TY - CONF A1 - Stroh, Julia T1 - High resolution in situ monitoring of the initial cement hydration influenced by organic admixtures N2 - Numerous admixtures are used in the building practice to customize the properties of the cement paste during application. The influences of admixtures on the course of cement hydration and formation of hydrate phases have to be considered. Polycarboxylate ether (PCE) based polymeric superplasticizers (SPs) are known to retard the setting of the cement paste. The extent of the retardation differs depending on the molecular structure of the SP. Additionally, the presence of a stabilizing agent (SA) in the cement paste has a retarding side effect on the setting. The initial cement hydration processes and the detailed mechanisms of the retardation influenced by PCEs, as well as their interactions with particular SAs, are insufficiently understood. Up to now, only the results of phenomenological studies were taken into account to describe this retardation process. A detailed structure analysis monitoring the change of the phase composition during the hydration was never applied. Both SP and SA affect the adsorption of the sulphate ions on the clinker particles, causing changes in the formation of ettringite during the initial hydration, and are therefore a crucial part of the setting process itself. Here, the initial hydration of cement influenced by the interaction of SP and SA was monitored in situ by synchrotron X-ray diffraction. The high time resolution of the measurements allowed a continuous detection of the hydrates formed. The hydration was followed from the starting point of water addition and for couple of hours afterwards. The hydration of the levitated cement pellets containing starch as SA was initialized by adding aqueous solutions of different commercial SPs. Changes in the ettringite formation were detected in comparison to the reference hydration of pure cement. T2 - Early Age Concrete: From the Research Lab to the Construction Site CY - Tomsk, Russia DA - 02.06.2015 KW - Portland cement KW - Initial hydration KW - Superplasticizer KW - Stabilizer KW - Synchrotron XRD PY - 2015 AN - OPUS4-35470 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Zientek, Nicolai T1 - Automated data evaluation and modeling of simultaneous 19F-1H medium resolution NMR spectra for online reaction monitoring N2 - The development of innovative medium resolution NMR spectrometers (MR-NMR) is remarkable due to their possible applications in quality control, education, or process monitoring. The use of compact permanent magnets allows to employ NMR devices in an industrial environment without high maintenance requirements and without the need for cryogenic liquids. A benchtop 43 MHz MR-NMR spectrometer was used for reaction monitoring. Quasi-simultaneous proton and fluorine NMR spectra were acquired. Automatic data pretreatment and evaluation methods were applied and compared to quantitative 500 MHz HR-NMR spectroscopy T2 - Quantitative NMR Methods for Reaction and Process Monitoring (NMRPM) Symposium CY - Kaiserslautern, Germany DA - 15.01.2015 KW - Online NMR Spectroscopy KW - 1H-NMR KW - 19F-NMR KW - Reaction Monitoring KW - Benchtop NMR Spectroscopy KW - Process Analytical Technology PY - 2015 AN - OPUS4-36148 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Heck, Christian T1 - Gold nanolenses on DNA origami substrates for surface-enhanced Raman scattering N2 - Surface-enhanced Raman scattering (SERS) exploits the enhancement of electromagnetic fields in close vicinity of plasmonic nanostructures, enabling characterization of analytes at the single-molecule level. The nanometer-scale spatial arrangement of plasmonic metal nanoparticles and analyte molecules has a significant effect on the observed signal enhancements and represents a great challenge in this technique. In our work, DNA origami is used as platform for precise positioning of gold nanoparticles (AuNPs). Especially high sensitivities are expected for gold nanolenses (AuNLs), consisting of rows of three or more differently-sized AuNPs. We assembled different AuNL designs and determined respective SERS enhancement factors by collecting Raman spectra from single AuNLs. Finite difference time domain calculations estimate attainable electromagnetic field enhancements. Ultimately, we aim to develop a versatile platform for various SERS applications. T2 - DNA meets Plasmonics Konferenz CY - Bad Honnef, Germany DA - 07.12.2015 KW - DNA origami KW - SERS KW - Plasmonics PY - 2015 AN - OPUS4-35906 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Isleyen, A. T1 - A joint research project for the sustainable production of certified matrix reference materials for environmental analysis N2 - This project aims to develop capacity to produce certified reference materials (CRMs) for environmental analysis by transferring know-how between the partners and combining their skills to focus on environmental CRM production. The production process includes good manufacturing practices for processing materials, method development, the validation and application of homogeneity, stability and characterisation tests, the calculation of individual uncertainties (between-unit inhomogeneity, long term stability, characterisation) and combination of uncertainties to determine overall uncertainty of the matrix reference materials. An inter laboratory comparison registered as a EURAMET project is set as the ultimate project outcome, confirming the partners’ capabilities in applying newly acquired skills. T2 - BERM-14 CY - National Harbor, Maryland, USA DA - 11.10.2015 KW - Reference material KW - Priority pollutants KW - Toxic metals KW - PFOS KW - PFOA PY - 2015 AN - OPUS4-45251 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Heinrich, Thomas T1 - Coupled molecular switching processes in ordered mono- and multilayers of stimuli-responsive rotaxanes on gold surfaces N2 - Interfaces provide the structural basis for function as, for example, encountered in nature in the membrane-embedded photosystem or in technology in solar cells. Synthetic functional multilayers of molecules cooperating in a coupled manner can be fabricated on surfaces through layer-by-layer self-assembly. Ordered arrays of stimuli-responsive rotaxanes undergoing well-controlled axle shuttling are excellent candidates for coupled mechanical motion. Such stimuli-responsive surfaces may help integrating synthetic molecular machines in larger systems exhibiting even macroscopic effects or generating mechanical work from chemical energy through cooperative action. The present work demonstrates the successful deposition of ordered mono- and multilayers of chemically switchable rotaxanes on gold surfaces. For the first time, rotaxane mono- and multilayers are shown to reversibly switch in a coupled manner between two ordered states as revealed by linear dichroism effects in angle-resolved NEXAFS spectra. Such a concerted switching process is observed only when the surfaces are well packed, while less densely packed surfaces lacking lateral order do not exhibit such effects. T2 - SupraChem 2015 CY - Berlin, Germany DA - 22.02.2015 KW - NEXAFS KW - Rotaxanes KW - Molecular machines KW - XPS KW - ToF-SIMS KW - AFM PY - 2015 AN - OPUS4-42800 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Isleyen, A. T1 - A Joint Research Project for the Sustainable Production of Certified Matrix Reference Materials for Environmental Analysis N2 - Reliable analysis of chemical indicators in water, sediment and soil samples for the purpose of environmental pollution assessment poses one of the greatest analytical challenges, having in mind the complexity of sample matrix and low concentrations of pollutants. Organics (pesticides, PAHs, PCBs, etc.) and heavy metals (Hg, Cd, Ni, Pb and As) represent target parameters. Laboratories performing sampling and tests in this field regulated by respective EU directives, need strong support in terms of providing them with appropriate matrix CRMs enabling the process of quality control. NMIs and DIs with proven metrological capabilities for the production and certification of such materials are necessary for the provision of quality data. This project is aiming to develop capacity to produce CRMs for environmental analysis by transferring the theoretical and practical know-how between the partners and combining their skills to focus on environmental CRM production in accordance with ISO Guide 34. Production process includes good manufacturing practices for processing materials, method development and validation for homogeneity, stability and characterisation tests, characterisation of selected analytes together with additional information about matrix constituents, the calculation of individual uncertainties (between units inhomogeneity, long term stability, characterisation) and combination of uncertainties to determine overall uncertainty of the matrix reference materials. Inter laboratory comparison registered as EURAMET project is set as the ultimate project outcome, confirming the partners’ capabilities in applying newly acquired skills. T2 - BERM-14 International Symposium on Biological and Environmental Reference Materials CY - National Harbor, Maryland, USA DA - 12.10.2015 KW - Soil KW - Heavy metal KW - Environment KW - CRM KW - PFOA KW - PFOS PY - 2015 AN - OPUS4-38800 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Dippong, Martin T1 - Fraunhofer Life Science Day N2 - Their high affinity, selectivity and specificity make monoclonal antibodies (mAbs) very important tools in research, diagnostics and therapy. The production of mAbs is routinely performed by hybridoma technique. Hybridomas are generated by fusing antibody-producing B cells with indefinitely proliferating myeloma cells. Both, cell fusion and the indispensable identification and isolation of the desired antibody-producing hybridoma clone is still far from being trivial. We describe a novel method that should help to optimize the cell fusion, and the screening for antibody-secreting hapten-specific hybridoma cells by using fluorescence activated cell sorting and single-cell fusion. Hybridoma cells specific for a hapten were incubated with a hapten-peroxidase conjugate (hapten-HRP), which was subsequently incubated with a fluorophore-labeled polyclonal anti-peroxidase antibody (anti-HRP-Alexa Fluor® 488). To characterize the expression of membrane-bound immunoglobulin G (IgG) a fluorophore-labeled anti-mouse IgG antibody (anti-IgG-Alexa Fluor® 647) was used. Successful staining was verified by confocal laser scanning microscopy (CLSM). We show that it is possible to specifically label hapten-specific hybridoma cells. It should also be possible to use this labelling approach for the isolation of hapten-specific B cells from the spleen and use these cells for single-cell fusion. Parallelized cell fusion chips were developed to increase fusion efficiencies. T2 - Fraunhofer Life Science Day 2015 CY - Leipzig, Germany DA - 03.07.2015 KW - Single-cell fusion KW - Hybridoma KW - Monoclonal antibodies PY - 2015 AN - OPUS4-37872 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Lehmann, Andreas T1 - Matrixeinflüsse bei der Bestimmung von Arzneimittelrückständen mittels LC-MS/MS in Oberflächenwasserproben bei Konzentrationen im ppt-Bereich N2 - Zur Bestimmung von Arzneimittelrückständen in Oberflächengewässern wird häufig die LC-MS/MS als Methode der Wahl eingesetzt. Obwohl sich dieses Nachweisverfahren durch eine hohe Empfindlichkeit und Selektivität auszeichnet, gibt es vor allem bei geringen Substanzkonzentrationen häufig störende Einflüsse durch Matrixeffekte. Diese Matrixeffekte können unterschiedliche Ursachen haben. Einige Matrixeffekte werden am Beispiel des Wirkstoffs Carbamazepin erläutert. Carbamazepin wird durch Kläranlagen nur partiell aus dem Abwasser entfernt und ist im Spurenbereich auch noch im Trinkwasser nachzuweisen. Wenn für die LC-MS/MS wasserbasierte Anteile in der mobilen Phase genutzt werden, befinden sich trotz Verwendung einer Labor-Reinstwasseranlage in der mobilen Phase noch kleinste Konzentrationen von Carbamazepin, welche einen Blindwert im unteren ppt-Bereich verursachen. Weitere Matrixeffekte treten durch die unterschiedliche Qualität der Oberflächenwasserproben auf. Koelutionen von weiteren Inhaltstoffen zeitgleich mit dem Zielanalyten führen zu einer Diskriminierung des Meßsignals. Verbindungen, die den gleichen Massenübergang bei nahezu identischer Retentionszeit zeigen, erfordern eine reproduzierbare chromatographische Vortrennung oder die Wahl einer alternativen HPLC-Säule. T2 - ANAKON 2015 CY - Graz, Austria DA - 23.03.2015 KW - Arzneimittelrückstände in Oberflächenwasserproben KW - HPLC-MS/MS KW - Massenspektrometrie KW - Carbamazepin PY - 2015 AN - OPUS4-35793 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Priebe, Nsesheye Susan T1 - A modified cementitious system for sub-Saharan Africa N2 - Supplementary cementitious materials (SCMs) are largely used all over the world. The leading SCMs are fly ash (FA) and slag. However, such materials originate from industries that are not well established in sub-Saharan Africa (SSA). Therefore, it becomes extremely challenging and expensive to build up sustainable cement and concrete. For SSA, agriculture is one of the leading economic sectors. Agricultural by-products such as rice husk ash (RHA), can be a potential binder material beneficial for use in a cementitious system. RHA combined with limestone filler (LSF) is an option that can be practised for rice producing countries in Africa. T2 - PhD Day CY - Berlin, Germany DA - 14.07.2015 KW - Supplementary cementitious materials KW - Rice husk as KW - Cement KW - Concrete KW - Sustainable PY - 2015 N1 - Geburtsname von Priebe, Nsesheye Susan: Msinjili, N. S. - Birth name of Priebe, Nsesheye Susan: Msinjili, N. S. AN - OPUS4-41029 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hoffmann, Holger T1 - An insight into fractionated environmental water samples to understand matrix effects in immunoassays N2 - N4-acetyl-SMX is the most important cross-reacting compound for the SMX-ELISA with concentrations of 1064 - 2488 ng/L in influent wastewater and 40 - 160 ng/L in effluent wastewater. The ELISAgrams for estrone show less interfering signals than for SMX. ELISAgrams of SMX and estrone display in effluent wastewater more interfering signals than in influent wastewater. T2 - ANAKON CY - Graz, Austria DA - 23.03.2016 KW - Sulfamethoxazole KW - Estrone KW - LC-ELISA KW - Matrix effects PY - 2015 AN - OPUS4-35792 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -