TY - JOUR A1 - Silvestro, L. A1 - Ruviaro, A. S. A1 - Lima, G. A1 - Durlo Tambara, Luis Urbano A1 - Feys, D. A1 - Kirchheim, A. P. T1 - Rotational rheometry test of Portland cement-based materials - A systematic literature review N2 - This study systematically reviews 62 papers on the use of rotational rheometry to assess the fresh state behavior of Portland cement-based materials. The research highlights the wide variation in test methods and aims to provide a comprehensive overview. Findings reveal that 50.0% of studies employed vane geometry, despite its limitations in providing transformation equations. Regarding dynamic shearing tests, 67.0% followed a consensus using a pre-shearing step and a step-wise routine with stabilization times ≥ 10 s. While the Bingham model is commonly used, the study emphasizes the importance of considering shear-thinning behavior in cementitious materials. Models like Herschel-Bulkley and modified Bingham may be more appropriate. This review offers insights into testing conditions for rotational rheometry of cementitious materials, serving as a foundation for future research in the field. KW - Review KW - Rheology KW - Rheometry KW - Rotational KW - Cement PY - 2024 U6 - https://doi.org/10.1016/j.conbuildmat.2024.136667 SN - 0950-0618 VL - 432 SP - 1 EP - 14 PB - Elsevier Ltd. CY - Amsterdam AN - OPUS4-60075 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Walke, D. A1 - Micheel, D. A1 - Schallert, K. A1 - Muth, Thilo A1 - Broneske, D. A1 - Saake, G. A1 - Heyer, R. T1 - The importance of graph databases and graph learning for clinical applications N2 - The increasing amount and complexity of clinical data require an appropriate way of storing and analyzing those data. Traditional approaches use a tabular structure (relational databases) for storing data and thereby complicate storing and retrieving interlinked data from the clinical domain. Graph databases provide a great solution for this by storing data in a graph as nodes (vertices) that are connected by edges (links). The underlying graph structure can be used for the subsequent data analysis (graph learning). Graph learning consists of two parts: graph representation learning and graph analytics. Graph representation learning aims to reduce high-dimensional input graphs to low-dimensional representations. Then, graph analytics uses the obtained representations for analytical tasks like visualization, classification, link prediction and clustering which can be used to solve domain-specific problems. In this survey, we review current state-of-the-art graph database management systems, graph learning algorithms and a variety of graph applications in the clinical domain. Furthermore, we provide a comprehensive use case for a clearer understanding of complex graph learning algorithms. KW - Graph databases KW - Graph learning KW - Review KW - RDF PY - 2023 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:b43-580858 SN - 1758-0463 SP - 1 EP - 20 AN - OPUS4-58085 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Rhode, Michael T1 - Fügetechnik in Wasserstofftechnologien: Erzeugung, Transport, Speicherung, Nutzung N2 - Der Vortrag gibt einen kurzen Überblick über die Bedeutung der Fügetechnik in Wasserstofftechnologien und über zukünftige FuE-Bereiche. Fügetechnologien haben dabei wesentliche Bedeutung für die Umsetzung von technischen Komponenten der Wasserstofftechnologien. Forschungsschwerpunkte ergeben sich insbesondere für die Erzeugung und den Transport des Wasserstoffs. T2 - Vortragsreihe des DVS Bezirksverbandes Berlin CY - Berlin, Germany DA - 22.02.2023 KW - Wasserstoff KW - Fügetechnik KW - Forschung KW - Review PY - 2023 AN - OPUS4-57040 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Rhode, Michael A1 - Kannengießer, Thomas T1 - Joining processes for components in hydrogen technologies: Current need and future importance N2 - This presentation gives an overview on the importance of joining processes for component fabrication in hydrogen technologies. For that reason, the current need and future research and developement activites are highlighted for the three technological fields: hydrogen storage, transport and use (in terms of the emerging field of additive manufacturing). Finally, some remarks are given for necessary changes in the standardization. T2 - IIW Intermediate Meeting, Comm. II-A "Welding Metallurgy" CY - Online meeting DA - 17.03.2022 KW - Hydrogen KW - Welding KW - Research KW - Review KW - Additive manufacturing PY - 2022 AN - OPUS4-54488 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Rhode, Michael A1 - Kannengießer, Thomas T1 - Joining Processes in Hydrogen Technologies - Current need and future R&D activites, a review N2 - This study gives an overview on the important field of joining processes for component fabrication in hydrogen technologies. For that reason, the current need and future research and developement activites are highlighted for the different technological field of hydrogen generation, storage, transport and use. In addition, the emerging field of additive manufacturing is included. Finally, some remarks are given for necessary changes in the standardization and its challenges. T2 - 46th Seminar - Additive Manufacturing, Hydrogen, Energy, Integrity CY - Online meeting DA - 12.10.2021 KW - Hydrogen KW - Joining process KW - Welding KW - Review KW - Research and Development PY - 2021 AN - OPUS4-53554 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Rhode, Michael A1 - Richter, Tim A1 - Schröpfer, Dirk A1 - Manzoni, Anna Maria A1 - Schneider, M. A1 - Laplanche, G. T1 - Welding of high-entropy alloys and compositionally complex alloys - an overview N2 - High-entropy alloys (HEAs) and compositionally complex alloys (CCAs) represent new classes of materials containing five or more alloying elements (concentration of each element ranging from 5 to 35 at. %). In the present study, HEAs are defined as single-phase solid solutions; CCAs contain at least two phases. The alloy concept of HEAs/CCAs is fundamentally different from most conventional alloys and promises interesting properties for industrial applications (e.g., to overcome the strength-ductility trade-off). To date, little attention has been paid to the weldability of HEAs/CCAs encompassing effects on the welding metallurgy. It remains open whether welding of HEAs/CCAs may lead to the formation of brittle intermetallics and promote elemental segregation at crystalline defects. The effect on the weld joint properties (strength, corrosion resistance) must be investigated. The weld metal and heat-affected zone in conventional alloys are characterized by non-equilibrium microstructural evolutions that most probably occur in HEAs/CCAs. The corresponding weldability has not yet been studied in detail in the literature, and the existing information is not documented in a comprehensive way. Therefore, this study summarizes the most important results on the welding of HEAs/CCAs and their weld joint properties, classified by HEA/CCA type (focused on CoCrFeMnNi and AlxCoCrCuyFeNi system) and welding process. KW - High-entropy alloy KW - Compositionally complex alloy KW - Welding KW - Properties KW - Review PY - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:b43-527068 SP - 1 EP - 15 PB - Springer Nature AN - OPUS4-52706 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Rhode, Michael A1 - Richter, Tim A1 - Schröpfer, Dirk A1 - Manzoni, Anna Maria T1 - Welding of high-entropy alloys - New material concept vs. old challenges N2 - HEAs represent a relatively new class of materials. The the alloy concept is fundamentally different from the most conventional materials and alloys that are used today. Recently, the focus of HEA designs is more application-based. For that purpose, the elements of interest are carefully selected and multiple phases as well as micro-structures are deliberately adjusted. Currently, only limited attention has been paid to weldability of HEA. This encompasses possible effects on metallurgy and its influence on the desired properties. It remains open if welding causes e.g. considerable number of intermetallic phases or segregations and their effect on weld joint properties. For that reason, the scope of this study is to summarize already available studies on welding of HEAs with respect to the HEA-type, the applied welding process and its influence on the weld joint properties. T2 - IIW Annual Assembly, Meeting of Commission II-A CY - Online meeting DA - 20.07.2020 KW - High-entropy alloy KW - Welding KW - Review PY - 2020 AN - OPUS4-51116 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Wunderli, S. A1 - Fortunato, G. A1 - Vogl, Jochen A1 - Pritzkow, Wolfgang T1 - Meterology of determination for a new cadmium atomic weight and metrological application to cadmium in rice using MC-ICP-MS KW - Atomic weight KW - Isotope KW - MC-ICP-MS KW - Cadmium KW - Determination of metrology of new cadmium atomic weight KW - Mass spectrometry KW - Review KW - Multicollector inductively coupled plasma mass spectrometry PY - 2003 SN - 1004-2997 VL - 24 IS - 4 SP - 467 EP - 470 CY - Beijing AN - OPUS4-31076 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kemna, A. A1 - Binley, A. A1 - Cassiani, G. A1 - Niederleithinger, Ernst A1 - Revil, A. A1 - Slater, L. A1 - Williams, K. H. A1 - Orozco, A.F. A1 - Haegel, F.-H. A1 - Hördt, A. A1 - Kruschwitz, Sabine A1 - Leroux, V. A1 - Titov, K. A1 - Zimmermann, E. T1 - An overview of the spectral induced polarization method for near-surface applications N2 - Over the last 15 years significant advancements in induced polarization (IP) research have taken place, particularly with respect to spectral IP (SIP), concerning the understanding of the mechanisms of the IP phenomenon, the conduction of accurate and broadband laboratory measurements, the modelling and inversion of IP data for imaging purposes and the increasing application of the method in near-surface investigations. We summarize here the current state of the science of the SIP method for near-surface applications and describe which aspects still represent open issues and should be the focus of future research efforts. Significant progress has been made over the last decade in the understanding of the microscopic mechanisms of IP; however, integrated mechanistic models involving different possible polarization processes at the grain/pore scale are still lacking. A prerequisite for the advances in the mechanistic understanding of IP was the development of improved laboratory instrumentation, which has led to a continuously growing data base of SIP measurements on various soil and rock samples. We summarize the experience of numerous experimental studies by formulating key recommendations for reliable SIP laboratory measurements. To make use of the established theoretical and empirical relationships between SIP characteristics and target petrophysical properties at the field scale, sophisticated forward modelling and inversion algorithms are needed. Considerable progress has also been made in this field, in particular with the development of complex resistivity algorithms allowing the modelling and inversion of IP data in the frequency domain. The ultimate goal for the future are algorithms and codes for the integral inversion of 3D, time-lapse and multi-frequency IP data, which defines a 5D inversion problem involving the dimensions space (for imaging), time (for monitoring) and frequency (for spectroscopy). We also offer guidelines for reliable and accurate measurements of IP spectra, which are essential for improved understanding of IP mechanisms and their links to physical, chemical and biological properties of interest. We believe that the SIP method offers potential for subsurface structure and process characterization, in particular in hydrogeophysical and biogeophysical studies. KW - Induced polarisation KW - Review KW - Moisture KW - Soil KW - Masonry resistivity PY - 2012 U6 - https://doi.org/10.3997/1873-0604.2012027 SN - 1569-4445 VL - 101 IS - 6 SP - 453 EP - 468 PB - EAGE - European Association of Geoscientists & Engineers CY - Houten AN - OPUS4-27433 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Baer, Wolfram ED - Frenz, Holger ED - Grellmann, Wolfgang T1 - Experimentelle Ermittlung dynamischer Bruchzähigkeitswerte von ferritischem Gusseisen mit Kugelgraphit - Normung und aktuelle Datenbasis N2 - Der vorliegende Beitrag befasst sich mit dem internationalem Status der Ermittlung und Verfügbarkeit dynamischer Bruchzähigkeitswerte ferritischer Gusseisenwerkstoffe mit Kugelgraphit. Einleitend wird der Stand bruchmechanischer Prüfnormen hinsichtlich der Definition von Kennwerten bei dynamischer Beanspruchung analysiert. Zur dynamischen Bruchzähigkeit von ferritischem Gusseisen mit Kugelgraphit wurde eine Datenbasis erstellt, die den aktuellen veröffentlichten Stand auf diesem Gebiet widerspiegelt und eine Vielzahl unterschiedlicher von den Autoren verwendeter Kennwertdefinitionen enthält. Daher ist eine systematische Auswertung dieser Datenbasis sehr schwierig. Zur Veranschaulichung des temperaturabhängigen Bruchverhaltens wurde jedoch eine Reihe von zusammenfassenden graphischen Darstellungen erarbeitet. Anhand derer wird der Informationsgehalt einzelner Kennwertgruppen diskutiert und deren Aussagekraft für den Fall einer Bauteilsicherheitsbewertung eingeschätzt. T2 - Herausforderungen neuer Werkstoffe an die Forschung und Werkstoffprüfung : Tagung Werkstoffprüfung 2008 CY - Berlin, Deutschland DA - 2008-12-04 KW - Dynamische Bruchzähigkeit KW - Review KW - Werkstoffkennwert KW - Duktiles Gusseisen KW - Dynamic fracture toughness KW - Review KW - Material characteristic KW - Ductile cast iron PY - 2008 SN - 978-3-00-026399-6 SN - 1861-8154 N1 - Serientitel: DVM-Bericht – Series title: DVM-Bericht IS - 642 SP - 275 EP - 282 PB - DVM CY - Berlin AN - OPUS4-18667 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -