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From silos to synergy: improving coordination in local flood management
No full textFlood risk governance has gained increasing attention as climate change and urbanization amplify flood risks. While much of the literature has focused on national and supranational governance frameworks, sectoral integration, and public participation, there remains a critical gap in understanding horizontal coordination within municipal administrations—particularly in medium-sized cities. This study examines how local governments coordinate flood risk management across different departments and administrative units, identifying key challenges and enabling factors. Using a case study of Mörfelden-Walldorf, a medium-sized city in southern Hesse, Germany, we analyze the internal governance dynamics shaping flood resilience. The research highlights institutional fragmentation, sectoral silos, and resource constraints as key barriers to effective coordination while also identifying mechanisms that facilitate cross-departmental collaboration. By integrating insights from the public administration literature with flood governance scholarship, this study contributes to a more nuanced understanding of local-level flood risk governance. The findings provide practical implications for enhancing municipal flood resilience through improved governance structures and coordination mechanisms
Simulating effectiveness of Low Impact Development (LID) for different building densities in the face of climate change using a hydrologic-hydraulic model (SWMM₅)
No full textTo date, few studies have been published for cities in Germany that take into account climate change and changing hydrologic patterns due to increases in building density. This study investigates the efficiency of LID for past and future climate in the polycentric agglomeration area Frankfurt, Main (Central Germany) using observed and projected climate (model) data for a standard reference period (1961–1990) and a high emission scenario (RCP 8.5) as well as a climate protection scenario (RCP 2.6), under 40 to 75 percent building density. LID elements included green roofs, permeable pavement and bioretention cells. SWMM5 was used as model for simulation purposes. A holistic evaluation of simulation results showed that effectiveness increases incrementally with LID implementation percentage and inverse to building density if implemented onto at least 50 percent of available impervious area. Building density had a higher adverse effect on LID efficiency than climate change. The results contribute to the understanding of localized effects of climate change and the implementation of adaption strategies to that end. The results of this study can be helpful for the scientific community regarding future investigations of LID implementation efficiency in dense residential areas and used by local governments to provide suggestions for urban water balance revaluation
Static Friction in Oil Lubricated Cold Forming Processes
No full textFriction is one of the variables that have a far-reaching influence on forming processes. In the past, less attention was paid to static friction than to sliding friction in forming processes. In this paper, a test stand for the determination of static friction under load in metal forming is presented. The results are discussed using the example of an oscillating cold forming process. It could be shown that the expected influence of static friction is low in this application
Heavy elements : They came out of the blue
No full textHow are the heavy elements formed? This has been a key open question in physics for decades. Recent direct detections of neutron star mergers and observations of evolved stars show signatures of chemical elements in the blue range of their spectra that bear witness of recent nuclear processes that led to heavy element production. The formation of heavy elements typically takes place through neutron-capture reactions creating radioactive isotopes, which following beta-decay turn into the stable isotopes we today can measure indirectly in the surfaces of cool, low-mass stars or meteoritic grains. The conditions (such as the neutron density or entropy) of these n-capture reactions remain to date poorly constrained, and only through a multidisciplinary effort can we, by combining and comparing observations, experiments, and theoretical predictions, improve on one of the top 10 most important open physics questions posed at the turn of the century. This emphasises the need for detailed observations of the near-UV to blue wavelength region. The shortage of spectrographs and hence spectra covering this range with high-resolution and high signal-to-noise has for decades played a limiting factor in our understanding of how heavy elements form in the nuclear reactions as well as how they behave in the stellar surfaces. With CUBES (Cassegrain U-Band Efficient Spectrograph) we can finally improve the observations, by covering the crucial blue range in more remote stars and also achieve a higher signal-to-noise ratio (SNR). This is much needed to detect and accurately deblend the absorption lines and in turn derive more accurate and precise abundances of the heavy elements
Bonding profiling of gapless ceramic V₂GaC/N MAX phases: a spectroscopic and dual theoretical approach
No full textThe family of MAX phases is growing faster than ever, resulting in more than 340 reported members so far. Even though the variety of different M- and A-elements is overwhelming, the X-site of MAX phases is still mainly dictated by solely carbide-based materials, while nitrogen-based materials, such as nitrides and (carbo)nitrides account for below 10% in total. It follows that more profound studies comparing those three classical MAX phase groups are rare in the literature, particularly in terms of combining computational considerations with high-resolution spectroscopic experiments. Here, we report the electronic properties of three vanadium-based MAX phases: V₂GaC, V₂GaN, and the (carbo)nitride phase V₂GaC₁₋ₓNₓ. This investigation is carried out for C/N K-edge and the V L-edge using soft X-ray absorption (XAS) and emission spectroscopy (XES). We determine the x value to be 0.6 in the (carbo)nitride V₂GaC₁₋ₓNₓ phase. Additionally, we determine V²˙²⁺ as the formal oxidation state in all three phases using ligand field multiplet theory (LFMT) calculations. Our density functional theory (DFT) calculations indicate the presence of carbon vacancies in the V₂GaC phase. DFT and LFMT theoretical methods confirm that the V₂GaC has a higher degree of covalency than the V₂GaN phase. Also, Gallium interactions are the weakest with C/N and are entirely metallic
Kulturelle Ursachen der Überbürokratisierung
No full textDie vorliegende Studie untersucht die in Deutschland vorherrschenden sozio-kulturellen Ursachen für Bürokratie und Überbürokratisierung und kommt unter anderem zu dem Ergebnis: Dort, wo es Spielräume bei Entscheidungen gibt, nutzt die Verwaltung sie nur sehr vorsichtig und zurückhaltend. Beim Entwurf neuer Vorschriften achten die Verantwortlichen zu wenig auf deren praktische Umsetzbarkeit. Die Studie richtet den Fokus auf die Mentalität von Mitarbeitern in der deutschen Verwaltung und Politik. Sie untersucht, inwiefern diese Haltung ein zentraler Schlüssel für den Abbau von Bürokratie ist – und welcher kulturelle Wandel in Behörden und Ministerien dafür notwendig wäre. Am Beispiel des Baurechts und des Baugenehmigungsverfahrens zeigt die Studie auf, wie stark bürokratische Hürden und strukturelle Schwächen insbesondere im Bauwesen zum Tragen kommen
A review of critical issues in the design of lightweight flywheel rotors with composite materials
No full textComposite materials are widely used to build high-performance flywheels due to their high material strength and low mass density. The high degrees of freedom in material selection, design, and manufacturing techniques lead to a variety of rotor structures. This paper presents the characteristics of different composite rotors and the critical considerations in terms of designing, manufacturing, and testing them. The introduction starts with the limitations of a single filament-wound composite rim. Then, various rotor structures are presented as well as the critical issues regarding the composite rim design, rim-shaft connection, and rotor failure in order to make safe design recommendations. The aim is to summarize the current techniques and provide references for further developments
When Feelings Meet Code: How Generative AI Affects the Emotions of Developers
No full textGenerative Artificial Intelligence (GenAI) is transforming professional workflows, particularly in programming, where tools like ChatGPT assist with code generation, debugging, and explanations. While GenAI enhances performance, concerns about the implications for well-being and emotions while working with GenAI persist. Especially emotions in terms of positive and negative feelings play a crucial role, influencing how effectively GenAI is utilized in professional settings. Our research explores the impact of GenAI on emotions of employees in a programming context. We conducted an online experiment with 161 Python programmers, assessing performance and positive and negative feelings with and without ChatGPT assistance on two different programming tasks by performing paired t-tests and a structural model analysis. The findings indicate that ChatGPT not only significantly improves performance but also demonstrates a link between positive emotions and enhanced outcomes. These findings highlight the importance of technical and emotional factors in maximizing the potential of human-AI collaboration
Effects of spatial variability on the axial load-bearing capacity of dry-stacked masonry walls
No full textUnlike conventional unreinforced masonry, dry-stacked masonry (DSM) walls exhibit structural behaviour influenced by distinct parameters. To thoroughly understand this behaviour, it is essential to analyse key factors such as compressive unit strength, interlocking mechanisms, and concrete's non-linear cracking and crushing behaviour. Wall slenderness, unit height variation, random stacking, and surface roughness also significantly affect performance. Therefore, this study uses experimentally validated non-linear finite element models to assess DSM walls under axial compression. Experimental data obtained using Digital Image Correlation techniques are used to calibrate and validate these models, allowing to perform stochastic analyses to understand the influence of model parameters on the axial load-bearing capacity of DSM walls. Focus is placed on unit height variation, wall slenderness, and contact roughness. A probabilistic method - combining Latin hypercube sampling with Monte Carlo simulations - is used to predict resistance distributions. This study aims to consider spatial variability in geometric parameters of DSM units, acknowledging that assuming a uniform height for masonry units could lead to unrealistic or inaccurate simulation outcomes in DSM. Unit heights are randomly sampled, and various wall heights are analysed to assess slenderness effects, showing a clear capacity reduction with increasing slenderness. Surface roughness variations are modelled within a defined range, combined with random unit height distributions. For the first time, the study reveals how tilting and seating effects in individual units enhance load percolation and overall DSM wall strength. The analysis also identifies damage patterns and failure modes, and the semi-probabilistic approach enables prediction of compressive capacity distributions and design values, accounting for wall slenderness
Hochtemperaturfestigkeit von geglühtem Kalk‐Natronsilicatglas
No full textBei der additiven Fertigung und beim thermischen Vorspannen von Glas ist dessen Festigkeit für den aufgrund des Herstell‐ bzw. Veredelungsprozesses relevanten Temperaturbereich nur wenig erforscht. Um die Auswirkungen unterschiedlicher Temperaturen auf die Festigkeit des Werkstoffs näher bestimmen zu können, wurde der Doppelringbiegeversuch nach EN 1288‐5 mit einer Universalprüfmaschine mit Ofen an Glasplatten von Raumtemperatur bis 550 °C durchgeführt. Vor der Prüfung wurden die Proben kontrolliert vorgeschädigt, gelagert und mit Wärme behandelt. Die Ergebnisse zeigen eine Zunahme der Bruchfestigkeit mit steigender Prüftemperatur. Der kritische Spannungsintensitätsfaktor und die kritische Energiefreisetzungsrate zeigen keine Temperaturabhängigkeit