Influence of hydrophobic dust particles on the parameters of wind waves in the generation zone
Influence of hydrophobic dust particles on the parameters of wind waves in the generation zone
I. N. Ivanova, O. N. Melnikova
The paper investigates the effect of a film of natural dust deposited from the air on the generation of gravitational-capillary wind waves with a length of λ<0.06 m. It is shown that with an increase in the deposition time of hydrophobic dust particles on the water surface, the contact wetting angle between the water surface and the hydrophobic particle increases, which indicates an increase in the surface tension coefficient. At the same time, the time of convergence of hydrophobic particles increases. It was found that with increasing film concentration for a given wind speed, the length of the wind wave in the generation zone decreases, and the steepness increases, which is associated with an increase in roughness and coefficient of friction at the interface. Nonlinear plane waves with a steepness of 0.13
On monitoring on the under-development $\gamma$source based on backward Compton scattering for photonuclear research at $E_{\gamma}$ ≲ 40 MeV
On monitoring on the under-development $\gamma$source based on backward Compton scattering for photonuclear research at $E_{\gamma}$ ≲ 40 MeV
S. S. Belyshev$^1$, V. V. Varlamov$^2$, D. L. Zavenovich$^3$, A. A. Kuznetsov$^{1,2}$, A. M. Lapik$^3$, A. L. Polonski$^3$, A. V. Rusakov$^3$, V. I. Shvedunov$^2$
Based on a comparison of the parameters of the projected $\gamma$-source from back Compton scattering and the known ways of monitoring the beams of $\gamma$-quanta themselves to monitor the intensity and energy spectrum of $\gamma$-quanta in their beams at this $\gamma$-source in photonuclear studies in the region from several MeV to ~40 MeV, a system of scintillation plastic and inorganic detectors, as well as a pair magnetic spectrometer, was proposed.
Show AbstractQuestions of mathematical modelling in the study of acid retardation on ion–exchange resins
Questions of mathematical modelling in the study of acid retardation on ion–exchange resins
M. A. Kaznacheev
In this paper, the chemical equilibrium of a multicomponent solution is considered in detail as part of a dynamic model of the acid retardation method. A detailed study of the chemical equilibrium, represented as a system of nonlinear equations, is a key step for building an effective dynamic model in the case of a multicomponent solution. This paper presents an algorithm for efficient calculation of chemical equilibrium using extractive phosphoric acid as an example. This algorithm can be used in a dynamic model to calculate chemical equilibrium at each point of the spatial grid and at each integration step. Moreover, for the concentrations of substances in the experiment on the purification of extractive phosphoric acid, it is shown that the nonlinear system of equations of chemical equilibrium allows one to obtain simple algebraic relations for the connection of the concentration of molecules of the substance with the total concentration of substances of all elements in solution with good accuracy. In addition, it was shown that for each metal, only one type of salt sorption can be considered due to the low concentration of other types, which makes it possible to reduce the number of differential equations in the dynamic model of the acid retardation method.
Show AbstractGap recovery in the time series of CO$_2$ concentration and air temperature using methods of mathematical statistics
Gap recovery in the time series of CO$_2$ concentration and air temperature using methods of mathematical statistics
V. S. Aleshnovskii$^1$, A. V. Bezrukova$^2$, V. K. Avilov$^3$, V. A. Gazaryan$^{1,4}$, J. A. Kurbatova$^3$, O. A. Kuricheva$^3$, A. I. Chulichkov$^{1,5}$, N. E. Shapkina$^{1,6}$
The article is devoted to the problem of recovering gaps in the data series of experimental long-term continuous high-frequency observations of carbon dioxide concentration and air temperature. The study was carried out on the example of the results of observations of an automatic ecological and climatic station located in a tropical monsoon forest on the territory of south Vietnam (Dong Nai Nature Reserve). Omissions in the series of observations, as a rule, are random and are caused by technical malfunctions of the instrument base. Correctly recovered series of observations allow us to estimate the temporal variability of the observed parameters on different time scales. Within the framework of this study, options for recovering the continuity of time series based on the methods of mathematical statistics - autoregression (ARIMA) and the method of linear prediction were considered. A comparative analysis of the accuracy of restoring omissions by various methods is given.
Show AbstractOn the study of reaction yields of $^{13}$C($\gamma$, p)$^{12}$B, $^{14}$N($\gamma$, 2p)$^{12}$B, $^{14}$N($\gamma$, 2n)$^{12}$N through measurements of ($^{12}$B, $^{12}$N) activities with $\Delta E$-detector telescopes between electron accelerator pulses
On the study of reaction yields of $^{13}$C($\gamma$, p)$^{12}$B, $^{14}$N($\gamma$, 2p)$^{12}$B, $^{14}$N($\gamma$, 2n)$^{12}$N through measurements of ($^{12}$B, $^{12}$N) activities with $\Delta E$-detector telescopes between electron accelerator pulses
S. S. Belyshev$^1$, L. Z. Dzhilavyan$^2$, A. I. Karev$^3$, A. M. Lapik$^2$, A. L. Polonski$^2$, V. N. Ponomarev$^2$, A. V. Rusakov$^2$, A. A. Turinge$^2$
The possibilities are analyzed for studying the yields of reactions $^{13}$C($\gamma$, p)$^{12}$B, $^{14}$N($\gamma$, 2p)$^{12}$B, $^{14}$N($\gamma$, 2n)$^{12}$N by measuring the induced ($^{12}$B, $^{12}$N)-activity with telescopes of thin $\delta E$-detectors in time intervals between electron accelerator pulses. For production of ($^{12}$B, $^{12}$N)-nuclei and registration of their decay, estimates are given taking into account the parameters of the electron beam, Ta-radiator and irradiated targets made from graphite or NH$_4$NO$_3$, as well as the parameters of scintillation $\delta E$-detector telescopes made from thin plastic plates.
Show AbstractOn the probable interpretation of anticorrelation between the proton temperature and density in the solar wind
On the probable interpretation of anticorrelation between the proton temperature and density in the solar wind
Yu. V. Dumin$^1$, A. T. Lukashenko$^2$, L. M. Svirskaya$^3$
The anticorrelated distributions of temperature and density of protons are a well-known property of the solar wind. Nevertheless, it is unclear till now if they are formed by some kind of the universal physical mechanism? Unfortunately, a straightforward comparison of the characteristic relaxation times for temperature and density, on the one hand, and pressure, on the other hand, encounters the problem of inapplicability of the hydrodynamical approach in the situation when the free-path length of protons is considerably greater than the spatial scale of the structures under consideration. To resolve this problem, some kinds of the MHD turbulence - reducing the effective free paths - are usually assumed. In the present paper, we use an alternative approach based on the electrostatic (Langmuir) turbulence, described by the mathematical formalism of the spin-type Hamiltonians, which was actively discussed in the recent time in the literature on statistical physics. As follows from the corresponding calculations, formation of the anticorrelated distributions of temperature and density is a universal property of the strongly-nonequilibrium plasmas governed by the spin-type Hamiltonians when they gradually approach the thermodynamic equilibrium. So, just this phenomenon could be responsibly for the anticorrelations observed in the solar wind.
Show AbstractDynamics of passive admixture in surface and subsurface external deformation field above an ocean guyot
Dynamics of passive admixture in surface and subsurface external deformation field above an ocean guyot
M. V. Shatokhin$^1$, M. A. Sokolovskiy$^{1,2}$
Within the framework of a three-layer quasi-geostrophic model, a numerical study of the effect of an isolated submarine obstacle on the movement of surface and subsurface patches of a neutral admixture transfered by a vertically homogeneous zonal current was carried out. The possibility of partial capture of impurities by quasi-stationary topographic eddy in the vicinity of the submarine obstacle is shown. The role of the initial location (both horizontally and vertically) on the resulting pollution distribution pattern is revealed.
Show AbstractPhotoelectric charging of dust inprotoplanetary disks
Photoelectric charging of dust inprotoplanetary disks
T. I. Morozova, I. A. Kuznetsov
The process of ionization-recombination of gas and charging of dust particles under the action of X-rays under space plasma conditions is considered. The conditions are found when, as a result of exposure to radiation, dust particles in a protoplanetary disk can acquire a positive charge even with low gas ionization.
Show AbstractEvaluation of the asteroid material composition by reflectance spectra using meteorite analogues
Evaluation of the asteroid material composition by reflectance spectra using meteorite analogues
A. A. Savelova$^1$, V. V. Busarev$^{1,2}$, M. P. Shcherbina$^{1,2}$
The MATLAB program was developed to estimate composition of the asteroid material. The program models reflectance spectra of asteroids using reflectance spectra of meteorite analogues. Modeling results and estimation of the material composition for 10 asteroids (1 Ceres, 4 Vesta, 51 Nemausa, 65 Cybele, 102 Miriam, 250 Bettina, 266 Aline, 379 Huenna, 704 Interamnia, 1474 Beira) are discussed. A good agreement between the model spectra and the asteroids reflectance spectra is achieved for a number of asteroids (1 Ceres, 4 Vesta, 51 Nemausa, 250 Bettina, 704 Interamnia).
Show AbstractOptimization of near-field amplification at resonant light scattering by nanoparticles
Optimization of near-field amplification at resonant light scattering by nanoparticles
E. A. Trukhan
In the present work, expressions for the system parameters that realize the maximum of the scattered field in the Mie problem separately for metals and for dielectrics were obtained. For metals, the answer was obtained in the form of formulas, for dielectrics an algorithm that allows finding the coordinates of the maximum is presented. The behavior of the solution, applied to real substances (Al, Au, GaP), is considered. In the case of the metals under relatively low dissipation at the resonant frequency, it accurately points to the maximum, and as the dissipation increases, it points to the neighborhood of the maximum. For considered dielectrics it was shown that theoretically predicted maximums are unattainable due to the limited value of the refractive index of the substance, the reasons why the maximums exist despite the mentioned limitation. In particular, it was found that the wavelength of the incident radiation and the radius of the particle at the maxima for GaP coincide with the resonance value for the internal coefficients. It was the starting point of the present study. Obtained results show that it really provides a guideline for searching for the maximum of the field scattered by other dielectrics spherical particles with a relatively low refractive index.
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