Composite materials of diamond−(Co–Cu–Sn) system with improved mechanical characteristics. Part 1. The influence of hot re-pressing on the structure and properties of diamond−(Co–Cu–Sn) composite

We have studied the structure and tribological behavior of composite materials of the diamond–(Co–Cu–Sn) system, which were produced by sintering in molds at 800°C for 1 hour with subsequent hot re-pressing. It is shown that a change of hot re-pressing conditions makes it possible to produce nanocarbide Co₃C in the diamond–metal binder transition zone, instead of particles of structurally free graphite arising during graphitization of the diamond grain surface. The presence of nanocarbide provides an essential improvement of wear resistance of the composites.     

Correction to: Analysis of Performance and Updating of a Rectifying Column for Hydrofined Diesel Fuel Stabilization

Chemical and Petroleum Engineering - To the article “Analysis of Performance and Updating of a Rectifying Column for Hydrofined Diesel Fuel Stabilization,” by A. S. Bondarenko, A. M....     

Use of Digital Technologies for Selecting the Hydrogen Storage and Transportation Type

Chemical and Petroleum Engineering - The fourth article in a series of five papers devoted to hydrogen energy digitalization. The article discusses the methods for ensuring digitalization in the...     

Extraction of aromatic compounds from catalytic cracking light gas oil with nitromethane

Conclusions It has been shown that nitromethane can be used successfully for separating kerosene-gas oil fractions to obtain raffinates which satisfy the requirements for diesel fuel plus highly aromatized extracts which contain less than 6% of saturated hydrocarbons.Translated from Khimiya i Tekhnologiya Topliv i Masel, No. 8, pp. 27–29, August, 1967.     

Studies of the transport properties in the layered κ-phase ET2Cu[N(CN)2]Hal (Hal = Cl1 − Brxrx and I) salts. 2 Magnetic field effect on the thermopower of Hal = Cl salt

Thermopower S vs temperature dependences were measured for single crystals ET₂Cu[N(CN)₂]Cl. Magnetic field of 14 T shifts the S(T) curve to high temperatures. This behaviour is ascribed tentatively to the transport by the magnetic polarons (ferrons), the domains around free carriers that appear as ferromagnetically ordered regions in the antiferromagnetically ordered matrix and are stabilized by the magnetic field above the magnetic transition in the material. A peculiar zero value of the S is interpreted as an evidence for a collective motion of these quasiparticles.     

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.