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The paper presents correlation-regression analysis of the influence of various factors on the oil production rate of wells with horizontal completion. Attempt was taken to create a model of multiple correlation for explaining the combined effect of these factors on production rate. The model allows both predicting with sufficient accuracy rate the production rate of the well based on drilling and completion data with a sufficiently high proportion of accuracy, and ranking various factors according to the degree of their influence on production rate.

The article presents an analysis of resources that can be used to test users who study the SQL language. Also, the article describes plan and result of the attack on web applications for learning the SQL language. There are some weaknesses of web applications in terms of their ability to verify the correctness of the compilation of SQL queries, which are also describes here. The conclusion deals with is made about the expediency of developing a specialized test system for verifying the correctness of writing SQL-queries.

Analysis of the Russian and foreign expertisein optimizing the drilling process suggeststhe need to develop new methods for solving the problems associated with the process of drilling directional wells, in order to prevent possible complications and on their basis solvethe optimization problems in the field of drilling, which seems a relevant scientific and practical task.

The effect of thermal annealing performed in the temperature range 400–800°С on the hydrolytic durability of borobasalt systems containing simulated radioactive waste from pyroelectrochemical technology was studied. Three types of simulated waste were examined: type 1, waste from reprocessing of reactor-grade plutonium; type 2, waste from reprocessing of weapons-grade plutonium; type 3, waste from gallium recovery from type 2 waste (virtually pure americium phosphate). Depending on the waste type and temperature, annealing can both increase and decrease the host material leach rate.

Ovarian carcinomas (OC) often demonstrate rapid tumor shrinkage upon neoadjuvant chemotherapy (NACT). However, complete pathologic responses are very rare and the mechanisms underlying the emergence of residual tumor disease remain elusive. We hypothesized that the change of somatic BRCA1 status may contribute to this process. The loss-of-heterozygosity (LOH) at the BRCA1 locus was determined for 23 paired tumor samples obtained from BRCA1 germ-line mutation carriers before and after NACT. We observed a somatic loss of the wild-type BRCAI allele in 74% (17/23) of OCs before NACT. However, a retention of the wild-type BRCA1 copy resulting in a reversion of LOH status was detected in 65% (11/17) of those patients after NACT. Furthermore, we tested 3 of these reversion samples for LOH at intragenic BRCA1single nucleotide polymorphisms (SNPs) and confirmed a complete restoration of the SNP heterozygosity in all instances. The neoadjuvant chemotherapy for BRCA1-associated OC is accompanied by a rapid expansion of pre-existing BRCA1-proficient tumor clones suggesting that continuation of the same therapy after NACT and surgery may not be justified even in patients initially experiencing a rapid tumor regression. (C) 2017 Elsevier B.V. All rights reserved.

The hypothesis of the huge optical nonlinearity of the crystalline TeO3, recently advanced on the basis of the quantum-mechanical simulations, is tested. Electronic band gaps of α-TeO2 and β-TeO3 crystals are determined by diffuse reflectance measurements. The DFT+U method is applied to calculate electronic band gap Eg and the third-order nonlinear dielectric susceptibility χ(3). The χ(3)(TeO3) is about two times lower than the χ(3)(TeO2) in spite of the fact that the Eg(TeO3) is narrower than Eg(TeO2). It is shown that this peculiarity is related to the 5s(Te) electronic states which are occupied in TeO2 and are vacant in TeO3. This distinction is due to the specific electronic state related to the electron lone pairs localized on the Te(IV) atoms.

The comparative analysis of primary sedimentary and secondary catagenetic dolomites revealed that they differ in many typomorphic properties. Sedimentary dolomites are characterized by the pelitomorphic and fine-grained structure, high stoichiometry, and presence of the electron-hole (p-n) centers [SO2]– and [SO3]– in the structure. Secondary dolomites have a fine- to medium-grained structure and distinguished by a lower degree of stoichiometry. Their crystal lattice shows isomorphous replacements Mg ↔ Fe and Mg ↔ Ca. They can be divided into two (massive and porous) varieties. The massive varieties are characterized by the conformal structure and xenomorphic habitus of the closely packed idiomorphic and hypidiomorphic grains. The Ca–Mg and Fe–Mg isomorphism in the massive dolomites is less expressed than in the porous varieties. These specific features of dolomite varieties are related to their different formation settings. The porous dolomites were formed in a free environment that fostered slow growth of the relatively large equant crystals with a high degree of isomorphism, whereas the massive dolomites were formed under “stringent constraints” during a faster growth of crystals.

