CMD-3 muon system efficiency Korobov, A.A.; Shwartz, B.A.; Vorobiov, A.I.
Journal of instrumentation,
10/2020, Volume:
15, Issue:
10
Journal Article
Peer reviewed
The Muon system of the CMD-3 detector is described. This system, aimed at measuring the time and position of muons passing through CMD-3, is the outermost part of the detector and is made of thin ...plates of plastic scintillators. A measurement of the system efficiency is presented.
Complete description is given of the linear pointwise degenerate fourth-order delay-differential systems (with constant coefficients) whose active matrix is semisimple and the passive matrix is ...nonnilpotent. These systems are described with the help of the language of geometrical invariants of certain elements of the semigroup generated by the matrices of the system.
The article presents the results of experimental studies of how 3D printing with 100% filling influences the elastic properties of PLA filament polymer samples. The static and Thurston–Brugger ...methods simultaneously measure the dependence of strain and the relative change in the velocity of elastic waves on the applied mechanical stress (up to failure) for the initial and 3D-printed samples of the PLA polymer. Based on the measurement results, the linear and nonlinear Young’s moduli and second-order acoustic nonlinear parameter are calculated. It has been established that 3D printing leads to a deterioration in the strength and plastic characteristics of PLA. A different behavior of the nonlinear parameters of the initial and 3D-printed PLA samples in the loading and unloading region was revealed, associated with a change in the internal structure of the sample caused by 3D printing.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Research results for the nonlinear acoustic properties of the B95 polycrystalline aluminum alloy and the B95/nanodiamond composite have been described. The nonlinear properties of the alloys have ...been studied by the spectral method that measures the efficiency of generation of the second harmonic of a bulk acoustic wave at a frequency of 2
f
= 10 MHz in the field of a finite-amplitude longitudinal acoustic wave at a frequency of
f
= 5 MHz. The results derived by this method have been compared with the results of studies of the nonlinear acoustic properties of the test alloys using the Thurston–Brugger quasi-static method.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
The purpose of the study is to create a model of the cardiovascular system that gives an adequate description of the processes of hemodynamic regulation for the needs of intensive care. An overview ...of the most recent significant blood circulation models that take the regulation processes into account is proposed, the peculiarities and limitations of such models are identified. The methods of computational hemodynamics and mathematical modeling are used. A zero-dimensional dynamic mathematical model of cardiovascular system with two regulatory contours suggested by its authors is described. The results of the study are of interest to intensive care doctors in selecting a treatment strategy.
The L-tryptophan sublimation was studied by high-temperature mass spectrometry in the temperature range 395–493 K. The compound evaporates congruently in the form of monomeric molecules. The ...saturated vapor pressure at 485 K was determined by the Knudsen effusion method. In combination with mass spectrometric data, the pressure equation ln (
p
, Pa) = –(19943±304)/
T
+ (40.568±0.688) is recommended for the temperature range 395–493 K. The enthalpy of 167.5±1.6 kJ/mol for sublimation at 298.15 K was determined on the basis of the second and third laws of thermodynamics.
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DOBA, EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, IZUM, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UILJ, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
In this study, we investigated the acoustical properties of custom-designed phononic crystal-like acoustic metamaterials 3D printed from ABS plastic. The elastic properties of these metamaterials ...were studied experimentally and numerically. The metamaterial consisted of a set of plane parallel lattices the number of which could vary in different samples. Each lattice in the sample consisted of 16 parallel square rods. The amplitude-frequency characteristics (AFC) of the fabricated metamaterial sample were measured in the frequency range (35-100) kHz using longitudinal acoustic waves both in air and water. The propagation velocities of longitudinal and shear acoustic waves of ABS plastic itself were measured prior to the experiment. The band gaps (stop bands) were detected and investigated while measuring AFC of the metamaterials. We have found that the increase in the number of lattice layers in the sample led to the band gap acoustic wave attenuation coefficient increase along with the band gap narrowing, while the central frequency of the band gap remained the same. The numerical simulation of the sample frequency response was carried out in COMSOL. The results of experimental studies and numerical simulations were in satisfactory agreement. We have also investigated the ultrasound scattering diffraction pattern of the sample. The obtained results can be used in solid-state physics and material science, to create materials with controlled frequency-dependent acoustic properties.
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