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Výživa cukrovky při nedostatku hořčíku v půdě
Dostal, Tadeáš
The goal of this project was to compare the different compounds of magnesium and its influence on yield and volume of sugar beet. This project was realized by small plot experiment in Pusté Jakartice u Opavy. Sugar beet was fertilizated using four different experiment setups: 1. not fertilized, 2. DUMAG (ammonium nitrate + magnesium nitra-te), 3. DASAMAG (ammonium nitrate + ammonium sulphate with magnesite), 4. MAGNISUL (ammonium nitrate + ammonium sulphate with kieserite). Variety with fertilizer DASAMAG has the highest yield of sugar beet. The highest digestion of sugar beet has non-fertilizated variety and variety with fertilizer DUMAG.
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Spatial interpolation and soil erosion modeling
Bek, Stanislav ; Ježek, Josef (advisor) ; Segeth, Karel (referee) ; Dostál, Tomáš (referee)
The doctoral thesis deals with selected methods of spatial interpolation and their applications to numerical modeling of the earth's surface, in particular soil erosion. The first part contains the description of the studied methods. Firstly and foremost, the method called regularized spline with tension (RST) is introduced. It has proven to be useful in interpolating elevation data. In the thesis, RST is presented in depth with the derivation of its radial basis function and its links to kriging. Further on the mathematics of digital terrain models and the tools for terrain geometric analysis are covered. The following chapter deals with the description of the soil erosion process and of the selected erosion models. The second part of the thesis summarizes five of the author's research articles which include applications of the described mathematical methods. The first two articles are devoted to the problem of elevation data interpolation and the building of digital elevation models. They deal with the optimization of the RST method for particular input data and target erosion models. The third article analysis the spatial structure of the soil data and the pedogenesis of the Žofínský prales natural forest. The last two articles deal with the spatial properties of heavy rainfalls and the mapping of...
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Fully-Differential Frequency Filters with Modern Active Elements
Langhammer, Lukáš ; Dostál, Tomáš (referee) ; Štork, Milan (referee) ; Jeřábek, Jan (advisor)
Tato disertační práce se zaměřuje na výzkum v oblasti frekvenčních filtrů. Hlavním cílem je navrhnout a analyzovat plně diferenční kmitočtové filtry pracující v proudovém módu a využívající moderní aktivní prvky. Prezentované filtry jsou navrženy za použití proudových sledovačů, operačních transkonduktančních zesilovačů, plně diferenčních proudových zesilovačů a transrezistančních zesilovačů. Návrh se zaměřuje na možnost řídit některý z typických parametrů filtru pomocí řiditelných aktivních prvků, které jsou vhodně umístněny do obvodové struktury. Jednotlivé prezentované filtry jsou navrženy v nediferenční a diferenční verzi. Velký důraz je věnován srovnání plně diferenčních struktur s jejich odpovídajícími nediferenčními formami. Funkčnost jednotlivých návrhů je ověřena simulacemi a v některých případech i experimentálním měřením.
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Filtering structures for fotovoltaic power stations
Hruška, Petr ; Dostál, Tomáš (referee) ; Petržela, Jiří (advisor)
This thesis is dedicated to an issue of vibration of photovoltaic panels, which manifests itself primarily in the acoustic field. From the photoelectric effect is gradually getting through photovoltaic cell, panel, string, power plant to define the causes of the vibration. The aim of the work is to design electrical low pass filter that suppress disruptive elements, which prevents audible vibrations of panels and the whole system of photovoltaic power plants.
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Class D stereo audio power amplifier
Kazelle, Kamil ; Dostál, Tomáš (referee) ; Brančík, Lubomír (advisor)
The content of this project is design of stereo audio amlifier working in class D with output power 2x20W. Project includes also a design of preamplifier and power supply. This project is divided into the four parts. In first part the theory and problems of amplifiers working in class D is resumed, in the second the designed circuits are dicussed, in the third the results of simulations in the program PSpice are presented and the last part of project describes the realization and presents the results of measurements.
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Application of the syntetic blocks in the electronic circuit synthesis
Labudík, Marek ; Dostál, Tomáš (referee) ; Petržela, Jiří (advisor)
n project is investigated synthetic coils and FDNR, circuits are first simulated in a snap, which I obtained the graph of the input impedance at the frequency and formula to calculate the impedance. The results of this simulation were used for the simulation program PSPICE, the districts where I was compared with the equivalent circuit, which I design on the formula of the snap. Some of the investigated synthetic and FNDR coils were then used for simulation of the oscillators.
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Active Frequency Filters for Higher Frequencies
Fröhlich, Lubomír ; Dostál, Tomáš (referee) ; Biolek, Dalibor (referee) ; Sedláček, Jiří (advisor)
This thesis deals with the synthesis and optimization of frequency analogue filters with modern active elements usable for higher frequencies. The thesis is divided into three parts, the first part deals with the problematic concerning Leap-Frog combined ARC structure. Due to a difficult design, this method is not described in a detail and used in practice, although it shows e.g. low sensitivity. Firstly, a complete analysis of individual filters was made (for and T endings) and consequently these findings were used during implementation of this method to NAF program. Finally, samples of real filters were realized (for verification of functioning and correct design). Another very interesting topic concerning filters is usage of coupled band-pass for small bandwidth, where it is necessary to solve the problems concerning ratio of building elements values, but also price, quality, size of coils, sensitivity, Q factors, coefficients etc. That is why in practice a coil is very often substituted with other equivalent lossy and lossless blocks which create ARC filters structure. The design and the possibility of usage of lossy grounded elements were described here (such as synthetic inductors, frequency dependent negative resistor). Some parts of the design are individual computer sensitivity analysis, setting of usage and quality comparison of individual lossy grounded blocks. Besides, a program for these elements was created, it is useful for a quick design and depiction of transfer characteristics. The third part deals with the usage of tuning universal filters consisting three or more operational amplifiers, which secures its universality and possibility to create different kinds of transfer characteristic. In practice, Akerberg - Mossberg and Kerwin - Huelsman - Newcomb are the most used types of filters. These were also compared with less common universal filters. In the end, the possibility of digital tuning of universal filter with the help of digital potentiometers for filters of 10th order and frequency around 1 MHz was shown.
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