Extraction Properties of Trioxides of Pentasubstituted Diethylenetriphosphines in Nitric Acid Solutions

Extraction of HNO₃ and microamounts of U(VI), Th(IV), Sc(III), and REEs(III) from HNO₃ solutions with solutions of trioxides of symmetrical dioctyltriphenyldiethylenetriphosphine and pentaphenyl-diethylenetriphosphine in dichloroethane was studied. The stoichiometry of the extractable complexes was determined, and the effective extraction constants of HNO₃ and REEs were calculated. As the number of phosphoryl groups in the extractant molecule increases, the extraction of metal ions from nitric acid solutions is enhanced. Replacement of the octyl radicals at the terminal phosphorus atoms by the phenyl radicals is accom-panied by an increase in extraction of metal ions from solutions with the HNO₃ concentration exceeding 3 M.__________Translated from Radiokhimiya, Vol. 47, No. 1, 2005, pp. 72–76.Original Russian Text Copyright © 2005 by Turanov, Karandashev, Bondarenko.     

Peculiarities of the ptcr effect in ferroelectrics with diffuse phase transitions

The PTCR effect in ferroelectrics with the diffuse phase transition BaSrNb₂O₆ (BSN) and Na_0.5Bi_0.5TiO₃ (NBT) has some peculiarities: the δ(T) anomaly in BSN is observed below the Curie point, in NBT it doesn't coincide with the anomalies of other electrophysical and optical properties and shows an anomalously large temperature hysteresis. These peculiarities may be explained by the diffuseness of spontaneous polarization temperature dependence. Besides in NBT the percolation effects are of importance.     

Spatial resolution of the multistep avalanche chambers

The spatial resolution of the multistep avalanche chambers is considered. The intrinsic spatial resolution (the full width at half-maximum) of these chambers is 260 μm. The influence of the signal amplitude on the spatial resolution of the chambers under irradiation by β particles is investigated. By analyzing the signal amplitude and selectively measuring the coordinates, or by estimating the signal amplitude and its contribution to the reconstructed image, it will be possible to raise the spatial resolution twofold to 0.5 and 1.0 mm for isotropic radiation of ¹⁴C and ³²P isotopes, respectively. In addition, the spatial resolution can be improved significantly when electrons escaping from solid-state neutron or γ-ray converters are detected.     

Elastic-hydrodynamic analysis of high pressure centrifugal compressors

Translated from Khimicheskoe i Neftyanoe Mashinostroenie, No. 8, pp. 17–19, August, 1989.     

Change in Iron Powder Properties with Treatment in Rolls

Conditioned iron powders are prepared by carbothermal reduction of “Blue Dust” (India) ore concentrate followed by compaction treatment in rolling mill and a decarburizing anneal. The properties of powder prepared by grinding in a vibration and rolling mill are determined. The method makes it possible to control the bulk density of the powder from 1.75 to 2.75 g/cm³. Determination of the production properties of the powders obtained and powder NC.100.24 by the same procedure established satisfactory conformity of the results. The technological desirability of preparing conditioned iron powder by treatment in a rolling mill is demonstrated.__________Translated from Poroshkovaya Metallurgiya, Nos. 3–4(442), pp. 12–16, March–April, 2005.     

High-modulus,high-strength carbon fibre based on polyacrylonitrile

Conclusions -- The effect of the method of preliminary heat treatment and of the structure of fibre being subjected to boronation on the strength of high-modulus carbon fibres has been shown.-- A moreoriented structure of the fibre subjected to boronation and stress relaxation during the heat-treatment process aid in bringing about an increase in strength of high-modulus carbon fibre up to 3.0–3.5 GPa at an elastic modulus greater than 700 GPa.All-Union Scientific Research and Project-Technological Institute of Electrical Carbon Articles, Élektrougli. Translated from Khimicheskie Volokna, No. 3, pp. 29–30, May–June, 1991.     

Copolymerization of acrylonitrile,methyl acrylate,and itaconic acid in thiocyanate solutions in the presence of hydrolyzed nitron fibre waste

Conclusions -- The kinetics of the copolymerization process of AN, MA, and IA in the presence of hydrolyzed Nitron fibre characterized by various degrees of hydrolysis has been studied. It has been found that introducing H-PAN into the reaction mixture leads to an increase in degree of conversion in the copolymerization process and to an increase in molecular weight of the copolymer synthesized.-- Fibre has been spun from the products of joint copolymerization of AN, MA, and IA in the presence of H-PAN with various concentrations of these in the solution and various SEC values. Introducing up to 5% by wt. of an H-PAN with an SEC not over 0.2 meq/g into the reaction mixture aids in obtaining fibres with satisfactory properties and opens up the possibility of still another way of solving the question of regenerating wet Nitron fibre wastes.Translated from Khimicheskie Volokna, No. 4, pp. 17–19, July–August, 1991.     

Improved Accuracy in Measuring Two-Terminal Network Parameters

A method is given for raising the accuracy in determining the parameters of a two-terminal network by the substitution method, which employs a personal computer and measurements with digital voltmeter and phasemeter. Results are given for three-component one-port networks.     

Model of Combined Hardening of Crystalline Materials by Coherent and Incoherent Precipitates in Application to Irradiated Iron-Based Alloys with BCC Structure

Friedel statistics are used to develop a scheme for calculating the force required to detach an edge dislocation from obstacles of different strength which pin it. A mechanism is proposed for hardening crystalline materials by using coherent precipitates. The scheme is based on the difference of the equilibrium structures of the matrix and precipitate. The Russell-Brown model of dispersion hardening of aging alloys is used to formulate a new criterion for determining the maximum force of interaction between a dislocation with a precipitate which it cuts through. The increase in the yield strength of certain irradiated iron-based model alloys with bcc structure as a result of the hardening of the alloys by coherent copper-nickel-manganese precipitates and micropores separately and in combination is calculated.__________Translated from Atomnaya Energiya, Vol. 98, No. 5, pp. 332–341, May 2005.     

Effect of plastic working on the structural stability of composite (nickel-chromium alloy)-tungsten materials

Conclusions The character of diffusional interaction of the components of tungsten-reinforced heat-resisting sheet composite materials produced by hot forging with subsequent plastic working depends on the latter's degree of plastic deformation. The loss of chromium from the surface of such a CM varies depending on the degree of plastic deformation and on the composition of the matrix alloy. Tungsten fibers stabilize the composition of a CM by acting as obstacles in the paths of chromium diffusion fluxes.Translated from Poroshkovaya Metallurgiya, No. 3(255), pp. 40–44, March, 1984.