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Dissertation
Development and assessment of volume resolving velocimetry for turbomachinery test facilities
(Deutsches Zentrum für Luft- und Raumfahrt DLR, 2017-12-21)
The present thesis assesses the applicability of volume resolving velocimetry
for turbo machinery test facilities. Tomographic particle image velocimetry has been implemented in a transonic cascade wind tunnel. Assessment is based on 3D-3C measurements of the passage vortex in an axial compressor cascade at subsonic inflow (Ma1=0.6). Results show broad consistency with stereoscopic PIV with improved depth resolution. A novel Fast Multiplicative Algebraic Reconstruction Technique (FMART) enables signi cantly faster ...
Dissertation
Design and Numerical Simulation of Dielectric Photonic Crystal Devices and Investigation of an Optical Characterization Method
(2017-11-09)
In this research work, dielectric photonic crystal (PhC) structures based on low refractive index slab waveguide are investigated. These two-dimensional slab waveguide PhC structures work on the principle of guided-mode resonance and find their application in optical filters operated in the near-infrared range. The design and numerical simulation of the presented PhCs are carried out using finite-difference time-domain (FDTD) method. The dielectric materials used in the presented structures are zirconium dioxide/niobium ...
Dissertation
Residual-Layer-Free 3D Nanoimprinting using Novel Hybrid Soft Templates
(2017-08-23)
Hybrid 3D soft templates are designed and evaluated for residual layer free 3D imprinting in UV-Substrate Conformal Imprint Lithography (SCIL). 3D imprinting usually results in laterally varying residual layers, which cannot be removed by conventional etching processes in a satisfactory manner. The hybrid templates introduced in this thesis are hybrid in a way that their template protrusions are enclosed with a UV-blocking metal layer, by this means selective UV curing of the resist material is attainable. Hence, the ...
Dissertation
Development, Evaluation and Optimization of Fabrication Processes for Daylight Guiding Systems Based on Micromirror Arrays
(2017-01-11)
In this work, fabrication processes for daylight guiding systems based on micromirror arrays are developed, evaluated and optimized.Two different approaches are used: At first, nanoimprint lithography is used to fabricate large area micromirrors by means of Substrate Conformal Imprint Lithography (SCIL).Secondly,a new lithography technique is developed using a novel bi-layered photomask to fabricate large area micromirror arrays. The experimental results showing a reproducible stable process, high yield, and is ...
Dissertation
Optical Sensor Array based Nanospectrometer: Fabrication of high resolution 3D NanoImprint master templates and bonding of Fabry-Pérot filter array onto photodetector array
(2017-05-11)
In the field of optical spectroscopy, spectrometers are high resolution optical sensors that have emerged as a platform for a wide range of application fields. Commercially available spectrometers are bulky and expensive. Hence, this limits its integration into modern mobile and wearable devices. To overcome this limitation, miniaturization of spectrometers is an interesting target for a wide range of emerging applications. The most attractive concept of fabricating miniaturized spectrometers is the Fabry-Pérot filter ...
Aufsatz
Construction and Use of a Simple Index of Urbanisation in the Rural–Urban Interface of Bangalore, India
(2017-11-21)
Urbanisation is a global trend rapidly transforming the biophysical and socioeconomic structures of metropolitan areas. To better understand (and perhaps control) these processes, more interdisciplinary research must be dedicated to the rural–urban interface. This also calls for a common reference system describing intermediate stages along a rural–urban gradient. The present paper constructs a simple index of urbanisation for villages in the Greater Bangalore Area, using GIS analysis of satellite images, and combining ...
Aufsatz
Effect of Sowing Method and Weed Control on the Performance of Maize (Zea mays L.) Intercropped with Climbing Beans (Phaseolus vulgaris L.)
(2017-06-23)
Maize is grown on a large area in Germany and there is a growing concern in society about negative environmental effects related to this. The objective of the study was to test the performance of mixtures of maize and climbing beans as an alternative to monocropped maize under different site and management conditions. The effects of sowing density of maize and beans as well as the sowing time of beans on total dry matter (DM) yield and bean DM contribution to the total yield were investigated. Further, various ...
Aufsatz
Nutritional Comparison of White and Red Coccinia Abyssinica (Lam.) Cong. Accessions: An Under-Utilised Edible Tuber of the Ethiopian Highlands
(2017-08-22)
Anchote (Coccinia abyssinica) is an indigenous tuber crop of the Ethiopian Highlands. It is popular in the western Oromia Region of the country. Apart from food, the crop is also used in traditional medicine. Anchote tubers possess two variations in its tissue colour, red and white. In this study, a small market survey and a nutritional comparison of red and white anchote were conducted. White tissue anchote seems to be more popular, due to its soft texture and ease of cooking. However, the red variant was considered ...
Aufsatz
Preparation and Molecular Structure of a Cyclopentyl-Substituted Cage Hexasilsesquioxane T6 (T = cyclopentyl-SiO1.5) Starting from the Corresponding Silanetriol
(2017-10-04)
Cyclopentyl substituted silanetriol can be prepared and isolated. Its condensation yields the corresponding disiloxanetetrol as a primary condensation product. Further condensation leads to the hexameric polyhedral silsesquioxane cage T6. The latter has been mentioned in the literature before however, lacking structural data. All compounds have been characterized with multinuclear NMR spectroscopy and, in addition, the molecular structures have been determined in the case of the disiloxanetetrol and the hexasilsesquioxane ...
Verschiedenartige Texte
Lurchi
(KinderundJugendmedien.de – Wissenschaftliches Internetportal für Kindermedien und Jugendmedien, 2017-08-15)
Der vorliegende Beitrag beleuchtet Lurchis Abenteuer im Medienverbund aus Produktions- wie Rezeptionsperspektive und legt dabei ein besonderes Augenmerk auf die Sammelbände, die die Einzelhefte unter dem Titel Lurchis Abenteuer zusammenfassen. Methodisch ist dieser Artikel einer comictheoretischen (Narratologie, Multimodalität etc.) sowie literatur- (Lyrikanalyse, Handlungsschemata, Transtextualität) und kulturwissenschaftlichen Ausrichtung (Human-Animal und Gender Studies) bei gleichzeitiger Berücksichtigung der ...