Staff of IVM & MG SB RAS Editorial
Institute of Computational Mathematics and Mathematical Geophysics SB RAS, pr. Acad. Lavrentieva 6, Novosibirsk, 630090, Russia
October 12, 2018 marks the 90th anniversary of the birth of Academician Anatoly Semenovich Alekseev. A.S. Alekseev was a world-famous scientist, a leading expert in the field of theoretical and computational geophysics, mathematical modeling of geophysical phenomena and geoinformatics. In the world scientific community and domestic industry the name is A.S. Alekseeva marks the development and widespread introduction of new mathematical methods for solving fundamental scientific problems of a planetary scale, starting with a study of the mechanisms and prediction of earthquakes and tsunamis and ending with the study of the consequences of large celestial bodies falling to Earth (asteroids, meteorites, fragments of comets, etc.).
Numerical-statistical estimates of correlation characteristics and averaged angle near distributions of the radiation intensity field, passing throw a random medium are obtained. Comparative investigations were performed for an elementary Poisson field and for the «realistic» field of the medium optical density. The obtained estimates confirm the hypothesis about a strong dependence of investigated values on the correlation scale and the one-dimensional distribution of the medium density field.
It is known that the solution of the semilinear matrix equation X - A\overline X B = C can be reduced to solving the classical Stein equation. The normal case means that the coefficients on the left-hand side of the resulting equation are normal matrices. We propose a method for solving the original semilinear equation in the normal case that permits to almost halve the execution time for equations of order n = 3000 compared to the library function dlyap, which solves Stein equations in Matlab.
Grid-characteristic method for the numerical simulation of wave processes in continuum mechanics was initially proposed and successfully applied to periodic hexagonal computational grids. Later, it was proposed to adapt this method to non-periodic triangle and tetrahedral grids, and a broad computational experience has been gained by now. However, this approach encounters some challenges with the calculation of border and contact points when applied to various grid configurations in the areas with complex geometries. In this paper, the method limitations, which cause the problems is considered, and some improvements to overcome them are proposed.
In the Hilbert space, we consider a class of conditionally well-posed inverse problems, for which the Hölder type estimate of conditional stability on a closed convex bounded subset holds. We investigate the Ivanov quasisolution method and its finite dimensional version associated with the minimizing a multi-extremal discrepancy functional over a conditional stability set and over the finite dimensional section of this set, respectively. For these optimization problems, we prove that each their stationary point that is located not too far from the desired solution of the original inverse problem, in reality belongs to a small neighborhood of the solution. Estimates for the diameter of this neighborhood in terms of error levels in input data are also given.
V.I. Mashukov
Siberian Transport University, D. Kovalchuk st., 191, Novosibirsk, 630049
Keywords: алгоритм линейных комбинаций, теплопроводность, смешанные краевые условия, произвольная форма граничных поверхностей, стационарные задачи, сложные граничные условия, составные граничные условия, линейная комбинация решений, метод сопряжённых градиентов, метод Трефтца, algorithm of linear combinations, thermal conductivity, the mixed boundary conditions, the arbitrary form of bounding surfaces, complex constraints, static constraints problem, the linear combination of the solutions, the composite boundary conditions, the method of the combined gradients, Trefftz's method
This paper presents the computational algorithms, which make it possible to overcome some complexities with the numerical solution of the boundary-value problems of thermal conductivity when the domain of the solution has a complex form or boundary conditions differ from standard ones. Boundary contours are assumed to be broken lines (the flat case) or triangles (a 3D case). Boundary conditions and calculation results are presented as discrete functions whose values or their averaged values are given at geometric centers of boundary elements. Boundary conditions can be defined on the heat flows through boundary elements as well as on temperature, a linear temperature combination and heat flow intensity both at the boundary of the solution domain and inside it. The solution to the boundary value problem is presented in the form of a linear combination of the fundamental solutions of the Laplace equation and their partial derivatives and, also, any solutions of these equations that are regular in the solution domain, the values of functions for which can be calculated at the points of the boundary of the solution domain and at its internal points. If the solution, which participates in the linear combination, is singular, then its average value according to this boundary element is considered.
The aim of this article is to investigate the local convergence analysis of the multi-step Homeier-like approach in order to approximate the solution of nonlinear equations in Banach spaces, which fulfilled the Lipschitz as well as Hölder continuity condition. The Hölder condition is more relaxer than Lipschitz condition. Also, the existence and uniqueness theorem has been derived and found their error bounds. Numerical examples are available to appear the importance of theoretical discussions.
V.M. Sveshnikov1,2, A.O. Savchenko1, A.V. Petukhov1 1Institute of Computational Mathematics and Mathematical Geophysics SB RAS, pr. Acad. Lavrentieva 6, Novosibirsk, 630090, Russia 2Novosibirsk State University, Pirogova st., 2, Novosibirsk, 630090, Russia
Keywords: внешние краевые задачи, декомпозиция расчетной области, вычисление интегралов с особенностями, итерационные методы в подпространствах Крылова, exterior boundary value problems, non-overlapping decomposition, computation of integrals with a singularities, iterative methods in Krylov subspaces
We propose a method for solving the three-dimensional boundary value problems for the Laplace equation in an unbounded domain. It is based on the non-overlapping decomposition of the exterior domain to the two subdomains such that the initial problem is reduced to the two subproblems, namely, the exterior and the interior boundary value problems on a sphere. To solve the exterior boundary value problem, we propose a singularity isolation method. To cross-link the solutions at the interface of subdomains (a sphere), we introduce a special operator equation that is approximated by the system of linear algebraic equations. Such a system is solved by iterative methods in the Krylov subspaces. The method is illustrated by solving the model problems confirming its operability.
The approximation neural network algorithm for solving the inverse geoelectrics problems in the class of grid (block) media models is presented. The algorithm is based on constructing an approximate inverse operator using neural networks and makes it possible to formally obtain solutions of the inverse geoelectrics problem with the total number of desired parameters of the medium ~ n 103. The correctness of the problem of constructing the neural network inverse operators is considered. A posteriori estimates of the degree of ambiguity of the inverse problem solutions are calculated. The operation of the algorithm is illustrated by examples of the 2D, the 3D inversions of synthesized and field geoelectric data, obtained by the MTS method.
The
thermal conductivity and the thermal diffusivity coefficients of samarium have
been measured by the laser flash method in the temperature interval of
293 – 1773 K in solid and liquid states including the regions of
phase transitions. The measurement errors of the heat transfer coefficients
were ±(3–6)%.
The approximation equations and
the tables of reference data for the temperature dependence of properties
have been obtained. The obtained results have been compared with the available
literature data
We propose an
improvement of an analytical approach presented previously for determining the
surface shape formed during laser cladding process at the goods manufacturing
in additive technologies. The approach is based on the balance of pressures on
the liquid metal surface, which occurs under the gravity and surface tension. A
method generalization is proposed for the case of a curvilinear shape of a
substrate, which allows determining the surface geometry at arbitrary contact
angles for single beads, vertical walls, and coatings formed by overlapping
beads. The verification of the considered approach was carried out for
laser cladding problems with the use of experimental data obtained by
other authors.
R.Kh. Bolotnova1 and E.F. Gainullina1,2 1Mavlyutov Institute of Mechanics UFRC RAS, Ufa, Russia 2Ufa State Aviation Technical University, Ufa, Russia
E-mail: bolotnova@anrb.ru
Keywords: simulation, OpenFOAM package, thin nozzle, steam outflow, supercritical state
Pages: 751–757
The
process of hollow jet formation during steam outflow through a thin nozzle was
studied; the water steam was initially at high pressure and in the
supercritical state. The numerical solution for this problem was obtained with
the sonicFoam solver library from the open-source CFD software package OpenFOAM
in 2D axisymmetric formulation. The reliability of results is estimated by
comparing two approaches for simulation of the dynamics of unloading wave
propagating in the high-pressure nozzle using the OpenFOAM package with Peng-Robinson equation of state and numerical solution
of a similar problem by method of through computation in the case of 1D planar
approximation for perfect gas equation of state.
N.M. Bozhanova1, I.T. Panov2, V.K. Manolov1, A.N. Cherepanov3, and R.L. Lazarova1 1Institute of Metal Science, Equipment and Technologies, Bulgarian Academy of Sciences, Sofia, Bulgaria 2Affiliation of Sofia Technical University, Plovdiv, Bulgaria 3Khristianovich Institute of Theoretical and Applied Mechanics SB RAS, Novosibirsk, Russia
E-mail: ancher@itam.nsc.ru
Keywords: corrosion, protective anode, negative potential, electrochemical protection, aluminum alloy, nano-modification
Pages: 759–764
Experimental
study was performed on the influence of nanosized refractory nanopowders on the
structure and electrochemical characteristics of aluminum alloy AlZn4 used as
protective anode. It was found that modification of alloy AlZn4 with nanopowder
of aluminum nitride or diamond induces refining of alloy structure by the
factor of 1.5, increases the anode strength and its protective negative
potential. Those factors have practical value for higher efficiency of
protection from corrosion in water-contacting vessels.
Numerical
simulation of thermal state was performed for semitransparent medium; the
thermal state is formed under impact of incident radiation and convective heat
transfer to the ambient medium. The model takes into account the heat transfer
to the semi-infinite opaque substrate below the layer of semitransparent
material. Computation was performed for governing parameters typical of snow
and ice coating during winter period. Solving the radiative part of problem
uses the modified average flux method. This method takes into account the
dependence of optical properties on the wavelength of incident radiation,
scattering, and reflective properties of the layer boundaries.
V.V. Salomatov1, G.V. Kuznetsov2, and S.V. Syrodoy2 1Kutateladze Institute of Thermophysics SB RAS, Novosibirsk, Russia 2National Research Tomsk Polytechnic University, Tomsk, Russia
E-mail: ssyrodoy@yandex.ru
Keywords: coal-water fuel, degree of coal metamorphism, grade of coal, ignition of coke, igni-tion of volatiles, diffusion of pyrolysis products
Pages: 773–788
The results of theoretical studies of the processes of ignition of water-coal fuel droplets based on brown coal, semi-anthracite, anthracite, long-flame and fat coal under the conditions corresponding to the combustion spaces of typical modern boilers are presented. The influence of the degree of metamorphism (structural-molecular transformation of organic matter of coal) and concentration of the organic component of the base fuel (coal) on the conditions of ignition of water-coal fuel particles is analyzed. It is determined that the type and grade of coal have a significant impact on the dynamics of fuel ignition. It was shown that in the case of ignition of coal-water fuel made of mineral coal, the ignition of particles based on semi-anthracite and anthracite is the fastest (by 20%), and ignition of coal-water fuels of fat coal is the slowest. The latter is explained by the lower heat capacity and thermal effect of pyrolysis of this fuel, as well as the relatively high heat conductivity of anthracite coal as compared to fat coal. It has been determined that drops of coal-water fuel made of brown coal ignite substantially (2 times) faster than drops prepared from coal of coal-water particles. This is due to the high content of volatiles in the composition of brown coal.
Comparative analysis of the main characteristics of the process: ignition delay times (tign ) obtained by mathematical modeling and experiments showed a satisfactory agreement between the theoretical and experimental values of tign .
The velocity fields
obtained by PIV (Particle Image Velocimetry) in supersonic flows are not
sufficient to determine the integral characteristics of the flow. Additional
data, for example, on pressure can be obtained from the solution of the Navier-Stokes equations. For incompressible flows, the
solution of these equations is not too complicated. However, for supersonic
flows, the need to take into account the flow density and the increasing number
of experimental errors make it more difficult.
This paper proposes a new method for calculating density and pressure
from PIV data on the basis of the continuity equation. This method is robust
and easy to implement for compressible flows.
