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Implementation of a Multipurpose Measurement System for (Sub)Terahertz Electron Spin Resonance Spectroscopy
Šedivý, Matúš ; Malik, Aamir Saeed (referee) ; Epel, Boris (referee) ; Vrba, Radimír (advisor)
Spektroskopie elektronové spinové rezonance (také nazývaná elektronová paramagnetická rezonance nebo jen EPR) zahrnuje metody, které zkoumají hmotu prostřednictvím nepárových elektronů. Jednou z progresivních metod EPR je rychlé skenování, které umožňuje pozorovat kinetiku chemických reakcí. Kromě toho nedávný vývoj vysokofrekvenčních součástkách rozšířil použití vysokofrekvenční EPR (HFEPR), které využívají sub-terahertzové až terahertzové vlny. Tato práce se zabývá propojením obou cest do HFEPR spektrometru s rychlým skenováním frekvencí (FRaScan), který byl nedávno vyvinut na CEITEC VUT. Na začátku je stručně uvedena základní teorie k EPR, následovaný přehledem přístrojového vybavení pro HFEPR. V praktické části je popsáno technické řešení spektrometru. Důraz je kladen na implementaci softwaru, pomocí kterého je spektrometr ovládán a měření jsou automatizována. Následně jsou ukázány příklady z měření pevných látek, konkrétně karbidu křemíku dopovaného vanadem (SiC:V), ftalocyaninu líthia (LiPc) a krystalu 1,3-bisdifenylen-2-fenylallylu (BDPA). Příklady demonstrují schopnosti spektrometru získat multifrekvenční vlnově spojitá EPR spektra a frekvenčně rozmítaná spektra v závislosti na teplotě a orientaci vzorku, a taky spektra pomocí rychlého skenování frekvencí
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Emisivity and its Impact on the Heat Conductivity
Gančev, Jan ; Hejátková, Edita (referee) ; Szendiuch, Ivan (advisor)
This work deals with the issue of emissivity and its impact on the heat dissipation.The first part describes the basics of thermal management, the issue of emissivity and its measurement. In the second, experimental part, are dedicated the emissivity values of examined specimens. These values are then used as initial conditions for the thermal simulation. In the last part are compared the measured results and the simulated results and is evaluated the impact of emissivity for the heat dissipation.
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Industrial Tester for Photometric Values of LED diodes Used in Automotive Signal Lighting
Gaži, Dominik ; Froehling, Kenneth (referee) ; Baumgartnerová, Alena (advisor)
V posledních letech zažili světlomety v autech obrovský technický rozvoj, který se podílel na jejich současné složitosti. Aby řidiči i zákazníci byli spokojeni, je využíváno různých technologií pro neustálé dosahování účinnějších a bezpečnějších světelných zdrojů. Společnosti usilují o minimalizaci ztrát ve výrobě ve snaze šetřit životní prostředí a konat ekonomicky. Tato práce se zabývá výzkumem osvětlovací techniky a návrhem jednoduchého a efektivního zařízení pro testovaní chyb LED plošných obvodů ve světlometech, to vše za účelem minimalizace strat. Dalším cílem je výzkum možností konstrukce takového zařízení z technologického hlediska.
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Design of compact spectrograph with shiftable spectral range based on transmission gratings
Malina, Jan ; Pořízka, Pavel (referee) ; Novotný, Jan (advisor)
The aim of this diploma thesis is to design a compact spectrometer with a transmission grating and a shiftable spectral range for the method of laser-induced breakdown spectroscopy (LIBS). The work in the theoretical part contains a basic description of spectroscopy and spectroscopic methods of LIBS, spectrometer and its individual parts. The practical part describes the spectrometer design procedure, introduces selected components and comments on the reason for their selection. Selected components are assembled into the final form of a spectrometer, which is further tested with the help of a simulation program to confirm its functionality. The result of the work is a comprehensive overview of the individual components of the spectrometer, aspects of its construction together with instructions and advice on its assembly, along with an example in the form of a designed set of commonly available catalog components.
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Fiber optic spectrometer
Krausová, Petra ; Münster, Petr (referee) ; Urban, František (advisor)
The purpose of this thesis is familiar with the problem of optical spectroscopy. The thesis describes the optical dispersion elements and spectral instruments. A separate chapter is devoted to Fourier spectroscopy, which in turn is based on a new technology SWIFTS described in the next chapter, in which the SWIFTS spectrometers compared with currently used spectral analyzers. The thesis then designs and evaluates experimental measuring which analyzes the detection of longitudinal distribution of radiation intensity in the optical fiber.
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Impact of the atmosphere on laser ablation of matters
Černá, Svatava ; Hrdlička, Aleš (referee) ; Pořízka, Pavel (advisor)
This thesis deals with a general overview of laser-induced breakdown spectroscopy - ablation of material and plasma formation when a change of the surrounding environment occurs. The aim is to establish ideal conditions for improving detection, which is difficult for some elements when the measurement takes place in the ambient atmosphere. This is the reason why we change the ambient conditions, the gas (air, helium, argon) and its pressure. Buffer gases (helium, argon) influence the development of the material ablation and quality of generated plasma. That is why we inspect the changes in the signal according to particular atmospheres (signal change in buffer gases compared to the ambient atmosphere). The first part of the thesis presents the principle and physical nature of laser ablation with a brief search of experiments performed so far for similar purposes. Based on this search we determine conclusions about the influence of buffer gasses and pressure on the detection used gasses. In the second part of the work, the controlled experiment is presented, which consisted of the detection of spectral lines of fluorine and potassium, see chapter 5.6 and molecular transitions of calcium fluoride, see chapter 5.10. In a controlled experiment, we established two assumptions. The first assumption is the influence of the inert gas atmosphere, which should significantly improve the detection of fluorine and potassium compared to the air atmosphere. We confirmed this finding only for the argon atmosphere. In contrast, in the helium atmosphere, the detection of none of the elements improved. The second assumption is the effect of reducing the ambient pressure, which in combination with an inert gas should allow the detection of fluorine even at low concentrations in the sample. We consider the measured glass disk in chapter 5.7 to be such a sample. This assumption is not confirmed, as the increased intensity of the fluorine spectral line does not manifest itself in any way when the pressure in the vacuum chamber decreases. Finally, in chapter 7 from the results of individual parts of the experiment, the most suitable conditions for the future detection of the measured substances were proposed: fluorine, potassium and calcium fluoride molecules.
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Design of a spectrometer accessory for absolute reflectance measurements
Šustek, Štěpán ; Antoš, Martin (referee) ; Klus, Jakub (advisor)
This paper describes the design and the design solution of an extension for measurement of an absolute reflectance using Perkin Elmer Lambda 45. This paper is divided into three parts. The first part deals with the basic theory of optics, knowledge of which is necessary for the proper function of the optical components used in the design. The second part provides an overview of configurations used in the practice to measure both the relative and the absolute reflectance. The last section includes the final design solution of the extension.
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Design of the telescope spectrograph for distant object analysis
Drobil, Tomáš ; Pořízka, Pavel (referee) ; Novotný, Jan (advisor)
Meteor spectra obtained from orbit include many spectral lines in the ultraviolet region, which is mostly absorbed by the atmosphere and thus cannot be observed from ground stations. This bachelor thesis focuses on the design of a spectrograph, placed in a 2U CubeSat, suitable for meteor observation and its spectral analysis in the range from the ultraviolet to near-infrared region. The design includes choice of a suitable camera. Based on the required parameters, several designs have been created, and the process is summarized in the last chapter. The research study of telescopes combined with spectrometers used for meteor observations is also included.
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A new generation of electronic cigarettes
Kodad, Daniel ; Bělka, Miloslav (referee) ; Lízal, František (advisor)
The subject of the bachelor thesis Electronic cigarettes of the new generation is the research and comparison of two electronic cigarettes which use heated tobacco systems with regards to emitted particles. The subject of the experiments was the electronic cigarette I quit ordinary smoking (IQOS) and electronic cigarette GLO. For the purposes of this work an experimental track was designed in the Aerosol Research Laboratory at BUT FME where the emitted particles from electronic cigarettes mentioned above were measured using instruments Aerosol Particle Sizer 3321 and TSI SMPS 3936.
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