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The effect of the saturation of a current transformer (CT) on the operation of the starting elements of high-speed backup relay protection is examined. A method for selective detection of an external fault evolving into an internal fault with CT saturation is proposed. The method is applicable to both main and backup protections. [ABSTRACT FROM AUTHOR]

A prototype of a mobile device for measuring skin resistance on a patient's finger in the range of 0.75–5 MΩ was developed and assembled. Application of a patented method for the diagnosis of rejection using normalized skin resistance values obtained during systematic examination identified signs of kidney rejection in a series of patients, with confirmation by subsequent biopsy of grafts. [ABSTRACT FROM AUTHOR]

Eigenmodes in equilateral and isosceles triangular trimers of infinite cylinders have been studied using the theory of multiwave scattering. Equations have been derived for the eigenfrequencies of the exceptional points where eigenfrequencies and eigenvectors are degenerate. The symmetry of the isosceles triangular trimer determines the separation of modes antisymmetric in the base direction. In the case of the equilateral triangular trimer, modes are separated into symmetric and double degenerate rotational modes. It has been found that damping symmetric modes in the trimer have a higher Q-factor compared to a dimer, which is of significant importance for applications of effects based on exceptional points. The behavior of complex eigenfrequencies in the isosceles triangular trimer has also been studied depending on the ratio of the lengths of its base and leg. At the point corresponding to the equilateral triangular trimer, the Q-factors of symmetric and antisymmetric modes have the local maximum and minimum, respectively. [ABSTRACT FROM AUTHOR]

The problem of taking into account the influence of air on the properties of distilled water is considered, namely the lack of a single generally accepted method for calculating such an influence. The sensitivity of the structure of water to the influence of external factors is described and the possibility of recording and studying such factors based on changes in the temperature coefficient of electrical conductivity of water is shown. The dependences of the temperature coefficient of electrical conductivity of distilled water on the rate of change in water temperature, the degree of filling of conductometric cells, as well as on the intensity of carbon dioxide exchange between water and air across their interface have been studied. It is noted that currently these exchange processes are studied insufficiently. A hardware-software measuring complex has been developed and manufactured to study the temperature coefficient of electrical conductivity of water in the temperature range of 20–55 °C. The temperature coefficient of electrical conductivity of water was measured in sealed conductometric cells at different degrees of filling with distilled water and various water heating and cooling rates. The degree of cell filling varied from 10 to 100%, and the water temperature variation rate—from 0.04 to 2.00 °C/min. With a constant heating and cooling time of 15 min in all experiments, the rate was varied by changing the temperature of the heating element. The integral temperature coefficient of electrical conductivity is calculated based on the initial and final values of electrical conductivity and water temperature in each measurement cycle. The dependences of the temperature coefficient of electrical conductivity on the water temperature variation rate at several constant values of the degree of cell filling were obtained. It was shown that at a constant water-to-air volume ratio in the cell and increased water heating rate, the temperature coefficient of electrical conductivity of water decreases by 19–22%. It has been established that at a constant water heating rate, the temperature coefficient of electrical conductivity of water decreases by 40–42% as the cellular water volume drops. The obtained results can be used to quantify the coefficient of carbonic acid dissociation, mobility of hydrogen ions, as well as intensity of the gas exchange process at various external conditions affecting water. Refinement of data on the electrical conductivity of water and processes occurring at the water/air interface is necessary for the development of models of atmospheric phenomena and climate changes, as well as for the creation of sensors capable of detecting weak changes in the environmental parameters for the purposes of environmental monitoring and medical diagnostics. [ABSTRACT FROM AUTHOR]

The article discusses the characteristics of the joint operation of current transformers (CTs) of various accuracy classes with advanced algorithms for the differential protection of a microprocessor-based transformers. The issues of modern differential protection of transformer algorithms are presented, as well as means to address them, both using CTs with air gaps and improving their algorithms. [ABSTRACT FROM AUTHOR]

In this work, feasibility tests of new two-stage approach of deposition of thick high-entropy alloy coatings were performed. At the first stage of this approach, metal composite coating is formed by detonation spraying of low-entropy metal powder blends. At the second stage, the composite precursor coating is heat treated in order to promote the synthesis of high-entropy phases. The tests were carried out using three different powder mixtures of Fe, Ni, Cu, Co, and Al powders. Experimental results showed that the detonation spraying allows formation of uniform metal composite coating. The microstructure analysis and microhardness measurements of the coating before and after heat treatments confirmed that the heat treatment enables element diffusion in the coating followed by formation of CoFeNi, CoCuFe0.8Ni, and Al0.05CoCu0.3FeNi alloys with uniform fcc structure after recrystallization. At the same time, the final composition of the coatings differed from the targeted ones due to different deposition efficiencies of the particles during detonation spraying process. [ABSTRACT FROM AUTHOR]

The results of the study of the effect of thermal annealing and diffusion on the structure of a porous silicon film formed by metal-assisted etching on a single-crystal silicon substrate are presented. The porous silicon film surface is studied by scanning electron microscopy and Raman scattering spectroscopy. It is shown that thermal treatment modes affect the morphology of porous silicon films on micro- and nanometer scales. [ABSTRACT FROM AUTHOR]

In order to study the shot peening that occurs during the application of powder coatings, experiments are carried out on glass shot peening of steel test strips using a CCDS2000 detonation device. Experimental dependences of the shot peening depth and the residual stresses in a hardened layer on treatment parameters (particle size, density, and velocity, as well as the strength of the test strip material) are obtained. Engineering equations are proposed for calculating the values of and . [ABSTRACT FROM AUTHOR]

The article describes the studies on the geomechanical behavior of the large pitwall rock mass using the seismic method. The on-site measurements of elastic wave velocities in rock mass enabled determining the elastic characteristics of rocks, which allowed an inference on the rock mass stability. It is shown that the seismic method provides sufficiently reliable data on the time history of the geomechanical behavior of the large-area pitwall rock mass, and enables the geomechanics and stability control. The long-term experience of using the seismic method to ensure pitwall rock mass stability is presented as a case-study of Zhelezny Open Pit Mine, Kovdor Mining and Processing Plant. The proposed approach is applicable at deep open pit mines. [ABSTRACT FROM AUTHOR]

In this paper, the problem of scattering of a plane harmonic electromagnetic wave on a double wire array is solved accurately. The array consists of two identical infinite wire gratings arranged in a free space. Each of the grids consists of parallel thin, infinitely long metal cylinders of circular cross section. The study considers the case when the electric vector of the incident wave is parallel to the wires. The expression for the total reflection coefficient is obtained in the dipole approximation for the case of s -polarization. Analysis of the spectrum of the total reflection coefficient in the subwavelength part of the microwave frequency range was carried out. The paper proposes a new approach for determining the effective relative permittivity and permeability, as well as the effective refractive index of the grating. The approach does not depend on the number of grating layers and allows to taking into account near-field couplings in homogenizing the grating. This approach also allowed us to describe the behavior of the reflectivity and obtain expressions for the effective parameters of the grating at and near the resonant frequency. The validation of all the approximations obtained in the study was carried out using a finite-difference time-domain electromagnetic simulator. [ABSTRACT FROM AUTHOR]

We consider an optical dimer consisting of two particles having a resonance in the optical range, which might be used as a building block for photonic structures such as metamaterials. We find its eigenmodes that can be excited independently for symmetric and asymmetric dimers, and correlate them to the geometry of illumination that might be used to excite these modes. [ABSTRACT FROM AUTHOR]

The results of an experimental study of the surface morphology of zinc-oxide films and the electrical properties of structures based on a single-crystal Si/microcrystalline ZnO heterojunction are presented. An analysis of the structure of the zinc-oxide films grown in argon and oxygen atmospheres is carried out, and the size distribution of nanofibers grown on its surface is obtained. The capacitance–voltage characteristics of In/ZnO/n-Si/Al and Au/ZnO/n-Si/Al heterostructures are simulated. On the basis of calculations and comparison of the experimental and simulated dependences, the concentration of free charge carriers in the sample and the position of the Fermi level are determined, the presence of a fixed charge in the system is revealed, and the density of surface states is found based on the ratio of the voltage applied to the system and the surface potential at the interface between layers. The value of the built-in surface charge is calculated. The relationship between the material of the upper contacts and the capacitance–voltage and current–voltage characteristics of the system is studied. The resistance of the formed zinc-oxide films is calculated. The prevailing charge-transfer mechanisms are discussed. An empirical dependence of the surface potential of silicon on the voltage applied to the structure is revealed. The effect of technological modes for obtaining zinc-oxide films synthesized by spray pyrolysis on the surface structure, effective capacitance of the structure, density of electronic states, and processes of charge-carrier transfer in samples under the action of an electric field is analyzed. [ABSTRACT FROM AUTHOR]

Figurative depictions in art first occur ca. 50,000 years ago in Europe, Africa, and Southeast Asia. Considered by most as an advanced form of symbolic behavior, they are restricted to our species. Here, we report a piece of ornament interpreted as a phallus-like representation. It was found in a 42,000 ca.-year-old Upper Paleolithic archaeological layer at the open-air archaeological site of Tolbor-21, in Mongolia. Mineralogical, microscopic, and rugosimetric analyses points toward the allochthonous origin of the pendant and a complex functional history. Three-dimensional phallic pendants are unknown in the Paleolithic record, and this discovery predates the earliest known sexed anthropomorphic representation. It attests that hunter-gatherer communities used sex anatomical attributes as symbols at a very early stage of their dispersal in the region. The pendant was produced during a period that overlaps with age estimates for early introgression events between Homo sapiens and Denisovans, and in a region where such encounters are plausible. [ABSTRACT FROM AUTHOR]

