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Characterization of scanning transmission electron microscopy images of thin biological sections
Novotná, Veronika ; Nebesářová,, Jana (referee) ; Krzyžánek, Vladislav (advisor)
Diplomová práce popisuje fyzikální principy mikroskopů TEM, SEM a STEM spolu s jejich vhodností pro pozorování vzorků citlivých na elektrony, jako jsou zalévací média či biologické vzorky. Dále je popsána příprava vzorků pro STEM (TEM) a popis interakcí, ke kterým dochází mezi primárním elektronovým svazkem a vzorkem. Součástí práce je také pojednání o zpracování mikroskopických obrazů s podkapitolou o metodách kvantitativního porovnání obrazů ze STEM. Praktická část práce je zaměřena zejména na měření úbytku hmoty zalévacích médií (Epon, Spurr, LR White) způsobený primárním svazkem elektronů v nízkonapěťovém STEM. Ultratenké řezy několika tlouštěk byly zkoumány při různých nastaveních mikroskopu (urychlovací napětí, celková dávka, proud svazku, čištění povrchu vzorku a komory mikroskopu) a zobrazovacích módech (světlé a tmavé pole). Dále jsou zkoumány také biologické vzorky Krásnoočka štíhlého (Euglena gracilis) zalitého v pryskyřicích Epon a Spurr. Nasbírané snímky, vytvořené algoritmy a získané výsledky jsou diskutovány a zhodnoceny.
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The consequences of an aging population in the financing of the pension system
Novotná, Veronika ; Fiala, Tomáš (advisor) ; Miskolczi, Martina (referee)
This thesis describes the pension system of the Czech Republic. The aim of this thesis is to analyse the ways of financial funding of the pension system based on current demographic progression and future demographic prognosis in the Czech Republic. The analysis has been done in accordance with the aging of Czech population in the recent years. Various suggestions for changes in the Czech pension system and some pension reform issues in some foreign systems vs. Czech system are also part of this thesis. The final part concerns with the overall assessment of the analysis and potential changes.
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Analysis of conditions of health science for children with hearing disability at school
NOVOTNÁ, Veronika
The aim of my bachelor theseis was to gain the achal informatik about conditions of children with hearing disability in schools of Southern Bohemia. In my work I´ve been focusing on children of the age of 8 ? 15 yeares. The theoretical section is focused on the terms which are closely related to the topic, disability, child with hearing disability, evolution of the child with hearing disability, aids ? for example hearing aids, cochlear implants and thein usage in the school environment, by child´s with hearing disability parent, in the subjekt Health Education in the school and South Bohemian Region. The practical section brings knowledge from the area of the given isme, the methods used in the Molnár´s and Creswell´s research are described. The opinions of the respondentes on the research were examined on the specimen of the children with hearing disability and their teachers in South Bohemian Region by questionnaire of my own construction can be concluded that the level of the elementary schools in the education of the subject. In the edn of theseis the conditions of the children with hearing disability on the subjekt Health Education are summarized and possible recommendations for practice are given. Schools have positive attitude in integrating the children with hearing disability and seem to be very open in this topic.
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Beam damage of embedding media sections and their investigations by SEM
Krzyžánek, Vladislav ; Novotná, V. ; Hrubanová, Kamila ; Nebesářová, J.
A scanning transmission electron microscope (STEM) is useful device combining features of scanning and transmission electron microscopes. The sample in form of the ultrathin section is scanned by the electron probe and the transmitted electrons are detected. Except the dedicated STEMs this mode can exist as options in both TEM and SEM. The STEM based on the SEM equipped by a transmission detector was used for presented experiments. Nowadays, such low voltage STEM is more often used, and in many cases replaces the typical TEM. Here, we report investigations of embedding media that are typically used for TEM preparation of biological samples. The STEM detector in SEM may be able to detect both bright-field and dark-fields images. It uses much lower acceleration voltages (30 kV and below) than conventional TEM or STEM. However, materials like biological samples, polymers including embedding media are electron beam sensitive. Two the most important beam damages are the mass loss and the contamination. Both types of damages depend on the used electron energy and the electron dose applied to the sample. The mass loss depends on the sample composition, and the contamination results from the poor vacuum in the specimen chamber of the SEM, cleanness of the sample surface, etc.
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