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Abstract

The Internet of Vehicles (IoVs) has become a vital research area in order to enhance passenger and road safety, increasing traffic efficiency and enhanced reliable connectivity. In this regard, for monitoring and controlling the communication between IoVs, routing protocols are deployed. Frequent changes that occur in the topology often leads to major challenges in IoVs, such as dynamic topology changes, shortest routing paths and also scalability. One of the best solutions for such challenges is “clustering”. This study focuses on IoVs’ stability and to create an efficient routing protocol in dynamic environment. In this context, we proposed a novel algorithm called Cluster-based enhanced AODV for IoVs (AODV-CD) to achieve stable and efficient clustering for simplifying routing and ensuring quality of service (QoS). Our proposed protocol enhances the overall network throughput and delivery ratio, with less routing load and less delay compared to AODV. Thus, extensive simulations are carried out in SUMO and NS2 for evaluating the efficiency of the AODV-CD that is superior to the classic AODV and other recent modified AODV algorithms.
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Authors and Affiliations

Sahar Ebadinezhad
1

  1. Department of Computer Information System, Near East University. Nicosia TRNC, Mersin 10, Turkey
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Abstract

Porosity is one of the major problems in casting operations and there are several discussions in the literature about the porosity formation in aluminum castings. Bifilms are the defects that are introduced into the melt by turbulence. They can be detected with reduced pressure test and presented numerically by measuring bifilm index. The measure of bifilm index is the sum of total oxide length given in millimeters from the cross-section of reduced pressure test sample solidified under 0.01 MPa. In this work, low pressure die casting (LPDC) unit was built in an attempt to enhance the producibility rate. The unit consists of a pump housing that was placed inside the melt in the melting furnace where the pressure was applied instead of the whole melt surface. It was observed that the melt quality of A356 alloy was deteriorated over time which had led to higher porosity. This was attributed to the increased oxide thickness of the bifilm by the consumption of air in between the folded oxides. A relationship was found between bifilm index and pore formation.
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Bibliography

[1] Campbell, J. (2011). Complete Casting Handbook: Metal Casting Processes. Techniques and Design. Elsevier Science.
[2] Bonollo, F., Urban, J., Bonatto, B. & Botter, M. (2005). Gravity and low pressure die casting of aluminium alloys: a technical and economical benchmark. La Metallurgia Italiana. 6, 23-32.
[3] Dispinar, D. & J. Campbell, (2004). Critical assessment of reduced pressure test. Part 2: Quantification. International Journal of Cast Metals Research. 17(5), 287-294.
[4] Raiszadeh, R., & Griffiths, W.D. (2006). A method to study the history of a double oxide film defect in liquid aluminum alloys. Metallurgical and Materials Transactions B. 37(6), 865-871.
[5] Raiszadeh, R., & Griffiths, W.D. (2008). A semi-empirical mathematical model to estimate the duration of the atmosphere within a double oxide film defect in pure aluminum alloy. Metallurgical and Materials Transactions B. 39(2), 298-303.
[6] Raiszadeh, R., & Griffiths, W.D. (2011). The effect of holding liquid aluminum alloys on oxide film content. Metallurgical and Materials Transactions B. 42(1), 133-143.
[7] Aryafar, M., Raiszadeh, R., & Shalbafzadeh, A. (2010). Healing of double oxide film defects in A356 aluminium melt. Journal of materials science. 45(11), 3041-3051.
[8] Farhoodi, B., Raiszadeh, R., & Ghanaatian, M. H. (2014). Role of double oxide film defects in the formation of gas porosity in commercial purity and Sr-containing Al alloys. Journal of Materials Science & Technology. 30(2), 154-162.
[9] Amirinejhad, S., Raiszadeh, R., & Doostmohammadi, H. (2013). Study of double oxide film defect behaviour in liquid Al–Mg alloys. International Journal of Cast Metals Research. 26(6), 330-338.
[10] Bakhtiarani, F.N., & Raiszadeh, R. (2011). Healing of double-oxide film defects in commercial purity aluminum melt. Metallurgical and Materials Transactions B. 42(2), 331-340.
[11] Bagherpour-Torghabeh, H., Raiszadeh, R., & Doostmohammadi, H. (2017). Role of Mechanical Stirring of Al-Mg Melt in the Healing of Bifilm Defect. Metallurgical and Materials Transactions B. 48(6), 3174-3184.
[12] Nateghian, M., Raiszadeh, R., & Doostmohammadi, H. (2012). Behavior of Double-Oxide Film Defects in Al-0.05 wt pct Sr Alloy. Metallurgical and Materials Transactions B. 43(6), 1540-1549.
[13] Stefanescu, D.M. (2005). Computer simulation of shrinkage related defects in metal castings - a review. International Journal of Cast Metals Research. 18, 129-143.
[14] Zhu, J.D., Cockcroft, S.L., Maijer, D.M. & Ding, R. (2005). Simulation of microporosity in A356 aluminium alloy castings. International Journal of Cast Metals Research. 18, 229-235.
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[20] Campbell, J. (1967), Shrinkage pressure in castings (The solidification of a Metal Sphere). Transactions of the Metallurgical Society of AIME, 239 (February), 138-142.
[21] Dispinar, D. & Campbell, J. (2004). Critical assessment of reduced pressure test. Part 1: Porosity phenomena. International Journal of Cast Metals Research. 17(5), 280-286.
[22] Dispinar, D., Akhtar, S., Nordmark, A., Di Sabatino, M., & Arnberg, L. (2010). Degassing, hydrogen and porosity phenomena in A356. Materials Science and Engineering: A. 527(16-17), 3719-3725.
[23] Puga, H., Barbosa, J., Azevedo, T., Ribeiro, S. & Alves, J.L. (2016). Low pressure sand casting of ultrasonically degassed AlSi7Mg0. 3 alloy: Modelling and experimental validation of mould filling. Materials & Design. 94, 384-391.
[24] El-Sayed, M.A. & Essa, K. (2018). Effect of mould type and solidification time on bifilm defects and mechanical properties of Al–7si–0.3 mg alloy castings. Computational and Experimental Studies, 23.
[25] Gyarmati, G., Fegyverneki, G., Mende, T. & Tokár, M. (2019). Characterization of the double oxide film content of liquid aluminum alloys by computed tomography. Materials Characterization. 157, 109925. [26] Gyarmati, G., Fegyverneki, G., Tokár, M., & Mende, T. (2020). The Effects of Rotary Degassing Treatments on the Melt Quality of an Al–Si Casting Alloy. International Journal of Metalcasting. 1-11.
[27] Tiryakioğlu, M. (2020). The Effect of Hydrogen on Pore Formation in Aluminum Alloy Castings: Myth Versus Reality. Metals. 10(3), 368.
[28] Tiryakioğlu, M. (2019). Solubility of hydrogen in liquid aluminium: reanalysis of available data. International Journal of Cast Metals Research. 32(5-6), 315-318.
[29] Tiryakioğlu, M. (2020). A simple model to estimate hydrogen solubility in liquid aluminium alloys. International Journal of Cast Metals Research. 1-3.
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Authors and Affiliations

O. Gursoy
1
A. Nordmak
2
F. Syvertsen
2
M. Colak
3
K. Tur
4
D. Dispinar
5
ORCID: ORCID

  1. University of Padova, Italy
  2. SINTEF, Norway
  3. University of Bayburt, Turkey
  4. Atilim University, Turkey
  5. Istanbul Technical University, Turkey
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Abstract

This paper presents an overview of a research on six practical cases that were solved in a precise casting company where parts are cast by the mean of the low-wax casting method (investment casting) in order to decrease poor quality production. The steel cast parts production technology by the lost-wax method requires the detailed work procedures observation. On the base of statistical processing data of given types of casting products, it was possible to assess the significance of each particular checking events by using the statistical hypothesis testing. The attention was focused on wax and ceramic departments. The data in technological flow were compared before and after the implementation of the change and statistical confirmative influences were assessed. The target consisted in setting such control manners in order to get the right conditions for decreasing poor quality parts. It was evidenced that the cast part defect cause correct identification and interpretation is important.
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Bibliography

[1] Elbel, T., Havlíček, F., Jelínek, P., Levíček, P., Rous, J., Stránský, K. (1992). Defects of iron alloy castings (classification, causes and prevention). Brno: MATECS. (in Czech).
[2] Nenadál, J. (2004). Measurement in quality management systems. Praha: Management Press. (in Czech).
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[7] Jaromin, M., Dojka, R., Jezierski, J., Dojka, M. (2019). Influence of Type and Shape of the Chill on Solidification Process of Steel Casting. Archives of Foundry Engineering. 19(1), 35-40. ISSN (1897-3310).
[8] Richtarech, L., Bolibruchova, D.; Bruna, M.; Caiss, J. (2015). Influence of Nickel Addition on Properties of Secondary AlSi7Mg0.3 Alloy‎. Archives of Foundry Engineering. 15(2), 95-98. ISSN (1897-3310). DOI: 10.1515/afe-2015-0046.
[9] Merta, V., Lána, I. (2020). Manufacturing of Cast-metal Sponges from Copper Alloys. Materiali in Technologije. 54(1), 117-119. DOI: 10.17222/mit.2019.159.
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Authors and Affiliations

R. Lakomá
1
L. Čamek
2
P. Lichý
2
ORCID: ORCID
I. Kroupová
1
ORCID: ORCID
F. Radkovský
1
ORCID: ORCID
T. Obzina
1

  1. VSB - Technical university of Ostrava, Czech Republic
  2. Brno University of Technology, Czech Republic
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Abstract

The paper presents the results of research related to the possibility of inoculation of the AZ91 magnesium alloy casted into ceramic moulds by gadolinium. Effects of gadolinium content (0.1–0.6 wt%) on microstructure of the AZ91 alloy under as-cast state were investigated. The influence of the inoculator on the formation of the microstructure investigated by means of the thermal and derivative analysis by analysing the thermal effects arising during the alloy crystallization resulting from the phases formed. The degree of fragmentation of the microstructure of the tested alloys was assessed by means of the light microscopy studies and an image analysis with statistical analysis was performed. Conducted analyses have aimed at examining on the effect of inoculation of the gadolinium on the differences between the grain diameters and average size of each type of grain by way of measuring their perimeters of all phases, preliminary αMg and eutectics αMg+γ(Mg17Al12) in the prepared examined material.
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Bibliography

[1] Wang, Y.N. & Huang, J.C. (2007). The role of twinning and untwining in yielding behavior in hot-extruded Mg-Al-Zn. Alloy Acta Materialia. 55(3), 897-905. DOI: 10.1016/ j.actamat.2006.09.010.
[2] Yu, Zhang et. al (2017). Effects of samarium addition on as-cast microstructure, grain fragmentation and mechanical properties of Mg-6Zn-0.4Zr magnesium alloy. Journal of Rare Earths. 167(1), 31-33. DOI: 10.1016/S1002-0721(17)60939-6.
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[4] Mao, X., Yi, Y., Huang, S. & He, H. (2019). Bulging limit of AZ31B magnesium alloy tubes in hydroforming with internal and external pressure. The International Journal of Advanced Manufacturing Technology. 101, 2509-2517. DOI: https://doi.org/10.1007/s00170-018-3076-5.
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[6] Rapiejko, C., Pisarek, B. & Pacyniak, T. (2017). Effect of intensive cooling of alloy AZ91 with a chromium addition on the microstructure and mechanical properties of the casting. Archives of Metallurgy and Materials. 62(4), 2199-2204. DOI: 10.1515/amm-2017-0324.
[7] Zhao, H.L., Guan, S.K. & Zheng, F.Y. (2007). Effects of Sr and B addition on microstructure and mechanical properties of AZ91 magnesium alloy. Journal of Materials Research. 22, 2423-2428. DOI: 10.1557/jmr.2007.0331.
[8] Bonnah, R.C., Fu, Y. & Hao, H. (2019). Microstructure and mechanical properties ofAZ91 magnesium alloy with minor additions of Sm, Si and Ca elements. China Foundry. 16(5), 319-325. DOI: 10.1007/s41230-019-9067-9.
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[10] Boby, A., Ravikumar, K.K., Pillai, U.T.S. & Pai, B.C. (2013). Effect of antimony and yttrium addition on the high temperature properties of AZ91 magnesium alloy. Procedia Engineering 55. 355(5), 98-102. DOI: 10.1016/j.proeng. 2013.03.226.
[11] Huang, W., Yang, X., Mukai, T. & Sakai, T. (2019). Effect of yttrium addition on the hot deformation behaviors and microstructure development of magnesium alloy. Journal of Alloys and Compounds. 786, 118-125. DOI: 10.1016/ j.jallcom.2019.01.269.
[12] Pourbahari, B., Mirzadeh, H., Emamy, M. & Roumina, R. (2018). Enhanced ductility of afine-grained Mg-Gd-Al-Zn magnesium alloy by hot extrusion. Advanced Engineering Materials. 20, 1701171. DOI: 10.1002/adem.201701171.
[13] Tardif, S., Tremblay, R. & Dubé, D. (2010). Influence of cerium on the microstructure and mechanical properties of ZA104 and ZA104 + 0.3Ca magnesium alloys. Material Science and Engineering A. 527, 7519-7529. DOI: 10.1016/j.msea.2010.08.082.
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[19] Pietrowski, S. & Rapiejko, C. (2011). Temperature and microstructure characteristics of silumin casting AlSi9 made with investment casting method. Archives of Foundry Engineering. 11(3), 177-186.
[20] PN-EN 1753:2001. Magnesium and magnesium alloys. Magnesium alloy ingots and castings.
[21] Rapiejko, C., Pisarek, B, Czekaj, E. & Pacyniak, T. (2014). Analysis of AM60 and AZ91 Alloy Crystallisation in ceramic moulds by thermal derivative analisys (TDA). Archive of Metallurgy and Materials. 59(4) DOI: 10.2478/amm-2014-0246.
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Authors and Affiliations

C. Rapiejko
1
ORCID: ORCID
D. Mikusek
1
P. Just
1
T. Pacyniak
1
ORCID: ORCID

  1. Lodz University of Technology, Department of Materials Engineering and Production Systems, ul. Stefanowskiego 1, 90-924 Łódź, Poland
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Abstract

Aiming at the problems of delay and couple in the sintering temperature control system of lithium batteries, a fuzzy neural network controller that can solve complex nonlinear temperature control is designed in this paper. The influence of heating voltage, air inlet speed and air inlet volume on the control of temperature of lithium battery sintering is analyzed, and a fuzzy control system by using MATLAB toolbox is established. And on this basis, a fuzzy neural network controller is designed, and then a PID control system and a fuzzy neural network control system are established through SIMULINK. The simulation shows that the response time of the fuzzy neural network control system compared with the PID control system is shortened by 24s, the system stability adjustment time is shortened by 160s, and the maximum overshoot is reduced by 6.1%. The research results show that the fuzzy neural network control system can not only realize the adjustment of lithium battery sintering temperature control faster, but also has strong adaptability, fault tolerance and anti-interference ability.
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Bibliography

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Authors and Affiliations

Zou Chaoxin
1
Li Rong
1
Xie Zhiping
1
Su Ming
1
Zeng Jingshi
2
Ji Xu
1
Ye Xiaoli
1
Wang Ye
1

  1. Guizhou Normal University, China
  2. Guizhou Zhenhua New Material Co., Ltd., China
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Abstract

Obstructive Sleep Apnea is one common form of sleep apnea and is now tested by means of a process called Polysomnography which is time-consuming, expensive and also requires a human observer throughout the study of the subject which makes it inconvenient and new detection techniques are now being developed to overcome these difficulties. Heart rate variability has proven to be related to sleep apnea episodes and thus the features from the ECG signal can be used in the detection of sleep apnea. The proposed detection technique uses Support Vector Machines using Grid search algorithm and the classifier is trained using features based on heart rate variability derived from the ECG signal. The developed system is tested using the dataset and the results show that this classification system can recognize the disorder with an accuracy rate of 89%. Further, the use of the grid search algorithm has made this system a reliable and an accurate means for the classification of sleep apnea and can serve as a basis for the future development of its screening.
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Authors and Affiliations

K.K. Valavan
1
S. Manoj
1
S. Abishek
1
T.G. Gokull Vijay
1
A.P. Vojaswwin
1
J. Rolant Gini
1
K.I. Ramachandran
2

  1. Department of Electronics and Communication Engineering, Amrita School of Engineering, Coimbatore, Amrita Vishwa Vidyapeetham, India
  2. Centre for Computational Engineering & Networking (CEN), Amrita School of Engineering, Coimbatore, Amrita Vishwa Vidyapeetham, India
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Abstract

Titanium alloys belonging to the group of modern metallic materials used in many industries, including the aerospace industries. Induction crucible vacuum furnaces and induction furnaces with cold crucible are most commonly used for their smelting. When operating these devices, one can deal with an adverse phenomenon of decrease in the content of alloy elements that are characterized by higher equilibrium vapour pressure than the matrix metal or titanium, in the metal bath. In the paper, results of the study on aluminium evaporation from the Ti-Al-Nb, Ti-Al-V and Ti-Al alloys (max 6.2 % wt.) during smelting in a vacuum induction melting (VIM) furnace are presented. The experiments were performed at 10 to 1000 Pa for 1973 K and 2023 K. A significant degree of aluminium loss has been demonstrated during the analysed process. The values of relative aluminium loss for all the alloys ranged from 4 % to 25 %. Lowering the pressure in the melting system from 1000 Pa to 10 Pa resulted in increased values of aluminium evaporation flux from 4.82⋅10-5 to 0.000327 g⋅cm-2⋅s-1 for 1973 K and from 9.28⋅10-5 to 0.000344 g⋅cm-2⋅s-1 for 2023 K. The analysis of the results obtained took into account the value of the actual surface of the liquid metal. In the case of melting metals in an induction furnace, this surface depends on the value of power emitted in the charge. At greater power, we observe a significant increase in the bath surface due to the formation of a meniscus.
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Bibliography

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Authors and Affiliations

Albert Smalcerz
ORCID: ORCID
Leszek Blacha
ORCID: ORCID
J. Łabaj
1
ORCID: ORCID

  1. Silesian University of Technology, Faculty of Materials Engineering and Metallurgy, ul. Krasińskiego 8, 40-019 Katowice, Poland

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