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A directional coupler is a passive device designed to divide the power between its outputs in a given ratio. The value of this ratio depends on the resistances of the segments with which the device is assembled. It is important to understand how the miniaturization efficiency of a 3 dB directional coupler varies at different operating frequencies. Modeling and calculation of the characteristics of the devices was carried out in a specialized program Cadence AWR. The first step in the work was the design of taps ac...

Most methods of mining waste water treatment require significant costs for the construction and operation of tailings. Their area is calculated from the sedimentation time of impurities and suspended particles. The paper shows that an effective way of mining waste water treatment is flocculation of impurities and suspended particles and the subsequent flotation of the resulting flocs. Based on the results obtained, the Mining Institute KSC RAS has developed a technology for mining waste water treatment, including ...

The universities in Bulgaria operate in a very dynamic environment. The Ministry of Education and Science (MES) changes annually the requirements that their systems must meet. Changes can be small and affect only parts of the information systems in use or impose fundamental changes. To cope with this challenge, each university has a choice - either to move to a high level of digitalization or to maintain a minimum digitization of processes, so that no correction is needed in them, thus increasing the hours of work...

The increase in the price for non-renewable energy resources has led to the finding of cheap alternative fuel solutions that can meet the growing demand for energy. The objective for the researchers is to use renewable energy as an alternative energy source to produce green energy. Over time, researchers have developed several types of shapes for the wind turbine: small, which have a generation capacity of 50-60 KW of power; On average, they have a capacity between 50-1500 KW and large, capable with a capacity of ...

?Ensure sustainable consumption and production patterns? is one of 17 goals of The 2030 Agenda for Sustainable Development, adopted by all United Nations Member States in 2015. The target is by 2030, substantially reduce waste generation through prevention, reduction, recycling and reuse and the key indicator is the Recycling rate measured by tons of material recycled. The aim of the research was studying of the regional aspect of municipal waste management disparities in Bulgaria. The progress for achievement of ...

In this paper, we propose a mathematical model and an appropriate algorithm that allows one-time measurement of the frequency response and phase response of the MET sensor under normal conditions to construct a complex transfer function of the MET at any other temperatures from the allowable range of -35 + 55 °C with the experimental accuracy not worse than a few percent. This model and the algorithm for setting up and selecting thermocompression circuits of electronic amplification and filtration circuits introdu...

The main cause of air pollution from vehicles is related to the harmful emissions from engines, manly associated to the petrol industry and internal combustion engine manufacturers. As mention into the technical literature, the pollution emitted directly from engines is not the only cause of concern. Besides the liquids obtained from petrol (fuel and oils) and the ones used for air conditioning, the particles thrown off from brake pads is the third cause of air pollution from components of vehicles. It has been re...

Samples of biodegradable composite material obtained by mixing a biodegradable polymer (PLA) as a matrix and chopped fine wood as a filler were developed. The filler in the samples was preliminary thermally modified at various temperatures. Composites were studied for biodegradation in alkaline solutions of NaOH and KOH. It was found that the biodegradability of pure PLA was significantly lower than that of composites based on PLA and a wood filler. In addition, the experiments revealed that by adjusting the degre...

For the Arctic region of Russia, an inventory of the biodiversity of aquatic ecosystems for the purpose of environmental monitoring is extremely urgent. Global warming for terrestrial ecosystems manifest as changes in the distribution of individual species and assemblages, in the timing of important life-cycle events, and in abundance and community structure. Zooplankton communities in the Northern lakes are highly diverse and thus perform a variety of ecosystem functions. The most important role of zooplankton is...

An interest to bacteriocins as natural alternative for antibiotics and chemical preservatives is grow at present. The selection of novel strains producing antimicrobial peptides is in focus. The probiotics are preferable because they are recognized as safe and thereby can be applied in medications, foods, feeds. Moreover, the benefits of probiotics for human and animal health is proved. The growth kinetics of industrial probiotic strains Lactobacillus plantarum B-11007, Lactobacillus salivarius B-2214 ? Lactobacil...

