TY - RPRT A1 - Ballach, F. A1 - Bartscher, M. A1 - Bellon, Carsten A1 - Borges de Oliveira, F. A1 - Braun, M. A1 - Dennerlein, F. A1 - Flessner, M. A1 - Fuchs, P. A1 - Günnewig, O. A1 - Hausotte, T. A1 - Hess, J. A1 - Kasperl, S. A1 - Kirschbaum, K. A1 - Li, K. A1 - Maass, N. A1 - Mayer, T. A1 - Orth, Anthony A1 - Reuter, T. A1 - Suppes, A. A1 - von Schmid, M. A1 - Weiß, D. T1 - Realistische Simulation realer Röntgencomputertomografie-Systeme mit basisqualifizierter Simulationssoftware – CTSimU2 BT - Abschlussbericht N2 - Das Förderprojekt CTSimU2 baute auf den Ergebnissen des Projektes CTSimU auf. Dieses Vorprojekt erarbeitete ein (Basis-)Qualifizierungsframework für Simulationssoftwares zur Anwendung bei der Röntgen-CT für dimensionelle Messungen. Dabei stand die ausreichende physikalische Korrektheit der Durchstrahlungssimulation im Vordergrund. Für die realitätsnahe Simulation einer CT-Anlage in einer Simulationssoftware (Digitales Modell) ist jedoch nicht nur die Korrektheit der Simulationssoftware selbst, sondern auch die Güte der Parametrisierung des realen CT-Systems in der Simulationssoftware entscheidend – dies stellte den Ausgangspunkt dar. Die Parametrisierung eines CT-Systems in einer Simulationssoftware lässt sich in vier Schritte unterteilen: nach der Datenaufnahme am realen CT-System folgt die Auswertung der aufgenommenen Daten für die Generierung allgemeiner Parameterangaben. Als letztes folgte die Übertragung der Parameter in die spezifischen Simulationssoftwares und die Validierung der resultierenden Simulationsparameter. Die Methodik der Datenaufnahme am CT und die Auswertung der Daten wurde in einem Werkzeugkasten allgemein beschrieben. Der dritte Schritt, die Umsetzung der Parameter, war softwarespezifisch und wurde beispielhaft mit den vorhandenen Simulationssoftwares durchgeführt. Die Validierung der Parameter war standardisierbar und konnte durch den entwickelten Test geleistet werden, auf dessen Basis die ausreichend korrekte Simulation einer realen Anlage beurteilt werden konnte. Endresultat des Projektes war ein Richtlinienentwurf (z. B. VDI/VDE 2630) zu diesem Test, der einen informativen Annex zum Stand der Technik bezüglich der Möglichkeiten zur Parameterbestimmung enthält. Mit einer Simulationssoftware, die die Basisqualifizierung aus CTSimU bestanden hat und einen Parameterdatensatz für ein reales CT-System enthält, der den Test aus CTSimU2 bestanden hat, können realistische Simulationen dieses CT-Systems möglich sein. KW - Computertomografie KW - Simulation KW - Dimensionelles Messen PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-641719 DO - https://doi.org/10.34657/21602 N1 - Dieses Projekt wurde durch die Förderrichtlinie WIPANO gefördert und durch das Bundesministerium für Wirtschaft und Klimaschutz (2022 -2025) finanziert. Der Projektträger Jülich verwaltet die Projekte der Förderrichtlinie WIPANO. SP - 1 EP - 22 PB - TIB Technische Informationsbibliothek CY - Hannover AN - OPUS4-64171 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Becker, S. A1 - Beckmann, Jörg A1 - Braun, M.-T. A1 - Cojocari, O. A1 - Feige, V. A1 - Fischer, B. A1 - Friederich, F. A1 - Globisch, B. A1 - Hechtfischer, G. A1 - Hens, K. A1 - Hübers, H.-W. A1 - Jelonnek, J. A1 - Jonuscheit, J. A1 - Keil, A. A1 - Kleine-Ostmann, T. A1 - Marquardt, E. A1 - Mayr, M. A1 - Nickel, H.-U. A1 - Nüßler, D. A1 - Peichl, M. A1 - Peters, O. A1 - Schür, J. A1 - Sprenger, T. A1 - Steiger, A. A1 - van Frank, S. A1 - Vieweg, N. A1 - Wilk, R. ED - Jonuscheit, J. ED - Marquardt, E. T1 - Terahertzsysteme und Anwendungsfelder N2 - Der Frequenzbereich der Terahertzwellen liegt im elektromagnetischen Spektrum zwischen den Mikrowellen und dem infraroten Licht – also etwa im Bereich von 0,1 bis 10 Terahertz (THz). Der VDI-Statusreport „Terahertzsysteme und Anwendungen“ stellt die unterschiedlichen Konzepte für Terahertzsysteme vor und zeigt Anwendungsbeispiele, bei denen die Terahertztechnik erfolgreich eingesetzt wird. Umfangreiche Literaturangaben ermöglichen eine intensivere Beschäftigung mit allen Themen des VDI-Statusreports. KW - Terahertzsysteme PY - 2020 UR - https://www.vdi.de/ueber-uns/presse/publikationen/details/terahertzsysteme-und-anwendungsfelder SP - 1 EP - 44 PB - Verein Deutscher Ingenieure (VDI) CY - Düsseldorf AN - OPUS4-50556 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Ressnig, A. A1 - Corbiere, T. A1 - Lunkenbein, T. A1 - Braun, Ulrike A1 - Willinger, M. G. A1 - Antonietti, M. T1 - Decomposition synthesis of tuneable, macroporous carbon foams from crystalline precursors via in situ templating N2 - A flexible, sustainable, one-step thermal decomposition route for the synthesis of hierarchical, heteroatom doped carbon foams is presented. Task-specific semi-organic crystals combine functions for three different purposes: the carbon and heteroatom source, a foaming agent (CO2) and an in situ generable template (NaCl). Insights to the decomposition pathway were gained through FTIR/MS coupled TGA and an ultrafast out-of-furnace heating procedure and the products were analysed with (HR)SEM/TEM, EELS, FTIR, and N2 sorption. The resulting macroporous carbon foams are excellent supports for metallic nanoparticles due to their hierarchical structure, high surface area and tuneable heteroatom contents. This was demonstrated for catalytically active copper or the magnetic CoNi alloy for water purification. KW - macroporous carbon KW - thermal decomposition KW - synthesize heteroatom KW - in situ template (NaCl) PY - 2014 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-318641 DO - https://doi.org/10.1039/c4ta03646h SN - 2050-7496 SN - 2050-7488 VL - 2 IS - 42 SP - 18076 EP - 18081 PB - RSC CY - London [u.a.] AN - OPUS4-31864 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Loges, A. A1 - Scholz, G. A1 - de Sousa Amadeu, Nader A1 - Jingjing, S. A1 - Emmerling, Franziska A1 - John, T. A1 - Paulus, B. A1 - Braun, T. T1 - Studies on the local structure of the F/OH site in topaz by magic angle spinning nuclear magnetic resonance and Raman spectroscopy N2 - he mutual influence of F and OH groups in neighboring sites in topaz (Al2SiO4(F,OH)2) was investigated using magic angle spinning nuclear magnetic resonance (MAS NMR) and Raman spectroscopy. The splitting of 19F and 1H NMR signals, as well as the OH Raman band, provides evidence for hydrogen bond formation within the crystal structure. Depending on whether a given OH group has another OH group or fluoride as its neighbor, two different hydrogen bond constellations may form: either OH···O···HO or F···H···O. The proton accepting oxygen was determined to be part of the SiO4 tetrahedron using 29Si MAS NMR. Comparison of the MAS NMR data between an OH-bearing and an OH-free topaz sample confirms that the 19F signal at −130 ppm stems from F− ions that take part in H···F bonds with a distance of ∼ 2.4 Å, whereas the main signal at −135 ppm belongs to fluoride ions with no immediate OH group neighbors. The Raman OH sub-band at 3644 cm−1 stems from OH groups neighboring other OH groups, whereas the sub-band at 3650 cm−1 stems from OH groups with fluoride neighbors, which are affected by H···F bridging. The integrated intensities of these two sub-bands do not conform to the expected ratios based on probabilistic calculations from the total OH concentration. This can be explained by a difference in the polarizability of the OH bond between the different hydrogen bond constellations or partial order or unmixing of F and OH, or a combination of both. This has implications for the quantitative interpretation of Raman data on OH bonds in general and their potential use as a probe for structural (dis-)order. No indication of tetrahedrally coordinated Al was found with 27Al MAS NMR, suggesting that the investigated samples likely have nearly ideal Al/Si ratios, making them potentially useful as high-density electron microprobe reference materials for Al and Si, as well as for F. KW - Topas KW - NMR KW - XRD PY - 2022 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-561863 DO - https://doi.org/10.5194/ejm-34-507-2022 SN - 1617-4011 VL - 34 IS - 5 SP - 507 EP - 521 PB - Copernicus Publications CY - Göttingen AN - OPUS4-56186 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Klöckner, P. A1 - Seiwert, B. A1 - Eisentraut, Paul A1 - Braun, Ulrike A1 - Reemtsma, T. A1 - Wagner, S. T1 - Characterization of tire and road wear particles from road runoffindicates highly dynamic particle properties N2 - Tire and road wear particles (TRWPs) are heteroagglomerates of tire rubber and other particles deposited on the road surface and one of the main contributors to non-exhaust emissions of automobile traffic. In this study, samples from road environments were analyzed for their TRWP contents and concentra- tions of eight organic tire constituents. TRWP concentrations were determined by quantifying Zn in the density fraction < 1.9 g/cm ³and by thermal extraction desorption-gas chromatography-mass spectrometry (TED-GC/MS) and the concentrations ranged from 3.7 to 480 mg TRWP/g. Strong and statistically signif- icant correlations with TRWPs were found for 2-hydroxybenzothiazole and 2-aminobenzothiazole, indi- cating that these substances may be suitable markers of TRWPs. The mass distribution of TRWPs in road dust suggests that the main mass fraction formed on roads consists of coarse particles ( > 100 μm). Data for a sedimentation basin indicate that the fine fraction ( < 50 μm) is preferentially transported by road runoffinto receiving waters. The size distribution and density data of TRWP gathered by three different quantitation approaches also suggest that aging of TRWPs leads to changes in their particle density. An improved understanding of the dynamics of TRWP properties is essential to assess the distribution and dissipation of this contaminant of emerging concern in the environment. KW - Tire Wear KW - Density separation KW - Microplastic KW - Urban PY - 2020 DO - https://doi.org/10.1016/j.watres.2020.116262 VL - 185 SP - 116262 PB - Elsevier Ltd. AN - OPUS4-51256 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Dittmann, Daniel A1 - Lucke, T. A1 - Ruhl, A. S. A1 - Winzenbacher, R. A1 - Jekel, M. A1 - Braun, Ulrike T1 - Untersuchungen zu biologischen, organischen und anorganischen Veränderungen granulierter Aktivkohlen während der Trinkwasseraufbereitung N2 - Untersuchungen zu biologischen, organischen und anorganischen Veränderungen granulierter Aktivkohlen während der Trinkwasseraufbereitung des Landeswasserversorgers Langenau. KW - Thermogravimetrie KW - Trinkwasser KW - Wasseraufbereitung KW - Aktivkohle PY - 2020 SN - 0083-6915 VL - 118 IS - 2 SP - 47 EP - 50 PB - Wiley-VCH Verlag GmbH & Co. KGaA AN - OPUS4-51434 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kittner, Maria A1 - Kerndorff, A. A1 - Ricking, M. A1 - Bednarz, M. A1 - Obermaier, N. A1 - Lukas, M. A1 - Asenova, M. A1 - Bordós, G. A1 - Eisentraut, Paul A1 - Hohenblum, P. A1 - Hudcova, H. A1 - Humer, F. A1 - István, T. G. A1 - Kirchner, M. A1 - Marushevska, O. A1 - Nemejcová, D. A1 - Oswald, P. A1 - Paunovic, M. A1 - Sengl, M. A1 - Slobodnik, J. A1 - Spanowsky, K. A1 - Tudorache, M. A1 - Wagensonner, H. A1 - Liska, I. A1 - Braun, U. A1 - Bannick, C. G. T1 - Microplastics in the Danube River Basin: A First Comprehensive Screening with a Harmonized Analytical Approach N2 - In this study, carried out within the Joint Danube Survey 4, a comprehensive microplastic screening in the water column within a large European river basin from its source to estuary, including major tributaries, was realized. The objective was to develop principles of a systematic and practicable microplastic monitoring strategy using sedimentation boxes for collection of suspended particulate matter followed by its subsequent analysis using thermal extraction desorption-gas chromatography/mass spectrometry. In total, 18 sampling sites in the Danube River Basin were investigated. The obtained suspended particulate matter samples were subdivided into the fractions of >100 μm and <100 μm and subsequently analyzed for microplastic mass contents. The results showed that microplastics were detected in all samples, with polyethylene being the predominant polymer with maximum contents of 22.24 μg/mg, 3.23 μg/mg for polystyrene, 1.03 μg/mg for styrene-butadiene-rubber, and 0.45 μg/mg for polypropylene. Further, polymers such as different sorts of polyester, polyacrylates, polylactide, and natural rubber were not detected or below the detection limit. Additional investigations on possible interference of polyethylene signals by algae-derived fatty acids were assessed. In the context of targeted monitoring, repeated measurements provide more certainty in the interpretation of the results for the individual sites. Nevertheless, it can be stated that the chosen approach using an integrative sampling and determination of total plastic content proved to be successful. KW - Thermal extraction desorption-gas chromatography/mass spectrometry (TED-GC/MS), monitoring KW - Microplastics KW - River KW - Suspended particulate matter (SPM) KW - Sedimentation box (SB) PY - 2022 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-551444 DO - https://doi.org/10.1021/acsestwater.1c00439 VL - 2 IS - 7 SP - 1174 EP - 1181 PB - ACS Publications AN - OPUS4-55144 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Braun, T. T1 - Evaluation of electric conductivity and mechanical load capacity of copper deposits for application in large winding components for electrical high-voltage machines made with cold spray additive manufacturing N2 - In line with the industrial trend of additive manufacturing, cold spray as a non-laser-based process is becoming increasingly important for many fields of application. For the evaluation of additive manufacturing of winding components made of copper for large electrical high-voltage machines, material and component properties such as electrical conductivity, mechanical load capacity and the component size that can be produced are of particular importance. In this context, the cold spray process offers advantages over laser-based additive manufacturing processes such as laser powder bed fusion (LPBF) or laser cladding by using the kinetic energy of the copper powder particles to generate particle cohesion. To investigate the electrical conductivity as well as the mechanical load capacity of cold spray parts, specimens were machined out of cold sprayed bulk copper deposits. The characteristic values were obtained with regard to the direction of deposition, which is defined by the direction of the robot’s movement. Thus, for the investigation of the component properties, specimens were provided that had been produced both longitudinally and transversely as well as orthogonally to the direction of deposition. The results of the investigations show that both the electrical conductivity and the mechanical load capacity of the specimen have a strong preferential direction of the specimen orientation with respect to the direction of deposition. Furthermore, it could be shown that by increasing the deposition height, there is an increasing oxygen content in the sample material, combined with increasingly significant defect networks. These effects have a negative impact on the electrical conductivity as well as on the mechanical load capacity. As a conclusion, further need for investigation is identified in the optimization of the process parameters as well as in the deposition strategy for the additive manufacturing of large-volume components with cold spray. T2 - ITSC 2022 CY - Vienna, Austria DA - 04.05.2022 KW - Cold Spray KW - Copper powder particles KW - Electrical conductivity KW - Large electrical high-voltage machine PY - 2022 AN - OPUS4-56127 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Braun, T. A1 - Uhlmann, E. A1 - Häcker, Ralf A1 - Jäger, M. A1 - Rauch, H. A1 - Kondas, J. A1 - Brach, K. A1 - Singh, R. T1 - Evaluation of electric conductivity and mechanical load capacity of copper deposits for application in large winding components for electrical high-voltage machines made with cold spray additive manufacturing N2 - In line with the industrial trend of additive manufacturing, cold spray as a non-laser-based process is becoming increasingly important for many fields of application. For the evaluation of additive manufacturing of winding components made of copper for large electrical high-voltage machines, material and component properties such as electrical conductivity, mechanical load capacity and the component size that can be produced are of particular importance. In this context, the cold spray process offers advantages over laser-based additive manufacturing processes such as laser powder bed fusion (LPBF) or laser cladding by using the kinetic energy of the copper powder particles to generate particle cohesion. To investigate the electrical conductivity as well as the mechanical load capacity of cold spray parts, specimens were machined out of cold sprayed bulk copper deposits. The characteristic values were obtained with regard to the direction of deposition, which is defined by the direction of the robot’s movement. Thus, for the investigation of the component properties, specimens were provided that had been produced both longitudinally and transversely as well as orthogonally to the direction of deposition. The results of the investigations show that both the electrical conductivity and the mechanical load capacity of the specimen have a strong preferential direction of the specimen orientation with respect to the direction of deposition. Furthermore, it could be shown that by increasing the deposition height, there is an increasing oxygen content in the sample material, combined with increasingly significant defect networks. These effects have a negative impact on the electrical conductivity as well as on the mechanical load capacity. As a conclusion, further need for investigation is identified in the optimization of the process parameters as well as in the deposition strategy for the additive manufacturing of large-volume components with cold spray. T2 - ITSC 2022 CY - Wien, Austria DA - 04.05.2022 KW - Cold Spray KW - Electrical conductivity KW - Copper powder particles KW - Large electrical high-voltage machine PY - 2022 SP - 1 EP - 7 AN - OPUS4-56108 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Barretto, T. A1 - Gentes, S. A1 - Braun, J. A1 - Averin, Anton A1 - Lecompagnon, Julien A1 - Stroncik, N. T1 - Automated non-destructive internal corrosion detection on radioactive drums (ZIKA) N2 - The aim of the ZIKA research project, funded by the BMBF funding program FORKA (FKZ:15S9446 A-C), is the automated detection of internal corrosion of radioactive drums using non-destructive testing (NDT). The newly gained findings will be combined with research results from the previous project EMOS (FKZ:15S9420), which dealt with the external damage of drums. Using NDT, internal corrosion and possible internal sources of damage can be identified before they become a safety-relevant issue. However, if internally sourced damages can be seen externally, the integrity of the damaged drum is no longer guaranteed, which has significant consequences. Therefore, early detection before integrity failure is of particular importance for interim storage facilities with low- and medium-level radioactive waste drums. T2 - Kerntechnik 2024 CY - Leipzig, Germany DA - 11.06.2024 KW - Corrosion detection KW - Non-destructive testing KW - Automated inspection system PY - 2024 SP - 1 EP - 5 AN - OPUS4-60322 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Wang, L. A1 - Stebbings, R. A1 - Gaigalas, A.K. A1 - Sutherland, J. A1 - Kammel, M. A1 - John, M. A1 - Roemer, B. A1 - Kuhne, Maren A1 - Schneider, Rudolf A1 - Braun, M. A1 - Engel, A. A1 - Dikshit, D. A1 - Abbasi, F. A1 - Marti, G.E. A1 - Sassi, M. A1 - Revel, L. A1 - Kim, S.K. A1 - Baradez, M.-O. A1 - Lekishvili, T. A1 - Marshall, D. A1 - Whitby, L. A1 - Jing, W. A1 - Ost, V. A1 - Vonsky, M. A1 - Neukammer, J. T1 - Quantification of cells with specific phenotypes II: Determination of CD4 expression level on reconstituted lyophilized human PBMC labelled with anti-CD4 FITC antibody N2 - This report focuses on the characterization of CD4 expression level in terms of equivalent number of reference fluorophores (ERF). Twelve different flow cytometer platforms across sixteen laboratories were utilized in this study. As a first step the participants were asked to calibrate the fluorescein isothiocyanate (FITC) channel of each flow cytometer using commercially available calibration standard consisting of five populations of microspheres. Each population had an assigned value of equivalent fluorescein fluorophores (EFF denotes a special case of the generic term ERF with FITC as the reference fluorophore). The EFF values were assigned at the National Institute of Standards and Technology (NIST). A surface-labelled lyophilized cell preparation was provided by the National Institute of Biological Standards and Control (NIBSC), using human peripheral blood mononuclear cells (PBMC) pre-labeled with a FITC conjugated anti-CD4 monoclonal antibody. Three PBMC sample vials, provided to each participant, were used for the CD4 expression analysis. The PBMC are purported to have a fixed number of surface CD4 receptors. On the basis of the microsphere calibration, the EFF value of the PBMC samples was measured to characterize the population average CD4 expression level of the PBMC preparations. Both the results of data analysis performed by each participant and the results of centralized analysis of all participants' raw data are reported. Centralized analysis gave a mean EFF value of 22,300 and an uncertainty of 750, corresponding to 3.3% (level of confidence 68%) of the mean EFF value. The next step will entail the measurement of the ERF values of the lyophilized PBMC stained with labels for other fluorescence channels. The ultimate goal is to show that lyophilized PBMC is a suitable biological reference cell material for multicolor flow cytometry and that it can be used to present multicolor flow cytometry measurements in terms of ABC (antibodies bound per cell) units. KW - Surface labelled lyophilized PBMC KW - CD4 expression level KW - FITC KW - Equivalent fluorescein fluorophore (EFF) KW - Quantitative flow cytometry KW - Calibration KW - Standard measurement procedure KW - Measurement uncertainty KW - Reference cell material PY - 2015 DO - https://doi.org/10.1002/cyto.a.22634 SN - 0196-4763 SN - 1552-4922 SN - 1552-4930 VL - 87 IS - 3 SP - 254 EP - 261 PB - Wiley-Liss CY - Hoboken, NJ AN - OPUS4-32981 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Stebbings, R. A1 - Wang, L. A1 - Sutherland, J. A1 - Kammel, M. A1 - Gaigalas, A.K. A1 - John, M. A1 - Roemer, B. A1 - Kuhne, Maren A1 - Schneider, Rudolf A1 - Braun, M. A1 - Engel, A. A1 - Dikshit, D.K. A1 - Abbasi, F. A1 - Marti, G.E. A1 - Sassi, M.P. A1 - Revel, L. A1 - Kim, S.-K. A1 - Baradez, M.-O. A1 - Lekishvili, T. A1 - Marshall, D. A1 - Whitby, L. A1 - Jing, W. A1 - Ost, V. A1 - Vonsky, M. A1 - Neukammer, J. T1 - Quantification of cells with specific phenotypes I: Determination of CD4+ cell count per microliter in reconstituted lyophilized human PBMC prelabeled with anti-CD4 FICT antibody N2 - A surface-labeled lyophilized lymphocyte (sLL) preparation has been developed using human peripheral blood mononuclear cells prelabeled with a fluorescein isothiocyanate conjugated anti-CD4 monoclonal antibody. The sLL preparation is intended to be used as a reference material for CD4+ cell counting including the development of higher order reference measurement procedures and has been evaluated in the pilot study CCQM-P102. This study was conducted across 16 laboratories from eight countries to assess the ability of participants to quantify the CD4+ cell count of this reference material and to document cross-laboratory variability plus associated measurement uncertainties. Twelve different flow cytometer platforms were evaluated using a standard protocol that included calibration beads used to obtain quantitative measurements of CD4+ T cell counts. There was good overall cross-platform and counting method agreement with a grand mean of the laboratory calculated means of (301.7 ± 4.9) µL-1 CD4+ cells. Excluding outliers, greater than 90% of participant data agreed within ±15%. A major contribution to variation of sLL CD4+ cell counts was tube to tube variation of the calibration beads, amounting to an uncertainty of 3.6%. Variation due to preparative steps equated to an uncertainty of 2.6%. There was no reduction in variability when data files were centrally reanalyzed. Remaining variation was attributed to instrument specific differences. CD4+ cell counts obtained in CCQM-P102 are in excellent agreement and show the robustness of both the measurements and the data analysis and hence the suitability of sLL as a reference material for interlaboratory comparisons and external quality assessment. KW - CD4+ cell counting KW - Relative concentration measurement KW - Lyophilized cells KW - Flow cytometry KW - Standard measurement procedure KW - Measurement of uncertainty KW - Human immunodeficiency virus-1 KW - Acquired immunodeficiency syndrome KW - Reference material PY - 2015 DO - https://doi.org/10.1002/cyto.a.22614 SN - 0196-4763 SN - 1552-4922 SN - 1552-4930 VL - 87 IS - 3 SP - 244 EP - 253 PB - Wiley-Liss CY - Hoboken, NJ AN - OPUS4-32847 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Meißner, G. A1 - Dirican, D. A1 - Jäger, Christian A1 - Braun, T. A1 - Kemnitz, E. T1 - Et3GeH versus Et3SiH: controlling reaction pathways in catalytic C–F bond activations at a nanoscopic aluminum chlorofluoride† N2 - Catalytic C–F bond activation reactions of mono- and polyfluoroalkanes at Lewis acidic amorphous aluminum chlorofluoride (ACF) are presented. The hydrogen sources Et3GeH or Et3SiH control the selectivity of the conversions. The immobilization of Et3GeH at ACF resulted in catalytic dehydrohalogenation reactions to yield olefins under very mild conditions. In contrast, if Et3SiH is immobilized at ACF, C–C coupling occured and the formation of Friedel–Crafts products was observed. MAS NMR spectroscopic studies revealed information about the surface binding of the substrates. KW - Vapor-phase hydrofluorination KW - Carbon-fluorine bonds KW - Vinyl fluoride KW - Phosphine-ligands KW - Room-temperature KW - Building-blocks KW - Etal-complexes KW - Germylium ions KW - Lewis-acids KW - Hydrodefluorination PY - 2017 DO - https://doi.org/10.1039/c7cy00845g SN - 2044-4753 SN - 2044-4761 VL - 7 IS - 15 SP - 3348 EP - 3354 PB - The Royal Society of Chemistry AN - OPUS4-41836 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Yegen, E. A1 - Zimmermann, Uwe A1 - Unger, Wolfgang A1 - Braun, T. T1 - C-F bond cleavage during derivatization reactions of amino groups with TFBA and PFB at plasma-processed organic surfaces? N2 - Chemical derivatization XPS is used for the quantitative determination of amines at conventional organic surfaces, and it is also applied to plasma-processed aminated surfaces. When using TFBA and PFB as derivatization reagents for tagging primary amino groups, unexpected fluorine species were observed in the second case. The existence of reaction pathways other than those expected for amine derivatization with PFB or TFBA has to be assumed. This phenomenon is tentatively interpreted as the result of C—F bond cleavage during derivatization reactions of TFBA and PFB at plasma-polymerized allylamine and other plasma-processed aminated surfaces. As a consequence, quantification procedures based on derivatization by PFB or TFBA will underestimate amine surface concentrations. KW - Aminated surfaces KW - Chemical derivatization KW - ESCA KW - Plasma polymers KW - XPS PY - 2009 DO - https://doi.org/10.1002/ppap.200800100 SN - 1612-8850 SN - 1612-8869 VL - 6 IS - 1 SP - 11 EP - 16 PB - Wiley-VCH Verl. CY - Weinheim AN - OPUS4-18686 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Perez, R.M. A1 - Sandler, J.K.W. A1 - Altstädt, V. A1 - Hoffmann, T. A1 - Pospiech, D. A1 - Artner, J. A1 - Ciesielski, M. A1 - Döring, M. A1 - Braun, Ulrike A1 - Schartel, Bernhard ED - Schartel, Bernhard T1 - Flame retardant epoxy resin system for liquid composite moulding applications KW - Epoxy resin KW - Fire retardancy PY - 2007 SN - 978-3-8334-8873-3 SP - 69 EP - 84 PB - Books on Demand GmbH CY - Norderstedt AN - OPUS4-17627 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Perez, R.M. A1 - Sandler, J.K.W. A1 - Altstädt, V. A1 - Hoffmann, T. A1 - Pospiech, D. A1 - Ciesielski, M. A1 - Döring, M. A1 - Braun, Ulrike A1 - Knoll, Uta A1 - Schartel, Bernhard T1 - Effective halogen-free flame retardants for carbon fibre-reinforced epoxy composites N2 - DOPO-based flame retardants with tailored chemical structures are proposed for carbon fibre reinforced epoxy composites. Critical properties related to the fracture toughness are maintained, effectively allowing the use of such compounds in composites for demanding applications. KW - Fire retardancy KW - DOPO KW - Epoxy resin KW - LOI KW - UL94 PY - 2006 DO - https://doi.org/10.1007/s10853-006-0134-4 SN - 0022-2461 SN - 1573-4803 VL - 41 IS - 15 SP - 4981 EP - 4984 PB - Springer Science + Business Media B.V. CY - New York, USA AN - OPUS4-12641 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Braun, Ulrike A1 - Knoll, Uta A1 - Schartel, Bernhard A1 - Hoffmann, T. A1 - Pospiech, D. A1 - Artner, J. A1 - Ciesielski, M. A1 - Döring, M. A1 - Perez-Graterol, R. A1 - Sandler, J.K.W. A1 - Altstädt, V. T1 - Novel Phosphorus-Containing Poly(ether sulfone)s and Their Blends with an Epoxy Resin: Thermal Decomposition and Fire Retardancy N2 - Summary: The decomposition of novel phosphorus-containing poly(oxyphenylene-sulfonyl-phenylene-oxy-diphenyl phenylene phosphine oxide) (PSU_I), 2,5-dihydroxy-1-biphenylene-phosphine oxide based polysulfone (PSU_II), poly(sulfonyl-diphenylphenylene phosphonate) (PSU_P) and bisphenol A-based polysulfone (PSU) is studied. The influence of the chemical structure, charring and phosphorus release is discussed based on the mass loss, kinetics and products. The pyrolysis and fire behaviour of blends with epoxy resin (EP) are studied. For EP-PSU_II, phosphorus initiates water elimination and changes the decomposition pathway of EP. The fire behaviour of EP-PSU shows some improvements, whereas the heat release rate is crucially reduced for EP-PSU_II due to simultaneous char formation and flame inhibition. KW - Epoxy KW - Flame retardance KW - High performance polymers KW - Polysulfones KW - Thermogravimetric analysis (TGA) PY - 2006 DO - https://doi.org/10.1002/macp.200600182 SN - 1022-1352 SN - 1521-3935 VL - 207 IS - 16 SP - 1501 EP - 1514 PB - Wiley-VCH Verl. CY - Weinheim AN - OPUS4-12650 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Braun, Ulrike A1 - Balabanovich, Aliaksandr A1 - Schartel, Bernhard A1 - Knoll, Uta A1 - Artner, J. A1 - Ciesielski, M. A1 - Döring, M. A1 - Perez, R. A1 - Sandler, J.K.W. A1 - Altstädt, V. A1 - Hoffmann, T. A1 - Pospiech, D. T1 - Influence of the oxidation state of phosphorus on the decomposition and fire behaviour of flame-retarded epoxy resin composites N2 - A systematic and comparative evaluation of the pyrolysis of halogen-free flame-retarded epoxy resins containing phosphine oxide, phosphinate, phosphonate, and phosphate (phosphorus contents around 2.6 wt.%) and the fire behaviour of their carbon fibre composites is presented. Decomposition pathways are proposed based on the thermal analysis (TG), TG coupled with evolved gas analysis (TG-FTIR), kinetics and analysis of the residue with FTIR and XPS. All organophosphorus-modified hardeners containing phenoxy groups lead to a reduced decomposition temperature and mass loss step for the main decomposition of the cured epoxy resin. With increasing oxidation state of the phosphorus the thermally stable residue increases, whereas the release of phosphorus-containing volatiles decreases. The flammability of the composites was investigated with LOI and UL 94 and the fire behaviour for forced-flaming conditions with cone calorimeter tests performed using different irradiations. The flame retardancy mechanisms are discussed. With increasing oxidation state of the phosphorus additional charring is observed, whereas the flame inhibition, which plays the more important role for the performance of the composites, decreases. The processing and the mechanical performance (delamination resistance, flexural properties and interlaminar bonding strength) of the fibre-reinforced composites containing phosphorus were maintained at a high level and, in some cases, even improved. The potential for optimising flame retardancy while maintaining mechanical properties is highlighted in this study. KW - Fire retardant KW - Composites KW - Organophosphorus-containing epoxy resin PY - 2006 DO - https://doi.org/10.1016/j.polymer.2006.10.022 SN - 0032-3861 SN - 1873-2291 VL - 47 IS - 26 SP - 8495 EP - 8508 PB - Springer CY - Berlin AN - OPUS4-14054 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Perez, R.M. A1 - Sandler, J.K.W. A1 - Altstädt, V. A1 - Hoffmann, T. A1 - Pospiech, D. A1 - Ciesielski, M. A1 - Döring, M. A1 - Braun, Ulrike A1 - Balabanovich, Aliaksandr A1 - Schartel, Bernhard T1 - Novel phosphorus-modified polysulfone as a combined flame retardant and toughness modifier for epoxy resins N2 - A novel phosphorus-modified polysulfone (P-PSu) was employed as a combined toughness modifier and a source of flame retardancy for a DGEBA/DDS thermosetting system. In comparison to the results of a commercially available polysulfone (PSu), commonly used as a toughness modifier, the chemorheological changes during curing measured by means of temperature-modulated DSC revealed an earlier occurrence of mobility restrictions in the P-PSu-modified epoxy. A higher viscosity and secondary epoxy-modifier reactions induced a sooner vitrification of the reacting mixture; effects that effectively prevented any phase separation and morphology development in the resulting material during cure. Thus, only about a 20% increase in fracture toughness was observed in the epoxy modified with 20 wt.% of P-PSu, cured under standard conditions at 180 °C for 2 h. Blends of the phosphorus-modified and the standard polysulfone (PSu) were also prepared in various mixing ratios and were used to modify the same thermosetting system. Again, no evidence for phase separation of the P-PSu was found in the epoxy modified with the P-PSu/PSu blends cured under the selected experimental conditions. The particular microstructures formed upon curing these novel materials are attributed to a separation of PSu from a miscible P-PSu–epoxy mixture. Nevertheless, the blends of P-PSu/PSu were found to be effective toughness/flame retardancy enhancers owing to the simultaneous microstructure development and polymer interpenetration. KW - Flame retardants KW - Phosphorus-modified polysulfone KW - Fracture toughness PY - 2007 SN - 0032-3861 SN - 1873-2291 VL - 48 IS - 3 SP - 778 EP - 790 PB - Springer CY - Berlin AN - OPUS4-14515 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Schartel, Bernhard A1 - Balabanovich, Aliaksandr A1 - Braun, Ulrike A1 - Knoll, Uta A1 - Artner, J. A1 - Ciesielski, M. A1 - Döring, M. A1 - Perez, R. A1 - Sandler, J.K.W. A1 - Altstädt, V. A1 - Hoffmann, T. A1 - Pospiech, D. T1 - Pyrolysis of Epoxy Resins and Fire Behavior of Epoxy Resin Composites Flame-Retarded with 9,10-Dihydro-9-oxa-10-phosphaphenanthrene-10-oxide Additives N2 - The pyrolysis of an epoxy resin and the fire behavior of corresponding carbon fiber-reinforced composites, both flame-retarded with either 10-ethyl-9,10-dihydro-9-oxa-10-phosphaphenanthrene 10-oxide or 1,3,5-tris[2-(9,10-dihydro-9-oxa-10-phosphaphenanthrene 10-oxide-10-)ethyl]1, 3,5-triazine-2,4,6(1H,3H,5H)-trione, are investigated. The different fire retardancy mechanisms are discussed, and their influence on the fire properties assessed, in particular for flammability (limiting oxygen index, UL 94) and developing fires (cone calorimeter with different external heat fluxes of 35, 50, and 70 kW m-2). Adding the flame retardants containing 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide affects the fire behavior by both condensed phase and gas phase mechanisms. Interactions between the additives and the epoxy resin result in a change in the decomposition pathways and an increased char formation. The release of phosphorous products results in significant flame inhibition. The fire properties achieved are thus interesting with respect to industrial exploration. KW - Flame retardance KW - Thermosets KW - Composites KW - Thermogravimetric analysis (TGA) KW - Pyrolysis KW - High performance polymers KW - Epoxy resin PY - 2007 SN - 0021-8995 SN - 1097-4628 VL - 104 IS - 4 SP - 2260 EP - 2269 PB - Wiley InterScience CY - Hoboken, NJ AN - OPUS4-14573 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Perez, R.M. A1 - Sandler, J.K.W. A1 - Altstädt, V. A1 - Hoffmann, T. A1 - Pospiech, D. A1 - Artner, J. A1 - Ciesielski, M. A1 - Döring, M. A1 - Balabanovich, Aliaksandr A1 - Knoll, Uta A1 - Braun, Ulrike A1 - Schartel, Bernhard T1 - Novel Phosphorus-containing Hardeners with Tailored Chemical Structures for Epoxy Resins: Synthesis and Cured Resin Properties N2 - A comparative evaluation of systematically tailored chemical structures of various phosphorus-containing aminic hardeners for epoxy resins was carried out. In particular, the effect of the oxidation state of the phosphorus in the hardener molecule on the curing behavior, the mechanical, thermomechanical, and hot-wet properties of a cured bifunctional bisphenol-A based thermoset is discussed. Particular attention is paid to the comparative pyrolysis of neat cured epoxy resins containing phosphine oxide, phosphinate, phosphonate, and phosphate (with a phosphorus content of about 2.6 wt %) and of the fire behavior of their corresponding carbon fiber-reinforced composites. Comparatively faster curing thermosetting system with an enhanced flame retardancy and adequate processing behavior can be formulated by taking advantage of the higher reactivity of the phosphorus-modified hardeners. For example, a combination of the high reactivity and of induced secondary crosslinking reactions leads to a comparatively high Tg when curing the epoxy using a substoichiometric amount of the phosphinate-based hardener. The overall mechanical performance of the materials cured with the phosphorus-containing hardeners is comparable to that of a 4,4-DDS-cured reference system. While the various phosphorus-containing hardeners in general provide the epoxy-based matrix with enhanced flame retardancy properties, it is the flame inhibition in the gas phase especially that determines the improvement in fire retardancy of carbon fiber-reinforced composites. In summary, the present study provides an important contribution towards developing a better understanding of the potential use of such phosphorus-containing compounds to provide the composite matrix with sufficient flame retardancy while simultaneously maintaining its overall mechanical performance on a suitable level. KW - Flame retardance KW - Organo-phosphorus compounds KW - Fracture toughness PY - 2007 SN - 0021-8995 SN - 1097-4628 VL - 105 IS - 5 SP - 2744 EP - 2759 PB - Wiley InterScience CY - Hoboken, NJ AN - OPUS4-15071 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -