Cestode Parasites of Birds of Suborder Charadrii from Syvash Lake, Ukraine

Twelve birds species of the suborder Charadrii of the families Charadriidae, Recurvirostridae, Scolopacidae, Glareolidae were examined at Syvash Lake (Ukraine) in spring 2011. Cestodes were found in 82.1 % of examined birds. Seventeen cestode species of 6 families were found. Aploparaksis octacantha from Calidris alpinа and Echinocotyloides dubininae from C. ferruginea are new geographical records for the first time in Ukraine. Glareola pratincola is a new host record for Nadejdolepis paranitidulans. Cestodes of the genus Microsomacanthus were found in waders apparently due to the infection (2.8 %) in their intermediate hosts, gammarid crustaceans.Весной 2011 г. на озере Сиваш (Украина) было исследовано 12 видов куликов подотряда Charadrii, семейств Charadriidae, Recurvirostridae, Scolopacidae, Glareolidae. У 82.1 % исследованных птиц найдены цестоды. Обнаружено 17 видов цестод 6 семейств. Aploparaksis octacantha от C. alpinа и Echinocotyloides dubininae от C. ferruginea впервые зарегистрированы в Украине. Для Nadejdolepis paranitidulans указан новый хозяин — Glareola pratincola. У куликов также найдены представители рода Microsomacanthus, что связано с заражённостью (2,8 %) промежуточных хозяев, гаммарусов

Pokročilá spektroskopická charakterizace souborů kvantových teček

Title: Advanced spectroscopic characterization of quantum dot ensembles Author: Michael Greben Department: Department of Chemical Physics and Optics Supervisor of the doctoral thesis: Prof. Jan Valenta, Ph.D. Abstract: Semiconductor quantum dots (QDs) are small crystallites whose sizes (of the order of nm) cause spatial confinement of carriers in all 3 dimensions. As result, QDs often reveal very different physical properties in comparison with their bulk counterparts. From the optical point of view, the broadening of bandgap with QD-size shrinking is particularly interesting. It is a purely quantum mechanical effect that results from quantum confinement (QC), i.e. dimensional limitations of excitons. A strong spatial confinement leads to a relaxation of momentum (Heisenberg uncertainty principle), consequently, larger overlap of the wave-functions of carriers results in significant increase of probability of radiative recombination. Therefore ensembles of QDs are promising candidates for new generations of photonic and photovoltaic devices. This PhD thesis is primary focused on detailed spectroscopic characterization of ensembles of direct (PbS) and indirect (Si) semiconductor QDs in both colloidal (toluene) and matrix-embedded (oxide or oxinitrides multilayers) forms. The oleic- acid capped PbS QDs were...Název práce: Pokročilá spektroskopická charakterizace souborů kvantových teček Autor: Michael Greben Školící pracoviště: Katedra chemické fyziky a optiky Školitel: Prof. RNDr. Jan Valenta, Ph.D. Abstrakt: Polovodičové kvantové tečky (KT) jsou několik nanometrů velké krystality, v nichž je pohyb vybuzených elektronů a děr omezen ve všech třech rozměrech, což vede ke kvantování jejich energie - tzv. kvantový rozměrový jev (KRJ). V důsledku toho, KT často jeví velmi odlišné fyzikální vlastnosti ve srovnání s jejich objemovými protějšky. Z optického hlediska je zvláště zajímavé rozšířování zakázaného pásu s klesající velikostí KT. Velká lokalizace částice v prostoru také vede k "rozmazání" hybnosti (Heisenbergův princip neurčitosti) a způsobí větší překrytí vlnových funkcí nosičů, a tedy významné zvýšení pravděpodobnosti zářivé rekombinace (v případě polovodičů s nepřímým zakázaným pásem). To dělá z povodičových KT slibné kandidáty pro nové generace fotonických a fotovoltaických součástek. Tato disertační práce je primárně zaměřena na podrobnou spektroskopickou charakterizaci souborů přímých (PbS) a nepřímých (Si) polovodičových KT, a to jak v koloidní formě (toluen), tak zabudované v matrici (vícevrstvé oxidy a oxinitridy). PbS KT pasivované kyselinou olejovou byly získány od komerčních dodavatelů, Si KT...Department of Chemical Physics and OpticsKatedra chemické fyziky a optikyFaculty of Mathematics and PhysicsMatematicko-fyzikální fakult

Grass cellulose as cost-effective energy source for biological sulphate removal

Acid mine drainage (AMD) needs to be treated before it is discharged to water courses. The biological sulphate removal technology can be applied for the removal of salinity (sulphate), acidity and metals, the main pollutants in AMD. The aim of this study was to demonstrate that sulphate removal can be achieved using the fermentation products of grass-cellulose as cost- effective carbon and energy sources. Two studies were conducted. In the first study (an experimental period of 32 d) two stirred anaerobic batch reactors with a volume of 2.5 ℓ each were operated at 37 to 39 ˚C and at a pH of 6.7 to 6.9. Both reactors contained grass cuttings, sulphate-reducing bacteria and rumen fluid. The test reactor contained sulphate-rich water and the control reactor tap water. The results from this study indicated that grass cellulose could serve as an energy source for biological sulphate removal. In the second experiment a 20 ℓ continuously fed one-stage reactor containing grass cuttings, rumen fluid and immobilised sulphate-reducing bacteria, was fed synthetic sulphate-rich feed water. The results showed that sustained sulphate removal could be achieved when operating this reactor. The butyric and propionic acids formed were mainly utilised as the electron donors for the sulphate reduction, which resulted in increased levels of acetic acid. A clear relationship existed between the rate of sulphate reduction and the COD/VFA concentration in the reactors. It was concluded that sustained sulphate removal was achieved operating the continuously fed reactor using grass-cellulose as the carbon and energy sources.Keywords: cellulose, fermentation, grass cuttings, rumen microbes, sulphate, VF

Modification and Characterization of Potential Bioelectronic Interfaces

In this dissertation, planar biocompatible dielectric and metal surfaces, modified with self-assembling organic monolayers and functionalized gold nanoparticles are studied. In the field of bioelectronics, adhesion and guiding of cells (especially neurons) on a substrate is of great importance, and withal a hard challenge. Optimization and engineering of properties of a carrier (biocompatible inorganic substrates) can potentially improve the contact between cells and substrates, increase the survival rate of cells and improve the signal transfer. Nowadays it is clear, that the cell interacts with outer world via proteins, which, following the physical approach, interact with the surface via electrostatic interaction. Unfortunately, in aqueous environment, proteins responsible for the cell adhesion as well as most inorganic substrates bear a net negative surface charge that leads to an electrostatic repulsion and, consequently, impairs adhesion. The use of functionalized organic molecules or inorganic nanoparticles allows engineering the surface properties of various materials in order to facilitate the cell adhesion. Therefore, in this dissertation, planar biocompatible dielectric and metal surfaces modified subsequently with organic molecules, and functionalized gold nanoparticles are characterized via an optimized surface potential analysis in combination with other supporting techniques (e.g. ellipsometry, wetting angle and SEM). Additionally, a setup for the deposition of molecular monolayers, including in-situ cleaning and activation, accompanied by in-situ electronic analysis via capacitive and microwave measurements is developed and tested. During this work, the deposition and functionalization of AuNPs as well as a streaming potential/streaming current experiment for the analysis of the surface potential of the substrates and layers were improved and optimized. Using especially the time- and pH-dependent analysis of the zeta potential, we can analyze the various types of ‘simple’ (e.g. various biocompatible substrates, metallic layers, graphene) and complex (e.g. molecular monolayers, functionalized gold nanoparticles) interfaces and identify possible candidates for the modification of a given surface with respect to their surface potential (e.g. organic molecules with different functionalization). Finally, our extended analysis allows us to determine the stability of a given surface and monitor the change of the surface potential due to the engineering of a surface (e.g. via deposition of gold nanoparticles)