Particle lateral distributions were investigated in cosmic ray air showers with energy
eV registered at the Yakutsk array with surface and underground scintillation detectors with
GeV threshold ...during the period of continuous observations from 1986 to 2016. The analysis covers events with arrival direction zenith angles
within five intervals with step
. Experimental values were compared to simulation results obtained with the use of CORSIKA code within the framework of QGSJet-01-d hadron interaction model. The whole dataset points at probable cosmic ray composition which is close to proton one.
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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, SIK, UILJ, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
The heaviest elements to have been chemically characterized are seaborgium (element 106), bohrium (element 107) and hassium (element 108). All three behave according to their respective positions in ...groups 6, 7 and 8 of the periodic table, which arranges elements according to their outermost electrons and hence their chemical properties. However, the chemical characterization results are not trivial: relativistic effects on the electronic structure of the heaviest elements can strongly influence chemical properties. The next heavy element targeted for chemical characterization is element 112; its closed-shell electronic structure with a filled outer s orbital suggests that it may be particularly susceptible to strong deviations from the chemical property trends expected within group 12. Indeed, first experiments concluded that element 112 does not behave like its lighter homologue mercury. However, the production and identification methods used cast doubt on the validity of this result. Here we report a more reliable chemical characterization of element 112, involving the production of two atoms of 283112 through the alpha decay of the short-lived 287114 (which itself forms in the nuclear fusion reaction of 48Ca with 242Pu) and the adsorption of the two atoms on a gold surface. By directly comparing the adsorption characteristics of 283112 to that of mercury and the noble gas radon, we find that element 112 is very volatile and, unlike radon, reveals a metallic interaction with the gold surface. These adsorption characteristics establish element 112 as a typical element of group 12, and its successful production unambiguously establishes the approach to the island of stability of superheavy elements through 48Ca-induced nuclear fusion reactions with actinides.
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DOBA, IJS, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Resistivity, ρ(T), and magnetoresistance (MR) are investigated in graphene grown on SiC (0 0 0 1), at temperatures between T ~ 4-85 K in pulsed magnetic fields of B up to 30 T. According to the Raman ...spectroscopy and Kelvin-probe microscopy data, the material is a single-layer graphene containing ~20% double-layer islands with a submicron scale and relatively high amount of intrinsic defects. The dependence of ρ(T) exhibits a minimum at temperature T
~ 30 K. The low-field Hall data have yielded a high electron concentration, n
≈ 1.4 × 10
cm
connected to intrinsic defects, and a mobility value of µ
~ 300 cm
(Vs)
weakly depending on T. Analysis of the Shubnikov-de Haas oscillations of MR, observed between B ~ 10-30 T, permitted to establish existence of the Berry phase β ≈ 0.55 and the cyclotron mass, m
≈ 0.07 (in units of the free electron mass) close to expected values for the single-layer graphene, respectively. MR at 4.2 K is negative up to B ~ 9 T, exhibiting a minimum near 3 T. Analysis of MR within the whole range of B = 0-10 T below the onset of the SdH effect has revealed three contributions, connected to (i) the classical MR effect, (ii) the weak localization, and (iii) the electron-electron interaction. Analysis of the ρ(T) dependence has confirmed the presence of the contributions (ii) and (iii), revealing a high importance of the electron-electron scattering. As a result, characteristic relaxation times were obtained; an important role of the spin-orbit interaction in the material has been demonstrated, too.
Lateral distribution functions of particles in extensive air showers with the energy
eV recorded by ground-based and underground scintillation detectors with a threshold of
GeV at the Yakutsk array ...during the continuous observations from 1986 to 2016 have been analyzed using events with zenith angles θ ≤ 60°. Experimental functions have been compared to the predictions obtained with the QGSJet-01-d hadron interaction model by applying the CORSIKA code. The entire dataset indicates that cosmic rays consist predominantly of protons.
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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, SIK, UILJ, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
The lateral distribution of particles in extensive air showers from cosmic rays with energy above 10
17
eV registered at the Yakutsk complex array was analyzed. Experimentally measured particle ...densities were compared to the predictions obtained within frameworks of three ultra-high energy hadron interaction models. The cosmic ray mass composition estimated from the readings of surface-based and underground detectors of the array is consistent with estimations obtained from measurements of lateral distribution of the air showers Cherenkov light emission. A comparison was made with the results of direct measurement of the muon component performed at the Pierre Auger Observatory. It is demonstrated that the densities of muon flux measured at Yakutsk array are consistent with results of fluorescent light measurements and disagree with results on muons obtained at the Auger array.
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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, SIK, UILJ, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Here we consider the results of direct measurements of muons in extensive air showers with zenith angles
and energy above
eV, obtained at the Pierre Auger Observatory and Yakutsk array. In both ...experiments muons were registered with underground scintillation detectors with
GeV energy threshold. Measured density values were compared to theoretical predictions calculated within the framework of the
qgsj
et-
ii
.04 hadron interaction model. They differ by factor
(stat). We demonstrate that this difference is due to overestimation of muon densities by 1.22 times and underestimation of primary energy by 1.25 times in the Auger experiment.
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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
Lateral distribution of muons in extensive air showers registered at the Yakutsk array was investigated. The analysis covers two periods of observation: before 2018 and after 2020, when the revision ...of muon detectors with 1-GeV threshold was complete. Measured values of muon density are compared to computational results obtained within the framework of two hadron interaction models. Within the energy domain above 10
18
eV the best agreement is observed for proton composition primary cosmic rays.
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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
In this paper, the influence of the surface material of a streamlined cylinder on the characteristics of large-scale velocity pulsations is experimentally investigated using the methods of studying ...the flow structure, namely PIV (Particle Image Velocimetry) and POD (Proper Orthogonal Decomposition). A comparison of the parameters of the near wake in the range of Reynolds numbers of 70 000 - 180 000 is presented for cylinders made of vacuum rubber (hydrophilic material) and fluoroplast (hydrophobic material) of the same diameter. Using the PIV method, instantaneous and averaged velocity fields are obtained. The size of the separation zone is determined based on the average velocity fields. The spatial shape and kinetic energy of the observed large-scale ripples in the wake region are analyzed using the POD statistical method. In the studied range, the transition to the critical flow mode for the fluoroplast cylinder is recorded. For the case of flow around a rubber cylinder, the character of pulsations in the wake zone remains unchanged throughout the studied range.
Abstract
The degree of the dry matter (DM) digestibility of the diet and the effect of additional administration of linseed oil on the composition of the rumen microbiome of cattle were studied. The ...in vitro method was used using the incubator "ANKOM Daisy II "(modifications D200 and D200I) according to a specialized technique. Microflora analysis was performed using MiSeq ("Illumina", USA) by the new generation sequencing method (NGS) with a set of MiSeq reagents. With the introduction of linseed oil, an increase in the digestibility of DM feed by 2.3% relative to the control (wheat bran) was noted. In the experimental group the level of species diversity was 45% higher than in the control group. The Simson dominance index in the control group was 0.44, in the experimental group it is 0.54. The Shannon index was equal to E=0.3, which shows a greater alignment of the microbial community in the ruminal fluid when flaxseed oil was included. There was an increase in the number of bacteria of the phylum Bacteroidetes (64.2 %) and a decrease in Firmicutes (19.3 %)., There was an increase in the number of microorganisms belonging to the classes Saccharibacteria, Spirochaetia, Mollicutes, Lentisphaeria, Elusimicrobia in the experimental group, relative to the control. Also it is an increase in representatives of all classes of the phylum Proteobacteria in comparison with the control by 44 % (p < 0.05).
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