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Study utility properties of heat-reflective insulation for the buildings
Rauchfussová, Karolína ; TROJAN,, Karel (referee) ; Šťastník, Stanislav (advisor)
Presented work deals with the study progressive heat-reflecting foil thermal insulating materials and defines their thermal insulation properties. The work describes a transport mechanism of thermal energy in the structure of heat-reflecting materials, their physical properties, especially heat resistance, compared to the conventional thermal insulating materials available on Czech market. The main applications ways and installation methods of these materials (especially in low-energy and passive buildings) are also shown. The practical part is focused on asembling the measuring device HOT BOX in accordance with the valid standards, to determine the heat resistance of heat-reflecting materials. In next step the measurement of reflection of aluminum foils (an integral part of the structural arrangement heat-reflecting foil insulations) was performed.
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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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Light propagation in magnetic materials
Wagenknecht, David ; Ostatnický, Tomáš (advisor) ; Veis, Martin (referee)
Transparent magnetic materials, among the others semiconductors, have recently come to the focus of interest in both basic and applied research because they have great potential in optical applications and they can be used in optical spectroscopy to investigate fundamental physical phenomena. The theoretical calculations introduce that these materials have some extraordinary properties like asymmetric reflectance when light impact the sample from the opposite angles. In this bachelor thesis, transfer matrix formalism is derived based on Maxwell equations, taking into account special form of effective permittivity. The reflection coefficient for one layer demonstrates, that the asymmetric reflectance appears for transversal- magnetic polarization of light and transversal magnetization in the studied material. The derived formulae are used to calculate the difference in reflectivities for the waves impacting the structure from opposite angles. Ga1−xMnxAs with different concentrations of manganese is assumed to be the essential transparent magnetic layer in the sample. 1
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Laboratory spectroscopy for selected Krkonoše Mts. tundra vegetation species
Tomcová, Jana ; Červená, Lucie (advisor) ; Lhotáková, Zuzana (referee)
Laboratory spectroscopy for selected Krkonoše Mts. tundra vegetation species The diploma thesis is focused on testing the methodologies of measuring the reflectance of grasses from the tundra of Krkonoše Mountains (Nardus stricta, Molinia caerulea, Calamagrostis villosa). The spectoradiometer ASD FieldSpec 4 Wide-Res with added contact probe ASD Plant Probe is used for measurements. Since it is not common to measure such narrow leaves that do not cover the whole FOV, the thesis is looking for methodologies that are the most repeatable and influenced by a minimum of errors. Factors influencing the measurement results are also monitored. Furthermore, the differentiation of the studied species is observed based on their spectral properties. Based on the measured data the medians and standard deviations are calculated and compared among each other. An analysis of variance (ANOVA) is used to determine the bands where the influence of individual factors is more apparent and where the individual grasses are distinguishable. As the most suitable methodologies for measuring grasses depend on the grasses structures and properties, the best methodology is different for each of selected species. The two layer leaf measurement is most suitable for the Nardus stricta, the measurement of the abaxial sides of leaves fits...
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Laboratory spectroscopy for selected Krkonoše Mts. tundra vegetation species
Tomcová, Jana ; Červená, Lucie (advisor) ; Lhotáková, Zuzana (referee)
Laboratory spectroscopy for selected Krkonoše Mts. tundra vegetation species The diploma thesis is focused on testing the methodologies of measuring the reflectance of grasses from the tundra of Krkonoše Mountains (Nardus stricta, Molinia caerulea, Calamagrostis villosa). The spectoradiometer ASD FieldSpec 4 Wide-Res with added contact probe ASD Plant Probe is used for measurements. Since it is not common to measure such narrow leaves that do not cover the whole FOV, the thesis is looking for methodologies that are the most repeatable and influenced by a minimum of errors. Factors influencing the measurement results are also monitored. Furthermore, the differentiation of the studied species is observed based on their spectral properties. Based on the measured data the medians and standard deviations are calculated and compared among each other. An analysis of variance (ANOVA) is used to determine the bands where the influence of individual factors is more apparent and where the individual grasses are distinguishable. As the most suitable methodologies for measuring grasses depend on the grasses structures and properties, the best methodology is different for each of selected species. The two layer leaf measurement is most suitable for the Nardus stricta, the measurement of the abaxial sides of leaves fits...
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How does the leaf structure determine the leaf optical properties.
Peychlová, Anna ; Lhotáková, Zuzana (advisor) ; Tylová, Edita (referee)
An internal leaf structure determines the way the light passes through the leaf and, thus, in this way it affects the use of the light in photosynthesis. The light reaching the leaf can be reflected, absorbed or transmitted. Leaf reflectance properties depend on the wavelength of irradiation and on the physical, structural and chemical properties of a leaf. Thereinafter, this Bachelor thesis briefly describes spectral methods used to study leaf optical properties. Furthermore, the thesis focuses on leaf anatomical structures and their effect on leaf optical properties, mainly in visible region of electromagnetic radiation (400-700 nm) and in near- infra-red region (700-2300 nm). The emphasis is given to the following anatomical properties and structures: epidermis, cuticle, trichomes, mesophyll structure, leaf thickness, chloroplast movement, chlorophyll content and distribution. The aim of the thesis is to summarize current knowledgeon this topic. Key words: leaf anatomy, leaf optical properties, reflectance, intercellular spaces, radiative transfer
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Study of utility properties thermal-reflective insulations in the buildings
Holeček, Dominik ; Skříček, Darek (referee) ; Šťastník, Stanislav (advisor)
The diploma thesis is partly dedicated to energetic efficiency of buildings and describes possibilities how to evaluate energetic efficiency of buildings in the Czech Republic. We also get to know with distribution of thermal insulators by material base and use in construction. There are also mentioned methods how to determine thermal insulations characteristics of heat insulations, so called heat conductivity coefficient. The last and the crucial chapter of theoretic part is dedicated to thermal-reflective insulations. There are mentioned some of the basic characteristics of insulations, material composition and heat transfer mechanism in their structure as well. Practical part describes measurement of thermal resistance of chosen samples of thermal-reflective insulations per measuring device on the principal of Hot Box method. In the next step was determined emissivity of aluminium foils which forms the surface of chosen samples of thermal-reflective insulations. In the end of thesis are defined possibilities of use thermal-reflective insulations in building structures especially in passive and low-energy buildings in climatic conditions of the Czech Republic.
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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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