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Process−microstructure−properties relationship in Al−CNTs−Al2O3 nanocomposites manufactured by hybrid powder metallurgy and microwave sintering process

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Transactions of Nonferrous Metals Society of China 2020年第9期30卷 2339-2354页

作者： meysam toozandehjani Farhad OSTOVAN Khairur Rijal JAMALUDIN Astuty AMRIN Khamirul Amin MATORI Ehsan SHAFIEI Razak Faculty of Technology and Informatics Universiti Teknologi Malaysia Kuala Lumpur54100 Jalan SemarakKuala LumpurMalaysia Department of Material Science and Engineering Islamic Azad UniversityBandar Abbas BranchBandar AbbasHormozganIran Department of Physics Faculty of ScienceUniversiti Putra Malaysia43400SerdangSelangorMalaysia

Al−2CNTs−xAl2O3 nanocomposites were manufactured by a hybrid powder metallurgy and microwave sintering *** correlation between process-induced microstructural features and the material properties including physical and mechanical properties as well as ultrasonic parameters was *** was found that physical properties including densification and physical dimensional changes were closely associated with the morphology and particle size of nanocomposite *** maximum density was obtained by extensive particle refinement at milling time longer than 8 h and Al2O3 content of 10 wt.%.Mechanical properties were controlled by Al2O3 content,dispersion of nano reinforcements and grain *** optimum hardness and strength properties were achieved through incorporation of 10 wt.%Al2O3 and homogenous dispersion of CNTs and Al2O3 nanoparticles(NPs)at 12 h of milling which resulted in the formation of high density of dislocations and extensive grain size *** both longitudinal and shear velocities and attenuation increase linearly by increasing Al2O3 content and milling *** variation of ultrasonic velocity and attenuation was attributed to the degree of dispersion of CNTs and Al2O3 and also less inter-particle spacing in the *** larger Al2O3 content and more homogenous dispersion of CNTs and Al2O3 NPs at longer milling time exerted higher velocity and attenuation of ultrasonic wave.

关键词： hybrid composite aluminum composites powder metallurgy microwave sintering microstructure mechanical properties ultrasonic velocity ultrasonic attenuation

Influence of rotational speed on mechanical properties of friction stir lap welded 6061-T6 Al alloy

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Transactions of Nonferrous Metals Society of China 2014年第4期24卷 1004-1011页

作者： Firouz FADAEIFARD Khamirul Amin MATORI meysam toozandehjani Abdul Razak DAUD Mohd Khairol Anuar Mohd ARIFFIN Norinsan Kamil OTHMAN Farhad GHARAVI Abdul Hadi RAMZANI Farhad OSTOVAN Materials Synthesis and Characterization Laboratory Institute of Advanced TechnologyUniversiti Putra Malaysia Department of Physics Faculty of Science Universiti Putra Malaysia Department of Mechanical and Manufacturing Faculty of Engineering Universiti Putra Malaysia School of Applied Physics Faculty of Science and Technology Universiti Kebangsaan Malaysia

The effect of rotational speed on macro and microstructures, hardness, lap shear performance and failure mode of friction stir lap welding on AA6061-T6 Al alloy with 5 mm in thickness was studied by field-emission scanning electron microscopy （FE-SEM）. The results represent much closer hardness distribution in the upper and lower plates at the lowest rotational speed. It indicates the Fe-compounds in the fracture surface of the nugget zone by EDX.

关键词： aluminum alloy friction stir lap welding mechanical properties

Theoretical Investigation of Hydrogen Sulfide Adsorption on the Surface of F Functionalized Carbon and Carbon Silicon Nanotubes (7,0) in the Gas Phase and Water

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Chinese Journal of Structural Chemistry 2017年第3期36卷 387-395页

作者： meysam Najafi Young Researchers and Elite Club Kermanshah BranchIslamic Azad University Kermanshah Iran

In order to develop a sensor for the detection of toxic H_2S molecule,the interactions of C–NT and CSi–NT with H_2S molecule were investigated by density functional theory calculations. The effects of F functionalization and water on the adsorption of H_2S gas on C–NT and CSi–NT surfaces were investigated. The studied nanotubes can interact with the H_2S molecule effectively and so adsorptions of H_2S on studied nanotubes are exothermic and possible from the energetic viewpoint. Replacing the C atoms of C–NT with Si atoms may be a good strategy for improving the sensitivity of C–NT towards H_2S. F functionalization and water cause an increase and decrease in the absolute adsorption energy（Ead） values of H_2S on the studied nanotubes,respectively. There are good linearity dependencies between Ead and orbital energy values of studied nanotubes. The Ead and orbital energy values of studied nanotubes can be considered as important parameters to propose suitable nanotubes with increased potential of H_2S adsorption.

关键词： DFT water nanotube H_2S functionalization

Antioxidant Activity of Sesamol Derivatives and Their Drug Delivery via C60 Nanocage: a Theoretical Study

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Chinese Journal of Structural Chemistry 2019年第2期38卷 195-200,165页

作者： meysam Najafi Medical Biology Research Center Kermanshah University of Medical Sciences

The antioxidant activity of sesamol derivatives and their drug delivery via fullerene were investigated. Fullerene can interact with sesamol derivatives, and their adsorptions were possible from the energetic viewpoint. Adding the NH_2 group to sesamol can improve the sensitivity of sesamol toward fullerene surface. The NH_2 and OMe substitutions increase the antioxidant activity of sesamol. The results can also be used to select novel sesamol derivatives with higher antioxidant activity and higher drug delivery ability.

关键词： drug delivery fullerene sesamol adsorption energy and water

Antioxidant Properties of Substituted Thymols and Their Adsorption on Aluminum Phosphide(AlP)Nanotube(8,0)as Controlled Drug Delivery Device:Theoretical Study in Gas Phase and Ethanol

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Chinese Journal of Structural Chemistry 2017年第2期36卷 197-203页

作者： meysam Najafi Medical Biology Research Center Kermanshah University of Medical SciencesKermanshah 67149-67346Iran

We have studied the adsorption of thymol derivatives on AlP-nanotube surface by using density functional calculations in gas phase. Also the antioxidant activity of thymol was investigated in gas phase and ethanol. The effects of NMe2, OEthyl and Me substituents on the antioxidant activity and adsorption ability of thymol on AlP-nanotube were investigated. Results show that AlP-nanotube can effectively interact with substituted thymols, so their adsorptions are exothermic and experimentally possible from the energetic viewpoint. Results also show that, replacing NMe2 group in the x position of thymol may be a good strategy to improve the sensitivity of thymol toward AlP-nanotube surface. The NMe2 and OEthyl substitutions decrease the BDE and IP values and increase the antioxidant activity of thymol. The BDE and IP values of thymols have linear dependencies with corresponding Ead values. These can be utilized to select novel thymol derivatives with higher antioxidant activity and drug delivery ability.

关键词： nanotube ethanol viewpoint Adsorption utilized antioxidant toward substituted apparent energetic

Antioxidant Activity of Substituted Enterolactone Derivatives in the Gas Phase and Water

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Chinese Journal of Structural Chemistry 2013年第9期32卷 1374-1386页

作者： meysam Najafi Department of physiology Faculty of Medicine Kermanshah University of Medical Sciences

The antioxidant activity of ortho and meta substituted Enterolactone derivatives has been investigated in the gas phase and *** reaction enthalpies of antioxidant activity of the studied derivatives have been calculated and compared with the corresponding values of *** show that EWG substituents increase the BDE and IP,while the EDG ones rise in the *** Enterolactone derivatives with the lowest BDE,IP and PA values were identified as the compounds with high antioxidant *** show that the substituents in the ortho position have high potential for the synthesis of novel Enterolactone *** show that Enterolactone derivatives can processes their protective role via HAT and SPLET mechanism in gas phase and solvent,*** calculated reaction enthalpies of the substituted Enterolactones have linear dependence with Hammett constants and EHOMO that can be utilized in the selection of suitable substituents for the synthesis of novel antioxidants based on Enterolactone.

关键词： antioxidant Enterolactone substituent effect DFT EHOMO

Adsorption of Synthesized Pyridinyl-pyrazolecarbox Amide Derivatives as Anti-fungal on the Surface of Ge-nanotube(6,6)

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Chinese Journal of Structural Chemistry 2017年第10期36卷 1673-1678页

作者： meysam Najafi Young Researchers and Elite Club Kermanshah Branch lslamic Azad University Kermanshah Iran

The anti-fungal activities of synthesized pyridinyl-pyrazole-carbox amide derivatives 1a^1c were investigated via theoretical parameters. The obtained results in present paper were compared with the reported experimental results. Experimental results show that derivative 1a has the highest and derivative 1c the lowest anti-fungal activity. The interactions of derivatives 1a^1c with Ge-nanotube（6, 6） were investigated, and also quantum molecular descriptors of derivatives 1a^1c were calculated. Results show that, derivatives 1a^1c can interact with Ge-nanotube（6, 6） effectively, and their adsorptions were exothermic and possible from the theoretical viewpoint. The absolute ΔEad and ΔGad values of derivative 1a on Ge-nanotube（6, 6） were higher than the absolute ΔEad and ΔGad values of 1 b and 1c. Derivative 1a has the highest absolute μ, ω and ΔN values. The theoretical and experimental trends of anti-fungal activity of derivatives 1a^1c were similar, successfully.

关键词： pyridinyl-pyrazole-carbox amide adsorption energy nanotube anti-fungal and chemical potential

Studies on the Ability of Carbon Nanotube(5,5) as Drug Carrier and Anticancer Properties of Benzylthio-indolyl-triazol-amine Derivatives

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Chinese Journal of Structural Chemistry 2017年第10期36卷 1679-1684页

作者： meysam Najafi Young Researchers and Elite Club Kermanshah Branch Islamic Azad University Kermanshah Iran

The anticancer activities of synthesized benzylthio-indolyl-triazol-amine derivatives 1a^1c were investigated via theoretical scales. The experimental results show that derivative 1a has the highest anticancer activity, and 1c has the lowest one. The interactions of 1a^1c with C-nanotube（5,5） were investigated. Also the quantum molecular descriptors of derivatives 1a^1c were calculated and the results show that they can interact with C-nanotube（5,5） effectively. The adsorptions of 1a^1c on C-nanotube（5,5） surface were exothermic and experimentally possible from the energetic viewpoint. The results indicated that ΔEad and ΔGad values of derivative 1a on C-nanotube（5,5） were higher than those of the corresponding derivatives 1b and 1c, so 1a has the highest ｜μ｜, ω and ｜？N｜ values and the lowest value, and the trends of theoretical anticancer activities of 1a^1c are similar to the experimental values successfully.

关键词： benzylthio-indolyl-triazol-amine adsorption energy nanotube anticancer and chemical potential

Study of Oxidation of Carbon Monoxide on the Surface of Sn-doped Carbon Nanotube

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Chinese Journal of Structural Chemistry 2019年第4期38卷 524-532页

作者： meysam Najafi Medical Biology Research Center Kermanshah University of Medical Sciences

In recent years, the discovery of suitable catalyst to the oxidation of carbon monoxide(CO) is a major concern in industry. In present study, in the first step the carbon nanotube(CNT) with Sn was doped and the surface of Sn-CNT via O_2 molecule was activated. In the second step the CO oxidation on the surface of Sn-CNT via Langmuir Hinshelwood(LH) and Eley Rideal(ER) mechanisms was investigated. Results show that O_2-Sn-CNT can oxidize the CO molecule via Sn-CNT-O-O* + CO → Sn-CNT-O-O*-CO → Sn-CNT-O* + CO_2 and Sn-CNT-O* + CO → Sn-CNT + CO_2 reactions. Results show that CO oxidation on activated Sn-CNT surface via the ER mechanism has lower energy barrier than LH mechanism. Finally, calculated parameters reveal that activated Sn-CNT is an acceptable catalyst with high potential to the oxidation of CO molecule.

关键词： catalyst nanostructure metal adsorption oxidation reaction adsorption energy