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Prediction of gravity quantities values based on the terrestrial measurements and digital elevation model
Letko, Ivan ; Doudová, Lenka (referee) ; Machotka, Radovan (advisor)
The main objective of this master thesis is random equipartition concentration of measured gravimetric points in the area of interest pursuant by digital terrain model. Remove-Compute-Restore method was used for this purpose. In this thesis normal acceleration of gravity, topographic effect and Faye anomaly were subtracted from measured gravity. The result is Bouguer anomaly with general topographic effect which is interpolated for concentration points. We obtained predicated values of gravity after the restoration of subtracted effects. The main result of the thesis is the map of real gravity and precision evaluation of used method. Furthermore, the reductions of gravity, interpolation methods in programme ArcGIS, Remove-Compute-Restore method and the term of digital terrain model are explained in the thesis.
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VR Innovative Game Demo in UE4
Doležal, Josef ; Chlubna, Tomáš (referee) ; Milet, Tomáš (advisor)
The task of this bachelor thesis is to create a demo application for virtual reality using Unreal engine 4. Main mechanics are gravity sfere, simulating custom gravity and mirror portals with an ability to teleport a player to a previous or any other destination. All prefabs are free to be used in another Unreal engine 4 projects.
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Tilt sensors
Hájek, Tomáš ; Caha, Luděk (referee) ; Beneš, Petr (advisor)
The topic of the Bachelor's thesis are MEMS sensors of inclination, which find their use inside integrated circuits, equipment of aerospace and automobile industry, but also in ordinary electrical appliance. The work serves the reader to build a grasp over production, usage, basic principles. Finally, it offers an overview of sensors to ease the orientation on the market. The design of the physical model, which can be used to prevent the sensor from apperance of mathematical errors, is tested in the practical part.
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Geological and gravimetric pattern of the Ethiopia
Kuznetsova, Alevtina ; Valenta, Jan (advisor) ; Martínek, Karel (referee)
From a geological point of view, Ethiopia is a unique country where active tectonics displays can be studied, in the context of extensive East African Rift System (EARS) evolution, where the Main Ethiopian Rift (MER) is a part. The Main Ethiopian Rift (MER) is typical continental rift structure spread between the African, Somali, and Arabian lithospheric plates stretching over 6,000 kilometres from Syria to central Mozambique. This study of the gravity pattern in Ethiopia reveals significant crustal thinning in the Main Ethiopian Rift and Northern Afar regions. In the southern Afar, the earth's crust has a slightly higher thickness and, moreover, probably contains a significant proportion of the continental crust. The understanding of crustal thinning in the context of active rifting is essential to predict future geodynamic events in that region, which is crucial for the sustainable life of a rapidly expanding population and the necessary construction of infrastructure. This work provides an analysis and re-interpretation of archival gravity data collected from land surface surveys and airborne gravity studies (archive of Geological Survey of Ethiopia) in conjunction with available geological and structural data to evaluate overall gravimetric pattern of Ethiopia and determine main geological...
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Numerická předpěťová modální analýza kmene
Skokan, Vojtěch
This work is investigating the effect of prestress on the results of the numerical modal analysis of tree stem and the effects of the degree of simplification of the geometry of the numerical model on the values of natural frequencies and modes of natural oscillation. The work aims to create credible numerical models of trunks and to use prestress to induce such a change in the diameter of the trunk that occurs in trees during the diumal cycle, thus simulating the transpiration stress in the trunk. During the work, three different methods of inducing prestress in the trunk are investigated and their impact on the values of the observed frequencies of strain models is assessed. In addition to artificial prestress, the work also assesses the impacts of the co-effect of gravity on the values of natural frequencies. This work is one of the first attempts to investigate the effect of mechanical stress caused by the transpiration flow using numerical simulation and can thus lay the foundation for future research in this field.
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Geophysical and gravimetric pattern of Ethiopia, construction, and verification of a new gravity map of Ethiopia
Kuznetsova, Alevtina ; Valenta, Jan (advisor) ; Martínek, Karel (referee)
From a geological point of view, Ethiopia is a unique country where active tectonics displays can be studied, in the context of extensive East African Rift System (EARS) evolution, where the Main Ethiopian Rift (MER) is a part. The Main Ethiopian Rift (MER) is typical continental rift structure spread between the African, Somali, and Arabian lithospheric plates stretching over 6,000 kilometres from Syria to central Mozambique. This study of the gravity pattern in Ethiopia reveals significant crustal thinning in the Main Ethiopian Rift and Northern Afar regions. In the southern Afar, the earth's crust has a slightly higher thickness and, moreover, probably contains a significant proportion of the continental crust. The understanding of crustal thinning in the context of active rifting is essential to predict future geodynamic events in that region, which is crucial for the sustainable life of a rapidly expanding population and the necessary construction of infrastructure. This work provides an analysis and re-interpretation of archival gravity data collected from land surface surveys and airborne gravity studies (archive of Geological Survey of Ethiopia) in conjunction with available geological and structural data to evaluate overall gravimetric pattern of Ethiopia and determine main geological...
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Visualization of root apoplastic pH in plants
Wernerová, Daša ; Fendrych, Matyáš (advisor) ; Paris, Nadine (referee)
Plant oriented movements, or tropisms allow the plant to actively respond to environmental stimuli to get more light, better access to nutrients and to grow roots deeper into the soil. Gravitropism drives the growth of roots along the gravity vector. Perception of gravity is triggered by the sedimentation of statoliths in columella root cap, but the exact signalling pathway behind this process is not known. Perception of gravity results in an unequal redistribution of the phytohormone auxin in the outer cell layers which leads to different rate of growth on the root's upper and lower side and bending of the root. The changes in auxin redistribution are accompanied by changes in apoplastic pH. Knowing an exact pattern of these pH changes could shed light on the mechanisms laying behind the gravitropic response pathway. While microelectrodes can be used to measure pH precisely, they are not suitable for the long-term imaging of growing roots. In the past few years, several pH sensitive dyes and genetically encoded sensors emerged. These can be used for long-term live in vivo imaging of pH changes in growing roots. In this thesis, I analysed the performance of several published pH sensitive genetically encoded sensors and available dyes in the roots of Arabidopsis thaliana. I observed that dyes varied...
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The mathematical theory of perturbations in cosmology
Novák, Jan ; Pravda, Vojtěch (advisor) ; Chopovsky, A. (referee) ; Scholtz, Martin (referee)
We deal with cosmological perturbation theory in my work. We investigate General Theory of Relativity in Higher Dimensions in the Chapter 1. I mention GHP-formalism and algebraical classification of spacetimes. I use spinors to show that spacetimes of dimension 4 are special. I discuss also Kundt spacetimes, which are interesting for perturbation theory of black holes. I work with perturbations of FLRW ST's in GHP formalism in Chapter 2, which we want to use in Cosmological Inflation. The final part of my thesis is connected with scalar perturbations in f(R)-cosmologies, that can be used for explaining accelerated expansion in the last 5 billion years. I investigate the Universe at the scales of 150 Mpc, where I could not use the hydrodynamical approach. Thus I work with the generalization of the Landau's mechanical approach. I need quasi-static approximation for getting the potentials Φ and Ψ, since the equations are too complicated for direct integration. I plan to use the result also for numerical simulation of motions of dwarf galaxies in these potentials. Powered by TCPDF (www.tcpdf.org)
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Galaxy interactions: dark matter vs. Modified Newtonian dynamics (MOND)
Bílek, Michal ; Jungwiert, Bruno (advisor) ; Kroupa, Pavel (referee) ; Stuchlík, Zdeněk (referee)
MOND is an observational rule for predicting the acceleration of stars and galaxies from the distribution of the visible matter. It possibly stems from a new law of physics. I list the theoretical aspects of MOND, its achievements and problems. MOND has been tested mainly in disc galaxies so far. Its tests in elliptical galaxies are rare because the MOND effects are small for them in the parts observable by the conventional methods. In the thesis, I explain the methods and ideas I developed for testing MOND in the ellipticals using stellar shells. Moreover, the shells enable us to test MOND for stars in radial orbits for the first time. The shells are results of galactic interactions. I discuss the shell formation mechanisms and summarize the findings from shell observations and simulations.
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Selected gravitational effects in the Universe
Franc, Tomáš
Title: Selected gravitational effects in the Universe Author: Mgr. Tomáš Franc Department: Astronomical Institute of Charles University Supervisor: doc. RNDr. Marek Wolf, CSc., Astronomical Institute of Charles University Abstract: In this Thesis we have given an overview of tidal phenomena with their explanations and also explained the gravitational assist with examples of its use. We have created many pictures and 17 animations for better understanding of these topics. This part of the Thesis is focused on high school students and their teachers, it can be used by teachers for their inspiration for lessons, or students and more generally people interested in these topics can read this part as a study text. The main part of the Thesis is the result of research conducted on 13 high schools in the Czech Republic. 800 students took part in the research; its purpose was to find out students' knowledge of tidal phenomena and the gravitational assist. The research was carried out in the form of questionnaires. Keywords: gravity, tidal phenomena, gravitational assist, pedagogical research
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