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Short fiber reinforced composite for dental use: preparation and characterization
Henkrichová, Jana ; Přikryl, Radek (referee) ; Poláček, Petr (advisor)
This diploma thesis studies short fiber reinforced composites for dental applications. Barium particulate filler, nanosilica and short glass and polyvinylalcohol fibers were added to the matrix consisting of four dimethacrylate types of monomers. The effect on material properties was observed. For characterization of different types of composite materials following methods were used: thermogravimetric analysis (TGA), dynamic mechanical analysis (DMA), three point bending test for notched and un-notched samples and scanning electron microscopy (SEM). Viscoelastic properties, modulus of elasticity and strength, critical values of stress intensity factor and strain energy release rate and polymerization shrinkage of composite materials were determined. It is possible to improve these properties of composite materials by adding short fibres to particulate reinforced composite. To make this modification more efficient, it is necessary to change surface treatment of fibres and preparation method of short fiber reinforced composites. Viscosity of material has raised after adding short fibers and processing of these types of dental material in dental laboratory is considered difficult to provide.
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Optimization of interfaces in long-fiber reinforced dental composites
Henkrichová, Jana ; Poláček, Petr (referee) ; Přikryl, Radek (advisor)
This bachelor's thesis is dealing with study of fiber reinforced dental composites. Important properties of dental polymers, used fibers and options of their treatment were characterized. The aim of the thesis is to design the fiber surface modification by low temperature plasma to improve the adhesive bond strength and fracture characterization of the composite. The strength of the bond was tested by three point tensile tests by special device. Refractive characteristics and impact fibers wetting by matrix was determined by confocal microscopy.
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Analysis of monthly time series of temperatures at chosen stations in Europe
Henkrichová, Jana ; Helman, Karel (advisor) ; Řezanková, Hana (referee)
The bachelor thesis is focused on the analysis of monthly time series of temperatures at nine meteorological stations in Europe between the years of 1951 and 2015. The data were obtained from the database of The European Climate Assessment & Dataset. The geographical position data of chosen stations consist of points in an imaginary grid throughout Europe. The purpose of this bachelor thesis is to compare the development of time series via basic characteristics, to explore the differences due to geographical position and to gain some information about the development of temperature in time via statistical methods. The main object of interest is the location of Praha - Klementinum. Some additional goals are testing the measure of independence of temperatures on the geographical latitude, verifying the continental influence on the climate and checking the shapes of distributions of temperature time series.
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Short fiber reinforced composite for dental use: preparation and characterization
Henkrichová, Jana ; Přikryl, Radek (referee) ; Poláček, Petr (advisor)
This diploma thesis studies short fiber reinforced composites for dental applications. Barium particulate filler, nanosilica and short glass and polyvinylalcohol fibers were added to the matrix consisting of four dimethacrylate types of monomers. The effect on material properties was observed. For characterization of different types of composite materials following methods were used: thermogravimetric analysis (TGA), dynamic mechanical analysis (DMA), three point bending test for notched and un-notched samples and scanning electron microscopy (SEM). Viscoelastic properties, modulus of elasticity and strength, critical values of stress intensity factor and strain energy release rate and polymerization shrinkage of composite materials were determined. It is possible to improve these properties of composite materials by adding short fibres to particulate reinforced composite. To make this modification more efficient, it is necessary to change surface treatment of fibres and preparation method of short fiber reinforced composites. Viscosity of material has raised after adding short fibers and processing of these types of dental material in dental laboratory is considered difficult to provide.
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Optimization of interfaces in long-fiber reinforced dental composites
Henkrichová, Jana ; Poláček, Petr (referee) ; Přikryl, Radek (advisor)
This bachelor's thesis is dealing with study of fiber reinforced dental composites. Important properties of dental polymers, used fibers and options of their treatment were characterized. The aim of the thesis is to design the fiber surface modification by low temperature plasma to improve the adhesive bond strength and fracture characterization of the composite. The strength of the bond was tested by three point tensile tests by special device. Refractive characteristics and impact fibers wetting by matrix was determined by confocal microscopy.
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