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Effects of cultural noise in natural magnetotelluric signals
Klanica, Radek ; Pek, Josef (advisor) ; Červ, Václav (referee)
Magnetotelluric method is an electromagnetic induction method which studies the dis- tribution of the electrical conductivity in the Earth by analyzing natural variations of the Earth's electromagnetic field of the external origin. A wide frequency range of the natural sources of the magnetotelluric field makes it possible to study the Earth's conductivity from near-surface structures down to depths of the upper mantle. Dependence on weak natural fields, however, causes the method to fail in case of data contaminated by electro- magnetic disturbances of cultural origin. This thesis summarizes basic principles of the statistical magnetotelluric data processing in the frequency domain, and shows the recent progress of the processing due to the application of robust statistical methods as well as due to employing reference data from remote stations. In some cases, the measurements are disturbed excessively, and even advanced statistics method fail in processing the data. In some of these cases a more thorough analysis of the noise field in terms of its directional and source characteristics may be useful. We present an example of simultaneous recor- dings of two magnetotelluric stations from the West Bohemian seismo-active region and show that the noise field is dominated by two types of strong electric...
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Human brain and its modeling
Zelenka, Pavel ; Koudelka, Vlastimil (referee) ; Raida, Zbyněk (advisor)
The project deals with the development of a computer model of human brain. The model is used in the simulation program CST STUDIO SUITE 2015 to show the distribution of electromagnetic waves. The outputs of simulations should help us with a better understanding of electromagnetic field behavior inside the brain. In real life, the model will be used for the verification of methods localizing source currents in the brain.
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Magnetostriction vibration power generator
Šumpelová, Jana ; Singule, Vladislav (referee) ; Hadaš, Zdeněk (advisor)
This thesis deals with the idea of energy harvesting from mechanical vibration. It describes the magnetostrictive principle as a possibility to obtain an electrical energy. It is about a generator made of a beam with Terfenol-D material and a coil. The model of this device is created in Matlab/Simulink and FEMM application. For various values of measured vibration, these methods are then compared. In FEMM, you can improve energy gain by modeling of various environmental conditions and with using of another materials (e.g. by adding of permanent magnets). The outcome of the this thesis expresses the ability to harvest the energy with designed magnetostrictive generator compared to the already created models of the piezoelectric and electromagnetic generator. Based on these results, it is possible to determine which generator is more suitable for particular application.
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Monitoring the impact of exposure to electromagnetic fields in yeast colonies
Hájková, Renata ; Vorlíček, Jaroslav (advisor) ; Cifra, Michal (referee)
Identifikační záznam: HÁJKOVÁ, Renata. Sledování vlivu expozice elektromagnetickým polem na kolonii kvasinek [Monitoring the impact of exposure to electromagnetic fields in yeast colonies]. Praha, 2011, rok vydání. 74s., 2. příl. Diplomová práce (Mgr.). Univerzita Karlova v Praze, 1. Lékařská fakulta, Fakulta elektrotechnická, Katedra elektromagnetického pole, ČVUT v Praze. Vedoucí závěrečné práce Vorlíček, Jaroslav, Ing. Abstract: Current development of mobile telecommunication device increases interest of public to the question of influence of electromagnetic field to the living organisms. Results of this work contribute to better knowledge of interaction between electromagnetic field and cell structures. Beginning of the thesis is review of morphology and physiology of the yeast cell that was used in this work as a tested organism. Second chapter describe the basic facts about electromagnetic fiend and wireless energy transfer. Goal of the practical part of this master thesis is describe influence of electromagnetic field on population of yeast during their proliferation. We constructed special box connected with wireless energy generator that was source of exactly defined electromagnetic field. Cells of Saccharomyces cerevisiae were diluted in fluid medium YPD and the proliferation of the culture was...
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The comparison of knowledge of electromagnetic field theory for laymen and experts within the civil emergency preparedness
VESELÁ, Barbora
The thesis "Comparison of knowledge of electromagnetic field theory of the laity and experts in the context of civil emergency preparedness" to put three goals: 1. The formation of the structure of an electromagnetic field for experts. 2. The reaching of the comparison of knowledge among experts and laymen. 3. Statistical processing of the results. The author has set the following hypotheses: H1. Theoretical distribution of knowledge in a sample of the general public will have a normal distribution . H2. Theoretical distribution of knowledge in a sample of professional community will not have a normal distribution. H3. The comparison of knowledge among the experts and the laymen will lead to an alternative hypothesis. The thesis was based on the knowledge of the theory curricular process. On the basis of this theory was made up not only the structure of the electromagnetic field, but also the questionnaire. An important step in this thesis was the creating a model structure of electromagnetic field . The structure was based on an analysis of the scientific system - the system of educational programs in the field of civil protection.The same structure was applied to the general public. An important step was to compare the knowledge of protect the population from experts and laymen. This issue has not been investigated in detail and it did not compare the knowledge of laymen and experts in the studied physics. The idea came from the possibility of extraordinarily events where respondents can meet with electromagnetic fields and will need the relevant theoretical knowledge. The aim was to the statistical evaluate of the applied questionnaires. There were applied nonparametric and parametric testing as the verification methods. The theoretical division of knowledge of experts is supposed Poisson distribution, on the contrary, the theoretical division of the general public should have a normal distribution. There was also compared the difference between knowledge of laymen and professionals. The using of the statistical methods have been received and confirmed the hypothesis and the thesis goals were fulfilled.
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Realization of the positioning device for mapping electromagnetic fields
Jozífek, Eduard ; Drexler, Petr (referee) ; Nešpor, Dušan (advisor)
This paper deals with the measurement of electromagnetic fields in reactive zone and proposing an automated workstation for its measurement. The sample is a periodic structure of the circular split resonators, which is due to the magnetic field generated from the supplied loop antenna is brought to resonance and itself becomes imaginary antenna. The measuring probe is placed on the cross-positioning table movement is controlled by two stepper motors.
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Chart of electromagnetic fields in GIS
Brachtl, Martin ; Bubník, Karel (referee) ; Rozman, Jiří (advisor)
The main goal in this bachelor thesis was to study the existence of electromagnetic fields in enviroment, and to study hygienic regulations. Then, to study functions of measurment system EMR-30 and to study UI of geographic information system ArcView and it´s abilities for data processing. Measurement of electromagnetic fields was carried out in the neighborhood of campus Pod Palackeho vrchem. For processing the measured data, creating maps and subsequent analysis were used programs ArcMap 10.1, ArcScene 10.1 and add-ons.
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Calculation and optimization of synchronous servomotor reluctance torque.
Kroupa, Martin ; Hájek, Vítězslav (referee) ; Ondrůšek, Čestmír (advisor)
This work is mainly focused on construction and design simulation of synchronous servomotor. This motor is built by 30 permanent magnets which are attached to rotor and solved in Ansoft Maxwell 14 software. The main purpose was to calculate reluctance torque, which is significant during the motor operational mode and its optimization. Ansoft Maxwell 14 can analyze in 2D mode as well as in 3D mode, for analysis it uses method of finite elements. Subjects can be analyzed in static conditions, or in any way of transient movement. Optimization in 2D, where we will change the shape in the area of air gap, will only be used as revision that the reluctance torque is bounded with this factor. The main simulations were supposed to be done in 3D model, where the role of rotation should have been taken in account to the final result. These simulations were replaced by alternative calculation. On behalf of achieved results, the optional rotation is stated in the end of my work.
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Design and Realization of Metamaterial
Kovaľová, Soňa ; Drexler, Petr (referee) ; Nešpor, Dušan (advisor)
The thesis discusses the design of periodic resonant structures, studying of their impact to surrounding electromagnetic field and realisation of magnetoinductive lens with potential application in nuclear magnetic resonance imaging. Frequency tuning of structure by variation of different parameters is described. The finite element method in Ansys HFSS was used to analyse the properties of designed structures.
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Calculation of electrodynamic forces in 630 A circuit breaker
Staněk, Pavel ; Bušov, Bohuslav (referee) ; Valenta, Jiří (advisor)
The aim of this thesis is to simulate the action of electrodynamic forces on current carrying path and a movable contact of the circuit breaker OEZ Modeion BH 630NE. For the calculation there is used the simulation program Ansys Maxwell. The first part is devoted to theoretical analysis of electromagnetic forces on a conductor in a magnetic field. Further I discuss the constructional design of the circuit breaker itself, especially the current path and the contact mechanism. In the next part there is (with using program Autodesk Inventor) created a simplified 3D model of the current path including an arc chamber. With program Ansys Maxwell then there is performed simulation of the acting of forces in each mode. This is magnetostatic and transient analysis for symmetrical and asymmetrical flow of the fault current. In conclusion the results obtained are evaluated and processed in the tabular way.
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