TY - JOUR
A1 - Riedel, Soraya
A1 - Jaut, Valerie
A1 - Schneider, Rudolf
T1 - Ergometrine sensing in rye flour by a magnetic bead-based immunoassay followed by flow injection analysis with amperometric detection
N2 - A certain group of mycotoxins, the ergot alkaloids, has caused countless deaths throughout human history. They are found in rye and other cereals and ingesting contaminated foods can cause serious health problems. To identify contaminated food exceeding the legal limits for ergot alkaloids, a portable and cost-effective test system is of great interest to the food industry. Rapid analysis can be achieved by screening for a marker compound, for which we chose ergometrine. We developed a magnetic bead-based immunoassay for ergometrine with amperometric detection in a flow injection system using a handheld potentiostat and a smartphone. With this assay a limit of detection of 3 nM (1 μg/L) was achieved. In spiked rye flour, ergometrine levels from 25 to 250 μg/kg could be quantified. All results could be verified by optical detection. The developed assay offers great promise to meet the demand for on-site ergometrine detection in the food industry.
KW - Ergot alkaloids
KW - Amperometry
KW - Magnetic beads
KW - Immunoassay
KW - Food analysis
KW - Fow injection analysis
KW - Mycotoxins
PY - 2023
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-565906
DO - https://doi.org/10.1016/j.talanta.2022.124172
SN - 0039-9140
N1 - Geburtsname von Riedel, Soraya: Höfs, S. - Birth name of Riedel, Soraya: Höfs, S.
VL - 254
IS - 124172
SP - 1
EP - 8
PB - Elsevier B.V.
AN - OPUS4-56590
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Malakhov, A.
A1 - Epishin, A.
A1 - Denisov, I.
A1 - Saikov, I.
A1 - Nolze, Gert
T1 - Morphology and Structure of Brass–Invar Weld Interface after Explosive Welding
N2 - This paper presents the results of a study of the morphology and structure at the weld interface in a brass–Invar bimetal, which belongs to the class of so-called thermostatic bimetals, or thermobimetals. The structure of the brass–Invar weld interface was analyzed using optical microscopy and scanning electron microscopy (SEM), with the use of energy-dispersive X-ray (EDX) spectrometry and back-scattered electron diffraction (BSE) to identify the phases. The distribution of the crystallographic orientation of the grains at the weld interface was obtained using an e-Flash HR electron back-scatter diffraction (EBSD) detector and a forward-scatter detector (FSD). The results of the study indicated that the weld interface had the wavy structure typical of explosive welding. The wave crests and troughs showed the presence of melted zones consisting of a disordered Cu–Zn–Fe–Ni solid solution and undissolved Invar particles. The pattern quality map showed that the structure of brass and Invar after explosive welding consisted of grains that were strongly elongated towards the area of the highest intensive plastic flow. In addition, numerous deformation twins, dislocation accumulations and shear bands were observed. Thus, based on the results of this study, the mechanism of Cu–Zn–Fe–Ni structure formation can be proposed.
KW - Explosive welding
KW - Thermobimetal
KW - Grain structure
KW - Brass
KW - Invar
PY - 2022
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-565964
DO - https://doi.org/10.3390/ma15238587
SN - 1996-1944
VL - 15
IS - 23
SP - 1
EP - 10
PB - MDPI
AN - OPUS4-56596
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Böttcher, Katrin
A1 - Schmitt Rahner, M.
A1 - Stolzenberg, U.
A1 - Kraft, Sebastian
A1 - Bonse, Jörn
A1 - Feist, C.
A1 - Albrecht, D.
A1 - Pullner, B.
A1 - Krüger, Jörg
T1 - Worst-case X-ray photon energies in ultrashort pulse laser processing
N2 - Ultrashort pulse laser processing can result in the secondary generation of unwanted X-rays if a critical laser irradiance of about 10^13 W/cm^2 is exceeded. Spectral X-ray emissions were investigated during the processing of tungsten and steel using three complementary spectrometers (based on CdTe and silicon drift detectors) simultaneously for the identification of a worst-case spectral scenario. Therefore, maximum X-ray photon energies were determined, and corresponding dose equivalent rates were calculated. An ultrashort pulse laser workstation with a pulse duration of 274 fs, a center wavelength of 1030 nm, pulse repetition rates between 50 kHz and 200 kHz, and a Gaussian laser beam focused to a spot diameter of 33 µm was employed in a single pulse and burst laser operation mode. Different combinations of laser pulse energy and repetition rate were utilized, keeping the average laser power constant close to the maximum power of 20 W. Peak irradiances ranging from 7.3 × 10^13 W/cm^2 up to 3.0 × 10^14 W/cm^2 were used. The X-ray dose equivalent rate increases for lower repetition rates and higher pulse energy if a constant average power is used. Laser processing with burst mode significantly increases the dose rates and the X-ray photon energies. A maximum X-ray photon energy of about 40 keV was observed for burst mode processing of tungsten with a repetition rate of 50 kHz and a peak irradiance of 3 × 10^14 W/cm^2.
KW - Ultrashort pulsed laser
KW - X-ray emission
KW - X-ray spectrum
KW - X-ray energies
KW - Radiation protection
PY - 2022
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-566176
DO - https://doi.org/10.3390/ma15248996
VL - 15
IS - 24
SP - 1
EP - 17
PB - MDPI
AN - OPUS4-56617
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Kinne, R. W.
A1 - Gunnella, F.
A1 - Kunisch, E.
A1 - Heinemann, S.
A1 - Nies, B.
A1 - Maenz, S.
A1 - Horbert, V.
A1 - Illerhaus, Bernhard
A1 - Huber, R.
A1 - Firkowska-Boden, I.
A1 - Bossert, J.
A1 - Jandt, K. D.
A1 - Sachse, A.
A1 - Bungartz, M.
A1 - Brinkmann, O.
T1 - Performance of calcium phosphate cements in the augmentation of sheep vertebrae - An ex vivo study
N2 - Oil-based calcium phosphate cement (Paste-CPC) shows not only prolonged shelf life and injection times, but also improved cohesion and reproducibility during application, while retaining the advantages of fast setting, mechanical strength, and biocompatibility. In addition, poly(L-lactideco-glycolide) (PLGA) fiber reinforcement may decrease the risk for local extrusion. Bone defects (diameter 5 mm; depth 15 mm) generated ex vivo in lumbar (L) spines of female Merino sheep (2–4 years) were augmented using: (i) water-based CPC with 10% PLGA fiber reinforcement (L3); (ii) Paste-CPC (L4); or (iii) clinically established polymethylmethacrylate (PMMA) bone cement (L5). Untouched (L1) and empty vertebrae (L2) served as controls. Cement performance was analyzed using micro-computed tomography, histology, and biomechanical testing. Extrusion was comparable for Paste-CPC(-PLGA) and PMMA, but significantly lower for CPC + PLGA. Compressive strength and Young’s modulus were similar for Paste-CPC and PMMA, but significantly higher compared to those for empty defects and/or CPC + PLGA. Expectedly, all experimental groups showed significantly or numerically lower compressive strength and Young’s modulus than those of untouched controls. Ready-to-use Paste-CPC demonstrates a performance similar to that of PMMA, but improved biomechanics compared to those of water-based CPC + PLGA, expanding the therapeutic arsenal for bone defects. O, significantly lower extrusion of CPC + PLGA fibers into adjacent lumbar spongiosa may help to reduce the risk of local extrusion in spinal surgery.
KW - Sheep
KW - PMMA
KW - Calcium phosphate bone cement
KW - Oil-based
KW - Ready-to-use
KW - Water-based
KW - Micro-CT
KW - Compressive strength
KW - Young’s modulus
PY - 2021
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-569072
DO - https://doi.org/10.3390/ma14143873
SN - 1996-1944
VL - 14
IS - 14
SP - 1
EP - 12
PB - MDPI
CY - Basel
AN - OPUS4-56907
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Mitu, M.
A1 - Razus, D.
A1 - Schröder, Volkmar
T1 - Laminar burning velocities of hydrogen-blended methane-air and natural gas-air mixtures, calculated from the early stage of p(t) records in a spherical vessel
N2 - The flammable hydrogen-blended methane–air and natural gas–air mixtures raise specific safety and environmental issues in the industry and transportation; therefore, their explosion characteristics such as the explosion limits, explosion pressures, and rates of pressure rise have significant importance from a safety point of view. At the same time, the laminar burning velocities are the most useful parameters for practical applications and in basic studies for the validation of reaction mechanisms and modeling turbulent combustion. In the present study, an experimental and numerical study of the effect of hydrogen addition on the laminar burning velocity (LBV) of methane–air and natural gas–air mixtures was conducted, using mixtures with equivalence ratios within 0.90 and 1.30 and various hydrogen fractions rH within 0.0 and 0.5. The experiments were performed in a 14 L spherical vessel with central ignition at ambient initial conditions. The LBVs were calculated from p(t) data, determined in accordance with EN 15967, by using only the early stage of flame propagation. The results show that hydrogen addition determines an increase in LBV for all examined binary flammable mixtures. The LBV variation versus the fraction of added hydrogen, rH, follows a linear trend only at moderate hydrogen fractions. The further increase in rH results in a stronger variation in LBV, as shown by both experimental and computed LBVs. Hydrogen addition significantly changes the thermal diffusivity of flammable CH4–air or NG–air mixtures, the rate of heat release, and the concentration of active radical species in the flame front and contribute, thus, to LBV variation.
KW - Hydrogen
KW - Methane
KW - Natural gas
KW - Laminar burning velocity (LBV)
KW - Closed vessel combustion
PY - 2021
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-569083
DO - https://doi.org/10.3390/en14227556
SN - 1996-1073
VL - 14
IS - 22
SP - 1
EP - 16
PB - MDPI
CY - Basel
AN - OPUS4-56908
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Neuhold, S.
A1 - Algermissen, D.
A1 - Drissen, P.
A1 - Adamczyk, Burkart
A1 - Presoly, P.
A1 - Sedlazeck, K. P.
A1 - Schenk, J.
A1 - Raith, J. G.
A1 - Pomberger, R.
A1 - Vollprecht, D.
T1 - Tailoring the FeO/SiO2 Ratio in Electric Arc Furnace Slags to Minimize the Leaching of Vanadium and Chromium
N2 - Based on recently published research on leaching control mechanisms in electric arc furnace (EAF) slags, it is assumed that a FeO/SiO2 ratio of around one leads to low leached V and Cr concentrations. This ratio influences the mineral phase composition of the slag toward higher amounts of spinel and a lower solubility of calcium silicate phases by suppressing the formation of magnesiowuestite and highly soluble calcium silicate phases. To evaluate this hypothesis, laboratory and scaled up tests in an EAF pilot plant were performed on slag samples characterized by elevated V and Cr leaching and a high FeO/SiO2 ratio. Prior to the melting experiments, the optimum FeO/SiO2 ratio was calculated via FactSageTM. In the melting experiments, the ratio was adjusted by adding quartz sand, which also decreased the basicity (CaO/SiO2) of the slag. As a reference, remelting experiments without quartz sand addition were conducted and additionally, the influence of the cooling rate of the slag was examined. The remelted (without quartz sand) and the remelted modified slags (with quartz sand) were analyzed chemically and mineralogically and the leaching behavior was investigated. The modification of the slags yielded a minimized release of V and Cr, supporting the hypothesis that the FeO/SiO2 ratio influences the mineralogy and the leaching behavior.
KW - Electric arc furnace (EAF) slags
KW - FactSageTM calculations
KW - Leaching control mechanisms
KW - Melting experiments
PY - 2020
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-571517
DO - https://doi.org/10.3390/app10072549
VL - 10
IS - 7
SP - 1
EP - 18
PB - MDPI
AN - OPUS4-57151
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Flierl, Lukas
A1 - Rienitz, Olaf
A1 - Vogl, Jochen
A1 - Pramann, Axel
T1 - An advancement of the gravimetric isotope mixture method rendering the knowledge of the spike purity superfluous
N2 - The gravimetric isotope mixture method is the primary method to determine absolute isotope ratios. This method, however, depends on the existence of suitable spike materials and knowledge of their purities. Determining the purity of the spikes can be tedious and labour-intensive. In this publication, an advancement of the gravimetric isotope mixture method, rendering the determination of the purity of the spike materials unnecessary, is presented. The advancement combines mass spectrometry and ion chromatography leading to an approach being independent of the purity of the spike materials. In the manuscript the mathematical background and the basic idea of the novel approach are described using a two-isotope system like copper or lithium.
KW - Isotope amount ratios
KW - Metrology
KW - Mass spectrometry
KW - Ion chromatography
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-608726
DO - https://doi.org/10.1007/s00216-024-05465-9
SP - 5325
EP - 5333
PB - Springer Science and Business Media LLC
AN - OPUS4-60872
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Stolar, Tomislav
A1 - Pearce, Ben K.D.
A1 - Etter, Martin
A1 - Truong, Khai-Nghi
A1 - Ostojić, Tea
A1 - Krajnc, Andraž
A1 - Mali, Gregor
A1 - Rossi, Barbara
A1 - Molčanov, Krešimir
A1 - Lončarić, Ivor
A1 - Meštrović, Ernest
A1 - Užarević, Krunoslav
A1 - Grisanti, Luca
T1 - Base-pairing of uracil and 2,6-diaminopurine: from cocrystals to photoreactivity
N2 - We show that the non-canonical nucleobase 2,6-diaminopurine (D) spontaneously base pairs with uracil (U) in water and the solid state without the need to be attached to the ribose-phosphate backbone. Depending on the reaction conditions, D and U assemble in thermodynamically stable hydrated and anhydrated D-U base-paired cocrystals. Under UV irradiation, an aqueous solution of D-U base-pair undergoes photochemical degradation, while a pure aqueous solution of U does not. Our simulations suggest that D may trigger the U photodimerization and show that complementary base-pairing modifies the photochemical properties of nucleobases, which might have implications for prebiotic chemistry.
KW - Mechanochemistry
KW - In situ monitoring
KW - Cocrystals
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-608622
DO - https://doi.org/10.1016/j.isci.2024.109894
VL - 27
IS - 6
SP - 1
EP - 14
PB - Elsevier Inc.
AN - OPUS4-60862
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 - JOUR
A1 - Giv, Ali Nemati
A1 - Asante, Bright
A1 - Yan, Libo
A1 - Kasal, Bohumil
T1 - Shear performance and durability of adhesively bonded spruce wood-concrete composite joints: Effects of indoor and outdoor environmental conditions, mechanical load, and their coupled effect
N2 - A long-term study was conducted on double-lap spruce wood-concrete joints to investigate their shear strength and stiffness over a 12-month period. These joints were manufactured using both wet and dry processes, each incorporating two adhesive types for bonding the wood to the concrete: a brittle epoxy and a ductile polyurethane (PUR). The experimental design exposed the joints to three specific long-term environments: (1) outdoor exposure, (2) indoor conditions with applied load, and (3) outdoor conditions with applied load. The wood concrete joints exposed to outdoor conditions were subjected to destructive shear testing at intervals of 0 (serving as the reference sample), 2, 4, 6, and 12 months, respectively. For joints subjected to both indoor and outdoor conditions with shear loading, the shear deformation of joints was monitored continuously over the 12 months before performing the destructive tests. A gradual reduction in the shear stiffness and strength of dry joints (produced using the dry bond method) exposed to outdoor conditions was observed over a 12-month period, primarily due to bond failure at the concrete-adhesive interface. The wet joints exhibited no degradation in shear stiffness and strength across long-term conditions over the same period. The bond failure observed in dry joints was predominantly associated with stresses arising from dimensional changes in the wood. No degradation was found in the cross-linking density of the adhesive or in the concrete’s compressive stiffness and strength.
KW - Adhesively bonded joints
KW - Long-term study
KW - Ductile PUR
KW - Brittle epoxy
KW - Outdoor condition
KW - Mechanical load
KW - Indoor condition
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-608878
DO - https://doi.org/10.1016/j.conbuildmat.2024.136905
VL - 436
SP - 1
EP - 22
PB - Elsevier BV
AN - OPUS4-60887
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Wegner, Karl David
A1 - Hildebrandt, N.
T1 - Near infrared quantum dots for biosensing and bioimaging
N2 - Quantum dots (QDs) possess unique optoelectronic properties, which make them very attractive to be used as optical probes in biosensing and bioimaging applications. The strong absorbance and light scattering of biological compounds like tissue and blood in the visible range pose a problem. However, if optical probes emitting in the near-infrared (NIR) range are used, scattering, absorption, and autofluorescence of biological components are strongly reduced. This allows for an increased light penetration depth and higher spatial and temporal resolution for the investigation of biological processes. The synthesis and application of NIR emitting QDs is a fast-growing research field and the benefits of using QDs were demonstrated for a variety of applications, such as photoelectrochemical biosensor, in vivo vascular imaging, and fluorescence-guided surgery. This article reviews the state-of-the-art developments in the preparation of NIR/IR QDs and highlights the latest research about their utilization in biosensing and bioimaging applications.
KW - Quantum dots
KW - Near-infrared
KW - Biosensing
KW - Bioimaging
KW - NIR-II / SWIR
KW - Advanced nanomaterials
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-609708
SN - 0165-9936
DO - https://doi.org/10.1016/j.trac.2024.117922
VL - 180
SP - 1
EP - 19
PB - Elsevier B.V.
AN - OPUS4-60970
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Mellios, Nikolaos
A1 - Kruschwitz, Sabine
A1 - Spyrdis, Panagiotis
T1 - Performance Prediction of Anchors in SFRC using Minimally Invasive and Non‐Destructive Techniques
N2 - AbstractFastenings are crucial for the upgrade of existing structures, by either enhancing structural components or modernising and expanding structures and structural systems. Whilst concrete is prevailing in the existing building stock, new types of concrete composites are increasingly used to improve the sustainability and overall structural performance of built assets. The addition of short dispersed fibres is a material technology with several applications. This paper addresses the synergy of fastening elements, introducing localised loads in concrete substrates, and of fibres, particularly in terms of the fibre orientation and density in the load application area, which is a significant quality aspect. The possibility to forecast this synergy based on non‐destructive or minimally invasive testing methods is an efficient tool to increase confidence in the design load‐bearing performance of the anchorages. Initially, previous literature and own investigations on such techniques are presented. Furthermore, a methodology is presented on associating such information to predict a single anchor's resistance on the basis of sophisticated non‐linear analyses and testing with engineered fibres alignments.
T2 - Annual Meeting of the European-Association-on-Quality-Control-of-Bridges-and-Structures (EUROSTRUCT)
CY - Vienna, Austria
DA - 25.09.2023
KW - Minimally-invasive evaluation
KW - Fastenings
KW - Anchorage to concrete
KW - Steel fibre reinforced concrete
KW - Non-destructive evaluation NDE
KW - Non-destructive testing NDT
PY - 2023
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-609223
DO - https://doi.org/10.1002/cepa.2115
VL - 69
IS - 5
SP - 1455
EP - 1463
PB - Wiley
AN - OPUS4-60922
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Schmitt, M.
A1 - Casperson, Ralf
A1 - Baensch, F.
A1 - Müller, D.
T1 - Nationale, europäische und internationale Normung in der zerstörungsfreien Prüfung
N2 - Normung und Standardisierung in der zerstörungsfreien Prüfung finden auf nationaler, europäischer und internationaler Ebene statt. Die Übernahme von Leitungsfunktionen in diesen Gremien erzeugt die Möglichkeit der Steuerung von Themen und Inhalten der relevanten Normen. Das persönliche Engagement der Fachexpert*innen in den nationalen Gremien und den europäischen und internationalen Arbeitsgruppen ist ein zusätzlicher Faktor für die inhaltliche Korrektheit und die inhaltliche Ausrichtung der Norm. Denn wer nicht normt, wird genormt und muss letztlich Normen anwenden, die andere entsprechend ihrer eigenen Interessen gestaltet haben. Voraussetzung für die Teilnahme in europäischen und internationalen Normungsgremien ist die Mitwirkung in den entsprechenden DINSpiegelgremien, welche die europäischen (CEN) und internationalen (ISO) Aktivitäten spiegeln und die Fachexpert*innen für die Mitarbeit autorisieren.
Auf internationaler Ebene findet die Normungsarbeit in den technischen Komitees ISO/TC 135 “Non-destructive testing” und ISO/TC 44/SC 5 “Testing and inspection of welds” und ihren Arbeitsgruppen statt. Das europäische Pendant ist das CEN/TC 138 “Zerstörungsfreie Prüfverfahren” mit seinen Arbeitsgremien. Die DINSpiegelgremien sind für die deutsche Mitarbeit in diesen Gremien und die inhaltliche Bewertung der Norm-Entwürfe zuständig.
T2 - DGZfP Jahrestagung 2024
CY - Osnabrück, Germany
DA - 05.05.2024
KW - Normung
KW - Zerstörungsfreie Prüfung
KW - Qualifizierung
KW - Qualitätssicherung
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-600726
DO - https://doi.org/10.58286/29496
IS - 5
SP - 1
EP - 6
AN - OPUS4-60072
LA - deu
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Fischer, Janina
A1 - Kaufmann, Jan Ole
A1 - Weller, Michael G.
T1 - Simple Determination of Affinity Constants of Antibodies by Competitive Immunoassays
N2 - The affinity constant, also known as the equilibrium constant, binding constant, equilibrium association constant, or the reciprocal value, the equilibrium dissociation constant (Kd), can be considered as one of the most important characteristics for any antibody–antigen pair. Many methods based on different technologies have been proposed and used to determine this value. However, since a very large number of publications and commercial datasheets do not include this information, significant obstacles in performing such measurements seem to exist. In other cases where such data are reported, the results have often proved to be unreliable. This situation may indicate that most of the technologies available today require a high level of expertise and effort that does not seem to be available in many laboratories. In this paper, we present a simple approach based on standard immunoassay technology that is easy and quick to perform. It relies on the effect that the molar IC50 approaches the Kd value in the case of infinitely small concentrations of the reagents. A two-dimensional dilution of the reagents leads to an asymptotic convergence to Kd. The approach has some similarity to the well-known checkerboard titration used for the optimization of immunoassays. A well-known antibody against the FLAG peptide, clone M2, was used as a model system and the results were compared with other methods. This approach could be used in any case where a competitive assay is available or can be developed. The determination of an affinity constant should belong to the crucial parameters in any quality control of antibody-related products and assays and should be mandatory in papers using immunochemical protocols.
N2 - Die Affinitätskonstante, auch bekannt als Gleichgewichtskonstante, Bindungskonstante, Gleichgewichtsassoziationskonstante oder der reziproke Wert, die Gleichgewichtsdissoziationskonstante (Kd), kann als eine der wichtigsten Eigenschaften für jedes Antikörper-Antigen-Paar angesehen werden. Zur Bestimmung dieses Wertes wurden zahlreiche Methoden auf der Grundlage verschiedener Technologien vorgeschlagen und verwendet. Da jedoch eine sehr große Anzahl von Veröffentlichungen und kommerziellen Datenblätter diese Information nicht enthalten, scheint es erhebliche Hindernisse bei der Durchführung solcher Messungen zu geben. In anderen Fällen, in denen solche Daten angegeben werden, haben sich die Ergebnisse häufig als unzuverlässig erwiesen. Diese Situation könnte darauf hindeuten, dass die meisten der heute verfügbaren Technologien ein hohes Maß an Fachwissen und Aufwand erfordern, das in vielen Labors nicht vorhanden zu sein scheint. In diesem Beitrag stellen wir einen einfachen Ansatz vor, der auf der Standard-Immunoassay-Technologie basiert und einfach und schnell durchführbar ist. Er beruht auf dem Effekt, dass sich der molare IC50 bei unendlich kleinen Reagenz-Konzentrationen dem Kd-Wert annähert. Eine zweidimensionale Verdünnung der Reagenzien führt zu einer asymptotischen Konvergenz zu Kd. Der Ansatz hat eine gewisse Ähnlichkeit mit der bekannten Checkerboard-Titration, die zur Optimierung von Immunoassays verwendet wird. Ein bekannter Antikörper gegen das FLAG-Peptid, Klon M2, wurde als Modellsystem verwendet, und die Ergebnisse wurden mit anderen Methoden verglichen. Dieser Ansatz kann überall dort angewendet werden, wo ein kompetitiver Assay verfügbar ist oder entwickelt werden kann. Die Bestimmung einer Affinitätskonstante sollte zu den entscheidenden Parametern bei der Qualitätskontrolle von Antikörperprodukten und -assays gehören und in Arbeiten, die immunchemische Protokolle verwenden, obligatorisch sein.
KW - ELISA
KW - Competitive immunoassay
KW - IC50
KW - Test midpoint
KW - Point of inflection
KW - Equilibrium constant
KW - Dissociation constant
KW - Binding strength
KW - Antibody antigen complex
KW - Bio-interaction
KW - SPR
KW - Surface-plasmon resonance
KW - FLAG peptide
KW - Clone M2
KW - Antibody quality
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-605607
DO - https://doi.org/10.3390/mps7030049
SN - 2409-9279
VL - 7
IS - 3
SP - 1
EP - 11
PB - MDPI
CY - Basel
AN - OPUS4-60560
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Sunder, S.
A1 - Jauregui Rozo, Maria
A1 - Inasu, S.
A1 - Schartel, Bernhard
A1 - Ruckdäschel, H.
T1 - A systematic investigation of the transfer of polyphosphate/inorganic silicate flame retardants from epoxy resins to layered glass fiber-reinforced composites and their post-furnace flexural properties
N2 - The systematic transfer of solvent-free, additive flame retardant (FR) formulations from epoxy resins to glass fiber-reinforced epoxy composites (GFRECs) through prepregs is difficult. Additionally, obtaining data on their post-fire mechanics is often challenging. Utilizing melamine polyphosphate (MPP), ammonium polyphosphate (APP), and silane-coated ammonium polyphosphate (SiAPP) FRs with low-melting inorganic silicates (InSi) in an 8:2 proportion and 10% loading by weight in a diglycidyl ether of bisphenol A (DGEBA) resin, a systematic investigation of the processing properties, room-temperature mechanics, and temperature-based mechanics of the systems was performed. The resin was cured with a dicyandiamide hardener (DICY) and a urone accelerator. The results revealed no substantial impact of these FRs at the current loading on the resin's glass transition temperature or processability. However, the fire residues from cone calorimetry tests of the composites containing FRs were found to be only 15-20% of the thickness of the resins, implying a suppression of intumescence upon transfer. At room temperature, the decrease in the flexural modulus for the composites containing FRs was negligible. Exposure of the composites in a furnace at 400°C as a preliminary study before ignition tests was shown to cause significant flexural moduli reductions after 2.5 min of exposure and complete delamination after 3 min making further testing unviable. This study emphasizes the need for future research on recovering modes of action upon transfer of FR formulations from resins to composites. Based on the challenges outlined in this investigation, sample adaptation methods for post-fire analysis will be developed in a future study.
KW - DGEBA
KW - Prepregs
KW - Glass fiber-reinforced composites
KW - Post-fire testing
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-605239
DO - https://doi.org/10.1002/pc.28416
SN - 1548-0569
SN - 0272-8397
VL - 45
IS - 10
SP - 9389
EP - 9406
PB - Wiley
AN - OPUS4-60523
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Simon, Franz-Georg
A1 - Scholz, Philipp
T1 - Sequential Extraction of Incineration Bottom Ash: Conclusions Regarding Ecotoxicity
N2 - The classification of incineration bottom ash (IBA) as hazardous or non-hazardous according to ecotoxic hazard property HP14 is still under debate. In this context, only the compounds of Zn and Cu with the hazard statement code H410 are of relevance. With an approach based on the grouping of substances, it was shown that such substances are either readily water-soluble or slightly and sparingly soluble. The concentrations of readily soluble Cu and Zn compounds in IBA are far below the cut-off value of 0.1%. Slightly and sparingly soluble Zn and Cu compounds could be quantified in the first fraction of a four-step sequential extraction procedure. With the results from the complete sequence, the dimensionless synthesis toxicity index (STI) was calculated and was in the range of 494 to 1218 for the four investigated IBA samples. It was concluded that IBA can usually be classified as non-hazardous.
KW - Incineration bottom ash
KW - Hazard properties
KW - Ecotoxicity
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-605262
DO - https://doi.org/10.3390/app14135541
SN - 2076-3417
VL - 14
IS - 13
SP - 1
EP - 12
PB - MDPI
CY - Basel
AN - OPUS4-60526
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Rockel, Daniel
A1 - Sanchez Olivares, G.
A1 - Schartel, Bernhard
T1 - Improving the Flame Retardancy of Aluminium Trihydroxide in Thermoplastic Starch Biocomposites Using Waste Fibers and Silicon-Based Synergists
N2 - The synergistic behavior of different silicon compounds is investigated in flame retardant biocomposites with aluminum trihydroxide (ATH) as the main flame retardant. The paper shows a new approach towards sustainable biocomposites through the implementation of thermoplastic starch (TPS), leather fibers from industrial waste streams, and non-hazardous flame retardants and synergists. In these multicomponent systems, the different components address different modes of action in the fire scenario. When ATH is partially substituted by glass frits or layered silicates, fire performance is enhanced without changing the total amount of filler in the polymer. In a biocomposite with 25 phr of fiber and 90 phr of ATH, substituting 5 phr of ATH for layered silicates increased the LOI from 31.5 vol % to 34.8 vol %, decreased the peak of heat release by 20%, and increased the UL 94 rating from V-1 to V-0.
KW - Biocomposites
KW - Sustainability
KW - Waste streams
KW - Flame retardancy
KW - Synergism
KW - Modes of action
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-605711
DO - https://doi.org/10.1021/acssusresmgt.4c00053
SN - 2837-1445
VL - 1
IS - 6
SP - 1131
EP - 1145
PB - ACS
AN - OPUS4-60571
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Scales, B. S.
A1 - Hasenrück, C.
A1 - Moldaenke, L.
A1 - Hassa, J.
A1 - Rückert-Reed, C.
A1 - Rummel, C.
A1 - Völkner, C.
A1 - Rynek, R.
A1 - Busche, T.
A1 - Kalinowski, J.
A1 - Jahnke, A.
A1 - Schmitt-Jansen, M.
A1 - Wendt-Potthoff, K.
A1 - Oberbeckmann, Sonja
T1 - Hunting for pigments in bacterial settlers of the Great Pacific Garbage Patch
N2 - The Great Pacific Garbage Patch, a significant collection of plastic introduced by human activities, provides an ideal environment to study bacterial lifestyles on plastic substrates. We proposed that bacteria colonizing the floating plastic debris would develop strategies to deal with the ultravioletexposed substrate, such as the production of antioxidant pigments. We observed a variety of pigmentation in 67 strains that were directly cultivated from plastic pieces sampled from the Garbage Patch. The genomic analysis of four representative strains, each distinct in taxonomy, revealed multiple pathways for carotenoid production. These pathways include those that produce
less common carotenoids and a cluster of photosynthetic genes. This
cluster appears to originate from a potentially new species of the Rhodobacteraceae family. This represents the first report of an aerobic anoxygenic photoheterotrophic bacterium from plastic biofilms. Spectral analysis showed that the bacteria actively produce carotenoids, such as betacarotene and beta-cryptoxanthin, and bacteriochlorophyll a. Furthermore, we discovered that the genetic ability to synthesize carotenoids is more common in plastic biofilms than in the surrounding water communities. Our findings suggest that plastic biofilms could be an overlooked source of bacteria-produced carotenoids, including rare forms. It also suggests that photoreactive molecules might play a crucial role in bacterial biofilm communities in surface water.
KW - Microplastics
KW - Biofilm
KW - Pigment
KW - Microorganisms
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-605725
DO - https://doi.org/10.1111/1462-2920.16639
SN - 1462-2912
VL - 26
IS - 6
SP - e16639
PB - John Wiley & Sons Ltd.
AN - OPUS4-60572
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Baláž, Matej
A1 - Birinci, Mustafa
A1 - Şentürk, Kader
A1 - Achimovičová, Marcela
A1 - Baláž, Peter
A1 - Tampubolon, Imelda Octa
A1 - Stolar, Tomislav
A1 - Bienert, Ralf
A1 - Emmerling, Franziska
A1 - Erdemoğlu, Sema
A1 - Sis, Hikmet
A1 - Erdemoğlu, Murat
T1 - Utilizing Taguchi method and in situ X-ray powder diffraction monitoring to determine the influence of mechanical activation conditions on the physico-chemical properties and Al leachability of K-feldspar
N2 - K-feldspar represents an important natural resource of potassium and aluminum. Within the framework of this study, the K-feldspar was mechanically activated in a planetary ball mill under different conditions planned according to 43 Taguchi orthogonal array experimental design. As outputs, specific surface area (SBET), median particle size (d50), amorphization degree of mineral phases , and Al recovery were used. It was found that the initial d50 value of 293 μm could be reduced to 6.7 μm and the SBET value of 4.7 m2/g could be increased up to 32.5 m2/g upon milling. Both microcline KAl3SiO8, and albite NaAl3SiO8 could be almost completely amorphized, whereas quartz SiO2 still maintained some crystallinity even under the most intensive conditions. Increasing SBET and decreasing the d50 values did not lead to a significant improvement in Al leach recovery, whereas a clear relationship between the amorphization of microcline and the recovered aluminum was found. Analysis of Variance (ANOVA) showed that increasing ball-to-powder ratio is the most beneficial for the improvement in Al recovery. In situ powder X-ray diffraction monitoring performed in an oscillation ball mill under synchrotron irradiation has shown very rapid amorphization of microcline phase at the beginning. However, amorphization of microcline was only partial after two hours of the treatment in this mill, apart from almost complete process in the planetary ball mill. In the end, regressions for the calculation of Al recovery by knowing the values of input parameters were calculated. In general, by just using mechanical activation without the subsequent roasting process that is commonly used to boost metal recoveries, it was possible to quantitatively recover aluminum from K-feldspar.
KW - Mechanochemistry
KW - Mechanical activation
KW - Design of experiments
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-611059
DO - https://doi.org/10.1016/j.jmrt.2024.08.156
SN - 2238-7854
VL - 32
SP - 3886
EP - 3895
PB - Elsevier B.V.
AN - OPUS4-61105
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Bacurau, V. P.
A1 - Moreira, P. A. F. P.
A1 - Bertoli, G.
A1 - Andreoli, A. F.
A1 - Mazzer, E.
A1 - de Assis, F. F.
A1 - Gargarella, P.
A1 - Koga, G.
A1 - Stumpf, G. C.
A1 - Figueroa, S. J. A.
A1 - Widom, M.
A1 - Kaufman, M.
A1 - Fantin, Andrea
A1 - Cao, Y.
A1 - Freitas, R.
A1 - Miracle, D.
A1 - Coury, F. G.
T1 - Comprehensive analysis of ordering in CoCrNi and CrNi2 alloys
N2 - Chemical Short-Range Order (CSRO) has attracted recent attention from many researchers, creating intense debates about its impact on material properties.
The challenges lie in confirming and quantifying CSRO, as its detection proves exceptionally demanding, contributing to conflicting data in the literature regarding its true effects on mechanical properties. Our work uses highprecision calorimetric data to unambiguously prove the existence and, coupled with atomistic simulations, quantify the type of CSRO. This methodology allows us to propose a mechanism for its formation and destruction based on the heat evolution during thermal analysis and facilitates a precise identification of local ordering in CoCrNi alloys. Samples of CoCrNi (Co33Cr33Ni33) and CrNi2 (Cr33Ni66) alloys are fabricated in varying ordered states, extensively characterized via synchrotron X-ray diffraction, X-ray absorption spectroscopy, and transmission electron microscopy. Samples with considerably different ordered states are submitted to tensile tests with in-situ synchrotron X-ray diffraction. We demonstrate, despite inducing varied CSRO levels in CoCrNi, no significant alterations in overall mechanical behavior emerge.
However, the CrNi2 alloy, which undergoes long-range ordering, experiences significant shifts in yield strength, ultimate tensile stress and ductility.
KW - Mechanical properties
KW - Short-range ordering
KW - Calorimetry
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-611075
DO - https://doi.org/10.1038/s41467-024-52018-w
VL - 15
IS - 1
SP - 1
EP - 11
PB - Springer Science and Business Media LLC
AN - OPUS4-61107
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Simon, Fabian
A1 - von der Au, Marcus
A1 - Gehrenkemper, Lennart
A1 - Meermann, Björn
T1 - An optimized method for PFAS analysis using HR–CS–GFMAS via GaF detection
N2 - The analysis of per- and polyfluoroalkyl substances (PFAS) via sum parameters like extractable organic fluorine (EOF) in combination with high resolution-continuum source-graphite furnace molecular absorption spectrometry (HR–CS–GFMAS) is highly promising regarding fluorine sensitivity and selectivity. However, the HR–CS–GFMAS method includes several drying and heating steps which can lead to losses of volatile PFAS before the molecular formation step using e.g., GaF formation. Hence, the method leads to a strong discrimination of PFAS within the EOF depending on their physical/chemical properties and is therefore associated with reduced accuracy. To reduce this discrepancy and to indicate realistic PFAS pollution values, an optimization of the HR–CS–GFMAS method for PFAS analysis is needed. Hence, we determined fluorine response factors of several PFAS with different physical/chemical properties upon application of systematic optimization steps. We could therefore improve the method's sensitivity for PFAS analysis using a modifier drying pre-treatment step followed by a sequential injection of sample solutions. The highest improvement in sensitivity of volatile PFAS was shown upon addition of a Mg modifier during drying pre-treatment. Thereby, during optimization the relative standard deviation of fluorine response factors could be reduced from 55 % (initial method) to 27 % (optimized method) leading to a more accurate determination of organofluorine sum parameters. The method provides an instrumental LOD and LOQ of β(F) 1.71 μg/L and 5.13 μg/L, respectively. Further validation aimed to investigate several matrix effects with respect to water matrices. Here, substance-specific behavior was observed. For example, perfluorooctanoic acid (PFOA) which was used as calibrator, showed signal suppressions upon high chloride concentrations (>50 mg/L). Hence, a thorough separation of Cl from analytes during sample preparation is needed for accurate sum parameter analysis.
KW - PFAS
KW - GF-AAS
KW - Method optimization
PY - 2025
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-610522
DO - https://doi.org/10.1016/j.talanta.2024.126811
VL - 281
SP - 1
EP - 11
PB - Elsevier B.V.
AN - OPUS4-61052
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Chronakis, Michail Ioannis
A1 - Meermann, Björn
A1 - von der Au, Marcus
T1 - The evolution of data treatment tools in single-particle and single-cell ICP-MS analytics
N2 - Single-particle inductively coupled plasma-mass spectrometry (sp-ICP-MS) is one of the most powerful tools in the thriving field of nanomaterial analysis. Along the same lines, single-cell ICP-MS (sc-ICP-MS) has become an invaluable tool in the study of the variances of cell populations down to a per-cell basis. Their importance and application fields have been listed numerous times, across various reports and reviews. However, not enough attention has been paid to the immense and ongoing development of the tools that are currently available to the analytical community for the acquisition, and more importantly, the treatment of single-particle and single-cell-related data. Due to the ever-increasing demands of modern research, the efficient and dependable treatment of the data has become more important than ever. In addition, the field of single-particle and single-cell analysis suffers due to a large number of approaches for the generated data—with varying levels of specificity and applicability. As a result, finding the appropriate tool or approach, or even comparing results, can be challenging. This article will attempt to bridge these gaps, by covering the evolution and current state of the tools at the disposal of sp-ICP-MS users.
Graphical Abstract
KW - Trend Article
KW - spICP-MS
KW - Data Tools
KW - scICP-MS
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-610539
DO - https://doi.org/10.1007/s00216-024-05513-4
SP - 1
EP - 7
PB - Springer Science and Business Media LLC
AN - OPUS4-61053
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Mangarova, Dilyana Branimirova
A1 - Reimann, Carolin
A1 - Kaufmann, Jan Ole
A1 - Möckel, Jana
A1 - Kader, Avan
A1 - Adams, Lisa Christine
A1 - Ludwig, Antje
A1 - Onthank, David
A1 - Robinson, Simon
A1 - Karst, Uwe
A1 - Helmer, Rebecca
A1 - Botnar, Rene
A1 - Hamm, Bernd
A1 - Makowski, Marcus Richard
A1 - Brangsch, Julia
T1 - Elastin-specific MR probe for visualization and evaluation of an interleukin-1β targeted therapy for atherosclerosis
N2 - Atherosclerosis is a chronic inflammatory condition of the arteries and represents the primary cause of various cardiovascular diseases. Despite ongoing progress, finding effective anti-inflammatory therapeutic strategies for atherosclerosis remains a challenge. Here, we assessed the potential of molecular magnetic resonance imaging (MRI) to visualize the effects of 01BSUR, an anti-interleukin-1β monoclonal antibody, for treating atherosclerosis in a murine model. Male apolipoprotein E-deficient mice were divided into a therapy group (01BSUR, 2 × 0.3 mg/kg subcutaneously, n = 10) and control group (no treatment, n = 10) and received a high-fat diet for eight weeks. The plaque burden was assessed using an elastin-targeted gadolinium-based contrast probe (0.2 mmol/kg intravenously) on a 3 T MRI scanner. T1-weighted imaging showed a significantly lower contrast-to-noise (CNR) ratio in the 01BSUR group (pre: 3.93042664; post: 8.4007067) compared to the control group (pre: 3.70679168; post: 13.2982156) following administration of the elastin-specific MRI probe (p < 0.05). Histological examinations demonstrated a significant reduction in plaque size (p < 0.05) and a significant decrease in plaque elastin content (p < 0.05) in the treatment group compared to control animals. This study demonstrated that 01BSUR hinders the progression of atherosclerosis in a mouse model. Using an elastin-targeted MRI probe, we could quantify these therapeutic effects in MRI.
N2 - Atherosklerose ist eine chronische entzündliche Erkrankung der Arterien und die Hauptursache für verschiedene Herz-Kreislauf-Erkrankungen. Trotz kontinuierlicher Fortschritte ist es nach wie vor schwierig, wirksame entzündungshemmende Therapiestrategien für Atherosklerose zu finden. In dieser Studie haben wir das Potenzial der molekularen Magnetresonanztomographie (MRT) zur Visualisierung der Wirkung von 01BSUR, einem monoklonalen Anti-Interleukin-1β-Antikörper, zur Behandlung von Atherosklerose in einem Mausmodell untersucht. Männliche Apolipoprotein-E-defiziente Mäuse wurden in eine Therapiegruppe (01BSUR, 2 × 0,3 mg/kg subkutan, n = 10) und eine Kontrollgruppe (keine Behandlung, n = 10) aufgeteilt und erhielten acht Wochen lang eine fettreiche Diät. Die Plaquebelastung wurde mit einer auf Elastin ausgerichteten Kontrastmittelsonde auf Gadoliniumbasis (0,2 mmol/kg intravenös) auf einem 3-T-MRT-Scanner untersucht. Die T1-gewichtete Bildgebung zeigte ein signifikant niedrigeres Kontrast-Rausch-Verhältnis (CNR) in der 01BSUR-Gruppe (vorher: 3,93042664; nachher: 8,4007067) im Vergleich zur Kontrollgruppe (vorher: 3,70679168; nachher: 13,2982156) nach Verabreichung der Elastin-spezifischen MRT-Sonde (p < 0,05). Histologische Untersuchungen zeigten eine signifikante Verringerung der Plaque-Größe (p < 0,05) und eine signifikante Abnahme des Plaque-Elastin-Gehalts (p < 0,05) in der Behandlungsgruppe im Vergleich zu den Kontrolltieren. Diese Studie zeigte, dass 01BSUR das Fortschreiten der Atherosklerose in einem Mausmodell hemmt. Mit einer auf Elastin ausgerichteten MRT-Sonde konnten wir diese therapeutischen Effekte in der MRT quantifizieren.
KW - Atherosclerosis
KW - Molecular imaging
KW - Elastin
KW - Plaque
KW - Interleukin-1beta
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-610858
DO - https://doi.org/10.1038/s41598-024-71716-5
VL - 14
IS - 1
SP - 1
EP - 11
PB - Springer Science and Business Media LLC
AN - OPUS4-61085
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Sunder, S.
A1 - Jauregui Rozo, Maria
A1 - Inasu, S.
A1 - Schartel, Bernhard
A1 - Ruckdäschel, H.
T1 - Investigating the changing dynamics of processing, temperature-based mechanics, and flame retardancy in the transfer of ammonium polyphosphate/inorganic silicate flame retardants from epoxy resins to glass fiber composites
N2 - Although numerous investigations study the improvement of flame retardancy of epoxy resins using additives, maintaining the flame retardant (FRs) modes of action present in the resins upon transfer to composites is challenging. In this study, ammonium polyphosphate (APP) and inorganic silicate (InSi) are loaded at 10%, 30%, and 50% by weight, in a diglycidyl ether of bisphenol A (DGEBA) resin cured with dicyandiamide and transferred to bidirectional (BD) glass fiber (GF) composites. Although a 50% loading of the FRs impacts the curing kinetics of the resin system, the effect on the glass transition temperature of the resin system remains negligible compared to reactive FRs in the state of the art integrated into the resin's chemical structure. Increasing the FR content improved the heat release characteristics in both the resins and composites. However, the charring mode of action is completely suppressed in the formulation with 10% APP + InSi. A 30% concentration of the FRs restored the charring action in the composite and the GFs provide increased protective layer action upon transfer to the composites. This study highlights the importance of accounting for the changing dynamics related to processing and flame retardancy upon transferring FRs from resins to composites.
KW - Composites
KW - Flame retardance
KW - Resins
KW - Synthesis and processing techniques
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-610484
DO - https://doi.org/10.1002/app.55988
SN - 1097-4628
VL - 141
IS - 39
SP - 1
EP - 18
PB - Wiley
CY - New York, NY
AN - OPUS4-61048
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Golian, M. J.
A1 - Friedman, D. A.
A1 - Harrison, M.
A1 - McMahon, Dino Peter
A1 - Buellesbach, J.
T1 - Chemical and transcriptomic diversity do not correlate with ascending levels of social complexity in the insect order Blattodea
N2 - AbstractEusocial insects, such as ants and termites, are characterized by high levels of coordinated social organization. This is contrasted by solitary insects that display more limited forms of collective behavior. It has been hypothesized that this gradient in sociobehavioral sophistication is positively correlated with chemical profile complexity, due to a potentially increased demand for diversity in chemical communication mechanisms in insects with higher levels of social complexity. However, this claim has rarely been assessed empirically. Here, we compare different levels of chemical and transcriptomic complexity in selected species of the order Blattodea that represent different levels of social organization, from solitary to eusocial. We primarily focus on cuticular hydrocarbon (CHC) complexity, since it has repeatedly been demonstrated that CHCs are key signaling molecules conveying a wide variety of chemical information in solitary as well as eusocial insects. We assessed CHC complexity and divergence between our studied taxa of different social complexity levels as well as the differentiation of their respective repertoires of CHC biosynthesis gene transcripts. Surprisingly, we did not find any consistent pattern of chemical complexity correlating with social complexity, nor did the overall chemical divergence or transcriptomic repertoire of CHC biosynthesis genes reflect on the levels of social organization. Our results challenge the assumption that increasing social complexity is generally reflected in more complex chemical profiles and point toward the need for a more cautious and differentiated view on correlating complexity on a chemical, genetic, and social level.
KW - Chemical ecology
KW - Ecological genetics
KW - Entomology
KW - Evolutionary ecology
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-608260
DO - https://doi.org/10.1002/ece3.70063
SN - 2045-7758
VL - 14
IS - 8
SP - 1
EP - 13
PB - Wiley
AN - OPUS4-60826
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Hellemans, S.
A1 - Rocha, M. M.
A1 - Wang, M.
A1 - Romero Arias, J.
A1 - Aanen, D. K.
A1 - Bagnères, A.-G.
A1 - Buček, A.
A1 - Carrijo, T. F.
A1 - Chouvenc, T.
A1 - Cuezzo, C.
A1 - Constantini, J. P.
A1 - Constantino, R.
A1 - Dedeine, F.
A1 - Deligne, J.
A1 - Eggleton, P.
A1 - Evans, T. A.
A1 - Hanus, R.
A1 - Harrison, Mark C.
A1 - Harry, M.
A1 - Josens, G.
A1 - Jouault, C.
A1 - Kalleshwaraswamy, C. M.
A1 - Kaymak, E.
A1 - Korb, J.
A1 - Lee, C.-Y.
A1 - Legendre, F.
A1 - Li, H.-F.
A1 - Lo, N.
A1 - Lu, T.
A1 - Matsuura, K.
A1 - Maekawa, K.
A1 - McMahon, Dino Peter
A1 - Mizumoto, N.
A1 - Oliveira, D. E.
A1 - Poulsen, M.
A1 - Sillam-Dussès, D.
A1 - Su, N.-Y.
A1 - Tokuda, G.
A1 - Vargo, E. L.
A1 - Ware, J. L.
A1 - Šobotník, J.
A1 - Scheffrahn, R. H.
A1 - Cancello, E.
A1 - Roisin, Y.
A1 - Engel, M. S.
A1 - Bourguignon, T.
T1 - Genomic data provide insights into the classification of extant termites
N2 - The higher classification of termites requires substantial revision as the Neoisoptera, the most diverse termite lineage, comprise many paraphyletic and polyphyletic higher taxa. Here, we produce an updated termite classification using genomic-scale analyses. We reconstruct phylogenies under diverse substitution models with ultraconserved elements analyzed as concatenated matrices or within the multi-species coalescence framework. Our classification is further supported by analyses controlling for rogue loci and taxa, and topological tests. We show that the Neoisoptera are composed of seven family-level monophyletic lineages, including the Heterotermitidae Froggatt, Psammotermitidae Holmgren, and Termitogetonidae Holmgren, raised from subfamilial rank. The species-rich Termitidae are composed of 18 subfamily-level monophyletic lineages, including the new subfamilies Crepititermitinae, Cylindrotermitinae, Forficulitermitinae, Neocapritermitinae, Protohamitermitinae, and Promirotermitinae; and the revived Amitermitinae Kemner, Microcerotermitinae Holmgren, and Mirocapritermitinae Kemner. Building an updated taxonomic classification on the foundation of unambiguously supported monophyletic lineages makes it highly resilient to potential destabilization caused by the future availability of novel phylogenetic markers and methods. The taxonomic stability is further guaranteed by the modularity of the new termite classification, designed to accommodate as-yet undescribed species with uncertain affinities to the herein delimited monophyletic lineages in the form of new families or subfamilies.
KW - Termite
KW - Taxonomy
KW - Evolution
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-608276
DO - https://doi.org/10.1038/s41467-024-51028-y
VL - 15
IS - 1
SP - 1
EP - 17
PB - Springer Science and Business Media LLC
AN - OPUS4-60827
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - El Moutaouakil, H.
A1 - Fuchs, C.
A1 - Savli, E.
A1 - Heimann, Jan
A1 - Prager, Jens
A1 - Moll, J.
A1 - Tschöke, K.
A1 - Márquez Reyes, O.
A1 - Schackmann, O.
A1 - Memmolo, V.
A1 - Schneider, T.
T1 - Acquiring a Machine Learning Data Set for Structural Health Monitoring of Hydrogen Pressure Vessels at Operating Conditions using Guided Ultrasonic Waves
N2 - Hydrogen is an energy source of increasing importance. As hydrogen is very reactive to air and needs to be stored under high pressure, it is crucial to provide safe transportation and storage. Therefore, structural health monitoring, based on guided ultrasonic waves and machine learning methods, is used for Composite Overwrapped Pressure Vessels (COPVs) containing hydrogen. To acquire data that allows robust detection of COPV defects, there are two main process parameters to consider. These are the pressurization of the vessel and the temperature conditions at the vessel. This paper will focus on the derivation of a design of experiment (DoE) from the needs of various validation scenarios (e.g. concerning pressure, temperature or excitation frequency). Practical limitations must be considered as well. We designed experiments with multiple reversible damages at different positions. A network of 25 transducers, structured as five rings with five sensors in one line, is installed on a vessel. Guided ultrasonic waves are used via the pitch-catch procedure, which means that the transducers act pairwise as transmitter and receiver in order to measure all transmitterreceiver combinations. This leads to 600 signal paths, recorded by a Verasonics Vantage 64 LF data acquisition system. Finally, the influences of temperature and pressure within the acquired data set are going to be visualized.
T2 - 11th European Workshop on Structural Health Monitoring
CY - Potsdam, Germany
DA - 10.06.2024
KW - Composite Overwrapped Pressure Vessel
KW - Hydrogen
KW - Guided Ultrasonic Waves
KW - Data Acquisition
KW - Pressurization
KW - Machine Learning
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-607472
DO - https://doi.org/10.58286/29754
SN - 1435-4934
SP - 1
EP - 8
AN - OPUS4-60747
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Kadri, Lena
A1 - Casali, Lucia
A1 - Emmerling, Franziska
A1 - Tajber, Lidia
T1 - Mechanochemical comparison of ball milling processes for levofloxacin amorphous polymeric systems
N2 - This study aimed to investigate the amorphization capabilities of levofloxacin hemihydrate (LVXh), a fluoroquinolone drug, using a polymer excipient, Eudragit® L100 (EL100). Ball milling (BMing) was chosen as the manufacturing process and multiple mill types were utilized for comparison purposes. The product outcomes of each mill were analyzed in detail. The solid-state of the samples produced was comprehensively characterized by Powder X-ray Diffraction (PXRD), In-situ PXRD, Differential Scanning Calorimetry (DSC), Solid-State Fourier Transform Infrared Spectroscopy (FT-IR), and Dynamic Vapor Sorption (DVS). The crystallographic planes of LVXh were investigated by in-situ PXRD to disclose the presence or absence of weak crystallographic plane(s). The mechanism of LVXh:EL100 system formation was discovered as a two-step process, first involving amorphization of LVXh followed by an interaction with EL100, rather than as an instantaneous process. DVS studies of LVXh:EL100 samples showed different stability properties depending on the mill used and % LVXh present. Overall, a more sustainable approach for achieving full amorphization of the fluoroquinolone drug, LVXh, was accomplished, and advancements to the fast-growing world of pharmaceutical mechano- and tribo-chemistry were made.
KW - Levofloxacin
KW - Eudragit® L100
KW - Mechanochemistry
KW - Phase transformation
KW - In situ monitoring
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-611129
DO - https://doi.org/10.1016/j.ijpharm.2024.124652
SN - 0378-5173
VL - 665
SP - 1
EP - 16
PB - Elsevier B.V.
AN - OPUS4-61112
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Schneider, Beate
A1 - Pfeiffer, Friedhelm
A1 - Remus, Daniela
A1 - Dyall-Smith, Mike
A1 - Kunte, Hans-Jörg
ED - Klepac-Ceraj, Vanja
T1 - Genome sequence of Pseudomonas silesiensis strain G3, a member of a bacterial consortium capable of polyethylene degradation
N2 - A consortium of landfill bacteria including strain G3 can break down polyethylene, a long-lasting plastic that accumulates in the environment. The complete genome sequence of strain G3 was determined by PacBio and Nanopore sequencing and consists of three circular replicons. Genome-based classification assigned strain G3 to the species Pseudomonas silesiensis.
KW - PE degradation
KW - Polyethylene
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-611618
DO - https://doi.org/10.1128/mra.00138-24
SN - 2576-098X
VL - 13
IS - 11
SP - 1
EP - 3
PB - American Society for Microbiology
AN - OPUS4-61161
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Jasiuniene, E.
A1 - Yilmaz, Bengisu
A1 - Smagulova, D.
A1 - Bhat, G. A.
A1 - Cicenas, V.
A1 - Zukauskas, E.
A1 - Mazeika, L.
T1 - Non-Destructive Evaluation of the Quality of Adhesive Joints Using Ultrasound, X-ray, and Feature-Based Data Fusion
N2 - The aim of this work is to achieve reliable nondestructive evaluation (NDE) of adhesively bonded aerospace components by developing novel multidimensional data fusion techniques, which would combine the information obtained by ultrasonic and X-ray NDE methods. Separately, both NDE techniques have their advantages and limitations. The integration of data obtained from pulse echo immersion ultrasound testing and radiography holds immense potential to help improve the reliability of non-destructive evaluation. In this study, distinctive features obtained from single techniques, traditional ultrasonic pulse echo testing, and radiography, as well as fused images, were investigated and the suitability of these distinctive features and fusion techniques for improving the probability of defect detection was evaluated. For this purpose, aluminum single lap joints with brass inclusions were analyzed using ultrasound pulse echo and radiography techniques. The distinctive features were extracted from the data obtained, and images of features obtained by both techniques were fused together. Different combinations of features and fusion algorithms were investigated, considering the desire to automate data evaluation in the future.
KW - Data fusion
KW - Ultrasonics
KW - Radiography
PY - 2022
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-565789
DO - https://doi.org/10.3390/app122412930
VL - 12
IS - 24
SP - 1
EP - 20
PB - MDPI
AN - OPUS4-56578
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Dariz, P.
A1 - Schmid, Thomas
T1 - Raman focal point on Roman Egyptian blue elucidates disordered cuprorivaite, green glass phase and trace compounds
N2 - The discussed comparative analyses of Roman Imperial pigment balls and fragmentary murals unearthed in the ancient cities of Aventicum and Augusta Raurica (Switzerland) by means of Raman microspectroscopy pertain to a predecessor study on trace compounds in Early Medieval Egyptian blue (St. Peter, Gratsch, South Tyrol, Northern Italy). The plethora of newly detected associated minerals of the raw materials surviving the synthesis procedure validate the use of quartz sand matching the composition of sediments transported by the Volturno river into the Gulf of Gaeta (Campania, Southern Italy) with a roasted sulphidic copper ore and a mixed-alkaline plant ash as fluxing agent. Thus, the results corroborate a monopolised pigment production site located in the northern Phlegrean Fields persisting over the first centuries A.D., this in line with statements of the antique Roman writers Vitruvius and Pliny the Elder and recent archaeological evidences. Beyond that, Raman spectra reveal through gradual peak shifts and changes of band width locally divergent process conditions and compositional inhomogeneities provoking crystal lattice disorder in the chromophoric cuprorivaite as well as the formation of a copper-bearing green glass phase, the latter probably in dependency of the concentration of alkali flux, notwithstanding that otherwise solid-state reactions predominate the synthesis.
KW - Raman microspectroscopy
KW - Egyptian blue
KW - Cuprorivaite
PY - 2022
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-559028
DO - https://doi.org/10.1038/s41598-022-19923-w
SN - 2045-2322
VL - 12
IS - 1
SP - 1
EP - 12
PB - Nature Publishing Group
CY - London
AN - OPUS4-55902
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Sechi, R.
A1 - Fackeldey, K.
A1 - Chewle, Surahit
A1 - Weber, M.
T1 - SepFree NMF: A toolbox for analyzing the kinetics of sequential spectroscopic data
N2 - This work addresses the problem of determining the number of components from sequential spectroscopic data analyzed by non-negative matrix factorization without separability assumption (SepFree NMF). These data are stored in a matrix M of dimension “measured times” versus “measured wavenumbers” and can be decomposed to obtain the spectral fingerprints of the states and their evolution over time. SepFree NMF assumes a memoryless (Markovian) process to underline the dynamics and decomposes M so that M = WH, with W representing the components’ fingerprints and H their kinetics. However, the rank of this decomposition (i.e., the number of physical states in the process) has to be guessed from pre-existing knowledge on the observed process. We propose a measure for determining the number of components with the computation of the minimal memory effect resulting from the decomposition; by quantifying how much the obtained factorization is deviating from the Markovian property, we are able to score factorizations of a different number of components. In this way, we estimate the number of different entities which contribute to the observed system, and we can extract kinetic information without knowing the characteristic spectra of the single components. This manuscript provides the mathematical background as well as an analysis of computer generated and experimental sequentially measured Raman spectra.
KW - Kinetics from experiments
KW - Separability assumption
KW - Sequential spectroscopic data
PY - 2022
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-559046
DO - https://doi.org/10.3390/a15090297
SN - 1999-4893
VL - 15
IS - 9
SP - 1
EP - 16
PB - MDPI
CY - Basel
AN - OPUS4-55904
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Fackeldey, K.
A1 - Röhm, J.
A1 - Niknejad, A.
A1 - Chewle, Surahit
A1 - Weber, M.
T1 - Analyzing Raman spectral data without separabiliy assumption
N2 - Raman spectroscopy is a well established tool for the analysis of vibration spectra, which then allow for the determination of individual substances in a chemical sample, or for their phase transitions. In the time-resolved-Raman-sprectroscopy the vibration spectra of a chemical sample are recorded sequentially over a time interval, such that conclusions for intermediate products (transients) can be drawn within a chemical process. The observed data-matrix M from a Raman spectroscopy can be regarded as a matrix product of two unknown matrices W and H, where the first is representing the contribution of the spectra and the latter represents the chemical spectra. One approach for obtaining W and H is the non-negative matrix factorization. We propose a novel approach, which does not need the commonly used separability assumption. The performance of this approach is shown on a real world chemical example.
KW - Non-negative matrix factorization
KW - NMF
KW - Raman spectra
KW - Separability condition
KW - PCCA+
PY - 2021
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-559051
DO - https://doi.org/10.1007/s10910-020-01201-7
SN - 1572-8897
VL - 59
SP - 575
EP - 596
PB - Springer Science + Business Media
CY - Dordrecht
AN - OPUS4-55905
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Schoknecht, Ute
A1 - Mathies, H.
T1 - The Impact of Weather Conditions on Biocides in Paints
N2 - Weather conditions affect biocides on exposed outer surfaces on constructions. Contact with water causes hydrolysis and leaching of substances. Ultraviolet radiation may induce photolysis. As a result, a mixture of biocidal active substances and transformation products can be emitted into the environment. In a semi-field study, leaching of the biocidal active substances terbutryn, diuron, octylisothiazolinone, carbendazim, and selected transformation products was observed for two paints containing either a white or a red pigment. Painted test panels were exposed to natural weathering for about 1.5 years. Runoff samples were analyzed during the course of the experiment.
At the end of the study, residues of biocidal active substances and transformation products were determined in sections of the test panels. Emissions of substances were mainly observed during the first few months of the experiments. Increased emissions of transformation products were observed during periods of increased global radiation and subsequent periods with relatively high amounts of driving rain. Different patterns of transformation products were observed, especially for terbutryn, both for paints containing different pigments and in experiments that were started in different periods of the year, as well as during different periods of the experiments.
KW - Substance release
KW - Construction products
KW - Biocides
KW - Transformation
KW - Weathering
KW - Driving rain
KW - Global radiation
PY - 2022
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-560651
DO - https://doi.org/10.3390/ma15207368
VL - 15
IS - 20
SP - 1
EP - 16
PB - MDPI
CY - Basel
AN - OPUS4-56065
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Costabel, S.
A1 - Hiller, Thomas
A1 - Dlugosch, R.
A1 - Kruschwitz, Sabine
A1 - Müller Petke, M.
T1 - Evaluation of single-sided nuclear magnetic resonance technology for usage in geosciences
N2 - Because of its mobility and ability to investigate exposed surfaces, single-sided (SiS) nuclear magnetic resonance (NMR) technology enables new application fields in geosciences. To test and assess its corresponding potential, we compare longitudinal (T1) and transverse (T2) data measured by SiS NMR with those of conventional geoscientific laboratory NMR. We use reference sandstone samples covering a broad range of pore sizes. Our study demonstrates that the lower signal-to-noise ratio of SiS NMR data generally tends to slightly overestimated widths of relaxation time distributions and consequently pore size distributions. While SiS and conventional NMR produce very similar T1 relaxation data, unbiased SiS NMR results for T2 measurements can only be expected for fine material, i.e. clayey or silty sediments and soils with main relaxation times below 0.05s. This limit is given by the diffusion relaxation rate due to the gradient in the primary magnetic field associated with the SiS NMR. Above that limit, i.e. for coarse material, the relaxation data is strongly attenuated. If considering the diffusion relaxation time of 0.2 s in the numerical data inversion process, the information content >0.2s is blurred over a range larger than that of conventional NMR. However, our results show that principle range and magnitudes of the relaxation time distributions are reconstructed to some extent. Regarding these findings, SiS NMR can be helpful to solve geoscientific issues, e.g. to assess the hydro-mechanical properties of the walls of underground facilities or to provide local soil moisture data sets for calibrating indirect remote techniques on the regional scale. The greatest opportunity provided by the SiS NMR technology is the acquisition of profile relaxation data for rocks with significant bedding structures at the µm scale. With this unique feature, SiS NMR can support the understanding and modeling of hydraulic and diffusional anisotropy behavior of sedimentary rocks.
KW - Single-sided NMR
KW - Geosciences
KW - Nuclear magnetic resonance
PY - 2022
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-561676
DO - https://doi.org/10.1088/1361-6501/ac9800
SN - 0957-0233
VL - 34
IS - 1
SP - 1
EP - 13
PB - IOP Publishing
AN - OPUS4-56167
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Ermilova, Elena
A1 - Weise, Matthias
A1 - Hertwig, Andreas
T1 - Hybrid optical measurement technique for detection of defects in epitaxially grown 4H-SiC layers
N2 - Recent developments in power electronics require the use of new wide bandgap compound semiconductor. We demonstrate the use of the ellipsometry and white light interference microscopy to detect defects in epitaxially grown SiC layers on SiC substrates. Such hybrid optical metrology methods can be used to better understand the mechanism of the development of the defects as well as their effects on the material´s optoelectronic properties.
T2 - EOS Annual Meeting (EOSAM 2022)
CY - Porto, Portugal
DA - 12.09.2022
KW - Imaging ellipsometry
KW - White light interference microscopy
KW - Wide bandgap compound semiconductor
KW - Epitaxially grown 4H-SiC layers
PY - 2022
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-561113
DO - https://doi.org/10.1051/epjconf/202226610001
VL - 266
SP - 1
EP - 2
AN - OPUS4-56111
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Shaheen, Sabahat
A1 - Hicke, Konstantin
T1 - Measurement of Geometric Phase using a φ-OTDR setup
N2 - Geometric phase showing sensitivity to changes in polarisation state and intensity of backscattered light is measured using a novel φ-OTDR setup based on coherent heterodyne detection. Principle is demonstrated using a polarisation scrambler inline a fiber-under-test.
T2 - Optical Fiber Sensors 2022
CY - Alexandria, Virginia, United States
DA - 29.08.2022
KW - Coherent Heterodyne
KW - Geometric Phase
KW - Distributed Fiber Optic Sensor
PY - 2022
SN - 978-1-957171-14-2
SP - W4.72
AN - OPUS4-56116
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Sieber, M. J.
A1 - Wilke, M.
A1 - Appelt, O.
A1 - Oelze, Marcus
A1 - Koch-Müller, M.
T1 - Melting relations of Ca–Mg carbonates and trace element signature of carbonate melts up to 9 GPa – A proxy for melting of carbonated mantle lithologies
N2 - The most profound consequences of the presence of Ca–Mg carbonates (CaCO3–MgCO3) in the Earth’s upper mantle may be to lower the melting temperatures of the mantle and control the melt composition.
Low-degree partial melting of a carbonate-bearing mantle produces CO2-rich, silica-poor melts compositionally imposed by the melting relations of carbonates. Thus, understanding the melting relations in the CaCO3–MgCO3 system facilitates the interpretation of natural carbonate-bearing silicate systems.
We report the melting relations of the CaCO3–MgCO3 system and the partition coefficient of trace elements between carbonates and carbonate melt from experiments at high pressure (6 and 9 GPa) and temperature (1300–1800 ◦C) using a rocking multi-anvil press. In the absence of water, Ca–Mg carbonates are stable along geothermal gradients typical of subducting slabs. Ca–Mg carbonates (∼ Mg0.1–0.9Ca0.9–0.1CO3) partially melt beneath mid-ocean ridges and in plume settings. Ca–Mg carbonates melt incongruently, forming periclase crystals and carbonate melt between 4 and 9 GPa. Furthermore, we show that the rare earth element (REE) signature of Group-I kimberlites, namely strong REE fractionation and depletion of heavy REE relative to the primitive mantle, is resembled by carbonate melt in equilibrium with Ca-bearing magnesite and periclase at 6 and 9 GPa. This suggests that the dolomite–magnesite join of the CaCO3–MgCO3 system might be useful to approximate the REE signature of carbonate-rich melts parental to kimberlites.
KW - High pressure experiments
KW - Laser Ablation
PY - 2022
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-561197
DO - https://doi.org/10.5194/ejm-34-411-2022
SN - 0935-1221
VL - 34
IS - 5
SP - 411
EP - 424
PB - Copernicus Publications
CY - Göttingen
AN - OPUS4-56119
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Ewert, U.
A1 - Jaenisch, Gerd-Rüdiger
A1 - Schumacher, David
A1 - Bircher, B.
A1 - Meli, F.
A1 - Deresch, A.
T1 - EMPIR-Projekt NanoXSpot: Neue Normentwürfe für die Brennfleckmessung an Röntgenröhren im Makro-, Mikro- und Nanometerbereich für Hersteller und Anwender
N2 - Im Rahmen des EMPIR-Projektes NanoXSpot (Nanometre X-ray Focal Spot Measurement) werden rückführbare Messverfahren zur Bestimmung der Brennfleckgröße und -form von Röntgenröhren im Bereich von 100 nm bis 10 mm entwickelt, welche die Grundlage für die Erarbeitung mehrerer Normentwürfe bilden. Diese werden 2022 parallel bei ISO TC 135 (NDT) SC 5 (RT) und CEN TC 138 (NDT) WG 1 (RT) eingereicht. Entsprechende Normen werden auch bei ASTM vorgestellt. Die Norm EN 12543-4 (Kantenmethode) wird umgeschrieben für die Messung von Brennflecken von 1 μm – 10 mm durch Auswertung von Loch- oder Scheibenaufnahmen. Der im Rahmen des NanoXSpot-Projektes neu entwickelte NxS-Testkörper ist geeignet für den Bereich von 1 μm – 100 μm. Von 100 μm bis 10 mm können ASTM-Lochtestkörper verwendet werden, die bereits bei ASTM E 1165 beschrieben sind. Neu ist die Anwendung eines CT-Algorithmus zur Rekonstruktion der Brennflecke, um Lochblenden-basierte Brennfleckkameras, insbesondere im Bereich unter 100 μm, zu ersetzen. Ein neuer Normteil, EN 12543-6, wurde entworfen, um die Brennfleckmessung im Bereich 100 nm – 20 μm mit hoher Genauigkeit zu ermöglichen.
Verschiedene Strichgruppen-Testkörper kommen hier zum Einsatz. Das sind die JIMAPrüfkörper, ein neuer Hochkontrast-Strichgruppentestkörper von YXLON (HiCo) und der neu entwickelte Testkörper NxS. Diese werden vorgestellt. Die Messprozedur für Röhrenhersteller wird auf einer numerischen Fit-Prozedur basieren, die über einen Ringversuch im Projekt validiert wurde. Beide Normen benötigen numerische Auswertealgorithmen zur korrekten Anwendung, die als kommerzielle Software und Public Domain – Software verfügbar gemacht werden. Es wird über die zu erwartenden Standardprozeduren und die erforderliche Hardware zur Anwendung der Normen informiert.
T2 - DGZfP-Jahrestagung
CY - Kassel, Germany
DA - 23.05.2022
KW - Röntgenröhre
KW - Brennfleckmessung
KW - Normung
PY - 2022
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-561029
SP - 1
EP - 10
AN - OPUS4-56102
LA - deu
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Schumacher, David
A1 - Jaenisch, Gerd-Rüdiger
A1 - Ewert, U.
A1 - Bircher, B.
A1 - Meli, F.
A1 - Sofiienko, A.
A1 - Steffen, J. P.
A1 - Deresch, A.
T1 - EMPIR-Projekt NanoXSpot: Ringversuch zur Untersuchung der neu entwickelten Methoden für die Brennfleckmessung an Röntgenröhren im Mikro- und Nanometerbereich
N2 - Im Rahmen des EMPIR-Projektes NanoXSpot (Nanometre X-Ray Focal Spot Measurement) werden rückführbare Messverfahren zur Bestimmung der Brennfleckgröße und -form von Röntgenröhren mit Submikrometerauflösung (100 nm – 20 μm) entwickelt, die die Grundlage für die Erarbeitung eines Standardentwurfes bilden. Der Standardentwurf wird bei CEN TC 138 (Non-destructive testing) WG 1 (Radiographic testing) eingereicht und mit ISO und ASTM harmonisiert. Zur Untersuchung der entwickelten Methoden (Brennfleck-CT, Fit-Prozedur für Strichgruppenkörper) und des im Projekt NanoXSpot neu entworfenen Testkörpers, NxS, wurde ein Ringversuch durchgeführt. Dabei wurde sowohl der angestrebte Überlappungsbereich mit EN 12543 Teil 5 (Messung der effektiven Brennfleckgröße von Mini- und Mikrofokus-Röntgenröhren) und ASTM E 2903 (Standard Test Method for Measurement of the Effective Focal Spot Size of Mini and Micro Focus X-ray Tubes) für Brennflecke >5 μm als auch Brennflecke <5 μm untersucht. Im Mittelpunkt standen dabei Stabilität und Wiederholbarkeit der entwickelten Methoden zur Bestimmung der Brennfleckgröße. In diesem Beitrag werden die Ergebnisse des durchgeführten Ringversuches vorgestellt und diskutiert, um Schlussfolgerungen und Empfehlungen für die Vorbereitung eines erweiterten Ringversuchs mit Partnern und Stakeholdern abzuleiten.
T2 - DGZfP-Jahrestagung
CY - Kassel, Germany
DA - 23.05.2022
KW - Brennfleckmessung
KW - Computer-Tomografie
KW - EMPIR
KW - Normung
PY - 2022
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-561037
SP - 1
EP - 2
AN - OPUS4-56103
LA - deu
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Mueller, I.
A1 - Memmolo, V.
A1 - Tschöke, K.
A1 - Moix-Bonet, M.
A1 - Möllenhoff, K.
A1 - Golub, M.
A1 - Sridaran Venkat, R.
A1 - Lugovtsova, Yevgeniya
A1 - Eremin, A.
A1 - Moll, J.
T1 - Performance Assessment for a Guided Wave-Based SHM System Applied to a Stiffened Composite Structure
N2 - To assess the ability of structural health monitoring (SHM) systems, a variety of prerequisites and contributing factors have to be taken into account. Within this publication, this variety is analyzed for actively introduced guided wave-based SHM systems. For these systems, it is not possible to analyze their performance without taking into account their structure and their applied system parameters. Therefore, interdependencies of performance assessment are displayed in an SHM pyramid based on the structure and its monitoring requirements. Factors influencing the quality, capability and reliability of the monitoring system are given and put into relation with state-of-the-art performance analysis in a non-destructive evaluation. While some aspects are similar and can be treated in similar ways, others, such as location, environmental condition and structural dependency, demand novel solutions. Using an open-access data set from the Open Guided Waves platform, a detailed method description and analysis of path-based performance assessment is presented.The adopted approach clearly begs the question about the decision framework, as the threshold affects the reliability of the system. In addition, the findings show the effect of the propagation path according to the damage position. Indeed, the distance of damage directly affects the system performance. Otherwise, the propagation direction does not alter the potentiality of the detection approach despite the anisotropy of composites. Nonetheless, the finite waveguide makes it necessary to look at the whole paths, as singular phenomena associated with the reflections may appear. Numerical investigation helps to clarify the centrality of wave mechanics and the necessity to take sensor position into account as an influencing factor. Starting from the findings achieved, all the issues are discussed, and potential future steps are outlined.
KW - Reliability assessment
KW - Ultrasonic Guided Waves
KW - Structural Health Monitoring
KW - Probability of detection
KW - Path-based analysis
PY - 2022
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-558853
DO - https://doi.org/10.3390/s22197529
VL - 22
IS - 19
SP - 1
EP - 28
PB - MDPI
CY - Basel, Switzerland
AN - OPUS4-55885
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Kazemifard, N.
A1 - Dehkohneh, Abolfazl
A1 - Baradaran Ghavami, S.
T1 - Probiotics and probiotic-based vaccines: A novel approach for improving vaccine efficacy
N2 - Vaccination is defined as the stimulation and development of the adaptive immune system by administering specific antigens. Vaccines' efficacy, in inducing immunity, varies in different societies due to economic, social, and biological conditions. One of the influential biological factors is gut microbiota. Cross-talks between gut bacteria and the host immune system are initiated at birth during microbial colonization and directly control the immune responses and protection against pathogen colonization. Imbalances in the gut microbiota composition, termed dysbiosis, can trigger several immune disorders through the activity of the adaptive immune system and impair the adequate response to the vaccination. The bacteria used in probiotics are often members of the gut microbiota, which have health benefits for the host. Probiotics are generally consumed as a component of fermented foods, affect both innate and acquired immune systems, and decrease infections. This review aimed to discuss the gut microbiota's role in regulating immune responses to vaccination and how probiotics can help induce immune responses against pathogens. Finally, probiotic-based oral vaccines and their efficacy have been discussed.
KW - Probiotics
KW - Gut microbiota
KW - Probiotic-based vaccines
PY - 2022
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-561767
DO - https://doi.org/10.3389/fmed.2022.940454
SN - 2296-858X
VL - 9
SP - 1
EP - 15
PB - Frontiers Media
CY - Lausanne
AN - OPUS4-56176
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Ewert, U.
A1 - Jaenisch, Gerd-Rüdiger
A1 - Schumacher, David
A1 - Zscherpel, U.
A1 - Deresch, A.
A1 - Bircher, B.
A1 - Meli, F.
T1 - Schnelle Messung und tomographische Rekonstruktion von Brennflecken < 5 μm durch Aufnahmen strukturierter Prüfkörper
N2 - Im Europäischen EMPIR-Projekt „NanoXSpot“ (Measurement of the focal spot size of Xray tubes with spot sizes down to 100 nm) werden neue Messmethoden für Brennflecke von Röntgenröhren entwickelt. Teil des Projektes ist die Entwicklung eines zur Lochkameramethode äquivalenten Messverfahrens für kleine Brennflecke. ASTM E 1165-20, Annex A, beschreibt die Bestimmung von Brennfleckgrößen aus Kantenprofilen von Lochaufnahmen für Röntgenröhren mit Brennflecken > 50 μm. Es wurde bereits vorgeschlagen über die Analyse der richtungsabhängigen Kantenunschärfe einer Lochblende und anschließender CT-Rekonstruktion die Intensitätsverteilung des Brennflecks äquivalent zur Lochkameraaufnahme zu berechnen. Die Lochkameramethode, wie in EN 12543-2 und ASTM E 1165-20 beschrieben, ist im unteren Größenbereich für Mikrofokusröhren nicht geeignet, da Pinholes < 10 μm schwer zu fertigen sind und lange Belichtungszeiten erwartet werden. Mit Hilfe exakt gefertigter Lochblenden sowie strukturierter Targets mit
konvergierenden Strukturen wird der Bereich mit der Single-Shot-CT-Methode auf die Messung von Mikrofokusröhren, alternativ zur Vermessung von Kanten oder Strichgruppenkörpern, erweitert. Die rekonstruierten Brennfleckformen werden mit Kantenund Lochkameraaufnahmen quantitativ verglichen, um die Messgenauigkeit zu bewerten.
Außerdem werden CNR und Messzeit bestimmt, um die Wirtschaftlichkeit der Verfahren zu bewerten.
T2 - DGZfP-Jahrestagung
CY - Online meeting
DA - 10.05.2021
KW - Röntgenröhre
KW - Brennfleckmessung
KW - Prüfkörper
KW - Rekonstruktion
PY - 2021
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-561846
SP - 1
EP - 2
AN - OPUS4-56184
LA - deu
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Emmerling, Franziska
A1 - Hoch, C.
T1 - Laudatio Prof. Dr.-Ing. Caroline Röhr
N2 - It is a laudatio on the ocations of Prof. Dr.-Ing. Caroline Röhrs 60th birthday.
KW - Metal-oxides
PY - 2022
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-561877
DO - https://doi.org/10.1002/zaac.202200159
SN - 0044-2313
VL - 648
IS - 10
SP - 1
EP - 2
PB - John Wiley & Sons, Ltd
AN - OPUS4-56187
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Wurster, S.
A1 - Ladu, Luana
T1 - Triple-C: A Tridimensional Sustainability-Oriented Indicator for Assessing Product Circularity in Public Procurement
N2 - Various microlevel circular economy indicators for assessing sustainability and, partly, additional sustainability characteristics have been developed, but an integrated solution considering the environmental, social, and economic pillars remains a research gap. Method: Based on a multimethod approach, including surveys and the analysis of existing sustainability assessment methodologies and standards, this paper proposes a concept for a multidimensional circular economy indicator tailored to public procurers. It relies on attractive existing building blocks including: the ecological scarcity method, European and international sustainability standards and indicators,and the STAR-ProBio-IAT concept. Results: This article presents the concept of the composite indicator Triple-C, consisting of 20 elements and aimed at facilitating sustainable circular public procurement. It is intended to be incorporated into software that facilitates sustainable product decisions among public procurers in Germany. Conclusions: We propose a generic indicator concept covering all three (environmental, social, and economic) sustainability pillars. More research and additional standards are needed to develop the Triple-C concept further into product-specific applications.
KW - Circular economy
KW - Sustainability assessment
KW - Circularity
KW - Ecological scarcity method
KW - Life-cycle assessment
KW - LCA
KW - Life-cycle costing
KW - LCC
KW - Social sustainability
KW - Indicators
PY - 2022
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-564115
DO - https://doi.org/10.3390/su142113936
VL - 14
IS - 21
SP - 1
EP - 23
PB - MDPI
CY - Berlin
AN - OPUS4-56411
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Sanchez Olivares, G.
A1 - Battig, Alexander
A1 - Goller, Sebastian M.
A1 - Rockel, Daniel
A1 - Ramirez Gonzáles, V.
A1 - Schartel, Bernhard
T1 - Imparting Fire Retardancy and Smoke Suppression to Leather during Tanning Processes
N2 - Leather is considered a luxury good when used in seating and upholstery. To improve safety, flame retardancy in leather is usually achieved through various finishing processes such as spray or roller coating. These treatments require processing steps that cost time and are laborintensive. One avenue to achieving flame retardancy in leather is to add flame retardants during the tanning process. However, the influence on flame retardancy exerted by specific intumescent additives specifically added during leather tanning has yet to be investigated. This work explores the roles played by intumescent additive compounds in flame retarding leather when they are added during tanning instead of applied as a coating. Via a systematic investigation of various compound mixtures, the flame retardant effects in the condensed and the gas phases are elucidated. The results show a strong impact of melamine in the gas phase and of polyphosphates in the condensed phase. Their impact was quantified in fire and smoke analysis, showing a 14% reduction in the peak of heat release rate, strongly reduced burning lengths, and a 20% reduction in total smoke release compared to nontreated leather. These results illuminate the key role played by specific compounds in the flame retardancy of leather, particularly when they are added specifically during the tanning process instead of being applied as a coating.
This method has great potential to reduce processing steps, lower costs, and improve material safety.
KW - Leather
KW - Fire protection
KW - Intumescent additives
KW - Smoke suppression
PY - 2022
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-564777
DO - https://doi.org/10.1021/acsomega.2c05633
SN - 2470-1343
VL - 7
IS - 48
SP - 44156
EP - 44169
PB - ACS
AN - OPUS4-56477
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Heßmann, Jennifer
A1 - Hilgenberg, Kai
T1 - New approach for multi-material design: Combination of laser beam and electromagnetic melt pool displacement by induced Lorentz forces
N2 - Multimaterial structures are a promising solution to reduce vehicle weight and save fuel or electric energy in automotive design. However, thermal joining of steel and aluminum alloys is a challenge to overcome due to different material properties and the formation of brittle intermetallic phases. In this study, a new joining approach for producing overlap line-shaped joints is presented. The lower joining partner (EN AW 5754) is melted by a laser beam, and this melt is displaced into a line-shaped cavity of the upper joining partner (1.0330) by induced Lorentz forces. The melt solidifies in the cavity to a material and form-fitting joint. This approach needs no auxiliary joining elements or filler materials. Previous investigation to produce spot-shaped joints by using this approach showed that quality and reproducibility were limited by known melt pool dynamics of aluminum alloys (keyhole collapses). For line-shaped joints, the melt displacement can take place behind the keyhole. This allows the displacement process to be spatially uncoupled from the influence of keyhole collapses. The study shows that this improved the process stability and the quality of the joint. The created line-shaped joints were microstructurally characterized by transversal sections. Intermetallic phases were identified by electron backscatter diffraction and EDX analysis. The detected intermetallic phases consist of a 5–6 μm compact phase seam of Al5.6Fe2 and a needle-shaped phase of Al13Fe4. Tensile shear tests were carried out to quantify the load capacity. It was possible to create a joint with a load capacity of about 2 kN.
KW - Electromagnetic forces
KW - Joining dissimilar materials
KW - Laser beam welding
KW - Steel and aluminium
KW - Lorentz forces
PY - 2022
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-564840
DO - https://doi.org/10.2351/7.0000763
SN - 1042-346X
VL - 35
IS - 1
SP - 1
EP - 8
PB - Laser Institute of America
CY - Orlando, Fla.
AN - OPUS4-56484
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Junge, P.
A1 - Greinacher, M.
A1 - Kober, D.
A1 - Stargardt, Patrick
A1 - Rupprecht, C.
T1 - Metastable Phase Formation, Microstructure, and Dielectric Properties in Plasma-Sprayed Alumina Ceramic Coatings
N2 - The need for new solutions for electrical insulation is growing due to the increased electrification in numerous industrial sectors, opening the door for innovation. Plasma spraying is a fast and efficient way to deposit various ceramics as electrical insulators, which are used in conditions where polymers are not suitable. Alumina (Al2O3) is among the most employed ceramics in the coating industry since it exhibits good dielectric properties, high hardness, and high melting point, while still being cost-effective. Various parameters (e.g., feedstock type, spray distance, plasma power) significantly influence the resulting coating in terms of microstructure, porosity, and metastable phase formation. Consequently, these parameters need to be investigated to estimate the impact on the dielectric properties of plasma-sprayed alumina coatings. In this work, alumina coatings with different spray distances have been prepared via atmospheric plasma spray (APS) on copper substrates. The microstructure, porosity, and corresponding phase formation have been analyzed with optical microscopy, X-ray diffraction (XRD), and scanning electron microscopy (SEM). Moreover, we present an in-depth analysis of the fundamental dielectric properties e.g., direct current (DC) resistance, breakdown strength, dielectric loss tangent, and permittivity. Our results show that decreasing spray distance reduces the resistivity from 6.31 × 109 Ωm (130 mm) to 6.33 × 108 Ωm (70 mm), while at the same time enhances the formation of the metastable δ-Al2O3 phase. Furthermore, space charge polarization is determined as the main polarization mechanism at low frequencies.
KW - Alumina
KW - Plasma spray
KW - Dielectric properties
PY - 2022
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-564394
DO - https://doi.org/10.3390/coatings12121847
SN - 2079-6412
VL - 12
SP - 1
EP - 15
PB - MDPI
CY - Basel
AN - OPUS4-56439
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Nasr Esfahani, M.
A1 - Zare Pakzad, S.
A1 - Li, T.
A1 - Li, X.
A1 - Tasdemir, Z.
A1 - Wollschläger, Nicole
A1 - Leblebici, Y.
A1 - Erdem Alaca, B.
T1 - Effect of Native Oxide on Stress in Silicon Nanowires: Implications for Nanoelectromechanical Systems
N2 - Understanding the origins of intrinsic stress in Si nanowires (NWs) is crucial for their successful utilization as transducer building blocks in next-generation, miniaturized sensors based on anoelectromechanical systems (NEMS). With their small size leading to ultrahigh-resonance frequencies and extreme surface-to-volume ratios, silicon NWs raise new opportunities regarding sensitivity, precision, and speed in both physical and biochemical sensing. With silicon optoelectromechanical properties strongly dependent on the level of NW intrinsic stress, various studies have been devoted to the measurement of such stresses generated, for example, as a result of harsh fabrication processes. However, due to enormous NW surface area, even the native oxide that is conventionally considered as a benign surface condition can cause significant stresses. To address this issue, a combination of nanomechanical characterization and atomistic simulation approaches is developed. Relying only on low-temperature processes, the fabrication approach yields monolithic NWs with optimum boundary conditions, where NWs and support architecture are etched within the same silicon crystal. Resulting NWs are characterized by transmission electron microscopy and micro-Raman spectroscopy. The interpretation of results is carried out through molecular dynamics simulations with ReaxFF potential facilitating the incorporation of humidity and temperature, thereby providing a close replica of the actual oxidation environment - in contrast to previous dry oxidation or self-limiting thermal oxidation studies. As a result, consensus on significant intrinsic tensile stresses on the order of 100 MPa to 1 GPa was achieved as a function of NW critical dimension and aspect ratio. The understanding developed herein regarding the role of native oxide played in the generation of NW intrinsic stresses is important for the design and development of silicon-based NEMS.
KW - Nanoelectromechanical systems (NEMS)
KW - Silicon nanowires
KW - Native oxide
KW - Intrinsic stress
KW - Raman spectroscopy
PY - 2022
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-560471
DO - https://doi.org/10.1021/acsanm.2c02983
SN - 2574-0970
VL - 5
SP - 13276
EP - 13285
PB - ACS Publ.
CY - Washington, DC
AN - OPUS4-56047
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Zabihi, Mohammadmasoud
A1 - Krebber, Katerina
T1 - Approach for Faster Signal Processing in Փ-OTDR Systems Based on Directional Measurement of Fiber Slices Interaction
N2 - In this study, a signal processing approach for heterodyne Փ-OTDR and C-OTDR systems that can obtain external perturbation and its frequency content in a faster way is proposed. We can detect vibrations with the same or better SNR using this processing approach, only with a single step and fast calculation. Fig. 12 shows the comparison of the normalized measurement time for the gamma matrix method and the conventional method throughout the three experiments. The speed of processing using a gamma matrix is ~35%–50% faster compared to a conventional method in high frequency test (PZT), low frequency test (walking) and street monitoring test. The processing speed in low frequency test is normally a bit lower than the similar high frequency one, since we must use higher number of time frames. Also, in street test we have higher speed because we can select wider gauges.
KW - Փ-OTDR
PY - 2022
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-560492
DO - https://doi.org/10.1364/OPTCON.456421
VL - 1
IS - 8
SP - 1837
EP - 1847
PB - Optica Publishing Group
CY - Washington, DC
AN - OPUS4-56049
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Zabihi, Mohammadmasoud
A1 - Krebber, Katerina
T1 - Laser source frequency drift compensation in Φ-OTDR systems using multiple probe frequencies
N2 - In this study, an approach for mitigation of LSFD in Φ-OTDR systems was proposed. By using one probe pulse as a reference in a system with two or more probe frequencies, we can remove unwanted low frequency noise that is originally caused by the laser source. Although LSFD is problematic issue, it is not the only source of low frequency noise. Change in temperature, humidity, physical surroundings, environment, etc., can result in such noises. The proposed method; however, is expected to highly suppresses all of these effects, regardless of their source, either in the time or frequency domain.
For comparing reference and probe signals, there are sophisticated methods, rather than normal differentiation, available for use. Some of these methods have a close relationship with CPD methods and can further enhance the results. These methods can be further discussed in an independent research or future work.
The proposed method is very helpful for increasing accuracy in passive and active seismic monitoring, reservoir monitoring, underwater monitoring, etc. It also helps using relatively simpler laser sources and make the whole system price-efficient, as well as processing data without lengthy compensation algorithms.
