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Characterization of peat
Freithová, Štěpánka ; Mikšík, František (referee) ; Kotlík, Josef (advisor)
Peatlands are considered to be valuable ecosystems on the Planet and play an important role in many processes globally likewise and in the landscape. They are important for maintaining a global biodiversity, play an important role in landscape hydrology and can be a source of drinking water. They can help minimize floods and contribute to climate change mitigation. The peat bogs are one of the largest terrestrial carbon reservoirs. They have been storing carbon for centuries. Many of peat functions are affected due to human activities. It can result into release of greenhouse gases into atmosphere and the excretion of organic carbon into watercourses. The subject of the thesis is understanding of the mechanisms of water binding in peat and exploring possible dependencies within the depth profile of the peatlands using thermal analytical methods, more preciously using thermogravimetry (TG) and differential scanning calorimetry (DSC). The stability of water molecule bridge (WaMB) was investigated. It was found out that the minimum temperature required for WaMB abatement decrease and the whole structure becomes less stable with increasing peat layer depth. Water release processes were evaluated with the meaning of the TGA measurements. A decreasing trend in the degradation of thermolabile substances and an increasing trend in thermostable substances within the peat profile were observed.
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Properties and utilization of Sea-buckthorn oil
Trávníčková, Eva ; Kučerík, Jiří (referee) ; Zemanová, Jana (advisor)
This bachelor thesis deals with the properties and utilization of sea buckthorn (Hippophae rhamnoides) and sea buckthorn oil. Sea Buckthorn oil contains wide range of substances important for health, for example vitamin E, vitamin A, carotenoids, flavonoids, sterols and essential unsaturated fatty acids. Sea Buckthorn oil is commonly used in treatment of cardiovascular disease and cancer. Its antioxidant properties are of great importance; it has UV-blocking activity and anti-aging effects. It accelerates healing of injuries and burns. In this work there are methods of thermal analysis such as differential scanning calorimetry (DSC) and thermogravimetry (TG) are employed and described. These methods were used to study thermal and thermo-oxidative stability and physical-chemical behavior of the sea buckthorn oil. DSC method was used in the slow and rapid cooling regime which revealed the sensitivity of oil to the thermal history and also the fact that the resulting endotherms do not correspond to melting temperatures of sea buckthorn oil pure components. Application of TG method revealed that oxygen has only minor effect on thermo-oxidative stability; degradation of sea buckthorn oil is caused mainly by the elevated temperature.
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Characterization of peat
Freithová, Štěpánka ; Mikšík, František (referee) ; Kotlík, Josef (advisor)
Peatlands are considered to be valuable ecosystems on the Planet and play an important role in many processes globally likewise and in the landscape. They are important for maintaining a global biodiversity, play an important role in landscape hydrology and can be a source of drinking water. They can help minimize floods and contribute to climate change mitigation. The peat bogs are one of the largest terrestrial carbon reservoirs. They have been storing carbon for centuries. Many of peat functions are affected due to human activities. It can result into release of greenhouse gases into atmosphere and the excretion of organic carbon into watercourses. The subject of the thesis is understanding of the mechanisms of water binding in peat and exploring possible dependencies within the depth profile of the peatlands using thermal analytical methods, more preciously using thermogravimetry (TG) and differential scanning calorimetry (DSC). The stability of water molecule bridge (WaMB) was investigated. It was found out that the minimum temperature required for WaMB abatement decrease and the whole structure becomes less stable with increasing peat layer depth. Water release processes were evaluated with the meaning of the TGA measurements. A decreasing trend in the degradation of thermolabile substances and an increasing trend in thermostable substances within the peat profile were observed.
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Properties and utilization of Sea-buckthorn oil
Trávníčková, Eva ; Kučerík, Jiří (referee) ; Zemanová, Jana (advisor)
This bachelor thesis deals with the properties and utilization of sea buckthorn (Hippophae rhamnoides) and sea buckthorn oil. Sea Buckthorn oil contains wide range of substances important for health, for example vitamin E, vitamin A, carotenoids, flavonoids, sterols and essential unsaturated fatty acids. Sea Buckthorn oil is commonly used in treatment of cardiovascular disease and cancer. Its antioxidant properties are of great importance; it has UV-blocking activity and anti-aging effects. It accelerates healing of injuries and burns. In this work there are methods of thermal analysis such as differential scanning calorimetry (DSC) and thermogravimetry (TG) are employed and described. These methods were used to study thermal and thermo-oxidative stability and physical-chemical behavior of the sea buckthorn oil. DSC method was used in the slow and rapid cooling regime which revealed the sensitivity of oil to the thermal history and also the fact that the resulting endotherms do not correspond to melting temperatures of sea buckthorn oil pure components. Application of TG method revealed that oxygen has only minor effect on thermo-oxidative stability; degradation of sea buckthorn oil is caused mainly by the elevated temperature.
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