Equations of state of a system of hard spheres in a reduced form
Equations of state of a system of hard spheres in a reduced form
P. N. Nikolaev
The equations of state are investigated for a system of hard spheres in the general quantum-mechanical case. The equations are presented in the reduced form. A comparison is made between the classical approximation, the semiclassical approximation with allowance for the first correction, and the cell-cluster expansion with allowance for three-particle clusters, inclusive. The cell-cluster expansion, as calculations show, is more efficient than the semiclassical approximation at high densities. It is shown that the density dependence in the caloric equation of state is significant, which is also preserved at high temperatures. In the general case, Joule's law does not hold for a system of hard spheres.
Show AbstractMulticircuit algorithm for the numerical solution of dynamic equations of the Vlasov-Darwin model
Multicircuit algorithm for the numerical solution of dynamic equations of the Vlasov-Darwin model
L. V. Borodachev, S. S. Annenkov
An approach to the optimization of the procedure for solving the equations of motion of particles of a discrete self-consistent model of a rarefied plasma based on the conjugation of dynamic schemes of different nature and computational properties is developed. The concept was algorithmically implemented and tested in mathematical modeling (using the PIC method) of the low-frequency kinetic Weibel instability. A significant reduction in the simulation time is shown when using the specified optimization technique in comparison with traditional computation based on only one (explicit or implicit) dynamic scheme. During computer experiments, the features of the behavior of the Weibel process at the stage of its saturation were revealed: the presence of damped low-frequency oscillations of the energy density of the magnetic field, the key parameter of instability.
Show AbstractIsospin splitting of the giant dipole resonance of atomic nuclei
Isospin splitting of the giant dipole resonance of atomic nuclei
I. M. Kapitonov
A simple estimate of the magnitude of the isospin splitting of the giant dipole resonance of atomic nuclei based on the concept of isospin symmetry of the nucleon-nucleon interaction is proposed. The obtained value of this splitting exceeds that traditionally used and better describes the experimental data for heavy nuclei.
Show AbstractMechanisms of interaction of the recharging plasma of an electric rocket engine with a radiation-charged dielectric surface
Mechanisms of interaction of the recharging plasma of an electric rocket engine with a radiation-charged dielectric surface
V. V. Valiullin, A. B. Nadiradze
In this paper, an attempt is made to develop a mathematical model of the interaction of the recharge (low-temperature) plasma of an electric rocket engine with a radiation-charged dielectric surface. This model is based on the well-known Fitting dielectric charging model, which describes the transport of non-equilibrium charge carriers in the near-surface layer of the dielectric. Possible physical processes of interaction of ions of the recharge plasma of an electric rocket engine with a radiation-charged dielectric surface are considered. It is shown that as a result of all these processes, holes are formed in the surface layer of the dielectric, on which the excess electrons are then relaxed.
Show AbstractInfluence of electron irradiation on the weight loss of a polymer composite and its contam-ination by gas release products of the optical glass surface
Influence of electron irradiation on the weight loss of a polymer composite and its contam-ination by gas release products of the optical glass surface
V. K. Meleshko, I. B. Vintaykin
In our work, we present the results of computational and experimental studies of the deposition of gas release products and radiation sputtering of a polymer composite material on the surface of cover glass samples of solar cell elements of a spacecraft under electron irradiation. K-208 glass samples were exposed to electrons with an energy of 30 keV and volatile products released from the EKOM-1 material when heated or under the action of electrons. The average electron flux density was cm-2 s-1, and the pressure in the vacuum chamber did not exceed Pa. Contamination of glass surfaces was controlled by measuring the transmittance of glass samples. The measurements were carried out on a «Cary 500» double-beam spectrophotometer in the range from 200 to 3300 nm with a spectral resolution of 2 nm. The measurement results showed that the largest decrease in the spectral transmittance of glass samples occurred after the simultaneous exposure to electron radiation and molecular fluxes. It was founded experimentally that irradiation of glass with electrons leads to an increase in the rate of accumulation of gas release products on it. This is due to the electrification of glass, which stimulates the deposition of radiation-ionized drugs on it - products of gas release and sputtering of EKOM-1.
Show AbstractGeneration of a sterilizing aerosol jet based on a gliding arc electric discharge
Generation of a sterilizing aerosol jet based on a gliding arc electric discharge
N. A. Aristova$^1$, A. A. Makarov$^2$, N. K. Gulko$^2$, I. P. Ivanova$^3$, I. M. Piskarev$^4$
The redox properties of liquids treated by a gliding arc electric discharge have been investigated. Distilled water and aqueous solutions of hydrogen peroxide with a concentration of 0.2 and 0.5% were used as working liquids. For the analysis, the sediment of aerosol mixture was caught. To determine the oxidation yield, the reaction of the sediment sample with a solution of Mohr's salt was used. The reduction yield was determined in the reaction with KMnO4. It was found that distilled water after passing through the discharge region acquires oxidizing properties. The oxidizing properties of hydrogen peroxide solutions are significantly enhanced. The oxidation yield is in the range of 2.2 – 4.8 (100 eV)1, the reduction yield is small, does not exceed 0.1 (100 eV)1. In the reaction with methyl orange (MO) concentration of 8 mg/L, the oxidizing ability of 3% hydrogen peroxide and the discharge-treated liquid are compared. It is shown that the liquid treated by the discharge almost completely oxidizes the MO solution, while 3% hydrogen peroxide has no effect on the MO. The main product formed under the action of a discharge in an aerosol flow is a complex that decomposes by ~95% within a time period of up to 3 days. Decomposition products are peroxynitrite and peroxynitrous acid. Their oxidative potential is much higher than that of chlorine and hydrogen peroxide. Therefore, the aerosol jet that has passed the gliding arc discharge area can be used as a strong disinfectant. This product is environmentally friendly, as active species decompose into water, nitrogen and oxygen.
Show AbstractGround State Multiplets with Seniority 2 in Neutron-rich Isotopes of Nickel
Ground State Multiplets with Seniority 2 in Neutron-rich Isotopes of Nickel
D. S. Zhulyaeva$^1$, S. V. Sidorov$^1$, T. Yu. Tretyakova$^{1,2}$
This paper considers neutron pairing interaction in even neutron-rich nickel isotopes $^{70-76}$Ni. The model of zero-range pairing forces is used to study the formation of ground state multiplets with seniority $\nu = 2$ as neutron $1g_{9/2}$ is gradually filled. Mass relation based on masses of four neighbouring nuclei is shown to yield satisfactory splitting of the ground state multiplets, as well as reproduce high-spin excited states in the isotopes under consideration.
Show AbstractSIMULATED ANALYSIS OF JET CHARGE IN PP-COLLISIONS AT THE LHC
SIMULATED ANALYSIS OF JET CHARGE IN PP-COLLISIONS AT THE LHC
I. A. Kochergin
The study of jets charge is necessary to refine the theory of fragmentation in quantum chromodynamics. Also, it can provide an opportunity for improving identification methods in high-energy particle collisions. At the same time, there is a lack of data on jets from heavy flavors. The paper analyzes the weighted charge of the jets from $b$-quarks depending on the method for determining the jet and the method for calculating the electric jets charge by software simulation using the Monte Carlo generator PYTHIA 8.2. Correlations have been established between the type of $B$-meson, type $b$ or $\bar{b}$ quark, and the electric charge of the jet at certain parameters of jet separation and calculation of its charge.
Show AbstractChange in glass K-208 morphology upon irradiation with medium-energy electrons
Change in glass K-208 morphology upon irradiation with medium-energy electrons
A. I. Ustinov
The results of AFM-researches of the glass K-208 samples are presented surfaces irradiated with electrons with energies of 20÷50 keV at a particle flux density φe = 3,0•1010 ÷ 1,0•1011 cm –2s–1. The samples were irradiated in a vacuum chamber at pressure of 10–4 Pa. Shown that changes in morphology of glass K-208 upon irradiation with medium-energy electrons occur due to electrostatic discharges, which resulted in forming microprotrusions and discharge channels, as well as due to forming of gas-filled bubbles.
Show AbstractStudy of the influence of dynamic and thermal characteristics of the atmospheric boundary layer on atmospheric air pollution in the Moscow metropolis
Study of the influence of dynamic and thermal characteristics of the atmospheric boundary layer on atmospheric air pollution in the Moscow metropolis
K. V. Rodina, E. G. Semutnikova
This article focuses on assessing the impact of wildfires and adverse weather conditions on air pollution in Moscow. The article examines in detail the case of aerosol pollution of the smoky atmosphere of the Moscow region in July 2016. The main indicators of wildfire investigated in this work are particulate matter PM10 and PM2.5. Calculations of the main statistical characteristics of PM10 and PM2.5 concentrations are presented: the average value, median and mode and pair correlation coefficients separately for PM10 and PM2.5 between different stations and between PM10 and PM2.5 at one station for the entire period of 2016 and 2018 as well as for the smoke period in July 2016 and the period with bad weather conditions in September 2018. The diurnal course under smoke is analyzed in comparison with the typical course in the warm period and in the bad weather conditions. Based on the intra-day dynamics of PM10 and PM2.5 concentrations in July 2016 and September 2018 the dependence of pollution on the thermal stratification of the atmospheric boundary layer is considered. The dependence of aerosol concentrations on the wind speed in the atmospheric boundary layer is analyzed.
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