National Repository of Grey Literature 29 records found  1 - 10nextend  jump to record: Search took 0.01 seconds. 
Influence of the mineralogical composition of raw material on phases formed during the burning of hydraulic lime and natural cement
Kozlovcev, Petr ; Přikryl, Richard (advisor) ; Hladil, Jindřich (referee) ; Škvára, František (referee)
Natural hydraulic lime and natural cement have been used in the building industry for centuries. These inorganic hydraulic binders are called "traditional" or "alternative" because they can, in some cases, substitute modern Portland cement. The recent increased interest in these binders is due not only to their use in restoration practices, but also because their production and use is less energetically demanding than in modern cements. Historically, many types of hydraulic binders were produced in the regions of Bohemia and Moravia. However, much information has been lost about their manufacturing process, which raw materials were used, and we are uncertain of the exact character and properties of the burned material. To date, studies have only addressed the impact of the chemical composition of raw material on the parameters of the burned material - all this is well known for Portland cement, much less for other types of hydraulic binders. The aim of this dissertation was to study the various types of raw materials (limestone containing non- carbon admixtures) and to understand the characteristics of their respective hydraulic lime and natural cement. This was done by analyzing the impact of conditions (highest achieved burning temperature and time of burning) and the mineral and chemical...
Paleoenvironmental record of carboniferous lacustrine deposits of central and western Bohemian basins: analysis and korealiton of mineral and biogenic proxies
Lojka, Richard ; Hradil, David (advisor) ; Hladil, Jindřich (referee) ; Janočko, Juraj (referee)
Ph.D. thesis represents summary of multidiciplinary palaeoenvironmental and palaeoclimatic research of the most significant Late Pennsylvanian lacustrine horizon of the central and western Bohemian basins - the Malesice Member of the Slaný Formation. Two cores from new shallow drills, situated 80 km apart, were analysed. Multidisciplinary approach is based on description of lamination structure and periodicity; mineral and isotopic composition of autigennic carbonates, namely siderite; compositiona of detrital minerals including clay mineral assemblages; and composition of autochthonous and allochthonous organic particles including palynospectra. Detailed analysis of drill cores lead to the identification of individual phases of lake development linked with lake-level fluctuation and water-column stratification, which were driven by a sume of precipitation and its seasonal distribution. Changes in precipitation also affected compostion and density of vegetational cover in the lake surroundings, weathering intesity of source rocks and degradation of organic matter in the drainage basin, and so precipitation affected final grain-size and composition of detrital material deposited in the lake. Beside common environmental signatures at both studied sites, there are also significant...
The record of sea-level changes, water circulation and sediment dispersion in the Upper Turonian hemipelagic strata of the Bohemian Cretaceous Basin
Hrnková, Magdalena ; Laurin, Jiří (advisor) ; Hladil, Jindřich (referee)
The Bohemian Cretaceous Basin was a sediment accumulation, which was deposited as an integral part of the central European epicontinental sea during the Late Cretaceous sea level highstand. It acted as a marine strait and was suited for preserving both nearshore coarse- clastic successions and hemipelagic deposits, allowing for the study of interplay between tectonics, eustatic sea level and paleoceanographic conditions. While the north-western part of the basin was extensively studied in the recent years, little information has yet been collected about the coeval along-shore environments. This thesis is aimed at bringing a new insight into these fine-grained deposits through a detailed lithological, multiproxy and time-series analysis investigation of the Late Turonian record in the Bch-1 drill core, Běchary, Czech Republic. The secular onset of carbonate-rich hemipelagic sedimentation coeval to the base of Teplice Formation is characterised by increased micrite content and changes in geochemical proxies, which are interpreted as changes in the pathway of clay distribution and silt source proximity, combined with elevated bioproductivity. Three orders of statistically significant variability were identified by time-series analysis of selected geophysical properties, two of which are carrying the...
The basic composite section in the Barrandian Lower Devonian succession of the beds using magnetic susceptibility stratigraphy
Koptíková, Leona ; Hladil, Jindřich (advisor) ; Kapička, Aleš (referee) ; VerStraeten, Charles (referee)
The composite reference section in the Lower Devonian succession was established using the magnetic susceptibility (MS) and gamma-ray spectrometric (GRS) logs from 5 sections representing both deep- and shallow-water environment of carbonate slope systems in the Prague Synform. Both background data and data across the boundaries of geological units or event intervals were acquired with the emphasis on obtaining continuous data series. Such a complex, detailed and multidisciplinary data set (petrophysical, lithological, mineralogical and geochemical parameters) has never been collected here. They were linked to the existing biostratigraphical scales and offer complex information for interregional and global correlations now with the precision of a few centimetres, which is a resolution 10 to 100 fold higher than in any established biostratigraphic scale in the Devonian of the Prague Synform. Major changes in the MS, GRS logs and mineralogy concentrate to the proximity of the Lochkovian-Pragian boundary (close to the Lochkov-Praha Fm. boundary). At this level, a reversal point in Th/U ratios is observed (dominant Th concentrations in the Praha Fm. vs. dominant U concentrations in the underlying Lochkov Fm. and overlying Zlíchov Fm. There is a general transgressive trend for the Lochkov and Praha Fm....
Towards the Structures of the Carbonate Beds Rapidly Deposited from High-Density Suspensions: Experiments with Five Fractions of Angular Grains in a Settling Column
Kulaviak, Lukáš ; Hladil, Jindřich ; Růžička, Marek ; Chadimová, Leona ; Slavík, Ladislav
Two parallel series of experiments were run, one with differently coloured fractions and other with colourless fractions. First approach provided an easier visualization on particle distribution in the sediment using image analysis whereas the second helped to better identify the voids. Copmprehensive sets of results are illustrated in the poster. They provide another clue to understanding the different vertical successions and inner structures in these specific, event deposited beds.
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Structure of Sedimentary Calcite
Kulaviak, Lukáš ; Hladil, Jindřich ; Růžička, Marek ; Drahoš, Jiří ; Saint-Lary, L.
Our contribution exhibits experimental results of the structure of calcite deposit that origins by a collective sedimentation of the mixture of variable large particles in liquid. The work is aimed to find for which conditions, concerned of particle dispersity, raises the group of special, large cavities (stromatacta).
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