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Nanophotonics
Dvořák, Petr ; Rezek, Bohuslav (referee) ; PhD, Jakub Dostálek, (referee) ; Šikola, Tomáš (advisor)
This thesis deals with an experimental research of the surface plasmon polaritons (SPPs) using Scanning Near-field Optical Microscopy (SNOM). The first chapter provides theoretical background and a description of most of the physical phenomena and relevant dependencies studied in this work. These dependencies include the dependence of the resulting SPP image on homogeneity, polarization, wavelength and phase of the illumination, on the geometry of the interference structures and on the tilt of the sample with respect to the illumination. Further, this work presents a new experimental method which, using the numerical simulations or SNOM measurements, allows to estimate the sensitivity of SNOM probe to detect the individual electric intensity components of the near-field. At the end of the thesis, the work presents a new microscopic technique which enables a 3D quantitative imaging of phase distribution above the plasmonic metasurfaces.
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Aprotic electrolytes for supercapacitors
Musílek, Václav ; Knotek, Tomáš (referee) ; Dvořák, Petr (advisor)
This master´s thesis deals different types of the aprotic electrolytes for supercapacitors and investigates by impedance spectroscopy to conductivity and method cyclic voltametry to measure dimension potential windows. Used aprotic solvents: propylencarbonate, dimethylsulfoxide, N, N dimethylformamide, ethylencarbonate, dimethylcarbonate, diethylcarbonate and acetonitrile. In the aprotic solvents were appended salts: LiClO4, NaClO4, KClO4, LiBF4, LiPF6, TEABF4 and TMABF4. From these compounds were prepared solutions with the different molar concentrations.
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Fabrication and characterization of plasmonic nanostructures
Bačo, Ondřej ; Kvapil, Michal (referee) ; Dvořák, Petr (advisor)
This bachelor thesis deals with fabrication and characterization of plasmonic nanostructures. Graphene on a doped silicon substrate with a 285 nm thick layer of silicon dioxide was used for fabrication of these structures. Graphene ribbons with width in the order of hundreds of nanometers were prepared using electron beam lithography (EBL) and reactive ion etching (RIE). Steps in fabrication process were monitored utilizing optical and atomic force microscopy (AFM). Prepared graphene nanostructures were characterized with scanning electron microscope (SEM) and Fourier transform infrared spectrometer (FTIR).
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Properties of carbon materials for supercapacitors
Štorek, Ondřej ; Dvořák, Petr (referee) ; Sedlaříková, Marie (advisor)
The Master’s Thesis deals with supercapacitators based on principle of eletrical double layer. At the outset there is an explanation of supercapacitor working principal. We discussed advantages and disavantages supercapacitators compared with other related elements in electrotechnics. Materials based on carbon and their structure for production supercapacitators are described too. In next part of Thesis we mention different methods and techniques for the measurement and the evaluation of supercapacitators‘s capacities. Optimal materials for production supercapacitators are presented in conclusion.
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DC/DC converter 24 V / 320 V / 60 W for a back-up supply source with a galvanic separation
Dvořák, Petr ; Martiš, Jan (referee) ; Vorel, Pavel (advisor)
This bachelor‘s thesis deals with the design, dimensioning and realization of a DC/DC 24 V / 320 V converter with a output power of 60 W. In the first part there is a short description of the linear stabilizer and then the switching sources with their dismemberment. Based on that chapter, was selected the flyback converter. The second part deals with components design and description of the control circuit. At the end, the construction of the converter with the verification measurement records is shown.
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Dynamic electroneurostimulation and electrical properties of skin
Špeta, Marek ; Dvořák, Petr (referee) ; Špinka, Jiří (advisor)
The focus of this diploma thesis is on theoretical basics of dynamic electroneurostimulation, which is an effect of electrical signal on acupuncture points of skin. This technology is used in devices made by russian DiaDENS company. Practical part of this thesis covers design of human skin impedance model. Especially derivation from three-element Cole-Cole model. Elementary, there is design of equivalent circuit of constant phase element and its incorporation into circuit. Then this circuit is designed, simulated and produced. Resulting product is used as a load to measure the characteristics of the DiaDENS device.
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IPv6 Protocol Implementation Concept in Company
Dvořák, Petr ; Dolníček, Petr (referee) ; Ondrák, Viktor (advisor)
Diploma thesis is focused on IPv6 protocol implementation in real company´s enviroment. In the beginning we are introduced with theoretical knowledge about this protocol. After analysis of current state of XXX spol s r.o. we can use this knowledge in practical part of thesis for proposal of possible solutions including physical devices.
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Electron beam lithography on non-conductive substrates
Hovádková, Zuzana ; Šamořil, Tomáš (referee) ; Dvořák, Petr (advisor)
The expansion of electron beam lithography has been really fast during last years. It is mostly because its capability to create big structures with a fine resolution. This study focuses on electron beam lithography on non-conductive substrates, exactly on glass. The lithography on glass is mostly used in life sciences. Because of the transparence of the substrate and its non-toxicity it can be used for cell adhesion. In the experimental section there are shown and compared two techniques how to compensate the charge accumulated on the top of the surface.
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Optical properties of infrared plasmonic antennas fabricated by FIB technique
Biolek, Vladimír ; Dvořák, Petr (referee) ; Kvapil, Michal (advisor)
The bachelor thesis deals with plasmonic nanostructures for mid-infrared region of electromagnetic spectrum. In the first part, there are discussed theoretical description of electromagnetic field and description of properties of plasmonic nanostructures. Then the manufacturing methods of the plasmonic nanostructures for mid-infrared region of electromagnetic spectrum are discussed using focused ion beam, and measurement of these nanostructures are discussed using Fourier transform-infrared spectroscopy.
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