Use of Sorbents of Hot-Contact Coal Carbonization in the Power Industry

The many years of experience in the use of sorbents of hot-contact coal carbonization in the power industry is used for substantiation of their prospects for solving problems of power and materials saving and improving the reliability and safety of operation of power equipment. Results of tests of sorbents in systems of water conditioning of thermal power plants, cleaning of return condensates, mazut- and oil-contaminated process wastewaters, makeup water in heat networks, and biosorption cleaning of sewerage are presented. The sorption methods of cleaning are shown to have many advantages, to save expensive ion-exchange resins and reagents, to decrease the cost of desalinated water, and to prolong the service of power equipment. Comparative data are presented for basic commercial kinds of activated carbon and HCCC sorbents (ABD). The technical characteristics of sorbents of hot-contact coal carbonization are shown to be at the level of commercial sorbents or be higher at a much lower cost (by a factor of 2.5 – 3). It is shown that the creation of several HCCC installations with an output of 25 – 30 thousand tons of sorbents a year at coal-fired power plants will solve many water-cleaning problems of the EÉS Rossii Co. (The United Power Systems of Russia) and make it a monopolistic producer of activated carbon in the Russian market.     

Permeability of Lipid Membranes for Atomic Tritium or Atom “Slipping” Effect and Its Role in Tritium Planigraphy

The depth of penetration of tritium atoms capable of isotope substitution, generated by thermal dissociation on a tungsten wire (thermal activation of tritium), into a solid target is considered. On the basis of calculations used in the theory of recoil atom stopping, with a lipid bilayer as example, the possibility of penetration of reactive atoms to a depth of up to 5 nm was demonstrated. This result is nicely consistent with the available experimental data. The possibility of slipping of atomic tritium, without loss of its reactivity, into cavities with a decreased electron density was suggested. This phenomenon should be taken into account when interpreting the results of studying biological macromolecules and their complexes by tritium planigraphy.     

Nuclear Chemical Synthesis of Organic Derivatives of Polyvalent Fluorine

The developed nuclear chemical procedure was applied to prepare previously unknown derivatives of polyvalent fluorine. The procedure involves reaction of tritiated phenyl cations generated by tritium -decay with p-fluorotoluene. The effects of the heteroatom (F, Cl, Br, I) and substituent in the benzene ring of the initial substrate on the yields of the corresponding halonium compounds were examined.     

Synthesis and properties of actinide dimolybdate complexes M<Subscript>2</Subscript>[AnO<Subscript>2</Subscript>(MoO<Subscript>4</Subscript>)<Subscript>2</Subscript>]·H<Subscript>2</Subscript>O (M = Rb,Cs; An = Np,Pu)

New Np(VI) and Pu(VI) dimolybdates Rb₂NpO₂(MoO₄)₂·H₂O (I), Cs₂NpO₂(MoO₄)₂·H₂O (II), Cs₂PuO₂(MoO₄)₂·H₂O (III), and Rb₂PuO₂(MoO₄)₂·H₂O (IV) were synthesized under hydrothermal conditions. The crystal structures of the compounds were determined, and their absorption spectra in the UV, visible, and IR ranges were measured. The compounds crystallize in the monoclinic system. Their crystal structure is based on [AnO₂(MoO₄)₂]_n^2n– anionic layers (An = Np, Pu) formed by (AnO₂)O₅ pentagonal bipyramids and MoO₄ tetrahedra, sharing common vertices. Each An atom in the layer is bonded to other five An atoms via MoO₄ tetrahedra with the formation of a 4343² network. The effect of the ionic radius of the outer-sphere cation on the parameters of the crystal structure and features of the absorption spectra is discussed.     

Optimization of the processes of treatment of materials with supplementation of the definition of unknown random initial characteristics

Consideration is given to the issues of optimization of the processes of treatment of materials with certain unknown initial characteristics. Supplementing of the definition of these unknown parameters can be considered as adaptation of a mathematical model.     

Statistical characteristics of convective exchange in a stationary granular bed

A statistical investigation of local coefficients of convective exchange in a stationary granular bed is made in the range of Re_e = 30–800.Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 51, No. 2, pp. 194–198, August, 1986.     

Mechanism of Pu(VI) and Pu(V) autoreduction in aqueous solutions

Published data on the stability of Pu(VI) and Pu(V) in solutions of mineral and organic acids and their salts are analyzed. The hypothesis that Pu(VI) in acid solutions disappears owing to the disproportionation to Pu(VII) and Pu(V) cannot be accepted because of high redox potential of the Pu(VII)/(VI) couple. Plutonium( VI) is reduced owing to radiation-chemical reactions induced by its α-radiation and to the formation of a dimer (so-called excimer) by an excited Pu(VI) ion with an unexcited Pu(VI) ion, which rapidly decomposes to Pu(V) and H₂O₂. Plutonium(V) disappears owing to disproportionation and radiation-chemical processes.