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Temperature Effects on the Microstructures of Mg-gd-Y Alloy Processed by Multi-direction Impact Forging

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Acta Metallurgica sinica(English Letters) 2020年第2期33卷 243-251页

作者： s.s.A.shah D.Wu R.s.Chen g.s.song school of Material science and Engineering Anhui University of Technology The group of Magnesium Alloys and Their Applications Institute of Metal ResearchChinese Academy of Sciences

A high strain rate multi-directional impact forging(MDIF) was applied to a solutionized Mg-gd-Y-Zr alloy in the temperature range of 350-500℃.Results demonstrate that the dominant deformation mode is twinning at a temperature below 400℃,whereas at a medium temperature of 450℃ considerable continuous dynamic recrystallization was promoted by{10-12} extension *** a higher temperature of 500℃,twinning activation was *** DRX grains were observed but their sizes were much bigger than those resulting from the MDIFed 50 passes at 450℃,which are ascribed to the larger grain boundary mobility and atomic diffusion at 500℃.Moreover,a non-basal weak texture was.g.ined afterward MDIF at each temperature,which is credited to the MDIF process and the minor strain applied in each pass.

关键词： Magnesium alloys Twinning Dynamic recrystallization Forging Texture

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Finite element models to represent seismic activity of the Indian plate

作者： s.g.·科钦(s.g. Kochan)

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geoscience Frontiers 2017年第1期8卷 81-91页

作者： s.Jayalakshmi s.T.g.Raghukanth Department of Civil Engineering Indian Institute of TechnologyMadras 600036India

Quantification of seismic activity is one of the most challenging problems faced by earthquake engineers in probabilistic seismic hazard analysis. Currently, this problem has been attempted using empirical approaches which are based on the regional earthquake recurrence relations from the available earth- quake catalogue. However, at a specified site of engineering interest, these empirical models are asso- ciated with large number of uncertainties due to lack of sufficient data. Due to these uncertainties, engineers need to develop mechanistic models to quantify seismic activity. A wide range of techniques for modeling continental plates provides useful ins.g.ts on the mechanics of plates and their seismic activity. Among the different continental plates, the Indian plate experiences diffused seismicity. In India, although Himalaya is regarded as a plate boundary and active region, the seismicity database indicates that there are other regions in the Indian shield reporting sporadic seismic activity. It is expected that mechanistic models of Indian plate, based on finite element method, simulate stress fields that quantify the seismic potential of active regions in India, This article explores the development of a finite element model for Indian plate by observing the simulated stress field for various boundary conditions, geological and theological conditions. The study observes that the magnitude and direction of stresses in the plate is sensitive to these conditions, The numerical analysis of the models shows that the simulated stress field represents the active seismic zones in India.

关键词： Indian platePlate driving forcesFinite element modeseismicityCratons

Analytical solutions to nonlinear conservative oscillator with fifth-order nonlinearity

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Earthquake Engineering and Engineering Vibration 2010年第3期9卷 367-374页

作者： M.g.sfahani s.s.g.nji A.Barari H.Mirgolbabaei g.Domairry Departments of Civil and Mechanical Engineering Babol University of Technology Department of Transportation Engineering Islamic Azad UniversityScience and Research Branch Department of Civil Engineering Aalborg University Department of Mechanical Engineering Islamic Azad University

This paper describes analytical and numerical methods to analyze the steady state periodic response of an oscillator with symmetric elastic and inertia nonlinearity. A new implementation of the homotopy perturbation method （HPM） and an ancient Chinese method called the max-rain approach are presented to obtain an approximate solution. The major concern is to assess the accuracy of these approximate methods in predicting the system response within a certain range of system parameters by examining their ability to establish an actual （numerical） solution. Therefore, the analytical results are compared with the numerical results to illustrate the effectiveness and convenience of the proposed methods.

关键词： non-linear oscillation homotopy perturbation method (HPM) max-min approach (MMA) Rung-Kutta method (R-KM) large amplitude free vibrations

The adsorption and corrosion inhibition of 8-hydroxy-7-quinolinecarboxaldehyde derivatives on C-steel surface in hydrochloric acid

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Chinese Journal of Chemical Engineering 2017年第9期25卷 1256-1265页

作者： A.M.Eldesoky s.g.Nozha Engineering Chemistry Department High Institute of Engineering & Technology Al-Qunfudah Center for scientific Research (QCsR) Al-Qunfudah University College Umm Al-Qura University Ministry of Health Domyat Laboratory

The protection influence of 8-hydroxy-7-quinolinecarboxaldehyde derivatives against C-steel corrosion was studied in 2 mol·L^(-1)HCl solutions at 30 °C. Measurements were conducted under various experimental conditions using weight loss, potentiodynamic polarization, electrochemical impedance spectroscopy(EIs) and electrochemical frequency modulation(EFM) techniques. These studies have shown that 8-hydroxy-7-quinolinecarboxaldehyde derivatives are very good "green", mixed-type inhibitors. Corrosion rates obtained from both EFM and EIs methods are comparable with those recorded using Tafel extrapolation method, confirming validation of corrosion rates measured by the latter. The inhibitive action of these 8-hydroxy-7-quinolinecarboxaldehyde derivatives was discussed in terms of blocking the electrode surface by adsorption of the molecules through the active centers contained in their structures following Langmuir adsorption isotherm. Quantum chemical method was also employed to explore the relationship between the inhibitor molecular properties and its protection efficiency.

关键词： 8-Hydroxy-7-quinolinecarboxaldehyde derivatives C-steel HCl EFM

synthesis of β-cyclodextrin functionalized gold nanoparticles for the selective detection of Pb2＋ ions from aqueous solution

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Frontiers of Materials science 2012年第2期6卷 168-175页

作者： B.AsWATHY g.s.AVADHANI s.sUJI g.sONY Department of Chemistry University of KeralaKariavattom CampusThiruvananthapuramKerala 691021India Department of Materials Engineering Indian Institute of ScienceBangaloreIndia

In the present study we carried out the synthesis of β-cyclodextrin （β-CD） functionalized gold nanoparticles （AuNPs） using a microwave assisted heating method in alkaline media. stable dispersion of β-CD stabilized AuNPs was obtained at an optimized pH of 10,5. At this pH value the deprotonated secondary hydroxyl group of β-CD shows the highest chelating affinity toward Pb2＋ ions thereby inducing AuNP aggregation. The Pb2＋ induced aggregation in β-CD-AuNP solution is monitored by both colorimetric response and UV-Vis spectroscopy. TEM, DLs and FTIR analyses were carried out to confirm the Pb2＋ ion induced aggregation behaviour of β-CD-AuNPs under alkaline conditions. Furthermore at the experimental pH the response of the β-CD-AuNP system towards Pb2＋ ions is selective when compared with other interfering metal cations.

关键词： gold nanoparticle (AuNP) β-cyclodextrin (β-CD) colorimetric detection,metal ion

MHD graphene-polydimethylsiloxane Maxwell nanofluid flow in a squeezing channel with thermal radiation effects

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Applied Mathematics and Mechanics(English Edition) 2019年第9期40卷 1269-1284页

作者： g.C.sHIT s.MUKHERJEE Department of Mathematics Jadavpur University

The magnetohydrodynamic (MHD) graphene-polydimethylsiloxane (PDMs) nanofluid flow between two squeezing parallel plates in the presence of thermal radiation effects is investigated. The energy efficiency of the system via the Bejan number is studied extensively. The governing partial differential equations are converted by using the similarity transformations into a set of coupled ordinary differential equations. The set of these converted equations is solved by using the differential transform method (DTM). The entropy generation in terms of the Bejan number, the coefficient of skin-friction, and the heat transfer rate is furthermore investigated under the effects of various physical parameters of interest. The present study shows that the Bejan number, the velocity and thermal profiles, and the rate of heat transfer decrease with a rise in the Deborah number De while the skin-friction coefficient increases. It is also observed that the entropy generation due to frictional forces is higher than that due to thermal effects. Thus, the study bears the potential application in powder technology as well as in biomedical engineering.

关键词： graphene-polydimethylsiloxane (PDMs) Maxwell fluid differential transform method (DTM) thermal radiation Bejan number

Rating damage potential of ground motion records

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Earthquake Engineering and Engineering Vibration 2019年第2期18卷 233-254页

作者： Bhargavi Podili Raghukanth s.T.g Department of Civil Engineering Indian Institute of Technology Madras

In this study, a total of 115,246 ground motions recorded during earthquakes of Moment magnitudes ranging from M_w 5.0 to M_w 9.0 are analyzed statistically. A total of 21 ground motion parameters characterising the recorded acceleration time histories are used in the analysis. Classification of these parameters through statistical correlation is reported and a parameter called "distance from zero-amplitude axis," or d_(Z-A), is formulated in the principal component space. The ability for d_(Z-A) to rate the damage potentials of strong motion records is evaluated through correlation of d_(Z-A) with Japan Meteorological Agency(JMA) instrumental seismic intensities. This parameter can be used to rate damage potential of any strong motion record irrespective of the magnitude and location of the earthquake. It can also be used in selecting ground motion records of appropriate damage potential in seismic des.g. and probabilistic analysis.

关键词： damage potential principal component analysis ground motion parameters zero-amplitude axis

Mobile Fog Computing by Using sDN/NFV on 5g Edge Nodes

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Computer systems science & Engineering 2022年第5期41卷 751-765页

作者： g.R.sreekanth s.Ahmed Najat Ahmed Marko sarac Ivana strumberger Nebojsa Bacanin Miodrag Zivkovic Department of Computer science and Engineering Kongu Engineering CollegeErode638060India Department of Computer Engineering Lebanese French UniversityErbil44001Iraq singidunum University Belgrade11000Serbia

Abstract:Fog computing provides quality of service for cloud *** the data computation intensifies,edge computing becomes ***,mobile fog computing is used for reducing traffic and the time for data computation in the *** previous studies,software-defined networking(sDN)and network functions virtualization(NFV)were used separately in edge *** industrial and academic research is tackling to integrate sDN and NFV in different environments to address the challenges in performance,reliability,and ***/NFV is still in *** traditional Internet of things(IoT)data analysis system is only based on a linear and time-variant system that needs an IoT data system with a high-precision *** paper proposes a combined architecture of sDN and NFV on an edge node server for IoT devices to reduce the computational complexity in cloud-based fog *** provides a generalization structure of the forwarding plane,which is separated from the control ***,NFV concentrates on virtualization by combining the forwarding model with virtual network functions(VNFs)as a single or chain of VNFs,which leads to interoperability and *** orchestrator layer in the proposed software-defined NFV is responsible for handling real-time tasks by using an edge node server through the sDN controller via four actions:task creation,modification,operation,and *** proposed architecture is simulated on the EstiNet simulator,and total time delay,reliability,and satisfaction are used as evaluation *** simulation results are compared with the results of existing architectures,such as software-defined unified virtual monitoring function and AsTP,to analyze the performance of the proposed *** analysis results indicate that our proposed architecture achieves better performance in terms of total time delay(1800 s for 200 IoT devices),reliability(90%),and satisfaction(90%).

关键词： Mobile fog computing edge computing edge node IoT softwaredefined networking network functions virtualization orchestrator