Heat treatment and durability of punching dies

Conclusion Quenching of 7KhG2VM dies in air from 860°C produces minimal distortion and substantially increases the durability.Translated from Metallovedenie i Termicheskaya Obrabotka Metallov, No. 2, pp. 62–63, February, 1968.     

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.     

Hydraulic resistance of plane channels and annulus with different roughness on opposite walls

A new method for prediction of hydraulic resistance for a turbulent flow in plane channels and annulus is proposed. In spite of the importance of this issue, only very few publications devoted to the investigation into hydrodynamics in these channels are available, and there are no methods for predicting hydraulic resistance of a flow in these channels at all. The flow in channels with different roughness on the walls is described using the Prandtl semiempirical theory of a turbulent boundary layer. The flow in a channel cross-section is divided into two noninteracting layers of different thickness flowing along the walls with different roughness. The basic balance correlations are derived for a plane channel. To match the velocity profiles of both layers at the interface point, a logarithmic velocity profile is used. This yields a closed system of equations for predicting hydraulic resistance in plane channels with a given different roughness on opposite walls. It is demonstrated that the obtained correlation may be used for predicting hydraulic resistance in annulus as well. Experiments were carried out with a water flow in an annulus. Each annuli consisted of a pipe having a smooth wall into which a rod with artificial roughness on the surface was inserted coaxially. Two types of roughness were investigated: trapezoid and threadlike ones. Comparison of the predictions with the experimental data confirmed the validity of the proposed method. It can be used in designing flowpaths of various power installations.     

Oxidation of Am(III) to Am(IV) with ozone in solutions of heteropolyanions

Oxidation of Am(III) in the presence of K₁₀P2W₁₇O₆₁ and K₈SiW₁₁O₃₉ (L) at 20dGC was studied by spectrophotometry. Am(III) is oxidized with ozone to Am(IV) only in the pH range 3.5–1.0. In the case of formation of a complex with Am: L = 1: 1, the reaction is approximately first-order with respect to the metal, and its rate decreases with a decrease in pH from 3.5 to 1.0. Am(IV) in solution in the presence of ozone is slowly reduced with products of water α-ray radiolysis, predominantly with ?₂?₂. The rate constant of the reaction of Am(IV) with ?₂?₂ was estimated.     

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.     

Coprecipitation of Pu(IV) with Fe(III) and Cr(III) hydroxides from nitrate-acetate solutions under hydrothermal conditions simulating deep disposal of liquid radioactive wastes

Precipitation of Fe(III), Cr(III), Ni(II), and Mn(II) from nitrate-acetate solutions and coprecipitation of Pu(IV) with Fe(III) and Cr(III) were studied. The degree of precipitation of 80–95% is attained for Fe(III) at 95–200°C and pH>0.5–0.6, and for Cr(III), at T=95°C and pH≥4.0 or T=200°C and pH≥1.0. The phase composition of the precipitates formed by thermal hydrolysis of iron nitrate in model solutions was analyzed. Depending on pH and temperature, the solid phase contains various modifications of Fe₂O₃, FeOOH, and amorphous phases. Noticeable coprecipitation of plutonium from nitrate-acetate solutions is observed at pH≥4, and it is incorporated in the precipitate only at formation of FeOOH. No coprecipitation of Pu(IV) with Fe₂O₃ was found. Under the given experimental conditions, plutonium in aqueous solutions occurs in the oxidation state +4 forming monoacetate (or, probably, hydroxo acetate) complexes.