TY - JOUR
A1 - Cano Murillo, Natalia
A1 - Ghasem Zadeh Khorasani, Media
A1 - Silbernagl, Dorothee
A1 - Hahn, Marc Benjamin
A1 - Hodoroaba, Vasile-Dan
A1 - Sturm, Heinz
T1 - Nanomechanical study of polycarbonate/boehmite nanoparticles/epoxy ternary composite and their interphases
N2 - Thermoplastic modified thermosets are of great interest especially due to their improved fracture toughness. Comparable enhancements have been achieved by adding different nanofillers including inorganic particles such as nanosized boehmite. Here, we present a nanomechanical study of two composite systems, the first comprising a polycarbonate (PC) layer in contact with epoxy resin (EP) and the second consisting of a PC layer containing boehmite nanoparticles (BNP) which is also in contact with an EP layer. The interaction between PC and EP monomer is tested by in situ Fourier transformed infrared (FT-IR) analysis, from which a reaction induced phase separation of the PC phase is inferred. Both systems are explored by atomic force microscopy (AFM) force spectroscopy. AFM force-distance curves (FDC) show no alteration of the mechanical properties of EP at the interface to PC. However, when a PC phase loaded with BNP is put in contact with an epoxy system during curing, a considerable mechanical improvement exceeding the rule of mixture was detected.
The trend of BNP to agglomerate preferentially around EP dominated regions and the stiffening effect of BNP on EP shown by spatial resolved measurements of Young's modulus, suggest the effective presence of BNP within the EP phase.
KW - Composites
KW - Mechanical properties
KW - Nanoparticles
KW - Thermoplastics
KW - Thermosets
PY - 2021
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-515965
DO - https://doi.org/10.1002/app.50231
SN - 0021-8995
SN - 1097-4628
VL - 138
IS - 12
SP - 1
EP - 11
PB - Wiley
CY - New York, NY
AN - OPUS4-51596
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Sänger, Johanna Christiane
A1 - Pauw, Brian Richard
A1 - Sturm, Heinz
A1 - Günster, Jens
T1 - First time additively manufactured advanced ceramics by using two-photon polymerization for powder processing
N2 - Methods and materials are presented here, which enable the manufacturing of fine structures using a 3D-printing method known as two-photon polymerization (2PP). As traditional photolithography methods for structuring ceramic slurries do not function with 2PP, due to light scattering on ceramic particles, a novel water-based photoresist with high ceramic loading of extremely well dispersed ceramic nano particles was developed. This photoresist is basically a ceramic slurry containing a photocurable agent and a photoinitiator to be crosslinkable with the 780 nm wavelength femtosecond laser light source of the 2PP machine. It is demonstrated that it is possible to gain a highly transparent and low viscous slurry suitable for 2PP processing. This work shows the development of the slurry, first printing results and the post-printing processes required to form three dimensional ceramic microstructures consisting of alumina toughened zirconia (ATZ).
KW - 3D-printing
KW - Two-photon polymerization
KW - 2PP
KW - Ceramic nano particles
KW - Slurry
KW - Alumina toughened zirconia
KW - ATZ
KW - Additive manufacturing
KW - SchwarzP cells
KW - Nano-ceramic-additive-manufacturing photoresin
KW - NanoCAM
PY - 2020
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-517441
DO - https://doi.org/10.1016/j.oceram.2020.100040
VL - 4
SP - 100040
PB - Elsevier Ltd.
AN - OPUS4-51744
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Vogel, Christian
A1 - Hoffmann, Marie
A1 - Krüger, O.
A1 - Murzin, V.
A1 - Caliebe, W.
A1 - Adam, Christian
T1 - Chromium (VI) in phosphorus fertilizers determined with the diffusive gradients in thin-films (DGT) technique
N2 - Phosphorus (P) fertilizers from secondary resources became increasingly important in the last years. However, these novel P-fertilizers can also contain toxic pollutants such as chromium in its hexavalent state (Cr(VI)). This hazardous form of chromium is therefore regulated with low limit values for agricultural products even though the correct determination of Cr(VI) in these fertilizers may be hampered by redox processes, leading to false results. Thus, we applied the novel diffusive gradients in thin-films (DGT) technique for Cr(VI) in fertilizers and compared the results with the standard wet chemical extraction method (German norm DIN EN 15192) and Cr K-edge X-ray Absorption near-edge structure (XANES) spectroscopy. We determined an overall good correlation between the wet chemical extraction and the DGT method. DGT was very sensitive and for most tested materials selective for the analysis of Cr(VI) in P-fertilizers. However, hardly soluble Cr(VI) compounds cannot be detected with the DGT method since only mobile Cr(VI) is analyzed. Furthermore, Cr K-edge XANES spectroscopy showed that the DGT binding layer also adsorbs small amounts of mobile Cr(III) so that Cr(VI) values are overestimated. Since certain types of the P fertilizers contain mobile Cr(III) or partly immobile Cr(VI), it is necessary to optimize the DGT binding layers to avoid aforementioned over- or underestimation. Furthermore, our investigations showed that the Cr K-edge XANES spectroscopy technique is unsuitable to determine small amounts of Cr(VI) in fertilizers (below approx. 1% of Cr(VI) in relation to total Cr).
KW - Phosphorus fertilizer
KW - Sewage sludge ash
KW - Diffusive Gradients in thin films (DGT)
KW - Chemical extraction
KW - XANES spectroscopy
PY - 2020
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-509578
DO - https://doi.org/10.1007/s11356-020-08761-w
SN - 0944-1344
VL - 27
SP - 24320
EP - 24328
PB - Springer
AN - OPUS4-50957
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Cunliffe, A. J.
A1 - Askew, P. D.
A1 - Stephan, Ina
A1 - Iredale, G.
A1 - Cosemans, P.
A1 - Simmons, L. M.
A1 - Verran, J.
A1 - Redfern, J.
T1 - How do we determine the efficacy of an antibacterial surface? A review of standardised antibacterial material testing methods
N2 - Materials that confer antimicrobial activity, be that by innate property, leaching of biocides or design features (e.g., non-adhesive materials) continue to gain popularity to combat the increasing and varied threats from microorganisms, e.g., replacing inert surfaces in hospitals with copper. To understand how efficacious these materials are at controlling microorganisms, data is usually collected via a standardised test method. However, standardised test methods vary, and often the characteristics and methodological choices can make it difficult to infer that any perceived antimicrobial activity demonstrated in the laboratory can be confidently assumed to an end-use setting. This review provides a critical analysis of standardised methodology used in academia and industry, and demonstrates how many key methodological choices (e.g., temperature, humidity/moisture, airflow, surface topography) may impact efficacy assessment, highlighting the need to carefully consider intended antimicrobial end-use of any product.
KW - Antimicrobial materials
KW - Antimicrobial testing
KW - ISO 22196
KW - Antimicrobial surfaces
KW - Antibacterial coatings
PY - 2021
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-532138
DO - https://doi.org/10.3390/antibiotics10091069
SN - 2079-6382
VL - 10
IS - 9
SP - 1
EP - 14
PB - MDPI
CY - Basel
AN - OPUS4-53213
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Herzel, Hannes
A1 - Aydin, Zeynep
A1 - Adam, Christian
T1 - Crystalline phase analysis and phosphorus availability after thermochemical treatment of sewage sludge ash with sodium and potassium sulfates for fertilizer production
N2 - Phosphorus rich sewage sludge ash is a promising source to produce phosphorus recycling fertilizer. However, the low plant availability of phosphorus in these ashes makes a treatment necessary. A thermochemical treatment (800–1000 °C) with alkali additives transforms poorly plant available phosphorus phases to highly plant available calcium alkali Phosphates (Ca,Mg)(Na,K)PO4. In this study, we investigate the use of K2SO4 as additive to produce a phosphorus potassium fertilizer in laboratory-scale experiments (crucible). Pure K2SO4 is not suitable as high reaction temperatures are required due to the high melting point of K2SO4.
To overcome this barrier, we carried out series of experiments with mixtures of K2SO4 and Na2SO4 resulting in a lower economically feasible reaction temperature (900–1000 °C). In this way, the produced phosphorus potassium fertilizers (8.4 wt.% K, 7.6 wt.% P) was highly plant available for phosphorus indicated by complete extractable phosphorus in neutral ammonium citrate solution. The added potassium is, in contrast to sodium, preferably incorporated into silicates instead of phosphorus phases. Thus, the highly extractable phase (Ca,Mg)(Na,K)PO4 in the thermochemical products contain less potassium than expected. This preferred incorporation is confirmed by a pilot-scale trial (rotary kiln) and thermodynamic calculation.
KW - Phosphorus recovery
KW - Recycling fertilizer
KW - Calcium alkali phosphate
KW - Silicate
PY - 2021
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-536276
DO - https://doi.org/10.1007/s10163-021-01288-3
SN - 1611-8227
IS - 23
SP - 2242
EP - 2254
PB - Springer
AN - OPUS4-53627
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Cano Murillo, Natalia
A1 - Ghasem Zadeh Khorasani, Media
A1 - Silbernagl, Dorothee
A1 - Emamverdi, Farnaz
A1 - Cacua, K.
A1 - Hodoroaba, Vasile-Dan
A1 - Sturm, Heinz
T1 - Carrier Fibers for the Safe Dosage of Nanoparticles in Nanocomposites: Nanomechanical and Thermomechanical Study on Polycarbonate/Boehmite Electrospun Fibers Embedded in Epoxy Resin
N2 - The reinforcing effect of boehmite nanoparticles (BNP) in epoxy resins for fiber composite lightweight construction is related to the formation of a soft but bound interphase between filler and polymer. The interphase is able to dissipate crack propagation energy and consequently increases the fracture toughness of the epoxy resin. Usually, the nanoparticles are dispersed in the resin and then mixed with the hardener to form an applicable mixture to impregnate the fibers. If one wishes to locally increase the fracture toughness at particularly stressed positions of the fiber-reinforced polymer composites (FRPC), this could be done by spraying nanoparticles from a suspension. However, this would entail high costs for removing the nanoparticles from the ambient air. We propose that a fiber fleece containing bound nanoparticles be inserted at exposed locations. For the present proof-of-concept study, an electrospun polycarbonate nonwoven and taurine modified BNP are proposed. After fabrication of suitable PC/EP/BNP composites, the thermomechanical properties were tested by dynamic mechanical analysis (DMA). Comparatively, the local nanomechanical properties such as stiffness and elastic modulus were determined by atomic force microscopy (AFM). An additional investigation of the distribution of the nanoparticles in the epoxy matrix, which is a prerequisite for an effective nanocomposite, is carried out by scanning electron microscopy in transmission mode (TSEM). From the results it can be concluded that the concept of carrier fibers for nanoparticles is viable.
KW - Advanced materials
KW - Electrospun nanocomposite fiber
KW - Nanomechanical charecteisation
KW - Nanosafety
KW - Epoxy nanocomposites
PY - 2021
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-528265
DO - https://doi.org/10.3390/nano11061591
VL - 11
IS - 6
SP - 1591
PB - MDPI
CY - CH - 4020 Basel, Switzerland
AN - OPUS4-52826
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Raniro, H.R.
A1 - Soares, T.de M.
A1 - Adam, Christian
A1 - Pavinato, P.S.
T1 - Waste-derived fertilizers can increase phosphorus uptake by sugarcane and availability in a tropical soil
N2 - The use of highly water-soluble phosphorus (P) fertilizers can lead to P fixation in the soil, reducing fertilization efficiency. Waste-derived, low water-solubility sources can potentially increase sugarcane’s P uptake compared to triple superphosphate by reducing adsorption to the soil.
Aims:We aimed to test struvite, hazenite, and AshDec® for their agronomic potential as recycled fertilizers for sugarcane production in a typical tropical soil.We hypothesize that these sources can reduce P fixation in the soil, increasing its availability and sugarcane’s absorption.
Methods: In a greenhouse pot experiment, two consecutive sugarcane cycles, 90 days each, were conducted in a Ferralsol. The recovered sources struvite, hazenite, AshDec®, and the conventional triple superphosphate were mixed in the soil in three P doses (30, 60, and 90 mg kg–1), aside a control (nil-P). At both harvests, sugarcane number of sprouts, plant height, stem diameter, dry mass yield, shoot phosphorus, and soil P fractionation were investigated.
Results: At 90 days, struvite and hazenite performed better for dry mass yield (70.7 and 68.3 g pot–1, respectively) than AshDec® and triple superphosphate (59.8 and 57.4 g pot–1, respectively) and for shoot P, with 98.1, 91.6, 75.6, and 66.3 mg pot–1, respectively. At 180 days, struvite outperformed all treatments for dry mass yield (95.3 g pot–1) and AshDec® (75.5 mg pot–1) for shoot P. Struvite was 38% and hazenite 21% more efficient than triple superphosphate in P uptake, while AshDec® was 6% less efficient. Soil had higher labile P under struvite, hazenite, and AshDec® than triple superphosphate by the end of the first cycle, while only the later increased nonlabile P by the end of the experiment (180 days).
Conclusions:Waste-derived P sources were more efficient in supplying P for sugarcane and delivering labile P in 180 days than triple superphosphate.
KW - AshDec
KW - Hazenite
KW - P-efficiency
KW - Recycled sources
KW - Struvite
PY - 2022
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-544216
DO - https://doi.org/10.1002/jpln.202100410
SN - 1436-8730
SP - 1
EP - 12
PB - Wiley-VCH GmbH
AN - OPUS4-54421
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Dudziak, Mateusz
A1 - Topolniak, Ievgeniia
A1 - Silbernagl, Dorothee
A1 - Altmann, Korinna
A1 - Sturm, Heinz
T1 - Long-time behavior of surface properties of microstructures fabricated by multiphoton lithography
N2 - The multiphoton lithography (MPL) technique represents the future of 3D microprinting, enabling the production of complex microscale objects with high precision. Although the MPL fabrication parameters are widely evaluated and discussed, not much attention has been given to the microscopic properties of 3D objects with respect to their surface properties and time-dependent stability. These properties are of crucial importance when it comes to the safe and durable use of these structures in biomedical applications. In this work, we investigate the surface properties of the MPL-produced SZ2080 polymeric microstructures with regard to the physical aging processes during the post-production stage. The influence of aging on the polymeric microstructures was investigated by means of Atomic Force Microscopy (AFM) and X-ray Photoelectron Spectroscopy (XPS). As a result, a time-dependent change in Young’s Modulus, plastic deformation, and adhesion and their correlation to the development in chemical composition of the surface of MPL-microstructures are evaluated. The results presented here are valuable for the application of MPL-fabricated 3D objects in general, but especially in medical technology as they give detailed information of the physical and chemical time-dependent dynamic behavior of MPL-printed surfaces and thus their suitability and performance in biological systems.
KW - Multiphoton lithography
KW - Additive manufacturing
KW - Microfabrication
KW - SZ2080 negative photo-resist
KW - Young´s modulus
KW - Aging
KW - Surface properties
KW - X-ray photoelectron spectroscopy
KW - Atomic force microscopy
KW - Force-distance-curve
PY - 2021
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-542166
DO - https://doi.org/10.3390/nano11123285
SN - 2079-4991
VL - 11
IS - 12
SP - 1
EP - 12
PB - MDPI
CY - Basel
AN - OPUS4-54216
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Schraut, Katharina
A1 - Kargl, F.
A1 - Adam, Christian
A1 - Ivashko, O.
T1 - In situ synchrotron XRD measurements during solidification of a melt in the CaO–SiO2 system using an aerodynamic levitation system
N2 - Phase formation and evolution was investigated in the CaO–SiO2 system in the range of 70–80 mol% CaO. The samples were container-less processed in an aerodynamic levitation system and crystallization was followed in situ by synchrotron x-ray diffraction at the beamline P21.1 at the German electron synchrotron (DESY). Modification changes of di- and tricalcium silicate were observed and occurred at lower temperatures than under equilibrium conditions. Despite deep sample undercooling, no metastable phase formation was observed within the measurement timescale of 1 s. For the given cooling rates ranging from 300 K s−1 to about 1 K s−1, no decomposition of tricalcium silicate was observed. No differences in phase evolution were observed between reducing and oxidizing conditions imposed by the levitation gas (Ar and Ar + O2). We demonstrate that this setup has great potential to follow crystallization in refractory oxide liquids in situ. For sub-second primary phase formation faster detection and for polymorph detection adjustments in resolution have to be implemented.
KW - Aerodynamic levitation
KW - Calcium silicate
KW - Phase formation
KW - Oxide melts
KW - In situ synchrotron x-ray diffraction
PY - 2021
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-526952
DO - https://doi.org/10.1088/1361-648X/abf7e1
VL - 33
IS - 26
SP - 264003 (12pp)
PB - IOP Publishing
AN - OPUS4-52695
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Usmani, S.
A1 - Voss, L.
A1 - Stephan, Ina
A1 - Hübert, Thomas
A1 - Kemnitz, E.
T1 - Improved Durability of Wood Treated with Nano Metal Fluorides against Brown-Rot and White-Rot Fungi
N2 - Low-water soluble metal fluorides such as magnesium fluoride (MgF2) and calcium Fluoride (CaF2) were evaluated for decay protection of wood. Initially, the biocidal efficacy of nano metal fluorides (NMFs) against wood destroying fungi was assessed with an in-vitro agar test. The results from the test showed that agar medium containing MgF2 and CaF2 was more efficient in preventing fungal decay than stand-alone MgF2 or CaF2. These metal fluorides, in their nanoscopic form synthesized using fluorolytic sol-gel synthesis, were introduced into the sapwood of Scots pine and beech wood and then subjected to accelerated ageing by leaching (EN 84). MAS 19F NMR and X-ray micro CT images showed that metal fluorides were present in treated wood, unleached and leached. Decay resistance of Scots pine and beech wood treated with NMFs was tested against Wood destroying fungi Rhodonia placenta and Trametes versicolor in accordance with EN 113. Results revealed that mass losses were reduced to below 3% in wood treated with the combination of MgF2 and CaF2.
It is concluded that NMFs provide full protection to wood even after it has been leached and can be used as wood preservatives in outdoor environments.
KW - Nanoparticles
KW - Fluoride
KW - Wood protection
KW - Fluorolytic sol-gel synthesis
KW - Brown-rot fungi
KW - White-rot fungi
KW - Basidiomycetes
PY - 2022
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-543877
DO - https://doi.org/10.3390/app12031727
VL - 12
IS - 3
SP - 1
EP - 11
PB - MDPI
AN - OPUS4-54387
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Waniek, Tassilo
A1 - Braun, U.
A1 - Silbernagl, Dorothee
A1 - Sturm, Heinz
T1 - The impact of water released from boehmite nanoparticles during curing in epoxy-based nanocomposites
N2 - The enhancing effect on mechanical properties of boehmite (γ-AlOOH) nanoparticles (BNP) in epoxy-based nanocomposites on the macroscopic scale encouraged recent research to investigate the micro- and nanoscopic properties. Several studies presented different aspects relatable to an alteration of the epoxy polymer network formation by the BNP with need for further experiments to identify the mode of action.
With FTIR-spectroscopic methods this study identifies interactions of the BNP with the epoxy polymer matrix during the curing process as well as in the cured nanocomposite. The data reveals that not the BNP themselves, but the water released from them strongly influences the curing process by hydrolysis of the anhydride hardener or protonation of the amine accelerator. The changes of the curing processes are discussed in detail.
The changes of the curing processes enable new explanation for the changed material properties by BNP discussed in recent research like a lowered glass transition temperature region (Tg) and an interphase formation.
KW - Spectroscopy
KW - Aluminium oxide hydroxide
KW - Glass transition temperature
KW - Material chemistry
KW - Nanocomposites
KW - Structure-property relationship
PY - 2021
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-527202
DO - https://doi.org/10.1002/app.51006
VL - 138
IS - 39
SP - 51006
PB - Wiley Periodicals LLC
CY - Hoboken
AN - OPUS4-52720
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Fritzsche, Sven
A1 - Topolniak, Ievgeniia
A1 - Weise, Matthias
A1 - Sturm, Heinz
T1 - Shape deviations of DLW microstructures in dependency of fabrication parameters
N2 - Deep understanding of the effects associated with fabrication parameters and their influence on the resulting structures shape is essential for the further development of direct laser writing (DLW). In particular, it is critical for development of reference materials, where structure parameters are precisely fabricated and should be reproduced with use of DLW technology. In this study we investigated the effect of various fabrication and preparation parameters on the structural precision of interest for reference materials. A well-studied photo-curable system, SZ2080 negative photo-resist with 1 wt.% Michler's ketone (Bis) photo-initiator, was investigated in this work. The correlation between applied laser power, laser velocity, fabrication direction on the deviations in the structure shape were observed by means of white light interferometry microscopy. Moreover, influence of slicing and hatching distances as well as prebake time were studied as function of sample shape. Deviations in the structure form between the theoretically expected and the one detected after DLW fabrication were observed in the range up to 15%. The observed shape discrepancies show the essential importance of fine-tuning the fabrication parameter for reference structure production.
KW - Direct laser writing
KW - Fabrication parameters
KW - Structural precision
KW - SZ2080 negative photo-resist
KW - White light interferometry microscopy
PY - 2021
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-535906
DO - https://doi.org/10.1088/1361-6439/ac2a14
VL - 31
IS - 12
SP - 1
EP - 8
PB - IOP Science
AN - OPUS4-53590
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Zou, T.
A1 - Nonappa, N.
A1 - Khavani, M.
A1 - Vuorte, M.
A1 - Penttilä, P.
A1 - Zitting, A.
A1 - Valle-Delgado, J. J.
A1 - Elert, Anna Maria
A1 - Silbernagl, Dorothee
A1 - Balakshin, M.
