TY - CONF A1 - Schaupp, Thomas A1 - Burger, S. A1 - Kannengießer, Thomas A1 - Zinke, M. A1 - Jüttner, S. T1 - Berichterstattung zum laufenden Projekt: „Ermittlung geeigneter Wärmeführungen zur Wasserstoffreduktion beim Schweißen höherfester Feinkornbaustähle mit modifiziertem Sprühlichtbogen“ N2 - Dieses Dokument fasst den Projekfortschritt des BAM-Projektes "Ermittlung geeigneter Wärmeführungen zur Wasserstoffreduktion beim Schweißen höherfester Feinkornbaustähle mit modifiziertem Sprühlichtbogen" im Rahmen des Fachausschusses 1 "Schweißmetallurgie & Werkstoffverhalten" des DVS e. V. zusammen. T2 - Sitzung des Fachausschusses 01 "Schweißmetallurgie & Werkstoffverhalten" der Forschungsvereinigung Schweißen und verwandte Verfahren des DVS e. V. CY - Düsseldorf, Germany DA - 17.03.2016 KW - Hochfester Feinkornbaustahl KW - Wasserstoff KW - MAG-Schweißen PY - 2016 AN - OPUS4-53670 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schaupp, Thomas A1 - Burger, S. A1 - Kannengießer, Thomas A1 - Zinke, M. A1 - Jüttner, S. T1 - Berichterstattung zum laufenden Projekt: „Ermittlung geeigneter Wärmeführungen zur Wasserstoffreduktion beim Schweißen höherfester Feinkornbaustähle mit modifiziertem Sprühlichtbogen“ N2 - Dieses Dokument fasst den Projekfortschritt des BAM-Projektes "Ermittlung geeigneter Wärmeführungen zur Wasserstoffreduktion beim Schweißen höherfester Feinkornbaustähle mit modifiziertem Sprühlichtbogen" im Rahmen des Fachausschusses 1 "Schweißmetallurgie & Werkstoffverhalten" des DVS e. V. zusammen. T2 - Sitzung des Fachausschusses 01 "Schweißmetallurgie & Werkstoffverhalten" der Forschungsvereinigung Schweißen und verwandte Verfahren des DVS e. V. CY - Düsseldorf, Germany DA - 08.09.2016 KW - Hochfester Feinkornbaustahl KW - Wasserstoff KW - MAG-Schweißen PY - 2016 AN - OPUS4-53671 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - THES A1 - Bertovic, Marija T1 - Human Factors in Non-Destructive Testing (NDT): Risks and Challenges of Mechanised NDT T1 - Human Factors bei der zerstörungsfreien Prüfung (ZfP): Risiken und Herausforderungen mechanisierter ZfP N2 - Non-destructive testing (NDT) is regarded as one of the key elements in ensuring quality of engineering systems and their safe use. A failure of NDT to detect critical defects in safetyrelevant components, such as those in the nuclear industry, may lead to catastrophic consequences for the environment and the people. Therefore, ensuring that NDT methods are capable of detecting all critical defects, i.e. that they are reliable, is of utmost importance. Reliability of NDT is affected by human factors, which have thus far received the least amount of attention in the reliability assessments. With increased use of automation, in terms of mechanised testing (automation-assisted inspection and the corresponding evaluation of data), higher reliability standards are believed to have been achieved. However, human inspectors, and thus human factors, still play an important role throughout this process, and the risks involved in this application are unknown. The overall aim of the work presented in this dissertation was to explore for the first time the risks associated with mechanised NDT and find ways of mitigating their effects on the inspection performance. Hence, the objectives were to (1) identify and analyse potential risks in mechanised NDT, (2) devise measures against them, (3) critically address the preventive measures with respect to new potential risks, and (4) suggest ways for the implementation of the preventive measures. To address the first two objectives a risk assessment in form of a Failure Modes and Effects Analysis (FMEA) was conducted (Study 1). This analysis revealed potential for failure during both the acquisition and evaluation of NDT data that could be assigned to human, technology, and organisation. Since the existing preventive measures are insufficient to defend the system from identified failures, new preventive measures were suggested. The conclusion of the study was that those preventive measures need to be carefully considered with respect to new potential risks, before they can be implemented, thus serving as a starting point for further empirical studies. To address the final two objectives, two preventive measures, i.e. human redundancy and the use of automated aids in the evaluation of NDT data, were critically assessed with regard to potential downfalls arising from the social interaction between redundant individuals and the belief in the high reliability of automated aids. The second study was concerned with the potential withdrawal of effort in sequential redundant teams when working collectively as opposed to working alone, when independence between the two redundant individuals is not present. The results revealed that the first redundant inspector, led to believe someone else will conduct the same task afterwards, invested the same amount of effort as when working alone. The redundant checker was not affected by the information about the superior experience of his predecessor and—instead of expected withdrawal of effort—exhibited better performance in the task. Both results were in contradiction to the hypotheses, the explanations for which can be found in the social loafing and social compensation effects and in the methodological limitations. The third study examined inappropriate use of the aid measured in terms of (a) agreement with the errors of the aid in connection to the frequency of verifying its results and in terms of (b) the overall performance in the task. The results showed that the information about the high reliability of the aid did not affect the perception of that aid’s performance and, hence, no differences in the actual use of the aid were to be expected. However, the participants did not use the aid appropriately: They misused it, i.e. agreed with the errors committed by the aid and disused it, i.e. disagreed with the correct information provided by the aid, thereby reducing the overall reliability of the aid in terms of sizing ability. Whereas aid’s misuse could be assigned to low propensity to take risks and reduced verification behaviour because of a bias towards automation, the disuse was assigned to the possible misunderstanding of the task. The results of these studies raised the awareness that methods used to increase reliability and safety, such as automation and human redundancy, can backfire if their implementation is not carefully considered with respect to new potential risks arising from the interaction between individuals and complex systems. In an attempt to minimise this risk, suggestions for their implementation in the NDT practice were provided. N2 - Die zerstörungsfreie Prüfung (ZfP) wird als eines der wichtigsten Qualitätssicherungsmaßnahmen für technische Systeme und deren sichere Anwendung betrachtet. Wenn die ZfP kritische Defekte in sicherheitsrelevanten Anlagen, wie z.B. in der Kerntechnik, nicht entdeckt, kann dies zu katastrophalen Folgen für die Umwelt und den Menschen führen. Deshalb muss gewährleistet sein, dass die Verfahren der ZfP zuverlässig sind, d.h. dass sie alle kritischen Defekte entdecken können. Die Zuverlässigkeit der ZfP wird von menschlichen Faktoren beeinflusst, die jedoch bisher in diesem Feld selten betrachtet wurden. Durch den verstärkten Einsatz von Automatisierung beispielsweise bei der mechanisierten Prüfung (automatisierungsunterstütze Prüfung und die zugehörige Datenbewertung) wurde die Erreichung eines höheren Zuverlässigkeitsniveaus erwartet. Menschliche Faktoren sind trotz der Automatisierung immer noch bedeutsam für den gesamten Prüfprozess. Die Risiken der stärkeren Automatisierung der Prüfungen sind nicht vollständig bekannt. Das generelle Anliegen dieser Arbeit ist die erstmalige Feststellung der Risiken der mechanisierten ZfP und das Aufzeigen von Möglichkeiten, diese zu verringern. Die konkreten Ziele dieser Arbeit sind dementsprechend (1) die potenziellen Risiken bei der mechanisierten Prüfung aufzuzeigen und zu analysieren, (2) präventive Maßnahmen für diese Risiken abzuleiten, (3) diese präventiven Maßnahmen kritisch hinsichtlich neuer Risiken zu beleuchten sowie (4) Umsetzungsvorschläge aufzuzeigen. Für die ersten zwei Ziele wurde eine Risikoabschätzung mit der Fehlzustandsart- und auswirkungsanalyse (FMEA) durchgeführt (Studie 1). Diese Analyse ergab Fehlermöglichkeiten während der Datenaufnahme und –bewertung bei der mechanisierten ZfP, die dem Menschen, der Technik und der Organisation zugeordnet werden können. Weil die vorhandenen präventiven Maßnahmen unzureichend für die Vermeidung der identifizierten Fehler waren, wurden neue präventive Maßnahmen vorgeschlagen. Die Schlussfolgerung der Studie zeigt, dass vor der Umsetzung präventiver Maßnahmen eine sorgfältige Betrachtung hinsichtlich neuer potenzieller Risiken erfolgen muss. Dies war der Ausgangspunkt für die weiteren empirischen Untersuchungen. Für die letzten beiden Ziele wurden zwei präventive Maßnahmen untersucht: die menschliche Redundanz und die Anwendung automatisierter Assistenzsysteme bei der ZfP-Datenbewertung. Im Fokus lagen potenzielle Schwachstellen, die aus sozialer Interaktion der redundanten Individuen und aus dem Vertrauen in die hohe Zuverlässigkeit der automatisierten Assistenzsysteme entstehen können. In der zweiten Studie wurde die potenzielle Reduzierung der Anstrengung in sequentiellen redundanten Teams untersucht, indem die gemeinsame Aufgabenbearbeitung in Teams der individuellen Aufgabenbearbeitung gegenüber gestellt wurde. Die Ergebnisse zeigten, dass der erste redundante Prüfer, dem mitgeteilt wurde, dass ein anderer Prüfer die Prüfaufgabe nach ihm durchführen wird, die gleiche Anstrengung investierte wie der individuelle Bearbeiter. Der zweite redundante Prüfer (redundant checker) wurde durch die Information, dass sein Vorprüfer die höherwertige Erfahrung besitzt, nicht hypothesenkonform beeinflusst - anstelle der erwarteten Rücknahme der Anstrengung - zeigte er eine bessere Leistung bei der Durchführung der Aufgabe. Beide Ergebnisse stehen in Widerspruch zu den Hypothesen und können durch social loafing und social compensation Effekte sowie durch methodische Aspekte erklärt werden. In der dritten Studie wurde die unangemessene Nutzung eines automatisierten Assistenzsystems untersucht operationalisiert als (a) die Übereinstimmung mit Fehlern des Systems verbunden mit der Überprüfungshäufigkeit seiner Ergebnisse und (b) die Leistung bei der Aufgabe. Die Ergebnisse zeigten, dass die Information über die hohe Zuverlässigkeit des Systems die Wahrnehmung der Systemleistung nicht beeinflusste und folglich keine Unterschiede in der tatsächlichen Nutzung des Systems zu finden waren. Die Probanden nutzten jedoch das System nicht angemessen: sie stimmten den Fehlern des Systems zu (automation misuse) und sie lehnten korrekte Informationen des Systems ab (automation disuse). So reduzierten sie die Gesamtzuverlässigkeit des Systems, zumeist bei der Fehlergrößenbestimmung. Während misuse mit einer niedrigen Risikobereitschaft und eingeschränkten Überprüfungsverhalten auf Grund des automation bias erklärt werden kann, wird disuse dem möglichen Missverstehen der Aufgabe zugeordnet. Die Ergebnisse dieser Studien haben das Bewusstsein dafür erhöht, dass Methoden zur Erhöhung der Zuverlässigkeit und Sicherheit sowie Automatisierung und menschliche Redundanz versagen können, wenn die potenziellen Risiken ihrer Umsetzung aufgrund der Interaktion zwischen Mensch und Technik nicht bedacht werden. Um diese Risiken bei der Anwendung