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Abstract

Fabrication and microstructure of the AlSi11 matrix composite containing 10 % volume fraction of CrFe30C8 particles were presented in this paper. Composite suspension was manufactured by using mechanical stirring. During stirring process the temperature of liquid metal, time of mixing and rotational speed of mixer were fixed. After stirring process composite suspension was gravity cast into shell mould. The composites were cast, applying simultaneously an electromagnetic field. The aim of the present study was to determine the effect of changes in the frequency of the current power inductor on the morphology of the reinforcing phase in the aluminum matrix. The concept is based on the assumption that a chromium-iron matrix of CrFe30C8 particles dissolves and residual carbide phases will substantially strengthen the composite. The microstructure and interface structure of the AlSi11/CrFe30C8 composite has been studied by optical microscopy, scanning microscopy and X-ray diffraction.

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Authors and Affiliations

A. Dulęba
M. Cholewa
D. Scelina
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Abstract

This work deals with the problem of intermetallic phases in cast standard duplex steel ASTM A890 Gr 4A (generally known as 2205). The investigated steel was subjected to isothermal heat treatment in the range from 595 °C to 900 °C and in the duration from 15 minutes to 245 hours, and was also investigated in terms of anisothermal (natural) cooling after casting into the mould. The precipitation starts at grain boundaries with a consistent ferrite transformation. The work is focused on the precipitation of the sigma phase (σ) and the chi phase (χ). Examination of the microstructure was conducted using light and scanning electron microscopy. Their statistical analysis was carried out using the results of the investigations of precipitation processes in the microstructure, both within the grains and at the grain boundaries. To illustrate this impact, the surface area of precipitates was evaluated. The percentage of these intermetallic phases was calculated by measuring their area using a computer image analysis system. Based on their observations, a combined time-temperature transformation (TTT) diagram with continuous cooling transformation (CCT) curves was created.
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Authors and Affiliations

M. Myška
1
ORCID: ORCID
P. Bořil
1
ORCID: ORCID
V. Krutiš
1
ORCID: ORCID
V. Kaňa
1
ORCID: ORCID
A. Zádĕra
1
ORCID: ORCID

  1. Brno University of Technology, Czech Republic
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Abstract

Geopolymer is widely studied nowadays in various scope of studies. Some of the ongoing studies are the study of the various materials towards the geopolymer strength produced. Meanwhile, some of the studies focus on the mixing of the geopolymer itself. This paper discussed the phase analysis of metakaolin/dolomite geopolymer for different solid to the liquid ratio which was, 0.4, 0.6, 0.8, and 1.0, and the properties that affected the geopolymer based on the phases. The constant parameters in this study were the percentage of metakaolin and dolomite used. The metakaolin used was 80% meanwhile dolomite usage was 20%. Besides that, the molarity of NaOH used is 10M and the alkaline activator ratio used is 2.0. All the samples were tested at 28 days of curing. The results show that the 0.8 solid to the liquid ratio used gave better properties compare to other solid to liquid ratio. The phases analyzed were quartz, sillimanite, mullite, and faujasite. The 0.8 S/L ratio shows the better properties compared to others by the test of phase analysis, compressive strength morphology analysis, and functional group analysis.
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Authors and Affiliations

Ahmad Syauqi Sauffi
1
ORCID: ORCID
Wan Mastura Wan Ibrahim
1
ORCID: ORCID
Mohd Mustafa Al Bakri Abdullah
2
ORCID: ORCID
Masdiyana Ibrahim
1
ORCID: ORCID
Romisuhani Ahmad
1
ORCID: ORCID
Fakhryna Ahmad Zaidi
1
ORCID: ORCID

