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Abstract

The trend of reducing electricity consumption and environmental protection has contributed to the development of refrigeration technologies based on the thermal effect of adsorption. This article proposes a methodology for conducting numerical simulations of the adsorption and desorption processes. Experimental data available in the literature were used as guidelines for building and verifying the model, and the calculations were carried out using commercial computational fluid dynamics software. The simulation results determined the amount of water vapor absorbed by the adsorbent bed and the heat generated during the adsorption process. Throughout the adsorption process, the inlet water vapor velocity, temperature, and pressure in the adsorbent bed were monitored and recorded. The results obtained were consistent with the theory in the literature and will serve as the basis for further, independent experimental studies. The validated model allowed for the analysis of the effect of cooling water temperature on the sorption capacity of the material and the effect of heating water temperature on bed regeneration. The proposed approach can be useful in analyzing adsorption processes in refrigeration applications and designing heat and mass exchangers used in adsorption systems.
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Authors and Affiliations

Szymon Janusz
1 2
Maciej Szudarek
3
Leszek Rudniak
4
Marcin Borcuch
2

  1. Cracow University of Technology, Jana Pawla II 37, 31-864 Kraków, Poland
  2. M.A.S. Sp z o.o., Research and Development Department, Składowa 34, 27-200 Starachowice, Poland
  3. Warsaw University of Technology, Institute of Metrology and Biomedical Engineering, sw. Andrzeja Boboli 8, 02-525 Warszawa, Poland
  4. Warsaw University of Technology, Faculty of Chemical and Process Engineering, Warynskiego 1, 00-645 Warszawa, Poland
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Abstract

A significant problem with the effective functioning of the hard-coal mining industry, especially in relation to mining enterprises and mines located in the Upper Silesian Coal Basin, are the high costs of mining. This is due to many reasons, among which, an important aspect is the ineffective use of the working time of mining faces. The unsatisfactory use of working time caused by unplanned shutdowns of mining faces is a significant reason for the fact that the use of the production potential of the expensive, modern mechanized systems built in them, with the production capacity of around 1,000–1,500 tons per hour, is relatively small – the average daily volume of mining from a longwall working is most often around 3,000 tonnes or even slightly less. A significant reason for this is the occurrence of a large number of interruptions in the continuity of their work, which is mainly caused by equipment failures, the impact of unfavorable geological and mining conditions or technological shutdowns.
The article deals with the problem of the unsatisfactory level of the effective use of working time in mining faces (longwalls) in Polish hard-coal mines. The main reason for this is the occurrence of a large number of unplanned stops and interruptions, sometimes lasting several days. Their elimination or at least reduction would significantly contribute to the improvement of the existing situation. The condition for this, however, is reliable analyses aimed at detailed the identification of their causes. It was proposed to use three methods – the analytic hierarchy process (AHP), the development of the Pareto-Lorenz diagram and the 5 Whys method. Examples of their practical application are also presented.
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Authors and Affiliations

Patrycja Bąk
1
ORCID: ORCID
Marian Turek
2
ORCID: ORCID

  1. AGH University of Science and Technology, Kraków, Poland
  2. Central Mining Institute, Katowice, Poland
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Abstract

The article presents the socio-environmental policy of the selected entities operating in the rock raw materials industry. Integrated reports prepared by mining entrepreneurs may be a source of verification of the “raw materials policy”, identified as a manifestation of the care of these entities for the environment and society. Rational deposit management is closely related to the raw material policy. The preparation of integrated reports is compulsory from as of January 2017 (in accordance with Directive 2014/95/EU) for large companies in the EU. These are companies that fulfil the criterion of the number of employees (500 persons for public interest entities required under the Directive to extend non-financial information) and the balance sheet total (>EUR 20 million EUR) or net income (>EUR 40 million EUR). This obligation mainly applies to mining enterprises involved in mining and processing hard coal, lignite or copper ore. The mining of non-energy raw materials is no less important. The rock raw materials are used, among others, in road construction, railways or construction, in the form of aggregates, and stone elements, and also in the paper, cosmetic and ceramic industries. The article aims to analyseanalyze the socio-environmental policy of mining entrepreneurs dealing with the exploitation of rock raw materials in accordance with latest GRI guidelines (Global Reporting Initiative – G4). The scope of activities was compared in accordance with the principles of sustainable development of three large companies operating in the Polish mining industry: Cemex, Górażdże Heidelberg Cement Group and Lafarge. They compared the extent to which and the form in which non-financial data are is presented. It was presented and included which of the mentioned companies take into account the full value chain in the reporting process, from mining operations to processing and sale products, into account.

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Authors and Affiliations

Justyna Woźniak
Katarzyna Pactwa
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Abstract

The debate between Ludwik Fleck (microbiologist and philosopher of science) and Tadeusz Bilikiewicz (historian and philosopher of medicine) took place shortly before the outbreak of World War II and remained virtually unnoticed until 1978. A wider recognition of their exchange was possible only after the English and German translations appeared. Basically, the polemics concerned understanding of the concept of style and influence that the environment exerted on scientific activity and its products. The polemic started with the review of Bilikiewicz’s book Die Embryologie im Zeitalter des Barock und des Rokoko (1932) where the historical account of the development of embryology in the early and late Baroque period was interwoven with bold sociological remarks. The commentators of the debate were quick to notice that the claims made by Fleck at that time were crucial for understanding of his position, especially because they let to interpret his views in a non-relativist way. While the importance of the controversy was univocally acknowledged, its assessment so far has been defective for two reasons. First, for decades the views of Bilikiewicz were known only from the short and rather critical presentation given by Fleck and this put their discussion into an inadequate perspective. Second, for over 40 years it remained a complete puzzle what prompted their exchange of views. This paper closes these gaps. Thus, on the one hand, I reconstruct the central issue of the disputation between Fleck and Bilikiewicz and situate it within the context of Bilikiewicz’s views. On the other hand – and this is more important – I try to explain the origin of their debate by quoting some recently discovered and unpublished archival materials. A review of their correspondence gives me an opportunity to advance some hypotheses about the aims and hopes connected with their project but also possible reasons for its failure.

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Authors and Affiliations

Artur Koterski

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