TY - JOUR A1 - Breitenbach, Romy A1 - Silbernagl, Dorothee A1 - Toepel, J. A1 - Sturm, Heinz A1 - Broughton, William J. A1 - Sassaki, G. L. A1 - Gorbushina, Anna T1 - Corrosive extracellular polysaccharides of the rock-inhabiting model fungus Knufia petricola N2 - Melanised cell walls and extracellular polymeric matrices protect rock-inhabiting microcolonial fungi from hostile environmental conditions. How extracellular polymeric substances (EPS) perform this protective role was investigated by following development of the model microcolonial black fungus Knufia petricola A95 grown as a sub-aerial biofilm. Extracellular substances were extracted with NaOH/formaldehyde and the structures of two excreted polymers studied by methylation as well as NMR analyses. The main polysaccharide (~ 80%) was pullulan, also known as α-1,4-; α-1,6-glucan, with different degrees of polymerisation. Αlpha-(1,4)-linked-Glcp and α-(1,6)-linked-Glcp were present in the molar ratios of 2:1. A branched galactofuromannan with an α-(1,2)-linked Manp main chain and a β-(1,6)-linked Galf side chain formed a minor fraction (~ 20%). To further understand the roles of EPS in the weathering of minerals and rocks, viscosity along with corrosive properties were studied using atomic force microscopy (AFM). The kinetic viscosity of extracellular K. petricola A95 polysaccharides (≈ 0.97 × 10-6 m2 s-1) ranged from the equivalent of 2% (w/v) to 5% glycerine, and could thus profoundly affect diffusion-dominated processes. The corrosive nature of rock-inhabiting fungal EPS was also demonstrated by its effects on the aluminium coating of the AFM cantilever and the silicon layer below. KW - Corrosion KW - EPS KW - Melanised microcolonial fungi (MCF) KW - Pullulan KW - Sub-aerial biofilms (SAB) KW - α-1,4- and α-1,6-glucans KW - AFM cantilever vibration KW - Nanoviscosity KW - Nanocorrosion of aluminium and silicon PY - 2017 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-435910 DO - https://doi.org/10.1007/s00792-017-0984-5 SN - 1433-4909 SN - 1431-0651 VL - 22 IS - 2 SP - 165 EP - 175 PB - Springer CY - Berlin AN - OPUS4-43591 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Schröter, Maria-Astrid A1 - Meyer, Susann A1 - Hahn, Marc Benjamin A1 - Solomun, Tihomir A1 - Sturm, Heinz A1 - Kunte, Hans-Jörg T1 - Ectoine protects DNA from damage by ionizing radiation N2 - Ectoine plays an important role in protecting biomolecules and entire cells against environmental stressors such as salinity, freezing, drying and high temperatures. Recent studies revealed that ectoine also provides effective protection for human skin cells from damage caused by UV-A radiation. These protective properties make ectoine a valuable compound and it is applied as an active ingredient in numerous pharmaceutical devices and cosmetics. Interestingly, the underlying mechanism resulting in protecting cells from radiation is not yet fully understood. Here we present a study on ectoine and its protective influence on DNA during electron irradiation. Applying gel electrophoresis and atomic force microscopy, we demonstrate for the first time that ectoine prevents DNA strand breaks caused by ionizing electron radiation. The results presented here point to future applications of ectoine for instance in cancer radiation therapy. KW - Plasmid DNA pUC19 KW - Electron irradiation 30 [kV] KW - Effective irradiation dose 0.2-16 [Gy] KW - Gel electrophoresis KW - AFM intermittent contact KW - Radioprotector ectoine KW - Compatible solute PY - 2017 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-428287 DO - https://doi.org/10.1038/s41598-017-15512-4 SN - 2045-2322 VL - 7 IS - 1 SP - 15272, 1 EP - 15272, 7 PB - Nature AN - OPUS4-42828 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Teixeira, M.M. A1 - Moreno, L.F. A1 - Stielow, B.J. A1 - Muszewska, A. A1 - Hainaut, M. A1 - Gonzaga, L. A1 - Abouelleil, A. A1 - Patan, J.S.L. A1 - Priest, M. A1 - Souza, R. A1 - Ferreira, K.S. A1 - Zeng, Q. A1 - da Cunha, M.M.L. A1 - Gladki, A. A1 - Barker, B. A1 - Vicente, V.A. A1 - de Souza, E.M. A1 - Almeida, S. A1 - Henrissat, B. A1 - Vasconelos, A.T.R. A1 - Deng, S. A1 - Vogelmayr, H. A1 - Moussa, T.A.A. A1 - Gorbushina, Anna A1 - Felipe, M.S.S. A1 - Cuomo, C.A. A1 - de Hoog, G.S. T1 - Exploring the genomic diversity of black yeasts and relatives (Chaetothyriales, Ascomycota) N2 - The order Chaetothyriales (Pezizomycotina, Ascomycetes) harbours obligatorily melanised fungi and includes numerous etiologic agents of chromoblastomycosis, phaeohyphomycosis and other diseases of vertebrate hosts. Diseases range from mild cutaneous to fatal cerebral or disseminated infections and affect humans and cold-blooded animals globally. In addition, Chaetothyriales comprise species with aquatic, rock-inhabiting, ant-associated, and mycoparasitic life-styles, as well as species that tolerate toxic compounds, suggesting a high degree of versatile extremotolerance. To understand their biology and divergent niche occupation, we sequenced and annotated a set of 23 genomes of main the human opportunists within the Chaetothyriales as well as related environmental species. Our analyses included fungi with diverse life-styles, namely opportunistic pathogens and closely related saprobes, to identify genomic adaptations related to pathogenesis. Furthermore, ecological preferences of Chaetothyriales were analysed, in conjuncture with the order-level phylogeny based on conserved ribosomal genes. General characteristics, phylogenomic relationships, transposable elements, sex-related genes, protein family evolution, genes related to protein degradation (MEROPS), carbohydrate-active enzymes (CAZymes), melanin synthesis and secondary metabolism were investigated and compared between species. Genome assemblies varied from 25.81 Mb (Capronia coronata) to 43.03 Mb (Cladophialophora immunda). The bantiana-clade contained the highest number of predicted genes (12 817 on average) as well as larger genomes. We found a low content of mobile elements, with DNA transposons from Tc1/Mariner superfamily being the most abundant across analysed species. Additionally, we identified a reduction of carbohydrate degrading enzymes, specifically many of the Glycosyl Hydrolase (GH) class, while most of the Pectin Lyase (PL) genes were lost in etiological agents of chromoblastomycosis and phaeohyphomycosis. An expansion was found in protein degrading peptidase enzyme families S12 (serine-type D-Ala-D-Ala carboxypeptidases) and M38 (isoaspartyl dipeptidases). Based on genomic information, a wide range of abilities of melanin biosynthesis was revealed; genes related to metabolically distinct DHN, DOPA and pyomelanin pathways were identified. The MAT (MAting Type) locus and other sexrelated genes were recognized in all 23 black fungi. Members of the asexual genera Fonsecaea and Cladophialophora appear to be heterothallic with a single copy of either MAT-1-1 or MAT-1-2 in each individual. All Capronia species are homothallic as both MAT1-1 and MAT1-2 genes were found in each single genome. The genomic synteny of the MAT-locus flanking genes (SLA2-APN2-COX13) is not conserved in black fungi as is commonly observed in Eurotiomycetes, indicating a unique genomic context for MAT in those species. The heterokaryon (het) genes expansion associated with the low selective pressure at the MAT-locus suggests that a parasexual cycle may play an important role in generating diversity among those fungi. KW - Black yeast KW - Comparative genomics KW - Chaetothyriales KW - Ecology KW - Evolution KW - Herpotrichiellaceae KW - Phylogeny PY - 2017 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-408720 DO - https://doi.org/10.1016/j.simyco.2017.01.001 SN - 1872-9797 VL - 86 IS - 1 SP - 1 EP - 28 PB - Elsevier CY - Amsterdam AN - OPUS4-40872 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Dackermann, U. A1 - Yu, Y. A1 - Niederleithinger, Ernst A1 - Li, J. A1 - Wiggenhauser, Herbert T1 - Condition Assessment of Foundation Piles and Utility Poles Based on Guided Wave Propagation Using a Network of Tactile Transducers and Support Vector Machines N2 - This paper presents a novel non-destructive testing and health monitoring system using a network of tactile transducers and accelerometers for the condition assessment and damage classification of foundation piles and utility poles. While in traditional pile integrity testing an impact hammer with broadband frequency excitation is typically used, the proposed testing system utilizes an innovative excitation system based on a network of tactile transducers to induce controlled narrow-band frequency stress waves. Thereby, the simultaneous excitation of multiple stress wave types and modes is avoided (or at least reduced), and targeted wave forms can be generated. The new testing