  1. Universiti Malaysia Perlis (UniMAP), Faculty of Engineering Technology, P. O. Box 77, d/a Pejabat, Pos Besar, 01007 Kangar, Perlis, Malaysia
  2. Universiti Malaysia Perlis (UniMAP), Centre of Excellence Geopolymer and Green Technology, School of Material Engineering, P. O. Box 77, d/a Pejabat, Pos Besar, 01007 Kangar, Perlis, Malaysia
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Abstract

The presented climatostratigraphy of the Holocene on the territory of Poland is based on a range of biotic, sedimentological, geomorphological and isotopic records, but also takes into account fluctuations of temperature and hydrologi- cal regime. The author upholds the traditional division of the Holocene into three thermic phases and discusses in detail distinct fluctuations in the hydrological regime reflected in the alteration of wetter and drier phases. Although their profiles tend to be blurred, the lower boundaries of the wetter phases, which set off the transformation of geoeco- systems (a process reflected in the first clusters of extreme events), may be used to identify regional stratigraphic subdivisions. The superimposed phases of human activity have much smaller spatial extent.
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Authors and Affiliations

Leszek Starkel
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Abstract

Horizontal centrifugal casting is an effective method for the production of hollow metal with good mechanical properties, low defect, cast

to size and relatively cheap. The ability of a metal to satisfy the above requirements highly depends on its microstructure. In this study, the

relationship between microstructural parameters such as grain size and the amount of phases with bulk hardness of SnCu4Pb3 is concerned

in three areas of the product. Consequently, to achieve the desired hardness of the product in a particular area, the interaction of two

factors of the microstructure including, grain size and particles amount of the hard intermetallic compositions (Cu6Sn5) should be noted.

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Authors and Affiliations

S.E. Vahdat
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Abstract

Effects of confinement on mechanical, structural and thermodynamic properties of uniform fluids are very well understood. In contrast, a general theory based on statistical thermodynamics for confined nonuniform and non-isotropic phases, such as the lamellar phase, is in its infancy. In this review we focus on the lamellar phase confined in a slit or in a pipe in order to illustrate various effects of confinement. We limit ourselves to the results obtained by M. Tasinkevych, V. Babin and the author for lamellar phases in oil-water-surfactant mixtures within a generic semi-microscopic model, using a mean-field approximation. We show that compared to isotropic fluids the excess grand potential contains additional terms associated with structural deformations. These terms depend on the type of the confining walls, the shape of the container and on the thickness of the lamella. As a result of the dependence of the structure of the confined lamellar phase on the shape of the container, capillary lamellarization and capillary delamellarization is found in slits and in pipes respectively.

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Authors and Affiliations

A. Ciach
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Abstract

In the present paper it is proposed to consider the computer cooling capacity using the thermosyphon loop. A closed thermosyphon loop consists of combined two heaters and a cooler connected to each other by tubes. The first heater may be a CPU processor located on the motherboard of the personal computer. The second heater may be a chip of a graphic card placed perpendicular to the motherboard of personal computer. The cooler can be placed above the heaters on the computer chassis. The thermosyphon cooling system on the use of computer can be modeled using the rectangular thermosyphon loop with minichannels heated at the bottom horizontal side and the bottom vertical side and cooled at the upper vertical side. The riser and a downcomer connect these parts. A one-dimensional model of two-phase flow and heat transfer in a closed thermosyphon loop is based on mass, momentum, and energy balances in the evaporators, rising tube, condenser and the falling tube. The separate two-phase flow model is used in calculations. A numerical investigation for the analysis of the mass flux rate and heat transfer coefficient in the steady state has been accomplished.

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Authors and Affiliations

Jarosław Mikielewicz
Henryk Bieliński
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Abstract

Structures and characteristics ofwideband small-size phase shiftersmade with the use of single parallel stubs are presented in this paper. The stubs can be short-circuited or open-circuited on termination. Such devices arewell known, but are primarily used as components of filters ormatching circuits. The novelty, then, comes from the establishment of simple, but helpful formulae, which enable to describe the insertion phase shift and differential phase shift of a line with short and open stubs connected in parallel. These equations can be very useful for designing complex microwave multi-ports. The results of simulations and measurements of the devices, which were designed and made, are shown herein. It was also proved that the presented devices have several usable operating frequency sub-bands, and that the differential phase shift values in the higher sub-bands are greater than those in the lower operating frequency ranges. Thanks to this, the described phase shifters can be used in more than one frequency sub-band. It was stated that in the conditions under analysis, larger phase shifts can be achieved using open-circuited stubs rather than short-circuited stubs. However, the phase shifters with shorted parallel stubs can operate in a wider frequency band.

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Authors and Affiliations

Adam Rutkowski
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Abstract

This article presents the results of studies into the phase and chemical composition of blast furnace slag in the context of its reuse. In practice, blast furnace slags are widely used in the construction industry and road building as a basis for the production of, for example, cements, road binders and slag bricks. T hey are also used in the production of concrete floors, mortars, and plasters. Blast furnace slag is mainly used as a valuable material in the production of hydraulic binders, especially cement that improves the mechanical properties of concretes.
The favorable physical and mechanical properties of slags, apart from economic aspects, are undoubtedly an asset when deciding to use them instead of natural raw materials. In addition to the above, there is also the ecological aspect, since by using waste materials, the environmental interference that occurs during the opencast mining of natural aggregates is reduced. S pecifically, this means waste utilization through secondary management.
However, it should be kept in mind that it is a material which quite easily and quickly responds to environmental changes triggered by external factors; therefore, along with the determination of its physical and mechanical properties, its phase and chemical composition must be also checked.
The studies showed that the predominant component of the blast furnace slag is glass which can amount up to 80%. In its vicinity, metallic precipitate as well as crystallites of periclase, dicalcium silicates and quartz can be found. With regard to the chemical composition of the slag, it was concluded that it meets the environmental and technical requirements regarding unbound and hydraulically bound mixtures. In case of the latter, in terms of its chemical composition, the slag meets the hydraulic activity category CA3. It also meets the chemical requirements for using it as a valuable addition to mortars and concretes, and it is useful in the production of CEM II Portland-composite cement, CEM III blast-furnace cement and CEM V composite cements. The blast furnace slag is a valuable raw material for cement production. Cement CEM III/C contains 81–95% of blast furnace slag in accordance with E N 197-1:2012. In 2019, the Polish cement industry used 1,939,387.7 tons of slag.
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Authors and Affiliations

Iwona Jonczy
1
ORCID: ORCID
Bartłomiej Grzesik
2
ORCID: ORCID
Andrzej Norbert Wieczorek
1
Anna Gerle
3
Paweł Nuckowski
4
Marcin Staszuk
4
ORCID: ORCID

  1. Silesian University of Technology, Faculty of Mining, Safety Engineering and Industrial Automation, Gliwice, Poland
  2. Silesian University of Technology, Faculty of Civil Engineering, Gliwice, Poland
  3. Łukasiewicz Research Network, Institute of Ceramics and Building Materials, Refractory Materials Division in Gliwice, Poland
  4. Silesian University of Technology, Faculty of Mechanical Engineering, Gliwice, Poland
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Abstract

Energy transition is a process that affects entire regions, not only reducing the prevailing socio- -economic conditions but most importantly, creating a new framework of functioning for their inhabitants. The changes that are taking place can be described as territorial stresses, which are factors that affect not only the psychological well-being of residents but also the economic, demographic, technological and ecological conditions of the regions. The article presents the partial results of research work conducted within the EN TRAN CES project. The authors compare two carbon-intensive regions: Kraków Metropolitan Area (high air pollution area) and Silesia (coal mining area). Comparing the results of the two components and thus the research methods: - the identification and systematization of the socio-cultural stress situation (a component describing events relevant to the transformation of the regions from 1945–2022 and the sparing of its significance on the development conditions in the regions; - the assessment of the adaptive capacity of the residents based on their attachment to the place, individual adaptation strategies for resolving tensions and the level of life satisfaction (socio-psychological component).
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Authors and Affiliations

Wit Hubert
1
ORCID: ORCID
Wojciech Kowalik
2
ORCID: ORCID
Aleksandra Komorowska
1
ORCID: ORCID
Dominik Kryzia
1
ORCID: ORCID
Monika Pepłowska
1
ORCID: ORCID
Lidia Gawlik
1
ORCID: ORCID

  1. Mineral and Energy Economy Research Institute PAS, Kraków, Poland
  2. AGH University of Krakow, Kraków, Poland
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Abstract

The exact measurement of multiphase flow is an important and essential task in the oil and petrochemical related industries. Several methods have already been proposed in this field. In the existing methods, flow rate measurement depends on the fluid flow pattern. Flow pattern recognition requiring calibration has created instability in such systems. In this paper, a imple and reliable method is proposed which is based on ultrasonic tomography. It is free from calibration and instability problems that existing methods have. The obtained data from a 32-digit array of ultrasonic sensors have been used and the two-phase flow rate including liquid and gas phases have been calculated through a simple algebraic algorithm. Simulation results show that while applying this method the measurement technique is independent from the fluid flow pattern and the system error is decreased. For the proposed algorithm, the average amount of the spatial imaging error (SIE) for a bubble at different positions inside the pipe is about 5%.

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Authors and Affiliations

Omid Qorbani
Esmaeil Najafi Aghdam
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Abstract

When designing injectable scaffolds for biomedical applications, it is crucial to determine the conditions for the formation of unlimited structures, in particular the kinetics at constant temperature. Despite many studies, these conditions have not been characterized so far after injection, which is such an important application aspect. The aim of the research is to discuss the impact of the injection application on the polymer structure and to propose new criteria for assessing the potential of thermosensitive biopolymer sols, considering the flow under high shear rates during the administration.
Based on the analysis of the obtained results of rheological tests, it was shown that the flow through the needles causes a significant change in the elastic properties that define the polymer structure, with almost unchanged viscous properties. As a consequence, the parameters characterizing the polymer coil change, which, combined with the quantitatively proven fragmentation, indicates that injection application may affect the size of the coils that will not reach the critical size of the aggregating nucleus.
Finally, extended research procedures for the conscious design of injectable scaffolds are proposed as well as key rheological parameters to ensure thermoinduced aggregation preceded by shear during injection are provided.
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Authors and Affiliations

Anna Rył
1
ORCID: ORCID
Piotr Owczarz
1
ORCID: ORCID

  1. Department of Chemical Engineering, Lodz University of Technology, Wolczanska 213, 93-005 Lodz
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Abstract

To obtain anti-corrosive thermo-diffusion zinc coatings, the authors use highly effective zinc saturating mixtures. This technology makes it possible to obtain coatings with a high zinc content in the δ-phase as well as a zinc-rich phase of FeZn13 (ζ-phase) on the coating surface. As a result of long-term studies into the corrosion properties of thermo-diffusion zinc (TDZ) coatings conducted by the authors, a number of features of their corrosive behavior have been established. The corrosion rate of those coatings in desalted and chloride-containing media is lower than those of galvanic or hot-dip zinc coatings. The corrosion behavior depends on the content of zinc on the surface and the texture features of the coating. The results showed that on the surface of thermo-diffusion coatings in the corrosion on media containing chloride ions, zinc hydroxychloride (simonkolleite – Zn5Cl2[OH]8[H2O]) has been formed. Compared to coatings obtained by other methods, the rate of simonkolleite formation was higher on TDZ coatings, which might have a positive effect on their resistance in aggressive atmospheres.

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Authors and Affiliations

A. Biryukov
R. Galin
D. Zakharyevich
A. Wassilkowska
A. Kolesnikov
T. Batmanova
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Abstract

Processing of metal alloys in semi-solid state is a way of producing many near net-shape parts and nowadays is commercially successful. Particular behaviour of alloys in the partially liquid state, having non-dendritic microstructure, is a base for thixoforming processing. Processing materials in the semi-solid state concerns alloys with relatively wide solidification range. Thermodynamic modelling can be used as a one of a potential tools that allow to identify alloys with proper temperature range. It means that the key feature of alloys suitable for thixoforming is a widely enough melting range, allowing for precise control of material temperature. The data gathered from thermodynamics calculations can also pay off in the industrial thixoforming processes design. The goal of this paper is to identify copper alloys which can be successfully shaped in the semi-solid state. Apart to thermodynamic calculations, the observations on high temperature microscope was carried out. During experiments the solidus, liquidus and also deformation temperatures can be determined. An experimental work allows confirming results obtained within the confines of thermodynamic calculations and firstly to determine the deformation temperatures which are the optimal for shaping processes. The basic achievement of this work is an identification of copper alloy groups possible for shaping in the semi-solid state. At the first part of the paper, the basic criteria of suitable alloys were described. Next, both the solid fraction curves for copper alloys with different alloying elements using ProCAST software and the phase diagrams were determined to identify the solidification temperature ranges of these alloys. In the second part of these paper, the identification of the deformation temperatures was carried out with use of high temperature microscope observation.
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Authors and Affiliations

A. Madetko
1
ORCID: ORCID
K. Sołek
1
ORCID: ORCID
P. Drożdż
1
ORCID: ORCID

  1. AGH University of Science and Technology, Faculty of Metals Engineering and Industrial Computer Science, al. Mickiewicza 30, 30-059 Krakow, Poland
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Abstract

Effect of Cu addition on oxide growth of Al-7 mass%Mg alloy at high temperature was investigated. As-cast microstructures of Al-7 mass%Mg and Al-7 mass%Mg-1 mass%Cu alloys showed α-Al dendrites and area of secondary particles. The 1 mass%Cu addition into Al-7 mass%Mg alloy formed Mg32(Al, Cu)49 ternary phase with β-Al3Mg2. The total fraction of two Mg-containing phases in Cu-added alloy was higher than the β-Al3Mg2 fraction in Cu-free alloy. From measured weight gains depending on time at 500°C under an air atmosphere, it was shown that all samples exhibited significant weight gains depending on time. Al-7mass%Mg-1mass%Cu alloy showed the relatively increased oxidation rate when compared with Cu-free alloy. All the oxidized cross-sections throughout the entire oxidation time showed coarse and dark areas regarded as oxides grown from the surface to inside, but bigger oxidized areas were formed in the Al-7mass%Mg-1mass%Cu alloy containing higher fraction of Mg-based phases in the as-cast microstructure. As a result of compositional analysis on the oxide clusters, it was found that the oxide clusters contained Mg-based oxides formed through internal oxidation during a long time exposure to oxidizing environments.
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Bibliography

[1] J.R. Davis, ASM International, Aluminum and Aluminum Alloys, Materials Park 1993.
[2] H. Watanabe, K. Ohori, Y. Takeuchi, Trans. Iron Steel Inst. Jpn. 27, 730 (1987).
[3] J.L. García-Hernández, C.G. Garay-Reyes, I.K. Gómez-Barraza, M.A. Ruiz-Esparza-Rodríguez, E.J. Gutiérrez-Castañeda, I. Estrada-Guel, M.C. Maldonado-Orozco, R. Martínez-Sánchez, J. Mater. Res. Technol. 8 (6), 5471 (2019).
[4] M . Mihara, C.D. Marioara, S.J. Andersen, R. Holmestad, E. Kobayashi, T. Sato, Mater. Sci. Eng. A, 658, 91 (2016).
[5] S.H. Ha, B.H. Kim, Y.O. Yoon, H.K. Lim, T.W. Lee, S.H. Lim, S.K. Kim, Int. J. Metalcast. 13, 121 (2019).
[6] G. Wu, K. Dash, M.L. Galano, K.A.Q. O’Reilly, Corros. Sci. 155, 97 (2019).
[7] B.H. Kim, S.H. Ha, Y.O. Yoon, H.K. Lim, S.K. Kim, D.H. Kim, Mater. Lett. 228, 108 (2018).
[8] H. Okamoto, J. Phase Equilibria 19, 598 (1998).
[9] T.S. Parel, S.C. Wang, M. J. Starink, Mater. Des. 31, S2 (2010).
[10] C.W. Bale, E. Bélisle, P. Chartrand, S.A. Decterov, G. Eriksson, A.E. Gheribi, K. Hack, I.H. Jung, Y.B. Kang, J. Melançon, A.D. Pelton, S. Petersen, C. Robelin, J. Sangster, P. Spencer, M.A. Van Ende, Calphad 54, 35 (2016).
[11] S.H. Ha, B.H. Kim, Y.O. Yoon, H.K. Lim, T.W. Lee, S.H. Lim, S.K. Kim, Sci. Adv. Mater. 10, 697 (2018).
[12] D . Ajmera, E. Panda, Corros. Sci. 102, 425 (2016).
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Authors and Affiliations

Seong-Ho Ha
1
ORCID: ORCID
Abdul Wahid Shah
1
ORCID: ORCID
Bong-Hwan Kim
1
ORCID: ORCID
Young-Ok Yoon
1
ORCID: ORCID
Hyun-Kyu Lim
1
ORCID: ORCID
Shae K. Kim
1
ORCID: ORCID

  1. Korea Institute of Industrial Technology (KITECH), Advanced Materials and Process R&D Department, Incheon 21999, Republic of Korea
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Abstract

Influence of Si addition on oxide layer growth of Al-6 mass%Mg alloys in molten state was investigated in this study. After melt holding for 24 h, the melt surface of only Si-free alloy became significantly bumpy, while no considerably oxidized surface was observed even with 1 mass%Si addition. There was no visible change on the appearance of melt surfaces with increasing Si content. As a result of compositional analysis on the melt samples between before and after melt holding, the Si-added alloys nearly maintained their Mg contents even after the melt holding for 24 h. On the other hand, the Mg content in the Si-free alloy showed a great reduction. The bumpy surface on Si-free alloy melt showed a large amount of pores and oxide clusters in its cross-section, while the Si-added alloy had no significantly grown oxide clusters on the surfaces. As a result of compositional analysis on the surfaces, the oxide clusters in Si-free alloy contained a great amount of Mg and oxygen. The oxide layer on the Si-added alloy was divided into Mg-rich and Mg-poor areas and contained certain amounts of Si. Such a mixed oxide layer containing Si would act as a protective layer during the melt holding for a long duration.
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Bibliography

[1] J.R. Davis, ASM International, Aluminum and Aluminum Alloys, Materials Park 1993.
[2] G . Wu, K. Dash, M.L. Galano, K.A.Q. O’Reilly, Corros. Sci. 155, 97 (2019).
[3] B.H. Kim, S.H. Ha, Y.O. Yoon, H.K. Lim, S.K. Kim, D.H. Kim, Mater. Lett. 228, 108 (2018).
[4] S.H. Ha, B.H. Kim, Y.O. Yoon, H.K. Lim, T.W. Lee, S.H. Lim, S.K. Kim, Sci. Adv. Mater. 10, 697 (2018).
[5] D . Ajmera, E. Panda, Corros. Sci. 102, 425 (2016).
[6] N. Smith, A. Kvithyld, G. Tranell, Metall. Mater. Trans. B 49, 2846 (2018).
[7] S.H. Ha, B.H. Kim, Y.O. Yoon, H.K. Lim, T.W. Lee, S.H. Lim, S.K. Kim, Int. J. Metalcast. 13, 121 (2019).
[8] J. Jeong, J. Im, K. Song, M. Kwon, S.K. Kim, Y.B. Kang, S.H. Oh, Acta Mater. 61, 3267 (2013).
[9] F . Zarei, H. Nuranian, K. Shirvani, Surf. Coat. Technol. 394, 125901 (2020).
[10] Y.L. Zhang, J. Li, Y.Y. Zhang, D.N. Kang, J. Alloys Compd. 827, 154131 (2020).
[11] W. Kai, P.C. Kao, P.C. Lin, I.F. Ren, J.S.C. Jang, Intermetallics 18, 1994 (2010).
[12] S.H. Ha, B.H. Kim, Y.O. Yoon, H.K. Lim, S.K. Kim, Sci. Adv. Mater. 10, 694 (2018).
[13] C.W. Bale, E. Bélisle, P. Chartrand, S.A. Decterov, G. Eriksson, A.E. Gheribi, K. Hack, I.H. Jung, Y.B. Kang, J. Melançon, A.D. Pelton, S. Petersen, C. Robelin, J. Sangster, P. Spencer, M.A. Van Ende, Calphad 54, 35 (2016).
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Authors and Affiliations

Young-Ok Yoon
1
ORCID: ORCID
Seong-Ho Ha
1
ORCID: ORCID
Abdul Wahid Shah
1
ORCID: ORCID
Bong-Hwan Kim
1
ORCID: ORCID
Hyun-Kyu Lim
1
ORCID: ORCID
Shae K. Kim
1
ORCID: ORCID

  1. Korea Institute of Industrial Technology (KITECH), Advanced Materials and Process R&D Department, Incheon 21999, Republic of Korea
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Abstract

In this work, a new supplementary formula was introduced to modify the Kerner model. This supplementary formula enable the Kerner model to predict the thermal expansion coefficient of multi-phase reinforced composites by normalization of the thermal expansion coefficient, bulk modulus, and shear modulus of the reinforcements. For comparison, the modified Kerner model as well as modified Schapery, the rule of mixtures, and Turner models were used to predict the thermal expansion coefficient of multi-phase reinforced composites 6092 Aluminum Alloy/silicon carbide/β-eucryptite. The results confirm the robustness of the modified Kerner model for predicting the thermal expansion coefficient of composites with multi-phase near-spherical inclusions. It may provide a fine selection to predict the thermal expansion coefficient of multi-phase reinforced metal matrix composites which cannot predict efficiently before.
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Authors and Affiliations

Shihao Zhang
1 2
ORCID: ORCID
Qinglin Hou
1
ORCID: ORCID
H.Y. Jiang
1 2
ORCID: ORCID

  1. Hunan University of Technology, School of Packaging and Materials Engineering, Zhuzhou 412007, China
  2. Hunan University of Technology, National & Local Joint Engineering Research Center for Advanced Packaging Material and Technology, Zhuzhou 412007, China
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Abstract

Mn-Al alloys are important alloys due to their magnetic properties and have been identified as permanent magnets. This alloy possesses magnetic properties and can be manufactured at a relatively low cost. Mn-Al alloys could be an alternative to rare earth magnets and hard ferrites and have a promising future. In this study, the effects of sintering temperature, holding time and pressure on densification, average grain size and magnetic properties of the SPS-ed Mn-Al alloys were observed. However, with the different sintering parameters, the magnetic phase τ phase could be achieved. To obtain the τ phase, different annealing methods were tried, yet samples heated to 650°C and air cooled exhibited magnetic properties. This sample was selected from various sintering parameters due to its high density of 99% N6 (800°C – 300 sec – 60 MPa) and has an average grain size of 137±18.1 µm. The uniqueness of this work is that statistical approaches such as Taguchi design of experiment (DOE) and regression were used for optimization of the manufacturing process.
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Authors and Affiliations

Can Burak Danisman
1
ORCID: ORCID
Gultekin Goller
1
ORCID: ORCID

  1. Istanbul Technical University, Department of Metallurgical and Materials Engineering, Istanbul, 34469, Turkey
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Abstract

The use of foam fractionation followed by aqueous two-phase extraction has emerged as a potential alternative to traditional liquid chromatography, hitherto irreplaceable in the purification of phycobiliproteins. The crude extracts of C-phycocyanin and allophycocyanin were obtained after Thermosynechococcus PCC 6715 biomass disintegration. The FF process with air flow of 2.4 L·h -1 resulted in purification factors up to 1.47 and partitioning coefficients of about 39, and did not require the addition of surfactants. A temperature of 35˚C allowed for the highest partitioning coefficient of 67.6 and yield of 76%; however, the purity of C-PC in condensate at this temperature was lower than at 25˚C. ATPE was tested in 20 different systems consisting of polyethylene glycol and phosphate or citrate salts, of which PEG1500-citrate gave the highest purification factor value of 2.31. Conversely, a partitioning coefficient of 2416 and 1094 were obtained for the PEG1500-phosphate and PEG3000-phosphate systems, respectively. Interestingly, the use of FF condensate in subsequent ATPE step resulted, for the first time, in the separation of the polymer phase into two fractions, one contained C-phycocyanin and the other allophycocyanin. It can be concluded that the use of a two-step system of FF and ATPE is a viable way to separate phycobiliproteins.
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Authors and Affiliations

Anna Antecka
1
ORCID: ORCID
Rafał Szeląg
1
Stanisław Ledakowicz
1
ORCID: ORCID

  1. Lodz University of Technology, Faculty of Process and Environmental Engineering, Department of Bioprocess Engineering, Wolczanska 213, 93-005 Lodz, Poland
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Abstract

This paper introduces a novel approach to building network cluster structures, based on the modified LEACH algorithm. The proposed solution takes into account the multitasking of the network infrastructure, resulting from various functions performed by individual nodes. Therefore, instead of a single head, dedicated to a given cluster, a set of heads is selected, the number of which corresponds to the number of performed functions. Outcomes of simulations, comparing the classical and the multifunctional approach, are presented. The obtained results confirm that both algorithms deliver similar levels of energy consumption, as well as efficiency in terms of the number of individual nodes discharged.
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Authors and Affiliations

A. Paszkiewicz
1
ORCID: ORCID
C. Ćwikła
2
M. Bolanowski
1
ORCID: ORCID
M. Ganzha
3
ORCID: ORCID
M. Paprzycki
3
ORCID: ORCID
M. Hodoň
4
ORCID: ORCID

  1. Department of Complex Systems, Rzeszow University of Technology, Al. Powstańców Warszawy 12, Rzeszów 35-959, Poland
  2. Rzeszow University of Technology, Al. Powstańców Warszawy 12, Rzeszów 35-959, Poland
  3. Systems Research Institute Polish Academy of Sciences, Newelska 6, Warszawa 01-447, Poland
  4. Department of Technical Cybernetics, University of Žilina, Univerzitná 8215/1, 010 26 Žilina, Slovakia
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Abstract

Although the phenomenon of otoacoustic emission has been known for nearly 30 years, it has not been fully explained yet. One kind of otoacoustic emission is distortion product of the otoacoustic emission (DPOAE). New aspects of this phenomenon are constantly discovered and attempts are made to interpret correctly the obtained results. This paper discusses a new method of measuring DPOAE signals based on double phase-sensitive detection, which makes possible a real-time measurement of the DPOAE signal amplitude and phase. The method was applied for measurements of DPOAE signals in guinea pigs. Sample records are presented and the obtained results are discussed.

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Authors and Affiliations

Wojciech Michalski
Marek Bochnia
Wojciech Dziewiszek

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