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Number of results: 20
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Abstract

The article presents the possibility of using the Cobb-Douglas production function for planning in a turbulent environment. A case study was carried out – the Cobb-Douglas function was used to examine the condition of the Polish hard coal mining industry and the progress which has been made after undertaking certain activities aimed at increasing the competitiveness of coal companies over recent years. Only the correct and confirmed identification of the causes of irregularities in the production process can allow for the introduction of effective remedies. The effectiveness of the solutions proposed by the author has been confirmed thanks to the simulation during which the impact of the proposed production strategy on the parameters of the CD function was examined. Three variants of production functions models were created and production productivity rates and marginal substitution rates were determined. The results enabled the verification of the progress of restructuring as well as identification of the origin of the observed problems and comparison of the current state with the results of analyses carried out in previous years. Scenarios of possible trend developments for the factors introduced into the function model in order to present remedial measures that could improve the process of hard coal extraction were created. The scenarios were created using the ARIMA class models. Which scenario is the most favourable was determined. A computer program, created by the author, for optimising the level and use of labor resources at the level of the entire coal company has been presented.
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Abstract

The article presents a synthetic analysis of the crude oil market in Poland. As of today, this safety is provided mainly on the basis of native lignite and hard coal resources. However, the analysis of the hard coal market conducted by the authors indicates that the carried out mining restructuring (among others) led to an excessive reduction of mining volume and employment level in the hard coal mining sector. This led to a precedent situation when Poland became an importer of this energy carrier. In addition, the European Union’s requirements for greenhouse gas emissions must be taken into account. In connection with the above, it is necessary to search for new energy sources or technologies that enable hard coal to meet the requirements. It is possible to apply the so-called clean coal technologies that allow the greenhouse gas emissions generated during coal combustion to be reduced. As of today, they are not used on a mass scale, because the use of this type of technology involves additional financial expenses. However, taking into account that technologies have been growing faster and faster, are modernized in a shorter time, making a breakthrough discovery took hundreds of years, now it is often a few months, clean coal technologies can become the optimal solution in the near future. It is also necessary to diversify the sources of obtaining imported energy carriers. The article describes coal and crude oil in terms of their mutual substitution. The article is a continuation of research conducted by the authors. Previous publications presented considerations on analogous topics related to natural gas and renewable energy sources. The crude oil market in Poland was analyzed and forecasts for oil extraction and the demand in the world and Poland by 2023 were presented. The SARIMA model was also created. The model made it possible to obtain oil an prices forecast.
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Abstract

In recent years, the outsourcing of a variety of different activities has been more commonly observed in the coal mining industry. This is connected with employing workers by external companies. These practices are not necessarily perceived as good ones by mines’ employees because they may influence their remuneration directly or indirectly. Firstly, as external employees treat work in mining company as a source of a quick income. Therefore, external companies often calculate their employees compensation not based on working time (i.e. hours) but on the basis of a specific, accomplished task. Such employment is called piecework, whereas the workers employed in this kind of system are called output workers/piece workers. Therefore, to receive higher wages in these companies, employees carry out their tasks faster and more efficiently. This, in turn, can affect the standards of workers employed by the mining company. In addition, outsourced workers are often retired miners, so the costs incurred by employers are significantly lower. In addition, in order to not to lose the retirement benefit, they work for a much lower rate. On the other hand, outsourced work can be done in a hurry (on a piece rate), which is not conducive to compliance with safety regulations, therefore mine employees may feel unsafe. This article aims to present how mine employees assess outsourcing underground works. In order to achieve this aim, a survey was carried out among employees of one of the coal mine companies in Silesia. Participants of the survey were randomly chosen among underground miners employed at one mine company. The survey was anonymous which obviously might have influenced respondents’ honesty in answering. The survey was carried out in several mines of the chosen company. In some of them the survey was carried out online and in the remaining ones it was filled out on paper. Analyzing the survey results allowed for a better understanding of the reasons of the disapproval of outsourcing underground works. This, in turn, may be used for better human resources management including, in particular, planning an incentive based pay system.
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Abstract

The level of sales of a given good depends largely on the distribution network. An analysis of the distribution network allows companies to optimize business activity, which improves the efficiency and profitability of a company’s sales with an immediate effect on profit growth. The so-called spatial analysis is highly useful in this regard. The paper presents an analysis of the network of authorized dealers of the Polish Mining Group for the Opolskie Province. The analysis was done using GIS (SIP) tools. The purpose of the analysis was to present tools that could be used to verify an existing distribution network, to optimize it, or to create a new sales outlet. The prresented tools belong to GIS operations used to process data stored in Spatial Information System resources. These are so-called geoprocessing tools. The article contains several spatial analyses, which results in choosing the optimum location of the distribution point in terms of the defined criteria. The used tools include a spatial intersection and sum. Geocoding and the so-called cartodiagram were also used. The presented analysis can be performed for both the network of authorized retailers within a region, a city or an entire country. The presented tools provide the opportunity to specify the target consumers, areas where they are located and areas of potential consumer concentration. This allows the points of sale in areas with a high probability of finding new customers to be located, which enables the optimal location to be chosen, for example, in terms of access to roads, rail transport, locations of the right area and neighborhood. Spatial analysis tools will also enable the coal company to verify its already existing distribution network.
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Abstract

In order to prepare a coal company for the development of future events, it is important to predict how can evolve the key environmental factors. This article presents the most important factors influencing the hard coal demand in Poland. They have been used as explanatory variables during the creation of a mathematical model of coal sales. In order to build the coal sales forecast, the authors used the ARMAX model. Its validation was performed based on such accuracy measures as: RMSE, MAPE and Theil’s index. The conducted studies have allowed the statistically significant factors out of all factors taken into account to be identified. They also enabled the creation of the forecast of coal sales volume in Poland in the coming years. To maintain the predictability of the forecast, the mining company should continually control the macro environment. The proper demand forecast allows for the flexible and dynamic adjustment of production or stock levels to market changes. It also makes it possible to adapt the product range to the customer’s requirements and expectations, which, in turn, translates into increased sales, the release of funds, reduced operating costs and increased financial liquidity of the coal company. Creating a forecast is the first step in planning a hard coal mining strategy. Knowing the future needs, we are able to plan the necessary level of production factors in advance. The right strategy, tailored to the environment, will allow the company to eliminate unnecessary costs and to optimize employment. It will also help the company to fully use machines and equipment and production capacity. Thanks to these efforts, the company will be able to reduce production costs and increase operating profit, thus survive in a turbulent environment.
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Abstract

The paper presents the possibilities of quantitative analysis of results obtained from CT examination of organs and anatomical structures of the upper respiratory tract. The presented results of the analysis were obtained using proprietary software developed in the MATLAB 2018b environment (Image Processing toolbox). The software enables to visualize the original results of CT scan and, after evaluating the visible structures, enables to select the area to be subjected to quantitative analysis. After the initial identification of an area of interest requiring detailed diagnostics, its volume and the surface areas of individual cross-sections are calculated in the area separated for examinations. A graphical presentation of the analysis results – the surface areas of selected cross-sections possible to visualize in two- and three-dimensional space – enables quick analysis of changes in the examined region.
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Abstract

The presence of inorganic elements in solid fuels is not only considered a direct source of problems in the furnace but is also connected with the release of pollutants into air during combustion. This article focuses on the sintering characteristics of biomass and coal ashes, in particular on the leaching processes, and their impact on the tendency to sinter ash. Biomass and coal ash with high alkali metal concentration can deposit in boiler sections and cause severe operating problems such as slagging, fouling and corrosion of boiler and heat exchanger surface, limiting heat transfer. Two biomass types and one coal ash with different origin and different chemical compositions were investigated. A sequential leaching analysis was employed in this study to elucidate the modes of occurrence of metals that can transform into fuel extract. Sequential leaching analysis was conducted as a two-step process: using distilled water in the first step and acetic acid in the second step. The chemical composition of ashes, before and after each step of the leaching processwas studied using ICP-OES method. The standard Ash Fusion Temperature (AFTs) technique was also employed to assess the sintering tendency of the tested samples. It was observed that the presence of key elements such as sodium, potassium, magnesium and sulphur (elucidated in the leaching process) plays a significant role in sintering process. The sintering tendency enhances when the concentration of these elements increases.
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Abstract

“Wartowice” tailings pond was closed in 1989, resulting in 232,4 ha tailings pile requiring reclamation. The major problem is heavy metals presence and poor nutrient conditions and physicochemical structure of soil which disturbs the plants development. In order to assess the real condition of studied area the complete biological characteristic has been done. The physicochemical conditions were assessed altogether with phytosociological, microbiological and toxicological studies of deposits. We recorded only 27 species of vascular plants belonging to 15 families on the tailings pond of which 5 belong to Rosaceae, 4 to Asteraceae and 3 to Poaceae and Saliceae. Species inhabiting the tailings depended on their dispersal capacity, metal tolerance and rhizome strategy. Microbiological analyses revealed the low number of bacteria and fungi on the tailings pond, apart from the small uplift area where the plants were indentified. Bacteria identified on the tailings pond were classified to 8 genera. The low number of bacteria suggests the lack of nutrients which affects the development of soil microflora. Toxicity tests showed that post-flotation sludge is not toxic to microorganisms because of its high pH. Some plants, such as lucerne could even influence positively the microorganisms development what has been proved in our studies. The tailings toxicity was higher towards producers, where Secale cereale appeared to be the most sensitive species. Amendment with topsoil from adjacent areas can influence positively the phytotoxic properties of tailings and enrich them into native seeds.
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Abstract

The paper presents the results of the mechanical, electrical, CCSEM and XRD measurements of hard coal, conducted in simulated conditions of sintering in atmospheres of O2/CO2,. The changes of the coal ash resistivity are correlated with the content of the oxides and with the sintering temperature determined by the mechanical test and Leitz method. The SEM-EDS analysis was conducted for deposits on the probe. The changes of the measured ash samples, observed during sintering process in O2/CO2 atmosphere, were discussed in the ash microstructure point of view.
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Abstract

The paper presents results of coal behaviour during combustion in oxy-fuel atmosphere. The experiment was performed using 3 meter long Entrained Flow Reactor and 1 meter long Drop Tube Reactor. Three hard coals and two lignites were analysed in order to investigate NOx, SO2 emission and fly ash burnout. The measurements were performed along and at the outlet of a combustion chamber for one- and two - stage combustion. In the second stage of the experiment, kinetic parameters for nitrogen evolution during combustion in oxy - fuel and air were calculated and the division of nitrogen into the volatile matter and the char was measured. The conducted experiment showed that emissions in oxy - fuel are lower than those in air.
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Abstract

City is a formal expression of social relations. It is a kind of ethos and dreams connected with history and identity of individuals. It is a structure with thousands of meanings. The opportunities it creates can lead to an outstanding civilization. At the same time it reveals all negative aspects of living. City is a collection of separate individuals combined with common perception of spatial affi liation and identity development. It is worth writing about city because despite its well-defi ned value it is an elusive being. In spite of being a kind of collective needs it is still on the move, transforms all the time reflecting human emotions. Existence of city as a phenomena itself is a symbol of realization of people’s most basic needs and the history of its development shows growing complication and diversification of expectations related to it. City along with is diversity reflects human beings of a particular time. It is a spotlight in which both successes and failures of communities and individuals in each epoch can be seen. Thanks to its interdisciplinary character it can be perceived as multidimensional place. It is a multifaceted organism with high hopes and unlimited opportunities. Differences in perception which are due to a number of its users results in a wide range of problems and expectations. Expectations of local communities and individuals of a whole city vary. As a result, what we call a city landscape must be very vague and differs depending on a particular field which is taken into consideration. The number of opportunities and city-related issues is infi nite. In the dissertation below, however, three factors are the crucial ones: structure, meaning and city phenomena as a landscape. Thanks to the interpretation of model and genius loci as well as defining social expectations we have managed to conceive the phenomena of spatial identity. We have decided on this method referring directly to the concept of landscape. City is in here widely defined between urban aspects of landscape and city landscape. We have tried to understand what city is in terms of landscape, where it comes from and where it goes to. It is a trial of translation the Gaugin’s method: where are we from? Who are we? Where are we going to? into the language of present perception of some particular aspects of town planning. We live at times of the unprecedented technological change which is followed by a social change. It all must have an impact on how city is perceived, what it looks like, how it is to live there and what it is going to be like – what the future has in store. We have tried to bring the reader’s attention to the problems and issues which had appeared before the advent of reality we live in. We have focused on what may have led to a kind of city crisis at the edge of 19th and 20th centuries and some radical solutions trying to overcome the arisen problems and its consequences today. Both its pompous character and sentimentalism of town planning and architecture in the early 20th century have made us be bored with form which is felt in many parts of the world even today. Another aspect of our work covers understanding city in social terms as well as contemporary and future solutions. We are of the opinion it is worth asking questions referring to the future and at the same time regarding its current state and recent past. It is commendable to look for particular tools and solutions. Three dimensions which are covered by the book are figurative. Structure – which is everything we perceive as a kind of a template, identifi cation – we assign to city. It is responsible for recognition, adaptation to some forms by which we defi ne space. Meaning is a step forward. While the structure’s equivalent is „I can see”, the meaning equals to „I know”. Meaning does not exist as a city without structure just like structure does not exist without meaning. Things don’t just exist, they have some characteristics and purpose and it refers to trees, buildings and all other urban elements constituting city in all steady and temporary aspects and time dimensions. Meaning is also interpretation and emotion regarding both community and individual. It is the answer to the question „why?” Some particular places and spaces are linked to some particular values which identify them. This system of values is a must to be able to interpret what space we are dealing with and its diagnosis. Meaning is very much about social aspect too. It has to do with perception and remembering city and it is connected with knowledge, tradition and culture of places. Another aspect linked to relations in city landscape combines other aspects and constitutes something to which city refers to. Phenomena is contribution and verifi cation. The way city works is fundamental to all city residents and users. A key to such understanding a city is the term of genius loci. By singling out objects, order, time, character and light we are able to widely identify essence of space and particular places. The graphic model by Panofsky acts here as a verifying tool. City landscape as a form is of great importance here. The sense of beauty is as essential as the way the city works. Social perception of city is not only shaped by the way it is used, but also by the fact what city is like and how it is perceived. Spatial order is an incredibly important factor understood here as everything what accommodates vaguely defi ned beauty and what is connected with its particular structure, history and identity. All these factors contribute to the value of city landscape. When it comes to city landscape studies social aspect is emphasized by the impact of humanities, especially sociology, which perfectly shows expectations related to space. Cities are built and seen in the context of particular tradition, culture and history. Their skyline and ways of functioning are embedded in mentalities of societies which they represent. Despite their diversity from the global point of view they are susceptible to similar trends resulting in crisis or prosperity periods. They are economic archetypes of success.
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Abstract

Multidimensional, variety of saving memories ways in landscape is visible in creation of commemorative spaces. These meaning is strictly connected with the most important events and persons in history of the country. Authors of article in their research are concentrated on commemorative space with monuments example in Poland and the world presence in landscape design meaning. They are announced by landscape analysis methods to recognition of structure, meaning and phenomena of chosen objects in genius loci categories. In Study of Conditions and Directions of Space Development Capital City of Warsaw is found the record that “commemorative resource” is not enough examined and protected. The aim of elaboration is indication of tendencies in aspects of location, space relations and meanings of memory places.
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Abstract

Recently, the search for new effective energy production solutions has been focused on the production of electricity using renewable and environmentally friendly carriers. This resulted in an increased interest in PV cells and cogeneration systems. The article looks at the main factors affecting their operational parameters against the background of the development history of subsequent generations of PV cells. Average daily solar radiation and wind velocity in Lodz were characterized. The research was done on a static and tracking system with a total peak power of 15 kWp and a 30 kW microturbine. PV panels are installed on the building of the Institute of Electrical Power Engineering of the Lodz University of Technology and they work as part of DERLab. A microturbine is inside the building. Energy measurements were carried out in 2016 giving grounds for the analysis of energy efficiency and financial analysis of the energy supply in buildings. Energy yields in the static and tracking system as well as percentage coverage of electricity from PV cells and microturbines were assessed. The distribution of monthly savings, annual savings of energy costs and the payback time of the investment costs of the systems subject to the test were determined. The research we have done allows us to say that the energy produced by follow-up modules is about 3 times greater than that generated in stationary modules. On the other hand, the annual savings of energy costs using gas micro-turbines are about 10 times higher than those of lagging panels. The analysis shows that it is possible to determine the profitability of the microturbine and photovoltaic panels use despite large financial outlays. The payback period of investment outlays is about 12 years when using the installation throughout the year.
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