TY - INPR A1 - Nowak, S. H. A1 - Petric, M. A1 - Buchriegler, J. A1 - Bjeoumikhov, A. A1 - Bjeoumikhova, Z. A1 - von Borany, J. A1 - Munnik, F. A1 - Radtke, Martin A1 - Renno, A. D. A1 - Reinholz, Uwe A1 - Scharf, O. A1 - Tilgner, J. A1 - Wedell, R. T1 - Road to micron resolution with a color X-ray camera - Polycapillary optics characterization N2 - In a color X-ray camera spatial resolution is achieved by means of a polycapillary optic conducting X-ray photons from small regions on a sample to distinct energy dispersive pixels on a CCD matrix. At present, the resolution limit of color X-ray camera systems can go down to several microns and is mainly restricted by Pixel dimensions. The recent development of an efficient subpixel resolution algorithm allows a release from pixel size, limiting the resolution only to the quality of theoptics. In this work polycapillary properties that influence the spatial resolution are systematized and assessed both theoretically and experimentally. It is demonstrated that with the current technological Level reaching one micron resolution is challenging, but possible. KW - Color X-ray camera KW - Polycapillary optics PY - 2017 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-404404 DO - https://doi.org/10.48550/arXiv.1705.08939 SN - 2331-8422 SP - 1 EP - 11 PB - Cornell University CY - Ithaca, NY AN - OPUS4-40440 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Steglich, Patrick A1 - Paul, Martin A1 - Mai, C. A1 - Böhme, A. A1 - Bondarenko, S. A1 - Weller, Michael G. A1 - Mai, A. T1 - A monolithically integrated microfluidic channel in a silicon-based photonic-integrated-circuit technology for biochemical sensing N2 - In this work, a cost-effective optofluidic system is proposed and preliminary experimental results are presented. A microfluidic channel monolithically integrated into a photonic integrated circuit technology is used in conjunction with a cyclic olefin copolymer (COC) substrate to provide fluidic in- and output ports. We report on initial experimental results as well as on the simple and cost-effective fabrication of this optofluidic system by means of micro-milling. KW - Biosensors KW - Biophotonics KW - Optical sensors KW - Photonic sensors KW - Ring resonators KW - Silicon photonics KW - Lab-on-a-chip KW - Microfluidics KW - Chip KW - Biochip PY - 2021 DO - https://doi.org/10.1117/12.2588791 VL - 11772 SP - 1 EP - 5 PB - SPIE AN - OPUS4-53559 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Gabitov, R.I. A1 - Schmitt, A.K. A1 - Rosner, Martin A1 - McKeegan, K.D. A1 - Gaetani, G.A. A1 - Cohen, A.L. A1 - Watson, E.B. A1 - Harrison, T.M. T1 - In situ delta7Li, Li/Ca, and Mg/Ca analyses of synthetic aragonites N2 - In situ secondary ion mass spectrometry (SIMS) analyses of δ7Li, Li/Ca, and Mg/Ca were performed on five synthetic aragonite samples precipitated from seawater at 25°C at different rates. The compositions of δ7Li in bulk aragonites and experimental fluids were measured by multicollector inductively coupled plasma–mass spectrometry (MC-ICP-MS). Both techniques yielded similar δ7Li in aragonite when SIMS analyses were corrected to calcium carbonate reference materials. Fractionation factors α7Li/6Li range from 0.9895 to 0.9923, which translates to a fractionation between aragonite and fluid from -10.5‰ to -7.7‰. The within-sample δ7Li range determined by SIMS is up to 27‰, exceeding the difference between bulk δ7Li analyses of different aragonite precipitates. Moreover, the centers of aragonite hemispherical bundles (spherulites) are enriched in Li/Ca and Mg/Ca relative to spherulite fibers by up to factors of 2 and 8, respectively. The Li/Ca and Mg/Ca ratios of spherulite fibers increase with aragonite precipitation rate. These results suggest that precipitation rate is a potentially important consideration when using Li isotopes and elemental ratios in natural carbonates as a proxy for seawater composition and temperature. KW - Lithium KW - Isotope KW - Aragonite KW - Rate KW - SIMS KW - Magnesium PY - 2011 DO - https://doi.org/10.1029/2010GC003322 SN - 1525-2027 VL - 12 IS - 3 (Technical Brief) SP - 1 EP - 16 CY - Washington, DC, USA AN - OPUS4-23312 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Chan, George C.