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Dissertation
Combining crop growth models with the Precision Agriculture concept of yield gap analysis to evaluate yield limiting and reducing factors
(2022)
The agricultural sector is considered as one of the main elements of a “functional” society and its welfare for providing means to fulfil the most basic human need for food. In the past, an improved overall welfare of developed countries was directly related to early investment in conventional farming machinery parallel to the industrial development. With the expected future population increase and climate change, farm yield gaps are expected to increase and become more volatile. The awareness of negative externalities ...
Dissertation
Designing Breeding Programs For Improving Milk Yield Performance Of Indigenous Genous Dairy Cattle In Sudan
(2022)
The overall aim of the present study was to design appropriate breeding programs for the sustainable improvement of Butana cattle in Sudan. Four studies were conducted, beginning with a comprehensive review of literature on indigenous dairy cattle breeding strategies in sub-Saharan Africa with a focus on the factors that contribute to their success or failure. It showed that crossbreeding of indigenous breeds with exotic breeds has been widely used for genetic improvement, but it largely failed under low-input ...
Dissertation
Taking a Closer Look at the Desirability of Desirable Difficulties - Additionally Focusing on Required Prerequisites, Negative Side-Effects, and Negative Consequences
(2022)
As the title of my dissertation already indicates, the main purpose of the following work was to take a closer, more thorough, and encompassing look at the desirability of desirable difficulties. The term desirable difficulties thereby subsumes varying types of difficult, demanding, and challenging learning strategies—like the application of (learning/practice) tests and generation tasks: Working on and successfully solving those difficult tasks requires more (cognitive) effort compared to working on easier learning ...
Dissertation
Validation of a generalized model for the description of polycrystalline exchange-biased magnetic thin films
(2022)
Applications based on nano- and microscaled systems have become indispensable in many aspects in everyday life, industry, research and medicine. In this regard, thin film technology plays a crucial role with the physical properties of solids changing significantly when they are reduced to thin layers with thicknesses in the nanometer range. In this regime, a solid’s microstructure as well as boundary and surface effects start to dominate. A prominent example is the exchange bias effect, which results due to the ...
Dissertation
Entwicklung einer vereinfachten europaweit anwendbaren Methodik zur Festlegung von Effizienzanforderungen an Wärmerückgewinnungssysteme in der Raumlufttechnik für Nicht-Wohngebäude auf der Grundlage mehrdimensionaler Optimierungsberechnungen
(2022)
Die vorliegende Dissertation beschäftigt sich mit der Anpassung der EU-Verordnung 1253/2014, welche die Effizienzkriterien an die WRG von RLT-Geräten in NWG festlegt. Die Verordnung definiert die Anforderungen als starre Grenzwerte, die vom Süden bis zum Norden Europas gelten ohne den jeweiligen Standort oder die Gebäudenutzung zu berücksichtigen. Gemäß den Referenzwerten der aktuellen Verordnung wurde eine Verschärfung des Anforderungsniveaus diskutiert, wobei auch hier zunächst starre Grenzwerte geplant waren. Der ...
Dissertation
Zusammenhang der Nutzungshäufigkeit mit der Wirksamkeit eines angeleiteten Online-Selbsthilfeprogramms bei depressiven Patienten
(2022)
Zusammenhang der Nutzungshäufigkeit mit der Wirksamkeit eines angeleiteten Online-Selbsthilfeprogramms bei depressiven Patienten:
Die Deprexis-Studie, die Basis meiner Arbeit ist, hat gezeigt, dass eine webbasierte Selbsthilfe als Ergänzung zur multimodalen stationären psychotherapeutischen Behandlung den Verlauf der depressiven Symptome verringern kann und so die Wirkung der stationären Psychotherapie durch die Integration einer zusätzlichen Online-Intervention verbessert. Eine Stichprobe von 115 Patient*Innen, ...
Dissertation
Praktische Anwendung von aktiver Vormagnetisierung in transformatorlosen DC/DC-Konvertern
(2022)
Magnetic devices are used in almost every power electronic system. Therefore, their purpose and with that their requirements can vary in a wide range. The consequence is a large number of options regarding the priority of optimisation. In this work, the focus is on reducing the volume or weight of inductors in transformerless DC-DC converters. Active prmeagnetization is choosed as an optimisation approach. The technique enables an operation of the DC-DC-converter in the Triangular Current Mode (TCM), whereby ...
Dissertation
A Multi-Perspective Investigation of the Innovation Process: Dynamics, Regulation, and Integration of Concepts
(2021)
This dissertation provides insight into how individuals and teams address the complex and dynamic nature of innovation processes. Focusing on affect and self-regulation, the dissertation investigates how and why regulation efforts of individuals and teams may be beneficial for both innovative activities (i.e., idea generation and implementation) and innovative strategies (i.e., exploration and exploitation). Further, it addresses the issue of conceptual variety in innovation research and examines to what extent ...
Dissertation
Untersuchung von Gussporen in einer Aluminium-Gusslegierung mit der Computertomographie
(2022-04)
In dieser Arbeit wird das Schädigungsverhalten einer Aluminium-Gusslegierung anhand von zweidimensionalen und dreidimensionalen Verfahren untersucht. Dabei liegt das Hauptaugenmerk auf innenliegenden Gussdefekten wie Gas- und Schrumpfungsporen. Die Schädigungsentwicklung unter schwingender Belastung, sowie der Einfluss auf die Mikrostruktur und die mechanischen Eigenschaften sowie die Wechselwirkung verschiedener Gussdefekte werden dabei untersucht. Insbesondere wird der beim Versagensverhalten entscheidende Einfluss ...
Dissertation
Sustainability of traditional cocoa agroforests in Ghana
(2022)
Cocoa (Theobroma cacao L.) is an important agricultural commodity that is important to the economies of many countries in the world. Due to cocoa’s dependence on fertile forests soils, its production is a major cause of deforestation and soil degradation in producing countries. When grown in agroforestry systems it can conserve biodiversity, sequester carbon (C), and maintain soil fertility. There are many cocoa agroforests which are managed without synthetic agrochemicals. Because organic cocoa certification is now ...