BAM-Publica - Publikationsserver der Bundesanstalt für Materialforschung und -prüfung
Not a member yet
58839 research outputs found
Sort by
Development, Validation and Application of an Accelerated Weathering Protocol for Assessing Bisphenol A Release from Polycarbonate Materials into the environment
No full textBisphenol A (BPA) is under continuous regulatory scrutiny and listed as substance of very high concern (SVHC). Particular concern is related to its frequent detection in surface waters, despite being readily biodegradable. Several studies have been conducted to investigate sources and pathways of BPA in the environment, concluding that its main use as monomer in polycarbonate (PC) contributes only marginally to environmental BPA releases over its life cycle.
To better understand the actual releases of BPA from PC under environmental conditions, a newly developed methodology (Federal Institute for Materials Research and Testing, BAM) was applied, which comprises a novel accelerated weathering protocol for polycarbonate (PC) materials, combined with an advanced analytical setup allowing for improved detection of BPA at trace level concentrations. The weathering protocol achieves a 13.6-fold acceleration compared to Central European outdoor conditions and simulates environmental stressors (global radiation, rain, temperature variations) in a laboratory weathering chamber, with simultaneous BPA release measurements using an organic isotope dilution calibration LC-MS/MS approach. Validation was performed in parallel outdoor exposure tests, by using haze and yellowness index measurements as reference parameters.
PC sample types representative of major polycarbonate applications were examined: Samples with different levels of UV-protection as used in transparent sheets used outdoor in construction or housings in Electro- and Electronic applications as well as samples with a protective coating as used in automotive applications (headlamps, glazing and construction).
Results demonstrated consistently low total BPA releases of around 0.3 mg m⁻² for samples with exposed PC surfaces, while releases from coated samples were significantly reduced by around two orders of magnitude. In all cases examined, the BPA release ceased to zero after a period of four to six weeks, equivalent to approximately 1 to 1.5 years of outdoor exposure. This suggests that potential BPA releases diminish to virtually zero after that timespan. While the newly developed test method is not suitable for routine laboratory implementation, it provides crucial quantitative data on BPA release from PC materials during accelerated environmental weathering
Ag₂S nanocrystals as next-generation, heavy-metal free SWIR emitter for biomedical imaging and sensing applications
No full textThere is a growing interest in the exploitation of the short-wave infrared (SWIR), which refers to the wavelength band of light between 900 nm and 2500 nm. Luminophores that emit in the SWIR are used in various areas of telecommunications, photovoltaics, security systems (night vision), and in biomedicine. In particular for biomedical applications, the SWIR range is highly promising because light scattering, absorption, and autofluorescence of tissue and biological compounds are strongly reduced compared to the visible (400–700 nm) and NIR (~700–900 nm). The benefits of SWIR-emissive QDs have been demonstrated for a variety of applications, such as in thermal sensing, as photoelectrochemical biosensor, in in vivo vascular imaging, and for fluorescence-guided surgery.
Full exploitation of SWIR photoluminescence (PL) imaging and sensing is currently hampered by i.) a lack of suitable advanced nanomaterials with a high PL quantum yield (PL QY) and a high brightness, that can be used safely in vivo and ii.) a lack of quantitative and reliable data on the optical properties of many SWIR emitters. Promising nanomaterials for the SWIR are heavy metal-free Ag2S quantum dots (QDs).
Aiming for the development of SWIR advanced nanomaterials with optimum performance, we have dived deeper into the photophysical processes occurring in these nanomaterials, thereby exploring in depth how the environment such as temperature, surface ligand composition, and the incorporation of transition metals influence the optical properties Ag2S QDs. We observed a strong enhancement of the SWIR emission of upon addition of metal ions such as Zn2+, yielding PL quantum yields of about 10% and thus making them highly suitable for non-invasive deep imaging of vascular networks and 3D fluid flow mapping
High-Entropy Metal Phosphate Synthesis: Advancements through Automation and Sequential Learning Optimization
No full textTo accelerate high-entropy metal phosphate (HEMP) discovery, we employed a Random Forest regression model within a SLAMD framework. Trained on limited initial data, the model efficiently explored the vast compositional space to predict a novel five-metal phosphate, which was then successfully synthesized and validated experimentally
Better with age? Discussion of creep phenomena during initial loading of type 4 composite pressure vessels
No full textA presentation on the impact of creep phenomena during initial loading on the safety of type 4 composite pressure vessels. A statistical evaluation of slow burst tests shows an increase of the survival rate of initially loaded composite pressure vessels (sustained load and increased pressure) compared to the ones tested in a brand-new state
Usage of BOF slag and next generation EAF slag in the cement industry
No full textIncreasing amounts of new types of EAFS from the DRP-EAF-route and still significant amounts of BOFS from the DRP-SAF-BOF-route will be produced while BFS will vanish. In two BMBF funded research projects, BAM and FEhS examine the application of slags from future steel production in the cement industry. The project “SlagCEM” investigated the recovery of iron from BOFS while producing a mineral product with good cementitious properties. The reduction of BOFS to recover metallic iron along with the generation of a clinker-like material for the cement industry increases the viscosity of the BOFS. This would require a process at unfeasibly high temperatures of >1.700 °C. Therefore, SlagCEM aimed to modify the BOFS to reduce the viscosity to suitable ranges at lower temperatures of ~1.600 °C. A demonstration trial (20 tons) was carried out and the potential for substitution of OPC was determined. DRI-EOS investigates the utilization of increasing amounts of DRI-based EAFS in the cement industry to compensate the reduced production of GBFS. This requires an adjustment of the slag’s chemical composition and a rapid quenching to create an amorphous structure with latent hydraulic characteristics. The project studies the behavior of the modified slag during the metallurgical process and during solidification, any possibly negative impact on the cementitious or environmental properties as well as the potential to recover metals such as Fe, Cr, Mo and V. The final results of the project “SlagCEM”, finished in 2024, as well as the current state and insights of the project “DRI-EOS”, started in July 2022, shall be presented in this talk
Production of reference materials using a quality by design approach
No full textAccurate analysis of microplastics is based on validated methods and the use of standardized protocols. Therefore, reference materials are essential to determine recovery rates and optimise the existing workflows. The reference materials should mimic the reality in terms of particle properties and concentration and are intended for a special use. The Quality-by-Design approach helps to select the users need and defines a target product profile with mandatory and desired particle properties. We will address different reference material top-down production processes with their limits and challenges for production of materials varying in size ranges of micro- and nanoplastics
FireSpread_MedEU
No full textWildfires are becoming more frequent and severe under the influence of climate change, posing increasing risks to ecosystems, human health, and infrastructure. Accurate spatiotemporal data on wildfire propagation is essential for advancing fire behavior modeling, improving management strategies, and mitigating future impacts. However, existing datasets with both high spatial and temporal resolution are rare, costly, and time-consuming to produce. To address this gap, we present FireSpread_MedEU, a dataset comprising 313 consecutive burned area maps from 102 wildfire events across the Mediterranean and Europe between 2017 and 2023. Burned areas were derived from high-resolution Planet optical satellite imagery (~3 m spatial, mostly daily temporal resolution) using a semi-automated workflow, followed by manual refinement to ensure highest accuracy. Each dataset entry is enriched with detailed metadata and a subjective quality assessment. With its high level of spatiotemporal precision, FireSpread_MedEU provides essential data for the development and validation of machine learning models or wildfire simulation models. It opens new research opportunities in wildfire behavior analysis, risk assessment, and predictive modeling
The marginal notes of Tosefta MS Erfurt
No full textManuscript Erfurt 12 of the Tosefta (now Berlin, Staatsbibliothek, Ms. or. fol. 1220) is one of three major textual witnesses of the Tosefta. This manuscript has over 80 marginal notes which have not merited scholarly attention. This article presents a comprehensive analysis of all the marginal notes, including an evaluation of their ink composition, a palaeographic assessment of the scripts, as well as a philological assessment of their contents. Combining these methodologies differentiates between the glosses of the scribe and those added by later hands and identifies their provenance, allowing us to trace the history of the manuscript via the emendations that took place in the scholarly communities in which the manuscript was studied. One of the important outcomes of the research is an early dating of the manuscript to eleventh-century Italy, overturning the scholarly view which dates the manuscript to twelfth-century Rhinelan
Studies of the black writing inks
No full textIn recent years, the interest in the composition of the inks in papyri documents grew exponentially. Different types of inks were found in the period 4th century BCE to 7th century CE. The paper will demonstrate a simple protocol based on comparison of the ink transparency in the near infrared light and X-ray fluorescence spectroscopy.
The importance of including ink composition into new catalogues and possible formats of such data will be also presented and discussed
Inks in Early Medieval Manuscripts from Chelles: a Scientific Study
No full textThe talk will start with the overview of the ink types and the methods of their characterisation. After displaying XRF spectra of different Carolingian inks the talk will discuss Chelles collection and the labels attributed to Chelles. We will concentrate then on the study of the Chelles manuscripts preserved in Cologne, Vatican and Paris. We will show that there is a good degree of coincidence between the inks of the Chelles manuscripts and the labels attributed to Chelles. We observe unusually early use of vitriolic ink north of the Alps