Refine
Year of publication
- 2024 (93) (remove)
Institute
- Fachbereich Gestaltung (21)
- Fachbereich Medizintechnik und Technomathematik (21)
- Fachbereich Bauingenieurwesen (14)
- Fachbereich Elektrotechnik und Informationstechnik (14)
- Fachbereich Wirtschaftswissenschaften (10)
- IfB - Institut für Bioengineering (10)
- Fachbereich Luft- und Raumfahrttechnik (6)
- INB - Institut für Nano- und Biotechnologien (5)
- Fachbereich Chemie und Biotechnologie (4)
- ECSM European Center for Sustainable Mobility (3)
Has Fulltext
- no (93) (remove)
Document Type
- Article (32)
- Bachelor Thesis (20)
- Part of a Book (17)
- Conference Proceeding (11)
- Book (5)
- Working Paper (5)
- Preprint (2)
- Patent (1)
Keywords
- Nachhaltigkeit (3)
- Deutschland (2)
- Dokumentarfilm (2)
- Engineering education (2)
- Hot S-parameter (2)
- 1P hub loads (1)
- 3-D printing (1)
- 316L (1)
- 3D-Druck (1)
- ABE (1)
Die Arbeit widmet sich der Ursprungsanalyse des Fahrer:innenmangels und präsentiert einen Lösungsansatz durch die Entwicklung einer neu gestalteten Fahrkabine für Lastkraftwagen. Hierbei berücksichtigt das Projekt sowohl die Bedürfnisse der Fahrer:innen als auch die Anforderungen der Unternehmer:innen, um den Anforderungen der zukünftigen Generation gerecht zu werden. Die Rolle der Berufskraftfahrer:innen wird sich wandeln, wobei die Aufgaben über das reine Führen eines Fahrzeugs hinausgehen. Diese Veränderungen erfordern auch Anpassungen an der Arbeitsumgebung, insbesondere an der Fahrkabine, um das Arbeiten, Wohnen und Schlafen auf begrenztem Raum zu ermöglichen. Möglich durch neue Technologien, Richtlinien und neue Herangehensweisen geht der „SOLODRIVER“ in den Themen Design und Raumnutzung neue Wege und zeigt damit was in Zukunft möglich ist.
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.
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.
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.
Tracking healthy habits : Digitale Anwendung zur Förderung von gesunder
Ernährung und Verhalten
(2024)
"Tracking healthy habits" ist eine App, die darauf abzielt, gesündere Essgewohnheiten und mehr Bewegung zu fördern, indem sie verschiedene messbare Metriken erfasst. Die Anwendung legt einen besonderen Schwerpunkt auf das Verfolgen von Kalorien, um Nutzer:innen dabei zu helfen, ihre tägliche Kalorienaufnahme zu kontrollieren und ein besseres Verständnis für Lebensmittel zu entwickeln. Ein übermäßiger Konsum ungesunder Lebensmittel und Bewegungsmangel können sich negativ auf den geistigen und körperlichen Zustand auswirken. Daher unterstützt diese App Nutzer:innen dabei, gesündere Gewohnheiten zu entwickeln und Disziplin zu fördern. Die Hauptziele von "Tracking Healthy Habits" sind die Förderung gesünderer Essgewohnheiten, die Unterstützung langfristiger Verhaltensänderungen durch kontinuierliches Monitoring und die Verbesserung der körperlichen sowie geistigen Gesundheit.
Harte Arbeit, Hunger, Unterkühlung und Ungewissheit – dies war der normale Alltag der Trudarmee im 2. Weltkrieg. Ekatharina, eine deutsche Sowjetbürgerin, wurde wie viele andere gegen ihren Willen in diese Armee eingezogen. Die Bachelorarbeit „Ekatharina – Leben in der Trudarmee“ behandelt den Lebensabschnitt einer Überlebenden, 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, Bäume fällen oder Stämme schleppen. Das Projekt soll nicht nur die Erinnerungen und das kulturelle Gut bewahren, es soll auch die Familiengeschichte erforschen, die Vergangenheit verständlich gestalten und die beteiligten Personen in Ehren halten.
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.
This paper presents a thermal simulation environment for moving objects on the lunar surface. The goal of the thermal simulation environment is to enable the reliable prediction of the temperature development of a given object on the lunar surface by providing the respective heat fluxes for a mission on a given travel path. The user can import any object geometry and freely define the path that the object should travel. Using the path of the object, the relevant lunar surface geometry is imported from a digital elevation model. The relevant parts of the lunar surface are determined based on distance to the defined path. A thermal model of these surface sections is generated, consisting of a porous layer on top and a denser layer below. The object is moved across the lunar surface, and its inclination is adapted depending on the slope of the terrain below it. Finally, a transient thermal analysis of the object and its environment is performed at several positions on its path and the results are visualized. The paper introduces details on the thermal modeling of the lunar surface, as well as its verification. Furthermore, the structure of the created software is presented. The robustness of the environment is verified with the help of sensitivity studies and possible improvements are presented.
Critical quantitative evaluation of integrated health management methods for fuel cell applications
(2024)
Online fault diagnostics is a crucial consideration for fuel cell systems, particularly in mobile applications, to limit downtime and degradation, and to increase lifetime. Guided by a critical literature review, in this paper an overview of Health management systems classified in a scheme is presented, introducing commonly utilised methods to diagnose FCs in various applications. In this novel scheme, various Health management system methods are summarised and structured to provide an overview of existing systems including their associated tools. These systems are classified into four categories mainly focused on model-based and non-model-based systems. The individual methods are critically discussed when used individually or combined aimed at further understanding their functionality and suitability in different applications. Additionally, a tool is introduced to evaluate methods from each category based on the scheme presented. This tool applies the technique of matrix evaluation utilising several key parameters to identify the most appropriate methods for a given application. Based on this evaluation, the most suitable methods for each specific application are combined to build an integrated Health management system.
In der wasserbaulichen Forschung werden neben klassischen Messinstrumenten zunehmend kamerabasierte Verfahren genutzt. Diese erlauben neben der Bestimmung von Fließgeschwindigkeiten auch die Detektion der freien Wasseroberfläche oder zeitliche Vermessung von Kolken. Durch die hohen räumlichen und zeitlichen Auflösungen, welche neueste Kamerasensoren liefern, können neue Erkenntnisse in turbulenten, komplexen Strömungen gewonnen werden. Auch in der Praxis können diese Verfahren mit geringem Aufwand wichtige Daten liefern.
Mathematical morphology is a part of image processing that has proven to be fruitful for numerous applications. Two main operations in mathematical morphology are dilation and erosion. These are based on the construction of a supremum or infimum with respect to an order over the tonal range in a certain section of the image. The tonal ordering can easily be realised in grey-scale morphology, and some morphological methods have been proposed for colour morphology. However, all of these have certain limitations.
In this paper we present a novel approach to colour morphology extending upon previous work in the field based on the Loewner order. We propose to consider an approximation of the supremum by means of a log-sum exponentiation introduced by Maslov. We apply this to the embedding of an RGB image in a field of symmetric 2x2 matrices. In this way we obtain nearly isotropic matrices representing colours and the structural advantage of transitivity. In numerical experiments we highlight some remarkable properties of the proposed approach.
Direct sampling method via Landweber iteration for an absorbing scatterer with a conductive boundary
(2024)
In this paper, we consider the inverse shape problem of recovering isotropic scatterers with a conductive boundary condition. Here, we assume that the measured far-field data is known at a fixed wave number. Motivated by recent work, we study a new direct sampling indicator based on the Landweber iteration and the factorization method. Therefore, we prove the connection between these reconstruction methods. The method studied here falls under the category of qualitative reconstruction methods where an imaging function is used to recover the absorbing scatterer. We prove stability of our new imaging function as well as derive a discrepancy principle for recovering the regularization parameter. The theoretical results are verified with numerical examples to show how the reconstruction performs by the new Landweber direct sampling method.
We consider the numerical approximation of second-order semi-linear parabolic stochastic partial differential equations interpreted in the mild sense which we solve on general two-dimensional domains with a C² boundary with homogeneous Dirichlet boundary conditions. The equations are driven by Gaussian additive noise, and several Lipschitz-like conditions are imposed on the nonlinear function. We discretize in space with a spectral Galerkin method and in time using an explicit Euler-like scheme. For irregular shapes, the necessary Dirichlet eigenvalues and eigenfunctions are obtained from a boundary integral equation method. This yields a nonlinear eigenvalue problem, which is discretized using a boundary element collocation method and is solved with the Beyn contour integral algorithm. We present an error analysis as well as numerical results on an exemplary asymmetric shape, and point out limitations of the approach.
Wie kann man das Thema Forschungsdatenmanagement (FDM) konkret und anwendbar für Forschende gestalten, die bisher noch wenig Kontakt damit hatten? Auf diese Frage gibt das Konzept „30 Minuten FDM für HAW. Ein Informationsformat für Forschende an HAW in NRW“ eine Antwort. Es entstand als Projektarbeit im Zertifikatskurs Forschungsdatenmanagement 2023/24
Ingenieurwissenschaften im Fokus: Zugänge zu einem effektiven Forschungsdatenmanagement an HAW
(2024)
Im Rahmen der Love Data Week vom 12. bis 16.02.2024 haben die BMBF-Projekte FDM2_TH_Koeln der TH Köln (FK 16FDFH105) und Persist@HAW der FH Aachen (FK 16FDFH129) am 15.02.2024 gemeinsam eine Online-Veranstaltung mit dem Titel „Ingenieurwissenschaften im Fokus: Zugänge zu einem effektiven Forschungsdatenmanagement an HAW“ angeboten. Diese richtete sich an Forschende aus den Ingenieurwissenschaften, die einen ersten Zugang zum Thema Forschungsdatenmanagement (FDM) suchen und erfahren möchten, welche speziellen Angebote für die Daten aus den Ingenieurwissenschaften existieren.
In der Veranstaltung wurden wesentliche Aspekte des Forschungsdatenmanagements entlang des Datenlebenszyklus beleuchtet. Ziel war es, den Teilnehmenden praxisnahe Einblicke und Hilfestellungen zu einem effektiven Umgang mit Forschungsdaten an Hochschulen für Angewandte Wissenschaften (HAW) zu bieten. Durch Beispiele und konkrete Empfehlungen wurde das Thema zugänglich gemacht.
Um die Forschungsdatenmanagement-Plattform Coscine optimal für Forschungsprojekte nutzen zu können, ist es sinnvoll, einige Fragen im Vorhinein zu klären. So können aufwendige Änderungen der Datenverwaltung im Nachhinein vermieden werden. Hierzu bietet die Handreichung hilfreiche Leitfragen und Erläuterungen für Forschende und FDM-Service-Personal an HAW in NRW (DH.NRW-Hochschulen).
FDM-Service-Mitarbeitende können die Handreichung in ihrer Beratung zu Coscine einsetzen und mit der Eingabemaske in der Kopfzeile des Dokuments auf ihre Hochschule anpassen.
Welche Vorteile bietet die Forschungsdatenmanagement-Plattform Coscine für die Verwaltung von Daten in Forschungsprojekten? Hierzu gibt die Handreichung einen schnellen Überblick über den landesgeförderten Dienst Coscine für Forschende und FDM-Service-Personal an HAW in NRW (DH.NRW-Hochschulen).
FDM-Service-Mitarbeitende können die Handreichung in ihrer Beratung zu Coscine einsetzen und mit der Eingabemaske in der Kopfzeile des Dokuments auf ihre Hochschule anpassen.
After a brief introduction of conventional laboratory structures, this work focuses on an innovative and universal approach for a setup of a training laboratory for electric machines and drive systems. The novel approach employs a central 48 V DC bus, which forms the backbone of the structure. Several sets of DC machine, asynchronous machine and synchronous machine are connected to this bus. The advantages of the novel system structure are manifold, both from a didactic and a technical point of view: Student groups can work on their own performance level in a highly parallelized and at the same time individualized way. Additional training setups (similar or different) can easily be added. Only the total power dissipation has to be provided, i.e. the DC bus balances the power flow between the student groups. Comparative results of course evaluations of several cohorts of students are shown.