TY - JOUR A1 - Choi, Chang-Hoon A1 - Felder, Tim A1 - Felder, Jörg A1 - Tellmann, Lutz A1 - Hong, Suk-Min A1 - Wegener, Hans-Peter A1 - Shah, N Jon A1 - Ziemons, Karl T1 - Design, evaluation and comparison of endorectal coils for hybrid MR-PET imaging of the prostate JF - Physics in Medicine & Biology N2 - Prostate cancer is one of the most common cancers among men and its early detection is critical for its successful treatment. The use of multimodal imaging, such as MR-PET, is most advantageous as it is able to provide detailed information about the prostate. However, as the human prostate is flexible and can move into different positions under external conditions, it is important to localise the focused region-of-interest using both MRI and PET under identical circumstances. In this work, we designed five commonly used linear and quadrature radiofrequency surface coils suitable for hybrid MR-PET use in endorectal applications. Due to the endorectal design and the shielded PET insert, the outer face of the coils investigated was curved and the region to be imaged was outside the volume of the coil. The tilting angles of the coils were varied with respect to the main magnetic field direction. This was done to approximate the various positions from which the prostate could be imaged. The transmit efficiencies and safety excitation efficiencies from simulations, together with the signal-to-noise ratios from the MR images were calculated and analysed. Overall, it was found that the overlapped loops driven in quadrature were superior to the other types of coils we tested. In order to determine the effect of the different coil designs on PET, transmission scans were carried out, and it was observed that the differences between attenuation maps with and without the coils were negligible. The findings of this work can provide useful guidance for the integration of such coil designs into MR-PET hybrid systems in the future. Y1 - 2020 U6 - http://dx.doi.org/10.1088/1361-6560/ab87f8 SN - 0031-9155 VL - 65 IS - 11 PB - IOP CY - Bristol ER - TY - JOUR A1 - Franko, Josef A1 - Du, Shengzhi A1 - Kallweit, Stephan A1 - Duelberg, Enno Sebastian A1 - Engemann, Heiko T1 - Design of a Multi-Robot System for Wind Turbine Maintenance JF - Energies N2 - The maintenance of wind turbines is of growing importance considering the transition to renewable energy. This paper presents a multi-robot-approach for automated wind turbine maintenance including a novel climbing robot. Currently, wind turbine maintenance remains a manual task, which is monotonous, dangerous, and also physically demanding due to the large scale of wind turbines. Technical climbers are required to work at significant heights, even in bad weather conditions. Furthermore, a skilled labor force with sufficient knowledge in repairing fiber composite material is rare. Autonomous mobile systems enable the digitization of the maintenance process. They can be designed for weather-independent operations. This work contributes to the development and experimental validation of a maintenance system consisting of multiple robotic platforms for a variety of tasks, such as wind turbine tower and rotor blade service. In this work, multicopters with vision and LiDAR sensors for global inspection are used to guide slower climbing robots. Light-weight magnetic climbers with surface contact were used to analyze structure parts with non-destructive inspection methods and to locally repair smaller defects. Localization was enabled by adapting odometry for conical-shaped surfaces considering additional navigation sensors. Magnets were suitable for steel towers to clamp onto the surface. A friction-based climbing ring robot (SMART— Scanning, Monitoring, Analyzing, Repair and Transportation) completed the set-up for higher payload. The maintenance period could be extended by using weather-proofed maintenance robots. The multi-robot-system was running the Robot Operating System (ROS). Additionally, first steps towards machine learning would enable maintenance staff to use pattern classification for fault diagnosis in order to operate safely from the ground in the future. Y1 - 2020 U6 - http://dx.doi.org/10.3390/en13102552 SN - 1996-1073 VL - 13 IS - 10 SP - Article 2552 PB - MDPI CY - Basel ER - TY - CHAP A1 - Elgamal, Abdelrahman A1 - Heuermann, Holger T1 - Design and Development of a Hot S-Parameter Measurement System for Plasma and Magnetron Applications T2 - 2020 German Microwave Conference (GeMiC), Cottbus, Germany, 2020 Y1 - 2020 SN - 978-3-9820397-1-8 SP - 124 EP - 127 ER - TY - JOUR A1 - Digel, Ilya A1 - Kern, Inna A1 - Geenen, Eva-Maria A1 - Akimbekov, Nuraly T1 - Dental plaque removal by ultrasonic toothbrushes JF - dentistry journal N2 - 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. Y1 - 2020 U6 - http://dx.doi.org/10.3390/dj8010028 SN - 2304-6767 VL - 8 IS - 28 SP - 1 EP - 13 PB - MDPI CY - Basel ER - TY - JOUR A1 - Malan, Leone A1 - Hamer, Mark A1 - Känel, Roland von A1 - Kotliar, Konstantin A1 - Wyk, Roelof D. van A1 - Lambert, Gavin W. A1 - Vilser, Walthard A1 - Ziemssen, Tjalf A1 - Schlaich, Markus P. A1 - Smith, Wayne A1 - Magnusson, Martin A1 - Wentzel, Annemarie A1 - Myburgh, Carlien E. A1 - Steyn, Hendrik S. A1 - Malan, Nico T. T1 - Delayed retinal vein recovery responses indicate both non-adaptation to stress as well as increased risk for stroke: the SABPA study JF - Cardiovascular Journal of Africa Y1 - 2020 U6 - http://dx.doi.org/10.5830/CVJA-2020-031 SN - 1680-0745 VL - 26 IS - 31 SP - 1 EP - 12 PB - Clinics Cardive Publishing CY - Durbanville ER - TY - JOUR A1 - Golland, Alexander T1 - Datenschutzrechtliche Fragen personalisierter Preise — Herausforderungen von Algorithmen im Schnittbereich von Ethik, Ökonomie und Datenschutz JF - CR Computer und Recht Y1 - 2020 SN - 2194-4172 U6 - http://dx.doi.org/10.9785/cr-2020-360313 VL - 36 IS - 3 SP - 186 EP - 194 PB - Verlag Dr. Otto Schmidt CY - Köln ER - TY - JOUR A1 - Golland, Alexander T1 - Datenschutzrechtliche Anforderungen an internationale Datentransfers JF - NJW - Neue Juristische Wochenschrift Y1 - 2020 SN - 0341-1915 N1 - Zugleich Anmerkung zu EuGH, Urteil vom 16.7.2020 (C-311/18) VL - 2020 IS - 36 SP - 2593 EP - 2596 PB - Beck CY - München ER - TY - GEN A1 - Ohrtmann, Jan-Peter A1 - Golland, Alexander T1 - Daten- und Privatsphäreschutz im Wandel der 2020er-Jahre Y1 - 2020 SP - 33 EP - 38 ER - TY - CHAP A1 - Paulsen, Svea A1 - Hoffstadt, Kevin A1 - Krafft, Simone A1 - Leite, A. A1 - Zang, J. A1 - Fonseca-Zang, W. A1 - Kuperjans, Isabel T1 - Continuous biogas production from sugarcane as sole substrate T2 - Energy Reports Y1 - 2020 U6 - http://dx.doi.org/10.1016/j.egyr.2019.08.035 N1 - 6th International Conference on Energy and Environment Research, ICEER 2019, 22–25 July, University of Aveiro, Portugal VL - 6 IS - Supplement 1 SP - 153 EP - 158 PB - Elsevier ER - TY - CHAP A1 - Leise, Philipp A1 - Simon, Nicolai A1 - Altherr, Lena T1 - Comparison of Piecewise Linearization Techniques to Model Electric Motor Efficiency Maps: A Computational Study T2 - Operations Research Proceedings 2019 N2 - To maximize the travel distances of battery electric vehicles such as cars or buses for a given amount of stored energy, their powertrains are optimized energetically. One key part within optimization models for electric powertrains is the efficiency map of the electric motor. The underlying function is usually highly nonlinear and nonconvex and leads to major challenges within a global optimization process. To enable faster solution times, one possibility is the usage of piecewise linearization techniques to approximate the nonlinear efficiency map with linear constraints. Therefore, we evaluate the influence of different piecewise linearization modeling techniques on the overall solution process and compare the solution time and accuracy for methods with and without explicitly used binary variables. KW - MINLP KW - Powertrain KW - Piecewise linearization KW - Efficiency optimization Y1 - 2020 SN - 978-3-030-48439-2 SN - 978-3-030-48438-5 U6 - http://dx.doi.org/10.1007/978-3-030-48439-2_55 N1 - Annual International Conference of the German Operations Research Society (GOR), Dresden, Germany, September 4-6, 2019 SP - 457 EP - 463 PB - Springer CY - Cham ER -