TY - JOUR A1 - Lu, Xin A1 - Königsbauer, Korbinian A1 - Hicke, Konstantin T1 - Improved phase retrieval method for system simplification or fading suppression in interferometer-based φOTDR systems N2 - Phase sensitive optical time domain reflectometry (φOTDR) systems based on different types of interferometers for phase retrieval typically require two or three photodetectors to record the outputs from the interferometer. A novel signal processing principle is proposed for phase retrieval by taking the difference between two outputs as the quadrature component and reconstructing the in-phase component via Hilbert transformation of the Q component for IQ demodulation. Thus, only one balanced photodetector or two standard photodetectors are need, reducing system complexity and data volume. This principle can also be used to suppress fading effect for the traditional three-detector φOTDR systems by selecting optimal phases across detector pairs. Experiments with a φOTDR systems based on an imbalanced Mach-Zehnder interferometer validate the feasibility of this method and demonstrate a high fading suppression of about 90%. KW - Phase retrieval KW - Distributed fiber sensing KW - Structural health monitoring PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-652630 DO - https://doi.org/10.1364/OE.580984 SN - 1094-4087 VL - 33 IS - 26 SP - 54733 EP - 54746 PB - Optica Publishing Group AN - OPUS4-65263 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Wagner, Jan A1 - Häfner, P. A1 - Reimann, H.-A. A1 - Schartel, Bernhard T1 - Valorization of Natural Fibers in Flame Retarded Poly(lactic acid) N2 - Extensive research has explored natural fiber reinforced composites, typically focusing on a single fiber within a polymer matrix. Comprehensive comparisons across different natural fibers in the same polymer, which are critical for industrial material selection, remain limited. This work presents a systematic comparison of untreated hemp, flax, and sisal fibers incorporated at varying fiber lengths and loadings into flame retarded poly(lactic acid) (PLA). Fire behavior, thermal, and mechanical responses were investigated through thermogravimetry, UL 94, and cone calorimetry, alongside crystallinity, molecular weight (MW), and microstructural analysis. Fiber incorporation reduced the peak heat release rate (pHRR) by up to 30 % in 30 wt% hemp, attributed to protective layer formation, but increased flammability in UL 94. A phytic acid melamine salt combined with expandable graphite and 20 wt% hemp produced incomplete combustion at 50 kW/m², raising char residue from 4 to 24 wt% and halving pHRR. Petrella plots revealed that fiber addition alone lowered fire load and flashover propensity as effectively as phytic acid melamine; with hemp, phytic acid and expendable graphite, the flashover hazard and fire load were halved. MW was preserved while crystallinity and modulus increased with fiber content. Hemp delivered the most consistent reinforcement, while optimized processing enabled flax and sisal to improve stiffness. Performance gains were strongest when individual fibers were dispersed via optimized processing, preventing bundle fracture under load. Plasma modification of the fibers improved the maximum tensile strength in the composites. A practical guide is provided for valorizing natural fibers in PLA composites, demonstrating routes to bio-based, compostable materials with improved fire safety and mechanical performance suitable for industrial processing. KW - Poly(lactic acid) KW - Hemp KW - Sisal KW - Flax KW - Flame retardant KW - Phytic acid PY - 2026 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-653038 DO - https://doi.org/10.1016/j.mtcomm.2025.114575 SN - 2352-4928 VL - 50 SP - 1 EP - 41 PB - Elsevier Ltd. AN - OPUS4-65303 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Cairns, Warren R. L. A1 - Braysher, Emma C. A1 - Butler, Owen T. A1 - Cavoura, Olga A1 - Davidson, Christine M. A1 - Todoli Torro, Jose Luis A1 - von der Au, Marcus T1 - Atomic spectrometry update: review of advances in environmental analysis N2 - This review covers advances in the analysis of air, water, plants, soils and geological materials by a range of atomic spectrometric techniques including atomic emission, absorption, fluorescence and mass spectrometry. KW - Environmental analysis KW - Review KW - Trend Article PY - 2026 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-653977 DO - https://doi.org/10.1039/D5JA90058A SN - 0267-9477 VL - 41 IS - 1 SP - 16 EP - 70 PB - Royal Society of Chemistry (RSC) AN - OPUS4-65397 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bresch, Harald A1 - Unger, Wolfgang A1 - Schulte, Petra T1 - Nanotechnologie Aktivitäten der BAM N2 - Die Präsentation gibt einen Überblick über die verschiedenen Aktivitäten der BAM im Bereich der Nanotechnologie mit den Schwerpunkten Nanopartikel und Nanosicherheit. Es wird sowohl die Transportsicherheit, als auch die Sicherheit von Batterien mit Nanopartikeln angesprochen. Verschiedene BAM-Projekte zum Thema Nano werden vorgestellt, beginnend mit relevanten REFOPlanprojekten über die Erstellung der OECD nanoTG110 bis hin zu EU-Projekten zur Standardisierung von Messungen an Nanomaterialien, hier insbesondere AEROMET, NanoDefine, NanoValid und EC4SafeNano. T2 - Nano-Behördenklausur der Bundesoberbehörden CY - Berlin, Germany DA - 02.11.2017 KW - Nano KW - Nanotechnologie KW - Nanopartikel KW - Nanosicherheit KW - Nanoanalytik PY - 2017 AN - OPUS4-42793 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Aumont, Cédric T1 - Harnessing near-chromosome level quality genomes to explore the evolution of termite immunity N2 - The phylogeny of the Blattodea boasts a wide degree of sociality spanning from solitary cockroaches to advanced ecosystem-dominating higher termite societies. The emergence of sociality in termites was associated with the acquisition of a diverse range of social structures. Previous work has found evidence for a caste-specific social defence system in termites leading to an immune system that may favour group over individual defence. While preliminary work suggests a correlation between social transitions and a reduction of immune gene family diversity, the lack of available high-quality termite genomes hampers complete knowledge of the true diversity of immune gene evolution across termite phylogeny. Here, we report on the sequencing and near-chromosome level assembly of 48 high-quality long-read-based genomes across major termite and cockroach sister-branch lineages. We investigate the diversity and evolutionary history of immune genes across genomes, focusing particular attention on correlations between immune gene evolution and transitions in sociality over termite phylogeny. T2 - Royal Entomological Society Annual Meeting - Ento23 CY - University of Exeter, Falmouth, UK DA - 05.09.2023 KW - Immune gene family KW - Termite phylogeny KW - Eusociality KW - Group defence PY - 2023 AN - OPUS4-58296 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Aumont, Cédric T1 - Immune gene family diversity across insects and Blattodea N2 - Insecta is one of the most diverse phyla in the animal kingdom, with species living in all types of habitats encountering an even greater diversity of pathogens and parasites. Defence strategies against such harmful threats led to a variety of molecular mechanisms, ecological shifts, and genetic innovations. Gene families underlying the molecular basis of the immune responses have evolved within the boundaries given by the species ecology. Here, we explore the evolution of some emblematic immune gene families throughout the Insecta phylum shedding light on remarkable genetic events such as gene duplication or gene loss. We followed a workflow based on the Hidden Markov model to search for immune genes in 55 high-quality genomes of insects. We highlight the emergence of group defence in social species as an ecological shift that released selection pressure on immune gene families notably in Blattodea. Further, we draw attention to certain gene families and the link between their diversity and the specificities of the species’ microbiota. Overall, we report data on immune gene diversity in insects. T2 - International Conference for Blattodea Research CY - Münster, Germany DA - 03.04.2023 KW - Immune gene family KW - Genomics KW - Blattodea PY - 2023 AN - OPUS4-58298 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - McMahon, Dino Peter T1 - Evolutionary genomics of termite sociality N2 - Termite sociality is thought to have evolved around 150 million years ago and is therefore ancient. Reconstructing the transitions that led to the evolution of this group of ecologically dominant insect societies is challenging. We sought to address this by sequencing near-chromosome-quality genomes from the major solitary, subsocial and social lineages of termites and their nearest blattodean relatives. We present findings from a comparative analysis of the sequenced genomes, where we explore the molecular underpinnings of termite sociality, and seek to understand the evolutionary origins of termite castes. At a broader scale, we test the extent to which a two-step process involving an initial expansion of genomic elements in cockroaches followed by extensive genome rearrangements in termites, may have acted as an important mechanism of evolutionary change. We then ask whether specific genomic processes may have facilitated evolutionary novelty, for example, through the analysis of transposon-host gene associations across the social gradient. We also report on findings that combine genomes with brain transcriptomics to explore the mechanistic basis of termite phenotypic plasticity, thereby enabling a first large-scale comparative genomic analysis of the evolutionary origins of termite sociality. T2 - International Congress of Entomology (ICE) 2024 CY - Kyoto, Japan DA - 25.08.2024 KW - Termite KW - Reference genome KW - Genomics PY - 2024 AN - OPUS4-61648 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Aumont, Cédric T1 - Exploring the evolution of termite immunity across phylogeny, sociality and foraging behaviour N2 - The phylogeny of the Blattodea boasts a wide degree of sociality spanning from solitary cockroaches to advanced ecosystem-dominating termite societies. The emergence of sociality in termites was associated with the acquisition of a diverse range of social structures and caste-specific behaviours. From wood-dwelling to fungus-growing and cooperative scouting, termite foraging strategies require different immune defences to confront the diverse pathogens found in the foraging environment. Previous work has found evidence for a caste-specific social defence system in termites leading to an immune system that may favour group over individual defence. While preliminary work suggests a correlation between social transitions and a reduction of immune gene family diversity, the lack of available high-quality termite genomes hampers complete knowledge of the true diversity of immune gene evolution across termite phylogeny. Here, we report on the sequencing and near-chromosome level assembly of 47 high-quality long-read-based genomes across major termite and cockroach sister-branch lineages. We investigate the diversity and evolutionary history of immune genes across genomes, focusing on correlations between immune gene evolution, transitions in sociality and foraging behaviour diversity over termite phylogeny. T2 - ASAB Spring Meeting CY - Exeter, UK DA - 23.04.2024 KW - Termite KW - Immunity PY - 2024 AN - OPUS4-61695 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Aumont, Cédric T1 - The social brain of termites: investigating gene co-expression network in the Blattodea N2 - The transition to eusociality in termites arose from the sub-social and solitary cockroaches. With it, a more complex ontogeny derived from an ancestral linear developmental pathway common to all cockroaches and a wide array of morphologically distinct castes carrying out the division of labour emerged. We sought to underpine the complexity of this evolutionary transition at the transcriptomic level. We present the gene co-expression network analysis of 305 RNA-seq samples from the brains of 15 species of cockroaches and termites from different instars and castes. With this dataset, we investigate how the network of gene evolved