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Working paper
Working Paper: Modeling Infection Risk in Local Public Transport
(2024)
To model the infection risk in local public transport, additional information on the personal contacts during a trip with local public transport as well as the contact duration with them is necessary. As morning student traffic in local public transport vehicles was assumed to hold a high infection risk during the COVID-19 pandemic, staggered school starting times were tested in the city of Herne in Germany. The data obtained during this time was used to create a calculation tool for the number of personal contacts ...
Working paper
Climate Change and Consumption Patterns in Latin America: The Urgency of a Structural Transformation
(2024-02)
• Climate change obstructs Latin America's development, affecting the economy, society, and the environment. A substantial investment is needed for the 2050-2070 deep decarbonization process.
• Latin America's unsustainable development in the last five decades has boosted consumption, employment, and poverty reduction but falls short in addressing chronic poverty and high-income concentration. This undermines economic dynamics and exposes society to climate change impacts.
• A just climate transition requires changes ...
Dissertation
A Unifying Theory for Runge-Kutta-like Time Integrators: Convergence and Stability
(2024)
The work deals with two major topics concerning the numerical analysis of Runge-Kutta-like (RK-like) methods, namely their stability and order of convergence. RK-like methods differ from additive RK methods in that their coefficients are allowed to depend on the solution and the step size. As a result of this, we also refer to them as non-standard additive RK (NSARK) methods. We motivate and introduce modified Patankar (MP) schemes as a subclass of NSARK methods and emphasize their importance. The first major part ...
Dissertation
Immobilization of Neodymium Complexes on Semiconductor Surfaces and Processing of GaAs-based Photonic Crystals
(2024)
Lanthanide ion luminescence exhibits characteristic narrow emission bands ranging from VIS to NIR along with relatively long emission lifetimes which makes them attractive for applications in lighting, sensing, and display technologies. The focus of this dissertation lies on the optical characterization of newly synthesized neodymium complexes bearing phosphonate ester ligands and the fabrication of photonic crystal (PhC) cavities. Micro-photoluminescence (PL) spectroscopy is used to investigate the NIR emission bands ...
Dissertation
New Approaches for the Quantification of Metabolic and Economic Trade-Offs Related to the Health and Longevity of Individual Dairy Cows
(2024)
Background: In dairy cows, negative associations between the genetic merit for milk yield and fitness traits as well as a lack of success in lowering the prevalence of production diseases have been noticed over the past 30 years across different production methods, herd sizes and countries. On the other hand, individual farms and individual cows within a farm succeed in simultaneously achieving high performance, low prevalence and high profitability, while others cannot cope with these challenges. Differences in milk ...
Dissertation
Drivers for Fostering Agroforestry Systems in Temperate and Mediterranean Climates: Past, Present, and Future
(2024)
Traditional multifunctional agroforestry landscapes provide not only food but also support biodiversity and provide a multitude of ecosystem services. However, such landscapes have been frequently lost in the last decades. Given the multiple global challenges that have emerged from an industrial model of agriculture, agroforestry as a concept based on multifunctionality is increasingly regarded as key for sustainable food production systems of the future. To guide future land management and policies, past land-use ...
Bachelorarbeit
Bewertung der Anwendbarkeit von Single-Well Push-Pull Tracer-tests zur Bestimmung von Porosität und Dispersivität bei geringen hydraulischen Gradienten und in Brunnen mit großem Durchmesser
(2024)
Diese Arbeit beschäftigt sich konkret mit der Fragestellung, ob und inwieweit der Single-Well Push-Pull Tracertest als Methode für die Herleitung der Porosität und Dispersivität eines Grundwasser-leiters anwendbar ist, wenn nur ein sehr niedriger hydraulischer Gradient und dagegen jedoch ein großes Bohrlochvolumen vorausgesetzt sind.
Leap & Kaplan (1988) entwickelten eine analytische Methode, um die Fließgeschwindigkeit des Grundwassers mithilfe eines Single-Well Push-Pull Tracertests zu ermitteln. Hall et al. (1991) ...
Aufsatz
Performance of pacu (Colossoma macropomum) fed varying dietary inclusion levels of fish visceral and duckweed (Lemna minor) as replacement for fish and soybean meals
(2024-01-23)
The performance of Colossoma macropomum subjected to a six-month feeding trial using duckweed (Lemna minor) and fish visceral as partial replacements for soybean meal and fishmeal respectively was evaluated in this study. A total of one thousand five hundred (1500) nearly same sizes (average size 45 g) juveniles of C. macropomum were sourced from the nearby research man-made lake and subjected to proper acclimatisation for two weeks prior to the commencement of the feeding trial. One hundred (100) juveniles per ...
Aufsatz
Influence of ethylene oxide and gamma irradiation sterilization processes on the degradation behaviour of poly(lactic acid) (PLA) in the course of artificially accelerated aging
(2024-02-10)
To promote the application of bio-based materials in the field of medical technology, it is essential to conduct additional research, focusing on their long-term performance after sterilization. For this purpose, the study examines the aging behaviour of three poly(lactic-acid) (PLA) materials, sterilized with either ethylene oxide or gamma irradiation, over a two years aging period, in accordance with ASTM F1980-21. During these investigations, a direct correlation between moisture absorption and degradation progression ...
Aufsatz
Effect of different diets containing varying inclusion levels of Moringa oleifera leaf meal on growth, mineral composition and meat quality of the edible land snails Archachatina marginata and Achatina fulica
(2024-02-25)
This study examined the effect of different dietary inclusion levels of Moringa oleifera leaf meal on growth, haemolymph mineral composition and meat quality of Archachatina marginata and Achatina fulica. A total of one hundred and forty four (144) juvenile snails of A. marginata= 72 and A. fulica= 72, were used for the study. Eighteen (18) snails of each species were subjected to four dietary treatments (0%, 10%, 15% and 20%) of M. oleifera leaf meal in three replicates of six (6) snails per replicate over a period ...