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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

Investigating the structural effect of electrospun nano-fibrous polymeric films on water vapor transmission

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Chinese Journal of Chemical Engineering 2019年第1期27卷 100-109页

作者： seyed Jalil Poormohammadian Parviz Darvishi Abdol mohammad Ghalambor Dezfuli Chemical Engineering Department School of EngineeringYasouj University Physics Department Shahid Chamran University of Ahvaz

Electrospun polymers have many applications in the ***, the structure of these polymers has been less widely considered by *** this work, the structural effect of electrospun and casted films of polyacrylonitrile(PAN) and polyvinylidene fluoride(PVDF) polymers on water vapor transmission were *** of water vapor was measured at 35, 60 and 80 ℃ and different relative *** diffusion coefficients were calculated based on mass changes of the polymer *** water vapor transmission rate(WVTR) was also measured at 35 ℃ and 90% relative *** results indicated that electrospun nano-fibrous polymers(ESNPs) absorb much higher water vapor compared to non-porous casted *** interaction of water molecules with mentioned polymers was investigated based on Flory-Huggins *** Flory-Huggins interaction parameter of electrospun films was less than casted films, suggesting much better interaction of water molecules with electrospun *** was also found that electrospun films have anomalous kinetic behavior and do not obey the Fickian diffusion ***, it was revealed that ESNPs show less resistance to water vapor transmission and they are good candidates for the applications of water vapor separation using membranes.

关键词： Water vapor transmission Polymer structure Nanofiber Electrospinning Porous layer

A simple granulation technique for preparing high-porosity nano copper oxide(Ⅱ) catalyst beads

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Particuology 2011年第5期9卷 480-485页

作者： seyed Javad Ahmadi mohammad Outokesh Morteza Hosseinpour Tahereh Mousavand Jaber Ebne Hayyan Research Laboratory School of Energy Engineering Sharif University of Technology Department of Mechanical Engineering McGill University

A simple and efficient method was developed for fabricating spherical granules of CuO catalyst via a three-step procedure. In the first step, copper oxide nanoparticles were synthesized by hydrothermal decomposition of copper nitrate solution under supercritical condition. Then, they were immobilized in the polymeric matrix of calcium alginate, and followed by high-temperature calcination in an air stream as the third step, in which carbonaceous materials were oxidized, to result in a pebble-type catalyst of high porosity. The produced CuO nanoparticles were characterized by transmission electron microscopy （TEM） that revealed an average size of 5 nm, X-ray diffractometry （XRD）, and thermo gravimetric （TG） analysis. The catalysts were further investigated by BET test for measurement of their surface area, and by temperature-programmed reduction analysis （H2-TPR） for determination of catalytic activity. The results demonstrated that immobilization of the CuO nanoparticle in the polymeric matrix of calcium alginate, followed by calcination at elevated temperatures, could result in notable mechanical strength and enhanced catalytic activity due to preservation of the high surface area, both valuable for practical applications.

关键词： CuO nanoparticles Catalyst Hydrothermal synthesis Supercritical water Granulation Calcium alginate

Sacrificial piles as a countermeasure against local scour around underwater pipelines

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Water Science and Engineering 2024年第2期17卷 187-196页

作者： Forough Raeisi seyed mohammad Ali Zomorodiann Masih Zolghadr Hazi mohammad Azamathulla Department of Water Engineering Shiraz UniversityShiraz ***Iran Department of Water Sciences Engineering Jahrom UniversityJahrom ***Iran Department of Civil and Environmental Engineering The University of the West IndiesSt.Augustine CampusTrinidad 331310Republic of Trinidad and Tobago

Local scour around pipelines crossing rivers or in marine environments is a significant *** can lead to failure of the pipelines resulting in environmental side effects and economic *** study developed an experimental method to reduce local scour around pipelines with a steady flow of clear water by installing cylindrical and cubical sacrificial *** sizes of sacrificial piles were examined in a linear *** piles were installed on the upstream side of the pipeline at three *** scour depth reduction rates below the pipeline were *** results showed that sacrificial piles could protect a pipeline from local scour.A portion of scoured sediment around the sacrificial piles was deposited beneath the *** sediment accumulation reduced the scour depth beneath the *** of the experimental results demonstrated that the size of piles(d),the spacing between piles,and the distance between the pipe and piles(Xp)were the variables that reduced the maximum scour beneath the pipeline with a diameter of *** the piles with d=0.40D and 0.64D,X_(p)=4OD was the optimal distance to install a group of piles,and cubical piles could mitigate scour more effectively than cylindrical piles under similar *** the piles with d=D,the greatest reduction in scour depth was achieved at X_(p)=50D with any desired spacings between piles,and cylindrical piles in this dimension could protect the pipeline against scour more effectively than cubical piles.

关键词： Clear water River crossing pipeline Local scour Self-burial process Sediment transport

Two-dimensional MOF-based materials:Preparations and applications as electrodes in Li-ion batteries

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Journal of Energy Chemistry 2024年第10期97卷 388-418,I0008页

作者： Narges Nobakht Seyyed Ahmad Etghani mohammad Hosseini seyed Hamed Aboutalebi Condensed Matter National Laboratory Institute for Research in Fundamental SciencesTehran 19395-5531Iran School of Biological Sciences Institute for Research in Fundamental SciencesTehran 19395-5746Iran BattScout Company London RoadBishopdownSalisbury SP13EnglandUnited Kingdom

Two-dimensional(2D)metal-organic frameworks(MOFs)are rapidly emerging as a unique class of mushrooming family of 2D materials offering distinctive features,such as hierarchical porosity,extensive surface area,easily available active sites,and versatile,adaptable *** promising characteristics have positioned them as highly appealing alternatives for a wide range of applications in energy storage technologies,including lithium ***,the poor conductivity and limited stability of 2D MOFs have limited their real applications in electrochemical energy *** limitations have therefore warranted ongoing research to enhance the performance of 2D *** the significance of 2D MOF-based materials as an emerging class of advanced materials,a multitude of strategy has been devised to address these challenges such as synthesizing 2D conductive MOFs and derivatives along with 2D MOF *** promising approach involves the use of 2D MOF derivatives,including transition metal oxides,which due to their abundant unsatu rated active metal sites and shorter diffusion paths,offer superior electrochemical ***,by combining pristine 2D MOFs with other materials,hybrid 2D MOF materials can be *** hybrids,with their enhanced stability and conductivity,can be directly utilized as active materials in lithium *** the present review,we categorize 2D MOF-based materials into three distinct groups:pristine 2D MOFs,2D MOFderived materials,and 2D MOF hybrid *** synthesis methods for each group,along with their specific applications as electrode materials in lithium-ion batteries,are discussed in *** comprehensive review provides insights into the potential of 2D MOFs while highlighting the opportunities and challenges that are present in this evolving field.

关键词： Li-ion batteries 2D materials 2D metal-organic frameworks Energy storage Synthesis

Speaker adapted dynamic lexicons containing phonetic deviations of words

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2009年第10期10卷 1461-1475页

作者： Bahram VAZIRNEZHAD Farshad ALMASGANJ seyed mohammad AHADI Ari CHANEN Biomedical Engineering Department Amirkabir University of Technology Language and Knowledge Management Research Lab School of Information TechnologiesUniversity of Sydney Electrical Engineering Department Amirkabir University of Technology

