocarbon degradation products by chromatographic separation and defined mass patterns. This technique, thermal-extraction desorption gas chromatography mass spectrometry (TED-GC–MS) was used to investigate the thermo-oxidative degradation of PA 66 and PA 66 doped with 2 wt% of metal oxide particles. In TGA pure PA 66 formed more residue under an oxidizing atmosphere than an inert one. In contrast to the measurements under inert atmosphere, several condensed aromatic species containing nitrogen could be identified in thermo-oxidative measurements. These degradation products were formed through condensation reactions of primary amides originating from imide hydrolysis. The formation of such highly condensed species also causes higher char formation. Four metal oxides have shown an impact on the thermo-oxidative degradation of PA 66: Fe2O3 on η-Al2O3 < pure Fe2O3 = Fe2O3 on γ-Al2O3 < pure ZnO. For ZnO even a char-stabilizing effect could be observed. A catalytic effect of these metal oxides causes more condensed cyclopentanone and pyridine derivates. Thus, more water is formed and released, resulting in increased hydrolysis of the imides and degradation at lower temperatures. KW - PA 66 KW - Metal oxide particles KW - Thermo-oxidation KW - Thermogravimetry KW - Solid-phase extraction PY - 2015 DO - https://doi.org/10.1016/j.jaap.2015.08.006 SN - 0165-2370 SN - 1873-250X VL - 115 SP - 288 EP - 298 PB - Elsevier B.V. CY - Amsterdam AN - OPUS4-34338 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Pfuch, A. A1 - Beck, Uwe A1 - Lange, Thorid A1 - Rietz, U. A1 - Küzün, B. A1 - Twardygrosz, R. T1 - Wie Klebungen einfacher validiert werden können N2 - Die Bestimmung der Haftfestigkeit von Lackierungen, Beschichtungen oder Klebungen ist wichtig für die Beurteilung von entsprechenden Fertigungsabläufen. Unter Verwendung einer neuen Zentrifugentechnik wurde jetzt ein neues Mehr-Proben-Konzept zur schnellen Validierung von Klebverbindungen entwickelt. KW - Klebfestigkeit KW - Haftfestigkeit KW - Mehr-Proben-Vorbehandeln/Kleben/Prüfen PY - 2015 SN - 0001-8198 VL - 9 SP - 44 EP - 52 PB - Vieweg CY - Wiesbaden AN - OPUS4-34282 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Krankenhagen, Rainer A1 - Worzewski, Tamara A1 - Maierhofer, Christiane T1 - Cooling-down of thermal thick probes after flash excitation - A measure for the real energy density? N2 - Though flash lamps are one of the most applied heat sources in the field of Thermographic Testing (TT) using active thermography, only little is known about the actually achieved energy input into test objects. In this paper, an easy to realize sensor concept is proposed and experimentally evaluated. The concept is based on the measurement of the surface temperature of a thermal thick probe after flash excitation. After considering the sensor concept with FEM simulations the experimental investigation of four materials (two polymer and two building materials) is described. It will be shown that a suited coating is essential for the realization of the sensor concept. The experimental results prove the suitability of black rigid PVC as the most promising material. Using a coated PVC sample the energy density of short laser pulses, similar to flashes of flash lamps, could be determined exactly with an estimated relative uncertainty of only a few percent. KW - Infrared thermography KW - Flash lamps KW - Flash excitation KW - Flash thermography PY - 2015 DO - https://doi.org/10.1016/j.infrared.2015.07.014 SN - 1350-4495 VL - 72 SP - 258 EP - 265 PB - Pergamon Press CY - Oxford AN - OPUS4-34284 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Busse, F. A1 - Heidrich, C. A1 - Kleine, M. A1 - Sander, C. A1 - Ünal, Murat T1 - BEGLARES II Protection and restoration of monumental concrete-glazing with cathodic protection systems N2 - Since the 1950's, art has been fascinated by concrete glazing. In countless buildings of the post-war period they determine the lighting effect of the space by its function as luminous walls. A peculiar kind of stained glass from partially filigree compositions of two such contrasting materials: delicate, luminous glass and rough, austere concrete. Artistically designed components, which are equipped with a range of stylistic subtleties. But even after o short time of exposure a whole catalogue of damage patterns has been revealed, which documents the decay processes, such as the carbonation initiated corrosion of reinforcement. Cathodic protection is already used in a wide range of repair of concrete structures. Taking into account technical and historical preservation requirements, this research project aims to transfer these techniques to the conservation of concrete-glazing under less health risk, cost and work effort. T2 - 9th Forum for the conservation and technology of historic stained-glass CY - Paris, France DA - 08.07.2015 KW - Concrete-glazing KW - Dalles de verres KW - Cathodic corrosion protection KW - Heritage KW - Restoration KW - Maintenance PY - 2015 SN - 978-2-9543731-1-9 SP - 82 EP - 90 AN - OPUS4-34286 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Dutto, Paola A1 - Stickle, M.M. A1 - Manzanal, D. A1 - Hernán, A.Y. A1 - Pastor, M. ED - Onate, E. ED - Owen, D.R.J. ED - Peric, D. ED - Chiumenti, M. T1 - Modelling of propagation with SPH of 1966 Aberfan flowslide: special attention to the role of rheology and pore water pressure N2 - Landslides can cause major economic damage and a large number of casualities as it is possible to see from past events occurred all over the world. Being able to predict these kind of hazards would then suppose the achievement of great benefits. Here a model that combines a depth integrated description of the soil-pore fluid mixture together with a set of 1D models dealing with pore pressure evolution within the soil mass is presented. The mathematical model is based on the Biot-Zienkiewicz equations, from where a depth averaged model is derived. Concerning the material behaviour, the approach used is the one suggested by the Perzyna viscoplasticity, which has been extensively used in the past to model solid behaviour prior to failure. In this framework, a simple shear rheological model is derived, providing the basal friction needed in depth integrated models. The Smoothed Particle Hydrodynamics (SPH) has been the numerical technique chosen to spatially discretised the depth integrated equations of the mathematical model. The purpose of this work is to apply the SPH depth integrated numerical model, together with the sub-model that predicts the evolution of the pore water pressure inside the landslide, to simulate the propagation phase of the Aberfan flowslide occurred in 1966. T2 - COMPLAS XIII - 13th International conference on computational plasticity - Fundamentals and applications CY - Barcelona, Spain DA - 01.09.2015 KW - Numerical modelling KW - Smoothed particle hydrodynamics KW - SPH KW - Fluidised geomaterials KW - Aberfan flowslide PY - 2015 UR - http://congress.cimne.com/complas2015/frontal/doc/EbookComplas2015.pdf SN - 978-84-944244-6-5 SP - 151 EP - 161 AN - OPUS4-34290 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Smith, T. A1 - Lohrer, Christian T1 - Are shells "safety" distances "safe"? N2 - There is a wide variety of approaches across the world in determining appropriate “safety distances” for firework displays. Comparison of the different national approaches and distances for Shells derived from Shellcalc© highlights the variety and derivation of the “safety distances” adopted and these distances are related to the various failure modes of Shells that may affect the audience. In particular the effects of angled mortars and wind are compared and considered. It is not intended that this paper should encourage the maximum distances derived always to be adopted, but that an appreciation of the probabilities and hazards of various accident scenarios and therefore the risks involved be part of the decision making process for designers and commissioners of displays as well as enforcing authorities. T2 - 15th International symposium on fireworks CY - Bordeaux, France DA - 21.09.2015 KW - Display fireworks PY - 2015 SN - 978-0-9867279-8-6 SP - 90 EP - 102 AN - OPUS4-34343 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Douet, Marianne A1 - Lohrer, Christian A1 - Kurth, Lutz A1 - Mücke, Olaf T1 - Safety related behavior of cylindrical shells N2 - The European Standard series EN 16261 consisting of four parts deals with the testing and assessment of display fireworks in order to satisfy the essential safety requirements of the Directive 2007/23/EC which have to be met before placing these articles on the EU market. The current Version of this Standard provides mortar dimension limits to be used for the assessment of burst heights of spherical Shells, but lacks corresponding provisions for cylindrical shells. The aim of this study was threefold: 1. To check whether the requirements for spherical shells would overlap with the ones for cylindrical shells, 2. To compare several test procedures for height measurements with each other to minimize the measurement uncertainty of the effect dimensions, and 3. To evaluate drift distances in order to check whether the current national provisions on safety distances for Professional fireworks displays need adaption during the implementation of the new European directive 2013/29/EU on pyrotechnics in German legislation. For this study, a large number of cylindrical shells was specifically manufactured to guarantee lull control on all relevant constructional aspects. These shells were designed with a smoke tracer and no burst Charge so that they would fall back to the ground in order to investigate their drift distances. Their gross mass corresponded to commercially available display shells, though, consisting of defined inert substances inside the shell. The following Parameters were varied in this study: caliber (75 mm, 100 mm, 150 mm), shell length per caliber (single and double length), lift Charge (hard and soft burst effect), mortar length per caliber (short and long). In total, more than 120 shells were manufactured and tested. Results show a good application of the proposed test procedures regarding the mortar dimensions given in the Standard series for cylindrical shells as well. The following test procedures were part of this study: Radar Doppler System, video grammetric System, universal surveying instruments, and mortar internal pressure measurements. Observed drift distances in relation to the caliber and effect heights are discussed and assessed. T2 - 15th International symposium on fireworks CY - Bordeaux, France DA - 21.09.2015 KW - Radar-Doppler KW - Height measurements KW - Drift effects KW - Safety distances PY - 2015 SN - 978-0-9867279-8-6 SP - 104 EP - 122 AN - OPUS4-34344 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kennedy, D.C. A1 - Orts-Gil, G. A1 - Lai, C.