@masterthesis{Lauber2022, type = {Bachelor Thesis}, author = {Lauber, Nico}, title = {Kinetische Piktogramme als Visualisierung : animierte Piktogramme als Kommunikationsmittel im kulturellen Raum}, publisher = {FH Aachen}, address = {Aachen}, school = {Fachhochschule Aachen}, pages = {65 Seiten}, year = {2022}, abstract = {In dieser Arbeit wurden kinetische Piktogramme als Kommunikationsmittel f{\"u}r das Stadttheater Aachen erstellt. Diese sollen als Erweiterung des bestehenden Corporate Designs ein j{\"u}ngeres Publikum zu der bestehenden Zuschauerschaft hinzugewinnen. Die Piktogramme sind dabei inhaltlich an verschiedene Auff{\"u}hrungen des Theaters angepasst und unterst{\"u}tzen die Typografie in animierten Plakaten f{\"u}r die Außenwerbung. Die Umsetzung der kinetischen Piktogramme wurde als Variable Font vollzogen. Damit l{\"a}sst sich der Schriftschnitt durch verschiedene Interpolation-Achsen nach Belieben manipulieren. Dazu werden die Zwischenschritte automatisch errechnet, was die Technik optimal f{\"u}r eine 2D-Animation macht. Anhand konkreter Anwendungsbeispiele zeigt diese Arbeit die vielen Vorteile von Variable Fonts und wirft damit einen Blick in das weite Feld ihrer spannenden M{\"o}glichkeiten, die bis dato l{\"a}ngst noch nicht voll ausgesch{\"o}pft wurden.}, language = {de} } @masterthesis{Jesse2022, type = {Bachelor Thesis}, author = {Jesse, Judith}, title = {Coming to Equal Sex : eine Aufkl{\"a}rungskampagne zur Orgasmusl{\"u}cke}, publisher = {FH Aachen}, address = {Aachen}, school = {Fachhochschule Aachen}, pages = {71 Seiten}, year = {2022}, abstract = {Die „Orgasmusl{\"u}cke" ist ein Begriff aus der Sexualforschung, der die Ungleichheit von Orgasmen zwischen den verschiedenen Geschlechtern und Sexualit{\"a}ten beschreibt. Sie beruht dabei vor allem auf das problematische Verst{\"a}ndnis von Sex, das durch verschiedene kulturelle Einfl{\"u}sse vermittelt wird. Um {\"u}ber diese Einfl{\"u}sse aufzukl{\"a}ren, wurde das Format „fuckfulness" konzipiert. Mithilfe von animierten Videos und darauf aufbauendem Social-Media-Content befasst sich „fuckfulness" ausf{\"u}hrlich mit allen Hintergr{\"u}nden der Orgasmusl{\"u}cke und gestaltet sexuelle Aufkl{\"a}rung neu. Durch junge und moderne Kommunikation wird das Projekt auch f{\"u}r eine j{\"u}ngere Zielgruppe unterhaltsam. Ziel ist ein neues Verst{\"a}ndnis von Sex, in dem die Bed{\"u}rfnisse der Frau gleichberechtigt neben denen des Mannes stehen und entsprechende Beachtung finden. So soll die Orgasmusl{\"u}cke schmaler werden, damit die Gleichstellung endlich auch in den eigenen vier W{\"a}nden gelebt werden kann.}, language = {de} } @masterthesis{Herzog2022, type = {Bachelor Thesis}, author = {Herzog, Nathalie}, title = {Willkommen, heimische Wildtiere! : eine Kampagne zum Thema Artenschutz}, publisher = {FH Aachen}, address = {Aachen}, school = {Fachhochschule Aachen}, pages = {81 Seiten}, year = {2022}, abstract = {Tierpatenschaften bilden einen notwendigen Bestandteil, um Gelder f{\"u}r den Artenschutz zu akquirieren und sowohl in Tierschutzprojekte als auch in die Erhaltung der Lebensr{\"a}ume zu investieren. Doch um weiterhin Pat:Innen zu gewinnen und die Spendenbereitschaft zu steigern, m{\"u}ssen Patenschaften pers{\"o}nlicher werden. Daf{\"u}r schafft dieses Projekt eine neue Form der Patenschaft, die in einer vorwiegend digitalen Kampagne beworben wird. Mithilfe von Kooperationen {\"u}ber Instagram gewinnt das Thema an Reichweite. Unter dem Motto "ganz nah dran" {\"u}berwindet die Kampagne die physische Distanz zwischen Wildtier und Pat:In durch virtuelle Erlebnisse und schafft somit eine emotionale Verbindung. Dadurch steigt nicht die Spendenbereitschaft f{\"u}r das Patentier an sich, sondern ihm zuliebe eben auch f{\"u}r den Schutz des Lebensraums. Damit {\"o}ffnet dieses Konzept den Blick f{\"u}r unkonventionelle L{\"o}sungen zum Erhalt der Wildtiere in Deutschland.}, language = {de} } @masterthesis{Hambloch2022, type = {Bachelor Thesis}, author = {Hambloch, Antonia}, title = {Wie ein Stier im Porzellanladen}, publisher = {FH Aachen}, address = {Aachen}, pages = {35 Seiten}, year = {2022}, abstract = {Menschliche Kommunikation ist gepr{\"a}gt von Sprichw{\"o}rtern und Redewendungen. Von Generation zu Generation weitergegeben, spiegeln sie Lebenserfahrungen, Traditionen und Moralvorstellungen wider, die sich im Laufe der Zeit im allgemeinen Sprachgebrauch etabliert haben. Redensarten werden von Menschen auf der ganzen Welt verwendet. H{\"a}ufig stammen diese bildhaften Vergleiche aus dem Tierreich, was auf die lange gemeinsame Vergangenheit von Tier und Mensch zur{\"u}ckzuf{\"u}hren ist. Bis heute spielen Tiere eine besondere Rolle im Alltag vieler Menschen. Die Ausdr{\"u}cke, die in dem Sachbuch „Wie ein Stier im Porzellanladen" illustrativ und textlich veranschaulicht werden, sind Redensarten {\"u}ber Tiere aus verschiedenen Zeiten, Sprachen und L{\"a}ndern. Manche werden Lesenden bekannt vorkommen, andere {\"o}ffnen den Blick f{\"u}r neue Ausdrucksweisen. Sie am{\"u}sieren in ihrer faszinierenden Vielfalt durch erfrischenden Humor. Das Buch offenbart auf unterhaltsame Weise, wie {\"a}hnlich die Gedanken der Menschen, die sich in spannenden Analogien zwischen Sprachen und Kulturen widerspiegeln, bei n{\"a}herer Betrachtung eigentlich sind.}, language = {de} } @masterthesis{Guth2022, type = {Bachelor Thesis}, author = {Guth, Katharina}, title = {aco : eine digitale Anwendung zur Verbesserung der Lebensqualit{\"a}t von Neurodermitis-Patient:innen}, publisher = {FH Aachen}, address = {Aachen}, school = {Fachhochschule Aachen}, pages = {267 Seiten}, year = {2022}, abstract = {Neurodermitis hat in den letzten Jahrzehnten deutlich zugenommen. Etwa 10 bis 15 Prozent der Kinder und 2,5 bis 3,5 Prozent der Erwachsenen sind davon betroffen. F{\"u}r sie stellen Auswirkungen der Hautkrankheit auf K{\"o}rper und Psyche eine enorme Einschr{\"a}nkung der Lebensqualit{\"a}t dar. Die App „aco" m{\"o}chte Neurodermitis-Patient:Innen dabei unterst{\"u}tzen, ihre Behandlung selbst in die Hand zu nehmen. Eine ganzheitliche Therapie umfasst eben nicht nur Fachpersonen, sondern auch Patient:Innen selbst. Durch eine regelm{\"a}ßige Dokumentation erm{\"o}glicht die Anwendung eine aktive Auseinandersetzung mit der Krankheit. Triggerfaktoren werden ausgewertet und es wird Wissen {\"u}ber Behandlungsm{\"o}glichkeiten vermittelt. Zudem wird ein Austausch erm{\"o}glicht, der emotionale und praktische Unterst{\"u}tzung bieten soll. Damit m{\"o}chte „aco" Betroffenen eine M{\"o}glichkeit geben, das Ruder selbst in die Hand zu nehmen und leistet damit einen wichtigen Beitrag zur Therapie von Neurodermitis.}, language = {de} } @masterthesis{Frank2022, type = {Bachelor Thesis}, author = {Frank, Jemima Leonie}, title = {Falling in love with the female gaze}, publisher = {FH Aachen}, address = {Aachen}, school = {Fachhochschule Aachen}, pages = {81 Seiten}, year = {2022}, abstract = {Der „Male Gaze" bezeichnet das typische Erleben der Umwelt aus m{\"a}nnlicher Perspektive und pr{\"a}gt in den sogenannten Mainstream-Medien die Gestaltung von Film, Fernsehen und Werbung. Dadurch werden von dargestellten Personen h{\"a}ufig die k{\"o}rperlichen Aspekte hervorgehoben. Im Gegensatz dazu gilt das weibliche Pendant, der „Female Gaze", als besonders emotionsbetont. Weil Medien einen enormen Einfluss auf gesellschaftliches und individuelles Denken haben, stellt die Dominanz des „Male Gaze" eine Unausgeglichenheit dar, die sich in verschiedenen Bereichen des gesellschaftlichen Lebens widerspiegelt. Deswegen m{\"o}chte dieses Projekt die Medien um die weibliche Sichtweise erweitern und damit die dort transportierten Bilder diverser und ausgewogener machen. Die Fotografie fokussiert sich dabei auf die Gef{\"u}hlswelt der Protagonistin, womit die Betrachter:Innen schrittweise in ihre Position hineinversetzt werden sollen. Mit Augen des Mitgef{\"u}hls und eigenem Sch{\"o}nheitsbegriff l{\"a}sst „Falling in love with the female gaze" endlich auch die Frau zu Wort kommen.}, language = {de} } @masterthesis{Ebert2022, type = {Bachelor Thesis}, author = {Ebert, Julia}, title = {Die unsichtbare Gefahr : Mikroplastik}, publisher = {FH Aachen}, address = {Aachen}, school = {Fachhochschule Aachen}, pages = {23 Seiten}, year = {2022}, abstract = {Bereits ein einziger pr{\"u}fender Blick in einen klassischen Privathaushalt vermittelt einen ersten Eindruck davon, wie allgegenw{\"a}rtig Kunststoff im menschlichen Leben ist. H{\"a}ufig {\"u}bersehen wird dabei Mikroplastik, welches im Verh{\"a}ltnis zu seinen gravierenden Auswirkungen auf Mensch und Umwelt in der {\"o}ffentlichen Diskussion bislang noch wenig Beachtung findet. Das f{\"u}hrt dazu, dass die Problematik durch unaufgekl{\"a}rten Konsum weiter angefacht wird. Die Gestaltung des visuellen Magazins m{\"o}chte {\"u}ber die Konsequenzen von Mikroplastik aufkl{\"a}ren und das Bewusstsein {\"u}ber das pers{\"o}nliche Konsumverhalten sch{\"a}rfen. Mithilfe kurzer Infotexte wird die Problematik aus der wissenschaftlichen Perspektive der Umweltorganisationen beleuchtet und durch ausgew{\"a}hlte Mikroskop-Aufnahmen illustriert. Hiermit werden unsichtbare Krisentreiber endlich sichtbar gemacht.}, language = {de} } @masterthesis{Eberhardt2022, type = {Bachelor Thesis}, author = {Eberhardt, Dag Norman}, title = {"I Was Here!"}, publisher = {FH Aachen}, address = {Aachen}, pages = {77 Seiten}, year = {2022}, abstract = {Die Menschheit erlebt aktuell Zeiten drastischen Wandels. Deswegen k{\"o}nnte es wohltun, einen Blick in die Vergangenheit zu werfen und sich darauf zu besinnen, wo die Menschen herkommen, wer sie waren und was seitdem bereits erreicht wurde. In dieser Grafiknovelle wird ein kleiner Steinzeitjunge namens Muami begleitet, der vor 35.000 Jahren die Verg{\"a}nglichkeit des Lebens kennenlernt. Im Verlauf des folgenden Jahres erfindet er die Selbstverewigung in der H{\"o}hlenmalerei. Mit seiner Figur soll aufgezeigt werden, dass die fr{\"u}hen Europ{\"a}er eben keine primitiven Halbaffen, sondern intelligente und außerdem zutiefst kreative Menschen waren. Trotz ihrer rauen Umwelt waren ihre Sorgen und Freuden den unseren gar nicht so un{\"a}hnlich. „I Was Here!" ist ein Versuch, ein authentisches Portr{\"a}t jener Menschen zu schaffen und dabei ihrer Welt, ihrem Leben und ihrer Kunst gerecht zu werden.}, language = {de} } @masterthesis{Dereli2022, type = {Bachelor Thesis}, author = {Dereli, Aziz}, title = {[NON]HUMAN}, publisher = {FH Aachen}, address = {Aachen}, pages = {50 Seiten}, year = {2022}, abstract = {"[NON]HUMAN" ist ein 3D-animierter Kurzfilm, der in einer Zombieapokalypse spielt und sich mit dem Thema der Menschlichkeit befasst. Welche Taten k{\"o}nnen gerechtfertigt werden und welche nicht? Die Handlungsm{\"o}glichkeiten der Menschen im Zuge des Ausbruchs eines neuen Virus werfen viele moralische Fragen auf, mit denen zwischen den Zeilen gerungen wird. Denn in diesem Film bestimmen sie Leben und Tod. Das Ziel dieser Arbeit war es, eine simple Geschichte spannend zu erz{\"a}hlen, indem das Publikum durch eindrucksstarke Bilder gefesselt wird. Dabei er{\"o}ffnen 3D-Animationen neue M{\"o}glichkeiten, die insbesondere in den Aufnahmen der zerst{\"o}rten Stadt zur Geltung kommen. Diese Arbeit zeigt spielerisch, wie sich mit etwas technischem Know-How auch ohne großem Budget hochwertige Filme drehen l{\"a}sst, indem man das Potential smart aussch{\"o}pft.}, language = {de} } @masterthesis{Cakir2022, type = {Bachelor Thesis}, author = {Cakir, Asena}, title = {Goldregen : ein Kurzfilm {\"u}ber Traumabew{\"a}ltigung in einer Therapie}, publisher = {FH Aachen}, address = {Aachen}, school = {Fachhochschule Aachen}, pages = {59 Seiten}, year = {2022}, abstract = {Der „Goldregen" besch{\"a}ftigt sich damit, wie Ereignisse der Kindheit nachhaltig das Erwachsenenleben beeinflussen k{\"o}nnen. Erik ist skeptisch, als er wegen k{\"o}rperlichen Beschwerden zum Psychotherapeuten geschickt wird. Zun{\"a}chst weigert sich, die Therapie {\"u}berhaupt ernst zu nehmen. Doch im Laufe der Sitzungen erf{\"a}hrt er immer mehr {\"u}ber sich selbst. Schlussendlich kommen Erinnerungen an verdr{\"a}ngte Kindheitstraumata hoch, und Erik erkennt den Zusammenhang zu seinem gegenw{\"a}rtigen Leiden. Der Anspruch an den Film war, durch gezielte Gestaltung Dynamik und Spannung in einem dialoggetragenen Kammerspiel zu vermitteln. Bildsprache und Musik wurden dazu gezielt auf den Film abgestimmt, um die Handlung bestm{\"o}glich zu unterst{\"u}tzen. „Goldregen" soll die Zuschauer:Innen zum Nachdenken und Diskutieren anregen, um verbreitete Ber{\"u}hrungs{\"a}ngste zum Thema der mentalen Gesundheit abzubauen und Vorbehalte zur Wirksamkeit einer Therapie auf den Pr{\"u}fstand zu stellen.}, language = {de} } @masterthesis{Bauer2022, type = {Bachelor Thesis}, author = {Bauer, Eva}, title = {Music of the Spheres : der Klang der Planeten}, publisher = {FH Aachen}, address = {Aachen}, pages = {59 Seiten}, year = {2022}, abstract = {"Die Bachelorarbeit "Music of the Spheres" soll wissenschaftliche und k{\"u}nstlerische Elemente zum Thema "Klang der Planeten" in Form einer popul{\"a}rwissenschaftlichen Publikation versammeln. Seit Beginn der Menschheit fasziniert uns der Blick in den n{\"a}chtlichen Sternenhimmel. Einher geht die Sehnsucht des Unbekannten, die unsere Fantasie befl{\"u}gelt. Als auf die Erde gebundenen Lebewesens treibt uns der Drang, mehr {\"u}ber das Universum da draußen herauszufinden. Dieses Spannungsfeld zwischen Wissensdrang und Fantasie ist eine interessante Grundlage f{\"u}r die geplante Bachelorarbeit. In der Bachelorarbeit sollen unsere Emotionen mit wissenschaftlichen Erkenntnissen verbunden werden. F{\"u}r das menschliche Ohr ist die Klangwelt des Weltalls, verursacht durch die sich bewegenden Planeten, ohne Hilfsmittel nicht h{\"o}rbar. Nach unseren bekannten physikalischen Erkenntnissen ist es im Weltraum komplett still, aufgrund des im All vorherrschenden Vakuums. Der Schall kann sich nicht wie auf der Erde {\"u}ber Schallwellen ausbreiten. In der Publikation soll der Klang der Planeten beschrieben bzw. dargestellt werden. Die wissenschaftshistorische Dimension soll aufgezeigt werden. So hat man sich zum Beispiel in der Antike musikalische und lyrische Bilder davon gemacht, wie sich der Klang des Weltalls und der Planeten anh{\"o}ren k{\"o}nnte. Weiterhin faszinierte diese Frage K{\"u}nstler unterschiedlicher Epochen und Stilrichtungen, und ist bis heute ein Thema das Anlaß zu k{\"u}nstlerischem Schaffen gibt. In Form einer Printpublikation soll die Bachelorarbeit historische Thesen und aktuelle wissenschaftliche Texte, Forschungsberichte und Klangdokumente zusammenbringen, literarische und musikalische Umsetzungen zum Thema aufzeigen, und mit wissenschaftlichem und k{\"u}nstlerisch-interpretativem Bildmaterial vereinen. Um das Thema visuell zu veranschaulichen, sollen die Texte durch Bilder und Siebdrucke erg{\"a}nzt werden. Selbst erstellte Siebdruck Experimente k{\"o}nnten mit- und ineinander verkn{\"u}pft werden. Die Publikation weißt ein durchgehendes Gestaltungskonzept auf, welches Texte, Illustrationen und Bildmaterial als Einheit verkn{\"u}pfen und wiedererkennbar machen. Ebenfalls ist die Auswahl der verwendeten Materialien und Verarbeitungstechniken, wie Druck, Bindung und Papier zu beachten. Neben dem Text- und Bildmaterial werden Klang-Beispiele eingebunden durch QR Codes. So kann der Leser den QR Code der Siebdrucke scannen, um den von der US-Weltraumorganisation NASA erstellten Klang des Planeten anzuh{\"o}ren. Oder ausgehend von wissenschaftlichem Bildmaterial kann der Leser per Scan eine musikalische Partition zum entsprechenden Planeten anh{\"o}ren. Die angestrebte Zielgruppe besteht aus Wissenschafts- und Designaffinen Personen, die sich insbesondere f{\"u}r den Weltraum interessieren. Entsprechend soll die Gestaltung informativ und gleichzeitig zeitgen{\"o}ssisch sein, um Aufmerksamkeit zu erregen. Mit dem Inhalt der Publikation soll dem Leser gleichzeitig auch der Klang der Planeten h{\"o}rbar zug{\"a}nglich gemacht werden.}, language = {de} } @masterthesis{AsmuthDeStefano2022, type = {Bachelor Thesis}, author = {Asmuth, Mara and De Stefano, Miriam}, title = {GummiQs Reisen}, publisher = {FH Aachen}, address = {Aachen}, school = {Fachhochschule Aachen}, pages = {71 Seiten}, year = {2022}, abstract = {Dieser Film ist ein Trailer zur Mini-Serie GummiQs Reisen, welche von den fantastischen Abenteuern der Entdeckerinnen GummiQ und Kreska Kr{\"a}henschreck erz{\"a}hlt. Gemeinsam erkunden sie auf ihrem Kahn, der Kaleidoskop?, eine lebensfrohe Ozeanwelt, die mit winzigen, einzigartigen Inseln gespickt ist. Im Gegensatz zur jungen GummiQ, die zum ersten Mal verreist, ist Kreska schon eine erfahrene Seefahrerin und wird GummiQs Kapitänin und Mentorin. Sie leitet GummiQ nicht nur durch das Meer, sondern auch durch philosophische Gefilde. Denn jede Insel birgt ein eigenes soziales Dilemma, welches das ungew{\"o}hnliche Paar immer wieder dazu herausfordert, die Welt zu hinterfragen, von der sie glaubten, sie zu kennen. Gesprochen von Marianne Graffam. Musik von Eric Michels. Geschrieben und produziert von Miriam De Stefano und Mara Asmuth.}, language = {de} } @phdthesis{DahmenBeumers2005, author = {Dahmen-Beumers, Judith}, title = {Eine exemplarische Untersuchung zur Regionalit{\"a}t in der Kunst : der Aachener Bildhauer und Maler Benno Werth (*1929)}, publisher = {Books on Demand}, address = {Norderstedt}, isbn = {3-8334-3014-1}, pages = {IV, 297 Seiten}, year = {2005}, language = {de} } @article{KaulenSchwabedalSchneideretal.2022, author = {Kaulen, Lars and Schwabedal, Justus T. C. and Schneider, Jules and Ritter, Philipp and Bialonski, Stephan}, title = {Advanced sleep spindle identification with neural networks}, series = {Scientific Reports}, volume = {12}, journal = {Scientific Reports}, number = {Article number: 7686}, publisher = {Springer Nature}, address = {London}, issn = {2045-2322}, doi = {10.1038/s41598-022-11210-y}, pages = {1 -- 10}, year = {2022}, abstract = {Sleep spindles are neurophysiological phenomena that appear to be linked to memory formation and other functions of the central nervous system, and that can be observed in electroencephalographic recordings (EEG) during sleep. Manually identified spindle annotations in EEG recordings suffer from substantial intra- and inter-rater variability, even if raters have been highly trained, which reduces the reliability of spindle measures as a research and diagnostic tool. The Massive Online Data Annotation (MODA) project has recently addressed this problem by forming a consensus from multiple such rating experts, thus providing a corpus of spindle annotations of enhanced quality. Based on this dataset, we present a U-Net-type deep neural network model to automatically detect sleep spindles. Our model's performance exceeds that of the state-of-the-art detector and of most experts in the MODA dataset. We observed improved detection accuracy in subjects of all ages, including older individuals whose spindles are particularly challenging to detect reliably. Our results underline the potential of automated methods to do repetitive cumbersome tasks with super-human performance.}, language = {en} } @incollection{DiekmannEggert2021, author = {Diekmann, Julian and Eggert, Mathias}, title = {Is a Progressive Web App an Alternative for Native App Development?}, series = {3. Wissenschaftsforum: Digitale Transformation (WiFo21) (Lecture Notes in Informatics ; P-319)}, booktitle = {3. Wissenschaftsforum: Digitale Transformation (WiFo21) (Lecture Notes in Informatics ; P-319)}, publisher = {Gesellschaft f{\"u}r Informatik}, address = {Darmstadt}, isbn = {978-3-88579-713-5}, pages = {35 -- 48}, year = {2021}, abstract = {The existence of several mobile operating systems, such as Android and iOS, is a challenge for developers because the individual platforms are not compatible with each other and require separate app developments. For this reason, cross-platform approaches have become popular but lack in cloning the native behavior of the different operating systems. Out of the plenty cross-platform approaches, the progressive web app (PWA) approach is perceived as promising but needs further investigation. Therefore, the paper at hand aims at investigating whether PWAs are a suitable alternative for native apps by developing a PWA clone of an existing app. Two surveys are conducted in which potential users test and evaluate the PWA prototype with regard to its usability. The survey results indicate that PWAs have great potential, but cannot be treated as a general alternative to native apps. For guiding developers when and how to use PWAs, four design guidelines for the development of PWA-based apps are derived based on the results.}, language = {en} } @inproceedings{Dachwald2017, author = {Dachwald, Bernd}, title = {Radiation pressure force model for an ideal laser-enhanced solar sail}, series = {4th International Symposium on Solar Sailing}, booktitle = {4th International Symposium on Solar Sailing}, pages = {1 -- 5}, year = {2017}, abstract = {The concept of a laser-enhanced solar sail is introduced and the radiation pressure force model for an ideal laser-enhanced solar sail is derived. A laser-enhanced solar sail is a "traditional" solar sail that is, however, not solely propelled by solar radiation, but additionally by a laser beam that illuminates the sail. The additional laser radiation pressure increases the sail's propulsive force and can give, depending on the location of the laser source, more control authority over the direction of the solar sail's propulsive force vector. This way, laser-enhanced solar sails may augment already existing solar sail mission concepts and make novel mission concepts feasible.}, language = {en} } @inproceedings{SeefeldtBauerDachwaldetal.2015, author = {Seefeldt, Patric and Bauer, Waldemar and Dachwald, Bernd and Grundmann, Jan Thimo and Straubel, Marco and Sznajder, Maciej and T{\´o}th, Norbert and Zander, Martin E.}, title = {Large lightweight deployable structures for planetary defence: solar sail propulsion, solar concentrator payloads, large-scale photovoltaic power}, series = {4th IAA Planetary Defense Conference - PDC 2015, 13-17 April 2015, Frascati, Roma, Italy}, booktitle = {4th IAA Planetary Defense Conference - PDC 2015, 13-17 April 2015, Frascati, Roma, Italy}, pages = {24}, year = {2015}, language = {en} } @masterthesis{Schnitzler2022, type = {Bachelor Thesis}, author = {Schnitzler, Nora}, title = {Identifikation und Bewertung geeigneter Mikrostrukturierungen zum Schutz von Biohybridbeschichtungen von Zahnimplantaten vor Abrasion beim Z{\"a}hneputzen}, publisher = {FH Aachen}, address = {Aachen}, school = {Fachhochschule Aachen}, pages = {67 S.}, year = {2022}, abstract = {Die Oberfl{\"a}chen dentaler Implantate sind definiert durch eine raue Oberfl{\"a}che, um die Integration in den menschlichen Knochen zu optimieren. Entz{\"u}ndungen des umgebenden Zahnfleisches z{\"a}hlen dabei zu den h{\"a}ufigsten Komplikationen nach einer Implantation. Diese Entz{\"u}ndungen entstehen haupts{\"a}chlich durch bakterielle Infektionen des Weichgewebes an der Implantations-Stelle. Die raue Oberfl{\"a}che tr{\"a}gt jedoch zu einer solchen Infektion bei. Da der Implantat-Kopf zum Teil aus dem Knochen herausragt, erfolgt beispielsweise beim Z{\"a}hneputzen eine Freilegung der Implantat-Oberfl{\"a}che. Die durch die Rauheit vergr{\"o}ßerte Oberfl{\"a}che bietet dabei ideale Voraussetzungen f{\"u}r eine Bakterienansiedlung. In der aktuellen Forschung steht die Entwicklung einer Oberfl{\"a}che im Vordergrund, die eine antibakterielle Funktionalisierung erzeugt. Diese verhindert die Bakterienansiedlung und wirkt einer Entz{\"u}ndung entgegen. Um die Beschichtung vor Verschleiß zu sch{\"u}tzen und ihre Lebensdauer der antibakteriellen Wirkung zu erh{\"o}hen, ist es m{\"o}glich die Oberfl{\"a}che mit einer Mikrostruktur zu versehen. Das Ziel der vorliegenden Arbeit ist die Identifikation geeigneter Mikrostrukturierungen, die der antibakteriellen Beschichtung einen optimalen Schutz vor Verschleiß bieten. Am Beispiel von Titan-Zahnimplantaten wird der Schutz der aufgetragenen Biohybridbeschichtung gegen abrasiven Verschleiß untersucht. Im Vorfeld wird eine Analyse der fertigungstechnischen M{\"o}glichkeiten mit Blick auf dentale Implantate und Mikrostrukturen durchgef{\"u}hrt, um das ein passendes Verfahren zu identifizieren. Die Analogiebauteile als Probenk{\"o}rper werden, mithilfe des zuvor ausgew{\"a}hlten Verfahrens, mit verschiedenen Mikrostrukturen versehen. Im Rahmen einer Versuchsdurchf{\"u}hrung, die die mechanische Belastung bei einem Zahnputzdurchgang imitiert, werden die verschiedenen Mikrostrukturen auf ihre Eignung f{\"u}r diese Anwendung {\"u}berpr{\"u}ft. Ein Vorversuch dient zur Identifizierung eines geeigneten Ankerpeptids, welches den bindenden Bestandteil der Biohybridbeschichtung darstellt. Aus drei zuvor ausgew{\"a}hlten Ankerpeptiden wird das mit der besten Adh{\"a}sionsf{\"a}higkeit herausgestellt. Im finalen Versuchsdurchlauf wird das Ankerpeptid auf die Oberfl{\"a}chen, die mit den Mikrostrukturen versehen sind, aufgetragen. Dabei ist das Ziel eine Mikrostruktur herauszustellen, die den h{\"o}chstm{\"o}glichen Schutz bietet. Durch eine Fluoreszenzpr{\"u}fung mithilfe eines Flourescence Plate Readers wird jede Kombination nach den Belastungsversuchen auf den Restanteil der Beschichtung {\"u}berpr{\"u}ft. Das Ergebnis stellt eine Mikrostruktur dar, die den bestm{\"o}glichen Schutz bietet. Dies ist erkennbar durch den h{\"o}chsten Anteil an Restbeschichtung. Eine Strukturierung mit sogenannten Micro-Grooves in Kombination mit dem MacHis-Ankerpeptid erzielte in der Analyse der Belastungssimulationen die besten Ergebnisse bez{\"u}glich des Schutzes der Beschichtung. Durch die Versuche best{\"a}tigte sich eine weitere Annahme. Die Strukturierung der Oberfl{\"a}che erzielt einen deutlich h{\"o}heren Schutz im Vergleich zu einer unstrukturierten Oberfl{\"a}che. Zudem hat sich herausgestellt, dass eine Beschichtung mit dem sogenannten PEO-Verfahren eine deutlich gr{\"o}ßere Adh{\"a}sion der Biohybridbeschichtung erzielt. Dies wird jedoch Thema weiterf{\"u}hrender Forschungen sein und kein Bestandteil der vorliegenden Arbeit.}, language = {de} } @inproceedings{SchoutetensDachwaldHeiligers2021, author = {Schoutetens, Frederic and Dachwald, Bernd and Heiligers, Jeannette}, title = {Optimisation of photon-sail trajectories in the alpha-centauri system using evolutionary neurocontrol}, series = {8th ICATT 2021}, booktitle = {8th ICATT 2021}, pages = {1 -- 15}, year = {2021}, abstract = {With the increased interest for interstellar exploration after the discovery of exoplanets and the proposal by Breakthrough Starshot, this paper investigates the optimisation of photon-sail trajectories in Alpha Centauri. The prime objective is to find the optimal steering strategy for a photonic sail to get captured around one of the stars after a minimum-time transfer from Earth. By extending the idea of the Breakthrough Starshot project with a deceleration phase upon arrival, the mission's scientific yield will be increased. As a secondary objective, transfer trajectories between the stars and orbit-raising manoeuvres to explore the habitable zones of the stars are investigated. All trajectories are optimised for minimum time of flight using the trajectory optimisation software InTrance. Depending on the sail technology, interstellar travel times of 77.6-18,790 years can be achieved, which presents an average improvement of 30\% with respect to previous work. Still, significant technological development is required to reach and be captured in the Alpha-Centauri system in less than a century. Therefore, a fly-through mission arguably remains the only option for a first exploratory mission to Alpha Centauri, but the enticing results obtained in this work provide perspective for future long-residence missions to our closest neighbouring star system.}, language = {en} } @article{Dachwald2005, author = {Dachwald, Bernd}, title = {Optimization of very-low-thrust trajectories using evolutionary neurocontrol}, series = {Acta Astronautica}, volume = {57}, journal = {Acta Astronautica}, number = {2-8}, publisher = {Elsevier}, address = {Amsterdam [u.a.]}, isbn = {1879-2030}, pages = {175 -- 185}, year = {2005}, abstract = {Searching optimal interplanetary trajectories for low-thrust spacecraft is usually a difficult and time-consuming task that involves much experience and expert knowledge in astrodynamics and optimal control theory. This is because the convergence behavior of traditional local optimizers, which are based on numerical optimal control methods, depends on an adequate initial guess, which is often hard to find, especially for very-low-thrust trajectories that necessitate many revolutions around the sun. The obtained solutions are typically close to the initial guess that is rarely close to the (unknown) global optimum. Within this paper, trajectory optimization problems are attacked from the perspective of artificial intelligence and machine learning. Inspired by natural archetypes, a smart global method for low-thrust trajectory optimization is proposed that fuses artificial neural networks and evolutionary algorithms into so-called evolutionary neurocontrollers. This novel method runs without an initial guess and does not require the attendance of an expert in astrodynamics and optimal control theory. This paper details how evolutionary neurocontrol works and how it could be implemented. The performance of the method is assessed for three different interplanetary missions with a thrust to mass ratio <0.15mN/kg (solar sail and nuclear electric).}, language = {en} } @inproceedings{DachwaldMengaliQuartaetal.2007, author = {Dachwald, Bernd and Mengali, Giovanni and Quarta, Alessandro A and Macdonald, Malcolm and McInnes, Colin R}, title = {Optical solar sail degradation modelling}, series = {1st International Symposium on Solar Sailing}, booktitle = {1st International Symposium on Solar Sailing}, pages = {1 -- 27}, year = {2007}, abstract = {We propose a simple parametric OSSD model that describes the variation of the sail film's optical coefficients with time, depending on the sail film's environmental history, i.e., the radiation dose. The primary intention of our model is not to describe the exact behavior of specific film-coating combinations in the real space environment, but to provide a more general parametric framework for describing the general optical degradation behavior of solar sails.}, language = {en} } @inproceedings{LoebSchartnerDachwaldetal.2007, author = {Loeb, Horst Wolfgang and Schartner, Karl-Heinz and Dachwald, Bernd and Seboldt, Wolfgang}, title = {SEP-Sample return from a main belt asteroid}, series = {30th International Electric Propulsion Conference}, booktitle = {30th International Electric Propulsion Conference}, pages = {1 -- 11}, year = {2007}, abstract = {By DLR-contact, sample return missions to the large main-belt asteroid "19, Fortuna" have been studied. The mission scenario has been based on three ion thrusters of the RIT-22 model, which is presently under space qualification, and on solar arrays equipped with triple-junction GaAs solar cells. After having designed the spacecraft, the orbit-to-orbit trajectories for both, a one-way SEP mission with a chemical sample return and an all-SEP return mission, have been optimized using a combination of artificial neural networks with evolutionary algorithms. Additionally, body-to-body trajectories have been investigated within a launch period between 2012 and 2015. For orbit-to-orbit calculation, the launch masses of the hybrid mission and of the all-SEP mission resulted in 2.05 tons and 1.56 tons, respectively, including a scientific payload of 246 kg. For the related transfer durations 4.14 yrs and 4.62 yrs were obtained. Finally, a comparison between the mission scenarios based on SEP and on NEP have been carried out favouring clearly SEP.}, language = {en} } @inproceedings{SpurmannOhndorfDachwaldetal.2009, author = {Spurmann, J{\"o}rn and Ohndorf, Andreas and Dachwald, Bernd and Seboldt, Wolfgang and L{\"o}b, Horst and Schartner, Karl-Heinz}, title = {Interplanetary trajectory optimization for a sep mission to Saturn}, series = {60th International Astronautical Congress 2009}, booktitle = {60th International Astronautical Congress 2009}, isbn = {9781615679089}, pages = {5234 -- 5248}, year = {2009}, abstract = {The recently proposed NASA and ESA missions to Saturn and Jupiter pose difficult tasks to mission designers because chemical propulsion scenarios are not capable of transferring heavy spacecraft into the outer solar system without the use of gravity assists. Thus our developed mission scenario based on the joint NASA/ESA Titan Saturn System Mission baselines solar electric propulsion to improve mission flexibility and transfer time. For the calculation of near-globally optimal low-thrust trajectories, we have used a method called Evolutionary Neurocontrol, which is implemented in the low-thrust trajectory optimization software InTrance. The studied solar electric propulsion scenario covers trajectory optimization of the interplanetary transfer including variations of the spacecraft's thrust level, the thrust unit's specific impulse and the solar power generator power level. Additionally developed software extensions enabled trajectory optimization with launcher-provided hyperbolic excess energy, a complex solar power generator model and a variable specific impulse ion engine model. For the investigated mission scenario, Evolutionary Neurocontrol yields good optimization results, which also hold valid for the more elaborate spacecraft models. Compared to Cassini/Huygens, the best found solutions have faster transfer times and a higher mission flexibility in general.}, language = {en} } @inproceedings{SchartnerLoebDachwaldetal.2009, author = {Schartner, Karl-Heinz and Loeb, H. W. and Dachwald, Bernd and Ohndorf, Andreas}, title = {Perspectives of electric propulsion for outer planetary and deep space missions}, series = {European Planetary Science Congress 2009}, booktitle = {European Planetary Science Congress 2009}, pages = {416 -- 416}, year = {2009}, abstract = {Solar-electric propulsion (SEP) is superior with respect to payload capacity, flight time and flexible launch window to the conventional interplanetary transfer method using chemical propulsion combined with gravity assists. This fact results from the large exhaust velocities of electric low-thrust propulsion and is favourable also for missions to the giant planets, Kuiper-belt objects and even for a heliopause probe (IHP) as shown in three studies by the authors funded by DLR. They dealt with a lander for Europa and a sample return mission from a mainbelt asteroid [1], with the TANDEM mission [2]; the third recent one investigates electric propulsion for the transfer to the edge of the solar system. All studies are based on triple-junction solar arrays, on rf-ion thrusters of the qualified RIT-22 type and they use the intelligent trajectory optimization program InTrance [3].}, language = {en} } @article{RichterBraunsteinStaeudleetal.2021, author = {Richter, Charlotte and Braunstein, Bjoern and Staeudle, Benjamin and Attias, Julia and Suess, Alexander and Weber, Tobias and Mileva, Katya N. and Rittweger, Joern and Green, David A. and Albracht, Kirsten}, title = {Contractile behavior of the gastrocnemius medialis muscle during running in simulated hypogravity}, series = {npj Microgravity}, volume = {7}, journal = {npj Microgravity}, number = {Article number: 32}, publisher = {Springer Nature}, address = {New York}, issn = {2373-8065}, doi = {10.1038/s41526-021-00155-7}, pages = {7 Seiten}, year = {2021}, abstract = {Vigorous exercise countermeasures in microgravity can largely attenuate muscular degeneration, albeit the extent of applied loading is key for the extent of muscle wasting. Running on the International Space Station is usually performed with maximum loads of 70\% body weight (0.7 g). However, it has not been investigated how the reduced musculoskeletal loading affects muscle and series elastic element dynamics, and thereby force and power generation. Therefore, this study examined the effects of running on the vertical treadmill facility, a ground-based analog, at simulated 0.7 g on gastrocnemius medialis contractile behavior. The results reveal that fascicle-series elastic element behavior differs between simulated hypogravity and 1 g running. Whilst shorter peak series elastic element lengths at simulated 0.7 g appear to be the result of lower muscular and gravitational forces acting on it, increased fascicle lengths and decreased velocities could not be anticipated, but may inform the development of optimized running training in hypogravity. However, whether the alterations in contractile behavior precipitate musculoskeletal degeneration warrants further study.}, language = {en} } @article{JablonskiPoghossianKeusgenetal.2021, author = {Jablonski, Melanie and Poghossian, Arshak and Keusgen, Michael and Wege, Christina and Sch{\"o}ning, Michael Josef}, title = {Detection of plant virus particles with a capacitive field-effect sensor}, series = {Analytical and Bioanalytical Chemistry}, volume = {413}, journal = {Analytical and Bioanalytical Chemistry}, publisher = {Springer Nature}, address = {Cham}, issn = {1618-2650}, doi = {10.1007/s00216-021-03448-8}, pages = {5669 -- 5678}, year = {2021}, abstract = {Plant viruses are major contributors to crop losses and induce high economic costs worldwide. For reliable, on-site and early detection of plant viral diseases, portable biosensors are of great interest. In this study, a field-effect SiO2-gate electrolyte-insulator-semiconductor (EIS) sensor was utilized for the label-free electrostatic detection of tobacco mosaic virus (TMV) particles as a model plant pathogen. The capacitive EIS sensor has been characterized regarding its TMV sensitivity by means of constant-capacitance method. The EIS sensor was able to detect biotinylated TMV particles from a solution with a TMV concentration as low as 0.025 nM. A good correlation between the registered EIS sensor signal and the density of adsorbed TMV particles assessed from scanning electron microscopy images of the SiO2-gate chip surface was observed. Additionally, the isoelectric point of the biotinylated TMV particles was determined via zeta potential measurements and the influence of ionic strength of the measurement solution on the TMV-modified EIS sensor signal has been studied.}, language = {en} } @inproceedings{BorggraefeDachwald2010, author = {Borggr{\"a}fe, Andreas and Dachwald, Bernd}, title = {Mission performance evaluation for solar sails using a refined SRP force model with variable optical coefficients}, series = {2nd International Symposium on Solar Sailing}, booktitle = {2nd International Symposium on Solar Sailing}, pages = {1 -- 6}, year = {2010}, abstract = {Solar sails provide ignificant advantages over other low-thrust propulsion systems because they produce thrust by the momentum exchange from solar radiation pressure (SRP) and thus do not consume any propellant.The force exerted on a very thin sail foil basically depends on the light incidence angle. Several analytical SRP force models that describe the SRP force acting on the sail have been established since the 1970s. All the widely used models use constant optical force coefficients of the reflecting sail material. In 2006,MENGALI et al. proposed a refined SRP force model that takes into account the dependancy of the force coefficients on the light incident angle,the sail's distance from the sun (and thus the sail emperature) and the surface roughness of the sail material [1]. In this paper, the refined SRP force model is compared to the previous ones in order to identify the potential impact of the new model on the predicted capabilities of solar sails in performing low-cost interplanetary space missions. All force models have been implemented within InTrance, a global low-thrust trajectory optimization software utilizing evolutionary neurocontrol [2]. Two interplanetary rendezvous missions, to Mercury and the near-Earth asteroid 1996FG3, are investigated. Two solar sail performances in terms of characteristic acceleration are examined for both scenarios, 0.2 mm/s2 and 0.5 mm/s2, termed "low" and "medium" sail performance. In case of the refined SRP model, three different values of surface roughness are chosen, h = 0 nm, 10 nm and 25 nm. The results show that the refined SRP force model yields shorter transfer times than the standard model.}, language = {en} } @inproceedings{OhndorfDachwaldSeboldtetal.2011, author = {Ohndorf, Andreas and Dachwald, Bernd and Seboldt, Wolfgang and Schartner, Karl-Heinz}, title = {Flight times to the heliopause using a combination of solar and radioisotope electric propulsion}, series = {32nd International Electric Propulsion Conference}, booktitle = {32nd International Electric Propulsion Conference}, pages = {1 -- 12}, year = {2011}, abstract = {We investigate the interplanetary flight of a low-thrust space probe to the heliopause,located at a distance of about 200 AU from the Sun. Our goal was to reach this distance within the 25 years postulated by ESA for such a mission (which is less ambitious than the 15-year goal set by NASA). Contrary to solar sail concepts and combinations of allistic and electrically propelled flight legs, we have investigated whether the set flight time limit could also be kept with a combination of solar-electric propulsion and a second, RTG-powered upper stage. The used ion engine type was the RIT-22 for the first stage and the RIT-10 for the second stage. Trajectory optimization was carried out with the low-thrust optimization program InTrance, which implements the method of Evolutionary Neurocontrol,using Artificial Neural Networks for spacecraft steering and Evolutionary Algorithms to optimize the Neural Networks' parameter set. Based on a parameter space study, in which the number of thrust units, the unit's specific impulse, and the relative size of the solar power generator were varied, we have chosen one configuration as reference. The transfer time of this reference configuration was 29.6 years and the fastest one, which is technically more challenging, still required 28.3 years. As all flight times of this parameter study were longer than 25 years, we further shortened the transfer time by applying a launcher-provided hyperbolic excess energy up to 49 km2/s2. The resulting minimal flight time for the reference configuration was then 27.8 years. The following, more precise optimization to a launch with the European Ariane 5 ECA rocket reduced the transfer time to 27.5 years. This is the fastest mission design of our study that is flexible enough to allow a launch every year. The inclusion of a fly-by at Jupiter finally resulted in a flight time of 23.8 years,which is below the set transfer-time limit. However, compared to the 27.5-year transfer,this mission design has a significantly reduced launch window and mission flexibility if the escape direction is restricted to the heliosphere's "nose".}, language = {en} } @inproceedings{SchmidtKaschEichleretal.2021, author = {Schmidt, Thomas and Kasch, Susanne and Eichler, Fabian and Thurn, Laura}, title = {Process strategies on laser-based melting of glass powder}, series = {LiM 2021 proceedings}, booktitle = {LiM 2021 proceedings}, pages = {10 Seiten}, year = {2021}, abstract = {This paper presents the laser-based powder bed fusion (L-PBF) using various glass powders (borosilicate and quartz glass). Compared to metals, these require adapted process strategies. First, the glass powders were characterized with regard to their material properties and their processability in the powder bed. This was followed by investigations of the melting behavior of the glass powders with different laser wavelengths (10.6 µm, 1070 nm). In particular, the experimental setup of a CO2 laser was adapted for the processing of glass powder. An experimental setup with integrated coaxial temperature measurement/control and an inductively heatable build platform was created. This allowed the L-PBF process to be carried out at the transformation temperature of the glasses. Furthermore, the component's material quality was analyzed on three-dimensional test specimen with regard to porosity, roughness, density and geometrical accuracy in order to evaluate the developed L-PBF parameters and to open up possible applications.}, language = {en} } @article{LoebSchartnerDachwaldetal.2012, author = {Loeb, Horst Wolfgang and Schartner, Karl-Heinz and Dachwald, Bernd and Ohndorf, Andreas and Seboldt, Wolfgang}, title = {Interstellar heliopause probe}, series = {Труды МАИ}, journal = {Труды МАИ}, number = {60}, publisher = {Moskauer Staatliches Luftfahrtinstitut (МАИ)}, address = {Moskau}, pages = {2 -- 2}, year = {2012}, abstract = {There is common agreement within the scientific community that in order to understand our local galactic environment it will be necessary to send a spacecraft into the region beyond the solar wind termination shock. Considering distances of 200 AU for a new mission, one needs a spacecraft traveling at a speed of close to 10 AU/yr in order to keep the mission duration in the range of less than 25 yrs, a transfer time postulated by European Space Agency (ESA). Two propulsion options for the mission have been proposed and discussed so far: the solar sail propulsion and the ballistic/radioisotope-electric propulsion (REP). As a further alternative, we here investigate a combination of solar-electric propulsion (SEP) and REP. The SEP stage consists of six 22-cms diameter RIT-22 ion thrusters working with a high specific impulse of 7377 s corresponding to a positive grid voltage of 5 kV. Solar power of 53 kW at begin of mission (BOM) is provided by a lightweight solar array.}, language = {en} } @article{WeldenNagamineKomesuWagneretal.2021, author = {Welden, Rene and Nagamine Komesu, Cindy A. and Wagner, Patrick H. and Sch{\"o}ning, Michael Josef and Wagner, Torsten}, title = {Photoelectrochemical enzymatic penicillin biosensor: A proof-of-concept experiment}, series = {Electrochemical Science Advances}, volume = {2}, journal = {Electrochemical Science Advances}, number = {4}, publisher = {Wiley-VCH}, address = {Weinheim}, issn = {2698-5977}, doi = {10.1002/elsa.202100131}, pages = {1 -- 5}, year = {2021}, abstract = {Photoelectrochemical (PEC) biosensors are a rather novel type of biosensors thatutilizelighttoprovideinformationaboutthecompositionofananalyte,enablinglight-controlled multi-analyte measurements. For enzymatic PEC biosensors,amperometric detection principles are already known in the literature. In con-trast, there is only a little information on H+-ion sensitive PEC biosensors. Inthis work, we demonstrate the detection of H+ions emerged by H+-generatingenzymes, exemplarily demonstrated with penicillinase as a model enzyme on atitanium dioxide photoanode. First, we describe the pH sensitivity of the sensorand study possible photoelectrocatalytic reactions with penicillin. Second, weshow the enzymatic PEC detection of penicillin.}, language = {en} } @article{OliveiraMolinnusBegingetal.2021, author = {Oliveira, Danilo A. and Molinnus, Denise and Beging, Stefan and Siqueira Jr, Jos{\´e} R. and Sch{\"o}ning, Michael Josef}, title = {Biosensor Based on Self-Assembled Films of Graphene Oxide and Polyaniline Using a Field-Effect Device Platform}, series = {physica status solidi (a) applications and materials science}, volume = {218}, journal = {physica status solidi (a) applications and materials science}, number = {13}, publisher = {Wiley-VCH}, address = {Weinheim}, issn = {1862-6319}, doi = {10.1002/pssa.202000747}, pages = {1 -- 9}, year = {2021}, abstract = {A new functionalization method to modify capacitive electrolyte-insulator-semiconductor (EIS) structures with nanofilms is presented. Layers of polyallylamine hydrochloride (PAH) and graphene oxide (GO) with the compound polyaniline:poly(2-acrylamido-2-methyl-1-propanesulfonic acid) (PANI:PAAMPSA) are deposited onto a p-Si/SiO2 chip using the layer-by-layer technique (LbL). Two different enzymes (urease and penicillinase) are separately immobilized on top of a five-bilayer stack of the PAH:GO/PANI:PAAMPSA-modified EIS chip, forming a biosensor for detection of urea and penicillin, respectively. Electrochemical characterization is performed by constant capacitance (ConCap) measurements, and the film morphology is characterized by atomic force microscopy (AFM) and scanning electron microscopy (SEM). An increase in the average sensitivity of the modified biosensors (EIS-nanofilm-enzyme) of around 15\% is found in relation to sensors, only carrying the enzyme but without the nanofilm (EIS-enzyme). In this sense, the nanofilm acts as a stable bioreceptor onto the EIS chip improving the output signal in terms of sensitivity and stability.}, language = {en} } @article{MolinnusIkenJohnenetal.2022, author = {Molinnus, Denise and Iken, Heiko and Johnen, Anna Lynn and Richstein, Benjamin and Hellmich, Lena and Poghossian, Arshak and Knoch, Joachim and Sch{\"o}ning, Michael Josef}, title = {Miniaturized pH-Sensitive Field-Effect Capacitors with Ultrathin Ta₂O₅ Films Prepared by Atomic Layer Deposition}, series = {physica status solidi (a) applications and materials science}, volume = {219}, journal = {physica status solidi (a) applications and materials science}, number = {8}, publisher = {Wiley-VCH}, address = {Weinheim}, issn = {1862-6319}, doi = {10.1002/pssa.202100660}, pages = {7 Seiten}, year = {2022}, abstract = {Miniaturized electrolyte-insulator-semiconductor capacitors (EISCAPs) with ultrathin gate insulators have been studied in terms of their pH-sensitive sensor characteristics: three different EISCAP systems consisting of Al-p-Si-Ta2O5(5 nm), Al-p-Si-Si3N4(1 or 2 nm)-Ta2O5 (5 nm), and Al-p-Si-SiO2(3.6 nm)-Ta2O5(5 nm) layer structures are characterized in buffer solution with different pH values by means of capacitance-voltage and constant capacitance method. The SiO2 and Si3N4 gate insulators are deposited by rapid thermal oxidation and rapid thermal nitridation, respectively, whereas the Ta2O5 film is prepared by atomic layer deposition. All EISCAP systems have a clear pH response, favoring the stacked gate insulators SiO2-Ta2O5 when considering the overall sensor characteristics, while the Si3N4(1 nm)-Ta2O5 stack delivers the largest accumulation capacitance (due to the lower equivalent oxide thickness) and a higher steepness in the slope of the capacitance-voltage curve among the studied stacked gate insulator systems.}, language = {en} } @incollection{AkimbekovDigelSherelkhanetal.2022, author = {Akimbekov, Nuraly S. and Digel, Ilya and Sherelkhan, Dinara K. and Razzaque, Mohammed S.}, title = {Vitamin D and Phosphate Interactions in Health and Disease}, series = {Phosphate Metabolism}, booktitle = {Phosphate Metabolism}, publisher = {Springer}, address = {Cham}, isbn = {978-3-030-91621-3}, doi = {10.1007/978-3-030-91623-7_5}, pages = {37 -- 46}, year = {2022}, abstract = {Vitamin D plays an essential role in calcium and inorganic phosphate (Pi) homeostasis, maintaining their optimal levels to assure adequate bone mineralization. Vitamin D, as calcitriol (1,25(OH)2D), not only increases intestinal calcium and phosphate absorption but also facilitates their renal reabsorption, leading to elevated serum calcium and phosphate levels. The interaction of 1,25(OH)2D with its receptor (VDR) increases the efficiency of intestinal absorption of calcium to 30-40\% and phosphate to nearly 80\%. Serum phosphate levels can also influence 1,25 (OH)2D and fibroblast growth factor 23 (FGF23) levels, i.e., higher phosphate concentrations suppress vitamin D activation and stimulate parathyroid hormone (PTH) release, while a high FGF23 serum level leads to reduced vitamin D synthesis. In the vitamin D-deficient state, the intestinal calcium absorption decreases and the secretion of PTH increases, which in turn causes the stimulation of 1,25(OH)2D production, resulting in excessive urinary phosphate loss. Maintenance of phosphate homeostasis is essential as hyperphosphatemia is a risk factor of cardiovascular calcification, chronic kidney diseases (CKD), and premature aging, while hypophosphatemia is usually associated with rickets and osteomalacia. This chapter elaborates on the possible interactions between vitamin D and phosphate in health and disease.}, language = {en} } @article{PfaffEnningSutter2022, author = {Pfaff, Raphael and Enning, Manfred and Sutter, Stefan}, title = {A risk‑based approach to automatic brake tests for rail freight service: incident analysis and realisation concept}, series = {SN Applied Sciences}, volume = {4}, journal = {SN Applied Sciences}, number = {4}, publisher = {Springer}, address = {Cham}, issn = {2523-3971}, doi = {10.1007/s42452-022-05007-x}, pages = {1 -- 14}, year = {2022}, abstract = {This study reviews the practice of brake tests in freight railways, which is time consuming and not suitable to detect certain failure types. Public incident reports are analysed to derive a reasonable brake test hardware and communication architecture, which aims to provide automatic brake tests at lower cost than current solutions. The proposed solutions relies exclusively on brake pipe and brake cylinder pressure sensors, a brake release position switch as well as radio communication via standard protocols. The approach is embedded in the Wagon 4.0 concept, which is a holistic approach to a smart freight wagon. The reduction of manual processes yields a strong incentive due to high savings in manual labour and increased productivity.}, language = {en} } @masterthesis{Thomaschik2021, type = {Bachelor Thesis}, author = {Thomaschik, Annika}, title = {Medical Design for Kids: Integration der Bed{\"u}rfnisse von Kindern in medizinische Produkte}, publisher = {FH Aachen}, address = {Aachen}, school = {Fachhochschule Aachen}, pages = {122 Seiten}, year = {2021}, abstract = {Kinder im Kontext von medizinischen Einrichtungen. Kinder sind keine kleinen Erwachsenen und erfordern einen auf sie angepassten Zugang zu medizinischen Behandlungsabl{\"a}ufen. Das Konzept basiert auf dem Gestaltungsprinzip des „Child Centered Design" mit Befragungen von Experten der P{\"a}diatrie und Forschung sowie mit enger Zusammenarbeit mit Kindern. Entstanden ist ein Produkt welches Skepsis und Angst junger Patienten im Alter von 6 bis 14 Jahren bei station{\"a}ren Aufenthalten in Krankenh{\"a}usern mindert und ihren Heilungsprozess positiv unterst{\"u}tzt. Unter Einbezug von digitalen M{\"o}glichkeiten wie Augmented Reality erkl{\"a}rt „ViU", ein Krankenhaus-Companion in Eulen-Optik, den kleinen Patienten Funktionen und das Wirken verschiedenster medizinischer Ger{\"a}te und Behandlungen. So wird nicht nur der Rate an Traumata durch Krankenhausaufenthalte bei Kindern entgegengewirkt, sondern auch das Krankenhauspersonal im Umgang mit Kindern im Klinikalltag entlastet.}, language = {de} } @masterthesis{Schrey2021, type = {Bachelor Thesis}, author = {Schrey, Leander}, title = {Less Waste Shelf: Ein M{\"o}bel zur Reduzierung der h{\"a}uslich anfallenden Lebensmittelabf{\"a}lle}, publisher = {FH Aachen}, address = {Aachen}, pages = {177 Seiten}, year = {2021}, abstract = {Mit dem Projekt wird sich dem Problem der weltweiten Lebensmittelverschwendung angenommen und versucht Abf{\"a}lle in Privathaushalten prim{\"a}r industrialisierter Staaten zu reduzieren. Mit j{\"a}hrlich 1,3 Milliarden Tonnen landet circa ein Drittel aller weltweit produzierten Lebensmittel im M{\"u}ll. Einen Großteil dieser Abf{\"a}lle ist vermeidbar, besonders dort, wo man im {\"U}berfluss lebt. Das konzipierte M{\"o}belst{\"u}ck soll die Lagerungsm{\"o}glichkeiten des Nutzers optimieren und somit f{\"u}r die Wertsch{\"a}tzung von Lebensmitteln sensibilisieren. F{\"u}r das M{\"o}belst{\"u}ck werden ausschließlich nat{\"u}rliche Materialien verwendet, welche in ihrer Charakteristik optimal zum Funktionsumfang passen, der f{\"u}r die Lagerung ben{\"o}tigt wird. Das Material Terracotta erm{\"o}glicht es, mittels Verdunstungsk{\"u}hlung stromlos Gem{\"u}se kalt zu halten. Antibakterielles Holz t{\"o}tet sch{\"a}dliche Bakterien ab. Die Konstruktion erm{\"o}glicht somit eine fachgerechte Lebensmittelagerung und erm{\"o}glicht sowohl sehr flexible Nutzung, wie auch leichte Reparatur.}, language = {de} } @masterthesis{Niederschmidt2021, type = {Bachelor Thesis}, author = {Niederschmidt, S{\"o}ren}, title = {Living product: ein Ansatz, lebendige Organismen mit einem Produkt zu vereinen und nutzbar zu machen}, publisher = {FH Aachen}, address = {Aachen}, pages = {57 Seiten}, year = {2021}, abstract = {Diese Arbeit setzt sich mit der Frage auseinander, in welcher Form sich lebendige Organismen - hier insbesondere Pilze - in die Produktwelt integrieren lassen. In welcher Art und Weise beeinflusst ein Organismus das Produkterlebnis? Im Rahmen dieser Arbeit sind vier verschiedene Produkte entstanden, die die St{\"a}rken des Materials Myzelium demonstrieren. Myzelium bezeichnet das sehr dichte Wurzelnetzwerk eines Pilzes. Dieses lebendige Netzwerk kann dazu genutzt werden, um organische Stoffe miteinander zu verwachsen und somit Formen entstehen zu lassen. Die so entstandenen Produkte sind in eine Konzeptumgebung eingebettet, in der der Verbrauchende die Natur durch naturn{\"a}here Produkte (Form, Material und gewachsene Strukturen) neu erlebt. Gezeigt wird ein Packaging f{\"u}r Einmachgl{\"a}ser, ein Kressebeet, ein Wandregal und ein Teelicht.}, language = {de} } @inproceedings{DachwaldSeboldtHaeusler2002, author = {Dachwald, Bernd and Seboldt, Wolfgang and H{\"a}usler, Bernd}, title = {Performance requirements for near-term interplanetary solar sailcraft missions}, series = {6th International AAAF Symposium on Space Propulsion: Propulsion for Space Transportation of the XXIst Century}, booktitle = {6th International AAAF Symposium on Space Propulsion: Propulsion for Space Transportation of the XXIst Century}, pages = {9 Seiten}, year = {2002}, abstract = {Solar sailcraft provide a wide range of opportunities for high-energy low-cost missions. To date, most mission studies require a rather demanding performance that will not be realized by solar sailcraft of the first generation. However, even with solar sailcraft of moderate performance, scientifically relevant missions are feasible. This is demonstrated with a Near Earth Asteroid sample return mission and various planetary rendezvous missions.}, language = {en} } @inproceedings{SeboldtDachwald2003, author = {Seboldt, Wolfgang and Dachwald, Bernd}, title = {Solar sails for near-term advanced scientific deep space missions}, series = {Proceedings of the 8th International Workshop on Combustion and Propulsion}, booktitle = {Proceedings of the 8th International Workshop on Combustion and Propulsion}, pages = {14 Seiten}, year = {2003}, abstract = {Solar sails are propelled in space by reflecting solar photons off large mirroring surfaces, thereby transforming the momentum of the photons into a propulsive force. This innovative concept for low-thrust space propulsion works without any propellant and thus provides a wide range of opportunities for highenergy low-cost missions. Offering an efficient way of propulsion, solar sailcraft could close a gap in transportation options for highly demanding exploration missions within our solar system and even beyond. On December 17th, 1999, a significant step was made towards the realization of this technology: a lightweight solar sail structure with an area of 20 m × 20 m was successfully deployed on ground in a large facility at the German Aerospace Center (DLR) at Cologne. The deployment from a package of 60 cm × 60 cm × 65 cm with a total mass of less than 35 kg was achieved using four extremely light-weight carbon fiber reinforced plastics (CFRP) booms with a specific mass of 100 g/m. The paper briefly reviews the basic principles of solar sails as well as the technical concept and its realization in the ground demonstration experiment, performed in close cooperation between DLR and ESA. Next possible steps are outlined. They could comprise the in-orbit demonstration of the sail deployment on the upper stage of a low-cost rocket and the verification of the propulsion concept by an autonomous and free flying solar sail in the frame of a scientific mission. It is expected that the present design could be extended to sail sizes of about (40 m)2 up to even (70 m)2 without significant mass penalty. With these areas, the maximum achievable thrust at 1 AU would range between 10 and 40 mN - comparable to some electric thrusters. Such prototype sails with a mass between 50 and 150 kg plus a micro-spacecraft of 50 to 250 kg would have a maximum acceleration in the order of 0.1 mm/s2 at 1 AU, corresponding to a maximum ∆V-capability of about 3 km/s per year. Two near/medium-term mission examples to a near-Earth asteroid (NEA) will be discussed: a rendezvous mission and a sample return mission.}, language = {en} } @incollection{Dachwald2010, author = {Dachwald, Bernd}, title = {Solar sail dynamics and control}, series = {Encyclopedia of Aerospace Engineering}, booktitle = {Encyclopedia of Aerospace Engineering}, publisher = {Wiley}, address = {Hoboken}, doi = {10.1002/9780470686652.eae292}, year = {2010}, abstract = {Solar sails are large and lightweight reflective structures that are propelled by solar radiation pressure. This chapter covers their orbital and attitude dynamics and control. First, the advantages and limitations of solar sails are discussed and their history and development status is outlined. Because the dynamics of solar sails is governed by the (thermo-)optical properties of the sail film, the basic solar radiation pressure force models have to be described and compared before parameters to measure solar sail performance can be defined. The next part covers the orbital dynamics of solar sails for heliocentric motion, planetocentric motion, and motion at Lagrangian equilibrium points. Afterwards, some advanced solar radiation pressure force models are described, which allow to quantify the thrust force on solar sails of arbitrary shape, the effects of temperature, of light incidence angle, of surface roughness, and the effects of optical degradation of the sail film in the space environment. The orbital motion of a solar sail is strongly coupled to its rotational motion, so that the attitude control of these soft and flexible structures is very challenging, especially for planetocentric orbits that require fast attitude maneuvers. Finally, some potential attitude control methods are sketched and selection criteria are given.}, language = {en} } @article{ValeroBungErpicumetal.2022, author = {Valero, Daniel and Bung, Daniel Bernhard and Erpicum, Sebastien and Peltier, Yann and Dewals, Benjamin}, title = {Unsteady shallow meandering flows in rectangular reservoirs: a modal analysis of URANS modelling}, series = {Journal of Hydro-environment Research}, journal = {Journal of Hydro-environment Research}, number = {In Press}, publisher = {Elsevier}, address = {Amsterdam}, issn = {1570-6443}, doi = {10.1016/j.jher.2022.03.002}, year = {2022}, abstract = {Shallow flows are common in natural and human-made environments. Even for simple rectangular shallow reservoirs, recent laboratory experiments show that the developing flow fields are particularly complex, involving large-scale turbulent structures. For specific combinations of reservoir size and hydraulic conditions, a meandering jet can be observed. While some aspects of this pseudo-2D flow pattern can be reproduced using a 2D numerical model, new 3D simulations, based on the unsteady Reynolds-Averaged Navier-Stokes equations, show consistent advantages as presented herein. A Proper Orthogonal Decomposition was used to characterize the four most energetic modes of the meandering jet at the free surface level, allowing comparison against experimental data and 2D (depth-averaged) numerical results. Three different isotropic eddy viscosity models (RNG k-ε, k-ε, k-ω) were tested. The 3D models accurately predicted the frequency of the modes, whereas the amplitudes of the modes and associated energy were damped for the friction-dominant cases and augmented for non-frictional ones. The performance of the three turbulence models remained essentially similar, with slightly better predictions by RNG k-ε model in the case with the highest Reynolds number. Finally, the Q-criterion was used to identify vortices and study their dynamics, assisting on the identification of the differences between: i) the three-dimensional phenomenon (here reproduced), ii) its two-dimensional footprint in the free surface (experimental observations) and iii) the depth-averaged case (represented by 2D models).}, language = {en} } @inproceedings{GrundmannBodenCeriottietal.2017, author = {Grundmann, Jan Thimo and Boden, Ralf and Ceriotti, Matteo and Dachwald, Bernd and Dumont, Etienne and Grimm, Christian D. and Lange, Caroline and Lichtenheldt, Roy and Pelivan, Ivanka and Peloni, Alessandro and Riemann, Johannes and Spr{\"o}witz, Tom and Tardivel, Simon}, title = {Soil to sail-asteroid landers on near-term sailcraft as an evolution of the GOSSAMER small spacecraft solar sail concept for in-situ characterization}, series = {5th IAA Planetary Defense Conference}, booktitle = {5th IAA Planetary Defense Conference}, pages = {30 Seiten}, year = {2017}, language = {en} } @inproceedings{DachwaldKahleWie2007, author = {Dachwald, Bernd and Kahle, Ralph and Wie, Bong}, title = {Head-on impact deflection of NEAs: a case study for 99942 Apophis}, series = {Planetary Defense Conference 2007}, booktitle = {Planetary Defense Conference 2007}, pages = {1 -- 12}, year = {2007}, abstract = {Near-Earth asteroid (NEA) 99942 Apophis provides a typical example for the evolution of asteroid orbits that lead to Earth-impacts after a close Earth-encounter that results in a resonant return. Apophis will have a close Earth-encounter in 2029 with potential very close subsequent Earth-encounters (or even an impact) in 2036 or later, depending on whether it passes through one of several less than 1 km-sized gravitational keyholes during its 2029-encounter. A pre-2029 kinetic impact is a very favorable option to nudge the asteroid out of a keyhole. The highest impact velocity and thus deflection can be achieved from a trajectory that is retrograde to Apophis orbit. With a chemical or electric propulsion system, however, many gravity assists and thus a long time is required to achieve this. We show in this paper that the solar sail might be the better propulsion system for such a mission: a solar sail Kinetic Energy Impactor (KEI) spacecraft could impact Apophis from a retrograde trajectory with a very high relative velocity (75-80 km/s) during one of its perihelion passages. The spacecraft consists of a 160 m × 160 m, 168 kg solar sail assembly and a 150 kg impactor. Although conventional spacecraft can also achieve the required minimum deflection of 1 km for this approx. 320 m-sized object from a prograde trajectory, our solar sail KEI concept also allows the deflection of larger objects. For a launch in 2020, we also show that, even after Apophis has flown through one of the gravitational keyholes in 2029, the solar sail KEI concept is still feasible to prevent Apophis from impacting the Earth, but many KEIs would be required for consecutive impacts to increase the total Earth-miss distance to a safe value}, language = {en} } @article{BhattaraiHorbachStaatetal.2022, author = {Bhattarai, Aroj and Horbach, Andreas and Staat, Manfred and Kowalczyk, Wojciech and Tran, Thanh Ngoc}, title = {Virgin passive colon biomechanics and a literature review of active contraction constitutive models}, series = {Biomechanics}, volume = {2}, journal = {Biomechanics}, number = {2}, publisher = {MDPI}, address = {Basel}, issn = {2673-7078}, doi = {10.3390/biomechanics2020013}, pages = {138 -- 157}, year = {2022}, abstract = {The objective of this paper is to present our findings on the biomechanical aspects of the virgin passive anisotropic hyperelasticity of the porcine colon based on equibiaxial tensile experiments. Firstly, the characterization of the intestine tissues is discussed for a nearly incompressible hyperelastic fiber-reinforced Holzapfel-Gasser-Ogden constitutive model in virgin passive loading conditions. The stability of the evaluated material parameters is checked for the polyconvexity of the adopted strain energy function using positive eigenvalue constraints of the Hessian matrix with MATLAB. The constitutive material description of the intestine with two collagen fibers in the submucosal and muscular layer each has been implemented in the FORTRAN platform of the commercial finite element software LS-DYNA, and two equibiaxial tensile simulations are presented to validate the results with the optical strain images obtained from the experiments. Furthermore, this paper also reviews the existing models of the active smooth muscle cells, but these models have not been computationally studied here. The review part shows that the constitutive models originally developed for the active contraction of skeletal muscle based on Hill's three-element model, Murphy's four-state cross-bridge chemical kinetic model and Huxley's sliding-filament hypothesis, which are mainly used for arteries, are appropriate for numerical contraction numerical analysis of the large intestine.}, language = {en} } @inproceedings{HandschuhStollenwerkBorchert2021, author = {Handschuh, Nils and Stollenwerk, Dominik and Borchert, J{\"o}rg}, title = {Operation of thermal storage power plants under high renewable grid penetration}, series = {NEIS 2021: Conference on Sustainable Energy Supply and Energy Storage Systems}, booktitle = {NEIS 2021: Conference on Sustainable Energy Supply and Energy Storage Systems}, publisher = {VDE Verlag}, address = {Berlin}, isbn = {978-3-8007-5651-3}, pages = {261 -- 265}, year = {2021}, abstract = {The planned coal phase-out in Germany by 2038 will lead to the dismantling of power plants with a total capacity of approx. 30 GW. A possible further use of these assets is the conversion of the power plants to thermal storage power plants; the use of these power plants on the day-ahead market is considerably limited by their technical parameters. In this paper, the influence of the technical boundary conditions on the operating times of these storage facilities is presented. For this purpose, the storage power plants were described as an MILP problem and two price curves, one from 2015 with a relatively low renewable penetration (33 \%) and one from 2020 with a high renewable energy penetration (51 \%) are compared. The operating times were examined as a function of the technical parameters and the critical influencing factors were investigated. The thermal storage power plant operation duration and the energy shifted with the price curve of 2020 increases by more than 25 \% compared to 2015.}, language = {en} } @masterthesis{Zaunbrecher2021, type = {Bachelor Thesis}, author = {Zaunbrecher, Fabienne}, title = {Living Spaces - By OASE: Konzeption eines Flagship-Stores mit Wohlf{\"u}hl- und Erlebnis-Spaces}, publisher = {FH Aachen}, address = {Aachen}, pages = {175 Seiten}, year = {2021}, abstract = {Konzeption eines Flagship-Stores mit Wohlf{\"u}hl- und Erlebnis-Spaces Die Bed{\"u}rfnisse von Besuchern und Kunden eines Gesch{\"a}fts haben sich {\"u}ber die letzten Jahre stark ver{\"a}ndert. Sie m{\"o}chten das ihr Kauf zum Erlebnis wird. Auf Basis dieser Erkenntnis wurde im Rahmen dieser Arbeit zusammen mit den Produkten des Weltmarktf{\"u}hrers f{\"u}r Teichtechnik und Aquaristik „OASE - Living Water" ein Storekonzept geschaffen. Dieses verbindet den Verkaufsraum mit unterschiedlichen Erlebniswelten, welche auf die jeweilig ausgestellte Produktkategorie abgestimmt sind. Zus{\"a}tzlich er{\"o}ffnet ein diverser und aufregend gestalteter Gartenbereich der zum Entspannen und Verweilen einl{\"a}dt. Der herausstechende Aspekt des Konzepts ist, dass die Produkte sowohl als reines Produkt, als auch in verbauter Version in Aktion zu sehen sind. Auf diese Art bietet die Marke „OASE - Living Water" ein neues Kauf-Erlebnis an.}, language = {de} } @inproceedings{KronigerHorikawaFunkeetal.2021, author = {Kroniger, Daniel and Horikawa, Atsushi and Funke, Harald and Pf{\"a}ffle, Franziska and Kishimoto, Tsuyoshi and Okada, Koichi}, title = {Experimental and numerical investigation on the effect of pressure on micromix hydrogen combustion}, series = {Conference Proceedings Turbo Expo: Power for Land, Sea and Air, Volume 3A: Combustion, Fuels, and Emissions}, booktitle = {Conference Proceedings Turbo Expo: Power for Land, Sea and Air, Volume 3A: Combustion, Fuels, and Emissions}, publisher = {ASME}, address = {New York, NY}, doi = {10.1115/GT2021-58926}, pages = {11 Seiten}, year = {2021}, abstract = {The micromix (MMX) combustion concept is a DLN gas turbine combustion technology designed for high hydrogen content fuels. Multiple non-premixed miniaturized flames based on jet in cross-flow (JICF) are inherently safe against flashback and ensure a stable operation in various operative conditions. The objective of this paper is to investigate the influence of pressure on the micromix flame with focus on the flame initiation point and the NOx emissions. A numerical model based on a steady RANS approach and the Complex Chemistry model with relevant reactions of the GRI 3.0 mechanism is used to predict the reactive flow and NOx emissions at various pressure conditions. Regarding the turbulence-chemical interaction, the Laminar Flame Concept (LFC) and the Eddy Dissipation Concept (EDC) are compared. The numerical results are validated against experimental results that have been acquired at a high pressure test facility for industrial can-type gas turbine combustors with regard to flame initiation and NOx emissions. The numerical approach is adequate to predict the flame initiation point and NOx emission trends. Interestingly, the flame shifts its initiation point during the pressure increase in upstream direction, whereby the flame attachment shifts from anchoring behind a downstream located bluff body towards anchoring directly at the hydrogen jet. The LFC predicts this change and the NOx emissions more accurately than the EDC. The resulting NOx correlation regarding the pressure is similar to a non-premixed type combustion configuration.}, language = {en} } @inproceedings{HorikawaOkadaYamaguchietal.2021, author = {Horikawa, Atsushi and Okada, Kunio and Yamaguchi, Masato and Aoki, Shigeki and Wirsum, Manfred and Funke, Harald and Kusterer, Karsten}, title = {Combustor development and engine demonstration of micro-mix hydrogen combustion applied to M1A-17 gas turbine}, series = {Conference Proceedings Turbo Expo: Power for Land, Sea and Air, Volume 3B: Combustion, Fuels, and Emissions}, booktitle = {Conference Proceedings Turbo Expo: Power for Land, Sea and Air, Volume 3B: Combustion, Fuels, and Emissions}, doi = {10.1115/GT2021-59666}, pages = {13 Seiten}, year = {2021}, abstract = {Kawasaki Heavy Industries, LTD. (KHI) has research and development projects for a future hydrogen society. These projects comprise the complete hydrogen cycle, including the production of hydrogen gas, the refinement and liquefaction for transportation and storage, and finally the utilization in a gas turbine for electricity and heat supply. Within the development of the hydrogen gas turbine, the key technology is stable and low NOx hydrogen combustion, namely the Dry Low NOx (DLN) hydrogen combustion. KHI, Aachen University of Applied Science, and B\&B-AGEMA have investigated the possibility of low NOx micro-mix hydrogen combustion and its application to an industrial gas turbine combustor. From 2014 to 2018, KHI developed a DLN hydrogen combustor for a 2MW class industrial gas turbine with the micro-mix technology. Thereby, the ignition performance, the flame stability for equivalent rotational speed, and higher load conditions were investigated. NOx emission values were kept about half of the Air Pollution Control Law in Japan: 84ppm (O2-15\%). Hereby, the elementary combustor development was completed. From May 2020, KHI started the engine demonstration operation by using an M1A-17 gas turbine with a co-generation system located in the hydrogen-fueled power generation plant in Kobe City, Japan. During the first engine demonstration tests, adjustments of engine starting and load control with fuel staging were investigated. On 21st May, the electrical power output reached 1,635 kW, which corresponds to 100\% load (ambient temperature 20 °C), and thereby NOx emissions of 65 ppm (O2-15, 60 RH\%) were verified. Here, for the first time, a DLN hydrogen-fueled gas turbine successfully generated power and heat.}, language = {en} } @inproceedings{KronigerHorikawaFunkeetal.2021, author = {Kroniger, Daniel and Horikawa, Atsushi and Funke, Harald and Pf{\"a}ffle, Franziska}, title = {Numerical investigation of micromix hydrogen flames at different combustor pressure levels}, series = {The Proceedings of the International Conference on Power Engineering (ICOPE)}, booktitle = {The Proceedings of the International Conference on Power Engineering (ICOPE)}, doi = {10.1299/jsmeicope.2021.15.2021-0237}, pages = {4 Seiten}, year = {2021}, abstract = {This study investigates the influence of pressure on the temperature distribution of the micromix (MMX) hydrogen flame and the NOx emissions. A steady computational fluid dynamic (CFD) analysis is performed by simulating a reactive flow with a detailed chemical reaction model. The numerical analysis is validated based on experimental investigations. A quantitative correlation is parametrized based on the numerical results. We find, that the flame initiation point shifts with increasing pressure from anchoring behind a downstream located bluff body towards anchoring upstream at the hydrogen jet. The numerical NOx emissions trend regarding to a variation of pressure is in good agreement with the experimental results. The pressure has an impact on both, the residence time within the maximum temperature region and on the peak temperature itself. In conclusion, the numerical model proved to be adequate for future prototype design exploration studies targeting on improving the operating range.}, language = {en} }