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Application of diffusive transport model for better insight into retardation mechanisms involved in ion-imprinted membrane transport

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Chinese Journal of Chemical Engineering 2016年第9期24卷 1161-1165页

作者： ehsan salehi Department of Chemical Engineering Faculty of Engineering Arak University

Heavy metal removal from water is a great concern for environmentalists and engineers. Ion-imprinted membranes are among the state of the art technologies for selective adsorption of heavy metals from aqueous environment. Dialysis permeation of nickel ions through Ni(II)-imprinted membranes has been thermodynamically studied in our prior work. In current study, the diffusive transport model was developed and then applied for better insight into the retardation mechanisms involved in the ion-imprinted membrane transport. The Sips isotherm model was coupled with the transport model to obtain the governing equation. Chemisorption and physical interactions(bulk diffusion and pore-clogging) were the most probable retardation mechanisms according to the modeling results. Relative retardation factor(η) was also defined as; transport-rate controlled by chemical adsorption to that controlled by physical interactions. With the help of the retardation factor, it was understood that the membrane behavior gradually changes from chemisorption to facilitated transport during permeation time. Effect of important operating parameters such as time, temperature and concentration on transport behavior was also investigated. Results indicated that chemisorption rate is rather higher at lower concentrations, early permeation times and reduced temperatures. In addition, η tabulated greater values for Ni(II) compared to Co(II) due to the imprinting effect.

关键词： Ion-imprinted membrane Mathematical modeling Chemisorption Retardation mechanism

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Extended adsorption transport models for permeation of copper ions through nanocomposite chitosan/polyvinyl alcohol thin affinity membranes

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Chinese Journal of Chemical Engineering 2016年第11期24卷 1527-1532页

作者： ehsan salehi Leila Bakhtiari Mahdi Askari Department of Chemical Engineering Faculty of EngineeringArak University Membrane Research Center Department of Chemical EngineeringRazi University

Transport of copper ions through nanocomposite chitosan/polyvinyl alcohol thin adsorptive membranes has been mathematically investigated in the current study. Unsteady-state diffusive transport model was coupled with the Freundlich isotherm to predict the concentration of the ions in dialysis permeation operation. Pristine model was not successful in predicting the experimental data based upon its low coefficients of determination（0.1

关键词： Modeling Chitosan Nanocomposite membrane adsorbents Copper ion Dialysis

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Chitosan/polyethylene glycol impregnated activated carbons： Synthesis, characterization and adsorption performance

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Frontiers of Chemical Science and Engineering 2017年第4期11卷 575-585页

作者： ehsan salehi Fereshteh Soroush Maryam Momeni Aboulfazl Barati Ali Khakpour . Department of Chemical Engineering Faculty of Engineering Arak University Arak 38156-8-8349 Iran.. Department of Electrical Engineering Faculty of Engineering Arak University Arak 38156-8-8349 Iran.. Arian Fan Azma Company Tehran Iran

Novel modified activated carbons （ACs） with enhanced adsorptive properties were obtained coating by chitosan （CS）, polyethylene glycol （PEG） and blends of the two polymers （0：1, 1：0, 1：1, 1：2 and 2：1 wt/wt） on ACs by an impregnation technique. The adsorption perfor- mances of the pristine, acidified and polymer-impregnated ACs were studied using methylene blue as a model adsorbate. The adsorbents were characterized using Four- ier transform infrared spectroscopy, scanning electron microscopy and abrasion hardness tests. The average coating thicknesses were between 10 to 23 microns. The pore sizes, pore densities and pore capacities of the activated carbons increased as the wt-% PEG in the coating increased. The highest adsorption capacity （424.7 mg/g） was obtained for the chitosan-coated ACs and this adsorption was well described by the Langmuir isotherm model. The kinetic results were best described by the pseudo-second-order kinetic model. The highest rate constant was obtained with the ACs modified with the CS：PEG （2：1） coating and this result was almost 2.6 times greater than that of the unmodified ACs. The CS/PEG impregnated ACs also displayed superior hardness （-90%）, compared to unmodified ACs （-85%）. Overall the chitosan had a greater effect on improving adsorption capacity whereas the polyethylene glycol enhanced the adsorption rate.

关键词： carbon biocomposites impregnation chito-san polyethylene glycol image processing

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A Deep Reinforcement Learning-Based Technique for Optimal Power Allocation in Multiple Access Communications

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Intelligent Automation & Soft Computing 2024年第1期39卷 93-108页

作者： Sepehr Soltani ehsan Ghafourian Reza salehi Diego Martín Milad Vahidi Department of Industrial Engineering College of EngineeringUniversity of HoustonHoustonTX77204USA Department of Computer Science Iowa State UniversityAmesIowaUSA ETSI de Telecomunicación Universidad Politécnica de MadridMadridSpain Faculty of School of Plant and Environmental Sciences Virginia Polytechnic Institute and StateUniversityBlacksburgVirginia24060USA

Formany years,researchers have explored power allocation(PA)algorithms driven bymodels in wireless networks where multiple-user communications with interference are ***,data-driven machine learning methods have become quite popular in analyzing wireless communication systems,which among them deep reinforcement learning(DRL)has a significant role in solving optimization issues under certain *** this purpose,in this paper,we investigate the PA problem in a k-user multiple access channels(MAC),where k transmitters(e.g.,mobile users)aim to send an independent message to a common receiver(e.g.,base station)through wireless *** this end,we first train the deep Q network(DQN)with a deep Q learning(DQL)algorithm over the simulation environment,utilizing offline ***,the DQN will be used with the real data in the online training method for the PA issue by maximizing the sumrate subjected to the source ***,the simulation results indicate that our proposedDQNmethod provides better performance in terms of the sumrate compared with the available DQL training approaches such as fractional programming(FP)and weighted minimum mean squared error(WMMSE).Additionally,by considering different user densities,we show that our proposed DQN outperforms benchmark algorithms,thereby,a good generalization ability is verified over wireless multi-user communication systems.

关键词： Deep reinforcement learning deep Q learning multiple access channel power allocation

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Mathematical model for iron corrosion that eliminates chemical potential parameters

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Chinese Journal of Chemical Engineering 2020年第2期28卷 603-612页

作者： Hadi Seddiqi Ali Sadatshojaie Behzad Vaferi ehsan Yahyazadeh Afshin salehi David AWood Department of Chemical and Petroleum Engineering Sharif University of TechnologyP.O.Box 11365-11155TehranIran Young Researchers and Elite Club Shiraz BranchIslamic Azad UniversityShirazIran Department of Chemistry Sharif University of TechnologyP.O.Box 11365-11155TehranIran DWA Energy Limited BassinghamLincoln LNS 9JPUnited Kingdom

Iron corrosion in acidic media is a natural phenomenon that converts elemental iron to a more chemically-stable form,*** oxide and *** this study,the iron corrosion process is modeled as a completely implicit problem,solved by a novel finite difference model to provide insight into the ionic aspects of corrosion *** new mathematical model eliminates the chemical potential parameters from the corrosion process equations,thereby reducing the need for experimental determination of chemical *** eliminatedchemical-potential-parameters model predicts and quantifies key parameters(concentrations of conjugate base ion,iron(Ⅱ)ion,hydrogen ion,anodic and cathodic potentials,and the electrical current density)associated with the iron corrosion process in acidic *** rigorous derivation and novel application of the eliminated-chemical-potential-parameters model and its results provide new insights into the iron corrosion *** present model is also applicable in any industrial process which is associated with metal *** model helps to guide the design of future corrosion resistant systems,and various experimental studies pertaining to corrosion inhibition techniques.

关键词： Finite difference modeling Implicit solution Iron corrosion process Modeling corrosion process Transient numerical simulation

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Morphometric differentiation between camel and sheep strains of Echinococcus granulosus using computer image analysis system(CIAS)

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Asian Pacific Journal of Tropical Medicine 2012年第1期5卷 58-61页

作者： Gholamreza Mowlavi Mitra salehi Mohammadreza Eshraghian Mohammad Bagher Rokni Majid Fasihi-Harandi ehsan Mohajeran Abdoreza Salahi-Moghaddam Department of Medical Parasitology & Mycology School of Public HealthTehran University of Medical SciencesTehranIran Department of Biostatistics & Epidemiology School of Public HealthTehran University of Medical SciencesTehranIran Department of Medical Parasitology & Mycology Faculty of MedicineKerman University of Medical SciencesKermanIran Azad University of Naragh NaraghIran Department of Medical Parasitology & Mycology Faculty of MedicineHormozgan University of Medical SciencesBandar AbbasIran

Objective:To find importance of morphometrie criterion of larval rostellar hook of Echinococcus granulosus(***) and the easy and reliable method for distinguish sheep and camel strains in epidemiologic ***:Larval rostellar hooks(n=1860) of 31 camel and sheep isolates in Iran,which aheady had been characterized by *** carefully processed by computerized imagime analysis system(CIAS) and acquired data about rostellar books were analyzed using software ***:Measurement analysis of rostellar hooks[mean Iength (24.23±3.12lμm]indicated that length of the large hook was a remarkable parameter for strain *** analysis demonstrated that CIAS could be used as a reliable tool to distinguish camel from sheep strains with high sensitivity(95.2%) and specificity(91.5%). Conclusions:CIAS as a specific,sensitive,economic,fast,and reliable means might be used for differentiation of *** *** perimeter and area were measured by digital technology,they were not shown as discriminative criterion as total hook length did.

关键词： Morphometry CIAS Echinococcus granulosus Strains Binary logistic regression

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Magnetite / Polyvinylpyrrolidone Nanocomposite: Green Simple Fabrication and characterization

Magnetite / Polyvinylpyrrolidone Nanocomposite: Green Simple...

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International Conference on Chemistry and Chemical Engineering （ICCCE 2011）

作者： Mohammad Taghi salehi Mojtaba Nasr-Esfahani Ali Sharifian-Esfahani ehsan Ekramian Department of Material Science and Engineering Najafabad Branch Islamic Azad University Najafabad 85141-43131 Iran

The paper presents results of research on green simple preparing the magnetic nanocomposite based on Fe3O4 nanoparticles. The synthesis and assembly of magnetite nanoparticles was performed by a one-step procedure. Fe3O4 nanoparticles can be synthesized by Y. Zheng method. Polyvinylpyrrolidone （PVP） homopolymer with molecular weight about 10,000;synthesized by hydrogen peroxide/ascorbic acid as a redox couple initiator in aqueous medium. A kind of nanocomposite with nano Fe3O4 as the core and an absorption layer of PVP molecules surrounding it have been prepared. The PVP modification did not change the crystalline structure of Fe3O4, and the PVP-coated Fe3O4 nanoparticles. The average size of the individual magnetite particles is about 8 nm, calculated by the Scherrer equation The ability to synthesize and assemble monodispersed core-shell nanoparticles is important for exploring the unique properties of nanoscales core- shell, or their combinations in magnetic, catalytic, and biological applications.

关键词： Magnetic nanoparticles Fe3O4 / PVP nanocomposite Particle size Particle density.

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