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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.
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Design of passive optical network
Žák, Ondřej ; Münster, Petr (referee) ; Reichert, Pavel (advisor)
Diploma thesis is dealing with access networks, especially with the passive optical network. The theoretical part is a list of different types of passive optical access networks, including theirs basic description, which then goes on to feature connectivity options for optical units, customers, including topology of distribution network. Analysis of different types of networks and the possibility of physical and logical design is the basis for successful design and prepa-ration of future optical access networks. Practical part is devoting to data analysis of measurement existing metropolitan network to be used for construction of optical access network in Brno, Ţlutý kopec – Preslova location. Data evaluation showed possibility of connecting with already installed network hence is created proposal of optical access network mentioned before. Selected location is analysed in detail and illustrated on situational scheme of location and customers, whose will be passive split-ters to central office. Consequently is developed project of optical access network based on data analysed date from measurements. Project is study and description of planned solution of optical access network in order to bring Triple Play services to customers. Within the interpretation of the feasibility of the project and verification physical layer pa-rameters of network was made a simulation in OptiSystem. The possibility of successful op-eration of the optical access network with the attributes entered in its design is approved in accordance with the evaluation results. The proposed network is passive in character of GPON standard, and the text describes in detail physical layer, proposed transmission speed, wave and attenuation plan of optical net-work. The work implies a specific line of HDPE ducts and microducts in them, including drawing the maps and identification in-depth. The work contains a description of the elements that are installed on the route – the number, type and eventually its length. Diploma thesis is introducing the technology and construction sequence of access network leading to its opera-tional state.
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Turbochargers with electric support
Žák, Ondřej ; Kučera, Pavel (referee) ; Píštěk, Václav (advisor)
This bachelor's thesis is aimed at supercharging combustion engines and comparison of different approaches in this field. There are mentioned mostly methods of multistage supercharging and turbocharging with electric support. Main subject of this paper is technology with future applications.
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The manufacturing of sheet metal part by blanking technology
Žák, Ondřej ; Císařová, Michaela (referee) ; Peterková, Eva (advisor)
ŽÁK Ondřej: The manufacture of sheet metal part by blanking technology The project elaborated in frame of engineering studies branch 2307. The project elaborated in frame of bachelor studies in engineering technology field set up proposal technology of production of feed lame – a section from steel metal plate 11 320. Processual shearing was suggested on the basis of belles-lettres problem of blanking and calculation. Shearing use standardized component and is solved by form of usual rack close set on press LEN 25-C, with nominal ductile by force 250 kN. Blanking puch and blanking are made from 19 class alloyed instrumental steels, heat treated according to graphical documentation.
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Shopping Gallery
Žák, Ondřej ; Hron, Lukáš (referee) ; Pilgr, Milan (advisor)
Master's thesis addresses the design and assessment of the load bearing structure of the shopping gallery. The building is designed as a three-storey rectangular plan with a flat roof. The structure is composed of steel frames and composite steel and concrete slabs. There are proposed two possible solutions - variant with a flat roof and direct central gallery, a reinforced rigid steel frames and a variant with a cupola roofed circular inner atrium, solidified with rods.
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Efficiency Improvement of Three Phase Induction Motor
Žák, Ondřej ; Mach, Martin (referee) ; Vítek, Ondřej (advisor)
This bacelor thesis looks into problematics of efficiency of induction elektromotors. Due to present tendence of permanently encreasing efficiency, this topic is very actual. How to encrease efficiency but not to encrease material and production cost too much? This is the daily question of every producer of induction elektromotors. This thesis has a target to bring closer understanding of this problematics and describe alternatives, which is possible to follow. On choosen elektromotor produced by ATAS elektromotory Náchod a.s. is made an comparison of analytic calculate, calculate of software RMxprt and Maxwell 2D and real measuring, which refes about limits of individual calculatin methods. Then the design of changes with new calculate is provided and comparison of all results.
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Design of Asymmetrical Parabolic Spring
Žák, Ondřej ; Prokop, Aleš (referee) ; Ramík, Pavel (advisor)
This thesis is focused on design of parabolic spring for a truck. Characteristics of the spring are designed with respect to loads during heavy braking. Thesis contains a brief summary of current truck suspension, the spring design and suggestion for testing methodology for longitudinal load.
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Design of interior permanent magnet synchronous motor
Žák, Ondřej ; Mach, Martin (referee) ; Vítek, Ondřej (advisor)
The thesis describes problematics of synchronous motor with permanent magnets. The design is provided by analytic and empiric procedures. The great accent is placed on the description of the magnetic circuit of the motor. The finite element method analysis of designed motor is performed subsequently. The main target of this thesis is to find the way, how the ferrite permanent magnet should be used in synchronous motor.
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Load bearing structure of the hall
Žák, Ondřej ; Sýkora, Karel (referee) ; Straka, Bohumil (advisor)
Bachelor's thesis solves the design and assessment of the load bearing structure of multipurpose hall. The building is designed as a single-storey, octagonal plan, with a shed roof. Construction of the hall consists of a set of frames. The supporting structure is designed in two versions - three-hinged frames with curved corners or as two-hinged frame with a large finger joint. The three-hinged frame option is solved in detail.
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Compounds combining pyrazinamide and p-aminosalicylic acid fragments as potential antituberculars II
Žák, Ondřej ; Zitko, Jan (advisor) ; Miletín, Miroslav (referee)
COMPOUNDS COMBINING PYRAZINAMIDE AND P-AMINOSALICYLIC ACID FRAGMENTS AS POTENTIAL ANTITUBERCULARS II ŽÁK ONDŘEJ Department of Pharmaceutical Chemistry and Drug Analysis, Faculty of Pharmacy in Hradec Králové, Charles University, Czech Republic A series of new compounds combining pyrazinamide and p-aminobenzoic acid was prepared and in vitro tested for antimycobacterial activity against M. tuberculosis, M. avium, M. kansasii, M. aurum and M. smegmatis. Previously prepared 4-(5-chloropyrazine-2-carboxamido)-2-hydroxybenzoic acid (R1 = OH) exerted micromolar activity against M.tuberculosis and low in vitro cytotoxicity in HepG2 cells. Para-Aminosalicylic acid (PAS) has significant antitubercular properties based on its resemblance to p-aminobenzoic acid and interference with the folate pathway in mycobacteria. To assess the role of the PAS fragment, we designed and prepared derivatives with modified substitution on the phenyl ring (R1 ). Further modification was the exchange of 5-Cl on the pyrazine core for (alkyl)amino substituent (JZ-OZ), which was a successful modification in previous series. Final compounds were described by melting point, elementary analysis, IR spectroscopy and 1 H, 13 C NMR. Changing the PAS fragment, when we removed or replaced the OH-group at position 2, the antimycobacterial...
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