TY - JOUR A1 - Lange, T. A1 - Heinrich, Sebastian A1 - Liebner, Christian A1 - Hieronymus, Hartmut A1 - Klemm, E. T1 - Reaction engineering investigations of the heterogeneously catalyzed partial oxidation of o-xylene in the explosion regime using a microfixed bed reactor N2 - The heterogeneously catalyzed selective gas phase oxidation of o-xylene was investigated, using a microstructured fixed bed reactor, inside of the explosion regime. The reaction was carried out with high amounts of o-xylene in air and stoichiometric with oxygen using a V2O5/TiO2-catalyst prepared through grafting. There were no significant losses in the selectivity to phthalic anhydride observable, during the measurements in the explosion regime, with feed compositions of up to 7 vol% o-xylene. Also the space-time yield was up to 2.3 times higher in comparison to conventional reaction conditions. An increase of the selectivity to total oxidation products was observed at higher o-xylene concentrations between 10 and 25 vol% o-xylene, which possibly was caused by the formation of a hotspot. The investigation of the used catalyst revealed a thermally induced deactivation due to phase transition of anatase into rutil and formation of crystalline vanadium oxide. Despite that expected hotspot at high oxylene concentrations, there was no ignition or explosion of the gas mixture observable. KW - O-xylene oxidation KW - Phthalic anhydride KW - V2O5/TiO2-catalyst KW - Microfixed bed reactor KW - Explosion regime KW - Hotspot PY - 2012 DO - https://doi.org/10.1016/j.ces.2011.10.072 SN - 0009-2509 VL - 69 IS - 1 SP - 440 EP - 448 PB - Elsevier Ltd. CY - Amsterdam AN - OPUS4-25463 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Fayis Kalady, Mohammed A1 - Schultz, Johannes A1 - Weinel, Kristina A1 - Wolf, Daniel A1 - Lubk, Axel T1 - Geometry-dependent localization of surface plasmons on random gold nanoparticle assemblies N2 - Assemblies of plasmonic nanoparticles (NPs) support hybridized modes of localized surface plasmons (LSPs), which delocalize in geometrically well-ordered arrangements. Here, the hybridization behavior of LSPs in geometrically completely disordered two-dimensional arrangements of Au NPs fabricated by an e-beam synthesis method is studied. Employing electron energy loss spectroscopy in a scanning transmission electron microscope and numerical simulations, the disorder-driven spatial and spectral localization of the coupled LSP modes that depends on the NP thickness is revealed. Below a NP thickness of 0.4 nm, localization increases toward higher hybridized LSP mode energies. In comparison, above 10 nm thickness, a decrease of localization toward higher mode energies is observed. In the intermediate thickness regime, a transition of the energy dependence of the localization between the two limiting cases, exhibiting a mode energy with minimal localization, is observed. It is shown that this behavior is mainly driven by the energy and thickness dependence of the polarizability of the individual NPs. KW - Gold Nanoparticles KW - Surface plasmons KW - Electron enerdy loss spectroscopy (EELS) KW - scanning transmission electron microscopy PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-647230 DO - https://doi.org/10.1103/44nk-6bp2 SN - 2643-1564 VL - 7 IS - 043053 EP - 4 PB - American Physical Society AN - OPUS4-64723 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Heinrich, Hans-Joachim A1 - Kipphardt, Heinrich T1 - Application of methane as a gaseous modifier for the determination of silicon using electrothermal atomic absorption spectrometry N2 - For determination of silicon in aqueous solutions by electrothermal atomic absorption spectrometry methane/argon mixtures as a gaseous modifier were applied during the pyrolysis step to improve the analytical performance. The beneficial effects observed on thermal stabilization, signal enhancement and shape of absorbance signals were attributed to the thermal decomposition products of methane, which were hydrogen and carbon black (soot). Using a 5% CH4 mixture with argon, the optimized pyrolysis and atomization temperatures were 1350 °C and 2450 °C, respectively. A flushing step following the pyrolysis was mandatory to avoid background absorption and accelerated deposition of pyrolytic graphite. Characteristic masses of 50 and 30 pg were obtained for standard transversely heated graphite atomizer (THGA) tubes and end-capped THGA tubes, respectively, which were lower than with other previously applied modifiers. A limit of