Browse

The hydrocarbon reservoirs in mature regions are extremely complex, each reservoir having its own identity. The value of recoverable geological reserves depends on the data of geological and geophysical studies: determination of heterogeneity and reservoir compartmentalization. Residual oil reserves are concentrated in undeveloped clayey, poorly permeable intervals along the section, the development of which is impossible without research and development. One of such studies is the methods of lineament analysis of...

The present study focuses on the assessment of station corrections for eleven seismic stations from the national network of National Operative Telemetric System for Seismological Information (NOTSSI). Station corrections are obtained by calculating the ratio of the spectrum of the horizontal components of the signal to the spectrum of the vertical component (H / V). Records of S-waves from 20 local and regional earthquakes are analyzed. The values of A0 - site-effect and f0 - resonant frequency were obtained. Acco...

Buildings, including public sector buildings, are the largest consumers of energy re-sources. The aim of the work was to assess the energy saving potential of state consum-ers of the municipal territory in order to determine the efficiency of energy consumption in individual buildings and to determine the directions of the most profitable investment to improve energy efficiency. An analysis of the specific consumption of 23 buildings managed by the municipality of Yakovlevsky district of the Belgorod region (Russi...

The present study is aimed to assess the status of Black Sea fish species harvested by the Bulgarian fishing fleet, according to the three criteria of Descriptor D3 under the Marine Strategy Framework Directive (MSFD). Achieving healthy fish populations depends on the adverse impact on species as a result of fishing activity. Descriptor D3 of MSFD addresses the commercial fish stocks status by applying indicators assessing the exploited fish sustainability, reproductive capacity and recruitment, and the age and si...

The study of seismicity in the Black Sea region is of particular interest for assessing the vulnerability of the surrounding coastal zones to strong earthquakes and their consequences. The seismicity pattern in the area is determined by the geodynamic processes along the boundaries of the Eurasian, Anatolian and Arabian tectonic plates. The paper presents an approach to assessing the seismic activity of the Black Sea and the surrounding region covering historical and recent seismicity. The historical events since ...

Snow cover is an important factor in mountainous regions regarding water resources, vegetation and economic issues for the ski and spa resorts. Snow is also an indicator of the fluctuating climate, resulting from the change in the regime of winter precipitation and air temperature. This study is focused on the changes in the regime of the snow cover in the Vitosha mountain. The monthly values of number of days with snow cover, seasonal maximums and monthly averages of the snow cover from 5 meteorological stations ...

The article is about three hydrological river routing models (RRM) implemented in Bulgaria, coupled to a land surface model (LSM), mainly for flood forecasting purpose. For the evaluation of the three RRMs the authors use a river basin of Mediterranean climate - the Varbitsa River with catchment area of 1200 km2. The river is prone to dangerous flash floods because of their fast propagation. LSM SURFEX (Surface Externalisee) but formally the integrated part ISBA (Interface Soil Biosphere Atmosphere) is used to com...

Data analysis for multiple data source locations on the wave climate regime of the Western Black Sea Coast is significantly required in port design as well in the delineations of the sheltered conditions, various emergency situations in maritime port areas. Under the extreme wave’s regime circumstances, there is a limited possibility to find certain low-energy areas for ships sheltering. The wave regime presents specificities of the wave field generated by the wind, especially in the port adjacent areas, under the...

Changes in market demand inevitably lead to changes in the assortment policy of oil companies. It is necessary to change the production capacity at the enterprise and the sales policy, demand profitable types of products that will be in demand among consumers. The competitive strategy of oil refining companies is currently largely determined by the drop in total global demand for dark oil products and the high rates of development of petrochemicals. The focus of the paper is on analysis and development of assortme...

The southern part of the Bulgarian Black Sea coast is characterized by numerous nature protected areas with high biodiversity, picturesque seashore landscapes and small villages that attract many tourists in summer. Despite the fact that the region is distant to big emission sources of anthropogenic pollution, air pollution and deposition can be significant for specific pollutants and seasons [1-2]. The main goal is to discuss recent data for dry depositions of oxidized nitrogen, reduced nitrogen and sulphur for t...

The main cause of Albanian seismicity is the collision of Adria microplate with the Albanian orogeny. Albanian territory is characterized with high level of seismic hazard in the Europe. It is very important to emphasized seismic zone of Durres that generated a strong earthquake M6.4 on 26 November 2019. During the 2020 year, seismic activity at the Albania territory and its surroundings was characterized by a normal seismic activity. Earthquakes foci are concentrated mostly along the five active fault zones: Fier...

Nowadays, along with creating materials with enhanced mechanical characteristics, it became important in the light of ecological problems, to design eco-friendly materials capable to disappear with time after fulfilling functions, in other words to develop biodegradable mechanically strong materials. The chemistry and technology of biodegradable polymers is one of the most important and rapidly developing fields of modern polymer science. A lot of biodegradibel polymers (BPs) were created mostly for medical applic...

Global trend to renewable and green energy application instead of fossil fuel results in grows of bioethanol production and its application in transport and industry. Typically, bioethanol can be used as motor fuel purely and in blends with hydrocarbons, however bioethanol fuel containing less energy compared to traditional gasoline. A possible solution to this disadvantage can be catalytic transformation of bioethanol into hydrocarbons. Bioethanol can be transformed into hydrocarbons over different zeolites inclu...

To prove adverse impacts exerted by drinking water and to assess regularities in occurrence of health disorders caused by contamination burden on the body, experts from the Center performed complex chemical-analytical and medical-biological examinations of children who lived on an exposed territory and consumed drinking water with chemical contents exceeding hygienic standards: N-nitrosodimethylamine, by 1.6 times; chloroform, by 5 times; dichlorobrommethane, by 26 times; and children who lived on a reference terr...

Our planet experienced many intervals of climate deterioration due to terrestrial causes, such as intensified volcanism and a very active tectonic regime or extraterrestrial causes. The later includes major meteorite impacts and change in the exosphere, mostly linked to the modification of sunlight amount leading to glaciations. The most sensitive organisms to climate changes are the marine planktonic ones, especially the coccoliths and dinoflagellates. This paper describes modification in the marine planktonic wo...

Bird studies in urban parks support our better understanding to impacts of urbanization on natural forest habitats. This study is based on field census of nesting birds in urban parks of Olomouc heritage city (Czech Republic). Bird community in urban parks was compared with previous author?s bird study in hardwood floodplain forest near the Olomouc city. For characteristics of bird communities, Jaccard index, standard diversity index and equitability index were used. Comparison indicated high similarity of bird di...

The paper solves the problem of creating a device for electrical measurements for the purpose of geological research. There are a large number of data acquisition and processing systems, analog-to-digital converters (ADC) and other serial processing technical means for measuring and storing analog electrical data with their preliminary conversion into digital readings. This is done for the purpose of subsequent processing of these signals, which allows calculating some characteristics, which are then used to calcu...

This article offers an innovative method for deriving curricula for tomorrow’s workforce in the geospatial sector, considering the market requirements through modelling business processes, identifying and analyzing occupational profiles. The idea behind this approach reveals business processes models described by workflows of tasks that workforce needs to master in their daily work. In addition, business processes show who is involved in projects and needs to communicate with one another, and how the information i...

Riparian forests are important ecosystems providing a spectrum of ecosystem services such as erosion control, nutrient modification and improvement of water quality in adjacent streams. In many countries management of riparian forests are restricted to protect aquatic biota as vegetation, especially woody plants provide nutrient uptake from soil preventing stream water over-enrichment. However not all tree and ground cover vegetation species carry the same positive effect on stream quality. Aim of our study was to...

Walking is the oldest way of transporting a person from place to place. Nevertheless, in the last decades, insufficient emphasis has been placed on it when planning the development and renewal of settlements in the Czech Republic. In recent decades, public space has been purposefully adapted to car traffic, which degrades it aesthetically, functionally, and air quality. This approach has been gradually changing in recent years. Large cities are once again turning to walk as a basic way of transporting people and a...

One of the circular economy’s principals is to «keep products and materials in use». Geopolymerization technology is promising enough to support this principle as it exploits wastes and by-products as alternative raw materials streams. However, the challenge that must be overcome to commercialize geopolymers is the substitution of the caustic alkaline solution that activates the aluminosilicate raw material. The introduction of solid activators in the process has given great results. This paper deals with the synt...

The production of tiling and building ceramics is based mainly on the traditional system clay-silica-feldspar. However, in recent decades it has been demonstrated that some of these raw materials can be successfully replaced by various industrial wastes. Because of the high feldspars price a significant part of these studies was based on the usage of different alternative “amorphous” fluxes (as glass culets, TV cathode ray tubes, basaltic tuffs and others). Unfortunately, the addition of similar materials in amoun...

advance has provided humanity request to raise its quality of life, registered trends anyhow pointing out that technical advances could bring not only desired impacts but also objectionable ones. For finding appropriate answers to recognized challenges the concept of sustainable development has been defined. By considering made progress in mobility field, the current vision is to succeed shaping human mobility not only on a global level, but also on a cosmic one. This seems to be possible by enlarging the idea of ...

Urban areas are very dynamic environments, subject to continuous expansion and growing population, with land use changes influenced by the needs and dynamics of the population. Using remote sensing techniques applied to Sentinel-1 GRD images, some change detection patterns could be revealed for Bucharest city, for a period of three years (2016-2019). As the largest city in Romania, the main university center and the most important industrial and commercial center, Bucharest offers a wide range of educational, inve...

Integrated assessment of ecological status and ecological well-being of water bodies based on monitoring presupposes attributions of the aquatic ecosystems to definite gradations of trophic state and level of pollution. In really these attributions are carried out by means of multi-criteria evaluation. The evaluation uses a number of parameters. Each of them must be indispensable, and the parameters taken together must be sufficient for the precise evaluation. Of course, each of the parameters must be suitable for...

The topic is up-to-date, related to the full use of organic materials in crop production and livestock breeding. This is part of the goals of the circular economy and is successfully linked to the need to maintain a positive balance of soil organic matter in agricultural lands. The problem is an important issue for sustainable agriculture on arable land but has a different meaning in different soil types. Organic fertilization is an effective method for maintaining soil fertility. Two soil types were used - Luviso...

Legumes are nutritious ingredients that can be used in bakery industry. However, in order to minimize their antinutrients contents and unpleasant flavor, germination can be applied. The aim of the present paper was to investigate the proximate composition and minerals profiles of composite flours made of refined wheat flour and germinated legumes (beans, lentil, soybean, chickpea and lupine) in different levels. The results showed an increase of protein and ash contents as the addition level was higher, while a re...

Environmental pollution in industrialized regions has a negative impact on public health status. Excessive accumulation of heavy metals in the human body induces disturbances in the adaptation processes to changes in the quality of the environment, including changes in the immune, humoral and nervous regulation, which can lead to the early development of ecologically caused pathologies in children. Purpose of work: to study the peculiarities of the immune profile of the child population in an industrialized region...

In the context of global climate change and the increasing anthropogenic impact due to the process of intensiveness of nature management in the Arctic coastal eco-socio-economic systems, there is an increase in the production of risks of natural and anthropogenic origin. The purpose of the paper is to substantiate and develop a classification system of risks of Arctic coastal nature management, sources and factors of their production as well as possible relationships between structural elements, which makes it pos...

The climatology of hot days and extremely hot spells on the territory of Bulgaria has been studied on the basis of daily data for maximum air temperature during the warm half-year in the period 1961–2019 from 115 meteorological stations of the National Institute of Meteorology and Hydrology (NIMH). The empirical distributions of daily maximum air temperatures by selected stations representative of the non-mountainous regions of the country (below 1000 m altitude) have been investigated to determine the correspondi...

The focus of this study is detection of the deformations of the Earth's surface caused by March 3 2021 earthquake using Differential Interferometric Radar Synthetic Aperture technique. This method takes advantage of the remotely sensed SAR data provided at no cost by ESAs’ Sentinel-1 mission which are often used for creation of topographic maps as well as for detection of ground motions. The final results of this processing deliver reliable information about the displacements caused by the mentioned events with ce...

Coal production in the Socialist Republic of Vietnam (SRV) is a strategic industry that provides resources to many sectors of the economy, including the energy industry, metallurgy, and construction. The distinctive characteristics of the Vietnamese coal industry are a high concentration of operations, the depletion of readily available reserves, and, as a result, an increase in underground mining activities, which already account for more than 60% of coal production. Coal mines belonging to Vinacomin, which is a ...

Violation in technologies of using and storing the organic animal husbandry waste is leading to deterioration in soil sanitary state and agrocoenosis. As a result of increased biological pollution, soil self-cleaning ability is decreasing, which leads to negative changes in its biological diversity and biological activity, arrival of toxic compounds in high concentration, deterioration in vegetable cultivation products quality, state of environment and human health. In this regard, evaluation of the soil sanitary ...

Malt is the essential raw material for beer production. Currently, in Europe the most used cereal for beer is barley due to its many advantages in the manufacture of malt. Recently, research has intensified to replace this raw material for beer with other cereals or pseudo-cereals. These include buckwheat which does not contain toxic prolamins to celiac disease patients. Buckwheat is an annual plant of Polygonaceae family and is produced in many countries for its characteristics such as high economic value, easily...

Eleven stations of the Bulgarian seismological network - National Operating Telemetry System for Seismological Information have been used for an assessment of the stations' corrections (site effect), to account for the impact on the seismic waves of the low-density layer immediately below the seismic stations, amplifying the signal. Nakamura's method for calculating the ratio of the spectrum of the horizontal component to the spectrum of the vertical component (H-to-V) is applied. Data from 20 local and regional e...

The presented paper deals with the issue of assessing the condition of winter wheat (Triticum aestivum L.) stand during its development in the spring period. The field experiment was established in 2020; two plots sized 25 ha and 16 ha were selected with a model plant of winter wheat. In the spring period (BBCH 35 and BBCH 51), both plots were monitored using an unmanned aerial vehicle (UAV) and Sentinel 2 satellites. After the end of the monitoring, spectral analysis of pictures taken was made and a basic NDVI ve...

Modern town and regional planning was shaped institutionally under the conditions of industrialisation and the associated growth in the economy and population in towns and industrial agglomerations. The aim is to manage this growth and create the conditions for its continuance with the smallest possible negative impacts on conditions. The main resources for ensuring problem-free growth consists of seeking out suitable areas for the construction of new housing and industrial plants, and the regulation of constructi...

The use of electrical equipment in potentially explosive atmospheres requires special attention, namely from the point of view of their construction and maintenance. Together with the technological developments, these objectives can easily be met, objectives which are defined by European standards concerning the construction, use and maintenance of explosive proof equipment. Evaluation of explosion-proof protected electrical equipment in scope of certification is extremely important considering the risk of explosi...

Although intensification of agricultural practices is traditionally viewed as one of the quickest way of achieving food independence, the increasing demand for energy and unsustainable development of agriculture are detrimental to natural habitats and decrease biological diversity. Organic farming offers a viable alternative and has the potential to facilitate the gradual expansion of environmentally friendly technologies. By carrying out the analysis of statistical data on the value of organic production obtained...

GNSS technology evolves at a fast pace and, along with it, the number of applications that are based on this technology increases. An important part of the applicability of GNSS technology is in the field of geodesy. In this article we propose to present a GNSS system that is built starting from the U-blox ZED-F9P receiver, integrated on a development board produced by SparkFun that is connected to the Raspberry Pi 4 Model B single-board computer. The Raspberry Pi computer and the development board made by SparkFu...

The paper deals with an analysis of the settlement of a tank. The tank has a diameter of 18.6 m and a volume of 1760 m3. The subsoil consists of soft sandy clays and clays of low to medium plasticity. The tank has been founded on a slab of a thickness of 0.2 m. A consolidation layer of compacted gravel of a thickness of 1 m was created immediately below the foundation slab. The soft subsoil was improved using the stone columns. The stone columns were installed using vibro-replacement bottom feed technology. The st...

The study aims to assess the diversity, density, and heterogeneity of seafloor litter, distributed in the Bulgarian Black Sea’s shelf area. The indicators for assessment follow the national monitoring program under Descriptor D10 of the Marine Strategy Framework Directive. The survey campaign took place between 19.10 – 14.11.2017. Marine debris was gathered by 53 trawl hauls distributed in four regions at depths between 30 and 100m. During the survey, all litter items were collected and classified into seven categ...

The determination and modelling of the territory is common scientific instrument for presentation of the state of the nature and human systems. The present research is based on the morphological and hydrological peculiarities in the river catchment. It observed of the Danube coastal zone in Bulgaria sector of the river. The differentiation and determination of the coastal area is key element in the process of the management of the territory and development of the regions. The general results of the research are re...

Doubtless, the application of UAV is a new iteration of remote sensing technologies applied for obtaining information about the object of investigation. An opportunity of fast data acquisition for a large area of research provides to reduce the costs and expand the scope of application. One cannot deny that this approach is actual for geophysical methods of investigation, for aeromagnetic exploration particularly [[1]]. One should note here that process of adaptation of magnetometer sensors for UAV gets a new requ...

Mining is a very heavy industry. Every day miners take incredible risks to extract valuable ores and minerals from the earth's crust. In order to ensure the safe operation of the underground, adequate ventilation is required to ensure that the workplaces are permanently supplied with fresh air. By combining general ventilation with kilometers of secondary ventilation specific ventilation pipes, mining ventilation is a special area where errors can occur. Modeling and simulation of mining ventilation networks have ...

In the North Bohemian region in the Most Basin, brown coal quarries are gradually completed and subsequently closed at present time. The planned and implemented process of reclamation of the area affected by surface mining of brown coal consists in the creation of artificial lakes and afforestation of their surroundings. The Most Basin has a character of a graben, especially its central part. The area of the basin is closed between the Ore Mountains and the Bohemian Central Mountains. In a relation with this ortho...

The only one natural gas storage in Bulgaria - Underground Gas Storage Chiren requires modernization and development. A set of activities have been planned and implemented, covering research, technological and production activities. An overriding task and a top priority are to increase capacities - in volume and productivity of the storage. The aim of the research is to determine the necessary modern set of knowledge that will draw the attention of stakeholders to the possibility of modernization and increase the ...

The data obtained from the monitoring of the dam’s behavior, allow to make the decisions to start the current maintenance works at the best moments of time. They also make it possible to know from early stages possible atypical behavioral phenomena and to take measures accordingly before such phenomena become dangerous for the safety of the construction. One of the ways to monitor constructions is to perform geodetic measurements at different stages and to compare the coordinates obtained in a coordinate reference...

The article is devoted to the problem of cleaning and disposal of waste from mining enterprises of the Russian Federation, using the example of the production of alumina (aluminum oxide). The problem associated with the efficient use of industrial waste as sorbents for the purification of wastewater from mining enterprises is considered. A method is proposed that meets the requirements of the purification efficiency in terms of environmental and economic parameters. The substantiation and proof of the expediency o...

The subject of this study is the development of a web-based system for real time data tracking and applying GNSS corrections in GIS environment. This includes the data structures specification in a geospatial database, obtaining a methodology for system realization and discussing the results with an accent to the accuracy of the corrected GNSS positions. The system for tracking and applying GNSS corrections in GIS environment is entirely built by using free and open source software and has web-based interface. The...