OPUS documents https://opus4.kobv.de/opus4-bam/index/index/ Wed, 19 Aug 2026 06:47:46 +0200 Wed, 19 Aug 2026 06:47:46 +0200 https://opus4.kobv.de/opus4-bam/frontdoor/index/index/docId/66793 Air pollutants like ozone (O3) & nitrogen dioxide (NO2) may contribute to the increasing prevalence of pollen allergies. O3 & NO2 modify the amino acid tyrosine in pollen allergens by nitration, hydroxylation and cross-linking, potentially altering allergen structure & allergenic potential. Nadine Bothen poster https://opus4.kobv.de/opus4-bam/frontdoor/index/index/docId/66793 Wed, 19 Aug 2026 06:47:46 +0200 https://opus4.kobv.de/opus4-bam/frontdoor/index/index/docId/66792 Green hydrogen is poised to be a critical vector in the global energy transition and plays a crucial role in reducing carbon emissions and creating a global clean energy market. However, the economic viability of large-scale green hydrogen production hinges on the optimal design and location. Namibia has an excellent wind and solar energy potential, enabling a feasible, cost-effective green hydrogen production from intermittent renewable energy. This study developed a techno-economic optimization model for cost-effective green hydrogen facilities in Namibia using a single-objective genetic algorithm to determine the optimal wind, solar, and battery storage capacities needed to meet an annual production target of 355,000 tons at Luderitz, Namibia. The model runs on an hourly time-series simulation and uses a discounted cash flow method to minimize the levelized cost of hydrogen for a full year. The results of the optimized system gave a levelized cost of hydrogen of 2.50 USD/kg compared to 7.5 USD/kg obtained from a study on local hydrogen production analysis. This demonstrated the superior performance of the proposed algorithm. A sensitivity analysis was performed on the green hydrogen system, using different numbers of electrolyzers. A range of 150 to 200 units each rated 17.5 MW. Using the proposed algorithm, it was discovered optimal number of Electrolyzers that results in optimal cost of hydrogen is between 196 and 200 units. The findings demonstrated that the levelized cost of hydrogen is not just an average value, as had been demonstrated by various documented publications. Ernesto Samuel; Tom Wanjekeche; Andreas Ndapuka; Josua Junias; Kai Holtappels article https://opus4.kobv.de/opus4-bam/frontdoor/index/index/docId/66792 Wed, 19 Aug 2026 06:45:49 +0200 https://opus4.kobv.de/opus4-bam/frontdoor/index/index/docId/66788 Hydrogen refueling station (HRS) requires continuous safety monitoring, yet conventional management relies largely on periodic inspection and manual oversight, limiting proactive risk mitigation. This study presents a data-driven intelligent analysis platform for real-time monitoring and anomaly detection of HRS safety data, including pressure, temperature, and flow-rate measurements from compressors, storage tanks, and dispensers. The platform integrates data collection adapters, a time-series database, and machine learning-based diagnostic modules (regression, clustering, and classification) into a unified reference software framework. For anomaly detection, an unsupervised LSTM-Variational Autoencoder trained on normal operating data is combined with DBSCAN-based clustering and a Mann–Kendall trend test to jointly identify point anomalies and pattern-level drifts, addressing the scarcity of labeled abnormal data in HRS environments. A continual learning mechanism further adapts detection thresholds to gradual and abrupt pattern changes without full retraining. The system was deployed and validated at BAM’s demonstration hydrogen refueling station in Germany, integrated with a remote safety-monitoring system and confirmed through performance testing, demonstrating reliable, proactive hydrogen safety management. Minsu Kim; Seongseop Kim; Seungwoo Lee; Youngmin Kwon; Kai Oehring; Robert Bock article https://opus4.kobv.de/opus4-bam/frontdoor/index/index/docId/66788 Wed, 19 Aug 2026 06:07:40 +0200 https://opus4.kobv.de/opus4-bam/frontdoor/index/index/docId/66787 Fatigue failure under high local stresses and strains, as encountered in exceptional load cases or pressure vessel applications, remains a key design challenge. In welded joints, microstructural and geometric imperfections at the weld toes result in pre-existing short cracks and their subsequent propagation. Fatigue life assessment based on linear elastic fracture mechanics has shown high accuracy when crack growth is considered from a technical initial crack size. However, its applicability is limited when the small-scale yielding condition is violated, which is inherent to short cracks and may also occur under high loading conditions typical of the low-cycle fatigue regime. Within the German research project IBESS, a fracture mechanics-based framework for the fatigue assessment of welded joints was developed. The approach includes short crack propagation, statistical variability of weld geometry, and elastic-plastic crack growth. Welded butt joints made of high-strength structural steel and austenitic steel were tested under constant-amplitude loading, resulting in pronounced plastic strain. The results show that plasticity-related corrections significantly improve fatigue life predictions and confirm the applicability of the IBESS approach in the low-cycle fatigue regime. M. Kling lecture https://opus4.kobv.de/opus4-bam/frontdoor/index/index/docId/66787 Mon, 17 Aug 2026 06:35:35 +0200 https://opus4.kobv.de/opus4-bam/frontdoor/index/index/docId/66779 In recent decades, many organic micropollutants, often referred to as emerging contam-inants, have been found in waters from the whole water cycle, including wastewater, surface water, groundwater, and drinking water. Trace analytical methods are needed for monitoring their distribution and concentration trends. Moreover, to cover the whole water cycle and allow for frequent sampling, methods should be fast, cost-effective, ma-trix-tolerant, and portable, at best, true sensors. Immunoanalytical methods, employing antibodies for the sensing step, can provide the necessary selectivity and sensitivity. Since they employ one antibody per compound, most formats are single analyte meth-ods or, at best, allow for oligoplexing. Therefore, to harness their advantages, indicators of contamination should be chosen where no legally binding lists exist. These markers should be able to talk about input of micropollutants into the water cycle, their (partial) elimination in wastewater treatment steps, the input of residues into receiving waters and their potential appearance in groundwater and tap water. The talk will present as base application the ELISA (enzyme-linked immunosorbent as-say) based on microtiter plates as the method of choice for analysing a large number of samples [1]. ELISAs are available for monitoring anthropogenic markers such as the antiepileptic drug carbamazepine, the analgesic diclofenac, the antihistamine cetirizine, the steroid hormone estrone, the antimicrobial sulfamethoxazole, the psychoactive sub-stances caffeine and cocaine, the priority pollutant bisphenol A, and isolithocholic acid, a bile acid. Simpler formats, such as mix-and-read assays, e.g., the fluorescence polari-zation immunoassay (FPIA) [2] or the lateral flow immunoassay (LFIA) [3], are more suitable for on-site screening and monitoring. The latter is based on dipsticks or small cassettes, with which users have become familiar during the COVID-19 pandemic through rapid antigen tests. The suitability of multi-analyte formats such as immunomi-croarrays depends on the choice of a signal generation system that offers small uncer-tainties and good reproducibility. Bead-based (“suspension”) arrays read out in flow cy-tometers are a powerful platform for multiplexed assays [4]. Electrochemical formats running on portable microfluidic devices offer additional advantages as no light source is required. They are particularly promising for stand-alone analysers and biosensors [5]. Speed, low cost and on-site capabilities of immunochemical sensing permits much more data to be collected on markers, enabling for the quantification of inputs and out-puts, thus allowing for a differentiated picture of the contamination of the water cycle to be drawn up. Rudolf Schneider lecture https://opus4.kobv.de/opus4-bam/frontdoor/index/index/docId/66779 Mon, 17 Aug 2026 06:32:09 +0200 https://opus4.kobv.de/opus4-bam/frontdoor/index/index/docId/66786 Transitioning towards hydrogen (H2) as a future energy carrier places renewed demands on structural alloys that were originally qualified for conventional fuel production, storage, and distribution. Hydrogen embrittlement (HE) is still a critical concern for structural material in hydrogen energy systems. Austenitic stainless steel 316L is widely used in high pressure systems and environments requiring corrosion resistance and robust mechanical performance. Nevertheless, its suitability for hydrogen containing piping and vessels cannot be assumed, because hydrogen can modify deformation and damage evolution, particularly under loading states that promote crack initiation and growth. A central experimental challenge is that conventional testing in gaseous hydrogen typically requires enclosing specimens in pressure vessels or autoclaves, which is complex, costly, and limited in accessibility. However, the hollow specimen technique offers a technically compelling alternative: the specimen is internally pressurized with hydrogen, enabling in situ hydrogen exposure at the internal wall while remaining compatible with standard mechanical test frames. This geometry reduces hydrogen volume during tests and avoids impurities associated with electrochemical charging, while better representing service-relevant pressurized components. Recent work demonstrates that hollow specimens can show measurable loss of ductility under hydrogen exposure by reducing elongation in slow strain rate testing (SSRT). However, fatigue datasets for hollow 316L tested directly with internal hydrogen pressure remain scarce. At the same time, most studies using electrochemical and gaseous pre-charging methods suggest that near 10^6 cycles, the fatigue limit of 316L in hydrogen is typically reduced by 10 – 15% compared with air. Against this background, the present study investigates how hollow specimens influence mechanical response and stress life behavior of 316L, and then quantifies hydrogen assisted fatigue under in situ pressurization. A finite element (FE) model is developed to resolve the stress distribution under uniaxial loading, enabling stress and geometry effects to be assessed. The static structural response is validated using comparative tensile experiments on conventional and hollow geometries. Building on this validated mechanical baseline, force controlled high cycle fatigue (HCF) tests will generate Wöhler (S–N) curves for hollow 316L under argon and hydrogen internal pressure environments, at room temperatures. Linus Angula lecture https://opus4.kobv.de/opus4-bam/frontdoor/index/index/docId/66786 Mon, 17 Aug 2026 06:30:46 +0200 https://opus4.kobv.de/opus4-bam/frontdoor/index/index/docId/66785 High local stresses significantly reduce fatigue strength, particularly in welded joints. For the computational fatigue life assessment of such components, fracture mechanics is generally regarded as a suitable and physically well-founded approach. In practical applications, however, the use of fracture mechanics is often limited to concepts of linear elastic fracture mechanics, whose underlying assumptions are only partially fulfilled under loading conditions with pronounced plastic strain components, as typically encountered in the low-cycle fatigue regime. Against this background, a fracture-mechanics-based framework for the fatigue assessment of welded joints was developed within the German research project IBESS. The IBESS approach describes a comprehensive assessment procedure based on short crack propagation and the consideration of crack closure effects, while explicitly accounting for elastic-plastic crack growth mechanisms. Under loading conditions with high local stresses and strains, the consideration of cyclic plasticity becomes of particular importance. In this contribution, the applicability of the IBESS approach to welded butt joints made of high-strength steel under high load amplitudes is investigated. For this purpose, constant-amplitude fatigue tests were conducted, in which pronounced plastic strain components occur. Based on the experimental results, a complete fracture-mechanical assessment using the IBESS approach was performed to estimate fatigue life spanning from low to high-cycle fatigue. The results show that considering multiple crack growth and, in particular, applying plasticity-related correction leads to a significant improvement in the accuracy of fatigue life predictions under these loading conditions compared to linear elastic fracture mechanics. Thus, the fundamental applicability of the IBESS approach is confirmed also for loading conditions with pronounced plastic strain components in the low-cycle fatigue regime. M. Kling; A. Zänsch; K. Rother; Mauro Madia; Uwe Zerbst conferenceobject https://opus4.kobv.de/opus4-bam/frontdoor/index/index/docId/66785 Mon, 17 Aug 2026 06:29:45 +0200 https://opus4.kobv.de/opus4-bam/frontdoor/index/index/docId/66777 The talk presents BAM, the Department of Analytical Chemistry; Reference Materials and the Division of Environmental Analysis and asks how the immunoanalytical assays and sensors that are developed here could be helpful in studies in environmental chemistry as they are carried out at large in the RENEW (Research and Education in eNergy, Environment and Water) Institute at the University at Buffalo (NY, USA). It explores possible lines of cooperation, student exchange and ideas for proposals for joint research. Rudolf Schneider lecture https://opus4.kobv.de/opus4-bam/frontdoor/index/index/docId/66777 Mon, 17 Aug 2026 06:28:11 +0200 https://opus4.kobv.de/opus4-bam/frontdoor/index/index/docId/66784 High local stresses significantly reduce fatigue strength, particularly in welded joints. For the computational fatigue life assessment of such components, fracture mechanics is generally regarded as a suitable and physically well-founded approach. In practical applications, however, the use of fracture mechanics is often limited to concepts of linear elastic fracture mechanics, whose underlying assumptions are only partially fulfilled under loading conditions with pronounced plastic strain components, as typically encountered in the low-cycle fatigue regime. Against this background, a fracture-mechanics-based framework for the fatigue assessment of welded joints was developed within the German research project IBESS. The IBESS approach describes a comprehensive assessment procedure based on short crack propagation and the consideration of crack closure effects, while explicitly accounting for elastic-plastic crack growth mechanisms. Under loading conditions with high local stresses and strains, the consideration of cyclic plasticity becomes of particular importance. In this contribution, the applicability of the IBESS approach to welded butt joints made of high-strength steel under high load amplitudes is investigated. For this purpose, constant-amplitude fatigue tests were conducted, in which pronounced plastic strain components occur. Based on the experimental results, a complete fracture-mechanical assessment using the IBESS approach was performed to estimate fatigue life spanning from low to high-cycle fatigue. The results show that considering multiple crack growth and, in particular, applying plasticity-related correction leads to a significant improvement in the accuracy of fatigue life predictions under these loading conditions compared to linear elastic fracture mechanics. Thus, the fundamental applicability of the IBESS approach is confirmed also for loading conditions with pronounced plastic strain components in the low-cycle fatigue regime. M. Kling lecture https://opus4.kobv.de/opus4-bam/frontdoor/index/index/docId/66784 Mon, 17 Aug 2026 06:26:52 +0200 https://opus4.kobv.de/opus4-bam/frontdoor/index/index/docId/66776 A vast number of emerging pollutants is being detected in the environment. Another lingering prob-lem are health-threatening contaminants, such as mycotoxins, that deteriorate food and feed. Ad-dressing these challenges requires analytical methods that are not only sensitive and reliable at trace levels, but also rapid, cost-effective, and ideally portable. Immunoanalytical (antibody-based) methods provide versatile solutions in this context. Available in diverse formats, they enable both high-throughput screening—using indicator substances or sum parameters—and on-site analysis at the point of need. In addition, multiplexed array technologies allow for the simultaneous detection of multiple analytes. This presentation highlights selected applications targeting anthropogenic contamination markers such as pharmaceuticals, hormones, stimulants, and industrial chemicals, alongside mycotoxins. The results demonstrate the strong potential of antibody-based approaches to deliver actionable analyti-cal insights directly in the field. Rudolf Schneider lecture https://opus4.kobv.de/opus4-bam/frontdoor/index/index/docId/66776 Mon, 17 Aug 2026 06:22:35 +0200 https://opus4.kobv.de/opus4-bam/frontdoor/index/index/docId/66783 The Kitagawa-Takahashi Diagram is an important tool for describing the fatigue limit of components containing defects. The limit line in this diagram can be described using various models, but these differ significantly in the technically important region. For this reason, the KT diagram must be verified in this area through experiments. However, the stair-case method requires a large number of samples and has a long test duration. In addition, many samples with identical notches must be produced. In this work, a method is presented that allows a simpler and faster validation of the Kitagawa-Takahashi Diagram in the region of short cracks. Notches with a defined width and depth were manufactured in flat samples of a low-alloyed steel with two different heat treatments using an engraving laser. This method allows to produce very sharp notches without plastic deformation and with only a slight thermal influence on the surrounding material. The samples prepared in this way were fatigued with blockwise increasing loads until failure. Crack initiation and propagation is monitored with a direct current potential drop method. The number of cycles in each loading block is determined by the measured potential drop. When in a defined interval no potential increase and therefore no crack propagation is detected, the program switches automatically in the next loading block. For each sample, it is therefore possible to determine a stress at which a crack is arrested and a stress that causes the specimen to fail. This procedure enables a reliable and precise determination of the limit stress for the respective notch size with a low experimental effort and time consumption. The method is evaluated on a low alloyed steel in the hardened and normalized condition. In order to investigate the influence of the method used to manufacture the notch, notches of the same width and depth were introduced in the samples using both an engraving laser and Electrical Discharge Machining (EDM). The experiments showed no significant difference between the EDM and laser notches, although the laser notches were significantly sharper. The differences compared to values determined using the staircase method were slightly conservative, but still negligible. This demonstrates the suitability of the method presented here, which, due to the use of laser notches, the significantly shorter test time and the use of less specimens compared to the staircase method, results in a significant reduction in test time and thus also an enormous cost reduction. J. Bär lecture https://opus4.kobv.de/opus4-bam/frontdoor/index/index/docId/66783 Mon, 17 Aug 2026 06:20:44 +0200 https://opus4.kobv.de/opus4-bam/frontdoor/index/index/docId/66775 Micropollutants, including various emerging contaminants, are continuously released into the environment. Detecting their presence using conventional analytical methods is often expensive and time-consuming, making large-scale monitoring impractical. To effectively protect ecosystems and human health, rapid and cost-efficient screening methods are essential. Furthermore, the need to monitor the entire water cycle for micropollutants is becoming increasingly critical, particularly from a One Health perspective, as climate change and growing demands for water reuse amplify environmental challenges. – Antibody-based methods, commonly referred to as immunoassays, offer a promising solution. These rapid and cost-effective techniques can fill information gaps and provide sensors and process analytical technology with short response times. A wide range of immunoanalytical formats is available, from laboratory-based methods to portable analyzers and online sensors. Ensuring the availability of high-quality antibodies is essential to the reliability of these approaches. This talk presents how a whole range of immunoanalytical methods can be employed to trace emerging contaminants in the environment. An indicator for specific industrial inputs is bisphenol A which is also an endocrine disruptor. Additionally, pharmaceuticals serve as important markers of human impact on the water cycle. Natural tracers, such as endogenous hormones and bile acids, help track wastewater pathways, while anthropogenic markers - most notably caffeine - serve as indicators of human activity, frequently appearing in environmental water samples. Rudolf Schneider lecture https://opus4.kobv.de/opus4-bam/frontdoor/index/index/docId/66775 Mon, 17 Aug 2026 06:17:24 +0200 https://opus4.kobv.de/opus4-bam/frontdoor/index/index/docId/66773 Quartz nanopipettes are an important emerging class of electric single-molecule sensors for DNA, proteins, their complexes, as well as other biomolecular targets. However, in comparison to other resistive pulse sensors, nanopipettes constitute a highly asymmetric environment and the transport of ions and biopolymers can become strongly directiondependent. For double-stranded DNA, this can include the characteristic translocation time and tertiary structure, but as we show here, nanoconfinement can also unlock capabilities for biophysical and bioanalytical studies at the single-molecule level. To this end, we show how the accumulation of DNA inside the nanochannel leads to crowding effects, and in some cases reversible blocking of DNA entry, and provide a detailed analysis based on a range of different DNA samples and experimental conditions. Moreover, using biotin-functionalized DNA and streptavidinmodified gold nanoparticles as target, we demonstrate in a proof-of-concept study how the crowding effect, and the resulting increased residence time in nanochannel, can be exploited by first injecting the DNA into the nanochannel, followed by incubation with the nanoparticle target and analysis of the complex by reverse translocation. We thereby integrate elements of sample processing and detection into the nanopipette, as an important conceptual advance, and make a case for the wider applicability of this device concept. Lauren Matthews; Mario Sahre; René Hesse; Robert Schusterbauer; Melissa Grant; Leonardo Agudo Jácome; Tim Albrecht; Vasile-Dan Hodoroaba article https://opus4.kobv.de/opus4-bam/frontdoor/index/index/docId/66773 Mon, 17 Aug 2026 06:16:26 +0200 https://opus4.kobv.de/opus4-bam/frontdoor/index/index/docId/66782 The milling process significantly influences the surface integrity of metallic components through machining induced near-surface residual stresses. Modern hybrid machining processes, such as ultrasonic-assisted milling (USAM), offer the potential to induce beneficial near-surface compressive residual stresses compared to the near-surface tensile residual stresses typically resulting from conventional milling (CM). This study investigates the effects of USAM compared to CM on the near-surface residual stress state and fatigue performance of a S355J2C low-alloy steel. Milling experiments and subsequent rotating bending tests revealed that USAM significantly reduces cutting force by approximately 45% and induces near-surface compressive residual stresses as low as -733 MPa. This leads to a significant improvement in fatigue strength estimated in approximately 34% compared to polished specimens and 11% compared to the CM. These findings highlight the potential of USAM to enhance the fatigue performance of components made of steel. Mauro Madia lecture https://opus4.kobv.de/opus4-bam/frontdoor/index/index/docId/66782 Mon, 17 Aug 2026 06:13:13 +0200 https://opus4.kobv.de/opus4-bam/frontdoor/index/index/docId/66778 In der Analytischen Chemie werden die "grünen" Verfahren, d.h. analytische Methoden, die einen geringen energetischen und umweltbeeinflussenden Fußabdruck haben immer wichtiger, man spricht von "Green Analytical Chemistry", ein Konzept, das in vielen Grundsatzpapieren bereits niedergeschrieben ist. Antikörperbasierte Verfahren, die systemimmanent ohne Lösungsmittel, ohne Gase und Hochdruckpumpen auskommen, können hier wertvolle Beiträge liefern. Der eingeladene Vortrag geht auf Anwendungsmöglichkeiten in der Wasseranalytik, mit der Bewertung nach "Green-ness" verschiedener Formate ein und beurteilt sie für Anwender. Rudolf Schneider lecture https://opus4.kobv.de/opus4-bam/frontdoor/index/index/docId/66778 Mon, 17 Aug 2026 06:11:53 +0200 https://opus4.kobv.de/opus4-bam/frontdoor/index/index/docId/66772 Powder properties are considered a key factor in mechanical properties in laser additive manufacturing, although few studies have investigated the effects in laser beam directed energy deposition for metal materials (DED-LB/ M). Water atomized (WA), and gas atomized (GA) powders are frequently used but may result in different part properties due to powder properties. To examine their qualificationfor DED-LB/M, this work examines powders and mechanical properties of AISI 316 L. Also, examination techniques are compared. The results show that the powder production has no relevant influenceon porosity and Archimedian density of built parts. WA powders show good processability in the process, despite unfavorable morphology. In contrast, WA specimen reach only 10% fracture elongation in tensile testing whereas GA-based specimen achieve 30%. Tensile strength of both is above 500 MPa. The reason for the lower mechanical property values can be attributed to defects and oxides. Yet WA powders may provide a cost-effective alternative for DED-LB/M when a reduced fracture elongation is acceptable. Josefine Lemke; Max Biegler; Michael Rethmeier article https://opus4.kobv.de/opus4-bam/frontdoor/index/index/docId/66772 Mon, 17 Aug 2026 06:07:55 +0200 https://opus4.kobv.de/opus4-bam/frontdoor/index/index/docId/66781 The Kitagawa-Takahashi (KT) diagram is a widespread tool for describing the fatigue limit of components containing defects. It is usually determined experimentally by carrying out fatigue test on smooth specimens and specimens with artificial surface micro-notches of different sizes. Despite its simplicity, this procedure is, however, associated with great experimental effort due to the large number of specimens required and duration of a single test. Therefore, simple empirical relationships have been proposed in the past to approximate the KT diagram based on few basic mechanical properties. Among those, the El Haddad model has long proven to describe fatigue data with satisfactory approximation, even though it suffers from major drawbacks, especially in the technically relevant region of physically-mechanically short cracks. Alternatively, short crack models have the potential to describe the main mechanisms behind the fatigue strength given by the propagation and arrest of short cracks at defects. Based on an extensive experimental campaign carried out on two different structural steels, this work aims to compare the benefits and drawbacks of existing models for the determination of the KT diagram. This includes simple phenomenological relationships, as well as existing short crack models and a more complex methodology based on the so-called cyclic R-curve analysis. The analyses reveal contradictory results, whereby the El Haddad model is mostly non-conservative and short crack models can be overly conservative. The difference between fatigue data and model predictions is discussed based on experimental evidence and additional numerical simulations. Mauro Madia lecture https://opus4.kobv.de/opus4-bam/frontdoor/index/index/docId/66781 Mon, 17 Aug 2026 06:07:11 +0200 https://opus4.kobv.de/opus4-bam/frontdoor/index/index/docId/66780 Today’s omnipresence of microplastic particles poses an imminent threat to the environment and health. Consequently, many analytical techniques have been suggested for their detection and identification regarding size and chemical composition. Among these, Raman microspectroscopy combines chemical identification of polymers with micrometer spatial resolution, but its conventional visible-light excitation requires long integration times, impractical for mapping experiments with sufficient throughput. Extensive and high-resolution mapping can thus extend measurement times to several days. We present a highly accelerated UV-Raman microscope based on the 355 nm output of a DPSS laser for excitation. UV light exhibits enhanced Raman scattering making shorter integration times viable. Additionally, UV light allows for tighter focusing and therefore good spatial resolution can be realized even with cost-effective optics, allowing for a potentially rapid and low-cost setup. The presented microscope was able to extensively map 256 mm2 of dispersed microplastic particles with diameters between 100 and 160 μm in eight hours. An integration time of only 100 ms led to the collection of more than 140,000 spectra in this period allowing for the identification and mapping of microplastics. For the unambiguous identification of polymers with sufficient discrimination within the resulting large dataset unsupervised classification algorithms were successfully employed. As a result, combining fast UV-Raman and unsupervised classification schemes, mapping and classification can be achieved within a single working day. Felix Schröter poster https://opus4.kobv.de/opus4-bam/frontdoor/index/index/docId/66780 Mon, 17 Aug 2026 06:05:58 +0200 https://opus4.kobv.de/opus4-bam/frontdoor/index/index/docId/66774 The revised EU Urban Wastewater Treatment Directive (UWWTD) mandates monitoring the elimination of micropollutants in municipal wastewater treatment plants (WWTPs), creating a strong need for rapid, cost-effective, and matrix-tolerant on-site analytical methods. Conventional monitoring relies on laboratory-based chromatographic and mass spectrometric techniques (e.g., LC-MS), which are accurate but unsuitable for continuous or decentralized applications. Immunoanalytical methods, particularly antibody-based assays, offer high selectivity and sensitivity and can be adapted for field use as rapid tests or integrated biosensors. However, these approaches face inherent limitations: each target analyte requires a specific antibody, restricting multiplexing capabilities and necessitating consensus-driven selection of indicator substances. The new Directive addresses this challenge by introducing a list of micropollutants encompassing several classes. Most of them are pharmaceuticals (e.g., carbamazepine, diclofenac) including antimicrobial compounds (e.g., clarithromycin), others are industrial chemicals (benzotriazoles). They serve as indicators by which WWTPs must demonstrate an average removal efficiency of at least 80% for a defined subset (min. 6) out of this list of 12. This goal is usually reached by applying Advanced Oxidation Processes (AOP) or adsorption on activated carbon. The new regulatory framework provides a clear basis for developing immunoassays tailored to environmental monitoring. Several antibody-based formats are available. The enzyme-linked immunosorbent assay (ELISA) remains the gold standard for high-throughput laboratory analysis and has been successfully applied to wastewater samples for compounds such as carbamazepine, diclofenac, and bisphenol A. For portable applications, mix-and-read assays like the fluorescence polarization immunoassay (FPIA) offer simplified handling, though with reduced sensitivity and matrix tolerance. Lateral flow immunoassays (LFIA), widely known from COVID-19 antigen testing, enable user-friendly, qualitative or semi-quantitative on-site screening. Quantification can be achieved via handheld readers or smartphone-based densitometry. Multiplexing strategies include spatial separation on biochips or spectral separation via a set of fluorescent labels or color-coded beads in LFIA or Suspension Array Fluorescence Immunoassay (SAFIA). Emerging microfluidic and electrochemical immunosensors promise continuous monitoring with minimal infrastructure, leveraging magnetic bead manipulation and amperometric or voltammetric detection for enhanced robustness. Despite these advances, critical challenges remain. Comprehensive validation under real wastewater treatment plant conditions and standardization of performance criteria are essential. Currently, no harmonized norms exist for antibody quality, immunoassay validation, or data interpretation. Efforts to establish such standards are underway within projects and DIN/ISO committees, aiming to ensure regulatory acceptance and comparability of results. Looking forward, climate change and water scarcity underscore the importance of sustainable water management and reuse within a circular economy. On-site immunoanalytics can play a pivotal role by enabling adaptive operation of advanced treatment processes, reducing costs, and minimizing environmental footprints. Achieving this vision demands coordinated research on antibody engineering, sensor integration, and normative frameworks, supported by collaboration among scientific institutions, industry, and regulatory bodies. Rudolf Schneider lecture https://opus4.kobv.de/opus4-bam/frontdoor/index/index/docId/66774 Mon, 17 Aug 2026 06:04:55 +0200 https://opus4.kobv.de/opus4-bam/frontdoor/index/index/docId/66770 Geometric morphology-based two-dimensional (2D) image descriptors are key parameters for transitioning from qualitative to quantitative description, particularly for scanning electron microscopy characterization images of 2D materials such as graphene oxide (GO). Both the size and shape can have a significant impact on the performance of the final product, affecting many different applications of these materials. We established a benchmark test set consisting of 7 groups of standard sample image sets with known, well-defined morphological features. We constructed a comprehensive descriptor set based on geometric morphology, comprising 12 descriptors widely recognized from ISO standards and 4 descriptors we proposed. After quantitative evaluation, three descriptors, Cl (Compactness relative to Axis Length), LR (Ratio of Minor to Major Axis lengths), and equivalent circle diameter, were selected due to their minimal sensitivity to external conditions such as scaling and rotation. These descriptors were further applied to describe four sets of artificially designed standard shapes and commercially purchased GO flakes after their imaging in a microscope. The results demonstrated that the three descriptors effectively captured the elongation, convexity/concavity, and aspect ratio of the flakes, while also providing size information. These descriptors not only accurately describe the shape and size of the flakes, but also meet the practical requirements of being efficient for real-world applications. Lingling Ren; Senlin Jin; Hui Zhang; Andrew J Pollard; Charles A Clifford; Xu Li; Yaxuan Yao; Vasile-Dan Hodoroaba article https://opus4.kobv.de/opus4-bam/frontdoor/index/index/docId/66770 Mon, 17 Aug 2026 06:03:19 +0200 https://opus4.kobv.de/opus4-bam/frontdoor/index/index/docId/66769 We report time-resolved diffuse extreme ultraviolet (EUV) scattering measurements of optically excited acoustic waves in thin Ti/SiN bilayers in transmission geometry. Following femtosecond optical excitation, the EUV diffuse scattering signal yields circular fringe patterns evolving as a function of the time delay between the optical pump and EUV probe pulses. We demonstrate that these patterns originate from multiple guided acoustic modes (Lamb waves) with wavelengths in the range 60–400 nm. By comparing the experimental frequency–wavevector maps with calculated dispersion curves, we show that diffuse scattering signal from Lamb waves is enhanced at discrete frequencies corresponding to longitudinal thickness resonances of the membrane. This observation indicates that Lamb waves with high in-plane wavevectors originate from the scattering of longitudinal thickness resonances by surface roughness. Our findings establish time-resolved diffuse EUV scattering as an efficient tool for probing nanoscale Lamb waves, applicable to the characterization of elastic properties of thin membranes. A. Milloch; N. Agarwal; Jörn Bonse; N. Jaouen; E. Pedersoli; L. Sbuelz; K. Sokolowski-Tinten; R. Totani; S. Urazhdin; A. Valerio; A.A. Maznev; F. Bercivenga; F. Capotondi article https://opus4.kobv.de/opus4-bam/frontdoor/index/index/docId/66769 Thu, 13 Aug 2026 12:25:10 +0200 https://opus4.kobv.de/opus4-bam/frontdoor/index/index/docId/66767 Fibre optic thermometry has revolutionized thermal sensing in environments where traditional electronic sensors – such as thermocouples or Resistance Temperature Detectors (RTDs) – fail due to electromagnetic interference (EMI), high voltages or corrosive atmospheres, for example. They were amongst the first fibre optic sensors to be developed, using a range of different (and often simplistic techniques), usually operating over limited temperature ranges. Xin Lu; Marcus Schukar; T. Sun; G. Failleau; S. Krenek; K. Grattan conferenceobject https://opus4.kobv.de/opus4-bam/frontdoor/index/index/docId/66767 Thu, 13 Aug 2026 12:02:05 +0200 https://opus4.kobv.de/opus4-bam/frontdoor/index/index/docId/66764 Blast and the resultant overpressure (Blast Overpressure – BOP) exposure can cause negative effects to Force Health and Readiness. Such exposures can pose a significant occupational risk among military members both from enemy action and during training from the operation of artillery, shoulder-launched munitions, mortars, high-calibre weapons, and explosives. Most blast exposures over a career are usually experienced in training. Repeated exposure to Low-Level Blast (LLB) can be detrimental to brain health. The cumulative effects of LLB exposure on brain health is of concern. This is distinct from the acute brain effects observed with exposure to a single, high-level blast. Monitoring and documenting Blast Overpressure (BOP) exposure is critical to better understanding the effect on brain health, and to best protect troops throughout and beyond their military careers. Concerned NATO allies formed a multidisciplinary team of military and civilian specialists within the biomechanical and biomedical fields, as well as from the fields of military occupational exposure and implementation domains to develop ‘Guidelines to Mitigate Military Occupational Brain Health Risks from Repetitive Blast Exposure’ as part of NATO STO-TR-HFM-338 Human Factors and Medicine (HFM). The objective of this team was to identify the best practices as well as produce knowledge to control, minimise, and mitigate the risk of developing brain-related health problems due to blast exposure. The HFM-338 aims to achieve this through the development of three products: 1) Blast Interim Exposure Guidelines that may be used today to mitigate the risk of adverse brain health effects; 2) Operational Guidelines that detail the development of four capabilities including: 1) blast exposure monitoring; 2) capture of health; 3) performance information; and 4) data; analysis of blast exposure, health and performance effects, mitigations and health management strategies; 3) Research and Development Guidelines that identify critical research focus areas which, once addressed, will help us better monitor and understand warfighter brain health. Peter Beliveau; Mattias Sköld; Tim Westerhof; Stephen Ahlers; Steffen Grobert; Audun Bjerke; Tyson Josey; Flavie Bompaire; Daniel Krentel; David Borkholder; Katherine Lee; Walter Carr; Simon Ouellet; Scott Featherman; Thanyani Pandelani; Nico Flierman; Matthew Panzer; Johann-David Reinecke; Marianne Ykema-Veerman; Shawn Rind; Narayan Yoganandan; James Stone; Jasper Heeren; Mathieu Philippens; James Mitchell; Olivia Webster; Mangalani Miyambo handbook https://opus4.kobv.de/opus4-bam/frontdoor/index/index/docId/66764 Thu, 13 Aug 2026 06:09:00 +0200 https://opus4.kobv.de/opus4-bam/frontdoor/index/index/docId/66763 Structural Health Monitoring (SHM) using ultrasonic-guided waves (UGWs) enables continuous monitoring of components with complex geometries and provides detailed information about their structural integrity and overall condition. Due to their intricate characteristics, UGWs are highly sensitive to material properties as well as environmental and operational factors such as temperature and pre-stress. To Advance the development and validation of UGW-based SHM evaluation techniques, benchmark datasets are therefore essential for enabling transparent comparison of emerging algorithms. With the growing relevance of composite overwrapped pressure vessels (COPVs) in various industries, this work introduces a comprehensive open-access dataset of UGW measurements on a COPV, to be published on the Open Guided Waves platform. The COPV was placed in a high-pressure hydraulic system, and it was exposed to varying temperature and pressure levels to simulate realistic environmental and operational conditions. UGWs were excited and recorded using a distributed network of piezoelectric transducers attached to the surface of the specimen. Tests were repeated by introducing artificial and real damages on the vessel to evaluate their effect under similar conditions. The paper provides a brief overview of the experimental methodology, key results demonstrating the dataset’s scope and a short section on technical validation, including machine learning-based damage detection and localisation. Jan Heimann; Daniel Lozano; Houssam El Moutaouakil; Octavio Marques Reyes; Enes Savli; David Pöhlig; Jochen Moll; Peter Kraemer; Andreas Schütze; Jens Prager conferenceobject https://opus4.kobv.de/opus4-bam/frontdoor/index/index/docId/66763 Thu, 13 Aug 2026 06:08:11 +0200 https://opus4.kobv.de/opus4-bam/frontdoor/index/index/docId/66762 Subsociality and wood-eating or xylophagy are understood as key drivers in the evolution of eusociality in Blattodea (cockroaches and termites), two features observed in the cockroach genus Cryptocercus, the sister group of all termites. We analyze two high-quality genomes from this genus, C. punctulatus from North America and C. meridianus from Southeast Asia, to explore the evolutionary transitions to xylophagy and subsociality within Blattodea. Our analyses reveal evidence of relaxed selection in both Cryptocercus and termites, indicating that a reduction in effective population size may have occurred in their subsocial ancestors. These findings challenge the expected positive correlation between dN/dS ratios and social complexity, as Cryptocercus exhibits elevated dN/dS values that may exceed those of eusocial termites. Additionally, we infer a reduction in the number of Ionotropic Receptors and a change from uni- to bimodal methylation signatures in protein coding genes in a common ancestor of Cryptocercus and termites, mechanisms previously thought to have evolved with the emergence of eusociality in termites. Future studies incorporating additional genomic data from diverse blattodean species can further build on these findings and provide deeper insights into the molecular mechanisms driving transitions to xylophagy and eusociality. Alun R C Jones; Alina A Mikhailova; Cédric Aumont; Juliette Berger; Cong Liu; Shulin He; Zongqing Wang; Sylke Winkler; Erich Bornberg-Bauer; Frédéric Legendre; Dino Peter McMahon; Mark C Harrison article https://opus4.kobv.de/opus4-bam/frontdoor/index/index/docId/66762 Thu, 13 Aug 2026 06:07:03 +0200