National Repository of Grey Literature 8 records found  Search took 0.02 seconds. 


Formation of organics molecules initiated by high-power density energy events in planetary atmospheres
Kamas, Michal ; Civiš, Svatopluk (advisor) ; Zelinger, Zdeněk (referee)
The focused laser beam delivered by the high-power laser system PALS was used for laboratory simulation of high-energy-density events in a planetary atmosphere. Several model gas mixtures were prepared to mimic the mildly reducing early Earth's atmosphere (CO-N2-H2O) as well as the atmosphere of Saturn's moon Titan and the strongly reducing early Earth's atmosphere (CH4-N2-H2O). In situ investigation of transient species generated by the laser-induced dielectric breakdown in the gaseous mixtures was performed by optical emission spectroscopy (OES). Final products of laser-plasma initiated chemical reactions were identified and determined by advanced mass-spectrometry (SIFT-MS) and absorption FT-IR spectroscopy. High-power laser system SOFIA was utilized to simulate in our laboratory a high-velocity impact into the icy satellites of the outer planets of the Solar system. OES was engaged in probing the plasmas produced by the SOFIA beam focused on ice surfaces (water, methanol, formamide), while final products were analyzed by means of gas chromatography (GC/MS) and mass-spectrometry (SIFT-MS).

Remote sensing for evalution of state and development of Spruce stands condition in the Giant Mountains
Musilová, Romana ; Kupková, Lucie (advisor) ; Štych, Přemysl (referee)
Bc. Romana Musilová: Využití dat DPZ pro hodnocení aktuálního stavu a vývoje smrkových porostů v Krkonoších Remote sensing for evaluation of state and development of Spruce stands condition in the Giant Mountains Abstract Monitoring the health status of forest areas using remote sensing methods are still under development. This master thesis focuses on the use of SPOT, Landsat, QuickBird and WorldView-2 images to evaluate condition of spruce stands in Giant Mountains National Park. For these purposes were selected vegetation indices available in the lite- rature. First satellite images were preprocessed and subsequently calculated vegetation indices. From the generally known were used Normalized Difference Vegetation Index, leaf area index and Simple Ratio. Than were calculated Green Vegetation Index and Red Green Index based on the monitoring of needles color changes. To evaluate moistu- re conditions were used indices Foliar Moisture Index and wide-band Normalized Diffe- rential Infrared Index. The goal was a comparison of the results of these indices and assessment of their applicability. Map outputs indices were compared with maps of de- foliation and mortality of coniferous stands by Ing. Milan Stoklasa. Keywords: remote sensing, Norway Spruce stands, Giant Mountains, vegetation indi- ces, SPOT,...


Samples of the influence of the parameters of the simulation model of the planetary gear system with four single satellites and with stopped planet carrier to its dynamic properties
Hortel, Milan ; Škuderová, Alena
The report deals with examples of numerical solutions of the influence of parameters on the internal dynamics pseudoplanetary transmission system with four single satellites with the front straight teeth and the stopped carrier of satellites type Wikov PP. The analysis of the internal dynamics of the pseudoplanetary system with front straight teeth was carried out by analyzing of amplitude-frequency characteristics of relative motions in gear mesh of wheels at a maximum speed range of the central wheel 0 up to 22500 rpm for total of 12 variations differing in combinations of parameters, ie. the moments of inertia of cogwheels, the friction and the damping in gear mesh and the resulting error function of meshing involute tooth profiles.\n

Dynamic model of planetary gearbox with four satellites and standing planet carrier
Hortel, Milan ; Škuderová, Alena
The precised mathematical and physical weakly and strongly nonlinear parametric dynamic model pseudoplanetary transmission system with kinematic couplings, ie. four satellites with front straight toothing and standing planet carrier (model Wikov type PP) with 28 degrees of freedom was compiled within the project TAČR TA04011656 follow-up to previous research reports Z-1512/14, Z-1521/14, Z-1537/15. Model respects both elastic supports of all gears and by means Heaviside functions possible contact bounces of meshing gear profiles in the area of the lateral tooth clearances. There are a impact effects upon re-contact of tooth flanks both in normal and during the eventual inverse gear meshes, depending on the size of dynamic forces in gearing. Based on the explicit expression of Lagrange equations of this model, the simulation model of transmission system is prepared in MATLAB / Simulink.

To the analytical dynamic analysis of non-linear parametric systems with gears
Hortel, Milan ; Škuderová, Alena
In contrast to the mathematical methods of solution of the linear dynamic problems are the analytical solution methods and the analysis of non-linear at that the analysis of the time heteronymous, i.e. parametrical, problems more complicated and difficult. In these systems can occur the various dynamic behaviour, where appear, in the certain sensible areas of the tuning, the new often unexpected phenomena, such as the patterns of the solution ambiguity, the bifurcation and the splitting of the resonance characteristics, the change over the regular motions into the irregular, up to the motions with deterministic chaotic character etc. The above mentioned and the another phenomena can occur at the more precise physical modelling in the category of the high-parametrical, i.e. in the light high-speed structures, for example in the aeronautical propjets, where today the revolutions of the driving turbines are reaching the 80000 rpm. For the analysis of the mentioned phenomena of the relativ

Past dynamic of alpine treeline ecotone in the eastern part of the Krkonoše Mts.
Jungrová, Alena ; Treml, Václav (advisor) ; Chuman, Tomáš (referee)
4 Abstract The purpose of the diploma thesis is the analysis of changes in the alpine treeline ecotone with focus on the age structure and cover of the Norway spruce (Picea Abies) in the Giant Mountains in the 20th century. The altitudinal position and the tree density of the alpine treeline ecotone is a sensitive indicator which reflects the human impact as well as the climatic and air pollution changes. Methodical approach included the measuring of the age structure of the Norway spruce by using dendrochronology. In addition the changes of the spruce cover were evaluated from a series of aerial photographs dated 1936, (1953) 1964, 1985 and 2002. Those photographs were orthorectified and classified. The age distribution in the majority of the sample locations is irregular with some prominent peaks that are corresponding to the periods of good conditions and dips pointing out to the periods of disturbances. There is an evident peak during the 30s and 40s which is the same period of the increase of average temperatures of the growing season. On the contrary, depression during the 70s and 80s is detected only in the case of closed-canopy forest. The increasing number of trees during the 90s is related to the decreasing air pollution and to the higher average temperature. Relatively young age structure of the...