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Number of results: 9
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Abstract

The present study aimed at a determination of the formula allowing water content to be calculated for model degraded soil enriched with Biona-312 ion exchange substrate. To this end a mixture of sand and Biona- 312 was prepared which was monitored for water content changes. Moisture was determined both gravimetrically and reflectometrically (TOR method). To improve the reliability of the TOR method individual calibration was made. The specific calibration formula as polynomial of the third degree was found for water content determination in sand supplemented with Biona-312. The results confirmed the high potential of the TOR method in moisture monitoring, especially when individual calibration is done.
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Authors and Affiliations

Mariola Chomczyńska
Zbigniew Suchorab
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Abstract

Nifedipine, a pyridine derivative was investigated as corrosion inhibitor for API 5L X-52 steel in 2 M HCl solution by potentiodynamic polarization, electrochemical impedance spectroscopy and quantum chemical calculations. Statistical tools were used to compare results of the experimental methods. The results showed that nifedipine is capable of inhibiting the corrosion of API 5L X-52 steel in 2 M HCl solution. Potentiodynamic polarization results reveal that nifedipine functions as a mixed-type inhibitor and presents an inhibition efficiency of about 78% at 500 ppm. Impedance data reveal an increasing charge transfer resistance with increasing inhibitor concentration and also shows comparable inhibition efficiency of about 89-94% at 500 ppm. Thermodynamic parameters imply that nifedipine is adsorbed on the steel surface by a physiochemical process and obeys Langmuir adsorption isotherm. The calculated molecular properties namely the highest occupied molecular orbital energy, lowest unoccupied molecular orbital energy, chemical hardness, energy gap, dipole moment, electronegativity and global nucleophilicity index all show a positive relationship to the observed corrosion inhibition efficiency.

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Authors and Affiliations

Magdalene Edet Ikpi
Fidelis Ebunta Abeng
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Abstract

The article describes the design of a proven technology for the production of metal foam and porous metal by the foundry. Porous metal formed by infiltrating liquid metal into a mould cavity appears to be the fastest and most economical method. However, even here we cannot do without the right production parameters. Based on the research, the production process was optimised and subsequently a functional sample of metal foam with an irregular internal structure - a filter - was produced. The copper alloy filter was cast into a gypsum mould using an evaporable model.
Furthermore, a functional sample of porous metal with a regular internal structure was produced - a heat exchanger. The aluminium alloy heat exchanger was cast into a green sand mould using preforms. Also, a porous metal casting with a regular internal structure was formed for use as an element in deformation zones. This aluminium alloy casting was made by the Lost Foam method. The aim is therefore to ensure the production of healthy castings, which would find use in the field of filtration of liquid metal or flue gases, in vehicles in the field of shock energy absorption and also in energy as a heat exchanger.
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Bibliography

[1] Lefebvre, L.P., Banhart, J. & Dunand, D. (2008). Porous metals and metallic foams: current status and recent developments. Advanced Engineering Materials. 10(9), 775-787.
[2] Banhart, J. (2001). Manufacture, characterisation and application of cellular metals and metal foams. Progress in Materials Science. 46(6), 559-632.
[3] Banhart, J. (2007). Metal Foams - from Fundamental Research to Applications [online], URL: < https://www.helmholtz-berlin.de/media/media/spezial/people/banhart/html/B-Conferences/b097_banhart2007.pdf>.
[4] Gaillard, Y., Dairon, J., & Fleuriot, M. (2011). Porous materials: innovations with many uses. Slévárenství. 11-12, roč. LIX, 374-378. (in Czech).
[5] Banhart, J. (2005). Aluminium foams for lighter vehicles. International Journal of Vehicle Design. 37, Nos. 2/3, 114-125. [online]. URL: < http://www.helmholtz-berlin.de/media/media/spezial/people/banhart/html/A-Journals/open/article/a082_banhart2005.pdf>.
[6] García-Moreno, F. Commercial Applications of Metal Foams: Their Properties and Production. [online]. URL: < http://www.mdpi.com/1996-1944/9/2/85/html>.
[7] Banhart, J. Metallic Foams II: properties and application [online]. URL: < http://materialsknowledge.org/docs/ Banhart-talk2.pdf>.
[8] Landolsi, M.W. (2016). Metal foam - an innovative material. [online]. URL: < https://conceptec.net/actualites/innovations/ 111-mousse-metallique-un-materiau-innovant>. (in Czech).
[9] Lulusoso. Composite cladding panel manufacturers [online]. URL: < http://www.lulusoso.com/products/ Composite-Cladding-Panel-Manufacturers.html>.
[10] Erg Materials and Aerospace; Duocel® Foam Cells. [online]. URL: < http://www.ergaerospace.com/products/ fuel-cells.html>.
[11] Kroupová, I., Lichý, P., Ličev, L., Hendrych, J. & Souček, K. (2018). Evaluation of properties of cast metal foams with irregular inner structure. Archives of Metallurgy and Materials. 63(4), 1845-1849. ISSN 1733-3490.
[12] Kroupova, I., Bednarova, V., Elbel, T. & Radkovsky, F. (2014). Proposal of method of removal of mould material from the fine structure of metallic foams used as filters. Archives of Metallurgy and Materials. 59(2), 727-730. ISSN 1733-3490.
[13] Yamada. Y., Shimojima, K., Sakaguchi, Y., Mabuchi, M., Nakamura, M., Asahina, T., Mukai, T., Kanahashi, H. & Higashi, K. (2000). Effects of heat treatment on compressive properties of AZ91 Mg and SG91A Al foams with open-cell structure. Materials Science and Engineering: A. 280(1), 225-228. DOI: https://doi.org/ 10.1016/S0921-5093(99)00671-1.
[14] Gawdzinska, K., Chybowski, L. & Przetakiewicz, W. (2017). Study of thermal properties of cast metal-ceramic composite foams. Archives of Metallurgy and Materials. 17(4), 47-50. ISSN 1897-3310.
[15] Haack, P.D., Butcher, R.P., Kim, T. & Lu, J.T. (2001). Novel lightweight metal foam heat exchangers. porvair fuel cell technology, Inc., Department of Engineering, University of Cambridge. January, [online]. URL: < https://www.researchgate.net/publication/267721239_Novel_Lightweight_Metal_Foam_Heat_Exchangers>.
[16] Radkovský, F., Merta, V. (2020). Use of numerical simulation in production of porous metal casting. Archives of Metallurgy and Materials. 54(2), 259-261. ISSN 1580-2949. DOI: 10.17222/mit.2019.145.
[17] Radkovský, F., Gebauer, M., Kroupová, I., Lichý, P. (2017). Metal foam as a heat exchanger. In METAL 2017, Conference proceedings, 26th Anniversary International Conference on Metallurgy and Materials, Tanger Ltd., Ostrava, 24. - 26. 5. 2017, Hotel Voroněž I, Brno.
[18] Lu, T.J., Stone, H.A. & Ashby, M.F. (1998). Heat transfer in open-cell metal foams. Acta Materialia. 46(10, 12) June, 3619-3635. DOI: https://doi.org/10.1016/S1359-6454(98) 00031-7
[19] Boomsma, K., Poulikakos, D. & Zwick, F. (2003). Metal foams as compact high performance heat exchangers. Mechanics of Materials, 35(12), 1161-1176. DOI: https://doi.org/10.1016/j.mechmat.2003.02.001.
[20] Hutter, C., Büchi, D., Zuber, V. & Rohr, R. (2011). Heat transfer in metal foams and designed porous media. Chemical Engineering Science. 66(17), 1 September 2011, 3806-3814. DOI: https://doi.org/10.1016/j.ces.2011.05.005
[21] Lichý, P., Elbel, T., Kroupová, I. & Radkovský, F. (2017). Preparation and evaluation of properties of cast metallic foams with regular inner structure. Archives of Metallurgy and Materials. 62(3), 1643-1646. ISSN 1733-3490. DOI: 10.1515/amm-2017-0251.
[22] Romanek, T. (2017). Manufacturing and Properties of Cast Metallic Foams with Regular Structure, Ostrava, Diploma thesis, VSB - Technical University of Ostrava, [online]. URL: http://www.ergaerospace.com/products/fuel-cells.htm>.
[23] Radkovský, F., Gebauer, M. & Merta, V. (2018). Optimizing of metal foam design for the use as a heat exchanger. Archives of Metallurgy and Materials. 63(4), 1875-1881. ISSN 1733-3490.

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Authors and Affiliations

F. Radkovský
1
ORCID: ORCID
V. Merta
1
ORCID: ORCID
T. Obzina
1

  1. VSB - Technical University of Ostrava, Czech Republic
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Abstract

Localization systems are an important component of Active and Assisted Living (AAL) platforms supporting persons with cognitive impairments. The paper presents a positioning system being a part of the platform developed within the IONIS European project. The system’s main function is providing the platform with data on user mobility and localization, which would be used to analyze his/her behavior and detect dementia wandering symptoms. An additional function of the system is localization of items, which are frequently misplaced by dementia sufferers.

The paper includes a brief description of system’s architecture, design of anchor nodes and tags and exchange of data between devices. both localization algorithms for user and item positioning are also presented. Exemplary results illustrating the system’s capabilities are also included.

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Authors and Affiliations

Jerzy Kolakowski
Vitomir Djaja-Josko
Marcin Kolakowski
Jacek Cichocki
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Abstract

Craniopharyngiomas are rare tumors with peak incidence between 5–14 and between 65–74 years of age. Treatment of choice is surgical resection, sometimes associated with radiation therapy. Complete tumor resection may be challenging. Radical surgery is particularly risky in older patients. Authors evaluate three cases of large cystic craniopharyngioma in patients in their 7th and 8th decade of life operated with the use of endoscopic technique. The postoperative follow-up period in which out-patient controls with imaging examinations were performed was up to 6 years. Symptoms of intracranial hypertension resolved in all patients in the immediate postoperative period. Visual acuity improved in two patients. No cases of aseptic meningitis have been reported. One patient underwent subsequent radio-therapy. The well-being of the operated patients continued.
Endoscopic transventricular approach to cystic craniopharyngiomas may be a safe and effective approach in older patients, being an alternative to microsurgical procedures.
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Authors and Affiliations

Krzysztof Stachura
1
Ewelina Grzywna
1
Maciej J. Frączek
1

  1. Department of Neurosurgery and Neurotraumatology, Faculty of Medicine, Jagiellonian University Medical College, Kraków, Poland
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Abstract

Experiments have been carried out on the influence exerted by Aroclor 1254 upon the photosynthetic production of organic 14C by an assemblage of marine Antarctic diatoms (Thalassiosira sp. 48%, Nitzschia sp. 21%, Chaetoceros sp. 15% and Corethron iriophilum 10%). Samples of various numbers of cells per cm3 of water have been used. Incorporation of 14C02 by the diatoms proved to be proportional to the increased number of cells in the sample only at the lowest levels of concentration in per cm3. Further increase of the level of 14C in diatoms has not been found as number of cells in the sample kept growing. Calculation of brutto photosynthesis has indicated that low concentration of Aroclor 1254 (0,01 to 1 ppm) may stimulate the photosynthetic incorporation of carbon, yet the photosynthetic release of carbon from cells within the photorespiratory process is stimulated to a higher degree. High concentration of Aroclor (1 to 50 ppm) inhibit the brutto assimilation, yet the release of carbon during the photorespiratory process is inhibited to a higher degree. A hypothesis is being considered implying that the relation between the intensity of photosynthesis and intensity of photorespiration may vary according to the rate of concentration of Aroclor.

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Authors and Affiliations

Grażyna Bystrzejewska
Aleksy Łukowski
Ryszard Ligowski
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Abstract

This paper describes a “distributed method” of introducing the humanitarian engineering principles and concepts to the curriculum of telecommunications at a maritime university. That is by modifying appropriately the syllabi of the telecommunications subjects taught. The propositions made in this area are illustrated by the concrete examples taken from the current Polish Qualifications Framework for the higher education system in Poland. And, for clarity and consistency of presentation, fundamentals and principles as well as a basic terminology and features of this Framework are also highlighted here shortly. Moreover, it has been shown that the approach presented in this paper is more useful compared to a method based on organization of some special courses for students on the humanitarian engineering, in particular when this regards a maritime university.

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Authors and Affiliations

Andrzej Borys
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Abstract

In recent years, two developments revolutionized the molecular genetics. The first one is an enormously improved technique of the DNA sequencing. It is now possible to obtain in couple of hours and on the low cost, the full sequence of the human genome. The second one is the invention of the CRISPR-Cas technique, which allows the precise manipulations of genomes of living organisms. This technique was already successfully applied to “repair” human genes responsible for hereditary diseases. To some astonishment, applications of genetic engineering to humans does not bring protests of general public, while similar manipulations pf plants genomes are considered an dangerous. In Poland and in some other countries, parliaments introduced an extremely restrictive laws, which in practice makes cultivation of GM plants outside laboratories impossible. This is caused by the ignorance of the general public and by opposition of catholic church which considers genetic modifications of all organisms as contradictory with Gods will. The most common modification of plants is an introduction into their genomes of the single gene from the bacterium Bacillus thuringensis, what make the plant resistant to harmful insects. According to WHO, neither the manipulation mentioned above, nor manipulations of the other kind, do not pose any danger to humans.

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Authors and Affiliations

Piotr Węgleński

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