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Abstract

According to the most popular conceptualization of materialism by Richins and Dawson it consists of three components: acquisition centrality, acquisition as the pursuit of happiness and possession -defined success. They are usually combined and an overall indicator of materialism is used commonly in various studies. In the article the three components are examined separately. Differences in their nature are revealed in a theoretical analysis, whereas in two empirical studies the ways they connect with well -being are presented. The results show that the overall materialism explains much less variance of well -being than the three components taken separately. Of the three the possession-defined happiness is the most detrimental to all aspects of well -being. The possession -defined success does not connect with well -being at all. Finally, acquisition centrality elevates hedonic and psychological well -being. The conclusion is that the modest effect of materialism on well -being, usually identified in various studies, is probably at least partly due to conflicting forces existing within the construct.

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Authors and Affiliations

Małgorzata Ewa Górnik-Durose
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Abstract

Once flourishing in the early medieval India, the materialist Carvaka/Lokayata tradition of philosophy vanished centuries ago leaving mere bits from their foundational sutra, and from a few commentaries thereon. These are scattered in the works of their opponents, hence the winding path to reconstructing the Carvaka/Lokayata thought necessarily begins with evaluating the reliability of the source material. This paper deals with the problem of the brief account of two interpretations of the Carvaka/Lokayata aphorism: 'from these, consciousness', recorded by the 8th-century Buddhist authors Śantarak�ita and Kamalaśfla in the Lokâyata-parfk$a Chapter XXII of the Tattva-sańgraha(-pañjika), critically edited by the author of the present paper.

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Authors and Affiliations

Stanisław Jan Kania
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Abstract

State-of-the-art techniques for growing crystals are yielding materials with unique properties – such as metamaterial behavior or plasmon-enhanced optical performance.
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Authors and Affiliations

Piotr Piotrowski
1

  1. ENSEMBLE Centre of Excellence in WarsawUniversity of Warsaw
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Abstract

The paper contains a short literature review on the subject of special type of thin film structures with resistiveswitching memory effect. In the literature, such structures are commonly labeled as "memristors". The word "memristor" originates from two words: "memory" and "resistor". For the first time, the memristor was theoretically described in 1971 by Leon Chua as the 4th fundamental passive electronics element with a non-linear current-voltage behavior. The reported area of potential usage of memristor is enormous. It is predicted that the memristor could find application, for example in the domain of nonvolatile random access memory, flash memory, neuromorphic systems and so forth. However, in spite of the fact that plenty of papers have been published in the subject literature to date, the memristor still behaves as a "mysterious" electronic element. It seems that, one of the important reasons that such structures are not yet in practical use, is unsufficient knowledge of physical phenomena determining occurrence of the switching effect. The present paper contains a literature review of available descriptions of theoretical basis of the memristor structures, used materials, structure configurations and discussion about future prospects and limitations.

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Authors and Affiliations

Jarosław Domaradzki
Damian Wojcieszak
Tomasz Kotwica
Ewa Mańkowska
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Abstract

The goal of this study is to develop a method of manufacturing porous ceramic skeletons used as semi-finished products for reinforcement of composite materials or as filters. For manufacturing skeletons, only waste materials from coal combustion (fly ashes and bottom slags) as well as rubber granules from used tires and car parts were used. These granules were a pore-forming agent that underwent thermal degradation during sintering process. The influence of sintering temperature, portion, and type of rubber granules on the porosity of developed ceramic skeletons was determined. The study of structure of base materials and the developed ceramic skeletons in a scanning electron microscope as well as their X-ray phase analysis were made. Results will allow to predict phases that can be formed on the metal-reinforcement interface during pressure infiltration.
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Authors and Affiliations

M. Krezmer
1
ORCID: ORCID

  1. Silesian University of Technology, Faculty of Mechanical Engineering, Scientific and Didactic Laboratory of Nanotechnology and Materials Technologies , Krasińskiego Str., 44-100 Gliwice, Poland
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Abstract

The paper presents results of research on steel castings GX120Mn13 (L120G13 by PN-89/H-83160), zone-reinforced by elektrocorundum particles (Al2O3), with a grain size from 2 to 3.5 mm. Studies revealed continuity at interface between composite components and formation of a diffusion zone in the surface layer of electrocorundum grains. In the area of this zone, simple manganese segregation and reverse iron and chromium segregation were found. The transfer of these elements from cast steel to electrocorundum grains resulted superficial depletion in aluminum and oxygen in this area. No porosity was observed at the interface between two components of the composite. We found it very beneficial from an exploitation point of view, as confirmed by the study of resistance to abrasive wear.
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Bibliography

[1] Matthews, F.L., Rawlings, R.D. (1999). Composite Materials. Engineering and Science. CRC Press: Boca Raton, FL, USA.
[2] Kocich, R., Kunčická, L., Král, P. & Strunz, P. (2018). Characterization of innovative rotary swaged Cu-Al clad composite wire conductors. Materials Design. 160, 828-835. Materials 2020. 13, 4161, p. 13 of 15.
[3] Kunčická, L., Kocich, R., Dvořák, K. & Macháčková, A. (2019). Rotary swaged laminated Cu-Al composites. Effect of structure on residual stress and mechanical and electric properties. Materials Science Engineering A. 742, 743-750.
[4] Kunčická, L., Kocich, R. (2018) Deformation behaviour of Cu-Al clad composites produced by rotary swaging. IOP Conf. Ser. Mater. Sci. Eng. 369, Kitakyushu City, Japan.
[5] Clyne, T.W., Withers, P.J. (1993) An Introduction to Metal Matrix Composites. Cambridge University Press: New York, NY, USA.
[6] Tjong, S. & Ma, Z. (2000). Microstructural and mechanical characteristics of in situ metal matrix composites. Materials Science Engineering R: Reports 29, 49-113.
[7] Górny, Z., Sobczak, J. (2005). Modern casting materials based on non-ferrous metals. Krakow. Ed. ZA-PIS.
[8] Sobczak, J. & Sobczak, N. (2001). Pressure infiltration of porous fibrous structures with aluminum and magnesium alloys. Composites. 1(2), 155-158.
[9] Klomp, J. (1987). Fundamentals of diffusion bonding. Amsterdam Ed. Ishida, Elsevier Science Publishers, 3-24.
[10] Kaczmar, J., Janus, A., Samsonowicz, Z. (1997). Influence of technological parameters on production of selected machine parts reinforced with ceramic fibers. Reports of Institute of Machine Technology and Automation of Wrocław University of Science and Technology. SPR No 5.
[11] Kaczmar, J., Janus, A., Kurzawa, A. (2002). Development of basics technology of manufacturing machine and device parts from aluminum composites reinforced with zones of ceramic particles. Reports of Institute of Machine Technology and Automation of Wrocław University of Science and Technology. SPR No 11.
[12] Dmitruk, A.G., Naplocha, K., Żak, A. M., Strojny-Nędza, A., Dieringa, H. & Kainer, K. (2019). Development of pore-free Ti-Si-C MAX/Al-Si composite materials manufactured by squeeze casting infiltration. Journal of Materials Engineering and Performance. 28(10), 6248-6257.
[13] Maj, J., Basista, M., Węglewski, W., Bochenek, K., Strojny-Nędza, A., Naplocha, K., Panzner, T., Tatarková, M., Fiori, F. (2018). Effect of microstructure on mechanical properties and residual stresses in interpenetrating aluminum-alumina composites fabricated by squeeze casting. Materials Science and Engineering. A, Structural Materials: Properties, Microstructure and Processing. 715,154-162.
[14] Szajnar, J., Wróbel, P., Wróbel, T. (2008). Model castings with composite surface layer - application. Archive of Foudry Enginnering. 8(3), 105-110.
[15] Gawroński, J., Szajnar, J., Wróbel, P. (2005). Surface composite layers of cast iron - ceramic particles. Archive of Foundry. 5(17), 107-114.
[16] Marcinkowska, J. (1986). Wear-resistant casting coatings on cast steel. Solidification of Metals and Alloys. 6, 37-42.
[17] Baron, Cz., Gawroński, J. (2006). Abrasive wear resistance of sandwich composites based on iron alloys. Composites. 6(3), 45-49.
[18] Operation and maintenance documentation of test stand T-07.
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Authors and Affiliations

Daniel Medyński
ORCID: ORCID
A.J. Janus
1

  1. Witelon State University of Applied Science in Legnica ul. Sejmowa 5A, 59 – 220 Legnica, Poland
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Abstract

The paper presents the novel concept of the magnetoelectric sensor constructed using the amorphous glass ribbon. Its output characteristics (voltage pattern), conditions of work and experimental results are presented. The novel construction allows for minimizing the demagnetizing field in the core of the sensor and linearization of the characteristics between the magnetic field and obtained voltage. Conducted experiments were aimed at determining the sensor operation in the presence of the constant magnetic field (HDC). The main concern of the tests was to verify the linear dependency between the HDC value and the amplitude of the output voltage. Next, the computer model representing the sensor behavior in the constant magnetic field is described. The model implements the parameter identification task based on the regression algorithms. The presented work shows that the proposed device can be used to measure the weak magnetic field and the dependency between the output signal amplitudes and the constant component in the measured magnetic field is approximately linear. This enables measurements of even weak fields.
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Authors and Affiliations

Karol Kuczynski
1
ORCID: ORCID
Piotr Bilski
1
ORCID: ORCID
Adrian Bilski
2
ORCID: ORCID
Jerzy Szymanski
3
ORCID: ORCID

  1. Warsaw University of Technology, Faculty of Electronics and Information Technology, Institute of Radioelectronics and Multimedia Technology, Poland
  2. Warsaw University of Life Sciences, Poland
  3. Kazimierz Pulaski University of Technology and Humanities in Radom, Faculty of Transport, Electrical Engineering and Computer Science, Poland
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Abstract

A great number of non-functional child care facilities for children up to the age of three have been created in Poland to this day. This state of affairs may be the consequence of the low level of knowledge in this field, as well as few available studies on topics associated with nursery facilities, which may familiarise readers with the legal aspects, administrative procedures, or examples of good functional and material solutions of such units. What is more, there is also little information about the needs and preferences of people directly related to the topic. The aim of the article is to analyse the expectations and preferences of nursery facilities’ users in terms of the functional and material solutions. Based on a survey conducted among the nurseries’ employees and parents placing their children in the care of such institutions, a number of guidelines has been defined, allowing for the design of an optimal nursery facility that would meet the market’s expectations.

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Authors and Affiliations

E. Radziszewska-Zielina
W. Grabowska
B. Szewczyk
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Abstract

The analysis of the costs and emissions of greenhouse gases for individual phases of construction investments allows for the implementation of solutions and the prevention of negative environmental impacts without significantly increasing construction costs. The share of individual investment phases in the amount of carbon dioxide (CO2) produced for the construction and use of buildings depends mainly on the materials used and the implemented design solutions. In accordance with the idea of sustainable construction, materials and design solutions with the lowest possible carbon footprint should be used. This can be achieved by using natural building materials, materials subjected to appropriate chemical composition modifications, or materials in which their production does not require large amounts of energy. The aim of the article is to determine the value of the purchase costs of selected road materials (concrete paving blocks, cement-sand bedding, concrete curbs, semi-dry concrete and concrete underlay, washed sand, and crushed aggregate with a fraction of 0–31.5 mm) for the implementation of a road investment. In addition, the authors focused on determining the size of the embodied carbon footprint due to GHG (greenhouse gas) emissions and GHG removals in a product system, expressed as CO2 equivalents for the same materials that were subjected to cost analyzes. The article presents the results of original analyzes, and indicates the optimal solutions in terms of minimizing the cost of purchasing road materials and minimizing the carbon footprint. The discussion also covers the issue of changing the chemical composition in the context of the potential impact on the reduction of material costs and CO2 equivalent emissions.
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Authors and Affiliations

Damian Wieczorek
1
ORCID: ORCID
Krzysztof Zima
1
ORCID: ORCID

  1. Cracow University of Technology, Faculty of Civil Engineering, Warszawska 24, 31-155 Kraków, Poland
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Abstract

In this work, the author implements concepts and methods of analysis of nonlinear elasticity theory in a simplified description of elastic-plastic properties of materials. Taking the principle of conservation of energy as the theoretical basis, the author formulates a criterion that makes it possible to examine the stability of internal equilibrium in deformed material whose nonlinear properties are defined by strain energy density function. The formulae allowing for assessment of complex states of strain in the aspect of material strength were derived on the assumption of small deformation. These formulae can replace mathematical relationships traditionally known as strength hypotheses. The example included in the paper presents the method of determining, in the space of strain state components, the areas where permanent deformation or destruction of material is possible because of strain state stability. Characteristic parameters used in the example are obtained in a static tensile test on specimen 01· constructional carbon steel of ordinary grade. The results of the analysis, based on the formulated strength hypothesis on stability of strain state, are compared with those resulting from the Huber's hypothesis on energy of non-dilatational strain.
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Authors and Affiliations