KW - Frequency Drift
KW - Փ-OTDR
KW - LSFD
PY - 2022
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-560517
DO - https://doi.org/10.1364/oe.460302
SN - 1094-4087
VL - 30
IS - 11
SP - 19990
EP - 19998
PB - Optica
CY - Washington, DC
AN - OPUS4-56051
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Steinhäuser, Lorin
A1 - Piechotta, Christian
A1 - Westphalen, Tanja
A1 - Kaminski, Katja
T1 - Evaluation, comparison and combination of molecularly imprinted polymer solid phase extraction and classical solid phase extraction for the preconcentration of endocrine disrupting chemicals from representative whole water samples
N2 - Estrogens are endocrine disrupting chemicals and of high concerns due to demonstrated harmful effects on the environment and low effect levels. For monitoring and risk assessment, several estrogens were included in the "watch list" of the EU Water Framework Directive which sets very low environmental quality standard (EQS) levels for Estrone (E1) and 17β-Estradiol (E2) of 0.4 ng L−1 and for 17α-Ethinylestradiol (EE2) of 0.035 ng L−1 requiring sensitive detection methods, as well as extensive sample preparation. A sensitive, derivatization-free, isotope dilution calibration HPLC-MS/MS method for a panel of 5 selected estrogens (including the 3 estrogens of the EU WFD watchlist), and a procedure for the reproducible preparation of a representative whole water matrix including mineral water, humic acids and solid particulate matter are presented. These are used in a diligent comparison of classical solid phase extraction (SPE) on hydrophilic-lipophilic balanced (HLB) phase to SPE on an estrogen-specific molecularly imprinted polymer phase (MISPE) for ultra-trace levels of the analytes (1–10 ng L−1). Additionally, a two-step procedure combining HLB SPE disks followed by MISPE is evaluated. The tow-step procedure provides superior enrichment, matrix removal and sample throughput while maintaining comparable recovery rates to simple cartridge SPE. Estimated method quantification limits (MQLs) range from 0.109–0.184 ng L−1 and thus meet EQS-levels for E1 and E2, but not EE2. The representative whole water matrix provides a reproducible comparison of sample preparation methods and lays the foundation for a certified reference material for estrogen analysis. The presented method will serve as the basis for an extended validation study to assess its use for estrogen monitoring in the environment.
KW - Estrogens
KW - Whole water samples
KW - Molecular imprinted polymers
KW - EU-WFD
PY - 2022
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-563547
DO - https://doi.org/10.1016/j.talo.2022.100163
SN - 2666-8319
VL - 6
SP - 1
EP - 5
PB - Elsevier B.V.
CY - Amsterdam, Niederlande
AN - OPUS4-56354
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Ehlers, Henrik
A1 - Thewes, R.
A1 - Pelkner, Matthias
T1 - Online Process Monitoring for Additive Manufacturing Using Eddy Current Testing With Magnetoresistive Sensor Arrays
N2 - The rising popularity of additive manufacturing processes leads to an increased interest in possibilities and methods for related process monitoring. Such methods ensure improved process quality and increase the understanding of the manufacturing process, which in turn is the basis for stable component quality, e.g., required in the aerospace industry or in the medical sector. For laser powder bed fusion, a handful of process monitoring tools already exist, such as optical tomography, thermography, pyrometry, imaging, or laser power monitoring. Although these tools provide helpful information about the process, more information is required for an accurate in-depth understanding. In this article, advanced approaches in eddy current testing (ET) are combined, such as single wire excitation, magnetoresistive (MR) sensor arrays, and heterodyning to build up a system that can be used for online process monitoring of laser powder bed fusion. In addition to detailed information about the developed ET system and underlying signal processing, the first results of magnetoresistance-basedonline ET during the laser powder fusion process are presented. While producing a step-shaped cuboid, each layer is tested during recoating.
Test results show that not only the contours of the topmost layer are detected but also the contours of previous layers covered by powder. At an excitation frequency of 1 MHz, a penetration depth of approx. 400 μm is obtained. To highlight the possibilities of ET for online process monitoring of laser powder bed fusion, results are compared with postexposure images of the integrated layer control system (LCS).
KW - Process monitoring
KW - Eddy current testing
KW - Giant magneto resistance (GMR)
KW - Additive manufacturing
KW - Laser powder bed fusion
PY - 2022
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-560881
DO - https://doi.org/10.1109/JSEN.2022.3205177
VL - 22
IS - 20
SP - 19293
EP - 19300
PB - IEEE
CY - New York, NY
AN - OPUS4-56088
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Wiehle, Philipp
A1 - Brinkmann, M.
T1 - Material behaviour of unstabilised earth block masonry and its components under compression at varying relative humidity
N2 - block and mortar types is analysed with particular regard to the influence of varying relative humidity. The uniaxial compressive strength and deformation characteristics of unstabilised earth blocks and mortars as well as of unstabilised earth block masonry are studied in detail and compared to conventional masonry to evaluate whether the structural design can be made accordingly. An increase of 30 % points in relative humidity leads to a reduction of the masonry´s compressive strength between 33 % and 35 % whereas the Young´s modulus is reduced by 24–29 %. However, the ratio between the Young´s modulus and the characteristic compressive strength of earth block masonry ranges between E33/fk = 283–583 but is largely independent of the relative humidity. The results show that the mechanical properties of the investigated unstabilised earth block masonry are sufficient for load-bearing structures, yielding a masonry compressive strength between 2.3 MPa and 3.7 MPa throughout the range of moisture contents
investigated. In general, the design concept of conventional masonry can be adapted for unstabilised earth masonry provided that the rather low Young´s modulus as well as the moisture dependence of both, compressive strength and Young´s modulus, are sufficiently taken into
account.
KW - Compressive strength
KW - Earth block masonry
KW - Compression tests
KW - Stress-strain relation
KW - Relative humidity
KW - Moisture content
PY - 2022
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-562417
DO - https://doi.org/10.1016/j.cscm.2022.e01663
SN - 2214-5095
VL - 17
SP - 1
EP - 15
PB - Elsevier B.V.
CY - Netherlands
AN - OPUS4-56241
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Hong, H.
A1 - Part, Florian
A1 - Nowack, B.
T1 - Prospective dynamic and probabilistic material flow analysis of graphene-based materials in Europe from 2004 to 2030
N2 - As industrial demand for graphene-based materials (GBMs) grows, more attention falls on potential environmental risks. The present article describes a first assessment of the environmental releases of GBMs using dynamic probabilistic material flow analysis. The model considered all current or expected uses of GBMs from 2004 to 2030, during which time there have already been significant changes in how the graphene mass produced is distributed to different product categories. Although the volume of GBM production is expected to grow exponentially in the coming years, outflow from the consumption of products containing GBMs shows only a slightly positive trend due to their long lifetimes and the large in-use stock of some applications (e.g., GBM composites used in wind turbine blades). From consumption and end-of-life phase GBM mass flows in 2030, estimates suggest that more than 50% will be incinerated and oxidized in waste plants, 16% will be landfilled, 12% will be exported out of Europe, and 1.4% of the annual production will flow to the environment. Predicted release concentrations for 2030 are 1.4 ng/L in surface water and 20 μg/kg in sludge-treated soil. This study’s results could be used for prospective environmental risk assessments and as input for environmental fate models.
KW - Graphene
KW - Graphene-based material (GBM)
KW - Material flow analysis
KW - Exposure modeling
PY - 2022
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-568843
DO - https://doi.org/10.1021/acs.est.2c04002
SN - 0013-936X
SN - 1520-5851
VL - 56
SP - 13798
EP - 13809
PB - American Chemical Society
CY - Columbus, Ohio
AN - OPUS4-56884
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Tatzel, M.
A1 - Frings, P. J.
A1 - Oelze, Marcus
A1 - Herwartz, D.
A1 - Lünsdorf, K.
A1 - Wiedenbeck, M.
T1 - Chert oxygen isotope ratios are driven by Earth's thermal evolution
N2 - The 18O/16O ratio of cherts (δ18Ochert) increases nearly monotonically by ~15‰ from the Archean to present. Two end-member explanations have emerged: cooling seawater temperature (TSW) and increasing seawater δ18O (δ18Osw). Yet despite decades of work, there is no consensus, leading some to view the δ18Ochert record as pervasively altered.
Here, we demonstrate that cherts are a robust archive of diagenetic temperatures, despite metamorphism and exposure to meteoric fluids, and show that the timing and temperature of quartz precipitation and thus δ18Ochert are determined by the kinetics of silica diagenesis. A diagenetic model shows that δ18Ochert is influenced by heat flow through the sediment column. Heat flow has decreased over time as planetary heat is dissipated, and reasonable Archean-modern heat flow changes account for ~5‰ of the increase in δ18Ochert, obviating the need for extreme TSW or δ18Osw reconstructions. The seawater oxygen isotope budget is also influenced by solid Earth cooling, with a recent reconstruction placing Archean δ18OSW 5 to 10‰ lower than today. Together, this provides an internally consistent view of the δ18Ochert record as driven by solid Earth cooling over billion-year timescales that is compatible with Precambrian glaciations and biological.
KW - Climate
KW - Oxygen isotope ratios
KW - Silica diagenesis
KW - Early Earth
KW - Heat flow
PY - 2022
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-569359
DO - https://doi.org/10.1073/pnas.2213076119
SN - 0027-8424
VL - 119
IS - 51
SP - 1
EP - 7
PB - National Academy of Sciences
CY - Washington, DC
AN - OPUS4-56935
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Merz, Benjamin
A1 - Nilsson, R.
A1 - Garske, C.
A1 - Hilgenberg, Kai
T1 - Camera-based high precision position detection for hybrid additive manufacturing with laser powder bed fusion
N2 - Additive manufacturing (AM) in general and laser powder bed fusion (PBF-LB/M) in particular are becoming increasingly important in the field of production technologies. Especially the high achievable accuracies and the great freedom in design make PBF-LB/M interesting for the manufacturing and repair of gas turbine blades. Part repair involves building AM-geometries onto an existing component. To minimise the offset between component and AM-geometry, a precise knowledge of the position of the component in the PBF-LB/M machine is mandatory. However, components cannot be inserted into the PBF-LB/M machine with repeatable accuracy, so the actual position will differ for each part. For an offset-free build-up, the actual position of the component in the PBF-LB/M machine has to be determined. In this paper, a camera-based position detection system is developed considering PBF-LB/M constraints and system requirements. This includes finding an optimal camera position considering the spatial limitations of the PBF-LB/M machine and analysing the resulting process coordinate systems. In addition, a workflow is developed to align different coordinate systems and simultaneously correct the perspective distortion in the acquired camera images. Thus, position characteristics can be determined from images by image moments. For this purpose, different image segmentation algorithms are compared. The precision of the system developed is evaluated in tests with 2D objects. A precision of up to 30μm in translational direction and an angular precision of 0.021∘ is achieved. Finally, a 3D demonstrator was built using this proposed hybrid strategy. The offset between base component and AM-geometry is determined by 3D scanning and is 69μm.
KW - Laser powder bed fusion
KW - Additive manufacturing
KW - Hybrid repair
KW - Machine vision
KW - Image processing
KW - Position detection
PY - 2023
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-568583
DO - https://doi.org/10.1007/s00170-022-10691-5
SP - 1
EP - 16
PB - Springer
AN - OPUS4-56858
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Nerger, Tino
A1 - Neumann, Patrick P.
A1 - Weller, Michael G.
T1 - Drone-Based Localization of Hazardous Chemicals by Passive Smart Dust
N2 - The distribution of tiny sensors over a specific area was first proposed in the late 1990s as a concept known as smart dust. Several efforts focused primarily on computing and networking capabilities, but quickly ran into problems related to power supply, cost, data transmission, and environmental pollution. To overcome these limitations, we propose using paper-based (confetti-like) chemosensors that exploit the inherent selectivity of chemical reagents, such as colorimetric indicators. In this work, cheap and biodegradable passive sensors made from cellulose could successfully indicate the presence of hazardous chemicals, e.g., strong acids, by a significant color change. A conventional color digital camera attached to a drone could easily detect this from a safe distance. The collected data were processed to define the hazardous area. Our work presents a combination of the smart dust concept, chemosensing, paper-based sensor technology, and low-cost drones for flexible, sensitive, economical, and rapid detection of hazardous chemicals in high-risk scenarios.
KW - Cellulose
KW - Passive Smart Dust
KW - Drohne
KW - Kolorimetrische Sensoren
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-614641
DO - https://doi.org/10.3390/s24196195
VL - 24
IS - 19
SP - 1
EP - 16
PB - MDPI
AN - OPUS4-61464
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Breuninger, Esther S.
A1 - Tolu, Julie
A1 - Aemisegger, Franziska
A1 - Thurnherr, Iris
A1 - Bouchet, Sylvain
A1 - Mestrot, Adrien
A1 - Ossola, Rachele
A1 - McNeill, Kristopher
A1 - Tukhmetova, Dariya
A1 - Vogl, Jochen
A1 - Meermann, Björn
A1 - Sonke, Jeroen E.
A1 - Winkel, Lenny H. E.
T1 - Marine and terrestrial contributions to atmospheric deposition fluxes of methylated arsenic species
N2 - Arsenic, a toxic element from both anthropogenic and natural sources, reaches surface environments through atmospheric cycling and dry and wet deposition. Biomethylation volatilizes arsenic into the atmosphere and deposition cycles it back to the surface, affecting soil-plant systems. Chemical speciation of deposited arsenic is important for understanding further processing in soils and bioavailability. However, the range of atmospheric transport and source signature of arsenic species remain understudied. Here we report significant levels ofmethylated arsenic in precipitation, cloudwater and aerosols collected under free tropospheric conditions at Pic du Midi Observatory (France) indicating long-range transport, which is crucial for atmospheric budgets. Through chemical analyses andmoisture source diagnostics, we identify terrestrial and marine sources for distinct arsenic species. Estimated atmospheric deposition fluxes of methylated arsenic are similar to reported methylation rates in soils, highlighting atmospheric deposition as a significant, overlooked source of potentially bioavailable methylated arsenic
species impacting plant uptake in soils.
KW - Arsenic
KW - Speciation
KW - Fluxes
KW - Marine
KW - Terrestrial
KW - Sulfur isotopes
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-615551
DO - https://doi.org/10.1038/s41467-024-53974-z
SN - 2041-1723
VL - 15
IS - 1
SP - 1
EP - 13
PB - Springer Science and Business Media LLC
AN - OPUS4-61555
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Yagdjian, H.
A1 - Lecompagnon, Julien
A1 - Hirsch, Philipp Daniel
A1 - Ziegler, Mathias
A1 - Gurka, M.
T1 - Application of the thermal shock response spectrum (TSRS) methodology to various forms of heat sources by pulse thermography and comparison by using a rotating line scan contour search algorithm
N2 - In this paper, we propose a novel contour search algorithm (CSA) for image processing. Its efficacy is evaluated through a comparative analysis with established techniques such as Canny Edge and Snakes: Active contour models, utilizing infrared thermography (IRT) images. Based on the new CSA, we investigate the influence of different pulse shapes on the IRT post-processing methodology, particularly focusing on the thermal shock response spectrum (TSRS), using two different heat sources: xenon flash lamps and a laser. Moreover, this allows for a more precise quantitative comparison of the TSRS with existing IRT post-processing techniques, including pulse phase thermography and thermal signal reconstruction, concerning the detection of defects in composite materials, particularly in carbon fiber-reinforced polymer. A quantitative comparison was performed using the Tanimoto criterion and signal-to-noise ratio. A more detailed analysis is conducted to identify inherent limitations and potential benefits of the new TSRS methodology. We further investigate and experimentally confirm our previous finding on the qualitative correlation between the one-dimensional thermal N-layer model and test data from the TSRS optimization process for defect determination. This correlation can eliminate the time-consuming optimization step, making TSRS a more attractive alternative to common IRT methods and enhancing the quantitative description of defects.
KW - Thermography
KW - Non-destructive testing
KW - NDT
KW - Defect identification
KW - Laser
KW - Contour search
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-615056
DO - https://doi.org/10.1063/5.0232015
SN - 1089-7550
VL - 136
IS - 175101
SP - 1
EP - 20
PB - AIP Publishing
AN - OPUS4-61505
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Abed, Jehad
A1 - Bai, Yanh
A1 - Persaud, Daniel
A1 - Kim, Jiheon
A1 - Witt, Julia
A1 - Hattrick.Simpers, Jason
A1 - Sargent, Edward
T1 - AMPERE: automated modular platform for expedited and reproducible electrochemical testing
N2 - Rapid and reliable electrochemical screening is critical to accelerate the development of catalysts for sustainable energy generation and storage. This paper introduces an automated and modular platform for expedited and reproducible electrochemical testing (AMPERE), designed to enhance the efficiency and reliability of multivariate optimization. The platform integrates a liquid-handling robot with custommade modular array reactors, offering sample preparation and electrochemical testing in the same platform. Additionally, we use offline inductively coupled plasma optical emission spectroscopy (ICPOES) to measure metal concentrations in the electrolyte after the reaction, which serves as a proxy for assessing the electrochemical stability. We use the platform to conduct 168 experiments continuously in less than 40 hours to examine the influence of catalyst ink formulation on the performance of Ir, Ru, IrO2, and RuO2 for the oxygen evolution reaction (OER) in acid. We specifically investigate the role of solvent type and concentration, catalyst concentration, and binder content on the performance. We find that Ru/RuO2 catalysts show improvements in activity that are not directly linked to improvements in the electrochemical surface area or inversely correlated to Ru dissolution. This suggests a complex interplay between the catalytic performance of the drop-casted catalyst film and ink formulation. AMPERE simplifies catalyst preparation and testing at large scale, making it faster, more reliable, and accessible for
widespread use.
KW - Electrochemical screening
KW - Automated platform
KW - Catalysis
KW - Energy generation and storage
KW - Oxygen evolution reaction (OER)
KW - MAPz@BAM
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-614724
DO - https://doi.org/10.1039/d4dd00203b
SP - 1
EP - 10
PB - Royal Society of Chemistry (RSC)
AN - OPUS4-61472
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Jauregui Rozo, Maria
A1 - Sunder, S:
A1 - Ruckdäschel, H.
A1 - Schartel, Bernhard
T1 - Char, gas, and action: Transfer of the flame-retardant modes of action in epoxy resins and their fiber-reinforced composites
N2 - Flame retardants are often developed for epoxy resins and then transferred into their fiber-reinforced composites with uncertain results. Understanding this transfer in detail represents a critical scientific challenge. This study systematically compares epoxy resins with their glass-fiber reinforced composites, focusing on bisphenol A diglycidyl ether with the hardener dicyandiamide, the flame retardants melamine polyphosphate, ammonium polyphosphate, and silane ammonium polyphosphate, along with inorganic silicate. The research investigates changes in pyrolysis (thermogravimetry), flammability (UL 94, limiting oxygen index), and fire behavior (cone calorimeter) while also examining the flame-retardant modes of action and overall fire performance. The findings reveal that alterations in the amount of fuel, thermal properties, melt flow, and protective layer significantly impact ignition, flammability, and fire load, with a critical reduction in carbonaceous char within the composites preventing intumescence. This study quantifies the effects and provides a fundamental scientific understanding of the complex transfer process of flame retardants from resins to composites, offering essential insights that are of major importance for developing more effective flame-retardant materials.
KW - Glas fibers
KW - Epoxy resins
KW - Fire behavior
KW - Flammability
KW - Composites
KW - Flame retardants
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-615371
DO - https://doi.org/10.1016/j.polymertesting.2024.108610
SN - 0142-9418
SN - 1873-2348
VL - 140
PB - Elsevier Ltd.
AN - OPUS4-61537
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Chaudhuri, Somsubhro
A1 - Stamm, Michael
A1 - Lapšanská, Ivana
A1 - Lançon, Thibault
A1 - Osterbrink, Lars
A1 - Driebe, Thomas
A1 - Hein, Daniel
A1 - Harendt, René
T1 - Infrared Thermography of Turbulence Patterns of Operational Wind Turbine Rotor Blades Supported With High‐Resolution Photography: KI‐VISIR Dataset
N2 - With increasing wind energy capacity and installation of wind turbines, new inspection techniques are being explored to examine wind turbine rotor blades, especially during operation. A common result of surface damage phenomena (such as leading edge erosion) is the premature transition of laminar to turbulent flow on the surface of rotor blades. In the KI-VISIR (Künstliche Intelligenz Visuell und Infrarot Thermografie—Artificial Intelligence-Visual and Infrared Thermography) project, infrared thermography is used as an inspection tool to capture so-called thermal turbulence patterns (TTPs) that result from such surface contamination or damage. To complement the thermographic inspections, high-resolution photography is performed to visualise, in detail, the sites where these turbulence patterns initiate. A convolutional neural network (CNN) was developed and used to detect and localise turbulence patterns. A unique dataset combining the thermograms and visual images of operational wind turbine rotor blades has been provided, along with the simplified annotations for the turbulence patterns. Additional tools are available to allow users to use the data requiring only basic Python programming skills.
KW - Thermography
KW - Thermografie
KW - Wind energy
KW - Leading edge erosion
KW - KI
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-615772
DO - https://doi.org/10.1002/we.2958
IS - e2958
SP - 1
EP - 9
PB - Wiley
AN - OPUS4-61577
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Vo, P. H.N.
A1 - Vogel, Christian
A1 - Nguyen, H. T.M.
A1 - Hamilton, B. R.
A1 - Thai, P. K.
A1 - Roesch, Philipp
A1 - Simon, Franz-Georg
A1 - Mueller, J. F.
T1 - µ-X-ray fluorescence (XRF) and fluorine K-edge µ-X-ray absorption near-edge structure (XANES) spectroscopy for detection of PFAS distribution in the impacted concrete
N2 - An improved understanding of the distribution of per- and polyfluoroalkyl substances (PFAS) in PFAS-impacted concrete is important for risk management and decontamination of PFAS. This study incorporates µ-X-ray fluorescence (µ-XRF) and fluorine K-edge µ-X-ray absorption near-edge structure (µ-XANES) spectroscopy to gain non-destructive insights into PFAS distribution in the impacted concrete. The μ-XRF and μ-XANES spectroscopy provided additional details on the detection of PFAS, which were not detected by the desorption electrospray ionization (DESI) imaging method conducted previously. The shorter chain PFAS were found on the top part of the concrete core (0.5 cm), and longer chain PFAS were mostly at the bottom part of the concrete core (5 cm). The inorganic fluorine fraction was also detected, and it likely hampered the detection of organic fluorine such as PFAS in the concrete. Thus, this non-destructive technique is an complementary approach to detect PFAS in contaminated concrete.
KW - Beton
KW - Per- and Polyfluoroalkyl substances (PFAS)
KW - XANES spectroscopy
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-616711
DO - https://doi.org/10.1016/j.hazl.2024.100134
SN - 2666-9110
VL - 5
SP - 1
EP - 5
PB - Elsevier B.V.
AN - OPUS4-61671
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Lu, Xin
A1 - Krebber, Katerina
T1 - Suppression of Rayleigh fading induced errors in φOTDR by different pulse widths for improving the reliability of civil infrastructure monitoring
N2 - Rayleigh fading is a widely observed phenomenon in the many fields, such as wireless communication and optical imaging. It is also the main factor limiting the performance of the phase-sensitive optical time domain reflectometry (φOTDR). The low SNR at the fading points results in a large measurement error, severely affecting the reliability of civil infrastructure monitoring. The proposed method involves changing the pulse width during measurements to suppress the impact of fading. Experimental result shows that the number of fading points is greatly reduced by ∼ 96 % and the measurement error is reduced by more than 5 times. Unlike existing methods, this approach requires no hardware modifications, making it applicable to almost all current phase-based φOTDR systems. The versatility and effectiveness of this method make it an excellent candidate for infrastructure monitoring and related fields.
KW - Distributed fiber sensing
KW - Optical fiber sensing
KW - Phase-sensitive optical time domain reflectometry
KW - Infrastructure monitoring
KW - Rayleigh fading
PY - 2025
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-614208
DO - https://doi.org/10.1016/j.optlastec.2024.111927
SN - 1879-2545
VL - 181
SP - 1
EP - 9
PB - Elsevier Ltd.
AN - OPUS4-61420
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Zweigle, J.
A1 - Schmidt, A.
A1 - Bugsel, B.
A1 - Vogel, Christian
A1 - Simon, Fabian
A1 - Zwiener, C.
T1 - Perfluoroalkyl acid precursor or weakly fluorinated organic compound? A proof of concept for oxidative fractionation of PFAS and organofluorines
N2 - Organofluorine mass balance approaches are increasingly applied to investigate the occurrence of per- and polyfluoroalkyl substances (PFAS) and other organofluorines in environmental samples more comprehensively. Usually, complex samples prevent the identification and quantification of every fluorine-containing molecule. Consequently, large unidentified fractions between fluorine sum parameters such as extractable organic fluorine (EOF) and the sum of quantified analytes are frequently reported. We propose using oxidative conversion to separate (unidentified) weakly fluorinated compounds (e.g., pesticides, pharmaceuticals) from PFAA-precursors (perfluoroalkyl chain lengths ≥ C6). We show with three organofluorine model substances (flufenamic acid, diflufenican, pantoprazole) that CF3-groups or aromatic fluorine can be quantitatively converted to inorganic fluoride and trifluoroacetic acid (TFA) by applying PhotoTOP oxidation (UV/TiO2). The principle of fluorine separation in mixtures is demonstrated by the oxidation of the three weakly fluorinated compounds together with the PFAA-precursor 6:2/6:2 fluorotelomer mercaptoalkyl phosphate diester (FTMAP). After oxidation, the products F− and TFA were separated from PFCAs ( C4) by SPE, and the fractions were analyzed individually. Closed mass balances both with and without the addition of organic matrix were achieved. Eventually, the fluorine balance was verified by total fluorine measurements with combustion ion chromatography (CIC). The proposed methods should be considered a proof of concept to potentially explain unidentified fractions of the EOF, especially if compounds with low fluorine content such as pesticides, pharmaceuticals, and their transformation products contribute largely to the EOF. Future studies are needed to show the applicability to the complexity of environmental samples.
Graphical Abstract
KW - Combustion Ion Chromatography
KW - Per- and Polyfluoroalkyl substances (PFAS)
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-613429
DO - https://doi.org/10.1007/s00216-024-05590-5
SP - 1
EP - 10
PB - Springer Science and Business Media LLC
AN - OPUS4-61342
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Yagdjian, H.
A1 - Lecompagnon, Julien
A1 - Hirsch, Philipp Daniel
A1 - Gurka, M.
T1 - Optimization of thermal shock response spectrum as infrared thermography post-processing methodology using Latin hypercube sampling and analytical thermal N-layer model
N2 - In this work, we continue to develop and investigate the Thermal Shock Response Spectrum (TSRS) method as an alternative data processing method for infrared thermography (IRT). We focus on improving the current TSRS algorithm and present an optimization methodology for finding the optimal thermal Q-factor and characteristic frequency pair, which is based on the widely applied random sampling method. We show the qualitative relationship between the determined optimal characteristic frequency and the corresponding maximum difference in diffusion length between reference and defective models, as calculated by selecting a specific one-dimensional thermal N-layer model. The investigations were performed on an inhomogeneous plate made of carbon fiber reinforced polymer (CFRP) with artificial square defects at different depths. Furthermore, two different heat sources were used: a xenon flash lamp and a laser. These sources are not only distinct by their underlying physics but also generate inherently different pulse shapes. To quantitatively estimate the contrast between defect and non-defect areas, and to compare these results with commonly used infrared thermography (IRT) data postprocessing methods such as Pulse Phase Thermography (PPT) and Thermographic Signal Reconstruction (TSR), the Tanimoto criterion (TC) and signal-to-noise ratio (SNR) were used.
KW - infrared thermography
KW - Composite materials
KW - TSRS optimization
KW - Defect identification
KW - Heat source shape
KW - N-layers model
KW - Latin Hypercube Sampling
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-614283
DO - https://doi.org/10.1016/j.infrared.2024.105582
SN - 1350-4495
VL - 143
SP - 1
EP - 15
PB - Elsevier B.V.
AN - OPUS4-61428
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Bianchi, M.
A1 - Cascavilla, A.
A1 - Clavell Diaz, J.
A1 - Ladu, Luana
A1 - Palacino Blazquez, Barbara
A1 - Menger, Pierre
A1 - Staffieri, Eleonora
A1 - Yilan, Gülsah Yilan
T1 - Circular bioeconomy: A review of empirical practices across implementation scales
N2 - The European Commission has endorsed the transition to a circular bioeconomy as a crucial initiative to achieve a sustainable and climate-neutral European Union. However, this transition is inherently complex, as it involves environmental and social risks, physical limitations, and trade-offs between different dimensions of sustainability. In this context, effective monitoring and modelling of the bioeconomy are essential tools to inform decision-making at various implementation scales. This article reviews empirical research on the monitoring and modelling of the bioeconomy and their implications for decision-making across three main implementation scales: macro (national-global level); meso (regional-city level); and micro (single product, company level). The contribution of this research is twofold: First, it explores existing gaps in the field through the lens of policy implementation levels. Research gaps include the uneven distribution of indicators among sustainability pillars, the lack of standardised monitoring frameworks at the meso and micro levels, and attribution issues in bioeconomy modelling. Second, the article outlines a comprehensive research agenda, indicating specific research lines and their relevance to different implementation scales. Key research avenues, significant at all implementation scales, include enhancing the life cycle perspective, visualising trade-offs and synergies between Sustainable Development Goals, monetising externalities, and further delving into social aspects.
KW - Bioeconomy
KW - Circular Economy
KW - Sustainable Transition
KW - Bioeconomy Monitoring Framework
KW - Bioeconomy Indicators
KW - Life cycle management
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-612357
DO - https://doi.org/10.1016/j.jclepro.2024.143816
VL - 477
SP - 1
EP - 16
PB - Elsevier
AN - OPUS4-61235
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - D'Agostino, Giancarlo
A1 - Oelze, Marcus
A1 - Vogl, Jochen
A1 - Ghestem, Jean-Philippe
A1 - Lafaurie, Nicolas
A1 - Klein, Ole
A1 - Pröfrock, Daniel
A1 - Di Luzio, Marco
A1 - Bergamaschi, Luigi
A1 - Jaćimović, Radojko
A1 - Oster, Caroline
A1 - Irrgeher, Johanna
A1 - Lancaster, Shaun T.
A1 - Walch, Anna
A1 - Röthke, Anita
A1 - Michaliszyn, Lena
A1 - Pramann, Axel
A1 - Rienitz, Olaf
A1 - Sara-Aho, Timo
A1 - Cankur, Oktay
A1 - Kutan, Derya
A1 - Noireaux, Johanna
T1 - Development and application of reference and routine analytical methods providing SI-traceable results for the determination of technology-critical elements in PCB from WEEE
N2 - The recovery and reprocessing of technology-critical elements (TCE) present in printed circuit boards (PCB) from electrical and electronic waste is essential both for recycling valuable materials subject to supply risk and for reducing the environmental impact. Although the quantitative knowledge of TCE amounts in endof- life PCB plays a key role, there are neither matrix certified reference materials nor harmonized analytical methods available to establish the traceability of the results to the International System of Units. To fill these gaps, we developed and applied five reference analytical methods based on ICP-MS standard addition calibrations and INAA k0- and relative calibrations suitable to certify reference materials. In addition, we developed and tested six analytical methods based on more commonly used ICP-MS external standard calibrations to provide industry with routine analysis methods. Twenty TCE (Ag, Au, Co, Cu, Dy, Ga, Gd, Ge, In, La, Li, Nd, Ni, Pd, Pr, Pt, Rh, Sm, Ta and Ti) were selected as target analytes and a batch of powdered PCB was used as measurement material. An overall mutual agreement was observed among data collected by reference methods at a few percent relative uncertainty levels. Moreover, all but one of the methods developed for routine analysis demonstrated their suitability in industrial applications by producing data within ± 20% of the values established with reference methods.
KW - Technology critical elements
KW - Electronic waste
KW - Printed circuit boards
KW - Traceability
KW - Uncertainty
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-612416
DO - https://doi.org/10.1039/d4ja00235k
SN - 1364-5544
VL - 39
IS - 11
SP - 2809
EP - 2823
PB - Royal Society of Chemistry (RSC)
AN - OPUS4-61241
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Lancaster, Shaun T.
A1 - Sahlin, Eskil
A1 - Oelze, Marcus
A1 - Ostermann, Markus
A1 - Vogl, Jochen
A1 - Laperche, Valérie
A1 - Touze, Solène
A1 - Ghestem, Jean-Philippe
A1 - Dalencourt, Claire
A1 - Gendre, Régine
A1 - Stammeier, Jessica
A1 - Klein, Ole
A1 - Pröfrock, Daniel
A1 - Košarac, Gala
A1 - Jotanovic, Aida
A1 - Bergamaschi, Luigi
A1 - Di Luzio, Marco
A1 - D’Agostino, Giancarlo
A1 - Jaćimović, Radojko
A1 - Eberhard, Melissa
A1 - Feiner, Laura
A1 - Trimmel, Simone
A1 - Rachetti, Alessandra
A1 - Sara-Aho, Timo
A1 - Roethke, Anita
A1 - Michaliszyn, Lena
A1 - Pramann, Axel
A1 - Rienitz, Olaf
A1 - Irrgeher, Johanna
T1 - Evaluation of X-ray fluorescence for analysing critical elements in three electronic waste matrices: A comprehensive comparison of analytical techniques
N2 - As the drive towards recycling electronic waste increases, demand for rapid and reliable analytical methodology to analyse the metal content of the waste is increasing, e.g. to assess the value of the waste and to decide the correct recycling routes. Here, we comprehensively assess the suitability of different x-ray fluorescence spectroscopy (XRF)-based techniques as rapid analytical tools for the determination of critical raw materials, such as Al, Ti, Mn, Fe, Co, Ni, Cu, Zn, Nb, Pd and Au, in three electronic waste matrices: printed circuit boards (PCB), light emitting diodes (LED), and lithium (Li)-ion batteries. As validated reference methods and materials to establish metrological traceability are lacking, several laboratories measured test samples of each matrix using XRF as well as other independent complementary techniques (instrumental neutron activation analysis (INAA), inductively coupled plasma mass spectrometry (ICP-MS) and ICP optical emission spectrometry (OES)) as an inter-laboratory comparison (ILC). Results highlighted key aspects of sample preparation, limits of detection, and spectral interferences that affect the reliability of XRF, while additionally highlighting that XRF can provide more reliable data for certain elements compared to digestion-based approaches followed by ICP-MS analysis (e.g. group 4 and 5 metals). A clear distinction was observed in data processing methodologies for wavelength
dispersive XRF, highlighting that considering the metals present as elements (rather than oxides) induces overestimations of the mass fractions when compared to other techniques. Eventually, the effect of sample particle size was studied and indicated that smaller particle size (<200 μm) is essential for reliable determinations.
KW - XRF
KW - WEEE
KW - PCB
KW - Battery
KW - LED
KW - Recycling
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-614060
DO - https://doi.org/10.1016/j.wasman.2024.10.015
VL - 190
SP - 496
EP - 505
PB - Elsevier B.V.
AN - OPUS4-61406
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Lengas, Nikolaos
A1 - Müller, Karsten
A1 - Schlick‐Hasper, Eva
A1 - Neitsch, Marcel
A1 - Johann, Sergej
A1 - Zehn, Manfred W.
T1 - Drop Test Simulation of Packaging for Dangerous Goods: An Investigation of Appropriate Drop Height Adjustment in Case of Deviating Packaging Gross Mass
N2 - In the approval process of dangerous goods packagings, drop tests onto a flat, essentially unyielding surface are used to assess resistance against mechanical damage. International adopted regulations like ADR and RID define filling good dependent drop heights and filling degrees whilst the user needs to define the maximum gross mass to be tested and approved. Maximum packaging gross mass is defined conservatively and not reached in practice. To meet the defined gross mass in testing, using additives is permitted. However, in some cases, additives are not desirable due to packaging design or filling substance properties. This leads to deviations from the initial gross mass definition. Hence, a certain drop height adjustment is necessary to achieve the required impact loading. Laboratories frequently adjust drop height assuming a perfectly elastic collision that is inaccurate. Appropriate adjustment is not trivial due to energy conversion processes, for example, plastic deformation. In this work, a test stand
KW - Corrugated fibreboard box
KW - Dangerous goods packagings
KW - Drop test
KW - Impact target
KW - Mechanical response
KW - Structural dynamics
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-614138
DO - https://doi.org/10.1002/pts.2858
SP - 1
EP - 18
PB - Wiley
AN - OPUS4-61413
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Cios, G.
A1 - Winkelmann, A.
A1 - Nolze, Gert
A1 - Tokarski, T.
A1 - Jany, B. R.
A1 - Bala, P.
T1 - EBSD and TKD analyses using inverted contrast Kikuchi diffraction patterns and alternative measurement geometries
N2 - Electron backscatter diffraction (EBSD) patterns can exhibit Kikuchi bands with inverted contrast due to anomalous absorption. This can be observed, for example, on samples with nanoscale topography, in case of a low tilt backscattering geometry, or for transmission Kikuchi diffraction (TKD) on thicker samples. Three examples are discussed where contrast-inverted physics-based simulated master patterns have been applied to find the correct crystal orientation. As first EBSD example, self-assembled gold nanostructures made of Au fcc and Au hcp phases on single-crystal germanium were investigated. Gold covered about 12% of the mapped area, with only two thirds being successfully interpreted using standard Hough-based indexing. The remaining third was solved by brute force indexing using a contrast-inverted master pattern. The second EBSD example deals with maps collected at a non-tilted surface instead of the commonly used 70◦ tilted one. As TKD example, a jet-polished foil made of duplex stainless steel 2205 was examined. The thin part close to the hole edge producing normal-contrast patterns were standard indexed. The areas of the foil that become thicker with increasing distance from the edge of the hole produce contrast-inverted patterns. They covered three times the evaluable area and were successfully processed using the contrast-inverted master pattern. In the last example, inverted patterns collected at a non-tiled sample were mathematically inverted to normal contrast, and Hough/Radon-based indexing was successfully applied.
KW - EBSD
KW - TKD
KW - Contrast inversion
KW - Topography
KW - Kikuchi diffraction
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-613862
VL - 267
SP - 1
EP - 8
PB - Elsevier
CY - Amsterdam
AN - OPUS4-61386
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Weichert, Dorina
A1 - Kister, Alexander
A1 - Houben, Sebastian
A1 - Link, Patrick
A1 - Ernis, Gunar
ED - Kiyavash, Negar
ED - Mooij, Joris M.
T1 - Robust Entropy Search for Safe Efficient Bayesian Optimization
N2 - The practical use of Bayesian Optimization (BO) in engineering applications imposes special requirements: high sampling efficiency on the one hand and finding a robust solution on the other hand. We address the case of adversarial robustness, where all parameters are controllable during the optimization process, but a subset of them is uncontrollable or even adversely perturbed at the time of application. To this end, we develop an efficient information-based acquisition function that we call Robust Entropy Search (RES). We empirically demonstrate its benefits in experiments on synthetic and real-life data. The results show that RES reliably finds robust optima, outperforming state-of-the-art algorithms.
T2 - UAI 2024
CY - Barcelona, Spain
DA - 15.07.2024
KW - Bayesian Optimization
KW - Gaussian process
KW - Active learning
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-613523
UR - https://proceedings.mlr.press/v244/weichert24a.html
SN - 2640-3498
VL - 244
SP - 3711
EP - 3729
PB - Proceedings of Machine Learning Research
AN - OPUS4-61352
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Kader, A.
A1 - Snellings, J.
A1 - Adams, L. C.
A1 - Gottheil, P.
A1 - Mangarova, D. B.
A1 - Heyl, J. L.
A1 - Kaufmann, Jan Ole
A1 - Moeckel, J.
A1 - Brangsch, J.
A1 - Auer, T. A.
A1 - Collettini, F.
A1 - Sauer, F.
A1 - Hamm, B.
A1 - Käs, J.
A1 - Sack, I.
A1 - Makowski, M. R.
A1 - Braun, J.
T1 - Sensitivity of magnetic resonance elastography to extracellular matrix and cell motility in human prostate cancer cell line-derived xenograft models
N2 - Prostate cancer (PCa) is a significant health problem in the male population of the Western world. Magnetic resonance elastography (MRE), an emerging medical imaging technique sensitive to mechanical properties of biological tissues, detects PCa based on abnormally high stiffness and viscosity values. Yet, the origin of these changes in tissue properties and how they correlate with histopathological markers and tumor aggressiveness are largely unknown, hindering the use of tumor biomechanical properties for establishing a noninvasive PCa staging system.
To infer the contributions of extracellular matrix (ECM) components and cell motility, we investigated fresh tissue specimens from two PCa xenograft mouse models, PC3 and LNCaP, using magnetic resonance elastography (MRE), diffusion-weighted imaging (DWI), quantitative histology, and nuclear shape analysis. Increased tumor stiffness and impaired water diffusion were observed to be associated with collagen and elastin accumulation and decreased cell motility. Overall, LNCaP, while more representative of clinical PCa than PC3, accumulated fewer ECM components, induced less restriction of water diffusion, and exhibited increased cell motility, resulting in overall softer and less viscous properties. Taken together, our results suggest that prostate tumor stiffness increases with ECM accumulation and cell adhesion - characteristics that influence critical biological processes of cancer development.
MRE paired with DWI provides a powerful set of imaging markers that can potentially predict prostate tumor development from benign masses to aggressive malignancies in patients. Statement of significance: Xenograft models of human prostate tumor cell lines, allowing correlation of microstructure-sensitive biophysical imaging parameters with quantitative histological methods, can be investigated to identify hallmarks of cancer.
KW - Magnetic resonance elastography
KW - Quantitative histology
KW - Prostate cancer
KW - Stiffness
KW - Fluidity
KW - Apparent diffusion coefficient
KW - Collagen
KW - Elastin
KW - Nuclear shape
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-618361
DO - https://doi.org/10.1016/j.bioadv.2024.213884
SN - 2772-9508
VL - 161
SP - 1
EP - 12
PB - Elsevier
CY - Amsterdam
AN - OPUS4-61836
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Schilling, Markus
A1 - Bruns, Sebastian
A1 - Bayerlein, Bernd
A1 - Kryeziu, Jehona
A1 - Schaarschmidt, Jörg
A1 - Waitelonis, Jörg
A1 - Dolabella Portella, Pedro
A1 - Durst, Karsten
T1 - Seamless Science: Lifting Experimental Mechanical Testing Lab Data to an Interoperable Semantic Representation
N2 - The scientific landscape is undergoing rapid transformations with the advent of the digital age which revolutionizes research methodologies. In materials science and engineering, an adoption of modern data management techniques is desirable to maximize the efficiency and accessibility of research efforts. Traditional practices in testing laboratories are usually inadequate for efficient data acquisition and utilization as they lead to local storage and difficulty in publication and correlation with other results. Electronic laboratory notebooks (ELNs) are promising prospects in this respect. Semantic concepts and ontologies enhance interoperability by standardizing experimental data representation. An in‐laboratory pipeline seamlessly integrating an ELN with transformation scripts to convert experimental into interoperable data in a machine‐actionable format is created in this study as a proof of concept. Tensile test results and the corresponding tensile test ontology are used exemplary. Linking ELN data to semantic concepts enriches the stored information while improving interpretability and reusability. Involving undergraduate students builds a bridge between theory and practice during their training and promotes their digital skills. This study underscores the potential of ELNs and knowledge representations as beneficial means toward improved data management practices that enhance collaborative research and education while ensuring compatibility with evolving standards and technologies.
KW - Semantic Data
KW - Data Integration
KW - Tensile Test Ontology
KW - Electronic Lab Notebook
KW - Wissensrepräsentation
KW - Education
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-618251
DO - https://doi.org/10.1002/adem.202401527
SP - 1
EP - 13
PB - Wiley VHC-Verlag
AN - OPUS4-61825
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Bosc-Bierne, Gaby
A1 - Ewald, Shireen
A1 - Kreuzer, Oliver J.
A1 - Weller, Michael G.
T1 - Efficient Quality Control of Peptide Pools by UHPLC and Simultaneous UV and HRMS Detection
N2 - Peptide pools consist of short amino acid sequences and have proven to be versatile tools in various research areas in immunology and clinical applications. They are commercially available in many different compositions and variants. However, unlike other reagents that consist of only one or a few compounds, peptide pools are highly complex products which makes their quality control a major challenge. Quantitative peptide analysis usually requires sophisticated methods, in most cases isotope-labeled standards and reference materials. Usually, this would be prohibitively laborious and expensive. Therefore, an approach is needed to provide a practical and feasible method for quality control of peptide pools. With insufficient quality control, the use of such products could lead to incorrect experimental results, worsening the well-known reproducibility crisis in the biomedical sciences. Here we propose the use of ultra-high performance liquid chromatography (UHPLC) with two detectors, a standard UV detector at 214 nm for quantitative analysis and a high-resolution mass spectrometer (HRMS) for identity confirmation. To be cost-efficient and fast, quantification and identification are performed in one chromatographic run. An optimized protocol is shown, and different peak integration methods are compared and discussed. This work was performed using a peptide pool known as CEF advanced, which consists of 32 peptides derived from cytomegalovirus (CMV), Epstein–Barr virus (EBV) and influenza virus, ranging from 8 to 12 amino acids in length.
N2 - Peptidpools bestehen aus kurzen Aminosäuresequenzen und haben sich als vielseitige Werkzeuge in verschiedenen Forschungsbereichen der Immunologie und bei klinischen Anwendungen erwiesen. Sie sind in vielen verschiedenen Zusammensetzungen und Varianten im Handel erhältlich. Im Gegensatz zu anderen Reagenzien, die nur aus einer oder wenigen Verbindungen bestehen, sind Peptidpools jedoch hochkomplexe Produkte, was ihre Qualitätskontrolle zu einer großen Herausforderung macht. Die quantitative Peptidanalyse erfordert in der Regel ausgefeilte Methoden, in den meisten Fällen isotopenmarkierte Standards und Referenzmaterialien. Dies ist in der Regel sehr aufwändig und teuer. Daher wird ein Ansatz benötigt, der eine praktische und praktikable Methode zur Qualitätskontrolle von Peptidpools bietet. Bei unzureichender Qualitätskontrolle könnte die Verwendung solcher Produkte zu falschen Versuchsergebnissen führen, was das bekannte Problem der Reproduzierbarkeit in den biomedizinischen Wissenschaften noch verschärfen würde. Hier schlagen wir die Verwendung der Ultrahochleistungs-Flüssigkeitschromatographie (UHPLC) mit zwei Detektoren vor, einem Standard-UV-Detektor bei 214 nm für die quantitative Analyse und einem hochauflösenden Massenspektrometer (HRMS) für die Identitätsbestätigung. Um kosteneffizient und schnell zu sein, werden Quantifizierung und Identifizierung in einem einzigen chromatographischen Lauf durchgeführt. Es wird ein optimiertes Protokoll gezeigt, und es werden verschiedene Peak-Integrationsmethoden verglichen und diskutiert. Für diese Arbeit wurde ein Peptidpool verwendet, der als CEF advanced bekannt ist und aus 32 Peptiden besteht, die vom Cytomegalovirus (CMV), Epstein-Barr-Virus (EBV) und Influenzavirus stammen und zwischen 8 und 12 Aminosäuren lang sind.
