Analyzing the Operational Materials on Crack Formation in Blades of Francis Turbines at the Krasnoyarsk HPP

Equipment of the Krasnoyarsk HPP is considered as an example to analyze the dependence of crack formation in runner blades on the operating conditions of t     

Determination of the parameters of atmospheric gas clouds by radar methods at frequencies in the rotational spectrum

An analysis is made of a method of determining the parameters and coordinates of atmospheric gas clouds radar systems which can measure the attenuation of electromagnetic radiation power at a resonant absorption frequency. A possible technical application of these systems is indicated. This approach to the problem of controlling and monitoring the state of the atmosphere can describe the propagation dynamics of contamination in real time, which is extremely important for ensuring safety in regions liable to chemical contamination. After suitable development, the proposed method may provide the basis for remote monitoring by radar techniques and in principle, may also be used to study various types of nonreflecting objects possessing the property of resonant absorption. Pis’ma Zh. Tekh. Fiz. 23, 1–5 (December 26, 1997)     

A pulse-type evaporator for ultrafast deposition of thin films in ultrahigh vacuum

The design of a simple pulse-type evaporator ensuring a high rate (up to ～10⁴ nm/s) of deposition of thin films (0.01–100 nm thick) onto a solid surface in ultrahigh vacuum is described. The evaporation pulse is created by discharge of a capacitor bank via a fast-response evaporator produced from a tungsten foil. Results illustrating the efficiency of this device are presented.     

Shock wave data interpretation in the TEFIS database

Statistical processing methods for shock wave experimental data are developed to be applied in the software complex TEFIS on thermophysical calculations of thermophysical properties of substances. Methods of increasing the precision of the wide-range shock adiabates calculation are developed based on them and the original calculation models for Hugoniot adiabates.     

Increase in the density of β-FeSi2 nanoclusters on a Si(111) surface by means of Si(111) √3 × √3R30°-B reconstruction

The formation of iron disilicide (β-FeSi₂) nanoclusters as a result of solid-state epitaxy at T = 500–700°C and an iron coverage of 0.05–0.5 monolayer on a boron-modified Si(111)√3 × √3 R30° surface has been studied by scanning tunneling microscopy. It is established that the number density of β-FeSi₂ nanoclusters on the Si(111) √3 × √3 R30°-B surface significantly exceeds the density of silicide clusters formed on the atomically clean Si(111) surface with a 7 × 7 reconstruction for the analogous iron coverages and annealing temperatures. At the same time, the density of point defects and clusters possessing metallic conductivity on the Si(111) √3 × √3 R30°-B surface is several orders of magnitude lower than on the Si(111)7 × 7 surface treated under identical conditions.     

Resource potential for wind-hydrogen power in Ukraine

The paper provides an assessment of the current wind energy potential in Ukraine, and discusses developmental prospects for wind-hydrogen power generation in the country. Hydrogen utilization is a highly promising option for Ukraine's energy system, environment, and business. In Ukraine, an optimal way towards clean zero-carbon energy production is through the development of the wind-hydrogen sector. In order to make it possible, the energy potential of industrial hydrogen production and use has to be studied thoroughly.Ukraine possesses huge resources for wind energy supply. At the beginning of 2020, the total installed capacity of Ukrainian wind farms was 1.17 GW. Wind power generation in Ukraine has significant advantages in comparison to the use of traditional sources such as thermal and nuclear energy.In this work, an assessment of the wind resource potential in Ukraine is made via the geographical approach suggested by the authors, and according to the «Methodical guidelines for the assessment of average annual power generation by a wind turbine based on the long-term wind speed observation data». The paper analyses the long-term dynamics of average annual wind speed at 40 Ukrainian weather stations that provide valid data. The parameter for the vertical wind profile model is calculated based on the data reanalysis for 10 m and 50 m altitudes. The capacity factor (CF) for modern wind turbine generators is determined. The CF spatial distribution for an average 3 MW wind turbine and the power generation potential for the wind power plants across the territory of Ukraine are mapped.Based on the wind energy potential assessment, the equivalent possible production of water electrolysis-derived green hydrogen is estimated. The potential average annual production of green hydrogen across the territory of Ukraine is mapped.It is concluded that Ukraine can potentially establish wind power plants with a total capacity of 688 GW on its territory. The average annual electricity production of this system is supposed to reach up to 2174 bln kWh. Thus, it can provide an average annual production of 483 billion Nm³ (43 million tons) of green hydrogen by electrolysis. The social efficiency of investments in wind-hydrogen electricity is presented.     

Inhibition of Neuronal Necroptosis Mediated by RIPK1 Provides Neuroprotective Effects on Hypoxia and Ischemia In Vitro and In Vivo

Ischemic brain injury is a widespread pathological condition, the main components of which are a deficiency of oxygen and energy substrates. In recent years, a number of new forms of cell death, including necroptosis, have been described. In necroptosis, a cascade of interactions between the kinases RIPK1 and RIPK3 and the MLKL protein leads to the formation of a specialized death complex called the necrosome, which triggers MLKL-mediated destruction of the cell membrane and necroptotic cell death. Necroptosis probably plays an important role in the development of ischemia/reperfusion injury and can be considered as a potential target for finding methods to correct the disruption of neural networks in ischemic damage. In the present study, we demonstrated that blockade of RIPK1 kinase by Necrostatin-1 preserved the viability of cells in primary hippocampal cultures in an in vitro model of glucose deprivation. The effect of RIPK1 blockade on the bioelectrical and metabolic calcium activity of neuron-glial networks in vitro using calcium imaging and multi-electrode arrays was assessed for the first time. RIPK1 blockade was shown to partially preserve both calcium and bioelectric activity of neuron-glial networks under ischemic factors. However, it should be noted that RIPK1 blockade does not preserve the network parameters of the collective calcium dynamics of neuron-glial networks, despite the maintenance of network bioelectrical activity (the number of bursts and the number of spikes in the bursts). To confirm the data obtained in vitro, we studied the effect of RIPK1 blockade on the resistance of small laboratory animals to in vivo modeling of hypoxia and cerebral ischemia. The use of Necrostatin-1 increases the survival rate of C57BL mice in modeling both acute hypobaric hypoxia and ischemic brain damage.     

A developmental approach AIDS motor learning

Bernstein (1967) suggested that people attempting to learn to perform a difficult motor task try to ameliorate the degrees-of-freedom problem through the use of a developmental progression. Early in training, people maintain a subset of their control parameters (e.g., joint positions) at constant settings and attempt to learn to perform the task by varying the values of the remaining parameters. With practice, people refine and improve this early-learned control strategy by also varying those parameters that were initially held constant. We evaluated Bernstein's proposed developmental progression using six neural network systems and found that a network whose training included developmental progressions of both its trajectory and its feedback gains outperformed all other systems. These progressions, however, yielded performance benefits only on motor tasks that were relatively difficult to learn. We conclude that development can indeed aid motor learning.