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A QUICK AND GREEN IONIC LIQUID-MEDIATED APPROACH FOR THE SYNTHESIS OF HIGH-PERFORMANCE, ORGANOSOLUBLE AND THERMALLY STABLE POLYIMIDES

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Chinese Journal of Polymer Science 2013年第4期31卷 679-690页

作者： Mehdi Taghavi Mousa Ghaemy Marjan Hassanzadeh seyed mojtaba Amini Nasab Polymer Chemistry Research Laboratory Department of ChemistryUniversity of MazandaranBabolsar 47416-95447Iran

Three diamine monomers with different derivatives of imidazole heterocyclic ring and meta-linked aryl ethers were synthesized and used in polycodensation reaction with various commercial dianhydrides for preparation of a series of novel poly（ether-imide）（PEI）s. The polycodensation reactions were carried out by using conventional method and in a green medium of ionic liquid （IL） without using NMP-pyridine-acetic anhydride. The PEIs were obtained in good yields （80%-96%） with moderate viscosity （0.48-0.66 dL/g） in a shorter reaction time （10 h） in IL as compared with the conventional method （36 h）. All of the polymers were amorphous in nature, showed excellent solubility in amide-type polar aprotic solvents with ability to form tough and flexible films, and excellent thermal stability with Tgs in the range of 212-340℃ and 10% weight loss temperature （T10） up to 570℃ in N2 and 528 ℃ in air.

关键词： Ionic liquids Poly(ether-imide) Polycodensation Green media Thermal properties.

Geometrically Nonlinear Analysis of Structures Using Various Higher Order Solution Methods: A Comparative Analysis for Large Deformation

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Computer Modeling in Engineering & Sciences 2019年第12期121卷 877-907页

作者： Ali Maghami Farzad Shahabian seyed Mahmoud hosseini Civil Engineering Department Faculty of EngineeringFerdowsi University of MashhadMashhadIran Industrial Engineering Department Faculty of EngineeringFerdowsi University of MashhadMashhadIran

The suitability of six higher order root solvers is examined for solving the nonlinear equilibrium equations in large deformation analysis of *** applied methods have a better convergence rate than the quadratic Newton-Raphson *** six methods do not require higher order derivatives to achieve a higher convergence *** algorithms are developed to use the higher order methods in place of the Newton-Raphson method to solve the nonlinear equilibrium equations in geometrically nonlinear analysis of *** higher order methods are applied to both continuum and discrete problems(spherical shell and dome truss).The computational cost and the sensitivity of the higher order solution methods and the Newton-Raphson method with respect to the load increment size are comparatively *** numerical results reveal that the higher order methods require a lower number of iterations that the Newton-Raphson method to *** is also shown that these methods are less sensitive to the variation of the load increment *** it is indicated in numerical results,the average residual reduces in a lower number of iterations by the application of the higher order methods in the nonlinear analysis of structures.

关键词： Geometrically nonlinear analysis higher order methods predictor-corrector algorithms convergence rate sensitivity to the increment size

Seismic assessment of nature-inspired hexagrid lateral load-resisting system

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Earthquake Engineering and Engineering Vibration 2021年第3期20卷 661-672页

作者： Yasaman Memarzadeh Kiani seyed Hossein hosseini Lavassani Afshin Meshkat-Dini Department of Civil Engineering Faculty of EngineeringKharazmi UniversityTehranIran

This paper provides a general perspective of the seismic performance of a nature-inspired,honey-comb grid structural system,known as a hexagrid,under near-field ground *** performance of this skeleton is then compared to that of a bundled-tube,as a conventional and efficient load-resisting system in order to provide a better perception of the seismic behavior of a hexagrid *** 20-story buildings with bundled-tube and hexagrid skeleton were *** behavior of the structures was investigated through 3-D finite element computer models and nonlinear time history analyses by subjecting the models to seven three-component records of scaled near-field ground *** of peak inter story drift and corner beam-column joint rotations were calculated and *** indicated that by replacing the exterior columns of the bundled-tube system with inclined beam-column elements of nature-inspired hexagons,lateral stiffness of the building increased and it would tolerate less deformations before global dynamic instability is *** presence of inclined columns in the hexagrid skeleton helped to concentrate local nonlinearities in ring beams rather than exterior columns.

关键词： high-rise steel structure hexagrid structure performance assessment nonlinear seismic analysis

Numerical study of aerosol particle deposition in simple and converging-diverging micro-channels with a slip boundary condition at the wall

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Particuology 2014年第2期12卷 100-105页

作者： seyed Mohammad Javad hosseini Ataallah Soltani Goharrizi Bahador Abolpour Department of Chemical Engineering Faculty of EngineeringShahid Bahonar University of Kerman

The design of micro-devices involving aerosol transport requires the study of the deposition of aerosols in micro-channels. In this study, the slip and no-slip boundary conditions for the gas flow regime were applied to the Navier-Stokes equations to obtain the particle deposition in simple and converging-diverging micro-channels. The equation of particle motion included inertial, viscous, Brownian, and gravity terms. It was found that the ratio of gravity to inertial effects controls the deposition of particles with diameters of 0.1-1 μm, and the ratio of diffusion to inertial effects controls the deposition of particles with diameters of 0.01-0.001 i^m. Comparison between the no-slip and slip flow regimes showed that the deposition of 0.1- to 1-μm-diameter particles was less and the deposition of 0.01- to 0.001-1μm-diameter particles was greater for the slip flow regime. There was no significant difference between slip and no-slip flow regimes for the deposition of 0.01- to 0.1-μm-diameter particles. Finally, it was shown that the stagnated gas in the corners of the converging-diverging micro-channel produced similar gas velocity profiles under the slip and no-slip flow regimes.

关键词： Aerosol depositionMicro-channelConverging-diverging micro-channelSlip boundary condition

Numerical study of the melting of nano-enhanced phase change material in a square cavity

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2013年第5期14卷 307-316页

作者： seyed Sahand SEBTI Mohammad MASTIANI Hooshyar MIRZAEI Abdolrahman DADVAND Sina KASHANI seyed Amir hosseini Department of Mechanical Engineering Urmia University of TechnologyUrmiaIran Department of Research and Development Delvar Afzar Industrial Gases Co.Ltd.TehranIran Department of Mechanical Engineering Islamic Azad UniversityGorgan BranchKordkoy CenterGolestanIran

A comprehensive numerical study was conducted to investigate heat transfer enhancement during the melting process in a 2D square cavity through dispersion of nanoparticles.A paraffin-based nanofluid containing various volume fractions of Cu was *** governing equations were solved on a non-uniform mesh using a pressure-based finite volume method with an enthalpy porosity technique to trace the solid-liquid *** effects of nanoparticle dispersion in a pure fluid and of some significant parameters,namely nanoparticle volume fraction,cavity size and hot wall temperature,on the fluid flow,heat transfer features and melting time were *** results are presented in terms of temperature and velocity profiles,streamlines,isotherms,moving interface position,solid fraction and dimensionless heat *** suspended nanoparticles caused an increase in thermal conductivity of nano-enhanced phase change material(NEPCM)compared to conventional PCM,resulting in heat transfer enhancement and a higher melting *** addition,the nanofluid heat transfer rate increased and the melting time decreased as the volume fraction of nanoparticles *** higher temperature difference between the melting temperature and the hot wall temperature expedited the melting process of NEPCM.

关键词： Nanofluid Phase change material(PCM) Melting Thermal energy storage Square cavity

An Efficient Lightweight Authentication and Key Agreement Protocol for Patient Privacy

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Computers, Materials & Continua 2021年第12期69卷 3495-3512页

作者： seyed Amin hosseini Seno Mahdi Nikooghadam Rahmat Budiarto Department of Computer Engineering Ferdowsi University of MashhadMashhad***Iran Department of Informatics Faculty of Science and TechnologyUniversitas Alazhar IndonesiaJakarta12110Indonesia

Tele-medical information system provides an efficient and convenient way to connect patients at home with medical personnel in clinical *** this system,service providers consider user authentication as a critical *** address this crucial requirement,various types of validation and key agreement protocols have been *** main problem with the two-way authentication of patients and medical servers is not built with thorough and comprehensive analysis that makes the protocol design yet has *** paper analyzes carefully all aspects of security requirements including the perfect forward secrecy in order to develop an efficient and robust lightweight authentication and key agreement *** secureness of the proposed protocol undergoes an informal analysis,whose findings show that different security features are provided,including perfect forward secrecy and a resistance to DoS ***,it is simulated and formally analyzed using Scyther *** results indicate the protocol’s robustness,both in perfect forward security and against various *** addition,the proposed protocol was compared with those of other related protocols in term of time complexity and communication *** time complexity of the proposed protocol only involves time of performing a hash function Th,i.e.,:O(12Th).Average time required for executing the authentication is 0.006 seconds;with number of bit exchange is 704,both values are the lowest among the other *** results of the comparison point to a superior performance by the proposed protocol.

关键词： Authentication key agreement protocol tele-medical Scyther perfect forward secrecy

Suspended sediment load prediction using non-dominated sorting genetic algorithm Ⅱ

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International Soil and Water Conservation Research 2019年第2期7卷 119-129页

作者： Mahmoudreza Tabatabaei Amin Salehpour Jam seyed Ahmad hosseini Soil Conservation and Watershed Management Research Institute Agricultural ResearchEducation and Extension Organization(AREEO)TehranIran

Awareness of suspended sediment load (SSL) and its continuous monitoring plays an important role in soil erosion studies and watershed *** the common use of the conventional model of the sediment rating curve (SRC) and the methods proposed to correct it,the results of this model are still not sufficiently *** this study,in order to increase the efficiency of SRC model,a multi-objective optimization approach is proposed using the Non-dominated Sorting Genetic Algorithm Ⅱ (NSGA-Ⅱ) *** instantaneous flow discharge and SSL data from the Ramian hydrometric station on the Ghorichay River,Iran are used as a case *** the first part of the study,using self-organizing map (SOM),an unsupervised artificial neural network,the data were clustered and classified as two homogeneous groups as 70% and 30% for use in calibration and evaluation of SRC models,*** the second part of the study,two different groups of SRC model comprised of conventional SRC models and optimized models (single and multi-objective optimization algorithms) were extracted from calibration data set and their performance was *** comparative analysis of the results revealed that the optimal SRC model achieved through NSGA-Ⅱ algorithm was superior to the SRC models in the daily SSL estimation for the data used in this *** that the use of the SRC model is common,the proposed model in this study can increase the efficiency of this regression model.

关键词： Clustering Neural network Non-dominated sorting genetic algorithm Ⅱ (NSGA-Ⅱ) Sediment rating curve Self-organizing map

Effects of Pits and Mounds Following Windthrow Events on Soil Features and Greenhouse Gas Fluxes in a Temperate Forest

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Pedosphere 2015年第6期25卷 853-867页

作者： Yahya KOOCH Sakineh Mollaei DARABI seyed Mohsen hosseini Department of Forestry Faculty of Natural Resources & Marine SciencesTarbiat Modares University

Pit and mound micro-relief(resultant microsites from trees uprooted by windthrow) could have regimes of microclimate and soil features that differ from areas of undisturbed soil. In an attempt to provide a comprehensive evaluation of the significance of pits and mounds on soil features and also the dynamics of greenhouse gas(GHG) fluxes at local scale, this study was carried out in a reserved area of Darabkola forest in Mazandaran Province, northern Iran. The age of a pit and mound was considered equal to the degree of decay of the blown down tree. Three microsites were distinguished, consisting of pit bottom(PB), mound top(MT) and undisturbed area(UA). Soil samples were taken at 0–15 and 15–30 cm depths from all microsites and analysed for soil physical, chemical and biological features. Our findings suggested that in context of forest ecology, pits and mounds following windthrow events should be considered as an effective factor influencing soil features(i.e., density, texture, water content, p H, organic C, total N, available nutrients and earthworm density/biomass) and especially GHG fluxes. Results showed that MT acted as a sink for N2O(-0.010 mg N2 O m-2d-1) and CH4(-0.257 mg CH4m-2d-1) fluxes and also produced lower CO2 concentrations(0.095 mg CO2 m-2d-1) than PB(0.207 mg CO2 m-2d-1) and UA(0.098 mg CO2 m-2d-1). As a consequence, a separation into pits/mounds would be important for a precise budgeting of greenhouse gases.

关键词：温室气体森林土壤土壤特征通量事件风倒 CO2浓度温带

Isogeometric analysis of free-form Timoshenko curved beams including the nonlinear effects of large deformations

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Acta Mechanica Sinica 2018年第4期34卷 728-743页

作者： seyed Farhad hosseini Ali Hashemian Behnam Moetakef-Imani Saied Hadidimoud Sun-Air Research Institute Ferdowsi University of Mashhad Department of Mechanical Engineering Hakim Sabzevari University Department of Mechanical Engineering Ferdowsi University of Mashhad Centre for Manufacturing and Materials Engineering Coventry University

In the present paper, the isogeometric analysis（IGA） of free-form planar curved beams is formulated based on the nonlinear Timoshenko beam theory to investigate the large deformation of beams with variable curvature. Based on the isoparametric concept, the shape functions of the field variables（displacement and rotation） in a finite element analysis are considered to be the same as the non-uniform rational basis spline（NURBS） basis functions defining the geometry. The validity of the presented formulation is tested in five case studies covering a wide range of engineering curved structures including from straight and constant curvature to variable curvature beams. The nonlinear deformation results obtained by the presented method are compared to well-established benchmark examples and also compared to the results of linear and nonlinear finite element analyses. As the nonlinear load-deflection behavior of Timoshenko beams is the main topic of this article, the results strongly show the applicability of the IGA method to the large deformation analysis of free-form curved beams. Finally, it is interesting to notice that, until very recently, the large deformations analysis of free-form Timoshenko curved beams has not been considered in IGA by researchers.

关键词： Curved beams Nonlinear Timoshenko beam theory Large deformation Isogeometric analysis NURBS curves