|
|
Optical characterization of thin oxide layers
Statelov, Martin ; Franc, Jan (advisor) ; Moravec, Pavel (referee)
Performance of CdZnTe-based detectors is highly related to the surface quality. Mechanical polishing, chemical etching and passivation are routinely employed for this purpose. The dynamics and properties of CdZnTe surface oxide layers, created by etching-only and passivation by KOH and NH4F/H2O2 solutions, were studied by optical ellipsometry. Effective medium approximation model was used to evaluate ellipsometric spectra. Thickness and formation rate of the surface oxide layers differed in each of the passivation method. Leakage currents were measured simultaneously and were compared with the surface oxide layer properties. NH4F/H2O2 passivation showed to be method with most desirable properties of the surface oxide layer; thick oxide layer and low leakage currents.
|
|
|
Electrooptic Pockels effect in X-ray radiation detectors
Rejhon, Martin ; Franc, Jan (advisor) ; Moravec, Pavel (referee)
In this work, we have added a temperature controller to an apparatus for measuring Pockels effect, which comprises of an integrated circuit and a Peltier element. Then the course of the electric field was measured in the sample of high resistance CdTe, a suitable detector on the high-energy radiation, depending on the voltage and temperature of the sample. Also the charge distribution in the sample was determined depending on time after the voltage and sample's temperature were reached. Finally, the activation energies of deep levels were determined, which are responsible for the polarization. Powered by TCPDF (www.tcpdf.org)
|
|
| |
|
| |
|
|
Generation of NPS for Exposure Experiments from Copper Acetylacetone.
Moravec, Pavel ; Schwarz, Jaroslav ; Vodička, Petr ; Kupčík, Jaroslav ; Švehla, Jaroslav
Particles containing copper are emitted from smelters, iron foundries, power stations, and municipal incinerators (WHO, 1998) and also from brake linings during breaking, Kukutschová et al. (2011). Nanoparticles (NPs) of copper are ingredients in polymers, inks, and bioactive coatings inhibiting the growth of microorganisms, Cioffi at al. (2005), and CuO NPs has been used in antimicrobial textiles, Gabbay and Borkow (2006), therefore they can be easily inhaled. Even though CuO NPs were found highly toxic, Karlsson et al. (2008), in vivo studies of their toxicity are still rather rare. In this work we tested a method of long lasting nanoparticle generation from copper\nacetylacetonate (CuAA) for use in follow up exposure experiments with laboratory animals. The exposure chamber for inhalation experiments was constructed in the\nInstitute of Analytical Chemistry AS CR (Večeřa et al., 2011) and some methods of NPs generation for these experiments were already tested in our laboratory (Moravec et al., 2015, Moravec et al., 2016).
Fulltext: content.csg -  PDF
Plný tet: SKMBT_C22016102412242 - PDF
|
|
|
Multifunctional house
Moravec, Pavel ; Javůrek, Tomáš (referee) ; Brukner, Bohuslav (advisor)
Specified bachelor thesis deals with an insulated newly built family house for four to five-member family with added polyfunctionally in the form of project office. Proposed construction is situated in the developable area of peripheral town part of Pelhřimov, southeast part of the town on the land number 2050/174. The proposed new building facility of a family house is a two-storey building consisting two rectangles inset into each other and with a double garage. The object is set into the sloping terrain so that the main entrance to the family house is in the level of the second aboveground floor where there is an entrance hall with utility room, a garage and relaxation, quiet and night zone located. From the level of the second aboveground floor it is possible to descend into the ground of the first aboveground. The ground floor serves as a space of residential area and daily and active space. In the level of the first aboveground floor there is the multifunctional part (project office) situated. It has separate entrance from the level of the first aboveground floor. The object is based on foundation walls and the spreading concrete slab on which the structural system walled of ceramic blocks will be based. The circuit construction will be complemented by contact insulation system ETIC made of breathable grey polystyrene. The ceilings are ferroconcrete and monolithic. There is a single-flat roofing with river-washed stones. The part of the thesis is the assessment of the object from the viewpoint of the thermal properties and processing of the solutions to fire safety construction.
|
|
|
Lead-acid baterry charger with automatic cycle
Moravec, Pavel ; Friedl, Martin (referee) ; Steinbauer, Miloslav (advisor)
The lead-acid batteries are still important and very often used type of battery even in 21st century. This project is focused on development of charger, which provides fast, but save charging of batteries with respect to maximum life time and reliability. The developed system uses constant current charging and constant voltage charging methods. It's specialized in charging batteries with liquid or gel electrolyte and traction types of batteries, which works with 12 V value of voltage. It's able to charge safely the deeply discharged batteries and when battery is unpluged for a long time, it can keep its capacity at maximum level too. The charger can choose optimal charging process according to the discharged level of battery. Each charging phase is interpreted by light signals and the achievable charging current is 20 A.
|
|
|
Design of switching laboratory source
Moravec, Pavel ; Klein, Richard (referee) ; Steinbauer, Miloslav (advisor)
In present days there is no scientific laboratory without quality, adjustable and powerful source of voltage and current. Therefore this thesis is focused on creating such power source, which can provide voltage and current high enough for most of experiments or for development electrical devices or parts, which are not connected to power grid. This power source is able to provide symmetric voltage 30 V and current 6 A high in each branch. It is possible to control this power source remotely thanks for USB interface, which is standard equipment of majority of modern devices in these days. LCD display is part of this source, which shows the user set and real parameters at the output as well.
|
|
|
Long Lasting ZnO Nanoparticle Synthesis for Potential Use in Inhalation Experiments
Moravec, Pavel ; Kupčík, Jaroslav
In this work we tested the long term generation of ZnO-NPs for potential use in exposure experiments with laboratory animals. These experiments require the generation of NPs in the gas phase with appropriate number concentration (Nt>1 107 #/cm3) and geometric mean diameter (GMD<50 nm) in duration of several weeks. Several methods of gas phase ZnO-NPs synthesis using metalorganic precursors, such as zinc acetylacetonate, zinc tetramethylheptane dionate or diethylzinc were reported in the literature. However, NPs prepared from metalorganic precursor are usually more or less contaminated by elemental (EC) or organic (OC) carbon. Therefore we used metallic zinc as a precursor in this study.
Fulltext: content.csg - PDF
Plný tet: SKMBT_C22015102910283 - PDF
|
|
|
Possibilities of nature and countryside protection in the Czech Republic and in Europe
MORAVEC, Pavel
The Bachelor thesis addresses possibilities of nature and countryside protection in Europe and the Czech Republic. At first, it describes and characterizes the Czech Republic including nature and countryside condition. Furthermore it presents historical development(evolution) of nature and countryside protection and processes general and special legal tools. It mentions the state program and the change of nature and countryside protection legislative after the Czech Republic entred the EU. It deals with European Union´s strategy in biodiversity area. In the last part it describes the most important conventions and cooperation on nature and countryside protection which the Czech Republic participated in.
|
guest ::
RSS feed.