Browsing Τμήμα Χημείας / Department of Chemistry by Title
Now showing items 1223-1242 of 1296
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U(VI) adsorption by biochar fiber–MnO2 composites
(2019)The removal of U(VI) by biochar fibers from aqueous solutions has been investigated prior and after MnO2 surface-deposition. The removal efficiency has been studied as a function of pH, U(VI) concentration, ionic strength, ...
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U(VI) mono-hydroxo humate complexation
(2007)The complexation of the uranyl ion with humic acid is investigated. The humic acid ligand concentration is described as the concentration of reactive humic acid molecules based on the number of humic acid molecules, taking ...
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Understanding the synergistic catalytic effect between la2O 3 and CaO for the CH4 Lean De-NOx reaction: Kinetic and mechanistic studies
(2005)Doping of La2O3 crystallites with Ca2+ ions significantly enhances the intrinsic rate of NO reduction by CH4 in the presence of 5% O2 at 550°C compared to pure La 2O3 and CaO solids, while the opposite is true after doping ...
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Unexpected formation, X-ray structure, and characterization of the triangular [Ti3O(OMe)6(σ5-C 5H5)3](I3) complex from hydrolysis and methanolysis of [Ti(σ5-C5H5) 2I2]
(2011)A convenient route has been developed for the formation of [Ti IV3O(OMe)6(σ5-C 5H5)3](I3) (2) involving methanolysis (and possibly hydrolysis) of species derived from titanocene diiodide, [TiIV(σ5-C5H5) 2I2] (1), under ...
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Unexpected reduction of vanadium(IV) to vanadium(III) in the presence of the chelate ligands 2,2′-bipyridine (bpy) and 1,8-hydroxyquinoline (Hquin)
(2001)The structures, NMR spectra and electrochemical properties of the vanadium(III) compounds, cis-[VIIICl2-(acac)(bpy)] and [VIII(quin)3]·2CH3OH, formed from [VIVCl2(acac)2]·0.25CH2Cl 2 (Hacac = pentane-2,4-dione) and ...
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An unexpected stereoisomerism in enantiomerically pure trisadducts of C60 with an inherently chiral trans-3,trans-3,trans-3 addition pattern
(2014)We have synthesized and isolated two C2-symmetric enantiomerically pure trisadducts of C60 with an inherently chiral trans-3,trans-3,trans-3 addition pattern with the aid of an enantiopure cyclo-tris-malonate tether. An ...
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Unravelling excited state dynamics of a single stranded DNA-Assembled Conjugated Polyelectrolyte
(American Chemical Society, 2023-10-26)Conformational templating of conjugated polyelectrolytes with single-stranded DNAs (ssDNAs) has the prospect of tailoring excited state dynamics for specific optoelectronic applications. We use ultrafast time-resolved ...
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An unusual photo-induced conformational polymorphism: A crystallographic study of bis(p-methoxy)-trans-stilbene
(1984)A novel example of a photo-induced single-crystal to single-crystal phase transformation is described for the title compound
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Uranium adsorption by non-treated and chemically modified cactus fibres in aqueous solutions
(2013)The adsorption efficiency of Opuntia ficus indica fibres regarding the removal of hexavalent uranium [U(VI)] from aqueous solutions has been investigated prior and after the chemical treatment (e.g. phosphorylation and ...
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Uranium adsorption by polyvinylpyrrolidone/chitosan blended nanofibers
(2019)PVP/chitosan blended nanofibers have been prepared and investigated as adsorbent material for the removal of hexavalent uranium (U(VI)) from aqueous solutions. The nanofibers have been characterized prior and after U(VI) ...
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Uranium analysis in Cypriot groundwaters by total alpha-radiometry and alpha-spectroscopy
(2011)Two different alpha-radiometric methods (e.g. alpha-spectroscopy and alpha-particle counting) have been applied to the determination of uranium in Cypriot groundwater samples after separation of the radionuclides by cation ...
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Uranium analysis in drinking waters in Cyprus
(2017)Uranium determination and speciation in drinking waters consumed in Cyprus has been carried out by means of alpha-spectroscopy and thermodynamic calculations. Sampling included tap waters from different areas as well as ...
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Uranium binding by biochar fibres derived from Luffa cylindrica after controlled surface oxidation
(2017)Controlled surface modification of biochar fibres derived from Luffa cylindrica sponges has been carried out by nitric acid and the degree of oxidation could be controlled by changing the acid concentration or the reaction ...
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Uranium chemistry in stack solutions and leachates of phosphogypsum disposed at a coastal area in Cyprus
(2008)The effect of the matrix composition (main constituents) on the concentration and chemical behavior of uranium in phosphogypsum stack solutions and leachates has been investigated. Solid and aqueous samples were taken from ...
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Uranium desorption from microplastic surfaces
(Springer, 2023)The desorption of uranium from microplastic surfaces has been investigated as a function of pH in aqueous solutions under ambient conditions. In addition, the effect of complexing ligands (e.g. EDTA) on the desorption from ...
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Uranium determination in water samples by liquid scintillation counting after cloud point extraction
(2010)The aim of this study is the radiometric determination of uranium in waters by liquid scintillation counting (LSC) after pre-concentration of the element by cloud point extraction (CPE). For CPE, tributyl phosphate (TBP) ...
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Uranium in ground water samples of Northern Greece
(2011)The activity concentrations of 238U and 234U have been determined in groundwater samples of hot springs and deep wells in Northern Greece. The analysis was performed by alpha spectroscopy after pre-concentration and ...
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Uranium levels in Cypriot groundwater samples determined by ICP-MS and α-spectroscopy
(2013)The uranium concentration and the isotopic ratio 238U/234U have been determined in Cypriot groundwater samples by ICP-MS after ultrafiltration and acidification of the samples and α-spectroscopy after pre-concentration and ...
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Uranium monitoring in ground- and wastewaters
(2018)Uranium in ground- and wastewater samples has been analyzed by alpha-spectroscopy after pre-concentration and separation by means of a chelating resin Lewatit TP 207, and following electrodeposition of the radioelement on ...
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Uranium recovery from phosphate rocks/minerals – A comprehensive review
(Elsevier, 2024)Although the use of nuclear energy is still viewed with caution due to various problems associated, such as the safe operation of 'aging' nuclear plants and the final disposal of nuclear waste, many countries in Europe are ...