Sorption of Europium (III), Cobalt (II) and Cesium (I) by Fresh Water Sediment Fractions Part 2: Effect of Some Environmental Ligands

The sorption behaviour of the radiotracers Eu⁹⁺, Co²⁺ and Cs⁺ by the sediment fractions: sand, coars silt, fine silt and clay was investigated from aqueous solutions containing the complexing agents; humic acid, sodium phosphate or disodium EDTA. The effect of ligand concentration on the sorption of these elements by the sediment fractions was elucidated at varying pH values. The results obtained are interpreted in the light of the complex formation between the ligand and the metal cations beside the interaction between the ligand and the respective sediment fraction investigated.     

A Carbon-13 NMR Assignment Study of Certain 6-Substituted Dibenz [c,e] Azepine 5, 7-Dione

The natural abundance carbon-13 nuclear magnetic resonance spectra of diphenic acid and some 6-substituted dibenz [c,e] azepine, 5, 7-dione - which can be considered also as N-substituted diphenimide - were recorded using Fourier transform technique. The chemical shifts of various carbon resonance have been assigned on the basis of chemical shift theory, the signal multiplicity observed in the single frequency off-resonance decoupled (SFORD) spectra and comparison with the chemical shifts of the model compounds.     

Fast grey ra as a new colorimetric reagent. Micro-determination of molybdenum

Fast Grey RA dye has proved to be a suitable colonmetric reagent for the determination of molybdenum amounts covering the micro-range of 0.05 to 10 p p m in an acetone-water medium. Beer's law is proved to be valid through the whole range. Serious interferences are due to Fe⁺³, Cu⁺², Zr, V and Bi Ferric iron up to 200 μg per 10 ml is masked with ascorbic acid, whereas cupric ion up to 20 μg per 10 ml is masked with ascorbic acid and ammonium thiocyanate solutions.     

Extension of plurisubharmonic currents

Let A be a closed subset of an open subset of ⁿ and T be a negative current on \ A of bidimension (p,p). Assume that T is psh and A is complete pluripolar such that the Hausdorff measure , then T extends to a negative psh current on . We also show that if T is psh or if dd ^cT extends to a current with locally finite mass on , then the trivial extension of T by zero across A exists in both cases: A is the zero set of a k–convex function with kp–1 or . Our basic tool is the following theorem [El3]: Let A be a closed complete pluripolar subset of an open subset of ⁿ and T be a positive current of bidimension (p,p) on \ A. Suppose that and exist (resp. exists and dd ^cT 0 on \ A), then there exists a positive (resp. closed positive) current S supported in A such that . Furthermore, we give a generalization of some theorems done by Siu and Ben Messaoud-El Mir and Alessandrini-Bassanelli without requiring anything from dT.     

Semilinear Perturbations of Harmonic Spaces,Liouville Property and a Boundary Value Problem

Let (X,) be a P-harmonic Bauer space and let be a Borel measurable function on X×R satisfying conditions (A) through (D) of Section 2 (e.g., (x,t)=t|t|^–1 where >1). For every Kato family M of potential kernels on X let ^M U(X) denote the set of all real continuous functions on X such that u+K ^M _D (,u)(D) for every open relatively compact subset D of X. We study the existence of a non-trivial function in ^M U(X) which is dominated by a given positive harmonic function on X. If X is a domain of R ^d , is a positive Kato measure on X and L is a second-order differential operator in R ^d , we apply our study to derive a characterization of finite positive measures on the minimal Martin boundary ^M ₁ X for which the boundary value problem Lu=(,u) in X and u= on ^M ₁ X is solvable.     

Mixed ligand extraction of cobalt(II) by thenoyltrifluoroacetone and triphenylphosphine or triphenylarsine oxides in chloroform

Extraction of Co(II) from perchlorate aqueous media by mixtures of thenoyltrifluoroacetone and triphenylarsine oxide or triphenylphosphine oxide in chloroform has been studied. It is found that the presence of these oxides enhances the extraction of Co(II). Synergic factors and formation constants were calculated and interpreted in the light of the electron donating properties of these oxides.     

The electrochemical reduction of some fused ring systems

The electrochemical reduction of some fused ring systems containing four carbonyl moieties has been studied in alcoholic aqueous media. A mechanism has been proposed and clarified in which one carbonyl is reduced to a methylene group via an uptake of four electrons.     

Neutron-activation analysis by standard addition and solvent extraction Determination of traces of antimony

The application of neutron activation analysis by standard addition and solvent extraction to the determination of traces of antimony in aluminium and rocks is reported. Three simple extraction procedures, using isopropyl ether, hexone, and tributyl phosphate, are described for the selective separation of radioantimony from interfering radionuclides. Antimony concentration is measured by counting the activities of the (122)Sb and (124)Sb photopeaks at 0.564 and 0.603 MeV.