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The modification of the graphene structures by low energy ions (E
Maniš, Jaroslav ; Čermák,, Jan (referee) ; Mach, Jindřich (advisor)
Diploma thesis deals with the influence of low energy ions on graphene structures. Graphene structures were modified by nitrogen and argon ions of energies lower than 100 eV. Modified structures were analysed by Raman spectroscopy and x-ray photoelectron spectroscopy. The influence of the dose of ions on quality of graphene were investigated as well. In addition, this diploma thesis includes the literature search which focuses on modification of graphene by charged particles.
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Expanded Grpahite as Negative Electrode Material for Aporotic Intercalation Systems
Kaňa, Michal ; Čech, Ondřej (referee) ; Libich, Jiří (advisor)
This thesis deals with lithium-ion batteries. It focuses primarily on the materials which are the basis of negative electrode materials, especially on natural expanded graphite. The aim of this thesis is delineate problems of lithium-ion batteries and the possibilities how to improve their basic parameters such a capacity and current carrying capacity. The first part focuses on the description of the functionality of a lithium-ion battery. The second part focuses on the production of negative electrodes, measuring their properties and characteristics. In the last part, there are evaluated and compared individual negative electrode in the role of host of lithium and sodium ions according to the obtained data and then there are the conclusions draw
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Porovnání množství vázaného uhlíku v nadzemní i podzemní biomase v různých typech využití půdy v okolí města Oxapampa, Peru
Chalupová, Karolína
The present work compares amount of sequestered carbon in different types of land use in the vicinity of Oxapampa in Peru. Research was conducted in the autumn of 2022 with focus on three main types of land use: coffee agroforestry plantations, montane tropical forests and silvopastoral systems. Data collection was carried out with Field-Map technology, where 47 study plots on 6 transects were compared. To estimate aboveground and belowground biomass allometric equations were used. The evaluation of soil carbon stocks was determined based on soil analysis using a Soli-TOC device (Elementar). The results showed that there was no statistically significant difference between the amount of carbon bound in the biomass of agroforestry coffee plantations and forest ecosystems. Soil carbon stocks were highest in forest stands in the upper soil layers. At lower depths (20–30 cm) the difference between the studied ecosystems was no longer registered. Average soil carbon values (%) for coffee agroforestry systems and particular depths were as follows: H (7,6 ± 3,8); 0–10 (5,1 ± 1,8); 10–20 (3,8 ± 0,8); 20–30 (3,4 ± 0,7). For study plots in forest ecosystems: H (34,2 ± 12,1); 0–10 (22,4 ± 14,7); 10–20 (9,5 ± 6,2); 20–30 (7,3 ± 5,8). Soil carbon stocks values for silvopasture systems were: H (12,1 ± 4,7); 0–10 (7,3 ± 3,3); 10–20 (5,3 ± 2,3); 20–30 (3,7 ± 2,1).
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Pedodiverzita vybraných ekotonů na přechodu lesní porost - palouk na území Školního lesního podniku Masarykův les Křtiny
Bydžovský, Radek
Ecotones and their environments are often referred to as areas of significant diversity that condition the interactions of neighbouring ecosystems. Manifestations of ecotone community diversity can be observed, for example in the species composition of flora and fauna. However, this bachelor thesis examines the characters of the soil environment of this ecosystem and compares it with enviroment of a forest and a meadow. Evaluated soil diversity parameters are active and potential soil reactions, soil catalase enzyme aktivity, C, N, S element content and possible carbonate content. The evaluation of these soil characteristics was carried out in the three selected sites. The significant dynamics of the ecotone environment was confirmed in the case of soil reaction. Catalase also showed different activity rates in the ecotone area. A similar finding was confirmed in the case of the analysed elements C, N and S. Based on the evaluated parameters, the ecotone area shows a significant different character of the soil environment. However, the character and degree of manifestation in ecotone area are very closely linked to the characteristics of the individual habitats.
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Změny v množství vázaného uhlíku v nadzemní biomase v lesní rezervaci Greenfields, Nikaragua
Dvořák, Vít
The aim of this study was to evaluate changes in the amount of carbon sequestered in the private reserve Greenfields, located in a tropical rainforest in Nicaragua. Two forest inventories were carried out (in 2015 and 2022), and from the obtained data, the biomass and the amount of sequestered carbon in the forested area of the Greenfields reserve were calculated. The data was then compared with the results of other similarly focused studies in the area, contextualized within biological succession, and finally, a financing system for the reserve was proposed through carbon trading payments.
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Aboveground litterfall fluxes of selected elements in central European temperate forest
Bašta, Jan ; Oulehle, Filip (advisor) ; Chuman, Tomáš (referee)
5 Abstract Aboveground litterfall is the most important intrasystem flow in the temperate forest ecosystem. It is also the largest input flux to the soil surface for most of the macronutrients (N, P, Ca, Mg, K). However, under Central European conditions, studies on the magnitude of this flux in relation to elemental stocks are lacking. GEOMON Small Forest Catchment Network is used to investigate long-term trends in nutrient cycles in temperate forests of Central Europe and the human influence on them. As part of this network aboveground litterfall collectors were placed in 14 catchments at a total of 19 sites at the end of 2019. Litterfall was then collected bimonthly, weighed and sorted into different fractions. These fractions were analyzed to determine the concentration of the elements of interest. From these values, the fluxes of the elements in the aboveground litterfall were calculated. The observed values were compared with the characteristics of the individual sites and the element budgets in the catchments. The monitored elements can be ranked according to the size of the flux of the element through the aboveground litterfall in relation to other inputs of that element to the soil as follows: C, P, N, Ca, Mg and K. The average amount of aboveground litterfall in the GEOMON network is 4.6...
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Soil carbon sequestration: ways and potential
Valentová, Mariana ; Vindušková, Olga (advisor) ; Bartuška, Martin (referee)
By choosing appropriate practices, carbon can be stored in the soil as a means of mitigating (mitigating) climate change. The paper clearly summarize our current understanding of the principles (e.g., soil organic matter, level of C saturation) anf factors (e.g., parent rocks, climate, human) influencing the potential of soils to sequester carbon and its importance in terms of implemeting effective mitigation measures. This is followed by an introduction of method for estimating the carbon sequestration capacity of soils and its relevance to sequestration potential is discussed. The main focus of the paper is the comparison of the land use changes (e.g., forest or peatlands restoration) and land management (e.g., use of crops rotation, no-till agriculture) that can achieve soil carbon sequestration, including the quantitative estimates of their sequestration potential. Finally, there is summary of the estimates of global sequestration potential of soils. Key words: carbon, soil, sequestration, mitigation, climate change, land-use, soil capacity
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Sequestration of soil organic matter in broadleaf and coniferous forests in soil at various stages of pedogenesis
Hüblová, Lucie ; Frouz, Jan (advisor) ; Vindušková, Olga (referee)
Soil organic matter (SOM) is an important component of the soil. SOM is responsible for availability of nutrients for plants and soil organisms, formation of soil structure and soils water-holding capacity. SOM is made up of organic matter (OM) of plant and animal origin at various stages of decomposition. SOM can be divided into several components called fractions. Fractions differ between each other in their resistance against decomposition. Main SOM fractions are: (1) free floating particulate organic matter (FPOM) and (2) OM bound to soil mineral surfaces in various ways (MAOM) - OH inside macro- and microaggregates and OM bound to silt and clay surfaces (S+C). It is assumed that MAOM fraction becomes C saturated during soil development and no more C can be sequestered in it. Other fractions, particularly FPOM, that are not dominant C storage in the initial stages of soil development become more important in the later stages and amount of C stored in them increases. However, there is scarcity of studies that examine this assumption. In this work I studied the hypothesis that soils in different stage of development will differ in the amount of C stored in different fractions. On top of that, this difference will be affected by the dominant tree species growing on the soil and the effect of tree...
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Development of grounding enhancing cement composite mixture
Sochor, David ; Dohnálek,, Pavel (referee) ; Drochytka, Rostislav (advisor)
The diploma thesis deals with the development of a conductive cement composite grounding mixture for protection of building structures in areas with low conductivity. The theoretical part is focused mainly on the methods of buildings protections against lightning and overvoltage. The aim of this is to create a conductive composite with the possible use of secondary raw materials, which have a low electrical impedance value. The conclusion of the thesis is devoted to the evaluation of the efficiency of newly designed conductive composites and their possibility of incorporation into building protection systems against lightning or overvoltage.
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Souvislost změn v cyklech dusíku a uhlíku v lesních půdách po odumření stromového patra
TUPÁ, Adéla
The bachelor's thesis deals with changes in nitrogen and carbon cycles in coniferous forest soils after tree layer dieback due to forest disturbance. The thesis focuses on changes in nitrification and availability of nitrates in soils in connection with microbial biomass and carbon availability, especially in the forests with non-intervention management. This thesis contains of two parts, a literature review, and a scientific project proposal, which aims to verify possible validity of heterotrophic-competition hypothesis of microbes in soils.
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