National Repository of Grey Literature 25 records found  1 - 10nextend  jump to record: Search took 0.02 seconds. 
The Combustion of Organic Lightweighting Agents in the Chamotte Materials
Smékalová, Veronika ; Keršner, Štěpán (referee) ; Sokolář, Radomír (advisor)
Lightweight chamotte products are popular building material. There are many types of lightweight chamotte on the market, but the most popular lightening options are organic ingredients. This brings some problems to the production of these products. This thesis deals with the burning of various types of lighters from shards of fireclay materials. In the theoretical part are summarized raw materials, which are necessary for production of lightweight chamotte. The results of the published research studies on the topic of lightening of organic lightening products are being described here. The practical part deals with properties of products made of clay or kaolin with the addition of a certain amount of lighter. These added lighters are spruce sawdust, beech sawdust, peat, bran, paper slurry and anthracite. All these lighters are direct. For comparison, the cenospheres, which represent indirect lightweights, were also included in the research. For all specimens, the temperature interval of burnout of specimens, refractoriness, classification temperature, bulk density, thermal conductivity coefficient and other properties were defined.
Fosil Fuels in Czech Republic
Ertelt, Tomáš ; Moskalík, Jiří (referee) ; Baláš, Marek (advisor)
The object of this bachelor thesis is to explore fossil fuels in the Czech Republic their kinds, qualities, occurrence, usage, extraction, import and export. Thesis focuses on black coal, brown coal, anthracite, lignite, peat, oil and natural gas. This thesis analyzes their availability, deposits, processing and usage in the Czech Republic. Production statistics of their extraction by 2011 are addend.
Molecular study of lipids in humic acids by sequential chemical degradation
Bachratá, Radka ; Grasset, Laurent (referee) ; Klučáková, Martina (advisor)
Lipidy v půdě vykazují poměrně vysokou resistenci k biodegradaci, mohou proto tak zajistit informace o zdrojích organické hmoty a diagenetických procesech. Půdní organická hmota je vysoce heterogenní a vyskytují se v ní různé dynamické systémy. Vztahy mezi těmito systémy a molekulární strukturou ještě nejsou úplně známy. Analýza lipidů a bitumenu byla provedena u dvou vzroků (rašelina a lignit). Množství skupin sloučenin (volné uhlovodíky a volné ketony, vázané alkoholy, vázané mastné kyseliny, vázané -hydroxy kyseliny, volné dikyseliny a polycyklické sloučeniny) bylo idetifikováno pro oba vzorky a jejich distribuce byly určeny. GC/MS analýza volných a vázaných lipidů zjistila jejich různé zdroje během chemické degradace. Některé podobné znaky mohou být znakem uchovávání části vosků a suberinu z vyšších rostlin (dlouhé řetězce vázaných mastných kyselin). Velké rozdíly v molekulárním složení lipidů byly pozorovány mezi vzorky, dokládající význam studia lipidů z mladého sedimentu (rašelina) a starého (lignit).
Characterization of peat
Freithová, Štěpánka ; Mikšík, František (referee) ; Kotlík, Josef (advisor)
Peatlands are considered to be valuable ecosystems on the Planet and play an important role in many processes globally likewise and in the landscape. They are important for maintaining a global biodiversity, play an important role in landscape hydrology and can be a source of drinking water. They can help minimize floods and contribute to climate change mitigation. The peat bogs are one of the largest terrestrial carbon reservoirs. They have been storing carbon for centuries. Many of peat functions are affected due to human activities. It can result into release of greenhouse gases into atmosphere and the excretion of organic carbon into watercourses. The subject of the thesis is understanding of the mechanisms of water binding in peat and exploring possible dependencies within the depth profile of the peatlands using thermal analytical methods, more preciously using thermogravimetry (TG) and differential scanning calorimetry (DSC). The stability of water molecule bridge (WaMB) was investigated. It was found out that the minimum temperature required for WaMB abatement decrease and the whole structure becomes less stable with increasing peat layer depth. Water release processes were evaluated with the meaning of the TGA measurements. A decreasing trend in the degradation of thermolabile substances and an increasing trend in thermostable substances within the peat profile were observed.
Evapotranspiration of peat soils
Urbánková, Karolína ; Weiss, Tomáš (advisor) ; Šípek, Václav (referee)
The correct determination of evapotranspiration is critical for the calculation of the water balance. Although research on evapotranspiration in general is already quite advanced, peat soils are so specific that they may require their own unique approach. Hydrologists have a series of calculations and models to determine evapotranspiration, but these are not always sufficiently accurate, especially at higher temperatures. The aim of this thesis was to summarise the existing knowledge of evapotranspiration in peat soils and to determine whether the peat layer thickness has an effect on peat evaporation. The thesis presents a survey of methods for determining evapotranspiration that can be applied to peat soils. The laboratory experiment used a split container, one part of which contained peat and the other part had peat only in the top 7 cm, with quartz sand underneath. The two parts were joined at the bottom with gravel and thus permeable to water. The trend of water loss, soil water potential and soil moisture was monitored. Preliminary results show that peat strength has a clear effect on evaporation. Further research would, among other things, look for a specific height of the peat layer for which the underlying material would no longer have an effect. Key words: evapotranspiration, peat,...
Vliv huminových kyselin na vybrané půdní charakteristiky
KLENOTOVÁ, Eva
Humic substances, especially humic acids, are classified among the so-called soil auxiliary substances that positively affect the quality of the soil. As part of the diploma thesis, humic acids were isolated from these sources. Their influence on selected soil characteristics was investigated, particularly the carbon content in different size fractions and the number of water-resistant macroaggregates. The experiment was conducted in the form of pot vegetation experiments. It was found that the highest content of organic carbon contained leonardite. On the contrary, the smallest amount was found in the compost. The influence of humic acids on the formation of macroaggregates was demonstrated by the method of dry and wet sieving. The best effects were achieved when humic acids from leonardite and peat were applied. In all variants of wet sieving, vegetation had a positive impact on the macroaggregate formation, which may result from the synergistic effect of humic acids and the activity of plant roots.
Změny půdních vlastností a šíření původních rostlinných druhů v odvodněných rašeliništích po revitalizaci jejich vodního režimu
VÁVROVÁ, Magdaléna
This Bachelor Thesis summarizes the knowledge about peatlands, their drainage, mining and restoration. It is focused on changes of soil characteristics after peatland drainage and restoration, on the effect of changingsoil properties on the native peatland vegetation and its spreading after restoration. The thesis includes a project proposal which aim is to support the spreading of native plant species on the mined bog after restoration of its water regime.
From the history of mining, processing and the use of peat in South Bohemia in the 20th century
PETRÁŠEK, Karel
The thesis describes the development of peat industry history in the South Bohemian region against the background of economic history from the beginning of the 20th century up to year 1960. The author divided the text into three main sections. The first one defines the significance of peatbogs to the landscape and analyzes the development of their legal protection. It also includes the general development of peat industry in several European countries, the basis of which is used as a collation to the situation in the territory of Czechoslovakia. The second part covers the analysis of South Bohemian peat industry in the first half of the 20th century. Based on the examples taken from a series of extractive areas and a wide range of archives, the author illustrates the differences in the raw material perception, extraction approaches and management, and the daily life of workers. From these findings, general conclusions are drawn, aiming at creating a comprehensive image of the situation. The last chapter focuses on the analysis of the influences that the changing postwar situation in the politics and economy had over the peat production. The changes which affected the peat industry in the 50s of the 20th century are drawn on the fortunes of particular sole traders and peat works. These took the position of the small businessmen as the only producers of the raw material in Czechoslovakia for the rest of the century.
Comparison of oxyhumolite of the Sokolov basin with materials which are using in spa and alternative medicin and its possible usage in these spheres
Dúcka, Barbora ; Rojík, Petr (advisor) ; Goliáš, Viktor (referee)
This work deal with a brief characterization of three materials, namely oxyhumolite and sapropelite from Sokolov basin that are compared with peat from Františkovy Lázně. The sampling localities are briefly geographically and geologically described including the genesis of the deposits. All materials are specifically characterized by analysis. The materials are compared based on the results of the analysis. Greater attentinon is paid to the comparison of sulfur content, humic acides and warmth retention. A part of the work is devoted to description of peloids and their influence on the human organism. The history of using peloids is briefly discussed. The possibility of using oxyhumolite and sapropelite for production of natural cosmetics or for balneological use is examined as a replacement for native and especially for regenerated peat.
Tree rings and peat bogs as archives of recent trends in Pb and Hg deposition in the Czech Republic
Zuna, Milan ; Mihaljevič, Martin (advisor) ; Komárek, Michael (referee) ; Soudek, Petr (referee)
1 Tree rings and peat bogs as archives of recent trends in Pb and Hg deposition in the Czech Republic Milan Zuna, 2012 Abstract The environment polluted by toxic metals is currently one of the most topical subjects studied in a great many countries. Toxic metals and their forms are studied primarily because of their negative impact on the environment and also on human health. In the territory of the Czech Republic, direct measurements of the concentrations of these substances are available only for a limited time period. Consequently, indirect methods, such as geochemical archives, are used to determine the historical environmental burdens from these metals. Historical lead concentrations (Pb) were studied on peat bog profiles and tree rings in selected localities in the Czech Republic. Altogether 12 peat bog profiles and 33 wood cores (Picea abies) were studied, in the border territories of the Czech Republic with different historical burdens (Krušné Hory - Novodomské rašeliniště - ND, Jizerské hory - Bílá Smědá - BS, Šumava - Jezerní slat - JS), and in a historically burdened area polluted by processing of Pb- Ag ores (Příbram-Brdy). In the vicinity of Příbram, areas around the Brdy ridge (9 km east of the Pb metallurgical works) as well as in the immediate vicinity of the metallurgical works. We used the...

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