Inner continuation of regular functions and a problem of kaufman

Translated from Ukrainskii Matematicheskii Zhurnal, Vol. 41, No. 3, pp. 408–412, March, 1989.     

Carbon fibers modified with molybdenum for sorption of arsenic(V)

Procedure for obtaining new hybrid sorbents based on carbon fibers and chitosan-carbon materials modified with molybdenum, which determines the affinity of the sorbents for arsenate ions, is described. The surface morphology was examined and a qualitative chemical analysis of the surface of the composite sorbents was made by the method of scanning electron microscopy–energy-dispersive analysis. Sorption isotherms were obtained for unmodified materials, carbon fibers and chitosan-carbon materials, and hybrid sorbents in twicedistilled and tap water at low As(V) concentrations.     

Generalized capacities and polyhedral surfaces

In the paper, the theory of extremal length of vector measures is used to show that the generalized condenser capacity in the sense of Aikawa and Ohtsuka is related to the module of the family of surfaces separating the condenser’s plates and disjoint with a given set. It is proved that the system of polyhedral surfaces from the above family is sufficient for approximating the module of this family. Bibliography: 17 titles.     

Metric characteristics of space ring domains with radial slits that are normal in Grötzsch’s sense

The paper establishes metric and functional characteristics of p-normal (in Grötzsch’s sense) ring domains with radial slits, 1 < p < + ∞. Bibliography: 7 titles.     

Generalized quadrangles,symmetrization, and nonunivalent mappings

In this paper one introduces R- and S-transformations of admissible metrics and for O-univalent mappings one proves theorems on the variation of the moduli of generalized quadrangles under these transformations.Translated from Zapiski Nauchnykh Seminarov Leningradskogo Otdeleniya Matematicheskogo Instituta im. V. A. Steklova AN SSSR, Vol. 154, pp. 163–174, 1986.     

Synthetic calcium aluminosilicates and their sorption properties with respect to Sr<Superscript>2+</Superscript> ions

Sorption characteristics of synthetic calcium aluminosilicates (CAS) obtained in the multicomponent CaCl₂–AlCl₃–KOH–SiO₂–H₂O system are presented. The isotherms of Sr²⁺ sorption on CAS from aqueous solutions containing no additional salts were measured for Sr²⁺ concentration from 0.5 to 11.1 mmol/L and solid to liquid phase ratio S: L = 1: 100. The maximum sorption capacity of synthetic CAS was determined, the phase distribution constants of Sr²⁺ ions at different S: L ratios were found. The recoveries of Sr²⁺ ions from solutions containing 0.01 mol/L Ca(NO₃)₂ and from a solution simulating water of the Mayak plant sewage pond No. 11 were determined.