@article{36815, abstract = {{Iso-octane is frequently used as a surrogate fuel or as a component in primary reference fuel blends when low-temperature combustion strategies in engines are investigated. To develop control strategies for these engines, the reaction kinetics of iso-octane must be known starting from the low temperatures and intermediate pressures before ignition to the high temperatures and pressures of combustion. This work adds new experimental data sets to the validation data for reaction mechanism development by investigating the oxidation of iso-octane in stoichiometric mixtures in a flow reactor at pressures of p = 1, 10, and 20 bar and 473K ≤ T ≤ 973 K. The experimental data are compared to simulations with recent reaction mechanisms [Atef et al., Combustion and Flame 178, (2017), Bagheri et al., Combustion and Flame 212, (2020), Cai et al., Proceedings of the Combustion Institute 37, (2018), Fang et al., Combustion and Flame 214, (2020)]. The comparison between experimental and simulated mole fractions as function of temperature show reasonable agreement for all investigated pressures. In particular, the experimentally observed onset of low-temperature reactivity above a certain pressure, the shift of the negative temperature coefficient (NTC) regime with increasing pressure to higher temperatures, and the acceleration of the high-temperature chemistry are captured well in the simulations. Deviations between experimental and simulated results are discussed in detail for the reactivity of iso-octane and some key intermediates such as 2,2,4,4-tetramethyl-tetrahydrofuran, iso-butene and acetone at low temperatures.}}, author = {{Shaqiri, S. and Kaczmarek, D. and vom Lehn, F. and Beeckmann, J. and Pitsch, H. and Kasper, Tina}}, issn = {{2296-598X}}, journal = {{Frontiers in Energy Research}}, keywords = {{Economics and Econometrics, Energy Engineering and Power Technology, Fuel Technology, Renewable Energy, Sustainability and the Environment}}, publisher = {{Frontiers Media SA}}, title = {{{Experimental Investigation of the Pressure Dependence of Iso-Octane Combustion}}}, doi = {{10.3389/fenrg.2022.859112}}, volume = {{10}}, year = {{2022}}, } @article{36817, author = {{Hoener, Martin and Kasper, Tina}}, issn = {{0010-2180}}, journal = {{Combustion and Flame}}, keywords = {{General Physics and Astronomy, Energy Engineering and Power Technology, Fuel Technology, General Chemical Engineering, General Chemistry}}, publisher = {{Elsevier BV}}, title = {{{Nitrous acid in high-pressure oxidation of CH4 doped with nitric oxide: Challenges in the isomer-selective detection and quantification of an elusive intermediate}}}, doi = {{10.1016/j.combustflame.2022.112096}}, volume = {{243}}, year = {{2022}}, } @article{36814, author = {{Kaczmarek, D. and Bierkandt, T. and Rudolph, C. and Grimm, S. and Shaqiri, S. and Höner, M. and Gaiser, N. and Atakan, B. and Köhler, M. and Hemberger, P. and Kasper, Tina}}, issn = {{2666-352X}}, journal = {{Applications in Energy and Combustion Science}}, keywords = {{Fuel Technology, Energy (miscellaneous), Chemical Engineering (miscellaneous)}}, publisher = {{Elsevier BV}}, title = {{{Activation effect of ozone and DME on the partial oxidation of natural gas surrogates and validation of pressure-dependent ozone decomposition}}}, doi = {{10.1016/j.jaecs.2022.100107}}, year = {{2022}}, } @article{37138, abstract = {{AbstractAssuming that potential biases of Artificial Intelligence (AI)-based systems can be identified and controlled for (e.g., by providing high quality training data), employing such systems to augment human resource (HR)-decision makers in candidate selection provides an opportunity to make selection processes more objective. However, as the final hiring decision is likely to remain with humans, prevalent human biases could still cause discrimination. This work investigates the impact of an AI-based system’s candidate recommendations on humans’ hiring decisions and how this relation could be moderated by an Explainable AI (XAI) approach. We used a self-developed platform and conducted an online experiment with 194 participants. Our quantitative and qualitative findings suggest that the recommendations of an AI-based system can reduce discrimination against older and female candidates but appear to cause fewer selections of foreign-race candidates. Contrary to our expectations, the same XAI approach moderated these effects differently depending on the context.}}, author = {{Hofeditz, Lennart and Clausen, Sünje and Rieß, Alexander and Mirbabaie, Milad and Stieglitz, Stefan}}, issn = {{1019-6781}}, journal = {{Electronic Markets (ELMA)}}, keywords = {{Management of Technology and Innovation, Marketing, Computer Science Applications, Economics and Econometrics, Business and International Management}}, publisher = {{Springer Science and Business Media LLC}}, title = {{{Applying XAI to an AI-based system for candidate management to mitigate bias and discrimination in hiring}}}, doi = {{10.1007/s12525-022-00600-9}}, year = {{2022}}, } @inbook{37902, author = {{Janicki, Nicole}}, booktitle = {{Technik: Verstehen wir, was wir nutzen!? - Tagungsband zur 23. Jahrestagung der Deutschen Gesellschaft für Technische Bildung in Mannheim vom 24.-25. September 2021. }}, editor = {{Binder, Martin and Wiesmüller, Christian and Finkbeiner, Timo}}, keywords = {{technology education, teacher professionalisation, Computational Thinking, digitalization, learning robots}}, location = {{Mannheim}}, pages = {{266--286}}, title = {{{Entwicklung und Evaluation eines Fortbildungskonzepts im Kontext der technischen Bildung an Grundschulen am Beispiel von Lernrobotern}}}, year = {{2022}}, } @article{40554, author = {{Rodríguez-Gómez, Alberto and Lepre, Enrico and Dorado, Fernando and Sanchez-Silva, Luz and Lopez Salas, Nieves and de la Osa, Ana Raquel}}, issn = {{2468-6069}}, journal = {{Materials Today Energy}}, keywords = {{Energy Engineering and Power Technology, Fuel Technology, Nuclear Energy and Engineering, Materials Science (miscellaneous), Renewable Energy, Sustainability and the Environment}}, publisher = {{Elsevier BV}}, title = {{{Efficient ethanol electro-reforming on bimetallic anodes supported on adenine-based noble carbons: hydrogen production and value-added chemicals}}}, doi = {{10.1016/j.mtener.2022.101231}}, volume = {{32}}, year = {{2022}}, } @inproceedings{35271, author = {{Weiß, Deborah and Schramm, Britta}}, booktitle = {{Procedia Structural Integrity}}, issn = {{2452-3216}}, keywords = {{General Engineering, Energy Engineering and Power Technology}}, location = {{Madeira}}, pages = {{879--885}}, publisher = {{Elsevier BV}}, title = {{{Fracture mechanical investigation of preformed metal sheets using a novel CC-specimen}}}, doi = {{10.1016/j.prostr.2022.12.111}}, volume = {{42}}, year = {{2022}}, } @article{41906, abstract = {{Abstract Background Due to the steadily increasing life expectancy of the population, the need for medical aids to maintain the previous quality of life is growing. The basis for independent mobility is a functional locomotor system. The hip joint can be so badly damaged by everyday wear or accelerated by illness that reconstruction by means of endoprostheses is necessary. Results In order to ensure a high quality of life for the patient after this procedure as well as a long service life of the prosthesis, a high-quality design is required, so that many different aspects have to be taken into account when developing prostheses. Long-term medical studies show that the service life and operational safety of a hip prosthesis by best possible adaptation of the stiffness to that of the bone can be increased. The use of additive manufacturing processes enables to specifically change the stiffness of implant structures. Conclusions Reduced implant stiffness leads to an increase in stress in the surrounding bone and thus to a reduction in bone resorption. Numerical methods are used to demonstrate this fact in the hip implant developed. The safety of use is nevertheless ensured by evaluating and taking into account the stresses that occur for critical load cases. These results are a promising basis to enable longer service life of prostheses in the future. }}, author = {{Risse, Lena and Woodcock, Steven Clifford and Brüggemann, Jan-Peter and Kullmer, Gunter and Richard, Hans Albert}}, issn = {{1475-925X}}, journal = {{BioMedical Engineering OnLine}}, keywords = {{Radiology, Nuclear Medicine and imaging, Biomedical Engineering, General Medicine, Biomaterials, Radiological and Ultrasound Technology}}, number = {{1}}, publisher = {{Springer Science and Business Media LLC}}, title = {{{Stiffness optimization and reliable design of a hip implant by using the potential of additive manufacturing processes}}}, doi = {{10.1186/s12938-022-00990-z}}, volume = {{21}}, year = {{2022}}, } @article{32492, author = {{Lau, S. and Gonchikzhapov, M. and Paletsky, A. and Shmakov, A. and Korobeinichev, O. and Kasper, Tina and Atakan, B.}}, issn = {{0010-2180}}, journal = {{Combustion and Flame}}, keywords = {{General Physics and Astronomy, Energy Engineering and Power Technology, Fuel Technology, General Chemical Engineering, General Chemistry}}, publisher = {{Elsevier BV}}, title = {{{Aluminum Diethylphosphinate as a Flame Retardant for Polyethylene: Investigation of the Pyrolysis and Combustion Behavior of PE/AlPi-Mixtures}}}, doi = {{10.1016/j.combustflame.2022.112006}}, volume = {{240}}, year = {{2022}}, } @article{29376, abstract = {{The electrochemical properties of carbonaceous materials produced by hydrothermal carbonization, referred to as hydrochar, can be substantially improved by post-carbonization via pyrolysis. Although these materials have been widely studied for a variety of applications, the mechanisms underlying the pyrolysis are yet poorly understood. This study provides a comprehensive temperature-resolved characterization of the chemical composition, morphology and crystallinity of sucrose-derived hydrochar during pyrolysis. Thermogravimetric analysis, differential scanning calorimetry, and elemental analysis have shown that the dry hydrochar loses about 41% of its dry mass due to the exothermic disintegration of oxygen-containing groups until the carbonization is completed at about 850 °C with a total carbon yield of 93%. The carbonization and aromatization of the initially furanic and keto-aliphatic structure were analyzed by 13C solid-state nuclear magnetic resonance spectroscopy, X-ray photoelectron spectroscopy, and Fourier transform infrared spectroscopy. The transition from an amorphous to a nanocrystalline graphitic structure was analyzed using X-ray diffraction and Raman spectroscopy. The pore formation mechanism was examined by helium ion microscopy, transmission electron microscopy, and nitrogen adsorption measurements. The results indicate the formation of oxygen-rich nanoclusters up to 700 °C, which decompose up to 750 °C leaving behind equally sized pores, resulting in a surface area of up to 480 m2/g.}}, author = {{Wortmann, Martin and Keil, Waldemar and Brockhagen, Bennet and Biedinger, Jan and Westphal, Michael and Weinberger, Christian and Diestelhorst, Elise and Hachmann, Wiebke and Zhao, Yanjing and Tiemann, Michael and Reiss, Günter and Hüsgen, Bruno and Schmidt, Claudia and Sattler, Klaus and Frese, Natalie}}, issn = {{0165-2370}}, journal = {{Journal of Analytical and Applied Pyrolysis}}, keywords = {{Analytical Chemistry, Fuel Technology}}, publisher = {{Elsevier BV}}, title = {{{Pyrolysis of sucrose-derived hydrochar}}}, doi = {{10.1016/j.jaap.2021.105404}}, volume = {{161}}, year = {{2022}}, } @article{43433, abstract = {{Ziel dieser Studie ist es den digitalen moodlegestützten asynchronen Sprachkurs Fachspezifisches Chinesisch für das „Maschinenbau in China Programm“ (mb-cn) der Fakultät für Maschinenbau der Universität Paderborn zu evaluieren, um Handlungsempfehlungen für zukünftig ähnlich aufgebaute Projekte zu entwickeln. Dazu wurden im Sommersemester 2021 sechs leitfadengestützte Interviews geführt. Die Interviews wurden anschließend mithilfe von deduktiv ermittelten Kategorien, die sich aus dem Technology Acceptance Model 2 (TAM2) nach Venkatesh und Davis (2000) ergaben, nach Mayring (2015) analysiert, um abschließend die Forschungsfrage zu beantworten: „Wie bewerten mb-cn Ingenieurstudierende die wahrgenommene Nützlichkeit der digitalen Sprachlernangebote des Kurses Fachspezifisches Chinesisch?“.}}, author = {{Hambach, Dennis}}, journal = {{ die hochschullehre. Interdisziplinäre Zeitschrift für Hochschule und Lehre}}, keywords = {{Technology Acceptance Model, Fachspezifische Chinesischsprachkurse, digitale Lehre, Moodle, Evaluation}}, number = {{8}}, pages = {{1--15}}, publisher = {{wbv Publikation}}, title = {{{Evaluation eines digitalen Fachspezifischen Chinesischsprachkurses für Studierende des Ingenieurwesens}}}, doi = {{10.3278/HSL2249W}}, year = {{2022}}, } @article{34224, abstract = {{Crack growth in structures depends on the cyclic loads applied on it, such as mechanical, thermal and contact, as well as residual stresses, etc. To provide an accurate simulation of crack growth in structures, it is of high importance to integrate all kinds of loading situations in the simulations. Adapcrack3D is a simulation program that can accurately predict the propagation of cracks in real structures. However, until now, this three-dimensional program has only considered mechanical loads and static thermal loads. Therefore, the features of Adapcrack3D have been extended by including contact loading in crack growth simulations. The numerical simulation of crack propagation with Adapcrack3D is generally carried out using FE models of structures provided by the user. For simulating models with contact loading situations, Adapcrack3D has been updated to work with FE models containing multiple parts and necessary features such as coupling and surface interactions. Because Adapcrack3D uses the submodel technique for fracture mechanical evaluations, the architecture of the submodel is also modified to simulate models with contact definitions between the crack surfaces. This paper discusses the newly implemented attribute of the program with the help of illustrative examples. The results confirm that the contact simulation in Adapcrack3D is a major step in improving the functionality of the program.}}, author = {{Joy, Tintu David and Weiß, Deborah and Schramm, Britta and Kullmer, Gunter}}, issn = {{2076-3417}}, journal = {{Applied Sciences}}, keywords = {{Fluid Flow and Transfer Processes, Computer Science Applications, Process Chemistry and Technology, General Engineering, Instrumentation, General Materials Science}}, number = {{15}}, publisher = {{MDPI AG}}, title = {{{Further Development of 3D Crack Growth Simulation Program to Include Contact Loading Situations}}}, doi = {{10.3390/app12157557}}, volume = {{12}}, year = {{2022}}, } @inproceedings{30726, author = {{Weiß, Deborah and Schramm, Britta and Kullmer, Gunter}}, booktitle = {{Procedia Structural Integrity}}, issn = {{2452-3216}}, keywords = {{General Engineering, Energy Engineering and Power Technology}}, location = {{online}}, pages = {{139--147}}, publisher = {{Elsevier BV}}, title = {{{Influence of plane mixed-mode loading on the kinking angle of clinchable metal sheets}}}, doi = {{10.1016/j.prostr.2022.03.082}}, volume = {{39}}, year = {{2022}}, } @article{29208, abstract = {{The parameters required to calculate the energy efficiency of household refrigerating appliances (i.e. refrigerators, freezers and their combinations) are determined by standard measurements. According to regulations, these measurements are carried out when the appliances are new. It is known from previous studies that various technical aging mechanisms can increase electrical energy consumption by up to 36 % over a product lifespan of 18 years. In order to determine the time dependence of the energy consumption of household refrigerating appliances, repeated measurements are carried out in this work. Eleven new appliances are examined under standard measurement conditions. After just two years of operation, an additional energy consumption of up to 11 % is determined. Furthermore, 21 older appliances that had previously been measured in new condition are tested again after up to 21 years of operation. For these older appliances, an average increase of energy consumption of 28 % is found. For individual appliances, the maximum increase is 36 %. An aging model is developed on the basis of these measurement results, which may help to predict the aging-related increase of energy consumption of household refrigerating appliances. This model shows an average increase in energy consumption of 27 % for an appliance age of 16 years. Supplemental performance tests of eight compressors do not show any significant aging effects related to these devices after two years of operation. Furthermore, measurements of the thermal conductivity of aged polyurethane foam test samples are carried out and an increase of its thermal conductivity of 26 % over a period of about three years is determined.}}, author = {{Paul, Andreas and Baumhögger, Elmar and Elsner, Andreas and Reineke, Michael and Hueppe, Christian and Stamminger, Rainer and Hoelscher, Heike and Wagner, Hendrik and Gries, Ulrich and Becker, Wolfgang and Vrabec, Jadran}}, issn = {{1359-4311}}, journal = {{Applied Thermal Engineering}}, keywords = {{Industrial and Manufacturing Engineering, Energy Engineering and Power Technology}}, publisher = {{Elsevier BV}}, title = {{{Impact of aging on the energy efficiency of household refrigerating appliances}}}, doi = {{10.1016/j.applthermaleng.2021.117992}}, volume = {{205}}, year = {{2022}}, } @article{31808, author = {{Khider Abbas Abbas, Wameedh and Baumhögger, Elmar and Vrabec, Jadran}}, issn = {{2590-1745}}, journal = {{Energy Conversion and Management: X}}, keywords = {{Energy Engineering and Power Technology, Fuel Technology, Nuclear Energy and Engineering, Renewable Energy, Sustainability and the Environment}}, publisher = {{Elsevier BV}}, title = {{{Experimental investigation of organic Rankine cycle performance using alkanes or hexamethyldisiloxane as a working fluid}}}, doi = {{10.1016/j.ecmx.2022.100244}}, year = {{2022}}, } @article{44238, abstract = {{In numerous turbomachinery applications, e.g., in aero-engines with regenerators for improving specific fuel consumption (SFC), heat exchangers with low-pressure loss are required. Pil low-plate heat exchangers (PPHE) are a novel exchanger type and promising candidates for high-speed flow applications due to their smooth profiles avoiding blunt obstacles in the flow path. This work deals with the overall system behavior and gas dynamics of pillow-plate channels. A pillow-plate channel was placed in the test section of a blow-down wind tunnel working with dry air, and compressible flow phenomena were investigated utilizing conventional and focusing schlieren optics; furthermore, static and total pressure measurements were performed. The experiments supported the assumption that the system behavior can be described through a Fanno–Rayleigh flow model. Since only wavy walls with smooth profiles were involved, linearized gas dynamics was able to cover important flow features within the channel. The effects of the wavy wall structures on pressure drop and Mach number distribution within the flow path were investigated, and a good qualitative agreement with theoretical and numerical predictions was found. The present analysis demonstrates that pressure losses in pillow-plate heat exchangers are rather low, although their strong turbulent mixing enables high convective heat transfer coefficients.}}, author = {{Sundermeier, Stephan and Passmann, Maximilian and aus der Wiesche, Stefan and Kenig, Eugeny Y.}}, issn = {{2504-186X}}, journal = {{International Journal of Turbomachinery, Propulsion and Power}}, keywords = {{Mechanical Engineering, Energy Engineering and Power Technology, Aerospace Engineering}}, number = {{2}}, publisher = {{MDPI AG}}, title = {{{Flow in Pillow-Plate Channels for High-Speed Turbomachinery Heat Exchangers}}}, doi = {{10.3390/ijtpp7020012}}, volume = {{7}}, year = {{2022}}, } @article{30213, abstract = {{Requirement changes and cascading effects of change propagation are major sources of inefficiencies in product development and increase the risk of project failure. Proactive change management of requirement changes yields the potential to handle such changes efficiently. A systematic approach is required for proactive change management to assess and reduce the risk of a requirement change with appropriate effort in industrial application. Within the paper at hand, a novel method for Proactive Management of Requirement Changes (ProMaRC) is presented. It is developed in close collaboration with industry experts and evaluated based on workshops, pilot users’ feedback, three industrial case studies from the automotive industry and five development projects from research. To limit the application effort, an automated approach for dependency analysis based on the machine learning technique BERT and semi-automated assessment of change likelihood and impact using a modified PageRank algorithm is developed. Applying the method, the risks of requirement changes are assessed systematically and reduced by means of proactive change measures. Evaluation shows high performance of dependency analysis and confirms the applicability and usefulness of the method. This contribution opens up the research space of proactive risk management for requirement changes which is currently almost unexploited. It enables more efficient product development.}}, author = {{Gräßler, Iris and Oleff, Christian and Preuß, Daniel}}, issn = {{2076-3417}}, journal = {{Applied Sciences}}, keywords = {{Fluid Flow and Transfer Processes, Computer Science Applications, Process Chemistry and Technology, General Engineering, Instrumentation, General Materials Science}}, number = {{4}}, publisher = {{MDPI AG}}, title = {{{Proactive Management of Requirement Changes in the Development of Complex Technical Systems}}}, doi = {{10.3390/app12041874}}, volume = {{12}}, year = {{2022}}, } @article{30394, author = {{Hecht, Matthias and Baumgartner, Jörg and Tews, Karina and Çavdar, Serkan and Meschut, Gerson}}, issn = {{2452-3216}}, journal = {{Procedia Structural Integrity}}, keywords = {{General Engineering, Energy Engineering and Power Technology}}, pages = {{251--259}}, publisher = {{Elsevier BV}}, title = {{{Fatigue strength of adhesively butt-bonded hollow cylinders under multiaxial loading with constant and variable amplitudes}}}, doi = {{10.1016/j.prostr.2022.03.026}}, volume = {{38}}, year = {{2022}}, } @article{45016, author = {{Abbas, Wameedh Khider Abbas and Baumhögger, Elmar and Vrabec, Jadran}}, issn = {{2590-1745}}, journal = {{Energy Conversion and Management: X}}, keywords = {{Energy Engineering and Power Technology, Fuel Technology, Nuclear Energy and Engineering, Renewable Energy, Sustainability and the Environment}}, publisher = {{Elsevier BV}}, title = {{{Experimental investigation of organic Rankine cycle performance using alkanes or hexamethyldisiloxane as a working fluid}}}, doi = {{10.1016/j.ecmx.2022.100244}}, volume = {{15}}, year = {{2022}}, } @article{45017, author = {{Abbas, Wameedh Khider Abbas and Baumhögger, Elmar and Vrabec, Jadran}}, issn = {{2590-1745}}, journal = {{Energy Conversion and Management: X}}, keywords = {{Energy Engineering and Power Technology, Fuel Technology, Nuclear Energy and Engineering, Renewable Energy, Sustainability and the Environment}}, publisher = {{Elsevier BV}}, title = {{{Experimental investigation of organic Rankine cycle performance using alkanes or hexamethyldisiloxane as a working fluid}}}, doi = {{10.1016/j.ecmx.2022.100244}}, volume = {{15}}, year = {{2022}}, }