National Repository of Grey Literature 150 records found  beginprevious21 - 30nextend  jump to record: Search took 0.01 seconds. 
Removal efficiency of selected drugs by various sorptive materials from water
Štofko, Jakub ; Mravcová, Ludmila (referee) ; Vávrová, Milada (advisor)
This thesis deals with sorption of selected drugs from model water by various sorption materials. Contamination of water resources by the pharmaceutical industry is a major problem today. Wastewater treatment plants, whose technological processes are unable to completely remove them, have a significant share in the penetration of these substances into the environment. At present, attention is paid to alternative materials that are capable of eliminating these substances. One of the potential sorption materials is biochar as one of the main pyrolysis products. This work focused on the assessment of the sorption properties of the different types of biochar and commercially used active charcoal. The sorption properties of the individual materials were compared with respect to the non-steroidal anti-inflammatory substance ibuprofen and the sulphonamide antibiotic sulfamethoxazole. The results of vial experiments were analysed on a liquid chromatograph with mass detection.
Determination of PLA microplastics in soil by using pyrolysis methods
Románeková, Ivana ; Mravcová, Ludmila (referee) ; Kučerík, Jiří (advisor)
Nowadays, plastic waste poses one of the greatest risks to the environment. Plastics affect the environment at all stages of their life cycle. Bioplastics have become widely used as a substitute for conventional plastics, without detailed examination of their behavior in real environmental conditions. As a result, it is assumed that they can accumulate in the environment and the question arose as to how to identify them. The main goal of this thesis is to develop a method based on sample pyrolysis that is suitable for the identification and determination of the amount of PLA microplastics in soil and other solid matrices. Three types of soils and sludge were used for analysis. These matrices were spiked to obtain concentration ranges 0,2% - 5,0%. The pyrolysis resulted in evolution of gases with the signals m/z 29, 43 and 44, witch originated from PLA and are suitable for qualitative and quantitative analysis. Analysis of PLA in sludge was more complicated due to similarity of gases evolved from pure matrices. We tested three approaches based on analysis of signal´s peak areas, intensities and temperatures of gas evolution. While the first approach failed, the last two approaches appeared to be promising for qualitative and quantitative analysis of PLA in the sludge. Several methods suitable for qualitative and quantitative analysis of even very small amounts of PLA in soils and sludge have also been designed/developed. These methods were based on analysis of the composition and dynamics of the released gases and the characterisctic degradation temperatures.
The study of metallocene anticancer therapeutics-cells interaction
Bilavčíková, Kristýna ; Mravcová, Ludmila (referee) ; Vašinová Galiová, Michaela (advisor)
There were almost 600 thousand patients in Czech Republic until 2017 and the number keeps rising. Chemotherapeutics used today have lots of undesirable side effects, so scientists around the world are trying hard to find more specific and less cytotoxic drugs. In this bachelor’s thesis, potential drugs based on metallocene with a central atom of Ru, Hf or Zr were studied, always in three different drugs for each element. The permeability and distribution of these drugs into lung cancer cell lines were investigated. These drugs were detected by analysis of solutions and laser ablation with an ICP mass spectrometer. Based on the experiment, the greatest potential was found for the ruthenium-based drug 133, which had the highest permeability and was able to get into the cells in the highest volume.
Determination of organic compounds in biochar produced by microwave torrefaction of biomass
Meindl, Jiří ; Vávrová, Milada (referee) ; Mravcová, Ludmila (advisor)
The thesis is focused on a determination of polycyclic aromatic hydrocarbons (PAHs) contained in dried pelletized sewage sludge and pelletized biochar. Biochars were made in mild conditions by microwave torrefaction of prepared sewage sludge. There were analyzed and quantified the 34 of standardized PAHs compounds in two series. The first serie, also called “Sada 1”, has been aimed at comparison of extraction methods for the chosen sample of sewage sludge and the sample of biochar. In serie “Sada 1”, there were compared efficiencies of chosen type of solvent or solvent mixture by comparison of yields for 34 standardized analytes in a sample of biochar and a sample of sewage sludge. There were compared also to total yields of PAHs and to number of quantified compounds in analyzed samples. The most reliable extraction method has been used for the next analyses of samples in the second serie called “Sada 2”. In Sada 2, there were compared different samples of the same type (e.g. biochar, sludge). The origin of sewage sludge (small or big sewage treatment plant expressed as PE) and used additives (cellulose, chaff, hay) as modificators for torrefaction process were variables for different type of sample. The results of analysis were identification of the most suitable sewage sludge and additive to be used as modificator for microwave torrefaction process. The main goal of correctly chosen sludge and additive was to minimize production of PAH’s during torrefaction and in samples of biochar.
Monitoring of water and sediment contamination
Grajciariková, Eva ; Mravcová, Ludmila (referee) ; Vávrová, Milada (advisor)
The diploma thesis is focused on the issue of the presence of POPs in the surface water and sediments. Monitored compounds were chosen from the group of polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDE). Samples were collected in selected localities in the Slovak and the Czech Republic. Selected analytes were extracted with hexane from the aqueous matrix. Analytes were isolated by the ultrasonic extraction using a solvent mixture of hexane-dichlormethane from the solid matrix and the resulting extract was cleaned up by the column chromatography filled with the florisil and the silica gel. Target compounds were analysed by GC/ECD finally. Obtained results show the level of contamination in selected localities in the Slovak and the Czech Republic.
Solubilization of water-insoluble vitamins into vesicular systems based on ionic amphiphilic pairs
Kolomá, Nikola ; Mravcová, Ludmila (referee) ; Mravec, Filip (advisor)
This thesis deals with the characterization and preparation of catanionic vesicular systems and their interaction with water-insoluble vitamins. Catanionic vesicles systems was prepared from two differently charged sufractants CTAB and SDS in formation ion pair amphiphile. Stability of vesicles was secured by adding cholesterol with positively charged surfactant DODAC. Were selected vitamin A and vitamin E for solubilization into these vesicles. The next part of this work was focused on determining the efficiency of incorporation these vitamins into the HTMA-DS vesicular system. The characterization of these systems was improved by measurement on a UV-VIS spectrometer, DLS and by HPLC with UV-VIS detector. During measurement by UV-VIS and HPLC the efficiency of solubilization of vitamin A and vitamin E into vesicles was determinated. In both cases higher efficiency was determinated for vesicles with incorporated vitamin A. Higher efficiency for both vitamins was determinated by HPLC. The reason is probably the higher sensitivity of the metod, work in labs with dark glass and preparing individuals samples into vials, which were inserted into the device for individual dosing by injector. The work serves primary evaluation results in view of the vesicular system for use in pharmaceutical application like carrier non-polar vitamins.
Question of new halogen containing compounds in environment
Roček, Richard ; Mravcová, Ludmila (referee) ; Vávrová, Milada (advisor)
The target of my bachelor´s thesis is fabrication of literary recherche on theme brominated flame retardants. Into this group belong primarily polybrominated diphenyl ethers and compound hexabromocyclododecane. These compounds belong to perzistent organic polutants, whose production grew to the late time. Nowadays there are occur in almost all part sof environment. For their determination is using liquid and gas chromatography methods connected with mass spectrometry detection.
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.
Analysis of saccharides and markers of wood combustion in atmospheric aerosols
Kubátková, Nela ; Mravcová, Ludmila (referee) ; Mikuška,, Pavel (advisor)
Diploma thesis deals with the analysis of saccharides and markers of biomass and wood combustion in atmospheric aerosol, PM2,5. Theoretic part is focused on general characterisation of atmospheric aerosols and on the properties, sources and analysis methods of selected analysed organic compounds. The experimental part is focused on the optimization of method for simultaneous analysis of saccharides and tracers from biomass and wood combustion. Optimization of method includes selection of solvent for the extraction of compounds and optimization of derivatization process and GC/MS analysis. The optimized method was then applied for the analysis of selected compounds in real aerosol samples in the size fraction PM2.5. The concentrations of analysed compounds were compared in term of sampling seasons.
Ecotoxicological evaluation of selected plastics
Demová, Kristína ; Mravcová, Ludmila (referee) ; Zlámalová Gargošová, Helena (advisor)
The presented bachelor thesis deals with the issue of plastics in the environment and their ecotoxicological evaluation. This topic is currently being brought to the fore due to the development of new, more easily degradable plastics. This is intended to be a solution to the current environmental problem. That is why the aim of this work was to verify the assumption of ecological safety of such plastics. The experimental part focuses on one selected biodegradable plastic - polyhydroxybutyrate, which was evaluated using acute and chronic toxicity tests. The tests were performed in an aquatic arrangement to predict the effect on the aquatic ecosystem. Two organisms were chosen from its representatives, the crustacean Daphnia magna and the plant Lemna minor. The chronic test on the organism Daphnia magna shows the greatest results, which indicates the negative effects of the selected plastic on the tested organism.

National Repository of Grey Literature : 150 records found   beginprevious21 - 30nextend  jump to record:
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