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The Bistrita River was the first river harnessed for hydropower purposes in Romania, starting with 1960. Currently, on this river, 29 hydropower plants with different capacities are functioning, producing about 10% of the entire Romanian electric energy from hydro. Many of them were realized in series, in cascade. In the present paper, the area of Pangarati, Vaduri, Batca Doamnei, and Reconstructia hydropower lakes was analyzed. Of these, three are Nature Reservations, Nature 2000, RAMSAR sites. The lakes being re...

In order to properly manage water resources in a river basin, it is necessary to identify trends in the evolution of rivers flow. Long-term trends analysis for river flow in north eastern part of Romania is based on two different methods: non-parametric rank-based Mann?Kendall (MK) test and innovative trend analysis (ITA). These two methods were applied for 7 hydrometric stations located in river basins unaffected by hydro-technical works, with hydrological observations on the average flow for the period 1950-2017...

The current global climate variability is leading to significant changes in meteorological and oceanographic elements. A climatic background is formed, under the direct influence of which the reservoir affects the climate. The aim of the study is to create a method that can assess the combined impact of the main climate elements for a specific time interval and region. The following parameters of hydro- and meteorological elements are selected as the characteristics of such background: arithmetic mean and correspo...

In the case of process of mining of mineral resources as disintegration of variety of materials is always crucial to choose optimal technology to prevent wastes in energy, human resources and also financial resources. It is also essential to avoid negative impacts on the nature and prevent serious damages in environment in general. This article is focusing mainly on the various ways of mechanical disintegration of materials without usage of blasting in the mining condition (surface mines, coal mines, tunnel boring...

The pollen record from a 96 cm long sediment core obtained in Lake Arcto-Pimberto (68°26.114' N, 053°32.311' E, Pechora river delta, Nenets Autonomous Okrug) reflect regional vegetation and climate changes in the north of the Eastern European plain over the last 6000 year. The taxonomic and stratigraphic structure of the column of bottom sediments is reflected in a spore-pollen diagram which was divided on the 4 biostratigraphic sequences - pollen zones (PZ I-IV). The results show that the bottom of the core (PZ I...

Making marine renewable energy projects in the Black Sea is a subject discussed more and more lately because of the potential of this area. Various studies show that the western part of the Black Sea basin is characterized by high potential from point of view of the wave and wind energy. Because of the favorable wind conditions, offshore wind farm projects can be implemented in this area. In order to make all the maintenance activities in safe conditions, and also the shipping operability between the offshore wind...

In the 21st century, the competitive advantage of many successful companies is great employees who work remotely. However, so far this has not been a common practice in companies in Latvia. Today, remote collaboration is a reality and often an economic asset provided by the World Wide Web. However, business leaders often are indecisive between remote and onsite teams to performing a given task. The events that started in the beginning of 2020 showed an extraordinary transition from onsite work to working remotely,...

The aim of this paper is to study and classify the types of shores of the Alakol lake according to the prevailing exogeodynamic processes and recreational conditions for planning various types of recreational activities. Coastal classification was carried out using the methods of decoding satellite images, field monitoring studies, analysis of archival stock materials, including geomorphological, geological and topographic 1: 200 000 scale maps. Criteria as genesis, age, lithology of soils, the predominant type of...

The decision making theory finds its application literally at any field of science, especially at geosciences, because working with natural resources requires the most accurate tools. This paper considers one question of the given theory, which is called the solution priority problem. The priority problem in multi-object optimization is quite complex, many authors understand it in their own way. Perhaps this is because now the theory of multi-purpose optimization is in its infancy: there is no holistic understandi...

The paper aims to address the importance of inspection and maintenance of electrical equipment used in liquefied petroleum gas car filling stations. In order to maintain in operation the electrical equipment in environments with potentially explosive atmospheres under harsh conditions, the personnel involved in inspection and maintenance activities must be trained in such a way as to know the operation of these electrical equipment with different types of protection and how to perform their maintenance. Inspection...

The dike rocks under study are localized in Mesozoic (T3-J2) clastic rocks in the western part of Verkhoyansk-Kolyma fold area. Studying the nature of the dikes and geodynamic setting of their formation is of great interest now in view of the controversy surrounding their assignment to definite magmatic complexes of the Verkhoyansk-Kolyma fold area and the uncertain origin of mineralization in the Yana-Kolyma gold belt. Major elements were determined using the silicate analysis of magmatic rocks. The mineral compo...

This paper aims to explore the efficiency of energy consumption on farms of different economic sizes in Latvia. Burning fossil fuels to satisfy a continuously growing demand for energy created by the industry, transport and households has been a cause of concern for several decades. It has been widely acknowledged as one of the major reasons for a massive increase in greenhouse gas emissions, a dramatic rise of global temperature and ongoing climate changes. Since farms use energy not only directly by operating ma...