At cementing of casing of oil and gas wells during the process of injecting of cement slurry in the casing column the slurry can move with a higher speed than it’s linear injection speed. A break of continuity of fluid flow occurs, what can lead to poor quality isolation of producing formations and shorten the effective life of the well. We need to find some technical solution to stabilize the linear velocity of the cement slurry in the column. This task can be resolved with an automated control system.

The technique for calculatingmaterial characteristicswith the aid of theHartree–Fock–Roothaan method in the CO LCAO approximation using the cyclic clustermodel is considered. The results of the numerical study are verified for the TiO2 system. The band gap minimum (2.9 eV) is calculated for the system under consideration.

The economic efficiency of dirigibles for intercontinental tourism is assessed. The capabilities of dirigibles are established, and the specifics of tourist operation for a particular dirigible are considered. The basic measure of efficiency is selected. Economic analysis permits conclusions regarding such uses of dirigibles.

The using possibility a unipolar corona discharge to improve the range of paper ashless filters operational properties has been investigated. It was revealed that the samples treatment by corona discharge led to an increase in the purity of the test filtrate, as well as to an increase in the strength characteristics of paper ashless filters.

Multimode 940-nm diode radiation is shown to be converted in graded-index fibers into high-quality (M2≤2) 976-nm Raman beam due to parabolic pump beam, its homogeneous depletion above threshold, mode-selective feedback by FBG and nonlinear effects.

Anthropogenic activity causes the introduction of zinc compounds into the biological cycle in mining and processing sites and its accumulation in organs and tissues, causing systemic toxicity. A cumulative effect of zinc is predominantly neurotoxic and it also affects the respiratory, cardiovascular and digestive systems. This study evaluates the effects of single-dose intragastric administration of 100 mg/kg zinc succinate on the structure and function of organs and tissues in male Wistar rats 1 month after treatment. The presented morphofunctional approach for the toxicity evaluation included the study of behavioral responses using the automated Laboras® complex, fluorescent spectral analysis of the NADH and FAD activity and histological evaluation of animal organs and tissues. The results of the behavioral activity assessment showed a significant decrease in animals’ motor activity, whereas the fluorescence spectra analysis demonstrated a decrease in coenzyme NADH without the reduction of FAD levels. We detected toxic and dystrophic changes in the cerebral cortex, heart, lungs and liver tissues. Our original multiparametric approach enables a comprehensive assessment of the long-term toxic effects of the metal salts such as zinc succinate, especially in the cerebral cortex at the doses much lower than the acute LD50 reported for the common zinc salts., Zinc succinate; Tissue and organ toxicity; Morphofunctional approach; Behavioral activity; Endogenous fluorescence; Experimental rats; Health Sciences; Neuroscience; Psychiatry; Toxicology.

The article analyzes the research results of a number of analytical agencies regarding the growth rate and key problems associated with the introduction of the “Internet of things” (IoT) in the agricultural economy. The issues of the development of the agro-industrial complex in the context of the development of the digital economy, the experience of introducing the digital economy in the agricultural sector of developed countries and the possibilities of its application in agriculture in Russia are considered. The authors focuses on the positive aspects of the influence of the “Internet of things” on the functioning and development of modern agricultural markets at the macro and micro levels, and the change in the professional structure of the agricultural industry

The article emphasizes that for the innovative development of the Russian agricultural industry and ensuring the national food security, it is necessary to create a research and development sector in the field of food production; reform the education system for the innovative development of the agricultural industry; re-equip the agricultural industry; build a system of agricultural advisory support for producers; create an intellectual property protection system; improve legal standards for regulating innovation, research and development; pay attention to the needs of agriculture and agro-business, etc.

Ensuring the reliable and efficient operation of the reciprocating compressors in the wide range of the operating parameters is one of the important issues at designing, manufacture and operation of the compressor equipment. When designing reciprocating compressors for NGV-refueling compressor station the input pressure can vary from 0.15 to 12.0 MPa depending on the station location. Provision of the compressor serviceability in the wide ranges of parameter variations requires multivariate calculations in order to find the best design parameters of the compressor. The theoretical investigation of the gas initial parameters influence on the multistage reciprocating compressor operation process is represented in this study. Given here is the description of the intermediate pressure calculation method by compressor stages and the real gas properties calculation method. The comparison results of the compressor operation in different modes at compression of both the ideal gas and the real gas.

CARS is the one of most exciting and actively developed techniques for real-time monitoring of processes occurring in biological tissues. We present a fiber optical parametric oscillator pumped by specially designed MOPA fiber laser to get time-synchronized optical signals with a frequencies difference of 2800-3000 reverse centimeters. We utilize the fourwave mixing effect in a photonic-crystal fiber to build narrowband tunable fiber optical parametric oscillator. A complex optimization of each part of the source has been performed.

We report on the first demonstration of pulsed regime of Raman laser based on a multimode graded-index fiber directly pumped by a CW multimode laser diode. Proof-of-principle experiments have been performed with a 3.7-km multimode graded-index fiber with 62.5-μm core pumped by 976-nm high-power laser diode and cavity formed by bulk mirror and fiber Bragg grating with intra-cavity acousto-optic modulator providing Q-switching or mode locking. At 27.2-kHz repetition rate corresponding to the laser cavity round-trip frequency (i.e. in mode-locking regime), stable nanosecond pulses with peak power of ~300 W have been observed both at the 1st (1018 nm) and 2nd (1064 nm) Stokes orders. At that, the beam quality of generated pulses is greatly improved as compared to that for the pump diode (M2>20) reaching M2=2 for the 2nd-order Stokes wave.

Output beam characteristics of a LD-pumped multimode graded-index fiber Raman laser with different cavity configurations are studied. It has been shown that specially designed 976-nm FBGs inscribed by femtosecond pulses enable selection of an individual transverse mode: fundamental LP01 mode is generated in case of FBG localized in the center of graded-index fiber core, whereas next-order LP11 mode is generated in case of FBG shifted by ~8 um from the center. Corresponding beam shapes and spectra are observed in the laser output. At that, output power at the same pumping is sufficiently higher in case of LP11 FBG. Optimization of output characteristics is also performed resulting in generation of ~50 W power at 976 nm with beam quality parameter M2≈2.

Results of domestic D-mode pHEMT 0.5 µm process characterization obtained during the design and testing of the single power supply wide-band low noise amplifier (LNA) are present. The simulation and test results demonstrate that designed cascode LNA has operating frequency range up to 3.5 GHz, power gain above 15 dB, noise figure below 2.2 dB, output linearity above than 17 dBm and power consumption less than 325 mW. Potential immunity of LNA to total ionizing dose and destructive single event effects exceed 300 krad and 60 MeV·cm2/mg respectively.

Mode-locking (ML) is an established technique used to generate high power, ultrashort (ranging from ps to few fs duration) coherent light pulses in lasers. Mode-locking techniques could be classified into two broad categories. First one is passive mode-locking techniques in which modes are locked through dynamical intracavity self-organization processes not requiring extra energy sources. Another one is active mode-locking where locking between cavity modes is induced by external energy source. Active mode-locking could be either amplitude mode-locking (AML), for example achieved by a periodic (in time) modulation of the loss coefficient, or phase mode-locking (PML), for example via periodical modulation of the length/detuning of the cavity. In amplitude mode-locking periodic forcing induces synchronization of the cavity modes symmetrically coupled to the closest neighbors due to the action of the modulator: the spectrum broadens symmetrically, resulting in coherent frequency comb centered at the middle of the gain line, see Fig.1a.

In a circular economy, wood is a valuable product, the use of which must be rational. Integrated wood processing includes the use of production waste, for example, when sawing and planning. Raw materials for the production of pellets and fuel briquettes are sawdust, shavings, slabs. The production of second generation fuels is an extension of the life cycle of forestry and woodworking products. The production of pellets made by pressing crushed wood particles has changed the technology of energy use of wood in the ECE region. And, in turn, there was a need for specialists and new jobs.

Superconducting (SC) electrical machines could affect different industries due to their high power density. The most promising of them are fully superconducting machines. In the paper whole cycle of development of fully high temperature superconducting electrical machine is described: analytical calculation of magnetic field in the active zone of the machine, finite element modeling, some design features and experimental research of small-scale prototype. It is shown that theoretical and experimental results are in good correlation. Developed approaches could be used to develop high-power machines.

A technology for applying an anti-emission pyrocarbon coating by plasma-chemical gas-phase deposition to the grid electrodes of high-power electrovacuum devices has been developed. The plasma of a vacuum-arc discharge from a graphite cathode is simultaneously used for heating the grid electrodes, cleaning the grid electrodes from surface contamination, and for decomposing the reaction gas into active radicals. Experimental studies have shown that the satisfactory structure of the coatings and the adhesion of the coatings to the grid electrodes are provided at the temperature of the grid electrodes in the range from 550 to 1300 °C.

A multimode all-fiber Raman laser enabling cascaded generation of high-quality 1019-nm output beam at direct pumping by highly-multimode (M2>30) 940-nm laser diodes has been demonstrated. The laser is made of a 100/140 graded-index fiber with special in-fiber Bragg gratings which secure sequential generation of the 1st (976 nm) and 2nd (1019 nm) Stokes orders. Comparing different 1019-nm cavity structures shows that the half-open cavity with one FBG and distributed feedback via random Rayleigh backscattering provides excellent quality (M2∼1.3) with higher slope efficiency of pump-to-2nd Stokes conversion than in the conventional 2-FBG cavity. The maximum achieved slope efficiency amounts to about 40% at output powers of up to 12 W limited by the 3rd Stokes generation.

Background:Osteoarthritis (OA) relevance is determined by its record prevalence with progredient growth throughout the world [1]. Clinical and pathogenic heterogeneity of disease actualizes problem of its stratification [2]. Lack of unified understanding of OA and its phenotype determination results in incredible number of attempts to group OA, using of different classification criteria in last decade.Objectives:To analyze and systematize available OA classifications, proposals and phenotypes, to highlight the most promising of them.Methods:We studied publications from MEDLINE / PubMed and Google Scholar databases found by the keywords “osteoarthritis”, “phenotypes”, “subphenotypes”, “classification”, “subtypes”, “subsets”, “subgroups”, “subpopulations”, “profiles” and “endotypes” in various combinations in English and Russian. We did not set a time frame, but aimed to include as many different methods as possible in order to reflect evolution of scientists’ views on structuring of this disease.Results:A total of 55 OA grouping methods were covered so that OA was structured by different determinants into 6 big boxes.First OA classifications were characterized by complex etiopathogenetic approach, while subsequent studies differed in joint-mediated approach, and the knee joint was undisputed “champion” in this “race”. One of the first attempts to group OA was division into primary, or idiopathic, and secondary, due to known causes. It is now obvious that it is becoming obsolete, and criteria for OA primacy are difficult to determining. Genomic highly specialized studies based on isolation of “favorable” and “unfavorable” genes develops prerequisites to genetic OA classifying. Clinical variants occupy central place as they are the most fully consistent with modern phenotype conception [3], considerating as subtypes of disease shared by underlying pathobiological and pain mechanisms and their structural and functional consequences. Trajectories of OA progression are distinguished by longitudinal design, that is, the determinants for grouping here are disease characteristics in dynamics. The ancestor of structural OA trajectories can be considered Kellgren-Lawrence grades; subsequent studies identified complex of clinical, laboratory and morphological factors contributing to development of trajectories. Structural OA variants are diverse depending on visualization methods, and many of them can be naturally considered phenotypes, since they drive certain clinical OA manifestations. Morphological changes were described at macro- and microscopic levels; it is interesting to note the absence of histopathological norm in patients without OA. Laboratory profiles of patients are determined by content of systemic (serum, urinary) or local, “proximal” (in synovial fluid) biomarkers, which seem to be more precise. Metabolomic analysis is perspective new direction of laboratory studies based on joint metabolic products identification in the synovial fluid. New trend in OA research is molecular phenotyping. The specific molecular pathway explaining observed phenotype properties is called “endotype”. Endotype is related to certain pathobiological scenario, and laboratory markers are potentially effective for its diagnosis.Conclusion:Thus, a large amount of accumulated information and its diversity soon will probably lead to qualitatively new knowledge level with deep understanding of phenotype-associated strategy for managing OA patients.References:[1]Wallace IJ, Worthington S, Felson DT, et al. Knee osteoarthritis has doubled in prevalence since the mid-20th century. Proc Natl Acad Sci USA. 2017 Aug 29;114(35): 9332-9336. doi: 10.1073/pnas.1703856114 Epub 2017 Aug 14.[2]Deveza LA, Nelson AE, Loeser RF. Phenotypes of osteoarthritis: current state and future implications. Clin Exp Rheumatol 37 Suppl 2019;120(5):64-72.[3]Van Spil WE, Bierma-Zeinstra SMA, Deveza LA, et al. A consensus-based framework for conducting and reporting osteoarthritis phenotype research. Arthritis Res Ther. 2020;22(1):54. doi:10.1186/s13075-020-2143-0Disclosure of Interests:None declared.

We demonstrate an efficient conversion of highly-multimode (M2∼34) pump beam from fiber-combined 938-nm laser diodes into a 976-nm Stokes beam of high quality (M2=1.7-2 at output powers 10-52 W) that results in record brightness enhancement (BE=73) for Raman lasers based on graded-index fiber (GIF) and other fibers. The measured shapes of the output beams in GIF show that the near-parabolic pump beam becomes depleted above the Raman threshold so that the hole in the pump beam profile is much broader than the generated Stokes beam of near-Gaussian shape. The effect is analyzed in frames of a radially-dependent balance model with an account for the mode-selective feedback by FBG, which qualitatively describes the high-quality Stokes beam generation and the hole formation, but the hole width (and its power broadening) as well as the BE values are not consistent with experiment. Possible reasons for the difference are discussed.

A brightness-enhanced random Raman fiber laser (RRFL) with maximum power of 306 W at 1120 nm is demonstrated. A half-open cavity is built based on a graded-index (GRIN) passive fiber and single high-reflective fiber Bragg grating written in it directly. Due to the beam cleanup effect in the GRIN fiber enhanced in the half-open RRFL cavity, the output beam quality factor M 2 is improved from 9.15 (pump) to 1.76–2.35 (Stokes) depending on power, while the pump–Stokes brightness enhancement (BE) factor increases proportionally to output power reaching 6.1 at maximum. To the best of our knowledge, this is the highest power GRIN RRFL with BE.

The paper describes 3 cases of gallstone ileus. Epidemiological, morphological and clinical features of the disease were studied. In two cases, the cause of the migration of bile calculi into the intestine was cholecystoduodenal fistula and in one case – cholecystojejunal fistula in combination with cholecystocholedochal fistula. A detailed analysis revealed variability in the clinical course of this pathology. The informativity of the diagnostic methods was studied. In all cases, different surgical treatment was required. The intraoperative complication that arose in one of the cases necessitated additional operative intervention.

G-Protein Coupled Receptor (GPCR), Class C, Group 5, Member A (GPRC5A) has been implicated in several malignancies. The underlying mechanisms, however, remain poorly understood. Using a panel of human cell lines, we demonstrate that CRISPR/Cas9-mediated knockout and RNAi-mediated depletion of GPRC5A impairs cell adhesion to integrin substrates: collagens I and IV, fibronectin, as well as to extracellular matrix proteins derived from the Engelbreth-Holm-Swarm (EHS) mouse sarcoma (Matrigel). Consistent with the phenotype, knock-out of GPRC5A correlated with a reduced integrin beta 1 (ITGB1) protein expression, impaired phosphorylation of the focal adhesion kinase (FAK), and lower activity of small GTPases RhoA and Rac1. Furthermore, we provide the first evidence for a direct interaction between GPRC5A and a receptor tyrosine kinase EphA2, an upstream regulator of FAK, although its contribution to the observed adhesion phenotype is unclear. Our findings reveal an unprecedented role for GPRC5A in regulation of the ITGB1-mediated cell adhesion and it's downstream signaling, thus indicating a potential novel role for GPRC5A in human epithelial cancers.

A linear two-dimensional boundary value problem, that describes steady-state surface and internal waves due to the forward motion of a body in a fluid consisting of two superposed layers with different densities, is considered. The body is fully submerged and intersects the interface between the two layers. Two well-posed formulations of the problem are proposed in which, along with the Laplace equation, boundary conditions, coupling conditions on the interface, and conditions at infinity, a pair of supplementary conditions are imposed at the points where the body contour intersects the interface. In one of the well-posed formulations (where the differences between the horizontal momentum components are given at the intersection points), the existence of the unique solution is proved for all values of the parameters except for a certain (possibly empty) nowhere dense set of values.

Under discussion are the results of testing the sorption properties of new filtering materials like CARBOVER (Russian: КАРБОВЕР), which is plasma combination of carbon composite with exfoliated vermiculite surface, and plasma-stimulated carbon material (Russian: ПСУМ), derived from the nanotechnology suggested. The evaluation of sorption properties of the filtering materials has been done for main natural radionuclides of sanitary importance contained in fresh water (226Ra, 210Pb, 210Po, 238U). According to the data of predesigned experiments, the nanotechnology used has been proved effective. The nanotechnology enables plasma stimulation of carbon materials to create sorbents, which are composites with prescribed properties. The key point of the given technology is decomposition of hydrocarbons caused by low-temperature plasma. In the function of low-temperature plasma arc-vacuum discharge plasma is used, with the discharge burning in vapors of graphite cathode. The sorption processes of natural radionuclide 226Ra by these filtering materials are examined in most details. Plasma-stimulated carbon material (in pure form) demonstrates high sorption performance in case of natural radionuclide 226Ra in water. After filtration of distilled water with 226Ra dispersed in it, the specific radioactivity in water has become at least 100 times less. This equally refers to the natural radionuclides 224Ra and 228Ra, which are chemically identical to the 226Ra. The suggested composite filtering material CARBOVER, based on exfoliated vermiculite from the composition of plasma-stimulated carbon material, also has high sorption qualities against the mentioned radionuclides most common in ground waters (with reduction of their specific radioactivity in filtered water of up to 80 %). As well under consideration are topical issues of obtaining biotropic water, which has the ability to strengthen the interfacing between biopolymer macromolecules and water clusters. A number of scientific and technical solutions discussed in the paper have patent protection.

The article outlines the materials of the researches, aimed at studying the loads, acting on the drill bit of cutting and shearing principle in the process of drilling rock sample at the stand. A placing scheme of the measuring equipment (strain gauges), based on the principle of independence of measurement of each of the parameters affecting the drill bit, is developed. As a result of the research is considered the possibility to calculate the point of impact and main force moment of system of forces, influencing the drill bit from the rock.

In the article the methods of well workover realization within offshore hydro technical facilities are considered. The necessity of application of a compact, small-sized surface equipment allowing well work over without tubing strings ret rievalin conditions of limited technological space on an offshore platform is justified. Herewith, standard methods of technical well workovers with the help of wire line technique do not meet the necessary requirements because of complicated horizontal and directional wells profiles. On this base, the authors suggest the well work over realization with the use of coiled tubing technology adapted to offshore hydro technical facility conditions.

To assess the reliability and durability of certain elements of the weapons of drilling cone bits and support assemblies of cutters and bits in General, it is necessary to know the magnitude of the forces acting on the elements of cutting structures of rolling cutter drill bits in the process of its interaction with the bottom. The method and results of direct measurement of these forces with the help of a special measuring device to measure the amount of force acting on each tooth of each cutter in the interaction with the indestructible face. Found that the greatest axial forces acting on the teeth of the secondary cutters. The obtained results can be used to optimize the design of drill bits.

Nuclotron-based Ion Collider fAcility (NICA) is a new accelerator collider complex under construction at the Joint Institute for Nuclear Research. The facility is aimed at providing collider experiments with heavy ions up to Gold in the center of mass energy from 4 to 11 GeV/u and an average luminosity up to 1 · 10 27 cm -2 s -1 for Au 79+ . The collisions of polarized deuterons are also foreseen. The facility includes two injector chains, a new superconducting booster synchrotron, the existing 6-AGeV superconducting synchrotron Nuclotron, and a new superconducting collider consisting of two rings, each 503 m in circumference. The booster synchrotron and the NICA collider are based on an iron-dominated “window frame”-type magnet with a hollow superconductor winding analogous to the Nuclotron magnet. The status of the serial production and test of the magnets for the booster synchrotron and the development of the full-size model magnets for the NICA collider is presented. The test results of magnets are discussed. The status of the construction of the facility for serial tests of superconducting magnets for the NICA project is described.

The aim of the study was to investigate the effects of voluntary breath-holding on brain activity and physiological functions. We hypothesised that prolonged apnoea would trigger cerebral hypoxia, resulting in a decrease of brain performance; and the apnoea’s effects would be more pronounced in breath-hold divers. Trained breath-hold divers and non-divers performed maximal dry breath-holdings. Lung volume, alveolar partial pressures of O2 and CO2, attention and anxiety levels were estimated. Heart rate, blood pressure, arterial blood oxygenation, brain tissue oxygenation, EEG, and DC potential were monitored continuously during breath-holding. There were a few significant changes in electrical brain activity caused by prolonged apnoea. Brain tissue oxygenation index and DC potential were relatively stable up to the end of the apnoea in breath-hold divers and non-divers. We also did not observe any decrease of attention level or speed of processing immediately after breath-holding. Interestingly, trained breath-hold divers had some peculiarities in EEG activity at resting state (before any breath-holding): non-spindled, sharpened alpha rhythm; slowed-down alpha with the frequency nearer to the theta band; and untypical spatial pattern of alpha activity. Our findings contradicted the primary hypothesis. Apnoea up to 5 min does not lead to notable cerebral hypoxia or a decrease of brain performance in either breath-hold divers or non-divers. It seems to be the result of the compensatory mechanisms similar to the diving response aimed at centralising blood circulation and reducing peripheral O2 uptake. Adaptive changes during apnoea are much more prominent in trained breath-hold divers.

Borobasalt systems were studied as host materials for incorporation of radioactive waste from pyroelectrochemical technology. For all the examined compositions, the leach rates are of the order of 10–7 g cm–2 day–1, which is quite acceptable for radionuclide immobilization. The synthesis temperature ensuring formation of homogeneous glasses is about 1250°С for all the examined compositions. The host material is capable to incorporate up to 40 wt % phosphate wastes, which seems quite sufficient from the viewpoint of technology. The system is only weakly sensitive to variations of the boric anhydride content.

Jerusalem artichoke (JA) tubers have recently attracted interest as a functional ingredient in food products with enhanced nutritional characteristics. Dried powder of JA tubers was prepared using a developed vacuum vibromixing apparatus to prevent degradation of thermolabile substances. The critical principle of technological calculations for vibrating apparatuses is to determine the power consumption of the load circulation, depending on dynamic parameters. The paper aims to examine the effect of changes in the amplitude and frequency of apparatus vibration on the power consumption while drying the JA tubers. The results obtained experimentally in the laboratory vibromixing dryer (282 mm in diameter, 186 mm in length) show that with an increase in the amplitude, as well as the frequency of the vibration, the time of mass heating to the drying temperature and total drying time decreased. It was found that the maximum useful power is transmitted to the load at optimal vibration modes: 1.44 mm amplitude and 50 Hz frequency. Thus, under optimal dynamic parameters, the approximate time of the drying process can be determined at the moment when power value is fixed. The current results allow automatically controlling the termination of JA powder drying through power change.

The increase in engine power and the speed of movement of the machine-tractor unit leads to an increase in the amplitude and frequency of oscillations of the hook force. At the same time, the magnitude of these effects depends on fluctuations in the hook load, the nature of the work process, the dynamics of operating modes and the frequency properties of the transmission. Reducing the nature of transient dynamic loads can be achieved by using elastic connections in the tractor structure. The issues of a rational combination of increased operating power of the engine with a simultaneous decrease in dynamic loads in the transmission exacerbate the problem of choosing rational modes of operation of the machine-tractor unit. Uneven hook load causes fluctuations in the engine crankshaft rotation speed, an increase in the load on the transmission parts and, consequently, a decrease in power and an increase in engine fuel consumption. Therefore, to protect the transmission from vibrations that occur in the engine-transmission system, special damping devices are used. A characteristic feature of the device, which is the possibility of using elastic - damping elements, allowing to reduce the frequency of natural vibrations of the transmission.

The evolution of sedimentary rock formation of a highly organized level (paragenetic rock associations) is more complex than that of a poorly organized level (rocks). Subjacent rock associations are established for the entire geological evolution of the Earth: they varied in time and were obsolescent or, in contrast, nascent and momentary. A certain cyclicity of evolution is identified along with directed changes.

For the first time, the possibility of deactivation of a metal surface by the dry method by means of treatment with cathode spots of a vacuum-arc discharge is shown. A high deactivation coefficient is obtained by squeezing the liquid phase of the metal from the cathode spot with a high pressure created by the plasma flow at the base of the cathode jet. Some principles of controlling the movement of cathode spots of a vacuum arc on the surface are shown.

Electrical machines on the base of high temperature superconductors (HTS) could provide high specific (kW/kg) and volumetric (kW/m3) power. The most promising of them are fully HTS machines. Significant number of parameters and factors which have an impact on HTS windings make analytical analysis of the machine very complex. In this paper description of the prototype of fully HTS electrical machine is provided. Manufactured prototype was tested, experimental and calculation results were compared. In particular, open circuit performance is in good correlation with theoretical conclusions. Besides, results of experimental research of 15 HTS coils are provided. Some design features of the prototype are described.

The article describes the experience of JSC "Compressor" in creation of advanced compressor equipment employing reciprocating compressors for the oil and gas sector. Issues of 3D modelling, calculation, survey and improvement of reciprocating compressor valves with account of gas real properties and actual operation conditions are considered by the example of a multi-stage reciprocating compressor with the use of computer gas dynamics methods. Efficient and reliable operation of reciprocating compressors within the wide range of operating conditions is one of the most important problems in design, production, and operation of the compressor equipment. Reciprocating compressors used as part of mobile gas filling tanks are intended for compression of natural gas up to the final pressure of 20-25 MPa. When such equipment is being designed, real properties of the fluid to compress have to be determined. The paper surveys theoretical influence of initial gas parameters on the working process of the compressor. Compression of both ideal and real gas has been surveyed, with its results provided herein. The mathematical model developed is briefly described, and methods to determine thermodynamic properties of methane are provided, with comparison results of calculated and tabular data available. Results of adequacy analysis of the mathematical model are given. Improvement of valves at the design stage enhances energy efficiency of the compressor operation and allows avoiding such negative phenomenon as flutter at high-pressure stages. Efficient stripping and dehydration of high-pressure natural gas downstream of the compressor with the use of PSA modified technology and batch heating of recycle gas is considered.