A short review is given on the particular phenomena of abstracting lattice oxygen by conventional hydrocarbon under mechanical stressing. The process can be regarded as a reduction process similar to a traditional hydrometallurgy. However, the mechanochemical process can be regarded as a tool for introduc-ing oxygen vacancies and enables to acquire suboxides or the oxide with lower oxidation number, when we deal with transition metal oxides. Case studies on SiO2 and V2O5, based on our recent experimental studies.
C. WANG1,2, Q. LIANG2, G. LIU1, M. CHEN1, and H. GAO1 1School of Material Science and Engineering, Dalian Jiaotong University, Dalian, China E-mail: wangchunfeng821@163.com 2Guangxi Yuchai Machinery Co., Ltd., Yulin, China
Keywords: modified SiC particles, fine grain strengthening, gray cast iron, tensile strength
Pages: 465-470
Several studies have shown that the mechanical properties, corrosion resistance, and wear resistance of cast alloys, such as gray iron, ductile iron, aluminum bronze, and stainless steel, can be considerably enhanced by adding modified micro and nano SiC particles (SiCp). However, the distribution of SiCp in the melt can still be improved. Investigating the morphology and interaction mechanism of these particles is insufficient. In this study, the distribution and mechanism of HT250 in melt are studied by adding different amounts of modified SiCp. Results show that the microstructure of gray cast iron can be refined, and its tensile strength can be improved by the addition of modified SiCp. The improvement increases with the increase in the amount of added SiCp. Kinetic analysis shows that the mismatch between SiC and graphite is 8.1, and the size of SiC decreases after its addition to the melt. SiC satisfies the nuclei size condition of graphite and austenite precipitation and serves as the pinning particle that hinders the movement of the grain boundary. The addition of SiC to gray cast iron is crucial in fine grain strengthening because of these behavioral characteristics.
C. WANG1,2, X.-R. MO1, C. WANG1, and H. GAO1 1School of Materials Science and Engineering, Dalian Jiaotong University, Dalian, China
E-mail: wangchen19870913@126.com 2Liaoning Geology Engineering Vocational College, Dandong, China
Keywords: mechanical activation, phosphorite powder, leaching degree, kinetics
Pages: 471-475
A high-energy planetary mill was used to conduct the mechanochemical activation treatment of phosphorite powders and increase the phosphate leaching rate. Laser particle analysis, X-ray diffractometry, and scanning electron microscopy were applied to study the influence of this treatment on the phosphate leaching rate. The kinetics and mechanisms of the mechanical activation of phosphorite powders was preliminarily analyzed on the basis of a solid-phase reaction kinetic model. Results show that the mechanochemical activation of phosphorite powders can effectively reduce the degree of crystallinity and improve their reactivity. The phosphate leaching rate can reach as high as 56.19 % after phosphate is activated eight times at a rotational speed of 1000 r/min of the planetary mill. The solid-phase reaction of activated phosphorite includes two processes: diffusion and interfacial reaction. The kinetic constant continuously changes with the reaction.
X. LONG1,2, Q. LIANG2, A. POLITOV3, Y. LI1, M. CHEN1, and H. GAO1
a:2:{s:4:"TEXT";s:408:"1School of Material Science and Engineering, Dalian Jiaotong University, Dalian, China
2Guangxi Yuchai Machinery Parts Manufacturing Co., Ltd., Guangxi, China
3Institute of Solid State Chemistry and Mechanochemistry, Siberian Вranch, Russian Academy of Sciences, Novosibirsk, Russia";s:4:"TYPE";s:4:"html";}
Keywords: Dioscorea saponin, mechanical activation, thermodynamic, kinetics
Pages: 477-481
Dioscorea saponin isolated from the rhizome of Dioscorea nipponica Makino was investigated by performing grain size, SEM, XRD, FTIR and TG-DSC analysis. The sizes of D50 for the Dioscorea saponin sample activated by AGO mill decreased to as low as 10.03 μm. According to SEM and XRD, the granularity and structures of Dioscorea saponin samples with and without mechanical activation significantly differed, and the crystalline of Dioscorea saponin was significantly converted into amorphous state after mechanical activation. On the basis of TG-DSC analysis, two endothermic peak of Dioscorea saponin after mechanical activation moved back 15 and 35 °C respectively, and it had 99 % weightlessness ahead of 100 °C due to the accelerated decomposition. According to thermal analysis kinetics, the average thermal decomposition activation energy of Dioscorea saponin after mechanical activation was increased 13.45 kJ/mol, and the dynamic mechanism function of Dioscorea saponin was f(α) = 6(1 - α)2/3[1 - (1 - α)1/3]1/3, and this was regarded the mechanism of three-dimensional diffusion. With mechanical activation, the dynamic mechanism function was f(α) = 4(1 - α)1/2[1 - (1 - α)1/2]1/2, and this was regarded the mechanism of two-dimensional diffusion. The result of transformation from three-dimensional to two-dimensional diffusion mechanism was consistent with XRD analytical result of transformation from original ordered crystalline structure to amorphous state after mechanical activation. None of the functional groups of the mechanically activated Dioscorea saponin disappeared, and no new functional groups appeared, which indicate that mechanical activation does not induce a chemical transformation of Dioscorea saponin.
