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Polylactic acid (polylactide) is the most widely used biodegradable polymer. To eliminate its brittleness and low flexibility, various approaches to plasticization are used, in particular, compounding with more flexible polymers. The possibilities of plasticizing polylactide with polycaprolactone and polybutylene adipate/terephthalate by mixing polymers in a solution with subsequent film formation have been studied as well as the thermophysical and mechanical characteristics of the resulting film materials have been studied. The effect of plasticizer additives on the phase structure of polylactide with a decrease in its crystallinity and crystallite perfection was found. Thus, a plasticizing effect with polylactide amorphization was observed. The flexibility of the materials increased, as evidenced by the increase in the relative elongation under tensile strain of the films.

This paper presents the results of the development of automatic control systems for walking dragline excavator digging process. The process enables operational productivity to be enhanced through optimizing digging process. This also prevents extreme loads on machinery and hoist cable deflection. The paper also describes mathematical models of the electric drives of the main excavator machinery which form the bucket motion and the model of cable length change. Further the study will analyse the tructure of the control system and the automatic digging algorithm. Computer modeling findings are also described to confirm the operability of the automatic digging algorithm. Computer simulation of the processes in electric drives of main machinery of a walking dragline in digging operations was performed by means of SimInTech software. The automatic control system optimizes digging trajectory with very fast penetration with permissible overregulation following digging at a constant cut depth. The integrated system of dragline operation process control is practically independent due to the following factors: the automatic digging control system in combination with automatic systems for transporting the loaded bucket to dump and the empty bucket to the face; the automatic main machinery overload protection systems; and the system of control over safe bucket movement in the dragline working space.

This paper presents the results of the photometric CCD observations of the NEA (2100) Ra-Shalom carried out on August 24–29, 2019, at the 1-m telescope of the Sanglokh Observatory of the Institute of Astrophysics, National Academy of Sciences of the Republic of Tajikistan. The rotation period P = 19.8 ± 0.1 h was determined. Composite light curves were plotted in the photometric BVR bands; the brightness amplitude ΔV = 0.61m ± 0.05m and the average values of the color indices B–V = 0.75m ± 0.05m, V–R = 0.40m ± 0.02m were determined. Variations in the color indices with rotation period are within the measurement errors, which indicates that the reflectivity of Ra-Shalom’s surface is uniform. The absolute stellar magnitude of the asteroid is 15.91m ± 0.10m. The ratio of the asteroid’s axes a/b = 1.75.

We present results of polarimetric, photometric, and spectral observations of the near-Earth asteroid (3200) Phaethon carried out at the 6-m BTA telescope of the Special Astrophysical Observatory and the 2.6-m and 1.25-m telescopes of the Crimean Astrophysical Observatory over a wide range of phase angles during its close approach to the Earth at the end of 2017 (19-135 deg) and in 2020 at \alpha = 52.2 deg. Using our and other available in literature data, we found that the maximum degree of linear polarization of Phaethon in the V band is 45% at the phase angle 124 deg. Using the dependence (polarimetric slope-albedo) we have found the geometric albedo of asteroid Phaethon to be 0.06. This value falls into the lower range of albedo values for asteroids determined by different methods. The mean color indices U-B=0.207 and B-V=0.639 of the asteroid are derived at heliocentric and geocentric distances 1.077 au and 0.102 au, respectively. The effective diameter of Phaethon is estimated from obtained absolute magnitude and geometrical albedo, it is equal to 6.8 km. The best fit to the observed polarimetric data was obtained with the Sh-matrix model of conjugated random Gaussian particles composed of Mg-rich silicate (90%) and amorphous carbon (10%)., Comment: 27 pages, 9 figures

Data is presented on estimation calculations of the energy potential of the rivers of Russia, and the history of the development of a small hydropower in the Russian Federation is briefly explained. The current use of energy resources and the prospects for their further utilization worldwide in different countries of the world are examined. The basic difficulties of developing small hydropower in Russia are defined, and provisions for development of small hydropower are proposed.

The results of the measurement of the surface temperature of a flat plate in a supersonic air-droplet flow are presented. The plate made of duralumin was mounted vertically in the working channel of an aerodynamic setup. The droplets of a liquid (distilled water) were pulverized into an air flow in a plenum chamber through centrifugal atomizers. The mass concentration of the liquid was about 0.36 and 0.27%, the mean droplet diameter according to Sauter was about 110 μm, and the freestream Mach number M = 2.5 and 3.0. The surface temperature was measured by an IR imager. The measured plate surface temperatures for the case of single-phase air flow (without droplets) were compared with those for the air-droplet flow at the same parameters (with respect to the air) in the plenum chamber. To intensify the droplet sedimentation on the plate a shock generator in the form of a wedge was mounted vertically ahead of the plate.

Water ice is widespread in the Solar System. Computer simulation of light scattering by ice particles designed to interpret the observational data should take into account the spectral dependence of the refractive index of water ice. However, in practice, a single fixed value of the refractive index is often used. In this paper, we show that poor choice of a fixed refractive index commonly leads to significant errors in estimating both the intensity and the degree of polarization of single-scattered light. We have found that a fixed value of the refractive index of ice particles m0 = 1.3078 in the spectral region from 0.4 to 0.9 μm leads to minimal differences between the calculated characteristics of the light scattered by ice particles and those that take into account the spectral behavior of the refractive index. The most suitable values of the fixed refractive index for the widely used R, V, and I filters have been found. We have also studied the effect of the fixed refractive index of ice on the spectral dependence of the main parameters of the phase dependence of the linear polarization degree of single-scattered light, such as the magnitude and position of the minimum of the negative branch, the magnitude and position of the maximum of the positive branch, the inversion angle, and the polarimetric slope. The results of the calculations can be used to interpret the polarization of various objects of the Solar System that contain ice particles.

The results of polarimetric observations of the asteroid (599) Luisa carried out on the same type of aperture photoelectric polarimeters of the 2.6-m reflector of the Crimean Astrophysical Observatory and the Zeiss 2000 telescope of the Terskol Peak Observatory in November 2018 and February 2019 are presented. Based on these and available literature data, the parameters of the composite phase dependence of the polarization degree are obtained: Pmin = –1.68%, αmin = 14.7°, αinv = 29.2°, which indicates that the asteroid belongs to the class of “Barbarians”. The absolute value of the negative polarization degree of the asteroid in the range of the BVRI photometric bands is shown to increase with wavelength, which contradicts the data of Bagnulo et al. (2015) but is consistent with the spectral polarization behavior of other silicate S-, K-, and L-type asteroids, including well-known Barbarians. Possible causes of differences in the spectral behavior of the polarization degree of this asteroid are discussed. The properties of the asteroid (599) Luisa are unique in that it combines spectral properties of silicate L-type asteroids and polarization properties (Pmin and the slope h) of low-albedo C and Ch asteroids.

The present work is devoted to the experimental study of a high-speed jet exhausting from a model dual-stream jet nozzle which was performed using non-contact (shadow visualization) and probing (Pitot pressure tube) methods for measuring gas-dynamic parameters. Azimuthal non-uniformity of the pressure distribution, whose magnitude in the external duct is much higher than that in the internal one, is revealed. The cause for the formation of the 3D flow structure is related to the supporting pylons installed inside the nozzle contours and with the formation of a transonic flow mode in the external duct.

Проблематика данной работы выражается в недостаточной сформированности методического аппарата, регулирующего вопросы технической защиты информации в качестве части информационной безопасности. Основной целью представленной статьи является изучение вопроса технической защиты информации в качестве ключевой составляющей информационной безопасности критически важной инфраструктуры.

The use of hyperspectral imaging and multivariate analysis to detect weathering effects and mineral additive content in LDPE composites is demonstrated. Principal component analysis of hyperspectral images was used to obtain models of composite gradation by additive content and presence of weathering effects. The analysis of the factor loading matrix of spectral wavelength reflectance coefficients revealed the most significant bands contributing to the gradation of composite samples by additive content and presence of weathering effects.

This article presents a model of conjugated Gaussian random particles, which are convenient for simulation of irregular particles that constitute cometary dust. Computer simulation is conducted for the polarimetric properties of these particles; phase dependences are calculated for the linear polarization degree. The calculated results are used to interpret cometary polarimetric observations and determine possible physical and chemical characteristics of comets as well as the variation range within which the model adequately describes the observed data. The model calculations are used to refine the empirical formula that describes the phase dependence of the linear polarization degree for the cometary continuum.

Energy (temperature) separation is the redistribution of the total enthalpy (stagnation temperature) in a gas flow without external work and heat exchange with the ambient medium. Some simple devices for obtaining “hot” and cold” flows of compressed gas can be developed on the basis of the temperature separation effect. The best known of these devices is, apparently, the Ranque-Hilsch vortex tube. In this study, a new method of the temperature separation of gas flows is described and the first systematic experimental data are obtained. The method is based on the well-known effect of energy (temperature) separation in the boundary layer of a compressible gas flow. The “cold” regions layers are separated from the “hot” ones in a device consisting of a nozzle and a cylindrical tube with a permeable wall. When compressed air flows out into the atmosphere through this device, a part of the flow seeps through the permeable wall due to a steady pressure gradient. Its stagnation temperature turns out to be smaller than the initial temperature, whereas the stagnation temperature of the other part of the flow is greater than the initial temperature. In the pressure and temperature ranges considered the cooling effect is by a factor of about five greater than that of Joule—Thomson. The initial pressure of the compressed air varied in the range from 1.2 to 8.0 bar, while the initial temperature was 295.6 K. Both convergent and convergent-divergent (supersonic) nozzles were used. The temperature separation increases with increase in the initial pressure up to a certain value but it remains almost constant after this value has been attained. The greatest temperature difference between the “hot” and “cold” flows is about 11 K.

The results of the first polarimetric measurements of near-Earth asteroid 2014 JO25 and comet 41P/Tuttle-Giacobini-Kresak performed on April 19, 2017, with a CCD sensor at the prime focus (f/3.85) of the 2.6-m Shajn Telescope of the Crimean Astrophysical Observatory in the R filter are reported. The degree of linear polarization of the asteroid is P = 2.69 ± 0.44% at a phase angle of 55.6°, which is typical of an S-type asteroid. Its geometric albedo is ρv ≈ 0.2. A digital filter applied to the direct image of the comet reveals a jet and a tail directed toward the Sun (PA = 45.1°) and away from it (PA = 241.2°), respectively, in the coma. The maximum degree of linear polarization in the near-nucleus region of the comet is 18% at a phase angle of 69.8°. The polarization decreases to 16.2–10.7% in coma regions with a radius of 865–4856 km. Various factors affecting the maximum degree of polarization and the polarization-degree distribution over the coma are discussed.

The drag and heat transfer coefficients of smooth and dimpled surfaces located in the wake of a cylinder are experimentally determined. The cylinder, 8 mm in diameter, was placed in a 30 mm-high slot channel. In the experiments the cylinder position along the channel height and the dimpled surface geometry varied: the gap between the cylinder and the wall under consideration ranged from 0 to 21 mm and the in-line arrangement of spherical dimples and the staggered arrangements of spherical and oval dimples were considered. In determining the drag coefficients the Reynolds number based on the cylinder diameter varied in the range Red = 10.9–53.3∙103. In determining the heat transfer coefficients the Reynolds number was Red = 53.3∙103. The cylinder was unheated. The drag coefficients of the smooth and dimpled surfaces were determined by directly weighing the models on a single-component strain-gauge balance. The local values of the heat transfer coefficients were determined by means of recording the rate of the model surface cooling using an IR imager. The heat transfer and drag coefficients in the cylinder's wake divided by their values on the smooth wall in the undisturbed flow varied in the ranges 0.98–2.64 and (−1.65)-(1.95) for the smooth and 0.75–3.34 and (−3.77)-(4.5) for the dimpled surfaces. The Reynolds analogy factor for the above-mentioned models ranged from 0.45 to 7.73 depending on the particular surface and the gap between the cylinder and the wall.

Hepatitis A virus (HAV) continues to cause outbreaks of viral hepatitis, which remains a socially significant disease despite existing vaccines. During the production of vaccines, HAV strains that require prolonged incubation of infected cell cultures, up to 4 weeks, are used. Several HAV strains, which are fast-growing on cell cultures, up to 7–10 days, are known. This paper presents the results of virological characterization and analysis of the genome of the HAV strain MB-7/293 (HepA-293) derived from MB-7/4647, one of the fast-growing strains, which was obtained by adapting it to HEK293 cell culture (human embryonic kidney cells). It was shown that the MB-7/293 strain significantly exceeds the parent MB-7/4647 strain in productivity when cultured on HEK293 cell culture, i.e., in the yield of the infectious virus and the virus-specific antigen. Analysis of the nucleotide sequence of full-length genomic RNA of the MB-7/293 strain showed that it differs from the genome sequence of MB-7/4647 in three nucleotide substitutions in the 5'-untranslated region and 20 nucleotide substitutions in the coding region, which lead to substitutions of ten amino acid residues in the proteins VP3, VP1, 2B and 2C. Comparative analysis of the genomic sequences of the strains MB-7/293, MB-7/4647, and other HAV strains, including the previously described fast-growing strains, allowed to reveal mutations that affect the reproductive properties of the virus.

The degree of linear polarization of the main-belt asteroid 47 Aglaja was measured at low phase angles. The data obtained made it possible to construct a complete branch of the negative polarization. Comparison with asteroids of the same spectral type and having equally high albedo values showed that asteroid 47 Aglaja has a much smaller negative polarization branch, which indicates a possible difference in the chemical composition or structure of matter on the surface.

Detailed data on the measurement of the gas-dynamic parameters of the flow in the jet field at a large value of the relative total pressure (Npr = 70) are presented. A significant increase in the measured total pressure in the first cell of a supersonic weakly underexpanded jet has been experimentally revealed. An explanation is given of this effect associated with the mixing process in the region behind the Mach disk of the peripheral high-pressure flow and the axial flow behind the Mach disk. This explanation based on the data of the numerical calculation of the flow. Experimental data can be used to verify the results of numerical calculations.

This article offers a solution of research problem connected with updating of the compatibility principles of research in crisis periods of society. It analyzes the influence of information fields and processes of informatization on the system of education, the problems of scientific research, on the role of the pedagogical and scientific community in modern conditions

In the presented case report, the complex approach of rehabilitation in the remote period of traumatic brain injury (TBI) allowed the achievement of the significant clinical effect. The authors analyzed the experience of reflex therapy in the treatment of TBI. The effectiveness and potential of acupuncture, objectification of the results are topical issues that require further research.Представлен случай комплексного подхода к реабилитации в отдаленном периоде черепно-мозговой травмы (ЧМТ), который позволил достичь значимого клинического эффекта. Наряду с активной и пассивной двигательной реабилитацией, нейропсихологическим и медикаментозным воздействием, авторами был использован метод рефлексотерапии (акупунктура). Сделан вывод об эффективности и высоком потенциале применения акупунктуры при ЧМТ. Подчеркивается необходимость дальнейших исследований в этой области.

