Experimental estimate of self-irradiation of building bricks due to incorporated radionuclides

A method is described for experimentally determining the dose rate created in building bricks by incorporated natural radionuclides. It was established using the thermoluminescence dosimetry method that the measured dose rate depends on the detector thickness, the mass of the ceramic product investigated, and the irradiation geometry. The contributions to the measured dose of weakly penetrating α and β radiation and hard ψ radiation are separated, the ratio between them depending on the experimental conditions. Translated from Izmeritel'naya Tekhnika, No. 7, pp. 62–66, July, 1996.     

Making combination drawing methods more efficient by controlling tool microroughness

Results are presented from extensive comparison studies of drawing operations performed with the use of drawplates whose working surfaces have an irregular or regular microroughness. Regularizing the microroughness of the working part of the drawplate makes it possible to control the dimensional accuracy of the resulting products within broad ranges of values.     

Morphological and structural features of polyacrylonitrile fibres spun by the dry-wet method

Conclusions -- A technological regime for the preparation of polyacrylonitrile fibres from binary and ternary copolymers has been chosen; these differ from known specimens in having a more uniform cross-sectional structure and a smoother elementary filament surface.-- A considerable difference in crystalline structure of fibres from binary and ternary copolymers which have been spun into a dimethyl sulfoxide—water bath has been shown.-- Fibres from the binary or ternary copolymer which have been spun into a precipitation bath having a large dimethyl sulfoxide content in water are characterized by a lower degree of swelling.-- Shrinkage of fibres from the binary copolymer in the temperature range 200–220°C is twice as small as the shrinkage of fibres from the ternary copolymer.Deceased.VNIIPV. Translated from Khimicheskie Volokna, No. 3, pp. 19–22, May–June, 1991.     

Mechanical properties and fracture upon static tension of the high-carbon steel with different types of pearlite structure

The hardness and mechanical properties of the U10 steel (1.03 wt % C) with pearlite structures that were formed by isothermal decomposition at temperatures of 650°C (coarse-lamellar pearlite) and 500°C (fine-lamellar pearlite) as well as upon subsequent annealing of fine-lamellar pearlite at a temperature of 650°C for 10–300 min have been studied upon tensile tests. Fractures of the steel with different types of pearlite structure have been examined using scanning electron microscopy. The interrelation between the mechanical properties and the structural features and character of fracture has been analyzed for this steel with pearlite structures differing in the dispersity, morphology, and defect structure of cementite, and in the levels of solid-solution strengthening and microdistortions of the ferrite-constituent lattice.     

Determination of concentrations of fission products by ICP–AES in solutions from spent nuclear fuel reprocessing

A procedure was developed for determining the gravimetric concentration of U and fission products (Ba, Mo, Zr, Sr, Rb, Pd, and Cd) in solutions from spent nuclear fuel (SNF) reprocessing, using inductively coupled plasma atomic emission spectrometry (ICP–AES). The optimum analysis parameters were found. The analytical lines that are not significantly affected by the matrix element were chosen for the elements being determined. The total margin of error in measurements of the metal concentrations (0.1–2500 mg L^–1) by the suggested procedure is in the interval 1–20% (for the minimal concentration). The detection thresholds of uranium fission products in model solutions at optimum parameters vary in the interval from 0.020 to 0.1 mg L^–1.     

Diffusion of hydrogen in hafnium and titanium

We measured the coefficients of diffusion of hydrogen in the hydride phases of hafnium and titanium at 1073–1273°K on the basis of the solutions of Fick's second law for diffusion in a finite cylinder and in a sector of it.Notation C_o initial concentration of gas in the metal, ncm³/cm _Me ³ - C(r,, z, t) instantaneous gas concentration in the finite cylinder - i, k, m, n ordinal numbers (indices) - J_n(_n ⁱr/R) Bessel function of order n - _n ⁱ i-th root of the Bessel function of order n - R,l radius and thickness of the specimen, cm - D diffusion coefficient, cm²/sec - t time, sec - V calibrated volume above specimen, cm³ - F admittance of gas pumping channels, ncm³/sec - dQ_re1/dt rate of gas release, ncm³/sec - p pressure of released gas, torr - dp/dt change in released-gas pressure per unit time, torr/sec - tan tangent of the angle of inclination of the straight line in equation (6), 1/sec - IH₂ ion current of hydrogen - (n) gamma function - W coefficient of variation, % - mean-square deviation - D_o preexponent, cm²/sec - E activation energy, kJ/mole - T absolute temperature of specimens - B universal gas constant, kJ/ deg·mole Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 39, No. 4, pp. 643–648, October, 1980.     

Universal equation of transient plane jet in concurrent stream

An equation is derived and subsequently integrated which is universal not only with respect to velocity of the concurrent stream and initial conditions of jet discharge but also with respect to choice of characteristic scale for the transverse coordinate.Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 43, No. 5, pp. 753–759, November, 1982.     

Stability polyhedra of optimal permutation of jobs servicing

Consideration was given to minimization of the sum of weighted instants of completing servicing of n customers by a single server, provided that the duration of jobs servicing may assume any real value from a given numerical interval. An algorithm of complexity O(n) was developed to construct a polyhedron (parallelepiped) of the optimality of permutation of servicing of n jobs that is contained in the domain of stability of the same permutation and comprises the polyhedron of its stability. For the randomly generated problems, experimental comparison was carried out of the dimensions and relative volumes of the optimality polyhedra and stability of the optimal permutation of servicing n jobs under randomly generated scenarios.     

Tritium-Probe Method in a Study of Adsorption Layers of Lysozyme on the Surface of Detonation Nanodiamonds

Radiochemistry - Tritium-labeled lysozyme was used to determine its adsorption on the surface of nanodiamonds produced by detonation synthesis. It was found that the amount of the adsorbed protein...