Dokument-ID Dokumenttyp Verfasser/Autoren Herausgeber Haupttitel Abstract Auflage Verlagsort Verlag Erscheinungsjahr Seitenzahl Schriftenreihe Titel Schriftenreihe Bandzahl ISBN Quelle der Hochschulschrift Konferenzname Bemerkung Quelle:Titel Quelle:Jahrgang Quelle:Heftnummer Quelle:Erste Seite Quelle:Letzte Seite URN DOI Zugriffsart Link Abteilungen OPUS4-11092 Arbeitspapier Drescher, Hans Paul, hanspaul.drescher@budi.de Critical review of the 1. Stokes' problem and consequences for mixed turbulent/laminar flow The "1. Stokes' problem", the "suddenly accelerated flat wall", is the oldest application of the Navier-Stokes equations. Stokes' solution of the "problem" does not comply with the mathematical theorem of Cauchy and Kowalewskaya on the "Uniqueness and Existence" of solutions of partial differential equations and violates the physical theorem of minimum entropy production/dissipation of the Thermodynamics of Irreversible Processes. The result includes very high local shear stresses and dissipation rates. That is of special interest for the theory of turbulent and mixed turbulent/laminar flow. A textbook solution of the "1. Stokes Problem" is the Couette flow, which has a constant sheer stress along a linear profile. A consequence is that the Navier-Stokes equations do not describe any S-shaped part of a turbulent profile found in any turbulent Couette experiment. The paper surveys arguments referring to that statement, concerning the history of >150 years. Contrary to this there is always a Navier-Stokes solution near the wall, observed by a linear part of the Couette profile. There a turbulent description (e.g. by the logarithmic law-of-the-wall) fails completely. That is explained by the minimum dissipation requirement together with the Couette feature τ = const. The local co-existence of a turbulent zone and a laminar zone near the wall is stable and observed also at high Reynolds-Numbers. 2024 27 Seiten weltweit OPUS4-11088 misc Hüning, Felix, huening@fh-aachen.de Positionssensorvorrichtung [Offenlegungsschrift] Die Erfindung betrifft eine Positionssensorvorrichtung zur Bestimmung einer Absolutposition eines beweglichen ersten Teils relativ zu einem ortsfesten zweiten Teil mit einem mit dem beweglichen ersten Teil gekoppelter Codekörper, der dazu eingerichtet ist, eine Codespur mit einer Mehrzahl von in Spurrichtung aufeinanderfolgenden Codeelementen zu enthalten zur Bildung eines Codewortes, mit einer magnetischen Detektionseinrichtung zur Detektion der Codespur, wobei die Detektionseinrichtung zum einen an dem Codekörper befestigte und entlang der Spurrichtung in einem solchen Abstand gegenpolig zueinander angeordnete Permanentmagneten aufweist, dass der Abstand mit einer vorgegebenen Länge der jeweiligen Codeelemente übereinstimmt, und zum anderen eine Anzahl von ortsfest und quer zu dem Codekörper versetzt angeordnete Wiegandsensoren aufweist, wobei der Abstand des Wiegandsensors zu einer Erstreckungsebene der Permanentmagneten derart gewählt ist, dass bei Überdeckung des Wiegandsensors durch den Permanentmagneten ein Wiegandpuls in dem Wiegandsensor induziert wird. 2024 Offenlegungsschrift zu DE102022124159A1 2024.03.21 weltweit Patent ansehen bei DPMA Fachbereich Elektrotechnik und Informationstechnik OPUS4-11087 Konferenzveröffentlichung Neumann, Hannah, ; Adam, Mario, ; Backes, Klaus, ; Börner, Martin, ; Clees, Tanja, ; Doetsch, Christian, ; Glaeser, Susanne, ; Herrmann, Ulf, ulf.herrmann@sij.fh-aachen.de; May, Johanna, ; Rosenthal, Florian, rosenthal@fh-aachen.de; Sauer, Dirk Uwe, ; Stadler, Ingo, Development of open educational resources for renewable energy and the energy transition process The dissemination of knowledge about renewable energies is understood as a social task with the highest topicality. The transfer of teaching content on renewable energies into digital open educational resources offers the opportunity to significantly accelerate the implementation of the energy transition. Thus, in the here presented project six German universities create open educational resources for the energy transition. These materials are available to the public on the internet under a free license. So far there has been no publicly accessible, editable media that cover entire learning units about renewable energies extensively and in high technical quality. Thus, in this project, the content that remains up-to-date for a longer period is appropriately prepared in terms of media didactics. The materials enable lecturers to provide students with in-depth training about technologies for the energy transition. In a particular way, the created material is also suitable for making the general public knowledgeable about the energy transition with scientifically based material. Freiburg International Solar Energy Society 2021 6 Seiten ISES SWC 2021 ISES Solar World Congress, virtual conference 25-29 October 2021 10.18086/swc.2021.47.03 https://doi.org/10.18086/swc.2021.47.03 Fachbereich Energietechnik OPUS4-11086 Konferenzveröffentlichung Niederwestberg, Stefan, ; Schneider, Falko, f.schneider@sij.fh-aachen.de; Teixeira Boura, Cristiano José, boura@sij.fh-aachen.de; Herrmann, Ulf, ulf.herrmann@sij.fh-aachen.de Introduction to a direct irradiated transparent tube particle receiver New materials often lead to innovations and advantages in technical applications. This also applies to the particle receiver proposed in this work that deploys high-temperature and scratch resistant transparent ceramics. With this receiver design, particles are heated through direct-contact concentrated solar irradiance while flowing downwards through tubular transparent ceramics from top to bottom. In this paper, the developed particle receiver as well as advantages and disadvantages are described. Investigations on the particle heat-up characteristics from solar irradiance were carried out with DEM simulations which indicate that particle temperatures can reach up to 1200 K. Additionally, a simulation model was set up for investigating the dynamic behavior. A test receiver at laboratory scale has been designed and is currently being built. In upcoming tests, the receiver test rig will be used to validate the simulation results. The design and the measurement equipment is described in this work. Melville, NY AIP conference proceedings / American Institute of Physics 2022 9 Seiten SOLARPACES 2020 978-0-7354-4195-8 26th International Conference on Concentrating Solar Power and Chemical Energy Systems 28 September-2 October 2020 Freiburg, Germany 2445 / 1 10.1063/5.0086735 https://doi.org/10.1063/5.0086735 Fachbereich Energietechnik OPUS4-11085 Konferenzveröffentlichung Caminos, Ricardo Alexander Chico, ; Schmitz, Pascal, schmitz@sij.fh-aachen.de; Atti, Vikrama, ; Mahdi, Zahra, ; Teixeira Boura, Cristiano José, boura@sij.fh-aachen.de; Sattler, Johannes Christoph, sattler@sij.fh-aachen.de; Herrmann, Ulf, ulf.herrmann@sij.fh-aachen.de; Hilger, Patrick, ; Dieckmann, Simon, Development of a micro heliostat and optical qualification assessment with a 3D laser scanning method The Solar-Institut Jülich (SIJ) and the companies Hilger GmbH and Heliokon GmbH from Germany have developed a small-scale cost-effective heliostat, called "micro heliostat". Micro heliostats can be deployed in small-scale concentrated solar power (CSP) plants to concentrate the sun's radiation for electricity generation, space or domestic water heating or industrial process heat. In contrast to conventional heliostats, the special feature of a micro heliostat is that it consists of dozens of parallel-moving, interconnected, rotatable mirror facets. The mirror facets array is fixed inside a box-shaped module and is protected from weathering and wind forces by a transparent glass cover. The choice of the building materials for the box, tracking mechanism and mirrors is largely dependent on the selected production process and the intended application of the micro heliostat. Special attention was paid to the material of the tracking mechanism as this has a direct influence on the accuracy of the micro heliostat. The choice of materials for the mirror support structure and the tracking mechanism is made in favor of plastic molded parts. A qualification assessment method has been developed by the SIJ in which a 3D laser scanner is used in combination with a coordinate measuring machine (CMM). For the validation of this assessment method, a single mirror facet was scanned and the slope deviation was computed. Melville, NY AIP conference proceedings / American Institute of Physics 2022 8 Seiten SOLARPACES 2020 978-0-7354-4195-8 26th International Conference on Concentrating Solar Power and Chemical Energy Systems 28 September-2 October 2020 Freiburg, Germany 2445 / 1 10.1063/5.0086262 https://doi.org/10.1063/5.0086262 Fachbereich Energietechnik OPUS4-11084 Konferenzveröffentlichung Zahra, Mahdi, ; Phani Srujan, Merige, ; Caminos, Ricardo Alexander Chico, ; Schmitz, Pascal, schmitz@sij.fh-aachen.de; Herrmann, Ulf, ulf.herrmann@sij.fh-aachen.de; Teixeira Boura, Cristiano José, boura@sij.fh-aachen.de; Schmitz, Mark, ; Gielen, Hans, ; Gedle, Yibekal, ; Dersch, Jürgen, Modeling the thermal behavior of solar salt in electrical resistance heaters for the application in PV-CSP hybrid power plants Concentrated Solar Power (CSP) systems are able to store energy cost-effectively in their integrated thermal energy storage (TES). By intelligently combining Photovoltaics (PV) systems with CSP, a further cost reduction of solar power plants is expected, as well as an increase in dispatchability and flexibility of power generation. PV-powered Resistance Heaters (RH) can be deployed to raise the temperature of the molten salt hot storage from 385 °C up to 565 °C in a Parabolic Trough Collector (PTC) plant. To avoid freezing and decomposition of molten salt, the temperature distribution in the electrical resistance heater is investigated in the present study. For this purpose, a RH has been modeled and CFD simulations have been performed. The simulation results show that the hottest regions occur on the electric rod surface behind the last baffle. A technical optimization was performed by adjusting three parameters: Shell-baffle clearance, electric rod-baffle clearance and number of baffles. After the technical optimization was carried out, the temperature difference between the maximum temperature and the average outlet temperature of the salt is within the acceptable limits, thus critical salt decomposition has been avoided. Additionally, the CFD simulations results were analyzed and compared with results obtained with a one-dimensional model in Modelica. Melville, NY AIP conference proceedings / American Institute of Physics 2022 9 Seiten SOLARPACES 2020 978-0-7354-4195-8 26th International Conference on Concentrating Solar Power and Chemical Energy Systems 28 September-2 October 2020 Freiburg, Germany 2445 / 1 10.1063/5.0086268 https://doi.org/10.1063/5.0086268 Fachbereich Energietechnik OPUS4-11083 Wissenschaftlicher Artikel Zhen, Manghao, ; Liang, Yunpei, ; Staat, Manfred, m.staat@fh-aachen.de; Li, Quanqui, ; Li, Jianbo, Discontinuous fracture behaviors and constitutive model of sandstone specimens containing non-parallel prefabricated fissures under uniaxial compression The deformation and damage laws of non-homogeneous irregular structural planes in rocks are the basis for studying the stability of rock engineering. To investigate the damage characteristics of rock containing non-parallel fissures, uniaxial compression tests and numerical simulations were conducted on sandstone specimens containing three non-parallel fissures inclined at 0°, 45° and 90° in this study. The characteristics of crack initiation and crack evolution of fissures with different inclinations were analyzed. A constitutive model for the discontinuous fractures of fissured sandstone was proposed. The results show that the fracture behaviors of fissured sandstone specimens are discontinuous. The stress-strain curves are non-smooth and can be divided into nonlinear crack closure stage, linear elastic stage, plastic stage and brittle failure stage, of which the plastic stage contains discontinuous stress drops. During the uniaxial compression test, the middle or ends of 0° fissures were the first to crack compared to 45° and 90° fissures. The end with small distance between 0° and 45° fissures cracked first, and the end with large distance cracked later. After the final failure, 0° fissures in all specimens were fractured, while 45° and 90° fissures were not necessarily fractured. Numerical simulation results show that the concentration of compressive stress at the tips of 0°, 45° and 90° fissures, as well as the concentration of tensile stress on both sides, decreased with the increase of the inclination angle. A constitutive model for the discontinuous fractures of fissured sandstone specimens was derived by combining the logistic model and damage mechanic theory. This model can well describe the discontinuous drops of stress and agrees well with the whole processes of the stress-strain curves of the fissured sandstone specimens. Amsterdam Elsevier 2024 13 Seiten Theoretical and Applied Fracture Mechanics 131 Art. No. 104373 10.1016/j.tafmec.2024.104373 campus https://doi.org/10.1016/j.tafmec.2024.104373 Fachbereich Medizintechnik und Technomathematik OPUS4-11082 Wissenschaftlicher Artikel Engelmann, Ulrich M., engelmann@fh-aachen.de; Simsek, Beril, ; Shalaby, Ahmed, ; Krause, Hans-Joachim, h.krause@fh-aachen.de Key contributors to signal generation in frequency mixing magnetic detection (FMMD): an in silico study Frequency mixing magnetic detection (FMMD) is a sensitive and selective technique to detect magnetic nanoparticles (MNPs) serving as probes for binding biological targets. Its principle relies on the nonlinear magnetic relaxation dynamics of a particle ensemble interacting with a dual frequency external magnetic field. In order to increase its sensitivity, lower its limit of detection and overall improve its applicability in biosensing, matching combinations of external field parameters and internal particle properties are being sought to advance FMMD. In this study, we systematically probe the aforementioned interaction with coupled Néel-Brownian dynamic relaxation simulations to examine how key MNP properties as well as applied field parameters affect the frequency mixing signal generation. It is found that the core size of MNPs dominates their nonlinear magnetic response, with the strongest contributions from the largest particles. The drive field amplitude dominates the shape of the field-dependent response, whereas effective anisotropy and hydrodynamic size of the particles only weakly influence the signal generation in FMMD. For tailoring the MNP properties and parameters of the setup towards optimal FMMD signal generation, our findings suggest choosing large particles of core sizes dc > 25 nm nm with narrow size distributions (σ < 0.1) to minimize the required drive field amplitude. This allows potential improvements of FMMD as a stand-alone application, as well as advances in magnetic particle imaging, hyperthermia and magnetic immunoassays. Basel MDPI 2024 Artikel 1945 Sensors 24 This article belongs to the Special Issue "Advances in Magnetic Sensors and Their Applications" 6 10.3390/s24061945 weltweit https://doi.org/10.3390/s24061945 Fachbereich Medizintechnik und Technomathematik OPUS4-11081 Buch (Monographie) Elsaesser, Evelyn, ; Klebinggat, Michael, ; Kuhn, Wilfried, ; Michielsens, Constant, ; Pauels, Willibert, ; Popkes, Enno E., ; Schneider, Elke, ; Laack, Walter van, Dr.vanLaack@web.de; Warven, Rinus van, Laack, Walter van Schnittstelle Tod - Ist die Menschheit zu retten ohne Vertrauen auf ein Danach Aachen van Laack Buchverlag 2024 156 Seiten 978-3-936624-58-8 8. Tagungsband zum NTE-Seminar in Aachen am, 11.11.2023 https://www.vanlaack-buch.de/buecher-d/schnittstelle-tod-ist-die-menschheit-zu-retten-ohne-vertrauen-auf-ein-danach/ Fachbereich Medizintechnik und Technomathematik OPUS4-11080 Konferenzveröffentlichung Mahdi, Zahra, ; Dersch, Jürgen, ; Schmitz, Pascal, schmitz@sij.fh-aachen.de; Dieckmann, Simon, ; Caminos, Ricardo Alexander Chico, ; Teixeira Boura, Cristiano José, boura@sij.fh-aachen.de; Herrmann, Ulf, ulf.herrmann@sij.fh-aachen.de; Schwager, Christian, ; Schmitz, Mark, ; Gielen, Hans, ; Gedle, Yibekal, ; Büscher, Rauno, Technical assessment of Brayton cycle heat pumps for the integration in hybrid PV-CSP power plants The hybridization of Concentrated Solar Power (CSP) and Photovoltaics (PV) systems is a promising approach to reduce costs of solar power plants, while increasing dispatchability and flexibility of power generation. High temperature heat pumps (HT HP) can be utilized to boost the salt temperature in the thermal energy storage (TES) of a Parabolic Trough Collector (PTC) system from 385 °C up to 565 °C. A PV field can supply the power for the HT HP, thus effectively storing the PV power as thermal energy. Besides cost-efficiently storing energy from the PV field, the power block efficiency of the overall system is improved due to the higher steam parameters. This paper presents a technical assessment of Brayton cycle heat pumps to be integrated in hybrid PV-CSP power plants. As a first step, a theoretical analysis was carried out to find the most suitable working fluid. The analysis included the fluids Air, Argon (Ar), Nitrogen (N2) and Carbon dioxide (CO2). N2 has been chosen as the optimal working fluid for the system. After the selection of the ideal working medium, different concepts for the arrangement of a HT HP in a PV-CSP hybrid power plant were developed and simulated in EBSILON®Professional. The concepts were evaluated technically by comparing the number of components required, pressure losses and coefficient of performance (COP). Melville, NY AIP conference proceedings / American Institute of Physics 2022 11 Seiten SOLARPACES 2020 978-0-7354-4195-8 26th International Conference on Concentrating Solar Power and Chemical Energy Systems 28 September-2 October 2020 Freiburg, Germany 2445 / 1 10.1063/5.0086269 https://doi.org/10.1063/5.0086269 Fachbereich Energietechnik OPUS4-11079 Konferenzveröffentlichung Gedle, Yibekal, ; Schmitz, Mark, ; Gielen, Hans, ; Schmitz, Pascal, schmitz@sij.fh-aachen.de; Herrmann, Ulf, ulf.herrmann@sij.fh-aachen.de; Teixeira Boura, Cristiano José, boura@sij.fh-aachen.de; Mahdi, Zahra, mahdi@sij.fh-aachen.de; Caminos, Ricardo Alexander Chico, ; Dersch, Jürgen, Analysis of an integrated CSP-PV hybrid power plant In the past, CSP and PV have been seen as competing technologies. Despite massive reductions in the electricity generation costs of CSP plants, PV power generation is - at least during sunshine hours - significantly cheaper. If electricity is required not only during the daytime, but around the clock, CSP with its inherent thermal energy storage gets an advantage in terms of LEC. There are a few examples of projects in which CSP plants and PV plants have been co-located, meaning that they feed into the same grid connection point and ideally optimize their operation strategy to yield an overall benefit. In the past eight years, TSK Flagsol has developed a plant concept, which merges both solar technologies into one highly Integrated CSP-PV-Hybrid (ICPH) power plant. Here, unlike in simply co-located concepts, as analyzed e.g. in [1] - [4], excess PV power that would have to be dumped is used in electric molten salt heaters to increase the storage temperature, improving storage and conversion efficiency. The authors demonstrate the electricity cost sensitivity to subsystem sizing for various market scenarios, and compare the resulting optimized ICPH plants with co-located hybrid plants. Independent of the three feed-in tariffs that have been assumed, the ICPH plant shows an electricity cost advantage of almost 20% while maintaining a high degree of flexibility in power dispatch as it is characteristic for CSP power plants. As all components of such an innovative concept are well proven, the system is ready for commercial market implementation. A first project is already contracted and in early engineering execution. Melville, NY AIP conference proceedings / American Institute of Physics 2022 9 Seiten SolarPACES 2020 978-0-7354-4195-8 26th International Conference on Concentrating Solar Power and Chemical Energy Systems 28 September-2 October 2020 Freiburg, Germany 2445 / 1 10.1063/5.0086236 https://doi.org/10.1063/5.0086236 Fachbereich Energietechnik OPUS4-11078 Wissenschaftlicher Artikel Schwager, Christian, ; Flesch, Robert, ; Schwarzbözl, Peter, ; Herrmann, Ulf, ulf.herrmann@sij.fh-aachen.de; Teixeira Boura, Cristiano José, boura@sij.fh-aachen.de Advanced two phase flow model for transient molten salt receiver system simulation In order to realistically predict and optimize the actual performance of a concentrating solar power (CSP) plant sophisticated simulation models and methods are required. This paper presents a detailed dynamic simulation model for a Molten Salt Solar Tower (MST) system, which is capable of simulating transient operation including detailed startup and shutdown procedures including drainage and refill. For appropriate representation of the transient behavior of the receiver as well as replication of local bulk and surface temperatures a discretized receiver model based on a novel homogeneous two-phase (2P) flow modelling approach is implemented in Modelica Dymola®. This allows for reasonable representation of the very different hydraulic and thermal properties of molten salt versus air as well as the transition between both. This dynamic 2P receiver model is embedded in a comprehensive one-dimensional model of a commercial scale MST system and coupled with a transient receiver flux density distribution from raytracing based heliostat field simulation. This enables for detailed process prediction with reasonable computational effort, while providing data such as local salt film and wall temperatures, realistic control behavior as well as net performance of the overall system. Besides a model description, this paper presents some results of a validation as well as the simulation of a complete startup procedure. Finally, a study on numerical simulation performance and grid dependencies is presented and discussed. Amsterdam Elsevier 2022 13 Solar Energy 232 362 375 10.1016/j.solener.2021.12.065 https://doi.org/10.1016/j.solener.2021.12.065 Fachbereich Energietechnik OPUS4-11077 Konferenzveröffentlichung Schwager, Christian, ; Angele, Florian, ; Schwarzbözl, Peter, ; Teixeira Boura, Cristiano José, Boura@sij.fh-aachen.de; Herrmann, Ulf, ulf.herrmann@sij.fh-aachen.de Model predictive assistance for operational decision making in molten salt receiver systems Despite the challenges of pioneering molten salt towers (MST), it remains the leading technology in central receiver power plants today, thanks to cost effective storage integration and high cost reduction potential. The limited controllability in volatile solar conditions can cause significant losses, which are difficult to estimate without comprehensive modeling [1]. This paper presents a Methodology to generate predictions of the dynamic behavior of the receiver system as part of an operating assistance system (OAS). Based on this, it delivers proposals if and when to drain and refill the receiver during a cloudy period in order maximize the net yield and quantifies the amount of net electricity gained by this. After prior analysis with a detailed dynamic two-phase model of the entire receiver system, two different reduced modeling approaches where developed and implemented in the OAS. A tailored decision algorithm utilizes both models to deliver the desired predictions efficiently and with appropriate accuracy. Melville, NY AIP conference proceedings / American Institute of Physics 2023 8 Seiten SolarPACES: Solar Power & Chemical Energy Systems 978-0-7354-4623-6 27th International Conference on Concentrating Solar Power and Chemical Energy Systems 27 September-1 October 2021 Online 2815 / 1 10.1063/5.0151514 https://doi.org/10.1063/5.0151514 Fachbereich Energietechnik OPUS4-11076 Konferenzveröffentlichung Schulte, Jonas, j.schulte@sij.fh-aachen.de; Schwager, Christian, ; Noureldin, Kareem, ; May, Martin, ; Teixeira Boura, Cristiano José, boura@sij.fh-aachen.de; Herrmann, Ulf, ulf.herrmann@sij.fh-aachen.de Gradient controlled startup procedure of a molten-salt power-to-heat energy storage plant based on dynamic process simulation The integration of high temperature thermal energy storages into existing conventional power plants can help to reduce the CO2 emissions of those plants and lead to lower capital expenditures for building energy storage systems, due to the use of synergy effects [1]. One possibility to implement that, is a molten salt storage system with a powerful power-to-heat unit. This paper presents two possible control concepts for the startup of the charging system of such a facility. The procedures are implemented in a detailed dynamic process model. The performance and safety regarding the film temperatures at heat transmitting surfaces are investigated in the process simulations. To improve the accuracy in predicting the film temperatures, CFD simulations of the electrical heater are carried out and the results are merged with the dynamic model. The results show that both investigated control concepts are safe regarding the temperature limits. The gradient controlled startup performed better than the temperature-controlled startup. Nevertheless, there are several uncertainties that need to be investigated further. Melville, NY AIP conference proceedings / American Institute of Physics 2023 9 Seiten SolarPACES: Solar Power & Chemical Energy Systems 978-0-7354-4623-6 27th International Conference on Concentrating Solar Power and Chemical Energy Systems 27 September-1 October 2021 Online 2815 / 1 10.1063/5.0148741 https://doi.org/10.1063/5.0148741 Fachbereich Energietechnik OPUS4-11069 Konferenzveröffentlichung Lahrs, Lennart, ; Krisam, Pierre, ; Herrmann, Ulf, ulf.herrmann@sij.fh-aachen.de Envisioning a collaborative energy system planning platform for the energy transition at the district level Residential and commercial buildings account for more than one-third of global energy-related greenhouse gas emissions. Integrated multi-energy systems at the district level are a promising way to reduce greenhouse gas emissions by exploiting economies of scale and synergies between energy sources. Planning district energy systems comes with many challenges in an ever-changing environment. Computational modelling established itself as the state-of-the-art method for district energy system planning. Unfortunately, it is still cumbersome to combine standalone models to generate insights that surpass their original purpose. Ideally, planning processes could be solved by using modular tools that easily incorporate the variety of competing and complementing computational models. Our contribution is a vision for a collaborative development and application platform for multi-energy system planning tools at the district level. We present challenges of district energy system planning identified in the literature and evaluate whether this platform can help to overcome these challenges. Further, we propose a toolkit that represents the core technical elements of the platform. Lastly, we discuss community management and its relevance for the success of projects with collaboration and knowledge sharing at their core. Procedings of ECOS 2023 2023 7 The 36th International Conference on Efficiency, Cost, Optimization, Simulation and Environmental Impact of Energy Systems 25-30 JUNE, 2023, Las Palmas de Gran Canaria, Spain 3163 3170 10.52202/069564-0284 https://doi.org/10.52202/069564-0284 Fachbereich Energietechnik OPUS4-11068 unpublished Grieger, Niklas, grieger@fh-aachen.de; Mehrkanoon, Siamak, ; Bialonski, Stephan, bialonski@fh-aachen.de Preprint: Data-efficient sleep staging with synthetic time series pretraining Analyzing electroencephalographic (EEG) time series can be challenging, especially with deep neural networks, due to the large variability among human subjects and often small datasets. To address these challenges, various strategies, such as self-supervised learning, have been suggested, but they typically rely on extensive empirical datasets. Inspired by recent advances in computer vision, we propose a pretraining task termed "frequency pretraining" to pretrain a neural network for sleep staging by predicting the frequency content of randomly generated synthetic time series. Our experiments demonstrate that our method surpasses fully supervised learning in scenarios with limited data and few subjects, and matches its performance in regimes with many subjects. Furthermore, our results underline the relevance of frequency information for sleep stage scoring, while also demonstrating that deep neural networks utilize information beyond frequencies to enhance sleep staging performance, which is consistent with previous research. We anticipate that our approach will be advantageous across a broad spectrum of applications where EEG data is limited or derived from a small number of subjects, including the domain of brain-computer interfaces. 2024 10 Seiten arXiv weltweit https://arxiv.org/abs/2403.08592 Fachbereich Medizintechnik und Technomathematik OPUS4-11067 Konferenzveröffentlichung Schulte, Jonas, j.schulte@sij.fh-aachen.de; Schwager, Christian, ; Frantz, Cathy, ; Schloms, Felix, ; Teixeira Boura, Cristiano José, boura@sij.fh-aachen.de; Herrmann, Ulf, ulf.herrmann@sij.fh-aachen.de Control concept for a molten salt receiver in star design: Development, optimization and testing with cloud passage scenarios A promising approach to reduce the system costs of molten salt solar receivers is to enable the irradiation of the absorber tubes on both sides. The star design is an innovative receiver design, pursuing this approach. The unconventional design leads to new challenges in controlling the system. This paper presents a control concept for a molten salt receiver system in star design. The control parameters are optimized in a defined test cycle by minimizing a cost function. The control concept is tested in realistic cloud passage scenarios based on real weather data. During these tests, the control system showed no sign of unstable behavior, but to perform sufficiently in every scenario further research and development like integrating Model Predictive Controls (MPCs) need to be done. The presented concept is a starting point to do so. Hannover TIB Open Publishing 2022 9 Seiten SolarPACES conference proceedings 28th International Conference on Concentrating Solar Power and Chemical Energy Systems, 27-30 September, Albuquerque, NM, USA Vol. 1 10.52825/solarpaces.v1i.693 https://doi.org/10.52825/solarpaces.v1i.693 Fachbereich Energietechnik OPUS4-11066 Konferenzveröffentlichung Schwager, Christian, ; Angele, Florian, ; Nouri, Bijan, ; Schwarzbözl, Peter, ; Teixeira Boura, Cristiano José, boura@sij.fh-aachen.de; Herrmann, Ulf, ulf.herrmann@sij.fh-aachen.de Impact of DNI forecast quality on performance prediction for a commercial scale solar tower: Application of nowcasting DNI maps to dynamic solar tower simulation Concerning current efforts to improve operational efficiency and to lower overall costs of concentrating solar power (CSP) plants with prediction-based algorithms, this study investigates the quality and uncertainty of nowcasting data regarding the implications for process predictions. DNI (direct normal irradiation) maps from an all-sky imager-based nowcasting system are applied to a dynamic prediction model coupled with ray tracing. The results underline the need for high-resolution DNI maps in order to predict net yield and receiver outlet temperature realistically. Furthermore, based on a statistical uncertainty analysis, a correlation is developed, which allows for predicting the uncertainty of the net power prediction based on the corresponding DNI forecast uncertainty. However, the study reveals significant prediction errors and the demand for further improvement in the accuracy at which local shadings are forecasted. Hannover TIB Open Publishing 2022 9 Seiten SolarPACES conference proceedings 28th International Conference on Concentrating Solar Power and Chemical Energy Systems, 27-30 September, Albuquerque, NM, USA Vol. 1 10.52825/solarpaces.v1i.675 https://doi.org/10.52825/solarpaces.v1i.675 Fachbereich Energietechnik OPUS4-11063 Konferenzveröffentlichung Sattler, Johannes Christoph, sattler@sij.fh-aachen.de; Atti, Vikrama, ; Alexopoulos, Spiros, alexopoulos@sij.fh-aachen.de; Teixeira Boura, Cristiano José, Boura@sij.fh-aachen.de; Herrmann, Ulf, ulf.herrmann@sij.fh-aachen.de; Dutta, Siddharth, ; Kioutsioukis, Ioannis, DNI forecast tool for the smart operation of a parabolic trough collector system with concrete thermal energy storage: Theory, results and outlook This work presents a basic forecast tool for predicting direct normal irradiance (DNI) in hourly resolution, which the Solar-Institut Jülich (SIJ) is developing within a research project. The DNI forecast data shall be used for a parabolic trough collector (PTC) system with a concrete thermal energy storage (C-TES) located at the company KEAN Soft Drinks Ltd in Limassol, Cyprus. On a daily basis, 24-hour DNI prediction data in hourly resolution shall be automatically produced using free or very low-cost weather forecast data as input. The purpose of the DNI forecast tool is to automatically transfer the DNI forecast data on a daily basis to a main control unit (MCU). The MCU automatically makes a smart decision on the operation mode of the PTC system such as steam production mode and/or C-TES charging mode. The DNI forecast tool was evaluated using historical data of measured DNI from an on-site weather station, which was compared to the DNI forecast data. The DNI forecast tool was tested using data from 56 days between January and March 2022, which included days with a strong variation in DNI due to cloud passages. For the evaluation of the DNI forecast reliability, three categories were created and the forecast data was sorted accordingly. The result was that the DNI forecast tool has a reliability of 71.4 % based on the tested days. The result fulfils SIJ's aim to achieve a reliability of around 70 %, but SIJ aims to still improve the DNI forecast quality. Hannover TIB Open Publishing 2022 9 Seiten SolarPACES conference proceedings 28th International Conference on Concentrating Solar Power and Chemical Energy Systems, 27-30 September, Albuquerque, NM, USA VOL. 1 10.52825/solarpaces.v1i.731 https://doi.org/10.52825/solarpaces.v1i.731 Fachbereich Energietechnik OPUS4-11062 Konferenzveröffentlichung Sattler, Johannes Christoph, sattler@sij.fh-aachen.de; Schneider, Iesse Peer, ; Angele, Florian, ; Atti, Vikrama, ; Teixeira Boura, Cristiano José, boura@sij.fh-aachen.de; Herrmann, Ulf, ulf.herrmann@sij.fh-aachen.de Development of heliostat field calibration methods: Theory and experimental test results In this work, three patent pending calibration methods for heliostat fields of central receiver systems (CRS) developed by the Solar-Institut Jülich (SIJ) of the FH Aachen University of Applied Sciences are presented. The calibration methods can either operate in a combined mode or in stand-alone mode. The first calibration method, method A, foresees that a camera matrix is placed into the receiver plane where it is subjected to concentrated solar irradiance during a measurement process. The second calibration method, method B, uses an unmanned aerial vehicle (UAV) such as a quadrocopter to automatically fly into the reflected solar irradiance cross-section of one or more heliostats (two variants of method B were tested). The third calibration method, method C, foresees a stereo central camera or multiple stereo cameras installed e.g. on the solar tower whereby the orientations of the heliostats are calculated from the location detection of spherical red markers attached to the heliostats. The most accurate method is method A which has a mean accuracy of 0.17 mrad. The mean accuracy of method B variant 1 is 1.36 mrad and of variant 2 is 1.73 mrad. Method C has a mean accuracy of 15.07 mrad. For method B there is great potential regarding improving the measurement accuracy. For method C the collected data was not sufficient for determining whether or not there is potential for improving the accuracy. Hannover TIB Open Publishing 2022 9 Seiten SolarPACES conference proceedings 28th International Conference on Concentrating Solar Power and Chemical Energy Systems, 27-30 September, Albuquerque, NM, USA Vol. 1 10.52825/solarpaces.v1i.678 https://doi.org/10.52825/solarpaces.v1i.678 Fachbereich Energietechnik OPUS4-11060 Konferenzveröffentlichung Dachwald, Bernd, Dachwald@fh-aachen.de; Wurm, P., Mission analysis for an advanced solar photon thruster The so-called "compound solar sail", also known as "Solar Photon Thruster" (SPT), is a solar sail design concept, for which the two basic functions of the solar sail, namely light collection and thrust direction, are uncoupled. In this paper, we introduce a novel SPT concept, termed the Advanced Solar Photon Thruster (ASPT). This model does not suffer from the simplified assumptions that have been made for the analysis of compound solar sails in previous studies. We present the equations that describe the force, which acts on the ASPT. After a detailed design analysis, the performance of the ASPT with respect to the conventional flat solar sail (FSS) is investigated for three interplanetary mission scenarios: An Earth-Venus rendezvous, where the solar sail has to spiral towards the Sun, an Earth-Mars rendezvous, where the solar sail has to spiral away from the Sun, and an Earth-NEA rendezvous (to near-Earth asteroid 1996FG3), where a large orbital eccentricity change is required. The investigated solar sails have realistic near-term characteristic accelerations between 0.1 and 0.2mm/s2. Our results show that a SPT is not superior to the flat solar sail unless very idealistic assumptions are made. Amsterdam Elsevier 2009 13 60th International Astronautical Congress 2009, IAC 2009 Vol. 8 978-161567908-9 60th International Astronautical Congress 2009, IAC 2009; Daejeon; South Korea; 12 October 2009 through 16 October 2009 6838 6851 bezahl https://www.scopus.com/record/display.uri?eid=2-s2.0-77953533204&origin=inward&txGid=c637e44976e432afea2a2e2f828900f6 Fachbereich Luft- und Raumfahrttechnik OPUS4-11059 Teil eines Buches Dachwald, Bernd, Dachwald@fh-aachen.de Knopf, George K.; Otani, Yukitoshi Light propulsion systems for spacecraft Boca Raton CRC Press 2017 21 Optical nano and micro actuator technology 9781315217628 (eBook) 577 598 bezahl https://doi.org/10.1201/b13892 Fachbereich Luft- und Raumfahrttechnik OPUS4-11058 Konferenzveröffentlichung Dachwald, Bernd, Dachwald@fh-aachen.de; Wurm, P., Design concept and modeling of an advanced solar photon thruster The so-called "compound solar sail", also known as "Solar Photon Thruster" (SPT), holds the potential of providing significant performance advantages over the flat solar sail. Previous SPT design concepts, however, do not consider shadowing effects and multiple reflections of highly concentrated solar radiation that would inevitably destroy the gossamer sail film. In this paper, we propose a novel advanced SPT (ASPT) design concept that does not suffer from these oversimplifications. We present the equations that describe the thrust force acting on such a sail system and compare its performance with respect to the conventional flat solar sail. San Diego, Calif. American Astronautical Society 2009 17 Advances in the Astronautical Sciences 978-087703554-1 19th AAS/AIAA Space Flight Mechanics Meeting; Savannah, GA; United States; 8 February 2009 through 12 February 2009 723 740 bezahl https://www.scopus.com/record/display.uri?eid=2-s2.0-80053408846&origin=inward&txGid=c71a812af6b448da0e0cb316e77aae9c Fachbereich Luft- und Raumfahrttechnik OPUS4-11057 Konferenzveröffentlichung Gehler, M., ; Ober-Blöbaum, S., ; Dachwald, Bernd, Dachwald@fh-aachen.de Application of discrete mechanics and optimal control to spacecraft in non-keplerian motion around small solar system bodies Prolonged operations close to small solar system bodies require a sophisticated control logic to minimize propellant mass and maximize operational efficiency. A control logic based on Discrete Mechanics and Optimal Control (DMOC) is proposed and applied to both conventionally propelled and solar sail spacecraft operating at an arbitrarily shaped asteroid in the class of Itokawa. As an example, stand-off inertial hovering is considered, recently identified as a challenging part of the Marco Polo mission. The approach is easily extended to stand-off orbits. We show that DMOC is applicable to spacecraft control at small objects, in particular with regard to the fact that the changes in gravity are exploited by the algorithm to optimally control the spacecraft position. Furthermore, we provide some remarks on promising developments. Amsterdam Elsevier 2009 11 Procceedings of the 60th International Astronautical Congress 978-161567908-9 60th International Astronautical Congress 2009, IAC 2009; Daejeon; South Korea; 12 October 2009 through 16 October 2009 1360 1371 bezahl https://www.scopus.com/record/display.uri?eid=2-s2.0-77953551203&origin=inward&txGid=55a9d77f018557e6d78a7421419a8393 Fachbereich Luft- und Raumfahrttechnik OPUS4-11056 Konferenzveröffentlichung Funke, Harald, funke@fh-aachen.de; Beckmann, Nils, n.beckmann@fh-aachen.de; Stefan, Lukas, ; Keinz, Jan, keinz@fh-aachen.de Hydrogen combustor integration study for a medium range aircraft engine using the dry-low NOx "Micromix" combustion principle The feasibility study presents results of a hydrogen combustor integration for a Medium-Range aircraft engine using the Dry-Low-NOₓ Micromix combustion principle. Based on a simplified Airbus A320-type flight mission, a thermodynamic performance model of a kerosene and a hydrogen-powered V2530-A5 engine is used to derive the thermodynamic combustor boundary conditions. A new combustor design using the Dry-Low NOx Micromix principle is investigated by slice model CFD simulations of a single Micromix injector for design and off-design operation of the engine. Combustion characteristics show typical Micromix flame shapes and good combustion efficiencies for all flight mission operating points. Nitric oxide emissions are significant below ICAO CAEP/8 limits. For comparison of the Emission Index (EI) for NOₓ emissions between kerosene and hydrogen operation, an energy (kerosene) equivalent Emission Index is used. A full 15° sector model CFD simulation of the combustion chamber with multiple Micromix injectors including inflow homogenization and dilution and cooling air flows investigates the combustor integration effects, resulting NOₓ emission and radial temperature distributions at the combustor outlet. The results show that the integration of a Micromix hydrogen combustor in actual aircraft engines is feasible and offers, besides CO₂ free combustion, a significant reduction of NOₓ emissions compared to kerosene operation. New York ASME 2023 12 Seiten Proceedings of the ASME Turbo Expo 2023: Turbomachinery Technical Conference and Exposition. Volume 1: Aircraft Engine. Boston, Massachusetts, USA. June 26–30, 2023 978-0-7918-8693-9 Paper No. GT2023-102370, V001T01A022 10.1115/GT2023-102370 bezahl https://doi.org/10.1115/GT2023-102370 Fachbereich Luft- und Raumfahrttechnik OPUS4-11053 Wissenschaftlicher Artikel Bornheim, Tobias, ; Grieger, Niklas, ; Blaneck, Patrick Gustav, ; Bialonski, Stephan, bialonski@fh-aachen.de Speaker Attribution in German Parliamentary Debates with QLoRA-adapted Large Language Models The growing body of political texts opens up new opportunities for rich insights into political dynamics and ideologies but also increases the workload for manual analysis. Automated speaker attribution, which detects who said what to whom in a speech event and is closely related to semantic role labeling, is an important processing step for computational text analysis. We study the potential of the large language model family Llama 2 to automate speaker attribution in German parliamentary debates from 2017-2021. We fine-tune Llama 2 with QLoRA, an efficient training strategy, and observe our approach to achieve competitive performance in the GermEval 2023 Shared Task On Speaker Attribution in German News Articles and Parliamentary Debates. Our results shed light on the capabilities of large language models in automating speaker attribution, revealing a promising avenue for computational analysis of political discourse and the development of semantic role labeling systems. Regensburg Gesellschaft für Sprachtechnologie und Computerlinguistik 2024 13 Seiten Journal for language technology and computational linguistics : JLCL 37 1 10.21248/jlcl.37.2024.244 weltweit https://doi.org/10.21248/jlcl.37.2024.244 Fachbereich Medizintechnik und Technomathematik OPUS4-11049 Konferenzveröffentlichung Altherr, Lena, altherr@fh-aachen.de; Döring, Bernd, doering@fh-aachen.de; Frauenrath, Tobias, frauenrath@fh-aachen.de; Groß, Rolf, r.gross@fh-aachen.de; Mohan, Nijanthan, mohan@fh-aachen.de; Oyen, Marc, oyen@fh-aachen.de; Schnittcher, Lukas, ; Voß, Norbert, voss@fh-aachen.de Reiff-Stephan, Jörg; Jäkel, Jens; Schwarz, André DiggiTwin: ein interdisziplinäres Projekt zur Nutzung digitaler Zwillinge auf dem Weg zu einem klimaneutralen Gebäudebestand Im Hinblick auf die Klimaziele der Bundesrepublik Deutschland konzentriert sich das Projekt Diggi Twin auf die nachhaltige Gebäudeoptimierung. Grundlage für eine ganzheitliche Gebäudeüberwachung und -optimierung bildet dabei die Digitalisierung und Automation im Sinne eines Smart Buildings. Das interdisziplinäre Projekt der FH Aachen hat das Ziel, ein bestehendes Hochschulgebäude und einen Neubau an klimaneutrale Standards anzupassen. Im Rahmen des Projekts werden bekannte Verfahren, wie das Building Information Modeling (BIM), so erweitert, dass ein digitaler Gebäudezwilling entsteht. Dieser kann zur Optimierung des Gebäudebetriebs herangezogen werden, sowie als Basis für eine Erweiterung des Bewertungssystems Nachhaltiges Bauen (BNB) dienen. Mithilfe von Sensortechnologie und künstlicher Intelligenz kann so ein präzises Monitoring wichtiger Gebäudedaten erfolgen, um ungenutzte Energieeinsparpotenziale zu erkennen und zu nutzen. Das Projekt erforscht und setzt methodische Erkenntnisse zu BIM und digitalen Gebäudezwillingen praxisnah um, indem es spezifische Fragen zur Energie- und Ressourceneffizienz von Gebäuden untersucht und konkrete Lösungen für die Gebäudeoptimierung entwickelt. Leipzig le-tex publishing services GmbH 2024 5 Tagungsband AALE 2024 : Fit für die Zukunft: praktische Lösungen für die industrielle Automation 978-3-910103-02-3 20. AALE-Konferenz. Bielefeld, 06.03.-08.03.2024 (Tagungsband unter https://doi.org/10.33968/2024.29) 341 346 10.33968/2024.67 weltweit https://doi.org/10.33968/2024.67 Fachbereich Elektrotechnik und Informationstechnik OPUS4-11048 Konferenzveröffentlichung Wittig, M., ; Rütters, René, rene.ruetters@fh-aachen.de; Bragard, Michael, bragard@fh-aachen.de Reiff-Stephan, Jörg; Jäkel, Jens; Schwarz, André Application of RL in control systems using the example of a rotatory inverted pendulum In this paper, the use of reinforcement learning (RL) in control systems is investigated using a rotatory inverted pendulum as an example. The control behavior of an RL controller is compared to that of traditional LQR and MPC controllers. This is done by evaluating their behavior under optimal conditions, their disturbance behavior, their robustness and their development process. All the investigated controllers are developed using MATLAB and the Simulink simulation environment and later deployed to a real pendulum model powered by a Raspberry Pi. The RL algorithm used is Proximal Policy Optimization (PPO). The LQR controller exhibits an easy development process, an average to good control behavior and average to good robustness. A linear MPC controller could show excellent results under optimal operating conditions. However, when subjected to disturbances or deviations from the equilibrium point, it showed poor performance and sometimes instable behavior. Employing a nonlinear MPC Controller in real time was not possible due to the high computational effort involved. The RL controller exhibits by far the most versatile and robust control behavior. When operated in the simulation environment, it achieved a high control accuracy. When employed in the real system, however, it only shows average accuracy and a significantly greater performance loss compared to the simulation than the traditional controllers. With MATLAB, it is not yet possible to directly post-train the RL controller on the Raspberry Pi, which is an obstacle to the practical application of RL in a prototyping or teaching setting. Nevertheless, RL in general proves to be a flexible and powerful control method, which is well suited for complex or nonlinear systems where traditional controllers struggle. Leipzig le-tex publishing services GmbH 2024 7 Tagungsband AALE 2024 : Fit für die Zukunft: praktische Lösungen für die industrielle Automation 978-3-910103-02-3 20. AALE-Konferenz. Bielefeld, 06.03.-08.03.2024. (Tagungsband unter https://doi.org/10.33968/2024.29) 241 248 10.33968/2024.53 weltweit https://doi.org/10.33968/2024.53 Fachbereich Elektrotechnik und Informationstechnik OPUS4-11047 misc Bragard, Michael, bragard@fh-aachen.de; Hüning, Felix, huening@fh-aachen.de; Kowalewski, Paul, Vorrichtung zur Relativlagenbestimmung [Offenlegungschrift] Die Erfindung betrifft eine Vorrichtung zur Bestimmung einer Relativlage zwischen einem feststehenden Teil und einem zu demselben in eine Bewegungsrichtung bewegbaren beweglichen Teil, wobei der feststehende Teil mit einem Wiegandsensor versehen ist, wobei der Wiegandsensor zwischen zwei gegenpolig zueinander ausgebildeten Permanentmagneten angeordnet ist und dass der bewegliche Teil eine Mehrzahl von beabstandet zueinander angeordneten Magnetisierungsstegen aus einem magnetisch leitenden Material aufweist, die in der Bewegungsrichtung zumindest eine gleich große Erstreckung aufweisen wie der Permanentmagnet, dass ein Abstand zwischen benachbarten Magnetisierungsstegen derart gewählt ist, dass in einer ersten Relativlage ein erster Permanentmagnet von einem der Magnetisierungsstege überdeckt ist und ein zweiter Permanentmagnet nicht von einem der Magnetisierungsstege überdeckt ist. 2023 Offenlegungschrift zu DE102022115350A1 2023.12.21 weltweit Patent ansehen bei DPMA Fachbereich Elektrotechnik und Informationstechnik OPUS4-11045 Konferenzveröffentlichung Grund, Raphael M., ; Altherr, Lena, altherr@fh-aachen.de Reiff-Stephan, Jörg; Jäkel, Jens; Schwarz, André Development of an open source energy disaggregation tool for the home automation platform Home Assistant In order to reduce energy consumption of homes, it is important to make transparent which devices consume how much energy. However, power consumption is often only monitored aggregated at the house energy meter. Disaggregating this power consumption into the contributions of individual devices can be achieved using Machine Learning. Our work aims at making state of the art disaggregation algorithms accessibe for users of the open source home automation platform Home Assistant. Leipzig le-tex publishing services GmbH 2023 10 Seiten Tagungsband AALE 2023 : mit Automatisierung gegen den Klimawandel 978-3-910103-01-6 19. AALE-Konferenz. Luxemburg, 08.03.-10.03.2023. BTS Connected Buildings & Cities Luxemburg (Tagungsband unter https://doi.org/10.33968/2023.01) 11 20 10.33968/2023.02 weltweit https://doi.org/10.33968/2023.02 Fachbereich Elektrotechnik und Informationstechnik OPUS4-11044 Wissenschaftlicher Artikel Kahmann, Stephanie L., ; Rausch, Valentin, ; Plümer, Jonathan, ; Müller, Lars P., ; Pieper, Martin, pieper@fh-aachen.de; Wegmann, Kilian, The automized fracture edge detection and generation of three-dimensional fracture probability heat maps With proven impact of statistical fracture analysis on fracture classifications, it is desirable to minimize the manual work and to maximize repeatability of this approach. We address this with an algorithm that reduces the manual effort to segmentation, fragment identification and reduction. The fracture edge detection and heat map generation are performed automatically. With the same input, the algorithm always delivers the same output. The tool transforms one intact template consecutively onto each fractured specimen by linear least square optimization, detects the fragment edges in the template and then superimposes them to generate a fracture probability heat map. We hypothesized that the algorithm runs faster than the manual evaluation and with low (< 5 mm) deviation. We tested the hypothesis in 10 fractured proximal humeri and found that it performs with good accuracy (2.5 mm ± 2.4 mm averaged Euclidean distance) and speed (23 times faster). When applied to a distal humerus, a tibia plateau, and a scaphoid fracture, the run times were low (1-2 min), and the detected edges correct by visual judgement. In the geometrically complex acetabulum, at a run time of 78 min some outliers were considered acceptable. An automatically generated fracture probability heat map based on 50 proximal humerus fractures matches the areas of high risk of fracture reported in medical literature. Such automation of the fracture analysis method is advantageous and could be extended to reduce the manual effort even further. Amsterdam Elsevier 2022 7 Seiten Medical Engineering & Physics 2022 110 campus https://doi.org/10.1016/j.medengphy.2022.103913 Fachbereich Energietechnik OPUS4-11043 Wissenschaftlicher Artikel Schoenrock, Britt, ; Muckelt, Paul E., ; Hastermann, Maria, ; Albracht, Kirsten, albracht@fh-aachen.de; MacGregor, Robert, ; Martin, David, ; Gunga, Hans-Christian, ; Salanova, Michele, ; Stokes, Maria J., ; Warner, Martin B., ; Blottner, Dieter, Muscle stiffness indicating mission crew health in space Muscle function is compromised by gravitational unloading in space affecting overall musculoskeletal health. Astronauts perform daily exercise programmes to mitigate these effects but knowing which muscles to target would optimise effectiveness. Accurate inflight assessment to inform exercise programmes is critical due to lack of technologies suitable for spaceflight. Changes in mechanical properties indicate muscle health status and can be measured rapidly and non-invasively using novel technology. A hand-held MyotonPRO device enabled monitoring of muscle health for the first time in spaceflight (> 180 days). Greater/maintained stiffness indicated countermeasures were effective. Tissue stiffness was preserved in the majority of muscles (neck, shoulder, back, thigh) but Tibialis Anterior (foot lever muscle) stiffness decreased inflight vs. preflight (p < 0.0001; mean difference 149 N/m) in all 12 crewmembers. The calf muscles showed opposing effects, Gastrocnemius increasing in stiffness Soleus decreasing. Selective stiffness decrements indicate lack of preservation despite daily inflight countermeasures. This calls for more targeted exercises for lower leg muscles with vital roles as ankle joint stabilizers and in gait. Muscle stiffness is a digital biomarker for risk monitoring during future planetary explorations (Moon, Mars), for healthcare management in challenging environments or clinical disorders in people on Earth, to enable effective tailored exercise programmes. London Springer Nature 2024 13 Seiten Scientific Reports 14 Corresponding author: Dieter Blottner Article number: 4196 10.1038/s41598-024-54759-6 weltweit https://doi.org/10.1038/s41598-024-54759-6 Fachbereich Medizintechnik und Technomathematik OPUS4-11042 Konferenzveröffentlichung Gömmel, A., ; Butenweg, Christoph, christoph.butenweg@fh-aachen.de; Kob, M., A fluid-structure interaction model of vocal fold oscillation Since fluid-structure interaction within the finite-element method is state of the art in many engineering fields, this method is used in voice analysis. A quasi two-dimensional model of the vocal folds including the ventricular folds is presented. First results of self-sustained vocal fold oscillation are presented and possibilities as well as limitations are discussed. 2007 1 5th International Workshop on Models and Analysis of Vocal Emissions for Biomedical Applications, MAVEBA 2007 978-888453674-7 5th International Workshop on Models and Analysis of Vocal Emissions for Biomedical Applications, MAVEBA 2007; Florence; Italy; 13 December 2007 through 15 December 2007 127 128 Fachbereich Energietechnik OPUS4-11041 Wissenschaftlicher Artikel Baumgartner, Werner, ; Fidler, Florian, ; Weth, Agnes, ; Habbecke, Martin, ; Jakob, Peter, ; Butenweg, Christoph, christoph.butenweg@fh-aachen.de; Böhme, Wolfgang, Investigating the locomotion of the sandfish in desert sand using NMR-Imaging The sandfish (Scincus scincus) is a lizard having the remarkable ability to move through desert sand for significant distances. It is well adapted to living in loose sand by virtue of a combination of morphological and behavioural specializations. We investigated the bodyform of the sandfish using 3D-laserscanning and explored its locomotion in loose desert sand using fast nuclear magnetic resonance (NMR) imaging. The sandfish exhibits an in-plane meandering motion with a frequency of about 3 Hz and an amplitude of about half its body length accompanied by swimming-like (or trotting) movements of its limbs. No torsion of the body was observed, a movement required for a digging-behaviour. Simple calculations based on the Janssen model for granular material related to our findings on bodyform and locomotor behaviour render a local decompaction of the sand surrounding the moving sandfish very likely. Thus the sand locally behaves as a viscous fluid and not as a solid material. In this fluidised sand the sandfish is able to "swim" using its limbs. San Francisco, California, US Plos 2008 10 Seiten PLOS ONE 3 10 10.1371/journal.pone.0003309 weltweit https://journals.plos.org/plosone/article/metrics?id=10.1371/journal.pone.0003309 Fachbereich Energietechnik OPUS4-11039 Teil eines Buches Finkenberger, Isabel Maria, finkenberger@fh-aachen.de Büscher, Barbara; Krasny, Elke; Ortmann, Lucie Transformatives Handeln als disziplinüberschreitende, kollektive Aktion. Stadtentwicklung trifft künstlerische und kollaborative Handlungspraxen Wien Turia + Kant 2024 14 Porös-Werden : geteilte Räume, urbane Dramaturgien, performatives Kuratieren 978-3-98514-543-0 144 158 weltweit https://www.turia.at/pdf/Poroes-Werden_2024_open-access.pdf (PDF Download) Fachbereich Architektur OPUS4-11038 Teil eines Buches Kraft, Bodo, kraft@fh-aachen.de; Kohl, Philipp, p.kohl@fh-aachen.de; Meinecke, Matthias, meinecke@fh-aachen.de Bernert, Christian; Scheurer, Steffen; Wehnes, Harald Analyse und Nachverfolgung von Projektzielen durch Einsatz von Natural Language Processing UVK Verlag 2024 10 KI in der Projektwirtschaft : was verändert sich durch KI im Projektmanagement? 978-3-3811-1132-9 (Online) 157 167 10.24053/9783381111329 bezahl https://doi.org/10.24053/9783381111329 Fachbereich Medizintechnik und Technomathematik OPUS4-11037 Bachelorarbeit Latz, Annika, Konzeptentwicklung einer spielerischen Lernanwendung für Studierende Ziel der Arbeit war es eine spielerische Lernanwendung für Studierende der FH-Aachen zu entwickeln, um das individuelle Lernen zu fördern. Dabei lag der Fokus auf der Konzeptentwicklung eines Serious Games für die Fachhochschule Aachen. Abgeleitet von Motivationstheorien, Game Design Frameworks und Eigenschaften von digitalen spielerischen Konzepten wurde ein Vorgehensmodell zur Konzeptentwicklung eines Serious Games erstellt. Wichtige Punkte für die Anwendung waren eine intensive Austauschmöglichkeiten für Studierende und das Integrieren dieser in die Lehrveranstaltungen der FH-Aachen. In der abschließenden Evaluation wurde positives Feedback der Studierenden eingeholt und damit das Ziel der Arbeit erreicht. Zusätzlich wurde für das erarbeitete Konzept die Wirtschaftlichkeit überprüft. Dafür wurde während der Bearbeitungszeit mit einem aufgestellten Team ein Business Plan für das Förderprogramm Start-Up transfer.NRW entwickelt. 2021 XIV, 136 Seiten weltweit Fachbereich Elektrotechnik und Informationstechnik OPUS4-11036 Wissenschaftlicher Artikel Hoffstadt, Kevin, ; Nikolausz, Marcell, ; Krafft, Simone, krafft@fh-aachen.de; Bonatelli, Maria, ; Kumar, Vivekanantha, ; Harms, Hauke, ; Kuperjans, Isabel, kuperjans@fh-aachen.de Optimization of the ex situ biomethanation of hydrogen and carbon dioxide in a novel meandering plug flow reactor: start-up phase and flexible operation Basel MDPI 2024 18 Seiten Bioengineering 11 2 10.3390/bioengineering11020165 weltweit https://doi.org/10.3390/bioengineering11020165 Fachbereich Chemie und Biotechnologie OPUS4-11030 Wissenschaftlicher Artikel Frauenrath, Tobias, ; Hezel, Fabian, ; Heinrichs, Uwe, ; Kozerke, Sebastian, ; Utting, Jane, ; Kob, Malte, ; Butenweg, Christoph, Christoph.Butenweg@fh-aachen.de; Boesiger, Peter, ; Niendorf, Thoralf, Feasibility of Cardiac Gating Free of Interference With Electro-Magnetic Fields at 1.5 Tesla, 3.0 Tesla and 7.0 Tesla Using an MR-Stethoscope Philadelphia, Pa Lippincott Williams & Wilkins ; (via Ovid) 2009 8 Investigative Radiology 44 9 539 547 10.1097/RLI.0b013e3181b4c15e campus https://journals.lww.com/investigativeradiology/fulltext/2009/09000/feasibility_of_cardiac_gating_free_of_interference.9.aspx Fachbereich Energietechnik OPUS4-10891 Wissenschaftlicher Artikel Uysal, Karya, uysal@fh-aachen.de; Firat, Ipek Serat, firat@fh-aachen.de; Creutz, Till, till.creutz@fh-aachen.de; Aydin, Inci Cansu, ; Artmann, Gerhard, artmann@fh-aachen.de; Teusch, Nicole, ; Temiz Artmann, Aysegül, a.artmann@fh-aachen.de A novel in vitro wound healing assay using free-standing, ultra-thin PDMS membranes Advances in polymer science have significantly increased polymer applications in life sciences. We report the use of free-standing, ultra-thin polydimethylsiloxane (PDMS) membranes, called CellDrum, as cell culture substrates for an in vitro wound model. Dermal fibroblast monolayers from 28- and 88-year-old donors were cultured on CellDrums. By using stainless steel balls, circular cell-free areas were created in the cell layer (wounding). Sinusoidal strain of 1 Hz, 5% strain, was applied to membranes for 30 min in 4 sessions. The gap circumference and closure rate of un-stretched samples (controls) and stretched samples were monitored over 4 days to investigate the effects of donor age and mechanical strain on wound closure. A significant decrease in gap circumference and an increase in gap closure rate were observed in trained samples from younger donors and control samples from older donors. In contrast, a significant decrease in gap closure rate and an increase in wound circumference were observed in the trained samples from older donors. Through these results, we propose the model of a cell monolayer on stretchable CellDrums as a practical tool for wound healing research. The combination of biomechanical cell loading in conjunction with analyses such as gene/protein expression seems promising beyond the scope published here. Basel MDPI 2022 Artikel 22 membranes 2023 This article belongs to the Special Issue "Latest Scientific Discoveries in Polymer Membranes" 13(1) 10.3390/membranes13010022 weltweit https://doi.org/10.3390/membranes13010022 Fachbereich Medizintechnik und Technomathematik OPUS4-11025 Wissenschaftlicher Artikel Finkenberger, Isabel Maria, finkenberger@fh-aachen.de Wohnen als Produktionsgemeinschaftsaufgabe Wohnen als neue soziale Frage ist mehr als die Produktion neuer Formen von Wohnen und deren architektonischer Gestalt, und auch mehr als nur die Umsetzung sich verändernder, jedoch individuell formulierter Wohnwünsche. Sie spannt sich auf zwischen gesellschafts- und nachhaltigkeitspolitischen, hardcore-kapitalistischen und globalen Rahmenbedingungen, Hardware und Software, Individuum und Gemeinwohl, Konsum und Mitgestaltung. Entscheidend sind die Akteure und die Art und Weise, wie und nach welchen Maßstäben sie handeln. Entscheidend ist aber auch, Wohnen sowohl kontextuell wie auch programmatisch neu zu denken und dadurch zu neuen Mischungen, Nachbarschaften und Bewertungskriterien einer Projekt- und Stadtentwicklung zu kommen, die mehr als die Summe seiner Einzelteile wollen - ein gutes Leben für Alle abseits der Frage des Geldbeutels und der sozialen Zugehörigkeit. Münster Aschendorff 2021 11 Jahrbuch für Christliche Sozialwissenschaften 62 31 42 10.17879/jcsw-2021-3537 weltweit https://doi.org/10.17879/jcsw-2021-3537 Fachbereich Architektur OPUS4-11026 Teil eines Buches Finkenberger, Isabel Maria, finkenberger@fh-aachen.de Die Stadt als städtisch-theatrale Versuchsanordnung: Wie wollen wir in Zukunft leben und welche Stadt brauchen wir dafür? Bielefeld transcript 2018 9 Un/Certain Futures - Rollen des Designs in gesellschaftlichen Transformationsprozessen 9783839443323 86 95 https://doi.org/10.1515/9783839443323-009 weltweit https://doi.org/10.1515/9783839443323-009 Fachbereich Architektur OPUS4-11031 Wissenschaftlicher Artikel Finkenberger, Isabel Maria, finkenberger@fh-aachen.de Transformatives Forschen, Lehren und Handeln im Rheinischen Braunkohlerevier Die Institution Hochschule hat das Potenzial, über transformatives Forschen und Lehren und den entsprechenden Wissenstransfer in den lokalen Kontext strategisch-verlässliche Partnerin der Großen Transformation zur Nachhaltigkeit zu werden und bei der Ausbildung von Pionierinnen und Pionieren des Wandels mitzuwirken. Der Lehr- und Forschungsschwerpunkt „Zukunftsfähige Transformation" am Fachbereich Architektur der FH Aachen widmet sich seit 2020 dem Tagebauumfeld Hambach im Rheinischen Revier, um dort angewandt und in Kooperation neue Narrative, innovative Prozesse, ortsbezogene Konzepte und strategische Projekte zu entwickeln und umzusetzen. Berlin vhw 2022 3 Forum Wohnen und Stadtentwicklung 2022 2 69 72 weltweit https://www.vhw.de/publikationen/forum-wohnen-und-stadtentwicklung/archiv/archiv-detail/magazin/heft-22022-stadtentwicklung-und-hochschulen-jenseits-der-metropolen/ Fachbereich Architektur OPUS4-11032 Wissenschaftlicher Artikel Finkenberger, Isabel Maria, finkenberger@fh-aachen.de; Schlaich, Christoph, Mehr als Wohnen. Vom Zusammenleben in integrierten Nachbarschaften Neue Dörfer braucht das Land! Dörfer in der Stadt und Dörfer auf dem Land (…). Die Planung und Gestaltung nachhaltiger Raumsysteme, die durch ein neues Verständnis des gemeinschaftlichen Besitzes (und dessen Nutzung) ressourcenfressende Individualisierungstendenzen unserer Gesellschaft überwinden, aber zugleich größtmöglichen Freiraum für eine individuelle Persönlichkeitsentfaltung zur Verfügung stellen." Dieses Zitat der Hamburger Initiative "Wir sind Dorf" beschreibt eine aktuelle Diskussion in unserer Gesellschaft, die sowohl in der Forschung und forschungsgeleiteten Initiativen, in Politik und Planung als auch in der Bürger-schaft stattfindet. Sie wird nicht nur auf wissenschaftlichen Veranstaltungen geführt, sondern auch in konkreten Projekten für integrative Lebenswelten, die Fragestellungen von Ernährung und Energieversorgung, von Arbeit und Ökonomie, aber auch eines neuen räumlichen und sozialen Miteinanders einbeziehen. Anders als bei den weit verbreiteten Baugruppen geht es nicht ausschließlich um die Schaffung von Wohnraum. Die Nachbarschaftsidee verbindet das Bedürfnis nach gemeinschaftlichem Wohnen und Wirtschaften mit einer neuen Werteorientierung, die auf persönlicher Verantwortungsübernahme beruht. Bonn Bundeszentrale für politische Bildung - bpb 2014 6 APuZ - Aus Politik und Zeitgeschichte 2014 20-21 46 52 weltweit https://www.bpb.de/shop/zeitschriften/apuz/183453/mehr-als-wohnen-vom-zusammenleben-in-integrierten-nachbarschaften/ Fachbereich Architektur OPUS4-11033 Wissenschaftlicher Artikel Finkenberger, Isabel Maria, finkenberger@fh-aachen.de Vox populi. (Transformations-)potenziale nachkriegsmoderner Freiraumressourcen Heute wie damals werden die großzügigen und offenen Siedlungsstrukturen der ersten Nachkriegsjahrzehnte mit ihrem hohen Anteil an "Grün" vielfach geschätzt und als solche nicht grundlegend hinterfragt. "Grün" verheißt im Allgemeinen Licht, Luft und Sonne, Freizeit und Erholung und gilt als etwas Wünschenswertes im städtischen Kontext. Unbeachtet bleibt, dass dem Begriff "Grün" zunächst keine Eigenschaften oder Qualitäten zugewiesen sind - er sagt noch lange nichts über dessen räumliche Qualität, dessen Nutzbarkeit, Erreichbarkeit und Zugänglichkeit aus. Abstandsgrün und Straßenbegleitgrün ist eben auch "Grün". Neben einer quantitativen Argumentation, welche ökologischen Aspekte wie Biotopvernetzung, Stadt- und Mikroklima berücksichtigt, sollten wir verstärkt qualitativ denken und damit die Grundlage für einen erweiterten und wesentlich differenzierteren Diskurs über urbane Freiräume ebnen. Berlin Patzer 2014 4 Stadt+Grün 2014 1 31 35 weltweit https://stadtundgruen.de/artikel/transformations-potenziale-nachkriegsmoderner-freiraumressourcen-vox-populi-8201 Fachbereich Architektur OPUS4-11034 Teil eines Buches Finkenberger, Isabel Maria, finkenberger@fh-aachen.de Bredenbeck, Martin Vox populi. (Transformations-)potenziale nachkriegsmoderner Freiraumressourcen Bonn BHU 2013 7 Grün modern - Gärten und Parks der 1950er bis 1970er Jahre 9783925374357 Ein Kulturerbe als Herausforderung für Denkmalpflege und Vermittlungsarbeit ; Dokumentation der Tagung am 15. und 16. Oktober 2013 in Hamburg 31 38 Fachbereich Architektur OPUS4-11027 Wissenschaftlicher Artikel Finkenberger, Isabel Maria, finkenberger@fh-aachen.de Strukturwandel als transformative Wende Abingdon Taylor & Francis 2022 8 disP: The Planning Review 58 3 86 94 10.1080/02513625.2022.2158603 campus https://fhb-aachen.digibib.net/search/eds/record/asu:160890573/eds-fulltext Fachbereich Architektur OPUS4-11028 Teil eines Buches Finkenberger, Isabel Maria, finkenberger@fh-aachen.de Pufke, Andrea Räumliche Transformation als Planungsaufgabe Pulheim LVR-Amt für Denkmalpflege im Rheinland 2022 7 Zurück in die Zukunft. Denkmalpflege und Strukturwandel im Rheinischen Revier Mitteilungen aus dem LVR-Amt für Denkmalpflege im Rheinland 39 : Zurück in die Zukunft. Denkmalpflege und Strukturwandel im Rheinischen Revier. Dokumentation zum 7. Rheinischen Tag für Denkmalpflege in Morschenich, 2. Juni 2022 70 77 weltweit https://denkmalpflege.lvr.de/media/denkmalpflege/publikationen/online_publikationen/Heft39_Denkmalpflege_und_Strukturwandel.pdf Fachbereich Architektur OPUS4-11024 Teil eines Buches Peterson, Leif Arne, peterson@fh-aachen.de Schlüter, Dominik Holzbau Norderstedt BoD 2021 2 Wofür braucht man das eigentlich? Ein Handbuch für Mathematiklehrkräfte der Sekundarstufe I und II 978-3-7543-2606-0 21 23 Fachbereich Bauingenieurwesen OPUS4-11023 Teil eines Buches Duffner, Markus, duffner@fh-aachen.de; Uibel, Thomas, uibel@fh-aachen.de; Peterson, Leif Arne, peterson@fh-aachen.de; Moorkamp, Wilfried, moorkamp@fh-aachen.de Fouad, Nabil A. Cross Layers Light - Ein ressourceneffizientes und recyclebares Holz-Wandsystem Ein neues tragendes, lagenweise aufgebautes Holzbau-Wandsystem und seine ökonomische und statische Entwicklung werden vorgestellt. Randbedingungen wie Nachhaltigkeit, Ressourceneffizienz und eine beanspruchungsadaptive Konstruktionsweise sind für diese innovative Bauteilentwicklung von zentraler Bedeutung. Eine wesentliche Herausforderung ist die Herstellung der Verbindung der Lagen untereinander zu einem bauphysikalisch und statisch leistungsfähigen Wandsystem. Die Tragfähigkeit und Steifigkeit verschiedener Verbindungsvarianten wurden ebenso wie die Eigenschaften der Wandelemente analytisch, numerisch und experimentell untersucht. Berlin Ernst & Sohn 2023 18 Bauphysik Kalender 2023: Nachhaltigkeit 9783433033890 (Print) 483 501 10.1002/9783433611289.ch13 campus https://doi.org/10.1002/9783433611289.ch13 Fachbereich Bauingenieurwesen