[en] The dark mass problem is the most important for cosmology and galaxies physics. Various observational data of galaxies and galaxies clusters kinematics and dynamics require presence of massive dark matter. We estimate the dark mass within the galaxies optical radius using several different approaches, such as the maximum disk model, the marginal condition of the stellar disk gravitational stability and the vertical equilibrium condition in the galactic disk. The distribution functions of the relative dark mass within the optical radius R_opt for a set of 50 galaxies are constructed. Most of the objects from our set have a relative mass within µ = 2. This agrees well with the results of numerical simulations. (paper)

[en] One of the most common environmental problems of recent decades is the eutrophication of surface water and the associated algal bloom. As one of the approaches to eliminate this phenomenon, the use of biological methods, in particular biological preparations from barley straw, is considered. In this work presents the results of laboratory modeling of the effect of 1 and 2% (v/v) of barley straw (Hordeum vulgare L.) extract on the development of unicellular algae (Chlorella vulgaris Beijerinck). The alhistatic effect was evaluated by the parameters of algae growth, which were measured using the spectrophotometric and fluorescent methods. The parameters were measured at 0, 7, 14 and 21 days. The addition of barley straw extract reduced algae growth, both with the addition of 1% and 2% concentration. A two-day toxicity test using Daphnia magna Straus showed no toxic effect of barley straw extract for both 1% and 2% concentration. (paper)

[en] Hardware items are one of the products for mass consumption. Rolled metal for cold forging shall have the required ductility, uniform mechanical characteristics along the mill length, corresponding chemical composition and shall be free from internal or superficial defects. Standard mechanical characteristics have been reviewed in this document and fracture criteria of calibrated rolled steel 40X have been calculated after its isothermal treatment at different temperatures in nitre bath and subsequent drawing with different deformation degrees. Comparison of synergy fracture criteria showed that rolled stock, treated as per the proposed conditions: bath patenting at the temperature of 400°C and drawing with reduction rate of 5% and 10%, are more preferable, comparing to processing conditions, existing in the industry. (paper)

[en] The π⁰, η, K⁰, ω, and f₂(1270) masses were measured at the HYPERON-Msetup in meson-nucleus interactions at a momentum of 7 GeV/c by using six nuclear targets: Be, C, Al, Cu, Sn, and Pb. The experiment in question proved to be insensitive to the expected effects of a modification to the omega-meson mass in nuclear matter. As for the f₂(1270) meson, its mass and width values averaged over all experimental data, $m_{f_2}$ = 1275.8 ± 1.0(stat.) ± 0.4(syst.) MeV/c² and ${\mathrm{\Gamma <!--\; ??\; -->}}_{f_2}$ = 190.3 ± 1.9(stat.) ± 1.8(syst.) MeV/c², agree well with the world-average values. At the same time, our experimental data do not rule out the possible effect of an in-medium modification to the f₂(1270)-meson mass for heavy nuclei at a level better than 0.4%.

[en] Baryonic Matter at Nuclotron (BM@N) is a fixed target experiment at the NICA accelerator complex (JINR) aiming at studies of nuclear matter in relativistic heavy ion collisions. Triple-GEM (Gas electron multiplier) detectors have been identified as suitable for the BM@N central tracking system, which is located inside the analyzing magnet. A cathode strip chamber (CSC) is mounted outside the magnet to improve the momentum resolution of the experimental setup. Seven GEM detectors and one CSC are integrated into the BM@N experimental setup and data acquisition system. The structure of the BM@N GEM and CSC detectors and the results of the study of their characteristics are presented. The full configuration of the GEM/CSC tracking system is shortly reviewed.

[en] 

Abstract

: We have studied and optimized conditions for spontaneous flux growth of TbCr₃(BO₃)₄ crystals. Phase relations in the pseudoternary system TbCr₃(BO₃)₄–K₂Mo₃O₁₀–B₂O₃ have been studied in the temperature range 900–1130°C and the single-phase terbium chromium borate crystallization field has been mapped out. It has been shown that increasing the TbCr₃(BO₃)₄ content of the starting high-temperature solution leads to a rhombohedral-to-monoclinic phase transition. Using K₂Mo₃O₁₀-based high-temperature solutions, we have grown single-phase TbCr₃(BO₃)₄ single crystals or crystals in which the rhombohedral phase (sp. gr. R32) significantly prevails over the monoclinic phase (sp. gr. C2/c). The grown crystals have been characterized by X-ray diffraction techniques, IR spectroscopy, and magnetic measurements.

[en] Experimental and theoretical studies of direct photon production in hadronic collisions essentially expand our insights in multiparticle production mechanisms. These photons are useful probes to investigate nuclear matter at all stages of the interaction. Soft photons play a particular role in these studies. Until now we have no explanation for the experimentally observed excess of soft photons. These photons have low transverse momenta p_T < 0.1 GeV/c, vertical stroke x vertical stroke < 0.01. In this domain their yield exceeds the theoretical estimates by 5-8 times. The registration of soft photons at Nuclotron (LHEP, JINR) has been carried out by the electromagnetic calorimeter built by the SVD-2 Collaboration. Soft photon electromagnetic calorimeter was tested at U-70, IHEP (Protvino). For the first time the soft photon yield at interactions of 3.5 A GeV/c per nucleon deuterium and lithium beams has been measured. The obtained energy spectra confirm the increased yield of soft photons with their energy less than 50 MeV (in the laboratory system) in comparison with theoretical predictions and agree with previous experiments at high-energy interactions. It is planned to continue soft photon study at the future accelerator complex NICA with heavy-ion beams. (orig.)

[en] Results of searches for the pentaquark states Ξ(1860)⁰ and Ξ(1860)^-- in neutron-carbon interactions at an average neutron energy of about 51 GeV via the EXCHARM experiment are presented. No such states are found in the Ξ^-π⁺ and Ξ^-π^- effective-mass spectra examined in this study. Upper limits on the cross sections for Ξ(1860)⁰ and Ξ(1860)^-- production are estimated

[en] Interference correlations of neutral-kaon pairs produced in the interactions of 20-to 70-GeV neutrons with a carbon target are studied by using the EXCHARM spectrometer. Constructive correlations at low relative 4-momenta are observed for K_S⁰K_S⁰ pairs. The kaon-generation radius is determined

[en] The features of the associated production of φ mesons and neutral kaons are studied on the basis of data obtained at the EXCHARM spectrometer (Serpukhov accelerator) in neutron-carbon interactions at neutron-beam energies in the range 20-70 GeV. The cross section for the inclusive associated production of φ and K⁰/-K⁰ is obtained. The fraction of processes allowed by the Okubo-Zweig-Iizuka rule is estimated in the reactions of φ-meson inclusive production