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Abstract  

The extraction order of Th(IV), U(VI) and Mo(VI) based on pH0.5 values is Mo(VI)>U(VI)>Th(IV). Quantitative extraction has been observed for U(VI) by mixture of 10% (v/v) LIX 84 and 0.1M dibenzoylmethane at pH 4.2 and by mixture of 10% LIX 84 and 0.05M HTTA in the pH range 5.5–7.3 and for Mo(VI) by 10% LIX 84 from chloride media at pH 1.5. The order of extraction of Mo(VI) from 1N acid solutions is HCl>H2SO4>HNO3>HClO4 and extraction decreases very rapidly with increase in the concentration of HCl as compared to that from H2SO4, HNO3 and HClO4 acid solutions. The diluents C6H6, CCl4 and CHCl2 are found to be superior ton-butyl alcohol and isoamyl alcohol for extraction of Mo(VI). Influence of concentration of different anions on the extraction of U(VI) and Mo(VI) has been studied. Very little extraction has been observed in case of Th(IV) by LIX 84 or its mixtures with other chelating extractants or neutral donors.

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Abstract  

We have investigated the behaviour of109Cd, in two-phase systems: (HDEHP–C6 H6/ H3 PO4–HClO4–LiOH, =0.2), as a function of the independent equilibrium parameters which define the system: pH, equilibrium concentration of H3 PO4 and total concentration of HDEHP in the organic phase. The data have been interpreted in terms of the existence of phosphoric complexes characterized by their order 1 with regard to H3 PO4 and their charge z. The l and z. values are: 0<1<2, z=–2, 0, 1, 2 for the following ranges: 0.7<pH<2.7 and CH3 PO4<4M. Stability constants of the predominant complexes have been obtained. Finally, a formulation of these complexes has been proposed on the basis of partial charge of the atoms. Some complexes, could be formulated as hydroxy-phosphoric species, resulting from competition between hydroxy and dihydrogenophosphate anions. In concentrated phosphoric acid (CH3 PO4=4M), complexation of cadmium is not more than 25%.

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Abstract  

The complexes Mn(II), Co(II), Ni(II) and Zn(II) with 4-oxo-4H-1-benzopyran-3-carboxaldehyde were synthesized and characterized by elemental analysis, infrared and UV spectroscopy, X-ray diffraction patterns, magnetic susceptibility, thermal gravimetric analysis, conductivity and also solubility measurements in water, methanol and DMF solution at 298 K. They are polycrystalline compounds with various formula and different ratio of metal ion:ligand. Their formula are following: [MnL2(H2O)](NO3)2·2H2O, [CoL2](NO3)2·3H2O, [NiL2](NO3)2·3H2O, [CuL2](NO3)2·H2O and [ZnL3](NO3)2, where L = C10H6O3. The coordination of metal ions is through oxygen atoms present in 4-position of γ-pyrone ring and of aldehyde group of ligand. Chelates of Mn(II), Co(II), Ni(II) and Cu(II) obey Curie–Weiss law and they are high-spin complexes with the weak ligand fields. The thermal stability of analyzed complexes was studied in air at 293–1,173 K. On the basis of the thermoanalytical curves, it appears that thermal stability of anhydrous analysed chelates changed following: Cu (423 K) < Zn (438 K) ~ Co (440 K) < Ni (468 K). The gaseous products of thermal decomposition of those compounds in air atmosphere are following: CO2, CO, NO2, N2O, hydrocarbons and in case of hydrates also water. The molar conductance data confirm that the all studied complexes are 1:2 electrolytes in DMF solution.

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substitute for the traditional Chlorhydrin and Halcon processes [ 1 , 2 ]. Extensive efforts have been made to develop an alternative process for the direct epoxidation of C 3 H 6 using molecular oxygen as an oxidant. Especially, the approach combining

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Journal of Thermal Analysis and Calorimetry
Authors:
Viorel Cîrcu
,
Ana S. Mocanu
,
Constantin Roşu
,
Doina Manaila-Maximean
, and
Florea Dumitraşcu

, 6.3. 1 H NMR (300 MHz, CDCl 3 ): 8.12 (s, 1H), 7.74–7.51 (m, 12H), 7.42–7.34 (m, 5H), 7.22 (m, 2H), 7.03–6.98 (m, 4H), 6.90 (d, 1H, 4 J = 2.4 Hz), 6.60 (dd, 3 J = 8.4 Hz, 4 J = 2.4 Hz, 1H), 4.04 (m, 4H), 3.89 (s, 3H), 1

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4 H 6 O 4 , Sigma-Aldrich) was used as a precursor of palladium and fullerite C 60 powder (99.99%, Sigma-Aldrich) was applied as a precursor of carbon. Both compounds were evaporated from two separated sources using electrical heaters. PVD

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the MPW1PW91/6-31++G** theoretical level compared to the reactants and are given in Table 3 . The C 2 –H 6 and C 5 –H 11 bond distances increase, which implies breaking of this bond (1.095–1.01–1.497–1.539 Å) in the TSs. The C 2 –C 3 and C 4 –C 5

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Reaction Kinetics, Mechanisms and Catalysis
Authors:
Viorel Chihaia
,
Karl Sohlberg
,
M. Scurtu
,
C. Hornoiu
,
M. Caldararu
,
C. Munteanu
,
G. Postole
,
N. I. Ionescu
,
T. Yuzhakova
, and
A. Redey

tin dioxide based catalysts was tested with a propylene oxidation reaction. The surface behavior and the activity in C 3 H 6 oxidation on SnO 2 /γ-Al 2 O 3 samples was compared with those of the corresponding support γ-Al 2 O 3 and bulk SnO 2 . The

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Journal of Thermal Analysis and Calorimetry
Authors:
Francisco J. N. Maia
,
Viviane G. Ribeiro
,
Claudenilson S. Clemente
,
Diego Lomonaco
,
Pedro H. M. Vasconcelos
, and
Selma E. Mazzetto

.77 (m); 6.05 (t, 1H); 6.09 (d, 2H). MS: m/z = 314 (M + ) and 316 (M + ). Hydrogenation of cardol Cardol (3.0 g) was dissolved in 10 mL of ethanol (previously purged with H 2 ), and 10% Pd/C (0.3 g) was added

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reunited according their retention factors (RF). Cardanol: light brownish oil, 1 H NMR (CDCl 3 , δ): 1.03 (t, 3H); 1.45 (m); 2.19 (t, 2H); 5.13 (m); 5.21; 5.53 (m); 5.92 (m); 6.79 (m, 1H); 6.82 (m, 1H); 6.86 (s, 1H); 7.22 (t, 1H

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