High-Field Low-Frequency Spin Dynamics

The theory of exchange symmetry of spin ordered states is extended to the case of high magnetic field. Low frequency spin dynamics equation for quasi-goldstone mode is derived for two cases of collinear and noncollinear antiferromagnets.Comment: 2 page

Hybrid Simulation of a Radioisotope Neutron Source based on a Mixture of Stable Crystals of Am and Be Oxides

In this paper, a procedure was proposed for calculating the neutron yield and the spectrum of the Am-Be source for different granular size of the source mixture. With the combined use of the calculation codes SOURCES-4C and MCNP5, computational models of the source differing in the structure of the mixture and the energy spectrum were presented. By calculating of neutron transport, an analysis of the appearance and loss of neutrons in the sources and in the steel shell of the source was carried out. As a result of the work, it became clear how the grain size of the source mixture affects the neutron yield

Triplet spin resonance of the Haldane compound with interchain coupling

Spin resonance absorption of the triplet excitations is studied experimentally in the Haldane magnet PbNi2V2O8. The spectrum has features of spin S=1 resonance in a crystal field, with all three components, corresponding to transitions between spin sublevels, being observable. The resonance field is temperature dependent, indicating the renormalization of excitation spectrum in interaction between the triplets. Magnetic resonance frequencies and critical fields of the magnetization curve are consistent with a boson version of the macroscopic field theory [Affleck 1992, Farutin & Marchenko 2007], implying the field induced ordering at the critical field, while contradict the previously used approach of noninteracting spin chains.Comment: 7 pages, 9 figure

The Role of the Juvenile Commission and the Protection of Their Rights in the Child Protection System

The article examines the role of the Commission for Juvenile Affairs and the protection of their rights as a coordinating body of the subjects of the system of prevention of neglect and delinquency of minors.В статье рассматривается роль комиссии по делам несовершеннолетних и защите их прав, как координирующего органа субъектов системы профилактики безнадзорности и правонарушений несовершеннолетних

Structure and microhardness of titanium-based coatings formed by multichamber detonation sprayer

A series of titanium-based coatings (50-550 m thick) on an aluminium substrate was deposited via multichamber detonation sprayer with different barrel lengths (300, 400, and 500, all in mm). The titanium-based coatings obtained in these three experiments were examined by optical microscopy, scanning electron microscopy, and X-ray phase analysi

Deposition and characterization of alumina-titania coating by multi-chamber gas-dynamic sprayer

In this paper, alumina-titania coatings have been formed on aluminium substrate by multi-chamber detonation sprayer. The results show that the alumina-titania coatings consist of both fully melted regions and partially melted regions, and the fully melted region has a lamellar-like structur

Deposition and characterization of the titanium-based coating by a multi-chamber detonation sprayer

This work introduces some of the aspects of the deposition of titanium-based coating (80-120 μm thick) on aluminium samples using a multi-chamber detonation sprayer (MCDS). It was established that MCDS has provided the conditions for formation of a dense titanium-based coating with a porosity of less than 1.0%, microhardness 810±250 HV0.05 and a specific wear rate of 2.077·10-4 mm3(m·N)-

Quasi two-dimensional antiferromagnet on a triangular lattice RbFe(MoO4)2

RbFe(MoO4)2 is a rare example of a nearly two-dimensional Heisenberg antiferromagnet on a triangular lattice. Magnetic resonance spectra and magnetization curves reveal that the system has a layered spin structure with six magnetic sublattices. The sublattices within a layer are arranged in a triangular manner with the magnetization vectors 120 degree apart. The H-T phase diagram, containing at least five different magnetic phases is constructed. In zero field, RbFe(MoO4)2 undergoes a phase transition at T_N=3.8 K into a non-collinear triangular spin structure with all the spins confined in the basal plane. The application of an in-plane magnetic field induces a collinear spin state between the fields H_c1=47 kOe and H_c2=71 kOe and produces a magnetization plateau at one-third of the saturation moment. Both the ESR and the magnetization measurements also clearly indicate an additional first-order phase transition in a field of 35 kOe. The exact nature of this phase transition is uncertain.Comment: 9 pages incl 11 figure

ACTION OF 1-VINYL-1,2,4-TRIAZOLE COPOLYMER WITH N-VINYLPIROLIDONE AND METAL-CONTAINING NANOCOMPOSITES ON FUNCTIONAL STATE OF PHAGOCYTIC CELLS

The creation of immuno-biological drugs to increase the effectiveness of specific immunotherapy and immunoprophylaxis is a current trend in medicine to date. Therefore, the search and development of new safe and effective artificial bioorganic complexes (immunomodulators) capable of stimulating individual responses of immune system to reduce infectious morbidity is an important area of research. At the moment, such promising preparations can be considered water-soluble polymeric materials and organo-inorganic polymer nanocomposites with nanoparticles of various metals which possess immunomodulating and bactericidal properties. The study results of the effects of 1-vinyl-1,2,4-triazole copolymer with N-vinylpyrrolidone and nanocomposites based on it with gold and silver nanoparticles on acute toxicity and functional state of immunophagocytic cells of experimental animals, as well as the production of IFN-γ, TNF-α and IL-4 by human blood lymphocytes are represented in this article. It was established that the tested preparations do not cause increase in body temperature, decrease in mass and death of animals. It was shown that they also have the multidirectional action on cytokine production by human blood cells in vitro, the ability to increase activity of оxidative stress-related enzymes and antioxidant protection of phagocytes. The data obtained by us allow to explain the need for further investigation of the actions of nanocomposites and copolymer in vitro and in vivo

Assessment of Toxic and Immunoadjuvant Properties of Nanocomposites

Introduction. The current direction in medicine is the creation of immunobiological preparations to increase the effectiveness of specific immunotherapy and immunoprophylaxis, containing immunomodulators in their composition. These natural or synthetic substances can have a regulating effect on the immune system. At present, water-soluble organic-inorganic polymeric materials with nanoparticles of various chemical substances with bactericidal and immunomodulating properties can serve as such promising compounds.The aimof the work is to study the acute toxicity of polymer nanocomposites based on 1-vinil-1,2,4-triazole copolymer with N-vinylpyrrolidone with silver, gold and selenium nanoparticles and their effect on the functional state of immune system cells in vitro.Materials and methods.The study of acute toxicity was performed on outbred white mice. The activity of superoxide dismutase and glucose-6-phosphate dehydrogenase were studied in guinea pig peritoneal macrophages. The study of spontaneous and nanocomposite-induced production of pro- (interferon gamma and tumor necrosis factor alpha) and anti-inflammatory (interleukin-4) cytokines by blood cells was carried out using clinical material obtained from volunteers using the ELISA method. Results. It has been established that nanocomposites with silver and gold nanoparticles do not cause the death of white mice, their temperature increase and body weight decrease. The average lethal dose for a nanocomposite with selenium nanoparticles was determined as 1 gram per 1 kilogram of animal mass. It was shown that the tested nanocomposites have a stimulating effect on the production of cytokines by human blood cells in vitro. It was established that a nanocomposite with selenium nanoparticles increases the activity of superoxide dismutase and glucose-6-phosphate dehydrogenase. A comparative analysis of their actions with the actions of commercial preparations of biological origin, with immunomodulatory properties.Conclusion. The data obtained allow us to substantiate the need for further research on the effects of nanocomposites based on 1-vinyl-1,2,4-triazole copolymer with N-vinylpyrrolidone with silver, gold and selenium nanoparticles on the macroorganism in both in vitro and in vivo conditions