Technical Physics Letters

Bakhadyrkhanov, M. K.; Iliev, Kh. M.; Mavlonov, G. Kh.; Ibodullaev, Sh. N.; Tachilin, S. A.

doi: 10.1134/s1063785022010023pmid: N/A

The negative magnetoresistance in silicon containing nanoclusters of manganese atoms is highly sensitive to various external effects. We determined the regularities of the change in the negative magnetoresistance in silicon containing nanoclusters of manganese atoms depending on temperature, illumination, and electric and magnetic fields. A new class of multifunctional sensors of physical quantities can be developed based on a single silicon crystal containing nanoclusters of manganese atoms.

Deryugin, E. E.; Bogdanov, A. A.

doi: 10.1134/s1063785022010035pmid: N/A

We have proposed a procedure for the experimental determination of the specific fracture energy of a material under loading by a three-point bending of a rectangular sample with a chevron notch. At the initial stages of crack propagation in the chevron notch zone, a linear dependence of the sample compliance on the crack length is observed. This makes it possible to calculate the specific fracture energy of a material without using the phenomenological equations used under standard test conditions. The calculations were carried out for VT1-0 technical titanium.

Gutkin, M. Yu.; Orlova, T. S.; Skiba, N. V.

doi: 10.1134/s1063785022010047pmid: N/A

A theoretical model is proposed that describes the mechanism of dissolution of pores at grain boundaries in ultra-fine-grained materials during long-term annealing. Within the framework of the model, the dissolution of a pore occurs due to the emission of vacancies and the climb of grain-boundary dislocations along the grain boundary to the pore. It is shown that in this case a significant decrease in the total energy of the system occurs. The results of the model are in good agreement with the available experimental observations of pore dissolution during annealing of an ultra-fine-grained Al–Zr alloy.

Samokhvalov, V. N.

doi: 10.1134/s1063785022010059pmid: N/A

This paper discusses a study of air-temperature variation along the expansion chamber axis in zones of the nozzle inlet and flow swirler in direct-flow, counterflow, three-flow, and single-flow vortex tubes. It is established that, in all cases, air cooling in the vortex tube occurs in the zone of the swirling device, while its heating occurs in the zone of flow unwinding. The change in the air temperature in the axial zone along the expansion chamber appears due to heat exchange between the heating and cooling zones.

Volosnikov, D. V.; Povolotsky, I. I.; Skripov, P. V.

doi: 10.1134/s1063785022010060pmid: N/A

In experiments on pulse heating of a probe in solutions of various nature, it is established that there is a correlation between the heat conduction of the solution and its mixing volume. The results obtained are consistent with the data indicating the appearance of an additional (relative to the additive values) thermal resistance in the liquid when the second component is added to it. The experiments are carried out with significant expansion of a range of values of the mixing volume and temperature, including not fully stable states, that are short-term superheated relative to the liquid–vapor and/or liquid–liquid equilibrium temperature of the solution.