-H. A1 - Müller, Larissa A1 - Haase, A. A1 - Luch, A. A1 - Seeberger, P. H. T1 - Carbohydrate functionalization of silver nanoparticles modulates cytotoxicity and cellular uptake N2 - Background Increasing use of silver nanoparticles (Ag-NPs) in various products is resulting in a greater likelihood of human exposure to these materials. Nevertheless, little is still known about the influence of carbohydrates on the toxicity and cellular uptake of nanoparticles. Methods Ag-NPs functionalized with three different monosaccharides and ethylene glycol were synthesized and characterised. Oxidative stress and toxicity was evaluated by protein carbonylation and MTT assay, respectively. Cellular uptake was evaluated by confocal microscopy and ICP-MS. Results Ag-NPs coated with galactose and mannose were considerably less toxic to neuronal-like cells and hepatocytes compared to particles functionalized by glucose, ethylene glycol or citrate. Toxicity correlated to oxidative stress but not to cellular uptake. Conclusions Carbohydrate coating on silver nanoparticles modulates both oxidative stress and cellular uptake, but mainly the first has an impact on toxicity. These findings provide new perspectives on modulating the bioactivity of Ag-NPs by using carbohydrates. KW - Silver KW - Nanoparticles KW - Carbohydrates KW - Nanotoxicology KW - Bio-Interfaces PY - 2014 UR - http://www.jnanobiotechnology.com/content/12/1/59 DO - https://doi.org/10.1186/s12951-014-0059-z SN - 1477-3155 VL - 12 IS - 59 SP - 1 EP - 8 PB - BioMed Central CY - London AN - OPUS4-34345 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Vogl, Jochen T1 - Bestimmung der Blei-Isotopenzusammensetzung von mittelalterlichen Pilgerzeichen N2 - Determination of the Pb isotopic composition in medieval pilgrim badges - Micro samples of approximately 1 mg or less were obtained from the backside of 12medieval pilgrim badges. After cleaning with water in an ultrasonic bath the samples were dissolved and the Pb was separated by chromtographic means. In the isolated Pb fractions the Pb isotope ratios were determined by thermal ionization mass spectrometry with expanded measurement uncertainties of less than 0.1 %. The determined Pb isotopic composition of the pilgrim badges spread over the whole range of the European and Mediterranean ore deposits. Nine of twelve pilgrim badges agree with Central European deposits, while three pilgrim badges show a different Pb isotopic composition covering either Mediterranean, or Aegean or Mid to Eastern European sources. Interestingly most of the ore deposits allocated by the Pb isotopic composition of the pilgrim badges do not agree with the known place of manufacture. KW - Mittelalterliche Pilgerzeichen KW - Herkunft KW - Lagerstätten KW - Blei-Isotopie KW - Thermionenmassenspektrometrie PY - 2015 SN - 0035-7812 VL - 110 IS - 1-2 SP - 44 EP - 47 PB - Herder CY - Rom ; Freiburg,Br. ; Wien AN - OPUS4-34346 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Höhm, S. A1 - Rosenfeld, A. A1 - Krüger, Jörg A1 - Bonse, Jörn T1 - Laser-induced periodic surface structures on titanium upon single- and two-color femtosecond double-pulse irradiation N2 - Single- and two-color double-fs-pulse experiments were performed on titanium to study the dynamics of the formation of laser-induced periodic surface structures (LIPSS). A Mach-Zehnder inter-ferometer generated polarization controlled (parallel or cross-polarized) double-pulse sequences in two configurations – either at 800 nm only, or at 400 and 800 nm wavelengths. The inter-pulse delays of the individual 50-fs pulses ranged up to some tens of picoseconds. Multiple of these single- or two-color double-fs-pulse sequences were collinearly focused by a spherical mirror to the sample surface. In both experimental configurations, the peak fluence of each individual pulse was kept below its respective ablation threshold and only the joint action of both pulses lead to the formation of LIPSS. Their resulting characteristics were analyzed by scanning electron microscopy and the periods were quantified by Fourier analyses. The LIPSS periods along with the orientation allow a clear identification of the pulse which dominates the energy coupling to the material. A plasmonic model successfully explains the delay-dependence of the LIPSS on titanium and confirms the importance of the ultrafast energy deposition stage for LIPSS formation. PY - 2015 DO - https://doi.org/10.1364/OE.23.025959 SN - 1094-4087 VL - 23 IS - 20 SP - 25959 EP - 25971 PB - Optical Society of America CY - Washington, DC AN - OPUS4-34354 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Golze, Manfred A1 - Hedrich, Martina T1 - Qualitätsmanagement im analytischen Labor - Ein Thema mit vielen Facetten (II) N2 - Ein Qualitätsmanagement (QMS) nach DIN EN ISO/IEC 17025 [1] für ein analytisches Labor muss technische Anforderungen (s. [2]) und Managementanforderungen umsetzen. Letztere werden hier kurz vorgestellt. Als Kompetenzbestätigung durch eine unabhängige Stelle kommt heute der Akkreditierung des Labors, für die das QMS eine Voraussetzung ist, eine wesentliche Bedeutung zu. KW - Qualitätsmanagement KW - Audits KW - Managementbewertungen KW - ISO/IEC 17025 KW - ISO/IEC 15189 KW - Akkreditierung KW - Gute Laborpraxis PY - 2015 SN - 0016-3538 IS - 9 SP - 62 EP - 64 PB - GIT-Verlag CY - Darmstadt AN - OPUS4-34294 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Tamberg, Tomas A1 - Kunze, Sebastian A1 - Rippe, P. T1 - Die Bewertung der Dekontaminierbarkeit von Oberflächen nach DIN 25415, Teil 1 und die Anwendung von Bewertungsschlüsseln auf der Basis von Teilergebnissen PY - 1985 SN - 0171-5747 VL - 46 IS - 2 SP - 1 EP - 16 PB - Hanser CY - München AN - OPUS4-34251 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Weise, Hans-Peter A1 - Jost, Peter ED - Hacke, J. ED - Borchardt, D. ED - Kaul, A. T1 - Bestimmung der Körperdosis bei externer Strahlenexposition durch Photonenstrahlen (Fallstudie) PY - 1985 SN - 3-87344-074-1 SP - 1 EP - 16 PB - Hoffmann CY - Berlin AN - OPUS4-34253 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Bathke, Werner T1 - Schweißen in kaltverformten Bereich an Winkelproben mit 6 mm Schenkeldicke PY - 1985 SN - 0036-7184 VL - 37 IS - 11 SP - 580 EP - 584 PB - Verl. für Schweißen u. Verwandte Verfahren, DVS-Verl. CY - Düsseldorf AN - OPUS4-34256 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Florian, Wolfgang A1 - Jafari, S. T1 - Meßtechnische Erfassung von Bondparametern PY - 1985 SN - 0172-6250 SN - 0943-0962 SP - 365 EP - 367 PB - Konradin-Verl. CY - Leinfelden-Echterdingen AN - OPUS4-34258 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Shirshova, N. A1 - Bismarck, A. A1 - Greenhalgh, E.S. A1 - Johansson, P. A1 - Kalinka, Gerhard A1 - Marczewski, M.J. A1 - Shaffer, M.S.P. A1 - Wienrich, Malte T1 - Composition as a means to control morphology and properties of epoxy based dual-phase structural electrolytes N2 - Structural electrolytes were prepared using a fully formulated commercially available high performance epoxy resin (MTM57) and an ionic liquid based electrolyte: lithium bis(trifluoromethylsulfonyl)imide (LiTFSI) dissolved in 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide (EMIM-TFSI). Through a systematic study, the composition of the formulations was found to have a greater effect than the curing temperature on the morphology and properties of the resulting structural electrolytes. The presence of lithium salt is essential to form a structurally homogeneous electrolyte. Bicontinuous morphologies containing continuous (coarse) epoxy networks surrounded by connected spherical epoxy nodules were obtained with different length scales upon varying the lithium salt concentration. Increasing the LiTFSI concentration improved the miscibility of MTM57 with the electrolyte and decreased the characteristic length scale of the resulting bicontinuous microstructure. The properties of the structural electrolytes correlated with the morphology, showing increased Young’s modulus and decreased ionic conductivity with increasing lithium salt concentration. The miscibility of the epoxy system with the electrolyte was also improved by substitution of EMIM-TFSI with an equal weight of an aprotic organic solvent, propylene carbonate (PC); however, the window of PC concentrations which resulted in structural electrolytes with bicontinuous microstructures was very narrow; at PC concentrations above 1 wt %, gel-like polymers with no permanent mesoporosity were obtained. KW - Functional composites KW - Mechanical properties KW - Elastic properties KW - Epoxy KW - Morphology KW - Electrolyte PY - 2014 DO - https://doi.org/10.1021/jp507952b SN - 1932-7447 SN - 1089-5639 VL - 118 IS - 49 SP - 28377 EP - 28387 PB - Soc. CY - Washington, DC AN - OPUS4-34565 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Radl, S. A1 - Kreimer, M. A1 - Manhart, J. A1 - Griesser, T. A1 - Moser, A. A1 - Pinter, G. A1 - Kalinka, Gerhard A1 - Kern, W. A1 - Schlögl, S. T1 - Photocleavable epoxy based materials N2 - The present study aims at the development of photodegradable epoxy based materials comprising o-nitrobenzyl ester links that undergo well defined bond cleavage in response to UV irradiation. New bi-functional epoxy based monomers bearing o-nitrobenzyl ester groups are synthesized and thermally cured with an anhydride hardener to yield photosensitive polymers and duromers. The UV induced changes in solubility are exploited for the preparation of positive-type photoresists. Thin patterned films are obtained by photolithographic processes and characterized by microscopic techniques. The results evidence that sensitive resist materials with good resolution and high contrast behavior can be accomplished. Along with resist technology, the applicability of o-nitrobenzyl chemistry in the design of recyclable polymer materials with thicknesses in the millimeter range is evaluated. By monitoring the thermo-mechanical properties upon UV illumination, a distinctive depletion of storage modulus and glass transition temperature is observed with increasing exposure dose. Additionally, single fiber pull-out tests are carried out revealing a significant decrease of the interfacial adhesion at the fiber-matrix interface due to the phototriggered cleavage reaction. KW - Epoxy based network KW - Photocleavage KW - o-Nitrobenzyl ester KW - Adhesion KW - Mechanical properties KW - Interfacial shear strength PY - 2015 DO - https://doi.org/10.1016/j.polymer.2015.05.055 SN - 0032-3861 SN - 1873-2291 VL - 69 SP - 159 EP - 168 PB - Elsevier Ltd. AN - OPUS4-34566 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Greenhalgh, E.S. A1 - Ankersen, J. A1 - Asp, L. E. A1 - Bismarck, A. A1 - Fontana, Q.P.V. A1 - Houlle, M. A1 - Kalinka, Gerhard A1 - Kucernak, A. A1 - Mistry, M. A1 - Nguyen, S. A1 - Qian, H. A1 - Shaffer, M.S.P. A1 - Shirshova, N. A1 - Steinke, J.H.G. A1 - Wienrich, Malte T1 - Mechanical, electrical and microstructural