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Biomedical applications of polycaprolactone nanofibrous mats
Dvořák, Pavel ; Přibyl,, Jan (referee) ; Zajíčková, Lenka (advisor)
The diploma thesis deals with the treatment of polycaprolactone (PCL) nanofibers. PCL fibers were subjected to the deposition of plasma amine polymers in a low pressure pulsed radiofrequency capacitively coupled discharge using cyclopropylamine monomer (CPA). Collagen as an extracellular matrix (ECM) protein was immobilized and cell proliferation on the modified nanofiber surface was monitored. Untreated PCL fibers were also subjected to the deposition of an antibacterial copper layer, and the fibers were characterized by scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), and energy dispersive spectroscopy (EDX).
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Temporally and spatially resolved diagnostics of an electric arc
Holcner, Oldřich ; Šimek, David (referee) ; Kloc, Petr (advisor)
This batchelor thesis "Temporally and spatially resolved diagnostics of an electric arc" deals with the investigation of plasma temperature in an arc formed by evaporation of copper wire. It is an optical method based on determination of temperature from intensity of spectral lines. In this batchelor thesis we explain how spectral lines are formed and how to determine the temperature. In the practical part we process discharge and show the time evolution of temperature at the measured points.
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Enhancement of optical diagnostics of the switching arc
Samohejl, Matěj ; Kloc, Petr (referee) ; Valenta, Jiří (advisor)
This master´s thesis si focused on determinig methodology of optical diagnostics of the switching arc using the high-speed camera Photron SA-X2. The thesis contains basic rules for proper setup of the measurement system and the rules to adjust the camera exposure. The experiments were performed on the prototype of a parametric switching chambre, while the majority of source materials was derived from the requirements of another study which was aimed on the movement of the electode spots. The process of the first adjustment of the camera, a record edit options for the presentation purposes and the process of the 3D model design of the switching arc in SketchUp software was stated. Paper contains a comparsion of the spectral filter effect and neutral density filter effect on the final record as well. The part of the work outputs are the 3D model of the switching arc and the supporting record editing software. The paper results show a degree of the inaccuracies in a optical diagnostics made from only one direction caused by the lack of the information about third dimension.
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Module for the detection of light elements in ferrous alloys by the Laser-Induced Breakdown Spectroscopy technique
Hrabal, Zdeněk ; Novotný, Karel (referee) ; Novotný, Jan (advisor)
Tato diplomová práce je zaměřena na analýzu lehkých prvků (tj. uhlík, sýra a fosfor) v železných slitinách pomocí metody laserem indukovaného plazmatu (LIBS). Hlavním cílem je vyvinout a implementovat nový modul, který bude umožňovat analýzu v hluboké ultrafialové oblasti (VUV), což je nezbytné jak pro stanovení chemického složení lehkých prvků v ocelích tak pro mnoho dalších aplikací metody LIBS. V první části je vytvořen přehled moderních přístupů optické emisní spektroskopie (OES) a rovněž jsou shrnuty tradiční techniky používané v metalurgii pro analýzu ocelí. Teorie absorpce ultrafialového záření vzduchem a optickými skly byla důkladně studována a shrnuta k získání potřebného teoretického základu k vývoji modulu. Před návrhem finální verze modulu byl navržen experimentální modul s cílem otestovat navržený koncept analýzy ve VUV oblasti metodou LIBS. Na základě testování byla navrhnuta finální verze založená na unikátním klínovém mechanismu. Funkční vzorek byl vyroben ve spolupráci s extérním výrobcem a vlastnosti modulu byly následně demonstrovány naměřením pěti certifikovaných ocelových standardů. Experiment určil limity detekce pro uhlík jako 0.028 hm.%. Nicméně, síra ani fosfor nebyly detekovány v žádném ze vzorků. Tato práce vytvořila modul nezbytný pro budoucí zkoumání metody LIBS v oblasti VUV v Laboratoři laserové spektroskopie v Brně.
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Metallization of technical plastics for lightweight traffic components with reduced fuel consumption
Sanetrníková, Dominika ; Boušek, Jaroslav (referee) ; Šimůnková, Helena (advisor)
The beginning of this thesis is dedicated to polymeric materials, which include plastics an composites. Plastics are shortly divided into two groups, thermoplastics and thermosets. The following part is the use of plastics and composites in traffic industry and briefly this work focuses on techniques of recycling of this materials. This work also focuses on the techniques of thin film deposition, electroless plating, electrodeposition as well and plating in the vacuum environment. special techniques of thin film deposition are also mentioned shortly. The coatings of polymer including cleaning and surface activation is introduced using various techniques including plasma treatment. The surface treatment of polyetheretherketone (PEEK) is included too. The final part describes performed experiments and discussion of results.
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Diagnostic of nitrogen post-discharge by optical emission spectroscopy
Kabeláčová, Kateřina ; Slavíček,, Pavel (referee) ; Mazánková, Věra (advisor)
The aim of this thesis is diagnose post-discharge nitrogen plasma with optical emission spectroscopy. There is long interest of investigated of nitrogen post-discharge plasma and study how to use it in theory as well as in practice. All results were measured with method of optical emission spectroscopy of post-discharge plasma. Discharge was generated by direct-current voltage generator with flowing regime. In this thesis was used for different series of experiments. First experiment was performed with adding water vapour into argon plasma. Measuring was processed at constant current 140 mA, voltage 1.5 V and pressure 1 000 Pa. It was changed flow rate and for each individual flow rate was measured in range 1–25 cm from end of active discharge. Second experiment was with adding nitrogen into argon plasma. Measuring was processed at constant current 140 mA, voltage 1.5 V and pressure 1 000 Pa. We were changing flow rate of nitrogen (0,2 sccm, 0,4 sccm and 0,8 sccm). For each individual flow rate was same experiment with changing distance from active discharge. Third experiment was about adding mercury vapour into nitrogen post-discharge. Measuring was processed at constant current 120 mA, voltage 3.5 V and pressure 1 000 Pa. Measuring was performed with two configuration: with diaphragm and without it. Last experiment was about adding air into argon plasma. Measuring was processed at constant current 140 mA, voltage 1.0 V and pressure 1 000 Pa. Temperature of outer face of tube was measured by thermocouple and infrared thermometer, was measured for last two experiments (argon – air and nitrogen). During experiments with pure nitrogen was visible phenomenon called pink afterglow which is manifested by noticeable increase pink coloration. Optical emission spectrums post-discharge was take at various range of wavelength. At argon with water vapour was 280–600 nm and at adding nitrogen into argon was at range 320–500 nm. At added mercury vapour into nitrogen was 320–600 nm. For experiment argon – air was wavelength range 320–600 nm. From results of experiments were designed dependencies of calculated intensity from measured spectra on distance from active discharge. Also were constructed dependencies of measured temperature on distance from active discharge.
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Control and measurement unit for plasma generators
Paulovics, Petr ; Boušek, Jaroslav (referee) ; Zemánek, Miroslav (advisor)
The diploma thesis deals with the issue of plasma generators. Specificantlly, the work focuses on the design of HMI devices for plasma generators, including the design of the control part of the generator. The main advantage of controlling the plasma generator using an HMI device is the ability to quickly change important parameters. The HMI device allows convenient switching of the generator output frequency without the need to interfere with the wiring, which leads to higher efficiency when working with the plasma generator. Another advantage of the HMI device is the display of all important information on the LCD display. The work deals with the basic theory of plasma and its use, the division of microcontrollers and the description of their peripherals, the selection of components used and their wiring. The last part of the work is devoted to the software of the plasma generator.
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Optimization of the experimental parameters for laser induced breakdown spectroscopy (LIBS) of selected plant samples
Prochazka, David ; Novotný, Karel (referee) ; Kaiser, Jozef (advisor)
This diploma thesis describes optimization of the experimental parameters for Laser-induced breakdown spectroscopy of plant samples. First part deals with the theoretical method of LIBS and explains the principles and terms. In the next part there is described device which was used for measurements. Main part of diploma thesis describes creation of program for measurement-automation. Main task of program was to solve the connection of autofocus on the sample with the sample automatic movement. Furthermore are described and elaborated specific measurements for optimization of the experimental parameters for Laser-induced breakdown spectroscopy of plant samples.
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