Tadeusz Michał Wegner
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Abstract

The present article investigates theoretically the refection and transmission through a lossless dielectric slab embedded between two semi−infinite left−handed materials (LHMs) in which the electric permittivity and magnetic permeability are simultaneously negative. The LHM is assumed to be dispersive according to Lorentz as well as Drude medium model. The reflection and transmission coefficients are studied with the angle of incidence, frequency and slab thickness. The effect of the damping frequency is also investigated. It is found that the damping frequency has an insignificant effect on reflected, transmitted and loss powers. Band pass filter is one of the possible applications of the proposed structure.

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Authors and Affiliations

S.A. Taya
D.M. El-Amassi
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Abstract

The paper presents brown coal as one of the two basic domestic energy raw materials apart from hard coal. Historically, the use of brown coal in Poland is primarily fuel for the power plants. It was used for the production of lignite briquettes in small quantities and as fuel for local boiler houses and as an addition to the production of fertilizers (Konin and Sieniawa). At present, after changes in the case of the quality of fuels used in local boiler plants, brown coal remains as a fuel for the power plants in almost 100%. Currently, the brown coal industry produces about 35% of the cheapest electricity. The cost of electricity production is more than 30% lower than the second basic fuel – hard coal. The existing fuel and energy complexes using brown coal, with the Bełchatów complex at the forefront, are now an important guarantor of Poland’s energy security. In contrast to the other fuels such as: oil, natural gas or hard coal, the cost of electricity production from brown coal is predictable in the long term and almost insensitive to fluctuations in global commodity and currency markets. Its exploitation is carried out using the high technological solutions and respecting all environmental protection requirements, both in the area of coal extraction and electricity generation. Importantly, the fuel and energy complexes using brown coal showed a positive profitability so far and generated surpluses enabling the financing of maintenance and development investments, also in other energy segments. In particular, the sector did not require and has yet not benefited from public aid in the form of, for example, subsidies or tax concessions. Polish brown coal mining has all the attributes necessary for long-term development to ensure the country’s energy security. The document which is a road map for the brown coal industry is the Program for the Brown Coal Mining Sector in Poland adopted by the Council of Ministers on May 30, 2018. The Program covers the years 2018–2030 with a perspective up to 2050 and presents the development directions of the brown coal mining sector in Poland together with the objectives and actions necessary to achieve them. The Program presents a strategy for the development of brown coal mining in Poland in the first half of the 21st century. Possible scenarios have developed in active mining and energy basins as well as in new regions with significant resources of this mineral. This is to enable the most efficient use of deposits in the Złoczew and Konin regions as well as the Gubin and Legnica brown coal basins, and then deposits located in the Rawicz region (Oczkowice) as well as other prospective areas that may eventually replace the existing active mining and energy areas. This will allow power plants to continue to produce inexpensive and clean electricity, using the latest global solutions in the field of clean coal technologies.

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Authors and Affiliations

Zbigniew Kasztelewicz
Miranda Ptak
Mateusz Sikora
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Abstract

The Legnica deposit is one of the most prospective in the context of future lignite mining. Its extraction will be inseparable from the removal of the rocks of the overburden, the volume of which is very large. Due to the raw material properties, some of the rocks can be classified as accompanying minerals. The raw material identification of overburden sediments in the Legnica lignite deposit is insufficient. So far, they haven’t been the subject of detailed and comprehensive research to prove their usefulness. The article was a summary of the knowledge on this subject. The following should be included in the accompanying minerals: Quaternary sands and gravels, tertiary sands and clays (Poznan clays). They are present in two colour variants in the Legnica deposit - and fiery. The mineral composition of greenish-blue clays allows them to be included in illite-kaolinite- smectite varieties, in turn fiery clays as kaolinite-illite-smectite varieties. The tertiary clays are a very useful raw material for the production of building materials. In addition, they are potential mineral sorbents due to the nature of the association of clay minerals (occurrence of montmorillonite). They also show suitability for building waterproofing barriers. Quaternary gravels and sands, developed in the overburden Legnica deposit are differentiated raw materials. Some of them are raw materials for the construction industry. The glacial tills can be used as a component of ceramic mixtures. Tertiary sands can be used as a proppant material. The information on the raw material properties of these sediments will be one of the essential criteria for their treatment as accompanying minerals. Minerals accompanying those developed in the Legnica deposit should be exploited and deposited selectively. The creation of anthropogenic deposits accumulating these minerals will provide the possibility of their use for decades after the termination of operation.

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Authors and Affiliations

Tadeusz Ratajczak
Elżbieta Hycnar
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Abstract

As of the spring of 2017, the HAŁDY Database is available on the Polish Geological Institute – NRI website. The geodatabase contains information and data on waste mineral raw materials collected on old heaps, industrial waste stock-piles and in post-mining settlers, from the Polish part of the Sudety Mountains. The article presents the types of data and information contained in the geodatabase and the methodology for their collection. As a result of four-year research works, field reconnaissance, archives and geological basic research, 445 objects of former mining and mineral processing were inventoried. There are 403 mine heaps, 16 industrial settlers, 23 stock-piles and 3 external dumps. These are mainly objects after coal mining and metal ores, including post-uranium. The greatest opportunities for the economic use of waste are associated with coal sludge accumulated in settlers of the liquidated Lower Silesian Coal Basin. The material from stone heaps after polymetallic, iron and fluorite ore mining is also easy to use. The issue of the economic use of post-flotation copper ore waste or the recovery of metals (including gold) from dumps of arsenic mining remains open. The limitation here is the efficiency of metal recovery technologies and environmental restrictions. Some of the objects are located in protected areas, which excludes the possibility of waste management. Some stock-piles and heaps should be carefully reclaimed and covered by environmental monitoring, due to their harmful impact on environmental components.

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Authors and Affiliations

Cezary Sroga
Stanisław Z. Mikulski
Wojciech Bobiński
Marek Adamski
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Abstract

The first Mineral Policy in Poland was prepared in 1938. In that time The Mineral Policy was primarily dedicated to preparing Poland for a defensive war. The Central Geology Authority (CGA) was created in 1991. The main task of this Authority was preparation plans (annual and multiannual) of geological-exploration. The CGA’s activities were focused on enhancing the resource base of mineral deposits. As of 1985 the coordination of geological tasks is the main duty of the Chief Geologist of the country. In 1996 the Council of Ministers adopted a document called State policy in the field of mineral resources, prepared at the Ministry of Environmental Protection, Natural Resources and Forestry as well as the Ministry of Industry and Trade. In 2015 a wide public discussion about the need to develop a mineral raw materials policy, initiated by the publication of three analytical documents prepared by the Demos Foundation, Professor J. Hausner and the Ministry of the Environment took place. Milestones in the development of a national mineral raw materials policy was the establishment of the special government’s plenipotentiary as well as the inter-ministerial team for mineral raw materials policy. In 2018, The Mineral Raw Materials Policy was transferred for public consultation. This document is the first document that is so comprehensive and holistic from the point of view of national mineral security interests. The Mineral Raw Materials Policy is based on 9 substantial pillars among them: economical and legal basis of mineral sector activities, investment risk, geological prospection and exploration, utilization of mineral wastes.

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Authors and Affiliations

Krzysztof Szamałek
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Abstract

The authors established the chemical and phase compositions of grain fractions of the magnesia carbon scrap disintegrated using industrial cone crushers. The investigations included chemical and XRD analyses and optical investigations. The contents of admixtures: SiO2, CaO, Fe2O3 and Al2O3 increase with the decreasing size of the scrap grain fractions, whereas the C/S ratio decreases in finer and finer fractions due to changes of the phase composition. These relations are caused by the presence of low-fusible silicate phases, characterized by their cleavage and brittleness. Such phases were mainly derived from the graphite ash containing a high silica content. The scrap after removing its finest grain fractions can be recycled and utilized for producing the magnesia-carbon refractory materials. However, the finest grain fractions may be used, e.g. as a component of gunite mixes. Many years of experience collected by the ArcelorMittal Refractories Ltd., Krakow, Poland in the field of refractory scrap utilization has also been presented.

