Thermodynamic Modeling of Actinide Complexation with Acetate and Lactate at High Ionic Strength

The stability constants of NpO ₂ ⁺ , UO ₂ ²⁺ Am³⁺, and Th⁴⁺ with acetate and lactate anions has been measured in 0.3–5.0m NaCl media at 25°C by the solvent extraction technique. For the 1:1 complexation, the values of the stability constants increased in the order: NpO ₂ ⁺ < Am³⁺ < ₂ ²⁺ < Th⁴⁺, in accordance with the actinide charge density and reflecting the strongly ionic bonding of the complexes. The Pitzer ionic interaction parameters were calculated and used to estimate the thermodynamic stability constants at I = 0. Because our data were collected mainly in the high ionic strength region values of ⁽¹⁾ were estimated from values reported in the literature. For all stability constants the Pitzer model gives an excellent representation of the data using three interaction parameters ⁽⁰⁾, ⁽¹⁾, and COn leave from Institute of     

Use of zirconium and ruthenium isotope correlations in the analysis of spent nuclear fuels

An approach is proposed to use the isotope ratios⁹³Zr/⁹⁶Zr,⁹¹Zr/⁹⁶Zr and¹⁰¹Ru/¹⁰⁴Ru for the determination of plutonium contriubtion to the total burnup of a spent nuclear reactor fuel of low initial enrichment in²³⁵U (3.6%). This approach was verified by determining the total burnup of the fuel from the¹³⁷Cs and¹⁴⁸Nd monitors and subtracting the partial burnup due to²³⁵U from the value obtained.     

Transient chaos in two coupled,dissipatively perturbed Hamiltonian Duffing oscillators

The dynamics of two coupled, dissipatively perturbed, near-integrable Hamiltonian, double-well Duffing oscillators has been studied. We give numerical and experimental (circuit implementation) evidence that in the case of small positive or negative damping there exist two different types of transient chaos. After the decay of the transient chaos in the neighborhood of chaotic saddle we observe the transient chaos in the neighborhood of unstable tori. We argue that our results are robust and they exist in the wide range of system parameters.     

Poly­[[aqua­neodymium(III)]‐μ3‐decane‐1,10‐di­carboxyl­ato‐μ3‐9‐carboxy­nonane­carboxyl­ato]

The title compound, [Nd(C₁₀H₁₆O₄)(C₁₀H₁₇O₄)(H₂O)]_n, has a novel Nd–organic framework constructed from sebacic acid (C₁₀H₁₈O₄) linkers, the longest aliphatic ligand used to date in lanthanide metal–organic framework compounds. The structure contains edge‐shared chains of NdO₈(H₂O) tricapped trigonal prisms that propagate in the [100] direction, with Nd—O distances in the range 2.414 (4)–2.643 (4) Å.