The present paper is an experimental and numerical analysis of a new method of energy separation. By energy separation, we mean the spontaneous separation of the gas flow into two flows with stagnation temperatures above and below the initial (“hot” and “cold”). One of the most famous devices using the phenomenon of energy separation is the Rank-Hilsch vortex tube. The considered method is based on the well-known effect of the stagnation temperature profile curvature over the boundary layer thickness, which occurs when a high-speed gas flows around an adiabatic surface. It is known that the higher the flow velocity and the more the Prandtl number differs from unity, the higher the energy separation within the boundary layer. In a channel with a permeable wall, part of the high-speed flow can be sucked out through the wall due to the natural pressure drop. As a result, the flow's stagnation temperatures at the outlet of the channel and the flow sucked out through the wall are different: one is hotter, the other is colder compared to the initial stagnation temperature. Based on the obtained experimental data, validation of one- and two-dimensional mathematical models was carried out. The influences of the initial Mach number, the initial stagnation pressure, the relative channel length, and the Prandtl number on the energy separation were investigated. It was found that as the initial Mach number changes from Mis = 1 to Mis = 3, the air flow's cooling increases from −5 to −15 K. When the Prandtl number changes from Pr = 0.7 to Pr = 0.2, the flow's cooling is increased by factor of 2.25 from −20 to −45 K. It is shown that at a certain ratio of parameters, the heating and the cooling of flows pass through an extremum. The obtained temperature difference due to the suction of a part of the flow can find application in the analysis of flows with variable mass flow rates in power systems, such as heat pipes, boundary layer control devices, etc.

The requirements of regulatory documents imposed on the selection of control samples of coarse fragmental material often hamper the rate of erection of earth and rockfill dams and complicate operational assessment of work quality. Through the evaluation of the possibility of quality control of the stacking of coarse fragmental material in pits of reduced size by controlling the density of all the soil material relative to the density of fractions 200 mm, similar to the determination of the entire soil density relative to the density of fine material (5 mm), it becomes possible to optimize these types of operations without worsening their quality.

The turbulent properties of a supersonic jet were studied related to a high level of pressure pulsation found in model jets of a reentry flight vehicle approaching the landing ground. This study comprised measurements of total pressure at a small-size target using a dynamic pressure probe placed in a free jet. The most comprehensive data about jet turbulence can be obtained by direct transformation of the pressure reading at the stagnation point near the target into the normalized velocity. The oscillogram of normalized velocity produces the velocity average value, root-mean-square value as well as turbulence intensity and turbulence spectrum. It was demonstrated that a high level of turbulence for a high-head jet retains along the supersonic core length and at the beginning of subsonic interval.

The transport of one-dimensional CuI crystals in channels of single-walled carbon nanotubes (SWCNTs) has been studied by high resolution electron microscopy. The diffusion kinetics has been investigated by counting the number of CuI atoms escaping from the nanotube channel. The diffusivity is calculated to be 6.8 × 10–21 m2/s, which corresponds to an activation-barrier height of ~1 eV/atom. A comparison with the theoretically estimated height of the energy barrier for molecular transport through a graphene layer is indicative of mass transfer through vacancy defects in graphene.

In astrophysical studies of Solar System bodies, the measured values of the linear polarization degree Pobs and the position angle of the polarization plane θ are usually considered relative to the plane orthogonal to the scattering plane; and the resulting quantities are designated as Pr and θr, respectively. Parameters of the phase curve of polarization Pr = f(α) serve for determining the physical characteristics of grains composing the regolith surfaces of such bodies as, for example, the Moon, Mercury, asteroids, and planetary satellites, or the polydisperse media, such as cometary comae and tails. In this paper it has been shown that the error in the polarization degree grows $${\sigma _{{P_r}}}$$ due to the error $${\sigma _{{\theta _{obs}}}}$$ in determining the position angle. The interrelations between these errors were obtained, and the conditions, under which the values of the linear polarization degree Pr relative to the orthogonal system can be used to analyze the phase dependences of polarization, were formulated.

Aim . To improve the efficiency of treatment of advanced liver alveococcosis using modern surgical techniques including transplantation. Material and Methods. It was analyzed surgical treatment of 25 patients with advanced liver alveococcosis for the period 2008–2014. Operations were performed in 21 cases. Lung metastasis were diagnosed in two of them. Long-term obstructive jaundice was observed in 5, portal hypertension – in 2. 1 patient with associated HBV had liver cirrhosis. Results . Surgical interventions had extended volume and included liver resection “in situ” in 16 cases, orthotopic liver transplantation (OLT) in 3 patients. Invasion into IVC was detected in 9 cases. In 6 patients IVA was made a prosthetic appliance using PTFE-prosthesis including 1 case with left hepatic vein orifice repair and 3 cases with partial resection. Resection and reconstruction of portal vein were required in 6 cases. 9 patients underwent resection of the extrahepatic bile ducts. Resection of the right dome of the diaphragm was made in 4 cases. In one case explorative laparotomy was performed. All patients after surgery receive antiparasitic therapy. There was 1 death in the early postoperative period due to multiple organ failure. There were no recurrences within 7-year follow-up. Antiparasitic therapy after liver transplantation did not require adjustment of immunosuppressive therapy. Conclusion . Surgical interventions for liver alveococcosis have advanced volume and are combined with reconstruction of great vessels and bile ducts. Maximum tendency to resection is caused by potential risk of immunosuppressive therapy after transplantation for the progression of the disease, that justifies difficult resections “ex situ”.

The paper presents the results of an experimental study of the parameters of the boundary layer, distribution of static pressure, heat transfer and friction coefficients of smooth surface located in the wake behind the cylinder in the channel. Cylinders of various diameters were placed in a slotted channel with a height of 30 mm on its axis. In all experiments, the flow velocity at the inlet was 50 m/s. The cylinder was made unheated. The friction coefficients of the smooth model were determined both from the velocity profile in the boundary layer and by direct weighing of the model on a one-component strain-gage balance. The local values of the heat transfer coefficients were determined by transient heat-transfer method using a thermal imager. The values of the heat transfer and friction coefficients in the wake behind the cylinder, referred to the values on the smooth wall in the undisturbed flow, varied in the range 1.15–1.65 and 1.3–1.75, respectively. The value of the Reynolds analogy factor for all cylinder diameters turned out to be less than unity.

The paper presents the results of measuring the adiabatic wall temperature of an axisymmetric channel during acceleration of the moist air flow in it to supersonic speed. The initial swirl was imparted to the flow (swirling parameter S = 0.5, 1.0, 2.5). The relative initial humidity (RH) of the flow varied in the range of 10 ÷ 90%. When the flow was accelerated to supersonic speeds, part of the moisture condensed, which influenced the wall temperature. It is shown experimentally that with an increase in the initial moisture content of the flow to certain values, the distribution of the wall temperature for a flow without initial swirl (S = 0) and with swirl with S = 0.5, 1.0 practically coincide. However, from a certain value of RH, the wall temperature in the case of a swirling flow decreases in comparison with a flow without swirling. The maximum decrease in the wall temperature was achieved at RH = 90%. An increase in the initial swirl to S = 2.5 led to a greater decrease in the wall temperature, while the mass air flow through the channel decreased by 26% at an identical pressure drop.

The paper presents the results of an experimental study of influence of a weak and moderate nonequilibrium adverse pressure gradient (APG) on the parameters of the dynamic and thermal boundary layers. The Reynolds number based on the momentum thickness at the beginning of the APG region was Re **=5500. The section of the channel with APG was a slotted channel with an opening angle of the upper wall of 0-14°. The values of the relative (referred to the parameters in a zero pressure gradient flow at the same Re **) friction and heat transfer coefficients, as well as the Reynolds analogy factor depending on the longitudinal pressure gradient, are obtained. The values of the relative friction coefficient decreased to cf/cf0 =0.7 and those of the heat transfer to St/St0=0.9. A maximum value of the Reynolds analogy factor (St/St0)/(cf/cf0 )=1.16 was reached for the pressure gradient parameter β=2.9. The ratio of the heat transfer and drag coefficients of the dimpled to smooth surfaces remained approximately constant regardless of the presence or magnitude of a adverse pressure gradient.

The process of energy (temperature) separation in an airflow is experimentally investigated in a device consisting of two coaxial channels with heat-conducting walls. The air flows at a supersonic velocity along the inner channel and at a subsonic velocity in the outer channel. The initial total temperatures of the flows are the same. Heat transfer arises due to the energy separation effect in the boundary layer of the compressible flow at Pr ≠ 1. The parameters varied in the process of investigation are the initial flow temperature, the supersonic flow velocity (Mach number), the mass fraction of the subsonic flow, the scheme of the flow organization in the device, and the presence/absence of heat transfer intensifiers in the subsonic channel. In all the regimes considered the subsonic flow cooling and the supersonic flow heating were fixed. The total pressure of the subsonic flow was almost conserved in the maximum cooling regimes. An engineering method of calculating the temperature separation in the similar devices is proposed. The expressions for the limiting values of the flow heating and cooling corresponding to the energy separation using this technique are obtained. The flow parameters that have an effect on the temperature separation efficiency are determined.

The paper presents a description of the procedure used for determining the aerodynamic characteristics (forces and moments acting on a model of a flying vehicle) obtained from the results of pressure measurements on the surface of a model of a re-entry vehicle with operating retrofire brake rockets in the regime of hovering over a landing surface is given. The algorithm for constructing the interpolation polynomial over interpolation nodes in the radial and azimuthal directions using the assumption on the symmetry of pressure distribution over the surface is presented. The aerodynamic forces and moments at different tilts of the vehicle are obtained. It is shown that the aerodynamic force components acting on the vehicle in the regime of landing and caused by the action of the vertical velocity deceleration nozzle jets are negligibly small in comparison with the engine thrust.

Cancer cells develop increased sensitivity to members of many virus families and, in particular, can be efficiently infected and lysed by many low-pathogenic human enteroviruses. However, because of their great genetic heterogeneity, cancer cells display different levels of sensitivity to particular enterovirus strains, which may substantially limit the chances of a positive clinical response. We show that a non-pathogenic strain of coxsackievirus B6 (LEV15) can efficiently replicate to high titers in the malignant human cell lines C33A, DU145, AsPC-1 and SK-Mel28, although it displays much lower replication efficiency in A431 and A549 cells and very limited replication ability in RD and MCF7 cells, as well as in the normal lung fibroblast cell line MRC-5 and the immortalized mammary epithelial cell line MCF10A. By serial passaging in RD, MCF7 and A431 cells, we obtained LEV15 strain variants that had acquired high replication capacity in the appropriate carcinoma cell lines without losing their high replication capability in the original set of cancer cell lines and had limited replication capability in untransformed cells. The strains demonstrated improved oncolytic properties in nude-mouse xenografts. We identified nucleotide changes responsible for the phenotypes and suggest a bioselection approach for a generation of oncolytic virus strains with a wider spectrum of affected tumors.

The results of an experimental investigation of the heat transfer and the drag on surfaces coated with dimples are presented. The dimples of six different shapes were considered, namely, spherical, oval, and teardrop dimples, spherical dimples with rounded edges, turned teardrop dimples, and dimples obtained by milling a sphere along a circular arc. The distinctive feature of the study is that the relative drag and heat transfer coefficients were simultaneously recorded during the same run of the experimental setup. The drag coefficients were determined by directly weighing the models under study using a one-component strain gauge balance. The heat transfer coefficients were determined by means of the unsteady heat transfer method using the IR camera. The Reynolds number based on the boundary layer length ranged from 0.2·106 to 7·106. The two-dimensional fields of the heat transfer coefficient on the dimpled surfaces are presented, together with the data of the flow visualization. The Reynolds number effect on the heat transfer enhancement, the drag increase, and the heat-hydraulic efficiency is determined. The average values of the above-mentioned parameters are presented for all the surfaces considered.

Observations of near-Earth asteroids at large phase angles made it possible to obtain a more complete (for ground-based observations) phase dependence of the polarization of the E-type asteroids’ radiation including the maximum of the positive branch of the linear polarization degree. It is shown that the position of the polarization maximum of high-albedo asteroids is noticeably shifted to the decrease of phase angles compared with S-type asteroids. Model calculations of polarimetric properties of random Gaussian particles that simulate dust particles on the regolith surface are carried out. Model calculations show a qualitatively similar behavior pattern of parameters of the positive polarization branch. The influence of the refractive index of individual scattering particles on the size and position of the maximum of the positive branch of the linear polarization degree is investigated within the considered model.

We investigate the photometric and polarimetric behavior of the blazar S5 0716+714 based on the observations carried out in 1991–2004 at the 125-cm Crimean Astrophysical Observatory telescope (AZT11) with a photopolarimeter that allows simultaneous polarization and brightness measurements to be made in the U BV RI bands. We also provide the U BV photometry for the blazar obtained in 2000–2009 with a 60-cm telescope at the Crimean Station of the Sternberg Astronomical Institute. The pattern of flux variability and the correlation between the brightness, color, and polarization variations have been investigated. In this time interval the blazar showed a significant brightness and polarization variability similar to noise processes.

The structural organization of compounds in a confined space of nanometer-scale cavities is of fundamental importance for understanding the basic principles for atomic structure design at the nanolevel. Here, we explore size-dependent structure relations between one-dimensional PbTe nanocrystals and carbon nanotube containers in the diameter range of 2.0-1.25 nm using high-resolution transmission electron microscopy and ab initio calculations. Upon decrease of the confining volume, one-dimensional crystals reveal gradual thinning, with the structure being cut from the bulk in either a110or a100growth direction until a certain limit of ∼1.3 nm. This corresponds to the situation when a stoichiometric (uncharged) crystal does not fit into the cavity dimensions. As a result of the in-tube charge compensation, one-dimensional superstructures with nanometer-scale atomic density modulations are formed by a periodic addition of peripheral extra atoms to the main motif. Structural changes in the crystallographic configuration of the composites entail the redistribution of charge density on single-walled carbon nanotube walls and the possible appearance of the electron density wave. The variation of the potential attains 0.4 eV, corresponding to charge density fluctuations of 0.14 e/atom.

To create a new type of catalytic gas diffusion layer for a high-temperature hydrogen/air polymer-electrolyte membrane fuel cell (HT-PEMFC), a new electrospun carbon nanofiber (CNF)-based platinized nanocomposite was formed. Its structure was studied by scanning, high resolution transmission and scanning transmission electron microscopy, electron diffraction, EDX analysis, electron tomography and Raman spectroscopy. The temperature dependence of the morphology and structure of carbon nanofibers was investigated: high annealing temperatures (1200 and 2800 °C) led to graphitization with straight graphene layer sets in nanofiber bodies, whereas curly graphene layer sets were observed for Fe-containing annealing. Platinization of CNFs with further heating at elevated temperature (280 °C) led to the formation of spherical nanoparticles of 3.0 nm diameter, while at room temperature “finger”-like nanoparticles with a length up to 20 nm grew along directions. Structural evolution of the nanofibers resulted in an increase of their porosity, electroconductivity and thermal stability, as well as formation of a CNF surface relief providing a smoother and more uniform platinum nanoparticle cover. The most uniform one was obtained on carbon fibers synthesized from a polymer mixture and further graphitization in the presence of iron nanoparticles.

(Vѣsti. General. Gig., Court. Practice. Medicine, 1897, February).