Antiproton-Hydrogen annihilation at sub-kelvin temperatures

The main properties of the interaction of ultra low-energy antiprotons ($E\le10^{-6}$ a.u.) with atomic hydrogen are established. They include the elastic and inelastic cross sections and Protonium (Pn) formation spectrum. The inverse Auger process ($Pn+e \to H+\bar{p}$) is taken into account in the framework of an unitary coupled-channels model. The annihilation cross-section is found to be several times smaller than the predictions made by the black sphere absorption models. A family of $\bar{p}H$ nearthreshold metastable states is predicited. The dependence of Protonium formation probability on the position of such nearthreshold S-matrix singularities is analysed. An estimation for the $H\bar{H}$ annihilation cross section is obtained.Comment: latex.tar.gz file, 22 pages, 9 figure

Competing anisotropy in the (TmxPr1-x)2Fe17 system

The magnetization curves of magnetically aligned finely powdered samples of the (TmxPr1-x)2Fe17 compounds have been measured at 4 K. The easy magnetization axis is oriented in the basal plane or along the hexagonal axis for the compounds with x = 0-0.3 and 0.7-1, respectively. This is because of the absence of magnetic ordering in the Tm and Pr subsystems in these ranges, respectively, and because of competing anisotropy of the subsystems. For the compositions with x = 0.4-0.6, both rare-earth subsystems are magnetically ordered and the easy magnetization axis is oriented between the basal plane and the hexagonal axis. The critical fields of FOMPs decrease quickly as the Pr or Tm content decreases in the ranges 0-0.3 and 0.7-1, respectively. The magnetization anisotropy also diminishes as the Tm content becomes smaller than x = 0.7. No influence of the intrinsic microdeformations on the magnetization of the compounds was detected. © 2018 The Authors, published by EDP Sciences

Morphological and structural features of the CdxPb1−xS films obtained by CBD from ethylenediamine-citrate bath

The calculating of ionic equilibria in the system «Pb(CH3COO)2 - CdCl2 - Na3C6H5O7 - ‎(NH3)2(CH2)2 - N2H4CS» allowed us to find conditions and concentration regions of PbS and CdS co-deposition. The determined conditions provided the CBD obtaining of CdxPb1−xS (0 ≤ x ≤ 0.033) substitutional solid solutions films with a cubic structure B1 (space group Fm ) with the grains preferred orientation (200). We established the evolution of the surface morphology of the synthesized films from cubic crystallites to hierarchical structure of globular aggregates by scanning electron microscopy. A quantitative analysis of diffraction patterns showed a decrease of microstrains in CdxPb1−xS films by a about factor of 3 with an increase of the cadmium chloride concentration in the reaction mixture from 0.005 to 0.14 mol/l. The excess of the cadmium content, established by EDX analysis, in the studied films as compared to its content in the solid solution is associated with the additional formation of the amorphous CdS phase up to 72 mol %.A Corrigendum is available for this article at https://doi.org/10.15826/chimtech.2021.8.2.12

Low-energy Antiproton Interaction with Helium

An ab initio potential for the interaction of the neutral helium atom with antiprotons and protons is calculated using the Born-Oppenheimer approximation. Using this potential, the annihilation cross section for antiprotons in the energy range 0.01 microvolt to 1 eV is calculated.Comment: 13 pages, 7 figures, LaTe

Features of prevention of deviant behavior of students by means of sports and recreational activities

The results of the study showed the necessity and effectiveness of the use of means of physical culture and recreational activities in the prevention of students' deviant behavior. In the process of use of means of physical culture and recreational activities, attention was focused on getting pleasure from students in order to interrupt their destructive and stereotypical behavioral behavior programs, for which all forms of physical exercises were used aimed at emotionally active rest, entertainment, getting satisfaction from motor activity and comfortable psycho-emotional envi-ronment in the classroo

REGULATION OF PERIPHERAL B-LYMPHOCYTE DIFFERENTIATION IN RECURRENT MISCARRIAGE

The important role of immune disorders in recurrent miscarriage has been proven. Clarification of the character of B-lymphocyte differentiation and its regulation factors in women with threatened miscarriage and recurrent miscarriage in history is an urgent problem, since it will reveal the immune mechanisms of the pathogenesis of this pathology. Purpose: to establish the features of B-lymphocyte differentiation and factors of its regulation in women with a history of recurrent miscarriage and threatening spontaneous miscarriage at the time of examination.Were examined pregnant women aged 18-40 years at a gestation period of 5-12 weeks. The main group consisted of 60 pregnant women with a threatening spontaneous miscarriage at the time of examination and a history of recurrent miscarriage. As a control, 35 pregnant women with uncomplicated pregnancy were examined. The comparison group consisted of 25 primary pregnant women with threatened spontaneous miscarriage at the time of examination. The material for the study was peripheral venous blood. Subpopulations of B-lymphocytes CD19+, CD19+ IgD+, CD20+IgM+, CD20+IgG+ were determined by flow cytometry; CD19+CD20- CD38+, CD19+CD27- , CD19+CD27+. Serum levels of BAFF and APRIL were assessed by enzyme-linked immunosorbent assay.In the main group, an increase in the proportion of B-cells, CD20+IgM+-lymphocytes and memory cells was recorded in the peripheral blood, along with a decrease in the level of naive cells and plasma cells. In the comparison group, an increase in the proportion of immature IgM+B-cells, circulating memory cells, along with a decrease in naive B-lymphocytes, was registered. in the main group there was a pronounced decrease in the serum BAFF level compared with the control and comparison groups. Analysis of the APRIL content showed a pronounced downward trend in groups with threatened miscarriage relative to healthy pregnant women. Thus, threatening habitual and sporadic miscarriages were associated with a shift in the differentiation of B-lymphocytes towards immature forms and a lack of regulatory influence of BAFF and APRIL, which is reflected in the disruption of B-cell homeostasis and weakening of humoral effector mechanisms at the systemic level. The revealed changes may indicate a single mechanism for the development of a threatening spontaneous miscarriage, the severity of which increases with repeated loss of pregnancy. These changes can lead to an increase in effector cytotoxic mechanisms and an increase in proinflammatory cytokines, which can lead to the development of damaging reactions in the fetoplacental complex, which can be reflected in the clinical picture of the threat of termination of pregnancy

Light-emitting-diode Fourier-transform spectroscopy of HD16O between 11200 and 12400 cm-1

The absorption spectrum of monodeuterated water, HDO has been investigated between 11200 and 12400 cm-1. The spectrum has been recorded using IFS-125M interferometer with spectral resolution of 0.05 cm-1. For measurements White’s-type cell were used. The bright light emitting diode (LED) EDEI-1LS3-R was applied as a source of radiation. Signal to noise ratio was about 104. The spectral line parameters - line positions, intensities and half-widths were obtained by least square fitting. As a result of the spectrum analysis the line list containing more than 1500 lines was created. The spectral line parameters have been compared with the previous measured and calculated data. © (2015) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only

A quantum mechanical description of the experiment on the observation of gravitationally bound states

Quantum states in the Earth's gravitational field were observed, when ultra-cold neutrons fall under gravity. The experimental results can be described by the quantum mechanical scattering model as it is presented here. We also discuss other geometries of the experimental setup which correspond to the absence or the reversion of gravity. Since our quantum mechanical model describes, particularly, the experimentally realized situation of reversed gravity quantitatively, we can practically rule out alternative explanations of the quantum states in terms of pure confinement effects.Comment: LaTeX, 10 pages, 4 figures, v2: references adde

GRANIT project: a trap for gravitational quantum states of UCN

Previous studies of gravitationally bound states of ultracold neutrons showed the quantization of energy levels, and confirmed quantum mechanical predictions for the average size of the two lowest energy states wave functions. Improvements in position-like measurements can increase the accuracy by an order of magnitude only. We therefore develop another approach, consisting in accurate measurements of the energy levels. The GRANIT experiment is devoted to the study of resonant transitions between quantum states induced by an oscillating perturbation. According to Heisenberg's uncertainty relations, the accuracy of measurement of the energy levels is limited by the time available to perform the transitions. Thus, trapping quantum states will be necessary, and each source of losses has to be controlled in order to maximize the lifetime of the states. We discuss the general principles of transitions between quantum states, and consider the main systematical losses of neutrons in a trap.Comment: presented in ISINN 15 seminar, Dubn