Speaker variability is an important source of speech variations which makes continuous speech recognition a difficult *** automatic speech recognition(ASR) models to the speaker variations is a well-known strategy to cope with the *** all such techniques focus on developing adaptation solutions within the acoustic models of the ASR *** variations of the acoustic features constitute an important portion of the inter-speaker variations,they do not cover variations at the phonetic *** variations are known to form an important part of variations which are influenced by both micro-segmental and suprasegmental ***-speaker phonetic variations are influenced by the structure and anatomy of a speaker's articulatory system and also his/her speaking style which is driven by many speaker background characteristics such as accent,gender,age,socioeconomic and educational *** effect of inter-speaker variations in the feature space may cause explicit phone recognition *** errors can be compensated later by having appropriate pronunciation variants for the lexicon entries which consider likely phone misclassifications besides *** this paper,we introduce speaker adaptive dynamic pronunciation models,which generate different lexicons for various speaker clusters and different ranges of speech *** models are hybrids of speaker adapted contextual rules and dynamic generalized decision trees,which take into account word phonological structures,rate of speech,unigram probabilities and stress to generate pronunciation variants of *** the set of speaker adapted dynamic lexicons in a Farsi(Persian) continuous speech recognition task results in word error rate reductions of as much as 10.1% in a speaker-dependent scenario and 7.4% in a speaker-independent scenario.

关键词： Pronunciation models Continuous speech recognition Lexicon adaptation

Mesoscale eddies and their dispersive environmental impacts in the Persian Gulf

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Chinese Physics B 2020年第8期29卷 363-371页

作者： Amin Raeisi Abbasali Bidokhti seyed mohammad Jafar Nazemosadat Kamran Lari Faculty of Natural Resources and Environment Science and Research BranchIslamic Azad UniversityTehran ***Iran Geophysics Institute University of TehranTehran ***Iran Department of Water Engineering Oceanic and Atmospheric Research CenterShiraz UniversityShiraz ***Iran Department of Physical Oceanography Faculty of Marine Science and TechnologyTehran North BranchIslamic Azad UniversityTehran ***Iran

As the mesoscale eddies in oceans and semi-enclosed seas are significant in horizontal dispersion of pollutants,we investigate the seasonal variations of these eddies in the Persian Gulf(PG)that are usually generated due to seasonal winds and baroclinic *** sea surface height(SSH)data from 2010 to 2014 of AVISO are used to identify and track eddies,using the SSH-based *** seasonal horizontal dispersion coefficients are estimated for the PG,using the properties of *** results show an annual mean of 78 eddies with a minimum lifetime of one *** of the eddies are predominantly cyclonic(59.1%)and have longer lifetimes and higher diffusion coefficients than the anti-cyclonic *** eddy activity is higher in warm seasons,compared to that of cold *** locations with high eddy diffusion coefficients are high-risk areas by using maps of horizontal eddy diffusion coefficients,perilous times and locations of the release of pollutants are specified to be within the longitude from 51.38°E to 55.28°*** mentioned areas are located from the Strait of Hormuz towards the northeast of the PG,closer to Iranian ***,July can be considered as the most dangerous time of pollution release.

关键词： Persian Gulf mesoscale eddies marine pollution horizontal eddy diffusion coefficient

An Efficient Hybrid Model Based on Modified Whale Optimization Algorithm and Multilayer Perceptron Neural Network for Medical Classification Problems

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Journal of Bionic Engineering 2022年第5期19卷 1504-1521页

作者： Saeid Raziani Sajad Ahmadian seyed mohammad Jafar Jalali Abdolah Chalechale Department of Computer Engineering Razi UniversityKermanshah ***Iran Faculty of Information Technology Kermanshah University of TechnologyKermanshah ***Iran Institute for Intelligent Systems Research and Innovation(IISRI) Deakin UniversityWaurn PondsMelbourne 3217Australia

Feedforward Neural Network(FNN)is one of the most popular neural network models that is utilized to solve a wide range of nonlinear and complex *** models such as stochastic gradient descent have been developed to train ***,they mainly suffer from falling into local optima leading to reduce the accuracy of ***,the convergence speed of training process depends on the initial values of weights and biases in ***,these values are randomly determined by most of the training *** deal with these issues,in this paper,we develop a novel evolutionary algorithm by modifying the original version of Whale Optimization Algorithm(WOA).To this end,a nonlinear function is introduced to improve the exploration and exploitation phases in the search process of ***,the modified WOA is applied to automatically obtain the initial values of weights and biases in FNN leading to reduce the probability of falling into local *** addition,the FNN model trained by the modified WOA is used to develop a classification approach for medical diagnosis *** medical diagnosis datasets are utilized to evaluate the efficiency of the proposed ***,four evaluation metrics including accuracy,AUC,specificity,and sensitivity are used in the experiments to compare the performance of classification *** experimental results demonstrate that the proposed method is better than other competing classification models due to achieving higher values of accuracy,AUC,specificity,and sensitivity metrics for the used datasets.

