WAIS—R factor structure in psychiatric and general medical patients.

Examined the factor structure of the WAIS—R in a sample of 200 general medical (GM) patients and 271 psychiatric patients. The mean age of the Ss was 38.9 yrs. Results of 2- and 3-factor principal factor solutions with varimax rotations were compared to the factor structure of the WAIS—R normative sample (n?=?1,880) and a sample of vocational counseling patients (n?=?84), as well as an additional sample of psychiatric patients (n?=?114). Across all of these samples, coefficients of congruence for the 1st 2 factors (Verbal, Performance) were .97 or greater, and coefficients of congruence for the 3rd factor (Freedom From Distractability) ranged from .93 to .97. Results indicate that the WAIS—R has a robust factor structure and provides empirical evidence for the existence of Verbal, Performance, and Freedom From Distractability factors on the WAIS—R in psychiatric and medical populations. (13 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

EXTRACTION OF NEPTUNIUM AND PLUTONIUM NITRATES WITH n-OCTYL(PHENYL)-N,N-DIISOBUTYL-CARBAMOYLMETHYLPHOSPHINE OXIDE∗

Distribution equilibria of Np and Pu in various valence states and stripping of Np(V) were studied in a system involving 0.20 M n-octyl(phenyl)-N,N-diisobutylcarbamoylmethylphosphine oxide + 1.2 M tributyl phosphate in dodecane as a solvent. Np(V) is weakly extractable at <2 M nitric acid but more effectively extractable at >3 M nitric acid, due to the disproportionation of Np(V) to Np(IV) and Np(VI). Addition of nitrous acid to solutions containing Np(V) increases the over-all extractabllity of Np, due to its partial oxidation to Np(VI). This is also the case In the presence of oxalic acid, both at room temperature and at 40^°C. Both Np(IV) and Np(VI) are highly extractable, but the reduction of Np(V,VI) to Np(IV) is slow even with a reductant as strong as sodium formaldehyde sulfoxylate. Pu(IV) is highly extractable and its reduction to Pu(III) with sulfoxylate Is incomplete in the two-phase system if the aqueous phase contains >0.5 M nitric acid. Extracted Np(VI) can be stripped by reduction to Np(V). The stripping rate is, however, slow with nitrous acid as the reductant at low nitric acid concentration. The reduction of Np(VI) by hydrogen peroxide is fast, but is followed by further reduction to Np(IV). Sulfurous acid reduces Np(VI) rapidly and, if no iron is present, only to Np(V), but Fe(II) induces further reduction to Np(IV).     

Study of Uranium Removal from Groundwater by Supported Liquid Membranes

The separation of uranium from synthetic Hanford site groundwater by liquid-liquid extraction and by supported liquid membranes (SLM) was atudied. Bis(2,4,4-trimethylpentyl) phosphinic acid, H[DTMPeP], contained in the commercial extractant Cysnex 272, was selected for the membrane carrier because of its selectivity for uranium over calcium and magnesium. n-Dodecane was used as diluent and polypropylene membranea were used as the support. A water soluble complexing agent, 1-hydroxyethane-1,1-diphoaphonic acid, HEDPA, was used as atrlpping agent.

The permeability coefficient of U(V1) was evaluated from a detailed study of the permeation of U(VI) through flat-sheet SLMs as a function of the membrane carrier concentration. The diffusion coefficient of the uranium complex in the organic phase was also evaluated from permeation experiments performed under loading conditions. Experiments were also carried out with Cs(II) and Fe(III) to measure the membrane selectivity for U(VI) over these two cations. A very high selectivity of U(VI) over Cs(II) was obtained, due the very low distribution ratio of Cs(II) with the extractant H[DTMPeP] (thermodynamic selectivity). In the case of Fe(III), a good selectivity was also obtained, due to the slow reaction of Fe(III) species with H[DTMPeP] (kinetic selectivity).

The possibility of concentrating U(VI) in the strip solution by a factor of at least 10³ has been experimentally demonstrated by properly designed distribution experiments.