Togliatti State University (TSU) is a public research university located in Samara Oblast, Russia. It was established on May 29, 2001 as a result of the merger between the Togliatti Polytechnic Institute (founded in 1951) and the Togliatti Branch of Samara State Pedagogical University (founded in 1988). Today, the University is home to over 12,000 students, and more than 67,000 have graduated from it since its founding.
In this study, the evolution of fractal characteristics on the surface and in the bulk of a solid, which have been obtained during uniaxial deformation of copper and nickel, is demonstrated experimentally. The intervals of their mutual linear correlation are established. In addition, in the discussion of experimental results, a hypothesis is proposed, in which a quite unambiguous physical meaning of the fractal dimension as an independent indicator of the degree of strain localisation depending on two physical parameters (average dislocation density and local dislocation density) is formulated.
The results of the study of changes in the microstructure and elemental composition of titanium waveguides made of BT3-1 alloy (Ti—6 Al—2 Sn—4 Zr—2 Mo), which are used for ultrasonic welding of plastic products, are presented. Using a combination of methods, including optical, confocal scanning laser microscopy, raster and transmission electron microscopy, as well as energy-dispersive X-ray microanalysis, the morphology of the surface and the structure of the near-surface layers of the waveguides were studied. The processes of cavitation erosion, which lead to the formation of pores and a regular topography on the contact surface, were identified. In the near-surface layer, the development of the process of grinding the grain structure with the formation of nanosized crystallites (about 50 nm in diameter) with the formation of a surface amorphous layer (about 4 μm thick) enriched with carbon, oxygen, and silicon has been detected. It has been established that these changes are caused by the simultaneous effect of mechanical stress, high-frequency ultrasonic vibrations, local heating, and chemical interaction with the material of the welded parts, including the transfer of plastic components (such as SiO2) into the waveguide material.
Introduction. The challenges associated with the digital transformation of the university en-vironment are becoming increasingly significant in the current context of the growing prevalence of distance and hybrid learning formats. Aim. The present study aims to analyse students' digital commu-nication in both formal and informal educational contexts, as well as to identify its thematic and emo-tional structures based on digital footprints. Methodology and research methods. The research is grounded in systemic and socio-communicative approaches, which enable communication to be understood as a multi-layered socio-pedagogical system. The empirical data comprise over four million messages and comments collected from university online environments, analysed using automated topic and senti-ment analysis tools. Methods from digital linguistics, statistical validation, and case study analysis of university communities were employed. Results and scientific novelty. For the first time, this study identi-fies stable types of digital interaction based on an extensive collection of digital footprints from students at Russian universities. These footprints reflect emotional fluctuations, responses to external events, and characteristics of self-organisation within the networked educational environment. A conceptual model is presented that systematises the levels of university communication-formal, informal, networked, and analytical-as a methodological tool for analysing digital communication. Practical significance. The re-search findings can be applied to the management of university educational environments, the analysis of academic motivation and students' emotional states, and the design of monitoring programmes and support systems for students' digital well-being.
The development of oil fields in the Arctic is associated with high risks of environmental pollution. Increased hydrocarbon production is accompanied by concerns regarding the level of preparedness for potential emergency situations associated with oil spills. The infrastructure in most areas of the Far North does not meet the requirements for the prompt elimination of large-scale environmental pollution arising from oil production activities. The aim of this study was to study the feasibility of using composite sorption materials made from industrial waste to purify water from oil spills at temperatures ranging from-5 to +20 & ocy;C. We studied the physicomechanical properties as the important characteristics of sorbents. Specific surface area of the studied sorbents ranges from 20 to 35 m2/g, density is < 1 cm3/g, porosity is approximately 80-90 %, and mechanical strength is high. The proposed sorbents were shown to possess hydrophobic properties, as evidenced by a high contact angle (130 & ocy;-140 & ocy;) and good buoyancy for 96 hours. The oil sorption time with a purification efficiency exceeding 99.0 % is 20 minutes. The oil absorption capacity of the obtained materials for oil recovery at low temperatures (-5 & ocy;C) ranges from 3 to 22 g/g. A sorbent with magnetic properties was obtained due to the content of ferritized galvanic sludge, significantly simplifying the process of its collection from the water surface. The obtained sorption materials solve the problem of water purification from oil as well as the problem of producing low-cost sorbents from industrial waste such as polyethylene terephthalate, galvanic sludge, and sawdust.
The time profile of the geomagnetically induced current, which is a continuous sequence of unipolar surges of varying duration and amplitude, has been analyzed. Based on this analysis, the duration of the saturation state of the magnetic system of a power transformer during a geomagnetic storm has been preliminary estimated. It has been shown that monitoring geomagnetically induced currents at critical nodes is sufficient to estimate the resilience of an electrical grid to geomagnetic storms. The number of these nodes is determined by the grid topology, the spatial orientation of overhead power lines, and the presence of power transformers with armored or armored-rod magnetic systems at these nodes. It has been shown that monitoring geomagnetically induced currents requires using a direct-amplification current measuring transducer with a Hall sensor. The conversion limit of the measuring transducer should be selected based on the expected long-term geomagnetically induced currents and the level of zero-sequence harmonics in the neutral current with allowance for the power quality indicators at the power transformer connection node.
