TY - CONF A1 - Kupsch, Andreas A1 - Lange, Axel A1 - Hentschel, Manfred P. A1 - Jaenisch, Gerd-Rüdiger A1 - Kardjilov, N. A1 - Tötzke, C. A1 - Markötter, H. A1 - Hilger, A. A1 - Manke, I. T1 - Compton-CT als Alternative zur Neutronentomographie? N2 - Als Alternative zur Neutronentomographie wird das Potenzial der Computertomographie (CT) mit inkohärenter Röntgen-Streustrahlung (Compton-Streuung) untersucht. Die gleichzeitige Abbildung von Materialien sehr unterschiedlicher Dichten (Ordnungszahlen) ist eine wiederkehrende Herausforderung für die Radiologie und die Computertomographie mit Röntgenstrahlung. Die Messungen ergeben asymmetrische Projektionsprofile für Sinogramme der Streuintensität. Am Beispiel verschiedener Polymere (Polyethylen, Polyamid, PVC), Glas und Holz wird in den Tomogrammen ein hochaufgelöster 'Comptonkontrast' vergleichbarer Dynamik erreicht, während der simultan gemessene 'Absorptionskontrast' ausschließlich die starken Absorber (Glas und PVC) zeigt. Der Vergleich mit ähnlich auflösender Neutronentomographie zeigt ähnliche Kontraste und eröffnet mithin die Möglichkeit, diese künftig durch Compton-Tomographie im Labormaßstab zu ersetzen. T2 - DACH-Jahrestagung 2015 CY - Salzburg, Austria DA - 11.05.2015 KW - Comptonstreuung KW - Computertomographie KW - Neutronentomographie PY - 2015 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-342894 SN - 978-3-940283-68-9 IS - DGZfP BB 152 SP - Mo.3.A.2, 1 EP - 10 AN - OPUS4-34289 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Wiggenhauser, Herbert A1 - Samokrutov, A.A. A1 - Mayer, K. A1 - Krause, Martin A1 - Alekhin, S. G. A1 - Elkin, V. T1 - LAUS - Large aperture ultrasonic system - for testing thick concrete structures N2 - A Large Aperture UltraSonic (LAUS) system has been designed and built for testing thick concrete structures. The scalable system consists of twelve ultrasonic units, each hosting 32 individual shear wave transducers with mechanical dry point contact (DPC) to the concrete surface. The twelve units are attached to the concrete surface using a vacuum case which holds them in place during operation. Each LAUS unit can be placed individually depending on the surface condition and optimal ultrasonic condition, e.g. rebar position. Air pressure is supplied to each unit through an air hose. The following extended abstract is a short version of an article to be published in the special edition of ASCE JIS that will describe the outline of the system, the principle of functioning, the data processing and adapted reconstruction calculation based on SAFT as well as the system performance during first applications. T2 - NDT-CE 2015 - International symposium non-destructive testing in civil engineering CY - Berlin, Germany DA - 15.09.2015 KW - Ultrasonic imaging KW - Linear array KW - Reconstruction calculation (SAFT) PY - 2015 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-345383 UR - http://www.ndt.net/?id=18313 SN - 1435-4934 VL - 20 IS - 11 SP - 1 EP - 4 PB - NDT.net CY - Kirchwald AN - OPUS4-34538 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hosseini, Seyed M. H. A1 - Heckel, Thomas A1 - Boehm, Rainer A1 - Brackrock, Daniel A1 - Gohlke, Dirk A1 - Riemer, Stefanie A1 - Gaal, Mate T1 - Gegenüberstellung der Performance verschiedener Ultraschallsensorsysteme bei der Untersuchung von CFK-Platten T1 - Comparison of performance of different ultrasonic systems for inspection of CFRP plates N2 - Die Zahl der industriellen Anwendungen mit Einsatz von Faserverbundwerkstoffen wächst kontinuierlich vor allem wegen der exzellenten Materialeigenschaften und des geringen Gewichtes dieses Werkstoffes. Entsprechend steigen die Anforderungen an zerstörungsfreie Prüfsysteme zur Gewährleistung des sicheren Betriebes von Komponenten und Strukturen bestehend aus Verbundwerkstoffen. Im Rahmen des EU-Projekes VITCEA (Validated Inspection Techniques for Composites in Energy Applications) wird das Ziel verfolgt, neue Prüfverfahren für moderne Verbundwerkstoffe zu entwickeln und zu validieren. Im Vordergrund steht hierbei als Applikation im Industriesektor Energieversorgung die Prüfung von sicherheitsrelevanten Komponenten von onshore und offshore Windkraftanlagen, wie z.B. deren Rotorblätter und tragende Strukturen. Eine Teilaufgabe innerhalb des Projektes stellen der Vergleich und die Validierung verschiedener Ultraschallprüfmethoden bezüglich ihrer Fähigkeit zum Nachweis der typischen Herstellungs- und betriebsbedingten Materialschädigungen von CFK und GFK dar. Neben verschiedenen konventionellen Ultraschall-Prüftechniken, werden die Phased-Array-Prüfung, insbesondere die Prüfung mit Matrixarrays, sowie die Untersuchung mit berührüngsloser Luftultraschalltechnik bezüglich ihrer Nachweisgrenzen und der Möglichkeiten zur Fehlercharakterisierung an Faserverbundwerkstoffen untersucht. Die Ergebnisse werden mit Untersuchungen mit thermographischen Methoden und Mikrowellentechnik verglichen. N2 - Applications of fiber-reinforced plastic (FRP) composites in modern industries are increasing due to their considerable advantages such as light weight and excellent mechanical properties. Accordingly, importance of operational safety of modern structures made of advanced composites by ensuring the material quality has led to increasing demands for development of non-destructive evaluation (NDE) systems. In the context of a European-project entitled 'Validated Inspection Techniques for Composites in Energy Applications' (VITCEA), the aim is to develop and validate traceable procedures for novel NDE techniques with contrasting damage detection capabilities in energy related applications such as wind and marine turbine blades, nacelles, oil and gas flexible risers. As a part of VITCEA, the present study focuses on application of ultrasonic tests (UTs) including conventional, matrix array, immersion and air-coupled, for quantitative defect detection and quality characterization of FRP structures. Results of UTs are subjected to be compared with other NDE approaches which are applicable for inspection of FRPs such as thermography and microwave techniques. Within the present report, the initial results obtained from conventional and immersion UTs are presented and their capabilities as well as limitations are discussed. In order to validate theoretical predictions and simulation results, further experimental tests will be performed in the framework of the project using reference defect artefacts in which the defect sizes and locations are well defined and controlled. T2 - DGZfP Seminar des Fachausschusses Ultraschallprüfung CY - Saarbrücken, Germany DA - 03.11.2015 KW - Ultraschallsensorsysteme KW - Faserverbundwerkstoffe KW - Kontakttechnik Technik KW - Tauchtechnik KW - Phased-Array-Prüfung KW - Luftultraschall PY - 2015 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-349264 UR - https://www.dgzfp.de/Portals/ultraschall2015/BB/3.pdf SP - Vortrag 3, 1 EP - 10 PB - Deutsche Gesellschaft für Zerstörungsfreie Prüfung (DGZfP) AN - OPUS4-34926 LA - mul AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Osterloh, Kurt A1 - Bellon, Carsten A1 - Hohendorf, Stefan A1 - Kolkoori, Sanjeevareddy A1 - Wrobel, Norma A1 - Nusser, A. A1 - Freitag, M. A1 - Bücherl, T. A1 - Bar, D. A1 - Mor, I. A1 - Tamin, N. A1 - Weiss-Babai, R. A1 - Bromberger, B. A1 - Dangendorf, V. A1 - Tittelmeier, K. T1 - Computed tomography with X-rays and fast neutrons for restoration of wooden artwork N2 - The objects of this investigation were sculptures taken from a ca. three hundred years old baroque epitaph of a church in Tonning, a town in Northern Germany. Around 1900 it was found in a disastrous state heavily damaged by wood-worm. At that time, the whole artwork was treated with the tar extract carbolineum as a remedy. Nowadays, this substance has been identified as carcinogenic, and its presence can be perceived by its stench and visually at certain spots on the surface where it has penetrated the covering paint. A gold-painted sculpture of a massive wooden skull was interrogated with X-rays and fast neutrons to investigate the internal distribution of the carbolineum. The X-ray tomography, with its excellent spatial resolution revealed galleries left over from the worm infestation in the outer areas and cracks in the central region. The golden color coating appeared as a thick and dense layer. In comparison the tomography with fast neutrons, though being of lower resolution and yet unresolved artefacts revealed sections of slightly different densities in the bulk of the wood. These differences we attribute to the differences in the distribution of the impregnant in the wood, visible due to its higher hydrogen content making it less transparent for neutrons. T2 - WCNR-10 - 10th World conference on neutron radiography CY - Grindelwald, Switzerland DA - 05.10.2014 KW - Computed tomography KW - Neutron radiology KW - Conservation of wooden artwork PY - 2015 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-323050 DO - https://doi.org/10.1016/j.phpro.2015.07.066 SN - 1875-3892 VL - 69 SP - 472 EP - 477 PB - Elsevier B.V. CY - Amsterdam AN - OPUS4-32305 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Mishra, Kirti Bhushan A1 - Wehrstedt, Klaus-Dieter A1 - Krebs, Holger T1 - Boiling liquid expanding vapour explosion (BLEVE) of peroxy-fuels: Experiments and computational fluid dynamics (CFD) simulation N2 - Fire and explosion hazards associated with storage and transportation of flammable materials have been a matter of great interest in the recent times. BLEVE is a scenario that occurs when a closed fuel container is subjected to heat for a longer duration. Such events are disastrous to human beings and assets both. In the past there have been numerous studies on BLEVEs and fireballs of hydrocarbon fuels, e.g. kerosene, gasoline, LPG, LNG and others. Though, the fireballs of peroxy-fuels are not looked into detail as such. This article tries to overcome this lack of knowledge. Both, experimental investigation and CFD simulations are performed to measure and predict the fireball characteristics of a peroxy-fuel. Due to thermal decomposition in the liquid phase and active oxygen content a peroxy-fuel fireball burns at a very fast rate and emit higher thermal radiation whereas exhibits smaller diameter and elevation compared to hydrocarbons. That eventually leads to consideration of larger safety distances from them which are also verified by CFD results. KW - BLEVE KW - Hydrocarbons KW - Peroxy-fuels KW - Safety distances KW - CFD simulation PY - 2015 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-334184 DO - https://doi.org/10.1016/j.egypro.2015.02.082 SN - 1876-6102 VL - 66 SP - 149 EP - 152 PB - Elsevier Ltd. CY - Amsterdam AN - OPUS4-33418 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kotschate, Daniel A1 - Gohlke, Dirk A1 - Heckel, Thomas T1 - Three dimensional examination of directivity pattern in immersion tank testing N2 - High resolution examination of safety-relevant parts in immersion tank testing with focussing probes is forming a main topic of modern non-destructive testing. For the usage of complex reconstruction methods and algorithms, an individual and detailed knowledge about the transmission behaviour of the used probes is essential, as this has a significant influence on the results of data reconstruction. Especially the knowledge about position and diameter of the focal point is needed to achieve the highest possible sensitivity. Through the individual position of the beam axis within the examined volume, a four dimensional metro logical determination of the acoustical pressure (x, y, z, t) is necessary. With the measured data it is possible to draw interferences about the sound field and acoustical pressure distribution. The presented work realized a method of automatic determination of the beam axis, the position of focal point and the focal diameter to support individual testing setups and transducer characterization. T2 - 7th International Symposium on NDT in Aerospace CY - Bremen, Germany DA - 16.11.2015 PY - 2015 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-339995 AN - OPUS4-33999 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Pohl, Rainer A1 - Commandeur, C. A1 - Erthner, Thomas A1 - Kreutzbruck, M. A1 - Pelkner, Matthias T1 - GMR-Streufluss-Prüfsystem zur Detektion verdeckter Fehler in Feinblechen N2 - BAM und TATA Steel untersuchen gemeinsam, ob sich die Prüfung von ferritischen Feinblechen mit einer Stärke von etwa 0,2 mm während der Fertigung durch den Einsatz von GMR-Sensorik verbessern lässt. Hierzu wurde eine Vorstudie an Feinblechen mit eingebrachten Mikronuten durchgeführt. Diese Nuten variieren in ihrer Tiefe zwischen 5 μm und 60 μm und wurden verdeckt mit ZfP-angepassten GMR-Sensorarrays geprüft. Die Ergebnisse der Vorstudie zeigten, dass bei verdeckter Prüfung schon kleinste Defekte mit einer Tiefe von 10 μm - gleichbedeutend mit einer Restwanddicke von 90 % – mit einem SNR > 6 dB detektiert werden konnten, wobei der Abstand der Prüfsonde zur Oberfläche bis zu 500 μm betrug. Zudem wurden in der Vorstudie Untersuchungen zur Prüfgeschwindigkeit und Praxistauglichkeit durchgeführt. Basierend auf den hier gewonnenen Ergebnissen wird ein erster Demonstrator für eine zuverlässige Prüfung eines Teilbereiches von 50 mm des Feinbleches innerhalb einer Produktionslinie aufgebaut. Zum Einsatz kommen Prüfsonden mit jeweils 24 GMR-Sensorelementen. Hierbei wird das Ziel einer umfassenden Prüfung des Feinblechs über die gesamte Breite von 1200 mm angestrebt. Eine besondere Herausforderung stellt dabei die hohe Anzahl von mehr als 1000 Sensorelementen dar. Das hierfür entwickelte Prüfkonzept umfasst neben einer angepassten Erzeugung des Magnetfeldes die Entwicklung einer geeigneten schnellen und sicheren Elektronik für die neuen Mehrkanalprüfköpfe. Neben der Vorstellung des Prüfkonzeptes und seiner Eigenschaften vergleichen wir die erzielten Prüfergebnisse an verschiedenen Vergleichsfehlern mit denen der Vorstudie. T2 - DACH-Jahrestagung 2015 CY - Salzburg, Austria DA - 11.05.2015 KW - Streuflussprüfung KW - GMR PY - 2015 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-343354 SN - 978-3-940283-68-9 IS - DGZfP BB 152 SP - Mi.2.B.3, 1 EP - 9 AN - OPUS4-34335 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Jonietz, Florian A1 - Ziegler, Mathias A1 - Myrach, Philipp A1 - Suwala, H. A1 - Rethmeier, Michael T1 - Untersuchung von Punktschweißverbindungen mit aktiver Thermografie N2 - Widerstandspunktschweißen ist insbesondere im Automobilbau eine der wichtigsten Fügetechniken. Bislang erfolgt die Qualitätssicherung überwiegend durch stichprobenartige zerstörende Prüfung. Eine zerstörungsfreie Prüftechnik würde neben der Reduzierung der Prüfkosten auch eine Optimierung des Punktschweißverfahrens bedeuten, da prinzipiell jeder Schweißpunkt geprüft werden könnte und somit auch eine Reduzierung der Anzahl der Schweißpunkte möglich ist. Es wird ein Verfahren vorgestellt, bei dem die Punktschweißverbindung zwischen zwei Stahlblechen optisch auf einer Blechseite mittels Laser oder Blitzlicht erwärmt wird. Die aufgeschmolzene Zone, die sogenannte Schweißlinse, stellt dabei neben der mechanischen Verbindung auch eine Wärmebrücke zwischen den beiden verschweißten Blechen dar, die bei diesem Verfahren ausgenutzt wird. Durch den verbesserten thermischen Kontakt zwischen den verschweißten Blechen an der Schweißlinse kontrastiert diese deutlich mit dem umgebenden Blechmaterial, bei dem der Wärmeübertrag zwischen den Blechen vergleichsweise gering ist. Dieser Kontrast im thermischen Verhalten kann mittels zeitabhängiger Thermografie gemessen werden. Durch das hier vorgestellte Verfahren kann mittels aktiver Thermografie sowohl in Transmissions- als auch in Reflexionsanordnung die Größe des thermischen Kontaktes zwischen den beiden Blechen ermittelt werden, welche ein Maß für die Größe der Schweißlinse und damit für die qualitative Güte der Schweißung darstellt. Ein Vorteil des entwickelten Verfahrens ist seine Anwendbarkeit auf Bleche ohne Oberflächenbehandlung. T2 - DACH-Jahrestagung 2015 CY - Salzburg, Austria DA - 11.05.2015 PY - 2015 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-343476 UR - http://www.ndt.net/?id=19068 SN - 1435-4934 VL - 21 IS - 4 SP - 1 EP - 7 PB - NDT.net CY - Kirchwald AN - OPUS4-34347 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Griesche, Axel A1 - Dabah, Eitan A1 - Kannengießer, Thomas A1 - Hilger, A. A1 - Kardjilov, N. A1 - Manke, I. A1 - Schillinger, B. T1 - Measuring hydrogen distributions in iron and steel using neutrons N2 - Neutron tomography has been applied to investigate the mechanism of hydrogen assisted cracking in technical iron and supermartensitic steel. Rectangular technical iron block samples showed blistering due to intense hydrogen charging and the tomographic method revealed in situ the spatial distribution of hydrogen and cracks. Hydrogen accumulated in a small region around cracks and the cracks are filled with hydrogen gas. Cracks close to the surface contained no hydrogen. Hydrogenous tensile test samples of supermartensitic steel were pulled until rupture and showed hydrogen accumulations at the notch base and in the plastically deformed region around the fracture surface. T2 - 10th World Conference on Neutron Radiography (WCNR) CY - Grindelwald, Switzerland DA - 05.10.2014 PY - 2015 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-348022 DO - https://doi.org/10.1016/j.phpro.2015.07.062 SN - 1875-3892 VL - 69 SP - 445 EP - 450 PB - Elsevier B.V. CY - Amsterdam AN - OPUS4-34802 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Wang, X. A1 - Pauli, Jutta A1 - Niessner, R. A1 - Resch-Genger, Ute A1 - Knopp, D. T1 - Gold nanoparticle-catalyzed uranine reduction for signal amplification in fluorescent assays for melamine and aflatoxin B1 N2 - A multifunctional fluorescence platform has been constructed based on gold nanoparticle (AuNP)-catalyzed uranine reduction. The catalytic reduction of uranine was conducted in aqueous solution using AuNPs as nanocatalyst and sodium borohydride as reducing reagent, which was monitored by fluorescence and UV-vis spectroscopy. The reaction rate was highly dependent on the concentration, size and dispersion state of AuNPs. When AuNPs aggregated, their catalytic ability decreased, and thereby a label-free fluorescent assay was developed for the detection of melamine, which can be used for melamine determination in milk. In addition, a fluorescent immunoassay for aflatoxin B1 (AFB1) was established using the catalytic reaction for signal amplification based on target-induced concentration change of AuNPs, where AFB1-BSA-coated magnetic beads and anti-AFB1 antibody-conjugated AuNPs were employed as capture and signal probe, respectively. The detection can be accomplished in 1 h and acceptable recoveries in spiked maize samples were achieved. The developed fluorescence system is simple, sensitive and specific, which could be used for the detection of a wide range of analytes. PY - 2015 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-347677 DO - https://doi.org/10.1039/c5an01300c SN - 0003-2654 SN - 1364-5528 VL - 140 IS - 21 SP - 7305 EP - 7312 PB - Royal Society of Chemistry CY - Cambridge AN - OPUS4-34767 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kruschwitz, Sabine T1 - NDT for microstructure and moisture investigation of porous building material N2 - Non-destructive testing methods are mostly applied and established for the detection of embedded mounting parts or structural defects in building elements. The assessment of the concrete microstructure or microstructural changes like chemical alterations or the formation of microcracks, e.g. due to material aging, freeze-thaw cycles, alkali-silica reaction and ettringite, is not in the focus of ndt research though. Concrete moisture and enhanced salt contents, which usually trigger all chemical microstructural changes, are other material properties, lacking reliable ways of measuring. But, the assessment of such material properties, on the long term also in a depth resolved manner, is definitely important, when the sustainability of our concrete infrastructure buildings shall be evaluated. New consideration like the potential use of ndt, in particular the combination of different methods and alternate ways of data analysis are subject of research currently undertaken at BAM. These approaches involve for example working towards (i) a deeper understanding of how to measure moisture distributions reliably and follow transport phenomena, (ii) the use of stray phenomena in radar and ultrasound to locate material inhomogeneities or (iii) the application of LIBS for the delineation of diffusion and migration processes but also (iv) the use of new tools for data analysis like data fusion. First results are presented and new ideas discussed. T2 - NDT-CE 2015 - International symposium non-destructive testing in civil engineering CY - Berlin, Germany DA - 15.09.2015 KW - Screed KW - Moisture KW - Non-destructive testing KW - Radar KW - Microstructure KW - Monitoring KW - Concrete deterioration KW - Cracking PY - 2015 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-347593 UR - http://www.ndt.net/?id=18354 SN - 1435-4934 VL - 20 IS - 11 SP - 1 EP - 5 PB - NDT.net CY - Kirchwald AN - OPUS4-34759 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kruschwitz, Sabine A1 - Feldmann, Rüdiger T1 - Comparison of non-destructive moisture measurement methods on cement and calcium sulphate based screed samples N2 - Measuring the moisture content of floor screeds is usually done with minor destructive testing methods like Darr drying or the Calcium Carbid (CM) method. These require small samples, deliver only punctual information and still have proven not to be very reliable. Hence, a study has been made using the standard destructive tests as well as a suite of non-destructive testing methods working out their use for moisture determination. In this study five partners from research institutes and industry worked together and intensively