characterisation of multifunctional structural power composites N2 - Multifunctional composites which can fulfil more than one role within a system have attracted considerable interest. This work focusses on structural supercapacitors which simultaneously carry mechanical load whilst storing/delivering electrical energy. Critical mechanical properties (in-plane shear and in-plane compression performance) of two monofunctional and four multifunctional materials were characterised, which gave an insight into the relationships between these properties, the microstructures and fracture processes. The reinforcements included baseline T300 fabric, which was then either grafted or sized with carbon nanotubes, whilst the baseline matrix was MTM57, which was blended with ionic liquid and lithium salt (two concentrations) to imbue multifunctionality. The resulting composites exhibited a high degree of matrix heterogeneity, with the ionic liquid phase preferentially forming at the fibres, resulting in poor matrix-dominated properties. However, fibre-dominated properties were not depressed. Thus, it was demonstrated that these materials can now offer weight savings over conventional monofunctional systems when under modest loading. KW - Carbon fibres KW - Functional composites KW - Mechanical properties KW - Elastic properties KW - Fractography PY - 2014 DO - https://doi.org/10.1177/0021998314554125 SN - 0021-9983 SN - 1530-793X SP - 1 EP - 12 PB - Sage CY - London AN - OPUS4-34567 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Qian, Hui A1 - Bismarck, A. A1 - Greenhalgh, E.S. A1 - Kalinka, Gerhard A1 - Shaffer, M.S.P. T1 - Hierarchical composites reinforced with carbon nanotube grafted fibers: The potential assessed at the single fiber level N2 - The feasibility of reinforcing conventional carbon fiber composites by grafting carbon nanotubes (CNTs) onto the fiber surface has been investigated. Carbon nanotubes were grown on carbon fibers using the chemical vapor deposition (CVD) method. Iron was selected as the catalyst and predeposited using the incipient wetness technique before the growth reaction. The morphology of the products was characterized using scanning electron microscopy (SEM), which showed evidence of a uniform coating of CNTs on the fiber surface. Contact angle measurements on individual fibers, before and after the CNT growth, demonstrated a change in wettability that can be linked to a change of the polarity of the modified surface. Model composites based on CNT-grafted carbon fibers/epoxy were fabricated in order to examine apparent interfacial shear strength (IFSS). A dramatic improvement in IFSS over carbon fiber/epoxy composites was observed in the single fiber pull-out tests, but no significant change was shown in the push-out tests. The different IFSS results were provisionally attributed to a change of failure mechanism between the two types of tests, supported by fractographic analysis. KW - Composites KW - Nano tubes KW - Grafting KW - Interface PY - 2008 DO - https://doi.org/10.1021/cm702782j SN - 0897-4756 SN - 1520-5002 VL - 20 IS - 5 SP - 1862 EP - 1869 PB - American Chemical Society CY - Washington, DC AN - OPUS4-34568 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Daschewski, Maxim A1 - Kreutzbruck, Marc A1 - Prager, Jens T1 - Influence of thermodynamic properties of a thermo-acoustic emitter on the efficiency of thermal airborne ultrasound generation N2 - In this work we experimentally verify the theoretical prediction of the recently published Energy Density Fluctuation Model (EDF-model) of thermo-acoustic sound generation. Particularly, we investigate experimentally the influence of thermal inertia of an electrically conductive film on the efficiency of thermal airborne ultrasound generation predicted by the EDF-model. Unlike widely used theories, the EDF-model predicts that the thermal inertia of the electrically conductive film is a frequency-dependent parameter. Its influence grows non-linearly with the increase of excitation frequency and reduces the efficiency of the ultrasound generation. Thus, this parameter is the major limiting factor for the efficient thermal airborne ultrasound generation in the MHz-range. To verify this theoretical prediction experimentally, five thermo-acoustic emitter samples consisting of Indium-Tin-Oxide (ITO) coatings of different thicknesses (from 65 nm to 1.44 lm) on quartz glass substrates were tested for airborne ultrasound generation in a frequency range from 10 kHz to 800 kHz. For the measurement of thermally generated sound pressures a laser Doppler vibrometer combined with a 12 lm thin polyethylene foil was used as the sound pressure detector. All tested thermo-acoustic emitter samples showed a resonance-free frequency response in the entire tested frequency range. The thermal inertia of the heat producing film acts as a low-pass filter and reduces the generated sound pressure with the increasing excitation frequency and the ITO film thickness. The difference of generated sound pressure levels for samples with 65 nm and 1.44 lm thickness is in the order of about 6 dB at 50 kHz and of about 12 dB at 500 kHz. A comparison of sound pressure levels measured experimentally and those predicted by the EDF-model shows for all tested emitter samples a relative error of less than ±6%. Thus, experimental results confirm the prediction of the EDF-model and show that the model can be applied for design and optimization of thermo-acoustic airborne ultrasound emitters. KW - Thermophone KW - Thermo-acoustic effect KW - Thermal sound generation KW - Resonance-free ultrasound emitter KW - Energy density fluctuation KW - Thermal inertia PY - 2015 DO - https://doi.org/10.1016/j.ultras.2015.06.008 SN - 0041-624x VL - 63 SP - 16 EP - 22 PB - Elsevier B.V. CY - Amsterdam AN - OPUS4-34573 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Millar, Steven A1 - Wilsch, Gerd A1 - Eichler, Thorsten A1 - Gottlieb, Cassian A1 - Wiggenhauser, Herbert T1 - Laser induced breakdown spectroscopy (LIBS) im Bauwesen - automatisierte Baustoffanalyse N2 - Die Laser induzierte Breakdown Spektroskopie (LIBS) bietet für die Analyse heterogener, mineralischer Baustoffe, wie z. B. Beton, deutliche Vorteile gegenüber konventionellen Methoden. Sie ermöglicht neben der Quantifizierung von Elementgehalten und -verteilungen im Baustoff auch die Differenzierung von Elementkonzentrationen innerhalb einzelner Phasen im Baustoff. So können beispielsweise die für die Alkali-Kieselsäure-Reaktion (AKR) interessanten Natriumkonzentrationen bestimmt und hinsichtlich ihrer Verteilung aufgelöst werden. Es lassen sich Natriumgehalte, welche sich in der Gesteinskörung befinden, separat von denen der Betonmatrix bestimmen. Der vorliegende Artikel befasst sich mit den Vor- und Nachteilen von LIBS als alternative Methode für die chemische Analyse von Baustoffen. Anhand von Beispielen aus der Praxis wird der derzeitige Stand der Technik dargestellt und ein Vergleich mit etablierten Messmethoden vorgenommen. Compared to conventional methods the Laser Induced Breakdown Spectroscopy (LIBS) provides significant advantages for analysis of heterogeneous, mineral building materials as e.g. concrete. Besides providing the possibility to quantify element concentrations and distributions in building materials, this technique enables also to differentiate concentrations within different phases of the material. It is possible to determine sodium concentrations and distribution directly, which e.g. is important when regarding Alkali-Silica-Reaction (ASR). Sodium contents provided by the aggregates can be distinguished from those provided by the concrete matrix. The present article is concerned with the advantages and disadvantages of LIBS as alternative method for chemical analysis of building materials. On the basis of samples from practice the current state of the art is shown and different measurement techniques will be compared. KW - Chloride KW - Alkali-Kieselsäure-Reaktion KW - AKR KW - RFA KW - Elementanalyse KW - Natrium KW - Baustoffuntersuchungen KW - Titration KW - Carbonatisierung KW - Baustoffe KW - Dauerhaftigkeit KW - Lebensdauer KW - Messsysteme KW - Qualitätssicherung KW - Alkali-silica-reaction KW - XRF KW - Element analysis KW - Sodium KW - Building materials analysis KW - Potentiometric titration KW - Carbonation KW - Bauwerkserhaltung/Instandsetzung KW - Korrosion PY - 2015 DO - https://doi.org/10.1002/best.201500030 SN - 0005-9900 SN - 1437-1006 VL - 110 IS - 8 SP - 501 EP - 510 PB - Ernst CY - Berlin AN - OPUS4-34580 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Madkour, Sherif Aly Hassan Aly A1 - Yin, Huajie A1 - Füllbrandt, Marieke A1 - Schönhals, Andreas T1 - Calorimetric evidence for a mobile surface layer in ultrathin polymeric films: poly(2-vinyl pyridine) N2 - Specific heat spectroscopy was used to study the dynamic glass transition of ultrathin poly(2-vinyl pyridine) films (thicknesses: 405–10 nm). The amplitude and the phase angle of the differential voltage were obtained as a measure of the complex heat capacity. In a traditional data analysis, the dynamic glass transition temperature Tg is estimated from the phase angle. These data showed no thickness dependency on Tg down to 22 nm (error of the measurement of ±3 K). A derivative-based method was established, evidencing a decrease in Tg with decreasing thickness up to 7 K, which can be explained by a surface layer. For ultrathin films, data showed broadening at the lower temperature side of the spectra, supporting the existence of a surface layer. Finally, temperature dependence of the heat capacity in the glassy and liquid states changes with film thickness, which can be considered as a confinement effect. PY - 2015 DO - https://doi.org/10.1039/c5sm01558h SN - 1744-683X VL - 11 IS - 40 SP - 7942 EP - 7952 PB - RSC Publ. CY - Cambridge AN - OPUS4-34605 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Alver, Ninel A1 - Wiggenhauser, Herbert T1 - Modified SIBI application to scanning impact-echo T2 - 12th International Conference and Exhibition "Structural Faults & Repair 2008" CY - Edinburgh, Scotland DA - 2008-06-10 KW - Impact echo KW - Zerstörungsfreie Prüfung PY - 2008 SN - 0-947644-63-5 PB - Engineering Technics Pr., CY - Edinburgh AN - OPUS4-34608 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wiggenhauser, Herbert ED - Büyüköztürk, O. T1 - Automated NDE of structures with combined methods N2 - Non-Destructive Evaluation (NDE) of structures is complex due to the uniqueness of almost all structures and their sizes. A single NDT method typically is not sufficient to meet the testing requirements, which cover different areas, such as material and structural properties. Measuring geometrical properties require other test methods than e.g. the detection of corrosion. Automation has proven to be necessary for aquiring large amounts a of high quality data in a short time. Examples of succesful method combinations from different areas of non-destructive testing in civil engineering are briefly described and their application is shown. Some of the examples also include automated inspection. T2 - International Symposium on Nondestructive Testing of Materials and Structures CY - Istanbul, Turkey DA - 15.05.2011 KW - Zerstörungsfreie Prüfung KW - Automatisierung KW - Inspektion PY - 2013 SN - 978-94-007-0722-1 DO - https://doi.org/10.1007/978-94-007-0723-8_107 N1 - Serientitel: RILEM bookseries – Series title: RILEM bookseries IS - 6 SP - 753 EP - 760 PB - Springer CY - Dordrecht AN - OPUS4-34609 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Reddy, K. M. A1 - Kudalkar, V. N. A1 - Madhusudan, C. P. A1 - Wiggenhauser, Herbert T1 - A NDT in civil engineering software for multiple testing methods KW - Beton KW - Software KW - Zerstörungsfreie Prüfung PY - 2008 SN - 978-1-57117-180-1 SP - 295 EP - 302 CY - Oakland, CA, USA AN - OPUS4-34611 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Zhang, G. A1 - Wetzel, B. A1 - Jim, B. A1 - Österle, Werner T1 - Impact of counterface topography on the formation mechanisms of nanostructured tribofilm of PEEK hybrid nanocomposites N2 - The effect of steel counterface topography on the formation mechanisms of nanostructured tribofilms of polyetheretherketone (PEEK) hybrid nanocomposites was studied. Three types of surface finishes with mean roughness Ra ranging from nano- to micro-scale were investigated. Tribo-sintering of nanopartides, oxidation of counterface steel and compaction of wear debris are identified to be competing factors dominating the formation and function of the tribofilms. Counterface topography played an important role on the competing factors, and thereby influenced significantly the final structure, the load-carrying capability and the lubrication performance of the tribofilms. It was disclosed that a thin tribofilm, which mainly consists of silica nanoparticles and which forms on the counterface with a submicron roughness, benefits best the tribological performance of the composites KW - Surface topography KW - Nanocomposite KW - Tribology KW - Tribofilm PY - 2015 DO - https://doi.org/10.1016/j.triboint.2014.11.015 SN - 0301-679X VL - 83 SP - 156 EP - 165 PB - Butterworth-Heinemann CY - Oxford AN - OPUS4-34612 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Qiao, Linan A1 - Zencker, Uwe A1 - Völzke, Holger ED - Brandt, A. M. ED - Olek, J. ED - Glinicki, M. A. ED - Leung, C.K.Y. ED - Lis, J. T1 - Crushable foam model with pressure and stress-triaxiality dependent damage mechanisms for damping concrete N2 - Damping concrete with high energy absorption capability consists of a cement matrix with embedded small polystyrene balls and is investigated experimentally and numerically under high static compression with and without clamping. A material model is derived which describes the fundamental effects of damping concrete like non-linear elastic-plastic behaviour, volume change, volume strain dependent hardening as well as shear failure with an adequate description of damage initiation and evolution. The suggested material model is validated by simulation of penetration tests. T2 - BMC-11, International Symposium on Brittle Matrix Composites CY - Warsaw, Poland DA - 28.09.2015 KW - Damping concrete KW - Impact load KW - Crushable foam material model KW - Damage PY - 2015 SN - 978-83-89687-96-8 SP - 269 EP - 277 PB - Inst Fundamental Technological Research, Polish Acad Sciences CY - Warschau AN - OPUS4-34613 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Zerbst, Uwe A1 - Madia, Mauro T1 - Der Schwellenwert DKth als Auslegekriterium. Aktuelle Entwicklungen und Fragestellungen N2 - Bei der Bestimmung der Restlebensdauer zyklisch beanspruchter Bauteile kommt dem Schwellenwert für Ermüdungsrissausbreitung, K111, oft entscheidende Bedeutung zu. Dabei ist seine Anwendung weniger gesichert als bislang angenommen. Der Vortrag diskutiert Fragen der experimentellen Ermittlung des Schwellenwertes sowie seiner Anwendung auf Bauteile. Auf beiden Gebieten haben sich in den letzten Jahren Probleme ergeben, die bestehendes Wissen teilweise wieder in Frage stellen oder modifizieren. Im Beitrag diskutiert werden der Einfluss unterschiedlicher Rissschließmechanismen auf K111, Konsequenzen, die sich daraus hinsichtlich der Ermittlung und Übertragung des Kennwertes ergeben, sowie die Effekte von Einflussgrößen wie Spannungsverhältnis und Rissgröße, aber auch des Werkstoffgefüges und der damit korrelierten mechanischen Eigenschaften. T2 - 47. Tagung des DVM-Arbeitskreises Bruchvorgänge und Bauteilsicherheit - Bruchmechanische Werkstoff- und Bauteilbewertung: Beanspruchungsanalyse, Prüfmethoden und Anwendungen CY - Freiberg, Sachsen, Germany DA - 10.02.2015 PY - 2015 SN - 1616-4687 SP - 305 EP - 321 AN - OPUS4-34621 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Eberle, Arno T1 - Simulation der thermo-mechanischen Belastung eines Chipaufbaus während des Thermo-Kompressions-Bondens unter bruchmechanischen Aspekten T2 - 27. Vortragsveranstaltung des DVM-Arbeitskreises Bruchvorgänge PY - 1995 SN - 0943-3473 SP - 321 EP - 334 AN - OPUS4-34622 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Hahn, A. A1 - Zellmer, S. A1 - Riesselmann, B. A1 - Krüger, Simone A1 - Raspe, Tina A1 - Schwarz, Silke A1 - Stahn, Sebastian A1 - Urban, Klaus T1 - Carbon monoxide release curves from measurements during indoor charcoal burning: systematic research on toxic levels for humans N2 - The Federal Institute for Risk Assessment (BfR) DocCenter has received more and more reports of cases of carbon monoxide (CO) poisoning, some even with fatal outcomes after indoor use of charcoal grills. CO is odorless, colorless, non-irritant and does not produce any other warning effect perceptible to humans. The BfR and the Federal Institute for Materials Research and Testing (BAM) have completed a cooperative research project to investigate the toxic concentrations of CO that are reached when charcoal grills or open fires are used indoors. KW - Toxicity KW - Indoor charcoal burning PY - 2014 DO - https://doi.org/10.3109/15563650.2014.906213 SN - 1556-3650 VL - 52 IS - 4 SP - 351 PB - Informa Healthcare CY - Philadelphia, Pa. AN - OPUS4-34582 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Schneider, André A1 - Gumenyuk, Andrey A1 - Rethmeier, Michael T1 - Mobile vacuum in pocket format, mobile local low-pressure cap for high power laser beam welding of thick materials N2 - The presented apparatus enables laser beam welding of thick materials under local reduced pressure conditions, thus improving the quality of welds and reducing the laser beam power necessary for complete penetration welding. The vacuum cap presented in this article uses a local reduced ambient pressure environment in a tight zone around the welding area and, in contrast to a conventional vacuum chamber, it is movable in the welding direction. The mobile installation is very compact and reaches pressure values of around 200 mbar. The reduced pressure in the vacuum cap is sufficient to generate 50 % higher penetration depth in comparison to welding under ambient pressure conditions. The low pressure around the keyhole reduces the vapour-plasma plume and therefore prevents a defocusing and scattering of the laser radiation. This allows to raise the amount of laser beam power entering the keyhole as well as the effective power density. KW - High power laser beam welding KW - Mobile vacuum KW - Local reduced pressure KW - Vapor plume KW - Keyhole PY - 2015 DO - https://doi.org/10.1002/latj.201500025 SN - 1613-7728 SN - 1863-9119 VL - 12 IS - 4 SP - 43 EP - 44 PB - Wiley-VCH CY - Weinheim AN - OPUS4-34583 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Miccoli, Lorenzo A1 - Paganoni, S. A1 - Fontana, Patrick A1 - D'Ayala, D. T1 - Pull-out strength of anchor pins for brickwork masonry and earth block masonry / Auszugsfestigkeit von Verpressankern für Ziegel- und Lehmsteinmauerwerk N2 - In this paper results of the experimental testing performed on brick masonry and earth block masonry are presented. The paper outlines the development of the testing procedures for two different types of anchors. For this purpose, two experimental campaigns of pull-out tests on masonry corner connections strengthened by metallic rod grouted were carried out. Experimental results proved that the implemented testing procedures are suitable to determine the most recurring failure modes of the anchor pins. Moreover, a procedure is proposed to estimate the capacity of grouted anchor pins based on experimental studies. N2 - Mit diesem Beitrag soll die experimentelle Beurteilung von Verpressankern für Mauerwerk vorgestellt werden. Es wurden zwei Versuchsserien mit Ankerauszugsversuchen an Mauerwerksecken aus Ziegel- und Lehmsteinmauerwerk durchgeführt. Die Versuchsergebnisse haben gezeigt, dass die gewählten Versuchsabläufe geeignet sind, die am häufigsten wiederkehrenden Versagensarten der Verpressanker zu bestimmen. Darüber hinaus wird eine Vorgehensweise vorgeschlagen, die es ermöglicht, die Traglast von Verpressankern auf Basis experimenteller Untersuchungen abzuschätzen. KW - Brickwork masonry KW - Earth block masonry KW - Anchor pins KW - Bond strength KW - Pull-out test PY - 2015 DO - https://doi.org/10.1002/dama.201500669 SN - 1432-3427 SN - 1437-1022 N1 - Sprachen: Deutsch/Englisch - Languages: German/English VL - 19 IS - 5 SP - 383 EP - 393 PB - Ernst CY - Berlin AN - OPUS4-34634 LA - mul AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Miccoli, Lorenzo A1 - Fontana, Patrick A1 - Johansson, G. A1 - Zandi, K. A1 - Portal, Natalie Williams A1 - Müller, U. T1 - Numerical modelling of UHPC and TRC sandwich elements for building envelopes N2 - ln this paper a modelling approach is presented to reproduce the mechanical behaviour of sandwich panels via finite element analysis. Two types of panels were investigated in this scope of work. The first sandwich element was a textile reinforced concrete (TRC) panel with cellular lightweight concrete insulation and the second configuration was an ultra-high performances concrete (UHPC) panel with aerated autoclaved concrete insulation. The goal was to obtain a reliable numerical strategy that represents a reasonable compromise in terms of sufficient accuracy of the element characteristics and the computational costs. The results show the possibility of describing the composite action in a full sandwich panel. The achieved modelling approach will later be used for the optimization of TRC and UHPC panels in terms of minimizing the thickness, identifying the number and location of connectors, as well as evaluating varying anchorage Systems. T2 - IABSE conference - Structural engineering: Providing solutions to global challenges CY - Geneva, Switzerland DA - 23.09.2015 KW - Sandwich elements KW - Ultra-high performance concrete (UHPC) KW - Textile reinforced concrete (TRC) KW - Autoclaved aerated concrete (AAC) KW - Cellular lightweight concrete (CLC) KW - Finite element analysis (FEA) PY - 2015 SN - 978-3-85748-140-6 SP - 195 EP - 203 AN - OPUS4-34552 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Miccoli, Lorenzo A1 - Garofano, A. A1 - Fontana, Patrick A1 - Müller, U. T1 - Experimental testing and finite element modelling of earth block masonry N2 - The current paper focuses on the determination of reliable numerical models of earth block masonry wallettes under different loading conditions. Uniaxial compression and diagonal compression tests were performed. Experimental behaviour was modelled with a non-linear model able to describe the cracking behaviour. The simplified approach based on macro-modelling shows a satisfactory accuracy and low computational costs. The results reproducing the uniaxial compression are in good correspondence with the post-elastic behaviour observed in the experimental campaign. The micro-modelling approach adopted to reproduce the shear behaviour, even with high computational cost, represents a suitable tool to predict the masonry collapse mechanism. KW - Earth block masonry KW - Uniaxial compression test KW - Diagonal compression test KW - Numerical modelling KW - Macro-modelling approach KW - Micro-modelling approach PY - 2015 DO - https://doi.org/10.1016/j.engstruct.2015.09.020 SN - 0141-0296 VL - 104 SP - 80 EP - 94 PB - Elsevier CY - Oxford AN - OPUS4-34553 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Pontes Rodrigues, A. C. A1 - Nunes Ribeiro, P. J. A1 - Österle, Werner A1 - de Farias Azevedo, C. R. T1 - Failure analysis as a tool to optimize the design of a ring on disc tribotest investigating the role of surface roughness N2 - The influence of the surface roughness of pearlitic grey cast iron discs on the formation of tribofilms and the evolution of the friction coefficient during a ring on disc tribotest with the addition of magnetite and magnetite–graphite nanopowders as interfacial media was investigated. The roughness parameters of the cast iron discs were varied by electro discharge machining (EDM) and grinding processes, producing four distinct surface roughness conditions. The evolution of the friction coefficient, however, did not reach the steady state for most of the samples and the role of the surface roughness on the friction coefficient could not be identified. Focused ion beam (FIB) microscopy on the cast iron discs was carried out to investigate the microstructure of the discs near the tribosurface. These results showed that the EDM process not only varied the surface roughness, but also changed the microstructure of the cast iron discs, promoting the incipient fusion of the cast iron surface, with the formation of ridges and casting defects (pores). As a result, a layer of rapidly solidified metal with a dendritic microstructure was formed near to the surface of the EDMed discs. KW - Ring-on disc tribotest KW - Surface roughness KW - EDM-processing KW - Rapid solification PY - 2015 DO - https://doi.org/10.1016/j.engfailanal.2015.03.011 SN - 1350-6307 SN - 1873-1961 VL - 56 SP - 131 EP - 141 PB - Elsevier Science Publ. CY - Oxford AN - OPUS4-34623 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Gaal, Mate A1 - Dohse, Elmar A1 - Bartusch, Jürgen A1 - Kreutzbruck, Marc T1 - Luftschallprüfung von CFK mit planaren und fokussierenden Wandlern T2 - DACH-Jahrestagung 2015 CY - Salzburg, Austria DA - 2015-05-11 KW - Air-coupled KW - Ultrasonic testing KW - Ferroelectret KW - Cellular polypropylene KW - Transducer KW - Adhesive joint PY - 2015 SN - 978-3-940283-68-9 IS - DGZfP BB 152 SP - 1 EP - 9 AN - OPUS4-34629 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Dengel, Jörg A1 - Lohrer, Christian A1 - Stein, F. A1 - Perriam, J. T1 - Investigations on aerosol emissions of pyrotechnic smoke generators N2 - Pyrotechnic smoke generators fall under the Directive 2013/29/EU in Europe and could potentially belong to all categories except consumer fireworks. These types are especially present in the field of “Other Pyrotechnic Articles” of the categories P1 and P2, e.g. as simulation devices for paintball or airsoft gaming. The specific users of these products are aware of the corresponding smoke liberation during use and usually wear protective equipment to minimize exposure to potentially harmful aerosols. However, such products are often misused against the labelling requirements in locations where these articles are not supposed to be used, like football stadiums and demonstrations. In contrast to the intended use, uninvolved third parties are likely exposed to these reaction products without proper protective equipment. This study aims at identifying the transient particle size range of the aerosols emitted during the functioning of such common smoke generators for simulation purposes. In total four different types of articles were investigated, with five colors per type (white, blue, green, red, orange). Results show that the majority of the particles were emitted in a range between 40 nm and 350 nm, with some variation depending on the smoke color. Particles with diameters of less than 100 nm are generally of specific concern, as they can penetrate the alveolar system of the human lungs and therefore present a specific hazard. KW - FMPS KW - Simulation devices PY - 2016 VL - 2016 IS - 35 SP - 3 EP - 8 PB - Journal of Pyrotechnics CY - Cambridgeshire (UK) AN - OPUS4-35742 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Unnikrishnakurup, Sreedhar A1 - Krishnamurthy, C. V. A1 - Balasubramaniam, Krishnan T1 - Monitoring TIG welding using Infrared Thermography - Simulations and Experiments N2 - In the current work a 3D model has been developed to predict the thermal cycles during the Tungsten Inert Gas welding of Aluminum 2219. This paper describes the step by step procedure adopted to get the actual cooling rate during the TIG welding process both experimentally and numerically. The model was developed in the COMSOL Finite Element Package and considered a Gaussian heat distribution. The developed model then validated using the experimental data collected in field experiments on actual large propellant tanks. Temperature measurements were performed using Infrared Camera. Results show a close comparison between model and experiment. KW - Image Analysis KW - Infrared Thermography KW - Online Monitoring KW - Finite Element Method PY - 2016 DO - https://doi.org/10.15199/48.2016.04.02 SN - 0033-2097 IS - 4/2016 SP - 6 EP - 9 AN - OPUS4-35743 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Krüger, Oliver T1 - Recycled fertilizers: Do we need new regulations and analytical methods? N2 - More and more fertilizers emerge from recycled waste materials. This requires new analytical methods and/or the adaption of existing ones to new materials and matrices. KW - Environmenatal analysis KW - Resource recovery KW - Fertilizer PY - 2016 UR - http://www.sciencedirect.com/science/article/pii/S0956053X16000398 DO - https://doi.org/10.1016/j.wasman.2016.03.017 SN - 0956-053X VL - 50 SP - 1 EP - 2 PB - Elsevier Ltd. CY - Amsterdam AN - OPUS4-35654 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Richter, Frank A1 - Köppe, Enrico A1 - Daum, Werner T1 - Tracking deformation history in split Hopkinson pressure bar testing N2 - The stress vs. strain curve of materials is affected the rate of imposed straining. Among the methods for dynamic testing the technique known as 'split Hopkinson pressure bar' (SHPB) has evolved into the most widely used one to exert high-speed straining. The theory behind it comprises simple equations to compute stress and strain. The reliability of the strain analysis can be assessed by digital image correlation (DIC). The present results indicate that the visually observed strain is smaller than predicted by theory. T2 - 32nd Danubia-Adria Symposium on Advances in Experimental Mechanics CY - Starý Smokovec, Slovakia DA - 22.09.2015 KW - Split Hopkinson pressure bar (SHPB) KW - Digital image correlation (DIC) KW - Digitale Bildkorrelation (DIC) KW - Dynamic testing KW - Dynamische Tests KW - Stress-strain curve KW - Spannungs-Dehnungs-Kurve PY - 2015 SN - 978-80-554-1094-4 SP - 174 EP - 175 PB - University of Zilina, Slovakia CY - Zilina AN - OPUS4-35656 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Burbank, John A1 - Woydt, Mathias T1 - Optimization of pre-conditioned cold work hardening of steel alloys for friction and wear reductions under slip-rolling contact N2 - The goal of reducing CO2 emissions in the automobile industry has led to the development of increasingly efficient lightweight material solutions that yield enhanced performance. In light of this goal, this current work involves the optimization of the pre-conditioning of novel, high toughness steel bearings without thermo-chemical treatment, with the aim of transferring the running-in phase into the final step of the mechanical finishing process. A case-hardened gear steel and two novel non-case-hardened steels were evaluated. KW - Work hardening KW - Steel KW - Gear KW - Bearing KW - Residual stress KW - Hardness PY - 2016 DO - https://doi.org/10.1016/j.wear.2016.01.011 SN - 0043-1648 VL - 350-351 SP - 141 EP - 154 PB - Elsevier B.V. CY - Amsterdam, u.a. AN - OPUS4-35665 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Bartholmai, Matthias A1 - Kammermeier, Michael A1 - Koeppe, Tabea A1 - Werner, Klaus-Dieter ED - Nicoletto, G. ED - Pastrama, S.D. ED - Emri, I. T1 - High dynamic measurement of strain and acceleration using a multichannel measuring system with single cable serial connection N2 - Strain and acceleration measurement during high dynamic drop tests, e.g., of containments for dangerous goods is performed using high speed multichannel measuring systems. So far established and operated systems need a cable connection of every strain gauge and acceleration sensor with the measuring device, often counting up to a number of more than 100 cables, corresponding to the number of applied sensors. The result is a massive cable harness consisting of all single cables, which is difficult to handle and causes a number of practical problems. An innovative approach is proposed by using a single cable measuring system, consisting of measuring modules with data bus connection and local data acquisition. Promising results were presented in a previous study. This paper follows up with additional results from full-scale testing of a further enhanced single cable system for the application in drop tests. T2 - 32nd DANUBIA ADRIA SYMPOSIUM on Advances in Experimental Mechanics CY - Starý Smokovec, Slovakia DA - 22.09.2015 KW - Multichannel measuring KW - Single cable serial connection KW - Dangerous goods container KW - Drop test KW - High impact testing PY - 2016 DO - https://doi.org/10.1016/j.matpr.2016.03.023 SN - 2214-7853 VL - 3 IS - 4 SP - 931 EP - 935 PB - Elsevier Ltd. AN - OPUS4-35689 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Schürmann, Robin A1 - Bald, Ilko T1 - Decomposition of DNA nucleobases by laser irradiation of gold nanoparticles monitored by surface-enhanced Raman scattering N2 - Different approaches have been proposed to treat cancer cells using gold nanoparticles (AuNPs) in combination with radiation ranging from infrared lasers to high-energy ion beams. Here we study the decomposition of the DNA/RNA nucleobases thymine (T) and uracil (U) and the well-known radiosensitizer 5-bromouracil (BrU) in close vicinity to AuNPs, which are irradiated with a nanosecond pulsed laser (532 nm) matching the surface plasmon resonance of the AuNPs. The induced damage of nucleobases is analyzed by UV−vis Absorption spectroscopy and surface-enhanced Raman scattering (SERS). A clear DNA damage is observed upon laser irradiation. SERS spectra indicate the fragmentation of the aromatic ring system of T and U as the dominant form of damage, whereas with BrU mainly the cleavage of the Br−C bond and formation of Br− ions is observed. This is accompanied by a partial transformation of BrU into U. The observed damage is at least partly ascribed to the intermediate formation of lowenergy electrons from the laser-excited AuNPs and subsequent dissociative electron attachment to T, U, and BrU. These reactions represent basic DNA damage pathways occurring on the one hand in plasmon-assisted cancer therapy and on the other hand in conventional cancer radiation therapy using AuNPs as sensitizing agents. KW - Gold nanoparticles KW - SERS KW - Electrons KW - DNA damage KW - Gold-Nanopartikel KW - Elektronen KW - DNA-Schädigung PY - 2016 DO - https://doi.org/10.1021/acs.jpcc.5b10564 VL - 120 IS - 5 SP - 3001 EP - 3009 PB - AMER CHEMICAL SOC AN - OPUS4-35673 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Bachmann, Marcel A1 - Kunze, R. A1 - Avilov, Vjaceslav A1 - Rethmeier, Michael T1 - Finite element modeling of an alternating current electromagnetic weld pool support in full penetration laser beam welding of thick duplex stainless steel plates N2 - An electromagnetic weld pool support system for 20 mm thick duplex stainless steel AISI 2205 was investigated numerically and compared to experiments. In our former publications, it was shown how an alternating current (AC) magnetic field below the process zone directed perpendicular to the welding direction can induce vertically directed Lorentz forces. These can counteract the gravitational forces and allow for a suppression of material drop-out for austenitic stainless steels and aluminum alloys. In this investigation, we additionally adopted a steady-state complex magnetic permeability model for the consideration of the magnetic hysteresis behavior due to the ferritic characteristics of the material. The model was calibrated against the Jiles–Atherton model. The material model was also successfully tested against an experimental configuration before welding with a 30 mm diameter cylinder of austenitic stainless steel sur-rounded by duplex stainless steel. Thereby, the effects of the Curie temperature on the magnetic characteristics in the vicinity of the later welding zone were simulated. The welding process was modeled with a three-dimensional turbulent steady-state model including heat transfer and fluid dy-namics as well as the electromagnetic field equations. Main physical effects, the thermo-capillary (Marangoni) convection at the weld pool boundaries, the natural convection due to gravity as well as latent heat of solid–liquid phase transitions at the phase boundaries were accounted for in the model. The feedback of the electromagnetic forces on the weld pool was described in terms of the electromagnetic-induced pressure. The finite element software COMSOL Multiphysics 4.2 was used in this investigation. It is shown that the gravity drop-out associated with the welding of 20 mm thick duplex stainless steel plates due to the hydrostatic pressure can be prevented by the application of AC magnetic fields between around 70 and 90 mT. The corresponding oscillation frequencies were between 1 and 10 kHz and the electromagnetic AC powers were between 1 and 2.3 kW. In the experiments, values of the electromagnetic AC power between 1.6 and 2.4 kW at os-cillation frequencies between 1.2 and 2.5 kHz were found to be optimal to avoid melt sagging or drop-out of melt in single pass full-penetration laser beam welding of 15 and 20 mm thick AISI 2205. KW - Laser KW - Numerical simulation KW - Laser beam welding KW - Electromagnetic weld pool support KW - Duplex stainless steel PY - 2016 DO - https://doi.org/10.2351/1.4943906 VL - 28 IS - 2 SP - 022404-1 EP - 022404-9 PB - AIP Publishing AN - OPUS4-35676 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Konersmann, Rainer T1 - Überdeckungshöhen von Pipelines - Wie tief ist tief genug? N2 - Ein wesentliches Grundbedürfnis ist die Sicherheit, d. h. die Gewissheit, in einer sicheren Umgebung zu leben und zu arbeiten. Die existenzielle Sicherheit ist eine notwendige Voraussetzung zur Befriedigung aller weiteren notwendigen Bedürfnisse. Auch die Technik ist ohne Sicherheit nicht denkbar. Trotz aller Bemühungen kommt es aber immer wieder zu Unfällen, aus welchen Gründen auch immer. Eine Strategie, Unfälle zu verhindern bzw. deren Eintrittswahrscheinlichkeit zu minimieren ist es, zwischen einem Objekt mit einem hohen Gefährdungspotenzial und seiner Nachbarschaft, Barrieren zu errichten, z. B. durch eine schützende Isolierung, Sicherheitsabstände oder durch eine Erdüberdeckung. Die erdgedeckte Verlegung von Pipelines ist Stand der Technik. Über die Überdeckungshöhen scheint es jedoch verschiedene Auffassungen zu geben. Im folgenden Beitrag werden dazu einige Beispiele vorgestellt. KW - Rohrleitungen KW - optimale Überdeckungshöhe KW - Verkehrslasten PY - 2016 SN - 2191-0073 VL - 36 IS - 3 SP - 44 EP - 48 PB - Springer-VDI-Verl. CY - Düsseldorf AN - OPUS4-35681 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Petrov, Sergej A1 - Neumann, Patrick P. A1 - Werner, Klaus-Dieter A1 - Wosniok, Aleksander A1 - Lazik, D. A1 - Bartholmai, Matthias ED - Nicoletto, G. ED - Pastrama, S.D. ED - Emri, I. T1 - Concept for investigating mechanical and thermal 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 CO 2 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 CO 2 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 KW - Linear sensor KW - Distributed sensor KW - Monitoring of CO 2 KW - Subsurface monitoring KW - Gas storage areas KW - Membrane-based gas sensing KW - Fibre optical sensing PY - 2016 DO - https://doi.org/10.1016/j.matpr.2016.03.060 SN - 2214-7853 VL - 3 IS - 4 SP - 1124 EP - 1128 PB - Elsevier Ltd. AN - OPUS4-35688 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Babutzka, Martin A1 - Heyn, A. ED - Lampke, T. ED - Wagner, G. ED - Wagner, M.F.-X. T1 - Korrosionsuntersuchungen mit gelartigen Elektrolyten N2 - Bei elektrochemischen Untersuchungen von atmosphärischen Korrosionsreaktionen an deckschicht- und passivschichtbildenden Werkstoffen stößt man elektrolytseitig an Grenzen. So erweisen sich sowohl das Nachempfinden eines dünnen Feuchtfilms als auch die Interpretation von elektrochemischen Messungen in so genannten Bulk-Lösungen (eine „Masse“ an Elektrolyt) hinsichtlich des Korrosionsverhaltens unter atmosphärischen Bedingungen häufig als schwierig. Eine neue Herangehensweise an diese Problemstellung in der Korrosionsforschung beinhaltet den Einsatz von gelartigen Elektrolyten als Alternative zu den Bulk-Elektrolyten. Gelartige Elektrolyte bilden einen dünnen Feuchtfilm auf der Werkstoffoberfläche aus, wodurch die natürlich gebildete Deckschicht ähnlich wie an Atmosphäre beeinflusst wird und nahezu zerstörungsfrei untersucht werden kann. Durch eine elektrochemische Instrumentierung können geeignete Kennwerte wie Polarisationswiderstände und Korrosionsströme ermittelt werden, die Aussagen zur Kinetik der Deckschichtbildung und zur Stabilität der gebildeten Deckschichten unter Einwirkung eines dünnen Feuchtfilms ermöglichen. Anhand von auf Polysaccharid basierenden Gelpads werden im vorliegenden Beitrag verschiedene Zinkschichtsysteme und Aluminiumlegierungen untersucht, die natürlich gebildeten Deckschichten elektrochemisch charakterisiert und korrosionsrelevante Kennwerte bestimmt. Die ermittelten Kennwerte erlauben eine Differenzierung verschiedener Schichtsysteme und beschreiben die momentane Schutzwirkung der Deckschichten unter atmosphärischen Bedingungen. T2 - 18. Werkstofftechnisches Kolloquium der TU Chemnitz CY - Chemnitz, Germany DA - 10.03.2016 KW - Korrosionsuntersuchungen KW - Corrosion investigations KW - Verzinkungen KW - Zing coatings KW - gelartige Elektrolyte KW - Gel-type electrolytes PY - 2016 SN - 978-3-00-052212-3 SN - 1439-1597 VL - 59 SP - 313 EP - 323 PB - TU Chemnitz, Fakultät für Maschinenbau, Institut für Werkstoffwissenschaft und Werkstofftechnik CY - Chemnitz AN - OPUS4-35637 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Woydt, Mathias T1 - Tailoring the functional properties of niobium carbide N2 - Several phases, like Nb₄C₃, Nb₆C₅ and other short and long range ordered phases occur in the region of homogeneity of NbCₓ (0,75≤ x ≤1.0) in the binary phase diagram. Properties, like micro-hardness, hot hardness, sliding wear resistance, elastic modulus and toughness can be tailored by the C/Nb ratio, the addition of secondary carbides and the type of binder. Supporting results from different grades with varying C/Nb ratio or binder types were illuminated. Thus, the NbC system offers to producers a wider process window, than WC. The impact of These tailored properties on sliding wear and cutting performance was illuminated by tribological and machining results. Niobium is today largely available. NbC can be synthesized by carbothermal conversion of Nb₂O₅ or be metallurgically grown and leached out, provides comparably low friction in many relevant tribo-contacts and displays low wear. NbC and Nb₂O₅ have so far no REACH classification related to human toxicology and are not listed as substances of very high concern contrary to WO₃ and Co₃O₄. T2 - 40th International Conference and Exposition on Advanced Ceramics and Composites CY - Daytona Beach, FL, USA DA - 24.01.2016 KW - Niobium carbide KW - Hard metal KW - Wear KW - Friction KW - Machining KW - Cutting KW - Metal matrix composite PY - 2016 SP - Paper: 2347292, 1 EP - 13 AN - OPUS4-35640 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Simon, Franz-Georg A1 - Holm, Olaf T1 - Exergetic considerations on the recovery of metals from waste N2 - Bottom ash from municipal solid waste incineration (MSWI) consists of elemental metals in considerable amounts. The exergy of bottom ash was calculated to be some 100 kJ/mol, mainly as a result of the presence of elemental Fe and Al. From this it can be shown that the recovery of elemental metals Cu, Al and Fe is beneficial. The fine fraction <4 mm additionally contains chemically