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Changes of physical-chemical parameters of surface water in context with hydrological extremes. Application in the Rolava River catchment.
Šajnarová, Lucie ; Matoušková, Milada (advisor) ; Havlíková, Petra (referee)
6 Abstract The diploma thesis deals with changes in the physico-chemical parameters of surface flows in response to extremes, especially increased flows due to higher precipitation totals or melting snow. The basin of the upper Rolava with peat bogs in the basin and minimal anthropogenic influence was used. The main goal of the work was the analysis of the behavior of electrical conductivity during events when there was an increase in flow rates and the categorization of individual events according to this behavior. Furthermore, the influence of the pre-condition of the watershed on the events and the subsequent behavior of the electrical conductivity was also investigated. The 10-minute electrical conductivity and flow data from the automatic stations of the ecohydrology team of the Faculty of Science, UK, or ČHMÚ were used. Among the methods are data homogenization, construction of hysteresis loops, categorization of loops, calculation of indices for hysteresis loops and PCA analysis for the pre-condition of the watershed. In most cases, a reverse relationship of electrical conductivity behavior was observed during these events, the most common types of electrical conductivity behavior during flow increases include a slow decrease in conductivity with minimum values after the peak of flow (in light...
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Laser spectroscopy of materials for spintronics
Brajer, Martin ; Němec, Petr (advisor)
In these diploma thesis magnetically ordered materials are studied with the prospect of their application in spintronics. Specifically, we investigated metallic alloy FeRh, which undergoes a magnetic phase transition from antife- romagnetic phase to feromagnetic one around 100◦ C. This phenomenon can be readily used in memory devices. Laser spectroscopy is used as a nondestructive method without need of any electrical contacts. Magnetic properties of FeRh are studied by magnetooptical effects including quadratic magnetic linear dichroism. The measured polarization rotations are of the order of miliradians, therefore, the detection is realized by an optical bridge. At first, we concentrated on discrimina- ting of various magnetooptical effects from each other. The second part is focused on the phase transition induced by different means. Firstly, by heating the whole sample, secondly by illuminating the sample locally by continuous laser.
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Laser spectroscopy of materials for spintronics
Brajer, Martin ; Němec, Petr (advisor)
In these diploma thesis magnetically ordered materials are studied with the prospect of their application in spintronics. Specifically, we investigated metallic alloy FeRh, which undergoes a magnetic phase transition from antife- romagnetic phase to feromagnetic one around 100◦ C. This phenomenon can be readily used in memory devices. Laser spectroscopy is used as a nondestructive method without need of any electrical contacts. Magnetic properties of FeRh are studied by magnetooptical effects including quadratic magnetic linear dichroism. The measured polarization rotations are of the order of miliradians, therefore, the detection is realized by an optical bridge. At first, we concentrated on discrimina- ting of various magnetooptical effects from each other. The second part is focused on the phase transition induced by different means. Firstly, by heating the whole sample, secondly by illuminating the sample locally by continuous laser.
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Laser spectroscopy of materials for spintronics
Brajer, Martin ; Němec, Petr (advisor) ; Jakubisová, Eva (referee)
In these diploma thesis magnetically ordered materials are studied with the prospect of their application in spintronics. Specifically, we investigated metallic alloy FeRh, which undergoes a magnetic phase transition from antife- romagnetic phase to feromagnetic one around 100◦ C. This phenomenon can be readily used in memory devices. Laser spectroscopy is used as a nondestructive method without need of any electrical contacts. Magnetic properties of FeRh are studied by magnetooptical effects including quadratic magnetic linear dichroism. The measured polarization rotations are of the order of miliradians, therefore, the detection is realized by an optical bridge. At first, we concentrated on discrimina- ting of various magnetooptical effects from each other. The second part is focused on the phase transition induced by different means. Firstly, by heating the whole sample, secondly by illuminating the sample locally by continuous laser.
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