National Repository of Grey Literature 39 records found  1 - 10nextend  jump to record: Search took 0.01 seconds. 
Investment Plan Evaluation
Jelínek, Michal ; Nováčková, Eva (referee) ; Luňáček, Jiří (advisor)
The diploma thesis focuses on complex economic evaluation of the investment project regarding the purchase of machining centre. Based on the elaborated literature review are those findings applied to the real investment project. Economic efficiency is calculated using the identified cash flows, discount rate and static and dynamic methods. Subsequently are identified project risks and their significance. In conclusion, the results are summarized and is reported recommendation whether or not to implement the project.
Design of the method to increasing of accuracy of the tunable optical filter optical spectra measurement
Jelínek, Michal ; Holík, Milan (referee) ; Mikel, Břetislav (advisor)
The thesis deals with the method for the improvement of the measurement accuracy in the optical frequency spectra measurements based on tunable optical filters. The thesis starts with the selection of the proper optical filter that is suitable for accurate light spectrum measurement. The selected filter was then used for the design and realization of the measurement system for the inspection of the fibre Bragg gratings. The system incorporates a reference block for the compensation of environmental influences, an interferometric verification subsystem and a PC - based control software implemented in LabView. The preliminary experimental verification of the measurement principle and the measurement system functionality were carried out on a testing rig with a specially prepared concrete console in the UJV Řež. Advanced tests were conducted on nuclear power plant’s containment shape deformation measurement in Temelin.
Design of the optofiber sensor system to monitoring change of length
Jelínek, Michal ; Stehlík, Jiří (referee) ; Mikel, Břetislav (advisor)
The bachelor´s thesis deals with design and verification of optical fiber sensor system for measuring changes of length. This system is designed to shape monitoring of the nuclear power plant containment. The principle of measurement, design and realization of the first version is described in the work. Principle of measurement and functionality of the whole system was verified by measurement of specially prepared reinforced concrete console. The console was prepared in the way to simulate behaviour of containment of the nuclear power plant. Within development of system there were prepared of optical fiber sensors with Bragg´s grattings which are later used for measurement.
Optical fibres for ionising radiation measurements
Zbožínek, Tadeáš ; Jelínek, Michal (referee) ; Mikel, Břetislav (advisor)
The work focuses on studying methods of measuring ionizing radiation using optical fibres. More attention is paid to their use, together with scintillation materials. The proposed method allows the connection of an electronic detector with a scintillation sensor by optical means. The interconnection provides the possibility of shielding the detector from the effects of high ionizing radiation activities. The shielded detector will thus not be subject to the adverse effects of this radiation and can be used even for long-term measurements of high activities. First experimental measurements of reference sources verify the principle of the proposed method and help to select the best choice for the type of optical fibre.
Fibre optic tapering and shaping methods for special applications
Hruška, Andrej ; Jelínek, Michal (referee) ; Mikel, Břetislav (advisor)
The thesis deals with the tapering of optical fibres and the shaping of their ends. The thesis describes the fibre tapering and shaping methods and compares them in terms of advantages and disadvantages. It mainly focuses on methods using electric arc, flame and chemical etching. The practical part of the work describes the methodology of fibre tapering for 125 m, 400 m and 1000 m fibre diameters and the methodology of fibre end shaping for 400 m and 1000 m fibre diameters.
Laser and fibre optic measurement systems for the nuclear power industry
Mikel, Břetislav ; Jelínek, Michal
At the Coherent Optics Department of the Institute of Scientific Instruments of the CAS, v. v. i. we have long been involved in optical and fibre optic technologies and measurement methods. Currently, we have experience in research and development of Bragg grating systems and sensors, laser interferometers and last but not least fibre optic sensors of ionizing radiation.
Optical fibre dosimeter
Jelínek, Michal ; Mikel, Břetislav
In the nuclear facility, there is currently a demand for optical methods of measuring gamma radiation. For these measurements, we need very robust measurement methods and sophisticated equipment. Silica optical fibres coupled to crystal scintillators are suitable and we present results from their implementation. The scintillators detect gamma radiation and the silica optical fibres transmit the scintillation light from the scintillator to the detector. We used commercially available silica optical fibres up to 1.5 mm in diameter with different numerical apertures to transmit visible light from the scintillators to the detector.
Highly-coherent laser for precise optical frequencies dissemination
Pravdová, Lenka ; Čížek, Martin ; Hrabina, Jan ; Jelínek, Michal ; Řeřucha, Šimon ; Mikel, Břetislav ; Lazar, Josef ; Havliš, O. ; Altmannová, L. ; Smotlacha, V. ; Vojtěch, J. ; Velc, R. ; Číp, Ondřej
The paper presents a multipurpose laser with a very narrow spectral line, operating at a wavelength of 1540 nm and designed for cooled ions spectroscopy and the dissemination of precise optical frequencies over optical fibre links. The optical frequency of a commercial single-mode laser (NKT Photonics Koheras Basik) is spectrally narrowed to the level of several Hz using a high-quality optical resonator as an optical reference and an acousto-optic modulator as an active control element. The optical resonator is made of a low length thermal expansion coefficient material and is placed in a multi-shell vacuum chamber providing a stable operating environment. Optical frequency stabilisation uses PDH (Pound-Drewer-Hall) modulation and detection technique.
Optical fiber sensors for critical infrastructures and their automatic remote calibration
Mikel, Břetislav ; Jelínek, Michal
In this paper, we present our results in designing and implementing fiber optic sensors with fiber Bragg gratings and their measurement systems. We are currently implementing these developed sensors and the measurement system to measure containments at the Temelín nuclear power plant. For this systém, we have also developed and adopted an approach for remote calibration of the measured wavelength over commercial telecommunication fiber optic cables.
Optical fibers for measuring ionizing radiation
Jelínek, Michal ; Mikel, Břetislav
Optical fiber ionising radiation measurements cannot be used to continuously measure high-energy ionising radiation, especially gamma radiation. Previously presented sensors and methods use optical fibers with a scintillator on/inside the fiber, optical fibers doped with a scintillator, etc. These methods are not suitable for measuring high-energy radiation mainly due to low efficiency. Therefore, we present a measurement method where optical fibers are used only to transport the scintillation radiation to the shielded detection electronics.

National Repository of Grey Literature : 39 records found   1 - 10nextend  jump to record:
See also: similar author names
36 JELÍNEK, Martin
2 Jelínek, M.
10 Jelínek, Marek
3 Jelínek, Marian
36 Jelínek, Martin
1 Jelínek, Matěj
10 Jelínek, Michael
2 Jelínek, Milan
6 Jelínek, Miroslav
3 Jelínek, Mojmír
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