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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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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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Dielectric Properties Of Natural Oils From Different Oilseeds
Spohner, Milan
This paper describes analysis of perspective, ecological and environmentally-friendly electrical insulating liquids for electrical engineering. In the experimental part, dielectric properties of the most common vegetable oils were analyzed and compared with frequently used noninhibited mineral oil (TrafoN): soybean oil, sunflower oil, rapeseed oil, peanut oil and two types of olive oils (extra virgen and pomace). Dielectric properties were measured using the high-resolution Novocontrol Alpha-A Frequency Analyzer in the frequency range 1 Hz – 1 MHz in the temperature interval 243 K – 363 K.
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Impact of alternative feed on growth, yield and sensory evaluation of flesh of salmonids.
PFLUG, Róbert
The bachelor thesis evaluates the impact of alternative feed on growth, yield and sensory evaluation of flesh of salmonids. The technology "finishing feeding" and its impact on these indicators was evaluated by a feeding test conducted in trout farm in Annin (Klatovské rybářství a.s.). The experimental species was brook trout (Salvelinus fontinalis L.) with average weight of 156 ? 4,91 g. The test was carried out for 135 days and there were 2 diets. Diet A (rapeseed oil, RO) or B (fish oil, FO) or their combination (45RO:90FO; 90RO:45FO). Each treatment was carried out in duplicate. After 45, 90 days and at the end of the test, evaluation of production characteristics, yield and sensory evulation of fish muscle was carried out. Fish oil replacement by rapeseed oil had no effects on fish survival, growth, feed conversion and yield. After 45 days (first sensory evoluation), flesh of fish fed diet with rapeseed oil was better senzory evaluated than fish fed fish oil diet. However, the later sensory evaluation didn?t show any statistical differences among the treatments.
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Effect of alternative feed on content of omega 3 fatty acids in fish muscles
KREJSA, Jakub
The aim of my bachelor thesis was to evaluate the effect of fish oil substitution for rapeseed oil in the feed on the fat content and fatty acid composition in the flesh of Brook trout (Salvelinus fontinalis) in the finishing feeding technology. The experiment was conducted in 2012 for the period of 135 days. The individuals of Brook trout were divided into four groups. The first two groups were fed with the feed containing only rapeseed or fish oil. The feeding of the remaining two groups was divided into two phases. In the first phase the fish oil was partly replaced by the rapeseed oil. In the second phase the fish oil was replaced by the feed which contained fish oil only. It was proved that a half replacement of the fish oil with the rapeseed oil does not influence the content of fat in the flesh of Brook trout. We observed that the fish had the higher content of MUFA and n-6 PUFA and lower content of n-3 PUFA, DHA, EPA and n-3/n-6 with increasing period where the feed with rapeseed oil was served. Following application of the finishing feeding technology with the use of feed with fish oil had the opposite effects. Furthermore, the dilution model was proved to be highly reliable for the prediction of the fatty acids composition. Based on these findings, it is possible to predict changes of fatty acid composition in the flesh of Brook trout as well as to predict how long is needed to apply finishing feeding to reach required content of EPA+DHA or n-3 HUFA.
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