a:2:{s:4:"TEXT";s:199:"T. F. GRIGOR’EVA1, S. A. KOVALEVA2, P. A. VITYAZ2, V. I. ZHORNIK2, T. YU. KISELEVA3, S. V. VOSMERIKOV1, and N. Z. LYAKHOV1";s:4:"TYPE";s:4:"html";} 1Institute of Solid State Chemistry and Mechanochemistry, Siberian Branch, Russian Academy of Sciences, Novosibirsk, Russia
E-mail: grig@solid.nsc.ru 2Joint Institute of Mechanical Engineering, National Academy of Sciences of Belarus, Minsk, Belarus
E-mail: sveta_kovaleva@tut.by 3Lomonosov Moscow State University, Moscow, Russia
Keywords: mechanochemical reactions, powder metallurgy, abrasives, silicon carbide, boron carbide, titanium carbide, magnetic abrasive materials
Pages: 483-487
Operating characteristics of mechanochemically synthesized powder materials for magnetic abrasive treatment depend on microstructure and elemental distribution within composite particles. X-ray diffraction, high-resolution electron microscopy, and Mössbauer spectroscopy were used to explore Fe/SiC, Fe/B4C, and Fe/TiC mechanocomposites that can be applied as magnetic abrasive working media. Synthesis of iron/abrasive mechanocomposites was carried out in an AGO-2 high-energy planetary ball mill with water cooling under argon. Silicon carbide inclusions of 0.6–5.0 µm size range are homogeneously distributed in composite Fe/SiC particles of 8–110 µm. There is the inter-phase interaction of iron and B4C abrasive in the Fe–B4C system upon mechanical activation.
Fe/TiC composites were produced by the two-step mechanochemical synthesis. Fine
titanium carbide powders generated in the
first step of synthesis during activation with the formation of the high energy
titanium–carbon system are mechanochemically fused together with iron
powder particles in the second stage. Synthesis of TiC is completed within 4 min of mechanical activation with formation
of particles of 0.1–0.5 µm size. The Fe/TiC composites are formed within
2 min of mechanical activation of titanium (IV) carbide with iron.
a:2:{s:4:"TEXT";s:204:"S. A. KOVALEVA1, V. I. ZHORNIK1, T. F. GRIGOR’EVA2, M. A. BELOTSERKOVSKII1, P. A. VITYAZ1, A. D. DUBINCHUK3, and N. Z. LYAKHOV2";s:4:"TYPE";s:4:"html";} 1United Institute of Mechanical Engineering, National Academy of Sciences of Belarus, Minsk, Belarus
E-mail: sveta_kovaleva@tut.by 2Institute of Solid State Chemistry and Mechanochemistry, Siberian Branch, Russian Academy of Sciences, Novosibirsk, Russia 3Belarusian State University, Minsk, Belarus
Keywords: mechanical activation, mechanocomposites, boron carbide, tungsten, ultra-high-molecular-weight polyethylene, FT-IR spectroscopy
Pages: 489-494
Structural transformations of a powder mixture of ultra-high-molecular-weight polyethylene and nanostructured B4C/W composite were explored by X-ray diffraction, scanning electron microscopy, and FT-IR spectroscopy. The mixture was treated in a high-energy planetary ball mill. It was demonstrated that scaly-shaped polymer composite particles of a 160–400 µm size were generated during mechanical activation. Boron carbide and tungsten particles sized 1–5 and 0.1–0.2 µm, respectively, were evenly distributed therein. The interaction between mixture components during intensive mechanical deformations is accompanied by the crosslinking and decomposition of polymer molecules. As a consequence, there are a decrease in the molecular mass of the polymer and the lack of its extensive oxidative decomposition in this case.
E. A. DENISOVA1,2, L. A. KUZOVNIKOVA3, S. V. KOMOGORTSEV1,2, R. S. ISKHAKOV1, I. V. NEMTSEV4, and N. A. SHEPETA2 1Kirensky Institute of Physics, Federal Research Center Krasnoyarsk Science Center, Siberian Branch, Russian Academy of Sciences, Krasnoyarsk, Russia E-mail: len-den@iph.krasn.ru 2Siberian Federal University, Krasnoyarsk, Russia 3Krasnoyarsk Institute of Railways Transport, Krasnoyarsk, Russia 4Federal Research Center Krasnoyarsk Science Center, Siberian Branch, Russian Academy of Sciences, Krasnoyarsk, Russia
Keywords: composite particles, mechanoactivation, magnetic properties
Pages: 495-499
Changing the structure and magnetic properties of composite Al2O3/Co(P) particles was investigated in a ball mill. The initial particles were produced by electroless plating of the crystal Co95P5 shell characterized by the hexagonal dense packed structure into Al2O3 granules by chemical reduction. It was determined that the sequences of phase transitions during mechanoactivation was different for Co95P5 particles and composite Al2O3/Co95P5 species. The use of composite particles allows significantly reducing mechanoactivation time required for producing the optimum phase ratio of α/β cobalt in powders. Grain size reduction during milling causes an increase in the fraction of superparamagnetic particles reaching 12 % upon mechanical activation for 75 min, which causes a decrease in the value of saturation magnetization. Changing the magnetic properties of composite particles during ball milling correlates with structural modification of samples. The amount of the hexagonal dense packed cobalt phase in the sample determines the value of the field of local magnetic anisotropy. The latter is reduced from 8.4 to 3.8 kOe upon an increase in mechanoactivation time to 75 min.
G. R. KARAGEDOV
Institute of Solid State Chemistry and Mechanochemistry, Siberian Branch, Russian Academy of Sciences, Novosibirsk, Russia E-mail: garik@solid.nsc.ru
Keywords: aluminium hydroxide, alpha-alumina, nanopowder, synthesis, sintering
Pages: 501-506
Mechanical activation of gibbsite containing 0.5–5 vol. % of alumina nanoparticles was carried out in a planetary mill. It was demonstrated that upon 10g acceleration and above, subsequent calcination at 800 °C resulted in the complete transformation of aluminium hydroxide into a stable modification of alumina with particle size below 100 nm. Thermal treatment of activated aluminium hydroxide in wet media inhibits aggregate formation. Furthermore, powder-compacted samples are sintered till densities higher than 98 % of theoretically possible at 1350 °С.
