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Number of results: 258
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Abstract

The paper presents the results of laboratory tests into the effects of moisture and the content of two types of bentonite on dielectric properties of moulding sand. The use of electromagnetic waves in foundry industry is becoming more and more popular, which provides to some extent alternatives to conventional drying methods. Experimental studies published so far have shown the validity of using microwaves for drying classic moulding sands with bentonite. However, these studies lack data on the effect of moisture or bentonite content in moulding sand on the real component ε' or imaginary component ε'' of the relative complex electrical permittivity. The presented results may become in the future the basis for the evaluation of the composition of moulding sands, taking into account the phenomena occurring under the influence of electromagnetic field, which directly translates into the quality of the castings made and may constitute an attempt to develop a mathematical model of electric properties of moulding sands.
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Abstract

This article presents the next period in the history of Jadwiga Zamoyska’s School of House Keeping (Szkoła Domowej Pracy Kobiet Jadwigi Zamoyskiej). It was established in 1882 in Kórnik, but as a consequence of oppressive Prussian policy it was moved to Galicia, to Kuźnice near Zakopane, to where the Zamoyski family also moved their residence. When World War I broke out, Jadwiga Zamoyska and her children – Władysław and Mary – stayed in Paris. They could not return to the Austro-Hungarian monarchy because they were French citizens. Zamoyska could supervise the school and give advice in various matters only by mail. It was also difficult to financially support the school, because most of her landed properties were located in Prussian Poland. Besides these hardships, the school could still function, though the number of teachers and schoolgirls diminished. Under the circumstances, the school’s personnel offered a shelter to war refugees and orphans. As the main aim of this school one can point to the upbringing of the schoolgirls in the Catholic faith and the shaping of their personality in such a spirit. The school programme was focused on developing practical skills (cooking, sewing, gardening, farming, etc.) as well as general knowledge in mathematics, humanities and the natural sciences (with special reference to the history of Poland, aesthetic needs were fulfilled by classes in singing and drawing as well as physical education).
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Abstract

The purpose of the “Zakłady Kórnickie” Foundation was to assure fi nancial basis for the institutions founded by Jadwiga and Władysław Zamojski. In the law passed in 1925 the first place among the aims of the Foundation was held by “maintenance and development of The Housework School for Women”. The Foundation, however, was not performing this legal obligation properly. Preliminary school budgets were set at a level that was too low and the funds were paid too late and not to the full amount. This disorganized life at the School. There was not enough money to pay employees’ salaries on time, income tax, health insurance etc. were likewise was not paid. It was necessary to request for loans, buy food and coal on credit, etc. Drastic savings were made at the cost of the School during the great economic crisis. In 1931 two of the three courses run by the School were closed. The situation began to improve in the School year 1934/35. In 1937, besides the traditional course, a two-years’ high school of economics was inaugurated. In 1938 complete reconstruction of the School buildings was started but the outbreak of the war prevented its completion.
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Abstract

The article presents Władysław Jordan’s activity in Turkey during the January Uprising on the basis of his correspondence kept in the Kórnik library. The analysed sources have made it possible to discuss the most important directions of the colonel’s actions and the particular steps he meant to take in order to support the Uprising. The article mentions Jordan’s beliefs, such as his vision of the Nation, his opinion on the Pope’s secular power, and his distinct attitude towards the Ukrainians. The correspondence is valuable not only owing to the information on the diplomatic and military actions undertaken in the period in question, but also due to the individual opinions and emotions, which cannot be found in offi cial documents. The gathered collection of letters is also a great source of knowledge, which sheds light on the relations between Polish activists who were members of the two political groups in exile.
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Abstract

At the end of 2018, when the Hučivá Cave (Hučivá diera, Rausch Keller) was explored in Tatranská Lomnica, profile deposits in rear areas of the cave were found disturbed by an amateur excavation. One stone artefact was first found in back-dirt clay-layer material at the excavation pit, later joined by four more specimens from the cleaned pit profile. The Typological analysis of the artefacts shows, that their closest parallels are found in inventories of the Magdalenian culture. Hučivá is the only cave in the whole Tatras with documented prehistoric settlement and the only Slovak cave with evidence of the Magdalenian culture. The discovery provides new information concerning subsistence strategies of late Pleistocene hunters in High Tatra Mountain landscapes. In light of this discovery, the possibility of seasonal movements along the northern slopes of this mountains range to the east and then south, through the mountain passes to the upper Spiš region should now be considered.
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Abstract