between solitary cockroaches, sub-social cockroach and eusocial termites. Moreover, we investigate the emergence of the two most striking evolutionary innovations in termites, the appearance of the soldier caste, common in nearly all termites and thought to have evolved once and subsequently lost in some species, and the true worker caste, the sterile workforce of the colony thought to have derived from the totipotent false worker caste in four different lineages of termites independently. T2 - International Congress of Entomology CY - Kyoto, Japan DA - 25.08.2024 KW - Termite KW - Genetics PY - 2024 AN - OPUS4-61696 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Neamtu, Mariana T1 - Preparation, characterization and application of magnetic Fe3O4/PEG nanoparticles immobilized with ferrous oxalate or ferric citrate for removal of bisphenol A from aqueous solution N2 - The scope of our study was to prepare Fe-based highly active catalysts for water treatment processes. The reactive nanomaterials were synthesized by chemical precipitation; the post-synthesis coating of the as obtained nanostructures was achieved by capping the magnetic cores with a polymeric surfactant, polyethylene glycol (PEG). The resulted Fe3O4/PEG nanoparticles were further used to immobilize two types of reactive materials on their surface, either ferrous oxalate (FO) or ferric citrate (FC), yielding the final products – two green Fenton-like heterogeneous nanocatalysts. The sensitized catalysts were characterized by several microstructure characterization techniques such as X-ray diffraction (XRD), vibrating sample magnetometry, BET, scanning electron microscopy (SEM), and energy dispersive X-ray spectroscopy (EDX). All experiments were performed on a laboratory scale set-up. Important variables such as effect of hydrogen peroxide concentration, UV light, the amount of catalyst and contact time for the catalytic wet peroxide oxidation (CWHPO) of BPA were examined. The results indicate that the oxidation rate increased under UV light in the presence of low-concentration H2O2. T2 - Designing New Heterogeneous Catalysts Faraday Discussion CY - London, UK DA - 04.04.2016 KW - Nanocatalysts KW - Characterization KW - Fenton oxidation KW - Wastewater KW - Bisphenol A degradation PY - 2016 AN - OPUS4-40077 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bresch, Harald T1 - Forschungsprojekte an der BAM N2 - Übersicht über die laufenden Projekte der BAM mit Bezug zur Nano-Thematik. Der Fokus liegt auf der Entwicklung der OECD-Prüfrichtlinie zur Partikelgrößenverteilung und auf den Projekten, die einen Anknüpfungspunkt für die anderen Bundesoberbehörden bilden könnten. T2 - Behördenklausur zur Nanosicherheit 2019 CY - Berlin, Germany DA - 26.06.2019 KW - Bundesoberbehörden KW - Nano KW - Behördenklausurtagung PY - 2019 AN - OPUS4-49575 LA - deu 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 - Kotschate, Daniel T1 - Signalverarbeitung zur hochauflösenden Reinheitsgradbestimmung N2 - Basierend auf aktuellen Regelwerken (SEP1927 und ASTM E588) stehen Möglichkeiten zur nichtinvasiven Beurteilung des zu untersuchenden Werkstoffes, in verschiedenen Qualitätsstufen bis zu einer Vergleichsfehlergröße von bis zu 300 Mikrometer zur Verfügung. Allerdings ist der realistische Nachweis und die Beurteilung von künstlichen sowie von natürlichen Fehlern kleiner 500 Mikrometer nur unter optimalen Voraussetzungen (bspw. Wahl des Prüfkopfes, Geometrie des Prüfobjektes, orts- bzw. zeitliche Auflösung der Messdatenaufnahme) und unter Einsatz von geeigneten Signalverarbeitungsalgorithmen möglich. Im Rahmen von Ringversuchen wurden daher verschiedene Methoden zur Aufbereitung der zu erfassenden Messdaten entwickelt und an verschiedenen Bauteilgeometrieen und Werkstoffen getestet. Dabei stellten sich der spektrale Tiefenausgleich (SDAC) und die nichtlineare Bewertung einzelner Frequenzkomponenten des Nutzsignals als sehr vielversprechend heraus und die Nachweisbarkeit kleiner Fehler - im Bereich von 100 - 500 μm - konnte erfolgreich gesteigert werden. T2 - DGZfP Jahrestagung CY - Koblenz, Germany DA - 22.05.2017 KW - Materialcharakterisierung KW - Reinheitsgradbestimmung KW - Ultraschalltauchtechnik PY - 2017 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-403523 AN - OPUS4-40352 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN T1 - Forschungsprogramm 2015 - 2017 N2 - Globalisierung und die beschleunigte technologische Entwicklung bringen heute für die Industrieländer Herausforderungen im Hinblick auf Wachstum, Beschäftigung und Strukturwandel mit sich, denen nur mit einer entsprechenden Innovationsdynamik und -dichte begegnet werden kann. Grundvoraussetzung hierfür ist eine leistungsfähige Forschung und Entwicklung ebenso wie Wissens- und Technologietransfer zur Umsetzung von Forschungsergebnissen in marktfähige Produkte und Dienstleistungen. Europa hat sich im Rahmen des Lissabon-Prozesses zum Ziel gesetzt, den Anteil der Forschungsausgaben am Bruttoinlandsprodukt auf 3 % zu steigern. Um die Forschungsinfrastruktur in der Bundesrepublik zu stärken und global wettbewerbsfähig zu bleiben, hat die Bundesregierung mit der Hightech-Strategie einen weiteren wichtigen Schritt zur Förderung des wissenschaftlich-technischen Fortschritts in Deutschland getan. Forschungsprogramme sind sowohl für Forschungseinrichtungen als auch für Mittelgeber ein wichtiges Instrument für die Darstellung und Steuerung ihrer Aktivitäten. Dies gilt auch für die Bundeseinrichtungen mit Forschungs- und Entwicklungsaufgaben, zu denen die Bundesanstalt für Materialforschung und -prüfung (BAM) zählt. Die BAM verfügt über einen klaren gesetzlichen Auftrag für die Sicherheit in Technik und Chemie. Ihre Forschung ist mit der Wahrnehmung öffentlicher Aufgaben verbunden. Das Forschungsprogramm zeigt Perspektiven im Bereich ihres Aufgabenfeldes sowie ihrer damit verbundenen Forschungsaktivitäten transparent und politisch nutzbar auf und dient darüber hinaus der Koordinierung der Ressortforschung. Das Forschungsprogramm der BAM wird alle zwei Jahre aktualisiert. Es gibt einen Überblick über die aktuellen und zukünftigen Forschungsthemen und die hierfür erforderlichen Rahmenbedingungen. PY - 2015 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-421401 SP - 1 EP - 40 PB - Bundesanstalt für Materialforschung und -prüfung (BAM) CY - Berlin AN - OPUS4-42140 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Pfeiffer, F. A1 - Bagyan, I. A1 - Alfaro Espinoza, Gabriela A1 - Zamora-Lagos, M.-A. A1 - Habermann, B. A1 - Marin-Sanguino, A. A1 - Oesterhelt, D. A1 - Kunte, Hans-Jörg T1 - Revision and reannotation of the Halomonas elongata DSM 2581(T) genome N2 - The genome of the Halomonas elongata type strain DSM 2581, an industrial producer, was reevaluated using the Illumina HiSeq2500 technology. To resolve duplication-associated ambiguities, PCR products were generated and sequenced. Outside of duplications, 72 sequence corrections were required, of which 24 were point mutations and 48 were indels of one or few bases. Most of these were associated with polynucleotide stretches (poly-T stretch overestimated in 19 cases, poly-C underestimated in 15 cases). These problems may be attributed to using 454 technology for original Genome sequencing. On average, the original genome sequence had only one error in 56 kb. There were 23 frameshift error corrections in the 29 protein-coding genes affected by sequence revision. The genome has been subjected to major reannotation in order to substantially increase the annotation quality. KW - Frameshift KW - Genome annotation KW - Genome sequencing KW - Halomonas elongata KW - Halophilic bacteria KW - Sequence revision PY - 2017 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-403292 DO - https://doi.org/10.1002/mbo3.465 SN - 2045-8827 VL - 6 IS - 4 SP - Article e465, 1 EP - 6 PB - Wiley AN - OPUS4-40329 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Illerhaus, Bernhard A1 - Maenz, S. A1 - Bischoff, S. A1 - Bungartz, M. A1 - Bossert, J. A1 - Kunisch, E. A1 - Kinne, R. ED - Maenz, S. T1 - Micro computer tomography (μCT) set-up for long-term serial measurements, image evaluation, and subsequent compressive strength tests on frozen sheep vertebrae for osteoporosis