@article{Staat2021, author = {Staat, Manfred}, title = {An extension strain type Mohr-Coulomb criterion}, series = {Rock mechanics and rock engineering}, volume = {54}, journal = {Rock mechanics and rock engineering}, number = {12}, publisher = {Springer Nature}, address = {Cham}, issn = {1434-453X}, doi = {10.1007/s00603-021-02608-7}, pages = {6207 -- 6233}, year = {2021}, abstract = {Extension fractures are typical for the deformation under low or no confining pressure. They can be explained by a phenomenological extension strain failure criterion. In the past, a simple empirical criterion for fracture initiation in brittle rock has been developed. In this article, it is shown that the simple extension strain criterion makes unrealistic strength predictions in biaxial compression and tension. To overcome this major limitation, a new extension strain criterion is proposed by adding a weighted principal shear component to the simple criterion. The shear weight is chosen, such that the enriched extension strain criterion represents the same failure surface as the Mohr-Coulomb (MC) criterion. Thus, the MC criterion has been derived as an extension strain criterion predicting extension failure modes, which are unexpected in the classical understanding of the failure of cohesive-frictional materials. In progressive damage of rock, the most likely fracture direction is orthogonal to the maximum extension strain leading to dilatancy. The enriched extension strain criterion is proposed as a threshold surface for crack initiation CI and crack damage CD and as a failure surface at peak stress CP. Different from compressive loading, tensile loading requires only a limited number of critical cracks to cause failure. Therefore, for tensile stresses, the failure criteria must be modified somehow, possibly by a cut-off corresponding to the CI stress. Examples show that the enriched extension strain criterion predicts much lower volumes of damaged rock mass compared to the simple extension strain criterion.}, language = {en} } @article{PoghossianWeldenBuniatyanetal.2021, author = {Poghossian, Arshak and Welden, Rene and Buniatyan, Vahe V. and Sch{\"o}ning, Michael Josef}, title = {An Array of On-Chip Integrated, Individually Addressable Capacitive Field-Effect Sensors with Control Gate: Design and Modelling}, series = {Sensors}, volume = {21}, journal = {Sensors}, number = {18}, publisher = {MDPI}, address = {Basel}, issn = {1424-8220}, doi = {10.3390/s21186161}, pages = {17}, year = {2021}, abstract = {The on-chip integration of multiple biochemical sensors based on field-effect electrolyte-insulator-semiconductor capacitors (EISCAP) is challenging due to technological difficulties in realization of electrically isolated EISCAPs on the same Si chip. In this work, we present a new simple design for an array of on-chip integrated, individually electrically addressable EISCAPs with an additional control gate (CG-EISCAP). The existence of the CG enables an addressable activation or deactivation of on-chip integrated individual CG-EISCAPs by simple electrical switching the CG of each sensor in various setups, and makes the new design capable for multianalyte detection without cross-talk effects between the sensors in the array. The new designed CG-EISCAP chip was modelled in so-called floating/short-circuited and floating/capacitively-coupled setups, and the corresponding electrical equivalent circuits were developed. In addition, the capacitance-voltage curves of the CG-EISCAP chip in different setups were simulated and compared with that of a single EISCAP sensor. Moreover, the sensitivity of the CG-EISCAP chip to surface potential changes induced by biochemical reactions was simulated and an impact of different parameters, such as gate voltage, insulator thickness and doping concentration in Si, on the sensitivity has been discussed.}, language = {en} } @masterthesis{Anders2021, type = {Bachelor Thesis}, author = {Anders, Milena}, title = {Alternative Landwirtschaft - Wo kommt unser Essen her?}, publisher = {FH Aachen}, address = {Aachen}, school = {Fachhochschule Aachen}, pages = {79 Seiten}, year = {2021}, abstract = {In den letzten 1.5 Jahren haben wir sehr deutlich gemerkt, dass es den Klimawandel wirklich gibt - ein Virus, welches unsere gesamte Welt auf links dreht, {\"U}berschwemmungskatastrophen, extreme Temperaturschwankungen, etc. Es ist also Zeit etwas zu ver{\"a}ndern, es ist Zeit aktiv hinzusehen und zu handeln - bewusst zu leben, bewusst zu konsumieren. Das Thema Ern{\"a}hrung wird zwar immer wichtiger f{\"u}r einige von uns, jedoch reicht mir die Aufmerksamkeit bisher nicht. Es sind nicht nur Lebensmittel, welche nach dem Aufenthalt im Supermarkt in unserem K{\"u}hlschrank und anschließend in unserem Bauch landen. Mit diesen Lebensmitteln gehen außerdem folgende Aspekte einher: der Klimawandel, unsere Gesundheit, die Ausbeutung von Tieren, Menschen und Natur. Also wie sieht eigentlich der Enstehungsprozess hinter all diesen (meist) verpackten Lebensmitteln aus? Einen Teil dieser Prozesse habe ich mir im Rahmen meiner Bachelorarbeit angeschaut. Ich habe ausschließlich Bio-H{\"o}fe besucht, um mir ein eigenes Bild von "alternativer Landwirtschaft" zu machen. Die Arbeit erm{\"o}glicht Interessierten einen neutralen Einblick hinter die Kulisse unserer Lebensmittel und schafft eine Anregung f{\"u}r einen bewussteren Konsum.}, language = {de} } @article{Maurischat2021, author = {Maurischat, Andreas}, title = {Algebraic independence of the Carlitz period and its hyperderivatives}, pages = {1 -- 12}, year = {2021}, language = {en} } @article{GoettenHavermannBraunetal.2021, author = {G{\"o}tten, Falk and Havermann, Marc and Braun, Carsten and Marino, Matthew and Bil, Cees}, title = {Aerodynamic Investigations of UAV Sensor Turrets - A Combined Wind-tunnel and CFD Approach}, series = {SciTech 2021, AIAA SciTech Forum, online, WW, Jan 11-15, 2021}, journal = {SciTech 2021, AIAA SciTech Forum, online, WW, Jan 11-15, 2021}, publisher = {AIAA}, address = {Reston, Va.}, doi = {10.2514/6.2021-1535}, pages = {1 -- 12}, year = {2021}, language = {en} } @misc{MayntzKeimerTegtmeyeretal.2021, author = {Mayntz, Joscha and Keimer, Jona and Tegtmeyer, Philipp and Dahmann, Peter and Hille, Sebastian and Stumpf, Eike and Fisher, Alex and Dorrington, Graham}, title = {Aerodynamic Investigation on Efficient Inflight Transition of a Propeller from Propulsion to Regeneration Mode}, series = {AIAA SCITECH 2022 Forum}, journal = {AIAA SCITECH 2022 Forum}, publisher = {AIAA}, address = {Reston, Va.}, doi = {10.2514/6.2022-0546}, year = {2021}, abstract = {This paper discusses a new way of inflight power regeneration for electric or hybrid-electric driven general aviation aircraft with one powertrain for both configurations. Three different approaches for the shift from propulsion to regeneration mode are analyzed. Numerical cal-culation and wind tunnel results are compared and show the highest regeneration potential for the "Windmill" approach, where the propeller blades are flipped, and rotation is reversed. A combination of all regeneration approaches for a realistic flight mission is discussed.}, language = {en} } @inproceedings{UlmerBraunWollert2021, author = {Ulmer, Jessica and Braun, Sebastian and Wollert, J{\"o}rg}, title = {Adaptive VR-Produktionsumgebungen f{\"u}r Evaluations- und Schulungst{\"a}tigkeiten}, series = {Automation 2021: Navigating towards resilient Production}, booktitle = {Automation 2021: Navigating towards resilient Production}, publisher = {VDI}, address = {D{\"u}sseldorf}, isbn = {978-3-18-092392-5}, issn = {0083-5560}, doi = {10.51202/9783181023921-55}, pages = {55 -- 64}, year = {2021}, abstract = {Industrie 4.0 stellt viele Herausforderungen an produzierende Unternehmen und ihre Besch{\"a}f-tigten. Innovative und effektive Trainingsstrategien sind erforderlich, um mit den sich schnell ver{\"a}ndernden Produktionsumgebungen und neuen Fertigungstechnologien Schritt halten zu k{\"o}nnen. Virtual Reality (VR) bietet neue M{\"o}glichkeiten f{\"u}r On-the-Job, On-Demand- und Off-Premise-Schulungen. Diese Arbeit stellt ein neues VR Schulungssystem vor, welches sich flexible an unterschiedliche Trainingsobjekte auf Grundlage von Rezepten und CAD Modellen anpassen l{\"a}sst. Das Konzept basiert auf gerichteten azyklischen Graphen und einem Level-system. Es erm{\"o}glicht eine benutzerindividuelle Lerngeschwindigkeit mittels visueller Ele-mente. Das Konzept wurde f{\"u}r einen mechanischen Anwendungsfall mit Industriekomponen-ten implementiert und in der Industrie 4.0-Modellfabrik der FH Aachen umgesetzt.}, language = {de} } @inproceedings{UlmerBraunChengetal.2021, author = {Ulmer, Jessica and Braun, Sebastian and Cheng, Chi-Tsun and Dowey, Steve and Wollert, J{\"o}rg}, title = {Adapting augmented reality systems to the users' needs using gamification and error solving methods}, series = {Procedia CIRP - 54th CIRP CMS 2021 - Towards Digitalized Manufacturing 4.0}, volume = {104}, booktitle = {Procedia CIRP - 54th CIRP CMS 2021 - Towards Digitalized Manufacturing 4.0}, publisher = {Elsevier}, address = {Amsterdam}, issn = {2212-8271}, doi = {10.1016/j.procir.2021.11.024}, pages = {140 -- 145}, year = {2021}, abstract = {Animations of virtual items in AR support systems are typically predefined and lack interactions with dynamic physical environments. AR applications rarely consider users' preferences and do not provide customized spontaneous support under unknown situations. This research focuses on developing adaptive, error-tolerant AR systems based on directed acyclic graphs and error resolving strategies. Using this approach, users will have more freedom of choice during AR supported work, which leads to more efficient workflows. Error correction methods based on CAD models and predefined process data create individual support possibilities. The framework is implemented in the Industry 4.0 model factory at FH Aachen.}, language = {en} } @masterthesis{Niedermeier2021, type = {Bachelor Thesis}, author = {Niedermeier, Jacqueline}, title = {Aachener Tierpark Euregiozoo: Corporate Design f{\"u}r eine Institution mit Bildungsauftrag}, publisher = {FH Aachen}, address = {Aachen}, school = {Fachhochschule Aachen}, pages = {107 Seiten}, year = {2021}, abstract = {Der Aachener Tierpark Euregiozoo l{\"a}sst die Aspekte "Bildung" und "Forschung" mit "Erholung" und "Erhaltung" an einem Ort miteinander verschmelzen. Auf einer Fl{\"a}che von rund 8,9 ha beherbergt der Zoo etwa 1.000 Tiere aus 200 verschiedenen Arten und Rassen in großz{\"u}gigen und nat{\"u}rlich gestalteten Gehegen. Das neue Designkonzept soll den Bildungsaspekt in den Vordergrund r{\"u}cken und modernisieren. Der Einsatz verschiedenster Medien soll die breite Zielgruppe von Jung bis Alt ansprechen und das Interesse nach neuem Wissen anregen. Das neue Leitsystem sorgt nicht nur f{\"u}r Orientierung im Park, es erm{\"o}glicht auch interaktive und individuelle F{\"u}hrungen durch den Zoo. Kombiniert mit einem Wissensquiz und zahlreichen spannenden Fakten {\"u}ber die Tierwelt des Parks wird der Zoobesuch zu einem ganz besonderen Erlebnis.}, language = {de} } @book{TruempenerPetersHerzeletal.2021, author = {Tr{\"u}mpener, Nora and Peters, Jan and Herzel, Manuel and Vollmann, Alina and Breuer, Gina}, title = {Aachener Online-Schriften Wirtschaft und Recht. Band 3/2021}, editor = {Kroll-Ludwigs, Kathrin and Bassen-Metz, Yasmine and Eggert, Mathias and Fritz, Thomas and H{\"o}hne, Tim and Tran, Duc Hung and Vogt, J{\"u}rgen}, publisher = {FH Aachen / Fachbereich Wirtschaftswissenschaften}, address = {Aachen}, publisher = {Fachhochschule Aachen}, pages = {304 Seiten}, year = {2021}, abstract = {Inhaltsverzeichnis 1. Die ordentliche K{\"u}ndigung chronisch Kranker im Anwendungsbereich des KSchG - Nora Tr{\"u}mpener 3-56 2. Die Legitimationswirkung der Gesellschafterliste - Erfolg trotz Grenzen? - Jan Peters 57-112 3. Marktmanipulation - Arten, Abgrenzung und gesetzliche Handhabe - Manuel Herzel 113-170 4. Die Zul{\"a}ssigkeit der Verdachtsk{\"u}ndigung im Arbeitsverh{\"a}ltnis - Alina Vollmann 171-248 5. Praxisorientierter Arbeitgeberleitfaden zur rechtssicheren Einf{\"u}hrung von Homeoffice im Arbeitsverh{\"a}ltnis - Gina Breuer 249-304}, language = {de} }