A comparison of procedures for estimating the impact of nondensable gases on steam condensation taking into account the interaction of power engineering processes in the primary circuit of a nuclear power installation

We consider two procedures for evaluating the influence of nondensables on steam condensation taking into account the integral effect from interaction between the water-chemistry and thermal-hydrodynamic processes occurring in the primary coolant circuit of a nuclear power installation (NPI). Results from calculations of the passive safety system of an NPI are given.     

Glass crystal materials made from mineral and technogenic feedstock from Karelia

Facing and decorative glass crystal materials were developed from mineral feedstock and technogenic wastes. The effect of the components present in the mineral feedstock in liquation and crystallization of the glasses was investigated. The materials obtained can be used in construction for facing walls.     

Effect of pulse duration and size of interelectrode interval on electric-spark spraying. I. Effect of pulse duration and size of interelectrode interval on rate of electric-spark transfer

The influence exerted by electric-spark spraying on the kinetics of mass transfer and the physicomechanical properties of coatings is investigated. It is shown that electric-spark spraying is determined by the dynamic properties of the cathode jets, which depend on the electrical parameters of the spark discharge, the size of the interelectrode interval, and the physical properties of the coatings, which vary during spraying.     

X-ray diffraction study of the structure of Al-Ni melts

The structures of Al-Ni melts with 0, 10, 18, 25, 28, 32, 40, 75, 90, and 100 at % Ni are studied by X-ray diffraction. The structural models of the melts, which were analyzed by the Voronoi-Delaunay transformation method, are reconstructed by a procedure that is inverse to the Monte Carlo method using experimental structure-factor curves. The parameters characterizing atomic ordering at short and longer distances are determined to change nonmonotonically in the range 10–40 at % Ni with an extreme in the vicinity of the melt containing 28 at % Ni. In this concentration range, nickel atoms are predominantly located in the pentagonal rings of polytetrahedral clusters of the icosahedral type; these atoms are ～4.1 Å from each other. Such clusters generate a prepeak in the structure-factor curves of the melts in the range 10–40 at % Ni.     

Effect of saturation parameters on the interaction of titanium alloys with carbon-nitrogen-containing media

We study some specific features of phase formation and gas saturation in the course of chemical and thermal treatment of VT1-0, OT4, and VT14 titanium alloys in carbon-nitrogen-containing (graphite and nitrogen under atmospheric pressure) and nitrogen-containing (molecular nitrogen under atmospheric pressure) media. Saturation was carried out at 750–1100°C, and the time of isothermal holding was 5 or 20 h. We have shown that, irrespective of the composition of the saturating medium, within the range 750–1000°C, the phase composition of coatings is identical and consists of TiN and Ti₂N nitrides. The quantitative proportions between them depend on the temperature and time of treatment. Owing to the specific features of the composition of a carbon-nitrogen-containing medium, the depth of the diffusion sublayer increases, and the stoichiometry of cubic nitride decreases, which leads to an increase in the surface microhardness of nitride coatings. Carbonitride coatings are formed only at high saturation temperature (1100°C). Their maximum hardness is 2.5 GPa higher than that of nitrides formed under similar conditions.Translated from Fizyko-Khimichna Mekhanika Materialiv, Vol. 40, No. 3, pp. 81–87, May–June, 2004.     

Photosensitive structures based on ZnIn<Subscript>2</Subscript>Se<Subscript>4</Subscript> single crystals

Photosensitive structures of surface-barrier and homojunction types have been fabricated for the first time on the basis of ZnIn₂Se₄ single crystals. The spectral dependence of the quantum efficiency of photoconversion has been studied and discussed. It is concluded that the structures are promising for commercial applications.     

Methods of rotating stall and surge detection in centrifugal compressors

Systems for prevention of surging of centrifugal compressors and methods of rotating stall detection and early surge diagnosis using statistical processing of sensor signals of various parameters, i.e., the method of calculation of the correlation function of the signal and the method of calculation of signal dispersion, are discussed. The results of routine tests of air and high-speed air centrifugal compressors and their detachable flow parts are adduced. __________ Translated from Khimicheskoe i Neftegazovoe Mashinostroenie, No. 6, pp. 30–33, June, 2006.     

Results of familiarization of and prospects for a procedure for the burning of wastes in a vortical fluidized bed

Problems that have arisen during tune-up of the production line for the thermal processing of solid household waste by the method of burning in a vortical fluidized bed (principally, a new technology for Russia), and means of their solution are presented. Investigative studies are cited. __________ Translated from élektricheskie Stantsii, No. 6, pp. 20–26, August, 2006.     

Strain waves in colliding bars having nonparallel faces

The paper reports the experimental investigation data for the effect that nonparallel faces of bars under impact exert on the parameters of longitudinal and bending strain waves generated in the bars. The changes in stress magnitudes in the bar under impact with growing angle of the impact faces offset are described. __________ Translated from Fiziko-Tekhnicheskie Problemy Razrabotki Poleznykh Iskopaemykh, No. 6, pp. 73–78, November–December, 2006.     

Internal friction and brittle-ductile transition in structural materials

The temperature dependences of internal friction (ultrasound decrement) and impact toughness of bcc metals (Fe-12Cr-W-V-Ta-B-C ferritic/martensitic steel, V-4Ti-4Cr vanadium-based alloy) have been studied in a temperature range from 100 to 300 K. The acoustic and mechanical characteristics exhibit correlated variation. The use of nondestructive acoustic techniques for the investigation of mechanisms of the brittle-ductile transition in metallic structural materials is experimentally justified.