Nuclear Technology for Oncology
Krivopnos S. O. (h-index: 25), Armen Nersesian, a professor at the Department of Higher Mathematics and Mathematical Physics.
Journal: Journal of High Energy Physics (IF 6.023; Q1)
Performing the Hamiltonian analysis we explicitly established the canonical equivalence of the deformed oscillator, constructed in arXiv:1607.03756, with the ordinary one. As an immediate consequence, we proved that the SU(1, 2) symmetry is the dynamical symmetry of the ordinary two-dimensional oscillator. The characteristic feature of this SU(1, 2) symmetry is a non-polynomial structure of its generators written in terms of the oscillator variables.
Valeria Kudryavtseva, an engineer at the Laboratory for Neuroprotection , Tomsk RASA Center, et al.
Journal: Scientific Reports (IF 5.228; Q1)
Polyelectrolyte complexes (PEC) are formed by mixing the solutions of oppositely charged polyelectrolytes, which were hitherto deemed “impossible” to process, since they are infusible and brittle when dry. Here, we describe the process of fabricating free-standing micro-patterned PEC films containing array of hollow or filled microchambers by one-step casting with small applied pressure and a PDMS mould. These structures are compared with polyelectrolyte multilayers (PEM) thin films having array of hollow microchambers produced from a layer-by-layer self-assembly of the same polyelectrolytes on the same PDMS moulds. PEM microchambers “cap” and “wall” thickness depend on the number of PEM bilayers, while the “cap” and “wall” of the PEC microchambers can be tuned by varying the applied pressure and the type of patterned mould. The proposed PEC production process omits layering approaches currently employed for PEMs, reducing the production time from ~2 days down to 2 hours. The error-free structured PEC area was found to be significantly larger compared to the currently-employed microcontact printing for PEMs. The sensitivity of PEC chambers towards aqueous environments was found to be higher compared to those composed of PEM.
Gutsche T. (h-index: 33), Kovalenko S. (h-index: 32), Kuleshov S. V. (h-index: 69), Valery Ljubovitskij, a professor at the Department of Higher Mathematics and Mathematical Physics, Vacas M. J. (h-index: 26) et al.
Journal: Physical Review D (IF 4.506; Q2)
Using the present upper bound on the neutron electric dipole moment, we give an estimate for the upper limit of the CP-violating couplings of the η(η′) to the nucleon. Using this result, we then derive constraints on the CP-violating η(η′)ππ couplings, which define the two-pion CP-violating decays of the η and η′ mesons. Our results are relevant for the running and planned measurements of rare decays of the η and η′ mesons by the GlueX Collaboration at JLab and the LHCb Collaboration at CERN.
Evgeniy Bolbasov, an engineer at the Department of Experimental Physics, Igor Khlusov, a professor at the Department of Experimental Physics, Sergey Tverdokhlebov, an associate professor at the Department of Experimental Physics, et al.
Journal: Materials Science and Engineering C (IF 3.42; Q2)
This work presents composite coatings based on a copolymer of vinylidene fluoride with tetrafluoroethylene (VDF-TeFE) and hydroxyapatite (HA) for flexible intramedullary nails (FIN). The effect of the proportion of VDF-TeFE (100–25% wt.) on physicochemical and biological properties of the composite coatings was investigated. It was shown that a decrease of VDF-TeFE in the coating hinders its crystallization in β and γ forms which have piezoelectric properties. The decrease also reduces an adhesive strength to 9.9 ± 2.4 MPa and a relative elongation to 5.9 ± 1.2%, but results in increased osteogenesis. It was demonstrated that the composite coatings with 35% VDF-TeFE has the required combination of physicochemical properties and osteogenic activity. Comparative studies of composite coatings (35% VDF-TeFE) and calcium phosphate coatings produced using micro-arc oxidation, demonstrated comparable results for strength of bonding of these FINs with trabecular bones (~ 530 MPa). It was hypothesized that the high osteoinductive properties of the composite coatings are due to their piezoelectric properties.
Adamyan G.G. (h-index: 31), Nikolai Antonenko, a professor at the Department of Higher Mathematics and Mathematical Physics, et al.
Journal: Physical Review A (IF 2.765; Q1)
The non-Markovian Langevin approach is applied to study the dynamics of fermionic (bosonic) oscillator linearly coupled to a fermionic (bosonic) environment. The analytical expressions for occupation numbers in two different types of couplings (rotating-wave approximation and fully coupled) are compared and discussed. The weak-coupling and high- and low-temperature limits are considered as well. The conditions under which the environment imposes its thermal equilibrium on the collective subsystem are discussed. The sameness of the results, obtained with both the Langevin approach and the discretized environment method are shown. Short- and long-time nonequilibrium dynamics of fermionic and bosonic open quantum systems are analyzed both analytically and numerically.
Oleg Bogdanov, an associate professor at the the Department of Higher Mathematics and Mathematical Physics, et al.
Journal: Annals of Physics (IF 2.375; Q1)
The properties of radiation created by a classical ultrarelativistic scalar charged particle in a constant homogeneous crossed electromagnetic field are described both analytically and numerically with radiation reaction taken into account in the form of the Landau–Lifshitz equation. The total radiation naturally falls into two parts: the radiation formed at the entrance point of a particle into the crossed field (the synchrotron entrance radiation), and the radiation coming from the late-time asymptotics of a particle motion (the de-excited radiation). The synchrotron entrance radiation resembles, although does not coincide with, the ultrarelativistic limit of the synchrotron radiation: its distribution over energies and angles possesses almost the same properties. The de-excited radiation is soft, not concentrated in the plane of motion of a charged particle, and almost completely circularly polarized. The photon energy delivering the maximum to its spectral angular distribution decreases with increasing the initial energy of a charged particle, while the maximum value of this distribution remains the same at the fixed photon observation angle and entrance angle of a charged particle. The ultraviolet and infrared asymptotics of the total radiation are also described.
Anna Sachkova, an associate professor at the Department of Rare, Scattered and Radioactive Elements, Anna Vorobieva, a students at the Department of Rare, Scattered and Radioactive Elements, et al.
Journal: Photochemistry and Photobiology (IF 2.008; Q3).
A bioluminescent assay based on a system of coupled enzymatic reactions catalyzed by bacterial luciferase and NADH:FMN-oxidoreductase was developed to monitor toxicity and antioxidant activity of bioactive compounds. The assay enables studying toxic effects at the level of biomolecules and physicochemical processes, as well as determining the toxicity of general and oxidative types. Toxic and detoxifying effects of bioactive compounds were studied. Fullerenols, perspective pharmaceutical agents, nanosized particles, water-soluble polyhydroxylated fullerene-60 derivatives were chosen as bioactive compounds. Two homologous fullerenols with different number and type of substituents, C60O2–4(OH)20–24 and Fe0.5C60(OH) xOy (x + y = 40–42), were used. They suppressed bioluminescent intensity at concentrations >0.01 g L−1 and >0.001 g L−1 for C60O2–4(OH)20-24 and Fe0.5C60(OH)xOy, respectively; hence, a lower toxicity of C60O2–4(OH)20–24 was demonstrated. Antioxidant activity of fullerenols was studied in model solutions of organic and inorganic oxidizers; changes in toxicities of general and oxidative type were determined; detoxification coefficients were calculated. Fullerenol C60O2–4(OH)20–24 revealed higher antioxidant ability at concentrations 10−17−10−5 g L−1. The difference in the toxicity and antioxidant activity of fullerenols was explained through their electron donor/acceptor properties and different catalytic activity. Principles of bioluminescent enzyme assay application for evaluating the toxic effect and antioxidant activity of bioactive compounds were summarized and the procedure steps were described.
Dmitri Antonov, a student at the Department of Electric Grids, Timur Valiulin, a doctoral student at the Department of Heat and Power Process Automation, Roman Egorov, JRF at the Department of Heat and Power Process Automation, Pavel Strizhak, head of the Department of Heat and Power Process Automation.
Journal: Energy (IF 4.292; Q1)
We have observed the influence of an artificial macroscopic surface modification onto the ignition of droplets of the waste-derived coal water slurry with petrochemicals. Fuel composition was based on filter cake of bituminous gas-coal with inclusion of small amount of the waste oil fuel. The sizes and other parameters of the fuel droplets were chosen very close to used in typical power units. The fuel droplet surface was pierced making conical pores whose depth was more than half of the droplet radius. Changes of the ignition delay time were analysed together with features of the combustion of volatiles in vicinity of introduced macroscopic pores. The advanced mathematical model was used to clarify the contribution of the droplet surface modulation in different effects that present during the fuel ignition. It was shown that ignition delay time is decreased by up to 20% with growth of number of pores and particularly with growth of the specific surface of the droplet (by 10–20% and more). The maximal combustion temperature at the droplet center was slightly decreased after the introduction of the macro-pores. The recommendations for modification of the industrial power units to optimized ignition regime were presented.
Alexander Korotkikh, a professor at the Department of Nuclear and Thermal Power Plants, et al.
Journal: Combustion and Flame (IF 4.168; Q1).
