National Repository of Grey Literature 12 records found  1 - 10next  jump to record: Search took 0.01 seconds. 
Invasive pest species in fruit crops in the Czech Republic
Holý, Kamil ; Stará, Jitka ; Kocourek, František ; Ouředníčková, Jana ; Skalský, Michal ; Pultar, Oldřich
The publication summarizes the basic information about invasive pest species in fruit orchards, spreading to our country since 2000. Information about morphology, similar species, area of origin, distribution in Europe and Czechia, risk of introduction, life cycle, host plants, methods of monitoring and control, are provided for each pest species.
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Measurement system for determination of the piezoelectric charge coefficient
Kašpárek, Ondřej ; Skalský, Michal (referee) ; Fialka, Jiří (advisor)
The master's thesis deals with methods of measuring material coefficients of piezoelectric materials with a focus on direct methods of measuring piezoelectric charge constant. The first chapters of this paper focus on the theory of the piezoelectric effect, the description of piezoelectric material coefficients, and the theory of direct measurements of piezoelectric charge constant, where is the generated charge, which corresponds to the mechanical load, measured. The next part of this thesis deals with designing and creating advanced measuring systems based on the quasi-static method, which are measuring the electrical response of the material to a step-change in force or a harmonic force signal straining the testing sample. In the last part, the influences on the measurement results, such as the use of electromagnetic shielding, are investigated using the created measurement systems.
Fiber-Coupled Fabry-Pérot Interferometric Sensor: Analysis And Modelling
Skalský, Michal
This paper presents a theoretical analysis of the Fabry-Pérot interferometric sensor utilizingan extrinsic fiber-optic cavity. Its behavior is modelled and simulated for various conditions,showing the key properties of the different sensor’s setups. The simple single-mode sensing tip andthe GRIN collimator are compared. Further, new kind of sensing head is proposed exhibiting aninverse reflectivity and enabling a theoretical resolution less than 1 pm.
Acoustic fields visualization using laser interference
Raffay, Tobiáš ; Havránek, Zdeněk (referee) ; Skalský, Michal (advisor)
This bachelor thesis is focused on solving the visualization of acoustic waves using laser interference. The necessary theoretical knowledge to understand the used method of schlieren photography are summarized in the theoretical part. The practical part describes the implementation and results of the assembled systems, shows the differences, and solves the problems that occurred during testing. Apart from visualization of acoustic waves, we can also observe the flow of gases and air with small changes of refractive index.
Fiber-optic liquid level sensor
Ondra, Dominik ; Beneš, Petr (referee) ; Skalský, Michal (advisor)
This text summarizes scientific principles that are used in fiber optics field, and could be used to design liquid level sensor. Different types of optic fibers and advanced optic structures are analyzed for liquid level sensor usage. Mechanisms of already existing types of optic fiber liquid level sensors and other mechanism liquid level sensors are characterized. Three sensor designs are proposed. One working with different levels of auttenaution when bending the fiber. The other meassuring different refraction indexs of the environment and the last one based on phase delay of light. Viabillity of these principle has been tested. Text also describes optic fiber splicer Fujikura FSM 100P+ and optic fiber sturctures that it is able to produce. Sensor based on refraction index of environment has been calibrated.
Double-Beam Mach-Zehnder Interferometer Forthin Piezoelectric Films Measurement
Skalský, Michal
This paper describes a Mach-Zehnder double-beam interferometer for measurement of piezoelectric films thickness displacement. The measurement of the sample from both sides with probing beam leads to suppression of bending effect, which can otherwise strongly degrade the results acquired by other methods. The performances of the setup were tested on a reference PZT sample. The measured piezoelectric coefficient was in agreement with its theoretical value. The described setup utilizes minimal number of the optical components which are necessary for controlled phase drift compensation. Further techniques for performance enhancement are also proposed.
Compact Fiber-Optic Current Sensor Utilizing Multiple Modes
Skalský, Michal
In this paper, a simple and compact fiber-optic current sensor utilizing a standard telecom fiber is demonstrated. The sensor employs a Faraday effect introducing a circular birefringence, which is added to a birefringence induced by fiber coiling. The experiments revealed that multi-mode propagation of light with wavelength of 633 nm may exhibited much better sensitivity to the Faraday effect and is less harmed by the parasitic birefringence compared to single-mode beam with 1550 nm.
Measurement of sound fields using non-contact optical methods
Karásek, David ; Skalský, Michal (referee) ; Havránek, Zdeněk (advisor)
The purpose of this paper is to assemble measurement chain dedicated to contactless measuring of acoustic fields emitted by test sources and to validate its results. At first author discusses possible optic methods which can be used to measure acoustic fields, then he talks about theoretical foundations which are needed to measure data and to reconstruct final data. The last two chapters are dedicated to cover basics about created program and to analyse various aspects which influence measured and reconstructed data. Created measurement chain is fully functional, at the end of this thesis are proposed some ways of improving
Fiber-Optic Displacement Sensor Based On Fabry-Pérot Interferometer
Skalský, Michal
This paper describes a simple and inexpensive fiber-optic sensor for dynamic displacement measurement with sub-nanometer resolution. The principle is based on creating a resonator cavity between measured surface and a single-mode fiber, working as a Fabry-Pérot interferometer. The fundamental principles like diffraction, spatial filtration or the role of reflectivity are analyzed theoretically and their effect on the sensitivity is explained. The sensor is then tested experimentally with an uncoated fiber tip and a gold mirror. Based on the spectral analysis, the effect of working distance on interference visibility is explained.
Closed-Loop Interferometric Fiber-Optic Gyroscope with Unpolarized Light
Skalský, Michal
This article deals with utilizing special techniques to improve parameters of interferometric fiber-optic gyroscope (I-FOG) using unexpensive single-mode (SM) fiber and based on all-fiber components. Firstly, it was shown that polarizer must be used to compensate for depolarizing unperfections. Optimization of Er-doped superfluorescent fiber source (SFS) greatly increased SNR of the sensor. Finally, solution for closed-loop operation with slow piezoelectric phase modulator was found yielding significant extension of measurement range as well as its linearity.

National Repository of Grey Literature : 12 records found   1 - 10next  jump to record:
See also: similar author names
1 Skalský, Marek
6 Skalský, Miroslav
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