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Authors and Affiliations

Czesław Goławski
Andrzej Kielski
Lucyna Obszyńska
Piotr Wyszomirski
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Abstract

Building a Strategic Battery Value Chain in Europe COM/2019/176 is a priority for EU policy. Europe’s current share of global cell production is only 3%, while Asia has already reached 85%. To ensure a competitive position and independence in the battery market, Europe must act quickly and comprehensively in the field of innovation, research and construction of the infrastructure needed for large-scale battery production. The recycling of used batteries can have a significant role in ensuring EU access to raw materials. In the coming years, a very rapid development of the battery and rechargable battery market is forecast throughout the EU. In the above context, the recycling of used batteries plays an important role not only because of their harmful content and environmental impact, or adverse impact on human health and life, but also the ability to recover many valuable secondary raw materials and combine them in the battery life cycle (Horizon 2010 Work Programme 2018–2020 (European Commission Decision C(2019) 4575 of 2 July 2019)). In Poland, more than 80% of used batteries are disposable batteries, which, together with municipal waste, end up in a landfill and pose a significant threat to the environment. This paper examines scenarios and directions for development of the battery recycling market in Poland based on the analysis of sources of financing, innovations as well as economic and legal changes across the EU and Poland concerning recycling of different types of batteries and rechargable batteries.

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Authors and Affiliations

Agnieszka Nowaczek
ORCID: ORCID
Joanna Kulczycka
ORCID: ORCID
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Abstract

Modern technologies have been revolutionizing industries for years, providing competitive advantages to companies. As a technology based on decentralization, Blockchain becomes a tool to support and secure processes and transactions in industries such as mining and power engineering. It also supports supply chain processes, which are particularly important in today's mining business. The use of advanced cryptography methods results in increased cyber security in entities that implement such solutions. The use of Blockchain technology carries a strong message, both to competitors and customers, about intensifying work on authentication and process traceability. This publication focuses on defining the trust gap problem in the mining industry and on examples of the use of technology in data traceability processes. The mining industry is beginning to use technologies which had been previously available only in the theoretical realm. The ongoing development towards a smart industry entails a number of studies and expert assessments, aimed to integrate knowledge from the mining and IT areas. The combination of these research areas leads to an increase in the value of both the companies implementing modern technologies and traditional companies that implement such applications in their value chain. Based on the analyzed articles, two main areas of consideration in the context of the extractive industry were distinguished: systems that track and secure the flow of data in specific mining processes and systems that monitor and secure information on processes which support the raw materials supply chain.
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Authors and Affiliations

Tomasz Leśniak
1
ORCID: ORCID
Arkadiusz Jacek Kustra
1
ORCID: ORCID
Elżbieta Królikowska
2

  1. AGH University of Science and Technology, Kraków, Poland
  2. Jastrzębska Spółka Węglowa S.A., Jastrzębie-Zdroje, Poland
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Abstract

The paper is of practical importance and describes the construction of a test rig and the measurement method for determining the relative emissivity coefficient of thermosensitive thin polymer coatings. Polymers are high-molecular chemical compounds that produce chains of repeating elements called ‘mers’. The polymers can be natural and artificial. The former ones form the building material for living organisms, the latter – for plastics. In this work, the words plastics and polymers are used as synonyms. Some plastics are thermosensitive materials with specific physical and chemical properties. The calorimetric method mentioned in the title consists of two steps. The first stage, described here, involves very accurately measuring the emissivity of black paint with the highest possible relative emissivity coefficient, which covers the surface of the heater and the inner surface of the chamber. In the second step, the thermosensitive polymer will be placed on the inner surface of the chamber, while black paint with a known emissivity coefficient will remain on the heater. Such a way of determining the properties of thermosensitive polymers will increase the error of the method itself, but at the same time will avoid melting of the polymer coating. During the tests, the results of which are presented in this work, the emissivity coefficient of the black paint was obtained in the range of 0.958–0.965.
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Authors and Affiliations

Ewa Pelińska-Olko
1

  1. Wrocław University of Science and Technology, Faculty of Mechanical and Power Engineering, Department of Thermodynamics and Renewable Energy Sources, Wybrzeze Wyspianskiego 27, 50-370 Wrocław, Poland
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Abstract

The potential applications of loop heat pipes (LHPs) are the nuclear power space systems, fuel cell thermal management systems, waste heat recovery systems, medium temperature electronic systems, medium temperature military systems, among others. Such applications usually operate in temperature ranges between 500–700 K, hence it is necessary to develop an LHP system that will meet this requirement. Such a thermal management device require to meet various technical problems and challenges currently existing in the development of LHP working in medium temperatures, including: (1) selection of appropriate working fluid; (2) selection of appropriate LHP construction material; (3) construction of suitable test rig capable of testing at elevated temperatures; (4) development of new testing methods. Currently, there are no proven working fluids that can be used in LHPs in medium temperature ranges. Water can be applicable only at temperatures up to 570 K. Caesium can be applicable at temperatures above 670 K. Organic fluids usually tend to generate non-condensable gasses and/or decompose at elevated temperatures and their viscosity dramatically increases. For halides, most of them are very reactive or toxic and their full property data are not available or the majority of the physical properties are predicted, also live tests and their environmental impact data are not adequate. As for casing/LHP construction material, there are no full chemical compatibility tables with most of the medium temperature working fluids and the reactivity of fluids significantly limits the potential materials. Also, testing such an LHP is an endeavour as the reactivity of medium temperature fluids and the use of obscure metals create new challenges. Altogether creates multiple challenges in the development, testing, handling and operating of LHP in the medium temperature range.
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Bibliography

[1] Zohuri B.: Heat Pipe Design and Technology. Modern Applications for Practical Thermal Management (2nd Edn.). Springer, 2016.
[2] Zhang Y. (Ed.): Heat Pipes: Design, Applications and Technology. Nova, 2018.
[3] Anderson W.G., Bland J.J., Fershtater Y., Goncharov K.A., Nikitkin M., Juhasz A.: High-temperature loop heat pipes. IECEC AP-18, ASME 1995.
[4] Anderson W.G., Rosenfeld J.H., Angirasa D., Mi Y.: Evaluation of heat pipe working fluids in the temperature range 450 to 700 K. AIP Conf. Proc. 699(2004), 20.
[5] Anderson W.G., Bienert W.: Loop heat pipe radiator trade study for the 300– 550 K temperature range. AIP Conf. Proc. 746(2005), 946.
[6] Anderson W.G.: Intermediate temperature fluids for heat pipes and loop heat pipes. In: Proc. 5th Int. Energy Conversion Engineering Conf. Exhib. (IECEC), 25–27 June 2007, AIAA 2007–4836.
[7] Faghri A., Buchko M., Cao Y.: A study of high-temperature heat pipes with multiple heat sources and sinks: Part I – Experimental methodology and frozen startup profiles. J. Heat Transf. 113(1991), 4, 1003–1009.
[8] Faghri A., Buchko M., Cao Y.: A study of high-temperature heat pipes with multiple heat sources and sinks: Part II – Analysis of continuum transient and steadystate experimental data with numerical predictions. J. Heat Transf. 113(1991), 4, 1010–1016.
[9] https://www.1-act.com/merit-number-and-fluid-selection/ (accessed 10 Sept. 2021).
[10] NIST Reference Fluid Thermodynamic and Transport Properties Database (REFPROP), Version 10. https://www.nist.gov/srd/refprop/ (accessed 10 Sept. 2021).
[11] Blauciak K., Szymanski P., Mikielewicz D.: The influence of loop heat pipe evaporator porous structure parameters and charge on its effectiveness for ethanol and water as working fluids. Materials 14(2021), 7029.
[12] Nikitkin M.N., Bienert W.B., Goncharov K.A.: Non condensable gases and loop heat pipe operation. SAE Tech. Pap. 981584. In: Proc. 28th Int. Conf. on Environmental Systems, 1998.
[13] Wrenn K.R., Wolf D., Kroliczek E.J.: Effect of non-condensible gas and evaporator mass on loop heat pipe performance. SAE Tech. Pap. 2000-01-2409. In: Proc. 30th Int. Conf. on Environmental Systems, 603–614, 2000.
[14] Ishikawa H., Ogushi T., Nomura T., Noda H., Kawasaki H., Yabe T.: Heat transfer characteristics of a reservoir embedded loop heat pipe (2nd report, influence of noncondensable gas on heat transfer characteristics). Heat Transf. Asian Res. 36(2007), 8, 459–473.
[15] Singh R., Akbarzadeh A., Mochizuki M.: Operational characteristics of the miniature loop heat pipe with non-condensable gases. Int. J. Heat Mass Tran. 53(2010), 17–18, 3471–3482.
[16] He J., Lin G., Bai L., Miao J., Zhang H.: Effect of non-condensable gas on the operation of a loop heat pipe. Int. J. Heat Mass Tran. 70(2014), 449–462.
[17] Prado-Montes P.: Development of an elevated temperature loop heat pipe for space applications and investigation of non-condensable gas impact on its performance. PhD thesis, Polytechnic University of Madrid, Madrid 2014.
[18] Devarakonda A., Xiong D., Beach E.D.: Intermediate temperature water heat pipe tests. AIP Conf. Proc. 746(2005), 158.
[19] Mishkinis D., Prado P., Sanz R., Radkov A., Torres A., Tjiptajardja T.: Loop heat pipe working fluids for intermediate temperature range: from –40°C to +125°C. In: Proc. 1st. Int. Conf. on Heat Pipes for Space Applications, Moscow, Sept. 2009.
[20] Mikielewicz D, Błauciak K.: Investigation of the influence of capilary effect on operation of the loop heat pipe. Arch. Thermodyn. 35(2014), 3, 59–80.
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Authors and Affiliations

Paweł Szymański
1
Dariusz Mikielewicz
1

  1. Gdansk University of Technology, Faculty of Mechanical Engineering and Ship Technology, Narutowicza 11/12,80-233 Gdansk, Poland
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Abstract

The emission rate of fibers released lrorn the new/fresh and used/worn ceramic fiber material. glass wool and man-made mineral fiber material due lo mechanical impact was determined experimentally. The emission rate has been defined as a number or fibers emitted per unit mass and unit impaction energy. The averaged emission rate of short fibers (LS 5 run) for all studied fresh non-asbestos fiber materials ranged lrom 2.2 to 20 fibers/(g·.l), while the emission or long fibers (I,> 5 urn) was between 2.2 and I 00 fibers/(g·J). The susceptibility or worn fiber-containing materials 10 emitting fibrous particles due 10 mechanical impaction was significantly diverse. Emission from glass wool unchanged with the exploitation, while the emission rate of the mineral fiber material increased by a factor of I O·' compared 10 new material. The dominating population or emitted fibers from studied materials ranged trorn 2 10 around 8 pm in length.
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Authors and Affiliations

Józef S. Pastuszka
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Abstract

Processes applied for preliminary treatment of wastewater from refineries and petrochemical plants create the oily sludge, containing high percentage of water and only a bit less of hydrocarbons. This sludge is collected in storage tanks, because no application for it can be found. Our researches had as a first step the aim to convert this fluid sludge into solid substance (product) by adding of quicklime and then utilize the product in the road construction as a bottom layer of the road. The product should be added in the amount of a few percent comparing to the rest of soil. The second step of the research was an assessment of an impact of the product used for construction of experimental sections of roads and squares on environment by monitoring of surface and ground water quality in their vicinity. If the contribution of the product in total amount of the road material is less than 8% the influence is kept under limits.
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Authors and Affiliations

Bronisław Bartkiewicz
Iwona Obierak
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Abstract

Obtaining a pure product by mixing together raw materials, so as to carry out a chemical reaction at high selectivity, is a difficult part of manufacturing chemical products. How can we test reactors and mixers to ensure the efficient use of energy?

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Authors and Affiliations

Magdalena Jasińska
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Abstract

Magnetic properties of silicon iron electrical steel are determined by using standardized measurement setups and distinct excitation parameters. Characteristic values for magnetic loss and magnetization are used to select the most appropriate material for its application. This approach is not sufficient, because of the complex material behavior inside electrical machines, which can result in possible discrepancies between estimated and actual machine behavior. The materials’ anisotropy can be one of the problems why simulation and measurement are not in good accordance.With the help of a rotational single sheet tester, the magnetic material can be tested under application relevant field distribution. Thereby, additional effects of hysteresis and anisotropy can be characterized for detailed modelling and simulation.

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Authors and Affiliations

Gregor Bavendiek
Nora Leuning
ORCID: ORCID
Fabian Müller
Benedikt Schauerte
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Andreas Thul
Kay Hameyer
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