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Abstrakt

In the southern Spitsbergen area, thermal and mineral waters are primarily associated with subpermafrost deep circulation, being mixed with shallow circulation and glacial waters. Four thermal springs, located in the region of Stormbukta (Sørkappland), were studied and analyzed. In the thermal waters, the main cation is sodium, while the main anions are chloride and bicarbonate. The temperatures of the mineral and thermal waters range from 3.4 to 15.1°C. The pH values are between 7.43 and 8.41. The total dissolved solids (TDS) content of the geothermal waters is in the range of 346–4031 mg/l and the Olsok thermal spring has the highest TDS values. Based on the variation in physicochemical characteristics, two thermal water types were distinguished in the study area. The first type is associated with thermal waters originating from deep circulation waters. The second type is associated with the thermal and mineral waters originating from the mixture of subpermfrost hot brines with glacial waters.
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The aim of the study was to determine species structure of aquatic bugs in four anthro-pogenic water reservoirs. Heteroptera structure observed in studied reservoirs was clearly differen-tiated, which refers to age of the ponds. Newly created water reservoirs become quickly colonized mainly by pioneering species Corixinae, which led to formation of taxonomic group population of density exceeding 2700 indiv. m-2. In older reservoirs there were fish, which potential predation pressure led to almost a complete decline of bugs. The reason of bugs poverty in water reservoirs colonized by fish was also probably a small habitat diversity, leading to lack of refuges from predators.
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The aim of research carried out was to describe the zonality and structure of zoopleuston in shallow eutrophic reservoirs. Zoopleuston structure discovered in examined reservoirs was quite different than in depression reservoirs and lakes on Łęczna-Włodawa Lakeland. It was related to morphometry of reservoirs and plant richness of shallow litoral zone. Higher species richness in the water/land contact zone was found which confirms previous studies, however, sometimes zoopleuston abundance showed the opposite pattern. Most differences occurred in dominants composition as in water/land contact zone and on the depth of 0.5 m dominated mainly by small species of Heteroptera: Micronecta minutissima and Cymatia coleoptrata.
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The purpose of this article is to present a new bell type water well construction with circulating treatment and its application. The construction of the water well has been developed and research has been conducted using physical and electrical modelling as well as in the practical field. Researches in this work are of analytical and experimental character. As the results of the research, optimal physical parameters of the constructions have been found and analytical  empirical formulae have been derived to calculate hydraulic parameters. Recommendation for application has been presented. The results received in this work can be used for the application of well construction. Further research is required to improve the physical and the hydraulic parameters of the proposed construction. The work has scientific and practical interest.
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Natural water reservoirs in Europe are very valuable floristic sites. Among them, springs are very important for the preservation of the biodiversity of flora in Poland. The present paper presents a community of water plants that is new to limnocren karst springs in Poland – Potame-tum pectinati Carstensen 1955 from Potametea class. In Europe this community in limnocren karst springs has not been found so far. The paper presents the floristic composition and the ecological requirements of this association.
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Structure of fish communities of five small water reservoirs located near the Chodelka river was investigated during the years 2002, 2008 and 2016. In the analyzed water bodies seven fish were noted, representing four families: Cyprinidae (4 species) and Esocidae, Cobitidae, Peri-cidae and Ictaluridae (1 species each). In the structure of collected fish one protected species (M. fossilis) and one alien species (C. auratus gibelio) were presented. Domination structure of ichthyofauna showed considerable differences. Among the dominant species were: R. rutilus (all five reservoir) and C. auratus. The percentage of each fish species in the biomass was slightly different in relation to the structure of domination expressed by the number of identified individuals. Regardless of the reservoir, larger share held: E. lucius, R. rutilus and C. auratus.
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The paper presents the analysis of structure of fish communities in five small postexcavation reservoirs situated in Tyśmienica valley (Polesie Lubelskie). Special attention was paid to the quality of population of lake minnow Eupallasella percnurus. By the time the extensive drainage works were done in the 60s and 70s of the 20th century, Polesie Lubelskie was rich in small water reservoirs. As a result of drainage of wetlands, many of them disappeared. Among those which still exist, most of them are located in the Tyśmienica valley. The study revealed that the studied reservoir inhabited seven fish species representing two families. It was also found that structure of dominance and biomass structure is very diverse. In each reservoir the dominant species was different. The lake minnow E. percnurus was determined in three reservoires.
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The article presents the results of the analysis of straw obtained from ripening wheat, which was subjected to four water soaking cycles in demineralized water. The soaking was carried out under laboratory conditions at 20°C. As a result, part of mineral matter, including a significant amount of alkaline sodium and potassium salts and substances containing sulfur and phosphorus, was washed out. The process of soaking has a great impact on the chemical composition of ash obtained from water-treated straw, which increased its acidity. The Na2O content in the analyzed ash has decreased by 78%, while the K2O content has decreased by 60%. In turn, the content of water-insoluble, acid-forming SiO2 has increased by 80%. As a consequence, a positive change in the values of indices, on the basis of which the tendency of straw to slagging and deposit formation during the combustion and gasification processes is assessed, has been observed. Already after the second water soaking cycle it became apparent, based on the AI alkali index, that the examined fuel should not cause difficulties resulting from the increased intensity of use of the boiler during the combustion process. Meanwhile, the value of the BAI bed agglomeration index was considered to be safe, indicating a low possibility of bed agglomeration during the combustion or fluidized bed gasification, after the third water soaking cycle. The third of the analyzed indices, the Fu fouling index, did not indicate any tendency to deposit formation during the combustion; however, four water soaking cycles reduced its initial value by 80%. The last of the analyzed indexes, the SR, slag viscosity index did not change its value during the experiment, which, both for the raw straw and after subsequent soaking cycles, indicated that the fuel should have a low tendency to accumulate slag during the combustion process.
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Presented are results of a research on usability of an innovative reclamation process of microwave-hardened moulding sands containing water-glass, combined with activation of binder. After each subsequent stage of reclamation, quality of the reclaimed material was determined on the grounds of measurements of permeability and results of screen analysis. The reclaimed material was next used again to prepare new moulding sand. The sandmix based on high-silica sand prepared with water-glass grade 145, was subject to the following cyclical treatment operations: mixing components, consolidation, microwave hardening, cooling, heating the mould up to 800 °C, cooling to ambient temperature, mechanical reclamation dry and wet. It was found that the used-up and reclaimed sandmix containing water-glass is susceptible to the applied activation process of thermally reacted film of binder and, in addition, it maintains good quality and technological properties of high-silica base. Observations of surfaces of reclaimed high-silica grains with activated film of reacted inorganic binder were carried-out using a scanning microscope. Thanks to properly selected reclamation parameters, the high-silica base can be reused even five times, thus reducing demand for fresh aggregate and inorganic binder.
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In the paper, an attempt was made to evaluate the effect of preliminary wetting of high-silica base during preparation of moulding sands containing a selected grade of sodium water-glass, designed for hardening by traditional drying or by electromagnetic microwaves at 2.45 GHz. In the research, some water was dosed during stirring the sandmix before adding 1.5 wt% of the binder that was unmodified sodium water-glass grade 137, characterised by high molar module within 3.2 to 3.4. Scope of the examinations included determining the effect of wetting the base on mechanical parameters like compression, bending and tensile strength, as well as on technological parameters like permeability, abrasion resistance and apparent density. The research revealed a significant positive effect of adding water to wet surfaces of high-silica base grains on mechanical properties and quality of moulding sands hardened by physical methods, in particular by microwave heating
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Abstrakt

Abstract An attempt has been made to determine the effect of an addition of colloidal suspensions of the nanoparticles of magnesium oxide on the structure of water glass, which is a binder for moulding and core sands. Nanoparticles of magnesium oxide MgO in propanol and ethanol were introduced in the same mass content (5wt.%) and structural changes were determined by measurement of the FT-IR absorption spectra.
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