@masterthesis{Terry2024, type = {Bachelor Thesis}, author = {Terry, Aileen}, title = {Deutsche Parkinson Gesellschaft : Entwicklung eines neuen Erscheinungsbildes f{\"u}r die Deutsche Parkinson Gesellschaft zur F{\"o}rderung des Bewusstseins f{\"u}r die Krankheit}, publisher = {FH Aachen}, address = {Aachen}, school = {Fachhochschule Aachen}, pages = {174 Seiten}, year = {2024}, abstract = {Mehr als 400.000 Menschen in Deutschland sind von Parkinson betroffen, dennoch bleibt diese neurodegenerative Krankheit oft im Schatten anderer Erkrankungen. Diese Bachelorarbeit beleuchtet die Unsichtbarkeit von Parkinson im {\"o}ffentlichen Raum und setzt sich f{\"u}r eine breitere Aufkl{\"a}rung ein. Durch ein neues Corporate Design der Deutschen Parkinson Gesellschaft sowie begleitende Maßnahmen wird angestrebt, Informationen {\"u}ber die Krankheit zu verbreiten und Einblicke in die Lebensumst{\"a}nde der Betroffenen zu gew{\"a}hren. Dies tr{\"a}gt nicht nur zu einer fr{\"u}hzeitigen Diagnosestellung bei, sondern erm{\"o}glicht auch eine verbesserte Unterst{\"u}tzung f{\"u}r Patient:innen und ihre Angeh{\"o}rigen. Ein Aufruf, gemeinsam mit den Betroffenen Vorurteile zu {\"u}berwinden und Parkinson sichtbar zu machen. Mit dem Ziel Parkinson irgendwann heilem zu k{\"o}nnen.}, language = {de} } @masterthesis{Tiller2024, type = {Bachelor Thesis}, author = {Tiller, Alicia}, title = {Die G{\"o}ttin in dir : Arbeitsbuch zu den weiblichen Rhythmen}, publisher = {FH Aachen}, address = {Aachen}, school = {Fachhochschule Aachen}, pages = {123 Seiten}, year = {2024}, abstract = {Was verbindet der Mond, die Jahreszeiten und das Weibliche dieser Erde? Das sich immerfort drehende Rad der Zyklen. In vergangenen Zeiten nutzten Frauen den Menstruationszyklus und die Weisheit der Natur als Quelle der Kraft - f{\"u}r kreative, emotionale, geistige und k{\"o}rperliche F{\"u}hrung durch das Leben. Dieses alte Wissen ist noch heute durch Geschichten und Mythen unserer Welt erfahrbar. Das Arbeitsbuch „Die G{\"o}ttin in dir" begleitet Leser:innen auf diesen Spuren durch die Welten der Zyklen und Rhythmen aus der Kulturhistorie, Biologie und dem indigenen Wissen. Die Ebene der Selbstreflexion in diesem Buch bietet dabei eine aktive Methode, die Nutzer:innen dazu bef{\"a}higt, in die Umsetzung zu gehen und den Prozess der zyklischen Reise der Natur zu begleiten. Das Konzept des Buches zielt darauf ab, eine Verbindung zwischen der Selbsterfahrung im Kontext weiblicher Archetypen, dem Menstruationszyklus, nat{\"u}rlichen Rhythmen und ethnologischen Techniken herzustellen. Die Absicht ist es, die individuelle Erfahrung jeder Frau zu st{\"a}rken, das Selbstvertrauen zu f{\"o}rdern und den Mut zur Vielfalt zu aktivieren. Es geht darum, unsere angeborene, instinktive Natur in uns wieder zu erwecken. Die Stimme der G{\"o}ttin fl{\"u}stert uns zu und ruft ihre T{\"o}chter. Denn die Melodie, die in dir erklingt, m{\"o}chte geh{\"o}rt werden.}, language = {de} } @article{AkimbekovDigelTastambeketal.2024, author = {Akimbekov, Nuraly S. and Digel, Ilya and Tastambek, Kuanysh T. and Kozhahmetova, Marzhan and Sherelkhan, Dinara K. and Tauanov, Zhandos}, title = {Hydrogenotrophic methanogenesis in coal-bearing environments: Methane production, carbon sequestration, and hydrogen availability}, series = {International Journal of Hydrogen Energy}, volume = {52}, journal = {International Journal of Hydrogen Energy}, number = {Part D}, publisher = {Elsevier}, address = {New York}, issn = {1879-3487 (online)}, doi = {10.1016/j.ijhydene.2023.09.223}, pages = {1264 -- 1277}, year = {2024}, abstract = {Methane is a valuable energy source helping to mitigate the growing energy demand worldwide. However, as a potent greenhouse gas, it has also gained additional attention due to its environmental impacts. The biological production of methane is performed primarily hydrogenotrophically from H2 and CO2 by methanogenic archaea. Hydrogenotrophic methanogenesis also represents a great interest with respect to carbon re-cycling and H2 storage. The most significant carbon source, extremely rich in complex organic matter for microbial degradation and biogenic methane production, is coal. Although interest in enhanced microbial coalbed methane production is continuously increasing globally, limited knowledge exists regarding the exact origins of the coalbed methane and the associated microbial communities, including hydrogenotrophic methanogens. Here, we give an overview of hydrogenotrophic methanogens in coal beds and related environments in terms of their energy production mechanisms, unique metabolic pathways, and associated ecological functions.}, language = {en} } @article{WindmuellerSchapsZantisetal.2024, author = {Windm{\"u}ller, Anna and Schaps, Kristian and Zantis, Frederik and Domgans, Anna and Taklu, Bereket Woldegbreal and Yang, Tingting and Tsai, Chih-Long and Schierholz, Roland and Yu, Shicheng and Kungl, Hans and Tempel, Hermann and Dunin-Borkowski, Rafal E. and H{\"u}ning, Felix and Hwang, Bing Joe and Eichel, R{\"u}diger-A.}, title = {Electrochemical activation of LiGaO2: implications for ga-doped garnet solid electrolytes in li-metal batteries}, series = {ACS Applied Materials \& Interfaces}, volume = {16}, journal = {ACS Applied Materials \& Interfaces}, number = {30}, publisher = {ACS Publications}, address = {Washington, DC}, issn = {39181-3919}, doi = {10.1021/acsami.4c03729}, pages = {14 Seiten}, year = {2024}, abstract = {Ga-doped Li7La3Zr2O12 garnet solid electrolytes exhibit the highest Li-ion conductivities among the oxide-type garnet-structured solid electrolytes, but instabilities toward Li metal hamper their practical application. The instabilities have been assigned to direct chemical reactions between LiGaO2 coexisting phases and Li metal by several groups previously. Yet, the understanding of the role of LiGaO2 in the electrochemical cell and its electrochemical properties is still lacking. Here, we are investigating the electrochemical properties of LiGaO2 through electrochemical tests in galvanostatic cells versus Li metal and complementary ex situ studies via confocal Raman microscopy, quantitative phase analysis based on powder X-ray diffraction, energy-dispersive X-ray spectroscopy, X-ray photoelectron spectroscopy, and electron energy loss spectroscopy. The results demonstrate considerable and surprising electrochemical activity, with high reversibility. A three-stage reaction mechanism is derived, including reversible electrochemical reactions that lead to the formation of highly electronically conducting products. The results have considerable implications for the use of Ga-doped Li7La3Zr2O12 electrolytes in all-solid-state Li-metal battery applications and raise the need for advanced materials engineering to realize Ga-doped Li7La3Zr2O12for practical use.}, language = {en} } @article{EichlerBalcBremenetal.2024, author = {Eichler, Fabian and Balc, Nicolae and Bremen, Sebastian and Nink, Philipp}, title = {Investigation of laser powder bed fusion parameters with respect to their influence on the thermal conductivity of 316L samples}, series = {Journal of Manufacturing and Materials Processing}, volume = {8}, journal = {Journal of Manufacturing and Materials Processing}, number = {4}, publisher = {MDPI}, address = {Basel}, issn = {2504-4494}, doi = {10.3390/jmmp8040166}, pages = {12 Seiten}, year = {2024}, abstract = {The thermal conductivity of components manufactured using Laser Powder Bed Fusion (LPBF), also called Selective Laser Melting (SLM), plays an important role in their processing. Not only does a reduced thermal conductivity cause residual stresses during the process, but it also makes subsequent processes such as the welding of LPBF components more difficult. This article uses 316L stainless steel samples to investigate whether and to what extent the thermal conductivity of specimens can be influenced by different LPBF parameters. To this end, samples are set up using different parameters, orientations, and powder conditions and measured by a heat flow meter using stationary analysis. The heat flow meter set-up used in this study achieves good reproducibility and high measurement accuracy, so that comparative measurements between the various LPBF influencing factors to be tested are possible. In summary, the series of measurements show that the residual porosity of the components has the greatest influence on conductivity. The degradation of the powder due to increased recycling also appears to be detectable. The build-up direction shows no detectable effect in the measurement series.}, language = {en} } @article{ZhantlessovaSavitskayaKistaubayevaetal.2024, author = {Zhantlessova, Sirina and Savitskaya, Irina and Kistaubayeva, Aida and Ignatova, Ludmila and Talipova, Aizhan and Pogrebnjak, Alexander and Digel, Ilya}, title = {Correction: Zhantlessova et al. advanced "Green" prebiotic composite of bacterial cellulose/pullulan based on synthetic biology-powered microbial coculture strategy. Polymers 2022, 14, 3224}, series = {Polymers}, volume = {16}, journal = {Polymers}, number = {13}, publisher = {MDPI}, address = {Basel}, issn = {2073-4360}, doi = {10.3390/polym16131802}, pages = {2 Seiten}, year = {2024}, language = {en} } @inproceedings{DachwaldOhndorfSpurmannetal.2009, author = {Dachwald, Bernd and Ohndorf, Andreas and Spurmann, J. and Loeb, H. W. and Schartner, Karl-Heinz and Seboldt, Wolfgang}, title = {Mission design for a SEP mission to saturn}, series = {60th International Astronautical Congress 2009 (IAC 2009)}, booktitle = {60th International Astronautical Congress 2009 (IAC 2009)}, publisher = {Curran Associates, Inc.}, address = {Red Hook, NY}, isbn = {978-1-61567-908-9}, pages = {11 Seiten}, year = {2009}, abstract = {Within ESA's Cosmic Vision 2015-2025 plan, a mission to explore the Saturnian System, with special emphasis on its two moons Titan and Enceladus, was selected for study, termed TANDEM (Titan and Enceladus Mission). In this paper, we describe an optimized mission design for a TANDEM-derived solar electric propulsion (SEP) mission. We have chosen the SEP mission scenario for the interplanetary transfer of the TANDEM spacecraft because all feasible gravity assist sequences for a chemical transfer between 2015 and 2025 result in long flight times of about nine years. Our SEP system is based on the German RIT ion engine. For our optimized mission design, we have extensively explored the SEP parameter space (specific impulse, thrust level, power level) and have calculated an optimal interplanetary trajectory for each setting. In contrast to the original TANDEM mission concept, which intends to use two launch vehicles and an all-chemical transfer, our SEP mission design requires only a single Ariane 5 ECA launch for the same payload mass. Without gravity assist, it yields a faster and more flexible transfer with a fight time of less than seven years, and an increased payload ratio. Our mission design proves thereby the capability of SEP even for missions into the outer solar system.}, language = {en} } @incollection{AtmaneHirechKassmietal.2020, author = {Atmane, Ilias and Hirech, Kamal and Kassmi, K. and Mahdi, Zahra and Alexopoulos, Spiros and Schwarzer, Klemens and Chayeb, H. and Bachiri, Najib}, title = {Design and realization of a pilot solar desalination plant in Douar El Hamri in the province of Berkane (Morocco)}, series = {Sustainable entrepreneurship, renewable energy-based projects, and digitalization}, booktitle = {Sustainable entrepreneurship, renewable energy-based projects, and digitalization}, editor = {Omrane, Amina and Kassmi, Khalil and Akram, Muhammad Wasim and Khanna, Ashish and Mostafiz, Imtiaz}, publisher = {CRC Press}, address = {Boca Raton, Fa.}, isbn = {9781000292541 (E-Book)}, pages = {18 Seiten}, year = {2020}, abstract = {Producing fresh water from saline water has become one of the most difficult challenges to overcome especially with the high demand and shortage of fresh water. In this context, as part of a collaboration with Germany, the authors propose a design and implementation of a pilot multi-stage solar desalination system (MSD), remotely controlled, at Douar Al Hamri in the rural town of Boughriba in the province of Berkane, Morocco. More specifically, they present their contribution on the remote control and supervision system, which makes the functioning of the MSD system reliable and guarantees the production of drinking water for the population of Douar. The results obtained show that the electronic cards and computer communication software implemented allow the acquisition of all electrical (currents, voltages, powers, yields), thermal (temperatures of each stage), and meteorological (irradiance and ambient temperature), remote control and maintenance (switching on, off, data transfer). By comparing with the literature carried out in the field of solar energy, the authors conclude that the MSD and electronic desalination systems realized during this work represent a contribution in terms of the reliability and durability of providing drinking water in rural and urban areas.}, language = {en} } @masterthesis{Naujoks2024, type = {Bachelor Thesis}, author = {Naujoks, Christian}, title = {Tracking healthy habits : Digitale Anwendung zur F{\"o}rderung von gesunder Ern{\"a}hrung und Verhalten}, publisher = {FH Aachen}, address = {Aachen}, pages = {293 Seiten}, year = {2024}, abstract = {"Tracking healthy habits" ist eine App, die darauf abzielt, ges{\"u}ndere Essgewohnheiten und mehr Bewegung zu f{\"o}rdern, indem sie verschiedene messbare Metriken erfasst. Die Anwendung legt einen besonderen Schwerpunkt auf das Verfolgen von Kalorien, um Nutzer:innen dabei zu helfen, ihre t{\"a}gliche Kalorienaufnahme zu kontrollieren und ein besseres Verst{\"a}ndnis f{\"u}r Lebensmittel zu entwickeln. Ein {\"u}berm{\"a}ßiger Konsum ungesunder Lebensmittel und Bewegungsmangel k{\"o}nnen sich negativ auf den geistigen und k{\"o}rperlichen Zustand auswirken. Daher unterst{\"u}tzt diese App Nutzer:innen dabei, ges{\"u}ndere Gewohnheiten zu entwickeln und Disziplin zu f{\"o}rdern. Die Hauptziele von "Tracking Healthy Habits" sind die F{\"o}rderung ges{\"u}nderer Essgewohnheiten, die Unterst{\"u}tzung langfristiger Verhaltens{\"a}nderungen durch kontinuierliches Monitoring und die Verbesserung der k{\"o}rperlichen sowie geistigen Gesundheit.}, language = {de} } @masterthesis{Plevako2024, type = {Bachelor Thesis}, author = {Plevako, Ludmilla}, title = {Ekatharina : Leben in der Trudarmee}, publisher = {FH Aachen}, address = {Aachen}, pages = {59 Seiten}, year = {2024}, abstract = {Harte Arbeit, Hunger, Unterk{\"u}hlung und Ungewissheit - dies war der normale Alltag der Trudarmee im 2. Weltkrieg. Ekatharina, eine deutsche Sowjetb{\"u}rgerin, wurde wie viele andere gegen ihren Willen in diese Armee eingezogen. Die Bachelorarbeit „Ekatharina - Leben in der Trudarmee" behandelt den Lebensabschnitt einer {\"U}berlebenden, der Urgroßmutter der Autorin, in Form eines Graphic Novels. In der Trudarmee, auch Arbeitsarmee genannt, musste sie unter schweren Bedingungen Zwangsarbeit verrichten, wie arbeiten in der Schmiede, B{\"a}ume f{\"a}llen oder St{\"a}mme schleppen. Das Projekt soll nicht nur die Erinnerungen und das kulturelle Gut bewahren, es soll auch die Familiengeschichte erforschen, die Vergangenheit verst{\"a}ndlich gestalten und die beteiligten Personen in Ehren halten.}, language = {de} } @masterthesis{Wiese2024, type = {Bachelor Thesis}, author = {Wiese, Katharina}, title = {Drink me}, publisher = {FH Aachen}, address = {Aachen}, school = {Fachhochschule Aachen}, pages = {39 Seiten}, year = {2024}, abstract = {„Drink me" ist ein Kurzfilm {\"u}ber drei Freunde auf einer Party, auf der ein mysteri{\"o}ses Getr{\"a}nk verteilt wird, das die Partyg{\"a}ste in einen besonderen Rausch versetzt. Die Farben fangen an zu leuchten, die Musik wird klarer, alles f{\"u}hlt sich intensiver an. Bis sich die Wahrnehmung der Protagonistin Ally pl{\"o}tzlich ver{\"a}ndert: Vom bunt leuchtenden Rauschzustand zur scheinbaren Realit{\"a}t: Einem grauen, kalten Bunker voller abgewrackter Gestalten. Ally versucht die Party zu verlassen, doch w{\"a}hrend ihre Wahrnehmungen immer weiter verschwimmen, verliert sie gleichzeitig allm{\"a}hlich ihr Bewusstsein. Der Film bietet durch die Darstellung der verschiedenen Wahrnehmungszust{\"a}nde und das Verschwimmen derer ein visuell besonders spannendes Erlebnis.}, language = {de} } @masterthesis{Zeyen2024, type = {Bachelor Thesis}, author = {Zeyen, Kim}, title = {Seeds : Konzeption und Gestaltung eines Toolkits f{\"u}r die Entwicklung nachhaltiger Webdesigns}, publisher = {FH Aachen}, address = {Aachen}, school = {Fachhochschule Aachen}, pages = {197 Seiten}, year = {2024}, abstract = {Die Menschheit lebt {\"u}ber ihre Verhältnisse: Permanent {\"u}bersteigt unser Verbrauch die uns j{\"a}hrlich zur Verf{\"u}gung stehenden Ressourcen. Der Energiebedarf digitaler Anwendungen wird dabei meist unterschätzt. Wie Interaction-Designer:innen einen Beitrag zur Entwicklung nachhaltiger Websites leisten können, ist aktuell nur durch aufwendige Recherche zu beantworten. Die Bachelorarbeit »Seeds« stellt einen Schritt im Prozess zu mehr Nachhaltigkeit dar. Sie umfasst ein Toolkit, bestehend aus einer Website und einem Plugin f{\"u}r g{\"a}ngige Designtools. Dieses b{\"u}ndelt alle Informationen, um das Internet barriereärmer, sozialer, ethischer und eben auch ökologisch verträglicher zu gestalten. W{\"a}hrend die Website eine Anlaufstelle f{\"u}r den Wissensaufbau darstellt, unterst{\"u}tzt das Plugin bei der Entwicklung eigener Designs, ohne dass Gestalter:innen den Designprozess verlassen m{\"u}ssen.}, language = {de} } @masterthesis{Bonsu2024, type = {Bachelor Thesis}, author = {Bonsu, Joel}, title = {HypnoStress : Implementierung eines Stressmanagement-Controllers f{\"u}r den schulischen Alltag in der Grundschule.}, publisher = {FH Aachen}, address = {Aachen}, school = {Fachhochschule Aachen}, pages = {145 Seiten}, year = {2024}, abstract = {In der heutigen Welt sind Kinder in zunehmendem Maße Stress aus verschiedenen Quellen wie schulischen Anforderungen, famili{\"a}rem Druck und ungewohnten Situationen ausgesetzt. Dieser Aspekt wird von vielen Erwachsenen oft vernachl{\"a}ssigt. Das kann dazu f{\"u}hren, dass sich bei Kindern Frustration und {\"A}rger aufstauen. Insbesondere das schulische Umfeld stellt ein erhebliches Stresspotenzial dar, da von den Kindern hohe Leistungen erwartet werden. Leistungsdruck, soziale Erwartungen und Frustration tragen zu diesem Eindruck bei. Auch der Unterricht bildet da keine Ausnahme und ist aufgrund seiner zentralen Bedeutung eine potenzielle Stressquelle. Als spezialisierter Begleiter bietet HypnoStress den Kindern die M{\"o}glichkeit, mit hypnosebasierten Techniken die Stressoren des Alltags zu bew{\"a}ltigen und sich auf neue Herausforderungen vorzubereiten.}, language = {de} } @masterthesis{Esser2024, type = {Bachelor Thesis}, author = {Esser, Julius}, title = {Ecosystems : Neuinterpretation von Elementen der Savanne zu Objekten zwischen Kunst und Design.}, publisher = {FH Aachen}, address = {Aachen}, school = {Fachhochschule Aachen}, pages = {390 Seiten}, year = {2024}, abstract = {Das Projekt „Ecosystems" (deutsch {\"O}kosysteme) beschreibt die zusammenh{\"a}ngende Entwicklung eines Produktsystems, inspiriert von einzelnen Elementen der afrikanischen Savanne. Das {\"O}kosystem und alle damit verbundenen Strukturen werden als Grundlage f{\"u}r die Konzeption der Objekte genutzt und fortlaufend weitgehend abstrahiert. Die Produktkollektion, bestehend aus sechs verschiedenen M{\"o}beln und Objekten, stellt zusammen das {\"O}kosystem der afrikanischen Savanne dar. Elemente der Savanne k{\"o}nnen ganz unterschiedlicher Natur sein. Sowohl die bekannten Tiere, wie die sogenannten Big Five, kleine Savannenbewohner:innen oder unterschiedliche Pflanzen bilden zusammen die Grundlage f{\"u}r das {\"O}kosystem. Jedes Objekt bezieht die Inspiration dabei aus einem anderen Element der Savanne. Die Grundlage der Objekte bildet dabei nicht allein das optische Erscheinungsbild der Tiere und Pflanzen, sondern vielmehr die damit verbundenen Emotionen und Reaktionen.}, language = {de} } @misc{BiewendtBlaschkeBoehnert2019, author = {Biewendt, Marcel and Blaschke, Florian and B{\"o}hnert, Arno}, title = {The rebound effect: a critical and systematic review on the current state of affairs}, series = {Abstracts of the International Conference on Sustainable Economy and Agriculture}, journal = {Abstracts of the International Conference on Sustainable Economy and Agriculture}, editor = {Koponicsne Gy{\"o}rke, Diana}, publisher = {Universit{\"a}t Kaposv{\´a}r}, address = {Kaposv{\´a}r}, isbn = {978-615-5599-72-9}, pages = {101 -- 101}, year = {2019}, language = {en} } @phdthesis{Biewendt2022, author = {Biewendt, Marcel}, title = {Socio-Economic challenges in sustainability and resource management}, publisher = {Hungarian University of Agriculture and Life Sciences}, pages = {160 Seiten}, year = {2022}, abstract = {This dissertation uses in first stage a macroeconomic investigation to examine the dependence, influence and corruption of socio-economic development through effects of sustainability and resource management. The conducted research found that the state's dependence on its citizens decreases when the state's sources of revenue are largely detached and independent of the citizens' financial resources. In this case, financial resources are taxes and duties provided by the citizens. One possible consequence is the restriction of state investment in its citizens. Both the qualitative literature review and the quantitative data analysis revealed a negative correlation between socio-economic development and the resource economy's share of GDP for the period under study. The microeconomic investigation was primarily conducted through an intensive literature review. It was shown that the rebound effect as such is already very well researched. However, it also became clear that avoidance strategies for the rebound effect and links to sustainability initiatives are scarce or non-existent. The need for a redesign of the impact analysis with regard to technological innovations and their influence on resource consumption and resource management has become clear on the basis of the present study. Further, emerging and developing countries in particular, which will be confronted in the foreseeable future not only with the fundamental problems of resource abundance in the overall economic context, but also with the issues of their sustainable use, should be confronted with these problems as early as possible in order to find solutions in a timely manner.}, language = {de} } @misc{LippoldtRingbeckHuening2023, author = {Lippoldt, Mario and Ringbeck, Thorsten and H{\"u}ning, Felix}, title = {Verfahren und System zur Erkennung von unerlaubten Fahrzeug-{\"U}berholvorg{\"a}ngen in einer {\"U}berholverbotszone eines Fahrwegs}, year = {2023}, language = {de} } @inproceedings{StarkBartelDitscheetal.2023, author = {Stark, Ralf and Bartel, Sebastian and Ditsche, Florian and Esch, Thomas}, title = {Design study of a 30kN LOX/LCH4 aerospike rocket engine for lunar lander application}, series = {Aerospace Europe Conference 2023 - 10th EUCASS - 9th CEAS}, booktitle = {Aerospace Europe Conference 2023 - 10th EUCASS - 9th CEAS}, pages = {9 Seiten}, year = {2023}, abstract = {Based on lunar lander concept EL3, various LOX/CH4 aerospike engines were studied. A distinction was made between single and cluster configurations as well as ideal and non-ideal contour concepts. It could be shown that non-ideal aerospike engines promise a significant payload gain.}, language = {en} } @inproceedings{StarkRiepingEsch2023, author = {Stark, Ralf and Rieping, Carla and Esch, Thomas}, title = {The impact of guide tubes on flow separation in rocket nozzles}, series = {Aerospace Europe Conference 2023 - 10th EUCASS - 9th CEAS}, booktitle = {Aerospace Europe Conference 2023 - 10th EUCASS - 9th CEAS}, pages = {8 Seiten}, year = {2023}, abstract = {Rocket engine test facilities and launch pads are typically equipped with a guide tube. Its purpose is to ensure the controlled and safe routing of the hot exhaust gases. In addition, the guide tube induces a suction that effects the nozzle flow, namely the flow separation during transient start-up and shut-down of the engine. A cold flow subscale nozzle in combination with a set of guide tubes was studied experimentally to determine the main influencing parameters.}, language = {en} } @article{SchopenNarayanBeckmannetal.2024, author = {Schopen, Oliver and Narayan, Sriram and Beckmann, Marvin and Najmi, Aezid-Ul-Hassan and Esch, Thomas and Shabani, Bahman}, title = {An EIS approach to quantify the effects of inlet air relative humidity on the performance of proton exchange membrane fuel cells: a pathway to developing a novel fault diagnostic method}, series = {International Journal of Hydrogen Energy}, volume = {58}, journal = {International Journal of Hydrogen Energy}, number = {8}, publisher = {Elsevier}, address = {Amsterdam}, isbn = {0360-3199 (print)}, issn = {1879-3487 (online)}, doi = {10.1016/j.ijhydene.2024.01.218}, pages = {1302 -- 1315}, year = {2024}, abstract = {In this work, the effect of low air relative humidity on the operation of a polymer electrolyte membrane fuel cell is investigated. An innovative method through performing in situ electrochemical impedance spectroscopy is utilised to quantify the effect of inlet air relative humidity at the cathode side on internal ionic resistances and output voltage of the fuel cell. In addition, algorithms are developed to analyse the electrochemical characteristics of the fuel cell. For the specific fuel cell stack used in this study, the membrane resistance drops by over 39 \% and the cathode side charge transfer resistance decreases by 23 \% after increasing the humidity from 30 \% to 85 \%, while the results of static operation also show an increase of ∼2.2 \% in the voltage output after increasing the relative humidity from 30 \% to 85 \%. In dynamic operation, visible drying effects occur at < 50 \% relative humidity, whereby the increase of the air side stoichiometry increases the drying effects. Furthermore, other parameters, such as hydrogen humidification, internal stack structure, and operating parameters like stoichiometry, pressure, and temperature affect the overall water balance. Therefore, the optimal humidification range must be determined by considering all these parameters to maximise the fuel cell performance and durability. The results of this study are used to develop a health management system to ensure sufficient humidification by continuously monitoring the fuel cell polarisation data and electrochemical impedance spectroscopy indicators.}, language = {en} }