Issue 2, 2025
Numerical models of nonlinear acoustic waves propagation in problems of medical ultrasound and in some applications of aero- and underwater acoustics
Numerical models of nonlinear acoustic waves propagation in problems of medical ultrasound and in some applications of aero- and underwater acoustics
P. V. Yuldashev$^1$, O. A. Sapozhnikov$^3$, M. M. Karzova$^1$, S. A. Tsysar$^2$, A. V. Kvashennikova$^3$, E. O. Konnova$^1$, V. A. Khokhlova$^3$
The paper considers numerical algorithms used to solve one-way wave propagation equations of nonlinear acoustics, such as the Burgers equation, the Khokhlov-Zabolotskaya-Kuznetsov (KZK) equation, and the Westervelt equation. The main results obtained using the developed numerical models in problems of medical ultrasound, in nonlinear aeroacoustics, and in the analysis of nonlinear interactions of intense pump waves in a parametric antenna created in the field of an underwater transducer are presented. The generalization of one-way models to the case of the presence of inhomogeneities of the propagation medium using wide-angle parabolic approximation methods in three-dimensional problems is discussed.
Show AbstractSimple finite-dimensional model of the metastable state
Simple finite-dimensional model of the metastable state
A. I. Dubikovsky, P. K. Silaev
We have constructed an approximate analytical solution of the spectral problem for a finite-dimensional matrix of a special kind, which turns out to be a very simple and quite satisfactory model of the metastable state. Most of the characteristic properties of the metastable state are reproduced: line shape, decay dynamics, and density of states. The correctness of the approximate analytical solution was verified by direct numerical calculations. The proposed model is a finite-dimensional analog of the Fano formalism.
Show AbstractTriangle Meshes Generation Using Potential Energy Minimization Method
Triangle Meshes Generation Using Potential Energy Minimization Method
K. A. Novikov$^1$, D. A. Konyaev$^1$, T. A. Novikova$^2$
An analysis of the molecular dynamic method of node placement at the construction of unstructured grids is presented. The method of its improvement is considered. An energy approach to the problem of placing knots of a triangular grid on a surface is proposed, which is based on the idea of finding minimum of potential energy of a system of charges by the gradient descent method.
Show AbstractElectromagnetic form factors of the deuteron in the dibaryon model of NN interaction
Electromagnetic form factors of the deuteron in the dibaryon model of NN interaction
M. N. Platonova$^1$, I. T. Obukhovsky$^1$
The electromagnetic form factors of the deuteron have been calculated within the dibaryon model for nuclear forces, which is based on the resonance mechanism of formation of a six-quark bag (dibaryon) in a NN collision. The calculations take into account both the single-nucleon currents (impulse approximation) and additional contributions induced by the formation of an intermediate dibaryon. For the calculations of form factors, two versions of the dibaryon model, of 2002 and 2022, have been used. It is shown that both versions of the model reproduce experimental data well for all three deuteron form factors in the region of transferred momenta Q < 0.8 GeV/c. At higher values of Q, the predictions of different versions of the model deviate from each other, with one of them (2002) better describing the magnetic form factor, and the other (2022) - the charge one. Possible reasons for the discrepancy found between the theoretical calculations and experimental data for large momentum transfers are discussed.
Show AbstractMeasurement of the VVER-1000 reactor power output by its antineutrino fluх from the core
Measurement of the VVER-1000 reactor power output by its antineutrino fluх from the core
A. V. Abramov$^3$, R. R. Alyev$^2$, M. B. Gromov$^{1,4}$, I. N. Zhutikov$^{3,5}$, S. M. Kiselev$^2$, A. V. Konstantinov$^3$, D. S. Kuznetsov$^3$, E. A. Litvinovich$^{3,5}$, I. N. Machulin$^{3,5}$, I. N. Machulin$^3$, A. M. Nemeryuk$^3$, R. R. Nugmanov$^3$, A. Yu. Oralbaev$^{3,5}$, D. V. Popov$^{3,5}$, A. A. Rastimeshin$^{3,5}$, M. D. Skorokhvatov$^3$, M. A. Strizh$^{1,3}$, S. V. Sukhotin$^3$, A. A. Hvatov, A. S. Chepurnov$^1$, D. A. Chmykhalo$^{3,5}$, A. V. Etenko$^{3,5}$
In this paper we present the results of the measurements of the industrial nuclear reactor power output by its antineutrino flux from the core. The measurements were carried out with the iDREAM detector at a distance of 19.5 m from the center of the core of the VVER-1000 reactor at the Kalinin NPP (Russia). Estimates of the sensitivity of the iDREAM detector to changes in reactor power were obtained for 2-, 4-, and 6-hour intervals of collecting data on antineutrino interactions.
Show AbstractSearching for bosonic dark matter with the iDREAM neutrino detector at Kalinin Nuclear Power Plant
Searching for bosonic dark matter with the iDREAM neutrino detector at Kalinin Nuclear Power Plant
A. V. Abramov$^1$, R. R. Alyev$^2$, M. B. Gromov$^{3,4}$, I. N. Zhutikov$^{1,5}$, K. K. Kiselev$^5$, S. M. Kiselev$^2$, A. V. Konstantinov$^1$, D. S. Kuznetsov$^1$, E. A. Litvinovich$^{1,5}$, I. N. Machulin$^{1,5}$, A. E. Murchenko$^1$, A. M. Nemeryuk$^1$, R. R. Nugmanov$^1$, A. Yu. Oralbaev$^{1,5}$, D. V. Popov$^{1,5}$, A. A. Rastimeshin$^{1,5}$, M. A. Strizh$^1$, V. A. Khvatov$^2$, A. S. Chepurnov$^3$, D. A. Chmykhalo$^{1,5}$, A. V. Etenko$^{1,5}$
Bosonic dark matter search results obtained with the iDREAM neutrino detector at Kalinin Nuclear Power Plant are presented. Using data on composition of the active core of VVER-1000 nuclear reactor and fission fractions of primary fissile isotopes, the γ-radiation energy spectrum in the active core is calculated. Assuming that the dark bosons can be produced in the active core via γ-scattering on electrons and can be detected via an inverse process inside the iDREAM detector, experimental bounds on the coupling constant gX between the dark boson and Standard Model charged leptons are derived.
Show AbstractAnalysis of cell death and proliferative activity of cell cultures under proton irradiation in flash mode
Analysis of cell death and proliferative activity of cell cultures under proton irradiation in flash mode
V. V. Martynova, S. V. Akulinichev, I. A. Yakovlev
The study of biological effects of accelerated protons with ultra-high dose rate in and outside the Bragg peak on tumor and normal cell lines is necessary for understanding the consequences of this effect and choosing optimal doses and modes for further use in tumor radiotherapy. In this work, human colon adenocarcinoma cells (HT-29) and normal mesenchymal stem cells (ADSC) of human adipose tissue - fibroblasts were irradiated. Irradiation was carried out using a high-current linear proton accelerator of the INR RAS, which allows varying the energy in the range of 70-230 MeV. The dose was delivered in three different modes: conventional mode (dose rate Ḋ < 3 Gy/s), flash mode (Ḋ ~ 100 Gy/s) and single-pulse flash mode (Ḋ > 104 Gy/s) in the modified Bragg peak region. To analyze cell death, staining with propidium iodide and annexin was performed. For proliferative potential, the EdU test was reproduced. After 24 h, an increase in the number of apoptotic HT-29 cells was detected in all modes, for fibroblasts, an increase in the number of necrotic cells was observed with the conventional irradiation mode and a higher dose compared to other modes. After 48 h, with all irradiation modes, a tendency towards a decrease in the number of necrotic HT-29 cells depending on the dose was observed with the flash/splash modes and a low level of such for fibroblasts. The number of DNA-synthesizing cells by 120 h significantly decreased with all doses and irradiation modes. The curves for the flash and splash irradiation modes were almost parallel. Further studies are needed using wider ranges of cell lines and doses.
Show AbstractReservoir network based on single impurity atoms in silicon
Reservoir network based on single impurity atoms in silicon
A. S. Andreeva$^1$, A. S. Trifonov$^1$, V. V. Shorokhov$^1$, D. E. Presnov$^1$, O. V. Snigirev$^1$, V. A. Krupenin$^1$
This work is aimed at solving the problem of experimental implementation and study of single-electron reservoir networks with As impurity atoms in a quasi-two-dimensional near-surface layer of a solid-state matrix based on silicon-on-insulator (SOI) material. The study of electron transport in the fabricated experimental structures showed the presence of horizontal sections of the Coulomb blockade on the current-voltage characteristics (CVC), typical of single-electron transport. The shape of the recorded CVC between a pair of selected control electrodes of the reservoir network significantly depended on the potentials of the remaining surrounding electrodes, which changed the structure of the conducting channels passing through the impurity centers. Restructuring the control voltages, using the internal nonlinearity of the system of disordered single As impurity atoms, which has a colossal state space, made it possible to demonstrate the possibility of implementing a tunable nanoscale current switch and the logical functions "NOT", "AND", "OR" in a single-electron reservoir network. To find the configuration of the reservoir network necessary for the implementation of functional elements, a vector tuning method was used.
Show AbstractReconstruction of a photonic crystal structure from a given phase response
Reconstruction of a photonic crystal structure from a given phase response
P. S. Emeliantsev$^1$, S. E. Svyakhovskiy$^1$
We present a method for designing one-dimensional photonic structures of phase response with predefined shapes and features. An algorithm for constructing such photonic crystal structures has been developed, and numerical modeling of structures' phase and spectral responses has been performed.
Show AbstractPeculiarities of amplitude characteristics and bias in a three-frequency Zeeman ring laser
Peculiarities of amplitude characteristics and bias in a three-frequency Zeeman ring laser
M. E. Grushin$^1$, E. G. Lariontsev$^2$, I. I. Savel'ev$^1$, E. V. Soukhov$^1$
Characteristics of a Zeeman ring laser (ZRL) have been investigated theoretically and experimentally in the conditions of a two- and three-frequency generation. A two-frequency ZRL operates on the counterpropagating waves of a single mode. In a three-frequency ZRL, in addition to these waves, a running wave of the neighbor longitudinal mode (a third frequency) is excited. It is shown that an excitement of the third frequency leads to the appearance of kinks in the dependence of the output intensity on the frequency detuning from the gain-line center. A bias appearing in the presence of a magnetic field in the active medium changes due to a three-frequency interaction. Interaction of the excited modes is very sensitive to the value of the isotope shift between Ne20 and Ne22. There is a large spread of the measured earlier values of the shift. The results obtained in this study allow one to choose the most appropriate value of the isotope shift.
Show AbstractResistive gas sensor based on mesoporous MoS2 films
Resistive gas sensor based on mesoporous MoS2 films
A. B. Loginov$^1$, M. M. Kuvatov$^1$, I. V. Sapkov$^1$, R. R. Ismagilov$^1$, V. I. Kleshch$^1$, A. N. Obraztsov$^1$
Semiconducting mesoporous films with high specific surface area are of great interest for development of gaseous media sensors. In this work such sensors were fabricated using material synthesized on different substrates via chemical reaction between gaseous H2S and Mo vapor obtained by thermal evaporation. By X-ray photoelectron spectroscopy chemical composition of MoS2 was confirmed. By the use of scanning electron microscopy it was revealed that deposited on different substrates films consist of an array of crystallites of nanometer thickness and transversal dimensions of several hundreds of nanometers. MoS2 crystallites are oriented predominantly perpendicularly to substrate surface and spaced by distance of several dozens of nanometers. It was discovered that electrical resistivity of MoS2 decrease with increasing of air humidity and NH3 vapor concentration. Response profile has exponential time dependence and has two time constants. Characteristic rise times for NH3 vapor case are 0.9 and 17 s, and fall times – 1.2 and 29 s. In case of H2S vapor rise times are 4 and 45 s, and fall times – 1.25 and 42 s. Mechanisms of increasing in electrical conductivity with increasing air humidity and NH3 vapor concentrations are discussed.
Show AbstractFeSe₀.₅Te₀.₅ films on glass with CeO₂ doping
FeSe₀.₅Te₀.₅ films on glass with CeO₂ doping
A. V. Petrov$^1$, O. V. Snigirev$^1$, Y. A. Ovchenkov$^1$, Yu. V. Blinova$^2$, N. V. Porokhov$^3$, A. R. Shevchenko$^3$, D. A. Chareev$^{4,5}$, A. G. Maresov$^1$
Deposition modes for thin films of FeSe0.5Te0.5 on an amorphous substrate made of K-208 glass, containing cerium oxide (CeO2), were found. The transition temperature of the film, TC = 9.5 K, to the superconducting state was higher than that on borosilicate glass from Fischer Scientific, which does not contain CeO2, but lower than the superconducting transition temperature of the target, TC(M) = 14 K. This is the opposite of the commonly known behavior of thin films of the FeSe and FeSexTe1−x family on crystalline substrates. From the measurement results, the vortex activation energy (U), the critical current density (jC), the upper critical field (HC2), and the irreversibility field (Hirr) were estimated.
Show AbstractAtomic mechanism of transformation between bcc and hcp phases in zirconium under pressure
Atomic mechanism of transformation between bcc and hcp phases in zirconium under pressure
R. I. Sinyakov, M. P. Belov
Using first-principles crystal energy calculation methods, the atomic mechanism of transformation between the bcc ( ) and hcp ( ) phases of zirconium at low temperatures was studied. An accurate two-parameter geometric method has been developed to describe the transformation of a crystal lattice according to the Burgers mechanism. The presented description method takes into account changes in the atomic volume and shape of the crystal lattice during transformation. Using the proposed description of the transformation, the potential energy surfaces of zirconium were constructed during the bcc-hcp transformation in the pressure range from 0 GPa to 25 GPa with a step of 5 GPa. The gradient descent method was used to determine minimum energy paths along potential energy surfaces. Analysis of the results obtained showed a strong dependence of the shape of the energy surfaces and the path of minimum energy on pressure. When the pressure increases to 25 GPa, the shape of the potential energy surface of zirconium changes critically, and a structure appears on the surface with an energy lower than that of the hcp by 10.5 meV. A comparison of the calculation results made using the developed two-parameter method for describing the transformation with oneparameter analogues from the literature showed the inconsistency of the latter as a tool for studying the atomic mechanisms of phase transitions.
Show AbstractStudy of single antigen-antibody interactions on the silicon surface in biosensors based on field-effect transistors with a nanowire channel
Study of single antigen-antibody interactions on the silicon surface in biosensors based on field-effect transistors with a nanowire channel
D. E. Presnov$^1$, G. V. Presnova$^2$, I. I. Tsiniaikin$^1$, G. V. Nibudin$^1$, O. V. Snigirev$^1$, A. S. Trifonov$^1$, M. M. Ulyashova$^2$, V. A. Krupenin$^1$, M. Yu. Rubtsova$^2$
Here we report a study of single interactions of antibodies with prostate-specific antigen (PSA) on the surface of pure silicon modified with 5 nm gold nanoparticles to create highly sensitive biosensors based on field-effect transistors with a silicon nanowire channel (FET). The method of digital registration of immune complexes by the scanning electron microscopy technique with gold nanoparticles 25 nm in diameter as a visualizing label of antibodies was used. A special algorithm was developed to calculate the density of nanoparticles on the silicon surface. To study the covalent immobilization of antibodies, different methods of chemical modification of silicon using (3-glycidoxypropyltrimethoxysilane (GOPS), 3-mercaptopropyltrimethoxysilane (GOPS-SH), and 3-aminopropyltriethoxysilane (APTES), bifunctional reagents and polyethyleneglycol were used. It was shown that chemical modification methods using GOPS are characterized by a lower detection limit of PSA, a biomarker of prostate tumors. The structures of biosensors based on field-effect transistors with nanowires channels, with surfaces, modified by two different methods using GOPS, were fabricated, and their sensitivity to pH was studied. It was shown that the modification method using GOPS-SH is characterized by a maximum pH sensitivity of 70 mV/pH and is the most promising for the creation of highly sensitive biosensors for determination of biomarkers.
Show AbstractStudy of collagen-induced platelet aggregation using low angle light scattering method
Study of collagen-induced platelet aggregation using low angle light scattering method
G. S. Svidelskaya$^{1,2,3}$, E. N. Bruskova$^4$, A. A. Ignatova$^3$, A. A. Filkova$^3$, P. A. Zharkov$^3$, I. V. Mindukshev, S. P. Gambaryan, M. A. Panteleev$^{1,2,3}$
Assessing platelet function is a key to diagnosing bleeding disorders and monitoring the effectiveness of antiplatelet drugs. Recently a method for assessing platelet aggregation based on the phenomenon of low angle light scattering was developed. Measurements are carried out in an medium with a known pH value and calcium concentration. The aim of this work was to study the influence of preanalytical and analytical variables, as well as to compare the results with the method of light transmission aggregometry, already widely used in clinical practice. It was revealed that transporting the sample by car for two hours does not affect the parameters of collagen-induced aggregation. The low angle light scattering method for measuring collagen-induced platelet aggregation has been shown to have good precision under repeatable conditions and was short-term reproducible. The aggregation parameters obtained by low angle light scattering directly correlate with the aggregation parameters measured by transmission aggregometry. Accelerating role of released adenosine diphosphate on collagen-induced platelet aggregation was shown.
Show AbstractNumerical model of cosmic ray propagation in an anisotropic magnetic field of the galaxy
Numerical model of cosmic ray propagation in an anisotropic magnetic field of the galaxy
V. D. Borisov$^1$, Yu. O. Vladimir$^2$, I. A. Kudryashov$^3$
The task of diffusive propagation of cosmic rays (CR) with a general tensor in a model homogeneous magnetic field of the galaxy has been solved in the work, and its stability has been investigated. An algorithm for generating stencils of second-order accuracy difference schemes for a three-dimensional differential equation with tensor components was implemented. This method was applied to solve the problem of diffusive propagation of CR. The work demonstrates the fundamental possibility of determining the energy spectra of CR in various regions of the galaxy, where the distribution of CR sources and the structure of the magnetic field are free parameters.
Show AbstractLinear approximation in the two-planet problem with arbitrary orbital inclination. Evolution of the TOI-1130 system
Linear approximation in the two-planet problem with arbitrary orbital inclination. Evolution of the TOI-1130 system
B. P. Kondratyev$^{1,2}$, V. S. Kornoukhov$^{1,2}$, E. N. Kireeva
A new version of the two-planet problem is formulated and investigated, where orbits with small eccentricities and mutual inclinations can have an arbitrary orientation relative to the main (picture) plane. The model allows studying a wide class of exoplanetary systems with an orbital inclination angle different from To derive the equations of the secular evolution of orbits, the mutual gravitational energy of Gaussian rings obtained as a series accurate to terms of the second order of smallness is used instead of the classical perturbation function. A method has been developed in which a vector perpendicular to the plane of the orbit and Poincaré variables are introduced to describe each orbit instead of Lagrange elements without loss of information. A closed system of 10 differential equations is obtained and solved analytically for these unknowns. The method is applied to study the secular evolution of the TOI-1130 exoplanetary system.
