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Number of results: 9
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Abstract

In this study we look closely at the set of dorsal fricatives in Ukrainian with the purpose to explain their distributional peculiarities and phonological behavior. The analysis focuses on certain phonetic characteristics and the phonological represen-tation of the segments in question. Some other issues addressed in this study include the segmental strength which is calculated by the complexity of a segment and the presence of headed elements, the consonant-vowel interactions in which the segments in question participate and the impact of vowels on the distribution of back fricatives in Ukrainian. The main aim of this study is to propose and justify a particular phonological representation of the back fricatives in Ukrainian.

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Authors and Affiliations

Artur Kijak
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Abstract

The research was focused on the selection of the best conditions for the lactic acid production. As the organic source diluted waste whey was used. Two facultative anaerobic bacteria strains were examined: Lactobacillus rhamnosus and Lactococcus lactis. The neeed of anaerobic conditions as well as mineral supplementation of cultivationwere investigated. It turned out that the oxidationwas not the key parameter, but cultivationmediumneeded a supplementation for higher process efficiency. Finally, Lactobacillus rhamnosus strain was selected, for which LA production was app. 45% higher than for Lc. lactis. On the other hand, Lactobacillus rhamnosus was active at higher lactose concentration, thus waste whey needed to be less diluted. Additionally, high values of product/substrate yield coefficient make the process very efficient.

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Authors and Affiliations

Magdalena Lech
Anna Trusek
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Abstract

The results of microstructure examinations and hardness measurements carried out on two selected grades of high-manganese cast steel with an austenitic matrix, i.e. GX120Mn13 and GX120MnCr18-2, are presented. The examinations of the cast steel microstructure have revealed that the matrix of the GX120MnCr18-2 cast steel contains the precipitates of complex carbides enriched in Cr and Mn with two different morphologies. The presence of these precipitates leads to an increase in hardness by approx. 30 HB compared to the GX120Mn13 cast steel. Samples cut out from the tested materials were loaded (10 strokes) with an energy of 53 J, and then a ball-on-disc tribological test was performed. The test was carried out in reciprocating motion under technically dry friction conditions. While analyzing the obtained results of the microstructure, hardness, and abrasion tests, it was found that the presence of the hard carbide precipitates in the plastic matrix of the tested GX120MnCr18-2 cast steel promoted an increase in hardness, but also led to chipping of these particles from the alloy matrix, thus contributing to micro-cutting during friction.
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Bibliography

[1] Standard PN-EN 10349: 2009. Steel castings - Austenitic manganese steel castings.
[2] Banerjee, M.K. (2017). Heat Treatment of Commercial Steels for Engineering Applications. Comprehensive Materials Finishing. 2, 180-213.
[3] Dobrzański, L.A. (2002). Fundamentals of materials science and metal science. Warszawa: Wyd. Naukowo-Techniczne. ISBN: 83-204-2793-2. (in Polish).
[4] Baza materiałowa. Total materia. (June 2021). Retrieved August 13, 2021, from https://portal-1totalmateria1com 1000022kc0110.wbg2.bg.agh.edu.pl/search/quick/materials/1040932/material-description.
[5] Fedorko, G., Molnár, V., Pribulová, A., Futaš, P., Baricová, D. (2011). The influence of Ni and Cr-content on mechanical properties of Hadfield ́s steel. In 20th Anniversary International Conference on Metallurgy and Materials. Metal 2011, 18-20.05.2011 (pp.1-6). Brno, Czech Republic.
[6] Dastur, Y.N. & Leslie, W.C. (1981). Mechanism of work hardening in Hadfield manganese steel. Metallurgical Transactions A. 12A, 749-759.
[7] Austenitic Manganese Steels. (June 2021). Retrieved August 13, 2021, from http://www.keytometals.com/Articles/Art69.htm.
[8] Stradomski, Z. (2010). The role of microstructure in the wear behaviour of abrasion-resistant cast steels. Częstochowa: Wyd. Politechniki Częstochowskiej. ISBN: 978-83-7193-468-1. (in Polish).
[9] Kniaginin, G. (1977). Cast steel. Metallurgy and founding. Katowice: Wyd. Śląsk. (in Polish).
[10] Varela, L.B., Tressia, G., Masoumi, M., Bortoleto, E.M., Regattieri, C. & Sinatora, A. (2021). Roller crushers in iron mining, how does the degradation of Hadfield steel components occur. Engineering Failure Analysis. 122, 1-18.
[11] Głownia, J. (2002). Alloy steel castings – applications. Kraków: Wyd. FotoBit. ISBN: 83-917129-1-5. (in Polish).
[12] Kosturek, R., Maranda, A., Senderowski, C. & Zasada, D. (2016). Research into the application of explosive welding of metal sheets with Hadfield’s steel (Mangalloy). High-Energetic Materials. 8, 91-102.
[13] White, C.H. & Honeycombe, R.W.K. (1962). Structural changes during the deformation of high purity iron-manganese-carbon alloys. Journal Iron and Steel Institute. 200, 457-466.
[14] Subramanyam, D.K., Swansiger, A.E., Avery, H.S. (1990). Austenitic manganese steels ASM Metals Handbook 1. Properties and Selections: Irons, Steels and High - Performance Alloys. (pp. 822-840). ASM International. ISBN: 978-1-62708-161-0.
[15] Quan Shan, Ru Ge, Zulai Li, Zaifeng Zhou, Yehua Jiang, Yun-Soo Lee, & Hong Wu. (2021). Wear properties of high-manganese steel strengthened with nano-sized V2C precipitates. Wear. 482-483, 203922.
[16] Jia-li Cao, Ai-min Zhao, Ji-xiong Liu, Jian-guo He, & Ran Ding. (2014). Effect of Nb on microstructure and mechanical properties in non-magnetic high manganese steel. Journal of Iron and Steel Research International. 21(6), 600-605.
[17] Atasoy, O.A., Ozbaysal, K. & Inal, O.T. (1989). Precipitation of vanadium carbides in 0.8% C-13% Mn-1% V austenitic steel. Journal of Materials Science. 24, 1393-1398.
[18] Iglesiasa, C., Solórzanob, G. & Schulza, B. (2009). Effect of low nitrogen content on work hardening and microstructural evolution in Hadfield steel. Materials Characterization. 60(9), 971- 979.
[19] Mahlami, C.S., Pan, X. (2017). Mechanical properties and microstructure evaluation of high manganese steel alloyed with vanadium. Retrieved August 10, 2021, from https://doi.org/10.1063/1.4990236
[20] Delgado, F., Rodríguez, S.A., Coronado, J.J. (2019). Effect of chemical composition and shot peening treatment on Hadfield steel swing hammers exposed to impact wear. International Tribology Council The 10th International Conference BALTTRIB'2019, 14–16 November 2019, (pp. 87-93). Kaunas, Lithuania: Vytautas Magnus University Agriculture Academy.
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[25] Bolanowski, K. (2013). The influence of the hardness of the surface layer on the abrasion resistance of Hadfield steel. Problemy Eksploatacji. 1, 127-139.

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Authors and Affiliations

Barbara Kalandyk
ORCID: ORCID
R. Zapała
1
ORCID: ORCID
Justyna Kasińska
ORCID: ORCID
M. Madej
2

  1. AGH University of Science and Technology, Department of Cast Alloys and Composite Engineering, Faculty of Foundry Engineering, 23 Reymonta Str., 30-059 Krakow, Poland
  2. Kielce University of Technology, al. Tysiąclecia Państwa Polskiego 7, 25-314 Kielce, Poland
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Abstract

The geopolitical situation in Europe has changed dramatically due to the war waged by the Russian Federation in Ukraine. This makes it necessary to become independent from supplies of mineral resources, especially energy from Russia. According to the authors, ensuring Poland’s energy security will require a longer use of coal as the primary energy resource than initially expected. The expected increase in energy demand may cause a negative energy balance in the country. Renewable energy sources dependent on weather conditions cannot with certainty ensure energy security. On the other hand, nuclear requires large financial outlays and a longer time for reactors’ construction. In addition, it has other disadvantages (the problem of waste, environmental impact in the event of a malfunction and the need to import uranium). In these circumstances, coal may be a raw material that meets the economic needs and ensures the energy security of the country.
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Authors and Affiliations

Piotr Strzałkowski
1
ORCID: ORCID
Marek Maruszczyk
2
ORCID: ORCID

  1. Silesian University of Technology, Faculty of Mining, Safety Engineering and IndustrialAutomation, 2a Akademicka Str., 44-100 Gliwice, Poland
  2. Carbo Mar Consulting, Poland
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Abstract

The article summarizes results of the studies of the Coastal Clean Index (CCI) on selected Polish beaches. In 2022, an attempt was made to estimate the amount of litter on the beach in Ustka. Debris on the beach was collected during a peak season in July and August. An attempt was also made to estimate the daily increase in garbage on the beach. The main part of the research was based on the quality and quantity of litter in beach sediments to the east and west of Ustka. Litter was divided according to a type of material, use, size and origin. The collected material was dominated by a plastic waste. The largest amount of marine litter was collected on the beach, on the eastern side of the Słupia River.
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Authors and Affiliations

Katarzyna Bigus
1
Anna Jarosiewicz
1

  1. Pomeranian University in Słupsk, Institute of Biology and Earth Science, Arciszewskiego 22a, 76-200 Słupsk, Poland
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Abstract

The article presents results of comparative tests performed to verify the conformity of geometric deviation measurements of a crankshaft carried out at a test bed equipped with a system of elastic support with measurements adopted as reference values. A number of simulation tests were carried out with varied shaft support conditions using the proposed measuring system. The selection criteria were established for support parameters. Meeting these criteria guarantees that shaft elastic deflections and strains are eliminated. Consequently, such strains will not affect the estimation of geometrical deviations of the measured object. The comparative evaluation measurement of roundness profiles and values of roundness deviations of main crankshaft bearing journals of a marine medium speed engine was performed using a correlation calculus. The results have revealed high conformity of both determined roundness deviation values and measured profiles compared to the reference ones.

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Authors and Affiliations

Krzysztof Nozdrzykowski
Dariusz Janecki
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Abstract

The paper compares the geometrical surface structure of modelled tooth flanks of cylindrical gear obtained by a three dimensional simulation of gear generation with the geometrical surface structure of real gear obtained through chiselling by Fellows method. The paper presents the methodology of modelling tooth flanks of cylindrical gears in the CAD environment. The modelling consists in computer simulation of gear generation. The computer simulation of the gear generation was performed in the Mechanical Desktop environment. Metrological measurements of the real gear were carried out using a coordinated measuring machine and a profilometer.

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Authors and Affiliations

Leszek Skoczylas
Jacek Michalski
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Abstract

Papillophlebitis is an uncommon disease in clinical practice. We would like to present a case of a 29-year-old patient with atypical orbital pain and fl ashings, presenting relative aff erent pupillary defect and already typical of the disease entity: ophthalmoscopic picture of the fundus and big blind spot in perimetry. We present a complex and interdisciplinary diagnostic process that excludes general diseases such as hypertension, diabetes, coagulation disorders and neurological causes. We leave the only identifiable abnormality and potential source in the infl ammatory process of periodontal infl ammation and sinus jaw changes. We also describe the process of remitting the changes and fi nally a favorable end result of the primarily a very disturbing clinical picture that this disease may present.

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Authors and Affiliations

Maciej Kozak
Karolina Kapińska
Aleksandra Pawlicka
Agnieszka Wójtowicz
Ilona Pawlicka

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