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The cycle of nitrogen is an essential, integral process in nature. Since amino acids form an important part of life-building and maintenance, nitrogen and its chemical compounds are an integral nutrient and ingredient for all living organisms. Understanding the processes in soil is essential because it helps both to ensure agricultural productivity, to control various, soil-based, unwanted pests and diseases, and, crucially, to limit climate change-related factors directly related to soil. The nitrogen cycle resea...

Among the global threats facing humanity in the 21 century, the danger of climate change on Earth occupies a prominent place. Global climate change caused by anthropogenic factors can lead to natural disasters and, as a result, have a negative impact on human life and health. Given the importance of this problem, international organizations, governments, politicians at all levels, NGOs and society as a whole are involved in solving it. The purpose of the study is to determine the forms, activities and results of t...

Many operations with flammable liquids produce flammable atmospheres by evaporation of the liquid being handled. In some circumstances, the flammable atmosphere is not due to the liquid being handled but due to residues of volatile liquid or vapor from earlier operations with the same equipment as is often the case with diesel fuel handling. This paper highlights some aspects regarding the danger of fires and explosions in the transport, storage and distribution of diesel fuel starting from the investigation of th...

The aim of the study is to construct a priori constraints imposed on the model in the course of solving the inverse seismic problem. The object of the simulation is the structure of the upper part of the Khibiny massif — the largest alkaline massif located on the territory of the Kola Peninsula. The research is based on shallow-depth seismic tomographic modeling, which includes multi-stage work. Petrophysical materials concerning the main classes of rocks of the surface of the Khibiny massif and its framing were p...

Asellus aquaticus Linnaeus, 1758 is the widespread and common Palearctic freshwater isopod, feeding on detritus. This crustacean, probably, has its ancient evolutionary origins around Siberia and has spread from there to Western Europe and North America. Commonly associated with a temperate climate, it has been recorded as far south as the Mediterranean, and as far north as Scandinavia. The species is primarily associated with the b-mesosaprobic waters of the palearctic realm i.e., high concentrations of dissolved...

Gamma-ray spectrometry is one of the most important and informative methods for various geological surveys. In field geophysics on the surface or in the air, the method is used for regional geological zoning, mapping of bedrock outcrops, etc. The most promising direction of geological surveys today is research with the use of UAVs. Conducting gamma-ray spectrometry using UAVs is complicated by the need to accumulate a large number of measurements to construct the correct gamma-ray spectrum. From this point of view...

Natural processes and human influences can cause several environmental issues upon urban and rural aquatic systems, especially in deltaic environs. This study was aimed to assess the vertical variation in the physical-chemical and lithological characteristics of core sediments. 14 undisturbed short sediment cores were collected from soft lacustrine sediments in various shallow lakes situated in the Matita-Merhei interdistributary depression, Danube Delta, Romania. Sediment samples were measured for temperature, pH...

The European Plate Observing System (EPOS), is a multidisciplinary, distributed research infrastructure that facilitates the integrated use of data, data products, and facilities from the solid Earth science community in Europe. The EPOS pan-European dimension is corroborated by 25 countries, 5 international organizations, 149 national research organizations and 256 research infrastructures involved in the data and service provision. The legal and governance framework designed during the Preparatory Phase and deve...

In north-eastern Bulgaria, within Moesian Platform, one commercial oil and gas field and several smaller semi-commercial gas accumulations, located onshore, have been established. In continuation of this tectonic unit in Western Black Sea Basin there are several more accumulations of hydrocarbons. The object of this research is NE part of Moesian platform in Bulgaria onshore and offshore. The purpose of the present study is clarifying the source rock potential of the sediments by burial history and thermal maturit...

The scientific interest of evaluating the thermal regime of various areas has come to the fore with a more complete understanding that all major processes inside the Earth are related to thermal events and that all physical properties of rocks, as a basis for observed geophysical phenomena, are more or less dependent on temperature. The characterization of the thermal regime is followed by the basic elements: temperature and geothermal gradient, thermal conductivity and geothermal flow. The quantitative study of g...

The article deals with the issues of domestic tourism. It is proposed to use the ideas of synergetics to assess the development opportunities of the tourism business in three regions of the Arctic zone of the Russian Federation, taking into account their physical, geographical and economic position. Tourism resources, types of tourism and accommodation facilities were discussed, as well as types of recreational activities in these areas. It is shown that the tourism business is an interdisciplinary science, as it ...

The priorities in the policy of the energy sector of the Republic of Bulgaria after 1989 are in harmony with the requirements of the European directives and market mechanisms. An important aspect is the policy to promote the use of renewable energy sources (RES), which aims to achieve sustainable energy development and improve environmental performance. It is also related to the implementation of the commitments made by the Republic of Bulgaria regarding the United Nations Framework Convention on Climate Change (1...

The spectral characteristics of the ULF waves (1mHz -1Hz) provide useful information about the conditions in the solar wind and in the magnetosphere. A series of geomagnetic field variations data are collected by the tri-axial search-coil instrument and acquisition system located at Panagjuriste, Geomagnetic Observatory (PAG), Bulgaria and other series of data are collected from two different instruments located at Conrad Observatory (WIC), Austria and Ebro Observatory (EBR), Spain, which operate within INTERMAGNE...

The global problems of the functioning of the economy, industry and energy are among the most important areas of scientific interest and knowledge. Renewable energy sources play a significant role in the global energy sector. The potential applications of these sources are almost limitless, which makes it possible to expand the list of energy resources used. With the economic growth of the forest, woodworking and pulp and paper industries, waste from the wood used in processing-bark and branches, wood chips, scrap...

The purpose of this study is a spatial-dynamic and structural hygienic assessment of the impact of the activities of thermal power facilities on the quality of atmospheric air and the formation of potential risks of harm to the health of the population in a large industrial center with a population of more than 350 thousand people and a total area of more than 500 square kilometers. At present, heat and power facilities belong to the main industries and form significant potential risks of harm to public health in ...

The paper investigates the problem of determining the interinfluence of production and injection wells on a single development target. To solve this problem, we develop a stochastic reservoir model, which is a variant of extended Kalman filter. The model is some simplification of the hydrodynamic model. Its purpose is to estimate interwell permeability through production history. We discuss different variants of the model, which vary basing on availability of certain input data. On the baseline, the model can only...

The wind energy is substantially growing in the last decade, but the biggest challenge remains the prediction of the performances of the wind turbines. The increasing energy demand and climate changes forced us to commit quick decisions and to develop efficient solutions. One of the solutions can be repowering and significant changes in transmission systems to deliver it through the electric grid. Fantanele Cogealac is the largest onshore wind farm in Romania. The wind farm exist since 2012, so in at least 10 year...