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The data from three solar thermal collector systems installed in dormitories of the University of Latvia in Riga are analysed in detail to obtain parameters that characterise the operation of such systems in real operation conditions in Riga, Latvia. All the systems were installed in 2019-2020 and the data for one full year is available for the study. The area and the power output for the observed solar thermal collectors are similar-63 m2 with 51 kW for each. The differences exist only in the orientation of the c...

The research, which is carried out in cooperation with the Technical University of Liberec, the Klokner Institute of the Czech Technical University in Prague and the company Cervenka Consulting s.r.o., deals with the use of 3D printing of cement composites in architecture and construction. The research develops original equipment for 3D printing of mixtures with cement-based binders, including the original design of printing mixtures and original software for printing data processing and machine control. The ambit...

Three photovoltaic (PV) systems with the identical solar panels, the same charge controllers, and similar loads, but with different used battery types: AGM deep-cycle, LiFePO4 and lead-carbon were installed in Riga, Latvia for a long-term monitoring and analysis of the operation efficiency and potential energy losses in batteries under real operation conditions. Results of one full year of monitoring are analysed in this paper resulting quantitative indicators during different seasons. During the wintertime with l...

Traditional building materials based on primary natural resources can be used for green housing concepts with energy eco-efficiency and the health of the living space, representing a special group of innovative materials for the construction industry. They are developed by using and improving the local, traditional technologies and concepts applied on basic, natural raw materials (clay and sand, wood, straw, wool, etc.), for the general purpose of creating the living space in a sustainable, environmentally friendl...

Asphalt mixtures are the most commonly used material in road construction. It is necessary to know the properties of the mixtures and their constituents, as well as the changes in properties that occur during their service life. The demands on road durability are constantly increasing. The main problem with asphalt mixtures is degradation. Due to the effects during asphalt pavement production and service, there is a gradual degradation of properties. One of the degradation factors is the impact of traffic, climate...

In order to protect the structural steel sheet from the impact of the blast wave, the steel sheet was covered with a composite material consisting of aramid fabrics with a surface density of 200 g/m2 (3 layers) and 350 g/m2 (3 layers). The total thickness of these layers was 2.4 mm. Turkish produced BRE 450 polyester resin was used to connect the layers. The composite was coated on top with the same resin filled with crumb rubber 1.5 mm in size. The thickness of this coating is 2.2 mm. The protective agent thus ob...

In recent years, natural wastewater treatment wetland plants have been gaining more attention from researchers and the public due to their low operating costs and efficient way of treating wastewater. Treatment wetland plants with pulse-fed vertical flow filters are one of the most efficient treatment technologies. For optimum operation, intermittent loading of wastewater onto the filter surface is necessary, for which various types of automatic siphons can be used in addition to pumps. This kind of automatic siph...

The global development of society requires constant updating of the objectives that education pursues and how they are achieved. Science education is an area undergoing advanced transformation, both at the level of objectives and methodologies, with a strong social, economic, and knowledge impact. Research-based education is a well-established term, especially in the higher education system. More studies and key policy documents argue that education must be based on cutting-edge research. Essential in this equatio...

The Eastern pasqueflower (Pulsatilla patens (L.) Mill.) is considered as an endangered species in all European countries where it is found, including Latvia. An important factor for the survival of P. patens - a species with low competitiveness is not only the conditions suitable for germination and further growth, but also the indicators of seed viability. This is particularly important as there is no persistent soil seed bank for this species. Only limited data is available on the factors affecting seed viabilit...

Agricultural activities account for about a third of greenhouse gas (GHG) emissions. Most of the GHG in the atmosphere are carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O). The aim of this study is to measure N2O isotopes in two differently managed agricultural soils. One soil is with organic farming and the other with conventional. Samples were collected in 32 experimental plots as well as a control plot. The samples are thus weighed in 3 l buckets, each 1.8 kg in total. Two samples were made from each...

