scholarly journals Matrix-Assisted Ionization of Molecular Uranium Species

2020 ◽  
Vol 32 (1) ◽  
pp. 8-13
Author(s):  
Danielle R. Mannion ◽  
Joseph M. Mannion ◽  
Wendy W. Kuhne ◽  
Matthew S. Wellons
Keyword(s):  
Uranium Species

scholarly journals Dr. Ian Hutcheon Award: Spectroscopic Fingerprinting of Vapor-Phase Uranium Species

2020 ◽  
Author(s):  
David G. Weisz
Keyword(s):  
Vapor Phase ◽  
Uranium Species

scholarly journals Changes in u(VI) SPeciation Upon Sorption onto Montmorillonite from Aqueous and Organic Solutions

1991 ◽  
Vol 257 ◽  
Author(s):  
Catherine Chisholm-Brause ◽  
Steven D. Conradson ◽  
P. Gary Eller ◽  
David E. Morris
Keyword(s):  
Oxidation State ◽  
Aqueous Systems ◽  
X Ray ◽  
Ph Values ◽  
Uranium Oxidation ◽  
Organic Solutions ◽  
X Ray Absorption ◽  
Hydrolysis Of ◽  
Uranium Species ◽  
Lines Of Evidence

ABSTRACTThe speciation of UO22+ and UO22+/ TBP mixtures has been investigated in solution and intercalated with the reference smectite clay SAz-1 using x-ray absorption, Raman, andluminescence spectroscopies. Neither aquated UO22+ nor its TBP complex undergoes any detectable changes in uranium oxidation state on intercalation. Further, at the pH values employed in this work, there is no evidence for hydrolysis of the uranium species to generate dimeric or higher order uranium oligomers. However, we do find indications that the structures of the solution complexes are altered on intercalation, particularly for the UO22+TBP system and for more dilute UO22+/aqueous systems. In addition, several lines of evidence suggest that, at the loading levels used in this study, the uranyl species is interacting with two or more spectroscopically distinguishable sites on SAz-1.

Molecular dynamics simulation of the diffusion of uranium species in clay pores

2013 ◽  
Vol 244-245 ◽  
pp. 21-28 ◽  
Author(s):  
Xiao-yu Liu ◽  
Lu-hua Wang ◽  
Zhong Zheng ◽  
Ming-liang Kang ◽  
Chun Li ◽  
...  
Keyword(s):  
Molecular Dynamics ◽  
Molecular Dynamics Simulation ◽  
Dynamics Simulation ◽  
Uranium Species

Predominance Diagrams of Dissolved Uranium Species and logfO2(g)-pH Diagrams of U-PO43--Nacl-H2O System at 25°C, PCO2=10-3.5 Mpa

2013 ◽  
Vol 781-784 ◽  
pp. 3-8
Author(s):  
Xin Yu Wang ◽  
Shi Jun Ni ◽  
Ze Ming Shi
Keyword(s):  
Thermodynamic Model ◽  
Uranium Concentration ◽  
Phosphate Concentration ◽  
Oxidative Condition ◽  
Nacl Concentration ◽  
Solid Phases ◽  
Ph Range ◽  
Uranium Species ◽  
Predominance Diagrams

To explore the effect of logfO2(g), pH, uranium concentration, phosphate concentration and NaCl concentration on the predominance diagrams of dissolved uranium species and formation of solid phases containing uranium in the U-PO43--NaCl-H2O system at 25 °CandPCO2=10-3.5MPa, the thermodynamic model of this system was constructed. Based on the results of calculation, the logfO2(g)-pH diagrams were drawn. It can be found that: 1) the formation of uraninite needed enough reductive condition (about logfO2(g) < -50 ), while the formation of Na-Autunite needed the strict pH range (5<pH<8) in oxidative condition. 2)The addition of phosphate concentration could promote the formation of Na-Autunite, and inhibit the formation of U4O9(C). 3)The independent increasing of uranium concentration can lead to more kinds of uranium species.4) The variance of NaCl concentration had little impact on the formation of solid phases containing uranium.

Resonant Inelastic Soft X-ray Scattering Studies of U(VI) Reduction on Iron Surfaces

2003 ◽  
Vol 807 ◽  
Author(s):  
S. M. Butorin ◽  
D. K. Shuh ◽  
K. Kvashnina ◽  
I. L. Soroka ◽  
K. Ollila ◽  
...  
Keyword(s):  
Absorption Edge ◽  
Spectroscopic Analysis ◽  
Ex Situ ◽  
X Ray ◽  
X Ray Scattering ◽  
Primary Photon ◽  
Liquid Cell ◽  
Uranium Species ◽  
Ray Scattering

ABSTRACTWe report on the spectroscopic analysis of several samples relevant to the processes governing the behavior of oxidized uranium species in groundwater solutions under anoxic conditions. Both Fe samples with different times of exposure to the U(IV) solution and Fe metal-solution inetrfaces in the liquid cell ex-situ and in-situ, respectively. Resonant inelastic soft x-ray scattering is shown to be sensitive to the chemical state of uranium. The measurements were performed at a number of energies of the primary photon beam across the U 5d absorption edge. The results unambiguously indicate the reduction of U(VI) to U(IV) on the Fe surface.

Consecutive N2 loss from a uranium diphosphazide complex

2020 ◽  
Vol 49 (3) ◽  
pp. 578-582 ◽  
Author(s):  
Tara K. K. Dickie ◽  
Connor S. MacNeil ◽  
Paul G. Hayes
Keyword(s):  
Nmr Spectroscopy ◽  
X Ray ◽  
Multinuclear Nmr ◽  
X Ray Crystallography ◽  
Multinuclear Nmr Spectroscopy ◽  
Uranium Species

A uranium(iv) complex supported by an unusual diphosphazide ligand was prepared. Controlled, consecutive N2 loss was observed, affording well-defined uranium species that were characterized by multinuclear NMR spectroscopy and X-ray crystallography.

Colloidal Size and Redox State of Uranium Species in the Porewater of a Pristine Mountain Wetland

2019 ◽  
Vol 53 (16) ◽  
pp. 9361-9369 ◽  
Author(s):  
Gabrielle Dublet ◽  
Isabelle Worms ◽  
Manon Frutschi ◽  
Ashley Brown ◽  
Giada C. Zünd ◽  
...  
Keyword(s):  
Redox State ◽  
Uranium Species

Reduced Uranium Complexes: Synthetic and DFT Study of the Role of π Ligation in the Stabilization of Uranium Species in aFormalLow-Valent State

2009 ◽  
Vol 131 (30) ◽  
pp. 10406-10420 ◽  
Author(s):  
Ilia Korobkov ◽  
Serge Gorelsky ◽  
Sandro Gambarotta
Keyword(s):  
Dft Study ◽  
Uranium Complexes ◽  
Valent State ◽  
Uranium Species
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