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Study of low-temperature plasma products using mass spectrometry and their relation to thin film chemistry
Maršálek, Blahoslav ; Bránecký, Martin (referee) ; Čech, Vladimír (advisor)
The aim of this thesis was to analyse and interpret the spectra of tetravinylsilane as a function of plasma discharge power in order to find a relationship between plasma products, layer deposition and thin film chemistry. Another objective was to carry out a literature search in the field of plasma-enhanced chemical vapour deposition (PECVD) and mass spectrometry. Low temperature organosilicate-based plasma technology enables the synthesis of specific materials with controlled chemical and physical properties. The targeted synthesis of surfaces with controlled properties is determined by the atomic and molecular processes in the plasma, which are responsible for building the chemical structure and the resulting material in the form of a thin film. In this work, mass spectrometry has been used to detect and quantify the particles produced in the PECVD process, which is one of the methods that allow the characterization and identification of plasma products. Analysis of the mass spectra revealed that the molecules responsible for the growth of the layer contain carbon and silicon. The deposition rate determined by in situ spectroscopic ellipsometry correlates quantitatively with the flux of carbon and silicon particles that are chemisorbed on the film surface. The ratio of carbon and silicon deposited on the surface also correlates strongly with the C/Si flux ratio of the power driven plasmas. The contribution of silicon-containing particles as building blocks to the film growth decreases with increasing power and accounts for 20% (2 W), 5% (10 W) and only 1% (75 W) of the total chemisorbed fraction. This ratio between bound silicon containing particles and carbon particles affects the elemental composition and chemical structure of the deposited layers. The relationships between plasmachemical processes and particle adhesion on the surface are quite complex. The adhesion of silicon particles first increases sharply to a maximum at 25 W and then gradually decreases, which is characteristic of the so-called precursor-deficient PECVD. Similarly, the concentration of vinyl groups incorporated into the deposited layer and the fraction of sp2 hybridization of carbon correlate with the particle fluxes of the corresponding plasma. This work has demonstrated that mass spectroscopy is a suitable method for the study of plasmachemical deposition from the gas phase (PECVD). PECVD technology is promising for the deposition of silicon-containing layers, which is technologically applicable in many directions of materials research.
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Preparation and testing of large titanium dioxide layers
Maršálek, Blahoslav ; Kočí,, Kamila (referee) ; Veselý, Michal (advisor)
The aim of this bachelor theses was testing of mechanical and photocatalytical properties on printing suspension with different composition of the titanium dioxide with organosilicate binder printed on the PET foil. The cross-cut test was used to evaluate mechanical properties of the printed film surface. The photocatalytic activity was tested by decomposition of the acid orange 7 as a model pollutant using the UV-VIS spectrophotometry. Based on the results from experiments, the formal rate constants and the parameters of the mechanical stability of surfaces were obtained. The results shoved, that there is a clear correlation between the rate of organosilicate and titanium dioxide – the more is titanium dioxide, the higher is photocatalytic activity, but lower mechanical stability of the printed surface, what is probably caused by covering of titanium reaction centers by organosilicate. Possibilities of enhancing photocatalytic efficiency of the titanium dioxide and organosilicate composition are also discussed in this thesis.
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Study of low-temperature plasma products using mass spectrometry and their relation to thin film chemistry
Maršálek, Blahoslav ; Bránecký, Martin (referee) ; Čech, Vladimír (advisor)
The aim of this thesis was to analyse and interpret the spectra of tetravinylsilane as a function of plasma discharge power in order to find a relationship between plasma products, layer deposition and thin film chemistry. Another objective was to carry out a literature search in the field of plasma-enhanced chemical vapour deposition (PECVD) and mass spectrometry. Low temperature organosilicate-based plasma technology enables the synthesis of specific materials with controlled chemical and physical properties. The targeted synthesis of surfaces with controlled properties is determined by the atomic and molecular processes in the plasma, which are responsible for building the chemical structure and the resulting material in the form of a thin film. In this work, mass spectrometry has been used to detect and quantify the particles produced in the PECVD process, which is one of the methods that allow the characterization and identification of plasma products. Analysis of the mass spectra revealed that the molecules responsible for the growth of the layer contain carbon and silicon. The deposition rate determined by in situ spectroscopic ellipsometry correlates quantitatively with the flux of carbon and silicon particles that are chemisorbed on the film surface. The ratio of carbon and silicon deposited on the surface also correlates strongly with the C/Si flux ratio of the power driven plasmas. The contribution of silicon-containing particles as building blocks to the film growth decreases with increasing power and accounts for 20% (2 W), 5% (10 W) and only 1% (75 W) of the total chemisorbed fraction. This ratio between bound silicon containing particles and carbon particles affects the elemental composition and chemical structure of the deposited layers. The relationships between plasmachemical processes and particle adhesion on the surface are quite complex. The adhesion of silicon particles first increases sharply to a maximum at 25 W and then gradually decreases, which is characteristic of the so-called precursor-deficient PECVD. Similarly, the concentration of vinyl groups incorporated into the deposited layer and the fraction of sp2 hybridization of carbon correlate with the particle fluxes of the corresponding plasma. This work has demonstrated that mass spectroscopy is a suitable method for the study of plasmachemical deposition from the gas phase (PECVD). PECVD technology is promising for the deposition of silicon-containing layers, which is technologically applicable in many directions of materials research.
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Biotic threats to garden monuments: algae, cyanobacteria and invasive plant species
Pergl, Jan ; Perglová, Irena ; Albrechtová, J. ; Antl, Tomáš ; Abarenkov, K. ; Baldrian, Petr ; Cihlářová, L. ; Klečka, Jan ; Kohout, Petr ; Kvasničková, Jana ; Maršálek, Blahoslav ; Maršálková, Eliška ; Pejchal, Miloš ; Petružálková, M. ; Petřík, Petr ; Pyšek, Petr ; Sádlo, Jiří ; Štefl, Lukáš ; Tedersoo, L. ; Větrovský, T. ; Vlk, Lukáš ; Vojík, Martin ; Vosátka, Miroslav ; Zezulka, Štěpán
Chateau, city parks and gardens are perceived as harmonious parts of the landscape. Unfortunately, even these areas have to face various threats, and they can be a threat to the surrounding environment. The exhibition /catalogue presents a look at the organisms that threaten parks. These threats cover unwelcomed invaders covering invasive plants and small microorganisms in the soil, on facades, statues or in water. On the other hand, some species that are intentionally brought to the parks can be risky not only the gardens themselves but also their surroundings.
Fulltext:  PDF
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Preparation and testing of large titanium dioxide layers
Maršálek, Blahoslav ; Kočí,, Kamila (referee) ; Veselý, Michal (advisor)
The aim of this bachelor theses was testing of mechanical and photocatalytical properties on printing suspension with different composition of the titanium dioxide with organosilicate binder printed on the PET foil. The cross-cut test was used to evaluate mechanical properties of the printed film surface. The photocatalytic activity was tested by decomposition of the acid orange 7 as a model pollutant using the UV-VIS spectrophotometry. Based on the results from experiments, the formal rate constants and the parameters of the mechanical stability of surfaces were obtained. The results shoved, that there is a clear correlation between the rate of organosilicate and titanium dioxide – the more is titanium dioxide, the higher is photocatalytic activity, but lower mechanical stability of the printed surface, what is probably caused by covering of titanium reaction centers by organosilicate. Possibilities of enhancing photocatalytic efficiency of the titanium dioxide and organosilicate composition are also discussed in this thesis.
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Possibilities of removal of selected estrogens from water using
Maršálková, Eliška ; Maršálek, Blahoslav ; Endo, Valentina ; Godoy Alonso, Paula ; Jančula, Daniel
Advanced wastewater treatment technologies are focused on removal of micropolutants such as pharmaceuticals, estrogen disrupting compounds etc. To protect public health it is not possible to stop using pharmaceuticals, but it is necessary to find environmental friendly technologies which can remove or reducce these compounds. So called green technology and ferrates belongs to this treatment. It was found that estrogenes are reduced/removed from wastewater with different efficiency by common processes as it is shown in this paper. Processes using vegetative treatment and activated sludge treatment are compared. Results of estrogen removal by zerovalent iron and hexavalent iron are introduced.
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Estrogens in surface waters - sources, concentration, detection
Maršálek, Blahoslav ; Sadílek, Jan ; Maršálková, Eliška ; Endo, Valentina ; Godoy Alonso, Paula
Estrogenity in the surface water become to be a topic, where the orientation for not educated people should be difficult. At first, estrogens in the surface water cannot be substituted by the expressionenndocrine disrupting compounds (ED) what is more wide term (including estrogenity and e.g. androgenity). Compounds with estrogenic activity detected in surface waters are not only the contraceptive pills as is somewhere simplified, but it is a wide spectrum of compounds like PCB, heavy metals, pharmacs, pesticides etc. Moreover – estrogenic activity display also naturally synthetized compounds by plants (phytoestrogens), fungi (mycoestrogens), or by algae and cyanobacteria (phycoestrogens). These compounds are not analysed in the surface water yet. Exception is some rare analyses of phytoestrogens, we presume, that phycoestrogens can be produced in aquatic ecosystem in ecotoxicologically relevant concentrations. Estrogens can be detected in the water, sediments or in the aquatic biota by instrumental analyses (LC-MS/MS), or by ELISA, or e.g. by bioassays, which can detect also so called potential estrogens ( are able to bind to some of estrogen receptors, but effects in vivo were not proved yet). In the case of the comparison, or the interpretation of results from different sources we must consider the used detection method. Instrumental analyses are dedicated to selected compounds.. Bioassays represent the sum of compounds with (with proved, or potential) estrogenic activity. That is why we strongly recommend to pay an attention on the methods of sampling and analyse in the case of interpretation and comparison of estrogenity results from different resources. In the case of literature data usingincomparable methods or high detection limit we recommend the high carefulness. Where it is possible we recommend the combination of instrumental analyse with in vitro bioassays for detection of estrogenity in surface waters.
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Phosphorus Removal from Wastewater via Environmentally Friendly Technologies
Holba, Marek ; Škvoran, O. ; Maršálková, Eliška ; Maršálek, Blahoslav
Our research is recently focused on the phosphorus removal from wastewater treatment plant outlets. We chose two municipal wastewater treatment plants (with and without phosphorus removal) and tested zerovalent and hexavalent nanoiron for phosphorus removal. Ferrates showed promising results even for smaller dosages, whilst NZVI showed not satisfactorily results for full-scale application. Next work will include phosphorus fractionation and fate of different phosphorus fractions at the tertiary treatment. Increasing interest on xenobiotics, hormons, endocrine disruptors, heavy metals and PPCPs and their removal from the plant outlets will extend our testing in the future.
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