TY - JOUR
A1 - Eckel, S.
A1 - Zscherpel, Uwe
A1 - Huthwaite, P.
A1 - Paul, N.
A1 - Schumm, A.
T1 - Radiographic film system classification and noise characterisation by a camera-based digitisation procedure
N2 - Extracting statistical characteristics from radiographic films is vital for film system classification and contrast sensitivity evaluation and serves as a basis for film noise simulation. A new method for digitising radiographic films in order to extract these characteristics is presented. The method consists of a camera-based setup and image processing procedure to digitise films. Correct optical density values and granularity can be extracted from the digitised images, which are equal to results obtained by standardised measurement procedures. Specific statistical characteristics of film noise are theoretically derived and subsequently verified by the obtained data, including characteristics such as Gaussianity and spatial spectral characteristics of the optical density fluctuations. It is shown that the presented method correctly measures the granularity of film noise and can therefore replace time-consuming microdensitometer measurements traditionally required for film system classifications. Additionally, the inherent unsharpness of film systems was investigated and compared with literature data. This comparison serves as another validation approach of the presented method.
KW - Radiography
KW - Image processing
KW - Film noise
KW - Film system classification
KW - Digitisation
PY - 2020
DO - https://doi.org/10.1016/j.ndteint.2020.102241
SN - 0963-8695
VL - 111
IS - 4
SP - 102241
PB - Elsevier Ltd.
CY - Amsterdam
AN - OPUS4-50517
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Eckel, S.
A1 - Huthwaite, P.
A1 - Zscherpel, Uwe
A1 - Schumm, A.
A1 - Paul, N.
T1 - Realistic film noise generation based on experimental noise spectra
N2 - Generating 2D noise with local, space-varying spectral characteristics is vital where random noise fields with spatially heterogeneous statistical properties are observed and need to be simulated. A realistic, non-stationary noise generator relying on experimental data is presented. That generator is desired in areas such as photography and radiography. For example, before performing actual X-ray imaging in practice, output images are simulated to assess and improve setups. For that purpose, realistic film noise modelling is crucial because noise downgrades the detectability of visual signals. The presented film noise synthesiser improves the realism and value of radiographic simulations significantly, allowing more realistic assessments of radiographic test setups. The method respects space-varying spectral characteristics and probability distributions, locally simulating noise with realistic granularity and contrast. The benefits of this approach are to respect the correlation between noise and image as well as internal correlation, the fast generation of any number of unique noise samples, the exploitation of real experimental data, and its statistical non-stationarity. The combination of these benefits is not available in existing work. Validation of the new technique was undertaken in the field of industrial radiography. While applied to that field here, the technique is general and can also be utilised in any other field where the generation of 2D noise with local, space-varying statistical properties is necessary.
KW - Nondestructive testing
KW - Image quality
KW - Noise simulation
KW - Radiography
PY - 2020
DO - https://doi.org/10.1109/TIP.2019.2955284
SN - 1057-7149
VL - 29
SP - 2987
EP - 2998
PB - IEEE Xplore
CY - Washington, D.C.
AN - OPUS4-50518
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Dittmann, Daniel
A1 - Eisentraut, Paul
A1 - Goedecke, Caroline
A1 - Wiesner, Yosri
A1 - Jekel, M
A1 - Ruhl, A S
A1 - Braun, Ulrike
T1 - Specific adsorption sites and conditions derived by thermal decomposition of activated carbons and adsorbed carbamazepine
N2 - The adsorption of organic micropollutants onto activated carbon is a favourable solution for the treatment of drinking water and wastewater. However, these adsorption processes are not sufficiently understood to allow for the appropriate prediction of removal processes. In this study, thermogravimetric analysis, alongside evolved gas analysis, is proposed for the characterisation of micropollutants adsorbed on activated carbon. Varying amounts of carbamazepine were adsorbed onto three different activated carbons, which were subsequently dried, and their thermal decomposition mechanisms examined. The discovery of 55 different pyrolysis products allowed differentiations to be made between specific adsorption sites and conditions. However, the same adsorption mechanisms were found for all samples, which were enhanced by inorganic constituents and oxygen containing surface groups. Furthermore, increasing the loadings led to the evolution of more hydrated decomposition products, whilst parts of the carbamazepine molecules were also integrated into the carbon structure. It was also found that the chemical composition, especially the degree of dehydration of the activated carbon, plays an important role in the adsorption of carbamazepine. Hence, it is thought that the adsorption sites may have a higher adsorption energy for specific adsorbates, when the activated carbon can then potentially increase its degree of graphitisation.
KW - Aktivkohle
KW - TED-GC/MS
KW - Adsorption
KW - Thermoanalytik
PY - 2020
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-506946
DO - https://doi.org/10.1038/s41598-020-63481-y
VL - 10
IS - 1
SP - 6695
PB - Nature Publishing Group
AN - OPUS4-50694
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Dietrich, Paul
A1 - Streeck, C.
A1 - Glamsch, Stephan
A1 - Ehlert, Christopher
A1 - Lippitz, Andreas
A1 - Nutsch, A.
A1 - Kulak, N.
A1 - Beckhoff, B.
A1 - Unger, Wolfgang
T1 - Quantification of silane molecules on oxidized silicon: Are there options for a traceable and absolute determination?
N2 - Organosilanes are used routinely to functionalize various support materials for further modifications. Nevertheless, reliable quantitative information about surface functional group densities after layer formation is rarely available. Here, we present the analysis of thin organic nanolayers made from nitrogen containing silane molecules on naturally oxidized silicon wafers with reference-free total reflection X-ray fluorescence (TXRF) and X-ray photoelectron spectroscopy (XPS). An areic density of 2−4 silane molecules per nm2 was calculated from the layer’s nitrogen mass deposition per area unit obtained by reference-free TXRF. Complementary energy and angle-resolved XPS (ER/ARXPS) in the Si 2p core-level region was used to analyze the outermost surface region of the organic (silane layer)−inorganic (silicon wafer) interface. Different coexisting silicon species as silicon, native silicon oxide, and silane were identified and quantified. As a result of the presented proof-of-concept, absolute and traceable values for the areic density of silanes containing nitrogen as intrinsic marker are obtained by calibration of the XPS methods with reference-free TXRF. Furthermore, ER/AR-XPS is shown to facilitate the determination of areic densities in (mono)layers made from silanes having no heteroatomic marker other than silicon. After calibration with reference-free TXRF, these areic densities of silane molecules can be determined when using the XPS component intensity of the silane’s silicon atom.
PY - 2015
DO - https://doi.org/10.1021/acs.analchem.5b02846
SN - 0003-2700
SN - 1520-6882
VL - 87
IS - 19
SP - 10117
EP - 10124
PB - American Chemical Society
CY - Washington, DC
AN - OPUS4-34796
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Girard-Lauriault, P.-L.
A1 - Unger, Wolfgang
A1 - Dietrich, Paul
A1 - Holländer, A.
T1 - Innovative and established strategies for the surface analysis of nitrogen and oxygen-rich plasma polymer films by XPS: an introductory guide
N2 - Nitrogen- and oxygen-based plasma polymer films are materials with a complex and partially elusive surface chemistry. We present an overview of innovative and established X-ray photoelectron spectroscopy (XPS)-based analysis strategies developed to elucidate the surface chemistry of such films. We focus on both experimental methods and data analysis strategies and include the following topics: high-resolution spectra curve fitting, aging, chemical derivatization, and depth profiling by angle- and energy-resolved XPS.
KW - Chemical derivatization
KW - Functional groups
KW - Plasma polymerization
KW - X-ray photoelectron spectroscopy
PY - 2015
DO - https://doi.org/10.1002/ppap.201500115
SN - 1612-8850
SN - 1612-8869
VL - 12
IS - 9
SP - 953
EP - 967
PB - Wiley-VCH Verl.
CY - Weinheim
AN - OPUS4-35114
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Pech May, Nelson Wilbur
A1 - Paul, A.