F. M. NOSKOV and L. I. KVEGLIS
Siberian Federal University, Krasnoyarsk, Russia E-mail: fnoskov@sfu-kras.ru
Keywords: polymorphous transition, crystal clusters, fcc, hcp, and bcc lattices
Pages: 509-514
Structure formation processes were considered during polymorphic transformations in metals. A model of polymorphic transitions in metals with face-centered cubic (fcc), hexagonal closed-packed (hcp), and body-centered cubic (bcc) lattices was proposed from the standpoint of the cluster approach. The model is based on the idea of preserving the volume of octahedral cluster elements of the corresponding lattices. It was found that calculation data were in good agreement with the model representations proposed in the paper.
YU. A. CHUMAKOV1 and A. G. KNYAZEVA1,2 1Institute of Physics of Strength and Materials Science, Siberian Branch, Russian Academy of Sciences, Tomsk, Russia E-mail: chya@ispms.tsc.ru 2National research Tomsk Polytechnic University, Tomsk, Russia
Keywords: mechanical activation, composites synthesis, solid-phase combustion, modelling
Pages: 515-523
A model of synthesis was proposed and theoretically investigated via combustion of a composite in mechanically activated Ti–C, Ti–B, and Ti–Si powder mixtures. The effect of mechanical activation on synthesis modes was explored by introducing special activation parameter. As demonstrated by calculations, with its increase, the maximum temperature in the reaction wave is decreased during the reaction; combustion concentration limits are expanded and the propagation velocity of the reaction front is increased.
S. G. MAMYLOV and D. V. ORLOV
Institute of Solid State Chemistry and Mechanochemistry, Siberian Branch, Russian Academy of Sciences, Novosibirsk, Russia
E-mail: mamylov@solid.nsc.ru
Keywords: glycoside bond, quercetin, glucose, IR spectrum, quantum chemical modeling, mechanochemical activation
Pages: 525-529
Reactions of quercetin and carbohydrates produce different compounds. IR spectroscopy detects glycoside bond formation. The reaction for the synthesis of glycosides in solution is labour-consuming and costly in time and resources. Nevertheless, reaction progress becomes easier in the solid phase. An opportunity to generate glycosides during mechanochemical activation of a mixture of solid quercetin and glucose significantly simplifies and cheapens some technologies in the food industry and feed preparation. IR spectra of quercetin, glucose, and isoquercitrin were acquired by quantum chemical modeling (Gaussian 09) in the initial step. They were then obtained experimentally for reagents and possible reaction products (Tensor 27, Bruker). New absorption bands were detected in IR spectra. Absorption bands in the 950–1050 cm–1 region are typical for the formation of a glycoside bond from carbohydrate and aglycone and may be assigned to the natural glycoside isoquercitrin.
P. YU. TYAPKIN1, S. A. PETROV1, A. P. CHERNYSHEV1,2, K. B. GERASIMOV1, and N. F. UVAROV1,2,3 1Institute of Solid State Chemistry and Mechanochemistry, Siberian Branch, Russian Academy of Sciences, Novosibirsk, Russia E-mail: p.yu.tyapkin@gmail.com 2Novosibirsk State Technical University, Novosibirsk, Russia 3Novosibirsk State University, Novosibirsk, Russia
Keywords: thermolysis, SBA-15, iron (III) oxalate, iron oxides, synchronous thermal analysis, Mossbauer spectroscopy
Pages: 531-535
Processes of thermal decomposition of iron (III) oxalate placed into pores of structured mesoporous silica (SBA-15) were investigated. Synchronous thermal analysis of samples was carried out in inert (argon) and oxidizing (a mixture of argon and 20 % oxygen) media. The composition of gas thermolysis products was detected mass spectrometrically. The initial salt and solid-phase products of its decomposition were characterised by X-ray phase analysis and Mössbauer spectroscopy. It is well known that the process of thermolysis of iron (III) oxalate under inert atmosphere conditions proceeds in two stages: intermediate decomposition to anhydrous iron (II) oxalate and then the final one to Fe3O4 and α-Fe at 150–180 and 310–400 °C, respectively. Oxidative thermolysis occurs in a single step. In other words, iron (III) oxide is formed from the initial salt that is later crystallised into hematite phase. However, this step is complex. Instantaneous oxidation of anhydrous iron (II) oxalate formed as an intermediate explains high exothermicity of the process. It was found that the temperature of the initial decomposition step was reduced from 150 to 80 °C for a precursor placed into SBA-15 silica matrix pores in both oxidative and inert media. Herewith, the finishing temperature of the step for oxidative thermolysis is increased almost by 100 °C. Gas evolution spikes and extremes in the calorimetric curve of the second step of decomposition in argon are reduced by 30–40 °C. An increase in the reactivity of fine particles and the amorphous state of iron (III) oxalate explained a reduction in gas evolution peaks. In order to describe the behaviour of the precursor, upon oxidative thermolysis likely reactions determining the process were suggested.
a:2:{s:4:"TEXT";s:148:"T. A. UDALOVA1,2, T. F. GRIGOR’EVA1, E. T. DEVYATKINA1, S. V. VOSMERIKOV1, and N. Z. LYAKHOV1";s:4:"TYPE";s:4:"html";} 1Institute of Solid State Chemistry and Mechanochemistry, Siberian Branch, Russian Academy of Sciences, Novosibirsk, Russia E-mail: udalova@solid.nsc.ru 2Novosibirsk State Technical University, Novosibirsk, Russia
Keywords: mechanochemical reduction, highly dispersed germanium
Pages: 537-542
The effect of conditions of mechanochemical activation and stoichiometric composition on generating products of mechanochemical reduction of β-germanium dioxide with magnesium was investigated by X-ray phase analysis. It was demonstrated that differently composed mechanochemical composites might be formed at certain steps during mechanical activation of germanium dioxide. They were comprised of germanium, magnesium oxide, germanium oxide, magnesium, and the GeMg2
intermetallic compound. The process of mechanochemical reduction of germanium dioxide with magnesium comes to an end by 4 min of activation to form Ge/MgO composite. Conditions of separation of germanium powder from magnesium oxide in mechanochemical Ge/MgO composites were determined. As demonstrated by electron microscopic analysis, highly dispersed germanium powders consist of 50–100 nm primary particles similarly-shaped to spherical ones. The species are aggregated into secondary particles in 1 to 10 µm size range. The magnesium content in highly dispersed germanium powders is less than 2 %.
a:2:{s:4:"TEXT";s:119:"A. I. ANCHAROV1,2, G. N. GRACHEV3, S. V. VOSMERIKOV1, and T. F. GRIGOR’EVA1";s:4:"TYPE";s:4:"html";} 1Institute of Solid State Chemistry and Mechanochemistry, Siberian Branch, Russian Academy of Sciences, Novosibirsk, Russia E-mail: ancharov@mail.ru 2Budker Institute of Nuclear Physics, Siberian Branch, Russian Academy of Sciences, Novosibirsk, Russia 3Institute of Laser Physics, Siberian Branch, Russian Academy of Sciences, Novosibirsk, Russia
Keywords: mechanochemical synthesis, hafnium, carbon, Hf/C mechanocomposite, nanoscale and fused hafnium carbide, photon flux irradiation
Pages: 545-549
Mechanochemical preparation of nanoscale hafnium (IV) carbide was explored. It was demonstrated that the Hf/C mechanocomposite with a wide particle-size distribution was formed in the first step. Fused hafnium (IV) carbide was produced from nanoscale hafnium (IV) carbide and the hafnium/carbon mechanocomposite by treatment with high-intensity photon flux. According to research results, the mechanocomposite is more preferable and may be used as a precursor to make products of fused hafnium (IV) carbide using additive technologies.
N. V. NIFTALIYEVA1,2, E. V. SHUBNIKOVA1, and A. P. NEMUDRY1 1Institute of Solid State Chemistry and Mechanochemistry, Siberian Branch, Russian Academy of Sciences, Novosibirsk, Russia
E-mail: niftalievanatalya@gmail.com 2Novosibirsk State University, Novosibirsk, Russia
Keywords: ceramic microtubular membranes, oxygen-permeable membranes, non-stoichiometric oxides, oxygen permeability
Pages: 551-556
The effects of a series of process parameters (the composition of external coagulant and the air-gap distance) on the morphology of oxygen-permeable microtubular (MT) membranes were explored. The latter were prepared from non-stoichiometric Ba0.5Sr0.5 Co0.8 – xMoxFe0.2 O3 – δ perovskites (BSCFMх). It was demonstrated by scanning electron microscopy that the specific porous structure of MT membranes vanished when increasing the air gap between the draw hole and the bath with coagulant to 15 cm or using an ethanol solution. The oxygen permeability of MT membranes based on Ba0.5Sr0.5Co0.8 – xMoxFe0.2O3 – δ (x = 0, 0.02, 0.05, 0.10) with the optimum morphology in air and under СО2
was examined.
V. R. KHUSNUTDINOV1, A. V. LOGINOV1,2, A. I. APARNEV2, N. F. UVAROV1,2 1Institute of Solid State Chemistry and Mechanochemistry, Siberian Branch, Russian Academy of Sciences, Novosibirsk, Russia E-mail: V.Khusnutdinov@gmail.com 2Novosibirsk State Technical University, Novosibirsk, Russia
Keywords: double hydroxides MSn(OH)6 (M = Ca, Sr, Mg, and Ba), mechanochemical synthesis, alkaline earth metal salts and hydroxides, impurities of alkaline earth metal carbonates
Pages: 557-560
An opportunity for direct mechanochemical synthesis of double tin and alkaline earth metal hydroxides via two procedures was demonstrated. The latter were based on reactions of chloride (IV) pentahydrate and alkaline earth metal hydroxides or salts (in the latter case, upon simultaneous action of NaOH). It was possible to synthesize Mg/Sn layered double hydroxide using only the first procedure. Calcium, strontium, and barium compounds were synthesised by both procedures. The X-ray diffraction patterns of double hydroxides MSn(OH)6
(M = Ca, Sr, Ba) are in good agreement with structural data acquired in early research works and presented in X-ray databases. The products contain trace carbonate impurities, which is related to their presence in the initial reagents.
T. P. SHAKHTSHNEIDER1,2, S. A. MYZ1, A. S. MEDVEDEVA3, L. P. SAFRONOVA3, T. M. KONSHINA4, A. A. BURLUTSKAYA4, and G. V. GOLDOBINA4 1Institute of Solid State Chemistry and Mechanochemistry, Siberian Branch, Russian Academy of Sciences, Novosibirsk, Russia E-mail: shah@solid.nsc.ru 2Novosibirsk State University, Novosibirsk, Russia 3A. E. Favorsky Institute of Chemistry, Siberian Branch, Russian Academy of Sciences, Irkutsk, Russia 4Perm State Medical University named after Academician E.A. Wagner, Perm, Russia
Keywords: piroxicam, chitosan, mechanocomposites, mechanochemical activation, analgesic activity
Pages: 561-567
Mechanocomposites of piroxicam with different molecular weight chitosan were produced. They possessed elevated rates of release of piroxicam into a solution. Anti-inflammatory and analgesic activities of the resulting composites were explored. Piroxicam-chitosan mechanocomposites were superior analgesics compared to piroxicam.
I.N. Ozerova, V.A. Metelskaya, N.E. Gavrilova
National Medical Research Center for Preventive Medicine of Minzdrav of Russia, 101990, Moscow, Petroverigskiy lane, 10, str., 3
Keywords: коронарный атеросклероз, нормолипидемия, субфракционный спектр, ЛПНП Липопринт-система, coronary atherosclerosis, normolipidemia, subfractional profile, Lipoprint LDL system
Background: Plasma apo B-containing lipoproteins of low densities represent a heterogeneous population of particles varying by physicochemical composition, functional activity, and atherogenicity. Aim: To study some peculiarities in low density lipoproteins subfractional distribution in men with coronary atherosclerosis at normolipidemia. Material and methods: Patients with angiographically documented coronary atherosclerosis were included into the study ( n = 177; mean age 62.5 ± 9.3 yrs). Lipoprotein subfractional distribution was analyzed using Lipoprint LDL System (Quantimetrix, USA). Results: Out the total cohort normolipidemic patients (total C < 5,0 mmol/l, TG < 1.7 mmol/l, LDL-C < 2.5 mmol/l) with coronary atherosclerosis were selected and thereafter were split into those without small dense LDL (sdLDL) - group 1, n = 16, and and group 2 with presence of sdLDL ( n = 22). Patients from group 2 had lower portion of IDLB: 7.0 ± 1.2 vs 8.5 ± 1.0 %, IDLА: 7.9 ± 1.7 vs 9.6 ± 2.5 %, and higher LDL2 portion: 7.0 ± 2.0 vs 4.3 ± 1.6 %. In group 2 C level in LDL2 was higher than in group 1 while in IDL B it appeared to be lower. Mean LDL particles size in group 2 was lower as well: 270.7 ± 1.3 и 273.8 ± 0.8 Е. Conclusion. In men with coronary atherosclerosis at normolipidemia two different patterns of subfractional distribution of apo B-containing lipoproteins were detected. Presence of sd LDL associated with decreased LDL size could be regarded as more atherogenic profile even at normal lipid levels.
E.V. Shakhtshneider1, P.S. Orlov1,2, L.V. Shcherbakova1, D.E. Ivanoshchuk1,2, S.K. Malyutina1, V.N. Maksimov1,2, V.V. Gafarov1, M.I. Voevoda1,2 1Institute of Internal and Preventive Medicine - Branch of Federal Research Institute of Cytology and Genetics of SB RAS, 630089, Novosibirsk, Boris Bogatkov str., 175/1 2Federal Research Center Institute of Cytology and Genetics of SB RAS, 630090, Novosibirsk, Academician Koptyug av., 2
Keywords: генетический рискометр, неблагоприятные исходы, инфаркт миокарда, APOE, CETP, сердечно-сосудистые заболевания, model of genetic risk, unfavorable outcomes, myocardial infarction, APOE, CETP, cardiovascular diseases
Aim: to form a panel of genetic markers for analyzing the risk of long-term adverse prognosis of cardiovascular diseases in Russia population. Material and methods. A sample of nine hundred individuals was formed within the framework of the HAPIEE project (age 45-69 years, middle age 53.9 ± 6.9, male/female - 50/50). Molecular genetic analysis was performed using PCR followed by restriction fragment length polymorphism analysis for the APOC3 gene rs5128 polymorphism, APOE gene rs429358 and rs7412, CETP gene rs708272, LPL gene rs320, SCARB1 gene rs5888, and SREBF2 gene rs2228314 . Results. 10 single nucleotide polymorphisms were analyzed for the inclusion in the risk model of adverse prognosis of cardiovascular diseases in Russia population. The APOE gene e4/e4 genotype (rs429358 and rs7412) was associated with the development of adverse cardiovascular outcomes for 7 years of observation. For the CETP gene rs708272, the association with the development of cases of fatal myocardial infarction for 7 years of observation was demonstrated for the genotypes carrying C allele. No statistically significant association with the risk of adverse prognosis of cardiovascular diseases was obtained for the APOC3 gene rs5128, LPL gene rs320, SCARB1 gene rs5888, and SREBF2 gene rs2228314 in this pilot study. Conclusions. Pilot data on the presence of statistically significant association with the risk of long-term adverse prognosis of cardiovascular diseases in Russia population were obtained for the APOE and CETP genes.
G.P. Smirnov1, T.A. Rozhkova1, M.Yu. Zubareva1, Yu.A. Shuvalova1, D.V. Rebrikov2,3, A.I. Kaminny1, V.N. Titov1, V.V. Kukharchuk1, P.P. Malyshev1 1National Medical Research Center of Cardiology of Minzdrav of Russia, 121552, Moscow, 3rd Cherepkovskaya str., 15A 2Pirogov Russian National Research Medical University of Minzdrav of Russia, 117997, Moscow, Ostrovityanova str., 1 3Kulakov National Medical Research Center of Obstetrics, Gynecology and Perinatology of Minzdrav of Russia, 117997, Moscow, Academician Oparin str., 4
Keywords: аторвастатин, АТФ-связывающий кассетный транспортер А1, полиморфизм гена АВСА1, семейная гиперхолестеринемия, R219K, rs2230806, ABCA1 gene polymorphism, atorvastatin, ATP-binding cassette transporter A1, familial hypercholesterolemia, R219K, rs2230806
Objective: to evaluate the effect of rs2230806 variant in the ABCA1 gene on lipid and apolipoprotein (apo)A-I and apoB levels after the atorvastatin treatment in patients with heterozygous familial hypercholesterolemia (FH). Material and methods. The study included 83 patients with FH according to the British clinical SBR-criteria of the disease, all patients received atorvastatin at a dose of 40 mg/day for 3 months.Genotypingthe rs2230806 polymorphism was determined by «real time» polymerase chain reaction (PCR) using adjacent samples and melting reaction products after PCR. Total cholesterol (TC) and triglycerides (TG) were determined by a unified enzymatic method, high - density lipoproteins (HDL) and low - density lipoproteins (LDL) - by a direct homogeneous method, apoproteins - by immunoturbidimetric method. Results. Carriers of allelic variant were 52.9 % of patients (with one allele in 31.4 %, with two in 21.4 %). We revealed a difference in the change from the initial values of TC (-40.2 % vs. -34.4 %; p = 0.041), LDL (-50.8 % vs. -44 %; p = 0.041) and apoB (-48 % vs. -38.3 %; p = 0.02) with greater response to atorvastatin in homozygous carriers (genotype A/A) compared with heterozygous (genotype G/A) ones. The selective analysis depending on the sex and genotype rs2230806 among male carriers of allelic variant revealed a significant increase in the levels of HDL and apoAI by 10.6 % and 15.5 %, respectively, while in patients without polymorphism these lipid parameters decreased (by 3.8 % and 3.9 %, respectively). Conclusion. The variant rs2230806 in the ABCA1 gene was associated with a significant lipid-lowering effect of atorvastatin, and also increased the levels of apoA-containing plasma lipoproteins in male patients with FH.
A.A. Kuznetsov, A.A. Kuznetsova, T.I. Batluk, V.N. Maksimov, M.I. Voevoda, S.K. Malyutina, Yu.P. Nikitin
Institute of Internal and Preventive Medicine - Branch of Feseral Research Institute of Cytology and Genetics of SB RAS, 630089, Novosibirsk, Boris Bogatkov str., 175/1
Keywords: факторы риска, полиморфизм гена ADRB1, Бругада-паттерн, ранняя реполяризация, фрагментация QRS, общая популяция, risk factors, ADRB1 gene polymorphism, Brugada-pattern, early repolarization, QRS fragmentation, general population
The dangerous electrophysiological shifts in the myocardium, with the exception of rare congenital canalopathies, are overwhelmingly secondary, being a consequence of various pathological conditions. These processes, in turn, can also be genetically determined. Thus, the association of indices of ventricular repolarization with polymorphism of adrenoreceptor genes is shown. The electrical instability of the myocardium, apparently, has a multigenic and multifactorial basis. The aim of the study was to study the relationship between the risk factors and the polymorphism of the ADRB1 gene with pro-arrhythmic electrocardiographic patterns in the general population of Novosibirsk. Material and methods. Materials of epidemiological study of the general population of Novosibirsk under the WHO project «MONICA» (a sample of 831 men aged 25-64 years) were used. For genetic research 195 people were randomly selected. ECG-patterns were identified in a 30 % subsample - 261 people. The number of people with both genetic and electrocardiographic data was 105 people. According to the WHO criteria, components of the metabolic syndrome were identified. The A145G (rs1801252) polymorphism of the ADRB1 gene was determined. The Brugada, early repolarization, QRS fragmentation patterns were detected according to current criteria. The multivariate general linear model (GLM) were applied. Results. The QRS fragmentation was independently associated with obesity ( p = 0.014), increased TG level ( p = 0.040), decreased HDL cholesterol level ( p = 0.00079) and polymorphism of the ADRB1 gene (p = 0.00019). Conclusion. The integral approach is advisable in analyzing the genetic, metabolic and electrophysiological factors causing the electrical instability of the myocardium.
The features of lipid and carbohydrate metabolism in the indigenous population of the north of Yakutia are studied depending on ethnicity. The analysis of blood parameters found that the average values of atherogenic low-density lipoprotein cholesterol exceeded reference values in all ethnic groups. The high frequency of hypercholesterolemia due to the atherogenic fraction in all ethnic groups was shown, the highest was observed in Evenks and Yakuts. The frequency of hyperglycemia is significantly higher in the Dolgans, Evenks and Yakuts in comparison with other ethnic groups.
A.K. Ovsyannikova, L.V. Shcherbakova, S.V. Mustafina, Yu.I. Ragino, D.V. Denisova, A.K. Kuntsevich, O.D. Rymar
Institute of Internal and Preventive medicine - Branch of Federal Research Institute of Cytology and Genetics of SB RAS, 630089, Novosibirsk, Boris Bogatkov str., 175/1
Keywords: сахарный диабет 2 типа, липидный профиль, молодые пациенты, type 2 diabetes mellitus, lipid profile, young patients
Diabetes mellitus (DM) is one of the most important not only medical but also social problems. With the development of vascular complications in people with diabetes in all age groups associated with the presence of dyslipidemia which is why these patients need to determine the lipid spectrum. In 30 patients aged 45 years with newly diagnosed type 2 diabetes (DM2) and in a control group comparable in sex, age and body mass index (BMI), the lipid profile was studied. Statistically significant differences were not detected not by one indicator between persons with hyperglycemia and with normoglycemia but the average levels of total cholesterol and low-density lipoprotein cholesterol were higher than the target values in both groups. There are no gender differences either. Perhaps this is due to a small amount of DM at which metabolic changes have not yet developed.
O.V. Timoshchenko, Yu.I. Ragino, E.M. Stakhneva, Yu.V. Shchepina, E.V. Kashtanova, L.D. Latyntseva
Institute of Internal and Preventive Medicine - Branch of Federal Research Institute of Cytology and Genetics of SB RAS, 630089, Novosibirsk, Boris Bogatkov str., 175/1
Keywords: белок Клото, старение, липиды, ЛП(а), коэффициент атерогенности, Klotho protein, aging, lipids, Lp(a), atherogenic index
Purpose of the study. To study the special of protein Klotho and lipid profile in blood in young men and middle-aged men. Material and methods. Men ( n = 71) at the age of 20-35 years old (I group) and 50-65 years old (II group) were examined.Patients underwent general clinical, anthropometric, biochemical and instrumental examinations. The concentration in the blood serum of the Klotho protein was measured by the immunoenzyme technique ELISA. The content of total cholesterol and its components was determined by enzymatic methods. Results. The mean serum of protein Klotho in men I group was 687.6 ± 222.8 pg/ml, in II -1051.6 ± 121.5 pg/ml. The differences are significant - 1.5 times, but statistically unconvincing ( p = 0.161). A positive correlation was obtained between the protein Klotho and lipid metabolism indices: TC, TG, VLDL,non-LDL cholesterol, atherogenic index and inverse correlation with HDL-cholesterol. Conclusion.There is a tendency to increase with age the content of lipid components in the blood - non-HDL cholesterol, LDL-cholesterol, VLDL and atherogenic index. It can be concluded that, at the age of 20-65 years, the level of protein Klotho remains a tendency to increase in parallel with an increase in lipid parameters, in particular, the atherogenic index.