Show AbstractTwo Supernovae in NGC 4666: ASASSN-14lp and 2019yvr
Two Supernovae in NGC 4666: ASASSN-14lp and 2019yvr
D. Yu. Tsvetkov$^1$, N. N. Pavlyuk$^1$, N. P. Ikonnikova$^1$, M. A. Burlak$^1$, A. A. Belinski$^1$, A. V. Dodin$^1$, S. A. Potanin$^1$, N. I. Shatsky$^1$, I. M. Volkov$^1$, P. V. Baklanov$^{1,2,3}$, M. G. Ushakova$^{1,2}$, V. A. Echeistov$^1$, V. M. Lipunov$^1$
We present the results of photometric observations for two Supernovae in NGC\,4666: SN Ia ASASSN-14lp and SN Ib 2019yvr, and also spectroscopic observations for SN\,2019yvr. The light curves are constructed and their main parameters are derived. Supernova ASASSN-14lp is a typical object of class Ia with low rate of brightness decline and large interstellar extinction. An estimate of disance to the galaxy NGC\,4666 is obtained using the dependence of maximum luminosity of SNe Ia on the parameters of the light curves. The spectra of SN\,2019yvr near maximum light, the maximum luminosity and the shape of the light curves during first 90 days after maximum revealed characteristics of typical SN Ib, with interstellar extinction larger than for ASASSN-14lp. The decrease of the rate of brightness decline at phase about 90 days is found. We performed modeling of the light curves with STELLA code, the physical parameters of the optimal model are presented. The agreement of the model with observations breaks after $\sim$40 days past maximum, the model with extra source of energy from magnetar rotation slowdown is proposed to account for this divergence.
Show AbstractDetection and evaluation of Slichter 1S1 mode based on Baksan laser interferometer strain data after the 2011 Tohoku earthquake
Detection and evaluation of Slichter 1S1 mode based on Baksan laser interferometer strain data after the 2011 Tohoku earthquake
M. P. Vinogradov$^1$, V. K. Milyukov$^1$, A. V. Myasnikov$^1$, A. F. Yanin$^2$
The 1S1 mode of the Earth's free oscillations (Slichter mode) arises from the oscillations of the Earth's inner solid core relative to the outer liquid core. The search and evaluation of the Slichter mode after the 2011 Tohoku earthquake using data from the Baksan laser interferometer-strainmeter are presented in this paper. An algorithm based on the Maximum Likelihood Method (MLM) was used to search and for estimate the mode parameters. The most likely estimates of the degenerate mode frequency and its splitting parameters associated with the presence of Slichter mode excitation in the studied data are obtained. An estimate of the density jump between the inner and outer core of the Earth is obtained for the found mode periods. For the first time, the potential capabilities of the Baksan stainmeter and the superconducting gravimeters of the IGETS network have been compared for the problem of Slichter mode observation after the same earthquake. The similarity of the found estimate of the mode from strain observations with the previously obtained estimate from gravimetric observations, as well as with the theoretical value from the PREM model, is noted.
Show AbstractReproduction of hydrothermodynamic characteristics of the Russian Western Arctic Seas with assimilation of sea surface temperature and sea ice concentration data
Reproduction of hydrothermodynamic characteristics of the Russian Western Arctic Seas with assimilation of sea surface temperature and sea ice concentration data
I. I. Panasenkova$^{1,2}$, V. V. Fomin$^{1,2,3}$, N. A. Diansky$^{1,3,4}$
Accurate forecasting of meteorological, hydrothermodynamic and ice characteristics in the Russian Western Arctic Seas using atmospheric circulation, marine circulation and sea ice models is currently impossible without assimilation of observational data. It improves the quality of the initial model state including hydrophysical and ice characteristics for carrying out forecasts. In this paper we present a technique for assimilation of sea surface temperature (SST) and sea ice concentration (SIC) satellite data in the INMOM marine circulation model using the DART (Data Assimilation Research Testbed) software with an assessment of the correctness of the assimilation algorithm used. A comparative analysis of the forecasts’ accuracy of the hydrothermodynamics reproduction with the assimilation of SST and SIC satellite data and without assimilation is carried out. It is shown that satellite data assimilation reduces the RMSE of the forecasts and observational data by ~80% for SST and by 60–80% for SIC compared to the simulation without assimilation. Temporal variability of the RMSE in the SST and SIC forecasts shows that their largest errors are observed during the periods of intense heating of the upper sea layer and ice melting. The importance of joint SST and SIC data assimilation is noted: a more accurate reproduction of SST improves the accuracy of calculations of heat and salt fluxes at the ocean-ice boundary, which regulate the processes of thermal accretion/melting of ice, and, as a result, the reproduction of the ice area and its edge is improved. In turn, a more correct SIC calculation directly improves the accuracy of heat flux calculations at the water-air boundary and, thereby, SST improves.
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