Honey is the unique product which forms in fermentation of flower nectar by bees. It has been known for its healing properties for many centuries. The prevail component of the honey is monosaccharides (first of all glucose and fructose). Nevertheless, di-, tri- and oligosaccharides as well as proteins and pigmenting phenolic compounds can be detected. The specific saccharides of honey are in interest as prebiotics. The phenolic compounds can suppress different microbes including pathogens and food contaminants. Th...

The solution of environmental monitoring problems is often limited to the use of proprietary software, which can adversely affect costs, flexibility, and data integration. The need for environmental monitoring system is especially acute in the field of public environmental monitoring, where teams of potential users unite researchers from different areas of science from biology and chemistry to sociology and economics. Simulation technology of environmental monitoring involves three main areas of activity: observat...

Mining activity entails accumulation of sulfide?bearing mill wastes with high concentrations of ore elements (Fe, Cu, Zn, Cd) and impurities (As, Hg, Be, and Tl). The volumes of hazardous sulfide-containing mining waste in non-equipped storage facilities according to modern standards reach several billion tons in Russian Federation. The handling of abandoned waste in our country is not currently regulated, the question remains open: there is no established methodology for estimating stockpiles and handling of wast...

Operational monitoring of orchards is the basis for decision-making in management and correction of agricultural practices during fruits production. Especially important is the monitoring of phenological development of trees, which predefines agrotechnological operations, and fertilizers application dozes, and dates. The monitoring results as well can be used for forecasting fruit yield and planning fruit production and fertilizer needs. At present, operational monitoring of large orchards is practically not condu...

Floods are exceptional processes, observed in daily life as part of the hydrological cycle or as unusual extreme events. As a result of significant precipitation, snowmelt or/and anthropogenic pressures and technogenic disasters river flow rapidly increase causing an overflow on rivers floodplain with possible damages on the crop, households, economy, infrastructure, social life, etc. Observed consequences depend on the local conditions. They can be negative or insignificant in case of comparatively minor floods, ...

The article presents a detailed study of the close relationship between the content of total dissolved iron (Fetotal), Fe2+, Fe3+ on the one hand and physical and chemical parameters (Eh, pH, salinity (S), water temperature, electrical conductivity (Cond), the content of molecular oxygen and its saturation percentage in the section "Don River - Sea of Azov" on the other under various weather conditions. Correlation coefficients, as a quantitative measure of the tightness of the connection, varied over a wide range...

Substances of petroleum origin that reach groundwater limit water use and can have irreversible effects on ecosystems interacting with them. Quantitative changes in groundwater and synergistic effects generated by petroleum products on ecosystems can be objectively quantified based on a scenario for the transport of pollutants concentrations through the aquifer. In this sense, with the help of mathematical models, the research estimates the spatial and temporal dimension of a possible accidental pollution by petro...

Mobile mapping systems (MMS) are becoming used in standard geodetic tasks more common in the last years. This paper deals with independent accuracy evaluation of MMS RIEGL VMX-450, and recommendation for which types of tasks is effective to use tested MMS. Data from mobile laser scanning and mobile photogrammetry obtained by tested system were evaluated. The new test point field was built in area of Advanced Materials, Structures and Technologies (AdMaS) research centre that is part of Brno University of Technolog...

The results of instrumental observations of the acoustic effects caused by stronger earthquake with the magnitude mb = 5.7 which occurred in Iran on July 08, 2019 are given. The observations were carried out at three pointes: Geophysical observatory "Mikhnevo" (54.94° N; 37.73° E), Center for geophysical monitoring in Moscow (55.70° N; 37.57° E) of Sadovsky Institute of Geosphere Dynamics of Russian Academy of Sciences and at a point located in Zvenigorod town, Moscow Region (55.69° N; 36.77° E), which provided th...

In our scientific approach we have sought for showing who are the main actors of the financial markets, i.e., those persons who decide, directly or indirectly, on all the events which may occur on the said markets but, above all, on those who require a sustainable financing of long term impact on mankind. Such persons hold positions on various levels of the financial entities but all of them have a decisive role in the making of most of the decisions which have as a result various actions on those markets, either ...

