Erratum to: “Synthesis and Reactions of Novel Fused 1-(8-Hydroxy-7-iodoquinoline-5-sulfonyl)- 1H-pyrazolo-[3,4-d]pyrimidine-3-carbonitrile Derivatives” [Russian Journal of General Chemistry 88 (3), 560–563 (2018)]

Russian Journal of General Chemistry - The project was financially supported by King Saud University, Vice Deanship of Research Chairs.     

Determination of gold(III) alone or in some mixtures and alloys by potentiometric titration of iodide

The present work is an application of iodide to the reduction of gold(III), in an attempt to develop new method for gold(III) based on potentiometric back-titration of the excess of iodide with mercury(II). Although it was proved by calculation that the reduction of tetrachloroaurate to the metal should proceed quantitatively to completion, yet our experiments showed that the reduction under ordinary conditions, gave Au(I) in the form of a white precipitate of AuI. We succeeded to push the reduction with iodide to the metal by an excess of ethanol-ether catalyzed iodide at somewhat elevated temperature.With the experimental conditions established a reliable procedure have been developed involving a potentiometric finish which enabled accurate determination of gold(III), either alone or in some of its alloys.     

Studies on halogen derivatives of phenylazochromotropic acid: I. The acid-base properties

The acid-base properties of six halogen derivatives of phenylazochromotropic acid have been studied in an attempt to apply them as metallochromic or chromophoric indicators. The absorption spectra are studied in buffer solutions of varying pH values. The variation of spectra with pH indicates the presence of two equilibria between H₂D^2?, HD^3? and D^4? species. The pK values of the naphthlenic OH groups are determined spectrophotometrically and are discussed in relation to molecular structure while those of the sulfonic acid groups are determined potentiometrically.     

Measurement of high chain extensions in polyethylene by gel permeation chromatography

Chain extensions above 1000 Å have been measured in two independent ways for various linear polyethylenes which had either been annealed in or crystallized into the high-pressure hexagonal phase. The distributions of fold-stem lengths measured from fracture-surface statistics and by gel permeation chromatography (GPC) molecular weight analysis of nitrated polymer agree reasonably well both in shape and position. Thinner lamellas, contributing to separate low melting peaks are, however, generally not recorded in fracture surfaces. The best agreement between the two measures, in their averages and overall distributions, is when the GPC weight distribution is compared with the number fracture-surface histogram. This is explicable in terms of the details of nitration.     

The viscosity and diffusion coefficients of eighteen binary gaseous systems

The paper reports accurate measurements of the viscosity of the eighteen binary gaseous systems: CF₄ with He, Ne, Ar, N₂, CO₂, CH₄; SF₆ with He, Ne, Ar, N₂, CO₂, CH₄, CF₄ and O₂ with He, Ne, CO₂, CF₄, SF₆. The measurements were performed in a high-precision oscillating-disk viscometer at atmospheric pressure and in the temperature range 25–200°C for the systems containing CH₄ or SF₆ and in the temperature range 25–400°C for the remainder. The reported viscosities are believed to be accurate to within ±0.1% at room temperature and to within ±0.2% at 400°C.It is shown that the data conform to the extended law of corresponding states developed by Kestin, Ro and Wakeham despite the complexity of some of the component gases. The standard deviation between the experimental values and those calculated from the law of corresponding states is only 0.3% which is commensurate with the uncertainty in the experimental results.Binary diffusion coefficients derived from the mixture viscosity data are also presented; they have an estimated uncertainty of ±2%.     

Fuzzy portfolio optimization a quadratic programming approach

The topic of this paper is as, the title shows, to introduce the formulation of fuzzy portfolio optimization problem as a convex quadratic programming approach and then give an acceptable solution to such problem. A numerical example included in the support of this paper for illustration.     

Back titration with mercuric nitrate in alkaline medium; analysis of binary mixtures of barium, strontium or magnesium together with lead, cobalt, nickel or copper

Summary Mercuric nitrate has proved to be a suitable back titrant for EDTA solutions in excess of the amounts reacting quantitatively either with one of the tetrad lead, cobalt, nickel or copper in the presence of one of the triad barium, strontium or magnesium atPh 8 or 9, or with both cations atph 11. This behaviour was the basis underlying the analysis of binary mixtures of the possible combinations between cations of the two groups. The end-points were detected potentiometrically with reasonable jumps and with fair agreement with the theoretical equivalence points.     

SFT-stability and Krull dimension in power series rings over an almost pseudo-valuation domain

Let \(R\) be an APVD with maximal ideal \(M\) . We show that the power series ring \(R[[x_1,\ldots ,x_n]]\) is an SFT-ring if and only if the integral closure of \(R\) is an SFT-ring if and only if ( \(R\) is an SFT-ring and \(M\) is a Noether strongly primary ideal of \((M:M)\) ). We deduce that if \(R\) is an \(m\) -dimensional APVD that is a residually *-domain, then dim \(R[[x_1,\ldots ,x_n]]\,=\,nm+1\) or \(nm+n\) .