researched different technologies. The main focus was put on the varying sensitivity of the measuring techniques in different moisture ranges. Especially for low moisture contents ( or ‘critical’ moisture contents when the screed is dry enough to be covered with the final floor finish), several commercial devices including the most commonly used CM-method failed to determine the correct moisture content for cementitious samples. Hence the need for more accurate, if possible non-destructive methods is high, taking also into account that the chemistry (and physical properties) of screeds may vary strongly depending on their origin and purpose. T2 - NDT-CE 2015 - International symposium non-destructive testing in civil engineering CY - Berlin, Germany DA - 15.09.2015 KW - Screed KW - Moisture KW - Non-destructive testing KW - Radar KW - Capacitive methods KW - Resistivity KW - Multi-sensor KW - Electrics KW - Monitoring PY - 2015 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-347602 UR - http://www.ndt.net/?id=18368 SN - 1435-4934 VL - 20 IS - 11 SP - 1 EP - 4 PB - NDT.net CY - Kirchwald AN - OPUS4-34760 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kruschwitz, Sabine A1 - Bischof, Eik A1 - Taffe, A. T1 - Multi-sensor investigation of concrete moisture using ultrasound, radar and microwave N2 - Moisture and salt loads of concrete can significantly change its microstructure and consequently lead to chemical and mechanical degradation. However, the non-destructive investigation of moisture and salt present in concrete is still difficult. In order to address and compare the sensitivity of different methods concrete samples with different pore systems realized by varying the w/z ratios have been fabricated. The focus of this study was put on the analysis of ultrasonic long and trans waves measured on the surface and in transmission mode. The results show clear dependencies of all applied methods. With the radar and microwave methods predominantly changes in the concrete moisture could be detected, whereas the different pore systems were not observed to alter the signals. In contrast for the ultrasound method also the ongoing hydration as well as the nature of the pore system strongly influenced the signals. As a consequence in a subsequent drying experiment it was also tried to delineate the effects of moisture and hydration. All specimens have been re-saturated under pressure and the drying experiment was repeated using the same multi-sensor approach. T2 - NDT-CE 2015 - International symposium non-destructive testing in civil engineering CY - Berlin, Germany DA - 15.09.2015 KW - Concrete KW - Moisture KW - Non-destructive testing KW - Ultrasound KW - Radar KW - Velocities KW - Microwave KW - Multi-sensor approach PY - 2015 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-347612 UR - http://www.ndt.net/?id=18322 SN - 1435-4934 VL - 20 IS - 11 SP - 1 EP - 4 PB - NDT.net CY - Kirchwald AN - OPUS4-34761 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Manke, I. A1 - Kardjilov, N. A1 - Schäfer, R. A1 - Hilger, A. A1 - Grothausmann, R. A1 - Strobl, M. A1 - Dawson, M. A1 - Grünzweig, C. A1 - Tötzke, C. A1 - David, C. A1 - Kupsch, Andreas A1 - Lange, Axel A1 - Hentschel, Manfred P. A1 - Banhart, J. T1 - Three-dimensional imaging of magnetic domains with neutron grating interferometry N2 - This paper gives a brief overview on3D imaging of magnetic domains with shearing grating neutron tomography. We investigated the three-dimensional distribution of magnetic domain walls in the bulk of a wedge-shaped FeSi single crystal. The width of the magnetic domains wasanalyzed at different locations within the crystal. Magnetic domains close to the tip of the wedge are much smaller than in the bulk. Furthermore, the three-dimensional shape of individual domains wasinvestigated. We discuss prospects and limitations of the applied measurement technique. KW - Neutron imaging KW - Tomography KW - Magnetic domains KW - Grating interferometry KW - Darkfield imaging KW - Shearing gratings KW - Talbot-Lau KW - Three-dimensional data quantification KW - Tomographic reconstruction PY - 2015 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-341919 DO - https://doi.org/10.1016/j.phpro.2015.07.057 SN - 1875-3892 VL - 69 SP - 404 EP - 412 PB - Elsevier B.V. CY - Amsterdam AN - OPUS4-34191 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Helmerich, Rosemarie A1 - Mielentz, Frank A1 - Milmann, Boris A1 - Adam, Louisa A1 - Villalobos, S. A1 - Guimaraes, M. A1 - Wiggenhauser, Herbert T1 - Detection of cracks perpendicular to the surface using acoustic methods N2 - Cracks perpendicular to the surface may be initial indicators for a deterioration process of concrete structures. Moisture penetrates inside the structure and transports adverse chemicals. The paper presents an investigation about the reliability of available commercial non-destructive evaluation techniques to reliably estimate the depth of surface-breaking cracks in reinforced concrete structures. Aim of the study was the investigation of surface-braking cracks under laboratory conditions. Commercial acoustic devices as impact echo equipment, single ultrasonic transducers and arrays were applied even if they have not been developed for this purpose. The commercial software and descriptions for application was followed strictly to compare the function, precision and repeatability of the measurements. Both, perpendicular notches and cracks have been considered. The study was completed with a discussion about reference specimens. The study was the basis for formulation of gaps in research. The Electric Power Research Institute (EPRI) has initiated and funded a Project. T2 - NDT-CE 2015 - International symposium non-destructive testing in civil engineering CY - Berlin, Germany DA - 15.09.2015 KW - Acoustic test KW - Commercial acoustic devices KW - Ultrasonic test KW - Crack depth KW - Concrete specimens PY - 2015 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-345729 UR - https://www.ndt.net/?id=18412 SN - 1435-4934 VL - 20 IS - 11 SP - 1 EP - 9 PB - NDT.net CY - Kirchwald AN - OPUS4-34572 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Krause, Martin A1 - Mauke, R. A1 - Effner, Ute A1 - Milmann, Boris A1 - Völker, Christoph A1 - Wiggenhauser, Herbert T1 - Ultrasonic testing of a sealing construction made of salt concrete in an underground disposal facility for radioactive waste N2 - For the closure of radioactive waste disposal facilities engineered barriers- so called “drift seals” are used. The purpose of these barriers is to constrain the possible infiltration of brine and to prevent the migration of radionuclides into the biosphere. In a rock salt mine a large scale in-situ experiment of a sealing construction made of salt concrete was set up to prove the technical feasibility and operability of such barriers. In order to investigate the integrity of this structure, non-destructive ultrasonic measurements were carried out. Therefore two different methods were applied at the front side of the test-barrier: 1 Reflection measurements from boreholes 2 Ultrasonic imaging by means of scanning ultrasonic echo methods This extended abstract is a short version of an article to be published in a special edition of ASCE Journal that will briefly describe the sealing construction, the application of the non-destructive ultrasonic measurement methods and their adaptation to the onsite conditions -as well as parts of the obtained results. From this a concept for the systematic investigation of possible contribution of ultrasonic methods for quality assurance of sealing structures may be deduced. T2 - NDT-CE 2015 - International symposium non-destructive testing in civil engineering CY - Berlin, Germany DA - 2015-09-15 KW - Ultrasonic reflection measurement KW - Dry contact transducers in boreholes KW - Interface salt-concrete / rock salt KW - Ultrasonic imaging of internal reflectors PY - 2015 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-346203 UR - http://www.ndt.net/?id=18304 SN - 1435-4934 VL - 20 IS - 11 SP - 1 EP - 4 PB - NDT.net CY - Kirchwald AN - OPUS4-34620 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Millar, Steven A1 - Gottlieb, Cassian A1 - Wilsch, Gerd A1 - Eichler, Thorsten A1 - Bohling, C. A1 - Molkenthin, A. T1 - Laser induced breakdown spectroscopy (LIBS) - On-site investigatioons on a bridge with a mobile LIBS-system N2 - LIBS is on the step from a laboratory application to on-site analysis. A validated mobile LIBS-system for on-site application on building materials is under development at BAM in cooperation with industrial partners (system developers and companies), who will use this technique for investigation on building structures like bridges and parking decks. The system is designed to measure the content of harmful species like chlorine, sulfur or alkalis, to give the engineer a tool for the estimation of the condition of concrete structures and for quality assurance during concrete repair work on-site. In these work results of on-site measurements on a chloride contaminated bridge are shown. Further work will focus on providing guidelines to establish LIBS as a standard procedure for chemical investigations of building materials. T2 - NDT-CE 2015 - International symposium non-destructive testing in civil engineering CY - Berlin, Germany DA - 15.09.2015 KW - LIBS KW - Chlorides KW - Sulfur KW - Alkalis KW - Corrosion KW - ASR KW - Chemical analysis KW - Chloride KW - Elementanalyse KW - Natrium KW - Baustoffuntersuchungen KW - Baustoffe KW - Dauerhaftigkeit KW - Messsysteme KW - Mobiles LIBS PY - 2015 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-345795 UR - http://www.ndt.net/?id=18296 SN - 1435-4934 VL - 20 IS - 11 SP - 1 EP - 5 PB - NDT.net CY - Kirchwald AN - OPUS4-34579 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Fiedler Bremer, C. A1 - Scholz, R. A1 - Myslicki, S. A1 - Starke, P. A1 - Boller, C. A1 - Walther, F. A1 - Krause, Martin T1 - NDT-based characteriazation of timber and vulcanized fiber for civil infrastructure N2 - The paper addresses beech wood as well as vulcanized fiber and discusses the results obtained when using acoustic emission and thermography as non-destructive testing techniques along tensile and load increase fatigue tests to characterize the wooden material’s behavior under increasing fatigue loads to get enhanced information regarding the fatigue behavior of both materials. Reference is mainly made to the materials’ anisotropic and microstructural behavior and what implications this has with respect to the materials’ strength. The influence of moisture is discussed, as well as parameters that may deserve monitoring in the sense of structural health monitoring to be applied in timber structures in general. T2 - NDT-CE 2015 - International symposium non-destructive testing in civil engineering CY - Berlin, Germany DA - 15.09.2015 KW - Ermüdung KW - Belastungsversuch KW - Thermographie KW - ZfP KW - Timber PY - 2015 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-346377 UR - https://www.ndt.net/?id=18419 SN - 1435-4934 VL - 20 IS - 11 SP - 1 EP - 11 PB - NDT.net CY - Kirchwald AN - OPUS4-34637 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Grothe, Sven T1 - Ultrasonic signal evaluation used to detect temperature changes in a concrete specimen caused by a heating system N2 - Ultrasonic measurement evaluation methods have been proven to be effective for detection of subtle changes, caused by temperature, load or moisture. To detect and localize temperature changes, a concrete block of 4 × 5 × 0.8 m3, including a heating cartridge and multiple temperature sensors, has been set up to change the temperature and monitor the temperature distribution in a certain area inside the specimen. An ultrasonic monitoring system with 40 ultrasonic sensors (20 transmitters, 20 receivers, 25 kHz central frequency) has been implemented on the specimen. Data from 400 sensor combinations was collected over the whole period of the experiment in an interval of 30 minutes. Quantitative methods (CodaWave Interferometry and Time of Flight method) were used to evaluate the changes in ultrasonic travel-time caused by the heating period, when the cartridge was active, and the cooling period after turning off the cartridge. Furthermore the travel-time changes from all 400 sensor combinations were used to locate the heating cartridge. T2 - NDT-CE 2015 - International symposium non-destructive testing in civil engineering CY - Berlin, Germany DA - 15.09.2015 PY - 2015 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-346387 UR - http://www.ndt.net/?id=18336 SN - 1435-4934 VL - 20 IS - 11 SP - 1 EP - 4 PB - NDT.net CY - Kirchwald AN - OPUS4-34638 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Grothe, Sven T1 - Ultrasonic signal evaluation used to detect weather-related temperature changes in a concrete specimen N2 - Ultrasonic measurement evaluation methods have been proven to be effective for detection of subtle changes, caused by temperature, load or moisture. However, for its application outdoors it is necessary to analyse unavoidable influences, such as weather. Therefore an ultrasonic monitoring system with 40 ultrasonic sensors (20 transmitters, 20 receivers; 25 kHz central frequenzy) has been implemented on a concrete specimen (4×5×0.8m3), that is exposed to weather conditions. Data from 400 sensor combinations was collected over a period of six months with an interval of two hours. The data was evaluated by both qualitative (correlation techniques) and quantitative (ultrasonic velocity changes via Coda Wave Interferometry and time of flight method) evaluation methods and compared to the temperature changes caused by weather. T2 - NDT-CE 2015 - International symposium non-destructive testing in civil engineering CY - Berlin, Germany DA - 15.09.2015 PY - 2015 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-346398 UR - https://www.ndt.net/?id=18336 SN - 1435-4934 VL - 20 IS - 11 SP - 1 EP - 4 PB - NDT.net CY - Kirchwald AN - OPUS4-34639 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Völker, Christoph A1 - Shokouhi, P. T1 - Data aggregation for improved honeycomb detection in concrete using machine learning-based algorithms N2 - We present the results of several machine learning (ML)- inspired data fusion algorithms applied to multi-sensory nondestructive testing (NDT) data. Our dataset consists of Impact-Echo (IE), Ultrasonic Pulse Echo (US) and Ground Penetrating Radar (GPR) data collected on large-scale concrete specimens with built–in simulated honeycombing defects. The main objective is to improve the detectability of honeycombs by fusing the information from the three different sensors. We describe normalization, feature detection and optimal feature selection. We have used unsupervised and supervised ML, i.e., classification and clustering, for data fusion. We demonstrate the advantage of data fusion in reducing the false positives up to 10% compared to the best single sensor, thus, improving the detectability of the defects. The methods were evaluated on a concrete specimen. The effectiveness of the proposed approach was demonstrated on a separate full-scale concrete specimen. The results indicate the transportability of the conclusions from one specimen to the other. T2 - NDT-CE 2015 - International symposium non-destructive testing in civil engineering CY - Berlin, Germany DA - 15.09.2015 KW - Data fusion KW - Concrete evaluation KW - Honeycombing KW - Machine learning KW - Clustering PY - 2015 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-350968 UR - https://www.ndt.net/?id=18364 SN - 1435-4934 VL - 20 IS - 11 SP - 1 EP - 8 PB - NDT.net CY - Kirchwald AN - OPUS4-35096 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Müller, Werner A1 - Saathoff, F. T1 - Geosynthetics in geoenvironmental engineering N2 - Geosynthetics are planar polymeric products, which are used in connection with soil, rock or other soil-like materials to fulfill various functions in geoenvironmental engineering. Geosynthetics are of ever-growing importance in the construction industry. Sealing of waste storage facilities to safely prevent the emission of wastewater, landfill gas and contaminated dust as well as the diffusion of pollutants into the environment and coastal protection against storms and floods and reconstruction after natural disaster are important fields of application. We will give an overview of the various geosynthetic products. Two examples of the material problems related to geosynthetics are discussed in detail: the effect of creep on the long-term performance of geocomposite drains and the numerical simulation of the interaction of soil with geogrids. Both issues are of importance for the use of these products in landfill capping systems. The various functions, which geosynthetics may fulfill in the protection of coastal lines, are illustrated by case studies. The geosynthetic market is evaluated and economical and environmental benefits, as well as environmental side effects related to the use of geosynthetics, are discussed. KW - Geosynthetics KW - Geoenvironmental engineering KW - Landfill capping system KW - Coastal protection KW - Geocomposite drain KW - Geogrid KW - Geotextile PY - 2015 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-332014 DO - https://doi.org/10.1088/1468-6996/16/3/034605 SN - 1468-6996 VL - 16 IS - 3 SP - 034605-1 EP - 034605-20 PB - Elsevier Science CY - Amsterdam [u.a.] AN - OPUS4-33201 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Prager, Jens A1 - Grzeszkowski, M. T1 - Online-Überwachung des Bauteilzustandes von Eisenbahn-Radsatzwellen mitels geführter Ultraschallwellen N2 - Online-Strukturüberwachungssysteme sind eine Möglichkeit, den Anforderungen hinsichtlich Leichtbau und Zuverlässigkeit gleichzeitig gerecht zu werden. Die Integration solcher Systeme liefert aktuelle Informationen über die Integrität der sicherheitsrelevanten Struktur, wodurch sich Aussagen über notwendige Instandhaltungsarbeiten und möglicherweise über die zu erwartende Restlebensdauer ableiten lassen. Der zielgerichtete Einsatz der Überwachungssysteme ermöglicht es somit, die benötigten Sicherheitsfaktoren bei der Auslegung der Bauteile zu reduzieren und Wartungsintervalle zu verlängern. Dadurch können Kosten gesenkt werden, ohne die Zuverlässigkeit zu verringern. Im Rahmen einer Studie zur Machbarkeit eines Online-Überwachungssystems für Eisenbahn-Radsatzwellen wurde der Einsatz geführter Ultraschallwellen, die von Sensoren an einer Stirnseite der Wellen angeregt werden, demonstriert. Aufgrund der Bauteilgeometrie und der dispersiven, multimodalen Wellenausbreitung stellt die Interpretation der Echosignale eine wesentliche Herausforderung dar. Basierend auf dem a-priori-Wissen über die Wellenausbreitung wurden in der Studie klassifizierende Auswertealgorithmen entwickelt und erfolgreich an maßstabsgetreuen Labormodellen getestet. T2 - DACH-Jahrestagung 2015 CY - Salzburg, Austria DA - 11.05.2015 KW - Strukturüberwachung KW - Ultraschallprüfung KW - Zerstörungsfreie Prüfung PY - 2015 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-331931 SN - 978-3-940283-68-9 IS - DGZfP BB 152 SP - Poster 61, 1 EP - 2 PB - Deutsche Gesellschaft für Zerstörungsfreie Prüfung (DGZfP) AN - OPUS4-33193 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Prager, Jens A1 - Heide, M. A1 - Homann, Patrick Tobias A1 - Grzeszkowski, M. A1 - Gaal, Mate A1 - Dohse, Elmar T1 - Einseitig-berührungslose Ultraschallprüfung von Klebeverbindungen N2 - Durch den Einsatz von faserverstärkten Kunststoffen und Multi-Material-Konstruktionen zur Gewichtsreduzierung erlangen Klebeverbindungen immer stärkere Bedeutung. Die Prüfung dieser Fügeverbindungen stellt neue Anforderungen an die zerstörungsfreie Prüfung. Hinzu kommt, dass die Zugänglichkeit häufig eingeschränkt und die Verwendung flüssiger Koppelmittel aufgrund konstruktiver oder fertigungstechnischer Gegebenheiten ausgeschlossen ist. Unter Berücksichtigung dieser Beschränkungen wurde ein Prüfverfahren entwickelt, das eine luftgekoppelte Anregung geführter Ultraschallwellen mit einer laserbasierten Detektion kombiniert. Nachdem das Prüfverfahren zunächst mit einer einfachen Signalauswertung im Zeitbereich getestet wurde, konnte in nachfolgenden Untersuchungen die örtliche Auflösung durch die Implementierung von Filteralgorithmen im Frequenz-Wellenzahl-Bereich und zusätzlich durch direktionale Filter erhöht werden. Das resultierende bildgebende Prüfverfahren wurde an realitätsnahen Klebeproben mit künstlichen Fehlern getestet. Die Zuverlässigkeit und Ortsauflösung des Verfahrens wurde im Vergleich mit herkömmlichen Prüfverfahren validiert. Mithilfe des Verfahrens können Poren, Einschlüsse und Bereiche mit ungenügender Verklebung detektiert werden. T2 - DACH-Jahrestagung 2015 CY - Salzburg, Austria DA - 11.05.2015 KW - Strukturüberwachung KW - Ultraschallprüfung KW - Zerstörungsfreie Prüfung PY - 2015 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-331944 SN - 978-3-940283-68-9 IS - DGZfP BB 152 SP - Mo.2.B.4, 1 EP - 7 PB - Deutsche Gesellschaft für Zerstörungsfreie Prüfung (DGZfP) AN - OPUS4-33194 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Fischer, Franziska A1 - Scholz, G. A1 - Batzdorf, Lisa A1 - Wilke, Manuel A1 - Emmerling, Franziska T1 - Synthesis, structure determination, and formation of a theobromine: oxalic acid 2:1 cocrystal N2 - The structure and the formation pathway of a new theobromine : oxalic acid (2 : 1) cocrystal are presented. The cocrystal was synthesised mechanochemically and its structure was solved based on the powder X-ray data. The mechanochemical synthesis of this model compound was studied in situ using synchrotron XRD. Based on the XRD data details of the formation mechanism were obtained. The formation can be described as a self-accelerated ('liquid like') process from a highly activated species. KW - ssNMR spectroscopy KW - Synchrotron measurements KW - API molecule PY - 2015 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-331567 DO - https://doi.org/10.1039/c4ce02066a SN - 1466-8033 VL - 17 IS - 4 SP - 824 EP - 829 CY - London, UK AN - OPUS4-33156 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kramer, Claus A1 - Ried, Peter A1 - Mahn, Stefan A1 - Richter, Silke A1 - Langhammer, Nicole A1 - Kipphardt, Heinrich T1 - Design and application of a versatile gas calibration for non-metal determination by carrier gas hot extraction N2 - In carrier gas hot extraction the calibration of low amounts of non-metals with masses of a few micrograms with small uncertainty remains a challenge. To achieve high flexibility a high precision gas mixture pump was combined with an automated syringe drive. The gas mixing pump allows filling the syringe with different gas compositions; the automated syringe drive allows matching to modulate the signal profiles to those of real samples. The system was designed and its experimental potential explored. The resulting calibration curves were comparable to those obtained by calibration using solid materials of sufficient purity and stoichiometry. However smaller uncertainties and lower limits of quantification (i.e. 0.5 µg and 0.6 µg for O and N, respectively) were found using the gas calibration device. KW - Non-metal determination KW - CGHE KW - Gas calibration PY - 2015 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-336130 DO - https://doi.org/10.1039/c5ay00845j SN - 1759-9660 SN - 1759-9679 VL - 7 IS - 13 SP - 5468 EP - 5475 PB - RSC Publ. CY - Cambridge AN - OPUS4-33613 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kotschate, Daniel A1 - Meinig, Silvia A1 - Heckel, Thomas T1 - Bestimmung der Richtcharakteristik von Senkrecht- und Winkelprüfköpfen in Kontakttechnik N2 - Für den stetigen Einsatz und die erhöhten Anforderungen bei der mechanisierten Prüfung sowie in der Handprüfung ist notwendig, einen möglichst genauen Eindruck bzgl. Funktionsweise und Zuverlässigkeit der eingesetzten Prüfmittel zu besitzen. Prüfköpfe weisen, wie jedes andere technische Erzeugnis gewisse Toleranzen hinsichtlich Fertigungs- und Alterungsprozessen auf, welche sich speziell bei Winkelprüfköpfen durch eine Verschiebung des Nominalwinkels äußern können. Die Definition der Parameter von Prüfköpfen und entsprechende Methoden zu deren Überprüfung sind in der DIN EN 12668-2 geregelt. Von der BAM werden für diese Aufgaben Richtcharakteristikmessplätze eingesetzt. Um auf die gestiegenen Anforderungen hochauflösender Prüfungen zu reagieren wurde der Richtcharakteristikmessplatz modernisiert. Dabei wurde für die teil-automatisierte Untersuchung der akustischen Parameter (z.B. Einschallwinkel) unter Verwendung digitaler Messdatenverarbeitung - ein neuer Messplatz für die Überprüfung sowie Untersuchung von Prüfkopftoleranzen und Alterungsprozessen realisiert. Der Messplatz verfügt über eine hochauflösende Messdatenerfassung sowie einer automatisierten Protokollierung der erhobenen Messdaten. T2 - DACH-Jahrestagung 2015 CY - Salzburg, Austria DA - 11.05.2015 PY - 2015 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-336729 SN - 978-3-940283-68-9 IS - DGZfP BB 152 SP - Poster 57, 1 EP - 4 PB - Deutsche Gesellschaft für Zerstörungsfreie Prüfung (DGZfP) AN - OPUS4-33672 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kotschate, Daniel A1 - Gohlke, Dirk A1 - Heckel, Thomas T1 - Bestimmung der Richtcharakteristik von fokussierenden Prüfköpfen in Tauchtechnik N2 - Für eine hochauflösende Untersuchung von sicherheitsrelevanten Bauteilen innerhalb der Tauchtechnik haben fokussierende Prüfköpfe eine hohe Verbreitung erlangt. Für den Einsatz moderner und komplexer Rekonstruktionsverfahren bildet jedoch die Kenntnis über Schallfeldgeometrie, insbesondere die Lage und Ausdehnung der Fokusbereichs und die Empfindlichkeit des verwendeten Prüfkopfs in Abhängigkeit zum Schallweg, eine entscheidende Rolle für die Datenrekonstruktion und die abschließende Bauteildiagnose. Für die automatisierte Bestimmung der wichtigsten Kenngrößen (bspw. Lage und Länge des Fokuspunkts bzw. Fokusschlauchs, sowie des Schallbündel-durchmessers) wurde die Schalldruckverteilung mechanisiert, vierdimensional (x,y,z,t) vermessen und unter Einsatz der digitalen Signal- und Bildverarbeitung, ein vollautomatisches Analysewerkzeug erarbeitet. Weiterhin konnte anhand des Messdatensatzes und unter Einsatz von dreidimensionalen Rekonstruktions- und Visualisierungstechniken das Schallfeld bzw. die Schalldruckverteilung dreidimensional abgebildet werden und für etwaige Nachuntersuchungen von Simulationsergebnissen oder allein zur Visualisierung eingesetzt werden. T2 - DACH-Jahrestagung 2015 CY - Salzburg, Austria DA - 11.05.2015 PY - 2015 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-336733 SN - 978-3-940283-68-9 IS - 152 SP - P46, 1 EP - 4 PB - Deutsche Gesellschaft für Zerstörungsfreie Prüfung (DGZfP) AN - OPUS4-33673 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Mirtschin, Nikolaus A1 - Pretsch, Thorsten T1 - Designing temperature-memory effects in semicrystalline polyurethane N2 - Temperature-memory polymers are able to generate a substantial mechanical response when heated above the temperature, at which a preceding deformation was carried out. Here we show how to design the temperature-memory effect (TME) by thermomechanical treatment. As a model polymer, phase segregated poly(ester urethane) (PEU) containing crystallizable segments of poly(1,4-butylene adipate) (PBA) was used. For programming, strain elongation was applied at temperatures within the PBA melting transition area, before temperature holding, unloading and cooling were carried out. Upon heating under stress-free or constant strain recovery conditions, precisely set temperature-memory onsets could be witnessed. Most importantly, strain fixities and recoverabilities the same as maximum recovery stresses turned out to be controllable by strain rate and temperature holding time after deformation, while transition temperatures remained largely unaffected. The tailoring of thermoresponsiveness was structurally enabled by different PBA crystallinities in the programmed state as verified by wide-angle X-ray scattering (WAXS). The reported studies intend to design TMEs in semicrystalline polyurethanes according to user-defined needs to make this technology broadly applicable. KW - Poly(ester urethane) KW - Shape memory polymer KW - Temperature-memory effect KW - Thermo-responsiveness KW - Temperature-memory polymer KW - Programming KW - Thermomechanical properties PY - 2015 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-332856 DO - https://doi.org/10.1039/c5ra05492c SN - 2046-2069 VL - 5 IS - 57 SP - 46307 EP - 46315 PB - RSC Publishing CY - London AN - OPUS4-33285 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schlick-Hasper, Eva A1 - Goedecke, Thomas A1 - Kraume, M. T1 - Überdruck in Gefahrgutverpackungen unter normalen Beförderungsbedingungen N2 - Für die Durchführung einer Dichtheitsprüfung und für die Bewertung des Ergebnisses ist es wichtig, den sich unter Betriebsbedingungen im Prüfobjekt einstellenden Überdruck zu kennen. Entspricht der Prüfüberdruck nicht dem Betriebsüberdruck, so ist es oft erforderlich, die unter Prüfbedingungen gemessenen Leckageraten auf den realen Betriebsüberdruck umzurechnen. Im Bereich der Gefahrgutverpackungen ist jedoch der spätere maximale Betriebsüberdruck nicht genau bekannt. Er hängt für jede einzelne Verpackungsbauart von dem eingefüllten Füllmedium mit seinen spezifischen Stoffeigenschaften, dem Füllgrad sowie den Beförderungsbedingungen, insbesondere der mittleren Transporttemperatur, ab. Es werden Berechnungsansätze vorgestellt, mit denen sich der Überdruck in Gefahrgutverpackungen unter Beförderungsbedingungen rechnerisch ermitteln lässt. Die theoretisch berechneten Überdrücke werden mit Überdruck-Messwerten verglichen, die mit verschiedenen Füllmedien in unterschiedlichen Verpackungsbauarten ermittelt wurden. T2 - DACH-Jahrestagung 2015 CY - Salzburg, Austria DA - 11.05.2015 KW - Gefahrgutverpackungen KW - Überdruck PY - 2015 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-332563 SN - 978-3-940283-68-9 IS - DGZfP BB 152 SP - Di.3.B.1, 1 EP - 13 AN - OPUS4-33256 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Wilhelm, Stefan A1 - Kaiser, Martin A1 - Würth, Christian A1 - Heiland, J. A1 - Carrillo-Carrion, C. A1 - Muhr, V. A1 - Wolfbeis, Otto S. A1 - Parak, W.J. A1 - Resch-Genger, Ute A1 - Hirsch, T. T1 - Water dispersible upconverting nanoparticles: effects of surface modification on their luminescence and colloidal stability N2 - We present a systematic study on the effect of surface ligands on the luminescence properties and colloidal stability of β-NaYF4:Yb3+,Er3+ upconversion nanoparticles (UCNPs), comparing nine different surface coatings to render these UCNPs water-dispersible and bioconjugatable. A prerequisite for this study was a large-scale synthetic method that yields ~2 g per batch of monodisperse oleate-capped UCNPs providing identical core particles. These ~23 nm sized UCNPs display an upconversion quantum yield of ~0.35% when dispersed in cyclohexane and excited with a power density of 150 W cm-2, underlining their high quality. A comparison of the colloidal stability and luminescence properties of these UCNPs, subsequently surface modified with ligand exchange or encapsulation protocols, revealed that the ratio of the green (545 nm) and red (658 nm) emission bands determined at a constant excitation power density clearly depends on the surface chemistry. Modifications relying on the deposition of additional (amphiphilic) layer coatings, where the initial oleate coating is retained, show reduced non-radiative quenching by water as compared to UCNPs that are rendered water-dispersible via ligand exchange. Moreover, we could demonstrate that the brightness of the upconversion luminescence of the UCNPs is strongly affected by the type of surface modification, i.e., ligand exchange or encapsulation, yet hardly by the chemical nature of the ligand. KW - upconverting nanoparticles (UCNPs) KW - Luminescence KW - surface modification PY - 2015 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-324071 DO - https://doi.org/10.1039/c4nr05954a SN - 2040-3364 SN - 2040-3372 VL - 7 IS - 4 SP - 1403 EP - 1410 PB - RSC Publ. CY - Cambridge AN - OPUS4-32407 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Lukowiak, M.C. A1 - Wettmarshausen, Sascha A1 - Hidde, Gundula A1 - Landsberger, Petra A1 - Boenke, Viola A1 - Rodenacker, K. A1 - Braun, Ulrike A1 - Friedrich, Jörg Florian A1 - Gorbushina, Anna A1 - Haag, R. T1 - Polyglycerol coated polypropylene surfaces for protein and bacteria resistance N2 - Polyglycerol (PG) coated polypropylene (PP) films were synthesized in a two-step approach that involved plasma bromination and subsequently grafting hyperbranched polyglycerols with very few amino functionalities. The influence of different molecular weights and density of reactive linkers were investigated for the grafted PGs. Longer bromination times and higher amounts of linkers on the surface afforded long-term stability. The protein adsorption and bacteria attachment of the PP-PG films were studied. Their extremely low amine content proved to be beneficial for preventing bacteria attachment. PY - 2015 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-325406 DO - https://doi.org/10.1039/c4py01375a SN - 1759-9954 SN - 1759-9962 VL - 6 IS - 8 SP - 1350 EP - 1359 AN - OPUS4-32540 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Krause, Christina A1 - Zorn, R. A1 - Frick, B. A1 - Schönhals, Andreas T1 - Quasi- and inelastic neutron scattering to investigate the molecular dynamics of discotic molecules in the bulk N2 - In- and quasielastic neutron scattering is employed to investigate both the vibrational density of states and the molecular dynamics of two homologous discotic liquid crystals (DLC) with different length of the alkyl side chain based on a triphenylene derivate. For both compounds characteristic low frequency excess contributions to the vibrational density of states are found. Therefore it is concluded that these liquid crystals show a glass-like behaviour. Elastic scans further show that in these materials a rich molecular dynamics takes place. T2 - QENS/WINS 2014 - 11th International Conference on Quasielastic Neutron Scattering and 6th International Workshop on Inelastic Neutron Spectrometers CY - Autrans, France DA - 2014-05-11 PY - 2015 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-325477 DO - https://doi.org/10.1051/epjconf/20158302017 SN - 2100-014X VL - 83 SP - 02017-1 EP - 02017-4 PB - EDP Sciences CY - Les Ulis AN - OPUS4-32547 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Siebler, Daniel A1 - Rohwetter, Philipp A1 - Brusenbach, R. A1 - Plath, R. T1 - Optical-only detection of partial discharge with fluorescent polymer optical fiber sensors N2 - This paper reflects recent progress in the field of fluorescent polymer optical fiber sensors (F-POF) for partial discharge (PD) detection in high voltage (HV) cable accessories using optical-only PD detection by coincidence single photon counting. In experiments with artificial PD sources these sensors show the ability to detect optical emissions from picocoulomb-level PDs in a real-scale model of a translucent high voltage cable accessory. False positives (caused by detector noise) are efficiently suppressedwhile maintaining sufficient sensitivity,even when the sensor is located in an unfavorable position. T2 - EUROSENSORS 2015 CY - Freiburg, Germany DA - 06.09.2015 KW - Partial discharge KW - Silicone rubber KW - High voltage cable accessories KW - Polymer optical fiber POF KW - Fluorescence KW - Coincidence PY - 2015 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-337881 DO - https://doi.org/10.1016/j.proeng.2015.08.711 SN - 1877-7058 VL - 120 SP - 845 EP - 848 PB - Elsevier Ltd. CY - Amsterdam AN - OPUS4-33788 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - RPRT A1 - Hodoroaba, Vasile-Dan A1 - Mielke, Johannes T1 - Techniques evaluation report for selection of characterisation methods N2 - This report is the result of a comprehensive study on the available CMs which come potentially in question for the reliable analysis of the number based size distribution of a nanomaterial according to the EC recommendation for a definition of nanomaterial. Based on the performance criteria already established in NanoDefine the potential CMs are evaluated according to studies available in the literature as well as following the expertise of the NanoDefine consortium partners. The specific advantages and disadvantages of each method with respect to its applicability to the scope of NanoDefine are particularly highlighted. An CM evaluation table is produced so that the mostly suited CMs with respect to the EC definition can be grouped and recommended to the corresponding NanoDefine work packages for further specific development (improvement and adaption), or for direct validation and standardisation, respectively. The actual evaluation report including the recommended CMs will be revised and, if necessary, eventually updated at the mid time of the project. The update will be jointly discussed in the NanoDefine consortium on the basis of the results of testing the methods on the NanoDefine real world materials. KW - Nanomaterial KW - Characterization method KW - EC definition PY - 2015 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-389473 UR - http://www.nanodefine.eu/publications/reports/NanoDefine_TechnicalReport_D3.1.pdf SP - D3.1, 1 EP - 57 CY - Wageningen, The Netherlands AN - OPUS4-38947 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - RPRT A1 - Rauscher, H. A1 - Mech, A. A1 - Gaillard, C. A1 - Stintz, M. A1 - Wohlleben, W. A1 - Weigel, St. A1 - Ghanem, A. A1 - Hodoroaba, Vasile-Dan A1 - Babick, F. A1 - Mielke, Johannes T1 - Recommendations on a Revision of the EC Definition of Nanomaterial Based on Analytical Possibilities N2 - In October 2011 the European Commission (EC) published a "Recommendation on the definition of nanomaterial" (2011/696/EU), to promote consistency in the interpretation of the term "nanomaterial" for legislative and policy purposes in the EU. The EC NM Definition includes a commitment to its review in the light of experience and of scientific and technological developments. This review is ongoing in 2015 and as a contribution to the review the Joint Research Centre of the European Commission (JRC) has already developed a series of three scientific-technical reports with the title: “Towards a review of the EC Recommendation for a definition of the term nanomaterial” which provides to the EC policy services science-based options on how the definition could be revised or supported with additional guidance. The overarching nature and wide scope of the EC NM Definition, as it does not exclude a priori any particulate material regardless the state, form and size, creates many analytical challenges in its imple-mentation for all stakeholders, including enterprises and regulators. The NanoDefine project has as core objective to support the implementation of the EC NM Definition. In this report key aspects of the EC NM Definition are addressed, with the goal to improve the implement-ability of the EC NM Definition. These aspects are presented and discussed based on the results of two years of research performed within the framework of the project. As a result this report assesses how well the requirements of the EC NM Definition can be fulfilled with currently available analytical possi-bilities. It presents recommendations and options on a revision of the EC NM Definition to improve the implementability of the definition based on currently available analytical possibilities, according to the state of the art of mid-2015. Of the technical issues considered in this report, the following seem to deserve the most attention in terms of clarification of the definition and/or provision of additional implementation guidance:  The term ‘external dimension’. A clear definition of 'External dimension' should be included in the text of the EC NM definition and more precise guidance on what is considered as an external dimension and how to properly character-ise it should be provided.  The ‘number based particle size distribution‘. The EC NM Definition uses a threshold related to the number based size distribution of particles. Yet most of the easily available techniques provide a mass-, volume- or scattered light intensity-based size distribution which needs to be converted into a number based distribution to be used for regulatory pur-poses. A specific guidance on the conditions under which these methods can be used to identify a na-nomaterial by employing appropriate quantity or metrics conversion should be provided.  