@article{GaertnerMarxSchubachGadereretal., author = {G{\"a}rtner, Sebastian and Marx-Schubach, Thomas and Gaderer, Matthias and Schmitz, Gerhard and Sterner, Michael}, title = {Techno-Economic Analysis of Carbon Dioxide Separation for an Innovative Energy Concept towards Low-Emission Glass Melting}, series = {energies}, volume = {16}, journal = {energies}, number = {5}, publisher = {MDPI}, address = {Basel}, doi = {10.3390/en16052140}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:898-opus4-53627}, pages = {1 -- 25}, abstract = {The currently still high fossil energy demand is forcing the glass industry to search for innovative approaches for the reduction in CO2 emissions and the integration of renewable energy sources. In this paper, a novel power-to-methane concept is presented and discussed for this purpose. A special focus is on methods for the required CO2 capture from typical flue gases in the glass industry, which have hardly been explored to date. To close this research gap, process simulation models are developed to investigate post-combustion CO2 capture by absorption processes, followed by a techno-economic evaluation. Due to reduced flue gas volume, the designed CO2 capture plant is found to be much smaller (40 m3 absorber column volume) than absorption-based CO2 separation processes for power plants (12,560 m3 absorber column volume). As there are many options for waste heat utilization in the glass industry, the waste heat required for CO2 desorption can be generated in a particularly efficient and cost-effective way. The resulting CO2 separation costs range between 41 and 42 EUR/t CO2, depending on waste heat utilization for desorption. These costs are below the values of 50-65 EUR/t CO2 for comparable industrial applications. Despite these promising economic results, there are still some technical restrictions in terms of solvent degradation due to the high oxygen content in flue gas compositions. The results of this study point towards parametric studies for approaching these issues, such as the use of secondary and tertiary amines as solvents, or the optimization of operating conditions such as stripper pressure for further cost reductions potential.}, language = {en} } @article{ZacherlWopperSchwanzeretal., author = {Zacherl, Florian and Wopper, Christoph and Schwanzer, Peter and Rabl, Hans-Peter}, title = {Potential of the Synthetic Fuel Oxymethylene Ether (OME) for the Usage in a Single-Cylinder Non-Road Diesel Engine: Thermodynamics and Emissions}, series = {Energies}, volume = {15}, journal = {Energies}, number = {21}, publisher = {MDPI}, doi = {10.3390/en15217932}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:898-opus4-55350}, pages = {1 -- 26}, abstract = {Non-road sectors, such as agriculture and construction machinery, require high energy densities and flexibility in use, which is why diesel engines are mainly used. The use of climate-neutral fuels, produced from renewable energies, such as Oxymethylene Ether (OME) as a diesel substitute, can significantly reduce CO2 and pollutant emissions in these sectors. In addition to CO2 neutrality, OME also offers improved combustion characteristics compared to diesel fuel, eliminating the soot-NOx trade-off and thus enabling new opportunities in engine design and calibration. In this paper, the combustion of pure OME on a close-to-production, single-cylinder non-road diesel engine with a pump-line-nozzle injection system is analyzed. A variation of the center of combustion at constant power output was performed for diesel and OME at different operating points. Two injectors were investigated with OME. A study on ignition delay and a detailed thermodynamic analysis was carried out. In addition, the exhaust emissions CO, NOx, VOC, as well as particulate-matter, -number and -size distributions were measured. With OME, a significantly shorter ignition delay as well as a shortened combustion duration could be observed, despite a longer injection duration. In addition, the maximum injection pressure increases. VOC and CO emissions are reduced. Particulate matter was reduced by more than 99\% and particle number (>10 nm) was reduced by multiple orders of magnitude. The median of the particle size distribution shifts from 60 to 85 nm (diesel) into a diameter range of sub 23 nm (OME). A significant reduction of NOx emissions with OME enables new degrees of freedom in engine calibration and an efficiency advantage without hardware adaption.}, language = {en} } @article{TroidlSchrollDecker, author = {Troidl, Kilian and Schroll-Decker, Irmgard}, title = {Wie theoriebasiert sind Forschungsbeitr{\"a}ge zur Bildungsbeteiligung? Eine Qualitative Inhaltsanalyse ausgew{\"a}hlter Fachzeitschriften der Erwachsenen- und Weiterbildungsforschung}, series = {Zeitschrift f{\"u}r Weiterbildungsforschung}, volume = {45}, journal = {Zeitschrift f{\"u}r Weiterbildungsforschung}, publisher = {Springer Nature}, doi = {10.1007/s40955-022-00229-3}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:898-opus4-55460}, pages = {19}, abstract = {In der Vergangenheit wurde beklagt, dass in der empirischen Forschung zur Bildungsbeteiligung Erwachsener selten eine Integration von Theorie und Empirie erfolge und die mangelnde empirische Pr{\"u}fung eine theoretische Weiterentwicklung des Forschungsfeldes erschwere. Mittels einer Qualitativen Inhaltsanalyse von Beitr{\"a}gen ausgew{\"a}hlter Fachzeitschriften der Erwachsenen‑/Weiterbildungsforschung wurde versucht, die Aktualit{\"a}t dieser Feststellung empirisch zu {\"u}berpr{\"u}fen. Dazu wurden 38 empirische Forschungsbeitr{\"a}ge zur Bildungsbeteiligung der Jahrg{\"a}nge 2018 bis 2020 von neun Fachzeitschriften mit Peer-Review untersucht. Die Einsch{\"a}tzung der Beitr{\"a}ge erfolgte hinsichtlich des Grades der Theorieeinbindung. Die Ergebnisse der Analyse zeigen ein gemischtes Bild: neun Beitr{\"a}ge (24 \%) binden keine Theorie in den Forschungsprozess ein, ein Beitrag (3 \%) zitiert Theorie lediglich, ohne sie weiter einzubinden. Am h{\"a}ufigsten ist eine Einbindung zum theoriegeleiteten Vorgehen (16 Beitr{\"a}ge, 42 \%). Eine tiefergehende Theorieanwendung findet sich in sechs Beitr{\"a}gen (16 \%). Eine theoriepr{\"u}fende oder -bildende Einbindung liegt mit je drei Beitr{\"a}gen (je 8 \%) seltener vor. Die rezipierten Theorien sind vielf{\"a}ltig: es werden 20 verschiedene Theorieans{\"a}tze festgestellt. Den Forderungen nach einer verst{\"a}rkten Einbindung von Theorie in den Forschungsprozess kann somit weiterhin G{\"u}ltigkeit attestiert werden: ein substanzieller Teil der Beitr{\"a}ge berichtet keine Theorieeinbindung, eine empirische Pr{\"u}fung oder Weiterentwicklung findet relativ selten statt.}, subject = {Erwachsenenbildung}, language = {de} } @article{SchoenbergerScherzingerMauerer, author = {Sch{\"o}nberger, Manuel and Scherzinger, Stefanie and Mauerer, Wolfgang}, title = {Ready to Leap (by Co-Design)? Join Order Optimisation on Quantum Hardware}, series = {Proceedings of the ACM on Management of Data, PACMMOD}, volume = {1}, journal = {Proceedings of the ACM on Management of Data, PACMMOD}, number = {1}, publisher = {ACM}, address = {New York, NY,}, doi = {10.1145/3588946}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:898-opus4-56634}, pages = {1 -- 27}, abstract = {The prospect of achieving computational speedups by exploiting quantum phenomena makes the use of quantum processing units (QPUs) attractive for many algorithmic database problems. Query optimisation, which concerns problems that typically need to explore large search spaces, seems like an ideal match for the known quantum algorithms. We present the first quantum implementation of join ordering, which is one of the most investigated and fundamental query optimisation problems, based on a reformulation to quadratic binary unconstrained optimisation problems. We empirically characterise our method on two state-of-the-art approaches (gate-based quantum computing and quantum annealing), and identify speed-ups compared to the best know classical join ordering approaches for input sizes that can be processed with current quantum annealers. However, we also confirm that limits of early-stage technology are quickly reached. Current QPUs are classified as noisy, intermediate scale quantum computers (NISQ), and are restricted by a variety of limitations that reduce their capabilities as compared to ideal future quantum computers, which prevents us from scaling up problem dimensions and reaching practical utility. To overcome these challenges, our formulation accounts for specific QPU properties and limitations, and allows us to trade between achievable solution quality and possible problem size. In contrast to all prior work on quantum computing for query optimisation and database-related challenges, we go beyond currently available QPUs, and explicitly target the scalability limitations: Using insights gained from numerical simulations and our experimental analysis, we identify key criteria for co-designing QPUs to improve their usefulness for join ordering, and show how even relatively minor physical architectural improvements can result in substantial enhancements. Finally, we outline a path towards practical utility of custom-designed QPUs.}, language = {en} } @article{KaessStrahringerWestner, author = {K{\"a}ss, Sebastian and Strahringer, Susanne and Westner, Markus}, title = {Practitioners' Perceptions on the Adoption of Low Code Development Platforms}, series = {IEEE Access}, journal = {IEEE Access}, publisher = {IEEE}, issn = {2169-3536}, doi = {10.1109/ACCESS.2023.3258539}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:898-opus4-59170}, pages = {30}, abstract = {Organizations are under increasing pressure to develop applications within budget and time at high quality. Therefore, multiple organizations adopt Low Code Development Platforms (LCDP) to develop applications faster and cheaper compared to traditional application development. However, current research on LCDP adoption lacks empirical grounding as well as a deeper understanding of the importance of adoption drivers and inhibitors. We conducted semi-structured interviews and a Delphi study with seventeen experts to address these gaps. As a result, we identified twelve drivers and nineteen inhibitors for adopting LCDPs. We show that the experts have a consensus on the most and the least important drivers and inhibitors for LCDP adoption. Yet, the ranking of the drivers and inhibitors between the most and least important is highly context dependent. For some drivers and inhibitors, the experts' ranking is similar to academic literature, whereas, for others, it differs. In conclusion, the study at hand empirically validates drivers and inhibitors for LCDP adoption, adds six new drivers and six new inhibitors to the body of knowledge, and analyses the importance of these factors.}, language = {en} } @article{DotterHaugWeberetal., author = {Dotter, Caroline and Haug, Sonja and Weber, Karsten and Schnell, Rainer and Scharf, Anna and Altenburcher, Amelie}, title = {Analyzing factors determining vaccination willingness against COVID-19 in Germany 2020}, series = {Vaccine: X}, volume = {14}, journal = {Vaccine: X}, publisher = {Elsevier}, doi = {10.1016/j.jvacx.2023.100342}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:898-opus4-62900}, pages = {6}, abstract = {The study is based on a German single-topic population survey on vaccination willingness against COVID-19 (VWC) by the authors (2020, n = 2014). The single-topic survey allowed us to test several competing explanations for VWC, as discussed in the literature. The VWC in the sample was 67.3\%. Logistic regression was used to identify factors affecting VWC. Being at high risk from COVID-19 and having received flu vaccination have a positive impact on VWC. Perceived VWC of friends has a strong positive effect on respondents' VWC. Bivariate relationships of gender, age, and level of education with VWC were no longer significant in a multivariate analysis. Trust in alternative medicine and belief in conspiracy theories have a negative effect on VWC.}, language = {en} } @article{PangerlSukulRuecketal., author = {Pangerl, Jonas and Sukul, Pritam and R{\"u}ck, Thomas and Fuchs, Patricia and Weigl, Stefan and Miekisch, Wolfram and Bierl, Rudolf and Matysik, Frank-Michael}, title = {An inexpensive UV-LED photoacoustic based real-time sensor-system detecting exhaled trace-acetone}, series = {Photoacoustics}, volume = {38}, journal = {Photoacoustics}, publisher = {Elsevier}, issn = {2213-5979}, doi = {10.1016/j.pacs.2024.100604}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:898-opus4-71279}, pages = {12}, abstract = {n this research we present a low-cost system for breath acetone analysis based on UV-LED photoacoustic spectroscopy. We considered the end-tidal phase of exhalation, which represents the systemic concentrations of volatile organic compounds (VOCs) - providing clinically relevant information about the human health. This is achieved via the development of a CO2-triggered breath sampling system, which collected alveolar breath over several minutes in sterile and inert containers. A real-time mass spectrometer is coupled to serve as a reference device for calibration measurements and subsequent breath analysis. The new sensor system provided a 3σ detection limit of 8.3 ppbV and an NNEA of 1.4E-9 Wcm 1Hz 0.5. In terms of the performed breath analysis measurements, 12 out of 13 fell within the error margin of the photoacoustic measurement system, demonstrating the reliability of the measurements in the field.}, language = {en} } @article{AlbrechtHellerbrandWeiningeretal., author = {Albrecht, Sophie Viktoria and Hellerbrand, Stefan and Weininger, Florian and Thiel, Charlotte}, title = {Strategies for Minimizing Environmental Impact in Construction: A Case Study of a Cementitious 3D Printed Lost Formwork for a Staircase}, series = {materials}, volume = {18}, journal = {materials}, publisher = {MDPI}, doi = {10.3390/ma18040825}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:898-opus4-79236}, pages = {18}, abstract = {The construction industry faces significant challenges, including environmental sustainability, rising material costs, and a shortage of skilled labor. Digital fabrication technologies offer innovative solutions to address these issues by reducing raw material consumption and waste generation. Among these, 3D printing technologies offer distinct advantages over traditional construction methods, particularly in handling complex geometries. However, the significant environmental impact of cement in 3D printed concrete, due to its high rheological and printability requirements, remains a concern. This study introduces a novel application of 3D printed permanent formwork in the construction of a winder staircase, assessed through an Environmental Life Cycle Assessment (LCA) from cradle to gate. By comparing the environmental impacts of various construction materials and processes, this study highlights the comparative advantages and disadvantages of conventional methods versus 3D printing. The LCA results reveal that traditional production methods, particularly those using plywood formwork, exhibit higher environmental impacts. In contrast, timber formwork performs better than most 3D printed mixtures in terms of Global Warming Potential (GWP), Acidification Potential (AP), and abiotic depletion potential (ADP). The findings of this study underscore the potential of additive manufacturing for sustainable construction, particularly through the use of low-clinker cement in 3D printed formwork, offering a promising pathway towards reducing the environmental footprint of construction activities}, language = {en} } @article{WestnerReichenederMatschi, author = {Westner, Markus and Reicheneder, Matthias and Matschi, Markus}, title = {From Captive Centers to Global Integration}, series = {Information Resources Management Journal}, volume = {38}, journal = {Information Resources Management Journal}, number = {1}, publisher = {IGI Global}, issn = {1533-7979}, doi = {10.4018/IRMJ.373322}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:898-opus4-80406}, pages = {25}, abstract = {Contemporary developments in virtual work and global talent management are transforming information technology (IT) nearshoring and offshoring practices, yet research on organizational responses remains limited. Through expert interviews with 33 IT executives (76\% chief information officers) from Germany's top 500 companies, this article examines organizational models, strategies, and good practices in IT nearshoring and offshoring. It reveals a shift from traditional captive centers toward fully integrated global teams, enabling high-value task delivery and reflecting increased workforce maturity. Companies are expanding their operations driven by talent needs rather than cost savings, with success factors including employee integration and robust on-site management. This study contributes to theory and practice by providing a framework for understanding organizational models in global IT delivery and offering actionable insights for executives, emphasizing workforce integration over geographical separation.}, subject = {Offshoring}, language = {en} } @article{HauslerHolznerEhrnspergeretal., author = {Hausler, Peter and Holzner, Lukas and Ehrnsperger, Matthias and Bierl, Rudolf}, title = {Evaluation of the creep strength of samples produced by fused deposition modeling}, series = {Open Engineering}, volume = {14}, journal = {Open Engineering}, number = {1}, publisher = {de Gruyter}, doi = {10.1515/eng-2024-0084}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:898-opus4-79760}, pages = {10}, abstract = {Data sheets for 3D printing materials typically include softening temperature, impact strength, tensile strength, and stiffness. However, creep strength, an important parameter for components used over an extended period, is usually not included. Nevertheless, this parameter is of significant importance for components that are used over an extended period of time.This study compares the long-term creep behavior of a selection of materials that are commonly used in fused deposition modeling 3D printing. The materials under investigation are acrylonitrile butadiene styrene, acrylonitrile styrene acrylate, polylactic acid, and polycarbonate. In addition, the influence of fiber reinforcements on these materials is also examined. A simple, reproducible test procedure is proposed for users to determine and compare creep resistance of materials. This enables developers to select materials suitable for their own requirements on creep resistance and allows 3D-printing users to compare different materials. Results suggest that fiber reinforcement generally improves creep stability in 3D-printing materials, with GreenTEC Pro Carbon and add:north PC Blend HT LCF showing the most promise in this study.}, language = {en} }