Application of the Nanofiltration Method in Systems for Recycling of Washing Water in Photographic Development of Motion-Picture Films

The possibility of using the nanofiltration method for purification of washing water in photographic development of professional motion-picture films is analyzed. Characteristics of domestic membranes, OPMN-K of nanofiltration type and OFAM-KN of low-pressure reverse-osmosis type, obtained in desalting of silver-containing washing water, are presented.     

Two types of interface defects

The solution of a plane problem in the theory of elasticity for a two-component body with an interface, a finite part of which is either weakly distorted or is a weakly curved crack is constructed using the perturbation method. In the first case, it is assumed that the discontinuities in the forces and displacements at the interface are known, and, in the second case, the non-equilibrium nature of the load in the crack is taken into account. General quadrature formulae are derived for the complex potentials, which enable any approximation to be obtained in terms of elementary functions in many important practical cases. An algorithm is indicated for calculating each approximation. Families of defects are studied, the form of which is determined by power functions. The effect of the amplitude of the distortion and the shape of the interface crack on the Cherepanov–Rice integral as well as the shape of the distorted part of the interface on the stress concentration is investigated in the first approximation. An analysis of the applicability of the oscillating solution for a distorted interface crack is carried out. The results of the calculations are shown in the form of graphical relations.     

Mechanism of noncatalytic synthesis of tris(hydroxymethyl)phosphine. Nonempirical quantum-chemical approach

The gas-phase reaction of the synthesis of tris(hydroxymethyl)phosphine from phosphine and formaldehyde was studied using a calculation scheme based on the density functional theory with hybrid exchange-correlation functional B3LYP in the 6–311++G** basis. The reaction was shown to proceed with the participation of unstable intermediates containing three-membered ring. The transformation into final products includes opening of the three-membered ring and intramolecular proton transfer. The results can be useful at selecting catalysts and for explaining the mechanism of the catalytic reaction of tris(hydroxymethyl)phosphine synthesis.     

Local canted spin behaviour in Co1.4−x Zn x Ge0.4Fe1.2O4 spinels: A macroscopic, mesoscopic and microscopic study

DC magnetization, neutron depolarization and neutron diffraction (with both polarized and unpolarized neutrons) measurements have been reported for the Co_1.1−x Zn _x Ge_0.1Fe_1.2O₁ spinels with x=0.5, 0.6 and 0.7. Neutron depolarization and neutron diffraction measurements confirm the presence of a long range ferrimagnetic ordering of the local canted spins in these ferrite samples. The observed features of low field magnetization have been explained under the framework of thermally activated domain wall movement of ferrimagnetic arrangement of local canted spins. An important role of magnetic anisotropy (due to the presence of Co²⁺ ions) in establishing the magnetic ordering and domain kinetics in these ferrites has been observed.     

Synthesis of hydroxy derivatives of 2,5-diaryl-1,3,4-oxadiazoles

A method for the synthesis of hydroxy derivatives of 2, 5-diaryl-1,3,4-oxadiazoles has been developed which consists in the preparation of acetoxy derivatives of oxadiazole with their subsequent saponification by means of an alcoholic solution of sodium hydroxide.     

Synthesis and study of poly (1, 3, 4-oxadiazoles)

Various conditions for synthesizing poly (1,3,4-oxadiazoles) from carboxylic acids, their hydrazides, and polyhydrazides, are investigated. Methods of cyclodehydration of polyhydrazides using phosphorus oxychloride, sulfuric acid, and certain other reagents are not of general utility for synthesizing poly (1,3,4-oxadiazoles). Vacuum-heating polyhydrazides gives crosslinked polymers. A new method of preparing poly (1,3,4-oxadiazoles) is offered. It is the reaction of hydrazine sulfate or dihydrazides of acids with dicarboxylic acids in oleum solution. Some chemical properties of the compounds synthesized are investigated.     

Correlation of IR parameters with reactivity characteristics for the hydrazides of carboxylic acids

Measurements have been made of the frequencies of the N-H and C=O stretching modes in dilute solution in CCl₄ for 23 aliphatic and aromatic substituted hydrazides of carboxylic acids. These are compared with the (⁰) Taft constants. Measurements have also been made of the basicity constants at 25 in water and the rate constants for reaction with phenyl isocyanate at 25. Correlation equations are derived for the transfer of electronic effects across the -CONH-bridge. It is found that the sign of the reaction constant in the correlation of with ⁰ reverses on passing from aromatic amines to amides via the hydrazides of carboxylic acids.We are indebted to L. M. Litvinenko and A. F. Popov for a discussion of the results.     

Detoxication of spent bleaching-fixative solutions

Various technological schemes for detoxication of spent bleaching-fixative solutions, with sodium peroxocarbonate as an oxidizing agent and multistage acid-alkaline treatment making possible recovery of separate valuable components, were studied. A method for minimization of the expenditure of the oxidizing agent was chosen.     

Synthesis of willemite by modified sol-gel technique

Silicate luminophor Zn₂SiO₄ : Mn was synthesized using silica gel as an active form of silicon dioxide. Factors affecting the degree of crystallinity of the silicate obtained were studied. Willemite was doped with manganese(II) in the course of synthesis. The luminescence parameters of the resulting samples were estimated.Translated from Zhurnal Prikladnoi Khimii, Vol. 77, No. 10, 2004, pp. 1605–1609.Original Russian Text Copyright © 2004 by Golovkin, Grekov, Chernovets.