@masterthesis{Eichler2024, type = {Bachelor Thesis}, author = {Eichler, Sophie}, title = {Digitales Arztpraxis Management}, publisher = {FH Aachen}, address = {Aachen}, school = {Fachhochschule Aachen}, pages = {139 Seiten}, year = {2024}, abstract = {Das Ziel der digitalen Arztpraxis-Management-App „PraXma" ist es, die Organisation von Arztpraxen, sowie auch das Patient:innen- und Terminmanagement einer Praxis effizienter und reibungsloser zu gestalten. Da 83 Prozent der Patient:innen bei der Digitalisierung des deutschen Gesundheitswesens Nachholbedarf sehen, besteht ein erheblicher Bedarf an Weiterentwicklung in dieser Branche. „PraXma" gew{\"a}hrleistet Patient:innen mithilfe verschiedener Funktionen einen angenehmeren Arztbesuch. Dazu z{\"a}hlen die patientenorientierte Terminvergabe, der kategorisierte {\"U}berblick {\"u}ber Vitalwerte und P{\"a}sse und die Einsicht in pers{\"o}nliche Dokumente, wie Befunde, Rezepte und mehr. Auch {\"A}rzt:innen profitieren durch „PraXma" von einer Automatisierung ihrer allt{\"a}glichen Abl{\"a}ufe und minimieren so {\"U}berstunden und Stress.}, language = {de} } @masterthesis{Erkens2024, type = {Bachelor Thesis}, author = {Erkens, Cedric}, title = {En(Joy)Chroma : Entwicklung einer medien{\"u}bergreifenden Werbekampagne f{\"u}r den Brillenhersteller EnChroma}, publisher = {FH Aachen}, address = {Aachen}, school = {Fachhochschule Aachen}, pages = {133 Seiten}, year = {2024}, abstract = {Weltweit sind 350 Millionen Menschen von Farbenfehlsichtigkeit betroffen, doch nur wenige wissen, dass es eine L{\"o}sung f{\"u}r genau dieses Problem gibt. Die ausgearbeitete Werbekampagne und neue Markenkommunikation f{\"u}r EnChroma soll genau diese Menschen ermutigen, sich mit ihrer Krankheit auseinanderzusetzen und das breite Konzept der L{\"o}sung zu verstehen. Die speziellen Brillen erm{\"o}glichen es den Menschen, Farben im Alltag und Berufsleben in echt wahrzunehmen und diese besser differenzieren zu k{\"o}nnen. Unsere Welt ist farbcodiert und deshalb ist es besonders wichtig, dass diese Menschen auf das Produkt aufmerksam gemacht werden.}, language = {de} } @masterthesis{Fleischer2024, type = {Bachelor Thesis}, author = {Fleischer, Rebekka}, title = {Bringing brand experience to marketplaces : ein Online-Marktplatz, der Konsument und Marke verbindet}, publisher = {FH Aachen}, address = {Aachen}, school = {Fachhochschule Aachen}, pages = {101 Seiten}, year = {2024}, abstract = {«Keno» zeigt ein Konzept f{\"u}r einen Online-Marktplatz im Fashion-Segment, mit Fokus auf individueller Beratung, digitaler Anprobe und visueller sowie informativer Pr{\"a}sentation der Marken. Marktpl{\"a}tze werden aufgrund von großer Auswahl und Vertrauensw{\"u}rdigkeit von Konsument:innen bevorzugt aufgesucht. Durch die immersive Darstellung an einem maßgetreuen Avatar und die Einbindung der Marke in das Einkaufserlebnis soll hier die Zahl der Retouren verringert und die Kund:innenzufriedenheit gesteigert werden. Mittels nutzerorientierter Strategien und der Gestaltung eines Designsystems bekam «Keno» seinen Look. Dabei fanden modernste Techniken wie k{\"u}nstliche Intelligenzen und Design Token Systeme Verwendung. Das Projekt zeigt letztendlich M{\"o}glichkeiten auf, wie ein Marktplatz durch Brand Experience, Onlineshopping-Wege verk{\"u}rzen und zu mehr Nachhaltigkeit im E-Commerce beitragen kann.}, language = {de} } @masterthesis{Frings2024, type = {Bachelor Thesis}, author = {Frings, Christina}, title = {Unerw{\"u}nscht : Anti-Gestaltung im {\"o}ffentlichen Raum}, publisher = {FH Aachen}, address = {Aachen}, school = {Fachhochschule Aachen}, pages = {55 Seiten}, year = {2024}, abstract = {»Unerw{\"u}nscht« widmet sich einer Art von architektonischer Gestaltung, die auf t{\"u}ckische Weise als »defensive Architektur« bezeichnet wird. In Form einer Zeitung bietet sie einen umfassenden Einblick in das Thema und gew{\"a}hrt einen vielseitigen Blick in eine Thematik, die im Interesse der Verantwortlichen lieber im Verborgenen geblieben w{\"a}re. Defensive Architektur bezeichnet strategische Baumaßnahmen in der Stadt- und Bauplanung, die darauf abzielen, unerw{\"u}nschte Personengruppen durch unpraktisches oder unbequemes Design von bestimmten Orten fernzuhalten. Diese Maßnahmen richten sich beispielsweise gegen obdachlose Menschen, Jugendliche oder Skateboarder*innen. Die {\"u}berwiegende Mehrheit der Bev{\"o}lkerung ist sich weder der Existenz von solchen architektonischen Maßnahmen noch ihrer Auswirkungen auf das Leben der Betroffenen bewusst. »Unerw{\"u}nscht« zielt darauf ab, diese L{\"u}cke in der {\"o}ffentlichen Wahrnehmung zu schließen.}, language = {de} } @masterthesis{Fuchs2024, type = {Bachelor Thesis}, author = {Fuchs, Simon}, title = {CSTHEMAG : ein Magazin f{\"u}r die Streetwear-Community von CSTHELABEL}, publisher = {FH Aachen}, address = {Aachen}, pages = {181 Seiten}, year = {2024}, abstract = {In einer Welt, die von st{\"a}ndiger Vernetzung und sozialen Medien gepr{\"a}gt ist, gibt es eine sp{\"u}rbare L{\"u}cke f{\"u}r Menschen, die sich f{\"u}r die »Streetwear-Culture« interessieren. Viele junge Menschen, die von Fashion, Streetwear und der damit einhergehenden Kultur fasziniert sind, stoßen in ihrem direkten Umfeld oft auf Schwierigkeiten, Gleichgesinnte zu finden. CSTHELABEL hat es sich zur Aufgabe gemacht, die lebendige Streetwear-Community zu st{\"a}rken und weiter zu f{\"o}rdern. CSTHEMAG ist ein Projekt, das in Kollaboration mit dem Gr{\"u}nder von CSTHELABEL entstanden ist. Es wurde eine Nullnummer f{\"u}r die erste Ausgabe des Magazins konzipiert, gestaltet und produziert. Diese beinhaltet Interviews mit Content-Creatorn aus der Community, jungen Modesch{\"o}pfer:innen sowie einen Einblick in vergangene Events und Pop-Ups. Das Magazin bietet Mitwirkenden und zuk{\"u}nftig Interessierten einen Raum in einem f{\"u}r das Label neuen Medium und schafft die M{\"o}glichkeit, ihre Stimmen zu st{\"a}rken. CSTHEMAG verpflichtet sich gegen{\"u}ber der lebendigen Community, eine eigene Plattform zu bieten, auf der ihre einzigartigen Talente, Geschichten und Inspirationen zum Ausdruck kommen.}, language = {de} } @masterthesis{Heinemann2024, type = {Bachelor Thesis}, author = {Heinemann, Katja}, title = {112 - Wenn Helfer Hilfe brauchen}, publisher = {FH Aachen}, address = {Aachen}, pages = {67 Seiten}, year = {2024}, abstract = {Der Rettungsdienst ist rund um die Uhr bei medizinischen Notf{\"a}llen im Einsatz. Wie aber ist dieser organisiert? Was belastet die Mitarbeiter*innen im Berufsalltag? Und wie kann man die Rettungskr{\"a}fte unterst{\"u}tzen? „112-WENN HELFER HILFE BRAUCHEN" bietet einen sachlichen Einblick in die Welt des Rettungsdienstes und der Ersten Hilfe. Mit kurz gefassten Fakten und Illustrationen richtet sich das Projekt vor allem an Jugendliche und junge Erwachsene. Ziel ist es, mehr Verst{\"a}ndnis und Wertsch{\"a}tzung in der Gesellschaft f{\"u}r diese Berufsgruppe zu schaffen. Zus{\"a}tzlich soll es die Leser*innen ermutigen, im Ernstfall angemessen zu handeln und „Leben zu retten". Denn jeder kann in eine Notsituation geraten und auf den Rettungsdienst und Erste Hilfe angewiesen sein. Je fr{\"u}her man sich mit der Thematik besch{\"a}ftigt, desto besser ist man im Ernstfall vorbereitet.}, language = {de} } @article{BertzSchoeningMolinnusetal.2024, author = {Bertz, Morten and Sch{\"o}ning, Michael Josef and Molinnus, Denise and Homma, Takayuki}, title = {Influence of temperature, light, and H₂O₂ concentration on microbial spore inactivation: in-situ Raman spectroscopy combined with optical trapping}, series = {Physica status solidi (a) applications and materials science}, journal = {Physica status solidi (a) applications and materials science}, number = {Early View}, publisher = {Wiley-VCH}, address = {Berlin}, issn = {1862-6319 (Online)}, doi = {10.1002/pssa.202300866}, pages = {8 Seiten}, year = {2024}, abstract = {To gain insight on chemical sterilization processes, the influence of temperature (up to 70 °C), intense green light, and hydrogen peroxide (H₂O₂) concentration (up to 30\% in aqueous solution) on microbial spore inactivation is evaluated by in-situ Raman spectroscopy with an optical trap. Bacillus atrophaeus is utilized as a model organism. Individual spores are isolated and their chemical makeup is monitored under dynamically changing conditions (temperature, light, and H₂O₂ concentration) to mimic industrially relevant process parameters for sterilization in the field of aseptic food processing. While isolated spores in water are highly stable, even at elevated temperatures of 70 °C, exposure to H₂O₂ leads to a loss of spore integrity characterized by the release of the key spore biomarker dipicolinic acid (DPA) in a concentration-dependent manner, which indicates damage to the inner membrane of the spore. Intensive light or heat, both of which accelerate the decomposition of H₂O₂ into reactive oxygen species (ROS), drastically shorten the spore lifetime, suggesting the formation of ROS as a rate-limiting step during sterilization. It is concluded that Raman spectroscopy can deliver mechanistic insight into the mode of action of H₂O₂-based sterilization and reveal the individual contributions of different sterilization methods acting in tandem.}, language = {en} } @article{PogorelovaRogachevAkimbekovetal.2024, author = {Pogorelova, Natalia and Rogachev, Evgeniy and Akimbekov, Nuraly S. and Digel, Ilya}, title = {Effect of dehydration method on the micro- and nanomorphological properties of bacterial cellulose produced by Medusomyces gisevii on different substrates}, series = {Journal of materials science}, volume = {2024}, journal = {Journal of materials science}, publisher = {Springer Science + Business Media}, address = {Dordrecht}, issn = {1573-4803 (Online)}, doi = {10.1007/s10853-024-09596-3}, pages = {13 Seiten}, year = {2024}, abstract = {Many important properties of bacterial cellulose (BC), such as moisture absorption capacity, elasticity and tensile strength, largely depend on its structure. This paper presents a study on the effect of the drying method on BC films produced by Medusomyces gisevii using two different procedures: room temperature drying (RT, (24 ± 2 °C, humidity 65 ± 1\%, dried until a constant weight was reached) and freeze-drying (FD, treated at - 75 °C for 48 h). BC was synthesized using one of two different carbon sources—either glucose or sucrose. Structural differences in the obtained BC films were evaluated using atomic force microscopy (AFM), scanning electron microscopy (SEM), and X-ray diffraction. Macroscopically, the RT samples appeared semi-transparent and smooth, whereas the FD group exhibited an opaque white color and sponge-like structure. SEM examination showed denser packing of fibrils in FD samples while RT-samples displayed smaller average fiber diameter, lower surface roughness and less porosity. AFM confirmed the SEM observations and showed that the FD material exhibited a more branched structure and a higher surface roughness. The samples cultivated in a glucose-containing nutrient medium, generally displayed a straight and ordered shape of fibrils compared to the sucrose-derived BC, characterized by a rougher and wavier structure. The BC films dried under different conditions showed distinctly different crystallinity degrees, whereas the carbon source in the culture medium was found to have a relatively small effect on the BC crystallinity.}, language = {en} } @masterthesis{Jansen2024, type = {Bachelor Thesis}, author = {Jansen, Marie}, title = {Budzi Budzi}, publisher = {FH Aachen}, address = {Aachen}, school = {Fachhochschule Aachen}, pages = {53 Seiten}, year = {2024}, abstract = {Mit {\"u}ber 1300 B{\"u}dchen in 86 Veedeln ist K{\"o}ln Deutschlands Kiosk-Hauptstadt. Sie sind ein pr{\"a}gendes Element von Nachbarschaften und geh{\"o}ren zum K{\"o}lner Stadtbild einfach dazu wie der Dom und der Rhein. Durch Anekdoten, Interviews, Beitr{\"a}ge zur Popkultur, alte Fotografien, Momentaufnahmen und vertraute Grafiken sowie einer festen Formsprache entsteht das erste B{\"u}dchenmagazin f{\"u}r K{\"o}ln. Das Periodikum erscheint alle drei Monate und liegt kostenfrei in den B{\"u}dchen aus. Es ist eine Publikation die beweist, dass B{\"u}dchen mehr als g{\"a}ngige Verkaufsstellen sind, sondern Knotenpunkte unserer Gesellschaft.}, language = {de} } @masterthesis{Jung2024, type = {Bachelor Thesis}, author = {Jung, Maximilian}, title = {Out of the Box : Cardistry Dokumentarfilm}, publisher = {FH Aachen}, address = {Aachen}, pages = {75 Seiten}, year = {2024}, abstract = {"Out of the Box" ist ein Dokumentarfilm und bietet einen Einblick in die Welt des "Cardistry". Der Schwerpunkt liegt auf dieser Nischenkunst und -kultur der visuell ansprechenden Kartenmanipulation. Der Film beleuchtet den Beginn, die Entwicklung und die lebendige Gemeinschaft hinter dieser einzigartigen Kunstform. Dar{\"u}ber hinaus werden Abgrenzungen, Urspr{\"u}nge und {\"A}hnlichkeiten zur Kartenmagie erforscht.}, language = {de} } @article{Finkenberger2022, author = {Finkenberger, Isabel Maria}, title = {Transformatives Forschen, Lehren und Handeln im Rheinischen Braunkohlerevier}, series = {Forum Wohnen und Stadtentwicklung}, volume = {2022}, journal = {Forum Wohnen und Stadtentwicklung}, number = {2}, publisher = {vhw}, address = {Berlin}, issn = {1439-7242}, pages = {69 -- 72}, year = {2022}, abstract = {Die Institution Hochschule hat das Potenzial, {\"u}ber transformatives Forschen und Lehren und den entsprechenden Wissenstransfer in den lokalen Kontext strategisch-verl{\"a}ssliche Partnerin der Großen Transformation zur Nachhaltigkeit zu werden und bei der Ausbildung von Pionierinnen und Pionieren des Wandels mitzuwirken. Der Lehr- und Forschungsschwerpunkt „Zukunftsf{\"a}hige Transformation" am Fachbereich Architektur der FH Aachen widmet sich seit 2020 dem Tagebauumfeld Hambach im Rheinischen Revier, um dort angewandt und in Kooperation neue Narrative, innovative Prozesse, ortsbezogene Konzepte und strategische Projekte zu entwickeln und umzusetzen.}, language = {de} } @article{FinkenbergerSchlaich2014, author = {Finkenberger, Isabel Maria and Schlaich, Christoph}, title = {Mehr als Wohnen. Vom Zusammenleben in integrierten Nachbarschaften}, series = {APuZ - Aus Politik und Zeitgeschichte}, volume = {2014}, journal = {APuZ - Aus Politik und Zeitgeschichte}, number = {20-21}, publisher = {Bundeszentrale f{\"u}r politische Bildung - bpb}, address = {Bonn}, issn = {2194-3621}, pages = {46 -- 52}, year = {2014}, abstract = {Neue D{\"o}rfer braucht das Land! D{\"o}rfer in der Stadt und D{\"o}rfer auf dem Land (…). Die Planung und Gestaltung nachhaltiger Raumsysteme, die durch ein neues Verst{\"a}ndnis des gemeinschaftlichen Besitzes (und dessen Nutzung) ressourcenfressende Individualisierungstendenzen unserer Gesellschaft {\"u}berwinden, aber zugleich gr{\"o}ßtm{\"o}glichen Freiraum f{\"u}r eine individuelle Pers{\"o}nlichkeitsentfaltung zur Verf{\"u}gung stellen." Dieses Zitat der Hamburger Initiative "Wir sind Dorf" beschreibt eine aktuelle Diskussion in unserer Gesellschaft, die sowohl in der Forschung und forschungsgeleiteten Initiativen, in Politik und Planung als auch in der B{\"u}rger-schaft stattfindet. Sie wird nicht nur auf wissenschaftlichen Veranstaltungen gef{\"u}hrt, sondern auch in konkreten Projekten f{\"u}r integrative Lebenswelten, die Fragestellungen von Ern{\"a}hrung und Energieversorgung, von Arbeit und {\"O}konomie, aber auch eines neuen r{\"a}umlichen und sozialen Miteinanders einbeziehen. Anders als bei den weit verbreiteten Baugruppen geht es nicht ausschließlich um die Schaffung von Wohnraum. Die Nachbarschaftsidee verbindet das Bed{\"u}rfnis nach gemeinschaftlichem Wohnen und Wirtschaften mit einer neuen Werteorientierung, die auf pers{\"o}nlicher Verantwortungs{\"u}bernahme beruht.}, language = {de} } @article{Finkenberger2014, author = {Finkenberger, Isabel Maria}, title = {Vox populi. (Transformations-)potenziale nachkriegsmoderner Freiraumressourcen}, series = {Stadt+Gr{\"u}n}, volume = {2014}, journal = {Stadt+Gr{\"u}n}, number = {1}, publisher = {Patzer}, address = {Berlin}, issn = {0948-9770}, pages = {31 -- 35}, year = {2014}, abstract = {Heute wie damals werden die großz{\"u}gigen und offenen Siedlungsstrukturen der ersten Nachkriegsjahrzehnte mit ihrem hohen Anteil an "Gr{\"u}n" vielfach gesch{\"a}tzt und als solche nicht grundlegend hinterfragt. "Gr{\"u}n" verheißt im Allgemeinen Licht, Luft und Sonne, Freizeit und Erholung und gilt als etwas W{\"u}nschenswertes im st{\"a}dtischen Kontext. Unbeachtet bleibt, dass dem Begriff "Gr{\"u}n" zun{\"a}chst keine Eigenschaften oder Qualit{\"a}ten zugewiesen sind - er sagt noch lange nichts {\"u}ber dessen r{\"a}umliche Qualit{\"a}t, dessen Nutzbarkeit, Erreichbarkeit und Zug{\"a}nglichkeit aus. Abstandsgr{\"u}n und Straßenbegleitgr{\"u}n ist eben auch "Gr{\"u}n". Neben einer quantitativen Argumentation, welche {\"o}kologischen Aspekte wie Biotopvernetzung, Stadt- und Mikroklima ber{\"u}cksichtigt, sollten wir verst{\"a}rkt qualitativ denken und damit die Grundlage f{\"u}r einen erweiterten und wesentlich differenzierteren Diskurs {\"u}ber urbane Freir{\"a}ume ebnen.}, language = {de} } @incollection{Finkenberger2013, author = {Finkenberger, Isabel Maria}, title = {Vox populi. (Transformations-)potenziale nachkriegsmoderner Freiraumressourcen}, series = {Gr{\"u}n modern - G{\"a}rten und Parks der 1950er bis 1970er Jahre}, booktitle = {Gr{\"u}n modern - G{\"a}rten und Parks der 1950er bis 1970er Jahre}, editor = {Bredenbeck, Martin}, publisher = {BHU}, address = {Bonn}, isbn = {9783925374357}, pages = {31 -- 38}, year = {2013}, language = {de} } @article{HoffstadtNikolauszKrafftetal.2024, author = {Hoffstadt, Kevin and Nikolausz, Marcell and Krafft, Simone and Bonatelli, Maria and Kumar, Vivekanantha and Harms, Hauke and Kuperjans, Isabel}, title = {Optimization of the ex situ biomethanation of hydrogen and carbon dioxide in a novel meandering plug flow reactor: start-up phase and flexible operation}, series = {Bioengineering}, volume = {11}, journal = {Bioengineering}, number = {2}, publisher = {MDPI}, address = {Basel}, issn = {2306-5354}, doi = {10.3390/bioengineering11020165}, pages = {18 Seiten}, year = {2024}, language = {en} } @masterthesis{Latz2021, type = {Bachelor Thesis}, author = {Latz, Annika}, title = {Konzeptentwicklung einer spielerischen Lernanwendung f{\"u}r Studierende}, school = {Fachhochschule Aachen}, pages = {XIV, 136 Seiten}, year = {2021}, abstract = {Ziel der Arbeit war es eine spielerische Lernanwendung f{\"u}r Studierende der FH-Aachen zu entwickeln, um das individuelle Lernen zu f{\"o}rdern. Dabei lag der Fokus auf der Konzeptentwicklung eines Serious Games f{\"u}r die Fachhochschule Aachen. Abgeleitet von Motivationstheorien, Game Design Frameworks und Eigenschaften von digitalen spielerischen Konzepten wurde ein Vorgehensmodell zur Konzeptentwicklung eines Serious Games erstellt. Wichtige Punkte f{\"u}r die Anwendung waren eine intensive Austauschm{\"o}glichkeiten f{\"u}r Studierende und das Integrieren dieser in die Lehrveranstaltungen der FH-Aachen. In der abschließenden Evaluation wurde positives Feedback der Studierenden eingeholt und damit das Ziel der Arbeit erreicht. Zus{\"a}tzlich wurde f{\"u}r das erarbeitete Konzept die Wirtschaftlichkeit {\"u}berpr{\"u}ft. Daf{\"u}r wurde w{\"a}hrend der Bearbeitungszeit mit einem aufgestellten Team ein Business Plan f{\"u}r das F{\"o}rderprogramm Start-Up transfer.NRW entwickelt.}, language = {de} } @incollection{KraftKohlMeinecke2024, author = {Kraft, Bodo and Kohl, Philipp and Meinecke, Matthias}, title = {Analyse und Nachverfolgung von Projektzielen durch Einsatz von Natural Language Processing}, series = {KI in der Projektwirtschaft : was ver{\"a}ndert sich durch KI im Projektmanagement?}, booktitle = {KI in der Projektwirtschaft : was ver{\"a}ndert sich durch KI im Projektmanagement?}, editor = {Bernert, Christian and Scheurer, Steffen and Wehnes, Harald}, publisher = {UVK Verlag}, isbn = {978-3-3811-1132-9 (Online)}, doi = {10.24053/9783381111329}, pages = {157 -- 167}, year = {2024}, language = {de} } @incollection{Finkenberger2024, author = {Finkenberger, Isabel Maria}, title = {Transformatives Handeln als disziplin{\"u}berschreitende, kollektive Aktion. Stadtentwicklung trifft k{\"u}nstlerische und kollaborative Handlungspraxen}, series = {Por{\"o}s-Werden : geteilte R{\"a}ume, urbane Dramaturgien, performatives Kuratieren}, booktitle = {Por{\"o}s-Werden : geteilte R{\"a}ume, urbane Dramaturgien, performatives Kuratieren}, editor = {B{\"u}scher, Barbara and Krasny, Elke and Ortmann, Lucie}, publisher = {Turia + Kant}, address = {Wien}, isbn = {978-3-98514-543-0}, pages = {144 -- 158}, year = {2024}, language = {de} } @incollection{Krause2024, author = {Krause, Thomas}, title = {Schalung und Ger{\"u}ste}, series = {Zahlentafeln f{\"u}r den Baubetrieb}, booktitle = {Zahlentafeln f{\"u}r den Baubetrieb}, editor = {Krause, Thomas and Ulke, Bernd and Ferger, Martin}, publisher = {Springer Vieweg}, address = {Wiesbaden}, isbn = {978-3-658-41329-3 (Print)}, doi = {10.1007/978-3-658-41330-9_10}, pages = {659 -- 705}, year = {2024}, abstract = {Systemschalungen und Systemger{\"u}ste haben den Baustellenbetrieb in vielen Bereichen sehr vereinfacht. Dennoch sind Kenntnisse in diesen Feldern f{\"u}r eine erfolgreiche und effektive Bauleitung unverzichtbar. In diesem Kapitel werden Hinweise und Empfehlungen f{\"u}r die Bemessung und Einsatz von Schalungen, Trag- und Arbeitsger{\"u}sten f{\"u}r den Baustellenbetrieb gegeben.}, language = {de} } @incollection{Ulke2024, author = {Ulke, Bernd}, title = {Kalkulation}, series = {Zahlentafeln f{\"u}r den Baubetrieb}, booktitle = {Zahlentafeln f{\"u}r den Baubetrieb}, editor = {Krause, Thomas and Ulke, Bernd and Ferger, Martin}, publisher = {Springer Vieweg}, address = {Wiesbaden}, isbn = {978-3-658-41329-3 (Print)}, doi = {10.1007/978-3-658-41330-9_12}, pages = {801 -- 909}, year = {2024}, abstract = {Das Kapitel behandelt die Kosten- und Preisermittlung, die Kostenvorgabe und Kostenkontrolle. Der Angebotspreis wird aufgeschl{\"u}sselt in die Einzelkosten der Teilleistungen, die Baustellengemeinkosten, die Allgemeinen Gesch{\"a}ftskosten und einen Zuschlag f{\"u}r Wagnis und Gewinn. Auf der Basis der Angebotskalkulation werden die Vorgaben f{\"u}r die Kostenkontrolle entwickelt.}, language = {de} } @incollection{MelznerFerger2024, author = {Melzner, J{\"u}rgen and Ferger, Martin}, title = {Building Information Modeling}, series = {Zahlentafeln f{\"u}r den Baubetrieb}, booktitle = {Zahlentafeln f{\"u}r den Baubetrieb}, editor = {Krause, Thomas and Ulke, Bernd and Ferger, Martin}, publisher = {Springer Vieweg}, address = {Wiesbaden}, isbn = {978-3-658-41329-3 (Print)}, doi = {10.1007/978-3-658-41330-9_15}, pages = {1051 -- 1073}, year = {2024}, abstract = {Durch die Einf{\"u}hrung von Building Information Modeling (BIM) sowohl projektspezifisch als auch in ganze Unternehmungen hat die Baubranche einen weitreichenden Ver{\"a}nderungsprozess angestoßen. Building Information Modeling kann als eine Methode angesehen werden, um die Informationsasymmetrien zwischen den Projektbeteiligten so gering wie m{\"o}glich zu halten.}, language = {de} } @book{LaumannWolf2024, author = {Laumann, J{\"o}rg and Wolf, Christian}, title = {Stahlbau 1 : Bemessung von Stahlbauten nach Eurocode mit zahlreichen Beispielen}, edition = {26., {\"u}berarbeitete und aktualisierte Auflage}, publisher = {Springer Vieweg}, address = {Wiesbaden}, isbn = {978-3-658-41323-1 (Print)}, doi = {10.1007/978-3-658-41324-8}, pages = {XVI, 661 Seiten}, year = {2024}, language = {de} } @masterthesis{Lambertus2024, type = {Bachelor Thesis}, author = {Lambertus, Jan-Michael}, title = {CardboardCastle}, publisher = {FH Aachen}, address = {Aachen}, school = {Fachhochschule Aachen}, pages = {60 Seiten}, year = {2024}, abstract = {„CardboardCastle" ist ein 3D-Animationsfilm. Der Film zeigt die lebendig gewordene Welt zweier K{\"o}nigreiche aus Pappe, die in einem Streit um einen magischen Zauberstab verwickelt sind. Das Projekt beweist, dass es m{\"o}glich ist, mit der Software „Blender" einen vollwertigen und hochwertigen 3D-Animationsfilm zu erstellen. Dabei wurden alle Assets bis auf Texturen selbst hergestellt. Die virtuelle Pappe spielt hierbei eine fundamentale Rolle, f{\"u}r diese wurde ein vollkommen neuer Workflow entwickelt, welcher es erm{\"o}glicht, realistische Pappe zu visualisieren. „CardboardCastle" setzt auf eine cinematische Inszenierung von Licht und vereint technisches Wissen mit unterhaltenden Inhalten. Dabei zeigt er die kindliche Vorstellungskraft und l{\"a}dt die Zuschauer ein, sich an ihre eigenen kindlichen Fantasien zu erinnern.}, language = {de} } @masterthesis{Liedtke2024, type = {Bachelor Thesis}, author = {Liedtke, Janna}, title = {Lehrmaterial f{\"u}r den Tiroler Skilehrerverband: Konzeption f{\"u}r eine crossmediale Neugestaltung}, publisher = {FH Aachen}, address = {Aachen}, school = {Fachhochschule Aachen}, pages = {68 Seiten}, year = {2024}, abstract = {Der Tiroler Skilehrerverband bereitet angehende Skilehrer:innen auf die verschiedenen Schneesportlehrer-Pr{\"u}fungen vor. Skilehrer:innen spielen eine entscheidende Rolle im Erfolg des Wintertourismus, was ihre gesellschaftliche und wirtschaftliche Relevanz unterstreicht. Die zeitgem{\"a}ße Neugestaltung des Lehrmaterials soll eine effektive Vermittlung von Lerninhalten erm{\"o}glichen. Durch die Kombination von Informationsdesign, Corporate Design und Editorial Design wird die Verst{\"a}ndlichkeit und Attraktivit{\"a}t des Materials gesteigert. Die Integration einer Lernapp erm{\"o}glicht eine interaktive und multimediale Lernerfahrung sowie mehr Flexibilit{\"a}t f{\"u}r die Lernenden. Die crossmediale Neugestaltung wirkt den Problemen veralteter Darstellungsformen entgegen. Es wird deutlich, dass gut gestaltetes Lehrmaterial bei gleichbleibenden Inhalten zu einer besseren Lernerfahrung f{\"u}hrt.}, language = {de} } @misc{OPUS4-11128, title = {Dimensionen Nr. 30 / 2023: Magazin der FH Aachen University of Applied Sciences - Der Mensch im Mittelpunkt}, address = {Aachen}, organization = {Fachhochschule Aachen}, pages = {62 Seiten}, year = {2023}, abstract = {06| Warum es gemeinsam besser geht 10| Interview 14| Wer ist hier der Boss? 18| Schnittstelle zwischen Mensch und Technik 22| Zweite Heimat J{\"u}lich 28| Zwischen Angst und Hoffnung 32| Eine Sternstunde f{\"u}r die FH Aachen 36| Gegen alle Widerst{\"a}nde 38| Ein Ort, der bleibt 42| Der Aufbl{\"u}hende 46| Der Computer sitzt am Steuer 52| Da geht das Herz auf 54| Hoch hinaus 58| Beratungsangebote 60| Das alte Sch{\"a}tzchen}, language = {de} } @article{KarschuckPoghossianSeretal.2024, author = {Karschuck, Tobias and Poghossian, Arshak and Ser, Joey and Tsokolakyan, Astghik and Achtsnicht, Stefan and Wagner, Patrick and Sch{\"o}ning, Michael Josef}, title = {Capacitive model of enzyme-modified field-effect biosensors: Impact of enzyme coverage}, series = {Sensors and Actuators B: Chemical}, volume = {408}, journal = {Sensors and Actuators B: Chemical}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0925-4005 (Print)}, doi = {10.1016/j.snb.2024.135530}, pages = {12 Seiten}, year = {2024}, abstract = {Electrolyte-insulator-semiconductor capacitors (EISCAP) belong to field-effect sensors having an attractive transducer architecture for constructing various biochemical sensors. In this study, a capacitive model of enzyme-modified EISCAPs has been developed and the impact of the surface coverage of immobilized enzymes on its capacitance-voltage and constant-capacitance characteristics was studied theoretically and experimentally. The used multicell arrangement enables a multiplexed electrochemical characterization of up to sixteen EISCAPs. Different enzyme coverages have been achieved by means of parallel electrical connection of bare and enzyme-covered single EISCAPs in diverse combinations. As predicted by the model, with increasing the enzyme coverage, both the shift of capacitance-voltage curves and the amplitude of the constant-capacitance signal increase, resulting in an enhancement of analyte sensitivity of the EISCAP biosensor. In addition, the capability of the multicell arrangement with multi-enzyme covered EISCAPs for sequentially detecting multianalytes (penicillin and urea) utilizing the enzymes penicillinase and urease has been experimentally demonstrated and discussed.}, language = {en} } @article{BornheimGriegerBlanecketal.2024, author = {Bornheim, Tobias and Grieger, Niklas and Blaneck, Patrick Gustav and Bialonski, Stephan}, title = {Speaker Attribution in German Parliamentary Debates with QLoRA-adapted Large Language Models}, series = {Journal for language technology and computational linguistics : JLCL}, volume = {37}, journal = {Journal for language technology and computational linguistics : JLCL}, number = {1}, publisher = {Gesellschaft f{\"u}r Sprachtechnologie und Computerlinguistik}, address = {Regensburg}, issn = {2190-6858}, doi = {10.21248/jlcl.37.2024.244}, pages = {13 Seiten}, year = {2024}, abstract = {The growing body of political texts opens up new opportunities for rich insights into political dynamics and ideologies but also increases the workload for manual analysis. Automated speaker attribution, which detects who said what to whom in a speech event and is closely related to semantic role labeling, is an important processing step for computational text analysis. We study the potential of the large language model family Llama 2 to automate speaker attribution in German parliamentary debates from 2017-2021. We fine-tune Llama 2 with QLoRA, an efficient training strategy, and observe our approach to achieve competitive performance in the GermEval 2023 Shared Task On Speaker Attribution in German News Articles and Parliamentary Debates. Our results shed light on the capabilities of large language models in automating speaker attribution, revealing a promising avenue for computational analysis of political discourse and the development of semantic role labeling systems.}, language = {en} } @inproceedings{FunkeBeckmannStefanetal.2023, author = {Funke, Harald and Beckmann, Nils and Stefan, Lukas and Keinz, Jan}, title = {Hydrogen combustor integration study for a medium range aircraft engine using the dry-low NOx "Micromix" combustion principle}, series = {Proceedings of the ASME Turbo Expo 2023: Turbomachinery Technical Conference and Exposition. Volume 1: Aircraft Engine.}, booktitle = {Proceedings of the ASME Turbo Expo 2023: Turbomachinery Technical Conference and Exposition. Volume 1: Aircraft Engine.}, publisher = {ASME}, address = {New York}, isbn = {978-0-7918-8693-9}, doi = {10.1115/GT2023-102370}, pages = {12 Seiten}, year = {2023}, abstract = {The feasibility study presents results of a hydrogen combustor integration for a Medium-Range aircraft engine using the Dry-Low-NOₓ Micromix combustion principle. Based on a simplified Airbus A320-type flight mission, a thermodynamic performance model of a kerosene and a hydrogen-powered V2530-A5 engine is used to derive the thermodynamic combustor boundary conditions. A new combustor design using the Dry-Low NOx Micromix principle is investigated by slice model CFD simulations of a single Micromix injector for design and off-design operation of the engine. Combustion characteristics show typical Micromix flame shapes and good combustion efficiencies for all flight mission operating points. Nitric oxide emissions are significant below ICAO CAEP/8 limits. For comparison of the Emission Index (EI) for NOₓ emissions between kerosene and hydrogen operation, an energy (kerosene) equivalent Emission Index is used. A full 15° sector model CFD simulation of the combustion chamber with multiple Micromix injectors including inflow homogenization and dilution and cooling air flows investigates the combustor integration effects, resulting NOₓ emission and radial temperature distributions at the combustor outlet. The results show that the integration of a Micromix hydrogen combustor in actual aircraft engines is feasible and offers, besides CO₂ free combustion, a significant reduction of NOₓ emissions compared to kerosene operation.}, language = {en} } @inproceedings{GehlerOberBloebaumDachwald2009, author = {Gehler, M. and Ober-Bl{\"o}baum, S. and Dachwald, Bernd}, title = {Application of discrete mechanics and optimal control to spacecraft in non-keplerian motion around small solar system bodies}, series = {Procceedings of the 60th International Astronautical Congress}, booktitle = {Procceedings of the 60th International Astronautical Congress}, publisher = {Elsevier}, address = {Amsterdam}, isbn = {978-161567908-9}, pages = {1360 -- 1371}, year = {2009}, abstract = {Prolonged operations close to small solar system bodies require a sophisticated control logic to minimize propellant mass and maximize operational efficiency. A control logic based on Discrete Mechanics and Optimal Control (DMOC) is proposed and applied to both conventionally propelled and solar sail spacecraft operating at an arbitrarily shaped asteroid in the class of Itokawa. As an example, stand-off inertial hovering is considered, recently identified as a challenging part of the Marco Polo mission. The approach is easily extended to stand-off orbits. We show that DMOC is applicable to spacecraft control at small objects, in particular with regard to the fact that the changes in gravity are exploited by the algorithm to optimally control the spacecraft position. Furthermore, we provide some remarks on promising developments.}, language = {en} } @inproceedings{DachwaldWurm2009, author = {Dachwald, Bernd and Wurm, P.}, title = {Design concept and modeling of an advanced solar photon thruster}, series = {Advances in the Astronautical Sciences}, booktitle = {Advances in the Astronautical Sciences}, publisher = {American Astronautical Society}, address = {San Diego, Calif.}, isbn = {978-087703554-1}, issn = {00653438}, pages = {723 -- 740}, year = {2009}, abstract = {The so-called "compound solar sail", also known as "Solar Photon Thruster" (SPT), holds the potential of providing significant performance advantages over the flat solar sail. Previous SPT design concepts, however, do not consider shadowing effects and multiple reflections of highly concentrated solar radiation that would inevitably destroy the gossamer sail film. In this paper, we propose a novel advanced SPT (ASPT) design concept that does not suffer from these oversimplifications. We present the equations that describe the thrust force acting on such a sail system and compare its performance with respect to the conventional flat solar sail.}, language = {en} } @incollection{Dachwald2017, author = {Dachwald, Bernd}, title = {Light propulsion systems for spacecraft}, series = {Optical nano and micro actuator technology}, booktitle = {Optical nano and micro actuator technology}, editor = {Knopf, George K. and Otani, Yukitoshi}, publisher = {CRC Press}, address = {Boca Raton}, isbn = {9781315217628 (eBook)}, pages = {577 -- 598}, year = {2017}, language = {en} } @inproceedings{DachwaldWurm2009, author = {Dachwald, Bernd and Wurm, P.}, title = {Mission analysis for an advanced solar photon thruster}, series = {60th International Astronautical Congress 2009, IAC 2009}, volume = {8}, booktitle = {60th International Astronautical Congress 2009, IAC 2009}, publisher = {Elsevier}, address = {Amsterdam}, isbn = {978-161567908-9}, pages = {6838 -- 6851}, year = {2009}, abstract = {The so-called "compound solar sail", also known as "Solar Photon Thruster" (SPT), is a solar sail design concept, for which the two basic functions of the solar sail, namely light collection and thrust direction, are uncoupled. In this paper, we introduce a novel SPT concept, termed the Advanced Solar Photon Thruster (ASPT). This model does not suffer from the simplified assumptions that have been made for the analysis of compound solar sails in previous studies. We present the equations that describe the force, which acts on the ASPT. After a detailed design analysis, the performance of the ASPT with respect to the conventional flat solar sail (FSS) is investigated for three interplanetary mission scenarios: An Earth-Venus rendezvous, where the solar sail has to spiral towards the Sun, an Earth-Mars rendezvous, where the solar sail has to spiral away from the Sun, and an Earth-NEA rendezvous (to near-Earth asteroid 1996FG3), where a large orbital eccentricity change is required. The investigated solar sails have realistic near-term characteristic accelerations between 0.1 and 0.2mm/s2. Our results show that a SPT is not superior to the flat solar sail unless very idealistic assumptions are made.