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The use of near-infrared spectroscopy for characterisation of raw material for sunflower oil production
Vystavělová, Petra ; Vránová, Dana (referee) ; Pudilová, Ludmila (advisor)
This diploma thesis provides summary information about using of near infrared spectroscopy for monitoring of high oleic acid content in sunflower seed. The calibration for high oleic sunflower seed was performed by using calibration model PLS - „Partial least squares. Gas chromatography was used as a reference method. Based on this knowledge thirty samples of high oleic sunflower seeds were measured and evaluated on this calibration. The last part of diploma thesis consist of comparison of oleic acid results measured by near infrared spectroscopy and gas chromatography used as reference method, and discussion about the measurement accuracy and evaluation of suitability of using these methods.
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Analysis of the rheological properties of vegetable oils and their components
Divílek, Petr ; Rozsívalová, Zdenka (referee) ; Frk, Martin (advisor)
This Master’s thesis is dealing with theoretical analysis of vegetable, mineral oils and synthetic fluids, and with measuring of density and viscosity of selected samples of electric insulating fluids. The main part of the thesis is focused on vegetable oils and their elements called fatty acids. Those are more detail described in separate capitols. In those capitols is described their utilization in engineering practice with focus on energetics, where vegetable oils are used in larger scale. In experimental part of the work is measurement of density and dynamic viscosity. Viscosity was measured on two different machines, first the Hoppler viscometer and on vibrating viscometer. Results of these measurement are evaluated in tables and graphs.
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Dielectric Properties of Vegetable Oils for Electrical Engineering
Spohner, Milan ; Mejzlík,, Miroslav (referee) ; Mentlík, Václav (referee) ; Liedermann, Karel (advisor)
The dissertation thesis deals with the analysis of prospective environmentally compatible electrical insulating fluids for electrical engineering in relation to their chemical structure. The thesis starts with the overview of the current state of the art and of the latest trends in the use of synthetic and biodegradable natural oils. In the experimental part were studied these oils: mineral oils, rapeseed oil, sunflower oils, soybean oil, methyl oleate, peanut oil, MCT oil, castor oil and other. Dielectric properties were measured using LRC meter Agilent 4980A including dielectric liquid test fixture Agilent 16452A and also by the Novocontrol Alpha-A analyzer. Electrical properties are presented in the frequency range 10 mHz – 1 MHz range in the temperature interval 253 K to 363 K. The work goes on with the study of the suitability of individual oils for lower temperature, including the impact of the chemical structure and formulation on electrical properties.
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Optimization of preparation and characterization of hybrid hydrogels with respect to viscoelastic and flow properties
Zhurauliova, Darya ; Kalina, Michal (referee) ; Smilek, Jiří (advisor)
This bachelor thesis focuses on the study of hybrid hydrogels that combine the properties of the hydrogel system together with oleogels, which is a gel on the base of oil. The aim of the thesis is to carry out a study of the current state of the solved issue on the topic of preparation of hybrid hydrogels, on this basis to design and optimize the appropriate procedure of preparation and in the form of viscoelastic measurements to perform the basic reological characterization of the prepared systems. A system based on sodium alginate dissolved in deionized water and meshed with calcium chloride solution was chosen as a suitable hydrogel system, and a system based on beeswax dissolved in sunflower oil was chosen as oleogel. Sodium alginate has been chosen because it is used as a thickener, emulsifier, stabilizer or gelling agent in the creams and preparation of pharmaceutical forms. By mixing hydrogels and oleogels of different proportions, a hydrogel/oleogel system, also called bigel, was created, the properties of which were tested in terms of flow and viscoelastic properties. In the practical part, amplitude, frequency and flow tests of both the hydrogel itself and the hybrid hydrogel with a ratio of 50:50 (hydrogel vs. oleogel) were measured. These tests provided information on gel preparations, i.e. what is their character, what are the mechanical properties and how it depends on the amplitude of deformation. By comparing the measurement results, it was possible to determine how oleogel acts on the properties and structure of the hydrogel.
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Dielectric Properties of Vegetable Oils for Electrical Engineering
Spohner, Milan ; Mejzlík,, Miroslav (referee) ; Mentlík, Václav (referee) ; Liedermann, Karel (advisor)
The dissertation thesis deals with the analysis of prospective environmentally compatible electrical insulating fluids for electrical engineering in relation to their chemical structure. The thesis starts with the overview of the current state of the art and of the latest trends in the use of synthetic and biodegradable natural oils. In the experimental part were studied these oils: mineral oils, rapeseed oil, sunflower oils, soybean oil, methyl oleate, peanut oil, MCT oil, castor oil and other. Dielectric properties were measured using LRC meter Agilent 4980A including dielectric liquid test fixture Agilent 16452A and also by the Novocontrol Alpha-A analyzer. Electrical properties are presented in the frequency range 10 mHz – 1 MHz range in the temperature interval 253 K to 363 K. The work goes on with the study of the suitability of individual oils for lower temperature, including the impact of the chemical structure and formulation on electrical properties.
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|
Optimization of preparation and characterization of hybrid hydrogels with respect to viscoelastic and flow properties
Zhurauliova, Darya ; Kalina, Michal (referee) ; Smilek, Jiří (advisor)
This bachelor thesis focuses on the study of hybrid hydrogels that combine the properties of the hydrogel system together with oleogels, which is a gel on the base of oil. The aim of the thesis is to carry out a study of the current state of the solved issue on the topic of preparation of hybrid hydrogels, on this basis to design and optimize the appropriate procedure of preparation and in the form of viscoelastic measurements to perform the basic reological characterization of the prepared systems. A system based on sodium alginate dissolved in deionized water and meshed with calcium chloride solution was chosen as a suitable hydrogel system, and a system based on beeswax dissolved in sunflower oil was chosen as oleogel. Sodium alginate has been chosen because it is used as a thickener, emulsifier, stabilizer or gelling agent in the creams and preparation of pharmaceutical forms. By mixing hydrogels and oleogels of different proportions, a hydrogel/oleogel system, also called bigel, was created, the properties of which were tested in terms of flow and viscoelastic properties. In the practical part, amplitude, frequency and flow tests of both the hydrogel itself and the hybrid hydrogel with a ratio of 50:50 (hydrogel vs. oleogel) were measured. These tests provided information on gel preparations, i.e. what is their character, what are the mechanical properties and how it depends on the amplitude of deformation. By comparing the measurement results, it was possible to determine how oleogel acts on the properties and structure of the hydrogel.
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The use of near-infrared spectroscopy for characterisation of raw material for sunflower oil production
Vystavělová, Petra ; Vránová, Dana (referee) ; Pudilová, Ludmila (advisor)
This diploma thesis provides summary information about using of near infrared spectroscopy for monitoring of high oleic acid content in sunflower seed. The calibration for high oleic sunflower seed was performed by using calibration model PLS - „Partial least squares. Gas chromatography was used as a reference method. Based on this knowledge thirty samples of high oleic sunflower seeds were measured and evaluated on this calibration. The last part of diploma thesis consist of comparison of oleic acid results measured by near infrared spectroscopy and gas chromatography used as reference method, and discussion about the measurement accuracy and evaluation of suitability of using these methods.
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|
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Analysis of the rheological properties of vegetable oils and their components
Divílek, Petr ; Rozsívalová, Zdenka (referee) ; Frk, Martin (advisor)
This Master’s thesis is dealing with theoretical analysis of vegetable, mineral oils and synthetic fluids, and with measuring of density and viscosity of selected samples of electric insulating fluids. The main part of the thesis is focused on vegetable oils and their elements called fatty acids. Those are more detail described in separate capitols. In those capitols is described their utilization in engineering practice with focus on energetics, where vegetable oils are used in larger scale. In experimental part of the work is measurement of density and dynamic viscosity. Viscosity was measured on two different machines, first the Hoppler viscometer and on vibrating viscometer. Results of these measurement are evaluated in tables and graphs.
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