A1 - Sammalkorpi, M.
A1 - Österberg, M.
T1 - Experimental and Simulation Study of the Solvent Effects on the Intrinsic Properties of Spherical Lignin Nanoparticles
N2 - Spherical lignin nanoparticles (LNPs) fabricated via nanoprecipitation of dissolved lignin are among the most attractive biomass-derived nanomaterials. Despite various studies exploring the methods to improve the uniformity of LNPs or seeking more application opportunities for LNPs, little attention has been given to the fundamental aspects of the solvent effects on the intrinsic properties of LNPs. In this study, we employed a variety of experimental techniques and molecular dynamics (MD) simulations to investigate the solvent effects on the intrinsic properties of LNPs. The LNPs were prepared from softwood Kraft lignin (SKL) using the binary solvents of aqueous acetone or aqueous tetrahydrofuran (THF) via nanoprecipitation. The internal morphology, porosity, and mechanical properties of the LNPs were analyzed with electron tomography (ET), small-angle X-ray scattering (SAXS), atomic force microscopy (AFM), and intermodulation AFM (ImAFM). We found that aqueous acetone resulted in smaller LNPs with higher uniformity compared to aqueous THF, mainly ascribing to stronger solvent−lignin interactions as suggested by MD simulation results and confirmed with aqueous 1,4-dioxane (DXN) and aqueous dimethyl sulfoxide (DMSO).
More importantly, we report that both LNPs were compact particles with relatively homogeneous density distribution and very low porosity in the internal structure. The stiffness of the particles was independent of the size, and the Young’s modulus was in the range of 0.3−4 GPa. Overall, the fundamental understandings of LNPs gained in this study are essential for the design of LNPs with optimal performance in applications.
KW - Lignin
KW - Electron tomography
KW - Intermodulation AFM
KW - Modulus
KW - SAXS
PY - 2021
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-546948
DO - https://doi.org/10.1021/acs.jpcb.1c05319
SN - 1520-5207
VL - 125
IS - 44
SP - 12315
EP - 12328
PB - ACS
AN - OPUS4-54694
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Sichler, Theresa Constanze
A1 - Adam, Christian
A1 - Barjenbruch, M.
A1 - Montag, D.
A1 - Mauch, Tatjana
A1 - Sommerfeld, Thomas
A1 - Ehm, J.H.
T1 - Variation of the element composition of municipal sewage sludges in the context of new regulations on phosphorus recovery in Germany
N2 - Phosphorus (P) recovery is obligatory for all sewage sludges with more than 20 g P/kg dry matter (DM) from 2029 in Germany. Nine wastewater treatment plants (WWTPs) were chosen to investigate variations of phosphorus contents and other parameters in sewage sludge over the year. Monthly sewage sludge samples from each WWTP were analyzed for phosphorus and other matrix elements (C, N, H, Ca, Fe, Al, etc.), for several trace elements (As, Cr, Mo, Ni, Pb, Sn) and loss of ignition. Among the nine WWTPs, there are four which have phosphorus contents both above and below the recovery limit of 20 g/kg DM along the year. Considering the average phosphorus content over the year, only one of them is below the limit. Compared to other matrix elements and parameters, phosphorus fuctuations are low with an average of 7% over all nine WWTPs. In total, only hydrogen and carbon are more constant in the sludge.
In several WWTPs with chemical phosphorus elimination, phosphorus fuctuations showed similar courses like iron and/or aluminum. WWTPs with chamber flter presses rather showed dilution efects of calcium dosage. As result of this study, monthly phosphorus measurement is highly recommended to determine whether a WWTP is below the
20 g/kg DM limit.
KW - Sewage sludge
KW - Phosphorus recovery
KW - Wastewater
KW - Phosphorus elimination
PY - 2022
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-557499
DO - https://doi.org/10.1186/s12302-022-00658-4
SN - 2190-4707
VL - 34
IS - 1
SP - 1
EP - 12
PB - Springer Nature
CY - Berlin
AN - OPUS4-55749
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Sichler, Theresa Constanze
A1 - Adam, Christian
A1 - Becker, Roland
A1 - Sauer, Andreas
A1 - Ostermann, Markus
A1 - Barjenbruch, M.
T1 - Phosphorus determination in sewage sludge: comparison of different aqua regia digestion methods and ICP-OES, ICP-MS and photometric determination
N2 - Phosphorus recycling from sewage sludge will be obligatory in Germany from 2029. Phosphorus content determination in sewage sludge is crucial to assess the prescribed recycling rates. Currently, German law regards sample preparation using aqua regia digestion in a microwave or under reflux conditions as well as instrumental phosphorus determination by ICP-OES, ICP-MS, or photometric determination with ammonium molybdate as equivalent. However, it is questionable whether these methods are indeed equivalent regarding phosphorus quantification in sludges near the limit of 20 g/kg for mandatory recycling. To answer this question, 15 sewage sludges of 11 different wastewater treatment plants were investigated with all permitted method (digestion and measurement) combinations. Moreover, one sewage sludge was also examined in an interlaboratory comparison (ILC) with 28 participants. This study shows that the above-mentioned methods differ in some cases significantly but across all method combinations and sludges, phosphorus recovery was between 80 and 121% after normalization to the grand mean (average of 15 sludges between 85 and 111%). The ILC and the examination of 15 sludges produced largely similar results. There is a tendency to higher phosphorus recovery after microwave digestion compared to reflux digestion and ICP-OES measurements determine higher phosphorus contents than ICP-MS and photometric phosphorus determination. As a result, the authors recommend ICP-OES determination of phosphorus in sewage sludge after microwave digestion.
KW - Sewage sludge
KW - ICP-OES
KW - Phosphous recovery
KW - ICP-MS
KW - Photometric P determination
KW - Interlaboratory comparison
PY - 2022
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-558869
DO - https://doi.org/10.1186/s12302-022-00677-1
VL - 34
IS - 99
SP - 1
EP - 14
PB - Springer
AN - OPUS4-55886
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Dombinov, V.
A1 - Herzel, Hannes
A1 - Meiller, M.
A1 - Müller, F.
A1 - Willbold, S.
A1 - Zang, J. W.
A1 - da Fonseca-Zang, W. A.
A1 - Adam, Christian
A1 - Klose, H.
A1 - Poorter, H.
A1 - Jablonowski, N. D.
A1 - Schrey, S. D.
T1 - Sugarcane bagasse ash as fertilizer for soybeans: Effects of added residues on ash composition, mineralogy, phosphorus extractability and plant availability
N2 - Sugarcane bagasse is commonly combusted to generate energy. Unfortunately, recycling strategies rarely consider the resulting ash as a potential fertilizer. To evaluate this recycling strategy for a sustainable circular economy, we characterized bagasse ash as a fertilizer and measured the effects of co-gasification and co-combustion of bagasse with either chicken manure or sewage sludge: on the phosphorus (P) mass fraction, P-extractability, and mineral P phases. Furthermore, we investigated the ashes as fertilizer for soybeans under greenhouse conditions. All methods in combination are reliable indicators helping to assess and predict P availability from ashes to soybeans. The fertilizer efficiency of pure bagasse ash increased with the ash amount supplied to the substrate. Nevertheless, it was not as effective as fertilization with triple-superphosphate and K2SO4, which we attributed to lower P availability. Co-gasification and co-combustion increased the P mass fraction in all bagasse-based ashes, but its extractability and availability to soybeans increased only when co-processed with chicken manure, because it enabled the formation of readily available Ca-alkali phosphates. Therefore, we recommend co-combusting biomass with alkali-rich residues to increase the availability of P from the ash to plants.
KW - Combustion and gasification
KW - Phosphate extractability and availability
KW - X-ray diffraction (XRD)
PY - 2022
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-567632
DO - https://doi.org/10.3389/fpls.2022.1041924
SN - 1664-462X
VL - 13
SP - 1
EP - 13
PB - Frontiers Media
CY - Lausanne
AN - OPUS4-56763
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Lackmann, C.
A1 - Velki, M.
A1 - Šimić, A.
A1 - Müller, Axel
A1 - Braun, U.
A1 - Ečimović, S.
A1 - Hollert, H.
T1 - Two types of microplastics (polystyrene-HBCD and car tire abrasion) affect oxidative stress-related biomarkers in earthworm Eisenia andrei in a time-dependent manner
N2 - Microplastics are small plastic fragments that are widely distributed in marine and terrestrial environments. While the soil ecosystem represents a large reservoir for plastic, research so far has focused mainly on the impact on aquatic ecosystems and there is a lack of information on the potentially adverse effects of microplastics on soil biota. Earthworms are key organisms of the soil ecosystem and are due to their crucial role in soil quality and fertility a suitable and popular model organism in soil ecotoxicology.
Therefore, the aim of this study was to gain insight into the effects of environmentally relevant concentrations of microplastics on the earthworm Eisenia andrei on multiple levels of biological organization after different exposure periods. Earthworms were exposed to two types of microplastics: (1) polystyrene-HBCD and (2) car tire abrasion in natural soil for 2, 7, 14 and 28 d. Acute and chronic toxicity and all subcellular investigations were conducted for all exposure times, avoidance behavior assessed after 48 h and reproduction after 28 d. Subcellular endpoints included enzymatic biomarker responses, namely, carboxylesterase, glutathione peroxidase, acetylcholinesterase, glutathione reductase, glutathione S-transferase and catalase activities, as well as fluorescence-based measurements of oxidative stress-related markers and multixenobiotic resistance activity. Multiple biomarkers showed significant changes in activity, but a recovery of most enzymatic activities could be observed after 28 d. Overall, only minor effects could be observed on a subcellular level, showing that in this exposure scenario with environmentally relevant concentrations based on German pollution levels the threat to soil biota is minimal. However, in areas with higher concentrations of microplastics in the environment, these results can be interpreted as an early warning signal for more adverse effects. In conclusion, these findings provide new insights regarding the ecotoxicological effects of environmentally relevant concentrations of microplastics on soil organisms.
KW - Microplastics
KW - Earthworms
KW - Toxicity
KW - Biomarker
KW - oxidative stress
PY - 2022
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-545423
DO - https://doi.org/10.1016/j.envint.2022.107190
VL - 163
SP - 1
EP - 12
PB - Elsevier Ltd.
AN - OPUS4-54542
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Machado Ferreira de Araujo, F.
A1 - Duarte-Ruiz, D.
A1 - Saßnick, H.-D.
A1 - Gentzmann, Marie C.
A1 - Huthwelker, T.
A1 - Cocchi, C.
T1 - Electronic Structure and Core Spectroscopy of Scandium Fluoride Polymorphs
N2 - Microscopic knowledge of the structural, energetic, and electronic properties of scandium fluoride is still incomplete despite the relevance of this material as an intermediate for the manufacturing of Al−Sc alloys. In a work based on first-principles calculations and X-ray spectroscopy, we assess the stability and electronic structure of six computationally predicted ScF3 polymorphs, two of which correspond to experimentally resolved single-crystal phases. In the theoretical analysis based on density functional theory (DFT), we identify similarities among the polymorphs based on their formation energies, chargedensity distribution, and electronic properties (band gaps and density of states). We find striking analogies between the results obtained for the ow- and high-temperature phases of the material, indirectly confirming that the transition occurring between them mainly consists of a rigid rotation of the lattice. With this knowledge, we examine the X-ray absorption spectra from the Sc and F K-edge contrasting firstprinciples results obtained from the solution of the Bethe−Salpeter equation on top of all-electron DFT with high-energy-resolution fluorescence detection measurements. Analysis of the computational results sheds light on the electronic origin of the absorption maxima and provides information on the prominent excitonic effects that characterize all spectra. A comparison with measurements confirms that the sample is mainly composed of the high- and low-temperature polymorphs of ScF3. However, some fine details in the experimental results suggest that the probed powder sample may contain defects and/or residual traces of metastable polymorphs.
KW - Scandium
KW - X-ray spectroscopy
PY - 2023
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-570727
DO - https://doi.org/10.1021/acs.inorgchem.2c04357
SN - 0020-1669
VL - 62
IS - 10
SP - 4238
EP - 4247
PB - ACS Publications
CY - Washington DC
AN - OPUS4-57072
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Sänger, Johanna Christiane
A1 - Pauw, Brian Richard
A1 - Riechers, Birte
A1 - Zocca, Andrea
A1 - Rosalie, Julian
A1 - Maaß, Robert
A1 - Sturm, Heinz
A1 - Günster, Jens
T1 - Entering a new dimension in powder processing for advanced ceramics shaping
N2 - Filigree structures can be manufactured via two-photon-polymerization (2PP) operating in the regime of non-linear light absorption. For the first time it is possible to apply this technique to the powder processing of ceramic structures with a feature size in the range of the critical defect size responsible for brittle fracture and, thus, affecting fracture toughness of high-performance ceramics. In this way, tailoring of advanced properties can be achieved already in the shaping process. Traditionally, 2PP relies on transparent polymerizable resins, which is diametrically opposed to the usually completely opaque ceramic resins and slurries. Here we present a transparent and photocurable suspension of nanoparticles (resin) with very high mass fractions of yttria-stabilized zirconia particles (YSZ). Due to the extremely well dispersed nanoparticles, scattering of light can be effectively suppressed at the process-relevant wavelength of 800 nm. Sintered ceramic structures with a resolution of down to 500 nm were obtained. Even at reduced densities of 1 to 4 g/cm³, the resulting compressive strength with 4,5 GPa is equivalent or even exceeding bulk monolithic yttria stabilized zirconia. A ceramic metamaterial is born, where the mechanical properties of yttria stabilized zirconia are altered by changing geometrical parameters and gives access to a new class of ceramic materials.
KW - Two-photon-polymerization
KW - Ceramics
KW - Powder processing
KW - Transparency
KW - Meta material
KW - Yttria stabilized zirconia
PY - 2022
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-564598
DO - https://doi.org/10.1002/adma.202208653
SN - 1521-4095
SP - 1
EP - 8
PB - Wiley-VCH
CY - Weinheim
AN - OPUS4-56459
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Silbernagl, Dorothee
A1 - Sturm, Heinz
A1 - Plajer, A. J.
T1 - Thioanhydride/isothiocyanate/epoxide ring-opening terpolymerisation: sequence selective enchainment of monomer mixtures and switchable catalysis
N2 - We report a new sequence selective terpolymerisation in which three monomers (butylene oxide (BO) A, PhNCS B and phtalic thioanhydride (PTA) C) are selectively enchained into an (ABA′C)n sequence. PTA/PhNCS/BO ring-opening terpolymerisation ROTERP can be coupled with CS2 ROTERP to generate tetrapolymers and with εDL ROP in switchable catalysis for blockpolymer synthesis.
KW - Blockcopolymer
KW - 1H-NMR
KW - TGA
KW - DSC
KW - AFM
PY - 2022
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-552339
DO - https://doi.org/10.1039/d2py00629d
SP - 1
EP - 5
PB - Royal Society of Chemistry
CY - Cambridge, UK
AN - OPUS4-55233
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Teixeira, M.M.
A1 - Moreno, L.F.
A1 - Stielow, B.J.
A1 - Muszewska, A.
A1 - Hainaut, M.
A1 - Gonzaga, L.
A1 - Abouelleil, A.
A1 - Patan, J.S.L.
A1 - Priest, M.
A1 - Souza, R.
A1 - Ferreira, K.S.
A1 - Zeng, Q.
A1 - da Cunha, M.M.L.
A1 - Gladki, A.
A1 - Barker, B.
A1 - Vicente, V.A.
A1 - de Souza, E.M.
A1 - Almeida, S.
A1 - Henrissat, B.
A1 - Vasconelos, A.T.R.
A1 - Deng, S.
A1 - Vogelmayr, H.
A1 - Moussa, T.A.A.
A1 - Gorbushina, Anna
A1 - Felipe, M.S.S.
A1 - Cuomo, C.A.
A1 - de Hoog, G.S.
T1 - Exploring the genomic diversity of black yeasts and relatives (Chaetothyriales, Ascomycota)
N2 - The order Chaetothyriales (Pezizomycotina, Ascomycetes) harbours obligatorily melanised fungi and includes numerous etiologic agents of chromoblastomycosis, phaeohyphomycosis and other diseases of vertebrate hosts. Diseases range from mild cutaneous to fatal cerebral or disseminated infections and affect humans and cold-blooded animals globally. In addition, Chaetothyriales comprise species with aquatic, rock-inhabiting, ant-associated, and mycoparasitic life-styles, as well as species that tolerate toxic compounds, suggesting a high degree of versatile extremotolerance. To understand their biology and divergent niche occupation, we sequenced and annotated a set of 23 genomes of main the human opportunists within the Chaetothyriales as well as related environmental species. Our analyses included fungi with diverse life-styles, namely opportunistic pathogens and closely related saprobes, to identify genomic adaptations related to pathogenesis. Furthermore, ecological preferences of Chaetothyriales were analysed, in conjuncture with the order-level phylogeny based on conserved ribosomal genes. General characteristics, phylogenomic relationships, transposable elements, sex-related genes, protein family evolution, genes related to protein degradation (MEROPS), carbohydrate-active enzymes (CAZymes), melanin synthesis and secondary metabolism were investigated and compared between species. Genome assemblies varied from 25.81 Mb (Capronia coronata) to 43.03 Mb (Cladophialophora immunda). The bantiana-clade contained the highest number of predicted genes (12 817 on average) as well as larger genomes. We found a low content of mobile elements, with DNA transposons from Tc1/Mariner superfamily being the most abundant across analysed species. Additionally, we identified a reduction of carbohydrate degrading enzymes, specifically many of the Glycosyl Hydrolase (GH) class, while most of the Pectin Lyase (PL) genes were lost in etiological agents of chromoblastomycosis and phaeohyphomycosis. An expansion was found in protein degrading peptidase enzyme families S12 (serine-type D-Ala-D-Ala carboxypeptidases) and M38 (isoaspartyl dipeptidases). Based on genomic information, a wide range of abilities of melanin biosynthesis was revealed; genes related to metabolically distinct DHN, DOPA and pyomelanin pathways were identified. The MAT (MAting Type) locus and other sexrelated genes were recognized in all 23 black fungi. Members of the asexual genera Fonsecaea and Cladophialophora appear to be heterothallic with a single copy of either MAT-1-1 or MAT-1-2 in each individual. All Capronia species are homothallic as both MAT1-1 and MAT1-2 genes were found in each single genome. The genomic synteny of the MAT-locus flanking genes (SLA2-APN2-COX13) is not conserved in black fungi as is commonly observed in Eurotiomycetes, indicating a unique genomic context for MAT in those species. The heterokaryon (het) genes expansion associated with the low selective pressure at the MAT-locus suggests that a parasexual cycle may play an important role in generating diversity among those fungi.
KW - Black yeast
KW - Comparative genomics
KW - Chaetothyriales
KW - Ecology
KW - Evolution
KW - Herpotrichiellaceae
KW - Phylogeny
PY - 2017
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-408720
DO - https://doi.org/10.1016/j.simyco.2017.01.001
SN - 1872-9797
VL - 86
IS - 1
SP - 1
EP - 28
PB - Elsevier
CY - Amsterdam
AN - OPUS4-40872
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Wurzler, Nina
A1 - Schutter, Jan David
A1 - Wagner, R.
A1 - Dimper, Matthias
A1 - Lützenkirchen-Hecht, D.
A1 - Özcan Sandikcioglu, Özlem
T1 - Abundance of Fe(III) during cultivation affects the microbiologically influenced corrosion (MIC) behaviour of iron reducing bacteria Shewanella putrefaciens
N2 - The effect of the presence of Fe(III) during the cultivation on the electrochemical activity and corrosion behaviour of dissimilatory iron reducing bacteria Shewanella putrefaciens was studied by means of ex situ and in situ X-ray absorption near-edge spectroscopy (XANES). Stainless steel AISI 304 and thin iron films were studied as substrates. XANES analysis indicated an accelerated iron dissolution and growth of an oxide/hydroxide film for the culture grown with Fe(III) in comparison to the culture grown in absence of Fe(III). Electrochemical Analysis indicated that the biofilm resulted in acceleration of the general corrosion but provides protection against local corrosion.
KW - Stainless Steel
KW - XANES
KW - Iron
KW - Cyclic Voltammetry
KW - Microbiological Corrosion
PY - 2020
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-513788
DO - https://doi.org/10.1016/j.corsci.2020.108855
VL - 174
SP - 108855
PB - Elsevier Ltd.
AN - OPUS4-51378
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Wurzler, Nina
A1 - Schütter, Jan David
A1 - Wagner, R.
A1 - Dimper, Matthias
A1 - Hodoroaba, Vasile-Dan
A1 - Lützenkirchen-Hecht, D.
A1 - Özcan Sandikcioglu, Özlem
T1 - Preconditioning of AISI 304 stainless steel surfaces in the presence of flavins—Part II: Effect on biofilm formation and microbially influenced corrosion processes
N2 - Biofilm formation and microbially influenced corrosion of the iron-reducing microorganism Shewanella putrefaciens were investigated on stainless steel surfaces preconditioned in the absence and presence of flavin molecules by means of XANES (X-ray absorption near-edge structure) analysis and electrochemical methods. The results indicate that biofilm formation was promoted on samples preconditioned in electrolytes containing minute amounts of flavins. On the basis of the XANES results, the corrosion processes are controlled by the iron-rich outer layer of the passive film. Biofilm formation resulted in a cathodic shift of the open circuit potential and a protective effect in terms of pitting corrosion. The samples preconditioned in the absence of flavins have shown delayed pitting and the samples preconditioned in the presence of flavins did not show any pitting in a window of −0.3- to +0.0-V overpotential in the bacterial medium. The results indicate that changes in the passive film chemistry induced by the presence of minute amounts of flavins during a mild anodic polarization can change the susceptibility of stainless steel surfaces to microbially influenced corrosion.
KW - Biofilms
KW - XANES
KW - Microbially influenced corrosion (MIC)
PY - 2021
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-528130
DO - https://doi.org/10.1002/maco.202012192
VL - 72
IS - 6
SP - 983
EP - 994
PB - Wiley
AN - OPUS4-52813
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Noack-Schönmann, Steffi
A1 - Bus, T.
A1 - Banasiak, Ronald
A1 - Knabe, Nicole
A1 - Broughton, William J.
A1 - Dulk-Ras, H.D.
A1 - Hooykaas, P.J.J.
A1 - Gorbushina, Anna
T1 - Genetic transformation of Knufia petricola A95 - a model organism for biofilm-material interactions
N2 - We established a protoplast-based system to transfer DNA to Knufia petricola strain A95, a melanised rock-inhabiting microcolonial fungus that is also a component of a model sub-aerial biofilm (SAB) system. To test whether the desiccation resistant, highly melanised cell walls would hinder protoplast formation, we treated a melanin-minus mutant of A95 as well as the type-strain with a variety of cell-degrading enzymes. Of the different enzymes tested, lysing enzymes from Trichoderma harzianum were most effective in producing protoplasts. This mixture was equally effective on the melanin-minus mutant and the type-strain. Protoplasts produced using lysing enzymes were mixed with polyethyleneglycol (PEG) and plasmid pCB1004 which contains the hygromycin B (HmB) phosphotransferase (hph) gene under the control of the Aspergillus nidulans trpC. Integration and expression of hph into the A95 genome conferred hygromycin resistance upon the transformants. Two weeks after plating out on selective agar containing HmB, the protoplasts developed cell-walls and formed colonies. Transformation frequencies were in the range 36 to 87 transformants per 10 µg of vector DNA and 106 protoplasts. Stability of transformation was confirmed by sub-culturing the putative transformants on selective agar containing HmB as well as by PCR-detection of the hph gene in the colonies. The hph gene was stably integrated as shown by five subsequent passages with and without selection pressure.
KW - DNA transfer
KW - Fungal cell-walls
KW - Protoplasts
KW - Hygromycin resistance
KW - Black yeast
KW - Sub-aerial biofilms
KW - Stress-protective morphology
KW - Ancestor of opportunistic pathogens & lichens
PY - 2014
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-320840
UR - http://www.amb-express.com/content/4/1/80
DO - https://doi.org/10.1186/s13568-014-0080-5
SN - 2191-0855
VL - 4
SP - 80, 1
EP - 6
PB - Springer
CY - Heidelberg
AN - OPUS4-32084
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Erdmann, Eileen A.
A1 - Brandhorst, Antonia K. M.
A1 - Gorbushina, Anna
A1 - Schumacher, Julia
T1 - The Tet‑on system for controllable gene expression in the rock‑inhabiting black fungus Knufia petricola
N2 - Knufia petricola is a black fungus that colonizes sun-exposed surfaces as extreme and oligotrophic environments. As ecologically important heterotrophs and biofilm-formers on human-made surfaces, black fungi form one of the most resistant groups of biodeteriorating organisms. Due to its moderate growth rate in axenic culture and available protocols for its transformation and CRISPR/Cas9-mediated genome editing, K. petricola is used for studying the morpho-physiological adaptations shared by extremophilic and extremotolerant black fungi. In this study, the bacteria-derived tetracycline (TET)-dependent promoter (Tet-on) system was implemented to enable controllable gene expression in K. petricola. The functionality i.e., the dose-dependent inducibility of TET-regulated constructs was investigated by using GFP fluorescence, pigment synthesis(melanin and carotenoids) and restored uracil prototrophy as reporters. The newly generated cloning vectors containing the Tet-on construct, and the validated sites in the K. petricola genome for color-selectable or neutral insertion of expression constructs complete the reverse genetics toolbox. One or multiple genes can be expressed on demand from different genomic loci or from a single construct by using 2A self-cleaving peptides, e.g., for localizing proteins and protein complexes in the K. petricola cell or for using K. petricola as host for the expression of heterologous genes.
KW - Microcolonial fungi
KW - Inducible promoter
KW - Bimolecular fluorescence complementation
KW - 2A peptide
KW - CRISPR/ Cas9-mediated genome editing
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-607672
DO - https://doi.org/10.1007/s00792-024-01354-2
VL - 28
IS - 38
SP - 1
EP - 13
PB - Springer Nature
AN - OPUS4-60767
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Wetzel, Annica
A1 - Morell, Daniel
A1 - von der Au, Marcus
A1 - Witt, Julia
A1 - Özcan Sandikcioglu, Özlem
T1 - Transpassive Behavior of Equimolar CrMnFeCoNi and CrCoNi Multi‐Principal Element Alloys in an Alkaline NaCl Electrolyte
N2 - AbstractWe investigated the corrosion properties and transpassive behavior of CrMnFeCoNi and CrCoNi multi‐principal element alloys (MPEAs) in a 0.1 M NaCl electrolyte at pH 12. By using SECM‐based tip substrate voltammetry (TSV) in combination with the chemical analysis of the electrolyte, we were able to differentiate between anodic metal dissolution and oxygen evolution in the transpassive range. Our investigations have shown that CrCoNi has a significantly higher corrosion resistance compared to CrMnFeCoNi. In the studied alkaline environment, a transpassive oxide film is formed on the surface of CrCoNi during secondary passivation. This transpassive oxide film appears to play a significant role in oxygen evolution, as the increase in TSV currents at the microelectrode coincides with the corresponding current density plateau of the voltametric current trace. The formation of the transpassive oxide film was not observed in previous studies conducted in acidic environments. Moreover, the alkaline electrolyte induced a positive hysteresis and mild pitting corrosion, in addition to intergranular corrosion, which was the sole corrosion process observed at acidic pH levels. These findings enhance the understanding of the processes governing the transpassivity of CrMnFeCoNi and CrCoNi MPEAs in alkaline environments and have potential implications for the development of application‐tailored corrosion‐resistant MPEAs.
KW - Multi-principal element alloys
KW - MPEA
KW - Corrosion
KW - Oxygen evolution reaction
KW - Transpassive region
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-611594
DO - https://doi.org/10.1002/celc.202400346
SN - 2196-0216
SP - 1
EP - 9
PB - Wiley
AN - OPUS4-61159
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Ginés-Palomares, J.-C.
A1 - Fateri, M.
A1 - Schubert, T.
A1 - de Peindray d’Ambelle, L.
A1 - Simon, Sebastian
A1 - Gluth, Gregor
A1 - Günster, Jens
A1 - Zocca, Andrea
T1 - Material aspects of sintering of EAC-1A lunar regolith simulant
N2 - Future lunar exploration will be based on in-situ resource utilization (ISRU) techniques. The most abundant raw material on the Moon is lunar regolith, which, however, is very scarce on Earth, making the study of simulants a necessity. The objective of this study is to characterize and investigate the sintering behavior of EAC-1A lunar regolith simulant. The characterization of the simulant included the determination of the phase assemblage, characteristic temperatures determination and water content analysis. The results are discussed in the context of sintering experiments of EAC-1A simulant, which showed that the material can be sintered to a relative density close to 90%, but only within a very narrow range of temperatures (20–30 °C). Sintering experiments were performed for sieved and unsieved, as well as for dried and non-dried specimens of EAC-1A. In addition, an analysis of the densification and mechanical properties of the sintered specimens was done. The sintering experiments at different temperatures showed that the finest fraction of sieved simulant can reach a higher maximum sintering temperature, and consequently a higher densification and biaxial strength. The non-dried powder exhibited higher densification and biaxial strength after sintering compared to the dried specimen. This difference was explained with a higher green density of the non-dried powder during pressing, rather than due to an actual influence on the sintering mechanism. Nevertheless, drying the powder prior to sintering is important to avoid the overestimation of the strength of specimens to be fabricated on the Moon.
KW - Lunar regolith
KW - Ceramics
KW - Microstructure
KW - Sintering
KW - Softening temperature
PY - 2023
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-592668
DO - https://doi.org/10.1038/s41598-023-50391-y
SN - 2045-2322
VL - 13
SP - 1
EP - 14
PB - Springer Nature
AN - OPUS4-59266
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Günster, Jens
A1 - Wang, Gong
A1 - Tian, Xiaoyong
T1 - 3D Printing Technologies for Extreme Environment in Space
N2 - 3D printing technology can realize the rapid fabrication of complicated structures with short production chain, which just meet the requirements for space manufacturing in the future. However, 3D printing technologies in space are still challenging due to the harsh conditions, such as microgravity, high vacuum, and large temperature difference. Meanwhile, in-situ resource utilization and recycling must be considered as a cost effective and resilient resource for 3D printing in space. On the contrary, extreme environmental conditions such as high vacuum and microgravity can also offer significant advantages for advanced materials with high purity and performance. In-situ fabrication of ultra-large components would overcome the weight and structural limitations imposed by rocket launch and change the future strategy for space exploration. The aim of this specially issue is therefore to provide a platform for discussing the potential technologies for 3D printing in space.
KW - Additive Manufacturing
KW - space
PY - 2025
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-652654
DO - https://doi.org/10.1016/j.amf.2025.200248
SN - 2950-4317
VL - 4
IS - 3
SP - 1
EP - 2
PB - Elsevier
AN - OPUS4-65265
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Recknagel, Sebastian
A1 - Richter, Silke
A1 - Hoppe, Marion
A1 - Meckelburg, Angela
A1 - Prinz, Carsten
A1 - Roik, Janina
A1 - Abad Andrade, Carlos Enrique
T1 - Powering precision: development of a certified reference material for elemental composition analysis of lithium nickel manganese cobalt oxide (Li-NMC) cathode material for lithium-ion batteries
N2 - This work presents the development and certification of the world’s first certified reference material (CRM), BAM-S014, for a lithium nickel manganese cobalt oxide (LiNi0.33Mn0.33Co0.33O2 or Li-NMC 111) cathode material—an integral component in high-energy-density lithium-ion batteries that power electric vehicles (EVs), portable electronics, and stationary energy storage systems. By providing certified mass fractions for 11 elements, this CRM addresses a critical need for accurate and traceable elemental analysis, supporting quality control and regulatory compliance in the global battery industry. Ensuring reliable and harmonized measurements supports the efficient use of resources, including the reuse of recycled materials, and ultimately helps maintain product performance and safety. The values were assigned through an interlaboratory comparison involving 16 participating laboratories and various analytical techniques such as inductively coupled plasma optical emission spectrometry (ICP-OES), inductively coupled plasma mass spectrometry (ICP-MS), X-ray fluorescence (XRF) spectrometry, and combustion analysis. In addition to chemical characterization, the certification process includes homogeneity and stability testing of the candidate material. Details are provided on the analytical methods used for chemical characterization and the calculation of the uncertainties of the certified mass fractions. In addition to detailing the development of the CRMs, this work provides an overview of ongoing standardization activities in Li-component analysis, thereby guiding the calibration of analytical methods and contributing to the establishment of globally accepted standards for evaluating energy storage materials and advancing sustainable mobility and clean energy solutions.
KW - Certified reference material
KW - Lithium nickel manganese cobalt oxide
KW - LNMC
KW - Lithium-ion battery
KW - Cathode material
PY - 2025
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-643763
DO - https://doi.org/10.1007/s00216-025-05766-7
SN - 1618-2642
VL - 417
IS - 12
SP - 2643
EP - 2653
PB - Springer Nature
AN - OPUS4-64376
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Chakraborty, Gouri
A1 - Das, Prasenjit
A1 - Bhattacharya, Biswajit
A1 - Prinz, Carsten
A1 - Emmerling, Franziska
A1 - Thomas, Arne
T1 - Room-temperature superprotonic conductivity in COOH-functionalized multicomponent covalent organic frameworks
N2 - In solid materials, the development of hydrogen bonding (H-bonding) networks within pores is crucial for efficient proton conductance. In this study, a chemically stable carboxylic acid-functionalized, quinoline-linked 2D microporous covalent organic framework (COF) (Qy-COOH) was synthesized using the Doebner multicomponent reaction (MCR) and compared to a similar framework lacking the –COOH functionality (Qy-H), prepared via an MC Domino reaction. The proton conductivity of the –COOH-functionalized MCR-COF was significantly enhanced, reaching 10−2 S cm−1, attributed to strong H-bonding interactions between water molecules and the dangling –COOH groups within the COF pores. In contrast, the analogous Qy-H framework exhibited a much lower proton conductivity of 10−5 S cm−1, while an imine-based COF showed only 10−6 S cm−1. This work represents the first demonstration of a general strategy to achieve efficient proton conduction in a class of layered 2D –COOH-functionalized COFs, offering superprotonic conductivity without requiring additives at room temperature. The MCR-COF design approach provides a promising pathway for developing highly stable and high-performance proton-conducting materials.
KW - Multicomponebt
KW - COF
KW - Proton Conductivity
KW - Superprotonic
PY - 2026
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-653526
DO - https://doi.org/10.1039/D5SC06953J
SN - 2041-6520
SP - 1
EP - 9
PB - Royal Society of Chemistry (RSC)
AN - OPUS4-65352
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Mohabbat, Abdulrahman
A1 - Boldog, István
A1 - Reistel, Nils
A1 - de Sousa Amadeu, Nader
A1 - Möllmer, Jens
A1 - Lange, Marcus
A1 - Limon, Aysenur
A1 - Seiffert, Philipp
A1 - Michalski, Julia
A1 - Janiak, Christoph
T1 - P4O10-mediated synthesis of polar polyphosphoric acid-covalent triazine framework composites from aromatic amides for improved water and SO2 sorption
N2 - Polycondensation of various aromatic amides in P4O10 at 400 8C yields covalent triazine frameworks intergrown with a polyphosphoric acid framework (POF-CTFs). Compared to ionothermal analogs, they feature a shorter reaction time and strongly increased framework polarity for water and SO2 uptake, and SO2/CO2
selectivity
KW - COF
PY - 2025
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-644208
DO - https://doi.org/10.1039/d5cc03419a
SN - 1359-7345
SP - 1
EP - 4
PB - Royal Society of Chemistry (RSC)
AN - OPUS4-64420
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Leonhardt, Robert
A1 - Krug von Nidda, Jonas
A1 - Andrae, Dirk
A1 - Schmidt, Anita
A1 - Kowal, Julia
A1 - Tichter, Tim
T1 - Reconstructing the distribution of relaxation times with analytical basis functions
N2 - The present work proposes the implementation of non-singular basis functions into the algorithm for reconstructing the distribution of relaxation times (DRT) function of impedance data. These functions reflect the dispersed and asymmetrical nature of non-ideal capacitive–resistive processes. Inclusion is achieved by combining the singular Debye distribution basis with distributed relaxation functions, such as those derived from the analytical models of Cole–Cole and Havriliak–Negami. The shapes of the introduced basis functions are described by constant parameters, for which an empirical optimization approach is provided alongside. Using synthetic impedance data of non-ideal capacitive–resistive processes subjected to white noise, it is shown that the demand for regularization can be reduced significantly by using distributed bases. To underline the practical relevance of non-singular basis functions in DRT reconstruction, an experimental study comprising 100 sodium-ion and 80 lithium-ion ommercial cells is presented. In this context, it is shown that auxiliary information from the non-ideal nature of real-world electrochemical processes is outsourced into the basis and, hence, easily filtered out of the resulting DRT. This facilitates the separation of single processes without post-DRT curve fitting and thus improves the interpretation
and classification of impedance data significantly.
KW - Electrochemical Impedance Spectroscopy;
KW - Distribution of relaxation times
KW - Basis function
KW - Cole-Cole
KW - Cole-Davidson
KW - Havriliak-Negami
PY - 2025
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-635486
DO - https://doi.org/10.1016/j.jpowsour.2025.237403
SN - 0378-7753
VL - 652
SP - 1
EP - 11
PB - Elsevier B.V.
AN - OPUS4-63548
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Rodríguez-Sánchez, Noelia
A1 - Domínguez-Santos, J. Enrique
A1 - Bhattacharya, Biswajit
A1 - Prinz, Carsten
A1 - Canosa, Inés
A1 - Flores, Amando
A1 - Jiménez-Rodríguez, Antonia
A1 - Ruiz-Salvador, A. Rabdel
A1 - Emmerling, Franziska
A1 - Ballesteros, Menta
T1 - Mechanochemical synthesis of multivariate UPO-3 (Cu-ZIF-9-ica) MOF for inactivation of antibiotic-resistant bacteria and irrigation-quality water production via heterogeneous photo-Fenton catalysis
N2 - Water scarcity and pollution are critical global challenges, particularly in agriculture, the largest consumer of water. The development of sustainable, effective, and environmentally friendly disinfection methods is essential to address the risks posed by antibiotic-resistant bacteria and to ensure safe reuse of water for irrigation. In this study, we report the synthesis of the metal-organic framework (MOF) Universidad Pablo de Olavide-3 (UPO-3) via a mechanochemical approach, a scalable and sustainable method compared to traditional solvothermal synthesis. The resulting UPO-3/H2O2 system exhibits robust photocatalytic properties under visible light, achieving effective and broad-spectrum antibacterial activity. The disinfection efficiency of the catalyst was evaluated against Escherichia coli as a model of microbial pathogen in two saline matrices, considering the key parameters of the heterogeneous photo-Fenton process, including catalyst dosage, initial H2O2 concentration, and light irradiation. Notably, it inactivated two important virulent and antibiotic-resistant bacterial pathogens (Staphylococcus aureus and Pseudomonas aeruginosa). Furthermore, UPO-3 shows exceptional performance under real-world conditions, such as river water disinfection, achieving >5-log reduction of E. coli, fulfilling a critical criterion for Class A water reuse under Regulation (EU) 2020/741. These results highlight UPO-3 as a versatile and sustainable solution for water reuse, addressing water scarcity and advancing efforts to achieve United Nations Sustainable Development Goal 6.
KW - Water reuse
KW - Antibiotic-resistant bacteria
KW - Water disinfection
KW - Mechanochemical synthesis
KW - Metal organic framework
PY - 2025
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-639766
DO - https://doi.org/10.1016/j.chemosphere.2025.144610
SN - 0045-6535
VL - 386
SP - 1
EP - 11
PB - Elsevier Ltd.
AN - OPUS4-63976
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Bügel, Stefanie
A1 - Hähnel, Malte
A1 - Kunde, Tom
A1 - de Sousa Amadeu, Nader
A1 - Sun, Yangyang
A1 - Spieß, Alex
A1 - Beglau, Thi Hai Yen
A1 - Schmidt, Bernd M.
A1 - Janiak, Christoph
T1 - Synthesis and Characterization of a Crystalline Imine-Based Covalent Organic Framework with Triazine Node and Biphenyl Linker and Its Fluorinated Derivate for CO2/CH4 Separation
N2 - : A catalyst-free Schiff base reaction was applied to synthesize two imine-linked covalent organic frameworks (COFs). The condensation reaction of 1,3,5-tris-(4-aminophenyl)triazine (TAPT) with 4,40-biphenyldicarboxaldehyde led to the structure of HHU-COF-1 (HHU = Heinrich-Heine University). The fluorinated analog HHU-COF-2 was obtained with 2,20,3,30,5,50,6,60-octafluoro 4,40
-biphenyldicarboxaldehyde. Solid-state NMR, infrared spectroscopy, X-ray photoelectron spectroscopy, and elemental analysis confirmed the successful formation of the two network structures. The crystalline materials are characterized by high Brunauer–Emmett–Teller surface areas of 2352 m2/g for HHU-COF-1 and 1356 m2/g for HHU-COF-2. The products of a larger-scale synthesis were applied to prepare mixed-matrix membranes (MMMs) with the polymer Matrimid. CO2/CH4 permeation tests revealed a moderate increase in CO2 permeability at constant selectivity for HHU-COF-1 as a dispersed phase, whereas application of the fluorinated COF led to a CO2/CH4 selectivity increase from 42 for the pure Matrimid membrane to 51 for 8 wt% of HHU-COF-2 and a permeability increase from 6.8 to 13.0 Barrer for the 24 wt% MMM
KW - Separation
KW - COF
KW - MMM
KW - CO2
PY - 2022
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-618625
DO - https://doi.org/10.3390/ma15082807
VL - 15
IS - 8
SP - 2807
PB - MDPI
AN - OPUS4-61862
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Zaki, Mohammad
A1 - Prinz, Carsten
A1 - Ruehle, Bastian
T1 - A Self-Driving Lab for Nano- and Advanced Materials Synthesis
N2 - The recent emergence of self-driving laboratories (SDL) and material acceleration platforms (MAPs) demonstrates the ability of these systems to change the way chemistry and material syntheses will be performed in the future. Especially in conjunction with nano- and advanced materials which are generally recognized for their great potential in solving current material science challenges, such systems can make disrupting contributions. Here, we describe in detail MINERVA, an SDL specifically built and designed for the synthesis, purification, and in line characterization of nano- and advanced materials. By fully automating these three process steps for seven different materials from five representative, completely different classes of nano- and advanced materials (metal, metal oxide, silica, metal organic framework, and core–shell particles) that follow different reaction mechanisms, we demonstrate the great versatility and flexibility of the platform. We further study the reproducibility and particle size distributions of these seven representative materials in depth and show the excellent performance of the platform when synthesizing these material classes. Lastly, we discuss the design considerations as well as the hardware and software components that went into building the platform and make all of the components publicly available.
KW - Self-driving laboratories
KW - Materials acceleration platforms
KW - Nanomaterials
KW - Advanced materials
KW - Automation
KW - Robotics
KW - In-line characterization
PY - 2025
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-627361
DO - https://doi.org/10.1021/acsnano.4c17504
SN - 1936-086X
VL - 19
IS - 9
SP - 9029
EP - 9041
PB - ACS Publications
CY - Washington, DC
AN - OPUS4-62736
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Kossatz, Philipp
A1 - Mezhov, Alexander
A1 - Andresen, Elina
A1 - Prinz, Carsten
A1 - Schmidt, Wolfram
A1 - Resch-Genger, Ute
T1 - Assessing the Applicability of Lanthanide-Based Upconverting Nanoparticles for Optically Monitoring Cement Hydration and Tagging Building Materials
N2 - Chemically stable, lanthanide-based photon upconversion micro- and nanoparticles (UCNPs) with their characteristic multicolor emission bands in the ultraviolet (UV), visible (vis), near-infrared (NIR), and short-wave infrared (SWIR) arepromising optical reporters and barcoding tags. To assess the applicability of UCNPs for the monitoring of early stage cement hydration processes and as authentication tags for cementitious materials, we screened the evolution of the luminescence of Selfmade core-only NaYF4:Yb,Er UCNPs and commercial μm-sized Y2O2S:Yb,Er particles during the first stages of cement hydration, which largely determines the future properties of the hardened material. Parameters explored from the UCNP side included particle size, morphology, surface chemistry or coating, luminescence properties, and concentration in different cement mixtures. From the cement side, the influence of the mineral composition of the cement matrix was representatively examined for ordinary Portland cement (OPC) and its constituents tricalcium aluminate (C3A), tricalcium silicate (C3S), and gypsum at different water to cement ratios. Based on reflection and luminescence measurements, enabling online monitoring, which were complemented by XRD and isothermal heat-flow calorimetric measurements to determine whether the incorporation of these particles could impair cement hydration processes, well suited lanthanide particle reporters could be identified as well as application conditions. In addition, thereby the reporter influence on cement hydration kinetics could be minimized while still preserving a high level of information content. The best performance for the luminescence probing of changes during early stage cement hydration processes was observed for 25 nm-sized oleate (OA)-coated UCNPs added in a concentration of 0.1 wt %. Higher UCNP amounts of 1.0 wt % delayed cement hydration processes size- and surface coatingspecifically in the first 24 h. Subsequent luminescence stability screening studies performed over a period of about one year support the applicability of UCNPs as optical authentication tags for construction materials.
KW - Quality assurance
KW - Fluorescence
KW - Nano
KW - Particle
KW - Synthesis
KW - Quantum yield
KW - NIR
KW - Mechanism
KW - Characterization
KW - XRD
KW - Calorimetry
KW - Advanced material
KW - Cement
KW - Monitoring
KW - Surface
KW - Size
KW - Lifetime
KW - Barcode
KW - Lanthanide
KW - Upconversion
KW - Encoding
KW - Method
PY - 2025
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-638318
DO - https://doi.org/10.1021/acsomega.5c02236
SN - 2470-1343
VL - 10
IS - 29
SP - 31587
EP - 31599
PB - ACS Publications
CY - Washington, DC
AN - OPUS4-63831
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Rodríguez-Sánchez, Noelia
A1 - Prinz, Carsten
A1 - Bienert, Ralf
A1 - Ballesteros, Menta
A1 - Ruiz Salvador, A. Rabdel
A1 - Bhattacharya, Biswajit
A1 - Emmerling, Franziska
T1 - Mechanochemical ZIF-9 formation: in situ analysis and photocatalytic enhancement evaluation
N2 - Efficient treatment of persistent pollutants in wastewater is crucial for sustainable water management and environmental protection. This study addresses this challenge by investigating the mechanochemical synthesis and photocatalytic performance of ZIF-9, a cobalt-based zeolitic imidazolate framework. Using synchrotron-based powder X-ray diffraction, we provide real-time insights into the formation dynamics of ZIF-9 during mechanosynthesis. Our results show that mechanochemically synthesised ZIF-9 exhibits superior photocatalytic activity compared to its solvothermally prepared counterpart, achieving a 2-fold increase in methylene blue degradation rate. This research not only advances our understanding of the synthesis and properties of ZIF-9, but also demonstrates the potential of mechanochemical approaches in the development of high-performance, sustainably produced materials for water treatment and other environmental applications.
KW - MOFs
KW - ZIF
KW - Time-resolved in situ investigation
KW - Photocatalysis synchrotron X-ray powder diffraction
PY - 2025
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-641416
DO - https://doi.org/10.1039/D4MR00114A
SN - 2976-8683
VL - 2
IS - 1
SP - 116
EP - 126
PB - Royal Society of Chemistry (RSC)
CY - Cambridge
AN - OPUS4-64141
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Rodríguez-Sánchez, Noelia
A1 - Bhattacharya, Biswajit
A1 - Emmerling, Franziska
A1 - Prinz, Carsten
A1 - Prieto-Laria, P.
A1 - Ruiz-Salvador, A.R.
A1 - Ballesteros, M.
T1 - Engineering a multivariate cobalt metal–organic framework for high photocatalytic activity: the impact of mixed ligands and metal incorporation in a visible light-driven heterogeneous photo-Fenton reaction for water treatment
N2 - Metal–organic frameworks (MOFs) have attracted increasing attention for the removal of organic pollutants in wastewater via photocatalysis. Here, we design a multivariate modification of ZIF-9 to tune its electronic properties for use in visible light photocatalysis. A controllable synthesis of ZIF-9 and its multivariate forms with the incorporation of copper and the 2-imidazolecarboxaldehyde (ica) ligand was carried out. The materials are tested for the removal of the model dye methylene blue (MB) by a heterogeneous photo-Fenton-like reaction at neutral pH and room temperature. Cu-ZIF-9-ica (UPO-3) shows high photocatalytic activity under both visible and ultraviolet A (UVA) light, achieving 94% MB degradation in 45 min, compared to 65% MB degradation in 120 min using bare ZIF-9. The study revealed a first-order rate constant of 0.0475 min−1 for Cu-ZIF-9-ica compared to 0.0088 min−1 for ZIF-9 under visible light. The improvement of the catalyst was clearly attributed to the co-incorporation of Cu and the ica ligand in the MOF, which reduces the band gap, in agreement with DFT calculations. Reproducibility and recyclability tests proved that Cu-ZIF-9-ica can be used for at least 3 cycles without a significant loss of efficiency, making it a promising material for the study and application of wastewater treatment.
KW - Metal-Organic Framework (MOF)
KW - Heterogeneous photo-Fenton
KW - ZIF-9
KW - Methylene Blue
PY - 2025
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-630797
DO - https://doi.org/10.1039/d4na00954a
SN - 2516-0230
VL - 7
IS - 8
SP - 2255
EP - 2265
PB - Royal Society of Chemistry
AN - OPUS4-63079
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Chouquet, Xavier
A1 - Bolten, Julia
A1 - Prinz, Carsten
A1 - Günster, Jens
A1 - Zocca, Andrea
ED - Vincenzini, P.
T1 - Direct ink writing of zeolite-like AQSOA Z02 for envisioned applications in solar-driven atmospheric water harvesting: Paste formulation and effect of thermal treatments on the water sorption propertie
N2 - This work presents the development of porous water adsorbent bodies with complex geometries shaped by direct ink writing additive manufacturing. AQSOA FAM Z02 (Z02), a commercial material similar to SAPO-34 with chabazite structure, was selected as sorbent material. Dynamic vapor sorption analysis demonstrated that Z02 adsorbs and desorbs up to 30 % of its own mass in each cycle, highlighting its potential for this application. To optimize its printability for direct ink writing, aqueous pastes composed of Z02 and bentonite were formulated. Bentonite served as the inorganic binder and was responsible for the mechanical stability of the printed porous bodies after heat treatment. The most suitable paste composition was identified and used to fabricate scaffold structures. These structures were then subjected to different heat treatments at 650 °C, 750 °C and 850 °C to find a suitable compromise between mechanical stability and retention of the sorption properties. Scaffold structures printed with a 20 wt% of bentonite binder were mechanically stable (1.9 ± 1.1 MPa compressive strength) and retained a maximum water uptake of ca. 25 wt% after heat treatment at 750 °C for 1 h.
KW - Direct ink writing
KW - Zeolite
KW - Direct ink wriDynamic vapor sorption
KW - Bentonite Water harvesting
PY - 2025
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-643150
DO - https://doi.org/10.1016/j.ceramint.2025.09.314
SN - 0272-8842
SP - 1
EP - 12
PB - Elsevier Ltd.
AN - OPUS4-64315
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Appel, Paul Alexander
A1 - Prinz, Carsten
A1 - Low, Jian Liang
A1 - Asres, Nahom Enkubahri
A1 - Wu, Shu-Han
A1 - Freytag, Annica
A1 - Krug von Nidda, Jonas
A1 - de Sousa Amadeu, Nader
A1 - Fellinger, Tim-Patrick
T1 - Core‐Shell: Resolving the Dilemma of Hard Carbon Anodes by Sealing Nanoporous Particles With Semi‐Permeable Coatings
N2 - A core-shell strategy is introduced to overcome the dilemma of common non-graphitic hard carbon anodes, linking high reversible storage capacity to practically unacceptable irreversible losses in the first cycle(s). Just as Graphite homogeneously combines effective lithium storage with an electrolyte solvent-sieving function, we show that both of these functions could be strategically integrated into non-graphitic carbons in a heterogeneous structure. Highly porous activated carbons are sealed by kinetically tuned gas-phase deposition of non-graphitic carbon to form a functional core-shell structure. Gas sorption porosimetry on core, shell, core–shell, and cracked core-shell particles confirms preserved core porosity and a semi-permeable shell. Diethyl carbonate sorption analysis is introduced as a more suitable probe than N2 or CO2 sorption, linking first-cycle losses to the liquid–solid interface of carbon anodes. The functional core-shell particles with much reduced diethyl carbonate uptake allow for high storage capacity and reduced first cycle losses. Delivering 400 ± 24 mAh g−1 with 82 ± 2% first-cycle reversibility, it is shown that three-stage Na storage in designed core-shell anodes can compensate for the larger size of sodium compared to lithium stored in graphite anodes (372 mAh g−1). The designed core-shell anodes show state-of-the-art performance with commercial promise.
KW - Sodium-ion battery
KW - Activated carbon
KW - Core-shell
KW - Hard carbon anode
KW - Diethyl carbonate vapor sorption
PY - 2026
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-655346
DO - https://doi.org/10.1002/anie.202519457
SN - 1433-7851
N1 - Es gibt eine parallele Sprachausgabe (deutsch), ein Link befindet sich im Feld zugehöriger Identifikator - There is a parallel language edition (German), a link is in the field related identifier
SP - 1
EP - 9
PB - Wiley-VCH
CY - Weinheim
AN - OPUS4-65534
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Dittrich, Bettina
A1 - Wartig, K.-A.
A1 - Mülhaupt, R.
A1 - Schartel, Bernhard
T1 - Flame-retardancy properties of intumescent ammonium poly(phosphate) and mineral filler magnesium hydroxide in combination with graphene
N2 - Thermally reduced graphite oxide (TRGO), containing only four single carbon layers on average, was combined with ammonium polyphosphate (APP) and magnesium hydroxide (MH), respectively, in polypropylene (PP). The nanoparticle's influence on different flame-retarding systems and possible synergisms in pyrolysis, reaction to small flame, fire behavior and mechanical properties were determined. TRGO has a positive effect on the yield stress, which is decreased by both flame-retardants and acts as a synergist with regard to Young's modulus. The applicability and effects of TRGO as an adjuvant in combination with conventional flame-retardants depends strongly on the particular flame-retardancy mechanism. In the intumescent system, even small concentrations of TRGO change the viscosity of the pyrolysing melt crucially. In case of oxygen index (OI) and UL 94 test, the addition of increasing amounts of TRGO to PP/APP had a negative impact on the oxygen index and the UL 94 classification. Nevertheless, systems with only low amounts (≤1 wt%) of TRGO achieved V-0 classification in the UL 94 test and high oxygen indices (>31 vol%). TRGO strengthens the residue structure of MH and therefore functions as a strong synergist in terms of OI and UL 94 classification (from HB to V-0).
KW - Graphene
KW - Intumescence
KW - Ammonium polyphosphate
KW - Magnesium hydroxide
KW - Synergy
KW - Polypropylene
PY - 2014
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-320685
DO - https://doi.org/10.3390/polym6112875
SN - 2073-4360
VL - 6
IS - 11
SP - 2875
EP - 2895
PB - MDPI
CY - Basel
AN - OPUS4-32068
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Dackermann, U.
A1 - Yu, Y.
A1 - Niederleithinger, Ernst
A1 - Li, J.
A1 - Wiggenhauser, Herbert
T1 - Condition Assessment of Foundation Piles and Utility Poles Based on Guided Wave Propagation Using a Network of Tactile Transducers and Support Vector Machines
N2 - This paper presents a novel non-destructive testing and health monitoring system using a network of tactile transducers and accelerometers for the condition assessment and damage classification of foundation piles and utility poles. While in traditional pile integrity testing an impact hammer with broadband frequency excitation is typically used, the proposed testing system utilizes an innovative excitation system based on a network of tactile transducers to induce controlled narrow-band frequency stress waves. Thereby, the simultaneous excitation of multiple stress wave types and modes is avoided (or at least reduced), and targeted wave forms can be generated. The new testing system enables the testing and monitoring of foundation piles and utility poles where the top is inaccessible, making the new testing system suitable, for example, for the condition assessment of pile structures with obstructed heads and of poles with live wires. For system validation, the new system was experimentally tested on nine timber and concrete poles that were inflicted with several types of damage. The tactile transducers were excited with continuous sine wave signals of 1 kHz frequency. Support vector machines were employed together with advanced signal processing algorithms to distinguish recorded stress wave signals from pole structures with different types of damage. The results show that using fast Fourier transform signals, combined with principal component analysis as the input feature vector for support vector machine (SVM) classifiers with different kernel functions, can achieve damage classification with accuracies of 92.5% ± 7.5%.
KW - Structural Health Monitoring
KW - Non-Destructive Testing
KW - Sensor network
KW - Support vector machine
KW - Utility poles
PY - 2017
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-434868
UR - http://www.mdpi.com/1424-8220/17/12/2938
DO - https://doi.org/10.3390/s17122938
SN - 1424-8220
VL - 17
IS - 12
SP - Article 2938, 1
EP - 16
PB - MDPI
CY - Basel, Schweiz
AN - OPUS4-43486
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Stengel, Dominik
A1 - Thiele, K.
T1 - Measurements of downburst wind loading acting on an overhead transmission line in Northern Germany
N2 - Along an overhead transmission line in Northern Germany, a unique instrumentation of anemometers and force measurements is installed. Details of this test line with wind measurements along a horizontal axis are given. A recent event of a presumable downburst wind event is analyzed by means of available data and precedent works on thunderstorm analysis. The measured response of the conductors at the suspension tower is investigated and compared with time domain simulation of a finite element model.
T2 - X International Conference on Structural Dynamics, EURODYN 2017
CY - Rome, Italy
DA - 10.09.2017
KW - Non-synoptic wind event
KW - Downburst
KW - Overhead transmission line
KW - Finite element method
PY - 2017
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-421239
DO - https://doi.org/10.1016/j.proeng.2017.09.578
SN - 1877-7058
VL - 199
IS - Supplement C
SP - 3152
EP - 3157
PB - Elsevier
AN - OPUS4-42123
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Auersch, Lutz
T1 - Mitigation of railway induced vibration at the track, in the transmission path through the soil and at the building
N2 - This contribution presents some principles and some examples of the mitigation of railway-induced ground vibrations. The principles are different for the mitigation measures at the track, in the soil or at the building. Force transfer functions of isolated and un-isolated track-soil systems, reflected and transmitted wave amplitudes at walls and trenches in the soil, and the transfer of the (free-field) vibration amplitudes to the foundation amplitudes of the building are analysed. The mitigation effect can be calculated by exact or simplified formulas. Some examples with 3D (finite-element boundary-element), 2D (beam-on-support), and 1D track models, 2D and 1D soil models, detailed 3D building models and finite or infinite 1D wall-floor models are investigated to find out if simple models can be used for a satisfactory prediction of the mitigation effect. The 1D track examples show that the force transfer of the track without vehicle can be exactly calculated, whereas the total force transfer can be calculated approximately if appropriate wheelset masses per track length are used for the isolated and the un-isolated track. The mitigation effect of a filled trench is calculated by a 2D finite element model and the results compare with simple transmission formula if the stiffness per area rather than the wave impedances are used for the infill material. The base isolation of a building is analysed by a detailed 3D model and the results are similar to the analytic results of a single wall with floors on the soil. Other reduction measures as different floor and column dimensions are usually less effective so that the clearly best mitigation solution at a building is a partly or a complete base isolation.
T2 - X INTERNATIONAL CONFERENCE ON STRUCTURAL DYNAMICS (EURODYN 2017)
KW - Mitigation
KW - Soil-building interaction
KW - Base isolation
KW - Ground vibration
PY - 2017
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-420869
DO - https://doi.org/10.1016/j.proeng.2017.09.192
SN - 1877-7058
VL - 199
SP - 2312
EP - 2317
PB - Elsevier
CY - London
AN - OPUS4-42086
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Schäfer, N.
A1 - Chahine, G. A.
A1 - Wilkinson, A. J.
A1 - Schmid, Thomas
A1 - Rissom, T.
A1 - Schülli, T. U.
A1 - Abou-Ras, D.
T1 - Microstrain distributions in polycrystalline thin films measured by X-ray microdiffraction
N2 - Microstrain distributions were acquired in functional thin films by high-resolution X-ray microdiffraction measurements, using polycrystalline CuInSe2 thin films as a model system. This technique not only provides spatial resolutions at the submicrometre scale but also allows for analysis of thin films buried within a complete solar-cell stack. The microstrain values within individual CuInSe2 grains were determined to be of the order of 10^-4. These values confirmed corresponding microstrain distribution maps obtained on the same CuInSe2 layer by electron backscatter diffraction and Raman microspectroscopy.
KW - Microstrain distribution
KW - X-ray microdiffraction
KW - Polycrystalline thin films
KW - Raman microscopy
PY - 2016
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-366592
DO - https://doi.org/10.1107/S1600576716003204
SN - 1600-5767
VL - 49
SP - 632
EP - 635
AN - OPUS4-36659
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Auersch, Lutz
A1 - Said, Samir
A1 - Müller, Roger
T1 - Measurements on the vehicle-track interaction and the excitation of railway-induced ground vibration
N2 - Two railway measurement campaigns have been performed in Germany and Switzerland which yield insight in the vehicle-track-soil interaction. The campaign in Germany has included simultaneous measurement of vehicle, track, and soil vibrations during train runs with 16, 25, 40, 63, 80, 100, 125, 140, 160 km/h, and impulse measurements of the passenger car, three track sections and the soil. Two ballast tracks, one on the soil surface and one on a concrete bridge, have been investigated as well as a slab track in a tunnel. Ten different sites in Switzerland have been measured for soil properties and train-induced ground vibrations, which allow to determine the excitation forces of the railway traffic. New axle-box measurements at some of the Swiss sites have been analysed to get further experimental evidence. All these measurements have been evaluated to characterize the excitation processes. Relations between vehicle vibration and ground vibration can be observed. The vehicle vibrations, namely the accelerations of the wheelsets, yield the dynamic forces due to the passage over the irregularities of the vehicle and the track. The ground vibrations are correlated to these dynamic forces to a certain extent. Some mid-frequency ground vibration amplitudes, however, are higher than expected from the dynamic excitation forces. The experimental observations can be explained by an irregular response to the passage of the static loads, that means the passage of the static loads over an irregular ballast or soil. This correct understanding of the excitation processes is important for the prediction as well as for the mitigation of railway induced ground vibrations.
T2 - X INTERNATIONAL CONFERENCE ON STRUCTURAL DYNAMICS (EURODYN 2017)
KW - Vehicle-track interaction
KW - Ground vibration
KW - Track vibration
KW - Railway measurement campaign
KW - Axle box measurements
PY - 2017
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-420889
DO - https://doi.org/10.1016/j.proeng.2017.09.390
SN - 1877-7058
VL - 199
SP - 2615
EP - 2620
PB - Elsevier
CY - London
AN - OPUS4-42088
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Henning, L. M.
A1 - Müller, J. T.
A1 - Smales, Glen Jacob
A1 - Pauw, Brian Richard
A1 - Schmidt, J.
A1 - Bekheet, M. F.
A1 - Gurlo, A.
A1 - Simon, U.
T1 - Hierarchically porous and mechanically stable monoliths from ordered mesoporous silica and their water filtration potential
N2 - Mechanically stable structures with interconnected hierarchical porosity combine the benefits of both small
and large pores, such as high surface area, pore volume, and good mass transport capabilities. Hence, lightweight micro-/meso-/macroporous monoliths are prepared from ordered mesoporous silica COK-12 by means of spark plasma sintering (SPS, S-sintering) and compared to conventionally (C-) sintered monoliths. A multi-scale model is developed to fit the small angle X-ray scattering data and obtain information on the hexagonal lattice parameters, pore sizes from the macro to the micro range, as well as the dimensions of the silica population. For both sintering techniques, the overall mesoporosity, hexagonal pore ordering, and amorphous character are preserved. The monoliths' porosity (77–49%), mesopore size (6.2–5.2 nm), pore volume (0.50–0.22 g cm-3
), and specific surface area (451–180 m2 g-1) decrease with increasing processing temperature and pressure. While the difference in porosity is enhanced, the
structural parameters between the C-and S-sintered monoliths are largely converging at 900 C, except for the mesopore size and lattice parameter, whose dimensions are more extensively preserved in the
S-sintered monoliths, however, coming along with larger deviations from the theoretical lattice. Their higher mechanical properties (biaxial strength up to 49 MPa, 724 MPa HV 9.807 N) at comparable porosities and ability to withstand ultrasonic treatment and dead-end filtration up to 7 bar allow S-sintered monoliths to reach a high permeance (2634 L m-2 h-1 bar-1), permeability (1.25 x 10^-14 m2), and ability to reduce the chemical oxygen demand by 90% during filtration of a surfactant-stabilized oil in water emulsion, while indicating reasonable resistance towards fouling.
KW - SAXS
KW - Hierarchically porous
KW - Silica
KW - Water filtration
PY - 2022
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-555928
DO - https://doi.org/10.1039/D2NA00368F
SN - 2516-0230
SP - 1
EP - 17
PB - Royal Society of Chemistry
CY - Cambridge
AN - OPUS4-55592
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Tatzel, Michael
A1 - von Blanckenburg, F.
A1 - Oelze, M.
A1 - Bouchez, J.
A1 - Hippler, D.
T1 - Late Neoproterozoic seawater oxygenation by siliceous sponges
N2 - The Cambrian explosion, the rapid appearance of most animal phyla in the geological record, occurred concurrently with bottom seawater oxygenation. Whether this oxygenation Event was triggered through enhanced nutrient supply and organic carbon burial forced by increased continental weathering, or by species engaging in ecosystem engineering, remains a fundamental yet unresolved question. Here we provide evidence for several simultaneous developments that took place over the Ediacaran–Cambrian transition: expansion of siliceous sponges, decrease of the dissolved organic carbon pool, enhanced organic carbon burial, increased phosphorus removal and seawater oxygenation. This evidence is based on Silicon and carbon stable isotopes, Ge/Si ratios, REE-geochemistry and redox-sensitive elements in a chert-shale succession from the Yangtze Platform, China. According to this reconstruction, sponges have initiated seawater oxygenation by redistributing organic carbon oxidation through filtering suspended organic matter from seawater. The resulting increase in dissolved oxygen levels potentially triggered the diversification of eumetazoans.
KW - Oxygenation
KW - Carbon cycle
KW - Silicon stable isotopes
PY - 2017
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-422339
DO - https://doi.org/10.1038/s41467-017-00586-5
SN - 2041-1723
VL - 8
SP - Article 621, 1
EP - 10
AN - OPUS4-42233
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Zscherpel, Uwe
A1 - Schumacher, David
A1 - Redmer, Bernhard
A1 - Ewert, Uwe
A1 - Ullberg, C.
A1 - Weber, N.
A1 - Pantsar, T.
T1 - Digital radiology with photon counting detectors
N2 - The progress in X-ray detector electronics (sensitivity and speed) allows meanwhile fast single photon detection by a matrix detector. Combined photon counting and energy discrimination is implemented in the electronic circuit of each detector pixel. The company XCounter developed detectors based on CdTe single crystals, which can be tiled to larger areas and have a pixel size of 100ìm. The largest area available in beginning of 2014 is 50x75 mm². These detectors have very promising properties, which make them very suitable for NDT applications:
1. A CdTe attenuation layer of 750 µm thickness allows efficient X-ray detection up to ca. 300 keV. In counting mode only photon noise is important; no other detector noise sources need to be considered. There is no Offset signal without radiation.
2. Each of the detector pixels has two energy thresholds. These can be used for dual energy imaging for materials separation. Also the suppression of scattered radiation by energy thresholding will improve the image contrast sensitivity. First experiments will be presented which demonstrate the advantages of this new detector technology over the conventional charge integrating detectors.
A challenge is the development of a modified detector calibration procedure, which becomes critical at longer exposure times.
T2 - ECNDT 2014 - 11th European conference on non-destructive testing
CY - Prague, Czech Republic
DA - 06.10.2014
KW - Materials characterization
KW - Radiographic testing (RT)
KW - Digital detector array
KW - Photo counting
KW - Image quality
KW - Calibration
KW - Dual-energy
KW - Energy discrimination
KW - Digital radiology
KW - Detectors
PY - 2014
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-323063
UR - https://www.ndt.net/?id=16709
SN - 1435-4934
N1 - Geburtsname von Schumacher, David: Walter, D.
-
Birth name of Schumacher, David: Walter, D.
VL - 19
IS - 12
SP - 1
EP - 8
PB - NDT.net
CY - Kirchwald
AN - OPUS4-32306
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Ganose, Alex M.
A1 - Sahasrabuddhe, Hrushikesh
A1 - Asta, Mark
A1 - Beck, Kevin
A1 - Biswas, Tathagata
A1 - Bonkowski, Alexander
A1 - Bustamante, Joana
A1 - Chen, Xin
A1 - Chiang, Yuan
A1 - Chrzan, Daryl C.
A1 - Clary, Jacob
A1 - Cohen, Orion A.
A1 - Ertural, Christina
A1 - Gallant, Max C.
A1 - George, Janine
A1 - Gerits, Sophie
A1 - Goodall, Rhys E. A.
A1 - Guha, Rishabh D.
A1 - Hautier, Geoffroy
A1 - Horton, Matthew
A1 - Inizan, T. J.
A1 - Kaplan, Aaron D.
A1 - Kingsbury, Ryan S.
A1 - Kuner, Matthew C.
A1 - Li, Bryant
A1 - Linn, Xavier
A1 - McDermott, Matthew J.
A1 - Mohanakrishnan, Rohith Srinivaas
A1 - Naik, Aakash A.
A1 - Neaton, Jeffrey B.
A1 - Parmar, Shehan M.
A1 - Persson, Kristin A.
A1 - Petretto, Guido
A1 - Purcell, Thomas A. R.
A1 - Ricci, Francesco
A1 - Rich, Benjamin
A1 - Riebesell, Janosh
A1 - Rignanese, Gian-Marco
A1 - Rosen, Andrew S.
A1 - Scheffler, Matthias
A1 - Schmidt, Jonathan
A1 - Shen, Jimmy-Xuan
A1 - Sobolev, Andrei
A1 - Sundararaman, Ravishankar
A1 - Tezak, Cooper
A1 - Trinquet, Victor
A1 - Varley, Joel B.
A1 - Vigil-Fowler, Derek
A1 - Wang, Duo
A1 - Waroquiers, David
A1 - Wen, Mingjian
A1 - Yang, Han
A1 - Zheng, Hui
A1 - Zheng, Jiongzhi
A1 - Zhu, Zhuoying
A1 - Jain, Anubhav
T1 - Atomate2: Modular workflows for materials science
N2 - High-throughput density functional theory (DFT) calculations have become a vital element of computational materials science, enabling materials screening, property database generation, and training of “universal” machine learning models. While several software frameworks have emerged to support these computational efforts, new developments such as machine learned force fields have increased demands for more flexible and programmable workflow solutions. This manuscript introduces atomate2, a comprehensive evolution of our original atomate framework, designed to address existing limitations in computational materials research infrastructure. Key features include the support for multiple electronic structure packages and interoperability between them, along with generalizable workflows that can be written in an abstract form irrespective of the DFT package or machine learning force field used within them. Our hope is that atomate2's improved usability and extensibility can reduce technical barriers for high-throughput research workflows and facilitate the rapid adoption of emerging methods in computational material science.
KW - Automation
KW - Materials design
KW - DFT workflows
KW - Phonons
KW - Thermal conductivity
KW - Bonding analysis
PY - 2025
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-635759
DO - https://doi.org/10.1039/d5dd00019j
SN - 2635-098X
SP - 1
EP - 30
PB - Royal Society of Chemistry (RSC)
CY - Cambridge
AN - OPUS4-63575
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Hemingway, Jack M.
A1 - Quayle, Heather M.
A1 - Byrne, Cian
A1 - Pulham, Colin R.
A1 - Mondal, Subrata
A1 - Michalchuk, Adam
A1 - Morrison, Carole A.
T1 - Predicting impact sensitivities for an extended set of energetic materials via the vibrational up-pumping model: Molecular-based structure–property relationships identified
N2 - We have applied the vibrational up-pumping model to predict the mechanically-induced impact sensitivities of 33 molecular energetic crystals. Overall, the current model successfully identifies and ranks the compounds that are most sensitive to mechanical initiation, but offers poorer differentiation between compounds with lower sensitivity. Further developments to include the effects of trigger bond activation led to significant improvements in predictive capability. We show that this structure–property model highlights the importance of molecular flexibility in predicting impact sensitivity, and furthermore, we show that the Kier molecular flexibility index, which can be obtained from a SMILES string, offers a simple molecular-based descriptor that goes some way towards predicting the sensitivity of energetic materials.
KW - Vibrational
KW - Pyrazoles
KW - Comprising
KW - Electronic
PY - 2025
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-632651
DO - https://doi.org/10.1039/d5cp00852b
SN - 1463-9076
VL - 27
IS - 22
SP - 11640
EP - 11648
PB - Royal Society of Chemistry (RSC)
CY - Cambridge
AN - OPUS4-63265
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Quackatz, Lukas
A1 - Griesche, Axel
A1 - Kannengießer, Thomas
T1 - Rapid solidification during welding of duplex stainless steels – in situ measurement of the chemical concentration by Laser-Induced Breakdown Spectroscopy (LIBS)
N2 - Duplex stainless steels (DSS) are frequently used, especially in applications requiring high strength combined with high corrosion resistance in aggressive media. Examples include power plant components and maritime structures. During welding of these steels, local variations in chemical composition can occur. This results in ferritization of the material and negatively affects the mechanical properties of the components. In this work, tungsten inert gas (TIG) welding experiments were performed with DSS. Chemical composition analysis was realized in situ by using Laser Induced Breakdown Spectroscopy (LIBS). The aim of the work is to quantitatively measure the chemical composition in the weld seam of various DSS and to identify possible influences of welding parameters on the microstructure of the material. The chemical concentrations of the main alloying elements Cr, Ni, Mn on the surface of the sample during the welding process and the cooling process were measured. Mn and Ni are austenite stabilizers and their content increases during welding by using certain high alloyed filler material. Spectra were recorded every 1.3 s at a spacing of approximately 2 mm. During the cooling process the location of the measurement was not changed. The LIBS method is proofed to be suitable for the quantitative representation of the chemical compositions during the welding process.
T2 - ICASP-6
CY - Le Bischenberg, France
DA - 20.06.2022
KW - LIBS
KW - In situ measurement
KW - Duplex stainless steel
KW - TIG welding
KW - Evaporation
PY - 2023
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-571308
DO - https://doi.org/10.1088/1757-899X/1274/1/012018
VL - 1274
SP - 1
EP - 8
PB - IOP Publishing
CY - Bristol
AN - OPUS4-57130
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Schumm, A.
A1 - Martin, E.
A1 - Beaumont, M.
A1 - Ewert, Uwe
A1 - Kolkoori, Sanjeevareddy
A1 - Zscherpel, Uwe
A1 - Wrobel, Norma
A1 - Redmer, Bernhard
T1 - A comparative study on the performance of digital detector systems for high energy applications
N2 - For cast components reaching or exceeding total material thicknesses of 150mm, high energy sources such as linear accelerators or Betatrons are required in order to obtain reasonable exposure times. In this study, the performance of digital detector systems, involving imaging plates (IP) and digital detector arrays (DDA), was evaluated with respect to the testing class B requirements as formulated in the standard EN ISO 17636-2. As a reference, traditional radiographic film and a Cobalt-60 source was used. With film exposures, testing class B was achieved with Co-60 and Betatron (7.5 MV) at longer exposure times. The preliminary results show that the testing class B was not obtained with the examined digital detector arrays (DDA) and the high resolution imaging plates (IP) , even at 40, 60 and 80 minutes exposure time with a 7.5 MV Betatron. Class A was achieved using high resolution imaging plates with optimized metal filters between object and IPs and a high resolution DDA with intermediate Cu filters. Class A was also achieved applying a DDA with lower basic spatial resolution than required by Table B.13 of EN ISO 17636-2, but using the compensation principle as described in this standard. The next generation of digital detector arrays might potentially be able to obtain class B performance with the expected spatial resolution and sensitivity improvements.
T2 - ECNDT 2014 - 11th European conference on non-destructive testing
CY - Prague, Czech Republic
DA - 06.10.2014
KW - Radiography
KW - Image quality
KW - Betatron
KW - Digital detector array (DDA)
KW - Casting
KW - Standards
KW - High energy radiography
KW - Comparison of detectors
KW - Steel weldment
PY - 2014
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-323075
UR - https://www.ndt.net/?id=16394
SN - 1435-4934
VL - 19
IS - 12
SP - 1
EP - 6
PB - NDT.net
CY - Kirchwald
AN - OPUS4-32307
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Kulla, Hannes
A1 - Greiser, Sebastian
A1 - Benemann, Sigrid
A1 - Rademann, K.
A1 - Emmerling, Franziska
T1 - In Situ Investigation of a Self-Accelerated Cocrystal Formation by Grinding Pyrazinamide with Oxalic Acid
N2 - A new cocrystal of pyrazinamide with oxalic acid was prepared mechanochemically and characterized by PXRD, Raman spectroscopy, solid-state NMR spectroscopy, DTA-TG, and SEM. Based on powder X-ray diffraction data the structure was solved. The formation pathway of the reaction was studied in situ using combined synchrotron PXRD and Raman spectroscopy. Using oxalic acid dihydrate the initially neat grinding turned into a rapid self-accelerated liquid-assisted grinding process by the release of crystallization water. Under these conditions, the cocrystal was formed directly within two minutes.
KW - in situ
KW - cocrystal
KW - mechanochemistry
KW - pyrazinamide
KW - hydrate
PY - 2016
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-372357
DO - https://doi.org/10.3390/molecules21070917
SN - 1420-3049
VL - 21
IS - 7
SP - Article 917, 1
EP - 9
AN - OPUS4-37235
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Fischer, Franziska
A1 - Scholz, G.
A1 - Benemann, Sigrid
A1 - Rademann, K.
A1 - Emmerling, Franziska
T1 - Evaluation of the formation pathways of cocrystal polymorphs in liquid-assisted syntheses
N2 - The synthesis of the polymorphic cocrystal caffeine:anthranilic acid was investigated to obtain a better understanding of the processes leading to the formation of different polymorphic forms. In the case of these cocrystal polymorphs synthesized by liquid-assisted grinding a distinct influence of the dipole moment of the solvent was found. A pre-coordination between the solvent molecules and the caffeine:anthranilic acid cocrystal could be identified in the formation of form II. In the case of form II the solvent can be regarded as a catalyst. The formation pathway of each polymorph was evaluated using synchrotron X-ray diffraction.
KW - cocrystal
KW - synchrotron X-ray diffraction
KW - caffeine
PY - 2014
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-313222
DO - https://doi.org/10.1039/c4ce00472h
SN - 1466-8033
VL - 16
IS - 35
SP - 8272
EP - 8278
CY - London, UK
AN - OPUS4-31322
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Pfeiffer, F.
A1 - Bagyan, I.
A1 - Alfaro Espinoza, Gabriela
A1 - Zamora-Lagos, M.-A.
A1 - Habermann, B.
A1 - Marin-Sanguino, A.
A1 - Oesterhelt, D.
A1 - Kunte, Hans-Jörg
T1 - Revision and reannotation of the Halomonas elongata DSM 2581(T) genome
N2 - The genome of the Halomonas elongata type strain DSM 2581, an industrial producer, was reevaluated using the Illumina HiSeq2500 technology. To resolve duplication-associated ambiguities, PCR products were generated and sequenced. Outside of duplications, 72 sequence corrections were required, of which 24 were point mutations and 48 were indels of one or few bases. Most of these were associated with polynucleotide stretches (poly-T stretch overestimated in 19 cases, poly-C underestimated in 15 cases). These problems may be attributed to using 454 technology for original Genome sequencing. On average, the original genome sequence had only one error in 56 kb. There were 23 frameshift error corrections in the 29 protein-coding genes affected by sequence revision. The genome has been subjected to major reannotation in order to substantially increase the annotation quality.
KW - Frameshift
KW - Genome annotation
KW - Genome sequencing
KW - Halomonas elongata
KW - Halophilic bacteria
KW - Sequence revision
PY - 2017
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-403292
DO - https://doi.org/10.1002/mbo3.465
SN - 2045-8827
VL - 6
IS - 4
SP - Article e465, 1
EP - 6
PB - Wiley
AN - OPUS4-40329
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Kruschwitz, Sabine
T1 - NDT for microstructure and moisture investigation of porous building material
N2 - Non-destructive testing methods are mostly applied and established for the detection of embedded mounting parts or structural defects in building elements. The assessment of the concrete microstructure or microstructural changes like chemical alterations or the formation of microcracks, e.g. due to material aging, freeze-thaw cycles, alkali-silica reaction and ettringite, is not in the focus of ndt research though. Concrete moisture and enhanced salt contents, which usually trigger all chemical microstructural changes, are other material properties, lacking reliable ways of measuring. But, the assessment of such material properties, on the long term also in a depth resolved manner, is definitely important, when the sustainability of our concrete infrastructure buildings shall be evaluated.
New consideration like the potential use of ndt, in particular the combination of different methods and alternate ways of data analysis are subject of research currently undertaken at BAM. These approaches involve for example working towards (i) a deeper understanding of how to measure moisture distributions reliably and follow transport phenomena, (ii) the use of stray phenomena in radar and ultrasound to locate material inhomogeneities or (iii) the application of LIBS for the delineation of diffusion and migration processes but also (iv) the use of new tools for data analysis like data fusion. First results are presented and new ideas discussed.
T2 - NDT-CE 2015 - International symposium non-destructive testing in civil engineering
CY - Berlin, Germany
DA - 15.09.2015
KW - Screed
KW - Moisture
KW - Non-destructive testing
KW - Radar
KW - Microstructure
KW - Monitoring
KW - Concrete deterioration
KW - Cracking
PY - 2015
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-347593
UR - http://www.ndt.net/?id=18354
SN - 1435-4934
VL - 20
IS - 11
SP - 1
EP - 5
PB - NDT.net
CY - Kirchwald
AN - OPUS4-34759
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Würth, Christian
A1 - Geißler, Daniel
A1 - Resch-Genger, Ute
T1 - Quantification of anisotropy-related uncertainties in relative photoluminescence quantum yield measurements of nanomaterials - semiconductor quantum dots and rods
N2 - In order to assess the anisotropy-related uncertainties of relatively determined photoluminescence quantum yields (ΦPL) of molecular emitters and luminescent nanomaterials, we compared ΦPL values measured without and with polarizers using magic angle conditions and studied systematically the dependence of the detected emission intensity on the polarizer settings for samples of varying anisotropy. This includes a dispersion of a spherical quantum dot (QD) with an ideally isotropic emission, a solution of a common small organic dye in a fluid solvent as well as dispersions of elongated quantum dot rods (QDR) with an anisotropic luminescence and a small organic dye in a rigid polymeric matrix, as ideally anisotropic emitter. Our results show that for instruments lacking polarizers, anisotropy-related measurement uncertainties of relative photoluminescence quantum yields can amount to more than 40%, with the size of these systematic errors depending on the difference in emission anisotropy between the sample and the standard.
KW - Photoluminescence
KW - Quantum Yield
KW - Emission Anisotropy
KW - Quantum Dot Rod
KW - Quantum Dot
KW - Dye
PY - 2015
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-325240
DO - https://doi.org/10.1515/zpch-2014-0626
SN - 0942-9352
SN - 2196-7156
SN - 0044-3336
SN - 0044-3328
VL - 229
IS - 1-2
SP - 153
EP - 165
PB - Oldenbourg
CY - München
AN - OPUS4-32524
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Guehrs, E.
A1 - Schneider, M.
A1 - Günther, Ch. M.
A1 - Hessing, P.
A1 - Heitz, K.
A1 - Wittke, D.
A1 - López-Serrano Oliver, Ana
A1 - Jakubowski, Norbert
A1 - Plendl, J.
A1 - Eisebitt, S.
A1 - Haase, A.
T1 - Quantification of silver nanoparticle uptake and distribution within individual human macrophages by FIB/SEM slice and view
N2 - Quantification of nanoparticle (NP) uptake in cells or tissues is very important for safety assessment. Often, electron microscopy based approaches are used for this purpose, which allow imaging at very high resolution. However, precise quantification of NP numbers in cells and tissues remains challenging. The aim of this study was to present a novel approach, that combines precise quantification of NPs in individual cells together with high resolution imaging of their intracellular distribution based on focused ion beam/ scanning electron microscopy (FIB/SEM) slice and view approaches.
KW - Nanoparticles
KW - FIB/SEM slice and view
KW - Absolute dose
KW - Cellular internalization
KW - Macrophage
PY - 2017
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-400626
DO - https://doi.org/10.1186/s12951-017-0255-8
SN - 1477-3155
VL - 15
SP - Article 21, 1
EP - 11
AN - OPUS4-40062
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Wang, X.
A1 - Pauli, Jutta
A1 - Niessner, R.
A1 - Resch-Genger, Ute
A1 - Knopp, D.
T1 - Gold nanoparticle-catalyzed uranine reduction for signal amplification in fluorescent assays for melamine and aflatoxin B1
N2 - A multifunctional fluorescence platform has been constructed based on gold nanoparticle (AuNP)-catalyzed uranine reduction. The catalytic reduction of uranine was conducted in aqueous solution using AuNPs as nanocatalyst and sodium borohydride as reducing reagent, which was monitored by fluorescence and UV-vis spectroscopy. The reaction rate was highly dependent on the concentration, size and dispersion state of AuNPs. When AuNPs aggregated, their catalytic ability decreased, and thereby a label-free fluorescent assay was developed for the detection of melamine, which can be used for melamine determination in milk. In addition, a fluorescent immunoassay for aflatoxin B1 (AFB1) was established using the catalytic reaction for signal amplification based on target-induced concentration change of AuNPs, where AFB1-BSA-coated magnetic beads and anti-AFB1 antibody-conjugated AuNPs were employed as capture and signal probe, respectively. The detection can be accomplished in 1 h and acceptable recoveries in spiked maize samples were achieved. The developed fluorescence system is simple, sensitive and specific, which could be used for the detection of a wide range of analytes.
PY - 2015
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-347677
DO - https://doi.org/10.1039/c5an01300c
SN - 0003-2654
SN - 1364-5528
VL - 140
IS - 21
SP - 7305
EP - 7312
PB - Royal Society of Chemistry
CY - Cambridge
AN - OPUS4-34767
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Szczerba, Wojciech
A1 - Zukrowski, J.
A1 - Przybylski, M.
A1 - Sikora, M.
A1 - Safonova, O.
A1 - Shmeliov, A.
A1 - Nicolosi, V.
A1 - Schneider, M.
A1 - Granath, T.
A1 - Oppmann, M.
A1 - Straßer, M.
A1 - Mandel, K.
T1 - Pushing up the magnetisation values for iron oxide nanoparticles via zinc doping: X-ray studies on the particle's sub-nano structure of different synthesis routes
N2 - The maximum magnetisation (saturation magnetisation) obtainable for iron oxide nanoparticles can be increased by doping the nanocrystals with non-magnetic elements such as zinc. Herein, we closely study how only slightly different synthesis approaches towards such doped nanoparticles strongly influence the resulting sub-nano/atomic structure. We compare two co-precipitation approaches, where we only vary the base (NaOH versus NH3), and a thermal decomposition route. These methods are the most commonly applied ones for synthesising doped iron oxide nanoparticles. The measurable magnetisation change upon zinc doping is about the same for all systems. However, the sub-nano structure, which we studied with Mössbauer and X-ray absorption near edge spectroscopy, differs tremendously. We found evidence that a much more complex picture has to be drawn regarding what happens upon Zn doping compared to what textbooks tell us about the mechanism. Our work demonstrates that it is crucial to study the obtained structures very precisely when “playing” with the atomic order in iron oxide nanocrystals.
KW - Magnetic nanoparticles
KW - Zinc ferrite
KW - magnetic saturation
KW - Mössbauer
KW - XAFS
KW - Synthesis
KW - XRD
PY - 2016
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-379583
DO - https://doi.org/10.1039/C6CP04221J
VL - 18
SP - 25221
EP - 25229
PB - RSC Publishing
AN - OPUS4-37958
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Geißler, Daniel
A1 - Gollwitzer, C.
A1 - Sikora, A.
A1 - Minelli, C.
A1 - Krumrey, M.
A1 - Resch-Genger, Ute
T1 - Effect of fluorescent staining on size measurements of polymeric nanoparticles using DLS and SAXS
N2 - The influence of fluorescence on nanoparticle size measurements using dynamic light scattering (DLS) and small angle X-ray scattering (SAXS) was investigated. For this purpose, two series of 100 nm-sized polymer nanoparticles stained with different concentrations of the fluorescent dyes DY555 and DY680 were prepared, absorbing/emitting at around 560 nm/590 nm and 695 nm/715 nm, respectively. SAXS measurements of these particle series and a corresponding blank control (without dye) revealed similar sizes of all particles within an uncertainty of 1 nm. DLS measurements carried out at three different laboratories using four different DLS instruments and two different laser wavelengths, i.e., 532 nm and 633 nm, revealed also no significant changes in size (intensity-weighted harmonic mean diameter, ZAverage) and size distribution (polydispersity index, PI) within and between the two dye-stained particle series and the blank sample. Nevertheless, a significant decrease of the detected correlation coefficients was observed with increasing dye concentration, due to the increased absorption of the incident light and thus, less coherent light scattering. This effect was wavelength dependent, i.e. only measurable for the dye-stained particles that absorb at the laser wavelength used for the DLS measurements.
PY - 2015
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-349684
DO - https://doi.org/10.1039/C5AY02005K
SN - 1759-9660
SN - 1759-9679
VL - 7
IS - 23
SP - 9785
EP - 9790
PB - RSC Publ.
CY - Cambridge
AN - OPUS4-34968
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Andrae, K.
A1 - Merkel, Stefan
A1 - Durmaz, V.
A1 - Fackeldey, K.
A1 - Köppen, Robert
A1 - Weber, M.
A1 - Koch, Matthias
T1 - Investigation of the ergopeptide epimerization process
N2 - Ergopeptides, like ergocornine and a-ergocryptine, exist in an S- and in an R-configuration. Kinetic experiments imply that certain configurations are preferred depending on the solvent. The experimental methods are explained in this article. Furthermore, computational methods are used to understand this configurational preference. Standard quantum chemical methods can predict the favored configurations by using minimum energy calculations on the potential energy landscape. However, the explicit role of the solvent is not revealed by this type of methods. In order to better understand its influence, classical mechanical molecular simulations are applied. It appears from our research that 'folding' the ergopeptide molecules into an intermediate state (between the S- and the R-configuration) is mechanically hindered for the preferred configurations.
KW - Ergopeptide
KW - Epimerization
KW - Hybrid monte carlo
KW - Molecular dynamics
KW - Conformation
KW - Quantum mechanics
PY - 2014
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-324632
DO - https://doi.org/10.3390/computation2030102
SN - 2079-3197
VL - 2
IS - 3
SP - 102
EP - 111
PB - MDPI
CY - Basel
AN - OPUS4-32463
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Manke, I.
A1 - Kardjilov, N.
A1 - Schäfer, R.
A1 - Hilger, A.
A1 - Grothausmann, R.
A1 - Strobl, M.
A1 - Dawson, M.
A1 - Grünzweig, C.
A1 - Tötzke, C.
A1 - David, C.
A1 - Kupsch, Andreas
A1 - Lange, Axel
A1 - Hentschel, Manfred P.
A1 - Banhart, J.
T1 - Three-dimensional imaging of magnetic domains with neutron grating interferometry
N2 - This paper gives a brief overview on3D imaging of magnetic domains with shearing grating neutron tomography. We investigated the three-dimensional distribution of magnetic domain walls in the bulk of a wedge-shaped FeSi single crystal. The width of the magnetic domains wasanalyzed at different locations within the crystal. Magnetic domains close to the tip of the wedge are much smaller than in the bulk. Furthermore, the three-dimensional shape of individual domains wasinvestigated. We discuss prospects and limitations of the applied measurement technique.
KW - Neutron imaging
KW - Tomography
KW - Magnetic domains
KW - Grating interferometry
KW - Darkfield imaging
KW - Shearing gratings
KW - Talbot-Lau
KW - Three-dimensional data quantification
KW - Tomographic reconstruction
PY - 2015
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-341919
DO - https://doi.org/10.1016/j.phpro.2015.07.057
SN - 1875-3892
VL - 69
SP - 404
EP - 412
PB - Elsevier B.V.
CY - Amsterdam
AN - OPUS4-34191
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Rabe, Sebastian
A1 - Chuenban, Yuttapong
A1 - Schartel, Bernhard
T1 - Exploring the Modes of Action of Phosphorus-Based Flame Retardants in Polymeric Systems
N2 - Phosphorus-based flame retardants were incorporated into different, easily preparable matrices, such as polymeric thermoset resins and paraffin as a proposed model for polyolefins and investigated for their flame retardancy performance. The favored mode of action of each flame retardant was identified in each respective system and at each respective concentration. Thermogravimetric analysis was used in combination with infrared spectroscopy of the evolved gas to determine the pyrolysis behavior, residue formation and the release of phosphorus species. Forced flaming tests in the cone calorimeter provided insight into burning behavior and macroscopic residue effects. The results were put into relation to the phosphorus content to reveal correlations between phosphorus concentration in the gas phase and flame inhibition performance, as well as phosphorus concentration in the residue and condensed phase activity. Total heat evolved (fire load) and peak heat release rate were calculated based on changes in the effective heat of combustion and residue, and then compared with the measured values to address the modes of action of the flame retardants quantitatively. The quantification of flame inhibition, charring, and the protective layer effect measure the non-linear flame retardancy effects as functions of the phosphorus concentration. Overall, this screening approach using easily preparable polymer systems provides great insight into the effect of phosphorus in different flame retarded polymers, with regard to polymer structure, phosphorus concentration, and phosphorus species.
KW - Flame retardants
KW - Flame inhibition
KW - Cone calorimeter
KW - Aluminum diethyl phosphinate
KW - Polyester
KW - PMMA
KW - Epoxy resin
KW - Red phosphorus
KW - BDP
PY - 2017
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-402731
DO - https://doi.org/10.3390/ma10050455
SN - 1996-1944
VL - 10
IS - 5
SP - 455, 1
EP - 455, 23
PB - MDPI
AN - OPUS4-40273
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Matzen, Melissa
A1 - Kandola, B.
A1 - Huth, Christian
A1 - Schartel, Bernhard
T1 - Influence of flame retardants on the melt dripping behaviour of thermoplastic polymers
N2 - Melt flow and dripping of the pyrolysing polymer melt can be both a benefit and a detriment during a fire. In several small-scale fire tests addressing the ignition of a defined specimen with a small ignition source, well-adjusted melt flow and dripping are usually beneficial to pass the test. The presence of flame retardants often changes the melt viscosity crucially. The influence of certain flame retardants on the dripping behaviour of four commercial polymers, poly(butylene terephthalate) (PBT), polypropylene (PP), polypropylene modified with ethylene-propylene rubber (PP-EP) and polyamide 6 (PA 6), is analysed based on an experimental monitoring of the mass loss due to melt dripping, drop size and drop temperature as a function of the furnace temperature applied to a rod-shaped specimen. Investigating the thermal transition (DSC), thermal and thermo-oxidative decomposition, as well as the viscosity of the polymer and collected drops completes the investigation. Different mechanisms of the flame retardants are associated with their influence on the dripping behaviour in the UL 94 test. Reduction in decomposition temperature and changed viscosity play a major role. A flow limit in flame-retarded PBT, enhanced decomposition of flame-retarded PP and PP-EP and the promotion of dripping in PA 6 are the salient features discussed.
KW - Fire retardant
KW - Viscosity
KW - Melt dripping
KW - Reaction-to-small-flame
KW - UL 94
PY - 2015
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-338941
DO - https://doi.org/10.3390/ma8095267
SN - 1996-1944
VL - 8
IS - 9
SP - 5621
EP - 5646
PB - MDPI
CY - Basel
AN - OPUS4-33894
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Büchner, T.
A1 - Drescher, D.
A1 - Merk, V.
A1 - Traub, Heike
A1 - Guttmann, P.
A1 - Werner, St.
A1 - Jakubowski, Norbert
A1 - Schneider, G.
A1 - Kneipp, J.
T1 - Biomolecular environment, quantification, and intracellular interaction of multifunctional magnetic SERS nanoprobes
N2 - Multifunctional composite nanoprobes consisting of iron oxide nanoparticles linked to silver and gold nanoparticles, Ag–Magnetite and Au–Magnetite, respectively, were introduced by endocytic uptake into cultured fibroblast cells. The cells containing the non-toxic nanoprobes were shown to be displaceable in an external magnetic field and can be manipulated in microfluidic channels. The distribution of the composite nanostructures that are contained in the endosomal system is discussed on the basis of surfaceenhanced Raman scattering (SERS) mapping, quantitative laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) micromapping, and cryo soft X-ray tomography (cryo soft-XRT). Cryo soft-XRT of intact, vitrified cells reveals that the composite nanoprobes form intra-endosomal aggregates. The nanoprobes provide SERS signals from the biomolecular composition of their surface in the endosomal environment. The SERS data indicate the high stability of the nanoprobes and of their plasmonic properties in the harsh environment of endosomes and lysosomes. The spectra point at the molecular composition at the surface of the Ag–Magnetite and Au–Magnetite nanostructures that is very similar to that of other Composite structures, but different from the composition of pure silver and gold SERS nanoprobes used for intracellular investigations. As shown by the LA-ICP-MS data, the uptake efficiency of the magnetite composites is approximately two to three times higher than that of the pure gold and silver nanoparticles.
KW - Nanoparticles
KW - SERS
KW - Cell
KW - LA-ICP-MS
KW - X-ray tomography
PY - 2016
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-371811
DO - https://doi.org/10.1039/c6an00890a
SN - 0003-2654
VL - 141
IS - 17
SP - 5096
EP - 5106
PB - Royal Society of Chemistry
CY - Cambridge, UK
AN - OPUS4-37181
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Luong, Thi Mai Hoa
A1 - Zabel, V.
A1 - Lorenz, W.
A1 - Rohrmann, R.G.
T1 - Non-destructive assessment of the axial stress state in iron and steel truss structures by dynamic measurements
N2 - This paper is concerned with the inverse identification of the stress state in axially loaded slender members of iron and steel truss structures using measured dynamic data. A methodology is proposed based on the finite element model updating coupled with nature-inspired optimization techniques, in particular the particle swarm optimization. The numerical model of truss structures is calibrated using natural frequencies and mode shapes from vibration tests, as well as additional information of the axial forces in selected truss members based on the experimentally identified modal parameters. The results of the identification are the axial forces or corresponding stresses in truss structures and the joint rigidity in relation to pinned and rigid conditions. Attention is given to several examined aspects, including the effects of the axial tensile and compressive forces on the dynamic responses of trusses, mode pairing criteria, as well as modeling assumptions of joints and the use of a joint rigidity parameter. Considering the pairing of modes, it is performed by adapting an enhanced modal assurance criterion that allows the selection of desired clusters of degrees-of-freedom. Thus, information extracted from the measurements related to specific modes is utilized in a more beneficial way. For modeling of joints, the numerical model of a truss structure includes rotational springs of variable stiffness to represent semi-rigid connections. Moreover, a fixity factor is introduced for practical estimation of the joint flexibility. The effectiveness of the proposed methodology is demonstrated by case studies involving simulated and laboratory experimental data.
T2 - X International Conference on Structural Dynamics, EURODYN 2017
DA - 10.09.2017
KW - Axial force
KW - Dynamic test
KW - Model updating
KW - Optimization technique
KW - Truss structures
KW - Modal parameters
PY - 2017
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-419311
DO - https://doi.org/10.1016/j.proeng.2017.09.447
SN - 1877-7058
VL - 199
SP - 3380
EP - 3385
PB - Elsevier
AN - OPUS4-41931
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Schlick-Hasper, Eva
A1 - Seidler, Oliver
A1 - Goedecke, Thomas
A1 - Kraume, M.
T1 - Helium leak testing of dangerous goods packagings
N2 - The International Dangerous Goods Regulations prescribe the immersion under water method (“bubble test”) as standard method for the leakproofness test of dangerous goods packagings. But this test procedure acts as a test method for leak localisation, not for quantitative leakage rates measurement. Additionally, the sensitivity in detecting leaks of small diameters is restricted, depending on the test liquid and the test pressure. The bubble test is not suitable for a comparison with quantitative limit leakage rates based on realistic transport conditions. This is especially important when estimating the risk of the formation of an explosive atmosphere during the intercontinental carriage of dangerous goods packagings in freight containers. To compare measured leakage rates with limit leakage rates, a quantitative leak testing procedure is required. Therefore a new approach for dangerous goods packagings is implemented: The pressure technique by accumulation using Helium as a tracer gas. This work presents the test equipment necessary for the quantitative measurement of Helium leakage rates through closures of different kinds of dangerous goods packagings. The essential steps to achieve good repeatable results are: A controlled Helium filling process to reach a defined test pressure in the test sample, a sufficient homogenisation of the Helium-air-mixture inside the test sample and the ensuring of a constant pressure level of the test sample during the test. The Helium loss rate of the accumulation chamber has to be measured separately to receive a correction factor for the measured leakage rates. Different constructional measures are introduced to prevent a disturbing influence of the Helium leakage rate of the filling valves on the measurement results. Methods to estimate the disturbing effect of Helium permeation through permeable parts of the test sample are also presented. As a supporting method for the experimental investigations the Helium sniffer test can be applied. This practical application-oriented advice can enable other users to establish a pressure technique by accumulation for their own technical field.
T2 - 19th World Conference on Non-Destructive Testing
CY - Munich, Germany
DA - 13.06.2016
KW - Überdruckverfahren
KW - Gefahrgutverpackungen
KW - Dichtheit
KW - Helium
KW - Dangerous goods packagings
KW - Leakproofness
KW - Helium
KW - Pressure technique
PY - 2016
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-371376
UR - http://ndt.net/?id=19785
SN - 1435-4934
VL - 21
IS - 7
SP - 1
EP - 10
PB - NDT.net
CY - Kirchwald
AN - OPUS4-37137
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Wiedensohler, A.
A1 - Wiesner, A.
A1 - Weinhold, K.
A1 - Birmili, W.
A1 - Herrmann, M.
A1 - Merkel, M.
A1 - Müller, T.
A1 - Pfeifer, S.
A1 - Schmidt, A.
A1 - Tuch, T.
A1 - Velarde, F.
A1 - Quincey, P.
A1 - Seeger, Stefan
A1 - Nowak, A.
T1 - Mobility particle size spectrometers: Calibration procedures and measurement uncertainties
N2 - Mobility particle size spectrometers (MPSS) belong to the essential instruments in aerosol science that determine the particle number size distribution (PNSD)in the submicrometer size range. Following calibration procedures and target uncertainties against standards and reference instruments are suggested for a complete MPSS quality assurance program: a) calibration of the CPC counting efficiency curve (within 5% for the plateau counting efficiency; within 1 nm for the 50% detection efficiency diameter), b) sizing calibration of the MPSS, using a certified polystyrene latex (PSL) particle size standard at 203 nm (within 3%), c) intercomparison of the PNSD of the MPSS (within 10% and 20% of the dN/dlogDP concentration for the particle size range 20 – 200 nm and 200 to 800 nm, respectively), and d) intercomparison of the integral PNC of the MPSS (within 10%). Furthermore, following measurement uncertainties have been investigated: a) PSL particle size standards in the range from 100-500nm match within 1% after sizing calibration at 203 nm. b) Bipolar diffusion chargers based on the radioactive nuclides Kr85, Am241 and Ni63 and a new ionizer based on corona discharge follow the recommended bipolar charge distribution, while soft X-ray-based charges may alter faster than expected. c) The use of a positive high voltage supply show a 10% better performance than a negative one. d) The intercomparison of the integral PNC of an MPSS against the total number concentration is still within the target uncertainty at an ambient pressure of approximately 500 hPa.
KW - Measurement uncertainties
KW - Mobility particle size spectrometer (MPPS)
KW - Condensation particle counter (CPC)
KW - Calibration
PY - 2017
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-425060
DO - https://doi.org/10.1080/02786826.2017.1387229
SN - 1521-7388
VL - 52
IS - 2
SP - 146
EP - 164
PB - Tailor & Francis
CY - USA
AN - OPUS4-42506
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Swaraj, S.
A1 - Dietrich, Paul
A1 - Unger, Wolfgang
T1 - Simultaneous surface and bulk sensitive XAS measurements of magnetic particle clusters
N2 - Magnetic iron oxide nanoparticle clusters (mnpc) coated with organic stabilizers were investigated using scanning transmission x-ray microscopy (STXM). Simultaneous surface and bulk sensitive Fe L3 edge absorption spectra, obtained using a photomultiplier tube and a channeltron, were used to detect subtle changes in the oxidation state in the surface and bulk of Iron Oxide mnpc.
The effectiveness of this mode of STXM operation is demonstrated for These nanoparticle clusters.
T2 - X-Ray Microscopy Conference 2016 (XRM 2016)
CY - Oxford, UK
DA - 15.08.2016
KW - Scanning transmission x-ray microscopy (STXM)
KW - Magnetic nanoparticles
KW - Fe L3 edge absorption spectra
PY - 2017
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-435907
UR - http://iopscience.iop.org/article/10.1088/1742-6596/849/1/012014/meta
DO - https://doi.org/10.1088/1742-6596/849/1/012014
VL - 849
SP - 012014, 1
EP - 012014, 4
PB - IOP Publishing
AN - OPUS4-43590
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Kaur, I.
A1 - Ellis, L.-J.
A1 - Romer, I.
A1 - Tantra, R.
A1 - Carriere, M.
A1 - Allard, S.
A1 - Mayne-L'Hermite, M.
A1 - Minelli, C.
A1 - Unger, Wolfgang
A1 - Potthoff, A.
A1 - Rades, Steffi
A1 - Valsami-Jones, E.
T1 - Dispersion of nanomaterials in aqueous media: Towards protocol optimization
N2 - The sonication process is commonly used for de-agglomerating and dispersing nanomaterials in aqueous based media, necessary to improve homogeneity and stability of the suspension. In this study, a systematic step-wise approach is carried out to identify optimal sonication conditions in order to achieve a stable dispersion. This approach has been adopted and shown to be suitable for several nanomaterials (cerium oxide, zinc oxide, and carbon nanotubes) dispersed in deionized (DI) water. However, with any change in either the nanomaterial type or dispersing medium, there needs to be optimization of the basic protocol by adjusting various factors such as sonication time, power, and sonicator type as well as temperature rise during the process. The approach records the dispersion process in detail. This is necessary to identify the time Points as well as other above-mentioned conditions during the sonication process in which there may be undesirable changes, such as damage to the particle surface thus affecting surface properties. Our goal is to offer a harmonized approach that can control the Quality of the final, produced dispersion. Such a guideline is instrumental in ensuring dispersion quality repeatability in the nanoscience community, particularly in the field of nanotoxicology.
KW - Dispersion of nanomaterials
KW - Aqueous media
KW - Protocol development
PY - 2017
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-435886
UR - https://www.jove.com/video/56074
DO - https://doi.org/10.3791/56074
SN - 1940-087X
IS - 130
SP - e560741, 1
EP - e560741, 23
PB - MyJove Corp.
CY - Cambridge, MA, USA
AN - OPUS4-43588
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Haferkamp, Sebastian
A1 - Fischer, Franziska
A1 - Kraus, Werner
A1 - Emmerling, Franziska
T1 - Mechanochemical Knoevenagel condensation investigated in situ
N2 - The mechanochemical Knoevenagel condensation of malononitrile with p-nitrobenzaldehyde was studied in situ using a tandem approach. X-ray diffraction and Raman spectroscopy were combined to yield time-resolved information on the milling process. Under solvent-free conditions, the reaction leads to a quantitative conversion to p-nitrobenzylidenemalononitrile within 50 minutes. The in situ data indicate that the process is fast and proceeds under a direct conversion. After stopping the milling process, the reaction continues until complete conversion. The continuous and the stopped milling process both result in crystalline products suitable for single crystal X-ray diffraction.
KW - Mechanochemistry
KW - Ball milling
KW - C–C coupling
KW - In situ
KW - Knoevenagel condensation
PY - 2017
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-425388
DO - https://doi.org/10.3762/bjoc.13.197
VL - 13
SP - 2010
EP - 2014
PB - Beilstein-Institut
AN - OPUS4-42538
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Durlo Tambara, Luís Urbano
A1 - Hirsch, A.
A1 - Dehn, F.
A1 - Gluth, Gregor
T1 - Carbonation resistance of alkali-activated GGBFS/calcined clay concrete under natural and accelerated conditions
N2 - The carbonation resistance of alkali-activated materials (AAMs) is a crucial parameter for their applicability in concrete construction, yet the parameters influencing it are insufficiently understood to date. In the present study, the carbonation resistance of alkali-activated concretes with varying fractions of ground granulated blast furnace slag (GGBFS) and calcined clay (i.e., high, intermediate, and low Ca contents) were assessed under natural and accelerated conditions. Corresponding hardened AAM pastes were studied using X-ray diffraction, thermogravimetry, Raman microscopy, and mercury intrusion porosimetry. The carbonation resistance of the concretes at natural CO2 concentration depended principally on their water/(CaO + MgOeq + Na2Oeq + K2Oeq) ratio. The remaining variability for similar ratios was caused by differences between the pore structures of the AAMs. For concrete with favorable water/(CaO + MgOeq + Na2Oeq + K2Oeq) ratio and pore structure, the carbonation resistance was comparable to that of Portland cement concrete. The relationship between carbonation coefficients obtained under accelerated and natural conditions differed for concretes with high and low fractions of calcined clay, indicating that accelerated carbonation testing is less suitable to study the carbonation of low-Ca AAMs.
KW - Alkali-activated materials
KW - Carbonation
KW - Calcined clay
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-610747
DO - https://doi.org/10.1016/j.conbuildmat.2024.138351
SN - 1879-0526
VL - 449
SP - 1
EP - 14
PB - Elsevier
CY - Amsterdam
AN - OPUS4-61074
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Liehr, Sascha
A1 - Breithaupt, Mathias
A1 - Krebber, Katerina
T1 - Distributed humidity sensing in PMMA optical fibers at 500 nm and 650 nm wavelengths
N2 - Distributed measurement of humidity is a sought-after capability for various fields of application, especially in the civil engineering and structural health monitoring sectors. This article presents a method for distributed humidity sensing along polymethyl methacrylate (PMMA) polymer optical fibers (POFs) by analyzing wavelength-dependent Rayleigh backscattering and attenuation characteristics at 500 nm and 650 nm wavelengths. Spatially resolved humidity sensing is obtained from backscatter traces of a dual-wavelength optical time domain reflectometer (OTDR). Backscatter dependence, attenuation dependence as well as the fiber length change are characterized as functions of relative humidity. Cross-sensitivity effects are discussed and quantified. The evaluation of the humidity-dependent backscatter effects at the two wavelength measurements allows for distributed and unambiguous measurement of relative humidity. The technique can be readily employed with low-cost standard polymer optical fibers and commercial OTDR devices.
KW - Optical fiber sensor
KW - Humidity sensor
KW - Distributed sensor
KW - Polymer optical fiber
KW - Rayleigh scattering
PY - 2017
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-396363
UR - http://www.mdpi.com/1424-8220/17/4/738
DO - https://doi.org/10.3390/s17040738
SN - 1424-8220
VL - 17
IS - 4
SP - Article 738, 1
EP - 12
PB - MDPI
CY - Basel, Switzerland
AN - OPUS4-39636
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Tang, S.
A1 - Wachtendorf, Volker
A1 - Klack, Patrick
A1 - Qian, Lijun
A1 - Dong, Y.
A1 - Schartel, Bernhard
T1 - Enhanced flame-retardant effect of montmorillonite/phosphaphenanthrene compound in an epoxy thermoset
N2 - A phosphaphenanthrene and triazinetrione group containing flame retardant (TAD) is combined with organically modified montmorillonite (OMMT) in epoxy resin thermosets (EP) to improve the performance of the flame-retardant system. When only 1 wt% OMMT/4 wt% TAD is introduced into the EP, the limited oxygen index (LOI) rises from 26% to 36.9% and a V-0 rating is achieved in a UL 94 test. The decomposition and pyrolysis products in the gas phase and condensed phase were characterized using thermogravimetry-Fourier transform infrared spectroscopy (TG-FTIR). The influence on the decomposition of EP, such as the increase in char yield, is limited with the incorporation of OMMT; a large amount of the phosphorus is released into the gas phase. The flame-retardant effect evaluation based on cone calorimeter data testified that OMMT improves the protective-barrier effect of the fire residue of OMMT/TAD/EP on the macroscopic scale, while TAD mainly causes flame inhibition. The fire residues showed a corresponding macroscopic appearance (digital photo) and microstructure (scanning electron microscope [SEM] results). The protective barrier effect of OMMT and the flame-inhibition effect of TAD combined to exert a superior flame-retardant effect, resulting in sufficient flame-retardant performance of OMMT/TAD/EP
KW - Flame retardant
KW - Nanocomposite
KW - DOPO
KW - Thermoset
KW - Epoxy resin
KW - TG-FTIR
PY - 2017
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-388865
DO - https://doi.org/10.1039/c6ra25070j
SN - 2046-2069
VL - 7
IS - 2
SP - 720
EP - 728
AN - OPUS4-38886
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Niederleithinger, Ernst
A1 - Abraham, O.
A1 - Mooney, M.
T1 - Geophysical methods in civil engineering: Overview and new concepts
N2 - Geophysical methods have been used in civil engineering for decades. The main field of application is - to no surprise – in geotechnical projects from site characterization to foundation quality assurance. For more than 25 years, ground penetrating radar (GPR) and seismic methods have found applications in structural engineering. Recently introduced geophysical methods have been adopted to ultrasonic investigations in various fields. They help to improve the quality of structural imaging and to detect small changes in concrete. An overview of the history and current use of geophysics in civil engineering is given. Selected examples of new concepts include advances in wave based imaging, quality assurance for foundations, detecting small changes in concrete as well as moisture and corrosion detection are discussed.
T2 - NDT-CE 2015 - International symposium non-destructive testing in civil engineering
CY - Berlin, Germany
DA - 15.09.2015
KW - Nondestructive testing
KW - Civil engineering
KW - Geophysics
PY - 2015
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-344666
UR - https://www.ndt.net/?id=18260
SN - 1435-4934
VL - 20
IS - 11
SP - 1
EP - 6
PB - NDT.net
CY - Kirchwald
AN - OPUS4-34466
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Niederleithinger, Ernst
A1 - Wolf, Julia
A1 - Mielentz, Frank
A1 - Wiggenhauser, Herbert
T1 - Using embedded ultrasonic sensors for active and passive concrete monitoring
N2 - Challenging new constructions and ageing infrastructure are increasing the demand for permanent monitoring of loads and condition. Various methods and sensors are used for this purpose. But the technologies available today have difficulties in detecting slowly progressing locally confined damages. Extensive investigations or instrumentations are required so far for this purpose. In this study we present new sensors and data processing methods for ultrasonic transmission, which can be used for non-destructive long term monitoring of concrete. They can be mounted during construction or thereafter. Larger volumes can be monitored by a limited number of sensors for changes of material properties. The principles of ultrasonic transmission and influencing factors are presented. This latter include load, damages as well as environmental parameters as temperature or moisture. Various methods for data processing, e. g. coda wave interferometry are introduced. They allow the detection of very small changes in the medium. The embedded sensors are shown including mounting and operation. Application examples so far include small scale laboratory freeze-thaw experiments, localizing loads in larger concrete models, monitoring load effects on real structures as well as detecting acoustic events. Some sensors are operating already for several years. The sensors can be used as transmitter or receivers or switched between both roles. While most of the previous experiments have been active (at least one sensor serving as transmitter), new studies show that the sensors are useful as well for passive measurements, e. g. in acoustic emission or time reversal experiments. Besides application in civil engineering our setups can also be used for model studies in geosciences.
T2 - NDT-CE 2015 - International symposium non-destructive testing in civil engineering
CY - Berlin, Germany
DA - 15.09.2015
KW - SHM
KW - Monitoring
KW - Ultrasound concrete
KW - Embedded sensors
PY - 2015
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-344652
UR - http://www.ndt.net/?id=18408
SN - 1435-4934
VL - 20
IS - 11
SP - 1
EP - 4
PB - NDT.net
CY - Kirchwald
AN - OPUS4-34465
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Heinrich, Thomas
A1 - Traulsen, Christoph Hans-Henning
A1 - Darlatt, Erik
A1 - Richter, S.
A1 - Poppenberg, J.
A1 - Traulsen, N.L.
A1 - Linder, I.
A1 - Lippitz, Andreas
A1 - Dietrich, Paul
A1 - Dib, B.
A1 - Unger, Wolfgang
A1 - Schalley, C.A.
T1 - The versatility of 'Click' reactions at surfaces: Molecular recognition at interfaces
N2 - In order to investigate molecular recognition on surfaces, an azide-functionalized monolayer was deposited on gold. The monolayer was characterized by X-ray photoelectron spectroscopy (XPS) and angle-resolved near-edge X-ray absorption fine structure (NEXAFS) experiments and the decomposition of the azide upon irradiation with X-ray beams was investigated. Subsequently, various alkyne-functionalized host and guest molecules were attached to the azide by 1,3-dipolar cycloaddition. These modified surfaces and their host–guest chemistry were analysed by XPS and angle-resolved NEXAFS. The reversibility of guest binding was shown for one example as a proof of principle.
KW - 'Click' reaction
KW - Azide-terminated surfaces
KW - SAMs
KW - Host guest molecules
KW - Molecular recognition at interfaces
PY - 2014
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-306463
DO - https://doi.org/10.1039/C4RA01730G
SN - 2046-2069
VL - 4
IS - 34
SP - 17694
EP - 17702
PB - RSC Publishing
CY - London
AN - OPUS4-30646
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Fiedler Bremer, C.
A1 - Scholz, R.
A1 - Myslicki, S.
A1 - Starke, P.
A1 - Boller, C.
A1 - Walther, F.
A1 - Krause, Martin
T1 - NDT-based characteriazation of timber and vulcanized fiber for civil infrastructure
N2 - The paper addresses beech wood as well as vulcanized fiber and discusses the results obtained when using acoustic emission and thermography as non-destructive testing techniques along tensile and load increase fatigue tests to characterize the wooden material’s behavior under increasing fatigue loads to get enhanced information regarding the fatigue behavior of both materials. Reference is mainly made to the materials’ anisotropic and microstructural behavior and what implications this has with respect to the materials’ strength. The influence of moisture is discussed, as well as parameters that may deserve monitoring in the sense of structural health monitoring to be applied in timber structures in general.
T2 - NDT-CE 2015 - International symposium non-destructive testing in civil engineering
CY - Berlin, Germany
DA - 15.09.2015
KW - Ermüdung
KW - Belastungsversuch
KW - Thermographie
KW - ZfP
KW - Timber
PY - 2015
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-346377
UR - https://www.ndt.net/?id=18419
SN - 1435-4934
VL - 20
IS - 11
SP - 1
EP - 11
PB - NDT.net
CY - Kirchwald
AN - OPUS4-34637
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Helmerich, Rosemarie
A1 - Mielentz, Frank
A1 - Milmann, Boris
A1 - Adam, Louisa
A1 - Villalobos, S.
A1 - Guimaraes, M.
A1 - Wiggenhauser, Herbert
T1 - Detection of cracks perpendicular to the surface using acoustic methods
N2 - Cracks perpendicular to the surface may be initial indicators for a deterioration process of concrete structures. Moisture penetrates inside the structure and transports adverse chemicals. The paper presents an investigation about the reliability of available commercial non-destructive evaluation techniques to reliably estimate the depth of surface-breaking cracks in reinforced concrete structures. Aim of the study was the investigation of surface-braking cracks under laboratory conditions. Commercial acoustic devices as impact echo equipment, single ultrasonic transducers and arrays were applied even if they have not been developed for this purpose. The commercial software and descriptions for application was followed strictly to compare the function, precision and repeatability of the measurements. Both, perpendicular notches and cracks have been considered. The study was completed with a discussion about reference specimens. The study was the basis for formulation of gaps in research. The Electric Power Research Institute (EPRI) has initiated and funded a Project.
T2 - NDT-CE 2015 - International symposium non-destructive testing in civil engineering
CY - Berlin, Germany
DA - 15.09.2015
KW - Acoustic test
KW - Commercial acoustic devices
KW - Ultrasonic test
KW - Crack depth
KW - Concrete specimens
PY - 2015
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-345729
UR - https://www.ndt.net/?id=18412
SN - 1435-4934
VL - 20
IS - 11
SP - 1
EP - 9
PB - NDT.net
CY - Kirchwald
AN - OPUS4-34572
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Völker, Christoph
A1 - Shokouhi, P.
T1 - Data aggregation for improved honeycomb detection in concrete using machine learning-based algorithms
N2 - We present the results of several machine learning (ML)- inspired data fusion algorithms applied to multi-sensory nondestructive testing (NDT) data. Our dataset consists of Impact-Echo (IE), Ultrasonic Pulse Echo (US) and Ground Penetrating Radar (GPR) data collected on large-scale concrete specimens with built–in simulated honeycombing defects. The main objective is to improve the detectability of honeycombs by fusing the information from the three different sensors. We describe normalization, feature detection and optimal feature selection. We have used unsupervised and supervised ML, i.e., classification and clustering, for data fusion. We demonstrate the advantage of data fusion in reducing the false positives up to 10% compared to the best single sensor, thus, improving the detectability of the defects. The methods were evaluated on a concrete specimen. The effectiveness of the proposed approach was demonstrated on a separate full-scale concrete specimen. The results indicate the transportability of the conclusions from one specimen to the other.
T2 - NDT-CE 2015 - International symposium non-destructive testing in civil engineering
CY - Berlin, Germany
DA - 15.09.2015
KW - Data fusion
KW - Concrete evaluation
KW - Honeycombing
KW - Machine learning
KW - Clustering
PY - 2015
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-350968
UR - https://www.ndt.net/?id=18364
SN - 1435-4934
VL - 20
IS - 11
SP - 1
EP - 8
PB - NDT.net
CY - Kirchwald
AN - OPUS4-35096
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Rothbart, Nick
A1 - Maierhofer, Christiane
A1 - Goldammer, M.
A1 - Hohlstein, F.
A1 - Koch, J.
A1 - Kryukov, I.
A1 - Mahler, G.
A1 - Stotter, B.
A1 - Oswald-Tranta, B.
A1 - Sengebusch, M.
T1 - A round robin test of flash thermography of CFRP and metal structures
N2 - Within the scope of a DIN INS project, a flash thermography round robin test that evaluates reliability, comparability and efficiency of different testing situations is organized. The results give information about the detectability of defects e.g. by their size and depth, the evaluation method and by the materials used. Besides, the influence of equipment and parameters used by the participants on the results were analysed. All of the quantitative results as well as the feedback given by the participants will be presented in a DIN committee in order to contribute to a flash thermography standard.
T2 - 7th International Symposium on NDT in Aerospace
CY - Bremen, Germany
DA - 16.11.2015
KW - Flash thermography
KW - Round robin test
KW - Metal
KW - Flat bottom holes
KW - SNR
PY - 2016
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-351070
UR - https://www.ndt.net/?id=18921
SN - 1435-4934
VL - 21
IS - 4
SP - 1
EP - 8
PB - NDT.net
CY - Kirchwald
AN - OPUS4-35107
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Millar, Steven
A1 - Gottlieb, Cassian
A1 - Wilsch, Gerd
A1 - Eichler, Thorsten
A1 - Bohling, C.
A1 - Molkenthin, A.
T1 - Laser induced breakdown spectroscopy (LIBS) - On-site investigatioons on a bridge with a mobile LIBS-system
N2 - LIBS is on the step from a laboratory application to on-site analysis. A validated mobile LIBS-system for on-site application on building materials is under development at BAM in cooperation with industrial partners (system developers and companies), who will use this technique for investigation on building structures like bridges and parking decks. The system is designed to measure the content of harmful species like chlorine, sulfur or alkalis, to give the engineer a tool for the estimation of the condition of concrete structures and for quality assurance during concrete repair work on-site. In these work results of on-site measurements on a chloride contaminated bridge are shown. Further work will focus on providing guidelines to establish LIBS as a standard procedure for chemical investigations of building materials.
T2 - NDT-CE 2015 - International symposium non-destructive testing in civil engineering
CY - Berlin, Germany
DA - 15.09.2015
KW - LIBS
KW - Chlorides
KW - Sulfur
KW - Alkalis
KW - Corrosion
KW - ASR
KW - Chemical analysis
KW - Chloride
KW - Elementanalyse
KW - Natrium
KW - Baustoffuntersuchungen
KW - Baustoffe
KW - Dauerhaftigkeit
KW - Messsysteme
KW - Mobiles LIBS
PY - 2015
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-345795
UR - http://www.ndt.net/?id=18296
SN - 1435-4934
VL - 20
IS - 11
SP - 1
EP - 5
PB - NDT.net
CY - Kirchwald
AN - OPUS4-34579
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Grothe, Sven
T1 - Ultrasonic signal evaluation used to detect weather-related temperature changes in a concrete specimen
N2 - Ultrasonic measurement evaluation methods have been proven to be effective for detection of subtle changes, caused by temperature, load or moisture. However, for its application outdoors it is necessary to analyse unavoidable influences, such as weather. Therefore an ultrasonic monitoring system with 40 ultrasonic sensors (20 transmitters, 20 receivers; 25 kHz central frequenzy) has been implemented on a concrete specimen (4×5×0.8m3), that is exposed to weather conditions. Data from 400 sensor combinations was collected over a period of six months with an interval of two hours. The data was evaluated by both qualitative (correlation techniques) and quantitative (ultrasonic velocity changes via Coda Wave Interferometry and time of flight method) evaluation methods and compared to the temperature changes caused by weather.
T2 - NDT-CE 2015 - International symposium non-destructive testing in civil engineering
CY - Berlin, Germany
DA - 15.09.2015
PY - 2015
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-346398
UR - https://www.ndt.net/?id=18336
SN - 1435-4934
VL - 20
IS - 11
SP - 1
EP - 4
PB - NDT.net
CY - Kirchwald
AN - OPUS4-34639
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Pasternak, H.
A1 - Launert, B.
A1 - Kannengießer, Thomas
A1 - Rhode, Michael
T1 - Advanced residual stress assessment of plate girders through welding simulation
N2 - This article provides an impression on potentials in applying nowadays welding simulation tools in construction design. This is carried out exemplary on plate girders from two structural steel grades. The calculated residual stresses are compared with measurements by sectioning method. It has been repeatedly stated that present Eurocode models fail to approximate the residual stresses. Especially for high strength steel (HSS) only limited information is available on realistic occurring residual stresses in typical I-girders. The investigations are aimed to give further guidance on these values. A few proposals on advanced models are discussed.
T2 - MBST 2016 - Modern Building Materials, Structures and Techniques
CY - Vilnius, Litunia
DA - 26.05.2016
KW - Residual stresses
KW - Plate girders
KW - I-shape sections
KW - High-strength steel
KW - Welding simulation
PY - 2017
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-392177
UR - http://www.sciencedirect.com/science/article/pii/S1877705817305192
DO - https://doi.org/10.1016/j.proeng.2017.02.013
SN - 1877-7058
IS - 172
SP - 23
EP - 30
PB - Elsevier
CY - Amsterdam, Niederlande
AN - OPUS4-39217
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Galindo Guerreros, Julio Cesar
A1 - Niederleithinger, Ernst
A1 - Mackens, S.
A1 - Fechner, T.
T1 - Quality assurance of jet grout columns with borehole seismic measurements
N2 - Sealing and strengthening of the subsoil by injection is a major issue in the field of geotechnical engineering. One commonly applied method is jet grouting, which allows creating columns of grouted soil by eroding and mixing the in-situ soil with a thin cement suspension. A general difficulty linked with this method is to predict the resulting column diameter and its material strength. In this paper we illustrate the application of a newly developed non-destructive quality assurance testing tool used to determine the diameter of jet grout columns. This approach incorporates standard crosshole and downhole seismic measurements. To demonstrate its effectiveness, we tested the new approach within two-dimensional finite-difference numerical simulations. Additional field tests showed that this tool is also applicable in real site conditions. For this purpose, three jet grout columns were produced with different process parameters in a depth between 3.0 and 10 m. The evaluated diameters were within 1.0 and 1.5 m, slightly deviating from the previously predicted range by the jet grouting contractor. Moreover, we were able to detect the base of the columns at 10 m depth with no significant difficulties. On the other hand, unsaturated, partly unconsolidated sands between ground water level and surface considerably affected the seismic data, hence complicating the detection of the top of the columns.
T2 - NDT-CE 2015 - International symposium non-destructive testing in civil engineering
CY - Berlin, Germany
DA - 15.09.2015
KW - Jet grout
KW - Seismics
KW - Crosshole
KW - Downhole
PY - 2015
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-346753
UR - https://www.ndt.net/?id=18277
SN - 1435-4934
VL - 20
IS - 11
SP - 1
EP - 7
PB - NDT.net
CY - Kirchwald
AN - OPUS4-34675
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Gradt, Thomas
A1 - Schneider, Thomas
T1 - Tribological performance of MoS2 coatings in various environments
N2 - Molybdenum disulfide (MoS₂) is a well-known solid lubricant for tribosystems running in vacuum or dry gases. Problems arise due to its sensitivity to humidity, which is a drawback for its application under ambient conditions. However, by using a physical vapor deposition (PVD) process, deposition parameters can be optimized not only to gain a coatings structure with favorable frictional properties but also to minimize the sensitivity to attack by water molecules. Therefore, an improved tribological behavior even under moist conditions can be achieved. MoS₂coatings are also candidates for being applied at cryogenic temperatures. They already have proven their suitability, e.g., for sliding support elements between superconducting magnets of the nuclear fusion-experiment Wendelstein 7-X. However, these coatings were exclusively produced for this particular application and the utilization for more common tribosystems may be precluded due to cost considerations. In view of a wider range of applications, pure and Cr containing PVD-MoS₂ coatings with an optimized structure were tested under varying environments including hydrogen gas and cryogenic temperatures. Results of the most promising variant are presented in this paper.
KW - Solid lubrication
KW - MoS2
KW - Extreme environments
KW - Hydrogen
KW - Cryogenic einvironment
PY - 2016
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-381460
DO - https://doi.org/10.3390/lubricants4030032
SN - 2075-4442
VL - 32
IS - 4
PB - MPPI AG
CY - Basel, Switzerland
AN - OPUS4-38146
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Kanje, S.
A1 - Hober, S.
A1 - Mueller, L.
A1 - Herrmann, Antje Jutta
T1 - Next generation of labeling reagents for quantitative and multiplexing immunoassays by the use of LA-ICP-MS
N2 - Immuno imaging by the use of Laser Ablation Inductively Coupled Mass Spectrometry (LA-ICP-MS) is a growing research field in life sciences such as biology and biomedicine. Various element labeling strategies for antibodies have been developed for the application of multiplex immunoassays analyzed by the use of LA-ICP-MS. High multiplexing capabilities, a wide linear dynamic range and the possibility of absolute quantification are the main advantages of ICP-MS. But in the context of immuno imaging by the use of LA-ICP-MS, quantification of analytes is limited due to non-controllable antibody labeling chemistry. In the presented proof-of-principle a novel antibody labeling technique has been investigated which results in a controlled labeling degree. A small affinity protein based on the C2 domain of protein G was modified with conventional metal coded tags (MeCAT) after introducing a cysteine into the C-terminus of the protein. The modified C2 domain photo-crosslinks to the Fc or Fab region of the IgG and allows specific and covalent labeling of antibodies for multiplex immunoassay analysis by the use of LA-ICP-MS. In combination with a house-made calibration membrane the amount of labeled antibody–antigen complexes in a multiplex western blot immunoassay was determined by LA-ICP-MS.
KW - LA-ICP-MS based immunoassays
KW - Antibody labeling
PY - 2016
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-384712
DO - https://doi.org/10.1039/c6an01878e
SN - 0003-2654
SN - 1364-5528
VL - 141
IS - 23
SP - 6374
EP - 6380
PB - The Royal Society of Chemistry
AN - OPUS4-38471
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Fischer, Franziska
A1 - Wenzel, Klaus-Jürgen
A1 - Rademann, K.
A1 - Emmerling, Franziska
T1 - Quantitative determination of activation energies in mechanochemical reactions
N2 - Mechanochemical reactions often result in 100% yields of single products, making purifying procedures obsolete. Mechanochemistry is also a sustainable and eco-friendly method. The ever increasing interest in this method is contrasted by a lack in mechanistic understanding of the mechanochemical reactivity and selectivity. Recent in situ investigations provided direct insight into formation pathways. However, the currently available theories do not predict temperature T as an influential factor. Here, we report the first determination of an apparent activation energy for a mechanochemical reaction. In a temperaturedependent in situ study the cocrystallisation of ibuprofen and nicotinamide was investigated as a model system. These experiments provide a pivotal step towards a comprehensive understanding of milling reaction mechanisms.
KW - Mechanochemistry
KW - Cocrystal
KW - Activation energy
KW - Milling
PY - 2016
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-377444
DO - https://doi.org/10.1039/c6cp04280e
SN - 1463-9076
SN - 1463-9084
VL - 18
IS - 33
SP - 23320
EP - 23325
AN - OPUS4-37744
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Schwarz, F.
A1 - Heinrich, Thomas
A1 - Lippitz, Andreas
A1 - Unger, Wolfgang
A1 - Schalley, C.
T1 - A photoswitchable rotaxane operating in monolayers on solid support
N2 - A novel photoswitchable rotaxane was synthesised and its switching behaviour in solution was analysed with NMR and UV-Vis. A monolayer of rotaxanes was deposited on glass surfaces and the on-surface photoswitching was investigated. Angle-resolved NEXAFS spectra revealed a preferential orientation that reversibly changes upon switching.
KW - XPS
KW - NEXAFS
KW - Photoswitchable rotaxane
KW - Self assembly
PY - 2016
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-386814
DO - https://doi.org/10.1039/c6cc08586e
SN - 0022-4936
SN - 1364-548X
SN - 0009-241x
SN - 1359-7345
VL - 52
IS - 100
SP - 14458
EP - 14461
PB - Royal Society of Chemistry (RSC)
AN - OPUS4-38681
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Orts Gil, Guillermo
A1 - Natte, Kishore
A1 - Österle, Werner
T1 - Multi-parametric reference nanomaterials for toxicology: state of the art, future challenges and potential candidates
N2 - A major requirement for the validation of methods assessing the risk associated with engineered nanoparticles (ENPs) is the use of reference materials (RMs). In the present contribution we review available RMs, ongoing projects and characterisation trends in the field. The conclusion is that actual approaches to RMs mostly deal with metrological considerations about single properties of the ENPs, typically their primary size, which can hardly be representative of nanoparticles characteristics in real testing media and therefore, not valid for reliable and comparable toxicological studies. As an alternative, we discussed the convenience and feasibility of establishing multi-parametric RMs for a series of ENPs, focusing on silica nanoparticles (SNPs). As a future perspective, the need to develop RMs based on hybrid nanoparticles is also discussed.
KW - Referenzmaterialien
KW - Nanopartikel
KW - Toxikologie
KW - Metrologie
PY - 2013
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-292997
DO - https://doi.org/10.1039/c3ra42112k
SN - 2046-2069
VL - 3
IS - 40
SP - 18202
EP - 18215
PB - RSC Publishing
CY - London
AN - OPUS4-29299
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Kasper, J.
A1 - Hermanns, M.
A1 - Bantz, C.
A1 - Maskos, Michael
A1 - Stauber, R.
A1 - Pohl, C.
A1 - Unger, R. E.
A1 - Kirkpatrick, J.C.
T1 - Inflammatory and cytotoxic responses of an alveolar-capillary coculture model to silica nanoparticles: comparison with conventional monocultures
N2 - To date silica nanoparticles (SNPs) play an important role in modern technology and nanomedicine. SNPs are present in various materials (tyres, electrical and thermal insulation material, photovoltaic facilities). They are also used in products that are directly exposed to humans such as cosmetics or toothpaste. For that reason it is of great concern to evaluate the possible hazards of these engineered particles for human health. Attention should primarily be focussed on SNP effects on biological barriers. Accidentally released SNP could, for example, encounter the alveolar-capillary barrier by inhalation. In this study we examined the inflammatory and cytotoxic responses of monodisperse amorphous silica nanoparticles (aSNPs) of 30 nm in size on an in vitro coculture model mimicking the alveolar-capillary barrier and compared these to conventional monocultures.
Methods
Thus, the epithelial cell line, H441, and the endothelial cell line, ISO-HAS-1, were used in monoculture and in coculture on opposite sides of a filter membrane. Cytotoxicity was evaluated by the MTS assay, detection of membrane integrity (LDH release), and TER (Transepithelial Electrical Resistance) measurement. Additionally, parameters of inflammation (sICAM-1, IL-6 and IL-8 release) and apoptosis markers were investigated.
Results
Regarding toxic effects (viability, membrane integrity, TER) the coculture model was less sensitive to apical aSNP exposure than the conventional monocultures of the appropriate cells. On the other hand, the in vitro coculture model responded with the release of inflammatory markers in a much more sensitive fashion than the conventional monoculture. At concentrations that were 10-100fold less than the toxic concentrations the apically exposed coculture showed a release of IL-6 and IL-8 to the basolateral side. This may mimic the early inflammatory events that take place in the pulmonary alveoli after aSNP inhalation. Furthermore, a number of apoptosis markers belonging to the intrinsic pathway were upregulated in the coculture following aSNP treatment. Analysis of the individual markers indicated that the cells suffered from DNA damage, hypoxia and ER-stress.
Conclusion
We present evidence that our in vitro coculture model of the alveolar-capillary barrier is clearly advantageous compared to conventional monocultures in evaluating the extent of damage caused by hazardous material encountering the principle biological barrier in the lower respiratory tract.
KW - Silica nanoparticles
KW - Alveolar-capillary coculture model
KW - Cytotoxicity
PY - 2011
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-254217
DO - https://doi.org/10.1186/1743-8977-8-6
SN - 1743-8977
VL - 8
IS - 6
SP - 1
EP - 16(?)
PB - BioMed Central
CY - London
AN - OPUS4-25421
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Hanelt, Sven
A1 - Friedrich, Jörg Florian
A1 - Meyer-Plath, Asmus
T1 - UV spectrometric indirect analysis of brominated MWCNTs with UV active thiols and an alkene-reaction kinetics, quantification and differentiation of adsorbed bromine and oxygen
N2 - Indirect UV-absorption spectrometry was shown to be a valuable tool for chemical characterization of functionalized carbon nanotubes (CNTs). It complements data from X-ray photoelectron spectroscopy (XPS) or FTIR analysis since it helps to clarify the type and concentration of functional groups. The principles of indirect application of UV-spectrometry and its mathematical interpretation are discussed. Their facile application, together with their adequate sensitivity and high flexibility, make UV-absorption-based approaches a valuable alternative to fluorescence spectrometry. Here, the approach was applied to the chemical analysis of oxidizing substances on CNTs. For this, pristine CNTs of low but finite oxygen content as well as brominated CNTs were analyzed by reaction in suspension with UV-active thiol reagents and a styrene derivative. It was shown that carefully selected reagents allow differentiation and quantification of bromine and generally oxidizing entities like oxygen. For brominated CNTs, it was shown that physisorbed bromine may dominate the overall bromine content.
KW - Carbon nanotubes
KW - CNTs
KW - UV-spectrometry
KW - Bromination
KW - Thiols
KW - Mercaptans
KW - Disulfides
KW - Quantification
KW - Kinetics
PY - 2013
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-289077
DO - https://doi.org/10.3390/ma6083035
SN - 1996-1944
VL - 6
IS - 8
SP - 3035
EP - 3063
PB - MDPI
CY - Basel
AN - OPUS4-28907
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Kuhlich, Paul
A1 - Emmerling, Franziska
A1 - Piechotta, Christian
A1 - Nehls, Irene
T1 - Methyl 3,5,5,6,8,8-hexamethyl-5,6,7,8-tetrahydronaphthalene-2-carboxylate (AHTN-COOMe)
N2 - Crystals of the title compound, C18H26O2, were grown from ethyl acetate. Due to the racemic precursor, the title compound is also obtained as a racemate. Disorder was observed during structure refinement, originating from two possible half-chair conformations of the non-aromatic ring. The disorder was refined by introducing split positions in the cyclo-hexane ring regarding the two possible R and S-enantiomers at the chiral CH group [ratio 0.744 (3):0.256 (3)]. The crystal structure features pairs of inversion-related molecules connected by pairs of non-classical C–H···O hydrogen bonds.
KW - AHTN
KW - Tonalide
KW - Cyclic musk
KW - AHTN-COOMe
KW - Disinfection by-product
KW - Esterification
PY - 2011
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-232769
DO - https://doi.org/10.1107/S1600536811002601
SN - 1600-5368
VL - E67
IS - 2
SP - o485, sup-1
EP - sup-11
PB - Munksgaard
CY - Copenhagen
AN - OPUS4-23276
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Stajanca, Pavol
A1 - Krebber, Katerina
T1 - Radiation-induced attenuation of perfluorinated polymer optical fibers for radiation monitoring
N2 - Due to some of their unique properties, optical fiber dosimeters are attractive and extensively researched devices in several radiation-related areas. This work evaluates the Performance and potential of commercial perfluorinated polymer optical fibers (PF-POFs) for radiation Monitoring applications. Gamma radiation-induced attenuation (RIA) of two commercial PF-POFs is evaluated in the VIS spectral region. Influence of a dose rate and temperature on RIA measurement is investigated, along with defect stability and measurement repeatability. Co-extruded PF-POFs are identified as more suitable for radiation monitoring applications due to lower dose-rate dependence.
With co-extruded PF-POF, RIA measurement holds potential for highly-sensitive radiation Monitoring with good reproducibility. The results show that operation in the blue part of the spectrum provides most favorable performance in terms of the largest nominal Radiation sensitivity, lower temperature, and dose-rate dependence as well as higher defect stability. We demonstrate for the first time to our knowledge, that PF-POFs can be used for distributed detection of radiation with doses down to tens of Grays. The off-the-shelf, user-friendly PF-POF could be of interest as a cheap, disposable sensor for various applications, especially of a more qualitative nature.
KW - Perfluorinated polymer optical fiber
KW - Cytop
KW - Ionizing radiation
KW - Radiation-induced attenuation
KW - Gamma radiation monitoring
PY - 2017
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-419504
DO - https://doi.org/10.3390/s17091959
SN - 1424-8220
VL - 17
IS - 9
SP - Article 1959, 1
EP - 12
PB - MDPI
AN - OPUS4-41950
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Pelkner, Matthias
A1 - Neubauer, Andreas
A1 - Reimund, Verena
A1 - Kreutzbruck, Marc
T1 - Routes for GMR-sensor design in non-destructive testing
N2 - GMR sensors are widely used in many industrial segments such as information technology, automotive, automation and production, and safety applications. Each area requires an adaption of the sensor arrangement in terms of size adaption and alignment with respect to the field source involved. This paper deals with an analysis of geometric sensor parameters and the arrangement of GMR sensors providing a design roadmap for non-destructive testing (NDT) applications. For this purpose we use an analytical model simulating the magnetic flux leakage (MFL) distribution of surface breaking defects and investigate the flux leakage signal as a function of various sensor parameters. Our calculations show both the influence of sensor length and height and that when detecting the magnetic flux leakage of µm sized defects a gradiometer base line of 250 µm leads to a signal strength loss of less than 10% in comparison with a magnetometer response. To validate the simulation results we finally performed measurements with a GMR magnetometer sensor on a test plate with artificial µm-range cracks. The differences between simulation and measurement are below 6%. We report on the routes for a GMR gradiometer design as a basis for the fabrication of NDT-adapted sensor arrays. The results are also helpful for the use of GMR in other application when it comes to measure positions, lengths, angles or electrical currents.
KW - Giant magneto resistance
KW - Non-destructive testing
KW - Magnetic flux leakage
KW - Sensor array
PY - 2012
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-271325
DO - https://doi.org/10.3390/s120912169
SN - 1424-8220
VL - 12
IS - 9
SP - 12169
EP - 12183
PB - MDPI
CY - Basel
AN - OPUS4-27132
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Gaebler, A.
A1 - Moessinger, A.
A1 - Goelden, F.
A1 - Manabe, A.
A1 - Goebel, M.
A1 - Follmann, R.
A1 - Koether, D.
A1 - Modes, C.
A1 - Kipka, A.
A1 - Deckelmann, M.
A1 - Rabe, Torsten
A1 - Schulz, Bärbel
A1 - Kuchenbecker, Petra
A1 - Lapanik, A.
A1 - Mueller, S.
A1 - Haase, W.
A1 - Jakoby, R.
T1 - Liquid crystal-reconfigurable antenna concepts for space applications at microwave and millimeter waves
N2 - Novel approaches of tunable devices for millimeter wave applications based on liquid crystal (LC) are presented. In the first part of the paper, a novel concept of a tunable LC phase shifter realized in Low Temperature Cofired Ceramics technology is shown while the second part of the paper deals with a tunable high-gain antenna based on an LC tunable reflectarray. The reflectarray features continuously beam scanning in between ±25°. Also first investigations on radiation hardness of LCs are carried out, indicating that LCs might be suitable for space applications.
KW - Tunable antenna
KW - Phase shifter
KW - Liquid crystal
KW - LTCC
PY - 2009
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-194273
DO - https://doi.org/10.1155/2009/876989
SN - 1687-5877
VL - 2009
IS - Article ID 876989
SP - 1
EP - 7
PB - Hindawi Publishing Corporation
CY - New York, NY, USA
AN - OPUS4-19427
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Risse, Kerstin
A1 - Nikiforidis, Constantinos V.
A1 - Morris, Imogen
A1 - Thünemann, Andreas
A1 - Drusch, Stephan
T1 - Regulating the heat stability of protein-phospholipid stabilised oil-water emulsions by changing the phospholipid headgroup or fatty acyl chain
N2 - Stabilising oil–water emulsions remains a central challenge across food, pharmaceutical and cosmetic applications. β-lactoglobulin (β-LG) and phospholipids (PLs) can act synergistically at oil-water interfaces: PLs adsorb rapidly, while β-LG forms a viscoelastic protein network that enhances long-term stability. However, competitive adsorption between proteins and PLs can disrupt interfacial structure. In addition, for commercial production, emulsions are often exposed to heat treatment during or after manufacture, for instance due to food safety requirements. Yet, the combined effects of PL structure and heat treatment on interfacial organisation and emulsion stability remain poorly understood.
Here we show that PL saturation and processing temperature jointly determine interfacial organisation, protein-PL interactions and emulsion stability. Using β-LG-PL emulsions, we combined ζ-potential measurements, small-angle X-ray scattering (SAXS), micro-differential scanning calorimetry (μDSC), X-ray diffraction and confocal laser scanning microscopy (CLSM) to link interfacial composition with functional stability.
Below the β-LG denaturation temperature (≤75 °C), saturated PLs promoted partial unfolding of β-LG at the interface without displacement, producing mixed protein-PL networks with enhanced viscoelasticity and stability. Unsaturated PLs displaced β-LG, yielding less elastic interfaces and promoting protein aggregation in the bulk. At ≥75 °C, increased hydrophobicity intensified protein-protein interactions irrespective of PL type.
Our findings reveal that saturated PLs shift the β-LG denaturation temperature upward by restricting molecular mobility, without preventing quaternary-level protein-protein interactions. Thermal denaturation, regardless of PL type, promoted interfacial multilayer formation at 90 °C. These results provide a mechanistic framework for tailoring emulsion stability via lipid saturation and processing temperature.
KW - Small-angle X-ray scattering
KW - SAXS
KW - Nanostructure
KW - Reference Method
KW - Colloid
KW - Nanoparticle
PY - 2026
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-648956
DO - https://doi.org/10.1016/j.jcis.2025.139530
SN - 0021-9797
VL - 705
SP - 1
EP - 25
PB - Elsevier Inc.
AN - OPUS4-64895
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Wiehle, Philipp
A1 - Härder, Michelle
A1 - Strangfeld, Christoph
T1 - Quantification of moisture content in earth block masonry under natural climatic conditions
N2 - The aim of this study is to accurately predict the moisture content in earth block masonry exposed to natural climatic conditions, which is a key factor in assessing its load-bearing capacity. Nuclear magnetic resonance relaxometry and humidity sensor measurements were carried out to quantify the moisture content. In addition, a customised test setup was developed to determine the capillary water absorption of earth blocks. This approach takes into account the deceleration of water absorption due to the swelling of clay minerals and organic additives, which leads to realistic transport coefficients in the hygroscopic range. This allows the moisture content of earth block masonry to be predicted accurately. With regard to the moisture behaviour of typical exterior wall constructions in living spaces, it was found that the equilibrium moisture content in earth block masonry is always lower than 65 % relative humidity, which corresponds to the permissible limit of the recently published German design standard for load-bearing earth block masonry.
KW - Earth block masonry
KW - NMR relaxometry
KW - Hygrothermal simulation
KW - Load-bearing capacity
KW - Moisture content
KW - Embedded humidity sensors
PY - 2025
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-623518
DO - https://doi.org/10.1016/j.conbuildmat.2024.139513
VL - 459
SP - 1
EP - 10
PB - Elsevier Ltd.
AN - OPUS4-62351
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -