The materials of The International Scientific – Practical Conference is presented below.
The Conference reflects the modern state of innovation in education, science, industry and social-economic sphere, from the standpoint of introducing new information technologies.
It is interesting for a wide range of researchers, teachers, graduate students and professionals in the field of innovation and information technologies.
The article presents the possibility of obtaining polymer composite materials based on thermoplastic polyimide and tungsten oxide (WO3) modified with a hydrophobic silicone fluid. Data on surface microscopy, Vickers microhardness, density, and thermal stability of composites with different tungsten oxide contents are presented. As a result of modifying tungsten oxide, its surface becomes hydrophobic, and the contact angle increases from 31° to 101°. The microstructure of the surface of composites has a fine-grained structure without microcracks and chips. The lowest density material has no filler. With increasing filler content, the density increases. When the content of the filler is 80 wt %, the density is 4.35 g/cm3. The optimum content of tungsten oxide filler is 60 wt % as measured by the surface microhardness. The work shows that the introduction of the proposed filler significantly increases the heat resistance of polyimide. Pure polyimide is stable up to 425°С, and at a temperature of 680°С, its full thermal decomposition takes place. With increasing content of modified tungsten oxide in the composite, the rate of mass loss decreases. In the composite containing 60 wt % filler at 680°C, the mass loss is 38%.
Hybrid membranes were prepared by incorporating silica with propyl-imidazoline groups in polybenzimidazoles (phthalide-containing PBI or PBI based on 2,6- or 2,5-pyridinedicarboxylic acids). The influence effects of the silica precursor hydrolysis conditions on the conductivity of the hybrid membranes are studied. Ionic conductivity, water uptake, phosphoric acid doping, and gas permeability of the obtained materials were found to depend on the preparation method and the silica loading. The materials with 10 wt% of functionalized silica present the highest conductivity. A decrease of hydrogen permeability is observed for low silica loadings.
The structure–phase changes that are caused in the surface layers of ferritic–martensitic Eurofer 97 and 10Cr9WV steel samples by the action of pulsed powerful fluxes of deuterium plasma and deuterium ions, which are generated in a plasma focus (PF) setup, are studied. Before tests, the steels were subjected to standard heat treatment (normalizing, tempering), and the 10Cr9WV steel samples were additionally annealed at 600°C for 600 h to determine the stability of the structure and properties at the temperatures that are close to the operating temperatures. During irradiation, the power densities of plasma (qpl = 107–1010 W/cm2) and ion (qi = 109–1012 W/cm2) fluxes and the number of plasma beam pulses (5–12 at a pulse duration of ~100 ns) are varied. The irradiation of the Eurofer 97 steel at qpl = 108–1010 W/cm2 in the PF setup is shown to cause melting and ultrafast solidification of the surface layer with the subsequent formation of a fine cellular structure with a cell size of 100–150 nm in it. The surface film formed on the 10Cr9WV steel samples during preliminary long-term annealing is found to begin to fail at qpl = 108 W/cm2; this film is fully removed at qpl = 1010 W/cm2. This process is accompanied by the segregation of particles 1–3 μm in size, which are enriched in manganese, chromium, and oxygen. After the surface film is removed, irradiation promotes the removal of manganese from the surface layers, and manganese is also removed from the Eurofer 97 steel, which has no surface film in the initial state. The plasma beam treatment of the Eurofer 97 steel in the PF working chamber at qpl = 108 W/cm2 is found to cause the formation of retained austenite in its structure, and the content of retained austenite in the 10Cr9WV steel subjected to similar treatment is lower than in the Eurofer 97 steel by a factor of 20 because of the presence of a film on its surface. The irradiation of the 10Cr9WV steel at a higher power density (qpl = 1010 W/cm2), when the surface film is removed, equalizes the contents of retained austenite in the steels under study.
We show that the terahertz (THz) photoconductivity in the topological phase of Hg1–xCdxTe-based structures exhibits the apparent PT- (parity-time) symmetry whereas the P-symmetry and the T-symmetry, separately, are not conserved. Moreover, it is demonstrated that the P- and T-symmetry breaking may not be related to any type of the sample anisotropy. This result contradicts the apparent symmetry arguments and means that there exists an external factor that interacts with the sample electronic system and breaks the symmetry. We show that deviations from the ideal experimental geometry may not be such a factor.
Magnetic nanocomposites involving tetraborate ion (TB)-intercalated Mg–Al-layered double hydroxide (LDH) shell supported on magnesium ferrite core particles are synthesized, characterized, and compared with their non-magnetic analogues. The compositions of the obtained nanocomposites were determined and structural investigations were made by powder X-ray diffraction and Fourier transform infrared spectroscopy. Particle characteristics were examined by size distribution, specific surface area measurements, scanning electron microscopy and transmission electron microscopy. Room-temperature magnetic measurements were performed with a vibrating sample magnetometer. The dynamics and structure of the interlayer water molecules and borate ions were studied by molecular dynamics simulations. Analytical and modeling studies verified that the TB ions were arranged between the LDH layers in oblique positions. The products were found to carry ca. 6% boron (10**17 B atom/μg nanocomposite). The magnetic nanocomposite showed superparamagnetic properties and can potentially find applications in biomedical fields for the site-specific delivery of bio-potent boron agents.
Due to their high durability and immobilization properties, cementitious materials have found a considerable application in the design and construction of radioactive waste repositories in the last decades. During cement paste production, organic additives are introduced to modify various properties of cement. The presence of such organic complexants may negatively affect the immobilizing properties of cement with respect to radionuclides. For better understanding and prediction of the effects of interactions between organic molecules and cementitious materials with radionuclides, we have developed several representative models consisting of three principal components: (i) calcium silicate hydrate (C-S-H) phase - the main binding phase of cement; (ii) gluconate, a simple well-described molecule, as a representative of organic additives; (iii) U(VI), as one of the most studied radionuclides of the actinide series. The C-S-H phase with low Ca/Si ratio (~0.83) typical for â€œlow-pHâ€ and degraded cement pastes has been selected for this modelling study. Structural, and energetic aspects of the sorption processes of uranyl, gluconate, and their mutual correlations on the surface of cement were quantitatively modeled by classical molecular dynamics (MD) and potential of mean force (PMF) calculations. The ternary surface complex formation between uranyl hydroxides and Ca2+ cations at the C-S-H aqueous interfaces is shown to have an important role in the overall sorption process. In the presence of gluconate, U(VI) sorption on C-S-H is facilitated by weakening the Ca2+ binding with the surface. Additionally, Na+ is proven to be an important competitor for certain surface sorption sites and can potentially affect the equilibrium properties of the interface.
A Vikhr plasma-beam device of the Dense Plasma Focus (DPF) type with an energy of ~5 kJ has been recently put into operation at the Baikov Institute of Metallurgy and Material Science. The device, the design of its components, and its parameters are described. The physical processes that occur in the DPF working chamber during generation of beams of fast electrons, ions, cumulative jets of a hot plasma, hard X rays, and neutrons (if deuterium is used as a working gas) are considered. Experiments have been conducted with the aim of testing energy-saving DPF circuits using a new power supply circuit of the DPF chamber, which contains a crowbar gap and an electronic delay circuit. The device is used for testing, diagnosing, and modifying the radiation-thermal resistance of various materials intended for use in the thermonuclear power engineering and aerospace engineering. The first experiments with this device in radiation testing of materials and aerospace materials science are described.
The article examines the recent ‘schism’ in Eastern Orthodoxy to show how religion and politics are strongly intertwined in disputes over territory and sovereignty. It argues that two logics are at play in this conflict: one grounded in the theological‐political concept of ‘canonical territory’, the other in the notion of ‘communion’ at the basis of the Christian fellowship. The first is deployed in claims for national sovereignty as well as imperial domination, while the latter can make or break communities of faith. Drawing a parallel between the post‐socialist revival of religion in Ukraine and the current mobilization on the ground, it shows how these contradictory logics shape the fate of people, churches and states.
We report a study of epitaxial superconductive NbN films on vicinal to the X-cut of single crystal LiNbO3 substrates grown using reactive magnetron sputtering of Nb target in Ar -N2 atmosphere. It is found that the NbN films reveal sharp superconductive transition at TC= 15.2 K and anisotropy of critical current. Critical current measured along the Z direction exceeds JC along the Y direction regardless of the orientation of step edges of the vicinal surfaces. The anisotropy effect is attributed to NbN film uniaxial stress due to the lattice mismatch of NbN (0 0 1) layer along the Z direction of LiNbO3.