The influence of modification by superdispersed powders on the lead-tin-base bronze structure

The paper presents data on the influence of additives of the pre-treated aluminium oxide powder on the structure of cast lead-tin-based bronzes. Different quantities of the modifier, based on the superdispersed aluminum oxide powder, were added to the bronze melt. The studies have shown that addition of a small amount of aluminum oxide powder (0.07... 0.25 %) allows modifying the micro structure of the obtained castings. This modification includes grain refinement, reduction of the matrix dendrites size of tin solid solution in copper, as well as formation of spherical inclusions of the low-melting phase - lead. In this case, the addition of such modifier influences weakly the morphology and the quantity of solid eutectoid inclusions based on electron compound Cu[31] Sn[8]

Entropy Production and Luminosity-Effective Temperature Relation for Main-Sequence Stars

Based on the maximum entropy production principle, a relation between luminosity and effective temperature for main-sequence stars is obtained. Simplicity of the derivation and absence of any empirical parameters in the result is a fundamental difference of the present method from the classic ones where equations of stellar structure are analyzed. Using available photometric data (Webda, GCG) for more than 7.5 thousand stars, it is shown that the obtained luminosity-temperature relation is better than previously used ones.Comment: 9 pages, 4 figure

Principle of Least Effort and Sentence Length in Public Speaking

The analysis of sentence lengths in the inaugural speeches of US presidents and the annual speeches of UK party leaders is carried out. Transcripts of the speeches are used, rather than the oral production. It is discovered that the average sentence length in these speeches decreases linearly with time, with the slope of 0.13 ± 0.03 words/year. It is shown that among the analyzed distributions (log-normal, folded and half normal, Weibull, generalized Pareto, Rayleigh) the Weibull is the best distribution for describing sentence length. These two results can be considered a consequence of the principle of least effort. The connection of this principle with the well-known principles of maximum and minimum entropy production is discussed. © 2021 by the authors. Licensee MDPI, Basel, Switzerland

Formation of high-carbon abrasion-resistant surface layers when high-energy heating by high-frequency currents

The paper shows the possibility of carburization of low-carbon steel surface layers using high-frequency currents. The mathematical modeling of carburization using high-energy heating by high-frequency currents (HEH HFC) has been carried out, the temperature fields formed during the given processing have been calculated, as well as the structural changes in the surface layers have been simulated. The features of the structure formation in the surface layers of low-carbon steel after carburizing via HEH HFC have been determined by optical and scanning microscopy, which is confirmed by the computational models. The rational mode of fusion via HEH HFC has also been determined (power density of the source q[s]=(1.5...4.0)•10{8} W m{-2}, (the relative travel speed of parts V[p]=5 ... 100 mm /sec), with forming the compressive retained stresses in the surface layer ([sigma][RS]=-300...-400 MPa)

Entropy Production of Stars

The entropy production (inside the volume bounded by a photosphere) of main-sequence stars, subgiants, giants, and supergiants is calculated based on B–V photometry data. A non-linear inverse relationship of thermodynamic fluxes and forces as well as an almost constant specific (per volume) entropy production of main-sequence stars (for 95% of stars, this quantity lies within 0.5 to 2.2 of the corresponding solar magnitude) is found. The obtained results are discussed from the perspective of known extreme principles related to entropy production

Entropy Production of Main-Sequence Stars

The entropy production (inside the volume bounded by a photosphere) of main-sequence stars is calculated based on B–V photometry data. The entropy-production distribution function and the dependences of entropy production on temperature and luminosity are obtained for these stars for the first time. A very small range of variation of specific (per volume) entropy production discovered for main-sequence stars (only 0.5 to 1.8 solar magnitudes) is an interesting result that can be crucial for understanding thermodynamic processes of stars

Temperature evaluation of a hyper-rapid plasma jet by the method of high-speed video recording

In this paper the procedure of comparative evaluation of plasma temperature using high-speed video filming of fast processes is presented. It has been established that the maximum plasma temperature reaches the value exceeding 30 000 K for the hypervelocity electric-discharge plasma, generated by a coaxial magnetoplasma accelerator with the use of the 'Image J' software

Environmental education for sustainable development in Russia

The article is devoted to one of the crucial aspects of sustainable development, with the example of analyzing the possibilities for the development of environmental education in the Russian Federation. The article analyzes the possibilities of the current Russian Federal State Educational Standard for general and higher education in implementing the ideas of education in the interests of sustainable development. The methodological principles and philosophical foundations of environmental education are considered to designate the worldview guideline of ecological thinking. The tasks of the state educational policy of the Russian Federation in the field of environmental education and the implementation of the concept of sustainable development are considered. The article describes the representation of the concept of sustainable development in the state policy of the Russian Federation, in the field of environmental education in the requirements of the Federal State Educational Standard for various subject areas and training courses related to the topic of environmental development in school and university education. The strategic goal of environmental education in Russia is the formation and development of an environmental outlook among students of all ages, which is based on scientific knowledge, environmental culture, and ethics. The continuity, basic principles, and trends of the implementation of environmental education in the Russian Federation are shown. © 2020 by the authors

Fabrication of the Ni[3]Al-based alloy formed by spark plasma sintering of VKNA powders

The material based on Ni[3]Al intermetallic has been obtained from the industrial powder of a VKNA type by the method of spark plasma sintering. Materials sintering was conducted at the temperature of 1100 °С, compacting pressure of 20 MPa, and during soaking time equal to 5 minutes. The heating rate of samples amounted to 50 and 200 °С/min. It has been established that the material obtained by sintering at the rate of 50 °С/min possesses a maximum value of density (5.93 g/cm{3}) and a maximum level of bending strength (~ 400 MPa)

Investigation of the structure and microhardness of Mo-Fe-C coatings obtained by the electron beam injected in the atmosphere

In this work 'Mo-Fe-C' coatings fabricated on medium carbon steel by non-vacuum electron beam cladding were investigated. The structure of coatings and transition zones were studied by scanning electron microscopy (SEM). It was shown that an increase of Fe percentage in the cladding mixture led to a decrease of the eutectic volume fraction in the coating and was accompanied by the formation of the gradient structure between the coating and a substrate material. Measurements of microhardness in the cross section of samples revealed that the cladding of a 'Mo-C powder mixture contributed to a 4.5-fold increase of microhardness