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Vibrodiagnostics of electrical machines
Petráček, Samuel ; Cipín, Radoslav (referee) ; Janda, Marcel (advisor)
This bachelor's thesis deals with getting to know vibrations and their description. What types of vibrations occur, what are their parameters, such as deflection or acceleration, and a slightly described frequency analysis for non-harmonic signals. Subsequently, the sources of vibrations in electric rotating machines are described. Types of vibration sources are described here, for example of mechanical origin or on the bearing. The causes of their occurrence are, for example, rotor imbalance, rotor misalignment or mechanical loosening. And their subsequent effect on the machine in axial and radial directions. Furthermore, the Crest Factor measurement method and a summary of other diagnostic methods of vibrodiagnostics such as Envelope Analysis and Kurtosis Factor are described. For what purposes these methods are used and their advantages and disadvantages. In the practical part, 4 asynchronous motors were measured with prerequisites for faults with rotor eccentricity. The effective values of the vibrations and the Crest Factor were calculated here, followed by a frequency analysis using FFT (Fast Fourier Transform). In the end, the resulting data were evaluated.
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Realization of educational problem based on experimental apparatus with cam mechanism
Tomeček, Vojtěch ; Vrbka, Martin (referee) ; Vaverka, Michal (advisor)
Bachelor's thesis is focused on solving educational problem based on experimental apparatus with cam mechanism. The task of the educational problem is to teach students to analyse kinematic quantities of cam followers. The thesis contains general discourse on the topic of cam mechanisms and basic terms definition. This is followed by putting the device into service, eliminating its particular imperfections, analysis of kinematic quantities of various combinations of available cams and followers and definition of methodics of the educational problem. The educational problem itself follows the presentation and commentary of gained results. At last some recommendations for the future modifications of the experimental apparatus are given followed by foreshadow of its eventual future usage.
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Analytical centrifugation as a tool for characterization of microbial cells
Beránková, Barbora ; Müllerová, Lucie (referee) ; Obruča, Stanislav (advisor)
This bachelor thesis deals with the study of centrifugation potential of microorganisms depending on the cultivation conditions The experimental part focuses on the sedimentation velocity and the instability index of the studied microorganisms during growth, under temperature and salt stress, the influence of the medium composition on centrifugation and the effect of osmotic strength on halophilic microbe Haloferax mediterranei. The sedimentation velocity and the instability index are increasing with increasing amount of water present in the bacterial culture of Haloferax mediterranei. The presence and type of polyhydroxyalkanoate (PHA) play a role in the monitoring of growth of bacteria Cupriavidus necator H16, Cupriavidus necator PHB-4, Haloferax mediterranei, Burkholderia cepacia and Burkholderia sacchari at the rate of sedimentation and instability index. Bacteria Cupriavis necator H16 with the highest content of poly(3-hydroxybutyrate) present was the fastest sedimentating and most unstable of the bacteria studied. Bacteria Cupriavidus necator H16 and Cupriavidus necator PHB-4, exposed to temperature and salt stress, exhibited only a slight influence on the rate of sedimentation and instability under temperature stress. The sedimentation velocity and instability index decreased with saline stress with increasing concentration of NaCl solution in culture. When comparing the media composition to polyhydroxyalkanoate (PHA) producing bacteria, Cupriavidus necator H16 cultivated in the mineral medium demonstrated the lowest sedimentation velocity and instability index rates, but Cupriavidus necator PHB-4 reached the lowest sedimentation velocity and instability index when grown in Nutrient Broth medium. For yeast Saccharomyces cerevisiae, the choice of medium had only a slight effect on sedimentation velocity and instability index.
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Determining motion using accelerometer data
Montilla, Michaela ; Koťová, Markéta (referee) ; Janoušek, Oto (advisor)
The aim of this thesis is to present the topic of acceleration record using accelerometer sensors and to create a program for the transformation of the acceleration data into the position vector. It is a summary of theoretical background of data recording using sensors of acceleration and an overview of the physical relationships between acceleration, velocity and position. The data was recorded by multiple types of sensors. The gist of the algorithm is a mathematical realization of physical relations modifying the conversion of acceleration to the position. The outcome enables to display a dynamic graphic output in 3-D.
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Strain and stress analysis of the car front part under impact loading.
Hrubý, Jaroslav ; Vémola, Aleš (referee) ; Vrbka, Jan (advisor)
This work deals with the stress and strain analysis of the car front part of Škoda Octavia II. generation under impact loading using an explicit formulation of finite element method (FEM). The aim of this work is examination of resistance of the car front part under this impact loading and comparison of the data, which were get out of the FEM simulation of the car impact on the rigid wall with methods, which are used in forensic engineering. The comparison of the FEM simulation of the car impact on the rigid wall will be provided with the correlation method and with the method of energetic grid.
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Telemetric system for RC airplane with navigation
Orolin, Jakub ; Šteffan, Pavel (referee) ; Háze, Jiří (advisor)
This project is focused on design telemetric system for radio controlled aircraft. The output of the system represents relevant flight data such as velocity, altitude, direction of flight, rotation or geographical position on the map. Furthermore, the system could check all internal board status parameters. All these parameters are displayed in real time at the receiving station, which includes voice navigation for landing. Another part of the receiving station is flight recorder or a database used for registration of particular information and post - flight analysis.
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Time progression of metrological characteristics of electromagnetic current meters
Březina, Jiří ; Brázda, Martin (referee) ; Žoužela, Michal (advisor)
This experimental diploma thesis investigates the changes in the metrological characteristics of the electromagnetic current meter of velocity. The theoretical part of the thesis includes a brief summary of technical and metrological characteristics of these types of devices. In addition, it describes the tested device, the test track, and the measurement procedure, which consists of two variants: long-term monitoring with a relatively regular monthly measurement interval and short-term monitoring with a regular daily measurement interval. The evaluation of the experimental work focuses on the repeatability and variability of the displayed point speed values and their stability over time. Furthermore, the parameters reported by the meter during long-term and short-term monitoring are compared to each other. The results are also compared with similar experiments.
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JIRA Plug-In for Automatic Ticket Assigning
Kučerová, Pavla ; Bartík, Vladimír (referee) ; Kreslíková, Jitka (advisor)
This work is aimed on creating plug-in module for the system Atlassian JIRA. The module was developed based on the requirements of real company and provided as a project corresponding with business processes. The main objective was to extend the functionality of used system and to design project delivery process modifications for projects of similar type.
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Effect of Active Vehicle Safety in the Prevention of Road Accidents
Franc, Šimon ; Frič, Jindřich (referee) ; Panáček, Vladimír (advisor)
This diploma thesis focuses on effects of active vehicle safety on the prevention of traffic accidents. In the introductory section, the term of active safety is defined and divided into four categories. In next four chapters, the particular elements of active safety are described in more detail and some selected elements are described in depth. Chapter seven includes a questionnaire; it enquires opinions of people about some of the elements of active safety. Practical road tests were conducted as part of this work. Theirs description and evaluation are in the last chapters.
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