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Preparation and Characterization of Iron Complexes with Amino Acids
Bednárová, Paula ; Hurčíková, Andrea (referee) ; Kalina, Michal (advisor)
This bachelor thesis focuses on the preparation and characterization of iron complexes with amino acids. The work in the theoretical part is focused on specification of iron as an essential element in living organisms, on his abilities to build complexes and on its wide range of biological attributes of these complexes, which can be natural or leading to various disorders of their metabolism. The studied literature is oriented on preparation of Fe(III) complexes with amino acids. In the experimental part of work we deal with titrational setting of zeta potential and critical aggregation concentration which were set only for amino acids L-lysine and an Aspartic acid. We also deal with coagulation reactions that had low yield in most of the selected amino acids except cystein, which doubled its amount after the modification of the conditions. We have stated that the resulting yield depends mainly on the type of used amino acid as well as on the used solvent and its amount used in synthesis.
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The influence of particle size and methods of preparation of calcium aluminate phases on their hydration
Ohaňka, Zdeněk ; Másilko, Jiří (referee) ; Koplík, Jan (advisor)
This work focuses on the hydration of four calcium aluminate phases – C3A, C12A7, CA and CA2. Above all, the influence of particle size and method of preparation on hydration behaviour were studied. Influence of these factors on hydration products were also investigated. Calcium aluminates were prepared by solid state synthesis and amorphous citrate method. Both methods were described in detail. The particle size was determined by laser diffraction. Isothermic calorimetry was used to investigate the process of hydration. Hydration products were identified by X-ray diffraction analysis and simultaneous thermogravimetric and differential thermal analysis.
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The study of sedimentation of MR fluids for space applications
Vančurová, Martina ; Strecker, Zbyněk (referee) ; Roupec, Jakub (advisor)
This bachelor thesis deals with experimental determination of the effect of iron particle size on the sedimentation rate of magnetorheological (MR) fluids. MR fluids from three producers are examined here: Liquids Research Limited (Great Britain), HaoHua (China) a LORD Corporation (USA). Particles describing the effect of MR fluids’ different attributes on their sedimentation are summarized in an overview of current knowledge. The development of the Matlab script, that detects and measures the size of particles in the input electron microscope images, is presented. The particles are also measured manually in some images, which is partly used as a reference measurement for the developed script. The particle size measurement results are then compared with the sedimentation behavior of examined MR fluids.
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Vliv struktury krmných směsí na parametry metabolismu pomalu rostoucích kuřat
Čumplík, Lukáš
This diploma thesis deals with the influence of the structure of feed mixtures on the metabolism parameters of slow-growing broilers. The issue of this topic was documented in the literature review. In the experimental part, an experiment was described regarding the determination of the influence of the structure of feed mixtures on nitrogen retention, ileal digestibility, parameters of organs of the digestive tract, histomorphometric parameters and the structure of feces. For research purposes, 120 slow-growing Hubbard JA 57 broilers were fattened for 49 days. During the fattening period, all broilers were fed feed mixtures identical in terms of nutrients, they differed only in the structure of the feed. 3 different textures were created - fine, medium and coarse. The feed mixtures were sieved through a system of sieves to determine the proportion of particle sizes. The influence of the structure of the feed mixtures on nitrogen retention was statistically significant difference (P<0.05) in the BR3 feed mixture, when it was shown that coarse particles have a positive effect on nitrogen retention. The results were not statistically significant for the BR2 feed mixture (P>0.05). When investigating the influence of the structure of the feed mixtures on the parameters of the organs of the digestive tract, a statistically significant difference (P<0.05) was found in the height of the muscle of the gizzard. For the other investigated parameters, the results were not statistically significant (P>0.05). Regarding the histomorphometric measurement, a statistically significant difference (P<0.05) was observed between the coarse feed mixture and the ratio of the length of the villi and the depth of the crypts in the duodenum and the depth of the crypts in the ileum. At the same time, it was evaluated as a statistically significant difference (P<0.05) between the structure of the feed and the structure of the droppings.
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Rôzna štruktúra častíc kŕmnych zmesí a jej vzťah ku kvalite a pevnosti granúl
Balog, Ronald
The diploma thesis is dealing with issues of different feed structures and its relation to quality and durability of pellets. Academic work. This thesis shows process of making pelleted feed mixtures, starting with right choice of feed and structure of particles, continuing with description of pelletization process. End of literature part is about evaluation right physical characteristics, nutritional aspects and effect of feeding pellets to animals. In experimental part, the work is devoted to the analysis and comparison of the structure of feed mixtures. The results of dry and wet sieve analysis, the results of measuring the hardness of pellets and the results of measuring the length of pellets. A statistically significant difference (P<0,05) was confirmed in structure of feed mixtures after pelletization, in influence of structure on physical quality of pellets and influence of pellet binders
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Solubility analysis of lignocellulosic substances with antioxidative efficiency
Hrušková, Lucie ; Kalina, Michal (referee) ; Kovalčík, Adriána (advisor)
One of the main obstacles to efficiently valorise lignin is its heterogeneous solubility, which varies depending on the biological origin and the method of isolation. The theoretical part of the bachelor thesis is devoted to a basic description of lignin from its structure to its specific properties, which has led to a wide range of studies on lignin. The experimental part of the thesis deals with the determination of the solubility of commercially available lignin in selected organic solvents Solubility was determined in a total of 15 pure or mixed solvents. The highest solubility of lignin was achieved in water, in which a solubility of 99.16 % was measured. For the eight best solvents, the size and stability of the dissolved particles were further analyzed. It was found that nanoparticles can be prepared using water and DMSO. Further, the antioxidant activity (expressed by TEAC parameter) and its structure (by FTIR) were determined for the dissolved lignin and its change was recorded. Based on the solubility results, two and three step fractionations were performed. Size, stability, and antioxidant activity were determined for the final fractions. The results obtained showed that during each fractionation step, characteristic functional groups were removed, thus decreasing the antioxidant activity of the resulting fractions.
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Evaluation and optimisation of a granulation process on a laboratory scale fluid bed granulator.
Stoniš, Jan ; Mužíková, Jitka (advisor) ; Řehula, Milan (referee)
The fluid bed granulation is a well-established method how to improve such properties of powders as flowability and increase content uniformity of the tablets. In this thesis, there was evaluated a granulation process on a lab scale fluid Glatt bed granulator and optimized for highest possible yield. Product yield in the size range of 80-90 % of granules and process reproducibility were stated as most effective. The product was analysed for its particle size distribution, the API distribution within the different particle size fractions and the flowability of the final granules. For process optimization, the most critical parameters such as spraying rate, particle size of raw materials and fluid bed pressure were identified and evaluated. As the highest-yielding dosage for the powder binder was found the spraying rate of 9 g/min. Changes in bed fluid pressure and nozzle pressure showed no significant improvement. Different grades of caffeine were compared for their impact on the granulation properties. Sieved caffeine enhanced yield of the product and reproducibility compared to bulk or disagglomerated caffeine.
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Influence of particle size of cosmetic pigments on final properties product
Obručová, Kateřina ; Hurčíková, Andrea (referee) ; Zemanová, Jana (advisor)
This diploma thesis is focused on the study of the influence of the of size cosmetics pigments on the properties of the final product. This effect was studied on samples of make-up given by industry partner. Make-up samples were measured by the rheology method and the yield stress of all samples was determined. Scanning electron microscopy was used to determine the size and shape of the pigment particles. Particle size was also measured by dynamic light scattering, but the results were influenced by forming aggregates. To easier determination of the types of pigments in the sample was determined elemental composition of the pigments (Ti, Fe, O, Al) by EDS detector. Due to the unknown composition of make-up, the information was supplemented by X-ray powder diffraction (XRD) analysis, and it was possible to determine the compounds TiO2 (anatase and rutile), FeOOH and Fe2O3. The results obtained by these methods showed what pigments can be found in make-up samples, what their sizes and shapes are. It has been shown that the smaller the pigments are, the higher the viscosity and yield stress of the final product. The higher these quantities, the harder it is to handle the product.
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Low-cost sensors for measurement of particulate matter
Dvořáková, Michaela ; Pokorný, Jan (referee) ; Lízal, František (advisor)
This work focuses on the research and comparison of several types of low-cost sensors for measurement of particulate matter. It clarifies the principles of aerosol particles measurement and focuses on the reasons of using low-cost sensors. It provides basic information about the impact of aerosols on human health. The experimental part of this work compares quality of the obtained results considering the price of the respective devices.
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