National Repository of Grey Literature 10 records found  Search took 0.00 seconds. 
Geothermal energy - influence of the borehole geometry
Leiter, Augustin ; Frankovská,, Jana (referee) ; Hrubešová,, Eva (referee) ; Miča, Lumír (advisor)
Geothermal energy is one of the oldest forms of energy on our planet. Its use by humanity dates back to the beginning of the ages. The forms of this energy gradually changed from the direct heat of the hot springs, through the heating of the buildings and the baths to the later use of superheated steam for industrial use. Nowadays, there is a large share of the use of large number of ground geothermal boreholes with heat exchangers drilled in the matrix. The geometric arrangement of such system has a considerable impact on its operation. Specific examples show that, unlike the design, actual boreholes in such system can often be drilled non vertically or even curved. These imperfections then usually deteriorate the thermal properties of the system. This thesis demonstrates the influence analysis of the borehole geometry distortion on the system thermal properties, it also informs about the development of a special measuring device designed to obtain information about the actual geometric shape of the investigated borehole and about the development of software for in situ rapid borehole system properties evaluation. The theoretical part of thesis contains the derivation of a simplified numerical model of heat conduction in the vicinity of the borehole system. Its results serve to compare the different borehole variants and the inaccuracy of borehole shaping. Using the simulations, the influence of inaccuracies in the borehole system on its thermal properties is demonstrated in several model configurations. This effect does not occur in a single borehole, but it is significantly visible in organized geothermal borehole systems. It may deteriorate system properties, but under certain circumstances its properties may improve. Verification of the results of these simulations was performed by the FEFLOW simulation software. In the practical part the development of a special instrument for measuring the shape of a geothermal energy borehole is documented. ....
Inclinometers and Gyroscopes
Hývnarová, Irena ; Beneš, Petr (referee) ; Havránek, Zdeněk (advisor)
This study deals with tilt sensors. Besides others methods, accelerometers and gyroscopes are also convenient to solve this problem. Tilt sensors which are described in this thesis are working with capacitive, piezoresistive and thermal method. Capacitive accelerometers from producer Analog Devices, STmicro and Freescale, piezoresistive accelerometers from producer Panasonic Matsushita and gyroscope ADXRS300 are tested by practical measurement. Parameters of these accelerometers are found and they are compared with parameters from producer. Measurement reliability in this study is analysed as well. This thesis is divided in chapters theoretically describing principles of particular accelerometers and the chapters containing measured data evaluation.
Using mobile phone in feedback rehabilitation
Mynařík, Ondřej ; Žalud, Luděk (referee) ; Chromý, Adam (advisor)
The aim of this thesis is to evaluate sensors used in Android mobile phones for measuring inclination and their comparation with precise reference sensor Xsens. Another goal is to create Android application for measuring inclination of balance desk. This application communicates with a computer by Bluetooth. Results indicates that sensors in mobile phones are sufficient enough to replace the precise sensor Xsens for measuring inclination of balance desk. Based on the results mobile application was created. Using a mobile phone with this application can replace Xsens, which results in rapid decrease of the price and the possible use in rehabilitation centers or by patients.
Verastile Sensor-based Experimental Platform
Tydor, Maximilián ; Ing. Vladimír Hubík, Ph.D. (Saab Czech s.r.o.) (referee) ; Šebesta, Jiří (advisor)
This document deals with issues of testing semiconductor inertial sensors like gyroscopes and accelerometers, but also other sensors like magnetometers, inclinometers and others for aviation navigation purposes where strict requirements cover every system. The goal of this thesis is to create modular test platform for testing wide variety of sensors in different combinations under variable circumstances. The development covers mechanical design, electrical design – hardware and also control algorithm – software.
Distance measurement using sensors of mobile phone
Hubr, Ivo ; Endrle, Pavel (referee) ; Lattenberg, Ivo (advisor)
Distance and the associated parameters can be measured by specific sensors mobile device. Introduction The work focuses on the description of the sensors and the effects on their accuracy. To measure the distance, there is a number of good practices, which were described and demonstrated the application implemented source code for the Android platform. The project works with a total of three sensors, namely accelerometer, magnetometer and camera. The main objective of this work is the definition and application of methods for measuring distance using the appropriate sensors.
Geothermal energy - influence of the borehole geometry
Leiter, Augustin ; Frankovská,, Jana (referee) ; Hrubešová,, Eva (referee) ; Miča, Lumír (advisor)
Geothermal energy is one of the oldest forms of energy on our planet. Its use by humanity dates back to the beginning of the ages. The forms of this energy gradually changed from the direct heat of the hot springs, through the heating of the buildings and the baths to the later use of superheated steam for industrial use. Nowadays, there is a large share of the use of large number of ground geothermal boreholes with heat exchangers drilled in the matrix. The geometric arrangement of such system has a considerable impact on its operation. Specific examples show that, unlike the design, actual boreholes in such system can often be drilled non vertically or even curved. These imperfections then usually deteriorate the thermal properties of the system. This thesis demonstrates the influence analysis of the borehole geometry distortion on the system thermal properties, it also informs about the development of a special measuring device designed to obtain information about the actual geometric shape of the investigated borehole and about the development of software for in situ rapid borehole system properties evaluation. The theoretical part of thesis contains the derivation of a simplified numerical model of heat conduction in the vicinity of the borehole system. Its results serve to compare the different borehole variants and the inaccuracy of borehole shaping. Using the simulations, the influence of inaccuracies in the borehole system on its thermal properties is demonstrated in several model configurations. This effect does not occur in a single borehole, but it is significantly visible in organized geothermal borehole systems. It may deteriorate system properties, but under certain circumstances its properties may improve. Verification of the results of these simulations was performed by the FEFLOW simulation software. In the practical part the development of a special instrument for measuring the shape of a geothermal energy borehole is documented. ....
Using mobile phone in feedback rehabilitation
Mynařík, Ondřej ; Žalud, Luděk (referee) ; Chromý, Adam (advisor)
The aim of this thesis is to evaluate sensors used in Android mobile phones for measuring inclination and their comparation with precise reference sensor Xsens. Another goal is to create Android application for measuring inclination of balance desk. This application communicates with a computer by Bluetooth. Results indicates that sensors in mobile phones are sufficient enough to replace the precise sensor Xsens for measuring inclination of balance desk. Based on the results mobile application was created. Using a mobile phone with this application can replace Xsens, which results in rapid decrease of the price and the possible use in rehabilitation centers or by patients.
Verastile Sensor-based Experimental Platform
Tydor, Maximilián ; Ing. Vladimír Hubík, Ph.D. (Saab Czech s.r.o.) (referee) ; Šebesta, Jiří (advisor)
This document deals with issues of testing semiconductor inertial sensors like gyroscopes and accelerometers, but also other sensors like magnetometers, inclinometers and others for aviation navigation purposes where strict requirements cover every system. The goal of this thesis is to create modular test platform for testing wide variety of sensors in different combinations under variable circumstances. The development covers mechanical design, electrical design – hardware and also control algorithm – software.
Distance measurement using sensors of mobile phone
Hubr, Ivo ; Endrle, Pavel (referee) ; Lattenberg, Ivo (advisor)
Distance and the associated parameters can be measured by specific sensors mobile device. Introduction The work focuses on the description of the sensors and the effects on their accuracy. To measure the distance, there is a number of good practices, which were described and demonstrated the application implemented source code for the Android platform. The project works with a total of three sensors, namely accelerometer, magnetometer and camera. The main objective of this work is the definition and application of methods for measuring distance using the appropriate sensors.
Inclinometers and Gyroscopes
Hývnarová, Irena ; Beneš, Petr (referee) ; Havránek, Zdeněk (advisor)
This study deals with tilt sensors. Besides others methods, accelerometers and gyroscopes are also convenient to solve this problem. Tilt sensors which are described in this thesis are working with capacitive, piezoresistive and thermal method. Capacitive accelerometers from producer Analog Devices, STmicro and Freescale, piezoresistive accelerometers from producer Panasonic Matsushita and gyroscope ADXRS300 are tested by practical measurement. Parameters of these accelerometers are found and they are compared with parameters from producer. Measurement reliability in this study is analysed as well. This thesis is divided in chapters theoretically describing principles of particular accelerometers and the chapters containing measured data evaluation.

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