Volume 30 (2022): Edition 4 (December 2022)

LiDAR-derived digital elevation models (DEMs) have transformed the archaeological study of landscape features, broadened our technical capabilities, and enhanced the accuracy with which terrain relief is described. These models also place demands on how researchers and analysts interpret DEM content in the context of the modern landscape. LiDAR-based DEMs contain modern man-made structures that can significantly influence model properties. Although data are usually filtered and some of these artificial features are removed during bare-earth classification, many terrain interventions remain visible. This large-scale case study applies established methods to a freely available DEM of the Czech Republic in an attempt to evaluate differences between original and filtered DEMs. It applies a fully automated filtering procedure using vector topographic maps to avoid manual corrections that would make the procedure problematic when used on a macro scale. The results of our archaeological GIS analysis demonstrate that this procedure, despite its relative simplicity, can achieve a significantly better representation of a landscape compared to that offered by an unfiltered DEM. Finally, we propose a series of future steps with a view to developing a more comprehensive and accurate model and overcoming its limitations.

The article presents the results of a study involving the properties of flax and hemp-based lightweight concretes as well as the initial characteristics of different straw-based materials. A comparison of straw-based lightweight concretes with and without ordinary Portland cement (OPC) showed that hemp concrete has a 5.6 % higher strength at a 10% deformation, and at the same time, has a 13% greater thermal conductivity coefficient than flax concrete. The physical-chemical study based on a thermal analysis in an air environment has shown that the overall picture of thermal degradation for flax and hemp concretes is similar. Nevertheless, additional peaks of mass loss have been defined for flax concrete. The demonstrated exothermal process is a positive aspect, considering the life cycle of the material and the recycling stage. The paper proposes reference points for the development of new building materials based on straw.

The paper proposes technical solutions for the use of the reagent method of water preparation at coke plants in order to bring it to a quality suitable for use in the circulating water supply system of the PJSC Kharkiv Coke Plan. It is proposed to dilute phenolic water in a biochemical installation in a mixer before purification and to purify water with a flocculant. The paper recommends dosing the flocculant solution automatically using a preparation station. Additional purification of the clarified water is carried out using a filtration unit with a filter media from a layer of quartz sand. The economic effect from the implementation of the technical measures is achieved not only due to the reduction in fresh water consumption by 60 540 m³/year and the cessation of the discharge of phenolic water into the city sewer network, but also the replacement of the reagent with a more efficient one and a decrease in its consumption. It has been found that the introduction of the technical solutions for the circulating water supply system is economically and environmentally justifiable.

This case study aims to investigate the effects of compaction methods on the mechanical behavior of roller compacted concrete pavement (RCCP) mixtures, which consist of the replacement of different cement by 0%, 5%, and 10% limestone by volume fraction and which were compacted by two compaction methods. These methods are commonly discussed in the literature and were developed to simulate the site conditions in the laboratory. A modified Proctor test was adopted in the mix’s proportional process to optimize the aggregate’s percentage content of RCCP. The experimental series consisted of compression and split tensile performance tests to investigate the development of compaction performances at 28 days. The results showed that, where 10% of the cement was substituted by limestone, the RCC gives important flexural strength values compared to the quantity of the cement substitute. Qualitatively, the reduction in the strength of the concrete using the modified Proctor compaction method led to the weakness of the bond between the layers.

The biggest problem with sanitary technology in high-rise buildings is the design of foul water stacks in which high negative pressure and overpressure values must not occur. When pressure exceeds maximum values, water from the trap is ejected, sucked out, or left bubbling in the trap. Measurements by other researchers have shown that when traps lose their function, in addition to the spreading of unpleasant odors, there is also the spreading of various viruses from the sewer and drainage systems. The paper deals with the mathematical analysis and simulation of the pressure resistance of different traps under various boundary conditions, considering the quality of the internal environment. The effect of water evaporation on pressure resistance was also simulated and assessed. The results of the work are clear tables of pressure resistances with a description of their effect on the water level in the trap.

The subject of the article is a physical-mechanical analysis of waterproofing materials exposed to an external environment. Physical and mechanical properties have a direct impact on the life of waterproofing materials and their later remediation. In the introduction, the factors influencing the properties of waterproofing materials are presented. The main part of the article covers the basic possibilities of testing the materials testing the materials, normative testing conditions, and critical aspects of their implementation. In this article we deal with the laboratory testing of a waterproofing membrane based on PVC-P in terms of its degradation from UV radiation, humidity, and the temperature.

The article describes the process of redesigning the intake structure of the fish pass at the Žilina water structure in Slovakia. The existing intake structure does not meet the passability requirements for the target species of migratory fish. A design utilizing intake windows at various levels that cover fluctuations in the water level in the reservoir, which has been successfully used for other water structures, has been proposed. The new design was subjected to hydraulic calculations and simulations in the HECRAS 2D, 2D numerical model in order to achieve the required parameters such as the discharges, depths, and velocities within the limits for the specified fish zone.

Potential changes in a hydrological regime caused by a changing climate represent a crucial source of uncertainty in water resources management. For example, in Slovakia, they may manifest themselves in a decrease in water resources, a change in the seasonality of runoff, and an increase in the extremes of floods and droughts. The research presented here focuses on using the hydrological balance equation to predict changes in the total catchment evapotranspiration under changing climate conditions. Using the TUW rainfall-runoff model and the KNMI and MPI climate change scenarios, the hydrological regime of eight selected basins in Slovakia was simulated for three thirty-year periods from 2010 until the year 2100. The results showed that the growth of total catchment evapotranspiration observed in recent decades is likely to increase further in the future.