Home – Home – Jornals – Journal of Applied Mechanics and Technical Physics 2018 number 5

We present results of geochronological (⁴⁰Ar-³⁹Ar, U-Pb SHRIMP-II, and LA-ICP-MS) and geochemical studies of alkaline rocks of the Amalat, Sirikta, Tsipa, Pravyi Uligli, and Verkhnii Uligli massifs in the Vitim plateau (western Transbaikalia). The formation of the alkaline rocks and the accompanying albitization are dated at 261-242 Ma. The isotope inhomogeneity (ε_Nd( T ) = +8.4 to -1.7) of the alkaline rocks indicates the heterogeneous composition of the source of their material having a depleted component, an enriched juvenile metasomatic fluid, and a crustal substrate.

The Mukodek gold field is located in the Yana zone of the Baikal-Muya fold belt (northern Transbaikalia). Its orebodies are gold-bearing metasomatites confined to the fault of NE strike. It is shown that pre-ore faults played a crucial role in the spatial localization of the orebodies, as they favored the concentration of ore-bearing fluids. Results of geological and structural studies, along with available geochronological data (⁴⁰Ar-³⁹Ar dates for micas in gold-bearing pyrite), testify to ore-forming processes in the ore field during two Late Paleozoic stages. Early gold-bearing metasomatites of sericite-chlorite-albite-ankerite-quartz composition formed at 320 Ma, and late gold-bearing vein metasomatites of ankerite(calcite)-quartz composition originated at 285 Ma. A Pb-Pb isotope study of gold mineralization has shown that ore lead was supplied into the mineral-forming system mainly from a mantle source, most likely, regional Neoproterozoic igneous rocks. According to Sm-Nd isotope data, these rocks formed with the participation of a material of mantle genesis.

Bezymianny is an active andesitic volcano of the Klyuchevskaya group, and its eruptive products are xenolith- and enclave-bearing basaltic andesites and dacites. Here we report the first occurrence of clinopyroxene-plagioclase high-potassium basaltic trachyandesite xenoliths (51.84-53.00 wt.% SiO2, 0.95-1.95 wt.% K2O) crystallized in the temperature range 1120-840 °C in products of modern eruptions (2007, 2011, 2012). Basaltic trachyandesite differ systematically in petrologic and geochemical characteristics from all previously studied rocks from the Bezymianny Volcano. They correspond to the clinopyroxene-plagioclase porphyry rocks from the foot of the Tolbachik volcanoes.

Lineament analysis is applied to map the pattern of the Obruchev fault system in the Buguldeika Village area, where several fault zones (Olkhon, Primorye, Prikhrebtovyi, Buguldeika, and Kurtun) make up a junction. As inferred from the predominant directions of genetically related lineaments, the Olkhon, Primorye, and Prikhrebtovyi faults originated under NW-SE extension and compression. The extension and compression settings within these zones are reconstructed by analysis of lineaments that have prominent and poor geomorphic expression, respectively. However, the pattern of lineaments well expressed in the surface topography within a weakly deformed block corresponds to reverse slip, while that of poorly pronounced lineaments corresponds to left-lateral strike slip. The study confirms the idea that the latest extension (rifting) stage in the Baikal region reactivated fault zones but did not deform blocks. The blocks store record of residual deformation produced by previous settings of regional compression and shear. The obtained results agree with earlier tectonophysical analysis of faults and fractures in the area and prove the applicability of the suggested approach to map the fault patterns and reconstruct their respective stress settings in areas that underwent multiple deformation events of different ages.

Paleogeographic reconstructions for the Samarovo, Taz, Murukta, and Sartan glaciations reveal the formation conditions of proglacial lakes dammed by ice in intermontane depressions and valleys of large rivers in eastern Transbaikalia. Middle-Late Pleistocene climate change is reconstructed using spore-pollen spectra from Pleistocene sediments in northern Transbaikalia. The age and lifetime of proglacial lakes are constrained by radiocarbon, thermoluminescence, and varve chronology of their bottom sediments in the periglacial zone. The lake levels remain recorded in sediments produced by deposition and erosion along the former lake shores, as well as in morphology and lithology variations of terminal moraines. A large proglacial lake, with a maximum level of 1020 m, occupied vast areas in Transbaikalia and its surroundings during the Samarovo glaciation. After the glaciers degraded, the Amur River system expanded into the area of closed lake basins in the southeastern Baikal region, including North China and Mongolia. The obtained results have implications for the Middle-Late Pleistocene history of lake deposition.

Secondary micas after smectite, including mix illite-smectite phases, can form in sediments by three mechanisms, each being specific to particular environments. As the process develops, the newly formed phases undergo structure ordering. Two mechanisms involve transformation of 2:1 mixed-layer structures, and the third is the growth of screw dislocations, with formation of ordered mix phases having a Reichweite parameter of R = 1 or R = 2. We propose methods for identifying such phases when they are present in small amounts or when their XRD patterns lack well-pronounced superperiodic reflections, as well as mathematical formalism for illitization modeling. The theoretical issues are illustrated with field examples, and the illitization mechanisms are discussed in terms of their possible practical applications.

A technique akin to Galton’s composite portraiture is suggested for creating a generalized image of a stratigraphic unit based on well log data from a group of well sections. The procedure begins with superimposing stratigraphically equivalent section points according to pairwise correlation models followed by weighted summation of similar logs. The superimposition highlights persistent common features of the sections while their minor individual details become suppressed. A generalized model of the Bazhenov Formation in the Salym area has been constructed from gamma-ray, apparent resistivity, and self-potential logs. Radioactivity and resistivity anomalies, which are often used as constraints on the Bazhenov Formation boundaries, show a significant spatial discrepancy. According to the correlation, the formation volume in each well depends on the depth interval corresponding to the hypostratotype. The results were used to map the Bazhenov Formation thickness and its standard deviation, as well as average values of different logs.

This study presents data on concentrations of n -alkylbenzenes, n -alkylnaphthalenes, phytanylnaphthalene, and methylphytanylnaphthalene in representative crude oils of Tatarstan. The results of the study reveal the elevated concentrations of C19, C21, and C23 homologues of n -alkylbenzenes and n -alkylnaphthalenes, which can be considered biomarkers. The proposed procedure for comprehensive quantification of this group of biomarkers can be used as an efficient tool to study oils from the major petroleum basins of Russia. Based on the results of the study, four genetic groups of oils in Tatarstan have been distinguished: (1) oils from the north and northwest (Bir saddle, Lower Kama system of linear faults, and Saraily saddle), (2) oils from Devonian terrigenous reservoirs within the South Tatar arch and Melekes depression, (3) oils from Carboniferous reservoirs, and (4) oils from Devonian carbonate reservoirs. All these oils belong to the same genetic macrotype. Based on the results of this study, the sedimentary sections of the Melekes depression cannot be regarded as potential source rocks. It is assumed that oil has migrated to the northern part of the region from the north or east. Some of the possible migration routes for oils from the remaining part of Tatarstan are from the southeast and/or south.

A zone with high remanent magnetization and magnetic susceptibility has been identified at the boundary between Lower Devonian gray- and red-colored deposits in the southwest of Ukraine (in the southwest of the East European Platform). The microparticles of native iron and nickel and iron-nickel intermetallic compounds found here might be markers of an impact event in the Lochkovian (~415 Ma). Electron microscope examination and probe microanalysis of the chemical composition, morphology, structures, and textures of specific microobjects showed that they are the product of melting of meteoritic substance and target rocks caused by an impact explosion. Explosive dispersion and deposition of microparticles on the Earth’s surface result in a rapid differentiation of their substance. The obtained data can be used as evidence of a reference impact event during the fall of an iron-stone meteorite, and a characteristic set of minerals and geochemical parameters can help to identify catastrophic events in the geologic history.

The paper presents results of paleomagnetic studies of traps of the Franz Josef Land (FJL) Archipelago. This area is considered to be part of the Barents Sea Large Igneous Province (LIP) and is usually associated with the Early Cretaceous stage of plume activity, by analogy with other manifestations of late Mesozoic trap magmatism in the High Arctic. Recent isotope-geochemical studies, however, suggest a much longer history of basaltoid magmatism in the FJL area, from Early Jurassic through Early Cretaceous, with three pulses at 190, 155, and ~125 Ma. Given a significant difference in age, paleomagnetic directions and corresponding virtual geomagnetic poles are supposed to form discrete groups near the Jurassic-Early Cretaceous paleomagnetic poles of Eastern Europe. However, the calculated virtual geomagnetic poles, on the contrary, show a single “cloud” distribution, with its center being shifted to the Early Cretaceous paleomagnetic poles of Siberia. The performed analysis demonstrates that the significant variance is caused mostly by the high-latitude position of the FJL and secular variations of the geomagnetic field during the formation of the traps. Products of the Early Cretaceous magmatism evidently prevail in the data sample. The coincidence of the average paleomagnetic pole of the FJL traps with the Early Cretaceous (145-125 Ma) interval of the apparent polar wander path of Siberia rather than Eastern Europe confirms the hypothesis of the Mesozoic strike-slip activity within the Eurasian continent. This activity might be a natural result of the evolution of the Arctic Ocean.

We report methane concentrations in the bottom water layer and the upper layer of bottom sediments and the results of acoustic explorations of methane seeps on the shelf bordering the continental slope of the Sea of Japan region, in which electromagnetic Schumann’s resonance oscillations were earlier recorded at continental-slope water depths of 500, 1000, and 2000 m. The occurrence of Schumann’s resonances at such great depths is explained by an increase (a factor of more than 25) in the electrical resistivity of a ~2000 m thick sediment layer with the pore space largely filled with free methane. A new method is proposed for determining the depth of the sources of anomalous concentrations of methane in bottom sediments or in the bottom water layer on a deep shelf. The method is based on recording Schumann’s resonances during measurements of the natural electric field at a series of increasing depths in areas bordering the continental slope.

Results of theoretical and experimental studies obtained for an electromagnetic logging probe of new design are presented. As in the case of an induction logging probe, the magnetic dipole of the new probe produces a harmonically varying electromagnetic field, and the parameter to be measured is the electric voltage in the short receiving MN line. The theoretical studies have shown that under certain conditions, the results of measurement with this probe depend on the electrical-anisotropy coefficient and do not depend on the longitudinal and transverse electrical resistivities of the anisotropic medium. A technique for determining the electrical-anisotropy coefficient was tested on the experimental data obtained by physical modeling.

A new method of deposition of diamond films with the use of supersonic gas flows activated by a superhigh-frequency discharge is implemented for the first time. The operation principle of the proposed gas-discharge system is similar to that of a microwave electrothermal rocket engine. A mixture of hydrocarbons and hydrogen is used as a plasma-forming gas. It is demonstrated that the proposed method allows the plasma-forming gas to be used at pressures far above the upper limit of the working pressures of modern gas-discharge devices of film deposition in the plasma generated by a superhigh-frequency discharge (approximately 40000 Pa).

The influence of the molecular structure of gas flows on the characteristics of turbulent flows and the effect of the properties molecules on turbulent processes have been studied. This paper presents a review of the results of study of turbulent processes. Data on flows at the boundary of a supersonic jet and in a tube with an expanding input section, and Hagen-Poiseuille flow are given. Experimental study of Hagen-Poiseuille has shown that the molecular properties of the medium affect the critical Reynolds number. It is shown that in comparing the critical Reynolds numbers for flows of different gases at different pressures, the determining parameter is the second virial coefficient.

This paper presents results of an experimental study, numerical calculation, and analysis within the framework of a gas-dynamic model of silicon film deposition by a gas-jet plasma-chemical method. A numerical model of a flow of gas mixtures, flowing out of an annular nozzle unit and flowing into a reactor, is developed, and it allows one to determine a film thickness distribution over the surface of substrates placed in the reactor and describes the experimental data obtained satisfactorily

Direct Simulation Monte Carlo method was used to study plane-parallel flow of hydrogen through an obstacle formed by a series of parallel infinite wires. Particular attention was paid to the influence of the geometric parameters of the wire obstacle, the degree of rarefaction and the velocity of the flow on the degree of hydrogen dissociation due to heterogeneous reactions on the wire surface.

Expansion of near-wall films of liquids with different physical properties accompanied by high-velocity co-current gas flow from a nozzle into vacuum is studied experimentally. Local parameters of liquid films inside the nozzle are measured. Gas-droplet flow structure behind the nozzle exit cross-section is examined. Limiting temperatures of liquid films formed on the nozzle outer surface are measured.

A possibility of using small-scale vacuum setups for experimental investigations of supersonic jets escaping from supersonic nozzles into vacuum or a rarefied space is considered. Results of studying the structure of the secondary supersonic flow formed in supersonic jets with developed condensation, which is detected for the first time, are reported. The present investigations are carried out with the use of photometry and spectrometry of jets with the use of emission excited by an electron beam; flow visualization is also performed. The results obtained in the study are analyzed; capabilities and specific features of various methods of flow registration are considered. An empirical model, which establishes the dependence between the detected secondary flow and the process of formation of large clusters in the flow, is developed and justified.

A self-consistent model for plasma polarization around an isolated dust particle with a size of 10^-6 m under the action of an external electric field is presented. It is shown that, for various intensities of the external electric fields behind the dust particle, there are self-consistent potential oscillations. The calculation results are compared with data obtained by using the known numerical approaches.

The process of folding of villin subdomain HP-35 has been studied using the method of molecular dynamics. To characterize protein conformations, two variables are introduced which correspond to the distances between fluorophores in experiments on protein folding with the Forster resonance energy. The simulation results show that the flow field of the probabilities of transitions between protein states is filled with eddies. It has been found that in contrast to the previously studied cases of hydrodynamic turbulence and turbulence in protein folding in the three-dimensional conformational space, the structure functions of the flows of various orders depend linearly on the increment in the conformational space. An explanation of this linear dependence based on the -model is proposed, and it is shown that this dependence is not due to the choice of variables for describing the folding process.

This paper describes the study of the effect of spatial inhomogeneity of surface temperature on the size of a crater forming in the case of pulsed laser ablation. It is assumed that the surface temperature is linearly dependent on laser radiation energy. Analytical expressions determining the effective radius of an evaporation region, characteristic temperatures of the surface on which evaporation occurs, and evaporation depths in the case of the Gaussian distribution of laser radiation energy are derived. It is shown that the analytical dependences obtained are in good agreement with known numerical calculation results.

The formation of a fluoropolymer coating by chemical deposition has been studied. It has been found that increasing the flow rate of the precursor gas leads to a decrease in the growth rate of the coating. The conditions deposition was analyzed, and the gas dynamic parameters of the process were estimated. It is shown that the estimates are consistent with experimental data.

A conjugated initial-boundary-value problem occurring in the movement of a binary mixture and viscous heat-conductive liquid with a common interface surface under the action of thermal-concentration forces is under consideration. A solution describing a stationary flow in layers, temperature distribution, and concentration distribution is determined. The Laplace transform method is used to obtain a nonstationary solution for the problem in images, which makes it possible to describe the evolution of the movement using the numerical inversion of images.

A Prandtl slope flow model is generalized for the case with a homogeneous stationary source of a heavy impurity that significantly changes the medium density. A stationary analytical solution for a velocity of arising flows, temperature deviations, and impurity distribution is obtained. The model describes, for example, some special features of the dynamics of a ground snowstorm above a slope surface.

Numerical study has been performed to investigate the characteristics and operating modes of an energy storage device based on a pulsed magnetohydrodynamic generator and a step-up transformer with a stored energy of 25 and 50 MJ and a secondary winding current of 250 kA at the final stage of operation. The operating parameters of such storage devices with rail launchers in the mode of rapid-fire launching of several projectiles.

The results of temperature and concentration measurements of secondary electrons in a free jet of argon, activated in an electron beam plasma, carried out using a Langmuir double electrostatic probe. A cold plasmotron prototype with a primary beam energy of 1 keV is used obtain a jet of dense cold plasma with a transverse size of approximately 80 mm and parameters with which silicon layers may be deposited with necessary characteristics in a forvacuum pressure range.

The main methods used to measure viscoelastic properties of materials in a wide range of frequencies from 10^-4 to 10⁶ Hz are reviewed. It is demonstrated that the accuracy of many experimental methods can be increased by taking into account the shape factors, which depend on the specimen type. An example of the shape factor for a cylindrical specimen is provided, which was determined numerically on the basis of a two-dimensional deformation model taking into account the specimen geometry and Poisson's ratio. The importance of the precise determination of Poisson's ratio for rubber-like and complex-structured materials is demonstrated. Requirements to such measurements and a setup satisfying these requirements are described. Two methods for measuring viscoelastic properties of living tissues (compliance and disturbance propagation velocity) are considered. Based on the developed method of measuring these parameters for materials with a fixed thickness, methods for standartization of measurements of viscoelastic characteristics of living tissues are proposed.

This paper considers the two-dimensional problem of high-velocity translational-nonequilibrium flow of a monatomic gas past a surface which was formulated in the theory of viscous hypersonic flows based on macrokinetic 13-moment Grad equations using the approximation of a two-layer thin viscous shock layer (TVSL) near non-thin bodies. A class of similarity variables is proposed that allows the kinetic problem of a TVSL to be reduced to the well-studied Navier-Stokes problem of a TVSL.

An experimental study has been performed to investigate the integral characteristics of the processes of heat and mass transfer and phase transformations during interaction of a droplet flow with the combustion front of a highly porous condensed material. The macroscopic regularities of the suppression of flaming combustion and thermal decomposition of typical forest fuel material due to the removal of heat as a result of its absorption during vaporization and convective cooling were studied. Three versions of interaction of a droplet aerosol with burning forest fuel material were considered. The time of combustion termination and the time of thermal decomposition of forest fuel materials were determined. The mechanisms of the main physicochemical processes occurring during interaction of droplet flow with the combustion front of typical forest fuel materials were established.

The onset of the Benard-Marangoni convection in a horizontal porous layer permeated by a magnetohydrodynamic fluid with a nonlinear magnetic permeability is examined. The porous layer is assumed to be governed by the Brinkman model; it is bounded by a rigid surface from below and by a non-deformable free surface from above and subjected to a non-vertical magnetic field. The critical effective Marangoni number and the critical Rayleigh number are obtained for different values of the effective Darcy number, Biot number, Chandrasekhar number, nonlinear magnetic parameter, and angle from the vertical axis for the cases of stationary convection and overstability. The related eigenvalue problem is solved by using the first-order Chebyshev polynomial method.

Level oscillations and flow in the basin of the Sea of Azov have been studied by hydrodynamic modeling using the POM Princeton Ocean Model). The hypothesis on the role of the resonance mechanism in the occurrence of extremely large amplitudes of storm surge and seiche oscillations depending on the velocity and time of motion of atmospheric fronts of the Sea of Azov has been tested. It is found that at the same wind, baric disturbances moving over the Sea of Azov induce forced oscillations, and after the disturbances cease, free oscillations with amplitudes that are 14% higher than those obtained at constant atmospheric pressure. It is shown that the movement of the atmospheric front (whose speed and time are selected under the assumption that waves with maximum amplitudes are generated) plays an important, but not decisive role in the development of the flow structure and level oscillations in the Sea of Azov.

A lumped-parameter mechanical system consisting of a chain of physically related solids, each of which has one rotational degree of freedom. It is shown that inertial-free elastic elements that connect absolutely rigid bodies of the chain can be chosen in such a way that the mechanical structure acquires the properties of the so-called absolute mechanical filter. The motion of any inertial element of this system is described by the equation of a classical harmonic oscillator with one degree of freedom. Using the system considered as an example, it is shown that there is a relationship between the models of classical and quantum mechanics. From the positions of modern classical mechanics, this lumped-parameter system confirms the Einstein's hypothesis well-known in theoretical physics and stating that a solid is a system of independent oscillators.

It is shown that the classes of exact solutions of Navier-Stokes equations with a linear and inversely proportional dependence between velocity components and some spatial variables can be expanded by adding finite perturbations, being power or trigonometric series or their sections on one of the coordinates. An example of single integration of three-dimensional equations of motion of a viscous liquid, which are reduced to an equation for the potential of two velocity components, is given.

This paper describes an experimental study of the effect of temperature on the fracture of laser welds of Mg- and Cu-containing aviation aluminum alloys. The fracture of alloys and their welds under a uniaxial loading at temperatures of -60, 20, and 85 ^oC is investigated. It is revealed that the strength and ultimate strain of welds of Cu-containing alloys decrease as temperature rises because of the formation of immobile hot spots of localized plastic shifts. Heating and cooling suppress the Portevin- Le Chatelier effect and significantly reduce the ultimate strain of a Mg-containing alloy, even though such reduction is not observed in a weld. It is shown that, at a negative temperature, the maximum limiting lengthening of the weld of a Mg-containing alloy is achieved, while the formation of secondary cracks is activated during heating.

According to the Bank of Russia (BR), Russia has been a large net creditor to the rest of the world over the last two decades. However, the rest of the world’s net debt to Russia has hardly increased in these years. This paradox is explained in the paper: net lending amounts in Russia’s official balance of payments (BoP) were largely ephemeral, and some provisions of the Russian BoP methodology were contentious. The issues related to Russia’s low foreign investment returns are also reviewed. Special attention is given to the statistical discrepancy in the Bank of Russia and Eurostat data on the direct investment flows between Russia and the EU. With the latest statistics according to the directional principle, it is demonstrated that the Bank of Russia compared with Eurostat greatly overstates the amount of the Russian foreign direct investments (FDI) in the EU and understates the scale of the Russian illegal capital flight. It is concluded that part of the funds appearing in the BR statistics as Russia’s FDI to the EU is regarded by Eurostat as irreversible capital flight from Russia. The extent of the Russian FDI round-tripping “out of Russia - to EU special purpose entities - back in Russia” is assessed.

This article is devoted to the analysis of using internal funds, bank crediting, issue of concessionary bonds for financing PPP projects in Russia. It is shown, that nowadays private financing of PPP projects deals with a systemic crisis in Russia, which is characterized both by the lack of long money and financial stability of private partners and also imperfection of the legal framework. Moreover, there is a problem with inefficient regulation of non-credit institutions investments and a lack of mechanism to attract investments into PPP projects. In this regard for the further development of PPP projects the effective measures, concerning the legislation for attraction of private investments into different PPP projects and economic actions to encourage the increase of long money in economy are required.

The article looks at the economic structure of the operational functions of an educational institution with a purpose of selecting the optimal approach to regulation and reforms in the higher education industry. The author believes that the course and program content as well as test material are natural monopolies, which implies an active government regulation. Academic administration is an oligopoly and needs only minimal monitoring from the state. Teaching itself is a monopolistically competitive market and, therefore, can be left to the market forces to achieve the optimal social outcome without any interference from the government side. The suggested approach allows simultaneously solving the problems associated with the quality of higher education and problems associated with public funding of this sector.

The paper analyzes the scale of the Siberian coals export and indicates their importing countries in the west and east (relative to the Siberia). The history of the coal export outside Siberia is outlined. The author examines the coal basins in Siberia, which coals are or can be exported. He also identified volume and areas for export from each Siberian coal basin. The development of the Russian facilities for the Siberian coal transporting is analyzed. The problems and constraints of the Siberian coals export, connected primarily with the railways and the cargo ports are investigated, as well as the possibility of overcoming them such like the reconstruction of old and construction of new railway branches, an alternative way of transporting the coal products, and the depth increasing of their processing. The outlook for the Siberian coals export is briefly presented.

The paper presents the results of the Russian labor market research in the field of personnel management. Author examined the composition and structure of this sector, identified the pain points, which the state, business, employees need to pay close attention. He compared data from different sources on the current representation of HR- specialists on the domestic market, studied the unfilled vacancies in the organizations requests, as well as obtainable information on the quality of high education on the profile of personnel management. Based of that analysis it can be concluded that the above part of labor market is characterized by significant discrepancies in indicators, in turn the educational market is overheated and does not reflect the real needs of the economy.Considering this situation, author make some recommendations on the possible directions of development of the labor market by the profession of personnel management.

The article contains reflections on the outcome of the 2018 World Cup. Against the backdrop of the excitement for the World Cup, everyday tasks of social and economic development have receded into the background. However, the time will come for summing up the results of the Mundial, the price of bread and circuses, and the image of Russia after mass euphoria.