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Abstract

Light pollution is one of the types of environmental pollution. The sky illuminated by the excessive light emission is an inherent element of the modern world. This phenomenon has been known for over a century, but research has been carried out only for several decades. Analysis of the brightness of the sky was made for Toruń (Poland) and neighboring areas. The main aim of the study was to study the distribution of brightness of the sky over a medium-sized city. The basic research method was a direct measurement of brightness made with the SQM photometer. The conducted research was carried out throughout the calendar year on 24 measurement stations located in Toruń. Measurement stations represented various types of buildings occurring in every city. On the basis of the obtained data, a map was made showing the extent of light pollution and its intensity, as well as the spatial distribution of this phenomenon. The brightness of the sky was also examined in terms of astronomical and weather conditions. Each aspect is documented in tabular and visual form.

Abstract

The paper discusses the use of an artificial neural network to control the operation of wastewater treatment plants with activated sludge. The task of the neural network in this case is to calculate (predict) the readings of the probe measuring the concentration of nitrate nitrogen (V) in one of the biological reactor tanks. Neural networks are known for their ability to universal approximation of virtually any relationship, including the function of many variables, but the process of “training” the network requires the presentation of many sets of input data and corresponding expected results. This is a difficulty in the case of wastewater treatment plants, because some key process parameters are usually not measured online (samples are taken and measurements are taken in the laboratory), and even if they are, the time intervals are large. Bearing in mind the aforementioned difficulty, this work uses a set of input data consisting only of information that can be measured with measuring probes.

As a result of the conducted experiments a high compliance of the probe’s prediction with the expected values was obtained. The paper also presents data preparation and the network “training” process.

Abstract

Revitalisation of degraded downtown areas is a problem for many cities and towns in Europe. All spatial, economic and social changes result from the expectations of residents together with technical needs. The scope of revitalisation activities results from the diagnosis of the technical condition of the degraded part of the city. The article presents a sample assessment of the technical condition of a tenement house in Kożuchów located within a downtown complex covered by revitalisation plans.

Abstract

This paper discusses the effects of partial replacement of cement with fluidized bed bottom ash on the properties of mortars. The analyzed ash samples originating from four Polish power plants were separated by grain size selection into fine and coarse-grained fractions. This process leads to a creation of derivative samples of differing physical properties and, partially, phase compositions, as tested in XRD and TG analyses. Despite its high water demand, the obtained fine-grained fraction has the potential for application in cementbased composites as a reactive, pozzolanic additive. An acceptable activity index may be reached when the sulfate content is limited, implying benefits of combining the ash with low gypsum cements. The coarse-grained fraction is significantly less reactive, while a high silica and aluminate content is related to improved mechanical properties of the composite. It can, therefore, potentially be used as a quasi-inert additive or a substitute for sand.

Abstract

This study investigates the flexural strength of simply-supported steel–concrete composite beams under two-point loading. A total of four specimens were tested to failure for varying parameters including type of connectors (stud and channel) and number of connectors (two and four). ANSYS software was used to establish the finite element models that can simulate the flexural behaviour of the composite beam. The test results show that a beam with channel connectors performs better than a beam with stud connectors. The composite beam with two connectors between the beam and slab causes additional deflection due to slippage in the connectors, when compared to the beam with four connectors. The results from the analytical model are in good agreement with the experimental results.

Abstract

This paper examines the partial substitution of concrete components by grinded sea mussel shells collected from the coastal region of eastern Algeria. The study proposes the recycling of this waste to reduce the excessive and increasing accumulation of these shells to relieve the marine environment. The problem lies in establishing a perfect integration of the aggregates obtained from the grinded shells of sea mussels in the formulation of various types of concrete. These substitutions significantly affect the rheology of fresh cementitious materials, which is directly related to the development of strength, modulus of elasticity, and the durability of the hardened material. The objective is to partially replace the mineral sand used in the manufacture of ordinary concrete with shell sand from grinded sea mussels, with different substitution percentages of 20%, 25%, 35%, 40%, and 50% of sand volume. The results obtained indicate a marked improvement in the characteristics of fresh concrete with minimum loss in mechanical performance.

Abstract

The study presents an analysis of steel I-beam warping. The calculations were made for hot-rolled IPE200 hinged beams with different lengths. After determining load-bearing capacity using the GMNIA method, the beams were strengthened with bimoment restraints at each end. The changes in critical moment and load-bearing capacity were then evaluated. The study presents the manner in which the material and geometric imperfections have been determined. The GMNIA calculations were conducted using the Finite Element Method in Abaqus software. The results were then compared to results obtained with traditional methods and acquired from LT Beam software.

Abstract

The article discusses selected issues regarding the influence of cultural-historical determinants on functional-spatial development of rural areas. Ecological, economic and social processes taking place in the last decades are examined in the context of the development of local self-governments and the rise of free market economy after Poland’s socio-economic transformation. The process of intensive rural urbanization occurs especially in areas within the impact zone of big cities. It is caused by, i.a., human migration into rural areas and development of areas of business activation. The abovementioned tendencies that occur in the ecological, economic and social context have a significant impact on functional-spatial development. Expansion of housing developments and, in effect, expansion and development of necessary technical infrastructure gives rise to many problems concerning preservation of cultural heritage of the Polish countryside. The pursuit of sustainable development of rural areas is fundamental in regard to ruralist solutions as well as preservation of traditional rural architecture. Cultural-historical determinants play a considerable role in this pursuit, especially in the context of threats that stem from overurbanization of rural areas.

Abstract

The article focuses on the field of innovative trends for efficient data processing in the conduct of research of organic soil pollution using a soil air analyzer for surveys of soil contamination in situ at industrial enterprises in Slovakia. The content of the article is a discourse of theoretical knowledge from the field of the geological environment; the authors’ own survey to monitor the processing and evaluation of the measured values obtained (e.g., CO2, CH4, NEL, BTEX). Currently, standard data processing procedures using the software that is supplied have basic or limited functionality, and the processing time is several hours, including manual and repetitive tasks. As we present in the article, the new Windows PowerShell tool is being used more efficiently, reducing the data processing time which represents an 86% time saving. There is currently no suitable or faster way of evaluating the measured data in Slovakia and the Czech Republic.