Electroacoustic coating application to improve the performance of composites based on heat-resistant nickel alloys

Optimization of the application of electroacoustic coatings is considered, taking account of their structure, properties, and environmental impact.     

Evaluation of the antiwear properties of transmission oil with nanoscale powder additives

Comprehensive pilot studies of the influence of one- and two-component nanodimensional powder additives on the operational properties of transmission TM-3-18 oil (GOST (State Standard) 23652-79 TAP-15V) are implemented. Introduction of nanopowder tin bronze and aluminum oxide additives into the base oil is found to increase the antifriction, antiwear, and antiwelding properties of the latter, as well as the cogwheel durability of units, which limits the service life of tractor transmission equipment.     

Thickening of Petroleum Systems. Communication 1

The behavior of oils thickened with atactic polypropylene (APP) at low temperatures is examined. The positive effect of a crystalline phase in APP on the viscosity-temperature properties of thickened oils at low temperatures is demonstrated. __________ Translated from Khimiya i Tekhnologiya Topliv i Masel, No. 5, pp. 39 – 41, September – October, 2005.     

Acoustic Modes and Momentum Relaxation in 2D Atomic Hydrogen on Helium Surface

Seeking for manifestations of superfluidity in 2D spin-aligned atomic hydrogen (H↓) adsorbed on the surface of liquid helium at T∼0.1 K we consider possible acoustic modes in this 2D Bose gas depending on frequency and on characteristic times of energy and momentum transfer. At high frequencies, the analogues of ordinary and second sound are realized in 2D H↓. At low frequencies, the 2D analogue of the fourth sound is realized: the normal component of hydrogen and ripplons are immobile and only the superfluid component of hydrogen participates the oscillations. We also estimate the rate of momentum relaxation between superfluid hydrogen and ripplons, τ _HR⁻¹ ∝ T ^13/3. The most promising for observing the superfluidity in 2DH↓ is the fourth sound, which could be excited, e.g., by ESR.     

Extending the service life of insulation systems through the use of chemically active components

The effect of ageing on the performance of insulation systems is studied. A program has been developed that determines the residual life of polymeric insulation taking into account all of the factors affecting the insulation’s state. Experimental data on the effect of the chemically active components of the substance adsorbed in the insulation microflaws and the effect of the epoxy oligomer on polyarylates during production are presented. A way to remove the structural and production flaws facilitating the active ageing process is considered.     

Clock Shift and Interstate Coherence of?Multi-Level Atoms

In contrast to two-level atoms, the interstate coherence of both three-level bosons and fermions contributes to the collisional frequency shift of internal transitions in a cold homogeneous gas. In particular, the measured contact shift of the b?c (a?d) hyperfine transition in 3D atomic hydrogen in the presence of incoherently populated state a (b) yields the difference a _t ?a _s =30(5)?pm between the triplet and singlet s-wave scattering lengths, which is a factor of 2 smaller than the previous result. The dynamic contact shift of the b?c resonance due to the Rabi oscillations between the coherently populated states a and b under the simultaneous continuous excitation of the a?b transition can explain the low-temperature electron-nuclear double resonance spectra of 2D hydrogen. The role of field inhomogeneity, spin diffusion, relaxation and recombination is discussed.     

Glycerol as a ligand for the laser-induced liquid phase deposition of copper

In the present paper, the use of glycerol as a ligand in the process of the laser-induced liquid phase deposition of copper onto oxide glass is studied. It is shown that the process proceeds without an undesirable gas evolution, leading to the deposition of extended continuous copper structures with a good topology on the glass surface.     

Groupcast routing with the possibility of choosing a channel transmission method

Consideration was given to the following statement of the problem of groupcast routing in the wireless multihop network: in the class of tree-like routes, it is required to determine a minimal-cost route calculated with account for the transmission method used by the MAC protocol. If this method takes advantage of the broadcast nature of the wireless medium, then the number of attempts of transmission made by a route retransmitter and their cost depend on the retransmitter neighbor nodes on the route. This peculiarity makes the considered groupcast routing problem sufficiently distinct from the classical Steiner tree problem. The sensitivity of the route cost to the transmission methods used was analyzed. Also a number of the groupcast routing algorithms were proposed which allow for the structure of the transmission methods and enable one to reduce the cost of routes.     

Microwave device for liquid dielectrics diagnostics

It is developed a method for measuring of dielectric permittivity of liquid dielectrics. High accuracy and reliability of the method is provided by definite hardware realization; it is used resonance-bridge method; to provide high stability of measuring SHF-signal frequency there is used self-excited oscillator on a basis of active running wave resonator.     

Electrical properties of MgO-MnO materials

The resistivity of MgO-MnO materials was measured in the temperature range from 290 to 670 K. The materials were found to bep-type, with a negative temperature coefficient of resistance.