The exploitation and processing of lignite in the Bełchatów region is connected with the formation of various mineral waste materials: varied in origin, mineral and chemical composition and raw material properties of the accompanying minerals, ashes and slags from lignite combustion and reagipsum from wet flue gas desulphurisation installations. This paper presents the results of laboratory tests whose main purpose was to obtain data referring to the potential use of fly ashes generated in the Bełchatów Power Plant and selected accompanying minerals exploited in the Bełchatów Mine in the form of self-solidification mixtures. The beidellite clays were considered as the most predisposed for use from the accompanying minerals , due to pozzolanic and sorption properties and swelling capacity. Despite the expected beneficial effects of clay minerals from the smectite group on the self-settling process as well as the stability of such blends after solidification, the results of physical-mechanical tests (compressive strength and water repellence) were unsatisfactory. It was necessary to use Ca (OH)2, obtained from the lacustrine chalk as an activator of the self-settling process It was necessary to use lacustrine chalk as an activator of the self-solidification process. The presence of calcium will allow the formation of cement phases which will be able to strongly bond the skeletal grains. Also, the addition of reagipsum to the composition of the mixture would contribute to the improvement of the physico-mechanical parameters. The elevated SO4 2– ion in the mixture during the solidification allows for the crystallization of the sulphate phases in the pore space to form bridges between the ash and clay minerals. The use of mixtures in land reclamation unfavourably transformed by opencast mining in the Bełchatów region would result in measurable ecological and economic benefits and would largely solve the problem of waste disposal from the from the operation and processing of lignite energy.
The article aims at presenting the philosophy and model of the development vehicle to be understood as a new concept and tool to investigate and program local and regional development processes. The practical issues covered by the article include the identification and discovery of development vehicles, the elements of which can be observed in Polish metropolitan areas and agglomerations.
Władysław Łuszczkiewicz was an art historian, artist, pedagogue, an outstanding personality of nineteenth-century Krakow, active in many fields. He was a professor at the Cracow School of Fine Arts, and in the years 1857–1873 and 1893–1895 he was the headmaster of this school. He was a teacher of many artists, of which it is enough to mention only the greatest — Jan Matejko, Stanisław Wyspiański, Józef Mehoffer and Artur Grottger. In 1883, Łuszczkiewicz was appointed the director of the National Museum in Krakow. He managed this institution until his death, that is until 1900.
Among the oldest source materials belonging to the Archive of the National Museum in Krakow, we can find the correspondence of former students of the School of Fine Arts addressed directly to their former teacher — Professor Łuszczkiewicz, who was at this time the director of the National Museum in Krakow. Based on selected letters, the article presents their interesting subject matter and presents the issues in which the students wrote to their Master. The attempt to describe the relation between former students and their master revealed in letters will be made.
This paper aims to characterize and interpret the trends in reserves, resources, and mine production of diatomite in the Czech Republic in last two decades. With more than 2.4 million tonnes of total reserves, 1.6 million tonnes of exploitable (recoverable) reserves, and average annual production of 35 kt, diatomite is not one of the key industrial minerals of the Czech Republic, which ranks among the top 10 European producers. Historical diatomite deposits were situated within the Cheb Basin, where the Holocene Hájek diatomite deposit was abandoned in 1955 because of the establishment of the Soos National Natural Monument. The group of Tertiary diatomite deposits situated in the Central Bohemian Upland ceased extraction when the last deposit (Kučlín) was abandoned in 1966 after depletion of reserves. The last group of diatomite deposits is located within the Southern Bohemian basins, where the last productive deposit, Borovany-Ledenice, is situated. Miocene diatomites are extracted by open pit mining there. Production of crude diatomite varied from 0 to 83 kt, with an average of 35 kt, between 1999 and 2018 according to stockpiles. Raw diatomite is classified into two groups according to the chemical-technological properties. Better-quality diatomite (SiO2 ≥ 72%, Al2O3 ≤ 15%, Fe2O3 < 2.4%, bulk density 450 kg/m3, loss on ignition < 8%) is processed for filtration in the food industry (brewery, wine, and raw fruit juices). Material with lower quality is used in combination with bentonite to prepare cat litter products.
In this paper, numerical results of modeling of acoustic waves propagation are presented. For calculation of the acoustic fluctuations, a solution of the full non-linear Euler equation is used. The Euler equations are solved with the use of a numerical scheme of third-order accuracy in space and time. The paper shows a validation process of the described method. This method is suitable also for an aerodynamic noise assessment on the basis of unsteady mean flow field data obtained from a CFD calculations. In such case this method is called a hybrid CFD/CAA method. The proposed method is numerically decoupled with CFD solution, therefore the information about the mean unsteady flow field can be obtained using an arbitrary CFD method (solver). The accuracy of the acoustic field assessment depends on the quality of the CFD solutions. This decomposition reduces considerably the computational cost in comparison with direct noise calculations.
The presented Euler acoustic postprocessor (EAP) has been used for modeling of the acoustic waves propagation in a cavity and in the flow field around a cylinder and an aerodynamic profile.
The current study was aimed to evaluate the industrial effl uents biodegradation potential of an indigenous microorganism which reduced water pollution caused by these effl uents. In the present study biodegradation of three textile industrial effl uents was performed with locally isolated brown rot fungi named Coniophora puteana IEBL-1. Response Surface Methodology (RSM) was employed under Box Bhenken Design (BBD) for the optimization of physical and nutritional parameters for maximum biodegradation. Quality of treated effl uents was checked by study of BOD, COD and analysis through HPLC. Three ligninolytic enzymes named lignin peroxidase, manganese peroxidase and laccase were also studied during the biodegradation process. The results showed that there was more than 85% biodegradation achieved for all three effl uents with decrease in Biological Oxygen Demand (BOD) and Chemical Oxygen Demand (COD) below the recommended values for industrial effl uent i.e. 80 mg/L for BOD and 220 mg/L for COD after optimization of nutritional parameters in the second stage. Analysis of samples through HPLC revealed the formation of less toxic diphenylamine, 3-methyldiphenylamine and N-methylaniline after treatment. The ligninolytic enzymes assays confi rmed the role of lignin peroxidase (LiP), manganese peroxidase (MnP) and laccase in biodegradation process. Lignin peroxidase with higher activity has more contribution in biodegradation of effl uents under study. It can be concluded through the results that Coniophora buteana IEBL-1 is a potential fungus for the treatment of industrial effluents.
This paper provides a discussion concerning results of CO2 removal from a gas mixture by the application of aqueous solutions of ethanoloamine (MEA) and 2-amino-2-methyl-1-propanol (AMP) promoted with piperazine (PZ). The studies were conducted using a process development unit. Research of such a scale provides far more reliable representation of the actual industrial process than modelling and laboratory tests. The studies comprised comparative analyses entailing identical energy supplied to a reboiler as well as tests conducted at similar process efficiencies for both solvents. The results thus obtained imply that using AMP/PZ enables reduction of the solvent heat duty. Moreover, while using AMP/PZ temperature decrease was also observed in the columns.
Gas atmosphere at the sand mould/cast alloy interface determines the quality of the casting obtained. Therefore the aim of this study was to measure and evaluate the gas forming tendency of selected moulding sands with alkyd resins. During direct and indirect gas measurements, the kinetics of gas evolution was recorded as a function of the temperature of the sand mixture undergoing the process of thermal destruction. The content of hydrogen and oxygen was continuously monitored to establish the type of the atmosphere created by the evolved gases (oxidizing/reducing). The existing research methodology [1, 7, 8] has been extended to include pressure-assisted technique of indirect measurement of the gas evolution rate. For this part of the studies, a new concept of the measurement was designed and tested.
This article presents the results of measurements and compares gas emissions from two sand mixtures containing alkyd resins known under the trade name SL and SL2002, in which the polymerization process is initiated with isocyanate. Studies of the gas forming tendency were carried out by three methods on three test stands to record the gas evolution kinetics and evaluate the risk of gas formation in a moulding or core sand.
Proprietary methods for indirect evaluation of the gas forming tendency have demonstrated a number of beneficial aspects, mainly due to the ability to record the quantity and composition of the evolved gases in real time and under stable and reproducible measurement conditions. Direct measurement of gas evolution rate from the tested sands during cast iron pouring process enables a comparison of the results with the results obtained by indirect methods.
The paper presents a production scheduling problem in a foundry equipped with two furnaces and one casting line, where the line is a bottleneck and furnaces, of the same capacity, work in parallel. The amount of produced castings may not exceed the capacity of the line and the furnaces, and their loads determine metal type from which the products are manufactured on the casting line. The purpose of planning is to create the processing order of metal production to prevent delays in the delivery of the ordered products to the customers. The problem is a mix of a lot-sizing and scheduling problems on two machines (the furnaces) run in parallel. The article gives a mathematical model that defines the optimization problem, and its relaxed version based on the concept of a rolling-horizon planning. The proposed approaches, i.e. commercial solver and Iterated Local Search (ILS) heuristic, were tested on a sample data and different problem sizes. The tests have shown that rolling horizon approach gives the best results for most problems, however, developed ILS algorithm gives better results for the largest problem instances with tight furnace capacity.
The graphite form in cast iron is the structure parameter deciding on its all physical and mechanical properties. Three basic forms of graphite: flake, vermicular (compact) and nodular (spheroidal) are singled out in standard cast iron grades, without a heat treatment. Standards of individual grades of cast iron the most often allow only the homogeneous graphite form, sometimes with addition of 5÷10% of the other form. The interesting and - in the authors opinion - future-oriented material can constitute cast iron in which various forms of graphite are present, e.g. in comparative amounts: spherical and vermicular cast irons. Cast iron within which graphite occurs in two or three forms was named „Vari-Morph” (VM) cast iron, i.e. the one in which spherical and vermicular or vermicular and flake graphite occur in a wide range of proportions. The results of investigations of these new cast iron grades and their properties are presented in the hereby paper.
The article presents a new modification of the the least squares Prony method. The so-called variable-frequency Prony method can be a useful tool for estimating parameters of sinusoidal components, which, in the analyzed signal, are characterized by time-dependent frequencies. The authors propose use of the presented method for testing the quality of electric energy. It allows observation of phenomena which, when using traditional methods, are averaged in the analysis window. The proposed modification of least squares Prony method is based on introduction and specific selection of a frequency matrix. This matrix represents frequencies of estimated components and their variability in time.
The subject of this article is the architecture of sacral buildings so far classified by scholars as one group of buildings (“the Tarłów group”) with similar stylistic features, designed by an anonymous architect. A critical analysis of the current research material allows us to limit their numbers to the parish church in Gołąb (1626–1634), the collegiate church in Klimontów (1643–1650), the parish churches in Tarłów (before 1647) and Jedlińsk (before 1645), and the Rosary Chapel (c. 1642–1650) at the parish church in Kazimierz Dolny. The church in Tarłów with its arrangement of vaults and lunettes seems to be reliant on the leading sacral architectural designs created in the first half of the 17th century in Northern Italy and the Kingdom of Bohemia. Its colonnaded façade, which was the first of its kind in Central Europe, repeated at least on the first floor the unrealized designs of the façade of the church of SS. Ambrogio e Carlo al Corso in Rome, designed by Onorio Longhi and Martino Longhi the Elder. On the other hand, in the case of the side chapels of the church in Jedlińsk and the Rosary Chapel, their columnar articulation refers to the completed or unrealized projects by leading late 16thand early 17th-century Italian architects such as Ottaviano Mascarino, Giovanni Maria Ricchini, Francesco da Volterra and Carlo Maderno. The system of vaults in the Klimontów collegiate church and the Tarłów church recalls the churches of Our Lady of Victory in Prague (1611–1613), St. James in Jičín (after 1628), and the Church of the Assumption of the Virgin Mary in Stará Boleslav (1620s–1630s). The eclecticism of the spatial arrangement of the buildings and the staging of the façades and interiors prove a good knowledge of early modern Italian architecture. In the absence of archival sources, it is at present difficult to identify their architect. However, the builders of these structures were guild craftsmen operating in the former Sandomierz and Lublin provinces. An analysis of their working methods links the Tarłów church to the mason Lorenzo Senes, the builder of the collegiate church in Klimontów and the Krzyżtopór castle in Ujazd (1621–1644). In Tarłów and Kazimierz Dolny, Senes cooperated with the still anonymous Master of Tarłów, the author of stucco and terracotta decorations.
The paper presents the method for multicriteria design of a synchronous generator voltage regulator. The results of the voltage regulator polyoptimisation are compromise sets for a classic controller of type PI and fuzzy logic controller of type Takagi-Sugeno-Kang. A genetic algorithm is used to solve the polyoptimisation problem.