TY - CONF A1 - Kositz, M. A1 - Hünger, K.-J. A1 - Weise, Frank T1 - Regression analysis of ASR expansions and silica dissolution in the presence of NaCl N2 - The durability of concrete structures due to alkali-silica-reaction (ASR) is usually been assessed by ASR concrete prism tests (CPT). Therefore, the expansion of concrete specimens indicates an alkalisensitivity. In Germany these tests are performed at 40°C or accelerated 60°C. Nevertheless, ASR prism tests are expensive, power and time-consuming. For these reasons, an alternative chemical test (“mod. BTU-test”) was developed in the past. The “mod. BTU-test” was correlated with German standard CPT. In this test, the solubility of silica and alumina in the liquid phase is measured by ICP-OES. For special requirements in concrete road construction, stricter test procedures are necessary. The specimens are repeatedly subjected to cyclic alternating storage in NaCl. On the one hand, the presence of NaCl increases the ASR expansion, on the other hand NaCl also changes the dissolution behaviour of silica and alumina. For now is not possible to correlate the solubilities of “mod. BTU-test” and ASR expansions influenced by NaCl. Therefore, four aggregates with different ASR sensitivities were chosen and ASR concrete prism tests (in addition with NaCl) have been performed. According to the “mod. BTU-test” the solubilities of silica and alumina in presence of different NaCl concentrations were measured. This paper is about the regression analysis of silica and alumina dissolution and ASR expansion tests in presence of NaCl. The regression analysis shows the influence of a quasi-continuous and an interrupted cyclic alternating storage. Additionally the effects of temperature and NaCl concentration are investigated. In the end, a suitable NaCl concentration of the “mod. BTU-test” for dissolution experiments is recommended. The “mod. BTU-Test” with NaCl might be a serious and reliable test method for ASR classification for concrete road construction. T2 - 16th International Conference on Alkali-Aggregate Reaction in Concrete CY - Lisboa, Portugal DA - 31.05.2022 KW - Alkali silica reaction KW - Alkaline solution KW - Alumina & silica dissolution KW - NaCl KW - Regression analysis PY - 2021 SN - 978-972-49-2315-4 VL - 1 SP - 711 EP - 723 AN - OPUS4-54552 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schilder, Constanze A1 - Kohlhoff, Harald A1 - Hofmann, Detlef A1 - Basedau, Frank A1 - Habel, Wolfgang A1 - Baeßler, Matthias A1 - Niederleithinger, Ernst A1 - Georgi, Steven A1 - Herten, M. ED - Jaroszewicz, L.R. T1 - Static and dynamic pile testing of reinforced concrete piles with structure integrated fibre optic strain sensors N2 - Static and dynamic pile tests are carried out to determine the load bearing capacity and the quality of reinforced concrete piles. As part of a round robin test to evaluate dynamic load tests, structure integrated fibre optic strain sensors were used to receive more detailed information about the strains along the pile length compared to conventional measurements at the pile head. This paper shows the instrumentation of the pile with extrinsic Fabry-Perot interferometers sensors and fibre Bragg gratings sensors together with the results of the conducted static load test as well as the dynamic load Tests and pile integrity tests. T2 - EWOFS 2013 - 5th European workshop on optical fibre sensors CY - Kraków, Poland DA - 19.05.2013 KW - Static load test KW - Dynamic load test KW - Pile integrity test KW - Extrinsic Fabry-Perot interferometer KW - Fibre Bragg grating KW - Structure integrated sensor KW - Fibre optic strain sensor PY - 2013 SN - 978-0-81949-634-8 DO - https://doi.org/10.1117/12.2026813 SN - 0277-786X N1 - Serientitel: Proceedings of SPIE – Series title: Proceedings of SPIE VL - 8794 IS - Paper 8794 - 181 SP - 700 EP - 703 AN - OPUS4-28854 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Niederleithinger, Ernst A1 - Gardner, S. A1 - Kind, Thomas A1 - Kaiser, R. A1 - Grunwald, Marcel A1 - Yang, G. A1 - Redmer, Bernhard A1 - Waske, Anja A1 - Mielentz, Frank A1 - Effner, Ute A1 - Köpp, Christian A1 - Clarkson, A. A1 - Thompson, F. A1 - Ryan, M. A1 - Mahon, D. T1 - Muon Tomography of the Interior of a Reinforced Concrete Block: First Experimental Proof of Concept N2 - Quality assurance and condition assessment of concrete structures is an important topic world-wide due to the aging infrastructure and increasing traffic demands. Common topics include, but are not limited to, localisation of rebar or tendon ducts, geometrical irregularities, cracks, voids, honeycombing or other flaws. Non-destructive techniques such as ultrasound or radar have found regular, successful practical application but sometimes suffer from limited resolution and accuracy, imaging artefacts or restrictions in detecting certain features. Until the 1980s X-ray transmission was used in case of special demands and showed a much better resolution than other NDT techniques. However, due to safety concerns and cost issues, this method is almost never used anymore. Muon tomography has received much attention recently. Novel detectors for cosmic muons and tomographic imaging algorithms have opened up new fields of application, such as the investigation of freight containers. Muon imaging also has the potential to fill some of the gaps currently existing in concrete NDT. As a first step towards practical use and as a proof of concept we used an existing system to image the interior of a reference reinforced 600 kg concrete block. Even with a yet not optimized setup for this kind of investigation, the muon imaging results are at least of similar quality compared to ultrasonic and radar imaging, potentially even better. The data acquisition takes more time and signals contain more noise, but the images allowed to detect the same important features that are visible in conventional high energy X-ray tomography. In our experiment, we have shown that muon imaging has potential for concrete inspection. The next steps include the development of mobile detectors and optimising acquisition and imaging parameters. KW - Concrete KW - Muon KW - Radar KW - Ultrasound KW - X-ray PY - 2021 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-529974 DO - https://doi.org/10.1007/s10921-021-00797-3 VL - 40 IS - 3 SP - 1 EP - 14 PB - Springer Nature AN - OPUS4-52997 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Weise, Frank A1 - Hüsken, Götz A1 - Niedack-Nad, Marianne A1 - Wieland, M. T1 - AL Sp-Beton - Präzision des Prüfverfahrens N2 - Für die rechnerische Dimensionierung der Betondecken im Oberbau von Verkehrsflächen für den Neubau sowie die Erneuerung nach RDO-Beton 09 ist die statische Spaltzugfestigkeit an der unteren bzw. unteren und oberen Scheibe des Betonzylinders bzw. Bohrkerns entsprechend der Vorgaben der AL Sp-Beton zu bestimmen. Aufgrund der unzureichenden Kenntnis der Präzision dieses Prüfverfahrens wurden mit einem breit aufgestellten Ringversuch die statistischen Kennwerte an Labor- und Bestandsbetonen unter Vergleich- und Wiederholbedingungen auf der Grundlage des FGSV-Merkblatts über die statistische Auswertung von Prüfergebnissen ermittelt. Für eine möglichst gute statistische Absicherung nahmen an dem Ringversuch dreizehn erfahrene Prüfstellen teil. Zur Abdeckung des vielschichtigen Einsatzes des Prüfverfahrens erfolgte der Ringversuch an acht Prüflosen. Dabei berücksichtigen einerseits die Prüflose 1 und 2 mit den im Transportbetonwerk hergestellten Betonzylindern die Erst-/Eignungsprüfung und das darauf aufbauende Prüflos 3 mit Bohrkernen aus einer im Feldversuch hergestellten Fahrbahnplatte mit gleicher Betonrezeptur die Übereinstimmungskontrolle bei Neubaumaßnahmen. Andererseits findet der Einsatz des Prüfverfahrens bei der Restsubstanzbewertung von Betonfahrbahnplatten bei den Prüflosen 4 bis 7 mit den Bohrkernen aus vier in Waschbetonbauweise ausgeführten Fahrbahnplatten Berücksichtigung. Das zusätzlich aufgenommene Prüflos 8 mit einem Labormörtel dient der Herausarbeitung des Materialeinflusses auf die Präzision der Spaltzugfestigkeitsprüfung. Zusammenfassend kann festgestellt werden, dass die Präzision der in der AL SP-Beton beschriebenen Spaltzugfestigkeitsprüfung mit einem Variationskoeffizienten von weniger als 10 % unter Wiederhol- und Vergleichsbedingungen hinreichend genau ist. Der geringe Unterschied zwischen den Variationskoeffizienten unter Wiederhol- und Vergleichsbedingungen lässt zusätzlich den Schluss zu, dass der Einfluss des unterschiedlichen Personals und der verschiedenartigen Prüftechniken bei den einzelnen Prüfstellen relativ gering ist. Die im Rahmen des Ringversuchs gewonnenen Erkenntnisse haben bereits partiell Eingang in die Normung gefunden. KW - Betonfahrbahndecken KW - Spaltzugfestigkeit KW - Ringversuch KW - Verfahrenspräzision PY - 2014 SN - 0039-2162 VL - 66 IS - 10 SP - 790 EP - 798 PB - Kirschbaum-Verl. CY - Bonn-Bad Godesberg AN - OPUS4-32066 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Weise, Frank A1 - Redmer, Bernhard A1 - Müller, Urs A1 - Hübner, M. T1 - Condition assessment of ancient architectural monuments in the Pergamon museum - The combined application of NDT-methods for structural investigations KW - ZFP PY - 2008 SN - 0344-5089 VL - 21 SP - 23 EP - 32 PB - Staatliche Museen CY - Berlin AN - OPUS4-18585 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Weise, Frank A1 - Redmer, Bernhard A1 - Hübner, M. ED - Forde, M. T1 - Combination of non-destructive testing methods for structural investigations of ancient architectural monuments T2 - 11th International Conference and Exhibiton "Structural Faults and Repair - 2006" CY - Edinburgh, Scotland, UK DA - 2006-06-13 KW - Ancient Monuments KW - Reinforcement Detection KW - Radar KW - Videoscopy KW - Stereoradiography PY - 2006 SN - 0-947644-59-8 SP - 1 EP - 9 PB - Engineering Technics Pr., CY - Edingburgh AN - OPUS4-14401 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Rai, Alena A1 - Stelzner, Ludwig A1 - Weise, Frank A1 - Wieland, M. T1 - 3D-Analyse von Betonfahrbahnoberflächen mit Grinding- und Groovingtextur mittels Streifenlichtprojektion N2 - Die Oberflächentexturierung der Betonfahrbahndecken mittels Grinding- und Grooving steht seit einigen Jahren im Mittelpunkt der Forschung und Entwicklung des Betonstraßenbaus in Deutschland. In den vergangenen Jahren wurden die vorteilhaften Oberflächenperformances derartiger Texturen wie z.B. Griffigkeit, Ebenheit, Lärmminderung in zahlreichen Forschungsprojekten umfassend untersucht und daraus die Technologie „Texturgrinding“ entwickelt. Im Kontext des gegenwärtig verfolgten ganzheitlichen performanceorientierten Ansatzes liegt der Fokus nun verstärkt auf der Analyse und Charakterisierung der Oberflächentopografie von Grinding- bzw. Groovingtexturen. Insbesondere gilt ein Hauptaugenmerk hierbei der zeitlichen Entwicklung der Oberflächentexturen in Abhängigkeit von äußeren Einwirkungen durch Klima und Verkehr. Dieser Beitrag zeigt, dass durch den Einsatz eines auf Streifenlichtprojektion basierenden Messsystems, eine hochaufgelöste dreidimensionale Erfassung der Oberflächentopografie verschiedenartiger Grinding- und Groovingtexturen möglich ist. Darauf aufbauend wurden messtechnische Voraussetzungen zur Gewährleistung reproduzierbarer Messungen geschaffen, die eine Dokumentation der zeitlichen Texturveränderungen infolge klimatischer Beanspruchung ermöglichen. Anschließend wurden Auswerteroutinen zur quantitativen und statistischen Charakterisierung der Oberflächentextur entwickelt und angewandt, um exemplarisch die Veränderungen der Oberflächentopografie infolge klimatischer Beanspruchung quantitativ abzubilden. KW - Betonfahrbahndecken KW - Grinding KW - Grooving KW - Oberflächentexturierung KW - Streifenlichtprojektion PY - 2020 DO - https://doi.org/10.1002/best.202000015 SP - 1 EP - 9 PB - Wilhelm Ernst & Sohn Verlag für Architektur und technische Wissenschaften GmbH & Co. KG CY - Berlin AN - OPUS4-51012 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Weise, Frank A1 - Maier, Bärbel A1 - Alonso, M. T. A1 - Müller, C. T1 - Analyse des Verhaltens von Gesteinskörnungen im Beton bei Frosttauwechselbeanspruchung N2 - Die hier vorgestellten Untersuchungen erfolgten im Rahmen eines von der AiF geförderten Verbundforschungsvorhabens „Frost- und Frost-Tausalz-Widerstand von Beton unter besonderer Berücksichtigung der verwendeten Gesteinskörnung“. Sie waren insbesondere Bestandteil des gemeinsam vom VDZ und der BAM bearbeiteten Teilprojektes „Prüfung der Gesteinskörnung im Beton“, Die Basis für die Auswahl der zu untersuchenden Gesteinskörnungen bildeten die Teilprojekte der Bauhaus Universität Weimar zur Petrographie sowie der TU München zum Frost- und Frost-Tausalz-Widerstand der Gesteinskörnung, Ausgangspunkt des Vorhabens war die Feststellung, dass die Beurteilung des Frost und Frost-Tausalz-Widerstandes von Gesteinskörnungen mit Laborprüfverfahren an der Gesteinskörnung und im Beton, je nach verwendetem Prüfverfahren und Grenzwerten, zu einer unterschiedlichen Klassifizierung führen kann, Bisher kann bei keiner Form der Prüfung des Frost- bzw. Frost-Tausalz-Widerstandes an der Gesteinskörnung ausgeschlossen werden, dass die Gesteinskörnung in dieser Prüfung ein anderes Verhalten aufweist, als später im Bauwerk im einbetonierten Zustand. In diesem Beitrag wird ausschließlich das Frostverhalten ausgewählter Gesteinskörnungen in XF3-Betonen unter Verwendung eines Portlandzements CEM I 32,5 R dargestellt. Es werden betontechnologische Maßnahmen zur Verbesserung des Frostverhaltens eines Betons, der mit einer nicht frostbeständigen Gesteinskörnung hergestellt wurde, aufgezeigt. Zur Verfolgung der inneren frostinduzierten Gefügeveränderung kamen neben konventionellen Prüftechniken auch erstmals röntgentomografische Untersuchungen zum Einsatz. T2 - 18. Ibausil - Internationale Baustofftagung CY - Weimar, Germany DA - 12.09.2012 PY - 2012 SN - 978-3-00-034075-8 VL - 2 IS - 3.07 SP - 2-0453 EP - 2-0467 AN - OPUS4-26546 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Hurtado-Hurtado, G. A1 - Morales-Velazquez, L. A1 - Valtierra-Rodríguez, M. A1 - Otremba, Frank A1 - Jáuregui-Correa, J. C. T1 - Frequency Analysis of the Railway Track under Loads Caused by the Hunting Phenomenon N2 - Hunting is a potentially dangerous phenomenon related to the lateral oscillation of the wheels that impacts the rails and causes the wear of the infrastructure’s components. Therefore, the analysis and timely detection of hunting can lead to the application of corrective maintenance tasks, reducing damages, and costs and even derailments as a result. In this work, the vibration response of a finite element model of a rail with hunting-induced loads by a single wheel is analyzed in three directions: longitudinal, lateral, and vertical. The contact patch forces are calculated by means of Simpack® using the Kalker linear theory and the contact Hertz theory. The system is solved by using the Newmark-_ approach. The results of the deflection and vibration analysis, following the proposed methodology, show how the different characteristics of the loads impact the rail. KW - Continuous wavelet transform KW - Empirical mode decomposition KW - Finite element method KW - Frequency analysis KW - Hunting phenomenon KW - Mechanical modelling KW - Rail vibrations PY - 2022 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-551517 UR - https://www.mdpi.com/2227-7390/10/13/2286/htm# DO - https://doi.org/10.3390/math10132286 VL - 10 IS - 13 SP - 1 EP - 17 PB - MDPI AN - OPUS4-55151 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Romero-Navarrete, José A. A1 - Otremba, Frank A1 - Sklorz, Christian A1 - Martínez Madrid, M. T1 - Quasistatic rollover threshold of atmospheric road tankers N2 - Several geometrical analytical tools can be used for assessing the potential benefits of any alternative tank shape. The quasistatic evaluation of the cargo-vehicle behavior represents a fast way to objectively determine the roll stability benefits of any potentially new tank shape. In this paper, the geometrical, quasistatic rollover performance of a convex bottom tank shape is compared with that of standard tank shapes, finding that in spite of the lower position of the cargo´s center of gravity in such a tank shape for the un-perturbed condition, it has the same performance as the elliptical tank shape when subjected to Steady lateral acceleration. That as a result of the large cargo´s lateral displacement. Consequently, the combination of a lower center of gravity for the cargo when it is not perturbed, and a Minimum lateral shift due to lateral accelerations inputs, define the conditions for an ideal tank shape. T2 - CONIIN 2020 CY - Online meeting DA - 28.09.2020 KW - Tank shape KW - Road tankers KW - Center of gravity shifting KW - Quasistatic KW - Convex bottom KW - Geometrical analysis PY - 2020 SP - 1 EP - 6 AN - OPUS4-51388 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Bradley, Ian A1 - Scarponi, G. E. A1 - Otremba, Frank A1 - Birk, A. M. T1 - An overview of test standards and regulations relevant to the fire testing of pressure vessels N2 - Fire exposure of storage and transportation vessels of hazardous materials (including pressure liquefied gases) can result in BLEVEs and other high-consequence incidents with large societal and economic impacts. To reduce risk most countries have numerous regulations, codes of practice and guidance notes covering the design, operation and maintenance of vessels and thermal protection systems. Yet despite such regulations there remains no internationally accepted fire test procedure for pressure vessel and accompanying thermal protection systems that is capable of meeting a range of regulatory requirements. This paper considers some of the regulations in place in the western world and considers the origin of these based on large and medium-scale testing conducted to date. It examines conditions found in these tests to propose a set of recommendations on which to base a standard method of test. These recommendations are proposed as being representative of a credible large pool fire scenario that may occur. KW - LPG KW - Pressure vessel KW - Test KW - BLEVE KW - Fire PY - 2021 DO - https://doi.org/10.1016/j.psep.2020.07.047 SN - 0957-5820 VL - 145 SP - 150 EP - 156 PB - Elsevier CY - Amsterdam AN - OPUS4-51139 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Adamus, A. A1 - Ali, I. A1 - Vasileiadis, V. A1 - Al-Hileh, L. A1 - Lisec, Jan A1 - Frank, M. A1 - Seitz, G. A1 - Engel, N. T1 - Vincetoxicum arnottianum modulates motility features and metastatic marker expression in pediatric rhabdomyosarcoma by stabilizing the actin cytoskeleton N2 - Background: Prevention of metastatic invasion is one of the main challenges in the treatment of alveolar rhabdomyosarcoma. Still the therapeutic options are limited. Therefore, an anti-tumor screening was initiated focusing on the anti-metastatic and anti-invasion properties of selected medicinal plant extracts and phytoestrogens, already known to be effective in the prevention and treatment of different cancer entities. Methods: Treatment effects were first evaluated by cell viability, migration, invasion, and colony forming assays on the alveolar rhabdomyosarcoma cell line RH-30 in comparison with healthy primary cells. Results: Initial anti-tumor screenings of all substances analyzed in this study, identified the plant extract of Vincetoxicum arnottianum (VSM) as the most promising candidate, harboring the highest anti-metastatic potential. Those significant anti-motility properties were proven by a reduced ability for migration (60%), invasion (99%) and colony formation (61%) under 48 h exposure to 25 μg/ml VSM. The restricted motility features were due to an induction of the stabilization of the cytoskeleton – actin fibers were 2.5-fold longer and were spanning the entire cell. Decreased proliferation (PCNA, AMT, GCSH) and altered metastasis (e. g. SGPL1, CXCR4, stathmin) marker expression on transcript and protein level confirmed the significant lowered tumorigenicity under VSM treatment. Finally, significant alterations in the cell metabolism were detected for 25 metabolites, with levels of uracil, N-acetyl serine and propanoyl phosphate harboring the greatest alterations. Compared to the conventional therapy with cisplatin, VSM treated cells demonstrated a similar metabolic shutdown of the primary cell metabolism. Primary control cells were not affected by the VSM treatment. Conclusions: This study revealed the VSM root extract as a potential, new migrastatic drug candidate for the putative treatment of pediatric alveolar rhabdomyosarcoma with actin filament stabilizing properties and accompanied by a marginal effect on the vitality of primary cells. KW - Mass Spectroscopy KW - Metabolomics KW - Cancer PY - 2021 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-533530 DO - https://doi.org/10.1186/s12906-021-03299-x VL - 21 IS - 1 PB - Springer Nature AN - OPUS4-53353 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Adamus, A. A1 - Peer, K. A1 - Ali, I. A1 - Lisec, Jan A1 - Falodun, A. A1 - Frank, M. A1 - Seitz, G. A1 - Engel, N. T1 - Berberis orthobotrys – A promising herbal anti-tumorigenic candidate for the treatment of pediatric alveolar rhabdomyosarcoma N2 - Ethnopharmacological relevance: Berberis orthobotrys (BORM) is a medical plant with a long history in traditional usage for the treatment of wounds, cancer, gastrointestinal malady and several other diseases. Our previous studies identified the endemic Pakistani plant Berberis orthobotrys Bien. ex Aitch. as promising source for the treatment of breast cancer and osteosarcoma. Aim of the study: The present study was aimed to evaluate the anti-cancer properties of 26 plant derived extracts and compounds including the methanolic root extract of Berberis orthobotrys (BORM) on pediatric alveolar rhabdomyosarcoma (RMA), which is known to develop drug resistance, metastatic invasion and potential Tumor progression. Materials and methods: The main anti-tumor activity of BORM was verified by focusing on morphological, cell structural and metabolic alterations via metabolic profiling, cell viability measurements, flow cytometry, western blotting and diverse microscopy-based methods using the human RMA cell line Rh30. Results: Exposure of 25 μg/ml BORM exerts an influence on the cell stability, the degradation of oncosomes as well as the shutdown of the metabolic activity of RMA cells, primarily by downregulation of the energy metabolism. Therefore glycyl-aspartic acid and N-acetyl serine decreased moderately, and uracil increased intracellularly. On healthy, non-transformed muscle cells BORM revealed very low metabolic alterations and nearly no cytotoxic impact. Furthermore, BORM is also capable to reduce Rh30 cell migration (~50%) and proliferation (induced G2/M cycle arrest) as well as to initiate apoptosis confirmed by reduced Bcl-2, Bax and PCNA expression and induced PARP-1 cleavage. Conclusions: The study provides the first evidence, that BORM treatment is effective against RMA cells with low side effects on healthy cells. KW - Mass-Spectrometry PY - 2018 DO - https://doi.org/10.1016/j.jep.2018.10.002 SN - 0378-8741 VL - 229 SP - 262 EP - 271 PB - Elsevier B.V. AN - OPUS4-46458 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Gant, Simon A1 - Chang, Joseph A1 - Hetherington, Rory A1 - Hanna, Steven A1 - Tickle, Gemma A1 - Spicer, Tom A1 - McMasters, Sun A1 - Fox, Shannon A1 - Meris, Ron A1 - Bradley, Scott A1 - Miner, Sean A1 - King, Matthew A1 - Simpson, Steven A1 - Mazzola, Thomas A1 - McGillivray, Alison A1 - Tucker, Harvey A1 - Björnham, Oscar A1 - Carissimo, Bertrand A1 - Fabbri, Luciano A1 - Wood, Maureen A1 - Habib, Abdel Karim A1 - Harper, Mike A1 - Hart, Frank A1 - Vik, Thomas A1 - Helgeland, Anders A1 - Howard, Joel A1 - Mauri, Lorenzo A1 - Mackie, Shona A1 - Mack, Andreas A1 - Lacome, Jean-Marc A1 - Puttick, Stephen A1 - Ibrahim, Adeel A1 - Miller, Derek A1 - Dharmavaram, Seshu A1 - Shen, Amy A1 - Cunningham, Alyssa A1 - Beverly, Desiree A1 - O’Neal, Daniel M. A1 - Verdier, Laurent A1 - Burkhart, Stéphane A1 - Dixon, Chris A1 - Nilsen, Sandra A1 - Bradley, Robert A1 - Skarsvåg, Hans L. A1 - Fyhn, Eirik H. A1 - Aasen, Ailo T1 - Pressure-Liquefied Ammonia Jet Dispersion: Multi-Model Intercomparison Using Desert Tortoise and FLADIS Field Data N2 - This paper presents the findings of an international model inter-comparison exercise that was undertaken in the period 2021-2024 to assess the performance of atmospheric dispersion models for simulating releases of pressure-liquefied ammonia. The exercise used data from ammonia field trials dating from the 1980s and 1990s: the Desert Tortoise and the FLADIS trials. Concentration data from two arcs of sensors in the Desert Tortoise trials and three arcs of sensors in the FLADIS trials were used. Twenty-one independent modelling teams from North America and Europe participated in the exercise and provided in total twenty-seven sets of results from a range of different models, including empirically-based nomograms, integral, Gaussian puff, Lagrangian particle, and Computational Fluid Dynamics (CFD) models. The work is novel in presenting the results from such a large cohort of models, examining specifically the dispersion behaviour of ammonia. This is particularly relevant at the current time, given the growing international interest in using ammonia as a clean energy vector and shipping fuel. The study found that the agreement between model predictions and measurements (as determined by performance measures such as geometric mean bias and geometric variance) varied between different models. At any downwind distance, the range in predicted plume arc-max concentrations spanned a range of up to one or two orders of magnitude about the measurements. Several modelling teams used the same models and, in most cases, their predictions differed. Given appropriate inputs, most models generally predicted concentrations that agreed with the data within commonly-used model acceptance criteria. There was no single class of model that provided superior predictions to others; predictions from several empirically-based nomograms, integral, Gaussian puff, Lagrangian particle, and CFD models were all in close agreement with the data (as defined by the model acceptance criteria). The findings of the exercise are being used to help plan a programme of future ammonia experiments in the USA, called the Jack Rabbit III trials. The results are also useful for assessing the performance of models that may be applied to assess risks at ammonia facilities, and for emergency planning and response. KW - Ammonia KW - Atmospheric dispersion KW - Validation KW - Jack rabbit PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-646069 DO - https://doi.org/10.1016/j.aeaoa.2025.100389 SN - 2590-1621 VL - 28 SP - 1 EP - 76 PB - Elsevier Ltd. AN - OPUS4-64606 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Ferrero, Fabio A1 - Kluge, Martin A1 - Schmidtchen, Ulrich A1 - Pahl, Robert A1 - Noack, Jennifer A1 - Kolvitz, Kristian A1 - Runge, Thomas A1 - Holtappels, Kai A1 - Hensel, Christina A1 - Bönig, Jürgen A1 - Schulze, Uwe A1 - Askar, Enis A1 - Frank, M. A1 - Thornton, D. T1 - Experimentelle und numerische Untersuchungen des Verhaltens von Acetylenflaschen im Feuer T2 - 12. Kolloquium zu Fragen der chemischen und physikalischen Sicherheitstechnik CY - Berlin, Deutschland DA - 2010-06-15 KW - Acetylendruckgasbehälter KW - Unterfeuerung KW - Aufheizverhalten KW - CFD-Modellierung PY - 2010 SN - 978-3-9813550-1-7 SN - 0938-5533 N1 - Geburtsname von Kluge, Martin: Beckmann-Kluge, M. - Birth name of Kluge, Martin: Beckmann-Kluge, M. SP - 70 EP - 72 PB - BAM Bundesanstalt für Materialforschung und -prüfung CY - Berlin AN - OPUS4-21488 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wille, Frank A1 - Ballheimer, Viktor A1 - Apel, Andreas A1 - Kuschke, Christian A1 - Moutarde, M. A1 - Desnoyers, B. A1 - Kalinina, E. A1 - Ammerman, D. T1 - ISO-Standard and IAEA guidance material for package load attachment Points - Current approaches and developments N2 - For transport package design and operation according to the IAEA regulations, the package shall be securely stowed and its retention system shall be capable to withstand load conditions of routine transport. The supporting IAEA Advisory Material SSG-26 provides information how to do that. Up to now package designers in different countries use other load factors for the design of attachment points than those specified in the IAEA guidance material. In particular the acceleration values vary between different countries and lead to difficulties during the validation of foreign approval certificates. Therefore the IAEA started a discussion process to review the existing guidance text. An international working group was constituted in 2013. Representatives came from different stakeholders, e.g. transport operators, competent authorities and modal organizations. The discussions concluded especially on the transport conditions which has to be considered for stowage design, including on the one hand the relevance of the load factors used for strength and fatigue analysis and on the other hand the criteria which have to be considered for the attachment points. The proposed acceleration values will be compared to those measured during recent multi-modal testing by Sandia National Laboratories that measured the acceleration levels experienced by a spent fuel flask during heavy-haul truck, sea, and rail transport. The ISO standard 10276 is dealing with the load attachment systems of packages as well. This standard considers the trunnion design, manufacturing and operational aspects. The regular standard revision phase started in 2017. An expert group discussed new state-of-the-art technology, different analysis approaches for strength and fatigue analysis and proposed revised text for the ISO standard for international discussion. The finite-element analysis approach incl. appropriate acceptance criteria are described and referenced. The paper describes relevant tie-down aspects, gives background argumentation relevant to analysis approaches, and tries to support harmonized application of the revised IAEA guidance material and the future revised ISO standard. T2 - 19th International Symposium on the Packaging and Transportation of Radioactive Materials PATRAM 2019 CY - New Orleans, LA, USA DA - 04.08.2019 KW - Load attachment KW - Stowage KW - Trunnion KW - Bolt design KW - Retention KW - Acceleration KW - Transport KW - Load cycles PY - 2019 SP - Paper 1130, 1 EP - 10 AN - OPUS4-49095 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wille, Frank A1 - Debruyne, M. A1 - Eckert, B. A1 - Gauthier, F. A1 - Ben Ouaghrem, K. A1 - Le Bars, I. A1 - Jouve, A.-C. A1 - Cordier, N. T1 - Assessment of safety demonstrations relative to packages containing UF6 N2 - The safety demonstrations realized by applicants in the case of approval request for the package designs containing enriched UF6 have to take into account some specific technical issues. Concerning the shipment of enriched UF6, the package designs consist in general of a filled 30B cylinder surrounded by an overpack. The description of the content, considering the UF6 origin, i.e. natural or reprocessed, shall be clearly justified especially when the UF6 isotopic composition exceeds the limits specified in ASTM standards. Concerning the containment of the UF6, the applicant shall demonstrate in all conditions of transport the leak-tightness of the valve and plug of the cylinders filled with enriched UF6. In this regard, when mechanical justifications are based on numerical calculations, the absence of contact between these components of the cylinder and the internal surfaces of the overpack after the regulatory drop tests shall be shown to respect the IAEA regulations. Furthermore, the representativeness of the ballast used to simulate the behaviour of the UF6 loaded within the cylinder shall be justified if drop tests are performed. The representativeness of the ballast should also be justified for numerical calculations. In addition, the applicant shall demonstrate that the melting temperature of the valve and the plug, including the tinned joint, will not be exceeded during the regulatory fire test. Finally, specific provisions relative to the use of plugs and the maintenance of cylinders should be included in the safety analysis report. T2 - 19th International Symposium on the Packaging and Transportation of Radioactive Materials PATRAM 2019 CY - New Orleans, LA, USA DA - 04.08.2019 KW - Valve KW - Fire test KW - Content simulation KW - UF6 KW - Intumescent material PY - 2019 SP - Paper 1208, 1 EP - 8 AN - OPUS4-49094 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Schreiber, Frank A1 - Ackermann, M. T1 - Environmental drivers of metabolic heterogeneity in clonal microbial populations N2 - Microorganisms perform multiple metabolic functions that shape the global cycling of elements, health and disease of their host organisms, and biotechnological processes. The rates, at which different metabolic activities are performed by individual cells, can vary between genetically identical cells within clonal populations. While the molecular mechanisms that result in such metabolic heterogeneity have attracted considerable interest, the environmental conditions that shape heterogeneity and its consequences have received attention only in recent years. Here, we review the environmental drivers that lead to metabolic heterogeneity with a focus on nutrient limitation, temporal fluctuations and spatial structure, and the functional consequences of such heterogeneity. We highlight studies using single-cell methods that allow direct investigation of metabolic heterogeneity and discuss the relevance of metabolic heterogeneity in complex microbial communities. KW - Phenotypic variation KW - NanoSIMS KW - Diversity KW - Metabolism PY - 2019 UR - https://www.sciencedirect.com/science/article/abs/pii/S095816691930134X?via%3Dihub DO - https://doi.org/10.1016/j.copbio.2019.11.018 VL - 62 SP - 202 EP - 211 PB - Elsevier Ltd. AN - OPUS4-50194 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Helmerich, Rosemarie A1 - Mielentz, Frank A1 - Milmann, Boris A1 - Adam, Louisa A1 - Villalobos, S. A1 - Guimaraes, M. A1 - Wiggenhauser, Herbert T1 - Detection of cracks perpendicular to the surface using acoustic methods N2 - Cracks perpendicular to the surface may be initial indicators for a deterioration process of concrete structures. Moisture penetrates inside the structure and transports adverse chemicals. The paper presents an investigation about the reliability of available commercial non-destructive evaluation techniques to reliably estimate the depth of surface-breaking cracks in reinforced concrete structures. Aim of the study was the investigation of surface-braking cracks under laboratory conditions. Commercial acoustic devices as impact echo equipment, single ultrasonic transducers and arrays were applied even if they have not been developed for this purpose. The commercial software and descriptions for application was followed strictly to compare the function, precision and repeatability of the measurements. Both, perpendicular notches and cracks have been considered. The study was completed with a discussion about reference specimens. The study was the basis for formulation of gaps in research. The Electric Power Research Institute (EPRI) has initiated and funded a Project. T2 - NDT-CE 2015 - International symposium non-destructive testing in civil engineering CY - Berlin, Germany DA - 15.09.2015 KW - Acoustic test KW - Commercial acoustic devices KW - Ultrasonic test KW - Crack depth KW - Concrete specimens PY - 2015 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-345729 UR - https://www.ndt.net/?id=18412 SN - 1435-4934 VL - 20 IS - 11 SP - 1 EP - 9 PB - NDT.net CY - Kirchwald AN - OPUS4-34572 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Procop, Mathias A1 - Radtke, Martin A1 - Krumrey, M. A1 - Hasche, K. A1 - Schädlich, S. A1 - Frank, W. T1 - Electron probe microanalysis (EPMA) measurement of thin-film thickness in the nanometre range N2 - The thickness of thin films of platinum and nickel on fused silica and silicon substrates has been determined by EPMA using the commercial software STRATAGEM for calculation of film thickness. Film thickness ranged in the order 10 nm. An attempt was made to estimate the confidence range of the method by comparison with results from other methods of analysis. The data show that in addition to the uncertainty of the spectral intensity measurement and the complicated fitting routine, systematic deviation caused by the underlying model should be added. The scattering in the results from other methods does not enable specification of a range of uncertainty, but deviations from the real thickness are estimated to be less than 20%. KW - Electron probe microanalysis KW - EPMA KW - Thin films KW - Thickness measurement KW - X-rays PY - 2002 DO - https://doi.org/10.1007/s00216-002-1514-5 SN - 1618-2642 SN - 1618-2650 VL - 374 SP - 631 EP - 634 PB - Springer CY - Berlin AN - OPUS4-7090 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Varadarajan, A. A1 - Allan, R. A1 - Valentin, J. A1 - Castañeda Ocampo, O. A1 - Somerville, V. A1 - Buhmann, M. A1 - West, J. A1 - Skipp, Paul A1 - van der Mei, H. A1 - Ren, Q. A1 - Schreiber, Frank A1 - Webb, J. A1 - Pietsch, Franziska A1 - Ahrens, C. T1 - An integrated model system to gain mechanistic insights into biofilm-associated antimicrobial resistance in Pseudomonas aeruginosa MPAO1 N2 - Pseudomonas aeruginosa MPAO1 is the parental strain of the widely utilized transposon mutant collection for this important clinical pathogen. Here, we validate a model system to identify genes involved in biofilm growth and biofilm-associated antibiotic resistance. Our model employs a genomics-driven workflow to assemble the complete MPAO1 genome, identify unique and conserved genes by comparative genomics with the PAO1 reference strain and genes missed within existing assemblies by proteogenomics. Among over 200 unique MPAO1 genes, we identified six general essential genes that were overlooked when mapping public Tn-seq data sets against PAO1, including an antitoxin. Genomic data were integrated with phenotypic data from an experimental workflow using a user-friendly, soft lithography-based microfluidic flow chamber for biofilm growth and a screen with the Tn-mutant library in microtiter plates. The screen identified hitherto unknown genes involved in biofilm growth and antibiotic resistance. Experiments conducted with the flow chamber across three laboratories delivered reproducible data on P. aeruginosa biofilms and validated the function of both known genes and genes identified in the Tn-mutant screens. Differential Protein abundance data from planktonic cells versus biofilm confirmed the upregulation of candidates known to affect biofilm formation, of structural and secreted proteins of type VI secretion systems, and provided proteogenomic evidence for some missed MPAO1 genes. This integrated, broadly applicable model promises to improve the mechanistic understanding of biofilm formation, antimicrobial tolerance, and resistance evolution in biofilms. KW - Biofilms PY - 2020 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-515108 DO - https://doi.org/10.1038/s41522-020-00154-8 VL - 6 IS - 1 SP - Article number: 46 PB - Springer Nature CY - Singapore AN - OPUS4-51510 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Keshmiri, Hamid A1 - Armin, F. A1 - Elsayad, K. A1 - Schreiber, Frank A1 - Moreno, M. T1 - Leaky and waveguide modes in biperiodic holograms N2 - This study details a theoretical analysis of leaky and waveguide modes in biperiodic all-dielectric holograms. By tuning diffraction orders and subsequently confining local density of optical states at two distinct resonance wavelengths, we present a new class of highly sensitive refractive index biosensing platforms that are capable of resolving 35.5 to 41.3 nm/RIU of spectral shift for two separate biological analytes. KW - Antimicrobial resistance KW - Bacteria KW - Photonics KW - Diffractive gratings PY - 2021 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-527632 DO - https://doi.org/10.1038/s41598-021-89971-1 SN - 2045-2322 (online) VL - 11 IS - 1 SP - 10991 PB - Springer Nature AN - OPUS4-52763 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Pietsch, Franziska A1 - O'Neill, A. J. A1 - Ivask, A. A1 - Jenssen, H. A1 - Inkinen, J. A1 - Kahru, A. A1 - Ahonen, M. A1 - Schreiber, Frank T1 - Selection of resistance by antimicrobial coatings in the healthcare setting N2 - Antimicrobial touch surfaces have been introduced in healthcare settings with the aim of supporting existing hygiene procedures, and to help combat the increasing threat of antimicrobial resistance. However, concerns have been raised over the potential selection pressure exerted by such surfaces, which may drive the evolution and spread of antimicrobial resistance. This review highlights studies that indicate risks associated with resistance on antimicrobial surfaces by different processes, including evolution by de-novo mutation and horizontal gene transfer, and species sorting of inherently resistant bacteria dispersed on to antimicrobial surfaces. The review focuses on antimicrobial surfaces made of copper, silver and antimicrobial peptides because of the practical application of copper and silver, and the promising characteristics of antimicrobial peptides. The available data point to a potential for resistance selection and a subsequent increase in resistant strains via cross-resistance and co-resistance conferred by metal and antibiotic resistance traits. However, translational studies describing the development of resistance to antimicrobial touch surfaces in healthcare-related environments are rare, and will be needed to assess whether and how antimicrobial surfaces lead to resistance selection in These settings. Such studies will need to consider numerous variables, including the antimicrobial concentrations present in coatings, the occurrence of biofilms on surfaces, and the humidity relevant to dry-surface environments. On-site tests on the efficacy of antimicrobial Coatings should routinely evaluate the risk of selection associated with their use. KW - Antimicrobial resistance KW - Antimicrobial coating KW - Touch surfaces KW - Healthcare KW - Infections KW - COST action CA15114 AMICI PY - 2020 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-510926 DO - https://doi.org/10.1016/j.jhin.2020.06.006 SN - 0195-6701 VL - 106 IS - 1 SP - 115 EP - 125 PB - Elsevier Ltd AN - OPUS4-51092 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Braetz, S. A1 - Nordholt, Niclas A1 - Nerlich, A. A1 - Schreiber, Frank A1 - Tedin, K. A1 - Fulde, M. T1 - TisB enables antibiotic tolerance in Salmonella by preventing prophage induction through ATP depletion N2 - Antibiotic persistence comprises drug-tolerant bacteria that can survive treatment with antibacterial agents, despite lacking classical genetic resistance mechanisms. Therefore, persisters are clinically relevant because they can lead to treatment failures and chronic infections. Additionally, antibiotic persistence facilitates the evolution of resistance through genetic mutations. Persisters are triggered by a lack of nutrients, bacterial toxins, low ATP levels, or other stress responses that shut down bacterial metabolism. However, the involvement of prophages, viruses that integrate into bacterial chromosomes, is less well understood. In this study, we tested a tisAB deletion in Salmonella Typhimurium and examined persister cell formation following treatment with the DNA-damaging drug ciprofloxacin. TisB is a bacterial toxin that increases the influx of protons across the inner bacterial membrane into the cytosol, causing ATP depletion. We demonstrate that the deletion of tisAB increases prophage induction and bacterial killing, leading to a reduced persister cell fraction. The tisAB mutant is unable to down regulate its ATP concentration after exposure to ciprofloxacin, which in turn allows for stronger binding of RecA to single-stranded DNA, the activator of both the SOS response and prophage induction. KW - Antimicrobial resistance KW - Bacterial survival mechanisms KW - Escherichia coli KW - Salmonella typhimurium PY - 2025 DO - https://doi.org/10.1371/journal.ppat.1013498 IS - 9 SP - 1 EP - 23 AN - OPUS4-64642 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Nordholt, Niclas A1 - O'Hara, Kate A1 - Resch-Genger, Ute A1 - Blaskovich, M. A1 - Rühle, Bastian A1 - Schreiber, Frank T1 - A fluorescently labelled quaternary ammonium compound (NBD-DDA) to study resistance mechanisms in bacteria N2 - Quaternary ammonium compounds (QACs) are widely used as active agents in disinfectants, antiseptics, and preservatives. Despite being in use since the 1940s, there remain multiple open questions regarding their detailed mode-of-action and the mechanisms, including phenotypic heterogeneity, that can make bacteria less susceptible to QACs. To facilitate studies on resistance mechanisms towards QACs, we synthesized a fluorescent quaternary ammonium compound, namely N-dodecyl-N,N-dimethyl-[2-[(4-nitro-2,1,3-benzoxadiazol-7-yl)amino]ethyl]azanium-iodide (NBD-DDA). NBD-DDA is readily detected by flow cytometry and fluorescence microscopy with standard GFP/FITC-settings, making it suitable for molecular and single-cell studies. As a proof-of-concept, NBD-DDA was then used to investigate resistance mechanisms which can be heterogeneous among individual bacterial cells. Our results reveal that the antimicrobial activity of NBD-DDA against Escherichia coli, Staphylococcus aureus and Pseudomonas aeruginosa is comparable to that of benzalkonium chloride (BAC), a widely used QAC, and benzyl-dimethyl-dodecylammonium chloride (BAC12), a mono-constituent BAC with alkyl-chain length of 12 and high structural similarity to NBD-DDA. Characteristic time-kill kinetics and increased tolerance of a BAC tolerant E. coli strain against NBD-DDA suggest that the mode of action of NBD-DDA is similar to that of BAC. As revealed by confocal laser scanning microscopy (CLSM), NBD-DDA is preferentially localized to the cell envelope of E. coli, which is a primary target of BAC and other QACs. Leveraging these findings and NBD-DDA‘s fluorescent properties, we show that reduced cellular accumulation is responsible for the evolved BAC tolerance in the BAC tolerant E. coli strain and that NBD-DDA is subject to efflux mediated by TolC. Overall, NBD-DDA’s antimicrobial activity, its fluorescent properties, and its ease of detection render it a powerful tool to study resistance mechanisms of QACs in bacteria and highlight its potential to gain detailed insights into its mode-of-action. KW - Antimicrobial resistance KW - Bacteria KW - Disinfection KW - Biocides PY - 2022 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-563811 DO - https://doi.org/10.3389/fmicb.2022.1023326 SN - 1664-302X IS - 13 SP - 1 EP - 13 PB - Frontiers Media CY - Lausanne AN - OPUS4-56381 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Valentin, J. A1 - Straub, H. A1 - Pietsch, Franziska A1 - Lemare, M. A1 - Ahrens, C. A1 - Schreiber, Frank A1 - Webb, J. A1 - van der Mei, H. A1 - Ren, Q. T1 - Role of the flagellar hook in the structural development and antibiotic tolerance of Pseudomonas aeruginosa biofilms N2 - Pseudomonas aeruginosa biofilms exhibit an intrinsic resistance to antibiotics and constitute a considerable clinical threat. In cystic fibrosis, a common feature of biofilms formed by P. aeruginosa in the airway is the occurrence of mutants deficient in flagellar motility. This study investigates the impact of flagellum deletion on the structure and antibiotic tolerance of P. aeruginosa biofilms, and highlights a role for the flagellum in adaptation and cell survival during biofilm development. Mutations in the flagellar hook protein FlgE influence greatly P. aeruginosa biofilm structuring and antibiotic tolerance. Phenotypic analysis of the flgE knockout mutant compared to the wild type (WT) reveal increased fitness under planktonic conditions, reduced initial adhesion but enhanced formation of microcolony aggregates in a microfluidic environment, and decreased expression of genes involved in exopolysaccharide formation. Biofilm cells of the flgE knock-out mutant display enhanced tolerance towards multiple antibiotics, whereas its planktonic cells show similar resistance to the WT. Confocal microscopy of biofilms demonstrates that gentamicin does not affect the viability of cells located in the inner part of the flgE knock-out mutant biofilms due to reduced penetration. These findings suggest that deficiency in flagellar proteins like FlgE in biofilms and in cystic fibrosis infections represent phenotypic and evolutionary adaptations that alter the structure of P. aeruginosa biofilms conferring increased antibiotic tolerance. KW - Antimicrobial resistance KW - Bacteria KW - Biofilms KW - Biocides PY - 2021 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-541113 DO - https://doi.org/10.1038/s41396-021-01157-9 SN - 1751-7370 VL - 16 IS - 4 SP - 1176 EP - 1186 PB - Springer Nature AN - OPUS4-54111 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Li, M. A1 - Schlaich, C. A1 - Zhang, J. A1 - Donskyi, Ievgen A1 - Schwibbert, Karin A1 - Schreiber, Frank A1 - Xia, Y. A1 - Radnik, Jörg A1 - Schwerdtle, T. A1 - Haag, R. T1 - Mussel-inspired multifunctional coating for bacterial infection prevention and osteogenic induction N2 - Bacterial infection and osteogenic integration are the two main problems that cause severe complications after surgeries. In this study, the antibacterial and osteogenic properties were simultaneously introduced in biomaterials, where copper nanoparticles (CuNPs) were generated by in situ reductions of Cu ions into a mussel-inspired hyperbranched polyglycerol (MI-hPG) coating via a simple dip-coating method. This hyperbranched polyglycerol with 10 % catechol groups’ modification presents excellent antifouling property, which could effectively reduce bacteria adhesion on the surface. In this work, polycaprolactone (PCL) electrospun fiber membrane was selected as the substrate, which is commonly used in biomedical implants in bone regeneration and cardiovascular stents because of its good biocompatibility and easy post-modification. The as-fabricated CuNPs-incorporated PCL membrane [PCL-(MI-hPG)-CuNPs] was confirmed with effective antibacterial performance via in vitro antibacterial tests against Staphylococcus aureus (S. aureus), Escherichia coli (E. coli), and multi-resistant E. coli. In addition, the in vitro results demonstrated that osteogenic property of PCL-(MI-hPG)-CuNPs was realized by upregulating the osteoblast-related gene expressions and protein activity. This study shows that antibacterial and osteogenic properties can be balanced in a surface coating by introducing CuNPs. KW - Mussel-inspired coating KW - CuNPs KW - Multi-resistant bacteria KW - Antibacterial KW - Antifouling KW - Osteogenesis PY - 2021 DO - https://doi.org/10.1016/j.jmst.2020.08.011 SN - 1005-0302 VL - 68 SP - 160 EP - 171 PB - Elsevier Ltd. AN - OPUS4-51519 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Feller, Viktor A1 - Mielentz, Frank A1 - Klewe, T. A1 - Krause, Martin A1 - Orglmeister, R. A1 - Pflugradt, M. T1 - Ultrasonic phased array for investigations of concrete components N2 - This paper describes an innovation of a phased array using dry contact probes to test concrete components. Based on preceding work on pressure waves, a low-frequency ultrasonic phased array consisting of shear wave probes is used in the experiments. This configuration allows the variation and control of the sound field directivity during the measurement. The measurements are carried out on a concrete test block using a scanning laservibrometer and a scanner system in transmission mode. The laboratory measurements are compared to theoretical calculations to investigate the influence of the probes shape and dimension on the resulting sound field patterns. The comparison of the modelling and the measurements demonstrates the suitability of the point source synthesis as a tool for the optimization of probe array designs. Methods of coded are used to improve the signal to noise ratio. T2 - NDT-CE 2015 - International symposium non-destructive testing in civil engineering CY - Berlin, Germany DA - 15.09.2015 KW - Ultrasonic KW - Phased array KW - Concrete KW - Point source synthesis PY - 2015 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-350417 UR - http://www.ndt.net/article/ndtce2015/papers/059_feller_viktor.pdf SN - 1435-4934 SP - 1 EP - 5 PB - Technische Universität Berlin / Bundesanstalt für Materialforschung und -prüfung AN - OPUS4-35041 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Abbas, Ioana M. A1 - Schwaar, Timm A1 - Bienwald, Frank A1 - Weller, Michael G. T1 - Predictable Peptide Conjugation Ratios by Activation of Proteins with Succinimidyl Iodoacetate (SIA) N2 - The small heterobifunctional linker succinimidyl iodoacetate (SIA) was examined for the preparation of peptide–protein bioconjugates with predicable conjugation ratios. For many conjugation protocols, the protein is either treated with a reductant to cleave disulfide bonds or is reacted with thiolation chemicals, such as Traut’s reagent. Both approaches are difficult to control, need individual optimization and often lead to unsatisfactory results. In another popular approach, a heterobifunctional linker with a N-hydroxysuccinimide (NHS) and a maleimide functionality is applied to the protein. After the activation of some lysine ε-amino groups with the NHS ester functionality, a cysteine-containing peptide is attached to the activated carrier protein via maleimide. Particularly, the maleimide reaction leads to some unwanted byproducts or even cleavage of the linker. Many protocols end up with conjugates with unpredictable and irreproducible conjugation ratios. In addition, the maleimide-thiol addition product should be assumed immunogenic in vivo. To avoid these and other disadvantages of the maleimide approach, we examined the known linker succinimidyl iodoacetate (SIA) in more detail and developed two protocols, which lead to peptide–protein conjugates with predefined average conjugation ratios. This holds potential to eliminate tedious and expensive optimization steps for the synthesis of a bioconjugate of optimal composition. KW - Bioconjugate KW - Carrier protein KW - Immunogen KW - Hapten KW - Linker KW - Antibody drug conjugate KW - ADC KW - Drug-to-antibody ratio KW - DAR KW - Conjugation ratio KW - Conjugation density KW - Carrier load KW - Click reaction KW - Click chemistry PY - 2017 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-427188 UR - http://www.mdpi.com/2409-9279/1/1/2 DO - https://doi.org/10.3390/mps1010002 SN - 2409-9279 VL - 1 SP - 1 EP - 14 PB - MDPI CY - Basel, Schweiz AN - OPUS4-42718 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Gonzalez III, F. A1 - Prabhakaran, A. A1 - Robitaille, A. A1 - Booth, G. A1 - Birk, A.M. A1 - Otremba, Frank T1 - Rail tank car total containment fire testing: planning & test development N2 - Given the frequent incidences of Non-Accident Releases (NARs) of hazardous materials from tank cars, there in an increasing interest in transporting hazardous materials in total containment conditions (i.e., no pressure relief devices). However, the ability of tank cars to meet thermal protection requirements provided in the Code of Federal Regulations under conditions of total containment has not been established. Also, the modeling tool commonly used by industry to evaluate thermal protection, AFFTAC, has not been validated under these conditions. The intent of this effort was to evaluate through a series of third-scale fire tests, the ability of tank cars to meet the thermal protection requirements under total containment conditions, and also, to validate AFFTAC for such conditions. This paper describes the test design and planning effort associated with this research, including the design and evaluation of a fire test setup to simulate a credible, fully engulfing, pool fire that is consistent and repeatable, and the design and hydro-static testing of a third-scale tank specimen. The fire design includes controls on the spatial distribution and temperature variation of the flame temperature, the heat flux, and the radiative balance, to best reflect large liquid hydrocarbon pool fire conditions that may be experienced during derailment scenarios. T2 - JRC2015 - Joint rail conference CY - San Jose, CA, USA DA - 23.03.2015 PY - 2015 SP - 5764, 1 EP - 6 AN - OPUS4-32985 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wolf, Julia A1 - Mielentz, Frank A1 - Milmann, Boris A1 - Helmerich, Rosemarie A1 - Köpp, Christian A1 - Wiggenhauser, Herbert A1 - Kurz, J.H. A1 - Moryson, R.M. A1 - Samokrutov, A. A1 - Alekhin, S. G. A1 - Alver, Ninel A1 - Sazak, H.Ö. T1 - An ultrasound monitoring system for concrete structures N2 - The research project "Ultrasonic Net for Concrete Monitoring (UNeCOM)" aims at developing a methodology for an embedded ultrasonic network for the condition assessment of infrastructure constructions. Civil engineering structures made of concrete, which are located in tectonically active regions or undergo special loading conditions, may require continuous monitoring. It is important to assess the condition of the building and its stability to recognise and classify the effect of a seismic event or evolving damage at early stages before failure occurs. Embedded ultrasonic sensors offer the possibility to detect changes in the material and degradation mechanisms from inside the structure in areas which are difficult or impossible to inspect otherwise. In contrast to conventional ultrasonic testing methods, where the concrete surfaces are scanned with ultrasound probes, this new approach uses sensors, which are embedded into concrete, eliminating the effect of variable coupling conditions between sensors and concrete. This method allows an integral detection of changes in the concrete structure, for example due to seismic activities, to detect mechanical impacts, as well as degradation of the material due to overloading. Such methods have great relevance especially for the monitoring of constructions like power plants, bridges, offshore structures and other structures with high technical safety requirements. The sensor network can be controlled remotely through the internet which is also being used for data transfer. The embedded sensor network is designed to monitor structural damage and concrete degradation globally with high sensitivity. T2 - Istanbul bridge conference 2014 CY - Istanbul, Turkey DA - 11.08.2014 KW - Ultrasound KW - Concrete KW - Monitoring PY - 2014 SN - 978-605-64131-6-2 SP - Paper 32, 1 EP - 9 AN - OPUS4-32028 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Jentsch, H. A1 - Schwartz, A. A1 - Basedau, Frank A1 - Bazrafshan, K. A1 - Döring, H. A1 - Großwig, S. A1 - Hofmann, Detlef A1 - Kowalle, G. A1 - Kusche, Nadine A1 - Lorenz, R. A1 - Pfeiffer, T. A1 - Sadaghiani, M.R.S. A1 - Scholz, E. A1 - Senze, A. A1 - Tkachenko, Viktoriya A1 - Witt, K. J. ED - Xu, Y. L. ED - Zhu, S. ED - Xia, Y. ED - Ni, Y.Q. ED - Law, S.S. ED - Yin, J. H. ED - Su, Z.Q. T1 - Detection of slipping soil areas with embedded tiny vertical sensing rods N2 - Critical soil zones where large areas along a shear joint might begin to slip should be recognized. In order to avoid damage, monitoring of such unstable zones is necessary. First, soil movements must be detected as early as possible, second, the amount of deformation should be estimated. Because geodetical methods do not provide information about deformation in the underground in different depths, the only way to come to information from possible shear zones is the installation of deformation measurement systems. A special installation method was developed to bring a long-gauge length measurement system into a borehole and transfer data of soil deformations into an installed sensing rod. The mostly vertically installed sensing rod has an outer diameter of 3 mm to 6 mm and contains several optical fibres. One fibre provides integral strain information along the whole length of the rod. To get this information, the phase difference between the fibre input and output is measured and the change of the total length of the fibre can be derived. This easy and cheap online sensing system delivers an early warning of soil deformations respectively possible slip as well as landslides. In case of warning, the second sensing system based on Fibre Bragg Grating sensors located close to the expected shear zone purposefully. It records resulting deformations in detail. In this study, three main objectives were achieved: a) development of tiny pultruded sensing rods with integrated optical sensor fibres, b) installation technology which enables the integration of the sensing rod during drilling and pile driving, and c) development of a stiff but elastic racking material to fix the rod in the soil and to transfer soil deformation into the stiffer sensing rod. These three aspects including the fibre optical measurement systems are described; results from Press Deformation Test (PDT) are presented. Test results of the fibre optical online system are compared and evaluated with the results of conventional inclinometer measurements as well as numerical modelling. An outlook for further possibilities of usage of this monitoring system is given. T2 - SHMII-6 - 6th International conference on structural health monitoring of intelligent infrastructure CY - Hong Kong, China DA - 09.12.2013 KW - Structural health monitoring KW - Soil stability monitoring KW - Optical fibre strain-sensor KW - Geotechnical soil stability KW - Soil deformation modelling PY - 2013 SN - 978-962-367-768-4 SP - 1 EP - 9 AN - OPUS4-29915 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bradley, I. A1 - Birk, A.M. A1 - Otremba, Frank A1 - Gonzalez III, F. A1 - Prabhakaran, A. A1 - Bisby, L. T1 - Development and characterisation of an engulfing hydrocarbon pool fire test for hazardous materials pressure vessels N2 - The US Department of Transportation, Federal Railroad Administration (FRA) current regulations for rail tank cars in the United States stipulate that, for certain hazardous materials, tank cars shall have a thermal protection system capable of preventing rupture of the tank for 100 minutes when exposed to an engulfing fire with a blackbody equivalent flame temperature of 871 °C (+/- 56°C), and that tanks shall have a pressure relief device set at an appropriate level (depending on the type of tank car and contents). Pressure relief devices are a source of non-accident releases, and hence may cause serious incidents when tanks are transporting hazardous materials. Industry in North America would therefore benefit from removal of pressure relief devices on tanks transporting certain hazardous materials. Such an approach is known as full Containment, and is standard practice in Europe. In 2014 the FRA commissioned an experimental study to investigate the ability of a specific design of rail tank to resist rupture without incorporating a pressure release valve. As a precursor to tests on tanks there was a need to develop and characterise a simulated pool fire capable of reliably exposing large-scale tanks to repeatable, uniform conditions. This paper describes such a fire test setup, developed using a burner array system fuelled by liquid propane and designed to produce luminous, low velocity flames representative of those found in large hydrocarbon pool fires. The experimental set-up is described, along with the Instrumentation (directional flame thermometers, infra-red camera, and thermally massive calorimeter) and methodology used to characterise the fire. Comparisons are made against previous fire tests on vessels to assess the suitability of the experimental set-up for future vessel testing. T2 - CONFAB 2015 - 1st International conference on structural safety under fire & blast CY - Glasgow, UK DA - 02.09.2015 PY - 2015 SP - 485 EP - 494 AN - OPUS4-34545 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Esteban-Fernández, D. A1 - Bierkandt, Frank A1 - Linscheid, M.W. T1 - MeCAT labeling for absolute quantification of intact proteins using labelspecific isotope dilution ICP-MS N2 - Sensitive, accurate and fast absolute quantification of intact proteins is reported using metal coded affinity tags (MeCATs) combined with gel electrophoresis (GE) separation, inductively coupled plasma mass spectrometry (ICP-MS) detection and label-specific isotope dilution analysis quantification. Two different approaches were investigated concerning the introduction of the sample into ICP-MS, mineralization of the gel and direct laser ablation (LA) of the spot. Three major advantages are remarkable in the proposed method. First, not only heteroatom-containing proteins but also all labeled proteins in the sample can be absolutely quantified preparing an isotopically enriched tracer. On the other hand, highly sensitive determination in the amol range can be performed, considerably reducing the analysis time due to the straightforward measurements by ICP-MS. Furthermore, the studied method allows accurate quantifications with different sample-to-spike ratios and using stock spikes stored for months. After the first characterization using standard proteins, human serum albumin (HSA) and transferrin (Tf) were determined in human serum to test the applicability of the method to biological samples. The results show satisfactory quantifications for the studied proteins despite the difference in concentration and the similarity in migration distances. PY - 2012 DO - https://doi.org/10.1039/c2ja30137g SN - 0267-9477 SN - 1364-5544 VL - 27 IS - 10 SP - 1701 EP - 1708 PB - Royal Society of Chemistry CY - London AN - OPUS4-27777 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wolf, Julia A1 - Milmann, Boris A1 - Helmerich, Rosemarie A1 - Köpp, Christian A1 - Mielentz, Frank A1 - Wiggenhauser, Herbert A1 - Kurz, J.H. A1 - Moryson, R.-M. A1 - Samokrutov, A. A1 - Alekhin, S. G. A1 - Alver, Ninel A1 - Sazak, H.-Ö. ED - Xu, Y. L. ED - Zhu, S. ED - Xia, Y. ED - Ni, Y.Q. ED - Law, S.S. ED - Yin, J. H. ED - Su, Z.Q. T1 - Ultrasound based monitoring system for concrete monolithic objects N2 - Ultrasound sensors should be embedded into concrete for monitoring concrete properties. These new longitudinal wave sensors with a center frequency of 60 kHz were examined regarding their suitability for ultrasonic measurements in concrete structures in terms of emission characteristics, sensitivity and frequency ränge. For the measurement of the radiation patterns, the sensors were embedded vertically and horizontally in concrete cylinders. The directivity pattern was measured using a laser vibrometer. The sensitivity of the sensor was determined in water using different sensors of the same type. It shows changes in the signal amplitude as well as variations in the frequency ränge for different transmitter-receiver combinations. The attenuation of the concrete affects the achievable resolution of the measurements and thus, the maximum possible spacing of the sensors within a concrete element. Experimental tests helped optimizing the distances with respect to the required resolution and the effort of embedding the sensors. The signal attenuation in the concrete was measured in the frequency ränge of 60 kHz in response to various degrees of reinforcement and grain size. For this purpose, the sensors were cast at different distances in the specimens studied. The recorded Signals were evaluated for their amplitude and frequency spectrum. T2 - SHMII-6 - 6th International conference on structural health monitoring of intelligent infrastructure CY - Hong Kong, China DA - 09.12.2013 KW - Ultrasound KW - Concrete KW - Monitoring system KW - Ultrasonic network KW - Embedded sensor PY - 2013 SN - 978-962-367-768-4 SP - 1 EP - 6 AN - OPUS4-29642 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Heap, M.J. A1 - Lavallée, Y. A1 - Laumann, A. A1 - Hess, K.-U. A1 - Meredith, P.G. A1 - Dingwell, D.B. A1 - Huismann, Sven A1 - Weise, Frank T1 - The influence of thermal-stressing (up to 1000 °C) on the physical, mechanical, and chemical properties of siliceous-aggregate, high-strength concrete N2 - High-strength concrete (HSC) will experience thermal microcracking, explosive spalling, and undesirable chemical changes when exposed to high temperatures, such as during fire, engulfment by lava flow, or nuclear meltdown. Knowledge of the resultant changes in mechanical, physical, and chemical properties is paramount for hazard mitigation. We present a multidisciplinary study on the influence of thermal-stressing on HSC. Our study shows that thermal microcracking in HSC initiates at 180 °C, is more prevalent during cooling, and exhibits the Kaiser 'temperature-memory' effect. We show that residual compressive strength, indirect tensile strength, ultrasonic wave velocities, and Young’s modulus and Poisson’s ratio decrease, whilst porosity and permeability increase with increasing temperature. We discuss these data in terms of the chemical changes during thermal-stressing, provided by thermo-gravimetric analysis, differential scanning calorimetry, and X-ray diffraction, and from optical microscopic analysis of thermally-stressed samples. We provide implications for thermally-damaged HSC structures and a new method for non-destructive monitoring. KW - High strength concrete KW - Fire KW - Thermal-stressing KW - Acoustic emissions KW - Physical properties KW - Elastic moduli KW - Uniaxial compressive strength KW - Indirect tensile strength KW - Thermo-gravimetric analysis KW - X-ray diffraction PY - 2013 DO - https://doi.org/10.1016/j.conbuildmat.2013.01.020 SN - 0950-0618 VL - 42 SP - 248 EP - 265 PB - Elsevier Ltd. CY - Amsterdam AN - OPUS4-27992 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -