National Repository of Grey Literature 60 records found  1 - 10nextend  jump to record: Search took 0.00 seconds. 
Study on the Mobility of Selected Representatives of Pharmaceuticals in Natural Systems
Bednárová, Paula ; Pořízka, Jaromír (referee) ; Kalina, Michal (advisor)
This diploma thesis focuses on interactions of chosen pharmaceuticals with soil and study their mobility. First part is devoted to the characteristics of the most common pharmaceuticals that appear in the environment, specifically antibacterial chemoterapeutics and analgetics. Subsequently, the occurrence of the pharmaceuticals in environment, their sources and effects are described. Further, the work focuses on soil components and soil organic matter. In conclusion of the theoretical part is the description of used analytical method for processing of the results and also the current state of the problematics. In the practical part of the thesis the experiments were made and analyzed and further served for better understanding of adsorption and interactions of chosen pharmaceuticals with soil and humin acids as the main reactive part of the soil.
Optimization of preparation and characterization of hybrid hydrogels with respect to viscoelastic and flow properties
Zhurauliova, Darya ; Kalina, Michal (referee) ; Smilek, Jiří (advisor)
This bachelor thesis focuses on the study of hybrid hydrogels that combine the properties of the hydrogel system together with oleogels, which is a gel on the base of oil. The aim of the thesis is to carry out a study of the current state of the solved issue on the topic of preparation of hybrid hydrogels, on this basis to design and optimize the appropriate procedure of preparation and in the form of viscoelastic measurements to perform the basic reological characterization of the prepared systems. A system based on sodium alginate dissolved in deionized water and meshed with calcium chloride solution was chosen as a suitable hydrogel system, and a system based on beeswax dissolved in sunflower oil was chosen as oleogel. Sodium alginate has been chosen because it is used as a thickener, emulsifier, stabilizer or gelling agent in the creams and preparation of pharmaceutical forms. By mixing hydrogels and oleogels of different proportions, a hydrogel/oleogel system, also called bigel, was created, the properties of which were tested in terms of flow and viscoelastic properties. In the practical part, amplitude, frequency and flow tests of both the hydrogel itself and the hybrid hydrogel with a ratio of 50:50 (hydrogel vs. oleogel) were measured. These tests provided information on gel preparations, i.e. what is their character, what are the mechanical properties and how it depends on the amplitude of deformation. By comparing the measurement results, it was possible to determine how oleogel acts on the properties and structure of the hydrogel.
Adhesion Properties of Semi-IPN Hydrogels
Candráková, Simona ; Sedláček, Petr (referee) ; Kalina, Michal (advisor)
This Diploma thesis deals with optimization of the hydrogel preparation with various additions of substances affecting adhesion, studying the adhesion of prepared hydrogel systems and modifying their adhesion properties. Prepared hydrogels were agarose, alginate and gellan polymer systems with additions of acrylic acid, acrylamide, calcium chloride and Tween 20. The experimental part of the diploma thesis focuses first on optimizing the preparation of individual hydrogels, from which, according to certain criteria, suitable representatives were selected to study adhesion and its controlled modification. Agarose and gellan hydrogels were selected as suitable representatives, which were then used in rheological measurements. Based on these measurements, the effect of the adhesive force and the adhesive work of individual materials was evaluated. It was found that the best adhesion properties of the materials used are unadjusted hydrogels, in the case of hydrogels with the addition of another substance, a negative effect on adhesion was observed, when the adhesion force was reduced and also the adhesion work was reduced.
Isolation and fractionation methods for determination of humic substances content in South Moravian lignite
Černý, Pavol ; Kalina, Michal (referee) ; Enev, Vojtěch (advisor)
This bachelor thesis focuses on isolation and fractionation of humic substances (HS) from the natural matrix of lignite, which comes from southern Moravia from the mine Mír Mikulčice. In the theoretical part, it informs the reader about the issue, starting with information about lignite and HS. In this work, the standard procedure of isolation and fractionation of HS was used as according to the International Humic Substances Society (IHSS). The content of HS in the natural matrix of lignite was determined, and then isolated HS were subjected to physicochemical characterization – elemental analysis (EA), thermogravimetric analysis (TGA), UV/Vis spectrometry, infrared spectrometry with Fourier transformation (FTIR) and the acidity of humic acids (HA) was determined by potentiometric titration. EA was used to detemine the content of biogenic elements, moisture and ash content were determined by TGA. By using FTIR, various functional groups and building blocks that are present in supramolecules of HS were indentified and absorption coefficients EET/EBT, E2/E4, E2/E3 a E4/E6 were determined by UV/Vis spectrometry. Results represent good characterization of HS isolated from lignite and are in agreement with scientific literature.
Distribution of the Organic Matter in a Sample of Biochar
Novotný, Maximilián ; Enev, Vojtěch (referee) ; Kalina, Michal (advisor)
This bachelor’s thesis is focused on characterization of the content and distribution of organic matter in a sample of biochar. For these purposes, the organic matter from a biochar sample was isolated using two procedures, specifically sequential chemical fractionation, and alkali extraction. Prepared samples were characterized by elemental analysis and thermogravimetry. Analysis results showed that sequential chemical fractionation brings higher yields than alkali extraction, moreover, it provides more detailed image of organic matter in biochar thanks to obtained separated fractions according to their linkage to the original biochar matrix. Secondly, studied biochar has a great potential as soil supplement, it contains almost 70 % of organic carbon, whilst isolated amount, which is available represent only small amount, the rest is strongly bound. On the other hand, the study showed that this specific biochar has rigid structure, which brings benefits in the context of using biochar in agriculture in long-term consideration.
Study on the Effect of Biochar Application on Organic Matter in Soil
Kurková, Marie ; Sovová, Šárka (referee) ; Kalina, Michal (advisor)
This bachelor thesis studies the effect of the application of biochar on the composition of organic matter of two different soil samples. Specifically, the total content of organic matter in the soil and the ratio of humic and fulvic acids in these soils before and after the application of biochar were monitored. The composition of the soil mass was also observed thermogravimetrically and by using the certified method of humic and fulvic acids isolation from samples of studied soils. Furthermore, the effect of biochar on the growth of a model plant (maize – Zea mays) was observed. From this point of view, differences in plant growth were possible to observe from the beginning of the experiment, both in comparison with samples with and without biochar and in comparison with samples containing different doses of biochar. The type of soil used for cultivation experiments also influenced on plant growth.
Behaviour of diclofenac in soil systems
Šmerdová, Kateřina ; Kalina, Michal (referee) ; Klučáková, Martina (advisor)
In these days, a large amount of drugs are not completely removed in wastewater treatment plants, than it enters watercourses and then it leaks into soils. These substances are not natural in the environment, so they can have a negative effects here. This is very important to study the behavior of foreign substances in the environment. In this thesis the sorption and desorption behavior of the commonly used drug diclofenac in the soil system was monitored. The rate of sorption and desorption was determined from the change in diclofenac concentration analyzed by UV-VIS spectrometry. Changes in pH and conductivity were also monitored. Diclofenac showed good sorption properties in all the concentrations. There was no desorption or just a minimal desorption, that indicating a strong bond between diclofenac and soil and less leachability into the soil fusion. The results of this thesis showed, that even if diclofenac leaks into the environment, it is mostly adsorbed into the soil. This is largely positive, because diclofenac is practically harmless in the soil and due to the strong bond it also persist there.
Optimization of optical and transport properties of PVA based hydrogels
Zahrádka, Jan ; Kalina, Michal (referee) ; Sedláček, Petr (advisor)
The main goal of this bachelor thesis is to design and optimize a suitable method for preparation of transparent physically crosslinked hydrogels with manipulable transport properties. Polyvinyl alcohol (PVA) crosslinked by cyclic freezing and thawing was chosen as the model gel-forming material. From the originally proposed three mechanisms of influencing optical properties of thus prepared PVA gels, the influence of freezing rate was selected on the basis of pilot screening experiments for a deeper follow-up analysis. The mechanical properties of prepared hydrogels were analyzed by rheology using strain sweep test. The internal structure was visualized by scanning electron microscopy (SEM). The optimized technique for preparation of transparent PVA gels was subsequently used for preparation of gels with an interpenetrated polyelectrolyte component (poly (styrene sulfonate)). It was then experimentally verified by diffusion pair method with methylene blue as diffusion probe that the hybrid hydrogel network has modified transport properties.
Preparation and characterization of catanionic complexes
Mušková, Alexandra ; Kalina, Michal (referee) ; Mravec, Filip (advisor)
The diploma thesis deals with the preparation and characterization of catanionic complexes and their possible application to pharmaceutics and medicine. The catanionic complexes were prepared by mixing two oppositely charged surfactants with the concentration of 20 mmol·dm­3 in various volume ratios. Two systems were analyzed – CTAB + SDS and Septonex + SDS. Both systems were prepared in an aqueous and physiological environment. The turbidimetric analyses provided results of the intensity of turbidity of the prepared mixtures. The size and stability of the prepared particles were determined by DLS and ELS measurements. CTAB-rich samples showed significant viscosity changes and they were therefore characterized by rheological measurements. The results of this work show that the asymmetry of alkyl chains, surfactant selection, temperature, and ionic strength have a significant influence on the properties and self-assembly of surfactants in catanionic complexes.
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.

National Repository of Grey Literature : 60 records found   1 - 10nextend  jump to record:
See also: similar author names
5 Kalina, Martin
1 Kalina, Michael
1 Kalina, Miroslav
Interested in being notified about new results for this query?
Subscribe to the RSS feed.