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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.
51

Analýza biologicky významných látek / Analysis of biological significant substances

Maděránková, Denisa January 2008 (has links)
Selected methods of Raman spectroscopy, like surface-enhanced Raman spectroscopy and single molecule Raman spectroscopy, are described in this diploma work. The basis of two methods for numerical modelling of optical properties of micro- and nanoparticles are prefaced. The methods are Discrete Dipole Approximation and Finite Difference Time Domain. Micro- and nanoparticles are used in surface enhanced Raman spectroscopy and other nanospectroscopic methods. Further, the main instrumentation needed for Raman spectroscopy is described. The first part of experimental section of this work is numerical modelling of photonic nanojet that occures behind dielectric microparticles. This phenomenon leads to a new technique of confocal microscopy with Raman spectra measuring. The second experimental section contains results of Raman spectra measurement with beta-carotene and surface-enhanced Raman spectra of beta-carotene in silver-sol solution.
52

Zpracování zázněje z Dopplerovského radarového senzoru / Doppler's sensor beat freqeuncy proccessing

Dušek, Martin January 2010 (has links)
This work is engaged in ways of objects speed measuring mainly helped by Doppler Effect. The sensor HB410 is described in this work and its possible elaboration output heterodyne analog signal. The calculation of objects speed is deduced from frequency of heterodyne signal. In this work is projected circuit solution for elaboration of analog signal and its digitalization. Available types and nature of microcontrollers which are elaborating digital signal and communicating with PC are summarized in this work. In the last chapter is described microcontroller's driving software and PC software for speed measure.
53

Zařízení pro ovládání mikroposuvu / Microposition control device

Kokeš, Ondřej January 2010 (has links)
Presented thesis analyses a function of the particular type of the nanopositioner with aim to suggest and construct an electronic device suitable for control of the nanopositioner slider. In presented material there is a description of the control signals and possibility of their generating in the respect of slider movement accuracy. The main goal of the thesis is to describe electronic units ranging from power supply, control processor unit part to end part that directly joint nanopositioner. There is also programme equipment for microcontroller and computer, communication description, movement measuring and calibration and draft for the close-up of the control loop for additional increase of the movement accuracy.
54

Analýza nadproudové spouště pomocí MKP / FEM analysis of overcurrent trip unit

Makki, Zbyněk January 2010 (has links)
The aim of the project was to prepare the given model of the current path in the environment of the SolidWorks programme, in order to simulate the flow path in the environment of the Ansys programme, where there was calculated the distribution of current density,voltage drops and heat loss on the the specified current track according to specified conditions. The obtained results are analyzed at the conclusion of this work.
55

Automatické měřicí pracoviště U-I charakteristik solárních článků / V-I characteristic of solar cells

Kaderka, Tomasz January 2011 (has links)
The theoretical part is to outline the possibilities of solar energy conversion, learn about the issues solar cells and describe the history of photovoltaics and photovoltaic energy conversion. Then describe principle of the measurement VA characteristics of photovoltaic cells. This issue is not as easy as it seems at first sight, because the solar cell isn’t a linear component, which is very easy to measure. Analysis of VA characteristic of photovoltaic cells affects parameters such as: light intensity, temperature, serial and parallel resistance, the slope of the light source, and more. The practical part deals with creating a workplace for automatic measurement of VA characteristics of photovoltaic cells in the LabVIEW. Challenge is to create a functional program, which automatically measures the VA characteristics not only in the lighted cells, but also in the shaded cell (diode mode). The program calculates the power and important parameters, such as short-circuit current, open circuit voltage, maximum power, current and voltage at maximum power article. The program allows you to export the measured values to a text file. In the last chapter of this work is made control measurements of three samples of monocrystal photovoltaic cell by the measuring workplace. The measurement is compared with the reference device Solar Cell Tester.
56

Simulace pohybu zdroje zvuku pro vícekanálovou reproduktorovou topologii / Simulation of sound source motion for multichannel speaker topology

Dvořák, Petr January 2012 (has links)
This paper describes the simulation of the motion of a sound source in space with several speakers. It deals mainly with the study and subsequent implementation of events necessary for simulating the motion of the virtual sound source. The theoretical part is therefore concerned with finding these phenomena and with their description. Mainly that means description of panning of the sound and of the Doppler effect. In the following practical part of the work, the previously described phenomena are applied into Matlab. In the created interface , it is then possible to select the parameters of the simulation, such as the trajectory of the motion of the virtual sound source, the number of the points of the trajectory, etc. Analyses of the generated signal are then made of the selected referential parameters of the simulation.
57

Chování feroelektrik v teplotní oblasti / The behaviour of ferroelectrics in the temperature range

Czanadi, Jindřich January 2012 (has links)
The submitted thesis describes characteristics and use of the ferroelectric material which has their utilization in electronics and electro technical industry. The thesis describes behaviour ferroelectrics in temperature range. A suitable workplace was designed and its functionality was verified in selected ferroelectrics samples dependence of temperature of components of complex permittivity.
58

Metoda ‘sledování regionů’ pro analýzu ultrazvukových sekvencí / Region tracking in ultrasound sequences

Byrtus, David January 2015 (has links)
Thesis deals with ultrasonographic contrast examinations, that are performed to assess tissue perfusion and non-invasive ultrasound method speckle tracking, overcoming the weaknesses of Doppler techniques used to scanning the movement of the tissue.
59

Měření vlastností tenkých vrstev metodami zobrazovací reflektometrie a Kerrova jevu / Measurement of thin films properties by imaging spectroscopy and magnetooptical Kerr effect

Plšek, Radek January 2008 (has links)
This thesis is divided into three main sections that deal with optical and magnetic thin films properties and their measurements techniques. Principles of the spectroscopic reflectometry and measurements of optical properties are described in the first part. Results of imaging reflectometry are most important. This technique is based on in situ monitoring of optical properties of SiO2 thin films during etching over the area cca 10 × 13 mm2. In next section magnetic properties of thin films and new apparatus built on the Institute of Physical Engineering of BUT are shown. Magnetic properties were observed by longitudinal magneto-optical Kerr effect. The construction of the device is based on a light beam with rectilinear polarization reflected from magnetic material with turned polarization. For investigation of local magnetic properties of microstructures a microscope objective focusing laser beam on the sample is used. The last part of the thesis is aimed on improving of a spin valve structure Co/Cu/NiFe. This work was done within the frame of the Erasmus project in Laboratoire Louis Néel in Grenoble. The goal was to achieve the value of GMR (Giant Magnetoresistance) as high as possible by changing of deposition parameters. This value describes the rate of resistances in different mutual directions of magnetization in trilayers.
60

Využití piezo-materiálu pro získávání elektrické energie z vibrací / Using of Piezo-material for Energy Harvesting from Vibration

Hanus, Jiří January 2009 (has links)
Master’s Thesis deals with obtaining electricity from the vibrations of the surrounding environment through piezoelectric vibration generator. To simulation piezoceramics and design mechanical parts of the generator was used simulation program ANSYS 10.0. First, parameters of the designed piezoelectric generator were numerically calculated, and then these values were compared with the real sample. Further work is in the description of material properties of piezo materials.

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