Formation of oxide layers on aluminum, niobium, and tantalum in molten alkali metal carbonates

The electrochemical synthesis of niobium, tantalum, and aluminum oxide nanolayers is studied in the melt of lithium, sodium, and potassium carbonates with various additives to a salt phase in an oxidizing atmosphere at a temperature of 773 and 873 K. A scheme is proposed for high-temperature anion local activation of the process. © 2013 Pleiades Publishing, Ltd

Features of micro- and ultrastructure of low-fat butter and its low-fat analogues

The aim of the research was to study the features of the structure of low-fat butter and butter pastes, which, in terms of composition and properties, more fully meet the requirements of a healthy diet than high-fat types of butter. The objects of research were: butter with fat content of 72.5%; butter with fat content of 55% made with the addition of skimmed milk powder; butter of the same fat content with the addition of stabilizers based on guar and xanthan gums and emulsifiers based on monoand diglycerides of fatty acids; butter pastes with fat content of 45% with similar additives used to increase the stability of the process of butter formation and improve the texture. The microstructure was studied using an MBI-6 microscope, and the ultramicrostructure was studied using a Phillips electron microscope. In the first case, the sample was prepared by crushing the sample, in the second one — by the method of ultrafast freeze-fracture and etching. Researches have shown that the use of the introduced ingredients improves the homogeneity of the structure of the studied products. Due to the ability of milk proteins and stabilizers to retain moisture, it is more evenly distributed and well retained in the fat matrix of the product, formed from crystalline and liquid fat in the form of a continuous phase, which is confirmed by a sufficient penetration depth of the fat-soluble dye. Plasma droplets in butter with fat content of 72.5% and 55% are more isolated than in butter pastes, as indicated by the greater penetration depth of the water-soluble dye. The average diameter of isolated moisture droplets in low-fat products was 3.3–5.4 μm, and the average diameter of the fat globules that form the basis of the crystalline framework was 5.4–7.4 μm, depending on the composition of the product. For butter with fat content of 72.5%, the values of these indicators were 2.8 and 4.0 μm. The results of the study indicate the presence of differences in the sizes of structural elements, but at the same time confirm the uniformity of the structure of low-fat products, allowing them to be attributed to dispersions «water-in-oil»

Corrosion-electrochemical behavior of nickel in an alkali metal carbonate melt under a chlorine-containing atmosphere

The corrosion-electrochemical behavior of a nickel electrode is studied in the melt of lithium, sodium, and potassium (40: 30: 30 mol %) carbonates in the temperature range 500-600°C under an oxidizing atmosphere CO2 + 0.5O2 (2: 1), which is partly replaced by gaseous chlorine (30, 50, 70%) in some experiments. In other experiments, up to 5 wt % chloride of sodium peroxide is introduced in a salt melt. A change in the gas-phase composition is shown to affect the mechanism of nickel corrosion. © 2013 Pleiades Publishing, Ltd

Developing the pedagogical culture of parents by means of social partnership with a supplementary education institution

© 2016 Nikitina.The urgency of the research is due to the current requirements to develop the pedagogical culture of parents, which can help them to be successful parents, to effectively interact with their children avoiding family upbringing mistakes. In this respect, the article aims to identify the conditions for development of the pedagogical culture of parents by means of social partnership with a supplementary education institution and to work out the program of parent education. The leading approaches to this problem are axiological, synergic, systematic, and existentialistic ones allowing to find a comprehensive solution to the problem of improving family education. The article describes the implemented program of development of the pedagogical culture of parents by means of social partnership with a supplementary education institution; it also provides empirical data on the results of the program implementation. The article describes the content of the program of development of the pedagogical culture of parents. In this regard, the article can be of use to education practitioners who have to interact with parents in their professional activity

A Porous Tungsten Substrate for Catalytic Reduction of Hydrogen by Dealloying of a Tungsten–Rhenium Alloy in an Aqueous Solution of Hydrochloric Acid

Selective dissolution of a tungsten (85 wt.%)–rhenium (15 wt.%) alloy with rhenium in hydrochloric acid at the temperature of 298 K and anodic polarization modes was carried out to develop a porous catalytic substrate and to recycle rare metals. The parameters of the effective selective anodic dissolution of the tungsten–rhenium alloy, including the differences in applied potentials and electrolyte composition, were found. It was established that samples of the tungsten– rhenium alloy possess the smallest average pore size after being exposed for 6000 s. The obtained porous tungsten samples were characterized by X-ray diffraction and scanning electron spectroscopy. A thermodynamic description of the processes occurring during the anodic selective dissolution of a binary alloy was proposed. In the course of the work, the selectivity coefficient was determined using an X-ray fluorescence wave-dispersion spectrometer XRF-1800. The existence of a bimodal structure on the tungsten surface after dealloying was proved. © 2022 by the authors. Licensee MDPI, Basel, Switzerland

Automated system for diagnosing craniocerebral injury

A Russian national computing and communication system designed to assist non-specialized physicians in the diagnosis and treatment of craniocerebral injury is described

Structure-Sensitive Mechanism of Nanographene Failure

The response of a nanographene sheet to external stresses is considered in terms of a mechanochemical reaction. The quantum chemical realization of the approach is based on a coordinate-of-reaction concept for the purpose of introducing a mechanochemical internal coordinate (MIC) that specifies a deformational mode. The related force of response is calculated as the energy gradient along the MIC, while the atomic configuration is optimized over all of the other coordinates under the MIC constant-pitch elongation. The approach is applied to the benzene molecule and (5, 5) nanographene. A drastic anisotropy in the microscopic behavior of both objects under elongation along a MIC has been observed when the MIC is oriented either along or normally to the C-C bonds chain. Both the anisotropy and high stiffness of the nanographene originate at the response of the benzenoid unit to stress.Comment: 19 pages, 7 figures 1 tabl

SYNTHESIS OF AN ACTIVE SHIELDING SYSTEM OF THE MAGNETIC FIELD OF POWER LINES BASED ON MULTIOBJECTIVE OPTIMIZATION

Purpose. The synthesis of the active shielding systems by technogenic magnetic field generated by the different types of high voltage power lines in a given region of space using various cables of controlled magnetic field sources. Methodology. The initial parameters for the synthesis of active shielding system parameters are the location of the high voltage power lines with respect to the protected transmission line space, geometry and number of cables, operating currents, as well as the size of the protected space and normative value magnetic field induction, which should be achieved as a result of shielding. The objective of the synthesis of the active shielding system is to determine their number, configuration, spatial arrangement, wiring diagrams and compensation cables currents, setting algorithm of the control systems as well as the resulting value of the induction magnetic field at the points of the protected space. Synthesis of active shielding system is reduced to the problem of multiobjective nonlinear programming with constraints in which calculation of the objective functions and constraints are carried out on the basis of Biot – Savart – Laplace law. The problem is solved by a stochastic multi-agent optimization of multiswarm of particles which can significantly reduce the time to solve it. Results. Active screening system synthesis results for the various types of transmission lines and with different amounts of controlled cables is given. The possibility of a significant reduction in the level of induction of the magnetic field source within a given region of space. Originality. For the first time carried out the synthesis of the active shielding systems, by magnetic field generated by the different types of high voltage power lines within a given region of space controlled by a magnetic field sources with different amounts of controlled cables. Practical value, Practical recommendations on reasonable choice of the number and spatial arrangement of compensating cables of active shielding systems for different types of high voltage power lines in order to ensure the effectiveness of a given shielding of the magnetic field high voltage power lines

Evolution of the vertebrate claudin gene family: insights from a basal vertebrate, the sea lamprey

Claudins are major constituents of tight junctions, contributing both to their intercellular sealing and selective permeability properties. While claudins and claudin-like molecules are present in some invertebrates, the association of claudins with tight junctions has been conclusively documented only in vertebrates. Here we report the sequencing, phylogenetic analysis and comprehensive spatiotemporal expression analysis of the entire claudin gene family in the basal extant vertebrate, the sea lamprey. Our results demonstrate that clear orthologues to about half of all mammalian claudins are present in the lamprey, suggesting that at least one round of whole genome duplication contributed to the diversification of this gene family. Expression analysis revealed that claudins are expressed in discrete and specific domains, many of which represent vertebrate-specific innovations, such as in cranial ectodermal placodes and the neural crest; whereas others represent structures characteristic of chordates, e.g. pronephros, notochord, somites, endostyle and pharyngeal arches. By comparing the embryonic expression of claudins in the lamprey to that of other vertebrates, we found that ancestral expression patterns were often preserved in higher vertebrates. Morpholino mediated loss of Cldn3b demonstrated a functional role for this protein in placode and pharyngeal arch morphogenesis. Taken together, our data provide novel insights into the origins and evolution of the claudin gene family and the significance of claudin proteins in the evolution of vertebrates