Dynamics of adsorption by zeolites from the liquid phase, simulated using data on adsorption statics

A mathematical model for calculation of the dynamics of liquid-phase adsorption in a fixed sorbent bed is constructed on the basis of material balance equations solved by numerical integration on the assumption of a constant mass-transfer coefficient and a limiting inner-diffusion resistance.     

The Use of Hydrogen as a Fuel for Engines in the Energy Cycle of Remote Production Facilities

The approach to using hydrogen as fuel, which ensures the smooth operation of autonomous power systems that use renewable energy sources (wind or solar power installations) with the stochastic mode of power generation, has been presented. The fundamental possibility of implementing the nondetonation combustion of hydrogen via the addition of ecologically clean components or a small percentage of methane has been demonstrated by methods of mathematical modeling.

     

A Spectral Study of the Complexation between the Hybrid Spiropyran Molecules and Metal Ions

Russian Journal of General Chemistry - The absorption and fluorescent, as well as photochromic properties exhibited by hybrid spiropyran during formation of complexes between its molecules with...     

Erratum to: Fusibility of Agricultural Plant Waste Ash under the Conditions of High-Temperature Processing

Russian Journal of Applied Chemistry - Erratum     

Pathways to Triplet or Singlet Oxygen during the Dissociation of Alkali Metal Superoxides: Insights by Multireference Calculations of Molecular Model Systems

Recent experimental investigations demonstrated the generation of singlet oxygen during charging at high potentials in lithium/oxygen batteries. To contribute to the understanding of the underlying chemical reactions a key step in the mechanism of the charging process, namely, the dissociation of the intermediate lithium superoxide to oxygen and lithium, was investigated. Therefore, the corresponding dissociation paths of the molecular model system lithium superoxide (LiO₂) were studied by CASSCF/CASPT2 calculations. The obtained results indicate the presence of different dissociation paths over crossing points of different electronic states, which lead either to the energetically preferred generation of triplet oxygen or the energetically higher lying formation of singlet oxygen. The dissociation to the corresponding superoxide anion is energetically less preferred. The understanding of the detailed reaction mechanism allows the design of strategies to avoid the formation of singlet oxygen and thus to potentially minimize the degradation of materials in alkali metal/oxygen batteries. The calculations demonstrate a qualitatively similar but energetically shifted behavior for the homologous alkali metals sodium and potassium and their superoxide species. Fundamental differences were found for the covalently bound hydroperoxyl radical.     

Photochemically bifunctional compound from the class of spironaphthooxazines

Russian Chemical Bulletin -     

Analysis of the phase tunneling time for cold neutrons through a neutron interference filter

Explicit expressions are obtained for the energy dependence of the particle transmission coefficient and phase tunneling time through two rectangular barriers near resonance. The resonance half-width and the phase tunneling time for neutrons in resonance are calculated.     

Recovery of tungsten and cobalt from secondary raw materials by a combined electrochemical and chemical procedure

A combined electrochemical and chemical process was developed for the recovery of tungsten and cobalt from hard alloys of VK grades with the preparation of tungstic acid and cobalt oxalate as intermediates. The subsequent reduction of these intermediates in hydrogen yields metal powders of increased purity.