KW - Synthetic peptides
KW - Quality control
KW - Impurites
KW - Byproducts
KW - Degradation
KW - Mass spectrometry
KW - Orbitrap
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-602299
DO - https://doi.org/10.3390/separations11050156
SN - 2297-8739
VL - 11
IS - 5
SP - 1
EP - 18
PB - MDPI
CY - Basel
AN - OPUS4-60229
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Gregório, Bruno J.R.
A1 - Ramos, Inês I.
A1 - Marques, Sara S.
A1 - Barreiros, Luísa
A1 - Magalhães, Luís M.
A1 - Schneider, Rudolf
A1 - Segundo, Marcela A.
T1 - Microcarrier-based fluorescent yeast estrogen screen assay for fast determination of endocrine disrupting compounds
N2 - The presence of endocrine-disrupting compounds (EDCs) in water poses a significant threat to human and animal health, as recognized by regulatory agencies throughout the world. The Yeast Estrogen Screen (YES) assay is an excellent method to evaluate the presence of these compounds in water due to its simplicity and capacity to assess the bioaccessible forms/fractions of these compounds. In the presence of a compound with estrogenic activity, Saccharomyces cerevisiae cells, containing a lacZ reporter gene encoding the enzyme β-galactosidase, are induced, the enzyme is synthesised, and released to the extracellular medium. In this work, a YES-based approach encompassing the use of a lacZ reporter gene modified strain of S. cerevisiae, microcarriers as solid support, and a fluorescent substrate, fluorescein di-β-D-galactopyranoside, is proposed, allowing for the assessment of EDCs’ presence after only 2 h of incubation. The proposed method provided an EC50 of 0.17 ± 0.03 nM and an LLOQ of 0.03 nM, expressed as 17β-estradiol. The assessment of different EDCs provided EC50 values between 0.16 and 1.2 × 103 nM. After application to wastewaters, similar results were obtained for EDCs screening, much faster, compared to the conventional 45 h spectrophotometric procedure using a commercial kit, showing potential for onsite high-throughput screening of environmental contamination.
KW - Biosensoren
KW - YES assay
KW - Endokrine Disruptoren
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-602315
DO - https://doi.org/10.1016/j.talanta.2024.125665
VL - 271
SP - 1
EP - 7
PB - Elsevier B.V.
CY - Amsterdam
AN - OPUS4-60231
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Braymer, Joseph J.
A1 - Stehling, Oliver
A1 - Stümpfig, Martin
A1 - Rösser, Ralf
A1 - Spantgar, Farah
A1 - Blinn, Catharina M.
A1 - Mühlenhoff, Ulrich
A1 - Pierik, Antonio J.
A1 - Lill, Roland
T1 - Requirements for the biogenesis of [2Fe-2S] proteins in the human and yeast cytosol
N2 - The biogenesis of iron–sulfur (Fe/S) proteins entails the synthesis and trafficking of Fe/S clusters, followed by their insertion into target apoproteins. In eukaryotes, the multiple steps of biogenesis are accomplished by complex protein machineries in both mitochondria and cytosol. The underlying biochemical pathways have been elucidated over the past decades, yet the mechanisms of cytosolic [2Fe-2S] protein assembly have remained ill-defined. Similarly, the precise site of glutathione (GSH) requirement in cytosolic and nuclear Fe/S protein biogenesis is unclear, as is the molecular role of the GSH-dependent cytosolic monothiol glutaredoxins (cGrxs). Here, we investigated these questions in human and yeast cells by various in vivo approaches. [2Fe-2S] cluster assembly of cytosolic target apoproteins required the mitochondrial ISC machinery, the mitochondrial transporter Atm1/ABCB7 and GSH, yet occurred independently of both the CIA system and cGrxs. This mechanism was strikingly different from the ISC-, Atm1/ABCB7-, GSH-, and CIA-dependent assembly of cytosolic–nuclear [4Fe-4S] proteins. One notable exception to this cytosolic [2Fe-2S] protein maturation pathway defined here was yeast Apd1 which used the CIA system via binding to the CIA targeting complex through its C-terminal tryptophan. cGrxs, although attributed as [2Fe-2S] cluster chaperones or trafficking proteins, were not essential in vivo for delivering [2Fe-2S] clusters to either CIA components or target apoproteins. Finally, the most critical GSH requirement was assigned to Atm1-dependent export, i.e. a step before GSH-dependent cGrxs function. Our findings extend the general model of eukaryotic Fe/S protein biogenesis by adding the molecular requirements for cytosolic [2Fe-2S] protein maturation.
KW - Biokorrosion
KW - Hydrogenasen
KW - Microbially Induced Corrosion
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-602328
DO - https://doi.org/10.1073/pnas.2400740121
SN - 0027-8424
VL - 121
IS - 21
SP - 1
EP - 12
PB - Proceedings of the National Academy of Sciences
CY - Washington D.C.
AN - OPUS4-60232
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Tabaka, Weronika
A1 - Meinel, Dietmar
A1 - Schartel, Bernhard
T1 - Sacrifice Few to Save Many: Fire Protective Interlayers in Carbon- Fiber-Reinforced Laminates
N2 - The fire protection of carbon-fiber-reinforced polymer (CFRP) laminates often relies on flame-retardant coatings, but in some applications, their efficacy may diminish upon direct fire exposure due to rapid pyrolysis. This study introduces an innovative approach by integrating protective interlayers within the laminate structure to enhance the fire resistance. Various materials, including ceramic composite WHIPOX, titanium foil, poly(etherimide) (PEI) foil, basalt fibers, rubber mat, and hemp fibers, were selected as protective interlayers. These interlayers were strategically placed within the laminate layout to form a sacrificial barrier, safeguarding the integrity of the composite. Bench-scale fire resistance tests were conducted, where fire (180 kW/m2) was applied directly to the one side of the specimen by a burner while a compressive load was applied at the same time. Results indicate significant prolongation of time to failure for CFRP laminates with protective interlayers, which is up to 10 times longer. This innovative approach represents a potential advance in fire protection strategies for CFRP laminates, offering improved resilience against fire-induced structural failure.
KW - Composites in fire
KW - Fire resistance
KW - Fire retardant interlayers
KW - Laminate design
KW - Carbon fibre reinforced
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-601943
DO - https://doi.org/10.1021/acsomega.4c01408
SN - 2470-1343
VL - 9
IS - 22
SP - 23703
EP - 23712
PB - ACS
AN - OPUS4-60194
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Dace, Elina
A1 - Cascavilla, Alessandro
A1 - Bianchi, Marco
A1 - Chioatto, Elisa
A1 - Zecca, Emy
A1 - Ladu, Luana
A1 - Yilan, Gülsah
T1 - Barriers to transitioning to a circular bio-based economy: Findings from an industrial perspective
N2 - The transition from a linear fossil-based to a circular bio-based economy represents an opportunity and a suitable pathway for achieving several sustainable development goals. However, the transition is a complex process since it requires transformative policies, purposeful innovation, access to finance, risk-taking capacity as well as new and sustainable business models and markets. Accordingly, the first step in this transition process is the identification of barriers that are hampering the transition to a sustainable circular bio-based economy. With this motivation in mind, this study reviews grey literature to identify barriers focusing on four critical sectors facing major challenges within the current linear economy and requiring a sustainable transition most urgently: construction, chemicals, plastics, and textile sectors. Employing an adapted STEEP methodology (Social, Technological, Economical, Environmental, Political), a total of 193 different barriers have been identified and clustered under six categories: cultural, technical, economic, environmental, governance, and structural. Regardless of the sector, cultural and structural barriers are identified as the most prominent; the lack of incentives for consumer behaviour change and lack of stakeholder collaboration were the most cited barriers among the literature records. From a value chain perspective, most of the barriers are related to the material processing and product manufacturing stage. Finally, potential solutions, extracted from the grey literature, are proposed to fill the gaps and overcome the identified barriers. Many of the identified barriers are common across the four investigated sectors, indicating the solutions or measures can be applicable in a wider perspective to promote the transition in the right direction.
KW - Circular Bio-based Economy
KW - Barriers
KW - Sustainability
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-602062
DO - https://doi.org/10.1016/j.spc.2024.05.029
VL - 48
SP - 407
EP - 418
PB - Elsevier Ltd.
AN - OPUS4-60206
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Albakri, Bashar
A1 - Turski Silva Diniz, Analice
A1 - Benner, Philipp
A1 - Muth, Thilo
A1 - Nakajima, Shinichi
A1 - Favaro, Marco
A1 - Kister, Alexander
ED - Hillman, Robert
T1 - Machine learning-assisted equivalent circuit identification for dielectric spectroscopy of polymers
N2 - Polymers have become indispensable across fields of application, and understanding their structure–property relationships and dynamic behaviour is essential for performance optimization. Polymer membranes, particularly ion exchange membranes, play a crucial role in renewable energy conversion technologies, fuel cells, solar energy conversion, and energy storage. In this context, broadband dielectric spectroscopy (BDS) offers a powerful, non-destructive approach to investigate the electrical response and relaxation dynamics of polymers. These properties are investigated by parametrizing the system’s impedance response in terms of a network of circuit elements, i.e. the electrical equivalent circuit (EEC), whose impedance resembles the one of the system under investigation. However, the determination of the EEC from BDS data is challenging due to system complexity, interdependencies of circuit elements, and researcher biases. In this work, we propose a novel approach that incorporates a convolutional neural network (CNN) model to predict the EEC topology. By reducing user bias and enhancing data analysis, this approach aims to make BDS accessible to both experienced users and those with limited expertise. We show that the combination of machine learning and BDS provides valuable insights into the dynamic behaviour of polymer membranes, thus facilitating the design and characterization of tailored polymers for various applications. We also show that our model outperforms state-of-the-art machine learning methods with a top-5 accuracy of around 80% for predicting the circuit topology and a parameter fitting error as low as 0.05%.
KW - Polymer membranes
KW - Electrochemical impedance spectroscopy
KW - Broadband dielectric spectroscopy
KW - Deep learning
KW - Machine learning
KW - Equivalent circuit
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-602138
DO - https://doi.org/10.1016/j.electacta.2024.144474
SN - 0013-4686
VL - 496
SP - 1
EP - 13
PB - Elsevier Ltd.
AN - OPUS4-60213
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Groschke, Matthias
A1 - Becker, Roland
T1 - Comparison of carrier gases for the separation and quantification of mineral oil hydrocarbon (MOH) fractions using online coupled high performance liquid chromatography-gas chromatography-flame ionisation detection
N2 - On-line coupled high performance liquid chromatography-gas chromatography-flame ionisation detection (HPLC-GC-FID) was used to compare the effect of hydrogen, helium and nitrogen as carrier gases on the chromatographic characteristics for the quantification of mineral oil hydrocarbon (MOH) traces in food related matrices. After optimisation of chromatographic parameters nitrogen carrier gas exhibited characteristics equivalent to hydrogen and helium regarding requirements set by current guidelines and standardisation such as linear range, quantification limit and carry over. Though nitrogen expectedly led to greater peak widths, all required separations of standard compounds were sufficient and humps of saturated mineral oil hydrocarbons (MOSH) and aromatic mineral oil hydrocarbons (MOAH) were appropriate to enable quantitation similar to situations where hydrogen or helium had been used. Slightly increased peak widths of individual hump components did not affect shapes and widths of the MOSH and MOAH humps were not significantly affected by the use of nitrogen as carrier gas. Notably, nitrogen carrier gas led to less solvent peak tailing and smaller baseline offset. Overall, nitrogen may be regarded as viable alternative to hydrogen or helium and may even extend the range of quantifiable compounds to highly volatile hydrocarbon eluting directly after the solvent peak.
KW - Mineral oil hydrocarobons
KW - Food
KW - Liquid chromatography
KW - Gas chromatography
KW - MOSH/MOAH
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-601450
DO - https://doi.org/10.1016/j.chroma.2024.464946
SN - 0021-9673
VL - 1726
SP - 1
EP - 7
PB - Elsevier
CY - New York, NY
AN - OPUS4-60145
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Schepers, Winfried
A1 - Kulke, D.
T1 - Cone penetration tests and dynamic soil properties
N2 - ISO 14837-32:2015 and DIN EN 1998-1/NA:2021 as well as prEN 1997-2:2022 allow for us-ing correlations between the results of in-situ soil penetration tests and shear wave velocity (or shear modulus) to determine soil properties to be used in dynamic analyses. While the ISO and prEN standards even provide some recommendations on specific correlations to be used, the DIN standard does not. Due to the statistical nature of such correlations their general applica-bility has to be verified. We collected data sets from test sites from Germany as well as New Zealand at which cone penetration tests (CPT) as well as seismic site investigation methods were conducted. These sites comprise sandy soils as well as clayey soils, mixed soils as well as glacial soils. We compare the results of several correlations between CPT results and shear wave velocity. The accuracy of such correlations is assessed with respect to the accuracy of seismic in-situ tests. It turns out that for clean sands such correlations between CPT and Vs have a similar order of variability as seismic in-situ tests conducted at the same site. The higher the fines portion of the soil, the higher the variability of the statistical correlations, and conse-quently the less the general applicability. For glacial soils and other special soil types usage of statistical correlations to determine dynamic soil properties is not recommended.
T2 - XII International Conference on Structural Dynamics
CY - Delft, Netherlands
DA - 02.07.2023
KW - Wave propagation
KW - Soil properties
KW - Dynamic excitation
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-604887
DO - https://doi.org/10.1088/1742-6596/2647/25/252005
VL - 2647
SP - 1
EP - 11
PB - IOP Publishing
CY - Bristol
AN - OPUS4-60488
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Schepers, Winfried
A1 - Brinkgreve, RBJ
A1 - Appel, S.
T1 - Recommendations on finite element modelling of non-seismic excitation in soil-structure interaction problems
N2 - Nowadays geotechnical engineering firms have powerful software tools to extent their consult-ing business also into dynamic soil-structure interaction, which before has been restricted to a rather small community of specialized experts in this field, and they certainly do. This is par-ticularly true with respect to non-seismic sources, that is all kinds of human induced vibrations. Hence, there is a demand from clients as well as from contractors to have guidance on the re-quirements as well as the limits of numerical modelling of soil-structure interaction. From the literature as well as from relevant standards, recommendations for the numerical modelling of soil-structure interaction problems involving seismic actions are well known, e. g. ASCE/SEI 4-16. There are, however, some particularities when dealing with human-induced vibrations, which are absent in seismic analyses. For human-induced excitations very little specific guid-ance has been published in the past. A machine foundation on a homogeneous half space ex-cited by harmonic loads with excitation frequency between 4 Hz and 64 Hz has been ana-lysed by means of several commercially available software packages. Parametric studies have been performed to verify if recommendations for seismic soil-structure analyses are valid for non-seismic analyses as well. This paper provides details on the benchmark example and the most important conclusions from the undertaken parametric studies.
T2 - XII International Conference on Structural Dynamics
CY - Delft, Netherlands
DA - 02.07.2023
KW - Numerische Analysen
KW - Referenzbeispiel
KW - Maschinenfundament
KW - Wellenausbreitung
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-604931
DO - https://doi.org/10.1088/1742-6596/2647/8/082014
SN - 1742-6596
VL - 2647
IS - 25
SP - 1
EP - 13
PB - IOP Publishing
AN - OPUS4-60493
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Li, Guiping
A1 - Liu, Ye
A1 - Schultz, Thorsten
A1 - Exner, Moritz
A1 - Muydinov, Ruslan
A1 - Wang, Hui
A1 - Scheurell, Kerstin
A1 - Huang, Jieyang
A1 - Szymoniak, Paulina
A1 - Pinna, Nicola
A1 - Koch, Norbert
A1 - Adelhelm, Philipp
A1 - Bojdys, Michael J.
T1 - One‐Pot Synthesis of High‐Capacity Sulfur Cathodes via In‐Situ Polymerization of a Porous Imine‐Based Polymer
N2 - AbstractLithium‐ion batteries, essential for electronics and electric vehicles, predominantly use cathodes made from critical materials like cobalt. Sulfur‐based cathodes, offering a high theoretical capacity of 1675 mAh g−1 and environmental advantages due to sulfur's abundance and lower toxicity, present a more sustainable alternative. However, state‐of‐the‐art sulfur‐based electrodes do not reach the theoretical capacities, mainly because conventional electrode production relies on mixing of components into weakly coordinated slurries. Consequently, sulfur‘s mobility leads to battery degradation—an effect known as the “sulfur‐shuttle”. This study introduces a solution by developing a microporous, covalently‐bonded, imine‐based polymer network grown in situ around sulfur particles on the current collector. The polymer network (i) enables selective transport of electrolyte and Li‐ions through pores of defined size, and (ii) acts as a robust host to retain the active component of the electrode (sulfur species). The resulting cathode has superior rate performance from 0.1 C (1360 mAh g−1) to 3 C (807 mAh g−1). Demonstrating a high‐performance, sustainable sulfur cathode produced via a simple one‐pot process, our research underlines the potential of microporous polymers in addressing sulfur diffusion issues, paving the way for sulfur electrodes as viable alternatives to traditional metal‐based cathodes.
KW - In-situ polymerization
KW - Sulfur cathodes
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-604215
DO - https://doi.org/10.1002/anie.202400382
SN - 1433-7851
SP - 1
EP - 11
PB - Wiley VHC-Verlag
AN - OPUS4-60421
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Häßler, Dustin
A1 - Mund, Maximilian
A1 - Daus, Lars-Hendrik
A1 - Hothan, Sascha
A1 - Schaumann, Peter
A1 - Schartel, Bernhard
T1 - Durability of intumescent coatings and recommendations for test concepts for a working life of more than 10 years
N2 - It is an essential requirement for all building products to ensure durability of their fire safety. Throughout the working life of products, intumescent coatings are aged by certain climatic factors. To predict a lifetime of several years, generally the behaviour of the intumescent coating is extrapolated based on accelerated artificial ageing. The established German and European procedures to assess the durability assume a working life of at least 10 years. For a longer period, additional evidence is required; yet the procedure and the specifications to justify this are not described. In addition to addressing this formal lack, from a scientific point of view it is necessary to investigate the degradation of intumescent coatings in detail and to propose a reliable test concept to assess durability for more than 10 years. This paper summarises the existing knowledge about the ageing of intumescent coatings. The results of various demanding weathering approaches are presented for two intumescent coatings tested in a joint research project. Moreover, formulations with a reduced amount of functionally relevant components were analysed to gain insight into the associated effects. Derived from these research results and knowledge, recommendations are proposed to assess the durability of intumescent coatings for more than 10 years based on a combination of verifications.
KW - Ageing
KW - Fire protection
KW - Intumescent coating
KW - Steel construction
KW - Working life
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-603852
DO - https://doi.org/10.1016/j.firesaf.2024.104173
SN - 0379-7112
VL - 146
SP - 1
EP - 10
PB - Elsevier B.V.
AN - OPUS4-60385
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Hirsch, Philipp Daniel
A1 - Kunji Purayil, Sruthi Krishna
A1 - Lecompagnon, Julien
A1 - Hassenstein, Christian
A1 - Ziegler, Mathias
T1 - Robotergestützte 3D-Scans und Laserthermografie zur Prüfung an komplexen Bauteilen auf Risse
N2 - Die Integration von Automation und Robotik in die Prüfprozesse ermöglicht die
Untersuchung komplexer Bauteile. Diese Studie präsentiert die robotergestützte
Laserthermografie, um Risse in solchen Bauteilen zu identifizieren und analysieren. Diese Technik ermöglicht die automatisierte Rissprüfung welche im Vergleich zur Farbeindringprüfung auf viele, meist manuelle, Arbeitsschritte sowie die notwendigen Chemikalien verzichtet.
Zusätzlich wird ein automatisiertes Einscannen der Bauteile mithilfe eines
Linienscanners vorgestellt. Dieser Schritt ermöglicht eine detaillierte 3D-Rekonstruktion der Bauteilgeometrie und ermöglicht eine einfache Korrektur von Abweichungen in der Bauteilaufnahme und eröffnet Möglichkeiten zur adaptiven Bahnplanung bei Bauteilverformungen.
Die Rückprojektion der gefundenen Risse auf die Oberfläche des Bauteils kann
automatisiert erfolgen. Dieser Schritt erlaubt nicht nur die Identifikation der Risse, sondern auch eine genauere Analyse ihrer Geometrie und Lage am Bauteil.
Die Kombination von robotergestützter Laserthermografie, automatisiertem 3DScanning und Rückprojektion der Risse auf die Bauteiloberfläche eröffnet neue
Möglichkeiten in der zerstörungsfreien Prüfung von komplexen Bauteilen und erweitert damit mögliche Anwendungsfelder.
T2 - Jahrestagung der Deutschen Gesellschaft für Zerstörungsfreie Prüfung (DGZfP) 2024
CY - Osnabrück, Germany
DA - 06.05.2024
KW - ZFP4.0
KW - Automatisierung
KW - Thermografie
KW - Laser
KW - Roboter
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-604811
UR - https://www.ndt.net/?id=29520
VL - 182
SP - 1
EP - 8
PB - NDT.net
AN - OPUS4-60481
LA - deu
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Maulas, Kryzzyl M.
A1 - Paredes, Charla S.
A1 - Tabelin, Carlito Baltazar
A1 - Jose, Mark Anthony
A1 - Opiso, Einstine M.
A1 - Arima, Takahiko
A1 - Park, Ilhwan
A1 - Mufalo, Walubita
A1 - Ito, Mayumi
A1 - Igarashi, Toshifumi
A1 - Phengsaart, Theerayut
A1 - Villas, Edrhea
A1 - Dagondon, Sheila L.
A1 - Metillo, Ephrime B.
A1 - Uy, Mylene M.
A1 - Manua, Al James A.
A1 - Villacorte-Tabelin, Mylah
T1 - Isolation and Characterization of Indigenous Ureolytic Bacteria from Mindanao, Philippines: Prospects for Microbially Induced Carbonate Precipitation (MICP)
N2 - Microbially induced carbonate precipitation (MICP), a widespread phenomenon in nature, is gaining attention as a low-carbon alternative to ordinary Portland cement (OPC) in geotechnical engineering and the construction industry for sustainable development. In the Philippines, however, very few works have been conducted to isolate and identify indigenous, urease-producing (ureolytic) bacteria suitable for MICP. In this study, we isolated seven, ureolytic and potentially useful bacteria for MICP from marine sediments in Iligan City. DNA barcoding using 16s rDNA identified six of them as Pseudomonas stutzeri, Pseudomonas pseudoalcaligenes, Bacillus paralicheniformis, Bacillus altitudinis, Bacillus aryabhattai, and Stutzerimonas stutzeri but the seventh was not identified since it was a bacterial consortium. Bio-cementation assay experiments showed negligible precipitation in the control (without bacteria) at pH 7, 8, and 9. However, precipitates were formed in all seven bacterial isolates, especially between pH 7 and 8 (0.7–4 g). Among the six identified bacterial species, more extensive precipitation (2.3–4 g) and higher final pH were observed in S. stutzeri, and B. aryabhattai, which indicate better urease production and decomposition, higher CO2 generation, and more favorable CaCO3 formation. Characterization of the precipitates by scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM-EDS) and attenuated total reflectance Fourier transform spectroscopy (ATR-FTIR) confirmed the formation of three carbonate minerals: calcite, aragonite, and vaterite. Based on these results, all six identified indigenous, ureolytic bacterial species from Iligan City are suitable for MICP provided that the pH is controlled between 7 and 8. To the best of our knowledge, this is the first report of the urease-producing ability and potential for MICP of P. stutzeri, P. pseudoalcaligenes, S. stutzeri, and B. aryabhattai.
KW - Calcium carbonate
KW - Microbially induced carbonate precipitation (MICP)
KW - Ureolytic bacteria
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-600888
DO - https://doi.org/10.3390/min14040339
VL - 14
IS - 4
SP - 1
EP - 15
PB - MDPI
AN - OPUS4-60088
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Casperson, Ralf
A1 - Friedrich, Alexander
A1 - Heckel, Thomas
A1 - Zhang, Tianyun
T1 - Verwendung von DICONDE bei der Eisenbahn-Schienenprüfung
N2 - Bei der zerstörungsfreien Prüfung verlegter Eisenbahnschienen werden die Rohdaten derzeit in proprietären Datenformaten gespeichert und auf Datenträgern zwischen den Prüfzügen und den auswertenden Stellen versendet. Die proprietären Datenformate sind in der Regel nur den Herstellern der Prüfsysteme bekannt und deren Dokumentation nicht allgemein zugänglich.
Die „Standard Practice for Digital Imaging and Communication in Nondestructive Evaluation“ (DICONDE), basierend auf dem medizinischen Standard „Digital Imaging and Communication in Medicine“ (DICOM), ermöglicht es, sowohl Prüfdaten als auch Prüfergebnisse und Streckeninformationen in einem standardisierten Format zu speichern und zwischen verschiedenen Endpunkten zu übertragen.
Das Poster gibt zunächst einen kurzen Überblick über die hierarchische Struktur von DICONDE und zeigt dann, wie DICONDE bei der Prüfung verlegter Eisenbahnschienen verwendet werden kann. Die geometrischen Besonderheiten (mehrere Kilometer Länge pro Prüffahrt, kurviger Streckenverlauf) stellen dabei eine besondere Herausforderung dar. Im Rahmen des mFUND-geförderten Projektes „Arteficial Intelligence for Railway Inspection (AIFRI)“, Förderkennzeichen 19FS2014C, wurde ein Vorschlag für eine Erweiterung des DICONDE-Standards für die Schienenprüfung erarbeitet und bei der ASTM eingereicht.
T2 - DGZfP Jahrestagung 2024
CY - Osnabrück, Germany
DA - 05.05.2024
KW - DICONDE
KW - Eisenbahn
KW - Schienenprüfung
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-600204
DO - https://doi.org/10.58286/29500
SP - 1
EP - 5
PB - NDT.net
AN - OPUS4-60020
LA - deu
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Poka, Konstantin
A1 - Ali, Sozol
A1 - Saeed, Waleed
A1 - Merz, Benjamin
A1 - Epperlein, Martin
A1 - Hilgenberg, Kai
T1 - Design and implementation of a machine log for PBF-LB/M on basis of IoT communication architectures and an ETL pipeline
N2 - AbstractPowder Bed Fusion with Laser Beam of Metals (PBF-LB/M) has gained more industrial relevance and already demonstrated applications at a small series scale. However, its widespread adoption in various use cases faces challenges due to the absence of interfaces to established Manufacturing Execution Systems (MES) that support customers in the predominantly data-driven quality assurance. Current state-of-the-art PBF-LB/M machines utilize communication architectures, such as OPC Unified Architecture (OPC UA), Message Queuing Telemetry Transport (MQTT) and Representational State Transfer Application Programming Interface (REST API). In the context of the Reference Architecture Model Industry 4.0 (RAMI 4.0) and the Internet of Things (IoT), the assets, particularly the physical PBF-LB/M machines, already have an integration layer implemented to communicate data such as process states or sensor values. Missing is an MES component acting as a communication and information layer. To address this gap, the proposed Extract Transform Load (ETL) pipeline aims to extract relevant data from the fabrication of each build cycle down to the level of scan vectors and additionally to register process signals. The suggested data schema for archiving each build cycle adheres to all terms defined by ISO/TC 261—Additive Manufacturing (AM). In relation to the measurement frequency, all data are reorganized into entities, such as the AM machine, build cycle, part, layer, and scan vector. These scan vectors are stored in a runtime-independent format, including all metadata, to be valid and traceable. The resulting machine log represents a comprehensive documentation of each build cycle, enabling data-driven quality assurance at process level.
KW - FAIR data
KW - Data-driven quality assurance
KW - Laser powder bed fusion
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-601256
DO - https://doi.org/10.1007/s40964-024-00660-7
SN - 2363-9512
SP - 1
EP - 12
PB - Springer Science and Business Media LLC
AN - OPUS4-60125
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Schlögl, Johanna
A1 - Goldammer, Ole
A1 - Bader, Julia
A1 - Emmerling, Franziska
A1 - Riedel, Sebastian
T1 - Introducing AFS ([Al(SO3F)3]x) – a thermally stable, readily available, and catalytically active solid Lewis superacid
N2 - This paper introduces the thermally stable, solid Lewis superacid aluminium tris(fluorosulfate) (AFS), that is easy-to-synthesize from commercially available starting materials. Its applicability, e.g. in catalytic C–F bond activations, is shown.
KW - Lewis Acid
KW - C-F activation
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-601001
DO - https://doi.org/10.1039/D4SC01753F
SN - 2041-6520
SP - 1
EP - 7
PB - Royal Society of Chemistry (RSC)
AN - OPUS4-60100
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Schmidt, Stephan
A1 - Hoffmann, Holger
A1 - Garbe, Leif-Alexander
A1 - Harrer, Andrea
A1 - Steiner, Markus
A1 - Himly, Martin
A1 - Schneider, Rudolf
T1 - Re-assessment of monoclonal antibodies against diclofenac for their application in the analysis of environmental waters
N2 - The non-steroidal anti-inflammatory drug (NSAID) diclofenac (DCF) is an important environmental contaminant occurring in surface waters all over the world, because, after excretion, it is not adequately removed from wastewater in sewage treatment plants. To be able to monitor this pollutant, highly efficient analytical methods are needed, including immunoassays. In a medical research project, monoclonal antibodies against diclofenac and its metabolites had been produced. Based on this monoclonal anti-DCF antibody, a new indirect competitive enzyme-linked immunosorbent assay (ELISA) was developed and applied for environmental samples. The introduction of a spacer between diclofenac and the carrier protein in the coating conjugate led to higher sensitivity. With a test midpoint of 3 mg L−1 and a measurement range of 1–30 mg L−1, the system is not sensitive enough for direct analysis of surface water. However, this assay is quite robust against matrix influences and can be used for wastewater. Without adjustment of the calibration, organic solvents up to 5%, natural organic matter (NOM) up to 10 mg L−1, humic acids up to 2.5 mg L−1, and salt concentrations up to 6 g L−1 NaCl and 75 mg L−1 CaCl2 are tolerated. The antibody is also stable in a pH range from 3 to 12. Cross-reactivity (CR) of 1% or less was determined for the metabolites 40-hydroxydiclofenac (40-OH-DCF), 5-hydroxydiclofenac (5-OH-DCF), DCF lactam, and other NSAIDs. Relevant cross-reactivity occurred only with an amide derivative of DCF, 6-aminohexanoic acid (DCF-Ahx), aceclofenac (ACF) and DCF methyl ester (DCF-Me) with 150%, 61% and 44%, respectively. These substances, however, have not been found in samples. Only DCF-acyl glucuronide with a cross-reactivity of 57% is of some relevance. For the first time, photodegradation products were tested for cross-reactivity. With the ELISA based on this antibody, water samples were analysed. In sewage treatment plant effluents, concentrations in the range of 1.9–5.2 mg L−1 were determined directly, with recoveries compared to HPLC-MS/MS averaging 136%.
Concentrations in lakes ranged from 3 to 4.4 ng L−1 and were, after pre-concentration, determined with an average recovery of 100%
KW - Antikörper
KW - Immunoassay
KW - Wasser
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-602280
DO - https://doi.org/10.1039/d3ay01333b
VL - 16
IS - 21
SP - 3349
EP - 3363
PB - Royal Society of Chemistry (RSC)
CY - London
AN - OPUS4-60228
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Galleani, Gustavo
A1 - Lodi, Thiago A.
A1 - Conner, Robin L.
A1 - Jacobsohn, Luiz G.
A1 - de Camargo, Andrea Simone Stucchi
T1 - Photoluminescence and X-ray induced scintillation in Gd3+-Tb3+ co-doped fluoride-phosphate glasses, and derived glass-ceramics containing NaGdF4 nanocrystals
N2 - The glass system (50NaPO3–20BaF2–10CaF2–20GdF3)-xTbCl3 with x = 0.3, 1, 3, 5, and 10 wt % was investigated. We successfully produced transparent glass ceramic (GC) scintillators with x = 1 through a melt-quenching process followed by thermal treatment. The luminescence and crystallization characteristics of these materials were thoroughly examined using various analytical methods. The nanocrystallization of Tb3+-doped Na5Gd9F32 within the doped fluoride-phosphate glasses resulted in enhanced photoluminescence (PL) and radioluminescence (RL) of the Tb3+ ions. The GC exhibited an internal PL quantum yield of 33 % and the integrated RL intensity across the UV-visible range was 36 % of that reported for the commercial BGO powder scintillator. This research showcases that Tb-doped fluoridephosphate GCs containing nanocrystalline Na5Gd9F32 have the potential to serve as efficient scintillators while having lower melting temperature compared to traditional silicate and germanate glasses.
KW - Glass scintillator
KW - Fluoride phosphate glasses
KW - Gd3+
KW - Tb3+
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-603588
DO - https://doi.org/10.1016/j.omx.2023.100288
VL - 21
SP - 1
EP - 9
PB - Elsevier B.V.
AN - OPUS4-60358
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Tatzel, Michael
A1 - Oelze, Marcus
A1 - Frick, Daniel A.
A1 - Di Rocco, Tommaso
A1 - Liesegang, Moritz
A1 - Stuff, Maria
A1 - Wiedenbeck, Michael
T1 - Silicon and oxygen isotope fractionation in a silicified carbonate rock
N2 - Silicon isotope fractionation during silicification is poorly understood and impedes our ability to decipher paleoenvironmental conditions from Si isotopes in ancient cherts. To investigate isotope fractionation during silica-for-carbonate replacement we analyzed the microscale Si and O isotope composition in different silica phases in a silicified zebra dolostone as well as their bulk δ18O and Δ’17O compositions. The subsequent replacement of carbonate layers is mimicked by decreasing δ18O and δ30Si. The textural relationship and magnitude of Si and O isotope fractionation is best explained by near-quantitative silica precipitation in an open system with finite Si. A Rayleigh model for silicification suggests positive Ɛ30/28Si during silicification, conforming with predictions for isotope distribution at chemical equilibrium from ab-initio models. Application of the modelled Ɛ30Si-T relationship yields silicification temperatures of approx. 50°C. To reconcile the δ18Ochert composition with these temperatures, the δ18O of the fluid must have been between -2.5 and -4 ‰, compositions for which the quartz phases fall close to the oxygen equilibrium fractionation line in three-isotope space. Diagenetic silica replacement appears to occur in O and Si isotopic equilibrium allowing reconstructions of temperatures of silicification from Si isotopes and derive the δ18O composition of the fluid – a highly desired value needed for accurate reconstructions of the temperature- and δ18O histories of the oceans.
KW - Silicon isotopes
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-603430
DO - https://doi.org/10.1016/j.chemgeo.2024.122120
SN - 0009-2541
VL - 658
SP - 1
EP - 13
PB - Elsevier B.V.
AN - OPUS4-60343
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Wosniok, Aleksander
A1 - Königsbauer, Korbinian
A1 - Nöther, Nils
A1 - Färber, Jan
A1 - Schaller, M.-Barbara
A1 - Krebber, Katerina
T1 - Distributed polymer optical fiber sensors using digital I-OFDR for geotechnical infrastructure health monitoring
N2 - We present a distributed polymer optical fiber sensor system for deformation monitoring of geotechnical infrastructure. The sensor system is based on the digital incoherent optical frequency domain reflectometry (I-OFDR) for the detection of local strain events along a perfluorinated polymer optical fiber (PF-POF) used as a sensing fiber. For the best possible load transfer, the PF-POFs were integrated onto geosynthetics which pose a sensor carrier for the sensing fiber. By using elastic PF-POF instead of a standard glass fiber as a sensing fiber the strain range of geosynthetics-integrated fiber optic sensors could be extended up to 10 % in accordance with the end-user requirements.
T2 - 11th European Workshop on Structural Health Monitoring
CY - Potsdam, Germany
DA - 10.06.2024
KW - Digital I-OFDR
KW - Distributed polymer optical fiber sensor
KW - Ddistributed strain sensing
KW - Smart geosynthetics
KW - Structural health monitoring
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-603096
SP - 1
EP - 7
PB - NDT.net
AN - OPUS4-60309
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Charmi, Amir
A1 - Heimann, Jan
A1 - Duffner, Eric
A1 - Hashemi, Seyedreza
A1 - Prager, Jens
T1 - Application of deep learning for structural health monitoring of a composite overwrapped pressure vessel undergoing cyclic loading
N2 - Structural health monitoring (SHM) using ultrasonic-guided waves (UGWs) enables continuous monitoring of components with complex geometries and provides extensive information about their structural integrity and their overall condition. Composite overwrapped pressure vessels (COPVs) used for storing hydrogen gases at very high pressures are an example of a critical infrastructure that could benefit significantly from SHM. This can be used to increase the periodic inspection intervals, ensure safe operating conditions by early detection of anomalies, and ultimately estimate the remaining lifetime of COPVs. Therefore, in the digital quality infrastructure initiative (QI-Digital) in Germany, an SHM system is being developed for COPVs used in a hydrogen refueling station. In this study, the results of a lifetime fatigue test on a Type IV COPV subjected to many thousands of load cycles under different temperatures and pressures are presented to demonstrate the strengths and challenges associated with such an SHM system. During the cyclic testing up to the final material failure of the COPV, a sensor network of fifteen surface-mounted piezoelectric (PZT) wafers was used to collect the UGW data. However, the pressure variations, the aging process of the COPV, the environmental parameters, and possible damages simultaneously have an impact on the recorded signals. This issue and the lack of labeled data make signal processing and analysis even more demanding. Thus, in this study, semi-supervised, and unsupervised deep learning approaches are utilized to separate the influence of different variables on the UGW data with the final aim of detecting and localizing the damage before critical failure.
T2 - 11th European Workshop on Structural Health Monitoring
CY - Potsdam, Germany
DA - 10.06.2024
KW - Structural health monitoring
KW - Deep learning
KW - Ultrasonic-guided waves
KW - Anomaly detection
KW - Damage localization
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-607396
DO - https://doi.org/10.58286/29751
SP - 1
EP - 8
AN - OPUS4-60739
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Hupp, Vitus
A1 - Schartel, Bernhard
A1 - Flothmeier, K.
A1 - Hartwig, A.
T1 - Pyrolysis and flammability of phosphorus based flame retardant pressure sensitive adhesives and adhesive tapes
N2 - Pressure-sensitive adhesive tapes are used in a variety of applications such as construction, aircrafts, railway vehicles, and ships, where flame retardancy is essential. Especially in these applications, phosphorus-based flame retardants are often chosen over halogenated ones due to their advantages in terms of toxicity. Although there are pressure-sensitive adhesives with phosphorus flame retardants available on the market, their flame-retardant modes of action and mechanisms are not entirely understood. This research article provides fundamental pyrolysis research of three phosphorus-based flame retardants that exhibit different mechanisms in a pressuresensitive adhesive matrix. The flame-retardants modes of action and mechanisms of a 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO) derivate, an aryl phosphate, and a self-synthesized, covalently bonded DOPO derivate (copolymerized) are investigated. The blended DOPO derivate is volatilized at rather low temperatures while the covalently bonded DOPO derivate decomposes together with the polymer matrix at the same temperature. Both DOPO derivates release PO radicals which are known for their flame inhibition. The aryl phosphate decomposes at higher temperatures, releases small amounts of aryl phosphates into the gas phase, and acts predominantly the condensed phase. The aryl phosphate acts as precursor for phosphoric acid and improves the charring of the pressure sensitive adhesive matrix. All flame retardants enhance the flammability of the adhesives depending on their individual mode of action while the covalently bonded flame retardant additionally improves the mechanical properties at elevated temperatures making it a promising future technology for pressure-sensitive adhesives.
KW - Pyrolysis of flame retardant
KW - Pyrolysis gas chromatography
KW - Mass spectrometry
KW - Phosphorus flame retardant
KW - Decomposition mechanism
KW - Flame retardant pressure sensitive adhesives
KW - Flame retardancy
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-607192
DO - https://doi.org/10.1016/j.jaap.2024.106658
SN - 0165-2370
SN - 1873-250X
VL - 181
SP - 1
EP - 31
PB - Elsevier B.V.
AN - OPUS4-60719
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Krone, David
A1 - Esche, Erik
A1 - Skiborowski, Mirko
A1 - Repke, Jens-Uwe
T1 - Optimization-based process synthesis by phenomena-based building blocks and an MINLP framework featuring structural screening
N2 - An existing approach for optimization-based process synthesis with abstracted phenomena-based building blocks (PBB) is extended by implementing it into a novel MINLP framework with structural screening. Consistency across the multilayer MINLP framework is guaranteed by creating a MathML/XML data model and subsequently exporting the code to the different program parts. The novel framework focuses both on fidelity by implementing thermodynamically sound models and on generality by employing a state-space superstructure that spans a large search space. In order to retain tractability, we insert a structural screening layer which prescreens based on binary decision variables of the superstructure by graph- and rule-based analyses, penalizing non-physical instances without solution of the underlying MINLP. The MINLP framework is successfully applied on two challenging synthesis tasks to determine the separation of the feed streams of benzene and toluene, as well as of n-pentane, n-hexane, and n-heptane utilizing superstructures with two, respectively four PBB.
KW - Process synthesis
KW - Superstructure optimization
KW - Distillation
KW - Mathematical programming
KW - Structural screening
PY - 2025
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-621955
DO - https://doi.org/10.1016/j.compchemeng.2024.108955
VL - 194
SP - 1
EP - 19
PB - Elsevier Ltd.
AN - OPUS4-62195
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Johann, Sergej
A1 - Stürenberg, Jan
A1 - Tandon, Aditya
T1 - Robotergestütztes Bauwerksmonitoring basierend auf eingebetteter Sensorik
N2 - In den letzten Jahrzehnten hat sich das Bauwerksmonitoring (engl. „Structural Health Monitoring“, SHM) zu einer nützlichen Ergänzung routinemäßiger Inspektionen entwickelt. SHM ermöglicht die frühzeitige Erkennung von Schäden an Bauwerken und dadurch die frühe, und somit kostengünstige, Durchführung von Reparatur- und Wartungsarbeiten. Mit dem Aufkommen drahtloser Technologien und Fortschritten in der Informations- und Kommunikationstechnologie werden Bauwerke zunehmend mit drahtlosen Sensorknoten ausgestattet, um für SHM relevante Bauwerksdaten zu erfassen, zu analysieren und zu übertragen. Eine vielversprechende Methode für SHM ist die direkte Einbettung von Sensoren in den Beton. In diesem Beitrag wird ein Sensorsystem zur Einbettung in Beton vorgestellt, das in der Lage ist, die im Beton aufgenommenen Bauwerksdaten auszuwerten. Die Sensoren werden bei Bedarf von vierbeinigen Robotern mittels Radio Frequency Identification (RFID) ausgelesen und mit Energie versorgt, was einen automatisierten und effizienten Prozess ermöglicht. Der prototypische Prozess zur automatischen Erfassung von Bauwerksdaten mit eingebetteter Sensorik und vierbeinigen Robotern wird durch Tests in einer Büroumgebung validiert. Die Ergebnisse der Tests bestätigen die automatische und effiziente Erfassung von Bauwerksdaten, die eine frühzeitige Erkennung von Bauwerksschäden, auch von nicht sichtbaren Schäden, ermöglicht, und eine folgerichtige Weiterentwicklung des
modernen Bauwerksmonitorings repräsentiert.
T2 - 35. Forum Bauinformatik
CY - Hamburg, Germany
DA - 18.09.2024
KW - Radio Frequency Identification (RFID)
KW - Bauwerksmonitoring (SHM)
KW - Eingebettete Sensorik
KW - Vierbeinige Roboter
KW - Autonome Navigation
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-621890
DO - https://doi.org/10.15480/882.13502
SP - 139
EP - 146
AN - OPUS4-62189
LA - deu
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - McMahon, Dino Peter
A1 - Natsopoulou, M. E.
A1 - Doublet, V.
A1 - Fürst, M.
A1 - Weging, S.
A1 - Brown, M. J. F.
A1 - Gogol-Döring, A.
A1 - Paxton, R. J.
T1 - Elevated virulence of an emerging viral genotype as a driver of honeybee loss
N2 - Emerging infectious diseases (EIDs) have contributed significantly to the current biodiversity crisis, leading to widespread epidemics and population loss. Owing to genetic variation in pathogen virulence, a complete understanding of species decline requires the accurate identification and characterization of EIDs. We explore this issue in the Western honeybee, where increasing mortality of populations in the Northern Hemisphere has caused major concern. Specifically, we investigate the importance of genetic identity of the main suspect in mortality, deformed wing virus (DWV), in driving honeybee loss. Using laboratory experiments and a systematic field survey, we demonstrate that an emerging DWV genotype (DWV-B) is more virulent than the established DWV genotype (DWV-A) and is widespread in the landscape. Furthermore, we show in a simple model that colonies infected with DWV-B collapse sooner than colonies infected with DWV-A. We also identify potential for rapid DWV evolution by revealing extensive genome-wide recombination in vivo. The emergence of DWV-B in naive honeybee populations, including via recombination with DWV-A, could be of significant ecological and economic importance. Our findings emphasize that knowledge of pathogen genetic identity and diversity is critical to understanding drivers of species decline.
KW - Virulence
KW - Emerging infectious disease
KW - Pollinator
KW - Decline
PY - 2016
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-368030
DO - https://doi.org/10.1098/rspb.2016.0811
SN - 0962-8452
VL - 283
IS - 1833
SP - Article 0811, 1
EP - 8
AN - OPUS4-36803
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -