The study is focused on the objectification of an assessment of the quality of an in-stream habitat in mountain and piedmont streams by the decision-making Instream Flow Incremental Methodology (IFIM) due to climate change. The quality of the habitat was assessed on the basis of a bioindication, represented by ichthyofauna. Sixty-four reaches of 47 watercourses in five river basins in Slovakia, in which ichthyologic, topographic, and hydraulic measurements were performed, were evaluated. The effect of the physical characteristics of the stream channel on the quality of the in-stream habitat has been verified on a number of reference reaches in which the measurements were performed at different water levels. From the set of the data measured, an analysis aimed at determining the impact of individual characteristics on the quality of an in-stream habitat has been carried out. The results show the optimum ratio of the weights of the flow velocity and water depth for an assessment of the quality of an in-stream habitat due to climate change.

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A natural channel differs from a prismatic one by its rich variability. Regulated rivers have a geometrically regular shape that is not suitable for the instream biota. The morphology of a regulated river is the main cause of habitat changes. The article provides the results of research that was focused on assessing the impact of a channel's morphology on the instream habitat preferences by ichthyofauna. In the article the ichthyofauna is represented by brown trout (Salmo trutta m. fario). During the years 2015 and 2016, research was carried out for 13 reaches of mountain watercourses in Slovakia. These reaches were geodetically measured, and a hydraulic model was created. The ichthyological survey was focused on the fish's habitat preferences. A set of data was created from the results that was statistically evaluated by cluster analysis, and the correlation relations for the abiotic and biotic characteristics of the watercourses were evaluated. The individual evaluations provide mutually compatible results. It can be concluded from the results that bioindications by fish provide reliable results in relationship to the changes in habitats in regulated rivers. There was an unambiguous statistical correlation in the preferences of brown trout in the regulated and natural rivers.

This study investigated the effects of three pore-forming agents on the properties of the fired clay body applied in the production of lightweight bricks for the building envelopes. Test samples were made from clay raw material already containing two combustible pore-forming agents (sawdust and cellulose sludge). A part of this research was focused on studying the influence of adding two combustible pore-forming agents (molasses and cornstarch) and a chemical additive Vuppor to the claw raw material. Testing of the material properties showed that although the three samples had almost the same pore volume, their thermal conductivities varied. These findings led to an important conclusion. The pore size of 1–200 µm (filled with not only air but also biomass ash) reduced the thermal conductivity, and conversely, an increase in the small pore size less than 1 µm increased the thermal conductivity of the fired clay body.

A plan to reduce CO2 emissions is a priority these days. Brick industry contributes to the increase of these emissions mainly through the use of combustible pore-forming agents such as sawdust, cellulose, and coal sludge. These agents are used to improve the thermal insulation properties of brick products, and the suppliers regularly increase the prices of these agents based on their high consumption. Therefore, in an effort to reduce raw material expenses and CO2 emissions, brick manufacturers are looking for new possibilities while maintaining the quality of their products. This article discusses the possibility of using industrially manufactured product Vuppor as an additive as a replacement for combustible poreforming agents. The presence of this additive in the fired clay body increases the proportion of pores, especially with a size range between 0.1 and 5 µm, having a positive impact on the reduction of its thermal conductivity. With a 0.5 wt.% dose of Vuppor additive, the brick production costs and thermal conductivity can be reduced by 20 % and 12 %, respectively, while also achieving reductions in CO2 emissions over 60 %. Consequently, the combustible pore-forming agents can be used in a more environmentally friendly manner, for example in the furniture industry, the biogas production, and the like.

Fibre concrete requirements are only met if the fibres in its volume are evenly distributed. Their direction and orientation should be equal around each axis in a three-dimensional space. The requirement is that the fibres to be evaluated in the final hardened fibre concrete are cut from fibre concrete sections. Homogeneity can also be verified on fibre-concrete cross-sections. Fibre Position Evaluation is a mathematical task that is not presented here but is currently made up of the results of this experiment. In the first step, it was necessary to prepare samples to obtain the necessary cross-sections. In the next step, it was necessary to create conditions by creating a contrast between the fibres and the concrete to create software capable of detecting fibres. In this paper, the principle of detection of fibres based on the detection of cut section images is described. There are several methods used to highlight the concrete matrix over the fibres. Also presented are the results of adding and detecting fibres.

The specific nature of plastics causes specific problems in waste management. Plastics are relatively inexpensive and versatile with the potential for versatile use in industry, which has led to their rapid development over the past century, which still persists. The aim is to look for the possibility of reusing plastic waste as one of the lightweight filler fillers. It used plastic recycled material recycled from EVA plastic packaging and polystyrene recycled material in various proportions. All are among the medium-recyclable plastics according to their recycling rate. The experimental part of the work is devoted to the verification of the effect of the filler dose on the monitored physical and sound absorption parameters.

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