TY - CONF A1 - Resch-Genger, Ute T1 - Standardization of fluorescence measurements: Design, development, validation, and fabrication of format-adaptable fluorescence standards for intensity, spectral, and temporal quantities N2 - Photoluminescence techniques are amongst the most widely used tools in the material and life sciences, with new and exciting applications continuously emerging, due to their many advantages like comparative ease of use, unique sensitivity, non-invasive character, and potential for multiplexing, remote sensing, and miniaturization. Drawbacks are , however, signals, that contain unwanted wavelength- and polarization contributions from instrument-dependent effects, which are time-dependent due to the aging of instrument components, and difficulties to measure absolute fluorescence intensities. Thus, there is a considerable need for standards for intensity, spectral, and temporal fluorescence quantities to meet the increasing need for instrument performance validation and global trends to harmonize physicochemical measurements. In this respect, instrument calibration strategies together with different types of fluorescence standards are presented as well as design concepts for robust, easy-to-use, and format-adaptable fluorescence standards useable for the determination of different fluorescence parameters and a broad variety of fluorescence techniques. T2 - SALSA-Kolloquien CY - Berlin, Germany DA - 07.06.2016 KW - Fluorescence KW - Standard KW - Quality assurance KW - Spectral correction KW - Quantum yield PY - 2016 AN - OPUS4-37070 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kruschwitz, Sabine T1 - Measuring moisture in building material - an overview N2 - In Germany there is an existing built infrastructure worth about 50 trillion Euros. The expected lifetimes of individual structures are up to 100 years. Considerable costs (annually about 35 billion Euros, the trend continues upwards) are involved in order to maintain and rehabilitate both residential as well as transportation infrastructure buildings. Most damages we observe on our built infrastructure are moisture-induced processes. Consequently reliable moisture measurement tools a highly needed for meaningful building diagnosis investigations. The optimal moisture measuring technique would be non-destructive, fast, repeatable, reliable, independent of steel in the vicinity, the surface condition or possible salt loads of the material under test. Since this is unfortunately not the case for any non-destructive method, it is often very difficult to decide for users which method to use for the particular testing problem. The only standardized methods in Germany are the “direct” and destructive Darr- and the CM tests. Although they can be highly accurate (when handled with care during the sampling), they deliver only punctual information and cannot be used for monitoring. The other, non-destructive methods are based on the change in humidity-dependent physical material properties. The underlying physics, their particular advantages and disadvantages are discussed in this paper. T2 - Building Safety Symposium CY - Hong Kong, China DA - 22.04.2016 KW - Non-destructive methods KW - Moisture measuring KW - Electrical methods KW - Microwave PY - 2016 AN - OPUS4-37118 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kricheldorf, H. R. A1 - Weidner, Steffen T1 - Dispersities of Polyesters of Various Diphenols Prepared by Irreversible Polycondensations N2 - Polyesters of bisphenol-A, bisphenol-P, catechol, and sebacic acid are prepared and different synthetic methods are compared. The diphenols are condensed with sebacoyl chloride either in dichloromethane/pyridine or in refl uxing chlorobenzene without HCl-acceptor. Further- more, bisphenol-A acetate is polycondensed with sebacic acid in bulk. All experiments are worked up so that fractionation is avoided. The extent of cyclization is estimated by matrix-assisted laser desorption/ionization mass spectrometry (MALDI MS) and the molar mass distribution by size exclusion chromatography (SEC). Polycondensations in solution yield larger fractions of cyclics and higher dispersities (up to 11). Polycondensations in bulk give lower fractions of cycles and dispersities from 4.6 to 6.3 for high molar mass polyesters or 2.8 to 3.5 for low molar mass products. Characteristic curves describing the dependence of the dispersity on the initial monomer concentration are elaborated. KW - cyclization KW - dispersity KW - mass spectra KW - polycondensation KW - polyesters PY - 2016 DO - https://doi.org/10.1002/macp.201600004 IS - 217 SP - 1361 EP - 1369 PB - Wiley-VCH Verlag CY - Weinheim AN - OPUS4-37120 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Schneider, Ralf A1 - Weigert, Florian A1 - Lesnyak, V. A1 - Leubner, S. A1 - Lorenz, T. A1 - Behnke, Thomas A1 - Dubavik, A. A1 - Joswig, J.-O. A1 - Resch-Genger, Ute A1 - Gaponik, N. A1 - Eychmüller, A. ED - Resch-Genger, Ute ED - Schneider, Ralf T1 - pH and concentration dependence of the optical properties of thiol-capped CdTe nanocrystals in water and D2O N2 - The optical properties of semiconductor nanocrystals (SC NCs) are largely controlled by their size and surface chemistry, i.e., the chemical composition and thickness of inorganic passivation shells and the chemical nature and number of surface ligands as well as the strength of their bonds to surface atoms. The latter is particularly important for CdTe NCs, which – together with alloyed CdₓHg₁₋ₓTe – are the only SC NCs that can be prepared in water in high quality without the need for an additional inorganic passivation shell. Aiming at a better understanding of the role of stabilizing ligands for the control of the application-relevant fluorescence features of SC NCs, we assessed the influence of two of the most commonly used monodentate thiol ligands, thioglycolic acid (TGA) and mercaptopropionic acid (MPA), on the colloidal stability, photoluminescence (PL) quantum yield (QY), and PL decay behavior of a set of CdTe NC colloids. As an indirect measure for the strength of the coordinative bond of the ligands to SC NC surface atoms, the influence of the pH (pD) and the concentration on the PL properties of these colloids was examined in water and D₂O and compared to the results from previous dilution studies with a set of thiol-capped Cd₁₋ₓHgₓTe SC NCs in D₂O. As a prerequisite for these studies, the number of surface ligands was determined photometrically at different steps of purification after SC NC synthesis with Ellman’s test. Our results demonstrate ligand control of the pH-dependent PL of these SC NCs, with MPA-stabilized CdTe NCs being less prone to luminescence quenching than TGA-capped ones. For both types of CdTe colloids, ligand desorption is more pronounced in H₂O compared to D₂O, underlining also the role of hydrogen bonding and solvent molecules. KW - Quantum dots KW - Fluorescence KW - Ligand analysis KW - Nano particles PY - 2016 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-371253 DO - https://doi.org/10.1039/c6cp03123d VL - 18 IS - 28 SP - 19083 EP - 19092 PB - RSC CY - Cambridge AN - OPUS4-37125 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Nadejde, C. A1 - Neamtu, M. A1 - Hodoroaba, Vasile-Dan A1 - Schneider, Rudolf A1 - Ababei, G. A1 - Panne, Ulrich T1 - Hybrid iron-based core-shell magnetic catalysts for fast degradation of bisphenol A in aqueous systems N2 - Three types of hybrid modified magnetite (Fe₃O₄) nanoparticles, functionalized with either chitosan, chitosan/iron (II) oxalate or chitosan/iron (III) citrate, were synthesized by chemical precipitation method. The obtained nanomaterials were characterized by energy dispersive X-ray spectroscopy, X-ray diffraction, Brunauer–Emmett–Teller analysis, scanning and Transmission electron microscopy, Fourier transform infrared spectroscopy and vibrating sample magnetometry. The prepared composites were further tested as magnetic catalysts for the removal of bisphenol A (BPA) in aqueous media. The kinetic Degradation experiments were performed at laboratory scale, while the best operational parameters for all three materials were established: 1.00 g L⁻¹ of catalyst, 10 mmol L⁻¹ H₂O₂, under simulated solar light irradiation. After 15 min of UVA irradiation under the experimental conditions mentioned above, it was possible to decompose up to 99% of the micropollutant over all catalysts. Fe₃O₄/chitosan/iron oxalate catalyst showed the highest and fastest catalytic activity in BPA removal. Catalytic wet peroxide oxidation of non-biodegradable micropollutants on such iron-based hybrid nanoparticles can be a suitable pre-treatment method for wastewater decontamination, as an environment-friendly simplified Approach for water clean-up. KW - Katalysator KW - Bisphenol A KW - Nano KW - Fenton KW - Magnetische Nanopartikel PY - 2016 DO - https://doi.org/10.1016/j.cej.2016.05.090 SN - 1385-8947 VL - 302 SP - 587 EP - 594 PB - Elsevier CY - Amsterdam AN - OPUS4-37126 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bartholmai, Matthias A1 - Johann, Sergej A1 - Kammermeier, Michael A1 - Müller, Maximilian A1 - Strangfeld, Christoph T1 - RFID sensor systems embedded in concrete – systematical investigation of the transmission characteristics N2 - Long-term completely embedded sensor systems offer innovative possibilities for structural health monitoring of concrete structures. Measuring of relevant parameters, e.g., temperature, humidity, or indication of corrosion can be performed with low energy sensors. This allows to implement passive RFID sensor systems without cable connection and battery, which are power supplied exclusively by the electromagnetic field from the external reader device. To evaluate characteristics and conditions of this concept, a systematical investigation of the transmission characteristics with variation of relevant parameters, as communication frequency, installation depth, type of concrete, moisture content, etc. is currently carried out in an interdisciplinary research project at BAM. First results are presented in this paper. T2 - 8th European Workshop On Structural Health Monitoring CY - Bilbao, Spain DA - 05.07.2016 KW - Structural health monitoring KW - Embedded sensor KW - Energy harvesting KW - Wireless sensors KW - RFID sensors KW - Transmission characteristics PY - 2016 SP - 1 EP - 5 AN - OPUS4-37129 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bartholmai, Matthias A1 - Strangfeld, Christoph T1 - RFID sensor systems embedded in concrete – systematical investigation of the transmission characteristics N2 - Long-term completely embedded sensor systems offer innovative possibilities for structural health Monitoring of concrete structures. Measuring of relevant parameters, e.g., temperature, humidity, or indication of corrosion can be performed with low energy sensors. This allows to implement passive RFID sensor systems without cable connection and battery, which are power supplied exclusively by the electromagnetic field from the external Reader device. To evaluate characteristics and conditions of this concept, a systematical Investigation of the transmission characteristics with variation of relevant parameters, as communication frequency, installation depth, type of concrete, moisture content, etc. is currently carried out in an interdisciplinary research project at BAM. First results are presented in this paper. T2 - 8th European Workshop On Structural Health Monitoring CY - Bilbao, Spain DA - 05.07.2016 KW - Embedded sensor KW - Energy harvesting KW - Wireless sensors KW - RFID sensors KW - Transmission characteristics KW - Structural health monitoring PY - 2016 AN - OPUS4-37130 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Köppe, Enrico A1 - Bartholmai, Matthias A1 - Daum, Werner A1 - Gong, Xing A1 - Hofmann, Detlef A1 - Basedau, Frank A1 - Schukar, Vivien A1 - Westphal, Anja A1 - Sahre, Mario A1 - Beck, Uwe T1 - New self - diagnostic fiber optical sensor technique for structural health monitoring N2 - Fiber optic sensors have gained increasing importance in recent years and are well established in many areas of industrial applications. In this paper, we introduce a concept of a self-diagnostic fiber optic sensor. The presented sensor is to resolve the problems of embedded fiber optic sensors in complex structures and to enable the validation under operational conditions. For this purpose, different magnetostrictive coated fiber optic sensors were developed and various experiments were performed to verify their mode of Operation and to determine the respective reproducibility. The measuring principle is illustrated by obtained experimental results, which showed a change in wavelength from 1 pm at a magnetic field strength change of 0.25 mT. In addition, the temperature characteristics of the implemented magnetostrictive sensor were analyzed and an experimental factor of 1.5 compared to a reference fiber optic sensor was determined. T2 - 32nd DANUBIA ADRIA SYMPOSIUM on Advances in Experimental Mechanics CY - Starý Smokovec, Slovakia DA - 22.09.2015 KW - Self-diagnostic fiber optical sensor KW - Magnetostrictive metal coating KW - Magnetic field KW - Fiber bragg grating PY - 2016 DO - https://doi.org/10.1016/j.matpr.2016.03.038 SN - 2214-7853 VL - 3 IS - 4 SP - 1009 EP - 1013 AN - OPUS4-37131 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Resch-Genger, Ute T1 - Simple methods, validation concepts, and reference materials for the characterization of functional nanomaterials and microparticles N2 - The surface chemistry / functionalization of nanomaterials and microparticles largely controls the stability of these materials as well as their solubility and subsequent biofunctionalization and their interactions with biological systems. Moreover, in the case of some nanomaterials like semiconductor quantum dots or lanthanide-based upconversion nanocrystals, the ligand shell strongly affects their optical properties, e.g., via passivation of surface states and traps that favor luminescence quenching or the protection of surface atoms from quenching water molecules. This renders analytical methods for the quantification of surface groups like functionalities very important. Targets of broad interest are here amino, carboxyl, alkine and maleimide groups used for common bioconjugation reactions and typical ligands like thiols and polyethylene glycol (PEG) molecules of varying length, used for the tuning of material hydrophilicity and biocompatibility, minimization of unspecific interactions, prevention of biofouling, and enhancement of blood circulation times as well as surface-bound biomolecules like streptavidin or other biomolecules relevant e.g., for diagnostic assays. Here, we focus on simple optical methods relying on standard laboratory instrumentation, validated by method comparison and/or mass balances and present examples for their use for the characterization of different types of nanomaterials and microparticles. T2 - Innovationsforum Senftenberg CY - Senftenberg, Germany DA - 01.06.2016 KW - Surface chemistry KW - Functional group analysis KW - Thiol assay KW - Fluorescence KW - Nanomaterial KW - Nanoparticle KW - PEG KW - Ligand KW - Semiconductor quantum dot KW - Quantum yield KW - Quantification KW - Method validation KW - Integrating sphere spectroscopy KW - Fluorescence standard PY - 2016 N1 - Geburtsname von Nirmalananthan-Budau, Nithiya: Nirmalananthan, N. - Birth name of Nirmalananthan-Budau, Nithiya: Nirmalananthan, N. AN - OPUS4-37111 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Resch-Genger, Ute T1 - Applications and challenges of luminescence-based detection methods in the life and material sciences N2 - Luminescence-based detection methods, ranging from fluorescence spectroscopy for photophysical and mechanistic studies over sensing applications, chromatographic separation techniques and the microarray technology with fluorescence detection to fluorescence microscopy, flow cytometry, single molecule spectroscopy, and molecular imaging to integrating sphere spectroscopy, are among the most widely used methods in the life and material sciences. This is due to e.g., their unique sensitivity enabling the detection of single molecules, potential for multiplexing, ease of combination with spatial resolution, and suitability for remote sensing. Many of these advantages are closely linked to the choice of suitable molecular and nanoscale fluorescent reporters, typically required for signal generation. This includes organic dyes without and with sensor function, fluorophore-encoded polymeric and silica nanoparticles as well as nanocrystalline systems like semiconductor quantum dots and upconversion phosphors, emitting in the visible (vis), near-infrared (NIR), and IR (infrared). Current challenges present the environment sensitivity of most fluorophores, rendering fluorescence spectra, measured intensities/fluorescence quantum yields, and fluorescence decay kinetics matrix-dependent, and instrument-specific distortions of measured fluorescence signals that need to be considered for quantification and comparability of data, particularly fluorescence spectra. Here, current applications of luminescence-based methods and different types of reporters will be presented. In this context, suitable spectroscopic tools for the characteri-zation of the optical properties of fluorescent reporters and fluorophore-encoded microparticles, analytical tools for the determination of the surface chemistry of different types of particles, and different multiplexing strategies will be discussed. T2 - 9th Meeting of Engineering of Functional Interfaces CY - Wildau,Germany DA - 03.07.2016 KW - Fluorescence KW - Multiplexing KW - Lifetime KW - Nanomaterial KW - Nanoparticle KW - PEG KW - Ligand KW - Semiconductor quantum dot KW - Quantum yield KW - Quantification KW - Upconversion nanoparticle KW - Integrating sphere spectroscopy KW - NIR KW - IR KW - Fluorescence standard KW - Calibration PY - 2016 AN - OPUS4-37112 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Weller, Andreas T1 - Induced polarization and pore radius - a discussion N2 - Permeability estimation from spectral induced polarization (SIP) measurements is based on a fundamental premise that the characteristic relaxation time (t) is related to the effective hydraulic radius (reff) controlling fluid flow. The approach requires a reliable estimate of the diffusion coefficient of the ions in the electrical double layer. Others have assumed a value for the diffusion coefficient, or postulated different values for clay versus clay-free rocks. We examine the link between t and reff for an extensive database of sandstone sampleswhere mercury porosimetry data confirm that reff is reliably determined from a modification of the Hagen-Poiseuille equation assuming that the electrical tortuosity is equal to the hydraulic tortuosity. Our database does not support the existence of 1 or 2 distinct representative diffusion coefficients but instead demonstrates strong evidence for 6 orders of magnitude of variation in an apparent diffusion coefficient that is well correlated with both reff and the specific surface area per unit pore volume (Spor). Two scenarios can explain our findings: (1) the length-scale defined by t is not equal to reff and is likely much longer due to the control of pore surface roughness; (2) the range of diffusion coefficients is large and likely determined by the relative proportions of the different minerals (e.g. silica, clays) making up the rock. In either case, the estimation of reff (and hence permeability) is inherently uncertain from SIP relaxation time. T2 - IP Workshop 2016 CY - Aarhus, Denmark DA - 06.06.2016 KW - pore radius KW - mercury intrusion capillary pressure KW - spectral induced polarization KW - relaxation time PY - 2016 AN - OPUS4-37116 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Götschel, S. A1 - Höhne, Christian A1 - Kolkoori, Sanjeevareddy A1 - Mitzscherling, Steffen A1 - Prager, Jens A1 - Weiser, M. T1 - Ray tracing boundary value problems: simulation and SAFT reconstruction for ultrasonic testing N2 - The application of advanced imaging techniques for the ultrasonic inspection of inhomogeneous anisotropic materials like austenitic and dissimilar welds requires information about acoustic wave Propagation through the material, in particular travel times between two Points in the material. Forward ray tracing is a popular approach to determine traveling paths and arrival times but is ill suited for inverse problems since a large number of rays have to be computed in order to arrive at prescribed end points. In this contribution we discuss boundary value problems for acoustic rays, where the ray path between two given points is determined by solving the Eikonal equation. The implementation of such a two Point boundary value ray tracer for sound field simulations through an austenitic weld is described and its efficiency as well as the obtained results are compared to those of a forward ray tracer. The results are validated by comparison with experimental results and commercially available UT simulation tools. As an application, we discuss an implementation of the method for SAFT (Synthetic Aperture Focusing Technique) reconstruction. The ray tracer calculates the required travel time through the anisotropic columnar grain structure of the austenitic weld. There, the formulation of ray tracing as a boundary value Problem allows a straightforward derivation of the ray path from a given transducer Position to any pixel in the reconstruction area and reduces the computational cost considerably. T2 - 19th World Conference on Non-Destructive Testing 2016 CY - München, Germany DA - 13.06.2016 KW - Ultrasonic testing KW - SAFT KW - Ray tracing KW - Simulation PY - 2016 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-370494 UR - www.ndt.net/?id=19437 SP - ID 19437, 1 EP - 8 AN - OPUS4-37049 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Boehm, Rainer T1 - What is the benefit of the total focussing method and full matrix capture for ultrasonic imaging using the phased array technique N2 - In the last two decades automated ultrasonic inspection devices took over a lot of applications that prior have been carried out using manual inspection with the evaluation of A-scans only. In parallel phased array systems have been developed and brought to the market which offer detailed and fast control over the sound field. When applying automated inspection phased array systems for UT measurements imaging of the recorded data in combination with the probe positioning data is used for the evaluation of inspections. B-Scan, C-Scan and S-Scan images are typically used with this setup. For more sophisticated applications with linear arrays echo tomography and syntethic aperture focusing technique (SAFT) are well known methods and often applied for high resolution image reconstruction. Since channel count of phased array systems is constantly rising, matrix arrays with up to 256 elements entered the market. Signal processing in the matrix domain became 3D. Since some years the Total Focusing Method (TFM) is an additional imaging tool for these type of application. It is based on the Full Matrix Capture (FMC) using the elements of phased array probes as separate transmitters and receivers. In this contribution we discuss the common ground of SAFT and TFM as well as the differences between these imaging tools. The combined use of automated inspection, matrix arrays and signal processing for high resolution measurements is a challenging task where a very long parameter list has to be taken into account. Under which conditions which elements of the full matrix should be taken for the reconstruction for best results? Based on examples taken from measured and simulated echo signals it will be shown how image resolution can be optimized in dependence of different parameters like the distance between transmitters and receivers and their directivity patterns, the depth of echo source and the specimen geometry. T2 - 19th World Conference on Non-Destructive Testing CY - Munich, Germany DA - 13.06.2016 KW - Ultrasonic testing KW - Ultrasonic imaging KW - Phased array KW - Total focussing method KW - Full matrix capture PY - 2016 UR - https://www.wcndt2016.com/programme AN - OPUS4-37051 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Götschel, S. T1 - Ray tracing boudary value problems: simulation and SAFT reconstruction for ultrasonic testing N2 - The application of advanced imaging techniques for the ultrasonic inspection of inhomogeneous anisotropic materials like austenitic and dissimilar welds requires information about acoustic wave propagation through the material, in particular travel times between two points in the material. Forward ray tracing is a popular approach to determine traveling paths and arrival times but is ill suited for inverse problems since a large number of rays have to be computed in order to arrive at prescribed end points. In this contribution we discuss boundary value problems for acoustic rays, where the ray path between two given points is determined by solving the eikonal equation. The implementation of such a two point boundary value ray tracer for sound field simulations through an austenitic weld is described and its efficiency as well as the obtained results are compared to those of a forward ray tracer. The results are validated by comparison with experimental results and commercially available UT simulation tools. As an application, we discuss an implementation of the method for SAFT (Synthetic Aperture Focusing Technique) reconstruction. The ray tracer calculates the required travel time through the anisotropic columnar grain structure of the austenitic weld. There, the formulation of ray tracing as a boundary value problem allows a straightforward derivation of the ray path from a given transducer position to any pixel in the reconstruction area and reduces the computational cost considerably. T2 - 19th World Conference on Non-Destructive Testing 2016 CY - Munich, Germany DA - 13.06.2016 KW - Ultrasonic testing KW - SAFT KW - Ray tracing KW - Simulation PY - 2016 UR - www.ndt.net/?id=19437 UR - https://www.wcndt2016.com/portals/wcndt/bb/Fr1H4.pdf AN - OPUS4-37052 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Habel, Wolfgang R. A1 - Krebber, Katerina A1 - Daum, Werner T1 - Results in standardization of FOS to support the use of SHM systems N2 - Measurement and data recording systems are important parts of a holistic Structural Health Monitoring (SHM) system. New sensor technologies such as fiber-optic sensors are often used; however, standards (or at least guidelines) are not yet available or internationally approved. This lack in standardization makes the acceptance of FOS technologies in complex SHM systems substantially difficult. A standard family for different FOS technologies is therefore being developed that should help to design SHM systems in an optimal way. International standardization activities take place in several standardization bodies such as IEC and ASTM, and within SHM societies such as ISHMII. The paper reports on activities in standardization of fiber-optic sensors, on results already achieved, and on newly started projects. Combined activities of fiber sensor experts and SHM experts from Civil Engineering are presented. These contributions should help owners of structures as well as developers of sensors and monitoring systems to select effective and validated sensing technologies. Using these standards, both parties find recommendations how to proceed in development of SHM systems to evaluate the structural behavior based on e.g. standardized fiber optic sensors, and to derive necessary measures, e.g. the optimal maintenance strategy. T2 - Sixth European Workshop on Optical Fibre Sensors CY - Limerick, Ireland DA - 30.05.2016 KW - Fiber-optic sensor KW - Standard KW - Temperature KW - Strain KW - Monitoring KW - Structural health KW - Application PY - 2016 DO - https://doi.org/10.1117/12.2236863 SN - 0277-786X VL - 9916 SP - 991625-1 EP - 991625-4 AN - OPUS4-37053 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Maul, R. T1 - Phomopsins in legumes - a multidimensional approach N2 - Fungal secondary metabolites such as phomopsin A (PHO-A) produced by the fungus Diaporthe toxica are referred to as “emerging” mycotoxins. Recently, we developed a biosynthetic approach to gain access to 15N-isotopically labelled PHO-A as internal standard (IS) for PHO-A matrix independent quantification of PHO-A in various commodities. Aim of the present work was to elucidate the applicability of the new IS for accurate quantification and to investigate the phomopsin formation on various legume seeds as well as plant material. In summary, the applicability of the SIDA-HPLC-MS/MS method could be proven and the potential of D. toxica to produce high amounts of phomopsins under unfavorable conditions on lupins and other legume seeds could be shown. Moreover, a novel toxic methylated PHO-A derivative was unveiled in natural samples infested with D. toxica. T2 - 38. Mycotoxin-Workshop CY - Berlin, Germany DA - 02.05.2016 KW - Phomopsin-Derivate KW - Leguminosen KW - Stabilisotopenverdünnungsanalyse KW - HPLC-MS/MS KW - HRMS-Identifizierung KW - Toxizität PY - 2016 AN - OPUS4-37056 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kruschwitz, Sabine T1 - Moisture measurement methods N2 - Moisture can cause imperfect sealings, faulty roof constructions, cracks and other kind of damages. For measuring the moisture in construction materials like concrete and screed, there are destructive(direct) and non-destructive(indirect) methods, that can be used. This presentation gives an overview and a comparison of these methods. T2 - Nondestructive Testing and Evaluation in Civil Engineering and Surveying - Advanced Training 2016 CY - Berlin, Germany DA - 14.07.2016 KW - Moisture KW - Non-destructive testing PY - 2016 AN - OPUS4-37005 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Heckel, Thomas T1 - Increasing the sensitivity of ultrasonic phased array wheel set axle inspection by using signal processing N2 - Der einwandfreie Zustand der Radsätze von Schienenfahrzeugen ist von größter Bedeutung für den sicheren Betrieb. Die Radsatzwellen werden durch eine große Zahl von Lastwechseln individuell unterschiedlich beansprucht. Dabei spielen viele Einflüsse wie äußere statische und dynamische Lasten, innere Lasten aufgrund von Unwuchten und inneren Spannungen und Umweltbedingungen entscheidende Rollen. Eine regelmäßige Prüfung ist daher obligatorisch. BTD entwickelt im Rahmen eines MNPQ-Projektes in Kooperation mit der BAM eine Phased Array Technik zur automatisierten Prüfung von Radsatzwellen im eingebauten Zustand. Die schwierigen Ankoppelbedingungen aufgrund der begrenzten Zugänglichkeit, der komplexen Geometrie sowie Farbschichten und Schmutz auf der Radsatzwelle stellen hierbei große Herausforderungen dar. Zu deren Bewältigung werden neben optimierten Prüfköpfen, einer in die Wasservorlaufstrecke integrierten akustischen Linse und einer speziellen Ankoppeltechnik auch Signalverarbeitungsalgorithmen eingesetzt. Die Darstellung der Signalverarbeitung ist der Schwerpunkt dieses Beitrages. Mit Hilfe von Messdatensätzen präparierter Testwellen werden verschiedene Algorithmen erprobt und hinsichtlich der Stabilität, dem Verhalten bezüglich der Ankoppelschwankungen und veränderter Wellengeometrien und der Fähigkeit zur automatischen Unterscheidung von Fehler- und Formanzeigen bewertet. Letztlich wird die beste Lösung im entwickelten Prüfsystem eingesetzt. T2 - 19th WCNDT - World Conference on Non Destructive Testing CY - München, Germany DA - 13.06.2016 KW - Ultrasound KW - Phased array KW - Wheelset KW - Railway KW - Signal processing PY - 2016 AN - OPUS4-37008 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Jaenisch, Gerd-Rüdiger T1 - Simulation and experimental results of manual UT-testing of hollow wheel set axles during the education of operators N2 - The reliability of wheel set axle testing is of high importance because small discontinuities caused during manufacturing or rock fall impacts during operation might cause growing cracks during the operation load cycles. While most of the axles are tested by automated UT-systems today, the basic education of railway NDT operators is still manual testing providing the basic understanding and skills for the operators. In Germany it is a common rule that NDT operators in the railway branch need to refresh their knowledge and skills every five years including a refresh examination. The testing results from these exercises and from a parallel round robin test have been sampled at the DGZfP Railway Education Centre in Wittenberge for a period of about 5 years. The results of the operators written in test record sheets were compared with the “true” test crack or notch position in the axles used for examination. In this way the testing results could be categorized into “hits” and “misses” and the “hits” were further evaluated due to correct position and adequate amplitude height. Considering some thousand indications documented by the operators during the refresh examination and comparing transition bow, shaft and seat it was a highlight to see that the operators reach their best detection rate in the transition bow of the wheel axle set while this is often the most difficult part concerning the UT-echoes. Fortunately this is due to their raised awareness in the transition bow region because this is the most dangerous region with respect to fracture mechanics. For two selected axles the experimental set up of 45° and 70° inward and outward UT-testing were also simulated showing clearly the difficulties of the UT-echoes detection of some specific test defects. T2 - XXII Saint-Petersburg Conference on Ultrasonic Testing of Metals and Advanced Materials (UTM 2016) CY - St. Petersburg, Russia DA - 24.05.2016 KW - Ultrasound KW - Manual testing KW - NDT reliability KW - Fault tree analysis KW - Education of NDT personnel PY - 2016 AN - OPUS4-37013 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Nietzold, Carolin A1 - Dietrich, Paul A1 - Lippitz, Andreas A1 - Panne, Ulrich A1 - Unger, Wolfgang T1 - Cyclodextrin – ferrocene host – guest complexes on silicon oxide surfaces N2 - Research on carbohydrate based interactions with proteins, nucleic acids or antibodies has gained increased interest in the last years especially in clinical diagnosis or drug development. The efficiency of diagnostic interfaces depends upon the number of probe molecules, e.g. carbohydrates. The control of surface parameters as density and distribution of immobilized carbohydrates is essential for a reliable interaction with protein analytes. A controlled production of biomolecular interfaces can be reached by a stepwise quality control during buildup of these biointerfaces. Here, ß-amino-cyclodextrin molecules were attached to amine-reactive silicon oxide surfaces via click chemistry to construct a model biosensor surface. The amount of surface bound carbohydrates was determined indirectly after chemical derivatization with 4-(trifluoromethyl)-benzylamine (TFMBA). Moreover, these surfaces were used to form host-guest complexes of ferrocene (guest) and β-cyclodextrin (host) moieties to mimic the target binding (sensing) of the model biosensor. Surface chemical analysis of all steps during biosensor construction was performed using X-ray photoelectron spectroscopy (XPS) and near-edge X-ray absorption fine structure spectroscopy (NEXAFS). Our approach widens the possibilities to generate switchable surfaces based on ß-Cyclodextrin surfaces for biosensor applications. KW - ß-amino-cyclodextrin KW - Ferrocene KW - Guest complexe KW - XPS KW - NEXAFS PY - 2016 DO - https://doi.org/10.1002/sia.5958 SN - 0142-2421 SN - 1096-9918 VL - 48 IS - 7 SP - 606 EP - 610 PB - Wiley AN - OPUS4-36856 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schmidt, Wolfram A1 - Mota Gassó, Berta A1 - Sturm, Heinz A1 - Pauli, Jutta ED - Greim, M. ED - Kusterle, W. ED - Teubert, O. T1 - Influence of effects on nano and micro scale on the rheological performance of cement paste, mortar and concrete N2 - Chemical admixtures like superplasticisers or stabilising agents are of ever increasing importance for modern concrete technology. They liberate the workability of concrete from its dependency on water content, and thus, open the gate towards innovative and future oriented concrete technologies such as self-compacting concrete. Today, admixture addition has become common practice in concrete technology, but the understanding of their highly complex mode of operation is extremely difficult and demands for understanding of processes within the range between nanometres and centimetres. Due to its complex time-dependent, multi-phase and multi-scale behaviour, flowable concrete systems are highly complicated and cannot be described comprehensively by simple models. It is therefore extremely challenging to identify the relevant parameters that predominantly control flow phenomena on different size scales, since these may occur on any scale between the nano scale (e.g. superplasticizer adsorption) and macro scale (e.g. grading of the aggregates). The present study discusses fundamental mechanisms at the interface between particle or hydrate surfaces and the fluid phase at a very early stage of concrete formation, and links these effects to macroscopic flow phenomena. Methods are discussed that appear promising interdisciplinary tools for enhancement of the understanding of the relevant interactions that are responsible for the macroscopic flow of flowable concrete. T2 - 25. Workshop und Kolloquium Rheologische Messsungen an Baustoffen CY - Regensburg, Germany DA - 02.03.2016 KW - Rheology KW - Cement KW - Concrete KW - Superplasticizer KW - Nano scale PY - 2016 SN - 978-3-7345-1313-8 SP - 294 EP - 307 PB - tredition CY - Hamburg AN - OPUS4-36862 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hodoroaba, Vasile-Dan T1 - Nanoparticles and films characterization: Electron microscopy and related techniques N2 - Scanning Electron Microscopy (SEM) represents the mostly widespread method available in analytical laboratories dedicated to the characterization of physical properties such as morphology of various solid materials from ‘micro-’ down to the nanometre scale. The use of secondary electrons excited by a sharply, nm-focussed primary electron beam enables at any modern SEM to image objects with high in-depth and lateral sensitivity, i.e. with high spatial resolution. Hence, e. g. nanoparticles (NPs) are able to be easily characterized with respect to their individual size and shape, but also to the morphology of their surface. By preparing the nano-objects on thin membranes as electron transparent samples it is possible to perform electron microscopy in the transmission mode (TEM and TSEM). The corresponding transmission (i.e. mass-thickness) contrast reveals in-depth information, but is also well suited for dimensional measurements in the 2D projection image. Both the surface sensitive mode and the transmission one are meanwhile available at any modern SEM. If an X-ray spectrometer is attached to an electron microscope, it is possible to analyse the characteristic X-rays induced by electron bombardment. Most electron microscopes have attached an energy dispersive X-ray spectrometer (EDX) so that EDX elemental maps can be carried out. Recent technological developments of high throughput EDS detectors and their advantages regarding high-resolution X-ray analysis down to the nm range are reviewed. High-resolution micrographs (SEM, TSEM, TEM) and corresponding X-ray elemental maps on various representative nanoparticles, but also layered samples prepared in cross-section, will be presented and discussed. The importance of selecting the best suited analysis conditions will be highlighted. Also other, often challenging, topics such as sample preparation and image data processing will be critically addressed by practical examples. Further analytical techniques able to be employed at an electron microscope, like cathodoluminescence (CL) or micro-X-ray fluorescence (µXRF) will be briefly surveyed. T2 - Nanoscience Meets Metrology - Synthesis, Characterization, Testing and Applications of Validated Nanoparticles - International Summer School CY - Turin, Italy DA - 04.09.2016 KW - Nanoparticles KW - Electron microscopy KW - High-resolution KW - Thin films KW - X-ray spectroscopy PY - 2016 UR - http://www.setnanometro.eu/events/ AN - OPUS4-37325 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Lichtenstein, D. T1 - Core or coating material – What dictates the uptake and translocation of nanoparticles in vitro? N2 - Nanoparticle size and shape are crucial parameters regarding the potential of nanoparticles to penetrate cell membranes and epithelial barriers. Current research in this field additionally focuses on the particle coating material. In order to distinguish between core- and coating-related effects in nanoparticle uptake and translocation behavior, this study investigated two nanoparticles equal in size, coating and charge but different in core material. Silver and iron oxide coated with poly (acrylic acid) (PAS) were extensively characterized by TEM (transmission electron microscopy), SAXS (Small-Angle X-ray Scattering), ZetasizerTM and NanoSightTM. For uptake and transport studies the widely used human intestinal Caco-2 model in a TranswellTM-system with subsequent elemental analysis (AAS) was used. For evaluation and particle visualization transmission electron microscopy (TEM) and Ion Beam Microscopy (IBM) were conducted. Although similar in size, charge and coating material, the behavior of particles in Caco-2 cells was quite different. The internalized amount was comparable, but PAA-coated iron oxide nanoparticles were additionally transported through the cells. By contrast, PAA-coated silver nanoparticles remained in the cells. Our findings suggest that the coating material influenced only the uptake of the nanoparticles whereas the translocation was determined by the core material. In summary, a core-dependent effect on nanoparticle translocation was revealed. Both the uptake and transport of nanoparticles in and through cells should be considered when discussing nanoparticle fate and safety. T2 - Eurotox 2016 CY - Seville, Spain DA - 04.09.2016 KW - Cellular uptake KW - SAXS PY - 2016 AN - OPUS4-37338 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kästner, Claudia T1 - Coating-tuned catalytic activity of silver nanoparticles N2 - The use of silver nanoparticles in consumer related products has significantly increased over the last decade, especially due to their antimicrobial properties. Today they are used in a variety of products, which range from textiles over children toys and dietary supplements. Therefore, research on silver in a nanoscale form becomes increasingly important for a high amount of studies. Unfortunately the results of these studies are extremely diverse and do not lead to a consistent evaluation of the toxicity of silver nanoparticles. The central problem lies in the utilization of a wide range of silver nanoparticles, which show a broad size distribution. To overcome this problem we synthesized ultra-small core-shell silver nanoparticles by an up-scaled modification of the polyol process. The particles are highly stable and show no aggregation for more than six months. Small-angle X-ray scattering (SAXS) analysis reveal a narrow size distribution of the silver cores with a mean radius of RC = 3.0 nm and a distribution width of 0.6 nm. Dynamic light scattering (DLS) provides a hydrodynamic radius of RH = 10.0 nm and a PDI of 0.09. The surface of the particles is covered with poly(acrylic acid) (PAA) forming a shell with a thickness of 7.0 nm, which provides colloidal stability lasting for more than six months at ambient conditions. It is foreseen to use these thoroughly characterized particles as reference material to compare the catalytic and biological properties of functionalized silver nanoparticles. The stabilizing ligand PAA can be easily exchanged by biomolecules to modify the surface functionality. Replacements of PAA with glutathione (GSH) and bovine serum albumin (BSA) have been performed as examples. We demonstrate that the particles effectively catalyze the reduction of 4-nitrophenol to 4-aminophenol with sodium borohydride. With PAA as stabilizer, the catalytic activity of (436 ± 24) L g-1 s-1 is the highest reported in literature for silver nanoparticles. GSH and BSA passivate the surface substantially resulting in lower catalytic activities of (77.6 ± 0.9) L g-1 s-1 and (3.47 ± 0.50) L g-1 s-1, respectively. The ultra-small particles were already used in the Nano Define project. Due to their small size it is possible to investigate the detection limits of different analytical techniques like electron microcopy, field flow fractionation or single particle tracking. In this project they serve as the calibration standard with the smallest radius. T2 - International summer school “Nanoscience meets Metrology” CY - Turin, Italy DA - 04.09.2016 KW - Protein coating KW - SAXS KW - Ligand exchange PY - 2016 AN - OPUS4-37352 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Meyer, Klas A1 - Kern, Simon A1 - Zientek, Nicolai A1 - Guthausen, G. A1 - Maiwald, Michael T1 - Process control with compact NMR N2 - Compact nuclear magnetic resonance (NMR) instruments make NMR spectroscopy and relaxometry accessible in industrial and harsh environments for reaction and process control. An increasing number of applications are reported. To build an interdisciplinary bridge between “process control” and “compact NMR”,we give a short overviewon current developments in the field of process Engineering such as modern process design, integrated processes, intensified processes along with requirements to process control, model based control, or soft sensing. Finally, robust field integration of NMR systems into processes environments, facing explosion protection or Integration into process control systems, are briefly discussed. KW - Prozessanalytik KW - Quantitative NMR-Spektroskopie KW - Industrie 4.0 KW - Reaction monitoring KW - Process control KW - Online NMR spectroscopy KW - Compact NMR PY - 2016 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-373562 UR - http://www.sciencedirect.com/science/article/pii/S0165993616300073 DO - https://doi.org/10.1016/j.trac.2016.03.016 SN - 0165-9936 VL - 83 IS - Part A / SI SP - 39 EP - 52 PB - Elsevier AN - OPUS4-37356 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hübert, Thomas T1 - Gas sensors for technical safety and process control N2 - The presentation gives an overview on sensor principles and materials. Examples for sensor application in technical safety and process control were presented and the contribution of BAM in sensor testing, validation and standadization are discussed. T2 - Vortrag in der Abteilung Physik des ITS (Institute Technology Surabaya) CY - Surabaya, Indonesia DA - 29-08-2016 KW - Gas sensor KW - Safety KW - Process control PY - 2016 AN - OPUS4-37358 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schönhals, Andreas T1 - Broadband Dielectric Spectroscopy - Basics and Selected Applications N2 - The basics of broadband dielectric spectroscopy were introduced in detail. The analysis of the data was discussed. As application of broadband dielectric spectroscopy the alpha-relaxation (dynamic glass transition) and the chain dynamics of polymers were ilustrated. T2 - 9th International Conference on Broadband Dielectric Spectroscopy and its Applications CY - Pisa, Italy DA - 11.09.2016 KW - Broadband Dielectric Spectroscopy PY - 2016 AN - OPUS4-37386 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schönhals, Andreas T1 - Behavior of Ultra-Thin Films of Blends of Polystyrene/ Poly(vinyl methyl ether) by Nanosized Relaxation Spectroscopy N2 - In the course of miniaturizing modern technology down to the molecular scale, understanding the materials behavior has to be investigated and deviations from the bulk that might arises from confinement effects has to be understood. Here, a combination of nano-sized relaxation spectroscopies (Broadband dielectric spectroscopy (BDS) and Specific heat spectroscopy (SHS); employing AC nanochip calorimetry) were utilized to investigate the glassy dynamics of ultra-thin films of blends of Poly (vinyl methyl ether) (PVME) / Polystyrene (PS) 50:50 wt-%, which are miscible bulk (thicknesses: 8nm - 200nm, film thickness was controlled by ellipsometry, film topography by AFM). Both methods are sensitive to different probes; where SHS senses entropy fluctuations while BDS measures dipole fluctuations. For BDS measurements, a recently developed nano-structured electrode sample arrangement is employed; where ultra-thin films are spin-coated on an ultra-flat highly conductive silicon wafer, sandwiched between a wafer with nanostructured SiO2 nano-spacers with heights between 35 nm and 70 nm. The method was applied for film thicknesses up to 50 nm. For thicker films, the samples were prepared between crossed electrodes. It was proven that, for 50 nm films, both contact methods will lead to identical results. By measuring the dynamic Tg in dependence of the film thickness, SHS showed that the Tg of the whole film was strongly influenced by a nanometer-thick surface layer at the polymer/air interface due to a self-assembling process [1]. The dynamic Tg obtained from the SHS measurements decrease with decreasing film thickness, evidencing the importance of a mobile surface layer at the polymer/air interface for the glass transition of the whole film. Compared to the SHS results, the BDS measurements show a completely different behavior. At high temperatures, the temperature dependence of the relaxation times of the films follows that of bulk-like PS/PVME; obeying the VFT-law. With decreasing temperature, the temperature dependence deviates from the VFT to an Arrhenius law; where the apparent activation energy decreases with decreasing film thickness. This is the first example where confinement induced changes were observed by BDS for ultra-thin films. All results were analyzed in details in a comprehensive discussion. T2 - 9th International Conference on Broadband Dielectric Spectroscopy and its Applications CY - Pisa, Italy DA - 11.09.2016 KW - Ultra-Thin films KW - Broadband Dielectric Spectrscopy KW - Nanostructured Electrodes PY - 2016 AN - OPUS4-37387 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kern, Simon T1 - Ugly Spectra and Lousy interfaces – Challenges for Compact NMR Spectroscopy in Process Control N2 - With the introduction of advanced process analytical technology, the closeness of key process variables to their limits can be directly controlled and the product can be classified or even released in real time. Compact NMR instruments can make NMR spectroscopy accessible in industrial and harsh environments for process control. T2 - ProcessNet-Jahrestagung und 32. DECHEMA-Jahrestagung der Biotechnologen 2016 CY - Aachen, Germany DA - 12.09.2016 KW - Industrie 4.0 KW - CONSENS KW - Reaction Monitoring KW - Smart Sensors KW - Online NMR Spectroscopy KW - Lithiation PY - 2016 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-373895 AN - OPUS4-37389 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Beck, Uwe ED - Baier, Jennifa ED - Sahre, Mario ED - Weise, Matthias ED - Dähne, L. ED - Lerche, K.-H. T1 - Plasma Compatibility of Particles for Functional PVD-coatings by ex-situ Injection - Stability of Particles under Plasma Conditions N2 - The validation of the plasma compatibility of particles is a prerequisite for their application in plasma dispersion layers. The goal is the realization of functional add-on features on surfaces, in films and coatings. Although intended applications primarily address nanoparticles, the compatibility tests were carried out at first with particles in the lower micrometer range in order to investigate material-, fluorescent marker- or surface-based degradation effects in a simple manner. Plasma compatibility implies at least the short-term acceptance of charged species, plasma-UV radiation, vacuum and elevated temperatures. Otherwise, effects on geometrical dimensions, chemical bonds, fluorescence efficiency and plastic-elastic properties are expected. The plasma compatibility of monodisperse fluorescent-labeled particles to microwave excitation was evaluated by means of microscopic and spectroscopic investigation methods (light, fluorescence, confocal, atomic force microscopy and FTIR). This study comprises particles of different materials (SiO2, PMMA, PS, MF) and sizes (from 50 nm to 10 μm). A special preparation technique ensures that smallest geometry changes of particles can be measured by atomic force microscopy. For the selected plasma conditions (P = 600 W, f = 2.46 GHz, d = 10 cm) and an exposure time of 10 minutes, the geometry of SiO2 particles (approx. 1.7 μm) remains nearly unchanged, whereas PS particles shrink in diameter by 6% and PMMA particles by 11%. For selected core-particles (SiO2, MF) with fluorescencemarked (rhodamine) shell-polyelectrolytes no remarkable plasma degradation of the fluorescence intensity was observed for the above mentioned plasma conditions, however a doubling of exposure time already results in a significant decrease in intensity. Two different injection systems have been studied for the particle injection into the plasma deposition process. One of the selected systems also proves process compatibility regarding the expected pressure differences upon injection. T2 - PARTEC 2016, International Congress on Particle Technology CY - Nürnberg, Germany DA - 19.04.2016 KW - plasma dispersion layers KW - functional PVD coatings KW - particle injection PY - 2016 SN - 978-3-18-092283-6 SN - 0083-5560 SP - 6. Applications of Particle Technology/6.11_Beck_Uwe PB - VDI Wissensforum GmbH CY - Düsseldorf AN - OPUS4-37265 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Färber, C. A1 - Titschack, J. A1 - Schönberg, Chr. H. L. A1 - Ehrig, Karsten A1 - Boos, K. A1 - Illerhaus, Bernhard A1 - Asgaard, U. A1 - Bromley, R. G. A1 - Freiwald, A. A1 - Wisshak, M. ED - Bahn, M. ED - Fennel, K. ED - Kesselmeier, J. ED - Naqvi, S. W. A. T1 - Long-term macrobioerosion in the Mediterranean Sea assessed by micro-computed tomography N2 - Biological erosion is a key process for the recycling of carbonate and the formation of calcareous sediments in the oceans. Experimental studies showed that bioerosion is subject to distinct temporal variability, but previous long-term studies were restricted to tropical waters. Here, we present results from a 14-year bioerosion experiment that was carried out along the rocky limestone coast of the island of Rhodes, Greece, in the Eastern Mediterranean Sea, in order to monitor the pace at which bioerosion affects carbonate substrate and the sequence of colonisation by bioeroding organisms. Internal macrobioerosion was visualised and quantified by micro-computed tomography and computer-algorithm-based segmentation procedures. Analysis of internal macrobioerosion traces revealed a dominance of bioeroding sponges producing eight types of characteristic Entobia cavity networks, which were matched to five different clionaid sponges by spicule identification in extracted tissue. The morphology of the entobians strongly varied depending on the species of the producing sponge, its ontogenetic stage, available space, and competition by other bioeroders. An early community developed during the first 5 years of exposure with initially very low macrobioerosion rates and was followed by an intermediate stage when sponges formed large and more diverse entobians and bioerosion rates in-creased. After 14 years, 30 % of the block volumes were occupied by boring sponges, yielding maximum bioerosion rates of 900 g m. KW - Bioerosion KW - Computed tomography KW - Carbonate substrate PY - 2016 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-372709 UR - http://www.biogeosciences.net/13/3461/2016/bg-13-3461-2016.pdf DO - https://doi.org/10.5194/bg-13-3461-2016 VL - 13 IS - 11 SP - 3461 EP - 3474 PB - Copernicus Publications CY - Göttingen AN - OPUS4-37270 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bierstedt, Andreas T1 - Development and characterization of an airborne laser-spark ion source for ambient desorption / ionization mass spectrometry N2 - A novel direct sampling ionization scheme for ambient mass spectrometry is presented. Desorption and ionization is achieved by a quasi-continuous laser induced plasma in air. Since there are no solid or liquid electrodes involved the ion source does not suffer from chemical interferences or fatigue originating from erosive burning or from electrode consumption. A laser plasma was ignited under ambient conditions in front of a modified TOF MS atmospheric pressure interface, using a high repetition rate DPSS laser operating at 532 nm and 26 kHz and an aspherical lens with a focal length of 8 mm. Emission spectroscopy (40-1100 nm) and time resolved studies on specific plasma parameters revealed insight into the physical and chemical plasma properties. Plasma ignition can be performed in rare gases and under ambient conditions. The hot plasma zone was kept at a certain distance from the sample region. Thus, effective collisional cooling seemed to prevent thermal fragmentation. Every single spark generates a shockwave, providing new reactive species, which expands concentrically from the hot region. Under ambient conditions primary charge carriers (ions and electrons) as well as VUV radiation initialize reaction cascades equivalent to other ambient ionization methods, such as DART or DBD. Mass spectra of polar/nonpolar hydrocarbons, sugars, pharmaceuticals and natural biomolecules in food were observed. Comprehensive emission spectroscopic measurements and time resolved electron current studies revealed insight into some plasma properties, such as the emitted high energetic radiation and the time evolution of the expanding plume. T2 - International Mass Spectrometry Conference 2016 CY - Toronto, ON, Canada DA - 20.08.2016 KW - laser-spark KW - laser-induced plasma KW - ambient mass spectrometry KW - emission spectroscopy PY - 2016 AN - OPUS4-37281 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schäferling, Michael T1 - Nanoprobes for sensing and imaging of intracellular pH based on polyethyleneimide-coated photon upconversion nanoparticles conjugated to a pH sensitive rhodamine dye N2 - Lanthanide-doped photon upconversion nanoparticles (UCNPs) exhibit many advantages compared to Stokes-shifted luminescent probes (organic dyes, quantum dots). Due to the upconversion process, the limitations of photobleaching, autofluorescence and low penetration depths in tissue shown by classical fluorescent probes are avoided. This makes UCNPs particularly useful for applications in complex biological samples. Sensing of intracellular pH is of particular interest in biomedical research since structure and function of biomolecules strongly depend on the concentration of protons in their environment. T2 - UPCON 2016 CY - Wroclaw, Poland DA - 23.05.2016 KW - upconversion KW - nanoprobes KW - chemical sensing PY - 2016 AN - OPUS4-37282 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schäferling, Michael T1 - Sensing and Imaging of Intracellular pH Using Polyethyleneimine-coated Photon Upconversion Based Nanoprobes N2 - Lanthanide-doped photon upconversion nanoparticles (UCNPs) exhibit many advantages compared to conventional Stokes-shifted luminescent probes such as organic dyes and quantum dots. Due to the upconversion (UC) process, which describes the conversion of NIR light into shorter wavelength radiation, the limitations of photobleaching, autofluorescence and low penetration depths in tissue shown by classical fluorescent probes absorbing in the UV/vis range are avoided. This makes UCNPs particularly useful for applications in complex samples occurring in bioanalysis, biomedicine and imaging. Sensing of intracellular pH is of particular interest in biomedical research since structure and function of biomolecules strongly depend on the concentration of protons in their environment. We described previously a UCNP nanosensor for pH based on a resonance energy transfer from hexagonal nanocrystals of NaYF4: Yb3+,Er3+ to a pH-sensitive fluorophore (pHrodoTM Red).[1] The nanocrystals were coated with a thin shell of aminosilane with several nanometer layer thickness for coupling of the pH indicator. In this contribution we present a new generation of UC nanoprobes that are coated with a layer of highly branched polyethylenimine (PEI). The PEI coating enables a higher coupling of indicator molecules on the particle surface, better signal to reference ratios in ratiometric readout and an improved cellular uptake compared to the aminosilane coated particles due to a more positive zeta potential. Again, pHrodoTM Red is used as pH indicator, sensitized by the 550 nm emission of the UCNPs. The nanoprobes are calibrated by ratiometric dual wavelength readout at 550 nm (reference signal) and 590 nm (sensor signal) and visualized using a scanning confocal fluorescence microscope with 980 nm excitation wavelength. We studied the cellular uptake efficacy of the nanoprobes and determined to which type of compartment, lysosomes, endosomes or cytosol, the probes are targeted to by measuring the pH of their microenvironment. An in situ control was performed in live cells by a treatment with nigericin, whereby the pH of all intracellular compartments is set at extracellular level. Our results suggest that the PEI coating facilitated endosomal escape of the nanoprobes. T2 - Europtrode XIII CY - Graz, Austria DA - 20.03.2016 KW - upconversion KW - chemical sensing KW - nanoprobes PY - 2016 AN - OPUS4-37283 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Bierstedt, Andreas A1 - Riedel, Jens T1 - Airborne laser-spark for ambient desorption/ionisation N2 - A novel direct sampling ionisation scheme for ambient mass spectrometry is presented. Desorption and ionisation are achieved by a quasi-continuous laser induced plasma in air. Since there are no solid or liquid electrodes involved the ion source does not suffer from chemical interferences or fatigue originating from erosive burning or from electrode consumption. The overall plasma maintains electro-neutrality, minimising charge effects and accompanying long term drift of the charged particles trajectories. In the airborne plasma approach the ambient air not only serves as the plasma medium but at the same time also slows down the nascent ions via collisional cooling. Ionisation of the analyte molecules does not occur in the plasma itself but is induced by interaction with nascent ionic fragments, electrons and/or far ultraviolet photons in the plasma vicinity. At each individual air-spark an audible shockwave is formed, providing new reactive species, which expands concentrically and, thus, prevents direct contact of the analyte with the hot region inside the plasma itself. As a consequence the interaction volume between plasma and analyte does not exceed the threshold temperature for thermal dissociation or fragmentation. Experimentally this indirect ionisation scheme is demonstrated to be widely unspecific to the chemical nature of the analyte and to hardly result in any fragmentation of the studied molecules. A vast ensemble of different test analytes including polar and non-polar hydrocarbons, sugars, low mass active ingredients of pharmaceuticals as well as natural biomolecules in food samples directly out of their complex matrices could be shown to yield easily accessible yet meaningful spectra. Since the plasma medium is humid air, the chemical reaction mechanism of the ionisation is likely to be similar to other ambient ionisation techniques. N2 - Wir stellen hier eine neue Ionisationsmethode für die Umgebungsionisation (ambient ionisation) vor. Sowohl die Desorption als auch die Ionisation erfolgen hierbei durch ein laserbetriebenes Luftplasma. Die Abwesenheit fester oder flüssiger Elektroden hat zur Folge, dass die Methode weder unter chemischen Interferenzen noch unter Verschleiß durch Korrosionsbrand oder abgetragenes Elektrodenmaterial leidet. Insgesamt betrachtet herrscht in dem Plasma Elektroneutralität, wodurch Aufladungseffekte minimiert werden, die andernfalls zu einer langfristigenÄderung der Flugbahnen von Ionen während der Experimente führen kann. In dem Ansatz eine freischwebende Luftentladung bei Atmosphärendruck zu verwenden agiert die Luft nicht nur als Plasmamedium sondert dient zusätzlich als Badgas für die stoßinduzierte Kühlung der entstehenden Ionen. Die Ionisierung der Analytmoleküle erfolgt nicht unmittelbar im Plasma sondern in dessen direkter Umgebung durch Wechselwirkung mit freigesetzten ionischen Luftspezies, freien Elektronen oder Photonen im kurzwelligen ultravioletten Bereich. Jede Laserentladung erzeugt eine hörbare Stoßwelle, in welcher neu produzierte reaktive Spezies freigesetzt werden, welche sich konzentrisch ausbreiten, so dass eine Diffusion der Analytmoleküle ins heiße Innere des Plasmas verhindert wird. Daraus folgt, dass im Interaktionsvolumen zwischen Plasma und Analyt der Temperaturgrenzwert für eine thermische Dissoziation oder Fragmentierung der Moleküle nicht überschritten wird. Experimentell konnte belegt werden, dass das vorgestellte Ionisierungsschema sehr unselektiv bezüglich der chemischen Analytklasse ist und kaum Fragmentierungsprodukte beobachtet werden können. Messungen einer breitgefächerten Auswahl unterschiedlicher Testsubstanzen, wie beispielsweise polarer und unpolarer Kohlenwasserstoffe, Zuckern, niedermolekularer pharmazeutischer Wirkstoffe, sowie natürlicher Biomoleküle in Lebensmittelproben unmittelbar aus ihren komplexen Matrizes, führten zu aussagekräftigen Massenspektren. Zumal das Lasermedium feuchte Luft ist, scheint der Reaktionsmechanismus dem anderer Atmosphärendruckionisierungsmethoden zuähneln. KW - Laser-spark KW - Laser-induced plasma KW - DPSS laser KW - High repetition rate KW - Ambient mass spectrometry KW - Time-of-flight mass spectrometry KW - Ionisation PY - 2016 DO - https://doi.org/10.1255/ejms.1417 SN - 1469-0667 VL - 22 IS - 3 SP - 105 EP - 114 PB - IM Publications LLP CY - Chichester, UK AN - OPUS4-37286 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Pollakowski, B. T1 - Qualifying PDMS deposited on silicon wafer surfaces as calibration standard for organic matter by X-ray spectrometry and XPS N2 - Polydimethylsiloxane (PDMS)is one of the most appearing contamination of medical devices.Dedicated analysis of PDMS on surfaces necessary, but the lack of calibration samples provides a bottle neck. There is a demand for metrological tools ensuring traceable and reliable analysis of mass deposition and of the chemical species of contaminants. Photoelectron spectroscopy (PES) and reference-free GIXRF can be used to qualify bench top instrumentation. Comparison of PES data and GIXRF data enable the establishment of a traceability chain. T2 - EXRS 2016, European Conference on X - ray Spectrometry CY - Gothenburg, Sweden DA - 19.06.2016 KW - Silicone analysis KW - XPS KW - GIXRF PY - 2016 AN - OPUS4-37295 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Köppe, Enrico T1 - Magnetic field detection with an advanced FBG-based sensor device N2 - A high-performance fiber Bragg grating-based (FBG) sensor device for the detection of small magnetic fields has been developed. Based on a smart multilayer coating exposed over the physical length of the FBG, magnetic fields exhibited by rotating machine parts, power generators or current cable can easily be detected, analysed and evaluated. Consequently, this innovative, in-process and non-contact inspection method leads to an increase in quality and reliability of high-performing machine parts, devices and cables. The basic physical concept is based on a magnetostrictive multilayer coating system that strains the high-resolution FBG element. Subsequently, a fixed relationship between induced magnetic field and wavelength change of the FBG element forms the characteristic sensitivity curve. Intensive tests regarding the characterisation of the magnetic field FBG sensor have been carried out and its performance has been evaluated. T2 - EuroSensors XXX 2016 CY - Budapest, Hungary DA - 04.09.2016 KW - Strain KW - Fiber Bragg grating KW - Magnetostriction KW - Magnetic field PY - 2016 AN - OPUS4-37364 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bertin, Annabelle T1 - Endowing nanoparticles with orthogonal functionalities via core / shell / shell architecture N2 - Dual orthogonal functionality in a single material is highly desirable in many fields such as bio-imaging, sensing, coating or diagnostic and therapy. However, combining two different functionalities in a precise and controlled way is still a challenging task. Here we present how simply dual functional hybrid nanoparticles consisting of a silica core with a fluorescent and a thermoresponsive polymeric layers can be prepared. As a first step of this work, silica core particles were coated by a fluorescent layer using surface-initiated reversible addition-fragmentation chain transfer polymerization. Afterwards, the fluorescent silica nanoparticles were completely enclosed in a switchable protective coating made of thermoresponsive poly(N-isopropylacrylamide). The thermoresponsive poly(N-isopropylacrylamide) changes its properties with varying the surroundings temperature and this behavior is reversible and controllable. To the best of our knowledge these types of hybrid dual functional core-shell-shell nanoparticles have not yet been prepared, despite the prospect of many potential applications. T2 - World Congress on Living Polymerizations and Polymers - LPP16 CY - Budapest, Hungary DA - 29.05.2016 KW - Fluorescent and thermoresponsive nanoparticles KW - Core KW - Shell KW - Shell nanoparticles PY - 2016 AN - OPUS4-37367 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bertin, Annabelle T1 - Endowing nanoparticles with orthogonal functionalities via core / shell / shell architecture N2 - Dual orthogonal functionality in a single material is highly desirable in many fields such as bio-imaging, sensing, coating or diagnostic and therapy. However, combining two different functionalities in a precise and controlled way is still a challenging task. Here we present how simply dual functional hybrid nanoparticles consisting of a silica core with a fluorescent and a thermoresponsive polymeric layers can be prepared. As a first step of this work, silica core particles were coated by a fluorescent layer using surface-initiated reversible addition-fragmentation chain transfer polymerization. Afterwards, the fluorescent silica nanoparticles were completely enclosed in a switchable protective coating made of thermoresponsive poly(N-isopropylacrylamide). The thermoresponsive poly(N-isopropylacrylamide) changes its properties with varying the surroundings temperature and this behavior is reversible and controllable. To the best of our knowledge these types of hybrid dual functional core-shell-shell nanoparticles have not yet been prepared, despite the prospect of many potential applications. T2 - 251st American Chemical Society National Meeting CY - San Diego, USA DA - 13.03.2016 KW - Fluorescent and thermoresponsive nanoparticles KW - Core / shell / shell / nanoparticles PY - 2016 AN - OPUS4-37370 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Rackwitz, J. A1 - Kopyra, J. A1 - Dabkowska, I. A1 - Ebel, K. A1 - Rankovic, M. A1 - Milosavljevic, A. R. A1 - Bald, Ilko T1 - Sensitizing DNAtowards low-energy electrons with 2-fluoroadenine N2 - 2-Fluoroadenine (2FA) is a therapeutic agent, which is suggested for application in cancer radiotherapy. The molecular mechanism of DNA radiation damage can be ascribed to a significant extent to the action of low-energy (<20 eV) electrons (LEEs), which damage DNA by dissociative electron attachment. LEE induced reactions in 2FA are characterized both isolated in the gas phase and in the condensed phase when it is incorporated into DNA. Information about negative ion resonances and anion-mediated fragmentation reactions is combined with an absolute quantification of DNA strand breaks in 2FA-containing oligonucleotides upon irradiation with LEEs. The incorporation of 2FA into DNA results in an enhanced strand breakage. The strand-break cross sections are clearly energy dependent, whereas the strand-break enhancements by 2FA at 5.5, 10, and 15 eV are very similar. Thus, 2FA can be considered an effective radiosensitizer operative at a wide range of electron energies. KW - Ab initio calculations KW - Dissociative electron attachment KW - DNA origami KW - DNA radiation damage KW - Fludarabine PY - 2016 UR - http://onlinelibrary.wiley.com/doi/10.1002/anie.201603464/full DO - https://doi.org/10.1002/anie.201603464 SN - 1433-7851 SN - 1521-3773 VL - 55 IS - 35 SP - 10248 EP - 10252 AN - OPUS4-37372 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Sobol, Oded A1 - Holzlechner, Gerald A1 - Nolze, Gert A1 - Wirth, Thomas A1 - Eliezer, D. A1 - Böllinghaus, Thomas A1 - Unger, Wolfgang T1 - Time-of-Flight secondary ion mass spectrometry (ToF-SIMS) imaging of deuterium assisted cracking in a 2205 duplex stainless steel microstructure N2 - In the present work, the influence of deuterium on the microstructure of a duplex stainless steel type EN 1.4462 has been characterized by Time-of-Flight Secondary Ion Mass Spectrometry (ToF-SIMS) supported by scanning electron microscopy (SEM), focused ion beam (FIB), electron back scattered diffraction(EBSD) and energy dispersive x-ray (EDX) investigations. Characterization has been carried out before and after electrochemical charging with deuterium which has been used as a tracer, due to its similar behavior to hydrogen in the steel microstructure. In a first approach, the distribution of the deuterium occurring at temperatures above 58 °C has been visualized. Further it turned out that sub-surface micro blisters are formed in the ferrite-austenite interface, followed by the formation of needle shaped plates and subsequent cracking at the ferrite surface. In the austenite phase, parallel cracking alongside twins and hexagonal close packed (martensitic) regions has been observed. In both phases and even in the apparent interface, cracking has been associated with high deuterium concentrations, as compared to the surrounding undamaged microstructure. Sub-surface blistering in the ferrite has to be attributed to the accumulation and recombination of deuterium at the ferrite-austenite interface underneath the respective ferrite grains and after fast diffusing through this phase. Generally, the present application of chemometric imaging and structural analyses allows characterization of hydrogen assisted degradation at a sub-micron lateral resolution. KW - ToF-SIMS KW - Hydrogen assisted cracking KW - Hydrogen embrittlement KW - SEM KW - FIB KW - EBSD PY - 2016 UR - http://www.sciencedirect.com/science/article/pii/S0921509316310334 DO - https://doi.org/10.1016/j.msea.2016.08.107 SN - 0921-5093 VL - 676 SP - 271 EP - 277 PB - Elsevier B.V. AN - OPUS4-37298 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kern, Simon A1 - Meyer, Klas A1 - Paul, Andrea A1 - Maiwald, Michael T1 - Ugly Spectra and Lousy interfaces – Challenges for Compact NMR Spectroscopy in Process Control N2 - With the introduction of advanced process analytical technology, the closeness of key process variables to their limits can be directly controlled and the product can be classified or even released in real time. Compact NMR instruments can make NMR spectroscopy accessible in industrial and harsh environments for process control. T2 - ProcessNet-Jahrestagung und 32. DECHEMA-Jahrestagung der Biotechnologen 2016 CY - Aachen, Germany DA - 12.09.2016 KW - Online NMR Spectroscopy KW - Smart Sensors KW - Industrie 4.0 KW - Reaction Monitoring PY - 2016 UR - http://onlinelibrary.wiley.com/doi/10.1002/cite.201650243/full DO - https://doi.org/10.1002/cite.201650243 SN - 1522-2640 VL - 88 SP - 1304 EP - 1317 PB - Wiley-VCH Verlag GmbH & Co. KGaA CY - Weinheim AN - OPUS4-37317 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Moser, Marko T1 - Quantification of PEG-Maleimide Ligands and Coupling Efficiencies on Nanoparticles with Ellman’s Reagent N2 - Emissive nanoparticles (NP) are of ever increasing importance in nanotechnology, optical industries, and life sciences. Applicationrelevant properties determining particle performance and biocompatibility depend mainly on surface functional groups or ligands. Coating with polyethylene glycol (PEG) ligands enhances hydrophilicity and biocompatibility of nanomaterials, and enables subsequent binding of biomolecules. Hence, PEGylated particles must be carefully engineered and monitored with simple and fast methods. T2 - 9th Meeting of Engineering of Functional Interfaces CY - Wildau, Germany DA - 03.07.2016 KW - PEG-Maleimide KW - Ellman PY - 2016 AN - OPUS4-37247 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Asadujjaman, Asad T1 - Endowing nanoparticles with orthogonal functionalities via a core/shell/shell architecture N2 - Dual orthogonal functionalities in a single material is highly desirable in many fields such as bio-imaging, sensing, coating or diagnostic and therapy. However, a precise and controlled approach to prepare two different functionalities is still a challenging task. Herein, we show the simple preparation method for the synthesis of dual-functional hybrid core/shell/shell nanoparticles consisting of a silica core with a fluorescent and a thermoresponsive polymeric layer. Silica core particles were first coated by a fluorescent layer using surface- nitiated reversible addition-fragmentation chain transfer (RAFT) polymerization. The fluorescent silica nanoparticles were then completely enclosed within a switchable protective coating made of thermoresponsive poly(N-isopropylacrylamide) via RAFT polymerization. Thermoresponsive poly(N-isopropylacrylamide) is known to change its properties according to the surroundings temperature in a reversible and controllable way (LCST behavior). The successful preparation of well-defined dual-functional hybrid core/shell/shell nanoparticles was shown by scanning electron microscopy, thermogravimetric analysis and Fourier transform infrared spectroscopy, while their fluorescence and thermoresponsive properties were confirmed by fluorescence spectroscopy and dynamic light scattering measurements, respectively. T2 - Macromolecular Colloquium 2016 CY - Freiburg, Germany DA - 24.02.2016 KW - Polymer KW - thermoresponsive PY - 2016 AN - OPUS4-35473 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Myrach, Philipp A1 - Maierhofer, Christiane A1 - Rahammer, M. A1 - Kreutzbruck, Marc T1 - Parameters in lock-in thermography of CFRP laminates N2 - Active thermography with lock-in excitation is a non-destructive testing method that is also feasible for testing of carbon fiber reinforced polymers (CFRP). For validating the method extensive investigations were done during a research project in order to advance a standardization process. The most important parameters of optical and ultrasonic excitation thermography were investigated. For example, the appropriate selection of spectral sensitivity of the used infrared camera systems is important for recording undisturbed thermal signals. Regarding excitation, influences of excitation power and ultrasonic frequency were studied. Furthermore, material parameters such as CFRP layup are known for strongly affecting the results of measurement. KW - Standardisierung KW - Lock-in thermography KW - Lock-in Thermografie KW - CFRP KW - CFK KW - optical excitation KW - ultrasonic excitation KW - Ultraschall KW - standardization PY - 2016 DO - https://doi.org/10.3139/120.110814 SN - 0025-5300 VL - 58 IS - 1 SP - 31 EP - 35 PB - Carl Hanser Verlag CY - München AN - OPUS4-35479 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Jonietz, Florian A1 - Myrach, Philipp A1 - Suwala, H. A1 - Ziegler, Mathias T1 - Examination of Spot Welded Joints with Active Thermography N2 - The method described here allows to determine the size of the thermal contact between two metal sheets joined by spot welding. This size is a measure for the size of the weld nugget, i.e. the zone melted during the welding process, and thus the quality of the welded joint. The method applies active thermography in transmission or reflection setup. Especially the reflection setup offers an attractive possibility for non-destructive testing when components can be accessed from one side only. The spot weld region is optically heated by laser or flash light radiation. The weld nugget provides the mechanical joint, but also constitutes a thermal bridge between the two welded sheets. The latter will be exploited in this method. The better thermal contact at the weld Nugget contrasts with the surrounding material, where the heat transfer between the two sheets is comparatively low. A major advantage of the described method is the applicability on sheets without any surface treatment. This is achieved by a proper normalization of the data, allowing for a correction of the varying surface emissivity. KW - Active thermography KW - Spot weld KW - Automotive industry PY - 2016 UR - http://link.springer.com/article/10.1007/s10921-015-0318-4?wt_mc=internal.event.1.SEM.ArticleAuthorIncrementalIssue DO - https://doi.org/10.1007/s10921-015-0318-4 VL - 35:1 SP - 1 EP - 14 PB - Springer CY - New York AN - OPUS4-35480 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Helmecke, E. A1 - Fleßner, M. A1 - Kaufmann, M. A1 - Staude, Andreas A1 - Hausotte, T. T1 - Numerical measurement uncertainty determination for dimensional measurements of microparts with CT N2 - Up to now, the only standardized method to determine the measurement uncertainty for computed tomography (CT) is to use calibrated workpieces as specified in the Guideline VDI/VDE 2630 Part 2.1. This paper discusses a promising numerical method for uncertainty determination with help of a virtual metrological CT (VMCT). It gives an explanation of the adjustments, the input parameters and the execution of the simulation. Furthermore, it discusses the first results of uncertainty determination compared to the method of using calibrated workpieces with the aid of two example cases. T2 - 6th Conference on Industrial Computed Tomography (iCT) CY - Wels, Austria DA - 09.02.2016 KW - simulation KW - Simulation KW - Computertomographie KW - Dimensionelle Metrologie KW - Normung KW - numerische Messunsicherheitsbestimmung KW - computed tomography KW - dimensional metrology KW - standardization KW - numerical uncertainty determination PY - 2016 UR - http://www.ndt.net/article/ctc2016/papers/ICT2016_paper_id17.pdf SP - Paper ID17, 1 EP - 7 AN - OPUS4-35481 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Rothbart, Nick A1 - Maierhofer, Christiane A1 - Goldammer, M. A1 - Hohlstein, F. A1 - Koch, J. A1 - Kryukov, I. A1 - Mahler, G. A1 - Stotter, B. A1 - Oswald-Tranta, B. A1 - Sengebusch, M. T1 - A round robin test of flash thermography of CFRP and metal structures N2 - Within the scope of a DIN INS project, a flash thermography round robin test that evaluates reliability, comparability and efficiency of different testing situations is organized. The results give information about the detectability of defects e.g. by their size and depth, the evaluation method and by the materials used. Besides, the influence of equipment and parameters used by the participants on the results were analysed. All of the quantitative results as well as the feedback given by the participants will be presented in a DIN committee in order to contribute to a flash thermography standard. T2 - 7th International Symposium on NDT in Aerospace CY - Bremen, Germany DA - 16.11.2015 KW - Flash thermography KW - Round robin test KW - Metal KW - Flat bottom holes KW - SNR PY - 2016 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-351070 UR - https://www.ndt.net/?id=18921 SN - 1435-4934 VL - 21 IS - 4 SP - 1 EP - 8 PB - NDT.net CY - Kirchwald AN - OPUS4-35107 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - BOOK A1 - Hübert, Thomas A1 - Boon-Brett, L. A1 - Buttner, W. J. T1 - Sensors for Safety and Process Control in Hydrogen Technologies N2 - This book is on sensors which are regularly deployed in technologies and processes related to hydrogen production, storage, distribution, and use. Not all types of sensors are equally suitable for specific hydrogen applications. The information in this book is intended to help the reader understand the basics of sensors, sensing technologies, sensor applications, and to provide guidelines for choosing the right sensors and the use of them correctly. Correct deployment of appropriate sensors demands knowledge of the sensing principle and of the physical or chemical quantities being measured. Because of the properties of hydrogen, the potential for its vastly increased use in a future low-carbon economy and possible hazards associated with its use, special attention is paid to hydrogen sensors. This book will not focus on the details of the hydrogen technologies nor on the many safety-related aspects of these technologies. Many books are already available on these topics. Instead the detection principle of hydrogen sensors and other sensor types used, in the dynamic and rapidly developing field of hydrogen technologies, are treated in detail in this book. In the first chapter a brief overview is presented on basic hydrogen properties and particularly on those properties which are most relevant for safety and for sensing. To illustrate the extensive field of contemporary applications and the exciting possibilities for near future sensor applications, existing and emerging markets using large quantities of hydrogen are mentioned. The role of sensors as devices for monitoring and control of processes and as safety monitoring devices is outlined. The second chapter gives an introduction to sensing technology and provides the Reader with relevant information pertaining to sensor definitions and classification, sensor metrics, and performance arameters, in addition to background information on sensor preparation technologies and techniques. While there are many books available which provide more exhaustive information on each of these topics, e.g., the level of detail provided in this chapter is sufficient to appreciate the salient features of sensing and sensing Technology which are central to hydrogen safety and monitoring of relevant applications. Chapter 3 provides a comprehensive overview of emerging and commercially available hydrogen sensors, an explanation of their sensing principle, and important aspects of their performance. A comprehensive and up-to-date account of the theory (physical or chemical principles), design, and practical implementations of hydrogen sensors for use in hydrogen related applications is presented. Similar information on chemical sensors for other gases, such as oxygen and trace components, which are also highly important in hydrogen technologies because of potential hazards to human health, process safety or facility performance, is provided in Chapter 4. In Chapter 5 descriptions of physical sensors for temperature, pressure, gas flow, and fire indication, which are also germane for the safe use of hydrogen, are provided. Standards, codes, and regulatory documents, which provide practical advice and legislative requirements regarding sensor deployment and performance, are described in Chapter 6. This chapter also makes reference to the main procedures for sensor testing in gas Standards including precise analytical methods and reference methods. The chapter concludes with a discussion on sensor selection and some installation guidelines are provided. In Chapter 7 traditional and emerging processes and technologies involving hydrogen are described. The application of sensors in processes for the production of hydrogen, hydrogen storage, distribution, and the use of hydrogen in stationary and mobile fuel cells is discussed. Furthermore, the use of hydrogen as a coolant and chemical reagent (medium) in various processes is described. The exploitation of sensors for replacing traditional analytical instrumentation is also discussed. Finally supplementary information is provided on hydrogen properties, measuring quantities, and sensor parameters. KW - Hydrogen Technologies KW - Hydrogen Sensors KW - Gas Sensors, Safety KW - Process Control PY - 2016 SN - 978-1-4665-9654-2 SP - 1 EP - 414 PB - CRC Press Taylor & Francis Group CY - Boca Raton, Florida, USA AN - OPUS4-35507 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Greer, B. A1 - McNamee, S.E. A1 - Boots, B. A1 - Cimarelli, L. A1 - Guillebault, D. A1 - Helmi, K. A1 - Marcheggiani, S. A1 - Panaiotov, S. A1 - Breitenbach, U. A1 - Akcaalan, R. A1 - Medlin, L.K. A1 - Kittler, Katrin A1 - Elliott, C.T. A1 - Campbell, K. T1 - A validated UPLC–MS/MS method for the surveillance of ten aquatic biotoxins in European brackish and freshwater systems N2 - Over the past few decades, there has been an increased frequency and duration of cyanobacterial Harmful Algal Blooms (HABs) in freshwater systems globally. These can produce secondary metabolites called cyanotoxins, many of which are hepatotoxins, raising concerns about repeated exposure through ingestion of contaminated drinking water or food or through recreational activities such as bathing/swimming. An ultra-performance liquid chromatography tandem mass spectrometry (UPLC–MS/MS) multi-toxin method has been developed and validated for freshwater cyanotoxins; microcystins-LR, -YR, -RR, -LA, -LY and -LF, nodularin, cylindrospermopsin, anatoxin-a and the marine diatom toxin domoic acid. Separation was achieved in around 9 min and dual SPE was incorporated providing detection Limits of between 0.3 and 5.6 ng/L of original sample. Intra- and inter-day precision analysis showed relative standard deviations (RSD) of 1.2–9.6% and 1.3 –12.0% respectively. The method was applied to the analysis of aquatic samples (n = 206) from six European countries. The main class detected were the hepatotoxins; microcystin-YR (n = 22), cylindrospermopsin (n = 25), microcystin-RR (n = 17), micro-cystin-LR (n = 12), microcystin-LY (n = 1), microcystin-LF (n = 1) and nodularin (n = 5). For microcystins, the levels detected ranged from 0.001 to 1.51 mg/L, with two samples showing combined levels above the guideline set by the WHO of 1 mg/L for microcystin-LR. Several samples presented with multiple Toxins indicating the potential for synergistic effects and possibly enhanced toxicity. This is the first published pan European survey of freshwater bodies for multiple biotoxins, including two identified for the first time; cylindrospermopsin in Ireland and nodularin in Germany, presenting further incentives for improved monitoring and development of strategies to mitigate human exposure. KW - Biotoxins - Biotoxine KW - Harmful Algal Bloom (HAB) KW - UPLC-MS/MS PY - 2016 DO - https://doi.org/10.1016/j.hal.2016.01.006 SN - 1568-9883 VL - 55 SP - 31 EP - 40 PB - Elsevier CY - Amsterdam AN - OPUS4-35515 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -