Basic principles of postgrowth annealing of CdTe:Cl ingot to obtain semi-insulating crystals

The process of annealing of a CdTe:Cl ingot during its cooling after growth was studied. The annealing was performed in two stages: a high-temperature stage, with an approximate equality of chlorine and cadmium vacancy concentrations established at the thermodynamic equilibrium between the crystal and vapors of volatile components, and a low-temperature stage, with charged defects interacting to form neutral associations. The chlorine concentrations necessary to obtain semi-insulating crystals were determined for various ingot cooling rates in the high temperature stage. The dependence of the chlorine concentration [Cl+Te] in the ingot on the temperature of annealing in the high-temperature stage was found. The carrier lifetimes and drift mobilities were obtained in relation to the temperature and cadmium vapor pressure in the postgrowth annealing of the ingot.Comment: 6 pages, 6 figure

Investigation into the operation of an autothermal two-section subbituminous coal fluidized bed gasifier

Using a newly developed experimental setup, the features and advantages of an autothermal single-casing atmospheric subbituminous coal fluidized bed air-blown gasifier, combining a combustion and gasification section, and mixing the dispersed phase (inert material, char) and heat exchange between them through an annular transfer device, have been revealed. To increase the efficiency of the gasifier, an experimental-computational method was developed find the conditions for optimal operation, combining changing the annular flow’s geometry and regulating the primary air for gasification. A simple and reliable multizone thermodynamic calculation model makes it possible to predict the composition of char and syngas in the gasification section with acceptable accuracy. This method confirmed that a two-section fluidized bed gasifier can provide efficient gasification of solid fuels and is suitable for use in small-scale cogeneration plants. Syngas with a heating value of 3.6–4.5 MJ/m3 and CGE of 38.2%–42.3% was obtained in the experimental setup without optimizing the primary air flow rate. With optimization, the indicators increased to the heating value of syngas of 5.20–5.34 MJ/m3 and CGE of 42.5%–50.0%. With heat regeneration of 0.8, CGE increases to 70%. © 2023, The Author(s).Ministry of Education and Science of the Russian Federation, MinobrnaukaThe research funding from the Ministry of Science and Higher Education of the Russian Federation (Ural Federal University Program of Development within the Priority-2030 Program) is gratefully acknowledged

Three-dimensional localized coherent structures of surface turbulence. III Experiment and model validation

The paper continues a series of publications devoted to the 3D nonlinear localized coherent structures on the surface of vertically falling liquid films. The work is primarily focussed on experimental investigations. We study: (i) instabilities and transitions leading to 3D coherent structures; (ii) characteristics of these structures. Some nonstationary effects are also studied numerically. Our experimental results, as well as the results of other investigators, are in a good agreement with our theoretical and numerical predictions.Comment: 42 pages, 15 figure

Ragweed pollen rain impact on allergy rate and severity in Krasnodar: a three-year non-randomised controlled study

Background. The main hay fever agent in Krasnodar Krai is ragweed pollen (Ambrosia gen.). An important alerting guide for medical practitioners and allergic citizens is the seasonal anthetic calendar and pollen peak times.Objectives. Obtaining of relevant data on ragweed pollen air contamination rate in Krasnodar in a three-year-dynamics (2018–2020) to estimate the anthetic activity correlation with abiotic and anthropogenic factors and the role of pollen indicators in allergic morbidity.Methods. We surveyed the daily average ragweed pollen values in Krasnodar air. Allergic medical visits were analysed in terms of the ragweed anthetic activity and pollen air contamination of the city.Results. A maximal daily average ragweed pollen peak occurs in August: 663.35 p.g./m3 in 2018, 209.89 p.g./m3 in 2019, 80.62 p.g./m3 in 2020. Numbers of medical visits for pollinosis per a selected municipal medical facility: 314 in 2018, 335 in 2019 and 146 in 2020, with a peak period in September--October. Analyses of the air pollution impact on ragweed pollen production revealed a correlation between the pollen rate and values of CO (correlation coefficient r-0.356), NH3 (r-0.198) and dust pollution (r-0.361) in July, August, September and October 2018–2020.Conclusion. Analyses of climatic factors uncovered clear patterns: strongest anthesis corresponds to minimal humidity (<60%), the pollen grain content diminishes with lower humidities dropping to minimal with precipitations and increases at temperatures 20 °C and above. No significant dependency was observed between air pollution and the allergic pollen content. Anthesis in ragweed moderately correlates with the rate of medical visits

The fate of the scientist as a reflection of the epoch: in memory of the first rector of the Kuban State Medical University Nikolai F. Melnikov-Razvedenkov

The paper analyzes the life and professional journey of Nikolai F. Melnikov-Razvedenkov, an outstanding scientist, doctor, and professor, as a reflection of Russian history from the end of the 19th century till the first quarter of the 20th century. The study identifies the role of Nikolai F. Melnikov-Razvedenkov in the development of medical science and the establishment of medical education in the Kuban region. The analysis was conducted with the involvement of archival records, personal correspondence, and scientific works of Nikolai F. Melnikov-Razvedenkov. To solve research problems, the authors used historical descriptive, comparative historical, problem-based chronological, biographical methods, and the method of monographic description. It is shown that the scientist’s fate mirrors the cultural and historical era experienced by the country. The authors define the exclusive role of Nikolai F. Melnikov-Razvedenkov in the establishment of the Kuban Medical Institute. His life path helped reveal the inviolability of medical ethics based on mercy, dedication to the profession, and willingness to serve people. Even in the situation of social upheaval Nikolai F. Melnikov-Razvedenkov found the meaning of his life in scientific work and helping people. His example will allow the modern generation of doctors to gain a greater understanding of the essential purpose of their work

Stable radiation-controlling boundary conditions for the generalized harmonic Einstein equations

This paper is concerned with the initial-boundary value problem for the Einstein equations in a first-order generalized harmonic formulation. We impose boundary conditions that preserve the constraints and control the incoming gravitational radiation by prescribing data for the incoming fields of the Weyl tensor. High-frequency perturbations about any given spacetime (including a shift vector with subluminal normal component) are analyzed using the Fourier-Laplace technique. We show that the system is boundary-stable. In addition, we develop a criterion that can be used to detect weak instabilities with polynomial time dependence, and we show that our system does not suffer from such instabilities. A numerical robust stability test supports our claim that the initial-boundary value problem is most likely to be well-posed even if nonzero initial and source data are included.Comment: 27 pages, 4 figures; more numerical results and references added, several minor amendments; version accepted for publication in Class. Quantum Gra

Patient routing and process approach implementation for regional oncology service

Background. Cancer care involves a multidisciplinary approach to diagnosis and treatment of patients. A complex interaction of actors in the deployment of oncology services dictates usage of modern management technologies for improving the quality and efficiency of patient care through processes optimisation.Objectives. Provision of recommendations for patient routing based on research into the oncology service inter-level information exchange, integration of the process approach and electronic services. The lack of a unified information space with a regional oncology service has been explained. Measures are proposed for the patient routing optimisation as part of establishing a unified digital oncology service circuit.Methods. The oncology service was effectively remodelled through functional and information engineering of electronic services and the process management integration to establish a horizontal decision flow between facilities and employees on a process level bypassing the supervisor coordination. Statistical approaches were used to analyse the oncological patient population.Results. The following electronic services have been implemented: specialised patient referral routing, telemedicine and teleradiology. A comprehensive information framework has been created comprising medical, laboratory and radiological information subsystems integrated through regional electronic services of the unified state healthcare information platform. The goals, objectives, general principles, architecture and expected social economic impact on healthcare of Krasnodar Krai have been defined.Conclusion. Use of electronic services ensures an improved quality of specialised care and effective routing of patients. We perceive prospects of the integrated information platform in the extension and improvement of its subsystems’ functionality and content, sourcing more data providers and the circuit expansion to the federal and regional levels