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...

It is known that laminated wood structures are widely used in construction industry due to the advantages of the resulting monolithic composition. However, despite the large number of positive qualities, wood as a filler has certain disadvantages that can reduce the service life of products made of a wood composite material. Thus, wood filler in the process of hardening and drying of composite material, as well as during operation of structures made of this material, can alternately shrink and swell depending on a...

Regression analysis is widely used in situations where it is necessary to determine the dependence of a certain quantitative (continuous) variable on one or more other quantitative (continuous) variables, so-called regressors. It is necessary to determine in advance which variable is independent (explanatory) and which is dependent (explained). The aim of the regression analysis is to describe this dependence using a suitable mathematical-statistical model. The presented paper aims to find the possibilities of usi...

A high-quality environment is becoming absolutely necessary not only for the health of the population, but also for the good functioning of the economy and the availability of natural resources. The aim of environmental policy and instruments of environmental policy is to ensure the required quality of the environment. Environmental aspects have become an essential part of the decision-making processes of developed European countries. Environmental management has not been implemented separately from other economic...

Jurisprudence and international cooperation in the field of pollution of international and regional watercourses have registered over time a rapid evolution if we refer to the documents issued by international and regional bodies that against the background of environmental disasters have come together and developed a series of tools legal and international vocation aimed at preventing and limiting the pollution of water resources. At intra-Community level, in order to prevent and limit the pollution of watercours...

The trend of improving the properties of the used materials also extends to the field of road construction. The research focuses on materials and technologies that immediately improve several properties of asphalt mixtures and at the same time reduce the energy requirements during the production, laying and compaction of asphalt mixtures. When comparing the energy consumption consumed in the production of one t of a mixture (HMA, WMA), it is possible to save at least 15 % of costs and CO2eq emissions [kg/t] up to ...

Industrial size reduction processes such as crushing and grinding play vital roles in rock quarrying. The present study states real field data concerning secondary crushing operations through the cone and horizontal shaft impact (HSI) crushers. In this regard, a total of 44 case studies were collected from several rock quarries located in various parts of the world. Based on the field data, crushing performances of the cone and HSI crushers were compared by statistical analyses. The statistical analyses demonstrat...

The long-term and high-level anthropogenic load on the aquatic ecosystem increases the probability of its adverse transformations (violations of the natural stability of its state and, as a result, the appearance of negative situations). These include diverse geochemical, biogeochemical, pathogenic biological, and, ultimately, medical and environmental consequences caused by the entry and further redistribution, and accumulation in water of highly toxic chemicals, among which heavy metals such as mercury take prio...

The econometrical time series are under investigation in this paper. The mathematical models describing connections between two time series in the form of VAR(p), Vector Autoregression, models are investigated. Their connection is confirmed by means of cointegration tests. If connected time series are described with some models (here the ARIMA, Autoregressive integrated moving average, models) with certain lag orders it?s assumed that maximal orders of ARIMA models are the upper limits for the orders of the VAR mo...

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...

This work focuses on the use of projective geometry methods to determine star positions produced on the basis of positional observations. As is known, projective geometry studies invariant projective transformations. The main feature of projective geometry is the principle of duality, which adds elegant symmetry to many designs. While the properties of the figures that Euclidean geometry deals with are metric, but there are figures that can be converted into one another by movement while maintaining the metric pro...

The quality of indoor environment in buildings is one of the key factors of user satisfaction, as it affects their health and well-being. The indoor environment comprises of several components; the chief among them being the thermal and humidity microclimate, lighting, acoustics and indoor air quality. These can also be summed up by the term ?building physics?. The quality of the final indoor environment is largely decided in the initial phases of the building design. The spatial and material configuration of the ...

Currently, systems for encapsulating drugs are widely used to obtain drugs, since they provide both the preservation of the activity of the administered drug and the reduction of side effects from its administration on the gastrointestinal tract. Complexes of natural polysaccharides such as chitosan alginate and chitosan pectin are widely used as such carriers. These complexes have high biological resistance and biodegradability. In addition, they provide the release of the drug at neutral pH values, which corresp...

In the present work the dependence of macro- and microelements content in plants on the level of soil contamination with heavy metals is estimated. The influence of different concentrations of lead (Pb), zinc (Zn) and cadmium (Cd) in Sod-podzolic soil and Chernozem on the elemental composition of agricultural crops (wheat, barley and alfalfa) depending on their biological characteristics has been studied. It has been shown that as a result of excess metals intake into plant organisms there are violations of the me...

