@inproceedings{GoettenFingerHavermannetal.2020, author = {G{\"o}tten, Falk and Finger, Felix and Havermann, Marc and Braun, Carsten and Marino, Matthew and Bil, Cees}, title = {Full Configuration Drag Estimation of Small-to-Medium Range UAVs and its Impact on Initial Sizing Optimization}, series = {CEAS Aeronautical Journal}, volume = {12}, booktitle = {CEAS Aeronautical Journal}, publisher = {Springer}, address = {Wien}, issn = {1869-5590}, doi = {10.1007/s13272-021-00522-w}, pages = {589 -- 603}, year = {2020}, abstract = {The paper presents the derivation of a new equivalent skin friction coefficient for estimating the parasitic drag of short-to-medium range fixed-wing unmanned aircraft. The new coefficient is derived from an aerodynamic analysis of ten different unmanned aircraft used on surveillance, reconnaissance, and search and rescue missions. The aircraft are simulated using a validated unsteady Reynolds-averaged Navier Stokes approach. The UAV's parasitic drag is significantly influenced by the presence of miscellaneous components like fixed landing gears or electro-optical sensor turrets. These components are responsible for almost half of an unmanned aircraft's total parasitic drag. The new equivalent skin friction coefficient accounts for these effects and is significantly higher compared to other aircraft categories. It is used to initially size an unmanned aircraft for a typical reconnaissance mission. The improved parasitic drag estimation yields a much heavier unmanned aircraft when compared to the sizing results using available drag data of manned aircraft.}, language = {en} } @inproceedings{SildatkeKarwanniKraftetal.2020, author = {Sildatke, Michael and Karwanni, Hendrik and Kraft, Bodo and Schmidts, Oliver and Z{\"u}ndorf, Albert}, title = {Automated Software Quality Monitoring in Research Collaboration Projects}, series = {ICSEW'20: Proceedings of the IEEE/ACM 42nd International Conference on Software Engineering Workshops}, booktitle = {ICSEW'20: Proceedings of the IEEE/ACM 42nd International Conference on Software Engineering Workshops}, publisher = {IEEE}, address = {New York, NY}, doi = {10.1145/3387940.3391478}, pages = {603 -- 610}, year = {2020}, abstract = {In collaborative research projects, both researchers and practitioners work together solving business-critical challenges. These projects often deal with ETL processes, in which humans extract information from non-machine-readable documents by hand. AI-based machine learning models can help to solve this problem. Since machine learning approaches are not deterministic, their quality of output may decrease over time. This fact leads to an overall quality loss of the application which embeds machine learning models. Hence, the software qualities in development and production may differ. Machine learning models are black boxes. That makes practitioners skeptical and increases the inhibition threshold for early productive use of research prototypes. Continuous monitoring of software quality in production offers an early response capability on quality loss and encourages the use of machine learning approaches. Furthermore, experts have to ensure that they integrate possible new inputs into the model training as quickly as possible. In this paper, we introduce an architecture pattern with a reference implementation that extends the concept of Metrics Driven Research Collaboration with an automated software quality monitoring in productive use and a possibility to auto-generate new test data coming from processed documents in production. Through automated monitoring of the software quality and auto-generated test data, this approach ensures that the software quality meets and keeps requested thresholds in productive use, even during further continuous deployment and changing input data.}, language = {en} } @book{YoshinobuSchoening2020, author = {Yoshinobu, Tatsuo and Sch{\"o}ning, Michael Josef}, title = {Light-addressing and chemical imaging technologies for electrochemical sensing}, editor = {Yoshinobu, Tatsuo and Sch{\"o}ning, Michael Josef}, publisher = {MDPI}, address = {Basel}, isbn = {978-3-03943-029-1}, doi = {10.3390/books978-3-03943-029-1}, pages = {122 Pages}, year = {2020}, language = {en} } @inproceedings{IomdinaKiselevaKotliaretal.2020, author = {Iomdina, Elena N. and Kiseleva, Anna A. and Kotliar, Konstantin and Luzhnov, Petr V.}, title = {Quantification of Choroidal Blood Flow Using the OCT-A System Based on Voxel Scan Processing}, series = {Proceedings of the International Conference on Biomedical Innovations and Applications- BIA 2020}, booktitle = {Proceedings of the International Conference on Biomedical Innovations and Applications- BIA 2020}, publisher = {IEEE}, address = {New York, NY}, isbn = {978-1-7281-7073-2}, doi = {10.1109/BIA50171.2020.9244511}, pages = {41 -- 44}, year = {2020}, abstract = {The paper presents a method for the quantitative assessment of choroidal blood flow using an OCT-A system. The developed technique for processing of OCT-A scans is divided into two stages. At the first stage, the identification of the boundaries in the selected portion was performed. At the second stage, each pixel mark on the selected layer was represented as a volume unit, a voxel, which characterizes the region of moving blood. Three geometric shapes were considered to represent the voxel. On the example of one OCT-A scan, this work presents a quantitative assessment of the blood flow index. A possible modification of two-stage algorithm based on voxel scan processing is presented.}, language = {en} } @inproceedings{FrantzBinderBuschetal.2020, author = {Frantz, Cathy and Binder, Matthias and Busch, Konrad and Ebert, Miriam and Heinrich, Andreas and Kaczmarkiewicz, Nadine and Schl{\"o}gl-Knothe, B{\"a}rbel and Kunze, Tobias and Schuhbauer, Christian and Stetka, Markus and Schwager, Christian and Spiegel, Michael and Teixeira Boura, Cristiano Jos{\´e} and Bauer, Thomas and Bonk, Alexander and Eisen, Stefan and Funck, Bernhard}, title = {Basic Engineering of a High Performance Molten Salt Tower Receiver System}, series = {AIP Conference Proceedings}, booktitle = {AIP Conference Proceedings}, doi = {10.1063/5.0085895}, pages = {1 -- 10}, year = {2020}, abstract = {The production of dispatchable renewable energy will be one of the most important key factors of the future energy supply. Concentrated solar power (CSP) plants operated with molten salt as heat transfer and storage media are one opportunity to meet this challenge. Due to the high concentration factor of the solar tower technology the maximum process temperature can be further increased which ultimately decreases the levelized costs of electricity of the technology (LCOE). The development of an improved tubular molten salt receiver for the next generation of molten salt solar tower plants is the aim of this work. The receiver is designed for a receiver outlet temperature up to 600 °C. Together with a complete molten salt system, the receiver will be integrated into the Multi-Focus-Tower (MFT) in J{\"u}lich (Germany). The paper describes the basic engineering of the receiver, the molten salt tower system and a laboratory corrosion setup.}, language = {en} } @article{Stulpe2020, author = {Stulpe, Werner}, title = {Pairwise coexistence of effects versus coexistence}, series = {Journal of Physics: Conference Series}, volume = {1638}, journal = {Journal of Physics: Conference Series}, number = {012004}, publisher = {IOP}, address = {Bristol}, issn = {1742-6596}, doi = {10.1088/1742-6596/1638/1/012004}, pages = {1 -- 21}, year = {2020}, language = {en} } @inproceedings{MarinkovicButenweg2020, author = {Marinkovic, Marko and Butenweg, Christoph}, title = {Seismic behaviour of RC frames with uncoupled masonry infills having two storeys or two bays}, series = {Brick and Block Masonry - From Historical to Sustainable Masonry. Proceedings of the 17th International Brick/Block Masonry Conference}, booktitle = {Brick and Block Masonry - From Historical to Sustainable Masonry. Proceedings of the 17th International Brick/Block Masonry Conference}, publisher = {CRC Press}, address = {London}, doi = {10.1201/9781003098508-72}, pages = {1 -- 7}, year = {2020}, abstract = {Reinforced concrete (RC) structures with masonry infills are widely used for several types of buildings all over the world. However, it is well known that traditional masonry infills constructed with rigid contact to the surrounding RC frame performed rather poor in past earthquakes. Masonry infills showed severe in-plane damages and failed in many cases under out-of-plane seismic loading. As the undesired interactions between frames and infills changes the load transfer on building level, complete collapses of buildings were observed. A possible solution is uncoupling of masonry infills to the frame to reduce the infill contribution activated by the frame deformation under horizontal loading. The paper presents numerical simulations on RC frames equipped with the innovative decoupling system INODIS. The system was developed within the European project INSYSME and allows an effective uncoupling of frame and infill. The simulations are carried out with a micro-modelling approach, which is able to predict the complex nonlinear behaviour resulting from the different materials and their interaction. Each brick is modelled individually and connected taking into account nonlinearity of a brick mortar interface. The calibration of the model is based on small specimen tests and experimental results for one bay one storey frame are used for the validation. The validated model is further used for parametric studies on two storey and two bay infilled frames. The response and change of the structural stiffness are analysed and compared to the traditionally infilled frame. The results confirm the effectiveness of the INODIS system with less damage and relatively low contribution of the infill at high drift levels. In contrast to the uncoupled system configurations, traditionally infilled frames experienced brittle failure at rather low drift levels.}, language = {en} } @book{ButenwegHoffmeisterHoltschoppenetal.2020, author = {Butenweg, Christoph and Hoffmeister, Benno and Holtschoppen, Britta and Klinkel, Sven and Rosin, Julia and Schmitt, Timo}, title = {Seismic design of industrial facilities 2020: proceedings of the 2nd International Conference on Seismic Design of Industrial Facilities (SeDIF-Conference)}, publisher = {Apprimus Verlag}, address = {Aachen}, isbn = {978-3-86359-729-0}, pages = {524 Seiten}, year = {2020}, language = {en} } @inproceedings{MarkinkovicButenwegPaveseetal.2020, author = {Markinkovic, Marko and Butenweg, Christoph and Pavese, A. and Lanese, I. and Hoffmeister, B. and Pinkawa, M. and Vulcu, C. and Bursi, O. and Nardin, C. and Paolacci, F. and Quinci, G. and Fragiadakis, M. and Weber, F. and Huber, P. and Renault, P. and G{\"u}ndel, M. and Dyke, S. and Ciucci, M. and Marino, A.}, title = {Investigation of the seismic behaviour of structural and nonstructural components in industrial facilities by means of shaking table tests}, series = {Seismic design of industrial facilities 2020}, booktitle = {Seismic design of industrial facilities 2020}, publisher = {Apprimus Verlag}, address = {Aachen}, isbn = {978-3-86359-729-0}, pages = {159 -- 172}, year = {2020}, language = {en} } @inproceedings{CacciatoreButenweg2020, author = {Cacciatore, Pamela and Butenweg, Christoph}, title = {Seismic safety of cylindrical granular material steel silos under seismic loading}, series = {Seismic design of industrial facilities 2020}, booktitle = {Seismic design of industrial facilities 2020}, publisher = {Apprimus Verlag}, address = {Aachen}, isbn = {978-3-86359-729-0}, pages = {231 -- 244}, year = {2020}, language = {en} } @inproceedings{MichelRosinButenwegetal.2020, author = {Michel, Philipp and Rosin, Julia and Butenweg, Christoph and Klinkel, Sven}, title = {Soil-dependent earthquake spectra in the analysis of liquid-storage-tanks on compliant soil}, series = {Seismic design of industrial facilities 2020}, booktitle = {Seismic design of industrial facilities 2020}, publisher = {Apprimus Verlag}, address = {Aachen}, isbn = {978-3-86359-729-0}, pages = {245 -- 254}, year = {2020}, abstract = {A further development of the Added-Mass-Method allows the combined representation of the effects of both soil-structure-interaction and fluid-structure interaction on a liquid-filled-tank in one model. This results in a practical method for describing the dynamic fluid pressure on the tank shell during joint movement. The fluid pressure is calculated on the basis of the tank's eigenform and the earthquake acceleration and represented by additional masses on the shell. The bearing on compliant ground is represented by replacement springs, which are calculated dependent on the local soil composition. The influence of the shear modulus of the compliant soil is clearly visible in the pressure curves and the stress distribution in the shell. The acceleration spectra are also dependent on soil stiffness. According to Eurocode-8 the acceleration spectra are determined for fixed soil-classes, instead of calculating the accelerations for each site in direct dependence on the soil composition. This leads to unrealistic sudden changes in the system's response. Therefore, earthquake spectra are calculated for different soil models in direct dependence of the shear modulus. Thus, both the acceleration spectra and the replacement springs match the soil composition. This enables a reasonable and consistent calculation of the system response for the actual conditions at each site.}, language = {en} } @article{HueningBackes2020, author = {H{\"u}ning, Felix and Backes, Andreas}, title = {Direct observation of large Barkhausen jump in thin Vicalloy wires}, series = {IEEE Magnetics Letters}, volume = {11}, journal = {IEEE Magnetics Letters}, number = {Art. 2506504}, publisher = {IEEE}, address = {New York, NY}, isbn = {1949-307X}, doi = {10.1109/LMAG.2020.3046411}, pages = {1 -- 4}, year = {2020}, language = {en} } @article{GazdaMaurischat2020, author = {Gazda, Quentin and Maurischat, Andreas}, title = {Special functions and Gauss-Thakur sums in higher rank and dimension}, publisher = {De Gruyter}, address = {Berlin}, pages = {26 Seiten}, year = {2020}, language = {en} } @inproceedings{ChavezBermudezWollert2020, author = {Chavez Bermudez, Victor Francisco and Wollert, J{\"o}rg}, title = {Arduino based Framework for Rapid Application Development of a Generic IO-Link interface}, series = {Kommunikation und Bildverarbeitung in der Automation. Ausgew{\"a}hlte Beitr{\"a}ge der Jahreskolloquien KommA und BVAu 2018}, booktitle = {Kommunikation und Bildverarbeitung in der Automation. Ausgew{\"a}hlte Beitr{\"a}ge der Jahreskolloquien KommA und BVAu 2018}, publisher = {Springer Vieweg}, address = {Berlin}, isbn = {978-3-662-59895-5}, doi = {10.1007/978-3-662-59895-5_2}, pages = {21 -- 33}, year = {2020}, abstract = {The implementation of IO-Link in the automation industry has increased over the years. Its main advantage is it offers a digital point-to-point plugand-play interface for any type of device or application. This simplifies the communication between devices and increases productivity with its different features like self-parametrization and maintenance. However, its complete potential is not always used. The aim of this paper is to create an Arduino based framework for the development of generic IO-Link devices and increase its implementation for rapid prototyping. By generating the IO device description file (IODD) from a graphical user interface, and further customizable options for the device application, the end-user can intuitively develop generic IO-Link devices. The peculiarity of this framework relies on its simplicity and abstraction which allows to implement any sensor functionality and virtually connect any type of device to an IO-Link master. This work consists of the general overview of the framework, the technical background of its development and a proof of concept which demonstrates the workflow for its implementation.}, language = {en} } @inproceedings{KaschSchmidtEichleretal.2020, author = {Kasch, Susanne and Schmidt, Thomas and Eichler, Fabian and Thurn, Laura and Jahn, Simon and Bremen, Sebastian}, title = {Solution approaches and process concepts for powder bed-based melting of glass}, series = {Industrializing Additive Manufacturing. Proceedings of AMPA2020}, booktitle = {Industrializing Additive Manufacturing. Proceedings of AMPA2020}, publisher = {Springer}, address = {Cham}, isbn = {978-3-030-54333-4 (Print)}, doi = {10.1007/978-3-030-54334-1_7}, pages = {82 -- 95}, year = {2020}, abstract = {In the study, the process chain of additive manufacturing by means of powder bed fusion will be presented based on the material glass. In order to reliably process components additively, new concepts with different solutions were developed and investigated. Compared to established metallic materials, the properties of glass materials differ significantly. Therefore, the process control was adapted to the material glass in the investigations. With extensive parameter studies based on various glass powders such as borosilicate glass and quartz glass, scientifically proven results on powder bed fusion of glass are presented. Based on the determination of the particle properties with different methods, extensive investigations are made regarding the melting behavior of glass by means of laser beams. Furthermore, the experimental setup was steadily expanded. In addition to the integration of coaxial temperature measurement and regulation, preheating of the building platform is of major importance. This offers the possibility to perform 3D printing at the transformation temperatures of the glass materials. To improve the component's properties, the influence of a subsequent heat treatment was also investigated. The experience gained was incorporated into a new experimental system, which allows a much better exploration of the 3D printing of glass. Currently, studies are being conducted to improve surface texture, building accuracy, and geometrical capabilities using three-dimensional specimen. The contribution shows the development of research in the field of 3D printing of glass, gives an insight into the machine and process engineering as well as an outlook on the possibilities and applications.}, language = {en} } @inproceedings{AdamsLosekammCzupalla2020, author = {Adams, Moritz and Losekamm, Martin J. and Czupalla, Markus}, title = {Development of the Thermal Control System for the RadMap Telescope Experiment on the International Space Station}, series = {International Conference on Environmental Systems}, booktitle = {International Conference on Environmental Systems}, pages = {1 -- 10}, year = {2020}, language = {en} } @inproceedings{ThomaFisherBertrandetal.2020, author = {Thoma, Andreas and Fisher, Alex and Bertrand, Olivier and Braun, Carsten}, title = {Evaluation of possible flight strategies for close object evasion from bumblebee experiments}, series = {Living Machines 2020: Biomimetic and Biohybrid Systems}, booktitle = {Living Machines 2020: Biomimetic and Biohybrid Systems}, editor = {Vouloutsi, Vasiliki and Mura, Anna and Tauber, Falk and Speck, Thomas and Prescott, Tony J. and Verschure, Paul F. M. J.}, publisher = {Springer}, address = {Cham}, isbn = {978-3-030-64312-6}, doi = {10.1007/978-3-030-64313-3_34}, pages = {354 -- 365}, year = {2020}, language = {en} } @inproceedings{ThomaFisherBraun2020, author = {Thoma, Andreas and Fisher, Alex and Braun, Carsten}, title = {Improving the px4 avoid algorithm by bio-inspired flight strategies}, series = {DLRK2020 - „Luft- und Raumfahrt - Verantwortung in allen Dimensionen"}, booktitle = {DLRK2020 - „Luft- und Raumfahrt - Verantwortung in allen Dimensionen"}, doi = {10.25967/530183}, pages = {10 Seiten}, year = {2020}, language = {en} } @article{QuittmannAbelAlbrachtetal.2020, author = {Quittmann, Oliver J. and Abel, Thomas and Albracht, Kirsten and Meskemper, Joshua and Foitschik, Tina and Str{\"u}der, Heiko K.}, title = {Biomechanics of handcycling propulsion in a 30-min continuous load test at lactate threshold: Kinetics, kinematics, and muscular activity in able-bodied participants}, series = {European Journal of Applied Physiology}, journal = {European Journal of Applied Physiology}, number = {120}, publisher = {Springer}, address = {Heidelberg}, issn = {1439-6327}, doi = {10.1007/s00421-020-04373-x}, pages = {1403 -- 1415}, year = {2020}, abstract = {Purpose This study aims to investigate the biomechanics of handcycling during a continuous load trial (CLT) to assess the mechanisms underlying fatigue in upper body exercise. Methods Twelve able-bodied triathletes performed a 30-min CLT at a power output corresponding to lactate threshold in a racing recumbent handcycle mounted on a stationary ergometer. During the CLT, ratings of perceived exertion (RPE), tangential crank kinetics, 3D joint kinematics, and muscular activity of ten muscles of the upper extremity and trunk were examined using motion capturing and surface electromyography. Results During the CLT, spontaneously chosen cadence and RPE increased, whereas crank torque decreased. Rotational work was higher during the pull phase. Peripheral RPE was higher compared to central RPE. Joint range of motion decreased for elbow-flexion and radial-duction. Integrated EMG (iEMG) increased in the forearm flexors, forearm extensors, and M. deltoideus (Pars spinalis). An earlier onset of activation was found for M. deltoideus (Pars clavicularis), M. pectoralis major, M. rectus abdominis, M. biceps brachii, and the forearm flexors. Conclusion Fatigue-related alterations seem to apply analogously in handcycling and cycling. The most distal muscles are responsible for force transmission on the cranks and might thus suffer most from neuromuscular fatigue. The findings indicate that peripheral fatigue (at similar lactate values) is higher in handcycling compared to leg cycling, at least for inexperienced participants. An increase in cadence might delay peripheral fatigue by a reduced vascular occlusion. We assume that the gap between peripheral and central fatigue can be reduced by sport-specific endurance training.}, language = {en} } @inproceedings{PohleFroehlichDalitzRichteretal.2020, author = {Pohle-Fr{\"o}hlich, Regina and Dalitz, Christoph and Richter, Charlotte and Hahnen, Tobias and St{\"a}udle, Benjamin and Albracht, Kirsten}, title = {Estimation of muscle fascicle orientation in ultrasonic images}, series = {Proceedings of the 15th International Joint Conference on Computer Vision, Imaging and Computer Graphics Theory and Applications - Volume 5}, booktitle = {Proceedings of the 15th International Joint Conference on Computer Vision, Imaging and Computer Graphics Theory and Applications - Volume 5}, publisher = {SciTePress}, address = {Set{\´u}bal, Portugal}, isbn = {978-989-758-402-2}, doi = {10.5220/0008933900790086}, pages = {79 -- 86}, year = {2020}, abstract = {We compare four different algorithms for automatically estimating the muscle fascicle angle from ultrasonic images: the vesselness filter, the Radon transform, the projection profile method and the gray level cooccurence matrix (GLCM). The algorithm results are compared to ground truth data generated by three different experts on 425 image frames from two videos recorded during different types of motion. The best agreement with the ground truth data was achieved by a combination of pre-processing with a vesselness filter and measuring the angle with the projection profile method. The robustness of the estimation is increased by applying the algorithms to subregions with high gradients and performing a LOESS fit through these estimates.}, language = {en} } @article{RauschHarbrechtKahmannetal.2020, author = {Rausch, Valentin and Harbrecht, Andreas and Kahmann, Stephanie Lucina and Fenten, Thomas and Jovanovic, Nebojsa and Hackl, Michael and M{\"u}ller, Lars P. and Staat, Manfred and Wegmann, Kilian}, title = {Osteosynthesis of Phalangeal Fractures: Biomechanical Comparison of Kirschner Wires, Plates, and Compression Screws}, series = {The Journal of Hand Surgery}, volume = {45}, journal = {The Journal of Hand Surgery}, number = {10}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0363-5023}, doi = {10.1016/j.jhsa.2020.04.010}, pages = {987.e1 -- 987.e8}, year = {2020}, abstract = {Purpose The aim of this study was to compare several osteosynthesis techniques (intramedullary headless compression screws, T-plates, and Kirschner wires) for distal epiphyseal fractures of proximal phalanges in a human cadaveric model. Methods A total of 90 proximal phalanges from 30 specimens (index, ring, and middle fingers) were used for this study. After stripping off all soft tissue, a transverse distal epiphyseal fracture was simulated at the proximal phalanx. The 30 specimens were randomly assigned to 1 fixation technique (30 per technique), either a 3.0-mm intramedullary headless compression screw, locking plate fixation with a 2.0-mm T-plate, or 2 oblique 1.0-mm Kirschner wires. Displacement analysis (bending, distraction, and torsion) was performed using optical tracking of an applied random speckle pattern after osteosynthesis. Biomechanical testing was performed with increasing cyclic loading and with cyclic load to failure using a biaxial torsion-tension testing machine. Results Cannulated intramedullary compression screws showed significantly less displacement at the fracture site in torsional testing. Furthermore, screws were significantly more stable in bending testing. Kirschner wires were significantly less stable than plating or screw fixation in any cyclic load to failure test setup. Conclusions Intramedullary compression screws are a highly stable alternative in the treatment of transverse distal epiphyseal phalangeal fractures. Kirschner wires seem to be inferior regarding displacement properties and primary stability. Clinical relevance Fracture fixation of phalangeal fractures using plate osteosynthesis may have the advantage of a very rigid reduction, but disadvantages such as stiffness owing to the more invasive surgical approach and soft tissue irritation should be taken into account. Headless compression screws represent a minimally invasive choice for fixation with good biomechanical properties.}, language = {en} } @inproceedings{ElgamalHeuermann2020, author = {Elgamal, Abdelrahman and Heuermann, Holger}, title = {Design and Development of a Hot S-Parameter Measurement System for Plasma and Magnetron Applications}, series = {Proceedings of the 2020 German Microwave Conference}, booktitle = {Proceedings of the 2020 German Microwave Conference}, publisher = {IEEE}, address = {New York, NY}, isbn = {978-3-9820397-1-8}, pages = {124 -- 127}, year = {2020}, abstract = {This paper presents the design, development and calibration procedures of a novel hot S-parameter measurement system for plasma and magnetron applications with power level up to 6 kW. Based on a vector network analyzer, a power amplifier and two directional couplers, the input matching hotS 11 and transmission hotS 21 of the device under test are measured at 2.45 GHz center frequency and 300MHz bandwidth, while the device is driven by the magnetron. This measurement system opens a new horizon to develop many new industrial applications such as microwave plasma jets, dryer systems, dryers and so forth. Furthermore, the developing, controlling and monitoring a 2kW 2.45GHz plasma jet and a dryer system using the measurement system are presented and explained.}, language = {en} } @inproceedings{KirschMatareFerreinetal.2020, author = {Kirsch, Maximilian and Matar{\´e}, Victor and Ferrein, Alexander and Schiffer, Stefan}, title = {Integrating golog++ and ROS for Practical and Portable High-level Control}, series = {Proceedings of the 12th International Conference on Agents and Artificial Intelligence - Volume 2}, booktitle = {Proceedings of the 12th International Conference on Agents and Artificial Intelligence - Volume 2}, publisher = {SciTePress}, address = {Set{\´u}bal, Portugal}, doi = {10.5220/0008984406920699}, pages = {692 -- 699}, year = {2020}, abstract = {The field of Cognitive Robotics aims at intelligent decision making of autonomous robots. It has matured over the last 25 or so years quite a bit. That is, a number of high-level control languages and architectures have emerged from the field. One concern in this regard is the action language GOLOG. GOLOG has been used in a rather large number of applications as a high-level control language ranging from intelligent service robots to soccer robots. For the lower level robot software, the Robot Operating System (ROS) has been around for more than a decade now and it has developed into the standard middleware for robot applications. ROS provides a large number of packages for standard tasks in robotics like localisation, navigation, and object recognition. Interestingly enough, only little work within ROS has gone into the high-level control of robots. In this paper, we describe our approach to marry the GOLOG action language with ROS. In particular, we present our architecture on inte grating golog++, which is based on the GOLOG dialect Readylog, with the Robot Operating System. With an example application on the Pepper service robot, we show how primitive actions can be easily mapped to the ROS ActionLib framework and present our control architecture in detail.}, language = {en} } @article{DantismRoehlenDahmenetal.2020, author = {Dantism, Shahriar and R{\"o}hlen, Desiree and Dahmen, Markus and Wagner, Torsten and Wagner, Patrick and Sch{\"o}ning, Michael Josef}, title = {LAPS-based monitoring of metabolic responses of bacterial cultures in a paper fermentation broth}, series = {Sensors and Actuators B: Chemical}, volume = {320}, journal = {Sensors and Actuators B: Chemical}, number = {Art. 128232}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0925-4005}, doi = {10.1016/j.snb.2020.128232}, year = {2020}, abstract = {As an alternative renewable energy source, methane production in biogas plants is gaining more and more attention. Biomass in a bioreactor contains different types of microorganisms, which should be considered in terms of process-stability control. Metabolically inactive microorganisms within the fermentation process can lead to undesirable, time-consuming and cost-intensive interventions. Hence, monitoring of the cellular metabolism of bacterial populations in a fermentation broth is crucial to improve the biogas production, operation efficiency, and sustainability. In this work, the extracellular acidification of bacteria in a paper-fermentation broth is monitored after glucose uptake, utilizing a differential light-addressable potentiometric sensor (LAPS) system. The LAPS system is loaded with three different model microorganisms (Escherichia coli, Corynebacterium glutamicum, and Lactobacillus brevis) and the effect of the fermentation broth at different process stages on the metabolism of these bacteria is studied. In this way, different signal patterns related to the metabolic response of microorganisms can be identified. By means of calibration curves after glucose uptake, the overall extracellular acidification of bacterial populations within the fermentation process can be evaluated.}, language = {en} } @article{BayerTemizArtmannDigeletal.2020, author = {Bayer, Robin and Temiz Artmann, Ayseg{\"u}l and Digel, Ilya and Falkenstein, Julia and Artmann, Gerhard and Creutz, Till and Hescheler, J{\"u}rgen}, title = {Mechano-pharmacological testing of L-Type Ca²⁺ channel modulators via human vascular celldrum model}, series = {Cellular Physiology and Biochemistry}, volume = {54}, journal = {Cellular Physiology and Biochemistry}, publisher = {Cell Physiol Biochem Press}, address = {D{\"u}sseldorf}, issn = {1421-9778}, doi = {10.33594/000000225}, pages = {371 -- 383}, year = {2020}, abstract = {Background/Aims: This study aimed to establish a precise and well-defined working model, assessing pharmaceutical effects on vascular smooth muscle cell monolayer in-vitro. It describes various analysis techniques to determine the most suitable to measure the biomechanical impact of vasoactive agents by using CellDrum technology. Methods: The so-called CellDrum technology was applied to analyse the biomechanical properties of confluent human aorta muscle cells (haSMC) in monolayer. The cell generated tensions deviations in the range of a few N/m² are evaluated by the CellDrum technology. This study focuses on the dilative and contractive effects of L-type Ca²⁺ channel agonists and antagonists, respectively. We analyzed the effects of Bay K8644, nifedipine and verapamil. Three different measurement modes were developed and applied to determine the most appropriate analysis technique for the study purpose. These three operation modes are called, particular time mode" (PTM), "long term mode" (LTM) and "real-time mode" (RTM). Results: It was possible to quantify the biomechanical response of haSMCs to the addition of vasoactive agents using CellDrum technology. Due to the supplementation of 100nM Bay K8644, the tension increased approximately 10.6\% from initial tension maximum, whereas, the treatment with nifedipine and verapamil caused a significant decrease in cellular tension: 10nM nifedipine decreased the biomechanical stress around 6,5\% and 50nM verapamil by 2,8\%, compared to the initial tension maximum. Additionally, all tested measurement modes provide similar results while focusing on different analysis parameters. Conclusion: The CellDrum technology allows highly sensitive biomechanical stress measurements of cultured haSMC monolayers. The mechanical stress responses evoked by the application of vasoactive calcium channel modulators were quantified functionally (N/m²). All tested operation modes resulted in equal findings, whereas each mode features operation-related data analysis.}, language = {en} } @article{FingerGoettenBraunetal.2020, 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 = {CEAS Aeronautical Journal}, volume = {2020}, journal = {CEAS Aeronautical Journal}, number = {11}, publisher = {Springer}, address = {Heidelberg}, issn = {1869-5590}, doi = {10.1007/s13272-020-00449-8}, pages = {713 -- 730}, year = {2020}, abstract = {For short take-off and landing (STOL) aircraft, a parallel hybrid-electric propulsion system potentially offers superior performance compared to a conventional propulsion system, because the short-take-off power requirement is much higher than the cruise power requirement. This power-matching problem can be solved with a balanced hybrid propulsion system. However, there is a trade-off between wing loading, power loading, the level of hybridization, as well as range and take-off distance. An optimization method can vary design variables in such a way that a minimum of a particular objective is attained. In this paper, a comparison between the optimization results for minimum mass, minimum consumed primary energy, and minimum cost is conducted. A new initial sizing algorithm for general aviation aircraft with hybrid-electric propulsion systems is applied. This initial sizing methodology covers point performance, mission performance analysis, the weight estimation process, and cost estimation. The methodology is applied to the design of a STOL general aviation aircraft, intended for on-demand air mobility operations. The aircraft is sized to carry eight passengers over a distance of 500 km, while able to take off and land from short airstrips. Results indicate that parallel hybrid-electric propulsion systems must be considered for future STOL aircraft.}, language = {en} } @article{EggertAlberts2020, author = {Eggert, Mathias and Alberts, Jens}, title = {Frontiers of business intelligence and analytics 3.0: a taxonomy-based literature review and research agenda}, series = {Business Research}, volume = {2020}, journal = {Business Research}, number = {13}, publisher = {Springer}, address = {Heidelberg}, issn = {2198-2627}, doi = {10.1007/s40685-020-00108-y}, pages = {685 -- 739}, year = {2020}, abstract = {Researching the field of business intelligence and analytics (BI \& A) has a long tradition within information systems research. Thereby, in each decade the rapid development of technologies opened new room for investigation. Since the early 1950s, the collection and analysis of structured data were the focus of interest, followed by unstructured data since the early 1990s. The third wave of BI \& A comprises unstructured and sensor data of mobile devices. The article at hand aims at drawing a comprehensive overview of the status quo in relevant BI \& A research of the current decade, focusing on the third wave of BI \& A. By this means, the paper's contribution is fourfold. First, a systematically developed taxonomy for BI \& A 3.0 research, containing seven dimensions and 40 characteristics, is presented. Second, the results of a structured literature review containing 75 full research papers are analyzed by applying the developed taxonomy. The analysis provides an overview on the status quo of BI \& A 3.0. Third, the results foster discussions on the predicted and observed developments in BI \& A research of the past decade. Fourth, research gaps of the third wave of BI \& A research are disclosed and concluded in a research agenda.}, language = {en} } @article{SmithKotliarLammertynetal.2020, author = {Smith, Wayne and Kotliar, Konstantin and Lammertyn, Leandi and Ramoshaba, Nthai E. and Vilser, Walthard and Huisman, Hugo W. and Schutte, Aletta E.}, title = {Retinal vessel caliber and caliber responses in true normotensive black and white adults: The African-PREDICT study}, series = {Microvascular Research}, volume = {128}, journal = {Microvascular Research}, number = {Article 103937}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0026-2862}, doi = {10.1016/j.mvr.2019.103937}, year = {2020}, abstract = {Purpose Globally, a detrimental shift in cardiovascular disease risk factors and a higher mortality level are reported in some black populations. The retinal microvasculature provides early insight into the pathogenesis of systemic vascular diseases, but it is unclear whether retinal vessel calibers and acute retinal vessel functional responses differ between young healthy black and white adults. Methods We included 112 black and 143 white healthy normotensive adults (20-30 years). Retinal vessel calibers (central retinal artery and vein equivalent (CRAE and CRVE)) were calculated from retinal images and vessel caliber responses to flicker light induced provocation (FLIP) were determined. Additionally, ambulatory blood pressure (BP), anthropometry and blood samples were collected. Results The groups displayed similar 24 h BP profiles and anthropometry (all p > .24). Black participants demonstrated a smaller CRAE (158 ± 11 vs. 164 ± 11 MU, p < .001) compared to the white group, whereas CRVE was similar (p = .57). In response to FLIP, artery maximal dilation was greater in the black vs. white group (5.6 ± 2.1 vs. 3.3 ± 1.8\%; p < .001). Conclusions Already at a young age, healthy black adults showed narrower retinal arteries relative to the white population. Follow-up studies are underway to show if this will be related to increased risk for hypertension development. The reason for the larger vessel dilation responses to FLIP in the black population is unclear and warrants further investigation.}, language = {en} } @article{StreeseKotliarDeiserothetal.2020, author = {Streese, Lukas and Kotliar, Konstantin and Deiseroth, Arne and Infanger, Denis and Gugleta, Konstantin and Schmaderer, Christoph and Hanssen, Henner}, title = {Retinal endothelial function in cardiovascular risk patients: A randomized controlled exercise trial}, series = {Scandinavian Journal of Medicine and Science in Sports}, volume = {30}, journal = {Scandinavian Journal of Medicine and Science in Sports}, number = {2}, publisher = {Wiley}, address = {Oxford}, issn = {1600-0838}, doi = {10.1111/sms.13560}, pages = {272 -- 280}, year = {2020}, abstract = {The aim of this study was to investigate, for the first time, the effects of high-intensity interval training (HIIT) on retinal microvascular endothelial function in cardiovascular (CV) risk patients. In the randomized controlled trial, middle-aged and previously sedentary patients with increased CV risk (aged 58 ± 6 years) with ≥ two CV risk factors were randomized into a 12-week HIIT (n = 33) or control group (CG, n = 36) with standard physical activity recommendations. A blinded examiner measured retinal endothelial function by flicker light-induced maximal arteriolar (ADmax) and venular (VDmax) dilatation as well as the area under the arteriolar (AFarea) and venular (VFarea) flicker curve using a retinal vessel analyzer. Standardized assessments of CV risk factors, cardiorespiratory fitness, and retinal endothelial function were performed before and after HIIT. HIIT reduced body mass index, fat mass, and low-density lipoprotein and increased muscle mass and peak oxygen uptake (VO2peak). Both ADmax (pre: 2.7 ± 2.1\%, post: 3.0 ± 2.2\%, P = .018) and AFarea (pre: 32.6 ± 28.4\%*s, post: 37.7 ± 30.6\%*s, P = .016) increased after HIIT compared with CG (ADmax, pre: 3.2 ± 1.8\%, post: 2.9 ± 1.8\%, P = .254; AFarea, pre: 41.6 ± 28.5\%*s, post: 37.8 ± 27.0\%*s, P = .186). Venular function remained unchanged after HIIT. There was a significant association between ∆-change VO2peak and ∆-changes ADmax and AFarea (P = .026, R² = 0.073; P = .019, R² = 0.081, respectively). 12-weeks of HIIT improved retinal endothelial function in middle-aged patients with increased CV risk independent of the reduction in classical CV risk factors. Exercise has the potential to reverse or at least postpone progression of small vessel disease in older adults with increased CV risk under standard medication. Dynamic retinal vessel analysis seems to be a sensitive tool to detect treatment effects of exercise interventions on retinal microvascular endothelial function in middle-aged individuals with increased CV risk.}, language = {en} } @article{SchmidtTurgutLeetal.2020, author = {Schmidt, Aaron C. and Turgut, Hatice and Le, Dao and Beloqui, Ana and Delaittre, Guillaume}, title = {Making the best of it: nitroxide-mediated polymerization of methacrylates via the copolymerization approach with functional styrenics}, series = {Polymer Chemistry}, volume = {11}, journal = {Polymer Chemistry}, number = {2}, publisher = {Royal Society of Chemistry (RSC)}, address = {Cambridge}, doi = {10.1039/C9PY01458F}, pages = {593 -- 604}, year = {2020}, abstract = {The SG1-mediated solution polymerization of methyl methacrylate (MMA) and oligo(ethylene glycol) methacrylate (OEGMA, Mₙ = 300 g mol⁻¹) in the presence of a small amount of functional/reactive styrenic comonomer is investigated. Moieties such as pentafluorophenyl ester, triphenylphosphine, azide, pentafluorophenyl, halide, and pyridine are considered. A comonomer fraction as low as 5 mol\% typically results in a controlled/living behavior, at least up to 50\% conversion. Chain extensions with styrene for both systems were successfully performed. Variation of physical properties such as refractive index (for MMA) and phase transition temperature (for OEGMA) were evaluated by comparing to 100\% pure homopolymers. The introduction of an activated ester styrene derivative in the polymerization of OEGMA allows for the synthesis of reactive and hydrophilic polymer brushes with defined thickness. Finally, using the example of pentafluorostyrene as controlling comonomer, it is demonstrated that functional PMMA-b-PS are able to maintain a phase separation ability, as evidenced by the formation of nanostructured thin films.}, language = {en} } @article{HamouKotliarTanetal.2020, author = {Hamou, Hussam Aldin and Kotliar, Konstantin and Tan, Sonny Kian and Weiß, Christel and Blume, Christian and Clusmann, Hans and Schubert, Gerrit Alexander and Albanna, Walid}, title = {Surgical nuances and placement of subgaleal drains for supratentorial procedures—a prospective analysis of efficacy and outcome in 150 craniotomies}, series = {Acta Neurochirurgica}, volume = {2020}, journal = {Acta Neurochirurgica}, number = {162}, publisher = {Springer Nature}, address = {Cham}, issn = {0942-0940}, doi = {10.1007/s00701-019-04196-6}, pages = {729 -- 736}, year = {2020}, abstract = {Background For supratentorial craniotomy, surgical access, and closure technique, including placement of subgaleal drains, may vary considerably. The influence of surgical nuances on postoperative complications such as cerebrospinal fluid leakage or impaired wound healing overall remains largely unclear. With this study, we are reporting our experiences and the impact of our clinical routines on outcome in a prospectively collected data set. Method We prospectively observed 150 consecutive patients undergoing supratentorial craniotomy and recorded technical variables (type/length of incision, size of craniotomy, technique of dural and skin closure, type of dressing, and placement of subgaleal drains). Outcome variables (subgaleal hematoma/CSF collection, periorbital edema, impairment of wound healing, infection, and need for operative revision) were recorded at time of discharge and at late follow-up. Results Early subgaleal fluid collection was observed in 36.7\% (2.8\% at the late follow-up), and impaired wound healing was recorded in 3.3\% of all cases, with an overall need for operative revision of 6.7\%. Neither usage of dural sealants, lack of watertight dural closure, and presence of subgaleal drains, nor type of skin closure or dressing influenced outcome. Curved incisions, larger craniotomy, and tumor size, however, were associated with an increase in early CSF or hematoma collection (p < 0.0001, p = 0.001, p < 0.01 resp.), and larger craniotomy size was associated with longer persistence of subgaleal fluid collections (p < 0.05). Conclusions Based on our setting, individual surgical nuances such as the type of dural closure and the use of subgaleal drains resulted in a comparable complication rate and outcome. Subgaleal fluid collections were frequently observed after supratentorial procedures, irrespective of the closing technique employed, and resolve spontaneously in the majority of cases without significant sequelae. Our results are limited due to the observational nature in our single-center study and need to be validated by supportive prospective randomized design.}, language = {en} } @article{DigelKernGeenenetal.2020, author = {Digel, Ilya and Kern, Inna and Geenen, Eva-Maria and Akimbekov, Nuraly S.}, title = {Dental plaque removal by ultrasonic toothbrushes}, series = {dentistry journal}, volume = {8}, journal = {dentistry journal}, number = {28}, publisher = {MDPI}, address = {Basel}, issn = {2304-6767}, doi = {10.3390/dj8010028}, pages = {1 -- 13}, year = {2020}, abstract = {With the variety of toothbrushes on the market, the question arises, which toothbrush is best suited to maintain oral health? This thematic review focuses first on plaque formation mechanisms and then on the plaque removal effectiveness of ultrasonic toothbrushes and their potential in preventing oral diseases like periodontitis, gingivitis, and caries. We overviewed the physical effects that occurred during brushing and tried to address the question of whether ultrasonic toothbrushes effectively reduced the microbial burden by increasing the hydrodynamic forces. The results of published studies show that electric toothbrushes, which combine ultrasonic and sonic (or acoustic and mechanic) actions, may have the most promising effect on good oral health. Existing ultrasonic/sonic toothbrush models do not significantly differ regarding the removal of dental biofilm and the reduction of gingival inflammation compared with other electrically powered toothbrushes, whereas the manual toothbrushes show a lower effectiveness.}, language = {en} } @inproceedings{DinghoferHartung2020, author = {Dinghofer, Kai and Hartung, Frank}, title = {Analysis of Criteria for the Selection of Machine Learning Frameworks}, series = {2020 International Conference on Computing, Networking and Communications (ICNC)}, booktitle = {2020 International Conference on Computing, Networking and Communications (ICNC)}, publisher = {IEEE}, address = {New York, NY}, doi = {10.1109/ICNC47757.2020.9049650}, pages = {373 -- 377}, year = {2020}, abstract = {With the many achievements of Machine Learning in the past years, it is likely that the sub-area of Deep Learning will continue to deliver major technological breakthroughs [1]. In order to achieve best results, it is important to know the various different Deep Learning frameworks and their respective properties. This paper provides a comparative overview of some of the most popular frameworks. First, the comparison methods and criteria are introduced and described with a focus on computer vision applications: Features and Uses are examined by evaluating papers and articles, Adoption and Popularity is determined by analyzing a data science study. Then, the frameworks TensorFlow, Keras, PyTorch and Caffe are compared based on the previously described criteria to highlight properties and differences. Advantages and disadvantages are compared, enabling researchers and developers to choose a framework according to their specific needs.}, language = {en} } @article{MuschallikMolinnusJablonskietal.2020, author = {Muschallik, Lukas and Molinnus, Denise and Jablonski, Melanie and Kipp, Carina Ronja and Bongaerts, Johannes and Pohl, Martina and Wagner, Torsten and Sch{\"o}ning, Michael Josef and Selmer, Thorsten and Siegert, Petra}, title = {Synthesis of α-hydroxy ketones and vicinal (R, R)-diols by Bacillus clausii DSM 8716ᵀ butanediol dehydrogenase}, series = {RSC Advances}, volume = {10}, journal = {RSC Advances}, publisher = {Royal Society of Chemistry (RSC)}, address = {Cambridge}, issn = {2046-2069}, doi = {10.1039/D0RA02066D}, pages = {12206 -- 12216}, year = {2020}, abstract = {α-hydroxy ketones (HK) and 1,2-diols are important building blocks for fine chemical synthesis. Here, we describe the R-selective 2,3-butanediol dehydrogenase from B. clausii DSM 8716ᵀ (BcBDH) that belongs to the metal-dependent medium chain dehydrogenases/reductases family (MDR) and catalyzes the selective asymmetric reduction of prochiral 1,2-diketones to the corresponding HK and, in some cases, the reduction of the same to the corresponding 1,2-diols. Aliphatic diketones, like 2,3-pentanedione, 2,3-hexanedione, 5-methyl-2,3-hexanedione, 3,4-hexanedione and 2,3-heptanedione are well transformed. In addition, surprisingly alkyl phenyl dicarbonyls, like 2-hydroxy-1-phenylpropan-1-one and phenylglyoxal are accepted, whereas their derivatives with two phenyl groups are not substrates. Supplementation of Mn²⁺ (1 mM) increases BcBDH's activity in biotransformations. Furthermore, the biocatalytic reduction of 5-methyl-2,3-hexanedione to mainly 5-methyl-3-hydroxy-2-hexanone with only small amounts of 5-methyl-2-hydroxy-3-hexanone within an enzyme membrane reactor is demonstrated.