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Journal of Materials Science & Technology 2012年第1期28卷 73-82页

作者： Ali Khoshakhlagh Ali nazari Gholamreza Khalaj Department of Materials Engineering Science and Research BranchIslamic Azad University Department of Materials Engineering Saveh BranchIslamic Azad University

In this work, compressive, flexural and split tensile strength together with coefficient of water absorption of high performance self-compacting concrete containing different amount of Fe2Os nanoparticles have been investigated. The strength and the water permeability of the specimens have been improved by adding Fe2Os nanoparticles in the cement paste up to 4.0 wt%. Fe203 nanoparticle as a foreign nucleation site could accelerate C-S-H gel formation as a result of increased crystalline Ca（OH）2 amount especially at the early age of hydration and hence increase the strength of the specimens. In addition, Fe203 nanoparticles are able to act as nanofillers and recover the pore structure of the specimens by decreasing harmful pores to improve the water permeability. Several empirical relations have been presented to predict the flexural and the split tensile strength of the specimens by means of the corresponding compressive strength at a certain age of curing. Accelerated peak appearance in conduction calorimetry tests, more weight loss in thermogravimetric analysis and more rapid appearance of peaks related to hydrated products in X-ray diffraction results indicate that Fe203 nanoparticles up to 4 wt% could improve the mechanical and the physical properties of the specimens.

关键词： Water permeability Fe203 nanoparticles Compressive strength Split tensilestrength Flexural strength

Engineered FeVO4/CeO2 nanocomposite as a two-way superior electro-Fenton catalyst for model and real wastewater treatment

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Journal of Environmental Sciences 2020年第11期32卷 110-119页

作者： Shahrbanoo Rahman Setayesh Pegah nazari Roghaye Maghbool Department of Chemistry Sharif University of TechnologyTehran 11155-3516Iran

FeVO4/CeO2 was applied in the electro-Fenton(EF)degradation of Methyl Orange(MO)as a model of wastewater *** results of the characterization techniques indicate that FeVO4 with triclinic structure and face-centered cubic fluorite CeO2 maintained their structures during the nanocomposite *** effect of applied current intensity,initial pollutant concentration,initial pH,and catalyst weight was *** MO removal reached 96.31%and chemical oxygen demand(COD)removal 70%for 60 min of the *** presence of CeO2 in the nanocomposite plays a key role in H2O2 electro-generation as a significant factor in the electro-Fenton(EF)*** metal leaching from FeVO4/CeO2 was negligible(cerium 4.1%,iron 4.3%,and vanadium 1.7%),which indicates that the active species in the nanocomposite are strongly interacting with each other and are *** performance of the nanocatalyst in real wastewaters,salty,and binary systems was acceptable and the pollutions were removed *** synergistic effect between V,Fe,and Ce could be account as the reason for the respectable function of FeVO4/*** electron transfer proceeds via Haber-Weiss mechanism.A degradation pathway was proposed through by-products analysis using gas chromatography-mass spectrometry(GC–MS)*** pseudo-first-order kinetic model described the obtained experimental results(R2=0.9906).The electro-Fenton system efficiency was improved by adding *** nanocomposite preserved almost its efficiency after six *** obtained results demonstrate that the synergistic catalyst(FeVO4/CeO2)has the capability to introduce as a promising replacement of conventional catalysts in the electro-Fenton processes with brilliant proficiency.

关键词： Electro-Fenton Methyl Orange Synergistic effect Persulfate FeVO4

Effects of Al_2O_3 nanoparticles on properties of self compacting concrete with ground granulated blast furnace slag (GGBFS) as binder

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Science China(Technological Sciences) 2011年第9期54卷 2327-2338页

作者： Ali nazari Shadi RIAHI Department of Materials Science and Engineering Saveh BranchIslamic Azad University

In this work, strength assessments and percentage of water absorption of self compacting concrete containing ground granulated blast furnace slag （GGBFS） and A1203 nanoparticles as binder have been investigated. Portland cement was replaced by different amounts of GGBFS and the properties of concrete specimens were investigated. Although it negatively impacts the physical and mechanical properties of concrete at early ages of curing, GGBFS was found to improve the physical and mechanical properties of concrete up to 45 wt% at later ages. A1203 nanoparticles with the average particle size of 15 nm were added partially to concrete with the optimum content of GGBFS and physical and mechanical properties of the specimens were measured. A1203 nanoparticle as a partial replacement of cement up to 3.0 wt% could accelerate C-S-H gel formation as a result of increased crystalline Ca（OH）2 amount at the early ages and hence increase strength and improve the resistance to water permeability of concrete specimens. The increase of the A1203 nanoparticles＇ content by more than 3.0 wt% would cause the reduction of the strength because of the decreased crystalline Ca（OH）2 content required for C-S-H gel formation. Several empirical relationships have been presented to predict flexural and split tensile strength of the specimens by means of the corresponding compressive strength at a certain age of curing. Accelerated peak appearance in conduction calorimetry tests, more weight loss in thermogravimetric analysis and more rapid appearance of the peaks related to hydrated products in X-ray diffraction results, all indicate that A1203 nanoparticles could improve mechanical and physical properties of the concrete specimens.

关键词： concrete ground granulated blast furnace slag (GGBFS) Al203 nanoparticles compressive strength, flexural and splittensile strength pore structure thermogravimetric analysis conduction calorimetry

Synthesis of BSCFO Ceramics Membrane Using a Simple Complexing Method and Experimental Study of Sintering Parameters

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Journal of Materials Science & Technology 2010年第10期26卷 914-920页

作者： Ensieh Ganji Babakhani Jafar Towfighi Khodadad nazari Gas Department Research Institute of Petroleum Industry (RIPI) Chemical Engineering Department Engineering FacultyUniversity of Tarbiat Modares Chemical and Petrochemical Department Research Institute of Petroleum Industry (RIPI)

A new complexing agent Ethylene Diamine N,N,N,N-Tetra N-Acetyl Diamine（EDTNAD）,was used for Ba0.5Sr0.5Co0.8Fe0.2O3-δ（BSCFO） *** chemicals such as ammonia,nitric acid and citric acid were eliminated in comparison to the commonly used EDTA *** agent makes complexing synthesis method a single step and causes more homogeneity in the liquid and solid *** sintering process was studied at temperatures between 1000 to 1200℃,heating-cooling rates of 1,2,5,10℃/min and dwell time of 2,5,10 and 15 ***-sintered membranes were investigated by X-ray diffraction （XRD）,scanning electron microscopy （SEM）,and density *** the SEM images and X-ray diffraction of the BSCFO disks,it could be seen that above 1100℃,crystal intensity decreased,and melting and deformation of the disk *** results show that in restricted temperature range,1000-1100℃,10% temperature increase leads to about a 4.5% density increase but a 200% increase in dwell time leads to about a 4% density *** could be concluded that the effect of temperature on grain growth,porosity and density is more than that of dwell *** also showed that the heating-cooling rate has no significant effect on grain size and density.

关键词： BSCFO Membrane Sintering Grain size Perovskite

A review on the cracking,baking and leaching processes of rare earth element concentrates

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Journal of Rare Earths 2017年第8期35卷 739-752页

作者： Farzaneh Sadri Amir Mohammad nazari Ahmad Ghahreman Department of Mining Engineering Queen's University 25 Union Street Kingston Ontario K7L 3N6 Canada

Rare earth elements（REE） are a set of seventeen chemical elements in the periodic table, which have been found in a variety classes of minerals in the world. The global demand for REE and their compounds has increased in high-tech applications over the past decades due to their chemical, catalytic, electrical, magnetic, and optical properties. After mining, comminution and ore beneficiation, hydrometallurgical and pyrometallurgical processes are carried out to recover REE compounds. The concentrate cracking is a process wherein the structure of a REE mineral is modified in order to dissolve REE in a weak acid solution. This would be accomplished through various techniques such as alkaline cracking and acid baking. The cracked concentrate is then leached to dissolve REE in a solution and subsequently recover those via neutralization, precipitation or solvent extraction methods. This paper reviewed the cracking and leaching methods applied to REE concentrates to produce an intermediate product for further REE separation.

关键词： rare earth elements alkaline cracking acid baking leaching separation

Effect of Layers Position on Fracture Toughness of Functionally Graded Steels in Crack Divider Configuration

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Journal of Materials Science & Technology 2011年第5期27卷 443-452页

作者： Ali nazari Jamshid Aghazadeh Mohandesi Shadi Riahi Department of Technical and Engineering Sciences Islamic Azad University Department of Mining and Metallurgical Engineering Amirkabir University of Technology

In the present study, fracture toughness of functionally graded steels in crack divider configuration has been modeled. By utilizing plain carbon and austenitic stainless steels slices with various thicknesses and arrangements as electroslag remelting electrodes, functionally graded steels were produced. The fracture toughness of the functionally graded steels in crack divider configuration has been found to depend on the composites＇ type together with the volume fraction and the position of the containing phases. According to the area under stress-strain curve of each layer in the functionally graded steels, a mathematical model has been presented for predicting fracture toughness of composites by using the rule of mixtures. The fracture toughness of each layer has been modified according to the position of that layer where for the edge layers, net plane stress condition was supposed and for the central layers, net plane strain condition was presumed. There is a good agreement between experimental results and those acquired from the analytical model.

关键词： Fracture toughness Modeling Functionally graded steel Crack dividerconfiguration Position of the containing phases

Evaluation of the stability of terraced slopes in clayey gravel soil using a novel numerical technique

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Frontiers of Structural and Civil Engineering 2023年第5期17卷 796-811页

作者： Mehrdad KARAMI Mohammad nazari-SHARABIAN James BRISTOW Moses KARAKOUZIAN Department of Civil and Environmental Engineering and Construction University of NevadaLas VegasLas VegasNV 89154USA Department of Mathematics Engineeringand Computer ScienceWest Virginia State UniversityInstituteWV 25112USA R&D Department Universal Engineering SciencesLas VegasNV 89118USA

Conventional geotechnical software limits the use of the strength reduction method(SRM)based on the Mohr–Coulomb failure criterion to analyze the slope safety factor(SF).The use of this constitutive model is impractical for predicting the behavior of all soil *** the present study,an innovative numerical technique based on SRM was developed to determine SF using the finite element method and considering the extended Cam–clay constitutive model for clayey gravel soil as opposed to the Mohr–Coulomb *** this regard,a novel user subroutine code was employed in ABAQUS to reduce the stabilizing forces to determine the failure surfaces and resist and drive shear stresses on a *** validating the proposed technique,it was employed to investigate the performance of terraced slopes in the context of a case *** impacts of geometric parameters and different water table elevations on the SF were *** results indicated that an increase in the upper and lower slope heights led to a decrease in SF,and a slight increase in the horizontal offset led to an increase in the ***,when the water table elevation was lower than the toe of the terraced slope,the SF increased because of the increase in the uplift force as a resistant component.

关键词： terraced slope safety factor finite element method ABAQUS extended Camclay

The effect of finite duration inputs on the dynamics of a system： Proposing a new approach for cancer treatment

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International Journal of Biomathematics 2015年第3期8卷 155-173页

作者： Mostafa nazari Ali Ghaffari Center of Excellence in Robotics and Control K. N. Toosi University of Technology Pardis St. Tehran 19697 64499 Iran Mechanical Engineering DepartmentK. N. Toosi University of TechnologyPardis St. Tehran 19697 64499 Iran

In this paper, a principal question regarding the effect of inputs on the characteristics of dynamic systems is discussed. Whether an input implemented only for a limited duration, can change the characteristics of a dynamic system such that the behavior of the free system, after eliminating the input, differs from that before acting the input？ In this paper, it is shown that a limited time acted input is not able to change the dynamical properties of a system after its elimination. Regarding the proposed approach, a novel finite duration treatment method is developed for a tumor-immune system. The vaccine therapy is used to change the parameters of the system and the chemotherapy is applied for pushing the system to the domain of attraction of the healthy state. For optimal chemotherapy, an optimal control is used based on state-dependent Riccati equation （SDRE）. It is shown that, in spite of eliminating the treatment （therapeutic inputs）, the system approaches to healthy state conditions. The present analysis suggests that a proper treatment method must change the dynamics of the cancer instead of only reducing the population of cancer cells.

关键词： Cancer stability changeable dynamic properties system.

Polypore fungi of Caucasian alder as a source of antioxidant and antitumor agents

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Journal of Forestry Research 2020年第4期31卷 1381-1390页

作者： Vahide Payamnoor Mohammad Reza Kavosi Jamile nazari Gorgan University of Agricultural Sciences and Natural Resources 098 GorganGolestanIran

Macroscopic fungi on Caucasian alder wood(Alnus subcordata)were identified and tested as a source of betulin and betulinic acid(the most important metabolites of the Betulaceae family)to evaluate levels of phenols,flavonoids and antioxidant *** applanatum,Lenzites betulina,Trichaptum biforme,Rigidoporus ulamrius,Fomes fomentarius,Schizophyllum commune,Auricularia mesenterica,and Trametes versicolor were among those identified,and they differed significantly in the level of betulin and betulinic acid and phenols,flavonoids and antioxidant properties in fungal tissues extracted with methanol and with ethanol(p≤0.01).*** had the most betulin(3.642%)and *** the most betulinic acid(1.413%).All tested fungi had high antioxidant activity,and *** had the highest(97.775%).The highest amounts of phenol(719.993 mg mL-1)and flavonoids(361.403 mg mL-1)were found in the ethanolic extract from *** the results of this study and the low cost and convenient access to these fungi,they should be good sources for producing different drugs.

关键词： Fungi Alder Betulin Betulinic acid Antioxidant

Lattice Boltzmann simulation of natural convection in open end cavity with inclined hot wall

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Applied Mathematics and Mechanics(English Edition) 2015年第4期36卷 523-540页

作者： M.nazari H.SHOKRI A.A.MOHAMAD Department of Mechanical Engineering Shahrood University of Technology Department of Mechanical Engineering Schulich School of EngineeringCentre for Environmental Engineering for Research and EducationUniversity of Calgary

Natural convection in an open end cavity with a hot inclined wall is simulated based on the lattice Boltzmann method （LBM）. The physics of flow and energy transfer in open end cavities are addressed when the hot wall is inclined. The combination of the two topics （open cavity and inclined walls） is the main novelty of the present study. The effects of the angle of the hot inclined wall on the flow field and heat transfer are thoroughly investigated. The Prandtl number is fixed to 0.71 （air）. The Rayleigh number and the angle of the hot inclined wall are varied in the range of 10^4 to 10^6 and 60° to 85°, respectively. The results are presented for two different aspect ratios, i.e., A = 1 and 2. The results obtained with the LBM are also compared with those of the finite volume method （FVM）. The predicted results of the LBM conform to those of the FVM. The results show that by increasing the angle of the hot inclined wall and the aspect ratio of the cavity, the average Nusselt number decreases. The trend of the local Nusselt number on the inclined wall is also discussed.

关键词： lattice Boltzmann method (LBM) natural convection open end cavity,inclined wall