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Number of results: 11
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Abstract

The paper presents a thermomechanical computational solid mechanics analysis (CSM) of a pipe "double omega", used in the steam superheaters in circulating fluidized bed (CFB) boilers. The complex cross-section shape of the "double omega" tubes requires more precise analysis in order to prevent from failure as a result of the excessive temperature and thermal stresses. The results have been obtained using the finite volume method for transient state of superheater. The calculation was carried out for the section of pipe made of low-alloy steel.
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Authors and Affiliations

Paweł Madejski
Dawid Taler
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Abstract

The conducted work shows and confirms how thermal analysis of grey and ductile iron is an important source for calculating metallurgical data to be used as input to increase the precision in simulation of cooling and solidification of cast iron. The aim with the methodology is to achieve a higher quality in the prediction of macro– and micro porosity in castings. As comparison objects standard type of sampling cups for thermal analysis (solidification module M ≈ 0.6 cm) is used. The results from thermal analysis elaborated with the ATAS MetStar system are evaluated parallel with the material quality (including tendency to external and internal defects) of the tested specimen. Significant temperatures and calculated quality parameters are evaluated in the ATAS MetStar system and used as input to calibrate the density curve as temperature function in NovaFlow&Solid simulation system. The modified data are imported to the NovaFlow&Solid simulation system and compared with real results.

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Authors and Affiliations

P-E. Persson
Z. Ignaszak
H. Fransson
V. Kropotkin
R. Andersson
A. Kump
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Abstract

Orhan Pamuk, the winner of the Nobel Prize in Literature in 2006, is one of the most interesting and versatile of contemporary writers whose prose contributes to the understanding of the cultural background of the Orient and the Occident forged out of the juxtaposition of Islam and Christianity. As a might-have-been artist, who is currently an amateur photographer, the author, in an uncommon way, visualizes the continual wonder towards colors in the surrounding reality featuring in his fictional and non-fictional texts. The most important aspects of Pamuk’s works, however, are the journeys near and far and those within oneself, as well as the wanderings through cities, especially those of his native Istanbul. Aside from the returns home and to the motherland, Pamuk contrasts the inspiring voyages out with the voyages into the collective and individual past, in all their historical and political complexity. The present paper is an overview of Orhan Pamuk’s works from the perspective of colors and the aforesaid passages, which remind his readers of travelling as a basic topos of the course of human existence.
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Authors and Affiliations

Liliana Sikorska
1

  1. Wydział Anglistyki, Uniwersytet im. AdamaMickiewicza w Poznaniu
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Abstract

Paul Valéry (1871–1945), the great French poet and essayist, did not finished his last work Mon Faust, however it was published after his death. It is poetic and philosophical drama in two parts. The story of the eponymous hero takes place in our times. Unlike in Johann Wolfgang Goethe,s Faust, the devil, not a man, is here tempted. It is obvious, because for Valéry the devil is not attractive enough to be the tempter par excellence. The unknown God is probably absent in the modern world, whereas man is lonely, tormented uncertainty. Mon Faust has not been translated into Polish, however, it is performed in theaters around the world from time to time.
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Authors and Affiliations

Jan Tomkowski
1

  1. Instytut Badań Literackich PAN, Warszawa
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Abstract

The high sensitivity of beans to herbicides is one of the limiting factors regarding the management of dicot weeds in bean crops. Protoporphyrinogen oxidase (PPO) inhibition is an important mechanism of action that has unregistered molecules with potential use in bean crops. The objectives of this study were to investigate the tolerance of Brazilian bean cultivars to distinct PPO inhibitors and to determine the existence of cross-tolerance in cultivars to the different PPO inhibitor chemical groups. In the first and second experiments, the BRSMG Talismã, Jalo Precoce, BRS Esplendor, and IPR 81 cultivars were subjected to saflufenacil doses pre- (0, 9.6, 14.1, 20.5, 30.0, and 43.8 g a.i. ‧ ha–1) and post-emergence (0, 0.7, 1.0, 1.5, 2.1, and 3.1 g a.i. ‧ ha–1). In the third experiment, the tolerance of 28 bean genotypes to saflufenacil (20.5 g a.i. ‧ ha–1) in pre-emergence was determined. In the fourth, fifth, sixth and seventh experiments, we investigated the cross-tolerance of bean to the fomesafen, flumioxazin, sulfentrazone, and saflufenacil herbicides, respectively. Even very low saflufenacil doses in post-emergence caused plants of all cultivars to die rapidly; therefore, the tolerance was much lower at this application time than in pre-emergence. There was high tolerance variability to saflufenacil among the 28 cultivars. The bean tolerance to fomesafen, flumioxazin, sulfentrazone, and saflufenacil applied pre-emergence depended on the cultivar and dose. Fomesafen was highlighted owing to its higher selectivity in relation to the different cultivars. No cross-tolerance pattern to the PPO inhibitor chemical groups applied in pre-emergence was observed among the evaluated bean cultivars. The results of this study could be of significance to farmers and technical assistance personnel, as well as for future research on cultivar breeding and the elucidation of biochemical and genetic mechanisms involved in herbicide tolerance.
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Authors and Affiliations

Antonio Pedro Brusamarello
1
Michelangelo Muzell Trezzi
1
Fortunato de Bortoli Pagnoncelli Júnior
1
Paulo Henrique de Oliveira
1
Taciane Finatto
1
Marcos Vinícius Jaeger Barancelli
1
Bruno Alcides Hammes Schmalz
1
Patrícia Bortolanza Pereira
1

  1. Department of Agronomy, Federal Technological University of Paraná (UTFPR), Brazil
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Abstract

Air entrainment defect is a common type of defect in the casting process, which will seriously affect the quality of the casting. Numerical simulation technology can predict the occurrence of casting defects according to the evolution law of liquid metal in the process of fill ing and solidification. The simulation of air entrainment process is a hot and difficult issue in the field of numerical simulation. The evolution law of air entrainment and the tracking of induced bubbles in the process of metal filling are still lacking. So is the quantitative prediction of trained gas. In this paper, based on the numerical simulation software of Inte CAST, this paper proposes an algorithm for air entrainment search and tracking, which is used to develop a quantitative prediction system for air entrainment. The feasibility of the system is verified through the simulation calculation of the typical test pieces of the air entrainment and the prediction of air entrainment defects of the casting in the process of filling is obtained through the simulation calculation of the actual casting, which can provide a certain guiding role for the optimization of the process in the production practice.
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Bibliography

[1] Hu, L., Feng, Z.P., Feng, L., Duan, S.P. & Liang, S.P. (2016). Numerical simulation of porosity defects in casting filling process. DOI:10.16410/j.issn1000-8365.2016. 02.030. (in Chinese)
[2] Bi, C. (2016). Study on numerical simulation of gas entrapment and external solidified crystals during mold filling of high pressure die casting process. Doctoral dissertation, Tsinghua University. (in Chinese).
[3] Yu, M.Q., Xia, W., Cao, W.J. & Zhou, Z.Y. (2010). Numerical simulation of filling process and air entrapment condition of Al alloy die-casting. Hot Working Technology. 01, 36-39. DOI:10.14158/j.cnki.1001-3814.2010.01.039. (in Chinese).
[4] Hernández-Ortega, Juan, J., Zamora, Rosendo, & Palacios, et al. (2007). Experimental and numerical study of air entrapment during the filling of a mould cavity in die casting. In 10th Esaform Conference on Material Forming, 18-20 April 2007 (1430-1435). Zaragoza, Spain.
[5] Guerra, F.V., Archer, L., Hardin, R.A & Beckermann C. (2019). Measurement of air entrainment during pouring of an aluminum alloy. Shape Casting. 80, 31-40. https://doi.org/10.1007/s11663-020-01998-3.
[6] Chen, Y.X., Chen, Z. & Liao, D.M. (2021). Prediction of air entrapment defect in casings based on gas phase tracking and bubble breaking criterior. Foundry. 70(07), 806-812.
[7] Caboussat, A., Picasso, M. & Rappaz, J. (2005). Numerical simulation of free surface incompressible liquid flows surrounded by compressible gas. Journal of Computational Physics. 203(2), 626-649. https://doi.org/10.1016/ j.jcp.2004.09.009.
[8] Kimatsuka, A., Ohnaka, I., Zhu, J.D., Sugiyama, A. & Kuroki, Y.(2006). Mold filling simulation for predicting gas porosity. IHI Engineering Review. 40(2), 83-88.
[9] Yang, X., Huang, X., Dai, X., Campbell, J. & Tatler, J. (2004). Numerical modelling of entrainment of oxide film defects in filling of aluminium alloy castings. International Journal of Cast Metals Research, 17(6), 321-331. https://doi.org/10.1179/136404604225022748.
[10] Dai, X., Jolly, M., Yang, X., & Campbell, J. (2012). Modelling of liquid metal flow and oxide film defects in filling of aluminium alloy castings. IOP Conference Series Materials Science and Engineering, 33(1), 2073.
[11] Reilly, C., Green, N.R., Jolly, M.R. & Gebelin, J.C. (2013). The modelling of oxide film entrainment in casting systems using computational modelling. Applied Mathematical Modelling, 37(18-19), 8451-8466. https://doi.org/10.1016/j.apm.2013.03.061.
[12] Reilly, C., Green, N.R. & Jolly, M.R. (2013). The present state of modeling entrainment defects in the shape casting process. Applied Mathematical Modelling. 37(3), 611-628. https://doi.org/10.1016/j.apm.2012.04.032.
[13] Majidi, Hojjat, S., Beckermann, & Christoph. (2017). Modelling of air entrainment during pouring of metal castings. International Journal of Cast Metals Research. 30(5), 301-315. https://doi.org/10.1080/13640461.2017. 1307624.
[14] Cao, LiuLiao, DunmingSun, FeiChen, TaoTeng, ZihaoTang, Yulong. (2018). Prediction of gas entrapment defects during zinc alloy high-pressure die casting based on gas-liquid multiphase flow model. The International Journal of Advanced Manufacturing Technology. 94, 807-815. https://doi.org/10.1007/s00170-017-0926-5.
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Authors and Affiliations

Yajun Yin
1
Yao Xie
2
Yingchen Song
1
Xu Shen
1
Xiaoyuan Ji
1
Jianxin Zhou
1

  1. Huazhong University of Science and Technology, China
  2. State Key Laboratory of Special Rare Metal Materials, China
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Abstract

The paper deals with the safety criteria of design for an infinite fatigue life of machinery parts. Uniaxial and multiaxial zero mean stress states are considered. In the latter case, constant-amplitude in-phase stress components, as well as random-amplitude synchronous stress components, are taken into account. Dimensionless and relative safety margins for these stress states are defined. The presented criteria refer to ductile materials showing true fatigue limits. Transformation rules in the plane are given for fatigue limits referenced to coordinate system different than the components of the plane stress.
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Authors and Affiliations

Janusz Kolenda
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Abstract

This article presents the assessment of the creative culture and the level of innovativeness in selected manufacture enterprises. The theoretical part of the article discusses the space for creativity in the company and the microfoundations of the pyramid of needs related to creative culture. The pyramid consists of different microfoundations, which were used to create a questionnaire to assess the level of creative culture. This study assessed creative culture according to a model of the hierarchy of needs, developed by the author of this study based on Maslow’s pyramid of needs. The assessment used an innovation questionnaire and a creative culture questionnaire. This article presents a sample analysis of the results obtained from two of the companies that participated in the study. Furthermore, the article summarizes the results obtained from all participating companies and gives recommendations related to establishing creative culture based on these results. Every company should implement appropriate standards to help it develop a creative working environment. The goal of assessing creative culture in a company is to assist managers in building a workplace that fosters creativity, since such a workplace is a significant factor affecting the emergence of innovation. The analysis of the creative culture of the companies revealed their weaknesses and strengths in this respect. The developed methodology will undoubtedly influence an increase of awareness and knowledge of enterprises in the field of creating a pro-creative company culture. Such actions will contribute to the increase of company’s innovation, thus influencing its development.
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Authors and Affiliations

Kamila Tomczak
1
ORCID: ORCID

  1. Opole University of Technology, Poland
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Abstract

The article presents results of the faunistic analysis of the Leb 1 sediment core collected from the marginal zone of the Lake Łebsko. The 5 m long core contained 10,603 specimens of freshwater and brackish-marine fauna, represented by 13 taxa of molluscs, 3 species of ostracods, 2 taxa of foraminifers and a species of the order Coleoptera, and genera Balanus and Gammarus. Lithology of the sediments and species composition of the fauna permitted distinguishing 3 development phases of the Lake Łebsko: brackish-marine phase (500–400 cm), limnic phase with varied salinity (400–100 cm) and swamp phase (100–0 cm), indicating progressive overgrowing of the marginal zone of the lake since the 13th century.
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Bibliography

Aaby, B., Berglund, B.E., 1986. Characterization of peat and lake deposits. In: Berglund, B.E. (Ed.), Handbook of Holocene Palaeoecology and Palaeohydrology. John Wiley & Sons, Chichester- New York-Brisbane-Toronto-Singapore, 231–246.

Alexandrowicz, S.W., 1998. Holocene assemblages of mollusc in the near-shore zone of Southern Baltic. Folia Malacologica 6, 15–18.

Alexandrowicz, S.W., 1999. Malacofauna and stratigraphy of Late Vistulian and Holocene deposits in the Southern Baltic Coastal Zone. Quaternary Studies in Poland spec. issue, 37–50.

Alexandrowicz, S.W., Alexandrowicz, W.P., 2011. Malacological analysis. Methods of research and interpretations (Analiza malakologiczna. Metody badań i interpretacji). Polska Akademia Umiejętności, Rozprawy Wydziału Przyrodniczego 3, 1–300 (in Polish).

Brodniewicz, I., 1965. Recent and some Holocene Foraminifera of the Southern Baltic Sea. Acta Palaeontologica Polonica 10 (2), 131–235.

Brodniewicz, I., 1972. Brenkowo. Faunal analysis. Guide-book of the excursion. International Conference in Poland, Sopot, September, 22–26, 1972.

INQUA, Subcomission on Shorelines of Nortwestern Europe, 29–32. Brodniewicz, I., Rosa, B., 1967. The boring hole and the fauna at Czołpino, Poland. Baltica 3, 61–86.

Bronk Ramsey, C., 2009. Bayesian analysis of radiocarbon dates. Radiocarbon 51 (1), 337–360.

Falniowski, A., 1987. Hydrobioidea of Poland. Folia Malacologica 1, 1–122.

Falniowski, A., 1989. Przodoskrzelne (Prosobranchia, Gastropoda, Mollusca) Polski. 1. Neritidae, Viviparidae, Valvatidae, Bithyniidae, Rissoidae, Aciculidae. Zeszyty Naukowe Uniwersytetu Jagiellońskiego, CMX, Prace Zoologiczne 35, 1–148 (in Polish with English summary).

Grimm, E.C., 1990. TILIA and TILIA.GRAPH. PC spreadsheet and graphics software for pollen data. INQUA Working Group on Data-Handling Methods Newsletter 4, 5–7.

Jagnow, B., Gosselck, F., 1987. Bestimmungsschlüssel für die Gehäuseschnecken und Muscheln der Ostsee. Mitteilungen aus dem Museum für Naturkunde in Berlin. Zoologisches Museum und Institut für Spezielle Zoologie (Berlin) 63 (2), 191–268.

Keyser, D., Aladin, N., 2004. Noding in Cyprideis torosa and its causes. Studia Quaternaria 21, 19–24. Piechocki, A., 1979. Mięczaki (Mollusca), Ślimaki (Gastropoda). Fauna słodkowodna Polski 7, Państwowe Wydawnictwo Naukowe, Warszawa-Poznań, 6–174 (in Polish).

Piechocki, A., Dyduch-Falniowska, A., 1993. Miȩczaki (Mollusca), Małże (Bivalvia), Fauna słodkowodna Polski 7A, Wydawnictwo Naukowe PWN, pp. 200 (in Polish).

Rotnicki, K., 2001. Stratigraphy and palaeogeography of Vistulian of the Gardno-Łeba Lowland (Stratygrafia i paleogeografia vistulianu Niziny Gardnieńsko-Łebskiej). In: Rotnicki, K. (Ed.), Przemiany środowiska geograficznego nizin nadmorskich południowego Bałtyku w vistulianie i holocenie. Bogucki Wydawnictwo Naukowe, Poznań, 19–29 (in Polish).

Rotnicki, K., Alexandrowicz, S.W., Pazdur, A., Goslar, T., Borówka, R.K., 2009. Stages of the formation of the Łeba Barrier – lagoon system on the basis of the geological cross-section near Rąbka (southern Baltic coast, Poland). Studia Quaternaria 26, 3–24.

Sywula, T., 1974. Małżoraczki (Ostracoda). Fauna słodkowodna Polski. Z. 24, Polska Akademia Nauk, Instytut Zoologii, Oddział w Poznaniu, Państwowe Wydawnictwo Naukowe, Warszawa-Poznań, 279 (in Polish).

Tobolski, K., 1972. Age and genesis of dunes at the south-eastern shore of Lake Łebsko. Badania Fizjograficzne nad Polską Zachodnią 25B, 135–146 (in Polish with English summary).

Troels-Smith, J., 1955. Characterisation of unconsolidated sediments. Danmarks Geologiske Undersøgelse Ser. IV, 3 (10), 1–73.

van Harten, D., 2000. Variable noding in Cyprideis torosa (Ostracoda, Crustacea): an overview, experimental results and a model from Catastrophe Theory. Hydrobiologia 419, 131–139.

Wojciechowski, A., 1994. Deposits, brackish-water and marine malacofauna of the Holocene age in Lake Łebsko, Gardno-Łeba Coastal Coastal Plain. In: Rotnicki, K. (Ed.), Polish Coast – Past, Present and Future. Quaternary Research Institute, Adam Mickiewicz University, Poznań, 96–100.

Wojciechowski, A., 1995. Holocene deposits and molluscan assemblages in Lake Łebsko, Gardno-Łeba Coastal Plain. Journal of Coastal Research SI 22, 237–243.

Wojciechowski, A., 1996. Principles of malacostratigraphy of the South Baltic lakes (Podstawy malakostratygrafii jezior południowobałtyckich). XII Krajowe Seminarium Malakologiczne, Łódź, 25–27 kwietnia 1996, 40–41 (in Polish).

Wojciechowski, A., 1999. Holocene mollusc assemblages in the Kluki- 115a profile, Gardno-Łeba Coastal Plain. In: Borówka, R.K., Młynarczyk, Z., Wojciechowski, A. (Eds), Ewolucja geosystemów nadmorskich południowego Bałtyku. Bogucki Wydawnictwo Naukowe, Poznań-Szczecin, 175–185 (in Polish with English summary).

Wojciechowski, A., 2007. New malacological profiles from Lake Łebsko and their stratigraphical significance. In: Florek, W. (Ed.), Geologia i geomorfologia pobrzeża i południowego Bałtyku 7, 101–127 (in Polish with English summary).

Wojciechowski, A., 2008. Evolution of coastal lakes of the Gardno-Łeba Lowland in the light of malacological research. Landform Analysis 7, 154–171 (in Polish with English summary).

Wojciechowski, A., 2011. Stages of the evolution of the South Baltic coast as recorded in the molluscan fauna. Journal of Coastal Research SI 64, 711–715.
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Authors and Affiliations

Paulina Wojciechowska
1
Adam Wojciechowski
1

  1. Pomeranian University in Słupsk, Institute of Biology and Earth Sciences, ul. Partyzantów 27, 76-200 Słupsk, Poland
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Abstract

Throughout 1978 regular counts of pinniped mammals were conducted along as 12-kilometre-long stretch of the Admiralty Bay coasts. The occurrence of all the six species of antarctic seals was noted, among them the most numerous were Mirounga leonina, Arctocephalus tropicalis and Lobodon carcinophagus. The number of these animals varied within a year-cycle. M. leonina and Leptonychotes weddelli breed at Admiralty Bay.

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Authors and Affiliations

Andrzej Myrcha
Karol Teliga

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