National Repository of Grey Literature 212 records found  beginprevious41 - 50nextend  jump to record: Search took 0.01 seconds. 
Substituted polyaromatic compounds in environmental components
Kubalík, David ; Mravcová, Ludmila (referee) ; Vávrová, Milada (advisor)
This work is focused on substituted polycyclic aromatic hydrocarbons (PAHs) in environmental compartments. The thesis examined the development of these compounds and their entry into the ecosystem. Due to their proven negative characteristics to be addressed also their toxicology. The next section discusses the appropriate methods, including sampling, sample preparation and final determination. The conclusion of this work forms draft standard operating procedure for their determination.
Preparation of microbial, plant and algal extracts to use in cosmetics for infants
Janderová, Šárka ; Dzurická, Lucia (referee) ; Márová, Ivana (advisor)
This bachelor thesis deals with the preparation of a cosmetic product for infants with the addition of active substances from cyanobacteria, microalgae, or plants. In the theoretical part, a review was made, which not only summarizes the basic information about these organisms, but also the antioxidants contained in these microorganisms. In the practical part, several types of extracts from cyanobacteria, algae and plants were prepared and characterized. The content of phenolic substances, chlorophylls and content of carotenoids were measured spectrophotometrically. Content of soluble proteins was determined by Hartree-Lowry method and the fatty acid profile in biomass was obtained by GC. Furthermore, the SPF factor was measured using the spectrophotometric method the Mansur equation. Antioxidant activity was determined by using the TEAC method. Finally, two of the best extracts were selected for the preparation of cosmetic emulsions. The sensory analysis of prepared emulsions was performed for the period of two weeks.
Analysis of organic substances present in biochar
Bača, Ondřej ; Řezáčová, Veronika (referee) ; Mravcová, Ludmila (advisor)
This master's thesis deals with the analysis of organic substances, which are present in biochar. Biochar contains a number of organic compounds, that can be toxic and also carcinogenic to living organisms. In order for biochar to be used to improve soil quality or to be used for other applications, its safety must be declared by European or international certifications. Relevant European and international standards have been created for the determination of organic substances, that could be present in biochar. The theoretical part of the thesis was focused on selected organic substances, the process of pyrolysis and thermochemolysis, biochar characterisation and the used analytical methods. The experimental part of the thesis consisted of extraction with toluene and after that the determination of concentration of the 38 polycyclic aromatic hydrocarbons was performed. Qualitative analysis was performed by two-dimensional gas chromatography. Biochar samples were also subjected to thermochemolysis method and then they were analysed on GC-MS again. In both analytical methods, a large number of substances from groups such as PAHs, carboxylic acids, amines, substituted naphthalenes etc. was found, as well as smaller number of eg. polychlorinated biphenyls.
Exploitation of Infrared Spectroscopy for Determination of Polymer Admixtures in Cement Composites
Novotný, David ; Hodná, Jana (referee) ; Petránek, Vít (advisor)
In the thesis deals with the possibilities of determining the amount of polymer additives FTIR. Are described in detail various polymeric ingredients which are used in concrete mixtures. Then thoroughly discuss the use of recyclable polymer additives polyvinylbutyral (PVB), its production, the primary use, recycling and subsequent use. Next, I will discuss methods for determining the amount of polymer in the substance. In the experimental part were blended with several samples with different percentage for each polymer. Where we conducted appropriate tests and assessments, and individual samples are briefly described, evaluated and compared.
Recycling of steel-works flue dusts from electric arc and inductive furnaces
Huczala, Vít ; Koplík, Jan (referee) ; Šoukal, František (advisor)
This bachelor thesis deals with an application of electric arc furnace dust from steel production as secondary raw material for production of zinc and industrially process able zinc products. In this thesis the dust was processed by methods based on various physical and chemical properties. The most experiments were performed during the treatment with leaching in sulphuric acid. For this leaching the optimal concentration of sulphuric acid and the optimal ratio acid:dust was determined. The final products were prepared by precipitation or by evaporation of filtrate obtained after leaching. There were also used hydrolysis of dust and oxidative precipitation of filtrate during the processing. These steps led to increase of the quality of the final products. The price balance was also performed for the prepared products.
Possibilities of identification of essential oils in environmental matrixes
Plačková, Lucie ; Zlámalová Gargošová, Helena (referee) ; Vávrová, Milada (advisor)
Contained substances type of essentials oils in samples of phytogenic are characterized in this thesis, namely in tree needles and in moss, theirs chemical fission, description effects on human health and theirs use in medicine. Thesis describes method of isolation and identification of essentials oils from plants. For isolation of essentials oils there are used methods solvent extraction and solid phase microextraction (SPME) and steam distillation, for identification there are thin layer chromatography (TLC) and gas chromatography (GC/MS).
Bifurcation Localization in Retina Images
Pres, Martin ; Drahanský, Martin (referee) ; Semerád, Lukáš (advisor)
From biometrical point of view, main features of retina are fovea, optic nerve and blood vessel tree. Blood vessel tree is unique for each person and this biological feature is used in biometric systems for person-recognition by retinal images. This document describes methods for optic disc and fovea localization, method for vessel tree segmentation, which is based on well-known \emph{Matched filters} method and also describes method for localization of blood vessel bifurcations. Main goal of this thesis is creation of program which can automatically preprocess input image, segment blood vessels and localize vessel bifircations. The program is implemented in Java with OpenCV library.
Biological effects of complex extracts from yeast and algae biomass
Bočán, David ; Byrtusová, Dana (referee) ; Skoumalová, Petra (advisor)
This bachelor thesis was focused on optimalization of extractions of active compounds from microalgae and carotenogenic yeasts. Other part of this work was focused on characterization of these extracts and their tests of cytotoxicity on human keratinocytes. In theoretical part a literary research which summarizes the basic properties and cultivation conditions of used microorganisms was conducted. Then there were listed an examples of antioxidant compounds found in these microorganisms as well as their properties. Finally the term cytotoxicity and methods of its measurement were clarified. The practical part of this thesis consists of series of extractions from mentioned microorganisms. These extracts were characterized by the content determination of phenolic and flavonoid compounds and also chlorophyll and carotenoid compounds. Determination of antioxidant capacity and SPF were done too. Lastly the cytotoxicity of chosen extracts was measured using the MTT test.
Tunneled Data Extraction into Separate Flows
Nahálka, Roman ; Hranický, Radek (referee) ; Holkovič, Martin (advisor)
The goal of this work is to design and implement an application for extraction of tunneled data into seperate flows. The app will be removing all layers of encapsulation, that the file contains.The use of the app lays in better analysis and diagnostics of network communication. Thanks to removing the tunnels from the network flow, it will only contain data we can use. In the theoretical part, the work focuses on network architecture TCP/IP, the tunneling protocols and ways of capturing communication on the network. The practical part describes the way of retrieving test data, it also contains a design of the target application, as well as implementation of this design and testing of the final application.
Speciation analysis of selenium in selenized yeast
Motlová, Tereza ; Vitoulová, Eva (referee) ; Diviš, Pavel (advisor)
The aim of the theses was determination of selenium species in yeast Saccharomyces cerevisiae cultivated in medium with added inorganic form of selenium (Sodium Selenite). Concentrations of Sodium Selenite in cultivation medium were 0,1; 1; 10 and 100 mg.l-1. Cultivation was undertaken in fermenting tub for period of 72 hours. Cultivated yeasts were extracted by use of enzymes and subsequently the species of selenium in particular parts of yeasts were determined. In order to determine selenium species, the method of high-performance liquid chromatography in combination with atomic fluorescent spectrometer and technique of hydride generation was used. Having analysed different fractions of the yeasts Saccharomyces cerevisiae it was ascertained that during cultivation the sorption of selenium occurred in form of Se4+ in cell membranes while in cytoplasm no inorganic forms of selenium were found. Furthermore, it was stated that yeasts Saccharomyces cerevisiae are able to metabolically change inorganic forms of selenium to organic forms (selenomethionine), while these forms are present in cytoplasm and they are likely to be bound to proteinic structures of cell membranes. An increase of concentration of Se4+ in cell membranes could be observed as a result of increasing concentration of Sodium Selenite in cultivation medium. In proteinic structures the concentration of organic selenium forms increased only to concentration 10 mg.l-1 of Sodium Selenite in cultivation medium.

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