}, language = {en} } @inproceedings{RekePeterSchulteTiggesetal.2020, author = {Reke, Michael and Peter, Daniel and Schulte-Tigges, Joschua and Schiffer, Stefan and Ferrein, Alexander and Walter, Thomas and Matheis, Dominik}, title = {A Self-Driving Car Architecture in ROS2}, series = {2020 International SAUPEC/RobMech/PRASA Conference, Cape Town, South Africa}, booktitle = {2020 International SAUPEC/RobMech/PRASA Conference, Cape Town, South Africa}, publisher = {IEEE}, address = {New York, NY}, isbn = {978-1-7281-4162-6}, doi = {10.1109/SAUPEC/RobMech/PRASA48453.2020.9041020}, pages = {1 -- 6}, year = {2020}, abstract = {In this paper we report on an architecture for a self-driving car that is based on ROS2. Self-driving cars have to take decisions based on their sensory input in real-time, providing high reliability with a strong demand in functional safety. In principle, self-driving cars are robots. However, typical robot software, in general, and the previous version of the Robot Operating System (ROS), in particular, does not always meet these requirements. With the successor ROS2 the situation has changed and it might be considered as a solution for automated and autonomous driving. Existing robotic software based on ROS was not ready for safety critical applications like self-driving cars. We propose an architecture for using ROS2 for a self-driving car that enables safe and reliable real-time behaviour, but keeping the advantages of ROS such as a distributed architecture and standardised message types. First experiments with an automated real passenger car at lower and higher speed-levels show that our approach seems feasible for autonomous driving under the necessary real-time conditions.}, language = {en} } @article{WeldenSchoeningWagneretal.2020, author = {Welden, Rene and Sch{\"o}ning, Michael Josef and Wagner, Patrick H. and Wagner, Torsten}, title = {Light-Addressable Electrodes for Dynamic and Flexible Addressing of Biological Systems and Electrochemical Reactions}, series = {Sensors}, volume = {20}, journal = {Sensors}, number = {6}, publisher = {MDPI}, address = {Basel}, issn = {1424-8220}, doi = {10.3390/s20061680}, pages = {Artikel 1680}, year = {2020}, abstract = {In this review article, we are going to present an overview on possible applications of light-addressable electrodes (LAE) as actuator/manipulation devices besides classical electrode structures. For LAEs, the electrode material consists of a semiconductor. Illumination with a light source with the appropiate wavelength leads to the generation of electron-hole pairs which can be utilized for further photoelectrochemical reaction. Due to recent progress in light-projection technologies, highly dynamic and flexible illumination patterns can be generated, opening new possibilities for light-addressable electrodes. A short introduction on semiconductor-electrolyte interfaces with light stimulation is given together with electrode-design approaches. Towards applications, the stimulation of cells with different electrode materials and fabrication designs is explained, followed by analyte-manipulation strategies and spatially resolved photoelectrochemical deposition of different material types.}, language = {en} } @article{KerresGredigkHoffmannJatheetal.2020, author = {Kerres, Karsten and Gredigk-Hoffmann, Sylvia and Jathe, R{\"u}diger and Orlik, Stefan and Sariyildiz, Mustafa and Schmidt, Torsten and Sympher, Klaus-Jochen and Uhlenbroch, Adrian}, title = {Future approaches for sewer system condition assessment}, series = {Water Practice \& Technology}, journal = {Water Practice \& Technology}, number = {15 (2)}, publisher = {IWA Publishing}, address = {London}, issn = {1751-231X}, doi = {10.2166/wpt.2020.027}, pages = {386 -- 393}, year = {2020}, abstract = {Different analytical approaches exist to describe the structural substance or wear reserve of sewer systems. The aim is to convert engineering assessments of often complex defect patterns into computational algorithms and determine a substance class for a sewer section or manhole. This analytically determined information is essential for strategic rehabilitation planning processes up to network level, as it corresponds to the most appropriate rehabilitation type and can thus provide decision-making support. Current calculation methods differ clearly from each other in parts, so that substance classes determined by the different approaches are only partially comparable with each other. The objective of the German R\&D cooperation project 'SubKanS' is to develop a methodology for classifying the specific defect patterns resulting from the interaction of all the individual defects, and their severities and locations. The methodology takes into account the structural substance of sewer sections and manholes, based on real data and theoretical considerations analogous to the condition classification of individual defects. The result is a catalogue of defect patterns and characteristics, as well as associated structural substance classifications of sewer systems (substance classes). The methodology for sewer system substance classification is developed so that the classification of individual defects can be transferred into a substance class of the sewer section or manhole, eventually taking into account further information (e.g. pipe material, nominal diameter, etc.). The result is a validated methodology for automated sewer system substance classification.}, language = {en} } @article{Koehler2020, author = {K{\"o}hler, Klemens}, title = {A conflict theory perspective of IT attacks - consequences for IT security education}, number = {Preprint}, year = {2020}, abstract = {Cyberspace is "the environment formed by physical and non-physical components to store, modify, and exchange data using computer networks" (NATO CCDCOE). Beyond that, it is an environment where people interact. IT attacks are hostile, non-cooperative interactions that can be described with conflict theory. Applying conflict theory to IT security leads to different objectives for end-user education, requiring different formats like agency-based competence developing games.}, language = {en} } @article{FingerBraunBil2020, author = {Finger, Felix and Braun, Carsten and Bil, Cees}, title = {Impact of Battery Performance on the Initial Sizing of Hybrid-Electric General Aviation Aircraft}, series = {Journal of Aerospace Engineering}, volume = {33}, journal = {Journal of Aerospace Engineering}, number = {3}, publisher = {ASCE}, address = {Reston, Va.}, issn = {1943-5525}, doi = {10.1061/(ASCE)AS.1943-5525.0001113}, year = {2020}, abstract = {Studies suggest that hybrid-electric aircraft have the potential to generate fewer emissions and be inherently quieter when compared to conventional aircraft. By operating combustion engines together with an electric propulsion system, synergistic benefits can be obtained. However, the performance of hybrid-electric aircraft is still constrained by a battery's energy density and discharge rate. In this paper, the influence of battery performance on the gross mass for a four-seat general aviation aircraft with a hybrid-electric propulsion system is analyzed. For this design study, a high-level approach is chosen, using an innovative initial sizing methodology to determine the minimum required aircraft mass for a specific set of requirements and constraints. Only the peak-load shaving operational strategy is analyzed. Both parallel- and serial-hybrid propulsion configurations are considered for two different missions. The specific energy of the battery pack is varied from 200 to 1,000 W⋅h/kg, while the discharge time, and thus the normalized discharge rating (C-rating), is varied between 30 min (2C discharge rate) and 2 min (30C discharge rate). With the peak-load shaving operating strategy, it is desirable for hybrid-electric aircraft to use a light, low capacity battery system to boost performance. For this case, the battery's specific power rating proved to be of much higher importance than for full electric designs, which have high capacity batteries. Discharge ratings of 20C allow a significant take-off mass reduction aircraft. The design point moves to higher wing loadings and higher levels of hybridization if batteries with advanced technology are used.}, language = {en} } @article{JildehKirchnerOberlaenderetal.2020, author = {Jildeh, Zaid B. and Kirchner, Patrick and Oberl{\"a}nder, Jan and Vahidpour, Farnoosh and Wagner, Patrick H. and Sch{\"o}ning, Michael Josef}, title = {Development of a package-sterilization process for aseptic filling machines: A numerical approach and validation for surface treatment with hydrogen peroxide}, series = {Sensor and Actuators A: Physical}, volume = {303}, journal = {Sensor and Actuators A: Physical}, number = {111691}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0924-4247}, doi = {10.1016/j.sna.2019.111691}, year = {2020}, abstract = {Within the present work a sterilization process by a heated gas mixture that contains hydrogen peroxide (H₂O₂) is validated by experiments and numerical modeling techniques. The operational parameters that affect the sterilization efficacy are described alongside the two modes of sterilization: gaseous and condensed H₂O₂. Measurements with a previously developed H₂O₂ gas sensor are carried out to validate the applied H₂O₂ gas concentration during sterilization. We performed microbiological tests at different H₂O₂ gas concentrations by applying an end-point method to carrier strips, which contain different inoculation loads of Geobacillus stearothermophilus spores. The analysis of the sterilization process of a pharmaceutical glass vial is performed by numerical modeling. The numerical model combines heat- and advection-diffusion mass transfer with vapor-pressure equations to predict the location of condensate formation and the concentration of H₂O₂ at the packaging surfaces by changing the gas temperature. For a sterilization process of 0.7 s, a H₂O₂ gas concentration above 4\% v/v is required to reach a log-count reduction above six. The numerical results showed the location of H₂O₂ condensate formation, which decreases with increasing sterilant-gas temperature. The model can be transferred to different gas nozzle- and packaging geometries to assure the absence of H₂O₂ residues.}, language = {en} } @inproceedings{KreyerMuellerEsch2020, author = {Kreyer, J{\"o}rg and M{\"u}ller, Marvin and Esch, Thomas}, title = {A Map-Based Model for the Determination of Fuel Consumption for Internal Combustion Engines as a Function of Flight Altitude}, publisher = {DGLR}, address = {Bonn}, doi = {10.25967/490162}, pages = {13 Seiten}, year = {2020}, abstract = {In addition to very high safety and reliability requirements, the design of internal combustion engines (ICE) in aviation focuses on economic efficiency. The objective must be to design the aircraft powertrain optimized for a specific flight mission with respect to fuel consumption and specific engine power. Against this background, expert tools provide valuable decision-making assistance for the customer. In this paper, a mathematical calculation model for the fuel consumption of aircraft ICE is presented. This model enables the derivation of fuel consumption maps for different engine configurations. Depending on the flight conditions and based on these maps, the current and the integrated fuel consumption for freely definable flight emissions is calculated. For that purpose, an interpolation method is used, that has been optimized for accuracy and calculation time. The mission boundary conditions flight altitude and power requirement of the ICE form the basis for this calculation. The mathematical fuel consumption model is embedded in a parent program. This parent program presents the simulated fuel consumption by means of an example flight mission for a representative airplane. The focus of the work is therefore on reproducing exact consumption data for flight operations. By use of the empirical approaches according to Gagg-Farrar [1] the power and fuel consumption as a function of the flight altitude are determined. To substantiate this approaches, a 1-D ICE model based on the multi-physical simulation tool GT-Suite® has been created. This 1-D engine model offers the possibility to analyze the filling and gas change processes, the internal combustion as well as heat and friction losses for an ICE under altitude environmental conditions. Performance measurements on a dynamometer at sea level for a naturally aspirated ICE with a displacement of 1211 ccm used in an aviation aircraft has been done to validate the 1-D ICE model. To check the plausibility of the empirical approaches with respect to the fuel consumption and performance adjustment for the flight altitude an analysis of the ICE efficiency chain of the 1-D engine model is done. In addition, a comparison of literature and manufacturer data with the simulation results is presented.}, language = {en} } @inproceedings{FingerBraunBil2020, author = {Finger, Felix and Braun, Carsten and Bil, Cees}, title = {Comparative assessment of parallel-hybrid-electric propulsion systems for four different aircraft}, series = {AIAA Scitech 2020 Forum}, booktitle = {AIAA Scitech 2020 Forum}, doi = {10.2514/6.2020-1502}, pages = {15 Seiten}, year = {2020}, abstract = {As battery technologies advance, electric propulsion concepts are on the edge of disrupting aviation markets. However, until electric energy storage systems are ready to allow fully electric aircraft, the combination of combustion engine and electric motor as a hybrid-electric propulsion system seems to be a promising intermediate solution. Consequently, the design space for future aircraft is expanded considerably, as serial-hybrid-, parallel-hybrid-, fully-electric, and conventional propulsion systems must all be considered. While the best propulsion system depends on a multitude of requirements and considerations, trends can be observed for certain types of aircraft and certain types of missions. This paper provides insight into some factors that drive a new design towards either conventional or hybrid propulsion systems. General aviation aircraft, VTOL air taxis, transport aircraft, and UAVs are chosen as case studies. Typical missions for each class are considered, and the aircraft are analyzed regarding their take-off mass and primary energy consumption. For these case studies, a high-level approach is chosen, using an initial sizing methodology. Results indicate that hybrid-electric propulsion systems should be considered if the propulsion system is sized by short-duration power constraints (e.g. take-off, climb). However, if the propulsion system is sized by a continuous power requirement (e.g. cruise), hybrid-electric systems offer hardly any benefit.}, language = {en} } @article{RauschKahmannBaltschunetal.2020, author = {Rausch, Valentin and Kahmann, Stephanie Lucina and Baltschun, Christoph and Staat, Manfred and M{\"u}ller, Lars P. and Wegmann, Kilian}, title = {Pressure distribution to the distal biceps tendon at the radial tuberosity: a biomechanical study}, series = {The Journal of Hand Surgery}, volume = {45}, journal = {The Journal of Hand Surgery}, number = {8}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0363-5023}, doi = {10.1016/j.jhsa.2020.01.006}, pages = {776.e1 -- 776.e9}, year = {2020}, abstract = {Purpose Mechanical impingement at the narrow radioulnar space of the tuberosity is believed to be an etiological factor in the injury of the distal biceps tendon. The aim of the study was to compare the pressure distribution at the proximal radioulnar space between 2 fixation techniques and the intact state. Methods Six right arms and 6 left arms from 5 female and 6 male frozen specimens were used for this study. A pressure transducer was introduced at the height of the radial tuberosity with the intact distal biceps tendon and after 2 fixation methods: the suture-anchor and the cortical button technique. The force (N), maximum pressure (kPa) applied to the radial tuberosity, and the contact area (mm²) of the radial tuberosity with the ulna were measured and differences from the intact tendon were detected from 60° supination to 60° pronation in 15° increments with the elbow in full extension and in 45° and 90° flexion of the elbow. Results With the distal biceps tendon intact, the pressures during pronation were similar regardless of extension and flexion and were the highest at 60° pronation with 90° elbow flexion (23.3 ± 53.5 kPa). After repair of the tendon, the mean peak pressure, contact area, and total force showed an increase regardless of the fixation technique. Highest peak pressures were found using the cortical button technique at 45° flexion of the elbow and 60° pronation. These differences were significantly different from the intact tendon. The contact area was significantly larger in full extension and 15°, 30°, and 60° pronation using the cortical button technique. Conclusions Pressures on the distal biceps tendon at the radial tuberosity increase during pronation, especially after repair of the tendon. Clinical relevance Mechanical impingement could play a role in both the etiology of primary distal biceps tendon ruptures and the complications occurring after fixation of the tendon using certain techniques.}, language = {en} } @inproceedings{FingerdeVriesVosetal.2020, author = {Finger, Felix and de Vries, Reynard and Vos, Roelof and Braun, Carsten and Bil, Cees}, title = {A comparison of hybrid-electric aircraft sizing methods}, series = {AIAA Scitech 2020 Forum}, booktitle = {AIAA Scitech 2020 Forum}, doi = {10.2514/6.2020-1006}, pages = {31 Seiten}, year = {2020}, abstract = {The number of case studies focusing on hybrid-electric aircraft is steadily increasing, since these configurations are thought to lead to lower operating costs and environmental impact than traditional aircraft. However, due to the lack of reference data of actual hybrid-electric aircraft, in most cases, the design tools and results are difficult to validate. In this paper, two independently developed approaches for hybrid-electric conceptual aircraft design are compared. An existing 19-seat commuter aircraft is selected as the conventional baseline, and both design tools are used to size that aircraft. The aircraft is then re-sized under consideration of hybrid-electric propulsion technology. This is performed for parallel, serial, and fully-electric powertrain architectures. Finally, sensitivity studies are conducted to assess the validity of the basic assumptions and approaches regarding the design of hybrid-electric aircraft. Both methods are found to predict the maximum take-off mass (MTOM) of the reference aircraft with less than 4\% error. The MTOM and payload-range energy efficiency of various (hybrid-) electric configurations are predicted with a maximum difference of approximately 2\% and 5\%, respectively. The results of this study confirm a correct formulation and implementation of the two design methods, and the data obtained can be used by researchers to benchmark and validate their design tools.}, language = {en} } @incollection{AzatKerimkulovaMansurovetal.2020, author = {Azat, Seitkhan and Kerimkulova, Almagul R. and Mansurov, Zulkhair A. and Adekenov, Sergazy and Artmann, Gerhard}, title = {The Use of Fusicoccin as Anticancer Compound}, series = {Carbon Nanomaterials in Biomedicine and the Environment}, booktitle = {Carbon Nanomaterials in Biomedicine and the Environment}, publisher = {Jenny Stanford Publishing}, address = {New York}, isbn = {978-0-429-42864-7}, doi = {10.1201/9780429428647-8}, pages = {149 -- 172}, year = {2020}, abstract = {The problem of creation and use of sorption materials is of current interest for the practice of the modern medicine and agriculture. Practical importance is production of a biostimulant using a carbon sorbent for a significant increase in productivity, which is very relevant for the regions of Kazakhstan. It is known that a plant phytohormone—fusicoccin—in nanogram concentrations transforms cancer cells to the state of apoptosis. In this regard, there is a scientific practical interest in the development of a highly efficient method for producing fusicoccin from extract of germinated wheat seeds. According to the results of computer modeling, cleaning composite components of fusicoccin using microporous carbon adsorbents not suitable as the size of the molecule of fusicoccin more than micropores and the optimum pore size for purification of constituents of fusicoccin was determined by computer simulation.}, language = {en} } @article{CosmaKesslerGebhardtetal.2020, author = {Cosma, Cosmin and Kessler, Julia and Gebhardt, Andreas and Campbell, Ian and Balc, Nicolae}, title = {Improving the Mechanical Strength of Dental Applications and Lattice Structures SLM Processed}, series = {Materials}, volume = {13}, journal = {Materials}, number = {4}, publisher = {MDPI}, address = {Basel}, issn = {1996-1944}, doi = {10.3390/ma13040905}, pages = {1 -- 18}, year = {2020}, abstract = {To manufacture custom medical parts or scaffolds with reduced defects and high mechanical characteristics, new research on optimizing the selective laser melting (SLM) parameters are needed. In this work, a biocompatible powder, 316L stainless steel, is characterized to understand the particle size, distribution, shape and flowability. Examination revealed that the 316L particles are smooth, nearly spherical, their mean diameter is 39.09 μm and just 10\% of them hold a diameter less than 21.18 μm. SLM parameters under consideration include laser power up to 200 W, 250-1500 mm/s scanning speed, 80 μm hatch spacing, 35 μm layer thickness and a preheated platform. The effect of these on processability is evaluated. More than 100 samples are SLM-manufactured with different process parameters. The tensile results show that is possible to raise the ultimate tensile strength up to 840 MPa, adapting the SLM parameters for a stable processability, avoiding the technological defects caused by residual stress. Correlating with other recent studies on SLM technology, the tensile strength is 20\% improved. To validate the SLM parameters and conditions established, complex bioengineering applications such as dental bridges and macro-porous grafts are SLM-processed, demonstrating the potential to manufacture medical products with increased mechanical resistance made of 316L.}, language = {en} } @article{RuppRiekeHandschuhetal.2020, author = {Rupp, Matthias and Rieke, Christian and Handschuh, Nils and Kuperjans, Isabel}, title = {Economic and ecological optimization of electric bus charging considering variable electricity prices and CO₂eq intensities}, series = {Transportation Research Part D: Transport and Environment}, volume = {81}, journal = {Transportation Research Part D: Transport and Environment}, number = {Article 102293}, publisher = {Elsevier}, address = {Amsterdam}, issn = {1361-9209}, doi = {10.1016/j.trd.2020.102293}, year = {2020}, abstract = {In many cities, diesel buses are being replaced by electric buses with the aim of reducing local emissions and thus improving air quality. The protection of the environment and the health of the population is the highest priority of our society. For the transport companies that operate these buses, not only ecological issues but also economic issues are of great importance. Due to the high purchase costs of electric buses compared to conventional buses, operators are forced to use electric vehicles in a targeted manner in order to ensure amortization over the service life of the vehicles. A compromise between ecology and economy must be found in order to both protect the environment and ensure economical operation of the buses. In this study, we present a new methodology for optimizing the vehicles' charging time as a function of the parameters CO₂eq emissions and electricity costs. Based on recorded driving profiles in daily bus operation, the energy demands of conventional and electric buses are calculated for the passenger transportation in the city of Aachen in 2017. Different charging scenarios are defined to analyze the influence of the temporal variability of CO₂eq intensity and electricity price on the environmental impact and economy of the bus. For every individual day of a year, charging periods with the lowest and highest costs and emissions are identified and recommendations for daily bus operation are made. To enable both the ecological and economical operation of the bus, the parameters of electricity price and CO₂ are weighted differently, and several charging periods are proposed, taking into account the priorities previously set. A sensitivity analysis is carried out to evaluate the influence of selected parameters and to derive recommendations for improving the ecological and economic balance of the battery-powered electric vehicle. In all scenarios, the optimization of the charging period results in energy cost savings of a maximum of 13.6\% compared to charging at a fixed electricity price. The savings potential of CO₂eq emissions is similar, at 14.9\%. From an economic point of view, charging between 2 a.m. and 4 a.m. results in the lowest energy costs on average. The CO₂eq intensity is also low in this period, but midday charging leads to the largest savings in CO₂eq emissions. From a life cycle perspective, the electric bus is not economically competitive with the conventional bus. However, from an ecological point of view, the electric bus saves on average 37.5\% CO₂eq emissions over its service life compared to the diesel bus. The reduction potential is maximized if the electric vehicle exclusively consumes electricity from solar and wind power.}, language = {en} } @article{MennickenPeterKaulenetal.2020, author = {Mennicken, Max and Peter, Sophia K. and Kaulen, Corinna and Simon, Ulrich and Karth{\"a}user, Silvia}, title = {Transport through Redox-Active Ru-Terpyridine Complexes Integrated in Single Nanoparticle Devices}, series = {The Journal of Physical Chemistry C}, volume = {124}, journal = {The Journal of Physical Chemistry C}, number = {8}, publisher = {ACS Publications}, address = {Washington, DC}, issn = {1932-7455}, doi = {10.1021/acs.jpcc.9b11716}, pages = {4881 -- 4889}, year = {2020}, abstract = {Transition metal complexes are electrofunctional molecules due to their high conductivity and their intrinsic switching ability involving a metal-to-ligand charge transfer. Here, a method is presented to contact reliably a few to single redox-active Ru-terpyridine complexes in a CMOS compatible nanodevice and preserve their electrical functionality. Using hybrid materials from 14 nm gold nanoparticles (AuNP) and bis-{4′-[4-(mercaptophenyl)-2,2′:6′,2″-terpyridine]}-ruthenium(II) complexes a device size of 30² nm² inclusive nanoelectrodes is achieved. Moreover, this method bears the opportunity for further downscaling. The Ru-complex AuNP devices show symmetric and asymmetric current versus voltage curves with a hysteretic characteristic in two well separated conductance ranges. By theoretical approximations based on the single-channel Landauer model, the charge transport through the formed double-barrier tunnel junction is thoroughly analyzed and its sensibility to the molecule/metal contact is revealed. It can be verified that tunneling transport through the HOMO is the main transport mechanism while decoherent hopping transport is present to a minor extent.}, language = {en} } @article{CapitainRossJonesMoehringetal.2020, author = {Capitain, Charlotte and Ross-Jones, Jesse and M{\"o}hring, Sophie and Tippk{\"o}tter, Nils}, title = {Differential scanning calorimetry for quantification of polymer biodegradability in compost}, series = {International Biodeterioration \& Biodegradation}, volume = {149}, journal = {International Biodeterioration \& Biodegradation}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0964-8305}, doi = {10.1016/j.ibiod.2020.104914}, pages = {In Press, Article number 104914}, year = {2020}, abstract = {The objective of this study is the establishment of a differential scanning calorimetry (DSC) based method for online analysis of the biodegradation of polymers in complex environments. Structural changes during biodegradation, such as an increase in brittleness or crystallinity, can be detected by carefully observing characteristic changes in DSC profiles. Until now, DSC profiles have not been used to draw quantitative conclusions about biodegradation. A new method is presented for quantifying the biodegradation using DSC data, whereby the results were validated using two reference methods. The proposed method is applied to evaluate the biodegradation of three polymeric biomaterials: polyhydroxybutyrate (PHB), cellulose acetate (CA) and Organosolv lignin. The method is suitable for the precise quantification of the biodegradability of PHB. For CA and lignin, conclusions regarding their biodegradation can be drawn with lower resolutions. The proposed method is also able to quantify the biodegradation of blends or composite materials, which differentiates it from commonly used degradation detection methods.}, language = {en} } @article{KnoxBruggemannGossmannetal.2020, author = {Knox, Ronald and Bruggemann, Andrea and Gossmann, Matthias and Thomas, Ulrich and Horv{\´a}th, Andr{\´a}s and Dragicevic, Elena and Stoelzle-Feix, Sonja and Fertig, Niels and Jung, Alexander and Raman, Aravind Hariharan and Staat, Manfred and Linder, Peter}, title = {Combining physiological relevance and throughput for in vitro cardiac contractility measurement}, series = {Biophysical Journal}, volume = {118}, journal = {Biophysical Journal}, number = {Issue 3, Supplement 1}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0006-3495}, doi = {10.1016/j.bpj.2019.11.3104}, pages = {570a}, year = {2020}, abstract = {Despite increasing acceptance of human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) in safety pharmacology, controversy remains about the physiological relevance of existing in vitro models for their mechanical testing. We hypothesize that existing signs of immaturity of the cell models result from an improper mechanical environment. We cultured hiPSC-CMs in a 96-well format on hyperelastic silicone membranes imitating their native mechanical environment, resulting in physiological responses to compound stimuli.We validated cell responses on the FLEXcyte 96, with a set of reference compounds covering a broad range of cellular targets, including ion channel modulators, adrenergic receptor modulators and kinase inhibitors. Acute (10 - 30 min) and chronic (up to 7 days) effects were investigated. Furthermore, the measurements were complemented with electromechanical models based on electrophysiological recordings of the used cell types.hiPSC-CMs were cultured on freely-swinging, ultra-thin and hyperelastic silicone membranes. The weight of the cell culture medium deflects the membranes downwards. Rhythmic contraction of the hiPSC-CMs resulted in dynamic deflection changes which were quantified by capacitive distance sensing. The cells were cultured for 7 days prior to compound addition. Acute measurements were conducted 10-30 minutes after compound addition in standard culture medium. For chronic treatment, compound-containing medium was replaced daily for up to 7 days. Electrophysiological properties of the employed cell types were recorded by automated patch-clamp (Patchliner) and the results were integrated into the electromechanical model of the system.Calcium channel agonist S Bay K8644 and beta-adrenergic stimulator isoproterenol induced significant positive inotropic responses without additional external stimulation. Kinase inhibitors displayed cardiotoxic effects on a functional level at low concentrations. The system-integrated analysis detected alterations in beating shape as well as frequency and arrhythmic events and we provide a quantitative measure of these.}, language = {en} }