National Repository of Grey Literature 108 records found  1 - 10nextend  jump to record: Search took 0.02 seconds. 
Impedance tube for measuring sound absorption coefficient and transmission loss coefficient
Hodinka, Tomáš ; Balík, Miroslav (referee) ; Skvaril, Šimon (advisor)
The goal of this thesis is the design and manufacture of the mechanical and electrical components of the impedance tube. The impedance tube is a tool used in laboratories, that has its parameters dictated by norms. On one side of this enclosed airtight tube is a speaker, and on the other the measured material. By switching some additional parts, the tube is capable of measuring not only the acoustic absorption, but also sound penetration. Impedance tube is made, so that it is robust, easy to manipulate and use, and easy to store. The designed impedance tube can measure the sound penetration of any material, that is up to 50mm in thickness, and the acoustic absorption of materials that are up to 120mm in thickness. Parts of the tube, that are directly welded to the tube itself are made of the same metal that the tube itself is, and the speaker enclosure is made from plywood. Along with the assembly of the impedance tube, a complete and detailed drawing documentation for future recreation is added, along with a suitable amplifier and all peripherals necessary for measurements.
Energy balance of the UWC link
Bartoň, Jan ; Látal,, Jan (referee) ; Hudcová, Lucie (advisor)
Tato semestrální práce je zaměřená na popis šíření optického svazku podvodním prostředím se zaměřením na vliv turbulentního proudění na odsměrování svazku. V první části práce je poskytnut popis vlastností podvodního prostředí a jejich vliv na optický svazek. V druhé části jsou prezentovány metody použitelné pro výpočet útlumu podvodního prostředí, zaměřující se na popis turbulentního prostředí. Ve třetí části je představena softwarová implementace algoritmu popsaného ve druhé části. Výsledkem práce je postup výpočtu síření optického svazku podvodním prostředím a jeho softwarová implementace.
The effect of optical fiber attenuation on the capacity of optical traces
Žák, Ondřej ; Škorpil, Vladislav (referee) ; Reichert, Pavel (advisor)
The essence of this thesis is the creation of complex insight on optic fibre attenuation. There is successive steps explained mechanism of optical attenuation and characterized its spectral dependence. We are describing primary elements of optical attenuation, its sorts and their own spectral dependence. Bachelor´s thesis is explaining requirements of transmission system to spectral characteristic optic fibre and influence of optic fibre attenuation on capacity of optical trace. Output of bachelor´s thesis is program solution of designed mathematical model for calcula-tion spectral dependence of optical attenuation. Program is realized in MATLAB and there is furthermore added version in Microsoft Office 1997-2003. Created program is able to ap-proximate points data obtained from measurement of optic fibre by using Lagrange interpola-tion polynomial and Rayleigh scatter interlay.
Design of optoelectronic sensor for biological tissues
Balík, Zdeněk ; Bartlová, Milada (referee) ; Tománek, Pavel (advisor)
Biological tissues are optically inhomogeneous and absorbent materials. They are comprised of various structures such as cells, cell organelles, and various fiber structures. Due to these structures leads to different interactions with the light and phenomena such as absorption, scattering and polarization of light. Different ultrasonic, electromagnetic, electrical and optical methods are used for meat ageing detection. Muscles are turbid anisotropic media, they exhibit changes in electrical and optical properties according to the direction of the electrical and optical fields in the sample. The diploma work assesses the feasibility of impedance measurements for meat ageing detection and their comparison with optical measurement of scattered polarized light. Two different sample were used: pork chop slices and chicken breasts were used for their relative homogeneity. The electrical method is a promising method due to the possibility of getting much information and realizing cheap and fast enough measurement systems. The proposed optical method allows measure the rotation of polarization plane with meat ageing in the range of 95 degrees within considered period. Through the first promising results obtained in this thesis, a further work has to be provided to determine closer relationship between optical scattering characteristics, electrical anisotropy in ageing-related tissue structural properties.
Free-Space Optics data link
Šála, Jakub ; Číž, Radim (referee) ; Šporik, Jan (advisor)
In this thesis, shows a current issue for free space optics, limiting their use in practice with regard to the availability and reliability. They conducted measurements on wireless optical links and the observed values is calculated by the availability of the connection. Subsequently, measurements are performed on alternate versions of wireless and copper connections. Observed values were compared with a wireless optical link. It is made of optical design of wireless connections at home.
Development of a Fluid Curtain for Gaseous Exhalations Absorption
Krištof, Ondřej ; Fekete, Roman (referee) ; Lapčík,, Lubomír (referee) ; Svěrák, Tomáš (advisor)
The dissertation thesis deals with the application of absorption methods for the separation of gaseous pollutants from polluted gaseous mixtures using a pilot plant scrubber. The efficiency of the gaseous pollutant removal was determined based on the hydrodynamic distribution of fluids inside the spray chamber. A TF-28 150 spiral nozzle, which was used to spray the absorption liquid, was experimentally characterized. Specifically, the pressure impact pattern of the liquid produced by the nozzle was investigated using intrusive methods and the effective spray angles, the modes of primary and secondary atomization, the droplet size and liquid velocity distributions were determined using non-intrusive optical methods. Numerical simulations of flow of model gas phase inside the sprinkler head and spraying of the liquid through the spiral nozzle were also carried out. The obtained data can be applied to estimate the interface area and together with the determination of the coefficient of total mass transfer thus define the kinetics of chemisorption for a given absorbent/absorbate combination.
Biogas cleaning to substitute natural gas quality
Němec, Jan ; Niesner, Jakub (referee) ; Dvořák, Radek (advisor)
This work deals with methods of biogas cleaning to natural gas quality for further use. The introduction is focused on technologies for biogas treatment and biogas management for current situation in the Czech Republic. In the main chapter there is a water scrubber technology design and calculation of the absorption column for the conditions given. A simulation model and preliminary economic balance were then developed on the obtained data.
Characteristics of the atmosphere of Mars for optical communication
Marčák, Tomáš ; Barcík, Peter (referee) ; Hudcová, Lucie (advisor)
The bachelor thesis is focused on the issue and research of atmosphere of the planet Mars for optical communication. The main goal of this thesis was to introduce the transmission through the atmosphere of the Mars and define possible wavelengths which could be used as possible communication. This thesis mainly introduces the optical communication and facts about the atmosphere of the planet. The main chapter presents more detailed analysis of composition of the atmosphere, the impact of the composition that is used for the radiation transmission. Lastly there are presented the results of the calculations and characteristics of the transmission through the Mars atmosphere. The next chapter is focused on theory of optical transmitters and its division. Subsequently, thesis describes the program for calculation of temporal, spatial and energetic characteristics of optical beam.
Simulation of dose distribution irradiation
Večeřa, Petr ; Hlaváč, Martin (referee) ; Kolářová, Jana (advisor)
This project deals with the issue of simulation of dose irradiation. This principle is used in a radiotherapeutic device known as a Leksell Gamma Knife for the treatment of intracranial tumours. With regard to the theoretical observations obtained by studying this device, the project suggests the use of analytical geometry for the creation of a mathematical model for calculation of the intensity in the rayed area. A demonstration program Leksell_xvecer08 has been created for this model in a MatLab software background, which enables the user to change various input arguments and simulate a picture of the dosage spread in the target scanned areas.
Utilization of absorption systems in the heating systems
Vidlák, David ; Špiláček, Michal (referee) ; Pospíšil, Jiří (advisor)
Main goal of this work is familiarization with basic features of absorption heat pumps and it’s growing importance on the market. In the first part of the work there is a research for clarifying facts associated with such pumps. In the introduction there are descriptions of basic information from the field of heating industry and its connections to our systems. Next there is a brief analysis of price changes in electricity and heat in the last five years. Main part of the analytical section is a description of the used absorption system. Second part of the work is focused on the calculation of the absorption system itself. First there is calculated internal and external part of the device according to the parameters from GE Power s.r.o. After this step there are parametric studies based on changes of key parameters of the default device for a demonstration of the behavior of a heating pump. In the end of the work there is a integration of the unit into the heating cycle for variations including flue gas condenser and using a cooling water from the turbine condenser.

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