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Computer modelling of mixture formulas of composite materials
Matoušek, Jiří ; Frk, Martin (referee) ; Rozsívalová, Zdenka (advisor)
Submitted work engage in modelling of progressions of dielectric variables and aplication of mixture formulas for solution of composite materials in dependency on frequency. Theoretical part engage in theory of dielectric materials and composite materials and contains summary of basic mixture formulas. A part of work is programm which can be used in education. It allows modelling of permitivity, loss factor and loss number in dependency on frequency and Cole-Cole circle diagram in materials. In mixtures modelling of Maxwell´s, Bőttcher´s and Lichtenecker´s mixture formulas.
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Modelling and behaviour of composite systems in AC electric field
Matoušek, Jiří ; Frk, Martin (referee) ; Rozsívalová, Zdenka (advisor)
This work deals with modeling of progression of dielectric variables and mixture formulas for solution of properties of composite materials in dependency on frequency. Theoretical part of the work explains physical principles of polarisation mechanisms and influence on dielectric constant with changing temperature and frequency. In theoretical part processes inside the composite material, which is in electrical field are described. The work contains summary of mixture formulas and methods of their derivation. Program for use in education is a part of the work. It allows modelling of progression of dielectric variables in dependency on frequency and Cole-Cole circle diagram. In mixtures it allows modelling of frequency dependencies of dielectric constant in accordance to Maxwell's, Bőttcher's and Lichtenecker's mixture formulas.
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Axisymmetric antennas with metamaterials
Roman, Pavel ; Fiala, Pavel (referee) ; Raida, Zbyněk (advisor)
This project is focused on computer modeling of so-called meta-materials, and on the exploitation of metamaterials in the design of electrically small antennas. For modeling, COMSOL Multiphysics 3.3 was used. Simulations were focused on impedance matching of antennas. Antennas with metamaterials were compared with corresponding conventional antennas without metamaterial layers. The project does not investigate the creation of metamaterials; the project concentrates on their influence on crucial parameters of antennas. Next step this project is focused on optimalization this structure in program Matlab version R2009b. We used optimalization method PSO (swarms of particles) and results are comparing whit results calculating in COMSOL program.
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Application of nanofiller in electroinsulating materials
Mohyla, Petr ; Rozsívalová, Zdenka (referee) ; Frk, Martin (advisor)
This project deals with calculation parts of complex permittivity varnish samples which is filled by nanoparticles of metal oxides. Opening of this project deals with theory of dielectric and effects in dielectric, theory of compounds and expressions in composite systems. Following topic is theory of nanoparticles and nanotechnologies and summarize adjusted results about this branch of knowledge. In practical part of work is include method which was use to make varnish samples filled by nanoparticles, prepare to measurement methods and whole results of measurement. In the end of work is analysis influence of filler particles each filler types to dielectric material and results verified mixture mathematical expressions.
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Modification of electroinsulating varnish with ground mica
Drápal, Aleš ; Frk, Martin (referee) ; Rozsívalová, Zdenka (advisor)
This master's thesis focuses on composite systems based on varnish combined with different filler ratios of micronized mica. The aim is to analyse impact of the filler on dielectric properties of the varnish, i.e. relative permittivity and loss factor as functions of frequency as well as charging and discharging currents as functions of time. Dielectric mixture formulas are applied on relative permittivity values. Calculated and measured values are compared.
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Computer modeling of meta-materials
Beran, Jaroslav ; Kovács, Peter (referee) ; Oliva, Lukáš (advisor)
The diploma thesis deals with metamaterial structures. Metamaterials are periodic structures, which have got permittivity or permeability, eventually both parameters, negative. Test is applied on three basic structures: Split Loop Array; Spiral Array a Double Spiral Array. For each structure is made dispersion diagram and are monitored S – parameters. Test is run in Ansoft High Frequency Structure Simulator and CST Microwave Studio software. Are monitored bandgaps and when structure is as left – handed medium or right – handed medium. Results are compared with results in literature.
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