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Exact spacetimes and their physical properties
Veselý, Jiří ; Žofka, Martin (advisor) ; Hennigar, Robie (referee) ; Tahamtan, Tayebeh (referee)
Motivated by our desire to find generalizations of the Bonnor-Melvin spacetime, the thesis investigates seven static, cylindrically-symmetric and electrovacuum exact solutions to the Einstein-Maxwell equations. They contain a magnetic field and six of them also include the cosmological constant. After discussing some of the methods we use during our investigation, we present the basic properties of the spacetimes, and for each of them we also study charged test particle motion and their admissible shell sources composed of particle streams. We also perform numerical computations to determine whether the equations admit more general solutions than the exact ones we derived. 1
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Selected exact spacetimes in Einstein's gravity
Ryzner, Jiří ; Žofka, Martin (advisor) ; McNutt, David D. (referee) ; Pravdová, Alena (referee)
The aim of this thesis is to construct exact, axially symmetric solutions of Einstein- Maxwell(-dilaton) equations, which possess a discrete translational symmetry along an axis. We present two possible approaches to their construction. The first one is to solve Einstein-Maxwell equations, the second one relies on a dimensional reduction from a higher dimension. We examine the geometry of the solutions, their horizons and singu- larities, motions of charged test particles and compare them. 1
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Characterization of soil units within the forest site complexes in ČLA Trutnov
Kejklíčková, Iva ; Penížek, Vít (advisor) ; Ulbrichová, Iva (referee)
The objective of this master thesis is the evaluation of the most frequent forest soil types in forest district of the Czech Forestry Academy (ČLA) Trutnov. The ČLA forest district covers area 670,41 ha. Soil survey and phytocenose analysis was performed on eight most frequent forest site complexes (FSCs) within the district. This work is focused on the phytocenose analysis in the particular FSCs, soil types determination physical and chemical soil properties on the particular FSCs. Additionlly conditions and possible differencies between coniferous and deciduous stands were investigated on three forest site complexes. According to the results of measurement when evaluating the relationship between the forest and soil type it shows that in given natural conditions of the forest district of the Czech Forestry Academy Trutnov there are FSCs corresponding with the given conditions on the forest grounds. Particular FSCs occur in the direct dependence on natural conditions and their soil profiles correspond with pedogenesis on the particular sites. The hypothesis was confirmed, that a long term vegetation influence characterized by FSCs has substantially influence over soil environment and the other way round. The interaction between the phytocenose and soil environment was found on all monitored sites. Different fytocenosis composition of broadleve and coniferours forest stands influences the chemical and physical properties, humus forms and some of the morphological properties of soil profiles with different intensity in all three detailly studied FSCs. However, this influence was less considerable, when compared with assumptions.
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