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Seasonal dynamics of physiological parameters of Norway spruce needles in mountain forest in relation to water balance of the forest site
Bednář, Pavel ; Albrechtová, Jana (advisor) ; Gebauer, Roman (referee)
Norway spruce (Picea abies (L.) Karst.) is an important economic tree species in the Czech Republic, which is currently significantly weakened and dying under the impacts of climate change. In young spruce forest stand in mountain region that was artificially established after the large-scale disturbance of forests in the mid-1990s, on the "U Dvou louček" research plot represented by a small forest catchment of an area of 32.6 ha, located in the upper part of the Orlické Mountains at an altitude of 880 - 920 m a.s.l., and in site conditions of predominantly Abieti-fageta piceae - water balance measurements were carried out during the 2019 and 2020 growing seasons. At the same time, during the mentioned two years, in total 6 samplings of biological material were carried out according to a standardized sampling methodology, and laboratory analyzes were carried out on this material. Laboratory analyzes were focused on three established age categories of needles, namely 1, 2, and 4 or more years old. The biophysical parameters of needles were determined based on the measurement of structural parameters and concentrations of photosynthetic pigments - chlorophyll a, chlorophyll b and total carotenoids from samples extracted in DMF using a laboratory spectrophotometer. Optical properties of the needles...
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Physiological status of young silver fir on stands with different microclimate using biochemical, and optical needle traits.
Kabilková, Eva ; Lhotáková, Zuzana (advisor) ; Pokorný, Radek (referee)
Silver fir (Abies alba Mill.) is a candidate tree species in the process of forest transformation especially of spruce monoculture stands (Picea Abies (L.) H. Karst.), thanks to its better growth characteristics in conditions of mild drought. However, fir, as a very shade tolerant tree, may be more susceptible to various abiotic stressors in more open forest canopies, and therefore it is necessary to study its ecological requirements in connection with the most effective possible application in forestry. In this thesis, the physiological state of young fir stands affected by different light microclimatic conditions, which were represented by different types of forest regeneration, was studied. Specifically, it is shelter-wood cut, which represents the likely highest degree of shading by mature trees, then natural regeneration under sparse canopy, gap cut and small clear cut, which represent a moderate degree of shading by mature trees, and last but not least, clear cut, which represents the lowest degree of shading. Physiological status was evaluated using biochemical and optical properties of the needles, and additional microclimatic conditions of the habitats, namely temperature and soil moisture, were also evaluated. Our results showed that the used biochemical and optical properties of the...
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Design of measurement unit for analysis of surface materials properties
Kratochvíl, Robert ; Rozsívalová, Zdenka (referee) ; Frk, Martin (advisor)
The thesis deals with the application of laser beams for examination of material properties. The properties being examined are quality of surface finish and transmissivity of materials in the optical portion of the electromagnetic spectrum. A measuring device containing laser diodes as a source of laser beam and photodiodes for evaluation of examined phenomena serves for examination of both properties. Conversion of the signal to digital quantity and its further processing take place in a microcontroller. The data is then sent via a serial bus and a converter to a computer, where it may be saved in a user program and where the user can work with them later. The thesis contains results of reflectivity measurement of a set of metal samples with different surface finish. Transmissivity measurement was applied on a set of optical filters.
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Testing of room acoustics
Toufarová, Tereza ; Špalek, Karel (referee) ; Sigmund, Milan (advisor)
This paper presents parameters of evaluation of acoustic quality of the space. It is divided into parts presenting physical principle of the origin and movement of the acoustic signal, principles of its processing with current technology and properties of the acoustic field. This is followed by an analysis of the musical part and notes on psychoacoustics. The document contains a description of relevant parameters of acoustic spaces and way in which we can reach desired results, including material analysis. The paper mainly focuses on description of relevant parameters of three acoustic spaces which were measured. The last part of the work is a program for elementary acoustical measurement, which can be provided by means of commonly accessible equipment such as a notebook or a personal computer.
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Imaging Reflectometry Measuring Thin Films Optical Properties
Běhounek, Tomáš ; Spousta, Jiří (referee) ; Zicha,, Josef (referee) ; Kotačka, Libor (referee) ; Druckmüller, Miloslav (advisor)
V této práci je prezentována inovativní metoda zvaná \textit{Zobrazovací Reflektometrie}, která je založena na principu spektroskopické reflektometrie a je určena pro vyhodnocování optických vlastností tenkých vrstev .\ Spektrum odrazivosti je získáno z map intenzit zaznamenaných CCD kamerou. Každý záznam odpovídá předem nastavené vlnové délce a spektrum odrazivosti může být určeno ve zvoleném bodu nebo ve vybrané oblasti.\ Teoretický model odrazivosti se fituje na naměřená data pomocí Levenberg~-~Marquardtova algoritmu, jehož výsledky jsou optické vlastnosti vrstvy, jejich přesnost, a určení spolehlivosti dosažených výsledků pomocí analýzy citlivosti změn počátečních nastavení optimalizačního algoritmu.
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Physical-chemical property characterisation of thin reflective layers on silicon substrates
Rozsívalová, Zdeňka ; Studýnka, Jan (referee) ; Krčma, František (advisor)
This thesis deals with surface analysis and characterization of optical features of thin films created by hexamethyldisiloxane (HMDSO) plasma polymerization on silicon wafers. The RF plasma industrial deposition equipment was used for the thin layers formation. These thin films serve as protective coatings on the reflective layer in the car light or solar panels. Theoretic part gives basic information about plasma, its occurrence, features, diagnostics and applications. Thin layers, their production and characterization are discussed here, too. Theoretic description of monomer material (including the group of other organosilicones) is also presented here. The FTIR spectroscopy and elipsometry are mentioned as the main methods for thin films characterisation. Because material during its practical use degrades due to external conditions, the influence of them on the thin layer properties is studied using the accelerated aging of created films. Industrial deposition chamber AluMet 1800V made by Leybold Optics, Ltd. installed in Zlin Precision company was used for the thin films production. Thin films were created under different conditions that were selelected near to the real conditions used in technology. Various applied powers (2-5 kW) were used for the deposition under different monomer flows. Further, the influence of oxygen addition on the created film properties was investigated. The deposition process was monitored by optical emission spectroscopy. The spectrometer Jobin Yvon Triax 320 with CCD detector was used. The selected part from every samples set was exposed by UV radiation (48 hours at radiation density of 0.68 W/m2 at 340 nm) to simulate the probable conditions during the layers real use. The surface properties were investigated by measurement of reflected light spectral intensity in the visible range at different angles. The angle between incident and reflected beam was varied in the interval of 40 - 150° with 10° step. The influence of sample preparation conditions as well as their aging effect was studied at the selected angles. Spectral reflectance doesn´t depend significantly on applied discharge power and oxygen addition. The significant shift of reflectance into the red part of spectrum was observed at UV exposed samples more or less independently on the applied discharge power of monomer flow rate. Addition of oxygen during the deposition suppresses this effec significantly. Characterization of thin layer structure was done by FTIR spectroscopy. No significant changes were observed in the structure at different discharge powers of monomer flow rates except total absorption intensities that are proportional to the layr thickness. The oxygen addition, of course, changes the structure significantly. These results are only preliminary because the layers were very thin (deposition conditions were near to the common process standard) and thus the signal/noise ratio was relatively low.
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Local characterization of electronic devices
Müller, Pavel ; Škarvada, Pavel (referee) ; Tománek, Pavel (advisor)
The development of micro and nanoelectronics and nanophotonics needs novel characterization techniques to ensure higher quality of designed devices. The thesis describes a use of Scanning Near-field Optical Microscopy (SNOM) in dimensional control and in local investigation of diverse physical parameters. As example of its potential, the correlation between object topography and reflection measurement of capacitors is shown.
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IR thermometer with automatic emissivity correction
Dobesch, Aleš ; Tannenberg, Milan (referee) ; Poliak, Juraj (advisor)
Diploma thesis deals with basic physical quantities and laws relating to non-contact temperature measurement and emissivity determination of solids. It describes the design and implementation of the IR (Infra-Red) thermometer often missed with automatic emissivity correction. The first chapter explains the concept of temperature and basic principles of temperature measuring . The second chapter focuses on the history and theory of non-contact temperature measurement. Gradually are explained the concepts related to non-contact temperature measurement and the problem of determining the emissivity of the body. Next third chapter describes the proposed hardware solution of IR thermometer. The fourth chapter describes a software written for the IR thermometer. The fifth and last chapter summarizes the findings and knowledge from the implementation of non-contact thermometer and measuring emissivity.
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Evaluation of the physiological status of European beech in its plantings on localities following the gradient of its ecological valence
Palouš, Daniel ; Albrechtová, Jana (advisor) ; Tomášková, Ivana (referee)
European beech (Fagus sylvatica L.) is one of the dominant tree species in Europe, presenting a keystone species for forest ecosystem functioning. The ongoing climate change alters the environmental conditions in the areas of the current distribution of European beech, leading to stress. Concerning the critical health status of forests in the Czech Republic and other European countries, it's even more urgent to monitor the health status of forests. For this, tools for early detection of a stand's physiological status decline are needed. The aforementioned tools can consist of indicators of the physiological status suggested by this thesis. This thesis aims to evaluate the applicability and sensitivity of the preselected set of indicators of the physiological status of European beech to the gradient of environmental conditions (temperature, precipitation) within its ecological valence. Four stands of European beech presenting the gradient of beech's ecological valence were observed over the peak of one vegetation season. Stand Kocanda presented the microclimatic and ecological optimum; stand Hradecko was on the lower margin of the altitudinal gradient of European beech distribution and presented the limit of low water availability; stand Deštné was on the upper margin of the altitudinal gradient of...
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Laboratory/Field Spectroscopy and Remote Sensing Image Data for Vegetation Studies
Červená, Lucie ; Kupková, Lucie (advisor) ; Pavelka, Karel (referee) ; Müllerová, Jana (referee)
Dominant vegetation species of two structurally and functionally different montane ecosystems were studied by means of laboratory and field spectroscopy and remote sensing image data: (1) a homogeneous human-influenced evergreen coniferous forest represented by a Norway spruce forest in the Krušné hory Mountains and (2) a heterogeneous natural ecosystem of a relict arctic-alpine tundra in the Krkonoše Mountains with predominance of grasses. The first part dealing with the Norway spruce forest is especially focused on the methods of laboratory spectroscopy. The assessment of Norway spruce stands on a regional and a global scales requires detailed knowledge of their spectral properties at the level of needles and shoots in the beginning, but ground research is very time-demanding. Open spectral libraries could help to get more ground-truth data for subsequent analysis of tree species in forests ecosystems. However, the problem may arise with the comparability of spectra taken by different devices. The present thesis focuses on a comparability of spectra measured by a field spectroradiometer coupled with plant contact probe and/or two integrating spheres (Paper 3) and proves the significant differences in spruce needle spectra measured by the contact probe and integrating sphere, spectra of...
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