National Repository of Grey Literature 43 records found  previous11 - 20nextend  jump to record: Search took 0.01 seconds. 
Utilization of ANSYS Workbench program at power electrical engineering
Partl, Tomáš ; Aubrecht, Vladimír (referee) ; Kuchyňková, Hana (advisor)
In its first part this Master´s thesis describes creation of electronic database design in Raster Design 2009 program as an effective form of storage only for paper documentation. The second part of my thesis provides calculation of primary and secondary winding of current instrument transformer of over-current conduit through the winding and influence on other parts of transformer i.e. error of transformer or increasing magnetic induction core and others. The last third part is focusing on usage of ANSYS Workbench in power electrical engineering. The thesis shows specific example of warming of current instrument transformer (thermal analysis) and comparing the results with theoretical (calculated) values.
Utilization of infrared camera for temperature measurement of electrical machines
Líbal, Jan ; Aubrecht, Vladimír (referee) ; Kuchyňková, Hana (advisor)
The master‘s thesis deals with utilization of infrared camera for temperature measurement of electrical machines. The first part describes non-contact temperature measuring, the second part describes principle of sensors that evaluate quantity of incident infrared radiation. In the next part there is termovision camera SAT-HY 6800 presented and the instructional manual for SAT Report computer programme created. This computer programme is used for analyzing of termovision pictures from the SAT-HY 6800 termovison camera. The chapter 7 describes temperature measuring of one-phase asynchronous motor type J22TO484. The chapter 8 describes temperature measuring of semiconductor components of EC motor G6 series. Both of these motors are produced by ATAS elektromotory Náchod a.s. The last part of the thesis describes creation of animation of one-phase asynchronous motor type J22TO455. The animation was created in 3ds Max computer programme.
Study of arc root movement in a model of the LV quenching system
Fendrych, Martin ; Aubrecht, Vladimír (referee) ; Valenta, Jiří (advisor)
Thesis focuses on the basic characteristics of plasma, problems about origin of electrode spots and electrodynamics force acts on the electric arc. In the practical part was realized and produced model of a LV quenching system. Using optical diagnostics was received necessary data to analyze the movement of the electrode spots. The movements of the electrode spots were analyzed in terms of value RMS current passing through the electric arc, value of absolute pressure model in the LV quenching system and distance from each electrode.
Determination of the Temperature Field in a Real Circuit Breaker
Pěček, Dominik ; Aubrecht, Vladimír (referee) ; Kloc, Petr (advisor)
This master thesis deals with determination of temperature field in a real circuit breaker. This issue is solved by analysis of measured emission spectra at selected points of the circuit breaker. Spectral line ratios and Boltzmann plot are used for calculation of temperature. These methods are based on elemental analysis of plasma. The main result is finding significant changing of chemical composition of plasma beyond determination of temperature field.
USING MODERN NUMERIC METHODS IN DESIGN OF LOW VOLTAGE CIRCUIT BREAKERS
Dostál, Lukáš ; Hüttner, Ľudovít (referee) ; Petráček, Miloš (referee) ; Aubrecht, Vladimír (advisor)
The theses is focused on efficient use of numerical methods in development of low-voltage switching devices, namely to create a physically correct and reliable numerical model of the temperature field to find an application in the design of the current path of a device for various operating conditions. The creation of this numerical model requires not only correct inclusion of all modes of heat transfer - conduction, convection and radiation, but also correct solution of problematic transient resistance - both electrical and thermal in electrical contacts at different stages of usage. Therefore an essential part of the theses forms a thorough experimental analysis of the necessary material properties and dependencies which forms input data for the numerical model that is based on the finite volume method. The last part of the theses deals with debugging and verification of numerical model to correspond with experimentally obtained data. The result of the theses is the numerical model which is able to solve correctly both steady and various transient states of swiching devices.
Visualization of input parameters for radiation transfer in plasma
Kubovič, Tomáš ; Aubrecht, Vladimír (referee) ; Kloc, Petr (advisor)
This bachelors thesis focuses on simplification of the input parameters for electrical arc radiation transfer calculations. In the first part, we learn basics of transfer for thermal radiation and calculation of the absorption and emission coefficients. Next part is devoted to the design of absorption model and describes various parts of the model. It is followed by a graphical design of the interface which also displays various graphs. The next chapter explains the operating principle of the software application. The last chapter shows an example of the plot for computing domain.
Study of the effect of tissue conductivity on electroporation
Hemzal, M. ; Aubrecht, V.
This paper deals with two different dynamic models of electrical conductivity and a static model for electroporation. Those models were used to calculate electric field distribution in the tissue, the current and the volume of the tissue that will be subjected to electroporation. The results are than compared to the experimental model. Improved model can be used to better predict ablation zones.
Global trends in HIV/AIDS mortality
Aubrecht, Vratislav ; Kurtinová, Olga (advisor) ; Kučera, Tomáš (referee)
This thesis is focused on the development of HIV/AIDS mortality in the world starting from the year 1990 and the main goal is estimating the possible future development of the number of inhabitants of the world and defined regions and the influence of HIV/AIDS on the number of inhabitants up to the year 2065. The possible number of HIV/AIDS deaths and people, who were not born because of HIV and AIDS, is computed up to this year. In the theoretical part of the thesis, the most important institutions, which include fight against HIV and AIDS as a part of ther programme, are presented. Natural history of HIV infection and the successes in the research of HIV vaccine are described. In the analytical part, the demographic reproduction of the population of the world and selected regions between years 1950 and 2010 is described, followed by population projection of the world and regions up to year 2065 using the cohort component method. The projection is created in four variants. The first one eliminates the HIV/AIDS mortality. The second one is the constant variant, which conserve the level of HIV/AIDS mortality from the year 2010 up to the year 2065. Last two variants, higher and lower, consider changing levels of HIV/AIDS mortality at time. According to the results of this population projection,...
Development of the secondary sex ratio in India and China
Aubrecht, Vratislav ; Kurtinová, Olga (advisor) ; Fialová, Ludmila (referee)
Development of the secondary sex ratio in India and China Abstract The main objective of this thesis is to describe the population development and the development of the sex ratio at birth in India and China from 1950 to the present. In the majority of the populations of the world the sex ratio at birth (number of males born per 100 females) has usually values between 104- 106 male live births per 100 female live births, although determining exact borders varies depending on source. In some countries, the sex ratio at birth has risen to unnaturally high values in recent decades. This has happened in East and Southeast, South and West Asia or in Southeast Europe. In those countries, the son preference is deeply rooted. This is determined by many cultural, political, social and economic conditions. When two of the signs of gender discrimination are increasing sex ratio at birth and excessive female infant mortality, it brings a number of demographic consequences, which have further economic and social impact on society. No wonder many governments of the affected countries pay attention to this phenomenon, because those generated problems could affect and in some countries probably will affect society dozens years after sex ratio at birth returns to biologically normal values. Keywords: secondary sex ratio,...
USING MODERN NUMERIC METHODS IN DESIGN OF LOW VOLTAGE CIRCUIT BREAKERS
Dostál, Lukáš ; Hüttner, Ľudovít (referee) ; Petráček, Miloš (referee) ; Aubrecht, Vladimír (advisor)
The theses is focused on efficient use of numerical methods in development of low-voltage switching devices, namely to create a physically correct and reliable numerical model of the temperature field to find an application in the design of the current path of a device for various operating conditions. The creation of this numerical model requires not only correct inclusion of all modes of heat transfer - conduction, convection and radiation, but also correct solution of problematic transient resistance - both electrical and thermal in electrical contacts at different stages of usage. Therefore an essential part of the theses forms a thorough experimental analysis of the necessary material properties and dependencies which forms input data for the numerical model that is based on the finite volume method. The last part of the theses deals with debugging and verification of numerical model to correspond with experimentally obtained data. The result of the theses is the numerical model which is able to solve correctly both steady and various transient states of swiching devices.

National Repository of Grey Literature : 43 records found   previous11 - 20nextend  jump to record:
See also: similar author names
5 Aubrecht, Vladimír
4 Aubrecht, Vratislav
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