detection of 0.2 µg L- 1 (3 s, n = 10) has been obtained. In addition, this gaseous modifier did not contribute to contamination which often was significant when a liquid modifier solution was co-injected. The proposed method has been applied to the determination of silicon in ultrapure water, nitric and hydrochloric acids. KW - Electrothermal atomic absorption KW - Spectrometry KW - Silicon determination KW - Methane KW - Modifier KW - Ultrapure reagents PY - 2012 DO - https://doi.org/10.1016/j.sab.2012.04.001 SN - 0584-8547 SN - 0038-6987 VL - 70 SP - 68 EP - 73 PB - Elsevier B.V. CY - Amsterdam AN - OPUS4-26050 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Heinrich, Sebastian A1 - Edeling, Florian A1 - Liebner, Christian A1 - Hieronymus, Hartmut A1 - Lange, T. A1 - Klemm, E. T1 - Catalyst as ignition source of an explosion inside a microreactor N2 - The present issue reports on a specific aspect of safety engineering of the heterogeneously catalysed oxidation of ethene in a continuous-flow microreactor. Conversion of ethene and the corresponding surface temperature of the catalyst were monitored for different reactor temperatures and total flow rates with a stoichiometric ethene/oxygen mixture for total oxidation. Safe operation of the highly exothermic oxidation was possible, but not in the whole parameter range. At high reactor temperatures and flow rates, ignition of an explosion inside the microreactor caused by a hot spot on the surface of the catalyst was observed for the first time. KW - Catalyst KW - Ethene KW - Explosions KW - Hot spot KW - Microstructure KW - Safety PY - 2012 DO - https://doi.org/10.1016/j.ces.2012.08.049 SN - 0009-2509 VL - 84 SP - 540 EP - 543 PB - Elsevier Ltd. CY - Amsterdam AN - OPUS4-26782 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Häßler, Dustin T1 - Standsicherheit von Einfriedungsmauern N2 - Massive Einfriedungen werden seit Jahr hunderten zur Sicherung und als Sichtschutz von Grundstücken genutzt. Natursteine und künstliche Steine dienen als Baumaterialien. Lose und vermörtelte Bauweisen finden dabei Anwendung. Allgemeine Erfahrungswerte und jahrzehntelanges Vorhandensein der Mauern dienen meist als »Nachweis der Standsicherheit« für die freistehenden Mauern. KW - Standsicherheit KW - Mauerwerk KW - Schäden KW - Ertüchtigung KW - Bauen im Bestand PY - 2012 SN - 2190-4278 VL - 3 IS - 1 SP - 23 EP - 28 PB - Fraunhofer-IRB-Verl. CY - Stuttgart AN - OPUS4-25720 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Hickel, Tilmann A1 - Waske, Anja A1 - Tehranchi, Ali A1 - Bhattacharya, Biswajit A1 - Stawski, Tomasz M. A1 - Fellinger, Tim-Patrick A1 - Mehmood, Asad A1 - Witt, Julia A1 - Ozcan, Ozlem A1 - Guilherme Buzanich, Ana A1 - Kumar, Sourabh A1 - Mishra, Rajesh Kumar A1 - Holzer, Marco A1 - Stucchi de Camargo, Andrea Simone A1 - Agudo Jácome, Leonardo A1 - Manzoni, Anna A1 - Fantin, Andrea A1 - John, Elisabeth A1 - Hodoroaba, Vasile-Dan A1 - Bührig, Sophia A1 - Murugan, Jegatheesan A1 - Marschall, Niklas A1 - George, Janine A1 - Darvishi Kamachali, Reza A1 - Maaß, Robert A1 - Emmerling, Franziska T1 - Chemically complex materials enable sustainable high-performance materials N2 - Chemically complex materials (CCMats) 􀀀 including high-entropy alloys, oxides, and related multi-principal element systems 􀀀 offer a paradigm shift in materials design by leveraging chemical diversity to simultaneously optimize functional, structural, and sustainability criteria. The vastness of the compositional and structural space in CCMats propels the field into an expanding exploratory state. To reconcile functional and structural performance across this immense parameter space remains an open challenge. This Perspective evaluates the opportunities and challenges associated with harnessing chemical complexity across a broad spectrum of applications, such as hydrogen storage, ionic conductors, catalysis, magnetics, dielectrics, semiconductors, optical materials, and multifunctional structural systems. It is delineated how three central design strategies: targeted substitution (SUB), defect engineering (DEF), and diversity management (DIV) enable the reconciliation of high functional performance with long-term structural stability and environmental responsibility. Advances in computational thermodynamics, microstructure simulations, machine learning, and multimodal characterization are accelerating the exploration and optimization of CCMats, while robust data infrastructures and automated synthesis workflows are emerging as essential tools for navigating their complex compositional space. By fostering cross-disciplinary knowledge transfer and embracing data-driven design, CCMats are poised to deliver next-generation materials solutions that address urgent technological, energy, and environmental demands. KW - Chemically complex materials KW - Structural stability KW - Functional performance KW - Design strategies KW - Sustainability PY - 2026 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-655598 UR - https://www.sciencedirect.com/science/article/pii/S1359028626000033?via%3Dihub DO - https://doi.org/10.1016/j.cossms.2026.101256 SN - 1359-0286 VL - 42 SP - 1 EP - 26 PB - Elsevier Ltd. CY - Amsterdam AN - OPUS4-65559 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Harrer, Andrea A1 - Daschewski, Maxim A1 - Prager, Jens A1 - Kreutzbruck, Marc A1 - Guderian, Matthias A1 - Meyer-Plath, Asmus T1 - Thermoacoustic generation of airborne ultrasound using carbon materials at the micro- and nanoscale N2 - The generation of airborne ultrasound is presented using the thermoacoustic principle applied to carbon materials at the micro- and nanoscale. Such materials are shown to be capable of emitting ultrasound when being fed by an alternating current. We tested the acoustic performance of carbon fibers, bucky papers and electrospun polyacrylonitrile-derived carbon nanofibers and determined the sound pressure for frequencies up to 350 kHz. A comparison between the experimental results and the theoretical prediction showed remarkable agreement for frequencies up to 150 kHz. Beyond 150 kHz, we found slight deviations from the expected sound pressure dependence on the square root of the frequency. KW - Thermoacoustic KW - Airborne ultrasound transducer KW - Sound pressure PY - 2012 DO - https://doi.org/10.3233/JAE-2012-1440 SN - 1383-5416 SN - 0925-2096 VL - 39 IS - 1-4 SP - 35 EP - 41 PB - IOS Press CY - Amsterdam, The Netherlands AN - OPUS4-26737 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Gravenkamp, Hauke A1 - Song, C. A1 - Prager, Jens T1 - A numerical approach for the computation of dispersion relations for plate structures using the scaled boundary finite element method N2 - In this paper, a method is presented for the numerical computation of dispersion properties and mode shapes of guided waves in plate structures. The formulation is based on the Scaled Boundary Finite Element Method. The through-thickness direction of the plate is discretized in the finite element sense, while the direction of propagation is described analytically. This leads to a standard eigenvalue problem for the calculation of wave numbers. The proposed method is not limited to homogeneous plates. Multi-layered composites as well as structures with continuously varying material parameters in the direction of thickness can be modeled without essential changes in the formulation. Higher-order elements have been employed for the finite element discretization, leading to excellent convergence for complex structures. It is shown by numerical examples that this method provides highly accurate results with a small number of nodes while avoiding numerical problems and instabilities. KW - Scaled boundary finite element method KW - Lamb waves KW - Dispersion KW - Non-destructive testing KW - Composites KW - Functionally graded materials PY - 2012 DO - https://doi.org/10.1016/j.jsv.2012.01.029 SN - 0022-460X SN - 1095-8568 VL - 331 IS - 11 SP - 2543 EP - 2557 PB - Academic Press CY - London AN - OPUS4-25743 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Gravenkamp, Hauke A1 - Prager, Jens A1 - Saputra, A. A. A1 - Song, C. T1 - The simulation of Lamb waves in a cracked plate using the scaled boundary finite element method N2 - The scaled boundary finite element method is applied to the simulation of Lamb waves for ultrasonic testing applications. With this method, the general elastodynamic problem is solved, while only the boundary of the domain under consideration has to be discretized. The reflection of the fundamental Lamb wave modes from cracks of different geometry in a steel plate is modeled. A test problem is compared with commercial finite element software, showing the efficiency and convergence of the scaled boundary finite element method. A special formulation of this method is utilized to calculate dispersion relations for plate structures. For the discretization of the boundary, higher-order elements are employed to improve the efficiency of the simulations. The simplicity of mesh generation of a cracked plate for a scaled boundary finite element analysis is illustrated. KW - Lamb waves KW - Scaled boundary finite element method KW - Dispersion KW - Structural dynamics KW - Cracks PY - 2012 DO - https://doi.org/10.1121/1.4740478 SN - 0001-4966 SN - 1520-8524 VL - 132 IS - 3 SP - 1358 EP - 1367 PB - AIP CY - Melville, NY, USA AN - OPUS4-27115 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Hanelt, Sven A1 - Friedrich, Jörg Florian A1 - Orts Gil, Guillermo A1 - Meyer-Plath, Asmus T1 - Study of Lewis acid catalyzed chemical bromination and bromoalkylation of multi-walled carbon nanotubes N2 - Chemical functionalization of carbon nanotubes (CNT) with nucleophiles requires introduction of electrophilic reactive sites on the CNTs. This can, for instance, be accomplished by the chemical bromination procedure with elemental bromine and a set of Lewis acids (BBr3, BF3 × Et2O, AlBr3, FeBr3, ZnBr2, TiBr4, SiBr4, SnBr4, VBr3) or a radical starter like dibenzoylperoxide (DBPO) in appropriate solvents at varied temperature. The present approach to electrophilic sites relies on the well-known electrophilic aromatic substitution or addition of bromine with aromatic structural units. In addition to the use of bromine, the introduction of haloalkyl groups was also investigated here using bis-electrophiles or haloalcohols and Brønsted acids. The advantages and drawbacks of the studied reaction conditions, the obtained degree of bromination as analyzed by X-ray photoelectron spectroscopy (XPS) and the amount of introduced bromine that can be substituted by a nucleophile are presented and discussed. KW - Carbon nanotubes KW - Bromierung KW - Lewis Säure KW - Bromalkylierung KW - CNT PY - 2012 DO - https://doi.org/10.1016/j.carbon.2011.11.009 SN - 0008-6223 SN - 1873-3891 VL - 50 IS - 3 SP - 1373 EP - 1385 PB - Pergamon Press CY - New York, NY AN - OPUS4-25207 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Gründer, Klaus-Peter A1 - Menrad, Andreas A1 - Kadoke, Daniel T1 - Bestimmung des Verformungsverhaltens vorgeschädigter Gefahrgutumschließungen aus Kunststoff N2 - Verpackungen für gefährliche Güter werden je nach Zweckbestimmung, Anwendungsbereich bzw. dem Grad der Gefährdung aus sehr unterschiedlichen Werkstoffen hergestellt. Für gefährliche Flüssigkeiten sind u.a. Verpackungen aus Kunststoff (Kanister) vorgesehen. Für deren Zulassung als Transport- oder Lagerbehälter sind verschiedene experimentelle Prüfungen erforderlich. Die Innendruckprüfung (hydraulisch) ist eine dieser vorgeschriebenen Prüfungen. Im Rahmen der vorliegenden Darstellung wurden Untersuchungen an extrusionsblasgeformten Kanistern aus Polyethylen hoher Dichte (HDPE) verschiedener Typen durchgeführt. Ziel der Arbeiten ist es, einen Eignungsnachweis bezüglich Behälterkonstruktion, Werkstoffeigenschaften und Einsatzbedingungen im Sinne einer sicherheitstechnischen Bauartzulassung zu führen. Ein Schwerpunkt war desweiteren die Untersuchung des Einflusses unterschiedlich schädigender Flüssigkeiten auf die mechanischen Eigenschaften des HDPE-Werkstoffes. In Experimenten zum Nachweis der Behältersicherheit verwendet man stellvertretend für die Originalflüssigkeiten sogenannte Standardflüssigkeiten. Diese sind durchaus gefährlicher als die Originalflüssigkeiten, ersparen aber für Prüfzwecke die Bevorratung einer großen Anzahl der unterschiedlichen Originalflüssigkeiten und deren Transport zum Ort der Prüfung. Mit Standardflüssigkeiten werden die erforderlichen Einwirkzeiten auf den Kunststoff von 6 Monaten bei 23 °C auf 3 Wochen unter 40 °C verkürzt. Standardflüssigkeiten sind Netzmittellösung, Essigsäure, Salpetersäure, Kohlenwasserstoffgemisch (White Spirit) und Butylacetat. Die mit unterschiedlichen Standardflüssigkeiten vorgeschädigten Kunststoffbehälter wurden anschließend der Innendruckprüfung ausgesetzt. Das Hauptaugenmerk der vorliegenden Abhandlung konzentriert sich als Teilaspekt im Rahmen unmfangreicher Materialuntersuchungen von Kunststoffumschließungen auf die experimentelle Form- und Verformungsanalyse der Kanister mittels optischer 3D-Verfahren. Diese ist insbesondere für den Vergleich mit den FE-Simulationsergebnissen und zwischen verschiedenen Wekstoffen von Interesse. Die Werkstoffe haben ein unterschiedliches Schwell- und Auslängungsverhalten. Es ist wichtig zu wissen, ob es trotz unterschiedlicher Wanddickensteuerungen oder gerade mit diesen möglich ist, eine 'ähnliche' Produktgestalt zu ermöglichen. T2 - 16. GMA/ITG-Fachtagung 'Sensoren und Messsysteme' CY - Nürnberg, Germany DA - 