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Testing of Cutting Tools for Multi-Axis Machining at Machining Centres
Dvořáček, Jan ; Mrkvica, Ivan (referee) ; Janáč, Alexander (referee) ; Píška, Miroslav (advisor)
The thesis is focused on testing of the cutting tools for machining on five axis machine tools and possibility of implementation of designed experiments in this area. The theoretical section focuses attention on analysis of specific features during five axis machining, including chip cross section and particularity of tool testing under high speed cutting conditions with consideration of dynamic stability of cutting tools. In the thesis force loading of the tool is discussed as well as its measurement process, considering force development caused by tool wear and data analysis. Description of designed experiment and its application to the area of tool testing is included as well. All theoretical predictions are followed by experimental verifying by extensive number of experimental tests, including evaluation of cutting tool condition, influence of hard coatings on cutting power of the tools, etc. For each of testing conditions are designed specific methods of processing of gathered data as well as evaluation of power of the cutting tools. Gathered data were processed by means of statistical evaluation and by statistical methods of designed experiments. The thesis contains also the extensive number of records and analysis, documented by means of light microscopy as well as electron microscopy.
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Multimedia player of non-compressed audio data and images
Sekanina, Viktor ; Šebesta, Jiří (referee) ; Frýza, Tomáš (advisor)
The work deals with hardware and software design of standalone audio player for uncompressed format. Designing device will ensure the connection and operation of the hard drive, browse the directory and files, display bitmap images and play audio records. Next parts of player are also a graphic equalizer and audio power amplifiers for speakers or headphones. A certain complexity of the system is given a relatively high bitrate of uncompressed audio and the need to continuously control of the periphery.
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Analysis of thermal power plants environmental impacts using radioanalytical methods
Král, Dušan ; Ing. Ondřej Huml, Ph.D., KJR FJFI ČVUT v Praze (referee) ; Katovský, Karel (advisor)
Operation of classical power sources, like coal fueled thermal power plants, causes more or less strong impact on surrounded environment. Beside to the generally discussed CO2 emissions, there are CO, SOx, NOx too; and also fly ash emissions containing various trace elements depending on coal quality. Heavy trace elements carried by fly ash generate locally distributed fallout and contaminate soil in the power plant neighborhood for many years. These elements may be detected in soil samples as well as in biomass. Objectives of this work are to find and quantify trace elements in soil samples near Oslavany hard coal fueled thermal plant, which was in operation from 1913 to 1993. Power plant did not use any advanced fly ash filters. Hard coal was used as a fuel for power plant and it was mined locally in Rosice-Oslavany coal district in very deep mines (up to 1428 m). Coal contained a lot of trace elements. A mine as well as power plant is for more than 20 year closed, but trace elements can be still find in the environment. Main goal is to find these elements using activation analysis and gamma-ray spectrometry methodology. We have assembled thirty six soil samples in square lattice drawn around Oslavany power plant brownfield. On behalf of cooperation with colleagues from the Czech Technical University in Prague and their Open-Access project, we irradiated samples in three vertical channels of VR-1 research nuclear reactor. Irradiated samples were transported to gamma spectroscopy & activation analysis laboratory and measured by HPGe detector. Gamma spectra were analyzed and some trace elements identified. We have determine relative and absolute concentration of found elements. We observe and determine activity and weight of As, U, Ba, La, Eu, Mn, K, V, Mg and Na only. Results show a real suspicion for increase of trace elements in soil samples of hard coal power plant surroundings.
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DC/DC converters for industrial power supplies
Chudý, Andrej ; Cipín, Radoslav (referee) ; Procházka, Petr (advisor)
This diploma thesis deals with design and comparison of selected DC/DC converters, where the better of them is practically realized. The first part of the diploma thesis is focused on the general analysis of DC/DC power converters. The following part is theoretical analysis focused on the first selected topology – step-up converter. The second analysed topology is forward converter with full bridge on the primary side. The theoretical analysis also includes a description of synchronous rectifier, the differences between hard and soft switching, and the types of secondary rectifiers. Another part specializes in the detailed calculation of main components of selected converters and their subsequent power dimensioning. Both designed topologies are compared according to the required aspects. The selected better topology is supplemented by the design of control circuits and an auxiliary power supply. Practical realization of converter and commissioning follows. The diploma thesis ends with verification measurements on the realized converter and their subsequent analysis.
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Machining of hard-to-machine materials
Pátek, Vojtěch ; Sliwková, Petra (referee) ; Píška, Miroslav (advisor)
This bachelor thesis is focused on the issues of machining of hard-to-machine materials; specifically steels for power and chemical industries. The theoretical part of the work characterizes various steel types. The practical part deals with the selection process of the best tools for milling of martensitic steels.
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The War on Terror and the War of Terror: Revealing the post-transformation separatism Kremlin, Radical Salafism and Post-Soviet Dagestan on a Road from the Peace to the Violence
Baranec, Tomáš ; Horák, Slavomír (advisor) ; Aslan, Emil (referee)
After 1999 the situation in then relatively stable Dagestan started to deteriorate swiftly. However, unlike in the cases of previous separatist movements which sprung up in some parts of the Russian Federation after the demise of the USSS, Dagestani separatists did not officially gather under the flags of nation but under the flags of Islam. Soon, Dagestan entered a period of instability and violence which turned into a vicious circle of bloodshed. In a short period of time, Dagestan radically turned from stability to large scale violence, which makes it necessary for us to understand the factors responsible for the current situation. The following thesis analyses the development of Dagestan after the collapse of the USSR, from the stable period of the 90s till these days, which are characterized by omnipresent violence. Employing the theoretical knowledge collected by other scholars and analyzing similar separatist movements in other parts of the post-socialist world, taking into account the specifics the North Caucasus region, this study attempts to identify the factors (grassroots) which caused the rise of Dagestani insurgence. In comparison with the Chechen separatism of the early 90s, it uncovers the roots and the real face of the "new wave" of insurgency which flooded Dagestan and started to...
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DC/DC converters for industrial power supplies
Chudý, Andrej ; Cipín, Radoslav (referee) ; Procházka, Petr (advisor)
This diploma thesis deals with design and comparison of selected DC/DC converters, where the better of them is practically realized. The first part of the diploma thesis is focused on the general analysis of DC/DC power converters. The following part is theoretical analysis focused on the first selected topology – step-up converter. The second analysed topology is forward converter with full bridge on the primary side. The theoretical analysis also includes a description of synchronous rectifier, the differences between hard and soft switching, and the types of secondary rectifiers. Another part specializes in the detailed calculation of main components of selected converters and their subsequent power dimensioning. Both designed topologies are compared according to the required aspects. The selected better topology is supplemented by the design of control circuits and an auxiliary power supply. Practical realization of converter and commissioning follows. The diploma thesis ends with verification measurements on the realized converter and their subsequent analysis.
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The power of small states: A case study of Georgia (2004-2012)
Andrš, Vojtěch ; Aslan, Emil (advisor) ; Horák, Slavomír (referee)
This study focuses on use of foreign-policy power by Georgia on USA, EU member states and Russia during 2004-2012. In this period, Georgia wanted to enter into alliance with USA and EU states and gain access to Euro-Atlantic organizations, European Union and NATO. At the same time, Georgia wanted to reduce Russian influence on Georgian soil. After a few months of the new Georgian regime it was clear that the relation with its big neighbor will be difficult, mainly because of the two separatist republics on Georgian-Russian border, Abkhazia and South Ossetia. The aim of this study is to determine categories of power that Georgia used to achieve its goals. The study uses concepts of small state and power in international relations. Besides, it uses Nye's concept of soft and hard power. For influencing Western states Georgia chose the combination of soft and hard power. Soft power of Georgia has been mainly based on presentation of attractive values - pro-Western thinking a democracy - which should have attracted Western support. To a lower extent, foreign policy and culture were also used as sources of soft power. Georgia's hard power consisted of security importance and economic and political value of the country. In case of Russia, Georgia used only tools of hard power which included harsh rhetoric...
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