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In the last decades the ecotourism become ever so popular in the protected natural areas. This form of tourism is more and more used as a new science which can reflect the new coordinates and trends for the development of the tourism industry on a global scale. In the beginning it was applied only in the natural protected areas, and step by step its area of influence got extended over the other major forms of tourism as well. By the end of the 20th century and beginning of the 21st century the ecotourism is gradua...

Ecotourism is one of the most rapidly developing new forms of the tourism industry which started to gain ground considerably by the end of the 20th century. This is the new trend in promoting a conscious and sustainable form of tourism with regards to the inherited natural environment and which promotes education, protection and preservation of the natural environment, economic growth and social development of the local communities. Thus in this paper we would like to present some of the aspects of the actual stat...

Salmonid fishes have always been the most valuable objects of the fisheries in the Baltic region. The population growth in Baltic region and the demand for fish products have resulted in the overfishing and impoverishment of many fishing areas. Most of wild types of fishes are losing their native spawning areas because of anthropogenic transformation involving hydro-technical construction, eutrophication of water bodies, water pollution and inadequate fishery. Heavy metals are considered as main toxicants in the p...

A research of edible gelatin rainbow holograms is presented. Gelatin is an edible material with optical properties: it is transparent in the visible region of the spectrum and has refractive index close to refractive index of optical polymers. Gelatin is capable to transfer diffraction relief and save it for a long time. Gelatin holograms were prepared by nanoimprinting method from gelatin aqua solutions with different concentrations (1 part of gelatin per 5, 10, 15, 20, 25 parts of water). The samples were made o...

For several years already, Latvian companies have been participating in the evaluation of Sustainability Index where the environment is an important factor. Sustainability Index is a tool aiming to help companies in establishing the level of sustainability and responsibility. In addition, it supports and praises the enterprises that help to strengthen the Latvian economy, environment, and society in the long term. One of the elements of Corporate Social Responsibility (CSR) is the impact of the organization on soc...

A global climate change caused by anthropogenic emission of greenhouse gases (CO2, CH4, N2O) is one of the most important environmental problems in the latest human history. Nitrous oxide (N2O) emissions from agriculture reach approximately 70% of annual global N2O emissions and approximately 75% of all N2O emissions in Slovakia. Cultivated soils are the main source of N2O in terrestrial ecosystems and therefore its mitigation from agriculture is urgently required. The studies on the effect of biochar application ...

The current demand of some specific metals (alloys) in the HiTech industry has pushed researchers to increase the number of investigations to improve the quality of products on the market. Generally, coltan is a byproduct of tin metallurgy and is collected in the slag. The formation of phases in the slag needs to be investigated in order to optimize the collection of coltan in specific phases by trying different ratios in fluxes. Also, cassiterite is associated with iron ores and during smelting the iron get reduc...

Catch crops have the potential to positively affect soil and environmental quality, including the reduction of soil erosion by water. As growing of catch crops require additional costs, farmers should be aware of the benefits that catch crops can provide. The objective of the paper is to evaluate the potential effect of catch crops with respect to reduction of soil erosion in transboundary Lielupe and Venta river basin districts (RBDs) shared by Latvia and Lithuania. Both RBDs are characterized by intensive crop f...

In-situ combustion is considered as one of the most effective ways to enhance recovery of heavy crude oils and bitumens. The oxygen from injected air reacts with the heavy components of the crude oil, forming a hot zone in which the cracking and oxidation of the heavy fractions occurs. It is noted that the combustion process essentially depends on the pressure and the nature of the crude oil. Thus detailed study on the effect of the gas phase composition on the processes of crude oil oxidation seems to be relevant...

An electrolyte for chromium based nano-composite electrolytic coatings (nano-CE?) obtaining has been developed. Nano-CEC was applied on steel of the St 3 brand with constant exposure to ultrasound, electrolyte temperature 50?60°?, current density 7kA/m2 for 1 and 2 hours from two variants of chromium-plating electrolytes, differing in the fact that one electrolyte contained strontium sulfate, in the other ? without it. Quantitative assessment of the corrosion resistance of nano - CEC deposited on steel St.3, was e...

