An empirical foF2 model was constructed for the winter high-latitude ionosphere taking into account the structure of the ionization trough. This model describes the trough position and its shape in terms of longitudinal-latitudinal variations in foF2 in geographic latitude intervals of 40-85 degrees N and 40-85 degrees S. The model is valid for November to February in the Northern hemisphere and May-August in the Southern hemisphere. The simulation describes quiet geomagnetic conditions (Kp from 0 to 3+ for all local time (LT) and universal time (UT) hours at any solar activity level in the interval F10.7 = 70-200 s.f.u. The model is based on the Cosmos-900, Interkosmos-19 and CHAMP satellite data. The radio occultation observation data obtained from the GRACE, CHAMP and COSMIC/FORMOSAT experiments were partially used. The International Reference Ionosphere (IRI) was also used; thus, the ground-based station data were indirectly considered. Within the model framework, the variations in the trough minimum position with longitude and local time were identified and studied in detail. The latitudinal and longitudinal variations in foF2 were also revealed and investigated. The constructed model more adequately reproduces variations in foF2 than the IRI-2016 model. The new model is available on the IZMIRAN website: http://www.izmiran.ru/ionosphere/sm-mit/. (c) 2021 COSPAR. Published by Elsevier B.V. All rights reserved.

The paper presents two approaches for the traditional two-point ray-tracing problem in anisotropic inhomogeneous ionosphere: the homing-in method based on global optimization and the direct approach based on Fermat's principle. While in most cases both methods are capable of finding all rays connecting the given transmitter and receiver, the direct approach tends to be more stable in locating highly divergent high rays, but the homing-in method usually offers a better tradeoff between the accuracy and computational cost of the low ray calculations. Joint application of the presented methods provides valuable means for solving applied problems of radio communication forecast and ionospheric models validation and adaptation.

The article considers and analyzes the parameters of physical wear and tear of building structures of school buildings, built over the past 50-70 years. The main content of the research is the analysis of materials from surveys of municipal institutions of secondary education in the Rostov region. The paper describes the most common structural schemes of buildings and features of supporting structures. The characteristic deformations and damages of the bearing and enclosing building structures of school buildings are considered and methods for their elimination are proposed. The significant social role of the safety of school buildings and their technical condition for the secondary education system and, as a consequence, the stability of society is noted.

The article is devoted to the development of the school education system in Russia and planning decisions of school buildings from the beginning of the 19th century to the present. The issues of urban planning policy and the development of trends in the design of school buildings are touched upon. The advantages, expediency and prospects of using the design solutions adopted in Finland for secondary schools are considered. The influence of foreign design solutions on the development of school buildings in Russia is shown. The factors that should be taken into account when assessing the architectural and planning solutions of modern school buildings are considered.

Global optimization of phase distance functional is a promising approach to the multipath problem of the point-to-point ionospheric ray tracing. The approach is involves systematic algorithm where all relevant rays between the fixed points are found one after another in a systematic manner, without the need to provide an accurate initial estimation for each solution. In particular for each 10-cal ray searching the direct variational method is applied. The global optimization is applied to a point-to-point ionospheric ray tracing, where the modeled ionosphere is three-dimensional inhomogeneous medium.

Abstract The article deals with the issues of sustainable development, which should meet the needs of the present and future generation – the environmental safety of urban systems including socio-economic and intellectual impact on human processes occurring in the environment, preservation and improvement of the quality of life. Rational use of natural resources is the main task of the modern social state. Ideal zoning of territories in and around the city should primarily be carried out in such a way that gradually, as the distance from the city increases, so the environment becomes cleaner and gradually nature would become absolutely virgin. For this purpose the spatial structure of ecological skeleton of settlement is offered. One of the directions of ensuring ecological safety of construction and municipal economy is ecorestoration of landscapes, which includes restoration of properties: of soil, water, atmosphere, relief and lithosphere; flora and fauna. It may encompass returning the contaminated landscape or its separate components to a state close to the natural one. The main problems of ecology of urban systems are revealed. The generalizing coefficient of influence of city (technical) systems on environment is offered including an assessment of morphological, technical, hydrotechnical, hydrobiological and biological changes of flora and fauna, water quality in adjacent water objects (water intakes); ecotoxicological and social changes; sanitary and hygienic diseases; effects of space-related changes and emergencies.

The modern building materials market places high demands on heat-insulating and heat-insulating structural materials. In this connection, the issues of developing high-quality building materials obtained on the resource-saving technologies basis allowing to solve two interrelated problems are topical. The first problem is the industrial waste generated and existing stocks disposal. The second is associated with a decrease in the traditional raw materials deficit [1]. These problems solution, combining rational technological solutions, is based on the scientific research achievements in this area, in particular in the foam glass production. The priority scientific research areas in the foam glass materials production are the developments related to the study, the new raw materials use and the production of foam glass mixture compositions on their basis, which provide, along with the necessary performance properties, high environmental safety requirements [2, 3].

Abstract This article discusses the issue of recycling of construction wastes during major repairs (rebuilding operations). The complete analysis of design and estimate documentation of the Russian Federation developed on the basis of the effectual statutory instruments allows us to draw the conclusion that the definition of usage of construction wastes usually includes the algorithm of their treatment (storage) with a purpose of transportation to the spoil disposal in the future. The investigation results are based on the on-site inspections of buildings where major repairs (rebuilding operations) are necessary, statistics, system analysis and analytical correlation of known practical and scientific facts. A policy of recycling of construction wastes during major repairs (rebuilding operations) was created, which includes 5 main phases: information acquisition, formation of set of technological combinations for every performance phase, comparison of handling abilities of the formed performance phase combinations, calculation of resource-saving exponent, calculation of energy performance exponent, choosing of the technology edition, formation of the construction wastes recycling system. Analytical dependences were found where the amount of construction wastes developing from demolition of defective and damaged sections depends on technical condition of a building carcass. Also, estimation criterion of method are offered: resource-saving and energy efficiency. During the implementation of recycling the resource-saving exponent ranges from 55, 22% to 88, 84%. In virtue of statistics it can be said without prejudice that even today the territory of the Russian Federation accumulates about 451 million tons of potential construction wastes rising from major repairs (rebuilding operations). In case of non-act all the mentioned capacity will exert downward pressure on the environment.

In this article, the evaluation criteria (general technical condition, durability, conditional reliability) of construction objects are considered on the example of a boiler house in Rostov-on-Don. On the basis of the system analysis, a classification of characteristics is made and classification of the parameters of the construction object is made, where the main errors in the design, construction and operation are identified, and the logical and probabilistic relationships between them are identified, which made it possible to establish the possibility of the onset of critical events and states that They create emergency situations (accidents). The estimated building management criteria allow the formation of a data bank with the help of which it is planned to calculate the criteria and make decisions when operating.

The authors studied and classified some parameters of construction waste properties, construction waste energy parameters and their stability in the building technical state recovery system by means of the application of basic tenets of the theory of disperse systems. Key parameters determining the properties of a dispersion medium and dispersed phase were formed; such groups as geometric, physical and mechanical, chemical, hydrophysical, thermophysical, optical, aerodynamic (for construction waste) and space-planning, structural, technical state, climate (for the building technical state recovery system) were distinguished. Construction waste stability is considered as a resulting criterion, characterizing its behavior in the environment and making it possible to manage waste in order to decrease their stability and, eventually, providing ecological safety of construction projects.

The results of the research on the negative impact construction wastes have on the urban environment and construction ecological safety are described. The research results are based on the statistical data and indicators calculated with the use of environmental pollution assessment in the restoration system of urban buildings technical conditions. The technique for the reduction of environmental pollution from construction wastes is scientifically based on the analytic summary of scientific and practical results for ecological safety ensuring at major overhaul and current repairs (reconstruction) of the buildings and structures. It is also based on the practical application of the probability theory method, system analysis and disperse system theory. It is necessary to execute some stages implementing the developed technique to reduce environmental pollution from construction wastes. The stages include various steps starting from information collection to the system formation with optimum performance characteristics which are more resource saving and energy efficient for the accumulation of construction wastes from urban construction units. The following tasks are solved under certain studies: basic data collection about construction wastes accumulation; definition and comparison of technological combinations at each system functional stage intended for the reduction of construction wastes discharge into the environment; assessment criteria calculation of resource saving and energy efficiency; optimum working parameters of each implementation stage are created. The urban construction technique implementation shows that the resource saving criteria are from 55.22% to 88.84%; potential of construction wastes recycling is 450 million tons of construction damaged elements (parts).