Mechanical properties of high-temperature alloy ZhS32 at 1150–1250°C

The mechanical properties of single crystals of alloy ZhS32 at a temperature of 1150–1250°C and deformation rates of 3 × 10⁻⁵, 10⁻⁴, and 10⁻³ sec⁻¹ are studied. The characteristics of true ductility in tests for long-term strength in a temperature range of 1150–1250°C are determined. __________ Translated from Metallovedenie i Termicheskaya Obrabotka Metallov, No. 1, pp. 38–40, January, 2006.     

Production of apatite concentrate from fine-grain carbonate-silicate technogenic sands

The Kovdorsky GOK JSC increases the production of apatite concentrates by involving fine-grain sands with 10.3–10.5 % P₂O₅ content from waste piles into the processing flow. The new process and flotationagent mode were developed to produce apatite concentrate with 38.3 % P₂O₅ content from fine sands with 60–70 % content of ?0.071 mm fraction at the recovery as high as 60% P₂O₅.     

Radiation–Thermal Decomposition of Nitric and Acetic Acids in a Aqueous Nitrate Solution

The kinetics of radiation, thermal, and radiation–thermal decomposition of a mixture of nitric and acetic acids in water solutions of sodium nitrate is investigated under homogeneous conditions and with a solid phase introduced in the form of sandstone. The experimental data are used to calculate the temperature dependences of the rate of radiation, thermal, and radiation–thermal decomposition of the acids. The results obtained make it possible to calculate the dynamics of decomposition of acids for the conditions of deep burial of liquid radioactive wastes.     

Design of conduction band structure of TiO2 electrode using Nb doping for highly efficient dye‐sensitized solar cells

A barrier layer of undoped TiO₂ was deposited on the Nb‐doped TiO₂ electrode to suppress the recombination at the Nb‐doped TiO₂/dye–electrolyte interface for highly efficient dye‐sensitized solar cells (DSCs). The Nb content in TiO₂ was varied in a range of 0.7–3.5 mol% to modify the TiO₂ energy‐band structure. Nb‐doped TiO₂/dye interfaces were characterized by a combination of ultraviolet photoemission spectroscopy and optical absorption spectroscopy measurements, allowing the determination of the conduction band minimum (CBM) of the TiO₂ electrode and the lowest unoccupied molecular orbital of the N719 dye. The lowering of TiO₂ CBM by Nb doping induced the increase in short‐circuit current of DSCs. However, open‐circuit voltage and fill factor are decreased, and this result was ascribed to the enhanced recombination at the Nb‐doped TiO₂/dye–electrolyte interface. The effect of doping on charge transport in DSCs was analyzed using electrochemical impedance spectroscopy. We have shown that by introducing of TiO₂ barrier layer, the Nb doping content, which results in DSC highest efficiency, can be increased because of the suppression of the dopant‐induced recombination. The energy conversion efficiency of the solar cells increased from 7.8% to 9.0% when undoped TiO₂ electrode is replaced with electrode doped with 2.7 mol% of Nb because of the improvement of the electron injection and collection efficiencies. The correlation between the electronic structure of the TiO₂ electrode, charge transfer characteristics, and photovoltaic parameters of DSCs is discussed. Copyright © 2012 John Wiley & Sons, Ltd.     

Laser Pulses Shortening at Transient Backward SRS and Forward Scattering Suppression

Abstract

Mathematical simulation of the transient SRS process is performed taking into account backward scattering and Stokes-anti-Stokes parametric coupling of the forward waves. It is shown that the parametric coupling has a slight influence on the suppression of forward scattering. A main contribution to the SRS asymmetry is made by pumping exhaustion by the backward Stokes waves. The dynamics of scattering radiation formation is studied and the conditions for obtaining high-contrast pulses at SRS compression are formulated.