@misc{StadtmuellerTippkoetterUlber2013, author = {Stadtm{\"u}ller, Ralf and Tippk{\"o}tter, Nils and Ulber, Roland}, title = {A method for production of single-stranded nucleic acids [Europ{\"a}ische Patentanmeldung]}, publisher = {Europ{\"a}isches Patentamt}, address = {Den Hague}, pages = {14 Seiten}, year = {2013}, language = {en} } @article{DigelTrzewikDemircietal.2004, author = {Digel, Ilya and Trzewik, J{\"u}rgen and Demirci, Taylan and Temiz Artmann, Ayseg{\"u}l}, title = {Response of fibroblasts to cyclic mechanical stress : a proteome approach / Digel, I. ; Trzewik, J. ; Demirci, T. ; Temiz Artmann, A. ; Artmann, G. M.}, series = {Biomedizinische Technik. 49 (2004), H. Erg.-Bd. 2}, journal = {Biomedizinische Technik. 49 (2004), H. Erg.-Bd. 2}, isbn = {0932-4666}, pages = {1042 -- 1043}, year = {2004}, language = {en} } @article{BlankeHagenkampDoeringetal.2021, author = {Blanke, Tobias and Hagenkamp, Markus and D{\"o}ring, Bernd and G{\"o}ttsche, Joachim and Reger, Vitali and Kuhnhenne, Markus}, title = {Net-exergetic, hydraulic and thermal optimization of coaxial heat exchangers using fixed flow conditions instead of fixed flow rates}, series = {Geothermal Energy}, volume = {9}, journal = {Geothermal Energy}, number = {Article number: 19}, publisher = {Springer}, address = {Berlin}, issn = {2195-9706}, doi = {10.1186/s40517-021-00201-3}, pages = {23 Seiten}, year = {2021}, abstract = {Previous studies optimized the dimensions of coaxial heat exchangers using constant mass fow rates as a boundary condition. They show a thermal optimal circular ring width of nearly zero. Hydraulically optimal is an inner to outer pipe radius ratio of 0.65 for turbulent and 0.68 for laminar fow types. In contrast, in this study, fow conditions in the circular ring are kept constant (a set of fxed Reynolds numbers) during optimization. This approach ensures fxed fow conditions and prevents inappropriately high or low mass fow rates. The optimization is carried out for three objectives: Maximum energy gain, minimum hydraulic efort and eventually optimum net-exergy balance. The optimization changes the inner pipe radius and mass fow rate but not the Reynolds number of the circular ring. The thermal calculations base on Hellstr{\"o}m's borehole resistance and the hydraulic optimization on individually calculated linear loss of head coefcients. Increasing the inner pipe radius results in decreased hydraulic losses in the inner pipe but increased losses in the circular ring. The net-exergy diference is a key performance indicator and combines thermal and hydraulic calculations. It is the difference between thermal exergy fux and hydraulic efort. The Reynolds number in the circular ring is instead of the mass fow rate constant during all optimizations. The result from a thermal perspective is an optimal width of the circular ring of nearly zero. The hydraulically optimal inner pipe radius is 54\% of the outer pipe radius for laminar fow and 60\% for turbulent fow scenarios. Net-exergetic optimization shows a predominant infuence of hydraulic losses, especially for small temperature gains. The exact result depends on the earth's thermal properties and the fow type. Conclusively, coaxial geothermal probes' design should focus on the hydraulic optimum and take the thermal optimum as a secondary criterion due to the dominating hydraulics.}, language = {en} } @inproceedings{DuranParedesMottaghyHerrmannetal.2020, author = {Duran Paredes, Ludwin and Mottaghy, Darius and Herrmann, Ulf and Groß, Rolf Fritz}, title = {Online ground temperature and soil moisture monitoring of a shallow geothermal system with non-conventional components}, series = {EGU General Assembly 2020}, booktitle = {EGU General Assembly 2020}, year = {2020}, abstract = {We present first results from a newly developed monitoring station for a closed loop geothermal heat pump test installation at our campus, consisting of helix coils and plate heat exchangers, as well as an ice-store system. There are more than 40 temperature sensors and several soil moisture content sensors distributed around the system, allowing a detailed monitoring under different operating conditions.In the view of the modern development of renewable energies along with the newly concepts known as Internet of Things and Industry 4.0 (high-tech strategy from the German government), we created a user-friendly web application, which will connect the things (sensors) with the open network (www). Besides other advantages, this allows a continuous remote monitoring of the data from the numerous sensors at an arbitrary sampling rate.Based on the recorded data, we will also present first results from numerical simulations, taking into account all relevant heat transport processes.The aim is to improve the understanding of these processes and their influence on the thermal behavior of shallow geothermal systems in the unsaturated zone. This will in turn facilitate the prediction of the performance of these systems and therefore yield an improvement in their dimensioning when designing a specific shallow geothermal installation.}, language = {en} } @article{ArinkinDigelPorstetal.2014, author = {Arinkin, Vladimir and Digel, Ilya and Porst, Dariusz and Temiz Artmann, Ayseg{\"u}l and Artmann, Gerhard}, title = {Phenotyping date palm varieties via leaflet cross-sectional imaging and artificial neural network application}, series = {BMC bioinformatics}, volume = {15}, journal = {BMC bioinformatics}, number = {55}, issn = {1471-2105}, doi = {10.1186/1471-2105-15-55}, pages = {1 -- 8}, year = {2014}, abstract = {Background True date palms (Phoenix dactylifera L.) are impressive trees and have served as an indispensable source of food for mankind in tropical and subtropical countries for centuries. The aim of this study is to differentiate date palm tree varieties by analysing leaflet cross sections with technical/optical methods and artificial neural networks (ANN). Results Fluorescence microscopy images of leaflet cross sections have been taken from a set of five date palm tree cultivars (Hewlat al Jouf, Khlas, Nabot Soltan, Shishi, Um Raheem). After features extraction from images, the obtained data have been fed in a multilayer perceptron ANN with backpropagation learning algorithm. Conclusions Overall, an accurate result in prediction and differentiation of date palm tree cultivars was achieved with average prediction in tenfold cross-validation is 89.1\% and reached 100\% in one of the best ANN.}, language = {en} } @article{HeinEubanksHibberdetal.2020, author = {Hein, Andreas M. and Eubanks, T. Marshall and Hibberd, Adam and Fries, Dan and Schneider, Jean and Lingam, Manasvi and Kennedy, Robert and Perakis, Nikolaos and Dachwald, Bernd and Kervella, Pierre}, title = {Interstellar Now! Missions to and sample returns from nearby interstellar objects}, publisher = {Elsevier}, address = {Amsterdam}, pages = {1 -- 8}, year = {2020}, abstract = {The recently discovered first high velocity hyperbolic objects passing through the Solar System, 1I/'Oumuamua and 2I/Borisov, have raised the question about near term missions to Interstellar Objects. In situ spacecraft exploration of these objects will allow the direct determination of both their structure and their chemical and isotopic composition, enabling an entirely new way of studying small bodies from outside our solar system. In this paper, we map various Interstellar Object classes to mission types, demonstrating that missions to a range of Interstellar Object classes are feasible, using existing or near-term technology. We describe flyby, rendezvous and sample return missions to interstellar objects, showing various ways to explore these bodies characterizing their surface, dynamics, structure and composition. Interstellar objects likely formed very far from the solar system in both time and space; their direct exploration will constrain their formation and history, situating them within the dynamical and chemical evolution of the Galaxy. These mission types also provide the opportunity to explore solar system bodies and perform measurements in the far outer solar system.}, language = {en} } @article{FerreinSteinbauer2016, author = {Ferrein, Alexander and Steinbauer, Gerald}, title = {20 Years of RoboCup - A Subjective Retrospection}, series = {KI - K{\"u}nstliche Intelligenz}, volume = {30}, journal = {KI - K{\"u}nstliche Intelligenz}, number = {3}, publisher = {Springer}, address = {Berlin}, issn = {1610-1987}, doi = {10.1007/s13218-016-0449-5}, pages = {225 -- 232}, year = {2016}, abstract = {This summer, RoboCup competitions were held for the 20th time in Leipzig, Germany. It was the second time that RoboCup took place in Germany, 10 years after the 2006 RoboCup in Bremen. In this article, we give an overview on the latest developments of RoboCup and what happened in the different leagues over the last decade. With its 20th edition, RoboCup clearly is a success story and a role model for robotics competitions. From our personal view point, we acknowledge this by giving a retrospection about what makes RoboCup such a success.}, language = {en} } @article{CampenKowalskiLyonsetal.2019, author = {Campen, R. and Kowalski, Julia and Lyons, W.B. and Tulaczyk, S. and Dachwald, Bernd and Pettit, E. and Welch, K. A. and Mikucki, J.A.}, title = {Microbial diversity of an Antarctic subglacial community and high-resolution replicate sampling inform hydrological connectivity in a polar desert}, series = {Environmental Microbiology}, journal = {Environmental Microbiology}, number = {accepted article}, publisher = {Wiley}, address = {Weinheim}, issn = {1462-2920}, doi = {10.1111/1462-2920.14607}, year = {2019}, language = {en} } @article{FrotscherKochStaat2015, author = {Frotscher, Ralf and Koch, Jan-Peter and Staat, Manfred}, title = {Computational investigation of drug action on human-induced stem cell derived cardiomyocytes}, series = {Journal of biomechanical engineering}, volume = {Vol. 137}, journal = {Journal of biomechanical engineering}, number = {iss. 7}, publisher = {ASME}, address = {New York}, issn = {1528-8951 (E-Journal); 0148-0731 (Print)}, doi = {10.1115/1.4030173}, pages = {071002-1 -- 071002-7}, year = {2015}, language = {en} } @article{FerreinSteinbauerMcPhillipsetal.2009, author = {Ferrein, Alexander and Steinbauer, Gerald and McPhillips, Graeme and Niem{\"u}ller, Tim and Potgieter, Anet}, title = {Team Zadeat 2009 : team report}, volume = {6}, pages = {1}, year = {2009}, language = {en} } @inproceedings{KronhardtAlexopoulosReisseletal.2015, author = {Kronhardt, Valentina and Alexopoulos, Spiros and Reißel, Martin and Latzke, Markus and Rendon, C. and Sattler, Johannes Christoph and Herrmann, Ulf}, title = {Simulation of operational management for the Solar Thermal Test and Demonstration Power Plant J{\"u}lich using optimized control strategies of the storage system}, series = {Energy procedia}, booktitle = {Energy procedia}, issn = {1876-6102}, pages = {1 -- 6}, year = {2015}, language = {en} } @article{LeingartnerMaurerFerreinetal.2016, author = {Leingartner, Max and Maurer, Johannes and Ferrein, Alexander and Steinbauer, Gerald}, title = {Evaluation of Sensors and Mapping Approaches for Disasters in Tunnels}, series = {Journal of Field Robotics}, volume = {33}, journal = {Journal of Field Robotics}, number = {8}, publisher = {Wiley-VCH}, address = {Weinheim}, issn = {1556-4967}, doi = {10.1002/rob.21611}, pages = {1037 -- 1057}, year = {2016}, abstract = {Ground or aerial robots equipped with advanced sensing technologies, such as three-dimensional laser scanners and advanced mapping algorithms, are deemed useful as a supporting technology for first responders. A great deal of excellent research in the field exists, but practical applications at real disaster sites are scarce. Many projects concentrate on equipping robots with advanced capabilities, such as autonomous exploration or object manipulation. In spite of this, realistic application areas for such robots are limited to teleoperated reconnaissance or search. In this paper, we investigate how well state-of-the-art and off-the-shelf components and algorithms are suited for reconnaissance in current disaster-relief scenarios. The basic idea is to make use of some of the most common sensors and deploy some widely used algorithms in a disaster situation, and to evaluate how well the components work for these scenarios. We acquired the sensor data from two field experiments, one from a disaster-relief operation in a motorway tunnel, and one from a mapping experiment in a partly closed down motorway tunnel. Based on these data, which we make publicly available, we evaluate state-of-the-art and off-the-shelf mapping approaches. In our analysis, we integrate opinions and replies from first responders as well as from some algorithm developers on the usefulness of the data and the limitations of the deployed approaches, respectively. We discuss the lessons we learned during the two missions. These lessons are interesting for the community working in similar areas of urban search and rescue, particularly reconnaissance and search.}, language = {en} } @inproceedings{FingerGoettenBraunetal.2019, author = {Finger, Felix and G{\"o}tten, Falk and Braun, Carsten and Bil, Cees}, title = {Mass, Primary Energy, and Cost - The Impact of Optimization Objectives on the Initial Sizing of Hybrid-Electric General Aviation Aircraft}, series = {Deutscher Luft- und Raumfahrtkongress 2019, DLRK 2019. Darmstadt, Germany}, booktitle = {Deutscher Luft- und Raumfahrtkongress 2019, DLRK 2019. Darmstadt, Germany}, doi = {10.25967/490012}, pages = {1 -- 17}, year = {2019}, language = {en} } @article{Staat1993, author = {Staat, Manfred}, title = {Failure probabilities of the primary circuit pressure boundary of an HTR-Module for process heat generation under accident conditions for different failure modes}, series = {Nuclear Engineering and Design. 144 (1993), H. 1}, journal = {Nuclear Engineering and Design. 144 (1993), H. 1}, isbn = {0029-5493}, pages = {53 -- 67}, year = {1993}, language = {en} } @inproceedings{Eggert2019, author = {Eggert, Mathias}, title = {Understanding the acceptance of smart home-based insurances}, series = {Proceedings of the 27th European Conference on Information Systems (ECIS), Stockholm \& Uppsala, Sweden, June 8-14, 2019}, booktitle = {Proceedings of the 27th European Conference on Information Systems (ECIS), Stockholm \& Uppsala, Sweden, June 8-14, 2019}, isbn = {978-1-7336325-0-8}, pages = {1 -- 15}, year = {2019}, language = {en} } @article{GoettscheSchwarzerRoetheretal.2009, author = {G{\"o}ttsche, Joachim and Schwarzer, Klemens and R{\"o}ther, S. and Jellinghaus, Sabine}, title = {Efficient daylighting, heating and shading with rooflight heliostats}, series = {Conference Internationale Energie Solaire et Batiment}, journal = {Conference Internationale Energie Solaire et Batiment}, publisher = {EPFL}, address = {Lausanne}, pages = {243 -- 248}, year = {2009}, language = {en} } @inproceedings{BaaderReiswichBartschetal.2018, author = {Baader, Fabian and Reiswich, M. and Bartsch, M. and Keller, D. and Tiede, E. and Keck, G. and Demircian, A. and Friedrich, M. and Dachwald, Bernd and Sch{\"u}ller, K. and Lehmann, R. and Chojetzki, R. and Durand, C. and Rapp, L. and Kowalski, Julia and F{\"o}rstner, R.}, title = {VIPER - Student research on extraterrestrical ice penetration technology}, series = {Proceedings of the 2nd Symposium on Space Educational Activities}, booktitle = {Proceedings of the 2nd Symposium on Space Educational Activities}, pages = {1 -- 6}, year = {2018}, abstract = {Recent analysis of scientific data from Cassini and earth-based observations gave evidence for a global ocean under a surrounding solid ice shell on Saturn's moon Enceladus. Images of Enceladus' South Pole showed several fissures in the ice shell with plumes constantly exhausting frozen water particles, building up the E-Ring, one of the outer rings of Saturn. In this southern region of Enceladus, the ice shell is considered to be as thin as 2 km, about an order of magnitude thinner than on the rest of the moon. Under the ice shell, there is a global ocean consisting of liquid water. Scientists are discussing different approaches the possibilities of taking samples of water, i.e. by melting through the ice using a melting probe. FH Aachen UAS developed a prototype of maneuverable melting probe which can navigate through the ice that has already been tested successfully in a terrestrial environment. This means no atmosphere and or ambient pressure, low ice temperatures of around 100 to 150K (near the South Pole) and a very low gravity of 0,114 m/s^2 or 1100 μg. Two of these influencing measures are about to be investigated at FH Aachen UAS in 2017, low ice temperature and low ambient pressure below the triple point of water. Low gravity cannot be easily simulated inside a large experiment chamber, though. Numerical simulations of the melting process at RWTH Aachen however are showing a gravity dependence of melting behavior. Considering this aspect, VIPER provides a link between large-scale experimental simulations at FH Aachen UAS and numerical simulations at RWTH Aachen. To analyze the melting process, about 90 seconds of experiment time in reduced gravity and low ambient pressure is provided by the REXUS rocket. In this time frame, the melting speed and contact force between ice and probes are measured, as well as heating power and a two-dimensional array of ice temperatures. Additionally, visual and infrared cameras are used to observe the melting process.}, language = {en} } @incollection{TranStaat2015, author = {Tran, Thanh Ngoc and Staat, Manfred}, title = {Uncertainty multimode failure and shakedown analysis of shells}, series = {Direct methods for limit and shakedown analysis of structures / eds. Paolo Fuschi ...}, booktitle = {Direct methods for limit and shakedown analysis of structures / eds. Paolo Fuschi ...}, publisher = {Springer}, address = {Cham}, isbn = {978-3-319-12927-3 (print) ; 978-3-319-12928-0 (online)}, doi = {10.1007/978-3-319-12928-0_14}, pages = {279 -- 298}, year = {2015}, abstract = {This paper presents a numerical procedure for reliability analysis of thin plates and shells with respect to plastic collapse or to inadaptation. The procedure involves a deterministic shakedown analysis for each probabilistic iteration, which is based on the upper bound approach and the use of the exact Ilyushin yield surface. Probabilistic shakedown analysis deals with uncertainties originated from the loads, material strength and thickness of the shell. Based on a direct definition of the limit state function, the calculation of the failure probability may be efficiently solved by using the First and Second Order Reliability Methods (FORM and SORM). The problem of reliability of structural systems (series systems) is handled by the application of a special technique which permits to find all the design points corresponding to all the failure modes. Studies show, in this case, that it improves considerably the FORM and SORM results.}, language = {en} } @inproceedings{SchifferFerreinLakemeyer2011, author = {Schiffer, Stefan and Ferrein, Alexander and Lakemeyer, Gerhard}, title = {Fuzzy representations and control for domestic service robots in Golog}, series = {Intelligent robotics and applications : 4th International conference, ICIRA 2011, Aachen, Germany, December 6-8, 2011, proceedings, part I. (Lecture notes in computer science ; 7102)}, booktitle = {Intelligent robotics and applications : 4th International conference, ICIRA 2011, Aachen, Germany, December 6-8, 2011, proceedings, part I. (Lecture notes in computer science ; 7102)}, isbn = {978-3-642-25486-4}, pages = {241 -- 250}, year = {2011}, language = {en} } @article{DachwaldSeboldt2005, author = {Dachwald, Bernd and Seboldt, Wolfgang}, title = {Multiple Near-Earth Asteroid Rendezvous and Sample Return Using First Generation Solar Sailcraft}, series = {Acta Astronautica. 57 (2005), H. 11}, journal = {Acta Astronautica. 57 (2005), H. 11}, isbn = {0094-5765}, pages = {864 -- 875}, year = {2005}, language = {en} } @inproceedings{AhmedSchlenkhoffBung2011, author = {Ahmed, H. and Schlenkhoff, A. and Bung, Daniel Bernhard}, title = {Hydrodynamic characteristics of vertical slotted wall breakwaters}, series = {Balance and uncertainty - water in a changing world : proceedings of the 34th IAHR world congress ; 33rd Hydrology and Water Resources Symposium ; 10th Conference on Hydraulics in Water Engineering ; 26 June - 1 July 2011, Brisbane, Australia}, booktitle = {Balance and uncertainty - water in a changing world : proceedings of the 34th IAHR world congress ; 33rd Hydrology and Water Resources Symposium ; 10th Conference on Hydraulics in Water Engineering ; 26 June - 1 July 2011, Brisbane, Australia}, organization = {International Association for Hydraulic Engineering and Research}, isbn = {978-0-85825-868-6}, pages = {1179 -- 1186}, year = {2011}, language = {en} } @inproceedings{SteuerDankertLeichtScholten2017, author = {Steuer-Dankert, Linda and Leicht-Scholten, Carmen}, title = {Innovation and Diversity : Integrating new perspectives into research associations}, series = {12th European Conference on Innovation and Entrepreneurship (ECIE 2017) : Paris, France, 21-22 September 2017}, booktitle = {12th European Conference on Innovation and Entrepreneurship (ECIE 2017) : Paris, France, 21-22 September 2017}, isbn = {978-1-911218-54-8}, pages = {767 -- 776}, year = {2017}, abstract = {The link between diversity and innovation is broadly discussed in the context of research and innovation processes. Many institutions and enterprises, specifically in commerce, have already tried to establish sustainable diversity management concepts, in order to increase the diversity of their workforce in addition to establishing a corporate culture of openness. Alongside the creation of a working place where different experiences and skills are valued equally, the entrepreneurial intention is to transfer diversity into economically relevant advantages. Taking into account the potential of diversity in research and innovation processes, the project "Diversity- and Innovation Management" was incorporated within a large interdisciplinary research Cluster. The project's purpose was to study the context between diversity and innovation in research associations and to later develop a customised management concept into an interdisciplinary research Cluster on integrative production technology with full integration. The challenge of such research associations lays in an organisational structure which is often described as being decentralised. Researchers coming from different academic disciplines, while having diverse habits, conduct research on large scientific issues and challenges. In addition, these researchers are socialised in different institutions and university chairs. Theses differences in leadership styles, business cultures and organisational strategies, follow into their research team work. Taking a closer look into the management of human resources suggests that decentral organised recruitment processes, as well as allocation of human resources, lead to a lacking overview in regard to missing competencies, perspectives and backgrounds in research networks. These circumstances are comparable to big corporate groups. While developing a management concept for research associations, these characteristics must be considered. To ensure this, the project follows a human-centred approach, which considers top-down, as well as bottom-up perspectives. This paper presents the applied mixed-method approach in the scientific issue described above. In the frame of the Cluster of Excellence "Integrative Production Technology for High-Wage Countries" research results based on quantitative, as well as qualitative studies, were presented as an application example. This paper provides a new perspective on the innovation and diversity context. Against the background of complex research organisations, the development approach of a management concept is particularly interesting.}, language = {en} } @incollection{DachwaldBoehnhardtBrojetal.2014, author = {Dachwald, Bernd and Boehnhardt, Herrmann and Broj, Ulrich and Geppert, Ulrich R. M. E. and Grundmann, Jan-Thimo and Seboldt, Wolfgang and Seefeldt, Patric and Spietz, Peter and Johnson, Les and K{\"u}hrt, Ekkehard and Mottola, Stefano and Macdonald, Malcolm and McInnes, Colin R. and Vasile, Massimiliano and Reinhard, Ruedeger}, title = {Gossamer roadmap technology reference study for a multiple NEO Rendezvous Mission}, series = {Advances in solar sailing}, booktitle = {Advances in solar sailing}, publisher = {Springer}, address = {Berlin [u.a.]}, isbn = {978-3-642-34906-5 (Print) ; 978-3-642-34907-2 (E-Book)}, pages = {211 -- 226}, year = {2014}, abstract = {A technology reference study for a multiple near-Earth object (NEO) rendezvous mission with solar sailcraft is currently carried out by the authors of this paper. The investigated mission builds on previous concepts, but adopts a strong micro-spacecraft philosophy based on the DLR/ESA Gossamer technology. The main scientific objective of the mission is to explore the diversity of NEOs. After direct interplanetary insertion, the solar sailcraft should—within less than 10 years—rendezvous three NEOs that are not only scientifically interesting, but also from the point of human spaceight and planetary defense. In this paper, the objectives of the study are outlined and a preliminary potential mission profile is presented.}, language = {en} } @article{Staat2004, author = {Staat, Manfred}, title = {Plastic collapse analysis of longitudinally flawed pipes and vessels}, series = {Nuclear Engineering and Design. 234 (2004), H. 1-3}, journal = {Nuclear Engineering and Design. 234 (2004), H. 1-3}, isbn = {0029-5493}, pages = {25 -- 43}, year = {2004}, language = {en} } @article{StaatVu2004, author = {Staat, Manfred and Vu, Duc-Khoi}, title = {An Algorithm for Shakedown Analysis for Materials with Temperature Dependent Yield Stress}, series = {Proceedings in Applied Mathematics and Mechanics (PAMM). 4 (2004), H. 1}, journal = {Proceedings in Applied Mathematics and Mechanics (PAMM). 4 (2004), H. 1}, isbn = {1617-7061}, pages = {231 -- 233}, year = {2004}, language = {en} } @article{Staat2005, author = {Staat, Manfred}, title = {Local and global collapse pressure of longitudinally flawed pipes and cylindrical vessels}, series = {International Journal of Pressure Vessels and Piping. 82 (2005), H. 3}, journal = {International Journal of Pressure Vessels and Piping. 82 (2005), H. 3}, isbn = {0308-0161}, pages = {217 -- 225}, year = {2005}, language = {en} } @article{PreissLinderWendtetal.2011, author = {Preiß, C. and Linder, Peter and Wendt, K. and Krystek, M. and Digel, Ilya and Gossmann, Matthias and Temiz Artmann, Ayseg{\"u}l and Porst, Dariusz and Kayser, Peter and Bassam, Rasha and Artmann, Gerhard}, title = {Engineering technology for plant physiology and plant stress research}, year = {2011}, abstract = {Plant physiology and plant stress: Plant physiology will be much more important for human mankind because of yield and cultivation limits of crops determined by their resistance to stress. To assess and counteract various stress factors it is necessary to conduct plant research to gain information and results on plant physiology.}, subject = {Pflanzenphysiologie}, language = {en} } @inproceedings{BurgethKleefeldZhangetal.2022, author = {Burgeth, Bernhard and Kleefeld, Andreas and Zhang, Eugene and Zhang, Yue}, title = {Towards Topological Analysis of Non-symmetric Tensor Fields via Complexification}, series = {Discrete Geometry and Mathematical Morphology}, booktitle = {Discrete Geometry and Mathematical Morphology}, editor = {Baudrier, {\´E}tienne and Naegel, Beno{\^i}t and Kr{\"a}henb{\"u}hl, Adrien and Tajine, Mohamed}, publisher = {Springer}, address = {Cham}, isbn = {978-3-031-19897-7}, doi = {10.1007/978-3-031-19897-7_5}, pages = {48 -- 59}, year = {2022}, abstract = {Fields of asymmetric tensors play an important role in many applications such as medical imaging (diffusion tensor magnetic resonance imaging), physics, and civil engineering (for example Cauchy-Green-deformation tensor, strain tensor with local rotations, etc.). However, such asymmetric tensors are usually symmetrized and then further processed. Using this procedure results in a loss of information. A new method for the processing of asymmetric tensor fields is proposed restricting our attention to tensors of second-order given by a 2x2 array or matrix with real entries. This is achieved by a transformation resulting in Hermitian matrices that have an eigendecomposition similar to symmetric matrices. With this new idea numerical results for real-world data arising from a deformation of an object by external forces are given. It is shown that the asymmetric part indeed contains valuable information.}, language = {en} } @article{CheenakulaGriebelMontagetal.2023, author = {Cheenakula, Dheeraja and Griebel, Kai and Montag, David and Gr{\"o}mping, Markus}, title = {Concept development of a mainstream deammonification and comparison with conventional process in terms of energy, performance and economical construction perspectives}, series = {Frontiers in Microbiology}, volume = {14}, journal = {Frontiers in Microbiology}, number = {11155235}, editor = {Huang, Xiaowu}, publisher = {Frontiers}, issn = {1664-302X}, doi = {10.3389/fmicb.2023.1155235}, pages = {1 -- 15}, year = {2023}, abstract = {Deammonification for nitrogen removal in municipal wastewater in temperate and cold climate zones is currently limited to the side stream of municipal wastewater treatment plants (MWWTP). This study developed a conceptual model of a mainstream deammonification plant, designed for 30,000 P.E., considering possible solutions corresponding to the challenging mainstream conditions in Germany. In addition, the energy-saving potential, nitrogen elimination performance and construction-related costs of mainstream deammonification were compared to a conventional plant model, having a single-stage activated sludge process with upstream denitrification. The results revealed that an additional treatment step by combining chemical precipitation and ultra-fine screening is advantageous prior the mainstream deammonification. Hereby chemical oxygen demand (COD) can be reduced by 80\% so that the COD:N ratio can be reduced from 12 to 2.5. Laboratory experiments testing mainstream conditions of temperature (8-20°C), pH (6-9) and COD:N ratio (1-6) showed an achievable volumetric nitrogen removal rate (VNRR) of at least 50 gN/(m3∙d) for various deammonifying sludges from side stream deammonification systems in the state of North Rhine-Westphalia, Germany, where m3 denotes reactor volume. Assuming a retained Norganic content of 0.0035 kgNorg./(P.E.∙d) from the daily loads of N at carbon removal stage and a VNRR of 50 gN/(m3∙d) under mainstream conditions, a resident-specific reactor volume of 0.115 m3/(P.E.) is required for mainstream deammonification. This is in the same order of magnitude as the conventional activated sludge process, i.e., 0.173 m3/(P.E.) for an MWWTP of size class of 4. The conventional plant model yielded a total specific electricity demand of 35 kWh/(P.E.∙a) for the operation of the whole MWWTP and an energy recovery potential of 15.8 kWh/(P.E.∙a) through anaerobic digestion. In contrast, the developed mainstream deammonification model plant would require only a 21.5 kWh/(P.E.∙a) energy demand and result in 24 kWh/(P.E.∙a) energy recovery potential, enabling the mainstream deammonification model plant to be self-sufficient. The retrofitting costs for the implementation of mainstream deammonification in existing conventional MWWTPs are nearly negligible as the existing units like activated sludge reactors, aerators and monitoring technology are reusable. However, the mainstream deammonification must meet the performance requirement of VNRR of about 50 gN/(m3∙d) in this case.}, language = {en} } @article{RuebbelkeVoegeleGrajewskietal.2022, author = {R{\"u}bbelke, Dirk and V{\"o}gele, Stefan and Grajewski, Matthias and Zobel, Luzy}, title = {Hydrogen-based steel production and global climate protection: An empirical analysis of the potential role of a European cross border adjustment mechanism}, series = {Journal of Cleaner Production}, volume = {380}, journal = {Journal of Cleaner Production}, number = {Part 2, Art. Nr.:135040}, publisher = {Elsevier}, issn = {0959-6526}, doi = {10.1016/j.jclepro.2022.135040}, year = {2022}, abstract = {The European Union's aim to become climate neutral by 2050 necessitates ambitious efforts to reduce carbon emissions. Large reductions can be attained particularly in energy intensive sectors like iron and steel. In order to prevent the relocation of such industries outside the EU in the course of tightening environmental regulations, the establishment of a climate club jointly with other large emitters and alternatively the unilateral implementation of an international cross-border carbon tax mechanism are proposed. This article focuses on the latter option choosing the steel sector as an example. In particular, we investigate the financial conditions under which a European cross border mechanism is capable to protect hydrogen-based steel production routes employed in Europe against more polluting competition from abroad. By using a floor price model, we assess the competitiveness of different steel production routes in selected countries. We evaluate the climate friendliness of steel production on the basis of specific GHG emissions. In addition, we utilize an input-output price model. It enables us to assess impacts of rising cost of steel production on commodities using steel as intermediates. Our results raise concerns that a cross-border tax mechanism will not suffice to bring about competitiveness of hydrogen-based steel production in Europe because the cost tends to remain higher than the cost of steel production in e.g. China. Steel is a classic example for a good used mainly as intermediate for other products. Therefore, a cross-border tax mechanism for steel will increase the price of products produced in the EU that require steel as an input. This can in turn adversely affect competitiveness of these sectors. Hence, the effects of higher steel costs on European exports should be borne in mind and could require the cross-border adjustment mechanism to also subsidize exports.}, language = {en} } @article{ThielMufflerTippkoetteretal.2015, author = {Thiel, Alexander and Muffler, Kai and Tippk{\"o}tter, Nils and Suck, Kirstin and Sohling, Ulrich and Hruschka, Steffen M. and Ulber, Roland}, title = {A novel integrated downstream processing approach to recover sinapic acid, phytic acid and proteins from rapeseed meal}, series = {Journal of Chemical Technology and Biotechnology}, volume = {90}, journal = {Journal of Chemical Technology and Biotechnology}, number = {11}, publisher = {Wiley}, address = {Weinheim}, doi = {10.1002/jctb.4664}, pages = {1999 -- 2006}, year = {2015}, abstract = {BACKGROUND Currently, several techniques exist for the downstream processing of protein, phytic acid and sinapic acid from rapeseed and rapeseed meal, but no technique has been developed to separate all of the components in one process. In this work, two new downstream processing strategies focusing on recovering sinapic acid, phytic acid and protein from rapeseed meal were established. RESULTS The sinapic acid content was enhanced by a factor of 4.5 with one method and 5.1 with the other. The isolation of sinapic acid was accomplished using a zeolite-based adsorbent with high adsorptive and optimal desorption characteristics. Phytic acid was isolated using the anion-exchange resin Purolite A200®. In addition, the processes resulted in two separated protein fractions. The ratios of globulin and albumin ratio to the total protein were 59.2\% and 40.1\%, respectively. The steps were then combined in two different ways: (a) a 'sequential process' using the zeolite and A200 in batch processes; and (b) a 'parallel process' using only A200 in a chromatographic system to separate all of the compounds. CONCLUSIONS It can be concluded that isolation of all three components was possible in both processes. These could enhance the added value of current processes using rapeseed meal as a protein source. © 2015 Society of Chemical Industry}, language = {en} } @article{AlKaidyTippkoetter2016, author = {Al-Kaidy, Huschyar and Tippk{\"o}tter, Nils}, title = {Superparamagnetic hydrophobic particles as shell material for digital microfluidic droplets and proof-of-principle reaction assessments with immobilized laccase}, series = {Engineering in Life Sciences}, volume = {16}, journal = {Engineering in Life Sciences}, number = {3}, publisher = {Wiley-VCH}, address = {Weinheim}, doi = {10.1002/elsc.201400124}, pages = {222 -- 230}, year = {2016}, abstract = {In the field of biotechnology and molecular biology, the use of small liquid volumes has significant advantages. In particular, screening and optimization runs with acceptable amounts of expensive and hardly available catalysts, reagents, or biomolecules are feasible with microfluidic technologies. The presented new microfluidic system is based on the inclusion of small liquid volumes by a protective shell of magnetizable microparticles. Hereby, discrete aqueous microreactor drops with volumes of 1-30 μL can be formed on a simple planar surface. A digital movement and manipulation of the microreactor is performed by overlapping magnetic forces. The magnetic forces are generated by an electrical coil matrix positioned below a glass plate. With the new platform technology, several discrete reaction compartments can be moved simultaneously on one surface. Due to the magnetic fields, the reactors can even be merged to initiate reactions by mixing or positioned above surface-immobilized catalysts and then opened by magnetic force. Comparative synthesis routes of the magnetizable shell particles and superhydrophobic glass slides including their performance and stability with the reaction platform are described. The influence of diffusive mass transport during the catalyzed reaction is discussed by evaluation finite element model of the microreactor. Furthermore, a first model dye reaction of the enzyme laccase has been established.}, language = {en} } @article{Ritz2000, author = {Ritz, Thomas}, title = {Information Channels}, series = {Information Technology. Nr. 52 (2000), H. 08. Mai 2000}, journal = {Information Technology. Nr. 52 (2000), H. 08. Mai 2000}, pages = {15 -- 15}, year = {2000}, language = {en} } @inproceedings{MahdiDerschSchmitzetal.2022, author = {Mahdi, Zahra and Dersch, J{\"u}rgen and Schmitz, Pascal and Dieckmann, Simon and Chico Caminos, Ricardo Alexander and Teixeira Boura, Cristiano Jos{\´e} and Herrmann, Ulf and Schwager, Christian and Schmitz, Mark and Gielen, Hans and Gedle, Yibekal and B{\"u}scher, Rauno}, title = {Technical assessment of Brayton cycle heat pumps for the integration in hybrid PV-CSP power plants}, series = {SOLARPACES 2020}, booktitle = {SOLARPACES 2020}, number = {2445 / 1}, publisher = {AIP conference proceedings / American Institute of Physics}, address = {Melville, NY}, isbn = {978-0-7354-4195-8}, issn = {1551-7616 (online)}, doi = {10.1063/5.0086269}, pages = {11 Seiten}, year = {2022}, abstract = {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).}, language = {en} } @inproceedings{BaumannTeixeiraBouraGoettscheetal.2010, author = {Baumann, T. and Teixeira Boura, Cristiano Jos{\´e} and G{\"o}ttsche, Joachim and Hoffschmidt, Bernhard and O'Connell, B. and Schmitz, S. and Zunft, S.}, title = {Air/Sand heat exchanger design and materials for solar thermal power plant applications}, series = {SolarPACES 2010 : the CSP Conference: electricity, fuels and clean water from concentrated solar energy ; 21 to 24 September 2010, Perpignan, France}, booktitle = {SolarPACES 2010 : the CSP Conference: electricity, fuels and clean water from concentrated solar energy ; 21 to 24 September 2010, Perpignan, France}, publisher = {Soc. OSC}, address = {Saint Maur}, pages = {146 -- 147}, year = {2010}, language = {en} } @article{EngelBayerHoltmannetal.2019, author = {Engel, Mareike and Bayer, Hendrik and Holtmann, Dirk and Tippk{\"o}tter, Nils and Ulber, Roland}, title = {Flavin secretion of Clostridium acetobutylicum in a bioelectrochemical system - Is an iron limitation involved?}, series = {Bioelectrochemistry}, journal = {Bioelectrochemistry}, number = {In Press, Accepted Manuscript}, publisher = {Elsevier}, address = {Amsterdam}, issn = {1567-5394}, doi = {10.1016/j.bioelechem.2019.05.014}, year = {2019}, language = {en} } @inproceedings{LopesBungLeandroetal.2015, author = {Lopes, Pedro and Bung, Daniel Bernhard and Leandro, Jorge and Carvalho, Rita F.}, title = {The effect of cross-waves in physical stepped spillway models}, series = {E-proceedings of the 36th IAHR World Congress ; 28 June - 3 July, 2015, The Hague, the Netherlands}, booktitle = {E-proceedings of the 36th IAHR World Congress ; 28 June - 3 July, 2015, The Hague, the Netherlands}, organization = {International Association for Hydro-Environment Engineering and Research}, pages = {1 -- 9}, year = {2015}, language = {en} } @misc{TippkoetterUlber2009, author = {Tippk{\"o}tter, Nils and Ulber, Roland}, title = {Eine magnetische horizontale Wirbelschicht f{\"u}r die Durchmischung und R{\"u}ckhaltung von magnetisierbaren Mikropartikeln im Durchfluss}, series = {Chemie Ingenieur Technik}, volume = {81}, journal = {Chemie Ingenieur Technik}, number = {8}, publisher = {Wiley-VCH}, address = {Weinheim}, issn = {0009-286X}, doi = {10.1002/cite.200950076}, pages = {1168}, year = {2009}, abstract = {Magnetisierbare Partikel als Tr{\"a}ger von Katalysatoren k{\"o}nnen durch Anlegen eines magnetisches Feldes einfach und schnell abgetrennt werden. Die Wiedergewinnung von wertvollen Enzymen unter geringem Energie- und Materialeinsatz der magnetischen Abtrennung er{\"o}ffnet einen Wettbewerbsvorteil f{\"u}r Produktionsprozesse. Die Abtrennung von magnetisierbaren Partikeln vom {\"U}berstand wird {\"u}blicherweise entweder durch Anlegen eines {\"a}ußeren Magnetfelds und der resultierenden Ablagerung der Partikel an den Reaktorw{\"a}nden oder durch Hochgradientenmagnetseparation (HGMS)durchgef{\"u}hrt. Beide Verfahren resultieren meist in der Bildung eines Filterkuchens aus Magnetpartikeln und den Feststoffen des Reaktionsmediums. Das magnetische horizontale Wirbelbett erm{\"o}glicht simultan eine kontinuierliche Reaktionsf{\"u}hrung und die R{\"u}ckhaltung der Partikel im Durchfluss. Die Partikelsuspension fließt durch einen Rohrreaktor, der in einem Magnetfeld mit wechselnden Feldgradienten eingebracht ist. Die {\"A}nderung des Magnetfeldgradienten erfolgt entgegen der Str{\"o}mungsrichtung der Reaktionsl{\"o}sung. Durch alternierende Feldmaxima an den beiden Seiten des Reaktors werden die magnetisierbaren Partikel zu dessen W{\"a}nden gezogen. Bei Umkehrung des Feldes wandern die Partikel an die gegen{\"u}berliegende Reaktorwand. Durch Wahl einer geeigneten Wechselfrequenz kann eine kontinuierliche Durchmischung und R{\"u}ckhaltung der Mikropartikel im durchstr{\"o}mten Rohr erreicht werden. Somit k{\"o}nnen Immobilisierungsreaktionen und Biotransformationen mit den Partikelsystemen im Durchfluss durchgef{\"u}hrt werden.}, language = {en} } @article{RensVarzinczakMeyeretal.2010, author = {Rens, Gavin and Varzinczak, Ivan and Meyer, Thomas and Ferrein, Alexander}, title = {A Logic for Reasoning about Actions and Explicit Observations}, series = {AI 2010: Advances in Artificial Intelligence 23rd Australasian Joint Conference, Adelaide, Australia, December 7-10, 2010. Proceedings}, journal = {AI 2010: Advances in Artificial Intelligence 23rd Australasian Joint Conference, Adelaide, Australia, December 7-10, 2010. Proceedings}, publisher = {Springer}, address = {Berlin}, isbn = {978-3-642-17431-5}, pages = {395 -- 404}, year = {2010}, language = {en} } @article{HeuermannSchiek1995, author = {Heuermann, Holger and Schiek, Burkhard}, title = {The double-LNN Calibration technique for scattering parameter measurements of microstrip devices}, series = {Conference proceedings}, journal = {Conference proceedings}, publisher = {NEXUS House}, address = {Kent}, pages = {343 -- 347}, year = {1995}, language = {en} } @inproceedings{BallmannRaatschenStaat1985, author = {Ballmann, J. and Raatschen, Hans-J{\"u}rgen and Staat, Manfred}, title = {High stress intensities in focussing zones of waves}, doi = {10.1016/B978-0-444-42520-1.50015-3}, year = {1985}, abstract = {The propagation of mechanical waves in plates of isotropic elastic material is investigated. After a short introduction to the understanding of focussing of stress waves in a plate with a curved boundary the method of characteristics is applied to a plate of hyperelastic material. Using this method the propagation of acceleration waves is discussed. Based on this a numerical difference scheme is developed for solving initial-boundary-value problems and applied to two examples: propagation of a point disturbance in a homogeneously finitely strained non-linear elastic plate and geometrical focussing in al linear elastic plate.}, subject = {Technische Mechanik}, language = {en} } @article{KronhardtAlexopoulosReisseletal.2014, author = {Kronhardt, Valentina and Alexopoulos, Spiros and Reißel, Martin and Sattler, Johannes Christoph and Hoffschmidt, Bernhard and H{\"a}nel, Matthias and Doerbeck, Till}, title = {High-temperature thermal storage system for solar tower power plants with open-volumetric air receiver simulation and energy balancing of a discretized model}, series = {Energy procedia}, volume = {49}, journal = {Energy procedia}, publisher = {Elsevier}, address = {Amsterdam}, issn = {1876-6102 (E-Journal) ; 1876-6102 (Print)}, doi = {10.1016/j.egypro.2014.03.094}, pages = {870 -- 877}, year = {2014}, abstract = {This paper describes the modeling of a high-temperature storage system for an existing solar tower power plant with open volumetric receiver technology, which uses air as heat transfer medium (HTF). The storage system model has been developed in the simulation environment Matlab/Simulink®. The storage type under investigation is a packed bed thermal energy storage system which has the characteristics of a regenerator. Thermal energy can be stored and discharged as required via the HTF air. The air mass flow distribution is controlled by valves, and the mass flow by two blowers. The thermal storage operation strategy has a direct and significant impact on the energetic and economic efficiency of the solar tower power plants.}, language = {en} } @article{Laack2013, author = {Laack, Walter van}, title = {Why natural constants are as they are}, series = {British journal of arts and social sciences}, volume = {Vol. 15}, journal = {British journal of arts and social sciences}, number = {Nr. 2}, publisher = {BritishJournal Publ. Inc}, address = {London}, issn = {2046-9578 (E-Journal)}, pages = {198 -- 203}, year = {2013}, language = {en} } @article{FerreinNiemuellerSteinbauer2010, author = {Ferrein, Alexander and Niem{\"u}ller, Tim and Steinbauer, Gerald}, title = {Team Zadeat 2010 : application for participation}, pages = {5 Seiten}, year = {2010}, language = {en} } @article{Heuermann1996, author = {Heuermann, Holger}, title = {Sure Methods of On-Wafer Scattering Parameter Measurements with Self-Calibration Procedures}, pages = {136 -- 145}, year = {1996}, language = {en} } @inproceedings{MertensPuetzBrauneretal.2021, author = {Mertens, Alexander and P{\"u}tz, Sebastian and Brauner, Philipp and Brillowski, Florian Sascha and Buczak, Nadine and Dammers, Hannah and van Dyck, Marc and Kong, Iris and K{\"o}nigs, Peter and Kortomeikel, Frauke Carole and Rodemann, Niklas and Schaar, Anne Kathrin and Steuer-Dankert, Linda and Wlecke, Shari and Gries, Thomas and Leicht-Scholten, Carmen and Nagel, Saskia K. and Piller, Frank Thomas and Schuh, G{\"u}nther and Ziefle, Martina and Nitsch, Verena}, title = {Human digital shadow: Data-based modeling of users and usage in the internet of production}, series = {14th Conference Human System Interaction Conference Proceedings}, booktitle = {14th Conference Human System Interaction Conference Proceedings}, publisher = {IEEE}, doi = {10.1109/HSI52170.2021.9538729}, pages = {1 -- 8}, year = {2021}, abstract = {Digital Shadows as the aggregation, linkage and abstraction of data relating to physical objects are a central vision for the future of production. However, the majority of current research takes a technocentric approach, in which the human actors in production play a minor role. Here, the authors present an alternative anthropocentric perspective that highlights the potential and main challenges of extending the concept of Digital Shadows to humans. Following future research methodology, three prospections that illustrate use cases for Human Digital Shadows across organizational and hierarchical levels are developed: human-robot collaboration for manual work, decision support and work organization, as well as human resource management. Potentials and challenges are identified using separate SWOT analyses for the three prospections and common themes are emphasized in a concluding discussion.}, language = {en} } @inproceedings{PeloniDachwaldCeriotti2017, author = {Peloni, Alessandro and Dachwald, Bernd and Ceriotti, Matteo}, title = {Multiple NEA rendezvous mission: Solar sailing options}, series = {Fourth International Symposium on Solar Sailing}, booktitle = {Fourth International Symposium on Solar Sailing}, pages = {1 -- 11}, year = {2017}, abstract = {The scientific interest in near-Earth asteroids (NEAs) and the classification of some of those as potentially hazardous asteroid for the Earth stipulated the interest in NEA exploration. Close-up observations of these objects will increase drastically our knowledge about the overall NEA population. For this reason, a multiple NEA rendezvous mission through solar sailing is investigated, taking advantage of the propellantless nature of this groundbreaking propulsion technology. Considering a spacecraft based on the DLR/ESA Gossamer technology, this work focuses on the search of possible sequences of NEA encounters. The effectiveness of this approach is demonstrated through a number of fully-optimized trajectories. The results show that it is possible to visit five NEAs within 10 years with near-term solar-sail technology. Moreover, a study on a reduced NEA database demonstrates the reliability of the approach used, showing that 58\% of the sequences found with an approximated trajectory model can be converted into real solar-sail trajectories. Lastly, this second study shows the effectiveness of the proposed automatic optimization algorithm, which is able to find solutions for a large number of mission scenarios without any input required from the user.}, language = {en} } @article{OertelBung2015, author = {Oertel, Mario and Bung, Daniel Bernhard}, title = {Stability and scour development of bed material on crossbar block ramps}, series = {International journal of sediment research}, volume = {30}, journal = {International journal of sediment research}, number = {4}, publisher = {Elsevier}, address = {Amsterdam}, issn = {1001-6279}, doi = {10.1016/j.ijsrc.2014.12.003}, pages = {344 -- 350}, year = {2015}, abstract = {Block ramps are ecologically oriented drop structures with adequate energy dissipation and partially moderate flow velocities. A special case is given with crossbar block ramps, where the upstream and downstream level difference is reduced by a series of basins. To prevent the total structure from failing, the stability of single boulders within the crossbars and the bed material in between must be guaranteed. The present paper addresses the stability of bed material and scour development for various flow regimes. Any bed material erosion may affect the stability of the crossbar boulders, which in turn can result in major damages of the ramp. Therefore new design approaches are developed to choose an appropriate bed material size and to avoid failures of crossbar block ramp structures.}, language = {en} } @book{WolfFoltzKillich2000, author = {Wolf, Martin R. and Foltz, Christian and Killich, S.}, title = {K3 User Guide}, publisher = {RWTH}, address = {Aachen}, pages = {1 -- 13}, year = {2000}, language = {en} } @article{HoffmannRohrbachUhletal.2022, author = {Hoffmann, Andreas and Rohrbach, Felix and Uhl, Matthias and Ceblin, Maximilian and Bauer, Thomas and Mallah, Marcel and Jacob, Timo and Heuermann, Holger and Kuehne, Alexander J. C.}, title = {Atmospheric pressure plasma-jet treatment of polyacrylonitrile-nonwovens—Stabilization and roll-to-roll processing}, series = {Journal of Applied Polymer Science}, volume = {139}, journal = {Journal of Applied Polymer Science}, number = {37}, publisher = {Wiley}, issn = {0021-8995 (Print)}, doi = {10.1002/app.52887}, pages = {1 -- 9}, year = {2022}, abstract = {Carbon nanofiber nonwovens represent a powerful class of materials with prospective application in filtration technology or as electrodes with high surface area in batteries, fuel cells, and supercapacitors. While new precursor-to-carbon conversion processes have been explored to overcome productivity restrictions for carbon fiber tows, alternatives for the two-step thermal conversion of polyacrylonitrile precursors into carbon fiber nonwovens are absent. In this work, we develop a continuous roll-to-roll stabilization process using an atmospheric pressure microwave plasma jet. We explore the influence of various plasma-jet parameters on the morphology of the nonwoven and compare the stabilized nonwoven to thermally stabilized samples using scanning electron microscopy, differential scanning calorimetry, and infrared spectroscopy. We show that stabilization with a non-equilibrium plasma-jet can be twice as productive as the conventional thermal stabilization in a convection furnace, while producing electrodes of comparable electrochemical performance.}, language = {en} }