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Open access

Jolanta Kozak and Maria Włodarczyk-Makuła

Abstract

The aim of the paper was to determine the effectiveness of the removal of 4, 5and 6 - ring PAHs from coking wastewater using sodium percarbonate Na2CO3∙1,5 H2O2 and iron sulphate in acid condition. The samples were exposing to ultraviolet rays. The source of UV-C radiation was a lamp emitting a wave of light with a length of λ = 264 nm, placed directly above the layer of the samples wastewater. The sodium percarbonate Na2CO3 1.5 H2O2 doses were determined on the basis of stoichiometric calculation. Ratio of iron ions to the hydrogen peroxide released in reaction was: 0.5; 0.4; 0.3; 0.2; 0.1. Before and after the oxidation process, COD and TOC value were determined and as well as concentrations of selected PAHs. The total concentration of tested PAHs before oxidation reached the value of 995 μg/L. The average content of organic pollutants determined by the chemical oxygen demand (COD) was 538 mg/L, while the average content of Total organic carbon (TOC) was 180 mg/L. The use of sodium percarbonate caused the oxidation of organic pollutants and lowering of COD and TOC in the following ranges: 22-46% and 10-30%. For individual PAHs the degradation efficiency was in the ranged from 95% to 99.9%. The degradation efficiency of 4 ring hydrocarbons caused 98% and 5 and 6 ring of hydrocarbons was 98.7% and 99.4%, respectively.

Open access

Marlena Piontek, Katarzyna Łuszczyńska and Hanna Lechów

Abstract

The intense pace of construction work means that technical materials contain so-called technological moisture, which enables the development of biodeteriogenic organisms on building partitions. This article presents the mycological analysis of two buildings in Zielona Góra, whose building partitions were affected by colour deposits. In the first building (a block of flats in the shell and core condition) 7 species of moulds were determined, of which the dominant one was Cladosporium herbarum. In the second building (public utilities building) changes on the walls appeared just after refurbishment and were caused by a species of mould called Strachybotrys chartarum which is hazardous to human and animal life.

Open access

Piotr Szewczyk and Maciej Szumigała

Abstract

The paper presents exemplary static equilibrium paths of an element strengthened while under load. A steel-concrete composite beam was analyzed. The study discusses the effect of strengthening method, initial load values, welding stress, concrete shrinkage and introduction of additional control of distortion state on the course of static equilibrium path. Results calculated in numerical FEM simulation were verified with experimental data and were found to be consistent.

Open access

Andrzej Łączak, Anna Bazan-Krzywoszańska, Maria Mrówczyńska and Marta Skiba

Abstract

The article presents the present situation in terms of energy production from renewable energy sources and perspectives for development, based on research on the existing resources and possibilities of using them. The Lubusz Voivodship is not an important energy producer in Poland. In terms of the amount of energy produced it comes twelfth out of sixteen voivodships. The annual energy production from renewable energy sources is 290,9 GWh, which is 11.6% of the total energy produced. At the end of 2014 there were 73 licensed installations producing electrical energy from renewable energy sources in the Lubusz Voivodship with a total capacity of 189 MW. The largest amount of energy is produced by a pumped storage power plant (91,3 MW). The total capacity of the licensed installations using RES in the Lubusz Voivodship rose from 103 MW in 2007 to about 189 MW in 2014. Research on the existing resources indicates that it is possible to develop RES. Preparations are under way to build 66 new wind farms with a total capacity of 1834 MW [35], 89 photovoltaic power plants with a total capacity of 468 MW, 21 water power plants with a total capacity of about 60 MW, 54 biogas power plants with a total expected capacity of about 67 MW. The total capacity of the RES installations that are planned to be built by 2023 will be 2469 MW. Therefore, in the coming years the installed capacity of RES installations will increase 13 times in the Lubusz Voivodship. There are still no plans to use the energy of deep geothermal waters due to low profitability.

Open access

Tomasz Socha, Krzysztof Kula and Arkadiusz Denisiewicz

Abstract

The paper presents results of experimental tests and a theoretical analysis of the phenomenon of relaxation of chipboard beams. Three linearly viscoelastic rheological models were used for mathematical modeling of the rheology of the studied material. The constants of models were determined using experimental tests and the method of least squares. Through analyses of the obtained results it was found that the rheological behavior of the beam in the specified time is best described by a five-parameter model, consisting of standard and Kelvin-Voigt models connected in series. The final verification of the model can only be ensured by conducting long-term experimental studies using a multistage load program.

Open access

Jacek Sztubecki, Adam Bujarkiewic, Justyna Sobczak-Piąstka, Tomasz Janiak and Jarosław Gajewski

Abstract

Identification of the technical condition of bridge structures should be supplemented by determination of structural displacements in relation to the adopted frame of reference and measurement of changes to the geometry of its individual elements. Of special value are the results of measurements of the same values obtained along an extended service life. They provide an opportunity to compare results, track down tendencies, and more quickly recognise signs of aggravating technical condition of structures.

The paper presents an analysis of changes to the geometry of a bridge structure – a cable– stayed footbridge used for pedestrian and bicycle traffic across the Brda river in Bydgoszcz. Measurements were made by means of surveying techniques within a period of 25 years of the structure service life. The collected data enabled numerous comparative analyses to be conducted. Displacements of footbridge structural elements observed across time led to formulation of recommendations for further use of the footbridge. For instance, recommendations for footbridge adjustment, including improvement of its geometry, were provided. In addition, a general analysis of the effect of footbridge displacements on its static operation was conducted.

Open access

Franciszek Bydałek, Anna Kula and Jacek Mąkinia

Abstract

Phosphorus scarcity is no longer a distant future, therefore the idea of phosphoru recovery is currently widely adopted and developed. Technologies based on the struvite precipitation are consider to address the future P challenges in the optimum way. This paper presents the results of the pilot scale implementation of fluidized bed reactor for struvite precipitation at the wastewater treatment plant. The test was carried out to assess the applicability of the technology in terms of robustness and final product quality, operating at low pH level (7,5-7,8). Obtained struvite pellets were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM) with an energy dispersive spectrometer (EDS). The presence of foreign ions and particulate impurities in the feed source, affected the uniform growth of the crystal structure, resulting in highly porous structure of the pellets. Despite the varying physiochemical conditions, typical for wastewater, obtained pellets were determined with 95% struvite purity.

Open access

Janusz P. Kogut, Elżbieta Pilecka and Dariusz Szwarkowski

Abstract

Due to the significant role and noticeable development of transportation routes running from the north to the south of central Europe, several problems related to the construction and functioning of roads in the Carpathian foothills have been revealed. Recent climate change causes areas, where transport routes are particularly exposed to hazards, to succumb to technical exploitation and degradation. The elimination of the threats related to the activation of landslide phenomena becomes particularly expensive. Old roads, which were once designed for significantly lower axle loads and less heavy traffic conditions, are predominantly exposed. At the present, these roads are heavily exploited and have become overloaded. As a result, both the roadway and the subgrade undergo damage, which causes an increase in dynamic loads, and in potentially endangered areas, the activation of landslides. Landslides in the Carpathian flysch have a peculiar susceptibility to activation due to its geological structure. This paper addresses the problem of monitoring and analysing the effects of a landslide associated with the operation of a transportation route running through the slope of the Carpathian flysch. The studies include both field work and laboratory testing of basic geotechnical parameters. The parameters obtained during the geotechnical investigations, conducted for the purpose of building a numerical model, have been completed. The field work includes surveys made by a terrestrial laser scanner. The study also includes a number of 2D and 3D numerical models. These models, along with the substrate parameters, have been introduced into the FEA package and then calibrated. Subsequently, an analysis of the effects of landslide susceptibility and the behaviour of the road and terrain surface, due to the different variants of the loads, is shown along with the results of surveys.

Open access

Maria Mrówczyńska and Jacek Sztubecki

Abstract

ART (Adaptive Resonance Theory) networks were invented in the 1990s as a new approach to the problem of image classification and recognition. ART networks belong to the group of resonance networks, which are trained without supervision. The paper presents the basic principles for creating and training ART networks, including the possibility of using this type of network for solving problems of predicting and processing measurement data, especially data obtained from geodesic monitoring. In the first stage of the process of creating a prediction model, a preliminary analysis of measurement data was carried out. It was aimed at detecting outliers because of their strong impact on the quality of the final model. Next, an ART network was used to predict the values of the vertical displacements of points of measurement and control networks stabilized on the inner and outer walls of an engineering object.

Open access

Jacek Sztubecki, Adam Bujarkiewicz, Karol Derejczyk and Michał Przytuła

Abstract

The article presents the technology and an analysis of results of engineering structure displacements and deformation measurements. Two measuring technologies using the TDRA65000 laser station from Leica and the FARO Focus M scanner were applied during the tests. Use of the laser station enabled us to define horizontal and vertical displacements of a control network established on the tested facility. Owing to this, it was also possible to transform scanner measuring stations into one integrated unit. The described measurement methodology ensures a high accuracy of scanner station fitting which translates directly into the accuracy of determination of deformations in structural components of a facility. Integration of methods applied in the tests makes it possible to monitor not only displacements of control network points but also the structure as a whole in a uniform coordinate system.