The Volinian Adancata sandstone (Lower Sarmatian) is exploited from the northwestern part of the Moldovian Platform, which represents the continuation of the great East-European Platform and which lies in front of the Eastern Carpathians (in Eastern Romania). Adancata sandstone is a slightly micaceous carbonate sandstone that has been exploited since the Middle Ages to the present, with some temporal syncopes after the Second World War. The current exploitation of the sandstone levels is made in two quarries locat...

Summary. Aluminum, entering the human body, has the property of accumulation, modulates immunoregulation and metabolism, especially mineral. It also exhibits the properties of a sensitizer and neurotoxicant, mutagen and carcinogen. And in the case of aerogenic exposure, the target object is additionally the upper and lower respiratory tract system. Exposed by aluminium children are especially inclined to occurrence of negative effects. The research is aimed to study the immune status of children of primary school ...

Air pollution is one of the main environmental causes for the occurrence of many diseases in the Republic of Bulgaria. Despite the efforts and measures taken by the responsible institutions, polluted air continues to have adverse effects. Bulgaria is still far from achieving levels of air quality that do not pose a risk to humans and the environment. In this context, the purpose of this publication is to evaluate the air quality of the border municipalities between the Republic of Bulgaria and the Republic of Serb...

This paper describes an algorithm that proposes compositions of structures that are in contact with the cooled environment based on the user's priorities. Specifically, the algorithm evaluates the construction of floors, flat, and pitched roofs. The algorithm compiles these structures based on individual technical criteria and their set priorities in combination with the price of materials. Multi-criteria methods such as the Saaty method and the weighted sum method are using to determine the importance of individu...

The problem of quenching small vibrations of a mechanical system near its equilibrium position is considered. A method for finding switching points of piecewise constant control for simultaneous damping of several vibrations of the same frequency is proposed. As an optimized functional "the Expenditure" is considered. The method leads to explicit formulas. All results of research are formulated as the theorem. As an example the problem of stabilizing the spacecraft's rotation axis is considered. The mathematical m...

The constant need for techniques that contribute to the environmental preservation has led researchers worldwide to intensify their studies regarding different routes that enable the environmental protection. Azo - dyes can be found in aquatic matrices and conventional procedures applied in effluent treatment plants showed not so good results in respect to degrading this type of dyes that are usually persistent and refractory. Also, textile dyes release important amounts of toxic and resistant color effluents that...

This study performed a hygienic analysis of pollutant emissions from stationary and mobile sources and hygienic assessment of air quality for 2007-2019 according to official statistics of the Russian Federation. It was found that the main sources of emissions are motor vehicles, ferrous and nonferrous metallurgy, fuel and energy complex, machine building, timber, woodworking, coal, mining, pulp and paper, chemical and oil refining industries. As results of hygienic analysis showed, the total amount of pollutant em...

Aboard a ship, the noise is a sum of several factors: equipment (engines, propellers, compressors), and the waves (if the Danube is very hectic), etc. The noise leads to discomfort for the crew. This paper studies the noises on 2 river vessels traveling on the Danube between Sulina and Budapest, in February and April 2019. The noises were measured with Blue Solo sonometer and analyzed with dBTRAIT Software. The determinations were made while running, in the engine room and in the control room. To check the noise l...

In recent years, the European Commission (EC) has increased interest in environmental issues, focusing its attention on the green economy concept. Green Public Procurement (GPP) is a voluntary tool that integrates environmental criteria with all steps of the process of purchasing goods and services. With the first Public Procurement directives, the EC introduces a useful framework to define guidelines for the adoption of GPP. In Italy, the definition of the GPP National Action Plan (GPP NAP) for the environmental ...

Water ecosystems of Arctic region are most vulnerable to modern climatic changes, since global biogeochemical processes mostly occur on territories of permafrost zone. This work gives new insights into fundamental research question of how fast organic matter of thawing permafrost can be converted to greenhouse gases which are emitted into the atmosphere (for example, CH4). We aimed to identify microbial response and associated release of CH4 from Arctic lakes in response to temperature increase. We investigated la...

The efficiency of a mining enterprise depends on the quality and timeliness of management decisions. Despite the fairly high scientific, theoretical and practical levels of development of this scientific direction, the abundance of software products on the market, the issue of effective technological management remains very relevant and important. The analysis performed by the authors made it possible to establish that the weakest link in existing systems is to take into account the relationship between the parame...

A major risk factor for freshwater coastal aquifers is represented by seawater intrusion, consisting of the movement of marine saltwater into these aquifers. This occurs due to sea level changes, tidal fluctuations, changes in evaporation and recharge rates, fractures in coastal rock formations, or excessive freshwater pumping. The negative effects of this salinization phenomenon are a reduction in the available freshwater storage volume, the contamination, and the abandonment of production wells. In Romania, such...

The main purpose of this paper is to provide new geological information and interpretation of the well data from the Istria Basin, Western Black Sea. Therefore, we present a reconsideration of the microfaunas (mainly foraminifers) and calcareous nannofossils described from several wells drilled on the Lebada East structure belonging to the Istria Basin, by using core reports. Thus, we have been able to compile integrated information regarding the lithology and biostratigraphy of the wells. We have focused on the s...

Considering that the underground mining of coal is used mining systems that have a high degree of complexity, and can reach cumulative lengths of tens of kilometers, associated with them we have the ventilation networks with the role of transporting important air flows with the help of special ventilation systems. The aeration networks are made up of all the mining works on which air flows are carried. Structurally, they comprise nodes and branches. The nodes of an aeration network are generated by the intersectio...

The Dobsina dam is a part of the water management system ?Dobsina? which consists of the Palcmanska Masa reservoir, the Vlca Dolina hydroelectric power plant, and the Dobsina afterbay reservoir. Palcmanska Masa and Vlcia dolina dams were built in the years 1956 -1958, Dobsina dam in 1960. It is an earthfill dam, and the body of the dam is divided into the left and right part by a functional outlet block, which is situated in the valley alluvial plain. On the left side of the dam, the sealing was built of stabilize...

The study of erosion processes in settlements is a pressing issue since they develop rapidly sometimes. The purpose of this study is, however, to identify the dynamics of erosion activity in settlements of the Middle Ob region. The study objectives are focused on identification of hazardous areas, which is necessary for making informed decisions related to well-minded bank protection. The targets of the study were settlements of the Middle Ob region (Pasol, Vata, Vysoky Mys villages) within the latitudinal stream ...

Anthropic activities involve the extraction of the transformation and use of natural resources. During the process of extraction at the surface or underground of useful minerals, particles or gases resulting from the natural rocking or release from the rock mass appear in the working environment. The process of transforming useful mineral substances is carried out on the surface in enclosed enclosures, involving the use of complex technological processes. During the course of these technological processes, explosi...

The paper deals with the laboratory testing of the shear strength of the soil-geotextile interface. Two samples of soil were tested, i.e., coarse-grained poorly graded sand and fine poorly graded ash. The soils were reinforced using the Thrace WG80 black woven geotextile, which is suitable for road, railway, and geo-bag applications. The tests were executed using a large-size direct shear test apparatus. The shear strength of the interface was determined using the large-size direct shear test apparatus. The ground...

At present the traffic lights are common part of the road intersections. This type of traffic control has many advantages: increase in traffic safety, clearly defined driving preference, increase in intersection capacity etc. On the other hand the intersections with traffic lights can show also some disadvantages, for example wrong behaviour of road participants, problem with traffic flow continuity, often due to wrong signal program, traffic volumes or geometric and building parameters of intersection, economic a...

The exodus of young people from rural areas in Romania, corroborated with the decrease of the population at national level is a major problem of the country. The Common Agricultural Policy integrates this issue, finding several forms of support both in Pillar I, on direct payments, and in Pillar II, on rural development. This paper proposes the analysis of support for young farmers in the second pillar. Thus, the measures related to the support of young farmers through the National Rural Development Program will b...

This paper describes the tools developed for modelling mine-ventilation networks and postprocessing simulation results using the Aeroset software, with a specific focus on solution visualization tools. These tools are aimed at simplifying the analysis of simulation data of large ventilation networks ? the visual representation and graphical analysis of models of such ventilation networks, with many (more than 1000) branches, becomes difficult without the use of specific tools. The following special tools are sugge...

In the 1920 accrued one vehicle per one thousand inhabitants, in 1960 twenty cars per thousand inhabitants, and today it is 400 cars per 1000 inhabitants. The population and the numbers of vehicles increase causes a lot of economical and environmental problems, not only in Czech Republic but in the whole world. Today, parking is considered as a big problem for many reasons. The reasons are the numbers of inhabitants and numbers and size of vehicles increase, restricted parking spaces, traffic jams on roads, the lo...

Rapid development of residential housing in Kazakhstan entails an increase in the consumption of thermal energy and, accordingly, carbon dioxide emissions into the atmosphere. According to the Department of Statistics, only in 2019, 41,415 individual and 1,746 multi-apartment residential buildings became operational in the country of the total living area of 13,133.8 thousand square meters. Providing that all built houses comply with energy efficiency requirements of Kazakhstan, the introduction of new housing has...

The studied tailing dump is located on a hill in the urban village limits (Komsomolsk, Kemerovo region) and contained cyanidation wastes. There are the comprehensive school and the central street of the city below a hill, and the kindergarten on the opposite hill. Due to the easy availability of atmospheric oxidizing factors, the material of the bulk dumps changes very quickly, and, of course, seeps into the hill. Two types of streams interact with the material of the Berikul bulk dumps: infiltration water that se...

The reason for the creation of playgrounds was the effort to get playing children off the city streets where they could get injured due to increasing car traffic. More than 160 years have passed since, and the playgrounds have gradually been transformed according to the needs of the time. Denser traffic, and generally a sense of greater discomfort among strangers, have increased demands on finding ways how to satisfy all the needs of the children with their escort. With the development of transportation, the feeli...

The paper studies theoretical and experimental issues of improving scour protection facilities of oil trunk line underwater passages. External influences on the stability of oil trunk line underwater passages were analyzed. Based on the analysis results, the impact of hydraulic processes on riverbed deformations in the underwater passage of the Surgut-Polotsk oil trunk line was evaluated. Also automated calculations of hydraulic and riverbed effects of the bottom soil scour in the Mathcad application environment w...

There is observational evidence that the global sea levels are rising and increasing the risk to coastal communities from floods and erosion. Interest in marine sea level research is determine not only by forecasting cataclysms and sea level rising, but also in connection with interdisciplinary studies exploring the causes of this change. The article outlines time series analysis of tide gauge data to solve for short and long-term sea level variations at Varna and Burgas tide gauge stations. The data covered the p...

The territory of Bulgaria represents a typical example of high seismic risk area in the eastern part of the Balkan Peninsula. The spatial distribution of seismicity in Bulgaria is uneven, which gives reason to group earthquakes into geographically defined zones - seismogenic zones. In the present study the Sofia seismogenic zone will be examined. Sofia seismogenic zone is located in southwestern Bulgaria - the area with pronounces tectonic activity and proved crustal movement. The capital of Bulgaria - the city of...

Waves represent the most important factor in the evolution of the coastal zones. One of the main causes leading to the wave formation is the movement of the air masses. A particular influence on the wave agitation regime in the littoral sector is exerted by the shore configuration, water depth, bottom relief and the formation of ice cover in winter. The scope of this paper is to analyze the historical data on the wind and waves in the Danube discharge area. The emphasis is on the maximum values of wave heights and...

The aim of the paper is to propose an analysis of the current status of scenario-based disaster response training with extended reality (XR). It is considered the different scenarios designed and developed by XR tools and technologies, and also their application for innovative training to effective response upon the occurrence of various natural disasters. In recent years, with permanently established the climate change, there has been a steady increase in the frequency and intensity of natural disasters as intens...