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Health effects of ionizing and non-ionizing radiation
Gottvald, Martin ; Neoral, Jiří (referee) ; Bača, Petr (advisor)
This diploma thesis deals with electromagnetic radiation in its frequency spectrum. It also divides radiation into ionizing and non-ionizing. The principle of its effects and possible health problems from radiation exposure are also described. Hygienic limits – the maximum allowable and reference values of non-ionizing radiation are analysed too. The thesis should prove that the things of everyday need do not threaten the lives of human beings and are in compliance with the regulation No. 1/2008 Sb. on Health Protection Against Non-Ionizing Radiation. Measurement of low-frequency part is carried out with the cooperation of The National Institute of Public Health. Measurement of high-frequency part was carried out in 3 flats. The aim of this measurement was to find out the change of power density with the moving in a flat and the influence of the barriers (in this case walls).
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Photovoltaic system for RAPS applications
Nevoral, Miroslav ; Bača, Petr (referee) ; Křivík, Petr (advisor)
The beginning of this work presents the basic principles of photovoltaic cells, their advantages and disadvantages. There is also an overview of photovoltaic systems. The next part takes a closer look on lead-acid accumulators followed by a practical part regarding the measurement of VA characteristics. The main goal of this work is to assemble an experimental PV system. It will consist of a PV module, an accumulator (consisting of two cells connected in series and producing an overall voltage of 5V) and of a variable load (assembled from nineteen resistors with resistance varying from tens to hundreds of Ohms). This system is connected to a computer that runs the control software which was created using the VEEPro 8.0 simulation environment. The measurements can be taken in two ways. Either the operator can select the load resistor combinations manually, or the operator only launches the measurement and the load is selected automatically by the software. This way we obtain an automatized workplace for measuring VA characteristics of photovoltaic panels.
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Economics and viability of photovoltaic power station
Mrázek, Dalibor ; Bača, Petr (referee) ; Křivík, Petr (advisor)
At the beginning of the submitted work, I dealt with the study of various types of photovoltaic panels, their diverse use, effectiveness, advantages of each type and description of climate in the Czech Republic. Depending on the number of sunny days and no claudy days, I was looking for the best areas photovoltaic power. On the basis of cooperation with the firm and Energ-servis and using their test center, I compare different types of panels, their performance in relation with the cost and method of purchase. From these data, six diverse installation, I tried to determine the best type of panel that is best for the South Moravian region in the cost / return on investment.
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Functional blocks for the development of autonomous photovoltaic system
Ovesný, Karel ; Křivík, Petr (referee) ; Bača, Petr (advisor)
The project considers realization system, which will allow us to test six different operation modes on lifetime accumulators. The system will link to computer, which will execute measurement current and tension and switch betwencharging and discharging modes. The measured values will record in someone time intervals in to computer memory. After someone time will analise these measured valuer and will provide optional operation mode.
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Catalysts for positive electrode of hydrogen-oxygen fuel cell
Kováč, Martin ; Bača, Petr (referee) ; Novák, Vítězslav (advisor)
Master's thesis deals with new methods of preparing catalytic materials for positive electrode of an oxygen-hydrogen fuel cell and the influence of potassium permanganate or doping agent molar mass change on theirs attributes. Further it studies the use of proper measuring methods designed to qualify theirs attributes and the presentation of achieved results. In particular methods of linear sweep and cyclic voltammetry and the processing of data using Koutecky-Levich and Tafel plot and wave log analysis. Values of half-wave and onset potential and kinetic coefficient have been measured and calculated.
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Investigation pressure effect on lead-acid accumulator lifetime for hybrid electric vehicles.
Kulhány, Andrej ; Bilko, Radek (referee) ; Bača, Petr (advisor)
The thesis is focused on remitting lead-acid segments of partial charge mode which simulates the conditions in HEV. The experimental cells were submitted to different pressures on the electrode system. The main aim of the thesis was to minimize the irreversible sulphating of the negative electrodes, which are in the PSoC regime limiting in the overall life of lead-acid accumulators. All cells were submitted to measurement of the negative electrode potentials, resistance of active materials, contact resistance of the grid – the active material and measurements of pressure changes during three PSoC cycles.
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Investigation causes of the premature capacity loss in accumulator for hybrid electric vehicles
Vystrčil, Marek ; Bilko, Radek (referee) ; Bača, Petr (advisor)
This thesis describes the results of two successive experiments. The first was focused on the influence of impurities in the active mass of negative electrode in PSoC (Partial State of Charge) mode, which simulates the conditions occurring in HEV (hybrid electric vehicle). In the second experiment, cells with the same additives were exposed to optimum downforce 4N/cm2, by which we wanted to prove the influence of pressure on life of VRLA (Valve Regulated Lead Acid) cells working in operating HEV conditions.
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Investigation of carbon effect in negative active mass on lead-acid accumulator for HEV.
Tonar, Karel ; Křivík, Petr (referee) ; Bača, Petr (advisor)
The lead-acid bateries for hybrid-electric vehicle (HEV) working under high-rate partial-state-of-charge (HRPSoC) conditions. The negative plates of lead-acid batteries have low charge acceptance. The cycle life of the batteries is dependent on the rate accumulation of PbSO4 on the negative plates. Addition of some carbon or graphite forms to the negative paste mix improves the charge efficieny and slows down sulfation of the negative plates. The master’s thesis wants to explain the contribution of electrochemically active carbon (EAC) additives to the mechanis of the electrochemical reaction of charge of the negative plates.
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Investigation of temperature change in lead-acid accumulator for HEV
Tošer, Pavel ; Křivík, Petr (referee) ; Bača, Petr (advisor)
The oldest and also most used type of secondary cells is lead-acid accumulator. Basic functional principle stayed same as in foundation time, only operation parameters are still improving (for example one of the most important is lifetime). Significant technical problem is temperature of lead-acid battery and her influence on functionality and running reactions. Master thesis is focused on this section, when is necessary to evaluate new pieces of knowledge in development. The work deals with description existing types of accumulators, further deals with theory of temperature balance and in the end by measured datas and theirs analyzing.
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Investigation size effect of negative active mass additive on service life lead-acid accumulator.
Mikoláš, Jiří ; Novák, Vítězslav (referee) ; Bača, Petr (advisor)
The task of research work is to study new mechanisms and to minimize disturbance of lead batteries for hybrid electric vehicles. Those arising under the PSoC (Partial State of Charge) and is linked to irreversible sulphation mainly negative electrodes. As one solution to prevent sulphation of the negative electrode appears to be the active ingredients in a negative matter. In the investigated electrodes is verified the influence of carbon, titanium dioxide and silica on the grain size of the order of nanometers.
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