-Y. A1 - Hieftje, Gary M. A1 - Omenetto, Nicoló A1 - Axner, Ove A1 - Bengtson, Arne A1 - Bings, Nicolas H. A1 - Blades, Michael W. A1 - Bogaerts, Annemie A1 - Bolshov, Mikhail A. A1 - Broekaert, José A.C. A1 - Chan, WingTat A1 - Costa-Fernández, José M. A1 - Crouch, Stanley R. A1 - De Giacomo, Alessandro A1 - D’Ulivo, Alessandro A1 - Engelhard, Carsten A1 - Falk, Heinz A1 - Farnsworth, Paul B. A1 - Florek, Stefan A1 - Gamez, Gerardo A1 - Gornushkin, Igor B. A1 - Günther, Detlef A1 - Hahn, David W. A1 - Hang, Wei A1 - Hoffmann, Volker A1 - Jakubowski, Norbert A1 - Karanassios, Vassili A1 - Koppenaal, David W. A1 - Kenneth Marcus, R. A1 - Noll, Reinhard A1 - Olesik, John W. A1 - Palleschi, Vincenzo A1 - Panne, Ulrich A1 - Pisonero, Jorge A1 - Ray, Steven J. A1 - Resano, Martín A1 - Russo, Richard E. A1 - Scheeline, Alexander A1 - Smith, Benjamin W. A1 - Sturgeon, Ralph E. A1 - Todolí, José-Luis A1 - Tognoni, Elisabetta A1 - Vanhaecke, Frank A1 - Webb, Michael R. A1 - Winefordner, James D. A1 - Yang, Lu A1 - Yu, Jin A1 - Zhang, Zhanxia T1 - Landmark Publications in Analytical Atomic Spectrometry: Fundamentals and Instrumentation Development N2 - The almost-two-centuries history of spectrochemical analysis has generated a body of literature so vast that it has become nearly intractable for experts, much less for those wishing to enter the field. Authoritative, focused reviews help to address this problem but become so granular that the overall directions of the field are lost. This broader perspective can be provided partially by general overviews but then the thinking, experimental details, theoretical underpinnings and instrumental innovations of the original work must be sacrificed. In the present compilation, this dilemma is overcome by assembling the most impactful publications in the area of analytical atomic spectrometry. Each entry was proposed by at least one current expert in the field and supported by a narrative that justifies its inclusion. The entries were then assembled into a coherent sequence and returned to contributors for a round-robin review. KW - Analytical atomic spectrometry KW - Spectroscopy KW - Instrumental analysis PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-621588 DO - https://doi.org/10.1177/00037028241263567 SN - 1943-3530 VL - 78 SP - 1 EP - 456 PB - Sage CY - London AN - OPUS4-62158 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Williams, S. H. A1 - Hilger, A. A1 - Kardjilov, N. A1 - Manke, I. A1 - Strobl, M. A1 - Douissard, P.A. A1 - Martin, T. A1 - Riesemeier, Heinrich A1 - Banhart, J. T1 - Detection system for microimaging with neutrons N2 - A new high-resolution detector setup for neutron imaging has been developed based on infinity-corrected optics with high light collection, combined with customized mounting hardware. The system can easily be installed, handled and fitted to any existing facility, avoiding the necessity of complex optical systems or further improved electronics (CCD). This is the first time optical magnification higher than 1:1 has been used with scintillator-based neutron detectors, as well as the first implementation of infinity corrected optics for neutron imaging, achieving the smallest yet reported effective pixel size of 3.375 µm. A novel transparent crystal scintillator (GGG crystal) has been implemented with neutrons for the first time to overcome limitations of traditional powder scintillators (Li6/ZnS, Gadox). The standardized procedure for resolution measurements with the Modulation Transfer Function (MTF) is summarized to facilitate comparison between instruments and facilities. Using this new detector setup, a resolution of 14.8 µm with a field of view of 6 mm × 6 mm has been achieved while maintaining reasonable count times. These advances open a wide range of new possible research applications and allow the potential for additional future developments. KW - Instrumentation for neutron sources KW - Neutron radiography KW - Neutron detectors (cold, thermal, fast neutrons) PY - 2012 DO - https://doi.org/10.1088/1748-0221/7/02/P02014 SN - 1748-0221 VL - 7 IS - P02014 SP - 1 EP - 26 PB - Inst. of Physics Publ. CY - London AN - OPUS4-26433 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Fittschen, U.E.A. A1 - Möckel, R. A1 - Schreiner, M. A1 - klinger, M. A1 - Radtke, Martin A1 - Meyer, B. A1 - Guhl, S. A1 - Renno, A. A1 - Godinho, J. A1 - Gloaguen, R. A1 - Gutzmer, J. T1 - Bundling analytical capacities to understand phase formation in recycling of functional materials N2 - Transitioning from combustion engine-driven transportation to e-mobility demands a paradigm shift – from a system geared to maximize energy efficiency (i.e. fuel consumption) to a system that may be constrained by the availability of high technology (critical) metals required for electrical energy storage systems and drives. In the wake of these developments efforts in securing new resources of these metals from recycling of end-of-life products are increasing steadily. Recycling of Li-Ion batteries has recently been evaluated. The results pinpoint to a critical need for understanding slag Formation and its dependence on metal components like Mn under extreme conditions. This will allow researchers to predict optimal Operation setting and to react quickly to changing market demands (which may be Li or Co at one point but may also shift to Ni or rare earth elements (REE)). The long-term goal is to control the formation of specific phases in slags allowing for a Maximum yield of elements of interest and optimal recovery in the separation processes that follows. The combination of data on the physical micro structure and local chemistry of the multi-Phase products during and after processing will help to understand and derive thermodynamic and kinetic data on its formation. In this paper we are giving an overview on the analytical challenges and approaches to provide robust data on local element concentration and species (especially Mn which is a common component of next generation Li-ion batteries cathodes), spanning the dimensions from the nanometer scale to the bulk material. The complementary interactions of X-rays and electrons make them ideal probes to collect Interface and “in-depth” information. Before- and -after studies as well as in situ structural changes and Phase (trans)formation, changes in elemental and elemental species (e.g. oxidation state) distribution may be tracked by X-ray diffraction (XRD), X-ray fluorescence microscopy and X-ray Absorption spectroscopy. The application of such advanced analytical tools will not only provide essential clues during early lab-based experiments towards the development of new recycling technologies, but may also be deployed for on-line and in-line monitoring of industrial processes. KW - Synchrotron KW - XANES KW - Slags KW - Battery PY - 2019 DO - https://doi.org/10.4028/www.scientific.net/MSF.959.183 SN - 1662-9752 VL - 959 SP - 183 EP - 190 PB - Trans Tech Publ. AN - OPUS4-48900 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Nowak, S.H. A1 - Bjeoumikhov, A. A1 - Von Borany, J. A1 - Buchriegler, J. A1 - Munnik, F. A1 - Petric, M. A1 - Renno, A.D. A1 - Radtke, Martin A1 - Reinholz, Uwe A1 - Scharf, O. A1 - Strüder, L. A1 - Wedell, R. A1 - Ziegenrücker, R. T1 - Examples of XRF and PIXE imaging with few microns resolution using SLcam® a color X-ray camera N2 - We present results of recent development of the color X-ray camera, type SLcam®, allowing detection of X-ray images with few microns resolution. Such spectral resolution is achieved with the use of high-quality polycapillary optics combined with sub-pixel resolution. Imaging of Siemens star resolution test chart reveals that the resolution limit of SLcam® can go down to nearly 5µm. Several real sample examples of measurements carried out at the laboratory, synchrotron, and particle-induced X-ray emission beamlines are shown. This is the first time SLcam® is used as particle-induced X-ray emission detector. KW - X-ray KW - Color X-ray camera KW - CXC KW - Synchrotron radiation KW - BESSY KW - BAMline PY - 2015 DO - https://doi.org/10.1002/xrs.2590 SN - 0049-8246 VL - 44 IS - 3 SP - 135 EP - 140 PB - Wiley & Sons, Ltd. CY - Chichester AN - OPUS4-33170 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Nowak, S.H. A1 - Bjeoumikhov, A. A1 - Von Borany, J. A1 - Buchriegler, J. A1 - Munnik, F. A1 - Petric, M. A1 - Radtke, Martin A1 - Renno, A.D. A1 - Reinholz, Uwe A1 - Scharf, O. A1 - Wedell, R. T1 - Sub-pixel resolution with a color X-ray camera N2 - The color X-ray camera SLcam® is a full-field, single photon detector providing scanning-free, energy and spatially resolved X-ray imaging. Spatial resolution is achieved with the use of polycapillary optics guiding X-ray photons from small regions on a sample to distinct energy dispersive pixels on a charged-coupled device detector. Applying sub-pixel resolution, signals from individual capillary channels can be distinguished. Therefore, the SLcam® spatial resolution, which is normally limited to the pixel size of the charge-coupled device, can be improved to the size of individual polycapillary channels. In this work a new approach to a sub-pixel resolution algorithm comprising photon events also from the pixel centers is proposed. The details of the employed numerical method and several sub-pixel resolution examples are presented and discussed. KW - Color X-ray camera KW - Sub pixel analysis PY - 2015 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-334948 DO - https://doi.org/10.1039/c5ja00028a SN - 0267-9477 SN - 1364-5544 SP - 1890 EP - 1897 PB - Royal Society of Chemistry CY - London AN - OPUS4-33494 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Babutzka, Martin A1 - Heyn, A. ED - Lampke, T. ED - Wagner, G. ED - Wagner, M.F.-X. T1 - Korrosionsuntersuchungen mit gelartigen Elektrolyten N2 - Bei elektrochemischen Untersuchungen von atmosphärischen Korrosionsreaktionen an deckschicht- und passivschichtbildenden Werkstoffen stößt man elektrolytseitig an Grenzen. So erweisen sich sowohl das Nachempfinden eines dünnen Feuchtfilms als auch die Interpretation von elektrochemischen Messungen in so genannten Bulk-Lösungen (eine „Masse“ an Elektrolyt) hinsichtlich des Korrosionsverhaltens unter atmosphärischen Bedingungen häufig als schwierig. Eine neue Herangehensweise an diese Problemstellung in der Korrosionsforschung beinhaltet den Einsatz von gelartigen Elektrolyten als Alternative zu den Bulk-Elektrolyten. Gelartige Elektrolyte bilden einen dünnen Feuchtfilm auf der Werkstoffoberfläche aus, wodurch die natürlich gebildete Deckschicht ähnlich wie an Atmosphäre beeinflusst wird und nahezu zerstörungsfrei untersucht werden kann. Durch eine elektrochemische Instrumentierung können geeignete Kennwerte wie Polarisationswiderstände und Korrosionsströme ermittelt werden, die Aussagen zur Kinetik der Deckschichtbildung und zur Stabilität der gebildeten Deckschichten unter Einwirkung eines dünnen Feuchtfilms ermöglichen. Anhand von auf Polysaccharid basierenden Gelpads werden im vorliegenden Beitrag verschiedene Zinkschichtsysteme und Aluminiumlegierungen untersucht, die natürlich gebildeten Deckschichten elektrochemisch charakterisiert und korrosionsrelevante Kennwerte bestimmt. Die ermittelten Kennwerte erlauben eine Differenzierung verschiedener Schichtsysteme und beschreiben die momentane Schutzwirkung der Deckschichten unter atmosphärischen Bedingungen. T2 - 18. Werkstofftechnisches Kolloquium der TU Chemnitz CY - Chemnitz, Germany DA - 10.03.2016 KW - Korrosionsuntersuchungen KW - Corrosion investigations KW - Verzinkungen KW - Zing coatings KW - gelartige Elektrolyte KW - Gel-type electrolytes PY - 2016 SN - 978-3-00-052212-3 SN - 1439-1597 VL - 59 SP - 313 EP - 323 PB - TU Chemnitz, Fakultät für Maschinenbau, Institut für Werkstoffwissenschaft und Werkstofftechnik CY - Chemnitz AN - OPUS4-35637 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wiggenhauser, Herbert A1 - Kind, Thomas A1 - Krause, Martin A1 - Schulze, S. A1 - Taffe, A. A1 - Trela, Christiane A1 - Wöstmann, Jens T1 - Praktische Anwendung zerstörungsfreier