TY - JOUR A1 - Rauwolf, M. A1 - Turyanskaya, A. A1 - Roschger, A. A1 - Prost, J. A1 - Simon, R. A1 - Scharf, O. A1 - Radtke, Martin A1 - Schoonjans, Tom A1 - de Oliveira Guilherme Buzanich, Ana A1 - Klaushofer, K. A1 - Wobrauschek, P. A1 - Hofstaetter, J. G. A1 - Roschger, P. A1 - Streli, C. T1 - Synchrotron radiation micro X-ray fluorescence spectroscopy of thin structures in bone samples: comparison of confocal and color X-ray camera setups N2 - In the quest for finding the ideal synchrotron-radiation-induced imaging method for the investigation of trace element distributions in human bone samples, experiments were performed using both a scanning confocal synchrotron radiation micro X-ray fluorescence (SR-mXRF) (FLUO beamline at ANKA) setup and a full-field color X-ray camera (BAMline at BESSY-II) setup. As zinc is a trace element of special interest in bone, the setups were optimized for its detection. The setups were compared with respect to count rate, required measurement time and spatial resolution. It was demonstrated that the ideal method depends on the element of interest. Although for Ca (a major constituent of the bone with a low energy of 3.69 keV for its K alpha XRF line) the color X-ray camera provided a higher resolution in the plane, for Zn (a trace element in bone) only the confocal SR-µXRF setup was able to sufficiently image the distribution. KW - Synchrotron KW - BAMline KW - BESSY KW - XRF KW - X-ray Color Camera PY - 2017 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-391944 DO - https://doi.org/10.1107/S1600577516017057 SN - 1600-5775 VL - 24 SP - 307 EP - 311 PB - International Union of Crystallography AN - OPUS4-39194 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Rudić, O. A1 - Mittermayr, F. A1 - Gluth, Gregor A1 - Simon, Sebastian A1 - Ukrainczyk, N. A1 - Seyrek, Y. A1 - Freytag, B. A1 - Juhart, J. A1 - Grengg, C. T1 - On the benefits of vegetable oil addition for the pore structure and acid resistance of alkali-activated systems N2 - The impact of high additions of vegetable oil (12 vol%) on the mechanical and microstructural properties of metakaolin-slag-based alkali-activated materials (AAMs) was studied. The addition of oil resulted in a slight decrease in initial polymerization kinetics but did not affect the final degree of reaction. AAM-oil-composite-mortars exhibited approximately ∼30% lower compressive strength primarily due to the entrainment of air voids. Newly formed soap phases significantly reduced the volume of small capillary and gel pores (pore radii <15 nm), leading to a decrease in specific inner surface area by a factor of up to 15. The porosity modification induced by the oil addition greatly enhanced the resistance of AAMs against sulfuric acid attack, shifting the dominant processes from diffusion and cracks to framework-dissolution controlled by the inherent phase stabilities. Following the immersion in sulfuric acid (pHstat = 2) for 8 weeks, the depth of corroded layer decreased by 70% and no cracks due to expansive phases were observed. These promising findings suggest that the incorporation of vegetable oil in AAMs has the potential to address durability concerns associated with diffusion-based corrosion processes, thereby expanding the range of future applications. KW - Alkali-activated materials KW - Acid resistance KW - Pore structure PY - 2023 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-581719 DO - https://doi.org/10.1016/j.ceramint.2023.08.036 VL - 49 IS - 20 SP - 33275 EP - 33290 PB - Elsevier Ltd. AN - OPUS4-58171 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Gant, Simon A1 - Chang, Joseph A1 - Hetherington, Rory A1 - Hanna, Steven A1 - Tickle, Gemma A1 - Spicer, Tom A1 - McMasters, Sun A1 - Fox, Shannon A1 - Meris, Ron A1 - Bradley, Scott A1 - Miner, Sean A1 - King, Matthew A1 - Simpson, Steven A1 - Mazzola, Thomas A1 - McGillivray, Alison A1 - Tucker, Harvey A1 - Björnham, Oscar A1 - Carissimo, Bertrand A1 - Fabbri, Luciano A1 - Wood, Maureen A1 - Habib, Abdel Karim A1 - Harper, Mike A1 - Hart, Frank A1 - Vik, Thomas A1 - Helgeland, Anders A1 - Howard, Joel A1 - Mauri, Lorenzo A1 - Mackie, Shona A1 - Mack, Andreas A1 - Lacome, Jean-Marc A1 - Puttick, Stephen A1 - Ibrahim, Adeel A1 - Miller, Derek A1 - Dharmavaram, Seshu A1 - Shen, Amy A1 - Cunningham, Alyssa A1 - Beverly, Desiree A1 - O’Neal, Daniel M. A1 - Verdier, Laurent A1 - Burkhart, Stéphane A1 - Dixon, Chris A1 - Nilsen, Sandra A1 - Bradley, Robert A1 - Skarsvåg, Hans L. A1 - Fyhn, Eirik H. A1 - Aasen, Ailo T1 - Pressure-Liquefied Ammonia Jet Dispersion: Multi-Model Intercomparison Using Desert Tortoise and FLADIS Field Data N2 - This paper presents the findings of an international model inter-comparison exercise that was undertaken in the period 2021-2024 to assess the performance of atmospheric dispersion models for simulating releases of pressure-liquefied ammonia. The exercise used data from ammonia field trials dating from the 1980s and 1990s: the Desert Tortoise and the FLADIS trials. Concentration data from two arcs of sensors in the Desert Tortoise trials and three arcs of sensors in the FLADIS trials were used. Twenty-one independent modelling teams from North America and Europe participated in the exercise and provided in total twenty-seven sets of results from a range of different models, including empirically-based nomograms, integral, Gaussian puff, Lagrangian particle, and Computational Fluid Dynamics (CFD) models. The work is novel in presenting the results from such a large cohort of models, examining specifically the dispersion behaviour of ammonia. This is particularly relevant at the current time, given the growing international interest in using ammonia as a clean energy vector and shipping fuel. The study found that the agreement between model predictions and measurements (as determined by performance measures such as geometric mean bias and geometric variance) varied between different models. At any downwind distance, the range in predicted plume arc-max concentrations spanned a range of up to one or two orders of magnitude about the measurements. Several modelling teams used the same models and, in most cases, their predictions differed. Given appropriate inputs, most models generally predicted concentrations that agreed with the data within commonly-used model acceptance criteria. There was no single class of model that provided superior predictions to others; predictions from several empirically-based nomograms, integral, Gaussian puff, Lagrangian particle, and CFD models were all in close agreement with the data (as defined by the model acceptance criteria). The findings of the exercise are being used to help plan a programme of future ammonia experiments in the USA, called the Jack Rabbit III trials. The results are also useful for assessing the performance of models that may be applied to assess risks at ammonia facilities, and for emergency planning and response. KW - Ammonia KW - Atmospheric dispersion KW - Validation KW - Jack rabbit PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-646069 DO - https://doi.org/10.1016/j.aeaoa.2025.100389 SN - 2590-1621 VL - 28 SP - 1 EP - 76 PB - Elsevier Ltd. AN - OPUS4-64606 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -