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Photoelectric transport in high resistivity CdTe for gamma ray detectors
Dědič, Václav ; Šikula, Josef (referee) ; Franc, Jan (advisor)
CdTe semiconductor is a good material for the construction of X-ray and gamma ray detectors. Its physical properties are strongly influenced by an existence of deep levels in the forbidden band. This thesis deals with an influence of deep levels to the photoelectric transport in high resistivity CdTe. Experimental part of this thesis consits of measurement of slopes of Lux-Ampere characteristics of variously doped CdTe samples depended on voltage and energy of excitation. Gradients of measured guidelines of Lux-Ampere characteristics show strong dependency on an electric charge accumulated on deep levels. This thesis also contains numerical models of photoconductivity for various parameters of material.
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The Ancient Egypt Resources of the Coptic Religiosity: The Selected Subjects
Franc, Jaroslav ; Gebelt, Jiří (referee) ; Janák, Jiří (advisor)
The master thesis titled The Ancient Egypt Resources of the Coptic Religiosity: the Selected Subjects is in the hypothetic possibility focused on the continuity of the religious symbolism from Ancient Egypt times to the time of The Coptic Church. The paper is based on the personal experience from within The Coptic Church in Egypt as well as on the research in libraries and museums. The attention is drawn mainly to the theme of breastfeeding woman - Eset, Isis, the Virgin Mary.
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Photoelectric spectroscopy of deep electronic levels in high-resistance CdTe
Kubát, Jan ; Franc, Jan (advisor) ; Sopko, Bruno (referee)
CdTe is one of the most interesting X-ray and g-ray detectors' material. This work deals with influence of deep levels to photoelectric properties of CdTe. PICTS, Lux-Ampere and spectral dependences measurements at room temperature and low temperature 10K were performed on one undoped and several variously doped (Cl, Sn and Ge) samples and applied electrical fields up to 800V.cm-1. Experimental setups are introduced. Room temperature numerical solution of sample photoelectrical properties for typical midgap level using driftdiffusion and Poisson equation was performed and results are discussed. The experimentally observed slopes of Lux-ampere characteristics and energy shifts of the main photoconductivity peak with the applied voltage are explained based on a model of screening of electric field by charge accumulated on deep levels. Finally comparison with acquired experimental data is performed yielding estimates of maximum total concentration of deep levels in the samples.
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Effect of surface of semiconductor nanocrystals on their properties: investigation by laser spectroscopy
Preclíková, Jana ; Malý, Petr (advisor) ; Franc, Jan (referee)
The topic of the diploma thesis is chemical treatment of the surfaces of semiconductor nanocrystals CdS and CdSe in the form of thin nanocrystalline films prepared by chemical bath deposition. The evolution of photoluminescence and absorption spectra was investigated under treatment by water, toluene, butylamine, pyridine and hydrogen peroxide. The strongest changes were observed by samples soaked in water, pyridine and aqueous solution of pyridine. The observed effects were explained by partly dissolving of nanocrystals by water and affecting behaviour of photoexcited holes in the presence of the strong hole acceptor pyridine. The second part of this diploma thesis deals with photochromic properties of silver nanoparticles in a titanium oxide matrix. The photochromic behaviour of the samples was examined in detail. A phenomenological model of photochromic changes was suggested in analogy with the hole burning spectroscopy. In order to better understand the microscopic processes in this composite material other experiments were realized - e.g. samples were UV irradiated, or laser illuminated under lowered air pressure, pump & probe experiment. Under laser irradiation optical extinction of some nanoparticles was decreased. Simultaneously, changes of plasmon resonances of the rest of nanoparticels were...
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A set of row attached low energy houses for living in Vážany nad Litavou
Pfleger, Jaroslav ; Franc, Josef (referee) ; Hradil, Dušan (advisor)
Diploma´s thesis “ A set of row attached low energy houses for living in Vážany nad Litavou ” is elaborated in form of project documentation which includes all requirements of given standards. The object is placed on plat number 1746 in cadastral community Vážany nad Litavou. The character of the object is brick building. The building is covered gabled roof. It is two-floor house with no cellar. There is living room, kitchen, bedroom with it´s own sanitary facility and technical room in the ground floor. There are bedrooms with sanitary facilities in the second floor. The thesis is worked up as a complete implementation building plan.
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Methods of measuring bit rates
Franc, Jan ; Mišurec, Jiří (referee) ; Zeman, Václav (advisor)
Study and basic benchmarking methodology description of network connections based on the IP was the objective of bachelor work. I resulted above all from RFC standards, by which are directed most of Internet protocols. Particular procedures for testing are explained in RFC 2544. On the basis of parameters analysis, I suggested conception and gave shape to web application which allows identify referenced basic transfer parameters of Internet connection (downstream, upstream, latency, scattering of connection speed). Application doesn’t require no add-ons and modules on user side. It is built on server programming language PHP with usage of relational MySQL database, in which are stored data. Client scripting language JavaScript is also used. Application offers measuring of mentioned parameters both to visitors and to registered users. Matter of course is user registration; work with history of carried out measuring, sending private messages between registered users. Above whole application exists administrator account.
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