Offenburg University of Applied Sciences
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Isothermal Membrane Distillation: Concept Validation and Membrane Characterization
No full textDrinking water scarcity is a major global concern, emphasizing the critical need for energy-efficient desalination technology. This study presents proof of concept of a novel Isothermal Membrane Distillation (ID) process as a possible low-energy alternative supported by detailed characterization of membranes. The process is driven by the coupling of conventional Membrane Distillation (MD) with capillary condensation and electro-osmotic flow (EOF). A test bench setup was designed based on Direct Contact Membrane Distillation (DCMD) configuration to evaluate the feasibility of this concept. PTFE, PVDF and PES hydrophilic membranes along with titanium PTL were characterized using Water Contact Angle (WCA) measurements, permeability tests, and SEM/EDS analysis. PVDF/PVDF membrane configuration performed better than PTFE/PES and PTFE/PVDF configurations, producing a permeate flow rate of 0.55 µL/min, 0.49 µL/min and 0.37 µL/min respectively. Experimental trials indicated that significant water production occurred only under an applied electric field, establishing EOF as the predominant condensed water transport mode. At 6 V, stable permeate generation was achieved even without membrane priming while with membrane priming an average product of 1.48 mL in 24 h and 2.16 mL in 40 h was achieved. A mass transfer model was developed to simulate vapor diffusion, capillary condensation, and EOF-driven condensate in order to study how applied voltage affects permeate production in a PVDF/PVDF membrane stack. The results showed a nearly linear rise in water flux as voltage increased showing good qualitative agreement with experiments. Despite the current trade-off of reduced flux, this study successfully demonstrates the essential principles of an IMD process, highlighting its potential as a sustainable alternative
Determinants of footwear perception in running shoes with different compression stiffnesses
Get PDFRunning shoe midsole cushioning is critical in comfort perception and running performance. Optimizing the midsole stiffness could help reduce injury risk and enhance performance by aligning shoe properties with individual runner preferences. Therefore, this study aimed to explore the multifactorial relationships between biomechanical, physiological, sensorimotor, and socio-cultural factors influencing individual perceptions of shoes with varying midsole cushioning stiffnesses. Nineteen participants performed treadmill runs in two shoe conditions with varying midsole stiffness. Biomechanical and metabolic data, as well as subjective assessments of comfort, cushioning, and stability, were collected. The results revealed that stability perception was primarily driven by a socio-cultural factor, stability importance (β = −0.74, p < 0.01), and a biomechanical parameter, step frequency (β = −0.56, p = 0.04), collectively explaining 56% of variance (p = 0.03). In contrast, neither cushioning perception nor comfort perception could be significantly predicted by any biomechanical, physiological, sensorimotor or socio-cultural variables (p = 0.31 − 0.83). Overall, our findings suggest that parameters across different domains (biomechanical, physiological, sensorimotor, and socio-cultural) may determine the perception of shoe stability in runners. The strong relationships with individual attitudes and biomechanical parameters underscore the need for personalized approaches in running shoe cushioning design. Furthermore, since such attitudes can be shaped, e.g. through marketing initiatives, these findings highlight the importance of a proper alignment between marketing claims and biomechanical findings relating to injury risk and performance improvements through midsole characteristics
KI in der Games-Branche
No full textSeit ihren Anfängen nutzen Videospiele Künstliche Intelligenz (KI). Von der Entwicklung realistischer Charaktere über die Generierung dynamischer Spielwelten bis hin zu personalisierten In-Game-Verkäufen verspricht KI fast unbegrenzte Möglichkeiten. Dieses Kapitel beleuchtet die vielfältigen Anwendungsbereiche von KI in Game Design und Game Development, in Spielevermarktung und Monetarisierung sowie in Gamification und E-Sport. Dabei setzt es sich kritisch mit früheren und aktuellen Entwicklungen auseinander und vergleicht die Auswirkungen der aktuellen KI-Revolution mit früheren massiven Verwerfungen in der Games-Branche
Pyrolysis as a strategic element in energy system transformation to achieve net zero emissions
No full textThis study evaluates pyrolysis as a dual-purpose technology for integrating negative emissions and dispatchable electricity into Germany’s power system, supporting climate neutrality by 2045. Using a myopic power system model, we assess the role of pyrolysis, which operates solely on residual biomass. By 2050,pyrolysis can reach an installed capacity of 5 GW, supplying 2 % of total electricity generation. Its flexible power output reduces the need for hydrogen storage by 60 %, as it generates electricity during low renewable supply periods and offsets CO2 emissions from gas-fired power plants through biochar sequestration. This enables continued gas plant operation without new investments while maintaining a net-negative CO2 balance. Pyrolysis deployment is closely linked to solar PV availability, expanding earlier in high-solar regions, and its integration increases battery storage capacity by 240 %. The expansion of pyrolysis is driven by investment costs (CAPEX) and electricity demand, with lower CAPEX—below 308 €/(tBM/year) for pyrolysis plants and 2,300 €/kWel for power generation units—accelerating deployment. Rising electricity demand enhances pyrolysis’ role as a flexible power source, even under high CAPEX conditions. These findings highlight pyrolysis as a strategic enabler of energy system decarbonization, uniquely combining dispatchable renewable electricity and negative emissions.
Its integration underscores the need for a diversified power plant portfolio to maintain system flexibility and stability, providing essential insights for policymakers, investors, and energy planners on optimizing market frameworks and deployment strategies
Analyse von Cybervorfällen
No full textNach der Vorstellung des Risikomodells und der Darstellung der Bedrohungslandschaft geht es im zweiten Teil um die Schwachstellen eines Unternehmens mittels des OWASP Top 10 Rahmenwerks, die Sicherheitskontrollen auf der Grundlage des CIS-Modells Version 8.1 und die potenziellen negativen Auswirkungen auf die organisatorischen Vermögensgegenstände. Im Verlauf der Argumentation wird herausgearbeitet, wie die Bedrohungen mögliche Schwachstellen und fehlerhafte beziehungsweise fehlende Kontrollen für sich ausnutzen können, wodurch ein schadhaftes Ereignis erst möglich wird. Das Risikomodell wird dann mit der Ursachenanalyse verbunden. Letztere greift im Kern auf eine Vielzahl von Techniken zur Bestimmung der Gründe von Vorfällen zurück, von denen drei vorgestellt werden. Den Abschluss bilden eine Darstellung und kritische Betrachtung des Crowdstrike- Vorfalls auf der Grundlage verfügbarer Informationen
Temperature control and optimization of an adsorption setup
No full textThis thesis focuses to address the challenges of achieving stable and accurate temperature control in a laboratory adsorption setup that is intended for teaching purposes. The setup separates CO₂ from N₂ using activated carbon. During experiments, it exhibited overshoot, oscillations, and heat losses that complicated experimental observations. To better understand and improve the setup, experimental investigations were first carried out to evaluate temperature distribution, sensor accuracy, and breakthrough behavior at different operating conditions. It was found that structural heat losses through the column ends were the main cause of uneven temperature profiles. Two models were developed to analyze the system dynamics. First model describing the relationship between controller output and heating jacket temperature, and second model linking jacket temperature to column temperature. These models were identified and validated in MATLAB/Simulink and enabled both open-loop and closed-loop simulations. While the open-loop behavior was represented successfully, closed-loop simulations under proportional-only control showed a mismatch with experimental results, suggesting unmodeled dynamics. Experimental PID tuning showed that proportional-only settings yielded the most stable and practical performance, supported by the introduction of a correction factor between jacket and column temperatures. The main contributions of this work include the identification of limitations in system modeling, development of a correction approach for improved control, and recommendations for refining student procedures. The findings highlight the importance of precise thermal management in adsorption experiments and provide a foundation for future improvements, such as cascaded control structures and sensor-lag modeling, to further improve stability and accuracy
BMFTR Projekt KI-Bohrer - KI-Steuerung zur Schallreduktion bei innerstädtischen Geothermie Bohrungen in Kooperation mit der Herrenknecht Vertical GmbH
No full textDie Nutzung geothermischer Energie in urbanen Räumen gewinnt zunehmend an Bedeutung und gilt als wesentlicher Baustein zur Erreichung internationaler Klimaziele. Der Einsatz entsprechender Technologien in Städten ist jedoch mit Herausforderungen verbunden – insbesondere durch die erhebliche Lärmbelastung, die beim Bohren entsteht. Bisherige Ansätze zur Lärmminderung sind meist manuell gesteuert und erweisen sich häufig als unzureichend, um die strengen gesetzlichen Grenzwerte im städtischen Umfeld einzuhalten. In dicht besiedelten Gebieten führen die für die Energiegewinnung notwendigen anfänglichen Tiefbohrungen oft zu starken Beeinträchtigungen der Anwohner. Vor allem die nächtlichen Lärmgrenzwerte von etwa 35 dB stellen angesichts eines durchgängigen 24/7-Betriebs eine erhebliche Hürde dar. Klassische Maßnahmen wie zeitliche Verschiebungen oder der Einsatz physischer Barrieren bieten nur begrenzte Wirkun
Hydrogen-ready power plants: Optimizing pathways to a decarbonized energy system in Germany
Get PDFThe integration of hydrogen technologies is widely regarded as a transformative step in the energy transition. Recently, the German government unveiled a Power Plant Strategy to promote H2-Ready Combined-Cycle Gas Turbines (H2-CCGT), which are intended to initially run on natural gas and transition to green hydrogen by 2040 at the latest. This study assesses the role of H2-Ready power plants in a low-carbon transition and explores plausible pathways using a capacity expansion model for Germany. This topic is particularly relevant for other countries aiming to deploy a large share of renewables and considering H2-CCGT as a flexible backup solution to ensure system flexibility and achieve deep decarbonization. Our results indicate that H2-CCGT enhance system flexibility and significantly alleviate the investments need for additional flexibility and renewable generation capacity, and reduce renewable-energy curtailment by more than 35 %. Moreover, our results also demonstrate that allowing hydrogen in CCGT does not entirely reduce the need for fossil fueled power plants, as hydrogen becomes economically viable only with deep decarbonization or direct subsidies. We show that policy interventions can alter the transition pathways for achieving a decarbonized energy system. Our research challenges a prevailing narrative that financial support for hydrogen is needed to ensure a cost-efficient system decarbonization. More straightforward market-based policy instruments, such as intensified CO2 pricing, or regulatory frameworks such as earlier mandatory hydrogen shifts in H2-CCGT prove more efficient at cutting emissions and costs
Parallel Impedivity Measurements for Enzyme Activity Quantification in Microtiter Plates for Calcite Precipitation Research
No full textConductometry is a widely used technique in enzyme studies as it allows researchers to monitor the activity of enzymes in solution. The determination of enzymatic activity, a time-dependent parameter, inherently takes several minutes, making it time-consuming to measure multiple samples with traditional methods. To overcome these limitations, we present a device for efficient, parallel, impedimetric measurement of urease activity. In this study, urease is representative of all enzymes that catalyze hydrolysis reactions leading to ion formation. The results show the general applicability of the device for parallelized measurement of urease activity. Further optimization is required to ensure accuracy, reliability, and reusability of the measurement set-up. Overall, at this point of development, the 24-well microplate setup is a promising tool for fast and easy enzyme activity determination, with potential applications in enzyme-based diagnostics development or geotechnical engineering and research
Optimising AI-driven solutions without trade-offs: predicting and preventing potential failures in sustainable innovation
Get PDFThe application of Generative Artificial Intelligence (AI) in early-stage design processes has emerged as a promising method for generating innovative solution concepts. However, AI-driven concepts may introduce secondary problems when implemented practically. This study proposes a systematic framework integrating Generative AI (GPT-4o), patent analysis using Retrieval-Augmented Generation (RAG), and Failure Mode and Effects Analysis (FMEA) to predict, evaluate, and mitigate potential risks. Applied to a case study on nickel recovery through froth flotation, the framework significantly enhanced the feasibility, usefulness, and sustainability of solution concepts. The research highlights the scientific contribution and practical benefits of combining Generative AI with structured risk-analysis methods for sustainable innovation