research N2 - Injection of poly(methyl methacrylate) cements, one standard Treatment for osteoporotic vertebral body fractures, may lead to critical loads and subsequent fractures in adjacent vertebral bodies. Biodegradable calcium phosphate cements (CPC) with bioinductive growth factors may be an alternative, since they have a Young’s modulus comparable to that of cancellous bone. Non-destructive tests with μCT and quantitative Image evaluation are used to assess new bone growth and material resorption following intravertebral injection of CPC. Immediate deep-freezing of excised bone prevents shrinkage or tissue disintegration and the samples have to be kept frozen for all following steps, including transport, μCT measurements, and subsequent biomechanical tests. Here we will report on a set-up to preserve the frozen state of the material and allow stable long-term serial μCT measurements. In addition, the image processing technique for the evaluation of bone growth and selected results on subsequently carried out compressive strength tests will be presented. T2 - WCNDT2016 CY - München, Germany DA - 13.6.2016 KW - Computed tomography KW - Osteoporosis KW - CT PY - 2016 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-366410 UR - https://www.ndt.net/?id=19382 VL - BB 158 SP - 1 EP - 7 PB - DGZfP CY - Berlin AN - OPUS4-36641 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Pavlovic, Mato A1 - Müller, Christina A1 - Ronneteg, U. T1 - Reliability Analysis of the Phased-Array Ultrasonic System used for the Inspection of Friction Stir Welds N2 - The canister for the permanent storage of spent nuclear fuel used by SKB in Sweden consists of a cast iron insert surrounded by a five centimetre thick shell of copper. It is a safety critical component and in order to secure long-term structural integrity non-destructive methods are used to inspect 100% of the volume of each canister, before it is disposed of in the repository. One of the critical components that requires inspection is a sealing weld, joining the copper tube and the lid. The friction stir weld is inspected using an ultrasonic phased array system. The area of the weld is inspected with several inspection channels with different angles and varying coverage. To make sure that no defects that might occur in the weld are overseen, the reliability of the inspection must be quantified. The reliability of NDT is usually quantified with the probability of detection curves. The influence of the parameters that might influence the POD of the flaws in the weld is investigated analysing the experimental results, as well as with a help of a numerical simulation of the inspection. T2 - 19th Wolrd Conference on Nondestructive Testing CY - Munich, Germany DA - 13.06.2016 KW - NDT KW - Ultrasonic KW - Reliability KW - POD KW - Copper KW - FSW KW - JLH PY - 2016 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-366982 VL - 2016/158 SP - We.4.E.5 PB - Deutsche Gesellschaft für zerstörungsfreie Prüfung (DGZfP) CY - Berlin AN - OPUS4-36698 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schlick-Hasper, Eva A1 - Schneider, Uwe A1 - Goedecke, Thomas A1 - Kraume, M. T1 - Durchströmung von Glaskapillaren mit Lachgas und Helium N2 - Distickstoffmonoxid (N2O, Lachgas) und Helium (He) sind gängige Prüfgase für Dichtheitsprüfungen. Die einfachste Leckgeometrie stellt ein ideal zylindrisches Rohr dar. Es wurden Glaskapillaren verschiedener Abmessungen mit Lachgas und Helium durchströmt. Der Überdruck am Kapillareingang lag zwischen 100 mbar und 400 mbar. Es handelte sich um vier annähernd zylindrische Glaskapillaren mit den mittleren Durchmessern: Kapillare 1: ca. 102 μm; Kapillare 2: ca. 71 μm; Kapillare 3B: ca. 49 μm; Kapillare 4: ca. 53 μm. Zudem wurde eine nichtzylindrische Kapillare geprüft (Kapillare 3A). Die Kapillaren 1, 2 und 3B wurden mit beiden Prüfgasen getestet. Kapillare 3A wurde nur mit Lachgas durchströmt, Kapillare 4 nur mit Helium. Für die Messung der Leckageraten kam das Überdruckverfahren mit Ansammlung (Verfahren B3 nach DIN EN 1779: 1999-10) zum Einsatz. Als Detektor für Lachgas diente der Lachgasdetektor Maihak Unor 6 N, für Helium der Leckdetektor T-Guard der Firma Inficon. Es wurden verschiedene Theorieansätze verglichen. Beim Theorieansatz Ib erfolgte die Umrechnung der Lachgas-Messwerte auf die Helium-Messwerte und umgekehrt anhand der Druck-, Temperatur- und Gasartabhängigkeit der Leckagerate für laminar-viskose Gasströmung (DIN EN 1779: 1999-10; DGZfP-Richtlinie DP2: 2009-12). Beim Theorieansatz II wurde die Berechnung der Leckagerate für die laminar-viskose Rohrströmung unter der Annahme einer ideal zylindrischen Kapillare durchgeführt. Zusätzlich wurde mit „ANSYS Fluent“ eine CFD-Simulation vorgenommen. Bei Kapillare 3A wurde eine Serienschaltung der Strömungsleitwerte von Rohr und Düse angesetzt. Bei Anwendung des Ansatzes Ib werden bei Umrechnung der Helium-Messwerte auf Lachgas die Lachgas-Messwerte überschätzt. Umgekehrt werden bei der Umrechnung der Lachgas-Messwerte auf Helium die Helium-Messwerte unterschätzt. Bei Analyse der Einlauflängen der Rohrdurchströmung ist festzustellen, dass diese für Lachgas stets größer als für Helium sind. Bei Lachgas liegt daher für einige Messwerte noch keine ausgebildete laminare Rohrströmung vor. Einlaufeffekte können somit nicht vernachlässigt werden. Als Fazit ergibt sich, dass bei Verwendung von Helium als Prüfgas und Umrechnung der Helium-Messwerte auf Lachgas die Lachgas-Leckageraten sicherheitstechnisch konservativ abgeschätzt werden. T2 - 7. DGZfP-Fachseminar Dichtheitsprüfung und Lecksuche CY - Dortmund, Germany DA - 20.09.2016 KW - Glaskapillaren KW - Lachgas KW - Helium KW - Laminare Strömung PY - 2017 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-396659 UR - http://www.ndt.net/search/docs.php3?MainSource=215 SN - 1435-4934 VL - 22 IS - 4 SP - Vortrag 5, 1 EP - 15 AN - OPUS4-39665 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Wiedensohler, A. A1 - Wiesner, A. A1 - Weinhold, K. A1 - Birmili, W. A1 - Herrmann, M. A1 - Merkel, M. A1 - Müller, T. A1 - Pfeifer, S. A1 - Schmidt, A. A1 - Tuch, T. A1 - Velarde, F. A1 - Quincey, P. A1 - Seeger, Stefan A1 - Nowak, A. T1 - Mobility particle size spectrometers: Calibration procedures and measurement uncertainties N2 - Mobility particle size spectrometers (MPSS) belong to the essential instruments in aerosol science that determine the particle number size distribution (PNSD)in the submicrometer size range. Following calibration procedures and target uncertainties against standards and reference instruments are suggested for a complete MPSS quality assurance program: a) calibration of the CPC counting efficiency curve (within 5% for the plateau counting efficiency; within 1 nm for the 50% detection efficiency diameter), b) sizing calibration of the MPSS, using a certified polystyrene latex (PSL) particle size standard at 203 nm (within 3%), c) intercomparison of the PNSD of the MPSS (within 10% and 20% of the dN/dlogDP concentration for the particle size range 20 – 200 nm and 200 to 800 nm, respectively), and d) intercomparison of the integral PNC of the MPSS (within 10%). Furthermore, following measurement uncertainties have been investigated: a) PSL particle size standards in the range from 100-500nm match within 1% after sizing calibration at 203 nm. b) Bipolar diffusion chargers based on the radioactive nuclides Kr85, Am241 and Ni63 and a new ionizer based on corona discharge follow the recommended bipolar charge distribution, while soft X-ray-based charges may alter faster than expected. c) The use of a positive high voltage supply show a 10% better performance than a negative one. d) The intercomparison of the integral PNC of an MPSS against the total number concentration is still within the target uncertainty at an ambient pressure of approximately 500 hPa. KW - Measurement uncertainties KW - Mobility particle size spectrometer (MPPS) KW - Condensation particle counter (CPC) KW - Calibration PY - 2017 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-425060 DO - https://doi.org/10.1080/02786826.2017.1387229 SN - 1521-7388 VL - 52 IS - 2 SP - 146 EP - 164 PB - Tailor & Francis CY - USA AN - OPUS4-42506 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -