TY - JOUR A1 - Titscher, Thomas A1 - Unger, Jörg F. A1 - Oliver, J. T1 - Implicit explicit integration of gradient enhanced damage models N2 - Quasi-brittle materials exhibit strain softening. Their modeling requires regularized constitutive formulations to avoid instabilities on the material level. A commonly used model is the implicit gradient-enhanced damage model. For complex geometries, it still Shows structural instabilities when integrated with classical backward Euler schemes. An alternative is the implicit–explicit (IMPL-EX) Integration scheme. It consists of the extrapolation of internal variables followed by an implicit calculation of the solution fields. The solution procedure for the nonlinear gradient-enhanced damage model is thus transformed into a sequence of problems that are algorithmically linear in every time step. Therefore, they require one single Newton–Raphson iteration per time step to converge. This provides both additional robustness and computational acceleration. The introduced extrapolation error is controlled by adaptive time-stepping schemes. This paper introduced and assessed two novel classes of error control schemes that provide further Performance improvements. In a three-dimensional compression test for a mesoscale model of concrete, the presented scheme was about 40 times faster than an adaptive backward Euler time integration. KW - Implicit explicit schemes KW - Gradient-enhanced damage model KW - Adaptive time stepping KW - Continuum damage KW - Robustness PY - 2019 DO - https://doi.org/10.1061/(ASCE)EM.1943-7889.0001608 SN - 0733-9399 SN - 1943-7889 VL - 145 IS - 7 SP - 04019040-1 EP - 04019040-13 PB - ASCE - American Society of Civil Engineers AN - OPUS4-48361 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - De Samber, B. A1 - Scharf, Oliver A1 - Buzanich, Günter A1 - Garrevoet, J. A1 - Tack, P. A1 - Radtke, Martin A1 - Riesemeier, Heinrich A1 - Reinholz, Uwe A1 - Evens, R. A1 - De Schamphelaere, K. A1 - Falkenberg, G. A1 - Janssen, C. A1 - Vincze, L. T1 - Three-dimensional X-ray fluorescence imaging modes for biological specimens using a full-field energy dispersive CCD camera N2 - Besides conventional scanning X-ray fluorescence imaging at synchrotron sources, full-field X-ray fluorescence (FF-XRF) imaging techniques that do not implicitly require spatial scanning of the sample have become available. FF-XRF has become achievable thanks to the development of a new type of energy dispersive CCD-based 2D detector, also referred to as a 'color X-ray camera (CXC)' or 'SLcam'. We report on different imaging schemes for biological samples using FF-XRF imaging: (a) 2D 'zoom' imaging with pinhole optics using the 'camera obscura' principle; (b) 2D 'fixed magnification' imaging using magnifying polycapillary optics; and (c) 3D-FF-XRF imaging using an X-ray sheet beam or computed tomography (CT). The different FF-XRF imaging modes are illustrated using the crustacean Daphnia magna, a model organism for investigating the effects of metals on organism/ecosystem health, and foraminifera, a class of amoeboid protist. Detailed analytical characterization of the set-up is performed through analyzing various reference materials in order to determine limits of detection (LODs) and sensitivities. Experiments were performed using the BAMline at the BESSY synchrotron (Berlin, Germany) and using the P06 Hard X-ray Microprobe at the PETRAIII synchrotron (Hamburg, Germany). KW - CXC KW - BAMline KW - Maia detector KW - Synchrotron PY - 2019 DO - https://doi.org/10.1039/c9ja00198k VL - 34 IS - 10 SP - 2083 EP - 2093 PB - Royal Society of Chemistry CY - Cambridge, United Kingdom AN - OPUS4-49359 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Guehrs, E. A1 - Schneider, M. A1 - Günther, Ch. M. A1 - Hessing, P. A1 - Heitz, K. A1 - Wittke, D. A1 - López-Serrano Oliver, Ana A1 - Jakubowski, Norbert A1 - Plendl, J. A1 - Eisebitt, S. A1 - Haase, A. T1 - Quantification of silver nanoparticle uptake and distribution within individual human macrophages by FIB/SEM slice and view N2 - Quantification of nanoparticle (NP) uptake in cells or tissues is very important for safety assessment. Often, electron microscopy based approaches are used for this purpose, which allow imaging at very high resolution. However, precise quantification of NP numbers in cells and tissues remains challenging. The aim of this study was to present a novel approach, that combines precise quantification of NPs in individual cells together with high resolution imaging of their intracellular distribution based on focused ion beam/ scanning electron microscopy (FIB/SEM) slice and view approaches. KW - Nanoparticles KW - FIB/SEM slice and view KW - Absolute dose KW - Cellular internalization KW - Macrophage PY - 2017 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-400626 DO - https://doi.org/10.1186/s12951-017-0255-8 SN - 1477-3155 VL - 15 SP - Article 21, 1 EP - 11 AN - OPUS4-40062 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Brücher, M. A1 - von Bohlen, A. A1 - Jacob, P. A1 - Franzke, J. A1 - Radtke, Martin A1 - Reinholz, Uwe A1 - Müller, Bernd R. A1 - Scharf, Oliver A1 - Hergenröder, R. T1 - The charge of solid-liquid interfaces measured by X-ray standing waves and streaming current N2 - Measurements of ion distributions at a charged solid–liquid interface using X-ray standing waves (XSW) are presented. High energy synchrotron radiation (17.48 keV) is used to produce an XSW pattern inside a thin water film on a silicon wafer. The liquid phase is an aqueous solution containing Br and Rb ions. The surface charge is adjusted by titration. Measurements are performed over a pH range from 2.2–9, using the native Si oxide layer and functional (amine) groups as surface charge. The Debye length, indicating the extension of the diffuse layer, could be measured with values varying between 1–4 nm. For functionalized wafers, the pH dependent change from attraction to repulsion of an ion species could be detected, indicating the isoelectric point. In combination with the measurement of the streaming current, the surface charge of the sample could be quantified. KW - Interfacial charge KW - Solid/liquid interfaces KW - Surface analysis KW - Surface functionalization KW - X-ray spectrometry KW - X-ray KW - Standing waves KW - XSW KW - Streaming current KW - Synchrotron radiation PY - 2010 DO - https://doi.org/10.1002/cphc.201000166 SN - 1439-4235 SN - 1439-7641 VL - 11 IS - 10 SP - 2118 EP - 2123 PB - Wiley-VCH Verl. CY - Weinheim AN - OPUS4-22057 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Mozir, A. A1 - Gonzalez, L. A1 - Cigic, I.K. A1 - Wess, T. J. A1 - Rabin, Ira A1 - Hahn, Oliver A1 - Strlic, M. T1 - A study of degradation of historic parchment using small-angle X-ray scattering, synchrotron-IR and multivariate data analysis N2 - Parchment has been in use for thousands of years and has been used as the writing or drawing support for many important historic works. A variety of analyticaltechniques is currently used for routine assessment of the degree of denaturation of historic parchment; however, because parchment has a heterogeneous nature, analytical methods with high spatial resolution are desirable. In this work, the use of small-angle X-ray scattering (SAXS) and synchrotron-IR (SR-IR) was examined in conjunction with multivariate data analysis to study degradation of an extended set of historic parchment samples, and particularly to investigate the effect of lipids and the presence of iron gall ink on the degradation processes. In the data analysis, shrinkage temperature, lipid content, sample age, presenceof ink and accelerated degradation were included. The analysis of loading factors in partial least-squares Regression and principal component analyses based on SAXS, SR-IR and other analytical and descriptive data reveals the effect of lipid removal on diffraction patterns, and lipids are found to cause the degradation process in parchment to accelerate. The effect of iron gall ink is also evident, although the mechanism of ageing is different to that of natural ageing in the absence of ink. In addition, a historic parchment score from ca. 1750 is examined, demonstrating the significant effect of iron gall ink, and lipids and inorganic soiling on ist increased degradation. KW - Small-angle X-ray scattering KW - Multivariate data analysis KW - Degradation KW - Collagen KW - Lipids KW - Iron gall ink PY - 2012 DO - https://doi.org/10.1007/s00216-011-5392-6 SN - 1618-2642 SN - 1618-2650 VL - 402 IS - 4 SP - 1559 EP - 1566 PB - Springer CY - Berlin AN - OPUS4-25506 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Bosc-Bierne, Gaby A1 - Ewald, Shireen A1 - Kreuzer, Oliver J. A1 - Weller, Michael G. T1 - Efficient Quality Control of Peptide Pools by UHPLC and Simultaneous UV and HRMS Detection N2 - Peptide pools consist of short amino acid sequences and have proven to be versatile tools in various research areas in immunology and clinical applications. They are commercially available in many different compositions and variants. However, unlike other reagents that consist of only one or a few compounds, peptide pools are highly complex products which makes their quality control a major challenge. Quantitative peptide analysis usually requires sophisticated methods, in most cases isotope-labeled standards and reference materials. Usually, this would be prohibitively laborious and expensive. Therefore, an approach is needed to provide a practical and feasible method for quality control of peptide pools. With insufficient quality control, the use of such products could lead to incorrect experimental results, worsening the well-known reproducibility crisis in the biomedical sciences. Here we propose the use of ultra-high performance liquid chromatography (UHPLC) with two detectors, a standard UV detector at 214 nm for quantitative analysis and a high-resolution mass spectrometer (HRMS) for identity confirmation. To be cost-efficient and fast, quantification and identification are performed in one chromatographic run. An optimized protocol is shown, and different peak integration methods are compared and discussed. This work was performed using a peptide pool known as CEF advanced, which consists of 32 peptides derived from cytomegalovirus (CMV), Epstein–Barr virus (EBV) and influenza virus, ranging from 8 to 12 amino acids in length. N2 - Peptidpools bestehen aus kurzen Aminosäuresequenzen und haben sich als vielseitige Werkzeuge in verschiedenen Forschungsbereichen der Immunologie und bei klinischen Anwendungen erwiesen. Sie sind in vielen verschiedenen Zusammensetzungen und Varianten im Handel erhältlich. Im Gegensatz zu anderen Reagenzien, die nur aus einer oder wenigen Verbindungen bestehen, sind Peptidpools jedoch hochkomplexe Produkte, was ihre Qualitätskontrolle zu einer großen Herausforderung macht. Die quantitative Peptidanalyse erfordert in der Regel ausgefeilte Methoden, in den meisten Fällen isotopenmarkierte Standards und Referenzmaterialien. Dies ist in der Regel sehr aufwändig und teuer. Daher wird ein Ansatz benötigt, der eine praktische und praktikable Methode zur Qualitätskontrolle von Peptidpools bietet. Bei unzureichender Qualitätskontrolle könnte die Verwendung solcher Produkte zu falschen Versuchsergebnissen führen, was das bekannte Problem der Reproduzierbarkeit in den biomedizinischen Wissenschaften noch verschärfen würde. Hier schlagen wir die Verwendung der Ultrahochleistungs-Flüssigkeitschromatographie (UHPLC) mit zwei Detektoren vor, einem Standard-UV-Detektor bei 214 nm für die quantitative Analyse und einem hochauflösenden Massenspektrometer (HRMS) für die Identitätsbestätigung. Um kosteneffizient und schnell zu sein, werden Quantifizierung und Identifizierung in einem einzigen chromatographischen Lauf durchgeführt. Es wird ein optimiertes Protokoll gezeigt, und es werden verschiedene Peak-Integrationsmethoden verglichen und diskutiert. Für diese Arbeit wurde ein Peptidpool verwendet, der als CEF advanced bekannt ist und aus 32 Peptiden besteht, die vom Cytomegalovirus (CMV), Epstein-Barr-Virus (EBV) und Influenzavirus stammen und zwischen 8 und 12 Aminosäuren lang sind. KW - Synthetic peptides KW - Quality control KW - Impurites KW - Byproducts KW - Degradation KW - Mass spectrometry KW - Orbitrap PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-602299 DO - https://doi.org/10.3390/separations11050156 SN - 2297-8739 VL - 11 IS - 5 SP - 1 EP - 18 PB - MDPI CY - Basel AN - OPUS4-60229 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - INPR A1 - Bosc-Bierne, Gaby A1 - Ewald, Shireen A1 - Kreuzer, Oliver J. A1 - Weller, Michael G. T1 - Efficient Quality Control of Peptide Pools N2 - Peptide pools composed of short amino acid sequences have proven to be versatile tools in various research areas and clinical applications. They are powerful tools for epitope mapping, immunotherapy, and vaccine development. Their importance lies in their ability to map complex protein structures, enabling a comprehensive understanding of immune responses and facilitating the identification of potential therapeutic agents. The application of peptide pools also extends to the field of personalized medicine, offering tailored solutions for diseases such as cancer and infectious diseases. Peptide pools are complex mixtures of immunostimulatory antigens primarily intended for T-cell stimulation. They are commercially available in many different compositions and variants. However, unlike other reagents that consist of only one or a few compounds, peptide pools are highly complex products with limited stability. This makes their quality control a major challenge. Quantitative peptide analysis usually requires sophisticated methods, in most cases isotope-labeled standards and reference materials. None of these are routinely available for these products. Synthesis and purification of all labeled peptides might be required. Usually, this approach would be prohibitively laborious and expensive. Therefore, an approach is needed to provide a practical and feasible method for quality control of peptide pools. With insufficient quality control, the use of such products could lead to incorrect experimental results, which would worsen the well-known reproducibility crisis in the biomedical sciences. Here we propose the use of ultra-high performance liquid chromatography (UHPLC) with two detectors, a standard UV detector (at 214 nm) for quantitative analysis and a high-resolution mass spectrometer (HRMS) for identity confirmation. To be cost-efficient and fast, quantification and identification are performed in one chromatographic run. An optimized protocol is shown, and different peak integration methods are compared and discussed. This work was performed using a peptide pool known as CEF, which consists of 32 peptides derived from cytomegalovirus (CMV), Epstein-Barr virus (EBV) and influenza virus, ranging from 8 to 12 amino acids in length. N2 - Peptidpools, die aus kurzen Aminosäuresequenzen bestehen, haben sich in verschiedenen Forschungsbereichen und klinischen Anwendungen als vielseitige Werkzeuge erwiesen. Sie sind leistungsstarke Werkzeuge für die Epitopkartierung, die Immuntherapie und die Impfstoffentwicklung. Ihre Bedeutung liegt in ihrer Fähigkeit, komplexe Proteinstrukturen zu kartieren, was ein umfassendes Verständnis der Immunantworten ermöglicht und die Identifizierung potenzieller Therapeutika erleichtert. Die Anwendung von Peptidpools erstreckt sich auch auf den Bereich der personalisierten Medizin und bietet maßgeschneiderte Lösungen für Krankheiten wie Krebs und Infektionskrankheiten. Peptidpools sind komplexe Mischungen immunstimulierender Antigene, die hauptsächlich zur T-Zell-Stimulation bestimmt sind. Sie sind in vielen verschiedenen Zusammensetzungen und Varianten im Handel erhältlich. Im Gegensatz zu anderen Reagenzien, die nur aus einer oder wenigen Verbindungen bestehen, sind Peptidpools jedoch hochkomplexe Produkte mit begrenzter Stabilität. Dies macht ihre Qualitätskontrolle zu einer großen Herausforderung. Die quantitative Peptidanalyse erfordert in der Regel ausgefeilte Methoden, in den meisten Fällen isotopenmarkierte Standards und Referenzmaterialien. Keines dieser Verfahren ist für diese Produkte routinemäßig verfügbar. Möglicherweise ist die Synthese und Reinigung aller markierten Peptide erforderlich. In der Regel wäre dieser Ansatz unerschwinglich aufwendig und teuer. Daher ist ein Ansatz erforderlich, der eine praktische und praktikable Methode für die Qualitätskontrolle von Peptidpools bietet. Bei unzureichender Qualitätskontrolle könnte die Verwendung solcher Produkte zu falschen Versuchsergebnissen führen, was die bekannte Reproduzierbarkeitskrise in den biomedizinischen Wissenschaften verschlimmern würde. Hier schlagen wir die Verwendung der Ultrahochleistungsflüssigkeitschromatographie (UHPLC) mit zwei Detektoren vor, einem Standard-UV-Detektor (bei 214 nm) für die quantitative Analyse und einem hochauflösenden Massenspektrometer (HRMS) für die Identitätsbestätigung. Um kosteneffizient und schnell zu sein, werden Quantifizierung und Identifizierung in einem chromatographischen Durchlauf durchgeführt. Es wird ein optimiertes Protokoll vorgestellt und verschiedene Peak-Integrationsmethoden werden verglichen und diskutiert. Diese Arbeit wurde mit einem Peptidpool namens CEF durchgeführt, der aus 32 Peptiden besteht, die vom Cytomegalovirus (CMV), Epstein-Barr-Virus (EBV) und Influenzavirus stammen und zwischen 8 und 12 Aminosäuren lang sind. KW - Quality control KW - UHPLC-UV-HRMS KW - Relative peptide quantification KW - Compound confirmation KW - Structure confirmation KW - Cost efficiency KW - Infectious diseases KW - Orbitrap PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-621307 DO - https://doi.org/10.20944/preprints202404.0992.v1 SN - 2310-287X SP - 1 EP - 18 PB - MDPI CY - Basel AN - OPUS4-62130 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Müller, B. A1 - Jann, Oliver A1 - Horn, Wolfgang A1 - Panaskova, J. A1 - Müller, D. A1 - Plehn, W. T1 - Sensory tests for building materials and rooms - Status of the standardisation N2 - To control the emission of pollutants from building materials, a few different voluntary labelling Systems have been introduced in Europe. In Germany mandatory “Principles for the health assessment of construction products used in interiors” have also been applied for the technical approval of floor coverings since 2004. All of these both voluntary and mandatory Systems combine measurements of volatile organic compounds according to ISO 16000-9 and sensory evaluations (new ISO 16000-28). In this paper a German project financed by the Umweltbundesamt (Federal Environmental Agency) will be presented. The project deals with the questions of how to combine the emission tests with the sensory evaluation and what the best sensory evaluation procedure is for achieving valid and accurate results. The limited values and the evaluation methods will be presented and discussed. In the next Step the criteria for labelling those products without an unpleasant odour will be determined. The current Status of ISO 16000 - 28 and 30 will be also presented. T2 - Healthy Buildings 2012 - 10th International conference CY - Brisbane, Australia DA - 08.07.2012 KW - Sensory evaluation of building materials and rooms KW - Perceived air quality KW - Standardisation KW - Label KW - Normung KW - Geruch KW - Messmethoden KW - Emissionsmessung KW - Bauprodukte PY - 2012 SN - 978-1-921897-40-5 SP - 1 EP - 6 (3E.5) AN - OPUS4-27561 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - INPR A1 - Smales, Glen J. A1 - Appel, Paul Alexander A1 - Breßler, Ingo A1 - Chambers, Aaron A1 - Dumele, Oliver A1 - Ebisch, Maximilian A1 - Frontzek, Julius A1 - del Refugio Monroy, José A1 - Rosalie, Julian M. A1 - Pauw, Brian R. T1 - DACHS and RoWaN: The Automated and Traceable Synthesis of ZIF-8 N2 - Automated synthesis and open-data practices are increasingly seen as key enablers of transparent, traceable, and reproducible science. By combining automation with structured, metadata-rich documentation, it becomes possible to systematically com- pare synthesis strategies and link outcomes to detailed parameters. In this work, we implement such an approach to study the synthesis of ZIF-8, comparing hand and automation-assisted methods under controlled conditions. Using over 100 synthesis experiments, we assess the repeatability of particle size and yield, and explore how variations in mixing and injection influence outcomes. This study demonstrates how traceable synthesis workflows can support repeatability and comparison across synthe- sis strategies. The DACHS (Database for Automation, Characterization and Holistic Synthesis) framework underpins this work, providing a lightweight infrastructure for transparent synthesis data capture. KW - Automation KW - MOFs KW - SAXS PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-645861 DO - https://doi.org/10.26434/chemrxiv-2025-7fgg0 SP - 1 EP - 32 PB - Cambridge AN - OPUS4-64586 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Bretz, S. A1 - Hagnau, C. A1 - Hahn, Oliver A1 - Ranz, H.-J. A1 - Täube, D. A1 - Wolff, Timo T1 - Was ist tatsächlich Schwarzlotmalerei? T2 - Jahrestagung in der Pinakothek der Moderne - Archäometrie und Denkmalpflege CY - München, Deutschland DA - 2009-03-25 KW - Archäometrie KW - Zerstörungsfreie Prüfung KW - Hinterglasmalerei PY - 2009 SN - 0947-6229 IS - 2 SP - 246 EP - 248 PB - Dt. Bergbau-Museum CY - Bochum AN - OPUS4-19336 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -