Activation of metal oxidation over the zone of electrodiffusion

It is shown that an oxide layer saturated by chromium oxides is formed on the surface of chromium steel at a higher rate under electrocontact (10⁴–10⁵ A/cm²) vacuum dc annealing (10^–2 Torr, 300°C) than under furnace heating. Such activation of oxidation is due to the formation of an electrodiffusion zone in the surface steel layer. At further stages, grain boundaries emerge to the metal surface that act as oxidant transportation channels from the surrounding medium into the conductor bulk, which results in accelerated oxide formation in the bulk of the surface metal layer. Apart from the uniform oxide layer, individual hematite nanoflakes and nanoleaves with the thickness of 50–40 nm and average diameter of 450 nm are formed on the positive electrode and grow vertically on the steel surface. The average surface density of nanoparticles is 10⁸ 1/cm². Such activation of metal oxidation over the zone of electrodiffusion can provide pronounced properties for accelerated formation of protective surface layers, in addition to its intrinsic functional (sensor, catalytic, semiconductor, adsorption) properties.     

A method of measuring and recording the pressure of a granular medium

Translated from Khimicheskoe i Neftyanoe Mashinostroenie, No. 4, pp. 27–28, April, 1992.     

Population migration and the epidemic situation of parasitoses in Belgorod Province]

Paper summarized a concise evaluation of short wounds according to the Red Cross Classification published in Geneva. It is supposed to attract the forensic physician's attention due to informative purpose.     

Unique features of heat exchange for spherical particles in a concentric cavity

Exact and general solutions are obtained for the problem of radiant heat exchange of a sphere in a cavity. Radiation effects in such a system are analyzed.Translated from Inzhenerno-fizicheskii Zhurnal, Vol. 60, No. 4, pp. 615–620, April, 1991.     

A Multichannel TEA N2 Laser for Visualizing Pulsed Plasma in the Nanosecond Range

The choice of a UV nanosecond TEA N₂ laser ( = 337 nm, _l 3 ns) for the multiframe probing of a dense pulsed plasma is justified and the influence of elements of its structure on the lasing efficiency is considered. The parameters of laser radiation were studied under various conditions of the formation of a space discharge and the methods for increasing the energy deposition were analyzed. Based on an optimized design of the laser module, a multichannel light source with a simple design has been built that allows all the channels to be triggered from a common spark gap and ensures the flexible changing of pulse delays within a range of t = 1–100 ns.     

Formation of the two-dimensional image edge in two diffraction orders in the process of triple Bragg diffraction

The possibility of formation of the edge of a 2D optical image in two diffraction orders by means of Fourier processing with the use of triple Bragg diffraction is proposed and confirmed experimentally. A new model of 3D acousto-optic interaction in a gyrotropic crystal is developed, and transfer functions are calculated. The theoretical results of image processing are confirmed experimentally using triple Bragg diffraction in a TeO₂ crystal.     

Pyrolytic densification of porous carbon-carbon composite materials

This paper examines the densification of the pore space of a carbon-carbon composite material through methane pyrolysis at a reduced pressure and the dynamics of the pyrolytic saturation process. The morphology and microstructure of the pyrolytic carbon are compared to those of the main components of the parent carbon-carbon composite material. The composite is characterized by hardness tests before and after the pyrolytic densification of the carbon matrix.     

The Formation of Spherical and Tree Particles during Diamond Growth by Chemical Vapor Deposition

Protection of Metals and Physical Chemistry of Surfaces - A model is proposed for the formation of spherical and treelike particles during the growth of diamond films by chemical vapor deposition...