präventiver Maßnahmen zu minimieren, wurden Vorschläge für die ZfP-Praxis erarbeitet. T3 - BAM Dissertationsreihe - 145 KW - Failure modes and effects analysis KW - Zuverlässigkeit KW - Menschliche Faktoren KW - Zerstörungsfreie Prüfung KW - Fehlzustandsart- und auswirkungsanalyse KW - Personelle Redundanz KW - Human factors KW - Non-destructive testing KW - Human redundancy KW - Automation bias KW - Reliability PY - 2016 UR - https://nbn-resolving.org/urn:nbn:de:kobv:83-opus4-71292 SN - 978-3-9817502-7-0 DO - https://doi.org/10.14279/depositonce-4685 SN - 1613-4249 VL - 145 SP - 1 EP - 161 PB - Bundesanstalt für Materialforschung und -prüfung (BAM) CY - Berlin AN - OPUS4-36090 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hutchinson, R. A1 - Wilkins, J. A1 - Summerfield, L. A1 - O’Connor, C. A1 - McLachlin, K. A1 - Jakubowski, Norbert A1 - Traub, Heike A1 - Esteban-Fernández, Diego T1 - Performance and data from an elemental microscope - The NWR image N2 - The NWRimage system is the first elemental imaging-specific laser ablation instrument, offering breakthrough sub-micron spatial resolution and ultra-fast signal response for high throughput rates. Laser ablation (LA) systems are used in conjunction with Inductively Coupled Plasma Mass Spectrometry (ICP-MS) systems to detect and analyze tiny amounts of material. As ICP-MS systems have become more sensitive, a need has emerged for LA imaging tools with < 1 micron spatial resolution - a capability not previously available on the market. The NWRimage is provided with a carefully designed aerosol path from point of ablation to injection into the ICP itself. This aerosol path combined with a novel Dual Concentric Injector (DCI) ICP torch, yields < 50ms signal response to accelerate the speed of analysis and enabling enhanced sample throughput. The LA system is used for bio imaging of single cells and medical tissue samples. T2 - Winter Conference on Plasma Spectrochemistry 2016 CY - Tucson, Arizona, USA DA - 11.01.2016 KW - Laser ablation KW - Bio imaging PY - 2016 AN - OPUS4-36513 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Jaunich, Matthias A1 - Wolff, Dietmar T1 - Use of rubber seals at low temperatures N2 - Rubber is widely used as sealing material in various applications. In many fields the function of seal materials at low temperatures is necessary. Therefore, the understanding of failure mechanisms that lead to leakage at low temperatures is of high importance. It is known that the material properties of rubbers are strongly temperature dependent. At low temperatures this is caused by the rubber-glass transition (abbr. glass transition). During continuous cooling, due to the glass transition the material changes from rubber-like entropy-elastic behaviour to stiff energy-elastic behaviour, that allows nearly no strain or retraction. Hence, rubbers are normally used above their glass transition. But as the minimum working temperature limit of elastomers cannot be defined globally and precisely, the lower operation temperature limit of rubber seals should be determined in dependence of the application conditions and the most relevant material properties. In this paper, wesummarize results of our temperature dependent investigation of seal material properties by classical thermal analysis as Differential Scanning Calorimetry (DSC) and Dynamic Mechanical Analysis (DMA), combined with measurements of standardized tests as compression set and the seal performance determined in component tests. To reduce the test time of compression set tests a faster technique was developed and applied. To study the influence of dynamic events on the seal performance and to enhance the understanding of occurring seal failure, a setup for a fast partial seal release was designed. T2 - RubberCon 2016 CY - Tampere, Finland DA - 08.06.2016 KW - O-Ring KW - Compression set KW - Leakage rate KW - Low temperature PY - 2016 AN - OPUS4-36514 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Rhode, Michael A1 - Steppan, Enrico A1 - Kannengießer, Thomas A1 - Steger, Jörg ED - Lippold, J. T1 - Effect of hydrogen on mechanical properties of heat affected zone of a reactor pressure vessel steel grade N2 - The steel grade 20MnMoNi5-5 (according to German DIN standard or 16MND5 according to French AFNOR standard) is widely applied in (weld) fabrication of reactor pressure vessel components. Thus, a wide range of welding technologies (like submerged arc welding (SAW) or tungsten inert gas (TIG)) is used resulting in different heat affected zone (HAZ) microstructures. During weld fabrication, the weld joints may take up hydrogen. Especially, the HAZ shows an increased susceptibility for a degradation of the mechanical properties in presence of hydrogen. In addition, the hydrogen-assisted degradation of mechanical properties is influenced by three main local factors: hydrogen concentration, microstructure, and load condition. Hence, the base material (BM) and two different simulated non-tempered as-quenched HAZ microstructures were examined using hydrogen-free and hydrogen-charged tensile specimens. The results indicate that the effect of hydrogen on the degradation is significantly increased in case of the HAZ compared to the BM. In addition, hydrogen has remarkable effect in terms of reduction of ductility. It was ascertained that the degradation of the mechanical properties increases in the order of BM, bainitic HAZ, and the martensitic HAZ. Scanning electron microscope (SEM) investigation showed a distinct change of the fracture topography depended on the microstructure with increasing hydrogen concentration in case of the as-quenched HAZ microstructures. KW - Mechanical properties KW - Pressure vessel steels KW - Heat affected zone KW - Hydrogen KW - Hydrogen embrittlement KW - Low alloy steels PY - 2016 UR - http://link.springer.com/article/10.1007/s40194-016-0325-9 DO - https://doi.org/10.1007/s40194-016-0325-9 VL - 60 IS - 4 SP - 623 EP - 638 PB - Springer-Verlag GmbH CY - Heidelberg, Germany AN - OPUS4-36454 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Häßler, Dustin A1 - Hothan, Sascha ED - Moreyra Garlock, Maria E. ED - Kodur, Venkatesh K.R. T1 - Fire tests of reactive fire protections systems applied to steel tension members with solid circular section N2 - In civil engineering, steel tension members are normally used for bracings, suspensions and underbracing systems. Typically, slim circular solid sections (CSS) are used for such tension members. However, sufficient knowledge about the performance of reactive fire protection systems (RFPS) applied to solid steel tension members has so far been missing. The application of RFPS on such members was not covered by national German approvals (abZ) as well as European technical assessments (ETA) and therefore only possible by approvals in individual case by the building authority. This paper describes the world’s first scientifically investigated fire tests of RFPS applied to steel tension members with CSS. The influence of various parameters such as profile geometry, dry film thickness of the RFPS, level of the load utilization as well as member orientation was tested. In addition, the foaming and cracking behaviour and thermal protection of the RFPS used are investigated and failure mechanisms are identified. To measure the steel temperature of the tension member without weakening the cross-section a special method for the application of thermocouples was developed. The fire tests show that an application of RFPS on steel tension members with solid section is generally possible. However, due to the slim cross-sections and the missing possibility of load distribution within the tension member, high requirements are placed particularly on the effectiveness and reliability of the RFPS. In particular, the testing of mechanically loaded tension members is essential, since the necessary three-dimensional foaming results in the highest stress level for the RFPS. The findings obtained from the performed fire tests are of general nature. Recommendations for the testing and assessment of RFPS applied to steel tension members with solid section are briefly described in this paper and explained in detail in [1] and [2]. Based on this research, the German building authority (DIBt) has defined national approval guidelines for the testing and the assessment of RFPS applied to tension members with solid section. Since November 2015, a general building approval for a RFPS is available in Germany. T2 - 9th International Conference on Structures in Fire CY - Princeton, NJ, USA DA - 08.06.2016 KW - Steel Structure KW - Intumescent Coating KW - Reactive Fire Protection system KW - Fire Tests KW - Tension Member PY - 2016 SN - 978-1-60595-320-5 VL - 9 SP - 1099 EP - 1106 PB - DEStech Publications, Inc. CY - Lancaster, CA, USA AN - OPUS4-36455 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Häßler, Dustin A1 - Hothan, Sascha T1 - Fire tests of reactive fire protection systems applied to steel tension members with solid circular section N2 - Steel tension members with reactive fire protection system have to be tested under mechanical loading. T2 - 9th International Conference on Structures in Fire CY - Princeton, NJ, USA DA - 08.06.2016 KW - Steel members KW - Intumescent coating KW - Reactive fire protection system KW - Tension member KW - Fire tests PY - 2016 AN - OPUS4-36456 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Raedel, Martina A1 - Feldmann, Ines A1 - Bücker, Michael A1 - Kömmling, Anja ED - Roemich, Hannelore ED - Fair, Lauren T1 - Testing bulked adhesives for the Restoration of Stained-Glass Windows N2 - In this study, bulked adhesives were examined regarding changes in properties for their use in the restoration of stained-glass windows. Two epoxy adhesives commonly used in the restoration of flat glass, Araldite® 2020 and Hxtal NYL-1™, were investigated. The adhesives were mixed with various silica-based micro- and nano-particles as fillers. Different tests were carried out on the adhesives with and without fillers in order to characterise their chemical and mechanical properties. The tests included colorimetry, dynamic-mechanical methods of analysis and tests on bending strength. No property changes could be ascertained in the bulked adhesives that would be negative for the restoration of delicate flat glass. T2 - Recent advances in glass and ceramics - ICOM-CC Glass and Ceramics Working Group Interim Meeting CY - Breslau / Wroclaw, Poland DA - 25.05.2016 KW - bulked epoxy adhesives KW - micro-fillers KW - nano-fillers PY - 2016 SN - 978-83-64419-80-5 SP - 155 EP - 163 AN - OPUS4-36457 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 - Stajanca, Pavol A1 - Mihai, L. A1 - Sporea, D. A1 - Negut, D. A1 - Krebber, Katerina T1 - Perfluorinated polymer optical fibers for gamma radiation monitoring N2 - The sensitivity of low loss perfluorinated polymer optical fiber (PF-POF) to gamma radiation is investigated for on line radiation monitoring purposes. The radiation induced attenuation (RIA) of a commercial PF-POF based on Cytop material is measured in the visible spectral region. The fiber RIA shows strong wavelength dependence with rapid increase towards the blue side of the spectrum. The wide range of radiation sensitivities is available via careful selection of appropriate monitoring wavelength. The accessible sensitivities span from 1.99 ± 0.01 dBm⁻¹/kGy measured at 890 nm to 140.9 ± 0.6 dBm⁻¹/kGy measured at 460 nm. The fairly high radiation sensitivity as well as its wide tunability makes the fiber a promising candidate for a broad range of applications. T2 - Sixth European Workshop on Optical Fibre Sensors CY - Limerick, Ireland DA - 31.05.2016 KW - Perfluorinated polymer optical fiber KW - Cytop KW - Gamma radiation KW - Optical fiber sensors KW - Radiation dosimetry PY - 2016 DO - https://doi.org/10.1117/12.2235528 AN - OPUS4-36460 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Stajanca, Pavol A1 - Mihai, L. A1 - Sporea, D. A1 - Negut, D. A1 - Krebber, Katerina ED - Lewis, E. T1 - Perfluorinated polymer optical fiber for gamma radiation monitoring N2 - The sensitivity of low-loss perfluorinated polymer optical fiber (PF-POF) to gamma radiation is investigated for on-line radiation monitoring purposes. The radiation-induced attenuation (RIA) of a commercial PF-POF based on Cytop material is measured in the visible spectral region. The fiber RIA shows strong wavelength dependence with rapid increase towards the blue side of the spectrum. The wide range of radiation sensitivities is available via careful selection of appropriate monitoring wavelength. The accessible sensitivities span from 1.6 ± 0.2 dBm-1/kGy measured at 750 nm to 18.3 ± 0.7 dBm-1/kGy measured at 420 nm. The fairly high radiation sensitivity as well as its wide tunability makes the fiber a promising candidate for a broad range of applications. T2 - Sixth European Workshop on Optical Fibre Sensors CY - Limerick, Ireland DA - 31.05.2016 KW - Perfluorinated polymer optical fiber KW - Cytop KW - gamma radiation KW - optical fiber sensors KW - radiation dosimetry PY - 2016 UR - http://proceedings.spiedigitallibrary.org/proceeding.aspx?articleid=2525047&resultClick=1 DO - https://doi.org/10.1117/12.2235528 VL - 9916 SP - 99160H-1 EP - 99160H-4 PB - SPIE CY - Bellingham, WA, USA AN - OPUS4-36461 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Dudek, Gabriele T1 - Stand der Normung zur Konformitätsbewertung N2 - Überblick über die Normung zur Konformitätsbewertung- (ISO CASCO Toolbox) Revision der ISO/IEC 17025 – Anforderungen an Labors Revision der ISO/IEC 17011 - Anforderungen an Akkreditierungsstellen Revision des ISO Guide 34 (neu: ISO 17034) -Anforderungen an die Kompetenz von Herstellern von Referenzmaterialien T2 - Forum Labormanager/in 2016 CY - Potsdam, Germany DA - 09.06.2016 KW - Normung PY - 2016 AN - OPUS4-36463 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Marzok, Ulrich A1 - Müller, Ralf A1 - Reinsch, Stefan A1 - Gaber, Martin A1 - Welter, T. A1 - Deubener, J. T1 - Bestimmung der H2-Permeabilität von Gläsern mit der VHE-Methode N2 - Die Entwicklung von Wasserstoffbarrieren aus Glas erfordert die genaue Messung geringster H2-Permeabililtäten. Bisherige Untersuchungen haben gezeigt, dass die VHE-Pulvermethode diesbezüglich eine besonders hohe Empfindlichkeit bietet. Hierbei wird die isotherme Gasabgabe aus sphärischen Partikeln im Rahmen klassischer Diffusionsmodelle gefittet und daraus der Diffusionskoeffizient bestimmt. Für die Untersuchung von Gläsern mit möglichst geringer H2-Permeabilität ist jedoch eine Validierung der Genauigkeit der Methode notwendig. Vor diesem Hintergrund erfolgte die numerische Modellierung der H2-Abgabe mit Hilfe des Programms COMSOL Multiphysics®. Im Poster wird der Einfluss der Korngrößenverteilung der Glaspulverpartikel, der Partikelform sowie der Effekt einer nichthomogenen H2-Startverteilung auf die mittels Pulvermethode ermittelten Diffusionskoeffizienten diskutiert. T2 - 90. Glastechnische Tagung (Deutsche Glastechnische Gesellschaft e.V.) CY - Goslar, Germany DA - 06.06.2016 KW - Wasserstoffpermeation KW - Glas KW - Vakuumheißextraktion KW - Pulvermethode KW - Simulation PY - 2016 AN - OPUS4-36528 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Sproesser, Gunther A1 - Pittner, Andreas A1 - Rethmeier, Michael A1 - Chang, Y.-J. A1 - Finkbeiner, M. T1 - Energy efficiency and environmental impacts of high power gas metal arc welding N2 - Single wire Gas Metal Arc Welding (SGMAW) and high power Tandem GMAW (TGMAW) are evaluated with respect to energy efficiency. The key performance indicator Electrical Deposition Efficiency is applied to reflect the energy efficiency of GMAW in different material transfer modes. Additionally, the wall-plug efficiency of the equipment is determined in order to identify the overall energy consumption. The results show that energy efficiency as well as economic process performance can be significantly increased by application of tandem processes. A comparative Life Cycle Assessment of a 30 mm thick weld is conducted to investigate the influences of the energy efficiency on the environmental impacts. Environmental burdens in the categories Global Warming Potential, Acidification Potential, Eutrophication Potential and Photochemical Ozone Creation Potential can be reduced up to 11% using an energy efficient TGMAW process T2 - IIW Intermediate Meeting Commission I, IV, XII / SG 212 CY - Genova, Italy DA - 07.03.2016 KW - Life cycle assessment (LCA) KW - Energy efficiency KW - High power welding KW - Tandem gas metal arc welding PY - 2016 AN - OPUS4-36535 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Sproesser, Gunther A1 - Pittner, Andreas A1 - Rethmeier, Michael T1 - Sustainable welding production N2 - The project Sustainable Welding Production is presented with its motivation, results and impact as well as with demonstrator case study T2 - 23rd Conference on Life Cycle Engineering CY - Berlin, Germany DA - 22.052016 KW - Gas metal arc welding KW - Hybrid laser arc welding KW - High power welding KW - Energy efficiency KW - Life cycle assessment PY - 2016 AN - OPUS4-36536 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 - Investigations concerning the maximum filling degree of dangerous goods packagings for hazardous liquids N2 - Abstract: The dangerous goods regulations UN/ADR 6.1.5.5.4 a) prescribe a maximum filling degree for determining the test pressure for the hydraulic pressure test by real measurements. The assumption is that the maximum filling degree of the liquid phase is the worst case concerning the gauge pressure. Therefore the main objective of this study is to investigate the effect of the filling degree on the gauge pressure. Gauge pressure measurements and calculations for different substances were carried out at different filling degrees for a steel drum and a steel jerrican (heating-up from 15 °C to 55 °C). The assumption that the maximum filling degree is the most critical is only valid for relatively rigid packagings: If the relative expansion of the packaging is smaller than the volume increase of the liquid phase due to heating-up, the gauge pressure increases with increasing filling degree. But the opposite is true for relatively flexible packagings: If the relative expansion of the packaging exceeds the relative volume expansion of the liquid, the gauge pressure increases for decreasing filling degrees. The current regulations for the hydraulic test pressure determination at a maximum filing degree do not lead to the intended safety level. For a lower level than the maximum filling degree, the prescribed safety factor of 1.5 is not respected. Under transport conditions it is possible that the inner gauge pressure exceeds the test pressure. This can result in a failure of the packaging. There is a need to reconsider the regulations. T2 - 20th IAPRI World Conference on Packaging CY - Campinas, Brazil DA - 12.06.2016 KW - Gefahrgutverpackungen KW - Überdruck KW - Füllgrad PY - 2016 AN - OPUS4-36543 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Geißler, Daniel A1 - Hildebrandt, N. T1 - Recent developments in Förster resonance energy transfer (FRET) diagnostics using quantum dots N2 - The exceptional photophysical properties and the nanometric dimensions of colloidal semiconductor quantum dots (QD) have strongly attracted the bioanalytical community over the last approximately 20 y. In particular, the integration of QDs in the analysis of biological components and interactions, and the related diagnostics using Förster resonance energy transfer (FRET), have allowed researchers to significantly improve and diversify fluorescence-based biosensing. In this TRENDS article, we review some recent developments in QD-FRET biosensing that have implemented this technology in electronic consumer products, multiplexed analysis, and detection without light excitation for diagnostic applications. In selected examples of smartphone-based imaging, single- and multistep FRET, steady-state and time-resolved spectroscopy, and bio/chemiluminescence detection of QDs used as both FRET donors and acceptors, we highlight the advantages of QD-based FRET biosensing for multiplexed and sensitive diagnostics. KW - Fluorescence spectroscopy and imaging KW - Multiplexing immunoassay KW - Nanoparticle KW - DNA/RNA KW - BRET/CRET PY - 2016 DO - https://doi.org/10.1007/s00216-016-9434-y SN - 1618-2642 SN - 1618-2650 VL - 408 IS - 17 SP - 4475 EP - 4483 PB - Springer-Verlag CY - Berlin, Heidelberg AN - OPUS4-36546 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Grunewald, Thomas A1 - Grätz, Rainer A1 - Holländer, L. T1 - Ist Edelstahl wirklich funkenärmer als unlegierter Stahl? N2 - Experimentelle Untersuchungen zu streifenden Schlägen mit verschiedenen Edelstahlsorten in explosionsfähigen Atmosphären, jeweils bestehend aus Wasserstoff, Acetylen, Ethylen bzw. Propan mit Luft, haben gezeigt, dass deren Zündwahrscheinlichkeit sowohl von der Art des Brenngas-Gemisches als auch der Höhe der kinetischen Schlagenergie abhängt. Ein Einfluss des Chromgehaltes im Edelstahl auf die Zündwahrscheinlichkeit durch mechanisch erzeugte Schlagvorgänge konnte in dem untersuchten Bereich des Chromgehaltes nicht nachgewiesen werden, obwohl ein steigender Chromgehalt die Oxidationsfähigkeit abgetrennter Partikel erhöhter Temperatur tatsächlich senkt. Ferner haben weitere Werkstoffeigenschaften wie die Wärmeleitfähigkeit, spezifische Wärmekapazität, Dichte und Härte einen Einfluss auf die Zündwahrscheinlichkeit mechanischer Edelstahl-Schlagvorgänge bei Wasserstoff/Luft-Gemischen. Mit steigender Wärmeleitfähigkeit des Edelstahls sinkt die Zündwahrscheinlichkeit. Für die spezifische Wärmekapazität, Dichte und Härte konnte kein Einfluss nachgewiesen werden. Für Schlagvorgänge wurden in der Norm EN 13463-1:2009 (DIN, 2009) Grenzwerte für die maximale kinetische Schlagenergie festgelegt, unterhalb derer die Entstehung einer wirksamen Zündquelle als unwahrscheinlich angenommen werden kann. Dabei wurde zwischen Schlagvorgängen mit funkenarmen Metallen, wie z. B. Kupfer, Messing, und Schlagvorgängen mit sogenannten „sonstigen Werkstoffen“ unterschieden. Die Grenzwerte dieser sonstigen Werkstoffe resultieren aus Versuchen der BAM mit unlegiertem Baustahl. Bei solchen Schlagvorgängen wird von Oxidationsprozessen einzelner Partikel mit dem Luftsauerstoff ausgegangen, die das Gasgemisch aufgrund des hohen Temperaturanstiegs entzünden. In industriellen Anwendungen wie zum Beispiel der chemischen Industrie wird jedoch statt ferritischem Stahl überwiegend Edelstahl verwendet. Im Allgemeinen gilt mit Chrom hochlegierter Edelstahl bei Schlagvorgängen gegenüber ferritischem Stahl als funkenärmer, da die Oxidationsfähigkeit von Edelstahlpartikeln mit steigendem Chromgehalt abnimmt. Bei den Schlagversuchen der BAM konnte zwar eine sinkende Oxidationsfähigkeit der Partikel, aber keine abnehmende Zündwirksamkeit von Edelstählen mit steigendem Chromgehalt beobachtet werden. T2 - 14. BAM-PTB-Kolloquium zur chemischen und physikalischen Sicherheitstechnik CY - BAM, Berlin, Germany DA - 14.06.2016 KW - Mechanisch erzeugte Funken KW - Nichtelektrischer Explosionsschutz KW - Schlagfunken KW - Funken PY - 2016 AN - OPUS4-36548 LA - deu 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 - CONF A1 - Ebell, Gino T1 - Merkblatt B 03 der DGZfP - Ausgabe April 2014 N2 - Erörterung des Merkblatte B03 zur Durchführung von Potentialfeldmessungen an Stahlbetonbauwerken. T2 - Lehrgang zum Erwerb der Sachkunde zur Durchführung von Potentialfeldmessungen CY - Aachen, Germany DA - 08.06.2016 KW - Potentialfeldmessung PY - 2016 AN - OPUS4-36551 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Ebell, Gino T1 - Potentialmessung im Stahlbetonbau N2 - Durchführung von Potentialfeldmessungen im Stahlbetonbau. T2 - Vorlesung TU-Berlin CY - Berlin, Germany DA - 15.06.2016 KW - Potentialfeldmessung KW - Korrosion PY - 2016 AN - OPUS4-36552 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Gook, S. A1 - Gumenyuk, Andrey A1 - Rethmeier, Michael A1 - El-Batahgy, A.M. T1 - Laser and hybrid laser-arc welding of cryogenic 9 % NI Steel N2 - Heat treated 9%Ni steel is considered the most suitable and economic material for construction of large-size liquefied natural gas (LNG) storage tanks which operate at cryogenic temperatures (-196°C). Strength above 700 MPa as well as a minimum impact value of 60 J are required to ensure reliable operation of the LNG tanks at operating temperature. Conventional arc welding processes, including shielded metal arc welding, gas metal arc welding, gas tungsten arc welding and submerged arc welding, are currently used in construction of LNG tanks. Ni based filler wire is the preferred filler metal of choice in LNG tank construction. The main problem with this choice is the lower mechanical properties, particularly tensile strength of the weld metal. To compensate, the wall thickness needs to be excessively thick to ensure the strength of the welded structures. Ni based filler material is expensive and a large quantity is needed to fill the multi-pass weld grooves. These factors significantly add to the cost in the fabrication of LNG storage tanks. For these reasons, exploration of new welding technologies is a priority. A big potential can be seen in laser based welding techniques. Laser beam welding results in much smaller fusion zone with chemical composition and mechanical properties similar to that of the base material. Laser welding is a much faster process and allows for a joint geometry which requires less filler material and fewer welding passes. The advantages of laser welding can help to overcome the problems pointed out above. Trials of autogenous laser welding, laser cold-wire welding and hybrid laser-arc welding conducted on the 9%Ni steel are presented in this paper. Chemical composition of the weld metal as well as effects of welding parameters on the weld formation, microstructure and tensile strength is discussed. Filler wire penetration depth as well as character of its distribution in the narrow laser welds was examined using EPMA - electron probe microanalysis. KW - hardness KW - cryogenic steel KW - laser welding KW - microstructure KW - tensile strength PY - 2016 UR - http://gns.mephi.ru/sites/default/files/journal/file/en.2016.1-4.pdf SN - 2499-9733 VL - 1 IS - 18 SP - 34 EP - 45 PB - Research Nuclear University MEPHl CY - Moskau, Russia AN - OPUS4-36553 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wöhlecke, Andreas A1 - Müller, Werner Wolfgang T1 - Aktuelle Themen aus dem BAM-Fachbeirat und von der Zulassungsstelle N2 - In diesem Beitrag soll in Kürze darüber informiert werden, welche Themen und Fragestellun-gen den Fachbeirat der BAM, seine Arbeitsgruppen und die BAM beschäftigt haben. Bereits in den letzten Jahren wurde an dieser Stelle über die Anforderungen an Kunststoff Drän-elemente berichtet. Vor dem Hintergrund unserer Beiträge zu diesem Thema, kam eine in-tensive Fachdiskussion im Fachbeirat der BAM und in weiteren Fachgremien in Gang. So wurden die Bemessungsgrundsätze der DGGT (Deutsche Gesellschaft für Geotechnik), die GDA (Geotechnik der Deponien und Altlasten) E (Empfehlung) 2-20 (Entwässerungsschich-ten in Oberflächenabdichtungssystemen), in einigen Punkten angepasst. Eine Musterverle-geanleitung für Kunststoff Dränelemente wurde erarbeitet. Der aktuelle Bearbeitungsstand soll hier vorgestellt werden. In diesem Zusammenhang wurde ein Untersuchungsprogramm zum Einfluss von Überlappstößen auf das Wasserableitvermögen von Kunst-stoff Dränelementen angestoßen. Die Ergebnisse sollen hier in Kürze vorgestellt und die Bedeutung für die Abminderungsfaktoren und damit für die Bemessung erläutert werden. Zu welchem Zeitpunkt muss ein Kunststoff Dränelement überbaut werden und welche weiteren Regelungen müssen hier beachtet werden? Was steckt eigentlich hinter diesen strengen Regelungen? Diese Fragen sollen im Folgenden diskutiert werden. Die Deponieverordnung (DepV) fordert eine Akkreditierung der fremdprüfenden Stellen nach verschiedenen Normen. Die fachlichen Anforderungen an den „Fremdprüfer-Kunststoff“ legt die Richtlinie Fremdprüfer der BAM fest. Um diese Anforderungen im Akkreditierungsprozess ausreichend berücksichtigen zu können, wurde nun eine sogenannte DAkkS Regel erarbeitet, die die Anforderungen der Richtlinie spiegelt. Über den aktuellen Bearbeitungsstand soll berichtet werden. Auch über die aktuelle Arbeit in Zusammenhang mit den Kunststoffdichtungsbahnen (KDB) soll berichtet werden. Der Prüfhinweis B14 (Bestimmung der Maßhaltigkeit von geosyntheti-schen Dichtungsbahnen aus Polyethylen hoher Dichte (PEHD)) wurde überarbeitet. Voran-gegangen war eine intensive Entwicklung der Prüfeinrichtung sowie ausgiebige Ringversuche im AK GWS (Arbeitskreis Grundwasserschutz). In diesem Zusammenhang wurden neue Anforderungen an die Produkte gestellt. Die Hintergründe dazu sollen kurz vorgestellt werden. Die DVS (Deutscher Verband für Schweißen und verwandte Verfahren) Richtlinie 2225-4 regelt das Schweißen der KDB auf der Deponiebaustelle. Werden KDB im strukturierten Bereich miteinander verschweißt, werden die Strukturen in der Regel vorher abgetragen. Die DVS Richtlinie 2225-4 sieht unter bestimmten Voraussetzungen von einem Abtragen der Strukturen ab. Vor diesem Hintergrund wurde ein Untersuchungsprogramm initiiert, das die Auswirkungen aufzeigen soll. Der Bearbeitungsstand wird vorgestellt. T2 - 12. Leipziger Deponiefachtagung - Planung, Bau, Betrieb, Stilllegung, Nachsorge und Nachnutzung von Deponien CY - Leipzig, Germany DA - 08.03.2016 KW - Deponieabdichtungen KW - Deponieverordnung KW - Geokunststoffe KW - Qualitätsmanagement KW - Kunststoff-Dränelemente PY - 2016 AN - OPUS4-36498 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Müller, Werner Wolfgang A1 - Tarnowski, C. A1 - Wöhlecke, Andreas A1 - Zanzinger, H. ED - Kelsey, C. T1 - The "Zero Leakage" approach for landfill liner and capping systems N2 - An approach to achieve “zero leakage” is discussed with respect to the experience in Germany, where strict regulations for landfill lining and capping systems have been developed and issued because of large environmental problems related to landfills that accumulated in the 1970’s and 1980’s. Using a thick, high quality HDPE geomembrane (GMB), which is installed free of residual waves and wrinkles in intimate contact with a compacted clay liner (CCL) or geosynthetic clay liner (GCL) of very low permeability, by a qualified, experienced, well equipped and properly third-party controlled installer and which are protected by heavy protection layers designed with respect to long-term performance of the GMB, may result in a liner or capping system of practically no leakage. This is demonstrated by analyzing results of measurements obtained from permanently installed leak detection systems in combination with HDPE GMBs. The survey is based on 32 German landfills with 1,276,500 m² of installed HDPE GMB. T2 - GeoAmericas 2016 - 3rd Pan-American Conference on Geosynthtics CY - Miami Beach, FL, USA DA - 10.04.2016 KW - Geomembanes KW - Installation KW - Welding KW - Quality management PY - 2016 SN - 978-0-9884772-2-3 VL - 1 SP - 441 EP - 453 PB - Minerva - Technology, Resources, and Information CY - Jupiter, Florida, USA AN - OPUS4-36499 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Traub, Heike A1 - Drescher, Daniela A1 - Büchner, T. A1 - Zeise, Ingrid A1 - Kneipp, Janina A1 - Jakubowski, Norbert T1 - Studying cellular uptake and processing of nanoparticles by LA-ICP-MS N2 - In recent years, elemental imaging of biological samples using laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) is gaining in importance. Latest improvements regarding spatial resolution (down to 1 µm) and washout time make LA-ICP-MS particularly interesting for single cell analysis. Many current nanomaterials can serve as contrast agents in cellular or tissue imaging, drug delivery vehicles or therapeutics, whereas others can cause toxic effects. In order to evaluate nano-bio interactions, the number of nanoparticles (NPs) inside cells as well as their localisation within cellular substructures is of particular interest. LA-ICP-MS was used to study the NP pathway from uptake, via intracellular processing up to cell division. Fibroblast cells were incubated with different metallic NPs under varying experimental conditions. For LA analysis the cells were fixed with formaldehyde and dried. Our results show that LA-ICP-MS is able to localise NP aggregates within cellular substructures. The NPs accumulate in the perinuclear region in the course of intracellular processing, e.g. multivesicular fusion and endosomal maturation, but do not enter the nucleus [1, 2]. A strong dependence of NP uptake on concentration and incubation time was found. Additionally, the number of NPs internalized by individual cells was determined and variations within the cell population became visible. A new laser ablation system providing a short washout time (50 ms) together with small spot sizes (< 4 µm) and high repetition rates allows high spatial resolution applications. First results of cell imaging will be shown. The findings demonstrate the potential of LA-ICP-MS enabling insight into NP uptake and intracellular distribution dependent on experimental parameters. T2 - 8th Nordic Conference on Plasma Spectrochemistry CY - Loen, Norway DA - 05.06.2016 KW - Imaging KW - LA-ICP-MS KW - Cell KW - Nanoparticles PY - 2016 AN - OPUS4-36500 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wöhlecke, Andreas A1 - Müller, Werner Wolfgang ED - Al-Akel, S. T1 - Aktuelle Themen aus dem BAM-Fachbeirat und von der Zulassungsstelle N2 - In diesem Beitrag soll in Kürze darüber informiert werden, welche Themen und Fragestellun-gen den Fachbeirat der BAM, seine Arbeitsgruppen und die BAM beschäftigt haben. Bereits in den letzten Jahren wurde an dieser Stelle über die Anforderungen an Kunststoff Drän-elemente berichtet. Vor dem Hintergrund unserer Beiträge zu diesem Thema, kam eine in-tensive Fachdiskussion im Fachbeirat der BAM und in weiteren Fachgremien in Gang. So wurden die Bemessungsgrundsätze der DGGT (Deutsche Gesellschaft für Geotechnik), die GDA (Geotechnik der Deponien und Altlasten) E (Empfehlung) 2-20 (Entwässerungsschich-ten in Oberflächenabdichtungssystemen), in einigen Punkten angepasst. Eine Musterverle-geanleitung für Kunststoff Dränelemente wurde erarbeitet. Der aktuelle Bearbeitungsstand soll hier vorgestellt werden. In diesem Zusammenhang wurde ein Untersuchungsprogramm zum Einfluss von Überlappstößen auf das Wasserableitvermögen von Kunst-stoff Dränelementen angestoßen. Die Ergebnisse sollen hier in Kürze vorgestellt und die Bedeutung für die Abminderungsfaktoren und damit für die Bemessung erläutert werden. Zu welchem Zeitpunkt muss ein Kunststoff Dränelement überbaut werden und welche weiteren Regelungen müssen hier beachtet werden? Was steckt eigentlich hinter diesen strengen Regelungen? Diese Fragen sollen im Folgenden diskutiert werden. Die Deponieverordnung (DepV) fordert eine Akkreditierung der fremdprüfenden Stellen nach verschiedenen Normen. Die fachlichen Anforderungen an den „Fremdprüfer-Kunststoff“ legt die Richtlinie Fremdprüfer der BAM fest. Um diese Anforderungen im Akkreditierungsprozess ausreichend berücksichtigen zu können, wurde nun eine sogenannte DAkkS Regel erarbeitet, die die Anforderungen der Richtlinie spiegelt. Über den aktuellen Bearbeitungsstand soll berichtet werden. Auch über die aktuelle Arbeit in Zusammenhang mit den Kunststoffdichtungsbahnen (KDB) soll berichtet werden. Der Prüfhinweis B14 (Bestimmung der Maßhaltigkeit von geosyntheti-schen Dichtungsbahnen aus Polyethylen hoher Dichte (PEHD)) wurde überarbeitet. Voran-gegangen war eine intensive Entwicklung der Prüfeinrichtung sowie ausgiebige Ringversuche im AK GWS (Arbeitskreis Grundwasserschutz). In diesem Zusammenhang wurden neue Anforderungen an die Produkte gestellt. Die Hintergründe dazu sollen kurz vorgestellt werden. Die DVS (Deutscher Verband für Schweißen und verwandte Verfahren) Richtlinie 2225-4 regelt das Schweißen der KDB auf der Deponiebaustelle. Werden KDB im strukturierten Bereich miteinander verschweißt, werden die Strukturen in der Regel vorher abgetragen. Die DVS Richtlinie 2225-4 sieht unter bestimmten Voraussetzungen von einem Abtragen der Strukturen ab. Vor diesem Hintergrund wurde ein Untersuchungsprogramm initiiert, das die Auswirkungen aufzeigen soll. Der Bearbeitungsstand wird vorgestellt. T2 - 12. Leipziger Deponiefachtagung CY - Leipzig, Germany DA - 08.03.2016 KW - Deponieabdichtungen KW - Schweißen KW - Geokunststoffe KW - Kunststoffdichtungsbahnen PY - 2016 SN - 978-3-943443-37-0 VL - 12 SP - 34 EP - 45 PB - HTWK - Hochschule für Technik, Wirtschaft und Kultur Leipzig CY - Leipzig, Germany AN - OPUS4-36502 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Marzok, Ulrich A1 - Müller, Ralf A1 - Reetz, R. A1 - Trunkhardt, M. T1 - High-temperature laser profilometry N2 - Advanced methods for 3D green density characterization like computed tomography and 3D FE sinter modeling can be utilized for increasing the reliability of sintered components. The experimental in situ observation of sin-tering, however, is currently restricted to silhouette methods, i.e. heating microscopy. For complex shaped sam-ples, in situ shape screening during shrinkage would allow better validation of 3D sinter simulation models. Further, by revealing temporary sinter warpage, 3D high-temperature shape screening would allow to locate potential defects of complex sintered components. Against this background, BAM developed a testing device for in situ 3D high-temperature shape screening for ceramic and glass-ceramic tapes up to 1000°C [1-3]. Current work is focused on dropping this restriction in sample shape and temperature. The poster illustrates the current state of this work and possible applications of the method e.g. in detecting sinter warpage of metallized glass-ceramic LTCC tapes. T2 - 90. Glastechnische Tagung (Deutsche Glastechnische Gesellschaft e.V.) CY - Goslar, Germany DA - 06.06.2016 KW - Laser profilometry KW - 3D High-temperature shape screening KW - Sintering PY - 2016 AN - OPUS4-36510 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Resch-Genger, Ute A1 - Grabolle, Markus A1 - Starke, M. T1 - Highly fluorescent dye-nanoclay hybrid materials made from different dye classes N2 - Nanoclays like laponites, which are commercially avaible in large quantities for a very moderate price, provide a facile solubilization strategy for hydrophobic dyes without the need for chemical functionalization and can act as a carrier for a high number of dye molecules. This does not require reactive dyes, amplifies fluorescence signals from individual emitters due to the high number of dyes molecules per laponite disk, and renders hydrophobic emitters applicable in aqueous environments. Aiming at the rational design of bright dye-loaded nanoclays as a new class of fluorescent reporters for bioanalysis and material sciences and the identification of dye structure−property relationships, we screened a series of commercial fluorescent dyes, differing in dye class, charge, and character of the optical transitions involved, and studied the changes of their optical properties caused by clay adsorption at different dye loading concentrations. Upon the basis of our dye loading density-dependent absorption and fluorescence measurements with S2105 and Lumogen F Yellow 083, we could identify two promising dye−nanoclay hybrid materials that reveal high fluorescence quantum yields of the nanoclay-adsorbed dyes of at least 0.20 and low dye self-quenching even at high dye-loading densities of up to 50 dye molecules per laponite platelet. KW - nanoclay KW - laponite KW - fluorescence KW - organic dye KW - carrier system KW - fluorescent reporter KW - screening PY - 2016 DO - https://doi.org/10.1021/acs.langmuir.5b04297 SN - 0743-7463 VL - 2016 IS - 32 SP - 3506 EP - 3513 PB - Amer Chemical SOC CY - Washington, DC, USA AN - OPUS4-36511 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Erwamati, F. U. A1 - Pratapa, S. A1 - Suasmoro, S. A1 - Hübert, Thomas A1 - Banach, Ulrich T1 - Preparation and structural study of Mg1−xZnxTiO3 ceramics and their dielectric properties from 1 Hz to 7.7 GHz N2 - A series of Mg₁₋ₓZnₓTiO₃, x = 0–0.5 (MZT0–MZT0.5) ceramics was synthesised and characterised. The dielectric properties of the samples in the frequency range of 1 Hz – 7.7 GHz were explored using three different methods: a contacting electrode method, a parallel-plate method and a perturbed resonator method. The electrical properties in the space charge and dipolar polarisation frequency ranges are discussed in relation to the phase composition and microstructure data. Differences in the zinc Substitution divided the dielectrics into two groups, namely MZT0-MZT0.2 and MZT0.3–MZT0.5, each with different amount of a main Mg₁₋ₓZnₓTiO₃ solid solution phase and a secondary solid solution phase. Zinc substitution promoted the density of the ceramics, improved the purity of the main phase and increased the permittivity for frequencies up to 10⁸ Hz, but reduced the permittivity in the microwave range. In the MZT0.3–MZT0.5 samples, for frequencies less than 1 MHz the quality (Q x ƒ) factors were lower and log σ ₐ.c, the AC conductivity, was higher than for the MZT0–MZT0.2 samples. Above 10 MHz, the (Q x ƒ) factors and log σ ₐ.c of the two groups were similar. KW - Mg1-xZnxTiO3 KW - Space charge polarisation KW - Dipole polarisation KW - Microwave frequency KW - Dielectric properties PY - 2016 DO - https://doi.org/10.1007/s10854-016-4610-6 SN - 0957-4522 VL - 27 IS - 7 SP - 6637 EP - 6645 PB - Springer CY - Dordrecht, Netherlands AN - OPUS4-36466 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Gottlieb, Cassian A1 - Grothe, Sven A1 - Wilsch, Gerd T1 - Cluster algorithm for the evaluation of heterogeneous materials by LIBS N2 - The laser-induced breakdown spectroscopy (LIBS) is a fast method to provide multi-elemental analysis of any sample. At the Federal Institute for Materials Research and Testing (BAM) the LIBS technique is applied on building materials to measure ingress profiles of harmful species like chloride and alkalis. The ingress depth and the quantitative amount is important for the evaluation of the potential for damage processes like the alkali-silica reaction or chloride-induced corrosion. Concrete as an example is a highly heterogeneous material with 1/7 cement (major component CaO) and 6/7 aggregates (SiO2) with different grain sizes. Due to a scanning procedure a two dimensional element distribution of a concrete surface can be measured. In order to have an automated Separation method to evaluate heterogeneous materials, different cluster algorithm have been tested. Best results have been achieved with the Expectation-Maximization-Algorithm (EM-Algorithm). T2 - Chemometrics in analytical chemistry CY - Barcelona, Spain DA - 06.06.2016 KW - LIBS KW - Concrete KW - Multivariate analysis PY - 2016 AN - OPUS4-36471 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Denkler, Tilman T1 - BAM-CCAI Fachworkshop zu einer Deutsch-Chinesischen Forschungskooperation N2 - Entwicklungsperspektiven der Konformitätsbewertung und Akkreditierung in Deutschland • Zielstellung der Studie • Methodischer Ansatz • Ergebnisse zur volkswirtschaftlichen Bedeutung der Konformitätsbewertung und der Akkreditierung • Schlussfolgerungen T2 - CCAI-Workshop CY - Berlin, Germany DA - 23.05.2016 KW - Studie Technopolis KW - Akkreditierung KW - Konformitätsbewertung PY - 2016 AN - OPUS4-36474 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Krüger, Oliver T1 - Phosphorrückgewinnung - ein wichtiger Beitrag zur Kreislaufwirtschaft N2 - Phosphor ist ein für alle Lebewesen essentielles Element und in seinen Funktionen nicht zu ersetzen. Der Bedarf wird aus der Nahrung gedeckt, daher wird Phosphor letztendlich durch Ackerbau den Böden entzogen. Der Nährstoff muss ersetzt werden, um dauerhafte Landwirtschaft zu ermöglichen. Das geschieht zum einen durch den Einsatz von Wirtschaftsdüngern, aber zu einem großen Teil auch durch Mineraldünger. Das hierfür benötigte Rohphosphat wird bergmännisch aus fossilen Lagerstätten gewonnen. Die entsprechende Reichweite wird auf über 300 Jahre geschätzt. Daher besteht zwar keine unmittelbare Gefahr, dass dieser lebenswichtige Nährstoff zu Neige geht, es bestehen jedoch erhebliche Versorgungsrisiken. Zum einen ist Europa nahezu vollständig von Importen abhängig und damit auch Schwankungen der Weltmarktpreise ausgesetzt. Darüber hinaus liegen Förderung und Reserven von Rohphosphaten entweder in Ländern mit hohem Eigenbedarf (USA, China) oder in politisch instabilen Regionen (Marokko, West Sahara). Außerdem sind viele Rohphosphate mit Schwermetallen wie Uran, Thorium und Cadmium belastet. Das Umweltbundesamt schätzt, dass jährlich mehr als 160 t Uran durch Mineraldünger auf deutsche Ackerflächen ausgebracht werden. Rückgewinnung von Phosphor könnte helfen, diese Probleme zu reduzieren. Ein bedeutendes Potential dafür stellt der Abwasserstrom dar. Die Menge an Phosphor darin wird deutschlandweit auf etwa 70.000 t jährlich geschätzt. Das entspricht etwa der Hälfte der Menge an Phosphor, die derzeit für Mineraldünger benötigt wird. Der Vortrag würde sich mit möglichen Prozessen der Rückgewinnung, deren Wirtschaftlichkeit und Herausforderungen der Analytik befassen: - in den letzten Jahren wurden zahlreiche Verfahren zur Rückgewinnung von Phosphor aus verschiedensten Phasen der Abwasserreinigung entwickelt (wässrige Phase, Klärschlamm, Klärschlammasche). Ausgewählte Verfahren würden vorgestellt und bewertet. - für einen Einsatz der so gewonnenen Recyclingphosphate als Düngemittel muss die Schadstofffreiheit und Pflanzenverfügbarkeit der Nährstoffe sichergestellt werden. Dazu ist zu prüfen, ob die zurzeit gängigen Verfahren der Probenvorbereitung und Analytik auch auf Recyclingphosphate anwendbar sind. Das gilt neben der Bioverfügbarkeit von Phosphor besonders für Schadstoffe, da die Recyclingdünger aus Abfallmaterialien gewonnen werden, die stark belastet sein können. Das gilt besonders für die speziesspezifische Analytik von Chrom (Chrom (VI) vs. Chrom (III)) in verschiedenen Matrices. T2 - Beiratssitzung Themenfeld Umwelt CY - BAM, Berlin, Germany DA - 10.06.2016 KW - Phosphor KW - Rückgewinnung KW - Umweltanalytik KW - Ressourcenschonung PY - 2016 AN - OPUS4-36451 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Lörchner, Dominique A1 - Koch, Matthias A1 - Kroh, L. W. A1 - Köppen, Robert T1 - Simulation metabolischer Oxidationsreaktionen ausgewählter PBFSM mittels EC/MS N2 - Brominated flame retardants (BFRs) comprise a class of structurally diverse compounds that are functionally related and used in materials to reduce the flammability of polymers. From the early 1960s to present day, BFRs have been produced in high volumes and are widely used in plastics, foams and textiles. Due to concerns over their persistence, bioaccumulation and toxicity most of the BFRs of the first generation are banned or restricted, and replaced by new ones. However, based on similar properties these new compounds may also pose a serious risk by causing adverse effects to human health and the environment. These alternative BFRs were grouped into two classes: „novel‟ and „emerging‟ BFRs. Emerging BFRs are defined as compounds that have been identified in any environmental compartments whereas novel BFRs are only detected in materials and/or goods above 0,1 wt.-% (EFSA, 2012). Because of the lack of knowledge about occurrence, physico-chemical properties and environmental behavior, two representatives were selected to investigate their degradation and transformation capability. In order to get a first understanding about the environmental fate and the metabolism of the selected compounds in-vitro studies based on microsomal approaches (Human/Rat liver microsomes) were performed. Additionally, oxidative/ reductive degradation processes were simulated by coupling of an electrochemical cell with mass spectrometric detection to generate and detect the oxidative products. The aim of the presented work is to compare these different kinds of metabolic studies to obtain data concerning the biodegradation and/or biotransformation pathways of these new contaminants. In order to get a first understanding about the environmental fate and the metabolism of the selected compounds in-vitro studies based on microsomal approaches (Human/Rat liver microsomes) were performed. Additionally, oxidative/ reductive degradation processes were simulated by coupling of an electrochemical cell with mass spectrometric detection to generate and detect the oxidative products. The aim of the presented work is to compare these different kinds of metabolic studies to obtain data concerning the biodegradation and/or biotransformation pathways of these new contaminants.zeige mehrzeige weniger N2 - Polybromierte Flammschutzmittel (PBFSM) werden seit den 1960er Jahren zur Herabsetzung der Entflammbarkeit von Polymeren verwendet. Diese stehen auf Grund ihrer potentiell persistenten, bioakkumulierenden sowie toxischen Eigenschaften bis heute im Fokus der Wissenschaft und Gesetzgebung. In den letzten Jahren kam es verstärkt zum Einsatz neuer („emerging“) sowie neuartiger („novel“) PBFSM. Diese Verbindungen wurden bereits in der Umwelt bzw. oberhalb von 0,1 Gew.-% in Bedarfsgegenständen nachgewiesen. Zwei Vertreter, über deren Vorkommen, physikochemischen Eigenschaften und Umwelt-verhalten nur wenig bekannt ist, wurden daher ausgewählt, um das Abbau- und Transformationsverhalten näher zu untersuchen. Um eine Einschätzung über das Umweltverhalten bzw. die Metabolisierung dieser Verbindungen vornehmen zu können, werden sowohl Untersuchungen der cyto-chromabhängigen Biotransformation (Phase I/II) anhand mikrosomaler Ansätze als auch die Simulation oxidativer/reduktiver Abbauprozesse durch die Kopplung aus elektrochemischer Zelle (EC) und massenspektrometrischer Detektion (MS) herangezogen. Ziel der präsentierten Arbeit ist es, ein erstes Verständnis des Umweltverhaltens dieser neuartigen Kontaminanten zu entwickeln, um so eine Bewertung über die toxikologische Relevanz dieser Verbindungen bzw. deren Umwelt-/Bio-Transformationsprodukte geben zu können. T2 - LC-MS in der Umweltanalytik CY - Leipzig, Germany DA - 06.06.2016 KW - Umweltverhalten KW - Polybromierte Flammschutzmittel KW - EC/MS PY - 2016 AN - OPUS4-36452 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Asadujjaman, Asad A1 - Bertin, Annabelle T1 - Aggregation behavior of UCST-Type Poly(Acrylamide-co-Acrylonitrile) copolymer N2 - Thermoresponsive polymers have shown great potential in applications such as bioseparation, drug delivery and diagnostic. Only few thermoresponsive polymers that present an upper critical solution temperature (UCST) in a relevant temperature range, i.e. phase separate from solution upon cooling, have been reported so far. Moreover, the most studied UCST type polymers namely polybetaines are difficult to use under physiological conditions, which significantly restricts their potential applications. Therefore, UCST polymers with sharp and robust phase transition in physiological conditions (in the presence of salts, ions etc.) are highly needed in order to extend the range of applications of this class of polymers. Herein, a robust UCST-type copolymer of acrylamide (AAm) and acrylonitrile (AN) (poly(AAm-co-AN)) was prepared by reversible addition fragmentation chain transfer (RAFT) polymerization and its thermo-induced aggregation behavior in aqueous media was studied. At temperature below the UCST, the copolymer chains were aggregated together. The aggregate size was found to be larger with increasing AN contents and became smaller upon dilution of the copolymer solutions. While above the UCST, the copolymer chains were expanded and weekly associated in solution. The association between the copolymer chains formed smaller aggregates with increasing the AN contents or the dilution of the solutions. A model is proposed to explain such aggregation-association behavior of the Fig. 1. Figure 1. Schematic illustration of the proposed thermos-induced aggregation behavior of the poly(AAm-co-AN) in aqueous solution. T2 - World Congress on Living Polymerizations and Polymers 2016 CY - Budapest, Hungry DA - 29.05.2016 - 03.06.2016 KW - Polymer KW - UCST PY - 2016 AN - OPUS4-36491 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wöhlecke, Andreas A1 - Müller, Werner Wolfgang A1 - Tarnowski, C. A1 - Zanzinger, H. T1 - The “Zero Leakgae” approach for landfill lining and capping systems N2 - An approach to achieve “zero leakage” is discussed with respect to the experience in Germany, where strict regulations for landfill lining and capping systems have been developed and issued because of large environmental problems related to landfills that accumulated in the 1970’s and 1980’s. Using a thick, high quality HDPE geomembrane (GMB), which is installed free of residual waves and wrinkles in intimate contact with a compacted clay liner (CCL) or geosynthetic clay liner (GCL) of very low permeability, by a qualified, experienced, well equipped and properly third-party controlled installer and which are protected by heavy protection layers designed with respect to long-term performance of the GMB, may result in a liner or capping system of practically no leakage. This is demonstrated by analyzing results of measurements obtained from permanently installed leak detection systems in combination with HDPE GMBs. The survey is based on 32 German landfills with 1,276,500 m² of installed HDPE GMB. T2 - GeoAmericas 2016 - 3rd Pan-American Conference on Geosynthtics CY - Miami Beach, Fl, USA DA - 10.04.2016 KW - Deponieabdichtungen KW - Einbau KW - Kunststoffdichtungsbahnen KW - Schweißen KW - Landfill sealing KW - Geomembrane KW - Installation KW - Welding PY - 2016 AN - OPUS4-36496 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Woydt, Mathias A1 - Mohrbacher, H. T1 - Adjusting the functional properties of niobium carbide N2 - The process window and range of functional properties of NbC is wide, because micro-hardness, hot hardness, sliding wear resistance, elastic modulus and toughness can be tailored by the C/Nb ratio, because Nb4C3, Nb6C5 and other short and long range ordered phases occur in the region of homogeneity of NbCx (0,75≤ x ≤1.0) in the binary Phase diagram, and by the type of binder. Further improvements enable the addition of secondary carbides. Supporting results from literature and different grades with varying C/Nb ratio or binder types were illuminated. Thus, the NbC system offers to producers a wider process window, than WC. The impact of these tailored properties on sliding wear and cutting performance was illuminated by tribological and machining results. NbC can be synthesized by carbothermal conversion of Nb2O5 or be metallurgically grown in melts and leached out as coarse NbC cubes. NbC provides comparably lower friction in many relevant tribo-contacts and displays low wear. NbC and Nb2O5 have so far no REACH classification related to human toxicology and are not listed as substances of very high concern contrary to WO3 and Co3O4. T2 - 2016 International Conference on Powder Metallurgy & Particulate Materials CY - Boston, MA, USA DA - 05.06.2016 KW - Niobium carbide KW - NbC KW - Wear KW - Friction PY - 2016 AN - OPUS4-36497 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Sentker, K. A1 - Yildirim, Arda A1 - Knopp, K. A1 - Schönhals, Andreas A1 - Huber, P. T1 - Columnar axial orientation of discotic liquid crystals in nanoporous solids N2 - Successful implementation of an optical polarimetry measurement setup. Due to wall anchoring interactions HAT6 embedded in an untreated alumina membrane exhibits a radial orientation for pore sizes in between 30 nm and 80 nm. Embedded in large membranes, pore size of 180 nm, HAT6 forms the favored hexagonal columnar phase along the pore axis. T2 - 80. Jahrestagung der DPG und DPG-Frühjahrstagung CY - Regensburg, Germany DA - 06.03.2016 KW - Discotic Liquid Crystals KW - Nanoconfinement KW - Orientation PY - 2016 AN - OPUS4-36479 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Mann, Guido A1 - Krüger, Jörg ED - Jitsuno, T. ED - Shao, J. ED - Rudolph, W. T1 - Nanosecond laser damage of optical multimode fibers N2 - For pulse laser materials processing often optical step index and gradient index multimode fibers with core diameters ranging from 100 to 600 μm are used. The design of a high power fiber transmission system must take into account limitations resulting from both surface and volume damage effects. Especially, breakdown at the fiber end faces and self-focusing in the fiber volume critically influence the fiber performance. At least operation charts are desirable to select the appropriate fiber type for given laser parameters. In industry-relevant studies the influence of fiber core diameter and end face preparation on laser-induced (surface) damage thresholds (LIDT) was investigated for frequently used all-silica fiber types (manufacturer LEONI). Experiments on preform material (initial fiber material) and compact specimens (models of the cladding and coating material) accompanied the tests performed in accordance with the relevant LIDT standards ISO 21254-1 and ISO 21254 2 for 1-on-1 and S-on-1 irradiation conditions, respectively. The relation beam diameter vs. LIDT was investigated for fused silica fibers. Additionally, laser-induced (bulk) damage thresholds of fused silica preform material F300 (manufacturer Heraeus) in dependence on external mechanical stress simulating fiber bending were measured. All experiments were performed with 10-ns laser pulses at 1064 and 532 nm wavelength with a Gaussian beam profile. T2 - Pacific Rim Laser Damage 2016 CY - Yokohama, Japan DA - 18.05.2016 KW - laser damage KW - optical fiber KW - nanosecond laser KW - fused silica PY - 2016 DO - https://doi.org/10.1117/12.2238515 VL - 9983 SP - 99830T AN - OPUS4-37140 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Weise, Frank A1 - Meng, Birgit A1 - Pirskawetz, Stephan A1 - Voland, K. T1 - Influence of simultaneous cyclic loading and external alkali supply on the alkali-silica reaction in concrete pavements N2 - In recent years the German motorway network has seen an increase in the occurrence of damage to concrete road surfaces which can be attributed to the alkali-silica reaction (ASR). In view of the often drastically reduced life expectancy of road surfaces due to ASR, research activity in this field has notably increased. Alongside preventative measures in concrete technology, the main research focus up to now has been the development of performance-oriented testing procedures for ASR prevention. This included more specifically the accelerated simulation of climatic effects and external alkali penetration on road surfaces. The effects of mechanical pre-damage resulting from cyclic traffic loading and climatic impact had previously not been taken into consideration. Since 2011, the five-partner research group 1498 sponsored by the German Research Foundation (DFG) has been pursuing research on how simultaneous cyclic loading and external alkali penetration impacts destructive ASR in road surface concretes. The depiction of the myriad degradation and transport processes necessary for an understanding of these effects requires close interaction between experiments and their multi-scale modelling. This paper aims to focus on the aforementioned experiments by means of innovative testing techniques. The research is founded on a series of cyclic fatigue tests performed on large-format beams, both with and without previous application of a sodium chloride (NaCl) solution, with simultaneous tracking of crack development. Subsequently, smaller test specimens were extracted from the pre-damaged beams for further experiments. These included the spatial visualization and quantification of fatigue-induced cracks using micro X-ray 3D-computed tomography (3D-CT). Additionally, the effects of fatigue-induced cracks on alkali transport were investigated using Laser-Induced Breakdown Spectroscopy (LIBS). Subsequent storage of the small-format test specimens, with and without cyclic pre-damage, in an ASR-conducive environment then provided initial findings on the influence of fatigue-induced predamage on the ASR. T2 - 15th International Conference on Alkali-Aggregate reaction (ICAAR 2016) CY - Sao Paulo, Brazil DA - 03.07.2016 KW - concrete pavements KW - alkali-silica-reaction KW - fatigue KW - damage monitoring PY - 2016 SP - Paper 191 AN - OPUS4-37142 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Werner, Daniel A1 - Meng, Birgit A1 - Weise, Frank T1 - Influence of aggregate size on the damage potential of alkali-silica reaction N2 - The susceptibility of different aggregate types used in concrete to ASR is strongly associated with their petrography. The aim of this study is to assess the influence of the aggregate size on the ASR potential, in particular applied to the sand fractions in the size range of 0.125-4 mm. The investigation concept is based on the hypothesis that at a specific particle size reactive aggregates could change their characteristic influence in mitigating ASR instead of promoting it. For the study of the size dependent behaviour mortars are prepared, considering aggregates of different reactivity, including very reactive, slow-late and quasi non-reactive types. The analysis is based on a stepwise substitution concept, in which mortars with a constant overall grain size distribution are compared, while only one size fraction of the non-reactive base aggregate is substituted by a reactive aggregate type of this specific size fraction. For the expansion experiments an accelerated mortar bar test (80°C, immersed in NaOH solution) was applied. The results show that the slow-late reactive greywacke yielded a strong reduction of the expansion below an aggregate size in the range of 0.5-1 mm. On the other side with the very reactive borosilicate glass, the expansions increased steadily with decreasing size. To validate if the acquired expansions were caused by ASR, thin sections were analysed. Mainly, higher expansion values were consistent with extensively more amounts of ASR indicators. T2 - 15th International Conference on Alkali-Aggregate Reaction (ICAAR 2016) CY - Sao Paulo, Brazil DA - 03.07.2016 KW - alkali-silica-reaction KW - building materials KW - concrete KW - durability PY - 2016 SP - Paper 194 AN - OPUS4-37143 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Miccoli, Lorenzo A1 - Fontana, Patrick A1 - Ziegert, C. A1 - Müller, P. ED - Modena, C. ED - da Porto, F. ED - Valluzzi, M. R. T1 - Calibration of partial safety factors for earth block masonry under compression loading N2 - The goal of the present study is to assess the feasibility to develop a first reliable database of materials parameters for Earth Block Masonry (EBM). The database is crucial when defining the materials safety factors. In the first part an experimental campaign of compressive tests were carried out on two types of earth block and two types of earth mortar. The results showed that the mean variation of the compressive strength was remarkably less than expected. This low variation is related to a production with high quality standards of the materials employed. In the second part a partial safety factor for EBM under uniaxial compression was determined through the reliability method. The results proved the reliability of a common calculation method for EBM based on partial safety factors following the current standards. T2 - IB2MAC 2016 - 16th International Brick and Block Masonry Conference CY - Padua, Italy DA - 26.06.2016 KW - earth block masonry KW - partial safety factors KW - uniaxial compression test PY - 2016 SN - 978-1-138-02999-6 SP - 857 EP - 864 PB - CRC Press Taylor & Francis Group CY - London, UK AN - OPUS4-37145 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Wai-Lok Lai, W. A1 - Kind, Thomas A1 - Fung-Chu Sham, J. A1 - Wiggenhauser, Herbert T1 - Correction of GPR wave velocity at different oblique angles between traverses and alignment of line objects in a common offset antenna setting N2 - Estimation of ground penetrating radar's wave velocity in materials is a critical step to accurately estimate depth of embedded line objects in concrete structures, and wetness of material. Errors of velocity are defined as the deviations between the velocities obtained in various oblique angles and those obtained in the traverse normal to the object orientation in a common offset antenna setting. In this paper, we quantified and corrected the errors of such estimation. GPR traverses were designed to travel in various oblique angles θ (90°, 75°, 60° and 45°) relative to the steel bars at 5 cover depths (55 mm, 85 mm, 115 mm, 145 mm and 175 mm). GPR wave velocity at any position within the lateral detection range of steel bars was measured with simple trigonometry in a semi-automated in-house program. It was found that reduction of oblique angles (i.e. θ<90°) causes flatter hyperbolic reflections and the associated errors of velocity can be as much as 30% in the case of an oblique angle 45° before correction. Such errors were corrected after re-scaling the horizontal travel distance with a multiplication factor of sin θ. KW - Ground penetrating radar KW - Oblique angles KW - Hyperbola KW - Velocity error PY - 2016 UR - http://www.sciencedirect.com/science/article/pii/S096386951630007X DO - https://doi.org/10.1016/j.ndteint.2016.03.003 VL - 82 SP - 36 EP - 43 PB - Elsevier Ltd. AN - OPUS4-37146 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Jakubowski, Norbert T1 - ICP-MS with Sector Field Devices N2 - This lecture is an introduction to ICP-MS with a double focusing magnetic sector mass analyzer. It offers fundamental background, a thorough discussion of analytical features, and state of the art information on applications. Different types of double focusing instruments also are considered. Specific topics include fundamental aspects of ICP-MS (physical properties of a double focusing instrument, operational characteristics in comparison with quadrupole instruments); analytical characteristics (spectral and non-spectral interferences, figures of merit in low and high resolution modes, blanks and memory effects, HPLC and GC interfaces), and applications (industrial including ultra-pure reagents and alloys, environmental, geological, and biomedical materials). T2 - Winter Conference on Plasma Spectrochemistry CY - Tucson, Arizona, USA DA - 10.01.2016 KW - High-resolution ICP-MS KW - Figures of merit KW - Interfaces KW - Applications KW - Ultra-trace analysis PY - 2016 AN - OPUS4-37148 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - THES A1 - Häßler, Dustin T1 - Verhalten reaktiver Brandschutzsysteme auf kreisförmigen Zuggliedern aus Blank- und Baustahl N2 - Im Bauwesen werden Zugglieder aus Stahl in der Regel für Aussteifungsverbände, Abhängungen und Unterspannungen von Trägern verwendet. Die dafür verbauten, meist kreisförmigen Vollprofile dienen häufig der Stabilisierung des Tragwerks. Ein Versagen der Stahlzugglieder kann zu einem Einsturz der gesamten Konstruktion führen. Unter Brandeinwirkung verlieren ungeschützte Stahlkonstruktionen aufgrund der schnellen Erwärmung frühzeitig ihre Tragfähigkeit. Durch den Einsatz reaktiver Brandschutzsysteme auf Stahlbauteilen kann deren Erwärmung verlangsamt und dadurch der Feuerwiderstand verbessert werden. Die Optik der oftmals filigranen Stahlzugglieder bleibt dabei im Wesentlichen unverändert. Für die Anwendung reaktiver Brandschutzsysteme auf Stahlzuggliedern mit Vollquerschnitt gibt es derzeit in den allgemeinen bauaufsichtlichen Zulassungen keine Regelungen. Die an der Bundesanstalt für Materialforschung und –prüfung (BAM) durchgeführten experimentellen und numerischen Untersuchungen [35] sowie die darauf aufbauenden Erkenntnisse dieser Dissertation hinsichtlich des Verhaltens reaktiver Brandschutzsysteme auf Stahlzuggliedern mit Vollprofil bilden die Grundlage für eine Erweiterung des Anwendungsbereiches dieser Produkte. Eine Anwendung ist grundsätzlich möglich. Aufgrund der meist für Zugglieder eingesetzten filigranen Vollquerschnitte sowie der in Bezug auf die Tragfähigkeit fehlenden Umlagerungsmöglichkeit werden besonders hohe Anforderungen an die Wirksamkeit und Zuverlässigkeit von reaktiven Brandschutzsystemen gestellt. Anhand der Ergebnisse aus den Brandversuchen sowie theoretischer Betrachtungen ist festzustellen, dass das auf kreisförmigen, zugbeanspruchten Stahlprofilen aufgebrachte reaktive Brandschutzsystem aufgrund der notwendigen dreidimensionalen Ausdehnungsrichtung der höchst möglichen Beanspruchung ausgesetzt ist. Mit Hilfe von Leistungskriterien zur Bestimmung der Tragfähigkeit, welche im Rahmen der Dissertation entwickelt wurden, lassen sich die in Brandversuchen unter axialer Zugbeanspruchung getesteten Stahlzugglieder mit reaktiver Brandschutzbeschichtung in Feuerwiderstandsklassen einordnen. Für die Beurteilung der thermischen Schutzwirkung des reaktiven Brandschutzsystems werden die Erwärmungsgeschwindigkeit, die maximale Stahltemperatur sowie die Rissbildung und das Rissheilungsvermögen der Beschichtung herangezogen. Die Brandversuche haben gezeigt, dass die Profilgeometrie, die Höhe der Trockenschichtdicke der Beschichtung, die Höhe der aufgebrachten Zugbeanspruchung sowie die Orientierungsrichtung der Zugglieder einen wesentlichen Einfluss auf die thermische Schutzwirkung des reaktiven Brandschutzsystems ausüben. Zudem stehen diese Faktoren in gegenseitiger Wechselwirkung. Durch Abstimmung der genannten Einflussgrößen lässt sich die Wirkung der Brandschutzbeschichtung optimieren. Durch die Vielzahl an reaktiven Brandschutzsystemen und die in den Produkten variierende chemische Zusammensetzung ist deren Aufschäumverhalten und thermische Schutzwirkung sehr unterschiedlich und kaum vorhersagbar. Die Wirksamkeit des reaktiven Brandschutzsystems ist daher für Grenzfälle des vom Hersteller definierten Anwendungsbereichs durch Brandversuche zu überprüfen. Empfehlungen zur Durchführung dieser Versuche sind im Forschungsbericht [35] beschrieben. Bei Verwendung von kaltverformtem Blankstahl für Stahlzugglieder mit Vollprofil sind andere Hochtemperatureigenschaften als bei dem typischerweise für Träger und Stützen eingesetzten warmgewalztem Baustahl zu berücksichtigen. Kaltverformter Blankstahl weist gegenüber herkömmlichem Baustahl einen höheren Wärmeausdehnungskoeffizient und andere temperaturabhängige Abminderungsfaktoren für die Stahlfestigkeit auf. Die in experimentellen Untersuchungen für Blankstahl ermittelten Materialeigenschaften können für die Heißbemessung von Zuggliedern mit Vollprofil aus entsprechendem Material verwendet werden. In Kombination mit Temperaturdaten aus Brandversuchen lässt sich mittels eines auf der Grundlage der Finite-Elemente-Methode (FEM) entwickelten numerischen Berechnungsmodells das Trag- und Verformungsverhalten von Zuggliedern realitätsnah berechnen. Vergleiche zur Stablängsverformung von in Brandversuchen getesteten Zuggliedern zeigen eine hohe Übereinstimmung mit den Ergebnissen aus dem im Rahmen der Dissertation neu entwickelten Bemessungsmodell. T3 - BAM Dissertationsreihe - 149 KW - Brandschutz KW - Stahl KW - Reaktive Brandschutzsysteme KW - Numerische Simulation KW - Brandversuche KW - Materialuntersuchung PY - 2016 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-371495 SN - 978-3-9817853-4-0 SN - 1613-4249 VL - 149 SP - 1 EP - 226 PB - Bundesanstalt für Materialforschung und -prüfung (BAM) CY - Berlin AN - OPUS4-37149 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Woydt, Mathias A1 - Mohrbacher, H. A1 - Vleugels, J. A1 - Huang, S. T1 - Niobium carbide for wear protection - tailoring its properties by processing and stoichiometry N2 - Niobium carbide is a hardly explored carbide but its functional profile shows a high potential for wear protection and tribological applications, which are currently dominated by tungsten carbide. Surprisingly little information is available on niobium carbide (NbC). Niobium carbide can be either synthesized by carbothermal conversion of Nb2O5 or be metallurgically grown and leached out. Furthermore, NbC hardmetal grades can be bonded by all known metallic binders and processed and sintered in exactly the same way as WC-based hardmetals. Niobium is today largely available. NbC can be efficiently produced, provides comparably low friction in many relevant tribo-contacts and displays low wear. NbC and Nb2O5 have so far no REACH classification related to human toxicology and are not listed as substances of very high concern contrary to WO3 and Co3O4. This contribution demonstrates the key characteristics of NbC and discusses its sustainability and reliable value chain. KW - niobium carbide KW - wear KW - machining PY - 2016 DO - https://doi.org/10.1016/j.mprp.2015.12.010 SN - 0026-0657 VL - 71 IS - 4 SP - 265 EP - 272 PB - Elsevier Ltd. AN - OPUS4-37150 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Falkenberg, Rainer T1 - Simulation of Environmentally-Assisted Material Degradation by a Thermodynamically Consistent Phase-Field Model N2 - Environmentally-assisted material degradation involves mass transport and mechanical processes interacting in the material. A well-known example is hydrogen-induced stress-corrosion cracking. One major challenge within this scope is the quantification of the coupling mechanisms in question. The computational modeling of environmentally-assisted cracks is the key objective of this investigation and realised within the theory of gradient-extended dissipative continua with lengthscales. The modeling of sharp crack discontinuities is replaced by a diffusive crack model based on the introduction of a crack phase-field to maintain the evolution of complex crack topologies. Within a thermodynamical framework allowing for mechanical and mass transport processes the crack phasefield is capable to model crack initiation and propagation by the finite element method. As complex crack situations such as crack initiation, curvilinear crack patterns and crack branching are usually hard to realise with sharp crack models, they can be assessed without the requirement of a predefined crack path within this method. The numerical modeling of a showcase demonstrates a crack initiation as well as a crack propagation situation with respect to the determination of stress-intensity factors; a crack deviation situation with a curvilinear crack path is modeled by the introduction of a geometrical perturbation and a locally enhanced species concentration. KW - Finite-element method KW - Crack growth KW - Crack initiation KW - Mass transport KW - Phase field model PY - 2016 DO - https://doi.org/10.4028/www.scientific.net/KEM.713.38 SN - 1662-9795 VL - 713 SP - 38 EP - 41 PB - Trans Tech Publications CY - Switzerland AN - OPUS4-37152 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hertwig, Andreas A1 - Rosu, Dana A1 - Ortel, Erik A1 - Kraehnert, R. A1 - Hodoroaba, Vasile-Dan T1 - Measurement of Porous TiO2 Layers with spectroscopic ellipsometry – a multi-method study N2 - By means of an effective medium (EMA) based approach, it is possible to use spectroscopic ellipsometry to determine the mixing ratios between air and material in porous dielectrics and calculate a quantitative value of the porosity for these materials. As this method is model-based, it is very difficult to provide a quantitative measure for the accuracy of porosity values determined by this method. Valuable additional information can often be obtained by combining ellipsometry with other complementary methods. In the present study, the ellipsometry results were validated by Electron Probe Microanalysis (EPMA) with the option of layer analysis (by the socalled “STRATAGem” approach), gravimetry, and electron microscopy. We analysed porous TiO2 thin layers synthesised by means of a template synthesis approach (evaporation induced self assembly). Ellipsometry measurements on porous samples are difficult to analyse due to the complexity of the models necessary. Often it is difficult to decide if the measured data contains enough information to successfully determine the target quantities (mixing ratio, dielectric function of the matrix material). One method to decrease the complexity of the fit and therefore use the measurement data most efficiently is a multi-sample analysis. In the present case, multi-sample analysis was used for determining the porosity factors of the individual layers while using one common set of dielectric function values for the matrix in all cases. While the results of the fit analysis in this case can be used to show the feasibility and also the limitations of the multi-method approach, the porosity values themselves show a promising agreement between the independent methods. It can therefore be concluded that determining porosity values with ellipsometry is in accordance to other methods to the level of accuracy provided by the complementary methodologies. T2 - International conference on spectroscopic ellipsometry (ICSE-7) CY - Berlin, Germany DA - 06.06.2016 KW - Spectroscopic Ellipsometry KW - Electron Microscopy KW - Multi-method Metrology KW - Porous Materials KW - Thin Films KW - Titanium Dioxide PY - 2016 AN - OPUS4-37202 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 - CONF A1 - Ferraioli, M. A1 - Abruzzese, D. A1 - Miccoli, Lorenzo A1 - Mandara, A. ED - Galea, P. ED - Borg, R. P. ED - Farrugia, D. ED - Agius, M. R. ED - D'Amico, S. ED - Torpiano, A. ED - Bonello, M. T1 - Dynamic identification and seismic safety of two masonry towers N2 - The recent experience of Italian seismic events provided wide observational information about typical behaviour, damage patterns and intrinsic vulnerability of monumental buildings. Evidence indicates that historical constructions are by far the most vulnerable from the seismic point of view. As a consequence, they demand for the definition of urgent strategies for the protection of cultural heritage from seismic hazard. The main goal of an in-depth knowledge of the structure should help to avoid inadequate, unsuitable or dangerous rehabilitation operations, as well as to select non-invasive and reversible techniques for the best exploitation of material and technology features. The definition of reliable models and methods for seismic risk assessment of historical constructions is today a very important topic. Typical problems of masonry structures concern aspects like inherent structural lacks, material degradation, geotechnical problems, buckling behaviour of slender elements and dynamic loading vulnerability. Modelling the mechanical behaviour of masonry may play an important role, due to both inherent material complexity and great scatter in mechanical properties. Effective procedures for the identification of the structural parameters from static and dynamic testing are thus required. In particular, dynamic measurements may be very useful for the identification of mechanical properties and soil restraints and, consequently, for the calibration of advanced numerical finite element models. The paper addresses two case studies of structural monitoring and seismic assessment of medieval masonry towers in Italy: the bell tower of Aversa and the bell tower of Capua. These monuments, placed in the Campania region, were monitored by means of full-scale environmental vibration testing. Measured responses are then used for modal identification with a typical finite element model updating technique based on vibration test results. Parameters optimization is carried out on the basis of a criterion which minimises a weighted error on modal properties. A satisfactory improvement in the determination of modal parameters is thus obtained, resulting in a close agreement between the modal properties observed in dynamic tests and those calculated from numerical model. Seismic assessment is finally performed based on nonlinear static analysis of the tower under multimodal distributions of lateral loads. Results from nonlinear analysis indicate the potential collapse mechanisms and evidence dangerous structural weakness which may play a role in the seismic vulnerability of the towers. T2 - Georisk in the Mediterrean and their mitigation CY - Valletta, Malta DA - 20.07.2015 KW - masonry towers KW - ambient vibration tests KW - dynamic characterisation KW - seismic assessment PY - 2016 SN - 978-88-98161-20-1 SP - 250 EP - 251 PB - Mistral Service AN - OPUS4-37204 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -