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Effect of corrosion environment on the long-term stability of composite material to enamel and dentin bonds
Dudek, Michal ; Bradna, Pavel (advisor) ; Veverka, Jan (referee) ; Halačková, Zdena (referee)
Introduction: Adhesive technology represents a significant advancement among different treatment options of dental caries. Its advantages involve not only highly aesthetic reconstructions, but also ability to preserve hard dental tissues compared to more traditional filling materials such as amalgam, where the material retention was achieved through undercuts. A potential of adhesive technology to arrest progression of an incipient caries has triggered its wider use in dental caries management, potentiated by an ongoing development of new adhesive systems and composite materials that assure an acceptable long-term stability of adhesive reconstructions. Adhesive bonds of dental reconstructions are in the oral cavity constantly challenged by various mechanical, chemical and biological factors. One of the chemical agents with detrimental potential is peroxide bleaching gel used for teeth brightening. Currently bleaching belongs to the most frequent cosmetic dental procedures. The active ingredient of bleaching gels is hydrogen peroxide or its precursors. It is assumed that free oxygen radicals released from peroxides attack double bonds of chromophore molecules captured within the tooth tissues. Because of the high reactivity and nonspecific nature of these oxygen radicals, they may affect also dental...
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Analysis of childern's summer camp Bulovka
Dočkal, Petr ; Veverka, Jiří (advisor) ; Nováková, Daniela (referee)
Anotation The thesis is focused on leisure time and activities for children during the summer holidays. Based on the analysis of the specific camp - NOO Bulovka are formulated basic rules about the requirements of a good camp. At the same time are compared different components of the program including evaluation. In addition to working with literature and other sources the author used personal experience and the results of his observation. Key words leisure time, leisure time education, children's summer camp, NOO Bulovka, analysis of summer camp program
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After-school recreational activities for children and youth in foster homes
Kříženecká, Monika ; Veverka, Jiří (advisor) ; Nováková, Daniela (referee)
Title: After-school recreational activities for children and youth in foster homes Author: Monika K íženecká Department: Department of Education Supervisor: Mgr. Ji í Veverka Abstract: I work at special school as a teaching assistant and tutor. The mission of my work is to assist the teacher in teaching and as much as possible to fulfill the principle of individual approach to pupils. Furthermore, as a professor of free time I try to offer the best after-school and leisure activities and leisure time to fill the child so that happy. In my work I examine the extracurricular activities of interest in children in an orphanage, opinions and attitudes on the subject , not only children but also the public. Keywords leisure, hobbies , children's home, child , youth Souhlasím s p jčováním diplomové práce v rámci knihovních služeb.
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Alimentary intake of fluoride in preschool children in dental caries prevention
Oganessian, Edgar ; Broukal, Zdeněk (advisor) ; Štípek, Stanislav (referee) ; Veverka, Jan (referee)
The primary prevention of dental caries includes the regular reduction of dental plaque, the adequate nutrition with reduced frequency of sugar intake and the application of topical and/or alimentary fluorides. The caries-protective effect of fluorides is based on the stabilization of demineralization/remineralization processes in the surface of teeth. The alimentary fluoride intake involves its nutritional sources, fluoride supplements when administered and unintentionally swallowed fluoride toothpastes. The fluoride intake, besides its verifiable and significant contribution to the control of cariogenic conditions in the oral cavity, brings some risk in the period of permanent teeth development. That is why the fluoride intake in childhood ought to be well set up and controlled for achieving the maximum benefit in caries reduction and for minimizing the risk for the enamel development. The assessment on fluoride content in its most significant nutritional sources and the model estimates of fluoride intake in preschool children have been conducted with the aim at contributing the solution of the benefit/risk strategy of fluoride caries prevention. The fluoride content was estimated in bottled waters for preschool children, in instant milk formulas, in herbal teas for children and in instant products of...
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Effect of polymerization light units on setting of composite materials with different photoinitiator systems
Froněk, Jan ; Bradna, Pavel (advisor) ; Veverka, Jan (referee)
The work is focused on monitoring the impact of several different types of polymerization lamps to hardening of dimethacrylate based composite materials with camphorquinone and acylphoshine oxide initiation systems and epoxy based composite material. Variable parameters of the polymerization lamps were light output power, the emission spectrum, the thermal emission and the power distribution across the face of light guides. Extent of polymerization was evaluated by measuring the surface hardness, parameters of lamps were evaluated by radiometric methods, the temperature change by a thermocouple. The power distribution across the face of light guides was measured by image analysis and verified by measuring the distribution of hardness in the irradiated area of polymerized material. The goal was to obtain independent data on the influence of controlled parameters on the polymerization of composite materials used in dentistry, with an impact on the life of composite reconstruction of teeth and body burden of substances leached from poorly polymerized material.
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Lepidopteran fauna of the Hořovice region and its using in pedagogical practise
Veverka, Jan ; Hanel, Lubomír (referee) ; Dostál, Petr (referee)
Results of a survey of the lepidopteran fauna of the Hořovice region (Beroun District, Central Bohemia) carried out in the years 1982-2009 are presented. 49 localities were explored altogether, emphasis was given on the cadastre of Hořovice town (grid mapping code 6149) and Kleštěnice village (grid mapping code 6249). Most of the studied area is strongly influenced by industrial and agricultural use; large forests of the Křivoklátsko area and the Brdy highlands reach only marginally there. The three main goals of the rigorous theses are as follows: 1) to map distribution of all species of butterflies and moths of group so-called Macrolepidoptera (Lepidoptera: Macrolepidoptera) that belong to the fauna of the Hořovice region; 2) site class assessment on the basis of results of a survey of the lepidopteran fauna; 3) Lepidoptera in the pedagogical process. Altogether, 493 species in 16 families of Macrolepidoptera have been found (41% of the macrolepidopteran fauna of the Czech Republic). Relativelly most species have been recorded in the families Drepanidae, Sphingidae, Lasiocampidae and Notodontidae. Rare and otherwise remarkable species are commented.
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Sǿren Aabye Kierkegaard (1813 - 1855) - Life, Faith and Theology
Králik, Roman ; Kučera, Zdeněk (advisor) ; Veverka, Lukáč Ján (referee) ; Sapík, Miroslav (referee)
Søren Aabye Kierkegaard (1813 - 1855) Život, víra a teologie Søren Aabye Kierkegaard (1813-1855) Life, Faith and Theology PaedDr. Roman Králik The following dissertation pursues the topic of systematic theology. Its title is Søren Aabye Kierkegaard (1813-1855) with the subtitle Life, Faith and Theology. The aim of the dissertation is to acquaint the reader with the life, way of thinking and the spiritual struggle of one of the main figures of modern theology, Søren Kierkegaard.
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Apartment house, Boskovice
Veverka, Jiří ; Peterka, Tomáš (referee) ; Müller, Jan (advisor)
The work deals with the design and development of the design documentation of an apartment building situated in the cadastral area of the town of Boskovice. The documentation contains all the requirements according to the valid regulations. The designed four-floor apartment building is situated in gently sloping terrain. There are 13 flats in this apartment building. A balcony or a terrace belong to each of the flats. From the ground floor apartments there is an entrance to the garden. The flats are designed to meet the requirements of the present day. There is a car park in front of the buiding. The vertical loadbearing structures are lined with clay blocks. The building is covered with a one-layer coating flat roof with a load-bearing layer of monolithic reinforced concrete boards. The insulation of the building is provided by a contact thermal insulation system. Fire safety, energy saving and thermal protection is ensured.
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ELECTRON BEAM REMELTING OF PLASMA SPRAYED ALUMINA COATINGS
Matějíček, Jiří ; Veverka, J. ; Čížek, J. ; Kouřil, J.
Plasma sprayed alumina coatings find numerous applications in various fields, where they enhance the properties of the base material. Examples include thermal barriers, wear resistance, electrical insulation, and diffusion and corrosion barriers. A typical structure of plasma sprayed coatings, containing a multitude of voids and imperfectly bonded interfaces, gives them unique properties - particularly low thermal conductivity, high strain tolerance, etc. However, for certain applications such as permeation barriers or wear resistance, these voids may be detrimental.\nThis paper reports on the first experiments with remelting of plasma sprayed alumina coatings by electron beam technology, with the purpose of densifying the coatings and thereby eliminating the voids. Throughout the study, several parameters of the e-beam device were varied - beam current, traverse velocity and number of passes. The treated coatings were observed by light and electron microscopy and the thickness, structure and surface morphology of the remelted layer were determined and correlated with the process parameters. Based on the first series of experiments, the e-beam settings leading to dense and smooth remelted layer of sufficient thickness were obtained. In this layer, a change of phase composition and a marked increase in hardness were observed.\n
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