The transition to mining benches with transverse panels from top to bottom within the boundaries of steeply inclined layers does not allow transforming the results of mininggeometric analysis sequentially for each individual stage of mining into a calendar schedule of mining operations. Therefore, a model is offered for converting the results of mining-geometric analysis into a calendar schedule of mining operations with sequential mining of benches from top to bottom using phased volumes of overburden rocks and o...

The mechanism for the selective adsorption of zirconium ions in a highly acidic medium by sodium-modified titanium dioxide was proposed. The mechanism of adsorption of zirconium ions in an acidic medium by this adsorbent is similar to the mechanism of adsorption of strontium ions in a neutral medium. The selectivity of Na-TiO2 is due to the positively charged surface of the adsorbent in the highly acidic medium.

Diary production is steadily increasing worldwide, as evidenced by a 1.6% increase in milk production. Cattle headcount in Europe amounts to 75.6 mln, with Poland heaving more than 10% of the EU population. Such a significant production is yielding massive waste and animal by products, mainly cow manure. Storage and utilization of these byproducts may result in unwanted emissions of greenhouse gasses such as methane, carbon dioxide, and other potentially dangerous compounds like ammonia. Proper manure management a...

Flash floods are defined as rapidly developing extreme events caused by heavy or excessive amounts of rainfall. Flash floods usually occur over a relatively small area within six hours or less of the extreme event with quite a rapid streamflow rise and fall. Increased occurrence of flash flood events is expected due to climate change and increase in extreme precipitation events [1]. Flash flood forecasting is still a challenge for hydrologists and water professionals due to the complex nature of the event itself. ...

The purpose of the paper is to clarify the formation mechanism of the devastating flood in the town of Svilengrad, in the Republic of Bulgaria, in June 2012. The systemic approach is used to analyze flood formation mechanisms and improve under-standing of the complex interactions between the factors determining the formation and manifestation of floods. The spatial analysis method takes a central place in the examination of the flood formation mechanisms, using GIS as a tool for analysis. Hydraulic model for the 9...

Floods are one of the deadliest natural disasters in the world. According to the World Meteorological Organization (WMO), this is a consequence of the increasing frequency of heavy precipitation, changes in upstream land use, and a continuously increasing concentration of population and assets in flood-prone areas [1]. For this reason, flood prevention, and protection are a growing priority these days. Flood hazard mapping is a state-of-the-art tool for decision-makers and stakeholders when it comes to flood prote...

Contemporary urban meadows as an alternative to amenity mown grass in public green spaces are the solution for biodiversity growth and human wellbeing. In the publication, we present the results of research monitoring the development of flower meadow growth in the urban environment. We focus on the analysis of visual and other properties of herbs, on the basis of which we evaluate the visual and other properties of the flower meadow stand. The result is an evaluation of the suitability of flower meadows in terms o...

According to ANSYS - developer of the Multiphysics platform for computer simulations - the FSI (Fluid-Structure Interaction) model can be used in all cases where a fluid encounters a solid structure, for example, wind gusts rotating a turbine, air washing the surface of a moving car etc. This method finds applications especially in the aeronautical and automotive industries, but also in medical research, such computer simulations track the influences of blood pressure and blood flow velocity in the veins. This pap...

The food spectrum of three fish species from the Mugilidae family in different age groups was studied. The samples were collected in 2019 - 2021 from the river estuaries and the coastal brackish lakes at the Bulgarian Black Sea coast. The research aims to establish the food spectrum of mullets and thus make a connection between food components. The results show that the predominant groups in the stomachs of the three mullet species are detritus, zoobenthos (Rissoa sp. And Trochammina inflate - 64.28%) and macrophy...

Forests rank at the top of the natural assets of Romania, both because of their rich biodiversity, and their livelihood-sustaining role. In the ex-socialist countries that entered the tumultuous early-democratic era and faced many socio-economic adjustments, the monitoring of this valuable biome becomes critical for its sustainable management. This study aims to examine 20 years (2001-2020) of forest canopy loss in the Moldavian counties in Romania, using the spatial dataset provided by the GLAD laboratory and the...

The decarbonization strategies for the built environment that policy-makers face today from the EU mandate risk being made with incomplete or insufficient information. The consequence of this could be ineffective choices, thus slowing down the ongoing ecological transition, or their high cost, whether borne by the state or citizens. The progressive and unstoppable digitization of the built environment offers information collection and previously unthinkable management opportunities. The construction sector, tradit...

The current information age has led, globally, to an exponential increase regarding the availability and the use of the information, both structured and unstructured, a phenomenon known as Big Data. The term Big Data refers not only to the massive volume and variety of data itself, but also to the set of technologies that surround it, in order to collect, store, retrieve, manage, process and analyze data in order to solve complex problems in society, respectively for increasing the quality of life in all its aspec...

We investigated the changes in element content and distribution in peat profile in a study aimed to monitor the geochemical changes accruing in the process of peat accumulation. Changes in the chemical composition of peat ash and underlying sediments have been studied in the central part of the Ubinskoye bog in the foreststeppe zone of Western Siberia. Two parallel peat cores were sampled to a depth of 310 cm. The upper peat layers are characterized by oxidative environment and increased concentrations of elements...

Several geochemical analyses (bulk parameters, particle size, loss on ignition, major, minor and trace elements) were performed on 51 recent sediment samples collected in May 2022 from Rosulet, Rosu and Puiu lakes which are located in the fluvio-marine delta plain of the Danube Delta, Romania. The aim of this study was to decipher the potential origin of anthropogenic and/or natural sources, weathering, sedimentary processes and the local geochemical fingerprint on the distribution of specific chemical elements in...

The article presents the current state and views of the author in connection with the creation of a Geoinformation system for the territory of Bulgaria within the meaning of the Geodesy and Cartography Act. The provisions of this law on this issue are from its entry into force, i.e. since 2006 and so far, there is no officially published information on actions in this direction, except for the creation and maintenance of Web applications with information on materials and data from the Bulgarian Geocartfond and inf...

This paper covers the activities of creating a database for the study of modern crustal movements in the region of Sofia and Southwestern Bulgaria, including data from GNSS measurements of the geodynamic network and the results of their processing and analysis, data from permanent stations and archive data from Synthetic-aperture radar, processing and obtaining interferometric images. The local archive of GNSS measurement includes: manual sketches of the location of the points; log sheets of the measurement with i...

BIM (Building Information Modeling) allows the use of a virtual building model throughout the whole life cycle of the building. It is a parametric object-oriented 3D data model of a building, which contains information about structures, elements, and their parameters. The combination of the BIM model with detailed data on the as-built geometry of the building enables an effective geometry check of the structural elements, which leads to in-time intervention in the building process if needed. The requirement of eff...

Geopark is a region that has a complex special protected status, on the territory of which the geological history of the Earth, the formation of local landscapes, expressive geological formations, and layers of fossil fauna are clearly revealed. A geopark is not only a geological heritage, but also habitats for biological species, interconnected ecosystems, it is a cultural and historical heritage. Geopark is a favorable environment for the development of ecotourism and related business. UNESCO Global Geoparks are...

The Alto do Sobrido and Ribeiro da Serra Mines, are two antimony-gold mines located in Gondomar, Portugal, and are part of the Durico-Beirao Mining District (DBMD). In this work, we use four geophysical methods, such as gravity, radiometry, magnetic and electromagnetic, to improve the knowledge about these mineralizations and the lithologies and structures associated with them. These four methods allowed us to study these mineralizations through different physical properties. The gravimetric method allowed us to a...

Romula, the most important urban settlement of Dacia Inferior (Dacia Malvensis) province of the Roman empire during the 2nd and 3rd centuries A.D., was located in the present-day Resca village-Dobrosloveni commune, Olt County, Romania. Most of the Roman town remains are underneath Resca village premises, the areas suitable for archaeological or geophysical research being limited. This paper presents an integrated geophysical study carried out in the Central Fort zone of the archaeological site in September 2020, w...

Erosion dominates among the degradation processes of chernozems (black soils) in Ukrainian. It covers 32% of the total area of agricultural land - 14.9 million hectares. The development of erosion processes depends on the combined effect of factors: climatic, geomorphologic, geologic (including the characteristics of parent rocks), hydrogeologic and technogenic impact. The purpose of the research is the analysis of natural and technogenic factors of chernozems degradation in Ukraine to develop the principles of pr...

The purpose of this work is to determine and evaluate how the newly built areas, in the municipality of Iasi, in the period 2016-2021, are affected by the Urban Island. The Urban Heat Island (UHI) represents the phenomenon of higher atmospheric and surface temperatures occurring in urban area or metropolitan area than in the surrounding rural zones due to urbanization.The data acquisition stage involved extracting construction data from the unique integrated national system of cadastre and real estate advertising,...

The current research aims to apply cluster analysis using the software ArcGIS in the study of the food industry in Bulgaria for the period 2010 to 2020. The use of clustering methods is necessary to differentiate homogeneous groups of administrative-territorial units of NUTS 3 level on certain indicators to reveal several features and implement specific economic policies and measures for areas of a cluster and others. The grouping of the areas according to the considered indicators was done with the tool Grouping ...

Climate change and environmental degradation pose an existential threat to the EU and the world. The aim of the Green Agreement for Europe is to make Europe climate neutral by 2050, to support the economy through green technologies, to create a sustainable industry and transport and to reduce pollution. Turning climate and environmental challenges into opportunities will make the transformation fair and inclusive. The European Commission is helping EU Member States to design and implement reforms that support ecol...

Waste management is a public service, the provision of which is the responsibility of local authorities. The area of waste management is currently very strongly regulated in the national and European and at the same time monitored by the civil public with a strong context in public election processes. Expenditures on waste management make up a relatively substantial part of municipal expenditures not only in the Czech Republic but also in developed countries, which is why a number of economists are paying attentio...

The inclusion of greenery in spatial planning has an irreplaceable function. Not only do these areas fulfill an aesthetic function in otherwise monotonous areas of villages and towns, but they also significantly affect the quality of life of local citizens. These are primarily areas that provide a space for people to meet in a pleasant green environment and, thus, an opportunity to relax and recharge their batteries as a result of the positive effect of greenery on the human psyche. At the same time, green areas s...

In the last time there is an open dialog among scientists, economists, engineers, politicians, as well as city councils and municipalities, about future plans for urban development by considering green real estate for shaping sustainable cities. Applying the concept of sustainable development concretely means to develop and apply local strategies, not only in technology, and economy, but also in environmental and social fields, by considering sustainability requirements. In this regard it is obvious that mindset c...

The awareness and attitudes of stakeholders are crucial for the development of green roofs and green walls. The aim of this article is to analyze the awareness, opinions and attitude of respondents from Sofia, Bulgaria regarding green roofs and green walls, as well as the willingness to pay (WTP) for these types of green infrastructure. A direct consumer survey was conducted, containing 17 questions regarding sociodemographic characteristics of the respondents, awareness/opinions about green roofs and green walls ...

Higher education institutions play a central role in shaping labor skills and green culture essential in the future low-carbon economy. This paper examines the impact of green education policies in the higher education sector on the business cycle and compares them to standard incentives to encourage green production at the firm level. For our purpose, we set up a Dynamic Stochastic General Equilibrium model extended to account for the endogenous selection of green and traditional human capital and heterogeneous h...

Environmental friendliness, energy efficiency and sustainability are very important issues in all aspects of human lives. This is particularly true for shipping, including all its modes like long-distance, short-sea and inland shipping, where environmental regulations have become very strict in the last decade. On the one hand, fishing vessels are slightly out of these regulations, but on the other hand greening the fishing fleets is highly promoted by the European Union funding bodies as well as by the local auth...

At the Azgir nuclear test site in Western Kazakhstan 17 nuclear explosions were carried out at a depth of 165 to 1500 m, as well as ground explosions. Nine underground cavities with a total volume of about 1.2 million m3 with extremely high residual radioactivity were formed in the thickness of the rock salt layers. Five of the nine cavities are filled with groundwater and strontium, cesium and plutonium radionuclides are leaking into the environment, and radionuclides spread through food chains. A medical examina...

Initially developed as one of the most successful methods for stimulating hydrocarbon production, hydraulic fracturing (HF) has gradually found its application in related fields, such as underground mining. At the same time, the importance of controlling the crack propagation path increases, since the design of in-mine hydraulic fracturing is a complex technological task due to the influence of mine workings and other inseam boreholes. When performing HF for the purpose of degassing a coal-bearing massif, there is...

The study presents a developed instrumental and methodological complex designed to monitor changes in the state and development of dangerous processes in a natural and technogenic system, including the structural integrity of building structures and geodynamic processes in the soil rocks of their placement sites, including the activation of previously passive faults. The complex includes three orthogonal molecular-electronic linear displacement sensors and three orthogonal torsional vibration sensors which can sel...

The electrification process of the materials and technical equipment-s, especially the external parts of them, frequently occur during their use, being sometimes an intrinsic process, such as for example flowing of a flammable liquid through a pipe. The electrification process of materials and technical equipment-s is responsible for generating, through specific mechanisms, significant quantities of electrostatic charges. The presence of electrostatic charges on materials and technical equipment-s, used in areas w...

Magnesium oxychloride cement (MOC) is a non-hydraulic binder produced in a more eco-efficient way than Portland cement and due to its favorable properties represents its promising alternative in the production of construction materials for specific applications. The specific advantage of MOC is the fact that it can accommodate organic as well as inorganic substances in the form of fillers, aggregates, additives, reinforcement, etc. which enables enriching properties and performance of the final composite material....

The Research Institute for Brown Coal j. s. c. (VUHU) has been involved in the research project of the EU Research Fund of Coal and Steel - The impact of extreme weather events on mining operations for four years. The project is focused on assessing the impact of climate change on mining activities in major European coal basins. Other participants are scientific teams from Poland, Great Britain, Spain, Germany and Greece. This is the last year of the project solving, so this paper summarizes the results of the sol...

Awareness of the importance of sustainable agriculture has increased in recent decades. One of the reasons for this is the widespread use of synthetic pesticides and their possible secondary negative effects on valuable carnivores and biodiversity. Therefore, the need for biological and environmentally friendly alternatives to pest control has become relevant. This relevance is also reinforced by the European Union's Green Deal agenda and its underlying strategy - Farm to Fork, which aim to mitigate climate change...

The first oil discovery from Romanian Black Sea area was in 1987, relatively late compared with the first successful Romanian onshore well, more than 100 years earlier. Starting from that moment and continuing till recent years, several discoveries were done; some are already put into production and some others are still in the exploration phase. In order to extract as much oil as possible and also to define new hydrocarbon reservoirs, it is mandatory to have a proper understanding of the petroleum systems from th...

As the world adopts the technological era, the adverse effects of climate change have been experienced by the increasing population, which has led to a rise in energy demand. Heavy industries depend on dirty fossil fuels that release GHG emissions into the atmosphere. This paper aims to review the integration of a nuclear-renewable hybrid energy system (NRHES) to produce green hydrogen in decarbonizing hard-to-abate industries in the ASEAN region. In this study, the two main hydrogen production methods were identi...

Floods are the most frequent and widespread natural disasters worldwide (WMO, 2013). In 2006 for instance, exceptionally high river levels caused loss of lives and considerable economic losses in Serbia, Bulgaria and Romania. Thus risk prevention strategies were reconsidered and the need for common solutions for the Danubian countries was outlined. Non-structural measures to mitigate flood risk as is the improvement of forecasting capabilities on a basin-wide scale are known to be highly effective. The DAREFFORT p...