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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
321

Mikroelektrodová pole pro bioelektroniku / Microelectrode arrays for mioelectronic

Bráblíková, Aneta January 2019 (has links)
Organic electronic biosensors are developed as suitable devices that can transform electrochemical processes within the cell membrane into an electronic signal and enable to measure electrical activity of excitable cells and tissues both in vitro and in vivo and thus represent valuable alternative to current cell monitoring methods. In this work we focus on the fabrication of electrophysiological sensors based on organic semiconductors printed by the material printing method. Microelectrode arrays (MEAs) are active components of the device, which can monitore cellular activity and above that stimulating cells with electrical pulses. The proposed platform should be used for cytotoxicity of potential drugs especially on cardiac cells (cardiomyocytes). The experimental part focus on specific production processes of platforms, which were prepared in the laboraty with emphasis on biocompatibility and conductivity of device.
322

Akustická detekce pozice řečníka pomocí mikrofonního pole / Acoustic Detection of Speaker Position Using Microphone Array

Pelz, Zdeněk January 2019 (has links)
This thesis explores problematics of speaker localization using microphone array. Aim of this thesis is implementation of algorithms for speaker localization and experiments with those algorithms. Calculation of TDOA was done using cross-correlation and hyperbolic method was used to calculate position estimation. Finished microphone array is able to locate speaker within certain variance. Results of this thesis allow reader to make assumptions regarding accuracy of localisation using microphone array and ARM kit with limited performance. Precision of position estimation using microphone array reached several decimeters, but this precision is dependent on distance from microphone array.
323

Hodnocení fyzikálních polí v krajinné lokalitě / Evaluation of physical fields in a landscape locality

Jílek, Michael January 2020 (has links)
The thesis is focused on gathering of theoretical backgrounds for geomagnetic measurements, measurement of electromagnetic and radiometric quantities in a natural locality, and subsequent evaluation of the obtained results from the point of view of their interrelations and in the context of hygienic regulations. All the theoretical backgrounds of each field are assigned to the measurement methodology and appropriate measuring technique, selected according to information from available sources. Appropriate instruments, landscape location, measurements were made, the results were evaluated and interpreted. The result is graphical output in the QGIS geographic information system.
324

Studie pro návrh malé kořenové čistírny na konkrétní lokalitu / Study of small vegetable waste water treatment plant design for specific locality

Netopilík, Jan January 2020 (has links)
Constructed wetland is one of ways of domestic wastewater treatment that allows reuse of treated water. The thesis acquainted with run principles, with a design for a family house, that includes different solutions of technologic parts with advice for a reliable run and theoretical financial costs.
325

Anténa s řiditelným svazkem / Beam steering antenna

Krejčíř, Dominik January 2021 (has links)
The master s thesis deals with the design of the beamsteering antenna. Methods of the beamsteering and the final antenna design are described. This antenna operates in the ISM band with the central frequency of 5,8 GHz. The antenna is designed in the CST Studio Suite 2020. Butler matrix was designed as a feed network implemented as substrate integrated waveguide. An array of patch antennas was used for radiation.
326

Mikrogenerátor / Microgenerator

Pospíšil, Kamil January 2008 (has links)
In this master’s thesis gives an overview of the finite element method (FEM) as used in electrotechnical practice. It deals with calculations of electric and magnetic fields. The task can be solved using ANSYS, FemLab, Femm, Quickfield and next software. Femm is the one I have chosen. The programs are described here, and their use is demostrated on examples. The outcome of the project is a calculation of magnetic field of a microgenerator in a stationary and dynamic field.
327

Asynchronní motor se stíněným pólem / Shaded-Pole Induction motor

Žuška, Martin January 2008 (has links)
Single-phase shade-pole motor has easy structure, and i tis chlap. It can be used as a drive of electrical fans, drive of small household appliancesor as a gramophonic motor. Motor is rotating one way only. Direction of roteting is given by positron of shading ring. Motor is not very effective, and i tis not efficient.
328

Elektrochemické senzorové pole / Electrochemical sensor array

Šulc, Jakub January 2009 (has links)
In recent years (Of late year)microelectronic technology significantly affected in the field of sensor technology, especially in the field of electrochemical sensors. This thesis deals with design and construction of thick-film voltammetric sensors array. The reason for proposal of voltammetric sensors array is to increase of speed, increase the accuracy and extension possibilities measurement compared with common systems.By reason of increase of sensitivity of these sensors it is efficient use the potentiostat chip for measurement output signal. Created sensors must fulfill the specified parameters and also requirements of thick-film technology. Next step is design the basic blocks of electronic circuit used to evaluate the measured values.
329

Měření doběhu gradientních magnetických polí v MR tomografu / Measurement of gradient magnetic field decay in MR tomograph

Kubásek, Ondřej January 2010 (has links)
The objective of my thesis is to measure magnetic field gradient decay in an MR tomograph, process and evaluate the data measured and analyse the issue. The theoretical section focuses on the reasons for the gradient distortion which has a negative impact on NMR measuring techniques and it also describes options to eliminate the negative effects, focusing mainly on pre-emphasis filtration. It also lists methods of gradient magnetic field measuring. The practical section contains results of magnetic field decay measurements taken with the tomograph in the Institute of scientific instruments of the Academy of sciences in Brno using the method of instantaneous frequency with and without pre-emphasis compensation. The data are processed with MAREVISI and MATLAB programmes. MATLAB is used to develop a modern method of filtration to eliminate noise in useful signal leading to more accurate measurements of MR magnetic fields. This filtration uses a method of time-dependent variable thresholds and two-channel filter banks. MATLAB is also used to design a programme for approximation of the measured gradient magnetic field decay. The decay must be approximated in order to obtain time constants and the degree of exponential decay, which serve to set up the pre-emphasis compensation.
330

Identifikace zdrojů hluku pomocí beamformingu / Noise Source Identification Using Beamforming

Kurc, David January 2011 (has links)
This master's thesis is focused on the noise source identification using microphone arrays and beamforming as the signal processing method. It describes parts of such a system and provides a comparison with other systems that serve a similar purpose (eg. NAH). Various types of microphone arrays are mentioned with their influence on the resulting ability to identify the noise source. We are further focusing on Delay-And-Sum technology, on which we are explaining the basic principles and constraints of beamforming. The practical part describes the implementation of the DAS method in MATLAB and C language, the specific structures of built microphone arrays and assembly of complete systems capable of identifying sources of noise. These systems were tested by performing a practical experiment. Achievements in the form of distribution maps of acoustic energy in the focused space are interpreted in the last chapter.

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