Vegetables are considered a rich source of antioxidants (flavonoids, carotenoids, vitamins), which are frequently added to stop the process of oxidation in processed food systems. The solid waste generated in food industry was considered as a low cost raw material for the extraction of natural antioxidants. The effect of drying techniques (ambient-drying and oven-drying) on the total phenolic contents and antioxidant activity of selected vegetables byproducts (garlic (Allium sativum L.), tomato (Lycopersicon escul...

One of the most widespread acidophilic fruit crops in Latvia is highbush blueberry (Vaccinium corymbosum L.). The first commercial plantings were established at the beginning of 2000th, and in 2016 the blueberry orchards exceeded 290 ha. In general, blueberry is a highly specialized crop that has definite soil agrochemical prerequisites. In Latvia, highbush blueberries are cultivated in extracted raised bogs on peat soil, as well as on mineral soils with high organic matter content. Unlike most fruits, blueberries...

The crack propagation and autogenous shrinkage pose a significant weakness for concrete structures. On this account, the utilization of smart materials can be viewed as a promising step to overbridge the common issues. Namely, the application of superabsorbent polymers (SAPs) can improve the autogenous shrinkage and crack sealing thanks to its great swelling capability. However, SAP particles used as water retaining admixtures have a substantial influence on the rheological properties due to fast water removal fro...

The presented work deals with the effect of maize and legume planting density within mixed cropping system (MC) on selected indicators of soil quality: (1) microbial carbon content (Cmic); (2) total soil carbon (Ctot) content and (3) total soil nitrogen (Ntot) content. To demonstrate potential effect of different plant density within MC, 4-year field experiment was established in 2017 and will continue until 2020. The field experiment consisted of two MC groups with different plant density of maize (75 000 plants/...

Acidophilic microorganisms oxidizing ferrous iron and sulfur are widely used in hydrometallurgy to extract different metals including copper, zinc, nickel, cobalt, and uranium from sulfide ores. The activity of microorganisms and screening of microbial strains capable of biooxidation of ferrous iron and sulfur compounds under different conditions, i.e. in the present of different toxicants, which may be present in treated ores, are crucial for the development of biohydrometallurgical technologies. Different factor...

Biohydrometallurgical technologies based on the oxidation of sulfide minerals by acidophilic microorganisms oxidizing ferrous iron and sulfur are widely used for the extraction of non-ferrous and precious metals from sulfide ores and concentrates including gold-bearing refractory concentrates. Microorganisms involved in oxidation of sulfide minerals differ in ability to use sources of carbon for constructive metabolism and capable of both CO2 and organic nutrients assimilation. Their activity depends on availabili...

One of the promising areas of rational use of wood and wood waste is their processing using pyrolysis technology, in which solid biomass can be converted into liquid useful products. Pyrolysis liquid products in the form of raw bio-oils or charcoal suspensions have several advantages over solid ones: high energy density, composition stability during storage, ease of use and transportation. The article investigates the effect of preliminary heat treatment of ground aspen wood on the mass yield of products, obtained...

The development of industry is always accompanied by an increase in the negative impact on nature. A variety of waste generated at the production stage for a long time is stored, accumulated and transformed. This is especially true for organic waste, the amount of which is steadily increasing as the industry develops. In this regard, the issue of their processing is becoming increasingly important. Currently, one of the optimal types of organic mass processing is pyrolysis. However, in most cases, thermochemical p...

Soil contamination with heavy metals is a major national economic and environmental problem, since heavy metals are subject to destruction and are able to be actively involved in the biological circulation and accumulate in vegetation and animal organisms [2]. Therefore, the theoretical and methodological basis of this work was the scientific development of the theoretical and methodological nature of scientists in the field of sugar production and poultry meat production, which revealed issues related to the crea...

Climate-change scenarios all around the world indicate that many areas of the globe will increase in aridity. Plants need a large amount of water and nutrients throughout their life cycle and all aspects of plant development are affected by a reduction in water content in the soil. This reduction in soil moisture leads to changes in the physical environment, which subsequently affect physiological and biochemical processes in plants. Based on sap flow measurements, it is possible to optimize irrigation. For our ex...

