Use of an assembly of two thermal conductometric sensors for detection of hydrogen emissions
Use of an assembly of two thermal conductometric sensors for detection of hydrogen emissions
A. E. Elyanov, V. M. Bocharnikov, V. V. Volodin, V. V. Golub, N. K. Dentsel
The work shows the possibility of using an assembly of two thermоconductometric sensors to simultaneously measure the flow speed of a gas mixture and the hydrogen content in it. A measurement concept has been proposed using one sensor located in the flow of the test gas, and a second one closed with a mesh cap, which reduces the dependence of the sensor readings on the flow speed. Test assemblies were manufactured and calibration experiments were carried out in the range of speeds from 0 to 1.84 m/s, hydrogen concentrations from 0 to 100 vol.% and absolute pressure from 0.1 to 5 atm. The results of calibration experiments show that from the signals from two sensors it is possible to unambiguously obtain the flow speed values and hydrogen content in the gas mixture at the location of the sensors. Formulas for converting signals into the required physical quantities are obtained. The assemblies are installed in a test container to study the mixing of hydrogen with air. The response time of the assembly to changes in hydrogen concentration does not exceed 1 s, which allows its use for signaling hydrogen emissions and studying the mixing of hydrogen with air. Graphs of the flow rate and concentration of hydrogen in the mixture versus time are presented.
Show AbstractRare decays of $D_s$ mesons into light pseudoscalar mesons
Rare decays of $D_s$ mesons into light pseudoscalar mesons
V. O. Galkin$^1$, I. S. Sukhanov$^{1,2}$
Rare decays of $D_s$ mesons into pseudoscalar mesons are studied in detail within the framework of the relativistic quark model based on the quasipotential approach and quantum chromodynamics. The form factors that parameterize the matrix elements of the weak current between meson states are calculated with consistent account of relativistic effects. Their dependence on the square of the transferred momentum is explicitly defined in the whole accessible kinematic region. The effects of electroweak physics at short distances and the contributions of intermediate resonances at large distances are taken into account using effective Wilson coefficients,. In the framework of the helicity formalism, differential decay rates and branching fraction are calculated. The obtained results are consistent with the existing upper experimental limits.
Show AbstractMathematical methods for analyzing the shape of time series and their applications to remote sensing of the Earth and atmosphere
Mathematical methods for analyzing the shape of time series and their applications to remote sensing of the Earth and atmosphere
A. F. Idrisov
The work is devoted to methods of time series analysis based on the theory of morphological analysis and measuring and computing systems developed at the Department of Mathematical Modeling and Computer Science of the Faculty of Physics of Lomonosov Moscow State University. Modern relevant methods of time series analysis have been studied. A morphological filtering method is proposed to detect a trend in a time series. A computer experiment was conducted on real experimental data (temperature measurements in the city of Tver) using the above method. The results demonstrated the successful identification of the trend component of the time series. It is planned to develop new methods of time series analysis to solve a wider class of problems for a wider class of input data.
Show AbstractUltra-high energy cosmic rays: sources, acceleration processes and GZK phenomena
Ultra-high energy cosmic rays: sources, acceleration processes and GZK phenomena
P. V. Alexandrovna$^1$, T. I. Yurievicn$^2$
Ultra-high energy cosmic rays (UHECR) reach an energy of 1020 eV, which is a million times higher than the energy achieved in artificial particle accelerators. The arrival of high-energy particles from space occurs infrequently, so detectors with a large area are required to register such events. It is necessary to understand what known effects can accelerate and decelerate particles to such energies. The upper energy limit is the Greisen-Zatsepin-Kuzmin (GZK) effect. This process significantly limits the possible distance to sources, and it should lead to suppression of the high-energy part of the spectrum. This work analyzes the GZK effect for nuclei from hydrogen to iron
Show AbstractDevelopment of a digital version of a space debris recognition system based on artificial intelligence
Development of a digital version of a space debris recognition system based on artificial intelligence
A. V. Shavshin$^1$, V. V. Davydov$^1$, D. A. Boldarev$^2$, R. A. Dmitriev$^1$, D. Yu. Klimenko$^2$, A. A. Hudina$^2$
The relevance of developing a space debris recognition system based on artificial intelligence is substantiated. A digital version of a space debris recognition system based on artificial intelligence has been developed, which can serve as the basis for creating a full-fledged system. The development of artificial intelligence code, its training and testing on experimental data was carried out. It has been established that the created digital version of the space debris recognition system based on artificial intelligence has the potential for successful detection and classification of space debris in the orbit of planet Earth.
Show AbstractEffect of partial unitarity requirements on the accuracy of measurements of Wilson coefficients in the processes of three and four top quarks production
Effect of partial unitarity requirements on the accuracy of measurements of Wilson coefficients in the processes of three and four top quarks production
A. M. Aleshko, E. E. Boos, V. E. Bunichev, L. V. Dudko
The problem of violation of unitarity in the Effective Field Theory of Standard Model (SMEFT) when applied to the processes of three and four top quarks production for relevant efficient operators. Using the optical theorem, boundaries of areas corresponding to the condition of non-violation of partial unitarity were determined. It was shown, how these restrictions affect the accuracy of setting limits on the corresponding Wilson coefficients. It has been established that for the processes under study, the influence of unitary restrictions is noticeable and leads to a deterioration in the accuracy of setting the corresponding limits even at collision energies of 13 and 14 TeV.
Show AbstractInvestigation of the structure and phase composition of Cu-Si films obtained by ion beam sputtering
Investigation of the structure and phase composition of Cu-Si films obtained by ion beam sputtering
E. S. Kersnovsky, I. V. Polshin, K. A. Barkov, D. N. Nesterov, S. A. Ivkov, V. A. Terekhov, B. L. Agapov, A. V. Sitnikov
In this work, the structure, phase composition and electronic structure of Cu-Si films with different copper content (from 15 to 68 wt.%) obtained by ion beam sputtering were studied by X-ray diffraction and ultra-soft X-ray emission spectroscopy. It was found that when Cu-Si films have a low copper content (~15 wt.%), the phases of 𝝲-Cu5Si and amorphous silicon a-Si are formed. Increasing the Cu content to up to 68 wt.% leads to the formation of the phases 𝞰-Cu3Si and 𝞰''-Cu3Si, as well as partial oxidation of copper with the formation of Cu2O oxide, while significant changes in the electronic structure of the valence band are observed as a result of the interaction of copper d-electrons and silicon s,p-electrons. An increase in the copper content in the composition of Cu-Si films from ~15 wt.% to ~68 wt.% is accompanied by a decrease in resistivity from ~1*10-3 to ~3*10-4 ohms *cm.
Show AbstractSpecial Properties of Wideband Communication Based on Generators with Rough Dynamics
Special Properties of Wideband Communication Based on Generators with Rough Dynamics
D. O. Lubchenko$^{1,2}$, O. B. Isaeva$^{1,3}$
The article compares the efficiency of the information transmission based on the synchronization of different wideband signal generators, both in the presence of noise in the communication channel and in the conditions of frequency distortion of the signal transmitted in the communication channel. The generators of a hyperbolic chaos and a strange nonchaotic attractor, which are used in this work as generators of a signal, demonstrate complex dynamics and have a wide continuous spectrum. It was shown that the communication method based on a hyperbolic chaos is more sensitive to noise than on the generator of a strange nonchaotic attractor. The presence of a stopban in the low-frequency and high-frequency regions, however, makes it possible to detect the information with minimal distortion using communication circuits based on both generators.
Show AbstractDecoherence of neutrino oscillations in a magnetic field due to wave packets separation
Decoherence of neutrino oscillations in a magnetic field due to wave packets separation
A. R. Popov$^1$, A. I. Studenikin$^2$
Neutrino oscillations in a magnetic field considered within the formalism of wave packets. Damping of neutrino oscillations in a magnetic field due to neutrino wave packets separation is studied. The expressions for neutrino oscillations probabilities in a magnetic field accounting for decoherence effects are obtained. It is shown that the coherence lengths of oscillations on magnetic frequencies are proportional to the cube of neutrino energy. The obtained results are of interest for neutrino telescopes IceCube, Baikal-GVD and KM3NeT, and also can be applied for description of supernovae neutrino oscillations effects would be detected by JUNO, Hyper-Kamiokande and DUNE.
Show AbstractResearch works with schoolchildren using the example of studying the solar wind
Research works with schoolchildren using the example of studying the solar wind
S. B. Ryzhikov$^1$, Yu. V. Ryzhikova$^2$
The methodology for gradually involving schoolchildren in research activities from choosing a topic to conducting a computational experiment, analyzing the results and their further publication is considered. It is proposed to use the Euler scheme with modification to increase the accuracy of calculations. It is proposed to use modeling of the movement of charged particles in the Earth's magnetic field as a research direction. To simplify calculations, the Earth's field was considered a dipole. Coulomb interaction and particle radiation were neglected. Experience shows that schoolchildren master simple numerical methods very well. They can calculate particle trajectories, analyze them, and understand that particles can only reach the Earth's surface near the poles. The stages of the study are selected so that schoolchildren can gain useful knowledge and skills, even if they do not have the patience to complete the work.
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