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Utilization of vibrational spectroscopy for in-situ qualitative and quantitative analysis of polyhydroxyalkanoates in microbial biomass
Kevélyová, Barbora ; Enev, Vojtěch (referee) ; Sedláček, Petr (advisor)
The aim of this bachelor thesis was to evaluate the applicability of selected methods of vibrational spectroscopy for qualitative and quantitative analysis of biomass, which contains polyhydroxyalkanoates. Fourier-transform infrared spectroscopy, that uses attenuated total reflection technique (ATR-FTIR), was chosen for this experiment. Poly(3-hydroxybutyrate-co-4-hydroxybutyrate) has been studied in Cupriavidus malaysiensis, Thermomonas hydrothermalis and Aneurinibacillus thermoaerophilus sp. H1. Data were obtained by evaluating the infrared spectra, which were then compared with the results of performed gas chromatography. Visual changes in the spectra were also observed along with crystallinity. No correlation was detected between the data obtained by gas chromatography and by the method ATR-FTIR in quantitative analysis. Thus, this method is not suitable for determining the content of poly(3-hydroxybutyrate-co-4-hydroxybutyrate) in biomass in the set experiment and the bacteria used. On the other hand, the method was successfully used for in-situ qualitative analysis of copolymer in the samples of Aneurinibacillus thermoaerophilus sp. H1. The degree of data correlation was relatively high in the given experiment. With these findings, ATR-FTIR is a suitable analytical method for determining the monomer composition of poly(3-hydroxybutyrate-co-4-hydroxybutyrate) in this strain. Comparison with the PHA producer Cupriavidus malaysiensis showed that this method is not universal for all types of microorganisms observed in this thesis.
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Utilization of vibrational spectroscopy in study on interactions between humic substances and organic ions.
Stehlíková, Kristína ; Enev, Vojtěch (referee) ; Sedláček, Petr (advisor)
The main objective of this bachelor thesis was to validate the potential of the utilization of vibrational spectroscopy in the study on interactions between humic substances and organic ions. Unmodified (HA) and methylated humic acids (mHA) were chosen as model humic substances and organic ions were represented by methylene blue, rhodamine 6G and Septonex. Firstly, a suitable infrared spectroscopy technique was chosen. The results of optimization measurements showed that spectra with the best resolution can be obtained using the DRIFTS technique. The next part of the thesis discusses the effect of methylation in the structure of humic acids. Significant differences were recorded in mHA compared to the unmodified humic acids. Finally, the spectra of humic acid – organic ion complexes were compared to the spectra of prepared blank samples. It was noted that the spectra of complexes are not only a simple sum of the pure individual substances’ spectra, but also shifts and changes in the intensity of different absorption bands were recorded there. It suggests that non-covalent interactions played an important role in the complexes. Infrared spectroscopy was proved to be a useful method for investigating these interactions.
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Humic substances as active or auxiliary pharmaceutical component
Blahuš, Petr ; Kalina, Michal (referee) ; Sedláček, Petr (advisor)
This thesis examines the effect of the potassium lignohumate on the transfer speeds of analgesic drugs through the synthetic Strat-M® membrane. In order to examine the transfer of these substances, vertical diffusion cells were used and the final samples were analysed using UV-VIS spectrometer and HLPC. The intention of this thesis was to optimise the process of preparing diffusion cells, to compare the transfer speeds of pure active substances and active substances with the potassium lignohumate, and to compare the permeability of Strat-M® membranes, by using pig skin membranes which were used in the previous study that this thesis continues from. The primary discovery was that the lignohumate slowed down the transfer of active substances through the membrane.
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The influence of biochar on physico-chemical properties of soil
Polášková, Nikola ; Sedláček, Petr (referee) ; Smilek, Jiří (advisor)
This thesis is focused on assessment of the influence of biochar on the soil physico-chemical properties (particle density, dry density, porosity, water retention capacity and maximum water holding capacity, oxidizable carbon content, total nitrogen content, phosphorus, potassium and magnesium content). The selected and examined soil types were: cambisol, fluvisol, chernozem and regosol. There were two types of biochar used for analysis – NovoTerra and Sonnenerde. Soil samples were dried to constant weight and adjusted to grain-size fraction under 2 mm, respectively 0,25 mm. The oxidizable carbon content was measured by oxidation using a mixture of potassium dichromate and sulphuric acid (Walkley-Black method), the total nitrogen content was measured by kjeldahlization and P, K and Mg content was measured using Mehlich 3 extraction and ICP-OES spectrometer. The results show that biochar has a significant influence on soil characteristics depending on the type of biochar and soil we use for biochar application. This thesis can be used to clarify the complex issues in terms of soil in Czech Republic or it can be used by farmers considering using biochar as a soil additive with the intention to increase productivity and fertility of soil.
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Limitations of Incompressible Encodings
Sedláček, Petr ; Hubáček, Pavel (advisor) ; Mareš, Martin (referee)
This thesis studies the limitations of incompressible encodings with information- theoretic security. We demonstrate a flaw in the existing proof of the impossibility of constructing incompressible encodings information-theoretically. Our main contribu- tion is a full proof of impossibility of existence of non-trivial information-theoretically secure incompressible encoding schemes. In the first part of the thesis, we introduce the basics of incompressible encodings and provide the necessary definitions. Next, we present the flaws in the existing argument and provide explicit counterexamples to them. Throughout the rest of the thesis, we gradually construct a complete proof. We start by showing the impossibility under a few additional restrictions on the correctness and structure of the schemes that we subsequently remove one by one. Finally, we present an adversary able to break any non-trivial incompressible encoding scheme. 1
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Common boxing injuries
Sedláček, Petr ; Stich, Jaroslav (advisor) ; Zdobinský, Adam (referee)
Title: Common boxing injuries Objectives: Description of the causes of injuries and summarize the common frequent injury in training and matches of amateur and professional boxing. Methods: In this work was used the scientific method of the questionnaire and subsequent evaluation of analytical and synthetic data. Data analysis method was used in the theoretical part, which analyzed the literature and empirical part where the points were analyzed questionnaire, based on the graphical representation. Synthetic method was used to compare different points of the questionnaire and discussion work.In the study subjects are evaluated frequency of injuries in boxing, the causes of injuries and recovery time. Results: Through a questionnaire survey it was found that most frequently injury takes place a injury of the facial part of boxer's head. It was found 57% of all injuries in boxing in the facial part and it is a minor abrasions or bruises that do not affect the athlete's performance. Keywords: box, injury, joint, contest
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Complementary analysis of procaryotic cells by electron microscopy and Raman spectroscopy
Ikrényiová, Terézia ; Sedláček, Petr (referee) ; Hrubanová, Kamila (advisor)
This master thesis deals with conventional methods of bacterial cell analysis, polyhydroxyalkanoates, Raman spectroscopy and electron microscopy in the theoretical part. The production of polyhydroxybutyrate by selected thermophilic bacteria and their analysis by gas chromatography, cryogenic scanning electron microscopy and Raman spectroscopy is described in the experimental part. The chosen sample was analyzed by a transmission electron microscope. Comparing the results from previous mentioned methods it was found that the bacteria Schlegelella thermodepolymerans accumulated the highest amount of PHB. The lowest amount of PHB was obtained by bacteria Rubrobacter xylanophilus. The assumption that the PHB granules formed so-called needle-like plastic deformations during freeze-fracturing was affirmed by cryo-SEM photos analysis. Moreover, it was found that the bacterial cell characterization deduced from microscopic observation of samples corresponded to the description in the literature. TEM provided better resolution photos and in consequence the cells and PHB are more visible. The thesis is also focused on chemical fingerprint analysis of cells by Raman spectroscopy. Several biomolecules were identified by measured Raman spectra for the particular samples.
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Mechanical and Transport Properties of Hybrid Hydrogel Systems
Klímová, Eliška ; Sedláček, Petr (referee) ; Kalina, Michal (advisor)
This master´s thesis deals with the study on mechanical and transport properties of hybrid hydrogel systems. Considering applications of hydrogels, especially in chemical industry, pharmacy, or eventually medical applications, for the study gellan and alginate-based hydrogels were selected. In order to compare individual characteristics physical and hybrid hydrogels were prepared. Gellan hydrogels were prepared in deionization aqua solution, calcium chloride dihydrate and tween 80 solution. Alginate hydrogels were prepared in calcium chloride dihydrate solution as well, and polyacrylamide with N,N´–methylenbisacrylamide. For the study of mechanical properties moisture analyser and rheology measurements were selected. Transport properties were studied using the diffusion experiments combined with UV-VIS spectroscopic detection. Concluding of this thesis is summarization of measured values, which provides comprehensive review of the problematics. It was discovered that the conveniently selected concentrations of structural components of hydrogel matrix and the additives can influence both the mechanical as well as the transport properties of studied hydrogels.
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Car differentials
Sedláček, Petr ; Ramík, Pavel (referee) ; Kaplan, Zdeněk (advisor)
This bachelor thesis deals with differentials with emphasis on self-locking differentials. The first part deals with the transmission system, followed by a part introducing the issue of differentials, their distribution and description of individual structures. At the end of the work we find the solutions of self-locking differentials with focus on Torsen type differentials. The aim of the work was to create a comprehensive overview of differential issues.
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