The ‘polydispersity‘ and ‘upper size limit‘ Polydispersity is a challenge for the measurement of particle size distribution for the EC NM definition, specifically for materials with high polydispersity index and broad size distribution especially when the volume or mass of the fraction containing particles below 100 nm is very small. Therefore a dedicated guidance should be provided that allows applying an upper size limit in measurements and particle statistics. KW - Nanomaterial KW - EU Definition of nanomaterial KW - Nanoparticles PY - 2015 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-432339 UR - http://www.nanodefine.eu/publications/reports/NanoDefine_TechnicalReport_D7.10.pdf SP - 1 EP - 68 PB - The NanoDefine Consortium CY - Wageningen, The Netherlands AN - OPUS4-43233 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Tammas-Williams, S. A1 - Zhao, H. A1 - Léonard, Fabien A1 - Derguti, F. A1 - Todd, I. A1 - Prangnell, P.B. T1 - XCT analysis of the influence of melt strategies on defect population in Ti-6Al-4V components manufactured by Selective Electron Beam Melting N2 - Selective Electron Beam Melting (SEBM) is a promising powder bed Additive Manufacturing technique for near-net-shape manufacture of high-value titanium components. However without post-manufacture HIPing the fatigue life of SEBM parts is currently dominated by the presence of porosity. In this study, the size, volume fraction, and spatial distribution of the pores in model samples have been characterised in 3D, using X-ray Computed Tomography, and correlated to the process variables. The average volume fraction of the pores (b0.2%) was measured to be lower than that usually observed in competing processes, such as selective laser melting, but a strong relationship was found with the differentbeamstrategies used to contour ,and infill by hatching, a part section. The majority of pores were found to be small spherical gas pores, concentrated in the infill hatched region; this was attributed to the lower energy density and less focused beam used in the infill strategy allowing less opportunity for gas bubbles to escape the melt pool. Overall, increasing the energy density or focus of the beam was found to correlate strongly to a reduction in the level of gas porosity. Rarer irregular shaped pores were mostly located in the contour region and have been attributed to a lack of fusion between powder particles. KW - Titanium KW - Additive Manufacture KW - Selective Electron Beam Melting KW - Pores KW - X-ray computed tomography PY - 2015 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-416577 UR - http://www.sciencedirect.com/science/article/pii/S104458031500039X?via%3Dihub DO - https://doi.org/10.1016/j.matchar.2015.02.008 VL - 102 SP - 47 EP - 61 CY - Materials Characterization AN - OPUS4-41657 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Casperson, Ralf A1 - Heideklang, René A1 - Myrach, Philipp A1 - Onel, Yener A1 - Pelkner, Matthias A1 - Pohl, Rainer A1 - Stegemann, Robert A1 - Ziegler, Mathias A1 - Kreutzbruck, Marc T1 - Vergleich konventioneller und neuer Oberflächenprüfverfahren für ferromagnetische Werkstoffe N2 - Sicherheitsrelevante und zyklisch hoch belastete Bauteile erfordern zur Vermeidung von kostenintensiven Ausfällen besonders stabile Prozessparameter. Bereits sehr kleine Randzonenfehler können unter zyklischer Bauteilbelastung zu Risswachstum und letztendlich zum Bauteilversagen führen. Die frühzeitige Erkennung von Randzonenfehler in Hochleistungsbauteilen wie z.B. Zahnräder, Ritzelwellen und Kurbelwellen erfordert daher eine leistungsfähige zerstörungsfreie Oberflächenrissprüfung, die es ermöglicht in den hochbeanspruchten Funktionsflächen auch Härterisse, Schleifrisse oder Zundereinschlüsse zu detektieren. Hierzu sind in den letzten Jahren einige neue, innovative Oberflächenprüfverfahren wie die laserangeregte Thermografie und die Streuflussprüfung mit hochauflösenden GMR-Sensoren oder magnetooptischen Verfahren entwickelt worden. Zusätzlich zur hohen Empfindlichkeit zeichnen sich diese innovativen Verfahren durch einen schnellen und teils auch berührungslosen Einsatz aus. Da die noch relativ neu-en Verfahren naturgemäß noch nicht normativ verankert sind, wurden auch bereits erste Validierungen durchgeführt. Um die Leistungsfähigkeit der Verfahren eingehend zu untersuchen, erfolgten Testreihen an verschiedenen Testkörpern in Bezug auf Ortsauflösung, Empfindlichkeit, Automatisierung und Bewertung der Messsig-nale. Neben den neuen Verfahren und ihren ersten Schritten hin zur Validierung kamen als Referenz auch die „klassischen“ Verfahren der Magnetpulver- und Wirbelstromprüfung zum Einsatz, deren Leistungsfähigkeit durch angepasste Sondenentwicklung auch für sehr kleine Oberflächendefekte nochmals unter Beweis gestellt wurde. Zusätzlich wurde an einigen Testkörpern eine hochauflösende CT durchgeführt. Die Ergebnisse dieses Vergleiches werden vorgestellt und Möglichkeiten sowie Grenzen der einzelnen Verfahren herausgearbeitet. T2 - DACH-Jahrestagung 2015 CY - Salzburg, Austria DA - 11.05.2015 KW - Zerstörungsfreie Prüfung KW - Oberflächenprüfung KW - Vergleichskörper 1 KW - Sichtprüfung KW - Magnetpulverprüfung KW - Streuflussprüfung KW - Farbeindringprüfung KW - Wirbelstromprüfung KW - Thermografie KW - Radiografie PY - 2015 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-344262 SN - 978-3-940283-68-9 IS - DGZfP BB 152 SP - Mi.2.B.4, 1 EP - 11 PB - Deutsche Gesellschaft für Zerstörungsfreie Prüfung (DGZfP) AN - OPUS4-34426 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Menzel, M. A1 - Scharf, O. A1 - Novak, S. A1 - Radtke, Martin A1 - Reinholz, Uwe A1 - Hischenhuber, P. A1 - Buzanich, Günter A1 - Meyer, A. A1 - Lopez, V. A1 - McIntosh, K. A1 - Streli, C. A1 - Havrilla, G. A1 - Fittschen, U. T1 - Shading in TXRF: calculations and experimental validation using a color X-ray camera N2 - Absorption effects in total reflection X-ray fluorescence (TXRF) analysis are important to consider, especially if external calibration is to be applied. With a color X-ray camera (CXC), that enables spatially and energy resolved XRF analysis, the absorption of the primary beam was directly visualized for mL-droplets and an array of pL-droplets printed on a Si-wafer with drop-on-demand technology. As expected, deposits that are hit by the primary beam first shade subsequent droplets, leading to a diminished XRF signal. This shading effect was quantified with enhanced precision making use of sub-pixel analysis that improves the spatial resolution of the camera. The measured absorption was compared to simulated results using three different model calculations. It was found they match very well (average deviation < 10%). Thus errors in quantification due to absorption effects can be accounted for in a more accurate manner. KW - absorption KW - X-ray Fluorescence analysis PY - 2015 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-359000 DO - https://doi.org/10.1039/C5JA00127G IS - 10 SP - 2184 EP - 2193 PB - Royal Society of Chemistry CY - Cambridge AN - OPUS4-35900 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kabelitz, Anke A1 - de Oliveira Guilherme Buzanich, Ana A1 - Joester, Maike A1 - Reinholz, Uwe A1 - Radtke, Martin A1 - Bienert, Ralf A1 - Schulz, K. A1 - Schmack, R. A1 - Kraehnert, R. A1 - Emmerling, Franziska T1 - Time-resolved in situ studies on the formation mechanism of iron oxide nanoparticles using combined fast-XANES and SAXS N2 - The reaction of iron chlorides with an alkaline reagent is one of the most prominent methods for the synthesis of iron oxide nanoparticles. We studied the particle formation mechanism using triethanolamine as reactant and stabilizing agent. In situ fast-X-ray absorption near edge spectroscopy and small-angle X-ray scattering provide information on the oxidation state and the structural information at the same time. In situ data were complemented by ex situ transmission electron microscopy, wide-angle X-ray scattering and Raman analysis of the formed nanoparticles. The formation of maghemite nanoparticles (γ-Fe2O3) from ferric and ferrous chloride was investigated. Prior to the formation of these nanoparticles, the formation and conversion of intermediate phases (akaganeite, iron(II, III) hydroxides) was observed which undergoes a morphological and structural collapse. The thus formed small magnetite nanoparticles (Fe3O4) grow further and convert to maghemite with increasing reaction time. KW - oxidation state KW - structural information KW - maghemite PY - 2015 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-351376 DO - https://doi.org/10.1039/C5CE01585E SN - 1466-8033 VL - 17 IS - 44 SP - 8463 EP - 8470 CY - London, UK AN - OPUS4-35137 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Nowak, S.H. A1 - Bjeoumikhov, A. A1 - Von Borany, J. A1 - Buchriegler, J. A1 - Munnik, F. A1 - Petric, M. A1 - Radtke, Martin A1 - Renno, A.D. A1 - Reinholz, Uwe A1 - Scharf, O. A1 - Wedell, R. T1 - Sub-pixel resolution with a color X-ray camera N2 - The color X-ray camera SLcam® is a full-field, single photon detector providing scanning-free, energy and spatially resolved X-ray imaging. Spatial resolution is achieved with the use of polycapillary optics guiding X-ray photons from small regions on a sample to distinct energy dispersive pixels on a charged-coupled device detector. Applying sub-pixel resolution, signals from individual capillary channels can be distinguished. Therefore, the SLcam® spatial resolution, which is normally limited to the pixel size of the charge-coupled device, can be improved to the size of individual polycapillary channels. In this work a new approach to a sub-pixel resolution algorithm comprising photon events also from the pixel centers is proposed. The details of the employed numerical method and several sub-pixel resolution examples are presented and discussed. KW - Color X-ray camera KW - Sub pixel analysis PY - 2015 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-334948 DO - https://doi.org/10.1039/c5ja00028a SN - 0267-9477 SN - 1364-5544 SP - 1890 EP - 1897 PB - Royal Society of Chemistry CY - London AN - OPUS4-33494 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Geißler, Daniel A1 - Gollwitzer, C. A1 - Sikora, A. A1 - Minelli, C. A1 - Krumrey, M. A1 - Resch-Genger, Ute T1 - Effect of fluorescent staining on size measurements of polymeric nanoparticles using DLS and SAXS N2 - The influence of fluorescence on nanoparticle size measurements using dynamic light scattering (DLS) and small angle X-ray scattering (SAXS) was investigated. For this purpose, two series of 100 nm-sized polymer nanoparticles stained with different concentrations of the fluorescent dyes DY555 and DY680 were prepared, absorbing/emitting at around 560 nm/590 nm and 695 nm/715 nm, respectively. SAXS measurements of these particle series and a corresponding blank control (without dye) revealed similar sizes of all particles within an uncertainty of 1 nm. DLS measurements carried out at three different laboratories using four different DLS instruments and two different laser wavelengths, i.e., 532 nm and 633 nm, revealed also no significant changes in size (intensity-weighted harmonic mean diameter, ZAverage) and size distribution (polydispersity index, PI) within and between the two dye-stained particle series and the blank sample. Nevertheless, a significant decrease of the detected correlation coefficients was observed with increasing dye concentration, due to the increased absorption of the incident light and thus, less coherent light scattering. This effect was wavelength dependent, i.e. only measurable for the dye-stained particles that absorb at the laser wavelength used for the DLS measurements. PY - 2015 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-349684 DO - https://doi.org/10.1039/C5AY02005K SN - 1759-9660 SN - 1759-9679 VL - 7 IS - 23 SP - 9785 EP - 9790 PB - RSC Publ. CY - Cambridge AN - OPUS4-34968 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Roebben, G. A1 - Kestens, V. A1 - Varga, Z. A1 - Charoud-Got, J. A1 - Ramaye, Y. A1 - Gollwitzer, Christian A1 - Bartczak, D. A1 - Geißler, Daniel A1 - Noble, J.E. A1 - Mazoua, S. A1 - Meeus, N. A1 - Corbisier, P. A1 - Palmai, M. A1 - Mihály, J. A1 - Krumrey, M. A1 - Davies, J. A1 - Resch-Genger, Ute A1 - Kumarswami, N. A1 - Minelli, C. A1 - Sikora, A. A1 - Goenaga-Infante, H. T1 - Reference materials and representative test materials to develop nanoparticle characterization methods: the NanoChOp project case N2 - This paper describes the production and characteristics of the nanoparticle test materials prepared for common use in the collaborative research project NanoChOp (Chemical and optical characterization of nanomaterials in biological systems), in casu suspensions of silica nanoparticles and CdSe/CdS/ZnS quantum dots (QDs). This paper is the first to illustrate how to assess whether nanoparticle test materials meet the requirements of a "reference material" (ISO Guide 30, 2015) or rather those of the recently defined category of "representative test material (RTM)" (ISO/TS 16195, 2013). The NanoChOp test materials were investigated with small-angle X-ray scattering (SAXS), dynamic light scattering (DLS), and centrifugal liquid sedimentation (CLS) to establish whether they complied with the required monomodal particle size distribution. The presence of impurities, aggregates, agglomerates, and viable microorganisms in the suspensions was investigated with DLS, CLS, optical and electron microscopy and via plating on nutrient agar. Suitability of surface functionalization was investigated with attenuated total reflection Fourier transform infrared spectrometry (ATR-FTIR) and via the capacity of the nanoparticles to be fluorescently labeled or to bind antibodies. Between-unit homogeneity and stability were investigated in terms of particle size and zeta potential. This paper shows that only based on the outcome of a detailed characterization process one can raise the status of a test material to RTM or reference material, and how this status depends on its intended use. KW - Nanoparticle KW - Materials characterization KW - Reference material KW - Analytical quality assurance KW - Metrology PY - 2015 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-349644 DO - https://doi.org/10.3389/fchem.2015.00056 SN - 2296-2646 VL - 3 SP - Article 56, 1 EP - 16 PB - Frontiers Media CY - Lausanne AN - OPUS4-34964 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Würth, Christian A1 - Geißler, Daniel A1 - Resch-Genger, Ute T1 - Quantification of anisotropy-related uncertainties in relative photoluminescence quantum yield measurements of nanomaterials - semiconductor quantum dots and rods N2 - In order to assess the anisotropy-related uncertainties of relatively determined photoluminescence quantum yields (ΦPL) of molecular emitters and luminescent nanomaterials, we compared ΦPL values measured without and with polarizers using magic angle conditions and studied systematically the dependence of the detected emission intensity on the polarizer settings for samples of varying anisotropy. This includes a dispersion of a spherical quantum dot (QD) with an ideally isotropic emission, a solution of a common small organic dye in a fluid solvent as well as dispersions of elongated quantum dot rods (QDR) with an anisotropic luminescence and a small organic dye in a rigid polymeric matrix, as ideally anisotropic emitter. Our results show that for instruments lacking polarizers, anisotropy-related measurement uncertainties of relative photoluminescence quantum yields can amount to more than 40%, with the size of these systematic errors depending on the difference in emission anisotropy between the sample and the standard. KW - Photoluminescence KW - Quantum Yield KW - Emission Anisotropy KW - Quantum Dot Rod KW - Quantum Dot KW - Dye PY - 2015 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-325240 DO - https://doi.org/10.1515/zpch-2014-0626 SN - 0942-9352 SN - 2196-7156 SN - 0044-3336 SN - 0044-3328 VL - 229 IS - 1-2 SP - 153 EP - 165 PB - Oldenbourg CY - München AN - OPUS4-32524 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Matzen, Melissa A1 - Kandola, B. A1 - Huth, Christian A1 - Schartel, Bernhard T1 - Influence of flame retardants on the melt dripping behaviour of thermoplastic polymers N2 - Melt flow and dripping of the pyrolysing polymer melt can be both a benefit and a detriment during a fire. In several small-scale fire tests addressing the ignition of a defined specimen with a small ignition source, well-adjusted melt flow and dripping are usually beneficial to pass the test. The presence of flame retardants often changes the melt viscosity crucially. The influence of certain flame retardants on the dripping behaviour of four commercial polymers, poly(butylene terephthalate) (PBT), polypropylene (PP), polypropylene modified with ethylene-propylene rubber (PP-EP) and polyamide 6 (PA 6), is analysed based on an experimental monitoring of the mass loss due to melt dripping, drop size and drop temperature as a function of the furnace temperature applied to a rod-shaped specimen. Investigating the thermal transition (DSC), thermal and thermo-oxidative decomposition, as well as the viscosity of the polymer and collected drops completes the investigation. Different mechanisms of the flame retardants are associated with their influence on the dripping behaviour in the UL 94 test. Reduction in decomposition temperature and changed viscosity play a major role. A flow limit in flame-retarded PBT, enhanced decomposition of flame-retarded PP and PP-EP and the promotion of dripping in PA 6 are the salient features discussed. KW - Fire retardant KW - Viscosity KW - Melt dripping KW - Reaction-to-small-flame KW - UL 94 PY - 2015 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-338941 DO - https://doi.org/10.3390/ma8095267 SN - 1996-1944 VL - 8 IS - 9 SP - 5621 EP - 5646 PB - MDPI CY - Basel AN - OPUS4-33894 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Sötebier, Carina A1 - Bierkandt, Frank A1 - Rades, Steffi A1 - Jakubowski, Norbert A1 - Panne, Ulrich A1 - Weidner, Steffen T1 - Sample loss in asymmetric flow field-flow fractionation coupled to inductively coupled plasma-mass spectrometry of silver nanoparticles N2 - In this work, sample losses of silver nanoparticles (Ag NPs) in asymmetrical flow field-flow fractionation (AF4) have been systematically investigated with the main focus on instrumental conditions like focusing and cross-flow parameters as well as sample concentration and buffer composition. Special attention was drawn to the AF4 membrane. For monitoring possible silver depositions on the membrane, imaging laser ablation coupled to inductively coupled plasma mass spectrometry (LA-ICP-MS) was used. Our results show that the sample residue on the membrane was below 0.6% of the total injected amount and therefore could be almost completely avoided at low sample concentrations and optimized conditions. By investigation of the AF4 flows using inductively coupled plasma mass spectrometry (ICP-MS), we found the recovery rate in the detector flow under optimized conditions to be nearly 90%, while the cross-flow, slot-outlet flow and purge flow showed negligible amounts of under 0.5%. The analysis of an aqueous ionic Ag standard solution resulted in recovery rates of over 6% and the ionic Ag content in the sample was found to be nearly 8%. Therefore, we were able to indicate the ionic Ag content as the most important source of sample loss in this study. KW - Asymmetric flow filed-flow fractionation KW - ICP-MS KW - Nanoparticles KW - Sample loss KW - Quantification PY - 2015 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-336171 DO - https://doi.org/10.1039/c5ja00297d SN - 0267-9477 SN - 1364-5544 VL - 30 IS - 10 SP - 2214 EP - 2222 PB - Royal Society of Chemistry CY - London AN - OPUS4-33617 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Breßler, Ingo A1 - Pauw, Brian Richard A1 - Thünemann, Andreas T1 - McSAS: software for the retrieval of model parameter distributions from scattering patterns N2 - A user-friendly open-source Monte Carlo regression package (McSAS) is presented, which structures the analysis of small-angle scattering (SAS) using uncorrelated shape-similar particles (or scattering contributions). The underdetermined problem is solvable, provided that sufficient external information is available. Based on this, the user picks a scatterer contribution model (or 'shape') from a comprehensive library and defines variation intervals of its model parameters. A multitude of scattering contribution models are included, including prolate and oblate nanoparticles, core-shell objects, several polymer models, and a model for densely packed spheres. Most importantly, the form-free Monte Carlo nature of McSAS means it is not necessary to provide further restrictions on the mathematical form of the parameter distribution; without prior knowledge, McSAS is able to extract complex multimodal or odd-shaped parameter distributions from SAS data. When provided with data on an absolute scale with reasonable uncertainty estimates, the software outputs model parameter distributions in absolute volume fraction, and provides the modes of the distribution (e.g. mean, variance etc.). In addition to facilitating the evaluation of (series of) SAS curves, McSAS also helps in assessing the significance of the results through the addition of uncertainty estimates to the result. The McSAS software can be integrated as part of an automated reduction and analysis procedure in laboratory instruments or at synchrotron beamlines. KW - Nanotechnology KW - Nanoparticles KW - Small-angle X-ray scattering KW - SAXS PY - 2015 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-334396 DO - https://doi.org/10.1107/S1600576715007347 SN - 0021-8898 SN - 1600-5767 VL - 48 IS - 3 SP - 962 EP - 969 PB - Blackwell CY - Oxford AN - OPUS4-33439 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 - Klykov, Oleg A1 - Weller, Michael G. T1 - Quantification of N-hydroxysuccinimide and N-hydroxysulfosuccinimide by hydrophilic interaction chromatography (HILIC) N2 - N-Hydroxysuccinimide (NHS) esters are the most important activated esters used in many different bioconjugation techniques, such as protein labelling by fluorescent dyes and enzymes, surface activation of chromatographic supports, microbeads, nanoparticles, and microarray slides, and also in the chemical synthesis of peptides. Usually, reactions with NHS esters are very reliable and of high yield, however, the compounds are sensitive to air moisture and water traces in solvents. Therefore, the quantification of NHS would be a very helpful approach to identify reagent impurities or degradation of stored NHS esters. No robust and sensitive method for the detection of NHS (or the more hydrophilic sulfo-NHS) has been reported yet. Here, a chromatographic method based on HILIC conditions and UV detection is presented, reaching a detection limit of about 1 mg L-1, which should be sensitive enough for most of the applications mentioned above. Exemplarily, the hydrolytic degradation of a biotin-NHS ester and a purity check of a fluorescent dye NHS ester are shown. An important advantage of this approach is its universality, since not the structurally variable ester compound is monitored, but the constant degradation product NHS or sulfo-NHS, which avoids the necessity to optimize the separation conditions and facilitates calibration considerably. KW - NHS KW - Sulfo-NHS KW - NHS-Ester KW - Qualitätskontrolle KW - Reinheitsbestimmung KW - HPLC PY - 2015 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-337833 DO - https://doi.org/10.1039/c5ay00042d SN - 1759-9660 SN - 1759-9679 VL - 7 IS - 15 SP - 6443 EP - 6448 PB - RSC Publ. CY - Cambridge AN - OPUS4-33783 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Guo, Y. A1 - Lippitz, Andreas A1 - Saftien, P. A1 - Unger, Wolfgang A1 - Kemnitz, E. T1 - Tuning the surface properties of novel ternary iron(III) fluoride-based catalysts using the template effect of the matrix N2 - Sol–gel prepared ternary FeF3–MgF2 materials have become promising heterogeneous catalysts due to their porosity and surface Lewis/Brønsted acidity (bi-acidity). Despite the good catalytic performance, nanoscopic characterisations of this type of material are still missing and the key factors controlling the surface properties have not yet been identified, impeding both a better understanding and further development of ternary fluoride catalysts. In this study, we characterised the interaction between the bi-acidic component (FeF3) and the matrix (MgF2) on the nano-scale. For the first time, the formation pathway of FeF3–MgF2 was profiled and the template effect of MgF2 during the synthesis process was discovered. Based on these new insights two novel materials, FeF3–CaF2 and FeF3–SrF2, were established, revealing that with decreasing the atomic numbers (from Sr to Mg), the ternary fluorides exhibited increasing surface acidity and surface area but decreasing pore size. These systematic changes gave rise to a panel of catalysts with tuneable surface and bulk properties either by changing the matrix alkaline earth metal fluoride or by adjusting their ratios to Fe or both. The template effect of the alkaline earth metal fluoride matrix was