The paper presents new data on the formation conditions of basalts from Menshiy Brat postcaldera volcano in the Medvezhia caldera, Iturup Island. The liquidus mineral assemblage consists of olivine (Fo 85.3–90.1 mol %) and chromium spinel (Cr# = 0.46–0.6), which crystallized at 1090–1170°C and oxygen fugacity at NNO + 0.6 (σ = 0.2) to NNO + 0.2 (σ = 0.14) in the course of the eruption. Data on melt inclusions in the liquidus olivine demonstrate that its parental melts were low-Al2O3 and low-K2O, with up to 15.5 wt % MgO, and with an average H2O content of 5.5 wt %. The newly obtained data on volatile contents in the olivine-hosted melt inclusions suggest that the mafic melts were derived by the partial melting of a peridotitic-rich source with a small admixture of an olivine-free component at 1225°C, under active influence of the slab-derived fluids. These fluids were separated from the subducting slab at 670–705°C and depths of 95–105 km beneath Iturup Island. Our results enhance our understanding of the evolution of basic magmas that serve as a heat and volatile sources during the formation of large calderas. [ABSTRACT FROM AUTHOR]

We consider an approach to engineer an optical dimer of particles operating in the spectral region near the dipolar resonance that exhibits parity–time symmetry-like features. Both particles are assumed to be made of a gain medium with the same refractive index and extinction coefficient. We suggest introducing a gain–loss contrast by altering the radiative loss of the particles through changing their shape. To demonstrate our approach, we consider a dimer of infinite filled and hollow cylinders. We demonstrate that a larger hollow diameter leads to a stronger radiative decay. Then we find the parameters of a dimer that has an exceptional point at a real frequency and exhibits two real eigenfrequencies when the gain–loss contrast is decreased. [ABSTRACT FROM AUTHOR]

Design methods in the reciprocal space allow one to obtain structures with desired properties. Quasicrystalline photonic structures, which ensure the selective scattering of an electromagnetic wave incident on the sample, have been designed. The maxima of the Fourier transform of the desired distribution of the permittivity in the reciprocal space are located along two arcs on the Ewald sphere, which corresponds to the scattering of the wave with the required wavelength and angle of incidence. The material distribution has been determined by the transition to the real space. A structure with a low dielectric contrast has been formed after the binarization of the refractive index. The theoretical analysis of the properties of the structure has confirmed the frequency–angular selectivity of scattering. The numerical calculations show the possibility of achieving the effective scattering and absorption of the electromagnetic energy up to 94% in a narrow frequency range and in a narrow interval of angles of incidence at a dielectric contrast of two materials of 1.07. [ABSTRACT FROM AUTHOR]

Contactless acoustic methods were used to determine electrical parameters—electrical conductivity, carrier mobility and their concentration—in single-layer graphene deposited on the surface of lithium niobate. [ABSTRACT FROM AUTHOR]

Abstract Protein post‐translational modifications (PTMs) represent important regulatory states that when combined have been hypothesized to act as molecular codes and to generate a functional diversity beyond genome and transcriptome. We systematically investigate the interplay of protein phosphorylation with other post‐transcriptional regulatory mechanisms in the genome‐reduced bacterium Mycoplasma pneumoniae. Systematic perturbations by deletion of its only two protein kinases and its unique protein phosphatase identified not only the protein‐specific effect on the phosphorylation network, but also a modulation of proteome abundance and lysine acetylation patterns, mostly in the absence of transcriptional changes. Reciprocally, deletion of the two putative N‐acetyltransferases affects protein phosphorylation, confirming cross‐talk between the two PTMs. The measured M. pneumoniae phosphoproteome and lysine acetylome revealed that both PTMs are very common, that (as in Eukaryotes) they often co‐occur within the same protein and that they are frequently observed at interaction interfaces and in multifunctional proteins. The results imply previously unreported hidden layers of post‐transcriptional regulation intertwining phosphorylation with lysine acetylation and other mechanisms that define the functional state of a cell.

Abstract Protein–metabolite networks are central to biological systems, but are incompletely understood. Here, we report a screen to catalog protein–lipid interactions in yeast. We used arrays of 56 metabolites to measure lipid‐binding fingerprints of 172 proteins, including 91 with predicted lipid‐binding domains. We identified 530 protein–lipid associations, the majority of which are novel. To show the data set's biological value, we studied further several novel interactions with sphingolipids, a class of conserved bioactive lipids with an elusive mode of action. Integration of live‐cell imaging suggests new cellular targets for these molecules, including several with pleckstrin homology (PH) domains. Validated interactions with Slm1, a regulator of actin polarization, show that PH domains can have unexpected lipid‐binding specificities and can act as coincidence sensors for both phosphatidylinositol phosphates and phosphorylated sphingolipids.

Chaotic analog circuits are commonly used to demonstrate the physical existence of chaotic systems and investigate the variety of possible applications. A notable disparity between the analog circuit and the computer model of a chaotic system is usually observed, caused by circuit element imperfectness and numerical errors in discrete simulation. In order to show that the major component of observable error originates from the circuit and to obtain its accurate white-box model, we propose a novel technique for reconstructing ordinary differential equations (ODEs) describing the circuit from data. To perform this task, a special system reconstruction algorithm based on iteratively reweighted least squares and a special synchronization-based technique for comparing model accuracy are developed. We investigate an example of a well-studied Rössler chaotic system. We implement the circuit using two types of operational amplifiers. Then, we reconstruct their ODEs from the recorded data. Finally, we compare original ODEs, SPICE models, and reconstructed equations showing that the reconstructed ODEs have approximately 100 times lower mean synchronization error than the original equations. The proposed identification technique can be applied to an arbitrary nonlinear circuit in order to obtain its accurate empirical model. [ABSTRACT FROM AUTHOR]

All-dielectric nanophotonics opens a venue for a variety of novel phenomena and scattering regimes driven by unique optical effects in semiconductor and dielectric nanoresonators. Their peculiar optical signatures enabled by simultaneous electric and magnetic responses in the visible range pave a way for a plenty of new applications in nano-optics, biology, sensing, etc. In this work, we investigate fabrication-friendly truncated cone resonators and achieve several important scattering regimes due to the inherent property of cones—broken symmetry along the main axis without involving complex geometries or structured beams. We show this symmetry breaking to deliver various kinds of Kerker effects (generalized and transverse Kerker effects), non-scattering hybrid anapole regime (simultaneous anapole conditions for all the multipoles in a particle leading to the nearly full scattering suppression) and, vice versa, superscattering regime. Being governed by the same straightforward geometrical paradigm, discussed effects could greatly simplify the manufacturing process of photonic devices with different functionalities. Moreover, the additional degrees of freedom driven by the conicity open new horizons to tailor light-matter interactions at the nanoscale. [ABSTRACT FROM AUTHOR]

Here, we report a fragmentary Castor fiber (Linnaeus, 1758) proximal left ulna from Tsagaan Agui Cave (Gobi Altai Mountains, southern Mongolia). This constitutes the first fossil evidence of this rodent from Mongolia. The Eurasian beaver is considered extinct in the Gobi Desert but fossilized remains recovered from cave deposits provide evidence that adequate habitat conditions for C. fiber existed in the Gobi Desert during some periods of the Pleistocene. Fossil C. fiber remains are relatively rare in neighboring regions including Siberia and the Russian Far East. Here, we also review the geographical distribution of fossil C. fiber in Central Asia, southern and eastern Siberia, and the Russian Far East. [ABSTRACT FROM AUTHOR]

A pulse gas-detonation device (PGDD) is applied to investigate the process of initiation and detonation in C2H2+ O2 acetylene–oxygen mixtures, including those with a low oxygen content near the upper detonation concentration limit, at initial atmospheric pressure. Cell sizes, detonation velocities, and pressures in detonation products are measured in a range of from zero to unity. The detonation product composition is calculated. Upper detonation limits in the PGDD barrels with diameters of 14, 26, 46, and 104 mm are determined. The volume of booster charges required to initiate detonation in the limiting modes are revealed. As for the hydrogen energy industry, the methane acetylene hydrogen + nanosized detonation carbon technological chain is considered, and the characteristics of the PGDD as a hydrogen generator are estimated. [ABSTRACT FROM AUTHOR]

A systematic study of detonation deposition of wear-resistant coatings made of composite powders based on chromium carbide used to harden parts operating at temperatures up to 870°C is carried out. An integrated analysis of the characteristics of coatings produced from powders of Russian and foreign manufacturers was carried out. A composite in the form of mechanical mixture and powders obtained by cladding and the Spray–Dry method are considered. Using a numerical code, the acceleration and heating of particles of the sprayed powder are calculated and the optimal spraying modes are determined. The hardness, porosity, wear resistance, and bond strength of the resulting coatings were considered. A comparative characterization of residual stresses has been carried out. The influence of the spraying distance in the range from 50 to 400 mm and of the inclination angle of the treated surface up to 60° has been studied. It is shown that in the case of dual-fuel mixture spraying, the density and wear resistance of coating increase and residual tensile stresses are completely eliminated. The adhesion of the resulting coatings exceeds 150 MPa, and the abrasive resistance of the best coating is characterized by a specific wear of about 3 mm3/1000 rpm according to the ASTM G65 standard, which is 5 times higher than the resistance of the alloys used for the manufacture of gas turbine parts. [ABSTRACT FROM AUTHOR]

A GGGGCC24+ hexanucleotide repeat expansion (HRE) in the C9ORF72 gene is the most common genetic cause of amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD), fatal neurodegenerative diseases with no cure or approved treatments that substantially slow disease progression or extend survival. Mechanistic underpinnings of neuronal death include C9ORF72 haploinsufficiency, sequestration of RNA-binding proteins in the nucleus, and production of dipeptide repeat proteins. Here, we used an adeno-associated viral vector system to deliver CRISPR/Cas9 gene-editing machineries to effectuate the removal of the HRE from the C9ORF72 genomic locus. We demonstrate successful excision of the HRE in primary cortical neurons and brains of three mouse models containing the expansion (500–600 repeats) as well as in patient-derived iPSC motor neurons and brain organoids (450 repeats). This resulted in a reduction of RNA foci, poly-dipeptides and haploinsufficiency, major hallmarks of C9-ALS/FTD, making this a promising therapeutic approach to these diseases. A hexanucleotide repeat expansion in C9ORF72 is the most common genetic cause of ALS and FTD. Here, the authors demonstrate CRISPR/Cas9 excision of the expansion results in a rescue of disease mechanisms in vivo and in vitro. [ABSTRACT FROM AUTHOR]

Abstract—Electromagnetic investigation of stress-strain state dynamics in the geological medium is based on the analysis of two groups of physical phenomena. The first group includes phenomena associated with the dynamics of electrical properties of rocks caused by a change in their fracturing, porosity, fluid content, structure and texture, temperature and pressure, etc. The second group covers the effects of generation of endogenous (geodynamic) sources of electromagnetic field under irreversible deformations of the geological medium. In this paper, we present the practical results of the studies of the Earth's natural electromagnetic field that have been carried out at the Research Station of the Russian Academy of Sciences in Bishkek over 40 years of operation of the Bishkek Geodynamical Test Site of the Research Station and aimed at gaining new insights into the present-day geodynamics of the Tien Shan lithosphere. The results of the experimental study of the first group of phenomena are based on the analysis of temporal changes in the magnetotelluric transfer functions. In this analysis it is assumed that the present-day geodynamic processes including catastrophic ones, e.g., earthquakes, trigger the crack formation processes which, in turn, changes the pore-fracture space of the rocks and causes fluid redistribution in them, thus resulting in the changes in the electrical conductivity of the geological medium. The practical results of the studies of the second group of phenomena are based on the notion that the geodynamic processes induced in the Tien Shan crust by irreversible deformations of rocks create sources of electromagnetic radiation leading to the variations in the endogenous electromagnetic field which can be observed on the ground. [ABSTRACT FROM AUTHOR]

A compact waveguide Tm:YAP laser with a pulse repetition rate of 8 GHz is developed. A controllable change in the intracavity loss provides continuous tuning of the central emission wavelength of the laser operating in the Q-switched mode-locking in the range from 1925 to 1950 nm, as well as makes it possible dual-wavelength lasing. The main approach of this study is the use of waveguide structures inside the Tm:YAP crystal and the saturable absorber based on graphene. This approach is universal for producing compact lasers with the gigahertz pulse repetition rate, operating in a wide spectral range. [ABSTRACT FROM AUTHOR]

A neural network method has been proposed to calculate the configurations and energies of the ground states of the Edwards–Anderson spin glass model with periodic boundary conditions. The macroscopic degeneracy of the ground states and violation of translational symmetry have been observed. Comparison with the results obtained by the exact and approximate computational methods confirms the reliability of the results. [ABSTRACT FROM AUTHOR]

In the present work, a medium-entropy alloy, FeCoNiCu, was selected as a model system to demonstrate the possibility of fabricating solid solution-type alloy coatings by detonation spraying. A mixture of Fe+Co+Ni+Cu powders was first treated in a high-energy planetary ball mill. The evolution of the microstructure of the FeCoNiCu alloy particles with the milling time was investigated. After 20 min of milling, the powder was nearly a single-phase solid solution of face-centered cubic structure. A bulk alloy was obtained by consolidating the ball-milled powders by spark plasma sintering. The coatings and sintered material were studied by x-ray diffraction and scanning electron microscopy/energy-dispersive spectroscopy/elemental mapping. No oxidation of the material occurred during detonation spraying. The coatings and sintered alloy obtained from the powder mixture milled for 20 min were nearly single-phase with a major phase of face-centered cubic structure. The residual porosity of the coatings and sintered alloy was as low as ~1%. The hardness values of the coatings and sintered alloy were found to be close to each other (~400 HV300). This work showed that a combination of high-energy milling and detonation spraying is a viable route for the formation of nearly single-phase medium-entropy FeCoNiCu alloy coatings. [ABSTRACT FROM AUTHOR]

We have received unique material on the development of the natural environment for the last 12 400 cal. yr. BP in the central part of Iturup Island. High-resolution paleoreconstructions have been based on the multi-proxy study of paleolake sediments found on the plateau (height 400–420 m) located northwest of the Baransky Volcano. For the first time, a record of paleogeographic events has been obtained for the Late Glacial and the Early Holocene. The age model is based on nine radiocarbon dates. Diatom analysis has made it possible to distinguish 11 stages of lake–swamp evolution. The paleolake reached its maximum depth at ~9890–7900 cal. yr. BP and became extinct at 1400 cal. yr. BP. The vegetation development stages and the landscape change factors have been restored. The Younger Dryas cooling recorded in Iturup was characterized by humidity changes. The role of forest vegetation rapidly increased at the Pleistocene–Holocene boundary of ~11 470 cal. yr. BP under warmer climatic conditions. Distribution of dwarf pine as an indicator of stable snow cover has been analyzed. Dark-coniferous forests existed in the mountainous part of the island since the Late Glacial and were the most widespread in the Early Holocene. The onset of birch forest expansion at 6200 cal. yr. BP was related to the intensification of volcanic activity and frequent ash falls. A number of identified cold events were enhanced by the weakening of the warm Soya Current. The intensive transfer of allochthonous pollen from the southern Kuril Islands and the Japanese Islands at 3540 cal. yr. BP is a sign of cyclogenesis intensification in the Kuril Islands. The Holocene climatic rhythms in the landscape development of the Iturup mountains, as well as the influence of warm and cold currents and other regional factors, have been analyzed. [ABSTRACT FROM AUTHOR]

Detonation spraying of wear-resistant Cr3C2-NiCr coatings was carried out using a two-fuel 0.61C2H2 + 0.26C3H8 + O2 explosive mixture. The coatings were formed from agglomerated powders containing 10, 20 and 25 wt.% of the nichrome binder. The deposition efficiency was measured. The microstructure, bonding strength, hardness and wear resistance of the coatings were studied as functions of the spraying distance and spraying angle. The coatings of the highest quality had a porosity of less than 0.5%. Irrespective of the binder content, the bonding strength of the coatings was equal to or greater than 150 MPa. In the ASTM G-65 abrasion test, the volume loss of Cr3C2-20NiCr coating was 3.1 mm3/1000 rev. In addition, the level of residual stress was evaluated using the Almen test. The coatings of the highest quality possessed compressive residual stresses. For applications under wear conditions and increased mechanical loads, a coating containing 20% of NiCr binder is recommended. The results of this study can be useful for selecting the modes of the coating deposition on components of complex shape. [ABSTRACT FROM AUTHOR]

A remarkable feature of chaotic systems is high sensitivity, which makes them applicable to the construction of sensing devices. Various sensors can be developed based on chaotic oscillators, e.g., metal detectors, salinometers, inductive sensors, and optical sensors. Our study investigates the properties of the metal detector based on Sprott Case N chaotic oscillator equipped with a single inductive coil. A key feature of this circuit is the ability to operate in two modes: chaotic and spiking chaotic oscillations. The last fact makes it possible to consider this circuit as an artificial sensitive neuron and apply processing methods suitable for neuron activity investigation, such as interspike interval histogram analysis. In a well-controllable experiment, we explicitly demonstrate that the developed metal detector has a continuous response depending on the distance to the target and the target material. We present several efficient modifications of data processing techniques to obtain measurement results from chaotic data series. Finally, we compare the developed chaotic sensor with the sensor based on the harmonic oscillator and show that the operating range of the chaotic sensor is at least 20% larger than that of the harmonic sensor. [ABSTRACT FROM AUTHOR]

Bromodomain and extraterminal domain (BET) proteins have emerged as therapeutic targets in multiple cancers, including the most common primary adult brain tumor glioblastoma (GBM). Although several BET inhibitors have entered clinical trials, few are brain penetrant. We have generated UM-002, a novel brain penetrant BET inhibitor that reduces GBM cell proliferation in vitro and in a human cerebral brain organoid model. Since UM-002 is more potent than other BET inhibitors, it could potentially be developed for GBM treatment. Furthermore, UM-002 treatment reduces the expression of cell-cycle related genes in vivo and reduces the expression of invasion related genes within the non-proliferative cells present in tumors as measured by single cell RNA-sequencing. These studies suggest that BET inhibition alters the transcriptional landscape of GBM tumors, which has implications for designing combination therapies. Importantly, they also provide an integrated dataset that combines in vitro and ex vivo studies with in vivo single-cell RNA-sequencing to characterize a novel BET inhibitor in GBM. [ABSTRACT FROM AUTHOR]

Structural changes in FTW60 and FTW8000 tantalum capacitor powders after sintering at different temperatures are investigated by X-ray diffraction and scanning electron microscopy. Sintering is carried out in accordance with the current technological process used in the production of oxide–semiconductor capacitors. The anodes obtained as a result of sintering are bulk-porous bodies in the form of a rectangular parallelepiped with a wire lead. On the free surface of the bulk-porous anodes obtained by sintering the FTW60 powder at temperatures of 1800°C and 1920°C, the formation of a wavy relief is observed. No such relief is observed after sintering the FTW800 powder at 1250°C. After analyzing the structural state and the morphology of the initial powders and the anodes obtained as a result of sintering, a phenomenological model of the formation of such a relief is proposed based on collective recrystallization near the free surface during high-temperature exposure. [ABSTRACT FROM AUTHOR]

The feasibility study of elaboration of metal composite coatings by detonation spray using the blends of iron, nickel, copper, cobalt, and aluminum powders was performed using different spray modes. The numerical simulation of particle parameters showed that the particles formed the coating in solid, semi-molten, or molten state depending on the spraying modes, particle material, and particle size. It was shown that successful formation of the coating containing all powder mixture components could be achieved in case of proper optimization of spraying parameters. Obtained Fe-Co-Ni, Fe-Co-Ni-Cu, and Fe-Co-Ni-Cu-Al coatings had the uniform lamellae structure. However, the composition of the coatings differed from the initial powder mixture composition due to different deposition efficiencies of the powders. It was also found the mutual influence of blend components on bonding. In particular, the deposition efficiency of iron particles was probably affected by copper. [ABSTRACT FROM AUTHOR]

Metal matrix composites containing nanoscale carbon (nanotubes, graphene, etc.) are of great interest from the viewpoint of developing materials with improved mechanical properties. In the present work, detonation spraying experiments were conducted to produce composite coatings containing in situ generated nanoscale carbon. The coatings were prepared by detonation spraying with the use of fuel-rich acetylene-oxygen mixtures. When C2H2 + kO2 mixtures with k < 1 detonate, together with gaseous detonation products, solid graphene-like carbon nanoparticles form in the detonation gun barrel. When spraying a powder, these particles enter the coating layer and affect its properties. The phase composition and mechanical properties of coatings obtained from Al, Cu, Ni and Ti powders in the mode of in situ carbon generation are reported. The microhardness of the carbon-containing composite coatings was higher than that of the pure metal coatings and bulk commercial metals. The cohesion of Al- and Cu-based coatings containing carbon and carbon-free coatings did not actually differ. However, the presence of carbon reduced the cohesion of the Ni-based coating by about 30% and, conversely, increased the cohesion of the Ti-based coating by 30%. This work opens a new avenue for research and applications in the area of coatings formed by detonation spraying. [ABSTRACT FROM AUTHOR]

Recent studies on the application of generative adversarial networks (GAN) for speech synthesis have shown improvements in the naturalness of synthesized speech, compared to the conventional approaches. In this article, we present a new framework of GAN to train an acoustic model for speech synthesis. The proposed GAN consists of a generator and a pair of agent discriminators, where the generator produces acoustic parameters taking into account linguistic parameters; and the pair of agent discriminators are introduced to improve the naturalness of the synthesized speech. We feed the agents with acoustic and linguistic parameters, thereby the agents do not only examine the acoustic distribution, but also the relationship between linguistic and acoustic parameters. Training and testing were conducted on the Kazakh speech corpus. According to the results of this research, the proposed framework of GAN improves the accuracy of the acoustic model for the Kazakh text-to-speech system. [ABSTRACT FROM AUTHOR]

The results of statistical processing of oscillograms of pressure pulsations in the flow path of turbines of a large reservoired hydroelectric power plant are presented. Patterns of pressure pulsations in high-head hydroelectric power plants with individual water conduits are determined. The parameters used to specify the disturbances in mathematical modeling are justified. [ABSTRACT FROM AUTHOR]

We describe the advantages and disadvantages of infrared and electrochemical gas analyzers of carbon dioxide (CO2). We study the possibility of application of conductometric sensors with distilled water for the purposes of monitoring of the CO2 content in air. We manufactured two identical measuring systems each of which contains two open-type conductometric cells, a matching device, and a personal computer. With the help of these complexes, we performed the experiments aimed at simultaneous measurements of the CO2 content in air at two sites (in a laboratory room and in a building located in the forest at a distance of 15 km from the first site) with knowingly different daily dynamics of variations of the CO2 level. We carried out special experiments aimed at the determination of the time lag of conductometric cells and evaluation of the conversion factor of the obtained levels of CO2 content into the standard measurement units. It is shown that the daily dynamics of variations of the electric conductivity of distilled water in the open cells agrees with the expected dynamics of changes in the CO2 content in the rooms used for measurements. The serviceability of the analyzed measuring complex is confirmed and the possibility of creation of a device based on this complex and intended for the long-term monitoring of the CO2 content in the air mixture of gases is demonstrated. The high selectivity of the proposed measuring complex to the presence of CO2 (as compared with the other atmospheric gases) is established. [ABSTRACT FROM AUTHOR]

Heterostructures of Bi2Se3 topological insulators were epitaxially grown on graphene by means of the physical vapor deposition at 500 °C. Micrometer-sized flakes with thickness 1 QL (quintuple layer ~ 1 nm) and films of millimeter-scale with thicknesses 2–6 QL had been grown on CVD graphene. The minimum thickness of large-scaled continuous Bi2Se3 films was found to be ~ 8 QL for the regime used. The heterostructures with a Bi2Se3 film thickness of > 10 QL had resistivity as low as 200–500 Ω/sq and a high room temperature carrier mobility ~ 1000–3400 cm2/Vs in the Bi2Se3/graphene interface channel. Moreover, the coexistence of a p-type graphene-related conductive channel, simultaneously with the n-type conductive surface channel of Bi2Se3, was observed. The improvement of the bottom Bi2Se3/graphene interface with the increase in the growth time clearly manifested itself in the increase of conductivity and carrier mobility in the grown layer. The grown Bi2Se3/G structures have lower resistivities and more than one order of magnitude higher carrier mobilities in comparison with the van der Waals Bi2Se3/graphene heterostructures created employing exfoliation of thin Bi2Se3 layers. The grown heterostructures demonstrated the properties that are perspective for new functional devices, for a variety of signal processing and logic applications. [ABSTRACT FROM AUTHOR]

The paper presents a technique for calculating information-correlation characteristics based on the methods of average mutual information and two-dimensional detrended fluctuation analysis. The experimental samples are structures with an array of self-organized InAs/GaAs quantum dots grown without a cover layer by gas-phase epitaxy from metalorganic compounds. The microstructure of the sample surfaces is studied by scanning electron microscopy. The information-correlation characteristics of InAs/GaAs structures with quantum dots are obtained using two-dimensional detrended fluctuation analysis and average mutual information. The order of the array of quantum dots in the InAs/GaAs structure is estimated depending on the applied technological modes of production. It is found that increasing the growth temperature of the experimental samples from 480 to 520°C increases the ordering of the location of quantum dots on the surface. [ABSTRACT FROM AUTHOR]

Differences between sexes contribute to variation in the levels of fasting glucose and insulin. Epidemiological studies established a higher prevalence of impaired fasting glucose in men and impaired glucose tolerance in women, however, the genetic component underlying this phenomenon is not established. We assess sex-dimorphic (73,089/50,404 women and 67,506/47,806 men) and sex-combined (151,188/105,056 individuals) fasting glucose/fasting insulin genetic effects via genome-wide association study meta-analyses in individuals of European descent without diabetes. Here we report sex dimorphism in allelic effects on fasting insulin at IRS1 and ZNF12 loci, the latter showing higher RNA expression in whole blood in women compared to men. We also observe sex-homogeneous effects on fasting glucose at seven novel loci. Fasting insulin in women shows stronger genetic correlations than in men with waist-to-hip ratio and anorexia nervosa. Furthermore, waist-to-hip ratio is causally related to insulin resistance in women, but not in men. These results position dissection of metabolic and glycemic health sex dimorphism as a steppingstone for understanding differences in genetic effects between women and men in related phenotypes. Sex differences in fasting glucose and insulin have been identified, but the genetic loci underlying these differences have not. Here, the authors perform a meta-analysis of genome-wide association studies to detect sex-specific and sex-dimorphic loci associated with fasting glucose and insulin. [ABSTRACT FROM AUTHOR]

New results of a detailed study of the deep structure of the Central Tien Shan along the Son-Kul magnetotelluric (MT) profile crossing the Son-Kul Lake are reported. Based on the results of magnetotelluric data modeling, the regional and local geoelectric anomalies in the lithosphere are studied and their quantitative characteristics are given. Geological interpretation of the geoelectric cross-section was carried out, which supported the existing ideas about the block–hierarchical structure of the upper part of the Earth's crust. This corresponds to the tectonophysical concepts of the sequential inserted subordination of large and smaller elements of the zone–block structure consisting of stable blocks and limiting mobile zones, which are distinguished by the high dislocation of the geological substrate. The integral pattern of the distribution and morphology of zones of high electrical conductivity in this segment of the Central Tien Shan crust may reflect discretely localized palm tree–type structures associated with the evolution of transgressive suture zones of localized deformation during the Hercynian and Alpine tectogenesis. [ABSTRACT FROM AUTHOR]

A class of linear systems described by rational transfer functions with interval parameters and fixed time-delay values is considered in this study. The ranges of variation of the interval parameters depends on the total range of perturbations. A sufficient frequency criterion for robust modality is formulated. This criterion is determined by the inclusion of all the roots of a system characteristic quasi-polynomial to the region located to the left of the given position of the vertical boundary. The advantage of the developed criterion in comparison with similar ones is the possibility of refusing to analyze the set of characteristic quasi-polynomials of the system, as well as refusing to analyze the nominal system. This provides by constructioning and studying only two hodographs. In special cases, the developed criterion coincides with the known frequency criteria for system analysis. [ABSTRACT FROM AUTHOR]

A CCDS2000 detonator for acetylene, ethylene, propylene, and a multicomponent methylacetylene–allene fraction (MAF) fuel is used to perform experiments on measuring the detonation velocity and recording a detonation front cell in a tube 26 mm in diameter and 2 m in length. The experiments are carried out at atmospheric pressure in stoichiometric mixtures diluted by nitrogen to air concentrations and in air–fuel mixtures with a varying fuel content in them. In the case where the explosive mixture components are fed as a flow by stratifying an explosive charge in an initiation zone, a self-sustaining detonation is stably ignited up to limiting (spin) modes. The concentration limits of the detonation existence are determined. In the air–fuel mixtures of acetylene and ethylene, as the values become lower than the limits, there is multiheaded detonation. For propylene and MAF, a tube diameter of 26 mm is near-critical: only single- and two-headed spin is observed in the entire range of existence. Calculation results are in good agreement with the experiment. [ABSTRACT FROM AUTHOR]

The ability to reduce the rise time of a voltage pulse formed by a high-voltage pulse generator in a gyromagnetic line due to the excitation of a gyromagnetic precession of the magnetization vector of a saturated ferrite is demonstrated. At a load of 50 Ω, voltage pulses with a rise time of 135–140 ps, an amplitude of 170 kV, and a pulse repetition frequency of 300 Hz were obtained. The generator circuit is described and the results of experiments are presented. [ABSTRACT FROM AUTHOR]