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Remediation of former In-Situ uranium mining region.
Kříž, Jakub ; Kalous, Jaroslav (referee) ; Jícha, Jaroslav (advisor)
Remediation process of region, formally exploited for chemical leaching of uranium, is based on pumping water contaminated mostly by residuals of sulfuric acid from the relevant geological horizons. The contaminated water is then treated in a chemical plant. In the treatment process evaporators play the key role. Presently operating evaporators – three units – are of falling film type. Heating service is provided by compressed vapor that is generated by evaporators. For driving the compressors and associated circulating pumps of each unit electric power of 3,4 MW is required. In the evaporators treated solution is distributed into individual tubes by nozzles of cyclone type that are mounted at the top end of tubes. In the evaporators feed solution contains calcium sulfide of low concentration. Once the calcium sulfide concentration in the evaporating process reaches the state of saturation, even locally, fouling is initiated. Thus the solids start to grow on the inner surface of the tube wall and the nozzle’s openings become restricted. The evaporator performance – evaporating rate – gradually declines and when it reaches the bottom limit the evaporator has to be shut down. This is followed by carrying out the cleaning procedure. At the time when the evaporators started operating (1996) the period between shut downs lasted around a half a year. However, gradually, this period has become substantially shorter – presently it may even last one week only. The thesis proposes two ways of approaching the present hardly acceptable state. First, replacement of distributing nozzles by a set of properly perforated sieve trays secures the uniform distribution of solution into each individual tube. Second, evaporators’ duty will be taken over by newly build multi-flash concentrator that will substitute the presently operating evaporators. Configuration of this new equipment is derived from widely used multi-flash distillation of sea water. Heat required by the concentrator’s end heaters is drawn from a gas turbine exhaust gas. Steam provided by Heat Recovery Steam Generator is supplied to the condensing heat exchangers installed on the evaporator’s feed stream. Generator coupled to the gas turbine, fueled by natural gas, provides the electric power of 30 MW for export.
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Design of linear external excitation drive with oscillative motion
Gärtner, Jan ; Kalous, Jaroslav (referee) ; Singule, Vladislav (advisor)
This thesis deals with design of linear external excitation drive with oscillative motion. In the first part of the work is shown describe types of linear motors. Further is a part of analysis of concrete linear drives from patents database. In the next part of this work is straight design of linear external excitation drive with oscillative motion. The conception in-clude geometric model created with software Solidworks, calculation of forces with software Ansys and dynamic models of mechanical and electrical part of drive with software Mat-lab/Simulink. And is a mentions possibility of controls of this drive too.
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Methods for Analysis of Switched Circuits
Kovář, Jan ; Ondráček, Oldřich (referee) ; Kalous, Jaroslav (referee) ; Kolka, Zdeněk (advisor)
The dissertation deals with simulations of the DC-DC converters in their basic configurations (Buck, Boost, Buck-boost, Cuk, SEPIC). In the first part of the thesis derivation of transfer functions Line-to-Output (LTO) and Control-To-Output (CTO) can be found. These symbolic responses are derived for three types of basic converters (Buck, Boost, Buck-boost) using well-known average model [1]. Derived expressions are very complicated. For reduction of these expressions symbolic approximation method was used, however the generality is lost. The average model was used to for decreasing the computational effort of analysis of DC-DC converters in the time domain. For these simulations VHDL-AMS language was used. The main topic of the thesis is harmonic balance method, which was adapted to DC-DC converters. Because conditions and assumptions for LTO and CTO functions are very different, harmonic balance method was derived into two variants. For obtaining of LTO response, duty cycle of switching signal can be considered as constant in time. Spectrum of this signal is simple as follows from well-known sinc function. For obtaining of CTO response PWM modulation must be used. Compared to sinc function spectrum of PWM modulation is richer (contains more combination frequencies). Many types of PWM modulation is described in [31]. For simulation PWM modulation with uniform sampling in two variants (single and double edge) was used. Non-ideal switching of PWM switch was modeled by PWM pulse with defined slew rate. Last section deals with comparison of all derived functions (LTO, CTO, modulation type, defined slew rate) with well-known averaged model.
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Level and Efficiency of External Controls of Schools in Liberec Region (Focused on Founders' Competences and Mutual Cooperation During the Inspection)
Majerová, Jana ; Kalous, Jaroslav (advisor) ; Trojan, Václav (referee)
My thesis analyzes and evaluates the status and functioning of the education system in the Czech Republic. Furthermore, it analyzes the causes and consequences of influence of each factor on its quality. The found knowledge is summarized in the proposal of the new external school evaluation. Conslusions are based on the results of inquiry of directors, founders and employees of Czech School Inspection of Liberec region, based on the results of the national project Road to Quality Improvement realized in the Czech Republic, as well as the conclusions are based on results of international teams interested in implementation of evalution of school systems, for example Organization for Economic Cooperation Development (OECD), McKinsey & Company and Standing Conference of Central and General Inspectorates of Education (SICI). The aim of this thesis it to find the scale of competences and responsibility of each subject in educational politics. It is focused on qualification of founders and drawing of consequences coming from all indentified aspects. Not only evaluators' assistance and support to schools, but as well the mutual coherence and cooperation of all participating objects are very important parts of the process improving the quality of schools. The emphasis is laid on the cooperation of the...
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(Historical) development of the school management and its influence on the development of the education system in Kralovice
Holopírková, Petra ; Kalous, Jaroslav (advisor) ; Kitzberger, Jindřich (referee)
The Master's thesis deals with the history of education system in the Czech Republic and with the school management as closely related to the issue. The main focus is put on the historical development of the education system and its management in the town of Kralovice, West Bohemia. The aim of the thesis is therefore to demonstrate the gradual development and changes of the system in connection with the development of the school management within the mentioned territory. In particular, the most significant reforms and events affecting the education system are analysed in the study. The comprehensive view on the general development of the system and its management produced by the thesis can be beneficial for the pedagogical and administrative employees of every management level as well as for the local teachers, students and inhabitants of Kralovice.
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Analysis of the secondary schools optimization project in the town of Varnsdorf
Hodničák, Jan ; Kalous, Jaroslav (advisor) ; Kitzberger, Jindřich (referee)
The subject of the thesis is to analyze the optimization of secondary schools in Varnsdorf from procedures of the preparation, negotiations and approval process, to its realization. There search is based on data obtained through two of qualitative research methods: Participatory observation Analysis of documents - artifacts The thesis conclusion is based on triangulation, the penetration of various research methods, and contains, among others, recommendations for the Ministry of Education, Department of Regional Education Offices, regional councilors, and management of schools that prepare optimization projects. Particular attention is given to the impact of the optimization on the College and Secondary School in Varnsdorf.
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