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Number of results: 6
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Abstract

Ozjawiskach zachodzących w internecie i interakcjach między jego użytkownikami opowiada prof. dr hab. Dariusz Jemielniak, wiceprezes Polskiej Akademii Nauk.
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Authors and Affiliations

Dariusz Jemielniak
1

  1. wiceprezes Polskiej Akademii Nauk
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Abstract

Flame retardants (FRs) that have an adverse effect on human and the environment have been subject to regulation since 1972. However, FRs emerging as a replacement, are not proving to be fully environmentally safe. Water and sediment contamination by FRs, including organophosphorus (OPFRs) and novel brominated (NBFRs) ones, is a matter of major concern. Due to their common usage, many release sources, and relatively high mobility, they pose a threat to aquatic organisms and ecosystems. This review summarises studies on the OPFRs’, and NBFRs’ simultaneous occurrence in water and corresponding sediment. The main sources of occurrence and routes of entry of FRs into the environment are presented. The newest reports on the ecotoxicity of selected FRs had been summarised in order to bring the matter to attention. The research revealed that although great efforts had been made to study the occurrence of OPFRs and NBFRs in water and sediment separately, there is a lack of research on their occurrence in both media in the same area. Although major efforts have been made to study the ecotoxicity of OPFRs, there are some deficiencies for the NBFRs. Considering their relatively high ecotoxicity, further studies should be conducted on joint ecotoxicity, which may cause synergistic or antagonistic effects.
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Authors and Affiliations

Adriana M. Dowbysz
1
ORCID: ORCID
Mariola Samsonowicz
1
ORCID: ORCID
Bożena Kukfisz
2
ORCID: ORCID

  1. Bialystok University of Technology, Department of Chemistry, Biology and Biotechnology, 45E Wiejska St, 15-351, Bialystok, Poland
  2. Fire University, Institute of Safety Engineering, Warsaw, Poland
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Abstract

Dielectric properties of a nematic liquid crystal (NLC) mixture ZhK-1282 were investigated in the frequency range of 102–106 Hz and a temperature range of −20 to 80°С. On the basis of the Debye’s relaxation polarization model dielectric spectra of temperature dependence of the orientational relaxation time τ and the dielectric strength δe were numerically approximated at the parallel orientation of a molecular director relative to alternating electric field. Influence of ester components in the mixture plays crucial role in relaxation processes at low temperature and external field frequency. The activation energy of the relaxation process of a rotation of molecules around their short axis was measured in a temperature interval of −20 to  +15°С in which the dispersion of a longitudinal component of the dielectric constant takes place. The energy of potential barrier for polar molecules rotation in the mesophase was calculated. The value of the transition entropy from the nematic to isotropic phase was obtained from this calculation. The values of the coefficient of molecular friction and rotational diffusion were obtained by different methods. The experimental data obtained are in a satisfactory agreement with the existing theoretical models.

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Authors and Affiliations

D.N. Chausov
А.D. Kurilov
V.V. Belyaev
S. Kumar
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Abstract

The article presents the most significant material defects found in pistons for internal combustion engines, along with a graphical method of categorization using a Pareto-Lorenz chart. For the top three defects (constituting approximately 80% of all issues), a slightly different Ishikawa chart was employed to identify the causes behind their occurrence. Remedial actions were proposed, to be implemented primarily within the interoperative quality control of piston casting. It was concluded that it is crucial to prevent the excessive iron content in the alloy used for alfin inserts (AS9 alloy), particularly for cast iron ring carriers. The research was conducted in collaboration with Federal-Mogul company in Gorzyce (F-MG), one of the largest piston foundries in Poland.
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Bibliography


[1] Hines, P. (2003). Direction – Lean organization. Trans. Czerska J., Ed. Lean Q Centrum, Gdańsk. (in Polish).

[2] Pawłowski, E., Pawłowski, K., Trzcieliński, S. (2010). Lean Manufacturing methods and tools. Edition University of Technology, Poznań. (in Polish).

[3] Abdullah, F. (2003). Lean Manufacturing tools and techniques in the process industry. Dissertation. University of Pittsburgh, School of Engineering, USA.

[4] Zimniewicz, Z. (1999). Contemporary management concepts and methods. Warszawa: PWE. (in Polish).

[5] Walentynowicz, P. (2013). Determinants of the effectiveness of Lean Management implementation in manufacturing enterprises. Gdańsk: University of Gdańsk. (in Polish).

[6] Lipecki, J. (1998). Lean as method company restructuring. Economics and Organization of Enterprise 8, 12-15.

[7] Durlik, I. (2007). Management engineering. Warszawa: Placet. (in Polish).
[8] Hamrol, A. (2015). Strategies and practices for efficient operation: Lean, Six Sigma and others. Warszawa: PWN.

[9] Parkes, A. (2017). Cultural determinants of Lean Management. Warszawa: Difin. (in Polish).

[10] Janocha, M. (2016). Production process management in line with the concept of Lean Management in the automotive industry. Journal of Modern Management Process 1(2), 44-53.

[11] Womack, J.P., Jones, D.T., Roos, D. (2007). The Machine That Changed the World. Free Press A Division of Simon and Schuster Inc., New York, London, Toronto, Sydney.

[12] Czerska, J. (2014). Improving the value stream. Gdańsk: PWE. (in Polish).
[13] Piątkowski, J. & Czerepak, M. (2020). The crystallization of AlSi9 alloy designed for the alfin processing of ring supports in the engine pistons. Archives of Foundry Engineering. 20(2), 65-70. DOI:10.24425/afe.2020.131304.

[14] Piątkowski, J. & Krępa, A. (2023). Casting pistons for combustion engines from aluminum alloys over 50 years of experience Federal-Mogul Gorzyce. Foundry Journal. 73(3/4), 84-85. (in Polish).

[15] Piątkowski J., Czerepak M. (2023). Improving the quality of bimetalic connection between the ring insert and the engine piston. In METAL 2023: 32nd International Conference on Metallurgy and Materials, 17-19 May 2023 (40-41), Brno, Czech Republic. Ostrava: Tanger.

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Authors and Affiliations

J. Piątkowski
1
ORCID: ORCID
M Łent-Trepczyńska
A. Krępa
2
M. Ferdyn
3

  1. Faculty of Materials Engineering, Silesian University of Technology, Poland
  2. Federal-Mogul Gorzyce, Poland
  3. Magna Casting Kędzierzyn-Koźle, Poland
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Abstract

Kazimiera Szczuka talks about the late Prof. Maria Janion – a humanistic visionary, a revolutionary scholar of Romanticism, and a modest “maestra” in the eyes of her students.
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Authors and Affiliations

Kazimiera Szczuka
1

  1. Institute of Literary Research, Polish Academy of Sciences
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Abstract

Prof. Dariusz Jemielniak, Vice President of the Polish Academy of Sciences, discusses the dynamics of online communities and the study of digital interactions.
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Authors and Affiliations

Dariusz Jemielniak
1

  1. Vice President of the Polish Academy of Sciences

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