关键词： Feed forward neural network Meta-heuristic algorithm Whale optimization algorithm Optimization Classification Bionic algorithm

Texture evolution and mechanical anisotropy of an ultrafine/nano-grained pure copper tube processed via hydrostatic tube cyclic expansion extrusion

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International Journal of Minerals,Metallurgy and Materials 2022年第12期29卷 2241-2251页

作者： seyed Moien Faregh Ghader Faraji Mahmoud Mosavi Mashhadi mohammad Eftekhari School of Mechanical Engineering College of EngineeringUniversity of TehranTehran 11155-4563Iran

Texture evolution and mechanical anisotropic behavior of an ultrafine-grained(UFG)pure copper tube processed by recently introduced method of hydrostatic tube cyclic expansion extrusion(HTCEE)was *** the UFG tube,different deformation behavior and a significant anisotropy in tensile properties were recorded along the longitudinal and peripheral *** HTCEE process increased the yield strength and the ultimate strength in the axial direction by 3.6 and 1.67 times,***,this process increased the yield strength and the ultimate strength in the peripheral direction by 1.15 and 1.12 times,*** ratio of ultimate tensile strength in the peripheral direction to that in the axial direction,as a criterion for mechanical anisotropy,are 1.7 and 1.16 for the as-annealed coarse-grained and the HTCEE processed UFG tube,*** results are indicative of a reducing effect of the HTCEE process on the mechanical ***,after HTCEE process,a low loss of ductility was observed in both directions,which is another advantage of HTCEE *** measurements revealed a slight increment of hardness values in the peripheral direction,which is in agreement with the trend of tensile *** analysis was conducted in order to determine the oriental distribution of the *** obtained{111}pole figures demonstrate the texture evolution and reaffirm the anisotropy observed in mechanical *** electron microscopy micrographs showed that different modes of fracture occurred after tensile testing in the two orthogonal directions.

关键词： severe plastic deformation ultrafine grained hydrostatic tube cyclic expansion extrusion anisotropy texture

Assessment of assembly shape and geometric effects on amplification of shear waves using discrete element method

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Particuology 2022年第7期20卷 85-99页

作者： Leila Karbor seyed Majdeddin Mir mohammad Hosseini Ahad Bagherzadeh Khalkhali Civil and Environmental Engineering Faculty Amirkabir University of TechnologyTehranIran Civil Engineering Faculty Science and Research BranchIslamic Azad UniversityTehranIran

The discrete element method(DEM)is a capable tool used to simulate shear wave propagation in granular assemblies for many *** have studied assembly shapes such as rectangles(in 2D simulations)or cylinders and cubes(in 3D simulations).This paper aimed to qualify the effect of assembly shape on the shear wave propagation and maximum amplification in the vertical plane(horizontal and vertical directions)caused by this *** this end,shear wave propagations in different assembly shapes such as rectangle,trapezium,and triangle with rigid boundary conditions were simulated.A sine wave pulse was applied with a point source by moving a particle as the transmitter *** evaluate the shear wave velocity of the assemblies,the transmitter and receiver particles were *** the simulations were performed with 2D DEM which is a useful tool to determine the amount and location of the maximum amplification factor of the assembly in both horizontal and vertical *** advantage of this study was assessing the effect of parameters such as input wave frequency,assembly height,shape,and aspect ratios on the amplification of the input waves.

关键词： Wave propagation Granular assembly DEM Assembly shape Shear wave