22.05.2012 KW - Gefahrgutumschließung KW - Kunststoff KW - Verformungsanalyse KW - Optische 3D-Verfahren PY - 2012 SN - 978-3-9813484-0-8 DO - https://doi.org/10.5162/sensoren2012/P2.1 SP - 722 EP - 729 CY - Wunstorf AN - OPUS4-27378 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Bijeljic, Jelena A1 - Niederleithinger, Ernst T1 - Concrete performance assessment based on gas permeability testing N2 - Designing of structures with medium to high performance requirements is a demanding and challenging engineering task. Depending on the location and type of the planned structure, various pre-testing methods should be applied. In recent decades, there has been a focus on the durability of concrete. Concrete is a porous material with a relatively thin protective cover layer, making it vulnerable to the penetration of external agents such as carbon dioxide. Gas permeability testing (kT), a relatively new non-destructive method (NDT), should therefore be considered. This paper presents results of gas permeability testing on a set of larger concrete samples made under controlled conditions with some paroperty variations order to find initial kT parameters important for quality assurance. KW - Concrete KW - Permeability KW - Durability KW - Torrent Tester PY - 2025 DO - https://doi.org/10.62683/ZRGAF41.2 SN - 3009-4674 VL - 41 IS - 1 SP - 15 EP - 23 PB - Faculty of Civil Engineering and Architecture, University of Nis AN - OPUS4-65715 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Günzel, Stephan A1 - Hickmann, Stefan A1 - Wittemeyer, Christian A1 - Trappe, Volker T1 - Effects of fiber orientation and moisture on the crack growth in short glass fiber reinforced polyamide N2 - Short glass fiber reinforced polyamides are increasingly used in automotive applications. Concepts and models are needed, which enable the prediction of the structural durability. The fiber orientation and the content of moisture have a major influence on the fracture mechanical properties and on the damage mechanisms. The complex crack growth behavior was investigated and described in an empirical model. PY - 2012 DO - https://doi.org/10.1002/adem.201100337 SN - 1438-1656 VL - 14 IS - 10 SP - 867 EP - 872 PB - Wiley-VCH Verl. CY - Weinheim AN - OPUS4-26938 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Henning, Thorsten A1 - Goerdeler, Cornelius A1 - El-Khatib, Ahmed H. A1 - Meyer, Klas A1 - Bruer, Gustav G. A1 - Abraham, Klaus A1 - Monien, Bernhard T1 - Characterization and quantitation of urinary metabolites of 3-monochloropropane-1,2-diol (3-MCPD) in rats N2 - Fatty acid esters of 3-monochloropropane-1,2-diol (3-MCPD) are heat-induced contaminants formed from fats and sodium chloride. The mode of action for the 3-MCPD mediated induction of renal tubule neoplasms in rats is still unclear, which is in part due to lacking metabolism data. In the current study, urinary metabolites were identified by one- and two-dimensional 13C nuclear magnetic resonance spectroscopy and high-resolution mass spectrometry following oral administration of 3-MCPD or [13C3]3-MCPD in rats. In addition to 3-MCPD itself, nine metabolites were identified. Four of those, N-acetyl-S-(2,3-dihydroxypropyl)cysteine (DHPMA), 3-MCPD sulfate, β-chlorolactic acid (β-ClLA) and oxalic acid have been reported before. Five novel metabolites in rat urine were thiodiglycolic acid (TDGA), thionyldiglycolic acid (TNDGA), 3-MCPD glucuronide (at least three isomers), 3-carboxy-2-hydroxypropyl mercapturic acid (CHPMA), and 3-(S-carboxymethyl)mercaptolactic acid (CMMLA). Only three metabolites were excreted at mean dose ratios > 1% (after treatment with 50 mg 3-MCPD/kg body weight in male and female rats), i.e. 3-MCPD (7.3%, 9.7%), DHPMA (3.5%, 1.7%) and TDGA (1.1%, 4.0%). The overall mean dose excretion in urine samples (males: 12.2%, females: 16.3%) supported hypotheses on formation of conjugates/adducts of reactive metabolites and the possibility that dechlorination leads to suitable building blocks for amino acid and fatty acid synthesis. The identification of TDGA indicated the interim formation 2-chloroacetaldehyde, previously identified to mediate specific nephrotoxic effects of the cytostatic ifosfamide in rats. KW - 3-Monochloropropane-1,2-diol KW - 3-MCPD KW - Metabolism KW - Urine PY - 2026 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-657230 DO - https://doi.org/10.1007/s00204-026-04318-x SP - 1 EP - 17 PB - Springer-Verlag GmbH CY - Heidelberg AN - OPUS4-65723 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -