TY - JOUR A1 - Zemke, F. A1 - Schölch, V. A1 - Bekheet, M.F. A1 - Schmidt, Franziska T1 - Surfactant-assisted sol–gel synthesis of mesoporous bioactive glass microspheres JF - Nanomaterials and energy N2 - Spherical mesoporous bioactive glasses in the silicon dioxide (SiO2)-phosphorus pentoxide (P2O5)–calcium oxide (CaO) system with a high specific surface area of up to 300m2/g and a medium pore radius of 4 nm were synthesized by using a simple one-pot surfactant-assisted sol–gel synthesis method followed by calcination at 500–700°C. The authors were able to control the particle properties by varying synthesis parameters to achieve microscale powders with spherical morphology and a particle size of around 5–10 mm by employing one structure-directing agent. Due to a high Calcium oxide content of 33·6mol% and a phosphorus pentoxide content of 4·0mol%, the powder showed very good bioactivity up to 7 d of immersion in simulated Body fluid. The resulting microspheres are promising materials for a variety of life science applications, as further processing – for example, granulation – is unnecessary. Microspheres can be applied as materials for powder-based additive manufacturing or in stable suspensions for drug release, in bone cements or fillers. KW - bioactive KW - biomaterials KW - bone PY - 2019 DO - https://doi.org/10.1680/jnaen.18.00020 SN - 2045-9831 SN - 2045-984X VL - 8 IS - 2 SP - 126 EP - 134 PB - ICE Publishing CY - London AN - OPUS4-50148 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Unger, Wolfgang A1 - Oran, Umut A1 - Senoner, Mathias A1 - Schmidt, M. T1 - Chemische Charakterisierung von mikro- und nanotechnologischen Bauteilen: Verfahrensentwicklung und Referenzmaterialien T2 - Messtechnik für Mikro- und Nano-Engineering T2 - VDI/VDE-Tagung "Messtechnik für Mikro- und Nano-Engineering" CY - Erlangen, Germany DA - 2006-11-29 KW - Referenzmaterial KW - Mikrofluidik KW - Nanoanalytik PY - 2006 N1 - Serientitel: VDI-Berichte – Series title: VDI-Berichte IS - 1950 SP - 197 EP - 206 PB - VDI-Verl. CY - Düsseldorf AN - OPUS4-14110 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Thomsen-Schmidt, P. A1 - Hasche, K. A1 - Ulm, G. A1 - Herrmann, K. A1 - Krumrey, M. A1 - Ade, G. A1 - Stümpel, J. A1 - Procop, Mathias A1 - Beck, Uwe T1 - Realisation and metrological characterisation of thickness standards below 100 nm T2 - Tagungsband der DVG Jahrestagung 2002 T2 - DVG Jahrestagung 2002 CY - Magdeburg, Germany DA - 2002-06-17 PY - 2002 SP - 1 EP - 9 PB - Deutsche Vakuum-Gesellschaft CY - Kaiserslautern AN - OPUS4-1936 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Strüder, L. A1 - Hartmann, R. A1 - Holl, P. A1 - Ihle, S. A1 - Huth, M. A1 - Schmidt, J. A1 - Tham, Ch. A1 - Kanngießer, B. A1 - Baumann, J. A1 - Renno, A. A1 - Grenzer, J. A1 - Radtke, Martin A1 - Abboud, A. A1 - Pietsch, U. A1 - Soltau, H. T1 - High Speed, High Resolution imaging spectrometers based on pnCCDs for XRF and XRD applications JF - Microscopy and Microanalysis N2 - For many years pnCCDs have been well known as X-ray detectors for spectroscopic imaging in many fields of science: X-Ray Fluorescence analysis (XRF), X-ray Diffraction (XRD) with light sources in large accelerator facilities as well as with laboratory light sources or with X-rays from celestial sources in X-ray astronomy. A brief introduction in GEXRF (Grazing Emission XRF) measurements with a laboratory laser produced plasma source will be given, PIXE (Particle Induced X-ray Emission) measurements and D2XRF (Double Dispersive X-Ray Fluorescence) and Slicing experiments with pnCCDs coupled to polycapillary optics performed at the BESSY synchrotron will be shown. Energy-dispersive Laue diffraction with ultra-hard X-rays for the analysis of defects in metals will conclude the overview of spectroscopic X-ray imaging measurements in the field of structure and dynamics of matter. KW - PnCCD KW - Synchrotron KW - XRF PY - 2016 DO - https://doi.org/10.1017/S1431927616001355 VL - 22 IS - S3 SP - 100 EP - 101 AN - OPUS4-38884 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Sonebi, M. A1 - Khatib, J. A1 - Schmidt, Wolfram ED - Diouri, A. ED - Khachani, N. ED - Alami Talbi, M. ED - Ait Brahim, L. ED - Bahi, L. T1 - Influence of the type of viscosity-modifying admixtures and metakaolin on the rheology of grouts T2 - CMSS 2013 - International congress on materials & structural stability - Building up sustainable materials & constructions (Proceedings) N2 - The Viscosity-modifying admixtures (VMAs) contribute to the control of the rheology of grouts and are used to enhance plastic viscosity, cohesion, stability, and resistance to bleeding of cement-based systems. This paper reports the results of an investigation on the effect of type of VMAs, namely two types of diutan gums and a welan gum and metakaolin (MTK), plus a superplasticiser, on the rheology behaviour of cement grouts. All mixes were made with polycarboxylic superplasticiser at 0.6% and 0.9%. The dosages of VMAs were 0.05%, and 0.10%, with a fixed water-to-binder ratio of 0.40. The investigated fresh properties of the grouts included the mini-slump flow, plate cohesion, and rheology parameters: namely yield value and plastic viscosity. The rheological parameters were obtained using a vane viscometer. Control grouts (with and without superplasticiser and VMA) were also tested and compared to mixes containing VMAs. The results indicated that the incorporation of MTK reduced the fluidity and increased the plate cohesion and yield stress, and plastic viscosity due to the higher surface area of MTK. The diutan gum grouts improved the grout fresh properties and rheology compared to the welan gum grouts. T2 - CMSS 2013 - International congress on materials & structural stability - Building up sustainable materials & constructions CY - Rabat, Morocco DA - 27.11.2013 KW - Viscosity modifying agent KW - Metakaolin KW - Diutan gum KW - Welan gum KW - Rheology PY - 2013 SN - 978-9954-32-689-3 SP - 1 EP - 6 AN - OPUS4-30041 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schneider, M. A1 - Schlingmann, T. A1 - Schmidt, J. A1 - Bettge, Dirk A1 - Hilgenberg, Kai A1 - Binder, M. A1 - Klöden, B. T1 - A Round Robin Test To Investigate The Printing Quality Of PBF LB/M Processed AlSi10Mg N2 - When it comes to higher accuracies, new technologies and real applications in additive manufacturing, there is one topic which cannot be avoided: The material response on the chosen processing parameters and its agreement and correspondence with literature data of the wrought material grade counterpart. In industrial Additive Manufacturing (AM) standards in terms of printing parameters, protection gas atmospheres or powder handling instructions are not obligatory. Therefore, the question must be answered whether the AM process is reproducible and reliable over different printing companies. This was the motivation to realize a round robin test between 8 European printing companies and academic partners. The consortium had printed and tested fatigue and tensile testing bars under plant-specific conditions. A commonly used cast aluminum alloy, AlSi10Mg, was chosen as test material for the PBF-LB/M process. Differences of the results between the partners and the scatter itself were discussed in detail. T2 - World PM2022 CY - Lyon, France DA - 09.10.2022 KW - Additive manufacturing KW - AlSi10Mg KW - Laser powder bed fusion KW - Round robin KW - Reproducibility PY - 2022 AN - OPUS4-56303 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schneider, M. A1 - Schlingmann, T. A1 - Schmidt, J. A1 - Bettge, Dirk A1 - Hilgenberg, Kai A1 - Binder, M. A1 - Klöden, B. T1 - A Round Robin Test To Investigate The Printing Quality Of PBF-LB/M Processed AlSi10Mg T2 - World PM2022 N2 - When it comes to higher accuracies, new technologies and real applications in additive manufacturing, there is one topic which cannot be avoided: The material response on the chosen processing parameters and its agreement and correspondence with literature data of the wrought material grade counterpart. In industrial Additive Manufacturing (AM) standards in terms of printing parameters, protection gas atmospheres or powder handling instructions are not obligatory. Therefore, the question must be answered whether the AM process is reproducible and reliable over different printing companies. This was the motivation to realize a round robin test between 8 European printing companies and academic partners. The consortium had printed and tested fatigue and tensile testing bars under plant-specific conditions. A commonly used cast aluminum alloy, AlSi10Mg, was chosen as test material for the PBF-LB/M process. Differences of the results between the partners and the scatter itself were discussed in detail. T2 - World PM2022 CY - Lyon, France DA - 09.10.2022 KW - Additive manufacturing KW - Round robin KW - Reproducibility KW - Laser powder bed fusion KW - AlSi10Mg PY - 2022 SN - 978-1-899072-54-5 SP - 1 EP - 10 PB - European Powder Metallurgy Association (EPMA) AN - OPUS4-56304 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schmidt, Wolfram A1 - Sonebi, M. A1 - Brouwers, H.J.H. A1 - Kühne, Hans-Carsten A1 - Meng, Birgit ED - Diouri, A. ED - Khachani, N. ED - Alami Talbi, M. ED - Ait Brahim, L. ED - Bahi, L. T1 - Rheology modifying admixtures: The key to innovation in concrete technology - a general overview and implications for Africa T2 - CMSS 2013 - International congress on materials & structural stability - Building up sustainable materials & constructions (Proceedings) N2 - Innovative admixture technology has significantly widened up the ränge of possibilities of concrete engineers. For many decades the water to cement ratio (w/c) was the major influencing factor for the performance of concrete. Due to the need to adjust a consistency, which still allowed reasonable workability, the w/c was typically significantly higher than technologically reasonable. Rheology modifying admixtures Support adjusting the concrete consistency largely independent of the w/c. It was only after the invention of the first superplasticizers that modern concrete technology significantly evolved in terms of flowability, strength, and durability, and only due to the steady evolution of the technology modern innovations, such as Self-Compacting Concrete, Ultra-High-Performance Concrete, or Engineered Cementitious Composites were made possible. Today’s superplasticizers are extremely versatile and can be adjusted to individual technological specifications. However, the other side of the coin of versatility is that cementitious Systems incorporating superplasticizers have become more sensitive against environmental influences, such as the environmental temperature, which may cause unwanted effects or demand for supplementary admixture use such as stabilizing admixtures. Hence, concrete mixture composition with admixtures demands for a high level of expertise and offen there is lack of awareness about the mode of Operation of rheology modifying admixtures among concrete technologists. The paper gives a comprehensive overview about rheology modifying admixtures such as superplasticizers or stabilizing agents, and how they can be used depending upon the application in the most favourable way. Based on experiences with the sub-Saharan African concreting boundary conditions, which exhibit many challenges in terms of environmental boundary conditions and construction site logistics, conclusions are finally drawn, how admixtures can be used in the most beneficial way to improve the concrete casting Situation. T2 - CMSS 2013 - International congress on materials & structural stability - Building up sustainable materials & constructions CY - Rabat, Morocco DA - 27.11.2013 KW - Rheology KW - Superplasticizers KW - Stabilising agents PY - 2013 SN - 978-9954-32-689-3 SP - 1 EP - 6 AN - OPUS4-30040 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Schmidt, Wolfram A1 - Sonebi, M. A1 - Brouwers, H.J.H. A1 - Kühne, Hans-Carsten A1 - Meng, Birgit T1 - Rheology modifying admixtures: The key to innovation in concrete technology - a general overview and implications for Africa JF - Chemistry and Materials Research N2 - Innovative admixture technology has significantly widened up the ränge of possibilities of concrete engineers. For many decades the water to cement ratio (w/c) was the major influencing factor for the performance of concrete. Due to the need to adjust a consistency, which still allowed reasonable workability, the w/c was typically significantly higher than technologically reasonable. Rheology modifying admixtures Support adjusting the concrete consistency largely independent of the w/c. It was only after the invention of the first superplasticizers that modern concrete technology significantly evolved in terms of flowability, strength, and durability, and only due to the steady evolution of the technology modern innovations, such as Self-Compacting Concrete, Ultra-High-Performance Concrete, or Engineered Cementitious Composites were made possible. Today’s superplasticizers are extremely versatile and can be adjusted to individual technologicalspecifications. However, the other side of the coin of versatility is that cementitious Systems incorporating superplasticizers have become more sensitive against environmental influences, such as the environmental temperature, which may cause unwanted effects or demand for supplementary admixture use such as stabilizing admixtures. Hence, concrete mixture composition with admixtures demands for a high level of expertise and offen there is lack of awareness about the mode of Operation of rheology modifying admixtures among concrete technologists. The paper gives a comprehensive overview about rheology modifying admixtures such as superplasticizers or stabilizing agents, and how they can be used depending upon the application in the most favourable way. Based on experiences with the sub-Saharan African concreting boundary conditions, which exhibit many challenges in terms of environmental boundary conditions and construction site logistics, conclusions are finally drawn, how admixtures can be used in the most beneficial way to improve the concrete casting Situation. KW - Rheology KW - Admixtures KW - Concrete KW - Superplasticizers KW - Polycarboxylate ether KW - Viscosity modifying agents PY - 2013 SN - 2224-3224 SN - 2225-0956 VL - 5 SP - 115 EP - 120 PB - International Institute for Conservation of Historic and Artistic Works CY - New York, NY, USA AN - OPUS4-30948 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schmidt, Martin A1 - Gödde, M. A1 - Salg, S. A1 - Erdt, René T1 - Self-ignition Behaviour of Bulk Materials: How Reliable is the Extrapolation of Laboratory Tests? T2 - Chemical Engineering Transactions N2 - The self-ignition behaviour of bulks is usually determined with the aid of isoperibolic or adiabatic hot storage tests; the sample volumes here are typically in the range of approx. 100 cm³ to several litres. The extrapolation to technically relevant volumes holds, however, considerable uncertainties. To reduce these uncertainties, a test stand was set up that allows to investigation sample sizes of up to 1000 dm³. These allow the study of selfignition behavior closer to the conditions that prevail in practice. The suitability (or unsuitability) of the established methods (including dangerous goods classification tests) were to be demonstrated and influencing variables that cannot be measured on a laboratory scale were to be determined. In addition, various analytical methods were used for the determination of reaction kinetic data of solid bulk materials and to predict the self-ignition behaviour of large storages. These are thermal analyses such as differential scanning calorimetry DSC, simultaneous thermal analysis STA as well as microcalorimetry for highprecision measurement of heat flows. Complete test series using all mentioned test methods will be presented for crosslinked polyvinyl-pyrrolidone (PVP) and conclusions regarding the applicability of the extrapolation methods will be discussed. Hot storage tests up to semi-industrial scale and their combination with various thermoanalytical methods allow a much more precise prediction of the self-ignition behaviour of large bulks. A further promising approach to estimate their heat release rates, and hence, the risk of self-ignition under technical conditions, is the use of microcalorimetric methods. T2 - Loss Prevention 2022 CY - Prag, Czechia DA - 05.06.2022 KW - Self-ignition KW - Kinetic data KW - Semi-technical tests KW - Thermoanalytical methods PY - 2022 SN - 978-88-95608-88-4 DO - https://doi.org/10.3303/CET2290049 SN - 2283-9216 VL - 90 SP - 289 EP - 294 PB - AIDIC AN - OPUS4-55079 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -