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Study of the crystallization process kinetics of perovskites and their precursors
Sršeň, Bohdan ; Gavranović, Stevan (referee) ; Zmeškal, Oldřich (advisor)
This thesis focuses on the properties of perovskite materials and examines the methods for preparing layers and potentially monocrystals of these materials. Emphasis is placed on analyzing the electrical and optical properties of perovskites. The experimental part of the thesis is dedicated to the preparation of perovskite material layers and subsequent measurement of their electrical properties during the crystallization process and after its completion. The prepared samples exhibit a macroscopic size due to the interdigitated electrode structure, ensuring a large active surface area. Special attention is given to the influence of nano-particles on the crystallization process and the resulting current-voltage (I-V) characteristics of the prepared samples. Understanding how the presence of nano-particles affects the crystallization and electrical properties of perovskite layers is crucial. These insights are necessary for further optimization of the preparation processes and enhancing the performance of perovskite materials in their final applications. The thesis provides an overview of the properties of perovskites and their preparation. The experimental results yield important insights into the relationship between nano-particles, crystallization, and electrical characteristics of perovskite layers.
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Strukturní studie serpinu Iripin-5 z klíšťat \kur{Ixodes ricinus}
SPĚVÁKOVÁ, Nikola
The aim of this bachelor thesis was a crystallization of serpin Iripin-5 from ticks Ixodes ricinus. Iripin-5 is the most produced serpin in the salivary glands of ticks. The focus of this thesis was to prepare protein Iripin-5 and perform crystallization experiments. Obtained crystals of Iripin-5 were in diffraction quality.
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Krystalizačně-strukturní studie bakteriofágového lysinu ECD7
REINDLOVÁ, Žaneta
This bachelor thesis is focused on the crystallization of newly acquired bacteriophage lysine ECD7. Bacteriophage lysine ECD7 could be one of a new alternative class of antibacterial agents possibly used against infectious diseases. The main goal of this work was to manage the basic crystallization methods, then apply them for crystallization of ECD7 lysine and produce a suitable crystals for X-ray diffraction analysis. Data from X-ray diffraction analysis will help clarify the structure and function of ECD7 lysine.
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Ice nucleating particles in the atmosphere
Gaálová, Gabriela ; Zíková, Naděžda (advisor) ; Sedlák, Pavel (referee)
The production of clouds and precipitation in the atmosphere is greatly influenced by microscopic ice nucleating particles, acting in the process of heterogeneous ice nucleation as ice nuclei. Examining the properties and variations of ice nucleating particles concent- rations over time might help to better predict future changes to the climate. The aim of this thesis is to summarise the information about processes of homogeneous, but primarily heterogeneous ice nucleation where specific physical and chemical features of these particles are applied. In this thesis, the main aerosol sources of ice nucleating particles and their abilities to directly or indirectly influence the atmosphere and climate are described. The observational methods of the concentration of ice nucleating particles in the air are also pre- sented, while the structure of the cloud expansion chamber PINE, which was used to obtain data values representing the amount of ice nucleating particles in the Czech Republic, is also described in more detail. From the data set total average values and time dependen- cies, including daily and weekly cycle were calculated; the part of the data processing is the statistical evaluation and comparison of the results with other studies. Keywords: ice nucleating particles, nucleation, aerosol,...
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Study of the influence of nanoparticles on water properties
Šram, Matěj ; Komendová, Renata (referee) ; Řezáčová, Veronika (advisor)
This work deals with the study of the influence of platinum nanoparticles with a size of 3 nm on the properties of water in a porous system. SiO2 with a defined pore size was used as a porous system, which can simulate the mineral component of the soil. The theoretical part deals with the properties of free and porous water and the impact of nanoparticles on the environment. In the experimental part, the properties of free water, water in the porous system and the influence of the presence of platinum nanoparticles on these systems are investigated using differential scanning calorimetry (DSC). The observed processes were melting, solidification and evaporation, and derived quantities such as crystallization and melting point.
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Salts of 2-aminoethanol and ferrocene-based acids
Zábranský, Martin ; Štěpnička, Petr (advisor) ; Němec, Ivan (referee)
Combination of the compact but sterically flexible ferrocene scaffold with intermolecular binding potential and conformational variability of (2-hydroxyethyl)ammonium structural motif was utilised in the construction of solid crystalline materials. Crystallisation in systems containing ferrocenecarboxylic, 2-ferrocenylacetic, 3-ferrocenylpropionic, 3-ferrocenyl- acrylic, 3-ferrocenylacrylic, 3-ferrocenylpropiolic, ferrocene-1,1'-dicarboxylic or ferrocene- sulfonic acid with 2-aminoethanol afforded crystals of the corresponding salts. The resulting crystalline products were characterised with the usual methods (proton nuclear magnetic resonance, infrared spectroscopy, elemental analysis) and their crystal structures were determined by means of single-crystal X-ray diffraction analysis. The crystal structures of the salts mentioned above usually contain rather complicated two dimensional networks of charge-assisted hydrogen bonds. With the aim of studying potentially more simple hydrogen-bonded structures, additional crystallisation experiments were conducted in systems of ferrocenecarboxylic acid and 2-(methylamino)ethanol or 2-(dimethylamino)ethanol. These experiments yielded simple salt of the former amine and adducts of salts of both bases with ferrocenecarboxylic acid in the ratio of 1:1. The...
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Quantitative description of textures in volcanic rocks: Case study of trachybasalt from Dubičná
Ditterová, Hana ; Dolejš, David (advisor) ; Rapprich, Vladislav (referee)
- iii - ENGLISH ABSTRACT Quantitative description of textures, in particular, the distribution of grain sizes, is becoming a powerful tool for interpreting kinetic processes that govern crystallization of igneous rocks. Variation in grain size are frequently represented by logarithm of population density vs. linear crystal size, where the majority of igneous rocks forms a linear trend. Its slope provides an estimate of characteristic grain size, or growth rate and crystallization time, whereas the intercept provides the nucleation density. The log-linear trend is predicted to result from kinetic nucleation and growth processes only, whereas its modifications such as kinks or curvature are due to mechanical separation or accumulation of crystals, magma mixing or Ostwald ripening (coarsening) in the presence of melt. In order to investigate the true, three-dimensional crystal size distribution, the raw two-dimensional data acquired from thin sections or rock slabs must be processed by various stereological methods. We illustrate application of quantitative textural measurements to distribution and origin of clinopyroxene crystals in a trachybasaltic lava flow from Dubičná near Úštěk. This effusion belongs to Cenozoic volcanic products in the Bohemian Massif, specifically to its main Eocene-Miocene stage in...
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