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A new experiment aimed at studying radiative neutron decay is proposed. The respective experimental procedure reduces to measuring the time spectra of triple coincidences of the emitted photon, beta electron, and recoil proton along with the spectrum of double coincidences of ordinary decay products. By means of this procedure, we were able to measure for the first time the branching ratio for radiative neutron decay, BR = (3.2 ± 1.6) × 10-3 (at a confidence level of C.L. = 99.7%, the photon energy being in excess of 35 keV) in 2005 at our old setup. The average value of this branching ratio was greater by a factor of 1.5 than its theoretical counterpart calculated on the basis of the Standard Model. However, we cannot state that we have seen a deviation fromthe Standard Model prediction since the experimental error was quite large in that experiment. The present study is devoted to implementing, by means of the popular Geant4 code package, a computer analog of the respective experiment at a new facility. Our calculations reveal that the resulting geometric-factor values make it possible to a accumulate, in a live experiment, a data sample sufficient for measuring the above branching ratio to a precision of a few percent. [ABSTRACT FROM AUTHOR]

Improvement of plasma deposition wear-resistant coatings technology is demonstrated. At the same time, special attention is paid to one of the most important parameters, i.e., thickness of a functional layer, since when using plasma deposition methods it has a significant impact on coating quality, as well as functionality and productivity of the process. Based upon planning an experiment, mathematical models are developed that make it possible to establish a relationship between coating thickness and plasma spraying process production parameters. Results of analyzing the dependences obtained show that coating thickness is most affected by plasma torch arc current strength. [ABSTRACT FROM AUTHOR]

Viral hepatitis type A is an acute infectious disease, occupying 75% of all viral hepatitis. Purpose of the study was to investigate three outbreaks, of viral hepatitis A in the municipalities of Stara Zagora region, from 09.2019-03.2020 in schools and kindergartens. Methods: We investigated all cases from viral hepatitis A, for the municipalities of Bratya Daskalovi-26, Hrishteni-19, Galabovo-21. A retrospective analysis and descriptive epidemiological methods have been used. Results: The gender distribution shows that men were affected in 56% and women in 44%. The children in the age group of 5-9 years - 49%, as well as of 1 - 4 years - 19.7% are most ill. The peak in the development of the outbreaks is in December 2019 (18%) and January 2020 (48%), which lasts until March with the so-called "Epidemic tail". Contact persons were not covered by the hepatitis A vaccine. The faecal-oral mode of transmission of infection has been proven. Specialized companies were engaged for the activities of current and final disinfection. Health educational activities aimed at improving hygiene habits have been carried out. Conclusion: To prevent the outbreaks the cases have to be timely reported; Early examination of contact persons; Applications of a vaccine on the contact persons. [ABSTRACT FROM AUTHOR]