Prüfverfahren an Brücken N2 - Die drei Beispiele zerstörungsfreier Prüfungen an Spannbetonbrücken zeigen unterschiedliche Problemstellungen und deren Lösung mit unterschiedlichen Ansätzen. Allen drei Beispielen gemeinsam ist die Verwendung kommerzieller Geräte. Diese werden von verschiedenen Anbietern bereitgestellt. Eine weitere Gemeinsamkeit ist, dass die Grundgeräte durch zusätzliche Maßnahmen ergänzt. Erst dann ist der gewünschte Untersuchungserfolg sicher gestellt. Im ersten Beispiel wurde die vom Auftraggeber geforderte Präzision dadurch erreicht, dass systematische Voruntersuchungen stattfanden. Die Übertragung der Lokalisierung direkt auf die Betonoberfläche stellte sicher, dass keinen Informationsverluste an die nachfolgenden Aufgaben auftraten. Das zweite Beispiel zeigt den Nutzen von Automatisierung und Kombination von Verfahren. Damit können dem Auftraggeber die notwendigen Angaben über Einbauteile mit großer Detaitreue und leicht verständlicher Visualisierung aufbereitet werden. Der abschließende Bericht zeigt, wie vorhandene Auswertungen sinnvoll durch noch in der Forschung befindliche Ansätze bereichert werden. Insgesamt ist die zerstörungsfreie Prüfung in der Lage, an Brücken preisrelevante Fragestellungen zu lösen. Voraussetzung hierfür ist eine sorgfältig geplante Vorgehensweise und ein sicheres Verständnis der Grundlage der eingesetzten Geräte und Auswertungsschritte. T2 - 1. Brückenkolloquium - Beurteilung, Ertüchtigung und Instandsetzung von Brücken CY - Ostfildern/Stuttgart, Germany DA - 24.06.2014 PY - 2014 SP - Paper 00_08, 1 EP - 8 AN - OPUS4-31032 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Krause, Martin A1 - Kurz, J.H. A1 - Lanata, F. A1 - Krstevska, L. A1 - Cavalli, A. T1 - Needs for further developing monitoring- and NDT-methods for timber structures N2 - For the assessmentand for monitoring of timber structures there are numerous promising methods that enable the quantitative description of the current condition of construction elements or parts of a structure. This concerns material properties like modulus of elasticity, moisture content and density as well as structural properties like dynamic characteristics, localization of inhomogeneities, cracks, and biological attack. During the work in COST Action FP 1101, since 2012 the capability of experimental methods are discussed and compared. This covers electrical and electromagnetic wave methods (resistivity, microwave, Radar, X-Ray), elastic waves (ultrasound, pile testing) and mechanical testing (static and dynamic). Describing and collecting the use of the experimental methods for monitoring purposes was the objective of working group 3 "Monitoring of Timber Structures" of the COST Action. Monitoring capabilities will extend the use of timber structures to further applications in civil engineering. So far, no standard exists but collections of application examples and review papers representing the state of the art. From there needs for further developments regarding monitoring and NDT methods for timber structures can be identified and these are described in this paper. T2 - SHATIS 2015 - 3rd International conference on structural health assessment of timber structures CY - Wroclaw, Poland DA - 09.09.2015 KW - Holz Konstruktionen KW - Monitoring KW - Langzeitverhalten KW - Erdbebensicherheit KW - Historische Bauwerke KW - Ultrasonic echo imaging KW - Historical timber structures KW - Seismic investigation KW - Dynamic tests KW - Anisotropic wave propagation KW - Extending service life PY - 2015 VL - 1 SP - 1 EP - 12 AN - OPUS4-35178 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Günther, Martin A1 - Lorenzetti, A. A1 - Schartel, Bernhard T1 - From Cells to Residues: Flame-Retarded Rigid Polyurethane Foams N2 - Rigid polyurethane foams (RPUFs) exhibit short times to ignition as well as rapid flame spread and are therefore considered to be hazardous materials. This paper focuses on the fire phenomena of RPUFs, which were investigated through a multimethodological approach. Water-blown polyurethane (PUR) foams without flame retardants (FRs) as well as waterblown PUR foams containing triethyl phosphate as a gas phase-active FR were examined. The aim of this study is to clarify the influence of the FR on the fire phenomena during combustion of the foams. Additionally, materials’ densitieswere varied to range from 30 to 100 kg/m3. Thermophysical properties were studied bymeans of thermogravimetry; fire behavior and flammability were investigated via cone calorimeter and limiting Oxygen index, respectively. During the cone calorimeter test, the temperature development inside the burning specimens was monitored with thermocouples, and cross sections of quenched specimens were examined visually, giving insight into the morphological changes during combustion. The present paper delivers a comprehensive study, illuminating phenomena occurring during foam combustion and the influence of a FR active in the gas phase. The superior fire performance of flameretarded PUR foams was found to be based on flame inhibition, and on increased char yield leading to a more effective protective layer. It was proven that in-depth absorption of radiation is a significant factor for estimation of time to ignition. Cross sections investigated with the electron scanning microscope exhibited a pyrolysis front with an intact foam structure underneath. The measurement of temperature development inside burning specimens implied a shift of burning behavior towards that of non-cellular materials with rising foam density. KW - Polyurethane KW - Rigid foams KW - Fire behavior PY - 2020 DO - https://doi.org/10.1080/00102202.2019.1634060 SN - 0010-2202 SN - 1563-521X VL - 192 IS - 12 SP - 2209 EP - 2237 PB - Taylor & Francis AN - OPUS4-51483 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Wu, W. A1 - Wei, A. A1 - Huang, W. A1 - Zhao, Peng A1 - Schmidt, Martin A1 - Krause, Ulrich A1 - Wu, Dejian T1 - Experimental and theoretical study on the inhibition effect of CO2/N2 blends on the ignition behavior of carbonaceous dust clouds N2 - Gaseous inhibitors are used in many industries for the explosion prevention of combustible dusts, mitigating the potential hazard to humans, properties and environments. This work experimentally and theoretically studied the inerting effect of gaseous inhibitors on the ignition process of dust clouds in O2/N2/CO2 atmospheres, with an emphasis on the role of the CO2/N2 ratio. 10 different combustible carbonaceous dusts were selected, including grain dust, biomass dust and coal dust. Experimental results showed that the inhibition effect of CO2/N2 is closely related to the ignition mechanism of dust clouds. Specifically, a higher ratio of CO2/N2 yields a stronger inhibition effect on the ignition process of dust samples with relatively low volatile matter contents predominated by heterogeneous ignition. In addition, two novel steady-state ignition mechanism models were developed to interpret the experimental observations. Maxwell-Stefan equations were used to describe the diffusivity in the ternary O2/N2/CO2 gas mixtures. The analytical results were in good agreement with the experimental data of the minimum ignition temperature of dust cloud (MITC) in oxygen-lean atmospheres. The mechanism modelling can be used to estimate the critical ignition temperature of all carbonaceous dust clouds with a wide range of volatile matter content under different inert atmospheres, which will provide a reference for the explosion hazard assessment of dust posed by a hot surface in the process industries. KW - CO2/N2 ratio KW - Inerting effect KW - Volatile matter content KW - MITC KW - Mechanism model PY - 2021 DO - https://doi.org/10.1016/j.psep.2021.07.005 SN - 0957-5820 VL - 153 SP - 1 EP - 10 PB - Elsevier B.V. AN - OPUS4-53662 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Wu, Dejian A1 - Tan, X. A1 - Wei, A. A1 - Duan, Q. A1 - Huang, W. A1 - Schmidt, Martin T1 - Ignition temperature and mechanism of carbonaceous dust clouds: The roles of volatile matter, CH4 addition, O2 mole fraction and diluent gas N2 - Minimum ignition temperature of dust clouds (MITC) was studied experimentally and theoretically in different atmospheres. Three carbonaceous dusts were tested in both air and O2/CO2 atmospheres with CH4 mole fraction from 0 to 2%. Results showed that the ignition risk of the three dusts significantly increases (decrease of MITC by ~100 ℃) with increasing XO2 from 21% to 50%, but significantly decreases replacing N2 in air with CO2. The inhibition effect of CO2 on MITCs could be diminished by increasing XO2 or adding CH4. The addition of small amount of CH4 has different effects on the MITCs of different dust samples, following the opposite order of volatile matter content: anthracite>bituminous coal>starch. Two modified steady-state ignition models, considering the density of mixture gas and dust cloud, XO2 and its diffusivity, were developed to interpret the experimental observations. The analysis revealed that the global heterogeneous ignition model suits well for the hybrid mixtures of anthracite or bituminous coal dusts. In contrast, the proposed global homogeneous ignition model was found to be only valid for the pure starch dust, and the extra CH4 addition could strongly affect the ignition process of starch, particularly in O2/CO2 atmospheres with higher XO2. KW - Dust explosions KW - Gas explosions KW - Minimum ignition temperature KW - Hybrid mixtures PY - 2021 DO - https://doi.org/10.1016/j.jhazmat.2020.124189 SN - 0304-3894 SN - 1873-3336 VL - 405 SP - 1 EP - 10 PB - Elsevier CY - Amsterdam AN - OPUS4-53838 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Vigna, L. A1 - Gottschalk, Martin A1 - Cacocciola, N. A1 - Verna, A. A1 - Marasso, S. L. A1 - Seeger, Stefan A1 - Pirri, C.F. A1 - Cocuzza, M. T1 - Flexible and reusable parylene C mask technology for applications in cascade impactor air quality monitoring systems N2 - The development of traceable new methodologies to quantify elemental air pollutants in particulate matter (PM) supports modernization of methods used in air quality monitoring networks in Europe. In the framework of the EURAMET EMPIR AEROMET II project, the combination of cascade impactor aerosol sampling and total reflection X-ray fluorescence elemental spectroscopy (TXRF) was investigated. This technique requires a traceable calibration based on reference samples. This paper describes a new, simple and effective method to produce such reference samples using flexible, reusable, and low-cost parylene C shadow masks, fabricated by photolithographic steps. These shadow masks can be used to produce reference samples that mimic the Dekati cascade impactor’s deposition patterns by applying as-prepared micro stencils to 30 mm acrylic substrates and evaporating a reference material (Ti) in arrangements of thin circular dots. The highly flexible direct patterning of acrylic discs with reference material, otherwise impossible with conventional photolithography, allows multiple reusing of the same micro stencils. The aspect ratios of the dots could be repeated with an error less than 4 %. A first set of standard reference samples for the 13 stages of the Dekati cascade impactor was produced and preliminary TXRF measurements of the deposited Ti masses were performed. The centricity of the deposition patterns turned out to be an important parameter for the quality of the TXRF results. The parylene mask technology for the production of reference samples turns out to be a promising new approach for the traceable calibration of TXRF spectrometers for the quantification of element concentrations in environmental aerosol samples but, due to its great versatility, it could be used for several other micropatterning applications on conventional and unconventional substrates. KW - AEROMET II KW - Aerosol KW - Parylene C KW - Reference samples KW - Flexible shadow masks KW - Cascade impactor KW - Air quality monitoring KW - Micropatterning KW - Mask fabrication KW - Elemental aerosol analysis KW - TXRF PY - 2022 DO - https://doi.org/10.1016/j.mne.2022.100108 SN - 2590-0072 VL - 14 SP - 1 EP - 19 PB - Elsevier B.V. CY - Amsterdam AN - OPUS4-54252 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -