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Monitoring stress in the mast
Bednář, Tomáš ; Beneš, Petr (referee) ; Bejček, Ludvík (advisor)
The subject of this bachelor´s thesis is an issue of measurement and monitoring stressing in the mast – high voltage and very high voltage.The solution of query, including the producer and the users, is also presented. The aim of this thesis is to propose sensors for this measurement and making practical measurement of the concrete very high voltage mast.
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Design and set up of a laboratory sample of a laser deflectometer for measurement of mechanical stress within thin films
Šustek, Štěpán ; Klapetek,, Petr (referee) ; Ohlídal, Miloslav (advisor)
This diploma thesis describes the design of a device for measuring stress in thin films – laser deflectometer, realization of its design and its experimental testing. The thesis is divided into five chapters. The first chapter deals with the stress in thin films and its influence on substrate – thin film system. The second chapter provides an overview of devices widely used for measuring stress in thin films and describes some their advantages and disadvantages. In the third chapter some design possibilities of the device are presented. The final solution of device called deflectometr is introduced in the fourth chapter. The last chapter includes the functional testing the device.
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THE UNCERTAINTIES DEFORMATION AND STRESS USING THE STRAIN GAUGES
Dokoupil, Pavel ; Vlk, Miloš (referee) ; Koška, Petr (referee) ; Habán, Vladimír (advisor)
The dissertation thesis deals with the determination of uncertainty of strain measurement and the stress using resistance strain gages. You can find two methods to define the uncertainty in the thesis, GUF and MMC, and both are applied for measurements carried out with resistance strain gages. Definition of the measurement uncertainty was set for the strain measured by uniaxial and biaxial strain gages. The uncertainty of the stress was defined for linear strain gages, T Rosettes and Rosettes. There were universal mathematic-technical models defined to measure strain and stress, these models can be used either for standard and special measurements i.e. high-temperature, or for measurements in radiation field. Each part of the strain uncertainty and stress is analyzed from the point of view of a size of uncertainty and a form of probability of the function that strain and stress can adopt. The maximum focus was dedicated to the mistakes influencing measured strain like strain gage properties, installation and operating influences, external influences, time effects and the influence of the measured object. There are two mistakes influencing the stress described and analyzed in the thesis, the mistake of the Young’s modulus of elasticity and the mistake of the Poisson’s ratio. The thesis is conceived as a complex of information related to the measurement uncertainties using the resistance strain gages and methods of defining the measurement uncertainty in a way that the experimenter can apply the gained info and methods in the required measurements. The final chapters give representative examples to define measurement uncertainties for uniaxial and biaxial stress applying GUF and MMC method. The thesis also includes the experiment that compares measured values of strain, stress and measurement uncertainties, using several different types of strain gages at different temperatures, with theoretical calculation of strain and with stress. The experiment was carried out using the displacement sensor that works on an elementary principle of bending load.
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Distributed measurement of acoustic vibrations and temperature
Bukovský, Jan ; Záviška, Pavel (referee) ; Münster, Petr (advisor)
This work deals with the problem of vibration and temperature measurement using standard telecommunication optical fibers. The main focus of this work is on the measurement of these parameters with distributed acoustic sensing systems (DAS). In this work are also discussed the issues of vibration and temperature measurement with distributed strain and temperature sensing systems (DSTS), with distributed temperature sensing systems (DTS) and with interferometric systems. As part of this work, measurements were made in the laboratory with a commercial DAS system. During these measurements, vibrations and temperature changes around the fiber were simulated. Several methods of data processing have been proposed to evaluate the measured data. The proposed methods of data processing and evaluation of the measured data can be found in the last part of this work.
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THE UNCERTAINTIES DEFORMATION AND STRESS USING THE STRAIN GAUGES
Dokoupil, Pavel ; Vlk, Miloš (referee) ; Koška, Petr (referee) ; Habán, Vladimír (advisor)
The dissertation thesis deals with the determination of uncertainty of strain measurement and the stress using resistance strain gages. You can find two methods to define the uncertainty in the thesis, GUF and MMC, and both are applied for measurements carried out with resistance strain gages. Definition of the measurement uncertainty was set for the strain measured by uniaxial and biaxial strain gages. The uncertainty of the stress was defined for linear strain gages, T Rosettes and Rosettes. There were universal mathematic-technical models defined to measure strain and stress, these models can be used either for standard and special measurements i.e. high-temperature, or for measurements in radiation field. Each part of the strain uncertainty and stress is analyzed from the point of view of a size of uncertainty and a form of probability of the function that strain and stress can adopt. The maximum focus was dedicated to the mistakes influencing measured strain like strain gage properties, installation and operating influences, external influences, time effects and the influence of the measured object. There are two mistakes influencing the stress described and analyzed in the thesis, the mistake of the Young’s modulus of elasticity and the mistake of the Poisson’s ratio. The thesis is conceived as a complex of information related to the measurement uncertainties using the resistance strain gages and methods of defining the measurement uncertainty in a way that the experimenter can apply the gained info and methods in the required measurements. The final chapters give representative examples to define measurement uncertainties for uniaxial and biaxial stress applying GUF and MMC method. The thesis also includes the experiment that compares measured values of strain, stress and measurement uncertainties, using several different types of strain gages at different temperatures, with theoretical calculation of strain and with stress. The experiment was carried out using the displacement sensor that works on an elementary principle of bending load.
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Analysis of dynamical interactions of axon shafts and their biopysical modelling.
Šmít, Daniel ; Zápotocký, Martin (advisor) ; Reingruber, Jūrgen (referee) ; Maršálek, Petr (referee)
in English While axon fasciculation plays a key role in the development of neural networks, very lit- tle is known about its dynamics and the underlying biophysical mechanisms. In a model system composed of neurons grown ex vivo from explants of embryonic mouse olfactory epithelia, we observed that axons dynamically interact with each other through their shafts, leading to zippering and unzippering behaviour that regulates their fasciculation. Taking advantage of this new preparation suitable for studying such interactions, we carried out a detailed biophysical analysis of zippering, occurring either spontaneously or induced by micromanipulations and pharmacological treatments. We show that zippering arises from the competition of axon-axon adhesion and me- chanical tension in the axons. This is upheld on quantitative level by conforming change of network global structure in response to various pharmacological treatments, without active involvement of growth cones. The calibrated manipulations of interacting shafts provide qualitative support for the hypothesis, and also allow us to quantify the mechan- ical tension of axons in our system. Furthermore, we introduce a biophysical model of the zippering dynamics, which efficiently serves the purpose of estimating the magnitude of remaining involved...
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Design and set up of a laboratory sample of a laser deflectometer for measurement of mechanical stress within thin films
Šustek, Štěpán ; Klapetek,, Petr (referee) ; Ohlídal, Miloslav (advisor)
This diploma thesis describes the design of a device for measuring stress in thin films – laser deflectometer, realization of its design and its experimental testing. The thesis is divided into five chapters. The first chapter deals with the stress in thin films and its influence on substrate – thin film system. The second chapter provides an overview of devices widely used for measuring stress in thin films and describes some their advantages and disadvantages. In the third chapter some design possibilities of the device are presented. The final solution of device called deflectometr is introduced in the fourth chapter. The last chapter includes the functional testing the device.
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Monitoring stress in the mast
Bednář, Tomáš ; Beneš, Petr (referee) ; Bejček, Ludvík (advisor)
The subject of this bachelor´s thesis is an issue of measurement and monitoring stressing in the mast – high voltage and very high voltage.The solution of query, including the producer and the users, is also presented. The aim of this thesis is to propose sensors for this measurement and making practical measurement of the concrete very high voltage mast.
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