A1 - Ziegler, Mathias
T1 - Pulse-compression laser thermography using a modified Barker code: Enhanced detection of subsurface defects
N2 - Pulse-compression thermography is an emerging technique that has shown versatility by combination of pulsed and lock-in thermography. Accordingly, several aspects of this technique are still unexplored, and some others not fully developed yet. Barker codes were widely used in radar applications due to their simplicity and their optimum autocorrelation function. Nevertheless, applications were limited by the amplitude of the sidelobes present in the autocorrelation function and therefore, several filters have been developed which aim to reduce the sidelobes. However, the filters usually depend on empirical parameters which must be determined for each application. A better alternative would improve the applicability of the Barker codes. In this work, we further develop the pulse-compression thermography technique by introducing a 13-bit modified Barker code (mBC): This allows to drastically reduce the sidelobes characteristic of the 13-bit Barker code (BC). Consequently, the thermographic impulse response, obtained by cross-correlation, is almost free of such sidelobes. Deeper defects become easier to detect in comparison with using a 13-bit Barker code. Numerical simulations using the finite element method are used for comparison and experimental measurements are performed in a sample of steel grade St 37 with machined notches of three different depths: 2 mm, 4 mm and 6 mm.
T2 - SPIE Defense + Commercial Sensing 2021
CY - Online meeting
DA - 13.04.2021
KW - Pulse-compression laser thermography
KW - Barker codes
KW - Non-destructive testing
PY - 2021
DO - https://doi.org/10.1117/12.2586078
SN - 0277-786X
VL - 11743
SP - 1
EP - 11
PB - SPIE
CY - Bellingham, Wash.
AN - OPUS4-53247
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Pech May, Nelson Wilbur
A1 - Paul, A.
A1 - Ziegler, Mathias
T1 - Pulse-compression laser thermography using a modified Barker code: Enhanced detection of subsurface defects
N2 - Pulse-compression thermography is an emerging technique that has shown versatility by combination of pulsed and lock-in thermography. Accordingly, several aspects of this technique are still unexplored, and some others not fully developed yet. Barker codes were widely used in radar applications due to their simplicity and their optimum autocorrelation function. Nevertheless, applications were limited by the amplitude of the sidelobes present in the autocorrelation function and therefore, several filters have been developed which aim to reduce the sidelobes. However, the filters usually depend on empirical parameters which must be determined for each application. A better alternative would improve the applicability of the Barker codes. In this work, we further develop the pulse-compression thermography technique by introducing a 13-bit modified Barker code (mBC): This allows to drastically reduce the sidelobes characteristic of the 13-bit Barker code (BC). Consequently, the thermographic impulse response, obtained by cross-correlation, is almost free of such sidelobes. Deeper defects become easier to detect in comparison with using a 13-bit Barker code. Numerical simulations using the finite element method are used for comparison and experimental measurements are performed in a sample of steel grade St 37 with machined notches of three different depths: 2 mm, 4 mm and 6 mm.
T2 - SPIE Defense + Commercial Sensing 2021
CY - Online meeting
DA - 13.04.2021
KW - Pulse-compression laser thermography
KW - Barker codes
KW - Non-destructive testing
PY - 2021
AN - OPUS4-53249
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Singh, S.
A1 - Palani, I. A.
A1 - Paul, C. P.
A1 - Funk, Alexander
A1 - Gokuldoss, P. K.
T1 - Wire Arc Additive Manufacturing of NiTi 4D Structures: Influence of Interlayer Delay
N2 - Shape memory alloy structures for actuator and vibration damper applications may be manufactured using wire arc additive manufacturing (W AAM), which is one of the additive manufacturing technologies. Multilayer deposition causes heat accumulation during W AAM, which rises the preheat temperature of the previously created layer. This leads to process instabilities, which result in deviations from the desired dimensions and mechanical properties changes. During W AAM deposition of the wall structure, a systematic research is carried out by adjusting the interlayer delay from 10 to 30 s. When the delay period is increased from 10 to 30 s, the breadth decreases by 45% and the height increases by 33%. Grain refinement occurs when the interlayer delay duration is increased, resulting in better hardness, phase transformation temperature, compressive strength, and shape recovery behavior. This study shows how the interlayer delay affects the behavior of W AAM-built nickel-titanium alloy (NiTi) structures in a variety of applications.
KW - Wire are additive manufacturing
KW - Shape memory alloy
KW - Nitinol
KW - Interlayer delay
PY - 2022
DO - https://doi.org/10.1089/3dp.2021.0296
SN - 2329-7662
SP - 1
EP - 11
PB - Liebert
CY - New Rochelle, NY
AN - OPUS4-55795
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Kittner, Maria
A1 - Kerndorff, A.
A1 - Ricking, M.
A1 - Bednarz, M.
A1 - Obermaier, N.
A1 - Lukas, M.
A1 - Asenova, M.
A1 - Bordós, G.
A1 - Eisentraut, Paul
A1 - Hohenblum, P.
A1 - Hudcova, H.
A1 - Humer, F.
A1 - István, T. G.
A1 - Kirchner, M.
A1 - Marushevska, O.
A1 - Nemejcová, D.
A1 - Oswald, P.
A1 - Paunovic, M.
A1 - Sengl, M.
A1 - Slobodnik, J.
A1 - Spanowsky, K.
A1 - Tudorache, M.
A1 - Wagensonner, H.
A1 - Liska, I.
A1 - Braun, U.
A1 - Bannick, C. G.
T1 - Microplastics in the Danube River Basin: A First Comprehensive Screening with a Harmonized Analytical Approach
N2 - In this study, carried out within the Joint Danube Survey 4, a comprehensive microplastic screening in the water column within a large European river basin from its source to estuary, including major tributaries, was realized. The objective was to develop principles of a systematic and practicable microplastic monitoring strategy using sedimentation boxes for collection of suspended particulate matter followed by its subsequent analysis using thermal extraction desorption-gas chromatography/mass spectrometry. In total, 18 sampling sites in the Danube River Basin were investigated. The obtained suspended particulate matter samples were subdivided into the fractions of >100 μm and <100 μm and subsequently analyzed for microplastic mass contents. The results showed that microplastics were detected in all samples, with polyethylene being the predominant polymer with maximum contents of 22.24 μg/mg, 3.23 μg/mg for polystyrene, 1.03 μg/mg for styrene-butadiene-rubber, and 0.45 μg/mg for polypropylene. Further, polymers such as different sorts of polyester, polyacrylates, polylactide, and natural rubber were not detected or below the detection limit. Additional investigations on possible interference of polyethylene signals by algae-derived fatty acids were assessed. In the context of targeted monitoring, repeated measurements provide more certainty in the interpretation of the results for the individual sites. Nevertheless, it can be stated that the chosen approach using an integrative sampling and determination of total plastic content proved to be successful.
KW - Thermal extraction desorption-gas chromatography/mass spectrometry (TED-GC/MS), monitoring
KW - Microplastics
KW - River
KW - Suspended particulate matter (SPM)
KW - Sedimentation box (SB)
PY - 2022
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-551444
DO - https://doi.org/10.1021/acsestwater.1c00439
VL - 2
IS - 7
SP - 1174
EP - 1181
PB - ACS Publications
AN - OPUS4-55144
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Godard, A.
A1 - Kalot, G.
A1 - Privat, M.
A1 - Bendellaa, M.
A1 - Busser, B.
A1 - Wegner, Karl David
A1 - Denat, F.
A1 - Le Guevel, X.
A1 - Coll, J.-L.
A1 - Paul, C.
A1 - Bodio, E.
A1 - Goze, C.
A1 - Sancey, L.
T1 - NIR-II Aza-BODIPY Dyes Bioconjugated to Monoclonal Antibody Trastuzumab for Selective Imaging of HER2-Positive Ovarian Cancer
N2 - Using fluorescence-guided surgery (FGS) to cytoreductive surgery helps achieving complete resection of microscopic ovarian tumors. The use of visible and NIR-I fluorophores has led to beneficial results in clinical trials; however, involving NIR-II dyes seems to outperform those benefits due to the deeper tissue imaging and higher signal/noise ratio attained within the NIR-II optical window. In this context, we developed NIR-II emitting dyes targeting human epidermal growth factor receptor 2 (HER2)-positive ovarian tumors by coupling water-soluble NIR-II aza-BODIPY dyes to the FDA-approved anti-HER2 antibody, namely, trastuzumab. These bioconjugated NIR-II-emitting dyes displayed a prolonged stability in serum and a maintained affinity toward HER2 in vitro. We obtained selective targeting of HER2 positive tumors (SKOV-3) in vivo, with a favorable tumor accumulation. We demonstrated the fluorescence properties and the specific HER2 binding of the bioconjugated dyes in vivo and thus their potential for NIR-II FGS in the cancer setting.
KW - NIR-II
KW - Fluorescent dye
KW - In vivo imaging
KW - Ovarian cancer
KW - Antibody conjuagtes
KW - Bioimaging
PY - 2023
DO - https://doi.org/10.1021/acs.jmedchem.3c00100
SN - 0022-2623
VL - 66
IS - 7
SP - 5185
EP - 5195
PB - ACS Publications
AN - OPUS4-57293
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Chazeau, E.
A1 - Fabre, C.
A1 - Privat, M.
A1 - Godard, A.
A1 - Racoeur, C.
A1 - Bodio, E.
A1 - Busser, B.
A1 - Wegner, Karl David
A1 - Sancey, L.
A1 - Paul, C.
A1 - Goze, C.
T1 - Comparison of the In Vitro and In Vivo Behavior of a Series of NIR-II-Emitting Aza-BODIPYs Containing Different Water-Solubilizing Groups and Their Trastuzumab Antibody Conjugates
N2 - The development of new fluorescent organic probes effective in the NIR-II region is currently a fast-growing field and represents a challenge in the domain of medical imaging. In this study, we have designed and synthesized an innovative series of aza-boron dipyrromethenes emitting in the NIR-II region. We have investigated the effect of different water-solubilizing groups not only on the photophysical properties of the compounds but also on their in vitro and in vivo performance after bioconjugation to the antibody trastuzumab. Remarkably, we discovered that the most lipophilic compound unexpectedly displayed the most favorable in vivo properties after bioconjugation. This underlines the profound influence that the fluorophore functionalization approach can have on the efficiency of the resulting imaging agent.
KW - NIR-II
KW - In vivo imaging
KW - Fluorescence
KW - Spectroscopy
KW - Antibody conjugates
PY - 2024
DO - https://doi.org/10.1021/acs.jmedchem.3c02139
SN - 1520-4804
VL - 67
IS - 5
SP - 3679
EP - 3691
PB - ACS Publications
CY - Washington, DC
AN - OPUS4-59607
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Davison, Nathan
A1 - Hemingway, Jack M.
A1 - Wills, Corinne
A1 - Stolar, Tomislav
A1 - Waddell, Paul G.
A1 - Dixon, Casey M.
A1 - Barron, Luke
A1 - Dawson, James A.
A1 - Lu, Erli
T1 - Mechanochemical Synthesis of a Sodium Anion Complex [Na+(2,2,2-cryptand)Na–] and Studies of Its Reactivity: Two-Electron and One-Electron Reductions
N2 - Group 1 metal molecular chemistry is dominated by a +1 oxidation state, while a 0 oxidation state is widespread in the metals. A more exotic, yet still available, oxidation state of group 1 metal is −1, i.e., alkalide. Reported as early as the 1970s, the alkalides appear in every modern inorganic chemistry textbook as an iconic chemical curiosity, yet their reactivity remains unexplored. This is due to their synthetic hurdles. In this work, we report the first facile synthesis of the archetypical alkalide complex, [Na+(2,2,2-cryptand)Na–], which allows us to unveil a versatile reactivity profile of this once exotic species.
KW - Mechanochemistry
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-608632
DO - https://doi.org/10.1021/acs.inorgchem.4c02914
VL - 63
IS - 32
SP - 15247
EP - 15258
PB - American Chemical Society (ACS)
AN - OPUS4-60863
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Klamrowski, Günter
A1 - Neustupny, Paul
A1 - Zajc, A.
ED - Sneck, T.
T1 - Degree of moisture saturation and mechanical properties of concrete
T2 - Third International Conference on the Durability of Building Materials and Components
CY - Espoo, Finland
DA - 12.08.1984
PY - 1984
SP - 500
EP - 509
CY - Espoo
AN - OPUS4-36800
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Rosemann, Paul
A1 - Müller, Christina
A1 - Meyer, A.
