|
|
Proposal of ultrasonic trap
Bartoň, Petr ; Pavlů, Jiří (advisor) ; Vyšinka, Marek (referee)
Light scattering by dust grains is a complex problem when the size of the grain is about the wavelength of incident light. The Mie theory is often used to characterize such situtation, however, most of the materials lacks knowledge of neccessary material constants. Moreover, solution of Mie equations for general shapes is difficult and partly not known. Objective of this work is development of apparatus for light scattering measurements on small (micrometer ranged) ar- bitrary shaped dust grains levitating in the ultrasonic field. Trap parameters are obtained by survey of literature and by numeric simulations leading to design of reliable ultrasonic levitator including optical system. The results enable manu- facturing and completion of such apparatus. Eventually, this work can serve as guide "how to design ultrasonic levitator".
|
|
|
Automation of dust charging experiment
Pechal, Radim ; Pavlů, Jiří (advisor) ; Žilavý, Peter (referee)
Title: Automation of dust charging experiment Author: Radim Pechal Department: Department of Surface and Plasma Science Supervisor: RNDr. Jiří Pavlů, PhD. Supervisor's e-mail address: Jiri.Pavlu@mff.cuni.cz Abstract: Since the dust grains are expected to cause problems during operation of tokamaks, there is a developing research of these devices which raises interest in dust grain charging processes research as well. Clarification of the dust grain charging processes may help with their solutions. This thesis deals with an issue of designing a part of a new experimental setup for dust grain research built at the Department of Surface and Plasma Science, Charles University in Prague. The base of this experimental setup is original linear quadrupole trap enabling dust grain trapping and its charging by electron, ion, and UV beams. In the thesis, a method of stabilization of one part of grain oscillation frequency detection is described. The thesis is focused on a development of a control unit and high voltage power supply for an image intensifier. To measure charging processes tungsten dust grains were used. This material will be probably used in construction of ITER tomakak. Electron equilibrium characteristics and other parameters were measured. Two samples of tungsten dust grains were used for...
|
|
|
Ionization methods of vacuum measurement
Pračko, Milan ; Gronych, Tomáš (advisor) ; Pavlů, Jiří (referee)
The Diploma thesis concerns with problems of measurement pressure of vacuum systems, with pressure lower than 10-6 Pa. Although most of the basic constructions of vacuum gauge for these levels of pressure was developed in the beginning of 1960s, the new constructions and modifications are still appearing. Ionization vacuum gauge 3BG (Bent Belt-Beam gauge) is one of them. Predisposition of 3BG for measurement of pressure lower than 10-6 Pa is verified by means of experimental verifying of characteristics of the brand new construction of vacuum gauge 3BG and by theoretical description of behaviour of the electrons in geometry 3BG, using computer simulation. Experimental specification of the most favourable parameters for operation of vacuum gauge 3BG is used for reaching maximal sensitivity with the cathode load at the lowest possible level. Powered by TCPDF (www.tcpdf.org)
|
|
|
Dust-UV interaction
Nouzák, Libor ; Pavlů, Jiří (advisor) ; Žilavý, Peter (referee)
Title: Dust - UV interaction Author: Libor Nouzak Department: Department of Surface and Plasma Science Supervisor: RNDr. Jiri Pavlu, Ph.D. Supervisor's e-mail address: jiri.pavlu@mff.cuni.cz Abstract: Micrometer objects (dust grains) are an integral part of the universe. As other objects in the plasma, these dust grains charge to potencial close to the potencial of the plasmas (in this case, interplanetary plasma). In the universe, the photoelectric charging dust grain dominantes all other charging processes. In general, the resulting charge of dust grain is given by a balance of all processes, which haven't been mostly jet theoretically described. In our laboratory, we are simulating space conditions and measure resulting charge and his changes on a single separated dust grain. This work is partly focused to UV source application and to finishing its electronics, and partly on test measurements and model calculations, connected with newly built experiment (e.g., to estimate effects of backgound currents, surfaces, and the geometry of the dust trap electrodes). The work is finished by the first measurements of glass grain charge under electron bombardment with provisional detection optics. Obtained results are compared with previous measurements on the same type of dust grains. Key words: dust, dusty plasma,...
|
|
|
Education of adults: approach of Polish andragogues
Pavlů, Jiří ; Beneš, Milan (advisor) ; Mužík, Jaroslav (referee) ; Palán, Zdeněk (referee)
The dissertation work called Education of Adults: Approach of Polish Andragogues, presents the problems of development of the adults education. Those are shown on the example of a country bordering on the Czech Republic - Poland. The work focuses our attention to presentation of theoretical knowledge from the sphere of the education of adults during historical events in 19th & 21th century. By means of the interpretation of views and ideas of education of adults given by pioneers of Polish andragogy, the work makes meeting a number of big names in this field possible. It is a rich and valuable source of information and their influence on the formation and development of the basis of andragogy. Also their participation in establishing and governing public education institutions, theoretical and scientific activities, building traditions have continued up to the present. A part of the work are supplements showing a clearly arranged system of education in Poland. Here we can also find university degrees, annotations of chosen periodicals, a complete list of names of edited titles (1994 - 2006) of the edition Library of Education of Adults. Association of Polish Public Education Workers and Association of Polish Specialists in Further Education can be found here as well. The benefits of the dissertation work...
|
|
| |
|
| |
|
|
People management, organizational culture and corporate changes (methodological perspective)
Franek, Marian ; Fiala, Bohumír (referee) ; Pavlů, Jiří (advisor)
The work "People management, organization cul ture and corporate changes (methodological perspective)" focuses on process of change management in a company and its relation with employees. lts target is to show change management as a process which touches not only other operations in the company but also people - employees who often feel the effects of the changes the most. This work's results are mainly to serve as a material for making decisions about what attitude is the best to choose for managing changes in reference to employees. Need for precise and systematic preparation before making changes is essential here. There is a methodology of usable research of change preparation and realization described here.
|
|
|
Analyse of thermal phenomena using thermal network
Pavlů, Jiří ; Sikora, Michal (referee) ; Vlach, Radek (advisor)
The aim of this work is to create an algorithm for solving steady-state thermal processes, algorithms for dealing with the transition state of thermal processes and the algorithm for solving ventilation networks. At the same time, the resulting application were expected to meet the conditions arising from the use as teaching aid.
|
|
| |
guest ::
