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Number of results: 34
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Abstract

Extremely intense development of civilization requires from foundry casting technologies very high quality and not expensive castings. In

the foundries, there are many treatments that allow increasing of the final properties of produced castings such as refining, modification,

heat treatment, etc. One of the methods of increasing the quality of the casting by removing inclusions from the liquid alloy is filtration.

The use of ceramic-carbon foam filters in filtration process is still analysed phenomenon that allows improving the final properties of

castings. A modern method of research, testing and synthesis of innovative chemical compositions allows improving the properties of such

filters. In the paper the evaluation of application properties of developed ceramic-carbon bonded foam filters is presented. The quality of

the foam filters is evaluated by Computer Tomography and foundry trials in pouring of liquid metal in test molds. Additionally computer

simulations were made to visualize the flow characteristics in the foam filter. The analysed filters are the result of the research work of

Foundry Research Institute and the Institute of Ceramics and Building Materials, Refractory Materials Department in Gliwice.

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Authors and Affiliations

A. Karwiński
P. Wieliczko
M. Małysza
A. Gil
B. Lipowska
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Abstract

Authors paid attention to anatomy and clinical implications which are associated with the variations of the sphenoid sinus. We discuss also anatomical structure of the sphenoid bone implementing clinical application of this bone to diff erent invasive and miniinvasive procedures (i.e. FESS).

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Authors and Affiliations

Joanna Jaworek-Troć
Michał Zarzecki
Anna Bonczar
Lourdes N. Kaythampillai
Bartosz Rutowicz
Małgorzata Mazur
Jacenty Urbaniak
Wojciech Przybycień
Katarzyna Piątek-Koziej
Marcin Kuniewicz
Marcin Lipski
Wojciech Kowalski
Janusz Skrzat
Marios Loukas
Jerzy Walocha
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Abstract

The paper presents the development procedures for both virtual 3D-CAD and material models of fractured segments of human spine formulated with the use of computer tomography (CT) and rapid prototyping (RP) technique. The research is a part of the project within the framework of which a database is developed, comprising both 3D-CAD and material models of segments of thoracic-lumbar spine in which one vertebrae is subjected to compressive fracture for a selected type of clinical cases. The project is devoted to relocation and stabilisation procedures of fractured vertebrae made with the use of ligamentotaxis method. The paper presents models developed for five patients and, for comparison purposes, one for a normal spine. The RP material models have been built basing on the corresponding 3D-CAD ones with the use of fused deposition modelling (FDM) technology. 3D imaging of spine segments in terms of 3D-CAD and material models allows for the analysis of bone structures, classification of clinical cases and provides the surgeons with the data helpful in choosing the proper way of treatment. The application of the developed models to numerical and experimental simulations of relocation procedure of fractured vertebra is planned.

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Authors and Affiliations

Anna Dąbrowska-Tkaczyk
Anna Floriańczyk
Roman Grygoruk
Konstanty Skalski
Piotr Borkowski
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Abstract

The paper describes an innovative ultrasound imaging method called Doppler Tomography (DT), otherwise known as Continuous Wave Ultrasonic Tomography (CWUT). Thanks to this method, it is possible to image the tissue cross-section in vivo using a simple two-transducer ultrasonic probe and using the Doppler effect. It should be noted that DT significantly differs from the conventional ultrasound Doppler method of measuring blood flow velocity. The main difference is that when measuring blood flow, we receive information with an image of the velocity distribution in a given blood vessel (Nowicki, 1995), while DT allows us to obtain a cross-sectional image of stationary tissue structure. In the conventional method, the probe remains stationary, while in the DT method, the probe moves and the examined tissue remains stationary.

This paper presents a method of image reconstruction using the DT method. First, the basic principle of correlation of generated Doppler frequencies with the location of inclusions from which they originate is explained. Then the exact process and algorithm in this method are presented. Finally, the impact of several key parameters on imaging quality is examined. As a result, the conclusions of the research allow to improve the image reconstruction process using the DT method.

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Authors and Affiliations

Tomasz Świetlik
Krzysztof J. Opieliński
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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

Optical coherence tomography (OCT) – a kind of optical counterpart of ultrasound imaging – is continually being improved as image contrast boosting techniques are developed.

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Authors and Affiliations

Karol Karnowski
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Abstract

Computed tomography is opening up new possibilities for the diagnosis of coronary artery disease. If used routinely as a future screening method, it can detect the disease at a very early stage.
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Authors and Affiliations

Cezary Kępka
1

  1. Institute of Cardiology in Warsaw
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Abstract

During four Polish Geodynamical Expeditions to West Antarctica between 1979 and 1991, seismic measurements were made along 21 deep refraction profiles in the Bransfield Strait and along the coastal area of Antarctic Peninsula using explosion sources. Recordings were made by 16 land stations and 8 ocean bottom seismometers. Good quality recordings were obtained up to about 250 km distance. This allowed a detailed study of the seismic wave field and crustal structure. Three-dimensional tomographic inversion was carried out using first arriv­als from the complete data set including off-line recordings. As a result, we obtained a 3-D model of the P-wave velocity distribution in the study area. In the area adjacent to the Antarctic Peninsula coast, sedimentary cover of 0.2 to 3 km thickness was found, whereas in the shelf area and in the Bransfield Strait sedimentary basins with thickness from 5 to 8 km were observed. In the Bransfield Strait a high velocity body with Vp > 7.5 km/s was found at 12 km depth. The use of the off-line data allowed for determination of the horizontal extent of the body. The thickness of the crust varies from more than 35-40 km in the coastal area south of the Hero Fracture Zone to 30-35 km in the area of Bransfield Strait and South Shetland Islands and about 12 km in the Pacific Ocean NW of South Shetland Islands.

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Authors and Affiliations

Piotr Środa
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Abstract

New oil and natural gas deposits can be recognized using X-ray computed tomography (CT) technology, and their potential value can be evaluated using increasingly advanced computational methods.

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Authors and Affiliations

Paulina Krakowska
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Abstract

We present spectral emission characteristics from laser-plasma EUV/SXR sources produced by irradiation of < 1 J energy laser pulse on eleven different double stream gas puff targets, with most intense electronic transitions identified in the spectral range from 1 nm to 70 nm wavelength which corresponds to photon energy from 18 eV to 1240 eV. The spectra were obtained using grazing incidence and transmission spectro- graphs from laser-produced plasma emission, formed by the interaction of a laser beam with a double stream gas puff target. Laser pulses with a duration of 4 ns and energy of 650 mJ were used for the experiment. We present the results obtained from three different spectrometers in the wavelength ranges of SXR (1–5.5 nm), SXR/EUV (4–15.5 nm), and EUV (10–70 nm). In this paper, detailed information about the source, gas targets under investigation, the experimental setup, spectral measurements and the results are presented and discussed. Such data may be useful for the identification of adequate spectral emissions from gasses in the EUV and SXR wavelength ranges dedicated to various experiments (i.e. broadband emission for the X-ray coherence tomography XCT) or may be used for verification of magnetohydrodynamic plasma codes.

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Authors and Affiliations

Antony Jose Arikkatt
Przemysław Wachulak
Henryk Fiedorowicz
Andrzej Bartnik
Joanna Czwartos
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Abstract

This study was carried out to determine the morphometric and volumetric features of the mandible in Van cats by using computed tomography (CT) and a three-dimensional (3D) software program. The study also aimed at presenting the biometrical differences of these mea- surements between genders. A total of 16 adult Van cats (8 males, 8 females) were used in the study. The cats were anesthetized using a ketamine-xylazine combination. They were then scanned using CT under anesthesia and their images were obtained. The scanned images of the mandible in each cat were used for the reconstruction of a 3D model by using the MIMICS 20.1 (The Materialise Group, Leuven, Belgium) software program. Later, morphometric (17 parame- ters), volumetric, and surface area measurements were conducted and statistical analyses were carried out. In our morphometric measurements, it was found that TLM (total length of the mandible), PCD (pogonion to coronoid process distance), CAP (length from the indenta- tion between the condyle process and angular process to pogonion), CAC (length from the inden- tation between the condyle process and the angular process to back of alveole C1), CML (length between C1 - M1), RAH (ramus height), MDM (mandible depth at M1), MHP (height of the mandible in front of P3), and ABC (angular process to back of alveole C1 distance) were greater in male cats; while MWM (mandible width at M1 level) was greater in female cats and was statistically significant (p<0.05). The length and height of the mandible were 6.36±2.42 cm and 3.01±1.81 cm in male cats, respectively. On the other hand, in female cats, the length and height of the mandible were 5.89±2.57 cm and 2.71±1.26 cm, respectively. The volume of the mandible was measured to be 7.39±0.93 cm3 in male cats and 5.40±0.49 cm3 in female cats. The surface areas were 63.50±5.27 cm2 in male cats and 52.73±3.89 cm2 in female cats. In con- clusion, in this study, basic morphometric parameters of the mandible in adult Van cats were found by using CT and a 3D modeling program. The differences between male and female cats were also determined in the study.
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Authors and Affiliations

O. Yilmaz
1
İ. Demircioglu
2

  1. Department of Anatomy, Faculty of Veterinary Medicine, Van Yuzuncu Yil University, 65080, Van, Turkey
  2. Department of Anatomy, Faculty of Veterinary Medicine, Harran University, 63200, Şanlıurfa, Turkey
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Abstract

The study aimed touse3D computed tomography (CT) to analyse a joint between two dissimilar materials produced by friction stir welding (FSW). As the materials joined, i.e., aluminum and copper, differ in properties (e.g., density and melting point), the weld is predicted to have an inhomogeneous microstructure. The investigations involved applying microfocus computed tomography (micro-CT) to visualize and analyze the volumetric structure of the joint. Volume rendering is extremely useful because, unlike computer modelling, which requires many simplifications, it helps create highly accurate representations of objects. Image segmentation into regions was performed through global gray-scale thresholding. The analysis also included elemental mapping of the weld cross-sections using scanning electron microscopy (SEM) and examination of its surface morphology by means of optical microscopy (OP). The joint finds its use in developing elements used in the chemical, energetics and aerospace industries, due to the excellent possibilities of combining many different properties, and above all, reducing the weight of the structure.
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Bibliography

[1] Zhao, Y., You, J., Qin, J., Dong, C., Liu, L., Liu, Z. & Miao, S. (2022). Stationary shoulder friction stir welding of Al–Cu dissimilar materials and its mechanism for improving the microstructures and mechanical properties of joint. Materials Science & Engineering A 837, 142754. https://doi.org/10.1016/j.msea.2022.142754.
[2] Zhou, L., Li, G.H., Zhang, R.X., Zhou, W.L., He, W.X., Huang, Y.X. & Song, X.G. (2019). Microstructure evolution and mechanical properties of friction stir spot welded dissimilar aluminum-copper joint. Journal of Alloys and Compounds. 775(15), 372-382. https://doi.org/10.1016/ j.jallcom.2018.10.045.
[3] Tong, L., Xie, J.N., Liu, L., Chang, G. & Ojo, O.O. (2020). Microscopic appraisal and mechanical behavior of hybrid Cu/Al joints fabricated via friction stir spot welding-brazing and modified friction stir clinching-brazing. Journal of Materials Research and Technology. 9(6),13239-13249. https://doi.org/10.1016/j.jmrt.2020.09.042.
[4] Tian, W.H., Su, H. & Wu, C.S. (2020). Effect of ultrasonic vibration on thermal and material flow behavior, microstructure and mechanical properties of friction stir welded al/cu joints. International Journal of Advanced Manufacturing Technology. 107(1), 59-71. https://doi.org/10.1007/s00170-020-05019-0.
[5] Pilarczyk, J. (2005). Engineer's Handbook 2, Welding. Warszawa: Wydawnictwo Naukowo-Techniczne. (in Polish).
[6] Rajak, D.K., Pagar, D.D., Menezes, P.L. & Eyvazian, A. (2020). Friction-based welding processes: friction welding and friction stir welding. Journal of Adhesion Science and Technology. 34(24), 2613-2637. https://doi.org/10.1080/ 01694243.2020.1780716.
[7] Schneider, J., Chen, P. & Nunes, A.C. (2019). Entrapped oxide formation in the friction stir weld (FSW) process. Metallurgical and Materials Transactions A, 50, 257-270 https://doi.org/10.1007/s11661-018-4974-8.
[8] Rams, B., Pietras, A., & Mroczka K. (2014). Friction stir welding of elements made of cast aluminium alloys. Archives of Foundry Engineering. 59(1), 385-392.
[9] Martinsen, K., Hu, S.J. & Carlson, B.E. (2015). Joining of dissimilar materials. CIRP Annals. 64(2), 679-699. https://doi.org/10.1016/j.cirp.2015.05.006.
[10] Weman, K. (2011). Welding processes handbook. New York: Elsevier.
[11] Singh, R., Kumar, R., Feo, L., et al. (2016). Friction welding of dissimilar plastic/polymer materials with metal powder reinforcement for engineering applications. Composites Part B: Engineering. 101, 77-86. https://doi.org/10.1016/ j.compositesb.2016.06.082.
[12] Rajak, D.K., Pagar, D.D., Menezes, P.L., et al. (2019). Fiber-reinforced polymer composites: manufacturing, properties, and applications. Polymers. 11(10), 1667. https://doi.org/10.3390/polym11101667.
[13] Lee, H.S., Lee, Y.R., Min, K.J. (2016). Effects of friction stir welding speed on AA2195 alloy. In: MATEC Web of Conferences. Vol. 45, France: EDP Sciences.
[14] Ramnath, B.V., Subramanian, S.A., Rakesh, R. et al. (2018). A review on friction stir welding of aluminium metal matrix composites. In IOP Conference Series: Materials Science and Engineering. 8-9 March 2018. IOP Publishing; 012103.
[15] Bankowski, D., Spadlo, S. (2017). Vibratory tumbling of elements made of Hardox400 steel. In 26th International Conference on Metallurgy and Materials (pp. 725-730).
[16] Karrar, G., Galloway, A., Toumpis, A., Li, H.J. & Al-Badouc, F. (2020). Microstructural characterisation and mechanical properties of dissimilar aa5083-copper joints produced by friction stir welding. Journal of Materials Research and Technology. 9(5), 11968-11979. https://doi.org/10.1016/j.jmrt.2020.08.073.
[17] Galvao, I., Loureiro, A. & Rodrigues, D.M. (2016). Critical review on friction stir welding of aluminium to copper. Science and Technology of Welding and Joining. 21(7), 523-546. https://doi.org/10.1080/13621718.2015.1118813.
[18] Ouyang, J., Yarrapareddy, E. & Kovacevic, R. (2006). Microstructural evolution in the friction stir welded 6061 aluminum alloy (T6-temper condition) to copper. Journal of Materials Processing Technology. 172(1), 110-122. https://doi.org/10.1016/j.jmatprotec.2005.09.013.
[19] Mehta, K.P. & Badheka, V.J. (2016). A review on dissimilar friction stir welding of copper to aluminum: process, properties, and variants. Materials and Manufacturing Processes. 31(3), 233-254. https://doi.org/10.1080/10426914.2015.1025971.
[20] Cao, F.J., Li, J.P., Hou, W.T., Shen, Y.F., Ni, R. (2021). Microstructural evolution and mechanical properties of the friction stir welded Al Cu dissimilar joint enhanced by post-weld heat treatment. Materials Characterization. 174, 110998. https://doi.org/10.1016/j.matchar.2021.110998.
[21] Hou, W.T., Shen, Z.K., Huda, N., Oheil, M., Shen, Y.F., Jahed, H. & Gerlich, A.P. (2021). Enhancing metallurgical and mechanical properties of friction stir butt welded joints of Al–Cu via cold sprayed Ni interlayer. Materials Science and Engineering: A. 809, 140992. https://doi.org/10.1016/j.msea.2021.140992.
[22] Mao, Y., Ni, Y., Qin, X.D.P. & Li, F. (2020). Microstructural characterization and mechanical properties of micro friction stir welded dissimilar al/cu ultra-thin sheets. Journal of Manufacturing Processes. 60, 356-365. https://doi.org/10.1016/j.jmapro.2020.10.064.
[23] Patel, N.P., Parlikar, P., Dhari, R.S., Mehta, K. & Pandya, M. (2019). Numerical modelling on cooling assisted friction stir welding of dissimilar Al-Cu joint. Journal of Manufacturing Processes. 47, 98-109. https://doi.org/10.1016/j.jmapro.2019.09.020.
[24] Mehta, K.P. & Badheka, V.J. (2017). Hybrid approaches of assisted heating and cooling for friction stir welding of copper to aluminum joints. Journal of Materials Processing Technology. 239, 336-345. https://doi.org/10.1016/ j.jmatprotec.2016.08.037.
[25] You, J.Q., Zhao, Y.Q., Dong, C.L., Wang, C.G., Miao, S., Yi, Y.Y. & Hai, Y.H. (2020). Microstructure characteristics and mechanical properties of stationary shoulder friction stir welded 2219-t6 aluminium alloy at high rotation speeds. The International Journal of Advanced Manufacturing Technology. 108, 987-996. https://doi.org/10.1007/s00170-019-04594-1.
[26] Li, D.X., Yang, X.Q., Cui, L., He, F.Z. & Zhang, X. (2015). Investigation of stationary shoulder friction stir welding of aluminum alloy 7075-t651. Journal of Materials Processing Technology. 222, 391-398. https://doi.org/10.1016/ j.jmatprotec.2015.03.036.
[27] Depczynski, W., Spadlo, S., Mlynarczyk, P., Ziach, E., Hepner P. (2015). The selected properties of porous layers formed by pulse microwelding technique. In METAL 2015: 24TH International Conference on Metallurgy and Materials, 3 - 5 June 2015 (pp.1087-1092). Brno, Czech Republic.
[28] Bańkowski D. & Młynarczyk P. (2020). Visual testing of castings defects after vibratory machining. Archives of Foundry Engineering. 20(4), 72-76. DOI: 10.24425/afe.2020.133350.
[29] Mlynarczyk, P., Spadlo, S. (2016). The analysis of the effects formation iron - tungsten carbide layer on aluminum alloy by electrical discharge alloying process. In METAL 2016: 25th Anniversary International Conference on Metallurgy and Materials, 25 – 27 May 2016 (pp.1109-1114). Brno, Czech Republic.
[30] Depczynski, W. Jasionowski, R., Mlynarczyk, P. (2018). The impact of process variables on the connection parameters during pulse micro-welding of the H800 superalloy. In METAL 2018: 27TH International Conference on Metallurgy and Materials, 23 – 25 May 2018 (pp. 1506-1512). Brno, Czech Republic.
[31] Bankowski, D. & Spadlo, S. (2019). The use of abrasive waterjet cutting to remove flash from castings. Archives of Foundry Engineering. 19(3), 94-98. DOI: 10.24425/afe.2019.129617.
[32] Spadlo, S., Depczynski, W. & Mlynarczyk, P. (2017). Selected properties of high velocity oxy liquid fuel (HVOLF) - sprayed nanocrystalline WC-Co Infralloy(TM) S7412 coatings modified by high energy electric pulse. Metalurgija. 56(3-4), 412-414.
[33] Bonarski, J.T., Kania, B., Bolanowski, K. & Karolczuk, A. (2015). Utility of stress-texture characteristics of structural materials by X-ray. Archives of Metallurgy and Materials. 60(3), 2247-2252. DOI: 10.1515/amm-2015-0370.
[34] Jezierski, G. (1993). Industrial radiography. Warszawa: Wydawnictwa Naukowo-Techniczne. (in Polish).
[35] Cierniak, R. (2005). Computed tomography. Construction of CT devices. Reconstruction algorithms. Warszawa: Akademicka Oficyna Wydawnicza EXIT. (in Polish).
[36] Kielczyk, J. (2006). Industrial radiography. Wydawnictwo Gamma. (in Polish).
[37] Ratajczak, E. (2012). X-ray computed tomography (CT) for industrial tasks. Pomiary Automatyka Robotyka. 5, 104-113. (in Polish).
[38] Cullity, B.D. (1959). Elements of X-Ray diffraction. London: Addison-Wesley Publising Company. Inc.
[39] Axon, H.J., Hume-Rothery, W. (1948). Proc. R. Soc. (London), Ser. A 193, 1.
[40] Pearson, W.B. (1958).: ÑA Handbook of Lattice Spacings and Structures of Metals and Alloysì. Oxford: Pergamon Press.  
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Authors and Affiliations

Wojciech P. Depczyński
1
ORCID: ORCID
Damian Bańkowski
1
ORCID: ORCID
Piotr S. Młynarczyk
1
ORCID: ORCID

  1. Radiography and Computed Tomography Laboratory, Department of Metal Science and Manufacturing Processes, Faculty of Mechatronics and Mechanical Engineering, Kielce University of Technology, al. Tysiąclecia Państwa Polskiego 7, 25-314 Kielce, Poland
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Abstract

The aim of the investigation was liquid mixing time measurement in a laboratory scale stirred tank equipped with a metal Maxblend impeller and comparison with the corresponding mixing time obtained with other conventional impellers. The data are collected by Electrical Resistance Tomography, whose applicability in this case is non-trivial, because of the electrical interferences between the large paddles of the impeller and the measuring system. The raw data treatment methodology purposely developed for obtaining the homogenization dynamics curve is presented.Arobust approach for a fine and lowcost investigation of the mixing performances of close-clearance impellers in opaque systems is suggested. The analysis of the local and averaged conductivity time traces reveals the effect of important variables, such as the fluid viscosity and the vessel configuration, on the mixing time under various agitation conditions. The data collection and post processing procedures open the way to the application of the technique to multiphase and non-Newtonian fluids stirred with close-clearance impellers.
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Bibliography

Ameur H., 2015. Energy efficiency of different impellers in stirred tank reactors. Energy, 93, 1980–1988. DOI: 10.1016/j.energy.2015.10.084.
Ameur H., Bouzit M., Helmaoui M., 2012. Hydrodynamic study involving a maxblend impeller with yield stress fluids. J. Mech. Sci. Technol., 26, 1523–1530. DOI: 10.1007/s12206-012-0337-3.
Dickin F., Wang M., 1996. Electrical resistance tomography for process applications. Meas. Sci. Technol., 7, 247–260. DOI: 10.1088/0957-0233/7/3/005.
Fradette L., Thomé G., Tanguy P.A., Takenaka K., 2007. Power and mixing time study involving a Maxblend® impeller with viscous Newtonian and non-Newtonian fluids. Chem. Eng. Res. Des., 85, 1514–1523. DOI: 10.1205/cherd07051.
Grenville R.K., Nienow A.W., 2004. Blending of miscible liquids, In: Paul E.L., Atiemo-Obeng V.A., Kresta S.M. (Eds.). Handbook of industrial Mixing: Science and practice. John Wiley & Sons, Inc. Chapter 9, 507–542. DOI: 10.1002/0471451452.ch9.
Guntzburger Y., Fontaine A., Fradette L., Bertrand F., 2013. An experimental method to evaluate global pumping in a mixing system: Application to the Maxblend™for Newtonian and non-Newtonian fluids. Chem. Eng. J., 214, 394–406. DOI: 10.1016/j.cej.2012.10.041.
Hosseini S., Patel D., Ein-Mozaffari F., Mehrvar M., 2010. Study of solid-liquid mixing in agitated tanks through electrical resistance tomography. Chem. Eng. Sci., 65, 1374–1384. DOI: 10.1016/j.ces.2009.10.007.
Jairamdas K., Bhalerao A., Machado M.B., Kresta S.M., 2019. Blend time measurement in the confined impeller stirred tank. Chem. Eng. Technol., 42, 1594–1601. DOI: 10.1002/ceat.201800752.
Maluta F., Montante G., Paglianti A., 2020. Analysis of immiscible liquid-liquid mixing in stirred tanks by Electrical Resistance Tomography. Chem. Eng. Sci., 227, 115898. DOI: 10.1016/j.ces.2020.115898.
Mishra P., Ein-Mozaffari F., 2016. Using tomograms to assess the local solid concentrations in a slurry reactor equipped with a Maxblend impeller. Powder Technol., 301, 701–712. DOI: 10.1016/j.powtec.2016.07.007.
Montante G., Carletti C., Maluta F., Paglianti A., 2019. Solid dissolution and liquid mixing in turbulent stirred tanks. Chem. Eng. Technol., 42 (8), 1627–1634. DOI: 10.1002/ceat.201800726.
Montante G., Coroneo M., Paglianti A., 2016. Blending of miscible liquids with different densities and viscosities in static mixers. Chem. Eng. Sci., 141, 250–260. DOI: 10.1016/j.ces.2015.11.009.
Paglianti A., Carletti C., Montante G., 2017. Liquid mixing time in dense solid-liquid stirred tanks. Chem. Eng. Technol., 40, 862–869. DOI: 10.1002/ceat.201600595.
Patel D., Ein-Mozaffari F., Mehrvar M., 2013. Using tomography to characterize the mixing of non-Newtonian fluids with a Maxblend impeller. Chem. Eng. Technol., 36, 687–695. DOI: 10.1002/ceat.201200425.
Sharifi M., Young B., 2013. Electrical Resistance Tomography (ERT) applications to Chemical Engineering. Chem. Eng. Res. Des., 91, 1625–1645. DOI: 10.1016/j.cherd.2013.05.026.
Stobiac V., Fradette L., Tanguy P.A., Bertrand F., 2014. Pumping characterisation of the maxblend impeller for Newtonian and strongly non-Newtonian fluids. Can. J. Chem. Eng., 92, 729–741. DOI: 10.1002/cjce.21906.
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Authors and Affiliations

Suzuka Iwasawa
1
Honami Kubo
1
Katsuhide Takenaka
1
Sandro Pintus
2
Francesco Maluta
3
Giuseppina Montante
3
Alessandro Paglianti
3

  1. Sumitomo Heavy Industries Process Equipment Co., Ltd. 1501, Imazaike, Saijo City, Ehime, Japan
  2. Retired from University of Pisa, Via Giunta Pisano 28, 56126 Pisa, Italy
  3. Department of Industrial Chemistry, University of Bologna, viale Risorgimento 4,40136 Bologna, Italy
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Abstract

In this paper methods and their examination results for automatic segmentation and parameterization of vessels based on spectral domain optical coherence tomography (SD-OCT) of the retina are presented. We present three strategies for morphologic image processing of a fundus image reconstructed from OCT scans. A specificity of initial image processing for fundus reconstruction is analysed. Then, the parameterization step is performed based on the vessels segmented with the proposed algorithm. The influence of various methods on the vessel segmentation and fully automatic vessel measurement is analysed. Experiments were carried out with a set of 3D OCT scans obtained from 24 eyes (12 healthy volunteers) with the use of an Avanti RTvue OCT device. The results of automatic vessel segmentation were numerically compared with those prepared manually by the medical doctor experts.

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Authors and Affiliations

Tomasz Marciniak
ORCID: ORCID
Agnieszka Stankiewicz
Adam Dąbrowski
ORCID: ORCID
Marcin Stopa
Piotr Rakowicz
Elżbieta Marciniak
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Abstract

This article summarizes technical aspects of preparing printable 3D anatomical models created from radiological data (CT, MRI) and discusses their usefulness in surgery of the human skull. Interdisciplinary approach to the capabilities of the 3D printers, and the materials used for manufacturing 3D objects oriented on replicating anatomical structures has created new possibilities for simulating and planning surgical procedures in clinical practice settings.
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Bibliography

1. Ameil M., Delattre J.F., Cordobes B., Flament J.B.: Computerized reconstruction of an anatomical structure based on digitized sections. Anat Clin. 1984; 5 (4): 261–264. doi: 10.1007/BF01798749.
2. Vannier M.W., Marsh J.L., Warren J.O.: Three dimensional CT reconstruction images for craniofacial surgical planning and evaluation. Radiology. 1984; 150 (1): 179–184. doi: 10.1148/radiology.150.1.6689758.
3. Groth C., Kravitz N.D., Jones P.E, Graham J.W., Redmond W.R.: Three-dimensional printing technology. J Clin Orthod. 2014; 48 (8): 475–485. PMID: 25226040.
4. Onuh S.O., Yusuf Y.Y.: Rapid prototyping technology: applications and benefits for rapid product development. J Intell Manuf. 1999; 10 (3–4): 301–311. doi: 10.1023/ A:1008956126775.
5. Anderson J.R., Thompson W.L., Alkattan A.K, Diaz O., Klucznik R., Zhang Y.J., Britz G.W., Grossman R.G., Karmonik C.: Three-dimensional printing of anatomically accurate, patient specific intracranial aneurysm models. J Neurointerv Surg. 2016; 8: 517–520. doi: 10.1136/neurintsurg-2015-011686.
6. Anderl H., Zur Nedden D., Mühlbauer W., Twerdy K., Zanon E., Wicke K., Knapp R.: CT-guided stereolithography as a new tool in craniofacial surgery. Br J Plastic Surg. 1994; 47 (1): 60–64. doi: 10.1016/0007-1226(94)90121-x.
7. Eltorai A.E., Nguyen E., Daniels A.H.: Three-dimensional printing in orthopedic surgery. Orthopedics. 2015; 38 (11): 684–687. doi : 10.3928/01477447-20151016-05.
8. Hoch E., Tovar G.E., Borchers K.: Bioprinting of artificial blood vessels: current approaches towards a demanding goal. Eur J Cardiothorac Surg. 2014; 46 (5): 767– 778. doi: 10.1093/ejcts/ezu242.
9. Kamali P., Dean D., Skoracki R., Koolen P.G., Paul M.A., Ibrahim A.M., Lin S.J.: The current role of three-dimensional printing in plastic surgery. Plast Reconstr Surg. 2016; 137 (3): 1045–1055. doi: 10.1097/01.prs.0000479977.37428.8e.
10. VanKoevering K.K., Hollister S.J., Green G.E.: Advances in 3-dimensional printing in otolaryngology: a review. JAMA Otolaryngol Head Neck Surg. 2017; 143 (2): 178– 183. doi: 10.1001/jamaoto.2016.3002.
11. Pham D.L., Xu C., Prince J.L.: Current methods in medical image segmentation. Annu Rev Biomed Eng. 2000; 2 (1): 315–337. doi: 10.1146/annurev.bioeng.2.1.315.
12. Sharma N., Aggarwal L.M.: Automated medical image segmentation techniques. J Med Phys. 2010; 35 (1): 3–14. doi: 10.4103/0971-6203.58777.
13. Withey D.J., Koles Z.J.: A review of medical image segmentation: methods and available software. Int J Bioelectromagn. 2008; 10 (3): 125–148.
14. Pal N.R., Pal S.K.: A review on image segmentation techniques. Patt Rec. 1993; 26 (9): 1277–1294. doi: 10.1016/0031-3203(93)90135-J.
15. Sahoo P.K., Soltani S.A. Wong A.K.C.: A survey of thresholding techniques. Comput Vis Graph Im Proc. 1988; 41 (2): 233–260. doi: 10.1016/0734-189X(88)90022-9.
16. Winder J., Bibb R.: Medical rapid prototyping technologies: state of the art and current limitations for application in oral and maxillofacial surgery. J Oral Maxillofac Surg. 2005; 63 (7): 1006–1015. doi: 10.1016/j.joms.2005.03.016.
17. Fleiter T., Hoffmann R., Niemeier R., Claussen C.D.: Preoperative planning and follow-up with spiral CT and stereolithographic models in craniofacial surgery. In Advances in CT III. Springer, Berlin, Heidelberg 1994; 149–156.
18. Mankovich N.J., Cheeseman A.M., Stoker N.G.: The display of three-dimensional anatomy with stereolithographic models. J Digit Imaging. 1990; 3 (3): 200–203. doi: 10.1007/BF03167610.
19. Stoker G.N., Mankovich N.J., Valentino D.: Stereolithographic models for surgical planning: preliminary report. J Oral Maxillofac Surg. 1992; 50: 466–471. doi: 10.1016/ s0278-2391(10)80317-9.
20. Eppley B.L., Sadove A.M.: Computer-generated patient models for reconstruction of cranial and facial deformities. J Craniofac Surg. 1998; 9 (6): 548–556. doi: 10.1097/ 00001665-199811000-00011.
21. Müller A., Krishnan K.G., Uhl E., Mast G.: The application of rapid prototyping techniques in cranial reconstruction and preoperative planning in neurosurgery. J Craniofac Surg. 2003; 14 (6): 899–914. doi: 10.1097/00001665-200311000-00014.
22. Singare S., Yaxiong L., Dichen L., Bingheng L., Sanhu H., Gang L.: Fabrication of customised maxillo-facial prosthesis using computer-aided design and rapid prototyping techniques. Rapid Prototyp J. 2006; 12 (4): 206–213. doi: 10.1108/ 13552540610682714.
23. Kermer C., Lindner A., Friede I., Wagner A., Millesi W.: Preoperative stereolithographic model planning for primary reconstruction in craniomaxillofacial trauma surgery. J Craniomaxillofac Surg. 1998; 26 (3): 136–139. doi: 10.1016/s1010-5182(98) 80002-4.
24. Kernan B.T., Wimsatt J.A.: Use of a stereolithography model for accurate, preoperative adaptation of a reconstruction plate. J Oral Maxillofac Surg. 2000; 58 (3): 349– 351. doi: 10.1016/s0278-2391(00)90071-5.
25. Ehrenberg R.: Plastic implant replaces three-quarters of man’s skull. Science News. March 11, 2013.
26. Sunderland I.R., Edwards G., Mainprize J., Antonyshyn O.: A technique for intraoperative creation of patient-specific titanium mesh implants. Plast Surg (Oakv). 2015; 23 (2): 95–99. doi: 10.4172/plastic-surgery.1000909.
27. Bell R.B., Markiewicz M.R.: Computer-assisted planning, stereolithographic modeling, and intraoperative navigation for complex orbital reconstruction: a descriptive study in a preliminary cohort. J Oral Maxillofac Surg. 2009; 67 (12): 2559–2570. doi: 10.1016/j.joms.2009.07.098.
28. D’Urso P.S., Atkinson R.L., Lanigan M.W., Earwaker W.J., Bruce I.J., Holmes A., Barker T.M., Effeney D.J., Thompson R.G.: Stereolithographic (SL) biomodelling in craniofacial surgery. Br J Plast Surg. 1998; 51 (7): 522–530. doi: 10.1054/ bjps.1998.0026.
29. D’Urso P.S., Redmond M.J.: A method for the resection of cranial tumours and skull reconstruction. Br J Neurosurg. 2000; 14 (6): 555–559. doi: 10.1080/ 02688690020005581.
30. Erickson D.M., Chance D., Schmitt S., Mathis J.: An opinion survey of reported benefits from the use of stereolithographic models. J Oral Maxillofac Surg. 1999; 57 (9): 1040–1043.
31. Cui J., Chen L., Guan X., Ye L., Wang H., Liu L.: Surgical planning, three-dimensional model surgery and preshaped implants in treatment of bilateral craniomaxillofacial post-traumatic deformities. J Oral Maxillofac Surg. 2014; 72 (6): 1138-e1-14. doi: 10.1016/j.joms.2014.02.023.
32. Frühwald J., Schicho K.A., Figl M., Benesch T., Watzinger F., Kainberger F.: Accuracy of craniofacial measurements: computed tomography and three-dimensional computed tomography compared with stereolithographic models. J Craniofac Surg. 2008; 19 (1): 22–26. doi: 10.1097/scs.0b013e318052ff1a.
33. Choi J.Y., Choi J.H., Kim N.K., Kim Y., Lee J.K., Kim M.K., Lee J.H., Kim M.J.: Analysis of errors in medical rapid prototyping models. Int J Oral Maxillofac Surg. 2002; 31.(1): 23–32. doi: 10.1054/ijom.2000.0135.
34. Barker T.M., Earwaker W.J., Lisle D.A.: Accuracy of stereolithographic models of human anatomy. Australas Radiol. 1994; 38 (2): 106–111. doi: 10.1111/j.1440-1673.1994.tb00146.x.
35. Chang P.S., Parker T.H., Patrick C.W., Miller M.J.: The accuracy of stereolithography in planning craniofacial bone replacement. J Craniofac Surg. 2003; 14 (2): 164–170. doi: 10.1097/00001665-200303000-00006.
36. Nizam A., Gopal R., Naing N.L., Hakim A.B., Samsudin A.R.: Dimensional accuracy of the skull models produced by rapid prototyping technology using stereolithography apparatus. Arch Orofac Sci. 2006; 1: 60–66.
37. Chia H.N., Wu B.M.: Recent advances in 3D printing of biomaterials. J Biol Eng. 2015; 9 (1): 4. doi: 10.1186/s13036-015-0001-4.
38. Hsieh T.Y., Dedhia R., Cervenka B., Tollefson T.T.: 3D Printing: current use in facial plastic and reconstructive surgery. Curr Opin Otolaryngol Head Neck Surg. 2017; 25 (4): 291–299. doi: 10.1097/MOO.0000000000000373.
39. Jakus A.E., Rutz A.L., Shah R.N.: Advancing the field of 3D biomaterial printing. Biomed Mater. 2016; 11 (1): 014102. doi: 10.1088/1748-6041/11/1/014102.
40. Poukens J., Haex J., Riediger D.: The use of rapid prototyping in the preoperative planning of distraction osteogenesis of the cranio-maxillofacial skeleton. Comput Aided Surg. 2003; 8 (3): 146–154. doi: 10.3109/10929080309146049.
41. Wang Y., Ni M., Tang P.F., Li G.: Novel application of HA-TCP biomaterials in distraction osteogenesis shortened the lengthening time and promoted bone consolidation. J Orthop Res. 2009; 27 (4): 477–482. doi: 10.1002/jor.20782.
42. Ballard D.H., Trace A.P., Ali S., Hodgdon T., Zygmont M.E., DeBenedectis C.M., Smith S.E., Richardson M.L., Patel M.J., Decker S.J., Lenchik L.: Clinical Applications of 3D Printing: Primer for Radiologists. Acad Radiol. 2018; 25 (1): 52–65. doi: 10.1016/j.acra.2017.08.004.
43. Chepelev L., Giannopoulos A., Tang A., Mitsouras D., Rybicki F.J.: Medical 3D printing: methods to standardize terminology and report trends. 3D Print Med. 2017; 3 (1): 4. doi: 10.1186/s41205-017-0012-5.
44. Bauermeister A.J., Zuriarrain A., Newman M.I.: Three-dimensional printing in plastic and reconstructive surgery: a systematic review. Ann Plast Surg. 2016; 77 (5): 569– 576. doi: 10.1097/SAP.0000000000000671.
45. Pham D.L., Xu C., Prince J.L.: Current methods in medical image segmentation. Annu Rev Biomed Eng. 2000; 2 (1): 315–337. doi: 10.1146/annurev.bioeng.2.1.315.
46. Waran V., Devaraj P., Hari Chandran T., Muthusamy K.A., Rathinam A.K., Balakrishnan Y.K., Tung T.S., Raman R., Rahman Z.A.: Three-dimensional anatomical accuracy of cranial models created by rapid prototyping techniques validated using a neuronavigation station. J Clin Neurosci. 2012; 19 (4): 574–577. doi: 10.1016/j.jocn.2011.07.031.
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Authors and Affiliations

Janusz Skrzat
1

  1. Department of Anatomy, Jagiellonian University Medical College, Kraków, Poland
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Abstract

Appropriate design in linear construction depends on many factors, including detailed geological conditions. One of the biggest problems are unrecognized erosion forms, in particular karst ones, which have a huge impact on the design and subsequent operation of roads. For this purpose, in addition to conventional methods such as drilling or geotechnical probing, which are point-based, non-invasive spatial geophysical methods are used. This article presents an example of the use of geoelectrical surveys, Electrical Resistivity Tomography (ERT) for the recognition of karst zones for linear investments. The article describes ERT investigations, which to some extent allows to identify dangerous karst phenomena occurring in the Lublin Upland (Poland), which are of great importance at the design stage of roads and in their further safe operation. Non-invasive geophysical research has been verified and confirmed by traditional geotechnical research, which confirms the effectiveness of their use. The Electrical Resistivity Tomography was used as a method providing a broader spectrum of knowledge on the spatial arrangement of soil layers in the subgrade of the planned road investments. It also enabled a more accurate, more detailed interpretation of geotechnical studies. The described geophysical investigations opens wide possibilities for their application to researchers. In the future, non-invasive methods have a chance to become as reliable as geotechnical methods, but this requires a lot of research to improve the effectiveness and accuracy of the interpretation of the obtained results.
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Authors and Affiliations

Maciej Maślakowski
1
ORCID: ORCID
Anna Lejzerowicz
1
ORCID: ORCID
Grzegorz Pacanowski
1
ORCID: ORCID
Rafał Kuszyk
2
ORCID: ORCID

  1. Warsaw University of Technology, Faculty of Civil Engineering, Al. Armii Ludowej 16, 00-637 Warsaw, Poland
  2. Polish Geological Institute – National Research Institute, Rakowiecka 4, 00-975 Warsaw, Poland
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Abstract

The reaction of alkalis with aggregate containing reactive forms of silica (ASR) plays a significant role in shaping the durability of concrete, as the strongly hygroscopic reaction products generated lead to internal stress, causing its expansion and cracking. This study presents an extended analysis of corrosive processes occurring in mortars with reactive natural aggregate from Poland, using computed tomography and scanning microscopy methods. Numerous cracks in the grains and the surrounding cementitious matrix were observed, indicating a high degree of advancement of corrosive processes. Over time, the proportion of pores with reduced sphericity increased, indicating ongoing degradation of the mortars. The usefulness of computed tomography in studying the progress of ASR was demonstrated. Scanning microscopy confirmed that the cause of mortar degradation is the formed ASR gel with a typical composition, located within the volume of reactive grains, cracks propagating into the cementitious matrix, and accumulated in air voids.
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Authors and Affiliations

Justyna Zapała-Sławeta
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Abstract

A numerical study and simulation of breast imaging in the early detection of tumors using the photoacoustic (PA) phenomenon are presented. There have been various reports on the simulation of the PA phenomenon in the breast, which are not in the real dimensions of the tissue. Furthermore, the different layers of the breast have not been considered. Therefore, it has not been possible to rely on the values and characteristics of the resulting data and to compare it with the actual state. Here, the real dimensions of the breast at threedimensional and different constituent layers have been considered. After reviewing simulation methods and software for different stages of the PA phenomenon, a single suitable platform, which is commercially available finite element software (COMSOL), has been selected for simulating. The optical, thermal, elastic, and acoustic characteristics of different layers of breast and tumor at radiated laser wavelength (800 nm) were accurately calculated or obtained from a reliable source. Finally, by defining an array of 32 ultrasonic sensors on the breast cup at the defined arcs of the 2D slices, the PA waves can be collected and transmitted to MATLAB software to reconstruct the images. We can study the resulting PA wave and its changes in more detail using our scenarios.
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Authors and Affiliations

Maryam Ahangar Darband
1
Esmaeil Najafi Aghdam
1
Arash Gharibi
2

  1. Department of Electrical Engineering, Sahand University of Technology, Tabriz, Iran
  2. Institute of Modern Physics, Shanxi Normal University, Linfen, China
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Abstract

The purpose of this work is to examine the possibility of using multi-angle conventional ultrasound B-mode scanning in efficient 3-D imaging. In the paper, the volume of an object is reconstructed from vertical projections registered at fixed angular positions of the multi-element linear ultrasonic probe rotated in relation to the object submerged in water. The possible configurations are: vertical lateral, vertical top or vertical bottom. In the vertical lateral configuration, the ultrasonic probe acquires 2-D images of object’s vertical cross-sections, turning around its lateral surface. In the vertical top or bottom configuration, the ultrasonic probe acquires 2-D images of the object’s vertical cross-sections, turning on the horizontal plane over the top or under the bottom surface of the object. The method of recording 3-D volume of an object’s structure and reconstruction algorithm have been designed. Studies show the method in the vertical top or bottom configuration could be successfully applied to the effective 3-D visualisation of the structure of the female breast in vivo as the new complement ultrasonic imaging modality in the prototype of the developed ultrasound tomography scanner.

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Authors and Affiliations

Maciej Sabiniok
Krzysztof J. Opieliński
Sylwia Lis
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Abstract

This paper presents the results of acoustic field distribution simulations for the 1024-element ultrasonic ring array intended for the diagnosis of female breast tissue with the use of ultrasound tomography. For the purpose of analysing data, all acoustic fields created by each elementary transducer were combined. The natural position of the focus inside the ultrasonic ring array was changed by altering activation time of individual transducers in sectors consisting of 32, 64, and 128 ultrasonic transducers. Manipulating the position of the focus inside the array will allow to concentrate the ultrasonic beam in a chosen location in the interior space of the ring array. The goal of this research is to receive the best possible quality of images of cross-sections of the female breast. The study also analysed the influence of the acoustic field distribution on the inclination of the beam. The results will enable to choose an optimal focus and an optimal number of activated transducers.

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Authors and Affiliations

Wiktor Staszewski
Tadeusz Gudra
Krzysztof J. Opieliński
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Abstract

A new technique of Mueller-matrix mapping of the birefringent structure of biological preparations of human organs tissues is suggested. The algorithms of reconstruction of average values and magnitude of fluctuations of the phase (birefringence) and amplitude (dichroism) of optically anisotropic structure of myocardium and connective tissue component of the vaginal wall histological section are proposed. The magnitudes and ranges of changes in the statistical moments of the 1st-4th order that characterize the distribution of average values and magnitude of fluctuations of birefringence and dichroism of the myocardium and connective tissue of the vaginal tissues histological sections were determined. Joint studies of distributions of the characteristics of phase and amplitude of the anisotropy of myocardium and connective tissue component of the vaginal wall tissues of different states were performed. The cases of various necrotic changes in the myocardium and pathological conditions of the vagina wall (prolapse of the genitals) are examined. Balanced accuracy of the method of Mueller-matrix polarization-phase and diffuse tomography of optically anisotropic polycrystalline networks in the differentiation of necrotic and pathological changes in human organs is determined.

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Authors and Affiliations

L. Trifonyuk
W. Baranowski
V. Ushenko
O. Olar
A. Dubolazov
Yu. Ushenko
B. Bodnar
O. Vanchulyak
L. Kushnerik
M. Sakhnovskiy
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Abstract

Ukraine is characterised by active natural hazards processes within different structural, tectonic and landscape zones. In Middle Dnieper basin region mass movement processes have great impact on people’s livelihoods and infrastructure. These processes occur on the slopes with different geological structure. The determining causes include lithologic and stratigraphic conditions, hydrogeological regime, structural and textural peculiarities of rocks and the geomorphology of the slopes. Landslide inventory database has been developed based on long-term observations of more than 400 landslides and landslide-prone areas. This paper takes efforts forward by combining different geological and geophysical methods to advance the current understanding of landslide phenomena and contributing towards a better informed assessment of landslide hazard and risk. The developed methodology is implemented in a test sites of Kyiv region, covering an area of 18.3 km2 situated in the Middle Dnieper basin. Electrical Resistivity Tomography, Self-Potential and Infrared Thermography techniques were employed to investigate the lithostratigraphic sequences, the geometry of landslide body and potential mass movement. The results presented here confirm the potential of using an integrated approach that combines different field data to better plan mitigation activities and measures for the effective land management. This study will be useful in increasing the safety aspects of the infrastructures and lives and also for planning of research and developmental activities.
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Bibliography

DAHLIN T. 1996. 2D resistivity surveying for environmental and engineering applications. First Break. Vol. 14. Iss. 7 p. 275–284. DOI 10.3997/1365-2397.1996014.
FOSTER C., GIBSON A., WILDMAN G. 2008. The new national Landslide Database and Landslide hazard assessment of Great Britain [online]. First World Landslide Forum. Tokyo, Japan 18–21 November 2008 p. 203–206. [Access 05.09.2020]. Available at: http://nora.nerc.ac.uk/4694/
FRODELLA W., FIDOLINI F., MORELLI S., PAZZI V. 2015. Application of Infrared Thermography for landslide mapping: the Rotolon DSGDS case study. Rendiconti Online della Società Geologica Italiana. No. 35 p. 144–147. DOI 10.3301/ROL.2015.85.
FRODELLA W., GIGLI G., MORELLI S., LOMBARDI L., CASAGLI N. 2017. Landslide mapping and characterization through Infrared Thermography (IRT): Suggestions for a methodological approach from some case studies. Remote Sensing. Vol. 9(12), 1281. DOI 10.3390/rs9121281.
FRODELLA W., MORELLI S., GIGLI G., CASAGLI N. 2014. Contribution of infrared thermography to the slope instability characterization. [online] Proceedings of World Landslide Forum 3. Beijing, China 2–6 June 2014. [Access 05.09.2020]. Available at: http://hdl.handle.net/11576/2690166
GARCÍA-RODRÍGUEZ M.J., MALPICA J.A., BENITO B., DIAZ M. 2008. Susceptibility assessment of earthquake-triggered landslides in El Salvador using logistic regression. Geomorphology. Vol. 95. Iss. 3 p. 172–191. DOI 10.1016/j.geomorph.2007.06.001.
GIGLI G., FRODELLA W., GARFAGNOLI F., MORELLI S., MUGNAI F., MENNA F., CASAGLI N. 2014. 3-D geomechanical rock mass characterization for the evaluation of rockslide susceptibility scenarios. Land-slides. Vol. 11 p. 131–140. DOI 10.1007/s10346-013-0424-2.
IVANIK O., SHEVCHUK V., KRAVCHENKO D., YANCHENKO V., SHPYRKO S., GADIATSKA K. 2019. Geological and geomorphological factors of natural hazards in Ukrainian Carpathians. Journal of Ecological Engineering. Vol. 20. Iss. 4 p. 177–186. DOI 10.12911/22998993/102964.
JABOYEDOFF M., OPPIKOFER T., ABELLÁN A., DERRON M.-H., LOYE A., METZGER R., PEDRAZZINI A. 2012. Use of LIDAR in landslide investigations: A review. Natural Hazards. No. 61 p. 5–28. DOI 10.1007/s11069-010-9634-2.
MARESCOT L., MONNET R., CHAPELLIER D. 2008. Resistivity and induced polarization surveys for slope instability studies in the Swiss Alps. Engineering Geology. Vol. 98(1) p. 18–28. DOI 10.1016/j.enggeo.2008.01.010.
MENSHOV O., SHEVCHENKO O., ANDREEVA O. 2020. Integration of magnetic and hydrogeological studies for landslides and soil erosion assessment. Case study from area Lake Glinka (Kyiv, Ukraine). Geoinformatics: Theoretical and Applied Aspects 2020. Conference Proceedings. Vol. 2020. 11–14.05.2020. Kyiv p. 1–5. European Association of Geoscientists & Engineers. DOI 10.3997/2214-4609.2020geo122.
MYKOLAENKO O.A., ZHYRNOV P.V., TOMCHENKO O.V., PIDLISETSKA I.O. 2020. Exogenic processes’ remote monitoring of Kanivske Reservoir’s right bank. Geoinformatics: Theoretical and Applied Aspects 2020. Conference Proceedings. Vol. 2020. 11–14.05.2020. Kyiv p. 1–5. European Association of Geoscientists & Engineers. DOI 10.3997/2214-4609.2020geo099.
PATELLA D. 1997. Introduction to ground surface self-potential tomography. Geophysical Prospecting. Vol. 45. Iss. 4 p. 653– 681. DOI 10.1046/j.1365-2478.1997.430277.x.
PERRONE A., LAPENNA V., PISCITELLI S. 2014. Electrical resistivity tomography technique for landslide investigation: A review. Earth-Science Reviews. Vol. 135 p. 65–82. DOI 10.1016/j.earscirev.2014.04.002.
REYNOLDS J. M. 2011. An introduction to applied and environmental geophysics. Chichester. John Wiley and Sons Ltd. ISBN 978-0- 471-48535-3 (pbk) pp. 710.
SANTOSO B., HASANAH M.U., SETIANTO 2019. Landslide investigation using self potential method and electrical resistivity tomography (Pasanggrahan, South Sumedang, Indonesia). IOP Conference Series: Earth and Environmental Science. Vol. 311 p. 1–9. International Symposium on Geophysical Issues. 2–4.06.2018, Bandung, Indonesia. DOI 10.1088/1755-1315/311/1/012068.
TELFORD W.M., GELDART L.P., SHERIFF R.E. 1990. Applied geophysics. Cambridge. Cambridge University Press. ISBN 9780521339384 pp. 792. DOI 10.1017/CBO9781139167932.
TEZA G., MARCATO G., CASTELLI E., GALGARO A. 2012. IRTROCK: A Matlab toolbox for contactless recognition of surface and shallow weakness traces of a rock mass by infrared thermo-graphy. Computers & Geosciences. Vol. 45 p. 109–118. DOI 10.1016/j.cageo.2011.10.022.
VYZHVA S., ONYSHCHUK V., ONYSHCHUK I., REVA M., SHABATURA O. 2019. Application of geophysical methods in the study of landslides. 18th International Conference on Geoinformatics – Theoretical and Applied Aspects. Kyiv, May 2019. European Association of Geoscientists & Engineers Source p. 1–5. DOI 10.3997/2214-4609.201902066.
WU J.H., LIN H.M., LEE D.H., FANG S.C. 2015. Integrity assessment of rock mass behind the shotcreted slope using thermography. Engineering Geology. Vol. 80. No. 1–2 p. 164–173. DOI 10.1016/j.enggeo.2005.04.005.
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Authors and Affiliations

Olena Ivanik
1
ORCID: ORCID
Joana Fonseca
2
ORCID: ORCID
Oleksandr Shabatura
1
ORCID: ORCID
Ruslan Khomenko
1
ORCID: ORCID
Kateryna Hadiatska
1
ORCID: ORCID
Dmytro Kravchenko
1
ORCID: ORCID

  1. Taras Shevchenko National University of Kyiv, Institute of Geology, 60, Volodymyrska str., Kyiv, 03001, Ukraine
  2. City, University of London, School of Mathematics, Computer Science and Engineering, Department of Civil Engineering, London, United Kingdom
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Abstract

The liver is a vital organ of the human body and hepatic cancer is one of the major causes of cancer deaths. Early and rapid diagnosis can reduce the mortality rate. It can be achieved through computerized cancer diagnosis and surgery planning systems. Segmentation plays a major role in these systems. This work evaluated the efficacy of the SegNet model in liver and particle swarm optimization-based clustering technique in liver lesion segmentation. Over 2400 CT images were used for training the deep learning network and ten CT datasets for validating the algorithm. The segmentation results were satisfactory. The values for Dice Coefficient and volumetric overlap error achieved were 0.940 ± 0.022 and 0.112 ± 0.038, respectively for liver and the results for lesion delineation were 0.4629 ± 0.287 and 0.6986 ± 0.203, respectively. The proposed method is effective for liver segmentation. However, lesion segmentation needs to be further improved for better accuracy.
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Authors and Affiliations

P Vaidehi Nayantara
1
Surekha Kamath
1
Manjunath KN
2
Rajagopal Kadavigere
2

  1. Department of Instrumentation and Control Engineering, Manipal Institute of Technology, Manipal Academy of Higher Education, Manipal, Karnataka, 576104, India
  2. Department of Computer Science and Engineering, Manipal Institute of Technology, Manipal Academy of Higher Education, Manipal, Karnataka, 576104, India
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Abstract

The 2019 Coronavirus (COVID-19) virus has caused damage on people's respiratory systems over the world. Computed Tomography (CT) is a faster complement for RT-PCR during peak virus spread times. Nowadays, Deep Learning (DL) with CT provides more robust and reliable methods for classifying patterns in medical pictures. In this paper, we proposed a simple low training proposed customized Convolutional Neural Networks (CNN) customized model based on CNN architecture that layers which are optionals may be included such as the layer of batch normalization to reduce time taken for training and a layer with a dropout to deal with overfitting. We employed a huge dataset of chest CT slices images from diverse sources COVIDx-CT, which consists of a 16,146-image dataset with 810 patients of various nationalities. The proposed customized model's classification results compared to the VGG-16, Alex Net, and ResNet50 Deep Learning models. The proposed CNN model shows robustness by achieving an overall accuracy of 93% compared to 88%, 89%, and 95% for the VGG-16, Alex Net, and ResNet50 DL models for the classification of 3 classes. When this relates to binary classification, the classification accuracy of the proposed model and the VGG-16 models were identical (almost 100% accurate), with 0.17% of misclassification in the class of Non-Covid-19, the Alex Net model achieved almost 100% classification accuracy with 0.33% misclassification in the class of Non-Covid-19. Finally, ResNet50 achieved 95% classification accuracy with 5% misclassification in the Non-Covid-19 class.
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Authors and Affiliations

Ahmed H. Eldeeb
1
Mohammed Nagah Amr
1
Amin S. Ibrahim
2
Hesham Kamel
1
Sara Fouad
3

  1. Electronics and Communications Department, School of Engineering, Canadian Higher Engineering Institute, Giza, Egypt
  2. Electronics and Communications Engineering Department, Thebes Higher Institute for Engineering, Cairo, Egypt
  3. Electronics and Communications Engineering Department, The Higher Institute of Engineering, Modern Academy, Cairo, Egypt

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