A Relation Between the Flow Density and Flame Length in the Work Space of the Bath Smelting Furnace

The article provides mathematical modelling results of radiation flow formation in the work space of the smelting (glassmaking, open-hearth) furnace with different heating patterns and flow distribution over the surface of the bath and enclosing structures. A significant influence of the flame length upon technical and economic parameters of furnace operation was found out. Keywords: bath smelting furnace, glass-melting furnace, mathematical modelling, flame length, radiation flows, temperature fiel

Особенности строения биомедицинских сплавов Ti-Nb, полученных электродуговой плавкой и селективным лазерным сплавлением

Выявлено, что при электродуговой плавке и селективном лазерном сплавлении в сплаве Ti-Nb имеет место ликвация компонентов. На участках, обогащенных Nb образуется [beta]-фаза, на участках, обедненных Nb - [alpha]''-фаза. Для устранения неоднородности фазового и элементного состава рекомендуется повысить содержание Nb в сплаве до 45 мас. %

Optical generation in an amplifying photonic crystal with metal nanoparticles

We show the possibility of selective polarization generation in photonic crystal structure with the monolayer of metal nanoparticles. Optical properties of the monolayer are defined by the surface concentration and shape factor of the nanoparticles. Wavelength dependence of the monolayer reflectance and transmittance possesses a resonance behavior resulting from plasmon resonance in nanoparticles. We show that this allows, depending on the relative orientation of the monolayer anisotropy axis and the polarization direction of the light, to achieve the mode discrimination of the photonic structure.This work was supported by the Ministry of Education and Science of the Russian Federation (grant numbers 14.Z50.31.0015, 3.5698.2017/9.10, 3.8388.2017/ITR) and the Russian Foundation for Basic Research (Projects Nos. 17-02-01382)

Thermal and Physical Properties of Methane Family Hydrocarbon and Oxygen Combustion Products in State-of-the-Art Arc Steel Furnace

The work deals with the particular combustion characteristics of methane family hydrocarbons (methane, ethane, propane, butane) and wet natural gas with process oxygen at carbon dioxide and water steam dissociation in a state-of-the-art arc steelmaking furnace. An algorithm is developed to calculate chemistry, the amount and concentration of combustion products at carbon dioxide and hydrogen dissociation, their physical and thermophysical parameters; heating power, balance and actual temperature, heat and pyrometric factors are evaluated considering heat transfer by radiation into unbounded medium. Based on the calculation results the recommendations are given for development of cold charge material heating conditions in order to minimize dusting, carbon oxide and hydrogen and charge material loss. © Published under licence by IOP Publishing Ltd

ANTI-CRISIS SOLUTIONS FOR THE DEVELOPMENT OF SMALL AND MEDIUM-SIZED BUSINESSES AS A FACTOR IN IMPROVING THE ECONOMIC SECURITY OF THE STATE

The article presents anti-crisis measures to support small and medium-sized businesses implemented by the  Government of the Russian Federation in the COVID-19 pandemic. The paper reviewed also the foreign experience  of using measures to support small and medium-sized businesses in the context of the spread of a new coronavirus infection and proposed measures to improve the effectiveness of anti-crisis programs to support small and medium-sized businesses during the spread of coronavirus infection. The authors used in this article the following research methods: analysis and generalization of Russian and foreign anti-crisis measures. The study proposed, based on this analysis, measures to improve the effectiveness of anti-crisis programs to support small  and medium-sized businesses during the spread of coronavirus infection in the Russian Federation

Efficiency analysis of state support measures for the small and medium-sized business sector in Russia during the pandemic

A comprehensive analysis of legal and economic measures aimed at state support for small and medium-sized businesses during the COVID-19 pandemic is presented, as well as the relevant regulatory legal acts regulating certain aspects of credit anti-crisis support are studied in detail. Conclusions are presented on the state of the small and medium-sized business sector based on statistical data during the crisis period, and specific negative trends associated with the impact of the pandemic are highlighted. The emphasis is made on a detailed study of foreign experience in the field of anti-crisis measures to support small and medium-sized businesses. Within the framework of the article, such scientific research methods as analysis and generalization were used. It was noted, on the one hand, the high efficiency of anti-crisis support programs, on the other, its problems, including limited and insufficient budget funding

The Application of Schematic Compensation Technique for Increasing of Radioelectronic Devices Reliability

The schematic method development of radiation degradation compensation of operating amplifiers’ input currents and offset voltages on basis of radiation-sensitive parameter degradation research of integral microcircuits and discrete transistors is presented and experimentally verified

Effect of Mesenchimal Stem Cells on Apoptosis Indices in Renal Parenchyma during Experimental Stress

Background. Kidneys are extremely sensitive to various environmental factors. Stress disturbs prooxidant-antioxidant balance, causes hyperproduction of reactive oxygen species, changes activity of the nitroxidergic system components, regulating apoptosis. The use of mesenchymal stem cells can normalize functioning of damaged organs in the pathological process.Aim: to assess the effectiveness of mesenchymal stem cells in a single 24-hour immobilization according to the dynamics of apoptosis indices in renal tissue – nitric oxide (NO) and fragmented DNA.Materials and methods. The study included male nonlinear white rats aged 3 to 4 months and weighing 225 ± 25 grams. Experimental stress was modeled by the immobilization of animals in the fixation chambers within 24 hours. The efficacy of cell therapy was determined by the change in the concentration of the tested substances at 1, 3, 7, 14, 21 and 30 days of the experiment.Results. There was a sharp increase in the total amount of nitrates / nitrites and the level of DNA fragmentation in the homogenates of the renal parenchyma after the action of an acute stressor, which may indicate the induction of apoptosis. It was proved that in animals, receiving mesenchymal stem cells as a treatment, the restoration of the studied parameters in the kidney tissue was significantly accelerated in comparison with the controls values.Conclusion. Mesenchymal stem cells protect cells from self-destruction and activate reparation, which makes them promising for further study

Static Solitons of the Sine-Gordon Equation and Equilibrium Vortex Structure in Josephson Junctions

The problem of vortex structure in a single Josephson junction in an external magnetic field, in the absence of transport currents, is reconsidered from a new mathematical point of view. In particular, we derive a complete set of exact analytical solutions representing all the stationary points (minima and saddle-points) of the relevant Gibbs free-energy functional. The type of these solutions is determined by explicit evaluation of the second variation of the Gibbs free-energy functional. The stable (physical) solutions minimizing the Gibbs free-energy functional form an infinite set and are labelled by a topological number Nv=0,1,2,... Mathematically, they can be interpreted as nontrivial ''vacuum'' (Nv=0) and static topological solitons (Nv=1,2,...) of the sine-Gordon equation for the phase difference in a finite spatial interval: solutions of this kind were not considered in previous literature. Physically, they represent the Meissner state (Nv=0) and Josephson vortices (Nv=1,2,...). Major properties of the new physical solutions are thoroughly discussed. An exact, closed-form analytical expression for the Gibbs free energy is derived and analyzed numerically. Unstable (saddle-point) solutions are also classified and discussed.Comment: 17 pages, 4 Postscript figure