Relativistic Model of Detonation Transition from Neutron to Strange Matter

We study the conversion of neutron matter into strange matter as a detonation wave. The detonation is assumed to originate from a central region in a spherically symmetric background of neutrons with a varying radial density distribution. We present self-similar solutions for the propagation of detonation in static and collapsing backgrounds of neutron matter. The solutions are obtained in the framework of general relativistic hydrodynamics, and are relevant for the possible transition of neutron into strange stars. Conditions for the formation of either bare or crusted strange stars are discussed.Comment: 16 pages, 4 figures. Submitted to IJMP

Metal Oxide Porous Coatings for Implantant Materials

The paper presents the results of survey, dedicated to synthesis of metal oxide coatings on porous materials applied for implant surgery (stainless steel 12X18H9T, titanium alloy and high-purity niobium VT5). This article examines kinetic features of electrochemical formation of anodic oxide coatings on steel, niobium and titanium. It is shown that for steel anodic treatment method does not provide a reliable surface passivation (no current decay, the surface indicates the transition to the passive state).Analysis of polarization dependences obtained on niobium and titanium in electrolytes with an activator (F-), indicates surface passivation (current slump), and at potentials above 2 on the surface of a transition curves in transpassive state (as evidenced by the current increase). Consequently, it can be concluded that presence of F- results surface activation of titanium and niobium electrode (F- oxide reacts to form water-soluble complexes) that promotes nucleation and formation of pores of the porous structure of the oxide coating.SEM results verify the presence of self-organized porous oxide film synthesized on titanium and niobium in solutions containing F-

Positronium oscillations to Mirror World revisited

We present a calculation of the branching ratio of orthopositronium decay into an invisible mode, which is done in the context of Mirror World models, where ordinary positronium can disappear from our world due to oscillation into its mirror twin. In this revision we clarify some formulas and approximations used previously, correct them at some places, add new effects relevant for a feasible experiment and finally perform a combined analysis. We include into consideration various effects due to external magnetic and electric fields, collisions with cavity walls and scattering off gas atoms in the cavity. Oscillations of the Rydberg positroniums are also considered. To perform a numerical estimates in a realistic case we wrote computer code, which can be adopted in any experimental setup. Its work is illustrated with an example of a planned positronium experiment within the AEgIS project.Comment: 23 pages, 4 figures, typos corrected, references added, published versio

Metal Oxide Porous Coatings for Implantant Materials

The paper presents the results of study of synthesis of metal oxide coatings on porous materials used in implant surgery (stainless steel 12X18H9T, titanium alloy and high-purity niobium VT5). It is shown the prospects of electrochemical anodizing method for the purpose of formation of porous, corrosion-resistant and biologically inert coatings, which significantly improve morphological structure of materials

New insights from old cosmic rays: A novel analysis of archival KASCADE data

Cosmic ray data collected by the KASCADE air shower experiment are competitive in terms of quality and statistics with those of modern observatories. We present a novel mass composition analysis based on archival data acquired from 1998 to 2013 provided by the KASCADE Cosmic ray Data Center (KCDC). The analysis is based on modern machine learning techniques trained on simulation data provided by KCDC. We present spectra for individual groups of primary nuclei, the results of a search for anisotropies in the event arrival directions taking mass composition into account, and search for gamma-ray candidates in the PeV energy domain.Comment: Proceedings of the 37th International Cosmic Ray Conference (ICRC2021), 12-23 July 2021, Berlin, Germany - Onlin

Improving the components of health-saving technologies in a modern university

Nowadays, one of the important missions of higher educational institutions is the organisation and introducing students to a culture of health. The purpose of this study is to propose a strategy for the development of health-saving technologies by implementation of project activities into the educational process based on the Physical Education Department at the State University of Management for the formation of competencies in the chosen professional activity. The sociological survey was carried out among students at the State University of Management. The questionnaires included questions on students’ attitudes towards physical culture as an integral component of a healthy lifestyle. The degree of interest of the respondents in project activities in general and on the basis of the Department of Physical Education at the university, in particular, to improve the acquired professional competences was determined. The results of the study point to the need to modernise approaches to the formation of healthy lifestyle values, including the organisation of physical culture events, the development of a marketing plan to attract mass attention to the sports life of the university, where the main role is given to self-education and the realisation of the individual’s potential through active participation in university sporting life