TY - CONF A1 - Gawek, Marcel A1 - Madkour, Sherif A1 - Hertwig, Andreas A1 - Schönhals, Andreas T1 - Growth Kinetics and Molecular Mobility of Irreversibly Adsorbed Layers in Thin Polymer Films N2 - In well-annealed thin polymer films, with non-repulsive polymer/substrate interactions, an irreversibly adsorbed layer is expected to form. These adsorbed layers have shown great potential for technological applications. However, their growth kinetics and molecular dynamics are still not fully understood. This is partially due to the hard accessibility of these layers in thin films. Here, the irreversibly adsorbed layers of homopolymer thin films are revealed by solvent-leaching experiments. First, the growth kinetics of these layers is investigated as a function of annealing times and original film thickness. The thickness, topography and quality of the adsorbed layer is controlled with Atomic Force Microscopy (AFM). Secondly, the molecular mobility of the adsorbed layer is investigated with Broadband Dielectric Spectroscopy (BDS). A recently developed nanostructured capacitor is employed to measure the adsorbed layers with a free surface layer. The results are quantitatively compared and discussed with respect to recently published work. T2 - Spring Meeting of German Physical Society CY - Berlin, Germany DA - 12.03.2018 KW - Thin polymeric films KW - Dielectric spectroscopy PY - 2018 AN - OPUS4-44489 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Szymoniak, Paulina A1 - Madkour, Sherif A1 - Schönhals, Andreas T1 - Unexpected behavior of thin PVME/PS blend films investigated by specific heat spectroscopy N2 - The structure and molecular dynamics of thin polymer films are of topical interest of soft matter-physics. Commonly, spatial structural heterogeneities of 1D confined thin films (surface, bulk-like and adsorbed layer), are expected to alter the glassy dynamics, compared to the bulk. Here, Specific Heat Spectroscopy (SHS) was used, to investigate the glassy dynamics of thin films of an asymmetric miscible PVME/PS 25/75 wt% blend. SHS measurements showed a non-monotonous thickness dependence of the dynamic Tg, on the contrary to the previously investigated PVME/PS 50/50 wt%. For PVME/PS 25/75 wt% thin films (> 30 nm), due to the presence of PVME-rich adsorbed and surface layers, the bulk-like layer experienced a thickness dependent increase of PS concentration. This led to a systematic increase of dynamic Tg. Further decrease of the film thickness (< 30 nm), resulted in a decrease of dynamic Tg, ascribed to the influence of the surface layer, which has a high molecular mobility. This is the first study, which shows deviations of dynamic Tg of thin films, compared to the bulk, resulting from the counterbalance of the free surface and adsorbed layer. T2 - Spring Meeting of German Physical Society CY - Berlin, Germany DA - 12.03.2018 KW - Thin polymeric films PY - 2018 AN - OPUS4-44494 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Munsch, Sarah Mandy A1 - Strangfeld, Christoph A1 - Kruschwitz, Sabine T1 - Determining the pore size distribution in synthetic and building materials using 1D NMR N2 - The detection of moisture in building materials has a high priority in civil engineering to locate and prevent possible moisture damages, e.g. mold, corrosion, delamination etc. Furthermore, it is of great significancy to achieve a better understanding of moisture transport and pore space in different materials. To prevent the degeneration of structures and materials, non-destructive testing methods are more and more deployed. As a non-destructive method in this work, nuclear magnetic resonance (NMR) is applied using a strayfield open magnet device that enables one-dimensional measurements in a defined volumen. By using NMR, the water content of the sample can be determined and also the pore size distribution can be deduced from the relaxation time distribution when having a comparison method like mercury intrusion porosimetry. In this study different synthetic homogenous materials with defined and almost unimodal pore size distributions are investigated as well as building materials like screed. For analyzing the pore space, the samples were measured at different saturation levels and the building materials at different hydration states as well. T2 - Magnetic Resonance in Porous Media 14 CY - Gainesville, FL, USA DA - 18.02.2018 KW - Pore size KW - Synthetic and building materials KW - NMR relaxometry KW - Mercury intrusion porosimetry PY - 2018 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-443868 N1 - Geburtsname von Munsch, Sarah Mandy: Nagel, S. M. - Birth name of Munsch, Sarah Mandy: Nagel, S. M. AN - OPUS4-44386 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Niederleithinger, Ernst A1 - Wang, Xin A1 - Herbrand, M. A1 - Müller, M. T1 - Processing ultrasonic data by coda wave interferometry to monitor load tests of concrete beams N2 - Ultrasonic transmission measurements have been used for decades to monitor concrete elements, mostly on a laboratory scale. Recently, coda wave interferometry (CWI), a technique adapted from seismology, was introduced to civil engineering experiments. It can be used to reveal subtle changes in concrete laboratory samples and even large structural elements without having a transducer directly at the place where the change is taking place. Here, several load tests until failure on large posttensioned concrete beams have been monitored using networks of embedded transducers. To detect subtle effects at the beginning of the experiments and cope with severe changes due to cracking close to failure, the coda wave interferometry procedures had to be modified to an adapted step-wise approach. Using this methodology, we were able to monitor stress distribution and localize large cracks by a relatively simple technique. Implementation of this approach on selected real structures might help to make decisions in infrastructure asset management. KW - Ultrasound KW - Concrete KW - Monitoring KW - Coda wave interferometry KW - Embedded transducers PY - 2018 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-452328 DO - https://doi.org/10.3390/s19010147 SN - 1424-8220 VL - 19 IS - 1 SP - Article 147, 1 EP - 13 PB - MDPI CY - Basel AN - OPUS4-45232 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wasmer, Paul A1 - Krome, Fabian A1 - Bulling, Jannis A1 - Prager, Jens T1 - A fluid model for the simulation of fluid-structure interaction in the scaled Boundary finite element method for prismatic Structures N2 - The Scaled Boundary Finite Element Method (SBFEM) for prismatic structures is an efficient method for the simulation of acoustic behavior. Hence a further development of the method is of great interest. The wave propagation can be calculated for isotropic and anisotropic materials in solids. As for many applications the acoustic behavior in fluids and the behavior in case of fluid-structure interaction (FSI) is subject of research, the implementation of a fluid model in SBFEM for prismatic structures is needed. In case of FSI the coupling between fluid and solid domains can be performed without additional effort when describing both domains in the same variables. Hence a displacement-based fluid description is used. As the discretized formulation leads to spurious modes, a penalty method to suppress the unphysical behavior is chosen. To validate the derived model a comparison with analytical solutions of purely fluid domains is made. As to verify that in case of FSI the model shows the right behavior, dispersion curves of water-filled pipes are calculated and compared to results obtained with Comsol. T2 - 89th GAMM Annual Meeting CY - Munich, Germany DA - 19.03.2018 KW - Scaled Boundary Finite Element Method KW - Fluid-Structure Interaction KW - Penalty Parameter PY - 2018 AN - OPUS4-45260 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Sebald, M. A1 - Gebauer, J. A1 - Koch, Matthias T1 - Under Investigation: Novel Approach towards the Synthesis of Deuterium-labelled Alternariol- and Alternariol monomethylether-Standards for the HPLC-MS/MS-Analysis in Food & Feed N2 - Alternariol (AOH) and Alternariol monomethylether (AME) are two secondary metabolites of Alternaria fungi which can be found in various foodstuffs like tomatoes, nuts and grains. Due to their toxicity and potential mutagenic activity the need for the development of high-throughput methods for the supervision of AOH- and AME-levels is of increasing interest. As the availability of both native and labelled AOH and AME analytical standards is very limited we herein wish to present a novel concise approach towards their synthesis employing a ruthenium-catalyzed ortho-arylation4 as the key step. T2 - 13th International Symposium on the Synthesis and Applications of Isotopes and Isotopically Labelled Compounds CY - Prague, Czech Republic DA - 03.06.2018 KW - Mycotoxins KW - Mass Spectrometry PY - 2018 AN - OPUS4-45268 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Maack, Stefan T1 - Bundesanstalt für Materialforschung und –prüfung (BAM) - Round table presentation N2 - Vorstellung der Tätigkeit der BAM und des FB 8.2 im Rahmen einer geplanten Greminentätigkeit im fib - Action Group 9. T2 - 2nd meeting fib Action Group 9 'Testing and SHM’ CY - München, Germany DA - 14.06.2018 KW - Zerstörungsfreie Prüfung KW - Bauwesen PY - 2018 AN - OPUS4-45215 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Terzioglu, T. A1 - Karthik, M. A1 - Hurlebaus, S. A1 - Hueste, M. A1 - Maack, Stefan A1 - Wöstmann, Jens A1 - Wiggenhauser, Herbert A1 - Krause, M. A1 - Miller, P. A1 - Olson, L. T1 - Nondestructive evaluation of grout defects in internal tendons of posttensioned girders N2 - Post-tensioning systems provide safe and efficient construction solutions for long span bridges. Despite the improved grouting practices over the past decade, existing post-tensioning systems may have significant amount of grout defects, which could lead to corrosion of the strands. Condition assessment of post-tensioning systems is necessary to allow bridge owners to take timely, proactive actions to mitigate or prevent further Deterioration and unanticipated tendon failures. A detailed experimental study conducted to assess the performance of nondestructive evaluation techniques in detecting grout defects within internal tendons is presented herein. Nondestructive evaluation techniques that include Ground Penetrating Radar, Impact Echo, Ultrasonic Tomography, and Ultrasonic Echo are evaluated in terms of detecting the location and severity of fabricated grout defects in a full-scale post-tensioned U-girder mock-up specimen. While Ground Penetrating Radar can identify the location and profile of the internal tendons, particularly metal ducts due to strong reflections, this method did not provide any information about the defect conditions within the tendon. Both Impact Echo and Ultrasonic Echo techniques are effective in identifying the Location of grout defects, but could not differentiate between water, void, or compromised grout conditions. The study clearly demonstrates the need for NDE techniques that are applicable to anchorage regions, and that are capable of estimating the severity and nature of grout defects in internal tendons. KW - Zerstörungsfreie Prüfung KW - Nondestructive testing KW - Ground penetrating radar KW - Impact Echo KW - Ultrasonic tomography KW - Ultrasonic echo KW - Bridge inspection PY - 2018 UR - https://www.sciencedirect.com/science/article/pii/S0963869517305996?via%3Dihub DO - https://doi.org/10.1016/j.ndteint.2018.05.013 SN - 0963-8695 VL - 99 SP - 23 EP - 35 PB - Elsevier Ltd. AN - OPUS4-45218 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Lauer, Franziska A1 - Diehn, Sabrina A1 - Seifert, Stephan A1 - Kneipp, Janina A1 - Sauerland, V. A1 - Barahona, C. A1 - Weidner, Steffen T1 - Multivariate analysis of MALDI imaging mass spectrometry data of mixtures of single pollen grains N2 - Here, we present an advanced approach to identify pollen grains in mixtures based on: - a simplified sample preparation procedure - MALDI imaging mass spectrometry - chemometric tools Our goals are to: - explore the biomolecular variations in pollen - determine species-specific peak patterns - discriminate and identify single pollen grains in mixtures using MSI T2 - 66th Conference on Mass Spectrometry and Allied Topics CY - San Diego, CA, USA DA - 03.06.2018 KW - Pollen PY - 2018 AN - OPUS4-45196 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Müller, Anja A1 - Lippitz, Andreas A1 - Swaraj, Sufal A1 - Sparnacci, Katia A1 - Unger, Wolfgang T1 - Progress Talk 3 / Investigating the dimensions of core|shell nanoparticles using scanning transmission X-ray microscopy (STXM) N2 - This presentation deals with the progress between month twelve and nineteen of my PhD thesis. I prepared it, in order to update my supervisor Prof. Kemnitz and my colleagues from the department of chemistry at the Humboldt-Universität zu Berlin (HU). T2 - Working Group Meeting of Prof. Erhard Kemnitz CY - Humboldt-Universität zu Berlin (HU), Germany DA - 30.01.2018 KW - Core-shell nanoparticles KW - Metrology KW - PS KW - PTFE KW - Polymers KW - SEM KW - STXM PY - 2018 N1 - Geburtsname von Müller, Anja: Hermanns, A. - Birth name of Müller, Anja: Hermanns, A. AN - OPUS4-43981 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -