National Repository of Grey Literature 27 records found  previous11 - 20next  jump to record: Search took 0.00 seconds. 
Possibilities of elimination of electrostatic charge generation in the belt conveyor drive
Pavluš, Ondřej ; Mach, Martin (referee) ; Veselka, František (advisor)
The purpose of revision of electrical devices is to assess the device in regard to its safety. The main goal of this bachelor thesis is a revision of an electrical conveyor belt engine. We focus on safety from injury caused by electric current due to malfunction and methods for detection and prevention of electrostatic charge buildup. We conducted an inspection and prepared the required norms and measurements. After a careful analysis of results we determined, whether or not the device meets the safety requirements specified by the relevant industry norms. Based on the insights from the inspection, we took necessary precautions with regard to static electricity buildup.
Influence of Change in Frequency of the Supply Current to the Operational Parameters of the Discharge Light Sources
Kuptsov, Alexander ; Škoda, Jan (referee) ; Krbal, Michal (advisor)
The master’s thesis is devoted to exploiting of gas-discharge lamps and their dependence on frequency of the supply current. The first part describes the theory of discharge, its types and properties, terms of its origin, and ways of its exploitation. The second part concerns electrical ballast systems of gas discharge light sources, inductive (reactive) and electronic ballasts, principles of their functioning, advantages and disadvantages, and the comparison of their properties. The following chapters deal with low-pressure and high-pressure gas-discharged lamps, compare their properties and describe exploitation of fluorescent lamps. Before conducting the experiment we have described the influence of frequency of the supply current on fluorescent tube lamps. Preparations for laboratory measuring have been also implemented. During the experiment the two types of lamps have been analyzed, the results of the research are summed up in the conclusion.
Diagnostics of plasma generated in the atmosphere simulating Mars
Fojtíková, Nikola ; RNDr. Martin Ferus, Ph.D., (referee) ; Kozáková, Zdenka (advisor)
The aim of the diploma thesis was the diagnostics of plasma generated in the atmosphere simulating conditions on Mars. This diploma thesis is focused on the simulation of Mars’ atmosphere at atmospheric pressure and normal laboratory temperature. Due to the similar conditions of Mars' atmosphere with Earth, this planet has been explored in the past as well as up to now. Mars' atmosphere is composed mostly of carbon dioxide, which makes up more than 90 % of Mars' atmosphere. A glow discharge generated in a special reactor at atmospheric pressure at a flow of pure CO2 was used to simulate the atmosphere of Mars. Part of the measurement was performed only in pure CO2 with changing current of 20, 25, 30, 35 and 40 mA. Part of the measurements was focused on the study of the effect of the addition of various gases, such as nitrogen, hydrogen and methane, at changes in their flow rates of 1, 2, 3, 4 and 5 sccm. The products formed in the special reactor were analysed using a mass spectrometer with proton ionization and with a flight time analyser. Optical emission spectrometry was used for plasma diagnostics and composition. Mainly simple aliphatic hydrocarbons, alcohols, aldehydes, and ketones were detected. With increasing flow rates of the individual gases, more complex aromatic compounds with higher molecular weights were formed. Corresponding mass and optical emission spectra were measured simultaneously.
Possibilities of clinical use single and tandem shock waves.
Zeman, Jan ; Beneš, Jiří (advisor) ; Kneppo, Peter (referee) ; Bolek, Lukáš (referee)
Shock waves have been used in medicine for more than 30 year. At the beginning was mainly use for lithotripsy, but today is also applied in other fields of medicine, such as orthopedics, rheumatology and others. Single shock wave is one shock that usually is repeated every 1-1.5 seconds. By contrast tandem shock waves are two shocks consecutively (ideal interval between shocks is from 8 to 15 microseconds), that are repeated. In this work we investigated the clinical use of single and tandem shock waves that are generated entirely new source. It is based on the principle of multichannel discharge. It was found that a single shock wave can destroy the union between bone and bone cement, this effect could be used in orthopedics. Single and tandem shock wave can damage the tumor in vivo, but the principle damage is different. Tandem shockwave is able to cause damage in a depth of acoustically homogeneous medium and enhances the effect of chemotherapy. It would therefore be possible to used single and tandem shock waves in oncology either alone, or their combination with other chemicals. Functional sample of clinically usable applicator of shock waves with a new source was made for these applications. Powered by TCPDF (www.tcpdf.org)
Temporally and spatially resolved diagnostics of an electric arc
Holcner, Oldřich ; Šimek, David (referee) ; Kloc, Petr (advisor)
This batchelor thesis "Temporally and spatially resolved diagnostics of an electric arc" deals with the investigation of plasma temperature in an arc formed by evaporation of copper wire. It is an optical method based on determination of temperature from intensity of spectral lines. In this batchelor thesis we explain how spectral lines are formed and how to determine the temperature. In the practical part we process discharge and show the time evolution of temperature at the measured points.
Effects of electrical discharges on the Mars´ atmosphere
Fojtíková, Nikola ; Horák, Jakub (referee) ; Kozáková, Zdenka (advisor)
The aim of this thesis was to study the effects of electric discharge on the atmosphere simu-lating conditions on Mars. This bachelor thesis is focused on simulation of Mars atmosphere at atmospheric pressure and normal laboratory temperature. Mars's atmosphere was more like Earth in the past. Mars is mostly composed of carbon dioxide, which accounts for more than 90% of Mars' atmosphere. To study the Mars atmosphere simulation, glow discharge generated in the reactor at atmospheric pressure was used at a CO2 flow (100 sccm) and dis-charge current of 20, 30 and 40 mA. A part of the measurements was focused on the influ-ence of hydrogen addition at different flow rates. The measurement time course with differ-ent measurement changes was also recorded. Reaction products were analysed using a pro-ton ion mass spectrometer and a flight time analyser. A high amount of aliphatic hydrocar-bons and their derivates, especially alcohols, was detected as well as several cyclic struc-tures. The main products identified in all experiments with a substantial concentration were molecules of ethen, ethane, ethanol, acetone, pentane, benzene and others.
Possibilities of elimination of electrostatic charge generation in the belt conveyor drive
Pavluš, Ondřej ; Mach, Martin (referee) ; Veselka, František (advisor)
The purpose of revision of electrical devices is to assess the device in regard to its safety. The main goal of this bachelor thesis is a revision of an electrical conveyor belt engine. We focus on safety from injury caused by electric current due to malfunction and methods for detection and prevention of electrostatic charge buildup. We conducted an inspection and prepared the required norms and measurements. After a careful analysis of results we determined, whether or not the device meets the safety requirements specified by the relevant industry norms. Based on the insights from the inspection, we took necessary precautions with regard to static electricity buildup.
Spectroscopic analysis of an electric arc
Hartman, Tadeáš ; Kloc, Petr (referee) ; Šimek, David (advisor)
The bachelor thesis deals with spectroscopic diagnostics of electric arcs. The first part explains the creation and properties of electric discharges, especially electric arcs. Methods for composition and temperature analysis of electric arcs are also given there. The next part deals with practical use of these methods for identification of elements contained in electrodes between which an arc discharge was happening, measurement of the arc temperature and also measurement of the temperature of the electrodes. In the last part, these methods are also used for the analysis of time progression of composition and temperature of an electric arc created on a contactor's contacts with the resistive load.
Generation of nanoparticles by electrical discharge in liquids
Čechová, Ludmila ; Horák, Jakub (referee) ; Kozáková, Zdenka (advisor)
This thesis focuses on the process of nanoparticle generation by electric discharge in liquids. The theoretical part is focused on generation of electric discharge in liquids, various methods of preparation of nanoparticles, including plasmachemical methods and methods of nanoparticle characterization. The experimental part deals with the preparation of silver nanoparticles. As a precursor for generation of nanoparticles by electric discharge, an aqueous solution of silver nitrate was used. The influence of experimental conditions, such as the influence of voltage polarity, influence of delivered power, effect of concentration, effect of added electrolyte and time course of nanoparticle formation were studied. All samples were analyzed by UV-VIS spectrometry. To confirm the presence of nanoparticles in the solution, one of the samples was analyzed by a scanning electron microscope with an energy dispersion spectrometer for elemental analysis. Plasma diagnostics was performed using optical emission spectroscopy.
Possibilities of clinical use single and tandem shock waves.
Zeman, Jan ; Beneš, Jiří (advisor) ; Kneppo, Peter (referee) ; Bolek, Lukáš (referee)
Shock waves have been used in medicine for more than 30 year. At the beginning was mainly use for lithotripsy, but today is also applied in other fields of medicine, such as orthopedics, rheumatology and others. Single shock wave is one shock that usually is repeated every 1-1.5 seconds. By contrast tandem shock waves are two shocks consecutively (ideal interval between shocks is from 8 to 15 microseconds), that are repeated. In this work we investigated the clinical use of single and tandem shock waves that are generated entirely new source. It is based on the principle of multichannel discharge. It was found that a single shock wave can destroy the union between bone and bone cement, this effect could be used in orthopedics. Single and tandem shock wave can damage the tumor in vivo, but the principle damage is different. Tandem shockwave is able to cause damage in a depth of acoustically homogeneous medium and enhances the effect of chemotherapy. It would therefore be possible to used single and tandem shock waves in oncology either alone, or their combination with other chemicals. Functional sample of clinically usable applicator of shock waves with a new source was made for these applications. Powered by TCPDF (www.tcpdf.org)

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