A1 - Halle, T.
T1 - Influence of nitrogen on the corrosion resistance of martensitic stainless steels
N2 - The corrosion resistance of martensitic stainless steels (MSS) depends strongly on the chemical composition and the applied heat treatment. Both determines the distribution of the alloying elements in the microstructure and the resulting material properties. The addition of nitrogen is known to be beneficial for the pitting corrosion resistance of stainless steels. In case of MSS this effect is not only connected to nitrogen itself because nitrogen can be used to substitute carbon which also influences the result of the heat treatment process. This paper shows the effect of nitrogen on the corrosion resistance in relation to the hardening process of MSS. Therefore the effects of austenitization duration, austenitization temperature and cooling rate on microstructure, hardness and corrosion resistance were studied on the MSS X30CrMoN15 1 and X50CrMoV15. The effect of different cooling rates was studied in the range of > 100 K/s down to 1 K/s using the jominy end quench test. The changes in corrosion resistance were detected with electrochemical potentiodynamic reactivation (EPR) and by the determination of critical pitting potentials. Besides this experimental approach thermodynamic calculations with the software thermocalc will be presented and used for the interpretation of the effect of nitrogen on the corrosion resistance of MSS.
T2 - 18th Chemnitz Seminar on Materials Engineering – 18. Werkstofftechnisches Kolloquium
CY - Chemnitz, Germany
KW - Martensitic stainless steels
KW - Corrosion resistance
KW - Heat treatment
PY - 2016
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-366956
DO - https://doi.org/10.1088/1757-899X/118/1/011002
VL - 118
IS - 1
SP - 19
EP - 19
PB - IOP Publishing
AN - OPUS4-36695
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Heyn, A.
A1 - Rosemann, Paul
A1 - Babutzka, Martin
A1 - Bender, S.
T1 - Electrochemical noise of unalloyed steel in mixtures of water-based binders and pigments
N2 - The development of organic coatings for corrosion protection is an elaborate process with a multitude of often interminable investigations and tests of protection properties. Electrochemical methods support the processes of development to a great extent and help to understand mechanisms of action and failure. They are usually carried out on applied coating systems with a completed formulation. An examination possibility is presented in this publication that enables the characterization of waterbased coatings with different formulation variations in the liquid (aqueous) state with the aid of electrochemical noise technique. Thus, selection of binders, pigments, and other additives is supported essentially and made more efficient in a very early Phase of formulation development. The paper shows that a unique insight into the dynamic processes of a metal in contact with an aqueous coating dispersion is possible using the example of the development of zinc-free corrosion-inhibiting pigments for waterbased coatings. In addition, it is presented in which way the results correlate with the performance of applied coatings.
KW - Organic coatings
KW - Electrochemical noise
KW - Corrosion
KW - Corrosion protection
KW - Corrosion protection pigments
PY - 2017
DO - https://doi.org/10.1002/maco.201709671
SN - 0947-5117
SN - 1521-4176
VL - 68
IS - 12
SP - 1295
EP - 1301
PB - Wiley-VCH Verlag
CY - Weinheim
AN - OPUS4-43319
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Hüllmann, Dino
A1 - Paul, Niels
A1 - Kohlhoff, Harald
A1 - Neumann, Patrick P.
A1 - Lilienthal, A. J.
ED - Eberhardsteiner, J.
ED - Růžička, M.
ED - Cosmi, F.
T1 - Measuring rotor speed for wind vector estimation on multirotor aircraft
N2 - For several applications involving multirotor aircraft, it is crucial to know both the direction and speed of the ambient wind. In this paper, an approach to wind vector estimation based on an equilibrium of the principal forces acting on the aircraft is shown. As the thrust force generated by the rotors depends on their rotational speed, a sensor to measure this quantity is required. Two concepts for such a sensor are presented: One is based on tapping the signal carrying the speed setpoint for the motor controllers, the other one uses phototransistors placed underneath the rotor blades. While some complications were encountered with the first approach, the second yields accurate measurement data. This is shown by an experiment comparing the proposed speed sensor to a commercial non-contact tachometer.
T2 - 34th Danubia Adria Symposium on Advances in Experimental Mechanics
CY - Trieste, Italy
DA - 19.09.2017
KW - Wind vector estimation
KW - Rotor speed
KW - UAV
KW - Tachometer
PY - 2018
UR - https://www.sciencedirect.com/science/article/pii/S2214785318321114
DO - https://doi.org/10.1016/j.matpr.2018.08.139
SN - 2214-7853
VL - 5
IS - 13
SP - 26703
EP - 26708
PB - Elsevier
CY - Amsterdam, Netherlands
AN - OPUS4-47097
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Kauss, N.
A1 - Heyn, A.
A1 - Rosemann, Paul
T1 - How to Detect Sensitivity on Aged Lean-Duplex Stainless Steel With Electrochemical Methods
N2 - The influence of isothermal ageing on microstructure, sensitisation and pitting corrosion resistance of the lean duplex stainless steel (LDSS) X2CrNiN23-4 was investigated with various electrochemical methods. The aging at 600 °C (from 0.1 h up to 20 h) lead to the formation of precipitations at the ferrite-ferrite (α/α) and ferrite-austenite (α/γ) grain boundaries, inducing sensitisation due to chromium depletion. The degree of sensitisation was evaluated with the double loop electrochemical potentiokinetic reactivation method (DL-EPR) according to ASTM G108 and correlated with critical pitting potentials (Epit) as well as critical pitting temperature (CPT) measured in an electrolyte according to ASTM G48 using electrochemical noise. Up to an ageing time of 1 h, the sensitisation did rise significantly, stabilising at a nearly constant level with a slight drop at 20 h. This behaviour correlated perfectly with the potentiodynamically determined pitting potentials Epit and sensitisation. The CPT showed a higher sensitivity at short ageing times compared to the DL-EPR and Epit. Finally, the KorroPad method was applied to visualise the sensitisation induced reduction of pitting corrosion resistance. The “KorroPad” is an agar-based gel-electrolyte containing 0.1 mol/l sodium chloride (NaCl) and 0.1 mol/l potassium ferricyanide III (K3[Fe(CN)6]), invented at the Federal Institute of Materials Research and Testing in Berlin (Germany) to detect surfaces of stainless steel prone to pitting corrosion. The standard configuration of the KorroPad showed no differentiation for the various aging conditions. Increasing the concentration of both NaCl and potassium ferrocyanide III to 0.5 M shifts the detection limit of the KorroPad method to stainless steels with higher corrosion resistance, producing the same trends detected by standard electrochemical pitting corrosion values (Epit, CPT) and sensitisation (DL-EPR). By that, the KorroPad method was successfully adjusted to the lean-duplex stainless steel X2CrNiN23-4, enabling short-time testing to detect sensitization.
T2 - Electrochemical Methods in Corrosion Research 2018
CY - Cambridge, UK
DA - 22.07.2018
KW - Corrosion testing
KW - Duplex stainless steels
KW - Corrosion
KW - KorroPad
KW - Pitting corrosion
KW - EPR
KW - Electrochemical noise
KW - Stainless steel
PY - 2018
AN - OPUS4-45615
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Rosemann, Paul
A1 - Müller, C.
A1 - Roßberg, S.
A1 - Pensel, P.
A1 - Halle, T.
A1 - Burkert, A.
T1 - Precipitation behavior and corrosion resistance of nickel-free, high-nitrogen austenitic stainless steels
N2 - Nickel-free, nitrogen alloyed austenitic stainless-steels, with about 19 wt.-% Mn and 0,8 wt. % N, are an interesting alternative to classic CrNi austenitic stainless steels due to their superior mechanical properties (Rm > 900 MPa, A5 > 50 %, Av > 350 J) in the solution annealed condition. The formation of chromium-rich nitrides during suboptimal heat treatment, processing or application leads to an inhomogeneous distribution of alloying elements in the microstructure, which reduces the corrosion resistance. Consequently, an accurate knowledge of the sensitization behavior is indispensable for the use of nickel-free, high-nitrogen austenitic stainless steels. The relationship between artificial aging, phase formation and corrosion resistance was investigated on the alloys X8CrMnN18-19 (1.3815) and X8CrMnMoN18-19-2 (1.4456), both alloyed with 0,8 wt.-% Nitrogen, in the present work. The microstructural evolution was studied by LM and SEM while the corrosion resistance was characterized with the electrochemical potentiodynamic reactivation (EPR) and the KorroPad indicator-test. Both alloys showed increased corrosion susceptibility within critical aging parameters. Finally, a sensitization diagram was described successfully for both alloys showing the positive effect of molybdenum.
T2 - EUROCORR 2018
CY - Krakow, Poland
DA - 09.09.2018
KW - Corrosion
KW - KorroPad
KW - Stainless steel
KW - Corrosion resistance
KW - Heat treatment
KW - ThermoCalc
KW - Pitting corrosion
KW - Nitrogen
PY - 2018
AN - OPUS4-45954
LA - deu
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Eisentraut, Paul
A1 - Dümichen, Erik
A1 - Ruhl, A.
A1 - Jekel, M.
A1 - Albrecht, M.
A1 - Gehde, M.
A1 - Braun, Ulrike
T1 - Two Birds with One Stone-Fast and Simultaneous Analysis of Microplastics: Microparticles Derived from Thermoplastics and Tire Wear
N2 - Analysis of microplastic particles (MP) in environmental samples needs sophisticated techniques and is time intensive due to sample preparation and detection. An alternative to the most common (micro ) spectroscopic techniques, FTIR or Raman spectroscopy, are the thermoanalytical methods, where specific decomposition products can be analyzed as marker compounds for different kind of plastics types and mass contents. Thermal extraction desorption gas chromatography mass spectrometry (TED-GC-MS) allows the fast identification and quantification of MP in environmental samples without sample preparation. Whereas up to now only the analysis of thermoplastic polymers was realized, this is the first time that even the analysis of tire wear (TW) content in environmental samples is possible. Various marker compounds for TW were identified. They include characteristic decomposition products of elastomers, antioxidants and vulcanization agents. Advantages and drawbacks of these marker substances were evaluated. Environmental samples from street run off were exemplarily investigated and presented.
KW - TED-GC-MS
KW - Microplastic
KW - Tire wear
PY - 2018
DO - https://doi.org/10.1021/acs.estlett.8b00446
VL - 5
IS - 10
SP - 608
EP - 613
PB - American Chemical Society
AN - OPUS4-46460
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Grötzsch, D.
A1 - Streeck, C.
A1 - Nietzold, Carolin
A1 - Malzer, W.
A1 - Mantouvalou, I.
A1 - Nutsch, A.
A1 - Dietrich, Paul
A1 - Unger, Wolfgang
A1 - Beckhoff, B.
A1 - Kanngießer, B.
T1 - A sealable ultrathin window sample cell for the study of liquids by means of soft X-ray spectroscopy
N2 - A new sample cell concept for the analysis of liquids or solid-liquid interfaces using soft X-ray spectroscopy is presented, which enables the complete sealing of the cell as well as the Transport into vacuum via, for example, a load-lock system. The cell uses pressure monitoring and active as well as passive pressure regulation systems, thereby facilitating the full control over the pressure during filling, sealing, evacuation, and measurement. The cell design and sample preparation as well as the crucial sealing procedure are explained in detail. As a first proof-of-principle experiment, successful nitrogen K-edge fluorescence yield near-edge X-ray absorption fine structure experiments of a biomolecular solution are presented. For this purpose, it is shown that the careful evaluation of all involved parameters, such as window type or photon flux, is desirable for optimizing the experimental result.
KW - X-ray spectroscopy
KW - Analysis of liquids
KW - Wet cell
KW - Concanavalin A
KW - NEXAFS
PY - 2017
DO - https://doi.org/10.1063/1.5006122
SN - 0034-6748
SN - 1089-7623
VL - 88
IS - 12
SP - 123112-1
EP - 123112-7
PB - American Institute of Physics
AN - OPUS4-43611
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -