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Organomineral gel as a new concept of structural and colloidal characterization of soils
Kundera, Ondřej ; Záhora, Jaroslav (referee) ; Sedláček, Petr (advisor)
The aim of this study is the organomineral gel contained in soil, mainly the characterization using electron microscopy and available analytical methods like IR-spectrometry, thermal analysis, X-ray crystallography and emission spectrometry. The knowledge from this study may help to define function and significance of this gels to soils and nature. The theoretical part of this thesis deals with soil, humic substances and minerals occurring in soils. The experimental part solves especially the structure and further characterization of organomineral gels.
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Aminoclays - optimization of preparation and characterization
Plotěná, Michaela ; Sedláček, Petr (referee) ; Pekař, Miloslav (advisor)
The objektive of this paper is to give an overview of synthetis, properities and application of magnesium phyllosilicate with 3-aminopropyl functional groups (aminoclay). The research in this paper focuses on preparing aminoclay, specifically to prove the prescribed procedure and its modifications. The structure of the final product was verified by X-ray analysis and scanning electron microscope. The main motivation is the synthesis of aminoclay opportunities in the pharmaceutical industry. Aminoclay would serve as an adsorbent that would ensure greater bioavailability of the drug.
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Preparation and application of metal and semiconductor nanostructures
Hrubý, Jakub ; Kolíbal, Miroslav (referee) ; Šimšíková, Michaela (advisor)
Tato práce se zabývá teoretickými základy přípravy, charakterizace a možnými aplikací nanostruktur. V experimentální části je nastíněna syntéza a charakterizace nanostruktur. Ušlechtilé kovy jsou zastoupeny zlatem a stříbrem. Oxid zinečnatý jakožto II--VI polovodič a kompozit oxidu zinečnatého a oxidu měďnatého byly také syntetizovány bottom-up metodou. Připravené částice tvořily různé tvary, jako například kuličky, tyčinky, dlaždičky a takzvané nanokytičky. Částice byly posléze charakterizovány. Optickou mikroskopií byl proveden přibližný odhad morfologie. Skenovací elektronový mikroskop byl použit pro detailní pohled do struktury vzorku. Další charakterizační metody jako fotoluminiscence a absorbance byly využity u CuO/ZnO kompozitu.
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NEW PRINCIPLES OF GATE CAPACITANCE CHARACTERIZATION FOR SIGMA-DELTA MODULATORS
Sutorý, Tomáš ; Ďuračková, Daniela (referee) ; Husák, Miroslav (referee) ; Kolka, Zdeněk (advisor)
This thesis deals with the utilization of new principles of characterization of gate capacitances for sigma-delta modulators. Sigma-delta modulators are the integral part of sigma-delta analog-to-digital converters. The proposed new method is characterized by high resolution and modest requirements for laboratory equipment. It allows characterizing capacitances whose values are within the range which is used in sigma-delta modulators. The thesis contains description of the new method, the analysis of measurement accuracy and experimental results.
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Measurement of local characteristics of passive electrical devices
Šikula, Radek ; Kubánek, David (referee) ; Tománek, Pavel (advisor)
Bachelor thesis is focused on the newly conceived local measurement of electrical or photoelectric devices characteristics. According to Moore's law dimensions of active components on the chips diminish. Therefore effort to obtain corresponding reduction of passive electrical components, while improving, or at least maintain their parameters, is also challenged. It turns out that the problems associated with device reducing are connected with existence of physical limits of materials, and ultimately with the impossibility to measure local properties of electrical components using conventional electric methods. Especially in the range of physical limits, a serious problem of defects in materials appears. Due to that the small size components can greatly affect the efficiency, performance, durability and reliability of devices. Measurements made on the passive and active components show a higher resolution of defects on the surface of selected parts than current methods allow. 1) It follows from the results of measurement on capacitors that there are several possible reasons why breakdowns occur, e.g. mechanical defects or the presence of impurities and/ or oxide crystals in the dielectric. 2) Measurements taken at a photodiode allowed visualize minority carriers current, and view their lifetime. Moreover, they also show that the minority carrier lifetime comes mainly from bulk recombination.
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Isolation and characterization of autochthonous yeasts from interspecific varieties of grapes
Dlapalová, Kristýna ; Vadkertiová, Renata (referee) ; Vránová, Dana (advisor)
The aim of this thesis is the isolation and identification of yeasts obtained from the wine berries and the characterization of the collection yeast by using processes of PCR - RFLP. The type yeasts were obtained from the collection of yeasts of CCY in Bratislava, yeasts from the wine berries were collected from the species of Hibernal wine from the wineries of Štěpán Maňák. Identification of individual yeast is then based on analysis of the DNA segment in the area of 5,8S - ITS using primers ITS1 and ITS4. The restriction analysis was performed using restriction endonucleases HaeIII, HinfI, HhaI a TaqI(a). Restriction analysis is used to chopp the DNA to specific sections that are characteristic for each microorganism. For the assesment of the genetic similarity analyzed yeasts the BioNumerics software has been used. BioNumerics processes the results using cluster analysis using Jaccard´s coefficients.
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Elemental analysis of dendrochronological Norway spruce sample
Zámečník, Karel ; Hraníček, Jakub (advisor) ; Kozlík, Petr (referee)
The subject of this bachelor's thesis is the determination of lithium, sodium, magnesium, potassium, calcium, manganese, iron, zinc, selenium, rubidium, strontium, cadmium, antimony, cesium, barium, and thallium in dendrochronological samples of Norway spruce using inductively coupled plasma mass spectrometry. The samples of the Norway spruce were collected in the autumn of 2018 on the southern slope of hill Melechov in the Vysočina region. The stem sample was first divided into pieces according to the distance from the bark and labelled A1a to A1g. The ash sample was obtained by burning a cross-section of the stem and separating the bark, from which the A3b sample was created. The remaining two samples were made up of needles and twigs and labelled as samples E and F. For elemental analysis, the samples needed to be converted into a solution, which was achieved by dissolving them in a mixture of hydrochloric, nitric, and hydrofluoric acid, using a microwave digestion device. After dissolution, a solution of boric acid was added to each sample solution to complex any unreacted hydrofluoric acid, which could damage the internal components of the ICP-MS. Calibration solutions were then created with concentrations of 0,0016; 0,008; 0,04; 0,2 and 1,0 mg/l from stock solutions containing the analysed...
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Sputtering of nitride layers using Kaufman ion-beam source for bioelectronics applications
Jarušek, Jaromír ; Chmela, Ondřej (referee) ; Gablech, Imrich (advisor)
In this work, nitride layers, their applications in bioelectronics, and methods of chemical vapour deposition and physical vapour deposition are presented. The focus of this work is the preparation of titanium nitride thin films by reactive sputtering using Kaufman ion-beam sources. Thin films were deposited on silicon wafers and microslides. Deposited titanium nitride thin films are characterized by X-ray diffraction, four-point probe sheet resistance measurement and profilometry to determine residual stress.
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Analysis of selected elements in dendrological sample of spruce trunk
Pastrňáková, Aneta ; Hraníček, Jakub (advisor) ; Šíma, Jan (referee)
The aim of this bachelor thesis was to determine selected elements, specifically iron, manganese, sodium, potassium, calcium, magnesium, barium, copper, zinc, strontium and aluminium in the sample of a spruce wood, taken from a dry tree from an area of South Bohemia. As a suitable and sufficiently sensitive method an atomic absorption spectrometry with flame atomization was used in this bachelor thesis. Before the analysis optimal conditions for the determination of these elements were experimentally found. The beam height above the burner edge and the acetylene flow rate were optimized depending on the type of oxidant used. Under the optimal conditions, the basic characteristics of the determination of individual elements were determined. These characteristics include mainly the limit of detection and quantification, sensitivity and repeatability. Optimized methods for determination of the selected elements were further applied for the analysis of real spruce wood samples. These samples were prepared by decomposition of the wood in a microwave device in the presence of nitric acid. In order to suppress interference, the suitable reagents were added to the analyzed samples to determine the selected elements (sodium, potassium, magnesium, calcium, barium). In total, 22 samples of wood of different...
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Chromatograhic characterization of chiral and achiral separation systems
Kučerová, Gabriela ; Tesařová, Eva (advisor) ; Čabala, Radomír (referee) ; Ševčík, Juraj (referee)
Dissertation thesis is a 5-publications' collection concerning characterization and application potential of cyclodextrins, polysaccharides and macrocyclic antibiotics based chiral stationary phases. The effects of stationary phase and mobile phase are studied. This approach ensures the complex insight into separation systems studied. Systems with different nature of chiral selector were studied by HPLC. Namely, macrocyclic antibiotics and derivatized polysaccharides were used for experiments. Former ones provided better results for enantioseparation of non-coded amino acids than latter ones. Dynamic coating procedure was used for preparation of a new chiral stationary phase. Characterization of new cationic cyclodextrin based chiral stationary phase was performed. Linear free energy relationship method was used for characterization of two different separation systems, i.e. newly prepared stationary phase and commercially available stationary phase. Based on results obtained, newly prepared stationary phase showed better results for separation of different achiral groups of analysts. New stationary phase prepared by dynamic coating was compared with chromatographic system, in which the chiral selector was used as a mobile phase additive. The chiral selector used for the two different approaches was...
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