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Creation of Database and Classification of Diatoms
Svoboda, Jan ; Nötzel, Ralf (referee) ; Drahanský, Martin (advisor)
Výsledná aplikace pracuje s vytvořenou databází, obsahující obrázky jednotlivých rozsivek a informace o nich uložené v XML dokumentu. Nad touto databází jsou zajištěny základní operace přidávání, úpravy, mazání a vyhledávání. Vyhledávání může probíhat třemi způsoby, a to pomocí textových vstupů, obrázkových vstupů nebo jejich kombinací. Algoritmus vyhledávání pomocí obrázkových vstupů se snaží najít v databázi co nejpodobnější kandidáty s ohledem na tvar a tloušťku schránky rozsivky a na vnitřní strukturu rozsivky jako takové. Toto vyhledávání je nejčastěji znepřesněno kvalitou pořízených snímků, či obrázků porovnávaných rozsivek. Program obsahuje přehledné a intuitivní grafické rozhraní, jež nám pohodlně umožňuje prohlížet stávající databázi a provádět operace nad ní s možností nastavení filtrovacích hodnot při vyhledávání.
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Effect of partial replacement of Portland cement by diatomaceous earth on selected parameters of cement mortar
Rousková, Jana ; Sedlmajer, Martin (referee) ; Rovnaníková, Pavla (advisor)
The subject of this thesis is selected parameters cement mortars with partial replacement of Portland cement diatomaceous earth. This work provides information on the basic properties of diatomaceous earth and its deposits with a focus on deposit in Borovany. From the properties is very important pozzolanic activity due to the high content of amorphous silica of this soil. The main use of diatomaceous earth is in the area filtration and is used widely as a nutritional supplement. In the building industry, diatomite can be applied as an admixture to mortar and concrete, where it can, with its abilities, improve some physical mechanical properties. In the experimental part was diatomaceous earth, in its raw and calcined form, tested as admixture for cement pastes and mortars. The main criterion for evaluating these composites was bulk density, flexural and compressive strength. It was also investigated mineralogical composition, microstructure, freeze–thaw resistance and sulfate resistance.
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Molecular variability and distribution of the Frustulia rhomboides species complex (Bacillariophyceae)
Urbánková, Pavla ; Kulichová, Jana (advisor) ; Bešta, Tomáš (referee)
Recent use of molecular methods to revisit taxonomically problematic diatom species revealed severe limitations of morphological species concept. Characterization of diatom species which was based solely on the morphology of their frustules often generated too broad species boundaries which inevitably lead to wrong conclusions about their ecology and distribution. Widespread opinion that many diatom species are cosmopolitan generalists resulted in a theory that dispersal of diatoms is not limited by geographical distance. However, a number of recent studies showed that dispersal of diatoms is governed by the same rules which matter for macroorganisms. Proposed master thesis addresses the topic of diversity and dispersal in diatom species complex Frustulia rhomboides sensu lato in Europe and New Zealand. Results suggest that: (1) although revealed molecular variability in this complex shows clear ecological and biogeographical signal, it is not correlated in morphology. This is another support to general need for adoption of different species concept in diatoms. (2) A considerably uneven ratio in species diversity of genus Frustulia found in ecological similar habitats in Europe and New Zealand supports the idea that diatom dispersal is limited and stressed the need for studies dealing with biogeography.
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In vivo study of diatom assemblages using low temperature method for ESEM
Tihlaříková, Eva ; Neděla, Vilém ; Fránková, Markéta
Diatoms are the most species-rich algal group represented by 12 000 described species and are recognized as powerful bio indicators and used for water quality monitoring. Diatom taxonomy is predominantly based on the morphology of ornate silicified cell wall called frustule composed of two overlapping parts (thecae). This frustule displays intricate patterns and designs unique to each species. For these studies conventional scanning electron microscopy (SEM) was and still is widely used. This method requires cleaning of diatom frustules in strong acids and peroxides followed by conductive coating.This aggressive procedure removes protoplast and damages delicate structures. Environmental scanning electron microscopy (ESEM) brings advantages of observation of fresh diatom material that are presence of whole intact diatom cells, not only empty diatom frustules, extracellular mucilaginous diatom secrets (e.g. pads, stalks, tubes) and whole diatom assemblages directly in situ together with other algal assemblages (e.g. cyanobacteria or green algae). However, in diatom research, ESEM is used mainly for elimination of conductive coating and observation of these organisms in their native wet state adhered directly on the host plant is not yet common. The ESEM observation of native aquatic samples is usually affected with radiation damage that can be lovered by the use of special methods like the Low Temperature Method (LTM) for the ESEM.
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Molecular variability and distribution of the Frustulia rhomboides species complex (Bacillariophyceae)
Urbánková, Pavla ; Kulichová, Jana (advisor) ; Bešta, Tomáš (referee)
Recent use of molecular methods to revisit taxonomically problematic diatom species revealed severe limitations of morphological species concept. Characterization of diatom species which was based solely on the morphology of their frustules often generated too broad species boundaries which inevitably lead to wrong conclusions about their ecology and distribution. Widespread opinion that many diatom species are cosmopolitan generalists resulted in a theory that dispersal of diatoms is not limited by geographical distance. However, a number of recent studies showed that dispersal of diatoms is governed by the same rules which matter for macroorganisms. Proposed master thesis addresses the topic of diversity and dispersal in diatom species complex Frustulia rhomboides sensu lato in Europe and New Zealand. Results suggest that: (1) although revealed molecular variability in this complex shows clear ecological and biogeographical signal, it is not correlated in morphology. This is another support to general need for adoption of different species concept in diatoms. (2) A considerably uneven ratio in species diversity of genus Frustulia found in ecological similar habitats in Europe and New Zealand supports the idea that diatom dispersal is limited and stressed the need for studies dealing with biogeography.
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Effect of partial replacement of Portland cement by diatomaceous earth on selected parameters of cement mortar
Rousková, Jana ; Sedlmajer, Martin (referee) ; Rovnaníková, Pavla (advisor)
The subject of this thesis is selected parameters cement mortars with partial replacement of Portland cement diatomaceous earth. This work provides information on the basic properties of diatomaceous earth and its deposits with a focus on deposit in Borovany. From the properties is very important pozzolanic activity due to the high content of amorphous silica of this soil. The main use of diatomaceous earth is in the area filtration and is used widely as a nutritional supplement. In the building industry, diatomite can be applied as an admixture to mortar and concrete, where it can, with its abilities, improve some physical mechanical properties. In the experimental part was diatomaceous earth, in its raw and calcined form, tested as admixture for cement pastes and mortars. The main criterion for evaluating these composites was bulk density, flexural and compressive strength. It was also investigated mineralogical composition, microstructure, freeze–thaw resistance and sulfate resistance.
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Creation of Database and Classification of Diatoms
Svoboda, Jan ; Nötzel, Ralf (referee) ; Drahanský, Martin (advisor)
Výsledná aplikace pracuje s vytvořenou databází, obsahující obrázky jednotlivých rozsivek a informace o nich uložené v XML dokumentu. Nad touto databází jsou zajištěny základní operace přidávání, úpravy, mazání a vyhledávání. Vyhledávání může probíhat třemi způsoby, a to pomocí textových vstupů, obrázkových vstupů nebo jejich kombinací. Algoritmus vyhledávání pomocí obrázkových vstupů se snaží najít v databázi co nejpodobnější kandidáty s ohledem na tvar a tloušťku schránky rozsivky a na vnitřní strukturu rozsivky jako takové. Toto vyhledávání je nejčastěji znepřesněno kvalitou pořízených snímků, či obrázků porovnávaných rozsivek. Program obsahuje přehledné a intuitivní grafické rozhraní, jež nám pohodlně umožňuje prohlížet stávající databázi a provádět operace nad ní s možností nastavení filtrovacích hodnot při vyhledávání.
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Diatoms of Acadia National Park, Maine, USA, with a detailed account on taxonomy and morphology of several remarkable species
VESELÁ, Jana
This thesis was focused on studying diatoms (Bacillariophyceae) from Acadia National Park, Maine, USA. First, the park is introduced and the preliminary study of freshwater algae, including diatoms, is presented. Extraordinary species richness of algae was discovered, especially in the group of diatoms, which is documented by a complete list of 674 diatom taxa in 92 genera encountered in the freshwater and brackish habitats within the park. Of those a considerable number of species unfortunately remained unidentified, as they did not conform to any described taxon in the available scientific literature. Therefore, several of those unnamed taxa were studied in close detail using light and scanning electron microscopes, exhaustive literature and herbaria search, and yielded description of three new species from genus Eunotia, and rediscovery of two rare and almost forgotten Surirella species.
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