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In this paper, the transport characteristics of two-dimensional systems has been investigated. Modeling by means of the Yukawa potential, in a wide range of values of the nonideality parameter, has been carried out. The Yukawa potential was chosen because of its wide applicability in the description of screened interactions in plasmas and other systems. A molecular dynamics method was used to determine the transport characteristics. The study was carried out with the aim of expanding the knowledge of heat transfer in two-dimensional systems. The paper presented the results of numerical experiments in which the dependences of the heat transfer and viscosity coefficients on the screening and non-ideality parameters in systems with Yukawa potential were studied. The obtained data can also serve as a basis for further theoretical and experimental studies in the field of transport characteristics of two-dimensional systems. These data not only expand the understanding of the peculiarities of two-dimensional systems, but also can be useful in the design and analysis of nanostructures and various microdevices. [ABSTRACT FROM AUTHOR]

The paper is devoted to development of atypical excitation approaches of bistatic laser monitor active elements for the imaging of high-speed processes at a powerful background radiation. The practical significance is increasing the temporal resolution of the bistatic laser monitor, as well as improving the imaging parameters by minimizing the jitter of radiation pulses. To achieve this goal, semiconductor excitation sources of active media based on copper bromide vapor were developed, and their synchronization was performed in a pulse-repetition mode. The developed pump sources are set of identical commutation cells. Each cell contains storage capacitor, commutator and transformer. Powerful HGTG27N120BN insulated-gate bipolar transistors (IGBT) were chosen as commutators. Their switching storage capacitors are discharged through the primary winding of the transformer and as result the voltage pulse is induced in the secondary winding. The transformer load was the gas discharge tube (GDT) of the small-size brightness amplifier with the specified geometric parameters (l = 40 cm, d = 2.5 cm, V = 196 cm3). The simultaneous switching of 10 identical cells provided GDT breakdown. The radiation power of the active element in oscillator mode was 665 mW. The developed brightness amplifier with semiconductor pump source was used in the bistatic scheme of the laser monitor for the imaging of the test object. The pumping of the second active element, the illumination source (l = 90 cm, d = 5 cm, V = 1767 cm3), was performed by means of thyratron TGI1-1000-25. The pulse repetition frequency of the illumination source and the brightness amplifier was 10.5 and 21 kHz respectively. As result each second image was formed with increased brightness and contrast. The maximal jitter of radiation pulses in this case was 16 ns. The average jitter was 6 ns. Two identical semiconductor pump sources were tested simultaneously. The resulting array of waveforms (GDT current and GDT voltage) show that in most cases the jitter was completely absent, and when it appeared, it did not exceed 4 ns. The imaging at this configuration of the pump sources was not performed due to semiconductor source power (465 W) turned out to be insufficient for the excitation of the illumination source, and therefore options for increasing it were proposed. [ABSTRACT FROM AUTHOR]

Interest in beryllium-based composite materials has emerged recently, when intermetallic compounds such as titanium beryllide Be12Ti began to be considered as a promising material for neutron multiplication in thermonuclear fusion facilities, such as ITER and DEMO. Titanium beryllide stands out from other beryllides because it has the highest neutron multiplication rates and also has the added benefit of being more thermally stable than beryllium metal. Titanium beryllide interacts much weaker with water vapor, excluding the possibility of the formation of explosive hydrogen in the blanket body, is less prone to gas swelling, and, unlike metallic beryllium, retains a smaller amount of accumulated tritium. It has also been confirmed that the compatibility of titanium beryllide with structural materials is much higher than that of beryllium. To use titanium beryllide, it is important to study the parameters of its interaction with hydrogen isotopes. One of the most well-known methods for is the method of thermal desorption spectroscopy (TDS). The objective of this paper is the development of a specialized experimental setup for TDS research and the development of a methodology for performing experiments. The results of methodical experiments are presented, in which the procedures for saturation of samples in a deuterium medium and procedures for conducting TDS experiments were worked out. Methodical experiments on studying the parameters of the interaction of deuterium with samples of monolithic titanium beryllide were carried out on the material produced by Ulba Metallurgical Plant JSC, saturated in deuterium at atmospheric pressure and a sample temperature of 973 K. linear heating rates of 10 and 20 K/min. Based on the results of the development of the technique for conducting experimental studies of titanium beryllide, a differential mode of the TDS method was recommended. In this case, it is necessary to use a hydrogen isotope, deuterium, as a control probe. [ABSTRACT FROM AUTHOR]

The method of moments is used to investigate and analyze the dynamic characteristics of dense systems consisting of ions of two types with different masses and charges, and the number of screening electrons corresponding to the charges of the ions. In this paper, we discuss the characteristics of a binary ionic mixture whose component masses differ by a factor of two. Within the framework of the developed self-consistent method of moments, the dynamic structure factors (DSF) of such a plasma are calculated for various thermodynamic parameters. In this case, the calculation algorithm is based on the use, on the one hand, of the static structural factor of the system, which is determined from the solution of the Ornstein-Zernike equation, and on the other hand, the so-called Nevanlinna parameter function (NPF), which is included in the calculated relations. The calculations were carried out within the framework of the classical system of charged particles interacting according to the Coulomb law. The paper analyzes the data obtained using various methods for calculating the NPF. The results obtained in this work qualitatively and quantitatively agree with the data of theoretical calculations and numerical experiments of the authors of other studies of the dynamic properties of a dense multicomponent plasma. [ABSTRACT FROM AUTHOR]

In this paper, a periodic cosmological model is considered. Previously, it was assumed that the expansion of the universe slows down over time. Theorists proceeded from the assumption that the main part of the mass of the Universe is matter - both visible and invisible (dark matter). On the basis of new observations indicating the acceleration of expansion, it was found that in the Universe there is a previously unknown energy with negative pressure (equation of state). They called it "dark energy". In this paper, a scalar cosmological model is considered. The Lagrangian is derived and the system of equations of motion is obtained. To study the model, a scalar field in the form of a periodic function was chosen. The Hubble parameter, the scale factor, which has the meaning of the radius of the Universe, and in the case of a periodic function of the scalar field, which has an exponential dependence, the density of dark energy, the pressure and the potential of the scalar field are calculated, and their graphs are plotted in the time dependence section from 0 to 2π. To study the inflationary model, the potential is introduced in a power-law form. From it, the parameters of slow rolling through e-folding are derived and a plot of spectral indices for this model is plotted. The results obtained are consistent with the Planck observational data and confirm the correspondence of the model under study with the previously proposed ones. [ABSTRACT FROM AUTHOR]

It is difficult to overestimate the role and place of computational experiments in modern scientific research. Scientists investigate physical phenomena based on computer models and computational experiments when analytical methods of theoretical physics do not allow obtaining more reliable results. On the other hand, computational experiments can be carried out in conditions inaccessible to field experiments. The paper presents the scientific results of the study of some issues of celestial mechanics. These results are obtained on the basis of the use of computer methods. The MathCAD application software package is used as a programming language. The main scientific results include the following: a graph of the potential of the gravitational field of the Earth is constructed depending on the distance r to the center of the Earth; on the basis of a computer approach, the equations of the potential energy (binding energy) of the interaction of a body of a unit mass with the Earth-Moon system are studied; on the basis of computer methods, graphs are obtained. These graphs characterize the binding energies of the body depending on the coordinates of the radial axis; with the help of the MathCAD package, the flight path of the spacecraft near the Earth was modeled under various initial conditions; the motion of the spacecraft from the Earth to the Moon was studied and various types of flight paths were constructed depending on its initial velocity. [ABSTRACT FROM AUTHOR]

In this paper, a new method for measuring the neutron flux using proportional counters SNM-18 filled with 3Ne is studied. When developing equipment for automated measurement of the neutron flux of the research reactor VVR-K, the determining optimization criteria are power consumption, weight and dimensions. For this purpose, devices were used for automated measurement of the equivalent of soil moisture and the equivalent of snow water by the neutron component of cosmic rays. A number of experimental studies have been carried out to determine the optimal levels of supply voltages, the design of the device for operation at the VVR-K reactor has been changed. The main elements of the neutron detector design are a block of a hydrogen-containing moderator; a tube of a proportional thermal neutron counter; an amplifier and a microcontroller for analyzing the signal from the detector; a high-voltage power supply and a transmitter. Special software has also been developed for simultaneous control of detectors. Test measurements of the neutron flux were performed at the research reactor plant VVR-K INP using a Pu-Be neutron source, with an intensity of 1.8 *106 n/s. To reduce the neutron intensity for the safety of personnel and to reduce the load on the detector, the neutron source was placed inside a boron polyethylene collimator. [ABSTRACT FROM AUTHOR]

This paper presents the results of thermodynamic and experimental studies of plasma-thermal processing of ash with the production of fuel gas and inert mineral material are presented. Plasma-thermal processing of ash and slag wastes consists in their heating, pyrolysis and melting to remove residual carbon and obtain a neutral melt, the storage and use of which after cooling does not cause environmental problems. Ash from Ekibastuz coal, which is widely used in the energy sector of Kazakhstan, is taken as ash and slag waste, which is a set of components of the mineral mass of coal and unburned carbon. Calculations have shown that during the plasma-thermal processing of ash and slag waste, combustible gas is obtained with a CO concentration of up to 86.8% and a calorific value of 8752 kJ/kg and a melt of mineral components that does not contain harmful impurities. The plasma reactor is a melting chamber covered by an electromagnetic coil. The chamber has the shape of an equilateral triangle in section, with three inclined immersed graphite electrodes at its corners. The reactor was started up by shorting the power electrodes to a bulk graphite track. After obtaining the melt channel, the heating of ash and slag waste continues due to the conduction currents between the power electrodes through the resulting melt. To homogenize the melt, it is stirred electromagnetically. The melt productivity of the reactor was 100 kg/h at its temperature of 1923 K and specific energy consumption of 0.96 kW h/kg. Both in calculations and in experiments, no harmful impurities were found in the products of plasma processing of the investigated wastes. [ABSTRACT FROM AUTHOR]

When negatively charged particles are scattered by atomic nuclei before the thresholds of excitation of nuclei, the formation of a metastable system "charged particle + excited nucleus" is possible. In particular, during the scattering of μ-mesons by nuclei, mesoatoms with an excited nucleus in the states of the entire atomic spectrum of hydrogen-like atoms can arise. This infinite set of states of a quasi-bound system generates an infinite series of elastic scattering resonances in the continuous spectrum, which condenses to the threshold energy of the excitation of the nucleus. In cases where the elastic scattering widths of mesons are smaller than the decay width of the excited state of the nucleus, inelastic meson resonance decay channels arise, which make it possible to observe them experimentally in the process of resonant scattering. In the present work, an analytical expression is obtained for the widths of subthreshold resonances arising from the scattering of μ mesons by atomic nuclei. The widths of subthreshold resonances in such systems are explicitly expressed in terms of the reduced multipole matrix elements of nuclear transitions The paper presents estimates for dipole excitations of nuclei corresponding to the farthest resonant states. It is shown that modern meson facilities make it possible to directly determine the reduced matrix elements of dipole transitions in experiments on elastic meson scattering. For a group of nuclei with large widths of E1 γ-radiation, it is possible to set up an experiment to determine these widths, and for known widths, to determine the chemical composition of the target. [ABSTRACT FROM AUTHOR]

The paper considers the modernization of the methodology for studying astrophysical ice and cold interstellar dust. An experimental method of physical modeling using a vacuum cryogenic installation is presented. The nodes of the universal vacuum cryogenic spectrophotometer where it is necessary to modernize, retrofit for the subsequent improvement of measuring capabilities in scientific research are considered in detail. The IR spectra of polystyrene were obtained on the IRS-29 and FSM 2203 spectrometers, the results of the obtained characteristic absorption bands were compared with the values of the reference spectrum of polystyrene, and the expanded uncertainty was calculated. To assess the accuracy of the measurement results, we calculated the expanded uncertainty according to the IR spectrometer calibration procedure. The wavenumber scale calibration uncertainty was determined by direct measurements as the difference between the wavenumber value corresponding to the maximum ordinate of the absorption line of a standard polystyrene film sample. In this work, an analysis of the completed retrofitting of a universal vacuum cryogenic spectrophotometer was carried out. N2O spectra were taken, obtained at a temperature of 16 K in the wave number range of IR spectrometers from 370 to 4200 1/cm with the designation of the corresponding absorption bands. The studies carried out in this work are aimed at improving the accuracy of measurements, which guarantees and improves the quality of scientific research. [ABSTRACT FROM AUTHOR]

The paper considers the problem of studying the daily distribution of the passage of meteoroids by radio observation. The advantages of the chosen method of registration over the classical optical and photographic methods of observation are considered. A voluminous series of data was obtained using a registration facility implemented on the basis of the Center for Astrophysical Research at the North Kazakhstan University named after Manash Kozybayev. Processing, analysis and systematization of the obtained data on meteor phenomena have been carried out. Based on the obtained observational data, on the basis of the Center for Astrophysical Research at the North Kazakhstan University named after Manash Kozybayev, using the Multi VirAnalyzer program, namely the Date Recorder, the daily distribution of the meteor flight frequency was calculated. Also, with the help of the Microsoft Excel software application, diagrams of the daily distribution of the meteor passage frequency were constructed. During the analysis of the obtained diagrams of the daily distribution of the meteor passage frequency, the peak and average daily values of meteor activity were determined. Based on the daily distribution, diagrams of the frequency of meteor passages were constructed for certain months during which the Perseid and Leonid meteor showers are active. A clear correlation with the results of studies of other laboratories of a similar line of research is shown. [ABSTRACT FROM AUTHOR]

In this paper, a model of a pulsating universe is investigated with periodic function of the scale factor together with a homogeneous, isotropic and spatially flat Friedman-Robertson-Walker metric. The parameters of the pulsating universe model coincide with observation parameters of the modern universe, taking into account the different contributions of various types of matter to its evolution. In the resulting solution, during periods of accelerated expansion of the universe, the scalar field with negative pressure makes a greater contribution to the expansion growth. The fermionic field and the vector field, which have positive pressure values during this period, prevent the growth of this expansion. During periods of compression, the fermionic field and the vector field have a greater influence on the dynamics of the evolution of the universe. In the resulting periodic solution, the universe goes through endless cycles of expansion and contraction. The observed modern accelerated expansion of the universe corresponds to one of these cycles. Cosmographic parameters are calculated - parameters of deceleration q, jerk j and snap s and energy conditions for the model under research. These parameters make it possible to link model-independent results obtained from cosmography with theoretically sound assumptions of gravity. [ABSTRACT FROM AUTHOR]

The article outlines ways to improve the organization of independent work of university students. Innovative education is the use of the latest information technologies in the entire didactic complex of information support for the subject. The innovative model of teaching physics in higher education includes methodologically structured information presented in the form of one of the types of the infosphere - a system of interrelated and interdependent textbooks and other means of educational activity (modular programs, electronic lectures, various methodological aids). In the new conditions of increasing the volume and strengthening the role of students' independent work in the educational process, students receive and master only methodological information at the appropriate level. To master the material on a regular basis, a student needs to work for months, and only a qualified teacher who knows the psychological characteristics of the learning process and owns the teaching methodology will help save the student's time by transforming the professional knowledge of teachers into educational knowledge. The paper shows the types and stages of performing classroom, extracurricular IWS in physics, as well as ways to improve the efficiency and quality of students' educational work. [ABSTRACT FROM AUTHOR]

This paper presents a study of the temperature distribution on a universal cryogenic surface when it is cooled to nitrogen temperatures. Using computer simulation methods, in particular the finite element method, it was possible to determine the temperature-time dependences that occur during the cooling of a surface using the heat exchange tubes of different diameters located inside the surface at equal distances from each other. By varying the diameter of the heat exchange tubes, its effect on the cooling intensity was revealed when examining the volumetric temperature distribution: a larger diameter of the heat exchange tube yields a more uniform cooling of the surface. Besides, a larger orifice diameter leads to reaching thermal equilibrium quicker over the entire surface examined. By using a 7 mm orifice diameter, thermal equilibrium was reached 70 seconds after the start of cooling while 5 mm and 3 mm orifice diameters reached temperature equilibrium after 90 and 100 seconds respectively. The results obtained will make it possible to produce cooling of higher quality when designing universal cryogenic surfaces by using heat exchange tubes with certain geometric parameters. [ABSTRACT FROM AUTHOR]

This paper presents the results of statistical analysis of ionospheric disturbances in the integral electronic content, NF, during the period of registration of the Faraday effect at the point of Almaty [43,20N; 76,90E] when receiving signals from the ETS-II satellite (Engineering Test Satellite Type-II), located in geostationary orbit [00N; 1300E], the radio beacon of which operated at a frequency of 136,112 MHz. The analysis of the classification characteristics of each specific event showed that perturbations in the integral electronic content can occur both with a positive (35 cases out of 83) and with a negative sign in (37 cases out of 83), as well as with a change of phases (with a change of sign) in the course of the perturbation. According to the start time, ionospheric disturbances tend to occur more often in the evening and at night, with a greater probability at 17 LT -22 LT. During the year, NF disturbances occur most frequently in the months of November, December, January, February, and March. A decrease in the number of ionospheric disturbances is detected based on the data on the integral electron content of the ionosphere during the period of high solar activity. The «disappearance» of storms in the integral electron content occurs approximately at F10. 7 > 180, which is probably due to the «saturation» effect in the ionosphere. [ABSTRACT FROM AUTHOR]

Concrete is one of the most common building materials that is used in many areas of human activity, from the construction of residential buildings to industrial buildings and more. In the nuclear power industry, concrete is used not only as a structural material, but also as a material for biological protection. Usually concrete mix consists of cement, coarse and fine aggregates, water and various additives. Based on the field of application of concrete, the correct ratio of its components is selected. This paper presents the results of a study of the effect of the composition of concrete on its internal structure. The studies were carried out by the non-destructive method of neutron radiography and tomography at the facility, which is located on one of the horizontal channels of the WWR-K reactor. As a result of the studies carried out by the non-destructive method of neutron radiography and tomography, concrete samples of three different types of brands were studied. The distribution of pores and cracks in each sample is shown. The attenuation coefficients of neutron radiation for the studied concrete grades are given. The rate of water migration in concrete of different grades is estimated. The applicability of the neutron radiography and tomography installation for this type of investigation of the internal structure of concrete was demonstrated. [ABSTRACT FROM AUTHOR]

In this paper, the processes of electron-ion scattering in the plasma of inertial confinement fusion in a magnetic field were studied. The proposed model for studying the processes of scattering between charged particles is based on solving the equation of motion in a central field taking into account the external magnetic field, as well as the Coulomb logarithm, which is determined using the scattering angle in a pair collision. Collisions between an electron and an ion that interact via the Yukawa potential were investigated. Also, the Coulomb logarithm in a dense plasma in a magnetic field was calculated. The effect of taking into account the magnetic field on the scattering angles, the scattering cross-section and the Coulomb logarithm are studied. From the results obtained, it is established that taking into account the magnetic field led to a non-monotonic change in the scattering angle and a decrease in the scattering cross-section for weak particle interactions. It is also revealed that for large values of the interaction parameter β, the magnetic field does not affect the value of the Coulomb logarithm. Thus, the obtained results allow us to study the effect of taking into account the magnetic field on the processes of electron scattering on an ion in the approximation of pair collisions in an external constant magnetic field in a dense plasma. [ABSTRACT FROM AUTHOR]

The CubeSat concept has become very popular with both university groups and researchers, space agencies, governments and companies. CubeSat offers a fast and affordable way for a wide range of stakeholders to be active in space. Due to the high degree of modularity and widespread use of offtheshelf commercial subsystems, CubeSat projects can be prepared for flight much faster than using traditional satellite schedules usually within one to two years. In this paper, we have considered a model of an S and X band patch antenna for CubeSat nanosatellites in the field of Earth remote sensing (ERS). The antenna dimensions were determined and designed according to the dimensions of the small spacecraft. The shape of the emitting part was formed using a geometric fractal with an anisotropic structure. Using the CST Microwave Studio software package, the electrodynamic, frequency characteristics and directional properties of the antenna were determined. The results of computer simulations demonstrate that the developed antenna concept has a multiband property and meets all the parameters that are necessary for receiving and transmitting data in the S and X bands. It was also found that the anisotropic fractal structure allows the antenna to have several operating frequencies. [ABSTRACT FROM AUTHOR]

It is known that by changing the concentration in an inert medium, it is possible to form clusters of various sizes of any substance by condensing them on a cold substrate from the gas phase. Traditionally, such systems are presented by molecular cryocrystals. This paper demonstrates the results of IR spectrometric studies of cryovacuum condensates of ethanol mixture with nitrogen. The main task of this study is to explain the complex, most often, ambiguous behavior of thin films of ethanol cryovacuum condensates in the process of its cocondensation with nitrogen. For this purpose, vibrational spectroscopy of cryodeposited thin films of "ethanol in nitrogen" mixtures in various concentration ratios was performed. The objects of research are thin films of cryocondensates of ethanol mixture with inert gas (N2). The samples were condensed at the temperature T = 16 K. The pressure of the gas phase of the mixture during cryocondensation was kept at P = 105 Torr. The range of ethanol concentrations in the mixtures varied from 3% to 90%. The spectral range of measurements was considered in 4004200 1/cm. It is assumed that the change in the concentration of ethanol in the mixture leads to the formation of various cluster compositions of ethanol molecules dissolved in an inert medium. [ABSTRACT FROM AUTHOR]