Pyrometallurgical processing of arsenic containing polymetallic ores and concentrates poses a problem due to the emission of toxic gases. Hydrometallurgical methods including bioleaching may be used as alternative approach to treat this type of mineral raw material. To perform effective hydrometallurgical processing of mineral raw materials, factors affecting leaching efficiency should be studied. The goal of the present work was to study the effect of sodium chloride on copper bioleaching from arsenic-containing ...

Hyaluronic acid (HA) is rightfully considered as a promising and advanced polymer for development and producing a variety of applications in medicine, biotechnology and tissue engineering. One such trend is electrospun fiber materials obtained from HA solutions. However, HA has absolutely highly resistance to volatile organic solvents (such solvents are strongly encouraged for utilizing in case of electrospinning), that make the obtaining of polymer fibers difficult. Despite this, some authors could elaborate nano...

The use of recycled polyethylene terephthalate (PETr) in new value-added products is problematic because, during reprocessing in the melt, it undergoes a number of chemical, mechanical, thermal and oxidative degradations, which leads to decreased intrinsic viscosity / molecular mass and implicitly to poor mechanical and thermal properties. In the literature, numerous approaches have focused on obtaining polymer blends using PETr in combination with other thermoplastic polymers. Unfortunately, such mixtures are inc...

In the present work, films based on a potato starch/gelatin composition were prepared with a different ratio of components from 100/0 to 0/100 vol.%/vol.% with increment of 10 vol.% and addition of glycerol as plasticizer. The films were obtained with different drying regimes of the film-forming solutions at 25, 35, 45 and 50 °C for 24 h. For the obtained films the influence of their composition and the drying regime of the film-forming solution on the mechanical properties at puncturing, wettability and water sor...

Heavy hydrocarbon feedstocks including heavy and extra-heavy oils produced from oilsands reservoirs have a high viscosity, which cause a big challenge to their productions and pipeline transportations. Techniques to reduce the viscosity at low incremental production cost are desirable. Thermal decompositions of these resources-derived bitumen at temperatures of 250 °C was explored as a prospect strategy for viscosity reduction. In this work, thermal visbreaking experiments were carried out in a stainless-steel 350...

In situ combustion (ISC) method is considered as a relatively inexpensive and effective method for enhanced oil recovery (EOR). It can achieve a very high oil recovery factor due to a significant increase of pressure and temperature during the combustion process of crude oil. Over the last ten years, high pressure differential scanning calorimetry (HP-DSC) has been widely used for understanding the oxidation process of heavy oil. In this paper, HP-DSC experiments were carried out to investigate the alteration of c...

The biology and ecology of Daphnia (Crustacea: Cladocera) is dependent on a number of biotic and abiotic factors. One of the ways Daphnia adapts to changes in environmental conditions is their swimming behavior. In this study, we assessed the effect of temperature and light intensity on the swimming activity of Daphnia magna in laboratory experiments using computerized video analysis in real time by the hardware-software system ?TrackTox?. In experiments we simulated different levels of temperature (14.5 ± 0.2, 20...

The article deals with the effective reduction of drinking water loss in its distribution in the territory of the model municipality in the Czech Republic. Loss reduction is a long-term process that is one of the cornerstones of the strategy of each operator or owner of the water supply system. Losses of water in water network characterize not only the construction-technical condition of the distribution system in a given agglomeration, but also one of the business cards of the operator or owner of the distributio...

Nowadays, there is a gradual decline in oil production from conventional reservoirs, and it leads to introduction of unconventional hydrocarbon sources into the development. Shale oil production is one of the focus areas of potential unconventional hydrocarbon reserves development. Besides ultralow permeability, low porosity, and high reservoir temperature, its production is complicated due to the lack of geological information, complex reservoir structure and physical processes occurring during multiphase fluid f...

The aim of the paper was to determine the level and structure of material expenditures in the selected organic farms. As measures of effectiveness of use of material expenditures, relations of the total value of agricultural production and the agricultural income to material expenditures were assumed. The scope of the study covered the research in thirty certified organic farms located in the south Poland in Malopolskie, Podkarpackie, and Slaskie voivodeships. These farms held certificates of organic farms. Materi...

