|
|
Evolution of interplanetary coronal mass ejections
Lynnyk, Andrii ; Vandas, Marek (advisor) ; Přech, Lubomír (referee) ; Rušín, Vojtěch (referee)
Title: Evolution of Interplanetary Coronal Mass Ejections Author: Andrii Lynnyk Department: Department of Surface and Plasma Science Supervisor: RNDr. Marek Vandas, DrSc. e-mail address: vandas@ig.cas.cz Abstract: This thesis deals with deformation of the Interplanetary Coronal Mass Ejections (ICMEs) and their sub-class Magnetic Clouds (MCs) during their propagation in the Solar Wind (SW). The statistical study of the expanded MCs has shown that expansion greatly affects the MC internal magnetic field. We had shown that this influence is more clear for the MCs observed close to their axes. The study of the stand-off shock distance in front of the supersonic ICME confirms a smooth deformation of the ICMEs along their path from the Sun into interplanetary space. We observed that this deformation is increasing with the velocity of the ICME. This study also confirmed the difference in sheaths that are created in front of expanding and non-expanding ICMEs. We found that velocity distribution inside the MC is not uniform and it has large fluctuations. We found that the MC cross-section is usually strongly deformed. Keywords: interplanetary coronal mass ejection, magnetic cloud, magnetosheath, flux rope, magnetic field, shock, fitting
|
|
|
Dynamics of the bow shock and magnetopause
Jelínek, Karel ; Němeček, Zdeněk (advisor) ; Kudela, Karel (referee) ; Vandas, Marek (referee)
viii Title: Dynamics of the bow shock and magnetopause Author: Karel Jelínek Department: Department of Surface and Plasma Science Supervisor: Prof. RNDr. Zdeněk Němeček, DrSc. Department of Surface and Plasma Science e-mail address: zdenek.nemecek@mff.cuni.cz Abstract: The interplanetary space is a unique laboratory which allows us to dis- cover (i) a behavior of the plasma under different conditions, (ii) origin of its insta- bilities, and (iii) its interaction with obstacles such as the Earth's magnetosphere. The present thesis analyzes the outer Earth's magnetosphere. The results are based on the in situ sensing by a variety of the spacecraft (e.g., IMP-8, INTERBALL-1, MAGION-4, Geotail, Cluster-II and Themis). The solar wind curently monitored by the WIND and ACE spacecraft near the La- grange point L1 affects by its dynamic pressure the Earth's magnetic field which acts as a counter-pressure and the boundary where these pressures are balanced is the magnetopause. Due to supersonic solar wind speed, the bow shock forms in front of the magnetopause and a region in between, where plasma flows around an obstacle is named the magnetosheath. The thesis contributes to a deaper understanding of the dependence of magnetopause and bow shock shapes and positions, especially, (1) on the orientation of the inter-...
|
|
|
ESWT in Achilles tendinopathy
Hojková, Lýdie ; Demeková, Júlia (advisor) ; Havlíčková, Michaela (referee)
Achilles tendinopathy is a painful condition formed by chronic overuse. Conservative treatement requires activity modification, heel lifts, arch supports, even immobilisation. There are often unsatisfactory results with it. The use of ESWT has recently been introduced in soft-tissue disorders including epicondylitis, plantar fasciitis, calcifitation of the shloulder and, as well, Achilles tendinopathy. The aim of the work was to introduce the effects of ESWT on soft tissues, types of generation and new posibilities in ESWT therapy in Achilles tendinopathy. Powered by TCPDF (www.tcpdf.org)
|
|
|
Fast Transient Phenomena in High Voltage
Vala, Martin ; Dohnal, Petr (referee) ; Krbal, Michal (advisor)
This work deals with research and description of the fast transients in high voltage technics. First part deals with division of fast transients and description of an impulse wave properties. Second part is focused on atmospheric overvoltage description and on direct and indirect lightning surge protection methods. Next, there are described the main characteristics and division of the surge protection devices in the work. In the next part, there are introduced some sort of high voltage generators, used for meassurement of impulse wave in a transmission line. In the last part there is stated an analysis of practical measurement of impulse weaves and surge arresters by using a Marx generator.
|
|
|
Stress-strain analysis of the thin wall structure subjected to impact load
Tatalák, Adam ; Peč, Michal (referee) ; Návrat, Tomáš (advisor)
This master thesis deals with stress-strain analysis of simplified model of the thin wall transformer case subjected to impact load of electrical blast. Electrical blast is replaced by chemical blast (detonation of high explosive). The problem is solved using computational modeling utilizing the Finite Element Method (FEM) and LS-DYNA solver. After the introduction where detonation and shock wave propagation is explained the analytical approach is presented. This approach serves to results verification. In the next chapter is conducted research of applicable methods from which ALE method is chosen. In preliminary study is performed the mesh size analysis that is focused on finding the size of element which is both computational effective and gives accurate results. Next the infulence of input conditions (shape, location and parametres of high explosive, location of detonation point, boundary conditions) on distribution and time progress of pressure is investigated. Then influence of the opening on upper side of the case on overall pressure redistribution and strain and stress of the case is analysed. The stress-strain analysis of the case´s door which are connected to case by various types of contact models is performed as well as stiffness analysis of these types of contact.
|
|
|
Launching and Operating Issues of Supersonic Business Jet
Kincová, Daniela ; Veselý, Petr (referee) ; Šošovička, Róbert (advisor)
Tato práce se zabývá problematikou zavedení a provozu nadzvukových business jetů. V dnešní době se v civilní letecké přepravě, po ukončení provozu Concordu, žádná nadzvuková letadla nevyskytují. V dnešní době existuje mnoho projektů a organizací, které se zabývají znovuzavedením nadzvukových letounů do civilního letectví a soustředí se převážně na business jety. Hlavní otázkou je, zda je vůbec vhodné, či rozumné se k tomu typu dopravy znovu vracet. Existuje hodně problémů, které toto komplikují. Tyto letouny způsobují příliš velký hluk, mají obrovskou spotřebu paliva a musí řešit nadměrné emise, létají ve vysokých výškách ve kterých může docházet k problémům s přetlakováním kabiny, navigací, radioaktivním zářením apod. Navíc zákaz supersonických letů nad pevninou letové cesty omezuje a prodlužuje. Současně vznikající projekty navíc nedosahují tak velkého doletu jako klasické moderní bussjety, což způsobuje, že se nadzvukové business jety se na delších tratích stávají neefektivní. I přes tyto problémy, je víceméně jisté, že k zavedení nadzvukových business jetů dojde během následujících 10 - 15 let, i kdyby to měla být jen otázka jisté prestiže velmi bohatých lidí.
|
|
|
Cable faults detection and layout
Marek, Tomáš ; Skalka, Miroslav (referee) ; Ondrůšek, Čestmír (advisor)
This bachelor´s thesis is focused on tracing cables stored in the ground. Determination of the depth, prelocation of cable defects, determination of exact point of the defect. This thesis gives review of different methods of tracing and prelocation of different types of defects and select the best method for their location. Bachelor´s thesis describes in detail different possibilities of tracing and prelocation of cable defects.
|
|
|
Analysis of the supersonic flow of gas in the differentially pumped chamber EREM
Matloch, Roman ; Vyroubal, Petr (referee) ; Maxa, Jiří (advisor)
This work describes briefly electron microscopy issue and physical model of fluid flow. Then presented diploma thesis will be describing analysis and evaluation of the impact of supersonic flow on the pressure and density in the path of the primary electron beam in the differential pumping chamber. For analysis, evaluation and examination of the issue will be used CAD and CAE (Computer Aided Engineering) programs. At the same time it will be developed a methodology of calculation applicable to supersonic flow in the low pressure system at ANSYS CFX.
|
|
|
Winding diagnostics using surge test
Vojtěch, Pavel ; Šlezingr, Jan (referee) ; Drápela, Jiří (advisor)
Master‘s Thesis deal with analysis given to diagnostic method plus her applicability to failure detection electrical machine plus apparatus in different phases their live. A further realization physical model with subtransient generátor PSG204A 4kV, for teach – in disorder on single – layer air coil plus stator winding induction motor inclusive evaluation results test.
|
|
|
Macroscopic traffic flow modelling
Pidrová, Kateřina ; Opluštil, Zdeněk (referee) ; Kisela, Tomáš (advisor)
This bachelor thesis is focused on macroscopic traffic flow modelling. First, we present a short introduction into the topic and basic model classification. Then we derive the continuity equation for macroscopic models and outline possible constitutive relations for a flux which determine the key features of the model. The main part of this work is focused on LWR model and its solution by the method of characteristic curves, with emphasize on shockwave creation. The thesis is concluded by an example and experiment comparing of the LWR model with real traffic on highway.
|
guest ::