The article discusses salt-affected soils in the south of Eastern Siberia around Lake Baikal. These soils occur in intermontane depressions and foreland basins. The difference in the genesis and chemistry of soil salinization in the western (Cis-Baikal), central (Baikal), and eastern (Trans-Baikal) parts is associated with specific regional features of the geology, hydrogeology, and relief. The deep closed Cenozoic basins of the rift zone in the central (Baikal) region contribute to the advancement of steppe lands...

Silicon carbide is a promising material for heat-loaded units due to its high strength at elevated (up to 1500 °C) temperatures and excellent thermal conductivity. Silicon carbide ceramics is widely used for structural applications, yet production of such materials belongs to extremely energy-consuming industries, thus it becomes an important task to carefully adjust ceramics compositions and methods of manufacturing. The present paper discusses the correlation between mechanical behaviour (dependent variable, cal...

This article shows the geochemical studies of associated produced reservoir water of the Bobrikovian horizon by the area of research at one of the deposits of the Republic of Tatarstan. The horizon is characterized by terrigenous rocks, which in turn is underlain by a massive carbonate reservoir. Quite a lot of producing wells work for it, and also, in view of reserves development, a system for maintaining reservoir pressure has been introduced. Based on the composition of the produced water, maps of the distribut...

This paper seeks to analyse the prospects of locally grown soya in substituting imported soybean meal used in pig feeding in Latvia. Soybean meal is a superior source of protein in compound feeds due to its high protein contents and amino acid composition, but the EU is vastly dependent on the import of plant proteins, with the imports of soya for feed dominating. Latvia also imports considerable quantities of soybean meal that is close to the total production of local protein plants. Owing to potential economic b...

In this paper, a computational method to predict the corrosion resistance of some sintered iron alloys subjected to a thermochemical treatment is analyzed. The proposed materials are obtained by powder metallurgy (P/M) route. The raw materials are prepared from atomized pre-alloyed iron base powders. The compacted samples were obtained by cold pressing using conventional route. The powders were compacted at a pressures of 400 and 600 MPa. After pressing, the green compacts were sintered in a laboratory furnace. Th...

The pulse gas preparation unit is an important part of the compressor station. The quality of the pulsed gas sent to the needs of the entire workshop depends on the degree of its purification from acidic impurities, such as CO2 and H2S. This process takes place in an absorption column. The use of industrial control systems at such enterprises makes it possible to control processes remotely. At the same time, both technical and economic costs of production become less. The impulse gas preparation unit must ensure u...

Recently, zeolites have attracted a significant interest due to their potential use in a wide range of applications related to water treatment and environmental remediation. The chemical and thermal treatments are the most used approaches to improve the zeolites properties by enhancement of sorption properties, surface area and porosity. Chemical (2M NaCl), thermal (150 °C for 24 h) and thermo-chemical (2M NaCl, 150 °C for 24 h) activation methods for a natural clinoptilolite based zeolite originated from Romania ...

In the Ropazu district at Latvia, a set of dolomite excavation quarries is located. Because the quarries must by drained by pumping out groundwater, depression cones appear in the quarry areas and around them. The research targets were investigation of the interaction between the quarries, evaluation of adverse changes caused by them in the groundwater regimes of the nature reserve wetland area «Lielie Kangari» and in flows of hydrographical network. The research was carried out by applying the hydrogeological mod...

Fibre-reinforcing is an efficient method to improve the mechanical properties of a wide range of materials including soils. A drawback of currently used fibres, given by methods of production, is their uniform cross-section, planar shape and a smooth surface in most cases having an adverse effect on the pull-out capacity of fibres. The proposed paper presents an initial experience with the fabrication of fibres and testing of cohesionless soils improved in this way. The commercially available 3D printer was used a...

Both the Blue Flag as municipal coastal and Green Flag (also Eco-Schools) as educational pro-environmental behaviour development programmes are recognized as the best practice internationally as voluntary and integrative environmental governance instruments. Both are the main objects of this comparative research-and-development study, based on case study research nationally and of best municipal practices, altogether being oriented towards necessity of municipal environmental governance further encouragement in La...

A computer hydrogeomechanical 3D model of a fragment of a soil tailing dam has been developed. The model allows investigating both geo mechanical and filtration processes and also their collateral influence on a condition of soils of the bulk protecting dam and the alluvial beach of the tailing. The following options of development of a hydrogeomechanical condition of a soil dam have been considered: an initial state at the current operation parameters, increase in level of water-saturated mining deposits and the ...

Nearly 20 years have passed since the European Community implemented the European Directives on water management. Its main directions are the achievement of good water quality and the implementation of water management principles. In Georgia, this process has been underway already for 3 years. The country's territory is divided into 6 basin areas. One of them is the Rioni River basin, whose area is 13,000 km2 with up to 700 rivers. In addition, there are reservoirs and a system of irrigation canals. In the downstr...

The article presents results of the studies conducted by the authors for determining the influence of the structure succession on the volume fraction of martensite and ferrite microhardness in a dual-phase steel with low manganese content. For the research in discussion, an alloy with 0.094% C and 0.53% Mn (Si, Cr, Ni, Mo, Al, Cu, P, and S below 0.1%) was used. This alloy was subjected to several cycles of heat treatments (consisting of full annealing, normalizing, subcritical annealing, full quenching, intercriti...

The article analyses geological, climatic, hydrological conditions of formation of the unique thermal regime of the nonfreezing river Ilet and its right tributary Yushoot, located mainly on the territory of the national park Mary Chodra of the republic of Mary El, RF. For a number of years the hydrological character of these rivers, their water and speed rate have been researched, with special attention paid to numerous underground sources of water, their chemical composition and temperature. The flow rate of the ...

The Russian Federation has the largest Arctic coastline and the highest level of population among the other Arctic nations. The Arctic region of the Russian Federation occupies the territory of more than 3 million square kilometers. It is the Mother land of more than 2 million people. The Arctic zone is a unique geographical, climatic and ecological region. It is considered to be a special object of the state administration. The importance of the sustainable development in the Arctic region is determined by the na...

The lack of field studies outcome on ancient wineries and land plots under vineyards in the Kerch Peninsula puts on agenda a higher demand for new data, which is essential for understanding viticulture development of the European Bosporus throughout 4th c. BC ? 3rd ?. AD. The geoarchaeological approach, with the involvement of the natural sciences resources (pedology, geochemistry, palaeobotany), was used to study the soil within the archaeological complex (10 km west of Pantikapaion (modern Kerch)) dated 4th ? 3r...

At national level, a series of technical regulations harmonized with European directives and norms are adopted, which present essential occupational safety and health requirements applicable to the field of explosives for civil use in various specific activities in which their use is necessary. Concerns in the field addressed in the paper, are also registered at the level of the European and international community, respectively, because a good knowledge of the concepts and the practical experience regarding the d...

The goal of the research is to identify the most significant groups of environmental risks for large cities with heritage sites. Along with relatively rare events threatening heritage sites such as karst, floods and landslides, a group of risks associated with fast-paced processes has been identified, with immediate hazardous effects. These are the risk of hypothermia and frostbite, the risk of heat stress, the risk of immediate toxicological effects caused by heavy traffic, the risk of traffic noise and the risk ...

Assessment of soil erosion risk has a great importance for management of land use, allowing decision factors from administration, agriculture management etc. to choose and recommend properly land use according to the sustainable development strategies. This study aims to assess the soil erosion rate in a region with small catchments (Icusesti, Glodeni, Rapa?), located in the west of the Central Moldavian Plateau, a region whose geomorphological characteristics have been shaped under the influence of monoclinal geo...

Majority of world inhabitants are living in cities as well as many inhabitants in Latvia choose to move to cities to look for wellfare. Living in a city with a high density of buildings, cars, and factories, the risk of air pollution increases. Air pollution from the transport, industry, and energy sectors affect the health of the urban population. In cities, air is often contaminated with dust containing various chemical elements, including heavy metals, which, even in low concentrations, can be hazardous to huma...

Nowadays, steel constructions and their elements are used for their properties. One of their advantages is, for example, their low weight in comparison with their load capacity. Also, quick assembly is one of their advantages. On the other hand, there are disadvantages which are associated with changes of properties under thermal stress. There are no significant changes up to a temperature of 350°C, but steel loses their load capacity between 500-700 °C [1], [2]. Because of that, in many cases these constructions ...

Concrete represents a traditional building material that is commonly applied due to its unique properties, like relatively high compressive strength and long-term durability. Such properties are gained because of its composition consisting of aggregate and cement. The usage of Portland cement, a worldwide available binder with annual production exceeding 4.6 billion tons, brings several environmental loads. One of them is releasing of an important amount of greenhouse gases into the atmosphere. Another environment...

Dust emissions from industrial enterprises are often treated as total suspended particles (TSP); and they also quite often contain a wide range of chemical components. Among these components rather hazardous admixtures can be found, such as heavy metals, benzpyrene, polycyclic aromatic hydrocarbons, etc. Structure of emissions in terms of admixtures contained in them is determined by raw materials applied at a specific production, production technologies, structure of an end product, etc. Being suspended, chemical...

Since 2003, the Complex Expedition to study the historical waterways of Russia headed by S.I. Vavilov Institute for the History of Science and Technology of the Russian Academy of Sciences in collaboration with the staff of the Faculty of Geography of Lomonosov Moscow State University performed integrated geoecological exploration of the historical waterways of the Russian Plain. The following sites were explored: the Mariinskaya and Severo-Dvinskaya water systems, Ladoga and Onega canals, the lake-canal system of...