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The analysis of amplitude spectra from a thin polystyrene-based scintillation counter on muon-enriched and hadron beams of channel 18 of the U-70 accelerator complex in Protvino has been presented. On the basis of statistics of 150 million events on the Hyperon-M setup, the contribution of the -fragmentation processes are highlighted and the cross sections of these processes on hadron and pion beams with a momentum of 7 GeV/c have been measured. In the future, the obtained result may be of interest for the method of analyzing the age of gas fields based on the concentration of helium in natural gas, the formation of which is possible in the reaction of fragmentation of carbon nuclei in interactions induced by high-energy cosmic muons. [ABSTRACT FROM AUTHOR]

Studies at the Nuclotron in JINR indicate the presence of a previously unknown resonance-like structure in the two-photon mass spectrum in the region of 300–400 MeV/c2, observed in nucleus–nucleus interactions. The goal of this work is to search for such structures in the two-photon mass spectrum in meson–nuclear interactions at a momentum of 7 GeV/c at the Hyperon-M experiment of the U-70 accelerator complex. An upper limit has been established on the ratio of the cross section for the formation of unknown resonance structures to the cross section for the production of -meson at the 95% confidence level. [ABSTRACT FROM AUTHOR]

Using the method of high-temperature chemical synthesis, material samples with a high-temperature protection system were fabricated. The study of the thermochemical effect of high-enthalpy air flows on a carbon-containing composite material with a high-temperature antioxidant coating based on hafnium compounds at surface temperatures of 1400–1600°C was carried out in a free subsonic jet of high-enthalpy air of a VGU-4 100-kilowatt high-frequency induction plasma torch. The experiments were carried out at a pressure of 100 hPa in a stepwise heating mode and in a constant surface temperature mode of 1400, 1500, and 1600°C. The duration of each test cycle in the constant temperature mode was 1500 s. [ABSTRACT FROM AUTHOR]

According to modern theories, the parameters of neutral mesons such as their mass and width are closely connected with the medium in which the mesons are present. Experimental data on the study of mesons in a nuclear medium are in demand for development of theoretical models describing processes in the field of nonperturbative quantum chromodynamics (QCD). Masses and widths of neutral mesons produced in meson-nucleus interactions on various nuclei are measured in the Hyperon-M experiment at the U70 accelerator. The paper describes a method for precision measurement of the parameters of neutral mesons, presents the results on measurement of the mass and width of the meson and preliminary results on the measurement of the mass and width of the meson. The measurements indicate the absence of dependence of the quantities under study on the nuclear environment. [ABSTRACT FROM AUTHOR]

The study aimed to reveal neurophysiological markers of the effects of transcranial direct current stimulation (tDCS) in children with speech disorders, learning disability, emotional and communicative problems, etc. Comparative EEG studies were carried out in eyes-closed and eyes-open resting conditions in children aged 3–8 years: in the control group without developmental lags (28 children) and in the group with mental development disorders (after conventional treatment—27 children, after tDCS treatment—28 children). A significant increase in alpha peak frequency in the occipital cortex and a decrease in the spectral power of the slow (θ) activity in the occipitoparietal cortex in the left and right hemispheres after tDCS were shown. This indicates a systemic influence of local tDCS on the brain function both in the stimulated and contralateral hemispheres. These EEG parameters are more similar to those in the control group than in children with mental development disorders without tDCS. The data obtained are interpreted as neurophysiological markers of tDCS effects (formation of the age-related dynamics of EEG rhythms in children with mental development disorders). A higher efficiency of the first tDCS session in 494 children was found in the case of tDCS applied near the cortical projection of the Wernicke's area in the left hemisphere (systemic effect on speech, motor functions, behavior, emotional sphere, etc). [ABSTRACT FROM AUTHOR]

The results of experimental studies on the fabrication of prototypes of ceramic composite cladding elements of the flame tube for a combustion chamber are presented. The structure and physicomechanical properties of the prototype samples were investigated. High-temperature bench tests of prototypes were performed as part of an experimental sample of a flame tube with a similar design. [ABSTRACT FROM AUTHOR]

The modification of the spectral function of vector mesons in nuclear matter is predicted in many theoretical models. However, the existing experimental results for testing these models are contradictory. Possible effects of the modification of the mass and width of ω mesons produced in the collisions of 7-GeV/c positively charged mesons with C, Be, Al, Cu, Sn, and Pb nuclear targets have been sought in the Hyperon-M experiment. The measured mass and width of ω mesons produced on the indicated nuclei are in agreement with each other with a high accuracy, which does not confirm the theoretical models predicting modification of the mass and/or width of the ω meson in nuclear matter. [ABSTRACT FROM AUTHOR]

The prospects for using ceramic composite materials in place of metallic materials in heat-loaded units in advanced aircraft are examined. The manufacture of silicon carbide based ceramic composite materials, reinforced with filamentary crystals (whiskers), by means of hot-pressing and spark plasma sintering using oxide and nitride sintering additives was investigated. A complex of physical-mechanical and thermal properties of composites was investigated. [ABSTRACT FROM AUTHOR]

Data from neurophysiological examinations were summarized for children with mental development disorders of perinatal genesis. Hypothetical sources of slow activity were found in the frontotemporal cortex bilaterally. An increase in the power of slow components was shown to correlate with the severity of mental developmental disorders. New data were obtained to indicate that local and distributed ("global") sources of EEG rhythms have a potential as neuromarkers of psychoverbal retardation in early ontogeny. A high level accuracy was observed for a classification of the children on the basis of these potential neuromarkers. [ABSTRACT FROM AUTHOR]

The task of guidance of a spacecraft, returning from the Moon, to a given landing area, under an effect of "magnified" disturbing factors, is considered. The earlier developed terminal algorithm for control of the descent from a near-Earth orbit was substantially modified, as applied to skip trajectories, with two entries into Earth's atmosphere, in order to meet the given restrictions on landing accuracy, load factor, and propellant consumption. The modified version of the algorithm includes the "separate" logic of adaptation to the real conditions of motion, with measuring the components of apparent acceleration. The reliability of results is confirmed by a large volume of statistical tests. [ABSTRACT FROM AUTHOR]

The electrical conductivity of a series of LiNbO3 crystals grown from the charge of the congruent composition with relatively low iron concentration (up to 0.15 wt % Fe2O3) has been studied experimentally. It is found that, at temperatures close to 300 K, the main contribution to the electrical conductivity of these crystals is from two types of the centers with close activation energies. The first type of centers are Fe2+ ions, which determines the impurity electron conductivity with the activation energy (0.34 ± 0.01) eV. The second type of centers are polarons of small radius with the activation energy (0.29 ± 0.02) eV. The polaron conductivity is shown to be dominate for nominally impurity-free and low-doped "as-grown" LiNbO3 crystals at T = 300 K. [ABSTRACT FROM AUTHOR]

The variations of electrical conductivity and the primary pyroelectric coefficient with temperature for lithium niobate (LiNbO3) crystals grown from melt containing K2O flux are studied in the range of 292–450 K. These crystals are found to exhibit considerable anisotropy of electrical conductivity, and the proton conductivity is dominant in the studied temperature range. [ABSTRACT FROM AUTHOR]

The EEG power spectra in the main bands (4 to 20 Hz) were compared during transcranial direct current stimulation (tDCS) treatment in children with mental development disorders of perinatal origin. In resting state with the eyes closed, a shift in the average frequency of α activity in the parieto-occipital area (from 9 to 10 Hz) and an increase in the spectral power stronger in the right hemisphere were observed. With the eyes open and closed, a decrease in the β range power spectrum in the right posterior temporal cortex was observed in children undergoing tDCS treatment. The power spectra of θ activity with a frequency of 4–5 Hz in the left posterior-temporal area with the eyes open showed negative correlation with age. [ABSTRACT FROM AUTHOR]

The problem of reentry vehicle control during its descent from a near-Earth orbit is considered under conditions of "enhanced" disturbances. The earlier developed terminal descent control algorithm is considerably improved to satisfy constraints on landing accuracy, load factor, and propellant consumption. A method for automatically shifting the deorbit point, adaptating to actual motion conditions, and modifying the reference bank function is proposed, which ensured the satisfaction of the specified constraints under action of an aggregate of enhanced disturbing factors. [ABSTRACT FROM AUTHOR]

The NMR spectra of several heterocyclic compounds synthesized at Omsk universities revealed manifestation of a diasteomerism at a large (up to fifteen bonds) distance between the stereogenic centers. This phenomenon was explained by a regular helical secondary structure of the tether between the centers. [ABSTRACT FROM AUTHOR]

Spark plasma sintering was used to obtain experimental samples of ceramic composite materials in the system SiC-ZrB2 with graphite and aluminum nitride as additives. The physical and mechanical properties of composites (density, strength in bending, hardness, cracking resistance) were studied as a function of the production temperature parameters. The microstructure of the materials was studied and x-ray spectral microanalysis was performed and the oxidation resistance of the obtained samples at 1500°C was determined. [ABSTRACT FROM AUTHOR]

Water wetting films on a quartz surface were found to become unstable with increasing temperature. This is believed to be associated with the temperature dependence of the structure of the water in the layer at the wall. Aparameter characterizing the strength of the structural forces is calculated from measurements of the contact angle. The sign inversion of the parameter is associated with the forces of hydrophobic attraction predominating over the forces of hydrophilic repulsion in a definite temperature interval. The results of deferrization of glass quartz sands by flotation during thermal action on water wetting films are presented. [ABSTRACT FROM AUTHOR]

Longitudinal analysis of the spectral power of the main EEG bands was performed in the wakeful state with the eyes open and the eyes closed in children with mental disorders at various stages of correction by transcranial direct current stimulation (tDCS). A significant increase in the power of α-rhythm in the parietal-occipital areas and a significant decrease in the slow wave activity in the left frontotemporal areas were observed in the course of the correction process. The data obtained can be considered as the neurophysiological markers of the tDCS effects (formation of age-related EEG parameters in children with mental disorders). The data also prove the relations between the described phenomena and the cortical mechanisms of speech disorders and other psychic processes caused by perinatal CNS disorders. [ABSTRACT FROM AUTHOR]

Dynamic NMR was applied to measuring the value ΔG characterizing the height of the barrier to the pyramidal inversion of the nitrogen atom in carbamate and thiocarbamate anions formed at the reaction of 2-aminoethanol with CO and COS. The refinement was introduced in formerly suggested cyclic structures of anions containing an intramolecular hydrogen bond NH···O(S), which contradicted the found large values of the barrier of inversion (Δ G ∼ 70 kJ mol). The hydrogen bond in the cyclic anions of carbamates and thiocarbamates is two-electron and three-center. Analogous cyclic structure with a multicenter hydrogen bond does not form in the case of dithiocarbamate anion that is the product of 2-aminoethanol reaction with CS. [ABSTRACT FROM AUTHOR]

For any prime p, we prove the existence of non-compactly supported orthogonal p-adic wavelet bases in the Hilbert space L2 (Qp), and construct the first explicit example of such a basis. The reasons are based on a special parametrization of the set of eigen standard Haar vector-functions. It should be noted that all previously known orthogonal p-adic wavelet bases were modifications of the p-adic Haar basis. [ABSTRACT FROM AUTHOR]

A technological complex was developed in order to remove clay minerals, iron oxide, and fractions heavier than 2.9 tons/m from glass quartz sands. The basis of the scheme of the apparatus chain of the complex consists of a trammel screen with a new design, jigs, and concentration tables with electromagnetic inductors. It was shown under laboratory conditions that sand in the highest demand - VS-030-V grade - was obtained from sands containing (by weight): 97.32% SiO, 0.92% AlO, 0.43% FeO, 0.11% TiO, and 0.04% CrO. A distinguishing feature of the technological scheme of gravity separation of sands is the counterflow motion of the initial feed and the heavy fraction. [ABSTRACT FROM AUTHOR]

An apparatus for determining the wettability of quartz sand was developed. It was shown that as the temperature increases, the surface wettability of the minerals present in the glass quartz sand increases owing to a reduction of the slippage of the liquid along the solid surface and, in consequence, the aggregative stability of their suspensions increases. [ABSTRACT FROM AUTHOR]

A variety of different orthogonal wavelet bases has been found for L 2 ( R ) for the last three decades. Such bases are not only interesting by themselves, a number of theoretical and applied problems were solved using them. It appeared that similar non-trivial wavelet constructions also exist for functions defined on some other algebraic structures, such as local fields of positive characteristic including the Vilenkin/Cantor groups. We note that most of the bases involved consist of Bruhat–Schwartz functions, i.e. compactly supported and band-limited ones. There were several attempts to develop wavelet theory in a more general setting, e.g., for zero-dimensional groups. Analyzing these papers, one can see that actually nothing except for the Haar basis and its trivial modifications was constructed. In the present paper we give an explanation for these failures. Namely, we describe the situation for the field Q p of p -adic numbers and prove that any orthogonal wavelet basis for L 2 ( Q p ) that consists of band-limited (periodic) functions, is a modification of the Haar basis. [ABSTRACT FROM AUTHOR]

A description is given of the TDMS diagnostic system that has been introduced on the FTOHBR-150200/35 transformers of 180-ton arc steelmaking furnaces at the Magnitogorsk Metallurgical Combine. The complete circuit diagram of the system is also presented. The modular principle of construction of the system is validated and the functions of the modules of primary transducers are examined. The article presents the characteristics of the Minitrans diagnostic complex for monitoring the gas and moisture contents of transformer oil and the TAP-Monitor instrument for monitoring and diagnosing the technical condition of load-voltage regulators. It also includes diagrams of the changes in the recorded parameters over time and shows the on-screen formats of the integral diagnostic characteristics. The technical-economic expediency of introducing the TDMS system is demonstrated. [ABSTRACT FROM AUTHOR]

This article describes the specifications of the FTOHBR-150200/35 transformers that are made by the company TAMINI and were installed on 180-ton arc steelmaking furnaces (DSP-180 furnaces) in the electric steelmaking shop at the Magnitogorsk Metallurgical Combine. It also gives the specifications of the ETTsNKV - 40000/110 transformers that are made by the Elektrozavod company and were installed on ladle-furnace units in the same shop. Features of the loading regimes of the furnace transformers are discussed and are taken into account in substantiating the diagnostic functions of a system to continuously monitor transformers' technical condition. The requirements that were established have been used to design systems for on-line monitoring of the DSP-180 transformers. [ABSTRACT FROM AUTHOR]

Baseline EEGs in the frequency range of 3-13 Hz in children with mental disorders of perinatal origin during wakefulness with the eyes open were analyzed using independent component analysis. In cases of severe mental retardation, a significant increase in the power density spectra of the θ band was revealed in the left-sided frontotemporal and right-sided temporal cortices, which allows us to consider these regions to be putative sources of slow activity and markers for a lesion or immaturity in the fronto-thalamic system, as well as for the temporal areas responsible for the auditory analysis and synthesis of speech signals and the integration of audio-visual information. [ABSTRACT FROM AUTHOR]

In 2007, A. L. Smirnov formulated an interesting conjecture on the generalized rings introduced and studied by N. V. Durov. In this paper, the conjecture is proved. [ABSTRACT FROM AUTHOR]

The authors study potential utilization of oil tailings of a lead-zinc processing plant. Conversion of sulfides into marketable selective concentrates is carried out in two stages: sulfide product is extracted from tailings, first, and processed, second, jointly with current ore material, using the accepted technology, or separately, by jet flotation. Sulfides are extracted from tailings using a channel-type hydroseparator. A feature of flotation scheme is stream counterflow of feed (in both cycles) and rough concentrate. Conditions and composition are developed for manufacturing a quality product from non-metal tailings: lime-sand bricks, glass containers, fiberglass and marbled glass. [ABSTRACT FROM AUTHOR]

The π0, η, K0, ω, and f2(1270) masses were measured at the HYPERON-Msetup in meson-nucleus interactions at a momentum of 7 GeV/ c by using six nuclear targets: Be, C, Al, Cu, Sn, and Pb. The experiment in question proved to be insensitive to the expected effects of a modification to the omega-meson mass in nuclear matter. As for the f2(1270) meson, its mass and width values averaged over all experimental data, $$m_{f_2 }$$ = 1275.8 ± 1.0(stat.) ± 0.4(syst.) MeV/ c2 and $$\Gamma _{f_2 }$$ = 190.3 ± 1.9(stat.) ± 1.8(syst.) MeV/ c2, agree well with the world-average values. At the same time, our experimental data do not rule out the possible effect of an in-medium modification to the f2(1270)-meson mass for heavy nuclei at a level better than 0.4%. [ABSTRACT FROM AUTHOR]

A family of Haar multiresolution analyses is constructed in the Hilbert space L( $$ {\mathbb A} $$), where $$ {\mathbb A} $$ is the ring of adeles over the field ℚ of rationals. The corresponding discrete group of translations and the scaling function are, respectively, the group of additive translations by elements of ℚ embedded diagonally in $$ {\mathbb A} $$ and the characteristic function of the standard fundamental domain of this group. As a consequence, a family of orthonormal wavelet bases in L( $$ {\mathbb A} $$) is obtained. Note that both the number of generating wavelet functions and the number of elementary dilations are infinite. Bibliography: 7 titles. [ABSTRACT FROM AUTHOR]

The way that the difference in the refractive indices of lithium niobate crystals changes upon the rapid heating of a sample with electroconductive masks deposited on its surface has been studied. It is shown that the phenomena observed are fully described by the pyroelectric effect in the presence of temperature gradient on polar surfaces of the sample. [ABSTRACT FROM AUTHOR]

We prove that for a sufficiently closed association scheme, the Brouwer conjecture on the coincidence of the vertex connectivity and the degree of any its connected basis relation is true. [ABSTRACT FROM AUTHOR]

We announce an explicit form of the standard basis for the 2-extended ring associated with the cellular ring generated by the incidence graph of a finite projective plane. This enables us to give the first example of a distance-regular graph that satisfies the 6-condition and is not distance-transitive. One more consequence of the result obtained is that the cellular rings of any two projective planes of the same order are 2-isomorphic. This implies that, if for some order there exist at least two nonisomorphic and nondual to each other projective planes, then the separability number of the cellular ring of any projective plane of this order is greater than or equal to 3 and, moreover, it is equal to 3 for a Galois plane. Bibliography: 9 titles. [ABSTRACT FROM AUTHOR]

Flotation by a vapor-air mixture in a 'two streams' scheme was used to de-iron unconditioned sands with 0.34 wt.% FeO: the foam product of the flotation stream I is separated from 1/2 of the sands and mixed with the other 1/2 of the sands by flotation stream II. A distinguishing feature of flotation stream II is that a mixture of air with hot (> 100°C) water vapor is used as the gas phase, which yields VS-030-V grade sand. The consumption of the warming vapor in the vapor-air flotation technology equals 9.7 × 10 Gcal/ton of sand. [ABSTRACT FROM AUTHOR]

We studied a biomaterial for a new domestic product, a biological envelope for implantation of cardiac electronic devices. The product is designed to prevent complications after pacemaker implantation and to facilitate the reimplantation procedure. By chemical and biological processing of raw materials (submucosa of porcine small intestine), an acellular extracellular collagen matrix was obtained. The biocompatibility of the material was tested in vitro using stem cell cultures. The biomaterial for fabrication of the envelope is not cytotoxic, biocompatible, and represents a suitable substrate for attachment, growth, and reproduction of stem cells. The biological effect of the material was studied in vivo on the model of heterotopic implantation in small laboratory animals. The biomaterial did not induce inflammation and tissue reaction and was completely transformed into healthy vascularized tissue without scars in 90 days after implantation. [ABSTRACT FROM AUTHOR]

The optimal characteristics of porous samples based on SiC powders are determined, enabling us to obtain defect-free siliconized materials. A composition for a silicon-carbide ceramics joint with the composition SiO2-Al2O3-Y2O3 (38:27:35 wt.%) is selected based on data of DSK analysis and experiments on wetting of SiC substrates using the stationary drop method, enabling us to obtain a stable SiC ceramic joint without visible fractures or pores by means of spark plasma sintering (SPS/FAST) accompanied by simultaneous induction heating. [ABSTRACT FROM AUTHOR]

Problems concerning reduction of the dynamic loads on the horizontal and vertical rolls of universal rolling-mill stands are examined. The unacceptably large shock loads that develop in the equipment of the vertical stand when the strip is captured by the rolls of the horizontal stand are illustrated by using the example of the electric drives of the stands in the continuous subgroup of the roughing train in a 2000 hot-wide-strip mill at the Magnitogorsk Metallurgical Combine. A method is proposed for reducing these shock loads by automatically matching the speed at which the strip leaves the preceding vertical stand to the speed at which the strip is captured by the succeeding horizontal stand. A method is also examined for correcting the speed of rotation of the vertical-stand rolls based on the difference between the currents of the electric drive during free rolling of the strip and its simultaneous rolling in both stands. Oscillograms that are presented confirm the effectiveness of the proposed control methods, and recommendations are given for their industrial use. [ABSTRACT FROM AUTHOR]

The problems of developing high-temperature composite materials for aerospace engineering and methods for obtaining them as well as their advantages over the technologies widely used abroad are examined. [ABSTRACT FROM AUTHOR]

The stability of a new single-domain therapeutic antibody to the ErbB3 receptor was studied by fluorescence spectroscopy at different concentrations of a denaturing agent and temperatures. The analysis of experimental denaturation curves allowed us to build a complete thermodynamic model of unfolding and to determine all parameters of the transition: Δ G = 8.5 kcal mol, T = 76°C, Δ H = 107 kcal mol, Δ C = 1.8 kcal K mol. The obtained data evidence the high stability of the antibody in a broad range of conditions, which is essential for further structural and functional studies and possible therapeutic application. [ABSTRACT FROM AUTHOR]

The operating principle of a microelectromechanical self-vibrating system based on a string sensing element with the use of monocrystalline silicon and piezoceramic films is described. Results of preliminary (qualitative) modeling of such a system are presented and its distinctive features are described. [ABSTRACT FROM AUTHOR]

The electrical conductivity of single crystals of lithium tantalate and lithium niobate of the congruent composition not subjected to special thermochemical treatments has been investigated in the temperature range of 290-450 K. It has been shown that the charge transfer mechanisms and carrier types in these crystals are identical in the temperature range under study. The presence of mobility anisotropy of conduction electrons has been revealed and its influence on the recording and storage of optical phase holograms in these crystals has been established. [ABSTRACT FROM AUTHOR]

We have studied anisotropic electrical conductivity and dielectric properties of a LiTaO crystal in the temperature range 290-900 K. The anisotropy in its dielectric characteristics is associated with specific features of dielectric relaxation in the polar and nonpolar directions of the crystal. In the temperature range 290-450 K, the electrical conductivity in a nonpolar direction slightly exceeds that in the polar direction and there is anisotropy in electron mobility μ. At temperatures from 600 to 900 K, conductivity anisotropy shows up in both the magnitude of conductivity and the energetic and kinetic characteristics of charge transport processes. [ABSTRACT FROM AUTHOR]

The results of studies on the developmental EEG dynamics in children with long-term effects of perinatal CNS pathology are presented. The most common EEG types have been identified, and the differences in their distribution in normal and abnormal mental development were shown. On the basis of the results of a longitudinal study, early markers of the risk of ontogenetic deviations have been described that allow the consequences of perinatal CNS lesion to be minimized and abnormal variants of the formation of higher mental functions to be prevented. [ABSTRACT FROM AUTHOR]