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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

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

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

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

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

Impact of land-use management on nitrogen transformation in a mountain forest ecosystem in the north of Iran

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Journal of Forestry Research 2013年第1期24卷 115-119页

作者： Maryam Asadiyan seyed mohammad Hojjati mohammad reza Pourmajidian Asghar fallah Sari Agricultural Sciences and Natural Resources University Sari-Iran.

Soil inorganic N is one of the most important soil quality indexes, which may be influenced by land-use change. The historical conversion of land-use from native vegetation to agriculture resulted in sharp declines in soil N dynamics. This study was conducted to determine the soil inorganic N concentrations and net N mineralization rate in four common types of land-uses in the mountain forest area in the north of Iran, namely arable land, pine plantation, ash plantation, and beech stand. The soil samples were taken from top mineral soil layer （5 cm） in each site randomly （n=6） during August- September 2010. Beech stand and ash plantation showed significantly higher total nitrogen compared with arable land and pine plantation, while extractable NH4 ＋-N concentration was significantly greater in Beech stand compare to arable soils （p〈0.05）. No significantly difference was found in Net N mineralization, net nitrification and net ammonification rates among different land-uses. Results showed that net N mineralization and ammonification were occurred just in the soil of Ash plantation during the incubation time. Our findings suggested that conversion of Hyrcanian forests areas to pine plantation and agricultural land can disrupt soil natural activities and affect extremely soil quality.

关键词： soil quality net N mineralization nitrogen dynamic land use Hyrcanian forest Alandan.

Synthesis of novel disulfide-bridged dilactam crown ethers

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Chinese Chemical Letters 2007年第12期18卷 1439-1442页

作者： Hossein Eshghi seyed mohammad seyedi Reza Sandarooss Department of Chemistry Ferdowsi University of MashhadMashhad 91775-1436Iran

The novel macrocyclic dilactams with redox-switched disulfide linkage were synthesized. These compounds were obtained from 2,2′-dithiodibenzoyl chloride in the macrocyclization step by fast addition method in moderat... 详细信息

关键词： Dilactam Disulfide Fast addition Macrocyclization Redox Switchable

Solvent extraction of rubidium from gold waste using conventional SX and new CFE methods

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Rare Metals 2015年第11期34卷 818-828页

作者： mohammad Reza Tavakoli mohammadi seyed mohammad Javad Koleini Sepideh Javanshir Hossein Abolghasemi Mahmoud Abdollahy Mineral Processing Department Tarbiat Modares University Mining Engineering Department University of Birjand Oil and Gas Center of Excellence School of Chemical Engineering College of Engineering University of Tehran

Solvent extraction（SX） of rubidium（Rb） from leaching filtrate of gold waste（GW） in Mouteh Processing Plant by 18-crown-6（18C6） was studied. High potential of new column flotoextraction（CFE） method in extraction of Rb from dilute solutions was also demonstrated. First, the factors affecting SX of Rb from a synthetic rubidium sulfate solution(containing 100 mg·L-1Rb) were identified.0.05 mol·L-118C6 in kerosene, 0.02 mol·L-1picric acid in aqueous phase, aqueous to organic（A/O） ratio of 1, p H7 and mixing time of 15 min are the optimum values for affective factors. The three-stage precipitation with sodium carbonate, p H adjustment with sulfuric acid and two-stage evaporation and crystallization were conducted to purify the leaching from impurities such as Fe, Al, Mn, Ca and especially competing cations of K and Na. Almost complete extraction of Rb and K from final filtrate containing 0.08 mol·L-1picric acid was performed using 0.2 mol·L-118C6 in kerosene. The Rb and K strippings of 99.12 % and 9.93 %, respectively, are obtained with 2 mol·L-1nitric acid with A/O ratio of 2. Finally, the performance comparison of the CFE and SX methods in similar conditionsshows increased extraction of K and Rb by 16 % and 5 %,respectively, using CFE method.

关键词： Rubidium Gold waste Solvent extraction Column flot