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Taking into account the sedimentation features since the last 5 decades, considerable anthropic modifications on the Danube channel are present, as the debris composition varies concerning the proportion of terrigenous minerals, lithoclasts, bioclasts and organic matter. Since the 7th decade of the last century, marked by the construction of most hydrological power plants on the Danube, Olt, Jiu, Cerna and other major rivers, a significant change of the sedimentary volume brought downstream by the Danube is assume...

The earthquakes are among the most common natural events in Bulgaria. Earthquakes represent a societal challenge as well as globally necessitating practical and operational solution for mitigating risk and reducing losses. This is achievable though earthquake risk assessment. The assessment of seismic risk is based on procedures for integration of seismic hazard and seismic vulnerability of the bearing structures of the building stock. The building stock is divided into three main groups, taking into account the s...

In oil and gas exploration we need to consider all the geological components and how they come together to have source rock character, trap formation geometry, or reservoir quality. To understand these mechanisms we have to analyze the geological evolution dictated by tectonic uplift, landscape dynamics and drainage network evolution. Paleogeography together with reconstructions of climate and sea level changes allows us to predict source and reservoir facies, which means a great advantage for exploration. The Wes...

An earthquake catalogue covering the seismicity on the territory of Bulgaria and adjacent lands for the period 2000-2020 is presented in the current study. In this catalogue are included events with magnitude equal to or larger than Mw ? 2.5. As a country, Bulgaria belongs to the Alpo-Hymalian seismic belt, it is also not absent of strong earthquakes. Bulgaria is an earthquake prone country taking in account that on its territory are recorded some of the strongest earthquakes from the beginning of the last century...

The problem of studying the interaction of various geophysical (seismic, acoustic, meteorological) fields is considered in the context of prediction of geoecological risks generated by technogenic and natural phenomena. Early it was proved that meteo-dependent processes of infrasound propagation from explosions in the atmosphere can increase many times the ecological load on the social and natural environments. Such situations are observed in the open coalmines, test sites, and other objects where regular explosio...

The purpose of mathematical modeling of runoff flow in sewer networks is to assess the hydraulic capacity and monitor their behavior in different conditions to predict the future state. Models of sewer networks are part of the design process. Their advantage is the possibility of simulating the future state of the network and the precipitation and runoff process in the context of climate change. With the help of simulations, it is possible to anticipate future conditions in the river basin and thus effectively des...

The article assesses the size of the shadow economy of the Russian oil and gas industry. The article addresses factors in the shadow economy emergence and development in the oil and gas sector. The article justifies methods fighting the phenomenon. The article proposes a system of measures reducing the size of the shadow economy in the oil and gas sector and its impact on the economy of Russia. It has been proven that amid the crisis caused by the COVID-19 pandemic and political and economic sanction pressure of E...

Humanity vision about steadily increasing its quality of life has had as a consequence the maintained search for available odds in order to design various energy supply systems based on different energy resources. The innovative thinking way of human beings has always been also driving the field of shaping more efficient energy supply systems with less unwanted environmental impacts. Conventional energy supply systems, especially based on fossil fuels, have been since long applied, their impacts being especially p...

A severe problem affecting urban areas is a large number of stray animals, either r eject- ed by their owners or born in the wild. These animals face the problem of malnutrition, as it is difficult for them to obtain food without human help in urban conditions. The fact that shelters are overcrowded is not suitable for these animals as well well. In o rder to protect them from the tragic death of starvation, the authors decided to de- velop an intelligent system for feeding stray animals. The system makes it possi...

The forests of south-western part of Zemgale Plain in Latvia are characterized by Scots pine (Pinus sylvestris L.) stands on fertile, nutrient rich soils. The existing information about these sites suggests of the calcium carbonate rich loamy sand soils formed by moraine. The Scots pine stands in area of Tervete National Park reach age of 260 years. The oldest and biggest trees reach considerable dimensions – up to 70 cm in diameter and height of 47 m, thus exceeding the country's average indices. These are the ol...

The processes of liquefaction of water-saturated soils under dynamic impacts are one of the many negative and destructive geological processes and phenomena that constitute the geological hazard in Bulgaria. Processes of liquefaction of water-saturated sediments on the territory of Bulgaria are registered during almost all strong earthquakes affecting its territory from both local and regional sources. Specific cases have been described by a number of authors. These processes lead to loss of bearing capacity of wa...

Soil water content and understanding water dynamics is crucial for agricultural practice. Direct measurements of the soil moisture are being slowly replaced by the mathematical simulations and models. One of the most used models for the simulation of the soil moisture is the HYDRUS 1D model, which simulates how the water is transported through or within the soil profile. The soil water model HYDRUS can simulate water movement through a porous media during transient (irrigation) and steady state (between irrigation...

Unfortunately, soil is a non-renewable resource that fulfills several vital functions such as food/biomass production, storage, filtration and transformation of mineral or biological substances, source of biodiversity and habitats, etc. Due to the development of industrial activities outside the localities, in many areas the soil is degraded. Among these degradation processes can be mentioned degradation of organic matter, contamination, soli salting, and erosion. This paper is dedicated to the presentation of the...

The studies of the medieval fortified settlement Kushmanskoe-3 showed significant differences in the chemical properties and biological activity of the cultural layers of plots located on the inner and outer parts of the settlement, on both sides of the fortification line. The average values of organic carbon, total phosphorus, urease activity and the number of thermophilic bacteria were significantly higher in the cultural layers on the inner plots located to the south of the fortifications, as compared to the cu...

Decision-making theory has been developing significantly for the last 50 years. It finds its various applications in the very different fields of human activities: engineering, social and life science, and sure economics. The task of substantiating decisions under conditions of uncertainty of all types, except for a priori is reduced to narrowing the initial set of alternatives based on the information available to the decision maker. The quality of recommendations for decision-making under conditions of stochasti...

In this paper, a class of multi-extremal stochastic programming problems is considered. Direct and dual problems are also included in this problem, respectively, in this paper the question of the existence of solutions to such problems is studied, the necessary theorems and proofs are given. Decision making under uncertainty is based on the fact that the probabilities of various scenarios are unknown. Decision-making under risk conditions is based on the fact that each situation of the development of events can be...

The development of urban areas, transport, and technical infrastructure is one of the natural phenomena that have been going on for several centuries. In recent years, due to migration population in many developed countries occurs a rapid increase of impervious areas in urban agglomerations. The rapid development of an impervious surface can cause changes in the hydrological and climatical characteristics of the area. As a result of these changes, surface runoff is creating. Surface runoff is an area source of pol...

The Vrancea zone, located in Romania, at the sharp bend of the Southeastern Carpathians, is a well-defined seismic region in a continental convergence area with unique properties and generating the most destructive subcrustal earthquakes in Europe. The seismicity is concentrated in a confined, high-velocity, focal volume at 60–200 km depth range. The increasing number and quality of waveforms digitally recorded in the last time by the National Institute for Earth Physics (NIEP) provide the opportunity to better co...

The paper examines the theoretical and experimental issues of formation of protective areas (biogroups) that allow preserving trees of scientific or historical value during intermediate felling. As a result of experimental studies, mapping and estimation of reserved and felled trees are carried out on 10 sample sites, in which intermediate felling was performed and which have similar characteristics. For the analysis of the spatial structure of stands, electronic maps for plots of 1200 m2 are made in the GIS Map a...

?very year, forest fires tens of thousands occur in Russia, as which result in more than 1 forest a million hectares are burned. At the same time, and even forest larger amount is damaged, and later perishes. For example, thermal radiation from a fire front directly affects a tree cambial layer, and this leads to its death. Also, due to the heat transfer of heat to the soil, its chemical composition and structure, microflora and soil change fauna, and the trees surface roots are damaged. Damage from forest fires i...

Precision management of the crop production, implemented in the precision farming system, implies a spatially differentiated, based on spectral measurements, implementation of agrotechnical measures provided for by the technology of their cultivation. The study of the spectral characteristics of spring wheat crops under changing agricultural conditions was carried out in a multi-factor micro field experiment at the Menkovskaya experimental station of the Agrophysical Research Institute (Russia, Leningrad Region). ...

The provisions of the Geodesy and Cartography Act (in force since 2006) provide for the establishment of a Geo Information System. So far, this Geo Information System has not been created for one reason or another. Given this fact, this publication aims to comment on the main provisions and advantages of the transition to reference to standards in the legislation (primarily Ordinances and Instructions) in the field of Geodesy and Cartography in the country, i.e. reference to one or more standards in place of detai...

The determination of residual oil reserves is a complex task that involves high qualified specialists and resource-intensive calculations. Classical oil reservoir simulation methods cannot provide proper level of reliability due to increasing of complexity caused by oil reservoir depleting. Stagnant oil zones arising from heterogeneity of shear modulus of medium cannot be determinate by oil reservoir simulation due to use of effective values of porosity and absolute and phase permeability. The problem of determina...

Modeling is important for river system analysis and management. The aim of the research is to apply disaggregation models to data with recovered natural river flow of Osam River located in North Bulgaria. As a result river discharge synthetic sequences are generated on monthly and seasonal discretization. We want to test applicability of the models for specific climatic, hydrological and orographic conditions in Bulgaria. Disaggregation models are from the family of stochastic models. Disaggregation models could b...

Globally, modern crustal movements are being studied as a priority, a large number of projects are being developed and significant funds are being allocated for the development of research in this field of science. Due to the social importance of the problem, the need to obtain geodetic data on the current activity of the earth's crust is realized. This article examines the study of the temporal movements of the earth's crust and the accumulated stresses in a geologically and seismically active region with the pre...

Excess natural and technogenic chemical exposure have a negative impacts on the regulatory systems of the body. This leads to a decrease in its resistance and adaptabilities. The child`s body is the most vulnerable to the impact of adverse environmental factors owing to the age characteristics. Strontium belongs to the group of metals that can form an improper quality of drinking water, and is also included in the list of the main indicators of water quality according to the requirements of sanitary standards of t...

The efficient use and recycling of industrial water is a major challenge to the sustainability of the planet. Blast furnace slag is a by-product of metallurgical operations during the production of cast iron. The granulated slag is obtained by cooling in water. In this research we studied the cooling water of granulated slag generated from the process of making cast iron through the blast furnace route. The elemental analysis of granulated slag and of granulated slag stored in water was determined by X-Ray Fluores...

Waste steel slag is a major source of environmental pollution within the metallurgical industries. Metallurgical slags like blast furnace slag, ferroalloy slag, converter slag and copper slag are produced as by-products in metallurgical processes. During the production of steel, one ton of slag waste is generated per every three tons of stainless steel produced. In order to reuse waste steel slag, discharged at high temperature range (1250-1650 °C) and cooled in water, which is named as granulated slag, three diff...

In the current work, the process of fermentative conversion of animal waste and non-hydrolized plant materials (peat) using food waste and ascorbic acid salts as a stimulants is described. The amino acid composition of the biofermentation products was estimated. The possibility of the target biosynthesis for the production of fertilizers and feed additives with the pre-determined properties was recognized. It was shown that the additive of bread making waste with the concentration of 10 wt. % increases the amino a...

To preserve and increase the biological and landscape diversity, it is necessary to have comprehensive information about the conditions and dynamics of changes in the study object, a specific local ecosystem. Nature reserves are created to restore habitats, to protect endangered species of flora and fauna, vulnerable or complex species. Particular attention should be paid to the study of wetlands, a stabilizer of the hydrological regime of ecosystems, and a shaping element of the regional climate. It is proposed t...

One of the significant problems in terms of the mining impact on environment is abandoned (due to various factors) deposits and tailings accumulated on landfills. In addition, one of the most important resources for the development of mining is the inclusion of raw materials (as non-industrial stocks) in the economy. There are two ways to solve these problems: a) to achieve economic profitability of the deposit by improving the technologies of extraction and processing of basic raw materials, and b) to develop inn...

The physical and chemical properties of fine sock filter dusts have been studied. It has been demonstrated that a part of the titanium is bound in hard-to-open anosovite that can be enclosed in a shell of amorphous silicon dioxide. Anosovite can be attributed to the phase that is radiographically characterized as the system Fe = Mn - TiO. It is noted that some of the anosovite particles are in a shell of silicon and zinc oxides, and a part is in a shell of silicon, zinc, and lead oxides. The silicate base of the e...

At the present time, the grinding efficiency of minerals is a topical issue for the mining industry, since the grinding process is the most energy-consuming one. For each granulometric composition of the grinded material and grinding bodies, as well as for a number of other factors, there is a certain dependence, which should meet the highest efficiency of the grinding process. The creation of grinding models using modern technologies will contribute to improvement of the grinding equipment in order to reduce the ...

The NAO index has a strong influence on weather over West Europe and the Mediterranean basin but less prominent over the east part of Europe. The aim of this study is the assessment of the influence of the North-Atlantic oscillation on the snow cover conditions in Bulgaria. The winter (December thru March) station-based index of the NAO is used for the current survey as well as data for snow cover maximums from 10 meteorological stations, 4 of them mountainous, for the main period 1930-2020. The linear relation be...

Inhibition of the coil-helix transition of gelatin and retardation of the gelation process of the system as a whole is an important scientific problem. The solution to this problem will make it possible to maintain the properties of gelatin solutions for a long time without changing their rheological characteristics. In this work, by the method of dynamic mechanical analysis, the dependences of the time profile of gelatin solutions depending on the concentration of 10, 13 and 16 wt.%, as well as the different diss...

In the paper the authors present the study results of rock massif fracture based on the case study of a rockburst hazardous Khibiny deposit. The authors have revealed peculiarities in seismic process at different mining stages over a five-year period. The principal aim was to study the particularities of seismicity occurrence when the deposit is mined by approaching fronts, namely, in the periods between bulk blasts in the docking sections between them. The authors have proposed an approach to reveal the features ...

Oil is produced in the form of an oil emulsion due to the high depletion of deposits and significant water cut in wells. The formation of emulsions can lead to a number of complications in the operation of various field equipment, and sometimes even to emergency shutdowns or failures. Therefore, the study of the properties of demulsifiers and their effectiveness is an important task. The work investigates the surface-active properties of seven industrial demulsifiers produced in Russia, such as: interfacial and su...

Our research reveals the importance of GIS technology for land evaluation. The research was conducted on a piece of land of about 770 ha in Romania, which enjoys a diversity of natural factors. Land suitability evaluation, especially given limited land resources, is an important stage in the assessment of its ecological state and for land use planning. The main goal of this evaluation is to estimate the possibilities of maintaining the optimal natural potential of the soil in the process of a certain mode of use o...

In this paper was used correlations between LST-NDVI, for warmest day, for 2013-2016.Study area, Iasi, is geographically situated on latitude 47 degrees 12 min N to 47 degrees06 min N and longitude 27 degrees 32 min E to 27 degrees 40 min E. The largest city ineastern Romania is Ia?i and the seat of Ia?i county. Land surface temperature, calculatedfrom remote sensing data is used in a lot of fields of science, like: climate change,hydrology, forestry, urban planning, oceanography, agriculture etc. In earlier therm...

European aspen (Populus tremula L.) is fast growing, almost exclusively naturally regenerated trees species, significant for biodiversity, but also with notable financial value. It is prone to browsing damages and rot. Limited information on traits important to wind resistance had been collected so far and used to adapt models predicting wind damages in stands of these tree species. Main storms affect Northern Europe during winter time (when trees are at leaf-less state), however, summer storms are becoming freque...

The paper presents some aspects of an experimental research in which basic recipes have been designed in order to obtain innovative products to be used in construction as finishing coatings. Starting from sunflower seed shells, considered a waste rather a by-product resulting from the industry of edible sunflower oil, and also from rough sheep wool, an animal waste from the zootechnical field, and also from the specific thermal insulating characteristics of theese two waste materials, a serie of basic recipes was ...

Old closed uranium mines can be a significant source of environmental pollution and hazards to human health. The problem could become more severe in time due to erosion if the restoration measures are not properly maintained. There are many uranium mines in Bulgaria that, even closed in the 1990s, could be a pollution source for surface and groundwater in their region. Through hydraulic connections, they can contaminate the rivers passing nearby. The aim of the present work was to check the hypothesis of a possibl...

Soil erosion is the most serious soil degradation on the territory of Bulgaria. Estimated average annual potential soil loss from sheet water erosion in Bulgaria amounts to 902.5 million tonnes. Over 68% of the territory of the administrative region of Kardzhali (East Rhodopes) is characterised by risk of sheet water erosion exceeding 100 t/ha y. The paper presents assessments of susceptibility to erosion of soils in the catchment of the Dzhebelska River (Eastern Rhodopes). The assessments are based on the USLE ap...

Most of the suspension matter transported by rivers derives from the riverbed erosion. Complementary, the anthropogenic factor is responsible for the introduction of significant amounts of sedimentary material, especially suspended, but also dissolved material. In most cases, the distinction between naturally occurring materials and anthropic ones is almost impossible to achieve due to the complexity of the erosion processes. The suspended sediments concentration (SSC) and discharges were analyzed in the Danube De...

The purpose of the research was to develop an algorithm for a comprehensive assessment of the sustainable development of a mining enterprise based on an integral indicator from the standpoint of environmental performance and test it on the example of the largest Russian coal and energy company SUEK. In modern conditions the Russian energy sector is in a state of transformation, which is associated with the strengthening of globalization processes, tougher competitiveness and management of production systems. Moreo...

The effectiveness of rhizobia-legume symbiotic interaction is under the genetic control of macro- and microsymbionts. Both symbionts exhibit high level of genome/genome specificity interaction which is reflected by symbiotrophic indices vary significantly. Virulence and plant dry mass increasing are indices widely used in order to reveal well matched rhizobia strain and variety of legume host plant for practice demand. The aim of the research was to study how allelic polymorphism of symbiotically significant genes...

Carbon foam is advanced porous material with multiple high-technology applications, due to its structure, light weight, high thermal stability, high thermal and electrical conductivity. Potential applications of carbon foam are construction of ship and aerospace modules, rocket nozzles, radar adsorbing systems; fuel cells, battery electrodes, nuclear shields, rods for nuclear reactors; prosthetics, etc. In this work a new method for preparation of carbon foam is demonstated, using precursors mixtures of organic su...

The Romanian storage sites for CO2 geological storage are located in the Oltenia Region, in the south – western part of Romania, within a 50 km radius circle around Turceni Power Plant. This zone comprises a part of the Getic Depression and a small part of the western sector of the Moesian Platform, two of the main geological units bearing oil and gas deposits, which were explored and studied over the years. In this zone of investigation only aquifers in the Tertiary formations have been considered as potentially ...

This publication aims to offer a generalized approach in describing a conceptual mod?l based on the ISO Conceptual Schema Modelling Facility Schema architecture and so-called Systems approach, based on General Systems Theory to establish interoperability at creation, acceptance, maintenance and renewal of the State Levelling Network I and II Order. The basis for proposing this generalized approach is the new Instruction for the establishment and maintenance of the State Levelling Network. This Instruction has been...

Small and medium-sized enterprises (SMEs) of the Russian steel industry perform an important function of innovative development. These enterprises produce unique products in small batches for domestic engineering and implement import substitution projects (e.g., piece products of cast-iron casting for enterprises producing agricultural machinery). At the same time foundry production makes one of the most unfavorable influence on ecology and occupational health. Waste of foundry production and emissions into the at...