No abstract available

[en] The paper presents data on the solubility of La, Ce, Pr, Nd sulfates in the polycomponent system La₂(SO₄)₃*8H₂O-Ce₂(SO₄)₃*8H₂O-Pr₂(SO₄)₃*8H₂O-Nd₂(SO₄)₃* 8H₂O-H₂SO₄-H₂O (at 25^oC and 64^oC) as well as in the same polycomponent system but in the presence of CaSO₄*2H₂O. The solubility of the sulfates - octahydrates of Pr at 25^oC and 64^oC and of La and Ce at 64^oC in tricomponent system Ln₂(SO₄)₃*8H₂O-H₂SO₄-H₂O are also reported

No abstract available

[en] Phase relations in NaLn(SO₄)₂-CaSO₄ (Ln=La,Ce,Nd) system are investigated using X-ray phase and complex thermal analyses. Luminescent features and photoconductivity of compounds formed in systems are investigated, as well. It is determined, that both luminescence and photoconductivity are observed in lanthanum-containing compounds, while in cerium-containing ones - only luminescence is observed, and in neodymium-containing specimens neither photoconductivity nor luminescence are observed

No abstract available

[en] The G-values for H₂ are measured for MnSO₄ x 5H₂O, FeSO₄ x 7H₂O, CoSO₄ x 7H₂O, NiSO₄ x 7H₂O, MgSO₄ x 7H₂O and 3 CdSO₄ x 8H₂O. Also the hydrogen yields are measured for FeNH₄(SO₄)₂ x 12H₂O and AlNH₄(SO₄)₂ x 12H₂O. The yield depends upon the dimensions of the crystals, except for FeSO₄ x 7H₂O, MnSO₄ x 5H₂O and 3CdSO₄ x 8H₂O. The G-values lie in the range between 0.56 and 0.002. Substitution of small amounts of Fe²⁺ for Ni²⁺ in NiSO₄ x 7H₂O and for Mg²⁺ in MgSO₄ x 7H₂O increases G(H₂). Substitution of Cd²⁺ for Fe²⁺ in FeSO₄ x 7H₂O reduces G(H₂) to about 35%. A reaction scheme is proposed for the observed phenomena in NiSO₄ x 7H₂O. It is concluded that the oxidizing species, which is created upon irradiation is more mobile in the crystal than the reducing species, and that inside the crystals a considerable fraction of the initially formed species recombines. Also there are indications that a fraction of the hydrogen formed inside the crystal is reoxidized before it can diffuse out of the crystal. (orig.)

[en] We have carried out performance evaluation of indigenously manufactured controlled potential coulometer for the determination of uranium and plutonium respectively in Rb₂U(SO₄)₃ and K₄Pu(SO₄)₄ chemical assay standards. The coulometric results obtained on uranium determination showed an insignificant difference as compared with the biamperometric results at 95% and 99.9% confidence levels while for plutonium determination showed a difference of -0.4% at 95% with respect to expected value. The results obtained show that indigenous coulometer is suitable for uranium and plutonium determination in chemical assay standards. (author)

No abstract available

[en] Double ammonium and RE sulfates of the composition NH₄Ln(SO₄)₂xH₂O for Ln=Gd, Ho, Yb and Lu and (NH₄)₆Ln₄(SO₄)₉x2H₂O for Ln=Tb, Dy and Er were produced by the isothermal evaporation from solutions at 80-95 deg C. (NH₄)₆Th₄(SO₄)₉x2H₂O crystals are referred to the monoclinic crystal system. Lattice parameters are equal to: a=9.008 (5), b=18.323(8), c=21.39(1) A, β=95.33(5)deg, Z=4 Atom coordinates, interaeltomic distances, valent angs are given. Compound structure represents a framework composed of Tl-polyhedrons of two types and SO₄-tetrahedrons. Non-equivalence of crystallochemical functions of NH₄-group in (NH₄)₆Tb₄(SO₄)₉x2H₂O structure is revealed. It is shown that in terms of the composition of stable double sulfates ammonium salts have the strongest resemblance with potassium salts

[en] Luminescence of Europium in alkali sulphates is reported. Europium is found to be in a trivalent state in Na₂ SO₄ and Li₂ SO₄. In K₂ SO₄, Rb₂ SO₄ and Cs₂ SO₄, both Eu³⁺ and Eu²⁺ were found for low concentration of the dopant, but for high concentration, only Eu³⁺ was present. Further, there was Eu³⁺ → Eu²⁺ conversion found, when the samples were exposed to gamma rays. The conversion is very prominent in Rb₂ SO₄. When the samples were annealed to 300^oC, there was back conversion to Eu³⁺. It is suggested that these properties are useful in radiophotoluminescence (RPL) dosimetry of the ionizing radiations. It may furnish a new type of storage phosphor for X-rays. (author)