Browsing Τμήμα Χημείας / Department of Chemistry by Submit Date
Now showing items 21-40 of 1299
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Regeneration of thermally aged Pt-Rh/CexZr1-xO2-Al2O3 model three-way catalysts by oxychlorination treatments
(2006)Pt-Rh/CexZr1-xO2-Al2O3 with 0.6 and 1.0 wt.% noble metal loadings were prepared and characterized for their metal dispersion with respect to CexZr1-xO2-free Pt-Rh/Al2O3 in fresh, thermally aged and oxychlorinated states. ...
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Effect of humic acid on the solid phase stability of UO2CO 3
(2009)The stability of UO2CO3 has been studied as a function of the humic acid concentration in 0.1M NaClO4, in the weak acidic pH range (4.5-5) under CO2 atmosphere. The solid phase under investigation has been prepared by ...
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Enamine-Based Hydrophilic Dynamic Covalent Polymer Networks: Effects of pH, and Copolymer Composition and Concentration on the Aqueous Swelling Degrees and the Gel Formation Times
(2015)In this work, we explore the formation in water of dynamic covalent polymer networks cross-linked via enamine groups. The polymer networks resulted from the combination of pairs of chemically complementary hydrophilic ...
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Synthesis and characterization of reversible and self-healable networks based on acylhydrazone groups
(2014)A series of seven dynamic covalent networks based on pentaerythritol tetra(benzohydrazide) and 1,10-decanediol dibenzaldehyde were prepared in N,N-dimethylformamide (DMF). The equilibrium degree of swelling in DMF and the ...
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Article
Structural and Redox Properties of Ce1-xZrxO2-δ and Ce0.8Zr0.15RE0.05O2-δ (RE: La, Nd, Pr, Y) Solids Studied by High Temperature in Situ Raman Spectroscopy
(2017)In situ Raman spectroscopy at temperatures up to 450 °C is used to probe the structural and redox properties of Ce1-xZrxO2-δ solids (x = 0-0.8) prepared by the citrate sol-gel and coprecipitation with urea methods. The ...
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Article
A simplified determination of uranium in phosphate rock and phosphogypsum by alpha-spectroscopy after its separation by liquid-extraction
(2012)A relatively rapid, economic and robust procedure is described for the radiometric analysis of uranium in phosphate rock and phosphogypsum. The analysis is performed by alpha spectroscopy after pre-concentration and ...
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The effect of natural organic matter on the formation and solubility of M(OH)4 solid phases
(2014)In this study the formation of M(OH)4 solid phases (e.g. Th(IV), Ce(IV) and Zr(IV)) has been investigated as a function of the natural organic matter (NOM) concentration in 0.1 M NaClO4, in the pH range between 2 and 5, ...
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The effect of humic acid on the formation and solubility of secondary solid phases (Nd(OH)CO3 and Sm(OH)CO3)
(2011)The formation of secondary Ln(III) solid phases (e.g. Nd(OH)CO3 and Sm(OH)CO3) has been studied as a function of the humic acid (HA) concentration in 0.1M NaClO4 aqueous solution and their solubility has been investigated ...
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Alpha radiometry of uranium in surface and ground waters by liquid scintillation counting after separation of the radionuclide by cation exchange
(2008)The alpha radioactivity of surface and ground water samples has been determined by liquid scintillation counting (LSC) after chemical preparation of the samples by cation exchange using the Chelex 100 resin. The method ...
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Spectroscopic investigations on the effect of humic acid on the formation and solubility of secondary solid phases of Ln2(CO3) 3
(2011)The formation of secondary Ln(III) solid phases (e.g., Nd 2(CO3)3 and Sm2(CO3) 3) was studied as a function of the humic acid concentration in 0.1 mol/L NaClO4 aqueous solution in the neutral pH range (5-6.5). The solid ...
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Article
Infrared spectra of some thin amorphous films of MoO3-In2O3 deposited by vacuum evaporation
(1989)The infrared absorption spectra of vacuum-evaporated MoO3-In2O3 thin films are reported for a series of films of varying compositions within the spectral range 4000 to 400 cm-1 and interpreted in relation to the spectrum ...
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Infrared spectroscopic study of vacuum evaporated amorphous thin films of MoO3-SiO
(1990)A series of amorphous MoO3-SiO thin films of varying compositions were investigated by infrared spectroscopy. In some cases, a shift in band frequency was observed. Some new peaks appeared when SiO was mixed in MoO3. These ...
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Article
Temperature programmed reduction of silica supported nickel catalysts
(1993)Nickel oxide promoted catalysts are prepared by simple precipitation, precipitation from homogeneous solution and impregnation methods and their reduction behavior is monitored with temperature programmed reduction (TPR) ...
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Article
Volatile emissions during storing of green food waste under different aeration conditions
(2016)Controlled field experiments were carried out for monitoring the emissions of three plastic commercial household waste bins, which were adapted for studying the effect of aeration process in the evolved volatiles, during ...
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Article
Polymers and oligomers with transverse aromatic groups and tightly controlled chain conformations
(1998)Anionic ring-opening polymerisation of spiro[cyclopropane-1,9′-fluorene] with fluorenyl anion as initiator yields polymers 1 with chains which are essentially all-anti and have transversely-oriented fluorenyl groups, as ...
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Synergistic effects of crystal phases and mixed valences in La-Sr-Ce-Fe-O mixed oxidic/perovskitic solids on their catalytic activity for the NO+CO reaction
(2000)Mixed oxidic and perovskite-type materials based on the La, Sr, Ce and Fe elements were prepared using a mixture of nitrates salts and heating at 1000°C. Three groups of solids were synthesized: (i) La(1-y)Ce(y)FeO3 (y=0.2, ...
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Catalytic behavior of La-Sr-Ce-Fe-O mixed oxidic/perovskitic systems for the NO+CO and NO+CH4+O2 (lean-NOx) reactions
(2000)Mixed oxides of the general formula La0.5SrxCeyFeOz were prepared by using the nitrate method and characterized by XRD and Mossbauer techniques. The crystal phases detected were perovskites LaFeO3 and SrFeO3-x and oxides ...
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Ring contraction of 1,3-diphenylbenzo[1,2,4]triazinyl radicals to 1,2-diphenylbenzimidazoles
(2014)Reductive ring contraction of 1,3-diphenyl-1,4-dihydrobenzo[e][1,2,4] triazin-4-yls (Blatter's radicals) using zinc powder (2 equiv.) in acetic acid heated to ca. 118 °C gives 1,2-diphenylbenzimidazoles in high yield. ...
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Article
Suzuki-Miyaura reactions of the soluble guanylate cyclase inhibitor NS2028: A non-product specific route to C-8 substituted analogues
(2011)Both soluble guanylate cyclase (sGC) inhibitors ODQ 1 and NS2028 2 are synthesized via improved protocols. In the former case treating 3,4-dihydroquinoxalin-2(1H)-one oxime 8, which can be prepared in two steps from ...