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Evaluation of antioxidant enzymes activities and identification of intermediate products during phytoremediation of an anionic dye(C.I. Acid Blue 92) by pennywort(Hydrocotyle vulgaris)

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Journal of Environmental Sciences 2013年第11期25卷 2214-2222页

作者： Fatemeh vafaei Ali Movafeghi Alireza Khataee Department of Plant Biology Faculty of Natural Sciences University of Tabriz Research Laboratory of Advanced Water and Wastewater Treatment Processes Department of Applied ChemistryFaculty of Chemistry University of Tabriz

The potential of pennywort （Hydrocotyle vulgaris） for phytoremediation of C.I. Acid Blue 92 （AB92） was evaluated. The effects of various experimental parameters including pH, temperature, dye concentration and plant weight on dye removal efficiency were investigated. The results showed that the optimal condition for dye removal were pH 3.5 and temperature 25~C. Moreover, the absolute dye removal enhanced with increase in the initial dye concentration and plant weight. Pennywort showed the same removal efficiency in repeated experiments （four runs） as that obtained from the first run （a 6-day period）. Therefore, the ability of the plant in consecutive removal of AB92 confirmed the biodegradation process. Accordingly, a number of produced intermediate compounds were identified. The effect of treatment on photosynthesis and antioxidant defense system including superoxide dismutase, peroxidase and catalase in plant roots and leaves were evaluated. The results revealed a reduction in photosynthetic pigments content under dye treatments. Antioxidant enzyme responses showed marked variations with respect to the plant organ and dye concentration in the liquid medium. Overall, the increase in antioxidant enzyme activity under AB92 stress in the roots was much higher than that in the leaves. Nevertheless, no significant increase in malondialdehyde content was detected in roots or leaves, implying that the high efficiency of antioxidant system in the elimination of reactive oxygen species. Based on these results, pennywort was founded to be a capable species for phytoremediation of AB92-contaminated water, may be effective for phytoremediation dye-contaminated polluted aquatic ecosystems.

关键词： phytoremediation anionic dye Hydrocotyle vulgaris antioxidant enzymes photosynthetic pigments

Review of nanofluids for heat transfer applications

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Particuology 2009年第2期7卷 141-150页

作者： Dongsheng Wen Guiping Lin Saeid vafaei Kai Zhang School of Engineering and Materials Science Queen Mary University of London E1 4NS United Kingdom School of Aeronautics Engineering Beijing University of Aeronautic and Astronautics Beijing China State Key Lab of Heavy Oil Processing China University of Petroleum Beijing 102249 China

Research on nanofluids has progressed rapidly since its enhanced thermal conductivity was first reported about a decade ago, though much controversy and inconsistency have been reported, and insufficient understanding of the formulation and mechanism of nanofluids further limits their applications. This work presents a critical review of research on heat transfer applications of nanofluids with the aim of identifying the limiting factors so as to push forward their further development.

关键词： Nanofluids Nanoparticles Process intensification Thermal conductivities Boiling Convective heat transfer

Enhancement of grid-connected photovoltaic system using ANFIS-GA under different circumstances

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Frontiers in Energy 2015年第3期9卷 322-334页

作者： Saeed vafaei Alireza REZVANI Majid GANDOMKAR Maziar IZADBAKHSH Department of Electrical Engineering Saveh Branch Islamic Azad University Saveh Iran

In recent years, many different techniques are applied in order to draw maximum power from photo- voltaic （PV） modules for changing solar irradiance and temperature conditions. Generally, the output power generation of the PV system depends on the intermittent solar insolation, cell temperature, efficiency of the PV panel and its output voltage level. Consequently, it is essential to track the generated power of the PV system and utilize the collected solar energy optimally. The aim of this paper is to simulate and control a grid-connected PV source by using an adaptive neuro-fuzzy inference system （ANFIS） and genetic algorithm （GA） controller. The data are optimized by GA and then, these optimum values are used in network training. The simulation results indicate that the ANFIS-GA controller can meet the need of load easily with less fluctuation around the maximum power point （MPP） and can increase the convergence speed to achieve the MPP rather than the conventional method. Moreover, to control both line voltage and current, a grid side P/Q controller has been applied. A dynamic modeling, control and simulation study of the PV system is performed with the Matlab/Simulink program.

关键词： photovoltaic system maximum power point(MPP) adaptive neuro-fuzzy inference system (ANFIS),genetic algorithm (GA)

Aging behavior of a copper-bearing high-strength low-carbon steel

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International Journal of Minerals,Metallurgy and Materials 2018年第4期25卷 429-438页

作者： Babak Shahriari Reza vafaei Ehsan Mohammad Sharifi Khosro Farmanesh Department of Materials Engineering Malek Ashtar University of Technology

The effects of aging temperature and time on the hardness and impact toughness of a copper-bearing high-strength low-carbon steel were investigated. The hardness of the aged samples reached maxima after 1 h and 5 h of aging at 500 and 450℃, respectively; this increase in hardness was followed by a decrease in hardness until a temperature of 700℃, at which secondary hardening was observed. The impact toughness of the aged steel was found to be higher for 5 h of aging. Transmission electron microscopy confirmed the presence of carbide and copper precipitates; also, the secondary hardening could be the result of the transformation of austenite（formed in the aging treatment） to martensite. Differential scanning calorimetry of the steel was performed to better understand the precipitation behavior. The results revealed that the precipitation of the steel exhibited two significant stages of copper precipitate nucleation and coarsening of the precipitates, with corresponding activation energies of 49 and 238 kJ·mol^-1, respectively.

关键词： aging treatment BA-160 steel differential scanning calorimetry precipitation

Hot compression deformation behavior of AISI 321 austenitic stainless steel

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International Journal of Minerals,Metallurgy and Materials 2013年第6期20卷 529-534页

作者： Mehdi Haj Hojjatollah Mansouri Reza vafaei Golam Reza Ebrahimi Ali Kanani Department of Materials Engineering Malek Ashtar University of Technology Department of Materials and Polymer Engineering Faculty of Engineering Hakim Sabzevari University

The hot compression behavior of AISI 321 ll00~C and the strain rates of 0.01-1 s-1 using a Baehr austenitic stainless steel was studied at the temperatures of 950- DIL-805 deformation dilatometer. The hot deformation equations and the relationship between hot deformation parameters were obtained. It is found that strain rate and deformation temperature significantly influence the flow stress behavior of the steel. The work hardening rate and the peak value of flow stress increase with the decrease of deformation temperature and the increase of strain rate. In addition, the activation energy of deformation （Q） is calculated as 433.343 kJ/mol. The microstructural evolution during deformation indicates that, at the temperature of 950~C and the strain rate of 0.01 s-1, small circle-like precipitates form along grain boundaries; but at the temperatures above 950~C, the dissolution of such precipitates occurs. Energy-dispersive X-ray analyses indicate that the precipitates are complex carbides of Cr, Fe, Mn, Ni, and Ti.

关键词： austenitic stainless steel deformation constitutive equations microstructural evolution activation energy

Effects of TiO_2 nanoparticles on the aquatic plant Spirodela polyrrhiza: Evaluation of growth parameters, pigment contents and antioxidant enzyme activities

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Journal of Environmental Sciences 2018年第2期30卷 130-138页

作者： Ali Movafeghi Alireza Khataee Mahboubeh Abedi Roshanak Tarrahi Mohammadreza Dadpour Fatemeh vafaei Department of Plant Biology Faculty of Natural Sciences University of Tabriz Research Laboratory of Advanced Water and Wastewater Treatment Processes Department of Applied Chemistry Faculty of ChemistryUniversity of Tabriz Department of Materials Science and Nanotechnology Near East University Department of Horticultural Science Faculty of Agriculture University of Tabriz

Plants are essential components of all ecosystems and play a critical role in environmental fate of nanoparticles. However, the toxicological impacts of nanoparticles on plants are not well documented. Titanium dioxide nanoparticles（TiO2-NPs） are produced worldwide in large quantities for a wide range of purposes. In the present study, the uptake of TiO2-NPs by the aquatic plant Spirodela polyrrhiza and the consequent effects on the plant were ***, structural and morphological characteristics of the used TiO2-NPs were determined using XRD, SEM, TEM and BET techniques. As a result, an anatase structure with the average crystalline size of 8 nm was confirmed for the synthesized TiO2-NPs. Subsequently, entrance of TiO2-NPSto plant roots was verified by fluorescence microscopic images. Activity of a number of antioxidant enzymes, as well as, changes in growth parameters and photosynthetic pigment contents as physiological indices were assessed to investigate the effects of TiO2-NPs on S. polyrrhiza. The increasing concentration of TiO2-NPs led to the significant decrease in all of the growth parameters and changes in antioxidant enzyme activities. The activity of superoxide dismutase enhanced significantly by the increasing concentration of TiO2-NPs. Enhancement of superoxide dismutase activity could be explained as promoting antioxidant system to scavenging the reactive oxygen species. In contrast, the activity of peroxidase was notably decreased in the treated plants. Reduced peroxidase activity could be attributed to either direct effect of these particles on the molecular structure of the enzyme or plant defense system damage due to reactive oxygen species.

关键词： TiO2 nanoparticles Spirodela polyrrhiza Growth parameters Antioxidant enzymes Pigment contents

Seismic Health Monitoring of Foundations Using Artificial Neural Networks

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Journal of Civil Engineering and Architecture 2012年第6期6卷 730-737页

作者： Azlan bin Adnan Mohammadreza vafaei Faculty of Civil Engineering Universiti Teknologi Malaysia Johor 81310 Malaysia

Damage identification plays an important role in structural health monitoring systems. Despite variety in damage identification methods, little attention has been paid to the seismic damage identification of foundations. When shear walls serve as the lateral load resistance system of structures, foundations may subject to the high level of concentrated moment and shear forces. Consequently, they can experience severe damage. Since such damage is often internal and not visible, visual inspections cannot identify the location and the severity of damage. Therefore, a robust method is required for damage localization and quantification of foundations. According to the concept of performance-based seismic design of structures, the seismic behavior of foundations is considered as Force-Controlled. Therefore, for damage identification of foundation, internal forces should be estimated during ground motions. In this study, for real-time seismic damage detection of foundations, a method based on artificial neural networks was proposed. A feed-forward multilayer neural network with one hidden layer was selected to map input samples to output parameters. The lateral displacements of stories were considered as the input parameters of the neural network while moment and shear force demands at critical points of foundations were taken into account as the output parameters. In order to prepare well-distributed data sets for training the neural network, several nonlinear time history analyses were carried out. The proposed method was tested on the foundation of a five-story concrete shear wall building. The obtained results revealed that the proposed method was successfully estimated moment and shear force demands at the critical points of the foundation.

关键词： Structural health monitoring seismic damage detection artificial neural networks performance-based design.

The Influence of Tetranychus urticae Koch (Acari: Tetranychidae) Life Table and Reproductive Parameters by Applying Si on Bean at Library Condition

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Advances in Entomology 2016年第5期4卷 260-267页

作者： Elahe Sadeghi Reza vafaei Shoushtari Hamid Madani Entomology Student Department Arak Branch Islamic Azad University Arak Iran Faculty of Entomology Arak Branch Islamic Azad University Arak Iran Faculty of Agriculture Arak Branch Islamic Azad University Arak Iran

Two-spotted spider mite, Tetranychus urticae Koch, is one of the important pests of bean, which can cause severe damages on it. Silicon is one of the micronutrient elements, as its spray on the leaves can decrease the population of the pest. In this research, the impact of four different doses of Si (0, 1, 1/5, 2 ppm) was investigated on biological and population growth parameters of T. urticae. The experiments were carried out in Petri dishes in an incubator at 25°C ± 2°C, 65% ± 5% RH and 16 L: 8 D. The duration of developmental stage was significantly affected by Si dose. The longest immature period, the shortest longevity of females and the shortest oviposition period were obtained at 2 ppm. In addition, Si dose significantly affected population growth parameters of the mite. The intrinsic rate of natural increase (rm) of the mite ranged from 0.246 to 0.215 day which lowest and the highest values were at 2 ppm and control plants, respectively. The lowest net reproductive rate (R0) and finite rate of increase (λ) of the mite and the highest value of mean generation time (T) and doubling time (DT) were estimated at 2 ppm. The results of this peruse represented that 2 ppm had better potential for decreasing the population of the two-spotted spider mite, and it can be used in the mite integrated pest management programs.

关键词： Two-Spotted Spider Mite Si Biological Parameters Intrinsic Rate of Natural Increase

The Aquatic Beetles Families:Hydraenidae and Hydrophilidae in County Khoramabad

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Journal of Environmental Science and Engineering(A) 2020年第1期9卷 13-16页

作者： Elliye Yahyapour Razie Mahdavi Reza vafaei-Shoushtari Department of Entomology Faculty of Agricultural SciencesIslamic Azad UniversityArak-BranchArak 38135/567Iran

This investigation was carried out during 2016-2017 in order to identify the aquatic beetle species of county Khoramabad in west of *** genera and seven species belonging to families Hydrophilidae and Hydraenidae were *** species,Berosus luridus(Linnaeus,1761),Limnebius nitidus(Marsham,1802)and Ochthebius nilssoni(Hebauer,1986)are recorded for the first time from Iran.

关键词： Aquatic Hydraenidae Hydrophilidae Khoramabad