Suche
Anzeige der Dokumente 1-10 von 40
Aufsatz
Optical amplification and stability of spiroquaterphenyl compounds and blends
(2015)
In this contribution, we present a systematic investigation on a series of piroquaterphenyl compounds optimised for solid state lasing in the near ultraviolet (UV). Amplified spontaneous emission (ASE) thresholds in the order of 1 μJ/cm2 are obtained in neat (undiluted) films and blends, with emission peaks at 390 1 nm for unsubstituted and meta-substituted quaterphenyls and 400 4 nm for para-ether substituted quaterphenyls. Mixing with a transparent matrix retains a low threshold, shifts the emission to lower ...
Dissertation
Land tenure in a changing climate
(2023)
Climate change and extreme weather have far-reaching impacts on agriculture. They do not only affect agricultural production, but also fundamental assets that shape agricultural livelihoods. In this dissertation, I study the relation of weather and climate with agricultural land tenure in low- and middle-income countries. Secure access to land is of vital importance for farmers, but insecure tenure is a reality for millions of farmers around the globe. They are unsure whether they will be able to continue farming ...
Dissertation
Neo-institutionalism and business sustainability in emerging economies
(2022)
This dissertation deals with the institutional environment surrounding the private sector in the various emerging markets and developing economies (EMDEs) worldwide where most of the global population lives. Its primary purpose is to identify and combine theoretical aspects of new (sociological) institutionalism/neo-institutionalism to better understand the role of institutional environments in shaping business impacts on sustainable development. Institutions shape the behaviour of individuals as well as entire groups ...
Dissertation
Darstellung, Eigenschaften und Reaktivität phosphorreicher Ferrocenophane
(2022-05)
Im Rahmen dieser Arbeit wurde ein präparativer Zugang zu phosphorreichen Ferrocenophanen entwickelt, die Substituenten mit variierenden sterischen und elektronischen Eigenschaften tra-gen und die Reaktivität dieser gegenüber Elektrophilen untersucht.
Die Reaktivitätsuntersuchungen des als Modellverbindung ausgewählten Diphospha-[2]fer-rocenophans L6a gegenüber Elektrophilen haben gezeigt, dass sowohl ein als auch beide Phos-phoratome selektiv, durch stöchiometrische Kontrolle mit Monoboran oder unterschiedlichen ...
Dissertation
Industry 4.0-driven additive manufacturing for operations in the circular economy
(2023-06)
This dissertation focuses on exploring how key elements of Industry 4.0 (I4.0), such as additive manufacturing (AM) and quantitative techniques/simulation, instigate the operations of an organisation towards the circular economy (CE). AM represents the technological foundation of future manufacturing which efficiently utilises materials avoiding unnecessary waste. Further, it could positively impact the transition towards CE by addressing issues related to the operations and supply chains while positively influencing ...
Dissertation
Managing Collaboration in Circular Supply Chains
(2023-05)
The dissertation focuses on understanding the application of the circular economy (CE) concept to the supply chain management (SCM) domain as ‘circular supply chains’ (CSCs) and the role of collaboration in this application. While CE is an emerging approach for sustainable production and consumption, its application in the SCM domain as CSCs could assist in improving the overall sustainable performance. Collaboration with internal and external partners is crucial to achieve this improvement. Hence, with the aim to ...
Dissertation
Herausforderungen bei der Analyse von Unterrichtsqualität und deren Wirkungen auf Lernende
(2023-07)
Die empirische Unterrichtsforschung stellt Forschende vor zahlreiche Herausforderungen. Eine besondere Herausforderung besteht darin, dass wissenschaftliche Ergebnisse in hohem Maße von den Entscheidungen der Forschenden im Forschungsprozess abhängen – ein informiertes Vorgehen ist für jeden Schritt guter wissenschaftlicher Forschung fundamental. Ziel der kumulativen Dissertation ist es daher, aus einer Metaperspektive theoretisch-konzeptionelle Grundlagen und forschungsmethodische Fragen der Unterrichtsforschung zu ...
Aufsatz
Beam powder bed fusion for direct microstructure design – In-depth analysis of prospects and limitations of the multi spot scanning strategy
(2023)
The electron beam powder bed fusion process generally results in a strong 〈001〉 texture alongside the build direction for Inconel 718. This is a result of prevailing high thermal gradients between the melted surface and the solid material. However, based on specific beam movement patterns, the solidification behaviour can be altered towards an equiaxed, isotropic microstructure. The present study focuses on the “multi spot scanning” strategy directly provided by the machine manufacturer. The operation mode of the ...
Dissertation
The anatomy of velvet worms (Onychophora) as revealed by a multimethodological approach and three-dimensional reconstructions
(2024)
Onychophorans, or velvet worms, comprise a small group of worm-like, multi-legged terrestrial invertebrates. Since their discovery in 1826, these organisms have been investigated from different perspectives, particularly in the field of morphology—a discipline that provides the basis for functional and evolutionary inferences. Onychophorans are currently classified within Ecdysozoa (moulting animals) and form together with Tardigrada (water bears) and Arthropoda a clade named Panarthropoda. Therefore, onychophorans ...
Dissertation
City Development Regimes in-the-Making. Phronetic Analysis of Governance, Networks and Power in Cairo, 2011-2022
(2024)
Since the revolutionary uprising of January 2011, Cairo’s inner-city neighbourhoods have undergone rapid spatial transformations. Over the last decade, numerous old housing buildings have been replaced by modern ones, leading to the displacement of residents to the desert cities or newly-constructed neighbourhoods outside the city centre. The most remarkable transformations occurred since early 2018. Notably, these changes have been characterised by a fast implementation rate and a lack of community resistance to ...