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Black carbon measuruments comparison
Vítová, Jana ; Zíková, Naděžda (advisor) ; Vondráková Pokorná, Petra (referee)
This thesis focuses on comparing three devices designed for measuring equivalent black carbon (referred to as eBC - equivalent black carbon), specifically the MAAP instrument (Multi-Angle Absorption Photometer) model 5012, the Aethalometer model AE33, and a semi-continuous analyzer of organic and elemental carbon. The instruments collected eBC concentrations at the Institute of Chemical Process Fundamentals of the Czech Academy of Sciences (Ústav chemických procesů AV ČR, v.v.i.) in the northwest of Prague from October 4, 2021, to September 30, 2022. Initially, total eBC concentrations were compared between all mentioned instruments using the non-parametric Wilcoxon test. Subsequently, daily, weekly, and annual variations in BC were determined. Finally, values of the Ångström absorption coefficient, mass absorption cross section (MAC), and harmonization factor C, which had not been determined for the mentioned measurement area, were calculated. For all instruments, a mutual agreement was found, confirmed by correlation coefficients: AE33 and MAAP with r=0.88, AE33 and OC/EC with r=0.83, and MAAP and OC/EC with r=0.76. The coefficients of determination between individual instruments were also obtained: AE33 and OC/EC with Rš=0.68, OC/EC and MAAP with Rš=0.57, and AE33 and MAAP with Rš=0.77. The...
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Anthracological analysis of chernozems in Czechia
Danková, Lenka ; Šefrna, Luděk (advisor) ; Zádorová, Tereza (referee)
This thesis deals with a pedogenesis of chernozems in Czechia (Central Europe). It solves a problem with open landscapes in Central Europe, further a role of man and fires in formation of this soils and relation between colour of chernozems and the content of black carbon. In my thesis is represented pedoanthracology as a method, which can be useful for future study of open landscapes in Central Europe and for an influence of man. In this thesis, there were also analysed two chernozemic soils with Raman spektrometry. It was found out, that chernozems was probably formed under forest-steppe vegetation with residue of post glacial steppe. Anthropogenic activity and fires could be new factors of pedogenesis of Central European chernozems. It was showed a strong relation between colour and content of BC. Raman spectrometry found a presence of BC in our analysed soils.
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Anthracology and NMR spectroscopy in Palaeoecological Research of Chernozems
Danková, Lenka ; Šefrna, Luděk (advisor) ; Chuman, Tomáš (referee)
This thesis deals with black carbon, its characteristic features and with its occurrence in chernozemic soils. In particular, this thesis deals with methods, which can study presence of black carbon in soils. The presence of black carbon and the whole composition of soil organic matter of three chernozemic soils in Czechia (Zeměchy, Tursko, Syrovice) is examined by 13 C NMR spectroscopy. Anthracological analysis of charcoal from fossil chernozems of Zemechy loess ravine deals with pedogenesis of chernozems and development of Quaternary vegetation in Central Europe. Coniferous tree species of Pinus sp., Pinus cf. cembra, Larix/Picea, Juniperus a Vaccicium, i.e. cold- and drought-tolerant taxa, were identified by anthracological analysis of soils of Zemechy loess ravine. The identified species suggest that the landscape around Zemechy was probably formed by parkland taiga. According to 13 C NMR spectroscopy, soil organic matter of fossil chernozem of Zemechy loess ravine consists particularly of alkyl and O-alkyl carbon. Aromatic carbon is also significant. O-alkyl carbon is the most important in the recent chernozems of Tursko and Syrovice. Aromatic carbon has the smallest proportion in both chernozems. The presence of aromatic carbon in chernozem of Tursko is the smallest of all analyzed soils. The...
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Microstructure of carbon black nanomaterials studied by X-ray scattering
Machovec, Petr ; Dopita, Milan (advisor) ; Horák, Lukáš (referee)
Název práce: Studium mikrostruktury uhlíkových nanomateriálů pomocí rentgenové difrakce Autor: Petr Machovec Katedra: Katedra fyziky kondenzovaných látek Vedoucí bakalářské práce: RNDr. Milan Dopita, Ph.D., Katedra fyziky kondenzovaných látek Abstrakt: Předkládaná práce se zabývá studiem mikrostruktury, struktury a reálné struktury turbostratického uhlíku a uhlíkových nanotrubic pomocí metod rozptylu rentgenového záření. Klastry turbostratického uhlíku jsou popsány pomocí sady fyzikálních parametrů. Pomocí počítačových simulací je popsán vliv těchto parametrů na výslednou rozptylovou křivku. Dále je předkládán popis dvou typů uhlíkových nanotrubic a je popsán vliv typu a rozměrů uhlíkových nanotrubic na výslednou rozptylovou křivku. Pro experimentální část práce byla připravena série vzorků turbostratického uhlíku žíhaného při teplotách 300℃, 600℃, 800℃, 1000℃, 1200℃, 1400℃ a 1800℃. Pomocí maloúhlového rozptylu rentgenového záření byla určena velikost nanočástic a jejich rozdělení, velikost mikropórů, specifický povrch a dimenze povrchového fraktálu. Další fyzikální parametry jako velikosti a rozdělení velikostí klastrů La a Lc turbostratické uhlíku, mřížové parametry a a c a střední kvadratické výchylky atomů ve směru grafenových vrstev a ve směru kolmém byly určeny z širokoúhlových rentgenografických...
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ESA of the old charcoal kiln
Macounová, Kristina ; Šefrna, Luděk (advisor) ; Strouhalová, Barbora (referee)
The topic of this dissertation is the assessment of the black carbon in the soil. The soil samples were collected in the Brdy area. Relics of charcoal kilns from the 17th - 18th centuries occur there in some places. A part and parcel of this paper is the literature search of the black carbon in the soil, of the history of burning charcoal and of the general characterization of the site where the terrain measurements were in progress. The measuring specification is a part of this paper, too. The results showed changes of physical and chemical characteristics between original forest soils and soils enriched by the black carbon. These soils in the beech forest showed approximately pH 4,7, while soils in the spruce forest showed pH 3,7 on the average. Original soils in the beech forest were more acid by 1 pH unit, and the original soils in the spruce forest were by 0,3 pH more acid. The bulk density of the original soils was 1,28 g/cm3 on the average, and the soils enriched by black carbon decreased to 0,68 g/cm3 on the average. Key words: coal kiln, Brdy, Black carbon, Elementary soil area
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Anthracology and NMR spectroscopy in Palaeoecological Research of Chernozems
Danková, Lenka ; Šefrna, Luděk (advisor) ; Chuman, Tomáš (referee)
This thesis deals with black carbon, its characteristic features and with its occurrence in chernozemic soils. In particular, this thesis deals with methods, which can study presence of black carbon in soils. The presence of black carbon and the whole composition of soil organic matter of three chernozemic soils in Czechia (Zeměchy, Tursko, Syrovice) is examined by 13 C NMR spectroscopy. Anthracological analysis of charcoal from fossil chernozems of Zemechy loess ravine deals with pedogenesis of chernozems and development of Quaternary vegetation in Central Europe. Coniferous tree species of Pinus sp., Pinus cf. cembra, Larix/Picea, Juniperus a Vaccicium, i.e. cold- and drought-tolerant taxa, were identified by anthracological analysis of soils of Zemechy loess ravine. The identified species suggest that the landscape around Zemechy was probably formed by parkland taiga. According to 13 C NMR spectroscopy, soil organic matter of fossil chernozem of Zemechy loess ravine consists particularly of alkyl and O-alkyl carbon. Aromatic carbon is also significant. O-alkyl carbon is the most important in the recent chernozems of Tursko and Syrovice. Aromatic carbon has the smallest proportion in both chernozems. The presence of aromatic carbon in chernozem of Tursko is the smallest of all analyzed soils. The...
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Anthracological analysis of chernozems in Czechia
Danková, Lenka ; Zádorová, Tereza (referee) ; Šefrna, Luděk (advisor)
This thesis deals with a pedogenesis of chernozems in Czechia (Central Europe). It solves a problem with open landscapes in Central Europe, further a role of man and fires in formation of this soils and relation between colour of chernozems and the content of black carbon. In my thesis is represented pedoanthracology as a method, which can be useful for future study of open landscapes in Central Europe and for an influence of man. In this thesis, there were also analysed two chernozemic soils with Raman spektrometry. It was found out, that chernozems was probably formed under forest-steppe vegetation with residue of post glacial steppe. Anthropogenic activity and fires could be new factors of pedogenesis of Central European chernozems. It was showed a strong relation between colour and content of BC. Raman spectrometry found a presence of BC in our analysed soils.
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