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Study of sensoric properties of organic semiconductors
Saska, Pavel ; Šedina, Martin (referee) ; Salyk, Ota (advisor)
Compounds based on diketopyrrolopyrrole are organic pigments that behave as semi-conductors. Their analogues with pyridyl side group are due to their sensitivity to hydrogen potentially useful as hydrogen sensors. The aim of this work was to examine properties of sensors with an active layer of diketopyrollopyrolle derivatives. The sensors were tested on an apparatus built for this purpose at FCH VUT in Brno. More specifically, changes to conductivity of these sensors in the presence of hydrogen under various conditions were studied.
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Study of properties of electrolytically modified NaCl solutions.
Brázda, Lukáš ; Mika, Otakar Jiří (referee) ; Mašek, Ivan (advisor)
This work concentrates on the study of properties of NaCl solutions, prepared by electrolysis and their using for disinfection of water. Then it is focused on reporting on possibality for corrosin of metals, whice are used in water distribution. For study was used 0,25 mol/l, 0,1 mol/l, 0,05 mol/l NaCl solutions and input direct-current voltage for electrolysis was 6V a 12 V. During the electrolysis pH and conducitivity were measured. After the end of electrolysis free active chlorine and chlorides were determined on the time. For electrolysis was used diaphragm.
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Puccinelia distans and Digitaria sanguinalis as a phenomenon of road verges
LAXOVÁ, Lenka
The main subject of this bachelor thesis is establishment the main phenological phases of two grass species Puccinelia distans and Digitaria sanguinalis, which occur in vegetation bands along the roads. It also deals with change of their dominance during one with higher soil salinity along roads near the town České Budějovice. The soil conductivity on road verges was measured, too. Collected information and field data from certain localities were proccesed into tables, diagrams and summary resuls. The tendency in phenological phases exchange confirmed propagation and existence of theese two species on joint area during thge spring and summer seasons. It shows an adaptation of both plants into salt contaminated soil. Soil conductivity shows fluctuating trend in soil salinity during the year on road verges
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Hydrochemistry of underground waters in Chynov cave
LUTZ, Vojtěch
This thesis deals with the evaluation of hydrochemical characteristics of groundwater (dripping water) in The Chýnov Cave and the subsequent statistical processing of the results. There were followed three sampling points, which were irregularly distributed in the cave system. Bicarbonates occured as the dominant anions in the dripping water. The dominant cation was calcium. Water can therefore be classified as bicarbonate - calcium. This corresponds with the expectations for The Chýnov cave location. There were also detected enhanced concentrations of nitrates and sulphates at sampling site Štola - this has long-term character and influences the quality of the underground stream of The Chýnov cave, which is directly connected to spring "Rutický" (source of drinking water for the town of Chýnov). Although a protective zone is declared over the whole territory of Rutice water resources, there is increased amount of nitrates and sulphates which probably has anthropogenic character and it comes from applied fertilizer and mineralization processes in arable land in the close surrounding of the National Natural Monument: The Chýnov cave.
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Evaluation of quality and the renewal of surface water in the area affected by surface coal mining.
VLÁŠEK, Ondřej
The aim of the study was to evaluate the parameters of quality and renewal of surface water in the area affected by surface brown-coal mining. Selected streams were monitored on the Great pokrusnohorska dump, and streams unaffected by dumps. Values of pH, conductivity, alkalinity, oxygen saturation and temperature were measured, and quantitative and qualitative samples of macrozoobethos were taken too. The dump?s water are characterized by high concentrations of dissolved solids and alkalinity. Species diverzity of these waters is lower and is affected not only by chemical compositon of the water, but also by the character of the bottom substrate.
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Identification of point sources of surface water pollution and their quantification in selected catchments in the Šumava Mountains.
TOMKOVÁ, Zdeňka
An evaluation of chemical parameters of surface waters proceed in the three small basin areas in Šumava Mountains, in the area of Svatý Tomáš highlands, during the year 2009: Bukový (woods), Mlýnský (semi{--}intensive and drained pasture, part of Pasečná village) and Horský stream (wetlands, woods, mowed meadows, a part of Svatý Tomáš village). The aim was to chart the three main periods during the year. The spring sampling (the 12th May) should illustrate the beginning of growing season with higher water flow rates. The summer sampling (the 21st July) is the period on the top of growing and touristic season, seasonal works in wood and especially in agriculture (grazing and mowing meadows). The last sampling (the 21st October) represents the season at the end of growing season, generally with the lowest flow rates in the stream, the end of touristic season and the end of full{--}area grazing. Already during the field research, involving the water sampling and conductivity measurement, there were some inflows with increased concentrations of dissolved solids found. Whereas in Bukový stream, as has been assumed, these inflows didn´t more or less occur, in Horský stream they had, relatively surprisingly but significantly, appeared immediately in headwater area. The elevated concentrations of dissolved solids occurred in Mlýnský stream in the whole area of basin, as has been assumed regarding to drainage and full{--}area grazing. One year monitoring proved the advantage of water quality evaluation using simple measurement of conductivity in field. High water conductivity in field was subsequently confirmed by laboratory analysis of selected ions. On the basis of identification of point sources of pollution, the recommendation improving present condition was suggested.
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Polyaniline: conducting polymer
Stejskal, Jaroslav
The contribution presents the fundamental properties of conducting polymers, which are illustrated on an example of polyaniline. After historical background, the preparation of polyaniline is described. The attention has been paid to the nanostructures produced by conducting polymers, viz. to polyaniline nanotubes. Finally, the applications of conducting polymers are discussed.
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