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Study on reactivity of humic acids via method of diffusion cells
Hrubá, Pavla ; Weidlich,, Tomáš (referee) ; Sedláček, Petr (advisor)
The diploma thesis focuses on utilization of diffusion cells in reactivity mapping study on humic acids. In the experimental part, samples 6 humic acids of different origin or chemical modification were studied. All the samples were characterized by basic analytical and physico-chemical methods (elemental analysis, thermogravimetry, determination of acidity, spectrometry). Methylene blue was utilized as a model reactive probe and agarose gel as an inert support medium. An effect of interactions between humic acids and methylene blue on diffusivity of the dye in the hydrogel was determined and discussed.
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Spectrometric Methods for Research of Humic Substances
Enev, Vojtěch ; Maršálek, Roman (referee) ; Sýkorová, Ivana (referee) ; Klučáková, Martina (advisor)
The main aim of doctoral thesis is the study on physicochemical properties of humic substances (HS) by modern instrumental techniques. The subject of the study were HS isolated from South Moravian lignite, South Bohemian peat, forest soil Humic Podzol and finally extract from brown sea algae Ascophyllum nodosum. With respect on determination of structure and reactivity of these unique “biocolloids”, standard samples (Leonardite HA, Elliott Soil HS and Pahokee Peat HS) were also studied. These samples were obtained from International Humic Substances Society (IHSS). All mentioned substances were characterized by elemental analysis (EA), molecular absorption spectroscopy in ultraviolet and visible region (UV/Vis), infrared spectroscopy with Fourier transformation (FTIR), nuclear magnetic resonance spectroscopy of carbon isotope 13C (LS 13C NMR), steady-state and time resolved fluorescence spectroscopy. Obtained fluorescence, UV/Vis and 13C NMR spectra were used for calculation of fluorescence and absorption indexes, values of specific absorbance and structural parameters respectively, which were used for fundamental characterization of these “biocolloidal” compounds. Infrared spectroscopy with Fourier transformation was utilized for the identification of functional groups and structural units of HS. Evaluation of infrared spectra is quiet complicated by overlapping of absorption bands especially in fingerprint region. This problem was overcome by Fourier self-deconvolution (FSD). Steady-state fluorescence spectroscopy was used for deeper characterization of HS with respect to origin, structural units, amount of substituents with electron-donor and electron-acceptor effects, content of reactive functional groups, “molecular” heterogeneity, the degree of humification, etc. Parameters of complexation of samples Elliott Soil with heavy metal ions (Cu2+, Pb2+ and Hg2+) were obtained by using modified Stern-Volmer equation. These ions were chosen purposefully, because the interaction of HS with these ions is one of the fundamental criteria for the assessment of the reactivity of HS. Key part of the whole doctoral thesis is time-resolved fluorescence spectroscopy. It is able to determine the origin of emission of HS by method Time-Resolved Area Normalized Emission Spectra (TRANES). The viscosity of micro medium about excited fluorophores of HS was determined by Time-Resolved Emission Spectra (TRES).
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Investigation of Nuclear Power-Reactor Core Poisoning
Janošek, Radek ; ČR,, Milan Štefánik, Ústav jaderné fyziky AV (referee) ; Katovský, Karel (advisor)
The aim of this Bachelor´s Thesis is to characterize fundamental transient processes, which takes place in nuclear power-reactor. The main goal is the theoretical analysis of these processes, which include xenon poisoning, samarium poisoning, xenon after shutdown, xenon oscillation, and permanent poisoning. A significant part of the thesis deal with the simulation of xenon poisoning and samarium poisoning. Model was created using Maple software. One of the other points is to state the basic concepts of nuclear physics and also to describe nuclear power-reactor primary operating processes.
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Evaluation of lime properties
Palušáková, Stanislava ; Beranová, Denisa (referee) ; Opravil, Tomáš (advisor)
This thesis deals with the evaluation of the properties of limes, which are used in the field of heritage preservation of monuments, but also for common construction applications. The aim of this thesis is to draw up the appropriate set of analyzes that suffice the necessary minimum for the evaluated characteristics of air limes. Based on the results obtained in this set it will be characterized analysed lime and recommended it for a specific application. For simple solution of this work we have to deal with using traditional commercially available lime CL 90, CL80 and CL70. Selection of appropriate characteristic analysis was based on CSN EN 459.
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Study on Reactivity of Cationic Biopolymer by Simple Diffusion Techniques
Tesařová, Barbora ; Kalina, Michal (referee) ; Smilek, Jiří (advisor)
This bachelor thesis is focused on study of chitosan reactivity by simple diffusion processes realized in hydrogel media based on agarose. Mechanical properties studied by oscilatory measurements and the pore size were determined at agarose gels with the addition of chitosan as the main parameters influenced the transport properties. The main goal of this work is the investigation the reactivity of chitosan. Agarose is used only as a supporting matrix for the formation of a hydrogel. The state of the art is aimed primarily on the study of chitosan reactivity based on already published scientific papers.
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Study of the influences that affect the reactivity of a limestone
Sklenářová, Dorothea ; Bureš,, Jaroslav (referee) ; Dvořák, Karel (advisor)
This thesis is a part of grant assignment and focuses on the effect and properties of input material, limestone, on reactivity and speed of decarbonation. The aim of this thesis is to find the effect of chemical composition, petrography, genesis and diagenesis, porosity and microstructure of limestones on reactivity and speed and profile of decarbonation. The experimental part of thesis describes analysis of chosen limestone samples regarding porosity, reactivity by Bischof-Uhde method and process of decarbonation of calcite in term of crystallinity of product.
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New Methods of Study of Reactivity and Transport Properties of Biocolloids
Smilek, Jiří ; Weidlich,, Tomáš (referee) ; Pabst, Willi (referee) ; Klučáková, Martina (advisor)
The main aim of doctoral thesis was the study on reactivity, transport and barrier properties of biocolloidal and synthetic polymeric substances by simple diffusion techniques. It was studied mainly the influence of basic physic-chemical parameters (temperature, concentration, pH and modification of material) on the reactivity and barrier ability of chosen compounds. Further substances were chosen as a model compounds: biocolloids (humic acids, alginate, chitosan, hyaluronate) and synthetic polymer (polystyrenesulfonate). Reactivity, barrier and transport properties of chosen substances were studied by interactions with oppositely charged basic organic dyes (methylene blue, rhodamine 6G, amido black 10B respectively) in hydrogels medium based on linear polysaccharide (agarose). The attention was also paid to basic physic-chemical characterisation (infrared spectroscopy, rheology, elemental analysis, thermogravimetry and scanning electron microscopy) of chosen materials and also hydrogels. Key part of the whole doctoral thesis was the optimization of selected diffusion techniques (diffusion cell technique and non-stationary diffusion in cuvettes) designated for the study on reactivity and barrier properties of wide range compounds (optimized method should be used as an universal method for simple and fast determination of reactivity of different compounds at given or changing conditions). The rate of reactivity, transport and barrier properties was determined based on fundamental diffusion parameters such as diffusion coefficients, break-through time so called lag time, interfacial concentration of chosen organic dye, apparent equilibrium constant, tortuosity factor, partition coefficient.
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Study on the Reactivity of Extracellular Polysaccharides Produced by Bacteria
Vacková, Barbora ; Smilek, Jiří (referee) ; Kalina, Michal (advisor)
This bachelor thesis deals with the reactivity of bacterial extracellular polysaccharides. The experimental part deals with extracellular polysaccharide FucoPol. Due to the presence of acyl groups, the polymer has an anionic character and can promote interactions with other positively charged substances. In this bachelor thesis interactions of FucoPol with metals were studied. For measuring, an isothermal titration calorimeter was used, and sorption experiments were performed. The main objective of the work was optimization of conditions for measuring interactions between metals and FucoPol. Connection of metal cations to FucoPol matrix were confirmed by titration calorimetry and sorption experiments. The interaction rate was different depending on the metal which was used. Co2+, Pb2+ a Zn2+ ions showed very weak binding, otherwise Cu2+ a Fe3+ ions had high affinity for the studied biopolymer. FucoPol, as a biodegradable biopolymer, can be in the future one of important industrially produced polysaccharides. It could be used for packaging, biofuel production and production of anti-inflammatory and immune-boosting drugs.
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Influence of pH and ionic strength on barrier abilities of humic substances
Přítulová, Marie ; Kratochvílová, Romana (referee) ; Klučáková, Martina (advisor)
The main aim of this bachelor thesis is the study of humic acids and their barrier properties. The reactivity of humic acids was studied by simple laboratory diffusion techniques in plastic diffusion cells. This thesis is mainly focused on the through-diffusion processes in hydrogel media. Hydrogel media were based on the thermoreversible polysaccharide (agarose) with or without addition of humic acids. The rate of reactivity of humic acids was compared by the interactions with organic cationic dye – methylene blue. The influence of ionic strength and pH was tested as well.
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Ferrocene stibane ligands
Antala, Jakub ; Štěpnička, Petr (advisor) ; Gyepes, Róbert (referee)
5 Title: Ferrocene stibane ligands Author: Jakub Antala Department: Department of Inorganic Chemistry Supervisor: prof. RNDr. Petr Štěpnička, Ph.D., DSc. Abstract: This diploma thesis reports a study into the coordination properties of ferrocene phosphino-stibine Cy2PfcSbPh2 (LCy, Cy = cyclohexyl, fc = ferrocene-1,1'-diyl). Complexes with various transition metals were prepared (RuII , RhIII , PtII , PdII , AuI ), where the ligand binds in monodentate, bridging or chelating mode. Ruthenium(II) and rhodium(III) complexes were prepared from precursors with π-coordinated arene ligands, whereas [MCl2(η2 :η2 cod)] (M = Pd, Pt; cod = 1,5-cyclooctadiene) precursors were used to prepare palladium(II) and platinum(II) complexes and synthesis of gold(I) complexes started from [AuCl(tht)] (tht = tetrahydro- thiophene). In addition, the thesis describes the reactivity of ferrocene phosphino-stibine Ph2PfcSbPh2 (LPh). Specifically, it focuses on the preparation of chalcogenides Ph2P(E)fcSbPh2 (E = O, S, Se) and the corresponding stiborane derivatives Ph2P(E)fcSbPh2(O2C6Cl4) (E = void, O, S, Se), in which the stiborane center bears tetrachloropyrocatechol substituent, which makes it Lewis acidic and potentially prone to behave as an acceptor of electron pair from the Ph2P(E) moiety. The presence of this interaction was...
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