Higher oxidation states of americium have long been known; however, options for their preparation in acidic solution are limited. The conventional choice, silver-catalyzed peroxydisulfate, is not useful at nitric acid concentrations above about 0.3 M. We investigated the use sodium bismuthate as an oxidant Am3+ solution. Room-temperature produced AmO22+ quantitatively, whereas 80 °C AmO2+ quantitatively. efficacy method production oxidized was verified by fluoride precipitation and...

Rare earth elements (REEs) make unique and vital contributions to our current world of technology. Separating recycling REEs is great importance diversify the sources advance efficient use REE resources when supply limited. In light separation nanotechnology, diethylenetriamine-pentaacetic acid (DTPA) functionalized magnetic nanosorbents have been synthesized investigated for highly selective extraction heavy (Sm-Ho) (La-Nd) lanthanides (Ln) from aqueous solutions. The results demonstrated...

We have studied the oxidation of sulfur dioxide by dissolved oxygen in highly dilute solutions with a new differential optical absorption technique. measured rate catalyzed iron(III) over wide range pH, ionic strength, and presence various organic materials. The studies indicate that noncomplexing molecules are inhibiting at “high” pH values 5 above not “low” 3 below. Furthermore, order reaction respect to iron is different two regimes. This suggests mechanism this differs regimes probably...

Tetrathiafulvalene carboxylate associates with the charge neutral complex, Yb.DO3A, in methanolic solution to give rise a novel ternary species; tetrathiafulvalene unit transfers energy lanthanide, causing luminescence from Yb metal, indicating for first time that an electron donor chromophore can act as efficient sensitiser self-assembled system containing lanthanide acceptor.

The separation of hexavalent americium from the lanthanides in simulated PUREX raffinate solution using 1 M diamylamylphosphonate dodecane extraction was investigated. Hexavalent prepared room-temperature sodium bismuthate oxidation. Under these conditions majority were not oxidized and remained inextractable. A factor ∼50 provided for europium over nitric acid concentration range 6–7 M. Cerium exception with oxidation to CeIV resulting its co-extraction AmVI. However, since is readily...

The complexation of neodymium(III) and europium(III) with lactate was studied at variable temperatures by potentiometry, absorption spectrophotometry, luminescence spectroscopy, microcalorimetry. stability constants three successive complexes (ML(2+), ML(2)(+), ML(3)(aq), where M stands for Nd Eu L lactate) 10, 25, 40, 55, 70 °C were determined. enthalpies 25 determined Thermodynamic data show that the trivalent lanthanides (Nd(3+) Eu(3+)) is exothermic becomes weaker higher temperatures....

Through Density Function Theory (DFT) calculations, we set out to understand the structures and stabilities of aqueous phase complexes [M(III)(DTPA)-H(2)O](2-) (M = Nd, Am) as well changes in Gibbs free energy for complexation gas solution. All bonding analyses suggest that preference DTPA(5-) ligand Am over Nd is mainly due electrostatic covalent interactions from oxygen atoms with nitrogen chelates providing an additional, yet small, interaction. These results question exclusive use hard...

Tributyl phosphate (TBP) is the most common organic compound used in liquid-liquid separations for recovery of uranium, neptunium, and plutonium from acidic nuclear fuel dissolutions. The goal these processes to extract actinides while leaving fission products acidic, aqueous phase. However, radiolytic degradation TBP has been shown reduce separation factors impede back-extraction during stripping. As previous investigations radiation chemistry have focused on steady state radiolysis stable...

Stability constants of two DTPA (diethylenetriaminepentaacetic acid) complexes with lanthanides (ML2− and MHL−, where M stands for Nd Eu L diethylenetriaminepentaacetate) at 10, 25, 40, 55, 70 °C were determined by potentiometry, absorption spectrophotometry, luminescence spectroscopy. The enthalpies complexation 25 microcalorimetry. Thermodynamic data show that the Nd3+ Eu3+ is weakened higher temperatures, a 10-fold decrease in stability ML2− MHL− as temperature increased from 10 to °C....

We have synthesized diamond films in a flow tube system which methane is added downstream from microwave discharge 90% argon/10% hydrogen at 3 Torr. The chemistry this simplified because the not exposed to temperatures higher than 850 °C wall temperature of tube. Therefore, only reaction atoms with initiates system. Furthermore, uniform and speed. Under these conditions, deposited on silicon substrates for time about 1 ms after injection methane.

TALSPEAK is a liquid/liquid extraction process designed to separate trivalent lanthanides (Ln3+) from the minor actinides (MAs) Am3+ and Cm3+. Traditional organic phase comprised of monoacidic dialkyl bis(2-ethylhexyl)phosphoric acid extractant (HDEHP) in diisopropyl benzene (DIPB). The aqueous contains soluble aminopolycarboxylate diethylenetriamine-N,N,N’,N”,N”-pentaacetic (DTPA) concentrated (1.0–2.0 M) lactic (HL) buffer with acidity typically adjusted pH 3.0. This balances selective...

The reprocessing used nuclear fuel (UNF) releases volatile fission and activation products, including 129 I, into the off-gas of a processing plant. Mitigation release vapor phase radionuclides is necessary for meeting regulatory requirements in United States other countries. In an aqueous plant, radioiodine could be present several forms, depending on chemistry process used. Inorganic iodine will predominate species any shearing or voloxidation pretreatment dissolver (DOG). Organic iodides...

Domoic acid was orally administered to 3 cynomolgus monkeys at doses of 0.5 mg/kg for 15 days and then 0.75 another days. After the 30-day dosing period, treated were killed. Parameters monitored as markers toxicity included body weight, food water consumption, clinical observations, hematology, serum chemistry, light microscopy all major organs (including brain retina), glial fibrillary protein immunohistochemistry. in 24-hour urine samples measured several time points. All parameters...