National Repository of Grey Literature 126 records found  1 - 10nextend  jump to record: Search took 0.00 seconds. 
Chemical analysis of organic residues in archaeological ceramic vessels
Bunžová, Aneta ; Mravcová, Ludmila (referee) ; Čáslavský, Josef (advisor)
The presented bachelor thesis deals with the analysis of organic residues in archaeological ceramic vessels. Apart from theoretical characterisation of residues, the thesis focuses on the possibility of the extraction of residues and subsequent analysis, which is executed on real samples from archaeological sites. In the research, two different derivatizational reagents were used for the subsequent determination using the technique of gas chromatography in combination with mass spectrometry (GC/MS). The thesis endeavours to certain extent to sketch the diet of the users of the analyzed ceramic vessels.
Analysis of biochar aqueous extracts by separation methods
Tučková, Dominika ; Čáslavský, Josef (referee) ; Mravcová, Ludmila (advisor)
This master's thesis deals with the analysis of biochar extracts by separation methods. All analyzed biochar was produced from waterworks sludge by microwave pyrolysis. The aim of the thesis is the optimization of the sample preparation method and its analysis in a laboratory environment. With the ever-growing world population, the problem of a sustainable economy in both agriculture and waste management is becoming increasingly urgent. This fact has led most countries to consider promoting the so-called Circular Economy. The use of sewage sludge as a feedstock for biochar production is perfectly in line with this strategy. So far, however, the short term and the long term benefits and risks of using biochar have not been sufficiently described. Potentially hazardous organic substances were extracted from the biochar extracts by three techniques: liquid-liquid extraction, solid-phase extraction, and solid- phase micro-extraction. The obtained samples were analyzed using the GS-MS/TOF method. The individual methods were compared. Several biochar samples from WWTP Brno and WWTP Drahovice were selected and analyzed to verify the suitability of the selected sample analysis method.
Regulation of Epithelial-Mesenchymal transition by the ERK pathway.
Čáslavský, Josef ; Vomastek, Tomáš (advisor) ; Brábek, Jan (referee) ; Gregor, Martin (referee)
Typical epithelium is uniformly polarized solid structure defined by the presence of cell-cell contacts that are connected to well-organized network of actin cytoskeleton. While epithelium is considered to be rather static, during embryogenesis or cancer development epithelial tissues undergo considerable dynamic changes in their integrity that are characterized by loss of epithelial polarity, disruption of cell-cell adhesions and gaining mesenchymal or mesenchymal-like migratory phenotype. These changes, collectively termed as epithelial-mesenchymal transition (EMT), allow cells to effectively invade surrounding tissues and are considered to be a main factor underlying the formation of metastatic cancer. The MAPK/ERK cascade, comprised of protein kinases Raf, MEK and ERK, induces the breakdown of epithelial integrity and cell autonomous migration in various cell lines. In the ERK pathway, ERK is an effector protein kinase which, depending on the cellular context, phosphorylates a number of different substrates. Spatiotemporal phosphorylation of specific constellation of ERK substrates drives specific biologic outcome. The question arises whether, during conversion of multicellular epithelium to autonomously migrating cells, ERK regulates a "master" controller or whether the ERK regulatory function...
Degradation of Heat Transfer Fluids in Thermal Solar Systems and Propane-1,3-diol as a New Option
Mikšík, František ; Professor, Takahiko Miyazaki, (referee) ; Skolil, Jan (referee) ; Tocháček, Jiří (referee) ; Čáslavský, Josef (advisor)
Stárnutí teplonosných kapalin na organické bázi je dlouhodobým problémem, který je znám od počátku jejich používání. První část této disertační práce je tak věnována případové studii funkčního experimentálního systému, který byl jako nový naplněn teplonosnou kapalinou na bázi propan-1,2-diol a pozorován po období 7 let. Pro analýzu stárnutí kapaliny v tomto systému byly sledovány základní provozní vlastnosti kapaliny jako jsou hustota, viskozita, teplota tuhnutí, pH a obsah kovů. Skrze tyto vlastnosti tak bylo sledováno stárnutí kapaliny nepřímo. Přímé sledování stárnutí bylo posléze provedeno analýzou degradačních produktů, jako jsou organické kyseliny a změny ve složení směsi pomocí izotachoforézy a hmotnostní spektrometrie. Pro srovnání byly taktéž analyzovány vybrané vzorky z několik dalších systémů plněných identickou kapalinou s prokazatelně pokročilou formou degradace. V druhé části práce jsou představeny základní fyzikálně-chemické vlastnosti směsí propan-1,3-diolu s vodou a jejich analytické hodnocení a matematické modelování pro universální použití jakožto nového základu pro nemrznoucí teplonosné kapaliny. Na základě dostupných informací je pak hodnocena použitelnost této směsi. Výhoda propan-1,3-diolu je spatřována především ve výrobě z obnovitelných zdrojů a v některých fyzikálních a chemických vlastnostech, které dle dosavadních poznatků předčívají doposud používané glykolové směsi.
Determination of TauroLock stability
Matejčíková, Eva ; Mravcová, Ludmila (referee) ; Čáslavský, Josef (advisor)
This diploma thesis deals with the study of the anticoagulant and antimicrobial agent TauroLockTM, which is manufactured by the german company TauroPharm GmbH. Based on the background research and taking into account the equipment of analytical laboratories of the Institute of Chemistry and Technology of Environmental Protection, optimal methods of analysis were proposed and a series of experiments were carried out which focused on the determination of the active substance and degradation products of taurolidine in TauroLockTM which was stored for a certain period of time in real conditions. The main task of this work was to determine the presence of taurolidine as the active substance and formaldehyde as the undesirable product of its decomposition.
Hormones in sewage sludge
Jagošová, Klára ; Vávrová, Milada (referee) ; Čáslavský, Josef (advisor)
Currently there is a spate of interest in the presence of pharmacologically active substances in the environment. These substances are excreted in active or metabolized form and with wastewater pass the wastewater treatment plant. Current treatment technologies do not always eliminate all pharmaceuticals effectively and therefore they enter the environment. One of these active groups is the group of steroid hormones. Steroid hormones belong to the group of endocrine disruptors and they are considered to be dangerous for the ecosystems. Due to the hydrophobic character of steroid hormones they undergo partial or total sorption from wastewater to sludge. Sewage sludge is the by product of wastewater treatment and contains heavy metals, organic contaminants and pathogenic bacteria. A part of produced sewage sludge is used as a fertilizer in the Czech Republic. This issue follows the regulation 347/2016 – conditions of agricultural use of sewage sludge. Waste policy of EU will alter the conditions of sludge disposal, so it is necessary to obtain data about the concentration levels, fate and behaviour of those pollutants. This thesis was focused on five natural female hormones and four synthetic, which are used as a part of contraceptive pills and substitutional hormonal therapy. Determination of hormones was performed in four steps including ultrasonic assisted extraction, clean up by solid phase extraction, derivatization and final analysis by gas chromatography with mass spectrometry on triple quadrupole in MS/MS mode.
Determination of Hydroxyacids including their Low- and High Molecular Derivatives
Lysáková, Klára ; Mravcová, Ludmila (referee) ; Čáslavský, Josef (advisor)
This bachelor thesis deals with the determination of hydroxy acids and their low and high molecular polymers. The theoretical part deals with their properties, production and utilization. The polymers of these substances are used as biodegradable plastics and as absorbable sewing materials. The experimental part is focused on the determination of the total component and on the composition and amount of impurities of selected samples of ethyl lactate, lactides and polylactide. Analysis was performed by gas chromatography (GC) and tandem techniques using GC/MS and Head-Space-GC/MS analysis.
Detailed characterization of pyrolysis oil by separation techniques and mass spectrometry
Žvaková, Veronika ; Mravcová, Ludmila (referee) ; Čáslavský, Josef (advisor)
The aim of this work is detailed characterization of pyrolysis oil by advanced analytical separation methods and mass spectrometry. During the pyrolysis process decomposition of complex organic material take place in the presence of high temperatures and the absence of oxygen. Condensable part of vapours and aerosols forms viscous liquid called pyrolysis oil which is a complex mixture of large amount of compounds. In this work samples from microwave pyrolysis of woodchips and sewage sludge from wastewater treatment plant Brno-Modřice were analysed. Samples were provided by Bionic Laboratories company. Samples were separated by column chromatography on activated silica. For detailed characterization of each fraction gas chromatography with mass spectrometry detection and comprehensive two-dimensional gas chromatography with mass spectrometric detection with time of flight analyser were used. Substances that have been identified can be divided into several groups: alkanes, alkenes, aromatic hydrocarbons, polycyclic aromatic hydrocarbons, alcohols, aldehydes, esters, carboxylic acid and heterocycles.
Characterization of efficiency of isolation procedures for fragrances from plants
Stávková, Markéta ; Mravcová, Ludmila (referee) ; Čáslavský, Josef (advisor)
The diploma thesis will be focuses on the isolation of fragrances of natural origin by steam vapor distillation, ultrasonic extraction, microwave extraction and pressure solvent extraction. The extracts were characterized by GCxGC/TOF-MS. To study the surface structure of the leaf by SEM, a sample of the medulla medical was selected. Photos were taken before and after extraction.

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