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Dissolved and gaseous nitrogen losses in forests controlled by soil nutrient stoichiometry
Oulehle, Filip ; Chuman, T. ; Hruška, Jakub ; Krám, Pavel ; Navrátil, Tomáš ; Tesař, Miroslav ; Ač, Alexander ; Urban, Otmar
This study investigates the consequences of chronic nitrogen deposition in forests, including its effects on soil and surface water quality, and greenhouse gas emissions. To predict these effects, the authors explore the controls over dissolved and gaseous nitrogen fluxes in temperate forests. Their findings indicate that stream leaching losses of dissolved nitrogen correspond with the nutrient stoichiometry\nof the forest floor, with stream N losses increasing as ecosystems progress towards phosphorus limitation. Soil nitrogen storage increases with oxalate extractable iron and aluminium content. The authors estimate soil gaseous losses based on 15 N stocks, which averaged 2.5±2.2 kg N ha-1 year-1 , comprising 20±14% of total nitrogen deposition. They also extrapolate the current gaseous nitrogen loss flux from forests globally to be 8.9 Tg N year-1 , which represents 39% of current nitrogen deposition to forests worldwide.
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A study of the behavior of selected metals in affected environments using an isotopic approach
Santos Baieta, Rafael ; Mihaljevič, Martin (advisor) ; Navrátil, Tomáš (referee) ; Tejnecký, Václav (referee)
Metals of anthropogenic origin have consistently polluted the environment. This thesis focuses mainly on highly contaminated soils or tree rings near mines and smelters in Sub-Saharan Africa. However, Portuguese soils were also assessed to study Pb isotopes in post-fire soils. The tracing capabilities of Pb isotopic ratios were employed to determine contamination sources and to evaluate the potential of pine trees as an environmental archive. Several analytical methods were applied, such as catalytic oxidation, Q-ICP-MS, ICP-OES, FEG-SEM/EDS, EPMA, XRD, etc. Soils near smelters located in three different cities [Kabwe (Pb-Zn), Luanshya (Cu, Co), and Selebi Phikwe (Ni, Pb)] exhibited concentrations of metals greatly exceeding those deemed acceptable by the competent authorities. In Kabwe, for example, concentrations of Pb exceeded 16 000 mg kg-1 . In all sites, contamination was shown to be significant only in the upper ±15 cm of soil. Samples of soils taken in remote locations were always clear of contamination. In Luanshya, metal(oid) bearing particles found in the soils were typically spherical and composed of rapidly cooled sulfides and oxides in the flue gas chambers of the local smelter. These were present only in the topsoil. The tree ring record of pine trees in Kabwe was shown to mimic the...
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Variation of Pb-isotopic composition in coal basins
Čurda, Michal ; Strnad, Ladislav (advisor) ; Mihaljevič, Martin (referee)
This Bachelor Thesis is devided into three main parts. The first part has a character of a research and describes the presence of lead in coal, in deposits of ore, in peat bogs, or in lake and flood sediments. The second part briefly describes the analythic methods used to determine lead in natural material. The third - practical part is focused on measurement of samples taken from the sokolov brown coal basin. It describes the laboratory method of the preparation of the samples for the analysis of contents and isotope composition of lead using ICP - QMS.
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Distribution of sulfur isotopes in peat bogs
Haluzová, Eva ; Mihaljevič, Martin (advisor) ; Zachariáš, Jiří (referee)
The goal of this barchelor thesis is to describe the influence of human activity to sulphur cycle and monitoring processes and changes in this cycle with the assistance of specific sulphur isotopes. The first part describes sulphur and its compounds, then appearence in environment and its total cycle. The next part is focused on specific sulphur isotopes and thein application in studies of soils and peats. The final part summarizes total results and informations of human activity and it's influence on the sulphur cycle.
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Mineralogical speciation of the radium isotopes in Karlovy Vary hot spring sediments: Results of the selective dissolution
Supiňková, Taťána ; Goliáš, Viktor (advisor) ; Smrček, Stanislav (referee)
Thermal waters in Karlovy Vary are characterized by carbonate sedimentation in places of their emergence. These sediments contain radium. Radium bond in every type of sinter (aragonite, calcite) has been investigated experimentally by acid sinter dissolution. It has been found out, that radium can join dissoluble fraction in both sinter types . The original hypothesis that radium can bond only aragonite-type of sinter has been refuted. Additional experiments have been processed using synthetic radiobarite. Present radium in radiobarite can be partly dissoluted using acids. If radium was incorporated in radiobarite (it is known from locality Vřídlo in Karlovy Vary and elsewhere) then maybe it would be partly dissoluted in experiments.
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Distribution of sulfur isotopes in peat bogs
Haluzová, Eva ; Mihaljevič, Martin (advisor) ; Zachariáš, Jiří (referee)
The goal of this barchelor thesis is to describe the influence of human activity to sulphur cycle and monitoring processes and changes in this cycle with the assistance of specific sulphur isotopes. The first part describes sulphur and its compounds, then appearence in environment and its total cycle. The next part is focused on specific sulphur isotopes and thein application in studies of soils and peats. The final part summarizes total results and informations of human activity and it's influence on the sulphur cycle.
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Variation of Pb-isotopic composition in coal basins
Čurda, Michal ; Strnad, Ladislav (advisor) ; Mihaljevič, Martin (referee)
This Bachelor Thesis is devided into three main parts. The first part has a character of a research and describes the presence of lead in coal, in deposits of ore, in peat bogs, or in lake and flood sediments. The second part briefly describes the analythic methods used to determine lead in natural material. The third - practical part is focused on measurement of samples taken from the sokolov brown coal basin. It describes the laboratory method of the preparation of the samples for the analysis of contents and isotope composition of lead using ICP - QMS.
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Ionizing radiation in material testing
VLNA, Zdeněk
It this bachelor thesis deals with the use of ionizing radiation in engineering practice. Analyzes various options for screening, depending on technical parameters and the isotope used. It contains a description of special types of X-ray equipment, X-ray lamp and isotopes used in practice and we can find a detailed procedure for gammamat and X-ray lamp. The protection against ionizing radiation is mentioned at the end and ionizing radiation sensor used in the field are listed.
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