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Effect of harvest date on structural carbohydrates and lignin content in meadow sward in different pluvio-thermal conditions

Barbara Wróbel Waldemar Zielewicz Anna Paszkiewicz-Jasińska Bartosz Spychalski Zuzanna Jakubowska
Journal of Water and Land Development | 2022 | No 55 | 60-66 | DOI: 10.24425/jwld.2022.142305
Keywords air temperature cellulose digestibility of feed hemicelluloses lignin nutritional value sum of precipitation
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Abstract

The content of structural carbohydrates and lignin are important assessment criteria of the feed value of meadow plants. It is affected by many independent factors, including among others its development stage during the harvest as well as climatic conditions, especially the amount of rainfall. During the years 2014–2016, plant samples were harvested at weekly intervals, respectively five times from late April to late May. The effect of harvest date on cellulose, hemicelluloses and lignin contents was evaluated. The chemical composition of plants was varied, depending not only on harvest date but also on the year of study. Regardless of the course of meteorological conditions in subsequent growing seasons, the increase of cellulose (from 236.5 to 297.9 g∙kg–1 DM), hemicelluloses (from 159.3 to 210.8 g∙kg–1 DM), and lignin (from 31.5 to 43.1 g∙kg–1 DM) in the following dates of harvest were observed. These parameters were also positively correlated with the total rainfall from the begging of vegetation season to the date of plants sampling (R2 = 0.65, 0.12 and 0.44 for cellulose, hemicelluloses and lignin, respectively), and with the average daily air temperature in the moment of harvest (R2 = 0.66, 0.32 and 0.52 for cellulose, hemicelluloses and lignin, respectively). The cellulose and lignin content, regardless of the harvest date, were significantly higher in the first year of the study (2014), when moisture conditions for plant development were optimal.
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Authors and Affiliations

Barbara Wróbel
1
ORCID: ORCID
Waldemar Zielewicz
2
ORCID: ORCID
Anna Paszkiewicz-Jasińska
1
ORCID: ORCID
Bartosz Spychalski
1
Zuzanna Jakubowska
1
  1. Institute of Technology and Life Sciences – National Research Institute, Falenty, al. Hrabska 3, 05-090 Raszyn, Poland
  2. Poznań University of Life Sciences, Department of Grassland and Natural Landscape Sciences, Poznań, Poland

The Influence of Optimization Parameters on the Efficiency of Aluminium Melt Refining by using Physical Modelling

J. Walek K. Michalek M. Tkadlečková
Archives of Foundry Engineering | 2022 | vol. 22 | No 3 | 60-66 | DOI: 10.24425/afe.2022.140237
Keywords physical modelling Refining ladle Blowing of inert gas Degassing of the melt Impeller
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Abstract

The article describes the influence of optimization parameters on the efficiency of aluminium melt refining by using physical modelling. The blowing of refining gas, through a rotating impeller into the ladle is a widely used operating technology to reduce the content of impurities in molten aluminium, e.g. hydrogen. The efficiency of this refining process depends on the creation of fine bubbles with a high interphase surface, wide-spread distribution, the residence time of its effect in the melt, and mostly on the wide-spread dispersion of bubbles in the whole volume of the refining ladle and with the long period of their effect in the melt. For physical modelling, a plexiglass model on a scale of 1:1 is used for the operating ladle. Part of the physical model is a hollow shaft used for gas supply equipped with an impeller and also two baffles. The basis of physical modelling consists in the targeted utilization of the similarities of the processes that take place within the actual device and its model. The degassing process of aluminium melt by blowing inert gas is simulated in physical modelling by a decrease of dissolved oxygen in the model liquid (water).
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Bibliography

[1] Michalek, K., Tkadlečková, M., Socha, L., Gryc, K., Saternus, M., Pieprzyca, J. & Merder, T. (2018). Physical modelling of degassing process by blowing of inert gas. Archives of Metallurgy and Materials. 63(2), 987-992. DOI: 10.24425/122432.
[2] Hernández-Hernández, M., Camacho-Martínez, J., González-Rivera, C. & Ramírez-Argáez, M.A. (2016). Impeller design assisted by physical modelling and pilot plant trials. Journal of Materials Processing Technology. 236, 1-8. DOI: 10.1016/j.jmatprotec.2016.04.031.
[3] Mostafei, M., Ghodabi, M., Eisaabadi, G.B., Uludag, M. & Tiryakioglu, M. (2016). Evaluation of the effects rotary degassing process variables on the quality of A357 aluminium alloy castings. Metallurgical and Materials Transactions B. 47(6), 3469-3475. DOI: 10.1017/s11663-016-0786-7.
[4] Merder, T., Saternus, M. & Warzecha, P. (2014). Possibilities of 3D Model application in the process of aluminium refining in the unit with rotary impeller. Archives of Metallurgy and Materials. 59(2), 789-794. DOI: 10.2478/amm-2014-0134.
[5] Saternus, M., Merder, T. & Pieprzyca, J. (2015). The influence of impeller geometry on the gas bubbles dispersion in URO-200 reactor – RTD curves. Archives of Metallurgy and Materials. 60(4), 2887-2893. DOI: 10.1515/amm-2015-0461.
[6] Yamamoto, T., Suzuki, A., Komarov, S.V. & Ishiwata, Y. (2018). Investigation of impeller design and flow structures in mechanical stirring of molten aluminium. Journal of Materials Processing Technology. 261, 164-172. DOI: 10.1016/j.jmatprotec.2018.06.012.
[7] Gao, G., Wang, M., Shi, D. & Kang, Y. (2019). Simulation of bubble behavior in a water physical model of an aluminium degassing ladle unit employing compound technique of rotary blowing and ultrasonic. Metallurgical and Materials Transactions B. 50(4), 1997-2005. DOI: 10.1017/j.s11663-019-01607-y. [8] Yu, S., Zou, Z.-S., Shao, L. & Louhenkilpi, S. (2017). A theoretical scaling equation for designing physical modelling of gas-liquid flow in metallurgical ladles. Steel Research International. 88(1), 1600156. DOI: 10.1002/srin.201600156.
[9] Abreu-López, D., Dutta, A., Camacho-Martínez, J.L., Trápaga-Martínez, G. & Ramírez-Argáez, M. A. (2018). Mass transfer study of a batch aluminium degassing ladle with multiple designs of rotating impellers. JOM. 70, 2958-2967. DOI: 10.1007/s11837-018-3147-y.
[10] Walek, J., Michalek, K., Tkadlečková, M. & Saternus, M. (2021). Modelling of technological parameters of aluminium melt refining in the ladle by blowing of inert gas through the rotating impeller. Metals. 11(2), 284. DOI: 10.3390/met11020284.
[11] Saternus, M. & Merder, T. (2018). Physical modelling of aluminium refining process conducted in batch reactor with rotary impeller. Metals. 8(9), 726. DOI: 10.3390/met8090726.
[12] Lichý, P., Bajerová, M., Kroupová, I. & Obzina, T. (2020). Refining aluminium-alloy melts with graphite rotors. Materiali in Technologije. 54(2), 263-265. DOI: 10.17222/mit.2019.147.
[13] Lichý, P., Kroupová, I., Radkovský, F. & Nguyenová, I. (2016). Possibilities of the controlled gasification of aluminium alloys for eliminating the casting defects. 25th Anniversary International Conference on Metallurgy and Materials, May 25th - 27th 2016 (1474-1479). Hotel Voroněž I, Brno, Czech Republic, EU: Lichý, P.

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Authors and Affiliations

J. Walek
1
ORCID: ORCID
K. Michalek
1
ORCID: ORCID
M. Tkadlečková
1
ORCID: ORCID
  1. VŠB - Technical University of Ostrava, Faculty of Materials Science and Technology, Department of Metallurgical Technologies

Application of Natural and Artificial Ageing on Multiply Remelted AlSi9Cu3 Alloy

M. Matejka D. Bolibruchová
Archives of Foundry Engineering | 2019 | vol. 19 | No 2 | 60-66 | DOI: 10.24425/afe.2019.127117
Keywords Remelting Fe phases Artificial ageing Natural Ageing Eutectic silicon
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Abstract

This article focuses on the study of the influence of remelting and subsequent natural and artificial ageing on the structure of recycled AlSi9Cu3 alloy with increased iron content. The assessed changes in eutectic silicon and iron-based intermetallic phases were carried out using optical and scanning electron microscopy. The degradation of the eutectic silicon morphology due to remelting occurred only at the highest numbers of remelting. The effect of remelting the investigated alloy, which is accompanied by a gradual increase in wt. % Fe, began to manifest significantly through a change in the length of the ferric phases after the fourth remelting. As expected, the artificial ageing process has proven to be more effective than natural ageing. It has led to a change in the eutectic silicon morphology and has been beneficial in reducing the lengths of adverse ferric phases. The use of alloys with higher numbers of remelting, or with greater “contamination”, for the manufacture of shape-challenging castings is possible when using a suitable method of eliminating the negative factors of the remelting process. The results of our investigation show a suitable method of the above elimination the application of heat treatment T5 – via artificial ageing.

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Authors and Affiliations

M. Matejka
D. Bolibruchová

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