TY - CONF A1 - Schumacher, Julia T1 - The roles of DHN melanin and the stress-activated MAP kinase in the rock inhabitant Knufia petricola N2 - Black fungi/yeasts exhibit high stress tolerance, yeast‑like or meristematic growth, and constitutive 1,8-dihydroxynaphthalene (DHN) melanin formation. Due to their slow growth, robust cell walls and the lack of sexual cycles and genetic tools, the underlying mechanisms of their phenotypic traits have remained largely unexplored. Using recently developed genetic tools, it is now possible to manipulate the genome of the rock-inhabiting model fungus Knufia petricola. Thus, gene functions and the cell biology of black fungi can be studied using CRISPR/Cas9-based genome editing and live-cell imaging with genetically encoded fluorescent proteins. Here, we are addressing the question to which extent constitutive pigment formation (melanin and carotenoids) and responses mediated by the stress-activated mitogen-activated protein (MAP) kinase contribute to the observed extremotolerance of K. petricola. The mutations of pks1, phs1 and both genes result in melanin-free (pink), carotenoid-free (black) and pigment-free (white) strains, respectively. The other putative melanogenic genes were identified in the genome, deleted to confirm their involvement in DHN melanogenesis and co-expressed in Saccharomyces cerevisiae for reconstruction of the synthesis pathway. Sak1 encoding the stress-activated MAP kinase was deleted in the wild-type and different pigment-deficient backgrounds. Growth of the obtained single, double and triple deletion mutants was tested by droplet tests on media supplemented with different stress-inducing agents. The Δsak1 mutants show slightly reduced growth rates even without environmental pressure and are hypersensitive to different stresses: e.g. osmotic, oxidative, membrane, pH and heat stress. Melanin-free Δsak1 mutants are more sensitive than black Δsak1 mutants to some but not all stress conditions, suggesting that melanin and the SAK1 pathway have complementary roles in protecting K. petricola from stress. T2 - 16th European Conference on Fungal Genetics CY - Innsbruck, Austria DA - 05.03.2023 KW - Black fungus KW - Extremotolerance KW - Pigments PY - 2023 AN - OPUS4-57147 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Richter, Matthias T1 - Metrological sound reference products for quality assurance and quality control measures in material emissions testing N2 - In industrialised countries more than 80% of the time is spent indoors. Products, such as building materials and furniture, emit volatile organic compounds (VOCs), which are therefore ubiquitous in indoor air. Different VOC combinations may, under certain environmental and occupational conditions, result in reported sensory irritation and health complaints. A healthy indoor environment can be achieved by controlling the sources and by eliminating or limiting the release of harmful substances into the air. One way is to use materials proven to be low emitting. Meanwhile, a worldwide network of professional commercial and non-commercial laboratories performing emission tests for the evaluation of products for interior use has been established. Therefore, comparability and metrological traceability of test results must be ensured. A laboratory’s proficiency can be proven by internal and external validation measures that both include the application of suitable reference materials. The emission test chamber procedure according to EN 16516 comprises several steps from sample preparation to sampling of test chamber air and chromatographic analysis. Quality assurance and quality control (QA/QC) must therefore be ensured. Currently, there is a lack of suitable reference products containing components relevant for the health-related evaluation of building products. The EU-funded EMPIR project 20NRM04 MetrIAQ (Metrology for the determination of emissions of dangerous substances from building materials into indoor air) aims to develop 1) gaseous primary reference materials (gPRM), which are used for the certification of gaseous (certified) reference materials (gCRM) and 2) emission reference materials (ERM). Most commercial gas standards of indoor-relevant compounds are not certified due to the lack of primary reference materials to which the project aims to contribute. The gPRM under development is a gas-phase standard containing trace levels of VOCs in nitrogen or air from the check standard according to EN 16516 (n-hexane, methyl isobutyl ketone, toluene, butyl acetate, cyclohexanone, o-xylene, phenol, 1,3,5-trimethylbenzene) with a target uncertainty of 5 %. The gPRM can be sampled into sorbent tubes to obtain transfer standards in the form of gCRM. The well characterised ERM represents a sample of a test specimen, e.g. building material, that is loaded into the emission test chamber for a period of several days and is used to evaluate the whole emission test chamber procedure. It shall have a reproducible and temporally constant compound release of less than 10 % variability over 14 days. Different approaches for retarded VOC release, such as the encapsulation of pure compounds and the impregnation of porous materials, are being tested to reach this aim. Furthermore, the design of the ERM is accompanied by the development of a numerical model for the prediction of the emissions for each of the target VOCs. The current progress of the work on both materials will be presented. T2 - CIM 2023 - 21st International Metrology Congress CY - Lyon, France DA - 07.03.2023 KW - Indoor air quality KW - VOC KW - Materials emissions testing KW - Emission reference material KW - Quality assurance/quality control PY - 2023 AN - OPUS4-57142 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Strangfeld, Christoph T1 - Moisture transport and measurements at BAM N2 - An overview over material moisture measurements and modelling of building materials at BAM. T2 - Rilem TC MMS Constituent meeting CY - Rabat, Morocco DA - 09.03.2023 KW - Material moisture KW - Moisture transport KW - Sorption isotherm KW - Sorption theory KW - Diffusion coefficient KW - NMR KW - Knudsen effect PY - 2023 AN - OPUS4-57141 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Strangfeld, Christoph T1 - Moisture diffusion affected by the Knudsen effect in temporal changing pore networks N2 - Almost all building materials in civil engineering have an open porosity and interact with or are affected by the environmental conditions. Structures might suffer from effects such as moisture adsorption, carbonation, corrosion, penetration of salt ions and chemical substances, etc. In the hygroscopic range, these processes are mostly driven by diffusion. Due to the confinement of small pores ( 1 m), the Knudsen effect reduces the molecular diffusion. This reduction can become more significant in case of temporal changing pore systems because of physisorption of water vapor, carbonation, or chemisorption. In this study, unstabilised earth blocks and earth masonry are investigated. In a first step, the pore size distribution of the blocks is measured and sorption isotherms are recorded in experiments. Besides the ordinary physisorption, the involved clay minerals undergo swelling or shrinking due to chemisorption. The following two effects must be considered: first, the reduction of the available pore space by the adsorbed water layer. For this, the Hillerborg sorption theory is used, which is a combination of the well-known Brunauer-Emmett-Teller sorption theory and the Kelvin equation. This allows the computation of adsorbed water layers even in curved pore geometries. Second, the variation of the initial pore size distribution due to chemisorption needs to be modelled. Based on these two models, the effective diffusion coefficient can be predicted. For validation, arrays of relative humidity sensors were embedded into a free-standing earth masonry wall. This monitoring was carried out over more than a year to have a broad variety of environmental conditions and was located in Berlin, Germany. The prediction of the effective diffusion coefficient can also be transferred to other processes and allows the investigation of materials having temporarily changing pore systems. Examples are the carbonation of cementitious materials, alkali silica reaction, calcium leaching of long-lasting structures, etc. This effect becomes most prominent in the meso-pore range and might alter the effective diffusion coefficient by more than 100 %. T2 - 4th International Congress on Materials & Structural Stability CY - Rabat, Morocco DA - 08.03.2023 KW - Earth masonry KW - Material moisture KW - Molecular diffusion KW - Chemisoprtion KW - Knudsen effect KW - Physisorption PY - 2023 AN - OPUS4-57140 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Lay, Vera T1 - Untersuchung eines Spritzbeton-Probekörpers unter Tage mit Ultraschall N2 - Für die sichere Endlagerung nuklearer Abfälle sind im Salzgestein Verschlussbauwerke aus Salzbeton als geotechnischen Barrieren vorgesehen. Um die Integrität der Bauwerke im Rahmen einer Qualitätssicherung nachzuweisen, eignet sich eine zerstörungsfreie Prüfung (ZfP) mit Ultraschall-Verfahren. Potenziell auftretende Risse oder Ablösungen sowie Einbauteile können detektiert werden. Um die Möglichkeiten und Grenzen der Ultraschall-Echo-Messungen sowie der Auswertemethoden zu untersuchen, wurden in einem aus Spritzbeton hergestellten Testbauwerk in der Grube Teutschenthal (bei Halle, Deutschland) verschiedene Störkörper während der Betonage eingebettet. Die Störkörper (Breite 3 cm bis ~8 cm) liegen in Tiefen von etwa 30 cm bis 80 cm und repräsentieren Hohlräume, Risse oder Inhomogenitäten des Betons. Von der Oberfläche führten wir Ultraschall-Echo-Messungen auf einer Fläche von etwa 100x150 cm² in einem 3D Modus durch. Die Auswertung erfolgte zunächst mithilfe der in der ZfP etablierten Synthetic-Aperture-Focusing Technique (SAFT), die der Kirchhoff Migration ähnelt. Insgesamt wird eine Vielzahl von Reflektoren im Bauwerk abgebildet, die jedoch nur in wenigen Fällen den eingebauten Störkörpern zugeordnet werden konnten, so dass auch die Grenzen des Verfahrens bei dieser Bauweise deutlich werden. Allerdings konnte eine ungeplante großflächige (>30 cm) Ablösung nachgewiesen und durch anschließende Bohrungen verifiziert werden. Um das strukturelle Abbild des Bauwerksinneren trotz des stark streuenden Spritzbetons zu verbessern, wenden wir fokussierende Migrationsverfahren an. Erste Ergebnisse zeigen, dass eine klarere Abbildung einzelner Reflektoren erreicht werden kann. Dies erleichtert die Detektion einzelner Objekte. Das hier präsentierte Experiment mit bekannten Reflektoren unter realen Bedingungen mit Spritzbeton unter Tage bietet hervorragende Möglichkeiten zur Überprüfung von methodischen Weiterentwicklungen im Bereich der Ultraschallanalyse. Durch die Verbesserung der Auswertemethodik und der darauf basierenden ultraschallbasierten Qualitätssicherungskonzepte werden insgesamt sicherere Verschlussbauwerke für nukleare Endlager ermöglicht. T2 - 83. Jahrestagung der Deutschen Geophysikalischen Gesellschaft (DGG) CY - Bremen, Germany DA - 06.03.2023 KW - Ultraschall KW - Spritzbeton KW - Qualitätssicherung KW - Abbildungsverfahren PY - 2023 AN - OPUS4-57136 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Liepold, Philipp T1 - Enhanced crack detection method using convolutional neural networks for Varestraint type tests N2 - A method to extract characteristics of cracks employing semantic segmentation on the basis of pictures taken via microscope, possible through advances in deep learning using a U-Net type model. T2 - IIW Intermediate Meeting CY - Garching, Germany DA - 05.12.2022 KW - CNN KW - MVT KW - AI PY - 2023 AN - OPUS4-57135 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kromm, Arne T1 - Increasing the Significance of Varestraint Tests through Improved Crack Evaluation N2 - It was found that there is a systematic dependence of the crack growth on the welding parameters as well as on the load. Decreasing welding speeds with simultaneously higher heat input promote crack formation with increasing strain rate. Based on the results, a new crack criterion was finally selected which allows an extended assessment of the material behavior during the MVT-test. The threshold introduced can quantify the dependencies of the crack formation on the welding and testing parameters, which could not be comprehensively described with the conventional evaluation. In principle, the evaluation routine can also be transferred to other Varestraint or externally loaded hot cracking tests. T2 - IIW Intermediate Meeting Comission II-c CY - Garching, Germany DA - 06.03.2023 KW - Solidification cracking KW - Varestraint-Test PY - 2023 AN - OPUS4-57131 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kuchenbecker, Petra T1 - Zentrifugen Sedimentationsverfahren CLS nach ISO 13318 2:2007 N2 - Einführung in die Bestimmung der Partikelgröße von Nano-Materialien mittels Zentrifugen Sedimentationsverfahren CLS nach ISO 13318 2:2007. Normative Grundlagen (einschließlich OECD TG 125), Messprinzip, Auswertung, Vor- und Nachteile der Methode, Metadaten, Reporting. T2 - BAM Akademie: Info-Tage "NANO OR NOT NANO" CY - Online meeting DA - 16.02.2023 KW - CLS KW - Particle size KW - Nano PY - 2023 AN - OPUS4-57129 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kuchenbecker, Petra T1 - Dynamische Lichtstreuung DLS nach ISO 22412:2017 N2 - Einführung in die Partikelgrößenbestimmung von Nano-Materialien mittels Dynamischer Lichtstreuung. Normative Grundlagen (ISO 22412 und OECD TG 125); Messprinzip, Auswertealgorithmen, Informationsgehalt der Daten, Metadaten, Reporting. T2 - BAM Akademie: Info-Tage "NANO OR NOT NANO" CY - Online meeting DA - 16.02.2023 KW - DLS KW - Particle size KW - Nano PY - 2023 AN - OPUS4-57128 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Holtappels, Kai T1 - Competence Centre H2Safety@BAM N2 - Deutschland hat mit verschiedenen Ländern Energiepartnerschaften geschlossen, darunter auch mit Japan. Im Rahmen des 3. Treffens der Wasserstoff-Arbeitsgruppe wurde das strategische Vorgehen beider Länder zu Entwicklungen von Wasserstoffrichtlinien, Zertifizierung und Sicherheit vorgestellt und diskutiert. Die BAM hat in einem Vortrag wichtige Themen aus dem Bereich der Sicherheitsforschung sowie zu sicherheitstechnischen Fragestellungen über die Wertschöpfungskette vorgestellt. Außerdem wurde das Arbeitsprogramm und ausgewählte Projekte des Kompetenzzentrums H2Safety@BAM vorgestellt. N2 - Germany has concluded energy partnerships with various countries, including Japan. During the 3rd meeting of the Hydrogen Working Group, the strategic approach of both countries on developments of hydrogen guidelines, certification and safety was presented and discussed. BAM gave a presentation on important topics in the field of safety research and on safety-related issues along the value chain. Furthermore, the work program and selected projects of the competence center H2Safety@BAM were presented. T2 - 3rd Meeting of the Hydrogen Working Group - Japanese-German Energy Partnership CY - Berlin, Germany DA - 27.02.2023 KW - Hydrogen KW - Japanese-German energy partnership KW - Safety KW - H2Safety@BAM PY - 2023 AN - OPUS4-57126 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -