RWE (Germany)

Characterizing the crustal stress state and its spatial variability is essential for the safe and sustainable development of structurally controlled deep geothermal systems. The seismically active Lower Rhine Graben (LRG), spanning parts of Germany, Belgium, and the Netherlands, is a promising target for geothermal exploitation in fault-controlled, karstified carbonate reservoirs of Lower Carboniferous and Devonian age. However, at drillable depths, the stress field remains poorly constrained, raising concerns regarding fault reactivation and induced seismicity, as highlighted by moderate induced events at recent deep geothermal projects in Belgium and the Netherlands.We present a quality-rated crustal stress database for the LRG and adjacent regions, integrating legacy and newly acquired stress indicators from earthquakes and recently drilled exploratory boreholes. Stress tensor inversion was performed using recent earthquake focal mechanisms, while borehole-based indicators from hydraulic fracturing tests and borehole deformation analyses provided direct constraints on stress orientations and absolute stress magnitudes at reservoir-relevant depths. These data were combined with publicly available present-day stress indicators from existing databases, and interpolated onto a regular 0.1° grid to generate a gridded stress field capturing regional-scale, long-wavelength variability.The spatially variable stress field was integrated with mapped major faults to evaluate their reactivation potential by assigning stress orientations to individual fault segments. Our results indicate a clockwise rotation of the maximum horizontal stress from WNW–ESE in the Hohe Venn area west of the graben to NNW–SSE in the Rhenish Massif to the east. At geothermal reservoir depths, NW–SE-striking normal faults show elevated potential for shear reactivation and dilation, whereas NE–SW-striking thrust faults exhibit low potential for both mechanisms.By integrating more than 135 stress indicators into a spatially resolved fault reactivation analysis, this study substantially increases stress data coverage in the region and provides quantitative constraints on fault stability and seismic hazard relevant for geothermal development, supporting site selection and risk-informed reservoir management in the tectonically active LRG.

The phenomenon of rain-wind-induced vibrations has become more and more important not only for cable stayed bridges but also for vertical hangers of arc bridges and cables of suspended large roofs. Several investigations have been undertaken to clearify the exciting mechanism starting with the pioneering work of Hikami/Shiraishi 1988 up to the most plausible explanation given by Verwiebe 1998, who also proposed a rough estimation for the calculation of the expected vibration amplitude. There is a three mass aero-hydro-elastic interaction between the vibrating cable, the wind and the oscillating water rivulet which induces the exciting forces. The different rivulet configurations induce different vibration modes — in-wind and cross-wind direction. Model tests as well as full-scale observations (Luesse et.al. 1996) show the range of significant excitations depending on the inclination of the cables, the natural frequency of the cable, the wind speed, the wind direction and the structural damping. A first step for the development of a mathematical model for the practical application of the prediction of the vibration amplitude is presented.

Viele Menschen sind beunruhigt. Der Krieg in der Ukraine, die Auseinandersetzungen im Nahen Osten und anderen Teilen der Welt, die politischen Entwicklungen in den USA und die Auswirkungen des Klimawandels tragen dazu bei. Auch die Coronavirus-Pandemie liegt noch nicht lange zurück: Wir leben also in einer Zeit, in der von Multi- oder Poly-Krisen gesprochen wird – in einer Zeit, in der ständig neue Krisen auftreten, die sich teilweise auch noch bedingen, vermengen oder überlagern.

Degradation of amine-based CO2 capture solvents causes not only higher solvent consumption but also more effort for controlling the emissions of volatile degradation products and for the removal of degradation products that are accumulating in the solvent. Guiding principles to minimize degradation processes generally are targeting at the reduction of oxidative and thermal stress for the solvent during the operation of the capture plant. For example, it is recommended to reduce the contact of potentially aggressive compounds in the flue gas, like O2 and NO2, with the amines as much as possible by their removal from the flue gas or the solvent. Additionally, the maximum temperature of the CO2-loaded solvent in the reboiler and desorber sump and the time of exposure should be minimized. The results of testing campaigns with the CESAR1 solvent at the pilot plant at Niederaussem show that the effects of elevated O2 and NO2 contents in the flue gas (increase from 5 to 16 vol % O2 and from <0.1 to >53 mg/m3 NO2) and of an elevated solvent regeneration temperature (increase from 120 to 130 °C) are small.

BackgroundPediatric emergencies are a challenge for emergency medical service (EMS) personnel regarding medical expertise and equipment. To address the special requirements in terms of size and weight, attempts are being made to systematically structure pediatric emergency backpacks.ObjectivesThe aim of the study was to compare two pediatric emergency backpacks. One structured according to the xABCDE-system, the other to the Broselow-system based on patients’ measurements.MethodsIn total, 115 participants underwent exercises and emergency scenario simulations with two pediatric emergency backpack systems in a prospective, randomized study. First, they performed a material search of six items to test the intuitiveness of both backpack systems. Later, they used the backpacks in the simulation of a pediatric resuscitation and carried out self-assessment and backpack system evaluation.ResultsThe handling of the Broselow-system was easier for the participants. Particularly size-specific materials (laryngeal mask (xABCDE vs. Broselow: 61.2 ± 31.3 vs. 24.5 ± 14.2 s, p < 0.001)), but also other materials (Magillpliers (37.2 ± 23.3 vs. 7.9 ± 6.1 s, p < 0.001), peripheral venous catheter (12.7 ± 5.7 vs. 6.6 ± 2.7 s, p < 0.001), pupil lamp (both 17.9 ± 6.9 vs. 16.0 ± 6.9 s, p < 0.05)) were found faster. The participants were faster in the resuscitation simulation and selection of large-scale measures using the Broselow-system (e.g. laryngeal mask (187.6 ± 72.6 vs. 155.1 ± 63.5 s, p = 0.001) and preparation of the medication administration in the appropriate dosage (243.0 ± 73.9 vs. 219.8 ± 60.2 s, p < 0.05)) and rated the Broselow-system as well as their own performance better in all evaluation categories (p < 0.001).Conclusions: As the Broselow-system coded according to size and weight was ranked better in practical application and evaluation, the size and weight-based sorting should be preferred to pure xABCDE systems. The comparison of the different backpack systems should further be tested in more complex simulations and real operations.What is known?•In emergency medicine, patient care follows the structured xABCDE approach to prioritize life-saving interventions. This algorithm is established in both prehospital and in-hospital settings.What is new?• We present the first comparison of two pediatric emergency backpacks structured by the xABCDE algorithm. Both systems were tested in 2 exercises (material search & resuscitation simulation) in randomized order. Participants completed questionaries on the backpacks and their own performance.

Metallic materials, predominantly steels, are the most common structural materials in the various components along the hydrogen supply chain. Ensuring their sustainable and safe use in hydrogen technologies is a key factor in the ramp-up of the hydrogen economy. This requires extensive materials qualification, however, most of the accepted; and standardized test methods for determining the influence of gaseous hydrogen on metallic materials describe complex and costly procedures that are only available to a very limited extent worldwide. The hollow specimen technique is a simple, rapid, and economical method designed to overcome the limitations of the current methods for the qualification of metallic materials under high-pressure hydrogen gas. However, this technique is not yet standardized. The TransHyDE-H2Hohlzug project is presented in this article, along with the main steps required to optimize the hollow specimen technique. This includes closing knowledge gaps related to the specimen geometry, surface quality, and gas purity in dedicated working packages, thus contributing to a comprehensive standardization of the technique for tests in high-pressure hydrogen gas.Impact statementThe hydrogen economy is considered a key solution for achieving climate neutrality in Europe, as it plays a crucial role in the decarbonization of sectors such as transport, industry, power, etc. Ensuring the safety and reliability of infrastructure is crucial for the ramp-up of the hydrogen economy. Therefore, it is necessary to meticulously study the materials and components used for infrastructure under conditions that closely resemble in-service conditions. The currently standardized methods are limited as they do not precisely replicate in-service conditions, and when they do, they are often complex, costly, and not easily accessible. This article presents the hollow specimen technique, a simple, and economical method developed to address the limitations of current standardized methods. The results from this work will contribute to the standardization of this technique for tests in high-pressure hydrogen gas. This will enable a faster evaluation of materials for hydrogen applications by industry and academia, thereby contributing to the growth of the hydrogen economy.Graphical abstract

TOPCon is set to become the new mainstream cell technology despite considerable reliability concerns. This work compares commercially available full-scale TOPCon PV module types from 5 different manufacturers in a variety of electrical characterization, accelerated aging tests and (for some selected types) outdoor exposure. This case study represents a selection process of PV modules for larger PV installations. Therefore, the work features an in-depth comparison of the electrical performance (Energy Rating) that can serve as a reference for state-of-the-art TOPCon modules. The preliminary aging results confirm previously reported degradation mechanisms of the TOPCon technology due to humidity and UV stresses. Where possible, connections to the used bill of materials, with focus on the encapsulant, are drawn. In the case of UV aging, a new pattern of strong degradation (up to 12 % after <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$60 \text{kWh}/\mathrm{m}^{2}$</tex>) and subsequent recovery after humidity freeze-test is presented, which could have implications on the results of certification tests (IEC61730-2, Sequence B). The outdoor exposure is used to evaluate the development of this failure pattern under realistic outdoor conditions, for different operation conditions. Finally, areas of demand for more focused testing and technological development are highlighted.