identified as the most probable key factor determining the surface properties and further influencing the catalytic performance in ternary fluoride based catalysts, and paves the way to targeted design of next-generation catalysts with tunable properties. KW - Catalysis KW - Surface analysis KW - XPS PY - 2015 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-327410 DO - https://doi.org/10.1039/c4dt03229b SN - 1477-9226 SN - 1477-9234 SN - 1364-5447 VL - 44 IS - 11 SP - 5076 EP - 5085 PB - RSC CY - Cambridge AN - OPUS4-32741 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Krankenhagen, Rainer A1 - Maierhofer, Christiane T1 - Einzelblitz vs. Multiblitz - Blitzthermografie mit mehreren Blitzen N2 - Die Blitzthermografie weist eine Reihe von Vorteilen gegenüber anderen Verfahren der aktiven Thermografie auf und hat daher eine relativ große Verbreitung in Forschung und Industrie gefunden. Ein wesentlicher Nachteil ist jedoch die begrenzte Energie, die pro Blitz genutzt werden kann. Es stellt sich die Frage, ob sich durch mehrere kurz hintereinander ausgeführte Blitze eine Verbesserung des Energieeintrags erreichen lässt. Zur experimentellen Untersuchung dieser Frage wurde ein Versuchsstand mit vier Blitzlampen so umgerüstet, dass die Blitzlampen zeitgleich oder nacheinander mit einer regelbaren Verzögerung ausgelöst werden können („Multiblitz“). Als Probekörper dienten Platten aus CFK, an deren Rückseite Flachbodenbohrungen (FBB) eingebracht worden waren. Betrachtet wurde jedoch nur der absolute Temperaturhub am ungestörten Material. Die Experimente zeigen relativ geringe Effekte im Prozentbereich, wie sie auch gemäß einer quantitativen Abschätzung zu erwarten sind. Interessanterweise vergrößerte sich der Einfluss der Multiblitzanregung auf die Energieeinkopplung deutlich bei einem etwas vergrößerten Abstand zwischen Blitzlampen und untersuchter Oberfläche. Die Ursache für diesen Effekt ist derzeit unklar, vermutet werden eine Temperaturabhängigkeit und/oder eine Abstandsabhängigkeit des Wärmübergangskoeffizienten im Konvektionsterm. T2 - Thermographie-Kolloquium 2015 CY - Leinfelden-Echterdingen, Germany DA - 01.10.2015 KW - Thermografie KW - Blitzthermografie KW - Konvektion KW - Wärmeverluste KW - Einkoppeleffizienz KW - Energiekopplung PY - 2015 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-345487 SN - 978-3-940283-74-0 VL - 154 SP - 1 EP - 8 PB - Deutsche Gesellschaft für Zerstörungsfreie Prüfung (DGZfP) CY - Berlin AN - OPUS4-34548 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Maierhofer, Christiane A1 - Röllig, Mathias A1 - Ehrig, Karsten A1 - Meinel, Dietmar T1 - Validierung der aktiven Thermografie mittels CT zur Charakterisierung von Inhomogenitäten und Fehlstellen in CFK N2 - Aktive Thermografieverfahren werden immer häufiger zur zerstörungsfreien Prüfung von Faserverbundwerkstoffen eingesetzt, da diese völlig berührungslos arbeiten und sowohl zur Prüfung großflächiger Strukturen als auch von großen Stückzahlen kleinerer Komponenten in der Fertigung eingesetzt werden können. Dieser Beitrag beschäftigt sich mit Untersuchungen an typischen Defekten und Inhomogenitäten, die bereits während der Fertigung von CFK Bauteilen entstehen oder unbeabsichtigt mit eingebaut werden. Systematische Untersuchungen wurden mit Blitzthermografie in Reflexions- und Transmissionskonfiguration und mit Computertomographie (CT) durchgeführt. Die CT wurde dabei als Referenzverfahren genutzt, da dieses Verfahren auch kleinere Defekte mit relativ hoher Ortsauflösung und unabhängig von der Tiefe darstellen kann. T2 - DACH-Jahrestagung 2015 CY - Salzburg, Austria DA - 11.05.2015 KW - Aktive Thermografie KW - Computer Tomographie KW - Aluminium Druckguss KW - Poren KW - Validierung PY - 2015 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-345251 SN - 978-3-940283-68-9 IS - DGZfP BB 152 SP - Mi.3.C.1, 1 EP - 8 PB - Deutsche Gesellschaft für Zerstörungsfreie Prüfung (DGZfP) AN - OPUS4-34525 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Rothbart, Nick A1 - Maierhofer, Christiane A1 - Röllig, Mathias A1 - Sengebusch, M. A1 - Goldammer, M. A1 - Hohlstein, F. A1 - Koch, J. A1 - Kryukov, I. A1 - Mahler, G. A1 - Stotter, B. A1 - Walle, G. T1 - Ringversuche zur Blitzthermografie N2 - Im Rahmen des INS-Projekts „Durchführung von Ringversuchen zur Normung und Standardisierung der aktiven Thermografie mit Blitzlichtanregung“ wurden Ringversuche durchgeführt, die die Zuverlässigkeit, Vergleichbarkeit und Effektivität der Blitzthermografie für unterschiedliche Prüfprobleme nachweisen sollten. Weiterhin sollten diese Untersuchungen als Methodenvalidierungsstudie die Richtigkeit und Präzision der Blitzthermografie nachweisen und Vergleichsinformationen unterschiedlicher Geräteausstattungen liefern. Im Normausschuss NA 062-08-27 AA „Visuelle und thermografische Prüfung“ des DIN werden die Ergebnisse die Erarbeitung eines Normentwurfs zur Blitzthermografie unterstützen. In diesem Beitrag werden die Ringversuche beschrieben und ausgewählte Ergebnisse präsentiert. T2 - Thermographie-Kolloquium 2015 CY - Leinfelden-Echterdingen, Germany DA - 01.10.2015 KW - Thermografie mit Blitzanregung KW - Ringversuch KW - Testkörper KW - Standardisierung KW - Signal-zu-Rausch-Verhältnis PY - 2015 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-345460 SN - 978-3-940283-74-0 IS - DGZfP BB 154 SP - Vortrag 12, 1 EP - 8 AN - OPUS4-34546 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Maiwald, Michael A1 - Sperling, M. A1 - Huber, C. A1 - Hayen, H. A1 - Teutenberg, T. A1 - Belder, D. A1 - Karst, U. A1 - Hagenhoff, B. A1 - Vogel, M. T1 - Prozessanalytik: Spektroskopie und Miniaturisierung N2 - Forderungen nach höherer Geschwindigkeit und die Komplexität der Fragen geben der analytischen Chemie neue Impulse. So nutzt die Prozessanalytik gepulste Ramanspektrometer, die Elemente Arsen und Quecksilber dominieren die Forschung in der Speziesanalytik, und die Omics-Techniken entwickeln sich zu Multi-Omics-Ansätzen. Ambiente MS-Techniken benötigen keine aufwendige Probenvorbereitung, multidimensionale Trenntechniken werden verstärkt in der Routine eingesetzt, und Chip-basierte Trennungen fallen durch Schnelligkeit auf. Molekülspektroskopie und Massenspektrometrie dominieren die bildgebenden Verfahren, und die Lateralauflösung der ToF-Sekundärionenmassenspektrometrie hat sich bei Oberflächenuntersuchungen verbessert. KW - Prozessanalytik KW - Quanten-Kaskadenlaser KW - Photonendichtewellen-Spektroskopie KW - Gepulste Ramanspektrometer KW - Partikelmesstechnik KW - Prozesssensoren PY - 2016 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-361371 UR - http://onlinelibrary.wiley.com/doi/10.1002/nadc.20164046080/abstract DO - https://doi.org/10.1002/nadc.20164046080 SN - 1868-0054 VL - 64 IS - 5 SP - 497 EP - 508 PB - Wiley-VCH Verlag GmbH & Co. KGaA CY - Weinheim AN - OPUS4-36137 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Maack, Stefan A1 - Holst, R. T1 - Rekonstruktion des Bestandsplans im Zuge der Nachrechnung der Brücke über die Leine bei Schwarmstedt N2 - Der aktuell im Rahmen der Nachrechnungsrichtlinie geforderte Nachweis von Tragfähigkeit, Gebrauchstauglichkeit und Ermüdung der Brückenbauwerke im Bestand der Länder und des Bundes stellt eine enorme Herausforderung dar. Insbesondere bei unvollständigen oder fehlenden Bestandsplänen der Bauwerke sind Maßnahmen erforderlich, um die erforderlichen Informationen zu beschaffen. Ein wirkungsvolles Instrument können hierfür die zerstörungsfreien Prüfverfahren des Bauwesens sein. In dem präsentierten Forschungsprojekt erfolgte die Rekonstruktion eines Bestandsplanes direkt auf die Anforderungen des mit der Nachrechnung beauftragten Ingenieurbüros. Darüber hinaus wurde der Entwurf eines Leitfadens erstellt, der im Falle von unvollständigen oder fehlenden Bestandsplänen die Grundlagen für die Beauftragung und Durchführung der Nachrechnung schafft. T2 - Fachtagung Bauwerksdiagnose 2016 - Praktische Anwendungen Zerstörungsfreier Prüfungen und Zukunftsaufgaben CY - Berlin, Germany DA - 25.02.2016 KW - Zerstörungsfreie Prüfung KW - Nachrechnungsrichtlinie KW - Brücken PY - 2016 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-388355 UR - http://www.bauwerksdiagnose2016.de/Portals/bwd2016/BB/vortrag%206.pdf SP - 1 EP - 14 PB - Deutsche Gesellschaft für zerstörungsfreie Prüfung e.V. CY - Berlin AN - OPUS4-38835 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Fedelich, Bernard A1 - Kühn, Hans-Joachim A1 - Rehmer, Birgit A1 - Skrotzki, Birgit ED - Iacoviello, Francesco T1 - Modeling the lifetime reduction due to the superposition of TMF and HCF loadings in cast iron alloys N2 - The superposition of small amplitude, high frequency loading cycles (HCF) to slow, large amplitude loading cycles (TMF) can significantly reduce the fatigue life. In this work, the combined TMF+HCF loading has been experimentally investigated for a cast iron alloy. In particular, the influence of the HCF frequency of the HCF amplitude and of the location of the superposed HCF cycles has been assessed. It was observed that the HCF frequency has a limited impact on the TMF fatigue life. On the other side, the HCF-strain amplitude has a highly non-linear influence on the TMF fatigue life. A simple estimate for the fatigue life reduction due to the superposed HCF cycles has been derived from fracture mechanics considerations. It is assumed that the number of propagation cycles up to failure can be neglected after a threshold for the HCF loading has been reached. The model contains only two adjustable parameters and can be combined with any TMF life prediction model. The model predictions are compared with the test results for a large range of TMF+HCF loading conditions. T2 - 21st European Conference on Fracture, ECF21 CY - Catania, Italy DA - 20.06.2016 KW - Thermomechanical Fatigue (TMF); High Cycle Fatigue (HCF); Cast iron; Fatigue assessment PY - 2016 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-369550 DO - https://doi.org/doi:10.1016/j.prostr.2016.06.274 VL - 2 SP - 2190 EP - 2197 PB - Elsevier CY - Radarweg 29, 1043 NX Amsterdam, The Netherlands, AN - OPUS4-36955 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Casperson, Ralf A1 - Knöppchen, Andreas A1 - Pohl, Rainer A1 - Zimne, Lutz A1 - Bode, Johannes A1 - Hollesch, Martin T1 - Manufacturing of reference defects for NDT using low-energy EDM N2 - For non-destructive testing (NDT) appropriate reference blocks are required in order to verify and calibrate a testing procedure. At BAM a special electric discharge machining (EDM) system has been developed which is able to manufacture artificial defects having a width down to 30 μm. Especially in the case of austenitic materials conventional EDM leads to a transformation of austenite to martensite. The martensite transformation causes a higher sensitivity of electromagnetic NDT methods (e. g. eddy current testing) at the artificial defects compared to natural defects of same size. The EDM system developed at BAM uses very low energy to avoid this material transformation. A side effect of the low-energy EDM is a lower surface roughness compared to conventional EDM. The artificial defects manufactured at BAM are measured optically and delivered with a certificate. A comparison of artificial defects shows the influence of material transformation on NDT and how differently the quality of the artificial defects can be. T2 - 19th World Conference on Non-Destructive Testing CY - Munich, Germany DA - 13.06.2016 KW - Reference defect KW - EDM KW - Electric discharge machining KW - Artificial defect PY - 2016 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-365995 SN - 978-3-940283-78-8 VL - 157 SP - 1 EP - 10 PB - German Society for Non-Destructive Testing (DGZfP e.V.) CY - Berlin, Germany AN - OPUS4-36599 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Simon, Franz-Georg A1 - Holm, Olaf T1 - Reduction of natural resource use by improving resource efficiency N2 - In 2011, the German Association of Engineers (VDI) started working on a set of guidelines dealing with the improvement of resource efficiency. These guidelines represent a framework that defines resource efficiency and outlines proposals for the producing industry. A special guideline for small and medium-sized enterprises (SMEs) is included as well as guidelines on methodologies for evaluating resource use indicators, such as the cumulative raw material demand of products and production systems. The work on resource use indicators is still in progress. The evaluation of raw materials expenditure will include water, soil and land use. The model will include the availability of raw materials (criticality). Improving resource efficiency at the end-of-life stage is illustrated in this paper by the example of materials recovery from waste, here from residues out of municipal solid waste incineration (MSWI). With mechanical treatment valuable materials like ferrous and non-ferrous metals and secondary construction material can be extracted from MSWI bottom ash. The potential contribution on the resource efficiency is discussed. KW - Resource efficiency KW - Raw material equivalent KW - Mechanical treatment KW - Bottom ash KW - Waste incineration KW - Secondary raw materials KW - Product life cycle PY - 2016 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-356490 UR - http://www.hrpub.org/journals/jour_archive.php?id=62&iid=877 DO - https://doi.org/10.13189/ ujms.2016.040302 SN - 2331-6691 SN - 2331-6705 VL - 4 IS - 3 SP - 54 EP - 59 PB - Horizon Research Publishing CY - Alhambra, CA, USA AN - OPUS4-35649 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kästner, Claudia A1 - Thünemann, Andreas T1 - Catalytic reduction of 4-nitrophenol using silver nanoparticles with adjustable activity N2 - We report on the development of ultra-small core-shell silver nanoparticles synthesized by an up-scaled modification of the polyol process. It is foreseen to use these thoroughly characterized particles as reference material to compare the catalytic and biological properties of functionalized silver nanoparticles. Small-angle X-ray scattering (SAXS) analysis reveal a narrow size distribution of the silver cores with a mean radius of RC = 3.0 nm and a distribution width of 0.6 nm. Dynamic light scattering (DLS) provides a hydrodynamic radius of RH = 10.0 nm and a PDI of 0.09. The particles’ surface is covered with poly(acrylic acid) (PAA) forming a shell with a thickness of 7.0 nm, which provides colloidal stability lasting for more than six months at ambient conditions. The PAA can be easily exchanged by biomolecules to modify the surface functionality. Replacements of PAA with glutathione (GSH) and bovine serum albumin (BSA) have been performed as examples. We demonstrate that the particles effectively catalyze the reduction of 4-nitrophenol to 4-aminophenol with sodium borohydride. With PAA as stabilizer, the catalytic activity of 436 ± 24 L g⁻¹ s⁻¹ is the highest reported in literature for silver nanoparticles. GSH and BSA passivate the surface substantially resulting in a catalytic activity of 77.6 ± 0.9 and 3.47 ± 0.50 L g⁻¹ s⁻¹, respectively. KW - Silver nanoparticles KW - Catalysis KW - Reference material KW - Protein coating PY - 2016 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-370655 DO - https://doi.org/10.1021/acs.langmuir.6b01477 SN - 0743-7463 SN - 1520-5827 VL - 32 IS - 29 SP - 7383 EP - 7391 AN - OPUS4-37065 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Fuhrmann, A. A1 - Göstl, R. A1 - Wendt, R. A1 - Kötteritzsch, J. A1 - Hager, M. D. A1 - Schubert, U. S. A1 - Brademann-Jock, Kerstin A1 - Thünemann, Andreas A1 - Nöchel, U. A1 - Behl, M. A1 - Hecht, S. T1 - Conditional repair by locally switching the thermal healing capability of dynamic covalent polymers with light N2 - Healable materials could play an important role in reducing the environmental footprint of our modern technological society through extending the life cycles of consumer products and constructions. However, as most healing processes are carried out by heat alone, the ability to heal damage generally kills the parent material’s thermal and mechanical properties. Here we present a dynamic covalent polymer network whose thermal healing ability can be switched ‘on’ and ‘off’ on demand by light, thereby providing local control over repair while retaining the advantageous macroscopic properties of static polymer networks. We employ a photoswitchable furan-based crosslinker, which reacts with short and mobile maleimidesubstituted poly(lauryl methacrylate) chains forming strong covalent bonds while simultaneously allowing the reversible, spatiotemporally resolved control over thermally induced de- and re-crosslinking. We reason that our system can be adapted to more complex materials and has the potential to impact applications in responsive coatings, photolithography and microfabrication. KW - Small-angle X-ray scattering KW - SAXS KW - Polymer PY - 2016 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-386689 DO - https://doi.org/10.1038/ncomms13623 SN - 2041-1723 VL - 7 SP - Article 13623, 1 EP - 7 PB - NATURE PUBLISHING GROUP CY - MACMILLAN BUILDING, 4 CRINAN ST, LONDON N1 9XW, ENGLAND AN - OPUS4-38668 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Liebig, F. A1 - Thünemann, Andreas A1 - Koetz, J. T1 - Ostwald Ripening Growth Mechanism of Gold Nanotriangles in Vesicular Template Phases N2 - The mechanism of nanotriangle formation in multivesicular vesicles (MMV) is investigated by using time-dependent SAXS measurements in combination with UV−vis spectroscopy, light, and transmission electron microscopy. In the first time period 6.5 nm sized spherical gold nanoparticles are formed inside of the vesicles, which build up soft nanoparticle aggregates. In situ SAXS experiments show a linear increase of the volume and molar mass of nanotriangles in the second time period. The volume growth rate of the triangles is 16.1 nm3/min, and the growth rate in the vertical direction is only 0.02 nm/min. Therefore, flat nanotriangles with a thickness of 7 nm and a diameter of 23 nm are formed. This process can be described by a diffusionlimited Ostwald ripening growth mechanism. TEM micrographs visualize soft coral-like structures with thin nanoplatelets at the periphery of the aggregates, which disaggregate in the third time period into nanotriangles and spherical particles. The 16 times faster growth of nanotriangles in the lateral than that in the vertical direction is related to the adsorption of symmetry breaking components, i.e., AOT and the polyampholyte PalPhBisCarb, on the {111} facets of the gold nanoplatelets in combination with confinement effects of the vesicular template phase. KW - Gold KW - Nanoparticle KW - Small-angle x-ray scattering KW - SAXS KW - Kinetics PY - 2016 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-379261 DO - https://doi.org/10.1021/acs.langmuir.6b02662 SN - 0743-7463 VL - 32 IS - 42 SP - 10928 EP - 10935 PB - American Chemical Society AN - OPUS4-37926 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Meyer, Klas A1 - Kern, Simon A1 - Zientek, Nicolai A1 - Guthausen, G. A1 - Maiwald, Michael T1 - Process control with compact NMR N2 - Compact nuclear magnetic resonance (NMR) instruments make NMR spectroscopy and relaxometry accessible in industrial and harsh environments for reaction and process control. An increasing number of applications are reported. To build an interdisciplinary bridge between “process control” and “compact NMR”,we give a short overviewon current developments in the field of process Engineering such as modern process design, integrated processes, intensified processes along with requirements to process control, model based control, or soft sensing. Finally, robust field integration of NMR systems into processes environments, facing explosion protection or Integration into process control systems, are briefly discussed. KW - Prozessanalytik KW - Quantitative NMR-Spektroskopie KW - Industrie 4.0 KW - Reaction monitoring KW - Process control KW - Online NMR spectroscopy KW - Compact NMR PY - 2016 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-373562 UR - http://www.sciencedirect.com/science/article/pii/S0165993616300073 DO - https://doi.org/10.1016/j.trac.2016.03.016 SN - 0165-9936 VL - 83 IS - Part A / SI SP - 39 EP - 52 PB - Elsevier AN - OPUS4-37356 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Guhl, Svetlana A1 - Meyer, Klas A1 - Kern, Simon A1 - Gräßer, Patrick A1 - Maiwald, Michael ED - Maiwald, Michael T1 - Process monitoring of an intensified continuous production unit with compact NMR spectroscopy N2 - Monitoring chemical reactions is the key to chemical process control. Today, mainly optical online methods are applied. NMR spectroscopy has a high potential for direct loop process control. Compact NMR instruments based on permanent magnets are robust and relatively inexpensive analyzers, which feature advantages like low cost, low maintenance, ease of use, and cryogen-free operation. Instruments for online NMR measurements equipped with a flow-through cell, possessing a good signal-to-noise-ratio, sufficient robustness, and meeting the requirements for integration into industrial plants (i.e., explosion safety and fully automated data analysis) are cur-rently not available off the rack. Recently, promising benchtop NMR instruments with acceptable performance came to market and process integrated sensors developed on basis of such laboratory instruments are on their way. T2 - 12. Kolloquium des Arbeitskreises Prozessanalytik CY - Berlin, Germany DA - 28.11.2016 KW - Online NMR spectroscopy KW - Modular production units KW - Low field NMR spectroscopy PY - 2016 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-383646 SP - P17, 75 EP - 77 AN - OPUS4-38364 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Schmidt, Birgit Angelika A1 - Ziemann, M. A A1 - Pentzien, Simone A1 - Gabsch, T. A1 - Koch, W. A1 - Krüger, Jörg T1 - Technical analysis of a Central Asian wall painting detached from a Buddhist cave temple on the northern Silk Road N2 - A great number of Central Asian wall paintings, archeological materials, architectural fragments, and textiles, as well as painting fragments on silk and paper, make up the so called Turfan Collection at the Asian Art Museum in Berlin. The largest part of the collection comes from the Kucha region, a very important cultural center in the third to ninth centuries. Between 1902 and 1914, four German expeditions traveled along the northern Silk Road. During these expeditions, wall paintings were detached from their original settings in Buddhist cave complexes. This paper reports a technical study of a wall painting, existing in eight fragments, from the Buddhist cave no. 40 (Ritterhöhle). Its original painted surface is soot blackened and largely illegible. Grünwedel, leader of the first and third expeditions, described the almost complete destruction of the rediscovered temple complex and evidence of fire damage. The aim of this case study is to identify the materials used for the wall paintings. Furthermore, soot deposits as well as materials from conservation interventions were of interest. Non-invasive analyses were preferred but a limited number of samples were taken to provide more precise information on the painting technique. By employing optical and scanning electron microscopy, energy dispersive X-ray spectroscopy, micro X-ray fluorescence spectroscopy, X-ray diffraction analysis, and Raman spectroscopy, a layer sequence of earthen render, a ground layer made of gypsum, and a paint layer containing a variety of inorganic pigments were identified. KW - Wall paintings KW - Central Asia KW - Silk Road KW - Pigments KW - Microscopy PY - 2016 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-357297 DO - https://doi.org/10.1179/2047058414Y.0000000152 VL - 61 IS - 2 SP - 113 EP - 122 PB - Routledge Taylor & Francis Group CY - London AN - OPUS4-35729 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hosseini, Seyed M.H. A1 - Ségur, D. A1 - Boehm, Rainer A1 - Gohlke, Dirk A1 - Heckel, Thomas A1 - Riemer, S. A1 - Brackrock, Daniel A1 - Gaal, Mate T1 - Characterization and optimization of ultrasonic tests for inspection of fiber-reinforced plastic composites in energy related applications N2 - Applications of fibre reinforced plastic (FRP) composites in modern industries are increasing due to their considerable advantages such as light weight and excellent mechanical properties. Accordingly, importance of operational safety of modern structures made of advanced composites by ensuring the material quality has led to increasing demands for development of non-destructive evaluation (NDE) systems. In the context of a European project entitled “Validated Inspection Techniques for Composites in Energy Applications” (VITCEA), the aim is to develop and validate traceable procedures for novel NDE techniques with contrasting damage detection capabilities in energy related applications such as wind and marine turbine blades, nacelles, oil and gas flexible risers. Accordingly, VITCEA focuses on optimization of ultrasonic tests (UTs) for quantitative defect detection and quality characterization of FRP structures. In this context, the present study describes the ultrasound field in heterogeneous composite materials. The theoretical predictions are compared with simulation results obtained from CIVA a software package dedicated to NDT simulations based on the asymptotic ray theory. T2 - WCNDT 2016 - - 19th World Conference on Non-Destructive Testing CY - München DA - 13.06.2016 KW - Ultrasonic tests KW - Composite KW - Wave propagation KW - Analytical approach PY - 2016 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-356398 SP - We.4.D.5, 1 EP - 8 AN - OPUS4-35639 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 - Armatys, Kamila A1 - Miller, M. T1 - Knudsen effusion mass spectrometry studies on metal halides performed in 1990-2014 N2 - Abstract Investigations on metal halide systems carried out by Knudsen effusion mass spectrometry in the period 1990-2014 are reviewed in the present paper.163 original papers were published focused on metal halides showing still considerable activity in this area. The fundamentals of the Knudsen effusion mass spectrometry method and thermodynamic background of the investigation are briefly reported. Data to the system studied, temperature ranges, Knudsen cell materials, vapor species identified in the equilibrium vapors and the thermodynamic properties obtained in the study are presented. The important issues of metal halide vaporization studies are briefly discussed and commented. The studies of the vaporization of metal halogens by Knudsen effusion mass spectrometry aimed firstly atthe determination of gaseous complexes species in the vapor and determination of its thermodynamic data like sublimation enthalpy etc. and secondly at the determination of negative ions formation and various ion-molecule equilibria reactions of metal halide systems. Many of the studied materials have a crucial role for modern technologies, for example metal halide lamps, hot corrosion caused by halide salts, phosphorus recovery technologies or gas assisted separation of lanthanides. The investigation of such systems gives information on mechanisms of vaporization, volatility of the systems under various conditions (temperature, pressure etc.), reactivity, thermal stability, resistance etc. that could be further applied for various calculations and to predict the behavior of various components under various technological aspects. KW - Metal halides KW - Knudsen Effusion Mass Spectrometry (KEMS) KW - HTMS KW - Thermochemistry KW - High temperature KW - Vaporization PY - 2016 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-357126 SN - 2349-7092 VL - 3 IS - 1 SP - 68 EP - 93 PB - The Pharmaceutical and Chemical Journal CY - Kundlawala, India AN - OPUS4-35712 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schadow, Florian A1 - Gaal, Mate A1 - Bartusch, Jürgen A1 - Dohse, E. A1 - Köppe, Enrico T1 - Focusing air-coupled ultrasonic transducers based on ferroelectrets N2 - Rising importance of composite lightweight structures in aircraft and automobile industries increases the demand on reliable non-destructive testing methods for these structures. Air-coupled ultrasonic testing emerged to suit these requirements as it does not require any liquid coupling medium. In conventional air-coupled ultrasonic transducers, matching layers are used in order to decrease the impedance mismatch between transducer and air. Matching layers can be omitted by using ferroelectrets, which are charged cellular polymers having ferroelectric and piezoelectric properties. Especially a low Young’s modulus, low density and low sound velocity of cellular polypropylene (cPP) are properties being required for well-matched air-coupled ultrasonic transducers. In our contribution we show recent enhancements of cPP transducers resulting in focused sound fields and thus improved lateral sensitivity. The influence of different transmitter apertures was evaluated using measurements of the emitted sound field. Further we show a transmission of a test specimen of carbon-fiber-reinforced plastic (CFRP) containing artificial damages. Results of focused transducers were compared to planar ferroelectret transducers, as well as to conventional air-coupled transducers. T2 - 19th World Conference on Non-Destructive Testing 2016 CY - München, Germany DA - 13.06.2016 KW - Air-coupled ultrasonic testing KW - Ferroelectrets KW - Cellular polypropylene KW - Focused sound fields KW - Focused transducers PY - 2016 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-355116 UR - http://www.ndt.net/search/docs.php3?showForm=off&id=19453 SP - 1 EP - 8 AN - OPUS4-35511 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Wilke, Manuel A1 - Klimakow, Maria A1 - Rademann, K. A1 - Emmerling, Franziska T1 - Fast and efficient synthesis of a host guest system: a mechanochemical approach N2 - An unusually fast and effective synthesis procedure for a host guest system consisting of a metal organic framework (MOF) and a polyoxometalate (POM) is described. The material was synthesised mechanochemically and the evolution of the structure was monitored ex and in situ using synchrotron X-ray diffraction (XRD). KW - Mechanochemistry KW - MOF KW - in situ PY - 2016 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-354910 UR - http://pubs.rsc.org/en/Content/ArticleLanding/2016/CE/C5CE01868D#!divAbstract DO - https://doi.org/10.1039/C5CE01868D VL - 18 IS - 7 SP - 1096 EP - 1100 AN - OPUS4-35491 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Fasano, A. A1 - Woyessa, G. A1 - Stajanca, Pavol A1 - Markos, C. A1 - Stefani, A. A1 - Nielsen, K. A1 - Rasmussen, H. K. A1 - Krebber, Katerina A1 - Bang, O. T1 - Fabrication and characterization of polycarbonate microstructured polymer optical fibers for high-temperature-resistant fiber Bragg grating strain sensors N2 - Here we present the fabrication of a solid-core microstructured polymer optical fiber (mPOF) made of polycarbonate (PC), and report the first experimental demonstration of a fiber Bragg grating (FBG) written in a PC optical fiber. The PC used in this work has a glass transition temperature of 145°C. We also characterize the mPOF optically and mechanically, and further test the sensitivity of the PC FBG to strain and temperature. We demonstrate that the PC FBG can bear temperatures as high as 125°C without malfunctioning. In contrast, polymethyl methacrylate-based FBG technology is generally limited to temperatures below 90°C. KW - Fiber optics sensors KW - Fiber Bragg gratings KW - Microstructured fibers KW - Fiber characterization KW - Polymers PY - 2016 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-355591 DO - https://doi.org/10.1364/OME.6.000649 SN - 2159-3930 VL - 6 IS - 2 SP - 649 EP - 659 PB - OSA Publishig AN - OPUS4-35559 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Hodoroaba, Vasile-Dan A1 - Rades, Steffi A1 - Salge, T. A1 - Mielke, Johannes A1 - Ortel, Erik A1 - Schmidt, R. T1 - Characterisation of nanoparticles by means of high-resolution SEM/EDS in transmission mode N2 - Advances in scanning electron microscopy (SEM) enable the high-resolution imaging of single nanoparticles (NPs) with sizes well below 10 nm. The SEM analysis in transmission mode (T-SEM) of NPs on thin film supports has many benefits when compared to the analysis of NPs on bulk substrates. The enhanced material (mass – thickness) contrast of the T-SEM imaging mode is well suited for in-depth and, particularly valuable, to very accurate, traceable, lateral dimensional measurements of NPs. Compared to samples prepared on bulk substrates, T-SEM with energy dispersive X-ray spectroscopy (EDS) achieves a drastically improved spatial resolution of the emitted X-rays. The poor signal-to-noise ratio of the X-ray spectra emitted by a single nanoparticle (NP) can be improved by the use of high-sensitivity (high collection solid angle) silicon drift (SDD), energy-dispersive X-ray spectrometers (EDS). The EDS spectral imaging of a single NP with a spatial resolution below 10 nm has become possible. This is demonstrated by means of various examples of nanostructures. Advanced data processing of T-SEM/EDS results sets the stage for the automated classification of NPs by feature analysis. This method combines the detection of morphological structures of interest by image processing of T-SEM micrographs with the chemical classification by EDS. T2 - European Microbeam Analysis Society’s 14th European Workshop on Modern Developments and Applications in Microbeam Analysis (EMAS 2015) CY - Portorož, Slovenia DA - 03.05.2015 KW - High-resolution KW - SEM KW - T-SEM KW - EDX KW - Nanoparticles PY - 2016 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-355628 UR - http://iopscience.iop.org/article/10.1088/1757-899X/109/1/012006 DO - https://doi.org/10.1088/1757-899X/109/1/012006 SN - 1757-899X VL - 109 SP - 012006-1 EP - 012006-12 PB - IOP Publishing Ltd CY - Bristol, UK AN - OPUS4-35562 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Dmitriev, A. I. A1 - Österle, Werner ED - Österle, Werner ED - Zhang, G. T1 - The role of solid lubricants for brake friction materials N2 - This review article comprises of three parts. Firstly, reports of brake manufacturers on the beneficial impact of solid lubricants for pad formulations are surveyed. Secondly, since tribofilms were identified to play a crucial role in friction stabilization and wear reduction, the knowledge about tribofilm structures formed during automotive braking was reviewed comprehensively. Finally, a model for simulating the sliding behavior of tribofilms is suggested and a review on modelling efforts with different model structures related to real tribofilms will be presented. Although the variety of friction composites involved in commercial brake systems is very broad, striking similarities were observed in respect to tribofilm nanostructures. Thus a generalization of the tribofilm nanostructure is suggested and prerequisites for smooth sliding performance and minimal wear rates have been identified. A minimum of 13 vol.% of soft inclusions embedded in an iron oxide based tribofilm is crucial for obtaining the desired properties. As long as the solid lubricants or their reaction products are softer than magnetite, the main constituent of the tribofilm, the model predicts smooth sliding and a minimum of wear. KW - Solid lubricant KW - Friction KW - Automotive braking KW - Tribofilm KW - Sliding simulation KW - MCA-modeling PY - 2016 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-355973 UR - www.mdpi.com/journal/lubricants DO - https://doi.org/10.3390/lubricants4010005 SN - 2075-4442 VL - 4 IS - 1 SP - 5 EP - 26 PB - MDPI CY - Basel, Switzerland AN - OPUS4-35597 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Lehmann, Jens A1 - Burkert, Andreas T1 - KorroPad - Beurteilung der Korrosionsbeständigkeit von Oberflächen nichtrostender Stähle N2 - Mit dem KorroPad Verfahren ist es dem Anwender möglich den Zustand der Passivschicht nichtrostender Stähle auf sehr einfache und schnelle Weise einschätzen zu können. Das Verfahren eignet sich dazu, den Grad der Passivität in Abhängigkeit der Umgebungsbedingungen und der Zeit nachzuvollziehen. Dies ermöglicht dem Anwender und Verarbeiter von nichtrostenden Stählen, die Lagerungsbedingungen und –zeiten einer frisch bearbeiteten Stahloberfläche zu ermitteln, welche für die Ausbildung einer stabilen Passivschicht notwendig sind, bevor diese risikoarm eingesetzt werden kann. Wie die hier dargestellten Beispiele und auch weitere zahlreiche praktische Anwendungen gezeigt haben, eignet sich das KorroPad ebenfalls für die Identifikation kritischer Prozessparameter bei der Verarbeitung nichtrostender Stähle. Mit dem Verfahren lassen sich viele prozessbedingte Einflussfaktoren auf die Oberflächengüte wie auch auf den Werkstoff charakterisieren. Aufgrund der schnellen und einfachen Auswertung der Prüfergebnisse können positive wie auch negative Veränderungen hinsichtlich der Passivschichtstabilität zügig erkannt werden. Dies ermöglicht es dem Anwender schnell zu reagieren, um kritische Einflüsse zu korrigieren und um eine Optimierung von Inhouse-Prozessen durchzuführen. Weitere Einsatzgebiete sind im Bereich der Wareneingangs- und/oder Warenausgangskontrolle denkbar, überall wo es um die Frage der Passivschichtstabilität einer nichtrostenden Stahloberfläche geht. T2 - Fachtagung Bauwerksdiagnose - Praktische Anwendungen Zerstörungsfreier Prüfungen und Zukunftsaufgaben CY - Berlin, Germany DA - 25.02.2016 KW - Korrosionsschnelltest, Nichtrostender Stahl, Passivschicht, KorroPad PY - 2016 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-355146 SN - 978-3-940283-77-1 VL - 157 SP - 1 EP - 7 PB - Deutsche Gesellschaft für zerstörungsfreie Prüfung (DGZfP) CY - Berlin AN - OPUS4-35514 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Steinkönig, J. A1 - Bloesser, F. R. A1 - Huber, B. A1 - Welle, A. A1 - Trouillet, V. A1 - Weidner, Steffen A1 - Barner, L. A1 - Roesky, P. W. A1 - Yuan, J. A1 - Goldmann, A. S. A1 - Barner-Kowollik, C. T1 - Controlled radical polymerization and in-depth mass-spectrometric characterization of poly(ionic liquid)s and their photopatterning on surfaces N2 - The preparation and characterization of poly(ionic liquid)s (PILs) bearing a polystyrene backbone via reversible addition fragmentation chain transfer (RAFT) polymerization and their photolithographic patterning on silicon wafers is reported. The controlled radical polymerization of the styrenic ionic liquid (IL) monomers ([BVBIM]X, X = Cl− or Tf2N−) by RAFT polymerization is investigated in detail. We provide a general synthetic tool to access this class of PILs with controlled molecular weight and relatively narrow molecular weight distribution (2000 g mol−1 ≤ Mn ≤ 10 000 g mol−1 with dispersities between 1.4 and 1.3 for p([BVBIM]Cl); 2100 g mol−1 ≤ MP ≤ 14 000 g mol−1 for p([BVBIM]Tf2N)). More importantly, we provide an in-depth characterization of the PILs and demonstrate a detailed mass spectrometric analysis via matrix-assisted laser desorption ionization (MALDI) as well as – for the first time for PILs – electrospray ionization mass spectrometry (ESI-MS). Importantly, p([BVBIM]Cl) and p([DMVBIM]Tf2N) were photochemically patterned on silicon wafers. Therefore, a RAFT agent carrying a photoactive group based on ortho-quinodimethane chemistry – more precisely photoenol chemistry – was photochemically linked for subsequent controlled radical polymerization of [BVBIM]Cl and [DMVBIM]Tf2N. The successful spatially-resolved photografting is evidenced by surface-sensitive characterization methods such as X-ray photoelectron spectroscopy (XPS) and time-of-flight secondary ion mass spectrometry (ToF-SIMS). The presented method allows for the functionalization of diverse surfaces with poly(ionic liquid)s. KW - reversible addition fragmentation chain transfer (RAFT) polymerization KW - polyionic liquids KW - mass spectrometry KW - surface modification PY - 2016 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-355202 DO - https://doi.org/10.1039/C5PY01320H VL - 7 SP - 451 EP - 461 PB - Royal Society of Chemistry CY - Cambridge AN - OPUS4-35520 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Tamschick, S. A1 - Rozenblut-Kościsty, B. A1 - Ogielska, M. A1 - Lehmann, Andreas A1 - Lymberakis, P. A1 - Hoffmann, F. A1 - Lutz, I. A1 - Kloas, W. A1 - Stöck, M. T1 - Sex reversal assessments reveal different vulnerability to endocrine disruption between deeply diverged anuran lineages N2 - Multiple anthropogenic stressors cause worldwide amphibian declines. Among several poorly investigated causes is global pollution of aquatic ecosystems with endocrine disrupting compounds (EDCs). These substances interfere with the endocrine system and can affect the sexual development of vertebrates including amphibians. We test the susceptibility to an environmentally relevant contraceptive, the artificial estrogen 17α-ethinylestradiol (EE2), simultaneously in three deeply divergent systematic anuran families, a model-species, Xenopus laevis (Pipidae), and two non-models, Hyla arborea (Hylidae) and Bufo viridis (Bufonidae). Our new approach combines synchronized tadpole exposure to three EE2-concentrations (50, 500, 5,000 ng/L) in a flow-through-system and pioneers genetic and histological sexing of metamorphs in non-model anurans for EDC-studies. This novel methodology reveals striking quantitative differences in genetic-male-to-phenotypic-female sex reversal in non-model vs. model species. Our findings qualify molecular sexing in EDC-analyses as requirement to identify sex reversals and state-of-the-art approaches as mandatory to detect speciesspecific vulnerabilities to EDCs in amphibians. KW - Endocrine disruption KW - 17α-ethinylestradiol (EE2) KW - Mass spectrometry KW - Sex reversal PY - 2016 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-357797 DO - https://doi.org/10.1038/srep23825 SN - 2045-2322 VL - 6 SP - Article No. 23825, 1 EP - 8 PB - Nature publishing group AN - OPUS4-35779 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Matkovic, A. A1 - Vasic, B. A1 - Pesic, J. A1 - Prinz, J. A1 - Bald, Ilko A1 - Milosavljevic, A. R. A1 - Gajic, R. T1 - Enhanced structural stability of DNA origami nanostructures by graphene encapsulation N2 - Wedemonstrate that a single-layer graphene replicates the shape ofDNAorigami nanostructures very well. It can be employed as a protective layer for the enhancement of structural stability of DNA origami nanostructures. Using the AFM based manipulation, we show that the normal force required to damage graphene encapsulated DNA origami nanostructures is over an order of magnitude greater than for the unprotected ones. In addition, we show that graphene encapsulation offers protection to the DNA origami nanostructures against prolonged exposure to deionized water, and multiple immersions. Through these results we demonstrate that graphene encapsulated DNA origami nanostructures are strong enough to sustain various solution phase processing, lithography and transfer steps, thus extending the limits of DNA-mediated bottom-up fabrication. KW - atomic force microscopy KW - graphene KW - DNA origami nanostructures PY - 2016 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-358741 UR - http://iopscience.iop.org/article/10.1088/1367-2630/18/2/025016 DO - https://doi.org/10.1088/1367-2630/18/2/025016 SN - 1367-2630 VL - 18 SP - 025016 PB - IOP PUBLISHING LTD CY - Bristol, UK AN - OPUS4-35874 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Prinz, J. A1 - Heck, Christian A1 - Ellerik, L. A1 - Merk, V. A1 - Bald, Ilko T1 - DNA origami based Au–Ag-core–shell nanoparticle dimers with single-molecule SERS sensitivity N2 - DNA origami nanostructures are a versatile tool to arrange metal nanostructures and other chemical entities with nanometer precision. In this way gold nanoparticle dimers with defined distance can be constructed, which can be exploited as novel substrates for surface enhanced Raman scattering (SERS). We have optimized the size, composition and arrangement of Au/Ag nanoparticles to create intense SERS hot spots, with Raman enhancement up to 10^10, which is sufficient to detect single molecules by Raman scattering. This is demonstrated using single dye molecules (TAMRA and Cy3) placed into the center of the nanoparticle dimers. In conjunction with the DNA origami nanostructures novel SERS substrates are created, which can in the future be applied to the SERS analysis of more complex biomolecular targets, whose position and conformation within the SERS hot spot can be precisely controlled. KW - single molecule spectroscopy KW - DNA origami KW - SERS KW - gold nanoparticles KW - silver nanoparticles PY - 2016 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-358761 UR - http://pubs.rsc.org/en/content/articlelanding/2016/nr/c5nr08674d#!divAbstract DO - https://doi.org/10.1039/C5NR08674D SP - 5612 EP - 5620 PB - Royal Society of Chemistry CY - Cambridge, England AN - OPUS4-35876 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Schoknecht, Ute A1 - Mathies, Helena A1 - Wegner, R. T1 - Biocide leaching during field experiments on treated articles N2 - Background: Biocidal products can be sources of active substances in surface waters caused by weathering of treated articles. Marketing and use of biocidal products can be limited according to the European Biocidal Products Regulation if unacceptable risks to the environment are expected. Leaching of active substances from treated articles was observed in field experiments to obtain information on leaching processes and investigate the suitability of a proposed test method. Results: Leaching under weathering conditions proceeds discontinuously and tends to decrease with duration of exposure. It mainly depends on the availability of water, but is also controlled by transport processes within the materials and stability of the observed substances. Runoff amount proved to be a suitable basis to compare results from different experiments. Concentrations of substances are higher in runoff collected from vertical surfaces compared to horizontal ones, whereas the leached amounts per surface area are higher from horizontal surfaces. Gaps in mass balances indicate that additional processes such as degradation and evaporation may be relevant to the fate of active substances in treated articles. Leached amounts of substances were considerably higher when the materials were exposed to intermittent water contact under laboratory conditions as compared to weathering of vertically exposed surfaces. Conclusions: Experiences from the field experiments were used to define parameters of a procedure that is now provided to fulfil requirements of the Biocidal Products Regulation. The experiments confirmed that the amount of water which is in contact with exposed surfaces is the crucial parameter determining leaching of substances. KW - Biozidprodukte KW - Farben KW - Textil KW - Auswaschung KW - Freilandtest KW - Biocidal products KW - Paints KW - Textile KW - Leaching KW - Field test PY - 2016 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-354090 DO - https://doi.org/10.1186/s12302-016-0074-9 VL - 28 IS - 6 SP - 1 EP - 10 PB - Springer CY - SpringerOpen AN - OPUS4-35409 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Sproesser, G. A1 - Schenker, S. A1 - Pittner, Andreas A1 - Borndörfer, R. A1 - Rethmeier, Michael A1 - Chang, Y.-J. A1 - Finkbeiner, M. T1 - Sustainable welding process selection based on weight space partitions N2 - Selecting a welding process for a given application is crucial with respect to the sustainability of part manufacturing. Unfortunately, since welding processes are evaluated by a number of criteria, preferences for one or the other process can be contradictory. However, the prevalent procedure of weight assignment for each criterion is subjective and does not provide information about the entire solution space. From the perspective of a decision maker it is important to be able to assess the entire set of possible weightings and answer the question which welding process is optimal for which set of weights. This issue is investigated by means of a weight space partitioning approach. Two welding processes are considered with respect to three criteria that reflect their economic and environmental performance. In order to find the most sustainable welding process the underlying weight space partition is evaluated. T2 - 13th Global Conference on Sustainable Manufacturing – Decoupling Growth from Resource Use CY - Bình Dương New City, Vietnam DA - 16.09.2015 KW - Welding costs KW - Multi-criteria decision support KW - LCA KW - Welding process selection KW - GMAW KW - Multi-attribute decision method PY - 2016 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-353740 DO - https://doi.org/10.1016/j.procir.2016.01.077 SN - 2212-8271 VL - 40 SP - 127 EP - 132 PB - Elsevier B.V. AN - OPUS4-35374 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Doriti, A. A1 - Brosnan, S. A1 - Weidner, Steffen A1 - Schlaad, H. T1 - Synthesis of polysarcosine from air and moisture stable N-phenoxycarbonyl-N-methylglycine assisted by tertiary amine base N2 - Polysarcosine (M-n = 3650-20 000 g mol(-1), D similar to 1.1) was synthesized from the air and moisture stable N-phenoxycarbonyl-N-methylglycine. Polymerization was achieved by in situ transformation of the urethane precursor into the corresponding N-methylglycine-N-carboxyanhydride, when in the presence of a non-nucleophilic tertiary amine base and a primary amine initiator. KW - Polysarcosine KW - MALDI-TOF MS KW - Synthesis PY - 2016 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-359309 DO - https://doi.org/10.1039/c6py00221h SN - 1759-9954 SN - 1759-9962 VL - 7 IS - 18 SP - 3067 EP - 3070 AN - OPUS4-35930 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Mangelsdorf, Axel A1 - Blind, K. T1 - Motives to standardize: Empirical evidence from Germany N2 - In this paper, we identify the strategic motives of German manufacturing companies in the electrical engineering and machinery industry to be involved in standards development organizations. First, we present the general motives for the formation of strategic alliances and relate them to specific standardization motives. Then, we identify pursuing specific company interests, solving technical problems, knowledge seeking, influencing regulation, and facilitating market access as motives to standardize by means of factor analysis. In a second step, we test hypotheses on the relationship between the importance of strategic motives and firm level variables, e.g. R&D intensity, innovation activities, and firm size. The results reveal that firms in electric engineering and machinery have a particularly strong interest in ensuring industry-friendly design of regulations, which can be achieved by standards. Moreover, the results confirm that small firms also from these two sectors are active in standardization alliances to access knowledge from other involved stakeholders. KW - Factor analysis KW - Standardization KW - Strategic alliances KW - Knowledge spillovers KW - Market access KW - Regulation KW - Innovation KW - R&D PY - 2016 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-364586 DO - https://doi.org/10.1016/j.technovation.2016.01.001 SN - 0166-4972 VL - 48-49 SP - 13 EP - 24 PB - Elsevier Science B.V. CY - Amsterdam, Netherlands AN - OPUS4-36458 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Cabeza, Sandra A1 - Bruno, Giovanni A1 - Mishurova, Tatiana T1 - Characterization of multiphase metal matrix composites by means of CT and neutron diffraction N2 - The present study examines the relationship between the microstructure of multiphase metal matrix composites and their damage mechanisms. The matrix AlSi12CuMgNi was combined with 15% vol. Al₂O₃ (short fibers), and with 7% vol. Al₂O₃ + 15% vol. SiC (short fibers and whiskers, respectively). The experimental approach encompasses 3D microstructure characterization by means of computed tomography of samples (a) as-cast, (b) after heat treatment, and (c) after compression tests at room temperature. The volume fraction of different phases, their distribution, their orientation, and the presence of defects and damage are studied. The influence of the addition of SiC particles on mechanical properties of composite was investigated. Phase-specific load partition analysis for samples with fiber plane parallel to load was performed by using neutron diffraction (ND) during in-situ compression. ND results show damage in the Si phase, while Al₂O₃ short fibers carry load without damage until failure. The computed tomography observations confirm the load partition analysis. T2 - WCNDT CY - München, Germany DA - 13.06.2016 KW - thermal treatment KW - synchrotron CT KW - neutron diffraction KW - composite KW - aluminum KW - residual stress PY - 2016 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-365499 AN - OPUS4-36549 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Naka, A. A1 - Yasutaka, T. A1 - Sakanakura, H. A1 - Kalbe, Ute A1 - Watanabe, Y. A1 - Inoba, S. A1 - Takeo, M. A1 - Inui, T. A1 - Katsumi, T. A1 - Fujikawa, T. A1 - Sato, K. A1 - Higashinog, K. A1 - Someyaga, M. T1 - Column percolation test for contaminated soils: Key factors for standardization N2 - Column percolation tests may be suitable for prediction of chemical leaching from soil and soil materials. However, compared with batch leaching tests, they are time-consuming. It is therefore important to investigate ways to shorten the tests without affecting the quality of results. In this study, we evaluate the feasibility of decreasing testing time by increasing flow rate and decreasing equilibration time compared to the conditions specified in ISO/TS 21268-3, with equilibration periods of 48 h and flow rate of 12 mL/h. We tested three equilibration periods (0, 12–16, and 48 h) and two flow rates (12 and 36 mL/h)on four different soils and compared the inorganic constituent releases. For soils A and D, we observed similar values for all conditions except for the 0 h–36 mL/h case. For soil B, we observed no appreciable differences between the tested conditions, while for soil C there were no consistent trends probably due to the difference in ongoing oxidation reactions between soil samples. These results suggest that column percolation tests can be shortened from 20 to 30 days to 7–9 days by decreasing the equilibration time to 12–16 h and increasing the flow rate to 36 mL/h for inorganic substances. KW - Contaminated soils KW - Column percolation PY - 2016 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-372038 DO - https://doi.org/10.1016/j.jhazmat.2016.08.046 SN - 0304-3894 VL - 320 SP - 326 EP - 340 PB - Elsevier B.V. AN - OPUS4-37203 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Büchner, T. A1 - Drescher, D. A1 - Merk, V. A1 - Traub, Heike A1 - Guttmann, P. A1 - Werner, St. A1 - Jakubowski, Norbert A1 - Schneider, G. A1 - Kneipp, J. T1 - Biomolecular environment, quantification, and intracellular interaction of multifunctional magnetic SERS nanoprobes N2 - Multifunctional composite nanoprobes consisting of iron oxide nanoparticles linked to silver and gold nanoparticles, Ag–Magnetite and Au–Magnetite, respectively, were introduced by endocytic uptake into cultured fibroblast cells. The cells containing the non-toxic nanoprobes were shown to be displaceable in an external magnetic field and can be manipulated in microfluidic channels. The distribution of the composite nanostructures that are contained in the endosomal system is discussed on the basis of surfaceenhanced Raman scattering (SERS) mapping, quantitative laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) micromapping, and cryo soft X-ray tomography (cryo soft-XRT). Cryo soft-XRT of intact, vitrified cells reveals that the composite nanoprobes form intra-endosomal aggregates. The nanoprobes provide SERS signals from the biomolecular composition of their surface in the endosomal environment. The SERS data indicate the high stability of the nanoprobes and of their plasmonic properties in the harsh environment of endosomes and lysosomes. The spectra point at the molecular composition at the surface of the Ag–Magnetite and Au–Magnetite nanostructures that is very similar to that of other Composite structures, but different from the composition of pure silver and gold SERS nanoprobes used for intracellular investigations. As shown by the LA-ICP-MS data, the uptake efficiency of the magnetite composites is approximately two to three times higher than that of the pure gold and silver nanoparticles. KW - Nanoparticles KW - SERS KW - Cell KW - LA-ICP-MS KW - X-ray tomography PY - 2016 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-371811 DO - https://doi.org/10.1039/c6an00890a SN - 0003-2654 VL - 141 IS - 17 SP - 5096 EP - 5106 PB - Royal Society of Chemistry CY - Cambridge, UK AN - OPUS4-37181 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Hsiao, I.-L. A1 - Bierkandt, Frank A1 - Reichardt, Ph. A1 - Luch, A. A1 - Huang, Y.-J. A1 - Jakubowski, Norbert A1 - Tentschert, J. A1 - Haase, A. T1 - Quantification and visualization of cellular uptake of TiO2 and Ag nanoparticles: comparison of different ICP-MS techniques N2 - Safety assessment of nanoparticles (NPs) requires techniques that are suitable to quantify tissue and cellular uptake of NPs. The most commonly applied techniques for this purpose are based on inductively coupled plasma mass spectrometry (ICP-MS). Here we apply and compare three different ICP-MS methods to investigate the cellular uptake of TiO2 (diameter 7 or 20 nm, respectively) and Ag (diameter 50 or 75 nm, respectively) NPs into differentiated mouse neuroblastoma cells (Neuro-2a cells). Cells were incubated with different amounts of the NPs. Thereafter they were either directly analyzed by laser ablation ICP-MS (LA-ICP-MS) or were lysed and lysates were analyzed by ICP-MS and by single particle ICP-MS (SP-ICP-MS). KW - Nanoparticles KW - Single particle ICP-MS KW - Laser ablation ICP-MS KW - Cellular internalization KW - Neurons PY - 2016 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-371620 DO - https://doi.org/10.1186/s12951-016-0203-z SN - 1477-3155 VL - 14 SP - Article 50 AN - OPUS4-37162 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kulla, Hannes A1 - Greiser, Sebastian A1 - Benemann, Sigrid A1 - Rademann, K. A1 - Emmerling, Franziska T1 - In Situ Investigation of a Self-Accelerated Cocrystal Formation by Grinding Pyrazinamide with Oxalic Acid N2 - A new cocrystal of pyrazinamide with oxalic acid was prepared mechanochemically and characterized by PXRD, Raman spectroscopy, solid-state NMR spectroscopy, DTA-TG, and SEM. Based on powder X-ray diffraction data the structure was solved. The formation pathway of the reaction was studied in situ using combined synchrotron PXRD and Raman spectroscopy. Using oxalic acid dihydrate the initially neat grinding turned into a rapid self-accelerated liquid-assisted grinding process by the release of crystallization water. Under these conditions, the cocrystal was formed directly within two minutes. KW - in situ KW - cocrystal KW - mechanochemistry KW - pyrazinamide KW - hydrate PY - 2016 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-372357 DO - https://doi.org/10.3390/molecules21070917 SN - 1420-3049 VL - 21 IS - 7 SP - Article 917, 1 EP - 9 AN - OPUS4-37235 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Schlick-Hasper, Eva A1 - Seidler, Oliver A1 - Goedecke, Thomas A1 - Kraume, M. T1 - Helium leak testing of dangerous goods packagings N2 - The International Dangerous Goods Regulations prescribe the immersion under water method (“bubble test”) as standard method for the leakproofness test of dangerous goods packagings. But this test procedure acts as a test method for leak localisation, not for quantitative leakage rates measurement. Additionally, the sensitivity in detecting leaks of small diameters is restricted, depending on the test liquid and the test pressure. The bubble test is not suitable for a comparison with quantitative limit leakage rates based on realistic transport conditions. This is especially important when estimating the risk of the formation of an explosive atmosphere during the intercontinental carriage of dangerous goods packagings in freight containers. To compare measured leakage rates with limit leakage rates, a quantitative leak testing procedure is required. Therefore a new approach for dangerous goods packagings is implemented: The pressure technique by accumulation using Helium as a tracer gas. This work presents the test equipment necessary for the quantitative measurement of Helium leakage rates through closures of different kinds of dangerous goods packagings. The essential steps to achieve good repeatable results are: A controlled Helium filling process to reach a defined test pressure in the test sample, a sufficient homogenisation of the Helium-air-mixture inside the test sample and the ensuring of a constant pressure level of the test sample during the test. The Helium loss rate of the accumulation chamber has to be measured separately to receive a correction factor for the measured leakage rates. Different constructional measures are introduced to prevent a disturbing influence of the Helium leakage rate of the filling valves on the measurement results. Methods to estimate the disturbing effect of Helium permeation through permeable parts of the test sample are also presented. As a supporting method for the experimental investigations the Helium sniffer test can be applied. This practical application-oriented advice can enable other users to establish a pressure technique by accumulation for their own technical field. T2 - 19th World Conference on Non-Destructive Testing CY - Munich, Germany DA - 13.06.2016 KW - Überdruckverfahren KW - Gefahrgutverpackungen KW - Dichtheit KW - Helium KW - Dangerous goods packagings KW - Leakproofness KW - Helium KW - Pressure technique PY - 2016 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-371376 UR - http://ndt.net/?id=19785 SN - 1435-4934 VL - 21 IS - 7 SP - 1 EP - 10 PB - NDT.net CY - Kirchwald AN - OPUS4-37137 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kotschate, Daniel A1 - Gohlke, Dirk A1 - Eisentraut, Mark T1 - Reference block design for high resolution ultrasound immersion tank N2 - In respect of modern approaches in material sciences and highly increased requirements on materials on safety relevant components, quality management and non-destructive testing reclaims a steadily increased meaning. The destructive meaning of measuring the degree of purity is defined in DIN EN 10247 through metallurgical investigations, especially microsections. For and comparable, but non-destructive testing due ultrasonic testing, the material the SEP 1927 is a well-defined industry standard. A novel and alternative way of reference block construction was focused by this work. The proposed amendments, regarding the manufacturing and machining, are less time and cost consuming. Verified by measurements the presented reference block fits the same acoustical characteristics and the requirements of the guideline. T2 - 19th World Conference on Non-Destructive Testing CY - Munich, Germany DA - 13.06.2016 KW - SEP 1927 KW - Degree of purity KW - High resolution ultrasonic testing KW - Immersion tank testing PY - 2016 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-368512 VL - 2016 SP - Paper X15, 1 EP - 4 AN - OPUS4-36851 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Wollschläger, Nicole A1 - Tasdemir, Z. A1 - Häusler, Ines A1 - Leblebici, Y. A1 - Österle, Werner A1 - Alaca, B. E. T1 - Determination of the elastic behavior of silicon nanowires within a scanning electron microscope N2 - Three-point bending tests were performed on double-anchored, <110> silicon nanowire samples inside a scanning electron microscope (SEM) via a micromanipulator equipped with a piezo-resistive force sensor. Representing the upper and lower boundaries achievable in a consistent manner, silicon nanowires with widths of 35 nm and 74 nm and a height of 168 nm were fabricated. The nanowires were obtained monolithically along with their 10-m-tall supports through a top-down fabrication approach involving a series of etching processes. Hence, no interface compliance was introduced between supports and nanowires. Exact nanowire dimensions and cross-sectional features were determined by transmission electron microscopy (TEM) following sample preparation through focused ion beam (FIB) machining. Conducting the experiments inside an SEM chamber further raised the opportunity of the direct observation of any deviation from ideal loading conditions such as twisting, which was taken into consideration in simulations. Measured force-displacement behavior was observed to exhibit close resemblance to simulation results obtained by finite element modeling, when the bulk value of 169 GPa was taken as the modulus of elasticity for <110> silicon. Hence, test results show neither any size effect nor evidence of residual stresses for the considered nanoscale objects. The increased effect of the native oxide with reduced nanowire dimensions was captured as well. Thus this very simple in-situ testing method was found to be an alternative to elaborate AFM measurements on geometrically formidable nanostructures. The results demonstrate the applicability of the developed fabrication approach to the incorporation of silicon nanowires in functional micromechanical devices. KW - Silicon nanowire KW - Elastic behavior KW - Scanning electron microscope KW - Mechanical properties PY - 2016 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-370383 DO - https://doi.org/10.1155/2016/4905838 VL - 2016 SP - Article 4905838, 1 EP - 6 PB - Hindawi Publishing Corporation AN - OPUS4-37038 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Schneider, Ralf A1 - Weigert, Florian A1 - Lesnyak, V. A1 - Leubner, S. A1 - Lorenz, T. A1 - Behnke, Thomas A1 - Dubavik, A. A1 - Joswig, J.-O. A1 - Resch-Genger, Ute A1 - Gaponik, N. A1 - Eychmüller, A. ED - Resch-Genger, Ute ED - Schneider, Ralf T1 - pH and concentration dependence of the optical properties of thiol-capped CdTe nanocrystals in water and D2O N2 - The optical properties of semiconductor nanocrystals (SC NCs) are largely controlled by their size and surface chemistry, i.e., the chemical composition and thickness of inorganic passivation shells and the chemical nature and number of surface ligands as well as the strength of their bonds to surface atoms. The latter is particularly important for CdTe NCs, which – together with alloyed CdₓHg₁₋ₓTe – are the only SC NCs that can be prepared in water in high quality without the need for an additional inorganic passivation shell. Aiming at a better understanding of the role of stabilizing ligands for the control of the application-relevant fluorescence features of SC NCs, we assessed the influence of two of the most commonly used monodentate thiol ligands, thioglycolic acid (TGA) and mercaptopropionic acid (MPA), on the colloidal stability, photoluminescence (PL) quantum yield (QY), and PL decay behavior of a set of CdTe NC colloids. As an indirect measure for the strength of the coordinative bond of the ligands to SC NC surface atoms, the influence of the pH (pD) and the concentration on the PL properties of these colloids was examined in water and D₂O and compared to the results from previous dilution studies with a set of thiol-capped Cd₁₋ₓHgₓTe SC NCs in D₂O. As a prerequisite for these studies, the number of surface ligands was determined photometrically at different steps of purification after SC NC synthesis with Ellman’s test. Our results demonstrate ligand control of the pH-dependent PL of these SC NCs, with MPA-stabilized CdTe NCs being less prone to luminescence quenching than TGA-capped ones. For both types of CdTe colloids, ligand desorption is more pronounced in H₂O compared to D₂O, underlining also the role of hydrogen bonding and solvent molecules. KW - Quantum dots KW - Fluorescence KW - Ligand analysis KW - Nano particles PY - 2016 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-371253 DO - https://doi.org/10.1039/c6cp03123d VL - 18 IS - 28 SP - 19083 EP - 19092 PB - RSC CY - Cambridge AN - OPUS4-37125 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Scherb, Tobias A1 - Kimber, S. A. J. A1 - Stephan, Christiane A1 - Henry, P. F. A1 - Schumacher, G. A1 - Escolástico, S. A1 - Serra, J. M. A1 - Seeger, J. A1 - Just, J. A1 - Hill, A.H. A1 - Banhart, J. T1 - Nanoscale order in the frustrated mixed conductor La5.6WO12-Delta N2 - This article reports a comprehensive investigation of the average and local structure of La5.6WO12-δ, which has excellent mixed proton, electron and oxide ion conduction suitable for device applications. Synchrotron X-ray and neutron powder diffraction show that a cubic fluorite supercell describes the average structure, with highly disordered lanthanum and oxide positions. On average, the tungsten sites are sixfold coordinated and a trace [3.7 (1.3)%] of anti-site disorder is detected. In addition to sharp Bragg reflections, strong diffuse neutron scattering is observed, which hints at short-range order. Plausible local configurations are considered and it is shown that the defect chemistry implies a simple 'chemical exchange' interaction that favours ordered WO6 octahedra. The local model is confirmed by synchrotron X-ray pair distribution function analysis and EXAFS experiments performed at the La K and W L-3 edges. It is shown that ordered domains of similar to 3.5 nm are found, implying that mixed conduction in La5.6WO12-δ is associated with a defective glassy-like anion sublattice. The origins of this ground state are proposed to lie in the nonbipartite nature of the face-centred cubic lattice and the pairwise interactions which link the orientation of neighbouring octahedral WO6 sites. This 'function through frustration' could provide a means of designing new mixed conductors. KW - neutron diffraction KW - x-ray diffraction KW - proton conductors PY - 2016 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-366756 DO - https://doi.org/10.1107/S1600576716006415 SN - 1600-5767 VL - 49 IS - Issue 3 SP - 997 EP - 1008 PB - International Union of Crystallography CY - Chester, UK AN - OPUS4-36675 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Meiling, T. A1 - Cywinski, P. A1 - Bald, Ilko T1 - White carbon: Fluorescent carbon nanoparticles with tunable quantum yield in a reproducible green synthesis N2 - In this study, a new reliable, economic, and environmentally-friendly one-step synthesis is established to obtain carbon nanodots (CNDs) with well-defined and reproducible photoluminescence (PL) properties via the microwave-assisted hydrothermal treatment of starch and Tris-acetate-EDTA (TAE) buffer as carbon sources. Three kinds of CNDs are prepared using different sets of above mentioned starting materials. The as-synthesized CNDs: C-CND (starch only), N-CND 1 (starch in TAE) and N-CND 2 (TAE only) exhibit highly homogenous PL and are ready to use without need for further purification. The CNDs are stable over a long period of time (>1 year) either in solution or as freeze-dried powder. Depending on starting material, CNDs with PL quantum yield (PLQY) ranging from less than 1% up to 28% are obtained. The influence of the precursor concentration, reaction time and type of additives on the optical properties (UV-Vis absorption, PL emission spectrum and PLQY) is carefully investigated, providing insight into the chemical processes that occur during CND formation. Remarkably, upon freeze-drying the initially brown CND-solution turns into a non-fluorescent white/slightly Brown powder which recovers PL in aqueous solution and can potentially be applied as fluorescent marker in bio-imaging, as a reduction agent or as a photocatalyst. KW - Carbon dots KW - Quantum yield KW - Fluorescence KW - Nanoparticles PY - 2016 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-367204 DO - https://doi.org/10.1038/srep28557 VL - 6 SP - Article 28557, 1 EP - 9 PB - Nature Publishing Group AN - OPUS4-36720 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Neubert, Sebastian A1 - Pittner, Andreas A1 - Rethmeier, Michael T1 - Experimental determination of TRIP parameter K for mild- and high strength low alloy steels and a super martensitic filler material N2 - A combined experimental numerical approach is applied to determine the transformation induced plasticity (TRIP)-parameter K for different strength low-alloy steels of grade S355J2+N and S960QL as well as the super martensitic filler CN13-4-IG containing 13 wt% chromium and 4 wt% nickel. The thermo-physical analyses were conducted using a Gleeble® 3500 facility. The thermal histories of the specimens to be tested were extracted from corresponding simulations of a real gas metal arc weldment. In contrast to common TRIP-experiments which are based on complex specimens a simple flat specimen was utilized together with an engineering evaluation method. The evaluation method was validated with literature values for the TRIP-parameter. It could be shown that the proposed approach enables a correct description of the TRIP behavior. KW - Transformation induced plasticity (TRIP) KW - Phase transformation KW - High-strength low-alloy steel KW - Super martensitic filler material KW - Thermo physical simulation KW - Gleeble experiments PY - 2016 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-367297 DO - https://doi.org/10.1186/s40064-016-2474-0 VL - 5 IS - 575 SP - Paper 754, 1 EP - 16 PB - SpringerPlus AN - OPUS4-36729 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Rosemann, Paul A1 - Müller, Christina A1 - Meyer, A. A1 - Halle, T. T1 - Influence of nitrogen on the corrosion resistance of martensitic stainless steels N2 - The corrosion resistance of martensitic stainless steels (MSS) depends strongly on the chemical composition and the applied heat treatment. Both determines the distribution of the alloying elements in the microstructure and the resulting material properties. The addition of nitrogen is known to be beneficial for the pitting corrosion resistance of stainless steels. In case of MSS this effect is not only connected to nitrogen itself because nitrogen can be used to substitute carbon which also influences the result of the heat treatment process. This paper shows the effect of nitrogen on the corrosion resistance in relation to the hardening process of MSS. Therefore the effects of austenitization duration, austenitization temperature and cooling rate on microstructure, hardness and corrosion resistance were studied on the MSS X30CrMoN15 1 and X50CrMoV15. The effect of different cooling rates was studied in the range of > 100 K/s down to 1 K/s using the jominy end quench test. The changes in corrosion resistance were detected with electrochemical potentiodynamic reactivation (EPR) and by the determination of critical pitting potentials. Besides this experimental approach thermodynamic calculations with the software thermocalc will be presented and used for the interpretation of the effect of nitrogen on the corrosion resistance of MSS. T2 - 18th Chemnitz Seminar on Materials Engineering – 18. Werkstofftechnisches Kolloquium CY - Chemnitz, Germany KW - Martensitic stainless steels KW - Corrosion resistance KW - Heat treatment PY - 2016 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-366956 DO - https://doi.org/10.1088/1757-899X/118/1/011002 VL - 118 IS - 1 SP - 19 EP - 19 PB - IOP Publishing AN - OPUS4-36695 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Pavlovic, Mato A1 - Müller, Christina A1 - Ronneteg, U. T1 - Reliability Analysis of the Phased-Array Ultrasonic System used for the Inspection of Friction Stir Welds N2 - The canister for the permanent storage of spent nuclear fuel used by SKB in Sweden consists of a cast iron insert surrounded by a five centimetre thick shell of copper. It is a safety critical component and in order to secure long-term structural integrity non-destructive methods are used to inspect 100% of the volume of each canister, before it is disposed of in the repository. One of the critical components that requires inspection is a sealing weld, joining the copper tube and the lid. The friction stir weld is inspected using an ultrasonic phased array system. The area of the weld is inspected with several inspection channels with different angles and varying coverage. To make sure that no defects that might occur in the weld are overseen, the reliability of the inspection must be quantified. The reliability of NDT is usually quantified with the probability of detection curves. The influence of the parameters that might influence the POD of the flaws in the weld is investigated analysing the experimental results, as well as with a help of a numerical simulation of the inspection. T2 - 19th Wolrd Conference on Nondestructive Testing CY - Munich, Germany DA - 13.06.2016 KW - NDT KW - Ultrasonic KW - Reliability KW - POD KW - Copper KW - FSW KW - JLH PY - 2016 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-366982 VL - 2016/158 SP - We.4.E.5 PB - Deutsche Gesellschaft für zerstörungsfreie Prüfung (DGZfP) CY - Berlin AN - OPUS4-36698 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Pavlovic, Mato A1 - Müller, Christina A1 - Heckel, Thomas A1 - Zoёga, Andreas T1 - Reliability analysis of the ultrasonic inspection system for the inspection of hollow railway axles N2 - Axles are safety critical train components that are subjected to significant cyclic loading during operation. If the crack is initiated in the axle, cyclic loading will lead to crack propagation. To maintain structural integrity, axles must be periodically inspected for fatigue cracks in the material. Deutsche Bahn uses mechanized ultrasonic inspection system to inspect hollow railway axles. The inspections are performed from the bore surface, using several conventional transducers with different incident angles, inspecting the axle along the entire length. As with the every safety critical system, the reliability of these inspections must be determined with regard to their flaw detection capabilities. Traditionally this is done according to the relevant standards for railway vehicles. To investigate the capability of the NDT system more thoroughly, we want to evaluate the capability of the inspection system to detect flaws by means of probability of detection (POD) curves. It will be shown that other parameters, beside the size of the crack, for example crack position in the axle, influence the detection of the crack. The influence of these parameters was evaluated using ultrasonic simulation. The evaluation served as an input for the manufacturing of the flaws in the real scale axle. Once these axles are inspected and the data evaluated, using data from both measurement and simulation, we will express the POD of the crack as function of influencing parameters using the multiparameter POD model. T2 - 19th Wolrd Conference on Nondestructive Testing CY - Munich, Germany DA - 13.06.2016 KW - POD KW - Railway KW - Axle KW - Safety KW - Reliability KW - Ultrasonics PY - 2016 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-366996 VL - 2016/158 SP - Tu.3.D.5 PB - Deutsche Gesellschaft für zerstörungsfreie Prüfung (DGZfP) CY - Berlin AN - OPUS4-36699 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Gaal, Mate A1 - Daschewski, Maxim A1 - Bartusch, Jürgen A1 - Schadow, Florian A1 - Dohse, Elmar A1 - Kreutzbruck, Marc A1 - Weise, Matthias A1 - Beck, Uwe T1 - Novel air-coupled ultrasonic transducer combining the thermoacoustic with the piezoelectric effect N2 - In recent years, there has been an increasing industrial demand for one-sided inspection of various structures by means of air-coupled ultrasonic technique. Lightweight structures based on carbon-fibre-reinforced polymers may have very complex shapes, making air-coupled transmission difficult or even impossible. The inspection of concrete structures is another example where one-sided inspection is required. To address these challenges a new type of transducer for air-coupled pulse-echo inspection was developed, which unites two principles: thermoacoustic emission and piezoelectric reception. The thermoacoustic emitter is a titanium electrode with a thickness of several tens of nanometer. This electrode was deposited onto charged cellular polypropylene, which serves as a piezoelectric receiver. The thermoacoustic transmission is based on a transformation of the thermal energy of an electrically heated electrode into the acoustic energy of an ultrasonic wave. Thermoacoustic emitters provide resonance-free behaviour and thus extremely broadband pulses. Charged cellular polypropylene is piezoelectric due to the polarization of its cells and it is well matched to air, with a Young modulus in the order of magnitude of MPa. In this contribution we present some pulse-echo measurements with the first prototypes of the combined thermoacoustic-piezoelectric transducer. T2 - World Conference of Non-Destructive Testing CY - Munich, Germany DA - 13.6.2016 KW - Thermoacoustic KW - Piezoelectric KW - Ultrasonic transducer KW - Ferroelectret PY - 2016 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-367151 VL - 158 SP - Mo.1.F.4, 1 EP - 6 AN - OPUS4-36715 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Seiffert, Franz A1 - Bandow, Nicole A1 - Kalbe, Ute A1 - Milke, R. A1 - Gorbushina, Anna T1 - Laboratory tools to quantify biogenic dissolution of rocks and minerals: a model rock biofilm growing in percolation columns N2 - Sub-aerial biofilms (SAB) are ubiquitous, self-sufficient microbial ecosystems found on mineral surfaces at all altitudes and latitudes. SABs, which are the principal causes of weathering on exposed terrestrial surfaces, are characterized by patchy growth dominated by associations of algae, cyanobacteria, fungi and heterotrophic bacteria. A recently developed in vitro system to study colonization of rocks exposed to air included two key SAB participants - the rock-inhabiting ascomycete Knufia petricola (CBS 123872) and the phototrophic cyanobacterium Nostoc punctiforme ATCC29133. Both partners are genetically tractable and we used them here to study weathering of granite, K-feldspar and plagioclase. Small fragments of the various rocks or minerals (1–6 mm) were packed into flow-through columns and incubated with 0.1% glucose and 10 μM thiamine-hydrochloride (90 μL min−1) to compare weathering with and without biofilms. Dissolution of the minerals was followed by: (i) analysing the degradation products in the effluent from the columns via Inductively Coupled Plasma Spectroscopy and (ii) by studying polished sections of the incubated mineral fragments/grains using scanning electron microscopy, transmission electron microscopy and energy dispersive X-ray analyses. K. petricola/N. punctiforme stimulated release of Ca, Na, Mg and Mn. Analyses of the polished sections confirmed depletion of Ca, Na and K near the surface of the fragments. The abrupt decrease in Ca concentration observed in peripheral areas of plagioclase fragments favored a dissolution-reprecipitation mechanism. Percolation columns in combination with a model biofilm can thus be used to study weathering in closed systems. Columns can easily be filled with different minerals and biofilms, the effluent as well as grains can be collected after long-term exposure under axenic conditions and easily analyzed. KW - Biotic weathering KW - Flow-through columns KW - Plagioclase KW - K-feldspar KW - Granite PY - 2016 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-373395 DO - https://doi.org/10.3389/feart.2016.00031 SN - 2296-6463 VL - 4 SP - Article 31, 1 EP - 10 PB - Frontiers in Earth Science CY - Lausanne AN - OPUS4-37339 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Färber, C. A1 - Titschack, J. A1 - Schönberg, Chr. H. L. A1 - Ehrig, Karsten A1 - Boos, K. A1 - Illerhaus, Bernhard A1 - Asgaard, U. A1 - Bromley, R. G. A1 - Freiwald, A. A1 - Wisshak, M. ED - Bahn, M. ED - Fennel, K. ED - Kesselmeier, J. ED - Naqvi, S. W. A. T1 - Long-term macrobioerosion in the Mediterranean Sea assessed by micro-computed tomography N2 - Biological erosion is a key process for the recycling of carbonate and the formation of calcareous sediments in the oceans. Experimental studies showed that bioerosion is subject to distinct temporal variability, but previous long-term studies were restricted to tropical waters. Here, we present results from a 14-year bioerosion experiment that was carried out along the rocky limestone coast of the island of Rhodes, Greece, in the Eastern Mediterranean Sea, in order to monitor the pace at which bioerosion affects carbonate substrate and the sequence of colonisation by bioeroding organisms. Internal macrobioerosion was visualised and quantified by micro-computed tomography and computer-algorithm-based segmentation procedures. Analysis of internal macrobioerosion traces revealed a dominance of bioeroding sponges producing eight types of characteristic Entobia cavity networks, which were matched to five different clionaid sponges by spicule identification in extracted tissue. The morphology of the entobians strongly varied depending on the species of the producing sponge, its ontogenetic stage, available space, and competition by other bioeroders. An early community developed during the first 5 years of exposure with initially very low macrobioerosion rates and was followed by an intermediate stage when sponges formed large and more diverse entobians and bioerosion rates in-creased. After 14 years, 30 % of the block volumes were occupied by boring sponges, yielding maximum bioerosion rates of 900 g m. KW - Bioerosion KW - Computed tomography KW - Carbonate substrate PY - 2016 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-372709 UR - http://www.biogeosciences.net/13/3461/2016/bg-13-3461-2016.pdf DO - https://doi.org/10.5194/bg-13-3461-2016 VL - 13 IS - 11 SP - 3461 EP - 3474 PB - Copernicus Publications CY - Göttingen AN - OPUS4-37270 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schröder, Volkmar A1 - Askar, Enis A1 - Tashqin, T. T1 - Sicherheitstechnische Eigenschaften von Gemischen aus Wasserstoff und Erdgas N2 - Bei der Power-to-Gas-Technologie wird überschüssiger Strom aus erneuerbaren Ener-gien durch Elektrolyse von Wasser in Wasserstoff umgewandelt. Dieser Wasserstoff kann als „chemischer Energiespeicher“ dienen und rückverstromt werden oder aber in das Erdgasnetz eingespeist werden. Die BAM hat die Auswirkungen von Wasserstoffzu-sätzen zum Erdgas im Hinblick auf den Explosionsschutz untersucht und sicherheitstechnische Kenngrößen für Erdgas-Wasserstoff-Gemische bestimmt. Von besonderem Interesse waren dabei die Explosionsgrenzen, die Sauerstoffgrenzkonzentration, die maximalen Explosionsdrücke, die KG-Werte und die Normspaltweiten. Für die Messungen sind zwei Modellgase eingesetzt worden, reines Methan und ein Modell-Erdgas mit Anteilen höherer Kohlenwasserstoffe. Sie repräsentieren die Bandbreite der in Deutschland eingesetzten Erdgase. Die Untersuchungen ergaben, dass bei einem Zusatz von bis zu 10 Mol-% Wasserstoff keine der untersuchten Kenngrößen signifikant beeinflusst wird. Die Gemische haben nur geringfügig erweiterte Explosionsbereiche und bleiben, wie die reinen Erdgase, in der Explosionsgruppe IIA. Auch die maximalen Explosionsdrücke und die zeitlichen Druckanstiege bei den Gasexplosionen werden nur wenig beeinflusst. T2 - Kolloquium zur chemischen und physikalischen Sicherheitstechnik CY - Berlin, Germany DA - 14.06.2016 KW - Wasserstoff KW - Erdgasnetz KW - Energiespeicherung KW - Explosionsschutz KW - Sicherheitstechnische Kenngrößen PY - 2016 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-373099 SN - 978-3-9817853-5-7 SN - 0938-5533 VL - 2016 SP - 60 EP - 67 PB - Bundesanstalt für Materialforschung und -prüfung (BAM) CY - Berlin, Germany AN - OPUS4-37309 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -