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Use of EIS method for determination of sedimentation in stady liquid
Hradilová, Iva ; Vachovec, Roman (referee) ; Špano, Miroslav (advisor)
Determination of interface between sediment and liquid belongs to common tasks in various fields of industry like sewage and/or water treatment. The aim of presented work is verification of suitability of electrical impedance spectrometry (EIS) method for determination of interface between soil and water. The suitability was verified on three samples of soil. The first one was a sand while other two were loam of different grain sizes. Introduction of both the EIS method and Z-meter III instrument used for measurements is presented in this work too. Within conclusions the suitability of the method and provability in determination of water-soil interface are discussed.
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Proposition of conductive silicate composite for heating
Surovcová, Jana ; Černý, Vít (referee) ; Drochytka, Rostislav (advisor)
The bachelor's thesis deals with the development of electrically conductive silicate composite with the self heating value designed for surfaces in the exterior, on which an ice layer can form during the winter. The developed silicate composite should replace the defrosting of surfaces with chemical defrosting substances, which could have an adverse impact on the environment and are usually applied with a delay when a sudden change of weather appears. The theoretical part of this thesis summarizes the theory of electric field and electric current conduction, approached the issue of silicate binders, various types of electrically conductive phases and presents the current state of knowledge in the field of research of self heated composites. The practical part contains an assessment of selected effects of the exposure environment, based on which the requirements for the developed composite are formulated. Furthermore, the practical part is devoted to the analysis of necessary materials for producing self heated composite, so the focus is on conductive fillers. Selected fillers with the low level of the impedance are then used in the proposed recipes and the production of test specimens for the comparison of real parameters and the required ones. The work succeeded in proving the ability of heating the silicate composite with a conductive filler by means of an electric current, while the required mechanical parameters were not achieved. The bachelor thesis serves as a suitable basis for further research linked to the issue of electrically conductive self heated silicate composites.
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Design and realzation of electric measurements on biological tissues
Kocová, Lucie ; Palai-Dany, Tomáš (referee) ; Tománek, Pavel (advisor)
This master’s thesis is focused on the electrical properties of biological tissues and flesh in particular. Their electrical characteristics depend on the physical and chemical parameters that determine the concentration and mobility of ions in metabolic fluids. From the electrical point of view, flesh can be simply substituted by a field of elongated conductive cells which are separated by the insulating membrane from each other. In the next part, the Fricke model is introduced. The model describes the measurement of impedance of the tissue at low and high frequencies. The aim of the work is to assess how the impedance of the dielectric sample is dependent on the frequency of the electrical signal during the optimal aging or ripening of flesh.
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Magnetic loop antenna with electronic tuning for frequencies below 30MHz
Burda, Miroslav ; Láčík, Jaroslav (referee) ; Urbanec, Tomáš (advisor)
This project deals with electronic tuning and automated adjustment of magnetic loop antennas, working in the High Frequencys. The whole work is divided into three parts tuning, adjustment and control). The tuning part is realized by changing the capacity of the array capacitors and adjustment is done by different changes of power points. The whole system is controlled by a microprocessor ATmega16. According to utility switches the microprocessor capacity, which tunes the antenna to the required frequency, processes information about power adjustment and fine-tuning the antenna by changing the position of charging.
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Bioimpedance signal processing
Valíčková, Vladimíra ; Vondra, Vlastimil (referee) ; Soukup, Ladislav (advisor)
Theoretical part of this Bachelor thesis deals with properties measurement and use of bioim-pedance signal for medical diagnostics. The practical part deals with detection of important points in derivate bioimpedance signal that may be further used in various medical applicati-ons. This work compares three detection methods. The best results were achieved by a de-tection with fixed interval there were excluded only 1,09 % values. Very similar results had detector dependent on constant bioimpedance. Here was excreted 1.18 % of detections. Algo-rithms that are dependent on length of RR interval perform worse. Furthermore, there is cal-culated the Pulse wave velocity in six parts of the human body in a horizontal and tilt patient position. In the tilt position were the pulse wave velocity about 38.59 % faster than in hori-zontal.
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Optoelectronic sensor of polarization state of light from biological samples
Mikláš, Jan ; Brüstlová, Jitka (referee) ; Tománek, Pavel (advisor)
The living body tissues consist of cells which dimensions are bigger than a wavelength of visible light. Therefore a Mie scattering of reflected of backscaterred light occurs and different polarization states arise. The changes of polarization state due to the multiple scattering of light in the biological cellular tissues allow measure the aging of biological tissue. The reflected or backscattered polarized laser light exhibits multiple scattering on the sample surface and in its subsurface area.
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Smith Chart Visualization Tool
Marek, Martin ; Pokorný, Michal (referee) ; Kadlec, Petr (advisor)
The objective of my bachelor thesis was to create a Smith chart visualization tool in computing environment MATLAB. I created an impedance Smith chart in graphical user interface which delineate parameters of basic line types. Parameters of transmission lines can be defined in the Smith chart as normalized impedance, reflection coefficient, normalized admittance or impedance in combination with line’s characteristic impedance. It is also possible to design simple matching circuits, e.g. with quarter-wave transformer, series stub, parallel stub or matching circuits with lumped elements.
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Methods for properties analysis of transmission lines
Žůrek, Dalibor ; Kočiš, Luboš (referee) ; Hadinec, Michal (advisor)
This work focuses on a search of available literature on the theory of transmission lines and verify the possibility of simulation processes on these lines using a suitable simulation program. Initially, for the introduction to the parameters and the phenomenon that characterize the line and are important for understanding the issue. These parameters are then measured and compared with traces from the simulation in program PSpice. In another part of the work, the reader is familiar with the basics of reflectometry and fault detection capabilities on transmission lines with the basic reflectometry methods TDR and FDR, as well as with other methods of OTDR, MSR, and PD-FDR. For the TDR, FDR and MSR methods were made experimental measurements with a view to determining the position of the various types of faults on the tested leadership.
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The application of electrochemical impedance spectroscopy for investigation of enzyme kinetics
Pospíšilová, Michaela ; Sedláček, Jiří (referee) ; Fohlerová, Zdenka (advisor)
The application of electrochemical impedance spectroscopy (EIS) in theory and experiment for investigation of redox enzyme kinetics has been already described. The impedance studies are quite sensitive to the changes at the interface caused by adsorption of charged species and therefore can be used to study the kinetics of adsorption of macromolecules and also enables us to study enzyme kinetics since the action of the enzymes on their substrates involved modification and generation of charged species. In this work, we would explore the potential of electrochemical impedance technique to follow the kinetics of glucose oxidasesubstrate reactions on the immobilized surface. The enzyme will be allowed to interact with different concentrations of its substrate and the resulting reaction will be recorded in real time. Changes in the imaginary component of the impedance at various substrate concentrations will be expected to follow MichelisMenten kinetics. The experimental procedure should be simple and can be carried out directly in buffer solutions most suited for the required interaction to take place, without the requirement of any additional redox probes.
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Construction of an impedance analyzer
Slinták, Vlastimil ; Smékal, Zdeněk (referee) ; Mikulka, Jan (advisor)
The aim of this master’s thesis is to build stand-alone impedance analyzer for mesasuring antennas’ impedance. The vector network analysis is used as measuring method. Analog (with directional coupler and gain and phase detector) and digital (with 8bit AVR microcontrollers) part of analyzer are described and then build.
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