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Unveiling the craftsmanship and knowledge behind iranian stuccoes (11th–14th centuries): New insights from an archaeometric perspective
No full textGypsum-based stucco decorations of 47 monuments in Iran, from the Seljuq to the Ilkhanid period (11th-14th centuries), were studied by multimodal analytical methods, including X-ray diffraction, X-ray fluorescence, scanning electron microscopy and image analysis to evaluate their composition properties. The assessment of results shows that stucco masters in those periods exerted control over the setting process of the gypsum-paste and its microstructure by adjusting water-to-plaster ratio, fine-clay addition, and by means of mechanical processing. Furthermore, the presence of anhydrite in the composition of stucco decorations located in the hot-desert climate of Iran provides evidence for the probability of gypsum-anhydrite transition, which has technical and preservation consequences for this less-investigated type of cultural materials
Understanding the effect of oxide ions on Solar Salt chemistry and corrosion mechanism of 316L stainless steel at 600 °C
No full textSolar Salt (60 wt% NaNO3, 40 wt% KNO3), used in Concentrated Solar Power (CSP) Thermal Energy Storage (TES) technology, can decompose into various products at elevated temperatures, with oxide ions being one of the known corrosive byproducts. The study mimics Solar Salt aging by intentionally adding sodium peroxide (Na2O2) and sodium oxide (Na2O) at concentrations of 0.005–0.33 wt% to investigate their role in the corrosion of austenitic stainless steel at 600 °C in typical operating conditions. Salt chemistry (nitrite, nitrate, oxide ions, and metal cations) was analyzed every 24 h, and steel corrosion after 168 h was assessed by weight change, corrosion rate, phase analysis, and cross-sectional morphology. Results reveal that at or above 0.135 wt% added Na2O2/Na2O leads to a quasi-steady-state equilibrium of oxide ions in the salt. Interestingly, at these concentrations, the presence of steel further decreases oxide ion concentration. Furthermore, above 0.135 wt%, the corrosion rate increases significantly, along with increased spallation, porosity and disintegration of the corrosion layer, forming a non-protective layer. This study highlights the critical role of oxide ions in the corrosion process
Digital Transformation in Materials Science through Semantic Technologies and Knowledge Graphs
No full textThe field of materials science is undergoing a transformative shift driven by digitalization. In this respect, semantic and AI technologies are paving the way for advancements in materials development, design, and optimization while leaping towards an Industry 4.0 environment. Addressing the dual challenges of quality assurance and data interoperability, this presentation examines the integration of semantic technologies and knowledge representation methods. By adhering to FAIR principles, this approach enhances data management, storage, and reuse. That way, both machine-actionable and human-understandable data structures crucial for digital research environments are fostered.
This presentation focuses on the ‘platform MaterialDigital’ (PMD) initiative, which aims to support efforts from both industrial and academic sectors to solve digitalization challenges and implement sustainable digital solutions. Besides establishing structures to create virtual material data spaces, PMD develops solutions for systematizing and unifying the handling of hierarchical, process-dependent material data. Semantic technologies play a crucial role in digitalization efforts as they enable the storage, processing, and querying of data in a contextualized form. Therefore, the development and prototypical application of the PMD Core Ontology 3.0 (PMDco 3.0) tailored for materials science is highlighted. This includes the design and documentation of graph patterns that may be compiled into rule-based semantic shapes. Its integration into daily lab life is demonstrated through its application to electronic lab notebooks (ELN). This illustrates potentials of standardized protocols and automation-ready solutions for managing diverse experimental data across different sources.
Outlining best practices and illustrating the possibilities that semantic technologies bring to modern labs, examples from materials processing and mechanical testing will underscore how knowledge graphs bridge the gap between data and decision-making in materials science, with potential for increased productivity and streamlined workflows across the field
Tanks und GasspeicherÄnderungen an der BAM im FB 3.5 Sicherheit von Gasspeichern
No full textDer Vortrag erläutert die organisatorischen Änderungen, die für DIN und die IGV/DVFG-Mitglieder von Bedeutung sind, und wie die Struktur der handelnden Personen von Änderungen betroffen ist.
Es werden die Erfolge des letzten Jahres dargestellt und die gemeinsamen Herausforderungen in Norm und Recht gemeinsam mit den zugehörigen Lösungsansätzen der BAM erläutert
ZIF-derived Atomically Dispersed Non-precious Metal Catalysts (M-N-C) for Electrochemical Energy Applications
No full textZeolitic imidazolate frameworks (ZIFs) which are a subtype of metal organic frameworks (MOFs) have been extensively used to prepare catalyst materials for a variety of electrochemical reactions for energy conversion and storage applications. Most notable examples of ZIFs used for that purpose include ZIF-8 and ZIF-67 etc. Particularly ZIF-8 with its high surface area, defined pore structure and tunable particle size is widely utilized as a platform material to prepare so-called metal- and nitrogen-doped carbon (M-N-C) catalysts with M= Co, Fe, Ni, Zn etc., which are an emerging class of catalyst materials and consist of nitrogen-doped porous carbon matrix hosting atomically distributed active metal sites.[1, 2] The active sites in M-N-Cs ideally have M-N4 coordination resembling to metal centres in macromolecules such as porphyrins and phthalocyanines.[3] Most representative examples of M-N-Cs include Fe-N-Cs, Co-N-Cs and Ni-N-Cs etc. which are showing promising activities for a variety of electrochemical reactions e.g. oxygen reduction reaction (ORR), carbon dioxide reduction reaction (CO2RR) and hydrogen evolution reaction (HER). The structures of M-N-C catalysts are quite complex and require a fine balance between morphological, electronic, and chemical properties to reach optimal electrocatalytic activities. In this talk, I will present our activities on (i) preparation of phase-pure M-N-C catalysts derived from ZIF-8 via active-site imprinting [4, 5] and highlight the benefits of our strategy to achieve high density of active sites and enhanced electrochemical performance levels [6] and (ii) feasibility of using gas physisorption techniques as a new approach to quantify active sites in M-N-Cs. The challenges of maximizing active site utilization and eliminating unfavourable mass-transport characteristics faced by ZIF-8 derived M-N-Cs in electrochemical energy devices e.g. fuel cells will also be briefly discussed
Phonon workflow and applications
No full textThis talk introduced the participants to phonons and how they are typically computed. Then, I introduced the participants to the harmonic phonon, the Grüneisen, and the quasi-harmonic workflow that allows the computation of properties related to phonons. I also had detailed examples of how these workflows can be used in practice. Beyond this, I showed how these workflows can be used to automatically benchmark interatomic potentials and use them for the development of such potentials
Die Schallemissionsprüfung in der Überwachung von Gasspeichern aus Composite - Handlungsempfehlungen für pränormative Forschung & Handlungsbedarfe für Regulatorik
No full textDie Transporteinheiten für Wasserstoff auf der Straße nehmen stark zu. Der Aufwand für die wiederkehrende Prüfung nimmt schneller zu als die dafür verfügbaren Kapazitäten. Gleichzeitig wird immer mehr in Groß0serien hergestellt. Vor diesem Hintergrund spielt die Effizienz in der Prüfung eine zunehmende Rolle. Verlässt man den Transportbereich kommt auch der Aspekt der Machbarkeit hinzu. Große stationäre Speichersysteme mit vielen Einzelelementen lassen sich organisatorisch und bzgl. Verfügbarkeit mit 100%-Wasserdruckprüfungen nicht mehr wirtschaftlich darstellen.
Das Ziel ist es, für nicht einzeln gehandhabten, sondern fest eingebauten Speicher, den Aufwand in der Prüfung erheblich zu reduzieren, indem Stichproben gezogen werden und die Prüfergebnisse für die Gruppe gleicher und gleich eingesetzter Speicher herangezogen werden. Dies hat zwei Grenzen: Zum einen muss das Prüfverfahren aussagekräftig genug sein, um eine statistische verwendbare Aussage zu liefern, die eindeutige Schlüsse auf die Sicherheit zulässt. Zum anderen muss das Urteil über die Gruppe eine hinreichende Zuverlässigkeit im Betrieb belegen. Ist diese Bedingung nicht mehr erfüllt, wird die Gruppe wieder der 100%-Prüfung zugeführt, um mit dem gleichen Prüfverfahren wie bei der Stichprobenprüfung, schlechte von guten Individuen zu trennen.
Hierzu bedarf es der Weiterentwicklung der Schallemissionsanalyse als zerstörungsfreies Prüfverfahren und eines passenden Stichprobenansatzes mit probabilistischer Bewertung. Beides erfordert pränormativer Forschung und nachfolgende Rechtsänderungen
Investigation of corrosion behavior of S355 steel in artificial seawater and sediment
No full textThe safe operation of offshore wind turbines places high demands on corrosion protection. This is particularly the case about the planned future extension of the service life beyond 25 years. The highly corrosive environment towards metallic materials leads to a loss of material thickness of the tower structure and thus to a deterioration of mechanical properties. This can be counteracted by corrosion protection measures adapted to the respective load case, such as organic coatings and cathodic corrosion protection (CCP). Much research has already been done in this area about inhibiting the corrosion process and there are regulations and guidelines that specify requirements for corrosion protection to achieve the required service lives.
However, gaps exist regarding free corrosion. This plays a greater role especially for time intervals during the installation of the plants and their maintenance, during which often no CCP can be operated. This applies to the exposure areas in the underwater and sediment area. This problem is intensified by the difficult to estimate corrosion rates caused by the different zones, with their different amounts of dissolved oxygen and the various influencing factors.
This paper deals with experiments conducted in a laboratory container with artificial seawater and sediment in basins
A quality-by-design inspired approach to develop PET and PP nanoplastic test materials for use in in vitro and in vivo biological assays
No full textMicro- and nanoplastics have become environmental pollutants of concern, receiving increased attention from consumers, scientists, and policymakers. The lack of knowledge about possible impacts on wildlife and human health requires further research, for which well-characterized testmaterials are needed. A quality-bydesign (QbD) driven approachwas used to produce sterile, endotoxinmonitored nanoplastics of polyethylene terephthalate (PET) and polypropylene (PP) with a size fraction of >90% below 1 μm and high yield of >90%. Glycerol was used as a versatile and biocompatible liquid storage medium which requires no further exogenous dispersing agent andmaintained colloidal stability, sterility (0 CFU mL−1), and low endotoxin levels (<0.1 EU mL−1) for more than one year of storage at room temperature. Further, the glycerol vehicle showed no biological effect on the tested human bronchial cell line Calu-3 up to 0.8% (w/v). Given the concentration of 40 mg g−1 nanoplastics in the glycerol stock, this corresponds to a nanoplastic concentration of 320 μg mL−1. The surfactant-free nanoplastics are dispersible in bio-relevant media from the glycerol stock without changing size characteristics and are suitable for in vitro and in vivo research
Green primary explosives – a step towards more sustainable mining
No full textThis project aims at breaking down barriers that hinder the wide application of green primary explosives. In a joint effort of several organisational units at BAM we connect chemistry, process engineering and plant and process safety to investigate how green primary explosives can be produced in an economical and safe process