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Chinese Journal of Chemical Engineering 2020年第1期28卷 318-327页

作者： Fatemeh jafari Navid Nasirizadeh mohammad Mirjalili Department of Textile and Polymer Engineering Yazd BranchIslamic Azad UniversityYazdIran

A novel carbon ceramic electrode consisting of Cu NPs and MWCNT was developed to treat reactive orange 84(RO84) wastewater using ultrasound-assisted electrochemical degradation. The proposed electrode generated more hydroxyl radicals than non-nanoparticle electrodes did. In addition, a new electrochemical sensor was applied to determine residue RO84 in an aqueous medium during discoloration. This sensor is based on a glassy carbon electrode modified with gold nanourchins and graphene oxide and can detect RO84 concentration in the range of 1.0–1200 μmol·L^-1 with the detection limit of 0.03 μmol·L^-1. The degradation effects of the modified electrode on RO84 were evaluated systematically with different initial pH values, time durations, and amounts of Cu NPs and MWCNT. The results suggested that the removal efficiency of RO84 was approximately 83% after120 min of electrolysis in a phosphate buffer with pH 8.0 using a carbon ceramic electrode made with 4.0 wt%Cu NPs and 4.0 wt% MWCNT. The possible mechanism of RO84 degradation was monitored by gas chromatography–mass spectrometry, and degradation pathways were proposed.

关键词： Electrochemical degradation Carbon ceramic nanocomposite Reactive dye Copper nanoparticles

Intermetallic growth behavior during post deformation annealing in multilayer Ti/Al/Nb composite interfaces

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International Journal of Minerals,Metallurgy and Materials 2022年第8期29卷 1608-1617页

作者： R.jafari B.Eghbali Department of Materials Engineering Faculty of EngineeringUrmia UniversityP.O.Box 57561-165UrmiaIran Faculty of Materials Engineering Sahand University of TechnologyP.O.Box 51335-1996TabrizIran

The tri-metal Ti-Al-Nb composites were processed through three procedures:hot pressing,rolling,and hot pressing,followed by subsequent *** fabricated composites were then subjected to annealing at 600,625,and 650℃ temperatures at different *** observation at the interfaces reveals that the increase in plastic deformation strain significantly affects TiAl_(3) intermetallic layers’evolution and accelerates the layers’*** the contrary,the amount of applied strain does not significantly affect the evolution of the NbAl_(3) intermetallic layer *** was also found that Al and Ti atoms’diffusion has occurred throughout the TiAl_(3) layer,but only Al atoms diffuse through the NbAl_(3) *** slow growth rate of the NbAl_(3) intermetallic layer is due to the lack of diffusion of Nb atoms and the high activation energy of Al atoms’reaction with Nb atoms.

关键词： intermetallic compounds diffusion Ti/Al/Nb composite deformation annealing

Influence of Surface Treatment on the Corrosion Resistance of Stainless Steel in Simulated Human Body Environment

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Journal of Materials Science & Technology 2009年第5期25卷 611-614页

作者： Esmaeil jafari mohammad Jafar Hadianfard Dept.of Materials Science and Engineering

In the present research, the influence of chromium enrichment by surface treatment on corrosion resistance of type 316L stainless steel in body environment was investigated. For this study, weight loss test during 18 months, cyclic and liner polarization tests before and after surface treatment and metallography by electron and light microscopy were used to evaluate the effectiveness of the proposed method. In addition, X-ray photoelectron spectroscopy （XPS） method was used to determine the chromium concentration in the surface layer after surface treatment. Results show that the surface treatment has improved corrosion resistance of the type 316L stainless steel in body environment.

关键词： Surface treatment Corrosion Passive film Polarization resistance

Numerical Study of Aeroacoustic Sound on Performance of Bladeless Fan

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Chinese Journal of Mechanical Engineering 2017年第2期30卷 483-494页

作者： mohammad jafari Atta Sojoudi Parinaz Hafezisefat Aerospace Engineering Department Iowa State UniversityAmesUSA Mechanical Engineering Department University of TehranTehranIran Mechanical Engineering Department Iowa State UniversityAmesUSA

Aeroacoustic performance of fans is essential due to their widespread application. Therefore, the original aim of this paper is to evaluate the generated noise owing to different geometric parameters. In current study, effect of five geometric parameters was investigated on well performance of a Bladeless fan. Airflow through this fan was analyzed simulating a Bladeless fan within a 2 m×2 m×4 m room. Analysis of the flow field inside the fan and evaluating its performance were obtained by solving conservations of mass and momentum equations for aerodynamic investigations and FW-H noise equations for aeroacoustic analysis. In order to design Bladeless fan Eppler 473 airfoil profile was used as the cross section of this fan. Five distinct parameters, namely height of cross section of the fan, outlet angle of the flow relative to the fan axis, thickness of airflow outlet slit, hydraulic diameter and aspect ratio for circular and quadratic cross sections were considered. Validating acoustic code results, we compared numerical solution of FW-H noise equations for NACA0012 with experimental results. FW-H model was selected to predict the noise generated by the Bladeless fan as the numerical results indicated a good agreement with experimental ones for NACA0012. To validate 3-D numerical results, the experimental results of a round jet showed good agreement with those simulation data. In order to indicate the effect of each mentioned parameter on the fan performance, SPL and OASPL diagrams were illustrated.

关键词： Bladeless fan Computational fluid dynamic (CFD) Aeroacoustic performance Ffowcs Williams and Hawkings (FW-H) formulation

One-step synthesis of Ni@Pd/NH_(2)-Fe_(3)O_(4)nanoparticles as affordable catalyst for formic acid dehydrogenation

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Chinese Journal of Chemical Engineering 2021年第4期34卷 168-174页

作者： mohammad Reza Nabid Yasamin Bide Mahsa jafari Department of Polymer&Material Chemistry Faculty of Chemistry&Petroleum ScienceShahid Beheshti UniversityTehran ***Iran

Currently,one of the critical issues in the world is finding an appropriate green alternative to fossil fuels due to the concerns about global *** a hydrogen source,formic acid has been given particular attention owing to the attractive features such as highenergy density,no toxicity,high stability at ambient temperature and high hydrogen *** an affordable and highly efficient catalyst with easy recovery from the reaction mixture for selective dehydrogenation of formic acid is still *** this report,we used a simple onestep process to synthesize Ni@Pd core shell nanoparticles on 3aminopropyltriethoxysilane modified Fe3O4 *** existence of Ni and Pd results in a synergic effect on the catalytic ***—NH2 groups play an important role for obtaining welldispersed ultrafine particles with high surface area and active *** addition,Fe3O4 lead to convenient magnetic recovery of the catalyst from reaction *** results indicate that the asprepared catalyst give the superb turnover frequency of 5367.8 h 1 with no additive,which is higher than most of the previously reported catalysts.

关键词： Core-shell Fe_(3)O_(4) Catalysis Dehydrogenation Formic acid

Application of different CFD multiphase models to investigate effects of baffles and nanoparticles on heat transfer enhancement

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Frontiers of Chemical Science and Engineering 2014年第3期8卷 320-329页

作者： ali SHAHmohammadI Arezou jafari Chemical Engineering Department Tarbiat Modares University Tehran 114-14115 Iran

In this work, the effect of baffles in a pipe on heat transfer enhancement was studied using computa- tional fluid dynamics （CFD） in the presence of Al2O3 nanoparticles which are dispersed into water. Fluid flow through the horizontal tube with uniform heat flux was simulated numerically and three dimensional governing partial differential equations were solved. To find an accurate model for CFD simulations, the results obtained by the single phase were compared with those obtained by three different multiphase models including Eulerian, mixture and volume of fluid （VOF） at Reynolds numbers in range of 600 to 3000, and two different nanoparticle concentrations （1% and 1.6%）. It was found that multi- phase models could better predict the heat transfer in nanofluids. The effect of baffles on heat transfer of nanofluid flow was also investigated through a baffled geometry. The numerical results show that at Reynolds numbers in the range of 600 to 2100, the heat transfer of nanofluid flowing in the geometry without baffle is greater than that of water flowing through a tube with baffle, whereas the difference between these effects （nanofluid and baffle） decreases with increasing the Reynolds number. At higher Reynolds numbers （2100-3000） the baffle has a greater effect on heat transfer enhancement than the nanofluid.

关键词： CFD simulation heat transfer nanofluid,baffle single phase model multiphase model

Combining the 8-hydroxyquinoline intercalated layered double hydroxide film and sol-gel coating for active corrosion protection of the magnesium alloy

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International Journal of Minerals,Metallurgy and Materials 2022年第3期29卷 536-546页

作者： Yahya jafari Tarzanagh Davod Seifzadeh Roghaye Samadianfard Applied Chemistry Department University of Mohaghegh ArdabiliArdabil ***Iran

8-hydroxyquinoline(8-HQ)intercalated layered double hydroxides(LDH)film as underlayer and sol-gel layer was combined for active corrosion protection of the AM60B magnesium *** LDH,LDH/sol-gel,and LDH@HQ/sol-gel coatings were analyzed using the scanning electron microscopy(SEM),field emission scanning electron microscopy(FESEM),energy dispersive X-ray spectroscopy(EDS),X-ray diffraction(XRD),atomic force microscopy(AFM),and electrochemical impedance spectroscopy(EIS)*** SEM images showed that the surface was entirely coated by the LDH film composed of vertically-grown *** same morphology was observed for the LDH/sol-gel and LDH@HQ/sol-gel ***,almost the same topography was observed for both composite coatings except that the LDH@HQ/sol-gel coating had relatively higher surface *** the LDH film had the same impedance behavior as the alloy sample in 3.5wt%NaCl solution,its corrosion resistance was much higher,which could be due to its barrier properties as well as to the trap-ping of the chloride *** to the LDH film,the corrosion resistance of the LDH/sol-gel composite diminished with increasing the ex-posure ***,its values were much higher than that of the LDH film,which was mainly related to the sealing of the solution *** LDH@HQ/sol-gel composite showed much better anti-corrosion properties than the LDH/sol-gel coating due to the adsorption of the 8-HQ on the damaged areas through the complexation.

关键词： magnesium alloy sol-gel layered double hydroxides corrosion coating

Molecular determination and genotyping of Cryptosporidium *** fecal and respiratory samples of industrial poultry in Iran

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Asian Pacific Journal of Tropical Medicine 2014年第7期7卷 517-520页

作者： Hossein Hamidinejat mohammad Hossein Razi Jalali Ramezan ali jafari Kiomars Nourmohammadi Department of Pathobiology Veterinary FacultyShahid Chamran University Department of Clinical Sciences Veterinary FacultyShahid Chamran University MSc Student of Parasitology Shahid Chamran University

Objective:To identify the genotypes of prevalent Cryptosporidia in broiler chickens in Lorestan province,***:A total of 1 000 fecal and 1 000 trachea samples were collected from *** from both fecal and tracheal samples were stained with modified ZiehlNeelsen method and nested PCR-RFTP according to amplification of 18S rRNA gene using Ssp1 and Vsp 1 restriction enzymes and DNA ***:From the examined chickens0.7%was positive for Cryptosporidium,Infection was present in 0.3%fecal samples and also in0.5%*** 0.3%of simultaneous infections in fecal and tracheal samples were *** PCR of our isolates demonstrated Cryptosporidium ***:In our work,low rate of Cryptosporidium baileyi infection was detected,but in critical situations and our poor management circumstances,cryptosporidiosis occurs in serious feature especially in immune suppressed individuals.

关键词： Cryptosporidium Prevalence PCR-RFLP Sequencing Chicken Iran

Excess mortality in Northeast Iran caused by COVID-19:Neglect of offset community transformations of health

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Asian Pacific Journal of Tropical Medicine 2023年第6期16卷 261-267页

作者： Nayereh Esmaeilzadeh Seyed Javad Hoseini Majid jafari Nejad-Bajestani mohammadtaghi Shakeri Zahra Izadi Mood Hamidreza Hoseinzadeh mohammad Hasan Derakhshan Dooghaee Department of Epidemiology School of HealthMashhad University of Medical SciencesMashhadIran Department of Medical Biotechnology and Nanotechnology Faculty of MedicineMashhad University of Medical SciencesMashhadIran Department of Persian Medicine School of Persian and Complementary MedicineMashhad University of Medical SciencesMashhadIran Department of Biostatistics School of HealthMashhad University of Medical SciencesMashhadIran Health Deputy Mashhad University of Medical SciencesMashhadIran

Objective:To make evidence-based decisions based on broad mortality trends for Razavi Khorasan province,***:In order to determine the baseline number of deaths,we used univariate time series analyses for monthly data from the monthly vital statistics reports(From April 2015 to March 2022).For excess mortalities,these baselines were subtracted from reported deaths with a 95%prediction *** compare time and causes,a P-score was ***:From March 2020 to March 2022,there were 61949 registered deaths,and the estimated deaths with a 95%confidence interval(CI)were 43246.16(35718.28,50774.05).So,in 2020-2021 and 2021-2022,the death counts were 35.15%and 51.33%higher than projected.A total of 18666 cardiovascular diseases were reported and a total of 15704.46(12006.95,19401.96)was *** P-score for this duration was 14.49%and 23.23%higher than *** and parasitic diseases plus COVID-19 were 16633 and estimated to be 1044.87(456.77,1632.96).A total of 4420 diseases of the respiratory system were reported,and 4564.94 deaths were predicted(2277.43,6852.43).In the first year of the pandemic,the P-score dropped to-35.28%and in the second year,it jumped sharply to 22.38%.Conclusions:Excess mortality,along with cause-specific mortality,can be helpful for monitoring trends and developing public health policies at the local,national,and international levels.

关键词： Mortality COVID-19 Health Systems Plans Prediction Cardiovascular deaths

Improving the Sound Absorption Properties of Flexible Polyurethane (PU) Foam using Nanofibers and Nanoparticles

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Sound & Vibration 2019年第5期53卷 207-222页

作者： Roohalah Hajizadeh ali Khavanin mohammad Barmar Ahmad Jonidi jafari Somayeh Farhang Dehghan Department of Occupational Health Engineering Faculty of Medical SciencesTarbiat Modares UniversityTehranIran Department of Polyurethane Iran Polymer and Petrochemical InstituteTehranIran Research Center for Environmental Health Technology Department of Environmental Health EngineeringIran University of Medical SciencesTehranIran Department of Occupational Health and Safety at Work Workplace Health Promotion Research CenterSchool of Public Health and SafetyShahid Beheshti University of Medical SciencesTehranIran

Polyurethane foam as the most well-known absorbent materials has a suitable absorption coefficient only within a limited frequency *** aim of this study was to improve the sound absorption coefficient of flexible polyurethane(PU)foam within the range of various frequencies using clay nanoparticles,polyacrylonitrile nanofibers,and polyvinylidene fluoride *** response surface method was used to determine the effect of addition of nanofibers of PAN and PVDF,addition of clay nanoparticles,absorbent thickness,and air gap on the sound absorption coefficient of flexible polyurethane foam(PU)across different frequency *** absorption coefficient of the samples was measured using Impedance Tubes *** clay at low thicknesses as well as polyacrylonitrile nanofibers and polyvinyl fluoride nanofibers at higher thicknesses had a greater positive effect on absorption *** mean sound absorption coefficient in the composite with the highest absorption coefficient at middle and high frequencies was 0.798 and 0.75,*** comparison with pure polyurethane foam with the same thickness and air gap,these values were 2.22 times at the middle frequencies and 1.47 times at high frequencies,*** porosity rose with increasing nano clay,but decreased with increasing polyacrylonitrile nanofibers and polyvinyl fluoride *** results indicated that the absorption coefficient was elevated with increasing the thickness and air *** study suggests that the use of a combination of nanoparticles and nanofibers can enhance the acoustic properties of flexible polyurethane foam.

关键词： Sound absorption coefficient flexible polyurethane foam nano clay polyacrylonitrile nanofibers polyvinyl fluoride nanofibers