}, language = {en} } @article{BaumgartnerFidlerWethetal.2008, author = {Baumgartner, Werner and Fidler, Florian and Weth, Agnes and Habbecke, Martin and Jakob, Peter and Butenweg, Christoph and B{\"o}hme, Wolfgang}, title = {Investigating the locomotion of the sandfish in desert sand using NMR-Imaging}, series = {PLOS ONE}, volume = {3}, journal = {PLOS ONE}, number = {10}, publisher = {Plos}, address = {San Francisco, California, US}, issn = {1932-6203}, doi = {10.1371/journal.pone.0003309}, pages = {e3309}, year = {2008}, abstract = {The sandfish (Scincus scincus) is a lizard having the remarkable ability to move through desert sand for significant distances. It is well adapted to living in loose sand by virtue of a combination of morphological and behavioural specializations. We investigated the bodyform of the sandfish using 3D-laserscanning and explored its locomotion in loose desert sand using fast nuclear magnetic resonance (NMR) imaging. The sandfish exhibits an in-plane meandering motion with a frequency of about 3 Hz and an amplitude of about half its body length accompanied by swimming-like (or trotting) movements of its limbs. No torsion of the body was observed, a movement required for a digging-behaviour. Simple calculations based on the Janssen model for granular material related to our findings on bodyform and locomotor behaviour render a local decompaction of the sand surrounding the moving sandfish very likely. Thus the sand locally behaves as a viscous fluid and not as a solid material. In this fluidised sand the sandfish is able to "swim" using its limbs.}, language = {en} } @inproceedings{GoemmelButenwegKob2007, author = {G{\"o}mmel, A. and Butenweg, Christoph and Kob, M.}, title = {A fluid-structure interaction model of vocal fold oscillation}, series = {5th International Workshop on Models and Analysis of Vocal Emissions for Biomedical Applications, MAVEBA 2007}, booktitle = {5th International Workshop on Models and Analysis of Vocal Emissions for Biomedical Applications, MAVEBA 2007}, isbn = {978-888453674-7}, pages = {127 -- 128}, year = {2007}, abstract = {Since fluid-structure interaction within the finite-element method is state of the art in many engineering fields, this method is used in voice analysis. A quasi two-dimensional model of the vocal folds including the ventricular folds is presented. First results of self-sustained vocal fold oscillation are presented and possibilities as well as limitations are discussed.}, language = {en} } @article{SchoenrockMuckeltHastermannetal.2024, author = {Schoenrock, Britt and Muckelt, Paul E. and Hastermann, Maria and Albracht, Kirsten and MacGregor, Robert and Martin, David and Gunga, Hans-Christian and Salanova, Michele and Stokes, Maria J. and Warner, Martin B. and Blottner, Dieter}, title = {Muscle stiffness indicating mission crew health in space}, series = {Scientific Reports}, volume = {14}, journal = {Scientific Reports}, number = {Article number: 4196}, publisher = {Springer Nature}, address = {London}, issn = {2045-2322}, doi = {10.1038/s41598-024-54759-6}, pages = {13 Seiten}, year = {2024}, abstract = {Muscle function is compromised by gravitational unloading in space affecting overall musculoskeletal health. Astronauts perform daily exercise programmes to mitigate these effects but knowing which muscles to target would optimise effectiveness. Accurate inflight assessment to inform exercise programmes is critical due to lack of technologies suitable for spaceflight. Changes in mechanical properties indicate muscle health status and can be measured rapidly and non-invasively using novel technology. A hand-held MyotonPRO device enabled monitoring of muscle health for the first time in spaceflight (> 180 days). Greater/maintained stiffness indicated countermeasures were effective. Tissue stiffness was preserved in the majority of muscles (neck, shoulder, back, thigh) but Tibialis Anterior (foot lever muscle) stiffness decreased inflight vs. preflight (p < 0.0001; mean difference 149 N/m) in all 12 crewmembers. The calf muscles showed opposing effects, Gastrocnemius increasing in stiffness Soleus decreasing. Selective stiffness decrements indicate lack of preservation despite daily inflight countermeasures. This calls for more targeted exercises for lower leg muscles with vital roles as ankle joint stabilizers and in gait. Muscle stiffness is a digital biomarker for risk monitoring during future planetary explorations (Moon, Mars), for healthcare management in challenging environments or clinical disorders in people on Earth, to enable effective tailored exercise programmes.}, language = {en} } @article{KahmannRauschPluemeretal.2022, author = {Kahmann, Stephanie L. and Rausch, Valentin and Pl{\"u}mer, Jonathan and M{\"u}ller, Lars P. and Pieper, Martin and Wegmann, Kilian}, title = {The automized fracture edge detection and generation of three-dimensional fracture probability heat maps}, series = {Medical Engineering \& Physics}, volume = {2022}, journal = {Medical Engineering \& Physics}, number = {110}, publisher = {Elsevier}, address = {Amsterdam}, issn = {1350-4533}, pages = {7 Seiten}, year = {2022}, abstract = {With proven impact of statistical fracture analysis on fracture classifications, it is desirable to minimize the manual work and to maximize repeatability of this approach. We address this with an algorithm that reduces the manual effort to segmentation, fragment identification and reduction. The fracture edge detection and heat map generation are performed automatically. With the same input, the algorithm always delivers the same output. The tool transforms one intact template consecutively onto each fractured specimen by linear least square optimization, detects the fragment edges in the template and then superimposes them to generate a fracture probability heat map. We hypothesized that the algorithm runs faster than the manual evaluation and with low (< 5 mm) deviation. We tested the hypothesis in 10 fractured proximal humeri and found that it performs with good accuracy (2.5 mm ± 2.4 mm averaged Euclidean distance) and speed (23 times faster). When applied to a distal humerus, a tibia plateau, and a scaphoid fracture, the run times were low (1-2 min), and the detected edges correct by visual judgement. In the geometrically complex acetabulum, at a run time of 78 min some outliers were considered acceptable. An automatically generated fracture probability heat map based on 50 proximal humerus fractures matches the areas of high risk of fracture reported in medical literature. Such automation of the fracture analysis method is advantageous and could be extended to reduce the manual effort even further.}, language = {en} } @inproceedings{GrundAltherr2023, author = {Grund, Raphael M. and Altherr, Lena}, title = {Development of an open source energy disaggregation tool for the home automation platform Home Assistant}, series = {Tagungsband AALE 2023 : mit Automatisierung gegen den Klimawandel}, booktitle = {Tagungsband AALE 2023 : mit Automatisierung gegen den Klimawandel}, editor = {Reiff-Stephan, J{\"o}rg and J{\"a}kel, Jens and Schwarz, Andr{\´e}}, publisher = {le-tex publishing services GmbH}, address = {Leipzig}, isbn = {978-3-910103-01-6}, doi = {10.33968/2023.02}, pages = {11 -- 20}, year = {2023}, abstract = {In order to reduce energy consumption of homes, it is important to make transparent which devices consume how much energy. However, power consumption is often only monitored aggregated at the house energy meter. Disaggregating this power consumption into the contributions of individual devices can be achieved using Machine Learning. Our work aims at making state of the art disaggregation algorithms accessibe for users of the open source home automation platform Home Assistant.}, language = {en} } @misc{BragardHueningKowalewski2023, author = {Bragard, Michael and H{\"u}ning, Felix and Kowalewski, Paul}, title = {Vorrichtung zur Relativlagenbestimmung [Offenlegungschrift]}, year = {2023}, abstract = {Die Erfindung betrifft eine Vorrichtung zur Bestimmung einer Relativlage zwischen einem feststehenden Teil und einem zu demselben in eine Bewegungsrichtung bewegbaren beweglichen Teil, wobei der feststehende Teil mit einem Wiegandsensor versehen ist, wobei der Wiegandsensor zwischen zwei gegenpolig zueinander ausgebildeten Permanentmagneten angeordnet ist und dass der bewegliche Teil eine Mehrzahl von beabstandet zueinander angeordneten Magnetisierungsstegen aus einem magnetisch leitenden Material aufweist, die in der Bewegungsrichtung zumindest eine gleich große Erstreckung aufweisen wie der Permanentmagnet, dass ein Abstand zwischen benachbarten Magnetisierungsstegen derart gew{\"a}hlt ist, dass in einer ersten Relativlage ein erster Permanentmagnet von einem der Magnetisierungsstege {\"u}berdeckt ist und ein zweiter Permanentmagnet nicht von einem der Magnetisierungsstege {\"u}berdeckt ist.}, language = {de} } @inproceedings{WittigRuettersBragard2024, author = {Wittig, M. and R{\"u}tters, Ren{\´e} and Bragard, Michael}, title = {Application of RL in control systems using the example of a rotatory inverted pendulum}, series = {Tagungsband AALE 2024 : Fit f{\"u}r die Zukunft: praktische L{\"o}sungen f{\"u}r die industrielle Automation}, booktitle = {Tagungsband AALE 2024 : Fit f{\"u}r die Zukunft: praktische L{\"o}sungen f{\"u}r die industrielle Automation}, editor = {Reiff-Stephan, J{\"o}rg and J{\"a}kel, Jens and Schwarz, Andr{\´e}}, publisher = {le-tex publishing services GmbH}, address = {Leipzig}, isbn = {978-3-910103-02-3}, doi = {10.33968/2024.53}, pages = {241 -- 248}, year = {2024}, abstract = {In this paper, the use of reinforcement learning (RL) in control systems is investigated using a rotatory inverted pendulum as an example. The control behavior of an RL controller is compared to that of traditional LQR and MPC controllers. This is done by evaluating their behavior under optimal conditions, their disturbance behavior, their robustness and their development process. All the investigated controllers are developed using MATLAB and the Simulink simulation environment and later deployed to a real pendulum model powered by a Raspberry Pi. The RL algorithm used is Proximal Policy Optimization (PPO). The LQR controller exhibits an easy development process, an average to good control behavior and average to good robustness. A linear MPC controller could show excellent results under optimal operating conditions. However, when subjected to disturbances or deviations from the equilibrium point, it showed poor performance and sometimes instable behavior. Employing a nonlinear MPC Controller in real time was not possible due to the high computational effort involved. The RL controller exhibits by far the most versatile and robust control behavior. When operated in the simulation environment, it achieved a high control accuracy. When employed in the real system, however, it only shows average accuracy and a significantly greater performance loss compared to the simulation than the traditional controllers. With MATLAB, it is not yet possible to directly post-train the RL controller on the Raspberry Pi, which is an obstacle to the practical application of RL in a prototyping or teaching setting. Nevertheless, RL in general proves to be a flexible and powerful control method, which is well suited for complex or nonlinear systems where traditional controllers struggle.}, language = {en} } @article{EngelmannSimsekShalabyetal.2024, author = {Engelmann, Ulrich M. and Simsek, Beril and Shalaby, Ahmed and Krause, Hans-Joachim}, title = {Key contributors to signal generation in frequency mixing magnetic detection (FMMD): an in silico study}, series = {Sensors}, volume = {24}, journal = {Sensors}, number = {6}, publisher = {MDPI}, address = {Basel}, issn = {1424-8220}, doi = {10.3390/s24061945}, pages = {Artikel 1945}, year = {2024}, abstract = {Frequency mixing magnetic detection (FMMD) is a sensitive and selective technique to detect magnetic nanoparticles (MNPs) serving as probes for binding biological targets. Its principle relies on the nonlinear magnetic relaxation dynamics of a particle ensemble interacting with a dual frequency external magnetic field. In order to increase its sensitivity, lower its limit of detection and overall improve its applicability in biosensing, matching combinations of external field parameters and internal particle properties are being sought to advance FMMD. In this study, we systematically probe the aforementioned interaction with coupled N{\´e}el-Brownian dynamic relaxation simulations to examine how key MNP properties as well as applied field parameters affect the frequency mixing signal generation. It is found that the core size of MNPs dominates their nonlinear magnetic response, with the strongest contributions from the largest particles. The drive field amplitude dominates the shape of the field-dependent response, whereas effective anisotropy and hydrodynamic size of the particles only weakly influence the signal generation in FMMD. For tailoring the MNP properties and parameters of the setup towards optimal FMMD signal generation, our findings suggest choosing large particles of core sizes dc > 25 nm nm with narrow size distributions (σ < 0.1) to minimize the required drive field amplitude. This allows potential improvements of FMMD as a stand-alone application, as well as advances in magnetic particle imaging, hyperthermia and magnetic immunoassays.}, language = {en} } @article{ZhenLiangStaatetal.2024, author = {Zhen, Manghao and Liang, Yunpei and Staat, Manfred and Li, Quanqui and Li, Jianbo}, title = {Discontinuous fracture behaviors and constitutive model of sandstone specimens containing non-parallel prefabricated fissures under uniaxial compression}, series = {Theoretical and Applied Fracture Mechanics}, volume = {131}, journal = {Theoretical and Applied Fracture Mechanics}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0167-8442}, doi = {10.1016/j.tafmec.2024.104373}, pages = {Artikel 104373}, year = {2024}, abstract = {The deformation and damage laws of non-homogeneous irregular structural planes in rocks are the basis for studying the stability of rock engineering. To investigate the damage characteristics of rock containing non-parallel fissures, uniaxial compression tests and numerical simulations were conducted on sandstone specimens containing three non-parallel fissures inclined at 0°, 45° and 90° in this study. The characteristics of crack initiation and crack evolution of fissures with different inclinations were analyzed. A constitutive model for the discontinuous fractures of fissured sandstone was proposed. The results show that the fracture behaviors of fissured sandstone specimens are discontinuous. The stress-strain curves are non-smooth and can be divided into nonlinear crack closure stage, linear elastic stage, plastic stage and brittle failure stage, of which the plastic stage contains discontinuous stress drops. During the uniaxial compression test, the middle or ends of 0° fissures were the first to crack compared to 45° and 90° fissures. The end with small distance between 0° and 45° fissures cracked first, and the end with large distance cracked later. After the final failure, 0° fissures in all specimens were fractured, while 45° and 90° fissures were not necessarily fractured. Numerical simulation results show that the concentration of compressive stress at the tips of 0°, 45° and 90° fissures, as well as the concentration of tensile stress on both sides, decreased with the increase of the inclination angle. A constitutive model for the discontinuous fractures of fissured sandstone specimens was derived by combining the logistic model and damage mechanic theory. This model can well describe the discontinuous drops of stress and agrees well with the whole processes of the stress-strain curves of the fissured sandstone specimens.}, language = {en} } @inproceedings{ZahraPhaniSrujanCaminosetal.2022, author = {Zahra, Mahdi and Phani Srujan, Merige and Caminos, Ricardo Alexander Chico and Schmitz, Pascal and Herrmann, Ulf and Teixeira Boura, Cristiano Jos{\´e} and Schmitz, Mark and Gielen, Hans and Gedle, Yibekal and Dersch, J{\"u}rgen}, title = {Modeling the thermal behavior of solar salt in electrical resistance heaters for the application in PV-CSP hybrid power plants}, series = {SOLARPACES 2020}, booktitle = {SOLARPACES 2020}, number = {2445 / 1}, publisher = {AIP conference proceedings / American Institute of Physics}, address = {Melville, NY}, isbn = {978-0-7354-4195-8}, issn = {1551-7616 (online)}, doi = {10.1063/5.0086268}, pages = {9 Seiten}, year = {2022}, abstract = {Concentrated Solar Power (CSP) systems are able to store energy cost-effectively in their integrated thermal energy storage (TES). By intelligently combining Photovoltaics (PV) systems with CSP, a further cost reduction of solar power plants is expected, as well as an increase in dispatchability and flexibility of power generation. PV-powered Resistance Heaters (RH) can be deployed to raise the temperature of the molten salt hot storage from 385 °C up to 565 °C in a Parabolic Trough Collector (PTC) plant. To avoid freezing and decomposition of molten salt, the temperature distribution in the electrical resistance heater is investigated in the present study. For this purpose, a RH has been modeled and CFD simulations have been performed. The simulation results show that the hottest regions occur on the electric rod surface behind the last baffle. A technical optimization was performed by adjusting three parameters: Shell-baffle clearance, electric rod-baffle clearance and number of baffles. After the technical optimization was carried out, the temperature difference between the maximum temperature and the average outlet temperature of the salt is within the acceptable limits, thus critical salt decomposition has been avoided. Additionally, the CFD simulations results were analyzed and compared with results obtained with a one-dimensional model in Modelica.}, language = {en} } @inproceedings{CaminosSchmitzAttietal.2022, author = {Caminos, Ricardo Alexander Chico and Schmitz, Pascal and Atti, Vikrama and Mahdi, Zahra and Teixeira Boura, Cristiano Jos{\´e} and Sattler, Johannes Christoph and Herrmann, Ulf and Hilger, Patrick and Dieckmann, Simon}, title = {Development of a micro heliostat and optical qualification assessment with a 3D laser scanning method}, series = {SOLARPACES 2020}, booktitle = {SOLARPACES 2020}, number = {2445 / 1}, publisher = {AIP conference proceedings / American Institute of Physics}, address = {Melville, NY}, isbn = {978-0-7354-4195-8}, issn = {1551-7616 (online)}, doi = {10.1063/5.0086262}, pages = {8 Seiten}, year = {2022}, abstract = {The Solar-Institut J{\"u}lich (SIJ) and the companies Hilger GmbH and Heliokon GmbH from Germany have developed a small-scale cost-effective heliostat, called "micro heliostat". Micro heliostats can be deployed in small-scale concentrated solar power (CSP) plants to concentrate the sun's radiation for electricity generation, space or domestic water heating or industrial process heat. In contrast to conventional heliostats, the special feature of a micro heliostat is that it consists of dozens of parallel-moving, interconnected, rotatable mirror facets. The mirror facets array is fixed inside a box-shaped module and is protected from weathering and wind forces by a transparent glass cover. The choice of the building materials for the box, tracking mechanism and mirrors is largely dependent on the selected production process and the intended application of the micro heliostat. Special attention was paid to the material of the tracking mechanism as this has a direct influence on the accuracy of the micro heliostat. The choice of materials for the mirror support structure and the tracking mechanism is made in favor of plastic molded parts. A qualification assessment method has been developed by the SIJ in which a 3D laser scanner is used in combination with a coordinate measuring machine (CMM). For the validation of this assessment method, a single mirror facet was scanned and the slope deviation was computed.}, language = {en} } @inproceedings{NiederwestbergSchneiderTeixeiraBouraetal.2022, author = {Niederwestberg, Stefan and Schneider, Falko and Teixeira Boura, Cristiano Jos{\´e} and Herrmann, Ulf}, title = {Introduction to a direct irradiated transparent tube particle receiver}, series = {SOLARPACES 2020}, booktitle = {SOLARPACES 2020}, number = {2445 / 1}, publisher = {AIP conference proceedings / American Institute of Physics}, address = {Melville, NY}, isbn = {978-0-7354-4195-8}, issn = {1551-7616 (online)}, doi = {10.1063/5.0086735}, pages = {9 Seiten}, year = {2022}, abstract = {New materials often lead to innovations and advantages in technical applications. This also applies to the particle receiver proposed in this work that deploys high-temperature and scratch resistant transparent ceramics. With this receiver design, particles are heated through direct-contact concentrated solar irradiance while flowing downwards through tubular transparent ceramics from top to bottom. In this paper, the developed particle receiver as well as advantages and disadvantages are described. Investigations on the particle heat-up characteristics from solar irradiance were carried out with DEM simulations which indicate that particle temperatures can reach up to 1200 K. Additionally, a simulation model was set up for investigating the dynamic behavior. A test receiver at laboratory scale has been designed and is currently being built. In upcoming tests, the receiver test rig will be used to validate the simulation results. The design and the measurement equipment is described in this work.}, language = {en} } @inproceedings{NeumannAdamBackesetal.2021, author = {Neumann, Hannah and Adam, Mario and Backes, Klaus and B{\"o}rner, Martin and Clees, Tanja and Doetsch, Christian and Glaeser, Susanne and Herrmann, Ulf and May, Johanna and Rosenthal, Florian and Sauer, Dirk Uwe and Stadler, Ingo}, title = {Development of open educational resources for renewable energy and the energy transition process}, series = {ISES SWC 2021}, booktitle = {ISES SWC 2021}, publisher = {International Solar Energy Society}, address = {Freiburg}, doi = {10.18086/swc.2021.47.03}, pages = {6 Seiten}, year = {2021}, abstract = {The dissemination of knowledge about renewable energies is understood as a social task with the highest topicality. The transfer of teaching content on renewable energies into digital open educational resources offers the opportunity to significantly accelerate the implementation of the energy transition. Thus, in the here presented project six German universities create open educational resources for the energy transition. These materials are available to the public on the internet under a free license. So far there has been no publicly accessible, editable media that cover entire learning units about renewable energies extensively and in high technical quality. Thus, in this project, the content that remains up-to-date for a longer period is appropriately prepared in terms of media didactics. The materials enable lecturers to provide students with in-depth training about technologies for the energy transition. In a particular way, the created material is also suitable for making the general public knowledgeable about the energy transition with scientifically based material.}, language = {en} } @misc{Huening2024, author = {H{\"u}ning, Felix}, title = {Positionssensorvorrichtung}, year = {2024}, abstract = {Die Erfindung betrifft eine Positionssensorvorrichtung zur Bestimmung einer Absolutposition eines beweglichen ersten Teils relativ zu einem ortsfesten zweiten Teil mit einem mit dem beweglichen ersten Teil gekoppelter Codek{\"o}rper, der dazu eingerichtet ist, eine Codespur mit einer Mehrzahl von in Spurrichtung aufeinanderfolgenden Codeelementen zu enthalten zur Bildung eines Codewortes, mit einer magnetischen Detektionseinrichtung zur Detektion der Codespur, wobei die Detektionseinrichtung zum einen an dem Codek{\"o}rper befestigte und entlang der Spurrichtung in einem solchen Abstand gegenpolig zueinander angeordnete Permanentmagneten aufweist, dass der Abstand mit einer vorgegebenen L{\"a}nge der jeweiligen Codeelemente {\"u}bereinstimmt, und zum anderen eine Anzahl von ortsfest und quer zu dem Codek{\"o}rper versetzt angeordnete Wiegandsensoren aufweist, wobei der Abstand des Wiegandsensors zu einer Erstreckungsebene der Permanentmagneten derart gew{\"a}hlt ist, dass bei {\"U}berdeckung des Wiegandsensors durch den Permanentmagneten ein Wiegandpuls in dem Wiegandsensor induziert wird.}, language = {de} } @inproceedings{SattlerSchneiderAngeleetal.2022, author = {Sattler, Johannes Christoph and Schneider, Iesse Peer and Angele, Florian and Atti, Vikrama and Teixeira Boura, Cristiano Jos{\´e} and Herrmann, Ulf}, title = {Development of heliostat field calibration methods: Theory and experimental test results}, series = {SolarPACES 2022 conference proceedings}, booktitle = {SolarPACES 2022 conference proceedings}, number = {1}, publisher = {TIB Open Publishing}, address = {Hannover}, issn = {2751-9899 (online)}, doi = {10.52825/solarpaces.v1i.678}, pages = {9 Seiten}, year = {2022}, abstract = {In this work, three patent pending calibration methods for heliostat fields of central receiver systems (CRS) developed by the Solar-Institut J{\"u}lich (SIJ) of the FH Aachen University of Applied Sciences are presented. The calibration methods can either operate in a combined mode or in stand-alone mode. The first calibration method, method A, foresees that a camera matrix is placed into the receiver plane where it is subjected to concentrated solar irradiance during a measurement process. The second calibration method, method B, uses an unmanned aerial vehicle (UAV) such as a quadrocopter to automatically fly into the reflected solar irradiance cross-section of one or more heliostats (two variants of method B were tested). The third calibration method, method C, foresees a stereo central camera or multiple stereo cameras installed e.g. on the solar tower whereby the orientations of the heliostats are calculated from the location detection of spherical red markers attached to the heliostats. The most accurate method is method A which has a mean accuracy of 0.17 mrad. The mean accuracy of method B variant 1 is 1.36 mrad and of variant 2 is 1.73 mrad. Method C has a mean accuracy of 15.07 mrad. For method B there is great potential regarding improving the measurement accuracy. For method C the collected data was not sufficient for determining whether or not there is potential for improving the accuracy.}, language = {en} } @inproceedings{SattlerAttiAlexopoulosetal.2022, author = {Sattler, Johannes Christoph and Atti, Vikrama and Alexopoulos, Spiros and Teixeira Boura, Cristiano Jos{\´e} and Herrmann, Ulf and Dutta, Siddharth and Kioutsioukis, Ioannis}, title = {DNI forecast tool for the smart operation of a parabolic trough collector system with concrete thermal energy storage: Theory, results and outlook}, series = {SolarPACES 2022 conference proceedings}, booktitle = {SolarPACES 2022 conference proceedings}, number = {1}, publisher = {TIB Open Publishing}, address = {Hannover}, issn = {2751-9899 (online)}, doi = {10.52825/solarpaces.v1i.731}, pages = {9 Seiten}, year = {2022}, abstract = {This work presents a basic forecast tool for predicting direct normal irradiance (DNI) in hourly resolution, which the Solar-Institut J{\"u}lich (SIJ) is developing within a research project. The DNI forecast data shall be used for a parabolic trough collector (PTC) system with a concrete thermal energy storage (C-TES) located at the company KEAN Soft Drinks Ltd in Limassol, Cyprus. On a daily basis, 24-hour DNI prediction data in hourly resolution shall be automatically produced using free or very low-cost weather forecast data as input. The purpose of the DNI forecast tool is to automatically transfer the DNI forecast data on a daily basis to a main control unit (MCU). The MCU automatically makes a smart decision on the operation mode of the PTC system such as steam production mode and/or C-TES charging mode. The DNI forecast tool was evaluated using historical data of measured DNI from an on-site weather station, which was compared to the DNI forecast data. The DNI forecast tool was tested using data from 56 days between January and March 2022, which included days with a strong variation in DNI due to cloud passages. For the evaluation of the DNI forecast reliability, three categories were created and the forecast data was sorted accordingly. The result was that the DNI forecast tool has a reliability of 71.4 \% based on the tested days. The result fulfils SIJ's aim to achieve a reliability of around 70 \%, but SIJ aims to still improve the DNI forecast quality.}, language = {en} } @inproceedings{SchwagerAngeleNourietal.2022, author = {Schwager, Christian and Angele, Florian and Nouri, Bijan and Schwarzb{\"o}zl, Peter and Teixeira Boura, Cristiano Jos{\´e} and Herrmann, Ulf}, title = {Impact of DNI forecast quality on performance prediction for a commercial scale solar tower: Application of nowcasting DNI maps to dynamic solar tower simulation}, series = {SolarPACES 2022 conference proceedings}, booktitle = {SolarPACES 2022 conference proceedings}, number = {1}, publisher = {TIB Open Publishing}, address = {Hannover}, issn = {2751-9899 (online)}, doi = {10.52825/solarpaces.v1i.675}, pages = {9 Seiten}, year = {2022}, abstract = {Concerning current efforts to improve operational efficiency and to lower overall costs of concentrating solar power (CSP) plants with prediction-based algorithms, this study investigates the quality and uncertainty of nowcasting data regarding the implications for process predictions. DNI (direct normal irradiation) maps from an all-sky imager-based nowcasting system are applied to a dynamic prediction model coupled with ray tracing. The results underline the need for high-resolution DNI maps in order to predict net yield and receiver outlet temperature realistically. Furthermore, based on a statistical uncertainty analysis, a correlation is developed, which allows for predicting the uncertainty of the net power prediction based on the corresponding DNI forecast uncertainty. However, the study reveals significant prediction errors and the demand for further improvement in the accuracy at which local shadings are forecasted.}, language = {en} } @inproceedings{SchulteSchwagerFrantzetal.2022, author = {Schulte, Jonas and Schwager, Christian and Frantz, Cathy and Schloms, Felix and Teixeira Boura, Cristiano Jos{\´e} and Herrmann, Ulf}, title = {Control concept for a molten salt receiver in star design: Development, optimization and testing with cloud passage scenarios}, series = {SolarPACES 2022 conference proceedings}, booktitle = {SolarPACES 2022 conference proceedings}, number = {1}, publisher = {TIB Open Publishing}, address = {Hannover}, issn = {2751-9899 (online)}, doi = {10.52825/solarpaces.v1i.693}, pages = {9 Seiten}, year = {2022}, abstract = {A promising approach to reduce the system costs of molten salt solar receivers is to enable the irradiation of the absorber tubes on both sides. The star design is an innovative receiver design, pursuing this approach. The unconventional design leads to new challenges in controlling the system. This paper presents a control concept for a molten salt receiver system in star design. The control parameters are optimized in a defined test cycle by minimizing a cost function. The control concept is tested in realistic cloud passage scenarios based on real weather data. During these tests, the control system showed no sign of unstable behavior, but to perform sufficiently in every scenario further research and development like integrating Model Predictive Controls (MPCs) need to be done. The presented concept is a starting point to do so.}, language = {en} } @unpublished{GriegerMehrkanoonBialonski2024, author = {Grieger, Niklas and Mehrkanoon, Siamak and Bialonski, Stephan}, title = {Preprint: Data-efficient sleep staging with synthetic time series pretraining}, series = {arXiv}, journal = {arXiv}, pages = {10 Seiten}, year = {2024}, abstract = {Analyzing electroencephalographic (EEG) time series can be challenging, especially with deep neural networks, due to the large variability among human subjects and often small datasets. To address these challenges, various strategies, such as self-supervised learning, have been suggested, but they typically rely on extensive empirical datasets. Inspired by recent advances in computer vision, we propose a pretraining task termed "frequency pretraining" to pretrain a neural network for sleep staging by predicting the frequency content of randomly generated synthetic time series. Our experiments demonstrate that our method surpasses fully supervised learning in scenarios with limited data and few subjects, and matches its performance in regimes with many subjects. Furthermore, our results underline the relevance of frequency information for sleep stage scoring, while also demonstrating that deep neural networks utilize information beyond frequencies to enhance sleep staging performance, which is consistent with previous research. We anticipate that our approach will be advantageous across a broad spectrum of applications where EEG data is limited or derived from a small number of subjects, including the domain of brain-computer interfaces.}, language = {en} } @inproceedings{LahrsKrisamHerrmann2023, author = {Lahrs, Lennart and Krisam, Pierre and Herrmann, Ulf}, title = {Envisioning a collaborative energy system planning platform for the energy transition at the district level}, series = {ECOS 2023. The 36th International Conference on Efficiency, Cost, Optimization, Simulation and Environmental Impact of Energy Systems}, booktitle = {ECOS 2023. The 36th International Conference on Efficiency, Cost, Optimization, Simulation and Environmental Impact of Energy Systems}, publisher = {Procedings of ECOS 2023}, doi = {10.52202/069564-0284}, pages = {3163 -- 3170}, year = {2023}, abstract = {Residential and commercial buildings account for more than one-third of global energy-related greenhouse gas emissions. Integrated multi-energy systems at the district level are a promising way to reduce greenhouse gas emissions by exploiting economies of scale and synergies between energy sources. Planning district energy systems comes with many challenges in an ever-changing environment. Computational modelling established itself as the state-of-the-art method for district energy system planning. Unfortunately, it is still cumbersome to combine standalone models to generate insights that surpass their original purpose. Ideally, planning processes could be solved by using modular tools that easily incorporate the variety of competing and complementing computational models. Our contribution is a vision for a collaborative development and application platform for multi-energy system planning tools at the district level. We present challenges of district energy system planning identified in the literature and evaluate whether this platform can help to overcome these challenges. Further, we propose a toolkit that represents the core technical elements of the platform. Lastly, we discuss community management and its relevance for the success of projects with collaboration and knowledge sharing at their core.}, language = {en} } @inproceedings{SchulteSchwagerNoureldinetal.2023, author = {Schulte, Jonas and Schwager, Christian and Noureldin, Kareem and May, Martin and Teixeira Boura, Cristiano Jos{\´e} and Herrmann, Ulf}, title = {Gradient controlled startup procedure of a molten-salt power-to-heat energy storage plant based on dynamic process simulation}, series = {SolarPACES: Solar Power \& Chemical Energy Systems}, booktitle = {SolarPACES: Solar Power \& Chemical Energy Systems}, number = {2815 / 1}, publisher = {AIP conference proceedings / American Institute of Physics}, address = {Melville, NY}, isbn = {978-0-7354-4623-6}, issn = {1551-7616 (online)}, doi = {10.1063/5.0148741}, pages = {9 Seiten}, year = {2023}, abstract = {The integration of high temperature thermal energy storages into existing conventional power plants can help to reduce the CO2 emissions of those plants and lead to lower capital expenditures for building energy storage systems, due to the use of synergy effects [1]. One possibility to implement that, is a molten salt storage system with a powerful power-to-heat unit. This paper presents two possible control concepts for the startup of the charging system of such a facility. The procedures are implemented in a detailed dynamic process model. The performance and safety regarding the film temperatures at heat transmitting surfaces are investigated in the process simulations. To improve the accuracy in predicting the film temperatures, CFD simulations of the electrical heater are carried out and the results are merged with the dynamic model. The results show that both investigated control concepts are safe regarding the temperature limits. The gradient controlled startup performed better than the temperature-controlled startup. Nevertheless, there are several uncertainties that need to be investigated further.}, language = {en} } @inproceedings{SchwagerAngeleSchwarzboezletal.2023, author = {Schwager, Christian and Angele, Florian and Schwarzb{\"o}zl, Peter and Teixeira Boura, Cristiano Jos{\´e} and Herrmann, Ulf}, title = {Model predictive assistance for operational decision making in molten salt receiver systems}, series = {SolarPACES: Solar Power \& Chemical Energy Systems}, booktitle = {SolarPACES: Solar Power \& Chemical Energy Systems}, number = {2815 / 1}, publisher = {AIP conference proceedings / American Institute of Physics}, address = {Melville, NY}, isbn = {978-0-7354-4623-6}, issn = {1551-7616 (online)}, doi = {10.1063/5.0151514}, pages = {8 Seiten}, year = {2023}, abstract = {Despite the challenges of pioneering molten salt towers (MST), it remains the leading technology in central receiver power plants today, thanks to cost effective storage integration and high cost reduction potential. The limited controllability in volatile solar conditions can cause significant losses, which are difficult to estimate without comprehensive modeling [1]. This paper presents a Methodology to generate predictions of the dynamic behavior of the receiver system as part of an operating assistance system (OAS). Based on this, it delivers proposals if and when to drain and refill the receiver during a cloudy period in order maximize the net yield and quantifies the amount of net electricity gained by this. After prior analysis with a detailed dynamic two-phase model of the entire receiver system, two different reduced modeling approaches where developed and implemented in the OAS. A tailored decision algorithm utilizes both models to deliver the desired predictions efficiently and with appropriate accuracy.}, language = {en} } @article{SchwagerFleschSchwarzboezletal.2022, author = {Schwager, Christian and Flesch, Robert and Schwarzb{\"o}zl, Peter and Herrmann, Ulf and Teixeira Boura, Cristiano Jos{\´e}}, title = {Advanced two phase flow model for transient molten salt receiver system simulation}, series = {Solar Energy}, volume = {232}, journal = {Solar Energy}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0038-092X (print)}, doi = {10.1016/j.solener.2021.12.065}, pages = {362 -- 375}, year = {2022}, abstract = {In order to realistically predict and optimize the actual performance of a concentrating solar power (CSP) plant sophisticated simulation models and methods are required. This paper presents a detailed dynamic simulation model for a Molten Salt Solar Tower (MST) system, which is capable of simulating transient operation including detailed startup and shutdown procedures including drainage and refill. For appropriate representation of the transient behavior of the receiver as well as replication of local bulk and surface temperatures a discretized receiver model based on a novel homogeneous two-phase (2P) flow modelling approach is implemented in Modelica Dymola®. This allows for reasonable representation of the very different hydraulic and thermal properties of molten salt versus air as well as the transition between both. This dynamic 2P receiver model is embedded in a comprehensive one-dimensional model of a commercial scale MST system and coupled with a transient receiver flux density distribution from raytracing based heliostat field simulation. This enables for detailed process prediction with reasonable computational effort, while providing data such as local salt film and wall temperatures, realistic control behavior as well as net performance of the overall system. Besides a model description, this paper presents some results of a validation as well as the simulation of a complete startup procedure. Finally, a study on numerical simulation performance and grid dependencies is presented and discussed.}, language = {en} } @inproceedings{GedleSchmitzGielenetal.2022, author = {Gedle, Yibekal and Schmitz, Mark and Gielen, Hans and Schmitz, Pascal and Herrmann, Ulf and Teixeira Boura, Cristiano Jos{\´e} and Mahdi, Zahra and Caminos, Ricardo Alexander Chico and Dersch, J{\"u}rgen}, title = {Analysis of an integrated CSP-PV hybrid power plant}, series = {SOLARPACES 2020}, booktitle = {SOLARPACES 2020}, number = {2445 / 1}, publisher = {AIP conference proceedings / American Institute of Physics}, address = {Melville, NY}, isbn = {978-0-7354-4195-8}, issn = {1551-7616 (online)}, doi = {10.1063/5.0086236}, pages = {9 Seiten}, year = {2022}, abstract = {In the past, CSP and PV have been seen as competing technologies. Despite massive reductions in the electricity generation costs of CSP plants, PV power generation is - at least during sunshine hours - significantly cheaper. If electricity is required not only during the daytime, but around the clock, CSP with its inherent thermal energy storage gets an advantage in terms of LEC. There are a few examples of projects in which CSP plants and PV plants have been co-located, meaning that they feed into the same grid connection point and ideally optimize their operation strategy to yield an overall benefit. In the past eight years, TSK Flagsol has developed a plant concept, which merges both solar technologies into one highly Integrated CSP-PV-Hybrid (ICPH) power plant. Here, unlike in simply co-located concepts, as analyzed e.g. in [1] - [4], excess PV power that would have to be dumped is used in electric molten salt heaters to increase the storage temperature, improving storage and conversion efficiency. The authors demonstrate the electricity cost sensitivity to subsystem sizing for various market scenarios, and compare the resulting optimized ICPH plants with co-located hybrid plants. Independent of the three feed-in tariffs that have been assumed, the ICPH plant shows an electricity cost advantage of almost 20\% while maintaining a high degree of flexibility in power dispatch as it is characteristic for CSP power plants. As all components of such an innovative concept are well proven, the system is ready for commercial market implementation. A first project is already contracted and in early engineering execution.}, language = {en} } @inproceedings{MahdiDerschSchmitzetal.2022, author = {Mahdi, Zahra and Dersch, J{\"u}rgen and Schmitz, Pascal and Dieckmann, Simon and Caminos, Ricardo Alexander Chico and Teixeira Boura, Cristiano Jos{\´e} and Herrmann, Ulf and Schwager, Christian and Schmitz, Mark and Gielen, Hans and Gedle, Yibekal and B{\"u}scher, Rauno}, title = {Technical assessment of Brayton cycle heat pumps for the integration in hybrid PV-CSP power plants}, series = {SOLARPACES 2020}, booktitle = {SOLARPACES 2020}, number = {2445 / 1}, publisher = {AIP conference proceedings / American Institute of Physics}, address = {Melville, NY}, isbn = {978-0-7354-4195-8}, issn = {1551-7616 (online)}, doi = {10.1063/5.0086269}, pages = {11 Seiten}, year = {2022}, abstract = {The hybridization of Concentrated Solar Power (CSP) and Photovoltaics (PV) systems is a promising approach to reduce costs of solar power plants, while increasing dispatchability and flexibility of power generation. High temperature heat pumps (HT HP) can be utilized to boost the salt temperature in the thermal energy storage (TES) of a Parabolic Trough Collector (PTC) system from 385 °C up to 565 °C. A PV field can supply the power for the HT HP, thus effectively storing the PV power as thermal energy. Besides cost-efficiently storing energy from the PV field, the power block efficiency of the overall system is improved due to the higher steam parameters. This paper presents a technical assessment of Brayton cycle heat pumps to be integrated in hybrid PV-CSP power plants. As a first step, a theoretical analysis was carried out to find the most suitable working fluid. The analysis included the fluids Air, Argon (Ar), Nitrogen (N2) and Carbon dioxide (CO2). N2 has been chosen as the optimal working fluid for the system. After the selection of the ideal working medium, different concepts for the arrangement of a HT HP in a PV-CSP hybrid power plant were developed and simulated in EBSILON®Professional. The concepts were evaluated technically by comparing the number of components required, pressure losses and coefficient of performance (COP).}, language = {en} } @book{ElsaesserKlebinggatKuhnetal.2024, author = {Elsaesser, Evelyn and Klebinggat, Michael and Kuhn, Wilfried and Michielsens, Constant and Pauels, Willibert and Popkes, Enno E. and Schneider, Elke and Laack, Walter van and Warven, Rinus van}, title = {Schnittstelle Tod - Ist die Menschheit zu retten ohne Vertrauen auf ein Danach}, editor = {Laack, Walter van}, publisher = {van Laack Buchverlag}, address = {Aachen}, isbn = {978-3-936624-58-8}, pages = {156 Seiten}, year = {2024}, language = {de} } @masterthesis{Kordes2024, type = {Bachelor Thesis}, author = {Kordes, Franka}, title = {Invisible Cities}, publisher = {FH Aachen}, address = {Aachen}, pages = {173 Seiten}, year = {2024}, abstract = {Diese Arbeit pr{\"a}sentiert eine Neuinterpretation des Romans "Invisible Cities" von Italo Calvino in einem handgefertigten, k{\"u}nstlerischen Buchobjekt. Seit der Erstver{\"o}ffentlichung des italienischen Literaturklassikers orientieren sich jegliche Neuauflagen an der Originalfassung. Die klassisch gestaltete Urversion wird der komplexen und eindrucksvollen Geschichte nicht mehr gerecht. Die Erz{\"a}hlung findet auf mehreren Ebenen statt, die durch verschiedene Papiersorten repr{\"a}sentiert werden. Die Lesenden wissen somit immer, wo sie sich auf ihrer Reise durch die traumhaften und surrealen St{\"a}dte befinden. Das Buch enth{\"a}lt mehrere Illustrationen auf Transparentpapierb{\"o}gen, welche die Stadtbeschreibungen begleiten. Der besondere Fokus der Arbeit lag in den Illustrationen und der technischen und handwerklichen Umsetzung der Bindung.}, language = {de} } @book{KrauseUlkeFerger2024, author = {Krause, Thomas and Ulke, Bernd and Ferger, Martin}, title = {Zahlentafeln f{\"u}r den Baubetrieb}, editor = {Krause, Thomas and Ulke, Bernd and Ferger, Martin}, edition = {10. Auflage}, publisher = {Springer Vieweg}, address = {Wiesbaden}, isbn = {978-3-658-41329-3 (Print)}, doi = {10.1007/978-3-658-41330-9}, pages = {XII, 1087 Seiten}, year = {2024}, language = {de} } @incollection{RickerUlke2024, author = {Ricker, Marcus and Ulke, Bernd}, title = {Baustoffe}, series = {Zahlentafeln f{\"u}r den Baubetrieb}, booktitle = {Zahlentafeln f{\"u}r den Baubetrieb}, editor = {Krause, Thomas and Ulke, Bernd and Ferger, Martin}, publisher = {Springer Vieweg}, address = {Wiesbaden}, isbn = {978-3-658-41329-3 (Print)}, doi = {10.1007/978-3-658-41330-9_2}, pages = {61 -- 148}, year = {2024}, abstract = {In diesem Kapitel werden die Eigenschaften der Baustoffe Bitumen, Beton und Mauerwerk insbesondere unter dem Aspekt der Anwendung im Baustellenbetrieb dargestellt.}, language = {de} } @incollection{Ulke2024, author = {Ulke, Bernd}, title = {Privates Baurecht und Nachtragsmanagement}, series = {Zahlentafeln f{\"u}r den Baubetrieb}, booktitle = {Zahlentafeln f{\"u}r den Baubetrieb}, editor = {Krause, Thomas and Ulke, Bernd and Ferger, Martin}, publisher = {Springer Vieweg}, address = {Wiesbaden}, isbn = {978-3-658-41329-3 (Print)}, doi = {10.1007/978-3-658-41330-9_3}, pages = {149 -- 216}, year = {2024}, abstract = {Kein Bauvorhaben sollte realisiert werden, ohne dass es auf einer vertraglichen Grundlage zwischen Auftraggeber und Auftragnehmer fußt. Diese vertragliche Grundlage zu kennen ist essenziell, um dementsprechend handeln zu k{\"o}nnen. Denn nur wer seine eigenen Rechte und auch Pflichten kennt, kann sich auf diese berufen.}, language = {de} } @incollection{Ulke2024, author = {Ulke, Bernd}, title = {Bauwirtschaft}, series = {Zahlentafeln f{\"u}r den Baubetrieb}, booktitle = {Zahlentafeln f{\"u}r den Baubetrieb}, editor = {Krause, Thomas and Ulke, Bernd and Ferger, Martin}, publisher = {Springer Vieweg}, address = {Wiesbaden}, isbn = {978-3-658-41329-3 (Print)}, doi = {10.1007/978-3-658-41330-9_4}, pages = {17 -- 261}, year = {2024}, abstract = {Die Leistungen der Bauwirtschaft und deren wirtschaftliche Bedeutung in Deutschland werden anhand einer Vielzahl statistischer Daten verdeutlicht. Die im Vergleich zu anderen Wirtschaftsbereichen auftretenden branchenspezifischen Besonderheiten der Bauwirtschaft werden anhand von verschiedenen Kriterien herausgearbeitet. Das Zusammenspiel der einzelnen Akteure des Sektors und die dabei sich ergebenden bzw. zu beachtenden Rechts- und Vertragsgrundlagen werden dargestellt. Aufgrund der meist erheblichen H{\"o}he des eingesetzten Kapitals werden auch notwendige Formen der Risikoabsicherungen und der in der Branche {\"u}blichen und teilweise vorgeschriebenen Versicherungsm{\"o}glichkeiten angesprochen.}, language = {de} } @incollection{Ulke2024, author = {Ulke, Bernd}, title = {{\"O}ffentliches Baurecht, Ausschreibung und Vergabe}, series = {Zahlentafeln f{\"u}r den Baubetrieb}, booktitle = {Zahlentafeln f{\"u}r den Baubetrieb}, editor = {Krause, Thomas and Ulke, Bernd and Ferger, Martin}, publisher = {Springer Vieweg}, address = {Wiesbaden}, isbn = {978-3-658-41329-3 (Print)}, doi = {10.1007/978-3-658-41330-9_5}, pages = {263 -- 297}, year = {2024}, abstract = {Durch das {\"o}ffentliche Baurecht werden die Zul{\"a}ssigkeit, die Grenzen, die Ordnung und die F{\"o}rderung der baulichen Nutzung des Bodens geregelt. Die Ausschreibung und die Vergabe sind von essenzieller Bedeutung f{\"u}r ein Bauvorhaben und werden deshalb in der HOAI mit zwei Leistungsphasen abgebildet: n{\"a}mlich mit der Leistungsphase 6 Vorbereitung der Vergabe sowie der Leistungsphase 7 Mitwirkung bei der Vergabe. Im Zuge der Ausschreibung und der Vergabe werden die f{\"u}r den AG anfallenden Kosten festgelegt und bilden somit die letzte gr{\"o}ßere Stellschraube f{\"u}r Preiseinsparungen.}, language = {de} } @incollection{Ferger2024, author = {Ferger, Martin}, title = {Arbeitsvorbereitung und Ablaufplanung}, series = {Zahlentafeln f{\"u}r den Baubetrieb}, booktitle = {Zahlentafeln f{\"u}r den Baubetrieb}, editor = {Krause, Thomas and Ulke, Bernd and Ferger, Martin}, publisher = {Springer Vieweg}, address = {Wiesbaden}, isbn = {978-3-658-41329-3 (Print)}, doi = {10.1007/978-3-658-41330-9_6}, pages = {299 -- 332}, year = {2024}, abstract = {Die Arbeitsvorbereitung, als ein wesentliches Aufgabengebiet des Baubetriebswesens, ist von enormer Bedeutung f{\"u}r den Erfolg eines Bauprojektes. Die Arbeitsvorbereitung l{\"a}sst sich zeitlich sowohl in der Angebotsphase (kalkulationsbegleitende Arbeitsvorbereitung), in der Vorbereitungsphase der Baustelle (von Auftragsvergabe bis Baubeginn) als auch baubegleitend einordnen.}, language = {de} } @incollection{KrauseUlke2024, author = {Krause, Thomas and Ulke, Bernd}, title = {Bauabrechnung und Mengenermittlung}, series = {Zahlentafeln f{\"u}r den Baubetrieb}, booktitle = {Zahlentafeln f{\"u}r den Baubetrieb}, editor = {Krause, Thomas and Ulke, Bernd and Ferger, Martin}, publisher = {Springer Vieweg}, address = {Wiesbaden}, isbn = {978-3-658-41329-3 (Print)}, doi = {10.1007/978-3-658-41330-9_7}, pages = {333 -- 397}, year = {2024}, abstract = {n diesem Kapitel werden die Abrechnungsvorschriften wichtiger ATV kurz, aber umfassend zusammengestellt. Einigen Abrechnungsbestimmungen f{\"u}r Einzelleistungen, die keine Nebenleistungen sind ((siehe DIN 18299 und Abschnitt 4 der jeweiligen ATV), sind mit aufgenommen worden; die ATV enthalten jedoch weitergehende Festlegungen {\"u}ber Nebenleistungen und Besondere Leistungen. Im Anschluss folgen Hinweise zu den Toleranzen im Hochbau sowie im Straßenbau.}, language = {de} } @incollection{Krause2024, author = {Krause, Thomas}, title = {Baumaschinen}, series = {Zahlentafeln f{\"u}r den Baubetrieb}, booktitle = {Zahlentafeln f{\"u}r den Baubetrieb}, editor = {Krause, Thomas and Ulke, Bernd and Ferger, Martin}, publisher = {Springer Vieweg}, address = {Wiesbaden}, isbn = {978-3-658-41329-3 (Print)}, doi = {10.1007/978-3-658-41330-9_8}, pages = {399 -- 498}, year = {2024}, abstract = {Die Leistungsermittlung und Bemessung von Baumaschinen f{\"u}r die folgenden Bereiche werden bearbeitet: Maschinen f{\"u}r den Betonbau, Hebezeuge, Maschinen f{\"u}r den Erdbau, Straßenbaumaschinen, R{\"u}ckbauger{\"a}te und Elemente der Baustelleneinrichtung.}, language = {de} } @incollection{Ulke2024, author = {Ulke, Bernd}, title = {Boden, Baugrube, Verbau}, series = {Zahlentafeln f{\"u}r den Baubetrieb}, booktitle = {Zahlentafeln f{\"u}r den Baubetrieb}, editor = {Krause, Thomas and Ulke, Bernd and Ferger, Martin}, publisher = {Springer Vieweg}, address = {Wiesbaden}, isbn = {978-3-658-41329-3 (Print)}, doi = {10.1007/978-3-658-41330-9_9}, pages = {499 -- 658}, year = {2024}, abstract = {Die L{\"o}sung den Baugrund betreffender Fragestellungen beginnen i. d. R. mit der Durchf{\"u}hrung von Baugrunderkundungen, um alle notwendigen Parameter zu erhalten, die f{\"u}r die Planung und Durchf{\"u}hrung von Bauvorhaben notwendig sind. Im Folgenden werden die wichtigsten Erkundungen in Abh{\"a}ngigkeit der erforderlichen G{\"u}teklasse der Proben beschrieben und vorgestellt.}, language = {de} } @techreport{Drescher2021, type = {Working Paper}, author = {Drescher, Hans Paul}, title = {Turbulence - minimum dissipation and maximum macroscopic momentum exchange}, pages = {44 Seiten}, year = {2021}, abstract = {The minimum dissipation requirement of the thermodynamics of irreversible processes is applied to characterize the existence of laminar and non-laminar, and the co-existence of laminar and turbulent flow zones. Local limitations of the different zones and three different forms of transition are defined. For the Couette flow a non-local "corpuscular" flow mechanism explains the logarithmic law-of-the-wall, maximum turbulent dimensions and a value x=0,415 for the v. K{\´a}rm{\´a}n constant. Limitations of the logarithmic law near the wall and in the centre of the experiment are interpreted.}, language = {en} } @techreport{Drescher2018, type = {Working Paper}, author = {Drescher, Hans Paul}, title = {The irreversible thermodynamic's theorem of minimum entropy production applied to the laminar and the turbulent Couette flow}, pages = {48 Seiten}, year = {2018}, abstract = {Analyzing thermodynamic non-equilibrium processes, like the laminar and turbulent fluid flow, the dissipation is a key parameter with a characteristic minimum condition. That is applied to characterize laminar and turbulent behaviour of the Couette flow, including its transition in both directions. The Couette flow is chosen as the only flow form with constant shear stress over the flow profile, being laminar, turbulent or both. The local dissipation defines quantitative and stable criteria for the transition and the existence of turbulence. There are basic results: The Navier Stokes equations cannot describe the experimental flow profiles of the turbulent Couette flow. But they are used to quantify the dissipation of turbulent fluctuation. The dissipation minimum requires turbulent structures reaching maximum macroscopic dimensions, describing turbulence as a "non-local" phenomenon. At the transition the Couette flow profiles and the shear stress change by a factor ≅ 5 due to a change of the "apparent" turbulent viscosity by a calculated factor ≅ 27. The resulting difference of the laminar and the turbulent profiles results in two different Reynolds numbers and different loci of transition, which are identified by calculation.}, language = {en} } @article{PieronekKleefeld2024, author = {Pieronek, Lukas and Kleefeld, Andreas}, title = {On trajectories of complex-valued interior transmission eigenvalues}, series = {Inverse problems and imaging : IPI}, volume = {18}, journal = {Inverse problems and imaging : IPI}, number = {2}, publisher = {AIMS}, address = {Springfield, Mo}, issn = {1930-8337 (Print)}, doi = {10.3934/ipi.2023041}, pages = {480 -- 516}, year = {2024}, abstract = {This paper investigates the interior transmission problem for homogeneous media via eigenvalue trajectories parameterized by the magnitude of the refractive index. In the case that the scatterer is the unit disk, we prove that there is a one-to-one correspondence between complex-valued interior transmission eigenvalue trajectories and Dirichlet eigenvalues of the Laplacian which turn out to be exactly the trajectorial limit points as the refractive index tends to infinity. For general simply-connected scatterers in two or three dimensions, a corresponding relation is still open, but further theoretical results and numerical studies indicate a similar connection.}, language = {en} } @article{SchoppRohrbachLangeretal.2024, author = {Schopp, Christoph and Rohrbach, Felix and Langer, Luc and Heuermann, Holger}, title = {Detection of welding wire length by active S11 measurement}, series = {IEEE Transactions on Plasma Science}, journal = {IEEE Transactions on Plasma Science}, number = {Early Access}, publisher = {IEEE}, issn = {0093-3813 (Print)}, doi = {10.1109/TPS.2024.3356659}, pages = {1 -- 6}, year = {2024}, abstract = {A novel method to determine the extruded length of a metallic wire for a directed energy deposition (DED) process using a microwave (MW) plasma jet with a straight-through wire feed is presented. The method is based on the relative comparison of the measured frequency response obtained by the large-signal scattering parameter (Hot-S) technique. In the practical working range, repeatability of less than 6\% for a nonactive plasma and 9\% for the active plasma state is found. Measurements are conducted with a focus on a simple solution to decrease the processing time and reduce the integration time of the process into the existing hardware. It is shown that monitoring a single frequency for magnitude and phase changes is sufficient to achieve good accuracy. A combination of different measurement values to determine the length is possible. The applicability to different diameter of the same material is shown as well as a contact detection of the wire and metallic substrate.}, language = {en} } @article{BoehnischBraunMuscarelloetal.2024, author = {B{\"o}hnisch, Nils and Braun, Carsten and Muscarello, Vincenzo and Marzocca, Pier}, title = {About the wing and whirl flutter of a slender wing-propeller system}, series = {Journal of Aircraft}, journal = {Journal of Aircraft}, publisher = {AIAA}, address = {Reston, Va.}, issn = {1533-3868}, doi = {10.2514/1.C037542}, pages = {1 -- 14}, year = {2024}, abstract = {Next-generation aircraft designs often incorporate multiple large propellers attached along the wingspan (distributed electric propulsion), leading to highly flexible dynamic systems that can exhibit aeroelastic instabilities. This paper introduces a validated methodology to investigate the aeroelastic instabilities of wing-propeller systems and to understand the dynamic mechanism leading to wing and whirl flutter and transition from one to the other. Factors such as nacelle positions along the wing span and chord and its propulsion system mounting stiffness are considered. Additionally, preliminary design guidelines are proposed for flutter-free wing-propeller systems applicable to novel aircraft designs. The study demonstrates how the critical speed of the wing-propeller systems is influenced by the mounting stiffness and propeller position. Weak mounting stiffnesses result in whirl flutter, while hard mounting stiffnesses lead to wing flutter. For the latter, the position of the propeller along the wing span may change the wing mode shapes and thus the flutter mechanism. Propeller positions closer to the wing tip enhance stability, but pusher configurations are more critical due to the mass distribution behind the elastic axis.}, language = {en} } @article{TurdumamatovBeldaHeuermann2024, author = {Turdumamatov, Samat and Belda, Aljoscha and Heuermann, Holger}, title = {Shaping a decoupled atmospheric pressure microwave plasma with antenna structures, Maxwell's equations, and boundary conditions}, series = {IEEE Transactions on Plasma Science}, journal = {IEEE Transactions on Plasma Science}, number = {Early Access}, publisher = {IEEE}, issn = {0093-3813 (Print)}, doi = {10.1109/TPS.2024.3383589}, pages = {1 -- 9}, year = {2024}, abstract = {This article addresses the need for an innovative technique in plasma shaping, utilizing antenna structures, Maxwell's laws, and boundary conditions within a shielded environment. The motivation lies in exploring a novel approach to efficiently generate high-energy density plasma with potential applications across various fields. Implemented in an E01 circular cavity resonator, the proposed method involves the use of an impedance and field matching device with a coaxial connector and a specially optimized monopole antenna. This setup feeds a low-loss cavity resonator, resulting in a high-energy density air plasma with a surface temperature exceeding 3500 o C, achieved with a minimal power input of 80 W. The argon plasma, resembling the shape of a simple monopole antenna with modeled complex dielectric values, offers a more energy-efficient alternative compared to traditional, power-intensive plasma shaping methods. Simulations using a commercial electromagnetic (EM) solver validate the design's effectiveness, while experimental validation underscores the method's feasibility and practical implementation. Analyzing various parameters in an argon atmosphere, including hot S -parameters and plasma beam images, the results demonstrate the successful application of this technique, suggesting its potential in coating, furnace technology, fusion, and spectroscopy applications.}, language = {en} } @article{StiemerThomaBraun2023, author = {Stiemer, Luc Nicolas and Thoma, Andreas and Braun, Carsten}, title = {MBT3D: Deep learning based multi-object tracker for bumblebee 3D flight path estimation}, series = {PLoS ONE}, volume = {18}, journal = {PLoS ONE}, number = {9}, publisher = {PLOS}, address = {San Fancisco}, issn = {1932-6203}, doi = {10.1371/journal.pone.0291415}, pages = {e0291415}, year = {2023}, abstract = {This work presents the Multi-Bees-Tracker (MBT3D) algorithm, a Python framework implementing a deep association tracker for Tracking-By-Detection, to address the challenging task of tracking flight paths of bumblebees in a social group. While tracking algorithms for bumblebees exist, they often come with intensive restrictions, such as the need for sufficient lighting, high contrast between the animal and background, absence of occlusion, significant user input, etc. Tracking flight paths of bumblebees in a social group is challenging. They suddenly adjust movements and change their appearance during different wing beat states while exhibiting significant similarities in their individual appearance. The MBT3D tracker, developed in this research, is an adaptation of an existing ant tracking algorithm for bumblebee tracking. It incorporates an offline trained appearance descriptor along with a Kalman Filter for appearance and motion matching. Different detector architectures for upstream detections (You Only Look Once (YOLOv5), Faster Region Proposal Convolutional Neural Network (Faster R-CNN), and RetinaNet) are investigated in a comparative study to optimize performance. The detection models were trained on a dataset containing 11359 labeled bumblebee images. YOLOv5 reaches an Average Precision of AP = 53, 8\%, Faster R-CNN achieves AP = 45, 3\% and RetinaNet AP = 38, 4\% on the bumblebee validation dataset, which consists of 1323 labeled bumblebee images. The tracker's appearance model is trained on 144 samples. The tracker (with Faster R-CNN detections) reaches a Multiple Object Tracking Accuracy MOTA = 93, 5\% and a Multiple Object Tracking Precision MOTP = 75, 6\% on a validation dataset containing 2000 images, competing with state-of-the-art computer vision methods. The framework allows reliable tracking of different bumblebees in the same video stream with rarely occurring identity switches (IDS). MBT3D has much lower IDS than other commonly used algorithms, with one of the lowest false positive rates, competing with state-of-the-art animal tracking algorithms. The developed framework reconstructs the 3-dimensional (3D) flight paths of the bumblebees by triangulation. It also handles and compares two alternative stereo camera pairs if desired.}, language = {en} } @article{BiewendtBlaschkeBoehnert2021, author = {Biewendt, Marcel and Blaschke, Florian and B{\"o}hnert, Arno}, title = {A review of contemporary challenges in business culture}, series = {International Journal of Applied Research in Business and Management}, volume = {2}, journal = {International Journal of Applied Research in Business and Management}, number = {1}, publisher = {Wohllebe \& Ross Publishing}, address = {Hamburg}, issn = {2700-8983}, doi = {10.51137/ijarbm.2021.2.1.1}, pages = {1 -- 12}, year = {2021}, abstract = {The following article deals with the basic principles of intercultural management and possible improvements in terms of cultural, ethnic and gender diversification. The results are exemplarily applied to a bank located in Germany. The aim of this paper is to find out to what extent intercultural management could improve the productivity of Relatos-Bank in dealing with foreign employees or employees with a different cultural background. To achieve this goal, the authors con-duct a literature research. The main sources of information are books, journal articles and internet sources. It becomes clear that especially the different perceptions of different generations have a potential for conflict, which can be counteracted by applying presented scientific models. Equalizing the salaries of female and male employees and equalizing the rights and distribution of power could also be the key to becoming an open-minded, dynamic and fair organization that is pre-pared for the rapidly changing environment in which it operates.}, language = {en} } @article{Biewendt2020, author = {Biewendt, Marcel}, title = {Sustainable development: A quantitative analysis regarding the impact of resource rents on state welfare from 2002 to 2017}, series = {SocioEconomic Challenges}, volume = {4}, journal = {SocioEconomic Challenges}, number = {4}, publisher = {ARMG Publishing}, address = {Sumy}, issn = {2520-6214}, doi = {10.21272/sec.4(4).119-131.2020}, pages = {119 -- 131}, year = {2020}, abstract = {This paper uses a quantitative analysis to examine the interdependence and impact of resource rents on socio-economic development from 2002 to 2017. Nigeria and Norway have been chosen as reference countries due to their abundance of natural resources by similar economic performance, while the ranking in the Human Development Index differs dramatically. As the Human Development Index provides insight into a country's cultural and socio-economic characteristics and development in addition to economic indicators, it allows a comparison of the two countries. The hypothesis presented and discussed in this paper was researched before. A qualitative research approach was used in the author's master's thesis "The Human Development Index (HDI) as a Reflection of Resource Abundance (using Nigeria and Norway as a case study)" in 2018. The management of scarce resources is an important aspect in the development of modern countries and those on the threshold of becoming industrialised nations. The effects of a mistaken resource management are not only of a purely economic nature but also of a social and socio-economic nature. In order to present a partial aspect of these dependencies and influences this paper uses a quantitative analysis to examine the interdependence and impact of resource rents on socio-economic development from 2002 to 2017. Nigeria and Norway have been chosen as reference countries due to their abundance of natural resources by similar economic performance, while the ranking in the Human Development Index differs significantly. As the Human Development Index provides insight into a country's cultural and socio-economic characteristics and development in addition to economic indicators, it allows a comparison of the two countries. This paper found out in a holistic perspective that (not or poorly managed) resource wealth in itself has a negative impact on socio-economic development and significantly reduces the productivity of the citizens of a state. This is expressed in particular for the years 2002 till 2017 in a negative correlation of GDP per capita and HDI value with the share respectively the size of resources in the GDP of a country.}, language = {en} } @article{AdelsMonakhova2024, author = {Adels, Klaudia and Monakhova, Yulia}, title = {Low-field NMR spectroscopic study of e-cigarettes: Is determination of only nicotine and organic carrier solvents possible?}, series = {Microchemical Journal}, volume = {203}, journal = {Microchemical Journal}, publisher = {Elsevier}, address = {Amsterdam}, issn = {1095-9149}, doi = {10.1016/j.microc.2024.110859}, pages = {9 Seiten}, year = {2024}, abstract = {Electronic cigarettes (e-cigarettes) have become popular worldwide with the market growing exponentially in some countries. The absence of product standards and safety regulations requires urgent development of analytical methodologies for the holistic control of the growing diversity of such products. An approach based on low-field nuclear magnetic resonance (LF-NMR) at 80 MHz is presented for the simultaneous determination of key parameters: carrier solvents (vegetable glycerine (VG), propylene glycol (PG) and water), total nicotine as well as free-base nicotine fraction. Moreover, qualitative and quantitative determination of fourteen weak organic acids deliberately added to enhance sensory characteristics of e-cigarettes was possible. In most cases these parameters can be rapidly and conveniently determined without using any sample manipulation such as dilution, extraction or derivatization steps. The method was applied for 37 authentic e-cigarettes samples. In particular, eight different organic acids with the content up to 56 mg/mL were detected. Due to its simplicity, the method can be used in routine regulatory control as well as to study release behaviour of nicotine and other e-cigarettes constituents in different products.}, language = {en} } @article{MoehrenBergmannJanseretal.2024, author = {M{\"o}hren, Felix and Bergmann, Ole and Janser, Frank and Braun, Carsten}, title = {Assessment of structural mechanical effects related to torsional deformations of propellers}, series = {CEAS Aeronautical Journal}, journal = {CEAS Aeronautical Journal}, publisher = {Springer}, address = {Wien}, issn = {1869-5590 (eISSN)}, doi = {10.1007/s13272-024-00737-7}, pages = {22 Seiten}, year = {2024}, abstract = {Lifting propellers are of increasing interest for Advanced Air Mobility. All propellers and rotors are initially twisted beams, showing significant extension-twist coupling and centrifugal twisting. Torsional deformations severely impact aerodynamic performance. This paper presents a novel approach to assess different reasons for torsional deformations. A reduced-order model runs large parameter sweeps with algebraic formulations and numerical solution procedures. Generic beams represent three different propeller types for General Aviation, Commercial Aviation, and Advanced Air Mobility. Simulations include solid and hollow cross-sections made of aluminum, steel, and carbon fiber-reinforced polymer. The investigation shows that centrifugal twisting moments depend on both the elastic and initial twist. The determination of the centrifugal twisting moment solely based on the initial twist suffers from errors exceeding 5\% in some cases. The nonlinear parts of the torsional rigidity do not significantly impact the overall torsional rigidity for the investigated propeller types. The extension-twist coupling related to the initial and elastic twist in combination with tension forces significantly impacts the net cross-sectional torsional loads. While the increase in torsional stiffness due to initial twist contributes to the overall stiffness for General and Commercial Aviation propellers, its contribution to the lift propeller's stiffness is limited. The paper closes with the presentation of approximations for each effect identified as significant. Numerical evaluations are necessary to determine each effect for inhomogeneous cross-sections made of anisotropic material.}, language = {en} } @article{ThomaGardiFisheretal.2024, author = {Thoma, Andreas and Gardi, Alessandro and Fisher, Alex and Braun, Carsten}, title = {Improving local path planning for UAV flight in challenging environments by refining cost function weights}, series = {CEAS Aeronautical Journal}, journal = {CEAS Aeronautical Journal}, publisher = {Springer}, address = {Wien}, issn = {1869-5590 (eISSN)}, doi = {10.1007/s13272-024-00741-x}, pages = {12 Seiten}, year = {2024}, abstract = {Unmanned Aerial Vehicles (UAV) constantly gain in versatility. However, more reliable path planning algorithms are required until full autonomous UAV operation is possible. This work investigates the algorithm 3DVFH* and analyses its dependency on its cost function weights in 2400 environments. The analysis shows that the 3DVFH* can find a suitable path in every environment. However, a particular type of environment requires a specific choice of cost function weights. For minimal failure, probability interdependencies between the weights of the cost function have to be considered. This dependency reduces the number of control parameters and simplifies the usage of the 3DVFH*. Weights for costs associated with vertical evasion (pitch cost) and vicinity to obstacles (obstacle cost) have the highest influence on the failure probability of the local path planner. Environments with mainly very tall buildings (like large American city centres) require a preference for horizontal avoidance manoeuvres (achieved with high pitch cost weights). In contrast, environments with medium-to-low buildings (like European city centres) benefit from vertical avoidance manoeuvres (achieved with low pitch cost weights). The cost of the vicinity to obstacles also plays an essential role and must be chosen adequately for the environment. Choosing these two weights ideal is sufficient to reduce the failure probability below 10\%.}, language = {en} } @article{BoehnertBlaschkeBiewendt2023, author = {B{\"o}hnert, Arno and Blaschke, Florian and Biewendt, Marcel}, title = {Impact of sustainability on the strategic direction of luxury companies}, series = {European Journal of Marketing and Economics}, volume = {6}, journal = {European Journal of Marketing and Economics}, number = {1}, publisher = {Revistia}, address = {London}, issn = {2601-8659}, pages = {70 -- 85}, year = {2023}, abstract = {Today's society is undergoing a paradigm shift driven by the megatrend of sustainability. This undeniably affects all areas of Western life. This paper aims to find out how the luxury industry is dealing with this change and what adjustments are made by the companies. For this purpose, interviews were conducted with managers from the luxury industry, in which they were asked about specific measures taken by their companies as well as trends in the industry. In a subsequent evaluation, the trends in the luxury industry were summarized for the areas of ecological, social, and economic sustainability. It was found that the area of environmental sustainability is significantly more focused than the other sub-areas. Furthermore, the need for a customer survey to validate the industry-based measures was identified.}, language = {en} } @article{BiewendtBlaschkeBoehnert2021, author = {Biewendt, Marcel and Blaschke, Florian and B{\"o}hnert, Arno}, title = {Motivational factors in organisational change}, series = {SocioEconomic Challenges}, volume = {5}, journal = {SocioEconomic Challenges}, number = {3}, publisher = {ARMG}, address = {Sumy}, issn = {2520-6214}, doi = {10.21272/sec.5(3).15-27.2021}, pages = {15 -- 27}, year = {2021}, abstract = {The presented paper gives an overview of the most important and most common theories and concepts from the economic field of organisational change and is also enriched with quantitative publication data, which underlines the relevance of the topic. In particular, the topic presented is interwoven in an interdisciplinary way with economic psychological models, which are underpinned within the models with content from leading scholars in the field. The pace of change in companies is accelerating, as is technological change in our society. Adaptations of the corporate structure, but also of management techniques and tasks, are therefore indispensable. This includes not only the right approaches to employee motivation, but also the correct use of intrinsic and extrinsic motivational factors. Based on the hypothesis put forward by the scientist and researcher Rollinson in his book "Organisational behaviour and analysis" that managers believe motivational resources are available at all times, socio-economic and economic psychological theories are contrasted here in order to critically examine this statement. In addition, a fictitious company was created as a model for this work in order to illustrate the effects of motivational deficits in practice. In this context, the theories presented are applied to concrete problems within the model and conclusions are drawn about their influence and applicability. This led to the conclusion that motivation is a very individual challenge for each employee, which requires adapted and personalised approaches. On the other hand, the recommendations for action for supervisors in the case of motivation deficits also cannot be answered in a blanket manner, but can only be solved with the help of professional, expert-supported processing due to the economic-psychological realities of motivation. Identifying, analysing and remedying individual employee motivation deficits is, according to the authors, a problem and a challenge of great importance, especially in the context of rapidly changing ecosystems in modern companies, as motivation also influences other factors such as individual productivity. The authors therefore conclude that good motivation through the individual and customised promotion and further training of employees is an important point for achieving important corporate goals in order to remain competitive on the one hand and to create a productive and pleasant working environment on the other.}, language = {en} } @article{TixMollKrafftetal.2024, author = {Tix, Julian and Moll, Fabian and Krafft, Simone and Betsch, Matthias and Tippk{\"o}tter, Nils}, title = {Hydrogen production from enzymatic pretreated organic waste with thermotoga neapolitana}, series = {Energies}, volume = {17}, journal = {Energies}, number = {12}, publisher = {MDPI}, address = {Basel}, issn = {1996-1073}, doi = {10.3390/en17122938}, pages = {20 Seiten}, year = {2024}, abstract = {Biomass from various types of organic waste was tested for possible use in hydrogen production. The composition consisted of lignified samples, green waste, and kitchen scraps such as fruit and vegetable peels and leftover food. For this purpose, the enzymatic pretreatment of organic waste with a combination of five different hydrolytic enzymes (cellulase, amylase, glucoamylase, pectinase and xylase) was investigated to determine its ability to produce hydrogen (H2) with the hydrolyzate produced here. In course, the anaerobic rod-shaped bacterium T. neapolitana was used for H2 production. First, the enzymes were investigated using different substrates in preliminary experiments. Subsequently, hydrolyses were carried out using different types of organic waste. In the hydrolysis carried out here for 48 h, an increase in glucose concentration of 481\% was measured for waste loads containing starch, corresponding to a glucose concentration at the end of hydrolysis of 7.5 g·L-1. In the subsequent set fermentation in serum bottles, a H2 yield of 1.26 mmol H2 was obtained in the overhead space when Terrific Broth Medium with glucose and yeast extract (TBGY medium) was used. When hydrolyzed organic waste was used, even a H2 yield of 1.37 mmol could be achieved in the overhead space. In addition, a dedicated reactor system for the anaerobic fermentation of T. neapolitana to produce H2 was developed. The bioreactor developed here can ferment anaerobically with a very low loss of produced gas. Here, after 24 h, a hydrogen concentration of 83\% could be measured in the overhead space.}, language = {en} } @article{BlockViebahnJungbluth2024, author = {Block, Simon and Viebahn, Peter and Jungbluth, Christian}, title = {Analysing direct air capture for enabling negative emissions in Germany: an assessment of the resource requirements and costs of a potential rollout in 2045}, series = {Frontiers in Climate}, volume = {6}, journal = {Frontiers in Climate}, publisher = {Frontiers}, address = {Lausanne}, issn = {2624-9553}, doi = {10.3389/fclim.2024.1353939}, pages = {18 Seiten}, year = {2024}, abstract = {Direct air capture (DAC) combined with subsequent storage (DACCS) is discussed as one promising carbon dioxide removal option. The aim of this paper is to analyse and comparatively classify the resource consumption (land use, renewable energy and water) and costs of possible DAC implementation pathways for Germany. The paths are based on a selected, existing climate neutrality scenario that requires the removal of 20 Mt of carbon dioxide (CO2) per year by DACCS from 2045. The analysis focuses on the so-called "low-temperature" DAC process, which might be more advantageous for Germany than the "high-temperature" one. In four case studies, we examine potential sites in northern, central and southern Germany, thereby using the most suitable renewable energies for electricity and heat generation. We show that the deployment of DAC results in large-scale land use and high energy needs. The land use in the range of 167-353 km2 results mainly from the area required for renewable energy generation. The total electrical energy demand of 14.4 TWh per year, of which 46\% is needed to operate heat pumps to supply the heat demand of the DAC process, corresponds to around 1.4\% of Germany's envisaged electricity demand in 2045. 20 Mt of water are provided yearly, corresponding to 40\% of the city of Cologne's water demand (1.1 million inhabitants). The capture of CO2 (DAC) incurs levelised costs of 125-138 EUR per tonne of CO2, whereby the provision of the required energy via photovoltaics in southern Germany represents the lowest value of the four case studies. This does not include the costs associated with balancing its volatility. Taking into account transporting the CO2 via pipeline to the port of Wilhelmshaven, followed by transporting and sequestering the CO2 in geological storage sites in the Norwegian North Sea (DACCS), the levelised costs increase to 161-176 EUR/tCO2. Due to the longer transport distances from southern and central Germany, a northern German site using wind turbines would be the most favourable.}, language = {en} } @masterthesis{Ackermann2024, type = {Bachelor Thesis}, author = {Ackermann, Vincent}, title = {Filos : Design eines Front-Ends f{\"u}r das robotergef{\"u}hrte Laser-Osteotom-System STELLA.}, publisher = {FH Aachen}, address = {Aachen}, pages = {70 Seiten}, year = {2024}, abstract = {In der Abschlussarbeit „FILOS" wurde in Zusammenarbeit mit dem Fraunhofer-Institut f{\"u}r Lasertechnik (ILT) ein Front-End f{\"u}r das laserbasierte Osteotom STELLA entwickelt. STELLA soll Kraniotomie (das Er{\"o}ffnen des Sch{\"a}dels) im wachen Zustand erm{\"o}glichen und erfordert eine benutzerfreundliche Bedienungsplattform sowie ein funktionales und {\"a}sthetisches Design. Das Ziel von „FILOS" war es, ein Geh{\"a}use zu entwerfen, das den medizinischen Anforderungen entspricht, und ein Bedienkonzept zu entwickeln, dass die Akzeptanz bei Patient:innen und Anwender:innen f{\"o}rdert. Durch Expert:innen-Interviews mit Neurochirurg:innen und enge Zusammenarbeit mit dem ILT wurde ein durchdachtes Design entwickelt. Dieses soll den Anforderungen der Anwender:innen gerecht werden, das zuk{\"u}nftige Operationssystem repr{\"a}sentieren und somit einen Mehrwert in der Medizin schaffen.}, language = {de} } @masterthesis{Bartz2024, type = {Bachelor Thesis}, author = {Bartz, Markus}, title = {Dupiano : Ein aus einem Bauelement auffaltbarer Keyboradst{\"a}nder mit dem Erscheinungsbild eines akustischen Klavieres.}, publisher = {FH Aachen}, address = {Aachen}, pages = {123 Seiten}, year = {2024}, abstract = {Klavierspielende K{\"u}nstlerinnen und K{\"u}nstler finden sich auf der B{\"u}hne meist an einer Kombination aus Keyboard und Keyboardst{\"a}nder wieder. Zwar kann der Klang eines Klaviers technisch brillant simuliert werden, jedoch verliert das B{\"u}hnenbild den Mehrwert eines traditionellen Klaviers. Um diesem Verlust von Authentizit{\"a}t und Wohlgef{\"u}hl auf der B{\"u}hne endlich etwas entgegenzusetzen, soll ein "dupiano" g{\"a}ngige Keyboardst{\"a}nder ersetzen und s{\"a}mtliche Keyboards in das Erscheinungsbild eines akustischen Klaviers h{\"u}llen. Dadurch sollen auch die visuellen Eindr{\"u}cke, verkn{\"u}pft mit den akustischen, an Authentizit{\"a}t gewinnen und den Klavierauftritt vervollst{\"a}ndigen. Es ist leicht, stabil und ohne Werkzeug in unter 10 Sekunden aufbaubar. Auch der Abbau geschieht in unter 10 Sekunden. Verstaut werden kann es von einer Person in jedem Kofferraum. "dupiano" - was nach Klavier klingt, soll auch so aussehen!}, language = {de} } @article{BiewendtBoehnertBlaschke2020, author = {Biewendt, Marcel and B{\"o}hnert, Arno and Blaschke, Florian}, title = {The repercussions of the digital twin in the automotive industry on the new marketing logic}, series = {European Journal of Marketing and Economics}, volume = {4}, journal = {European Journal of Marketing and Economics}, number = {1}, publisher = {Revistia}, address = {London}, issn = {2601-8659}, doi = {10.26417/229eim64f}, pages = {68 -- 73}, year = {2020}, abstract = {Rapid development of virtual and data acquisition technology makes Digital Twin Technology (DT) one of the fundamental areas of research, while DT is one of the most promissory developments for the achievement of Industry 4.0. 48\% percent of organisations implementing the Internet of Things are already using DT or plan to use DT in 2020. The global market for DT is expected to grow by 38 percent annually, reaching USD16 billion by 2023. In addition, the number of participating organisations using digital twins is expected to triple by 2022. DTs are characterised by the integration between physical and virtual spaces. The driving idea for DT is to develop, test and build our devices in a virtual environment. The objective of this paper is to study the impact of DT in the automotive industry on the new marketing logic. This paper outlines the current challenges and possible directions for the future DT in marketing. This paper will be helpful for managers in the industry to use the advantages and potentials of DT.}, language = {en} } @article{BiewendtBlaschkeBoehnert2020, author = {Biewendt, Marcel and Blaschke, Florian and B{\"o}hnert, Arno}, title = {An evaluation of corporate sustainability in context of the Jevons paradox}, series = {SocioEconomic Challenges}, volume = {4}, journal = {SocioEconomic Challenges}, number = {3}, publisher = {ARMG Publishing}, address = {Sumy}, issn = {2520-6214}, doi = {10.21272/sec.4(3).46-65.2020}, pages = {46 -- 65}, year = {2020}, abstract = {The successful implementation and continuous development of sustainable corporate-level solutions is a challenge. These are endeavours in which social, environmental, and financial aspects must be weighed against each other. They can prove difficult to handle and, in some cases, almost unrealistic. Concepts such as green controlling, IT, and manufacturing look promising and are constantly evolving. This paper aims to achieve a better understanding of the field of corporate sustainability (CS). It will evaluate the hypothesis by which Corporate Sustainability thrives, via being efficient, increasing the performance, and raising the value of the input of the enterprises to the resources used. In fact, Corporate Sustainability on the surface could seem to contradict the idea, which supports the understanding that it encourages the reduction of the heavy reliance on the use of natural resources, the overall environmental impact, and above all, their protection. To understand how the contradictory notion of CS came about, in this part of the paper, the emphasis is placed on providing useful insight to this regard. The first part of this paper summarizes various definitions, organizational theories, and measures used for CS and its derivatives like green controlling, IT, and manufacturing. Second, a case study is given that combines the aforementioned sustainability models. In addition to evaluating the hypothesis, the overarching objective of this paper is to demonstrate the use of green controlling, IT, and manufacturing in the corporate sector. Furthermore, this paper outlines the current challenges and possible directions for CS in the future.}, language = {en} } @article{BiewendtBlaschkeBoehnert2020, author = {Biewendt, Marcel and Blaschke, Florian and B{\"o}hnert, Arno}, title = {The rebound effect - a systematic review of the current state of affairs}, series = {European Journal of Economics and Business Studies}, volume = {6}, journal = {European Journal of Economics and Business Studies}, number = {1}, publisher = {Revistia}, address = {London}, issn = {2601-8659}, doi = {10.26417/134nvy47z}, pages = {106 -- 120}, year = {2020}, abstract = {This publication is intended to present the current state of research on the rebound effect. First, a systematic literature review is carried out to outline (current) scientific models and theories. Research Question 1 follows with a mathematical introduction of the rebound effect, which shows the interdependence of consumer behaviour, technological progress, and interwoven effects for both. Thereupon, the research field is analysed for gaps and limitations by a systematic literature review. To ensure quantitative and qualitative results, a review protocol is used that integrates two different stages and covers all relevant publications released between 2000 and 2019. Accordingly, 392 publications were identified that deal with the rebound effect. These papers were reviewed to obtain relevant information on the two research questions. The literature review shows that research on the rebound effect is not yet comprehensive and focuses mainly on the effect itself rather than solutions to avoid it. Research Question 2 finds that the main gap, and thus the limitations, is that not much research has been published on the actual avoidance of the rebound effect yet. This is a major limitation for practical application by decision-makers and politicians. Therefore, a theoretical analysis was carried out to identify potential theories and ideas to avoid the rebound effect. The most obvious idea to solve this problem is the theory of a Steady-State Economy (SSE), which has been described and reviewed.}, language = {en} } @incollection{SchneiderWisselinkCzarneckietal.2024, author = {Schneider, Dominik and Wisselink, Frank and Czarnecki, Christian and N{\"o}lle, Nikolai}, title = {Benefits and framework conditions for information-driven business models concerning the Internet of Things}, series = {Digitalization in companies}, booktitle = {Digitalization in companies}, publisher = {Springer}, address = {Wiesbaden}, isbn = {978-3-658-39093-8 (Print)}, doi = {10.1007/978-3-658-39094-5_5}, pages = {59 -- 75}, year = {2024}, abstract = {In the context of the increasing digitalization, the Internet of Things (IoT) is seen as a technological driver through which completely new business models can emerge in the interaction of different players. Identified key players include traditional industrial companies, municipalities and telecommunications companies. The latter, by providing connectivity, ensure that small devices with tiny batteries can be connected almost anywhere and directly to the Internet. There are already many IoT use cases on the market that provide simplification for end users, such as Philips Hue Tap. In addition to business models based on connectivity, there is great potential for information-driven business models that can support or enhance existing business models. One example is the IoT use case Park and Joy, which uses sensors to connect parking spaces and inform drivers about available parking spaces in real time. Information-driven business models can be based on data generated in IoT use cases. For example, a telecommunications company can add value by deriving more decision-relevant information - called insights - from data that is used to increase decision agility. In addition, insights can be monetized. The monetization of insights can only be sustainable, if careful attention is taken and frameworks are considered. In this chapter, the concept of information-driven business models is explained and illustrated with the concrete use case Park and Joy. In addition, the benefits, risks and framework conditions are discussed.}, language = {en} } @misc{StaubTippkoetterSucketal.2010, author = {Staub, C. and Tippk{\"o}tter, Nils and Suck, K. and Sohling, U. and Ulber, Roland}, title = {Chromatographische Aufarbeitung von Molkekonzentrat mittels mineralischer Granulate}, series = {Chemie Ingenieur Technik}, volume = {82}, journal = {Chemie Ingenieur Technik}, number = {9}, publisher = {Wiley-VCH}, address = {Weinheim}, issn = {0009-286X}, doi = {10.1002/cite.201050322}, pages = {1588 -- 1589}, year = {2010}, abstract = {Molke f{\"a}llt im Rahmen der K{\"a}seherstellung allein in Deutschland in Mengen von {\"u}ber 11 Mio. Tonnen j{\"a}hrlich an. Dieses Nebenprodukt wurde trotz seines Reichtums an Milchzucker und Proteinen lange Zeit kaum industriell weiterverarbeitet und stellte ein bedeutendes Problem bei der Abwasserreinigung dar. Derzeit kommen meist kosten- und reinigungsintensive Membranfiltrationsverfahren bei der Auftrennung von Molke in ihre Hauptkomponenten Lactose und Molkenprotein zum Einsatz. Die Produkte finden vorwiegend in der Nahrungsmittelindustrie Anwendung als S{\"u}ßungsmittel, Proteinzusatz oder Texturbildner. Die Mehrheit des Proteins wird dabei als Konzentrat bzw. Proteinpulver verarbeitet. Wegen der antibakteriellen, antiviralen und weiteren wertvollen physiologischen Eigenschaften der Molkeproteine stellt eine weitere Aufreinigung der einzelnen Molkeproteine f{\"u}r die pharmazeutische Industrie einen naheliegenden zus{\"a}tzlichen Wertsch{\"o}pfungsschritt dar. In Kooperation mit der S{\"u}d Chemie AG wurde damit begonnen, ein Verfahren zu entwickeln, das kosteng{\"u}nstige mineralische Adsorbentien verwendet. Bisher konnte die Abtrennung von Lactose von den Molkenproteinen aus verd{\"u}nntem Molkekonzentrat in einem Verfahrensschritt ohne Vorbehandlung des Rohstoffs erfolgreich realisiert werden. Aktuelle Arbeiten besch{\"a}ftigen sich mit der Verbesserung der Proteinbindekapazit{\"a}tund chromatographischen Proteinauftrennung sowie dem Upscaling zum direkten Einsatz von Molkekonzentrat ohne Vorverd{\"u}nnung.}, language = {de} } @misc{TippkoetterZhangPothetal.2010, author = {Tippk{\"o}tter, Nils and Zhang, M. and Poth, S. and Ulber, Roland}, title = {Enzymatische Lignindegradierung unter Einsatz eines Optimierungsalgorithmus}, series = {Chemie Ingenieur Technik}, volume = {82}, journal = {Chemie Ingenieur Technik}, number = {9}, publisher = {Wiley-VCH}, address = {Weinheim}, issn = {0009-286X}, doi = {10.1002/cite.201050707}, pages = {1601 -- 1602}, year = {2010}, abstract = {Lignine bestehen aus einem hochgradig vernetzten Polymer phenolischer Grundeinheiten. Diese Verbindungen sind eine Quelle vielversprechender chemischer Grundbausteine. Auch die enzymatische Modifikation der Materialeigenschaften des Lignins ist f{\"u}r dessen Anwendung von Interesse. Aufgrund der verschiedenen Bindungstypen im Lignin ist eine Auftrennung mit nur einem Enzym unwahrscheinlich. Vielmehr sind verschiedene mediatorgest{\"u}tzte Reaktionen notwendig. Pilze, wie z.B. T. versicolor, nutzen Enzymkombinationen zum Aufschluss des Lignins. Hierbei kommen Laccase, Ligninperoxidase und Manganperoxidase zum Einsatz. Die optimale Kombination der Enzyme und ihrer Mediatoren bzw. Stabilisatoren ist Ziel der Untersuchungen. Aufgrund der großen Parameteranzahl wurde ein genetischer Algorithmus eingesetzt. Als Versuchsparameter wurden gew{\"a}hlt: die Verh{\"a}ltnisse der Enzyme, Ligninmasse, Konzentrationen an Eisen-, Mangan-, Oxalat-Ionen, ABTS, Violurs{\"a}ure und H₂O₂. Somit werden elf Parameter simultan optimiert. Als Algorithmus wurde ein Programm mit variabler Genkodierung entwickelt. Die Umsetzung des Lignins wird dabei {\"u}ber den verfolgt. Zurzeit ist ein enzymatischer Umsatz von 12\% m{\"o}glich. Als Referenz wurde eine chemische Lignindegradierung mit einem Umsatzvon 37\% etabliert. Die sechs Generationen des Algorithmus zeigen eine Kongruenz der Enzymkonzentrationen von LiP, MnP und VeP, w{\"a}hrend Laccase keinen Einfluss hat. Des Weiteren beeinflussen die Konzentrationen von Mangan und Oxalat die Umsetzung, w{\"a}hrend die Variation von ABTS- und H₂O₂ nur eine geringe Auswirkung hat.}, language = {de} } @misc{PasteurLudwigTippkoetteretal.2010, author = {Pasteur, A. and Ludwig, B. and Tippk{\"o}tter, Nils and Diller, R. and Kampeis, P. and Ulber, Roland}, title = {Aufarbeitung von β-Lactamantibiotika mittels selektiver, magnetischer Adsorbermaterialien}, series = {Chemie Ingenieur Technik}, volume = {82}, journal = {Chemie Ingenieur Technik}, number = {9}, publisher = {Wiley-VCH}, address = {Weinheim}, doi = {10.1002/cite.201050270}, pages = {1587}, year = {2010}, abstract = {b-Lactame geh{\"o}ren zu den wirkungsvollsten Antibiotika, jedoch lassen sich viele nur schwierig fermentativ erzeugen. Ein Problem bei der fermentativen Produktion ist die Hydrolyse des Lactamrings im w{\"a}ssrigen Milieu. Das Ziel des von der DBU gef{\"o}rderten Projekts ist die selektive In-situ-Adsorption der b-Lactamantibiotika unter anschließender magnetischer Separation. Durch die Isolation im Hochgradientenmagnetseparator (HGMS) ist eine Fest-fest-fl{\"u}ssig-Trennung und somit ein erheblicher Zeitgewinn im Downstreamprozess m{\"o}glich. Zus{\"a}tzlich kommt es zur Einsparung an L{\"o}sungsmittel und Energie, was neben Reduzierung der Antibiotikahydrolyse auch in {\"o}kologischer Hinsicht einen interessanten Aspekt darstellt. Als Tr{\"a}germaterial f{\"u}r die Adsorbermatrix werden magnetisierbare Eisenoxidpartikel eingesetzt, die in einer Silikamatrix eingebettet sind. Diese Adsorber sollen auf Selektivit{\"a}t in Wasser und verschiedenen Medien getestet werden. Zus{\"a}tzlich werden die Abbauprodukte des b-Lactams analysiert, um eine Aussage {\"u}ber die Stabilisierung des Antibiotikums durch die selektiven Adsorber treffen zu k{\"o}nnen. Diese Ergebnisse werden mit kommerziell erh{\"a}ltlichen Adsorbern verglichen. Die Aufreinigung der Antibiotika soll direkt aus der Fermentationsbr{\"u}he erfolgen. Um die Trennung der magnetischen, selektiven Adsorber von der Biomasse zu gew{\"a}hrleisten, soll der HGMS in die Fermentation integriert werden. Das filament{\"o}se Wachstum des Mikroorganismus erfordert eine Neuauslegung der Filtermatrix.}, language = {de} } @misc{PothMonzonTippkoetteretal.2010, author = {Poth, S. and Monzon, M. and Tippk{\"o}tter, Nils and Ulber, Roland}, title = {Lignocellulose-Bioraffinerie: Simultane Verzuckerung und Fermentation}, series = {Chemie Ingenieur Technik}, volume = {82}, journal = {Chemie Ingenieur Technik}, number = {9}, publisher = {Wiley-VCH}, address = {Weinheim}, doi = {10.1002/cite.201050360}, pages = {1568}, year = {2010}, abstract = {Die am h{\"a}ufigsten genutzten Rohstoffe f{\"u}r die Produktion von Treibstoffen und Chemikalien sind fossilen Ursprungs. Da diese limitiert sind, werden im Hinblick auf die Nachhaltigkeit alternative, erneuerbare Rohstoffquellen intensiv untersucht. Vielversprechend in diesem Kontext sind die in Lignocellulose enthaltenen Zucker, die beispielsweise zur Produktion von Ethanol genutzt werden k{\"o}nnen. In der Regel sind f{\"u}r eine Lig-nocellulose-Bioraffinerie mehrere Prozessschritte notwendig: Vorbehandlung, Verzuckerung und Fermentation. Um diesen Prozess einfacher zu gestalten, ist es m{\"o}glich, die Verzuckerung und die Fermentation in einem Schritt durchzuf{\"u}hren (SSF). Als Substrat wird hier Cellulose-Faserstoff verwendet, der durch das Organosolv-Verfahren aufgeschlossen wurde. Die Hydrolyse erfolgt mit kommerziell erh{\"a}ltlichen Enzymen und f{\"u}r die Fermentation zu Ethanol werden zwei Hefen verwendet. Beim SSF-Verfahren konnte, im Vergleich zur entkoppelten Verfahrensweise, trotz bestehender Unterschiede in den Temperatur-Optima von Enzymen und Hefen eine Steigerung in der Ethanol-Ausbeute von 0,15 auf 0,2 gg⁻¹ beobachtet werden. Um wirtschaftliche Ausbeuten und Konzentrationen des Produkts erzielen zu k{\"o}nnen, ist es notwendig den Prozess weiter zu optimieren. Im Einzelfall muss {\"u}berpr{\"u}ft werden, ob diese Verfahrensweise auch f{\"u}r die Produktion anderer interessanter Stoffe (wie Itacons{\"a}ure, Bernsteins{\"a}ure) geeignet ist.}, language = {de} } @masterthesis{Gros2024, type = {Bachelor Thesis}, author = {Gros, Isabella}, title = {Depressed Furniture : eine abstrakte {\"U}bersetzung von Depressionen in M{\"o}blierung}, publisher = {FH Aachen}, address = {Aachen}, school = {Fachhochschule Aachen}, pages = {367 Seiten}, year = {2024}, abstract = {Depressed Furniture ist eine abstrakte {\"U}bersetzung von Depressionen in M{\"o}blierung. Es handelt sich um eine Rauminstallation von f{\"u}nf Leuchten, die der Erkrankung in einem un{\"u}blichen Kontext eine Plattform gibt. Dadurch stellt das Projekt eine Schnittstelle zwischen Kunst, Design und Gesellschaft dar. Jede Leuchte verk{\"o}rpert eine Empfindung, mit der sich ein Großteil der Betroffenen identifizieren kann. Es wird Bewusstsein f{\"u}r die Komplexit{\"a}t der Krankheit geschaffen und das Tabu um mentale Krankheiten gebrochen. Neben der Regular Collection k{\"o}nnen auch Tischvarianten (Compact Collection) erworben werden. Depressed Furniture zeigt, dass es durchaus m{\"o}glich ist, eine unsch{\"o}ne Thematik zu abstrahieren und ihr neutral zu begegnen. Es verdeutlicht, wie Design dazu beitragen kann, sensible Themen auf kreative Weise zu kommunizieren.}, language = {de} } @misc{KuthanAlKaidyTippkoetter2016, author = {Kuthan, K. and Al-Kaidy, H. and Tippk{\"o}tter, Nils}, title = {Tropfenbasierte Enzymreaktionen auf Glasoberfl{\"a}chen im μL-Maßstab mit ortsaufgel{\"o}ster pL-Dosierung der Reaktanden}, series = {Chemie Ingenieur Technik}, volume = {88}, journal = {Chemie Ingenieur Technik}, number = {9}, publisher = {Wiley-VCH}, address = {Weinheim}, doi = {10.1002/cite.201650117}, pages = {1336 -- 1337}, year = {2016}, abstract = {Mit der Entwicklung w{\"a}ssriger Tropfen, die mit einer sch{\"u}tzenden H{\"u}lle magnetisierbarer, hydrophober Partikel umgeben sind, ergeben sich neue M{\"o}glichkeiten im Bereich der Mikrofluidik. So k{\"o}nnen die Tropfen als fl{\"u}ssige Mikroreaktoren eingesetzt werden. Der w{\"a}ssrige Kern dieser Mikroreaktoren besteht aus einer Substratl{\"o}sung f{\"u}r enzymatische Umsetzungen. Durch Bewegen der Mikroreaktoren k{\"o}nnen diese {\"u}ber immobilisierten Enzymen positioniert werden, um so einen enzymatischen Umsatz innerhalb der Mikroreaktoren zu realisieren. Hierf{\"u}r wurde eine neue Mikroreaktorplattform-Technologie etabliert. Die Mikroreaktoren k{\"o}nnen aufgrund ihrer magnetisierbaren H{\"u}llenpartikel {\"u}ber elektromagnetische Spulen bewegt werden. Die Bewegung erfolgt dabei mit einer automatisierten Aktuatorplattform, bestehend aus einer 3x3 Doppelspulenmatrix mit Magnetkernen. Als modellhaftes Reaktionssystem wird eine Enzymkaskade eingesetzt, die sich aus einer b-Glucosidase, Glucose-Oxidase und Meerrettichperoxidase zusammensetzt. Prim{\"a}r untersuchte Substrate sind Fluorescein-di-b-D-glucopyranoside, und 1-(3,7-Dihydroxy-10H-phenoxazin-10-yl)-ethanon, bei deren Umsatz fluoreszierende Produkte entstehen.}, language = {de} } @misc{RothTippkoetter2016, author = {Roth, J. and Tippk{\"o}tter, Nils}, title = {New Approach for Enzymatic Hydrolysis of Lignocellulose with Selective Diffusion Separation of the Monosaccharide Products}, series = {Chemie Ingenieur Technik}, volume = {88}, journal = {Chemie Ingenieur Technik}, number = {9}, publisher = {Wiley-VCH}, address = {Weinheim}, issn = {0009-286X}, doi = {10.1002/cite.201650301}, pages = {1237}, year = {2016}, abstract = {Enzymatic hydrolysis of lignocellulosic material plays an important role in the classical biorefinery approach. Apart from the pretreatment of the raw material, hydrolysis is the basis for the conversion of the cellulose and hemicellulose fraction into fermentable sugars. After hydrolysis, usually a solid-liquid separation takes place, in order to separate the residual plant material from the sugar-rich fraction, which can be subsequently used in a fermentation step. In order to factor out the separation step, the usage of in alginate immobilized crude cellulose fiber beads (CFBs) were evaluated. Pretreated cellulose fibers are incorporated in an alginate matrix together with the relevant enzymes. In doing so, sugars diffuse trough the alginate matrix, allowing a simplified delivery into the surrounding fluid. This again reduces product inhibition of the glucose on the enzyme catalysts. By means of standardized bead production the hydrolysis in lab scale was possible. First results show that liberation of glucose and xylose is possible, allowing a maximum total sugar yield of 75 \%.}, language = {en} } @misc{HeringUlberTippkoetter2016, author = {Hering, T. and Ulber, Roland and Tippk{\"o}tter, Nils}, title = {Antimikrobielle Oberfl{\"a}chenmodifikation durch Mikropartikel}, series = {Chemie Ingenieur Technik}, volume = {88}, journal = {Chemie Ingenieur Technik}, number = {9}, publisher = {Wiley-VCH}, address = {Weinheim}, doi = {10.1002/cite.201650084}, pages = {1302}, year = {2016}, abstract = {Die Ausbildung von Biofilmen in technischen Anlagen, wie z. B. K{\"u}hlkreisl{\"a}ufen, Wasseraufbereitungssystemen und Bioreaktoren, f{\"u}hren zu Materialsch{\"a}den (Biofouling) und stark erh{\"o}htem Energieaufwand. Im Rahmen der aktuellen Forschungsarbeiten erfolgen aktive sowie passive Bio-Modifikationen auf funktionalisierten magnetischen Mikropartikelober-fl{\"a}chen. Um die verschiedenen funktionalisierten magnetischen Mikropartikel zu analysieren und ihre antimikrobielle Wirkung zu testen, wird der Einsatz einer 3D-gedruckten, magnetischen Plattform f{\"u}r ein Fluoreszenz-basiertes Screening-System untersucht. F{\"u}r den Oberfl{\"a}chenschutz wurden verschiedene, antimikrobiell funktionalisierte Partikelkombinationen mit dem Mikroorganismus Escherichia coli GFPmut2 in Bezug auf aktiven Oberfl{\"a}chenschutz verglichen. Um die antimikrobielle Oberfl{\"a}cheneffekte von synergistischen Kombinationen unterschiedlich funktionalisierter Partikel zu bestimmen, werden Oberfl{\"a}chen einem Magnetfeld ausgesetzt, das die Mikropartikel als definierte Schicht auf ihnen zur{\"u}ck h{\"a}lt. Diese modifizierten Oberfl{\"a}chen k{\"o}nnen sowohl durch Fluoreszenzspektroskopie als auch -mikroskopie analysiert werden.}, language = {de} } @misc{WulfhorstMerseburgTippkoetter2016, author = {Wulfhorst, H. and Merseburg, J. and Tippk{\"o}tter, Nils}, title = {Batteriekomponenten aus nachwachsenden Rohstoffen}, series = {Chemie Ingenieur Technik}, volume = {88}, journal = {Chemie Ingenieur Technik}, number = {9}, publisher = {Wiley-VCH}, address = {Weinheim}, issn = {0009-286X}, doi = {10.1002/cite.201650333}, pages = {1234 -- 1235}, year = {2016}, abstract = {In diesem Beitrag geht es um die Integration von Stoffstr{\"o}men einer Lignocellulose-Bioraffinerie in Verfahren zur Batterieherstellung. Pflanzliche Reststoffe aus der Biokraftstoffherstellung wie Lignin sollen zur Herstellung neuer Batteriematerialien verwendet werden. Hierbei wird das Lignin als Matrix f{\"u}r die vorgraphitischen C-haltigen Einlagerungsverbindungen in den Elektroden genutzt. Die Si-C-Komposite werden durch das Einbetten von Si in eine Ligninmatrix mit anschließender Carbonisierung hergestellt. Das Lignin hierf{\"u}r wird durch die sequentielle hydrothermale Vorbehandlung von Buchenholz bei variablen Bedingungen gewonnen und mit Si-Nanopartikel sowie als Referenz ohne Si-Nanopartikel gef{\"a}llt. Die Ergebnisse zeigen, dass die sequenzielle Vorbehandlung h{\"o}here Ausbeuten im Vergleich zum LHW- oder Organosolv-Aufschluss liefert. Um eine Anode herzustellen, wurde das resultierende Si-C-Kompositmaterial carbonisiert, auf einen Stromsammler aufgetragen und elektro-chemisch charakterisiert. Der Einfluss der Vorbehandlungsschritte auf den Herstellungsprozess und die {\"o}konomische Bewertung des untersuchten Bioraffinerie-Prozesses wurde mithilfe eines Stoffstrommodells analysiert.}, language = {de} } @article{AyalaHarrisKleefeld2024, author = {Ayala, Rafael Ceja and Harris, Isaac and Kleefeld, Andreas}, title = {Direct sampling method via Landweber iteration for an absorbing scatterer with a conductive boundary}, series = {Inverse Problems and Imaging}, volume = {18}, journal = {Inverse Problems and Imaging}, number = {3}, publisher = {AIMS}, address = {Springfield}, issn = {1930-8337}, doi = {10.3934/ipi.2023051}, pages = {708 -- 729}, year = {2024}, abstract = {In this paper, we consider the inverse shape problem of recovering isotropic scatterers with a conductive boundary condition. Here, we assume that the measured far-field data is known at a fixed wave number. Motivated by recent work, we study a new direct sampling indicator based on the Landweber iteration and the factorization method. Therefore, we prove the connection between these reconstruction methods. The method studied here falls under the category of qualitative reconstruction methods where an imaging function is used to recover the absorbing scatterer. We prove stability of our new imaging function as well as derive a discrepancy principle for recovering the regularization parameter. The theoretical results are verified with numerical examples to show how the reconstruction performs by the new Landweber direct sampling method.}, language = {en} }