[en] Niobium(V) was determined as a mixed ligand complex with gallic acid and 1,2-diaminocyclohexanetetraacetic acid in tartrate medium by a spectrophotometric method at 470 nm around pH 2.5, 40 minutes after preparation of the solution and at 25⁰C. The system conforms to Beer's law for an optimum range of 0.38 to 8.92 μg/ml of niobium with relative standard deviation of 2 to 5 percent. Sensitivity (A = 0.001 and 1-cm path length) is 0.015 μg/ml of niobium. The behavior of many ions was studied for their interference in determination of niobium and, in a few synthetic cation mixtures, niobium was estimated

[en] A method for the precipitation of plutonium(IV) oxalate from homogeneous solutions using diethyl oxalate is reported. The precipitate obtained is crystalline and easily filterable with yields in the range of 92-98% for precipitations involving a few mg to g quantities of plutonium. Decontamination factors for common impurities such as U(VI), Am(III) and Fe(III) were determined. TGA and chemical analysis of the compound indicate its composition as Pu(Csub(2)Osub(4))sub(2).6Hsub(2)O. Data are obtained on the solubility of the oxalate in nitric acid and in mixtures of nitric acid and oxalic acid of varying concentrations. Green PuOsub(2) obtained by calcination of the oxalate has specifications within the recommended values for trace foreign substances such as chlorine, fluorine, carbon and nitrogen. (author)

[en] We will discuss the challenges of visualizing large cosmological datasets. These include observational issues such as the masks and incomplete nature of the survey volume, cosmological issues such as redshift distortions and the difficulty of visualizing datasets that span cosmological epochs, as well as the inherent visualization challenges in presenting dense three-dimensional (3D) datasets. Two case studies will be presented. The first will feature the identification of filamentary structures in the large scale distribution of galaxies. The second case study will feature visualizations of the correlations between quasar absorption line systems and luminous red galaxies. Finally, we will give an overview of our visualization work-flow which features the use of the open-source 3D modeling program Blender.