Oilseed rape (Brassica napus L.), a crop with great economic value, is grown for oil-rich seeds and after soybean is the second most common oil crop. According to literature, oilseed rape has a great demand for sulphur and boron, mainly for synthesis of glucosinolates and sulphur aminoacids. The present research was developed during agricultural year 2017-2018 in Ialomita County using Jumper rapeseed hybrid. The objective of the study was to evaluate the influence of mineral fertilization combined with boron and s...

Thermal methods have attracted a significant attention for the extraction of high-viscosity oil and natural bitumen. One of the promising methods for enhanced oil recovery (EOR) is in-situ combustion (ISC). In the reservoir, the combustion process occurred in the porous media of rock. As we all know that rock contains different minerals that may influence the crude oil combustion characteristics when air is injected into the heavy oil reservoir. Thus, it is important to determine the influence of various types of ...

Manure and manure-based composts may contain antibiotics and antibiotic?resistant genes (ARGs). Application of composts on agricultural soils can be a potential risk of the spread of antibiotic resistance. The effect of compost containing ARGs was assessed in a 35?day pot experiment on the following soil characteristics: the level of respiratory activity and microbial biomass, the bacteria?fungi ratio, the content of tetracycline?resistant genes tet(M) and tet(X), and the content of OmpF gene encoding horizontal t...

The research studied the effects of solubility, disperse features (Z average diameter dav, and charge (?-potential) of the particles of heavy-metal slightly soluble compounds exemplified by aluminum (III), zinc (II) and plumbum (II) hydrates related to efficiency of their removal from aqueous solutions in the composition of 2- and 3-component systems by means of electroflotation and filtration within a wide pH-range (5 ? 12). The metals in question demonstrate various pH-values of hydrates formation and solution. ...

The study presented in this paper is related to the extraction of humic lignite substances and the separation of fulvic acids in order to introduce them into a fertilizing matrix and to evaluate the effect on tomato culture. Fulvic acids have biostimulatory effect on agricultural crops and have significant uses in agriculture. For the characterization of fulvic acids (FA), the total acidity and content of carboxylic groups were determined. The separate fulvic acids were introduced into a matrix containing nutrient...

Nowadays, many torque wrenches can be found on our market, employing different principles, both mechanical and electronic, with various values and torque ranges. However, among these available torque values, there are significant lacks, concerning mainly the torque values in the tenths and units of cNm, which are required for many applications in the field of fine mechanics, optics and electronics. The article deals mainly with the effects on the accuracy and repeatability of torque wrenches, using an example of a...

Recently, the woodworking industry is increasingly paying attention to the effective use of wood in the production of consumer goods. The key point in resolving this issue was and remains the careful and economical use of harvested wood. Logging volumes in Russia, according to analysts of the timber industry complex, have declined everywhere by 2017, while in the North-West region they have reached 3%. One of the possible and promising areas for the effective use of wood is gluing. Glued wood is widely used in var...

The North Caucasus economic region is an area where all Russian agricultural crops are cultivated, but at the same time it is one of the most difficult regions in terms of soil and climatic conditions: from semi-desert areas to mountainous ones. The district is an important food base of Russia, a supplier of grain, sunflower, sugar beet, vegetables and fruits, grapes and livestock products. At the same time in the region there are big problems of effective and rational use of land, which is associated with both so...

Today, waste of electrical and electronic equipment is a big problem because it contains heavy metals such as copper, cadmium or nickel that cause neurological diseases. In addition, such waste also contains precious metals such as gold and silver, which makes this material really attractive for recovery. One of the fastest-generated groups of electrical and electronic waste is mobile phones. In 2008, the global sale of smartphones reached the level of 140 million units, while in 2015 it is rapidly growing to the ...

A sustainable remediation of halogenated aromatic hydrocarbons pollution such as chlorobenzenes (CB) based on the use of electro-Fenton as treatment process requires the development of reactor conditions as well as the cost of operations. A combined process coupling an electrochemical and Fenton processes with Pd catalyst in order to degrade CB was investigated with H2O2 production. The electro-Fenton treatment of CB was examined and the processes mechanism was identified for different concentrations of 5-11 mg/L ...

Consumption of energy resources is one of the most important factors of economic growth. Competition for energy resources leads to expansion of range of consumption of renewable and non-renewable energy sources, such as hard-to-recover or shale oil, gas hydrates, biomass, wind, solar, geothermal and other energy. Development of technologies, energy security and environmental sustainability cause inter-fuel competition. However, despite the diversity and substitutability of the types of energy resources, the main f...

The study is the first experience to assess the possibility of obtaining clean garnet material from garnet-mica schist from waste Keivy area of Kola Peninsula using electric pulse disintegration. It is shown that the fraction +0.25-0.5 almandine garnet crystal crushed using electric pulse disintegration material and after it washing upward flow of fluid contains up to 94% clean garnet.

Cement-based composites belong to the most frequently used construction materials in the world which is mainly for their good mechanical properties and durability. However, production of cement exhibits significant impact on environment due to a high amount of consumed energy and CO2 emissions. Therefore, alternative environmental-friendly construction materials with comparable materials properties are currently intensively studied. Geopolymers based on alkali activation of waste precursors exhibit lower impact on...

An area prone to landslide, threatening a small accumulation dam and a near-by landfill, was investigated by means of electrical resistivity. The variation of electrical parameters (electrical resistivity and chargeability factor) of soils and rocks is seldom used as a diagnostic tool in areas prone to mass movements. When the mentioned parameters are acquired using a multielectrode measuring system, the subsurface characterization is highly enhanced, considerably decreasing the number of invasive tests necessary ...

The ability of acidophilic microorganisms to oxidize sulfide minerals is increasingly used in biohydrometallurgical technologies to produce non-ferrous and precious metals from sulfide ores. Strains of Acidithiobacillus ferrooxidans and Sulfobacillus thermotolerans often dominate heap bioleaching processes. Due to their high ability to catalyze redox processes, it has been suggested that they can be used in the technology of microbial fuel cells (MFCs). MFC allows using organic and inorganic waste as a substrate f...

Conveyor belts are used for conveying both loose and lump materials in surface mines. During their transport, especially in the places of pouring these materials, where the material is crushed due to a large impact height, a large amount of dust is generated. This makes problems in the actual operation due to fire or explosion hazards, and also by fouling up the vicinity of conveyor belts and transfer points. The resulting dust also poses a threat to the health of operators. Most of the resulting dust accumulates ...

Presently, energy efficiency (EE) improvement is considered a part of the state environmental policy in Russian Federation, an instrument for modernization of national industry and a tool to enhance its environmental performance. This approach holds much promise regarding ceramics manufacturers, where industrial sites are most energy-intensive and are classified as category I objects in terms of negative environmental impact. Since 2010s Russian practitioners have tended to evaluate energy efficiency and environme...

Heritage historic buildings are often wasteful in terms of energy efficiency. Changing their energy supply, load and consumption is particularly challenging given that heritage needs protection and interventions on the building architecture are limited. From the point of view of the renewable energy sources integration in historical buildings, the aesthetic aspects are very important and due to this reason, modern systems can be ruled out. However, the energy efficiency challenges imposed by today's society can be...

The territory of the Danube Region represents one fifth of the European Union?s total area and is home to more than 100 million inhabitants. The Danube Region is characterized by a divergent group of 11 countries (9 of them are EU member states, 5 are non-EU countries) concerning the process of integration and the preconditions in geographic, economic, cultural and socio-demographic terms. In order to increase growth and strengthen cooperation at a macro-regional level, the European Union established the Danube Re...

The contribution deals with the energy performance of variants of the building with the glazed cladding. Nowadays, glass facades on commercial buildings are a big fashion hit. Correct adjustment of the glazed surfaces helps us to warm the interior in the cold months, but in the summer months, the interior space becomes overheated. These buildings then look truly original, modern and architecturally interesting. The paper offers possibilities of the structural design of facade shielding and compares the results of ...