8 research outputs found

    Fenton-like oxidation of an azo dye using mesoporous Fe/TiO2 catalysts prepared by a microwave-assisted hydrothermal process

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    Fe-doped TiO2 photocatalysts with different contents of Fe (0.5, 1.6, 3.4 and 6.4 %) were synthesized by a microwave-hydrothermal method and characterized by X-ray diffraction analysis, N-2 physisorption at 77 K and UV-Vis spectrometry. The characterization showed that the Fe ions were highly dispersed in the TiO2 lattice. It was found that all the synthesized catalysts had a mesoporous structure and that Fe-doping increased the BET surface area. The UV-Vis study showed that the absorption spectra were shifted to longer wavelengths (red shift) with increasing dopant concentration. The photocatalytic activity of the samples was evaluated by the decolorization of the textile dye Reactive Blue 52 (RB) in aqueous solutions under sun-like radiation in the presence of H2O2 (a heterogeneous photo-Fenton process). The photocatalyst with 3.4 % Fe was found to be the most efficient in the presence of H2O2. The effect of the initial pH of the dye solution was assessed and dissolution of iron ions was studied as a function of pH value. It was concluded that decolorization was more favorable in acidic pH, and that at pH values gt 4, the release of Fe ions into the solution was negligible. Photocatalytic degradation of 4-chlorophenol (4-CP) was investigated under the optimal conditions and it was shown that the catalyst was capable of degrading colorless pollutants

    The structural, electrical and optical properties of spark plasma sintered BaSn1-xSbxO3 ceramics

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    Antimony doped barium-stannate dense ceramic materials were synthesized using spark plasma sintering technique out of mechanically activated precursor powders. The influence of various Sb concentrations (x =0.00 – 0.10) on properties of BaSn1-xSbxO3 ceramics was investigated. Relative densities of prepared samples were in the range of (79–96) %. TEM analysis revealed the presence of many dislocations in undoped BaSnO3, and their significant reduction upon doping with Sb. All samples except BaSn0.92Sb0.08O3 exhibit non-linear I-U characteristic, typical for semiconductors with potential barrier at grain boundaries. Low angle grain boundaries found only in BaSn0.92Sb0.08O3 caused the loss of potential barrier at grain boundaries which was confirmed by AC impedance spectroscopy measurements. Consequently, BaSn0.92Sb0.08O3 showed the lowest electrical resistivity and linear I-U characteristic. UV–vis analysis confirmed the increasing of band gap (Burstein–Moss shift) values in all doped samples.This is the peer-reviewed version of the manuscript: Vukasinovic J, Pocuca-Nesic M, Golic DL, Ribic V, Brankovic Z, Savic SM, Dapcevic A, Bernik S, Podlogar M, Kocen M, Rapljenovic Z, Ivek T, Lazovic V, Dojcinovic B, Brankovic G, The structural, electrical and optical properties of spark plasma sintered BaSn1-xSbxO3 ceramics, Journal of the European Ceramic Society (2020), 40, 15, 5566-5575, doi: [https://doi.org/10.1016/j.jeurceramsoc.2020.06.062]The published version: [http://cer.ihtm.bg.ac.rs/handle/123456789/3628

    Translation as Border-Crossing: Virginia Woolf’s Case

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    Ce texte se concentre sur le « cas de Virginia Woolf », c’est-à-dire sur la manière dont la traduction de son œuvre se rapporte à un border-crossing théorique, notamment dans le contexte de l’arrivée des théories féministes dans les pays de l’Europe de l’Est. La traduction est pensée principalement comme inspiration, concept proche de celui d’interprétation et apparemment sans limites. L’article comprend trois parties, les deux premières explorant les limites de la traduction comme inspiration à partir des lectures de Woolf en Serbie, tandis que la troisième partie porte sur les relations modernes entre l’Est et l’Ouest et la traduction comme border-crossing, dans la littérature mais aussi dans la vie.This text focuses on the "case of Virginia Woolf", that is, how the translation of her work relates to theoretical border-crossing, especially within the context of the arrival of feminist theory in the countries of Eastern Europe. The idea of translation is seen primarily as inspiration, which is both close enough to interpretation and seemingly without limits. The text is structured in three parts, of which the first two explore the limits of translation as inspiring readings of Woolf in Serbia, while the third part covers the East-West modernist relation and translation as border-crossing in literature and also in life.Este artículo se centra en el “caso de Virgina Woolf”, es decir, en cómo la traducción de su obra se relaciona con el border-crossing teórico, especialmente en el contexto de la llegada de la teoría feminista a los países de Europa del este. La idea de la traducción es considerada principalmente como inspiración, la cual se halla cercana a la inspiración y, en apariencia, carece de límites. El artículo consiste en tres partes, la de las cuales las dos primeras exploran los límites de la traducción como inspiración en las lecturas de Woolf en Serbia, mientras que la tercera se ocupa de la relación modernista entre el Este y el Oeste y de la traducción como border-crossing, tanto en la literatura como en la vida

    Предавати феминистичке књижевне теорије

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    In this text I summarize my experience in teaching feminist literary theory. The basic idea is that teaching literature and literary theory, especially feminist literary theory, is a process of personal development. This is why I compare my present experience with the text from 12 years ago, describing the process of moving from impersonal to personal approach in teaching.У тексту резимирам искуство у предавању феминистичке књижевне теорије. Основна идеја јесте да је, осим што је теорија аутобиографија, писање и говор о себи, и процес предавања књижевне теорије лични процес саморазвоја. Упоређујући текст написан пре 12 година и садашњи однос према питањима јавног и приватног, имперсоналног и личног у књижевности, закључујем да је лично искуство битан чинилац одабира не само теоријског него и методолошког приступа. Нагласак на личном искуству је у самим основама феминистичке критике, али управо се тај њен аспект не може научити, већ се мора доживети да би се разумео. У теоријском смислу, ту је реч о енграмском доживљају књижевног текста – сусрету дубоког, више не и нужно свесног личног доживљаја и његовог књижевног корелатива

    Decolorization of reactive textile dyes using water falling film dielectric barrier discharge

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    Decolorization of reactive textile dyes Reactive Black 5, Reactive Blue 52, Reactive Yellow 125 and Reactive Green 15 was studied using advanced oxidation processes (AOPs) in a non-thermal plasma reactor, based on coaxial water falling film dielectric barrier discharge (DBD). Used initial dye concentrations in the solution were 40.0 and 80.0 mg/L. The effects of different initial pH of dye solutions, and addition of homogeneous catalysts (H2O2, Fe2+ and Cu2+) on the decolorization during subsequent recirculation of dye solution through the DBD reactor, i.e. applied energy density (45-315 kJ/L) were studied. Influence of residence time was investigated over a period of 24 h. Change of pH values and effect of pH adjustments of dye solution after each recirculation on the decolorization was also tested. It was found that the initial pH of dye solutions and pH adjustments of dye solution after each recirculation did not influence the decolorization. The most effective decolorization of 97% was obtained with addition of 10 mM H2O2 in a system of 80.0 mg/L Reactive Black 5 with applied energy density of 45 kJ/L, after residence time of 24 h from plasma treatment. Toxicity was evaluated using the brine shrimp Artemia sauna as a test organism

    Preparation, characterization and photocatalytic activity of lanthanum and vanadium co-doped mesoporous TiO2 for azo-dye degradation

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    Titanium dioxide photocatalysts co-doped with lanthanum and vanadium were prepared by a facile microwave-assisted hydrothermal method and characterized by XRD, SEM, N-2 physisorption at 77 K and DRS. The characterization showed that co-doped TiO2 samples have a high degree of crystallinity and existence of fully anatase phase. It was found that all the synthesized catalysts have the mesoporous structure. The co-doped TiO2 samples have larger BET surface areas and the mesopores volume than pure TiO2 and La doped samples. The vanadium co-doping contributes to the extension of absorption into the visible region. The photocatalytic activity of the samples was evaluated by the decolorization of textile dye Reactive Blue 52 in aqueous solutions under sun-like radiation. Compared with La singly doped TiO2, the co-doped catalysts showed an important improvement of photoactivity. The photocatalyst with 2% (w/w) La and 0.02% (w/w) V appeared to be the most photoactive. Optimal catalyst loading and the kinetics of degradation were also studied. Demonstrating higher photodegradation efficiency for RB than commercially available TiO2 Evonik P25, easy separation from suspension by spontaneous sedimentation and reusability of the catalyst, make this photocatalyst suitable for wastewater treatment.Peer-reviewed manuscript: [http://cherry.chem.bg.ac.rs/handle/123456789/3514
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