bound metals (oxides, carbonates, silicates). Separation prospects with techniques as in ore processing (flotation, density separation, bioleaching, hydrothermal solution) are discussed. Although the concentration of Cu compounds in bottom ash is in the range of today’s exploited ores the economic viability of the recovery of metal compounds is uncertain. For sufficient enrichment different concerted treatment steps are required. KW - bioleaching KW - bottom ash KW - cumulative energy consumption KW - cumulative exergy consumption KW - density separation KW - environmental technology KW - exergy KW - flotation KW - recycling technology KW - recovery KW - waste management PY - 2016 UR - http://www.inderscience.com/info/inarticletoc.php?jcode=ijex&year=2016&vol=19&issue=3 DO - https://doi.org/10.1504/IJEX.2016.075668 SN - 1742-8300 SN - 1742-8297 VL - 19 IS - 3 SP - 352 EP - 363 PB - Inderscience Enterprises Ltd. CY - Olney, UK AN - OPUS4-35646 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Maiwald, Michael T1 - Clever und Smart - Die neuen Prozess-Sensoren 4.0 N2 - Die gravierenden Veränderungen im Umfeld der Informations- und Kommunikationstechnik beeinflussen auch die Prozessautomation und sind zugleich eine Chance. Denn die Automatisierungskonzepte gemäß Industrie 4.0 sichern den Wettbewerbsvorteil einer Volkswirtschaft. Ein zentrales Element bilden dabei smarte Sensoren, die Dienste innerhalb eines Netzwerks bereitstellen und Information daraus nutzen. Die im November 2015 vorgestellte Technologieroadmap Prozess-Sensoren 4.0 [1] zeigt Anforderungen an smarte Prozess-Sensoren auf. Der Beitrag befasst sich mit den Fragen „Was kann der Prozess-Sensor zu Industrie 4.0 beitragen?“ und „Welchen Nutzen bringt Industrie 4.0 für den Prozess-Sensor?“ KW - Technologieroadmap KW - Prozess-Sensoren 4.0 KW - Industrie 4.0 KW - Prozessanalytik PY - 2016 SN - 0178-2320 VL - 58 IS - 3 SP - 28 EP - 35 PB - DIV Deutscher Industrieverlag CY - München AN - OPUS4-35717 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Javdanitehran, M. A1 - Berg, D. Ch. A1 - Dümichen, Erik A1 - Ziegmann, G. ED - Javdanitehran, M. T1 - An iterative approach for isothermal curing kinetics modelling of an epoxy resin system N2 - In this work a novel iterative method for isothermal cure kinetic modelling of an epoxy resin system using differential scanning calorimetry (DSC) technique is presented. To reach the isothermal cure temperature, the sample has to be heated up from ambient temperature. This is commonly done with very high heat-up rates to minimise the time the sample reacts at temperatures other than the desired one. However, during heat up with high heating the amount of released energy rates cannot be measured directly because the shape of baseline is unknown. This means that the cure state at the beginning of the isothermal stage is unknown. For fast curing systems this unknown cure state causes significant inaccuracies in cure kinetics modelling. The presented iterative approach attempts to estimate the released enthalpy during heat-up of an isothermal run through an iterative numerical modelling of the heat-up phase. In each iteration the algorithm starts by estimating the enthalpy released during heat-up based on the recorded temperature profile and the calibrated model of the previous iteration. At the same time, it estimates the degree of cure at the end of the heat-up phase. Once the initial cure state is known the total heat of enthalpy can be recalculated for the current iteration. Subsequently the degree of cure and curing rate are re-evaluated with the newly estimated total enthalpy and used for determining the kinetics parameters. This is done by simultaneous fitting of the selected model to all experimental heat flow curves using a non-linear nonrestricted multivariable fitting method. The model with these new parameters is used again to estimate the released enthalpy and cure degree during the heat-up phase. The described loop is repeated until a predefined convergence criterion is satisfied. For modelling the reaction kinetics, the Kamal–Sourour equation accompanied with Rabinowitch approach to consider the diffusion effects is used. The diffusion reaction rate is modelled by the free volume model proposed by Huguenin and Klein. DiBenedetto model is applied to predict the Evolution of glass transition temperature against the degree of cure. In order to compensate the effect of the Initial values in the model’s calibration, the algorithm is implemented in a routine, which assesses the quality of the fitting and consequently selects the cure kinetics parameter. The described algorithm and the Routine are implemented in MATLAB. This paper demonstrates the application of this approach for using cure kinetics modelling to predict the degree of cure and the glass transition temperature. It supports the obtained results with validation tests using isothermal, dynamic and combined temperature profiles. KW - Epoxy resins KW - Curing kinetics KW - DSC KW - Isothermal PY - 2016 DO - https://doi.org/10.1016/j.tca.2015.11.014 VL - 2016 IS - 623 SP - 72 EP - 79 PB - Elsevier B.V. AN - OPUS4-35719 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Ortel, Erik A1 - Bernicke, M. A1 - Eckhardt, B. A1 - Bernsmeier, D. A1 - Schmack, R. A1 - Kraehnert, R. A1 - Lippitz, Andreas T1 - Synthesis and OER activity of NiO coatings with N2 - Catalysts based on nickel oxide are some of the most active catalysts for the oxygen evolution reaction (OER) in alkaline media. However, preparing catalytic coatings with high surface area and good accessibility of the active sites remains challenging. We present a new approach for the synthesis of homogeneous and binder-free nickel oxide coatings comprising a highly accessible ordered mesopore structure. The synthesis is achieved via evaporation induced self assembly utilizing PEOPB-PEO triblock copolymers as pore template and a chemical complex of Ni2+ and citric acid as precursor. Excessive crystallization behaviour of NiO is avoided by thermal conversion of the precursor into an amorphous Ni carbonate intermediate, followed by transition of the carbonate into the metal oxide. We present a comprehensive analysis of the obtained materials in terms of morphology, crystallinity, surface area, composition, and OER activity of differently calcined catalysts. Retaining a low crystallinity and high surface area during the Synthesis proofs to be the most important factor in obtaining a highly active OER catalyst. KW - XPS KW - nanoparticle KW - catalysis PY - 2016 UR - http://onlinelibrary.wiley.com/doi/10.1002/slct.201600110/abstract DO - https://doi.org/10.1002/slct.201600110 VL - 2016 IS - 3/2016 SP - 482 EP - 489 PB - Wiley Online Library CY - Weinheim AN - OPUS4-35725 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Elordui-Zapatarietxe, S. A1 - Fettig, Ina A1 - Richter, Janine A1 - Philipp, Rosemarie A1 - Vanermen, G. A1 - Monteyne, E. A1 - Boom, G. A1 - Emteborg, H. T1 - Preparation and evaluation of sufficiently homogeneous and stable reference materials for priority hazardous substances in whole water N2 - We have prepared and evaluated three whole water test materials containing eight polycyclic aromatic hydrocarbons (PAHs), six polybrominated diphenyl ethers (PBDEs) and tributyltin (TBT) with respect to homogeneity and short-term stability. The test materials were used as samples in two inter-laboratory comparisons. The materials were composed of natural mineral water and model suspended particulate matter (SPM) containing the target compounds at ng L-1 levels. The expanded uncertainty of the estimated mass concentrations in the final test materials was obtained by combining contributions from the homogeneity, the stability and the model SPM characterization. The whole water materials were sufficiently homogeneous and stable at 4 °C for their intended use. In total, 12 out of 15 investigated target parameters could be assessed to be present with a relative combined expanded uncertainty below 25 %. The outcome of the two interlaboratory comparisons confirmed the good quality of the test materials and the level of uncertainties associated with the estimated mass concentrations. These findings are an important contribution towards the development of whole water matrix reference materials certified for PAH, PBDE and TBT in support of the Water Framework Directive of the European Union. KW - Reference material KW - Referenzmaterial KW - Water Framework Directive KW - Wasserrahmenrichtlinie KW - Whole water sample KW - Gesamtwasserprobe PY - 2016 DO - https://doi.org/10.1007/s00769-015-1189-1 SN - 0949-1775 SN - 1432-0517 VL - 21 IS - 2 SP - 113 EP - 120 PB - Springer AN - OPUS4-35728 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Richter, Janine A1 - Elordui-Zapatarietxe, S. A1 - Emteborg, H. A1 - Fettig, Ina A1 - Cabillic, J. A1 - Alasonati, E. A1 - Gantois, F. A1 - Swart, C. A1 - Gokcen, T. A1 - Tunc, M. A1 - Binici, B. A1 - Rodriguez-Cea, A. A1 - Zuliani, T. A1 - Gonzalez Gago, A. A1 - Pröfrock, D. A1 - Nousiainen, M. A1 - Sawal, G. A1 - Buzoianu, M. A1 - Philipp, Rosemarie T1 - An interlaboratory comparison on whole water samples N2 - The European Water Framework Directive 2000/60/EC requires monitoring of organic priority pollutants in so-called whole water samples, i.e. in aqueous nonfiltered samples that contain natural colloidal and suspended particulate matter. Colloids and suspended particles in the liquid phase constitute a challenge for sample homogeneity and stability. Within the joint research project ENV08 ‘‘Traceable measurements for monitoring critical pollutants under the European Water Framework Directive 2000/60/EC’’, whole water test materials were developed by spiking defined amounts of aqueous slurries of ultrafinely milled contaminated soil or sediment and aqueous solutions of humic acid into a natural mineral water matrix. This paper presents the results of an European-wide interlaboratory comparison (ILC) using this type of test materials. Target analytes were tributyltin, polybrominated diphenyl ethers and polycyclic aromatic hydrocarbons in the ng/L concentration range. Results of the ILC indicate that the produced materials are sufficiently homogeneous and stable to serve as samples for, e.g. proficiency testing or method validation. To our knowledge, this is the first time that ready-to-use water materials with a defined amount of suspended particulate and colloidal matter have been applied as test samples in an interlaboratory exercise. These samples meet the requirements of the European Water Framework Directive. Previous proficiency testing schemes mainly employed filtered water samples fortified with a spike of the target analyte in a water-miscible organic solvent. KW - Water Framework Directive KW - Wasserrahmenrichtlinie KW - Interlaboratory comparison KW - Ringversuch KW - Whole water sample KW - Gesamtwasserprobe PY - 2016 DO - https://doi.org/10.1007/s00769-015-1190-8 SN - 0949-1775 SN - 1432-0517 VL - 21 IS - 2 SP - 121 EP - 129 PB - Springer AN - OPUS4-35730 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Fischer, Franziska A1 - Schmidt, M. U. A1 - Greiser, Sebastian A1 - Emmerling, Franziska T1 - The challenging case of the theophylline–benzamide cocrystal N2 - Theophylline has been used as an active pharmaceutical ingredient (API) in the treatment of pulmonary diseases, but due to its low water solubility reveals very poor bioavailability. Based on its different hydrogen-bond donor and acceptor groups, theophylline is an ideal candidate for the formation of cocrystals. The crystal structure of the 1:1 benzamide cocrystal of theophylline, C7H8N4O2·-C7H7NO, was determined from synchrotron X-ray powder diffraction data. The compound crystallizes in the tetragonal space group P41 with four Independent molecules in the asymmetric unit. The molecules form a hunter’s fence packing. The crystal structure was confirmed by dispersion-corrected DFT calculations. The possibility of salt formation was excluded by the results of Raman and 1H solid-state NMR spectroscopic analyses. KW - powder diffraction KW - theophylline KW - benzamide KW - cocrystal KW - crystal structure KW - active pharmaceutical ingredient KW - dispersion-corrected density-functional theory PY - 2016 DO - https://doi.org/10.1107/S2053229616002643 SN - 2053-2296 VL - 72 IS - 3 SP - 217 EP - 224 AN - OPUS4-35621 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Hoesl, Simone A1 - Neumann, B. A1 - Techritz, Sandra A1 - Sauter, G. A1 - Simon, R. A1 - Schlüter, H. A1 - Linscheid, M. W. A1 - Theruing, F. A1 - Müller, Larissa A1 - Jakubowski, Norbert T1 - Internal standardization of LA-ICP-MS immunoimaging via printing of universal metal spiked inks onto tissue sections N2 - Formalin-fixed paraffin-embedded (FFPE) specimen from biopsy materials are a widespread sample format for pathologists and medical researchers. Pathologists are archiving vast numbers of FFPE samples which can be stored for decades. Conventional immunohistochemical staining (IHC) of biomarkers on FFPE tissue sections is one of the most important analytical techniques for cancer diagnosis and pathology in general. However standardization for IHC samples and quality management is tedious and differs significantly from clinic to clinic. Combining established IHC staining strategies with modern mass spectrometry mediated methods would increase it`s potential and enable access of large FFPE archives for multiplexed quantitation purposes. In this work element mass spectrometry and a new ink-jet printed internal standardization approach was successfully combined with IHC staining to facilitate quantitative multiplex assays for archived FFPE samples. The printing strategy improves elemental image resolution and reproducibility of paraffin embedded breast cancer tissue sections in laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) using conventional IHC staining as a model system to investigate the new capabilities of this technique. For the internal standardization we applied a conventional CD-ink-jet printer to print a metal spiked ink onto the top of thin layer tissue sections with constant density. Printing was carried out in a direct comparison to an iodination of the tissue section as previously described as an alternative standardization method. The use of the printed internal standard allowed correction of the fluctuation during the laser ablation process and compensated instrumental drift effects. Mediated by the ink correction approach we achieved better signal-to-background-ratios (SBR) of 74 and better spatial resolution of 30 µm compared to iodination (SBR=23). This improved performance was demonstrated on tumorous areas in FFPE breast cancer tissue sections and allowing detection of Her-2 in tumorous areas of this tissue with significantly improved contrast. KW - Internal standardization KW - LA-ICP-MS KW - Immuno imaging PY - 2016 DO - https://doi.org/10.1039/c5ja00409h SN - 0267-9477 SN - 1364-5544 VL - 31 IS - 3 SP - 801 EP - 808 AN - OPUS4-35711 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Weltschev, Margit A1 - Werner, Jan A1 - Heming, Frank A1 - Jochems, Frank T1 - Impact of biocomponents in the fuel and heating oil on the compatibility of sealing materials N2 - The objective of this research was to determine the resistance of frequently used sealing materials such as FKM, FVMQ, VMQ, EPDM, CR, CSM, IIR, PA, NBR and PUR in fuels and heating oil with and without admixtures of biogenic sources such as E10, diesel fuel with 5 % biodiesel, non-aged and 2 year aged B10 (heating oil with 10 % biodiesel), pure diesel, standard heating oil and premium grade fuel Super plus at 20 °C, 40 °C and 70 °C. Mass, tensile strength and breaking elongation of the test specimens were determined before and after the exposure for 84 days in the fuels. The visual examination of some elastomer test specimens clearly showed the great volume increase until break or partial dissolution. Shore hardness A and D (for PA) were determined before and after exposure of the test specimens in the biofuels for 42 days. There is not determined a threshold for the reduction in tensile properties and Shore hardness in the international standards. Therefore a threshold of 15 % was determined for the evaluation of the compatibility. In summary, it can be therefore stated that the chemical resistance of the fluoropolymers FKM and FVMQ in fuels and biofuels is the best one. T2 - CORROSION 2016 CY - Vancouver, Kanada DA - 06.03.2016 KW - sealing materials KW - compatibility KW - biofuels PY - 2016 SP - Paper No. 7307, 1 EP - 12 PB - NACE INTERNATIONAL, Publications Division CY - Houston, Texas 77084 (USA) AN - OPUS4-35622 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Wu, Cheng-Chieh A1 - Weisbrich, S. A1 - Neitzel, F. ED - Nicoletto, G. ED - Pastrama, S. D. ED - Emri, I. T1 - Inverse finite element adjustment of material parameters from integrated analysis of displacement field measurement N2 - The determination of material parameters from displacement field measurement is being examined for linear elastic solid. A frequently used approach to compute material constants can be found in many studies. Even though they presented the approach in many different variations, but in the end they are essentially based on the same algorithm: Parameters are iteratively tuned until the computed results are in accordance with the measurements. The main drawback of this approach is that mainly commercial software is used that hinders us to investigate its inner evaluation process. This leads to the question, how the results from this commercial software can be trusted. On the contrary to these debatable approaches, we present a method that inverts the procedure of finite element method by using the most general model for a least-squares adjustment – the GAUSS-HELMERT Model. T2 - 32nd DANUBIA ADRIA SYMPOSIUM on Advances in Experimental Mechanics CY - Starý Smokovec, Slovakia DA - 22.09.2015 KW - Integrated analysis KW - Inverse problem KW - Finite element method KW - Least-squares adjustment KW - Model and measurement based analysis PY - 2016 UR - http://www.sciencedirect.com/science/article/pii/S2214785316002091 DO - https://doi.org/10.1016/j.matpr.2016.03.004 SN - 2214-7853 VL - 3 IS - 4 SP - 1211 EP - 1215 PB - Elsevier Ltd. AN - OPUS4-35629 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Neumann, Patrick P. A1 - Ebert, S. A1 - Lazik, D. A1 - Bartholmai, Matthias ED - Nicoletto, G. ED - Dan Pastrama, S. ED - Emri, I. 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 m² 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 KW - Linear sensor KW - Distributed sensor KW - Subsurface monitoring KW - Gas storage areas KW - Membrane-based gas sensing KW - Calibration PY - 2016 UR - http://www.sciencedirect.com/science/article/pii/S221478531600256X DO - https://doi.org/doi:10.1016/j.matpr.2016.03.051 SN - 2214-7853 VL - 3 IS - 4 SP - 1074 EP - 1078 PB - Elsevier Ltd. AN - OPUS4-35633 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Cappella, Brunero A1 - Wassenberg, J. R. A1 - Heim, L.-O. A1 - Klostermann, M. A1 - Venzmer, J. A1 - Bonaccurso, E. T1 - Mechanical properties of silicone methacrylate microparticles determined by AFM colloidal probe technique N2 - The mechanical properties of seven types of silicone methacrylate microparticles prepared by solution polymerization with a Pickering emulsifier were investigated by Atomic Force Microscope force–displacement curves acquired in air with the Colloidal Probe Technique, i.e., with spherical SiO2 particles of known radius glued on tipless cantilevers. The deformation curves derived from the force–displacement curves were fitted with Hertz equation for the contact between two spherical particles, which lead to the determination of the elastic modulus of the samples. The performed measurements and the analysis provide quite exact values of the elastic modulus of all investigated polymer particles. Moreover, the results of the measurements were repeatable over large time intervals, also with different experimental setups. The influence of the sample preparation (polymerization method, cross-linking density of the polymer, and thickness of the external shell of the Pickering emulsifier) is discussed as well. The elastic moduli correlate with the cross-linking density (from 2 MPa for low cross-linking density up to 100–130 MPa for medium cross-linking density), whereas the thickness of the external shell formed by the Pickering emulsifier has no measurable influence on the mechanical properties of the microparticles. KW - Colloidal probe technique KW - Hertz model KW - Silicone elastomer PY - 2014 DO - https://doi.org/10.1016/j.polymer.2014.01.021 SN - 0032-3861 SN - 1873-2291 VL - 55 IS - 5 SP - 1209 EP - 1216 PB - Elsevier Ltd. AN - OPUS4-30316 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Würsig, Andreas A1 - Jochems, Frank T1 - Rundum genormt - Wanddicke - Die Drucktanknorm wurde auf UN Tanks erweitert, und damit ein einheitlicher europäischer Berechnungscode für Gefahrguttanks entwickelt N2 - Tanks für gefährliche Güter nach Kapitel 6.8 RID/ADR müssen gemäß den in den Gefahrgutvorschriften zitierten Normen entworfen und gebaut werden. Abweichungen von den Normen sind nur möglich, um dem wissenschaftlichen und technischen Fortschritt Rechnung zu tragen, oder in Fällen, in denen die Normen bestimmte Bereiche nicht abdecken. In diesen Sonderfällen kann die zuständige Behörde ein technisches Regelwerk anerkennen, wobei die Tanks mindestens ein gleiches Sicherheitsniveau aufweisen müssen und die Mindestanforderungen aus Kapitel 6.8 RID/ADR eingehalten sind. KW - Gefahrguttanks KW - Tankberechnung KW - UN Tanks PY - 2014 SN - 0944-6117 VL - 3 SP - 12 EP - 14 PB - Vogel CY - München AN - OPUS4-30320 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -