@article{RaffeisAdjeiKyeremehVroomenetal.2020, author = {Raffeis, Iris and Adjei-Kyeremeh, Frank and Vroomen, Uwe and Westhoff, Elmar and Bremen, Sebastian and Hohoi, Alexandru and B{\"u}hrig-Polaczek, Andreas}, title = {Qualification of a Ni-Cu alloy for the laser powder bed fusion process (LPBF): Its microstructure and mechanical properties}, series = {Applied Sciences}, volume = {10}, journal = {Applied Sciences}, number = {Art. 3401}, publisher = {MDPI}, address = {Basel}, issn = {2076-3417}, doi = {10.3390/app10103401}, pages = {1 -- 15}, year = {2020}, abstract = {As researchers continue to seek the expansion of the material base for additive manufacturing, there is a need to focus attention on the Ni-Cu group of alloys which conventionally has wide industrial applications. In this work, the G-NiCu30Nb casting alloy, a variant of the Monel family of alloys with Nb and high Si content is, for the first time, processed via the laser powder bed fusion process (LPBF). Being novel to the LPBF processes, optimum LPBF parameters were determined, and hardness and tensile tests were performed in as-built conditions and after heat treatment at 1000 °C. Microstructures of the as-cast and the as-built condition were compared. Highly dense samples (99.8\% density) were achieved after varying hatch distance (80 µm and 140 µm) with scanning speed (550 mm/s-1500 mm/s). There was no significant difference in microhardness between varied hatch distance print sets. Microhardness of the as-built condition (247 HV0.2) exceeded the as-cast microhardness (179 HV0.2.). Tensile specimens built in vertical (V) and horizontal (H) orientations revealed degrees of anisotropy and were superior to conventionally reported figures. Post heat treatment increased ductility from 20\% to 31\% (V), as well as from 16\% to 25\% (H), while ultimate tensile strength (UTS) and yield strength (YS) were considerably reduced.}, language = {en} } @article{ElsenHartungHornetal.2001, author = {Elsen, Ingo and Hartung, Frank and Horn, Uwe and Kampmann, Markus and Peters, Liliane}, title = {Streaming technology in 3G mobile communication systems}, series = {Computer : innovative technology for computer professionals}, volume = {34}, journal = {Computer : innovative technology for computer professionals}, number = {9 Seiten}, editor = {Voas, Jeffrey}, publisher = {IEEE}, address = {New York}, issn = {0018-9162}, pages = {46 -- 52}, year = {2001}, abstract = {Third-generation mobile communication systems will combine standardized streaming with a range of unique services to provide high-quality Internet content that meets the specific needs of the rapidly growing mobile market.}, language = {en} } @inproceedings{ChudobaButenwegPfeiffer2003, author = {Chudoba, Rostislav and Butenweg, Christoph and Pfeiffer, Frank}, title = {Textile reinforced concrete. Part I: Process model for collaborative research and development}, series = {Digital proceedings / IKM 2003, proceedings 16th International Conference on the Applications of Computer Science and Mathematics in Architecture and Civil Engineering [Elektronische Ressource : 10. - 12. Juni 2003, Weimar] / Bauhaus-Universit{\"a}t Weimar. Ed.: K. G{\"u}rlebeck; L. Hempel; C. K{\"o}nke}, booktitle = {Digital proceedings / IKM 2003, proceedings 16th International Conference on the Applications of Computer Science and Mathematics in Architecture and Civil Engineering [Elektronische Ressource : 10. - 12. Juni 2003, Weimar] / Bauhaus-Universit{\"a}t Weimar. Ed.: K. G{\"u}rlebeck; L. Hempel; C. K{\"o}nke}, publisher = {IKM}, address = {Weimar}, organization = {Internationales Kolloquium {\"u}ber Anwendungen der Informatik und Mathematik in Architektur und Bauwesen <16, 2003, Weimar>}, pages = {1 -- 8}, year = {2003}, language = {en} } @article{MoehrenBergmannJanseretal.2023, author = {M{\"o}hren, Felix and Bergmann, Ole and Janser, Frank and Braun, Carsten}, title = {On the influence of elasticity on propeller performance: a parametric