Corrosion of M1 copper in an aqueous ethylene-glycol heat carrier under conditions of heat transfer

We have proposed an equation for calculating the mean temperature of the wall of a copper channel depending on the heat-flux density and solution velocity in the channel. We have assumed that the formation of corrosion products on copper and in the solution includes reactions leading to the appearance of complex compounds of copper with components of the solution as well as of solvated and desolvated oxides, and the shift of dynamic equilibrium in these reactions depends on the temperature of the copper surface. Under conditions of the ion-exchange purification of 66% ethylene-glycol solution, the coefficient of protective action (Z) decreases with increase in the heat-flux density and the corresponding growth of the temperature of the copper surface. A decrease in the rate of copper dissolution (Z > 40%) can be reached in 66% ethylene-glycol solution with a specific electric resistance of 25 kΩ·m and a concentration of dissolved oxygen of 0.9–1 g/m³. __________ Translated from Fizyko-Khimichna Mekhanika Materialiv, Vol. 41, No. 5, pp. 41–48, September–October, 2005.     

Low-Temperature Heat Capacity and Thermodynamic Functions of AlH3 and AlD3

The thermodynamic properties of AlH₃ and AlD₃ were evaluated from low-temperature heat capacity measurements. For -AlH₃, C ⁰ _p (298.15 K) = 41.14 ± 0.13 J/(mol K), S ⁰(298.15 K) = 30.62 ± 0.14 J/(mol K), H ⁰(298.15 K) – H ⁰(0) = 5527 ± 15 J/mol, and ⁰(298.15 K) = 12.08 ± 0.06 J/(mol K). For -AlD₃, C ⁰ _p (298.15 K) = 50.82 ± 0.04 J/(mol K), S ⁰(298.15 K) = 36.74 ± 0.12 J/(mol K), H ⁰(298.15 K) – H ⁰(0) = 6801 ± 10 J/mol, and ⁰(298.15 K) = 13.93 ± 0.04 J/(mol K).     

Surface hardening of steel by vacuum diffusion chromizing

Vacuum diffusion chromizing was studied as a method of increasing fatigue strength and the corrosion and erosion resistance of steel. It was shown that carbon steels chromized by this method can be used in place of stainless chromium-nickel steels.     

Wide-aperture plasma jet source based on low-voltage spark discharge with ferroelectric electrode

Low-voltage vacuum spark discharge initiated at a storage capacitor voltage of 75–600 V using a metal grid cathode situated on the front surface of a polarized ferroelectric (FE) electrode has been experimentally studied. The discharge was initiated when a control voltage pulse with an amplitude of 1 kV and a duration of 100 ns at only negative polarity was applied to the rear FE surface (irrespective of the direction of its polarization vector). Optical measurements showed that the emitting surface area on the cathode increases approximately in proportion to the discharge voltage. According to the collector measurements, the ion plasma flux has slow and fast components, the velocities of which remain almost constant when the discharge current amplitude varies in a wide interval.     

Evaluation of reactivity and immunogenicity of a cultured concentrated inactivated vaccine against hepatitis A "Hep-A-In-Vak"

Clinical trials of inactivated hepatitis A vaccine Hep-A-in-Vac demonstrated its specific safety and moderate reactogenicity, manifesting by short-term fibrillar twitching of musculus deltoideus at the site of injection. After a course of three immunizations 87.5% seronegative vaccines developed a high level of specific antibodies to hepatitis A virus with at least 100 reverse values of titers. In controls antibody titers remained seronegative in 90% cases. These data indicate evident immunologic activity of Hep-A-in-Vac vaccine.     

Complex of Computational-Methodological and Experimental Studies of the Motion of a Rotor on an Ultramagnetic Suspension

The results of computational-methodological and experimental studies of the motion of a rotor on an electromagnetic suspension are presented. Analytical methods and computer calculations are used to study nonlinear models. Experimental data are obtained for passage of the characteristic flexural resonance frequency. The investigations reveal the important factors in an electromagnetic suspension, illustrate their manifestation, and yield data to be taken into account in design work for a turbomachine in a nuclear power plant with a 100 tons vertical rotor. __________ Translated from Atomnaya Energiya, Vol. 99, No. 1, pp. 26–33, July 2005.