system enables the testing and monitoring of foundation piles and utility poles where the top is inaccessible, making the new testing system suitable, for example, for the condition assessment of pile structures with obstructed heads and of poles with live wires. For system validation, the new system was experimentally tested on nine timber and concrete poles that were inflicted with several types of damage. The tactile transducers were excited with continuous sine wave signals of 1 kHz frequency. Support vector machines were employed together with advanced signal processing algorithms to distinguish recorded stress wave signals from pole structures with different types of damage. The results show that using fast Fourier transform signals, combined with principal component analysis as the input feature vector for support vector machine (SVM) classifiers with different kernel functions, can achieve damage classification with accuracies of 92.5% ± 7.5%. KW - Structural Health Monitoring KW - Non-Destructive Testing KW - Sensor network KW - Support vector machine KW - Utility poles PY - 2017 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-434868 UR - http://www.mdpi.com/1424-8220/17/12/2938 DO - https://doi.org/10.3390/s17122938 SN - 1424-8220 VL - 17 IS - 12 SP - Article 2938, 1 EP - 16 PB - MDPI CY - Basel, Schweiz AN - OPUS4-43486 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Stengel, Dominik A1 - Thiele, K. T1 - Measurements of downburst wind loading acting on an overhead transmission line in Northern Germany N2 - Along an overhead transmission line in Northern Germany, a unique instrumentation of anemometers and force measurements is installed. Details of this test line with wind measurements along a horizontal axis are given. A recent event of a presumable downburst wind event is analyzed by means of available data and precedent works on thunderstorm analysis. The measured response of the conductors at the suspension tower is investigated and compared with time domain simulation of a finite element model. T2 - X International Conference on Structural Dynamics, EURODYN 2017 CY - Rome, Italy DA - 10.09.2017 KW - Non-synoptic wind event KW - Downburst KW - Overhead transmission line KW - Finite element method PY - 2017 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-421239 DO - https://doi.org/10.1016/j.proeng.2017.09.578 SN - 1877-7058 VL - 199 IS - Supplement C SP - 3152 EP - 3157 PB - Elsevier AN - OPUS4-42123 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Auersch, Lutz T1 - Mitigation of railway induced vibration at the track, in the transmission path through the soil and at the building N2 - This contribution presents some principles and some examples of the mitigation of railway-induced ground vibrations. The principles are different for the mitigation measures at the track, in the soil or at the building. Force transfer functions of isolated and un-isolated track-soil systems, reflected and transmitted wave amplitudes at walls and trenches in the soil, and the transfer of the (free-field) vibration amplitudes to the foundation amplitudes of the building are analysed. The mitigation effect can be calculated by exact or simplified formulas. Some examples with 3D (finite-element boundary-element), 2D (beam-on-support), and 1D track models, 2D and 1D soil models, detailed 3D building models and finite or infinite 1D wall-floor models are investigated to find out if simple models can be used for a satisfactory prediction of the mitigation effect. The 1D track examples show that the force transfer of the track without vehicle can be exactly calculated, whereas the total force transfer can be calculated approximately if appropriate wheelset masses per track length are used for the isolated and the un-isolated track. The mitigation effect of a filled trench is calculated by a 2D finite element model and the results compare with simple transmission formula if the stiffness per area rather than the wave impedances are used for the infill material. The base isolation of a building is analysed by a detailed 3D model and the results are similar to the analytic results of a single wall with floors on the soil. Other reduction measures as different floor and column dimensions are usually less effective so that the clearly best mitigation solution at a building is a partly or a complete base isolation. T2 - X INTERNATIONAL