study}, series = {CEAS Aeronautical Journal}, volume = {14}, journal = {CEAS Aeronautical Journal}, publisher = {Springer Nature}, address = {Berlin}, issn = {1869-5590 (Online)}, doi = {10.1007/s13272-023-00649-y}, pages = {311 -- 323}, year = {2023}, abstract = {The aerodynamic performance of propellers strongly depends on their geometry and, consequently, on aeroelastic deformations. Knowledge of the extent of the impact is crucial for overall aircraft performance. An integrated simulation environment for steady aeroelastic propeller simulations is presented. The simulation environment is applied to determine the impact of elastic deformations on the aerodynamic propeller performance. The aerodynamic module includes a blade element momentum approach to calculate aerodynamic loads. The structural module is based on finite beam elements, according to Timoshenko theory, including moderate deflections. Several fixed-pitch propellers with thin-walled cross sections made of both isotropic and non-isotropic materials are investigated. The essential parameters are varied: diameter, disc loading, sweep, material, rotational, and flight velocity. The relative change of thrust between rigid and elastic blades quantifies the impact of propeller elasticity. Swept propellers of large diameters or low disc loadings can decrease the thrust significantly. High flight velocities and low material stiffness amplify this tendency. Performance calculations without consideration of propeller elasticity can lead to decreased efficiency. To avoid cost- and time-intense redesigns, propeller elasticity should be considered for swept planforms and low disc loadings.}, language = {en} } @inproceedings{MoehrenBergmannJanseretal.2023, author = {M{\"o}hren, Felix and Bergmann, Ole and Janser, Frank and Braun, Carsten}, title = {On the determination of harmonic propeller loads}, series = {AIAA SCITECH 2023 Forum}, booktitle = {AIAA SCITECH 2023 Forum}, publisher = {AIAA}, doi = {10.2514/6.2023-2404}, pages = {12 Seiten}, year = {2023}, abstract = {Dynamic loads significantly impact the structural design of propeller blades due to fatigue and static strength. Since propellers are elastic structures, deformations and aerodynamic loads are coupled. In the past, propeller manufacturers established procedures to determine unsteady aerodynamic loads and the structural response with analytical steady-state calculations. According to the approach, aeroelastic coupling primarily consists of torsional deformations. They neglect bending deformations, deformation velocities, and inertia terms. This paper validates the assumptions above for a General Aviation propeller and a lift propeller for urban air mobility or large cargo drones. Fully coupled reduced-order simulations determine the dynamic loads in the time domain. A quasi-steady blade element momentum approach transfers loads to one-dimensional finite beam elements. The simulation results are in relatively good agreement with the analytical method for the General Aviation propeller but show increasing errors for the slender lift propeller. The analytical approach is modified to consider the induced velocities. Still, inertia and velocity proportional terms play a significant role for the lift propeller due to increased elasticity. The assumption that only torsional deformations significantly impact the dynamic loads of propellers is not valid. Adequate determination of dynamic loads of such designs requires coupled aeroelastic simulations or advanced analytical procedures.}, language = {en} } @book{EngelnMuellgesUhlig1996, author = {Engeln-M{\"u}llges, Gisela and Uhlig, Frank}, title = {Numerical algorithms with C}, publisher = {Springer}, address = {Berlin [u.a.]}, isbn = {3-540-60530-0}, pages = {XXII, 596 S. : graph. Darst. + 1 CD-ROM}, year = {1996}, language = {en} } @book{EngelnMuellgesUhlig1996, author = {Engeln-M{\"u}llges, Gisela and Uhlig, Frank}, title = {Numeric Algorithms with Fortran}, publisher = {Springer}, address = {Berlin [u.a.]}, isbn = {3-540-60529-0}, pages = {XXII, 602 S. : Ill., graph. Darst. + 1 CD-ROM}, year = {1996}, language = {en} } @article{FerreinDyllaLakemeyeretal.2008, author = {Ferrein, Alexander and Dylla, Frank and Lakemeyer, Gerhard and Murray, Jan}, title = {Approaching a formal soccer theory from behaviour specifications in robotic soccer / Dylla, Frank ; Ferrein, Alexander ; Lakemeyer, Gerhard ; Murray, Jan ; Obst, Oliver ; R{\"o}fer, Thomas ; Schiffer, Stefan ; Stolzenburg, Frieder ; Visser, Ubbo ; Wagner, Tho}, series = {Computers in sport / editors: P Dabnichki}, journal = {Computers in sport / editors: P Dabnichki}, publisher = {WIT Press}, address = {Southampton}, isbn = {978-1-8456-4064-4}, pages = {161 -- 185}, year = {2008}, language = {en} } @inproceedings{WaldmannVeraDachwaldetal.2018, author = {Waldmann, Christoph and Vera, Jean-Pierre de and Dachwald, Bernd and Strasdeit, Henry and Sohl, Frank and Hanff, Hendrik and Kowalski, Julia and Heinen, Dirk and Macht, Sabine and Bestmann, Ulf and Meckel, Sebastian and Hildebrandt, Marc and Funke, Oliver and Gehrt, Jan-J{\"o}ran}, title = {Search for life in ice-covered oceans and lakes beyond Earth}, series = {2018 IEEE/OES Autonomous Underwater Vehicle Workshop, Proceedings November 2018, Article number 8729761}, booktitle = {2018 IEEE/OES Autonomous Underwater Vehicle Workshop, Proceedings November 2018, Article number 8729761}, doi = {10.1109/AUV.2018.8729761}, year = {2018}, abstract = {The quest for life on other planets is closely connected with the search for water in liquid state. Recent discoveries of deep oceans on icy moons like Europa and Enceladus have spurred an intensive discussion about how these waters can be accessed. The challenge of this endeavor lies in the unforeseeable requirements on instrumental characteristics both with respect to the scientific and technical methods. The TRIPLE/nanoAUV initiative is aiming at developing a mission concept for exploring exo-oceans and demonstrating the achievements in an earth-analogue context, exploring the ocean under the ice shield of Antarctica and lakes like Dome-C on the Antarctic continent.}, language = {en} } @masterthesis{Frank2022, type = {Bachelor Thesis}, author = {Frank, Jemima Leonie}, title = {Falling in love with the female gaze}, publisher = {FH Aachen}, address = {Aachen}, school = {Fachhochschule Aachen}, pages = {81 Seiten}, year = {2022}, abstract = {Der „Male Gaze" bezeichnet das typische Erleben der Umwelt aus m{\"a}nnlicher Perspektive und pr{\"a}gt in den sogenannten Mainstream-Medien die Gestaltung von Film, Fernsehen und Werbung. Dadurch werden von dargestellten Personen h{\"a}ufig die k{\"o}rperlichen Aspekte hervorgehoben. Im Gegensatz dazu gilt das weibliche Pendant, der „Female Gaze", als besonders emotionsbetont. Weil Medien einen enormen Einfluss auf gesellschaftliches und individuelles Denken haben, stellt die Dominanz des „Male Gaze" eine Unausgeglichenheit dar, die sich in verschiedenen Bereichen des gesellschaftlichen Lebens widerspiegelt. Deswegen m{\"o}chte dieses Projekt die Medien um die weibliche Sichtweise erweitern und damit die dort transportierten Bilder diverser und ausgewogener machen. Die Fotografie fokussiert sich dabei auf die Gef{\"u}hlswelt der Protagonistin, womit die Betrachter:Innen schrittweise in ihre Position hineinversetzt werden sollen. Mit Augen des Mitgef{\"u}hls und eigenem Sch{\"o}nheitsbegriff l{\"a}sst „Falling in love with the female gaze" endlich auch die Frau zu Wort kommen.}, language = {de} } @incollection{KurzZebner2011, author = {Kurz, Melanie and Zebner, Frank}, title = {Zum Verh{\"a}ltnis von Design und Technik}, series = {Design, Anfang des 21 Jh. : Diskurse und Perspektiven}, booktitle = {Design, Anfang des 21 Jh. : Diskurse und Perspektiven}, editor = {Eisele, Petra and B{\"u}rdek, Bernhard E.}, publisher = {avedition}, address = {Ludwigsburg}, isbn = {978-3-89986-150-1}, pages = {174 -- 185}, year = {2011}, language = {de} } @article{SaretzkiBergmannDahmannetal.2021, author = {Saretzki, Charlotte and Bergmann, Ole and Dahmann, Peter and Janser, Frank and Keimer, Jona and Machado, Patricia and Morrison, Audry and Page, Henry and Pluta, Emil and St{\"u}bing, Felix and K{\"u}pper, Thomas}, title = {Are small airplanes safe with regards to COVID-19 transmission?}, series = {Journal of Travel Medicine}, volume = {28}, journal = {Journal of Travel Medicine}, number = {7}, publisher = {Oxford University Press}, address = {Oxford}, issn = {1708-8305}, doi = {10.1093/jtm/taab105}, year = {2021}, language = {en} } @misc{LindelGreiserWaxmanetal.2012, author = {Lindel, Tomasz Dawid and Greiser, Andreas and Waxman, Patrick and Dietterle, Martin and Seifert, Frank and Fontius, Ulrich and Renz, Wolfgang and Dieringer, Matthias A. and Frauenrath, Tobias and Schulz-Menger, Jeanette and Niendorf, Thoralf and Ittermann, Bernd}, title = {Cardiac CINE MRI at 7 T using a transmit array}, series = {2012 ISMRM Annual Meeting Proceedings}, journal = {2012 ISMRM Annual Meeting Proceedings}, issn = {1545-4428}, year = {2012}, abstract = {With its need for high SNR and short acquisition times, Cardiac MRI (CMR) is an intriguing target application for ultrahigh field MRI. Due to the sheer size of the upper torso, however, the known RF issues of 7T MRI are also most prominent in CMR. Recent years brought substantial progress but the full potential of the ultrahigh field for CMR is yet to be exploited. Parallel transmission (pTx) is a promising approach in this context and several groups have already reported B1 shimming for 7T CMR. In such a static pTx application amplitudes and phases of all Tx channels are adjusted individually but otherwise imaging techniques established in current clinical practice 1.5 T and 3 T are applied. More advanced forms of pTx as spatially selective excitation (SSE) using Transmit SENSE promise additional benefits like faster imaging with reduced fields of view or improved SAR control. SSE requires the full dynamic capabilities of pTx, however, and for the majority of today's implemented pTx hardware the internal synchronization of the Tx array does not easily permit external triggering as needed for CMR. Here we report a software solution to this problem and demonstrate the feasibility of CINE CMR at 7 T using a Tx array.}, language = {en} } @article{WeemstraEilmannSassKlaassenetal.2013, author = {Weemstra, Monique and Eilmann, Britta and Sass-Klaassen, Ute G. W. and Sterck, Frank J.}, title = {Summer droughts limit tree growth across 10 temperate species on a productive forest site}, series = {Forest Ecology and Management}, volume = {2013}, journal = {Forest Ecology and Management}, number = {306}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0378-1127 (Print)}, doi = {doi:10.1016/j.foreco.2013.06.007}, pages = {142 -- 149}, year = {2013}, language = {en} } @book{GunnarBartonBeigeletal.2017, author = {Gunnar, Auth and Barton, Thomas and Beigel, Stefan and Bensberg, Frank and Brehm, Lars and Wolf, Martin R.}, title = {Prozesse, Technologie, Anwendungen, Systeme und Management 2017}, editor = {Barton, Thomas and Herrmann, Frank and Meister, Vera G. and M{\"u}ller, Christian and Seel, Christian}, publisher = {Mana-Buch}, address = {Heide}, isbn = {978-3-944330-56-3}, pages = {297 Seiten}, year = {2017}, language = {de} } @article{DieringerRenzLindeletal.2011, author = {Dieringer, Matthias A. and Renz, Wolfgang and Lindel, Tomasz D. and Seifert, Frank and Frauenrath, Tobias and von Knobelsdorf-Brenkenhoff, Florian and Waiczies, Helmar and Hoffmann, Werner and Rieger, Jan and Pfeiffer, Harald and Ittermann, Bernd and Schulz-Menger, Jeanette and Niendorf, Thoralf}, title = {Design and application of a four-channel transmit/receive surface coil for functional cardiac imaging at 7T}, series = {Journal of Magnetic Resonance Imaging}, volume = {33}, journal = {Journal of Magnetic Resonance Imaging}, number = {3}, publisher = {Wiley-Liss}, address = {New York}, issn = {1522-2586}, doi = {10.1002/jmri.22451}, pages = {736 -- 741}, year = {2011}, abstract = {Purpose To design and evaluate a four-channel cardiac transceiver coil array for functional cardiac imaging at 7T. Materials and Methods A four-element cardiac transceiver surface coil array was developed with two rectangular loops mounted on an anterior former and two rectangular loops on a posterior former. specific absorption rate (SAR) simulations were performed and a Burn:x-wiley:10531807:media:JMRI22451:tex2gif-stack-1 calibration method was applied prior to obtain 2D FLASH CINE (mSENSE, R = 2) images from nine healthy volunteers with a spatial resolution of up to 1 × 1 × 2.5 mm3. Results Tuning and matching was found to be better than 10 dB for all subjects. The decoupling (S21) was measured to be >18 dB between neighboring loops, >20 dB for opposite loops, and >30 dB for other loop combinations. SAR values were well within the limits provided by the IEC. Imaging provided clinically acceptable signal homogeneity with an excellent blood-myocardium contrast applying the Burn:x-wiley:10531807:media:JMRI22451:tex2gif-stack-2 calibration approach. Conclusion A four-channel cardiac transceiver coil array for 7T was built, allowing for cardiac imaging with clinically acceptable signal homogeneity and an excellent blood-myocardium contrast. Minor anatomic structures, such as pericardium, mitral, and tricuspid valves and their apparatus, as well as trabeculae, were accurately delineated.}, language = {en} } @inproceedings{HammerViethMaier2005, author = {Hammer, Andreas and Vieth, Matthias and Maier, Frank}, title = {Co-Plot as a new multivariate analysis method for operations management research?}, series = {Papers of the 12th International EurOMA Conference on Operational and Global Competitiveness, Budapest, Hungary, June 19-22, 2005 / Editor: Krisztina Demeter}, booktitle = {Papers of the 12th International EurOMA Conference on Operational and Global Competitiveness, Budapest, Hungary, June 19-22, 2005 / Editor: Krisztina Demeter}, isbn = {963-218-455-6}, pages = {1007 -- 1016}, year = {2005}, language = {en} } @article{EilmannSterckWegneretal.2014, author = {Eilmann, Britta and Sterck, Frank J. and Wegner, L. and de Vries, Sven M. G. and von Arx, G. and Mohren, Godefridus M. J. and den Ouden, Jan and Sass-Klaassen, Ute G. W.}, title = {Wood structural differences between northern and southern beech provenances growing at a moderate site}, series = {Tree Physiology}, volume = {34}, journal = {Tree Physiology}, number = {8}, publisher = {Oxford University Press}, address = {Oxford}, issn = {1758-4469 (Online)}, doi = {10.1093/treephys/tpu069}, pages = {882 -- 893}, year = {2014}, language = {en} } @inproceedings{HansenLaack2018, author = {Hansen, Frank and Laack, Walter van}, title = {Schnittstelle Tod: Sind Religionen religi{\"o}s und Wissenschaften wissend?}, publisher = {van Laack GmbH}, address = {Aachen}, isbn = {978-3-936624-36-6}, pages = {172 S.}, year = {2018}, language = {de} } @inproceedings{WolfBartonHerrmannetal.2019, author = {Wolf, Martin R. and Barton, Thomas and Herrmann, Frank and Meister, Vera G. and M{\"u}ller, Christian and Seel, Christian}, title = {Angewandte Forschung in der Wirtschaftsinformatik 2019 : Tagungsband zur 32. AKWI-Jahrestagung vom 15.09.2019 bis 18.09.2019 an der Fachhochschule f{\"u}r Angewandte Wissenschaften Aachen / hrsg. von Martin R. Wolf, Thomas Barton, Frank Herrmann, Vera G. Meister, Christian M{\"u}ller, Christian Seel}, publisher = {mana-Buch}, address = {Heide}, isbn = {978-3-944330-62-4}, doi = {10.15771/978-3-944330-62-4}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:526-opus4-13026}, pages = {261 Seiten}, year = {2019}, abstract = {Tagungsbeitr{\"a}ge aus den Bereichen Projektmanagement, Didaktik in der Wirtschaftsinformatik, IT-Sicherheit, Anwendungsf{\"a}lle, Reifegradmodelle, Plattformen f{\"u}r Gesch{\"a}ftsprozesse und Prototypen.}, language = {de} }