Stabilizing Agents for Calibration in the Determination of Mercury Using Solid Sampling Electrothermal Atomic Absorption Spectrometry

Tetramethylene dithiocarbamate (TMDTC), diethyldithiocarbamate (DEDTC), and thiourea were investigated as stabilizing agents for calibration purposes in the determination of mercury using solid sampling electrothermal atomic absorption spectrometry (SS-ETAAS). These agents were used for complexation of mercury in calibration solutions and its thermal stabilization in a solid sampling platform. The calibration solutions had the form of methyl isobutyl ketone (MIBK) extracts or MIBK-methanol solutions with the TMDTC and DEDTC chelates and aqueous solutions with thiourea complexes. The best results were obtained for MIBK-methanol solutions in the presence of 2.5 g L−1 TMDTC. The surface of graphite platforms for solid sampling was modified with palladium or rhenium by using electrodeposition from a drop of solutions. The Re modifier is preferable due to a higher lifetime of platform coating. A new SS-ETAAS procedure using the direct sampling of solid samples into a platform with an Re modified graphite surface and the calibration against MIBK-methanol solutions in the presence of TMDTC is proposed for the determination of mercury content in solid environmental samples, such as soil and plants

Accuracy testing of minor horizontal geodetic control determined by analytical aerotriangulation

Obsahem bakalářské práce je ověření kvality bodů podrobného polohového bodové pole, které bylo vybudováno v osmdesátých letech dvacátého století metodou analytické aerotriangulace v rámci tvorby základní mapy velkého měřítka (ZMVM). Doposud byly tyto body evidovány ve třídě přesnosti 4. Bodové pole bylo přeměřeno metodou RTK. Byly vypočítány charakteristiky přesnosti pro posouzení, zda tyto body splňují požadavky 4., případně také 3. třídy přesnosti. Výsledky byly po dohodě poskytnuty katastrálnímu pracovišti v Jindřichově Hradci pro další možné využití.The purpose of this bachelor’s thesis is testing quality of minor horizontal geodetic control points in chosen area in South Bohemia. The control points have been established in the eighties of twentieth century during cadastrial mapping (large scale base map). Until now, those points were recorded in the 4th accuracy class. The geodetic control was remeasured with RTK technique, then deviations were calculated. These results were reviewed and evaluated whether the points match with the 4th accuracy class or even the 3rd accuracy class. The results were submitted to the local cadastral office in Jindřichův Hradec.

Macro- and microelements in soil profile of the moss-covered area in James Ross Island, Antarctica

The study of Antarctic ecosystem provides a valuable insight into the nature development on the Earth. Biocenosis formation and colonization of land by organisms are noticeable especially in newly-deglaciated areas. In this research, soil profile development in the coastal zone of James Ross Island was investigated. The main objective was the characterisation of soil horizons. The contents of As, Ca, Cd, Co, Cr, Cu, Fe, K, Mg, Mn, Ni, P, Se and Zn were measured using ICP-MS technique. Soil parameters like organic carbon content, pH and content ofsub-63 μm fraction were also determined. Based on the results obtained, the mineral-depleted and mineral‑enriched layers in the soil profile were distinguished. With increasing depth, the shallow soil profile consisted mainly of weathered regolith. Apparently, the basic processes which are prerequisite for the development of soil ecosystem in the studied area were confirmed

Nitrate and ammonium ions contents in field minibioreactors with Antarctic freshwater autotrophs

The content of nitrate and ammonium ions in aquatic environment is an important factor in the development of microorganisms colonies especially in low-nutrient environment. In this study, field experiments using small-volume minibioreactors were performed directly on the James Ross Island in Antarctica in order to describe changes in nitrate and ammonium ions contents in the Antarctic environment The ion concentrations in minibioreactors with local freshwater autotrophs was monitored for increased eutro-phication conditions. The content of nitrogen forms was determined in water samples taken from the minibioreactors regularly. Samples were taken to the laboratory of the Johann Gregor Mendel station where nitrogen content was evaluated using ion-selective electrodes. Furthermore, the freshwater autotrophs was subjected to basic taxonomic study. Closed system of the minibioreactors allowed the monitoring of nitrogen speciation changes which take place in the environment. These changes can be attributed to both the biological activity of microorganisms and external conditions. Increased eutrophication of water did not induce a rapid development of the freshwater autotrophs

Synthesis of β-d-galactopyranoside-Presenting Glycoclusters, Investigation of Their Interactions with Pseudomonas aeruginosa Lectin A (PA-IL) and Evaluation of Their Anti-Adhesion Potential

Pseudomonas aeruginosa is an opportunistic human pathogen associated with cystic fibrosis. This bacterium produces, among other virulence factors, a soluble d-galactose-specific lectin PA-IL (LecA). PA-IL plays an important role in the adhesion to the host cells and is also cytotoxic. Therefore, this protein is an interesting therapeutic target, suitable for inhibition by carbohydrate-based compounds. In the current study, ß-d-galactopyranoside-containing tri- and tetravalent glycoclusters were synthesized. Methyl gallate and pentaerythritol equipped with propargyl groups were chosen as multivalent scffolds and the galactoclusters were built from the above-mentioned cores by coupling ethylene or tetraethylene glycol-bridges and peracetylated propargyl ß-d-galactosides using 1,3-dipolar azide-alkyne cycloaddition. The interaction between galactoside derivatives and PA-IL was investigated by several biophysical methods, including hemagglutination inhibition assay, isothermal titration calorimetry, analytical ultracentrifugation, and surface plasmon resonance. Their ability to inhibit the adhesion of P. aeruginosa to bronchial cells was determined by ex vivo assay. The newly synthesized multivalent galactoclusters proved to be significantly better ligands than simple d-galactose for lectin PA-IL and as a result, two representatives of the dendrimers were able to decrease adhesion of P. aeruginosa to bronchial cells to approximately 32% and 42%, respectively. The results may provide an opportunity to develop anti-adhesion therapy for the treatment of P. aeruginosa infection

Development and testing of device for absolute GNSS antenna calibration

Obsahem diplomové práce je ověření chodu polohovacího zařízení používaného k absolutní kalibraci GNSS antén v závislosti na velikosti zatížení nosníku, ke kterému se antény upevňují. První část práce je věnována úvodu do problematiky kalibrace GNSS antén. V další části se práce soustředí na vývoj softwarového vybavení sloužícího ke zpracování fotogrammetrického měření, které je aplikováno pro zjištění pohybových vlastností přístroje. Následující části jsou pak zaměřeny na zpracování a vyhodnocení provedeného měření. Výsledek práce je určen pro úpravu doby stání v observačním programu.The purpose of this diploma thesis is testing motion of the device for GNSS antenna calibration according to added weight to the device’s transom. First part of this thesis is devoted to introduction into GNSS antenna calibration problematics. The thesis deals further with development of the software used to process photogrammetric images that have been taken during testing measurement. The rest of the thesis is focused to process and evaluate the measurement. The result will be implemented into observation model used during calibration measurement. The period, during the device is still, will be corrected according to the result that has been obtained from the measurement.