Suche
Anzeige der Dokumente 191-200 von 253
Dissertation
Strukturelle und magnetische Veränderungen in Schichtsystemen mit Grenzflächenaustauschkopplung nach dem Beschuss mit keV-Heliumionen
(2018-03-21)
Magnetische Schichtsysteme mit Grenzflächenaustauschkopplung sind in ihrer Art dahingehend einzigartig, dass sie unter bestimmten Bedingungen nur eine einzige präferierte Orientierung der remanenten Magnetisierung aufweisen, das heißt, dass die Ausrichtung ihrer Magnetisierung in Abwesenheit eines externen Magnetfeldes eindeutig definiert ist. Hervorgerufen wird dies durch die Austauschkopplung einer dünnen ferromagnetischen mit einer dünnen antiferromagnetischen Schicht, wodurch der sogenannte exchange-bias-Effekt ...
Dissertation
Laser amplification in excited dielectrics
(2018-02-12)
Today, laser processing of dielectric materials with ultrashort, femtosecond laser pulses finds a great variety of applications. While ablation, cutting or welding of different types of glasses are widespread and popular examples, nanostructuring of transparent crystals or optoporating cells is part of more recent scientific studies. Although the material systems seem to be very different, their interaction with visible and infrared wavelengths is very similar: the light is simply transmitted. This changes drastically ...
Dissertation
Theory of Vesicle Motion and Interpretation of Electrophysiological Experiments in Chromaffin Cells, Hippocampal Neurons and Neuromuscular Junctions
(2018-07-16)
Communication among secretory cells, neurons and other related cells is accompanied by a
process called exocytosis, which consists in the release of neurotransmitters into the intercellular space. The neurotransmitter molecules are transported inside vesicles, which move
towards the cell membrane. Once at an active site of the membrane, vesicles can undergo
fusion with the membrane. As a result of fusion, a pore in the membrane is produced, through
which neurotransmitter molecules leave the cell. Exocytosis is ...
Preprint
On the existence of symmetric minimizers
(2018-01-23)
In this note we revisit a less known symmetrization method for functions with respect to a topological group, which we call G-averaging. We note that, although quite non-technical in nature, this method yields G-invariant minimizers of functionals satisfying some relaxed convexity properties. We give an abstract theorem and show how it can be applied to the p-Laplace and polyharmonic Poisson problem in order to construct symmetric solutions. We also pose some open problems and explore further possibilities where the ...
Dissertation
Influence of Calcium Aluminate Cement and Ground Granulated Blast Furnace Slag on the Synthesis of Rice Husk Ash-Based Geopolymer Mortars
(2018-02-26)
The manufacture of Portland cement is energy intensive and is associated with carbon dioxide emission of approximately 7% of total global emission. The process also produces pollution in the forms of dust, noise, and vibration with operating machinery during blasting in quarries. Geopolymer material is formed through the reaction of silica and alumina oxides with alkali activator and has appeared as a viable alternative to the Portland cement in the construction field due to good properties such as high compressive, ...
Buch
Statik und Einflussfunktionen - vom modernen Standpunkt aus
(2018-02)
Die Genauigkeit einer FE Lösung hängt, wie wir heute wissen, von der Genauigkeit der Einflussfunktionen ab, die sich auf dem Netz generieren lassen. Mit diesem Wandel in dem Verständnis der finiten Elemente haben Einflussfunktionen plötzlich ein großes Gewicht in der Statik bekommen, sind sie vom Rand in den Mittelpunkt gerückt. Diese Verschiebung der Schwerpunkte war der Auslöser für dieses Buch, das hier in der 2. deutschen Auflage vorliegt. Die englische Ausgabe ist 2017 im Springer-Verlag erschienen.
Die ...
Dissertation
Climate Change Impact Assessment of Basin-scale Water Allocation and Management in the Karkheh River Basin, Iran
(2018-09-21)
Hydrological research is intended to improve our understanding of hydrologic processes, the role of hydrological systems in providing water for ecosystems and society, and of the water cycle in the functioning of the earth system. The proper understanding of the hydrology of arid and semi-arid regions is becoming increasingly important, due to diminishing projections of water resource availability in response to global environmental changes. The main objective of this thesis study is to investigate the development ...
Dissertation
HACCP in Germany and Lebanon
(2018-10-22)
Food borne outbreaks have been on the rise in Lebanon and in Germany in recent years. Food safety systems have been developed over a period of years starting from HACCP which was established in the 1950’s unto the European directive 93/43/EEC established in 1993, to directive (EC) No 178/2002 until today in order to prevent and control hazards in the different food safety fields. Such systems which started with HACCP (hazard analysis and critical control point) and was later integrated into private systems such as ...
Dissertation
Nachhaltige Nutzung biogener Haushaltsabfälle durch die aerobe Behandlung von getrennt gesammelten biogenen Abfallstoffen und die Anwendung von Kompost in der Landwirtschaft im Südkaukasus
(2018-02-06)
Nachhaltige Nutzung biogener Haushaltsabfälle durch die aerobe Behandlung von getrennt gesammelten biogenen Abfallstoffen und die Anwendung von Kompost in der Landwirtschaft im Südkaukasus
Dissertation: Nikolas Zöller, im Fachbereich 11, Ökologische Agrarwissenschaften der Universität Kassel Zusammen mit den Projektpartnern (Armenian National Agrarian University und Agricultural Agrarian University of Georgia) wurden in ausgewählten Kleinstädten mit unterschiedlicher Siedlungsstruktur ...
Aufsatz
Linking sustainable diets to the concept of food system sustainability
(Section Specialized Partnerships in Sustainable Food Systems and Food Sovereignty at the University of Kassel, Germany and Federation of German Scientists (VDW), 2018-10-09)
Based on insights from an ongoing research project on food sustainability, we argue that discussing sustainable diets in isolation from food systems poses risks. Among these risks are making healthy diets exclusive, or ignoring externalities like biodiversity loss, land concentration, and encroachment on commons. Case studies from Bolivia and Kenya show how marked shifts from traditional to more uniform diets rich in sugar, salt, and fatty acids come with a radical transformation of food systems. Systems formerly ...