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Theremin
Musil, Petr ; Olejár, Adam (referee) ; Vlček, Lukáš (advisor)
This bachelor thesis focuses on the construction of the musical instrument theremin. Theoretical section of this thesis describes various types of oscillator and its potential use in construction of the musical instrument. Practical section of this thesis deals with specific circuit design, its simulation and construction of pitch control circuit, volume control circuit, mixer, preamplifier and supply voltage regulator. Principle of operation is based on mixing two high frequency signals produced by Colpitts oscillators.
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Multimedia Transmission in MPLS Network
Vlček, Lukáš ; Novotný, Vít (referee) ; Polívka, Michal (advisor)
Thesis introduces positive traits of MPLS technology comparing to other transportation mechanisms in WAN environment, refers to its cons. The next section of thesis describes fundamentals of routing and switching in MPLS trying to make accent of different methods between routing in IP network and MPLS network. Following part focuses on topic about Traffic Engineering, its methods and practices. Another part of thesis is about Traffic Engineering in MPLS and its posibilities of controling data flow. Last section describes planning, implementation and operation of experimental MPLS network. Conclusion summarizes achieved results and sets further goals to complete whole fulfillment of thesis assignment.
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Dynamics of surface water quality changes in model headwater areas of the Czech Republic
Fraindová, K. ; Matoušková, M. ; Kliment, Z. ; Vlček, Lukáš ; Vlach, V. ; Šajnarová, L.
River headwaters have a high environmental value. Unfortunately, the biogeochemical processes in headwaters in context of different rainfall-runoff conditions and specific land cover have not been fully examined. This study focuses on changes in correlations of 16 biogeochemical parameters related to different types of rainfall-runoff events and land cover condition for eight headwater catchments in Central Europe. Multiple methods as linear regression, Spearman rank correlation, Principal Components Analysis and C/Q hysteresis loops revealed main relationships. Presence of peatlands and waterlogged spruce forests had decisive influence on the biogeochemistry (mainly for CODMn, humins, Fe, P-PO43− TP, and N-NO3−). The strongest positive correlation of organic matter (CODMn) and Fe is represented in a catchment with the largest area of damaged forest (70%), but with a smaller proportion of wetlands (8%). High flow rates influence the release of greater amounts of organic matter and N-NO3−.
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Dynamics of dissolved organic carbon in surface water during extreme rainfall-runoff events
Matoušková, M. ; Fraindová, K. ; Bejčková, M. ; Kliment, Z. ; Vlach, V. ; Vlček, Lukáš
The release of a greater amount of natural organic matter (NOM) within climate change is registered in many catchments with peatbog areas. The aim of our research is to study the dynamics of releasing dissolved organic carbon (DOC) into surface water in headwater areas with peatbogs. DOC concentrations are analysed in relation to extreme rainfall-runoff (R-R) events and according to the hydrological preconditions of the basin. These preconditions are described using selected hydroclimatic variables (14 days before the R-R event). The source data comes from stations of the Faculty of Science, Charles University, and the Czech Hydrometeorological Institute. For the evaluation of relations and processes, the Principal component analysis (PCA), hysteresis loops or Pearson correlation coefficient was used. The lag time of DOCmax for Qmax, the dependence of DOCmax and groundwater levels were studied. The influence of flow rate on the decline and ascent phases of DOC\nconcentrations by hysteresis loops and the influence of the number of partial flow maximums on the amount of transported DOC during the R-R event was analysed. Our first results show that great influence on the dynamic of DOC concentration in surface water has the change in groundwater-levels in the peatbog and the outflow amount during the R-R event. The hydroclimatic preconditions of the basin have also a significant influence on the DOC release. Changes in concentrations during R-R events also occurred for other compounds that were studied additionally. Particularly significant was the increase in metals (mainly Fe, Al, Mn) and base cation (K) and decrease in nitrate nitrogen.
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Soil and hydrological degradation of wetlands
Panocha, Tomáš ; Vlček, Lukáš (advisor) ; Šefrna, Luděk (referee)
The thesis researches the knowledge about soil degradation and the most important soil degradation processes, including desertification, erosion, the impact of agriculture on soils and soil sealing. It also deals with wetlands as ecosystems at the transition between aquatic and terrestrial systems, their definition and delineation, as well as their decline and recovery, which is very important in climate change projections. The chapter on wetlands also includes a section on international conventions and organisations. The work then focuses on wetland types in the Czech Republic and the soil types most commonly found on them, together with their soil-forming processes and water regimes. Last but not least, the thesis tries to find a link between the degradation of wetland ecosystems in relation to changes in the hydrological regime of the surrounding area and the surrounding soils. Keywords: soil degradation, wetland, wetland definition, wetland restoration, wetlands of the Czech Republic
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Time variabilty of soil hydraulic properties and their impact on soil moisture estimation
Šípek, Václav ; Vlček, Lukáš ; Tesař, Miroslav ; Zelíková, Nikol ; Hnilica, Jan
The study was focused on the temporal variability of saturated hydraulic conductivity in an experimental plot covered by spruce forest and investigated benefits of its incorporation into soil water balance model. The results showed that the higher saturated hydraulic conductivity (33.6-44.8 cm hr-1) was observed in summer period compared to lower values (13.2-22.3 cm hr-1) in the winter period. The use of seasonally variabile saturated hydraulic conductivity improved the efficiency of soil water balance model in terms of lower root mean square error between observed and simulated volumetric soil water content by 33.2 %. The Nash-Sutcliffe coefficient rose from 0.34 to 0.68.
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Runoff from a mainly peat bog basin
Vlček, Lukáš ; Falátková, Kristýna
This research focuses on the basin's hydrological regime, where peatlands make up approximately half of the area. Hydrological processes in the peat bog and the surrounding forest were evaluated using the HBV model. The results show that the peatlands significantly increase the water regime fluctuation of local streams. Moreover, water balance shows a lower cooling effect of tree-less peat bogs than forests on organo-mineral soils. Except for a positive ecological aspect, peatland restoration can have a negative hydrological impact on the surrounding landscape and local streams.
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Report on the hydroledological survey in the Černý Důl, Krkonoše Mts.
Šípek, Václav ; Vlček, Lukáš ; Zelíková, Nikol
The report documents results of hydropedological survey in the Černý Důl, Krkonoše Mts. Two experimental sites were selected based on the requirements of National Park Krkonoše with the aim to determine the effect of bark beetle outbreak on the soil water regime. The report contains description of soil hydraulic properties at two plots (healthy and impacted forest) for several soil horizons which will serve as a basis for hydropedological model.\n
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Modelling the impact of potential restoration of small reservoirs on the hydrological regime at the upper Vydra River basin.
Purm, Marek ; Vlček, Lukáš (advisor) ; Jeníček, Michal (referee)
The presented diploma thesis deals with the implementation of the SWAT eco- hydrological model at the upper Vydra basin in Šumava. In the first simulation, the model was built without inserted extinced small water reservoirs. In the second simulation, the effect of the possible inclusion of the small water reservoirs on the transformation of peak flows and the mitigation of low flows during dry periods is studied. To achieve the desired results, the SWAT model was used. This model is still not widely used in our territory. Model calibration was performed using the SWAT-CUP semi-automatic calibration software. Through the conducted research, it was found that in the case of the inclusion of some reservoirs, there is a slight reduction in peak flows and an improvement in low flows during dry periods. The influence of the inclusion of the reservoirs in the final profile of the basin of interest in Modrava is less apparent. The results also include a option with the five times greater volume of the reservoirs. The presented results and their discussion could provide more detailed information about the inclusion of today's defunct reservoirs in the runoff regime in the upper Vydra basin. Key words: SWAT, SWAT-CUP, horni Vydra basin, small water reservoir, hydrological modelling
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Changes of natural organic substances within hydrological extremes in headwater areas
Bejčková, Marie ; Matoušková, Milada (advisor) ; Vlček, Lukáš (referee)
Diploma thesis is focused on changes of natural organic matter within hydrological extremes in headwater areas of the upper Vydra. The increace in these concentrations and increased transport to surface waters negatively affect the environmental and social environment. The main aim of this work is to analyse the amount and variability of organic metter in relation to selected runoff events with clarification of these relationship. The change in the amount of concentrations and variability of Dissolved Organic Carbon (DOC) was evaluated with respect to the preconditioning of the catchment (over a period of 14 days) and the influence of hydroclimatic conditions during the episodes. The dependence of each variable on DOC concentrations was also examined. The dependence of parameters (water temperature, conductivity, flow rate, pH, Dissolved Oxygen, Dissolved Organic Carbon concentration) within the campaigns and the subsequent similarity of the profiles were also investigated. The data for this work were provided by the Department of Physical Geography and Geoecology, Faculty of Science, Charles University. The evaluating of relationship and processes was determined, for example, using Principal Component Analysis (PCA Analysis), hysteresis loop or Pearson's correlation coefficient. The greatest...
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