Hyperfine interactions of copper ions in the structure of high-temperature superconductors

Emission Mössbauer ⁶¹Cu(⁶¹Ni) spectra of simple MgO, NiO, Cu₂O, CuO oxides and superconducting La_{2 ? x} Sr _x CuO₄, Nd_{2 ? x} Ce _x CuO, and YBa₂Cu₃O_{7 ? x} copper metal oxides have been measured. It has been shown that emission Mössbauer spectroscopy on isotopes ⁶¹Cu(⁶¹Ni) makes it possible to determine the parameters of the electric gradient field tensor and magnetic field values in the copper sites of lattices of high-temperature superconductors and related materials.     

Improving the precipitation of arsenic trisulfide from washing waters of sulfuric-acid production of copper smelteries

Disadvantages of the sulfide method of purifying washing waters of the sulfuric-acid production are the formation of finely dispersed (particle size from 0.3 to 1.5 μm) difficult-to-filter precipitates of arsenic(III) sulfide and the danger of isolation of hydrogen sulfide into the atmosphere upon an overdose of sodium hydrosulfide. The coagulation of sols of arsenic sulfide is investigated in order to develop more efficient and rapid filtration technology of the precipitate. The filtration rate in various supply modes of sodium hydrosulfide and the dependence of settling rate and filtration on the presence of coagulants such as iron sulfate and aluminum sulfate are determined. It is established that the implementation of the distributed supply of sodium hydrosulfide during the precipitation of arsenic sulfide in combination with the application of such inorganic coagulant as iron(III) sulfate will make it possible to increase the particle size of the As₂S₃ phase by a factor of several times and increase the filtration and settling rates of pulps.     

Dependence of the Protective Concentration of a Mixture of Inhibitors from Several Reaction Series on the Polarities of Substituents in Their Molecules

Protective concentrations of mixtures of inhibitors from several reaction series (RSs), which decrease the corrosion rates a given number of times, are exponentially dependent on the sum of partial polarities of substituents in compounds belonging to the chosen RSs, provided that the total concentration of compounds for each RS is constant. The dependence is linearized in semilogarithmic log C _prvs – m coordinates.     

Photostructural reconstructions of As-S and As-Se semiconductor glasses

The results of experimental investigation of photoinduced changes in optical properties of semiconductor glasses of the As-Se and As-S systems are presented. With using the data of the Mössbauer emission spectroscopy on the ¹²⁹Te(¹²⁹I) isotope, the observed changes in optical properties can be attributed to the reconstruction of the glass matrix under the effect of radiation.     

Increasing the reliability and service life of the cathode unit of an electron accelerator with extraction of a large-cross-section beam to the atmosphere

The design of an electron accelerator cathode unit with short filament elements in the form of a coil without a tightening mechanism is described. The advantage of the developed design over those of cathodes with long filaments with tightening mechanisms is shown. The nonuniformity of the beam-current density distribution behind the foil is <3%. The filament power required for cathodes in the form of coils is 20% lower than that for long-filament cathodes at the same beam-current density. Mechanical stresses leading to a breakdown of the cathode filaments are absent. The service life is determined mainly by the emission-caused wear of cathodes.     

Leaching of lead cakes of zinc production in a complexing solvent

The process of leaching of lead cakes of zinc production in a complexing solvent—trilon B, which makes it possible to selectively extract lead into the solution—is studied with the use of mathematical modeling of the experiment. Its optimum conditions—pH, liquid-to-solid ratio within pulp, and temperature—are determined. The developed flow chart of cake processing provides zinc removal as a single product, recycling of zinc to the basic production, and reduction of current expenditure due to solvent regeneration.     

Inhibitive and residual protective effects of benzimidazole derivative upon acid corrosion of iron

The inhibitive and residual protective effects of an organic inhibitor, benzimidazole derivative, were studied. The protective effect K increased with the increasing concentration of the compound. The coefficient of the residual protective effect K _t of the inhibitor and its mixture with anions is a linear function of time. The time of the residual protective effect τ is a linear function of the inhibitor and anion concentration.     

Reversible addition of hydrogen to titanium alloys

This paper gives an overview of works on the reversible alloying of titanium alloys aiming at their much higher workability. The data cited convince the authors of the possibility of improving tangibly the whole technology of making products of titanium alloys for mechanical engineering applications.     

The efficiency of solar cells immersed in liquid dielectrics

The effect of an increase in the efficiency of solar cells (SCs) (in particular, common silicon SCs) by their immersion in an isotropic liquid dielectric is described. The presence of a dielectric thin film results in an increase in the SCs efficiency by 40–60% from the reference value. The current–voltage characteristic, fill factor and other characteristics of SCs are analyzed. The mechanisms of the increase in the efficiency of SCs are discussed.