Browse

Commonly the intensification of agricultural practices is regarded not only as one of the established techniques for achieving agricultural and food independence but also as the key instrument for alleviating world hunger. Despite its considerable potential, intensification has become a controversial topic that attracts particular interest due to its substantial negative impact on greenhouse gas emissions, biological diversity and natural habitats. This paper aims to explore and compare the degree of intensificati...

The accelerated evolution of the anthropogenic land use together with the involved dynamics of the land use changes has deepen its environmental impact and increased the population demands. The usage of satellite images became in the last decades a complementary method for obtaining structural information on the urban land use due to major developments in domains such as remote sensing, geographic information systems and photogrammetry. Accurate information on urban built-up area is essential for multiple key area...

The use of Earth observation satellite data is an efficient monitoring method for the state of natural ecosystems disturbed by the development of georesources. A permanent multispectral satellite survey provides an opportunity to study the dynamics of ecological restoration by observing the changes in the spectral reflective properties of the landscape. At the same time, it is problematic to interpret the satellite observation data of the surface being in the shade during the survey, because in the absence of dire...

This paper presents three common and simplified steps in conceptual modeling, which are also proposed as “tools” for project initiation. These steps are: 1) system characterization, 2) system structural analysis, and 3) multi-criteria modeling of alternative scenarios. The main motivation for a standardized approach is that that many projects involve complex systems with diverse stakeholders. Both of these aspects increase the need for effective communication and for including perspectives across disciplines and s...

Object. Measurements via borehole inclinometers have been actively used in geotechnical monitoring for more than forty years. Due to the high sensitivity of MEMS sensors to external factors, the passport accuracy characteristics of such equipment are significantly underestimated. At the same time, the analysis and interpretation of data obtained by inclinometers measurements are associated with an assessment of these measurements quality. Identifying the random and systematic components of the total error is the k...

The number of registered cases of COVID-19 is increasing in the world, and some countries are reporting a second wave of the pandemic. Accurate and real time information about epidemiological situation is therefore urgently needed for managing decisions in the countries, regions and municipalities which are affected. Massive testing of viral presence in people’s saliva, a smear from the nose, nasopharynx and / or oropharynx, bronchial lavage water obtained by fibrobronchoscopy (bronchoalveolar lavage), as well as ...

In this study, based on a relatively high resolution wind database (ERA5), an assessment of the nearshore wind conditions in the western part of the Black Sea was conducted. From the reanalysis of the wind datasets provided by the ERA5 product, significant differences between the onshore and offshore wind power were identified, with the offshore regions being more resourceful than the onshore ones. Generally, the appeal of a site for a wind farm project is determined throughout a classification of the wind classes...

In Russia, turning to the circular economy concept is becoming a new wing of theenvironmental industrial policy. In most Russian regions, the necessity of recyclingindustrial waste co-exists with the challenges of municipal waste management. Thus,according to the official statistics, the amount of solid waste formed in 2019 reached7.75 bln tons, 55-60 mln tons being categorised as municipal waste. In 2010-2019,annual waste generation grew from 3.74 to 7.75 bln tons; about 15 thousand landfillsoccupy the territory ...

Ceramic materials based on titania and zirconia hold much promise in modern nuclear energy applications. Such materials due to their chemical and mineralogical similarity to nature-derived minerals may be used as matrices for radioactive waste immobilization as well as inert matrix fuels in the ‘burn and bury’ fuel cycle. However, sintering of such ceramics into a dense body is still a challenging issue. This paper addresses phase formation processes and sintering patterns of ceramics in TiO2 – Al2O3 – ZrO2 – MgO ...

Covid-19 has turned our world upside down and transformed nearly every aspect of daily life, business and travel. The COVID-19 pandemic has had severe negative impacts on human beings in all spheres of economic, social and even geopolitical life worldwide. The impact of this crisis will be the subject of numerous studies in all fields of scientific research in the coming years. According to all official data, the tourism sector is one of the most affected sectors of the economy. Despite the reported partial recove...

This paper presents an exploratory study that analysis the factors that influence the intention to use smart meters that measure electricity consumption. The authors used the technology acceptance model as a starting point for their research, taking into consideration other eight external variables: social influence, familiarity with smart meter technology, task-technology fit, compatibility, the level of trust in companies that supply electricity, price awareness, energy conservation intentions, and perception of...

The studied structure is situated in the Carpathian Foredeep and past geological and geophysical prospecting have proven the existence of a large anticline formation with reservoir proprieties in the SW area of the structure. The prospecting and development stages for this particular reservoir started decades ago, however, recently there have been an intensification of seismic prospecting in order to asses the possibility for an increased production. A large gravimetric study was done at a regional scale that esta...

One of the discussion issues of karstological studies is the identification of karst denudation intensity; it means the quantitative evaluation of the intensity of this process, which, in turn, allows to predict the karst development. The problem of karst denudation is developed insufficiently today, which can be explained by the complexity of the issue and at the same time, the methods used to assess the intensity of denudation are not yet refined. The intensity of denudation and its general regularities in the Z...

Despite all technical and technological advances, most industries are experiencing damage resulting in human casualties and property damage. Thus, the presence of special intervention and rescue teams at economic agent’s units is essential to limit / eliminate damage that generates toxic / explosive / flammable environments and rescue those caught in such events. The intervention activity in such special conditions can be carried out exclusively by trained and authorized personnel in this respect, personnel using ...

The work is devoted to the study of fuel ash as components of composite cements and building mixtures based on them. The use of bottom ash as raw material is an urgent problem. On the one hand, their use in production solves the issue of creating resource and energy saving technologies and increasing the efficiency of cements and concretes. The use of ash makes it possible to improve the properties of cements, bricks, products from aerated and heavy concrete, light aggregates, and the quality of road construction....

Glaciers are sensitive to climate change. How the fluctuation of the temperature affectsthe behaviour of the glacier and particularly its flow and seismic activity is underinvestigation. In this paper, we present a study of activity of glacier Perunika,Livingston Island, Antarctica using data from seismic station LIVV, GNSS data frompoint measurements on the surface of the glacier and meteorological data. GlacierPerunika is the closest one to the Bulgarian Antarctic Base. Seismic station LIVV, issituated near the ...

The last several decades, the climate change, as one of the most serious environmental issues, has become a widely spread topic not only to individuals, but the whole international community. Weather extremities, such as tropical days, summer heat waves, switching of periods of extreme precipitation with periods of drought causing the decrease of water reserve capacities cannot simply be overlooked. Due to alarming climate situation, especially in urban zones, the adaptive measures are much needed, even necessary....

Flying ad-hoc networks (FANET) based on unmanned aerial vehicles (UAVs) are characterized by frequent changes in the network topology, which is caused by switching nodes on and off, as well as their movements in space. These aspects of the FANET operation determine the relevance of the development of new routing protocols, which differ significantly from the protocols of hierarchical networks with a constant topology. One of the key problems of FANET is the high overhead costs for transmitting service messages abo...

There are two main sources of activated carbon production - coal and lignocelullosic materials. Recently, scientists have been focused on activated carbon preparation based on agricultural waste and lignocelluloses materials, which are effective and very inexpensive such as corncob, hazelnut shell, olive stone, Jojoba seed residue, etc. The cake remaining after the oil extraction from Pistacia fruits constitutes about 50% of the initial composition, so any commercial utilization of Pistacia oil should consider the...

The present paper is focused on depollution techniques representative for mining and non-ferrous metallurgy, which will assure a radically changed technological concept for a clean, safe and eco-efficient production, leading to sustainable development industry. At the same time, our works propose the implementation in the mining and metallurgical sector of unconventional processes through innovative techniques that lead to processes intensification, reduction of energy consumption, decrease of carbon footprint, by...

Even with technological development, small formats have been introduced with a photogrammetry technology that offers numerous benefits. The digital imagery for the small-format camera, installed on the lightweight platform, such as Unmanaged Aerial Vehicles (UAV), currently can be extracted from digital maps. The geometry of the Georeferenced Digital Surface Model (DSM), obtained from UAVs, is a multiplex of factors such as flight configuration, camera performance, camera calibration, and SfM algorism. The overlap...

The article analyzes the issue of agricultural development of German-speaking colonists who lived in the steppe zone of Ukraine. The article analyzes the general features and main directions of development of this process and the reasons that caused it. The main attention is paid to the process of transformation of colonial agriculture. Until the 1860s, the most important and profitable branch of agriculture of the colonists was cattle breeding. However, due to rising grain prices, the importance of agriculture in...

Fine particulate matter (PM2.5) is recognized as the most harmful air pollutant in Europe. The PM2.5 toxic effect is not only due to its size but also to its chemical composition. Black Carbon (BC) is one of the components of the PM2.5 that affects both human health and contributes to climate change [1-3]. It is emitted by the incomplete combustion of fossil fuels, biofuels, and biomass. There are no regular measurements of the BC concentrations in Bulgaria. This work presents new results from parallel field campa...

Air pollution in this century is a great challenge, mainly due to the aggressiveness ofpollutants on human health, but also due to their impact on all components of theenvironment, namely: air, water, soil and biodiversity. The development, adaptation andapplication of solutions to reduce air pollution is possible only through a research activity- intense innovation and supported by all those with decision-making power and financialresources. Air pollution and its impact on human health, ecosystems and biodiversit...

In this paper, we consider an algorithm for assessing the stability of a geotechnical system and its individual sections based on a basic model. As a basic model, it is proposed to use a set of models used at the design stage of sections of the geotechnical system. When assessing the stability of individual links of the geotechnical system, and the group stability of the analyzed area of the geotechnical system, the approaches of the theory of automatic control are used, taking into account bifurcation parameters ...

Legumes are a unique source of protein for food and feed industry. Legumes synthesize protein valuable for living organisms using atmospheric nitrogen which they can fix due to their symbiosis with root nodule bacteria. The formation of plant-microbial symbiotic systems depends on complementary interaction of signaling molecules of both symbionts. Rhizobia signaling molecules are lipochitooligosaccharides, so called Nod factors. The synthesis of core part of Nod factor molecule is determined by nodA, nodB and nodC...

Combined sewerage is the most widespread method of wastewater management in the world. Sewage and rainwater are discharged through a combined piping system, which affects overloading the sewer networks during extreme rains. This method of wastewater disposal is the oldest type of sewerage. At present, this method is described as less suitable in opposite to rather on the construction of a divided sewerage system, where wastewater and rainwater flow through separate pipes. The main disadvantage of the combined sewe...

To achieve implementation of sustainable agriculture practices and implement circular bioeconomy in farms, agricultural waste and residuals commonly are used as feedstock for biogas production that is in line with European Union strategy to reduce methane emissions. Anaerobic digestion of feedstock results in production of the digestate. Digestate, on the one hand, is valuable fertilizer that can substitute synthetic fertilizers. On the other hand, it is associated with methane (CH4), ammonia (NH3) emissions and n...

This work presents an empirical model for forecasting the hourly values of the ionospheric E-region critical frequency (foE) over Bulgaria in dependence of both: the index of the solar activity described by F10.7 and the cosine of solar zenith angle. The dependence of foE on solar activity and solar zenith angle is studied by correlation and regression analysis. The obtained relationships are used as a base for the synthesis of the model. The model is produced by using the hourly values of foE obtained in the iono...

Hydrological modeling is the conventional approach to simulate, evaluate, forecast, and react to floods. However, the development and validation of these models are more challenging where the monitoring stations are limited, unevenly distributed, and particularly scarce in many developing countries. Alternatively, satellite images allow detecting the multi-temporal flood extent over large horizontal areas with a cost advantage for hydrological calibration and validation. Many approaches have been explored to disti...

The present study's primary purpose is to evaluate and provide a more comprehensive, unbiased and helpful picture of the Romanian energy potential, highlighting the emerging renewable resources. Firstly, several indices are taken into consideration to underline the Romanian energy portfolio structure. The installed capacities and the country's power generation, carbon dioxide emissions, nuclear generation and consumption, and renewables power are among the critical indices used in this project. The data and result...

During the last decades the extreme hydrometeorological events increased. Respectively the needs for more accurate estimation of the precipitation amounts have increased. One of the opportunities to get denser precipitation data in space and time is through the remote-sensing. Satellite-based products allow obtaining spatially distributed hydrologic variables and could be very useful in the modeling of the elements of the hydrological cycle. A big variety of hydrological models exist nowadays. In this study the fu...

In this paper we present a case study regarding a desert dust intrusion over Central and Eastern Europe in 5th of April 2021, observed using a multi-wavelength Raman and depolarization LIDAR system operated in Cluj-Napoca, Romania. This type of system meets the requirements of the European Aerosol Research Lidar Network – EARLINET and is suitable to provide reliable data on optical parameters for aerosol characterization. While mineral aerosols are the second largest source of aerosol and are the subject of long r...

For craton's areas the most valuated geological object ordinary are situated in river valleys. There are stratotypes, interesting outcrops, unical paleontiological localities. However over time a lot of valuable geological objects lost. The natural and anthropogenic factors are analysed in the article that determine the preservation of specially protected natural areas and, in particular, valuable geological objects on the example of some river valleys of the north-west of the Russian Plate. The article reflects t...

The aim of this study is to identify opportunities for the development of the Latvian forest sector and to assess competition. Nowadays, the development and sustainability of natural resources is of great importance. The forest resource in Latvia is valued as the most important national natural resource. It is therefore necessary to identify and analyse the factors influencing its development. The study included an analysis of the Latvian forest sector exports. The research methodology includes theoretical concept...

Harmful substances like heavy metals are very important group of pollutants which can cause considerable detriment to the environment if they exceed certain concentrations. The aim of this study is to define the concentrations of Cu, Fe, Mn, Pb, As, Zn, Cd and Ni in the waters of the Rivers Pirdopska and Medetska, tributaries of the Topolnitsa River, Bulgaria for the period 2015-2019. In the analysis of the heavy metal content Water Quality Index (Canada), as well as statistical and graphical methods were applied....

This article discusses methods for designing distributed information systems for use in design using the Hyperledger blockchain platform. Of course, the main stages do not differ, but there are also differences that will be identified in the course of the study and a proprietary approach to the implementation of these features is proposed. The request for the possibility of decentralizing business processes in certain areas (such as financial transactions) led to the emergence of distributed ledger technologies, w...

In the present work the researches were carried out between 2017-2020, in the Tata Valley watershed, which has an area of 16.15 sq. km and administratively belongs to Dambovita county, Romania and is located between latitudes of 45o9’ N-45o15’ N and longitudes 21o21’ E-25o27’ E. The methodology used for processing the basic data from 2017-2020, was the adaptation of the USLE equation (Universal Soil Loss Equation) to the specific environmental and anthropic conditions in Romania and called ROMSEM - Romanian Soil E...

In addition to the traffic load, the temperature also has a significant effect on the course of stresses in cement concrete slabs. It is the load of temperature changes that is often underestimated. Recently, there have been significant changes in climatic conditions and increasingly frequent extremes (especially high temperatures in the summer months and extreme fluctuations during the day), which affect the behavior of road structures and the basic characteristics affecting the stress of cement concrete pavement...

Waste treatment is considered one of the critical environmental issues. Waste should be understood not only as a source of pollution but as a raw material. Nevertheless, we need well-sorted waste for recovery. Separate collection of municipal waste is an activity in which components of municipal waste are separated. It is based on the conscious activity of citizens, who primarily sort the relevant raw materials. At present, the citizen is obliged to sort waste by law in Slovakia, and the municipality is obliged to...

Combined sewer are among the most important objects of a unified sewerage network and therefore high requirements are placed on these objects, whether from hydraulic, hydrological, hygienic or constructional requirements. Their main function, ie hydraulic, is to divide the inflow at the time of torrential rains into a flow continuing to the WWTP and a flow that is relieved from the OK to the recipient. Another important function of relief chambers is related to pollution. Some chamber designs can successfully capt...

Quarry sites are famous for the different types of materials produced. Many aggregate elements, extracted by different methods in quarry activities, such as blasting operations, are widely used for different applications, such as construction, road paving and monuments. Generally, the process to obtain these materials is very complex. A stationary production facility does not require machinery to be moved or relocated, whereas the quarry process involves machinery such as wheel loaders, trucks and articulated dump...

In 2020, China and India accounted for two-thirds of global coal consumption, while the European Union and the United States accounted for only 10%. Coal consumption in Southeast Asia has now surpassed the European Union and will soon surpass the United States. Now the global coal trend is mainly influenced by Asia. Changes in the demand for coal in China are closely related to economic growth, but in different periods of the development of China's industrialization, the degree of dependence of economic growth on ...

Textile production is considered one of the most polluting industries with a high impact on the environment, both in terms of increased resource consumption and textile waste generation. Moreover, in the past years, the textile industry registered a significant growth, which leads to large amounts of textile waste that need to be controlled and managed. This problem highlighted the need for sustainable methods and improved technologies for textile recycling, and brings into focus the importance of circular economy...

This work is devoted to the feasibility of implementing capture and sequestration projects (CCS) in Russia, as well as to evaluation of the positive and negative aspects of implementation of CCS projects as a climate change mitigation technology. The study focuses on the current state of the problem of CO2 capture and disposal and considers possible implementation of CO2 sequestration projects in Russia. The negative and positive factors of CCS technology are also identified. The conclusion provides arguments for ...

Thermal conductivity plays a crucial role in the design of external walls of buildings. This paper is focused on measuring the thermal conductivity coefficient of blocks made of structural lightweight waste aggregate concrete. The concrete mixture contained waste red ceramics fine aggregate and artificial expanded clay coarse aggregate. Replacing conventional aggregates with waste aggregates is one of the possibilities for the sustainable design of concrete construction today. A nondestructive method using the ISO...

Ensuring information security in various infrastructures is extremely relevant, due to the increase in the number of automated workstations (AWPs). The article discusses and analyzes the market of single-board computers, as the main computer, as well as their functionality, disadvantages, advantages over stationary PCs, uses to protect information. It is possible to assume that the relevance of the topic in the modern world will only increase every year. There is a general trend around the world to reduce the size...

Water management in karst areas is a challenge as the regime of waters is generally characterized by substantial temporal variability. Water balance analysis is a necessary part of hydrogeological research. The aim of the paper is to study specific features of the water regime and balance of karst springs from the Lovech-Tarnovo karst basin, as well as to evaluate their recharge area. For monthly water balance calculations, the software WaterbalANce was used that is based on the Thornthwaite–Mather method. In addi...

With the development of GNSS, one can easily obtain gravity disturbances at almost every point on the Earth’s surface. Thus, the use of gravity disturbance in geoid modeling becomes more appropriate than the use of gravity anomalies that require leveling in the points. For this reason, here is presented the basic theory for the application of radial basis functions for geoid heights modeling and in particular a Hotine-Koch scaling function for calculation with gravity disturbance. The report aims to test the appro...

Emissions of fuels combustion are one of the main causes of smog formation andgreatly contribute to the increased CO2 emissions in numerous countries. Many citiesdecide to introduce restrictions on the usage of fossil fuels or even completely ban them.To analyze fuel used in households, it is necessary to gain access to the chimney outlet,which may prove difficult. The following article presents the current usage of drones inthe search and analysis of these sources. It presents existing, commercial solutions, aswe...