51. Optimization of DGT technique for determination of iron species in natural water and sediments by photothermal beam deflection spectroscopyHanna Budasheva, Arne Bratkič, Dorota Korte, Mladen Franko, 2018, published scientific conference contribution abstract Keywords: beam deflection spectroscopy, diffusive gradients in thin-film technique, iron redox species, photothermal techniques, natural water, sediments Published in RUNG: 23.11.2018; Views: 3696; Downloads: 0 This document has many files! More... |
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54. Arsenic in natural waters: hydrogeochemistry characterization and toxicity effectsDoroteja Gošar, 2018, master's thesis Abstract: Arsenic contamination in natural water is a worldwide problem and a major health concern. In master thesis hydrogeochemistry and toxicity effects of natural waters rich in arsenic were studied. The main objective of the master thesis was to evaluate As pollution of the Freixeda stream and groundwater in abandoned Freixeda gold mine area in NE Portugal near Mirandela city (41.413767 N 7.103562 W) and compare it with the data from previous studies. Further on, toxicological evaluation of selected water samples was performed in the in vitro system of human cell line Caco-2.
Chemical analyses of sampled water samples with use of different modelling sofware show that groundwater have higher sulphate and bicarbonate values than surface water, which could be the reason for As desorption and higher As values in groundwater. Water-rock interaction promotes reduction and dissolution of sulphide minerals and in reductive environments dissolution of secondary Fe minerals releases adsorbed As into solution.
Toxicological testing on human cells included cytotoxicity assay, genotoxicity assay and production of reactive oxigene species (ROS). Genotoxicity was only modestly affected by a short-term exposure to As-contaminated water samples, however, higher concentrations of As in real samples lead to higher level of oxidative stress and decreased cell viability. Exposure of cells to pure As(III) solution show clear concentration dependent decrease in cell metabolism and viability, strong genotoxicity and increased ROS generation.
Considering the worldwide extent of As contamination in natural waters and ability of intestinal epithelium to reduce the potential harmful effects of As, more studies evaluating the human intestinal permeability for As should be done in the future. Keywords: Water quality, arsenic, hydrogeochemistry, toxicity, Caco-2 cell line Published in RUNG: 26.09.2018; Views: 5280; Downloads: 197 Full text (3,76 MB) |
55. Synthesis of molybdenum carbide thin films for production of hydrogen via electrochemical water splitting : M. Sc. thesisCesur Altinkaya, 2018, master's thesis Keywords: molybdenum, platinum, molybdenum carbide thin films, hydrogen evolution reaction, water splitting, electrolysis, electrochemistry, pyrolysis, thin films Published in RUNG: 30.08.2018; Views: 4819; Downloads: 0 This document has many files! More... |
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58. Absorption Spectra of Ethanol and Water Using a Photothermal Lens SpectrophotometerHumberto Cabrera, Jehan Akbar, Dorota Korte, Imrana Ashraf, Evelio E. Ramírez- Miquet, Ernesto Marin, Joseph Niemela, 2018, original scientific article Keywords: Thermal lens spectrometry, TLS, absorption of water, absorption of ethanol, vibration overtones Published in RUNG: 08.06.2018; Views: 4231; Downloads: 0 This document has many files! More... |
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60. Photoelectrochemical Water Splitting Studies with nanostructured n and p-type semiconductor electrodesSaim Emin, Matjaž Valant, 2017, published scientific conference contribution abstract (invited lecture) Abstract: Photoelectrochemical water splitting has been demonstrated as a promising way to efficiently split water. Currently, solar-to-hydrogen conversion efficiency using state-of-the-art material combinations in PEC system is in the order of 7%. Fabrication of nanostructured materials with unique morphologies and compositions is an important factor to fully utilize the possibilities in this field. We will present different strategies for the preparation of nanostructured metal oxide thin films by using electrodeposition and wet-chemistry techniques. Focus will be given on the preparation of ZnO and CuO thin films where intermediate phases like Zn(OH)8Cl2.H2O and CuX (X=Br, Cl) were electrodeposited. Wet-chemistry synthesis techniques will be also explored for the preparation of nanostructured WO3 and a-Fe2O3 thin films. Especially, the hot-pyrolysis technique for the preparation of colloidal W and Fe/Fe-oxide nanoparticles will be shown. Spin-coating of W and Fe/Fe-oxide NPs onto optically conductive substrates and subsequent heat treatment of the obtained films was found to be a convenient way for the preparation of nanostructured WO3 and a-Fe2O3 thin films. Keywords: photoelectrochemical water splitting, colloidal nanoparticles, semiconductor Published in RUNG: 24.10.2017; Views: 4378; Downloads: 0 This document has many files! More... |