Due to the fact that the landfill deposition of municipal waste with the higher heating value (HHV) than 6 MJ/kg in Poland is prohibited, the application of waste derived fuels for energy production seems to be good option. There is a new combined-heat-and-power (CHP) plant in Zabrze, where varied solid fuels can be combusted. The formation of ashes originating from the combustion of alternative fuels causes a need to find ways for their practical application and demands the knowledge about their properties. Therefore, the present work is devoted to studying the co-combustion of solid recovered fuel (SRF) and coal, its impact on fly ash quality and the potential application of ashes to synthesis zeolites. The major objectives of this paper is to present the detail characteristics of ash generated during this process by using the advanced instrumental techniques (XRF, XRD, SEM, B ET, TGA). The co-combustion were carried out at 0.1 MWth fluidized bed combustor. The amount of SRF in fuel mixture was 1, 5, 10 and 20%, respectively. The focus is on the comparison the ashes depending on the fuel mixture composition. Generally, the ashes characterise high amounts of SiO2, Al2O3 and Fe2O3. It is well observed, that the chemical composition of ashes from co-combustion of blends reflects the amount of SRF addition. Considering the chemical composition of studied ashes, they can be utilize as a zeolites A. The main conclusions is that SRF can be successfully combusted with coal in CFB technology and the fly ashes obtained from coal + SRF fuel mixtures can be used to synthesis zeolites.
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Abstract

W bieżącym stuleciu stosowane są dwa najczęściej spotykane sposoby zaopatrzenia w ciepło kompleksów budynków wielolokalowych. Pierwszym z nich jest zasilanie w ciepło systemowe z sieci ciepłowniczej, a drugim – budowa i eksploatacja lokalnych kotłowni gazowych. Wykorzystanie innych nośników ciepła występuje tylko wówczas, gdy nie jest możliwe podłączenie źródła ciepła do sieci gazowej lub sieci ciepłowniczej. Budynki wielolokalowe charakteryzują się daleko idącą specyfiką w wielu obszarach swojego funkcjonowania, w tym także w zakresie zużycia ciepła. W przypadku kotłowni gazowych konsumpcja ciepła bezpośrednio przekłada się na pobór paliwa gazowego. W artykule przedstawiono i scharakteryzowano zużycie paliwa gazowego przez lokalną dwufunkcyjną kotłownię na podstawie pomiarów wykonywanych z dużą częstotliwością odczytu. Wiedza na temat procesu poboru gazu, nawet w przypadku jeżeli dotyczy to niewielkich ilości, w skali zużycia krajowego, może być podstawą dla poprawy przebiegu tego procesu. Dotyczyć może to nie tylko aspektu ekonomicznego, ale również technicznego, a także punktu widzenia bezpieczeństwa energetycznego oraz efektywności energetycznej. Z tego względu wszystkie podmioty związane z dostawą i odbiorem paliwa gazowego dla zespołu budynków wielolokalowych powinny być zainteresowane poszerzeniem wiedzy na temat tego procesu.
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Abstract

The designing of transmultiplexer systems relies on determining filters for the transmitter and receiver sides of multicarrier communication system. The perfect reconstruction conditions lead to the bilinear equations for FIR filter coefficients. Generally there is no way of finding all possible solutions. This paper describes methods of finding a large family of solutions. Particular attention is devoted to obtaining algorithms useful in fixed-point arithmetic needed to design the integer filters. As a result, the systems perform perfect reconstruction of signals. Additionally, a simple method is presented to transform any transmultiplexer into an unlimited number of different transmultiplexers. Finally, two examples of integer filters that meet perfect reconstruction conditions are shown. The first illustrates a FIR filter which does not require multiplications. The frequency properties of filters and signals are discussed for the second example.
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Abstract

Describing the gas boiler fuel consumption as a time series gives the opportunity to use tools appropriate for the processing of such data to analyze this phenomenon. One of them are ARIMA models. The article proposes this type of model to be used for predicting monthly gas consumption in a boiler room working for heating and hot water preparation. The boiler supplies heat to a group of residential buildings. Based on the collected data, three specific models were selected for which the forecast accuracy was assessed. Calculations and analyses were carried out in the R environment using “forecast” and “ggplot2” packages. A good quality of the obtained forecasts has been demonstrated, confirming the usefulness of the proposed analytical tools. The article summary also indicates for what purposes the forecasts obtained in this way can be used. They can be useful for diagnosing the correct operation of a heat source. Registering fuel consumption at a level significantly deviating from the forecast should be a signal to immediately diagnose the boiler room and the heat supply system and to explain the reason for this difference. In this way, it is possible to detect irregularities in the operation of the heat supply system before they are detected by traditional methods. The gas consumption forecast is also useful for optimizing the financial management of the property manager responsible for the operation of the boiler room. On this basis, operating fees or financial operations with the use of periodic surplus capital may be planned.
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