7 research outputs found

    Relationship between TEC jumps and auroral substorm in the high-latitude ionosphere

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    The influence of an auroral substorm on the total electron content (TEC) jumps and cycle slips on Global Positioning System (GPS) at high-latitudes is studied. For the first time, optical data from the all-sky imager, as well as interplanetary magnetic field and magnetometer data are used to complete the analysis of the slips occurrence and to monitor the substorm evolution. Two types of slips are considered: (i) instrumental slips including losses in the measured phase of the GPS signal and (ii) sharp TEC variations (TEC jumps) It is demonstrated that the jumps in TEC determined from the GPS signals are mainly related to the auroral particle precipitation that normally occurs during geomagnetic substorms in the polar ionosphere. The GPS frequency L2 is consistently subject to more slips than frequency L1 both for quiet and disturbed conditions. The probability of TEC jumps is higher than for cycle slips in phase at frequencies L1 and L2. The maximum of TEC jumps is observed during the recovery phase of the auroral substorm. Our findings are based on a data set obtained for a particular event. A generalization of the obtained numerical estimates to other events requires additional research and further analysis

    A Panchromatic Cyclometalated Iridium Dye Based on 2-Thienyl-Perimidine

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    Though 2-arylperimidines have never been used in iridium(III) chemistry, the present study on structural, electronic and optical properties of N-unsubstituted and N-methylated 2-(2-thienyl)perimidines, supported by DFT/TDDFT calculations, has shown that these ligands are promising candidates for construction of light-harvesting iridium(III) complexes. In contrast to N-H perimidine, the N-methylated ligand gave the expected cyclometalated μ-chloro-bridged iridium(III) dimer which was readily converted to a cationic heteroleptic complex with 4,4′-dicarboxy-2,2′-bipyridine. The resulting iridium(III) dye exhibited panchromatic absorption up to 1000 nm and was tested in a dye-sensitized solar cell

    Development and Implementation of Decision Support Systems for Blast Smelting Control in the Conditions of PrJSC “Kamet-Steel”

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    This article presents a description of three decision support systems (DSS) in the mode of an adviser to the technological personnel of blast furnaces (BF), which were implemented by the Iron and Steel Institute of Z.I. Nekrasov (Dnipro, Ukraine) or underwent pilot testing as part of the automated control system of the BF shop of PrJSC “Kamet-steel” (Kamianske, Ukraine). The first DSS for managing the thermal state was implemented in 2021; it includes the entire list of information necessary for personnel in a convenient and compact form, generates recommendations in case of technology deviations, and, in the case of incorrect actions by the personnel, signals the need for correct actions. The main recommendations from the DSS are to correct the raceway adiabatic flame temperature, coke consumption when its characteristics are specified in (indicators of strength and abrasion, fractional composition, humidity, ash and sulfur), and ore load change. Using the system allows both reducing the specific coke consumption and preventing unplanned downtime. The second DSS for controlling the distribution of fuel additives over air tuyeres is based on information on thermal loads determined on water-cooled elements of tuyere tools. The main recommendations from the DSS are to adjust the amount of injected pulverized coal fuel on individual tuyeres in order to ensure a uniform distribution of the raceway adiabatic flame temperature around the circumference of the BF and, as a result, the energy efficiency of BF smelting. The third DSS for adjusting the parameters of the charging mode is based on information from the means of controlling the temperatures of the gas flow above the surface of the charge in the BF. The functioning of this DSS is based on determining the reference curves for the distribution of the gas flow along the BF radii, corresponding to the minimum consumption of coke and maximum productivity, and on the search for solutions by direct and iterative optimization methods, which allow one, by adjusting the charging parameters, to ensure a rational distribution of charge materials and gas flow in the BF

    Safety and Immunogenicity of Inactivated Whole Virion COVID-19 Vaccine CoviVac in Clinical Trials in 18–60 and 60+ Age Cohorts

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    We present the results of a randomized, double-blind, placebo-controlled, multi-center clinical trial phase I/II of the tolerability, safety, and immunogenicity of the inactivated whole virion concentrated purified coronavirus vaccine CoviVac in volunteers aged 18–60 and open multi-center comparative phase IIb clinical trial in volunteers aged 60 years and older. The safety of the vaccine was assessed in 400 volunteers in the 18–60 age cohort who received two doses of the vaccine (n = 300) or placebo (n = 100) and in 200 volunteers in 60+ age cohort all of whom received three doses of the vaccine. The studied vaccine has shown good tolerability and safety. No deaths, serious adverse events (AEs), or other significant AEs related to vaccination have been detected. The most common AE in vaccinated participants was pain at the injection site (p p 1:256, the rate of fourfold increase in nAB levels was below 45%; the participants who were seropositive at screening of the 2nd vaccination did not lead to a significant increase in nAB titers. In conclusion, inactivated vaccine CoviVac has shown good tolerability and safety, with over 85% NT seroconversion rates after complete vaccination course in participants who were seronegative at screening in both age groups: 18–60 and 60+. In participants who were seropositive at screening and had nAB titers below 1:256, a single vaccination led to a fourfold increase in nAB levels in 85.2% of cases. These findings indicate that CoviVac can be successfully used both for primary vaccination in a two-dose regimen and for booster vaccination as a single dose in individuals with reduced neutralizing antibody levels

    The Institutional Foundations of the Digital Economy in the 21st Century/ Elena G. Popkova, Artem Krivtsov, Aleksei V. Bogoviz.

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    In English.The development of the Digital Economy has been a landmark breakthrough for economic systems in the 21st century, as it opens up opportunities for the full-scale implementation of new digital technologies and the optimization of economic activities. While the conceptual essence and specific features of the digital economy are described in detail in the existing literature, the practical foundations of its formation are poorly studied. In this book, the digital economy is studied from the perspective of neo-institutional economic theory. This allows for the tracking of the process of formation (institutionalization) of the digital economy, determining the basic institutions that are necessary for its formation and that exist in modern economic practice, and analyzing scenarios for the future development of the digital economy in the 21st century.Frontmatter -- Contents -- Digital Economy in the 21 Century: An Introduction to the Institutional Approach -- Part I: The Scientific Concept of the Digital Economy in the 21st Century -- 1 Digital Economy as a Modern Type of Economic System -- 2 “Digitalization”- Overcoming Institutional Barriers -- 3 Development of the Information Technologies Sector in Latvia under Globalization -- 4 The Principles of Functioning and Priorities of Development of the Digital Economy -- 5 Classification of Breakthrough Digital Technologies and the Perspectives of Their Application in Economy -- Part II: The Process of Digital Economy Institutionalization in the 21st Century -- 6 The Essence and Logic of the Process of Sectorial Markets' Digital Transformation -- 7 The Current Tendencies of Economy Digitalization in Developed and Developing Countries -- 8 The Main Stages of the Digital Modernization of Economy -- 9 Implementation of Cluster Initiatives in the Digital Sphere as a Tool of Digital Entrepreneurship's Institutionalization -- 10 Institutions of Support for Digital Entrepreneurship: Special Economic Zones, Innovative Networks and Technological Parks -- Part III: Meso-Level Institutions of the Digital Economy in the 21st Century -- 11 Digitalization of Regional Economy: Problems and Perspectives -- 12 The Institutional Model of the Digital Economy Creation in a Modern Region -- 13 Managing a Modern Region Based on Digital Technologies -- Part IV: Macro-Level Institutions of the Digital Economy in the 21st Century -- 14 State Institutional Regulation of Economy Digital Modernization -- 15 The Role of Financial Institutions in Supporting the Digital Economy -- 16 Digital Economy of the 21st Century: A View from the Positions of Developed and Developing Countries -- Part V: The Global Institutions of the Digital Economy in the 21st Century -- 17 International Trade in the Digital Sphere: Barriers and Prospects for Development -- 18 The Existing and Perspective International Institutions for Supporting Digital Transformation of Economy -- 19 The Scientific and Methodological Approach to Provision and Evaluation of the Digital Economy's Global Competitiveness -- 20 The Strategy of Optimal Development of the Digital Economy: A View from the Positions of Game Theory -- 21 The Institutional Model of Well-Balanced and Sustainable Digital Economy -- 22 The Institutional Mechanism of Managing the Digital Economy's Development -- Part VI: Case Studies of Institutions of the Digital Economy in the 21st Century -- 23 Problems and Prospects of Economic Cooperation Between Russia and Mexico -- 24 Innovative Critical Success Factors for Public - Private Partnerships (PPP) in Infrastructure Projects of Developing Countries. A Case of Zambia -- 25 Prediction Mechanism of the Territorial Socio-Economic Processes in Formation of the Information Systems -- 26 Specific Economic Security Regulations in the Context of Pathological Crises of Digital Transformation of Agricultural Organizations -- Conclusion: Institutional Perspectives of the Digital Economy's Development in the 21st Century -- List of Figures -- List of Tables -- Index.1 online resource (XI, 258 p.)
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