CONFERENCE ON STRUCTURAL DYNAMICS (EURODYN 2017) KW - Mitigation KW - Soil-building interaction KW - Base isolation KW - Ground vibration PY - 2017 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-420869 DO - https://doi.org/10.1016/j.proeng.2017.09.192 SN - 1877-7058 VL - 199 SP - 2312 EP - 2317 PB - Elsevier CY - London AN - OPUS4-42086 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Auersch, Lutz A1 - Said, Samir A1 - Müller, Roger T1 - Measurements on the vehicle-track interaction and the excitation of railway-induced ground vibration N2 - Two railway measurement campaigns have been performed in Germany and Switzerland which yield insight in the vehicle-track-soil interaction. The campaign in Germany has included simultaneous measurement of vehicle, track, and soil vibrations during train runs with 16, 25, 40, 63, 80, 100, 125, 140, 160 km/h, and impulse measurements of the passenger car, three track sections and the soil. Two ballast tracks, one on the soil surface and one on a concrete bridge, have been investigated as well as a slab track in a tunnel. Ten different sites in Switzerland have been measured for soil properties and train-induced ground vibrations, which allow to determine the excitation forces of the railway traffic. New axle-box measurements at some of the Swiss sites have been analysed to get further experimental evidence. All these measurements have been evaluated to characterize the excitation processes. Relations between vehicle vibration and ground vibration can be observed. The vehicle vibrations, namely the accelerations of the wheelsets, yield the dynamic forces due to the passage over the irregularities of the vehicle and the track. The ground vibrations are correlated to these dynamic forces to a certain extent. Some mid-frequency ground vibration amplitudes, however, are higher than expected from the dynamic excitation forces. The experimental observations can be explained by an irregular response to the passage of the static loads, that means the passage of the static loads over an irregular ballast or soil. This correct understanding of the excitation processes is important for the prediction as well as for the mitigation of railway induced ground vibrations. T2 - X INTERNATIONAL CONFERENCE ON STRUCTURAL DYNAMICS (EURODYN 2017) KW - Vehicle-track interaction KW - Ground vibration KW - Track vibration KW - Railway measurement campaign KW - Axle box measurements PY - 2017 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-420889 DO - https://doi.org/10.1016/j.proeng.2017.09.390 SN - 1877-7058 VL - 199 SP - 2615 EP - 2620 PB - Elsevier CY - London AN - OPUS4-42088 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Pohl, Rainer A1 - Casperson, Ralf A1 - Maierhofer, Christiane A1 - Müller, Jan A1 - Pelkner, Matthias T1 - Gegenüberstellung von Wirbelstromprüfung und aktiver Thermografie an CFK-Versuchskörpern N2 - In vielen Bereichen der Technik haben Konstruktionen unter Einsatz von CFK-Bauteilen und Komponenten die klassischen Metalle abgelöst. Die zerstörungsfreie Prüfung solcher CFK-Bauteile gewinnt somit zunehmend an Bedeutung. Ein mögliches Prüfverfahren ist dabei die Wirbelstromprüfung. Aufgrund der relativ geringen elektrischen Leitfähigkeit von CFK-Komponenten kommt hierbei häufig die sogenannte HF-Wirbelstromprüfung zum Einsatz. In verschiedenen Untersuchungen der BAM konnten jedoch auch mit Wirbelstromprüfsystemen in niedrigen Frequenzbereichen gute Ergebnisse erzielt werden. Um die Möglichkeiten und Grenzen dieser konventionellen Wirbelstromprüfung auszuloten, wurden Messungen an Versuchskörpern durchgeführt, welche bereits bei der Validierung der Blitz- und Lock-in-Thermografie für neue Verfahrensnormen erfolgreich eingesetzt wurden. Ein Typ dieser Versuchskörper sind Flachproben aus CFK von 6 mm Dicke. In diesen wurden Flachbodenbohrungen mit Durchmessern zwischen 4 mm und 24 mm eingebracht. Die Restwandstärken liegen zwischen 0,06 mm und 3,66 mm. Ein weiterer CFK-Versuchskörper hat die Geometrie eines Stufenkeiles. Bei verschiedenen Stufenkeilen sind Wanddicken zwischen 1,4 mm und 5,4 mm realisiert worden. In diesen wurden künstliche quadratische Delaminationen mit Kantenlängen zwischen 2 mm und 20 mm eingebracht. Die Ergebnisse der Wirbelstromprüfung werden denen der aktiven Thermografie gegenübergestellt. Zur Nachbildung von Kompositwerkstoffen wurden die flachen Versuchskörper mit geeigneten Versuchskörpern aus Aluminium und Stahl kombiniert. Die Wirbelstromprüfungen wurden mit einem handelsüblichen Prüfgerät im Frequenzbereich zwischen 500 Hz und 3 MHz und entsprechend angepassten Sensoren durchgeführt. T2 - DGZfP Jahrestagung 2017 CY - Koblenz, Germany DA - 22.05.2017 KW - Wirbelstromprüfung KW - Aktive Thermografie KW - CFK PY - 2017 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-403607 SN - 978-3-940283-85-6 VL - 162 SP - 1 EP - 10 PB - Deutsche Gesellschaft für Zerstörungsfreie Prüfung (DGZfP) CY - Berlin AN - OPUS4-40360 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bertovic, Marija A1 - Kanzler, D. A1 - Pavlovic, Mato A1 - Holstein, R. T1 - Aktueller Stand der Diskussion zur Zuverlässigkeit der ZfP und den menschlichen Faktoren N2 - Dass die Zuverlässigkeit der ZfP eine sehr wichtige Rolle bei der Bewertung sicherheitsrelevanter Systeme spielt, ist bekannt. Laut dem modularen Zuverlässigkeitsmodell für zerstörungsfreie Prüfprozesse hängt die Zuverlässigkeit von der innewohnenden (physikalisch-technischen) Fähigkeit der Prüfsystems, den Anwendungsparametern, den menschlichen Faktoren und dem organisatorischen Kontext ab. Seit Einführung des Modells während des ersten Workshops zur Zuverlässigkeit der ZfP (European-American Workshop on Reliability of NDE) wurde das Modell in weiteren fünf Workshops stetig weiterentwickelt, diskutiert und an den Stand der Wissenschaft angepasst. Das Ziel dieser Publikation ist es, den aktuellen Stand der Diskussion und die neusten Fragestellungen der internationalen Zuverlässigkeitsgemeinschaft vorzustellen. Im Einzelnen werden die Entwicklung fortgeschrittener Modelle zur Bewertung der Probability of Detection (POD), Bewertungsansätze im Bereich Structural Health Monitoring und Fragestellungen zu den menschlichen Faktoren dargestellt. Besonderer Wert wurde sowohl auf die Entwicklung, als auch auf die Anwendung der Ansätze in der industriellen Praxis gelegt. T2 - DGZfP-Jahrestagung 2017 CY - Koblenz, Germany DA - 22.05.2017 KW - Zuverlässigkeit KW - Zerstörungsfreie Prüfung KW - Probability of detection KW - Human factors KW - Reliability PY - 2017 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-404861 SN - 978-3-940283-85-6 VL - DGZfP-Berichtsband BB 162 SP - 1 EP - 7 AN - OPUS4-40486 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Mitzscherling, Steffen A1 - Barth, Enrico A1 - Götschel, S. A1 - Homann, Tobias A1 - Prager, Jens A1 - Weiser, M. T1 - Verbesserung und Qualifizierung der Ultraschallprüfung von Mischnähten im Primärkreis von KKW N2 - Die im Primärkreislauf von Kernkraftwerken anzutreffenden austenitischen Schweiß- und Mischnähte sind nicht nur extrem sicherheitsrelevant, sondern stellen auch sehr hohe Anforderungen an die Materialprüfung. Neben der eingeschränkten Zugänglichkeit ist das makroskopische Gefüge der Schweißnaht für die Prüfung mit Ultraschall von höchster Bedeutung. Um Materialfehler zuverlässig in Position und Größe bestimmen zu können, müssen die Kornorientierungen und die elastischen Konstanten des anisotropen Schweißnahtgefüges bekannt sein. Für die bildgebende Darstellung möglicher Materialfehler kommen folgende Arbeitsschritte zum Einsatz: Zunächst wird die Schweißnaht durchschallt, um mit einem inversen Verfahren wichtige Schweißnahtparameter wie beispielsweise die Kornorientierung bestimmen zu können. Auf der Basis dieser Parameter werden im nächsten Schritt die Schallwege mittels Raytracing (RT) simuliert. Zuletzt werden dieser RT-Simulation die Messdaten (A-Scans) von verschiedenen Sender- und Empfängerpositionen zugeordnet und nach der SAFT-Methode (Synthetic Aperature Focusing Technique) zeitaufgelöst überlagert. Die Kombination aus inversem Verfahren, RT und SAFT gewährleistet auch in anisotropen Werkstoffen eine ortsrichtige Visualisierung der Fehler. Wir erläutern diese drei Verfahren und stellen die Prüfanordnung von Prüfkörpern mit künstlichen Testfehlern vor. Messdaten sowie deren Auswertung werden mit den Ergebnissen einer CIVA-Simulation verglichen. T2 - DGZfP-Jahrestagung 2017 CY - Koblenz, Germany DA - 22.05.2017 KW - Zerstörungsfreie Prüfung KW - Ultraschall KW - SAFT KW - Schweißnaht KW - Austenit PY - 2017 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-404329 SN - 978-3-940283-85-6 VL - DGZfP BB 162 SP - P16, 1 EP - 8 AN - OPUS4-40432 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -