Stagnation Conditions Research Articles

Does the meteorological origin of heat waves influence their impact on health? A 6-year morbidity and mortality study in Madrid (Spain)

BackgroundIn Spain, two synoptic-scale conditions influence heat wave formation. The first involves advection of warm and dry air masses carrying dust of Saharan origin (North African Dust (NAF) = 1). The second entails anticyclonic stagnation with high insolation and stability (NAF) = 0). Some studies show that the meteorological origin of these heat waves may affect their impact on morbidity and mortality. ObjectiveTo determine whether the impact of heat waves on health outcomes in Madrid (Spain) during 2013–2018 varied by synoptic-scale condition. MethodologyOutcome data consist of daily mortality and daily hospital emergency admissions (morbidity) for natural, circulatory, and respiratory causes. Predictors include daily maximum and minimum temperatures and daily mean concentrations of NO2, PM10, PM2.5, NO2, and O3. Analyses adjust for insolation, relative humidity, and wind speed. Generalized linear models were performed with Poisson link between the variables controlling for trend, seasonality, and auto-regression in the series. Relative Risks (RR) and Attributable Risks (AR) were determined. The RRs for mortality attributable to high temperatures were similar regardless of NAF status. For hospital admissions, however, the RRs for hot days with NAF = 0 are higher than for days with NAF = 1. We also found that atmospheric pollutants worsen morbidity and mortality, especially PM10 concentrations when NAF = 1 and O3 concentrations when NAF = 0. ResultsThe effect of heat waves on morbidity and mortality depends on the synoptic situation. The impact is greater under anticyclonic stagnation conditions than under Saharan dust advection. Further, the health impact of pollutants such as PM10 and O3 varies according to the synoptic situation. ConclusionsBased on these findings, we strongly recommend prevention plans to include data on the meteorological situation originating the heat wave, on a synoptic-scale, as well as comprehensive preventive measures against the compounding effect of high temperatures and pollution.

A user-friendly pitot probe data reduction routine for non-ideal gas flow applications

This contribution presents a user-friendly and robust data reduction routine for Pitot probes which can be realized using widely available software. The routine rests on the general balance equations and a database for calculating the thermodynamic properties of the involved fluids. In the present study, the proposed data reduction routine has been established as a calculation sheet using common office software and REFPROP by NIST. In the calculation sheet, the user can easily select the fluid and, manually or automatically, insert the recorded Pitot probe data and stagnation conditions. A robust algorithm directly calculates the freestream Mach number and other flow and thermodynamic quantities. The new Pitot probe data reduction routine's accuracy is assessed through several test cases, including the subsonic and supersonic flow of dry air, Novec 649, and Siloxane MM in the dilute and dense gas regime. For compressible non-ideal gas flows, it is found that the classical Rayleigh-Pitot equation is systematically in error even in the dilute gas regime where relative deviations of more than 10% are noticed. In the dense gas regime, the Rayleigh-Pitot equation fails dramatically in calculating the freestream Mach number, and errors larger than 60% can occur.

ECONOMETRIC ASSESSMENT OF THE IMPACT OF ECONOMIC INDICATORS ON THE NON-OBSERVED ECONOMY OF MOLDOVA

The non-observed economy is an integral part of the modern economic system. It is a threat to economic security in conditions of slow stagnation. The relevance of this study lies in the fact that the identification of factors influencing the non-observed economy makes it possible to develop proposals to combat this phenomenon. Also, this paper describes the problems that researchers in the Republic of Moldova face when econometrically modeling the dependence of the non-observed economy on socio-economic indicators. The novelty and purpose of the study is the construction of models with one equation, where the endogenous variable is the level of the non-observed economy in value terms and the share of the non-observed economy in Gross Domestic Product. The main research methods are regression analysis and economic and mathematical modeling. At the first step of the study, the identified main factors of influence that determine the size of the shadow economy in twenty-eight countries were systematized. In the next step, the authors established the available series of statistical data published by the National Bureau of Statistics and determined exogenous variables. The authors used the program for econometric analysis EViews 9 in constructing the models. The single equation models were tested inclusively for first and second-order autocorrelation and heteroscedasticity. The constructed models showed that the non-observed economy is positively affected by the growth of the main sectors of the national economy and by an increase in the unemployment rate. While the rise in foreign trade turnover, namely imports, negatively affects the endogenous variable. There is an identical (negative) relationship between the freight turnover and the level of the non-observed economy.

Performance analysis of heat exchanger- evacuated tube assisted drying system (HE-ETADS) under unload condition

A prototype heat exchanger-evacuated tube assisted drying system (HE-ETADS) has been fabricated and tested under unload conditions in active mode at different water flow rates (10, 20, and 30Ltr/hr). Experimental work was conducted in three different categories. Category-I: drying system in stagnation condition, Category-II: all fans are in operating condition and Category-III: ventilation window is open. Coefficient of performance, heat consumption factor, convective heat transfer coefficient (CHTC) and diffusion coefficient have been calculated in thermal performance analysis of advanced system. Highest coefficient of diffusivity (0.19) was on third day of experimentation under Category-III at 30Ltr/hr water flow rate. Maximum heat consumption factor (0.60) was calculated during the second day for Category-I at 20Ltr/hr and for Category-II it was 0.775 during third day of experimentation at 30Ltr/hr, whereas in Category-III it was 0.782 at 10Ltr/hr water flow rate during first day of experiment. Higher coefficient of performance was 0.902 on third day of experiment for Category-I at 30Ltr/hr water flow rate whereas 0.940 was on first day of experimentation for Category-II at 10Ltr/hr flow rate. Category-III achieved 0.97 at 10Ltr/hr water flow rate during first day of experiment. CHTC of north wall insulated greenhouse dryer (NWIGHD) for ground to drying cabin air was 46.622 W/m2℃, while for advanced HE-ETADS it was found 47.542 W/m2℃, which is 1.98% greater than NWIGHD. Hence, HE-ETADS has potential to enhance drying rate and reduce payback period.

Hysteresis in flame stabilization in a hydrogen fueled supersonic combustor

Hysteresis in flame stabilization mode transitions in a hydrogen-fueled strut-stabilized supersonic combustion test rig was experimentally observed and studied. Air was vitiated using H2–O2 combustion products to stagnation conditions of 8.65 bar and 1350 K and was expanded through a rectangular nozzle to Mach number 2.5. H2 fuel was injected transversely using a strut positioned at the center of the combustor. The equivalence ratio (ER) was changed in time to study its effects on flame stabilization modes. Shadowgraph and wall pressure measurements were used to study the shock system generated by the strut in the supersonic combustor. High-speed OH∗ chemiluminescence and high-speed flame imaging were used to study the heat release zones and flame structure of different combustion modes and transitions between them. Three different combustion modes were observed, namely: divergent section flame (CM1), strut wake stabilized flame (CM2), and jet stabilized flame (CM3). CM1 was observed at a very low ER, where the H2 was ignited by the normal shock positioned in the divergent section. At this point, the weak shock system at the strut is unable to ignite the fuel. At higher ER, CM2 was observed, as a stronger shock system ignites the richer mixture at the wake of the strut. It was observed that the mixture auto-ignites in the strut wake and doesn't flashback from the divergent section. When the ER is further increased, the stronger injection shock reduces the local velocity and increases the static temperature, enhancing the flame speed of the richer mixture. Thus, the flame flashes back to the fuel jet. Two hysteresis were observed in the supersonic combustor based on ER as a time-varying input. The flame stabilization mode has two solutions based on the history of the change in ER, hence indicating hysteresis. The hysteresis between CM1 and CM2 is because of the retention of the temperature and radicals in the recirculation zone at the wake of the strut. The hysteresis between CM3 and CM2 is because of the retention of the temperature and radicals in the horseshoe vortices around the fuel jets. Understanding hysteresis will help design scramjets with wider operability.

Thermochromic LaCoO3 selective layer for self-regulated thermal solar collectors

Thermochromic rare-earth perovskite LaCoO3 is a promising functional material for the new generation of selective layers and for passive regulation in thermal solar collectors. Indeed, under stagnation conditions, the solar collector overheat and this inconvenience can be skirt using a selective layer with tunable emissivity. Materials capable of reversibly switching their infrared emissivity (ε) at a certain temperature efficiently avoid overheating in such systems. For LaCoO3, a distinguishable thermochromic effect is noticed starting at 77 °C. However, due to structural and chemical complexity, its design is challenging and requires a deep understanding of crystallization mechanisms. In this work, we investigate the influence of the co-deposition process of La and Co metallic targets on perovskite crystallization and optical properties of the material. All films were deposited on aluminum substrates by magnetron sputtering in the elemental or the compound mode (Ar or Ar/O2 atmosphere) using a semi-industrial reactor with back-and-forth scrolling of the substrate. The samples were post annealed in air for 2, 5, and 10 min at temperatures ranging between 500 and 600 °C and characterized using XRD, SIMS, TEM, and infrared camera. The measurements of infrared emissivity variation show an increase of the emissivity when the temperature raises confirming the great prospects of LaCoO3 usage for the considered application. A prototype of a solar collector equipped with LaCoO3 deposited in the elemental mode was built in order to demonstrate the potentiality of this perovskite as a thermoregulated selective layer.

Country Studies of Central and Eastern Europe: How to Get Out of the Dive?

The current stage of development of studies of Central and Eastern Europe is characterized by a number of specific and common problems for the whole scientific direction. Systemic transformation in the states of the region at the turn of the 1980s-1990s led to a decrease in the level of their foreign economic and foreign policy relations with Russia, which influenced the interest in the study and accumulation of knowledge about Central and Eastern Europe in our country. In particular, the demand of state bodies for regular country studies of the region decreased, which affected the publication activity of scientific centers and the training of new scientists by specialized university departments. Central-Eastern Europe ceased to be considered as a separate region as its thirteen states were involved in European integration processes, and the number of scientific institutions and research teams for its study decreased. The disunity of specialists dealing with Eastern European problems and the low level of their scientific interaction leads to the formation of an "archipelago" of research centers. On the basis of open data, we found nine, oft en small, scientific teams for the study of history (from the middle of the 20th century), economy, society, domestic and foreign policy of the countries of Central and Eastern Europe and analyze the results of their activities in 2010-21 (including topics and territorial scope of works). It is worth to note that in the Russian regions, the corresponding research within the framework of research teams is not carried out, they have survived only in Moscow. Such a key characteristic of country studies as complexity is gone – in the conditions of methodological stagnation and in the absence of the possibility of conducting comprehensive country studies, scientists tackle its components separately, and some of them have been abandoned. The predominance of the reductionist approach over the holistic one also applies to geographical coverage: our analysis of the specialization of scientists shows that many countries in the region remain outside the research field, and interest in two or three of them is due to cultural and historical ties and foreign policy agenda. The training of researchers and teachers at the departments of universities is carried out in an insufficient level for personnel renewal, the age of twothirds of the specialists is over 40 years old. In order to assess the prospects for solving this problem, we analyzed the topics of dissertations defended over ten years in 24 Russian universities and academic institutes in history, politics, economics and economic geography of the countries of Central and Eastern Europe.

Environmental conditions during the deposition of the diatomite –organic-rich marl alternation of the lower Messinian of the Lower Chelif Basin (Algeria) interpreted from microfossil assemblages and geochemistry

The lower Messinian diatomites and organic-rich deposits of the Lower Chelif Basin (North Algeria) constitute a record of the early stages of Mediterranean restrictions, i.e. when connections with the Atlantic were limited. Geochemical proxies and microfossil assemblages from the Ouilis section allowed us to discern three members and to confirm oxygen-depleted conditions for bottom waters during alternative deposition of diatomites and organic-rich marls. The high TOC and content of redox sensitive elements as well as the absence of benthic foraminifera during the deposition of members 1 and 2 point to oxygen-depleted conditions at the bottom. Water stagnation and anoxic conditions were more intense during deposition of Member 2, when enrichments of Mo and U were the highest. U/Th and authigenic U confirm anoxic conditions in this stratigraphic interval. These environmental conditions also affected oxygenation in the water column —the composition of radiolarian assemblage is altered in conjunction with an increased relative abundance of Nassellaria, especially Stychocorys. An increase in geochemical productivity proxies (Ba/Al and TOC) and Stychocorys is related to high productivity in the upper parts of the photic zone. Moreover, high diatom content in members 1 and 2 is congruent with eutrophic conditions in the Lower Chelif Basin.A noteworthy change occurred during the deposition of Member 3, indicated by higher CO3Ca content and a decrease in TOC and redox sensitive elements, probably related to the end of seawater stagnation and re-oxygenation of the sea bottom. The record of infaunal benthic foraminifera confirms oxygen availability at the sea bottom and in the sediment pore water. Infaunal benthic foraminifera such as Bulimina, Bolivina and Uvigerina, adapted to oxygen-depleted pore waters and mesotrophic to eutrophic conditions, prevail over typical epifaunal taxa such as Anomalinoides, Cibicidoides, Hanzawaia and Heterolepa, which prefer oxic and oligotrophic environments. Therefore, the colonizers of the sea bottom after anoxic conditions were benthic foraminifera that tolerated oxygen-depleted conditions and high nutrient content. The end of seawater stagnation and the re-oxygenation of the sea bottom could be attributed to a current that mixed deep and shallow waters, favouring upwelling processes, which is congruent with the dominance of buliminids.In the upper part of Member 3, planktic forms are represented exclusively by foraminifera, while the radiolarians disappear. Planktic foraminifera are dominated by intermediate dwellers such as Orbulina, Neogloboquadrina and Globigerina, whereas deep-dweller forms such as Globorotalia are secondary. This assemblage confirms a re-oxygenation of the water column in Member 3, being congruent with upwelling processes.

Sizes of pure and doped helium droplets from single shot x-ray imaging.

Advancements in x-ray free-electron lasers on producing ultrashort, ultrabright, and coherent x-ray pulses enable single-shot imaging of fragile nanostructures, such as superfluid helium droplets. This imaging technique gives unique access to the sizes and shapes of individual droplets. In the past, such droplet characteristics have only been indirectly inferred by ensemble averaging techniques. Here, we report on the size distributions of both pure and doped droplets collected from single-shot x-ray imaging and produced from the free-jet expansion of helium through a 5μm diameter nozzle at 20 bars and nozzle temperatures ranging from 4.2 to 9K. This work extends the measurement of large helium nanodroplets containing 109-1011 atoms, which are shown to follow an exponential size distribution. Additionally, we demonstrate that the size distributions of the doped droplets follow those of the pure droplets at the same stagnation condition but with smaller average sizes.

Air stagnation in China: Spatiotemporal variability and differing impact on PM2.5 and O3 during 2013–2018

In recent years, winter PM2.5 and summer O3 pollution which often occurred with air stagnation condition has become a major concern in China. Thus, it is imperative to understand the air stagnation distribution in China and elucidate its impact on air pollution. In this study, three air stagnation indices were calculated according to atmospheric thermal and dynamics parameters using ERA5 data. Two improved indices were more suitable in China, and they displayed similar characteristics: most of the air stagnant days were found in winter, and seasonal distributions showed substantial regional heterogeneity. During stagnation events, flat west or northwest winds at 500 hPa and high pressure at surface dominated, with high relative humidity (RH) and temperature (T), weak winds in most regions. The pollutants concentrations on stagnant days were higher than those on non-stagnant days in most studied areas, with the largest difference of the 90th percentiles of maximum daily 8-h average (MDA8) O3 up to 62.2 μg m−3 in Pearl River Delta (PRD) and PM2.5 up to 95.8 μg m−3 in North China Plain (NCP). During the evolution of stagnation events, the MDA8 O3 concentrations showed a significant increase (6.0 μg m−3 day−1) in PRD and a slight rise in other regions; the PM2.5 concentrations and the frequency of extreme PM2.5 days increased, especially in NCP. Furthermore, O3 was simultaneously controlled by temperature and stagnation except for Xinjiang (XJ), with the average growth rate of 19.5 μg m−3 every 3 °C at 19 °C–31 °C. PM2.5 was dominated by RH and stagnation in northern China while mainly controlled by stagnation in southern China. Notably, the extremes of summer O3 (winter PM2.5) pollution was most associated with air stagnation and T at 25 °C–31 °C (air stagnation and RH >50%). The results are expected to provide important reference information for air pollution control in China.

Economic activity of youth in conditions of national challenges: economic stagnation, pandemic, martial law

Introduction. Employment for a person is a key issue of life. For young people, it acquires a much more important aspect, because it is young people who form new features of the future labor market. In the process of employment in the labor market, young workers can become a new drop of ideas, changes, they demonstrate their mobility quite easily, at the same time, they often cause concern among employers due to lack of experience or its complete absence or lack of patience, which reduces their competitiveness in front of more experienced competitors. Theoretical and applied problems related to changing the model of youth employment for the sake of economic growth and development in Ukraine need scientific attention. Goal. Determination of youth employment trends, their value orientations and prioritization of modern skills and abilities in the conditions of stagnation of the national economy, pandemic and martial law in Ukraine. Method. The theoretical-methodological toolkit and surveying methods are applied – interviewing young people about their employment experience; statistical – processing and analysis of questionnaire data, as well as employment center materials; graphic and tabular – strengthening the visual presentation of the material and data obtained in the research process; generalization and abstract-logical when formulating conclusions and recommendations. Results. The article examines the problematic issues of the youth labor market, which require priority solutions in the context of modern challenges. A comparison was made in the temporal dimension and the most important personal values, life priorities and goals of young people were singled out, which, together with the priority of modern skills and abilities, are the most in demand on the labor market in the conditions of a pandemic and martial law. The trends of young people's demand for the choice of a profession, which they consider promising and highly paid and which they would like to master in order to achieve success and material well-being, are considered. The importance of the reasons that can prevent youth from getting a job in Ukraine in the received profession in today's conditions has been analyzed and determined. The main sources of job search, which are the most effective for young people, have been established, including Internet resources and personal contacts. The key tasks that need to be solved in the labor market of Ukraine in the medium term in order to form a national model of youth policy are outlined.

Thermal analysis of modified conical cavity receiver for a paraboloidal dish collector system

ABSTRACT In a solar paraboloidal dish collector system, the receiver is critical for transforming converged solar flux to heat energy. A cavity receiver is the most common type of receiver, as it lowers heat loss. An experimental investigation is carried out in this article to evaluate the thermal performance of a novel cavity receiver for dish system under real direct solar environments. The performance of the modified conical cavity receiver under stagnation condition and with heat transfer fluid was studied experimentally. A solar parabolic dish concentrator of 1.83 m rim diameter and rim angle of 66° was used for the experimentation. For both cases, the experiments were carried out for two days. The highest stagnation temperature of 167.2°C was recorded with a direct irradiance of 803 W/m2, according to the data. For day average direct irradiance of 555 W/m2 and 663 W/m2, the receiver’s average thermal efficiency was found to be 53% and 69%, respectively. For 694 W/m2 direct irradiance, a maximum thermal efficiency of 75% was achieved. The thermal efficiency was shown to be significantly dependent on direct irradiation. According to the results of the experiments, the proposed modified conical cavity receiver is a viable solution for solar parabolic dish collector systems.

Intercomparison of Indoor and Outdoor Pollen Concentrations in Rural and Suburban Research Workplaces

Pollen exposure in occupational settings involves different categories of workers. In this paper the effects of diurnal pollen variations have been evaluated in two sites characterized by different vegetation and urbanization: the suburban site of Tor Vergata (TV) and the rural site of Monte Porzio Catone (MPC). Aerobiological and meteorological monitoring was performed in the two sites during the winter of 2017. The data analysis focuses on the comparison between pollen concentrations observed in relation to meteorological variables. In general, it can be stated that the indoor and outdoor dynamics for MPC and TV are different, with the outdoor concentration of pollen for MPC always higher than for TV, in accordance with significant presence of vegetation. The high nocturnal peaks detected in MPC and completely absent in TV could be caused by the presence of particular conditions of stagnation combined with greater emissions from the pollen sources. Furthermore the higher I/O ratio observed during the working hours in TV compared to MPC could be ascribed to the workers’ behavior. Exposure to pollen can be responsible for several health effects and the knowledge of its level can be useful to improve the evaluation and management of this biological risk.

Impacts of synoptic circulations on summertime ozone pollution in Guanzhong Basin, northwestern China

The Guanzhong Basin (GZB) has long been considered the most polluted city cluster in northwestern China with exposure to unhealthy levels of ozone (O3) in summer, which is strongly associated with adverse meteorological conditions and massive percussor emissions. In this study, four typical synoptic circulation types (CTs) were identified in the summers of 2014–2019 via the T-mode PCA classification method, including two polluted (southeast high and northeast ridge), one lightly polluted (east high), and one clean (northwest high) type. The impact of CTs on the atmospheric transport and diffusion conditions gradually weakened with decreasing altitude, while local circulation played a critical role near the ground, resulting in dominant northeast and southwest surface winds, high proportions of stagnation conditions (>50%). In particular, the meteorological conditions under the southeast high-type were marked by increasing influences of southerly airflow, high temperatures, low humidities, and the worst diffusion conditions, all of which were favorable for the local production of O3. While, the northeast ridge-type was characterized by easterly airflows in the upper air, which transported O3 and its precursors from upwind polluted areas. The regional transport model CAMx was applied to quantify the O3 sources over the GZB. The heaviest O3 pollution occurred under the southeast high-type, associated with the fast chemical formation rates and significant contributions from local emissions. The enhanced atmospheric oxidative capacity under the southeast high-type was suggested by elevated O3 and Ox (O3 + NO2) concentrations in the atmospheric boundary layer. Although the northeast ridge- and east high-type circulations led to similar chemical productions of O3, the cross-regional transport of O3 was increased under the northeast ridge-type and resulted in severe O3 pollution. This would serve to maximize regional O3 reduction under varying synoptic circulation conditions.

Stagnation of the Pensilungpa glacier, western Himalaya, India: causes and implications

AbstractThis study investigates stagnation conditions of the Pensilungpa glacier, western Himalaya. Multiple glacier parameters (length, area, debris extent and thickness, snowline altitude (SLA), velocity, downwasting and ice cliffs) were studied using field measurements (2016–18), high-resolution imagery from GoogleEarth (2013–17) and spaceborne Landsat, ASTER and SRTM data (1993–2017) to comprehend the glacier's current state. Results show a moderate decrease in length (6.62 ± 2.11 m a−1) and area (0.11 ± 0.03% a−1), a marked increase in SLA (~6 m a−1) and debris cover (2.86 ± 0.29% a−1) and a slowdown of ~50% during 1993–2016. Notable thinning of −0.88 ± 0.04 m a−1 was observed between 2000 and 2017 showing a similar trend as field measurements during 2016–17 (−0.88 m) and 2017–18 (−1.54 m). Further, results reveal a stagnation of the lower ablation zone (LAZ). Less mass supply and heterogeneous debris growth (6.67 ± 0.41% a−1) over the previous decade resulted in slowdown, margin insulation and slope-inversion, leading to stagnation. Stagnation of LAZ caused bulging in the dynamic upper ablation zone and favored the development of supraglacial ponds and ice cliffs. Ice cliffs have grown significantly (48% in number; 41% in area during 2013–17) and their back-wasting now dominates the ablation process.

CHANGES IN THE ADMINISTRATIVE AND TERRITORIAL STRUCTURE OF UKRAINE IN THE CONTEXT OF INFLUENCE ON THE STATUS AND FUNCTIONS OF SETTLEMENTS

The purpose of the administrative and territorial reform in Ukraine is, first of all, to give broad powers to communities for their development, as well as to balance the quantitative parameters of administrative and territorial units of different sections. In the process of implementing the reform, the status and functions of most settlements are also changing, which will affect their social and economic development and change inter-settlement ties.
 The article analyzes the quantitative parameters of the modern administrative and territorial system in Ukraine. It is noted that it was not possible to eliminate significant disparities in the size and population of the newly created districts and territorial communities. It is also noted that the agglomeration will take place around district centers, other urban settlements, less often - around large villages. It is emphasized that only the villages that will become community centers have prospects for further preservation of their functional significance in the settlement system.
 In general, 47 cities and almost 440 settlements will not become community centers. There are also cases of classifying urban settlements as rural territorial communities. 354 urban settlements, which had the status of district centers before the reform, now have the status of centers of territorial communities. As a result, the powers of such cities extend to a much smaller number of settlements, and their functional significance will decrease. Service functions and a role in the resettlement system will also be lost to settlements that do not become community centers but are attached to urban ones.
 The article substantiates that the reform of the district level of administrative structure involves a change in the direction and intensity of inter-settlement ties. In conditions of prolonged social and economic stagnation, demographic crisis and unsatisfactory transport connections, this may lead to a deepening of polarization in the settlement system and an increase in peripheral areas. Some medium-sized cities that had the status of cities of regional significance (among them – Novovolyns’k, Horishni Plavni, Enerhodar, Smila, Irpin’) will not be district centers, because the limiting factors for granting them the status of district center are the asymmetric position or mono-function structure of the economy. For most small towns that have lost the authority of the district center, there is the alarming possibility of losing the status of the city. At the same time, in sparsely populated Polissya, steppe or mountainous areas, such small urban settlements will become the centers of enlarged districts, so their functional significance will increase. The condition for the effective performance of the cities-centers of their functions is the development of industrial and social infrastructure, transport connections with remote settlements.
 According to the results of the study, positive and negative aspects of the impact of the administrative and territorial reform and changes in the status and functional significance of settlements have been identified. Further research on this issue will include a detailed analysis of the functioning of territorial communities and new districts in the context of the impact on the settlement development.
 Key words: decentralization, territorial community, resettlement, administrative and territorial reform, functions of settlements.

How to restore the safety of the people of Russia

For every nation, preservation of the people is the most important thing. For Russia this life-affirming task is as important as for no other power due to its specific features. We are talking about the key geopolitical task of our country, since Russia has 17% of the Earth's land. At the same time, Russia's share in the world economy at purchasing power parity is 3.1%, and the population of Russia today makes only 1.9% of the world's population. And a further reduction in the country's share of the world population is highly undesirable. To stop the decline in the population by 2025, and then begin a gradual recovery of its size, three main measures are needed. The first and most significant is reduction in mortality, which in Russia on average with the account of the age structure, is 30-40% higher than in developed countries and 20% higher than in post-socialist countries. The main thing here is to reduce mortality in working age, from cardiovascular diseases and external causes. The second most important thing is to ensure migration growth to Russia up to 250 thousand people per year. The third is to increase the total fertility rate from 1.5 in 2019 to 1.75-1.8 by 2030. It is impossible to improve the demographic indicators and restore the safety of the people in the conditions of crisis and stagnation. But it is impossible to move to socio-economic growth without raising income and consumption of the population. The main condition for preservation of the people is resumption of the socio-economic growth by 3-4% per year that will ensure growth in the real income of the population and final consumption of households, assistance to families with children in order to overcome poverty and, ultimately, an increase in the birth rate.

Modeling and Analysis of Shock Reduction through Counterflow Plasma Jets

The study presents a numerical investigation of aerodynamic drag reduction by implementing a counterflow plasma jet, emanating from the stagnation point of an aerodynamic surface in a supersonic regime with a constant pressure ratio PR = 3 , and compares findings with a conventional opposing jet. The computational study is carried out by solving three-dimensional and axisymmetric Navier–Stokes equations for counterflow plasma-jet interaction. The calculations are performed at free-stream Mach ( M ∞ = 1.4) with sea level stagnation conditions. The weakly ionized argon plasma jet generated by a plasma torch has constant stagnation pressure and temperature of 303,975 Pa and 3000 K . The effect of the Mach number and the angle of attack variation on plasma-jet effectiveness is also analyzed. The results indicate that the counterflow plasma jet reduces more drag (in twice) compared to the conventional jet (nonplasma). The gravitational, magnetic field effect and chemical processes in the plasma formation are considered negligible. It is inferred that the effectiveness of the counterflow plasma jet strongly depends upon the jet stagnation temperature.

NATURAL WIND DRIVEN SUSTAINABLE VENTILATION SYSTEM (PROTOTYPE) FOR INDOOR LIVING SPACES

One of the main design tasks of indoor space is to achieve human comfort. Cross ventilation systems are numerous but to propose a natural system that could be easily applied in different weather conditions is challenging. This study focuses on how to apply cross-ventilation by the direct and indirect driven wind. The research aims is to enhance design decisions by utilising venturi or stagnation conditions. This can be achieved by different openings and wall distributions that can help control wind velocities naturally in indoor spaces hence providing human comfort and at the same time save energy. By utilizing a simulation tool (ANSYS), it was found that in a moderately hot climate zone slightly windy, by a simple venturi proposed air velocity intervention air velocity can increase up to 42% of average outdoor air velocity between 2m/s and 8 m/s and by utilizing stagnation condition air velocity can reduce up to 55% of average outdoor air velocity between 2m/s to 8 m/s. The main aim of this research is to propose a design prototype for different types of indoor space such as hotel room prototypes to achieve natural comfortable ventilated living spaces.

Scenario Analysis of the Risk of Gas Pipeline Failures in the North

Low temperatures and abnormal meteoconditions of the North have significant effect both on the accident frequency, and on accident development. Abnormal weather conditions of the North are characterized by the powerful temperature inversions arising at an anti-cyclone due to the emission of permafrost soil at extremely low temperatures of air and conditions of air stagnation. These abnormal conditions influence process of gas dispersion in the atmosphere, promoting its deceleration and formation of explosive concentration of gas at the Earth’s surface. Based on the results of gas pipeline failures analysis occurred in the North, the main causes of gas pipeline accidents were identified, the gas leakage “fault tree” from the gas pipeline was developed with estimation of failures frequencies, and the frequency of emergency situations in case of gas leakage from the gas pipeline was estimated. The most dangerous scenarios of gas pipeline accident evolution have been identified and their risk levels in the zone of the damage factors have been assessed on the basis of acceptable risk criteria. It is justified to increase the action range of damage factors in an explosion of methane -air mixture cloud in open space at presence of temperature inversion.