The paper presents the results of measurement of the burning rate of aluminized composite solid propellants (CSPs) and parameters of sampled condensed combustion products including their particle size distribution, chemical and phase composition. Effect of ultra-fine iron and amorphous boron additives in CSP formulations based on AP, butadiene rubber and Alex (2 wt. %) on the combustion characteristics was studied. The sampled particles of condensed combustion products (CCPs) were classified as oxide particles (less than 55 µm) and agglomerate particles (up to 500 µm). The CCPs particles were subjected to morphological, particle size, chemical and phase analyses. It was found that partial replacement of Alex by 2 wt. % of iron in CSP leads to 1.3-1.4 fold increase in the burning rate in the pressure range of 2.2-7.5 MPa. At the same time the agglomeration of metal fuel is slightly increased: the mean diameter of agglomerate particles in CCPs is increased up to 1.2 fold and their content is increased up to 1.4 fold. The content and mean diameter of oxide particles in CCPs are reduced by 16 % and 13 %, respectively. Upon partial replacement of Alex by 2 wt. % of boron the burning rate is practically unchanged as compared with that for basic propellant with Alex. However the agglomeration is significantly enhanced, which is manifested at the increase in the agglomerate particles content in CCPs by 1.8-2.2 times, increase by 1.6-1.7 times in the agglomerates mean diameter and increase in the unburned metal fraction in agglomerates by 1.6-1.9 times. The content and the mean diameter of the oxide particles are reduced more significantly than in the case of iron introduction, namely, by 20-30 % and 30-40 %, respectively.
Semen Syrodoy, a senior lecturer at the Department of Theoretical and Industrial Thermal Engineering, Geniy Kuznetsov, head of the Department of Theoretical and Industrial Thermal Engineering, Arkady Zakharevich, an associate professor of the Department of Theoretical and Industrial Thermal Engineering, Nadezhda Gutareva, an associate professor at the Department of Foreign Languages, the Institute of Natural Resources, et al.
Journal: Combustion and Flame (IF 4.168; Q1)
The results of the experimental and numerical study of the coal–water fuel particles ignition (CWF) have been given, where the thermal properties (thermal conductivity (λ), heat capacity (C), density (ρ)) have been calculated using the different mathematical models. The heterogeneity and porosity of the structure of CWF have been taken into account in calculating λ, C and ρ. The influence of the shape, configuration and size of the pores on the thermal characteristics of coal–water fuel has been analyzed. It has been established that the effective thermal conductivity (λeff) is changed when there are the different ways of describing the thermophysical properties. It has been shown that increasing porosity (mp) of fuel during thermal decomposition affects λeff (or leads to the higher values of the effective coefficient of thermal conductivity, or to its decrease).
The set of the core processes of heat and mass transfer (thermal conductivity, filtration of water vapor, ignition) has been taken into account when conducting mathematical modeling. It has been carried out with taking into account the intense physicochemical (thermal decomposition of the organic part of the fuel, thermochemical interaction of water vapor and carbon coke) and phase (evaporation of water) transformations together in the WCF particle in the conditions of high temperature heating.
According to the results of the mathematical modeling the delay time of ignition of the coal–water fuel particles has been calculated. The “influence” of the ways of describing the thermal characteristics of CWF has been shown, which can be changed in the process of temperature increase on the delay time of ignition. It has been established that even if the maximum possible change of the coefficient of thermal conductivity (depending on the model λeff) deviation of the ignition delay time from the average values does not exceed 13%.
Dmitri Glushkov, an associate professor at the Department of Heat and Power Process Automation, Geniy Kuznetsov, head of the Department of Theoretical and Industrial Thermal Engineering, Pavel Strizhak, head of the Department of Heat and Power Process Automation.
Journal: Fuel Processing Technology (IF 3.847; Q1)
This paper examines ignition features of coal–water slurry containing petrochemicals (CWSP). Fuel slurry composition is based on a filter cake (typical processing waste) of coal (grade K), water, scavenged turbine oil, and plasticizer. The novelty of this paper is that it indicates a joint influence of several droplets on the CWSP ignition characteristics in an oxidizer flow (air). Its temperature and velocity vary in the range of 400–1200 K and 0.5–5 m/s. These ranges are chosen so as to yield optimal results that can be used in various fuel technologies and waste recycling. The study examines the cases of two, three, four, and five droplets. It is considered that droplets are arranged differently relative to each other (in parallel, in series, and in rhomb) in the oxidizer flow. The distances between droplets are also different; here, they vary from 0.5 mm to 1.5 mm. The diameter of each droplet is about 1 mm. The study specifies the ignition delay time for CWSP. Special facilities, such as high-speed cameras, cross-correlation systems, a hollow glass cylinder (representing a combustion chamber), are used to monitor the basic parameters of ignition. Tema Automotive and Actual Flow software allow processing of the experimental results. Experiments demonstrate that the local sources of heterogeneous combustion are formed when CWSP droplets are burning. Such formation is characterized by some features, since droplets are spaced differently in the group relative to the oxidizer flow. Finally, the paper discusses the joint influence of neighboring droplets on the conditions and characteristics of their sustainable combustion.
Roman Tabakaev, a research fellow at the Department of Steam Generating Machinery Engineering, Ivan Shanenkov, an assistant at the Department of Energy Supply of Industrial Enterprises, Alexander Kazakov, an associate professor at the Department of Steam Generating Machinery Engineering, Alexander Zavorin, head of the Department of Steam Generating Machinery Engineering.
Journal: Journal of Analytical and Applied Pyrolysis (IF 3.652; Q1)
Article: Since the reserves of fossil fuels are gradually exhausting, the biomass inclusion in the energy balance is becoming an urgent issue and a major field for researchers. However, such biomass characteristics as high moisture content, low calorific value, friability, stickiness and others lead to the high operating costs for burning. Thus, biomass pre-processing is required to improve its properties. This work shows the results obtained through the development and substantiation of the parameters of the biomass processing technology in a high-calorie solid fuel for boiler units. Chips from a mixture of Siberian wood (birch, pine, and aspen) and peat of Kandinsky deposit were used as biomass sources. Thermal processing (low-temperature pyrolysis) allows increasing the calorific value of the updated raw materials and obtaining the basis for the binder. Liquid pyrolysis products together with dextrin were used for molding solid composite fuel in the form of pellets and briquettes. These solid fuels had lower heating values of 29.1 MJ/kg (wood chips) and 20.9 MJ/kg (peat), which is superior to most types of fuel briquettes and pellets and comparable to the highest-quality fossil fuels.
Space Materials Science
Ramasubbu Sunder, a professor at the Department of Materials Science, Anton Biakov, an engineer at the Department of Materials Science in Mechanical Engineering, Alexander Eremin, an engineer at the Department of Materials Science in Mechanical Engineering, Sergey Panin, head of the Department of Materials Science in Mechanical Engineering.
Journal: International Journal of Fatigue (IF 2.162; Q1)
Fatigue crack growth tests were performed on an Al-Cu alloy under specially designed load sequences with a periodic overload cycle. These overloads were either immediately followed by or preceded by underloads of controlled magnitude. Baseline loading magnitude was designed to induce near-threshold conditions well below the Paris Regime. The fatigue fracture surfaces obtained from the tests were subject to fractographic analysis. The study shows that irrespective of their magnitude, underloads preceding tensile overloads do not affect crack growth rate after the overload. However, if the underload follows an overload, it carries a deleterious effect on retardation, whose magnitude is determined by the extent to which the underload drops below baseline cycling level. In either case, observed effects do not seem to have anything to with crack closure, but rather, are attributable to the effect of underloads on near-tip residual stress during baseline cycling that in turn controls threshold stress intensity range. Post-overload crack closure is reduced by crack-tip blunting, but rapidly recovers.
Unconventional Natural Resources
Natalia Belinskaya, an assistant at the Department of Chemical Engineering of Fuel and Chemical Cybernetics, Emilia Ivanchina, a professor at the Department of Chemical Engineering of Fuel and Chemical Cybernetics, Elena Ivashkina, a professor at the Department of Chemical Engineering of Fuel and Chemical Cybernetics et al.
Journal: Current Organic Synthesis (IF 2.05; Q3)
On the base of thermodynamic analysis, which was performed using the method of quantum chemistry, the influence of hydrocarbon structure and length of the carbon chain on the reactiveness was investigated. By solving the reverse kinetic problem, using the experimental data from the industrial plant, kinetic dependences of stages of diesel fuel synthesis were established. Using the developed model, the effect of process parameters on the composition of the product was investigated.
Bogdanchikova N. E. (h-index: 29), Prati L. (h-index: 45), Villa A. (h-index: 33), Alexey Pestryakov, head of the Department of Physical and Analytical Chemistry, Farias M. (h-index: 22), et al.
Journal: Current Organic Synthesis (IF 2.05; Q3)
It was shown that, depending on the preparation method, the activity of Au supported on oxide supports can become reversed. For deposition-precipitation method Au/Al2O3 is more active than Au/MgO while for sol immobilization, the contrary occurs and Au/MgO is more active than Au/Al2O3. Activities of Au catalysts supported on MgAl2O4 spinel are high and close to each other for catalysts prepared by both methods. It is suggested that Au particle size and interaction of Au with support are activity determining parameters, while gold content do not play a significant role. This study gets an insight on the importance of the direct contact between the support and the gold particle.